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991.
高血压作为全球高发的疾病,是许多心脑血管疾病的主要危险因素,给社会带来巨大的经济负担。近年来,焦虑障碍和抑郁障碍的发病率逐年上升,高血压共病焦虑抑郁的人数也在不断增加,现有的研究表明两者可能存在相互促进的关系,在发病机制上也有一定共通性,但两者共病的机制尚未完全阐明。本文就原发性高血压伴焦虑抑郁障碍的定义及诊断量表、流行病学、相互影响机制和治疗等展开综述。 相似文献
992.
目的 应用冠状动脉计算机断层扫描血管成像(CCTA)斑块定量分析,比较急性冠脉综合征(ACS)和稳定性冠心病(SCAD)患者冠状动脉斑块成分与负荷特征。方法 回顾性纳入2021年1月至3月就诊于中国人民解放军总医院第一医学中心心血管内科的116例冠心病(CAD)患者的临床资料,根据患者临床诊断结果将其分为ACS组(81例)和SCAD组(35例)。2组患者均在14 d内先后接受CCTA和冠状动脉造影检查。采用CCTA斑块定量分析软件测量各类斑块成分体积及负荷、最小管腔直径和重构指数(RI)、偏心指数(EI)等影像学指标并比较分析。采用SPSS 20.0软件进行数据分析。根据数据类型,组间比较分别采用t检验、Wilcoxon检验及χ2检验。结果 ACS组患者较SCAD组患者具有更大的总斑块负荷(TPB)、非钙化成分负荷(NCPB)和脂质成分负荷(LPB),差异均有统计学意义[(60.5±11.2)%和(51.7±14.4)%,(58.9±12.0)%和(50.1±15.2)%,17.9%(11.6%,27.6%)和14.2%(7.5%,20.8%),均P<0.0... 相似文献
993.
目的:研究一定浓度雌、孕激素作用于MCF-7细胞一定时间后,细胞中VEGF、Hsp70、Hsp90和NF-κBp50 mRNA水平上的变化,进而揭示雌、孕激素对乳腺癌MCF-7细胞株作用的分子生物学机制.方法:体外培养人乳腺癌MCF-7细胞株,分4组给予不同处理因素,分别为对照组、雌激素组、孕激素组和雌孕激素混合组.给药72 h后MTT法测细胞570 nm分光光度值.RT-PCR法观察各组Hsp70、Hsp90、VEGF和NF-κBp50 mRNA表达水平.结果:与对照组相比,10^-9mol/L雌激素促进细胞生长作用最明显,10-7mol/L孕激素本身对MCF^-7细胞生长无明显影响,但在雌、孕激素混合组孕激素部分抑制雌激素促细胞增殖作用,具有统计学意义.与对照组相比,雌激素上调细胞中Hsp70、Hsp90、VEGF和NF-κBp50 mRNA水平;孕激素组Hsp70、Hsp90、VEGF和NF-κBp50 mRNA水平与对照组差异无统计学意义.孕激素可以部分抑制雌激素对MCF-7细胞Hsp70、Hsp90、VEGF和NF-κBp50 mRNA的上调作用.结论:雌激素促进乳腺癌细胞生长,可能是雌激素与癌细胞受体结合后通过某种途径刺激Hsp70、Hsp90、NF-κBp50及VEGF的表达,进而抑制癌细胞的凋亡,促进细胞增殖.孕激素通过抑制雌激素对Hsp70、Hsp90、NF-κBp50和 VEGF mRNA的上调作用,进而抑制其促进细胞增殖作用.雌、孕激素促进或抑制细胞增殖,与其对Hsp70、Hsp90、NF-κBp50及VEGF基因的调控是密切相关的. 相似文献
994.
Rahul Ramesh Nair Moni Mohan Mondal Shanmugham Venkatachalam Srinivasan Dirk Weichgrebe 《Materials》2022,15(12)
Synthesizing biochar from mineral- and ash-rich waste biomass (MWB), a by-product of human activities in urban areas, can result in renewable and versatile multi-functional materials, which can also cater to the need of solid waste management. Hybridizing biochar with minerals, silicates, and metals is widely investigated to improve parent functionalities. MWB intrinsically possesses such foreign materials. The pyrolysis of such MWB is kinetically complex and requires detailed investigation. Using TGA-FTIR, this study investigates and compares the kinetics and decomposition mechanism during pyrolysis of three types of MWB: (i) mineral-rich banana peduncle (BP), (ii) ash-rich sewage sludge (SS), and (iii) mineral and ash-rich anaerobic digestate (AD). The results show that the pyrolysis of BP, SS, and AD is exothermic, catalyzed by its mineral content, with heat of pyrolysis 5480, 4066, and 1286 kJ/kg, respectively. The pyrolysis favors char formation kinetics mainly releasing CO2 and H2O. The secondary tar reactions initiate from ≈318 °C (BP), 481 °C (SS), and 376 °C (AD). Moreover, negative apparent activation energies are intrinsic to their kinetics after 313 °C (BP), 448 °C (SS), and 339 °C (AD). The results can support in tailoring and controlling sustainable biochar synthesis from slow pyrolysis of MWB. 相似文献
995.
Daniel Bernal Xabier Chamorro Iaki Hurtado Inmaculada Lopez-Galilea David Bürger Sebastian Weber Iaki Madariaga 《Materials》2022,15(12)
The conventional processing route of TNM (Ti-Nb-Mo) alloys combines casting and Hot Isostatic Pressing (HIP) followed by forging and multiple heat treatments to establish optimum properties. This is a time-consuming and costly process. In this study we present an advanced alternative TNM alloy processing route combining HIP and heat treatments into a single process, which we refer to as IHT (integrated HIP heat treatment), applied to a modified TNM alloy with 1.5B. A Quintus HIP lab unit with a quenching module was used, achieving fast and controlled cooling, which differs from the slow cooling rates of conventional HIP units. A Ti-42.5Al-3.5Nb-1Mo-1.5B (at.%) was subjected to an integrated two HIP steps at 200 MPa, one at 1250 °C for 3 h and another at 1260 °C for 1 h, both under a protective Ar atmosphere and followed by cooling at 30 K/min down to room temperature. The results were compared against the Ti-43.5Al-3.5Nb-1Mo-0.8B (at.%) thermomechanically processed in a conventional way. Applying IHT processing to the 1.5B alloy does indeed achieve good creep strength, and the secondary creep rate of the IHT processed materials is similar to that of conventionally forged TNM alloys. Thus, the proposed advanced IHT processing route could manufacture more cost-effective TiAl components. 相似文献
996.
Yongming Yan Yanjun Xue Wenchao Yu Ke Liu Maoqiu Wang Xinming Wang Liuqing Ni 《Materials》2022,15(12)
This paper focuses on the effect of gear steel on distortion due to phase transformation in carburizing and quenching. The carburizing and quenching process of C-rings under suspension was studied by using the finite element method based on the thermo-mechanical theory, considering phase transformation. The phase transformation kinetics parameters, depending on different carbon contents, were measured by Gleeble-3500. The distortion behavior of the carburized C-ring during the cooling stage was analyzed, as well as the carbon concentration distribution and martensite volume fractions. The accuracy of the simulation was also verified by comparing the experimental data with the simulated result of the distortion and microstructure. A reliable basis is provided for predicting the distortion mechanism of gear steels in carburizing and quenching. 相似文献
997.
V. Bharath V. Auradi G. B. Veeresh Kumar Madeva Nagaral Murthy Chavali Mahmoud Helal Rokayya Sami NI Aljuraide Jong Wan Hu Ahmed M. Galal 《Materials》2022,15(12)
The paper focused on an experimental study on the microstructural, mechanical, and wear characteristics of 15 wt.% alumina (Al2O3) particulates with an average particle size of 20 µm, reinforced in Al2014 alloy matrix composite as-cast and heat-treated samples. The metal matrix composite (MMC)samples were produced via a novel two-stage stir-casting technique. The fabricated composite samples were subjected to evaluate hardness, tensile strength, fatigue behavior and wear properties for both as cast and T6 heat-treated test samples. The Al2014 alloy and Al2014-15 wt.% Al2O3 MMCs were in solution for 1 h at a temperature of 525 °C, quenched instantly in cold water, and then artificially aged for 10 h at a temperature of 175 °C. SEM and X-ray diffraction analyses were used to investigate the microstructure and dispersion of the reinforced Al2O3 particles in the composite and the base alloy Al2014. The obtained results indicated that the hardness, tensile and fatigue strength and wear resistance increased when an amount of Al2O3 particles was added, compared to the as-cast Al2014 alloy and it was observed that after subjecting the same composite samples to heat treatment, there was further enhancement in the mechanical and wear properties in the Al2014 matrix alloy and Al2014-15 wt.% Al2O3 composite samples. 相似文献
998.
999.
詹皖 《南通大学学报(哲学社会科学版)》2006,22(1):98-100
扬琴是一种有着广泛的世界性和民族性的击弦乐器,于明代自国外传至中国。四百多年采扬琴在中国传统音乐文化环境的影响下,不断和民间音乐融合,并在一代代的扬琴艺人的探索和创新中,发展成了具有中国特色的民族乐器,成为世界扬琴三大体系之一的中国扬琴体系,同时形成了中国传统扬琴的四大流派。 相似文献
1000.
The taxonomic classification of viral sequences is frequently used for the rapid identification of pathogens, which is a key point for when a viral outbreak occurs. Both Oxford Nanopore Technologies (ONT) MinION and the Illumina (NGS) technology provide efficient methods to detect viral pathogens. Despite the availability of many strategies and software, matching them can be a very tedious and time-consuming task. As a result, we developed PIMGAVir and Vir-MinION, two metagenomics pipelines that automatically provide the user with a complete baseline analysis. The PIMGAVir and Vir-MinION pipelines work on 2nd and 3rd generation data, respectively, and provide the user with a taxonomic classification of the reads through three strategies: assembly-based, read-based, and clustering-based. The pipelines supply the scientist with comprehensive results in graphical and textual format for future analyses. Finally, the pipelines equip the user with a stand-alone platform with dedicated and various viral databases, which is a requirement for working in field conditions without internet connection. 相似文献