Search results for: drug release metronidazole
1269 Estimation of Human Absorbed Dose Using Compartmental Model
Authors: M. Mousavi-Daramoroudi, H. Yousefnia, F. Abbasi-Davani, S. Zolghadri
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Dosimetry is an indispensable and precious factor in patient treatment planning to minimize the absorbed dose in vital tissues. In this study, compartmental model was used in order to estimate the human absorbed dose of 177Lu-DOTATOC from the biodistribution data in wild type rats. For this purpose, 177Lu-DOTATOC was prepared under optimized conditions and its biodistribution was studied in male Syrian rats up to 168 h. Compartmental model was applied to mathematical description of the drug behaviour in tissue at different times. Dosimetric estimation of the complex was performed using radiation absorbed dose assessment resource (RADAR). The biodistribution data showed high accumulation in the adrenal and pancreas as the major expression sites for somatostatin receptor (SSTR). While kidneys as the major route of excretion receive 0.037 mSv/MBq, pancreas and adrenal also obtain 0.039 and 0.028 mSv/MBq. Due to the usage of this method, the points of accumulated activity data were enhanced, and further information of tissues uptake was collected that it will be followed by high (or improved) precision in dosimetric calculations.Keywords: compartmental modeling, human absorbed dose, ¹⁷⁷Lu-DOTATOC, Syrian rats
Procedia PDF Downloads 1931268 Extracellular Phytase from Lactobacillus fermentum spp KA1: Optimization of Enzyme Production and Its Application for Improving the Nutritional Quality of Rice Bran
Authors: Neha Sharma, Kanthi K. Kondepudi, Naveen Gupta
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Phytases are phytate specific phosphatases catalyzing the step-wise dephosphorylation of phytate, which acts as an anti-nutritional factor in food due to its strong binding capacity to minerals. In recent years microbial phytases have been explored for improving nutritional quality of food. But the major limitation is acceptability of phytases from these microorganisms. Therefore, efforts are being made to isolate organisms which are generally regarded as safe for human consumption such as Lactic Acid Bacteria (LAB). Phytases from these organisms will have an edge over other phytase sources due to its probiotic attributes. Only few LAB have been reported to give phytase activity that too is generally seen as intracellular. LAB producing extracellular phytase will be more useful as it can degrade phytate more effectively. Moreover, enzyme from such isolate will have application in food processing also. Only few species of Lactobacillus producing extracellular phytase have been reported so far. This study reports the isolation of a probiotic strain of Lactobacillus fermentum spp KA1 which produces extracellular phytase. Conditions for the optimal production of phytase have been optimized and the enzyme production resulted in an approximately 13-fold increase in yield. The phytate degradation potential of extracellular phytase in rice bran has been explored and conditions for optimal degradation were optimized. Under optimal conditions, there was 43.26% release of inorganic phosphate and 6.45% decrease of phytate content.Keywords: Lactobacillus, phytase, phytate reduction, rice bran
Procedia PDF Downloads 1981267 “SockGEL/PLUG” Injectable Smart/Intelligent and Bio-Inspired Sol-Gel Nanomaterials for Simple and Complex Oro-Dental and Cranio-Maxillo-Facial Interventional Applications
Authors: Ziyad S. Haidar
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Millions of teeth are removed annually, and dental extraction is one of the most commonly performed surgical procedures globally. Whether due to caries, periodontal disease or trauma, exodontia and the ensuing wound healing and bone remodeling processes of the resultant socket (hole in the jaw bone) usually result in serious deformities of the residual alveolar osseous ridge and surrounding soft tissues (reduced height/width). Such voluminous changes render the placement of a proper conventional bridge, denture or even an implant-supported prosthesis extremely challenging. Further, most extractions continue to be performed with no regard for preventing the onset of alveolar osteitis (also known as dry socket, a painful and difficult-to-treat/-manage condition post-exodontia). Hence, such serious resorptive morphological changes often result in significant facial deformities and a negative impact on the overall Quality of Life (QoL) of patients (and oral health-related QoL), alarming, particularly for the geriatric with compromised healing and in light of the thriving longevity statistics. Opportunity: Despite advances in tissue/wound grafting, serious limitations continue to exist, including efficacy and clinical outcome predictability, cost, treatment time, expertise and risk of immune reactions. For cases of dry sockets, specifically, the commercially-available and often-prescribed home remedies are highly lacking. Indeed, most are not recommended for use anymore. Alveogyl is a fine example. Hence, there is a great market demand and need for alternative solutions. Solution: Herein, SockGEL/PLUG (patent pending), an all-natural, drug-free and injectable stimuli-responsive hydrogel, was designed, formulated, characterized and evaluated as an osteogenic, angiogenic, anti-microbial and pain-soothing suture-free intra-alveolar dressing, safe and efficacious for use in several oro-dental and cranio-maxillo-facial interventional applications; for example: in fresh dental extraction sockets, immediately post-exodontia. It is composed of FDA-approved, biocompatible and biodegradable polymers, self-assembled electro-statically to formulate a scaffolding matrix to (a) prevent the onset of alveolar osteitis via securing the fibrin-clot in situ and protecting/sealing the socket from contamination/infection; and (b) endogenously promote/accelerate wound healing and bone remodeling to preserve the volume of the alveolus. Findings: The intrinsic properties of the SockGEL/PLUG hydrogel were evaluated physico-chemico-mechanically for safety (cell viability), viscosity, rheology, bio-distribution and essentially, capacity to induce wound healing and osteogenesis (small defect, in vivo) without any signaling cues from exogenous cells, growth factors or drugs. The performed animal model of cranial critical-sized and non-vascularized bone defects shall provide vitally critical insights into the role and mechanism of the employed natural bio-polymer blend and gel product in endogenous reparative regeneration of soft tissues and bone morphogenesis. Alongside, the fine-tuning of our modified formulation method will further tackle appropriateness, reproducibility, scalability, ease and speed in producing stable, biodegradable and sterilizable stimuli (thermo-sensitive and photo-responsive) matrices (3-dimensional interpenetrating yet porous polymeric network) suitable for an intra-socket application, and beyond. Conclusions and Perspective: Findings are anticipated to provide sufficient evidence to translate into pilot clinical trials and validate the bionanomaterial before engaging the market for feasibility, acceptance and cost-effectiveness studies. The SockGEL/PLUG platform is patent pending: SockGEL is a bio-inspired drug-free hydrogel; SockPLUG is a drug-loaded hydrogel designed for complex indications.Keywords: hydrogel, injectable, dentistry, craniomaxillofacial complex, bioinspired, nanobiotechnology, biopolymer, sol-gel, stimuli-responsive, matrix, tissue engineering, regenerative medicine
Procedia PDF Downloads 721266 Potential and Techno-Economic Analysis of Hydrogen Production from Portuguese Solid Recovered Fuels
Authors: A. Ribeiro, N. Pacheco, M. Soares, N. Valério, L. Nascimento, A. Silva, C. Vilarinho, J. Carvalho
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Hydrogen will play a key role in changing the current global energy paradigm, associated with the high use of fossil fuels and the release of greenhouse gases. This work intended to identify and quantify the potential of Solid Recovered Fuels (SFR) existing in Portugal and project the cost of hydrogen, produced through its steam gasification in different scenarios, associated with the size or capacity of the plant and the existence of carbon capture and storage (CCS) systems. Therefore, it was performed a techno-economic analysis simulation using an ASPEN base model, the H2A Hydrogen Production Model Version 3.2018. Regarding the production of SRF, it was possible to verify the annual production of more than 200 thousand tons of SRF in Portugal in 2019. The results of the techno-economic analysis simulations showed that in the scenarios containing a high (200,000 tons/year) and medium (40,000 tons/year) amount of SFR, the cost of hydrogen production was competitive concerning the current prices of hydrogen. The results indicate that scenarios 1 and 2, which use 200,000 tons of SRF per year, have lower hydrogen production values, 1.22 USD/kg H2 and 1.63 USD/kg H2, respectively. The cost of producing hydrogen without carbon capture and storage (CCS) systems in an average amount of SFR (40,000 tons/year) was 1.70 USD/kg H2. In turn, scenarios 5 (without CCS) and 6 (with CCS), which use only 683 tons of SFR from urban sources, have the highest costs, 6.54 USD/kg H2 and 908.97 USD/kg H2, respectively. Therefore, it was possible to conclude that there is a huge potential for the use of SRF for the production of hydrogen through steam gasification in Portugal.Keywords: gasification, hydrogen, solid recovered fuels, techno-economic analysis, waste-to-energy
Procedia PDF Downloads 1251265 Nanoscale Metal-Organic Framework Coated Carbon Nitride Nanosheet for Combination Cancer Therapy
Authors: Rui Chen, Jinfeng Zhang, Chun-Sing Lee
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In the past couple of decades, nanoscale metal-organic frameworks (NMOFs) have been highlighted as promising delivery platforms for biomedical applications, which combine many potent features such as high loading capacity, progressive biodegradability and low cytotoxicity. While NMOF has been extensively used as carriers for drugs of different modalities, so far there is no report on exploiting the advantages of NMOF for combination therapy. Herein, we prepared core-shell nanoparticles, where each nanoparticle contains a single graphitic-phase carbon nitride (g-C3N4) nanosheet encapsulated by a zeolitic-imidazolate frameworks-8 (ZIF-8) shell. The g-C3N4 nanosheets are effective visible-light photosensitizer for photodynamic therapy (PDT). When hosting DOX (doxorubicin), the as-synthesized core-shell nanoparticles could realize combinational photo-chemo therapy and provide dual-color fluorescence imaging. Therefore, we expect NMOFs-based core-shell nanoparticles could provide a new way to achieve much-enhanced cancer therapy.Keywords: carbon nitride, combination therapy, drug delivery, nanoscale metal-organic frameworks
Procedia PDF Downloads 4251264 Design, Synthesis, and Evaluation of Small Peptides for Managing Inflammation: Inhibition to Substrate Approach
Authors: Palwinder Singh, Baljit Kaur, Sukhmeet Kaur
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Amongst a library of rationally designed small peptides, (H)Gly-Gly-Phe-Leu(OMe) was identified, reducing prostaglandin production of COX-2 with IC50 60 nM vs. 6000 nM for COX-1. The 5 mg Kg-1 dose of this compound rescued albino mice by 80% from capsaicin-induced paw licking and recovered it by 60% from carrageenan-induced inflammation. The mode of action of the compound for targeting COX-2, iNOS, and VGSC was investigated by using substances P, L-arginine, and veratrine, respectively, as the biomarkers. The interactions of the potent compound with COX-2 were supported by the isothermal calorimetry experiments showing Ka 6.10±1.10x104 mol-1 and ΔG -100.3 k J mol-1 in comparison to Ka 0.41x103 ±0.09 mol-1 and ΔG -19.2±0.06 k J mol-1 for COX-1. This compound did not show toxicity up to 2000 mg Kg-1 dose. Furthermore, beyond the conventional mode of working with anti-inflammatory agents through enzyme inhibition, COX-2 was provided with a peptide-based alternate substrate. Proline-centered pentapeptide iso-conformational to arachidonic acid exhibited appreciable selectivity for COX-2 overcoming acetic acid and formalin-induced pain in rats to almost 80% and was treated as a substrate by the enzyme. Hence, we suggest small peptides as highly potent and promising candidates for their further development into an anti-inflammatory drug.Keywords: small peptides, cyclooxygenase, inflammation, substrate
Procedia PDF Downloads 881263 Polymer-Nanographite Nanocomposites for Biosensor Applications
Authors: Payal Mazumdar, Sunita Rattan, Monalisa Mukherjee
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Polymer nanocomposites are a special class of materials having unique properties and wide application in diverse areas such as EMI shielding, sensors, photovoltaic cells, membrane separation properties, drug delivery etc. Recently the nanocomposites are being investigated for their use in biomedical fields as biosensors. Though nanocomposites with carbon nanoparticles have received worldwide attention in the past few years, comparatively less work has been done on nanographite although it has in-plane electrical, thermal and mechanical properties comparable to that of carbon nanotubes. The main challenge in the fabrication of these nanocomposites lies in the establishment of homogeneous dispersion of nanographite in polymer matrix. In the present work, attempts have been made to synthesize the nanocomposites of polystyrene and nanographite using click chemistry. The polymer and the nanographite are functionalized prior to the formation of nanocomposites. The polymer, polystyrene, was functionalized with alkyne moeity and nanographite with azide moiety. The fabricating of the nanocomposites was accomplished through click chemistry using Cu (I)-catalyzed Huisgen dipolar cycloaddition. The functionalization of filler and polymer was confirmed by NMR and FTIR. The nanocomposites formed by the click chemistry exhibit better electrical properties and the sensors are evaluated for their application as biosensors.Keywords: nanocomposites, click chemistry, nanographite, biosensor
Procedia PDF Downloads 3061262 The Effects of Zinc Oxide Nanoparticles Loaded with Indole-3-Acetic Acid and Indole-3-Butyric Acid on in vitro Rooting of Apple Microcuttings
Authors: Shabnam Alizadeh, Hatice Dumanoglu
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Plant tissue culture is a substantial plant propagation technique for mass clonal production throughout the year, regardless of time in fruit species. However, the rooting achievement must be enhanced in the difficult-to-root genotypes. Classical auxin applications in clonal propagation of these genotypes are inadequate to solve the rooting problem. Nanoparticles having different physical and chemical properties from bulk material could enhance the rooting success of controlled release of these substances when loaded with auxin due to their ability to reach the active substance up to the target cells as a carrier system.The purpose of this study is to investigate the effects of zinc oxide nanoparticles loaded with indole-3-acetic acid (IAA-nZnO) and indole-3-butyric acid (IBA-nZnO) on in vitro rooting of microcuttings in a difficult-to-root apple genotype (Malus domestica Borkh.). Rooting treatments consisted of IBA or IAA at concentrations of 0.5, 1.0, 2.0, 3.0 mg/L; nZnO, IAA-nZnO and IBA-nZnO at doses of 0.0, 1.0, 2.0, 3.0, 4.0, 5.0, 6.0 mg/L were used. All components were added to the Murashige and Skoog (MS) basal medium at strength ½ with 2% sucrose and 0.7% agar before autoclaving. In the study, no rooting occurred in control and nZnO applications. Especially, 1.0 mg/L and 2.0 mg/L IBA-nZnO nanoparticle applications (containing 0.5 mg/L and 0.9 mg/L IBA), respectively with rooting rates of 40.3% and 70.4%, rooting levels of 2.0±0.4 and 2.3±0.4, 2.6±0.7 and 2.5±0.6 average root numbers and 20.4±1.6 mm and 20.2±3.4 mm average root lengths put forward as effective applications.Keywords: Auxin, Malus, nanotechnology, zinc oxide nanoparticles
Procedia PDF Downloads 1441261 Evaluation of Hospital Antibiotic Policy Implementation at the Oncosurgery Ward: A Six Years' Experience
Authors: Aneta Nitsch-Osuch, Damian Okrucinski, Magdalena Dawgialło, Izabela Gołębiak, Ernest Kuchar
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The Hospital Antibiotic Policy (HAP) should be implemented to rationalize the antibiotic use and to decrease the risk of spreading of spreading of resistant bacteria. The aim of our study was to describe the antibiotic consumption patterns at the single oncosurgery ward before and after implementation of the HAP. We conducted a retrospective analysis of the antibiotic use at the Oncosurgery Ward in Warsaw (Poland) in years 2011-2016. Calculations were based on daily defined doses (DDDs), DDDs/100 hospitalizations and DDDs/100 person-days, drug utilization rates (DU 90% and DU 100%) were also analysed. After implementation of the HAP, the total antibiotic consumption increased (365.35 DDD in 2011 vs. 1359,22 DDD in 2016). The significant change was observed in antibiotic consumption patterns: the use of amoxicillin clavulanate and carbapenems or glycopeptides decreased significantly (p < 0,05), while the use of ciprofloxacin and aminoglycosides increased (p < 0,05). The DU100% rate varied from 6 in 2011 to 12 in 2016; while DU 90% rate varied from 2 in 2011 to 3-5 in 2013-2016. Although the implementation of the HAP did not result in the decreased total antibiotic consumption, it provided favorable changes in the antibiotic consumption patterns.Keywords: antibiotics, hospital, policy, stewardship
Procedia PDF Downloads 2471260 Anti-Diabetic Effect of Withania somnifera in Alloxan Induced Diabetic Rabbits
Authors: Farah Ali, Tehreem Fiayyaz, Laeeq Akbar Lodhi, Imran Mirza
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The present work was undertaken to investigate effects of various extracts of W. somnifera (WS) for anti-diabetic activity in alloxan induced diabetic rabbits. Animals were divided into nine groups of six rabbits each. The animals of group 1 and 2 were given lactose (250 mg/kg, p.o) and WS root powder (100 mg/kg, p.o) respectively daily from day 1-20. Animals of group 3 were given alloxan (100 mg/kg, i.v) as a single dose on day 1. Powdered root of WS in the doses of 100, 150, 200 mg/kg and its aqueous (AWS) and ethanol extracts (EWS) (equivalent to 200 mg/kg of crude drug) were given to the treated animals (groups 4-8), respectively orally for three weeks (day 1-20 o.d), along with alloxan (100 mg/kg, i.v) as a single dose on day 1. Group 9 was given metformin (200 mg/kg) daily from day 1-20, along with a single dose of alloxan (100 mg/ kg, i.v) on day 1. Fasting serum glucose concentration in groups 3-9 was increased significantly (p<0.05) on day 3 as compared to normal control (NC) group (1). WS (100, 150, 200 mg/kg, p.o) decreased the fasting serum glucose concentration, with a maximum decrease (88.3 mg/dl) in group 2 (treated control) on day 21 of the experiment. These results indicate that metformin (reference control), (AWS) and (EWS) significantly antagonized the diabetic effects of alloxan.Keywords: diabetes, serum, glucose, blood, sugar, rabbits
Procedia PDF Downloads 6531259 Investigation of Flame and Soot Propagation in Non-Air Conditioned Railway Locomotives
Authors: Abhishek Agarwal, Manoj Sarda, Juhi Kaushik, Vatsal Sanjay, Arup Kumar Das
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Propagation of fire through a non-air conditioned railway compartment is studied by virtue of numerical simulations. Simultaneous computational fire dynamics equations, such as Navier-Stokes, lumped species continuity, overall mass and energy conservation, and heat transfer are solved using finite volume based (for radiation) and finite difference based (for all other equations) solver, Fire Dynamics Simulator (FDS). A single coupe with an eight berth occupancy is used to establish the numerical model, followed by the selection of a three coupe system as the fundamental unit of the locomotive compartment. Heat Release Rate Per Unit Area (HRRPUA) of the initial fire is varied to consider a wide range of compartmental fires. Parameters, such as air inlet velocity relative to the locomotive at the windows, the level of interaction with the ambiance and closure of middle berth are studied through a wide range of numerical simulations. Almost all the loss of lives and properties due to fire breakout can be attributed to the direct or indirect exposure to flames or to the inhalation of toxic gases and resultant suffocation due to smoke and soot. Therefore, the temporal stature of fire and smoke are reported for each of the considered cases which can be used in the present or extended form to develop guidelines to be followed in case of a fire breakout.Keywords: fire dynamics, flame propagation, locomotive fire, soot flow pattern, non-air-conditioned coaches
Procedia PDF Downloads 2931258 Cytotoxic Activity against Hepatocarcinoma and Cholangiocarcinoma Cells of Four Cathartic Herbal Medicines
Authors: Pranporn Kuropakornpong, Srisopa Ruangnoo, Arunporn Itharat
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Liver cancer has the highest prevalence rate in the North and Northeast of Thailand. Four Thai medicinal plants such as resin of Ferula asafoetida Regel, latex of Aloe barbadensis Miller leaves, roots of Baliospermum manotanum, and latex of Garcinia hanburyi Hook are used in Thai traditional medicine as cathartic drug and detoxification in liver cancer patients. Thus, this research aimed to evaluate the cytotoxic activity of these plants against hepatocarcinoma (HepG2) and cholangiocarcinoma (KKU-M156) cells by SRB assay. These plants were macerated in 95% ethanol. The results showed that roots of Baliospermum manotanum and latex of Garcinia hanburyi Hook showed the strongest cytotoxicity against HepG2 (IC50 = 3.03+0.91 and 0.62+0.01µg/ml, respectively) and KKU-M156 (IC50 = 0.978+0.663 and 0.006+0.005 µg/ml, respectively). Latex of Garcinia hanburyi Hook also showed high cytotoxicity against normal cell line (IC50=8.86+0.31 µg/ml), and even though its selective values are high, dose of this herb should be limited.Keywords: cholangiocarcinoma, cytotoxic activity, Garcinia hanburyi Hook, hepatocarcinoma
Procedia PDF Downloads 4511257 Management of Therapeutic Anticancer at Oran Teaching Hospital, Algeria
Authors: S. Boulenouar, M. Sefir, M. Benahmed
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All facilities need medication and other pharmaceuticals for their operation. Management and supply is therefore to provide the different services of the facility goods and services in required quantity and quality. The permanent availability of drugs in the facilities is very difficult because most face many difficulties at the inventory management and drug supplies. Therefore, it is necessary for each health facility to know the causes for the malfunction of its management system to cope with them. It is in this context that we have undertaken to conduct this study to know the causes which should be taken into consideration by the concerned authorities to carry out their mission, which is to provide quality health care for the population. In terms of financial resources, the budget for medicines represents a significant part of the budget of the pharmacy. Our study shows that the share of the hospital budget reserved for the drugs procurement represent on average 70% of the budget of the pharmacy. The results show a state of lack of anticancer drugs at Oran teaching hospital. The analysis of the management process allowed us to know the level that the problem of stock-outs of anti-cancer drugs is at. Suggestions were made to that effect to improve the availability for these products and to respond better to the needs of patients.Keywords: anticancer drugs, health care facility, budget, hospital pharmacist, hospital service
Procedia PDF Downloads 4461256 Psychometric Analysis of Educators’ Perceptions of North Carolina’s School-Based Mental Health Policy
Authors: Kathryn Watson
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In 2020 North Carolina passed legislation mandating all educators be trained in identifying, referring, and supporting students showing signs of mental health issues, drug use, suicidal ideation, and sex trafficking. This study collected survey responses from 226 educators in North Carolina to better understand their perspectives on the legislation and their self-efficacy in supporting student mental health needs. Key findings of the study reveal that the mandated trainings increased educator awareness of student mental health, and higher awareness was linked to higher self-efficacy in supporting student mental health needs. Additionally, the results showed that educators who identify as Black had lower levels of self-efficacy in supporting student mental health. Additionally, rural educators were least likely to support the legislation in comparison to their urban and suburban counterparts. These findings can help inform policymakers in evaluating the policy and district decision-makers in selecting and implementing school-based mental health training.Keywords: school-based mental health, education policy, student health, North Carolina, K-12 education
Procedia PDF Downloads 581255 Synthesis and Cytotoxic Activity of New Quinazolinone-Based Compounds against Human Breast Cancer Cell Line MCF-7
Authors: Maryam Zahedifard, Fadhil Lafta Faraj, Maryam Hajrezaie, Nazia Abdul Majid, Mahmood Ameen Abdulla, Hapipah Mohd Ali
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In the current study, we prepared two new quinazoline schiff bases through condensation reaction of 2-aminobenzhydrazide with 5-bromosalicylaldehyde and 3-methoxy-5-bromosalicylaldehyde. The chemical structures of both newly synthesized compounds (1 and 2) were confirmed by FT-IR and X-ray crystallography studies. The cytotoxic effect of compounds was investigated against MCF-7 human breast cancer cells. MTT results showed that (1) and (2) decreased the viability of MCF-7 cells in a time-dependent manner, exhibiting an IC50 value of 3.23 ± 0.28 µg/mL and 3.41 ± 0.34 µg/mL, respectively, after a 72-hours treatment period. In contrast, they did not show significant anti-proliferative effect towards MCF-10A normal breast cells and WRL-68 normal liver cells. We found a perturbation in mitochondrial membrane potential and increased cytochrome c release from the mitochondria to the cytosol, suggesting an activation of apoptosis by compounds, which was confirmed by activation of the initiator caspase-9 and the executioner caspases-3/7. (1) was also able to trigger extrinsic pathway via activation of caspase-8 and inhibition of NF-κB translocation. The acute toxicity test showed no toxicity effect of the compounds in rats. Our results showed that the selected synthesized compounds are highly potent to induce apoptosis in MCF-7 cells via either intrinsic or extrinsic mitochondrial pathway.Keywords: Quinazoline Schiff base, apoptosis, MCF-7 human breast cancer cell line, caspase, NF-κB translocation
Procedia PDF Downloads 4921254 Multifluid Computational Fluid Dynamics Simulation for Sawdust Gasification inside an Industrial Scale Fluidized Bed Gasifier
Authors: Vasujeet Singh, Pruthiviraj Nemalipuri, Vivek Vitankar, Harish Chandra Das
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For the correct prediction of thermal and hydraulic performance (bed voidage, suspension density, pressure drop, heat transfer, and combustion kinetics), one should incorporate the correct parameters in the computational fluid dynamics simulation of a fluidized bed gasifier. Scarcity of fossil fuels, and to fulfill the energy demand of the increasing population, researchers need to shift their attention to the alternative to fossil fuels. The current research work focuses on hydrodynamics behavior and gasification of sawdust inside a 2D industrial scale FBG using the Eulerian-Eulerian multifluid model. The present numerical model is validated with experimental data. Further, this model extended for the prediction of gasification characteristics of sawdust by incorporating eight heterogeneous moisture release, volatile cracking, tar cracking, tar oxidation, char combustion, CO₂ gasification, steam gasification, methanation reaction, and five homogeneous oxidation of CO, CH₄, H₂, forward and backward water gas shift (WGS) reactions. In the result section, composition of gasification products is analyzed, along with the hydrodynamics of sawdust and sand phase, heat transfer between the gas, sand and sawdust, reaction rates of different homogeneous and heterogeneous reactions is being analyzed along the height of the domain.Keywords: devolatilization, Eulerian-Eulerian, fluidized bed gasifier, mathematical modelling, sawdust gasification
Procedia PDF Downloads 1071253 Exploring Psychosocial Stressors in Crack Cocaine Use
Authors: Yaa Asuaba Duopah, Lisa Moran, Khalifa Elmusharaf, Dervla Kelly
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Background: Research has identified a strong link between stress and drug use behaviours. Also, it has been established that the prolonged use of crack cocaine stimulates emotional, cognitive, neurological, and social changes. This paper examines the psychosocial stressors associated with crack cocaine use. Methodology: The study is qualitative and adopts a critical realist approach. Data was collected through 26 face-to-face, in-depth, semi-structured interviews with people who use crack cocaine. Study participants were recruited through two addiction services using purposive. Participants consisted of 15 males and 11 females between the ages of 24-57 years. Data were analysed using thematic analysis. Results: Cravings, financial hardship, family breakdown, and emotional stimulation were revealed as psychosocial stressors associated with crack cocaine use. Conclusion: Addressing the psychosocial stressors identified in this paper through targeted interventions and supportive policies is crucial for improving the well-being of persons who use crack cocaine. Collaboration between addiction, mental health, and support services is recommended to develop and deliver these interventions.Keywords: psychological stress, substance misuse disorder, mental health, coping
Procedia PDF Downloads 541252 Effects of Aromatase Inhibitor (Fadrozole) Induced Sex-Reversal in Chicken (Gimmizah strain) on Morphology
Authors: Hatem Shreha
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Aromatase inhibitors administered before sexual differentiation of the gonads can induce sex reversal in female chickens (phenotypic male). To analyze the process of sex reversal, we have followed for several months the changes induced by Fadrozole, a nonsteroidal aromatase inhibitor on the morphology of female sex-reversed and female sex-reversed supplemented with L-tyrosine which was previously shown to stimulate the release of Gn Rh. Fadrozole (1mg/egg) was injected into eggs on day four of incubation, phenotypic males and phenotypic males treated with L-tyrosine and males hatched from eggs injected Fadrozole were sacrificed by slaughtering at 16 weeks old and the remaining chicks were sacrificed at 28 weeks old. Both sexes from control chickens were sacrificed at the same age (16 &28 weeks). Hatchability, behavior, body weight, shank length, comb weight, testes weight, blood cells count and wattle weight of sex reversal were tested at 16 and 28 weeks. The results showed that body weight, comb weight, wattles weight and shank length of sex-reversed females were significantly different from control female. Behavior of phenotypic males and phenotypic males fed on L- tyrosine showed aggressive sexual behavior like that of control males and absence of laying behavior. In conclusion our results confirm that Fedrazole injection in eggs before sex differentiation produce a male behavior and morphological index of male in female chicken.Keywords: sex reversal, fadrozole, phenotypic male, L- tyrosine
Procedia PDF Downloads 6101251 Medical Workforce Knowledge of Adrenaline (Epinephrine) Administration in Anaphylaxis in Adults Considerably Improved with Training in an UK Hospital from 2010 to 2017
Authors: Jan C. Droste, Justine Burns, Nithin Narayan
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Introduction: Life-threatening detrimental effects of inappropriate adrenaline (epinephrine) administration, e.g., by giving the wrong dose, in the context of anaphylaxis management is well documented in the medical literature. Half of the fatal anaphylactic reactions in the UK are iatrogenic, and the median time to a cardio-respiratory arrest can be as short as 5 minutes. It is therefore imperative that hospital doctors of all grades have active and accurate knowledge of the correct route, site, and dosage of administration of adrenaline. Given this time constraint and the potential fatal outcome with inappropriate management of anaphylaxis, it is alarming that surveys over the last 15 years have repeatedly shown only a minority of doctors to have accurate knowledge of adrenaline administration as recommended by the UK Resuscitation Council guidelines (2008 updated 2012). This comparison of survey results of the medical workforce over several years in a small NHS District General Hospital was conducted in order to establish the effect of the employment of multiple educational methods regarding adrenaline administration in anaphylaxis in adults. Methods: Between 2010 and 2017, several education methods and tools were used to repeatedly inform the medical workforce (doctors and advanced clinical practitioners) in a single district general hospital regarding the treatment of anaphylaxis in adults. Whilst the senior staff remained largely the same cohort, junior staff had changed fully in every survey. Examples included: (i) Formal teaching -in Grand Rounds; during the junior doctors’ induction process; advanced life support courses (ii) In-situ simulation training performed by the clinical skills simulation team –several ad hoc sessions and one 3-day event in 2017 visiting 16 separate clinical areas performing an acute anaphylaxis scenario using actors- around 100 individuals from multi-disciplinary teams were involved (iii) Hospital-wide distribution of the simulation event via the Trust’s Simulation Newsletter (iv) Laminated algorithms were attached to the 'crash trolleys' (v) A short email 'alert' was sent to all medical staff 3 weeks prior to the survey detailing the emergency treatment of anaphylaxis (vi) In addition, the performance of the surveys themselves represented a teaching opportunity when gaps in knowledge could be addressed. Face to face surveys were carried out in 2010 ('pre-intervention), 2015, and 2017, in the latter two occasions including advanced clinical practitioners (ACP). All surveys consisted of convenience samples. If verbal consent to conduct the survey was obtained, the medical practitioners' answers were recorded immediately on a data collection sheet. Results: There was a sustained improvement in the knowledge of the medical workforce from 2010 to 2017: Answers improved regarding correct drug by 11% (84%, 95%, and 95%); the correct route by 20% (76%, 90%, and 96%); correct site by 40% (43%, 83%, and 83%) and the correct dose by 45% (27%, 54%, and 72%). Overall, knowledge of all components -correct drug, route, site, and dose-improved from 13% in 2010 to 62% in 2017. Conclusion: This survey comparison shows knowledge of the medical workforce regarding adrenaline administration for treatment of anaphylaxis in adults can be considerably improved by employing a variety of educational methods.Keywords: adrenaline, anaphylaxis, epinephrine, medical education, patient safety
Procedia PDF Downloads 1281250 Gas Chromatography Coupled to Tandem Mass Spectrometry and Liquid Chromatography Coupled to Tandem Mass Spectrometry Qualitative Determination of Pesticides Found in Tea Infusions
Authors: Mihai-Alexandru Florea, Veronica Drumea, Roxana Nita, Cerasela Gird, Laura Olariu
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The aim of this study was to investigate the residues of pesticide found in tea water infusions. A multi-residues method to determine 147 pesticides has been developed using the QuEChERS (Quick, Easy, Cheap, Effective, Rugged, Safe) procedure and dispersive solid phase extraction (d-SPE) for the cleanup the pesticides from complex matrices such as plants and tea. Sample preparation was carefully optimized for the efficient removal of coextracted matrix components by testing more solvent systems. Determination of pesticides was performed using GC-MS/MS (100 of pesticides) and LC-MS/MS (47 of pesticides). The selected reaction monitoring (SRM) mode was chosen to achieve low detection limits and high compounds selectivity and sensitivity. Overall performance was evaluated and validated according to DG-SANTE Guidelines. To assess the pesticide residue transfer rate (qualitative) from dried tea in infusions the samples (tea) were spiked with a mixture of pesticides at the maximum residues level accepted for teas and herbal infusions. In order to investigate the release of the pesticides in tea preparations, the medicinal plants were prepared in four ways by variation of water temperature and the infusion time. The pesticides from infusions were extracted using two methods: QuEChERS versus solid-phase extraction (SPE). More that 90 % of the pesticides studied was identified in infusion.Keywords: tea, solid-phase extraction (SPE), selected reaction monitoring (SRM), QuEChERS
Procedia PDF Downloads 2131249 Management of Pain in Patients under Vitamin K Antagonists: Experience of the Unit of Clinical Pharmacology of EHU Oran, Algeria
Authors: Amina Bayazid, Habiba Fetati, Houari Toumi
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Introduction: The clinical value of vitamin K antagonists (VKA) has been widely demonstrated in numerous indications. Unfortunately, VKA are not devoid of drawbacks and risk of serious bleeding. The iatrogenic induced by these drugs is a major public health problem. Patients & Methods: We conducted a retrospective study period extending from February 2012 to August 2013 in the pharmacovigilance service of EHUO (clinical pharmacology unit). The prescription of painkillers was analyzed in patients on VKA followed at our level. The influence of these analgesics on the evolution of the INR is an important component in our work. Results: We counted a total of 195 patients, of whom 32 (or 16.41% of the total population) had received analgesic treatment. The frequencies of different categories of analgesics administered were: • Analgesics opioids: 0% • Analgesics weak opioids: Tramadol: 21.87% • The non-opioid analgesics: -AINS: 71.87% (indomethacin: 68.75% ibuprofen: 3.12%) - Paracetamol: 6.25% -Salicyles (Acetylsalicylic acid): 0%. Conclusion: The management of pain in patients under vitamin K antagonists has special features, given their many drug interactions with analgesics and their influence on the evolution of the INR which can have dramatic consequences. As such, special attention must be paid to the use of analgesics in this type of patient.Keywords: vitamin K antagonists, pain killers, interactions, INR
Procedia PDF Downloads 3001248 Efficacy and Safety of Sublingual Sufentanil for the Management of Acute Pain
Authors: Neil Singla, Derek Muse, Karen DiDonato, Pamela Palmer
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Introduction: Pain is the most common reason people visit emergency rooms. Studies indicate however, that Emergency Department (ED) physicians often do not provide adequate analgesia to their patients as a result of gender and age bias, opiophobia and insufficient knowledge of and formal training in acute pain management. Novel classes of analgesics have recently been introduced, but many patients suffer from acute pain in settings where the availability of intravenous (IV) access may be limited, so there remains a clinical need for rapid-acting, potent analgesics that do not require an invasive route of delivery. A sublingual sufentanil tablet (SST), dispensed using a single-dose applicator, is in development for treatment of moderate-to-severe acute pain in a medically-supervised setting. Objective: The primary objective of this study was to demonstrate the repeat-dose efficacy, safety and tolerability of sufentanil 20 mcg and 30 mcg sublingual tablets compared to placebo for the management of acute pain as determined by the time-weighted sum of pain intensity differences (SPID) to baseline over the 12-hour study period (SPID12). Key secondary efficacy variables included SPID over the first hour (SPID1), Total pain relief over the 12-hour study period (TOTPAR12), time to perceived pain relief (PR) and time to meaningful PR. Safety variables consisted of adverse events (AE), vital signs, oxygen saturation and early termination. Methods: In this Phase 2, double-blind, dose-finding study, an equal number of male and female patients were randomly assigned in a 2:2:1 ratio to SST 20 mcg, SS 30 mcg or placebo, respectively, following bunionectomy. Study drug was dosed as needed, but not more frequently than hourly. Rescue medication was available as needed. The primary endpoint was the Summed Pain Intensity Difference to baseline over 12h (SPIDI2). Safety was assessed by continuous oxygen saturation monitoring and adverse event reporting. Results: 101 patients (51 Male/50 Female) were randomized, 100 received study treatment (intent-to-treat [ITT] population), and 91 completed the study. Reasons for early discontinuation were lack of efficacy (6), adverse events (2) and drug-dosing error (1). Mean age was 42.5 years. For the ITT population, SST 30 mcg was superior to placebo (p=0.003) for the SPID12. SPID12 scores in the active groups were superior for both male (ANOVA overall p-value =0.038) and female (ANOVA overall p-value=0.005) patients. Statistically significant differences in favour of sublingual sufentanil were also observed between the SST 30mcg and placebo group for SPID1(p<0.001), TOTPAR12(p=0.002), time to perceived PR (p=0.023) and time to meaningful PR (p=0.010). Nausea, vomiting and somnolence were more frequent in the sufentanil groups but there were no significant differences between treatment arms for the proportion of patients who prematurely terminated due to AE or inadequate analgesia. Conclusions: Sufentanil tablets dispensed sublingually using a single-dose applicator is in development for treatment of patients with moderate-to-severe acute pain in a medically-supervised setting where immediate IV access is limited. When administered sublingually, sufentanil’s pharmacokinetic profile and non-invasive delivery makes it a useful alternative to IM or IV dosing.Keywords: acute pain, pain management, sublingual, sufentanil
Procedia PDF Downloads 3561247 Potassium Fertilization Improves Rice Yield in Aerobic Production System by Decreasing Panicle Sterility
Authors: Abdul Wakeel, Hafeez Ur Rehman, Muhammad Umair Mubarak
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Rice is the second most important staple food in Pakistan after wheat. It is not only a healthy food for the people of all age groups but also a source of foreign exchange for Pakistan. Instead of bright history for Basmati rice production, we are suffering from multiple problems reducing yield and quality as well. Rice lodging and water shortage for an-aerobic rice production system is among major glitches of it. Due to water shortage an-aerobic rice production system has to be supplemented or replaced by aerobic rice system. Aerobic rice system has been adopted for production of non-basmati rice in many parts of the world. Also for basmati rice, significant efforts have been made for aerobic rice production, however still has to be improved for effective recommendations. Among two major issues for aerobic rice, weed elimination has been solved to great extent by introducing suitable herbicides, however, low yield production due weak grains and panicle sterility is still elusive. It has been reported that potassium (K) has significant role to decrease panicle sterility in cereals. Potassium deficiency is obvious for rice under aerobic rice production system due to lack of K gradient coming with irrigation water and lowered indigenous K release from soils. Therefore it was hypothesized that K application under aerobic rice production system may improve the rice yield by decreasing panicle sterility. Results from pot and field experiments confirm that application of K fertilizer significantly increased the rice grain yield due to decreased panicle sterility and improving grain health. The quality of rice was also improved by K fertilization.Keywords: DSR, Basmati rice, aerobic, potassium
Procedia PDF Downloads 3931246 Origanum vulgare as a Possible Modulator of Testicular Endocrine Function in Mice
Authors: Eva Tvrdá, Barbora Babečková, Michal Ďuračka, Róbert Kirchner, Július Árvay
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This study was designed to assess the in vitro effects of Origanum vulgare L. (oregano) extract on the testicular steroidogenesis. We focused on identifying major biomolecules present in the oregano extract, as well as to investigate its in vitro impact on the secretion of cholesterol, testosterone, dehydroepiandrosterone and androstenedione by murine testicular fragments. The extract was subjected to high performance liquid chromatography (HPLC) which identified cyranosid, daidzein, thymol, rosmarinic and trans-caffeic acid among the predominant biochemical components of oregano. For the in vitro experiments, testicular fragments from 20 sexually mature Institute of Cancer Research (ICR) mice were incubated in the absence (control group) or presence of the oregano extract at selected concentrations (10, 100 and 1000 μg/mL) for 24 h. Cholesterol levels were quantified using photometry and the hormones were assessed by ELISA (Enzyme-Linked Immunosorbent Assay). Our data revealed that the release of cholesterol and androstenedione (but not dehydroepiandrosterone and testosterone) by the testicular fragments was significantly impacted by the oregano extract in a dose-dependent fashion. Supplementation of the extract resulted in a significant decline of cholesterol (P < 0.05 in case of 100 μg/mL; P < 0.01 with respect 100 μg/mL extract), as well as androstenedione (P < 0.01 with respect to 100 and 1000 μg/mL extract). Our results suggest that the biomolecules present in Origanum vulgare L. could exhibit a dose-dependent impact on the secretion of male steroids, playing a role in the regulation of testicular steroidogenesis.Keywords: mice, Origanum vulgare L., steroidogenesis, testes
Procedia PDF Downloads 1671245 The Relationship between Trace Elements in Groundwater Linked to a History of Volcanic Activity in La Pampa and Buenos Aires Provinces, Argentina
Authors: Maisarah Jaafar, Neil I. Ward
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Volcanic and geothermal activity can result in the release of arsenic (As), manganese (Mn), iron, selenium (Se), molybdenum (Mo) and uranium (U) into natural waters. Several studies have reported high levels of these elements in surface and groundwater in Argentina. The main focus has been on As associated with volcanic ash deposits. This study reports the trace element levels of groundwater from an agricultural region of south-eastern La Pampa and southern Buenos Aires provinces, Argentina which have reported high levels of human health problems (bone/teeth disorders, depression, arthritis, etc). Fifty-eight groundwater samples were collected from wells adjacent to Ruta 35 and an Agilent 7700x inductively coupled plasma mass spectrometer (ICP-MS) were used for total elemental analysis. Physicochemical analysis confirmed pH range of 7.05-8.84 and variable conductivity (988-3880 µS/cm) with total dissolved solid content of 502-1989 mg/l. The majority water samples are in an oxidizing environment (Eh= 45-146 mV). Total As levels ranged from (µg/l): 13.08 – 319.4 for La Pampa (LP) and 39.6 – 189.4 for Buenos Aires (BA); all above the WHO Guideline for Drinking Water, 10 µg/l As. Interestingly, Mo (LP: 1.85 – 85.39 µg/l; BA: 4.61– 55.55 µg/l;), Se (LP: 1.2 – 16.59 µg/l; BA: 0.3– 6.94 µg/l;) and U (LP: 1.85 – 85.39 µg/l; BA: 4.61– 55.55 µg/l;) levels are lower than reported values for northern La Pampa. Inter-elemental correlation displayed positive statistically significant between As-Mo, A-Se, As-U while negative statistically significant between As-Mn and As-Fe. This confirms that the source of the trace element is similar to that reported for other region of Argentina, namely volcanic ash deposition.Keywords: Argentina, groundwater, trace element, volcanic activity
Procedia PDF Downloads 3361244 Hepatoprotective Activity of Ethanolic Extract of Terminalia paniculata against Anti-Tubercular Drugs (ATT) Induced Hepatotoxicity in Wistar Albino Rats
Authors: Mohana Babu Amberkar, Meena Kumari K, Ravi, Arjun, Christopher Rockson
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The aim of this research is to evaluate the hepatoprotective activity of Terminalia paniculata (Tp) against ATT induced hepatic damage in rats.Three hepatotoxic ATT drugs Isoniazid + Rifampicin + Pyrazinamide, silymarin as standard hepatoprotective drug and 0.5% carboxymethylcellulose (CMC) as a control were used. Tp extract and silymarin were administered orally with ATT drugs for 90 days. Two doses 250 and 500 mg/kg of Tp extract, ATT drugs and silymarin were administered as suspensions with 0.5% CMC. ATT treated rats showed a significant increase in aspartate transaminase, alanine transaminase, alkaline phosphatase, lactate dehydrogenase, and lipid peroxides in the serum vs. control. Treatment of silymarin and Tp (250mg/kg) extract showed hepatoprotective activity against the hepatic damage by ATT. This was evident from significant reduction in serum liver enzymes levels, and also there was a significant increase in serum proteins, albumin and total liver tissue thiols as compared to the ATT treated groups. Tp was found to possess hepatoprotective property.Keywords: antitubercular drugs, hepatoprotective, liver enzymes, Terminalia paniculata
Procedia PDF Downloads 4411243 Presence of High Concentrations of Toxic Metals from the Collected Soil Samples Due to Excessive E-Waste Burning in the Various Areas of Moradabad City, U.P India
Authors: Aprajita Singh, Anamika Tripathi, Surya P. Dwivedi
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Moradabad is a small town in the Northern area of Uttar Pradesh, India. It is situated on the bank of river Ramganga which is also known as ‘Brass City of India’. There is eventually increase in the environmental pollution due to uncontrolled and inappropriate e-waste burning (recycling) activities which have been reported in many areas of Moradabad. In this paper, analysis of toxic heavy metals, causing pollution to the surrounding environment released from the e-waste burning and much other recycling process. All major e-waste burning sites are situated on the banks of the river which is burned in open environmental conditions. Soil samples were collected from seven (n=3) different sites including control site, after digestion of soil samples using triacid mixture, analysis of different toxic metals (Pb, Ar, Hg, Cd, Cr, Cu, Zn, Fe, and Ni) has been carried out with the help of instrument ICP-AAS. After the study, the outcome is that the soil of those areas contains a relatively high level of the toxic metals in order of Cu>Fe>Pb>Cd>Cr>Zn>Ar>Hg. The concentration of Cd, Pb, Cr, Ar and Zn (the majority of samples experimentally proved) exceeded the maximum standard level of WHO. Sequentially this study showed that uncontrolled e-waste processing operations caused serious pollution to local soil and release of toxic metals in the environment is also causing adverse effect on the health of people living in the nearby areas making them more prone to various harmful diseases.Keywords: brass city, environment pollution, e-waste, toxic heavy metals
Procedia PDF Downloads 3001242 Synthesis and Characterization of Carboxymethyl Cellulose-Chitosan Based Composite Hydrogels for Biomedical and Non-Biomedical Applications
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Hydrogels have attracted much academic and industrial attention due to their unique properties and potential biomedical and non-biomedical applications. Limitations on extending their applications have resulted from the synthesis of hydrogels using toxic materials and complex irreproducible processing techniques. In order to promote environmental sustainability, hydrogel efficiency, and wider application, this study focused on the synthesis of composite hydrogels matrices from an edible non-toxic crosslinker-citric acid (CA) using a simple low energy processing method based on carboxymethyl cellulose (CMC) and chitosan (CSN) natural polymers. Composite hydrogels were developed by chemical crosslinking. The results demonstrated that CMC:2CSN:CA exhibited good performance properties and super-absorbency 21× its original weight. This makes it promising for biomedical applications such as chronic wound healing and regeneration, next generation skin substitute, in situ bone regeneration and cell delivery. On the other hand, CMC:CSN:CA exhibited durable well-structured internal network with minimum swelling degrees, water absorbency, excellent gel fraction, and infra-red reflectance. These properties make it a suitable composite hydrogel matrix for warming effect and controlled and efficient release of loaded materials. CMC:2CSN:CA and CMC:CSN:CA composite hydrogels developed also exhibited excellent chemical, morphological, and thermal properties.Keywords: citric acid, fumaric acid, tartaric acid, zinc nitrate hexahydrate
Procedia PDF Downloads 1511241 Functional Expression and Characterization of a Novel Indigenous Endo-Beta 1,4- Glucanase from Apis mellifera
Authors: Amtul Jamil Sami
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Apis mellifera is an insect of immense economic importance lives on rich carbohydrate diet including cellulose, nectar, honey and pollen. The carbohydrate metabolism in A mellifera has not been understood fully, as there are no data available, on the functional expression of cellulase gene. The cellulose hydrolyzing enzyme is required for the digestion of pollen cellulose wall, to release the important nutrients (amino acids, minerals, vitamins etc.) from the pollen. A dissection of Apis genome had revealed that there is one gene present for the expression of endo-beta-1,4-glucanase, for cellulose hydrolysis. In the presented work, functional expression of endo-beta-1,4 glucanase gene is reported. Total soluble proteins of the honey bee were isolated and were tested cellulose hydrolyzing enzyme activity, using carboxy-methyl cellulose, as a substrate. A mellifera proteins were able to hydrolyze carboxy-methyl cellulose, confirming its endo- type mode of action. Endo beta-1,4 glucanase enzyme was only present in the gut tissues, no activity was detected in the salivary glands. The pH optima of the enzyme were in the acidic pH range of 4-5-5-0, indicating its metabolic role in the acidic stomach of A mellifera. The reported enzyme is unique, as endo-beta- 1,4 glucanase was able to generate non reducing sugar, as an end product. The results presented, are supportive to the information that the honey bee is capable of producing its novel endo-beta-1,4 glucanase. Further it could be helpful, in understanding, the carbohydrate metabolism in A mellifera.Keywords: honey bees, Endo-beta 1, 4- glucanase, Apis mellifera, functional expression
Procedia PDF Downloads 4031240 Experimental Characterization and Modelling of Microfluidic Radial Diffusers
Authors: Eric Chappel, Dimitry Dumont-Fillon, Hugo Musard, Harald van Lintel
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A microfluidic radial diffuser typically comprises a hole in a membrane, a small gap and pillar centred with the hole. The fluid is forced to flow radially in this gap between the membrane and the pillar. Such diffusers are notably used to form flow control valves, wherein several holes are machined into a flexible membrane progressively deflecting against pillars as the pressure increases. The fluidic modelling of such diffuser is made difficult by the presence of a transition region between the hole and the diffuser itself. An experimental investigation has been conducted using SOI wafers to form membranes with only one centred hole and Pyrex wafers for the substrate and pillars, both wafers being anodically bonded after alignment. A simple fluidic model accounting for the specific geometry of the diffuser is proposed and compared to experimental results. A good match is obtained, for Reynolds number in the range 0.5 to 35 using the analytical formula of a radial diffuser in the laminar regime with an effective inner radius that is 40% smaller than the real radius, in order to simulate correctly the flow constriction at the entrance of the diffuser.Keywords: radial diffuser, flow control valve, numerical modelling, drug delivery
Procedia PDF Downloads 278