Search results for: drug stability

Authors: Elragig Aiman, Dreiwi Hanan, Townley Stuart, Elmabrook Idriss

Abstract:

In this paper, we reconsider the analysis of the Oregonator model. We highlight an error in this analysis which leads to an incorrect depiction of the parameter region in which diffusion driven instability is possible. We believe that the cause of the oversight is the complexity of stability analyses based on eigenvalues and the dependence on parameters of matrix minors appearing in stability calculations. We regenerate the parameter space where Turing patterns can be seen, and we use the common Lyapunov function (CLF) approach, which is numerically reliable, to further confirm the dependence of the results on diffusion coefficients intensities.

Keywords: diffusion driven instability, common Lyapunov function (CLF), turing pattern, positive-definite matrix

Procedia PDF Downloads 353

Authors: Hrvoje Simovic

Abstract:

Paper analyses the key problems of fiscal sustainability in Croatia. To point out key challenges of fiscal sustainability, the public debt sustainability is analyzed using standard indicators of fiscal stability, accompanied with the identification of regime changes approach in the public debt trajectory using switching regression approach. The analysis is conducted for the period from 2001 to 2016. Results show huge vulnerability in recession period (2009-14), so key challenges in current fiscal policy and public debt management are recognized in maturity prolongation, interest rates trends, and credit rating expectations.

Keywords: fiscal sustainability, public debt, Croatia, budget deficit

Procedia PDF Downloads 255

Authors: Simone Galati, Adriano Troia

Abstract:

Ultrasound (US) is widely used in medical field for a variety diagnostic techniques but, in recent years, it has also been creating great interest for therapeutic aims. Regarding drug delivery, the use of US as an activation source provides better spatial delivery confinement and limits the undesired side effects. However, at present there is no complete characterization at a fundamental level of the different signals produced by sono-activated nanocarriers. Therefore, the aim of this study is to obtain a metrological characterization of the cavitation phenomena induced by US through three parallel investigation approaches. US was focused into a channel of a customized phantom in which a solution with oxygen-loaded nanodroplets (OLNDs) was led to flow and the cavitation activity was monitored. Both quantitative and qualitative real-time analysis were performed giving information about the dynamics of bubble formation, oscillation and final implosion with respect to the working acoustic pressure and the type of nanodroplets, compared with pure water. From this analysis a possible interpretation of the observed results is proposed.

Keywords: cavitation, drug delivery, nanodroplets, ultra-sound

Procedia PDF Downloads 102

Authors: M. Maciejewska, F. Walkiewicz

Abstract:

The aim of this work was to study the activity of several novel benzalkonium and alkylammonium and alkylimidazolium ionic liquids with 2-mercaptobenzothiazolate for use as accelerators in the sulphur vulcanisation of butadiene-styrene elastomer (SBR). The application of novel ionic liquids allowed for the elimination of N-cyclohexyl-2-benzothiazolesulfenamide from SBR compounds and for the considerable reduction of the amount of 2-mercaptobenzothiazole present in rubber products, which is favourable because, it is an allergenic agent. Synthesised salts could be used alternatively to standard accelerators in the vulcanisation of SBR, without any detrimental effects on the vulcanisation process, the physical properties or the thermal stability of the obtained vulcanisates. Ionic liquids increased the crosslink density of the vulcanisates and improved their thermal stability.

Keywords: ionic liquids, mechanical properties, styrene-butadiene rubber, vulcanisation

Procedia PDF Downloads 307

Authors: Raouf Alizadeh, Kadijeh Hemmati

Abstract:

The aim of this study is to synthesize several series of hydrogels from combination of a natural based polymer (Quince seed mucilage QSD), a synthetic copolymer contained methoxy poly ethylene glycol -polycaprolactone (mPEG-PCL) in the presence of different amount of multi-walled carbon nanotube (f-MWNT). Mono epoxide functionalized mPEG (mP EG-EP) was synthesized and reacted with sodium azide in the presence of NH4Cl to afford mPEG- N3(-OH). Then ring opening polymerization (ROP) of ε–caprolactone (CL) in the presence of mPEG- N3(-OH) as initiator and Sn(Oct)2 as catalyst led to preparation of mPEG-PCL- N3(-OH ) which was grafted onto propagylated f-MWNT by the click reaction to obtain mPEG-PCL- f-MWNT (-OH ). In the presence of mPEG- N3(-Br) and mixture of NHS/DCC/ QSD, hybrid hydrogels were successfully synthesized. The copolymers and hydrogels were characterized using different techniques such as, scanning electron microscope (SEM) and thermogravimetric analysis (TGA). The gel content of hydrogels showed dependence on the weight ratio of QSD:mPEG-PCL:f-MWNT. The swelling behavior of the prepared hydrogels was also studied under variation of pH, immersion time, and temperature. According to the results, the swelling behavior of the prepared hydrogels showed significant dependence in the gel content, pH, immersion time and temperature. The highest swelling was observed at room temperature, in 60 min and at pH 8. The loading and in-vitro release of quercetin as a model drug were investigated at pH of 2.2 and 7.4, and the results showed that release rate at pH 7.4 was faster than that at pH 2.2. The total loading and release showed dependence on the network structure of hydrogels and were in the range of 65- 91%. In addition, the cytotoxicity and release kinetics of the prepared hydrogels were also investigated.

Keywords: antioxidant, drug delivery, Quince Seed Mucilage(QSD), swelling behavior

Procedia PDF Downloads 311

Authors: Asma Ansari, Afsheen Aman, Shah Ali Ul Qader

Abstract:

In the past few years, numerous concerns have been raised against increased bacterial resistance towards effective drugs and become a debated issue all over the world. With the emergence of drug resistant pathogens, the interaction of natural antimicrobial compounds and antibacterial nanoparticles has emerged as a potential candidate for combating infectious diseases. Microbial diversity in the biome provides an opportunity to screen new species which are capable of producing large number of antimicrobial compounds. Among these antimicrobial compounds, bacteriocins are highly specific and efficient antagonists. A combination of bacteriocin along with nanoparticles could prove to be more potent due to broadened antibacterial spectrum with possibly lower doses. In the current study, silver nanoparticles were synthesized through biological reduction using various isolated bacterial, fungal and yeast strains. Spectroscopy and scanning electron microscopy (SEM) was performed for the confirmation of nanoparticles. Bacteriocin was characterized and purified to homogeneity through gel permeation chromatography. The estimated molecular weight of bacteriocin was 10 kDa. Amino acid analysis and N-terminal sequencing revealed the novelty of the protein. Then antibacterial potential of silver nanoparticles and broad inhibitory spectrum bacteriocin was determined through agar well diffusion assay. These synthesized bacteriocin-Nanoparticles exhibit a good potential for clinical applications as compared to bacteriocin alone. This combination of bacteriocin with nanoparticles will be used as a new sort of biocide in the field of nano-proteomics. The advancement of nanoparticles-mediated drug delivery system will open a new age for rapid eradication of pathogens from biological systems.

Keywords: BAC-IB17, multidrug resistance, purification, silver nanoparticles

Procedia PDF Downloads 487

Authors: Hyuk Sang Yoo, Young Ju Son, Wei Mao, Myung Gu Kang, Sol Lee

Abstract:

Biomedical applications of electrospun nanofibrous meshes have been received tremendous attentions because of their unique structures and versatilities as biomaterials. Incorporation of growth factors in fibrous meshes can be performed by surface-modification and encapsulation. Those growth factors stimulate differentiation and proliferation of specific types of cells and thus lead tissue regenerations of specific cell types. Topographical cues of electrospun nanofibrous meshes also increase differentiation of specific cell types according to alignments of fibrous structures. Wound healing treatments of diabetic ulcers were performed using nanofibrous meshes encapsulating multiple growth factors. Aligned nanofibrous meshes and those with random configuration were compared for differentiating mesenchymal stem cells into neuronal cells. Thus, nanofibrous meshes can be applied to drug delivery carriers and matrix for promoting cellular proliferation.

Keywords: nanofiber, tissue, mesh, drug

Procedia PDF Downloads 335

Authors: Vanlounni Sibounheuang, Wanarat Anusornsangiam, Pattarin Kittiboonyakun, Chanthanom Manithip

Abstract:

In worldwide, one of the most common use of oral anticoagulant is warfarin. Its margin between therapeutic inhibition of clot formation and bleeding complications is narrow. Mahosot Hospital, warfarin clinic had not been established yet. The descriptive study was conducted by investigating drug-related problems of outpatients using warfarin, the value of the international normalized ratio (INR) higher than normal ranges (25.40 % of the total 272 outpatients) were mostly identified at Lao-Luxembourg Heart Centre, Mahosot Hospital, Lao PDR. This result led to the present study conducting qualitative interviews in order to help establish a warfarin clinic at Mahosot Hospital for the better outcomes of patients using warfarin. The purpose of this study was to explore perspectives of healthcare professional providing services for outpatients using warfarin. The face to face, in-depth interviews were undertaken among nine healthcare professionals (doctor=3, nurse=3, pharmacist=3) working at out-patient clinic, Lao-Luxembourg Heart Centre, Mahosot Hospital, Lao PDR. The interview guides were developed, and they were validated by the experts in the fields of qualitative research. Each interview lasted approximately 20 minutes. Three major themes emerged; healthcare professional’s experiences of current practice problems with warfarin therapy, healthcare professionals’ views of medical problems related to patients using warfarin, and healthcare professionals’ perspectives on ways of service improvement. All healthcare professionals had the same views that it’s difficult to achieve INR goal for individual patients because of some important patient barriers especially lack of knowledge about to use warfarin properly and safety, patients not regularly follow-up due to problems with transportations and financial support. Doctors and nurses agreed to have a pharmacist running a routine warfarin clinic and provided counselling to individual patients on the following points: how to take drug properly and safety, drug-drug and food-drug interactions, common side effects and how to manage them, lifestyle modifications. From the interviews, some important components of the establishment of a warfarin clinic included financial support, increased human resources, improved the system of keeping patients’ medical records, short course training for pharmacists. This study indicated the acceptance of healthcare professionals on the important roles of pharmacists and the feasibility of setting up warfarin clinic by working together with the multidisciplinary health care team in order to help improve health outcomes of patients using warfarin at Mahosot Hospital, Lao PDR.

Keywords: perspectives, healthcare professional, warfarin therapy, Mahosot Hospital

Procedia PDF Downloads 96

Authors: Ali Kargar, Kamyar Mansour

Abstract:

In this paper, experimental results of using hot wire anemometer and smoke visualization are presented. The results obtained on the hot wire anemometer for critical Reynolds number and transitional Reynolds number are compared by previous results. Excellent agreement is found for the transitional Reynolds number. The results for the transitional Reynolds number are also compared by previous linear stability results. The results of the smoke visualization clearly show the cross flow vortices which arise in the transition process from a laminar to a turbulent flow. A non-zero angle of attack is also considered. We compare our results by linear stability theory which was done by Garret et. Al (2007). We just emphasis, Also the visualization and hot wire anemometer results have been compared graphically. The goal in this paper is to check reliability of using hot wire anemometer and smoke visualization in transition problems and check reliability of linear stability theory for this case and compare our results with some trusty experimental works.

Keywords: transitional reynolds number, wind tunnel, rotating cone, smoke visualization

Procedia PDF Downloads 295

Authors: T. G. Kassem, A. K. Adunchezor, J. P. Chollom

Abstract:

This paper describes a mathematical model developed to predict the dynamics of Hepatitis B virus (HBV) infection and to evaluate the potential impact of vaccination and treatment on its dynamics. We used a compartmental model expressed by a set of differential equations based on the characteristic of HBV transmission. With these, we find the threshold quantity R0, then find the local asymptotic stability of disease free equilibrium and endemic equilibrium. Furthermore, we find the global stability of the disease free and endemic equilibrium.

Keywords: hepatitis B virus, epidemiology, vaccination, mathematical model

Procedia PDF Downloads 315

Authors: Amit Singla, Amit Chauhan

Abstract:

The non-circular journal bearings provide better thermal stability and lesser oil-film temperature rise as compared to circular journal bearings. Experimentation on simultaneous measurement of pressure and temperature of lubricated oil-film along the profile of the bearing will help the designer to design journal bearings. In this paper, pressure and temperature of oil-film along orthogonally displaced non-circular journal bearing have been measured on a designed journal bearing test rig. The orthogonal non-circular journal bearing has been fabricated by displacing two circular halves away from the centers in the orthogonal direction. The data acquisition for oil film pressure and temperature has been carried out at journal speed=3000 rpm and by increasing the static radial load from 500 N to 2000 N in steps of 500 N using three different grades of oil (ISOVG 32, 68, and 150) named as oil-1, oil-2, and oil-3 respectively. The results show that the oil-film pressure and temperature increases with increase in radial load and change of lubricating oil towards increasing viscosity. Further, two lobes in the pressure and temperature profiles have been obtained which accounts for better thermal stability as it reduces cavitation zone inside the bearing.

Keywords: cavitation, non-circular journal bearing, orthogonally displaced, thermal stability

Procedia PDF Downloads 346

Authors: Roslinda Nazar, Amin Noor, Khamisah Jafar, Ioan Pop

Abstract:

In this paper, the steady laminar three-dimensional boundary layer flow and heat transfer of a copper (Cu)-water nanofluid in the vicinity of a permeable shrinking flat surface in an otherwise quiescent fluid is studied. The nanofluid mathematical model in which the effect of the nanoparticle volume fraction is taken into account is considered. The governing nonlinear partial differential equations are transformed into a system of nonlinear ordinary differential equations using a similarity transformation which is then solved numerically using the function bvp4c from Matlab. Dual solutions (upper and lower branch solutions) are found for the similarity boundary layer equations for a certain range of the suction parameter. A stability analysis has been performed to show which branch solutions are stable and physically realizable. The numerical results for the skin friction coefficient and the local Nusselt number as well as the velocity and temperature profiles are obtained, presented and discussed in detail for a range of various governing parameters.

Keywords: heat transfer, nanofluid, shrinking surface, stability analysis, three-dimensional flow

Procedia PDF Downloads 280

Authors: Arindam Pramanik, Parimal Karmakar

Abstract:

We have explored the synergistic anti-cancer activity of copper ion and acetylacetone complex containing 1,3 diketone group (like curcumin) in metallorganic compound “Copper acetylacetonate” (CuAA). The cytotoxicity mechanism of CuAA complex was evaluated on various cancer cell lines in vitro. Among these, reactive oxygen species (ROS), glutathione level (GSH) in the cell was found to increase. Further mitochondrial membrane damage was observed. The fate of cell death was found to be induced by apoptosis. For application purpose, we have developed a novel biodegradable, non-toxic polymer-based nanoparticle which has hydrophobically modified core for loading of the CuAA. Folic acid is conjugated on the surface of the polymer (chitosan) nanoparticle for targeting to cancer cells for minimizing toxicity to normal cells in-vivo. Thus, this novel drug CuAA has an efficient anticancer activity which has been targeted specifically to cancer cells through polymer nanoparticle.

Keywords: anticancer, apoptosis, copper nanoparticle, targeted drug delivery

Procedia PDF Downloads 477

Authors: Chukwuma Anya, Mekwa Eme

Abstract:

Foundation is popularly defined as the lowest load-bearing part of a building, typically below the ground level. It serves as an underlying base which acts as the principle on which every building stands. There are various types of foundations in practice, which includes the strip, pile, pad, and raft foundations, and each of these have their various applications in building construction. However due to lack of professional knowledge, cost, or scheduled time frame to complete a certain project, some of these foundation types are some times neglected or used interchangeably, resulting to misuse or abuse of the building materials man, power, and some times altering the stability, balance and aesthetics of most buildings. This research work is aimed at educating the academic community on the proper application of the various foundation types to suit different environments such as the rain forest, desert, swampy area, rocky area etc. A proper application of the foundation will ensure the safety of the building from acid grounds, damping and weakening of foundation, even building settlement and stability. In addition to those, it will improve aesthetics, maintain cost effectiveness both construction cost and maintenance cost. Finally it will ensure the safety of the building and its inhabitants. At the end of this research work we will be able to differentiate the various foundation types and there proper application in the design and construction of buildings.

Keywords: foundation, application, stability, aesthetics

Procedia PDF Downloads 68

Authors: Patompong Satapornpong, Therdpong Tempark, Pawinee Rerknimitr, Jettanong Klaewsongkram, Chonlaphat Sukasem

Abstract:

Dapsone (4, 4’-diaminodiphenyl sulfone, DDS) is broadly used for the treatment of inflammatory diseases and infections such as; leprosy, Pneumocystis jiroveci pneumonia in patients with HIV infection, neutrophilic dermatoses, dermatitis herpetiformis and autoimmune bullous disease. The severe cutaneous adverse drug reactions (SCARs) including, Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN) and drug reaction with eosinophilia and systemic symptoms (DRESS) are rare but severe life-threatening adverse drug reactions. Dapsone is one of many culprit drugs induced SJS, TEN and DRESS. Notwithstanding, to our knowledge, there are no studies of the association of HLA class I alleles and dapsone-induced SCARs in non-leprosy Thai patients. This investigation was a prospective cohort study, which performed in a total of 45 non-leprosy patients. Fifteen patients of dapsone-induced SCARs were classified as following the RegiSCAR criteria, and 30 dapsone-tolerant controls were exposed to dapsone more than 6 months without any evidence of cutaneous reactions. The genotyping of HLA-A, -B and –C were performed using sequence-specific oligonucleotides (PCR-SSOs). The Ethics Committee of Ramathibodi hospital, Mahidol University, approved this study. Among all HLA class I alleles, HLA-A*24:07, HLA-B*13:01, HLA-B*15:02, HLA-C*03:04 and HLA-C*03:09 were significantly associated with dapsone-induced SCARs (OR = 10.55, 95% CI = 1.06 – 105.04, p = 0.0360; OR = 56.00, 95% CI = 8.27 – 379.22, p = 0.0001; OR = 7.00, 95% CI = 1.17 – 42.00, p = 0.0322; OR = 6.00, 95% CI = 1.24 – 29.07, p = 0.0425 and OR = 17.08, 95% CI = 0.82 – 355.45, p = 0.0321, respectively). Furthermore, HLA-B*13:01 allele had strong association with dapsone-induced SJS-TEN and DRESS when compared with dapsone-tolerant controls (OR = 42.00, 95% CI = 2.88 – 612.31, p = 0.0064 and OR = 63.00, 95% CI = 7.72 – 513.94 and p = 0.0001, respectively). Consequently, HLA-B*13:01 might serve as a pharmacogenetic marker for screening before initiating the therapy with dapsone for prevention of dapsone-induced SCARs.

Keywords: dapsone-induced SCARs, HLA-B*13:01, HLA class I alleles, severe cutaneous adverse reactions, Thai

Procedia PDF Downloads 230

Authors: A. Hadadi, M. Abdollahi, A. Dustmohammadi

Abstract:

The growing use of DGs in distribution networks provide many advantages and also cause new problems which should be anticipated and be solved with appropriate solutions. One of the problems is transient voltage drop and short circuit in the electrical network, in the presence of distributed generation - which can lead to instability. The appearance of the short circuit will cause loss of generator synchronism, even though if it would be able to recover synchronizing mode after removing faulty generator, it will be stable. In order to increase system reliability and generator lifetime, some strategies should be planned to apply even in some situations which a fault prevent generators from separation. In this paper, one fault current limiter is installed due to prevent DGs separation from the grid when fault occurs. Furthermore, an innovative objective function is applied to determine the impedance optimal amount of fault current limiter in order to improve transient stability of distributed generation. Fault current limiter can prevent generator rotor's sudden acceleration after fault occurrence and thereby improve the network transient stability by reducing the current flow in a fast and effective manner. In fact, by applying created impedance by fault current limiter when a short circuit happens on the path of current injection DG to the fault location, the critical fault clearing time improve remarkably. Therefore, protective relay has more time to clear fault and isolate the fault zone without any instability. Finally, different transient scenarios of connection plan sustainability of small scale synchronous generators to the distribution network are presented.

Keywords: critical clearing time, fault current limiter, synchronous generator, transient stability, transient states

Procedia PDF Downloads 191

Authors: Archana G. Lamdande, Shyam R. Garud, K. S. M. S. Raghavarao

Abstract:

Coconut has two edible parts, that is, a white kernel (solid endosperm) and coconut water (liquid endosperm). The white kernel is generally used in fresh or dried form for culinary purposes. Coconut testa, is the brown skin, covering the coconut kernel. It is removed by paring of wet coconut and obtained as a by-product in coconut processing industries during the production of products such as desiccated coconut, coconut milk, whole coconut milk powder and virgin coconut oil. At present, it is used as animal feed component after drying and recovering the residual oil (by expelling). Experiments were carried out on expelling of coconut milk for shredded coconut with and without testa removal, in order to explore the possibility of increasing the milk yield and value addition in terms of increased polyphenol content. The color characteristics of coconut milk obtained from the grating without removal of testa were observed to be L* 82.79, a* 0.0125, b* 6.245, while that obtained from grating with removal of testa were L* 83.24, a* -0.7925, b* 3.1. A significant increase was observed in total phenol content of coconut milk obtained from the grating with testa (833.8 µl/ml) when compared to that from without testa (521.3 µl/ml). However, significant difference was not observed in protein content of coconut milk obtained from the grating with and without testa (4.9 and 5.0% w/w, respectively). Coconut milk obtained from grating without removal of testa showed higher milk yield (62% w/w) when compared to that obtained from grating with removal of testa (60% w/w). The fat content in coconut milk was observed to be 32% (w/w), and it is unstable due to such a high fat content. Therefore, several experiments were carried out for examining its stability by adjusting the fat content at different levels (32, 28, 24, and 20% w/w). It was found that the coconut milk was more stable with a fat content of 24 % (w/w). Homogenization and ultrasonication and their combinations were used for exploring the possibility of increasing the stability of coconut milk. The microscopic study was carried out for analyzing the size of fat globules and the degree of their uniform distribution.

Keywords: coconut milk, homogenization, stability, testa, ultrasonication

Procedia PDF Downloads 308

Authors: Vladimir Hovhannisyan, Chen Yuan Dong

Abstract:

Recently nanoparticles (NPs) have been introduced in biomedicine as effective agents for cancer-targeted drug delivery and noninvasive tissue imaging. The most important requirements to these agents are their non-toxicity, biocompatibility and stability. In view of these criteria, the zeolite (ZL) nanoparticles (NPs) may be considered as perfect candidates for biomedical applications. ZLs are crystalline aluminosilicates consisting of oxygen-sharing SiO4 and AlO4 tetrahedral groups united by common vertices in three-dimensional framework and containing pores with diameters from 0.3 to 1.2 nm. Generally, the behavior and physical properties of ZLs are studied by SEM, X-ray spectroscopy, and AFM, whereas optical spectroscopic and microscopic approaches are not effective enough, because of strong scattering in common ZL bulk materials and powders. The light scattering can be reduced by using of ZL NPs. ZL NPs have large external surface area, high dispersibility in both aqueous and organic solutions, high photo- and thermal stability, and exceptional ability to adsorb various molecules and atoms in their nanopores. In this report, using multiphoton microscopy and nonlinear spectroscopy, we investigate nonlinear optical properties of clinoptilolite type of ZL micro- and nanoparticles with average diameters of 2200 nm and 240 nm, correspondingly. Multiphoton imaging is achieved using a laser scanning microscope system (LSM 510 META, Zeiss, Germany) coupled to a femtosecond titanium:sapphire laser (repetition rate- 80 MHz, pulse duration-120 fs, radiation wavelength- 720-820 nm) (Tsunami, Spectra-Physics, CA). Two Zeiss, Plan-Neofluar objectives (air immersion 20×∕NA 0.5 and water immersion 40×∕NA 1.2) are used for imaging. For the detection of the nonlinear response, we use two detection channels with 380-400 nm and 435-700 nm spectral bandwidths. We demonstrate that ZL micro- and nanoparticles can produce nonlinear optical response under the near-infrared femtosecond laser excitation. The interaction of hypericine, chlorin e6 and other dyes with ZL NPs and their photodynamic activity is investigated. Particularly, multiphoton imaging shows that individual ZL NPs particles adsorb Zn-tetraporphyrin molecules, but do not adsorb fluorescein molecules. In addition, nonlinear spectral properties of ZL NPs in native biotissues are studied. Nonlinear microscopy and spectroscopy may open new perspectives in the research and application of ZL NP in biomedicine, and the results may help to introduce novel approaches into the clinical environment.

Keywords: multiphoton microscopy, nanoparticles, nonlinear optics, zeolite

Procedia PDF Downloads 407

Authors: Nani Mchedlishvili, Nino Omiadze, Marine Abutidze, Jose Neptuno Rodriguez-Lopez, Tinatin Sadunishvili, Nikoloz Pruidze, Giorgi Kvesitadze

Abstract:

Recently, there is an increased interest in the development of food natural colorants as alternatives to synthetic dyes because of both legislative action and consumer concern. Betalains are widely used in the food industry as an alternative of synthetic colorants. The interest of betalains are caused not only by their coloring effect but also by their beneficial properties. The aim of the work was to study of stability of crude and purified red pigments of pokeberry (Phytolacca america L.). The pokeberry fruit juice was filtrated and concentrated by rotary vacuum evaporator up to 25% and the concentrated juice was passed through the Sepadex-25(fine) column (20×1.1 cm). From the column the pigment elution rate was 18 ml/hr. 1.5ml fractions of pigment were collected. In the fractions the coloring substances were determined using CuS04 x 7 H2O as a standard. From the Sephadex G-25 column only one fraction of the betalain red pigment was eluted with the absorption maximum at 538 nm. The degree of pigment purification was 1.6 and pigment yield from the column was 15 %. It was shown that thermostability of pokeberry fruit red pigment was significantly decreased after the purification. For example, during incubation at 100C for 10 min crude pigment retained 98 % of its color while under the same conditions only 72% of the color of purified pigment was retained. The purified pigment was found to be characterized by less storage stability too. The storage of the initial crude juice and the pigment fraction obtained after the gelfiltration for 10 days at 4°C showed the lost of color by 29 and 74 % respectively. From the results obtained, it can be concluded that during the gelfiltration the pokeberry fruit red pigment gets separated from such substances that cause its stabilization in the crude juice.

Keywords: betalains, gelfiltration, pokeberry fruit, stability

Procedia PDF Downloads 284

Authors: S. Raja Mohamed, M. H Shwehdi, D. Devaraj

Abstract:

This paper is to present and discuss the new planned 380 kV transmission line performance under steady and transient states. Dynamic modeling and analysis of such inter-tie, which is, proposed to transfer energy from west to south and vice versa will be demonstrated and discussed. The west-central-south inter-tie links Al-Aula-Zaba-Tabuk-Tubajal-Jawf-Hail. It is essential to investigate the transient over-voltage to assure steady and stable transmission over such inter-tie. Saudi Electricity Company (SEC) has been improving its grid to make the whole country as an interconnected system. Already east, central and west were interconnected, yet mostly each is fed with its local generation. The SEC is planning to establish many inter-ties to strengthen the transient stability of its grid. The paper studies one of the important links of 380 kV, 220 km between Tabouk and Tubarjal, which is a step towards connecting the West with the South region. Modeling and analysis using some softwares will be utilized under different scenarios. Adoption of methods to stabilize and increase its power transmission are also discussed. Improvement of power system transients has been controlled by FACTS elements such the Static Var Compensators (SVC) receiving a wide interest since many technical studies have proven their effects on damping system oscillations and stability enhancement. Illustrations of the transient at each main generating or load bus will be checked in all inter-tie links. A brief review of possible means to solve the transient over-voltage problem using different FACTS element modeling will be discussed.

Keywords: transient stability, static var compensator, central-west interconnected system, damping controller, Saudi Electricity Company

Procedia PDF Downloads 600

Authors: Sudhir Kumar, V. R. Sinha

Abstract:

Water in oil topical microemulsions of 5-FU were developed and optimized using face centered central composite design. Topical w/o microemulsion of 5-FU were prepared using sorbitan monooleate (Span 80), polysorbate 80 (Tween 80), with different oils such as oleic acid (OA), triacetin (TA), and isopropyl myristate (IPM). The ternary phase diagrams designated the microemulsion region and face centered central composite design helped in determining the effects of selected variables viz. type of oil, smix ratio and water concentration on responses like drug content, globule size and viscosity of microemulsions. The CCD design exhibited that the factors have statistically significant effects (p<0.01) on the selected responses. The actual responses showed excellent agreement with the predicted values as suggested by the CCD with lower residual standard error. Similarly, the optimized values were found within the range as predicted by the model. Furthermore, other characteristics of microemulsions like pH, conductivity were investigated. For the optimized microemulsion batch, ex-vivo skin flux, skin irritation and retention studies were performed and compared with marketed 5-FU formulation. In ex vivo skin permeation studies, higher skin retention of drug and minimal flux was achieved for optimized microemulsion batch then the marketed cream. Results confirmed the actual responses to be in agreement with predicted ones with least residual standard errors. Controlled release of drug was achieved for the optimized batch with higher skin retention of 5-FU, which can further be utilized for the treatment of many dermatological disorders.

Keywords: 5-FU, central composite design, microemulsion, ternanry phase diagram

Procedia PDF Downloads 473

Authors: J. Ritonja, R. Brezovnik, M. Petrun, B. Polajžer

Abstract:

Many modern synchronous generators in power systems are extremely weakly damped. The reasons are cost optimization of the machine building and introduction of the additional control equipment into power systems. Oscillations of the synchronous generators and related stability problems of the power systems are harmful and can lead to failures in operation and to damages. The only useful solution to increase damping of the unwanted oscillations represents the implementation of the power system stabilizers. Power system stabilizers generate the additional control signal which changes synchronous generator field excitation voltage. Modern power system stabilizers are integrated into static excitation systems of the synchronous generators. Available commercial power system stabilizers are based on linear control theory. Due to the nonlinear dynamics of the synchronous generator, current stabilizers do not assure optimal damping of the synchronous generator’s oscillations in the entire operating range. For that reason the use of the robust power system stabilizers which are convenient for the entire operating range is reasonable. There are numerous robust techniques applicable for the power system stabilizers. In this paper the use of sliding mode control for synchronous generator stability improvement is studied. On the basis of the sliding mode theory, the robust power system stabilizer was developed. The main advantages of the sliding mode controller are simple realization of the control algorithm, robustness to parameter variations and elimination of disturbances. The advantage of the proposed sliding mode controller against conventional linear controller was tested for damping of the synchronous generator oscillations in the entire operating range. Obtained results show the improved damping in the entire operating range of the synchronous generator and the increase of the power system stability. The proposed study contributes to the progress in the development of the advanced stabilizer, which will replace conventional linear stabilizers and improve damping of the synchronous generators.

Keywords: control theory, power system stabilizer, robust control, sliding mode control, stability, synchronous generator

Procedia PDF Downloads 217

Authors: Asher John Mohan, Krishna K. L.

Abstract:

Objectives: (1) To assess the extent of memory impairment induced by Phenytoin (PHT) at normal and reduced dose on temporal lobe epileptic mice. (2) To evaluate the protective effect of Levetiracetam (LEV) on aggravation of memory impairment in temporal lobe epileptic mice by PHT. Materials and Methods: Albino mice of either sex (n=36) were used for the study for a period of 64 days. Convulsions were induced by intraperitoneal administration of pilocarpine 280 mg/kg on every 6th day. Radial arm maze (RAM) was employed to evaluate the memory impairment activity on every 7th day. The anticonvulsant and memory impairment activity were assessed in PHT normal and reduced doses both alone and in combination with LEV. RAM error scores and convulsive scores were the parameters considered for this study. Brain acetylcholine esterase and glutamate were determined along with histopathological studies of frontal cortex. Results: Administration of PHT for 64 days on mice has shown aggravation of memory impairment activity on temporal lobe epileptic mice. Although the reduction in PHT dose was found to decrease the degree of memory impairment the same decreased the anticonvulsant potency. The combination with LEV not only brought about the correction of impaired memory but also replaced the loss of potency due to the reduction of the dose of the antiepileptic drug employed. These findings were confirmed with enzyme and neurotransmitter levels in addition to histopathological studies. Conclusion: This study thus builds a foundation in combining a nootropic anticonvulsant with an antiepileptic drug to curb the adverse effect of memory impairment associated with temporal lobe epilepsy. However further extensive research is a must for the practical incorporation of this approach into disease therapy.

Keywords: anti-epileptic drug, Phenytoin, memory impairment, Pilocarpine

Procedia PDF Downloads 307

Authors: Selamawit Hirpa, Girmay Medhin, Belaineh Girma, Muluken Melese, Alemayehu Mekonen, Pedro Suarez, Gobena Ameni

Abstract:

Worldwide, there were 650,000 multi-drug resistant tuberculosis (MDR-TB) cases in 2010. Ethiopia is 15th among the 27 MDR-TB high-burden countries. A case control study was conducted at St. Peter Hospital and five health centers in Addis Ababa. Cases were MDR-TB patients who were in treatment at St. Peter Hospital during the study period. Controls were patients who were on first-line anti-TB treatment and were registered as cured or having completed treatment in the period 9 April 2009– 28 February 2010, in five health centers. A structured interview questionnaire was used to assess factors that could potentially be associated with the occurrence of MDR-TB. Factors that were significantly associated with MDR-TB: drug side effects during first-line treatment (adjusted odds ratio (AOR): 4.5, 95% CI; 1.9 - 10.5); treatment not directly observed by a health worker (AOR = 11.7, 95% CI; 4–34.3); and retreatment with the Category II regimen (P = 0.000).

Keywords: adherence to TB treatment, MDR-TB, TB treatment, TB treatment regimens

Procedia PDF Downloads 492

Authors: Sreelekha Prakash, Yulong Gu

Abstract:

Background: About 61% of adults surveyed across 25 states reported they had experienced at least one type of Adverse Childhood Experience (ACE) before 18 years of age. Relationships between ACEs and a variety of substance-related behaviors and behavioral health have been reported in previous studies. ACEs can have lasting, negative effects on health, well-being, as well as life opportunities such as education and job potential. Objectives: For the current research, the aim was to assess the factors affecting substance use behavior in young adults. The further onset of drug use and its association was analyzed with ACEs and mental health. Method: The young adults from a county in the north-eastern United States were invited to participate in an online questionnaire survey with prior consent through an IRB approved study. The Survey included questions related to social determinants of health, 10 item ACE questionnaire, and substance use related to Alcohol, Marijuana, Opioids, Stimulants, and other drugs. PHQ-9 questionnaire was used to assess cognitive health. Results: Data was analyzed for the 244 completed surveys {68% (165) were females, and 78% (190) were Whites}. The average age of the participants was 26.7 years, and approximately 80% were lifelong residents of the county or year-round residents. Of the respondents, 50% (122) were high school graduates with some college education, and 56% (136) had a full-time jobs. Past 30-day usage for alcohol was 76% (72), and marijuana was 28.4% (27). The data showed that the higher the ACE scores, the younger they start using any substance (p < 0.0001). The data for PHQ-9 and ACE scores showed that the higher the ACE score, the higher the PHQ-9 score, with a significant p-value (p 0.0001). The current data also showed a significant association with other drugs; marijuana use showed significance for 30 days of use (p 0.0001), stimulant use (0.0008), prescription drug misuse (0.01), and opioids (0.01). Conclusion: These findings further support the association between ACEs and initiation of drug use and its correlation with mental health symptoms. Promoting a safe and supportive environment for children and youth in their earlier ages can prevent the youth and young adults from the effects of drug use and create healthy living habits for young adults.

Keywords: subtance use, young adults, adverse childhood experience, PHQ-9

Procedia PDF Downloads 79

Authors: M. J. Pourvaghar, Sh. Khoshemehry

Abstract:

Adopting inappropriate body posture during addiction can cause muscular and skeletal deformities. This study is aimed at investigating the effects of a program of the selected corrective exercises on the kyphosis of addicted male patients. Materials and methods: This was a quasi-experimental study. This study has been carried out using the semi-experimental method. The subjects of the present study included 104 addicted men between 25 to 45 years of age. In 2014, these men were referred to one of the NA (Narcotic Anonymous) centres in Kashan in 2015. A total of 24 people suffering from drug withdrawal, who had abnormal kyphosis, were purposefully selected as a sample. The sample was randomly divided into two groups, experimental and control; each group consisted of 12 people. The experimental group participated in a training program for 12 weeks consisting of three 60 minute sessions per week. That includes strengthening, stretching and PNF exercises (deep stretching of the muscle). The control group did no exercise or corrective activity. The Kolmogorov-Smirnov test was used to assess normal distribution of data; and a paired t-test and covariance analysis test were used to assess the effectiveness of the exercises, with a significance level of P≤0.05 by using SPSS18. The results showed that three months of the selected corrective exercises had a significant effect (P≤ 0.005) on the correction of the kyphosis of the addicted male patients after three months of rehabilitation (drug withdrawal) in the experimental group, while there was no significant difference recorded in the control group (P≥0.05). The results show that exercise and corrective activities can be used as non-invasive and non-pharmacological methods to rehabilitate kyphosis abnormalities after drug withdrawal and treatment for addiction.

Keywords: kyphosis, exercise-rehabilitation, addict, addiction

Procedia PDF Downloads 277

Authors: M. Osman Gani, M. Ferdows, Toshiyuki Ogawa

Abstract:

In this work, we proposed a modified FHN-type reaction-diffusion system for a bistable excitable system by adding a scaled function obtained from a given function. We study the existence and the stability of the periodic traveling waves (or wavetrains) for the FitzHugh-Nagumo (FHN) system and the modified one and compare the results. The stability results of the periodic traveling waves (PTWs) indicate that most of the solutions in the fast family of the PTWs are stable for the FitzHugh-Nagumo equations. The instability occurs only in the waves having smaller periods. However, the smaller period waves are always unstable. The fast family with sufficiently large periods is always stable in FHN model. We find that the oscillation of pulse widths is absent in the standard FHN model. That motivates us to study the PTWs in the proposed FHN-type reaction-diffusion system for the bistable excitable media. A good agreement is found between the solutions of the traveling wave ODEs and the corresponding whole PDE simulation.

Keywords: bistable system, Eckhaus bifurcation, excitable media, FitzHugh-Nagumo model, periodic traveling waves

Procedia PDF Downloads 180

Authors: Larissa Burruano, Sergey Grabovyj, Irina Nguen

Abstract:

The study aimed to assess the level of adherence to anti retroviral therapy (ART) and to examine the relationship between adherence and risk behavior factor (drug use) among patients infected with HIV. The patients with newly diagnosed or established HIV infection under follow-up at the Sumskij Regional Centre for AIDS Prevention in Ukraine were eligible for this study. Medical records were used to measure the patient’s adherence to medication. Measurements were obtained at month 6 and at month 12 to calculate the number of medication omission during the past 30 days: (on a 2-point scale – once until three in a month – were considered adherent, three and more in a month – were considered non-adherent). Of the 50 study participants, 27 (54.0%) were men and 23 (46.0%) women. The mean age is 35.2 years (SD= 5.1). A majority of the patients (82.0%) is in the age group of 25-30 years. The main level of adherence was 74.0% and 66.0% at 6 and 12 months, respectively. The main routes of HIV transmission were drug injection among men 12 (44.4%) and sexual contact among women 11 (47.8%). Univariate analyses indicated that patients who had lower level of education were more likely to have been non-adherent at month 6- (X2 =5.1, n=50, p < .05) and at month 12 (X2 = 4.34, n=50, p < .05). Multivariate tests showed that only age (OR= 1.163 [95% CI 0.98–1.370]) was significant independent predictor of treatment adherence, while gender, education, employment status were not predictive for the risk of developing non-compliance. There was not a significant interaction between non-adherence and intravenous drug use. Consistent with these findings, younger people were more likely to have missed a dose of their medication because they had a greater sense of invulnerability than older patients. The study indicates that the socio demographic characteristic should be taken into an account in the future research regarding adherence in the case of HIV infection. If the patient anti retroviral adherence can be improved by qualitatively better medical care in all regions of the Ukraine, behavioral changes in the population can to be expected in the long term.

Keywords: HIV, antiretroviral therapy, adherence, Ukraine, Eastern Europe

Procedia PDF Downloads 283

Authors: Phenphak Horadee, Rodchares Hanrinth, Saithip Suttiruksa

Abstract:

Inappropriate use of antibiotics has happened in several hospitals, Thailand. Drug use evaluation (DUE) is one strategy to overcome this difficulty. However, most community hospitals still encounter incomplete evaluation resulting overuse of antibiotics with high cost. Consequently, drug-resistant bacteria have been rising due to inappropriate antibiotic use. The aim of this study was to involve stakeholders in conceptualizing, developing, and prioritizing a feasible intervention strategy to promote and support appropriate antibiotic prescribing in a community hospital, Thailand. Study antibiotics included four antibiotics such as Meropenem, Piperacillin/tazobactam, Amoxicillin/clavulanic acid, and Vancomycin. The study was conducted for the 1-year period between March 1, 2018, and March 31, 2019, in a community hospital in the northeastern part of Thailand. Concept mapping was used in a purposive sample, including doctors (one was an administrator), pharmacists, and nurses who involving drug use evaluation of antibiotics. In-depth interviews for each participant and survey research were conducted to seek the problems for inappropriate use of antibiotics based on drug use evaluation system. Seventy-seven percent of DUE reported appropriate antibiotic prescribing, which still did not reach the goal of 80 percent appropriateness. Meropenem led other antibiotics for inappropriate prescribing. The causes of the unsuccessful DUE program were classified into three themes such as personnel, lack of public relation and communication, and unsupported policy and impractical regulations. During the first meeting, stakeholders (n = 21) expressed the generation of interventions. During the second meeting, participants who were almost the same group of people in the first meeting (n = 21) were requested to independently rate the feasibility and importance of each idea and to categorize them into relevant clusters to facilitate multidimensional scaling and hierarchical cluster analysis. The outputs of analysis included the idealist, cluster list, point map, point rating map, cluster map, and cluster rating map. All of these were distributed to participants (n = 21) during the third meeting to reach consensus on an intervention model. The final proposed intervention strategy included 29 feasible and crucial interventions in seven clusters: development of information technology system, establishing policy and taking it into the action plan, proactive public relations of the policy, action plan and workflow, in cooperation of multidisciplinary teams in drug use evaluation, work review and evaluation with performance reporting, promoting and developing professional and clinical skill for staff with training programs, and developing practical drug use evaluation guideline for antibiotics. These interventions are relevant and fit to several intervention strategies for antibiotic stewardship program in many international organizations such as participation of the multidisciplinary team, developing information technology to support antibiotic smart use, and communication. These interventions were prioritized for implementation over a 1-year period. Once the possibility of each activity or plan is set up, the proposed program could be applied and integrated into hospital policy after evaluating plans. Effectiveness of each intervention could be promoted to other community hospitals to promote and support antibiotic smart use.

Keywords: antibiotic, concept mapping, drug use evaluation, multidisciplinary teams

Procedia PDF Downloads 113

Authors: Ignacio Luis Ramirez, Brittney Holcomb

Abstract:

This study examines attitudes toward sexual assault based on religious affiliation, religiosity, religious beliefs, attitude about sexual assault education, alcohol, and drug use. This study found respondents who identified themselves as Catholics had more negative attitudes toward sexual assault and were more likely to support victim-blaming statements than Baptists or Protestants. Respondents who indicated a greater problem with alcohol had more negative attitudes toward sexual assault and were more likely to support victim-blaming statements. In reference to gender, males had more negative attitudes toward sexual assault and were more likely to support victim-blaming statements than females. The respondent’s religiosity and religious beliefs did not affect their attitudes toward sexual assault. Additionally, attitudes about sexual assault education and drug use did not affect attitudes toward sexual assault.

Keywords: sexual assault, religion, education, alcohol, drugs

Procedia PDF Downloads 173