Poly-3-hexylthiophene Nanorods as A Donor for Organic Photovoltaics

Poly-3-hexylthiophene functionalized silsesquioxane nanorods (P3HT-NRs) were prepared by direct hydrolysis and condensation of P3HT-silane precursor using the modified Stöber method. The silane precursor was stirred in a mixture of two solvents in the presence of a base under room temperature for three different reaction times. The size, shape, and morphology of these novel nanostructures were visualized using the transmission electron microscope (TEM) and scanning electron microscope (SEM). The composition of the P3HT-NRs was confirmed by FTIR and its silane by proton NMR. Future work will focus on evaluating photovoltaic performance of these nanorods as a donor for organic photovoltaics

INVESTIGATION OF CAPACITY GAINS IN MIMO CORRELATED RICIAN FADING CHANNELS SYSTEMS

This paper investigate the effect of Rician fading and correlation on the capacity and diversity of MIMO channels. The use of antenna arrays at both sides of the wireless communication link (MIMO systems) can increase channel capacity provided the propagation medium is rich scattering or Rayleigh fading and the antenna arrays at both sides are uncorrelated. However, the presence of line-of-sight (LOS) component and correlation of real world wireless channels may affect the system performance. Along with that we also investigate power distribution methods for higher capacity gains and effect of CSI at the transmitter on the capacity for range of SNR. Our investigation follows capacity gain as function of number of antennas and signal-to-noise (SNR) power ratio Block and frequency nonselective Rician fading channel is assumed, and the effect of Rician factor (L) and the correlation parameter (ρ) on the capacity and diversity gains of MIMO channels are found. Inde

A study of the clinical profile of 50 patients of COPD with correlation between clinical, radiological and spirometric evaluation

Background: Chronic obstructive pulmonary disease (COPD) is a common, preventable and treatable disease that is characterised by persistent respiratory symptoms and airflow limitation that is due to airway and/ or alveolar abnormalities usually caused by significant exposure to noxious particles or gases. Tobacco smoking, occupational exposure to organic and inorganic dusts, chemical agents and fumes and biomass cooking are the risk factors for COPD. Chronic dyspnoea, cough, sputum production, wheezing and chest tightness are the common symptoms of COPD. The present study was undertaken to evaluate the clinical, radiological and spirometric parameters in patients with COPD and to demonstrate a correlation between them.Methods: This was a prospective study of 50 patients of COPD who presented to out- patient department. We included all patients above 40 years of age with a smoking index of 200 or more, or history of exposure to occupational dust, biomass fuel gas or exposure to other obnoxious gases; and who had history of dyspnoea and cough. Spirometry was performed to confirm the diagnosis and to grade the severity of airflow obstruction. History of dyspnoea, cough, sputum production, wheezing, chest tightness, fever, weight loss and the number of exacerbations in the previous year was noted. We then performed a detailed clinical examination. Blood was sent for haemogram and arterial blood gas analysis and all patients underwent an ECG, 2- D Echo and HRCT of the thorax. We then studied the correlation between the clinical, radiological and spirometric profiles in these patients.Results: Out of the 50 patients, majority was between 50-59 years of age, with male to female ratio of 1.94:1.00. History of smoking was present in 74% patients, exposure to biomass fuel in 12% and exposure to occupational dust in 6% patients. Commonest symptom was dyspnoea (in 100% patients) followed by cough (88%), sputum production (68%), wheezing (58%), chest tightness and fever (30%) and weight loss (28%). HRCT was positive in 75% patients, while ECG changes were seen in 42% patients and pulmonary hypertension was present in 54% patients. A significant association was observed between grade 5 dyspnoea on mMRC, hypoxia, hypercarbia, pulmonary hypertension and Gold-5 airflow obstruction.Conclusions: In the present study of 50 cases, COPD was seen predominantly in male patients, with a mean age of presentation between 50- 59 years. Tobacco smoking was the commonest etiological factor. Clinical symptoms most commonly documented were dyspnoea, cough with or without expectoration, wheezing, chest tightness, fever and weight loss. A significant association was observed between grade 5 dyspnoea on mMRC, hypoxia, hypercarbia, pulmonary hypertension and Gold-5 airflow obstruction

A Novel Fibre Composite System to Investigate Tenocyte Metabolism Under Physiological and Pathological Loading Conditions.

PhDTendons are crucial for locomotion, transferring forces from muscle to bone. They are subjected to high forces, and possess highly specialised hierarchical structures to function efficiently. Tendinopathies are debilitating tendon disorders common in both athletes and non-athletes. The unclear aetiology of tendinopathies has led to limited, generalised treatment, with poor regenerative outcomes for patients. Tendinopathies are thought to be instigated by changes in the local cellular environment, with tendon overuse generating matrix microdamage, which increases cellular shear. Shear is potentially an important mechanotransduction cue, but no mechanism is available to investigate this directly. To address this need, a fibre composite system based on polyethylene glycol (PEG) was developed, consisting of cell seeded PEG-peptide fibres encapsulated in a PEG matrix. Composites were developed to mimic the cell mechanical environment in tendons, creating shear-tension ratios equivalent to those seen physiologically (40% of applied strain transferred to the fibres; the remaining 60% as fibre shearing within the matrix). High shear-low tension (~25% tension, ~75% shear) and low shear-high tension (~60% tension, ~40% shear) environments were also developed to investigate non-physiological conditions. Broad spectrum gene expression analysis was performed to determine how different shear-tension ratios affect the behaviour of tenocytes derived from healthy and tendinopathic human tendons. Tendinopathic tenocytes appeared more mechano-sensitive than healthy tenocytes (shear-tension mediated changes in versican, IL-8, TIMP-3, MMP-3 and MMP-13 expression) and showed a distinct basal profile similar to that observed in tendinopathic tissue (lower MMP-3 and higher MMP-13 expression). Further investigation with bovine tenocytes found changing the cell attachment peptide in fibres from RGD to DGEA increased the sensitivity of tenocytes to the local shear-tension environment (shear-mediated changes in scleraxis, MMP-2 and COL-3 expression). This suggests tenocytes are more responsive when attached to collagen-like materials, and consequently that specific integrins are involved in sensing the local shear-tension environment.Arthritis Research U

Development of nuclear magnetic resonance methods for determination of membrane protein structure

Membrane proteins represent over a third of all proteins encoded for by the human genome and play a vital role in the functionality of the cell, by controlling a vast number of cellular processes. With over half of pharmacological drugs targeting membrane proteins, their importance is not to be under estimated. Yet the number of three-dimensional membrane protein structures reported to date falls well short of that of their water soluble counterparts. This discrepancy can directly be attributed to the difficulties involved in studying membrane protein structure due to their hydrophobic nature, resulting in a number of challenges in the production and purification of protein, whilst requiring the use of a suitable membrane mimetic upon extraction from their native membrane. Solid state NMR (ssNMR) as a technique for studying membrane protein structure is well placed in being able to obtain structural information for membrane proteins in “native-like” lamellar bilayer environments but there are challenges involved in preparing suitable samples for analysis. As there is no “one suit fits all” method for preparing membrane protein samples for ssNMR analysis, conditions that result in fully reconstituted protein, that also allow for high resolution structural analysis have to be trialled. This study presents work on sample preparation methods for the reconstitution of the small alpha helical transmembrane (TM) proteins, using the well characterised TM protein Glycophorin A (GpA) as a model peptide. Established biophysical and NMR techniques were used to characterise DMPC lipid embedded peptides prepared using two reconstitution techniques. The limited site specific labelling at key positions of the GpA homodimer was used to evaluate the feasibility of using similar sample preparation and labelling schemes when applied to that of the Bovine Papillomavirus E5 (BPV E5) TM protein, for which no solved three-dimensional structure exists. Characterisation of the DMPC membranes into which membrane proteins where reconstituted was also conducted. To compliment ssNMR analysis of BPV E5, preliminary work on the use of fast tumbling isotropic bicelles to study membrane protein structure by solution NMR is also presented

Effect of metabolized polyethylene terephthalate, vacuum packaging and storage temperature on shelf life of papaya pulp Kalakand (Indian cookie)

The dairy plants are looking for newer products for diversification and value addition. There is scope for the dairy industry to introduce newer products as healthy, convenience and ready to eat foods for capacity utilization and value addition, but because of complex biochemical composition and high water content, milk and milk products act as an excellent culture medium for growth and multiplication of varieties of microorganisms. Vacuum packaging reduces product shrinkage, trim losses by eliminating oxidation and freezer burn resulting it can enhance product quality. Now a day metabolized polyethylene terephthalate (MET PET) with vacuum packaging have a promising role in storage of various value added milk product. The developed value added Kalakand product (Indian cookie) could be stored successfully for 5 days in MET PET packaging material at 4±1°C and when the product was packaged under vacuum the shelf life increased up to 10 days at 4±1°C

Modulation of transmembrane domain interactions in neu receptor tyrosine kinase by membrane fluidity and cholesterol

The activation mechanism of the ErbB family of receptors is of considerable medical interest as they are linked to a number of human cancers, including an aggressive form of breast cancer. In the rat analogue of the human ErbB2 receptor, referred to as Neu, a point mutation in the transmembrane domain (V664E) has been shown to trigger oncogenic transformation. While the structural impact of this mutation has been widely studied in the past to yield models for the active state of the Neu receptor, little is known about the impact of cholesterol on its structure. Given previous reports of the influence of cholesterol on other receptor tyrosine kinases (RTKs), as well as the modulation of lipid composition in cancer cells, we wished to investigate how cholesterol content impacts the structure of the Neu transmembrane domain. We utilized high-resolution magic angle spinning solid-state NMR to measure 13C–13C coupling of selectively labelled probe residues in the Neu transmembrane domain in lipid bilayers containing cholesterol. We observe inter-helical coupling between residues that support helix–helix interactions on both dimerization motifs reported in the literature (A661-XXX-G665 and I659-XXX-V663). We further explore how changes in cholesterol concentration alter transmembrane domain interactions and the properties and mechanics of the bilayer. We interpret our results in light of previous studies relating RTK activity to cholesterol enrichment and/or depletion, and propose a novel model to explain our data that includes the recognition and binding of cholesterol by the Neu transmembrane domain through a putative cholesterol-recognition/interaction amino acid consensus sequence

Probing the molecular architecture of Arabidopsis thaliana secondary cell walls using two- and three-dimensional (13)C solid state nuclear magnetic resonance spectroscopy.

The plant secondary cell wall is a thickened polysaccharide and phenolic structure, providing mechanical strength to cells, particularly in woody tissues. It is the main feedstock for the developing bioenergy and green chemistry industries. Despite the role that molecular architecture (the arrangement of biopolymers relative to each other, and their conformations) plays in dictating biomass properties, such as recalcitrance to breakdown, it is poorly understood. Here, unprocessed dry (13)C-labeled stems from the model plant Arabidopsis thaliana were analyzed by a variety of (13)C solid state magic angle spinning nuclear magnetic resonance methods, such as one-dimensional cross-polarization and direct polarization, two-dimensional refocused INADEQUATE, RFDR, PDSD, and three-dimensional DARR, demonstrating their viability for the study of native polymer arrangements in intact secondary cell walls. All carbon sites of the two main glucose environments in cellulose (previously assigned to microfibril surface and interior residues) are clearly resolved, as are carbon sites of the other major components of the secondary cell wall: xylan and lignin. The xylan carbon 4 chemical shift is markedly different from that reported previously for solution or primary cell wall xylan, indicating significant changes in the helical conformation in these dried stems. Furthermore, the shift span indicates that xylan adopts a wide range of conformations in this material, with very little in the 31 conformation typical of xylan in solution. Additionally, spatial connections of noncarbohydrate species were observed with both cellulose peaks conventionally assigned as "surface" and as "interior" cellulose environments, raising questions about the origin of these two cellulose signals.This work was supported by BBSRC Grant BB/G016240/1, via The BBSRC Sustainable Bioenergy Cell Wall Sugars Programme. The UK 850 MHz solid state NMR Facility was funded by EPSRC Grant EP/F017901/1 and the BBSRC, as well as the University of Warwick, including via partial funding through Birmingham Science City Advanced Materials Projects 1 and 2, by Advantage West Midlands (AWM) and the European Regional Development Fund (ERDF).This is the final published version. It first appeared at http://pubs.acs.org/doi/abs/10.1021/bi501552k