High‐temperature dielectric polymers are in constant demand for the multitude of high‐power electronic devices employed in hybrid vehicles, grid‐connected photovoltaic and wind power generation, to ...name a few. There is still a lack, however, of dielectric polymers that can work at high temperature (> 150 °C). Herein, a series of all‐organic dielectric polymer composites have been fabricated by blending the n‐type molecular semiconductor 1,4,5,8‐naphthalenetetracarboxylic dianhydride (NTCDA) with polyetherimide (PEI). Electron traps are created by the introduction of trace amounts of n‐type small molecule semiconductor NTCDA into PEI, which effectively reduces the leakage current and improves the breakdown strength and energy storage properties of the composite at high temperature. Especially, excellent energy storage performance is achieved in 0.5 vol.% NTCDA/PEI at the high temperatures of 150 and 200 °C, e.g., ultrahigh discharge energy density of 5.1 J cm−3 at 150 °C and 3.2 J cm−3 at 200 °C with high discharge efficiency of 85–90%, which is superior to its state‐of‐the‐art counterparts. This study provides a facile and effective strategy for the design of high‐temperature dielectric polymers for advanced electronic and electrical systems.
This study reports the novel all‐organic dielectric composite films of 1,4,5,8‐naphthalenetetracarboxylic dianhydride (NTCDA)/polyetherimide (PEI) by using a facile solution casting method. By judiciously introducing semiconducting NTCDA into PEI, electron traps are successfully constructed, effectively reducing the leakage current and improving the breakdown strength. Finally, excellent high‐temperature energy storage performance is achieved in 0.5 vol.% NTCDA/PEI at 150 and 200 °C.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Background：Improving islet graft revascularization has become a crucial task for prolonging islet graft survival.Endothelial cells （ECs） are the basis of new microvessels in an isolated islet,and EC ...coating has been demonstrated to improve the vascularization and survival of an islet.However,the traditional method of EC coating of islets has low efficiency in vitro.This study was conducted to evaluate the effect of a polyglycolic acid （PGA） scaffold on the efficiency of islet coating by ECs and the angiogenesis in the coated islet graft.Methods：A PGA fibrous scaffold was used for EC coating of islet culture and was evaluated for its efficiency of EC coating on islets and islet graft angiogenesis.Results：In in vitro experiments,we found that apoptosis index of ECs-coating islet in PGA group （27% ± 8%） was significantly lower than that in control group （83% ± 20%,P 〈 0.05） after 7 days culture.Stimulation index was significantly greater in the PGA group than in the control group at day 7 after ECs-coating （2.07 ± 0.31 vs.1.80 ± 0.23,P 〈 0.05）.vascular endothelial growth factor （VEGF） level in the PGA group was significantly higher than the coating in the control group after 7 days culture （52.10 ± 13.50 ng/ml vs.16.30 ± 8.10 ng/ml,P 〈 0.05）.Because of a tight,circumvallated,adhesive and three-dimensional growth microenvironment,islet cultured in a PGA scaffold had higher coating efficiency showing stronger staining intensity of enzyme than those in the control group after 14 days of culture following ECs-coating.For in vivo study,PGA scaffold significantly prolonged the average survival time of EC-coated islet graft after transplantation compared with control group （15.30 ± 5.60 days vs.8.30 ± 2.45 days,P 〈 0.05）.The angiogenesis and area of survived grafts were more in the PGA group compared with the control group by measuring the mean microvessel density （8.60 ± 1.21/mm2 vs.5.20 ± 0.87/mm2,P 〈 0.05）.In addition,expression of VEGF and tyrosin-protein kinase receptor （Tie-2） gene increased in PGA scaffold group than that in control group by real-time reverse transcription-polymerase chain reaction analysis.Conclusions：These results demonstrate that the efficiency of EC coating of islets was successfully increased by culturing ECs on a PGA scaffold.This method enhances the function,survival,and vascularization of isolated islets in vitro and in vivo.
Macrophages play a crucial role in the progression of hepatic fibrosis (HF). In macrophages, epigenetic mechanisms are increasingly being recognized as crucial controllers of their phenotype. ...However, the functions of macrophage DNA methylation in experimental models of hepatic fibrosis have not been fully addressed. Here, we analyzed isolated hepatic macrophages DNA methylation from CCL4-induced (4 weeks) mice using reduced representation bisulfite sequencing (RRBS). We identified and validated the methylation status of 26 gene promoter regions associated with CpG islands. We further investigated the function of PSTPIP2 in HF by hepatic-adeno-associated virus (AAV9)-PSTPIP2 overexpression. The molecular mechanisms underlying PSTPIPS2-regulated HF were further explored in mice and RAW264.7 cell line. RRBS results show hypermethylation of PSTPIP2 (chr18: 77,843,840-77,843,968) in the 5'-UTR region. PSTPIP2 expression was significantly decreased in isolated hepatic macrophages from CCL4-induced mice. PSTPIP2 hypermethylation is mediated by the methyltransferases DNMT3a and DNMT3b in LPS-induced RAW264.7 cell line. Further investigation indicated that specific overexpression of PSTPIP2 in C57BL/6 mice reduced the inflammatory response and ameliorated liver fibrosis. These data indicated that hypermethylation of PSTPIP2 caused a mixed induction of hepatic classical macrophage (M1) and alternative macrophage (M2) biomarkers in CCL4-induced HF mice. Furthermore, overexpression of PSTPIP2 inhibited the expression of M1 markers by suppressing STAT1 activity, and enhanced the expression of M2 markers by promoting STAT6 activity. In contrast, knockdown of PSTPIP2 promoted M1 polarization and suppressed M2 polarization in vitro. Adding PSTPIP2 expression alleviates liver fibrosis and hepatic inflammation in mice by regulating macrophage polarization.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Organic–inorganic silver halide hybrids show abundant phase transitions and thermochromism. However, it is very rare that silver halides exhibit thermochromism related to thermotropic structure phase ...transition. Herein, a bromoargentate hybrid, Pr-dabco2Ag4Br6 (1) (Pr-dabco+ = 1-propyl-1,4-diazabicyclo-2.2.2octan-1-ium), with tetranuclear Ag4Br62– clusters was prepared and characterized by microanalysis, ultraviolet–visible (UV–vis) diffuse reflectance spectroscopy, and thermogravimetric (TG) and differential scanning calorimetry (DSC) techniques. Interestingly, 1 undergoes an irreversible structure phase transition at ∼436 K in the first heating process, which is accompanied by an abrupt color change from colorless to yellow; however, a reversible color change between pale yellow and yellow is observed in the next heating–cooling cycles. Notably, DSC measurement revealed that a reversible phase transition is associated with the change in color between pale yellow and yellow, while the powder X-ray diffraction (PXRD) patterns corresponding to pale yellow and yellow phases are quite similar to each other. These observations demonstrate that thermochromism in the next heating–cooling runs is associated with a reversible structure phase transition, which perhaps concerns the disorder–order transformation of alkyl chains in the cationic ligand Pr-dabco+, and relevant to the anharmonic fluctuations of the Ag–Br and Ag–N bonds, a strong electron–phonon coupling effect is seen within the bromoargentate cluster.
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IJS, KILJ, NUK, PNG, UL, UM
Background： How to evaluate the quality of donation after cardiac transplantation in China. Hence, the aim of this study was to develop kidneys before DCD. death （DCD） kidneys has become a critical ...problem in kidney a simple donor risk score model to evaluate the quality of DCD Methods： A total of 543 qualified kidneys were randomized in a 2：1 manner to create the development and validation cohorts. The donor variables in the development cohort were considered as candidate univariate predictors of delayed graft function （DGF）. Multivariate logistic regression was then used to identify independent predictors of DGF with P 〈 0.05. Date from validation cohort were used to validate the donor scoring model. Results： Based on the odds ratios, eight identified variables were assigned a weighted integer; the sum of the integer was the total risk score for each kidney. The donor risk score, ranging from 0 to 28, demonstrated good discriminative power with a C-statistic of 0.790. Similar results were obtained from validation cohort with C-statistic of 0.783. Based on the obtained frequencies of DGF in relation to different risk scores, we formed tour risk categories of increasing severity （scores 04, 5 9, 10-14, and 15 28）. Conclusions： The scoring model might be a good noninvasive tool for assessing the quality of DCD kidneys before donation and potentially useful for physicians to make optimal decisions about donor organ offers.
Delayed graft function (DGF) is an important complication of kidney transplantation and can be diagnosed according to different definitions. DGF has been suggested to be associated with the long-term ...outcome of kidney transplantation surgery. However, the best DGF definition for predicting renal transplant outcomes in Chinese donations after cardiac death (DCDs) remains to be determined.
A total of 372 DCD kidney transplant recipients from June 2013 to July 2017 in the First Affiliated Hospital of Xi'an Jiaotong University were included in this retrospective study to compare 6 different DGF definitions. The relationships of the DGF definitions with transplant outcome were analyzed, including graft loss (GL) and death-censored graft loss (death-censored GL). Renal function indicators, including one-year estimated glomerular filtration rate (eGFR) and three-year eGFR, and were compared between different DGF groups.
The incidence of DGF varied from 4.19 to 35.22% according to the different DGF diagnoses. All DGF definitions were significantly associated with three-year GL as well as death-censored GL. DGF based on requirement of hemodialysis within the first week had the best predictive value for GL (AUC 0.77), and DGF based on sCr variation during the first 3 days post-transplant had the best predictive value for three-year death-censored GL (AUC 0.79). Combination of the 48-h sCr reduction ratio and classical DGF can improve the AUC for GL (AUC 0.85) as well as the predictive accuracy for death-censored GL (83.3%).
DGF was an independent risk factor for poor transplant outcome. The combination of need for hemodialysis within the first week and the 48-h serum creatinine reduction rate has a better predictive value for patient and poor graft outcome.
A simple and efficient method for transition‐metal‐free N‐arylation of various amines by triarylsulfonium triflates is described. Both aliphatic and aromatic amines were smoothly converted at 80 °C ...in the presence of tBuOK or KOH to give the corresponding mono N‐arylated products in good to high yields. The molar ratios of the reactants and the choice of bases had a big effect on the reaction. When a large excess of Ph3SOTf and tBuOK were employed for primary amines under the standard conditions, the bis(N‐phenyl) products were predominantly formed. This method was also applicable to the synthesis of bioactive N‐phenyl amino acid derivatives. The control experiments, the deuterium labelling study, and the presence of regioisomers of N‐arylated products when using 4‐substituted triarylsulfonium triflates suggested that the reaction might proceed through an aryne intermediate. The present protocol demonstrated that triarylsulfonium salts are versatile arylation reagents in the construction of CAr−N bonds.
Transition‐metal‐free N‐arylation of aliphatic and aromatic amines by Ar3SOTf in the presence of tBuOK or KOH gave the mono N‐arylated products in good to high yields. The reaction might proceed via an aryne intermediate. The molar ratios of the reactants and the choice of bases had a big influence on the reaction. When a large excess of Ph3SOTf and tBuOK were employed for primary amines, the corresponding bis(N‐phenyl) compounds were obtained as the major products.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Rickettsia raoultii is frequently detected in multiple tick species, whereas human infection remains scarcely studied.
A surveillance study was performed at 3 sentinel hospitals in China, to recruit ...participants with suspected tick exposure. Rickettsia raoultii infection was identified through polymerase chain reaction, followed by sequencing, and confirmed serologically. Isolation by cell culture was performed and the isolates were genome sequenced.
Twenty-six subjects were determined to have R. raoultii infection, including 7 with asymptomatic infection, 15 with mild to moderate illness, and 4 with severe illness. Common nonspecific manifestations in the 19 patients with mild to moderate or severe illness included fever (100%), malaise (95%), myalgia (58%), lymphadenopathy (53%), and nausea (42%). Only 5% of them had rash, and 16% had eschar. Scalp eschar and neck lymphadenopathy after a tick bite syndrome was only seen in 2 patients. Of the 4 patients with severe complications, 3 developed pulmonary edema, and 1 developed clouding of consciousness and lethargy. Frequent abnormalities of laboratory testing included leukopenia, thrombocytopenia, lymphopenia, neutropenia, hypoproteinemia, and elevated levels of total bilirubin, hepatic aminotransferases, lactate dehydrogenase, and creatine kinase. All the 19 patients recovered without sequelae after receiving doxycycline treatment. Two R. raoultii strains were isolated, and a significantly less degraded genome was observed than other more virulent Rickettsia strains, indicating a low pathogenicity of the current strain.
Human infection with R. raoultii has a wide clinical spectrum that ranged from subclinical infection to severe complications. Physicians need to be aware of the high potential and clinical complexity of R. raoultii infection, to ensure appropriate testing and treatment in endemic regions.
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BFBNIB, NUK, PNG, UL, UM, UPUK
Methyl-CpG-binding protein 2 (MeCP2) encoded by the
gene is a transcriptional regulator whose mutations cause Rett syndrome (RTT).
-deficient mice show fear regulation impairment; however, the ...cellular and molecular mechanisms underlying this abnormal behavior are largely uncharacterized. Here, we showed that
gene deficiency in cholinergic interneurons of the nucleus accumbens (NAc) dramatically impaired fear learning. We further found that spontaneous activity of cholinergic interneurons in
-deficient mice decreased, mediated by enhanced inhibitory transmission via α2-containing GABA
receptors. With MeCP2 restoration, opto- and chemo-genetic activation, and RNA interference in ChAT-expressing interneurons of the NAc, impaired fear retrieval was rescued. Taken together, these results reveal a previously unknown role of MeCP2 in NAc cholinergic interneurons in fear regulation, suggesting that modulation of neurons in the NAc may ameliorate fear-related disorders.
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