99 research outputs found
Comparison of the Effects of Saline and Alkaline Stress on Growth, Photosynthesis and Water-Soluble Carbohydrate of Oat Seedling (Avena sativa L)
Comparisons of WUE in twelve genotypes of winter wheat and the relationship between δ13C and WUE
Twelve winter wheat (Triticum aestivum) genotypes were examined for differences in grain yield, water use efficiency (WUE), and stable carbon isotope composition (δ13C) in flag leaves. The plants were subjected to rain-fed treatment and supplemental irrigation at the jointing and anthesis stages, during the 2015â2016 and 2016â2017 winter wheat growing seasons. The relationships between δ13C with grain yield and WUE were analyzed under two different water environments. The results indicated that there were significant differences in δ13C, grain yield, and WUE among wheat genotypes both under rain-fed and supplemental irrigation conditions. The δ13C values increased with grain-filling proceeding, the δ13C being lower under supplemental irrigation treatment than that under rain-fed treatment. The relationships between the average of δ13C with grain yield and WUE were significantly positive during three measurement periods (R2 = 0.5785 â 0.8258), whether under rain-fed or irrigation environments. This suggests that δ13C might be associated with the grain yield and WUE in winter wheat under rain-fed and supplemental irrigation conditions in the climate region of the northwest Huang-Huai-Hai Plain of China
Phase Modulation of (1T-2H)-MoSe2/TiC-C Shell/Core Arrays via Nitrogen Doping for Highly Efficient Hydrogen Evolution Reaction
Tailoring molybdenum selenide electrocatalysts with tunable phase and morphology is of great importance for advancement of hydrogen evolution reaction (HER). In this work, phaseâ and morphologyâmodulated Nâdoped MoSe2/TiCâC shell/core arrays through a facile hydrothermal and postannealing treatment strategy are reported. Highly conductive TiCâC nanorod arrays serve as the backbone for MoSe2 nanosheets to form highâquality MoSe2/TiCâC shell/core arrays. Impressively, continuous phase modulation of MoSe2 is realized on the MoSe2/TiCâC arrays. Except for the pure 1TâMoSe2 and 2HâMoSe2, mixed (1Tâ2H)âMoSe2 nanosheets are achieved in the NâMoSe2 by N doping and demonstrated by spherical aberration electron microscope. Plausible mechanism of phase transformation and different doping sites of N atom are proposed via theoretical calculation. The much smaller energy barrier, longer HSe bond length, and diminished bandgap endow NâMoSe2/TiCâC arrays with substantially superior HER performance compared to 1T and 2H phase counterparts. Impressively, the designed NâMoSe2/TiCâC arrays exhibit a low overpotential of 137 mV at a large current density of 100 mA cmâ2, and a small Tafel slope of 32 mV decâ1. Our results pave the way to unravel the enhancement mechanism of HER on 2D transition metal dichalcogenides by N doping
Case report: Gene mutation analysis and skin imaging of isolated cafĂŠ-au-lait macules
Background: CafĂŠ-au-lait macules (CALMs) are common birthmarks associated with several genetic syndromes, such as neurofibromatosis type 1 (NF1). Isolated CALMs are defined as multiple cafĂŠ-au-lait macules in patients without any other sign of NF1. Typical CALMs can have predictive significance for NF1, and non-invasive techniques can provide more accurate results for judging whether cafĂŠ-au-lait spots are typical.Objectives: The study aimed to investigate gene mutations in six Chinese Han pedigrees of isolated CALMs and summarize the characteristics of CALMs under dermoscopy and reflectance confocal microscopy (RCM).Methods: In this study, we used Sanger sequencing to test for genetic mutations in six families and whole exome sequencing (WES) in two families. We used dermoscopy and RCM to describe the imaging characteristics of CALMs.Results: In this study, we tested six families for genetic mutations, and two mutations were identified as novel mutations. The first family identified [NC_000017.11(NM_001042492.2):c.7355G>A]. The second family identified [NC_000017.11(NM_001042492.2):c.2739_2740del]. According to genotype-phenotype correlation analyses, proband with frameshift mutation tended to have a larger number of CALMs and a higher rate of having atypical CALMs. Dermoscopy showed uniform and consistent tan-pigmented network patches with poorly defined margins with a lighter color around the hair follicles. Under RCM, the appearance of NF1 comprised the increased pigment granules in the basal layer and significantly increased refraction.Conclusion: A new heterozygous mutation and a new frameshift mutation of NF1 were reported. This article can assist in summarizing the properties of dermoscopy and RCM with CALMs
Robust adaptive immune response against Babesia microti infection marked by low parasitemia in a murine model of sickle cell disease.
The intraerythrocytic parasite Babesia microti is the number 1 cause of transfusion-transmitted infection and can induce serious, often life-threatening complications in immunocompromised individuals including transfusion-dependent patients with sickle cell disease (SCD). Despite the existence of strong long-lasting immunological protection against a second infection in mouse models, little is known about the cell types or the kinetics of protective adaptive immunity mounted following Babesia infection, especially in infection-prone SCD that are thought to have an impaired immune system. Here, we show, using a mouse B microti infection model, that infected wild-type (WT) mice mount a very strong adaptive immune response, characterized by (1) coordinated induction of a robust germinal center (GC) reaction; (2) development of follicular helper T (TFH) cells that comprise âź30% of splenic CD4+ T cells at peak expansion by 10 days postinfection; and (3) high levels of effector T-cell cytokines, including interleukin 21 and interferon Îł, with an increase in the secretion of antigen (Ag)-specific antibodies (Abs). Strikingly, the Townes SCD mouse model had significantly lower levels of parasitemia. Despite a highly disorganized splenic architecture before infection, these mice elicited a surprisingly robust adaptive immune response (including comparable levels of GC B cells, TFH cells, and effector cytokines as control and sickle trait mice), but higher immunoglobulin G responses against 2 Babesia-specific proteins, which may contain potential immunogenic epitopes. Together, these studies establish the robust emergence of adaptive immunity to Babesia even in immunologically compromised SCD mice. Identification of potentially immunogenic epitopes has implications to identify long-term carriers, and aid Ag-specific vaccine development. Š 2018 by The American Society of Hematology
Cyclization reaction of amines with dialkyl carbonates to yield 1,3-oxazinan-2-ones
A number of six-membered cyclic carbamates (oxazinanones) were synthesized from the reaction of a primary amine or hydrazine with a dicarbonate derivative of 1,3-diols in a one-pot reaction, in good yield, short time span, and in the absence of a solvent. The reaction proceeds in two steps: an intermolecular reaction to give a linear intermediate and an intramolecular cyclization to yield the cyclic carbamate. This is the first example of a carbonate reacting selectively and sequentially, firstly at the carbonyl center to form a linear carbamate and then as a leaving group to yield a cyclic carbamate
Tuberous Sclerosis Complex With Multiple Organ Tumors: Case Report and Literature Review
Pancreatic neuroendocrine neoplasms (PNEN) are tumors that originate from neuroendocrine cells. Only about 1% patients are related to mutation of tuberous sclerosis complex gene. Here, we reported a rare case with involvement of multiple organs and space-occupying lesions. Initially, the patient was thought to have metastasis of a pancreatic tumor. However, the patient was diagnosed as pancreatic neuroendocrine tumors, liver perivascular epithelioid tumors, splenic hamartoma, and renal angiomyolipoma by pathological examination after surgery. We performed genetic mutation detection to identify that tuberous sclerosis complex 2 gene presented with a heterozygous variant. Tuberous sclerosis often presents with widespread tumors, but it is less common to present with pancreatic neuroendocrine tumors and liver perivascular tumors as highlighted in the case. So we analyzed the relationship between TSC gene mutations and related tumors. And we also reviewed the current molecular mechanisms and treatments for tuberous sclerosis complex
Nonlinear SolidâFluid Coupled Seismic Response Analysis of Layered Liquefiable Deposit
A seismic response analysis of layered, liquefiable sites plays an important role in the seismic design of both aboveground and underground structures. This study presents a detailed dynamic site response analysis procedure with advanced nonlinear soil constitutive models for non-liquefiable and liquefiable soils in the OpenSees computational platform. The stress ratio controlled, bounding surface plasticity constitutive model, PM4Sand, is used to simulate the nonlinear response of the liquefiable soil layers subjected to two seismic ground motions with different characteristics. The nonlinear hysteretic behavior of the non-liquefiable soil under earthquake excitations is captured by the Pressure Independent Multi Yield kinematic plasticity model with a von Mises multi-yield surface. The soil elements are modelled utilizing the solidâfluid fully coupled plane-strain u-p elements. The seismic response of the layered liquefiable site in terms of the development of excess pore water pressure, acceleration, ground surface settlement, and stressâstrain and effective stress path time histories under two representative earthquake excitations are investigated in this study. The numerical results indicate that both the characteristics of ground motions and the site profile have a significant influence on the dynamic response of the layered liquefiable site. Under the same intensity of ground motion, the loose sand layer with a 35% relative density is more prone to liquefaction and contractive deformation, which causes irreversible residual deformation and vertical settlement. The saturated soil layer can effectively filter the high-frequency components and amplify the low-frequency components of ground motions. Moreover, the liquified site produces a 40% post-earthquake consolidation settlement after the excess pore pressure dissipation
Nonlinear Solid–Fluid Coupled Seismic Response Analysis of Layered Liquefiable Deposit
A seismic response analysis of layered, liquefiable sites plays an important role in the seismic design of both aboveground and underground structures. This study presents a detailed dynamic site response analysis procedure with advanced nonlinear soil constitutive models for non-liquefiable and liquefiable soils in the OpenSees computational platform. The stress ratio controlled, bounding surface plasticity constitutive model, PM4Sand, is used to simulate the nonlinear response of the liquefiable soil layers subjected to two seismic ground motions with different characteristics. The nonlinear hysteretic behavior of the non-liquefiable soil under earthquake excitations is captured by the Pressure Independent Multi Yield kinematic plasticity model with a von Mises multi-yield surface. The soil elements are modelled utilizing the solid–fluid fully coupled plane-strain u-p elements. The seismic response of the layered liquefiable site in terms of the development of excess pore water pressure, acceleration, ground surface settlement, and stress–strain and effective stress path time histories under two representative earthquake excitations are investigated in this study. The numerical results indicate that both the characteristics of ground motions and the site profile have a significant influence on the dynamic response of the layered liquefiable site. Under the same intensity of ground motion, the loose sand layer with a 35% relative density is more prone to liquefaction and contractive deformation, which causes irreversible residual deformation and vertical settlement. The saturated soil layer can effectively filter the high-frequency components and amplify the low-frequency components of ground motions. Moreover, the liquified site produces a 40% post-earthquake consolidation settlement after the excess pore pressure dissipation
Numerical Simulation of Frictional Heating Effects of Sliding Friction Bearings for Isolated Bridges
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