结直肠息肉样病变内镜检查中的常见分型与意义

结直肠癌是常见的恶性肿瘤之一,发病率已居全球癌症发病谱第3位,结直肠息肉的早期检出及切除可以降低结直肠癌发病、死亡风险。在多种检查方法中,结肠镜检查是结直肠癌筛查的“金标准”,结肠镜下结直肠息肉分型通过观察病变黏膜腺管开口形态、毛细血管(微血管)以及表面微结构预测结直肠息肉组织病理学,从而得到广泛应用,对指导下一步治疗方案发挥重要作用。目前镜下结直肠息肉分型主要有巴黎分型、Sano分型、NICE分型、JNET分型、pit pattern分型等。本文对临床常见的结直肠息肉内镜分型的诊断性能、临床意义进行综述,通过分析各分型的敏感度、特异度、准确度及优缺点,旨在为临床选择合适的内镜分型提供参考。

Transition metal embedded in nonmetal-doped T-carbon [110]: A superior synergistic trifunctional electrocatalyst for HER, OER and ORR

The design of efficient and low-cost multifunctional electrocatalysts for hydrogen evolution reaction(HER), oxygen evolution reaction(OER) and oxygen reduction reaction(ORR) is critical for the development of clean energy. Two-dimensional(2D) carbon-based nano-materials are becoming more and more popular in heterogeneous catalysis due to their cost-effective and multi-scale tunability as single-atom catalysis(SACs) substrates. In this paper, by using first-principles calculation, we designed and demonstrated a novel macropore T-carbon [110](TC) monolayer as 2D electrocatalyst substrate for HER/OER/ORR, and the synergistic modification of the transition metal and nonmetal atoms(TM-X) were investigated to enhance the multifunctional electrocatalytic performance. We screened out the Co embedded in N-doped TC(Co3@N-TC) from 30 TM@X-TC monolayers as a trifunctional electrocatalysts, which exhibits superior performance for HER/ORR/OER on both thermodynamic and kinetic scales, and with excellent thermal and electrochemical stability. Then, the TC monolayer is naturally macropore with a diameter of 5.36 A and exhibits excellent adsorption capacity for the intermediates and products of the redox reactions. Moreover, we revealed the origin of the electrocatalytic activity using the crystal orbital Hamilton population(COHP) and the molecular orbitals(MOs). The d orbital of Co3@N-TC is significantly hybridized with the p orbital of the intermediates, so that the lone electrons initially occupied in the antibonding state pair up and occupy the downward bonding state, allowing *OH to be appropriately adsorbed onto the TC monolayer. This work not only demonstrates that the TM@X-TC monolayer is a superior synergistic trifunctional electrocatalyst, but also reveals a macropore monolayer material with potential applications in electrocatalysis.

Resonant enhancement of magnetic damping driven by coherent acoustic phonons in thin Co_(2)FeAl film epitaxied on GaAs

The magnetic dynamics of a thin Co_(2)FeAl film epitaxially grown on GaAs substrate was investigated using the timeresolved magneto-optical Kerr measurement under an out-of-plane external field.The intrinsic magnetic damping constant,which should do not vary with the external magnetic field,exhibits an abnormal huge increase when the precession frequency is tuned to be resonant with that of the coherent longitudinal acoustic phonon in the Co_(2)FeAl/GaAs heterostructure.The experimental finding is suggested to result from the strong coherent energy transfer from spins to acoustic phonons via magnetoelastic effect under a resonant coupling condition,which leads to a huge energy dissipation of spins and a greatly enhanced magnetic damping in Co_(2)FeAl.Our experimental findings provide an experimental evidence of spin pumping-like effect driven by propagating acoustic phonons via magnetoelastic effect,suggesting an alternative approach to the possible long-range spin manipulation via coherent acoustic waves.

Valley dynamics of different excitonic states in monolayer WSe_(2)grown by molecular beam epitaxy

Monolayer transition-metal dichalcogenides possess rich excitonic physics and unique valley-contrasting optical selection rule,and offer a great platform for long spin/valley lifetime engineering and the associated spin/valleytronics exploration.Using two-color time-resolved Kerr rotation and time-resolved reflectivity spectroscopy,we investigate the spin/valley dynamics of different excitonic states in monolayer WSe_(2)grown by molecular beam epitaxy.With fine tuning of the photon energy of both pump and probe beams,the valley relaxation process for the neutral excitons and trions is found to be remarkably different-their characteristic spin/valley lifetimes vary from picoseconds to nanoseconds,respectively.The observed long trion spin lifetime of>2.0 ns is discussed to be associated with the dark trion states,which is evidenced by the photon-energy dependent valley polarization relaxation.Our results also reveal that valley depolarization for these different excitonic states is intimately connected with the strong Coulomb interaction when the optical excitation energy is above the exciton resonance.

Spin depolarization dynamics of WSe_(2) bilayer

In this work,the spin dynamics of a centrosymmetric WSe2 bilayer has been investigated by the two-color timeresolved Kerr rotation together with helicity-resolved transient reflectance techniques.Two depolarization processes associated with the direct transition are discovered at a low temperature of 10 K,with the characteristic decaying time of~3.8 ps and~20 ps,respectively.The short decay time of~3.8 ps is suggested to be the exciton spin lifetime of the WSe2 bilayer,which is limited by the short exciton lifetime of the WSe_(2) bilayer and the rapid intervalley electron–hole exchange interaction between K^(+)and K^(-)valley in the same layer as that of monolayer.The long decay time of~20 ps is suggested to be the spin lifetime of photo-excited electrons,whose spin relaxation is governed by the rapid intervalley scattering from the K valley to the global minimumΣvalley and the subsequent interlayer charge transfer in WSe_(2) bilayer.Our experimental results prove the existence of the spin-polarized excitons and carriers even in centrosymmetric transition metal dichalcogenides(TMDCs)bilayers,suggesting their potential valleytronic and spintronic device applications.

The“mediated molecular”-assisted construction of Mo_(2)N islands dispersed on Co-based nanosheets for high-efficient electrocatalytic hydrogen evolution reaction

The rational design of the catalysts with easily-accessible surface and high intrinsic activity is desirable for electrocatalytic hydrogen evolution reaction(HER).Here,we reported the construction of two-dimensional(2D)Co-Mo nitrides based heterojunctional catalyst for efficient HER based on a“mediated molecular”assisted route.The 2D Co(OH)_(2)sheet reacted partially with the“mediated molecular”(2-methylimidazole(2-MIM))to form zeolitic imidazolate framework(ZIF)-67 at surface,giving ZIF-67/Co(OH)_(2)sheets.The ZIF-67 combines with[PMo_(12)O_(40)]^(3−)cluster(PMo_(12))due to the interaction of mediated molecular with PMo_(12),producing 2D Mo-Co-2MIM/Co(OH)_(2)bimetallic precursor.After controlled nitriding,the Mo_(2)N islands dispersed on 2D porous Co-based sheets were formed.A series of characterizations and density functional theory(DFT)calculation indicated the formation of a close contact interface,which promotes the electron transfer between Mo and Co components,enhances the electron migration/redistribution and redistribution and down-shift of d-band center and thus gives a high intrinsic activity.The 2D characteristics make the catalyst more accessible contact sites,which is favourable to promot the HER.The tests showed that the optimized catalyst exhibits an onset potential of 0 mV and an overpotential of 10 mA·cm^(−2)at 35.0 mV,which is quite close to that of Pt/C catalyst.It also exhibits an activity superior to Pt/C at high current density(>100 mA·cm^(−2)).A good stability of the catalyst was achieved with no significant decay for 100 h of continuous operation.The electrolytic cell composed of optimized catalyst and P-NiFe-layered double hydroxide(LDH)can be driven by low voltage(only 1.47 V)to reach a current density of 10 mA·cm^(−2).

Localization of Oscillation Source in DC Distribution Network Based on Power Spectral Density

Direct current(DC)bus voltage stability is essential for the stable and reliable operation of a DC system.If an oscillation source can be quickly and accurately localized,the oscillation can be adequately eliminated.We propose a method based on the power spectral density for identifying the voltage oscillation source.Specifically,a DC distribution network model combined with the component connection method is developed,and the network is separated into multiple power modules.Compared with a conventional method,the proposed method does not require determining the model parameters of the entire power grid,which is typically challenging.Furthermore,combined with a novel judgment index,the oscillation source can be identified more intuitively and clearly to enhance the applicability to real power grids.The performance of the proposed method has been evaluated using the MATLAB/Simulink software and PLECS RT Box experimental platform.The simulation and experimental results verify that the proposed method can accurately identify oscillation sources in a DC distribution network.

Genomic selection of orange-spotted grouper(Epinephelus coioides)based on multiplex PCR enrichment capture sequencing

Orange spotted grouper(Epinephelus coioides)is an important mariculture fish,and genomic breeding of this grouper species has been hindered due to lack of efficient genotyping tools.Here,we developed a single nucleotide polymorphism(SNP)genotyping technology based on multiplex PCR enrichment capture sequencing,which mainly aims at target area for high-throughput sequencing,and 741 SNPs were designed for genomic selection(GS)of growth and ammonia tolerance traits at the same time.The multiplex PCR enrichment capture sequencing assay showed that the genotyping efficiency was more than 99%in the orange-spotted grouper and the predictive accuracy of body weight and ammonia tolerance traits was 82%and 96%,respectively.More importantly,the average identity of the sequences with these SNPs aligned to the genomes of giant grouper(E.lanceolatus)and brown-marbled grouper(E.fuscoguttatus)were both over 96%.Test data showed that the SNP genotyping efficiency was more than 94%in both giant grouper and brown-marbled grouper.In summary,these results indicated that the development of SNP loci and genotyping approach based on the multiple PCR enrichment capture sequencing are suitable for GS of growth and ammonia tolerance traits in various grouper species,and it would provide technical support for practical grouper breeding.

Nsp2 and GP5-M of Porcine Reproductive and Respiratory Syndrome Virus Contribute to Targets for Neutralizing Antibodies

Porcine reproductive and respiratory syndrome virus(PRRSV)is characterized by its genetic variation and limited cross protection among heterologous strains.Even though several viral structural proteins have been regarded as inducers of neutralizing antibodies(NAs)against PRRSV,the mechanism underlying limited cross-neutralization among heterologous strains is still controversial.In the present study,examinations of NA cross reaction between a highly pathogenic PRRSV(HP-PRRSV)strain,JXwn06,and a low pathogenic PRRSV(LP-PRRSV)strain,HB-1/3.9,were conducted with viral neutralization assays in MARC-145 cells.None of the JXwn06-hyperimmuned pigs’sera could neutralize HB-1/3.9 in vitro and vice versa.To address the genetic variation between these two viruses that are associated with limited crossneutralization,chimeric viruses with coding regions swapped between these two strains were constructed.Viral neutralization assays indicated that variations in nonstructural protein 2(nsp2)and structural proteins together contribute to weak cross-neutralization activity between JXwn06 and HB-1/3.9.Furthermore,we substituted the nsp2-,glycoprotein2(GP2)-,GP3-,and GP4-coding regions together,or nsp2-,GP5-,and membrane(M)protein-coding regions simultaneously between these two viruses to construct chimeric viruses to test cross-neutralization reactivity with hyperimmunized sera induced by their parental viruses.The results indicated that the swapped nsp2 and GP5-M viruses increased the neutralization reactivity with the donor strain antisera in MARC-145 cells.Taken together,these results show that variations in nsp2 and GP5-M correlate with the limited neutralization reactivity between the heterologous strains HP-PRRSV JXwn06 and LP-PRRSV HB-1/3.9.

A genome-wide association study on growth traits in orangespotted grouper(Epinephelus coioides) with RAD-seq genotyping

The orange-spotted grouper, Epinephelus coioides, is one of the most popular fish in China and Southeast Asian countries because of its important economic value. However, molecular mechanism underlying the growth of orange-spotted grouper has never been fully understood. Herein, we performed a genome-wide association study （GWAS） on a natural population of 198 individuals aiming to screen the whole genome of orange-spotted grouper for identification of growth-related loci by restriction-site associated DNA sequencing. In this research, 261,366 single nucleotide polymorphisms （SNPs） were developed, in which 110 SNPs were identified to be correlated with growth and 20 SNPs were further confirmed to be associated with both body weight and total length. From these identified SNPs, we annotated a total of 34 genes, including adgrb2, csnkzal, cers5, co122al, creb5, dndl, dzankl, dnail, npy2r, fat3, lrrk2, lrp5, map3k9, and so on. Among these candidate genes, npy2r （neuropeptide Y receptor Y2） was reported to play a critical role in growth of the orange-spotted grouper. In addition, population structure, principal component analysis, kinship matrix and linkage disequilibrium were examined to verify the accuracy and reliability of our GWAS results. Our data will also provide a valuable genetic resource for further marker-assisted selection program to improve growth quality in groupers.

An ultrapotent RBD-targeted biparatopic nanobody neutralizes broad SARS-CoY-2 variants

The wide transmission and host adaptation of SARS-CoV-2 have led to the rapid accumulation of mutations,posing significant challenges to the effectiveness of vaccines and therapeutic antibodies.Although several neutralizing antibodies were authorized for emergency clinical use,convalescent patients derived natural antibodies are vulnerable to SARS-CoV-2 Spike mutation.

Discovery of thiosemicarbazone derivatives as effective New Delhi metallo-β-lactamase-1(NDM-1) inhibitors against NDM-1 producing clinical isolates

New Delhi metallo-b-lactamase-1(NDM-1)is capable of hydrolyzing nearly allβ-lactam antibiotics,posing an emerging threat to public health.There are currently less effective treatment options for treating NDM-1 positive"superbug",and no promising NDM-1 inhibitors were used in clinical practice.In this study,structure eactivity relationship based on thiosemicarbazone derivatives wassystematically characterized and their potential activities combined with meropenem(MEM)were evaluated.Compounds 19 bg and 19 bh exhibited excellent activity against 10 NDM-positive isolate clinical isolates in reversing MEM resistance.Further studies demonstrated compounds 19 bg and 19 bh were uncompetitive NDM-1 inhibitors with Ki Z 0.63 and 0.44 mmol/L,respectively.Molecular docking speculated that compounds 19 bg and 19 bh were most likely to bind in the allosteric pocket which would affect the catalytic effect of NDM-1 on the substrate meropenem.Toxicity evaluation experiment showed that no hemolysis activities even at concentrations of 1000 mg/m L against red blood cells.In vivo experimental results showed combination of MEM and compound 19 bh was markedly effective in treating infections caused by NDM-1 positive strain and prolonging the survival time of sepsis mice.Our finding showed that compound 19 bh might be a promising lead in developing new inhibitor to treat NDM-1 producing superbug.

A PRODUCTION OPTIMIZATION MODEL OF SUPPLY-DRIVEN CHAIN WITH QUALITY UNCERTAINTY

Supply-driven chain＇s production is different from traditional demand-driven production because its supplies must guide the full production flow toward the markets and respond actively to customer demand. According to the control tlaeory, a novel multi-variable operation model of supply-driven chain is discussed here, integrating suppliers, manufacturers, distributors and market demands. Especially the coordination problem between suppliers and manufacturers is discussed where suppliers play more important role than manufacturers. Because defect is common in real production system, the production operation of supply-driven chain with imperfect quality is described on the basis of fuzzy set to model the ambiguity of quality and to provide appropriate supply coordination mechanism. In a designed numerical example, it is apparent that both response and robustness performances of supply-driven production system on demand with imperfect quality are improved by a fuzzy proportional-integral- differential regulator. The proposed model may apply to similar productions with imoerfect quality.

Situation,Challenges,and Countermeasures of Home-Based Healthcare Service Supply and Demand in China

According to the Seventh National Census of China,the population of adults aged 65 and above will be 190 million in 2020(13.5%of the total population).As the“post-60s”group born at the second childbirth peak reaches retirement age,the growth rate of the population of older adults will accelerate significantly.By 2030,the proportion of older population(aged 65 and above)will reach about 17%,and the growth rate of the population aged 80 and above will be even more pronounced.

Fall Injuries and Depressive Symptoms Among Older Adults and the Mediating Effects of Social Participation—China,2011–2018

Summary What is already known on this topic?Prior studies found that fall events were associated with a higher level of depressive symptoms and a lower level of social functioning and social participation.In addition,social participation has also been significantly associated with better conditions of depressive symptoms.What is added by this report?

Longitudinal Association Between Oral Status and Depressive Symptoms Among Chinese Older Adults—China,2014–2018

Summary What is already known about this topic?Previous studies on the importance of oral health in later life have mainly focused on nutritional and physical health indicators,while the effects of oral status on the mental health of older people,especially on depression,need to be further explored.What is added by this report?