374例根治术后肠型胃癌患者预后的影响因素分析

目的:肠型胃癌约占中国胃癌总数的40%~45%,本研究旨在探讨根治术后肠型胃癌预后的影响因素。方法:回顾性收集2010年7月至2015年7月于山东第一医科大学附属省立医院行根治性切除且术后病理证实为肠型胃癌患者的临床病理和预后资料。Log-rank检验比较各临床病理特征对无病生存期(disease-free survival,DFS)和总生存期(overall survival,OS)的影响。单因素分析中P<0.1的因素纳入Cox多因素回归分析。结果:共纳入374例患者,5年DFS率为73.4%,5年OS率为79.7%。单因素分析显示>60岁、组织学中分化、肿瘤直径>3 cm、T3~4期、淋巴结浸润、TNM分期晚、非远端胃癌、脉管癌栓、神经侵犯、人表皮生长因子受体-2(human epidermal growth factor receptor-2,HER-2)过表达和高血小板-淋巴细胞比值(platelet-to-lym phocyte ratio,PLR)与DFS和OS不佳显著相关(P<0.05)。多因素分析显示年龄、神经侵犯和TNM分期为DFS和OS的独立预后因素。结论:年龄>60岁、组织学中分化、肿瘤直径>3 cm、TNM分期晚、非远端胃癌、脉管癌栓、神经侵犯、HER-2过表达和高PLR是根治术后肠型胃癌预后不良的危险因素。年龄、神经侵犯和TNM分期是根治术后肠型胃癌预后的独立预测因素。

Optimization Analysis of the Mixing Chamber and Diffuser of Ejector Based on Fano Flow Model

An improved model to calculate the length of the mixing chamber of the ejector was proposed on the basis of the Fano flow model,and a method to optimize the structures of the mixing chamber and diffuser of the ejector was put forward.The accuracy of the model was verified by comparing the theoretical results calculated using the model to experimental data reported in literature.Variations in the length of the mixing chamber L_(m) and length of the diffuser L_(d) with respect to variations in the outlet temperature of the ejector T_(c),outlet pressure of the ejector p_(c),and the expansion ratio of the pressure of the primary flow to that of the secondary flow p_(g)/p_(e) were investigated.Moreover,variations in L_(m) and L_(d) with respect to variations in the ratio of the diameter of the throat of the motive nozzle to the diameter of the mixing chamber d_(g0)/d_(c3) and ratio of the outlet diameter of the diffuser to the diameter of themixing chamber d_(c)/d_(c3) were investigated.The distribution of flow fields in the ejector was simulated.Increasing L_(m) and d_(c3) reduced T_(c) and p_(c).Moreover,reducing p_(g)/p_(e) or d_(g0)/d_(c3) reduced T_(c) and p_(c).The length of the mixed section L_(m2),which was determined on the basis of the Fano flow model,increased as pg increased and decreased as d_(c3) increased.The mixing length L_(m1),which was considered the primary flow expansion,showed the opposite trend with that of L_(m2).Moreover,Ld increased as p_(g)/p_(e) and d_(c)/d_(c3) increased.When the value of d_(c) was 1.8 to 2.0 times as high as that of dc3,the semi-cone angle of the diffuser ranged between 6°and 12°.At a constant dc/dc3,decreasing T_(c) and pc increased Ld.

Observation and simulation of the diffuse attenuation coefficient of downwelling irradiance in the Polar Ocean

The three-stream radiation transfer model is used to investigate the fluctuation in the underwater diffuse attenuation coefficient of downwelling irradiance in the polar ocean with a high solar zenith angle and different direct radiation proportions.First,the applicability of the three-stream radiation model in the polar region is validated by using 18 in situ observation data from September to October 2009 in the Beaufort Sea.Statistics show that in the absence of sea ice,the average relative errors between the simulation and observation values for 490 nm downwelling irradiance (E_(d)(490)) and its diffuse attenuation coefficient (K_(d)(490)) are 7.04%and 9.88%,respectively.At the stations surrounded by sea ice,the radiation is relatively small due to ice blocking,and the average relative errors simulated by the model reach 15.89%and 15.55%,respectively.Second,simulations with different chlorophyll concentrations and different proportions of direct radiation reveal that a high solar zenith angle has a greater impact on K_(d)(490) in the surface water.K_(d)(490) is less affected by the light field (affected by the solar zenith angle and the proportion of direct radiation) at depths greater than 30 m,and meets the linear relationship with the inherent optical parameters(the sum of the absorption coefficient and backscattering coefficient).The surface K_(d)(490) is still consistent with that at a depth of more than 50 meters under a high solar zenith angle,implying that the surface K_(d)(490) can also be considered as an inherent optical parameter at a high solar zenith angle (greater than 60 degrees).The relative error of obtaining surface K_(d)(490) by using the linear relationship at the 50 m layer is found to be less than 8%in the seawater with chlorophyll concentration greater than0.05 mg m^(-3).The effect of the solar zenith angle and proportion of direct radiation can be ignored when measuring the diffuse attenuation coefficient in the polar region.Finally,the model can correct the ice-induced fluctuation in downward irradiance,allowing for optical research of seawater beneath the ice in the polar ocean.

Molecular ecological networks reveal the spatial-temporal variation of microbial communities in drinking water distribution systems

Microbial activity and regrowth in drinking water distribution systems is a major concern for water service companies.However,previous studies have focused on the microbial composition and diversity of the drinkingwater distribution systems(DWDSs),with little discussion on microbial molecular ecological networks(MENs)in different water supply networks.MEN analysis explores the potentialmicrobial interaction and the impact of environmental stress,to explain the characteristics of microbial community structures.In this study,the random matrix theory-based network analysis was employed to investigate the impact of seasonal variation including water source switching on the networks of three DWDSs that used different disinfection methods.The results showed that microbial interaction varied slightly with the seasons but was significantly influenced by different DWDSs.Proteobacteria,identified as key species,play an important role in the network.Combined UV-chlorine disinfection can effectively reduce the size and complexity of the network compared to chlorine disinfection alone,ignoring seasonal variations,which may affect microbial activity or control microbial regrowth in DWDSs.This study provides new insights for analyzing the dynamics of microbial interactions in DWDSs.

Co-N-C单原子催化剂电催化氧还原反应的研究进展

多孔氮掺杂碳材料负载的Co单原子催化剂(Co-N-C)因其在电催化氧还原反应(ORR)中展现出优异的性能而受到广泛关注.通过对催化剂的设计和对反应条件的优化, Co-N-C可以电催化ORR得到水、过氧化氢等不同产物,因此在金属空气电池、燃料电池以及化工生产等方面具有重要的应用前景.然而,在不同条件下Co-N-C催化ORR反应的电子转移途径,即决定ORR反应选择性的关键因素尚无定论.本文综述了近年来Co-N-C催化ORR反应的相关研究进展,从单原子催化剂位点的微环境、中心金属原子掺杂种类、催化剂载体选择以及催化反应条件等方面进行了分析,着重探讨了氧气吸附能、反应中间体结合能等参数的变化,进而对不同条件下决定ORR反应选择性的关键因素进行了讨论.

Design, Synthesis, and Evaluation of Fungicidal Activity of Novel Pyrazole-Containing Strobilurin Derivatives

In searching for novel fungicidal leads,a series of pyrazole-containing strobilurins were rationally designed,synthesized and charac-terized.Bioassay indicated that compound 1-7 displayed excellent fungicidal activity against a broad spectrum of plant pathogens such as Gibberella zeae,Rhizoctonia cereolis,Sclerotinia sclerotiorum,Phytophthora infestans,Physolosporo piricola and Pellicularia sosakii with EC_(50) of 0.16,0.02,0.72,0.07,0.77 and 0.65μg/mL,respectively,which were 3-10 times more potent than the positive control azoxystrobin against the corresponding pathogens.Moreover,like azoxystrobin and kresoxim methyl,1-7,displayed excellent protec-tive activity against P.sorghi.Molecular docking validated that 1-7 and azoxystrobin would share a similar binding mode with cytochrome bc_(1) complex.This study demonstrates that 1-7 is a promising fungicidal candidate for further development.