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In this study, we investigate the spin Hall effect in heterostructures of Bi0.85Sb0.15 (10 nm) topological insulator/Ru(Ti)/Ta/Co20Fe60B20/MgO with perpendicular magnetic anisotropy. By optimizing the Ru (Ti) interfacial layer thickness as well as deposition condition of BiSb, we achieve a large effective spin Hall angle of 6.0 ± 0.1 and relatively high electrical conductivity of 1.5 × 105 Ω−1 m−1 at room temperature. We, then, demonstrate spin–orbit torque-induced magnetization switching driven by a small threshold current density of 1 × 106 Acm−2. Benchmarking shows that the writing power consumption of our stack is 2–3 orders smaller than that of heavy metals. [ABSTRACT FROM AUTHOR]

It has been shown that Escherichia coli cells with increased expression of the rpoE gene encoding [[sigma].sup.E] exhibit enhanced cell lysis in early stationary phase. Further analysis of the lysis phenomenon was performed using a transient expression system of the rpoE gene and by DNA microarray. The former analysis revealed a [[sigma].sup.E]-directed cell lysis, specific for early stationary phase but not for the exponential phase. The microarray analysis with RNAs from exponential and early stationary phase cells revealed that a large number of genes were up-or down-regulated when the rpoE gene was induced, and that several genes were induced in a phase-specific manner. The upregulated genes include many previously identified [[sigma].sup.E] regulon genes, suggesting that a large number of genes are under the control of [[sigma].sup.E] in this organism. These genes are involved in various cellular activities, including the cell envelope, cellular processes, regulatory functions, transport and translation. Genes that are presumably related to phase-specific cell lysis in E. coli are discussed.

Research has been conducted on Escherichia coli protein YibP involving amino acid sequences. The properties of the yibP disrupted mutant cells and subcellular localization of the YibP protein have been investigated and the results are reported.

We used a micromagnetic model to study the head remanence of a perpendicular tapered main pole head. To reduce the head pole tip remanence, a single magnetic domain structure forming a vortex state from the pole tip to the tapered region is preferred. A tapered main pole structure with a trailing gap depth less than about 30 nm and a tapered angle (TGθ) equal to about 30° improved the writing efficiency. This was achieved with a head field value more than 1.3 times higher and with a head field gradient about 1.15 times higher than that of the conventional structure. Moreover, the pole tip remanence was reduced to a value closer to that of the conventional structure. The reduction in the throat height had less effect on the reduction in the head remanence in the tapered head than in the conventional head. We also discuss both single pole heads and shielded heads. [ABSTRACT FROM AUTHOR]

Hybrid lead halide perovskites have emerged as promising active materials for photovoltaic cells. Although superb efficiencies have been achieved, it is widely recognized that long-term stability is a key challenge intimately determining the future development of perovskite-based photovoltaic technology. Herein, we present reversible and irreversible photodecomposition reactions of methylammonium lead iodide (MAPbI3). Simulated sunlight irradiation and temperature (40–80 °C) corresponding to solar cell working conditions lead to three degradation pathways: (1) CH3NH2 + HI (identified as the reversible path), (2) NH3 + CH3I (the irreversible or detrimental path), and (3) a reversible Pb(0) + I2(g) photodecomposition reaction. If only the reversible reactions EQNREF(1)/EQNREF and EQNREF(3)/EQNREF take place and reaction EQNREF(2)/EQNREF can be avoided, encapsulated MAPbI3 can be regenerated during the off-illumination timeframe. Therefore, to further improve operational stability in hybrid perovskite solar cells, detailed understanding of how to mitigate photodegradation and thermal degradation processes is necessary. First, encapsulation of the device is necessary not only to avoid contact of the perovskite with ambient air, but also to prevent leakage of volatile products released from the perovskite. Second, careful selection of the organic cations in the compositional formula of the perovskite is necessary to avoid irreversible reactions. Third, selective contacts must be as chemically inert as possible toward the volatile released products. Finally, hybrid halide perovskite materials are speculated to undergo a dynamic formation and decomposition process; this can gradually decrease the crystalline grain size of the perovskite with time; therefore, efforts to deposit highly crystalline perovskites with large crystal sizes may fail to increase the long-term stability of photovoltaic devices. [ABSTRACT FROM AUTHOR]

Ribosomes routinely prepared from Escherichia coli strain K12 contain intact (70 amino acids) and short (62 amino acids) forms of ribosomal protein L31. By contrast, ribosomes prepared from ompT mutant cells, which lack protease 7, contain only intact L31, suggesting that L31 is cleaved by protease 7 during ribosome preparation. We compared ribosomal subunit association in wild-type and ompT − strains. In sucrose density gradient centrifugation under low Mg2+, 70S content was very high in ompT − ribosomes, but decreased in the wild-type ribosomes containing short L31. In addition, ribosomes lacking L31 failed to associate ribosomal subunits in low Mg2+. Therefore, intact L31 is required for subunit association, and the eight C-terminal amino acids contribute to the association function. In vitro translation was assayed using three different systems. Translational activities of ribosomes lacking L31 were 40% lower than those of ompT − ribosomes with one copy of intact L31, indicating that L31 is involved in translation. Moreover, in the stationary phase, L31 was necessary for 100S formation. The strain lacking L31 grew very slowly. A structural analysis predicted that the L31 protein spans the 30S and 50S subunits, consistent with the functions of L31 in 70S association, 100S formation, and translation. [ABSTRACT FROM AUTHOR]

Background: Hepatocellular carcinoma (HCC), the fifth most common cancer type and the third highest cause of cancer death worldwide, develops in different types of liver injuries, and is mostly associated with cirrhosis. However, non-alcoholic fatty liver disease often causes HCC with less fibrosis, and the number of patients with this disease is rapidly increasing. The high mortality rate and the pathological complexity of liver diseases and HCC require blood biomarkers that accurately reflect the state of liver damage and presence of HCC. Methods and Findings: Here we demonstrate that a circulating protein, apoptosis inhibitor of macrophage (AIM) may meet this requirement. A large-scale analysis of healthy individuals across a wide age range revealed a mean blood AIM of 4.99±1.8 µg/ml in men and 6.06±2.1 µg/ml in women. AIM levels were significantly augmented in the younger generation (20s–40s), particularly in women. Interestingly, AIM levels were markedly higher in patients with advanced liver damage, regardless of disease type, and correlated significantly with multiple parameters representing liver function. In mice, AIM levels increased in response to carbon tetrachloride, confirming that the high AIM observed in humans is the result of liver damage. In addition, carbon tetrachloride caused comparable states of liver damage in AIM-deficient and wild-type mice, indicating no influence of AIM levels on liver injury progression. Intriguingly, certain combinations of AIM indexes normalized to liver marker score significantly distinguished HCC patients from non-HCC patients and thus could be applicable for HCC diagnosis. Conclusion: AIM potently reveals both liver damage and HCC. Thus, our results may provide the basis for novel diagnostic strategies for this widespread and fatal disease. [ABSTRACT FROM AUTHOR]

In yeast, C-tail-anchored mitochondrial outer membrane protein Fis1 recruits the mitochondrial-fission-regulating GTPase Dnm1 to mitochondrial fission sites. However, the function of its mammalian homologue remains enigmatic because it has been reported to be dispensable for the mitochondrial recruitment of Drp1, a mammalian homologue of Dnm1. We identified TBC1D15 as a Fis1-binding protein in HeLa cell extracts. Immunoprecipitation revealed that Fis1 efficiently interacts with TBC1D15 but not with Drp1. Bacterially expressed Fis1 and TBC1D15 formed a direct and stable complex. Exogenously expressed TBC1D15 localized mainly in cytoplasm in HeLa cells, but when coexpressed with Fis1 it localized to mitochondria. Knockdown of TBC1D15 induced highly developed mitochondrial network structures similar to the effect of Fis1 knockdown, suggesting that the TBC1D15 and Fis1 are associated with the regulation of mitochondrial morphology independently of Drp1. These data suggest that Fis1 acts as a mitochondrial receptor in the recruitment of mitochondrial morphology protein in mammalian cells. [ABSTRACT FROM AUTHOR]

Mitochondrial morphology is dynamically controlled by a balance between fusion and fission. The physiological importance of mitochondrial fission in vertebrates is less clearly defined than that of mitochondrial fusion. Here we show that mice lacking the mitochondrial fission GTPase Drp1 have developmental abnormalities, particularly in the forebrain, and die after embryonic day 12.5. Neural cell-specific (NS) Drp1−/− mice die shortly after birth as a result of brain hypoplasia with apoptosis. Primary culture of NS-Drp1−/− mouse forebrain showed a decreased number of neurites and defective synapse formation, thought to be due to aggregated mitochondria that failed to distribute properly within the cell processes. These defects were reflected by abnormal forebrain development and highlight the importance of Drp1-dependent mitochondrial fission within highly polarized cells such as neurons. Moreover, Drp1−/− murine embryonic fibroblasts and embryonic stem cells revealed that Drp1 is required for a normal rate of cytochrome c release and caspase activation during apoptosis, although mitochondrial outer membrane permeabilization, as examined by the release of Smac/Diablo and Tim8a, may occur independently of Drp1 activity. [ABSTRACT FROM AUTHOR]

In order to find molecules affected by administration of an antipsychotic drug with an antimuscarinic drug, which is a common prescription used to prevent extrapyramidal adverse effects caused by the antipsychotic drugs, gene expression profiling in the frontal cortex was studied in mice. After 14 days of administration with 2 mg/kg haloperidol, a typical antipsychotic drug, and 2 mg/kg biperiden, a high-affinity antagonist for muscarinic receptors in the brain, ∼500 mRNAs related to synaptic function were investigated. The levels of the mRNAs related to the ubiquitin-related systems were significantly reduced after the combined administration. However, the separate administration of either haloperidol or biperiden had little effect on the levels of the mRNAs. This result suggests that coadministration of haloperidol and biperiden specifically affects the ubiquitin-related system. Synapse 56:175-184, 2005. © 2005 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]

To achieve industrially viable fabrication process for perovskite-based solar cells, every process step must be optimized for maximum throughput. We present a study of substituting laboratory-type UV-Ozone surface treatment with a high-throughput Corona treatment in a scalable perovskite solar cell fabrication process. It is observed that water contact angle measurements provide insufficient information to determine the necessary dose of Corona or UV-Ozone treatment, but the surface carbon signal measured by x-ray photoelectron spectroscopy accurately identifies when surface contamination has been completely removed. Furthermore, we observe highly accelerated de-contamination of ZnO surfaces by UV-Ozone treatment. The effect can be explained by photocatalytic O 2 − ion generation indicating that UV-Ozone treatment is also applicable in high-throughput processing. [ABSTRACT FROM AUTHOR]

Protein--protein interactions play key roles in protein function and the structural organization of a cell. A thorough description of these interactions should facilitate elucidation of cellular activities, targeted-drug design, and whole cell engineering. A large-scale comprehensive pull-down assay was performed using a His-tagged Escherichia coli ORF clone library. Of 4339 bait proteins tested, partners were found for 2667, including 779 of unknown function. Proteins copurifying with hexahistidine-tagged baits on a Ni2+-NTA column were identified by MALDI-TOF MS (matrix-assisted laser desorption ionization time of flight mass spectrometry). An extended analysis of these interacting networks by bioinformatics and experimentation should provide new insights and novel strategies for E. coli systems biology. [ABSTRACT FROM AUTHOR]

Summary Mitochondria are dynamic organelles that change their morphology by active fusion and fission in response to cellular signaling and differentiation [ 1, 2 ]. The in vivo role of mitochondrial fission in mammals has been examined by using tissue-specific knockout (KO) mice of the mitochondria fission-regulating GTPase Drp1 [ 3, 4 ], as well as analyzing a human patient harboring a point mutation in Drp1 [ 5 ], showing that Drp1 is essential for embryonic and neonatal development and neuronal function. During oocyte maturation and aging, structures of various membrane organelles including mitochondria and the endoplasmic reticulum (ER) are changed dynamically [ 6, 7 ], and their organelle aggregation is related to germ cell formation and epigenetic regulation [ 8–10 ]. However, the underlying molecular mechanisms of organelle dynamics during the development and aging of oocytes have not been well understood. Here, we analyzed oocyte-specific mitochondrial fission factor Drp1-deficient mice and found that mitochondrial fission is essential for follicular maturation and ovulation in an age-dependent manner. Mitochondria were highly aggregated with other organelles, such as the ER and secretory vesicles, in KO oocyte, which resulted in impaired Ca 2+ signaling, intercellular communication via secretion, and meiotic resumption. We further found that oocytes from aged mice displayed reduced Drp1-dependent mitochondrial fission and defective organelle morphogenesis, similar to Drp1 KO oocytes. On the basis of these findings, it appears that mitochondrial fission maintains the competency of oocytes via multiorganelle rearrangement. [ABSTRACT FROM AUTHOR]

It has been shown that Escherichia coil cells with increased expression of the rpoE gene encoding αE exhibit enhanced cell lysis in early stationary phase. Further analysis of the lysis phenomenon was performed using a transient expression system of the rpoE gene and by DNA microarray. The former analysis revealed a αE directed cell lysis, specific for early stationary phase but not for the exponential phase. The microarray analysis with RNAs from exponential and early stationary phase cells revealed that a large number of genes were up- or down-regulated when the rpoE gene was induced, and that several genes were induced in a phase-specific manner. The upregulated genes include many previously identified αE regulon genes. suggesting that a large number of genes are tinder the control of αE in this organism. These genes are involved in various cellular activities, including the cell envelope, cellular processes, regulatory functions, transport and translation. Genes that are presumably related to phase-specific cell lysis in E. coli are discussed. [ABSTRACT FROM AUTHOR]