Magnetization dynamics and related phenomena in semiconductors with ferromagnetism

We review ferromagnetic resonance (FMR) and related phenomena in the ferromagnetic semiconductor (Ga,Mn)As and single crystalline Fe/GaAs (001) hybrid structures. In both systems, spin-orbit interaction is the key ingredient for various intriguing phenomena.     

高温氦气环境中石墨的水蒸气氧化特性模拟研究

在正常运行工况下高温气冷堆内石墨材料的氧化对石墨结构材料的服役时间有重要影响.主要介绍高温气冷堆燃料元件氦气孔道内石墨材料与水蒸气发生氧化反应的模拟.该模型使用COMSOL软件进行建模,采用k-ε模型模拟冷却剂的流动,使用Langmuir-Hinshelwood方程描述石墨与水蒸气的化学反应.使用该模型计算了冷却剂管道温度分布为线性、水蒸气压力低于1 Pa的氧化情况.计算结果表明,在堆芯底部氧化主要发生在表面,石墨材料转化率高于8%的厚度约1 mm.     

Anwendungen für Mehrphasen-CFD am Fahrzeugexterieur

Forschung im Ingenieurwesen - In der Automobilindustrie werden einphasige Strömungssimulationen seit vielen Jahren zur Aerodynamik- und Aeroakustikentwicklung eingesetzt. Sie gewähren...     

Elektrische Darstellung mathematischer Funktionen

Zusammenfassung Der Aufsatz zeigt Verfahren und Schaltungen, nach welchen jede algebraische Funktionn-ten Grades undm-ter Ordnung dargestellt und gelöst werden kann. Einige Anwendungsbeispiele aus der Meß- und Regeltechnik sowie der Fall einer elektrischen Rechenmaschine für Gleichungenm-ten Grades undn-ter Ordnung werden kurz gestreift. Über geometrische und transzendente Funktionen sowie über Anwendungen und praktische Probleme soll in einigen späteren Folgen berichtet werden.     

Development of a Molecular Aptamer Beacon Applied to Magnetic-Assisted RNA Extraction for Detection of Dengue and Zika Viruses Using Clinical Samples

Limitations in the detection of cocirculating flaviviruses such as Dengue and Zika lead us to propose the use of aptameric capture of the viral RNA in combination with RT-PCR (APTA-RT-PCR). Aptamers were obtained via SELEX and next-generation sequencing, followed by colorimetric and fluorescent characterizations. An APTA-RT-PCR assay was developed, optimized, and tested against the viral RNAs in 108 serum samples. After selection, sequence APTAZC10 was designed as a bifunctional molecular beacon (APTAZC10-MB), exhibiting affinity for the viral targets. APTA-RT-PCR was able to detect Dengue and Zika RNA in 43% and 8% of samples, respectively. Our results indicate that APTAZC10-MB and APTA-RT-PCR will be useful to improve the detection of Dengue and Zika viruses in a fast molecular assay for the improvement of infectious disease surveillance.     

Different Involvement of Vimentin during Invasion by Listeria monocytogenes at the Blood–Brain and the Blood–Cerebrospinal Fluid Barriers In Vitro

The human central nervous system (CNS) is separated from the blood by distinct cellular barriers, including the blood–brain barrier (BBB) and the blood–cerebrospinal fluid (CFS) barrier (BCSFB). Whereas at the center of the BBB are the endothelial cells of the brain capillaries, the BCSFB is formed by the epithelium of the choroid plexus. Invasion of cells of either the BBB or the BCSFB is a potential first step during CNS entry by the Gram-positive bacterium Listeria monocytogenes (Lm). Lm possesses several virulence factors mediating host cell entry, such as the internalin protein family—including internalin (InlA), which binds E-cadherin (Ecad) on the surface of target cells, and internalin B (InlB)—interacting with the host cell receptor tyrosine kinase Met. A further family member is internalin (InlF), which targets the intermediate filament protein vimentin. Whereas InlF has been shown to play a role during brain invasion at the BBB, its function during infection at the BCSFB is not known. We use human brain microvascular endothelial cells (HBMEC) and human choroid plexus epithelial papilloma (HIBCPP) cells to investigate the roles of InlF and vimentin during CNS invasion by Lm. Whereas HBMEC present intracellular and surface vimentin (besides Met), HIBCPP cells do not express vimentin (except Met and Ecad). Treatment with the surface vimentin modulator withaferin A (WitA) inhibited invasion of Lm into HBMEC, but not HIBCPP cells. Invasion of Lm into HBMEC and HIBCPP cells is, however, independent of InlF, since a deletion mutant of Lm lacking InlF did not display reduced invasion rates.     

The Role of TKS5 in Chromosome Stability and Bladder Cancer Progression

TKS5 promotes invasion and migration through the formation of invadopodia in some tumour cells, and it also has an important physiological function in cell migration through podosome formation in various nontumour cells. To date, the role of TKS5 in urothelial cells, and its potential role in BC initiation and progression, has not yet been addressed. Moreover, the contribution of TKS5 to ploidy control and chromosome stability has not been reported in previous studies. Therefore, in the present study, we wished to address the following questions: (i) Is TKS5 involved in the ploidy control of urothelial cells? (ii) What is the mechanism that leads to aneuploidy in response to TKS5 knockdown? (iii) Is TKS5 an oncogene or tumour-suppressor gene in the context of BC? (iv) Does TKS5 affect the proliferation, migration and invasion of BC cells? We assessed the gene and protein expressions via qPCR and Western blot analyses in a set of nontumour cell strains (Y235T, HBLAK and UROtsa) and a set of BC cell lines (RT4, T24, UMUC3 and J82). Following the shRNA knockdown in the TKS5-proficient cells and the ectopic TKS5 expression in the cell lines with low/absent TKS5 expression, we performed functional experiments, such as metaphase, invadopodia and gelatine degradation assays. Moreover, we determined the invasion and migration abilities of these genetically modified cells by using the Boyden chamber and wound-healing assays. The TKS5 expression was lower in the bladder cancer cell lines with higher invasive capacities (T24, UMUC3 and J82) compared to the nontumour cell lines from human ureter (Y235T, HBLAK and UROtsa) and the noninvasive BC cell line RT4. The reduced TKS5 expression in the Y235T cells resulted in augmented aneuploidy and impaired cell division. According to the Boyden chamber and wound-healing assays, TKS5 promotes the invasion and migration of bladder cancer cells. According to the present study, TKS5 regulates the migration and invasion processes of bladder cancer (BC) cell lines and plays an important role in genome stability.     

High-Throughput Strategies for the Design,Discovery, and Analysis of Bismuth-Based Photocatalysts

Bismuth-based nanostructures (BBNs) have attracted extensive research attention due to their tremendous development in the fields of photocatalysis and electro-catalysis. BBNs are considered potential photocatalysts because of their easily tuned electronic properties by changing their chemical composition, surface morphology, crystal structure, and band energies. However, their photocatalytic performance is not satisfactory yet, which limits their use in practical applications. To date, the charge carrier behavior of surface-engineered bismuth-based nanostructured photocatalysts has been under study to harness abundant solar energy for pollutant degradation and water splitting. Therefore, in this review, photocatalytic concepts and surface engineering for improving charge transport and the separation of available photocatalysts are first introduced. Afterward, the different strategies mainly implemented for the improvement of the photocatalytic activity are considered, including different synthetic approaches, the engineering of nanostructures, the influence of phase structure, and the active species produced from heterojunctions. Photocatalytic enhancement via the surface plasmon resonance effect is also examined and the photocatalytic performance of the bismuth-based photocatalytic mechanism is elucidated and discussed in detail, considering the different semiconductor junctions. Based on recent reports, current challenges and future directions for designing and developing bismuth-based nanostructured photocatalysts for enhanced photoactivity and stability are summarized.     

KDM2A and KDM3B as Potential Targets for the Rescue of F508del-CFTR

Cystic fibrosis (CF) is caused by mutations in the gene encoding of the cystic fibrosis transmembrane conductance regulator (CFTR), an anion-selective plasma membrane channel that mainly regulates chloride transport in a variety of epithelia. More than 2000 mutations, most of which presumed to be disease-relevant, have been identified in the CFTR gene. The single CFTR mutation F508del (deletion of phenylalanine in position 508) is present in about 90% of global CF patients in at least one allele. F508del is responsible for the defective folding and processing of CFTR, failing to traffic to the plasma membrane and undergoing premature degradation via the ubiquitin–proteasome system. CFTR is subjected to different post-translational modifications (PTMs), and the possibility to modulate these PTMs has been suggested as a potential therapeutic strategy for the functional recovery of the disease-associated mutants. Recently, the PTM mapping of CFTR has identified some lysine residues that may undergo methylation or ubiquitination, suggesting a competition between these two PTMs. Our work hypothesis moves from the idea that favors methylation over ubiquitination, e.g., inhibiting demethylation could be a successful strategy for preventing the premature degradation of unstable CFTR mutants. Here, by using a siRNA library against all the human demethylases, we identified the enzymes whose downregulation increases F508del-CFTR stability and channel function. Our results show that KDM2A and KDM3B downregulation increases the stability of F508del-CFTR and boosts the functional rescue of the channel induced by CFTR correctors.