Self-Diffusion of a Polymer Chain in a Melt

Self-diffusion of a polymer chain in a melt is studied by Monte Carlo simulations of the bond fluctuation model, where only the excluded volume interaction is taken into account. Polymer chains, each of which consists of $N$ segments, are located on an $L \times L \times L$ simple cubic lattice under periodic boundary conditions, where each segment occupies $2 \times 2 \times 2$ unit cells. The results for $N=32, 48, 64, 96, 128, 192, 256, 384$ and 512 at the volume fraction $\phi \simeq 0.5$ are reported, where $L = 128$ for $N \leq 256$ and L=192 for $N \geq 384$. The $N$-dependence of the self-diffusion constant $D$ is examined. Here, $D$ is estimated from the mean square displacements of the center of mass of a single polymer chain at the times larger than the longest relaxation time. From the data for $N = 256$, 384 and 512, the apparent exponent $x_{\rm d}$, which describes the apparent power law dependence of $D$ on $N$ as $D \propto N^{- x_{\rm d}}$, is estimated as $x_{\rm d} \simeq 2.4$. The ratio $D \tau / < R_{\rm e}^{2} >$ seems to be a constant for $N = 192, 256, 384$ and 512, where $\tau$ and $<R_{\rm e}^{2}>$ denote the longest relaxation time and the mean square end-to-end distance, respectively.Comment: 4 pages, 3 figures, submitted to J. Phys. Soc. Jp

FRUIT PEEL EXTRACTS WITH POTENTIAL FOR DISSOLVING SIMULATED RENAL STONES IN IN VITRO CONDITIONS

Objective: To evaluate the antiurolithiatic activity of selected fruit peels on simulated renal stones in in vitro conditions.Methods: Simulated renal stones were prepared by homogenous precipitation method. The criterion selected was to estimate the amount of calcium oxalate remaining in the semi-permeable membranes by Kramer and Tisdal method with slight modification. A suitable media was provided by TRIS buffer.Results: The crude methanol extract of Musa sapientum exhibited highest dissolution of calcium oxalate ie.9.15 mg and the percent dissolved was found to be 91.5% in comparison to Malus pumila methanol extract which dissolved 8.96 mg (89.6%) and Punica granatum methanol extract which dissolved 8.0 mg (80.0%). Its activity was comparable with that of standard drug Tamsulosin hydrochloride (400 mg) with a percentage dissolved of about 90.5%.Conclusion: Experimental evidence showed that methanol and aqueous fruit peel extracts of Musa sapientum, Malus pumila, and Punica granatum possess potential antiurolithiatic activity. Their effect is found to be significant and the extracts can be used in the treatment of lithiasis

Tuberculosis: an overview of current literature on types, diagnosis and drug therapy

Tuberculosis (TB) is an airborne infectious disease caused by organisms of the Mycobacterium tuberculosis complex. It is a global problem and increases in case rates are occurring not only in the developing countries of the world but also in several industrialized nations. There has also been an alarming increase in the number and proportion of cases caused by strains of Mycobacterium tuberculosis that are resistant to multiple first-line drugs. The increase in multiple-drug resistant tuberculosis has re-taught physicians about the importance of pursuing and ensuring treatment until cure. In many low-income and middle-income countries, TB continues to be a major cause of morbidity and mortality, and drug-resistant TB is a major concern in many settings. This article offers an overview of types, diagnosis and management of TB

Relationship between Liquidity Risk and Net Interest Margin of Conventional Banks in Bangladesh

Net interest margin (NIM) of a bank depends on several firm-specific factors. The aim of the study was to determine the effect of liquidity risk on the profitability indicating variable NIM of the conventional banks in Bangladesh. Seven banks were analyzed using the annual reports of the banks for the period of 2011 to 2015. Researchers applied descriptive statistics, correlation, and regression analysis to find out the results. The findings of the study provided evidence that cash to asset (CA) ratio had a negative relationship with NIM but a loan to asset (LA) ratio had a positive effect on the NIM. There was also a significant positive relationship between NIM and loan to deposit (LD) ratio. From the regression analysis it was clear that the LD, CA, and LA were able to explain the changes of NIM of the banks.&nbsp; JEL Classifications: G 2

Relationship between Liquidity Risk and Net Interest Margin of Conventional Banks in Bangladesh

Net interest margin (NIM) of a bank depends on several firm-specific factors. The aim of the study was to determine the effect of liquidity risk on the profitability indicating variable NIM of the conventional banks in Bangladesh. Seven banks were analyzed using the annual reports of the banks for the period of 2011 to 2015. Researchers applied descriptive statistics, correlation, and regression analysis to find out the results. The findings of the study provided evidence that cash to asset (CA) ratio had a negative relationship with NIM but a loan to asset (LA) ratio had a positive effect on the NIM. There was also a significant positive relationship between NIM and loan to deposit (LD) ratio. From the regression analysis it was clear that the LD, CA, and LA were able to explain the changes of NIM of the banks

Assessment of genetic diversity of brinjal (Solanum melongena L.) germplasm by RAPD markers

Assessment of genetic diversity in a crop species is prerequisite to its improvement. The use of germplasm with distinct DNA profiles helps to generate genetically diversified breeding populations. The present study was carried out to investigate the genetic diversity in brinjal or eggplant (Solanum melongena L.) using random amplified polymorphic DNA (RAPD). Fifteen brinjal germplasm and three decamer primers were used for random polymorphic DNA assay. A total of 17 fragments were obtained, out of which 12 (70.59%) were polymorphic. Each primer generated 4 to 8 amplified fragments with an average of 5.67 fragments per primer. The highest genetic distance (0.8873) and the lowest genetic identity (0.4118) were observed in Laffa (Elongated) versus Jessore L and Dharola combinations. The lowest genetic distance (0.1525) was observed in several cultivars. The unweighted pair-group method of arithmetic means (UPGMA) dendrogram was constructed from genetic distance and all brinjal cultivars were grouped into five clusters. The genetic diversity of brinjal cultivars reported in this study will be useful when planning future crosses amongst these cultivars

Impact of Internal Factors on the Profitability of Banks: A Case of Commercial Banks in Bangladesh

The internal factors of the bank have a great influence on the profitability of the banks. This study is an effort to disclose the effect of bank’s internal factors on return on equity (ROE), return on asset (ROA), and net interest margin (NIM) of ten selected commercial banks in Bangladesh for the period of 2011-2015. Researchers used descriptive statistics, correlation and regression analysis as statistics tools to find out the results. The findings from descriptive statistics indicate that Eastern Bank Limited was ranked first regarding profitability. The correlation test found that total equity to total asset ratio (TETA) and cost to income ratio (CIR) significantly affects the ROA whereas loan to deposit ratio had significant positive effect on the NIM of the banks. The regression analysis revealed that the independent variables of the banks were significant enough to explain the variation of the dependent variables (ROA, ROE, and NIM) of the study

Conformational Basis for Asymmetric Seeding Barrier in Filaments of Three- and Four-Repeat Tau

*S Supporting Information ABSTRACT: Tau pathology in Alzheimer’s disease is intimately linked to the deposition of proteinacious filaments, which akin to infectious prions, have been proposed to spread via seeded conversion. Here we use double electron−electron resonance (DEER) spectroscopy in combination with extensive computational analysis to show that filaments of three- (3R) and four-repeat (4R) tau are conformationally distinct. Distance measurements between spin labels in the third repeat, reveal tau amyloid filaments as ensembles of known β-strand−turn−β-strand U-turn motifs. Whereas filaments seeded with 3R tau are structurally homogeneous, filaments seeded with 4R tau are heterogeneous, composed of at least three distinct conformers. These findings establish a molecular basis for the seeding barrier between different tau isoforms and offer a new powerful approach for investigating the composition and dynamics of amyloid fibril ensembles