BACKGROUND:This study aims to explore whether Xuebijing(XBJ) can improve intestinal microcirculation dysfunction in sepsis and its mechanism.METHODS:A rat model of sepsis was established by cecal ligation and puncture...BACKGROUND:This study aims to explore whether Xuebijing(XBJ) can improve intestinal microcirculation dysfunction in sepsis and its mechanism.METHODS:A rat model of sepsis was established by cecal ligation and puncture(CLP).A total of 30 male SD rats were divided into four groups:sham group,CLP group,XBJ + axitinib group,and XBJ group.XBJ was intraperitoneally injected 2 h before CLP.Hemodynamic data(blood pressure and heart rate) were recorded.The intestinal microcirculation data of the rats were analyzed via microcirculation imaging.Enzyme-linked immunosorbent assay(ELISA) kits were used to detect the serum levels of interleukin-6(IL-6),C-reactive protein(CRP),and tumor necrosis factor-α(TNF-α) in the rats.Histological analysis and transmission electron microscopy were used to analyze the injury of small intestinal microvascular endothelial cells and small intestinal mucosa in rats.The expression of vascular endothelial growth factor A(VEGF-A),phosphoinositide 3-kinase(PI3K),phosphorylated PI3K(p-PI3K),protein kinase B(Akt),and phosphorylated Akt(p-Akt) in the small intestine was analyzed via Western blotting.RESULTS:XBJ improved intestinal microcirculation dysfunction in septic rats,alleviated the injury of small intestinal microvascular endothelial cells and small intestinal mucosa,and reduced the systemic inflammatory response.Moreover,XBJ upregulated the expression of VEGF-A,p-PI3K/total PI3K,and p-Akt/total Akt in the rat small intestine.CONCLUSION:XBJ may improve intestinal microcirculation dysfunction in septic rats possibly through the VEGF-A/PI3K/Akt signaling pathway.展开更多
Traditional particle identification methods face timeconsuming,experience-dependent,and poor repeatability challenges in heavy-ion collisions at low and intermediate energies.Researchers urgently need solutions to the...Traditional particle identification methods face timeconsuming,experience-dependent,and poor repeatability challenges in heavy-ion collisions at low and intermediate energies.Researchers urgently need solutions to the dilemma of traditional particle identification methods.This study explores the possibility of applying intelligent learning algorithms to the particle identification of heavy-ion collisions at low and intermediate energies.Multiple intelligent algorithms,including XgBoost and TabNet,were selected to test datasets from the neutron ion multi-detector for reaction-oriented dynamics(NIMROD-ISiS)and Geant4 simulation.Tree-based machine learning algorithms and deep learning algorithms e.g.TabNet show excellent performance and generalization ability.Adding additional data features besides energy deposition can improve the algorithm’s performance when the data distribution is nonuniform.Intelligent learning algorithms can be applied to solve the particle identification problem in heavy-ion collisions at low and intermediate energies.展开更多
BACKGROUND Lichen amyloidosis(LA)is a chronic,severely pruritic skin disease,which is the most common form of primary cutaneous amyloidosis.The treatment of LA has been considered to be difficult.LA may be associated ...BACKGROUND Lichen amyloidosis(LA)is a chronic,severely pruritic skin disease,which is the most common form of primary cutaneous amyloidosis.The treatment of LA has been considered to be difficult.LA may be associated with atopic dermatitis(AD),and in this setting,the treatment options may be more limited.Herein,we report four cases of LA associated with AD successfully treated by dupilumab.CASE SUMMARY In this article,we describe four cases of patients who presented with recurrent skin rash accompanied by severe generalized intractable pruritus,diagnosed with refractory LA coexisting with chronic AD.Previous treatments had not produced any apparent improvement.Thus,we administered dupilumab injection subcutaneously at a dose of 600 mg for the first time and 300 mg every 2 wk thereafter.Their lesions all markedly improved.CONCLUSION Dupilumab may be a new useful treatment for LA coexisting with AD.展开更多
AIM to compare the outcomes of preoperative endoscopic nasobiliary drainage (ENBD) and endoscopic retrograde biliary drainage (ERBD) in patients with malignant distal biliary obstruction prior to pancreaticoduodenecto...AIM to compare the outcomes of preoperative endoscopic nasobiliary drainage (ENBD) and endoscopic retrograde biliary drainage (ERBD) in patients with malignant distal biliary obstruction prior to pancreaticoduodenectomy (PD). METHODS Data from 153 consecutive patients who underwent preoperative endoscopic biliary drainage prior to PD between January 2009 and July 2016 were analyzed. We compared the clinical data, procedure-related complications of endoscopic biliary drainage (EBD) and postoperative complications of PD between the ENBD and ERBD groups. Univariate and multivariate analyses with odds ratios (ORs) and 95% confidence intervals (95% CIs) were used to identify the risk factors for deep abdominal infection after PD. RESULTS One hundred and two (66.7%) patients underwent ENBD, and 51 (33.3%) patients underwent ERBD. Endoscopic sphincterotomy was less frequently performed in the ENBD group than in the ERBD group (P = 0.039); the EBD duration in the ENBD group was shorter than that in the ERBD group (P = 0.036). After EBD, the levels of total bilirubin (TB) and alanine aminotransferase (ALT) were obviously decreased in both groups, and the decreases of TB and ALT in the ERBD group were greater than those in the ENBD group (P = 0.004 and P = 0.000, respectively). However, the rate of EBD procedure-related cholangitis was significantly higher in the ERBD group than in the ENBD group (P = 0.007). The postoperative complications of PD as graded by the Clavien-Dindo classification system were not significantly different between the two groups (P = 0.864). However, the incidence of deep abdominal infection after PD was significantly lower in the ENBD group than in the ERBD group (P = 0.019). Male gender (OR = 3.92; 95% CI: 1.63-9.47; P = 0.002), soft pancreas texture (OR = 3.60; 95% CI: 1.37-9.49; P = 0.009), length of biliary stricture (= 1.5 cm) (OR = 5.20; 95% CI: 2.23-12.16; P = 0.000) and ERBD method (OR = 4.08; 95% CI: 1.69-9.87; P = 0.002) were independent risk factors for deep abdominal infection after PD. CONCLUSION ENBD is an optimal method for patients with malignant distal biliary obstruction prior to PD. ERBD is superior to ENBD in terms of patient tolerance and the effect of biliary drainage but is associated with an increased risk of EBD procedure-related cholangitis and deep abdominal infection after PD. (C) The Author(s) 2017. Published by Baishideng Publishing Group Inc. All rights reserved.展开更多
AIM: To evaluate the expression of galectin-1 and vascular endothelial growth factor (VEGF) in gastric cancer and investigate their relationships with clinicopathologic factors and prognostic significance. METHODS: Ga...AIM: To evaluate the expression of galectin-1 and vascular endothelial growth factor (VEGF) in gastric cancer and investigate their relationships with clinicopathologic factors and prognostic significance. METHODS: Galectin-1 and VEGF were immunohistochemically investigated in tumor samples obtained from 214 gastric cancer patients with all tumor stages. Immunohistochemical analyses for galectin-1 and VEGF expression were performed on formalin-fixed, paraffin-embedded sections of surgical specimens. The relationship between the expression and staining intensity of galectin-1 and VEGF, clinicopathologic variables, and patient survival were analyzed. All patients underwent follow-up until cancer-related death or more than five years after tumor resection. P values < 0.05 were considered statistically significant.RESULTS: Immunohistochemical staining demonstrated that 138 of 214 gastric cancer samples (64.5%) were positive for galectin-1, and 116 out of 214 gastric cancer samples (54.2%) were positive for VEGF. There was a significant association between galectin-1 and VEGF expression; VEGF was detected in 60.1% of galectin-1-positive samples and 43.4% of galectin-1-negative samples (P < 0.05). Galectin-1 expression was associated with tumor size, tumor location, stage, lymph node metastases, and VEGF expression (all P < 0.05). VEGF expression was related to tumor size, stage, and lymph node metastases (all P < 0.05). The 5-year survival rate was 56.6% for galectin-1-positive patients and 69.2% for galectin-1-negative patients, and the prognosis for galectin-1-positive patients was significantly poorer compared with galectin-1-negative patients (χ 2 = 13.880, P = 0.000). The 5-year survival rates for VEGF-positive and VEGF-negative patients were 53.4% and 70.5%, respectively (χ2 = 4.619, P = 0.032). The overall survival rate of patients with both galectin-1 and VEGF overexpression in gastric cancer tissue samples was significantly poorer than other groups (both P < 0.05).CONCLUSION: Galectin-1 expression was positively associated with VEGF expression. Both galectin-1 and VEGF can serve as independent prognostic indicators of poor survival for gastric cancer after gastrectomy.展开更多
BACKGROUND:Intestinal microcirculation dysfunction is an important factor that causes poor prognosis in sepsis patients and is an important pathophysiological basis for the occurrence and development of sepsis.DATA RE...BACKGROUND:Intestinal microcirculation dysfunction is an important factor that causes poor prognosis in sepsis patients and is an important pathophysiological basis for the occurrence and development of sepsis.DATA RESOURCES:PubMed,Web of Science,and China National Knowledge Infrastructure(CNKI)were searched from inception to August 1,2021.The search was limited to the English language only.Two reviewers independently identified studies related to intestinal microcirculation dysfunction in sepsis.Exclusion criteria were duplicate articles according to multiple search criteria.RESULTS:Fifty articles were included,and most of them were animal studies.These studies reported pathogenesis,including endothelial dysfunction,leukocyte recruitment and adhesion,microthrombus formation,microcirculation hypoperfusion,and redistribution of intestinal wall blood flow.The monitoring methods of intestinal microcirculation were also diverse,including handheld microscopes,intravital microscopy(IVM),laser Doppler blood flow instruments,laser speckle contrast imaging,tissue refl ectance spectrophotometry,biochemical markers of intestinal ischemia,and histopathological examination.In view of the related pathogenesis of intestinal microcirculation disorder in sepsis,existing studies also have diff erent opinions on its treatment.CONCLUSIONS:Limited by monitoring,there are few clinical studies on intestinal microcirculation dysfunction in sepsis.Related research mainly focuses on basic research,but some progress has also been made.Therefore,this review may provide a reference for future research on intestinal microcirculation dysfunction in sepsis.展开更多
With the development of laser technologies,nuclear reactions can happen in high-temperature plasma environments induced by lasers and have attracted a lot of attention from different physical disciplines.However,studi...With the development of laser technologies,nuclear reactions can happen in high-temperature plasma environments induced by lasers and have attracted a lot of attention from different physical disciplines.However,studies on nuclear reactions in plasma are still limited by detecting technologies.This is mainly due to the fact that extremely high electromagnetic pulses(EMPs)can also be induced when high-intensity lasers hit targets to induce plasma,and then cause dysfunction of many types of traditional detectors.Therefore,new particle detecting technologies are highly needed.In this paper,we report a recently developed gated fiber detector which can be used in harsh EMP environments.In this prototype detector,scintillating photons are coupled by fiber and then transferred to a gated photomultiplier tube which is located far away from the EMP source and shielded well.With those measures,the EMPs can be avoided which may result that the device has the capability to identify a single event of nuclear reaction products generated in laser-induced plasma from noise EMP backgrounds.This new type of detector can be widely used as a time-of-flight(TOF)detector in high-intensity laser nuclear physics experiments for detecting neutrons,photons,and other charged particles.展开更多
Flavonoids,which are a diverse class of phytonutrients,are used by organisms to respond to nearly all abiotic stresses and are beneficial for human health.Glycosyltransferase,used during the last step of flavonoid bio...Flavonoids,which are a diverse class of phytonutrients,are used by organisms to respond to nearly all abiotic stresses and are beneficial for human health.Glycosyltransferase,used during the last step of flavonoid biosynthesis,is important in flavonoid enrichment.However,little is known about glycosyltransferase in the orchid Dendrobium catenatum(D.officinale).In this study,we isolated a novel C-glycosyltransferase(designated DcaCGT)from the orchid D.catenatum by identifying and analyzing 82 putative genes in the GT1 family.DcaCGT could specifically catalyze not only di-C-glycosylation but also O-glycosylation.Apart from the normal function of catalyzing 2-hydroxynaringenin and phloretin to the respective di-C-glycosides,DcaCGT also catalyzes apigenin to cosmosiin.Targeted metabolic profiling of the substrates(2-hydroxynaringenin,phloretin,and apigenin)and products(vitexin,isovitexin,vicenin-2,nothofagin,3’,5’-di-C-glucosylphloretin,and cosmosiin)in different tissues showed that vicenin-2 was the most abundant product of this novel enzyme.Cosmosiin was detected in flowers and flower buds.We also established that DcaCGT functions expanded throughout the evolution of D.catenatum.Residual OGT activity may help D.catenatum resist drought stress.Our study illustrates the function,origin,and differentiation of DcaCGT and provides insights into glycosylation and molecular propagation processes,which can be used to improve the production of flavonoids by the cultivated medicinal plant D.catenatum.展开更多
BACKGROUND:Sepsis-induced liver injury is a fatal complication of sepsis.Trichostatin A(TSA)regulates inflammation and autophagy in some human diseases,and forkhead box O3a(FoxO3a)has been shown to regulate autophagy....BACKGROUND:Sepsis-induced liver injury is a fatal complication of sepsis.Trichostatin A(TSA)regulates inflammation and autophagy in some human diseases,and forkhead box O3a(FoxO3a)has been shown to regulate autophagy.The present study aims to investigate whether TSA exerts its effects on septic liver injury through the FoxO3a/autophagy signaling pathway.METHODS:A sepsis mouse model was constructed by the cecal ligation and puncture(CLP)method,and AML12 cells were pretreated with lipopolysaccharide(LPS)(1μg/mL)to establish a sepsis cell model.Forty mice were divided into four groups,namely control group,TSA group,CLP group,and CLP+TSA group,with 10 mice in each group.Cells were divided into control group,TSA group,LPS group,and LPS+TSA group.Hematoxylin-eosin(H&E)staining and biochemical methods were used to evaluate liver tissue injury.Enzyme-linked immunosorbent assay(ELISA)was applied to detect the expression of proinflammatory cytokines,and Western blotting and immunofluorescence were used to measure autophagy-related protein expression.RESULTS:Compared with the CLP group(mice),the proinflammatory cytokines(interleukin-β[IL-β]2,665.27±324.90 pg/mL to 2,080.26±373.66 pg/mL;interleukin-6[IL-6]399.01±60.98 pg/mL to 221.90±46.89 pg/mL)and the hepatocyte injury markers(aspartate transaminase[AST]from 198.18±27.07 U/L to 128.42±20.55 U/L;alanine aminotransferase[ALT]from 634.98±74.10 U/L to 478.60±32.56 U/L)were notably decreased after TSA intervention.Moreover,LC3 II and FoxO3a showed an obvious increase and P62 showed an obvious decrease in the CLP+TSA group.Cell experiment results showed the similar trend.After Fox O3a gene was knocked down in AML12 cells,the promotion of autophagy and the improvement of liver enzyme index and inflammation by TSA were weakened.CONCLUSION:TSA may improve the inflammatory response and liver injury in septic mice through Fox O3a/autophagy.展开更多
The isomer ^(229m)Th is the most promising candidate for clocks based on the nuclear transition because it has the lowest excitation energy of only 8.10±0.17 eV.Various experiments and theories have focused on me...The isomer ^(229m)Th is the most promising candidate for clocks based on the nuclear transition because it has the lowest excitation energy of only 8.10±0.17 eV.Various experiments and theories have focused on methods of triggering the transition between the ground state and isomeric state,among which the electronic bridge(EB)is one of the most efficient.In this paper,we propose a new electronic bridge mechanism via two-photon excitation based on quantum optics for a two-level nuclear quantum system.The long-lived 7 s1/2 electronic shell state of^(229m)Th^(3+),with a lifetime of approximately 0.6 s,is chosen as the initial state and the atomic shells(7 s-10 s)could be achieved as virtual states in a two-photon process.When the virtual states return to the initial state 7 s1/2,there is a chance of triggering the nucleus 229Th^(3+),to its isomeric state ^(229m)Th ^(3+),via EB.Two lasers at moderate intensity((10^(10)-10^(14))W/m^(2)),with photon energies near the optical range,are expected to populate the isomer at a saturated rate of approximately 10^(9) s^(-1),which is much higher than that due to other mechanisms.We believe that this twophoton EB scheme can help in the development of nuclear clocks and deserves verification via a series of experiments with ordinary lasers in laboratories.展开更多
Cymbidium,which includes approximately 80 species,is one of the most ornamental and cultivated orchid genera.However,a lack of markers and sparse sampling have posed great challenges to resolving the phylogenetic rela...Cymbidium,which includes approximately 80 species,is one of the most ornamental and cultivated orchid genera.However,a lack of markers and sparse sampling have posed great challenges to resolving the phylogenetic relationships within the genus.In the present study,we reconstructed the phylogenetic relationships by utilizing one nuclear DNA(nrITS)and seven plastid genes(rbcL,trnS,trnG,matK,trnL,psbA,and atpI)from 70 species(varieties)in Cymbidium.We also examined the occurrence of phylogenetic conflict between nuclear(nrITS)and plastid loci and investigated how phylogenetic conflict bears on taxonomic classification within the genus.We found that phylogenetic conflict and low support values may be explained by hybridization and a lack of informative characteristics.Our results do not support previous classification of the subgenera and sections within Cymbidium.Discordance between gene trees and network analysis indicate that reticulate evolution occurred in the genus Cymbidium.Overall,our study indicates that Cymbidium has undergone a complex evolution.展开更多
As one of the largest families of angiosperms,the Orchidaceae family is diverse.Dendrobium represents the second largest genus of the Orchidaceae.However,an assembled high-quality genome of species in this genus is la...As one of the largest families of angiosperms,the Orchidaceae family is diverse.Dendrobium represents the second largest genus of the Orchidaceae.However,an assembled high-quality genome of species in this genus is lacking.Here,we report a chromosome-scale reference genome of Dendrobium chrysotoxum,an important ornamental and medicinal orchid species.The assembled genome size of D.chrysotoxum was 1.37 Gb,with a contig N50 value of 1.54 Mb.Of the sequences,95.75%were anchored to 19 pseudochromosomes.There were 30,044 genes predicted in the D.chrysotoxum genome.Two whole-genome polyploidization events occurred in D.chrysotoxum.In terms of the second event,whole-genome duplication(WGD)was also found to have occurred in other Orchidaceae members,which diverged mainly via gene loss immediately after the WGD event occurred;the first duplication was found to have occurred in most monocots(tau event).We identified sugar transporter(SWEET)gene family expansion,which might be related to the abundant medicinal compounds and fleshy stems of D.chrysotoxum.MADS-box genes were identified in D.chrysotoxum,as well as members of TPS and Hsp90 gene families,which are associated with resistance,which may contribute to the adaptive evolution of orchids.We also investigated the interplay among carotenoid,ABA,and ethylene biosynthesis in D.chrysotoxum to elucidate the regulatory mechanisms of the short flowering period of orchids with yellow flowers.The reference D.chrysotoxum genome will provide important insights for further research on medicinal active ingredients and breeding and enhances the understanding of orchid evolution.展开更多
To explore the specimen size effect of mechanical behavior of ultrafine-grained(UFG)materials with different structures,UFG Al sheets processed by equal channel angular pressing(ECAP)were selected as target materials ...To explore the specimen size effect of mechanical behavior of ultrafine-grained(UFG)materials with different structures,UFG Al sheets processed by equal channel angular pressing(ECAP)were selected as target materials and the dependency of tensile behavior on sheet thickness(t)was systematically investigated.The strength and ductility of ECAPed UFG Al sheets were improved synchronously as t increased from 0.2 to 0.7 mm,and then no apparent change occurred when t reached to 0.7 and 1.0 mm.The corresponding microstructure evolved from dislocation networks in equiaxed grains into the walls and subgrains and finally into the dominated cells in elongated grains or subgrains.Meanwhile,dense shear lines(SLs)and shear bands(SBs)were clearly observed and microvoids and cracks were initiated along SBs with the increase of t.These observations indicated that the plastic deformation of UFG Al sheets was jointly controlled by shear banding,dislocation sliding,and grain-boundary sliding.Furthermore,the propagation of SBs became difficult as t increased.Finally,the obtained results were discussed and compared with those of annealed UFG Al and UFG Cu.展开更多
Investigating deuteron–deuteron(DD)fusion reactions in a plasma environment similar to the early stages of the Big Bang is an important topic in nuclear astrophysics.In this study,we experimentally investigated such ...Investigating deuteron–deuteron(DD)fusion reactions in a plasma environment similar to the early stages of the Big Bang is an important topic in nuclear astrophysics.In this study,we experimentally investigated such reactions,using eight laser beams with the third harmonic impacting on a deuterated polyethylene target at the ShenGuang-II Upgrade laser facility.This work focused on the application of range-filter(RF)spectrometers,assembled from a 70 lm aluminum filter and two CR-39 nuclear track detectors,to measure the yields of primary DD-protons.Based on the track diameter calibration results of 3 MeV protons used to diagnose the tracks on the RF spectrometers,an approximate primary DD-proton yield of(8.5±1.7)×10^6 was obtained,consistent with the yields from similar laser facilities worldwide.This indicates that the RF spectrometer is an effective way to measure primary DD-protons.However,due to the low yields of D^3He-protons and its small track diameter,CR-39 detectors were unable to distinguish it from the background spots.Using other accurate detectors may help to measure these rare events.展开更多
Charged particle diagnosis is an important aspect of laser–plasma experiments conducted at super-intense laser facilities. In recent years, Columbia Resin #39 (CR- 39) detectors have been widely employed for detectin...Charged particle diagnosis is an important aspect of laser–plasma experiments conducted at super-intense laser facilities. In recent years, Columbia Resin #39 (CR- 39) detectors have been widely employed for detecting charged particles in laser–plasma experiments. This is because the CR-39 polymer does not respond to electromagnetic pulses or X-rays. This study presents a method for calibrating the relationship between particle energy and track diameter in a CR-39 detector (TasTrak■) using 3-8 MeV protons, 6-30 MeV carbon ions, and 1–5 MeV alpha particles. The particle tracks were compared under the manufacturer’s recommended etching conditions of 6.25 mol/l NaOH at 98℃ and under the widely adopted experimental conditions of 6.25 mol/l NaOH at 70℃. The results show that if the NaOH solution concentration is 6.25 mol/l, then the temperature of 70℃is more suitable for etching proton tracks than 98℃ and employing a temperature of 98 ℃ to etch alpha-particle and carbon-ion tracks can significantly reduce the etching time. Moreover, this result implies that C3+ ion or alpha-particle tracks can be distinguished from proton tracks with energy above 3 MeV by controlling the etching time. This calibration method for the CR-39 detector can be applied to the diagnosis of reaction products in laser–plasma experiments.展开更多
To explore the influence of cyclic pre-deformation on the mechanical behavior of ultrafine-grained（UFG）materials with a high stacking fault energy（SFE）,UFG Al processed by equal-channel angular pressing（ECAP）was...To explore the influence of cyclic pre-deformation on the mechanical behavior of ultrafine-grained（UFG）materials with a high stacking fault energy（SFE）,UFG Al processed by equal-channel angular pressing（ECAP）was selected as a target material and its tensile behavior at different pre-cyclic levels D（D=N_i/N_f,where N_i and N_f are the applied cycles and fatigue life at a constant stress amplitude of 50 MPa,respectively）along with the corresponding microstructures and deformation features were systematically studied.The cyclic pre-deformation treatment on the ECAPed UFG Al led to a decrease in flow stress,and a stress quasi-plateau stage was observed after yielding for all of the different-state UFG Al samples.The yield strengths_（YS）,ultimate tensile strengths_（UTS）,and uniform straineexhibited a strong dependence on D when D≤20%;however,when D was in the range from 20%to 50%,no obvious change in mechanical properties was observed.The micro-mechanism for the effect of cyclic pre-deformation on the tensile properties of the ECAPed UFG Al was revealed and compared with that of ECAPed UFG Cu through the observations of deformation features and microstructures.展开更多
We study the dissipative quantum phase transition(QPT)in a biased Tavis–Cummings model consisting of an ensemble of two-level systems(TLSs)interacting with a cavity mode,where the TLSs are pumped by a drive field.In ...We study the dissipative quantum phase transition(QPT)in a biased Tavis–Cummings model consisting of an ensemble of two-level systems(TLSs)interacting with a cavity mode,where the TLSs are pumped by a drive field.In our proposal,we use a dissipative TLS ensemble and an active cavity with effective gain.In the weak drive-field limit,the QPT can occur under the combined actions of the loss and gain of the system.Owing to the active cavity,the QPT behavior can be much differentiated even for a finite strength of the drive field on the TLS ensemble.Also,we propose to implement our scheme based on the dissipative nitrogen-vacancy(NV)centers coupled to an active optical cavity made from the gainmedium-doped silica.Furthermore,we show that the QPT can be measured by probing the transmission spectrum of the cavity embedding the ensemble of the NV centers.展开更多
The neutron yield in the12C(d,n)13N reaction and the proton yield in the12C(d,p)13C reaction have been measured using deuteron beams of energies 0.6-3 MeV.The deuteron beam is delivered from a 4-MeV electrostatic acce...The neutron yield in the12C(d,n)13N reaction and the proton yield in the12C(d,p)13C reaction have been measured using deuteron beams of energies 0.6-3 MeV.The deuteron beam is delivered from a 4-MeV electrostatic accelerator and bombarded on a thick carbon target.The neutrons are detected at 0°,24°,and 48°and the protons at135°in the laboratory frame.Further,the ratio of the neutron yield to the proton yield was calculated.This can be used to effectively recognize the resonances.The resonances are found at 1.4 MeV,1.7 MeV,and 2.5 MeV in the12C(d,p)13C reaction,and at 1.6 MeV and 2.7 MeV in the12C(d,n)13N reaction.The proposed method provides a way to reduce systematic uncertainty and helps confirm more resonances in compound nuclei.展开更多
1.Introduction Sudden cardiac death(SCD)refers to sudden death due to a variety of cardiac causes.It is manifested as a sudden loss of consciousness,cardiac arrest,and respiratory arrest and generally shows early symp...1.Introduction Sudden cardiac death(SCD)refers to sudden death due to a variety of cardiac causes.It is manifested as a sudden loss of consciousness,cardiac arrest,and respiratory arrest and generally shows early symptoms that are atypical and not easily detected[1].According to a recent study,nearly 544000 patients suffer from SCD every year in China[2].展开更多
基金supported by a grant from National Natural Science Foundation of China (82272196)。
文摘BACKGROUND:This study aims to explore whether Xuebijing(XBJ) can improve intestinal microcirculation dysfunction in sepsis and its mechanism.METHODS:A rat model of sepsis was established by cecal ligation and puncture(CLP).A total of 30 male SD rats were divided into four groups:sham group,CLP group,XBJ + axitinib group,and XBJ group.XBJ was intraperitoneally injected 2 h before CLP.Hemodynamic data(blood pressure and heart rate) were recorded.The intestinal microcirculation data of the rats were analyzed via microcirculation imaging.Enzyme-linked immunosorbent assay(ELISA) kits were used to detect the serum levels of interleukin-6(IL-6),C-reactive protein(CRP),and tumor necrosis factor-α(TNF-α) in the rats.Histological analysis and transmission electron microscopy were used to analyze the injury of small intestinal microvascular endothelial cells and small intestinal mucosa in rats.The expression of vascular endothelial growth factor A(VEGF-A),phosphoinositide 3-kinase(PI3K),phosphorylated PI3K(p-PI3K),protein kinase B(Akt),and phosphorylated Akt(p-Akt) in the small intestine was analyzed via Western blotting.RESULTS:XBJ improved intestinal microcirculation dysfunction in septic rats,alleviated the injury of small intestinal microvascular endothelial cells and small intestinal mucosa,and reduced the systemic inflammatory response.Moreover,XBJ upregulated the expression of VEGF-A,p-PI3K/total PI3K,and p-Akt/total Akt in the rat small intestine.CONCLUSION:XBJ may improve intestinal microcirculation dysfunction in septic rats possibly through the VEGF-A/PI3K/Akt signaling pathway.
基金This work was supported by the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDB34030000)the National Key Research and Development Program of China(No.2022YFA1602404)+1 种基金the National Natural Science Foundation(No.U1832129)the Youth Innovation Promotion Association CAS(No.2017309).
文摘Traditional particle identification methods face timeconsuming,experience-dependent,and poor repeatability challenges in heavy-ion collisions at low and intermediate energies.Researchers urgently need solutions to the dilemma of traditional particle identification methods.This study explores the possibility of applying intelligent learning algorithms to the particle identification of heavy-ion collisions at low and intermediate energies.Multiple intelligent algorithms,including XgBoost and TabNet,were selected to test datasets from the neutron ion multi-detector for reaction-oriented dynamics(NIMROD-ISiS)and Geant4 simulation.Tree-based machine learning algorithms and deep learning algorithms e.g.TabNet show excellent performance and generalization ability.Adding additional data features besides energy deposition can improve the algorithm’s performance when the data distribution is nonuniform.Intelligent learning algorithms can be applied to solve the particle identification problem in heavy-ion collisions at low and intermediate energies.
文摘BACKGROUND Lichen amyloidosis(LA)is a chronic,severely pruritic skin disease,which is the most common form of primary cutaneous amyloidosis.The treatment of LA has been considered to be difficult.LA may be associated with atopic dermatitis(AD),and in this setting,the treatment options may be more limited.Herein,we report four cases of LA associated with AD successfully treated by dupilumab.CASE SUMMARY In this article,we describe four cases of patients who presented with recurrent skin rash accompanied by severe generalized intractable pruritus,diagnosed with refractory LA coexisting with chronic AD.Previous treatments had not produced any apparent improvement.Thus,we administered dupilumab injection subcutaneously at a dose of 600 mg for the first time and 300 mg every 2 wk thereafter.Their lesions all markedly improved.CONCLUSION Dupilumab may be a new useful treatment for LA coexisting with AD.
文摘AIM to compare the outcomes of preoperative endoscopic nasobiliary drainage (ENBD) and endoscopic retrograde biliary drainage (ERBD) in patients with malignant distal biliary obstruction prior to pancreaticoduodenectomy (PD). METHODS Data from 153 consecutive patients who underwent preoperative endoscopic biliary drainage prior to PD between January 2009 and July 2016 were analyzed. We compared the clinical data, procedure-related complications of endoscopic biliary drainage (EBD) and postoperative complications of PD between the ENBD and ERBD groups. Univariate and multivariate analyses with odds ratios (ORs) and 95% confidence intervals (95% CIs) were used to identify the risk factors for deep abdominal infection after PD. RESULTS One hundred and two (66.7%) patients underwent ENBD, and 51 (33.3%) patients underwent ERBD. Endoscopic sphincterotomy was less frequently performed in the ENBD group than in the ERBD group (P = 0.039); the EBD duration in the ENBD group was shorter than that in the ERBD group (P = 0.036). After EBD, the levels of total bilirubin (TB) and alanine aminotransferase (ALT) were obviously decreased in both groups, and the decreases of TB and ALT in the ERBD group were greater than those in the ENBD group (P = 0.004 and P = 0.000, respectively). However, the rate of EBD procedure-related cholangitis was significantly higher in the ERBD group than in the ENBD group (P = 0.007). The postoperative complications of PD as graded by the Clavien-Dindo classification system were not significantly different between the two groups (P = 0.864). However, the incidence of deep abdominal infection after PD was significantly lower in the ENBD group than in the ERBD group (P = 0.019). Male gender (OR = 3.92; 95% CI: 1.63-9.47; P = 0.002), soft pancreas texture (OR = 3.60; 95% CI: 1.37-9.49; P = 0.009), length of biliary stricture (= 1.5 cm) (OR = 5.20; 95% CI: 2.23-12.16; P = 0.000) and ERBD method (OR = 4.08; 95% CI: 1.69-9.87; P = 0.002) were independent risk factors for deep abdominal infection after PD. CONCLUSION ENBD is an optimal method for patients with malignant distal biliary obstruction prior to PD. ERBD is superior to ENBD in terms of patient tolerance and the effect of biliary drainage but is associated with an increased risk of EBD procedure-related cholangitis and deep abdominal infection after PD. (C) The Author(s) 2017. Published by Baishideng Publishing Group Inc. All rights reserved.
文摘AIM: To evaluate the expression of galectin-1 and vascular endothelial growth factor (VEGF) in gastric cancer and investigate their relationships with clinicopathologic factors and prognostic significance. METHODS: Galectin-1 and VEGF were immunohistochemically investigated in tumor samples obtained from 214 gastric cancer patients with all tumor stages. Immunohistochemical analyses for galectin-1 and VEGF expression were performed on formalin-fixed, paraffin-embedded sections of surgical specimens. The relationship between the expression and staining intensity of galectin-1 and VEGF, clinicopathologic variables, and patient survival were analyzed. All patients underwent follow-up until cancer-related death or more than five years after tumor resection. P values < 0.05 were considered statistically significant.RESULTS: Immunohistochemical staining demonstrated that 138 of 214 gastric cancer samples (64.5%) were positive for galectin-1, and 116 out of 214 gastric cancer samples (54.2%) were positive for VEGF. There was a significant association between galectin-1 and VEGF expression; VEGF was detected in 60.1% of galectin-1-positive samples and 43.4% of galectin-1-negative samples (P < 0.05). Galectin-1 expression was associated with tumor size, tumor location, stage, lymph node metastases, and VEGF expression (all P < 0.05). VEGF expression was related to tumor size, stage, and lymph node metastases (all P < 0.05). The 5-year survival rate was 56.6% for galectin-1-positive patients and 69.2% for galectin-1-negative patients, and the prognosis for galectin-1-positive patients was significantly poorer compared with galectin-1-negative patients (χ 2 = 13.880, P = 0.000). The 5-year survival rates for VEGF-positive and VEGF-negative patients were 53.4% and 70.5%, respectively (χ2 = 4.619, P = 0.032). The overall survival rate of patients with both galectin-1 and VEGF overexpression in gastric cancer tissue samples was significantly poorer than other groups (both P < 0.05).CONCLUSION: Galectin-1 expression was positively associated with VEGF expression. Both galectin-1 and VEGF can serve as independent prognostic indicators of poor survival for gastric cancer after gastrectomy.
文摘BACKGROUND:Intestinal microcirculation dysfunction is an important factor that causes poor prognosis in sepsis patients and is an important pathophysiological basis for the occurrence and development of sepsis.DATA RESOURCES:PubMed,Web of Science,and China National Knowledge Infrastructure(CNKI)were searched from inception to August 1,2021.The search was limited to the English language only.Two reviewers independently identified studies related to intestinal microcirculation dysfunction in sepsis.Exclusion criteria were duplicate articles according to multiple search criteria.RESULTS:Fifty articles were included,and most of them were animal studies.These studies reported pathogenesis,including endothelial dysfunction,leukocyte recruitment and adhesion,microthrombus formation,microcirculation hypoperfusion,and redistribution of intestinal wall blood flow.The monitoring methods of intestinal microcirculation were also diverse,including handheld microscopes,intravital microscopy(IVM),laser Doppler blood flow instruments,laser speckle contrast imaging,tissue refl ectance spectrophotometry,biochemical markers of intestinal ischemia,and histopathological examination.In view of the related pathogenesis of intestinal microcirculation disorder in sepsis,existing studies also have diff erent opinions on its treatment.CONCLUSIONS:Limited by monitoring,there are few clinical studies on intestinal microcirculation dysfunction in sepsis.Related research mainly focuses on basic research,but some progress has also been made.Therefore,this review may provide a reference for future research on intestinal microcirculation dysfunction in sepsis.
基金supported by the National Nature Science Foundation of China(Nos.11875191,11890714,11925502,11935001,and 11961141003)the Strategic Priority Research Program(No.CAS XDB1602)。
文摘With the development of laser technologies,nuclear reactions can happen in high-temperature plasma environments induced by lasers and have attracted a lot of attention from different physical disciplines.However,studies on nuclear reactions in plasma are still limited by detecting technologies.This is mainly due to the fact that extremely high electromagnetic pulses(EMPs)can also be induced when high-intensity lasers hit targets to induce plasma,and then cause dysfunction of many types of traditional detectors.Therefore,new particle detecting technologies are highly needed.In this paper,we report a recently developed gated fiber detector which can be used in harsh EMP environments.In this prototype detector,scintillating photons are coupled by fiber and then transferred to a gated photomultiplier tube which is located far away from the EMP source and shielded well.With those measures,the EMPs can be avoided which may result that the device has the capability to identify a single event of nuclear reaction products generated in laser-induced plasma from noise EMP backgrounds.This new type of detector can be widely used as a time-of-flight(TOF)detector in high-intensity laser nuclear physics experiments for detecting neutrons,photons,and other charged particles.
基金supported by the 2018 Shaoguan City Science and Technology Plan Project:Special Project of Industry-University-Research Cooperation(no.2018CS11919)2019 Guangdong Province Special Fund for Science and Technology(‘Big project+task list’)Project:Ecological Cultivation and Sustainable Utilization of Danxia Dendrobium officinale,a rare Southern Medicine in Guangdong Province(no.2019gdskjzxzj-zt3-2)+2 种基金Fundamental Research Project of Shenzhen,China(JCYJ20170817105300166)National Key Research and Development Program of China(no.2018YFD1000401)Key Laboratory of National Forestry and Grassland Administration for Orchid Conservation and Utilization Construction Funds(nos.115/118990050,115/KJG18016A)awarded to Z.-J.L.
文摘Flavonoids,which are a diverse class of phytonutrients,are used by organisms to respond to nearly all abiotic stresses and are beneficial for human health.Glycosyltransferase,used during the last step of flavonoid biosynthesis,is important in flavonoid enrichment.However,little is known about glycosyltransferase in the orchid Dendrobium catenatum(D.officinale).In this study,we isolated a novel C-glycosyltransferase(designated DcaCGT)from the orchid D.catenatum by identifying and analyzing 82 putative genes in the GT1 family.DcaCGT could specifically catalyze not only di-C-glycosylation but also O-glycosylation.Apart from the normal function of catalyzing 2-hydroxynaringenin and phloretin to the respective di-C-glycosides,DcaCGT also catalyzes apigenin to cosmosiin.Targeted metabolic profiling of the substrates(2-hydroxynaringenin,phloretin,and apigenin)and products(vitexin,isovitexin,vicenin-2,nothofagin,3’,5’-di-C-glucosylphloretin,and cosmosiin)in different tissues showed that vicenin-2 was the most abundant product of this novel enzyme.Cosmosiin was detected in flowers and flower buds.We also established that DcaCGT functions expanded throughout the evolution of D.catenatum.Residual OGT activity may help D.catenatum resist drought stress.Our study illustrates the function,origin,and differentiation of DcaCGT and provides insights into glycosylation and molecular propagation processes,which can be used to improve the production of flavonoids by the cultivated medicinal plant D.catenatum.
基金This study was supported by a grant from National Natural Science Foundation of China (81871600)
文摘BACKGROUND:Sepsis-induced liver injury is a fatal complication of sepsis.Trichostatin A(TSA)regulates inflammation and autophagy in some human diseases,and forkhead box O3a(FoxO3a)has been shown to regulate autophagy.The present study aims to investigate whether TSA exerts its effects on septic liver injury through the FoxO3a/autophagy signaling pathway.METHODS:A sepsis mouse model was constructed by the cecal ligation and puncture(CLP)method,and AML12 cells were pretreated with lipopolysaccharide(LPS)(1μg/mL)to establish a sepsis cell model.Forty mice were divided into four groups,namely control group,TSA group,CLP group,and CLP+TSA group,with 10 mice in each group.Cells were divided into control group,TSA group,LPS group,and LPS+TSA group.Hematoxylin-eosin(H&E)staining and biochemical methods were used to evaluate liver tissue injury.Enzyme-linked immunosorbent assay(ELISA)was applied to detect the expression of proinflammatory cytokines,and Western blotting and immunofluorescence were used to measure autophagy-related protein expression.RESULTS:Compared with the CLP group(mice),the proinflammatory cytokines(interleukin-β[IL-β]2,665.27±324.90 pg/mL to 2,080.26±373.66 pg/mL;interleukin-6[IL-6]399.01±60.98 pg/mL to 221.90±46.89 pg/mL)and the hepatocyte injury markers(aspartate transaminase[AST]from 198.18±27.07 U/L to 128.42±20.55 U/L;alanine aminotransferase[ALT]from 634.98±74.10 U/L to 478.60±32.56 U/L)were notably decreased after TSA intervention.Moreover,LC3 II and FoxO3a showed an obvious increase and P62 showed an obvious decrease in the CLP+TSA group.Cell experiment results showed the similar trend.After Fox O3a gene was knocked down in AML12 cells,the promotion of autophagy and the improvement of liver enzyme index and inflammation by TSA were weakened.CONCLUSION:TSA may improve the inflammatory response and liver injury in septic mice through Fox O3a/autophagy.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB16)the Strategic Priority Research Program of the CAS(No.XDB34030000)。
文摘The isomer ^(229m)Th is the most promising candidate for clocks based on the nuclear transition because it has the lowest excitation energy of only 8.10±0.17 eV.Various experiments and theories have focused on methods of triggering the transition between the ground state and isomeric state,among which the electronic bridge(EB)is one of the most efficient.In this paper,we propose a new electronic bridge mechanism via two-photon excitation based on quantum optics for a two-level nuclear quantum system.The long-lived 7 s1/2 electronic shell state of^(229m)Th^(3+),with a lifetime of approximately 0.6 s,is chosen as the initial state and the atomic shells(7 s-10 s)could be achieved as virtual states in a two-photon process.When the virtual states return to the initial state 7 s1/2,there is a chance of triggering the nucleus 229Th^(3+),to its isomeric state ^(229m)Th ^(3+),via EB.Two lasers at moderate intensity((10^(10)-10^(14))W/m^(2)),with photon energies near the optical range,are expected to populate the isomer at a saturated rate of approximately 10^(9) s^(-1),which is much higher than that due to other mechanisms.We believe that this twophoton EB scheme can help in the development of nuclear clocks and deserves verification via a series of experiments with ordinary lasers in laboratories.
基金funded by The National Key Research and Development Program of China(Nos.2018YFD1000401 and 2018YFD1000400)the Natural Science Foundation of Guangdong Province(No.2017A030312004)the Science and Technology Plan Project of Shenzhen(No.JCYJ20170817151501595).
文摘Cymbidium,which includes approximately 80 species,is one of the most ornamental and cultivated orchid genera.However,a lack of markers and sparse sampling have posed great challenges to resolving the phylogenetic relationships within the genus.In the present study,we reconstructed the phylogenetic relationships by utilizing one nuclear DNA(nrITS)and seven plastid genes(rbcL,trnS,trnG,matK,trnL,psbA,and atpI)from 70 species(varieties)in Cymbidium.We also examined the occurrence of phylogenetic conflict between nuclear(nrITS)and plastid loci and investigated how phylogenetic conflict bears on taxonomic classification within the genus.We found that phylogenetic conflict and low support values may be explained by hybridization and a lack of informative characteristics.Our results do not support previous classification of the subgenera and sections within Cymbidium.Discordance between gene trees and network analysis indicate that reticulate evolution occurred in the genus Cymbidium.Overall,our study indicates that Cymbidium has undergone a complex evolution.
基金This project was supported by the Guangdong Innovation Research Team Fund(2014ZT05S078)National Natural Science Foundation of China(grants 31571252 and 31772322)+7 种基金Guangdong Special Support Program for Young Talents in Innovation Research of Science and Technology(2019TQ05N940)Shenzhen Peacock Grant(827/000189)Science and Technology Program of Guangdong Province,China(2019B121202006)Program of Forestry Administration of Guangdong Province(E036011002)Department for Wildlife and Forest Plant Protection of the National Forest and Grassland Administration(2019073010)National Key Research and Development Program of China(No.2018YFD1000400)Special Research Foundation of Hebei Agricultural University(YJ201848)Natural Science Foundation of Hebei Province(C2019204295).
文摘As one of the largest families of angiosperms,the Orchidaceae family is diverse.Dendrobium represents the second largest genus of the Orchidaceae.However,an assembled high-quality genome of species in this genus is lacking.Here,we report a chromosome-scale reference genome of Dendrobium chrysotoxum,an important ornamental and medicinal orchid species.The assembled genome size of D.chrysotoxum was 1.37 Gb,with a contig N50 value of 1.54 Mb.Of the sequences,95.75%were anchored to 19 pseudochromosomes.There were 30,044 genes predicted in the D.chrysotoxum genome.Two whole-genome polyploidization events occurred in D.chrysotoxum.In terms of the second event,whole-genome duplication(WGD)was also found to have occurred in other Orchidaceae members,which diverged mainly via gene loss immediately after the WGD event occurred;the first duplication was found to have occurred in most monocots(tau event).We identified sugar transporter(SWEET)gene family expansion,which might be related to the abundant medicinal compounds and fleshy stems of D.chrysotoxum.MADS-box genes were identified in D.chrysotoxum,as well as members of TPS and Hsp90 gene families,which are associated with resistance,which may contribute to the adaptive evolution of orchids.We also investigated the interplay among carotenoid,ABA,and ethylene biosynthesis in D.chrysotoxum to elucidate the regulatory mechanisms of the short flowering period of orchids with yellow flowers.The reference D.chrysotoxum genome will provide important insights for further research on medicinal active ingredients and breeding and enhances the understanding of orchid evolution.
基金financially supported by the National Natural Science Foundation of China (Nos. 51571058 and 51871048)the Open Foundation of Key Laboratory for Anisotropy and Texture of Materials, Ministry of Education, Northeastern University, China (No. ATM20170001)
文摘To explore the specimen size effect of mechanical behavior of ultrafine-grained(UFG)materials with different structures,UFG Al sheets processed by equal channel angular pressing(ECAP)were selected as target materials and the dependency of tensile behavior on sheet thickness(t)was systematically investigated.The strength and ductility of ECAPed UFG Al sheets were improved synchronously as t increased from 0.2 to 0.7 mm,and then no apparent change occurred when t reached to 0.7 and 1.0 mm.The corresponding microstructure evolved from dislocation networks in equiaxed grains into the walls and subgrains and finally into the dominated cells in elongated grains or subgrains.Meanwhile,dense shear lines(SLs)and shear bands(SBs)were clearly observed and microvoids and cracks were initiated along SBs with the increase of t.These observations indicated that the plastic deformation of UFG Al sheets was jointly controlled by shear banding,dislocation sliding,and grain-boundary sliding.Furthermore,the propagation of SBs became difficult as t increased.Finally,the obtained results were discussed and compared with those of annealed UFG Al and UFG Cu.
基金supported in part by the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB160203)the National Natural Science Foundation of China(Nos.11875311 and 11421505).
文摘Investigating deuteron–deuteron(DD)fusion reactions in a plasma environment similar to the early stages of the Big Bang is an important topic in nuclear astrophysics.In this study,we experimentally investigated such reactions,using eight laser beams with the third harmonic impacting on a deuterated polyethylene target at the ShenGuang-II Upgrade laser facility.This work focused on the application of range-filter(RF)spectrometers,assembled from a 70 lm aluminum filter and two CR-39 nuclear track detectors,to measure the yields of primary DD-protons.Based on the track diameter calibration results of 3 MeV protons used to diagnose the tracks on the RF spectrometers,an approximate primary DD-proton yield of(8.5±1.7)×10^6 was obtained,consistent with the yields from similar laser facilities worldwide.This indicates that the RF spectrometer is an effective way to measure primary DD-protons.However,due to the low yields of D^3He-protons and its small track diameter,CR-39 detectors were unable to distinguish it from the background spots.Using other accurate detectors may help to measure these rare events.
基金supported in part by the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB160203)the National Natural Science Foundation of China(Nos.11875311,11421505,and 11475245)
文摘Charged particle diagnosis is an important aspect of laser–plasma experiments conducted at super-intense laser facilities. In recent years, Columbia Resin #39 (CR- 39) detectors have been widely employed for detecting charged particles in laser–plasma experiments. This is because the CR-39 polymer does not respond to electromagnetic pulses or X-rays. This study presents a method for calibrating the relationship between particle energy and track diameter in a CR-39 detector (TasTrak■) using 3-8 MeV protons, 6-30 MeV carbon ions, and 1–5 MeV alpha particles. The particle tracks were compared under the manufacturer’s recommended etching conditions of 6.25 mol/l NaOH at 98℃ and under the widely adopted experimental conditions of 6.25 mol/l NaOH at 70℃. The results show that if the NaOH solution concentration is 6.25 mol/l, then the temperature of 70℃is more suitable for etching proton tracks than 98℃ and employing a temperature of 98 ℃ to etch alpha-particle and carbon-ion tracks can significantly reduce the etching time. Moreover, this result implies that C3+ ion or alpha-particle tracks can be distinguished from proton tracks with energy above 3 MeV by controlling the etching time. This calibration method for the CR-39 detector can be applied to the diagnosis of reaction products in laser–plasma experiments.
基金financially supported by the National Natural Science Foundation of China (Nos. 51571058, 51271054 and 51231002)the Open Foundation of Key Laboratory for Anisotropy and Texture of Materials of Ministry of Education, Northeastern University, China (No. ATM20170001)
文摘To explore the influence of cyclic pre-deformation on the mechanical behavior of ultrafine-grained（UFG）materials with a high stacking fault energy（SFE）,UFG Al processed by equal-channel angular pressing（ECAP）was selected as a target material and its tensile behavior at different pre-cyclic levels D（D=N_i/N_f,where N_i and N_f are the applied cycles and fatigue life at a constant stress amplitude of 50 MPa,respectively）along with the corresponding microstructures and deformation features were systematically studied.The cyclic pre-deformation treatment on the ECAPed UFG Al led to a decrease in flow stress,and a stress quasi-plateau stage was observed after yielding for all of the different-state UFG Al samples.The yield strengths_（YS）,ultimate tensile strengths_（UTS）,and uniform straineexhibited a strong dependence on D when D≤20%;however,when D was in the range from 20%to 50%,no obvious change in mechanical properties was observed.The micro-mechanism for the effect of cyclic pre-deformation on the tensile properties of the ECAPed UFG Al was revealed and compared with that of ECAPed UFG Cu through the observations of deformation features and microstructures.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11934010,U1801661,U1930402,and 11847087)the National Key Research and Development Program of China(Grant No.2016YFA0301200)。
文摘We study the dissipative quantum phase transition(QPT)in a biased Tavis–Cummings model consisting of an ensemble of two-level systems(TLSs)interacting with a cavity mode,where the TLSs are pumped by a drive field.In our proposal,we use a dissipative TLS ensemble and an active cavity with effective gain.In the weak drive-field limit,the QPT can occur under the combined actions of the loss and gain of the system.Owing to the active cavity,the QPT behavior can be much differentiated even for a finite strength of the drive field on the TLS ensemble.Also,we propose to implement our scheme based on the dissipative nitrogen-vacancy(NV)centers coupled to an active optical cavity made from the gainmedium-doped silica.Furthermore,we show that the QPT can be measured by probing the transmission spectrum of the cavity embedding the ensemble of the NV centers.
基金partially supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(Nos.XDB16 and XDPB09)the National Natural Science Foundation of China(Nos.11890714 and 11421505)the Key Research Program of Frontier Sciences of the CAS(No.QYZDJ-SSW-SLH002)
文摘The neutron yield in the12C(d,n)13N reaction and the proton yield in the12C(d,p)13C reaction have been measured using deuteron beams of energies 0.6-3 MeV.The deuteron beam is delivered from a 4-MeV electrostatic accelerator and bombarded on a thick carbon target.The neutrons are detected at 0°,24°,and 48°and the protons at135°in the laboratory frame.Further,the ratio of the neutron yield to the proton yield was calculated.This can be used to effectively recognize the resonances.The resonances are found at 1.4 MeV,1.7 MeV,and 2.5 MeV in the12C(d,p)13C reaction,and at 1.6 MeV and 2.7 MeV in the12C(d,n)13N reaction.The proposed method provides a way to reduce systematic uncertainty and helps confirm more resonances in compound nuclei.
基金Chinese Academy of Medical Sciences Innovation Fund for Medical Sciences(No.2019-I2M-5-023)Hainan Provincial Science and Technology Major Project(No.ZDKJ201804)+2 种基金National Natural Science Foundation of China(No.81871611)National Natural Science Foundation of China(No.81760352)Project of Hainan Provincial Department of Education(No.Hnjg2019ZD-16)
文摘1.Introduction Sudden cardiac death(SCD)refers to sudden death due to a variety of cardiac causes.It is manifested as a sudden loss of consciousness,cardiac arrest,and respiratory arrest and generally shows early symptoms that are atypical and not easily detected[1].According to a recent study,nearly 544000 patients suffer from SCD every year in China[2].
