High-pressure structural phase transitions in semiconducting niobium dioxide

Niobium dioxide was studied up to 47 GPa by angle-dispersive, x-ray powder diffraction. Semiconducting α − NbO 2 (space group I 4 1 / a , Z = 32 ) was found to transform to β − NbO 2 (space group I 4 1 , Z = 16 ) above 5 GPa. Both phases have distorted rutile-type structures and the transition involves a change in the long-range ordering of the metal-metal bonds. A further transition was observed above 8 GPa to a baddeleyite-related structure with a = 9.975 ( 1 ) , b = 9.963 ( 1 ) , c = 9.933 ( 1 ) Å , β = 104.023 ( 4 ) ° , and Z = 32 at 12.8 GPa. The doubling of the unit cell along a, b, and c and the larger monoclinic angle with respect to a baddeleyite-type cell are due to the presence of metal-metal bonds. The d 1 cation dioxide, NbO 2 , is thus shown to behave in a similar way to d 0 cation dioxides, which follow a phase transition sequence involving the baddeleyite-type structure

Mindfulness and Other Psycho-Social Resources Protective Against Mental Illness and Suicidality Among Gay Men.

Background: There is considerable evidence of health disparities among gay men characterized by higher levels of stress and distress. Psycho-social resources have been linked to numerous positive health outcomes and shown to act as buffers in the stress-distress pathway. Methods: With data from the 3rd Geneva Gay Men's Health Survey carried out in 2011 using time-space sampling (n = 428), a relatively elaborate profile of 14 psycho-social resources-including mindfulness-is presented. Using their original scores, latent class analysis created an index variable dividing the respondents into meaningful groups. Psycho-social resources-the index variable as well as each resource individually-were then compared to two recent outcomes-i.e., serious mental illness in the past 4 weeks and short-term disability in the past 2 weeks-using a series of logistic regression models, controlling for all other psycho-social resources and socio-demographic confounders. To assess their potential role as buffers, a similar series of logistic regression models were erected using victimization and three outcomes-i.e., major depression, suicidal ideation, and suicide attempt-in the past 12 months. Results: According to the latent class analyses, (1) 5.1% of this sample had a low level of psycho-social resources (i.e., one standard deviation (SD) below the group means), (2) 25.2% a medium-low level, (3) 47.4% a medium level (i.e., at the group means), and (4) 22.2% a high level of psycho-social resources (i.e., one SD above the group means). Psycho-social resources appeared to strongly protect against recent mental morbidity and buffer against the impact of victimization on major depression and suicidality in the past 12 months, reducing the adjusted odds ratios below statistical significance. The explained variance and the individual psycho-social resources which remained independent in the models differed for each outcome. Conclusions: There may be disparities in several psycho-social resources among gay men, and as strong compensatory and protective factors, they may explain in part the well-established disparities in stress and distress in this population. While multiple psycho-social resources should be promoted in this population, gay men under 25 years should receive particular attention as all three disparities are most pronounced in this age group

Die Kontroverse um die Hydratation am Lebensende : ein Update

Einleitung: Die Hydratation am Lebensende kann sowohl positive als auch negative Wirkungen auf die Betroffenen haben. Deshalb wird sie in der palliativen Praxis kontrovers diskutiert. Unter Hydratation wird die enterale oder parenterale Zufuhr von Flüssigkeit verstanden. Positive Wirkungen davon können ein vermindertes Durstgefühl und Xerostomie sowie ein geringeres Risiko für ein Delir sein. Als negative Wirkung kann eine Volumenüberlastung, die zu Dyspnoe und Ödemen führt, oder ein erhöhtes Urinvolumen mit Inkontinenzproblematiken auftreten. Ziel / Fragestellung: Was sind Indikationen einer Hydratation bzw. Dehydratation in der terminalen Phase? Methode: Es wurde eine Literaturrecherche auf den Datenbanken PubMed und CINAHL Complete durchgeführt. Die Literaturrecherche wurde per Handsuche auf fachrelevanten Websites ergänzt, um aktuelle Best Practice-Empfehlungen mit einzubeziehen. Ergebnisse: Die Hydratation hängt von verschiedenen Faktoren ab, jede Patient:innen-Situation muss dabei individuell betrachtet werden. Dabei müssen Vor-/Nachteile der Hydratation gegeneinander abgewogen sowie die Indikation für Hydratation bzw. Dehydratation gestellt werden. Es ist von grosser Relevanz, die Hydratation am Lebensende wo möglich mit der betroffenen Person und der Familie zu besprechen. Diskussion / Empfehlungen für die Praxis: Je nach vorhandenen Symptomen ist der Nutzen der Hydratation am Lebensende noch ungeklärt. Durst oder Xerostomie kann durch eine Hydratation nur bedingt gelindert werden, relevanter ist dabei die Mundpflege. Bei Nausea und Emesis kann weniger Flüssigkeit im Magen und im Körper zu einer Symptomlinderung führen. Eine Dehydratation kann diese Symptome jedoch auch hervorrufen. Zudem kann es durch eine Dehydratation zu einer Medikamentenakkumulation kommen, was zu verstärkten unerwünschten Wirkungen führen oder die pharmakologische Wirksamkeit erhöhen kann. Es ist bekannt, dass am Lebensende der Flüssigkeitsbedarf abnimmt und dies als natürlicher Prozess gesehen werden kann. Schlussfolgerung: Von einer standardisierten Hydratation in der terminalen Phase kann abgesehen werden. Jede Situation sollte individuell durch Fachpersonen beurteilt werden, wobei die Bedürfnisse der betroffenen Person und der Familie einbezogen werden sollen. Die Entscheidung bedarf einer Re-Evaluation, sobald sich die Situation verändert

Pressure-induced alpha-to-omega transition in titanium metal: A systematic study of the effects of uniaxial stress

We investigated the effects of uniaxial stress on the pressure-induced alpha-to-omega transition in pure titanium (Ti) by means of angle dispersive x-ray diffraction in a diamond-anvil cell. Experiments under four different pressure environments reveal that: (1) the onset of the transition depends on the pressure medium used, going from 4.9 GPa (no pressure medium) to 10.5 GPa (argon pressure medium); (2) the a and w phases coexist over a rather large pressure range, which depends on the pressure medium employed; (3) the hysteresis and quenchability of the w phase is affected by differences in the sample pressure environment; and (4) a short term laser-heating of Ti lowers the alpha-to-omega transition pressure. Possible transition mechanisms are discussed in the light of the present results, which clearly demonstrated the influence of uniaxial stress in the alpha-to-omega transition.Comment: 16 pages, 6 figures, 1 tabl

The Swiss Kidney Stone Cohort (SKSC), a longitudinal, multi-centric, observational cohort to study course and causes of kidney stone disease in Switzerland.

Kidney stone disease has a high prevalence worldwide of approximately 10 % of the population and is characterized by a high recurrence rate Kidney stone disease results from a combination of genetic, environmental, and life-style risk factors, and the dissection of these factors is complex. The Swiss Kidney Stone Cohort (SKSC) is an investigator-initiated prospective, multi-centric longitudinal, observational study in patients with kidney stones followed with regular visits over a period of 3 years after inclusion. Ongoing follow-ups by biannual telephone interviews will provide long-term outcome data up to 10 years. SKSC comprises 782 adult patients (age > 18 yrs) with either recurrent stones or a single stone event with at least one risk factor for recurrence. In addition, a control cohort of 207 individuals without kidney stone history and absence of kidney stones on a low-dose CT-scan at enrolment has also been recruited. SKSC includes extensive collections of clinical data, biochemical data in blood and 24 hr urine samples, and genetic data. Biosamples are stored at a dedicated biobank. Information on diet and dietary habits were collected through food frequency questionnaires and standardized recall interviews by trained dieticians with the Globodiet software. SKSC provides an unique opportunity and resource to further study cause and course of kidney disease in a large population with data and samples collected of a homogenous collective of patients throughout the whole Swiss population

Melting of tantalum at high pressure determined by angle dispersive x-ray diffraction in a double-sided laser-heated diamond-anvil cell

The high pressure and high temperature phase diagram of Ta has been studied in a laser-heated diamond-anvil cell (DAC) using x-ray diffraction measurements up to 52 GPa and 3800 K. The melting was observed at nine different pressures, being the melting temperature in good agreement with previous laser-heated DAC experiments, but in contradiction with several theoretical calculations and previous piston-cylinder apparatus experiments. A small slope for the melting curve of Ta is estimated (dTm/dP = 24 K/GPa at 1 bar) and a possible explanation for this behaviour is given. Finally, a P-V-T equation of states is obtained, being the temperature dependence of the thermal expansion coefficient and the bulk modulus estimated.Comment: 31 pages, 8 figures, to appear in J.Phys.:Cond.Matte

Sozialstaatliche Kürzungspolitik in Deutschland: Nur eine Mär? Eine quantitative Gesetzgebungsanalyse 1974–2014

Quantitative analyses on welfare state dynamics have to cope with the “dependent variable problem”, as studies on social spending reach different conclusions than analyses of replacement rate data. This article suggests a way around this problem by presenting results from a fine-grained analysis of welfare state legislation in Germany between 1974 and 2014. We show that the German welfare state has seen both cuts and expansions occur in all decades. Moreover, we show by means of a regression analysis that partisan politics play a role. Supporting the “Nixon-in-China”-thesis, social democratic governments are associated with a higher probability of cutbacks – especially in times of budgetary pressure – whereas expansions are more likely under Christian democratic governments