Novel Na+ doped Alq3 hybrid materials for organic light‐emitting diode (OLED) devices and flat panel displays

Pure and Na⁺‐doped Alq₃ complexes were synthesized by a simple precipitation method at room temperature, maintaining a stoichiometric ratio. These complexes were characterized by X‐ray diffraction, Fourier transform infrared (FTIR), UV/Vis absorption and photoluminescence (PL) spectra. The X‐ray diffractogram exhibits well‐resolved peaks, revealing the crystalline nature of the synthesized complexes, FTIR confirms the molecular structure and the completion of quinoline ring formation in the metal complex. UV/Vis absorption and PL spectra of sodium‐doped Alq₃ complexes exhibit high emission intensity in comparison with Alq₃ phosphor, proving that when doped in Alq₃, Na⁺ enhances PL emission intensity. The excitation spectra of the synthesized complexes lie in the range 242–457 nm when weak shoulders are also considered. Because the sharp excitation peak falls in the blue region of visible radiation, the complexes can be employed for blue chip excitation. The emission wavelength of all the synthesized complexes lies in the bluish green/green region ranging between 485 and 531 nm. The intensity of the emission wavelength was found to be elevated when Na⁺ is doped into Alq₃. Because both the excitation and emission wavelengths fall in the visible region of electromagnetic radiation, these phosphors can also be employed to improve the power conversion efficiency of photovoltaic cells by using the solar spectral conversion principle. Thus, the synthesized phosphors can be used as bluish green/green light‐emitting phosphors for organic light‐emitting diodes, flat panel displays, solid‐state lighting technology – a step towards the desire to reduce energy consumption and generate pollution free light. Copyright © 2014 John Wiley & Sons, Ltd.     

Web Resources for Metagenomics Studies

The development of next-generation sequencing(NGS) platforms spawned an enormous volume of data. This explosion in data has unearthed new scalability challenges for existing bioinformatics tools. The analysis of metagenomic sequences using bioinformatics pipelines is complicated by the substantial complexity of these data. In this article, we review several commonly-used online tools for metagenomics data analysis with respect to their quality and detail of analysis using simulated metagenomics data. There are at least a dozen such software tools presently available in the public domain. Among them, MGRAST, IMG/M, and METAVIR are the most well-known tools according to the number of citations by peer-reviewed scientific media up to mid-2015. Here, we describe 12 online tools with respect to their web link, annotation pipelines, clustering methods, online user support, and availability of data storage. We have also done the rating for each tool to screen more potential and preferential tools and evaluated five best tools using synthetic metagenome. The article comprehensively deals with the contemporary problems and the prospects of metagenomics from a bioinformatics viewpoint.     

Fracture resistance to treated teeth using known endodontics techniques in Indian patients

Teeth with crown structure less than 50% can be restored. Therefore, it is of interest to evaluate an in vitro efficacy of Zirconia post, Glass fiber post, polyethylene-woven fiber posts, and Quartz posts. Forty eight recently extracted mandibular first premolar teeth were randomly grouped in to 4 different groups with 12 samples in each group. After endodontic treatment samples in all groups underwent post preparation followed by restoration with respective posts. The mean fracture resistance (Newton) were 463.5 ± 14.3 (Group I) 425.2± 23.5 (group II), 410.4± 18.6 (Group 3) and 385.2 ± 14.2 (group 4). Data shows that Zirconia post had highest fracture resistance compared to other tested groups.     

Cytosine Methylation Dysregulation in Neonates Following Intrauterine Growth Restriction

Background

Perturbations of the intrauterine environment can affect fetal development during critical periods of plasticity, and can increase susceptibility to a number of age-related diseases (e.g., type 2 diabetes mellitus; T2DM), manifesting as late as decades later. We hypothesized that this biological memory is mediated by permanent alterations of the epigenome in stem cell populations, and focused our studies specifically on DNA methylation in CD34+ hematopoietic stem and progenitor cells from cord blood from neonates with intrauterine growth restriction (IUGR) and control subjects.

Methods and Findings

Our epigenomic assays utilized a two-stage design involving genome-wide discovery followed by quantitative, single-locus validation. We found that changes in cytosine methylation occur in response to IUGR of moderate degree and involving a restricted number of loci. We also identify specific loci that are targeted for dysregulation of DNA methylation, in particular the hepatocyte nuclear factor 4α (HNF4A) gene, a well-known diabetes candidate gene not previously associated with growth restriction in utero, and other loci encoding HNF4A-interacting proteins.

Conclusions

Our results give insights into the potential contribution of epigenomic dysregulation in mediating the long-term consequences of IUGR, and demonstrate the value of this approach to studies of the fetal origin of adult disease.     

Anthropometric and body composition characteristics in pre- and postmenopausal Asian Indian women: Santiniketan women study

The present cross-sectional study was aimed to investigate anthropometric and body composition characteristics in pre- and postmenopausal Asian Indian women. A total of 245 healthy women aged 25 to 65 years took part in the study. A random sampling procedure using a local voters' registration list was followed to select the participants. All participants belonged to the Bengalee population and were inhabitants of the Bolpur-Santiniketan area (lying in between 23 degrees 40' north latitude and 87degrees 43' east longitude) West Bengal, India. Before the actual commencement of the study, written information was communicated to select individuals, and an appointment was requested at their respective houses. Anthropometric measures, namely height, weight etc., were collected using standard techniques. Percentages of body fat (%BF) and body mass index (BMI) were measured using an Omron body fat analyser. All subjects were categorized into two groups: premenopausal (Group I; n = 145, mean age = 32.66 +/- 5.75 years) and postmenopausal (Group II; n = 100, mean age = 52.72 +/- 5.62 years). It was observed that 80.00% women were cohabited and 80.82% were housewife with 44.08% of them having an education up to secondary level. Furthermore, 62.45% subjects had monthly family expenditure of > or = 5000 Indian Rupees. One way ANOVA revealed that there was significant group difference for age, age at menarche, MWC, WHR, FM, FFM and %BF across the groups. Intercorrelation matrix (Pearson's correlation) showed that age had significantly positive association with MWC (p < 0.01), MHC (p < 0.05), WHR (p < 0.01), FM (p < 0.01), and %BF (p < 0.01), whereas FFM has had negative association with age. Most interestingly, it was observed that there was significant difference [chi2 (1) = 9.73] for central obesity status across the groups. It seems reasonable to argue that onset of menopause does play a vital role to alter body composition and in turn CVD risk factors.     

Study of photophysical properties of different metal complexes of Alq3

Different metal complexes of Alq₃ (K⁺, Sr²⁺, Ca²⁺ and Mg²⁺) were synthesized by the precipitation method. The characterization of photoluminescence showed that presence of Mg²⁺ ion enhances photoluminescence of Alq₃ phosphor. The emission spectra are observed at 560 nm when excited at a wavelength of 440 nm. The phosphor is excited at a longer wavelength in the blue region of small energy, so that it could be used as lamp phosphor. It is observed that the prepared phosphor AlMgq₅ is more suitable than Alq_3. The ionic radii of K⁺, Sr²⁺, Ca²⁺ and Mg²⁺ ions are in decreasing order. Therefore, the remarkable properties of AlMgq₅ could be considered as promising materials as opto‐ or optoelectronic materials. Copyright © 2012 John Wiley & Sons, Ltd.     

Thermal properties of rhodopsin: insight into the molecular mechanism of dim-light vision

Rhodopsin has developed mechanisms to optimize its sensitivity to light by suppressing dark noise and enhancing quantum yield. We propose that an intramolecular hydrogen-bonding network formed by ～20 water molecules, the hydrophilic residues, and peptide backbones in the transmembrane region is essential to restrain thermal isomerization, the source of dark noise. We studied the thermal stability of rhodopsin at 55 °C with single point mutations (E181Q and S186A) that perturb the hydrogen-bonding network at the active site. We found that the rate of thermal isomerization increased by 1-2 orders of magnitude in the mutants. Our results illustrate the importance of the intact hydrogen-bonding network for dim-light detection, revealing the functional roles of water molecules in rhodopsin. We also show that thermal isomerization of 11-cis-retinal in solution can be catalyzed by wild-type opsin and that this catalytic property is not affected by the mutations. We characterize the catalytic effect and propose that it is due to steric interactions in the retinal-binding site and increases quantum yield by predetermining the trajectory of photoisomerization. Thus, our studies reveal a balancing act between dark noise and quantum yield, which have opposite effects on the thermal isomerization rate. The acquisition of the hydrogen-bonding network and the tuning of the steric interactions at the retinal-binding site are two important factors in the development of dim-light vision.