多界面耦合空心核壳MnCoSe_(x)/MnO@氮掺杂碳复合材料的制备及电化学性能

通过简单的溶剂热和硒化策略以及进一步的碳层包覆程序制备氮掺杂碳壳包裹的空心MnCoSe_(x)/MnO纳米球(MnCoSe_(x)/MnO@N-C)。得益于MnCoSe_(x)和MnO之间的多界面耦合以及独特的空心核壳结构,MnCoSe_(x)/MnO@N-C复合材料具有较高的比电容和优异的倍率性能,即使在5 A/g的高电流密度下,MnCoSe_(x)/MnO@N-C仍可以稳定运行20000次循环,并保持84.6%的初始比电容。由MnCoSe_(x)/MnO@N-C和活性炭组装的非对称超级电容器器件在功率密度为810 W/kg时表现出11.2 W·h/kg的高能量密度,并拥有超长的循环寿命,在20000次循环后仍可保留初始比电容的84.0%。

Abnormal Systemic and Ocular Responses to the Valsalva Manoeuvre in Primary Open-Angle Glaucoma:A Case for Autonomic Failure?

Objective This study aimed to examine the association of primary open-angle glaucoma(POAG)with autonomic dysfunction by assessing the differences in systemic and ocular responses to an autonomic provocation test,the Valsalva manoeuvre(VM),between POAG patients and normal subjects.Methods Forty POAG and forty control subjects were subjected to the VM.Systemic and ocular parameters were measured at baseline,phase 2,and phase 4 of the VM(VM2 and VM4),where VM2 and VM4 are sympathetic and parasympathetic nervous activation states,respectively.Heart rate variability was used to assess the autonomic nervous activity,among which the high-frequency component(HF)and the low-frequency(LF)/HF ratio were used as indices of parasympathetic and sympathetic activation,respectively.Results POAG patients demonstrated higher sympathetic activation(LF/HF ratio median:2.17 vs.1.53,P=0.000)than controls at baseline and exhibited attenuated sympathetic and parasympathetic responses(a smaller change in LF/HF and HF values)during the VM than controls.During VM,the intraocular pressure(IOP),mean blood pressure(MAP),mean ocular perfusion pressure(MOPP),and the Schlemm’s canal area(SCAR)increased from baseline to VM2 and then decreased from VM2 to VM4 in both the POAG and control groups(all P<0.05).However,when we compared the changes above,the fluctuations in IOP,MAP,and MOPP were more pronounced in POAG than in controls(all P<0.05),while the changes in amplitudes of SCAR were smaller in POAG(P<0.05).Furthermore,from VM2 to VM4,the choroid thickness(ChT)in the POAG group was significantly decreased,while it was unchanged in normal subjects(P=0.258).A regression analysis showed a significant correlation of the baseline LF/HF with IOP change values(ΔIOP)from baseline to VM2 in POAG(R^(2)=0.147,P=0.014).Conclusion Patients with POAG showed more pronounced fluctuations in IOP,MAP,MOPP and ChT during the VM than controls.These reactions could be associated with autonomic dysfunction in POAG.

2012-2017年湖南省非结核分枝杆菌感染的特征分析

目的分析湖南省2012—2017年非结核分枝杆菌(NTM)的感染趋势、分布特征、流行状况,为湖南省NTM感染的防治提供参考依据。方法收集2012—2017年来自湖南省14个地级市、在湖南省胸科医院经BACTECMGIT960法确诊为分枝杆菌感染的患者15576例,其中男性11126例,女性4450例。分离出分枝杆菌菌株15576株(每例患者1株)。采用MPB64蛋白免疫胶体金法、对硝基苯甲酸(PNB)生长试验进行结核分枝杆菌复合群(MTBC)与NTM的初步鉴别,应用16SrRNA、Hsp65测序法对初步鉴定为NTM的菌株进行菌种鉴定,并对NTM感染者的相关临床资料进行分析。结果2012—2017年NTM检出率为10.17%(1584/15576);男性NTM感染者占62.06%(983/1584),女性占37.94%(601/1584);年龄分布中,40~岁的中老年患者最多,占39.02%(618/1584);职业分布以农民为主,占66.67%(1056/1584)。2016年NTM菌种分布达24种,位列前4者分别为:胞内分枝杆菌[25.23%(84/333)]、脓肿分枝杆菌[24.62%(82/333)]、戈登分枝杆菌[18.62%(62/333)]、鸟分枝杆菌[16.82%(56/333)];2017年NTM菌种分布达21种,位列前4者分别为:胞内分枝杆菌[27.15%(104/383)]、脓肿分枝杆菌[22.46%(86/383)]、戈登分枝杆菌[21.15%(81/383)],鸟分枝杆菌[17.49%(67/383)]。结论2012—2017年湖南省NTM检出率处于较高水平,感染人群以男性、中老年、农民为主,以致病NTM菌居多。

Survivin and pancreatic cancer

Pancreatic cancer is estimated to be the fourth most common cancer in men and fifth in women in the world and has poor prognosis.In recent years,more and more effort has been put on the relationship between pancreatic cancer and apoptosis.As a newly discovered inhibitor of apoptosis,survivin has drawn more attention.Strong evidence has shown that survivin is expressed in pancreatic cancer cells on frozen sections.Survivin increases in the development of pancreatic ductal adenocarcinoma and its expression can be a marker in evaluating the prognosis of pancreatic cancer patients.Survivin itself may be a new target in the treatment of pancreatic cancer and a survivin DNA vaccine could generate specific antitumor effects in pancreatic carcinoma models.

Isolation and Characterization of a New Heterotrophic Nitrifying Bacillus sp. Strain

Objective To characterize the heterotrophic nitrifying bacteria. Methods The bacteria were isolated from membrane bioreactor for treating synthetic wastewater using the method newly introduced in this study. Fluorescence in situ hybridization （FISH） was used to validate the nonexistence of autotrophic ammonia oxidizers and nitrite oxidizers. Batch tests were carried out to investigate the capability of heterotrophic nitrification by the pure culture. Phylogenetic analysis of the pure culture was performed. Results A heterotrophic nitrifier, named Bacillus sp. LY, was newly isolated from the membrane bioreactor system in which the efficiency of TN removal was up to 80%. After 24-day, incubation, the removal efficiency of COD by Bacillus sp. LY was 71.7 %. The ammonium nitrogen removal rate after assimilation nearly ceased by Bacillus sp. LY was 74.7% The phylogenetic tree of Bacillus sp. LY and the neighbouring nitrifiers were given. Conclusions The batch test results indicate that Bacillus sp. LY can utilize the organic carbon as the source of assimilation when it grows on glucose and ammonium chloride medium accompanying the formation of oxidized-nitrogen. It also can denitrify nitrate while nitrifying. Bacillus sp. LY may become a new bacterial resource for heterotrophic nitrification and play a bioremediation role in nutrient removal.

酶联免疫吸附试验在诊断HIV感染并发结核病患者中的价值

目的探讨酶联免疫吸附试验(ELISA)在HIV感染并发结核病患者中的临床诊断价值。方法收集2015年1月至2018年9月在湖南省胸科医院临床确诊的HIV感染并发结核病患者95例,HIV感染并发非结核性肺疾病患者19例。分析采用GeneXpertMTB/RIF检测技术(简称“GeneXpert”)、BACTECMGIT960检测技术(简称“MGIT960”)及ELISA法检测全血标本诊断结核病的阳性检出率;以临床诊断为标准,分析3种检测技术诊断HIV感染并发结核病患者的敏感度、特异度、阳性预测值和阴性预测值。结果GeneXpert、MGIT960法及ELISA3种检测技术对95例HIV感染并发结核病患者的检测阳性率分别为42.11%(40/95),47.37%(45/95),67.37%(64/95)。ELISA检测的阳性率明显高于GeneXpert和MGIT960,差异有统计学意义(χ2=50.031,P=0.000)。19例HIV并发非结核性肺疾病患者中GeneXpert检测阳性者0例;MGIT960检测阳性者0例;ELISA检测阳性者3例。以临床诊断为标准,GeneXpert检测的敏感度为42.11%(40/95),特异度为100.00%(19/19),阳性预测值为100.00%(40/40),阴性预测值为25.68%(19/74);MGIT960法检测的敏感度为47.37%(45/95),特异度为100.00%(19/19),阳性预测值为100.00%(45/45),阴性预测值为27.54%(19/69);ELISA法检测的敏感度为73.56%(64/87),特异度为84.21%(16/19),阳性预测值为95.52%(64/67),阴性预测值为41.03%(16/39)。结论ELISA方法有着较高的敏感度且检测快速便捷,适用于临床上对HIV感染并发结核病患者进行辅助诊断。

Influence of vibration on spatiotemporal structure of the pattern in dielectric barrier discharge

The influence of vibration on the spatiotemporal structure of the pattern in dielectric barrier discharge is studied for the first time.The spatiotemporal structure of the pattern investigated by an intensified charge-coupled device shows that it is an interleaving of three sublattices, whose discharge sequence is small rods–halos–large spots in each half-cycle of the applied voltage.The result of the photomultiplier indicates that the small rods are composed of moving filaments.The moving mode of the moving filaments is determined to be antisymmetric stretching vibration by analyzing a series of consecutive images taken by a high-speed video camera.The antisymmetric stretching vibration affects the distribution of wall charges and leads to the halos.Furthermore, large spots are discharged only at the centers of the squares consisting of vibrating filaments.The vibration mechanism of the vibrating filaments is dependent on the electric field of wall charges.

One-step construction of strongly coupled Co_(3)V_(2)O_(8)/Co_(3)O_(4)/MXene heterostructure via in-situ Co-F bonds for high performance all-solid-state asymmetric supercapacitors

Co_(3)V_(2)O_(8)/Co_(3)O_(4)/Ti_(3)C_(2)T_(x) composite was easily synthesized via one-step succinct-operated hydrothermal process.The interconnected Co_(3)V_(2)O_(8)/Co_(3)O_(4) nanowires network can in-situ grow and anchor on the surface of Ti_(3)C_(2)T_(x) via the strong Co-F bonds and contribute tremendously to depress Ti_(3)C_(2)T_(x) self-restacking.Profiting from the synergistically interplayed effect among the multiple interfaces and high conductivity of Ti_(3)C_(2)T_(x) as well as outstanding stability of the as-designed nanostructure,the optimum Co_(3)V_(2)O_(8)/Co_(3)O_(4)/Ti_(3)C_(2)T_(x)electrode reaches a commendable specific capacitance(up to 3800 mF·cm^(−2)),great rate capability(80%capacitance retention after 20-times current increasing),and preeminent cycling stability(95.4%/85.5%retention at 7000th/20,000th cycle).Moreover,the all-solid-state asymmetric supercapacitor based on Co_(3)V_(2)O_(8)/Co_(3)O_(4)/Ti_(3)C_(2)T_(x) and active carbon can deliver a high energy density of 84.0μWh·cm^(−2) at the power energy of 3.2 mW·cm^(−2),and excellent cycling durability with 87.0%of initial capacitance retention upon 20,000 loops.This work provides a practicable pathway to tailor MXene-based composites for high-performance supercapacitor.

Topological hinge modes in Dirac semimetals

Dirac semimetals(DSMs)are an important class of topological states of matter.Here,focusing on DSMs of band inversion type,we investigate their boundary modes from the effective model perspective.We show that in order to properly capture the boundary modes,k-cubic terms must be included in the effective model,which would drive an evolution of surface degeneracy manifold from a nodal line to a nodal point.Sizable k-cubic terms are also needed for better exposing the topological hinge modes in the spectrum.Using first-principles calculations,we demonstrate that this feature and the topological hinge modes can be clearly exhibited inβ-CuI.We extend the discussion to magnetic DSMs and show that the time-reversal symmetry breaking can gap out the surface bands and hence is beneficial for the experimental detection of hinge modes.Furthermore,we show that magnetic DSMs serve as a parent state for realizing multiple other higher-order topological phases,including higher-order Weyl-point/nodal-line semimetals and higher-order topological insulators.

Interactive Effects of Drought Stresses and Elevated CO_2 Concentration on Photochemistry Efficiency of Cucumber Seedlings

To reveal and quantify the interactive effects of drought stresses and elevated CO2 concentration [CO2] on photochemistry efficiency of cucumber seedlings, the portable chlorophyll meter was used to measure the chlorophyll content, and the Imaging-PAM was used to image the chlorophyll fluorescence parameters and rapid light response curves （RLC） of leaves in two adjacent greenhouses. The results showed that chlorophyll content of leaves was reduced significantly with drought stress aggravated. Minimal fluorescence （Fo） was increased while maximal quantum yield of PSII （Fv/Fm） decreased significantly by severe drought stress. The significant decrease of effective quantum yield of PSII （Y（Ⅱ）） accompanied by the significant increase of quantum yield of regulated energy dissipation （Y（NPQ）） was observed under severe drought stress condition, but there was no change of quantum yield of nonregulated energy dissipation （Y（NO））. We detected that the coefficient of photochemical quenching （qP） decreased, and non-photochemical quenching （NPQ） increased significantly under severe drought stress. Furthermore, we found that maximum apparent electron transport rate （ETRmax） and saturating photosynthetically active radiation （PPFDsat） decreased significantly with drought stress aggravated. However, elevated [CO2] significantly increased FvlFm, qP and PPFDsat, and decreased NPQ under all water conditions, although there were no significant effects on chlorophyll content, Fo, Y（Ⅱ）, Y（NPQ）, Y（NO） and ETRmax. Therefore, it is concluded that CO2-fertilized greenhouses or elevated atmospheric [CO2] in the future could be favorable for cucumber growth and development, and beneficial to alleviate the negative effects of drought stresses to a certain extent.

Phylogenomic conflict analyses in the apple genus Malus s.l.reveal widespread hybridization and allopolyploidy driving diversification,with insights into the complex biogeographic history in the Northern Hemisphere

Phylogenomic evidence from an increasing number of studies has demonstrated that different data sets and analytical approaches often reconstruct strongly supported but conflicting relationships.In this study,785 single-copy nuclear genes and 75 complete plastomes were used to infer the phylogenetic relationships and estimate the historical biogeography of the apple genus Malus sensu lato,an economically important lineage disjunctly distributed in the Northern Hemisphere and involved in known and suspected hybridization and allopolyploidy events.The nuclear phylogeny recovered the monophyly of Malus s.l.(including Docynia);however,the genus was supported to be biphyletic in the plastid phylogeny.An ancient chloroplast capture event in the Eocene in western North America best explains the cytonuclear discordance.Our conflict analysis demonstrated that ILS,hybridization,and allopolyploidy could explain the widespread nuclear gene tree discordance.One deep hybridization event(Malus doumeri)and one recent event(Malus coronaria)were detected in Malus s.l.Furthermore,our historical biogeographic analysis integrating living and fossil data supported a widespread East Asianwestern North American origin of Malus s.l.in the Eocene,followed by several extinction and dispersal events in the Northern Hemisphere.We also propose a general workflow for assessing phylogenomic discordance and biogeographic analysis using deep genome skimming data sets.

ProSy: API-Based Synthesis with Probabilistic Model

Program synthesis is an exciting topic that desires to generate programs satisfying user intent automatically. But in most cases, only small programs for simple or domain-specific tasks can be synthesized. The major obstacle of synthesis lies in the huge search space. A common practice in addressing this problem is using a domain-specific language, while many approaches still wish to synthesize programs in general programming languages. With the rapid growth of reusable libraries, component-based synthesis provides a promising way, such as synthesizing Java programs which are only composed of APIs (application programming interfaces). However, the efficiency of searching for proper solutions for complex tasks is still a challenge. Given an unfamiliar programming task, programmers would search for API usage knowledge from various coding resources to reduce the search space. Considering this, we propose a novel approach named ProSy to synthesize API-based programs in Java. The key novelty is to retrieve related knowledge from Javadoc and Stack Overflow and then construct a probabilistic reachability graph. It assigns higher probabilities to APIs that are more likely to be used in implementing the given task. In the synthesis process, the program sketch with a higher probability will be considered first;thus, the number of explored reachable paths would be decreased. Some extension and optimization strategies are further studied in the paper. We implement our approach and conduct several experiments on it. We compare ProSy with SyPet and other state-of-the-art API-based synthesis approaches. The experimental results show that ProSy reduces the synthesis time of SyPet by up to 80%.

Warm deformation behavior and work-softening mechanism of Fe- 6.5wt.%Si alloy

Warm deformation behavior of the Fe-6.5wt.%Si alloy was studied by isothermal compression in the temperature range of 300-700℃.The results show that the influence of the ordered phases on the flow stress gradually weakens with increasing deformation temperature.The flow stress of the furnace-cooled sample with the high degree of order at 300℃is higher than that of the quenched sample with the low degree of order,and the flow stresses of both samples are nearly the same at 500-700℃.The hardness difference between two samples deformed at 500℃gradually decreases with increasing strain,accompanying with a reduction in hardness of the furnace-cooled sample,which indicates a work-softening behavior.The analyses of dislocation configurations and ordered structure suggest that the dynamic recovery and deformation-induced disorder result in the work-softening behavior.An appropriate deformation temperature window for improving the formability of the Fe-6.5wt.%Si alloy is about 500-600℃.

Scaling analysis of current influence on Hastelloy surface roughness in electro-polishing process

In this study, a series of Hastelloy tapes were electro-polished, and the dividing method was used to carry out a detailed investigation on the influence of polishing current(I) on root mean square(R_q) at various image scales(L). The electro-polishing is found to be effective mainly at L smaller than 10μm, where the R_q–I relationship could be fitted by an exponential decay function with a residual roughness value. An approximate model of electro-polishing process was established to interpret the exponential decay function. This study provides a quantified insight into the electro-polishing process, which could help to obtain more understanding of its mechanism.