Search results for: selective inhibition
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 1781

Search results for: selective inhibition

251 The Effect of SIAH1 on PINK1 Homeostasis in Parkinson Disease

Authors: Fatimah Abd Elghani, Raymonde Szargel, Vered Shani, Hazem Safory, Haya Hamza, Mor Savyon, Ruth Rott, Rina Bandopadhyay, Simone Engelender

Abstract:

Background: PINK1 is a mitochondrial kinase mutated in some familial cases of Parkinson’s disease. Down regulation of PINK1 results in abnormal mitochondrial morphology and altered membrane potential. Although PINK1 has a predicted mitochondrial import sequence, it’s cellular, and submitochondrial localization remains unclear, in part because it is rapidly degraded. In this work, we investigated the mechanisms involved in PINK1 degradation and how this may affect PINK1 stability and function, with implications for mitochondrial function in PD. In addition, pharmacological inhibition of proteasome activity was shown to lead to PINK1 accumulation, indicating that PINK1 degradation depends on the ubiquitin-proteasome system (UPS). Methods: Using co-immunoprecipitation assays, we identified E3 ubiquitin ligase SIAH1 as a PINK1-interacting protein in HEK293 cells as well as on rat brain tissues. In addition, we determined the effect of SIAH 1, SIAH2 and Parkin on PINK1 steady-state levels by Western blot analysis, and checked their possibility to ubiquitinate and mediate PINK1 degradation through the proteasome carried out in vivo ubiquitination experiments. Results: We have obtained results showing that SIAH-1 interacts with and ubiquitinates PINK1. The ubiquitination promoted by SIAH-1 leads to the proteasomal degradation of PINK1. We confirmed these findings by knocking down SIAH-1 and observing important accumulation of PINK1 in cells. Besides, we found that SIAH-1 decreases PINK1 steady-state levels but not the E3 ligase Parkin. We also investigated the interaction of SIAH-1 with PINK1 disease mutants and its ability to promote their ubiquitination and degradation. Although, no clear difference in the ability of SIAH-1 to promote the degradation of PINK1 disease mutants was observed. It is possible that dysfunction of proteasomal activity in the disease may lead to the accumulation and aggregation of ubiquitinated PINK1 in patients with PINK1 mutations, with possible implications to the pathogenesis of PD. Conclusions: Here, we demonstrated that SIAH-1 ubiquitinates and promotes the degradation of PINK1. In addition, SIAH-1 represents now a target that may help the improvement of mitophagy in PD. Further investigations needed to understand how mitophagy is regulated by PINK1-SIAH-1 axis to provide targets for future therapeutics.

Keywords: PD, Parkinson's disease, PINK1, PTEN-induced kinase1, SIAH, seven in absentia homolog, SN, substantia nigra

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250 Correlation Between the Toxicity Grade of the Adverse Effects in the Course of the Immunotherapy of Lung Cancer and Efficiency of the Treatment in Anti-PD-L1 and Anti-PD-1 Drugs - Own Clinical Experience

Authors: Anna Rudzińska, Katarzyna Szklener, Pola Juchaniuk, Anna Rodzajweska, Katarzyna Machulska-Ciuraj, Monika Rychlik- Grabowska, Michał łOziński, Agnieszka Kolak-Bruks, SłAwomir Mańdziuk

Abstract:

Introduction: Immune checkpoint inhibition (ICI) belongs to the modern forms of anti-cancer treatment. Due to the constant development and continuous research in the field of ICI, many aspects of the treatment are yet to be discovered. One of the less researched aspects of ICI treatment is the influence of the adverse effects on the treatment success rate. It is suspected that adverse events in the course of the ICI treatment indicate a better response rate and correlate with longer progression-free- survival. Methodology: The research was conducted with the usage of the documentation of the Department of Clinical Oncology and Chemotherapy. Data of the patients with a lung cancer diagnosis who were treated between 2019-2022 and received ICI treatment were analyzed. Results: Out of over 133 patients whose data was analyzed, the vast majority were diagnosed with non-small cell lung cancer. The majority of the patients did not experience adverse effects. Most adverse effects reported were classified as grade 1 or grade 2 according to CTCAE classification. Most adverse effects involved skin, thyroid and liver toxicity. Statistical significance was found for the adverse effect incidence and overall survival (OS) and progression-free survival (PFS) (p=0,0263) and for the time of toxicity onset and OS and PFS (p<0,001). The number of toxicity sites was statistically significant for prolonged PFS (p=0.0315). The highest OS was noted in the group presenting grade 1 and grade 2 adverse effects. Conclusions: Obtained results confirm the existence of the prolonged OS and PFS in the adverse-effects-charged patients, mostly in the group presenting mild to intermediate (Grade 1 and Grade 2) adverse effects and late toxicity onset. Simultaneously our results suggest a correlation between treatment response rate and the toxicity grade of the adverse effects and the time of the toxicity onset. Similar results were obtained in several similar research conducted - with the proven tendency of better survival in mild and moderate toxicity; meanwhile, other studies in the area suggested an advantage in patients with any toxicity regardless of the grade. The contradictory results strongly suggest the need for further research on this topic, with a focus on additional factors influencing the course of the treatment.

Keywords: adverse effects, immunotherapy, lung cancer, PD-1/PD-L1 inhibitors

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249 Stems of Prunus avium: An Unexplored By-product with Great Bioactive Potential

Authors: Luís R. Silva, Fábio Jesus, Catarina Bento, Ana C. Gonçalves

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Over the last few years, the traditional medicine has gained ground at nutritional and pharmacological level. The natural products and their derivatives have great importance in several drugs used in modern therapeutics. Plant-based systems continue to play an essential role in primary healthcare. Additionally, the utilization of their plant parts, such as leaves, stems and flowers as nutraceutical and pharmaceutical products, can add a high value in the natural products market, not just by the nutritional value due to the significant levels of phytochemicals, but also by to the high benefit for the producers and manufacturers business. Stems of Prunus avium L. are a byproduct resulting from the processing of cherry, and have been consumed over the years as infusions and decoctions due to its bioactive properties, being used as sedative, diuretic and draining, to relief of renal stones, edema and hypertension. In this work, we prepared a hydroethanolic and infusion extracts from stems of P. avium collected in Fundão Region (Portugal), and evaluate the phenolic profile by LC/DAD, antioxidant capacity, α-glucosidase inhibitory activity and protection of human erythrocytes against oxidative damage. The LC-DAD analysis allowed to the identification of 19 phenolic compounds, catechin and 3-O-caffolquinic acid were the main ones. In a general way, hydroethanolic extract proved to be more active than infusion. This extract had the best antioxidant activity against DPPH• (IC50=22.37 ± 0.28 µg/mL) and superoxide radical (IC50=13.93 ± 0.30 µg/mL). Furthermore, it was the most active concerning inhibition of hemoglobin oxidation (IC50=13.73 ± 0.67 µg/mL), hemolysis (IC50=1.49 ± 0.18 µg/mL) and lipid peroxidation (IC50=26.20 ± 0.38 µg/mL) on human erythrocytes. On the other hand, infusion revealed to be more efficient towards α-glucosidase inhibitory activity (IC50=3.18 ± 0.23 µg/mL) and against nitric oxide radical (IC50=99.99 ± 1.89 µg/mL). The Sweet cherry sector is very important in Fundão Region (Portugal), and taking profit from the great wastes produced during processing of the cherry to produce added-value products, such as food supplements cannot be ignored. Our results demonstrate that P. avium stems possesses remarkable antioxidant and free radical scavenging properties. It is therefore, suggest, that P. avium stems can be used as a natural antioxidant with high potential to prevent or slow the progress of human diseases mediated by oxidative stress.

Keywords: stems, Prunus avium, phenolic compounds, biological potential

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248 Analysis of Metamaterial Permeability on the Performance of Loosely Coupled Coils

Authors: Icaro V. Soares, Guilherme L. F. Brandao, Ursula D. C. Resende, Glaucio L. Siqueira

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Electrical energy can be wirelessly transmitted through resonant coupled coils that operate in the near-field region. Once in this region, the field has evanescent character, the efficiency of Resonant Wireless Power Transfer (RWPT) systems decreases proportionally with the inverse cube of distance between the transmitter and receiver coils. The commercially available RWPT systems are restricted to short and mid-range applications in which the distance between coils is lesser or equal to the coil size. An alternative to overcome this limitation is applying metamaterial structures to enhance the coupling between coils, thus reducing the field decay along the distance between them. Metamaterials can be conceived as composite materials with periodic or non-periodic structure whose unconventional electromagnetic behaviour is due to its unit cell disposition and chemical composition. This new kind of material has been used in frequency selective surfaces, invisibility cloaks, leaky-wave antennas, among other applications. However, for RWPT it is mainly applied as superlenses which are lenses that can overcome the optical limitation and are made of left-handed media, that is, a medium with negative magnetic permeability and electric permittivity. As RWPT systems usually operate at wavelengths of hundreds of meters, the metamaterial unit cell size is much smaller than the wavelength. In this case, electric and magnetic field are decoupled, therefore the double negative condition for superlenses are not required and the negative magnetic permeability is enough to produce an artificial magnetic medium. In this work, the influence of the magnetic permeability of a metamaterial slab inserted between two loosely coupled coils is studied in order to find the condition that leads to the maximum transmission efficiency. The metamaterial used is formed by a subwavelength unit cell that consist of a capacitor-loaded split ring with an inner spiral that is designed and optimized using the software Computer Simulation Technology. The unit cell permeability is experimentally characterized by the ratio of the transmission parameters between coils measured with and without the presence of the metamaterial slab. Early measurements results show that the transmission coefficient at the resonant frequency after the inclusion of the metamaterial is about three times higher than with just the two coils, which confirms the enhancement that this structure brings to RWPT systems.

Keywords: electromagnetic lens, loosely coupled coils, magnetic permeability, metamaterials, resonant wireless power transfer, subwavelength unit cells

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247 Identification, Synthesis, and Biological Evaluation of the Major Human Metabolite of NLRP3 Inflammasome Inhibitor MCC950

Authors: Manohar Salla, Mark S. Butler, Ruby Pelingon, Geraldine Kaeslin, Daniel E. Croker, Janet C. Reid, Jong Min Baek, Paul V. Bernhardt, Elizabeth M. J. Gillam, Matthew A. Cooper, Avril A. B. Robertson

Abstract:

MCC950 is a potent and selective inhibitor of the NOD-like receptor pyrin domain-containing protein 3 (NLRP3) inflammasome that shows early promise for treatment of inflammatory diseases. The identification of major metabolites of lead molecule is an important step during drug development process. It provides an information about the metabolically labile sites in the molecule and thereby helping medicinal chemists to design metabolically stable molecules. To identify major metabolites of MCC950, the compound was incubated with human liver microsomes and subsequent analysis by (+)- and (−)-QTOF-ESI-MS/MS revealed a major metabolite formed due to hydroxylation on 1,2,3,5,6,7-hexahydro-s-indacene moiety of MCC950. This major metabolite can lose two water molecules and three possible regioisomers were synthesized. Co-elution of major metabolite with each of the synthesized compounds using HPLC-ESI-SRM-MS/MS revealed the structure of the metabolite (±) N-((1-hydroxy-1,2,3,5,6,7-hexahydro-s-indacen-4-yl)carbamoyl)-4-(2-hydroxypropan-2-yl)furan-2-sulfonamide. Subsequent synthesis of individual enantiomers and coelution in HPLC-ESI-SRM-MS/MS using a chiral column revealed the metabolite was R-(+)- N-((1-hydroxy-1,2,3,5,6,7-hexahydro-s-indacen-4-yl)carbamoyl)-4-(2-hydroxypropan-2-yl)furan-2-sulfonamide. To study the possible cytochrome P450 enzyme(s) responsible for the formation of major metabolite, MCC950 was incubated with a panel of cytochrome P450 enzymes. The result indicated that CYP1A2, CYP2A6, CYP2B6, CYP2C9, CYP2C18, CYP2C19, CYP2J2 and CYP3A4 are most likely responsible for the formation of the major metabolite. The biological activity of the major metabolite and the other synthesized regioisomers was also investigated by screening for for NLRP3 inflammasome inhibitory activity and cytotoxicity. The major metabolite had 170-fold less inhibitory activity (IC50-1238 nM) than MCC950 (IC50-7.5 nM). Interestingly, one regioisomer had shown nanomolar inhibitory activity (IC50-232 nM). However, no evidence of cytotoxicity was observed with any of these synthesized compounds when tested in human embryonic kidney 293 cells (HEK293) and human liver hepatocellular carcinoma G2 cells (HepG2). These key findings give an insight into the SAR of the hexahydroindacene moiety of MCC950 and reveal a metabolic soft spot which could be blocked by chemical modification.

Keywords: Cytochrome P450, inflammasome, MCC950, metabolite, microsome, NLRP3

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246 Axillary Evaluation with Targeted Axillary Dissection Using Ultrasound-Visible Clips after Neoadjuvant Chemotherapy for Patients with Node-Positive Breast Cancer

Authors: Naomi Sakamoto, Eisuke Fukuma, Mika Nashimoto, Yoshitomo Koshida

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Background: Selective localization of the metastatic lymph node with clip and removal of clipped nodes with sentinel lymph node (SLN), known as targeted axillary dissection (TAD), reduced false-negative rates (FNR) of SLN biopsy (SLNB) after neoadjuvant chemotherapy (NAC). For the patients who achieved nodal pathologic complete response (pCR), accurate staging of axilla by TAD lead to omit axillary lymph node dissection (ALND), decreasing postoperative arm morbidity without a negative effect on overall survival. This study aimed to investigate the ultrasound (US) identification rate and success removal rate of two kinds of ultrasound-visible clips placed in metastatic lymph nodes during TAD procedure. Methods: This prospective study was conducted using patients with clinically T1-3, N1, 2, M0 breast cancer undergoing NAC followed by surgery. A US-visible clip was placed in the suspicious lymph node under US guidance before neoadjuvant chemotherapy. Before surgery, US examination was performed to evaluate the detection rate of clipped node. During the surgery, the clipped node was removed using several localization techniques, including hook-wire localization, dye-injection, or fluorescence technique, followed by a dual-technique SLNB and resection of palpable nodes if present. For the fluorescence technique, after injection of 0.1-0.2 mL of indocyanine green dye (ICG) into the clipped node, ICG fluorescent imaging was performed using the Photodynamic Eye infrared camera (Hamamatsu Photonics k. k., Shizuoka, Japan). For the dye injection method, 0.1-0.2 mL of pyoktanin blue dye was injected into the clipped node. Results: A total of 29 patients were enrolled. Hydromark™ breast biopsy site markers (Hydromark, T3 shape; Devicor Medical Japan, Tokyo, Japan) was used in 15patients, whereas a UltraCor™ Twirl™ breast marker (Twirl; C.R. Bard, Inc, NJ, USA) was placed in 14 patients. US identified the clipped node marked with the UltraCore Twirl in 100% (14/14) and with the Hydromark in 93.3% (14/15, p = ns). Success removal of clipped node marked with the UltraCore Twirl was achieved in 100% (14/14), whereas the node marked with the Hydromark was removed in 80% (12/15) (p = ns). Conclusions: The ultrasound identification rate differed between the two types of ultrasound-visible clips, which also affected the success removal rate of clipped nodes. Labelling the positive node with a US-highly-visible clip allowed successful TAD.

Keywords: breast cancer, neoadjuvant chemotherapy, targeted axillary dissection, breast tissue marker, clip

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245 Identification and Antibiotic Susceptibility of Bacteria Isolated from the Intestines of Slaughtered Goat and Cattle

Authors: Latifat Afolake Ogunfolabo, Hakeem Babafemi Ogunfolabo

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The gastrointestinal tract is densely populated with micro-organism which closely and intensively interacts with the host and ingested feed. Food borne infections are some of the major international challenges that lead to high mortality and also, antimicrobial resistance, which has been classified as a serious threat by World Health Organization. Samples of slaughtered cattle and goats intestines were collected and standard culture methods were used for bacteria isolation and identification. Minimum inhibitory concentration of commonly used antibiotic using modification of the disk diffusion method was carried out on isolates. The samples cultured were all positive to Pseudomonas aeruginosa (95% and 90%), Escherichia coli (85%), Salmonella typhi (70% and 60%), Staphylococcus aureus (75%and 100%), Micrococcus luteus (55% and35%), Bacillus macerans (60% and 5%), Bacillus cereus (25% and 20%), Clostridium perfringens (20% and 5%), Micrococcus varians (20% and 5%), Bacillus subtilis (25% and 5%), Streptococcus faecalis (40% and 25%) and Streptococcus faecium (15% and 10%) in goat and cattle respectively. Also, Proteus mirabilis (40%), Micrococcus luteus (35%), Proteus vulgaris (30%), Klebsiella aerogenes(15%) were isolated from cattle. The total coliform (13.55 x10⁵cfu/gm ± 1.77) and (20.30 x10⁵cfu/gm ± 1.27) counts were significantly higher than the total bacteria count (8.3 x10⁵cfu/gm ± 1.41) and (16.60 x10⁵cfu/gm ±0.49) for goat and cattle respectively. Selected Bacteria count of isolates showed that Staphylococcus aureus had the highest significant value (6.9 x10⁵cfu/gm ± 0.57) and (16.80 x10⁵cfu/gm ± 0.57) Escherichia coli (4.60 x10⁵cfu/gm ± 0.42) and (7.05 x10⁵cfu/gm ± 0.64) while the lowest significant value was obtained in Salmonella/Shigella (1.7 x10⁵cfu/gm ± 0.00) and (1.5 x10⁵cfu/gm ± 0.00) for goat and cattle respectively. Susceptibility of bacteria isolated from slaughtered goat and cattle intestine to commonly used antibiotics showed that the highest statistical significant value for zone of inhibition for goat was obtained for Ciprofloxacin (30.00 ± 2.25, 23.75 ± 2.49, 17.17 ± 1.40) followed by Augmentin (28.33 ± 1.22, 21. 83 ± 2.44, 16.67 ± 1.49), Erythromycin (27.75 ±1.48, 20.25 ± 1.29, 16.67 ± 1.26) while the lowest values were obtained for Ofloxacin (27.17 ± 1.89, 21.42 ± 2.19, 16.83 ± 1.26) respectively and values obtained for cattle are Ciprofloxacin (30.64 ± 1.6, 25.79 ± 1.76, 8.07 ± 11.49) followed by Augmentin (28.29 ± 1.33, 22.64 ± 1.82, 17.43 ± 1.55) Ofloxacin (26.57 ± 2.02, 20.79 ± 2.75, 16.21 ± 1.19) while the lowest values were obtained for Erythromycin (26.64 ± 1.49, 20.29 ± 1.49, 16.29 ± 1.33) at different dilution factor (10⁻¹, 10⁻², 10⁻³) respectively. The isolates from goat and cattle were all susceptible to Augmentin at the three different dilution factors. Some goat isolates are intermediate to Ciprofloxacin and Erythromycin at 10⁻² and 10⁻³, while resistance to Ciprofloxacin at 10⁻³ dilution factor. Ciprofloxacin and Ofloxacin at the dilution factors of 10⁻³ and 10⁻¹ for some cattle isolate and resistance were observed for Ofloxacin and Erythromycin at dilution of 10⁻³. These results indicate the susceptibilities and the antimicrobial resistance to commonly used antibiotic.

Keywords: antibiotic susceptibility, bacteria, cattle, goat, identification

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244 Investigating Student Behavior in Adopting Online Formative Assessment Feedback

Authors: Peter Clutterbuck, Terry Rowlands, Owen Seamons

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In this paper we describe one critical research program within a complex, ongoing multi-year project (2010 to 2014 inclusive) with the overall goal to improve the learning outcomes for first year undergraduate commerce/business students within an Information Systems (IS) subject with very large enrolment. The single research program described in this paper is the analysis of student attitudes and decision making in relation to the availability of formative assessment feedback via Web-based real time conferencing and document exchange software (Adobe Connect). The formative assessment feedback between teaching staff and students is in respect of an authentic problem-based, team-completed assignment. The analysis of student attitudes and decision making is investigated via both qualitative (firstly) and quantitative (secondly) application of the Theory of Planned Behavior (TPB) with a two statistically-significant and separate trial samples of the enrolled students. The initial qualitative TPB investigation revealed that perceived self-efficacy, improved time-management, and lecturer-student relationship building were the major factors in shaping an overall favorable student attitude to online feedback, whilst some students expressed valid concerns with perceived control limitations identified within the online feedback protocols. The subsequent quantitative TPB investigation then confirmed that attitude towards usage, subjective norms surrounding usage, and perceived behavioral control of usage were all significant in shaping student intention to use the online feedback protocol, with these three variables explaining 63 percent of the variance in the behavioral intention to use the online feedback protocol. The identification in this research of perceived behavioral control as a significant determinant in student usage of a specific technology component within a virtual learning environment (VLE) suggests that VLEs could now be viewed not as a single, atomic entity, but as a spectrum of technology offerings ranging from the mature and simple (e.g., email, Web downloads) to the cutting-edge and challenging (e.g., Web conferencing and real-time document exchange). That is, that all VLEs should not be considered the same. The results of this research suggest that tertiary students have the technological sophistication to assess a VLE in this more selective manner.

Keywords: formative assessment feedback, virtual learning environment, theory of planned behavior, perceived behavioral control

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243 AS-Geo: Arbitrary-Sized Image Geolocalization with Learnable Geometric Enhancement Resizer

Authors: Huayuan Lu, Chunfang Yang, Ma Zhu, Baojun Qi, Yaqiong Qiao, Jiangqian Xu

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Image geolocalization has great application prospects in fields such as autonomous driving and virtual/augmented reality. In practical application scenarios, the size of the image to be located is not fixed; it is impractical to train different networks for all possible sizes. When its size does not match the size of the input of the descriptor extraction model, existing image geolocalization methods usually directly scale or crop the image in some common ways. This will result in the loss of some information important to the geolocalization task, thus affecting the performance of the image geolocalization method. For example, excessive down-sampling can lead to blurred building contour, and inappropriate cropping can lead to the loss of key semantic elements, resulting in incorrect geolocation results. To address this problem, this paper designs a learnable image resizer and proposes an arbitrary-sized image geolocation method. (1) The designed learnable image resizer employs the self-attention mechanism to enhance the geometric features of the resized image. Firstly, it applies bilinear interpolation to the input image and its feature maps to obtain the initial resized image and the resized feature maps. Then, SKNet (selective kernel net) is used to approximate the best receptive field, thus keeping the geometric shapes as the original image. And SENet (squeeze and extraction net) is used to automatically select the feature maps with strong contour information, enhancing the geometric features. Finally, the enhanced geometric features are fused with the initial resized image, to obtain the final resized images. (2) The proposed image geolocalization method embeds the above image resizer as a fronting layer of the descriptor extraction network. It not only enables the network to be compatible with arbitrary-sized input images but also enhances the geometric features that are crucial to the image geolocalization task. Moreover, the triplet attention mechanism is added after the first convolutional layer of the backbone network to optimize the utilization of geometric elements extracted by the first convolutional layer. Finally, the local features extracted by the backbone network are aggregated to form image descriptors for image geolocalization. The proposed method was evaluated on several mainstream datasets, such as Pittsburgh30K, Tokyo24/7, and Places365. The results show that the proposed method has excellent size compatibility and compares favorably to recently mainstream geolocalization methods.

Keywords: image geolocalization, self-attention mechanism, image resizer, geometric feature

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242 The Effects of Nano Zerovalent Iron (nZVI) and Magnesium Oxide Nanoparticles on Methane Production during Anaerobic Digestion of Waste Activated Sludge

Authors: Passkorn Khanthongthip, John T. Novak

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Many studies have been reported that the nZVI and MgO NPs were often found in waste activated sludge (WAS). However, little is known about the impact of those NPs on WAS stabilization. The aims of this study were to investigate the effects of both NPs on WAS anaerobic digestion for methane production and to examine the change of metanogenic population under those different environments using qPCR. Four dosages (2, 50, 100, and 200 mg/g-TSS) of MgO NPs were added to four different bottles containing WAS to investigate the impact of MgO NPs on methane production during WAS anaerobic digestion. The effects of nZVI on methane production during WAS anaerobic digestion were also conducted in another four bottles using the same methods described above except that the MgO NPs were replaced by nZVI. A bottle of WAS anaerobic digestion without nanoparticles addition was also operated to serve as a control. It was found that the relative amounts, compared to the control system, of methane production in each WAS anaerobic digestion bottle adding 2, 50, 100, 200 mg/gTSS MgO NPs were 98, 62, 28, and 14 %, respectively. This suggests that higher MgO NPs resulted in lower methane production. The data of batch test for the effects of corresponding released Mg2+ indicated that 50 mg/gTSS MgO NPs or higher could inhibit methane production at least 25%. Moreover, the volatile fatty acid (VFA) concentration was 328, 384, 928, 3,684, and 7,848 mg/L for the control and four WAS anaerobic digestion bottles with 2, 50, 100, 200 mg/gTSS MgO NPs addition, respectively. Higher VFA concentration could reduce pH and subsequently decrease methanogen growth, resulting in lower methane production. The relative numbers of total gene copies of methanogens analyzed from samples taken from WAS anaerobic digestion bottles were approximately 99, 68, 38, and 24 % of control for the addition of 2, 50, 100, and 200 mg/gTSS, respectively. Obviously, the more MgO NPs appeared in sludge anaerobic digestion system, the less methanogens remained. In contrast, the relative amount of methane production found in another four WAS anaerobic digestion bottles adding 2, 50, 100, and 200 mg/gTSS nZVI were 102, 128, 112, and 104 % of the control, respectively. The measurement of methanogenic population indicated that the relative content of methanogen gene copies were 101, 132, 120, and 112 % of those found in control, respectively. Additionally, the cumulative VFA was 320, 234, 308, and 330 mg/L, respectively. This reveals that nZVI addition could assist to increase methanogenic population. Higher amount of methanogen accelerated VFA degradation for greater methane production, resulting in lower VFA accumulation in digesters. Moreover, the data for effects of corresponding released Fe2+ conducted by batch tests suggest that the addition of approximately 50 mg/gTSS nZVI increased methane production by 20%. In conclusion, the presence of MgO NPs appeared to diminish the methane production during WAS anaerobic digestion. Higher MgO NPs dosages resulted in more inhibition on methane production. In contrast, nZVI addition promoted the amount of methanogenic population which facilitated methane production.

Keywords: magnesium oxide nanoparticles, methane production, methanogenic population, nano zerovalent iron

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241 Detection of Glyphosate Using Disposable Sensors for Fast, Inexpensive and Reliable Measurements by Electrochemical Technique

Authors: Jafar S. Noori, Jan Romano-deGea, Maria Dimaki, John Mortensen, Winnie E. Svendsen

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Pesticides have been intensively used in agriculture to control weeds, insects, fungi, and pest. One of the most commonly used pesticides is glyphosate. Glyphosate has the ability to attach to the soil colloids and degraded by the soil microorganisms. As glyphosate led to the appearance of resistant species, the pesticide was used more intensively. As a consequence of the heavy use of glyphosate, residues of this compound are increasingly observed in food and water. Recent studies reported a direct link between glyphosate and chronic effects such as teratogenic, tumorigenic and hepatorenal effects although the exposure was below the lowest regulatory limit. Today, pesticides are detected in water by complicated and costly manual procedures conducted by highly skilled personnel. It can take up to several days to get an answer regarding the pesticide content in water. An alternative to this demanding procedure is offered by electrochemical measuring techniques. Electrochemistry is an emerging technology that has the potential of identifying and quantifying several compounds in few minutes. It is currently not possible to detect glyphosate directly in water samples, and intensive research is underway to enable direct selective and quantitative detection of glyphosate in water. This study focuses on developing and modifying a sensor chip that has the ability to selectively measure glyphosate and minimize the signal interference from other compounds. The sensor is a silicon-based chip that is fabricated in a cleanroom facility with dimensions of 10×20 mm. The chip is comprised of a three-electrode configuration. The deposited electrodes consist of a 20 nm layer chromium and 200 nm gold. The working electrode is 4 mm in diameter. The working electrodes are modified by creating molecularly imprinted polymers (MIP) using electrodeposition technique that allows the chip to selectively measure glyphosate at low concentrations. The modification included using gold nanoparticles with a diameter of 10 nm functionalized with 4-aminothiophenol. This configuration allows the nanoparticles to bind to the working electrode surface and create the template for the glyphosate. The chip was modified using electrodeposition technique. An initial potential for the identification of glyphosate was estimated to be around -0.2 V. The developed sensor was used on 6 different concentrations and it was able to detect glyphosate down to 0.5 mgL⁻¹. This value is below the accepted pesticide limit of 0.7 mgL⁻¹ set by the US regulation. The current focus is to optimize the functionalizing procedure in order to achieve glyphosate detection at the EU regulatory limit of 0.1 µgL⁻¹. To the best of our knowledge, this is the first attempt to modify miniaturized sensor electrodes with functionalized nanoparticles for glyphosate detection.

Keywords: pesticides, glyphosate, rapid, detection, modified, sensor

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240 Effectiveness of N-Acetylcysteine in the Treatment of Adults with Trichotillomania: An Evidenced Based Review

Authors: Teresa Sarmento de Beires, Sofia Padilha, Pedro Arantes, Joana Ribeiro, Andreia Eiras

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Background: Trichotillomania is a psychiatric condition that is very challenging to treat, with no first-line medications approved by any medical agency. It is defined as a recurrent compulsive habit of pulling out one's own hair, usually from the scalp and eyebrows area, but it can also affect eyelashes or any other hair-bearing area. N-acetylcysteine, a glutamate modulator, has been studied as a possible treatment for several psychiatric and neurological disorders, considering its role in attenuating pathophysiological processes responsible for compulsive behaviors and, therefore, trichotillomania. Objective: This study aims to determine the efficacy of N-acetylcysteine in the treatment of adults with trichotillomania. Methodology: The authors researched guidelines, standards of clinical guidance, systematic reviews, meta-analyses, and randomized clinical trials, published in the last 20 years using the MeSH terms: "Trichotillomania” and “N-acetylcysteine” in the following databases: PubMed, Cochrane library, National Guideline Clearing House, National Institute of Health and Care Excellence (NICE), Canadian Medical Association Practice Guidelines and Database of Abstracts of Reviews of Effectiveness (DARE). The Strength of Recommendation Taxonomy (SORT) Scale, from the American Family Physician, was used to evaluate the level of evidence and assign the strength of recommendation. Results: The research found fifteen articles, among which only three were eligible according to the inclusion criteria: 1. systematic review and 2. meta-analyses. There was evidence of a probable beneficial effect of N-acetylcysteine on treatment response and reduction of trichotillomania symptom severity in adults, with moderate certainty in the effect estimate. There was no evidence of effectiveness with the use of inositol, antioxidants, naltrexone, or selective serotonin reuptake inhibitors (SSRIs) in the treatment of adults with trichotillomania. Clomipramine and Olanzapine showed potential treatment benefits, with low certainty. N-acetylcysteine had the least severe side effect profile in adults compared with the other potentially beneficial pharmacological treatments. Conclusion: Evidence points towards the effectiveness of N-acetylcysteine in the treatment of adults with trichotillomania, which exhibits a good tolerability profile with minimal adverse effects. Therefore, the authors attribute a level of evidence 2, the strength of recommendation B, to the prescription of N-acetylcysteine in the treatment of adults suffering from trichotillomania (SORT analysis). Further investigation is needed in order to extract high-quality conclusions from the meta-analysis.

Keywords: trichotillomania, hair pulling, treatment, n-acetylcysteine

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239 Corrosion Behavior of Organic-Inorganic Hybrid Coatings Fabricated by Electrostatic Method

Authors: Mohammed Ahmed, Ziba Nazarlou

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Mild steels have a limited alloying content which makes them vulnerable to excessive corrosion rates in the harsh medium. To overcome this issue, some protective coatings are used to prevent corrosion on the steel surface. The use of specialized coatings, mainly organic coatings (such as epoxies, polyurethanes, and acrylics) and inorganic coatings (such as Polysiloxanes) is the most common method of mitigating corrosion of carbon steel. Incorporating the benefits of organic and inorganic hybrid (OIH) compounds for the designing of hybrid protective coatings is still challenging for industrial applications. There are advantages of inorganic coatings have, but purely inorganic siloxane-based coatings are difficult to use on industrial applications unless they are used at extremely low thicknesses (< 1-2 microns). Hence, most industrial applications try to have a combination of Polysiloxanes with organic compounds.  A hybrid coating possesses an organic section, which transports flexibility and impact resistance, and an inorganic section, which usually helps in the decreasing of porosity and increasing thermal stability and hardness. A number of polymers including polyethylene glycol and polyvinyl pyrrolidone have been reported to inhibit the corrosion mild steel in acidic media. However, reports on the effect of polyethylene oxide (PEO) or its blends on corrosion inhibition of metals is very scarce. Different composition of OIH coatings was synthesized by using silica sol-gel, epoxy, and PEO. The effect of different coating types on the corrosion behavior of carbon steel in harsh solution has been studied by weight loss and electrochemical measurements using Gamry 1000 Interface Potentiostat. Coating structures were investigated by SEM. İt revealed a considerable reduction in corrosion rate for coated sample. Based on these results, OIH coating prepared by epoxy-silica sol gel-PEO and epoxy-silica sol-gel exhibit had a %99.5 and %98 reduction of (Corrosion rate) CR compares to baseline. Cathodic Tafel constant (βc) shows that coatings change both Tafel constants but had more effect on the cathodic process. The evolution of the Potentiostatic scan with time displays stability in potential, some of them in a high value while the other in a low value which can be attributed to the formation of an oxide film covering substrate surface. The coated samples with the group of epoxy coating have a lower potential along with the time test, while the silica group shows higher in potential with respect to time.

Keywords: electrostatic, hybrid coating, corrosion tests, silica sol gel

Procedia PDF Downloads 118
238 Optimization of Culture Conditions of Paecilomyces Tenuipes, Entomopathogenic Fungi Inoculated into the Silkworm Larva, Bombyx Mori

Authors: Sung-Hee Nam, Kwang-Gill Lee, You-Young Jo, HaeYong Kweon

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Entomopathogenic fungi is a Cordyceps species that is isolated from dead silkworm and cicada. Fungi on cicadas were described in old Chinese medicinal books and From ancient times, vegetable wasps and plant worms were widely known to have active substance and have been studied for pharmacological use. Among many fungi belonging to the genus Cordyceps, Cordyceps sinensis have been demonstrated to yield natural products possessing various biological activities and many bioactive components. Generally, It is commonly used to replenish the kidney and soothe the lung, and for the treatment of fatigue. Due to their commercial and economic importance, the demand for Cordyceps has been rapidly increased. However, a supply of Cordyceps specimen could not meet the increasing demand because of their sole dependence on field collection and habitat destruction. Because it is difficult to obtain many insect hosts in nature and the edibility of host insect needs to be verified in a pharmacological aspect. Recently, this setback was overcome that P. tenuipes was able to be cultivated in a large scale using silkworm as host. Pharmacological effects of P. tenuipes cultured on silkworm such as strengthening immune function, anti-fatigue, anti-tumor activity and controlling liver etc have been proved. They are widely commercialized. In this study, we attempted to establish a method for stable growth inhibition of P. tenuipes on silkworm hosts and an optimal condition for synnemata formation. To determine optimum culturing conditions, temperature and light conditions were varied. The length and number of synnemata was highest at 25℃ temperature and 100~300 lux illumination. On an average, the synnemata of wild P. tenuipes measures 70 ㎜ in length and 20 in number; those of the cultured strain were relatively shorter and more in number. The number of synnemata may have increased as a result of inoculating the host with highly concentrated conidia, while the length may have decreased due to limited nutrition per individual. It is not able that changes in light illumination cause morphological variations in the synnemata. However, regulation of only light and temperature could not produce stromata like perithecia, asci, and ascospores. Yamanaka reported that although a complete fruiting body can be produced under optimal culture conditions, it should be regarded as synnemata because it does not develop into an ascoma bearing ascospores.

Keywords: paecilomyces tenuipes, entomopathogenic fungi, silkworm larva, bombyx mori

Procedia PDF Downloads 320
237 The Antioxidant Gel Mask Supplies Of Bitter Melon's Extract ( Momordica charantia Linn.)

Authors: N. S. Risqina, G. Edijanti, P. S. Nurita, L. Endang, R. A. Siti, R. Tri

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Skin is an important and vital organs and also as a mirror of health and life. Facial skin care is one of the main emphasis to get the beautiful, healthy, and fresh skin. Potentially antioxidant phenolic compounds shows, antimutagen, antitumor, anti-inflammatory, and anti-cancer. Flavonoids are a group of polyphenolic compounds that have the nature of free radicals, inhibiting the oxidative and hydrolytic enzymes as well as anti-inflammatory. Bitter melon (Momordica charantia Linn) is a plant that contains flavonoids, and phenolic antioxidant activity. Bitter melon has strong antioxidant activity that can counteract the free radicals.These compounds can prevent free radicals that cause premature aging. Gel masks including depth cleansing is the cosmetics which work in depth and could raise the dead skin cells. Measurement of antioxidant activity of the extract and gel mask is done by using the immersion method of DPPH. IC50 value of ethanol extract of bitter melon fruit of 287.932 ppm. The preparation of gel mask bitter melon fruit extract, necessary to test the effectiveness of antioxidants using DPPH method is done by measuring the inhibition of DPPH and using UV spectrophotometer at the wavelength of maximum DPPH solution. Tests conducted at the beginning and end of the evaluation (day 0 and day 28). The purpose of this study is to determine the antioxidant activity of the bitter melon's extract and to determine the antioxidant activity of ethanol extract gel mask pare in varying concentrations, ie 1xIC100 (0.295%), 2xIC100 (0.590%) and 4xIC100 (1.180%). Evaluation of physical properties of the preparation on (Day-0,7,14,21, and 28) and evaluation of antioxidant activity (day 0 and 28). Data were analyzed using One Way ANOVA to determine differences in the physical properties of each formula. The statistical results showed that differences in the formula and storage time affects the adhesion, dispersive power, dry time and pH it is shown on a significant value of p <0.05, but longer storage does not affect the pH because the significance value p> 0,05. The antioxidant test showed that there are differences in antioxidant activity in all formulas. Measurement of antioxidant activity of bitter melon fruit extract gel mask on day 0 with a concentration of 0.295%, 0.590%, and 1.180%, respectively, are 124,209.277 ppm, ppm 83819.223 and 47323.592 ppm, whereas day 28 consecutive 130 411, 495 ppm, and 53239.806 95561.645 ppm ppm. The Conclusions drawn that there are antioxidant activity in preparation gel mask of bitter melon fruit extract. The antioxidant activity of bitter melon fruit extract gel mask on the day 0 with a concentration of 0.295%, 0.590%, and 1.180%, respectively, are 124,209.277 ppm, ppm 83819.223 and 47323.592 ppm, whereas on day 28 of antioxidant activity gel mask bitter melon fruit extract with a concentration of 0.295%, 0.590%, and 1.180% in succession, namely: 130,411.495 ppm, ppm 95561.645 and 53239.806 ppm.

Keywords: antioxdant, bitter melon, gel mask, IC50

Procedia PDF Downloads 470
236 Identification of Natural Liver X Receptor Agonists as the Treatments or Supplements for the Management of Alzheimer and Metabolic Diseases

Authors: Hsiang-Ru Lin

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Cholesterol plays an essential role in the regulation of the progression of numerous important diseases including atherosclerosis and Alzheimer disease so the generation of suitable cholesterol-lowering reagents is urgent to develop. Liver X receptor (LXR) is a ligand-activated transcription factor whose natural ligands are cholesterols, oxysterols and glucose. Once being activated, LXR can transactivate the transcription action of various genes including CYP7A1, ABCA1, and SREBP1c, involved in the lipid metabolism, glucose metabolism and inflammatory pathway. Essentially, the upregulation of ABCA1 facilitates cholesterol efflux from the cells and attenuates the production of beta-amyloid (ABeta) 42 in brain so LXR is a promising target to develop the cholesterol-lowering reagents and preventative treatment of Alzheimer disease. Engelhardia roxburghiana is a deciduous tree growing in India, China, and Taiwan. However, its chemical composition is only reported to exhibit antitubercular and anti-inflammatory effects. In this study, four compounds, engelheptanoxides A, C, engelhardiol A, and B isolated from the root of Engelhardia roxburghiana were evaluated for their agonistic activity against LXR by the transient transfection reporter assays in the HepG2 cells. Furthermore, their interactive modes with LXR ligand binding pocket were generated by molecular modeling programs. By using the cell-based biological assays, engelheptanoxides A, C, engelhardiol A, and B showing no cytotoxic effect against the proliferation of HepG2 cells, exerted obvious LXR agonistic effects with similar activity as T0901317, a novel synthetic LXR agonist. Further modeling studies including docking and SAR (structure-activity relationship) showed that these compounds can locate in LXR ligand binding pocket in the similar manner as T0901317. Thus, LXR is one of nuclear receptors targeted by pharmaceutical industry for developing treatments of Alzheimer and atherosclerosis diseases. Importantly, the cell-based assays, together with molecular modeling studies suggesting a plausible binding mode, demonstrate that engelheptanoxides A, C, engelhardiol A, and B function as LXR agonists. This is the first report to demonstrate that the extract of Engelhardia roxburghiana contains LXR agonists. As such, these active components of Engelhardia roxburghiana or subsequent analogs may show important therapeutic effects through selective modulation of the LXR pathway.

Keywords: Liver X receptor (LXR), Engelhardia roxburghiana, CYP7A1, ABCA1, SREBP1c, HepG2 cells

Procedia PDF Downloads 420
235 A Computational Model of the Thermal Grill Illusion: Simulating the Perceived Pain Using Neuronal Activity in Pain-Sensitive Nerve Fibers

Authors: Subhankar Karmakar, Madhan Kumar Vasudevan, Manivannan Muniyandi

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Thermal Grill Illusion (TGI) elicits a strong and often painful sensation of burn when interlacing warm and cold stimuli that are individually non-painful, excites thermoreceptors beneath the skin. Among several theories of TGI, the “disinhibition” theory is the most widely accepted in the literature. According to this theory, TGI is the result of the disinhibition or unmasking of the pain-sensitive HPC (Heat-Pinch-Cold) nerve fibers due to the inhibition of cold-sensitive nerve fibers that are responsible for masking HPC nerve fibers. Although researchers focused on understanding TGI throughexperiments and models, none of them investigated the prediction of TGI pain intensity through a computational model. Furthermore, the comparison of psychophysically perceived TGI intensity with neurophysiological models has not yet been studied. The prediction of pain intensity through a computational model of TGI can help inoptimizing thermal displays and understanding pathological conditions related to temperature perception. The current studyfocuses on developing a computational model to predict the intensity of TGI pain and experimentally observe the perceived TGI pain. The computational model is developed based on the disinhibition theory and by utilizing the existing popular models of warm and cold receptors in the skin. The model aims to predict the neuronal activity of the HPC nerve fibers. With a temperature-controlled thermal grill setup, fifteen participants (ten males and five females) were presented with five temperature differences between warm and cold grills (each repeated three times). All the participants rated the perceived TGI pain sensation on a scale of one to ten. For the range of temperature differences, the experimentally observed perceived intensity of TGI is compared with the neuronal activity of pain-sensitive HPC nerve fibers. The simulation results show a monotonically increasing relationship between the temperature differences and the neuronal activity of the HPC nerve fibers. Moreover, a similar monotonically increasing relationship is experimentally observed between temperature differences and the perceived TGI intensity. This shows the potential comparison of TGI pain intensity observed through the experimental study with the neuronal activity predicted through the model. The proposed model intends to bridge the theoretical understanding of the TGI and the experimental results obtained through psychophysics. Further studies in pain perception are needed to develop a more accurate version of the current model.

Keywords: thermal grill Illusion, computational modelling, simulation, psychophysics, haptics

Procedia PDF Downloads 171
234 Effects of Starvation, Glucose Treatment and Metformin on Resistance in Chronic Myeloid Leukemia Cells

Authors: Nehir Nebioglu

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Chemotherapy is widely used for the treatment of cancer. Doxorubicin is an anti-cancer chemotherapy drug that is classified as an anthracycline antibiotic. Antitumor antibiotics consist of natural products produced by species of the soil fungus Streptomyces. These drugs act in multiple phases of the cell cycle and are known cell-cycle specific. Although DOX is a precious clinical antineoplastic agent, resistance is also a problem that limits its utility besides cardiotoxicity problem. The drug resistance of cancer cells results from multiple factors including individual variation, genetic heterogeneity within a tumor, and cellular evolution. The mechanism of resistance is thought to involve, in particular, ABCB1 (MDR1, Pgp) and ABCC1 (MRP1) as well as other transporters. Several studies on DOX-resistant cell lines have shown that resistance can be overcome by an inhibition of ABCB1, ABCC1, and ABCC2. This study attempts to understand the effects of different concentration levels of glucose treatment and starvation on the proliferation of Doxorubicin resistant cancer cells lines. To understand the effect of starvation, K562/Dox and K562 cell lines were treated with 0, 5 nM, 50 nM, 500 nM, 5 uM and 50 uM Dox concentrations in both starvation and normal medium conditions. In addition to this, to interpret the effect of glucose treatment, different concentrations (0, 1 mM, 5 mM, 25 mM) of glucose were applied to Dox-treated (with 0, 5 nM, 50 nM, 500 nM, 5 uM and 50 uM) K562/Dox and K652 cell lines. All results show significant decreasing in the cell count of K562/Dox, when cells were starved. However, while proliferation of K562/Dox lines decrease is associated with the increasingly applied Dox concentration, K562/Dox starved ones remain at the same proliferation level. Thus, the results imply that an amount of K562/Dox lines gain starvation resistance and remain resistant. Furthermore, for K562/Dox, there is no clear effect of glucose treatment in terms of cell proliferation. In the presence of a moderate level of glucose (5 mM), proliferation increases compared to other concentration of glucose for each different Dox application. On the other hand, a significant increase in cell proliferation in moderate level of glucose is only observed in 5 uM Dox concentration. The moderate concentration level of Dox can be examined in further studies. For the high amount of glucose (25 mM), cell proliferation levels are lower than moderate glucose application. The reason could be high amount of glucose may not be absorbable by cells. Also, in the presence of low amount of glucose, proliferation is decreasing in an orderly manner of increase in Dox concentration. This situation can be explained by the glucose depletion -Warburg effect- in the literature.

Keywords: drug resistance, cancer cells, chemotherapy, doxorubicin

Procedia PDF Downloads 176
233 Monitoring Key Biomarkers Related to the Risk of Low Breastmilk Production in Women, Leading to a Positive Impact in Infant’s Health

Authors: R. Sanchez-Salcedo, N. H. Voelcker

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Currently, low breast milk production in women is one of the leading health complications in infants. Recently, It has been demonstrated that exclusive breastfeeding, especially up to a minimum of 6 months, significantly reduces respiratory and gastrointestinal infections, which are the main causes of death in infants. However, the current data shows that a high percentage of women stop breastfeeding their children because they perceive an inadequate supply of milk, and only 45% of children are breastfeeding under 6 months. It is, therefore, clear the necessity to design and develop a biosensor that is sensitive and selective enough to identify and validate a panel of milk biomarkers that allow the early diagnosis of this condition. In this context, electrochemical biosensors could be a powerful tool for assessing all the requirements in terms of reliability, selectivity, sensitivity, cost efficiency and potential for multiplex detection. Moreover, they are suitable for the development of POC devices and wearable sensors. In this work, we report the development of two types of sensing platforms towards several biomarkers, including miRNAs and hormones present in breast milk and dysregulated in this pathological condition. The first type of sensing platform consists of an enzymatic sensor for the detection of lactose, one of the main components in milk. In this design, we used gold surface as an electrochemical transducer due to the several advantages, such as the variety of strategies available for its rapid and efficient functionalization with bioreceptors or capture molecules. For the second type of sensing platform, nanoporous silicon film (pSi) was chosen as the electrode material for the design of DNA sensors and aptasensors targeting miRNAs and hormones, respectively. pSi matrix offers a large superficial area with an abundance of active sites for the immobilization of bioreceptors and tunable characteristics, which increase the selectivity and specificity, making it an ideal alternative material. The analytical performance of the designed biosensors was not only characterized in buffer but also validated in minimally treated breastmilk samples. We have demonstrated the potential of an electrochemical transducer on pSi and gold surface for monitoring clinically relevant biomarkers associated with the heightened risk of low milk production in women. This approach, in which the nanofabrication techniques and the functionalization methods were optimized to increase the efficacy of the biosensor highly provided a foundation for further research and development of targeted diagnosis strategies.

Keywords: biosensors, electrochemistry, early diagnosis, clinical markers, miRNAs

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232 Anti-Neuroinflammatory and Anti-Apoptotic Efficacy of Equol, against Lipopolysaccharide Activated Microglia and Its Neurotoxicity

Authors: Lalita Subedi, Jae Kyoung Chae, Yong Un Park, Cho Kyo Hee, Lee Jae Hyuk, Kang Min Cheol, Sun Yeou Kim

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Neuroinflammation may mediate the relationship between low levels of estrogens and neurodegenerative disease. Estrogens are neuroprotective and anti-inflammatory in neurodegenerative disease models. Due to the long term side effects of estrogens, researches have been focused on finding an effective phytoestrogens for biological activities. Daidzein present in soybeans and its active metabolite equol (7-hydroxy-3-(4'-hydroxyphenyl)-chroman) bears strong antioxidant and anticancer showed more potent anti-inflammatory and neuroprotective role in neuroinflammatory model confirmed its in vitro activity with molecular mechanism through NF-κB pathway. Three major CNS cells Microglia (BV-2), Astrocyte (C6), Neuron (N2a) were used to find the effect of equol in inducible nitric oxide synthase (iNOS), cyclooxygenase (COX-2), MAPKs signaling proteins, apoptosis related proteins by western blot analysis. Nitric oxide (NO) and prostaglandin E2 (PGE2) was measured by the Gries method and ELISA, respectively. Cytokines like tumor necrosis factor-α (TNF-α) and IL-6 were also measured in the conditioned medium of LPS activated cells with or without equol. Equol inhibited the NO production, PGE-2 production and expression of COX-2 and iNOS in LPS-stimulated microglial cells at a dose dependent without any cellular toxicity. At the same time Equol also showed promising effect in modulation of MAPK’s and nuclear factor kappa B (NF-κB) expression with significant inhibition of the production of proinflammatory cytokine like interleukin -6 (IL-6), and tumor necrosis factor -α (TNF-α). Additionally, it inhibited the LPS activated microglia-induced neuronal cell death by downregulating the apoptotic phenomenon in neuronal cells. Furthermore, equol increases the production of neurotrophins like NGF and increase the neurite outgrowth as well. In conclusion the natural daidzein metabolite equol are more active than daidzein, which showed a promising effectiveness as an anti-neuroinflammatory and neuroprotective agent via downregulating the LPS stimulated microglial activation and neuronal apoptosis. This work was supported by Brain Korea 21 Plus project and High Value-added Food Technology Development Program 114006-4, Ministry of Agriculture, Food and Rural Affairs.

Keywords: apoptosis, equol, neuroinflammation, phytoestrogen

Procedia PDF Downloads 361
231 In Vivo Antiulcer and Anti-Helicobacter pylori Activity of Geraniol on Acetic Acid plus Helicobacter pylori Induced Ulcer in Rats

Authors: Subrat Kumar Bhattamisra, Vivian Lee Yean Yan, Chin Koh Lee, Chew Hui Kuean, Yun Khoon Liew, Mayuren Candasamy

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Geraniol, an acyclic monoterpenoid is the main active constituent in the essential oils of rose and palmorosa. Antioxidant, antibacterial, anticancer and antiulcer activity of geraniol was reported by many researchers. The present investigation was designed to study in vivo antiulcer and anti-Helicobacter pylori activity of geraniol. Antiulcer and anti-H. pylori activity of geraniol was evaluated on acetic acid plus H. pylori induced ulcer in rats. Acetic acid (0.03 mL) was injected to the sub-serosal layer of the stomach through laparotomy under anaesthesia. Orogastric inoculation of H. pylori (ATCC 43504) was done twice daily for 7 days. Geraniol (15 and 30 mg/kg), vehicle and standard drugs (Amoxicillin, 50 mg/kg; clarithromycin, 25 mg/kg & omeprazole, 20 mg/kg) was administered twice daily for 14 days. Antiulcer activity of geraniol was examined by the determination of gastric ulcer index, measuring the volume of gastric juice, pH and total acidity, myeloperoxidase activity and histopathological examination. Histopathological investigation for the presence of inflammation, white blood cell infiltration, edema, the mucosal damage was studied. The presence of H. pylori was detected by placing a biopsy sample from antral part of the stomach into rapid urease test. Ulcer index in H. pylori inoculated control group was 4.13 ± 0.85 and was significantly (P < 0.05) lowered in geraniol (30 mg/kg) and reference drug treated group. Geraniol increase the pH of the gastric juice (2.18 ± 0.13 in control vs. 4.14 ± 0.57 in geraniol 30mg/kg) and lower total acidity significantly (P < 0.01) in geraniol (15 & 30 mg/kg). Myeloperoxidase (MPO) activity was measured in stomach homogenate of all the groups. H. pylori control group has significant (P < 0.05) increase in MPO activity compared to normal control group. Geraniol (30 mg/kg) was showed significant (P < 0.05) and most effective among all the groups. Histopathological examination of rat stomach was scored and the total score for H. pylori control group was 8. After geraniol (30 mg/kg) and reference drug treatment, the histopathological score was significantly decreased and it was observed to be 3.5 and 2.0 respectively. Percentage inhibition of H. pylori infection in geraniol (30 mg/kg) and reference drug were found to be 40% and 50% respectively whereas, 100% infection in H. pylori control group was observed. Geraniol exhibited significant antiulcer and anti- H. pylori activity in the rats. Thus, geraniol has the potential for the further development as an effective medication in treating H. pylori associated ulcer.

Keywords: geraniol, helicobacter pylori atcc 43504, myeloperoxidase, ulcer

Procedia PDF Downloads 343
230 Envy and Schadenfreude Domains in a Model of Neurodegeneration

Authors: Hernando Santamaría-García, Sandra Báez, Pablo Reyes, José Santamaría-García, Diana Matallana, Adolfo García, Agustín Ibañez

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The study of moral emotions (i.e., Schadenfreude and envy) is critical to understand the ecological complexity of everyday interactions between cognitive, affective, and social cognition processes. Most previous studies in this area have used correlational imaging techniques and framed Schadenfreude and envy as monolithic domains. Here, we profit from a relevant neurodegeneration model to disentangle the brain regions engaged in three dimensions of Schadenfreude and envy: deservingness, morality, and legality. We tested 20 patients with behavioral variant frontotemporal dementia (bvFTD), 24 patients with Alzheimer’s disease (AD), as a contrastive neurodegeneration model, and 20 healthy controls on a novel task highlighting each of these dimensions in scenarios eliciting Schadenfreude and envy. Compared with the AD and control groups, bvFTD patients obtained significantly higher scores on all dimensions for both emotions. Interestingly, the legal dimension for both envy and Schadenfreude elicited higher emotional scores than the deservingness and moral dimensions. Furthermore, correlational analyses in bvFTD showed that higher envy and Schadenfreude scores were associated with greater deficits in social cognition, inhibitory control, and behavior. Brain anatomy findings (restricted to bvFTD and controls) confirmed differences in how these groups process each dimension. Schadenfreude was associated with the ventral striatum in all subjects. Also, in bvFTD patients, increased Schadenfreude across dimensions was negatively correlated with regions supporting social-value rewards, mentalizing, and social cognition (frontal pole, temporal pole, angular gyrus and precuneus). In all subjects, all dimensions of envy positively correlated with the volume of the anterior cingulate cortex, a region involved in processing unfair social comparisons. By contrast, in bvFTD patients, the intensified experience of envy across all dimensions was negatively correlated with a set of areas subserving social cognition, including the prefrontal cortex, the parahippocampus, and the amygdala. Together, the present results provide the first lesion-based evidence for the multidimensional nature of the emotional experiences of envy and Schadenfreude. Moreover, this is the first demonstration of a selective exacerbation of envy and Schadenfreude in bvFTD patients, probably triggered by atrophy to social cognition networks. Our results offer new insights into the mechanisms subserving complex emotions and moral cognition in neurodegeneration, paving the way for groundbreaking research on their interaction with other cognitive, social, and emotional processes.

Keywords: social cognition, moral emotions, neuroimaging, frontotemporal dementia

Procedia PDF Downloads 290
229 Refractory T-Cell Prolymphocytic Leukemia with JAK3 Mutation: In Vitro and Clinical Synergy of Tofacitinib and Ruxolitinib

Authors: Mike Wei, Nebu Koshy, Koen van Besien, Giorgio Inghirami, Steven M. Horwitz

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T-cell prolymphocytic leukemia (T-PLL) is a rare hematologic disease characterized by a T-cell phenotype, rapid progression, and poor prognosis with median survival of less than a year. Alemtuzumab-based chemotherapy has increased the rate of complete remissions but these are often short-lived, and allogeneic transplant is considered the only curative therapy. In recent studies, JAK3 activating mutations have been identified in T-cell cancers, with T-PLL having the highest rate of JAK3 mutations (30 – 42%). As such, T-PLL is a model disease for evaluating the utility of JAK3 inhibitors. We present a case of a 64-year-old man with relapsed-refractory T-PLL. He was initially treated with alemtuzumab and obtained complete response and was consolidated with matched unrelated donor stem cell transplant. His disease stayed in remission for approximately 1.5 years before relapse, which was then treated with a clinical trial of romidepsin-lenalidomide (partial responses then progression at 6 months) and later alemtuzumab. Due to complications of myelosuppression and CMV reactivation, his treatment was interrupted leading to disease progression. The doubling time of lymphocyte count was approximately 20 days and over a span of 60 days the lymphocyte count rose from 8 x 109/L to 68 x 109/L. Exon sequencing showed a JAK3 mutation. The patient consented to and was treated with FDA-approved tofacitinib (initially 5 mg BID, increased to 10 mg BID after 15 days of treatment). An initial decrease in lymphocyte count was followed by progression. In vitro treatment of the patient’s cells showed modest effects of tofacitinib and ruxolitinib as single agents, in the range of doxorubicin, but synergy between the agents. After 40 days of treatment with tofacitinib and with a lymphocyte count of 150 x 109/L, ruxolitinib (5mg BID) was added. Over the 60 days since dual inhibition was started, the lymphocyte count has stabilized. The patient has remained completely asymptomatic during treatment with tofacitinib and ruxolitinib. Neutrophil count has remained normal. Platelet count and hemoglobin have however declined from ~50 x109/L to ~30 x109/L and from 11 g/dL to 8.1 g/dL respectively, since the introduction of ruxolitinib. The stabilization in lymphocyte count confirms the clinical activity of JAK inhibitors in T-PLL as suggested by the presence of JAK3 mutations and by in-vitro assays. It also suggests clinical synergy between ruxolitinib and tofacitinib in this setting. Prospective studies of JAK inhibitors in PLL patients with formal dose-finding studies are needed.

Keywords: tofacitinib, ruxolitinib, T-cell prolymphocytic leukemia, JAK3

Procedia PDF Downloads 310
228 Efficacy and Safety of Computerized Cognitive Training Combined with SSRIs for Treating Cognitive Impairment Among Patients with Late-Life Depression: A 12-Week, Randomized Controlled Study

Authors: Xiao Wang, Qinge Zhang

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Background: This randomized, open-label study examined the therapeutic effects of computerized cognitive training (CCT) combined with selective serotonin reuptake inhibitors (SSRIs) on cognitive impairment among patients with late-life depression (LLD). Method: Study data were collected from May 5, 2021, to April 21, 2023. Outpatients who met diagnostic criteria for major depressive disorder according to the fifth revision of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) criteria (i.e., a total score on the 17-item Hamilton Depression Rating Scale (HAMD-17) ≥ 18 and a total score on the Montreal Cognitive Assessment scale (MOCA) <26) were randomly assigned to receive up to 12 weeks of CCT and SSRIs treatment (n=57) or SSRIs and Control treatment (n=61). The primary outcome was the change in Alzheimer's Disease Assessment Scale-Cognitive Subscale (ADAS-Cog) scores from baseline to week 12 between the two groups. The secondary outcomes included changes in the HAMD-17 score, Hamilton Anxiety Scale (HAMA) score and Neuropsychiatric Inventory (NPI) score. Mixed model repeated measures (MMRM) analysis was performed on modified intention-to-treat (mITT) and completer populations. Results: The full analysis set (FAS) included 118 patients (CCT and SSRIs group, n=57; SSRIs and Control group, n =61). Over the 12-week study period, the reduction in the ADAS-cog total score was significant (P < 0.001) in both groups, while MMRM analysis revealed a significantly greater reduction in cognitive function (ADAS-cog total scores) from baseline to posttreatment in the CCT and SSRIs group than in the SSRI and Control group [(F (1,115) =13.65, least-squares mean difference [95% CI]: −2.77 [−3.73, −1.81], p<0.001)]. There were significantly greater improvements in depression symptoms (measured by the HAMD-17) in the CCT and SSRIs group than in the control group [MMRM, estimated mean difference (SE) between groups −3.59 [−5.02, −2.15], p < 0.001]. The least-squares mean changes in the HAMA scores and NPI scores between baseline and week 8 were greater in the CCT and SSRIs group than in the control group (all P < 0.05). There was no significant difference between groups on response rates and remission rates by using the last-observation-carried-forward (LOCF) method (all P > 0.05). The most frequent adverse events (AEs) in both groups were dry mouth, somnolence, and constipation. There was no significant difference in the incidence of adverse events between the two groups. Conclusions: CCT combined with SSRIs was efficacious and well tolerated in LLD patients with cognitive impairment.

Keywords: late-life depression, cognitive function, computerized cognitive training, SSRIs

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227 Effect of 8-OH-DPAT on the Behavioral Indicators of Stress and on the Number of Astrocytes after Exposure to Chronic Stress

Authors: Ivette Gonzalez-Rivera, Diana B. Paz-Trejo, Oscar Galicia-Castillo, David N. Velazquez-Martinez, Hugo Sanchez-Castillo

Abstract:

Prolonged exposure to stress can cause disorders related with dysfunction in the prefrontal cortex such as generalized anxiety and depression. These disorders involve alterations in neurotransmitter systems; the serotonergic system—a target of the drugs that are commonly used as a treatment to these disorders—is one of them. Recent studies suggest that 5-HT1A receptors play a pivotal role in the serotonergic system regulation and in stress responses. In the same way, there is increasing evidence that astrocytes are involved in the pathophysiology of stress. The aim of this study was to examine the effects of 8-OH-DPAT, a selective agonist of 5-HT1A receptors, in the behavioral signs of anxiety and anhedonia as well as in the number of astrocytes in the medial prefrontal cortex (mPFC) after exposure to chronic stress. They used 50 male Wistar rats of 250-350 grams housed in standard laboratory conditions and treated in accordance with the ethical standards of use and care of laboratory animals. A protocol of chronic unpredictable stress was used for 10 consecutive days during which the presentation of stressors such as motion restriction, water deprivation, wet bed, among others, were used. 40 rats were subjected to the stress protocol and then were divided into 4 groups of 10 rats each, which were administered 8-OH-DPAT (Tocris, USA) intraperitoneally with saline as vehicle in doses 0.0, 0.3, 1.0 and 2.0 mg/kg respectively. Another 10 rats were not subjected to the stress protocol or the drug. Subsequently, all the rats were measured in an open field test, a forced swimming test, sucrose consume, and a cero maze test. At the end of this procedure, the animals were sacrificed, the brain was removed and the tissue of the mPFC (Bregma: 4.20, 3.70, 2.70, 2.20) was processed in immunofluorescence staining for astrocytes (Anti-GFAP antibody - astrocyte maker, ABCAM). Statistically significant differences were found in the behavioral tests of all groups, showing that the stress group with saline administration had more indicators of anxiety and anhedonia than the control group and the groups with administration of 8-OH-DPAT. Also, a dose dependent effect of 8-OH-DPAT was found on the number of astrocytes in the mPFC. The results show that 8-OH-DPAT can modulate the effect of stress in both behavioral and anatomical level. Also they indicate that 5-HT1A receptors and astrocytes play an important role in the stress response and may modulate the therapeutic effect of serotonergic drugs, so they should be explored as a fundamental part in the treatment of symptoms of stress and in the understanding of the mechanisms of stress responses.

Keywords: anxiety, prefrontal cortex, serotonergic system, stress

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226 Sustainable Nanoengineering of Copper Oxide: Harnessing Its Antimicrobial and Anticancer Capabilities

Authors: Yemane Tadesse Gebreslassie, Fisseha Guesh Gebremeskel

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Nanotechnology has made remarkable advancements in recent years, revolutionizing various scientific fields, industries, and research institutions through the utilization of metal and metal oxide nanoparticles. Among these nanoparticles, copper oxide nanoparticles (CuO NPs) have garnered significant attention due to their versatile properties and wide-range applications, particularly, as effective antimicrobial and anticancer agents. CuO NPs can be synthesized using different methods, including physical, chemical, and biological approaches. However, conventional chemical and physical approaches are expensive, resource-intensive, and involve the use of hazardous chemicals, which can pose risks to human health and the environment. In contrast, biological synthesis provides a sustainable and cost-effective alternative by eliminating chemical pollutants and allowing for the production of CuO NPs of tailored sizes and shapes. This comprehensive review focused on the green synthesis of CuO NPs using various biological resources, such as plants, microorganisms, and other biological derivatives. Current knowledge and recent trends in green synthesis methods for CuO NPs are discussed, with a specific emphasis on their biomedical applications, particularly in combating cancer and microbial infections. This review highlights the significant potential of CuO NPs in addressing these diseases. By capitalizing on the advantages of biological synthesis, such as environmental safety and the ability to customize nanoparticle characteristics, CuO NPs have emerged as promising therapeutic agents for a wide range of conditions. This review presents compelling findings, demonstrating the remarkable achievements of biologically synthesized CuO NPs as therapeutic agents. Their unique properties and mechanisms enable effective combating against cancer cells and various harmful microbial infections. CuO NPs exhibit potent anticancer activity through diverse mechanisms, including induction of apoptosis, inhibition of angiogenesis, and modulation of signaling pathways. Additionally, their antimicrobial activity manifests through various mechanisms, such as disrupting microbial membranes, generating reactive oxygen species, and interfering with microbial enzymes. This review offers valuable insights into the substantial potential of biologically synthesized CuO NPs as an alternative approach for future therapeutic interventions against cancer and microbial infections.

Keywords: copper oxide nanoparticles, green synthesis, nanotechnology, microbial infection

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225 Antibacterial Effect of Silver Diamine Fluoride Incorporated in Fissure Sealants

Authors: Nélio Veiga, Paula Ferreira, Tiago Correia, Maria J. Correia, Carlos Pereira, Odete Amaral, Ilídio J. Correia

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Introduction: The application of fissure sealants is considered to be an important primary prevention method used in dental medicine. However, the formation of microleakage gaps between tooth enamel and the fissure sealant applied is one of the most common reasons of dental caries development in teeth with fissure sealants. The association between various dental biomaterials may limit the major disadvantages and limitations of biomaterials functioning in a complementary manner. The present study consists in the incorporation of a cariostatic agent – silver diamine fluoride (SDF) – in a resin-based fissure sealant followed by the study of release kinetics by spectrophotometry analysis of the association between both biomaterials and assessment of the inhibitory effect on the growth of the reference bacterial strain Streptococcus mutans (S. mutans) in an in vitro study. Materials and Methods: An experimental in vitro study was designed consisting in the entrapment of SDF (Cariestop® 12% and 30%) into a commercially available fissure sealant (Fissurit®), by photopolymerization and photocrosslinking. The same sealant, without SDF was used as a negative control. The effect of the sealants on the growth of S. mutans was determined by the presence of bacterial inhibitory halos in the cultures at the end of the incubation period. In order to confirm the absence of bacteria in the surface of the materials, Scanning Electron Microscopy (SEM) characterization was performed. Also, to analyze the release profile of SDF along time, spectrophotometry technique was applied. Results: The obtained results indicate that the association of SDF to a resin-based fissure sealant may be able to increase the inhibition of S. mutans growth. However, no SDF release was noticed during the in vitro release studies and no statistical significant difference was verified when comparing the inhibitory halo sizes obtained for test and control group.  Conclusions: In this study, the entrapment of SDF in the resin-based fissure sealant did not potentiate the antibacterial effect of the fissure sealant or avoid the immediate development of dental caries. The development of more laboratorial research and, afterwards, long-term clinical data are necessary in order to verify if this association between these biomaterials is effective and can be considered for being used in oral health management. Also, other methodologies for associating cariostatic agents and sealant should be addressed.

Keywords: biomaterial, fissure sealant, primary prevention, silver diamine fluoride

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224 Designing Metal Organic Frameworks for Sustainable CO₂ Utilization

Authors: Matthew E. Potter, Daniel J. Stewart, Lindsay M. Armstrong, Pier J. A. Sazio, Robert R. Raja

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Rising CO₂ levels in the atmosphere means that CO₂ is a highly desirable feedstock. This requires specific catalysts to be designed to activate this inert molecule, combining a catalytic site tailored for CO₂ transformations with a support that can readily adsorb CO₂. Metal organic frameworks (MOFs) are regularly used as CO₂ sorbents. The organic nature of the linker molecules, connecting the metal nodes, offers many post-synthesis modifications to introduce catalytic active sites into the frameworks. However, the metal nodes may be coordinatively unsaturated, allowing them to bind to organic moieties. Imidazoles have shown promise catalyzing the formation of cyclic carbonates from epoxides with CO₂. Typically, this synthesis route employs toxic reagents such as phosgene, liberating HCl. Therefore an alternative route with CO₂ is highly appealing. In this work we design active sites for CO₂ activation, by tethering substituted-imidazole organocatalytic species to the available Cr3+ metal nodes of a Cr-MIL-101 MOF, for the first time, to create a tailored species for carbon capture utilization applications. Our tailored design strategy combining a CO₂ sorbent, Cr-MIL-101, with an anchored imidazole results in a highly active and selective multifunctional catalyst, achieving turnover frequencies of over 750 hr-1. These findings demonstrate the synergy between the MOF framework and imidazoles for CO₂ utilization applications. Further, the effect of substrate variation has been explored yielding mechanistic insights into this process. Through characterization, we show that the structural and compositional integrity of the Cr-MIL-101 has been preserved on functionalizing the imidazoles. Further, we show the binding of the imidazoles to the Cr3+ metal nodes. This can be seen through our EPR study, where the distortion of the Cr3+ on binding to the imidazole shows the CO₂ binding site is close to the active imidazole. This has a synergistic effect, improving catalytic performance. We believe the combination of MOF support and organocatalyst allows many possibilities to generate new multifunctional catalysts for CO₂ utilisation. In conclusion, we have validated our design procedure, combining a known CO₂ sorbent, with an active imidazole species to create a unique tailored multifunctional catalyst for CO₂ utilization. This species achieves high activity and selectivity for the formation of cyclic carbonates and offers a sustainable alternative to traditional synthesis methods. This work represents a unique design strategy for CO₂ utilization while offering exciting possibilities for further work in characterization, computational modelling, and post-synthesis modification.

Keywords: carbonate, catalysis, MOF, utilisation

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223 Endoscopic Stenting of the Main Pancreatic Duct in Patients With Pancreatic Fluid Collections After Pancreas Transplantation

Authors: Y. Teterin, S. Suleymanova, I. Dmitriev, P. Yartcev

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Introduction: One of the most common complications after pancreas transplantation are pancreatic fluid collections (PFCs), which are often complicated not only by infection and subsequent disfunction of the pancreatoduodenal graft (PDG), but also with a rather high mortality rate of recipients. Drainage is not always effective and often requires repeated open surgical interventions, which worsens the outcome of the surgery. Percutaneous drainage of PFCs combined with endoscopic stenting of the main pancreatic duct of the pancreatoduodenal graft (MPDPDG) showed high efficiency in the treatment of PFCs. Aims & Methods: From 01.01.2012 to 31.12.2021 at the Sklifosovsky Research Institute for Emergency Medicine were performed 64 transplantations of PDG. In 11 cases (17.2%), the early postoperative period was complicated by the formation of PFCs. Of these, 7 patients underwent percutaneous drainage of pancreonecrosis with high efficiency and did not required additional methods of treatment. In the remaining 4 patients, drainage was ineffective and was an indication for endoscopic stenting of the MPDPDG. They were the ones who made up the study group. Among them were 3 men and 1 woman. The mean age of the patients was 36,4 years.PFCs in these patients formed on days 1, 12, 18, and 47 after PDG transplantation. We used a gastroscope to stent the MPDPDG, due to anatomical features of the location of the duodenoduodenal anastomosis after PDG transplantation. Through the endoscope channel was performed selective catheterization of the MPDPDG, using a catheter and a guidewire, followed by its contrasting with a water-soluble contrast agent. Due to the extravasation of the contrast, was determined the localization of the defect in the PDG duct system. After that, a plastic pancreatic stent with a diameter of 7 Fr. and a length of 7 cm. was installed along guidewire. The stent was installed in such a way that its proximal edge completely covered the defect zone, and the distal one was determined in the intestinal lumen. Results: In all patients PDG pancreaticography revealed extravasation of a contrast in the area of the isthmus and body of the pancreas, which required stenting of the MPDPDG. In 1 (25%) case, the patient had a dislocation of the stent into the intestinal lumen (III degree according to Clavien-Dindo (2009)). This patient underwent repeated endoscopic stenting of the MPDPDG. On average 23 days after endoscopic stenting of the MPDPDG, the drainage tubes were removed and after approximately 40 days all patients were discharged in a satisfactory condition with follow-up endocrinologist and surgeon consultation. Pancreatic stents were removed after 6 months ± 7 days. Conclusion: Endoscopic stenting of the main pancreatic duct of the donor pancreas is by far the most highly effective and minimally invasive method in the treatment of PFCs after transplantation of the pancreatoduodenal complex.

Keywords: pancreas transplantation, endoscopy surgery, diabetes, stenting, main pancreatic duct

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222 An Energy and Economic Comparison of Solar Thermal Collectors for Domestic Hot Water Applications

Authors: F. Ghani, T. S. O’Donovan

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Today, the global solar thermal market is dominated by two collector types; the flat plate and evacuated tube collector. With regards to the number of installations worldwide, the evacuated tube collector is the dominant variant primarily due to the Chinese market but the flat plate collector dominates both the Australian and European markets. The market share of the evacuated tube collector is, however, growing in Australia due to a common belief that this collector type is ‘more efficient’ and, therefore, the better choice for hot water applications. In this study, we investigate this issue further to assess the validity of this statement. This was achieved by methodically comparing the performance and economics of several solar thermal systems comprising of; a low-performance flat plate collector, a high-performance flat collector, and an evacuated tube collector coupled with a storage tank and pump. All systems were simulated using the commercial software package Polysun for four climate zones in Australia to take into account different weather profiles in the study and subjected to a thermal load equivalent to a household comprising of four people. Our study revealed that the energy savings and payback periods varied significantly for systems operating under specific environmental conditions. Solar fractions ranged between 58 and 100 per cent, while payback periods range between 3.8 and 10.1 years. Although the evacuated tube collector was found to operate with a marginally higher thermal efficiency over the selective surface flat plate collector due to reduced ambient heat loss, the high-performance flat plate collector outperformed the evacuated tube collector on thermal yield. This result was obtained as the flat plate collector possesses a significantly higher absorber to gross collector area ratio over the evacuated tube collector. Furthermore, it was found for Australian regions operating with a high average solar radiation intensity and ambient temperature, the lower performance collector is the preferred choice due to favorable economics and reduced stagnation temperature. Our study has provided additional insight into the thermal performance and economics of the two prevalent solar thermal collectors currently available. A computational investigation has been carried out specifically for the Australian climate due to its geographic size and significant variation in weather. For domestic hot water applications were fluid temperatures between 50 and 60 degrees Celsius are sought, the flat plate collector is both technically and economically favorable over the evacuated tube collector. This research will be useful to system design engineers, solar thermal manufacturers, and those involved in policy to encourage the implementation of solar thermal systems into the hot water market.

Keywords: solar thermal, energy analysis, flat plate, evacuated tube, collector performance

Procedia PDF Downloads 210