Coordinated responses of leaf and nodule traits contribute to the accumulation of N in relay intercropped soybean

Maize(Zea mays L.)-soybean(Glycine max L.Merr.)relay intercropping provides a way to enhance land productivity.However,the late-planted soybean suffers from shading by the maize.After maize harvest,how the recovery growth influences the leaf and nodule traits remains unclear.A three-year field experiment was conducted to evaluate the effects of genotypes,i.e.,supernodulating(nts1007),Nandou 12(ND12),and Guixia 3(GX3),and crop configurations,i.e.,the interspecific row spacing of 45(I45),60(I60),75 cm(I75),and sole soybean(SS),on soybean recovery growth and N fixation.The results showed that intercropping reduced the soybean total leaf area(LA)by reducing both the leaf number(LN)and unit leaflet area(LUA),and it reduced the nodule dry weight(NW)by reducing both the nodule number(NN)and nodule diameter(ND)compared with the SS.The correlation and principal component analysis(PCA)indicated a co-variability of the leaf and nodule traits in response to the genotype and crop configuration interactions.During the recovery growth stages,the compensatory growth promoted soybean growth to reduce the gaps of leaf and nodule traits between intercropping and SS.The relative growth rates of ureide(RGR_U)and nitrogen(RGR_N)accumulation were higher in intercropping than in SS.Intercropping achieved more significant sucrose and starch contents compared with SS.ND12 and GX3 showed more robust compensatory growth than nts1007 in intercropping.Although the recovery growth of relay intercropping soybean improved biomass and nitrogen accumulation,ND12 gained a more significant partial land equivalent ratio(pLER)than GX3.The I60 treatment achieved more robust compensation effects on biomass and N accumulation than the other configurations.Meanwhile,I60 showed a higher nodule sucrose content and greater shoot ureide and N accumulation than SS.Finally,intercropping ND12 with maize using an interspecific row spacing of 60 cm was optimal for both yield advantage and N accumulation.

Relay-intercropping soybean with maize maintains soil fertility and increases nitrogen recovery efficiency by reducing nitrogen input

Optimized nitrogen(N)management can increase N-use efficiency in intercropping systems.Legume-nonlegume intercropping systems can reduce N input by exploiting biological N fixation by legumes.Measurement of N utilization can help in dissecting the mechanisms underlying N uptake and utilization in legume-nonlegume intercropping systems.An experiment was performed with three planting patterns:monoculture maize(MM),monoculture soybean(SS),and maize-soybean relay intercropping(IMS),and three N application levels:zero N(NN),reduced N(RN),and conventional N(CN)to investigate crop N uptake and utilization characteristics.N recovery efficiency and 15N recovery rate of crops were higher under RN than under CN,and those under RN were higher under intercropping than under the corresponding monocultures.Compared with MM,IMS showed a lower soil N-dependent rate(SNDR)in 2012.However,the SNDR of MM rapidly declined from 86.8%in 2012 to 49.4%in 2014,whereas that of IMS declined slowly from 75.4%in 2012 to 69.4%in 2014.The interspecific N competition rate(NCRms)was higher under RN than under CN,and increased yearly.Soybean nodule dry weight and nitrogenase activities were respectively 34.2%and 12.5%higher under intercropping than in monoculture at the beginning seed stage.The amount(Ndfa)and ratio(%Ndfa)of soybean N2 fixation were significantly greater under IS than under SS.In conclusion,N fertilizer was more efficiently used under RN than under CN;in particular,the relay intercropping system promoted N fertilizer utilization in comparison with the corresponding monocultures.An intercropping system helps to maintain soil fertility because interspecific N competition promotes biological N fixation by soybean by reducing N input.Thus,a maize-soybean relay intercropping system with reduced N application is sustainable and environmentally friendly.

Mechanisms responsible for the effect of median nerve electrical stimulation on traumatic brain injuryinduced coma: orexin-A-mediated N-methyl-Daspartate receptor subunit NR1 upregulation

Electrical stimulation of the median nerve is a noninvasive technique that facilitates awakening from coma. In rats with traumatic brain injury-induced coma, median nerve stimulation markedly enhances prefrontal cortex expression of orexin-A and its receptor, orexin receptor 1. To further understand the mechanism underlying wakefulness mediated by electrical stimulation of the median nerve, we evaluated its effects on the expression of the N-methyl-D-aspartate receptor subunit NR1 in the prefrontal cortex in rat models of traumatic brain injury-induced coma, using immunohistochemistry and western blot assays. In rats with traumatic brain injury, NR1 expression increased with time after injury. Rats that underwent electrical stimulation of the median nerve（30 Hz, 0.5 ms, 1.0 m A for 15 minutes） showed elevated NR1 expression and greater recovery of consciousness than those without stimulation. These effects were reduced by intracerebroventricular injection of the orexin receptor 1 antagonist SB334867. Our results indicate that electrical stimulation of the median nerve promotes recovery from traumatic brain injury-induced coma by increasing prefrontal cortex NR1 expression via an orexin-A-mediated pathway.

Clinical characteristics of 290 foreign-imported cases infected with SARS-CoV-2 in Chengdu, China

Objective:To analyze the epidemiological and clinical characteristics of foreign-imported patients infected with SARS-CoV-2 in Chengdu City.Methods:A total of 290 foreign-imported patients infected with SARS-CoV-2 and discharged from Public Health Clinical Center of Chengdu were included in our study,they were divided into asymptomatic infection group(131 cases)and confirmed cases group(159 cases)in order to compare the epidemiology,clinical characteristics and laboratory tests between two groups.Multi-factor logistic regression analysis was used to investigate the influence factors of becoming a dominant infection after infected with SARS-CoV-2.Results:Among the 290 cases aged from 2 months to 68 years old,83.4%were males,62.1%came from Asia,and 43.8%were complicated with fatty liver disease,the age group of 14-49 years old had the largest number(247 cases).80.5%confirmed case group cases were general type,there was only 1 severe patient.Hospital stays in asymptomatic infection group was shorter than that in confirmed cases group,lymphocyte count,CD4+T count,CD8+T count,CD4+T/CD8+T creatine kinase in two groups half a month after discharge were relatively lower than those on admission,and alanine aminotransferase,aspartate aminotransferase,albumin,lactate dehydrogenase,creatine kinase isoenzyme were relatively higher than those on admission(P<0.05).Logistic regression analysis showed that increased age,decreased lymphocyte count on admission and increased lactate dehydrogenase on admission were associated with dominant infection.Chest CT of 13 general type cases indicated an increase in lesions compared with that at discharge and 3 of them had re-detectable positive RNA test.Conclusion:The majority of foreign-imported cases in Chengdu are mainly from Asia,fewer of them are severe patients.In the early stage of recovery,some SARS-CoV-2 infected patients still have intermittent viral replication.Early isolation and early treatment of imported patients is not only conducive to epidemic prevention and control,but also may change the natural course of the disease.

Characterization of local chemical ordering and deformation behavior in high entropy alloys by transmission electron microscopy

Short-range ordering(SRO)is one of the most important structural features of high entropy alloys(HEAs).However,the chemical and structural analyses of SROs are very difficult due to their small size,complexed compositions,and varied locations.Transmission electron microscopy(TEM)as well as its aberration correction techniques are powerful for characterizing SROs in these compositionally complex alloys.In this short communication,we summarized recent progresses regarding characterization of SROs using TEM in the field of HEAs.By using advanced TEM techniques,not only the existence of SROs was confirmed,but also the effect of SROs on the deformation mechanism was clarified.Moreover,the perspective related to application of TEM techniques in HEAs are also discussed.

血清sICAM-1、VEGF在缺血性脑卒中致血管性痴呆患者中的表达及临床意义

目的观察血清可溶性细胞间黏附分子-1(sICAM-1)、血管内皮生长因子(VEGF)在缺血性脑卒中致血管性痴呆(VD)患者中的表达及临床意义。方法回顾性分析2020年1月—2021年6月南京中医药大学连云港附属医院收治的112例缺血性脑卒中患者的临床资料,发生VD的31例缺血性脑卒中患者为VD组,其余81例为非VD组。另选取该院同期体检的健康人员55例为健康组。比较3组血清sICAM-1、VEGF水平;比较VD组和非VD组的临床资料,采用多因素逐步Logistic回归分析缺血性脑卒中后发生VD的影响因素;绘制受试者工作特征(ROC)曲线分析血清sICAM-1、VEGF单独及联合检测对缺血性脑卒中后发生VD的预测价值。结果与健康组比较,非VD组、VD组血清sICAM-1、VEGF水平升高(P<0.05);与非VD组比较,VD组血清sICAM-1水平升高(P<0.05),血清VEGF水平降低(P<0.05)。与非VD组比较,VD组吸烟占比、高血压及NIHSS评分升高(P<0.05),两组的年龄、性别构成、BMI、饮酒、VD家族史、高盐饮食、高脂血症、糖尿病、冠心病、多发性脑梗死、脑梗死病史、脑白质疏松、脑梗死部位、梗死范围、职业类型比较,差异无统计学意义(P>0.05)。多因素逐步Logistic回归分析显示,吸烟[OR=1.881(95%CI:1.521,2.242)]、高血压[OR=7.043(95%CI:4.123,9.963)]、NIHSS评分[OR=4.674(95%CI:2.379,6.969)]、额叶脑梗死[OR=2.396(95%CI:1.985,2.808)]、血清sICAM-1水平[OR=4.591(95%CI:2.379,6.802)]、血清VEGF水平[OR=4.889(95%CI:2.147,7.631)]均是缺血性脑卒中后发生VD的危险因素(P<0.05);ROC曲线结果显示,血清sICAM-1、VEGF预测缺血性脑卒中后发生VD的最佳截断值为365.41 ng/L和216.52 pg/mL,两者单独及联合检测缺血性脑卒中后发生VD的AUC分别为0.754、0.793和0.868。结论在缺血性脑卒中致VD患者中血清sICAM-1高表达,VEGF低表达,两者单独及联合检测对缺血性脑卒中后VD的发生具有较高的预测价值。

Two-Phase Flow in Porous Electrodes of Proton Exchange Membrane Fuel Cell

Water management in porous electrodes bears significance due to its strong potential in determining the performance of proton exchange membrane fuel cell.In terms of porous electrodes,internal water distribution and removal process have extensively attracted attention in both experimental and numerical studies.However,the structural difference among the catalyst layer(CL),microporous layer(MPL),and gas diffusion layer(GDL)leads to significant challenges in studying the two-phase flow behavior.Given the different porosities and pore scales of the CL,MPL,and GDL,the model scales in simulating each component are inconsistent.This review emphasizes the numerical simulation related to porous electrodes in the water transport process and evaluates the effectiveness and weakness of the conventional methods used during the investigation.The limitations of existing models include the following:(i)The reconstruction of geometric models is difficult to achieve when using the real characteristics of the components;(ii)the computational domain size is limited due to massive computational loads in three-dimensional(3 D)simulations;(iii)numerical associations among 3 D models are lacking because of the separate studies for each component;(iv)the effects of vapor condensation and heat transfer on the two-phase flow are disregarded;(v)compressive deformation during assembly and vibration in road conditions should be considered in two-phase flow studies given the real operating conditions.Therefore,this review is aimed at critical research gaps which need further investigation.Insightful potential research directions are also suggested for future improvements.

Pore-Scale Investigation of Coupled Two-Phase and Reactive Transport in the Cathode Electrode of Proton Exchange Membrane Fuel Cells

A three-dimensional multicomponent multiphase lattice Boltzmann model(LBM)is established to model the coupled two-phase and reactive transport phenomena in the cathode electrode of proton exchange membrane fuel cells.The gas diff usion layer(GDL)and microporous layer(MPL)are stochastically reconstructed with the inside dynamic distribution of oxygen and liquid water resolved,and the catalyst layer is simplifi ed as a superthin layer to address the electrochemical reaction,which provides a clear description of the fl ooding eff ect on mass transport and performance.Diff erent kinds of electrodes are reconstructed to determine the optimum porosity and structure design of the GDL and MPL by comparing the transport resistance and per-formance under the fl ooding condition.The simulation results show that gradient porosity GDL helps to increase the reactive area and average concentration under fl ooding.The presence of the MPL ensures the oxygen transport space and reaction area because liquid water cannot transport through micropores.Moreover,the MPL helps in the uniform distribution of oxygen for an effi cient in-plane transport capacity.Crack and perforation structures can accelerate the water transport in the assembly.The systematic perforation design yields the best performance under fl ooding by separating the transport of liquid water and oxygen.

Effects of Qidi Tangshen granules and their separate prescriptions on podocytes in mice with diabetic nephropathy

Objective:Previous studies have found that Qidi Tangshen granules(QDTS),a combination therapy of supplementing essence(Tianjing,TJ)and unblocking the collaterals(Tongluo,TL),can reduce kidney damage in db/db mice.This study aimed to explore the effect of QDTS and their separate prescriptions on podocytes in mice with diabetic nephropathy.Methods:The db/db mice were used in this experiment as an animal model,while wild-type C57BL/6J mice were used as normal controls.At the age of 12 weeks,the db/db mice were randomly divided into 5 groups(db/db,db/dbþvalsartan,db/dbþQDTS,db/dbþTJ and db/dbþTL).The urine albumin excretion ratio(UAE)was measured by enzyme-linked immunosorbent assay before and after the intervention.The ultrastructure of the kidney podocytes was observed by transmission electron microscopy.The protein expression levels of nephrin and desmin were detected by immunohistochemistry.Results:QDTS and their separate prescriptions significantly decreased the UAE and attenuated the renal pathological injury.QDTS and their separate prescriptions also reduced the fusion rate of the foot processes and increased the expression of nephrin protein.In contrast,QDTS and their separate prescriptions(TJ and TL)reduced the expression level of desmin protein.Conclusion:QDTS and their separate prescriptions might reduce diabetes-induced renal injury by reducing podocyte damage.The therapeutic effect of QDTS was more pronounced than TJ and TL.

Research Performance Assessment Based on T-Indicator

A novel indicator named after Tianjin University (TJU)-T-indicator-was investigated as an effective supplement of established Article Assessment System of Tianjin University, aiming to correct differences among fields. Based on normalized citation counts, T-indicator could give the order of research performance of researchers or groups in different disciplines. Weighted citation analysis was also introduced in this method to judge the contribution of researchers to their research outcomes. A given example was used to thoroughly discuss this evaluation method, via the application of derivative indices, including Tyear, Taverage, Ttotal and weighted-Ttotal.

Experimental Study on the Selection of Different Drugs Protecting from Rhizoctonia solani

In order to achieve ideal prevention and treatment effect of maize sheath blight,24%Jinggangmycin A+0.5%adjuvant,24%Jinggangmycin A,Bacillus subtilis and Jinggangmycin+B.subtilis were selected.Each agent was prepared into a 500 times dilution,and the control effect was tested by two times of spray application.The results showed that the disease index of maize sheath blight could be reduced by all the treatments,which were significantly different from that of the control group,but the differences between the treatments were not significant.Jinggangmycin+B.subtilis and B.subtilis had the best control effects.Therefore,their use for preventing maize sheath blight could reduce chemical residues of maize,and avoid environmental pollution.

Automated detection of myopic maculopathy from color fundus photographs using deep convolutional neural networks

Background:Myopic maculopathy(MM)has become a major cause of visual impairment and blindness worldwide,especially in East Asian countries.Deep learning approaches such as deep convolutional neural networks(DCNN)have been successfully applied to identify some common retinal diseases and show great potential for the intelligent analysis of MM.This study aimed to build a reliable approach for automated detection of MM from retinal fundus images using DCNN models.Methods:A dual-stream DCNN(DCNN-DS)model that perceives features from both original images and corresponding processed images by color histogram distribution optimization method was designed for classification of no MM,tessellated fundus(TF),and pathologic myopia(PM).A total of 36,515 gradable images from four hospitals were used for DCNN model development,and 14,986 gradable images from the other two hospitals for external testing.We also compared the performance of the DCNN-DS model and four ophthalmologists on 3000 randomly sampledfundus images.Results:The DCNN-DS model achieved sensitivities of 93.3%and 91.0%,specificities of 99.6%and 98.7%,areas under the receiver operating characteristic curves(AUCs)of 0.998 and 0.994 for detecting PM,whereas sensitivities of 98.8%and 92.8%,specificities of 95.6%and 94.1%,AUCs of 0.986 and 0.970 for detecting TF in two external testing datasets.In the sampled testing dataset,the sensitivities of four ophthalmologists ranged from 88.3%to 95.8%and 81.1%to 89.1%,and the specificities ranged from 95.9%to 99.2%and 77.8%to 97.3%for detecting PM and TF,respectively.Meanwhile,the DCNN-DS model achieved sensitivities of 90.8%and 97.9%and specificities of 99.1%and 94.0%for detecting PMand T,respectively.Conclusions:The proposed DCNN-DS approach demonstrated reliable performance with high sensitivity,specificity,and AUC to classify different MM levels on fundus photographs sourced from clinics.It can help identify MM automatically among the large myopic groups and show great potential for real-life applications.

The effect of applied voltages on the structure,apatite-inducing ability and antibacterial ability of micro arc oxidation coating formed on titanium surface

The micro arc oxidation(MAO)coatings with different concentrations of Ca,P and Zn elements are successfully formed on the titanium substrate at the different applied voltages.After MAO treatment,the MAO coating exhibits the porous surface structure and composed of anatase and rutile TiO2 phases.Meanwhile,the average size and density of micro-pores on the MAO coatings have been modified via the adjusting the applied voltages.In addition,the contents of the incorporated elements such as Zn,Ca and P elements in the MAO coatings have been optimized.The bonding strength test results reveal that the MAO coating shows higher bonding strength,which is up to 45±5 MPa.Compared to the pure Ti plate,the MAO coating formed at 350 and 400 V show good apatite-inducing ability.Meanwhile,the MAO coating containing Zn,Ca and P elements have better antibacterial ability for E.coli and S.aureus.Thus,the incorporation of Zn,Ca and P elements was an effective method to improve the antibacterial ability.Moreover,the concentrations of Zn,Ca and P elements could be adjusted with the changing of the applied voltages.As a result,the enhancement of the antibacterial ability on the MAO coating surfaces was depended on the comprehensive effect of the incorporated elements and the surface property of MAO coatings.

Efficient removal of chlorophenols from water with a magnetic reduced graphene oxide composite

A magnetic reduced graphene oxide composite(MRGO) was successfully prepared by a simple and green method. MRGO was then used as an adsorbent and found to exhibit enhanced removal efficiency for various chlorophenols(CPs) from water compared with its precursors, graphene oxide(GO) and reduced graphene oxide. The CPs were o-chlorophenol, p-chlorophenol, 2,4-dichlorophenol, and 2,4,6-trichlorophenol. Among them, 2,4,6-trichlorophenol, which exhibited the lowest water solubility and highest molecular weight, most easily bound to MRGO. The preferential interactions between MRGO and CPs were hydrophobic interactions(?-? stacking and hydrophobic effect). This result was confirmed by the equilibrium adsorption behavior in which isotherms were all well described by Freudlich model, indicating heterogeneous and multilayer adsorption. Therefore, CP adsorption was more favored under neutral and acidic conditions, and the decreased removal efficiency of MRGO at higher p H levels was due to the improved hydrophilicity of CPs for deprotonation effect. Moreover, MRGO showed fast removal of each CP, achieving adsorption equilibrium within 10.0 min, presented efficient separation from water under an external magnetic field, and was easily regenerated using dilute Na OH aqueous solution after reaching saturated adsorption. Adsorption capacity of the regenerated MRGO had almost no loss until after five cycles. In summary, MRGO was an efficient adsorbent for the removal of various CPs and had considerable application potential in water treatment.

Review on regulation of MnS in non-qquenched and tempered steel

An overview of the current research status and control methods of MnS in non-quenched and tempered steel was provided.As a low-melting plastic inclusion,the morphology and distribution of MnS were influenced by various production processes.Therefore,control of MnS is a systematic problem that must be integrated into the entire production process.Based on the production process,the factors affecting the morphology and distribution of MnS in steel were introduced.The effects of oxygen activity,manganese,sulfur,and some alloys on MnS inclusion precipitation were summarized,mainly including MnS modification treatment and oxygen-sulfide composite precipitation control.It is believed that MnS precipitates during the solidification process of steel,and controlling the solidification cooling rate could effectively regulate the size and morphology of MnS,avoiding the precipitation of II-MnS.Additionally,by changing the deformation rate,deformation amount,deformation temperature during the hot deformation process,and heating time and temperature during heat treatment,the distribution and morphology of MnS could be improved.Through the fine control of the above process parameters,the number of II-MnS in steel could be effectively reduced,and their morphology could be improved,thereby enhancing the performance of non-quenched and tempered steel and promoting its wider application.Furthermore,applying laboratory research results to industrial production is an important direction for future research efforts in this field.

An in-situ biochar-enhanced anaerobic membrane bioreactor for swine wastewater treatment under various organic loading rates

A biochar-assisted anaerobic membrane bioreactor(BC-AnMBR)was conducted to evaluate the performance in treating swine wastewater with different organic loading rates(OLR)ranging from 0.38 to 1.13 kg-COD/(m3.d).Results indicated that adding spent coffee grounds biochar(SCG-BC)improved the organic removal efficiency compared to the conventional AnMBR,with an overall COD removal rate of>95.01%.Meanwhile,methane production of up to 0.22 LCH4/gCOD with an improvement of 45.45%was achieved under a high OLR of 1.13 kg-COD/(m3.d).Furthermore,the transmembrane pressure(TMP)in the BC-AnMBR system was stable at 4.5 kPa,and no irreversible membrane fouling occurred within 125 days.Microbial community analysis revealed that the addition of SCG-BC increased the relative abundance of autotrophic methanogenic archaea,particularly Methanosarcina(from 0.11%to 11.16%)and Methanothrix(from 16.34%to 24.05%).More importantly,Desulfobacterota and Firmicutes phylum with direct interspecific electron transfer(DIET)capabilities were also enriched with autotrophic methanogens.Analysis of the electron transfer pathway showed that the concentration of c-type cytochromes increased by 38.60%in the presence of SCGBC,and thus facilitated the establishment of DIET and maintained high activity of the elec-tron transfer system even at high OLR.In short,the BC-AnMBR system performs well under various OLR conditions and is stable in the recovery energy system for swine wastewater.

Preparation and characterization of boron-doped corn straw biochar: Fe(Ⅱ) removal equilibrium and kinetics

Nowadays,iron ions as a ubiquitous heavy metal pollutant are gradually concerned and the convenient and quick removal of excessive iron ions in groundwater has become a major challenge for the safety of drinking water.In this study,boron-doped biochar(B-BC)was successfully prepared at various preparation conditions with the addition of boric acid.The as-prepared material has a more developed pore structure and a larger specific surface area(up to 897.97 m2/g).A series of characterization results shows that boric acid effectively activates biochar,and boron atoms are successfully doped on biochar.Compared with the ratio of raw materials,the pyrolysis temperature has a greater influence on the amount of boron doping.Based on Langmuir model,the maximum adsorption capacity of 800 B-BC1:2 at25℃,40℃,55℃ are 50.02 mg/g,95.09 mg/g,132.78 mg/g,respectively.Pseudo-second-order kinetic model can better describe the adsorption process,the adsorption process is mainly chemical adsorption.Chemical complexation,ions exchange,and co-precipitation may be the main mechanisms for Fe2+removal.

High-entropy carbide-nitrides with enhanced toughness and sinterability

High-entropy ceramics (HECs) have attracted much attention due to their huge composition space,unique microstructure,and desirable properties.In contrast to previous studies,which have primarily focused on HECs with one anion,herein,we report a new family of ceramics with both multi-cationic and-anionic structures,i.e.,high-entropy carbide-nitrides (Ti0.33Zr0.33Hf0.33)(C0.5N0.5),(Ti0.25Zr0.25Hf0.25-Nb0.25)(C0.5N0.5) and (Ti0.2Zr0.2Hf0.2Nb0.2Ta0.2)(C0.5N0.5).These as-synthesized HECs are mainly comprised of a face-centered cubic solid-solution phase accompanied by minor inevitable oxide phases.The formation mechanism of the solid-solution phase is discussed in terms of the lattice size difference and thermodynamic competition between configurational entropy and mixing enthalpy.It is found that the increment in the configurational entropy can effectively lower the sintering temperature and increase the fracture toughness.Particularly,the newly developed (Ti0.2Zr0.2Hf0.2Nb0.2Ta0.2)(C0.5N0.5) exhibits a decent fracture toughness of 8.4 MPa m1/2and a low sintering temperature of 1750°C,making it promising for ultra-high temperature applications.Our work not only enriches knowledge regarding the HECs categories,but also opens a new pathway for developing HECs with multi-cationic and-anionic structures.

单分子测序技术在肿瘤诊断中的应用研究进展

肿瘤的发生发展通常与多个基因的遗传突变、表达异常有关,全面深入地分析肿瘤基因组、转录组及表观遗传组学对于快速剖析疾病特定基因簇及修饰位点至关重要。之前,研究者们主要采用第二代测序技术进行有效信息的挖掘,然而随着研究的不断深入,第二代测序技术表现出诸如序列拼接困难、低丰度难以检出等缺点。因此,单分子测序技术以其独特的优势应运而生,文中主要对单分子测序技术在几种常见肿瘤中的研究现状进行了综述,并展望了其在临床诊断中的应用前景。

Local chemical ordering and its impact on radiation damage behavior of multi-principal element alloys

Multi-principal element alloys(MPEAs)have attracted much attention as future nuclear materials due to their extraordinary radiation resistances.In this work,we have elucidated the development of local chemical orderings(LCOs)and their influences on radiation damage behavior in the typical CrFeNi MPEA by hybrid-molecular dynamics and Monte Carlo simulations.It was found that considerable LCOs consist-ing of the Cr-Cr and Ni-Fe short-range orders existed in the ordered configuration with optimized system energy.Through modeling the accumulation cascades up to 1000 recoils,we revealed that the size of de-fect clusters and dislocation loops is smaller in the ordered configuration than those in the random one,although the former formed more Frenkel pairs(i.e.,self-interstitials and vacancies).In addition,the dis-tribution of dislocation loops is relatively more dispersed in the ordered configuration,and the stair-rod dislocations related to irradiation swelling are also smaller,implying that the existence of LCOs is con-ducive to enhancing radiation damage tolerance.To understand the underlying mechanism,the effects of LCOs on the formation and evolution of defects and radiation resistance were discussed from the aspects of atomic bonding,migration path,and energy of defect diffusion,which provides theoretical guidance for the design of MPEAs with enhanced radiation resistance.