The effect of Ga-doped nanocrystalline ZnO electrode on deep-ultraviolet enhanced GaN photodetector

published_or_final_versio

Probing deep level centers in GaN epilayers with variable-frequency capacitance-voltage characteristics of AuGaN Schottky contacts

Under identical preparation conditions, AuGaN Schottky contacts were prepared on two kinds of GaN epilayers with significantly different background electron concentrations and mobility as well as yellow emission intensities. Current-voltage (I-V) and variable-frequency capacitance-voltage (C-V) characteristics show that the Schottky contacts on the GaN epilayer with a higher background carrier concentration and strong yellow emission exhibit anomalous reverse-bias I-V and C-V characteristics. This is attributed to the presence of deep level centers. Theoretical simulation of the low-frequency C-V curves leads to a determination of the density and energy level position of the deep centers. © 2006 American Institute of Physics.published_or_final_versio

Effects of annealing temperature on the characteristics of Ga-doped ZnO film metal-semiconductor-metal ultraviolet photodetectors

published_or_final_versio

Evidence for genetic association of TBX21 and IFNG with systemic lupus erythematosus in a Chinese Han population

TBX21 recode T-bet which is an important transcription factor that drives the Th1 immune response primarily by promoting expression of the interferon-gamma (IFNG) gene. Recent studies have shown that genetic variants in TBX21 and IFNG are connected with risk of systemic lupus erythematosus (SLE). The aim of the present study was to replicate these genetic associations with SLE in Anhui Chinese population. Genotyping of 3 variants (rs4794067 in TBX21, rs2069705 and rs2069718 in IFNG) was performed. A total of 3732 subjects were included in the final analysis. The study only identified the association of rs2069705 with SLE susceptibility (T vs. C: odds ratio [OR] = 1.12, 95% confidence interval [CI] = 1.00-1.26, P = 0.046). Combined analysis with Hong Kong GWAS showed that the OR for rs2069705 was 1.10 (95% CI: 1.01-1.21, P = 0.027). Further pooled analysis with Korean populations involving 10498 subjects showed a more significant association between rs2069705 and SLE (T vs. C: OR = 1.11, 95%CI = 1.04-1.19, P = 0.002; TT + TC vs. CC: OR = 1.11, 95%CI = 1.02-1.21, P = 0.012; TT vs. TC + CC: OR = 1.28, 95%CI = 1.07-1.54, P = 0.008; TT vs. CC: OR = 1.33, 95%CI = 1.10-1.60, P = 0.003). In addition, we also identified a significant genetic interaction between rs2069705 and rs4794067 in Anhui Chinese population. Our study suggests that IFNG and IFNG-TBX21 interaction are involved in SLE susceptibility.published_or_final_versio

Additive-Free, Low-Temperature Crystallization of Stable α-FAPbI3 Perovskite

Formamidinium lead triiodide (FAPbI3) is attractive for photovoltaic devices due to its optimal bandgap at around 1.45 eV and improved thermal stability compared with methylammonium‐based perovskites. Crystallization of phase‐pure α‐FAPbI3 conventionally requires high‐temperature thermal annealing at 150 °C whilst the obtained α‐FAPbI3 is metastable at room temperature. Here, aerosol‐assisted crystallization (AAC) is reported, which converts yellow δ‐FAPbI3 into black α‐FAPbI3 at only 100 °C using precursor solutions containing only lead iodide and formamidinium iodide with no chemical additives. The obtained α‐FAPbI3 exhibits remarkably enhanced stability compared to the 150 °C annealed counterparts, in combination with improvements in film crystallinity and photoluminescence yield. Using X‐ray diffraction, X‐ray scattering, and density functional theory simulation, it is identified that relaxation of residual tensile strains, achieved through the lower annealing temperature and post‐crystallization crystal growth during AAC, is the key factor that facilitates the formation of phase‐stable α‐FAPbI3. This overcomes the strain‐induced lattice expansion that is known to cause the metastability of α‐FAPbI3. Accordingly, pure FAPbI3 p–i–n solar cells are reported, facilitated by the low‐temperature (≤100 °C) AAC processing, which demonstrates increases of both power conversion efficiency and operational stability compared to devices fabricated using 150 °C annealed films

Prediction of Ubiquitination Sites by Using the Composition of k-Spaced Amino Acid Pairs

As one of the most important reversible protein post-translation modifications, ubiquitination has been reported to be involved in lots of biological processes and closely implicated with various diseases. To fully decipher the molecular mechanisms of ubiquitination-related biological processes, an initial but crucial step is the recognition of ubiquitylated substrates and the corresponding ubiquitination sites. Here, a new bioinformatics tool named CKSAAP_UbSite was developed to predict ubiquitination sites from protein sequences. With the assistance of Support Vector Machine (SVM), the highlight of CKSAAP_UbSite is to employ the composition of k-spaced amino acid pairs surrounding a query site (i.e. any lysine in a query sequence) as input. When trained and tested in the dataset of yeast ubiquitination sites (Radivojac et al, Proteins, 2010, 78: 365–380), a 100-fold cross-validation on a 1∶1 ratio of positive and negative samples revealed that the accuracy and MCC of CKSAAP_UbSite reached 73.40% and 0.4694, respectively. The proposed CKSAAP_UbSite has also been intensively benchmarked to exhibit better performance than some existing predictors, suggesting that it can be served as a useful tool to the community. Currently, CKSAAP_UbSite is freely accessible at http://protein.cau.edu.cn/cksaap_ubsite/. Moreover, we also found that the sequence patterns around ubiquitination sites are not conserved across different species. To ensure a reasonable prediction performance, the application of the current CKSAAP_UbSite should be limited to the proteome of yeast

Intrathecal Injection of Spironolactone Attenuates Radicular Pain by Inhibition of Spinal Microglia Activation in a Rat Model

Microglia might play an important role in nociceptive processing and hyperalgesia by neuroinflammatory process. Mineralocorticoid receptor (MR) expressed on microglia might play a central role in the modulation of microglia activity. However the roles of microglia and MR in radicular pain were not well understood. This study sought to investigate whether selective MR antagonist spironolactone develop antinociceptive effects on radicular pain by inhibition neuroinflammation induced by spinal microglia activation.Radicular pain was produced by chronic compression of the dorsal root ganglia with SURGIFLO™. The expression of microglia, interleukin beta (IL-1β), interleukin 6 (IL-6), tumor necrosis factor alpha (TNF-α), NR1 subunit of the NMDA receptor (t-NR1), and NR1 subunit phosphorylated at Ser896 (p-NR1) were also markedly up-regulated. Intrathecal injection of spironolactone significantly attenuated pain behaviors as well as the expression of microglia, IL-1β, TNF-α, t-NR1, and p-NR1, whereas the production of IL-6 wasn't affected.These results suggest that intrathecal delivery spironolactone has therapeutic effects on radicular pain in rats. Decreasing the activation of glial cells, the production of proinflammatory cytokines and down-regulating the expression and phosphorylation of NMDA receptors in the spinal dorsal horn and dorsal root ganglia are the main mechanisms contributing to its beneficial effects

Suppression of Estrogen Receptor Transcriptional Activity by Connective Tissue Growth Factor

Secreted growth factors have been shown to stimulate the transcriptional activity of estrogen receptors (ER) that are responsible for many biological processes. However, whether these growth factors physically interact with ER remains unclear. Here, we show for the first time that connective tissue growth factor (CTGF) physically and functionally associates with ER. CTGF interacted with ER both in vitro and in vivo. CTGF interacted with ER DNA-binding domain. ER interaction region in CTGF was mapped to the thrombospondin type I repeat, a cell attachment motif. Overexpression of CTGF inhibited ER transcriptional activity as well as the expression of estrogen-responsive genes, including pS2 and cathepsin D. Reduction of endogenous CTGF with CTGF small interfering RNA enhanced ER transcriptional activity. The interaction between CTGF and ER is required for the repression of estrogen-responsive transcription by CTGF. Moreover, CTGF reduced ER protein expression, whereas the CTGF mutant that did not repress ER transcriptional activity also did not alter ER protein levels. The results suggested the transcriptional regulation of estrogen signaling through interaction between CTGF and ER, and thus may provide a novel mechanism by which cross-talk between secreted growth factor and ER signaling pathways occurs