Detection of Magnetic Gap in Topological Surface States of MnBi_(2)Te_(4)

Recently,intrinsic antiferromagnetic topological insulator MnBi_(2)Te_(4) has drawn intense research interest and leads to plenty of significant progress in physics and materials science by hosting quantum anomalous Hall effect,axion insulator state,and other quantum phases.An essential ingredient to realize these quantum states is the magnetic gap in the topological surface states induced by the out-of-plane ferromagnetism on the surface of MnBi_(2)Te_(4).However,the experimental observations of the surface gap remain controversial.Here,we report the observation of the surface gap via the point contact tunneling spectroscopy.In agreement with theoretical calculations,the gap size is around 50 me V,which vanishes as the sample becomes paramagnetic with increasing temperature.The magnetoresistance hysteresis is detected through the point contact junction on the sample surface with an out-of-plane magnetic field,substantiating the surface ferromagnetism.Furthermore,the non-zero transport spin polarization coming from the ferromagnetism is determined by the point contact Andreev reflection spectroscopy.Combining these results,the magnetism-induced gap in topological surface states of MnBi_(2)Te_(4) is revealed.

Bibliometric and visualized analysis of applying tumor markers in lung cancer diagnosis from 2000 to 2022

Background Lung cancer(LC)is the leading cause of cancer-related deaths worldwide.Tumor marker(TM)detection can indicate the existence and growth of a tumor and has therefore been used extensively for diagnosing LC.Here,we conducted a bibliometric analysis to examine TM-related publications for LC diagnosis to illustrate the current state and future trends of this field,as well as to identify additional promising TMs with high sensitivity.Methods Publications regarding TMs in LC diagnosis were downloaded from the Web of Science Core Collection.CiteSpace was applied to perform a bibliometric analysis of journals,cocitation authors,keywords,and references related to this field.VOSviewer was used to generate concise diagrams about countries,institutions,authors,and keywords.Changes in the TM research frontier were analyzed through citation burst detection.Results A total of 990 studies were analyzed in this work.The collaboration network analysis revealed that the People's Republic of China,Yonsei University,and Molina R were the most productive country,institution,and scholar,respectively.Additionally,Molina R was the author with the most citations.The National Natural Science Foundation of China was the largest funding source.“Carcinoembryonic antigen(CEA)as tumor marker in lung cancer”was the top reference with the most citations,Lung Cancer was the core journal,and“serum tumor marker”experienced a citation burst over the past 5 years.Conclusion This bibliometric analysis of TMs in LC diagnosis presents the current trends and frontiers in this field.We summarized the research status of this field and the methods to improve the diagnostic efficacy of traditional serum TMs,as well as provided new directions and ideas for improving the LC clinical detection rate.Priority should be given to the transformation of computer-assisted diagnostic technology for clinical applications.In addition,circulating tumor cells,exosomes,and microRNAs were the current most cutting-edge TMs.

Integration of hemicellulose recovery and cold caustic extraction in upgrading a paper-grade bleached kraft pulp to a dissolving grade

In this study,a hemicellulose recovery process was integrated with a cold caustic extraction(CCE)process in upgrading paper-grade bleached kraft pulp to dissolving grade.Under the conditions of 15%NaOH,10%pulp consistency,30℃and 1 h,a paper-grade softwood bleached kraft pulp was purified to a dissolving-grade pulp with 97.57%α-cellulose and 1.67%pentosan contents.The spent liquor from the cold caustic extraction process was sequentially extracted with ethanol to precipitate and recover the dissolved hemicelluloses,followed by evaporation to recover the ethanol.After the recovery of hemicelluloses and ethanol,the spent liquor can be reused as the caustic solution for the CCE process without compromising the resulting pulp properties.The results demonstrated that it is feasible to integrate hemicellulose production with the cold caustic extraction process of dissolving pulp production,based on the concept of biorefinery.