A Degeneration Gradient of Poplar Trees Contributes to the Taxonomic,Functional, and Resistome Diversity of Bacterial Communities in Rhizosphere Soils

Bacterial communities associated with roots influence the health and nutrition of the host plant. However, the microbiome discrepancy are not well understood under different healthy conditions. Here, we tested the hypothesis that rhizosphere soil microbial diversity and function varies along a degeneration gradient of poplar, with a focus on plant growth promoting bacteria (PGPB) and antibiotic resistance genes. Comprehensive metagenomic analysis including taxonomic investigation, functional detection, and ARG (antibiotics resistance genes) annotation revealed that available potassium (AK) was correlated with microbial diversity and function. We proposed several microbes, Bradyrhizobium, Sphingomonas, Mesorhizobium, Nocardioides, Variovorax, Gemmatimonadetes, Rhizobacter, Pedosphaera, Candidatus Solibacter, Acidobacterium, and Phenylobacterium, as candidates to reflect the soil fertility and the plant health. The highest abundance of multidrug resistance genes and the four mainly microbial resistance mechanisms (antibiotic efflux, antibiotic target protection, antibiotic target alteration, and antibiotic target replacement) in healthy poplar rhizosphere, corroborated the relationship between soil fertility and microbial activity. This result suggested that healthy rhizosphere soil harbored microbes with a higher capacity and had more complex microbial interaction network to promote plant growing and reduce intracellular levels of antibiotics. Our findings suggested a correlation between the plant degeneration gradient and bacterial communities, and provided insight into the role of high-turnover microbial communities as well as potential PGPB as real-time indicators of forestry soil quality, and demonstrated the inner interaction contributed by the bacterial communities.     

Immune Checkpoint Inhibitors: A Promising Treatment Option for Metastatic Castration-Resistant Prostate Cancer?

Since 2010, several treatment options have been available for men with metastatic castration-resistant prostate cancer (mCRPC), including immunotherapeutic agents, although the clinical benefit of these agents remains inconclusive in unselected mCRPC patients. In recent years, however, immunotherapy has re-emerged as a promising therapeutic option to stimulate antitumor immunity, particularly with the use of immune checkpoint inhibitors (ICIs), such as PD-1/PD-L1 and CTLA-4 inhibitors. There is increasing evidence that ICIs may be especially beneficial in specific subgroups of patients with high PD-L1 tumor expression, high tumor mutational burden, or tumors with high microsatellite instability/mismatch repair deficiency. If we are to improve the efficacy of ICIs, it is crucial to have a better understanding of the mechanisms of resistance to ICIs and to identify predictive biomarkers to determine which patients are most likely to benefit. This review focuses on the current status of ICIs for the treatment of mCRPC (either as monotherapy or in combination with other drugs), mechanisms of resistance, potential predictive biomarkers, and future challenges in the management of mCRPC.     

陶瓷/金属钎焊与扩散连接的研究现状

工程陶瓷由于具有优异的综合性能,在许多领域得到广泛应用,但其加工性能差,通常需要与金属组成复合结构.实现陶瓷与金属之间的可靠连接是推进陶瓷材料应用的关键,钎焊和扩散连接被认为是陶瓷/金属连接中较为适合的方法.文中对近年来国内外陶瓷/金属钎焊和扩散连接技术领域的研究现状进行了综述,认为活性金属钎焊和部分瞬间液相连接发展比较成熟,部分瞬间液相连接充分结合了活性钎焊和固相扩散连接两者的优点,将成为未来陶瓷/金属连接的发展方向.     

地聚合物混凝土配比及力学性能研究

混凝土是巷道支护过程中的重要建筑材料,然而混凝土在巷道施工中常常出现质量问题,为了不影响正常生产,需要对其进行修补。地聚合物混凝土凝结时间快,早期强度高,界面结合能力强,耐高温性和抗冻性强,耐腐蚀性良好,具有用作修补材料的潜力。以粉煤灰和矿粉为原料,Na₂SiO₃溶液和NaOH为碱激发剂制备地聚合物胶砂,研究不同的碱激发剂模数（1.0、1.2、1.4）和掺量（10%、15%、20%）对不同龄期胶砂力学性能的影响。结果表明：当碱激发剂模数为1.2,碱掺量为15%时,胶砂强度达到最大值。设计正交试验,研究了不同水胶比（0.45、0.50、0.55）、粉煤灰掺量（30%、50%、70%）和砂率（30%、35%、40%）对不同龄期地聚合物混凝土的工作性能和力学性能的影响。结果表明：粉煤灰掺量对抗压强度影响最为显著,水胶比次之,而砂率对强度发展几乎没有影响。最优的配合比为水胶比为0.50,粉煤灰掺量为50%,砂率为35%。     

液压系统原理图自动绘制软件设计

为了提高液压系统原理图的绘制效率和绘图质量，本文利用Delphi编程软件开发出液压系统原理图自动绘制软件。建立了液压元件图形库，拟定了液压元件问关联点的连线规则，并能对已绘制好的液压系统原理图进行移动、放大、缩小、删除等编辑。开发出的软件在实际应用中极大地提高了绘图效率和绘图质量。     

等误差直线逼近非圆曲线节点计算新方法

传统的等误差直线逼近法从被逼曲线的端点开始计算节点.文章在此基础上提出一种非圆曲线节点计算新方法,以被逼曲线曲率半径最小点开始,按等误差法求取节点,再根据曲线规律对节点重新进行排序,输出节点坐标值.用该种方法逼近曲线,在逼近误差等于等误差法逼近误差的条件下,节点数少于等误差法求得的节点数,文中用C语言编写新方法求取节点程序,并与传统方法进行比较,最后用曲线方程进行验证,结论正确,具有实际意义.     

APPLICATION OF MOLECULAR ORBITAL THEORY TO ANALYSIS OF PHASE STABILITY FOR ALLOYS

The critical _d vahues ( _ ) of the γ/(γ+σ).γ/(γ+μ) and γ/(γ+γ') phase boundaries insome ternar alloy phase diagrams at various temperatures are calculated by averaging the _d values of sererai selected characteristic points at the phase boundaries.Approxmateequations for the temperature dependence of the critical _d of γ/(γ+σ).γ/(γ+μ) andγ/(γ+γ') phase boundaries are established.The accuracy of the analysis is discussed in detail.It is found for the first time that the average value of the bondorder _ at the phase boundaries ts also approximatelr a constant and therefore a criticalaverage bond order _ like - can be introduced for the analysts of phase stability     

涡流检测技术在宝钢热轧轧辊上的应用

介绍了轧辊涡流检测仪的工作要求、设备组成和使用方法,指出对轧辊进行涡流检测可防止爆辊,减少轧辊磨削量。     

负热膨胀材料立方ZrMo2O8的制备研究

以ZrO(NO3)2和N6H24Mo7O24·4H2O等为原料,采用湿化学法制备出立方相ZrMo2O8粉体.对前驱体在室温～800℃进行了TG-DSC测试,采用XRD、SEM对立方相ZrMo2O8粉体进行了分析观测.结果表明亚稳相立方ZrMo2O8的制备对热处理工艺十分敏感,采用湿化学法在450℃制各出单一立方相ZrMo2O8粉体,在室温～400℃热膨胀系数为-4.337×10-6K-1.     

贵金属Cu、Ag、Au的电子结构和物理性质

由纯金属单原子理论(OA)确定了面心立方结构(FCC)贵金属Cu、Ag、Au的电子结构依次为[Ar](3dn)5.58(3dc)4.21(4sc)0.23(4sf)0.98、[Kr](4dn)4.87(4dc)4.56(5sc)0.66(5sf)0.91、[Xe](5dn)4.20(5dc)4.90(6sc)1.57(6sf)0.33,并确定了Cu、Ag、Au的密排六方结构(HCP)和体心立方结构(BCC)两种初态特征晶体和初态液体的电子结构。根据自然态的电子结构定性解释了熔点、拉伸强度、维氏硬度、体弹性模量、电导和热导率物理性质差异与电子结构的关系,定量计算了晶格常数、结合能、势能曲线及线热膨胀系数随温度的变化。根据非自然态的电子结构,定性解释了晶体结构BCC和HCP的关系。