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.

Absence of BCS–BEC crossover in FeSe_(0.45)Te_(0.55) superconductor

In iron-based superconductor Fe(Se,Te), a flat band-like feature near the Fermi level was observed around the Brillouin zone center in the superconducting state. It is under debate whether this is the evidence on the presence of the BCS–BEC[Bardeen–Cooper–Schrieffer(BCS), Bose–Einstein condensation(BEC)] crossover in the superconductor. High-resolution laser-based angle-resolved photoemission measurements are carried out on high quality single crystals of FeSe_(0.45)Te_(0.55) superconductor to address the issue. By employing different polarization geometries, we have resolved and isolated the dyz band and the topological surface band, making it possible to study their superconducting behaviors separately. The dyz band alone does not form a flat band-like feature in the superconducting state and the measured dispersion can be well described by the BCS picture. We find that the flat band-like feature is formed from the combination of the dyz band and the topological surface state band in the superconducting state. These results reveal the origin of the flat band-like feature and rule out the presence of BCS-BEC crossover in Fe(Se,Te) superconductor.

Astragalus membranaceus(Fisch.)Bge.administered by dissolving microneedles achieves systemic therapeutic effects at low doses Author links open overlay panel

Objective:To determine the main components of Astragalus membranaceus(Fisch.)Bge(A.membranaceus,Huang Qi),Astragaloside IV(AIV)and Astragalus polysaccharides(AP),to characterize their properties,evaluate their in vivo efficacy,and to analyze drug diffusion using dissolving microneedle(DMN)technology in vivo.Methods: Respectively,AIV-and AP-loaded DMNs comprising chitosan(CTS)and polyvinyl alcohol(PVA)were prepared via dual-mold forming.Their morphology,mechanical properties,in vivo solubility,and skin irritation characteristics were tested.In vivo efficacy was assessed in cyclophosphamide-induced immunosuppressed mice,in vivo diffusion of AIV and AP by DMNs and conventional methods was compared,and the rheological properties of AIV-CTS-PVA and AP-CTS-PVA mixtures were measured.Results: Subcutaneous dissolution and absorption of AIV-CTS-PVA and AP-CTS-PVA microneedles(MNs)at low doses(50%–17%of intraperitoneal AIV injection and 12%–4%of intravenous AP injection)reduced the spleen index and acid phosphatase activity in immunosuppressed mouse models,increased the thymus index,and achieved equivalent or better systemic therapeutic effects.Compared with injections,AIV and AP achieved controllable solid-liquid conversion through delivery with CTS-PVA MNs,resulting in highly localized aggregation within 48 h,reducing the initial explosive effect of the drug,and achieving stable and slow drug release.Conclusion: The present study enhances our understanding of the efficacy and remote effects of drug-loaded DMNs from a traditional Chinese medicine(TCM)perspective,thereby promoting the development of precise and efficient delivery of TCM and further expanding the drug-loading range and application scenarios for DMNs.

Negligible normal fluid in superconducting state of heavily overdoped Bi_(2)Sr_(2)CaCu_(2)O_(8+δ) detected by ultra-low temperature angle-resolved photoemission spectroscopy

In high temperature cuprate superconductors,it was found that the superfluid density decreases with the increase of hole doping.One natural question is whether there exists normal fluid in the superconducting state in the overdoped region.In this paper,we have carried out high-resolution ultra-low temperature laser-based angle-resolved photoemission measurements on a heavily overdoped Bi2212 sample with a T_(c) of 48 K.We find that this heavily overdoped Bi2212 remains in the strong coupling regime with 2Δ_(0)/(k_(B)T_(c))=5.8.The single-particle scattering rate is very small along the nodal direction(~5 meV) and increases as the momentum moves from the nodal to the antinodal regions.A hard superconducting gap opening is observed near the antinodal region with the spectral weight at the Fermi level fully suppressed to zero.The normal fluid is found to be negligibly small in the superconducting state of this heavily overdoped Bi2212.These results provide key information to understand the high T_(c) mechanism in the cuprate superconductors.

2019年度国家自然科学基金临床肿瘤研究方向分析及思考

随着细胞生物学等学科的不断发展和深入,肿瘤学基础研究取得了一定进展,肿瘤学科申请项目数量及质量也逐渐提高。本文总结2019年度国家自然科学基金临床肿瘤学科面上项目、青年科学基金项目以及地区科学基金项目的申请与资助情况,并从不同角度深入分析面上项目的研究方向,针对临床肿瘤中非编码RNA、肿瘤免疫治疗、肿瘤微环境、肿瘤代谢等代表性研究方向,以及淋巴管新生、细胞焦亡及铁死亡、溶酶体及线粒体等研究前沿进行综述。

反蛋白石结构的g-C_(3)N_(4)可控合成及其优异的光催化产氢性能

日渐严重的能源短缺和环境失衡问题已经阻碍了人类社会的进一步和长远可持续发展。能够将太阳能转化为可储存化学能的半导体基光催化技术被广泛的理解为一种经济和清洁的解决方式,比如光催化分解水。虽然被认为是有前途的光催化剂,g-C_(3)N_(4)低的比表面积极大地限制了其光催化性能。大孔-介孔结构可以为物质的传输和光的充分利用提供有效通道,从而提高光催化反应效率。本文中,具有反蛋白石(IO)结构的g-C_(3)N_(4)合理地通过紧密堆积的SiO_(2)作为模板来制备得到。并且显示出超高比表面积(450.2 m~2·g^(-1)),表现出更好的光催化产氢速率(21.22μmol·h^(-1)),约为体相g-C_(3)N_(4) (3.65μmol·h^(-1))的六倍。相对于体相g-C_(3)N_(4),IO g-C_(3)N_(4)表现了更好的可见光吸收能力,这得益于3D多孔结构的多重光散射效应。同时,较低的荧光强度、更长的荧光寿命、更小的Nyquist半圆环和更强的光电流响应协同地抑制了光生载流子的复合,降低了界面电荷传输的电阻,促进了光生电子的形成。此外,氮空位的存在能够增强局部电子密度,氮气吸-脱附测试揭示了IO g-C_(3)N_(4)中存在丰富的中孔和大孔,高比表面积暴露更多的活性边界和催化中心。正如光学性质、电子顺磁共振和电化学表征结果所揭示的那样,那些有利因素,包括增强的光利用率、提高的光生电荷的分离、延长的荧光寿命都赋予具有反蛋白石结构的IO g-C_(3)N_(4)优越的光催化性能。这项工作为结构设计和光催化性能调制做出了重要贡献。

Migration routes,population status and important sites used by the globally threatened Black-faced Spoonbill(Platalea minor):a synthesis of surveys and tracking studies

Background:The Black-faced Spoonbill(Platalea minor)is a globally threatened species,nesting mainly in western Korea with smaller numbers breeding in Liaoning Province,China,and Far East Russia.Recent winter field surveys to estimate the species'population size were almost totally conducted in coastal areas,but tracking studies showed that some individuals now winter inland.To ensure its long-term survival,we need a more comprehensive assessment of the current distribution and abundance of the species.Methods:We combined the most recent count data and satellite tracking information to update existing informa-tion about the population abundance and distribution of the Black-faced Spoonbill at all stages of its annual life cycle,and how these have changed during 2004-2020.Results:Black-faced Spoonbills mainly breed on the west coast of the Korean peninsula,while immature birds show a wider summer distribution throughout Yellow Sea coastal areas,when a few remain on wintering sites in the south.Combined tracking results and mid-winter counts confirmed known wintering sites on the east and south coasts of China,but showed that the species also winters on wetlands in the Yangtze River floodplain and in Southeast Asia.During 2004-2020,counts of wintering birds in coastal habitats increased from 1198 to 4864,with numbers wintering on the island of Taiwan contributing most to the overall increase.Latest counts found 5222 in 2021.We also identify key wintering and stopover sites as well as their current conservation status.Conclusions:This study revised the known summering and wintering ranges of the Black-faced Spoonbill and assessed the conservation status of key sites based on a combination of field survey and satellite tracking data.We recommend prioritisation of further field research to identify and survey inland wintering areas in the Yangtze River floodplain and summering areas of immature birds.More tracking of adult individuals and birds during spring migration is necessary to fill these information gaps.We also suggest establishing a Black-faced Spoonbill monitoring platform to store,share and show real-time distribution range and population abundance data.

Migration routes,behavior and protection status of Eurasian Spoonbills(Platalea leucorodia)wintering in China

Background:The Eurasian Spoonbill(Platalea leucorodia)occurs throughout Eurasia and North and sub-Saharan Africa,with three recognized subspecies and six geographically distributed populations.However,in China,we knew almost nothing about migration routes,habitat use and effectiveness of current site protection measures for this species.Methods:We deployed Global Positioning System/Global System for Mobile Communications(GPS/GSM)satellite trackers on 29 Eurasian Spoonbills captured in summer in Mongolia and northeastern China,to obtain complete migration routes data from 10 individuals from 19 complete migration episodes.Results:Tracking data showed no geographical overlap during the annual cycle in Eurasian Spoonbills marked in the two main summering areas.Birds marked in the Naoli River Basin in Heilongjiang Province,China,wintered along the Jiangsu coastline in China,while Eurasian Spoonbills from two discrete summering areas(in Inner and western Mon-golia)overwintered inland in the Yangtze River floodplain of China.Excluding the single Inner Mongolian bird,spring migration was significantly faster than autumn migration in the other two groups of birds.Eurasian Spoonbills mainly used water,wetland and grassland habitats in summer,but almost exclusively water in winter.Lack of protection of staging sites used by all the birds in spring and poor levels of protection throughout the annual cycle for western Mongolian birds(5-22%)gives considerable cause for concern,although sites used in other time by East Mongolian and Naoli River birds in the rest of their annual life cycle enjoyed good levels of protection(49-95%).Conclusions:These results revealed previously unknown relationships between summering and wintering areas,migration routes and stopover sites for Eurasian Spoonbills wintering in China,suggesting the existence of discrete biogeographical population units.They also identified winter habitat use of Eurasian Spoonbills in China,confirming open water habitats as being critical throughout the annual cycle,although based on small sample size,gaps in cur-rent site safeguard networks for these populations.

皮肤微生态和益生菌抗光老化研究进展

皮肤微生态是构成皮肤屏障的重要组成部分,其皮肤微生物的正常代谢活动能抵御外界刺激,因此维持皮肤微生物稳态是化妆品领域的重点研究对象。系统介绍了紫外线与皮肤及其微生物的关系,并表明长期暴露于紫外线辐射会扰乱皮肤微生物稳态从而导致光损伤、老化等问题。综述了国内外抗光老化研究进展,证实了皮肤微生物、益生菌等可以阻挡或逆转紫外线的负面影响,恢复皮肤稳态。旨在对开发微生物抗光老化方法提供理论支持和研究思路,以期推动中国化妆品的健康可持续发展。

Construction of human Fab library and screening of a single-domain antibody of amyloid-beta 42 oligomers

Screening humanized antibodies from a human Fab phage display library is an effective and quick method to obtain beta-amyloid oligomers. Thus, the present study prepared amyloid-beta 42 oli- gomers and constructed a have human Fab phage display library based on blood samples from six healthy people. After three rounds of biopanning in vitro, a human single-domain antibody that spe- cifically recognized amyloid-beta 42 oligomers was identified. Western blot and enzyme-linked im- munosorbent assay demonstrated this antibody bound specifically to human amyloid-beta 42 tetramer and nonamer, but not the monomer or high molecular weight oligomers. This study suc- cessfully constructed a human phage display library and screened a single-domain antibody that specifically recognized amyloid-beta 42 oligomers.

Intrinsic electronic structure and nodeless superconducting gap of YBa_(2)Cu_(3)O_(7)-σ observed by spatially-resolved laser-based angle resolved photoemission spectroscopy

The spatially-resolved laser-based high-resolution angle resolved photoemission spectroscopy(ARPES) measurements have been performed on the optimally-doped YBa_(2)Cu_(3)O_(7)-σ(Y123) superconductor. For the first time, we found the region from the cleaved surface that reveals clear bulk electronic properties. The intrinsic Fermi surface and band structures of Y123 were observed. The Fermi surface-dependent and momentum-dependent superconducting gap was determined which is nodeless and consistent with the d+is gap form.

Conservation of the particle–hole symmetry in the pseudogap state in optimally-doped Bi_(2)Sr_(2)CuO_(6+δ) superconductor

The pseudogap state is one of the most enigmatic characteristics in the anomalous normal state properties of the high temperature cuprate superconductors. A central issue is to reveal whether there is a symmetry breaking and which symmetries are broken across the pseudogap transition. By performing high resolution laser-based angle-resolved photoemission measurements on the optimally-doped Bi_(2)Sr_(1.6)La_(0.4)CuO_(6+δ) superconductor, we report the observations of the particle-hole symmetry conservation in both the superconducting state and the pseudogap state along the entire Fermi surface. These results provide key insights in understanding the nature of the pseudogap and its relation with high temperature superconductivity.

Expressions of CCR7 and CXCR4 Are Associated with Differentiation in Gastrointestinal Cancer

Purpose: The chemokine receptors CCR7 and CXCR4 have been shown to play an important role in cancer invasion and metastasis. This study was aimed to investigate CCR7 and CXCR4 expressions and evaluate the association between their expressions and the clinicopathological features in gastrointestinal cancer. Method: 27 paired tissue samples from patients who had curative surgery for gastrointestinal cancer were obtained. Quantitative real-time PCR, immunochemistry assay and western blot analysis were carried out to investigate the expressions of CCR7, CXCR4 expressions in gastrointestinal cancer. Results: The cancer tissues expressed significant higher level of CCR7 (P = 0.000) and CXCR4 (P = 0.000) protein than the adjacent normal mucosa. Expressions of CCR7 (P = 0.002) and CXCR4 (P = 0.003) protein in cancer tissues exhibited significant correlation with differentiation in gastrointestinal cancer. Conclusion: Expressions of CCR7 and CXCR4 protein were associated with differentiation in gastrointestinal cancer. CCR7 and CXCR4 may be predictive factors for poor prognosis in patients with gastrointestinal cancer.

Using Machine Learning to Identify and Optimize Sensitive Parameters in Urban Flood Model Considering Subsurface Characteristics

This study presents a novel method for optimizing parameters in urban flood models,aiming to address the tedious and complex issues associated with parameter optimization.First,a coupled one-dimensional pipe network runoff model and a two-dimensional surface runoff model were integrated to construct an interpretable urban flood model.Next,a principle for dividing urban hydrological response units was introduced,incorporating surface attribute features.The K-means algorithm was used to explore the clustering patterns of the uncertain parameters in the model,and an artificial neural network(ANN)was employed to identify the sensitive parameters.Finally,a genetic algorithm(GA) was used to calibrate the parameter thresholds of the sub-catchment units in different urban land-use zones within the flood model.The results demonstrate that the parameter optimization method based on K-means-ANN-GA achieved an average Nash-Sutcliffe efficiency coefficient(NSE) of 0.81.Compared to the ANN-GA and K-means-deep neural networks(DNN) methods,the proposed method better characterizes the runoff generation and flow processes.This study demonstrates the significant potential of combining machine learning techniques with physical knowledge in parameter optimization research for flood models.

Computed tomography-based delta radiomics of tumor core_edge combination for systemic treatment response evaluation in pancreatic cancer

Background:As a systemic disease,pancreatic cancer(PC)can be treated systemically to raise the R0 resection rate and enhance patient prognosis.The best ways to assess the treatment response to systemic treatment of patients with PC are still lacking.Methods:A total of 122 PC patients were enrolled;25 of these patients were used as an independent testing set.According to the pathologic response,PC patients were classified into the responder and nonresponder groups.The whole tumor,core,edge,and peritumoral were segmented from the enhanced computed tomography(CT)images.Machine-learning models were created by extracting the variations in radionics features before and after therapy(delta radiomics features).Finally,we compared the performance of models based on radiomics features,changes in tumor markers,and radiologic evaluation.Results:The model based on the core(area under curve[AUC]=0.864)and edge features(AUC=0.853)showed better performance than that based on the whole tumor(AUC=0.847)or peritumoral area(AUC=0.846).Moreover,the tumor core_edge combination model(AUC=0.899)could better increase confidence in treatment response than using either of them alone.The accuracies of models based on changes in tumor markers and radiologic evaluation were relatively poorer than of the radiomics model.Moreover,Patients predicted to respond to therapy using the radiomics model showed a relatively longer overall survival(43 vs 27 months),although there were no significant differences(P=.063).Conclusions:The tumor core_edge combination delta radiomics model is an effective approach to evaluate pathologic response in PC patients with systemic treatment.

The effects of overexpressing UDP-Glycosyltransferases genes on the plant response to abiotic stress:a meta-analysis

Uridine diphosphate(UDP)-Glycosyltransferases(UGT)play essential roles in modifying secondary metabolites during the plant life cycle and are also involved in the response to abiotic stresses.However,the plant UGT family is vast and the available data describing their role in abiotic stress responses is varied and intricate,so that their potential roles are often obscured.To address this,a meta-analysis was conducted to assess the effects of overexpression of UGT on various plant physiological indicators under abiotic stress.Out of the 15 plant characteristics examined in UGT overexpressing plants,10 showed an increase of over 30%,while two plant characteristics decreased by more than 30%,while only three indices were significantly affected under non-stressed conditions.Notably,UGT had a significant and positive effect in salt-stressed plants.This study sheds light on the complex role of UGT in abiotic stress and can provide valuable guidance for future research on UGT functions and their genetic manipulation in crop breeding programs for improved abiotic stress tolerances.

Global burden of HIV-negative multidrug-and extensively drug-resistant tuberculosis based on Global Burden of Disease Study 2021

Background:Tuberculosis(TB),caused by Mycobacterium tuberculosis,remains the second leading cause of death from a single infectious disease globally and poses a significant economic and clinical burden in the world in 2022.Of particular concern is the emergence of drug-resistant TB,accounting for 15%-20%of TB deaths.It is imperative to delve into the global trends of incidence and death rate for multidrug-resistant tuberculosis(MDRTB)and extensively drug-resistant tuberculosis(XDR-TB),drawing upon the comprehensive Global Burden of Disease(GBD)2021 drug-resistant tuberculosis dataset.Methods:From the GBD 2021,data on incidence,prevalence,disability-adjusted life years(DALYs),and death of MDR-TB and XDR-TB from 1990 to 2021 were collected.We calculated the estimated annual percentage changes in age standardized incidence rate(ASIR)and age-standardized death rate(ASDR),segmented by age,sex,and socio-demographic index(SDI).The impacts of various risk factors on MDR-TB and XDR-TB were also analyzed.Results:In 2021,there were an estimated 443,680(95%uncertainty interval[UI]:259,196-766,545)incident cases of MDR-TB,and an estimated 106,818(95%UI:41,612-211,854)death cases of MDR-TB,while there were an estimated 24,036(95%UI:17,144-34,587)incident cases of XDR-TB and 7,946(95%UI:3,326-14,859)death cases of XDR-TB.The incidence and death cases of MDR-TB were lowest in high SDI regions,whereas the incidence rates of XDR-TB in high-middle SDI regions were higher than those in middle SDI and high SDI regions.Conclusion:This study reported the disease burden of drug-resistant TB from 1990 to 2021.Until 2021,drugresistant TB is still a serious problem in low SDI countries,especially for high-risk age populations with highrisk factors.Controlling drug-resistant TB requires effective control strategies and healthcare systems.

Germplasm resources and secondary metabolism regulation in Reishi mushroom(Ganoderma lucidum)

Ganoderma lucidum is a valuable medical macrofungus with a myriad of diverse secondary metabolites,in which triterpenoids are the major constituents.This paper introduced the germplasm resources of genus Ganoderma from textual research,its distribution and identification at the molecular level.Also we overviewed G.lucidum in the components,the biological activities and biosynthetic pathways of ganoderic acid,aiming to provide scientific evidence for the development and utilization of G.lucidum germplasm resources and the biosynthesis of ganoderic acid.

通过5-氨基-4-甲酰基咪唑盐酸盐提高可印刷介观钙钛矿太阳能电池的光伏性能

基于m-TiO_(2)/m-ZrO_(2)/C的无空穴可印刷介观钙钛矿太阳能电池(p-MPSCs)具有成本低廉、操作简便和稳定性优异的特点,被认为是最具商业应用潜力的新型光伏器件之一.然而,与传统PSC相比,p-MPSCs的开路电压(VOC)损失较大,导致能量转换效率(PCE)与传统PSC存在差距.在此,我们提出了一种利用5-氨基-4甲酰胺咪唑盐酸盐(AICA)提升p-MPSCs开路电压的方法.AICA不仅可以调节钙钛矿膜的功函数,其酰胺基团和氨基还能分别钝化钙钛矿中未配位的Pb2+和I−缺陷,稳定钙钛矿的结构,形成高质量钙钛矿薄膜,从而抑制缺陷诱导的非辐射复合.因此,引入AICA后p-MPSCs获得了16.68%的PCE,并且VOC从0.88提升至0.98 V.

Phase equilibria of long-period stacking ordered phase in the ternary Mg-Y-Al alloys

Phase equilibria focusing on the long-period stacking ordered(LPSO)phases have been experimentally in-vestigated in the Mg-Y-Al alloys.The microstructures of the eleven representative alloys annealed at 450,500 and 550°C were systematically investigated using X-ray diffraction(XRD),scanning electron mi-croscopy(SEM)and transmission electron microscopy(TEM).Two thermodynamically stable LPSO poly-types were identified,including 18R and 10H structures.Meanwhile,the transformation of 18R→10H was detected in Mg-9.0Y-1.7Al(at.%)alloy,while the coexistence of 18R and 10H was observed in Mg-14.2Y-12.8Al(at.%)alloy.It was found that the LPSO phases were non-stoichiometric compounds with ternary solubilities.The 18R can dissolve up to 7.21 at.%-8.37 at.%Al and 10.75 at.%-12.01 at.%Y,while the 10H can dissolve up to 9.35 at.%-10.37 at.%Al and 14.50 at.%-14.94 at.%Y.All of the experimental re-sults were used to construct the isothermal sections,which is conducive to the design of Mg-Y-Al alloys.