Genome-wide identification and expression of GRAS gene family members in cassava.

BACKGROUND: Cassava is highly tolerant to stressful conditions, especially drought stress conditions; however, the mechanisms underlying this tolerance are poorly understood. The GRAS gene family is a large family of transcription factors that are involved in regulating the growth, development, and stress responses of plants. Currently, GRAS transcription factors have not been systematically studied in cassava, which is the sixth most important crop in the world. RESULTS: Seventy-seven MeGRAS genes were identified from the cassava genome database. Phylogenetic analysis revealed that the MeGRAS proteins could be divided into 14 subfamilies. The gene structure and motif compositions of the proteins were considerably conserved within the same subfamily. Duplication events, particularly segmental duplication, were identified as the main driving force for GRAS gene expansion in cassava. Global expression analysis revealed that MeGRAS genes exhibited similar or distinct expression profiles within different tissues among different varieties. Moreover, qRT-PCR analysis revealed the expression patterns of MeGRAS genes in response to abiotic stress (drought, salt, cold, and H2O2), and the results suggest that these genes may have multiple functions. CONCLUSION: This study is the first to provide comprehensive information on GRAS gene family members in cassava. The data will increase our understanding of both the molecular basis and the effects of GRAS genes. In addition, the results will contribute further to identifying the responses to various environmental conditions and provide insights into the potential functions of GRAS genes.

2D SiP2/h-BN for a Gate-Controlled Phototransistor with Ultrahigh Sensitivity.

Two-dimensional (2D) materials are extremely attractive for the construction of highly sensitive photodetectors due to their unique electronic and optical properties. However, developing 2D photodetectors with ultrahigh sensitivity for extremely low-light-level detection is still a challenge owing to the limitation of high dark current and low detectivity. Herein, a gate-controlled phototransistor based on 2D SiP2/hexagonal boron nitride (h-BN) was rationally designed and demonstrated ultrahigh sensitivity for the first time. With a back-gate device geometry, the SiP2/h-BN phototransistor exhibits an ultrahigh detectivity of 3.4 × 1013 Jones, which is one of the highest values among 2D material-based photodetectors. In addition, the phototransistor also shows a gate tunable responsivity of ≤43.5 A/W at a gate voltage of 30 V due to the photogating effect. The ultrahigh sensitivity of the SiP2-based phototransistor is attributed to the extremely low dark current suppressed by the phototransistor configuration and the improved photocurrent by using h-BN as a substrate to reduce charge scattering. This work provides a facile strategy for improving the detectivity of photodetectors and validates the great potential of 2D SiP2 phototransistors for ultrasensitive optoelectronic applications.

Strong In-Plane Anisotropic SiP2 as a IV-V 2D Semiconductor for Polarized Photodetection.

In-plane anisotropic two-dimensional (2D) materials, emerging as an intriguing type of 2D family, provide an ideal platform for designing and fabrication of optoelectronic devices. Exploring air-stable and strong in-plane anisotropic 2D materials is still challenging and promising for polarized photodetection. Herein, SiP2, a 2D IV-V semiconductor, is successfully prepared and introduced into an in-plane anisotropic 2D family. The basic characterizations combined with theoretical calculations reveal 2D SiP2 to exhibit an intrinsically low-symmetry structure, the in-plane anisotropy of phonon vibrations, and an anisotropically dispersed band structure. Moreover, the photodetector based on 2D SiP2 exhibits high performance with a high detectivity of 1012 Jones, a large light on/off ratio of 103, a low dark current of 10-13 A, and a fast response speed of 3 ms. Furthermore, 2D SiP2 demonstrates a high anisotropic photodetection with an anisotropic ratio up to 2. In addition, the polarization-sensitive photodetector presents a dichroic ratio of 1.6 due to the intrinsic linear dichroism. These good characteristics make 2D SiP2 a promising candidate as an in-plane anisotropic semiconductor for high-sensitivity and polarized optoelectronic applications.

Cinnamon extracts exert intrapancreatic cytoprotection against streptozotocin in vivo.

In the current study, we aimed to investigate the potential hypoglycemic bioactivity of cinnamon extracts (CES) on streptozotocin (STZ)-induced hyperglycemia in mice. In biological methods, glucose metabolic ability of all mice was evaluated by glucose tolerance testing (GTT). Blood levels of pancreas-produced insulin, glucagon, inflammation-associated interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α) were determined via enzyme-linked immunosorbent assay (ELISA). In gene level, intrapancreatic mRNA expressions of insulin, TNF-α and nuclear-factor kappa B (NF-κB) were assayed by reverse transcription polymerase chain reaction (RT-PCR). Meanwhile, intracellular insulin-immunoactive cells in the pancreas were analyzed by using immunohistochemical staining. In addition, the protein levels of intrapancreatic NF-κB, IκB (p-IκB) and IKK were tested by western blotting. As a result, CES-treated mice showed increased body weight, blood glucose and insulin, reduced IL-6 and TNF-α contents in sera. Further, the TNF-α and NF-κB mRNA expressions in the CES-treated pancreas were down-regulated at a dose-dependent manner, while insulin mRNA was elevated. Moreover, the reduced intrapancreatic NF-κB, IκB (p-IκB) and IKK expression were observed in CES-treated pancreas, respectively. Taken together, our current findings indicate that CES-mediated intrapancreatic cytoprotection is linked to the molecular mechanism that may be through inhibiting inflammatory stress and promoting insulin secretion in the pancreas.

Diagnostic accuracy of treadmill exercise tests among Chinese women with coronary artery diseases: A systematic review and meta-analysis.

BACKGROUND: The treadmill exercise test (TET) is one of the most common noninvasive diagnosis approaches for ischemic heart diseases, but potential reduction of TET accuracy among Chinese female patients was ignored by most studies, especially in perimenopause women. Hence, we aim to perform a systematic review and meta-analysis evaluating the TET diagnostic accuracy for Chinese women compared with coronary angiography (CAG). METHODS: PubMed, MEDLINE, EMBASE, CNKI and WANFANG (1990 to 2015) were performed to identify studies assessing the diagnostic accuracy of TET versus CAG. Random effects modeling strategies were used to produce summary receiver operating characteristic (SROC) curves, including overall estimates for sensitivity and specificity. RESULTS: A total of 19 studies involving 2396 Chinese females were included in our systematic review. TET has moderate levels of sensitivity (0.80) and specificity (0.65) to detect coronary artery stenoses in female patients with suspected coronary artery diseases, generating 0.79 of the area under the curve (AUC). In subgroup analyses, the pooled sensitivity of postmenopause and premenopausal/perimenopausal groups were 0.83 and 0.80, respectively. However, the postmenopause group has a higher pooled specificity: 0.68 versus 0.32 compared with premenopausal/perimenopausal women, and a higher corresponding AUC (0.81 versus 0.56). CONCLUSIONS: TET may be used as a triage test for women with suspected and subclinical CAD. The positive results of TET should be treated with caution because of its higher false-positive, especially for premenopausal/perimenopausal women, and further confirmatory diagnosis is needed. However, patients with negative TET results could be precluded for further evaluation using CAG, and avoid unnecessary risk and economic burden to patients.

[The immunological characteristics of tonsil mesenchymal stem cells].

OBJECTIVE: To investigate the immunological characteristics of human tonsil mesenchymal stem cells (TMSCs). METHODS: Human tonsil tissues were obtained from the children patients with chronic tonsillitis. TMSCs were separated, cultured, and were detected the expression profiles of HLA-I, HLA-II, CD80, CD86 by flow cytometry. The measurement of immunogenicity, the effect on phytohemagglutinin (PHA) induced peripheral blood mononuclear cell (PBMCs) proliferation and mixed lymphocytes reaction (MLR) were performed to identify the immunological characteristics of TMSCs. The co-cultures of TMSCs + PBMCs + PHA and TMSCs + MLR were established, respectively, and the concentration of kynurenine, which is the metabolin of indoleamine 2, 3-dioxygenase, in the culture supernatant were examined. Then we added 1-methyl-L-tryptophan into the co-culture of TMSCs + PBMCs + PHA and TMSCs + MLR, respectively, and tested the proliferation of PBMCs. Each experiment was repeated three times, and there were six samples in each group. Statistical significance was assessed by analysis of variance (ANOVA), and a P value less than 0.05 was considered statistically significant. RESULTS: TMSCs expressed HLA-I, were negative for HLA-II and co-stimulatory molecules CD80 and CD86. The stimulation index in the group of TMSCs + allogeneic PBMCs was 1.38 ± 0.26, whereas the stimulation index in the group of allogeneic PBMCs was 1.22 ± 0.28, and there was no significant difference between the two groups (P > 0.05), indicating that TMSCs could not initiate the proliferation of allogeneic PBMCs. The stimulation indexes in the group of TMSCs + allogeneic PBMCs + PHA were 1.49 ± 0.29 and 1.23 ± 0.22, respectively, whereas the stimulation index in the group of allogeneic PBMCs + PHA was 4.60 ± 0.81, and the difference between the two groups had a statistical significance (P < 0.05) suggesting that TMSCs could inhibit PHA-induced PBMCs proliferation. The stimulation indexes in the group of TMSCs + MLR were 1.29 ± 0.23 and 1.26 ± 0.27, respectively, however, the stimulation index in the group of MLR was 3.04 ± 0.66, and the difference between the two groups had a statistical significance (P < 0.05), demonstrating that TMSCs could suppress MLR-induced PBMCs proliferation. The levels of kynurenine were (26.0 ± 2.3) µmol/L and (23.5 ± 4.5) µmol/L in the culture of TMSCs + PBMCs + PHA and TMSCs + MLR, respectively, thus elevating significantly. After adding of 1-methyl-L-tryptophan, TMSCs-mediated-proliferation suppression of PBMCs restored to normal levels. CONCLUSION: TMSCs possess low immunogenecity and immunosuppressive function, may be used in allogeneic transplantation.

Osteogenic differentiated periodontal ligament stem cells maintain their immunomodulatory capacity.

Periodontal ligament stem cells (PDLSCs) have great potential for regenerating periodontal ligament tissue, which is involved in attaching teeth to the underlying alveolar bone. Recently, PDLSCs were characterized as having both low immunogenicity and profound immunomodulation abilities. Further, transplanted PDLSCs differentiate into osteoblasts in vivo. In the present study, we investigated the immunological characteristics of osteogenic differentiated PDLSCs. We found that PDLSCs expressed mesenchymal stem cells markers, including STRO-1 and CD146, but were negative for CD14, CD34 and CD45. RT-PCR indicated that NCAM1, MSX1 and S100A4 were expressed in PDLSCs. The cells underwent osteogenic and adipogenic differentiation when cultured in defined medium. Osteogenic differentiated PDLSCs failed to stimulate allogeneic T cell proliferation and suppressed phytohaemagglutinin-triggered T cell proliferation. Indomethacin, an inhibitor of prostaglandin E2 (PGE2) production, restored the T cell proliferation inhibited by osteogenic differentiated PDLSCs. These data confirm that osteogenic differentiated PDLSCs have low immunogenicity and demonstrate that they suppress T cell proliferation in vitro through secretion of PGE2.

Tupichinins B-D, three new spirostanol saponins from Tupistra chinensis rhizomes.

Three new spirostanol saponins were isolated from the EtOAc fraction of methanol extract from Tupistra chinensis rhizomes. Based on the detailed analysis of their 1D and 2D NMR spectra and chemical evidence, their structures were determined as 1ß-O-acetyl-spirost-5,25(27)-dien-3α-yl-O-ß-D-glucopyranoside (1), (25S)-1ß,2ß,5ß-trihydroxy-spirostane-3ß-yl-O-ß-D-glucopyranoside (2) and (25S)-1ß,2ß-dihydroxy-5ß-spirostane-3ß-yl-O-ß-D-xylopyranoside (3), respectively.

Chemical constituents of Tupistra chinensis rhizomes.

A new pregnane glycoside, a dibenzylbutyrolactone lignan, 5-hydroxymatairesinol dimethyl ether, and three new flavonoids, including one 8-methylflavan-3-ol, and two 8-methylflavones, together with five known flavonoids and two known alkaloids were isolated from the rhizomes of Tupistra chinensis. The structures of all compounds were elucidated by spectral studies.

New flavans, spirostanol sapogenins, and a pregnane genin from Tupistra chinensis and their cytotoxicity.

Seven new compounds, including three new flavans [tupichinol A-C (1-3)], three new spirostanol sapogenins [tupichigenin D-F (4-6)], and one new pregnane genin [tupipregnenolone (7)], together with 18 known compounds, were isolated from the underground parts of Tupistra chinensis. The structures of the new compounds were elucidated by spectroscopic analysis and chemical evidence. The structures and relative stereochemistry of 1 and 9 were further confirmed by single-crystal X-ray crystallographic analysis. Compounds Delta(25(27))-pentrogenin, 10, and ranmogenin A showed 100%, 96%, and 80% inhibition, respectively, against human gastric tumor (NUGC) cells at a concentration of 50 microM. Delta(25(27))-pentrogenin showed 100% inhibition against human nasopharyngeal carcinoma (HONE-1) cells at a concentration of 50 microM.