Search results for: drug stability
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 5148

Search results for: drug stability

4458 Oral Lichen Planus a Manifestation of Grinspan's Syndrome or a Lichenoid Reaction to Medication

Authors: Sahar Iqrar, Malik Adeel Anwar, Zain Akram, Maria Noor

Abstract:

Introduction: Oral lichen planus is a chronic inflammatory condition of unknown etiology. Oral lichen planus may be related with several other diseases. Grinspan's Syndrome is characterized by a triad of oral lichen planus, hypertension, and diabetes mellitus. Other associations reported in the literature are with chronic liver disease and, with dyslipidemia. The nature of these associations is still not fully understood. Material and methods: Study was conducted in Department of Oral Medicine, Fatima Memorial Hospital College of Medicine and Dentistry, Lahore, Pakistan. A total of n=89 clinically diagnosed patients of oral lichen planus of both gender and all age groups were recruited and detailed history were recorded in the designed performs. Results: A total of n=89 patients were taken with male to female ratio of 3:8 in which 24 were male and 65 females. Mean age was 48.8 ± 13.8 years. Age range of 10-74 years was seen. Among these patients suffering from oral lichen planus, 41.6% (n=37) had a positive history for hypertension with 59.5% (n=22) of these patients were taking different medication for their condition. Whereas Diabetes Mellitus was found in 24.7% (n=22) patients with 72.7% (n=16) of these patients using the hypoglycemic drug (oral or injectable) to control their blood glucose levels. Out of these n=89 lichen planus patients 21.3% had both hypertension and diabetes mellitus (fulfilling the criteria for Grinspan's Syndrome). Out of this Grinspan's Syndrome pool 94.7% (n=19) were taking drug atleast for one of the two conditions. Conclusion: As noticed form the medical history of the patients, most of them were using hypoglycemic drugs for diabetes mellitus and beta blockers, diuretics and calcium channel blockers for hypertension. These drugs are known for lichenoid reaction. Therefore, it should be ruled out at histopathological/ immunological and molecular level whether these patients are suffering from lichen planus or lichenoid drug reaction to truly declare them as patients with Grinspan’s Syndrome.

Keywords: diabetes mellitus, grinspan's syndrome, lichenoid drug reaction, oral lichen planus

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4457 Modeling and Control Design of a Centralized Adaptive Cruise Control System

Authors: Markus Mazzola, Gunther Schaaf

Abstract:

A vehicle driving with an Adaptive Cruise Control System (ACC) is usually controlled decentrally, based on the information of radar systems and in some publications based on C2X-Communication (CACC) to guarantee stable platoons. In this paper, we present a Model Predictive Control (MPC) design of a centralized, server-based ACC-System, whereby the vehicular platoon is modeled and controlled as a whole. It is then proven that the proposed MPC design guarantees asymptotic stability and hence string stability of the platoon. The Networked MPC design is chosen to be able to integrate system constraints optimally as well as to reduce the effects of communication delay and packet loss. The performance of the proposed controller is then simulated and analyzed in an LTE communication scenario using the LTE/EPC Network Simulator LENA, which is based on the ns-3 network simulator.

Keywords: adaptive cruise control, centralized server, networked model predictive control, string stability

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4456 Zika Virus NS5 Protein Potential Inhibitors: An Enhanced in silico Approach in Drug Discovery

Authors: Pritika Ramharack, Mahmoud E. S. Soliman

Abstract:

The re-emerging Zika virus is an arthropod-borne virus that has been described to have explosive potential as a worldwide pandemic. The initial transmission of the virus was through a mosquito vector, however, evolving modes of transmission has allowed the spread of the disease over continents. The virus already been linked to irreversible chronic central nervous system (CNS) conditions. The concerns of the scientific and clinical community are the consequences of Zika viral mutations, thus suggesting the urgent need for viral inhibitors. There have been large strides in vaccine development against the virus but there are still no FDA-approved drugs available. Rapid rational drug design and discovery research is fundamental in the production of potent inhibitors against the virus that will not just mask the virus, but destroy it completely. In silico drug design allows for this prompt screening of potential leads, thus decreasing the consumption of precious time and resources. This study demonstrates an optimized and proven screening technique in the discovery of two potential small molecule inhibitors of Zika virus Methyltransferase and RNA-dependent RNA polymerase. This in silico “per-residue energy decomposition pharmacophore” virtual screening approach will be critical in aiding scientists in the discovery of not only effective inhibitors of Zika viral targets, but also a wide range of anti-viral agents.

Keywords: NS5 protein inhibitors, per-residue decomposition, pharmacophore model, virtual screening, Zika virus

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4455 Concanavaline a Conjugated Bacterial Polyester Based PHBHHx Nanoparticles Loaded with Curcumin for the Ovarian Cancer Therapy

Authors: E. Kilicay, Z. Karahaliloglu, B. Hazer, E. B. Denkbas

Abstract:

In this study, we have prepared concanavaline A (ConA) functionalized curcumin (CUR) loaded PHBHHx (poly(3-hydroxybutyrate-co-3-hydroxyhexanoate)) nanoparticles as a novel and efficient drug delivery system. CUR is a promising anticancer agent for various cancer types. The aim of this study was to evaluate therapeutic potential of curcumin loaded PHBHHx nanoparticles (CUR-NPs) and concanavaline A conjugated curcumin loaded NPs (ConA-CUR NPs) for ovarian cancer treatment. ConA was covalently connected to the carboxylic group of nanoparticles by EDC/NHS activation method. In the ligand attachment experiment, the binding capacity of ConA on the surface of NPs was found about 90%. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) analysis showed that the prepared nanoparticles were smooth and spherical in shape. The size and zeta potential of prepared NPs were about 228±5 nm and −21.3 mV respectively. ConA-CUR NPs were characterized by FT-IR spectroscopy which confirmed the existence of CUR and ConA in the nanoparticles. The entrapment and loading efficiencies of different polymer/drug weight ratios, 1/0.125 PHBHHx/CUR= 1.25CUR-NPs; 1/0.25 PHBHHx/CUR= 2.5CUR-NPs; 1/0.5 PHBHHx/CUR= 5CUR-NPs, ConA-1.25CUR NPs, ConA-2.5CUR NPs and ConA-5CUR NPs were found to be ≈ 68%-16.8%; 55%-17.7 %; 45%-33.6%; 70%-15.7%; 60%-17%; 51%-30.2% respectively. In vitro drug release showed that the sustained release of curcumin was observed from CUR-NPs and ConA-CUR NPs over a period of 19 days. After binding of ConA, the release rate was slightly increased due to the migration of curcumin to the surface of the nanoparticles and the matrix integrities was decreased because of the conjugation reaction. This functionalized nanoparticles demonstrated high drug loading capacity, sustained drug release profile, and high and long term anticancer efficacy in human cancer cell lines. Anticancer activity of ConA-CUR NPs was proved by MTT assay and reconfirmed by apoptosis and necrosis assay. The anticancer activity of ConA-CUR NPs was measured in ovarian cancer cells (SKOV-3) and the results revealed that the ConA-CUR NPs had better tumor cells decline activity than free curcumin. The nacked nanoparticles have no cytotoxicity against human ovarian carcinoma cells. Thus the developed functionalized nanoformulation could be a promising candidate in cancer therapy.

Keywords: curcumin, curcumin-PHBHHx nanoparticles, concanavalin A, concanavalin A-curcumin PHBHHx nanoparticles, PHBHHx nanoparticles, ovarian cancer cell

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4454 Unprecedented Bioactive Naturally-occurring Compounds from the Rare and Endangered Plants Endemic to China

Authors: Jin-Feng Hu

Abstract:

Over the past decades, the global biodiversity has continued to decline. The threats to the terrestrial plant species have increased under anthropogenic activities and other massive ecological change impacts. The situation is much more serious in China, the third richest countries regarding plant biodiversity in the world. It was not until 1992 that the first volume of the China Plant Red Data Book was published. Nowadays, a significant number of Chinese endemic plants have been threatened (The IUCN Red List). Nevertheless, plant-originated natural products (NPs) have continued to play a crucial role in the drug discovery and development process. The opportunity for identifying new chemical entities for emerging and malignant diseases depends on a diversity of drug-producing species. Several statistical surveys unveiled that the rare and endangered plants (REPs) have proven to be better sources for drug discovery than other botanic sources. The identification of bioactive NPs from REPs reveals the importance of conservation efforts in preventing species diversity loss and addressing human diseases at the same time. Thus, there is an urgent need to investigate these fragile REPs. Since 2013, our group has initially launched a special program to systematically identify bioactive/novel NPs from REPs native to China. The selected plant species were generally collected from the remote Mountain areas, and have never been chemically or pharmacologically investigated. Due to the difficult collection of the mass-limited samples of REPs, studies on the secondary metabolites of REPs-associated endophytes would provide a promising alternative potential solution. This presentation details the achievements that related to a series of “Phytochemical and biological studies on rare and endangered plants endemic to China”.

Keywords: bioactive naturally-occrring compounds, rare and endengered plants (REPs), plant endophytes, drug discovery

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4453 Purification and Pre-Crystallization of Recombinant PhoR Cytoplasmic Domain Protein from Mycobacterium Tuberculosis H37Rv

Authors: Oktira Roka Aji, Maelita R. Moeis, Ihsanawati, Ernawati A. Giri-Rachman

Abstract:

Globally, tuberculosis (TB) remains a leading cause of death. The emergence of multidrug-resistant strains and extensively drug-resistant strains have become a major public concern. One of the potential candidates for drug target is the cytoplasmic domain of PhoR Histidine Kinase, a part of the Two Component System (TCS) PhoR-PhoP in Mycobacterium tuberculosis (Mtb). TCS PhoR-PhoP relay extracellular signal to control the expression of 114 virulent associated genes in Mtb. The 3D structure of PhoR cytoplasmic domain is needed to screen novel drugs using structure based drug discovery. The PhoR cytoplasmic domain from Mtb H37Rv was overexpressed in E. coli BL21(DE3), then purified using IMAC Ni-NTA Agarose his-tag affinity column and DEAE-ion exchange column chromatography. The molecular weight of the purified protein was estimated to be 37 kDa after SDS-PAGE analysis. This sample was used for pre-crystallization screening by applying sitting drop vapor diffusion method using Natrix (HR2-116) 48 solutions crystal screen kit at 25ºC. Needle-like crystals were observed after the seventh day of incubation in test solution No.47 (0.1 M KCl, 0.01 M MgCl2.6H2O, 0.05 M Tris-Cl pH 8.5, 30% v/v PEG 4000). Further testing is required for confirming the crystal.

Keywords: tuberculosis, two component system, histidine kinase, needle-like crystals

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4452 On the Other Side of Shining Mercury: In Silico Prediction of Cold Stabilizing Mutations in Serine Endopeptidase from Bacillus lentus

Authors: Debamitra Chakravorty, Pratap K. Parida

Abstract:

Cold-adapted proteases enhance wash performance in low-temperature laundry resulting in a reduction in energy consumption and wear of textiles and are also used in the dehairing process in leather industries. Unfortunately, the possible drawbacks of using cold-adapted proteases are their instability at higher temperatures. Therefore, proteases with broad temperature stability are required. Unfortunately, wild-type cold-adapted proteases exhibit instability at higher temperatures and thus have low shelf lives. Therefore, attempts to engineer cold-adapted proteases by protein engineering were made previously by directed evolution and random mutagenesis. The lacuna is the time, capital, and labour involved to obtain these variants are very demanding and challenging. Therefore, rational engineering for cold stability without compromising an enzyme's optimum pH and temperature for activity is the current requirement. In this work, mutations were rationally designed with the aid of high throughput computational methodology of network analysis, evolutionary conservation scores, and molecular dynamics simulations for Savinase from Bacillus lentus with the intention of rendering the mutants cold stable without affecting their temperature and pH optimum for activity. Further, an attempt was made to incorporate a mutation in the most stable mutant rationally obtained by this method to introduce oxidative stability in the mutant. Such enzymes are desired in detergents with bleaching agents. In silico analysis by performing 300 ns molecular dynamics simulations at 5 different temperatures revealed that these three mutants were found to be better in cold stability compared to the wild type Savinase from Bacillus lentus. Conclusively, this work shows that cold adaptation without losing optimum temperature and pH stability and additionally stability from oxidative damage can be rationally designed by in silico enzyme engineering. The key findings of this work were first, the in silico data of H5 (cold stable savinase) used as a control in this work, corroborated with its reported wet lab temperature stability data. Secondly, three cold stable mutants of Savinase from Bacillus lentus were rationally identified. Lastly, a mutation which will stabilize savinase against oxidative damage was additionally identified.

Keywords: cold stability, molecular dynamics simulations, protein engineering, rational design

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4451 The Use of the Limit Cycles of Dynamic Systems for Formation of Program Trajectories of Points Feet of the Anthropomorphous Robot

Authors: A. S. Gorobtsov, A. S. Polyanina, A. E. Andreev

Abstract:

The movement of points feet of the anthropomorphous robot in space occurs along some stable trajectory of a known form. A large number of modifications to the methods of control of biped robots indicate the fundamental complexity of the problem of stability of the program trajectory and, consequently, the stability of the control for the deviation for this trajectory. Existing gait generators use piecewise interpolation of program trajectories. This leads to jumps in the acceleration at the boundaries of sites. Another interpolation can be realized using differential equations with fractional derivatives. In work, the approach to synthesis of generators of program trajectories is considered. The resulting system of nonlinear differential equations describes a smooth trajectory of movement having rectilinear sites. The method is based on the theory of an asymptotic stability of invariant sets. The stability of such systems in the area of localization of oscillatory processes is investigated. The boundary of the area is a bounded closed surface. In the corresponding subspaces of the oscillatory circuits, the resulting stable limit cycles are curves having rectilinear sites. The solution of the problem is carried out by means of synthesis of a set of the continuous smooth controls with feedback. The necessary geometry of closed trajectories of movement is obtained due to the introduction of high-order nonlinearities in the control of stabilization systems. The offered method was used for the generation of trajectories of movement of point’s feet of the anthropomorphous robot. The synthesis of the robot's program movement was carried out by means of the inverse method.

Keywords: control, limits cycle, robot, stability

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4450 Disposition Kinetics of Ciprofloxacin after Intramuscular Administration in Lohi Sheep

Authors: Zahid Iqbal, Ijaz Javed, Riaz Hussain, Ibadullah Jan, Amir Ali Khan

Abstract:

This study was conducted to investigate the disposition kinetics of ciprofloxacin and calculate its optimal dosage in Pakistani sheep of Lohi breed. Injectable preparation of ciprofloxacin was given intramuscularly to eight sheep at a dose of 5 mg/Kg. Before administration of drug blood sample was drawn from each animal. Post drug administration, blood samples were also drawn at various predetermined time periods. Drug concentration in the blood samples was assessed through high performance liquid chromatograph (HPLC). Data were best described by two compartment open model and different pharmacokinetic (PK) parameters were calculated. Cmax of 1.97 ± 0.15 µg/ml was reached at Tmax of 0.88 ± 0.09 hours. Half life of absorption (t1/2 abs) was observed to be 0.63 ± 0.16 hours while t1/2 α (distribution half life) and t1/2 ß (elimination half life) were found to be 0.46 ± 0.05 and 2.93 ± 0.45 hours, respectively. Vd (apparent volume of distribution) was calculated as 2.89 ± 0.30 L/kg while AUC (area under the curve) was 7.19 ± 0.38 µg.hr/mL and CL (total body clearance) was 0.75 ± 0.04 L/hr/kg. Using these parameters, an optimal intramuscular dosage of ciprofloxacin in adult Lohi sheep was calculated as 21.43 mg/kg, advised to be repeated after 24 hours. From this, we came to the conclusion that calculated dose was much higher than the dose advised by the foreign manufacturer and to avoid antimicrobial resistance, it is advised that this locally investigated dosage regimen should be strictly followed in local sheep.

Keywords: pharmacokinetics, dosage regimen, ciprofloxacin, HPLC, sheep

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4449 Preparation, Characterisation, and Measurement of the in vitro Cytotoxicity of Mesoporous Silica Nanoparticles Loaded with Cytotoxic Pt(II) Oxadiazoline Complexes

Authors: G. Wagner, R. Herrmann

Abstract:

Cytotoxic platinum compounds play a major role in the chemotherapy of a large number of human cancers. However, due to the severe side effects for the patient and other problems associated with their use, there is a need for the development of more efficient drugs and new methods for their selective delivery to the tumours. One way to achieve the latter could be in the use of nanoparticular substrates that can adsorb or chemically bind the drug. In the cell, the drug is supposed to be slowly released, either by physical desorption or by dissolution of the particle framework. Ideally, the cytotoxic properties of the platinum drug unfold only then, in the cancer cell and over a longer period of time due to the gradual release. In this paper, we report on our first steps in this direction. The binding properties of a series of cytotoxic Pt(II) oxadiazoline compounds to mesoporous silica particles has been studied by NMR and UV/vis spectroscopy. High loadings were achieved when the Pt(II) compound was relatively polar, and has been dissolved in a relatively nonpolar solvent before the silica was added. Typically, 6-10 hours were required for complete equilibration, suggesting the adsorption did not only occur to the outer surface but also to the interior of the pores. The untreated and Pt(II) loaded particles were characterised by C, H, N combustion analysis, BET/BJH nitrogen sorption, electron microscopy (REM and TEM) and EDX. With the latter methods we were able to demonstrate the homogenous distribution of the Pt(II) compound on and in the silica particles, and no Pt(II) bulk precipitate had formed. The in vitro cytotoxicity in a human cancer cell line (HeLa) has been determined for one of the new platinum compounds adsorbed to mesoporous silica particles of different size, and compared with the corresponding compound in solution. The IC50 data are similar in all cases, suggesting that the release of the Pt(II) compound was relatively fast and possibly occurred before the particles reached the cells. Overall, the platinum drug is chemically stable on silica and retained its activity upon prolonged storage.

Keywords: cytotoxicity, mesoporous silica, nanoparticles, platinum compounds

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4448 Investigation of Static Stability of Soil Slopes Using Numerical Modeling

Authors: Seyed Abolhasan Naeini, Elham Ghanbari Alamooti

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Static stability of soil slopes using numerical simulation by a finite element code, ABAQUS, has been investigated, and safety factors of the slopes achieved in the case of static load of a 10-storey building. The embankments have the same soil condition but different loading distance from the slope heel. The numerical method for estimating safety factors is 'Strength Reduction Method' (SRM). Mohr-Coulomb criterion used in the numerical simulations. Two steps used for measuring the safety factors of the slopes: first is under gravity loading, and the second is under static loading of a building near the slope heel. These safety factors measured from SRM, are compared with the values from Limit Equilibrium Method, LEM. Results show that there is good agreement between SRM and LEM. Also, it is seen that by increasing the distance from slope heel, safety factors increases.

Keywords: limit equilibrium method, static stability, soil slopes, strength reduction method

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4447 The Lytic Bacteriophage VbɸAB-1 Against Drug-Resistant Acinetobacter Baumannii Isolated from Hospitalized Pressure Ulcers Patients

Authors: M. Doudi, M. H. Pazandeh, L. Rahimzadeh Torabi

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Bedsores are pressure ulcers that occur on the skin or tissue due to being immobile and lying in bed for extended periods. Bedsores have the potential to progress into open ulcers, increasing the possibility of a variety of bacterial infections. Acinetobacter baumannii, a pathogen of considerable clinical importance, exhibited a significant correlation with Bedsores (pressure ulcers) infections, thereby manifesting a wide spectrum of antibiotic resistance. The emergence of drug resistance has led researchers to focus on alternative methods, particularly phage therapy, for tackling bacterial infections. Phage therapy has emerged as a novel therapeutic approach to regulate the activity of these agents. The management of bacterial infections greatly benefits from the clinical utilization of bacteriophages as a valuable antimicrobial intervention. The primary objective of this investigation consisted of isolating and discerning potent bacteriophage capable of targeting multi-drug-resistant (MDR) and extensively drug-resistant (XDR) bacteria obtained from pressure ulcers. The present study analyzed and isolated A. baumannii strains obtained from a cohort of patients suffering from pressure ulcers at Taleghani Hospital in Ahvaz, Iran. An approach that included biochemical and molecular identification techniques was used to determine the taxonomic classification of bacterial isolates at the genus and species levels. The molecular identification process was facilitated by using the 16S rRNA gene in combination with universal primers 27 F and 1492 R. Bacteriophage was obtained through the isolation process conducted on treatment plant sewage located in Isfahan, Iran. The main goal of this study was to evaluate different characteristics of phage, such as their appearance, the range of hosts they can infect, how quickly they can enter a host, their stability at varying temperatures and pH levels, their effectiveness in killing bacteria, the growth pattern of a single phage stage, mapping of enzymatic digestion, and identification of proteomics patterns. The findings demonstrated that an examination was conducted on a sample of 50 specimens, wherein 15 instances of A. baumannii were identified. These microorganisms are the predominant Gram-negative agents known to cause wound infections in individuals suffering from bedsores. The study's findings indicated a high prevalence of antibiotic resistance in the strains isolated from pressure ulcers, excluding the clinical strains that exhibited responsiveness to colistin. According to the findings obtained from assessments of host range and morphological characteristics of bacteriophage VbɸAB-1, it can be concluded that this phage possesses specificity towards A. Baumannii BAH_Glau1001 was classified as a member of the Podoviridae family. The bacteriophage mentioned earlier showed the strongest antibacterial effect at a temperature of 18 °C and a pH of 6.5. Through the utilization of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis on protein fragments, it was established that the bacteriophage VbɸAB-1 exhibited a size range between 50 and 75 kilodaltons (KDa). The numerous research findings on the effectiveness of phages and the safety studies conducted suggest that the phages studied in this research can be considered as a practical solution and recommended approach for controlling and treating stubborn pathogens in burn wounds among hospitalized patients. The findings of our research indicated that isolated phages could be an effective antimicrobial and an appreciate candidate for prophylaxis against pressure ulcers.

Keywords: acinetobacter baumannii, extremely drug-resistant, phage therapy, surgery wound

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4446 Investigating the Dynamic Response of the Ballast

Authors: Osama Brinji, Wing Kong Chiu, Graham Tew

Abstract:

Understanding the stability of rail ballast is one of the most important aspects in the railways. An unstable track may cause some issues such as unnecessary vibration and ultimately loss of track quality. The track foundation plays an important role in the stabilization of the railway. The dynamic response of rail ballast in the vicinity of the rail sleeper can affect the stability of the rail track and this has not been studied in detail. A review of literature showed that most of the works focused on the area under the concrete sleeper. Although there are some theories about the shear (longitudinal) effect of the rail ballast, these have not properly been studied and hence are not well understood. The stability of a rail track will depend on the compactness of the ballast in its vicinity. This paper will try to determine the dynamic response of the ballast to identify its resonant behaviour. This preliminary research is one of several studies that examine the vibration response of the granular materials. The main aim is to use this information for future design of sleepers to ensure that any dynamic response of the sleeper will not compromise the state of compactness of the ballast. This paper will report on the dependence of damping and the natural frequency of the ballast as a function of depth and distance from the point of excitation introduced through a concrete block. The concrete block is used to simulate a sleeper and the ballast is simulated with gravel. In spite of these approximations, the results presented in the paper will show an agreement with theories and the assumptions that are used in study the mechanical behaviour of the rail ballast.

Keywords: ballast, dynamic response, sleeper, stability

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4445 Effects of Local Decongestive Agents at Trachea and Lungs

Authors: Sertac Arslan, Guven Guney, Ayse Ipek Akyuz Unsal, Emre Demir, Buket Demirci

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Purpose: There is little histologic data concerning effects of nasal decongestants on the respiratory tract. We aimed to put forth the effects of nasal decongestants on the trachea and lower airways of rats. Materials and Methods: Four to six months old 60 male rats were randomly categorized into 6 groups. Experimental drugs were applied to the same nostril of rats twice daily for 8 weeks (Xylometazolin, Benzalkolyum, EDTA, Sorbitol and combined drug solutions). We applied normal saline solution (NaCl %0.9) for the control group. In the end, trachea and both lungs were dissected and kept in formaldehyde for histopathologic evaluation. Results: Inflammation and bronchial edema were most common findings. While all rats in sorbitol group had increased numbers of type 2 pneumocytes; 80% of BAC group had increased numbers of type 2 pneumocytes. Spillover of tracheal epithelium was seen mostly in sorbitol, EDTA and combined drug groups (60%, 87.5%, 50% respectively). Bronchial smooth muscle hypertrophy was seen mostly in BAC and EDTA group (70%, 62.5% respectively). The number of goblet cells showed the significant difference between control-combined drug (p=0.025) and control-BAC (p=0.001) groups. Conclusions: Nasal decongestants can cause permanent changes at lower respiratory tract in addition to changes in upper respiratory tract.

Keywords: decongestive agents, xylometazoline, lung, trachea

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4444 Synthesis and Solubilization of Flurbiprofen Derivatives and Investigation of Their Biological Activities

Authors: Muhammad Mustaqeem, Musa Kaleem Baloch, Irfan Ullah, Ammarah Luqman, Afshan Ahmad

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Flurbiprofen is one of the most potent nonsteroidal anti-inflammatory drugs. It is widely used for relief of pain in patients suffering from rheumatic diseases, migraine, sore throat and primary dysmenorrhea. However, its aqueous solubility is very low and hinders the skin permeation. Thus, it is imperative to develop such a drug delivery systems which can improve its aqueous solubility and hence improve the skin permeation and therapeutic compliance. Microemulsions have been also proven to increase the cutaneous absorption of lipophilic drugs as compared to conventional vehicles. Micro-emulsion is thermodynamically stable emulsion that has the capacity to ‘hide/solubilize’ water-insoluble molecules within a continuous oil phase. Therefore, flurbiprofen was converted to Easters through chemical reactions with alcohols such as methanol, ethanol, propanol and butanol. The product was further treated with hydrazine to get hydrazide. The solubility of the parent drug Flurbiprofen and the products were solubilized in microemulsions formed using various surfactants like ionic, non-ionic and zwitterions. It has been concluded that the product was more soluble than the parent compound. The biological activities of these were also investigated. The outcome was very promising and the product was more active than the parent compound. It, therefore, concluded that in this way, we can not only enhance the solubility of the drug and increase its bioactivity, but also reduce the risk of stomach cancer.

Keywords: Flurbiprofen, microemulsion, surfactants, hyrazides

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4443 Mining the Proteome of Fusobacterium nucleatum for Potential Therapeutics Discovery

Authors: Abdul Musaweer Habib, Habibul Hasan Mazumder, Saiful Islam, Sohel Sikder, Omar Faruk Sikder

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The plethora of genome sequence information of bacteria in recent times has ushered in many novel strategies for antibacterial drug discovery and facilitated medical science to take up the challenge of the increasing resistance of pathogenic bacteria to current antibiotics. In this study, we adopted subtractive genomics approach to analyze the whole genome sequence of the Fusobacterium nucleatum, a human oral pathogen having association with colorectal cancer. Our study divulged 1499 proteins of Fusobacterium nucleatum, which has no homolog in human genome. These proteins were subjected to screening further by using the Database of Essential Genes (DEG) that resulted in the identification of 32 vitally important proteins for the bacterium. Subsequent analysis of the identified pivotal proteins, using the KEGG Automated Annotation Server (KAAS) resulted in sorting 3 key enzymes of F. nucleatum that may be good candidates as potential drug targets, since they are unique for the bacterium and absent in humans. In addition, we have demonstrated the 3-D structure of these three proteins. Finally, determination of ligand binding sites of the key proteins as well as screening for functional inhibitors that best fitted with the ligands sites were conducted to discover effective novel therapeutic compounds against Fusobacterium nucleatum.

Keywords: colorectal cancer, drug target, Fusobacterium nucleatum, homology modeling, ligands

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4442 Brexit and Financial Stability: An Agent-Based Simulation

Authors: Aristeidis Samitas, Stathis Polyzos

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As the UK and the EU prepare to start negotiations for Brexit, it is important for both sides to comprehend the full extent of the consequences of this process. In this paper, we employ an object oriented simulation framework in order to test for the short-term and long-term effects of Brexit on both sides of the Channel. The relative strength of the UK economy and the banking sector vis-à-vis the EU is taken under consideration. Our results confirm predictions in the relevant literature regarding the output cost of Brexit, with particular emphasis on the EU. Furthermore, we show that financial stability is also an important issue on both sides, with the banking system suffering significant losses, particularly over the longer term. Our findings suggest that policymakers should be extremely careful in handling Brexit negotiations, making sure to consider dynamic effects that may be caused by UK bank assets moving to the EU after Brexit. The model results show that, as the UK banking system loses its assets, the end state of the UK economy is deteriorated while the end state of EU economy is improved.

Keywords: Banking Crises, Brexit, Financial Stability, VBanking

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4441 Effects of Kinesio Taping on Postural Stability in Young Soccer Players

Authors: Mustafa Gulsen, Nihan Pekyavas, Emine Atıcı

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Purpose: The aim of this study is to investigate the effects of Kinesio taping on postural stability and in young soccer players. Subjects and Methods: 62 volunteered soccer players from Cayyolu Sports Club were included in our study. Permissions were also taken from the club directors about the inclusion of their players to our study. Soccer players between the age of 12 and 16 were included in our study. Players that had previous injury on lower extremities were excluded from the study. Players were randomly divided into two groups: Kinesio taping (KT) (n=31), and control group (n = 31). KT application including gastrocnemius and quadriceps femoris muscle facilitation techniques were applied to the first group. A rest time for 45 minutes was given in order to see the best effectiveness of the tape. The second group was set as the control group and no application was made. All participants were assessed before the application and 45 minutes later. In order to provide the double-blind design of the study, an experienced physiotherapist has done the assessments and another experienced physiotherapist has done the taping. The patients were randomly assigned to one of the two groups using an online random allocation software program. Postural stability was assessed by using Tetrax Interactive Balance System. Thermographic assessment was done by using FLIR E5 (FLIR Systems AB, Sweden) thermal camera in order to see which muscles have the most thermal activity while maintaining postural stability. Results: Statistically significant differences were found in all assessment parameters in both Kinesio Taping and control groups (all p<0.05) except thermal imaging of dominant gastrocnemius muscle results (p=0.668) (Table 1). In comparison of the two groups, statistically significant differences were found in all parameters (all p<0.05). Conclusion: In this study, we investigated the effects of Kinesio taping on postural stability in young soccer players and found that KT application on Quadriceps and Gastrocnemius muscles may have decreased the risk of falling more than the control group. According to thermal imaging assessments, both Quadriceps and Gastrocnemius muscles may be active in maintaining postural stability but in KT group, the temperature of these muscles are higher which leads us to think that they are more activated.

Keywords: Kinesio taping, fall risk, muscle temperature, postural stability

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4440 Impact of Flavor on Food Product Quality, A Case Study of Vanillin Stability during Biscuit Preparation

Authors: N. Yang, R. Linforth, I. Fisk

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The influence of food processing and choice of flavour solvent was investigated using biscuits prepared with vanillin flavour as an example. Powder vanillin either was added directly into the dough or dissolved into flavour solvent then mixed into the dough. The impact of two commonly used flavour solvents on food quality was compared: propylene glycol (PG) or triacetin (TA). The analytical approach for vanillin detection was developed by chromatography (HPLC-PDA), and the standard extraction method for vanillin was also established. The results indicated the impact of solvent choice on vanillin level during biscuit preparation. After baking, TA as a more heat resistant solvent retained more vanillin than PG, so TA is a better solvent for products that undergo a heating process. The results also illustrated the impact of mixing and baking on vanillin stability in the matrices. The average loss of vanillin was 33% during mixing and 13% during baking, which indicated that the binding of vanillin to fat or flour before baking might cause larger loss than evaporation loss during baking.

Keywords: biscuit, flavour stability, food quality, vanillin

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4439 Study Regarding Effect of Isolation on Social Behaviour in Mice

Authors: Ritu Shitak

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Humans are social mammals, of the primate order. Our biology, behaviour, and pathologies are unique to us. In our desire to understand, reduce solitary confinement one source of information is the many reports of social isolation of other social mammals, especially primates. A behavioural study was conducted in the department of pharmacology at Indira Gandhi Medical College, Shimla in Himachal Pradesh province in India using white albino mice. Different behavioural parameters were observed by using open field, tail suspension, tests for aggressive behaviour and social interactions and the effect of isolation was studied. The results were evaluated and the standard statistics were applied. The said study was done to establish facts that isolation itself impairs social behaviour and can lead to alcohol dependence as well as related drug dependence.

Keywords: social isolation, albino mice, drug dependence, isolation on social behaviour

Procedia PDF Downloads 463
4438 Assessing the Impact of Antiretroviral Mediated Drug-Drug Interactions on Piperaquine Antimalarial Treatment in Pregnant Women Using Physiologically Based Pharmacokinetic Modelling

Authors: Olusola Omolola Olafuyi, Michael Coleman, Raj Kumar Singh Badhan

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Introduction: Malaria in pregnancy has morbidity and mortality implication on both mother and unborn child. Piperaquine (PQ) based antimalarial treatment is emerging as a choice antimalarial for pregnant women in the face of resistance to current antimalarial treatment recommendation in pregnancy. Physiological and biochemical changes in pregnant women may affect the pharmacokinetics of the antimalarial drug in these. In malaria endemic regions other infectious diseases like HIV/AIDs are prevalent. Pregnant women who are co-infected with malaria and HIV/AID are at even more greater risk of death not only due to complications of the diseases but also due to drug-drug interactions (DDIs) between antimalarials (AMT) and antiretroviral (ARVs). In this study, physiologically based pharmacokinetic (PBPK) modelling was used to investigate the effect of physiological and biochemical changes on the impact of ARV mediated DDIs in pregnant women in three countries. Method: A PBPK model for PQ was developed on SimCYP® using published physicochemical and pharmacokinetic data of PQ from literature, this was validated in three customized population groups from Thailand, Sudan and Papua New Guinea with clinical data. Validation of PQ model was also done in presence of interaction with efavirenz (pre-validated on SimCYP®). Different albumin levels and pregnancy stages was simulated in the presence of interaction with standard doses of efavirenz and ritonavir. PQ day 7 concentration of 30ng/ml was used as the efficacy endpoint for PQ treatment.. Results: The median day 7 concentration of PQ remained virtually consistent throughout pregnancy and were satisfactory across the three population groups ranging from 26-34.1ng/ml; this implied the efficacy of PQ throughout pregnancy. DDI interaction with ritonavir and efavirenz resulted in modest effect on the day 7 concentrations of PQ with AUCratio ranging from 0.56-0.8 and 1.64-1.79 for efavirenz and ritonavir respectively over 10-40 gestational weeks, however, a reduction in human serum albumin level reflective of severe malaria resulted in significantly reduced the number of subjects attaining the PQ day 7 concentration in the presence of both DDIs. The model demonstrated that the DDI between PQ and ARV in pregnant women with different malaria severities can alter the pharmacokinetic of PQ.

Keywords: antiretroviral, malaria, piperaquine, pregnancy, physiologically-based pharmacokinetics

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4437 Effects of Tenefovir Disiproxil Fumarate on the Renal Sufficiency of HIV Positive Patients

Authors: Londeka Ntuli, Frasia Oosthuizen

Abstract:

Background: Tenefovir disiproxil fumarate (TDF) is a nephrotoxic drug and has been proven to contribute to renal insufficiency necessitating intensive monitoring and management of adverse effects arising from prolonged exposure to the drug. TDF is one of the preferred first-line drugs used in combination therapy in most regions. There are estimated 300 000 patients being initiated on the Efavirenz/TDF/Emtricitabine first-line regimen annually in South Africa. It is against this background that this study aims to investigate the effects of TDF on renal sufficiency of HIV positive patients. Methodology: A retrospective quantitative study was conducted, analysing clinical charts of HIV positive patient’s older than 18 years of age and on a TDF-containing regimen for more than 1 year. Data were obtained from the analysis of patient files and was transcribed into Microsoft® Excel® spreadsheet. Extracted data were coded, categorised and analysed using STATA®. Results: A total of 275 patient files were included in this study. Renal function started decreasing after 3 months of treatment (with 93.5% patients having a normal EGFR), and kept on decreasing as time progressed with only 39.6% normal renal function at year 4. Additional risk factors for renal insufficiency included age below 25, female gender, and additional medication. Conclusion: It is clear from this study that the use of TDF necessitates intensive monitoring and management of adverse effects arising from prolonged exposure to the drug. The findings from this study generated pertinent information on the safety profile of the drug TDF in a resource-limited setting of a public health institution. The appropriate management is of tremendous importance in the South African context where the majority of HIV positive individuals are on the TDF containing regimen; thus it is beneficial to ascertain the possible level of toxicities these patients may be experiencing.

Keywords: renal insufficiency, tenefovir, HIV, risk factors

Procedia PDF Downloads 116
4436 Health and the Politics of Trust: Multi-Drug-Resistant Tuberculosis in Kathmandu

Authors: Mattia Testuzza

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Public health is a social endeavour, which involves many different actors: from extremely stratified, structured health systems to unofficial networks of people and knowledge. Health and diseases are an intertwined individual and social experiences. Both patients and health workers navigate this public space through relations of trust. Trust in healthcare goes from the personal trust between a patient and her/his doctor to the trust of both the patient and the health worker in the medical knowledge and the healthcare system. Trust it is not a given, but it is continuously negotiated, given and gained. The key to understand these essential relations of trust in health is to recognise them as a social practice, which therefore implies agency and power. In these terms, health is constantly public and made public, as trust emerges as a meaningfully political phenomenon. Trust as a power relation can be observed at play in the implementation of public health policies such as the WHO’s Directly-Observed Theraphy Short-course (DOTS), and with the increasing concern for drug-resistance that tuberculosis pose, looking at the role of trust in the healthcare delivery system and implementation of public health policies becomes significantly relevant. The ethnographic fieldwork was carried out in four months through observation of the daily practices at the National Tuberculosis Center of Nepal, and semi-structured interviews with MultiDrug-Resistant Tuberculosis (MDR-TB) patients at different stages of the treatment, their relatives, MDR-TB specialised nurses, and doctors. Throughout the research, the role which trust plays in tuberculosis treatment emerged as one fundamental ax that cuts through all the different factors intertwined with drug-resistance development, unfolding a tension between the DOTS policy, which undermines trust, and the day-to-day healthcare relations and practices which cannot function without trust. Trust also stands out as a key component of the solutions to unforeseen issues which develop from the overall uncertainty of the context - for example, political instability and extreme poverty - in which tuberculosis treatment is carried out in Nepal.

Keywords: trust, tuberculosis, drug-resistance, politics of health

Procedia PDF Downloads 245
4435 The Effect of Corporate Governance on Financial Stability and Solvency Margin for Insurance Companies in Jordan

Authors: Ghadeer A.Al-Jabaree, Husam Aldeen Al-Khadash, M. Nassar

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This study aimed at investigating the effect of well-designed corporate governance system on the financial stability of insurance companies listed in ASE. Further, this study provides a comprehensive model for evaluating and analyzing insurance companies' financial position and prospective for comparing the degree of corporate governance application provisions among Jordanian insurance companies. In order to achieve the goals of the study, a whole population that consist of (27) listed insurance companies was introduced through the variables of (board of director, audit committee, internal and external auditor, board and management ownership and block holder's identities). Statistical methods were used with alternative techniques by (SPSS); where descriptive statistical techniques such as means, standard deviations were used to describe the variables, while (F) test and ANOVA analysis of variance were used to test the hypotheses of the study. The study revealed the existence of significant effect of corporate governance variables except local companies that are not listed in ASE on financial stability within control variables especially debt ratio (leverage),where it's also showed that concentration in motor third party doesn't have significant effect on insurance companies' financial stability during study period. Moreover, the study concludes that Global financial crisis affect the investment side of insurance companies with insignificant effect on the technical side. Finally, some recommendations were presented such as enhancing the laws and regulation that help the appropriate application of corporate governance, and work on activating the transparency in the disclosures of the financial statements and focusing on supporting the technical provisions for the companies, rather than focusing only on profit side.

Keywords: corporate governance, financial stability and solvency margin, insurance companies, Jordan

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4434 A Single Country Comparative Contextual Description Study of the Executive Authorities in Austria

Authors: Meryl Abigail Lucasan

Abstract:

The purpose of this research paper is to present a Single Country Comparative Contextual Description Study of the Executive Authorities in Austria, focusing with the Federal President, Cabinet members (Federal Chancellor, the Vice-Chancellor and the other Federal Ministers) and the State Government. In this paper, the roles and powers of the executive authorities of Austria will be enumerated and explained; and the behavior of the executive authorities of Austria will be described in detail. In addition, the researcher will provide a survey that was answered by an Austrian citizen through electronic mail to gain more concrete information about the current political condition in Austria. Based on research, Austria has a remarkable political stability. This paper will develop a conceptual framework or a sample paradigm to represent the political system in Austria, focusing on its states and Executive Authorities in achieving political stability.

Keywords: Austrian politics, executive branch of the government, federal government, political stability

Procedia PDF Downloads 259
4433 Encapsulation of Venlafaxine-Dowex® Resinate: A Once Daily Multiple Unit Formulation

Authors: Salwa Mohamed Salah Eldin, Howida Kamal Ibrahim

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Introduction: Major depressive disorder affects high proportion of the world’s population presenting cost load in health care. Extended release venlafaxine is more convenient and could reduce discontinuation syndrome. The once daily dosing also reduces the potential for adverse events such as nausea due to reduced Cmax. Venlafaxine is an effective first-line agent in the treatment of depression. A once daily formulation was designed to enhance patient compliance. Complexing with a resin was suggested to improve loading of the water soluble drug. The formulated systems were thoroughly evaluated in vitro to prove superiority to previous trials and were compared to the commercial extended release product in experimental animals. Materials and Methods: Venlafaxine-resinates were prepared using Dowex®50WX4-400 and Dowex®50WX8-100 at drug to resin weight ratio of 1: 1. The prepared resinates were evaluated for their drug content, particle shape and surface properties and in vitro release profile in gradient pH. The release kinetics and mechanism were evaluated. Venlafaxine-Dowex® resinates were encapsulated using O/W solvent evaporation technique. Poly-ε-caprolactone, Poly(D, L-lactide-co-glycolide) ester, Poly(D, L-lactide) ester and Eudragit®RS100 were used as coating polymers alone and in combination. Drug-resinate microcapsules were evaluated for morphology, entrapment efficiency and in-vitro release profile. The selected formula was tested in rabbits using a randomized, single-dose, 2-way crossover study against Effexor-XR tablets under fasting condition. Results and Discussion: The equilibrium time was 30 min for Dowex®50WX4-400 and 90 min for Dowex®50WX8-100. The percentage drug loaded was 93.96 and 83.56% for both resins, respectively. Both drug-Dowex® resintes were efficient in sustaining venlafaxine release in comparison to the free drug (up to 8h.). Dowex®50WX4-400 based venlafaxine-resinate was selected for further encapsulation to optimize the release profile for once daily dosing and to lower the burst effect. The selected formula (coated with a mixture of Eudragit RS and PLGA in a ratio of 50/50) was chosen by applying a group of mathematical equations according to targeted values. It recorded the minimum burst effect, the maximum MDT (Mean dissolution time) and a Q24h (percentage drug released after 24 hours) between 95 and 100%. The 90% confidence intervals for the test/reference mean ratio of the log-transformed data of AUC0–24 and AUC0−∞ are within (0.8–1.25), which satisfies the bioequivalence criteria. Conclusion: The optimized formula could be a promising extended release form of the water soluble, short half lived venlafaxine. Being a multiple unit formulation, it lowers the probability of dose dumping and reduces the inter-subject variability in absorption.

Keywords: biodegradable polymers, cation-exchange resin, microencapsulation, venlafaxine hcl

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4432 Rupture in the Paradigm of the International Policy of Illicit Drugs in the Field of Public Health and within the Framework of the World Health Organization, 2001 to 2016

Authors: Emy Nayana Pinto, Denise Bomtempo Birche De Carvalho

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In the present study, the harmful use of illicit drugs is seen as a public health problem and as one of the expressions of the social question, since its consequences fall mainly on the poorer classes of the population. This perspective is a counterpoint to the dominant paradigm on illicit drug policy at the global level, whose centrality lies within the criminal justice arena. The 'drug problem' is internationally combated through fragmented approaches that focus its actions on banning and criminalizing users. In this sense, the research seeks to answer the following key questions: What are the influences of the prohibitionism in the recommendations of the United Nations (UN), the World Health Organization (WHO), and the formulation of drug policies in member countries? What are the actors that have been provoking the prospect of breaking with the prohibitionist paradigm? What is the WHO contribution to the rupture with the prohibitionist paradigm and the displacement of the drug problem in the field of public health? The general objective of this work is to seek evidence from the perspective of rupture with the prohibitionist paradigm in the field of drugs policies at the global and regional level, through analysis of documents of the World Health Organization (WHO), between the years of 2001 to 2016. The research was carried out in bibliographical and documentary sources. The bibliographic sources contributed to the approach with the object and the theoretical basis of the research. The documentary sources served to answer the research questions and evidence the existence of the perspective of change in drug policy. Twenty-two documents of the UN system were consulted, of which fifteen had the contribution of the World Health Organization (WHO). In addition to the documents that directly relate to the subject of the research, documents from various agencies, programs, and offices, such as the Joint United Nations Program on HIV/AIDS (UNAIDS) and the United Nations Office on Drugs and Crime (UNODC), which also has drugs as the central or transversal theme of its performance. The results showed that from the 2000s it was possible to find in the literature review and in the documentary analysis evidence of the critique of the prohibitionist paradigm parallel to the construction of a new perspective for drug policy at the global level and the displacement of criminal justice approaches for the scope of public health, with the adoption of alternative and pragmatic interventions based on human rights, scientific evidence and the reduction of social damages and health by the misuse of illicit drugs.

Keywords: illicit drugs, international organizations, prohibitionism, public health, World Health Organization

Procedia PDF Downloads 150
4431 Improving the LDMOS Temperature Compensation Bias Circuit to Optimize Back-Off

Authors: Antonis Constantinides, Christos Yiallouras, Christakis Damianou

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The application of today's semiconductor transistors in high power UHF DVB-T linear amplifiers has evolved significantly by utilizing LDMOS technology. This fact provides engineers with the option to design a single transistor signal amplifier which enables output power and linearity that was unobtainable previously using bipolar junction transistors or later type first generation MOSFETS. The quiescent current stability in terms of thermal variations of the LDMOS guarantees a robust operation in any topology of DVB-T signal amplifiers. Otherwise, progressively uncontrolled heat dissipation enhancement on the LDMOS case can degrade the amplifier’s crucial parameters in regards to the gain, linearity, and RF stability, resulting in dysfunctional operation or a total destruction of the unit. This paper presents one more sophisticated approach from the traditional biasing circuits used so far in LDMOS DVB-T amplifiers. It utilizes a microprocessor control technology, providing stability in topologies where IDQ must be perfectly accurate.

Keywords: LDMOS, amplifier, back-off, bias circuit

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4430 PNIPAAm-MAA Nanoparticles as Delivery Vehicles for Curcumin Against MCF-7 Breast Cancer Cells

Authors: H. Tayefih, F. farajzade ahari, F. Zarghami, V. Zeighamian, N. Zarghami, Y. Pilehvar-soltanahmadi

Abstract:

Breast cancer is the most frequently occurring cancer among women throughout the world. Natural compounds such as curcumin hold promise to treat a variety of cancers including breast cancer. However, curcumin's therapeutic application is limited, due to its rapid degradation and poor aqueous solubility. On the other hand, previous studies have stated that drug delivery using nanoparticles might improve the therapeutic response to anticancer drugs. Poly (N-isopropylacrylamide-co-methacrylic acid) (PNIPAAm–MAA) is one of the hydrogel copolymers utilized in the drug delivery system for cancer therapy. The aim of this study was to examine the cytotoxic potential of curcumin encapsulated within the NIPAAm-MAA nanoparticle, on the MCF-7 breast cancer cell line. In this work, polymeric nanoparticles were synthesized through the free radical mechanism, and curcumin was encapsulated into NIPAAm-MAA nanoparticles. Then, the cytotoxic effect of curcumin-loaded NIPAAm-MAA on the MCF-7 breast cancer cell line was measured by MTT assays. The evaluation of the results showed that curcumin-loaded NIPAAm-MAA has more cytotoxic effect on the MCF-7 cell line and efficiently inhibited the growth of the breast cancer cell population, compared with free curcumin. In conclusion, this study indicates that curcumin-loaded NIPAAm-MAA suppresses the growth of the MCF-7 cell line. Overall, it is concluded that encapsulating curcumin into the NIPAAm-MAA copolymer could open up new avenues for breast cancer treatment.

Keywords: PNIPAAm-MAA, breast cancer, curcumin, drug delivery

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4429 Thermal Effects on Wellbore Stability and Fluid Loss in High-Temperature Geothermal Drilling

Authors: Mubarek Alpkiray, Tan Nguyen, Arild Saasen

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Geothermal drilling operations contain numerous challenges that are encountered to increase the well cost and nonproductive time. Fluid loss is one of the most undesirable troublesome that can cause well abandonment in geothermal drilling. Lost circulation can be seen due to natural fractures, high mud weight, and extremely high formation temperatures. This challenge may cause wellbore stability problems and lead to expensive drilling operations. Wellbore stability is the main domain that should be considered to mitigate or prevent fluid loss into the formation. This paper describes the causes of fluid loss in the Pamukoren geothermal field in Turkey. A geomechanics approach integration and assessment is applied to help the understanding of fluid loss problems. In geothermal drillings, geomechanics is primarily based on rock properties, in-situ stress characterization, the temperature of the rock, determination of stresses around the wellbore, and rock failure criteria. Since a high-temperature difference between the wellbore wall and drilling fluid is presented, temperature distribution through the wellbore is estimated and implemented to the wellbore stability approach. This study reviewed geothermal drilling data to analyze temperature estimation along the wellbore, the cause of fluid loss and stored electric capacity of the reservoir. Our observation demonstrates the geomechanical approach's significant role in understanding safe drilling operations on high-temperature wells. Fluid loss is encountered due to thermal stress effects around the borehole. This paper provides a wellbore stability analysis for a geothermal drilling operation to discuss the causes of lost circulation resulting in nonproductive time and cost.

Keywords: geothermal wells, drilling, wellbore stresses, drilling fluid loss, thermal stress

Procedia PDF Downloads 185