Outcomes of endoscopic sclerotherapy for jejunal varices at the site of choledochojejunostomy (with video): Three case reports

BACKGROUND Hemorrhage associated with varices at the site of choledochojejunostomy is an unusual,difficult to treat,and often fatal manifestation of portal hypertension.So far,no treatment guidelines have been established.CASE SUMMARY We reported three patients with jejunal varices at the site of choledochojejun-ostomy managed by endoscopic sclerotherapy with lauromacrogol/α-butyl cyanoacrylate injection at our institution between June 2021 and August 2023.We reviewed all patient records,clinical presentation,endoscopic findings and treatment,outcomes and follow-up.Three patients who underwent pancre-aticoduodenectomy with a Whipple anastomosis were examined using conven-tional upper gastrointestinal endoscopy for suspected hemorrhage from the afferent jejunal loop.Varices with stigmata of recent hemorrhage or active he-morrhage were observed around the choledochojejunostomy site in all three patients.Endoscopic injection of lauromacrogol/α-butyl cyanoacrylate was carried out at jejunal varices for all three patients.The bleeding ceased and patency was observed for 26 and 2 months in two patients.In one patient with multiorgan failure and internal environment disturbance,rebleeding occurred 1 month after endoscopic sclerotherapy,and despite a second endoscopic sclero-therapy,repeated episodes of bleeding and multiorgan failure resulted in eventual death.CONCLUSION We conclude that endoscopic sclerotherapy with lauromacrogol/α-butyl cyanoac-rylate injection can be an easy,effective,safe and low-cost treatment option for jejunal varicose bleeding at the site of choledochojejunostomy.

A prognosis model for predicting immunotherapy response of esophageal cancer based on oxidative stress-related signatures

Oxidative stress(OS)is intimately associated with tumorigenesis and has been considered a potential therapeutic strategy.However,the OS-associated therapeutic target for esophageal squamous cell carcinoma(ESCC)remains unconfirmed.In our study,gene expression data of ESCC and clinical information from public databases were downloaded.Through LASSO-Cox regression analysis,a risk score(RS)signature map of prognosis was constructed and performed external verification with the GSE53625 cohort.The ESTIMATE,xCell,CIBERSORT,TIMER,and ImmuCellAI algorithms were employed to analyze infiltrating immune cells and generate an immune microenvironment(IM).Afterward,functional enrichment analysis clarified the underlying mechanism of the model.Nomogram was utilized for forecasting the survival rate of individual ESCC cases.As a result,we successfully constructed an OS-related genes(OSRGs)model and found that the survival rate of high-risk groups was lower than that of low-risk groups.The AUC of the ROC verified the strong prediction performance of the signal in these two cohorts further.According to independent prognostic analysis,the RS was identified as an independent risk factor for ESCC.The nomogram and follow-up data revealed that the RS possesses favorable predictive value for the prognosis of ESCC patients.qRT-PCR detection demonstrated increased expression of MPC1,COX6C,CYB5R3,CASP7,and CYCS in esophageal cancer patients.In conclusion,we have constructed an OSRGs model for ESCC to predict patients’prognosis,offering a novel insight into the potential application of the OSRGs model in ESCC.

Evolution of Superconducting-Transition Temperature with Superfluid Density and Conductivity in Pressurized Cuprate Superconductors

What factors fundamentally determine the value of superconducting transition temperature Tc in high temperature superconductors has been the subject of intense debate.Following the establishment of an empirical law known as Homes'law,there is a growing consensus in the community that the Tc value of the cuprate superconductors is closely linked to the superfluid density(ρ_(s))of its ground state and the conductivity(σ)of its normal state.However,all the data supporting this empirical law(ρ_(s)=AσT_(c))have been obtained from the ambientpressure superconductors.In this study,we present the first high-pressure results about the connection of the quantities of ρ_(s) and σ with T_(c),through the studies on the Bi_(1.74)Pb_(0.38)Sr_(1.88)CuO_(6+δ)and Bi_(2)Sr_(2)CaCu_(2)O_(8+δ),in which the value of their high-pressure resistivity(ρ=1/σ)is achieved by adopting our newly established method,while the quantity ofρs is extracted using Homes'law.We highlight that the Tc values are strongly linked to the joint response factors of magnetic field and electric field,i.e.,ρ_(s) and σ,respectively,implying that the physics determining T_(c) is governed by the intrinsic electromagnetic fields of the system.

Thirty-year trends of anxiety disorders among adolescents based on the 2019 Global Burden of Disease Study

Background Anxiety disorders are the most common psychiatric problems,affecting approximately 1 in 12 children and 1 in 4 adolescents.Understanding the incidence,burden and correlated risks of anxiety disorders among children and adolescents can help identify areas of success,stagnation and emerging threats,thereby facilitating effective improvement strategies.Aims To estimate the incidence and burden trends of anxiety disorders in children and adolescents from 1990 to 2019 in 204 countries and compare the incidence and disease burden in different countries.To examine the association between anxiety disorders and social indicators(healthcare access and quality of life).Methods Data were obtained from the Global Burden of Disease Study 2019.The age-standardised incidence rates(ASIRs)and disability-adjusted life years(DALYs)were reported to assess the burden of anxiety disorders,and the estimated annual percentage change was calculated to quantify the temporal trends.Pearson’s correlation was used to investigate country-level risk factors for incidence and DALYs.Results Globally,there were 932 million incident cases of anxiety disorders in children and adolescents,739.29 per 100000 ASIRs and 380.62 million DALYs in 2019.From 1990 to 2019,the estimated annual percentage change of incidence of anxiety disorders decreased by 2.2%.Significant variations were observed in the age-standardised burden rate and the changing trend of anxiety disorders among countries.Portugal reported the highest ASIR of anxiety disorders,while Mexico had the largest increase rate of ASIR.In 2019,Portugal reported the highest number of DALYs(1001.71 million),and India(212.09 million)reported the lowest number of DALYs.The burden of anxiety disorders was positively correlated with the average number of psychiatrists,psychologists and nurses in the mental health sector(per 100000),and quality of life and the correlation coefficients were 0.58,0.67,0.43 and 0.53,respectively.Conclusions The incidence and global burden of anxiety disorders in adolescents have continued to decrease over the past 30 years.However,the incidence and disease burden in developed countries are still increasing steadily.Policymakers should design and implement mental health strategies for adolescents based on their specific developmental status,as well as the cultural and regional characteristics of each country.

Numerical Analysis of Cold-Formed Thin-Walled Steel Short Columns with Pitting Corrosion during Bridge Construction

Pitting corrosion is harmful during bridge construction,which will lead to uneven roughness of steel surfaces and reduce the thickness of steel.Hence,the effect of pitting corrosion on the mechanical properties of cold-formed thin-walled steel stub columns is studied,and the empirical formulas are established through regression fitting to predict the ultimate load of web and flange under pitting corrosion.In detail,the failure modes and load-displacement curves of specimens with different locations,area ratios,and depths are obtained through a large number of non-linear finite element analysis.As for the specimens with pitting corrosion on the web,all the specimens are subject to local buckling failure,and the failure mode will not change with pitting corrosion,but the failure location will change with pitting corrosion location;the size,location,and area ratio of pitting corrosion have little influence on the ultimate load of cold-formed thin-walled steel short columns,but the loss rate of pitting corrosion section area has a greater impact on the ultimate bearing capacity.As for the specimen with flange pitting corrosion,the location and area ratio of pitting corrosion have less influence on the ultimate load of cold-formed thin-walled steel short columns,and the section area loss rate has greater influence on the ultimate bearing capacity;the impact of web pitting corrosion on the ultimate load is greater than that of flange pitting corrosion under the same condition of pitting corrosion section area.The prediction formulas of limit load which are suitable for pitting corrosion of web and flange are established,which can provide a reference for performance evaluation of corroded cold-formed thin-walled steel.

Echinacoside attenuates glandular fibrosis in benign prostatic hyperplasia via inhibiting MKK6/MK2 signaling pathway

Background:Lower urinary tract symptoms commonly occur in the elderly population and seriously constrain the quality of life.Glandular fibrosis is an important pathobiological process in benign prostatic hyperplasia and is also a main inducing factor for benign prostatic hyperplasia-associated lower urinary tract symptoms.Cistanches species is an important herbal medicine resource and is traditionally used in ameliorating renal and prostatic defects.Methods:This study was to investigate the potential protective function of echinacoside(a bioactive compound from Cistanches)against prostatic fibrosis in mice and human benign prostatic hyperplasia epithelial-1 cell models.Results:It was found that echinacoside attenuated testosterone-induced prostatic hyperplasia and collagen deposition in mice,relieved prostate local inflammation and oxidative damage,and ameliorated prostatic epithelial-mesenchymal transition.Additionally,echinacoside inhibited the activation of the MKK6/MK2 signaling pathway both in vivo and in vitro.Conclusion:This study added new evidence for the anti-fibrotic function of echinacoside on the prostate and provided new insights for understanding its possible pharmacological mechanisms.

四种人工晶状体计算公式在超高度近视并发白内障患者中的应用

目的:评估SRK/T、Haigis、Barrett UniversalⅡ、Wang-Koch修正SRK/T公式在超高度近视并发白内障手术中应用的准确性。方法:收集2020-01/2021-06于我院行白内障超声乳化+张力环植入联合人工晶状体植入术的超高度近视并发白内障患者44例52眼,术前采用SRK/T、Haigis、Barrett UniversalⅡ公式及Wang-Koch修正SRK/T公式分别计算术后预留屈光度,术后3mo进行综合验光测量实际屈光度。获得四种公式的平均绝对屈光误差(MAE),评价各公式的准确性。结果:SRK/T公式、Haigis公式、Barrett UniversalⅡ公式、Wang-Koch修正SRK/T公式MAE分别为0.86(0.56,1.20)、0.79(0.56,1.16)、0.68(0.30,0.87)、0.65(0.43,0.75)D,其中SRK/T公式和Haigis公式MAE均显著高于Barrett UniversalⅡ公式和Wang-Koch修正SRK/T公式(P<0.01)。根据术前角膜曲率(K)将纳入患者分为K>46D组(12眼)、44D<K≤46D组(24眼)、K≤44D组(16眼),三组患者SRK/T公式和Haigis公式MAE均显著高于Barrett UniversalⅡ公式和Wang-Koch修正SRK/T公式(P<0.01)。根据术前眼轴长度(AL)将纳入患者分为AL≤30mm组(24眼)、AL>30mm(28眼)组,两组患者SRK/T公式和Haigis公式MAE均显著高于Barrett UniversalⅡ公式和Wang-Koch修正SRK/T公式(P<0.05)。结论:采用Wang-Koch修正SRK/T公式和Barrett UniversalⅡ公式预测超高度近视并发白内障患者人工晶状体度数准确性更高。

电化学氮还原氨反应催化剂的最新研究进展

氨是重要的化工产品之一,广泛应用于化肥和燃料生产等领域.目前我国仍采用传统的Haber-Bosch工艺合成氨,该工艺消耗大量的化石燃料并造成环境污染.因此,开发一种高效、环保的氨合成方法代替Haber-Bosch工艺,减少能源消耗和保护环境具有非常重要的意义.电化学氮还原(eNRR)工艺由于使用可再生能源,成为有前景的替代方法之一.但目前eNRR工艺面临着许多挑战:较大的过电位以及析氢反应都会导致氨合成反应性能不理想.因此,理性设计电催化剂以提高氨合成效率成为当务之急.本文总结了近年e NRR领域的最新进展,以期为开发高性能催化剂提供借鉴.本文从eNRR的反应机理入手,介绍了eNRR的检测方法和反应条件,总结了近年来电催化剂的设计策略、原位表征方法和理论计算的研究成果,并对领域未来发展进行展望.首先,从理论热力学和NH3检测等方面讨论了eNRR的关键难点.然后,从形态、结构、空位、掺杂、协同效应、异质结构和单原子等多方面总结了eNRR催化剂的设计策略.此外,介绍了原位拉曼、原位红外、原位电化学质谱和原位X射线吸收光谱等技术在电催化氮还原机理研究中的重要作用.讨论了密度泛函理论(DFT)对于研究eNRR过程中的反应能垒和催化剂电子轨道分布的重要作用.最后,介绍了当前eNRR所面临的挑战,并就如何提高NH3产率和选择性提出了建议,如采用流动电解槽中固-液-气三相界面设计可确保N_(2)与催化剂之间有更大的接触面积和更长的接触时间,从而提高N2转化率;改变电解液成分或催化反应条件等方式以延长催化剂的使用寿命;通过原位表征手段对催化反应过程进行实时监测,以进一步揭示催化机理等.综上,eNRR领域取得的进展说明了在水溶液中通过可再生的电力将N_(2)还原成NH_3具有可行性.尽管现阶段存在eNRR效率不高、工艺不成熟等问题,但随着理论研究与实验结果的更好结合,原位表征技术的进一步发展和应用,未来在高效、稳定的氨合成电催化剂设计方面将会取得更大的进展,进而实现绿色合成氨的工业化应用,为减少能源消耗和碳排放做出贡献.

化学本科生课外阅读的现状与思考——基于湖南省属六所高校的调查

基于2003年和2013年对湖南省6所高校化学本科生开展课外阅读情况的调查,于2021年再次开展了同质性调查和对比分析,发现化学专业在校大一到大三学生中存在课外阅读量下降、不重视期刊阅读、忽视图书馆借阅功能等问题。据此提出新生教育突出引导、课堂教学加强渗透、课外创新养成习惯和社团活动以赛促读等策略和建议。

Impact of cirrhosis-related complications on posttransplant survival in patients with acute-on-chronic liver failure

Background:Acute-on-chronic liver failure(ACLF)is a life-threatening syndrome defined as acute decompensation in patients with chronic liver disease.Liver transplantation(LT)is the most effective treatment.We aimed to assess the impact of cirrhosis-related complications pre-LT on the posttransplant prognosis of patients with ACLF.Methods:This was an observational cohort study conducted between January 2018 and December 2020.Clinical characteristics,cirrhosis-related complications at LT and patient survival post-LT were collected.All liver recipients with ACLF were followed for 1 year post-LT.Results:A total of 212 LT recipients with ACLF were enrolled,including 75(35.4%)patients with ACLF-1,64(30.2%)with ACLF-2,and 73(34.4%)with ACLF-3.The median waiting time for LT was 11(4-24)days.The most prevalent cirrhosis-related complication was ascites(78.8%),followed by hepatic encephalopathy(57.1%),bacterial infections(48.1%),hepatorenal syndrome(22.2%)and gastrointestinal bleeding(11.3%).Survival analyses showed that patients with complications at LT had a significantly lower survival probability at both 3 months and 1 year after LT than those without complications(all P<0.05).A simplified model was developed by assigning one point to each complication:transplantation for ACLF with cirrhosis-related complication(TACC)model.Risk stratification of TACC model identified 3 strata(≥4,=3,and≤2)with high,median and low risk of death after LT(P<0.001).Moreover,the TACC model showed a comparable ability for predicting the outcome post-LT to the other four prognostic models(chronic liver failure-consortium ACLF score,Chinese Group on the Study of Severe Hepatitis B-ACLF score,model for end-stage liver disease score and Child-Turcotte-Pugh score).Conclusions:The presence of cirrhosis-related complications pre-LT increases the risk of death post-LT in patients with ACLF.The TACC model based on the number of cirrhosis-related complications pre-LT could stratify posttransplant survival,which might help to determine transplant timing for ACLF.

The Progress of IGS Analysis Center at Wuhan University

As one of the Analysis Centers(AC)of the International GNSS Service(IGS),Wuhan University(WHU)has been contributing to the IGS by providing ultra-rapid as well as rapid orbit and clock solutions for the established GPS and GLONASS since 2012.In the same year,the IGS initiated the Multi-GNSS Experiment(MGEX)to support the analysis of the emerging GNSS systems and prepare the IGS for Multi-GNSS,which includes GPS,GLONASS,the European Galileo system,the Chinese Beidou Navigation Satellite System(BDS),the Japanese Quasi-Zenith Satellite System(QZSS)and the Indian Regional Navigation Satellite System(IRNSS/NaVIC).The major products,i.e.,orbits,Earth Orientation Parameters(EOPs),satellite clock as well as attitude have also been provided by WHU since 2012.More recently,WHU has engaged the third reprocessing of IGS for generating the highly accurate station coordinates as inputs for establishment of the International Terrestrial Reference Frame(ITRF)2020 during 2019—2020.This article presents the recent major advancements of the IGS AC at Wuhan University,including precise products,real-time products,bias products,antenna phase center calibration,and the non-linear motion modeling for GNSS Reference Stations.

Influencing mechanism of saline sediments on pore system formation and evolution in terrestrial shales

The majority of oil and gas resources in the world are related to saline sediments, which mainly occur in sedimentary strata in the form of cap rocks or salt-associated shales. A large number of shale oil resources have been discovered in the saline shale sediments of the Cenozoic terrestrial lake basin in China. The hydrocarbon generation ability and the reservoir capacity of shale control the oil and gas generation. The reservoir capacity is mainly characterized by pore type, structure and porosity. Most of China’s shale oil and gas resources belong to salt-bearing formations. The role of gypsum-salt rocks in the formation and evolution of organic matter (OM) in such formations has received extensive attention. However, systematic understanding is lacking. Research on the pore formation and evolution in shale under the action of gypsum-salt rock sediments is especially weak. Taking the shales in the third member of the Shahejie Formation (Es_(3)) of the Bohai Bay Basin as an example, the influence of halite on the formation and evolution process of pores was studied in this paper. The results show that halite and gypsum minerals were associated with OM, which made them more likely to develop OM pores. The samples with a high halite mineral content (HC) are more developed regarding the pore volume and specific surface area than those with a low HC. The formation of thick salt rocks is influenced by factors of deep thermal brine upwelling, sea erosion and arid environments. The frequent alternation between humid and arid environments led to the outbreak and death of organisms and the precipitation of gypsum-salt rock, which formed the simultaneous deposition of OM and halite minerals. Finally, we have established a model of shale pore evolution under the participation of the gypsum-salt rock, and halite minerals contribute to pore development in both Stage II and Stage IV. This study provides strong microscopic evidence for the pore system formation and evolution in salt-bearing reservoirs.

Elevated extracellular calcium ions accelerate the proliferation and migration of HepG2 cells and decrease cisplatin sensitivity

Hepatoblastoma is the most frequent liver malignancy in children.HepG2 has been discovered as a hepatoblastoma-derived cell line and tends to form clumps in culture.Intriguingly,we observed that the addition of calcium ions reduced cell clumping and disassociated HepG2 cells.The calcium signal is in connection with a series of processes critical in the tumorigenesis.Here,we demonstrated that extracellular calcium ions induced morphological changes and enhanced the epithelial-mesenchymal transition in HepG2 cells.Mechanistically,calcium ions promoted HepG2 proliferation and migration by up-regulating the phosphorylation levels of focal adhesion kinase(FAK),protein kinase B,and p38 mitogen-activated protein kinase.The inhibitor of FAK or Ca2+/calmodulin-dependent kinaseⅡ(CaMKⅡ)reversed the Ca2+-induced effects on HepG2 cells,including cell proliferation and migration,epithelial-mesenchymal transition protein expression levels,and phosphorylation levels of FAK and protein kinase B.Moreover,calcium ions decreased HepG2 cells'sensitivity to cisplatin.Furthermore,we found that the expression levels of FAK and CaMKⅡwere increased in hepatoblastoma.The group with high expression levels of FAK and CaMKⅡexhibited significantly lower ImmunoScore as well as CD8+T and NK cells.The expression of CaMKⅡwas positively correlated with that of PDCD1 and LAG3.Correspondingly,the expression of FAK was negatively correlated with that of TNFSF9,TNFRSF4,and TNFRSF18.Collectively,extracellular calcium accelerates HepG2 cell proliferation and migration via FAK and CaMKⅡand enhances cisplatin resistance.FAK and CaMKⅡshape immune cell infiltration and responses in tumor microenvironments,thereby serving as potential targets for hepatoblastoma.

Defect Engineering of Disordered Carbon Anodes with Ultra-High Heteroatom Doping Through a Supermolecule-Mediated Strategy for Potassium-Ion Hybrid Capacitors

Amorphous carbons are promising anodes for high-rate potassium-ion batteries.Most low-temperature annealed amorphous carbons display unsatisfactory capacities.Heteroatom-induced defect engineering of amorphous carbons could enhance their reversible capacities.Nevertheless,most lignocellulose biomasses lack heteroatoms,making it a challenge to design highly heteroatom-doped carbons(>10 at%).Herein,we report a new preparation strategy for amorphous carbon anodes.Nitrogen/sulfur co-doped lignin-derived porous carbons(NSLPC)with ultra-high nitrogen doping levels(21.6 at%of N and 0.8 at%of S)from renewable lignin biomacromolecule precursors were prepared through a supramolecule-mediated pyrolysis strategy.This supermolecule/lignin composite decomposes forming a covalently bonded graphitic carbon/amorphous carbon intermediate product,which induces the formation of high heteroatom doping in the obtained NSLPC.This unique pyrolysis chemistry and high heteroatom doping of NSLPC enable abundant defective active sites for the adsorption of K+and improved kinetics.The NSLPC anode delivered a high reversible capacity of 419 mAh g^(-1)and superior cycling stability(capacity retention of 96.6%at 1 A g^(-1)for 1000 cycles).Potassiumion hybrid capacitors assembled by NSLPC anode exhibited excellent cycling stability(91%capacity retention for 2000 cycles)and a high energy density of 71 Wh kg^(-1)at a power density of 92 W kg^(-1).

Stable NiPt-Mo_(2)C active site pairs enable boosted water splitting and direct methanol fuel cell

Sluggish kinetics of methanol oxidation reaction(MOR)and alkaline hydrogen evolution reaction(HER)even on precious Pt catalyst impede the large-scale commercialization of direct methanol fuel cell(DMFC)and water electrolysis technologies.Since both of MOR and alkaline HER are related to water dissociation reaction(WDR),it is reasonable to invite secondary active sites toward WDR to pair with Pt for boosted MOR and alkaline HER activity on Pt.Mo_(2)C and Ni species are therefore employed to engineer NiPt-Mo_(2)C active site pairs,which can be encapsulated in carbon cages,via an in-situ self-confinement strategy.Mass activity of Pt in NiPt-Mo_(2)C@C toward HER is boosted to11.3 A mg_(pt)^(-1),33 times higher than that of Pt/C.Similarly,MOR catalytic activity of Pt in NiPt-Mo_(2)C@C is also improved by 10.5 times and the DMFC maximum power density is hence improved by 9-fold.By considering the great stability,NiPt-Mo_(2)C@C exhibits great practical application potential in DMFCs and water electrolysers.

TRIP13基因新突变导致卵母细胞成熟阻滞为特征的女性不孕

卵母细胞成熟阻滞(oocyte maturation arrest,OMA)是指卵母细胞减数分裂过程异常而导致的卵母细胞成熟障碍的一种罕见的临床现象,也是女性原发性不孕的原因之一。这类患者临床上常表现为:反复促排卵后无法获得成熟卵子,并且未成熟卵母细胞经体外培养后仍不能成熟。迄今研究发现PATL2、TUBB8和TRIP13基因突变与OMA有关,但是有关OMA的遗传学分子因素及机制研究仍不完整。本研究通过收集临床上辅助生殖助孕过程中35名反复出现OMA的原发不孕女性患者的外周血,提取其基因组DNA进行全外显子组测序分析,对疑似致病突变进行验证及家系共分离分析,发现先证者1的TRIP13基因9号外显子存在纯合突变c.859A>G,突变导致对应编码的287位的氨基酸由异亮氨酸突变为缬氨酸(p.Ile287Val);先证者2的TRIP13基因1号外显子存在纯合突变c.77A>G,突变导致对应编码的26位的氨基酸由组氨酸突变为精氨酸(p.His26Arg);先证者3的TRIP13基因的4号和12号外显子存在复合杂合突变c.409G>A和c.1150A>G,c.409G>A突变导致对应编码的137位的氨基酸由天冬氨酸突变为天冬酰胺(p.Asp137Asn),c.1150A>G突变导致对应编码的384位的氨基酸由丝氨酸突变为甘氨酸(p.Ser384Gly),三名患者所携带的突变均引起TRIP13基因编码的TRIP13蛋白发生错义突变。其中3个突变位点在国内外尚未有文献报道。此外,通过在HeLa细胞中分别转染四个突变质粒,并进行体外免疫印记实验和细胞增殖实验,发现这些突变会造成不同程度的TRIP13蛋白表达的增加以及细胞增殖速率异常。本文总结了既往研究报道的TRIP13基因突变位点,丰富了TRIP13致病基因突变谱,为进一步研究TRIP13基因导致OMA的致病机制及临床的诊断和治疗提供了依据。

Robust Magnetism Against Pressure in Non-Superconducting Samples Prepared from Lutetium Foil and H2/N2 Gas Mixture

We report the observation of a magnetic transition at the temperature about 56 K,through the high-pressure heat capacity and magnetic susceptibility measurements on the samples that have been claimed to be a nearroom-temperature superconductor[Dasenbrock-Gammon et al.Nature 615,244(2023)].Our results show that this magnetic phase is robust against pressure up to 4.3 GPa,which covers the critical pressure of boosting the claimed superconductivity.

No evidence of superconductivity in a compressed sample prepared from lutetium foil and H_(2)/N_(2) gas mixture

A material described as lutetium–hydrogen–nitrogen(Lu-H-N in short)was recently claimed to have“near-ambient superconductivity”[Dasenbrock-Gammon et al.,Nature 615,244–250(2023)].If this result could be reproduced by other teams,it would be a major scientific breakthrough.Here,we report our results of transport and structure measurements on a material prepared using the same method as reported by Dasenbrock-Gammon et al.Our x-ray diffraction measurements indicate that the obtained sample contains three substances:the facecentered-cubic(FCC)-1 phase(Fm-3m)with lattice parameter a=5.03Å,the FCC-2 phase(Fm-3m)with a lattice parameter a=4.755Å,and Lu metal.The two FCC phases are identical to the those reported in the so-called near-ambient superconductor.However,we find from our resistance measurements in the temperature range from 300 K down to 4 K and the pressure range 0.9–3.4 GPa and our magnetic susceptibility measurements in the pressure range 0.8–3.3 GPa and the temperature range down to 100 K that the samples show no evidence of superconductivity.We also use a laser heating technique to heat a sample to 1800 XC and find no superconductivity in the produced dark blue material below 6.5 GPa.In addition,both samples remain dark blue in color in the pressure range investigated.

Innovations in metallurgical and materials processes:advancing liquid theory and honoring Prof.Han-jie Guo's contributions to physical chemistry in metallurgy

Spanning three decades,Prof.Han-jie Guo's research group has dedicated itself to exploring the fundamental theories and practical applications of physical chemistry within the realm of metallurgy.Operating under the assumption that molecular entities and complexes persist in liquid states,the team has unearthed pivotal insights.

膝骨关节炎MSCT、MRI的影像学特征及联合应用的诊断价值

目的探讨膝骨关节炎多层螺旋计算机断层扫描(MSCT)、磁共振成像(MRI)的影像学特征,分析两者联合诊断的效能。方法回顾性分析2017年1月—2018年3月北京市和平里医院接收的疑似膝骨关节炎受检者78例的临床资料,分别实施MSCT、MRI检查。所有受试者行关节镜检查明确膝骨关节炎的发生情况,将其作为"金标准"。总结MSCT、MRI的影像学表现,绘制受试者工作特征(ROC)曲线,分析不同方法的诊断效能。结果全组受试者中共有102膝确诊为膝骨关节炎,MSCT、MRI诊断该病均有典型的特征;MSCT、MRI、两者联合诊断膝骨关节炎的敏感性分别为86.27%(95%CI:0.786,0.897)、95.10%(95%CI:0.824,0.959)、98.04%(95%CI:0.855,0.987);特异性分别为77.78%(95%CI:0.712,0.798)、90.74%(95%CI:0.866,0.913)、98.15%(95%CI:0.890,0.985);准确性分别为83.33%、93.89%、98.08%;AUC分别为0.712(95%CI:0.502,0.851)、0.806(95%CI:0.671,0.855)、0.913(95%CI:0.782,0.974)(P<0.05)。联合诊断的敏感性、特异性、准确性和AUC均高于单独诊断。结论MSCT、MRI诊断膝骨关节炎有典型的影像学特征,且两者联合诊断的效能更佳。