Ba2AlSi5N9

Ba2AlSi5N9 was synthesized starting from Si3N4, AlN, and Ba in a radio-frequency furnace at temperatures of about 1725°C. The new nitridoalumosilicate crystallizes in the triclinic space group P1 (no. 1), a=9.860(1) Å, b=10.320(1) Å, c=10.346(1) Å, α=90.37(2)°, β=118.43(2)°; γ=103.69(2)°, Z=4, R1=0.0314. All synthesized crystals were characteristically twinned by reticular pseudomerohedry with twin law (1 0 0, −0.5 −1 0, −1 0 −1). The crystal structure of Ba2AlSi5N9 was determined from single-crystal X-ray diffraction data of a twinned crystal and confirmed by Rietveld refinement both on X-ray and on neutron powder diffraction data. Statistical distribution Si/Al is corroborated by lattice energy calculations (MAPLE). 29Si and 27Al solid-state NMR are in accordance with the crystallographic results. Ba2AlSi5N9 represents a new type of network structure made up of TN4 tetrahedra (T = Si, Al). Highly condensed layers of dreier rings with nitrogen connecting three neighboring tetrahedral centers occur which are further crosslinked by dreier rings and vierer rings. The dreier rings consist of corner-sharing tetrahedra, whereas some of the vierer rings exhibit two pairs of edge-sharing tetrahedra. In the resulting voids of the network there are eight different Ba2+ sites with coordination numbers between 6 and 10. Thermogravimetric investigations confirmed a thermal stability of Ba2AlSi5N9 up to about 1515°C (He atmosphere). Luminescence measurements on Ba2AlSi5N9:Eu2+ (2 mol % Eu2+) with an excitation wavelength of 450 nm revealed a broadband emission peaking at 584 nm (FWHM=100 nm) originating from dipole-allowed 4f6(7F)5d1 → 4f7(8S7/2) transitions

Identification of genetic variants associated with Huntington's disease progression: a genome-wide association study

Background Huntington's disease is caused by a CAG repeat expansion in the huntingtin gene, HTT. Age at onset has been used as a quantitative phenotype in genetic analysis looking for Huntington's disease modifiers, but is hard to define and not always available. Therefore, we aimed to generate a novel measure of disease progression and to identify genetic markers associated with this progression measure. Methods We generated a progression score on the basis of principal component analysis of prospectively acquired longitudinal changes in motor, cognitive, and imaging measures in the 218 indivduals in the TRACK-HD cohort of Huntington's disease gene mutation carriers (data collected 2008–11). We generated a parallel progression score using data from 1773 previously genotyped participants from the European Huntington's Disease Network REGISTRY study of Huntington's disease mutation carriers (data collected 2003–13). We did a genome-wide association analyses in terms of progression for 216 TRACK-HD participants and 1773 REGISTRY participants, then a meta-analysis of these results was undertaken. Findings Longitudinal motor, cognitive, and imaging scores were correlated with each other in TRACK-HD participants, justifying use of a single, cross-domain measure of disease progression in both studies. The TRACK-HD and REGISTRY progression measures were correlated with each other (r=0·674), and with age at onset (TRACK-HD, r=0·315; REGISTRY, r=0·234). The meta-analysis of progression in TRACK-HD and REGISTRY gave a genome-wide significant signal (p=1·12 × 10−10) on chromosome 5 spanning three genes: MSH3, DHFR, and MTRNR2L2. The genes in this locus were associated with progression in TRACK-HD (MSH3 p=2·94 × 10−8 DHFR p=8·37 × 10−7 MTRNR2L2 p=2·15 × 10−9) and to a lesser extent in REGISTRY (MSH3 p=9·36 × 10−4 DHFR p=8·45 × 10−4 MTRNR2L2 p=1·20 × 10−3). The lead single nucleotide polymorphism (SNP) in TRACK-HD (rs557874766) was genome-wide significant in the meta-analysis (p=1·58 × 10−8), and encodes an aminoacid change (Pro67Ala) in MSH3. In TRACK-HD, each copy of the minor allele at this SNP was associated with a 0·4 units per year (95% CI 0·16–0·66) reduction in the rate of change of the Unified Huntington's Disease Rating Scale (UHDRS) Total Motor Score, and a reduction of 0·12 units per year (95% CI 0·06–0·18) in the rate of change of UHDRS Total Functional Capacity score. These associations remained significant after adjusting for age of onset. Interpretation The multidomain progression measure in TRACK-HD was associated with a functional variant that was genome-wide significant in our meta-analysis. The association in only 216 participants implies that the progression measure is a sensitive reflection of disease burden, that the effect size at this locus is large, or both. Knockout of Msh3 reduces somatic expansion in Huntington's disease mouse models, suggesting this mechanism as an area for future therapeutic investigation

Unfallmechanismen und Verletzungsmuster bei Unfällen durch Tischkreissägen

Mehr als ein Drittel aller Arbeitsunfälle führen zu Handverletzungen, wovon wiederum ein Drittel auf sog. komplexe Verletzungen mit multistruktureller Zerstörung von Weichteilgewebe, Knochen, Gefäßen, Nerven und Sehnen entfallen. Im gewerblichen wie auch im privaten Bereich zählen Kreissägen zu den Arbeitsgeräten, die am häufigsten zu schweren Handverletzungen führen. Während Unfälle durch Kreissägen im gewerblichen Bereich durch Berufsgenossenschaften und Unfallkassen umfassend dokumentiert und untersucht werden, so gibt die Deutsche Gesetzliche Unfallversicherung (DGUV) für das Berichtsjahr 2010 insgesamt 4.822 meldepflichtige Unfälle durch Kreissägen an, liegen keine Daten über Häufigkeit, Ursachen und Hergänge von Kreissägeunfällen im privaten Bereich vor, deren Anzahl nach klinischer Erfahrung die der gewerblichen Unfälle deutlich übersteigen dürfte. Ziel dieser Arbeit war es, die im nicht-gewerblichen Bereich bisher fehlende Datengrundlage zu diesem häufigen Unfallereignis zu schaffen, die neben dem Unfallhergang auch den klinischen Verlauf, das funktionelle Ausheilungsergebnis sowie Angaben zu ggf. erfolgten Kompensationsleistungen gesetzlicher oder privater Unfallversicherungen beinhaltet. Basierend auf dieser Datengrundlage sollten wiederkehrende Unfallumstände identifiziert werden, die Ansatzpunkte möglicher Präventionsmaßnahmen sein könnten. In die Nachuntersuchung konnten 114 Patienten (107 männliche Patienten, Durchschnittsalter zum Unfallzeitpunkt 49 Jahre) eingeschlossen werden, die im Erhebungszeitraum nach einer Handverletzung durch Tischkreissägen in der Universitätsmedizin Greifswald stationär behandelt wurden. Die mittlere Zeitspanne zwischen Unfall und Nachuntersuchung lag bei 52 Monaten (7 - 136 Monate). Erfasst wurden umfangreiche retrospektive Angaben, u.a. zum persönlichen Hintergrund des Verletzten, zu den Unfallumständen, Art und Dauer der Behandlung sowie Dauer der Arbeitsunfähigkeit. Die Klassifikation der Verletzungsschwere erfolgte in drei Kategorien. Im Rahmen der klinischen Nachuntersuchung wurden statische Kraftprüfungen der Hand- und Fingerkraft durchgeführt. Der vom Verletzten subjektiv empfundene Gesundheitszustand der oberen Extremitäten wurde mit dem DASH-Fragebogen erhoben. Die subjektive Patientenzufriedenheit wurde mit einer numerischen Analogskala erfasst. Drei Viertel der untersuchten Unfälle ereigneten sich im privaten, ein Viertel im gewerblichen Bereich. Der stationären Behandlungsdauer von durchschnittlich einer Woche stand eine Arbeitsunfähigkeitsdauer von etwa 15 Wochen gegenüber. Dominante und nicht-dominante Hand waren zu etwa gleichen Anteilen betroffen. Überwiegend lagen Einfingerverletzungen vor (50 Fälle), die meist den radialen Pfeiler der Hand (Daumen 48 %, Zeigefinger 28 %) betrafen. Zweifingerverletzungen fanden sich in 25, Dreifingerverletzungen in 18, Vierfingerverletzungen in elf und Fünffingerverletzungen in sieben Fällen. Bei 15 untersuchten Patienten lag eine vollständige traumatische Amputation eines oder mehrerer Finger vor. Der Vergleich der Kraftentwicklung bei Handkraft, Pinzetten-, Schlüssel- und Dreipunktgriff für das gesamte Probandenkollektiv zeigte eine signifikante Kraftminderung der verletzten gegenüber der unverletzten Hand. Hinsichtlich der verschiedenen Verletzungsschweregrade bestanden signifikante Unterschiede lediglich bei den Grad-II- und -III-Verletzungen. In der Regel hatten die betroffenen Verletzten langjährige Erfahrung im Umgang mit Tischkreissägen. Die Mehrzahl der Unfälle ereignete sich bei für den Sägevorgang typischen Handpositionen. Dabei war der sog. „Kickback-Mechanismus“, bei dem es durch ein plötzliches Blockieren des Sägevorganges, z.B. durch einen Nagel im Schnittholz, zu einem Zurückschlagen des Schnittmaterials kommt, der häufigste Unfallmechanismus. In 13 % der untersuchten Unfälle wurde angegeben, dass vorhandene mechanische Sicherheitsausrüstungen an der Säge entfernt wurden. In einem hohen Anteil der untersuchten Probanden wurde keine bzw. falsche Sicherheitskleidung benutzt. So wurden in etwa einem Drittel der Fälle Arbeitshandschuhe getragen, wodurch sich das Verletzungsrisiko und die Verletzungsschwere an rotierenden Arbeitsgeräten deutlich erhöhen. Erstmals konnte in dieser Untersuchung herausgearbeitet werden, dass ein hohes Verletzungspotential von selbst- bzw. durch eine dritte Person konstruierten Tischkreissägen ausgeht. Von forensisch-traumatologischer Bedeutung sind Handverletzungen durch Tischkreissägen vor allem durch die Möglichkeit einer intentionellen Selbstschädigung zur Erlangung von Versicherungsleistungen. In keinem der untersuchten Fälle wurden Kompensationsleistungen unter diesem Aspekt verweigert.More than a third of all accidents result in hand injuries, which in turn a third called on complex injuries with multi structural destruction of soft tissue, bone, blood vessels, nerves and tendons omitted. In the commercial as well as in the private sector include circular saws to the work tools, the most common cause severe hand injuries. While accidents are well documented and analyzed by boaters in the commercial sector through professional associations and accident insurance, as are the German Social Accident Insurance (DGUV) for fiscal year 2010, a total of 4,822 reportable accidents by boaters on, there are no data on the frequency, causes and forth movements of table saw accidents the private sector before, their number on the clinical experience is likely to exceed the commercial accidents significantly. The aim of this study was to establish the existing gap in the non-commercial sector data basis for this frequent accident that also the clinical course, the functional outcome and information includes not only the circumstances of the accident to possibly made compensation payments statutory or private accident insurance. Based on this data basis recurring accident circumstances should be identified that could be starting points of possible preventive measures. In the follow-up 114 patients were included (107 male patients, mean age at the time of the accident 49) who were hospitalized during the survey period, after a hand injury by table saws in the University of Greifswald. The average time between the accident and follow-up was 52 months (7-136 months). In the survey were recorded extensive retrospective information, the personal background of the victim to the accident circumstances, the type and duration of treatment and duration of incapacity. The classification of injury severity was carried out in three categories. In the clinical follow-up static strength tests of the hand and finger strength were conducted. The subjectively perceived by the injured health of the upper extremities was charged with the DASH questionnaire. The subjective patient satisfaction has been detected with a numerical analog scale. Three-quarters of the accidents occurred in private, one-quarter in the commercial sector. The inpatient treatment lasting an average of one week was offset by a disability duration of approximately 15 weeks. Dominant and non-dominant hands were affected in roughly equal proportions. Mostly occurred injuries of only one finger (50 cases), the most radial pillars of hand (thumb 48%, forefinger 28%) concerned. Two finger injuries were found in 25, three-finger injury in 18, four-finger injury in eleven and five-finger injury in seven cases. In 15 patients studied a complete traumatic amputation of finger lay ahead. The comparison of the force development in hand strength, pincer, key and three-point grip for the entire test persons showed a significant loss of strength of the injured compared to the uninjured hand. With regard to the various categories of injury severities were significant differences only in the Grade II and III injuries. Usually the examined patients had many years of experience in dealing with table saws. The majority of the accidents occurred at typical sawing hand positions. It was the so-called. "Kickback mechanism", which is by a sudden blockage of the sawing operation, for example, comes by a nail in the timber to a flashback of the cut material, the most common mechanism of injury. In 13% of the accidents was stated that existing mechanical safety equipment were removed on the saw. In a high proportion of subjects studied or no false safety clothing was used. To work gloves were worn in about a third of cases, resulting in the risk of injury and the injury severity of rotating work tools increase significantly. For the first time could be worked out in this study that a high injury potential of self or constructed by a third person table saws emanates. From forensic traumatology importance are hand injuries caused by table saws mainly by the possibility of intentional self-harm to obtain insurance benefits. In none of the cases studied compensation benefits were denied under this aspect

Interaction of the Human Contact System with Pathogens—An Update

The name human contact system is related to its mode of action, as “contact” with artificial negatively charged surfaces triggers its activation. Today, it is generally believed that the contact system is an inflammatory response mechanism not only against artificial material but also against misfolded proteins and foreign organisms. Upon activation, the contact system is involved in at least two distinct (patho)physiologic processes:i. the trigger of the intrinsic coagulation via factor XI and ii. the cleavage of high molecular weight kininogen with release of bradykinin and antimicrobial peptides (AMPs). Bradykinin is involved in the regulation of inflammatory processes, vascular permeability, and blood pressure. Due to the release of AMPs, the contact system is regarded as a branch of the innate immune defense against microorganisms. There is an increasing list of pathogens that interact with contact factors, in addition to bacteria also fungi and viruses bind and activate the system. In spite of that, pathogens have developed their own mechanisms to activate the contact system, resulting in manipulation of this host immune response. In this up-to-date review, we summarize present research on the interaction of pathogens with the human contact system, focusing particularly on bacterial and viral mechanisms that trigger inflammation via contact system activation

Institutional strategies related to test-taking behavior in low stakes assessment

Low stakes assessment without grading the performance of students in educational systems has received increasing attention in recent years. It is used in formative assessments to guide the learning process as well as in large-scales assessments to monitor educational programs. Yet, such assessments suffer from high variation in students' test-taking effort. We aimed to identify institutional strategies related to serious test-taking behavior in low stakes assessment to provide medical schools with practical recommendations on how test-taking effort might be increased. First, we identified strategies that were already used by medical schools to increase the serious test-taking behavior on the low stakes Berlin Progress Test (BPT). Strategies which could be assigned to self-determination theory of Ryan and Deci were chosen for analysis. We conducted the study at nine medical schools in Germany and Austria with a total of 108,140 observations in an established low stakes assessment. A generalized linear-mixed effects model was used to assess the association between institutional strategies and the odds that students will take the BPT seriously. Overall, two institutional strategies were found to be positively related to more serious test-taking behavior: discussing low test performance with the mentor and consequences for not participating. Giving choice was negatively related to more serious test-taking behavior. At medical schools that presented the BPT as evaluation, this effect was larger in comparison to medical schools that presented the BPT as assessment