Search results for: hematopoietic stem cell transplant

Authors: Foo Shen Hwang, Thomas Confrey, Stephen Scully, Barry Flannery

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Thermal characterization plays an important role in battery pack design. Lithium-ion batteries have to be maintained between 15-35 °C to operate optimally. Heat is generated (Q) internally within the batteries during both the charging and discharging phases. This can be quantified using several standard methods. The most common method of calculating the batteries heat generation is through the addition of both the joule heating effects and the entropic changes across the battery. In addition, such values can be derived by identifying the open-circuit voltage (OCV), nominal voltage (V), operating current (I), battery temperature (T) and the rate of change of the open-circuit voltage in relation to temperature (dOCV/dT). This paper focuses on experimental characterization and comparative modelling of the heat generation rate (Q) across several current discharge rates (0.5C, 1C, and 1.5C) of a 18650 cell. The analysis is conducted utilizing several non-linear mathematical functions methods, including polynomial, exponential, and power models. Parameter fitting is carried out over the respective function orders; polynomial (n = 3~7), exponential (n = 2) and power function. The generated parameter fitting functions are then used as heat source functions in a 3-D computational fluid dynamics (CFD) solver under natural convection conditions. Generated temperature profiles are analyzed for errors based on experimental discharge tests, conducted at standard room temperature (25°C). Initial experimental results display low deviation between both experimental and CFD temperature plots. As such, the heat generation function formulated could be easier utilized for larger battery applications than other methods available.

Keywords: computational fluid dynamics, curve fitting, lithium-ion battery, voltage drop

Procedia PDF Downloads 97

Authors: Ena Arora, Rong Fan, Aleksandr Fuks, Kolawole Felix Akinnawonu

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Introduction: Leiomyomas are benign tumors that are derived from the overgrowth of uterine smooth muscle cells. Women with symptomatic leiomyomas who desire future fertility, myomectomy should be the standard surgical treatment. Perioperative hemorrhage is a common complication in myomectomy. We performed the study to investigate blood transfusion rate in abdominal myomectomies, risk factors influencing blood loss and modalities to improve perioperative blood loss. Methods: Retrospective chart review was done for patients who underwent myomectomy from 2016 to 2022 at Queens hospital center, New York. We looked at preoperative patient demographics, clinical characteristics, intraoperative variables, and postoperative outcomes. Mann-Whitney U test were used for parametric and non-parametric continuous variable comparisons, respectively. Results: A total of 159 myomectomies were performed between 2016 and 2022, including 1 laparoscopic, 65 vaginal and 93 abdominal. 44 patients received blood transfusion during or within 72 hours of abdominal myomectomy. The blood transfusion rate was 47.3%. Blood transfusion rate was found to be twice higher than the average documented rate in literature which is 20%. Risk factors identified were black race, preoperative hematocrit<30%, preoperative blood transfusion within 72 hours, large fibroid burden, prolonged surgical time, and abdominal approach. Conclusion: Preoperative optimization with iron supplements or GnRH agonists is important for patients undergoing myomectomy. Interventions to decrease intra operative blood loss should include cell saver, tourniquet, vasopressin, misoprostol, tranexamic acid and gelatin-thrombin matrix hemostatic sealant.

Keywords: myomectomy, perioperative blood loss, cell saver, tranexamic acid

Procedia PDF Downloads 87

Authors: Ya'u Muhammad, Umar Umar A. Mallammadori, Dahiru Mansur

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Effect of kaempferol on haematological parameters in two weeks old broiler chickens with experimental Eimeria tenella infection was evaluated in this study. Sixty-day old broilers were randomly allotted into six groups (I-VI) of ten broilers each and brooded for two weeks with commercial broiler feed (vital feed®) and provided water ad libitum. At two weeks of age broilers in group 1 were neither infected nor treated. Broilers in groups II-VI were infected with Eimeria tenella sporulated oocyst (104/ml) via oral inoculation. After infection was established, broilers in groups II-IV were treated orally with 1 mg/kg, 1.5 mg/kg, and 2 mg/kg of kaempferol, respectively. Broilers in group V were treated for five days with amprolium, 1.25 g/L in drinking water. Broilers in group VI were administered normal saline, 5 ml/kg per os for five days. Five days post infection; all broilers were sacrificed by severing their jugular veins. Blood sample from each bird was collected in EDTA container for haematology. Caecal contents were harvested and used to determine the lesion score and caecal Oocyst count respectively. Data obtained was analyzed using pad prism version 5.0. Mean Packed Cell Volume (PCV), haemoglobin (Hb) concentration, and Red Blood Cell (RBC) count significantly (P < 0.05) increased in groups II, III, and IV in a dose dependent manner. Similarly, PCV, Hb concentration, and RBC count significantly (P < 0.05) increased in groups II, III, and IV when compared to VI. No significant (P > 0.05) difference in the mean values of PCV, Hb and RBC count were recorded between groups treated with kaempferol and group V. Caecal Oocyst counts and lesion scores reduced significantly (P < 0.05) in groups II, III, and IV in a dose dependent manner. It was therefore observed in this study that kaempferol improved haematological parameters and reduced Oocyst count as well as the lesion scores in broilers infected with Eimeria tenella.

Keywords: broilers, Eimeria tenella, kaempferol, lesion scores, oocyst count,

Procedia PDF Downloads 198

Authors: Jerzy Smardzewski

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Structures with negative Poisson's ratios are called auxetic. They are characterized by better mechanical properties than conventional structures, especially shear strength, the ability to better absorb energy and increase strength during bending, especially in sandwich panels. Commonly used paper cores of cellular boards are made of hexagonal cells. With isotropic facings, these cells provide isotropic properties of the entire furniture board. Shelves made of such panels with a thickness similar to standard chipboards do not provide adequate stiffness and strength of the furniture. However, it is possible to transform the shape of hexagonal cells into polyhedral auxetic cells that improve the mechanical properties of the core. The work aimed to transform the hexagonal cells of the paper core into auxetic cells and determine their basic mechanical properties. Using numerical methods, it was decided to design the most favorable proportions of cells distinguished by the lowest Poisson's ratio and the highest modulus of linear elasticity. Standard cores for cellular boards commonly used to produce 34 mm thick furniture boards were used for the tests. Poisson's ratios, bending strength, and linear elasticity moduli were determined for such cores and boards. Then, the cells were transformed into auxetic structures, and analogous cellular boards were made for which mechanical properties were determined. The results of numerical simulations for which the variable parameters were the dimensions of the cell walls, wall inclination angles, and relative cell density were presented in the further part of the paper. Experimental tests and numerical simulations showed the beneficial effect of auxeticization on the mechanical quality of furniture panels. They allowed for the selection of the optimal shape of auxetic core cells.

Keywords: auxetics, honeycomb, panels, simulation, experiment

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Authors: Mahmut Sozmen, Alparslan Kadir Devrim, Yonca Betil Kabak, Tuba Devrim

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Acute myocardial infarction is the leading cause of deaths in the worldwide. Mature cardiomyocytes do not have the ability to regenerate instead fibrous tissue proliferate and granulation tissue to fill out. Periostin is an extracellular matrix protein from fasciclin family and it plays an important role in the cell adhesion, migration, and growth of the organism. Periostin prevents apoptosis while stimulating cardiomyocytes. The main objective of this project is to investigate the effects of the recombinant murine periostin peptide administration for the cardiomyocyte regeneration in a rat model of acute myocardial infarction. The experiment was performed on 84 male rats (6 months old) in 4 group each contains 21 rats. Saline applied subcutaneously (1 ml/kg) two times with 24 hours intervals to the rats in control group (Group 1). Recombinant periostin peptide (1 μg/kg) dissolved in saline applied intraperitoneally in group 2 on 1, 3, 7, 14 and 21. days on same dates in group 4. Isoproterenol dissolved in saline applied intraperitoneally (85mg/kg/day) two times with 24 hours intervals to the groups 3 and 4. Rats in group 4 further received recombinant periostin peptide (1 μg/kg) dissolved in saline intraperitoneally starting one day after the final isoproterenol administration on days 1, 3, 7, 14 and 21. Following the final application of periostin rats continued to feed routinely with pelleted chow and water ad libitum for further seven days. At the end of 7th day rats sacrificed, blood and heart tissue samples collected for the immunohistochemical and biochemical analysis. Angiogenesis in response to tissue damage, is a highly dynamic process regulated by signals from the surrounding extracellular matrix and blood serum. In this project, VEGF, ANGPT, bFGF, TGFβ are the key factors that contribute to cardiomyocyte regeneration were investigated. Additionally, the relationship between mitosis and apoptosis (Bcl-2, Bax, PCNA, Ki-67, Phopho-Histone H3), cell cycle activators and inhibitors (Cyclin D1, D2, A2, Cdc2), the origin of regenerating cells (cKit and CD45) were examined. Present results revealed that periostin stimulated cardiomyocye cell-cycle re-entry in both normal and MCA damaged cardiomyocytes and increased angiogenesis. Thus, periostin contributes to cardiomyocyte regeneration during the healing period following myocardial infarction which provides a better understanding of its role of this mechanism, improving recovery rates and it is expected to contribute the lack of literature on this subject. Acknowledgement: This project was financially supported by Turkish Scientific Research Council- Agriculture, Forestry and Veterinary Research Support Group (TUBİTAK-TOVAG; Project No: 114O734), Ankara, TURKEY.

Keywords: cardiotoxicity, immunohistochemistry, isoproterenol, periostin

Procedia PDF Downloads 238

Authors: Szu-Chieh Yu, Pei-Chin Chiand, Chih-Yi Lin, Yi-Wen Chien

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UV radiation from sunlight cause numbers of acute and chronic skin damage which can result in inflammation, immune changes, physical changes and DNA damage that facilitates skin aging and the development of skin carcinogenesis. Reactive oxygen species (ROS) are generated by excessive solar UV radiation, resulting in oxidative damage to cellar components, proteins, lipids, and nucleic acids. Thus, antioxidation plays an important role that protects skin against ROS-induced injury. Safflower (Carthamus tinctorius L.) is an important Chinese medicine contained abundance flavones and hydroxysafflor yellow A (HSYA) which is main active ingredient. HSYA is part of quinochalcone and has unique structures of hydroxy groups that provided the antioxidant effect. In this study, the aim was to investigate the protective role of HYSA in human keratinocytes (HaCaT) against UVA-induced oxidative damage and the possible mechanism. The HaCaT cells were UVA-irradiated and the effects of HYSA on cell viability, reactive oxygen species generation, DNA fragmentation and lipid peroxidation were measured. The mRNA expression of matrix metalloproteinase Ι (MMP Ι), cyclooxygenase-2 (COX-2) were determined by RT-PCR. In this study, UVA exposure lead to decrease in cell viability and increase in reactive oxygen species generation in HaCaT cells. HYSA could effectively increase the viability of HaCaT cells after UVA exposure and protect them from UVA-induced oxidative stress. Moreover, HYSA can reduce inflammation through inhibition the mRNA expression of MMP Ι and COX-2. Our results suggest that HSYA can act as a free radical scavenger while keratinocytes were photodamaged. HYSA could be a useful natural medicine for the protection of epidermal cells from UVA-induced damage and will be developed into products for skin care.

Keywords: HaCaT keratinocytes, hydroxysafflor yellow A (HSYA), MMP Ι, oxidative stress

Procedia PDF Downloads 381

Authors: Devinder Kaur Sugga, Ekamdeep Kaur, Jaspreet Kaur, C. Rajesh, Preeti Rajesh, Harsimran Kaur

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Withanolides are steroidal lactones and are highly oxygenated phytoconstituents that can be developed as potential anti-carcinogenic agents. The two main withanolides, namely Withaferin A and Withanolides D, have been extensively studied for their pharmacological activities. Both these withanolides are present in the Withania somnifera (WS) leaves belonging to the family Solanaceae, also known as “Indian ginseng .”In this study effects of WS leaf extract on the MCF7 breast cancer cell line were investigated by performing a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay to evaluate the cytotoxic effects and in vitro wound-healing assay to study the effect on cancer cell migration. Our data suggest WS extracts have cytotoxic effects and are effective anti-migrating agents and thus can be a source of potential candidates for the development of potential agents against metastasis. Thus, it can be a source of potential candidates for the development of potential agents against metastasis. Insight into these results, the in-silico approach to identify the possible protein targets interacting with withanolides was taken. Protein kinase C alpha (PKCα) was among the selected 5 top-ranked target proteins identified by the Swiss Target Prediction tool. PKCα is known to promote the growth and invasion of cancer cells and is being evaluated as a prognostic biomarker and therapeutic target in clinically aggressive tumors. Molecular docking of Withaferin A and Withanolides D was performed using AutoDock Vina. Both the bioactive compounds interacted with PKCα. The targets predicted using this approach will serve as leads for the possible therapeutic potential of withanolides, the bioactive ingredients of WS extracts, as anti-cancer drugs.

Keywords: withania somnifera, withaferin A, withanolides D, PKCα

Procedia PDF Downloads 150

Authors: Leda Maria Costa Pereira, Maria Denise Lopes, Nucharin Songsasen

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Mammalian ovaries contain thousands of follicles that eventually degenerate or die after culture in vitro. Caspase-3 is a key enzyme that regulating cell death. Our objective was to examine the influence of anti-apoptotic drug Z-VAD-FMK (pan-caspase inhibitor) on in vitro viability of dog follicles within the ovarian cortex. Ovaries were obtained from prepubertal (age, 2.5–6 months) and adult (age, 8 months to 2 years) bitches and ovarian cortical fragments were recovered. The cortices were then incubated on 1.5% (w/v) agarose gel blocks within a 24-wells culture plate (three cortical pieces/well) containing Minimum Essential Medium Eagle - Alpha Modification (Alpha MEM) supplemented with 4.2 µg/ml insulin, 3.8 µg/ml transferrin, 5 ng/ml selenium, 2 mM L-glutamine, 100 µg/mL of penicillin G sodium, 100 µg/mL of streptomycin sulfate, 0.05 mM ascorbic acid, 10 ng/mL of FSH and 0.1% (w/v) polyvinyl alcohol in humidified atmosphere of 5% CO2 and 5% O2. The cortices were divided in six treatment groups: 1) 10 ng/mL EGF (EGF V0); 2) 10 ng/mL of EGF plus 1 mM Z-VAD-FMK (EGF V1); 3) 10 ng/mL of EGF and 10 mM Z-VAD-FMK (EGF V10); 4) 1 mM Z-VAD-FMK; 5) 10 mM Z-VAD-FMK and (6) no EGF and Z-VAD-FMK supplementation. Ovarian follicles within the tissues were processed for histology and assessed for follicle density, viability (based on morphology) and diameter immediately after collection (Control) or after 3 or 7 days of in vitro incubation. Comparison among fresh and culture treatment group was performed using ANOVA test. There were no differences (P > 0.05) in follicle density and viability among different culture treatments. However, there were differences in this parameter between culture days. Specifically, culturing tissue for 7 days resulted in significant reduction in follicle viability and density, regardless of treatments. We found a difference in size between culture days when these follicles were cultured using 10 mM Z-VAD-FMK or 10 ng/mL EGF (EGF V0). In sum, the finding demonstrated that Z-VAD-FMK at the dosage used in the present study does not provide the protective effect to ovarian tissue during in vitro culture. Future studies should explore different Z-VAD-FMK dosages or other anti-apoptotic agent, such as surviving in protecting ovarian follicles against cell death.

Keywords: anti apoptotic drug, bitches, follicles, Z-VAD-FMK

Procedia PDF Downloads 364

Authors: Gloria M. Ntuba-Jua, Afui M. Mih, Eneke E. T. Bechem

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Prunus africana (Hook. F.) Kalkman, commonly known as Pygeum or African cherry belongs to the Rosaceae family. It is a medium to large, evergreen tree with a spreading crown of 10 to 20 m. It is used by the traditional medical practitioners for the treatment of over 45ailments in Cameroon and sub-Sahara Africa. In modern medicine, it is used in the treatment of benign prostrate hyperplasia (BPH), prostate gland hypertrophy (enlarged prostate glands). This is possible because of its ability to produce some secondary metabolites which are believed to have bioactivity against these ailments. The ready international market for the sale of Prunus bark, uncontrolled exploitation, illegal harvesting using inappropriate techniques and poor timing of harvesting have contributed enormously to making the plant endangered. It is known to harbor a large number of endophytic fungi with the potential to produce similar secondary metabolites as the parent plant. Alternative sourcing of medicinal principles through endophytic fungi requires succinct knowledge of the endophytic fungi. This will serve as a conservation measure for Prunus africana by reducing dependence on Prunus bark for such metabolites. This work thus sought to compare the production of some major secondary metabolites produced by P. africana and some of its associated endophytic fungi. The leaves and stem bark of the plant from different provenances were soaked in methanol for 72 hrs to yield the methanolic crude extract. The phytochemical screening of the methanolic crude extracts using different standard procedures revealed the presence of tannins, flavonoids, terpenoids, saponins, phenolics and steroids. Pure cultures of some predominantly isolated endophyte species from the difference Prunus provenances such as Curvularia sp, and Morphospecies P001 were also grown in Potato Dextrose Broth (PDB) for 21 days and later extracted with Methylene dichloride (MDC) solvent after 24hrs to produce crude culture extracts. Qualitative assessment of crude culture extracts showed the presence of tannins, terpenoids, phenolics and steroids particularly β-Sitosterol, (a major bioactive metabolite) as did the plant tissues. Qualitative analysis by thin layer chromatography (TLC) was done to confirm and compare the production of β-Sitosterol (as marker compounds) in the crude extracts of the plant and endophyte. Samples were loaded on TLC silica gel aluminium barked plate (Kieselgel 60 F254, 0.2 mm, Merck) using acetone/hexane, (3.0:7.0) solvent system. They were visualized under an ultra violet lamp (UV254 and UV360). TLC revealed that leaves had a higher concentration of β-sitosterol in terms of band intensity than stem barks from the different provenances. The intensity of β-sitosterol bands in the culture extracts of endophytes was comparable to the plant extracts except for Curvularia sp (very minute) whose band was very faint. The ability of these fungi to make β-sitosterol was confirmed by TLC analysis with the compound having chromatographic properties (retention factor) similar to those of β-sitosterol standard. The ability of these major endophytes to produce secondary metabolites similar to the host has therefore been demonstrated. There is, therefore, the potential of developing the in vitro production system of Prunus secondary metabolites thereby enhancing its conservation.

Keywords: Caneroon, endophytic fungi, Prunus africana, secondary metabolite

Procedia PDF Downloads 237

Authors: Peter Kus, Anna Ostroverkh, Yurii Yakovlev, Yevheniia Lobko, Roman Fiala, Ivan Khalakhan, Vladimir Matolin

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Hydrogen economy is a concept of low-emission society which harvests most of its energy from renewable sources (e.g., wind and solar) and in case of overproduction, electrochemically turns the excess amount into hydrogen, which serves as an energy carrier. Proton exchange membrane water electrolyzers (PEMWE) are the backbone of this concept. By fast-response electricity to hydrogen conversion, the PEMWEs will not only stabilize the electrical grid but also provide high-purity hydrogen for variety of fuel cell powered devices, ranging from consumer electronics to vehicles. Wider commercialization of PEMWE technology is however hindered by high prices of noble metals which are necessary for catalyzing the redox reactions within the cell. Namely, platinum for hydrogen evolution reaction (HER), running on cathode, and iridium for oxygen evolution reaction (OER) on anode. Possible way of how to lower the loading of Pt and Ir is by using conductive high-surface nanostructures as catalyst supports in conjunction with thin-film catalyst deposition. The presented study discusses unconventional technique of membrane electron assembly (MEA) preparation. Noble metal catalysts (Pt and Ir) were magnetron sputtered in very low loadings onto the surface of porous sublayers (located on gas diffusion layer or directly on membrane), forming so to say localized three-phase boundary. Ultrasonically sprayed corrosion resistant TiC-based sublayer was used as a support material on anode, whereas magnetron sputtered nanostructured etched nitrogenated carbon (CNx) served the same role on cathode. By using this configuration, we were able to significantly decrease the amount of noble metals (to thickness of just tens of nanometers), while keeping the performance comparable to that of average state-of-the-art catalysts. Complex characterization of prepared supported catalysts includes in-cell performance and durability tests, electrochemical impedance spectroscopy (EIS) as well as scanning electron microscopy (SEM) imaging and X-ray photoelectron spectroscopy (XPS) analysis. Our research proves that magnetron sputtering is a suitable method for thin-film deposition of electrocatalysts. Tested set-up of thin-film supported anode and cathode catalysts with combined loading of just 120 ug.cm⁻² yields remarkable values of specific current. Described approach of thin-film low-loading catalyst deposition might be relevant when noble metal reduction is the topmost priority.

Keywords: hydrogen economy, low-loading catalyst, magnetron sputtering, proton exchange membrane water electrolyzer

Procedia PDF Downloads 164

Authors: Quin Emparan, Razif Harun, Dayang R. A. Biak, Rozita Omar, Michael K. Danquah

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Cultivation of immobilized microalgae cells is on the rise for biotechnological applications. In this study, cultivation of Chlorella vulgaris was carried out in the form of suspended free-cell and immobilized cells system. NaCS-PDMDAAC capsules were used to immobilize C. vulgaris. Initially, the synthesized NaCS with C. vulgaris culture were prepared at various concentration of 5- 20% (w/v) using a 6% hardening solution (PDMDAAC) to investigate the capsules' gel stability and suitability for microalgae cells growth. Then, the capsules produced from 15% NaCS with C. vulgaris culture were furthered investigated using 5%, 10%, and 15% (w/v) of PDMDAAC solution. The capsules' gel stability was evaluated through dissolution time and loss of uniform spherical shape of capsules, while suitability for microalgae cells growth was evaluated through the optical density of microalgae. In this study, the 15% NaCS-10% PDMDAAC capsules were found to be the most suitable to sustain the capsules' gel stability and microalgae cells growth in MLA. For that reason, the C. vulgaris immobilized in the 15% NaCS-10% PDMDAAC capsules were further characterized using physicochemical analysis in terms of morphological, carbon (C), hydrogen (H) and nitrogen (N), Fourier transform-infrared (FT-IR), scanning electron microscopy-energy dispersive X-ray (SEM-EDX), zeta potential and Brunauer-Emmet-Teller (BET) analyses. The results revealed that the presence of sulfonates in the synthesized NaCS and NaCS-PDMDAAC capsules without and with C. vulgaris proves that cellulose alcohol group was successfully bonded by sulfo group. Besides that, immobilized microalgae cells have a smaller cell size of 6.29 ± 1.09 µm and zeta potential of -11.93 ± 0.91 mV than suspended free-cells microalgae culture. It can be summarized that immobilization of C. vulgaris in the 15% NaCS-10% PDMDAAC capsules are relevant as a bioremediator for wastewater treatment purposes due to its suitable size of pore and capsules as well as structural and compositional properties.

Keywords: biological capsules, immobilized cultivation, microalgae, physico-chemical analysis

Procedia PDF Downloads 173

Authors: Manal Farea, Adam Husein, Ahmad S. Halim, Zurairah Berahim, Nurul A. Abdullah, Khairani I. Mokhtar, Kasmawati Mokhtar

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Endodontic furcal perforation remains both an endodontic and a periodontal problem. Regeneration of cementum is very essential for the perforation repair. The aim of this study was to investigate the role of Hertwig's epithelial root sheath (HERS) cells on the cementogenic differentiation of stem cells derived from human exfoliated deciduous teeth (SHED) in the presence of chitosan scaffold-TGFβ1. HERS cells were isolated and characterized then co-cultured with SHED with/without chitosan scaffold-TGFβ1. SHED proliferation was assessed by PrestoBlue. Alkaline phosphatase activity, mineralization behaviour and gene/protein expression of cemento/osteoblast phenotype of SHED were evaluated. Results of the present study showed that HERS cells in association with chitosan-TGFβ1 enhanced proliferation and cemento/osteogenic differentiation of SHED. Our novel co-culture system confirmed the potential effect of HERS cells to stimulate the differentiation of SHED along the cementoblastic lineage which was triggered in the presence of chitosan-TGFβ1. This approach possesses a novel therapeutic strategy for future endodontic perforation and periodontitis.

Keywords: cementogenesis, co-culture system, HERS, SHED

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Authors: Diobein Flores, Venus Buagas, Virgie Darunday

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The study inventoried the species composition of terrestrial ferns and lycopods in Center for Ecological Development and Recreation (CEDAR) Impalutao, Impasug-ong, Bukidnon. Specifically, it aimed to determine and describe the species composition, and diagnostic characters of the ferns and lycopods in the study site. Transect walk method was employed in the inventory of the species. Each species were classified, identified and described according to its diagnostic characters. Results of the study revealed a total of 20 species of ferns and lycopods. Of these, 18 species were ferns and 2 species were lycopods. Eleven (11) families and fifteen (15) genera for ferns and one (1) family and one (1) genera for lycopods. Psomiocarpa apifolia is Philippine endemic and said to be vulnerable or threatened. Taxonomic characters based on habit, rhizome, leaf arrangement and orientation, stem structure and circinate vernation were used to identify the terrestrial pteridophtyes into families, genera and species. The species collected and assessment in CEDAR should be further investigated and monitor their conservation status.

Keywords: alpha taxonomy, conservation, habit, taxonomic characters

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Authors: Meruert Serik, Nassipzhan Duisegaliyeva, Danara Tleumagambetova

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The article highlights and describes the characteristic features of real-time face detection in images and videos using machine learning algorithms. Students of educational programs reviewed the research work "6B01511-Computer Science", "7M01511-Computer Science", "7M01525- STEM Education," and "8D01511-Computer Science" of Eurasian National University named after L.N. Gumilyov. As a result, the advantages and disadvantages of Haar Cascade (Haar Cascade OpenCV), HoG SVM (Histogram of Oriented Gradients, Support Vector Machine), and MMOD CNN Dlib (Max-Margin Object Detection, convolutional neural network) detectors used for face detection were determined. Dlib is a general-purpose cross-platform software library written in the programming language C++. It includes detectors used for determining face detection. The Cascade OpenCV algorithm is efficient for fast face detection. The considered work forms the basis for the development of machine learning methods by future computer science teachers.

Keywords: algorithm, artificial intelligence, education, machine learning

Procedia PDF Downloads 75

Authors: M. Bagheri Varzaneh, H. R. Rahmani, R. Jahanian

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The present study aimed to investigate the effects of copper-methionine on ascites incidence and hematological, morphological and enzymatic responses in broiler chickens. A total of 480 one-day-old Ross 308 broiler chicks were used in a completely randomized design in a 2×3 factorial arrangement of treatments including two ambient temperatures (thermoneutral and cold stress) and three copper levels (0, 100, and 200 mg/kg as copper-methionine) with 4 replicates (20 birds in each replicate). Broilers were kept in an environmentally-controlled room from 1 to 28 days; then, half of them exposed to cold temperature from 28 to 45 days of age. The birds were sacrificed at days 38 and 45 of age. Heparinized blood samples were collected to measure hematocrit, hemoglobin concentration, red blood cell (RBC) count, alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Heart, lungs, liver, and spleen were collected and weighed separately on a sensitive digital scale. At d 38 of age, none of hematological variables, enzymatic parameters, and relative weights of organs were affected by treatments. Ascitic broilers were observed in group subjected to cold temperature and control diet (without supplemental copper) at d 45 of age. Relative weight of lungs and relative weight of heart in broilers fed on copper-methionine supplemented diets in cold temperature were lower compared with other groups. Relative liver weight, ALT, AST activities, and hematological parameters such as hematocrit, hemoglobin concentration, red blood cell count in ascitic broilers were significantly increased. In contrast, a significant decrease of the relative weight of spleen was shown in these chickens. The results showed that dietary supplementation with copper–methionine can decrease probability of ascites incidence in broilers chicks, especially under cold condition.

Keywords: ascites, cold temperature, copper-methionine, cold-stressed broiler

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Authors: Ekaterina Zubkova, Irina Beloglazova, Iurii Stafeev, Konsyantin Dergilev, Yelena Parfyonova, Mikhail Menshikov

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Mesenchymal stromal cells from adipose tissue (MSC) currently are widely used in regenerative medicine to restore the function of damaged tissues, but that is significantly hampered by their heterogeneity. One of the modern approaches to overcoming this obstacle is the polarization of cell subpopulations into a specific phenotype under the influence of cytokines and other factors that activate receptors and signal transmission to cells. We polarized MSC with factors affecting the inflammatory signaling and functional properties of cells, followed by verification of their expression profile and ability to affect the polarization of macrophages. RT-PCR evaluation showed that cells treated with LPS, interleukin-17, tumor necrosis factor α (TNF α), primarily express pro-inflammatory factors and cytokines, and after treatment with polyninosin polycytidic acid and interleukin-4 (IL4) anti-inflammatory factors and some proinflammatory factors. MSC polarized with pro-inflammatory cytokines showed a more robust pro-angiogenic effect in fibrin gel bead 3D angiogenesis assay. Further, we evaluated the possibility of paracrine effects of MSCs on the polarization of intact macrophages. Polarization efficiency was assesed by expression of M1/M2 phenotype markers CD80 and CD206. We showed that conditioned media from MSC preincubated in the presence of IL-4 cause an increase in CD206 expression similar to that observed in M2 macrophages. Conditioned media from MSC polarized in the presence of LPS or TNF-α increased the expression of CD80 antigen in macrophages, similar to that observed in M1 macrophages. In other cases, a pronounced paracrine effect of MSC on the polarization of macrophages was not detected. Thus, our study showed that the polarization of MSC along the pro-inflammatory or anti-inflammatory pathway allows us to obtain cell subpopulations that have a multidirectional modulating effect on the polarization of macrophages. (RFBR grants 20-015-00405 and 18-015-00398.)

Keywords: angiogenesis, cytokines, mesenchymal, polarization, inflammation

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Authors: Samira Bensoltane, Smina Ait Hamlet, Samti Meriem, Semmasel Asma

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Living organisms in the soil are subject to regular fluctuations of abiotic parameters, as well as a chemical contamination of the environment due to human activities. They are subject to multiple stressors they face. The aim of our work was to study the effects of insecticide: thiamethoxam (neonicotinoid), and the potential reversibility of the effects by an antioxidant: ginger on a bioindicator species in ecotoxicology, the land snail Helix aspersa. The effects were studied by a targeted cell approach of evaluating the effect of these molecules on tissue and cellular aspect of hepatopancreas through histological study. Treatment with thiamethoxam concentrations 10, 20, and 40 mg/l shows signs of inflammation even at low concentrations and from the 5th day of treatment. Histological examination of the hepatopancreas of snails treated with thiamethoxam showed significant changes from the lowest concentrations tested , note intertubular connective tissue enlargement, necrosis deferent types of cells (cells with calcium , digestive, excretory) , also damage acini, alteration of the apical membrane and lysis of the basement membrane in a dose- dependent manner. After 10 days of treatment and with 40 mg/l, the same changes were observed with a very advanced degeneration of the wall of the member that could be confused with the cell debris. For cons, the histological study of the hepatopancreas in Helix aspersa treated with ginger for a period of 15 days after stopping treatment with thiamethoxam has shown a partial regeneration of hepatopancreatic tissue snails treated with all concentrations of thiamethoxam and especially in the intertubular connective tissue of the wall and hepatopancreatic digestive tubules. Finally, we can conclude that monitoring the effect of the insecticide thiamethoxam showed significant alterations, however, treatment with ginger shows regeneration of damaged cells themselves much sharper at low concentration (10 mg/L).

Keywords: Helix aspersa, insecticides, thiamethoxam, ginger, hepatopancreas

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Authors: András Fülöp, Lejla Heilmann, Zsolt Szabó, Ákos Koós

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Microbial fuel cells (MFCs) present a sustainable biotechnological solution to future energy demands. The aim of this study was to construct soil based, single cell, membrane-less MFC systems, operated without treatment to continuously power on-site monitoring and control systems during the soil bioremediation processes. Our Pseudomonas aeruginosa 541 isolate is an ideal choice for MFCs, because it is able to produce pyocyanin which behaves as electron-shuttle molecule, furthermore, it also has a significant antimicrobial effect. We tested several materials and structural configurations to obtain long term high power output. Comparing different configurations, a proton exchange membrane-less, 0.6 m long with 0.05 m diameter MFC tubes offered the best long-term performances. The long-term electricity production were tested from starch, yeast extract (YE), carboxymethyl cellulose (CMC) with humic acid (HA) as a mediator. In all cases, 3 kΩ external load have been used. The two best-operated systems were the Pseudomonas aeruginosa 541 containing MFCs with 1 % carboxymethyl cellulose and the MFCs with 1% yeast extract in the anode area and 35% hydrogel in the cathode chamber. The first had 3.3 ± 0.033 mW/m2 and the second had 4.1 ± 0.065 mW/m2 power density values. These systems have operated for 230 days without any treatment. The addition of 0.2 % HA and 1 % YE referred to the volume of the anode area resulted in 1.4 ± 0.035 mW/m2 power densities. The mixture of 1% starch with 0.2 % HA gave 1.82 ± 0.031 mW/m2. Using CMC as retard carbon source takes effect in the long-term bacterial survivor, thus enable the expression of the long term power output. The application of hydrogels in the cathode chamber significantly increased the performance of the MFC units due to their good water retention capacity.

Keywords: microbial fuel cell, bioremediation, Pseudomonas aeruginosa, biotechnological solution

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Authors: Yu-Hsuan Chang, Jian-Hao Su, Chen-Yu Chen, Wei-Mon Yan

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In this work, the experimental measurement was applied to examine the membrane type and flow field design on the performance of a planar membrane humidifier. The performance indexes were used to evaluate the planar membrane humidifier. The performance indexes of the membrane humidifier include the dew point approach temperature (DPAT), water recovery ratio (WRR), water flux (J) and pressure loss (P). The experiments contain mainly three parts. In the first part, a single membrane humidifier was tested using different flow field under different dry-inlet temperatures. The measured results show that the dew point approach temperature decreases with increasing the depth of flow channel at the same width of flow channel. However, the WRR and J reduce with an increase in the dry air-inlet temperature. The pressure loss tests indicate that pressure loss decreases with increasing the hydraulic diameter of flow channel, resulting from an increase in Darcy friction. Owing to the comparison of humidifier performances and pressure losses, the flow channel of width W=1 and height H=1.5 was selected as the channel design of the multi-membrane humidifier in the second part of experiment. In the second part, the multi-membrane humidifier was used to evaluate the humidification performance under different relative humidity and flow rates. The measurement results indicate that the humidifier at both lower temperature and relative humidity of inlet dry air have higher DPAT but lower J and WRR. In addition, the counter flow approach has better mass and heat transfer performance than the parallel flow approach. Moreover, the effects of dry air temperature, relative humidity and humidification approach are not significant to the pressure loss in the planar membrane humidifier. For the third part, different membranes were tested in this work in order to find out which kind membrane is appropriate for humidifier.

Keywords: water management, planar membrane humidifier, heat and mass transfer, pressure loss, PEM fuel cell

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Authors: Concetta Busacca, Leone Frusteri, Orazio Di Blasi, Alessandra Di Blasi

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The large-scale extension of renewable energy led, recently, to the development of efficient and low-cost electrochemical energy storage (EES) systems such as batteries. Although lithium-ion battery (LIB) technology is relatively mature, several issues regarding safety, cyclability, and high costs must be overcome. Thanks to the availability and low cost of sodium, sodium-ion batteries (NIB) have the potential to meet the energy storage needs of the large-scale grid, becoming a valid alternative to LIB in some energy sectors, such as the stationary one. However, important challenges such as low specific energy and short cyclic life due to the large radius of Na+ must be faced to introduce this technology into the market. As an important component of SIBs, cathode materials have a significant effect on the electrochemical performance of SIBs. Recently, sodium layer transition metal oxides, phosphates, and organic compounds have been investigated as cathode materials for SIBs. In particular, phosphate-based compounds such as NaₓMPO₄ (M= Fe, Co, Mn) have been extensively studied as cathodic polyanion materials due to their long cycle stability and appropriate operating voltage. Among these, an interesting cathode material is the NaMnPO₄ based one, thanks to the stability and the high redox potential of the Mn²⁺/Mn³⁺ ion pair (3÷4 V vs. Na+/Na), which allows reaching a high energy density. This work concerns with the synthesis of a composite material based on NaMnPO₄ and carbon nanofibers (NaMnPO₄-CNF) characterized by a mixed crystalline structure between the maricite and olivine phases and a self-standing manufacture obtained by electrospinning technique. The material was tested in a Na-ion battery coin cell in half cell configuration, and showed outstanding electrocatalytic performances with a specific discharge capacity of 125 mAhg⁻¹ and 101 mAhg⁻¹ at 0.3C and 0.6C, respectively, and a retention capacity of about 80% a 0.6C after 100 cycles.

Keywords: electrospinning, self standing materials, Na ion battery, cathode materials

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Authors: Florian Billing, Soren Segan, Meike Jakobi, Elsa Arefaine, Aliki Jerch, Xin Xiong, Matthias Becker, Thomas Joos, Burkhard Schlosshauer, Ulrich Rothbauer, Nicole Schneiderhan-Marra, Hanna Hartmann, Christopher Shipp

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The immune response plays a major role in implant biocompatibility, but an understanding of how to design biomaterials for specific immune responses is yet to be achieved. We aimed to better understand how changing certain material properties can drive immune responses. To this end, we tested immune response to experimental implant coatings that vary in specific characteristics. A layer-by-layer approach was employed to vary surface charge and wettability. Human-based in vitro models (THP-1 macrophages and primary peripheral blood mononuclear cells (PBMCS)) were used to assess immune responses using multiplex cytokine analysis, flow cytometry (CD molecule expression) and microscopy (cell morphology). We observed dramatic differences in immune response due to specific alterations in coating properties. For example altering the surface charge of coating A from anionic to cationic resulted in the substantial elevation of the pro-inflammatory molecules IL-1beta, IL-6, TNF-alpha and MIP-1beta, while the pro-wound healing factor VEGF was significantly down-regulated. We also observed changes in cell surface marker expression in relation to altered coating properties, such as CD16 on NK Cells and HLA-DR on monocytes. We furthermore observed changes in the morphology of THP-1 macrophages following cultivation on different coatings. A correlation between these morphological changes and the cytokine expression profile is ongoing. Targeted changes in biomaterial properties can produce vast differences in immune response. The properties of the coatings examined here may, therefore, be a method to direct specific biological responses in order to improve implant biocompatibility.

Keywords: biomaterials, coatings, immune system, implants

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Authors: Cigdem Gul, Murat Tosunoglu, Nurcihan Hacioglu

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The contamination or desiccation of fresh waters also has a negative effect on freshwater turtles like other fresh water-dependent species. In order to conserve those species, which are confronted with such negative conditions, it is necessary to know beforehand the biology and the physiology of species. In this study, a comprehensive health assessment was conducted on a total of 20 clinically normal individuals free living Western Caspian Turtle (Mauremys rivulata) captured from two different freshwater localities in the Biga stream (Çanakkale-Turkey). When comparing our findings with the Turkish legislation (Water pollution control regulation), the 1. Locality of the Biga stream in terms of total coliform classified as "high quality water" (Coliform: 866.66 MPN/100 mL), while the 2. Locality was a “contaminated water" (Coliform: 53266.66 MPN/100 mL). Blood samples for hematological and biochemical analyses were obtained from the dorsal coccygeal vein. A total of 1-2 mL of blood was collected from each of the specimens via needle. After the required procedures had been performed, the turtles were put back in the same localities. Hematological and biochemical analyses based on high quality water and contaminated water, respectively, are as follows: Red blood cell count (512600-582666.66 per cubic millimeter of blood), white blood cell count (5920-5980 per cubic millimeter of blood), hematocrit value (24-24.66 %), hemoglobin concentration (6.52-6.35 g/dl), mean corpuscular volume (466.20-468.98 fl), mean corpuscular hemoglobin (125.77-113.84 pg), mean corpuscular hemoglobin concentration (28.25-26.49 %), glucose (94.43-87.43 mg/dl), creatinine (0.23-0.3241 mg/dl), uric acid (12.59-10.48 mg/L), albumin (1.46-1.25 g/dl), calcium (8.67-9.59 mg/dl), triglyceride (95.55-75.21 mg/dl), and total protein (4.85-3.45 g/dl). When an examination was made depending on the water quality of freshwater, variations were detected in hematology and biochemistry values, but not found significant difference.

Keywords: biochemistry, freshwater quality, hematological parameters, Mauremys rivulata.

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Authors: Mahdieh Farzin Asanjan, Erkan Unal Mumcuoglu

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Mitochondria are cytoplasmic organelles of the cell, which have a significant role in the variety of cellular metabolic functions. Mitochondria act as the power plants of the cell and are surrounded by two membranes. Significant morphological alterations are often due to changes in mitochondrial functions. A powerful technique in order to study the three-dimensional (3D) structure of mitochondria and its alterations in disease states is Electron microscope tomography. Detection of mitochondria in electron microscopy images due to the presence of various subcellular structures and imaging artifacts is a challenging problem. Another challenge is that each image typically contains more than one mitochondrion. Hand segmentation of mitochondria is tedious and time-consuming and also special knowledge about the mitochondria is needed. Fully automatic segmentation methods lead to over-segmentation and mitochondria are not segmented properly. Therefore, semi-automatic segmentation methods with minimum manual effort are required to edit the results of fully automatic segmentation methods. Here two editing tools were implemented by applying spline surface dragging and interactive live-wire segmentation tools. These editing tools were applied separately to the results of fully automatic segmentation. 3D extension of these tools was also studied and tested. Dice coefficients of 2D and 3D for surface dragging using splines were 0.93 and 0.92. This metric for 2D and 3D for live-wire method were 0.94 and 0.91 respectively. The root mean square symmetric surface distance values of 2D and 3D for surface dragging was measured as 0.69, 0.93. The same metrics for live-wire tool were 0.60 and 2.11. Comparing the results of these editing tools with the results of automatic segmentation method, it shows that these editing tools, led to better results and these results were more similar to ground truth image but the required time was higher than hand-segmentation time

Keywords: medical image segmentation, semi-automatic methods, transmission electron microscopy, surface dragging using splines, live-wire

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Authors: Eric Kumar, Erica Cochran, Zhiang Zhang, Wei Liang, Ronak Mody

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The objective of this article was to create a modelling framework that exposes the marginal costs of shifting workloads across geographically distributed data-centers. Geographical distribution of internet services helps to optimize their performance for localized end users with lowered communications times and increased availability. However, due to the geographical and temporal effects, the physical embodiments of a service's data center infrastructure can vary greatly. In this work, we first identify that the sources of variances in the physical infrastructure primarily stem from local weather conditions, specific user traffic profiles, energy sources, and the types of IT hardware available at the time of deployment. Second, we create a traffic simulator that indicates the IT load at each data-center in the set as an approximator for user traffic profiles. Third, we implement a framework that quantifies the global level energy demands using building energy models and the traffic profiles. The results of the model provide a time series of energy demands that can be used for further life cycle analysis of internet services.

Keywords: data-centers, energy, life cycle, network simulation

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Authors: Fitsumbrhan Tajebe, Fadil Murad, Mitikie Tigabie, Mareye Abebaw, Tadele Alemu, Sefanit Abate, Rezika Mohammedw, Arega Yeshanew, Elias Shiferaw

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Background: Visceral leshimaniasis is a parasitic disease characterized by a systemic infection of phagocytic cells. Hematological parameters of these patients may be affected by the progress of the disease or treatment. Thus, the current study aimed to assess the hematological profiles of visceral leishmaniasis patients before and after treatment. Method: An institutional based retrospective cohort study was conducted among visceral leishmaniasis patients at University of Gondar Comprehensive Specialized Referral Hospital Leishmaniasis Research and Treatment Center from 2013 to 2018. Hematological profiles before initiation and after completion of treatment were extracted from registration book. Descriptive statics was presented using frequency and percentage. Paired t-test and Wilcoxon Signed rank test were used for comparing mean difference for normally and non- normally distributed data, respectively. Spearman and Pearson correlation analysis was used to describe the correlation of hematological parameters with different variables. P value < 0.05 was considered as statistically significant. Result: Except absolute nerutrophil count, post treatment hematological parameters show a significant increment compared to pretreatment one. The prevalence of anemia, leucopenia and thrombocytopenia was 85.5%, 83.4% and 75.8% prior to treatment and it was 58.3%, 38.2% and 19.2% after treatment, respectively. Moreover, parasite load of the disease showed statistically significant negative correlation with hematological profiles mainly with white blood cell and red blood cell. Conclusion: Majority of hematological profiles of patients with active VL have been restored after treatment, which might be associated with treatment effect on parasite proliferation and concentration of parasite in visceral organ, which directly affect hematological profiles.

Keywords: visceral leshimaniasis, hematological profile, anti-leshimanial drug, Gondar

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Authors: Sneha Kumari, Ravi Krishnan Elangovan

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This abstract describes the development of a high-speed tracking method by modification in motor components for nanoparticle attachment. Myosin motors are nano-sized protein machines powering movement that defines life. These miniature molecular devices serve as engines utilizing chemical energy stored in ATP to produce useful mechanical energy in the form of a few nanometre displacement events leading to force generation that is required for cargo transport, cell division, cell locomotion, translated to macroscopic movements like running etc. With the advent of in vitro motility assay (IVMA), detailed functional studies of the actomyosin system could be performed. The major challenge with the currently available IVMA for tracking actin filaments is a resolution limitation of ± 50nm. To overcome this, we are trying to develop Single Molecule IVMA in which nanoparticle (GNP/QD) will be attached along or on the barbed end of actin filaments using CapZ protein and visualization by a compact TIRF module called ‘cTIRF’. The waveguide-based illumination by cTIRF offers a unique separation of excitation and collection optics, enabling imaging by scattering without emission filters. So, this technology is well equipped to perform tracking with high precision in temporal resolution of 2ms with significantly improved SNR by 100-fold as compared to conventional TIRF. Also, the nanoparticles (QD/GNP) attached to actin filament act as a point source of light coffering ease in filament tracking compared to conventional manual tracking. Moreover, the attachment of cargo (QD/GNP) to the thin filament paves the way for various nano-technological applications through their transportation to different predetermined locations on the chip

Keywords: actin, cargo, IVMA, myosin motors and single-molecule system

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Authors: Beenish Saba, Ann D. Christy

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Modern day municipal solid waste landfills are operated and controlled to protect the environment from contaminants during the biological stabilization and degradation of the solid waste. They are equipped with liners, caps, gas and leachate collection systems. Landfill gas is passively or actively collected and can be used as bio fuel after necessary purification, but leachate treatment is the more difficult challenge. Leachate, if not recirculated in a bioreactor landfill system, is typically transported to a local wastewater treatment plant for treatment. These plants are designed for sewage treatment, and often charge additional fees for higher strength wastewaters such as leachate if they accept them at all. Different biological, chemical, physical and integrated techniques can be used to treat the leachate. Treating that leachate with simultaneous power production using microbial fuel cells (MFC) technology has been a recent innovation, reported its application in its earliest starting phase. High chemical oxygen demand (COD), ionic strength and salt concentration are some of the characteristics which make leachate an excellent substrate for power production in MFCs. Different materials of electrodes, microbial communities, carbon co-substrates and temperature conditions are some factors that can be optimized to achieve simultaneous power production and treatment. The advantage of the MFC is its dual functionality but lower power production and high costs are the hurdles in its commercialization and more widespread application. The studies so far suggest that landfill leachate MFCs can produce 1.8 mW/m2 with 79% COD removal, while amendment with food leachate or domestic wastewater can increase performance up to 18W/m3 with 90% COD removal. The columbic efficiency is reported to vary between 2-60%. However efforts towards biofilm optimization, efficient electron transport system studies and use of genetic tools can increase the efficiency of the MFC and can determine its future potential in treating landfill leachate.

Keywords: microbial fuel cell, landfill leachate, power generation, MFC

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Authors: Carlos Amnael Orozco-Diaz, Robert David Moorehead, Gwendolen Reilly, Fiona Gilchrist, Cheryl Ann Miller

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The current gold-standard for maxillofacial reconstruction surgery (MRS) utilizes auto-grafted cancellous bone as a filler. This study was aimed towards developing a polylactic-acid/hydroxyapatite (PLA-HA) composite suitable for fused-deposition 3D printing. Functionalization of the polymer through the addition of HA was directed to promoting bone-regeneration properties so that the material can rival the performance of cancellous bone grafts in terms of bone-lesion repair. This kind of composite enables the production of MRS implants based off 3D-reconstructions from image studies – namely computed tomography – for anatomically-correct fitting. The present study encompassed in-vitro degradation and in-vitro biocompatibility profiling for 3D-printed PLA and PLA-HA composites. PLA filament (Verbatim Co.) and Captal S hydroxyapatite micro-scale HA powder (Plasma Biotal Ltd) were used to produce PLA-HA composites at 5, 10, and 20%-by-weight HA concentration. These were extruded into 3D-printing filament, and processed in a BFB-3000 3D-Printer (3D Systems Co.) into tensile specimens, and were mechanically challenged as per ASTM D638-03. Furthermore, tensile specimens were subjected to accelerated degradation in phosphate-buffered saline solution at 70°C for 23 days, as per ISO-10993-13-2010. This included monitoring of mass loss (through dry-weighing), crystallinity (through thermogravimetric analysis/differential thermal analysis), molecular weight (through gel-permeation chromatography), and tensile strength. In-vitro biocompatibility analysis included cell-viability and extracellular matrix deposition, which were performed both on flat surfaces and on 3D-constructs – both produced through 3D-printing. Discs of 1 cm in diameter and cubic 3D-meshes of 1 cm3 were 3D printed in PLA and PLA-HA composites (n = 6). The samples were seeded with 5000 MG-63 osteosarcoma-like cells, with cell viability extrapolated throughout 21 days via resazurin reduction assays. As evidence of osteogenicity, collagen and calcium deposition were indirectly estimated through Sirius Red staining and Alizarin Red staining respectively. Results have shown that 3D printed PLA loses structural integrity as early as the first day of accelerated degradation, which was significantly faster than the literature suggests. This was reflected in the loss of tensile strength down to untestable brittleness. During degradation, mass loss, molecular weight, and crystallinity behaved similarly to results found in similar studies for PLA. All composite versions and pure PLA were found to perform equivalent to tissue-culture plastic (TCP) in supporting the seeded-cell population. Significant differences (p = 0.05) were found on collagen deposition for higher HA concentrations, with composite samples performing better than pure PLA and TCP. Additionally, per-cell-calcium deposition on the 3D-meshes was significantly lower when comparing 3D-meshes to discs of the same material (p = 0.05). These results support the idea that 3D-printable PLA-HA composites are a viable resorbable material for artificial grafts for bone-regeneration. Degradation data suggests that 3D-printing of these materials – as opposed to other manufacturing methods – might result in faster resorption than currently-used PLA implants.

Keywords: bone regeneration implants, 3D-printing, in vitro testing, biocompatibility, polymer degradation, polymer-ceramic composites

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Authors: Esther N. Maina, Anna Skowronska, Sridhar Chaganti, Malcolm A. Taylor, Paul G. Murray, Tatjana Stankovic

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Epstein-Barr virus (EBV) has been implicated in the pathogenesis of human tumours of B-cell origin. The demonstration that a proportion of Hodgkin lymphomas and all Burkitt’s lymphomas harbour EBV suggests that the virus contributes to the development of these malignancies. However, the mechanisms of lymphomagenesis remain largely unknown. To determine whether EBV causes DNA damage and alters DNA damage response in cells of EBV-driven lymphoma origin, Germinal Centre (GC) B cells were infected with EBV and DNA damage responses to gamma ionising radiation (IR) assessed at early time points (12hr – 72hr) after infection and prior to establishment of lymphoblastoid (LCL) cell lines. In the presence of EBV, we observed induction of spontaneous DNA DSBs and downregulation of ATM-dependent phosphorylation in response to IR. This downregulation coincided with reduced ability of infected cells to repair IR-induced DNA double-strand breaks, as measured by the kinetics of gamma H2AX, a marker of double-strand breaks, and by the tail moment of the comet assay. Furthermore, we found that alteration of DNA damage responses coincided with the expression of LMP-1 protein. The presence of the EBV virus did not affect the localization of the ATM-dependent DNA repair proteins to sites of damage but instead lead to an increased expression of PP5, a phosphatase that regulates ATM function. The impact of the virus on DNA repair was most prominent 24h after infection, suggesting that this time point is crucial for the viral establishment in B cells. Our results suggest that during an early infection EBV virus dampens crucial cellular responses to DNA double-strand breaks which facilitate successful viral infection, but at the same time might provide the mechanism for tumor development.

Keywords: EBV, ATM, DNA damage, germinal center cells

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Authors: Checkfaith I. Aizebeoje, Temitope O. Lawal, Bolanle A. Adeniyi

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The overuse and abuse of antibiotics in treating zoonotic infections in humans and opportunistic infections in rabbit has contributed to the increase in antimicrobial drug resistance, therefore, an alternative to antibiotics is needed in treating these infections. The study was carried out to determine the antimicrobial activity of lactic acid bacteria (LAB) isolated from rabbit’s faeces against multidrug-resistant (MDR) pathogens isolated from the same rabbit. Twelve faecal samples and twelve swabs from fur samples were randomly collected aseptically from apparently healthy rabbits from Ajibode, Ibadan and University of Ibadan research farm in Ibadan, Oyo state, Nigeria. Lactic acid bacteria and multidrug-resistant pathogens were isolated using appropriate agar media and identified by partial sequencing of the 16SrRNA gene. Antibiotic susceptibility pattern of isolated bacteria and LAB were determined by the agar diffusion method. The antibacterial activity of the LAB against the test pathogens was determined using the agar overlay and agar diffusion methods. The pathogens Myroides gitamensis, Citrobacter rodentium, Acinetobacter johnsonii, Enterobacter oryzendophyticus and Serratia marcescens as well as twenty-eight (28) species of LAB belonging to Acetobacter and Lactobacillus genera were identified and characterized. Lactobacillus plantarum had the highest (60.71%) occurrence of the LAB. Viable cells and cell free supernatant (CFS) of isolated LAB inhibited the growth of the test organisms with the largest zone of inhibition (40 mm) produced by Lactobacillus plantarum against Citrobacter rodentium. This study showed that LAB from rabbit possess considerable antibacterial activity against multidrug-resistant bacteria from the same environment.

Keywords: antibacterial activities, cell-free supernatant, lactic acid bacteria; multidrug-resistant pathogens, rabbits’ faeces

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