6,004 research outputs found

    Charge ordering of magnetic monopoles in triangular spin ice patterns

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    Artificial spin ice offers the possibility to investigate a variety of dipolar orderings, spin frustrations and ground states. However, the most fascinating aspect is the realization that magnetic charge order can be established without spin order. We have investigated magnetic dipoles arranged on a honeycomb lattice as a function of applied field, using magnetic force microscopy. For the easy direction with the field parallel to one of the three dipole sublattices we observe at coercivity a maximum of spin frustration and simultaneously a maximum of charge order of magnetic monopoles with alternating charges ±\pm 3.Comment: 7 pages, 4 figure

    GeMSE: A new Low-Background Facility for Meteorite and Material Screening

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    We are currently setting up a facility for low-background gamma-ray spectrometry based on a HPGe detector. It is dedicated to material screening for the XENON and DARWIN dark matter projects as well as to the characterization of meteorites. The detector will be installed in a medium depth (\sim620 m.w.e.) underground laboratory in Switzerland with several layers of shielding and an active muon-veto. The GeMSE facility will be operational by fall 2015 with an expected background rate of \sim250 counts/day (100-2700 keV).Comment: The following article appeared in AIP Conf. Proc. 1672, 120004 (2015) and may be found at http://scitation.aip.org/content/aip/proceeding/aipcp/10.1063/1.4928010. The muon spectrum in Figure 4 (left) was corrected due to a bug in the code. After correction the muon flux is reduced by a factor of about

    Therapie chronischer Wunden mit wassergefiltertem Infrarot A (wIRA)

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    The central portion of chronic wounds is often hypoxic and relatively hypothermic, representing a deficient energy supply of the tissue, which impedes wound healing or even makes it impossible. Water-filtered infrared-A (wIRA) is a special form of heat radiation with a high tissue penetration and a low thermal load to the skin surface. wIRA produces a therapeutically usable field of heat and increases temperature, oxygen partial pressure and perfusion of the tissue. These three factors are decisive for a sufficient tissue supply with energy and oxygen and consequently as well for wound healing, especially in chronic wounds, and infection defense. wIRA acts both by thermal and thermic as well as by non-thermal and non-thermic effects. wIRA can advance wound healing or improve an impaired wound healing process and can especially enable wound healing in non-healing chronic wounds. wIRA can considerably alleviate the pain and diminish wound exudation and inflammation and can show positive immunomodulatory effects. In a prospective, randomized, controlled study of 40 patients with chronic venous stasis ulcers of the lower legs irradiation with wIRA and visible light (VIS) accelerated the wound healing process (on average 18 vs. 42 days until complete wound closure, residual ulcer area after 42 days 0.4 cm² vs. 2.8 cm²) and led to a reduction of the required dose of pain medication in comparison to the control group of patients treated with the same standard care (wound cleansing, wound dressing with antibacterial gauze, and compression garment therapy) without the concomitant irradiation. Another prospective study of 10 patients with non-healing chronic venous stasis ulcers of the lower legs included extensive thermographic investigation. Therapy with wIRA(+VIS) resulted in a complete or almost complete wound healing in 7 patients and a marked reduction of the ulcer size in another 2 of the 10 patients, a clear reduction of pain and required dose of pain medication, and a normalization of the thermographic image. In a current prospective, randomized, controlled, blinded study patients with non-healing chronic venous stasis ulcers of the lower legs are treated with compression garment therapy, wound cleansing, wound dressings and 30 minutes irradiation five times per week over 9 weeks. A preliminary analysis of the first 23 patients of this study has shown in the group with wIRA(+VIS) compared to a control group with VIS an advanced wound healing, an improved granulation and in the later phase of treatment a decrease of the bacterial burden. Some case reports have demonstrated that wIRA can also be used for mixed arterial-venous ulcers or arterial ulcers, if irradiation intensity is chosen appropriately low and if irradiation is monitored carefully. wIRA can be used concerning decubital ulcers both in a preventive and in a therapeutic indication. wIRA can improve the resorption of topically applied substances also on wounds. An irradiation with VIS and wIRA presumably acts with endogenous protoporphyrin IX (or protoporphyrin IX of bacteria) virtually similar as a mild photodynamic therapy (endogenous PDT-like effect). This could lead to improved cell regeneration and wound healing and to antibacterial effects. In conclusion, these results indicate that wIRA generally should be considered for the treatment of chronic wounds.Das Zentrum von chronischen Wunden ist oft hypoxisch und relativ hypotherm. Dies entspricht einer defizitären Energiebereitstellung im Gewebe, die die Wundheilung behindert oder unmöglich macht. Wassergefiltertes Infrarot A (wIRA) ist eine spezielle Form der Wärmestrahlung mit hohem Eindringvermögen in das Gewebe bei geringer thermischer Oberflächenbelastung. wIRA erzeugt ein therapeutisch nutzbares Wärmefeld und steigert Temperatur, Sauerstoffpartialdruck sowie die Durchblutung im Gewebe. Diese drei Faktoren sind entscheidend für eine ausreichende Versorgung des Gewebes mit Energie und Sauerstoff und deshalb auch für die Wundheilung, speziell bei chronischen Wunden, und die Infektionsabwehr. wIRA wirkt sowohl über thermische und temperaturabhängige als auch über nicht-thermische und temperaturunabhängige Effekte. wIRA kann die Wundheilung beschleunigen oder einen stagnierenden Wundheilungsprozess verbessern und insbesondere bei nicht-heilenden chronischen Wunden eine Wundheilung ermöglichen. wIRA vermag Schmerzen deutlich zu mindern und die Wundsekretion sowie Entzündung zu reduzieren sowie positive immunmodulierende Effekte zu zeigen. In einer prospektiven, randomisierten, kontrollierten Studie mit 40 Patienten mit chronischen venösen Unterschenkelulzera führte eine Bestrahlung mit wIRA und sichtbarem Licht (VIS) zu einer schnelleren Wundheilung (im Durchschnitt 18 vs. 42 Tage bis zum kompletten Wundschluss, Restulkusfläche nach 42 Tagen 0,4 cm² vs. 2,8 cm²) und einem geringeren Schmerzmittelverbrauch gegenüber einer in gleicher Form (Wundsäuberung, antibakterielle Wundauflagen und Kompressionstherapie) therapierten, aber nicht bestrahlten Kontrollgruppe. Eine weitere prospektive Studie mit 10 Patienten mit aufwändiger thermographischer Verlaufskontrolle ergab unter Therapie mit wIRA(+VIS) eine vollständige oder fast vollständige Abheilung therapierefraktärer chronischer Unterschenkelulzera bei 7 sowie eine deutliche Ulkusverkleinerung bei 2 weiteren der 10 Patienten, eine ausgeprägte Minderung der Schmerzen und des Schmerzmittelverbrauchs und eine Normalisierung des thermographischen Bildes. In einer laufenden prospektiven, randomisierten, kontrollierten, verblindeten Studie werden Patienten mit nicht-heilenden chronischen venösen Unterschenkelulzera mit Kompressionstherapie, Wundsäuberung und nicht-adhäsiven Wundauflagen sowie 30 Minuten Bestrahlung fünfmal pro Woche über 9 Wochen behandelt. Eine vorläufige Auswertung der ersten 23 Patienten zeigte, dass die Gruppe mit wIRA(+VIS) verglichen mit einer Kontrollgruppe mit VIS eine schnellere Wundheilung, eine bessere Granulation und in der späteren Phase der Behandlung eine Abnahme der bakteriellen Last der Wunden aufwies. Einige Fallberichte haben gezeigt, dass wIRA selbst bei gemischt arteriell-venösen Ulzera oder arteriellen Ulzera eingesetzt werden kann, wenn die Bestrahlungsstärke angemessen niedrig gewählt und die Bestrahlung sorgfältig überwacht wird. wIRA kann bei Dekubitalulzera sowohl präventiv als auch therapeutisch eingesetzt werden. wIRA kann die Resorption topisch applizierter Substanzen auch auf Wunden verbessern. Eine Bestrahlung mit VIS und wIRA wirkt vermutlich in Verbindung mit endogenem Protoporphyrin IX (oder Protoporphyrin IX von Bakterien) quasi ähnlich wie eine milde photodynamische Therapie (endogener PDT-ähnlicher Effekt). Dies kann die Zellregeneration und Wundheilung fördern und antibakteriell wirken. Zusammengefasst zeigen die Ergebnisse, dass wIRA generell für die Behandlung chronischer Wunden erwogen werden sollte

    Sequential epiretinal membrane removal with internal limiting membrane peeling in brilliant blue G-assisted macular surgery

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    Purpose To assess the selectivity of brilliant blue G (BBG) staining by analysing the morphological components of unstained and stained tissue obtained during epiretinal membrane (ERM) removal with internal limiting membrane (ILM) peeling in BBG-assisted macular surgery. Methods Twenty-six surgical specimens were removed from 13 eyes with epiretinal gliosis during vitrectomy using BBG for ERM and ILM peeling. We included eyes with idiopathic macular pucker, idiopathic macular hole and vitreomacular traction syndrome. The dye was injected into the fluid-filled globe. Unstained and stained epiretinal tissue was harvested consecutively and placed into separate containers. All specimens were processed for conventional transmission electron microscopy. Results The first surgical specimen of all eyes showed no intraoperative staining with BBG and corresponded to masses of cells and collagen. The second surgical specimen demonstrated good staining characteristics and corresponded to the ILM in all patients included. In seven eyes, the ILM specimens were seen with minor cell proliferations such as single cells or a monolayer of cells. Myofibroblasts, fibroblasts and astrocytes were present. In five cases, native vitreous collagen fibrils were found at the ILM. In six of the eyes, ILM specimens were blank. Conclusion Our clinicopathological correlation underlines the selective staining properties of BBG. The residual ILM is selectively stained by BBG even when a small amount of cells and collagen adheres to its vitreal side. To reduce the retinal exposure to the dye, the surgeon might choose to remove the ERM without using the dye, followed by a BBG injection to identify residual ILM

    Generating orthogonal glycosyltransferase and nucleotide sugar pairs as next-generation glycobiology tools

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    Protein glycosylation fundamentally impacts biological processes. Nontemplated biosynthesis introduces unparalleled complexity into glycans that needs tools to understand their roles in physiology. The era of quantitative biology is a great opportunity to unravel these roles, especially by mass spectrometry glycoproteomics. However, with high sensitivity come stringent requirements on tool specificity. Bioorthogonal metabolic labeling reagents have been fundamental to studying the cell surface glycoproteome but typically enter a range of different glycans and are thus of limited specificity. Here, we discuss the generation of metabolic 'precision tools' to study particular subtypes of the glycome. A chemical biology tactic termed bump-and-hole engineering generates mutant glycosyltransferases that specifically accommodate bioorthogonal monosaccharides as an enabling technique of glycobiology. We review the groundbreaking discoveries that have led to applying the tactic in the living cell and the implications in the context of current developments in mass spectrometry glycoproteomics

    Assessing the relationship between terrorist attacks against ingroup or outgroup members and public support for terrorism

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    Terrorist groups rely on constituency support for their long-term survival. Here, we examined the extent to which terrorists’ own activities are related with public opinion on terrorism. Specifically, we assessed whether more frequent and more costly terrorist attacks against the ingroup are associated with war weariness or retaliatory sentiments, thus, either weaker or stronger approval of terrorism. We further investigated if more frequent and costly attacks that target an outgroup predict higher levels of justification of terrorism. Lastly, we identified the timeframe during which domestic and outgroup terrorist attacks correlate with (lower or higher) public support. The analyses focused on Jordan (ingroup) and Israel (outgroup), over an 8-year period (2004–2011), drawing on data from the Pew Global Attitudes Survey and the Global Terrorism Database. Results showed that support for terrorism in Jordan decreased in 2005 and, again, in 2008. The frequency of terrorist attacks and fatality/injury rates in Jordan did not vary significantly during the study period. The number of attacks and fatalities/people injured in Israel, however, changed between 2004 and 2011. Cross-correlations of the time-series further demonstrated that the number of attacks and fatalities/people injured in Jordan was not related with the level of public approval of terrorism in the country. Importantly, and in line with the literature, the casualty rate in Israel was positively associated with support for terrorism in Jordan, in the next year. That is, there is evidence that more/less costly terrorist attacks on an outgroup can predict stronger/weaker public support for the tactic relatively quickly. Those findings provide insights for counter-terrorism measures

    Interactions between KSHV ORF57 and the novel human TREX proteins, CHTOP and CIP29

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    The coupling of mRNA processing steps is essential for precise and efficient gene expression. The human transcription/export (hTREX) complex is a highly conserved multi-protein complex responsible for eukaryotic mRNA stability and nuclear export. We have previously shown that the Kaposi's sarcoma-associated ORF57 protein orchestrates the recruitment of the hTREX complex onto viral intronless mRNA forming a stable and export competent viral ribonucleoprotein particle (vRNP). Recently, additional cellular proteins, namely CHTOP, CIP29 and POLDIP3 have been proposed as novel hTREX components. Herein we extend our previous research and provide evidence that ORF57 interacts with CHTOP and CIP29, in contrast to POLDIP3. Moreover, depletion studies show both CHTOP and CIP29 effect ORF57-mediated viral mRNA processing. As such, these results suggest both CHTOP and CIP29 are hTREX components and are recruited to an ORF57-mediated vRNP

    Increasing the performance of the superconducting spin valve using a Heusler alloy

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    We have studied superconducting properties of the spin-valve thin layer heterostructures CoOx_x/F1/Cu/F2/Cu/Pb where the ferromagnetic F1 layer was standardly made of Permalloy whereas for the F2 layer we have taken a specially prepared film of the Heusler alloy Co2_2Cr1x_{1-x}Fex_xAl with a small degree of spin polarization of the conduction band. The heterostructures demonstrate a significant superconducting spin-valve effect, i.e. a complete switching on and off of the superconducting current flowing through the system by manipulating the mutual orientations of the magnetization of the F1 and F2 layers. The magnitude of the effect is doubled in comparison with the previously studied analogous multilayers with the F2 layer made of the strong ferromagnet Fe. Theoretical analysis shows that a drastic enhancement of the switching effect is due to a smaller exchange field in the heterostructure coming from the Heusler film as compared to Fe. This enables to approach almost ideal theoretical magnitude of the switching in the Heusler-based multilayer with the F2 layer thickness of 1\sim 1\,nm
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