妊娠高血压综合征患者分娩前后血管内皮功能的高频超声研究

目的研究妊娠高血压综合征(PIH)患者分娩前后肱动脉内皮依赖性血管舒张功能变化。方法高频超声检测146例PIH患者(研究组)分娩前(孕28~40周)、分娩后6周右侧肱动脉血管内皮功能,对照组为100例健康生育期妇女。测量静息状态下右侧肱动脉内径(D1)、血流量(Q1)以及反应性充血后内径(D2)、血流量(Q2);计算内径变化率(△D%)、血流量变化率(△Q%)。结果研究组分娩前、分娩后6周肱动脉△D%及△Q%与对照组比较,差异有统计学意义(P<0.05),研究组均低于对照组;研究组分娩前与分娩后6周肱动脉△D%及△Q%比较,差异无统计学意义(P>0.05);分娩前、分娩后6周妊娠期高血压组与轻度子痫前期组肱动脉△D%及△Q%比较,差异无统计学意义(P>0.05),两组肱动脉△D%及△Q%与重度子痫前期组比较,差异有统计学意义(P<0.05),均低于重度子痫前期组。结论 PIH患者分娩前即存在内皮依赖性血管舒张功能受损,并至少持续至分娩后6周无改善和恢复;重度子痫前期患者分娩前后血管内皮功能受损程度均重于妊娠期高血压及轻度子痫前期患者。

Multiple primary malignant tumors of upper gastrointestinal tract:A novel role of ^(18)F-FDG PET/CT

AIM: To evaluate the capacity of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) for detecting multiple primary cancer of upper gastrointestinal (UGI) tract. METHODS: Fifteen patients (12 without cancer histories and 3 with histories of upper GI tract cancer) were investigated due to the suspicion of primary cancer of UGI tract on X-ray barium meal and CT scan. Subsequent whole body 18F-FDG PET/CT scan was carried out for initial staging or restaging. All the patients were fi nally confi rmed by endoscopic biopsy or surgery. The detection rate of multiple primary malignant cancers was calculated based on 18F-FDG PET/CT and endoscopic examinations.RESULTS: 18F-FDG PET/CT scan was positive in 32 suspicious lesions, 30/32 were true positive primary lesions, and 2/32 were false positive. In 15 suspicious lesions with negative 18F-FDG PET/CT scan, 12/15 were true negative and 3/15 were false negative. Among the 15 patients, 12 patients had 29 primary synchronous tumors confirmed by pathology, including 8 cases of esophageal cancers accompanied with gastric cancer and 4 of hypopharynx cancers with esophageal cancer. The other 3 patients had 4 new primary metachronous tumors, which were multiple primary esophageal cancers. PET/CT imaging detected local lymph node metastases in 11 patients. Both local lymph node metastases and distant metastases were detected in 4 patients. On a per-primary lesion basis, the sensitivity, specificity, accuracy, negative predictive value and positive predictive value of 18F-FDG PET/CT for detecting multiple primary cancer of UGI tract were 90.9%, 85.7%, 89.4%, 80% and 93.7%, respectively. CONCLUSION: The whole body 18F-FDG PET/CT may play an important role in evaluating the multiple primary malignant tumors of UGI tract cancer.

Identification and characterization of cDNA sequences encoding the HIS3 and LEU2 genes of the fungus Alternaria tenuissima

Alternaria tenuissima is a fungus widely present in the environment and could cause diseases in plants and humans. In this study, through a yeast genetic approach, cDNA sequences were isolated and characterized for the AtHIS3 and AtLEU2 genes. AtHIS3 cDNA encodes a protein of 238 amino acids, while AtLEU2 cDNA encodes a protein of 363 amino acids. Based on the phylogenetic analysis of amino acid sequences of AtHis3p and AtLeu2p, A. tenuissima is closely related to the plant pathogenic fungus Phaeosphaeria nodorum. This study provides two genetic markers for studies of functions of genes regulating development, morphology, and virulence of A. tenuissima.

Engineering Pt heterogeneous catalysts for accelerated liquid–solid redox conversion in Li-S batteries

The shuttle effect caused by soluble lithium polysulfides (LiPSs) deteriorates multiphase transformation reaction kinetics of sulfur species,and gives rise to an unserviceable lithium-sulfur (Li-S) battery.Catalysis,as a process optimization approach,offers an option to eliminate the intrinsic issues.However,exploring and understanding the role of catalysts on electrode reaction remains critical bottlenecks,particularly as they are prone to continuous evolution under complex dynamic environment.Herein,platinum nanoparticles loaded on MXene nanosheets,as sulfur host,and the action of catalysts on the reaction process are investigated via ex-situ monitors upon solid–liquid–solid chemical transformation of sulfur species.These traces confirm that the high performance originates from electron transfer between catalysts and LiPSs,which lowers the nucleation barrier from liquid LiPSs to solid Li_(2)S/Li_(2)S_(2).Further,the accelerated liquid–solid conversion can alleviate the accumulation of LiPSs,and boost the reaction kinetics in Li-S batteries.The findings corroborate the electronic modulation between catalysts and LiPSs,which is a generalizable strategy to optimize energy conversion efficiency of Li-S batteries.

Preparation of Electrospun PVDF Nanofiber Composite Filter Medium and Its Application in Air Filtration

Nanofibrous media with both high particle interception efficiency and robust air permeability has broad technological applications in areas including individual protection, industrial security, and environmental governance. However, producing such filtration media has proven to be extremely challenging. Here we reported an approach to preparing and fabricating a polyvinylidene fluoride (PVDF) nanofiber composite filter medium composed of 2D PVDF nanofiber nets and a stable substrate via onestep electrospinning for effective air filtration. PVDF nanofibers are obtained by adjusting the electrospinning process. With the combined properties of ultrasmall diameter, high porosity, and a bonded scaffold, the resulting PVDF nanofiber composite filter medium exhibits a robust high filtration efficiency of 99.901%(equivalent to an F9 rating) for 0.4 mm particles and a long service life (a large dust holding capacity of 36 g/m^2) for ultrafine airborne particles based on the sieving principle and surface filtration behavior. The successful synthesis of PVDF nanofibers medium would not only make it a promising candidate for air filtration, but also provide new insights into the design and development of composite nanofiber structures for various applications.

Insulin induces PKC-dependent proliferation of mesenteric vascular smooth muscle cells from hypertensive patients

Background and objectives Proliferation of human vascular smooth muscle cells (VSMCs) induced by hyperinsulinemia is a very common clinical pathology. Extensive research has focused on PKC (Protein kinase C)-MAPK (mitogen-activated protein kinase)intracellular signal transduction and the phenotypic modulation accompanied by reorganization of intracellular F-actins in VSMCs.Methods DNA synthesis, signaling of ERK1/2 MAPKs, and changes in α-smooth muscle (SM) actin and F-actin were studied in hypertensive and normotensive human arterial VSMCs exposed to insulin and PMA with and without the PKC inhibitor, GF109203X.Results Differences among cell types in MAPK signaling, α-SM actin, and F-actin isoforms in VSMCs harvested from the arteries of patients with essential hypertension (EH) and normotension (NT) were identified in response to insulin treatment. Proliferation and activation of MAPK were more pronounced in EH VSMCs than in NEH VSMCs. Insulin exposure decreased expression of α-SM actin and was accompanied by rearrangement of intracellular F-actins in VSMCs, especially in the EH group. These effects were reversed by treatment with the PKC inhibitor. Conclusions Human mesenteric VSMCs of EH and NT patients differed in proliferation, MAPK signaling, and degree of changes in α-SM actin and F-actin isoforms immediately following insulin exposure in vitro.

The self-assembly of gold nanoparticles in large-pore ordered mesoporous carbons

Simple encapsulation of 3 nm gold nanoparticles in ordered mesoporous carbon with large pores of 17 nm and thick pore walls of 16 nm was achieved by a metal–ligand coordination assisted-selfassembly approach.Polystyrene-block-polyethylene-oxide(PS-b-PEO)diblock copolymer with a large molecular weight of the PS chain and mercaptopropyltrimethoxysilane were used as the template and the metal ligand,respectively.Small-angle X-ray scattering,X-ray diffraction,transmission electron microscopy,and X-ray photoelectron spectroscopy showed that monodispersed aggregation-free gold nanoparticles approximately 3 nm in size were partially embedded in the large open pore structure of the ordered mesoporous carbon.The strong coordination between the gold species and the mercapto groups and the thick porous walls increased the dispersion of the gold nanoparticles and essentially inhibited particle aggregation at 600℃.The gold nanoparticles in the ordered mesoporous carbon are active and stable in the reduction of nitroarenes involving bulky molecules using sodium borohydride as a reducing agent under ambient conditions(30℃)in water.The large interconnected pore structure facilitates the mass transfer of bulky molecules.

Surgical treatment of malignant biliary papillomatosis invading adjacent organs: A case report

BACKGROUND Biliary papillomatosis(BP) is a rare disease characterized by multiple papillary adenomas in the intrahepatic and extrahepatic biliary tree and has a high risk of malignant transformation. Early diagnosis and treatment for BP are challenges, as it spreads along the biliary tract. A radical resection with an adequate resection margin is advocated in patients with malignant BP.CASE SUMMARY We report a case of BP with malignant transformation in a 52-year-old female patient who presented with emaciation, severe malnutrition, and a T-tube for biliary drainage that was placed for almost 2 years at the time she visited us. The enhanced magnetic resonance imaging of the upper abdomen revealed a neoplasm with a diameter of 15 cm located in the gallbladder area surrounding the common bile duct where a drainage tube was placed. It was the first case with malignant BP involving multiple organs and the abdominal wall and receiving a radical resection. Plastic surgeons helped close the incision by transferring the rectus muscle and external oblique muscle flap. A diagnosis of papillary carcinoma with diffuse malignant papillomatosis of the biliary duct was given.The postoperative course was uneventful and she was asymptomatic and in good physical condition at 35 mo postoperatively with appropriate chemotherapy.CONCLUSION Aggressive surgical treatment with appropriate chemotherapy is advocated for patients with malignant BP even if multiple organ invasion is present.

Research State of Disposable Nonplastic Straws

The continuous production of disposable plastic straw places a high demand on global petrochemical resources and a significant environmental burden.Biodegradable and eco-friendly straws have therefore been studied and produced worldwide.This article briefly introduces the characteristics of paper straws and polylactic acid(PLA)straws,and focuses on edible straws made using,e.g.,hydrophilic colloids,zein,and starch.Raw-material selection,preparation methods,advantages,and defects of straws are summarized,to provide a reference for the development and research of eco-friendly straws.

Mobile mini-fluorimeter for antibiotic aptasensing based on surface-plasmonic effect of burlike nanogolds enhanced by digitized imaging diagnosis

Antibiotic abuse now poses a grave threat to global ecology and bestirs public concerns about the residue issue in daily necessities.The traceability measurements along supply chain or logistic circulation have become increasingly essential given the labile nature of diverse synthetic residuals on site.In an attempt to answer this urgency,here a miniaturized fluorometric aptasensor prototype was contrived that catered to the point-of-care screening norm for two typical additives:chloramphenicol and enrofloxacin.The key target-indicating module worked in vitro based on the competitive binding-induced fluorescence recovery of fluorescein-labeled aptamers,which were photobleached beforehand in the format of double helix on burlike nanogold carriers.The“prickly”geometry of the latter not just enriched the capture probes at preferentially substrate-accessible spires;but also contributed to a tip-enhanced surface plasmon effect,sensitizing the signal-on during the duplex dissociation even at nanomolar threshold of the analytes.On the other hand,to encompass a full portable,a set of optical devices were mounted within a 3D-printed cartridge(adaptor)to converge the light beam and route it towards the detector,for which the smartphone camera came up in handy with a home-developed App for calibrating the emissive brightness.Enlightened by the high-dynamic-range compression,an imaging diagnostic algorithm was built in to grid and digitize each slide in the album for augmented detection performance.Thus,a novel bio-to-silico integration was invented that capable of in situ rapid reporting on the antibiotic presence with high sensitivity and selectivity.Further field practices in spiked milk on sales proved the precision and rudimentary feasibility of the well-assembled model of appliance,thus holding nice prospects in nonexpert(e.g.,family and local community)utilities for foodborne antibiotic identification.

Knockdown of SIRT2 Rescues YARS-induced Charcot-Marie-Tooth Neuropathy in Drosophila

Dear Editor,Charcot-Marie-Tooth disease,the most common inherited peripheral neuropathology,is highly heterogeneous among patients and associated with mutations in~100 different genes at an incidence of at least 1:2,500[1].Over 30 mutated genes have been identified in CMT2,which is characterized by peripheral axon degeneration and distal deficits in motor function[2].The aminoacyl-tRNA synthetase is the largest family in CMT2 and includes tyrosyl-tRNA synthetase(YARS,tyrosyl-tRNA synthetase).

Point-of-Care Testing of Chloramphenicol in Food Production Using Smartphone-Based Electrochemical Detector

Antibiotic abuse in food processing could threaten human health via either direct pathogen or drug-resistant infection.To curb this situation,it is of vital significance to identify trace level of antibiotics in foodstuffin a point-of-care inspection manner.Here,a smartphone-based electrochemical system was developed for the quantitation of chloramphenicol(CAP).The differential pulse voltammetric reduction of CAP was measured facilely on a piece of gold-deposited screen-printed electrode,which was docked onto a palm-sized detector with remote directives from a mobile APP of Bluetooth handshaking and digital display.Under optimal conditions,the target CAP could be determined in a range from 1 nmol/L to 5μmol/L with a detection limit of 0.25 nmol/L.Further tests on emulate samples demonstrated the miniaturized device could handle the food-screening scenarios with accuracy,convenience and quick response.

Electrochemical analysis of microRNAs with hybridization chain reaction-based triple signal amplification

Selective and sensitive detection of trace microRNA is important for early diagnosis of diseases due to its expression level related to diseases.Herein,a triple signal amplification strategy is developed for trace microRNA-21 (miRNA-21) detection by combining with target-triggered cyclic strand displacement reaction (TCSDR),hybridization chain reaction (HCR) and enzyme catalytic amplification.Four DNA hairpins(H1,H2,H3,H4) are employed to form an ultralong double-strand DNA (dsDNA) structure,which is initiated by target miRNA-21.As H3 and H4 are labeled with horseradish peroxidase (HRP),numerous HRPs are loaded on the long dsDNA,producing significantly enhanced electrocatalytic signals in the hydrogen peroxide (H_(2)O_(2)) and 3,3,5,5-tetramethylbenzidine (TMB) reaction strategy.Compared with single signal amplification,the triple signal amplification strategy shows higher electrochemical response,wider dynamic range and lower detection limit for miRNA-21 detection with excellent selectivity,reproducibility and stability.Taking advantage of the triple signal amplification strategy,the proposed electrochemical biosensor can detect miRNA-21 in 10 He La cell lysates,suggesting that it is a promising method for fruitful assay in clinical diagnosis.

Aptamer-wrapped gold nanoparticles for the colorimetric detection of omethoate

Organophosphorous pesticide(OP) contamination has serious adverse effects on human health and the environment. Due to the toxicity of OPs and the threat presented by their accidental or intentional release in populated areas, the determination and monitoring of these OPs in food products and environment is of great importance. OPs are present in very small quantities and therefore, methods for their detection need to be highly sensitive and selective. Here, we aimed to develop a simple and selective aptamer-based colorimetric assay for the detection of omethoate, which is one of the commonly used OPs. The principle of the assay is that single-stranded DNA(ss DNA)-wrapped gold nanoparticles(Au NPs) are resistant to salt-induced aggregation. By employing an "artificial antibody" organophosphorous pesticide-binding aptamer(OBA) as the recognition element, aptamer-wrapped Au NPs(Au-apta) show high selectivity towards omethoate, resulting in the disconnection of aptamers from Au NPs and the aggregation of Au NPs. As there is a significant color change from the interparticle plasmon coupling during the aggregation of Au NPs, the established assay showed good linearity between 0.1 and 10 μmol/L, with a low detection limit of 0.1 μmol/L. Other OPs such as profenofos, phorate, and isocarbophos would not interfere with the detection of omethoate despite having similar structures. Thus, the colorimetric method shows potential for use in the detection of omethoate in real soil samples.

国家自然科学基金化学测量学2018~2022年项目申请和评审综述

化学测量学旨在发展化学及相关学科的测量理论、原理、方法和技术,研制仪器、装置、软件及试剂,获取物质组成、结构、形貌、性质与功能等信息,揭示物质相互作用的分子基础和时空变化规律.从2018年起,国家自然科学基金委员会化学科学部进行了学科重组及代码调整,在原分析化学的基础上,形成了新的资助领域:化学测量学(基金申请代码:B04).本文详细总结并分析了自化学测量学新代码启用以来(2018~2022年)各类项目的申请和资助情况,包括面上项目、青年科学基金项目、地区科学基金项目、国家杰出青年科学基金、优秀青年科学基金、重大项目、重点项目和国家重大科研仪器研制项目等.同时,对目前该领域的发展现状进行了讨论,并对其未来发展提出了建议,供相关科研人员参考.

Over 255 mW single-frequency fiber laser with high slope efficiency and power stability based on an ultrashort Yb-doped crystal-derived silica fiber

A single-frequency distributed Bragg reflector (DBR) fiber laser at 1030 nm has been demonstrated using a 0.7 cm long homemade Yb:YAG crystal-derived silica fiber (YCDSF).The absorption and emission cross sections of the YCDSF are 4.93×10^(-20)cm^(2) at 980 nm and 1.1×10^(-20)cm^(2)at 1030 nm.Using this gain fiber,an over 255 m W continuous-wave lasing in the constructed laser has been obtained at single transverse and longitudinal mode operation.The slope efficiency and the pump threshold of the fiber laser were up to ~35%and as low as 25 m W,respectively.The fiber laser also demonstrated an optical signal-to-noise ratio of 79 dB and a beam quality factor of 1.016 in two orthogonal directions.Its power fluctuation at 210.5 m W was less than 0.85%of the average power within 13 h.Moreover,the relative intensity noise and linewidth of the laser are also investigated at the different pump powers.The results indicate that the single-frequency DBR fiber laser has potential applications in high-quality seed sources and high-precision optical sensing.

Conversion of effector CD4^(+)T cells to a CD8^(+)MHC Ⅱ-recognizing lineage

CD4^(+)and CD8^(+)T cells are dichotomous lineages in adaptive immunity.While conventionally viewed as distinct fates that are fixed after thymic development,accumulating evidence indicates that these two populations can exhibit significant lineage plasticity,particularly upon TCR-mediated activation.We define a novel CD4^(-)CD8αβ^(+)MHC Ⅱ-recognizing population generated by lineage conversion from effector CD4^(+)T cells.CD4-CD8αβ^(+)effector T cells downregulated the expression of T helper cell-associated costimulatory molecules and inaeased the expression of cytotoxic T lymphocyte-associated cytotoxic molecules.This shift in functional potential corresponded with a CD8^(+)-lineage skewed transcriptional profile.TCRβ repertoire sequencing and in vivo genetic lineage tracing in acutely infected wild-type mice demonstrated that CD4^(-)CD8αβ^(+)effector T cells arise from fundamental lineage reprogramming of bona fide effector CD4^(+)T cells.Impairing autophagy via functional deletion of the initiating kinase Vps34 or the downstream enzyme Atg7 enhanced the generation of this cell population.These findings suggest that effector CD4^(+)T cells can exhibit a previously unreported degree of skewing towards the CD8^(+)T cell lineage,which may point towards a novel direction for HIV vaccine design.

Intracellular Logic Computation with Framework Nucleic Acid-Based Circuits for mRNA Imaging

Main observation and conclusion DNA circuits have been designed for implementation of various functions based on DNA strand displacement in cell-free settings,but their capabilities in biological environments remain limited.In this work,we report framework nucleic acid(FNA)-based circuits enabling intracellular logic computation for mRNA imaging.FNAs as rigid scaffolds enable to deliver our built DNA circuits into cells without aid of transfection reagents,evading a time-consuming and tedious process prior to analysis,and the pendant duplex DNA designed at one vertex of FNA as gate is suitable for four-way strand exchange,minimizing crosstalk with other nucleic acids in the cellular milieu.We demonstrated that such FNA-based circuits can operate both in vitro and in vivo logic computation,including OR and AND logic gates.Moreover,in situ mRNA imaging was also realized by exploiting native mRNA as scaffolds to bind multiple FNA-based gates for the enhanced signal-to-background ratio.We hope that this FNA-based circuit can be applied for disease diagnosis,facilitating the development of biomedicine.

The role of microRNAs in B-cell development and function

MicroRNA （miRNA）-mediated gene silencing at the translational level has led to novel discoveries for numerous biological processes. Recently, there has been increasing evidence to indicate that miRNAs are involved in normal immune functions and inflammation. In this review, we focus on recent advances that have elucidated the role of miRNAs in B-cell development, differentiation, apoptosis and function. While the regulatory mechanisms of miRNAs in controlling and maintaining B-cell fate remain largely uncharacterized, further studies on miRNAs and their targets will increase our understanding of B-cell development and function. Such studies may be able to provide new therapeutic strategies for treating autoimmune diseases.

The kinase p38αfunctions in dendritic cells to regulate Th2-cell differentiation and allergic inflammation

Dendritic cells(DCs)play a critical role in controlling T helper 2(Th2)cell-dependent diseases,but the signaling mechanism that triggers this function is not fully understood.We showed that p38αactivity in DCs was decreased upon HDM stimulation and dynamically regulated by both extrinsic signals and Th2-instructive cytokines.p38α-specific deletion in cDC1s but not in cDC2s or macrophages promoted Th2 responses under HDM stimulation.Further study showed that p38αin cDC1s regulated Th2-cell differentiation by modulating the MK2−c-FOS−IL-12 axis.Importantly,crosstalk between p38α-dependent DCs and Th2 cells occurred during the sensitization phase,not the effector phase,and was conserved between mice and humans.Our results identify p38αsignaling as a central pathway in DCs that integrates allergic and parasitic instructive signals with Th2-instructive cytokines from the microenvironment to regulate Th2-cell differentiation and function,and this finding may offer a novel strategy for the treatment of allergic diseases and parasitic infection.