Impedance Spectroscopic Investigation of the Degraded Dye-Sensitized Solar Cell due to Ageing

This paper investigates the effect of ageing on the performance of dye-sensitized solar cells (DSCs). The electrical characterization of fresh and degraded DSCs is done under AM1.5G spectrum and the current density-voltage (J-V) characteristics are analyzed. Short circuit current density (JSC) decreases significantly whereas a noticeable increase in open circuit voltage is observed. These results have been further investigated electroanalytically using electrochemical impedance spectroscopy (EIS). An increase in net resistance results in a lower JSC for the degraded DSC. This decrease in current is mainly due to degradation of TiO2-dye interface, which is observed from light and dark J-V characteristics and is further confirmed by EIS measurements. A reduction in the chemical capacitance of the degraded DSC is observed, which is responsible for the shifting of Fermi level with respect to conduction band edge that further results in an increase of open circuit voltage for the degraded DSC. It is also confirmed from EIS that the degradation leads to a better contact formation between the electrolyte and Pt electrode, which improves the fill factor of the DSC. But the recombination throughout the DSC is found to increase along with degradation. This study suggests that the DSC should be used under low illumination conditions and around room temperature for a longer life

Prognostic Value of RV Function Before and After Lung Transplantation

AbstractObjectivesWe investigated the effects of lung transplantation on right ventricular (RV) function as well as the prognostic value of pre- and post-transplantation RV function.BackgroundAlthough lung transplantation success has improved over recent decades, outcomes remain a challenge. Identifying predictors of mortality in lung transplant recipients may lead to improved long-term outcomes after lung transplantation.MethodsEighty-nine (age 60 ± 6 years, 58 men) consecutive patients who underwent single or double lung transplantation and had pre- and post-transplantation echocardiograms between July 2001 and August 2012 were evaluated. Echocardiographic measurements were performed before and after lung transplantation. Left ventricular (LV) and RV longitudinal strains were analyzed using velocity vector imaging. Cox proportional prognostic hazard models predicting all-cause death were built.ResultsThere were 46 all-cause (52%) and 17 cardiac (19%) deaths during 43 ± 33 months of follow-up. After lung transplantation, echocardiography showed improved systolic pulmonary artery pressure (SPAP) (50 ± 19 mm Hg to 40 ± 13 mm Hg) and RV strain (−17 ± 5% to −18 ± 4%). No pre-transplantation RV parameter predicted all-cause mortality. After adjustment for age, sex, surgery type, and etiology of lung disease in a Cox proportional hazards model, both post-transplantation RV strain (hazard ratio: 1.13, 95% confidence interval: 1.04 to 1.23, p = 0.005), and post-transplantation SPAP (hazard ratio: 1.03, 95% confidence interval: 1.01 to 1.05, p = 0.011) were independent predictors of all-cause mortality. When post-transplantation RV strain and post-transplantation SPAP were added the clinical predictive model based on age, sex, surgery type, and etiology, the C-statistic improves from 0.60 to 0.80 (p = 0.002).ConclusionsAlterations of RV function and pulmonary artery pressure normalize, and post-transplantation RV function may provide prognostic data in patients after lung transplantation. Our study is based on a highly and retrospectively selected group. We believe that larger prospective studies are warranted to confirm this result

High Prevalence of Abdominal, Intra-Abdominal and Subcutaneous Adiposity and Clustering of Risk Factors among Urban Asian Indians in North India

OBJECTIVE: To assess the prevalence of abdominal obesity including intra-abdominal and subcutaneous adiposity along with other cardiometabolic risk factors in urban Asian Indians living in New Delhi. METHODS: We conducted a cross-sectional epidemiological descriptive study with 459 subjects (217 males and 242 females), representing all socio-economic strata in New Delhi. The anthropometric profile [body mass index (BMI), waist circumference (WC) and skinfold thickness], fasting blood glucose (FBG) and lipid profile were recorded. Percent body fat (%BF), total abdominal fat (TAF), intra-abdominal adipose tissue (IAAT) and subcutaneous abdominal adipose tissue (SCAT) were quantified using predictive equations for Asian Indians. RESULTS: The overall prevalence of obesity was high [by BMI (>25 kg/m(2)), 50.1%]. The prevalence of abdominal obesity (as assessed by WC) was 68.9%, while that assessed by TAF was 70.8%. Increased IAAT was significantly higher in females (80.6%) as compared to males (56.7%) (p = 0.00) with overall prevalence being 69.3%. The overall prevalence of high SCAT was 67.8%, more in males (69.1%) vs. females (66.5%, p = 0.5). The prevalence of type 2 diabetes, the metabolic syndrome and hypertension was 8.5%, 45.3% and 29.2%, respectively. Hypertriglyceridemia, hypercholesterolemia and low levels of HDL-c were prevalent in 42.7%, 26.6% and 37% of the subjects, respectively. The prevalence of hypertriglyceridemia was significantly higher in males (p = 0.007); however, low levels of HDL-c were more prevalent in females as compared to males (p = 0.00). CONCLUSION: High prevalence of generalized obesity, abdominal obesity (by measurement of WC, TAF, IAAT and SCAT) and dysmetabolic state in urban Asian Indians in north India need immediate public health intervention

Smt NHL Municipal Medical College,Ahmedabad

mass whereas pseudocyst is the commonest benign mass in the pancreas. However our aim is to highlight multidetector computed tomographic (MDCT) features of uncommon masses so as to diagnose them correctly. Material and Methods-20 patients were studied during July 2011 to December 2012. Plain and intravenous contrast scan with arterial and portal venous phases were obtained. Masses were classified as solid or cystic and diagnosis was confirmed by correlating with clinical findings, FNAC or postoperatively. Results-M: F-1:1.2. Age group-16-75yrs. Masses classified as solid in 8 patients (40%) and cystic in 12 (60%). Solid masses included neuroendocrinal tumors (62.5%); metastasis (25%) and chronic inflammatory mass (12.5%). Cystic masses were mucinous cystadenoma (37.3%), serous cystadenoma (25%), simple cyst (16.6%), intraductal papillary mucinous tumor, pancreatic tuberculosis and mucinous cystadenomacarcinoma in 8.3 % each. Cystic masses were common in females 64.4 % as compared to 55.5 % in males. Pancreatic endocrine masses were characteristically hypervascular on arterial phase. Metastasis was seen from renal cell carcinoma and lung mass. Mucinous cystadenoma were the commonest cystic masses measuring more than10-12 cms with multiple septa, internal cyst varying <6-7 in number and size>2cms. Serous cystadenoma were approximately 5-6 cms in size with small internal cysts <2cms with septations. Cysts associated with syndromes like von Hippel Lindau and polycystic kidney disease and pancreatic tuberculosis was seen in one patient each. Conclusion: Uncommon pancreatic masses have characteristic features which help in triage and prognosis of the patients

Influence of Khasi Language on Nasal and Oral Passages in English: A Nasometric Study

Introduction Speech is a overlaid function of respiratory, phonatory, resonatory, articulatory systems . Nasalance can be defined as the relative amounts of oral and nasal acoustic energy in speech done by modification of oral and nasal cativities that is complex activity of the resonator system. Nasometer was developed by Samuel Fletcher, Larry Adams, and Martin McCutcheon at the University is a computer based instrument facilitating accurate analysis of signal yielding nasalance scores. There is no report regarding nasalence score variance in khasi language speakers speaking English. Materials and Methods The study aims at analysing and measuring nasalence score in Khasi speakers reading English passages. A total of 5 female subjects were chosen who were native speakers of khasi language and who had exposure of English language since childhoods were selected. Nasometer II Model 6400 (Software version 2.6) of Key Elemetrics Corporation was used. Three standardized passages (Zoo passage, Rainbow passage and nasal sentences) were used for the study. Results The mean nasalance scores obtained for zoo, rainbow and nasal sentences in female were 19.39± 12.21 SD, 38.13 ± 14.83 SD, 68.33 ± 15.29 SD and 18.26 ± 3.53 SD, 33.13 ± 1.68 SD, 63.20 ± 88 SD respectively. Standard norms show significant differences in nasalance scores obtained for Zoo, Rainbow and Nasal Sentences. Paired t-test was used for comparison among the sentences and computation of data show more significant differences for nasal sentences as compared to zoo and rainbow sentences, that is significant (p>0.05). Rainbow sentences revealed more nasalance scores than zoo sentences (p>0.05) i.e. level of significance. Conclusion The reported normative Nasalance data can be used by several voice clinicians for assessing resonance quantitively for khasi speakers using austrioasiatic language