959 research outputs found
Plasma arginine vasopressin concentrations in epileptics under monotherapy
Plasma arginine vasopressin concentrations were determined by radio-immunoassay in 112 adult epileptics who were taking carbamazepine, phenytoin, primidone, or sodium valproate in long-term monotherapy, and in 19 controls. No significant difference was found between the groups, but some epileptics taking carbamazepine and primidone showed low values. Serum
concentrations of carbamazepine did not correlate with the concentrations of plasma arginine vasopressin.
In conclusion, there was no evidence of a stimulating
effect of chronic carbamazepine medication or a special inhibiting effect of phenytoin on the release of vasopressin arginine from the posterior pituitary
Association of a Bovine Prion Gene Haplotype with Atypical BSE
Background: Atypical bovine spongiform encephalopathies (BSEs) are recently recognized prion diseases of cattle. Atypical BSEs are rare; approximately 30 cases have been identified worldwide. We tested prion gene (PRNP) haplotypes for an association with atypical BSE.
Methodology/Principle Findings: Haplotype tagging polymorphisms that characterize PRNP haplotypes from the promoter region through the three prime untranslated region of exon 3 (25.2 kb) were used to determine PRNP haplotypes of six available atypical BSE cases from Canada, France and the United States. One or two copies of a distinct PRNP haplotype were identified in five of the six cases (p = 1.36Ă10-4, two-tailed Fisherâs exact test; CI95% 0.263â0.901, difference between proportions). The haplotype spans a portion of PRNP that includes part of intron 2, the entire coding region of exon 3 and part of the three prime untranslated region of exon 3 (13 kb).
Conclusions/Significance: This result suggests that a genetic determinant in or near PRNP may influence susceptibility of cattle to atypical BSE
Unmet need for the treatment of depression in Atlantic Canada
Objective: Most people with depression do not receive treatment, even though effective interventions are available. Population-based data can assist health service planners to improve access to mental health services. This study aimed to examine the determinants of untreated depression in Canada's Atlantic provinces
The mean free path for electron conduction in metallic fullerenes
We calculate the electrical resistivity due to electron-phonon scattering for
a model of A3C60 (A= K, Rb), using an essentially exact quantum Monte-Carlo
calculation. In agreement with experiment, we obtain exceptionally large
metallic resistivities at large temperatures T. This illustrates that the
apparent mean free path can be much shorter than the separation of the
molecules. An interpretation of this result is given. The calculation also
explains the linear behavior in T at small T.Comment: 4 pages, RevTeX, 3 eps figure, additional material available at
http://www.mpi-stuttgart.mpg.de/docs/ANDERSEN/fullerene
Searching for the rules of electrochemical nitrogen fixation
Li-mediated ammonia synthesis is, thus far, the only electrochemical method for heterogeneous decentralized ammonia production. The unique selectivity of the solid electrode provides an alternative to one of the largest heterogeneous thermal catalytic processes. However, it is burdened with intrinsic energy losses, operating at a Li plating potential. In this work, we survey the periodic table to understand the fundamental features that make Li stand out. Through density functional theory calculations and experimentation on chemistries analogous to lithium (e.g., Na, Mg, Ca), we find that lithium is unique in several ways. It combines a stable nitride that readily decomposes to ammonia with an ideal solid electrolyte interphase, balancing reagents at the reactive interface. We propose descriptors based on simulated formation and binding energies of key intermediates and further on hard and soft acids and bases (HSAB principle) to generalize such features. The survey will help the community toward electrochemical systems beyond Li for nitrogen fixation
The role of ion solvation in lithium mediated nitrogen reduction
Since its verification in 2019, there have been numerous high-profile papers reporting improved efficiency of lithium-mediated electrochemical nitrogen reduction to make ammonia. However, the literature lacks any coherent investigation systematically linking bulk electrolyte properties to electrochemical performance and Solid Electrolyte Interphase (SEI) properties. In this study, we discover that the salt concentration has a remarkable effect on electrolyte stability: at concentrations of 0.6 M LiClO4 and above the electrode potential is stable for at least 12 hours at an applied current density of â2 mA cmâ2 at ambient temperature and pressure. Conversely, at the lower concentrations explored in prior studies, the potential required to maintain a given N2 reduction current increased by 8 V within a period of 1 hour under the same conditions. The behaviour is linked more coordination of the salt anion and cation with increasing salt concentration in the electrolyte observed via Raman spectroscopy. Time of flight secondary ion mass spectrometry and X-ray photoelectron spectroscopy reveal a more inorganic, and therefore more stable, SEI layer is formed with increasing salt concentration. A drop in faradaic efficiency for nitrogen reduction is seen at concentrations higher than 0.6 M LiClO4, which is attributed to a combination of a decrease in nitrogen solubility and diffusivity as well as increased SEI conductivity as measured by electrochemical impedance spectroscopy
Nonaqueous Li-mediated nitrogen reduction: taking control of potentials
The performance of the Li-mediated ammonia synthesis has progressed dramatically since its recent reintroduction. However, fundamental understanding of this reaction is slower paced, due to the many uncontrolled variables influencing it. To address this, we developed a true nonaqueous LiFePO4 reference electrode, providing both a redox anchor from which to measure potentials against and estimates of sources of energy efficiency loss. We demonstrate its stable electrochemical potential in operation using different N2- and H2-saturated electrolytes. Using this reference, we uncover the relation between partial current density and potentials. While the counter electrode potential increases linearly with current, the working electrode remains stable at lithium plating, suggesting it to be the only electrochemical step involved in this process. We also use the LiFePO4/Li+ equilibrium as a tool to probe Li-ion activity changes in situ. We hope to drive the field toward more defined systems to allow a holistic understanding of this reaction
A promoter SNP rs4073T>A in the common allele of the interleukin 8 gene is associated with the development of idiopathic pulmonary fibrosis via the IL-8 protein enhancing mode
<p>Abstract</p> <p>Background</p> <p>Interleukin-8 (IL-8) is a potent chemo-attractant cytokine responsible for neutrophil infiltration in lungs with idiopathic pulmonary fibrosis (IPF). The IL-8 protein and mRNA expression are increased in the lung with IPF. We evaluated the effect of single nucleotide polymorphisms (SNPs) of the IL-8 gene on the risk of IPF.</p> <p>Methods</p> <p>One promoter (rs4073T>A) and two intronic SNPs (rs2227307T>G and rs2227306C>T) of the IL-8 genes were genotyped in 237 subjects with IPF and 456 normal controls. Logistic regression analysis was applied to evaluate the association of these SNPs with IPF. IL-8 in BAL fluids was measured using a quantitative sandwich enzyme immunoassay, and promoter activity was assessed using the luciferase reporter assay.</p> <p>Results</p> <p>The minor allele frequencies of rs4073T>A and rs2227307T>G were significantly lower in the 162 subjects with surgical biopsy-proven IPF and 75 subjects with clinical IPF compared with normal controls in the recessive model (OR = 0.46 and 0.48, <it>p </it>= 0.006 and 0.007, respectively). The IL-8 protein concentration in BAL fluids significantly increased in 24 subjects with IPF compared with 14 controls (<it>p </it>= 0.009). Nine IPF subjects homozygous for the rs4073 T>A common allele exhibited higher levels of the IL-8 protein compared with six subjects homozygous for the minor allele (<it>p </it>= 0.024). The luciferase activity of the rs4073T>A common allele was significantly higher than that of the rs4073T>A minor allele (<it>p </it>= 0.002).</p> <p>Conclusion</p> <p>The common allele of a promoter SNP, rs4073T>A, may increase susceptibility to the development of IPF via up-regulation of IL-8.</p
The first legal mortgagor: a consumer without adequate protection?
This article contends that the UK governmentâs attempt to create a well-functioning consumer credit market will be undermined if it fails to reform the private law framework relating to the first legal mortgage. Such agreements are governed by two distinct regulatory regimes that are founded upon very different conceptions of the mortgagor. The first, the regulation of financial services overseen by the Financial Conduct Authority, derives from public law and is founded upon a conception of the mortgagor as âconsumerâ. The other is land law, private law regulation implemented by the judiciary and underpinned by a conception of the mortgagor as âlandownerâ. Evidence suggests that the operation of these two regimes prevents mortgagors from receiving fair and consistent treatment. The current reform of financial services regulation therefore will change only one part of this governance regime and will leave mortgagors heavily reliant upon a regulator that still has to prove itself. What this article argues is that reform of the rules of private law must also be undertaken with the aim of initiating a paradigm shift in the conception of the mortgagor from âlandownerâ to âconsumerâ. Cultural shifts of this kind take time but the hope is that this conceptual transformation will occur in time to deter the predicted rise in mortgage possessions
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