Search results for: sustain release

Authors: Hani M. M. Alothaid, Louise Robson, Richmond Muimo

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This study will investigate cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA) dependent calcineurin (Cn), known as protein phosphatase 2 B (PP2B) as well, regulation of chloride ion (Cl⁻) secretion and the release of pro-inflammatory molecules in immune cells such as cytokines. THP-1-derived monocytes, primary human monocytes and the bronchial epithelial cell line (16HBE14o-) were used in this study. The 16HBE14o- cells were chosen as positive control. Hence, to further confirm the expression of cystic fibrosis transmembrane conductance regulator (CFTR), calcium binding protein (S100A10), annexin A2 (AnxA2) and calcineurin A subunit (CnA) in all three cell types, cell lysate was probed against corresponding primary antibodies by immunoblotting. Western blot analyses show the expression of CFTR, AnxA2, CnA and S100A10 in THP-1-derived monocytes and primary human monocytes. In conclusion, CFTR, S100A10, CnA and AnxA2 are expressed in THP-1-derived monocytes and primary human monocytes and regulate Cl⁻ secretion. Also, they may play a role in the pro-inflammatory molecules release. The ongoing work will confirm interaction between these proteins in the cell lines.

Keywords: annexin A2, calcineurin, CFTR, chloride, monocytes, pro-inflammatory molecules, S100A10

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Authors: Indu Verma, Santanu Kumar Pal

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Interactions between DNA and adsorbed Poly (L-lysine) (PLL) on liquid crystal (LC) droplets were investigated using polarizing optical microcopy (POM) and epi-fluorescence microscopy. Earlier, we demonstrated that adsorption of PLL to the LC/aqueous interface resulted in homeotropic orientation of the LC and thus exhibited a radial configuration of the LC confined within the droplets. Subsequent adsorption of DNA (single stranded DNA/double stranded DNA) at PLL coated LC droplets was found to trigger a LC reorientation within the droplets leading to pre-radial/bipolar configuration of those droplets. To our surprise, subsequent exposure of complementary ssDNA (c-ssDNA) to ssDNA/ adsorbed PLL modified LC droplets did not cause the LC reorientation. This is likely due to the formation of polyplexes (DNA-PLL complex) as confirmed by fluorescence microscopy and atomic force microscopy. In addition, dsDNA adsorbed PLL droplets have been found to be effectively used to displace (controlled release) propidium iodide (a model drug) encapsulated within dsDNA over time. These observations suggest the potential for a label free droplet based LC detection system that can respond to DNA and may provide a simple method to develop DNA-based drug nano-carriers.

Keywords: DNA biosensor, drug delivery, interfaces, liquid crystal droplets

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Authors: Bao-Fang Wen, Meng-Na Dai, Gao-Pei Zhu, Chen-Xi Zhang, Jing Sun, Xun-Bao Yin, Yu-Han Zhao, Hong-Wei Sun, Wei-Fen Zhang

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A drug-loaded nanoparticles containing berberine hydrochloride (BH/FA-CTS-NPs) was prepared. The physicochemical characterizations of BH/FA-CTS-NPs and the inhibitory effect on the HeLa cells were investigated. Folic acid-conjugated chitosan (FA-CTS) was prepared by amino reaction of folic acid active ester and chitosan molecules; BH/FA-CTS-NPs were prepared using ionic cross-linking technique with BH as a model drug. The morphology and particle size were determined by Transmission Electron Microscope (TEM). The average diameters and polydispersity index (PDI) were evaluated by Dynamic Light Scattering (DLS). The interaction between various components and the nanocomplex were characterized by Fourier Transform Infrared Spectroscopy (FT-IR). The entrapment efficiency (EE), drug-loading (DL) and in vitro release were studied by UV spectrophotometer. The effect of cell anti-migratory and anti-invasive actions of BH/FA-CTS-NPs were investigated using MTT assays, wound healing assays, Annexin-V-FITC single staining assays, and flow cytometry, respectively. HeLa nude mice subcutaneously transplanted tumor model was established and treated with different drugs to observe the effect of BH/FA-CTS-NPs in vivo on HeLa bearing tumor. The BH/FA-CTS-NPs prepared in this experiment have a regular shape, uniform particle size, and no aggregation phenomenon. The results of DLS showed that mean particle size, PDI and Zeta potential of BH/FA-CTS NPs were (249.2 ± 3.6) nm, 0.129 ± 0.09, 33.6 ± 2.09, respectively, and the average diameter and PDI were stable in 90 days. The results of FT-IR demonstrated that the characteristic peaks of FA-CTS and BH/FA-CTS-NPs confirmed that FA-CTS cross-linked successfully and BH was encapsulated in NPs. The EE and DL amount were (79.3 ± 3.12) % and (7.24 ± 1.41) %, respectively. The results of in vitro release study indicated that the cumulative release of BH/FA-CTS NPs was (89.48±2.81) % in phosphate-buffered saline (PBS, pH 7.4) within 48h; these results by MTT assays and wund healing assays indicated that BH/FA-CTS NPs not only inhibited the proliferation of HeLa cells in a concentration and time-dependent manner but can induce apoptosis as well. The subcutaneous xenograft tumor formation rate of human cervical cancer cell line HeLa in nude mice was 98% after inoculation for 2 weeks. Compared with BH group and BH/CTS-NPs group, the xenograft tumor growth of BH/FA-CTS-NPs group was obviously slower; the result indicated that BH/FA-CTS-NPs could significantly inhibit the growth of HeLa xenograft tumor. BH/FA-CTS NPs with the sustained release effect could be prepared successfully by the ionic crosslinking method. Considering these properties, block proliferation and impairing the migration of the HeLa cell line, BH/FA-CTS NPs could be an important compound for consideration in the treatment of cervical cancer.

Keywords: folic-acid, chitosan, berberine hydrochloride, nanoparticles, cervical cancer

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Authors: Mohammad H. Ruhipour, Mahdi Goharrokhi, Mahsa Ghasemi, Artadokht Ostadsarayi

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In this paper, we are aiming to study the consequences of chlorine gas leak in direct chlorine gas injection compared to using bleach (sodium hypochlorite), studying the negative effects both on the environment and individuals. This study was performed in the cooling towers of a natural fractioning unit of Bandar-e-IMAM petrochemical plant. Considering that chlorine gas is highly toxic and based on the health regulation, its release into the surrounding environment can be very dangerous for people and even fatal for individuals. We studied performing quantitative studies in the worst cases of event incidence. In addition, studying alternative methods with a lower risk was also on the agenda to select the least likely possible option causing an accident. In this paper chlorine gas release consequences have been evaluated by using PHAST software. Reaching to 10 ppm of chlorine gas concentration was basis of hazardous area determination. The results show that the full chlorine gas line rupture scenario in Pasquill category F, were worst case, and many people could be harmed around cooling towers area because of chlorine gas inhalation.

Keywords: chlorine gas, consequence modeling, cooling towers, direct chlorination, risk assessment, system failure

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Authors: Nagasamy Venkatesh Dhandapani, Amged Awad El-Gied

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Cefixime, a BCS class II drug, is insoluble in water but freely soluble in acetone and in alcohol. The aqueous solubility of cefixime in water is poor and exhibits exceptionally slow and intrinsic dissolution rate. In the present study, cefixime and β-Cyclodextrin (β-CD) solid dispersions were prepared with a view to study the effect and influence of β-CD on the solubility and dissolution rate of this poorly aqueous soluble drug. Phase solubility profile revealed that the solubility of cefixime was increased in the presence of β-CD and was classified as A_L-type. Effect of variable, such as drug:carrier ratio, was studied. Physical characterization of the solid dispersion was characterized by Fourier transform infrared spectroscopy (FT-IR) and Differential scanning calorimetry (DSC). These studies revealed that a distinct loss of drug crystallinity in the solid molecular dispersions is ostensibly accounting for enhancement of dissolution rate in distilled water. The drug release from the prepared solid dispersion exhibited a first order kinetics. Solid dispersions of cefixime showed a 6.77 times fold increase in dissolution rate over the pure drug.

Keywords: β-cyclodextrin, cefixime, dissolution, Kneading method, solid dispersions, release kinetics

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Authors: Sutapa Mondal Roy, Suban K. Sahoo

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The primary aim of this work is to synthesis silver nanoparticles (AgNPs) through environmentally benign routes to avoid any chemical toxicity related undesired side effects. The nanoparticles were stabilized with drug ciprofloxacin (Cp) and were studied for their effectiveness as drug delivery agent. Targeted drug delivery improves the therapeutic potential of drugs at the diseased site as well as lowers the overall dose and undesired side effects. The small size of nanoparticles greatly facilitates the transport of active agents (drugs) across biological membranes and allows them to pass through the smallest capillaries in the body that are 5-6 μm in diameter, and can minimize possible undesired side effects. AgNPs are non-toxic, inert, stable, and has a high binding capacity and thus can be considered as biomaterials. AgNPs were synthesized from the nutrient broth supernatant after the culture of environment-friendly bacteria Bacillus subtilis. The AgNPs were found to show the surface plasmon resonance (SPR) band at 425 nm. The Cp capped Ag nanoparticles formation was complete within 30 minutes, which was confirmed from absorbance spectroscopy. Physico-chemical nature of the AgNPs-Cp system was confirmed by Dynamic Light Scattering (DLS), Transmission Electron Microscopy (TEM) etc. The AgNPs-Cp system size was found to be in the range of 30-40 nm. To monitor the kinetics of drug release from the surface of nanoparticles, the release of Cp was carried out by careful dialysis keeping AgNPs-Cp system inside the dialysis bag at pH 7.4 over time. The drug release was almost complete after 30 hrs. During the drug delivery process, to understand the AgNPs-Cp system in a better way, the sincere theoretical investigation is been performed employing Density Functional Theory. Electronic charge transfer, electron density, binding energy as well as thermodynamic properties like enthalpy, entropy, Gibbs free energy etc. has been predicted. The electronic and thermodynamic properties, governed by the AgNPs-Cp interactions, indicate that the formation of AgNPs-Cp system is exothermic i.e. thermodynamically favorable process. The binding energy and charge transfer analysis implies the optimum stability of the AgNPs-Cp system. Thus, the synthesized Cp-Ag nanoparticles can be effectively used for biological purposes due to its environmentally benign routes of synthesis procedures, which is clean, biocompatible, non-toxic, safe, cost-effective, sustainable and eco-friendly. The Cp-AgNPs as biomaterials can be successfully used for drug delivery procedures due to slow release of drug from nanoparticles over a considerable period of time. The kinetics of the drug release show that this drug-nanoparticle assembly can be effectively used as potential tools for therapeutic applications. The ease of synthetic procedure, lack of possible chemical toxicity and their biological activity along with excellent application as drug delivery agent will open up vista of using nanoparticles as effective and successful drug delivery agent to be used in modern days.

Keywords: silver nanoparticles, ciprofloxacin, density functional theory, drug delivery

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Authors: Subrata Kar, Banani Kundu, Papiya Nandy, Ruma Basu, Sukhen Das

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Natural montmorilollite clay is a common ingredient in pharmaceutical products, both as excipients and active support; hence considered as suitable candidate for Drug Delivery System. In this work, cationic detergent CTAB is used to increase the interlayer spacing of Na+-Montmoriollite clay to intercalate curcumin and methotrexate. Methotrexate is a folic acid antagonist, anti-proliferative and immunosuppressive agent; while curcumin is a bioactive constituent of rhizomes of Curcuma longa, possessing remarkable chemo-preventive and anti-inflammatory properties. The resultant inorganic-organic hybrids are characterized by X-ray diffraction (XRD), Infrared spectroscopy (FTIR) and Thermo Gravimetric Analysis (TGA) to confirm successful intercalation of curcumin and Methotrexate within clay layers. Pharmaceutical investigation of the hybrids is explored by studying the drug loading (%), encapsulation efficiency and release kinetics. Finally in-vitro studies are performed using cancer cells to find the effect of released curcumin to improve the sensitivity of clay bound methotrexate to ameliorate cell death compared to their effectiveness when used without the inorganic aluminosilicate vehicle.

Keywords: montmorillonite, methotrexate, curcumin, loading efficiency, release kinetics, anticancer activity

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Authors: Sunil K. Jena, Sanjaya K. Samal, Mahesh Chand, Abhay T. Sangamwar

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Tamoxifen (TMX) and its analogues are approved as a first line therapy for the treatment of estrogen receptor-positive tumors. However, clinical development of TMX has been hampered by its low bioavailability and severe hepatotoxicity. Herein, we attempt to design a new drug delivery vehicle that could enhance the pharmacokinetic performance of TMX. Initially, high-molecular weight carboxymethyl chitosan was hydrolyzed to low-molecular weight carboxymethyl chitosan (LMW CMC) with hydrogen peroxide under the catalysis of phosphotungstic acid. Amphiphilic block copolymers of LMW CMC were synthesized via amidation reaction between the carboxyl group of α-tocopherol succinate (TS) and an amine group of LMW CMC. These amphiphilic block copolymers were self-assembled to nanosize core-shell-structural micelles in the aqueous medium. The critical micelle concentration (CMC) decreased with the increasing substitution of TS on LMW CMC, which ranged from 1.58 × 10-6 to 7.94 × 10-8 g/mL. Maximum TMX loading up to 8.08 ± 0.98% was achieved with Cmc-TS4.5 (TMX/Cmc-TS4.5 with 1:8 weight ratio). Both blank and TMX-loaded polymeric micelles (TMX-PM) of Cmc-TS4.5 exhibits spherical shape with the particle size below 200 nm. TMX-PM has been found to be stable in the gastrointestinal conditions and released only 44.5% of the total drug content by the first 72 h in simulated gastric fluid (SGF), pH 1.2. However, the presence of pepsin does not significantly increased the TMX release in SGF, pH 1.2, released only about 46.2% by the first 72 h suggesting its inability to cleave the peptide bond. In contrast, the release of TMX from TMX-PM4.5 in SIF, pH 6.8 (without pancreatin) was slow and sustained, released only about 10.43% of the total drug content within the first 30 min and nearly about 12.41% by the first 72 h. The presence of pancreatin in SIF, pH 6.8 led to an improvement in drug release. About 28.09% of incorporated TMX was released in the presence of pancreatin in 72 h. A cytotoxicity study demonstrated that TMX-PM exhibited time-delayed cytotoxicity in human MCF-7 breast cancer cells. Pharmacokinetic studies on Sprague-Dawley rats revealed a remarkable increase in oral bioavailability (1.87-fold) with significant (p < 0.0001) enhancement in AUC0-72 h, t1/2 and MRT of TMX-PM4.5 than that of TMX-suspension. Thus, the results suggested that CMC-TS micelles are a promising carrier for TMX delivery.

Keywords: carboxymethyl chitosan, d-α-tocopherol succinate, pharmacokinetic, polymeric micelles, tamoxifen

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Authors: S. H. Park, D. W. You

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This study is about to the field survey and repair works in a marine approach-bride. In order to evaluate the stability of the ground and the structure, field surveys such as exterior inspection, non-destructive inspection, measurement, and geophysical exploration are carried out. Numerical analysis is conducted to investigate the cause of the abutment displacement at the same time. In addition, repair works are practiced to the region damaged with intent to sustain long-term safety.

Keywords: field survey, expansion joint, repair, maintenance

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Authors: Omid Adibi, Nategheh Najafpour, Bijan Farhanieh, Hossein Afshin

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Gas release from the pipelines is one of the main factors in the gas industry accidents. Released gas ejects from the pipeline as a free jet and in the growth process, the fuel gets mixed with the ambient air. Accordingly, an accidental spark will release the chemical energy of the mixture with an explosion. Gas explosion damages the equipment and endangers the life of staffs. So due to importance of safety in gas industries, prevision of accident can reduce the number of the casualties. In this paper, natural gas leakages from the low pressure pipelines are studied in two steps: 1) the simulation of mixing process and identification of flammable zones and 2) the simulation of wind effects on the mixing process. The numerical simulations were performed by using the finite volume method and the pressure-based algorithm. Also, for the grid generation the structured method was used. The results show that, in just 6.4 s after accident, released natural gas could penetrate to 40 m in vertical and 20 m in horizontal direction. Moreover, the results show that the wind speed is a key factor in dispersion process. In fact, the wind transports the flammable zones into the downstream. Hence, to improve the safety of the people and human property, it is preferable to construct gas facilities and buildings in the opposite side of prevailing wind direction.

Keywords: flammable zones, gas pipelines, numerical simulation, wind effects

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Authors: Abdelkader T. Ahmed

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Phosphate Rocks (PR) are natural sediment rocks. These rocks contain several chemical compositions of heavy metals and radioactive elements. Mining and transportation these rocks beside or through the natural water streams may lead to water contamination. When PR is in contact with water in the field, as a consequence of precipitation events, changes in water table or sinking in water streams, elements such as salts and heavy metals, may be released to the water. In this work, the leaching properties of PR in Nile River water was investigated by experimental lab work. The study focused on evaluating potential environmental impacts of some constituents, including phosphors, cadmium, curium and lead of PR on the water quality of Nile by applying tank leaching tests. In these tests the potential impact of changing conditions, such as phosphate content in PR, liquid to solid ratio (L/S) and pH value, was studied on the long-term release of heavy metals and salts. Experimental results showed that cadmium and lead were released in very low concentrations but curium and phosphors were in high concentrations. Results showed also that the release rate from PR for all constituents was low even in long periods.

Keywords: leaching tests, Nile river, phosphate rocks, water quality

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Authors: Jack L. Harris, Marya L. Doerfel, Hyunsook Youn, Minkyung Kim, Kautuki Sunil Jariwala

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Organizational resilience refers to the ability to sustain business or general work functioning despite wide-scale interruptions. We focus on organization and businesses as a pillar of their communities and how they attempt to sustain work when a natural disaster impacts their surrounding regions and economies. While it may be more common to think of resilience as a trait possessed by an organization, an emerging area of research recognizes that for organizations and businesses, resilience is a set of processes that are constituted through communication, social networks, and organizing. Indeed, five processes, robustness, rapidity, resourcefulness, redundancy, and external availability through social media have been identified as critical to organizational resilience. These organizing mechanisms involve multi-level coordination, where individuals intersect with groups, organizations, and communities. Because the nature of such interactions are often networks of people and organizations coordinating material resources, information, and support, they necessarily require some way to coordinate despite being displaced. Little is known, however, if physical and digital spaces can substitute one for the other. We thus are guided by the question, is digital space sufficient when disaster creates a scarcity of physical space? This study presents a cross-case comparison based on field research from four different regions of the United States that were impacted by Hurricanes Katrina (2005), Sandy (2012), Maria (2017), and Harvey (2017). These four cases are used to extend the science of resilience by examining multi-level processes enacted by individuals, communities, and organizations that together, contribute to the resilience of disaster-struck organizations, businesses, and their communities. Using field research about organizations and businesses impacted by the four hurricanes, we code data from interviews, participant observations, field notes, and document analysis drawn from New Orleans (post-Katrina), coastal New Jersey (post-Sandy), Houston Texas (post-Harvey), and the lower keys of Florida (post-Maria). This paper identifies an additional organizing mechanism, networked gathering spaces, where citizens and organizations, alike, coordinate and facilitate information sharing, material resource distribution, and social support. Findings show that digital space, alone, is not a sufficient substitute to effectively sustain organizational resilience during a disaster. Because the data are qualitative, we expand on this finding with specific ways in which organizations and the people who lead them worked around the problem of scarce space. We propose that gatherings after disaster are a sixth mechanism that contributes to organizational resilience.

Keywords: communication, coordination, disaster management, information and communication technologies, interorganizational relationships, resilience, work

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Authors: Muhammad Naeem, Juho Lee, Jin-Wook Yoo

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In this study, we hypothesized that prolonged gastrointestinal transit at the inflamed colon conferred by a pH-triggered mucoadhesive smart nanoparticulate drug delivery system aids in achieving selective and sustained levels of the drug within the inflamed colon for the treatment of ulcerative colitis. We developed budesonide-loaded pH-sensitive charge-reversal solid lipid nanoparticles (SLNs) using a hot homogenization method. Polyetylenimine (PEI) was used to render SLNs cationic (PEI-SLNs). Eudragit S100 (ES) was coated on PEI-SLNs for pH-trigger charge-reversal SLNs (ES-PEI-SLNs). Therapeutic potential of the prepared SNLs formulation was evaluated in ulcerative colitis in mice. The transmission electron microscopy, zeta size and zeta potential data showed the successful formation of SLNs formulations. SLNs and PEI-SLNs showed burst drug release in acidic pH condition mimicking stomach and early small intestine environment which limiting their application as oral delivery systems. However, ES-PEI-SLNs prevented a burst drug release in acidic pH conditions and showed sustained release at a colonic pH. Most importantly, the surface charge of ES-PEI-SLNs switched from negative to positive in colonic conditions by pH-triggered removal of ES coating and accumulated selectively in inflamed colon. Furthermore, a charge reversal ES-PEI-SLNs showed a superior mitigation of dextran sulfate sodium (DSS)-induced acute colitis in mice as compared to SLNs and PEI-SLNs treated groups. Moreover, histopathological analysis of distal colon sections stained with hematoxylin/eosin and E-cadherin immunostaining revealed attenuated inflammation in an ES-PEI-SLNs-treated group. We also found that ES-PEI-SLNs markedly reduced the myeloperoxidase level and expression of TNF-alpha in colon tissue. Our results suggest that the pH-triggered charge reversal SLNs presented in this study would be a promising approach for ulcerative colitis therapy.

Keywords: solid lipid nanoparticles, stimuli-triggered charge-reversal, ulcerative colitis, methacrylate copolymer, budesonide

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Authors: Vishwas Chakranarayan, Mariyam Al Salman

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Despite the global environmental threats, previous approaches used to overcome these problems have failed to prevent environmental degradation. Scholars believe that entrepreneurs can help conserve habitats, combat climate change, increase freshwater availability, sustain biodiversity, and reduce environmental degradation and deforestation. The pandemic is creating a different ecosystem for fostering the eco-entrepreneurship opportunities. However, attending a course physically is a challenge for many willing learners. Therefore, it is an opportune time to contemplate on developing a social entrepreneurship curriculum which can be offered online.

Keywords: ecopreneurship, environmental problems, environmental degradation, entrepreneurship education

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Authors: Betty Anson

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Researchers have found that mature sperm cells are not only devoid of mature MTDNA (mitochondrial DNA) but also lack a particular protein essential for DNA maintenance, known as mitochondrial transcription factor A, or TFAM (transcription factor A mitochondria). As a result, children get the DNA of certain important body functions only from their mothers. More experiments show that TFAM appears to burn out when it is used as a source of energy for sperm movement. This study investigates alternative sources of energy for sperm movement that could sustain the existence of TFAM.

Keywords: mItochondria, DNA, TFAM, sperm

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Authors: Sudhir Kumar, V. R. Sinha

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Background: The topical and systemic toxicity associated with present nonmelanoma skin cancer (NMSC) treatment therapy using 5-Fluorouracil (5-FU) make it necessary to develop a novel delivery system having lesser toxicity and better control over drug release. Solid lipid nanoparticles offer many advantages like: controlled and localized release of entrapped actives, nontoxicity, and better tolerance. Aim:-To investigate safety and efficacy of 5-FU loaded solid lipid nanoparticles as a topical delivery system for the treatment of nonmelanoma skin cancer. Method: Topical solid lipid nanoparticles of 5-FU were prepared using Compritol 888 ATO (Glyceryl behenate) as lipid component and pluronic F68 (Poloxamer 188), Tween 80 (Polysorbate 80), Tyloxapol (4-(1,1,3,3-Tetramethylbutyl) phenol polymer with formaldehyde and oxirane) as surfactants. The SLNs were prepared with emulsification method. Different formulation parameters viz. type and ratio of surfactant, ratio of lipid and ratio of surfactant:lipid were investigated on particle size and drug entrapment efficiency. Results: Characterization of SLNs like–Transmission Electron Microscopy (TEM), Differential Scannig calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), Particle size determination, Polydispersity index, Entrapment efficiency, Drug loading, ex vivo skin permeation and skin retention studies, skin irritation and histopathology studies were performed. TEM results showed that shape of SLNs was spherical with size range 200-500nm. Higher encapsulation efficiency was obtained for batches having higher concentration of surfactant and lipid. It was found maximum 64.3% for SLN-6 batch with size of 400.1±9.22 nm and PDI 0.221±0.031. Optimized SLN batches and marketed 5-FU cream were compared for flux across rat skin and skin drug retention. The lesser flux and higher skin retention was obtained for SLN formulation in comparison to topical 5-FU cream, which ensures less systemic toxicity and better control of drug release across skin. Chronic skin irritation studies lacks serious erythema or inflammation and histopathology studies showed no significant change in physiology of epidermal layers of rat skin. So, these studies suggest that the optimized SLN formulation is efficient then marketed cream and safer for long term NMSC treatment regimens. Conclusion: Topical and systemic toxicity associated with long-term use of 5-FU, in the treatment of NMSC, can be minimized with its controlled release with significant drug retention with minimal flux across skin. The study may provide a better alternate for effective NMSC treatment.

Keywords: 5-FU, topical formulation, solid lipid nanoparticles, non melanoma skin cancer

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Authors: Diemas Purnama Muhammad Firman Pratama, Denny Maulana Malik

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Development of Jatigede Dam that was the mega project in Indonesia, since 1963. Area of around Jatigede Dam is complex, it has structural geology active fault, and as possible can occur landslide. This research focus on soil test. The purpose of this research to know soil quality Jatigede Dam which caused by water seepage of Jatigede Dam, then can be made seepage modelling around Jatigede Dam including Cisampih Village. Method of this research is SRW (Soil Reaction to Water). There are three samples are taken nearby Jatigede Dam. Four paramaters to determine water seepage such as : V ( velocity of soil to release water), Dl (Ability of soil to release water), Ds (Ability of soil to absorb water), Dt (Ability of soil to hold water). meanwhile, another proscess of interaction beetween water and soil are produced angle, which is made of water flow and vertikal line. Called name SIAT. SIAT has two type is na1 and na2. Each samples has a value from the first sample is 280,333(degree), the second 270 (degree) and the third 270 (degree). The difference na1 is, water interaction towards Dt value angle, while na2 is water interaction towards Dl and Ds value angle. Result of calculating SRW method, first till third sample has a value 7, 11,5 and 9. Based on data, interpreted in around teritory of Jatigede Dam, will get easier impact from water seepage because, condition soil reaction too bad so, it can not hold water.

Keywords: Jatigede Dam, Cisampih village, water seepage, soil quality

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Authors: J. P. Lavande, A. V.Chandewar

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Mouth dissolving tablet is the speedily growing and highly accepted drug delivery system. This study was aimed at development of Ketorolac Tromethamine mouth dissolving tablet (MDTs), which can disintegrate or dissolve rapidly once placed in the mouth. Conventional Ketorolac tromethamine tablet requires water to swallow it and has limitation like low disintegration rate, low solubility etc. Ketorolac Tromethamine mouth dissolving tablets (formulation) consist of super-disintegrate like Heat Modified Karaya Gum, Co-treated Heat Modified Agar & Filler microcrystalline cellulose (MCC). The tablets were evaluated for weight variation, friability, hardness, in vitro disintegration time, wetting time, in vitro drug release profile, content uniformity. The obtained results showed that low weight variation, good hardness, acceptable friability, fast wetting time. Tablets in all batches disintegrated within 15-50 sec. The formulation containing superdisintegrants namely heat modified karaya gum and heat modified agar showed better performance in disintegration and drug release profile.

Keywords: mouth dissolving tablet, Ketorolac tromethamine, disintegration time, heat modified karaya gum, co-treated heat modified agar

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Authors: Riddhi Trivedi, Shrenik Shah

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For Si RNA to be delivered various biodegradable polymers are trialed by many researchers. One of them is Chitosan (CS) nanoparticles which have been extensively studied for siRNA delivery but the stability and efficacy of such particles are highly dependent on the types of cross-linker used. Hence the attempts are made in this study with PGA To address this issue, three common cross-linkers; Ethylene glycol diacrylate (ED) and poly-D-glutamic acid (PGA) were used to prepare siRNA loaded CS-ED/PGA nanoparticles by ionic gelation method. The nanoparticles which were obtained were compared for its characterization in terms of its physicochemical properties i.e. particle size of the resultant particles, zeta potential, its encapsulation capacity in the polymer. Among all the formulations prepared with different crosslinker PGA siRNA had the smallest particle size (ranged from 120 ± 1.7 to 500 ± 10.9 nm) with zeta potential ranged from 22.1 ± 1.5 to +32.4 ± 0.5 mV, and high entrapment ( > 91%) and binding efficiencies. Similarly, CS-ED nanoparticles showed better siRNA protection during storage at 4˚C and as determined by serum protection assay. TEM micrographs revealed the assorted morphology of CS-PGA-siRNA nanoparticles in contrast to irregular morphology displayed by CS-ED-siRNA. All siRNA loaded nanoparticles were found to give initial burst release which after some time followed by a sustained release of siRNA which were loaded inside. All the formulations showed concentration-dependent cytotoxicity with when cytotoxicity performed by HeLa and normal vero cell lines.

Keywords: chitosan, siRNA, cytotoxicity, cell line study

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Authors: Mohd Suhaizan Shamsuddin

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Urbanization exacerbates the environment quality and pressures of matured urban trees' growth and development in changing environment. The growth of struggled matured urban tree-roots by spreading within the existences of infrastructures, resulting in large damage to the structured and declined growth. Many physiological growths declined or damages by the present and installations of infrastructures within and nearby root zone. Afford to remain both matured urban tree and infrastructures as a service provider causes damage and death, respectively. Inasmuch, spending more expenditure on fixing both or removing matured urban trees as risky to the future environment as the mitigation methods to reduce the problems are unconcerned. This paper aims to explain mitigation method practices of reducing the encountered problems of matured urban tree-roots settling and infrastructures while modified urban soil to sustain at an optimum level. Three categories capturing encountered conflicts growth of matured urban tree-roots growth within and nearby infrastructures by mitigating the problems of limited soil spaces, poor soil structures and soil space barrier installations and maintenance. The limited soil space encountered many conflicts and identified six methods that mitigate the survival tree-roots, such as soil volume/mounding, soil replacement/amendment for the radial trench, soil spacing-root bridge, root tunneling, walkway/pavement rising/diverted, and suspended pavement. The limited soil spaces are mitigation affords of inadequate soil-roots and spreading root settling and modification of construction soil media since the barrier existed and installed in root trails or zones. This is the reason for enabling tree-roots spreading and finds adequate sources (nutrients, water uptake and oxygen), spaces and functioning to stability stand of root anchorage since the matured tree grows larger. The poor soil structures were identified as three methods to mitigate soil materials' problems, and fewer soil voids comprise skeletal soil, structural soil, and soil cell. Mitigation of poor soil structure is altering the existing and introducing new structures by modifying the quantities and materials ratio allowing more voids beneath for roots spreading by considering the above structure of foot and vehicle traffics functioning or load-bearing. The soil space barrier installations and maintenance recognized to sustain both infrastructures and tree-roots grown in limited spaces and its benefits, the root barrier installations and root pruning are recommended. In conclusion, these recommended methods attempt to mitigate the present problems encountered at a particular place and problems among tree-roots and infrastructures exist. The combined method is the best way to alleviates the conflicts since the recognized conflicts are between tree-roots and man-made while the urban soil is modified. These presenting methods are most considered to sustain the matured urban trees' lifespan growth in the urban environment.

Keywords: urban tree-roots, limited soil spaces, poor soil structures, soil space barrier and maintenance

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Authors: Grâce Chidikofan, François Pinta, A. Benoist, G. Volle, J. Valette

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Statement of the Problem: biomass gasification systems may be relevant for decentralized power generation from recoverable agricultural and wood residues available in rural areas. In recent years, many systems have been implemented in all over the world as especially in Cambodgia, India. Although they have many positive effects, these systems can also affect the environment and human health. Indeed, during the process of biomass gasification, black wastewater containing tars are produced and generally discharged in the local environment either into the rivers or on soil. However, in most environmental assessment studies of biomass gasification systems, the impact of these releases are underestimated, due to the difficulty of identification of their chemical substances. This work deal with the analysis of the environmental impacts of tars from wood gasification in terms of human toxicity cancer effect, human toxicity non-cancer effect, and freshwater ecotoxicity. Methodology: A Life Cycle Assessment (LCA) approach was adopted. The inventory of tars chemicals substances was based on experimental data from a downdraft gasification system. The composition of six samples from two batches of raw materials: one batch made of tree wood species (oak+ plane tree +pine) at 25 % moisture content and the second batch made of oak at 11% moisture content. The tests were carried out for different gasifier load rates, respectively in the range 50-75% and 50-100%. To choose the environmental impacts assessment method, we compared the methods available in SIMAPRO tool (8.2.0) which are taking into account most of the chemical substances. The environmental impacts for 1kg of tars discharged were characterized by ILCD 2011+ method (V.1.08). Findings Experimental results revealed 38 important chemical substances in varying proportion from one test to another. Only 30 are characterized by ILCD 2011+ method, which is one of the best performing methods. The results show that wood species or moisture content have no significant impact on human toxicity noncancer effect (HTNCE) and freshwater ecotoxicity (FWE) for water release. For human toxicity cancer effect (HTCE), a small gap is observed between impact factors of the two batches, either 3.08E-7 CTUh/kg against 6.58E-7 CTUh/kg. On the other hand, it was found that the risk of negative effects is higher in case of tar release into water than on soil for all impact categories. Indeed, considering the set of samples, the average impact factor obtained for HTNCE varies respectively from 1.64 E-7 to 1.60E-8 CTUh/kg. For HTCE, the impact factor varies between 4.83E-07 CTUh/kg and 2.43E-08 CTUh/kg. The variability of those impact factors is relatively low for these two impact categories. Concerning FWE, the variability of impact factor is very high. It is 1.3E+03 CTUe/kg for tars release into water against 2.01E+01 CTUe/kg for tars release on soil. Statement concluding: The results of this study show that the environmental impacts of tars emission of biomass gasification systems can be consequent and it is important to investigate the ways to reduce them. For environmental research, these results represent an important step of a global environmental assessment of the studied systems. It could be used to better manage the wastewater containing tars to reduce as possible the impacts of numerous still running systems all over the world.

Keywords: biomass gasification, life cycle analysis, LCA, environmental impact, tars

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Authors: Farnaz Sadeghi, Moslem Tavakol

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In this study, an attempt has been made to prepare a physically cross-linked gel by cooling of tannic acid (TA)-polyvinyl alcohol (PVA) solution that subsequently convert to antibacterial chemically cross-linked hydrogel by using electron beam irradiation. PVA is known for its biocompatibility and hydrophilicity, and TA is known for being a natural compound which can serve as a cross-linking agent and a therapeutic agent. Swelling behavior, gel content, pore size, and mechanical properties of hydrogels which prepared at 14, 28, and 56 (kGy) with different ratios of polymers were investigated. PVA-TA hydrogel showed sustained release of tannic acid as approximately 20% and 50% of loaded TA released from the hydrogel after 4 and 72 h release time. We found that gel content decreased and the moisture retention capability increased by an increase in TA composition. In addition, PVA-TA hydrogels showed a good antibacterial activity against S.aureus. MTT analysis indicated that close to 83% of fibroblast cells remained viable after 48 h exposure to hydrogel extract. Moreover, the cooling of 10% PVA solution containing 0.5 and 0.75% w/v tannic acid to room and refrigerator, respectively, led to formation of physical gel that did not present any flow index after inversion of hydrogel cast. According to the results, the hydrogel prepared by electron beam irradiation of blended PVA-TA solution could be further investigated as a promising candidate for wound healing.

Keywords: poly vinyl alcohol, tannic acid, electron beam irradiation, hydrogel wound dressing

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Authors: Cristina Munoz-Shuguli, Francisco Rodriguez, Julio Bruna, M. Jose Galotto, Abel Guarda

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The microbial contamination in fruits due to the presence of fungal is the most important cause of their deterioration and loss. The development of active food packaging materials with antifungal properties has been proposed as an innovative strategy in order to prevent this problem. In this way, natural compounds as the essential oils or their derivatives, also called volatile compounds (VC), can be incorporated in the food packaging materials to control the fungal growth during fruit packaging. However, if the VC is incorporated directly in the packaging material, it is released very fast due to VC high volatility. For this reason, the formation of inclusion complexes through the encapsulation of VC into beta-cyclodextrin (β-CD) and their incorporation in package materials is an alternative to maintain an antifungal atmosphere around the packaged fruits for longer times. In this context, the aim of this work was to develop inclusion complexes based in β-CD and VC (β-CD:VC) for further application in the antifungal food packaging materials development. β-CD:VC inclusion complexes were obtained with two different molar ratios 2:1 and 1:1, through co-precipitation method. The entrapment efficiency of β-CD:VC as well the release of antifungal compound from inclusion complexes exposed to different relative humidity (25, 50, and 97 %) to headspace were determined by gaseous chromatography (GC). Also, thermal and antimicrobial properties of β-CD:VC were determined through thermogravimetric analysis (TGA) and antifungal assays against Botrytis cinerea, respectively. GC results showed that β-CD:VC 2:1 had a higher entrapment efficiency than β-CD:VC 1:1, with values of 75.5 ± 3.71 % and 59.6 ± 1.51 %, respectively. It was probably because during the synthesis of β-CD:VC 1:1, there was less molecular space to the movement of VC molecules. Furthermore, the release of VC from β-CD:VC was directly related with the relative humidity. High amount of VC was released when the inclusion complexes were exposed to high humidity, possibly due to the interactions between the water molecules and the β-CD hydrophilic wall. On the other hand, a better thermal stability of VC in inclusion complexes allowed to verify its effective encapsulation into β-CD. Finally, antimicrobial assays showed that the inclusion complexes had a high antifungal activity at very low concentrations. Therefore, the results obtained in this work allow suggesting the β-CD:VC inclusion complexes as potential candidates to the development of fruit antifungal packaging materials, which activity is relative humidity dependent.

Keywords: Botrytis cinerea, fruit packaging, headspace release, volatile compounds

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Authors: Noor Shafifiyaz Mohd Yazid, Najihah Mohd Hashim, Hapipah Mohd Ali, Syam Mohan, Rosea Go

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Artocarpus kemando is a plant species from Moraceae family. This plant is used as household utensil by the local and the fruits are edible. The plants’ bark was used for the extraction process and yielded the chloroform crude extract which was used to screen for anticancer potential. The cytotoxic effect of the extract on CAOV-3 and WRL 68 cell lines were determined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide or MTT assays. Qualitative AO/PI assay was performed to confirm the apoptosis and necrosis process. Meanwhile, the measurement of cell loss, nuclear morphology, DNA content, cell membrane permeability, mitochondrial membrane potential changes and cytochrome c release from mitochondria were detected through cytotoxicity 3 assay. In MTT assay, A. kemando inhibited 50% growth of CAOV-3 cells at 27.9 ± 0:03, 20.1± 0:03, 18.21± 0:04 µg/mL after 24, 48 and 72 hour, respectively. The morphology changes can be seen on CAOV-3 with a production of cell membrane blebbing, cromatin condensation and apoptotic bodies. Evaluation of cytotoxicity 3 on CAOV-3 cells after treated with extract resulting loss of mitochondrial membrane potential and release of cytochrome c from mitochondria. The results demonstrated A. kemando has potentially anticancer agent, particularly on human ovarian cancer.

Keywords: anticancer, Artocarpus kemando, ovarian cancer, cytotoxicity

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Authors: Ariel Vilchez, Francisca Acevedo, Rodrigo Navia

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The wound healing process can be accelerated and improved by the action of antioxidants such as curcumin (Cur) over the tissues; however, the efficacy of curcumin used through the digestive system is not enough to exploit its benefits. Electrospinning presents an alternative to carry curcumin directly to the wounds, and polyhydroxybutyrate (PHB) is proposed as the matrix to load curcumin owing to its biodegradable and biocompatible properties. PHB is among 150 types of Polyhydroxyalkanoates (PHAs) identified, it is a natural thermoplastic polyester produced by microbial fermentation obtained from microorganisms. The proposed objective is to develop electrospun bacterial PHB-based microfibers containing curcumin for possible biomedical applications. Commercial PHB was solved in Chloroform: Dimethylformamide (4:1) to a final concentration of 7% m/V. Curcumin was added to the polymeric solution at 1%, and 7% m/m regarding PHB. The electrospinning equipment (NEU-BM, China) with a rotary collector was used to obtain Cur-PHB fibers at different voltages and flow rate of the polymeric solution considering a distance of 20 cm from the needle to the collector. Scanning electron microscopy (SEM) was used to determine the diameter and morphology of the obtained fibers. Thermal stability was obtained from Thermogravimetric (TGA) analysis, and Fourier Transform Infrared Spectroscopy (FT-IR) was carried out in order to study the chemical bonds and interactions. A preliminary curcumin release to Phosphate Buffer Saline (PBS) pH = 7.4 was obtained in vitro and measured by spectrophotometry. PHB fibers presented an intact chemical composition regarding the original condition (dust) according to FTIR spectra, the diameter fluctuates between 0.761 ± 0.123 and 2.157 ± 0.882 μm, with different qualities according to their morphology. The best fibers in terms of quality and diameter resulted in sample 2 and sample 6, obtained at 0-10kV and 0.5 mL/hr, and 0-10kV and 1.5 mL/hr, respectively. The melting temperature resulted near 178 °C, according to the bibliography. The crystallinity of fibers decreases while curcumin concentration increases for the studied interval. The curcumin release reaches near 14% at 37 °C at 54h in PBS adjusted to a quasi-Fickian Diffusion. We conclude that it is possible to load curcumin in PHB to obtain continuous, homogeneous, and solvent-free microfibers by electrospinning. Between 0% and 7% of curcumin, the crystallinity of fibers decreases as the concentration of curcumin increases. Thus, curcumin enhances the flexibility of the obtained material. HPLC should be used in further analysis of curcumin release.

Keywords: antioxidant, curcumin, polyhydroxybutyrate, wound healing

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Authors: Mohammad Hossein Pazandeh, Monir Doudi, Sona Rostampour Yasouri

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—Results The prudent administration of antibiotics aims to avoid the side effects and the microbes' resistance to antibiotics. An approach developing methods of local administration of antibiotics is especially required for localized infections caused by bacterial colonization of medical devices or implant materials. Among the wide variety of materials used as drug delivery systems, bioactive glasses (BG) have large utilization in regenerative medicine . firstly, the production of bioactive glass/nickel oxide/tin dioxide nanocomposite using sol-gel method, and then, the controlled release of imipenem from the double metal oxide/bioactive glass nanocomposite, and finally, the investigation of the antibacterial property of the nanocomposite. against a number of implant-related infectious agents. In this study, BG/SnO2 and BG/NiO single systema with different metal oxide present and BG/NiO/SnO2 nanocomposites were synthesized by sol-gel as drug carriers for tetracycline and imepinem. These two antibiotics were widely used for osteomyelitis because of its favorable penetration and bactericidal effect on all the probable osteomyelitis pathogens. The antibacterial activity of synthesized samples were evaluated against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa as bacteria model using disk diffusion method. The BG modification using metal oxides results to antibacterial property of samples containing metal oxide with highest efficiency for nancomposite. bioactivity of all samples was assessed by determining the surface morphology, structural and composition changes using scanning electron microscopy (SEM), FTIR and X-ray diffraction (XRD) spectroscopy, respectively, after soaking in simulated body fluid (SBF) for 28 days. The hydroxyapatite formation was clearly observed as a bioactivity measurement. Then, BG nanocomposite sample was loaded using two antibiotics, separately and their release profiles were studied. The BG nancomposite sample was shown the slow and continuous drug releasing for a period of 72 hours which is desirable for a drug delivery system. The loaded antibiotic nanocomposite sample retaining antibacterial property and showing inactivation effect against bacteria under test. The modified bioactive glass forming hydroxyapatite with controlled release drug and effective against bacterial infections can be introduced as scaffolds for bone implants after clinical trials for biomedical applications . Considering the formation of biofilm by infectious bacteria after sticking on the surfaces of implants, medical devices, etc. Also, considering the complications of traditional methods, solving the problems caused by the above-mentioned microorganisms in technical and biomedical industries was one of the necessities of this research.

Keywords: antibacterial, bioglass, drug delivery system, sol- gel

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Authors: Kaitlyn O'Mara, Michele Burford

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Estuaries and coastal bays can receive large quantities of sediment from surrounding catchments during flooding or high flow periods. Large river systems that feed freshwater into estuaries can flow through several catchments of varying geology. Human modification of catchments for agriculture, industry and urban use can contaminate soils with excess nutrients, trace metals and other pollutants. Land clearing, especially clearing of riparian vegetation, can accelerate erosion, mobilising, transporting and depositing soil particles into rivers, estuaries and coastal bays. In this study, a flood simulation experiment was used to study the flux of nutrients between soil particles and water during this erosion, transport and deposition process. Granite, sedimentary and basalt surface soils (as well as sub-soils of granite and sedimentary) were collected from eroding areas surrounding the Brisbane River, Australia. The <63 µm size fraction of each soil type was tumbled in freshwater for 3 days, to simulation flood erosion and transport, followed by stationary exposure to seawater for 4 weeks, to simulate deposition into estuaries. Filtered water samples were taken at multiple time points throughout the experiment and analysed for water nutrient concentrations. The highest rates of nutrient release occurred during the first hour of exposure to freshwater and seawater, indicating a chemical reaction with seawater that may act to release some nutrient particles that remain bound to the soil during turbulent freshwater transport. Although released at a slower rate than the first hour, all of the surface soil types showed continual ammonia, nitrite and nitrate release over the 4-week seawater exposure, suggesting that these soils may provide ongoing supply of these nutrients to estuarine waters after deposition. Basalt surface soil released the highest concentrations of phosphates and dissolved organic phosphorus. Basalt soils are found in much of the agricultural land surrounding the Brisbane River and contributed largely to the 2011 Brisbane River flood plume deposit in Moreton Bay, suggesting these soils may be a source of phosphate enrichment in the bay. The results of this study suggest that erosion of catchment soils during storm and flood events may be a source of nutrient supply in receiving waterways, both freshwater and marine, and that the amount of nutrient release following these events may be affected by the type of soil deposited. For example, flooding in different catchments of a river system over time may result in different algal and food web responses in receiving estuaries.

Keywords: flood, nitrogen, nutrient, phosphorus, sediment, soil

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Authors: M. Naveed Yasin, Robert Brooke, Andrew Chan, Geoffrey I. N. Waterhouse, Drew Evans, Darren Svirskis, Ilva D. Rupenthal

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Poly(3,4-ethylenedioxythiophene) (PEDOT) is a robust conducting polymer (CP) exhibiting high conductivity and environmental stability. It can be synthesized by either chemical, electrochemical or vapour phase polymerization (VPP). Dexamethasone sodium phosphate (dexP) is an anionic drug molecule which has previously been loaded onto PEDOT as a dopant via electrochemical polymerisation; however this technique requires conductive surfaces from which polymerization is initiated. On the other hand, VPP produces highly organized biocompatible CP structures while polymerization can be achieved onto a range of surfaces with a relatively straight forward scale-up process. Following VPP of PEDOT, dexP can be loaded and subsequently released via ion-exchange. This study aimed at preparing and characterising both non-porous and porous VPP PEDOT structures including examining drug loading and release via ion-exchange. Porous PEDOT structures were prepared by first depositing a sacrificial polystyrene (PS) colloidal template on a substrate, heat curing this deposition and then spin coating it with the oxidant solution (iron tosylate) at 1500 rpm for 20 sec. VPP of both porous and non-porous PEDOT was achieved by exposing to monomer vapours in a vacuum oven at 40 mbar and 40 °C for 3 hrs. Non-porous structures were prepared similarly on the same substrate but without any sacrificial template. Surface morphology, compositions and behaviour were then characterized by atomic force microscopy (AFM), scanning electron microscopy (SEM), x-ray photoelectron spectroscopy (XPS) and cyclic voltammetry (CV) respectively. Drug loading was achieved by 50 CV cycles in a 0.1 M dexP aqueous solution. For drug release, each sample was exposed to 20 mL of phosphate buffer saline (PBS) placed in a water bath operating at 37 °C and 100 rpm. Film was stimulated (continuous pulse of ± 1 V at 0.5 Hz for 17 mins) while immersed into PBS. Samples were collected at 1, 2, 6, 23, 24, 26 and 27 hrs and were analysed for dexP by high performance liquid chromatography (HPLC Agilent 1200 series). AFM and SEM revealed the honey comb nature of prepared porous structures. XPS data showed the elemental composition of the dexP loaded film surface, which related well with that of PEDOT and also showed that one dexP molecule was present per almost three EDOT monomer units. The reproducible electroactive nature was shown by several cycles of reduction and oxidation via CV. Drug release revealed success in drug loading via ion-exchange, with stimulated porous and non-porous structures exhibiting a proof of concept burst release upon application of an electrical stimulus. A similar drug release pattern was observed for porous and non-porous structures without any significant statistical difference, possibly due to the thin nature of these structures. To our knowledge, this is the first report to explore the potential of VPP prepared PEDOT for stimuli-responsive drug delivery via ion-exchange. The produced porous structures were ordered and highly porous as indicated by AFM and SEM. These porous structures exhibited good electroactivity as shown by CV. Future work will investigate porous structures as nano-reservoirs to increase drug loading while sealing these structures to minimize spontaneous drug leakage.

Keywords: PEDOT for ion-exchange drug delivery, stimuli-responsive drug delivery, template based porous PEDOT structures, vapour phase polymerization of PEDOT

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Authors: Imran Hashmi, Sipkaduwa Arachchige Sashika Sureni Wickramasooriya

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Gene-drive technology has emerged as a promising tool for disease control by influencing the population dynamics of disease-carrying organisms. Various gene drive mechanisms, derived from global laboratory experiments, aim to strategically manage and prevent the spread of targeted diseases. One prominent strategy involves population replacement, wherein genetically modified mosquitoes are introduced to replace the existing local wild population. To enhance our understanding and aid in the design of effective release strategies, we employ a comprehensive mathematical model. The utilized approach employs agent-based modeling, enabling the consideration of individual mosquito attributes and flexibility in parameter manipulation. Through the integration of an agent-based model and a meta-population spatial approach, the dynamics of gene drive mosquito spreading in a released site are simulated. The model's outcomes offer valuable insights into future population dynamics, providing guidance for the development of informed release strategies. This research significantly contributes to the ongoing discourse on the responsible and effective implementation of gene drive technology for disease vector control.

Keywords: gene drive, agent-based modeling, disease-carrying organisms, malaria

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Authors: Dinuka Herath, Shelley Harrington

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This paper prompts debate about whether disorganization can be positioned as a mechanism that facilitates the creation and enactment of important dynamic capabilities within an organization. This particular article is a conceptual exploration of the link between dynamic capabilities and disorganization and presents the case for agent-based modelling as a viable methodological tool which can be used to explore this link. Dynamic capabilities are those capabilities that an organization needs to sustain competitive advantage in complex environments. Disorganization is the process of breaking down restrictive organizational structures and routines that commonly reside in organizations in order to increase organizational performance. In the 20th century, disorganization was largely viewed as an undesirable phenomenon within an organization. However, the concept of disorganization has been revitalized and garnered research interest in the recent years due to studies which demonstrate some of the advantages of disorganization to an organization. Furthermore, recent Agent-based simulation studies have shown the capability of disorganization to be managed and argue for disorganization to be viewed as an enabler of organizational productivity. Given the natural state of disorganization and resulting fear this can create, this paper argues that instead of trying to ‘correct’ disorganization, it should be actively encouraged to have functional purpose. The study of dynamic capabilities emerged as a result of heightened dynamism and consequentially the very nature of dynamism denotes a level of fluidity and flexibility, something which this paper argues many organizations do not truly foster due to a constrained commitment to organization and order. We argue in this paper that the very state of disorganization is a state that should be encouraged to develop dynamic capabilities needed to not only deal with the complexities of the modern business environment but also to sustain competitive success. The significance of this paper stems from the fact that both dynamic capabilities and disorganization are two concepts that are gaining prominence in their respective academic genres. Despite the attention each concept has received individually, no conceptual link has been established to depict how they actually interact with each other. We argue that the link between these two concepts present a novel way of looking at organizational performance. By doing so, we explore the potential of these two concepts working in tandem in order to increase organizational productivity which has significant implications for both academics and practitioners alike.

Keywords: agent-based modelling, disorganization, dynamic capabilities, performance

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