924 research outputs found

    Anisotropic thermodynamic and transport properties of single crystalline CaKFe4_{4}As4_{4}

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    Single crystalline, single phase CaKFe4_{4}As4_{4} has been grown out of a high temperature, quaternary melt. Temperature dependent measurements of x-ray diffraction, anisotropic electrical resistivity, elastoresistivity, thermoelectric power, Hall effect, magnetization and specific heat, combined with field dependent measurements of electrical resistivity and field and pressure dependent measurements of magnetization indicate that CaKFe4_{4}As4_{4} is an ordered, stoichiometric, Fe-based superconductor with a superconducting critical temperature, TcT_c = 35.0 ±\pm 0.2 K. Other than superconductivity, there is no indication of any other phase transition for 1.8 K T\leq T \leq 300 K. All of these thermodynamic and transport data reveal striking similarities to that found for optimally- or slightly over-doped (Ba1x_{1-x}Kx_x)Fe2_2As2_2, suggesting that stoichiometric CaKFe4_4As4_4 is intrinsically close to what is referred to as "optimal-doped" on a generalized, Fe-based superconductor, phase diagram. The anisotropic superconducting upper critical field, Hc2(T)H_{c\text{2}}(T), of CaKFe4_{4}As4_{4} was determined up to 630 kOe. The anisotropy parameter γ(T)=Hc2/Hc2\gamma(T)=H_{c\text{2}}^{\perp}/H_{c\text{2}}^{\|}, for HH applied perpendicular and parallel to the c-axis, decreases from 2.5\simeq 2.5 at TcT_c to 1.5\simeq 1.5 at 25 K which can be explained by interplay of paramagnetic pairbreaking and orbital effects. The slopes of dHc2/dT44dH_{c\text{2}}^{\|}/dT\simeq-44 kOe/K and dHc2/dT109dH_{c\text{2}}^{\perp}/dT \simeq-109 kOe/K at TcT_c yield an electron mass anisotropy of m/m1/6m_{\perp}/m_{\|}\simeq 1/6 and short Ginzburg-Landau coherence lengths ξ(0)5.8A˚\xi_{\|}(0)\simeq 5.8 \text{\AA} and ξ(0)14.3A˚\xi_{\perp}(0)\simeq 14.3 \text{\AA}. The value of Hc2(0)H_{c\text{2}}^{\perp}(0) can be extrapolated to 920\simeq 920 kOe, well above the BCS paramagnetic limit.Comment: 13 pages, 15 figures, part of arXiv:1606.02241 is include

    Screening and assessment tools for gaming disorder: A comprehensive systematic review

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    The inclusion of gaming disorder (GD) as an official diagnosis in the ICD-11 was a significant milestone for the field. However, the optimal measurement approaches for GD are currently unclear. This comprehensive systematic review aimed to identify and evaluate all available English-language GD tools and their corresponding evidence. A search of PsychINFO, PsychArticles, ScienceDirect, Scopus, Web of Science, and Google Scholar identified 32 tools employed in 320 studies (N = 462,249 participants). The evaluation framework examined tools in relation to: (1) conceptual and practical considerations; (2) alignment with DSM-5 and ICD-11 criteria; (3) type and quantity of studies and samples; and (4) psychometric properties. The evaluation showed that GD instrumentation has proliferated, with 2.5 tools, on average, published annually since 2013. Coverage of DSM-5 and ICD-11 criteria was inconsistent, especially for the criterion of continued use despite harm. Tools converge on the importance of screening for impaired control over gaming and functional impairment. Overall, no single tool was found to be clearly superior, but the AICA-Sgaming, GAS-7, IGDT-10, IGDS9-SF, and Lemmens IGD-9 scales had greater evidential support for their psychometric properties. The GD field would benefit from a standard international tool to identify gaming-related harms across the spectrum of maladaptive gaming behaviors.Peer reviewedFinal Accepted Versio

    Androgen action on renal calcium and phosphate handling: Effects of bisphosphonate treatment and low calcium diet

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    Renal calcium and phosphate handling is an important contributor to mineral homeostasis and bone health and the androgen receptor (AR) is highly expressed in the kidney. We investigated the short term effects of androgen deprivation on renal calcium and phosphate reabsorption, independent of their effects on bone. Two weeks following orchidectomy (ORX) of adult mice, bone loss occurred along with hypercalciuria, which was similarly prevented by testosterone and dihydrotestosterone supplementation. Treatment with bisphosphonates prior to ORX also inhibited hypercalciuria, indicating that the calcium flux originated from the bone. Renal calcium and phosphate transporter expression was increased post-ORX, independent of bisphosphonates. Furthermore, androgen deprivation appeared to stimulate local synthesis of 1,25(OH)2D3. When bisphosphonate-treated mice were fed a low calcium diet, bone resorption was no longer blocked and secondary hyperparathyroidism developed, which was more pronounced in ORX mice than sham-operated mice. In conclusion, this study shows that androgen deprivation increased renal calcium and phosphate transporter expression, independent of bone, and underlines the importance of adequate intestinal calcium supply in circumstances of androgen deprivation and bisphosphonate treatment.status: publishe

    Character building in childrens’ online information behaviours: applying a virtue epistemology perspective to information literacy.

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    This paper advances our understanding of the theoretical and practical challenges of developing intellectual character in children’s online information behaviours. We argue that widely reported issues such as misinformation and disinformation extend IL education beyond considerations of ability to considerations of disposition, and highlight this as an understudied topic within IL education. We introduce the classical concept of intellectual character and discuss virtues traits in the IL context. Applying Baehr’s nine intellectual virtues to two commonly cited IL models, we evidence limited presence of virtues in IL models, and propose an important agenda for future research

    Identification of PSEN1 and APP Gene Mutations in Korean Patients with Early-Onset Alzheimer's Disease

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    Although mutations in three genes, amyloid precursor protein (APP), presenilin 1 (PSEN1), and presenilin 2 (PSEN2), have been identified as genetic causes of early-onset Alzheimer's disease (EOAD), there has been a single report on a PSEN1 mutation in Koreans. In the present study, we performed a genetic analysis of six Korean patients with EOAD. Direct sequencing analysis of the APP, PSEN1 and PSEN2 genes revealed two different mutations of the PSEN1 gene (G206S and M233T) and one mutation of the APP gene (V715M) in three patients with age-at-onset of 34, 35, and 42 yr, respectively. In addition, two patients with age-at-onset of 55 and 62 yr, respectively, were homozygous for APOE ε4 allele. One woman had no genetic alterations. These findings suggest that PSEN1 and APP gene mutations may not be uncommon in Korean patients with EOAD and that genetic analysis should be provided to EOAD patients not only for the identification of their genetic causes but also for the appropriate genetic counseling

    Turbulent natural convection over a slender circular cylinder

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    The transverse-curvature effect on the heat transfer in the turbulent natural convection flow from the outer surface of a slender vertical circular cylinder is studied by an improved integral method for various values of Prandtl numbers and for various values of a transverse curvature parameter. Der Einfluß der Querkrümmung auf die Wärmeübertragung von der Außenoberfläche eines dünnen senkrechten Kreiszylinders in die turbulente, natürliche Konvektionsströmung wird mittels eines verbesserten Integral-Verfahrens für verschiedene Werte der Prandtl-Zahlen und der Querkrümmungsparameter untersucht.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46651/1/231_2005_Article_BF01637697.pd

    Rare germline variants in DNA repair genes and the angiogenesis pathway predispose prostate cancer patients to develop metastatic disease

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    Background Prostate cancer (PrCa) demonstrates a heterogeneous clinical presentation ranging from largely indolent to lethal. We sought to identify a signature of rare inherited variants that distinguishes between these two extreme phenotypes. Methods We sequenced germline whole exomes from 139 aggressive (metastatic, age of diagnosis < 60) and 141 non-aggressive (low clinical grade, age of diagnosis ≥60) PrCa cases. We conducted rare variant association analyses at gene and gene set levels using SKAT and Bayesian risk index techniques. GO term enrichment analysis was performed for genes with the highest differential burden of rare disruptive variants. Results Protein truncating variants (PTVs) in specific DNA repair genes were significantly overrepresented among patients with the aggressive phenotype, with BRCA2, ATM and NBN the most frequently mutated genes. Differential burden of rare variants was identified between metastatic and non-aggressive cases for several genes implicated in angiogenesis, conferring both deleterious and protective effects. Conclusions Inherited PTVs in several DNA repair genes distinguish aggressive from non-aggressive PrCa cases. Furthermore, inherited variants in genes with roles in angiogenesis may be potential predictors for risk of metastases. If validated in a larger dataset, these findings have potential for future clinical application

    Heated indoor swimming pools, infants, and the pathogenesis of adolescent idiopathic scoliosis: a neurogenic hypothesis

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    <p>Abstract</p> <p>Background</p> <p>In a case-control study a statistically significant association was recorded between the introduction of infants to heated indoor swimming pools and the development of adolescent idiopathic scoliosis (AIS). In this paper, a neurogenic hypothesis is formulated to explain how toxins produced by chlorine in such pools may act deleteriously on the infant's immature central nervous system, comprising brain and spinal cord, to produce the deformity of AIS.</p> <p>Presentation of the hypothesis</p> <p>Through vulnerability of the developing central nervous system to circulating toxins, and because of delayed epigenetic effects, the trunk deformity of AIS does not become evident until adolescence. In mature healthy swimmers using such pools, the circulating neurotoxins detected are chloroform, bromodichloromethane, dibromochloromethane, and bromoform. Cyanogen chloride and dichloroacetonitrile have also been detected.</p> <p>Testing the hypothesis</p> <p>In infants, the putative portals of entry to the blood could be dermal, oral, or respiratory; and entry of such circulating small molecules to the brain are via the blood-brain barrier, blood-cerebrospinal fluid barrier, and circumventricular organs. Barrier mechanisms of the developing brain differ from those of adult brain and have been linked to brain development. During the first 6 months of life cerebrospinal fluid contains higher concentrations of specific proteins relative to plasma, attributed to mechanisms continued from fetal brain development rather than immaturity.</p> <p>Implications of the hypothesis</p> <p>The hypothesis can be tested. If confirmed, there is potential to prevent some children from developing AIS.</p
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