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One-step hydrothermal synthesis of Cit-NaYbF_(4):Er^(3+)nanocrystals with enhanced red upconversion emission for in vivo fluorescence molecular tomography

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Journal of Rare Earths 2024年第1期42卷 36-45,I0002页

作者： Xiaoli Luo Qichen Chen Hongbo Guo Heng Zhang Xiaowei He wu Zhao School of mathematics and Computer Science Ningxia Normal UniversityGuyuan756099China School of Information Science and Technology Northwest UniversityXi'an710127China

Fluorescence imaging techniques represent essential tools in in vitro,preclinical,and clinical *** this study,an improved one-step hydrothermal method to synthesize citric acid(CA)modifiedα-NaYbF_(4):2.Er^(3+)nanocrystals was *** introduction of various doping ions into NaYbF_(4):2.Er^(3+)and the different valence states of the same ions affect both the crystal size and upconversion luminesce *** fore,we investigated the upconversion luminesce nce enha ncement of NaYbF_(4):2.Er^(3+)by ion doping and find that the upconversion luminescence intensity of the upconversion nanoparticles(UCNPs)co-doped with 5 mol%Fe^(2.)ions shows the greatest enhancement,especially for red emission at654 ***,HeLa cells incubated with UCNPs allow for imaging with strong red upconversion emission detectio *** laser scanning microscope(CLSM)fluorescent images of HeLa cells indicate that NaYbF_(4):2.Er/5%Fe^(2.)leads to a clear outline and improves visualization of the cell *** addition,the CA coated NaYbF_(4):2.Er^(3+)/5%Fe^(2.)nanoparticles and NaYbF_(4):2.Er^(3+)/5%Fe^(2.)show low cytotoxicity in HeLa *** imaging reveals the efficiency of these UCNPs to analyze the lungs,liver,and ***,these results indicate that the Cit-NaYbF_(4):2.Er^(3+)/5%Fe^(2.)UCNPs are efficient nanoprobes for fluorescence molecular to mography.

关键词： Hydrothermal method Fe^(2.)ion doping Tuning size Nanoprobes Fluorescence imaging Rare earths

Estimates for eigenvalues of Laplacian operator with any order

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Science china mathematics 2007年第8期50卷 1078-1086页

作者： Fa-en wu~(1+) Lin-fen CAO~2.1 department of {2.,Beijing Jiaotong University,Beijing 100044,china 2.department of {2.,Henan normal University,Xinxiang 453007,china department of mathematics Beijing Jiaotong University Beijing China department of mathematics Henan Normal University Xinxiang China

Let D be a bounded domain in an n-dimensional Euclidean space Rn.Assume that 01≤λ2.…≤λk≤…are the eigenvalues of the Dirichlet Laplacian operator with any order l: （-△）lu=λu,in D u=■=…=■=0,on■■D. Then ... 详细信息

Let D be a bounded domain in an n-dimensional Euclidean space Rn.Assume that 01≤λ2./sub>≤…≤λk≤…are the eigenvalues of the Dirichlet Laplacian operator with any order l: （-△）lu=λu,in D u=■=…=■=0,on■■D. Then we obtain an upper bound of the（k+1）-th eigenvalueλk+1in terms of the first k eigenvalues. sum from i=1 to k(λk+1-λi)≤（1/n）[4l（n+2.-2.]1/2./sup>{sum from i=1 to k(λk+1-λi)1/2./sup>λil-1/lsum from i=1 to k(λk+1-λi)1/2./sup>λi1/l}1/2./sup>. This ineguaiity is independent of the domain ***,for any l≥3 the above inequality is better than all the known *** rusults are the natural generalization of inequalities corre- sponding to the case l=2.considered by Qing-Ming Cheng and Hong-Cang *** l=1,our inequalities imply a weaker form of Yang *** aslo reprove an implication claimed by Cheng and Yang.

关键词： Dirichlet problem eigenvalue estimate Laplacian operator

Bioinspired zinc-mediated umpolung thiolation of alkyl electrophiles: reaction development, scope and mechanism

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Science china Chemistry 2024年第3期67卷 898-907页

作者： Yuenian Xu Yan Zhang Yong Liu Wen-wu Sun Jie Huang Hui He Yingjie wu Wen Liu Shao-Fei Ni Xu-Qiong Xiao Xinxin Shao College of Material Chemistry and Chemical EngineeringKey Laboratory of Organosilicon Chemistry and Material Technology of Ministry of EducationHangzhou Normal UniversityHangzhou 311121China School of Pharmaceutical Sciences South-Central Minzu UniversityWuhan 430074China department of Chemistry and Key Laboratory for Preparation and Application of Ordered Structural Materials of Guang-dong Province Shantou UniversityShantou 515063China

Zinc-promoted umpolung thiolation of alkyl electrophiles with masked sulfur transfer reagents in the absence of nickel or copper catalysis is described. This protocol proceeds via a SET process of Zn to electrophilic sulfur reagent followed by insertion of Zn into disulfide and nucleophilic thiolation, providing straightforward access to a wide range of alkyl sulfides with broad substrate scope. A neutral TMEDA-ligated four-coordinated zinc thiolate with tetrahedra geometry was synthesized, isolated and fully characterized by NMR, IR and X-ray analysis. More importantly, the chemical reactivity of this active intermediate has been investigated, enabling the construction of C-Se, C-Te, Sb-S and Bi-S bonds to prepare valuable sulfur-containing molecules and beyond.

关键词： umpolung thiolation C(sp^(3))-S bond formation masked sulfur reagents reductive coupling

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Added value of ratio of cross diameters of the appendix in ultrasound diagnosis of acute appendicitis

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World Journal of Gastrointestinal Surgery 2024年第1期16卷 21-28页

作者： Feng-Wa Gu Si-Ze wu department of Ultrasound The First Affiliated Hospital of Hainan Medical UniversityHaikou 570102Hainan ProvinceChina

BACKGROUND The maximum outer diameter(MOD)of the appendix is an essential parameter for diagnosing acute appendicitis,but there is space for improvement in ultrasound(US)diagnostic *** To investigate whether combining the ratio of the cross diameters(RATIO)of the appendix with MOD of the appendix can enhance the diagnostic performance of acute *** A retrospective study was conducted,and medical records of 2.3 patients with acute appendicitis and 112.patients with a normal appendix were *** MOD and RATIO of the appendix were calculated and tested for their diagnostic performance of acute appendicitis,both individually and in *** The RATIO for a normal appendix was 1.32.0.16,while for acute appendicitis it was 1.09±*** cut-off value for RATIO was determined to be≤*** area under the receiver operating characteristic curve(AUC)for diagnosing acute appendicitis using RATIO≤1.18 and MOD>6 mm was 0.870 and 0.652.*** was a significant difference in AUC between RATIO≤1.18 and MOD>6 mm(P6 mm with MOD>6 mm alone,the combination showed increased specificity,positive predictive value(PPV),and ***,the sensitivity and negative predictive value *** Combining RATIO of the appendix≤1.18 and MOD>6 mm can significantly improve the specificity,PPV,and AUC in the US diagnosis of acute appendicitis.

关键词： Acute appendicitis Diameter Ratio Diagnosis Ultrasound

Personalized Lower Limb Gait Reconstruction Modeling Based on RFA-ProMP

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Computers, Materials & Continua 2024年第7期80卷 1441-1456页

作者： Chunhong Zeng Kang Lu Zhiqin He Qinmu wu College of Electrical Engineering Guizhou UniversityGuiyang550025China

Personalized gait curves are generated to enhance patient adaptability to gait trajectories used for passive training in the early stage of rehabilitation for hemiplegic *** article utilizes the random forest algorithm to construct a gait parameter model,which maps the relationship between parameters such as height,weight,age,gender,and gait speed,achieving prediction of key points on the gait *** enhance prediction accuracy,an attention mechanism is introduced into the algorithm to focus more on the main ***,to ensure high similarity between the reconstructed gait curve and the normal one,probabilistic motion primitives(ProMP)are used to learn the probability distribution of normal gait data and construct a gait ***,using the specified step speed as input,select a reference gait trajectory from the learned trajectory,and reconstruct the curve of the reference trajectoryusing the gait keypoints predictedby the parametermodel toobtain the final *** results demonstrate that the method proposed in this paper achieves 98%and 96%curve correlations when generating personalized lower limb gait curves for different patients,respectively,indicating its suitability for such tasks.

关键词： Personalized lower limb gait prediction random forest probabilistic movement primitives

Projected changes in Köppen-Trewartha climate zones under 1.5-4℃global warming targets over mid-high latitudes of Northern Asia using an ensemble of RegCM4 simulations

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Advances in Climate Change Research 2024年第2期15卷 185-196页

作者： Jie wu Xue-Jie GAO Xian-Bing TANG Filippo GIORGI School of Geography and Environmental Engineering Gannan Normal UniversityGanzhou 341000China Climate Change Research Center Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science&TechnologyNanjing 210044China University of Chinese Academy of Sciences Beijing 100049China The Abdus Salam International Centre for Theoretical Physics Trieste 34100Italy

Mid-high latitude Northern Asia is one of the most vulnerable and sensitive areas to global warming,but relatively less studied *** used an ensemble of a regional climate model(RegCM4)projections to assess future changes in surface air temperature,precipitation and Köppen-Trewartha(K-T)climate types in Northern Asia under the 1.5-4℃global warming ***4 is driven by five CMIP5 global models over an East Asia domain at a grid spacing of 2. *** of the present day(1986-2.05)simulations shows that the ensembles of RegCM4(ensR)and driving GCMs(ensG)reproduce the major characters of the observed temperature,precipitation and K-T climate zones reasonably *** and more realistic spatial detail is found in RegCM4 compared to the driving GCMs.A general warming and overall increases in precipitation are projected over the region,with these changes being more pronounced at higher warming *** projected warming by ensR shows different spatial patterns,and is in general lower,compared to ensG in most months of the year,while the percentage increases of precipitation are maximum during the cold *** future changes in K-T climate zones are characterized by a substantial expansion of Dc(temperature oceanic)and retreat of Ec(sub-arctic continental)over the region,reaching∼2.%under the 4℃warming *** most notable change in climate types in ensR is found over Japan(∼60%),followed by Southern Siberia,Mongolia,and the Korean Peninsula(∼40%).The largest change in the K-T climate types is found when increasing from 2.to 3℃.The results will help to better assess the impacts of climate change and in implementation of appropriate adaptation measures over the region.

关键词： Mid-high latitudes of Northern Asia Köppen climate zones Global warming targets Regional climate model

SO_(2.-Insertion induced enantioselective oxysulfonylation to access β-chiral sulfones with quaternary carbon stereocenters

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Science china Chemistry 2024年第3期67卷 908-913页

作者： Jun Zhang Xuefeng Wang Peiqi Wang Jiayuan Fang Shaoyu Li Jie wu School of Pharmaceutical and Chemical Engineering&Institute for Advanced Studies Taizhou UniversityShanghai 200438China department of Chemistry Fudan UniversityShanghai 200438China State Key Laboratory of Organometallic Chemistry Shanghai Institute of Organic ChemistryChinese Academy of SciencesShanghai 200032China School of Chemistry and Chemical Engineering Henan Normal UniversityXinxiang 453007China

β-Chiral sulfones are structural motifs widely found in natural products and bioactive molecules, while also serving as important intermediates for the synthesis of valuable chiral scaffolds. In contrast to the rapid growth of sulfur dioxide insertion chemistry over the last decade, enantioselective catalytic variants for accessing β-chiral sulfones, especially those bearing a quaternary carbon stereocenter, remain rare. Herein, we report an enantioselective copper/bisoxazoline catalyzed oxysulfonylation of alkenes to yield isoxazolinyl-containing β-chiral sulfones bearing quaternary carbon stereocenters with moderate to excellent yields and up to 96:4 er. The advantage and irreplaceability of this sulfur dioxide insertion catalytic system have been demonstrated by achieving transformations clearly unavailable with the previously reported sulfonyl chloride system. Additionally,the recoverability of the new-developed bisoxazoline ligand L9 and its reusability without any erosion of the catalytic activity and enantioselectivity further demonstrate the usefulness of the protocol.

关键词： β-chiral sulfones sulfur dioxide insertion oxysulfonylation copper catalysis enantioselectivity

The role of proteasomes in tumorigenesis

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Genes & Diseases 2024年第4期11卷 155-169页

作者： Xiangyi Zhou Ruqing Xu Yue wu Li Zhou Tingxiu Xiang department of Oncology The First Affliated Hospital of Chongqing Medical UniversityChongqing 400016China Chongqing Key Laboratory of Translational Research for Cancer Metastasis and Individualized Treatment Chongqing University Cancer HospitalChongqing 400030China

Protein homeostasis is the basis of normal life activities,and the proteasomefamily plays an extremely important function in this *** proteasome 2.s is a concentric circle structure with twoαrings and twoβrings *** proteasome 2.s can perform both ATP-dependent and non-ATP-dependent ubiquitination proteasome degradation by binding to various subunits(such as 19S,11S,and 2.0 PA),which is performed by its active subunitβ1,β2.andβ*** proteasome can degrade misfolded,excess proteins tomaintain *** the same time,it can be utilized by tumors to degrade over-proliferate and unwanted proteins to support their *** can affect the development of tumors from several aspects including tumor signaling pathways such as NF-kB and p53,cell cycle,immune regulation,and drug ***-encoding genes have been found to be overexpressed in a variety of tumors,providing a potential novel target for cancer *** addition,proteasome inhibitors such as bortezomib,carfilzomib,and ixazomib have been put into clinical application as the first-line treatment of multiple *** and more studies have shown that it also has different therapeutic effects in other tumors such as hepatocellular carcinoma,non-small cell lung cancer,glioblastoma,and ***,proteasome inhibitors are not much effective due to their tolerance and singleness in other ***,further studies on their mechanisms of action and drug interactions are needed to investigate their therapeutic potential.

关键词： Bortezomib Cancer therapy Immunoproteasome Multiplemyeloma Proteasome 2.S Proteasome inhibitor Thymoproteasom

Impact crater recognition methods:A review

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Science china Earth Sciences 2024年第6期67卷 1719-1742页

作者： Dong CHEN Fan HU Liqiang ZHANG Yunzhao wu Jianli DU Jiju PEETHAMBARAN College of Civil Engineering Nanjing Forestry UniversityNanjing 210037China department of Geography State Key Laboratory of Remote Sensing ScienceFaculty of Geographical ScienceBeijing Normal UniversityBeijing 100875China Purple Mountain Observatory Chinese Academy of SciencesNanjing 210023China Key Laboratory of Space Object and Debris Observation Chinese Academy of SciencesNanjing 210023China department of mathematics and Computing Science Saint Mary’s UniversityHalifaxNS B3H 3C3Canada

Impact craters are formed due to the high-speed collisions between small to medium-sized celestial *** is the most significant driving force in the evolution of celestial bodies,and the impact craters provide crucial insights into the formation,evolution,and impact history of celestial *** this paper,we present a detailed review of the characteristics of impact craters,impact crater remote sensing data,recognition algorithms,and applications related to impact *** first provide a detailed description of the geometric texture,illumination,and morphology characteristics observed in remote sensing data of *** we summarize the remote sensing data and cataloging databases for the four terrestrial planets(i.e.,the Moon,Mars,Mercury,and Venus),as well as the impact craters on ***,we study the advancement achieved in the traditional methods,machine learning methods,and deep learning methods applied to the classification,segmentation,and recognition of impact ***,based on the analysis results,we discuss the existing challenges in impact crater recognition and suggest some ***,we explore the implementation of impact crater detection algorithms and provide a forward-looking perspective.

关键词： Terrestrial planets Deep space exploration Impact crater Impact crater recognition Deep learning

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