Tunneling Anisotropic Spin Polarization in lateral (Ga,Mn)As/GaAs spin Esaki diode devices

We report here on anisotropy of spin polarization obtained in lateral all-semiconductor all-electrical spin injection devices, employing $p^{+}-$(Ga,Mn)As/$n^{+}-$GaAs Esaki diode structures as spin aligning contacts, resulting from the dependence of the efficiency of spin tunneling on the orientation of spins with respect to different crystallographic directions. We observed an in-plane anisotropy of $~8$ in case of spins oriented either along $[1\bar{1}0]$ or $[110]$ directions and $~25$ anisotropy between in-plane and perpendicular-to-plane orientation of spins.Comment: 9 pages, 3 figure

Magnetic anisotropy of epitaxial (Ga,Mn)As on (113)A GaAs

The temperature dependence of magnetic anisotropy in (113)A (Ga,Mn)As layers grown by molecular beam epitaxy is studied by means of superconducting quantum interference device (SQUID) magnetometry as well as by ferromagnetic resonance (FMR) and magnetooptical effects. Experimental results are described considering cubic and two kinds of uniaxial magnetic anisotropy. The magnitude of cubic and uniaxial anisotropy constants is found to be proportional to the fourth and second power of saturation magnetization, respectively. Similarly to the case of (001) samples, the spin reorientation transition from uniaxial anisotropy with the easy along the [-1, 1, 0] direction at high temperatures to the biaxial anisotropy at low temperatures is observed around 25 K. The determined values of the anisotropy constants have been confirmed by FMR studies. As evidenced by investigations of the polar magnetooptical Kerr effect, the particular combination of magnetic anisotropies allows the out-of-plane component of magnetization to be reversed by an in-plane magnetic field. Theoretical calculations within the p-d Zener model explain the magnitude of the out-of-plane uniaxial anisotropy constant caused by epitaxial strain, but do not explain satisfactorily the cubic anisotropy constant. At the same time the findings point to the presence of an additional uniaxial anisotropy of unknown origin. Similarly to the case of (001) films, this additional anisotropy can be explained by assuming the existence of a shear strain. However, in contrast to the (001) samples, this additional strain has an out-of-the-(001)-plane character.Comment: 13 pages, 9 figure

Imaging ellipsometry of graphene

Imaging ellipsometry studies of graphene on SiO2/Si and crystalline GaAs are presented. We demonstrate that imaging ellipsometry is a powerful tool to detect and characterize graphene on any flat substrate. Variable angle spectroscopic ellipsometry is used to explore the dispersion of the optical constants of graphene in the visible range with high lateral resolution. In this way the influence of the substrate on graphene's optical properties can be investigatedComment: 3 pages, 3 figure

Treiber und Barrieren auf dem Weg zu einer Smart City : Erkenntnisse aus Theorie und Praxis

Städte nehmen eine Schlüsselrolle in der Umsetzung der Energiestrategie 2050 («Energiewende») ein. Einerseits steigt der Energieverbrauch von Städten infolge der Urbanisierung, welche als einer der wichtigsten globalen Trends angesehen wird, weiter an. Andererseits haben Städte durch die vorhandene Infrastruktur mehrere Möglichkeiten, sich aktiv für die Energiewende einzusetzen. Zudem können Städte durch ihre Vorbildfunktion in den Bereichen Energieversorgung, Mobilität, Arealentwicklung oder bei der Sanierung von Gebäuden wichtige Impulse setzen. Städte stehen in enger Beziehung und Abhängigkeit zu Wirtschaft und Bevölkerung. Sie können Rahmenbedingungen schaffen, welche diese Akteure zu Energieeffizienz oder -suffizienz motivieren. Das Konzept Smart City birgt vielfältige Möglichkeiten, durch intelligente Vernetzung von Handlungsbereichen bessere Bedingungen für eine nachhaltige und moderne Stadtentwicklung zu schaffen. Mit dem integrativen Ansatz soll die Lebensqualität der Bewohnerinnen und Bewohner einer Stadt erhöht und die Mitwirkung relevanter Anspruchsgruppen ermöglicht werden. Gleichzeitig wird eine Reduktion des Energie- und Ressourcenverbrauchs in Städten angestrebt. Smart City ist daher als Lösungsansatz für die zukünftigen Herausforderungen in Städten zu verstehen. In der Schweiz wurde das Konzept allerdings bisher erst in wenigen Städten im Rahmen von einzelnen Projekten berücksichtigt und angewandt. In diesem Working Paper wird der Frage nach den Barrieren und Treibern innerhalb der Transformationsprozesse zu einer Smart City und den vordringlichen Handlungsfeldern mit ihren Akteuren nachgegangen. Auf der Grundlage einer Literatur-Studie zu Forschungs- und Praxisansätzen, einer mehrstufigen Delphi-Befragung von Schweizer Experten zu Smart Cities 2035 sowie der Teilnahme an konkreten «Smart City Winterthur»-Teilprojekten, welche in den Jahren 2014-2015 durchgeführt wurden, wurden Treiber und Barrieren identifiziert und daraus weiterer Handlungs- und Forschungsbedarf abgeleitet. Als wesentliche Treiber für die Umsetzung von Smart-City-Konzepten sind sowohl die Zusammenarbeit relevanter Akteure, die Förderung von Pilot- als auch das Aufzeigen von konkreten Smart-City-Projekten identifiziert worden, die kosten- und ressourceneffizienter sind. Damit sollen Investoren und Unternehmen zur Unterstützung solcher Projekte motiviert werden. Fehlende politische und rechtliche Rahmenbedingungen sowie die vertikalen, städtischen Verwaltungsstrukturen wirken beim integrativen Ansatz des Smart-City-Konzepts als Barrieren. Zukünftige Smart-City-Projekte sollten den Einbezug der Bevölkerung stärker berücksichtigen, insbesondere bei der Verwendung von Daten. Nebst praxisbezogenen Empfehlungen werden Hinweise zum Forschungsbedarf in der Thematik genannt

Enhanced Recovery after Intensive Care (ERIC): study protocol for a German stepped wedge cluster randomised controlled trial to evaluate the effectiveness of a critical care telehealth program on process quality and functional outcome

Introduction: Survival after critical illness has noticeably improved over the last decades due to advances in critical care medicine. Besides, there is an increasing number of elderly patients with chronic diseases being treated in the intensive care unit (ICU). More than half of the survivors of critical illness suffer from medium-term or long-term cognitive, psychological and/or physical impairments after ICU discharge, which is recognised as post-intensive care syndrome (PICS). There are evidence-based and consensus-based quality indicators (QIs) in intensive care medicine, which have a positive influence on patients' long-term outcomes if adhered to. Methods and analysis: The protocol of a multicentre, pragmatic, stepped wedge cluster randomised controlled, quality improvement trial is presented. During 3 predefined steps, 12 academic hospitals in Berlin and Brandenburg, Germany, are randomly selected to move in a one-way crossover from the control to the intervention condition. After a multifactorial training programme on QIs and clinical outcomes for site personnel, ICUs will receive an adapted, interprofessional protocol for a complex telehealth intervention comprising of daily telemedical rounds at ICU. The targeted sample size is 1431 patients. The primary objective of this trial is to evaluate the effectiveness of the intervention on the adherence to eight QIs daily measured during the patient's ICU stay, compared with standard of care. Furthermore, the impact on long-term recovery such as PICS-related, patient-centred outcomes including health-related quality of life, mental health, clinical assessments of cognition and physical function, all-cause mortality and cost-effectiveness 3 and 6 months after ICU discharge will be evaluated. Ethics and dissemination: This protocol was approved by the ethics committee of the Charité-Universitätsmedizin, Berlin, Germany (EA1/006/18). The results will be published in a peer-reviewed scientific journal and presented at international conferences. Study findings will also be disseminated via the website (www.eric-projekt.net). Trial registration number: ClinicalTrials.gov Registry (NCT03671447)

Colony organization in the green alga Botryococcus braunii (Race B) is specified by a complex extracellular matrix

Botryococcus braunii is a colonial green alga whose cells associate via a complex extracellular matrix (ECM) and produce prodigious amounts of liquid hydrocarbons that can be readily converted into conventional combustion engine fuels. We used quick-freeze deep-etch electron microscopy and biochemical/histochemical analysis to elucidate many new features of B. braunii cell/colony organization and composition. Intracellular lipid bodies associate with the chloroplast and endoplasmic reticulum (ER) but show no evidence of being secreted. The ER displays striking fenestrations and forms a continuous subcortical system in direct contact with the cell membrane. The ECM has three distinct components. (i) Each cell is surrounded by a fibrous β-1, 4- and/or β-1, 3-glucan-containing cell wall. (ii) The intracolonial ECM space is filled with a cross-linked hydrocarbon network permeated with liquid hydrocarbons. (iii) Colonies are enclosed in a retaining wall festooned with a fibrillar sheath dominated by arabinose-galactose polysaccharides, which sequesters ECM liquid hydrocarbons. Each cell apex associates with the retaining wall and contributes to its synthesis. Retaining-wall domains also form “drapes” between cells, with some folding in on themselves and penetrating the hydrocarbon interior of a mother colony, partitioning it into daughter colonies. We propose that retaining-wall components are synthesized in the apical Golgi apparatus, delivered to apical ER fenestrations, and assembled on the surfaces of apical cell walls, where a proteinaceous granular layer apparently participates in fibril morphogenesis. We further propose that hydrocarbons are produced by the nonapical ER, directly delivered to the contiguous cell membrane, and pass across the nonapical cell wall into the hydrocarbon-based ECM

The first trimester human trophoblast cell line ACH-3P: A novel tool to study autocrine/paracrine regulatory loops of human trophoblast subpopulations – TNF-α stimulates MMP15 expression

<p>Abstract</p> <p>Background</p> <p>The trophoblast compartment of the placenta comprises various subpopulations with distinct functions. They interact among each other by secreted signals thus forming autocrine or paracrine regulatory loops. We established a first trimester trophoblast cell line (ACH-3P) by fusion of primary human first trimester trophoblasts (week 12 of gestation) with a human choriocarcinoma cell line (AC1-1).</p> <p>Results</p> <p>Expression of trophoblast markers (cytokeratin-7, integrins, matrix metalloproteinases), invasion abilities and transcriptome of ACH-3P closely resembled primary trophoblasts. Morphology, cytogenetics and doubling time was similar to the parental AC1-1 cells. The different subpopulations of trophoblasts e.g., villous and extravillous trophoblasts also exist in ACH-3P cells and can be immuno-separated by HLA-G surface expression. HLA-G positive ACH-3P display pseudopodia and a stronger expression of extravillous trophoblast markers. Higher expression of insulin-like growth factor II receptor and human chorionic gonadotropin represents the basis for the known autocrine stimulation of extravillous trophoblasts.</p> <p>Conclusion</p> <p>We conclude that ACH-3P represent a tool to investigate interaction of syngeneic trophoblast subpopulations. These cells are particularly suited for studies into autocrine and paracrine regulation of various aspects of trophoblast function. As an example a novel effect of TNF-α on matrix metalloproteinase 15 in HLA-G positive ACH-3P and explants was found.</p

Gold nanoparticles (AuNPs) impair LPS-driven immune responses by promoting a tolerogenic-like dendritic cell phenotype with altered endosomal structures

Dendritic cells (DCs) shape immune responses by influencing T-cell activation. Thus, they are considered both an interesting model for studying nano-immune interactions and a promising target for nano-based biomedical applications. However, the accentuated ability of nanoparticles (NPs) to interact with biomolecules may have an impact on DC function that poses an unexpected risk of unbalanced immune reactions. Here, we investigated the potential effects of gold nanoparticles (AuNPs) on DC function and the consequences for effector and memory T-cell responses in the presence of the microbial inflammatory stimulus lipopolysaccharide (LPS). Overall, we found that, in the absence of LPS, none of the tested NPs induced a DC response. However, whereas 4-, 8-, and 11 nm AuNPs did not modulate LPS-dependent immune responses, 26 nm AuNPs shifted the phenotype of LPS-activated DCs toward a tolerogenic state, characterized by downregulation of CD86, IL-12 and IL-27, upregulation of ILT3, and induction of class E compartments. Moreover, this DC phenotype was less proficient in promoting Th1 activation and central memory T-cell proliferation. Taken together, these findings support the perception that AuNPs are safe under homeostatic conditions; however, particular care should be taken in patients experiencing a current infection or disorders of the immune system

The path to triacylglyceride obesity in the sta6 strain of Chlamydomonas reinhardtii

When the sta6 (starch-null) strain of the green microalga Chlamydomonas reinhardtii is nitrogen starved in acetate and then “boosted” after 2 days with additional acetate, the cells become “obese” after 8 days, with triacylglyceride (TAG)-filled lipid bodies filling their cytoplasm and chloroplasts. To assess the transcriptional correlates of this response, the sta6 strain and the starch-forming cw15 strain were subjected to RNA-Seq analysis during the 2 days prior and 2 days after the boost, and the data were compared with published reports using other strains and growth conditions. During the 2 h after the boost, ∼425 genes are upregulated ≥2-fold and ∼875 genes are downregulated ≥2-fold in each strain. Expression of a small subset of “sensitive” genes, encoding enzymes involved in the glyoxylate and Calvin-Benson cycles, gluconeogenesis, and the pentose phosphate pathway, is responsive to culture conditions and genetic background as well as to boosting. Four genes—encoding a diacylglycerol acyltransferase (DGTT2), a glycerol-3-P dehydrogenase (GPD3), and two candidate lipases (Cre03.g155250 and Cre17.g735600)—are selectively upregulated in the sta6 strain. Although the bulk rate of acetate depletion from the medium is not boost enhanced, three candidate acetate permease-encoding genes in the GPR1/FUN34/YaaH superfamily are boost upregulated, and 13 of the “sensitive” genes are strongly responsive to the cell's acetate status. A cohort of 64 autophagy-related genes is downregulated by the boost. Our results indicate that the boost serves both to avert an autophagy program and to prolong the operation of key pathways that shuttle carbon from acetate into storage lipid, the combined outcome being enhanced TAG accumulation, notably in the sta6 strain