Reduction of Hysteresis in Hybrid Perovskite Transistors by Solvent-Controlled Growth

The effect of crystallization process speed on the morphology of solution-processed methyl ammonium lead iodide (MAPbI₃) thin films is investigated. Crystallization speed is controlled by varying the number of annealing steps, temperature, and resting time between steps. The resting period allows solvent-controlled growth (SCG) in which crystallization progresses slowly via an intermediate phase—during which solvents slowly evaporate away from the films. SCG results in fewer residues, fewer pinholes, and larger grain sizes. Consequently, thin-film transistors with SCG MAPbI₃ exhibit smaller hysteresis in their current-voltage characteristics than those without, demonstrating the benefits of SCG toward hysteresis-free perovskite devices.     

Prevalence of,and risk factors for,symptomatic pelvic organ prolapse in Rural Bangladesh: a cross-sectional survey study

Introduction and hypothesis

The prevalence of symptomatic pelvic organ prolapse (POP), diagnosed by a pre-tested structured questionnaire, is unknown in Bangladesh. We investigated the prevalence of, and risk factors for, symptomatic POP in women in rural Bangladesh, recruited from the community.

Methods

A cross-sectional survey of 787 women aged over 15 years was conducted in four villages in one district in rural Bangladesh. The prevalence of symptomatic POP and the risk factors associated with the condition was investigated, using Chi-squared and multivariate logistic regression.

Results

The prevalence of symptomatic POP was 15.6 %. The mean age of participants was 40.1 (±9.0) years. Women aged 35–44 years (odds ratio [OR] 1.96, 95 % confidence interval [CI] 1.03–3.73) and ≥45 years (OR 2.95, 95 % CI 1.62–5.38) were more likely to have POP compared with women aged ≤35 years. Having POP was positively associated with women having ≥5 children (OR 4.34, 95 % CI 1.39–13.58), having chronic obstructive pulmonary disease (COPD; OR 2.07, 95 % CI 1.02–4.21), and women having constipation (OR 3.54, 95 % CI 1.87–6.72). Women whose husband had >5 years of schooling were less likely to have POP (OR 0.37, 95 % CI 0.19–0.73) compared with women whose husband had no schooling.

Conclusions

Symptomatic POP affects a substantial proportion of women in rural Bangladesh and increases with age. Parity, COPD, constipation and husband’s education are associated with POP, all of which have the potential to be modified. Thus, interventions targeting these risk factors to prevent the condition are urgently needed in Bangladesh.

     

Role of neurotoxicants in the pathogenesis of Alzheimer’s disease: a mechanistic insight

Alzheimer’s disease (AD) is the most conspicuous chronic neurodegenerative syndrome, which has become a significant challenge for the global healthcare system. Multiple studies have corroborated a clear association of neurotoxicants with AD pathogenicity, such as Amyloid beta (Aβ) proteins and neurofibrillary tangles (NFTs), signalling pathway modifications, cellular stress, cognitive dysfunctions, neuronal apoptosis, neuroinflammation, epigenetic modification, and so on. This review, therefore, aimed to address several essential mechanisms and signalling cascades, including Wnt (wingless and int.) signalling pathway, autophagy, mammalian target of rapamycin (mTOR), protein kinase C (PKC) signalling cascades, cellular redox status, energy metabolism, glutamatergic neurotransmissions, immune cell stimulations (e.g. microglia, astrocytes) as well as an amyloid precursor protein (APP), presenilin-1 (PSEN1), presenilin-2 (PSEN2) and other AD-related gene expressions that have been pretentious and modulated by the various neurotoxicants. This review concluded that neurotoxicants play a momentous role in developing AD through modulating various signalling cascades. Nevertheless, comprehension of this risk agent-induced neurotoxicity is far too little. More in-depth epidemiological and systematic investigations are needed to understand the potential mechanisms better to address these neurotoxicants and improve approaches to their risk exposure that aid in AD pathogenesis.

Key messages

• Inevitable cascade mechanisms of how Alzheimer’s Disease-related (AD-related) gene expressions are modulated by neurotoxicants have been discussed.
• Involvement of the neurotoxicants-induced pathways caused an extended risk of AD is explicited.
• Integration of cell culture, animals and population-based analysis on the clinical severity of AD is addressed.

     

Complete genomic analysis of a Bangladeshi G1P[8] rotavirus strain detected in 2003 reveals a close evolutionary relationship with contemporary human Wa-like strains

More than 120 variants of rotavirus strains with different VP7 (G type) and VP4 (P type) combinations are reported thus far. Among them Wa-like G1P[8] rotaviruses are the most common human strains worldwide. However, characterization of their entire genome complement is limited to a few old prototype strains, and no complete genome data for any G1P[8] strain isolated in the last decade are available. Both the currently licensed rotavirus vaccines Rotarix? and RotaTeq? possess the G1 and P[8] specificities. Therefore, comprehensive genetic information of the currently circulating G1P[8] strain is important to assess the impact of rotavirus vaccines on the circulating rotavirus strains. Here we report the complete genome sequence of a G1P[8] rotavirus strain Dhaka16-03 isolated in 2003 from a Bangladeshi child hospitalized with severe diarrhea. Based on a full-genome classification system, Dhaka16-03 was shown to posses the typical Wa-like genotype constellation: G1-P[8]-I1-R1-C1-M1-A1-N1-T1-E1-E1-H1. The strain was phylogenetically more closely related to contemporary human rotavirus strains (isolated in the 2000s) with a range of G and P-genotypes than to those of the prototype G1P[8] strains. Since the vaccine strains are developed based on strains isolated several decades ago, it is important to know how much the vaccine strains differ from the currently circulating G1P[8] and other Wa-like strains. Our complete genome characterization of a recent G1P[8] strain will be helpful to assess the ongoing rotavirus vaccine trials and their implementation programs in the forthcoming years.     

Prospective Comparison of Eubacterial PCR and Measurement of Procalcitonin Levels with Blood Culture for Diagnosing Septicemia in Intensive Care Unit Patients

Rapid identification of infection has a major impact on the clinical course, management, and outcome of critically ill intensive care unit (ICU) patients. We compared the results of PCR and procalcitonin with blood culture for ICU patients suspected of having septicemia. Ninety patients (60 patients meeting the criteria for sepsis and 30 patients not meeting the criteria for sepsis) were evaluated. Compared with blood culture as the gold standard, the sensitivity, specificity, and positive and negative predictive values for PCR were 100%, 43.33%, 46.87%, and 100%, respectively, and for procalcitonin were 100%, 61.66%, 56.6%, and 100%, respectively. The average times required to produce a final result were as follows: PCR, 10 h; blood culture, 33 h; procalcitonin, 45 min. Both PCR and procalcitonin may be useful as rapid tests for detecting septicemia but compared with blood cultures lacked specificity.A rapid and reliable system to detect bacteria in the bloodstream would be clinically useful as it could guide early appropriate antibiotic treatment and result in improved patient survival (14). The gold standard for the diagnosis of infection is the isolation and identification of organisms by culture (27). This process usually requires 24 h or more. A large proportion of patients suspected of having septicemia have negative blood cultures (3) due to either previous antibiotic treatment, samples of small volume, transient bacteremias, or sepsis of nonbacterial origin (8, 30). Given the slowness and low sensitivity of blood culture, there is a need for more-rapid and more-sensitive techniques. PCR, which amplifies characteristic genes of microorganisms, is one such technique. In clinical conditions with diverse etiological agents in sterile sites, e.g., blood in sepsis, a broad-range bacterial PCR which uses a primer pair aimed at highly conserved DNA coding regions on bacterial rRNA can be used (8, 10, 11, 20). This is described as eubacterial PCR as well as broad-range bacterial PCR as it detects an rRNA gene component present in all bacteria. PCR cannot differentiate DNA sequences from viable and nonviable bacteria. The value of this test may be enhanced if it is coupled with a host response biomarker indicative of infection and systemic inflammation. Procalcitonin is one such marker and is gaining increasing importance in identification of sepsis (1, 15, 16). Procalcitonin levels are undetectable in healthy individuals but increase in patients with bacterial sepsis and correlate well with the severity of the illness (5, 19, 29).The aim of this study was to compare the results for eubacterial PCR and procalcitonin with blood culture in intensive care unit (ICU) patients suspected of having septicemia.     

Ku70, an essential gene, modulates the frequency of rAAV-mediated gene targeting in human somatic cells

Gene targeting has two important applications. One is the inactivation of genes ("knockouts"), and the second is the correction of a mutated allele back to wild-type ("gene therapy"). Central to these processes is the efficient introduction of the targeting DNA into the cells of interest. In humans, this targeting is often accomplished through the use of recombinant adeno-associated virus (rAAV). rAAV is presumed to use a pathway of DNA double-strand break (DSB) repair termed homologous recombination (HR) to mediate correct targeting; however, the specifics of this mechanism remain unknown. In this work, we attempted to generate Ku70-null human somatic cells by using a rAAV-based gene knockout strategy. Ku70 is the heterodimeric partner of Ku86, and together they constitute an end-binding activity that is required for a pathway [nonhomologous end joining (NHEJ)] of DSB repair that is believed to compete with HR. Our data demonstrated that Ku70 is an essential gene in human somatic cells. More importantly, however, in Ku70(+/-) cells, the frequency of gene targeting was 5- to 10-fold higher than in wild-type cells. RNA interference and short-hairpinned RNA strategies to deplete Ku70 phenocopied these results in wild-type cells and greatly accentuated them in Ku70(+/-) cell lines. Thus, Ku70 protein levels significantly influenced the frequency of rAAV-mediated gene targeting in human somatic cells. Our data suggest that gene-targeting frequencies can be significantly improved in human cells by impairing the NHEJ pathway, and we propose that Ku70 depletion can be used to facilitate both knockout and gene therapy approaches.     

Cytotoxicity of the rhizome of medicinal plants

Objective

To investigate the cytotoxicity of the crude ethanol extract of the rhizome of Zingiber zerumbet (Z. zerumbet) (L) Smith. and Curcuma zedoaria (C. zedoaria) Rosc. against Artemia salina Leach.

Methods

Fresh rhizomes of Z. zerumbet (L) Smith. and C. zedoaria Rosc. were extracted separately in cold with ethanol (2.5 L) and after concentration a brownish syrupy suspension of ethanol extracts of Z. zerumbet (L) Smith. and C. zedoaria Rosc. was obtained. The cytotoxic effect of the crude ethanol extracts of both plants was determined by brine shrimp lethality bioassay.

Results

Crude ethanol extracts of the rhizome of Z. zerumbet (L) Smith. showed the highest cytotoxicity (LC₅₀ was 1.24 µg/mL) against brine shrimp nauplii as compared with C. zedoaria Rosc. (LC₅₀ was 33.593 µg/mL) after 24 h of exposure.

Conclusions

It can be concluded that the rhizome of Z. zerumbet (L) Smith. and C. zedoaria Rosc. can be used as a source of cytotoxic agent.     

Comparison of the prevalence of metabolic syndrome and its association with diabetes and cardiovascular disease in the rural population of Bangladesh using the modified National Cholesterol Education Program Expert Panel Adult Treatment Panel III and International Diabetes Federation definitions

Aims/Introduction

To compare the prevalence of metabolic syndrome (MS) using the modified National Cholesterol Education Program Adult Treatment Plan III (NCEP) and the International Diabetes Federation (IDF) definitions and, using both definitions, determine and compare the association of MS, prediabetes, type 2 diabetes, hypertension (HTN) and cardiovascular disease risk (CVD).

Materials and Methods

A total of 2,293 randomly selected participants (aged ≥20 years) in a rural community in Bangladesh were investigated in a population-based cross-sectional study. Sociodemographic and anthropometric characteristics, blood pressure, blood glucose, and lipid profiles were studied. Age-adjusted data for MS and cardiometabolic risk factors were assessed, and their relationships were examined.

Results

The age-adjusted prevalence of MS was 30.7% (males 30.5%; females 30.5%) using the NCEP definition, and 24.5% (males 19.2%, females 27.5%) using the IDF definition. The prevalence of MS using the NCEP definition was also higher in study participants with prediabetes, type 2 diabetes, HTN and CVD risk. The agreement rate between both definitions was 92% (k = 0.80). The NCEP definition had a stronger association with type 2 diabetes and HTN (odds ratio 12.4 vs 5.2; odds ratio 7.0 vs 4.7, respectively) than the IDF definition. However, the odds ratios for prediabetes and CVD risk were not significantly different.

Conclusions

The prevalence of MS was higher using the NCEP definition, and was more strongly associated with prediabetes, type 2 diabetes, HTN and CVD in this Bangladeshi population.