Use of Natural Graphite for an Energy Storage Device

Ever growing high concerns over use of safe and low cost devices have provided a substantial attention on natural materials. As such natural graphite which has been deeply integrated into numerous applications is being received a consideration to be used for electrochemical devices. The main objective of this study is to explore the suitability of Sri Lankan natural graphite to serve in electrochemical double layer capacitors (EDLCs). In order to uplift the safety of the device, a gel polymer electrolyte was used instead of a liquid electrolyte. Two identical electrodes were consisted with Sri Lankan natural graphite as the active material and polyvinylidenefluoride as the binder. To prepare the electrolyte, polyvinylidenefluoride co hexafluoropropylene and magnesium perchlorate were used as the polymer and the salt respectively. Cyclic voltammetry test results show that single electrode specific capacitance is depending on the potential window. The percentage reduction of capacitance with continuous cycling was about 28%. Nyquist plot of EDLC further confirm the capacitive nature at low frequency

Blood Sugar Lowering Effect of Coccinia grandis (L.) J. Voigt: Path for a New Drug for Diabetes Mellitus

Background. Role of herbs in the management and control of diabetes has emerged fast over the years. We assessed the efficacy of Coccinia grandis (locally known as Ken, Kovakka) leaves as a hypoglycemic agent. Methods. Double-blind phase I clinical trial was conducted at the general hospital and a private hospital in Matara in August 2009. All the participants were given a common meal for dinner, and they maintained a 10-hour fasting period. Sixty-one healthy volunteers were given a meal containing 20 g of leaves of Coccinia grandis which was mixed with a measured amount of scraped coconut and table salt for breakfast, and other 61 were given the placebo meal which also contained scraped coconut and salt. Glucose tolerance test was performed blindly for the two groups. Mixed factorial design analysis of variance and student's t-test were applied. Results. Overall blood sugar levels of the experimental group were also significantly lower than those of the control group (F(1,117) 5.56, P < 0.05). Increase in the blood sugar levels from fasting to one hour (F(1,117) 6.77, P < 0.05) and two hours (F(1,117) 5.28, P < 0.05) postprandially was statistically significant for participants who were in the control group than those of in the experimental group. The mean difference of postprandial blood sugar levels (mg/dL) after one hour (20.2, 95% confidence interval, 4.81 to 35.5) and two hours (11.46, 95% confidence interval; 1.03 to 21.9) was statistically significant between the two groups. Conclusions. Coccinia grandis has a blood sugar lowering effect. However further studies are needed to validate our findings

Common mental disorders among adult members of 'left-behind' international migrant worker families in Sri Lanka

BACKGROUND: Nearly one-in-ten Sri Lankans are employed abroad as International migrant workers (IMW). Very little is known about the mental health of adult members in families left-behind. This study aimed to explore the impact of economic migration on mental health (common mental disorders) of left-behind families in Sri Lanka. METHODS: A cross-sectional survey using multistage sampling was conducted in six districts (representing 62% of outbound IMW population) of Sri Lanka. Spouses and non-spouse caregivers (those providing substantial care for children) from families of economic migrants were recruited. Adult mental health was measured using the Patient Health Questionnaire. Demographic, socio-economic, migration-specific and health utilization information were gathered. RESULTS: A total of 410 IMW families were recruited (response rate: 95.1%). Both spouse and a non-spouse caregiver were recruited for 55 families with a total of 277 spouses and 188 caregivers included. Poor general health, current diagnosed illness and healthcare visit frequency was higher in the non-spouse caregiver group. Overall prevalence of common mental disorder (CMD; Depression, somatoform disorder, anxiety) was 20.7% (95%CI 16.9-24.3) with 14.4% (95%CI 10.3-18.6) among spouses and 29.8% (95%CI 23.2-36.4) among non-spouse caregivers. Prevalence of depression (25.5%; 95%CI 19.2-31.8) and somatoform disorder 11.7% (95%CI 7.0-16.3) was higher in non-spouse caregiver group. When adjusted for age and gender, non-returning IMW in family, primary education and low in-bound remittance frequency was associated with CMD for spouses while no education, poor general health and increased healthcare visits was significantly associated in the non-spouse caregiver group. CONCLUSIONS: To our knowledge, this is one of the first studies to explore specific mental health outcomes among adult left-behind family members of IMW through standardized diagnostic instruments in Sri Lanka and in South Asian region. Negative impact of economic migration is highlighted by the considerably high prevalence of CMD among adults in left-behind families. A policy framework that enables health protection whilst promoting migration for development remains a key challenge for labour-sending nations

Impact of pulmonary exposure to gold core silver nanoparticles of different size and capping agents on cardiovascular injury

Background:The uses of engineered nanomaterials have expanded in biomedical technology and consumer manufacturing. Furthermore, pulmonary exposure to various engineered nanomaterials has, likewise, demonstrated the ability to exacerbate cardiac ischemia reperfusion (I/R) injury. However, the influence of particle size or capping agent remains unclear. In an effort to address these influences we explored response to 2 different size gold core nanosilver particles (AgNP) with two different capping agents at 2 different time points. We hypothesized that a pulmonary exposure to AgNP induces cardiovascular toxicity influenced by inflammation and vascular dysfunction resulting in expansion of cardiac I/R Injury that is sensitive to particle size and the capping agent. Methods: Male Sprague–Dawley rats were exposed to 200 μg of 20 or 110 nm polyvinylprryolidone (PVP) or citrate capped AgNP. One and 7 days following intratracheal instillation serum was analyzed for concentrations of selected cytokines; cardiac I/R injury and isolated coronary artery and aorta segment were assessed for constrictor responses and endothelial dependent relaxation and endothelial independent nitric oxide dependent relaxation. Results: AgNP instillation resulted in modest increase in selected serum cytokines with elevations in IL-2, IL-18, and IL-6. Instillation resulted in a derangement of vascular responses to constrictors serotonin or phenylephrine, as well as endothelial dependent relaxations with acetylcholine or endothelial independent relaxations by sodium nitroprusside in a capping and size dependent manner. Exposure to both 20 and 110 nm AgNP resulted in exacerbation cardiac I/R injury 1 day following IT instillation independent of capping agent with 20 nm AgNP inducing marginally greater injury. Seven days following IT instillation the expansion of I/R injury persisted but the greatest injury was associated with exposure to 110 nm PVP capped AgNP resulted in nearly a two-fold larger infarct size compared to naïve. Conclusions: Exposure to AgNP may result in vascular dysfunction, a potentially maladaptive sensitization of the immune system to respond to a secondary insult (e.g., cardiac I/R) which may drive expansion of I/R injury at 1 and 7 days following IT instillation where the extent of injury could be correlated with capping agents and AgNP size.This work was supported by the National Institute of Environmental Health Sciences U19ES019525, U01ES020127, U19ES019544 and East Carolina Universit

Evidence for perinatal and child health care guidelines in crisis settings: can Cochrane help?

<p>Abstract</p> <p>Background</p> <p>It is important that healthcare provided in crisis settings is based on the best available research evidence. We reviewed guidelines for child and perinatal health care in crisis situations to determine whether they were based on research evidence, whether Cochrane systematic reviews were available in the clinical areas addressed by these guidelines and whether summaries of these reviews were provided in Evidence Aid.</p> <p>Methods</p> <p>Broad internet searches were undertaken to identify relevant guidelines. Guidelines were appraised using AGREE and the clinical areas that were relevant to perinatal or child health were extracted. We searched The Cochrane Database of Systematic Reviews to identify potentially relevant reviews. For each review we determined how many trials were included, and how many were conducted in resource-limited settings.</p> <p>Results</p> <p>Six guidelines met selection criteria. None of the included guidelines were clearly based on research evidence. 198 Cochrane reviews were potentially relevant to the guidelines. These reviews predominantly addressed nutrient supplementation, breastfeeding, malaria, maternal hypertension, premature labour and prevention of HIV transmission. Most reviews included studies from developing settings. However for large portions of the guidelines, particularly health services delivery, there were no relevant reviews. Only 18 (9.1%) reviews have summaries in Evidence Aid.</p> <p>Conclusions</p> <p>We did not identify any evidence-based guidelines for perinatal and child health care in disaster settings. We found many Cochrane reviews that could contribute to the evidence-base supporting future guidelines. However there are important issues to be addressed in terms of the relevance of the available reviews and increasing the number of reviews addressing health care delivery.</p

Effect of the gel polymer electrolyte conductivity on the performance of Zn rechargeable cells

Gel polymer electrolytes (GPEs) have been extensively considered for various applications such as primary and rechargeable cells, super capacitors and electrochromic devices. Various strategies have been adopted to enhance their properties so as to develop efficient and effective devices. One such method is to increase the ionic conductivity of the electrolyte. In this study, attempts were made to study the variation of ionic conductivity with salt concentration of a GPE and to evaluate the dependence of performance on conductivity in a rechargeable cell. The composition was optimized by varying the salt concentration. The highest room temperature conductivity of 4.46×10-3 Scm-1 was obtained with the composition 50 PVdF : 100 EC : 100 PC : 80 ZnTf (by weight). The maximum ionic transference number was also obtained with this composition and it was 0.97. Four different cells were fabricated with four different salt concentrations and the best performance was observed with the cell having the GPE of the highest conductivity. This clearly proves that performance of the device depends on the conductivity of the electrolyte

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Effect of Cathode thickness on the performance of the cell Li

Zn/Natural graphite rechargeable cell with an ionic liquid based gel polymer electrolyte

There is an urgent need to fulfill the hunger for energy in an efficient and a safer way. In this context, non-Lithium based energy storage devices have received a noticeable interest. A prime attention has been given on electrolytes as many of the devices are composed with liquid electrolytes which have been later identified as having various problems. Gel polymer electrolytes (GPEs) are considered as viable substituents for liquid electrolytes because they exhibit liquid like conductivities while retaining good mechanical stabilities. To further improve the safety aspects of GPEs, nowadays many studies have been performed with ionic liquids (ILs) in place of solvents on GPEs. The present study was carried out to fabricate a Zn rechargeable cell with natural graphite (NG) cathode and an IL based GPE. The IL, 1-ethyl-3-methylimidazolium trifluoromethanesulfonate (1E3MITF) with the polymer poly(vinyl chloride) (PVC) and the salt zinc trifluoromethanesulfonate (Zn(CF3SO3)2 – ZnTF) were used in preparing the GPE. The electrochemical properties of the GPE were evaluated using electrochemical impedance spectroscopy (EIS) and DC polarization test. The maximum room temperature conductivity of the electrolyte was 3.06 × 10-4 S cm-1. Conductivity of the electrolyte was highly contributed by ions. The cell of the configuration, Zn / GPE / NG was characterized using cyclic voltammetry (CV) test. Initial specific charge was about 2.25 mA h g-1 and during 50 cycles, it had reduced down to 2.15 mA h g-1. Moreover, satisfactory stability was observed during CV test. Further studies are in progress to improve the cell performance