Biomimetic synthesis of a water soluble conducting molecular complex of polyaniline and lignosulfonate

A new biomimetic route for the synthesis of a conducting molecular complex of polyaniline (Pani) and a natural polyelectrolyte, lignosulfonate (LGS) is presented. A poly(ethylene glycol) modified hematin (PEG-hematin) was used to catalyze the polymerization of aniline in the presence of LGS to form a Pani/LGS complex. UV-vis, FTIR, conductivity and TGA studies for the LGS-polyaniline complex indicate the presence of a thermally stable and electrically conductive form of polyaniline. Also the presence of LGS in this complex, an inexpensive byproduct from pulp processing, provides a unique combination of properties such as electronic conductivity, processability and biodegradability. The use of this conductive complex for corrosion protection is also proposed.     

A Bayesian framework for combining gene predictions

MOTIVATION: Gene identification and gene discovery in new genomic sequences is one of the most timely computational questions addressed by bioinformatics scientists. This computational research has resulted in several systems that have been used successfully in many whole-genome analysis projects. As the number of such systems grows the need for a rigorous way to combine the predictions becomes more essential. RESULTS: In this paper we provide a Bayesian network framework for combining gene predictions from multiple systems. The framework allows us to treat the problem as combining the advice of multiple experts. Previous work in the area used relatively simple ideas such as majority voting. We introduce, for the first time, the use of hidden input/output Markov models for combining gene predictions. We apply the framework to the analysis of the Adh region in Drosophila that has been carefully studied in the context of gene finding and used as a basis for the GASP competition. The main challenge in combination of gene prediction programs is the fact that the systems are relying on similar features such as cod on usage and as a result the predictions are often correlated. We show that our approach is promising to improve the prediction accuracy and provides a systematic and flexible framework for incorporating multiple sources of evidence into gene prediction systems.     

The discovery of a new class of large-conductance Ca2+-activated K+ channel opener targeted for overactive bladder: synthesis and structure-activity relationships of 2-amino-4-azaindoles

2-Amino-4-azaindoles have been identified as a structurally novel class of BK(Ca) channel openers. Their synthesis from 2-chloro-3-nitropyridine is described together with their in vitro properties assessed by 86Rb(+) efflux and whole-cell patch-clamp assays using HEK293 cells stably transfected with the BK(Ca) alpha subunit. In vitro functional characterization of BK(Ca) channel opening activity was also assessed by measurement of relaxation of smooth muscle tissue strips obtained from Landrace pig bladders. The preliminary SAR data indicate the importance of steric bulk around the 2-amino substituent.     

TB Treatment Delays in Odisha,India: Is It Expected Even after These Many Years of RNTCP Implementation?

Background

In India, the Revised National TB Control Programme (RNTCP) envisages initiation of TB treatment within seven days of diagnosis among smear-positive patients. After nearly two decades of RNTCP implementation, treatment delays are usually not expected.

Objectives

To determine the proportion of sputum smear-positive TB patients who were initiated on treatment after seven days and their associated risk factors.

Methods

The study was conducted in Cuttack and Rayagada districts of Odisha. It was a retrospective cohort study that involves review of TB treatment registers and laboratory registers for 2013.

Results

Among 1,800 pulmonary TB (PTB) patients, 1,074 (60%) had been initiated on treatment within seven days of diagnosis, 721 (40%) had been initiated on treatment more than seven days, and 354 (20%) had delays of more than 15 days. The mean duration between TB diagnosis and treatment initiation was 21 days with a range of 8–207 days (median = 14 days). Odds of treatment delay of more than seven days were 4.9 times (95% confidence interval [CI] 3.3-6.6) among those who had been previously treated, 6.2 times (95% CI 1.3-29.7) among those infected with HIV, and 1.8 times (95% CI 1.1-2.9) among those diagnosed outside district DMC.

Conclusion

Delay in initiation of TB treatment occurred in majority of the smear-positive patients. The RNTCP should focus on core areas of providing quality TB services with time-tested strategies. To have real-time monitoring mechanisms for diagnosed smear-positive TB patients is expected to be the way forward.     

Short LOV Proteins in Methylocystis Reveal Insight into LOV Domain Photocycle Mechanisms

Light Oxygen Voltage (LOV) proteins are widely used in optogenetic devices, however universal signal transduction pathways and photocycle mechanisms remain elusive. In particular, short-LOV (sLOV) proteins have been discovered in bacteria and fungi, containing only the photoresponsive LOV element without any obvious signal transduction domains. These sLOV proteins may be ideal models for LOV domain function due to their ease of study as full-length proteins. Unfortunately, characterization of such proteins remains limited to select systems. Herein, we identify a family of bacterial sLOV proteins present in Methylocystis. Sequence analysis of Methylocystis LOV proteins (McLOV) demonstrates conservation with sLOV proteins from fungal systems that employ competitive dimerization as a signaling mechanism. Cloning and characterization of McLOV proteins confirms functional dimer formation and reveal unexpected photocycle mechanisms. Specifically, some McLOV photocycles are insensitive to external bases such as imidazole, in contrast to previously characterized LOV proteins. Mutational analysis identifies a key residue that imparts insensitivity to imidazole in two McLOV homologs and affects adduct decay by two orders of magnitude. The resultant data identifies a new family of LOV proteins that indicate a universal photocycle mechanism may not be present in LOV proteins.     

Reduction of nitric oxide level leads to spontaneous resumption of meiosis in diplotene-arrested rat oocytes cultured in?vitro

The present study was aimed to investigate whether a decrease of nitric oxide (NO) level is beneficial for sponateous resumptiom of meiosis in diplotene-arrested oocytes cultured in vitro. For this purpose, diplotene-arrested oocytes were collected from ovary of immature female rats after a single subcutaneous injection of 20 IU pregnant mare’s serum gonadotropins (PMSG) for 48 h. In vitro effects of S-nitroso-l-acetyl penicillamine (SNAP; an NO donor) and aminoguanidine (AG; an inducible NOS [iNOS] inhibitor), intracellular NO, cyclic guanosine monophosphate (cGMP), Cdc25B, Thr-14/Tyr-15 and Thr-161 phosphorylated cyclin-dependent kinase-1 (CDK1), and cyclin B1 levels were analyzed. The SNAP inhibited spontaneous meiotic resumption form diplotene arrest in a concentration-dependent manner, while AG-induced meiotic resumption form diplotene in 0.1 mmol/L 3-isobutyl-1-methylxanthine (IBMX)-treated oocytes in a concentration-dependent manner. The intracellular NO as well as cGMP levels were decreased significantly during spontaneous meiotic resumption from diplotene arrest. The reduction of Cdc25B expression level was associated with the accumulation of Thr-14/Tyr-15 phosphorylated CDK1 level. However, Thr-161 phosphorylated CDK1 as well as cyclin B1 levels were reduced significantly during meiotic resumption from diplotene arrest. Taken together, these data suggest that the inhibition of iNOS expression leads to a decrease of NO and cGMP levels thereby decreasing Cdc25B level. The reduced CDC25 B level leads to accumulation of Thr-14/Tyr-15 phosphorylated CDK1 level. As a result, Thr-161 phosphorylated CDK1 as well as cyclin B1 levels are decreased leading to maturation-promoting factor (MPF) inactivation. The inactive MPF finally induced meiotic resumption from diplotene stage in rat oocytes cultured in vitro.     

Genetic Diversity in Lens Species Revealed by EST and Genomic Simple Sequence Repeat Analysis

Low productivity of pilosae type lentils grown in South Asia is attributed to narrow genetic base of the released cultivars which results in susceptibility to biotic and abiotic stresses. For enhancement of productivity and production, broadening of genetic base is essentially required. The genetic base of released cultivars can be broadened by using diverse types including bold seeded and early maturing lentils from Mediterranean region and related wild species. Genetic diversity in eighty six accessions of three species of genus Lens was assessed based on twelve genomic and thirty one EST-SSR markers. The evaluated set of genotypes included diverse lentil varieties and advanced breeding lines from Indian programme, two early maturing ICARDA lines and five related wild subspecies/species endemic to the Mediterranean region. Genomic SSRs exhibited higher polymorphism in comparison to EST SSRs. GLLC 598 produced 5 alleles with highest gene diversity value of 0.80. Among the studied subspecies/species 43 SSRs detected maximum number of alleles in L. orientalis. Based on Nei’s genetic distance cultivated lentil L. culinaris subsp. culinaris was found to be close to its wild progenitor L. culinaris subsp. orientalis. The Prichard’s structure of 86 genotypes distinguished different subspecies/species. Higher variability was recorded among individuals within population than among populations.     

Parameter determination and validation for a mechanistic model of the enzymatic saccharification of cellulose‐Iβ

Cost‐effective production of fuels and chemicals from lignocellulosic biomass often involves enzymatic saccharification, which has been the subject of intense research and development. Recently, a mechanistic model for the enzymatic saccharification of cellulose has been developed that accounts for distribution of cellulose chain lengths, the accessibility of insoluble cellulose to enzymes, and the distinct modes of action of the component cellulases [Griggs et al. (2012) Biotechnol. Bioeng., 109(3):665–675; Griggs et al. (2012) Biotechnol. Bioeng., 109(3):676–685]. However, determining appropriate values for the adsorption, inhibition, and rate parameters required further experimental investigation. In this work, we performed several sets of experiments to aid in parameter estimation and to quantitatively validate the model. Cellulosic materials differing in degrees of polymerization and crystallinity (α‐cellulose‐I_β and highly crystalline cellulose‐I_β) were digested by component enzymes (EG_I/CBH_I/ ) and by mixtures of these enzymes. Based on information from the literature and the results from these experiments, a single set of model parameters was determined, and the model simulation results using this set of parameters were compared with the experimental data of total glucan conversion, chain‐length distribution, and crystallinity. Model simulations show significant agreement with the experimentally derived glucan conversion and chain‐length distribution curves and provide interesting insights into multiple complex and interacting physico‐chemical phenomena involved in enzymatic hydrolysis, including enzyme synergism, substrate accessibility, cellulose chain length distribution and crystallinity, and inhibition of cellulases by soluble sugars. © 2015 American Institute of Chemical Engineers Biotechnol. Prog., 31:1237–1248, 2015