找好接班人:CIO谋求上位的第一步

对CIO们而言,制订一个灵活的继任者计划,帮助公司培养未来IT领导人。直接关乎自己职业宏图的拓展。毕竟,在没有得到一个足够优秀的人才来接替你的工作之前,CEO怎么会将你调任到其他新岗位呢？     

T-Cell Response against Varicella Zoster Virus in Patients with Multiple Sclerosis during Relapse and Remission

An association between varicella zoster virus (VZV) and multiple sclerosis (MS) has been reported in Mexican populations. The aim of this study was to compare the response of T cells from MS patients, during relapse and remission, to in vitro stimulation with VZV, adenovirus (AV) and Epstein–Barr virus (EBV). Proliferation and cytokine secretion of T cells from 29 relapsing-remitting MS patients and 38 healthy controls (HC) were analyzed by flow cytometry after stimulating with VZV, AV or EBV. IgG and IgM levels against VZV and EBV were quantified using Enzyme-Linked Immunosorbent Assay. Relapsing MS patients showed a higher percentage of responding CD4+ and CD8+ T cells against VZV compared to AV. In HC and remitting MS patients, proliferation of CD4+ T cells was higher when stimulated with VZV as compared to EBV. Moreover, T cells isolated from remitting patients secreted predominantly Th1 cytokines when cell cultures were stimulated with VZV. Finally, high concentration of anti-VZV IgG was found in sera from patients and controls. The results support previous studies of an VZV-MS association in the particular population studied and provide additional information about the possible role of this virus in the pathogenesis of MS.     

包容性工程—借助工程技术发明为身体或精神障碍人士赋能

1. Background The use of engineering tools, design, research, and thinking to create environments and capabilities whereby individuals who are currently under-e...     

Water Vapor‐Enhanced Diffusion in Alumina

Experimental results indicate effective faster diffusion of oxygen in polycrystalline alumina when exposed to water vapor at high temperatures. α‐Al₂O₃ containing Ni metal particles was exposed to dry air or humid environments at 1300°C for up to 20 h. Oxidation of Ni in α‐Al₂O₃ to form NiAl₂O₄ was used to determine oxygen diffusion depth from the surface. The apparent kinetic rate constant for oxygen diffusion in the presence of water vapor was 79% higher compared with that in a dry atmosphere at 1300°C (1.4 × 10^?13 m²/s for 0.2 atm versus 7.9 × 10^?14 m²/s for dry air). (OH)^? ions are smaller and more polarizable than O^2?, which would be expected to lead to faster diffusion. This effect may impact sintering, creep, corrosion, oxidation, and the performance of thermal barrier coatings (TBC).     

Thermal, optical, electrochemical properties and conductivity of trans- and cis-poly(1-ethynylpyrene): a comparative investigation

The thermal, optical and electrochemical properties of trans-poly(1-ethynylpyrene) (trans-PEP) and cis-poly(1-ethynylpyrene) (cis-PEP) have been studied as a function of polymer backbone configuration and internal stacking. Absorption spectra of the polymers showed that trans-PEP possesses a higher degree of conjugation than its homologue, cis-PEP. Intramolecular interactions occur between adjacent pendant pyrene units (associated pyrenes) present in each polymer, giving rise to static excimer emissions, strongest in cis-PEP because of the shorter distances between aromatic rings. Data resulting from excitation spectra and fluorescence decay profiles proved that such interactions take place in the ground state. Cyclic voltammetry of trans- and cis-PEP exhibited irreversible behaviors with different oxidation potentials as a result of their dissimilar geometry.     

Sirtuins Modulation: A Promising Strategy for HIV-Associated Neurocognitive Impairments

HIV-Associated neurocognitive disorder (HAND) is one of the major concerns since it persists in 40% of this population. Nowadays, HAND neuropathogenesis is considered to be caused by the infected cells that cross the brain–blood barrier and produce viral proteins that can be secreted and internalized into neurons leading to disruption of cellular processes. The evidence points to viral proteins such as Tat as the causal agent for neuronal alteration and thus HAND. The hallmarks in Tat-induced neurodegeneration are endoplasmic reticulum stress and mitochondrial dysfunction. Sirtuins (SIRTs) are NAD+-dependent deacetylases involved in mitochondria biogenesis, unfolded protein response, and intrinsic apoptosis pathway. Tat interaction with these deacetylases causes inhibition of SIRT1 and SIRT3. Studies revealed that SIRTs activation promotes neuroprotection in neurodegenerative diseases such Alzheimer’s and Parkinson’s disease. Therefore, this review focuses on Tat-induced neurotoxicity mechanisms that involve SIRTs as key regulators and their modulation as a therapeutic strategy for tackling HAND and thereby improving the quality of life of people living with HIV.     

Crystallization of Sol–Gel-Derived Barium Strontium Titanate Thin Films

Microstructural development of thin-film barium strontium titanate (Ba _x Sr_{1– x} TiO₃) as a function of strontium concentration and thermal treatment were studied, using transmission electron microscopy (TEM) and X-ray diffractometry (XRD). Thin films, ∼250 nm thick, were spin-coated onto Pt/Ti/SiO₂/Si substrates, using methoxypropoxide alkoxide precursors, and crystallized by heat-treating at 700°C. All films had the cubic perovskite structure, and their lattice parameters varied linearly with strontium content. Films with higher strontium concentrations had a larger average grain size. In situ TEM heating experiments, combined with differential thermal analysis/thermogravimetric analysis results, suggest that the gel films crystallize as an intermediate carbonate phase, Ba _x Sr_{1– x} TiO₂CO₃ (with a solid solution range from x = 1 to x = 0). Before decomposition at 600°C, this carbonate phase inhibits the formation of the desired perovskite phase.     

Towards Efficient Nonenzymatic DNA Ligation: Comparing Key Parameters for Maximizing Ligation Rates and Yields with Carbodiimide Activation**

Chemical ligation is an important tool for the generation of synthetic DNA structures, which are used for a wide range of applications. Surprisingly, reported chemical ligation yields can range from 30 to 95 % for the same chemical activating agent and comparable DNA structures. We report a systematic study of DNA ligation by using a well-defined bimolecular test system and a water-soluble carbodiimide (EDC) as a phosphate-activating agent. Our results emphasize the interplay between template-substrate complex stability and the rates of the chemical steps of ligation, with 3′ phosphate substrates providing yields near 100 % after 24 hours for particularly favorable reaction conditions. Ligation rates are also shown to be sensitive to the identity of the base pairs flanking a nick site, with as much as threefold variation. Finally, the observation that DNA substrates are modified by EDC at rates that can be comparable with ligation rates emphasizes the importance of considering side reactions when designing protocols to maximize ligation yields.     

Flash sintering of a three‐phase alumina,spinel, and yttria‐stabilized zirconia composite

Three‐phase ceramic composites constituted from equal volume fractions of α‐Al₂O₃, MgAl₂O₄ spinel, and cubic 8 mol% Y₂O₃‐stabilized ZrO₂ (8YSZ) were flash‐sintered under the influence of DC electric fields. The temperature for the onset of rapid densification (flash sintering) was measured using a constant heating rate at fields of 50‐500 V/cm. The experiments were carried out by heating the furnace at a constant rate. Flash sintering occurred at a furnace temperature of 1350°C at a field of 100 V/cm, which dropped to 1150°C at a field of 500 V/cm. The sintered densities ranged from 90% to 96%. Higher electric fields inhibited grain growth due to the lowering of the flash temperature and an accelerated sintering rate. During flash sintering, alumina reacted with the spinel phase to form a high‐alumina spinel solid solution, identified by electron dispersive spectroscopy and from a decrease in the spinel lattice parameter as measured by X‐ray diffraction. It is proposed that the solid solution reaction was promoted by a combination of electrical field and Joule heating.