2,031 research outputs found

    Organic dye adsorption on activated carbon derived from solid waste

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    Activated carbon was prepared through a chemical activation of bamboo waste precursor (BMAC) using phosphoric acid as the activating agent at 500°C for 2 h. Batch adsorption studies were carried out for the adsorption of C.I. Reactive Black 5 (RB5) onto the BMAC. The effect of various experimental parameters such as initial dye concentration (50–500 mg/L), contact time (0–32 h), pH (2–12), and temperature (30–50°C) were investigated. Equilibrium data were found to be very well represented by the Freundlich isotherm and a pseudo-second-order model was found to explain the kinetics of RB5 adsorption more effectively. The mechanism of the adsorption process was determined by the intraparticle diffusion model. Thermodynamic parameters such as standard enthalpy (ΔH°), standard entropy (ΔS°), standard free energy (ΔG°), and activation energy were determined. The results indicated that BMAC is a suitable adsorbent material for adsorption of reactive dye from aqueous solutions

    Institutional Framework of the Social Security System in Tanzania: Challenges, Reforms and Elderly Copping Strategies

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    This paper examines the institutional framework of the social security system in Tanzania with special focus on the critical challenges facing the system and some reforms that have been undertaken. Coping strategies of old people with inadequate support from the social security system are also highlighted. Primary data were collected from 160 elderly in Morogoro Urban and Mvomero districts. The respondents were stratified into pensioners and non-pensioners and across gender. Primary data were complemented by interview of key informants and documentary reviews. The approach was basically qualitative analysis. It was found that the formal social security system in Tanzania comprises of five social security pension institutions; each of these traditionally covering a defined category of beneficiaries as per establishment piece of legislature. The system suffers fragmented legal and regulatory framework where schemes report to different ministries. To resolve this problem and enhance efficiency, a coordinating body, the Social Security Regulatory Authority (SSRA) has been established. Most of the products offered by the schemes are similar, albeit there are some variations. Complaints revolved around the inadequacy of benefits and delays in payments. The different strategies adopted by the elderly to cope with poor social security support are outlined. It is recommended that a special pension fund for all elderly (the Elderly Pension Fund- EPF) be established; monthly pension be transferred electronically via mobile phones in order to reduce transaction costs to the elderly; and in order to maintain the purchasing power of the pension beneficiaries an element of pension indexing be considered to accommodate inflationary pressure in the economy like in the case of pension benefits for senior government officials. Keywords: Pension schemes, Elder vulnerability, Social security reform, Coping strategies

    Synthesis and in vitro antidiabetic activity of some alkyl carbazole compounds

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    Purpose: To synthesize some alkyl derivatives of carbazole and evaluate their in vitro inhibitory effect on alpha amylase and alpha glucosidase.Methods: Synthesis of methylcarbazole, ethylcarbazole, propylcarbazole and butylcarbazole was carried out using acid-catalysed alkylation method while in vitro inhibitory assay on alpha amylase and alpha glucosidase enzymes on the  synthesized compounds was evaluated using standard procedures. Acarbose was used as the reference compound.Results: For carbazole, methylcarbazole, ethylcarbazole, propylcarbazole and butylcarbazole, the IC50 values of alpha amylase inhibitory assay were 87.47,  50.23, 47.20, 42.36 and 42.11 μg/mL respectively. IC50 values of alpha  glucosidase inhibitory assay for ethylcarbazole, propylcarbazole and butylcarbazole were 205.30, 153.93 and 152.90 μg/mL, respectively. Carbazole and  methylcarbazole had no inhibitory effect on this enzyme but the reference drug  (acarbose) had a better inhibitory effect towards the two enzymes than the synthesized products.Conclusion: Some alkyl-carbazoles with anti-diabetic effect have been successfully synthesised. Alkylation of carbazole increased the alpha amylase inhibitory effect of carbazole. The inhibitory effect is directly proportional to the chain length of the alkyl group.Keywords: Alkyl carbazole, alpha amylase, alpha glucosidase, synthesi

    Sclerotherapy plus octreotide versus sclerotherapy alone in the management of gastro-oesophageal variceal hemorrhage

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    Background: There are different ways for controlling oesophageal variceal bleed which include pharmacological and endoscopic methods. In this study we compare efficacy of octreotide (50 g/hr for 48 hours) combined with sclerotherapy versus sclerotherapy alone in patients with acute bleeding from gastro-oesophageal varices (GOV).Methods: It was a randomized clinical controlled trial conducted at Aga Khan University Hospital, Karachi, from January 1997 to December 1998. We evaluated the role of octreotide (50 g/hr for 48 hours) combined with sclerotherapy versus sclerotherapy alone in a total of 105 adult cirrhotic patients who had acute bleeding from GOV. Patients were assigned to receive octreotide plus sclerotherapy or sclerotherapy alone. Primary outcome measure was 5-day survival without rebleeding. The hospital stay in days and blood transfusion requirements were also compared in the combined treatment group versus sclerotherapy alone group.Results: Initial control of bleeding was achieved in 46/51 (90.2%) patients who received combined treatment compared to 41/54 (75.9%) patients (p = 0.05) in sclerotherapy alone group. Rebleeding after the first 48 hours was less in the octreotide treated patients 2/46 vs. 8/41 patients (p = 0.003). The octreotide treated patients had a better short term (5 days) survival without rebleeding 44/51 vs. 33/54 (p = 0.003) and shorter hospital stay, 5.31 +/- 3.87 days vs. 6.63 +/- 3.86 (p = 0.008) as compared to sclerotherapy alone group. The blood transfusion requirement was also less in the combined treatment group 3.88 +/- 2.80 vs. 5.37 +/- 3.15 units (p = 0.002).CONCLUSION: 1) The combination of sclerotherapy, and octreotide infusion over 48 hours is more effective than sclerotherapy alone in the treatment of acute variceal bleeding and prevention of early rebleed in cirrhotic patients. 2) It leads to shorter hospital stay and 3) less blood transfusion requirements. 4) Although early survival without rebleeding is improved, the overall mortality at the end of hospitalization period is similar in the two groups of treated patients

    Microfinance Institutions of Bangladesh: The Effects of Credit Risk Management on Credit Performance

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    The main aim of this study is to investigate the effects of credit risk management on the credit performance of microfinance institutions in Bangladesh. For this purpose, an econometric model with a cross-sectional dataset has been taken into account. The primary data is collected from125 officers of 35 microfinance institutions in Bangladesh. Multiple variables namely, credit policy, credit terms, credit appraisals process, credit risk control, credit collection procedures and Institutional factor have been adopted as the components of credit risk management. The data has been collected using a structured questionnaire completed by microfinance institutions officers of different levels in Bangladesh. The study reveals that credit policy, credit risk control, credit collection procedures and Institutional factor have positive effects on credit performance, and they are statistically significant at 5%, 10%, 1% and 1% levels respectively; while credit terms and credit appraisals process have positive but insignificant effects on the credit performance of microfinance institutions. The empirical findings will support the policymakers in restructuring their overall credit risk management strategies to improve and sustainable credit performance. Keywords: Competition, Overlapping credit, Institutional factor, Effects, Insolvenc

    ADIPONECTIN VERSUS THIAZOLIDINEDIONES AND ANGIOTENSIN RECEPTOR BLOCKERS

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    Adipose tissue has gained great attention during the last decade. It represents not only a depot for energy stores, but also releases adipocytokines regulating energy disposal and can therefore be considered from therapeutic point of view. Hypoadiponectemia is an independent threat for development of metabolic syndrome. When subjects treated with antidiabetic (Thiazolidinediones) and antihypertensive (angiotensin receptor blocker) agents , the plasma concentration of adiponectin, the only component of adipocytokines, directly proportional to plasma values of these drugs. The prevalance of hypertension and T2DM is mounting with unprecedented degree in both developing and advanced countries, therefore, there is a dire need to find safer and economical therapeutic regimes for the treatment of these ailments, and intensive research is also underway for this purpose. PPARγ serves as a common link in the actions of ADN, TZDs and ARBs when exerting their effects, and it is responsible for stimulation of adiponectin receptors, thus ultimately enhancing the levels of adiponectin in plasma. This review aims to elucidate the role, link and use of ARBs, ADN and TZDs as a safer and convenient approach for the treatment of these co-morbidities as a unanimous or single remedy from comparative point of view

    Cystathione gamma lyase/hydrogen sulphide pathway up regulation enhances the responsiveness of ?1A and ?1B-adrenoreceptors in the kidney of rats with left ventricular hypertrophy

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    The purpose of the present study was to investigate the interaction between H2S and NO (nitric oxide) in the kidney and to evaluate its impact on the functional contribution of ?1A and ?1B-adrenoreceptors subtypes mediating the renal vasoconstriction in the kidney of rats with left ventricular hypertrophy (LVH). In rats the LVH induction was by isoprenaline administration and caffeine in the drinking water together with intraperitoneal administration of H2S. The responsiveness of ?1A and ?1B to exogenous noradrenaline, phenylephrine and methoxaminein the absence and presence of 5-methylurapidil (5-MeU) and chloroethylclonidine (CEC) was studied. Cystathione gamma lyase (CSE), cystathione ? synthase (CBS), 3-mercaptopyruvate sulphar transferase (3-MST) and endothelial nitric oxide synthase (eNOS) were quantified. There was significant up regulation of CSE and eNOS in the LVH-H2S compared to the LVH group (P<0.05). Baseline renal cortical blood perfusion (RCBP) was increased (P<0.05) in the LVH-H2S compared to the LVH group. The responsiveness of ?1A-adrenergic receptors to adrenergic agonists was increased (P<0.05) after administration of low dose 5-Methylurapidil in the LVH-H2S group while ?1B-adrenergic receptors responsiveness to adrenergic agonists were increased (P<0.05) by both low and high dose chloroethylclonidine in the LVH-H2S group. Treatment of LVH with H2S resulted in up-regulation of CSE/H2S, CBS, and 3-MST and eNOS/NO/cGMP pathways in the kidney. These up regulation of CSE/H2S, CBS, and 3-MST and eNOS/NO/cGMP pathways enhanced the responsiveness of ?1A and ?1B-adrenoreceptors subtypes to adrenergic agonists in LVH-H2S. These findings indicate an important role for H2S in modulating deranged signalling in the renal vasculature resulting from LVH development

    AI-driven optimization of ethanol-powered internal combustion engines in alignment with multiple SDGs: A sustainable energy transition

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    With the escalating requirement for global sustainable energy solutions and the complexities linked with the complete transition to new technologies, internal combustion engines (ICEs) powered with biofuels like ethanol are gaining significance over time. However, problems linked to the performance and emissions of such ICEs necessitate accurate prediction and optimization. The study employed the integration of artificial neural networks (ANN) and multi-level historical design of response surface methodology (RSM) to address these challenges in alignment with the Sustainable Development Goals (SDGs). A single-cylinder spark ignition (SI) engine powered with ethanol-gasoline blends at different loads and speeds was used to gather data. Among six initially trained ANN models, the most efficient model with a regression coefficient (R2) of 0.9952 (training), 0.98579 (validation), 0.98847 (testing), and 0.99307 (overall) was employed to predict outputs such as brake power, brake specific fuel consumption (BSFC), brake thermal energy (BTE), concentration of carbon dioxide (CO2), carbon monoxide (CO), hydrocarbons (HC), and oxides of nitrogen NOx. Predicted outputs were optimized by incorporating RSM. On implementing optimized conditions, it was observed that BP and BTE increased by 19.9%, and 29.8%, respectively. Additionally, CO, and HC emissions experienced substantial reductions of 28.1%, and 40.6%, respectively. This research can help engine producers and researchers make refined decisions and achieve improved performance and emissions. The study directly supports SDG 7, SDG 9, SDG 12, SDG 13, and SGD 17, which call for achieving affordable, clean energy, sustainable industrialization, responsible consumption, and production, taking action on climate change, and partnership to advance the SDGs as a whole respectively

    Effect of combined siRNA of HCV E2 gene and HCV receptors against HCV

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    <p>Abstract</p> <p>Background/Aim</p> <p>Hepatitis C virus (HCV) is a major threat as almost 3% of the world's population (350 million individual) and 10% of the Pakistani population is chronically infected with this virus. RNA interference (RNAi), a sequence-specific degradation process of RNA, has potential to be used as a powerful alternative molecular therapeutic approach in spite of the current therapy of interferon-α and ribavirin against HCV which has limited efficiency. HCV structural gene E2 is mainly involved in viral cell entry via attachment with the host cell surface receptors i.e., CD81 tetraspanin, low density lipoprotein receptor (LDLR), scavenger receptor class B type 1 (SR-B1), and Claudin1 (CLDN1). Considering the importance of HCV E2 gene and cellular receptors in virus infection and silencing effects of RNAi, the current study was designed to target the cellular and viral factors as new therapeutic options in limiting HCV infection.</p> <p>Results</p> <p>In this study the potential of siRNAs to inhibit HCV-3a replication in serum-infected Huh-7 cells was investigated by combined treatment of siRNAs against the HCV E2 gene and HCV cellular receptors (CD81 and LDLR), which resulted in a significant decrease in HCV viral copy number.</p> <p>Conclusion</p> <p>From the current study it is concluded that the combined RNAi-mediated silencing of HCV E2 and HCV receptors is important for the development of effective siRNA-based therapeutic option against HCV-3a.</p

    Design and analysis of a novel tri-band flower-shaped planar antenna for GPS and WiMAX applications

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    This paper presents the design of a tri-band flower-shaped planar monopole antenna operating at three frequencies i.e. 1.576 GHz (GPS), 2.668 GHz and 3.636 GHz (Mobile WiMAX). The radiating element of the antenna is backed by a 1.6 mm thicker FR-4 substrate having a dielectric constant of 4.3. The substrate is backed by a truncated ground plane. The antenna is fed through a 50 Ω microstrip line. The flower shape of the radiating element is derived from the basic circular shape by introducing in it rounded slots of various radii. The upper part of the antenna is flower-shaped while the lower part comprises a microstrip feed line and two branches, each having two ‘leaves’ at the end. The leaves and branches contribute in the impedance matching of the lower (1.576 GHz) and middle (2.668 GHz) frequency bands. The antenna gives an acceptable simulated efficiency >70% in the three frequency bands. Suitable gains of 1.63, 2.59 and 3.23dB are obtained at 1.576 GHz, 2.668 GHz and 3.636 GHz, respectively. The antenna matched with a VSWR<1.2 in the three frequency bands. The prototype of the antenna is fabricated and tested in the laboratory, and good agreement in simulated and measured results is achieved. The proposed design is a visually appealing and may find uses as an external antenna in GPS and WiMAX applications
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