Analysis of electrodeposited CdTe thin films grown using cadmium chloride precursor for applications in solar cells

Deposition of cadmium telluride (CdTe) from cadmium chloride (CdCl2) and tellurium oxide has been achieved by electroplating technique using two-electrode configuration. Cyclic voltammetry shows that near-stoichiometric CdTe is achievable between 1330 and 1400 mV deposition voltage range. The layers grown were characterised using X-ray diffraction (XRD), UV–Visible spectrophotometry, scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDX), photoelectrochemical (PEC) cell and DC conductivity measurements. The XRD shows that the electrodeposited CdTe layer is polycrystalline in nature. The UV–Visible spectrophotometry shows that the bandgap of both as-deposited and heat-treated CdTe films are in the range of (1.44–1.46) eV. The SEM shows grain growth after CdCl2 treatment, while, the EDX shows the effect of growth voltage on the atomic composition of CdTe layers. The PEC results show that both p- and n-type CdTe can be electrodeposited and the DC conductivity reveals that the high resistivity is at the inversion growth voltage (Vi) for the as-deposited and CdCl2 treated layers

Progress in development of graded bandgap thin film solar cells with electroplated materials

Photovoltaic devices are developed mainly based on p-n or p-i-n type device structures, and these devices can utilise only a fraction of the solar spectrum. In order to further improve device parameters and move towards low-cost and high-efficiency next generation solar cells, device architectures capable of harvesting all photons available should be designed and developed. One such architecture is the fully graded bandgap device structure as proposed recently based on both n-type and p-type window layers. These designs have been experimentally tested using well researched GaAs/AlGaAs system producing impressive device parameters of open circuit voltage (Voc) ~1175 mV and fill factor (FF) ~0.85. The devices have also been experimentally tested for the evidence of impurity photovoltaic (PV) effect and impact ionisation taking place within the same device. Since these structures have been experimentally proved with a well-established semiconductor, the effort has been focussed on developing these devices using low-cost and scalable electroplated semiconductors, in order to minimise manufacturing cost. This paper reviews and summarises the work carried out during the past decade on this subject. Graded bandgap devices produced using only two or three electroplated semiconductor layers have been explored and their conversion efficiencies have gradually increased from 10.0%, through 12.8% to 15.3% for different structures. While the work is progressing along this line, the paper summarises the achievements to date

Associations of vitamin D pathway genes with circulating 25-hydroxyvitamin-D, 1,25-dihydroxyvitamin-D, and prostate cancer:a nested case-control study

Vitamin D pathway single nucleotide polymorphisms (SNPs) are potentially useful proxies for investigating whether circulating vitamin D metabolites [total 25-hydroxyvitamin-D, 25(OH)D; 1,25-dihydroxyvitamin, 1,25(OH)2D] are causally related to prostate cancer. We investigated associations of sixteen SNPs across seven genes with prostate-specific antigen-detected prostate cancer

Genome-Wide Studies of Histone Demethylation Catalysed by the Fission Yeast Homologues of Mammalian LSD1

In order to gain a more global view of the activity of histone demethylases, we report here genome-wide studies of the fission yeast SWIRM and polyamine oxidase (PAO) domain homologues of mammalian LSD1. Consistent with previous work we find that the two S. pombe proteins, which we name Swm1 and Swm2 (after SWIRM1 and SWIRM2), associate together in a complex. However, we find that this complex specifically demethylates lysine 9 in histone H3 (H3K9) and both up- and down-regulates expression of different groups of genes. Using chromatin-immunoprecipitation, to isolate fragments of chromatin containing either H3K4me2 or H3K9me2, and DNA microarray analysis (ChIP-chip), we have studied genome-wide changes in patterns of histone methylation, and their correlation with gene expression, upon deletion of the swm1+ gene. Using hyper-geometric probability comparisons we uncover genetic links between lysine-specific demethylases, the histone deacetylase Clr6, and the chromatin remodeller Hrp1. The data presented here demonstrate that in fission yeast the SWIRM/PAO domain proteins Swm1 and Swm2 are associated in complexes that can remove methyl groups from lysine 9 methylated histone H3. In vitro, we show that bacterially expressed Swm1 also possesses lysine 9 demethylase activity. In vivo, loss of Swm1 increases the global levels of both H3K9me2 and H3K4me2. A significant accumulation of H3K4me2 is observed at genes that are up-regulated in a swm1 deletion strain. In addition, H3K9me2 accumulates at some genes known to be direct Swm1/2 targets that are down-regulated in the swm1¿ strain. The in vivo data indicate that Swm1 acts in concert with the HDAC Clr6 and the chromatin remodeller Hrp1 to repress gene expression. In addition, our in vitro analyses suggest that the H3K9 demethylase activity requires an unidentified post-translational modification to allow it to act. Thus, our results highlight complex interactions between histone demethylase, deacetylase and chromatin remodelling activities in the regulation of gene expression

Skin Cornification Proteins Provide Global Link between ROS Detoxification and Cell Migration during Wound Healing

Wound healing is a complex dynamic process characterised by a uniform flow of events in nearly all types of tissue damage, from a small skin scratch to myocardial infarction. Reactive oxygen species (ROS) are essential during the healing process at multiple stages, ranging from the initial signal that instigates the immune response, to the triggering of intracellular redox-dependent signalling pathways and the defence against invading bacteria. Excessive ROS in the wound milieu nevertheless impedes new tissue formation. Here we identify small proline-rich (SPRR) proteins as essential players in this latter process, as they directly link ROS detoxification with cell migration. A literature-based meta-analysis revealed their up-regulation in various forms of tissue injury, ranging from heart infarction and commensal-induced gut responses to nerve regeneration and burn injury. Apparently, SPRR proteins have a far more widespread role in wound healing and tissue remodelling than their established function in skin cornification. It is inferred that SPRR proteins provide injured tissue with an efficient, finely tuneable antioxidant barrier specifically adapted to the tissue involved and the damage inflicted. Their recognition as novel cell protective proteins combining ROS detoxification with cell migration will provide new venues to study and manage tissue repair and wound healing at a molecular level

Thioredoxin Glutathione Reductase as a Novel Drug Target: Evidence from Schistosoma japonicum

Background: Schistosomiasis remains a major public health concern affecting billions of people around the world. Currently, praziquantel is the only drug of choice for treatment of human schistosomiasis. The emergence of drug resistance to praziquantel in schistosomes makes the development of novel drugs an urgent task. Thioredoxin glutathione reductase (TGR) enzymes in Schistosoma mansoni and some other platyhelminths have been identified as alternative targets. The present study was designed to confirm the existense and the potential value of TGR as a target for development of novel antischistosomal agents in Schistosoma japonicum, a platyhelminth endemic in Asia. Methods and Findings: After cloning the S. japonicum TGR (SjTGR) gene, the recombinant SjTGR selenoprotein was purified and characterized in enzymatic assays as a multifunctional enzyme with thioredoxin reductase (TrxR), glutathione reductase (GR) and glutaredoxin (Grx) activities. Immunological and bioinformatic analyses confirmed that instead of having separate TrxR and GR proteins in mammalian, S. japonicum only encodes TGR, which performs the functions of both enzymes and plays a critical role in maintaining the redox balance in this parasite. These results were in good agreement with previous findings in Schistosoma mansoni and some other platyhelminths. Auranofin, a known inhibitor against TGR, caused fatal toxicity in S. japonicum adult worms in vitro and reduced worm and egg burdens in S. japonicum infected mice. Conclusions: Collectively, our study confirms that a multifunctional enzyme SjTGR selenoprotein, instead of separate Trx

Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector

Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente

Performance of the CMS Cathode Strip Chambers with Cosmic Rays

The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device in the CMS endcaps. Their performance has been evaluated using data taken during a cosmic ray run in fall 2008. Measured noise levels are low, with the number of noisy channels well below 1%. Coordinate resolution was measured for all types of chambers, and fall in the range 47 microns to 243 microns. The efficiencies for local charged track triggers, for hit and for segments reconstruction were measured, and are above 99%. The timing resolution per layer is approximately 5 ns

School-based intervention to improve the mental health of low-income, secondary school students in Santiago, Chile (YPSA): study protocol for a randomized controlled trial

<p>Abstract</p> <p>Background</p> <p>Depression is common and can have devastating effects on the life of adolescents. Psychological interventions are the first-line for treating or preventing depression among adolescents. This proposal aims to evaluate a school-based, universal psychological intervention to reduce depressive symptoms among student's aged 13-14 attending municipal state secondary schools in Santiago, Chile.</p> <p>Study design</p> <p>This is a cluster randomised controlled trial with schools as the main clusters. We compared this intervention with a control group in a study involving 22 schools, 66 classes and approximately 2,600 students. Students in the active schools attended 11 weekly and 3 booster sessions of an intervention based on cognitive-behavioural models. The control schools received their usual but enhanced counselling sessions currently included in their curriculum. Mean depression scores and indicators of levels of functioning were assessed at 3 and 12 months after the completion of the intervention in order to assess the effectiveness of the intervention. Direct and indirect costs were measured in both groups to assess the cost-effectiveness of this intervention.</p> <p>Discussion</p> <p>As far as we are aware this is the first cluster randomised controlled trial of a school intervention for depression among adolescents outside the Western world.</p> <p>Trial Registration</p> <p><a href="http://www.controlled-trials.com/ISRCTN19466209">ISRCTN19466209</a></p