PVDF: PI nano composite films: mechanical,FT-IR,XRD, AFM and hydraulic study

In today’s era of modern technology study of nano composite thin films are of immense importance. Unmodified PI, PVDF and PVDF incorporated PI thin films were prepared by spin coater unit using solution cast technique. PVDF was incorporated in variable lower concentrations in PI matrix at its precursor stage i.e. PAA. Thereafter, degree of crystallinity, crystalline nano particle size was evaluated using XRD and AFM technique. FT-IR was used to study the physical incorporation of PVDF particles within the PI matrix. Further, these results were used to study the microhardness, tensile and hydraulic behaviour. However, PVDF incorporated PI nano composite thin films contain overall better property in form of increased microhardness, tensile strength and less water absorption with improved morphology in comparison to unmodified film and 0.5 wt % nano composite film shows synergistic enhancement.     

基于模糊PI的电比例排量泵控制研究

针对正流量液压系统的挖掘机,使用电比例排量泵替代液控恒功率泵可以实现泵与发动机更加完美的功率匹配。但电比例排量泵的排量调节控制对算法的准确性、稳定性以及比例电磁阀的快速响应性能提出了很高要求。为满足以上条件,电比例排量泵的控制策略采用了基于BP神经网络的恒功率MAP图计算方法以及模糊逻辑整定PI参数的方法,使得电比例排量泵可以根据发动机转速和液压系统工作压力大小准确计算出变量泵排量并调度PI参数,消除液压系统时变特性与非线性对控制性能的不利影响。根据测试结果,采用模糊PI控制的挖掘机液压系统在控制准确性、稳定性方面都得到了提升。     

The GTPase Arf1 Is a Determinant of Yeast Vps13 Localization to the Golgi Apparatus

VPS13 proteins are evolutionarily conserved. Mutations in the four human genes (VPS13A-D) encoding VPS13A-D proteins are linked to developmental or neurodegenerative diseases. The relationship between the specific localization of individual VPS13 proteins, their molecular functions, and the pathology of these diseases is unknown. Here we used a yeast model to establish the determinants of Vps13′s interaction with the membranes of Golgi apparatus. We analyzed the different phenotypes of the arf1-3 arf2Δ vps13∆ strain, with reduced activity of the Arf1 GTPase, the master regulator of Golgi function and entirely devoid of Vps13. Our analysis led us to propose that Vps13 and Arf1 proteins cooperate at the Golgi apparatus. We showed that Vps13 binds to the Arf1 GTPase through its C-terminal Pleckstrin homology (PH)-like domain. This domain also interacts with phosphoinositol 4,5-bisphosphate as it was bound to liposomes enriched with this lipid. The homologous domain of VPS13A exhibited the same behavior. Furthermore, a fusion of the PH-like domain of Vps13 to green fluorescent protein was localized to Golgi structures in an Arf1-dependent manner. These results suggest that the PH-like domains and Arf1 are determinants of the localization of VPS13 proteins to the Golgi apparatus in yeast and humans.     

Role of PI3K-AKT-mTOR Pathway as a Pro-Survival Signaling and Resistance-Mediating Mechanism to Therapy of Prostate Cancer

Androgen deprivation therapy (ADT) and androgen receptor (AR)-targeted therapy are the gold standard options for treating prostate cancer (PCa). These are initially effective, as localized and the early stage of metastatic disease are androgen- and castration-sensitive. The tumor strongly relies on systemic/circulating androgens for activating AR signaling to stimulate growth and progression. However, after a certain point, the tumor will eventually develop a resistant stage, where ADT and AR antagonists are no longer effective. Mechanistically, it seems that the tumor becomes more aggressive through adaptive responses, relies more on alternative activated pathways, and is less dependent on AR signaling. This includes hyperactivation of PI3K-AKT-mTOR pathway, which is a central signal that regulates cell pro-survival/anti-apoptotic pathways, thus, compensating the blockade of AR signaling. The PI3K-AKT-mTOR pathway is well-documented for its crosstalk between genomic and non-genomic AR signaling, as well as other signaling cascades. Such a reciprocal feedback loop makes it more complicated to target individual factor/signaling for treating PCa. Here, we highlight the role of PI3K-AKT-mTOR signaling as a resistance mechanism for PCa therapy and illustrate the transition of prostate tumor from AR signaling-dependent to PI3K-AKT-mTOR pathway-dependent. Moreover, therapeutic strategies with inhibitors targeting the PI3K-AKT-mTOR signal used in clinic and ongoing clinical trials are discussed.     

Novel Dual PI3K/mTOR Inhibitor,Apitolisib (GDC-0980), Inhibits Growth and Induces Apoptosis in Human Glioblastoma Cells

Deregulated PI3K/AKT/mTOR signalling commonly exists in glioblastoma, making this axis an attractive target for therapeutic manipulation. Given that activation of PI3K/AKT/mTOR promotes tumour growth, metastasis, and resistance to anticancer therapies, mTOR inhibitors show promise in the treatment of cancer. The aim of this study was to investigate the underlying mechanism of novel dual PI3K/mTOR inhibitor, Apitolisib (GDC-0980), in A-172 and U-118-MG GBM tumour cell line suppression. It has been demonstrated that GDC-0980 induces time- and dose-dependent cytotoxicity and apoptosis in investigated glioma cell lines. In our study, the strongest induction of apoptosis was exhibited in the A-172 line after 48 h of incubation with 20 µM GDC-0980, where we observed 46.47% of apoptotic cells. In conclusion, we first discovered that dual PI3K/mTOR blockade by GDC-0980 markedly suppressed survival of human GBM cells and induced apoptosis, independent of the ER stress-mediated DR5 activation. We suggest that GDC-0980, by exerting an inhibitory effect on PERK expression, may thus block its inhibitory effect on protein synthesis, leading to intensification of translation, and this may result in an increase in apoptosis. On the other hand, CHOP stimulates protein synthesis and increases apoptosis. These findings suggest that GDC-0980 may be a candidate for further evaluation as a chemotherapeutic agent for anti-GBM therapy.     

Mechanism of action of Melaleuca armillaris (Sol. Ex Gaertu) Sm. essential oil on six LAB strains as assessed by multiparametric flow cytometry and automated microtiter-based assay

Little is known concerning the effects of essential oils (EOs) against lactic acid bacteria (LAB), either of the human gastrointestinal microflora or those involved in industrial processes. GC and GC/MS analysis of Melaleuca armillaris EO resulted in the identification of 68 compounds comprising 99.6% of the oil. Eucalyptol (1,8-cineole) was the major compound (68.9%) and the composition was largely dominated by the oxygenated monoterpenes fraction (77.3%). The anti-LAB activities of the EO were first checked by the disc diffusion assay. In a second phase, time-survival kinetics of each strain incubated with increasing concentrations of the EO (0.25, 2.5, 5 and 25 μg/ml) were established using an automated microtiter assay (Bioscreen C). Bacteriostatic or bactericidal effects were noticed depending on the studied strain and on the applied concentration of the EO. The mathematical modelling of the kinetics showed that in presence of increasing concentrations of M. armillaris EO, the lag phases of growth were extended (0.69%–97.5%) and both the growth rate and final cell density were reduced. Variations depending on the strain were noticed.     

PI实时数据库系统在石油化工生产管理中的应用

在石油化工生产中,过程信息管理系统的核心是实时数据库,它是连接生产装置控制层和企业管理层管理信息的桥梁和纽带。实时系统的采用可以为最终用户提供快捷、准确的工厂信息,增进产品的质量、减少设备瓶颈、提高产量、降低生产成本。     

迭代学习控制在电动伺服舵机系统中的应用

在传统的增量式积分分离PI控制算法的基础上。引入一D型迭代学习控制前馈环节，提高了电流和位置跟踪的快速性和跟踪精度，速度环为中间环节．在积分分离PI调节的基础上加了bangbang控制，以加快速度环的响应速度。仿真结果表明，引入D型迭代学习控制后．位置环和电流环的稳态和动态特性良好．保证了系统跟踪的快速性、精确性。     

挠性多层板材料变形的原因及解决方法

本文介绍了挠性多层板在制造过程中产生变形的原因,以及由变形所引起的问题,并使用补偿的方法使问题得到初步的解决。     

基于模糊神经网络的变换器自适应控制方法

提出了一种新型的基于模糊神经网络自适应PI调节电流控制电压型PWM变换器方法.结合了模糊神经网络控制与PI控制器,根据三相电流比较产生的三相电流误差和电流误差变化率,自动调整P、I参数,提高了电流的控制精度和变换器的动态性能.采用MATLAB/Simulink对常规PI控制器和模糊神经网络自适应PI控制器进行了仿真对比.仿真结果表明了采用模糊神经网络自适应PI控制器,其系统输出的误差及误差变化要小,系统的跟踪精度得以提高,动态性能得到改善.