Type B CTD Proteins Secreted by the Type IX Secretion System Associate with PorP-like Proteins for Cell Surface Anchorage

The Bacteroidetes type IX secretion system (T9SS) consists of at least 20 components that translocate proteins with type A or type B C-terminal domain (CTD) signals across the outer membrane (OM). While type A CTD proteins are anchored to the cell surface via covalent linkage to the anionic lipopolysaccharide, it is still unclear how type B CTD proteins are anchored to the cell surface. Moreover, very little is known about the PorE and PorP components of the T9SS. In this study, for the first time, we identified a complex comprising the OM β-barrel protein PorP, the OM-associated periplasmic protein PorE and the type B CTD protein PG1035. Cross-linking studies supported direct interactions between PorE-PorP and PorP-PG1035. Furthermore, we show that the formation of the PorE-PorP-PG1035 complex was independent of PorU and PorV. Additionally, the Flavobacterium johnsoniae PorP-like protein, SprF, was found bound to the major gliding motility adhesin, SprB, which is also a type B CTD protein. Together, these results suggest that type B-CTD proteins may anchor to the cell surface by binding to their respective PorP-like proteins.     

Effect of substrate patterning on hydroxyapatite sol-gel thin film growth

The effect of substrate patterning on hydroxyapatite (HA) sol-gel thin film growth is investigated. Sol-gel derived HA was spun onto wet and dry etched micro-patterned titanium substrates to obtain thin films of thickness ~ 400 nm. The amorphous films were made crystalline by firing at temperatures ranging from 650 to 850 °C for 5 min. Rutherford backscattering spectrometry (RBS), X-ray diffraction (XRD), and atomic force microscopy (AFM) were used to characterize the films. Crystal sizes calculated from XRD data show that films on patterned substrates contained larger grains than those on un-patterned substrates. The films on wet etched substrates contained larger grains than the films on dry etched substrates. AFM results confirm XRD results. A marked difference between the films on patterned and unpatterned substrates was observed, with those on the patterned substrates being much rougher than those on the unpatterned substrates. The films inside the channels contained larger grains than those outside of channels, on the polished, unetched portion of the substrate.     

微波等离子体CVD法在非平面基体上生长金刚石膜

介绍了在微波等离子体CVD装置中,用甲烷和氢气作为原料,在非平面基体(如钨丝、钻头、铣刀等)上生长金刚石薄膜的研究。在金刚石沉积过程中,由于"尖端效应",在基体的尖端很难沉积出金刚石膜。在采用金属丝屏蔽后,克服了"尖端效应",成功地在非平面基体上沉积出了金刚石膜。用扫描电镜(SEM)和激光拉曼光谱(Raman)分析了金刚石膜的形貌和质量。结果表明:非平面基体不同位置金刚石的晶形不同,晶粒比较细小,膜的质量较高。     

电子器件功率模块用铝基板草酸阳极氧化工艺参数优化

采用草酸阳极氧化工艺对电子器件功率模块用铝基板进行表面处理,并考察了电解液温度、电流密度和氧化时间对氧化膜的厚度及腐蚀失重的影响.结果表明:电流密度从1 A/dm2增加到3 A/dm2,氧化时间从35 min延长到75 min,氧化膜厚度都呈先增加后降低的趋势并且伴随着腐蚀失重先降低后增加.采用单一变量法得到铝基板草酸...     

微波数字复合基板金属化孔工艺方法

微波数字复合基板是将微波电路与数字电路集合在一起的新型复合多层基板,其体积的缩小实现了雷达天线系统的轻量化和小型化.在复合基板的制作过程中,金属化孔的可靠性是保证天线电性能指标的关键.主要介绍了微波数字复合基板中微盲孔孔金属化及提高金属化孔可靠性的工艺方法.     

(Pb1-xSrx)TiO3薄膜的结构与光学特性研究

采用sol-gel法制备(Pb1-xSrx)TiO3(x=0.40,0.50,0.60,0.70,简称PST40,PST50,PST60与PST70)前驱体溶液,通过旋涂工艺在石英玻璃基片上沉积PST薄膜。研究了PST薄膜的结构和光学特性。结果显示,经750℃退火30min,所得PST薄膜为晶化良好的钙钛矿立方结构,薄膜平均晶粒尺寸为200～300nm。750℃退火的PST40、PST50、PST60和PST70薄膜样品的直接带隙能分别为3.74,3.79,3.80和3.85eV。随着Sr含量的增加,带隙能增加。     

Growth and characterization of β-Ga2O3 thin films grown on off-angled Al2O3 substrates by metal-organic chemical vapor deposition

Beta-gallium oxide (β-Ga₂O₃) thin films were deposited on c-plane (0001) sapphire substrates with different mis-cut angles along <\begin{document}$11\bar{2}0$\end{document}> by metal-organic chemical vapor deposition (MOCVD). The structural properties and surface morphology of as-grown β-Ga₂O₃ thin films were investigated in detail. It was found that by using thin buffer layer and mis-cut substrate technology, the full width at half maximum (FWHM) of the (\begin{document}$ \bar{2}01$\end{document}) diffraction peak of the β-Ga₂O₃ film is decreased from 2° on c-plane (0001) Al₂O₃ substrate to 0.64° on an 8° off-angled c-plane (0001) Al₂O₃ substrate. The surface root-mean-square (RMS) roughness can also be improved greatly and the value is 1.27 nm for 8° off-angled c-plane (0001) Al₂O₃ substrate. Room temperature photoluminescence (PL) was observed, which was attributed to the self-trapped excitons formed by oxygen and gallium vacancies in the film. The ultraviolet–blue PL intensity related with oxygen and gallium vacancies is decreased with the increasing mis-cut angle, which is in agreement with the improved crystal quality measured by high resolution X-ray diffraction (HR-XRD). The present results provide a route for growing high quality β-Ga₂O₃ film on Al₂O₃ substrate.     

N,N′‐Dioxide‐Magnesium Ditriflate Complex‐Catalyzed Asymmetric α‐Hydroxylation of β‐Keto Esters and β‐Keto Amides

The highly catalytic asymmetric α‐hydroxylation of 1‐tetralone‐derived β‐keto esters and β‐keto amides using tert‐butyl hydroperoxide (TBHP) as the oxidant was realized by a chiral N,N′‐dioxide‐magnesium ditriflate [Mg(OTf)₂] complex. A series of corresponding chiral α‐hydroxy dicarbonyl compounds was obtained in excellent yields (up to 99%) with excellent enantioselectivities (up to 98% ee). The products were easily transformed into useful building blocks and the precursor of daunomycin was achieved in an asymmetric catalytic way for the first time.     

Light Fueled Manipulation of Bubble Motion Against Buoyancy via Photosensitive Substrate

Flexibly and precisely controlling bubbles is of paramount significance for biological and chemical analysis, reaction engineering, etc. However, the buoyancy force acting on bubbles is significant, making it difficult to precisely manipulate bubbles. Particularly, controlling the anti-buoyancy motion of bubbles remains a fundamental challenge. Herein, a versatile light strategy for manipulating the anti-buoyancy motion of bubbles via a photosensitive substrate is developed. Upon focused laser beam irradiation, an intense Marangoni effect associated with non-uniform temperature distribution is induced underneath the bubble. The created excess Laplace pressure drives the bubble to move against the buoyancy force downward to the focused-laser-acted region, manifesting an excellent phototaxis motion. Theoretical analysis demonstrates that the Marangoni effect is responsible for actuating the anti-buoyancy motion of a bubble. With this light strategy, the bubble collection, transportation, and on-demand release can be flexibly implemented. Moreover, the phototaxis motion of bubbles inspires a manipulation protocol via the integration of 3D-structured design of photosensitive substrate. This light strategy for manipulating bubbles not only possesses sufficiently high accuracy and quick response, but also circumvents the limitation of the liquid volatility and multi-dimensional motion, which provides new ideas for rational control of bubble behaviors.     

Chemical Probes for Profiling of MALT1 Protease Activity

The paracaspase MALT1 is a key regulator of the human immune response. It is implicated in a variety of human diseases. For example, deregulated protease activity drives the survival of malignant lymphomas and is involved in the pathophysiology of autoimmune/inflammatory diseases. Thus, MALT1 has attracted attention as promising drug target. Although many MALT1 inhibitors have been identified, molecular tools to study MALT1 activity, target engagement and inhibition in complex biological samples, such as living cells and patient material, are still scarce. Such tools are valuable to validate MALT1 as a drug target in vivo and to assess yet unknown biological roles of MALT1. In this review, we discuss the recent literature on the development and biological application of molecular tools to study MALT1 activity and inhibition.