1,090 research outputs found

    Boundary Conditions on Internal Three-Body Wave Functions

    Get PDF
    For a three-body system, a quantum wave function Ψm\Psi^\ell_m with definite \ell and mm quantum numbers may be expressed in terms of an internal wave function χk\chi^\ell_k which is a function of three internal coordinates. This article provides necessary and sufficient constraints on χk\chi^\ell_k to ensure that the external wave function Ψm\Psi^\ell_m is analytic. These constraints effectively amount to boundary conditions on χk\chi^\ell_k and its derivatives at the boundary of the internal space. Such conditions find similarities in the (planar) two-body problem where the wave function (to lowest order) has the form rmr^{|m|} at the origin. We expect the boundary conditions to prove useful for constructing singularity free three-body basis sets for the case of nonvanishing angular momentum.Comment: 41 pages, submitted to Phys. Rev.

    An interleukin-1 polymorphism additionally intensified by atopy as prognostic factor for aseptic non-mechanical complications in metal knee and hip arthroplasty

    Get PDF
    Background: In contrast to infection or mechanical issues joint replacement failure following inflammatory adverse reactions is poorly understood. Objective: To assess the association of IL-1β polymorphisms and history of allergy with aseptic non-mechanical complications following arthroplasty. Methods: In 102 patients with aseptic non-mechanically caused symptomatic knee or hip arthroplasty (SA) and 93 patients with asymptomatic arthroplasty (AA) questionnaire-based history, patch test with at least standard series, lymphocyte transformation test (LTT) with nickel, cobalt and chromium and interleukin-1 polymorphism analysis were done. Three polymorphisms of the IL1B gene [IL-1b -3954 (rs1143634), IL-1b -511 (rs16944) and IL-1b -31 (rs1143627)] and one polymorphism of the IL1RN gene [IL1RN intron 2, variable number of tandem repeats, VNTR (rs2234663)] were assessed by PCR and gel electrophoresis. Results: We found no significant difference in smoking history and atopy but 25% versus 10% of self-reported metal allergy in SA versus AA; the patch test (respective, LTT) for metal sensitivity was more often positive in SA patients. The allele 498 bp of the IL1RN polymorphism occurred significantly more often in the SA group (37% versus 11%; p < 0.0001). Upon additional presence of atopy, the difference was even greater (60% vs 10%) (p < 0.000001). There was no association of IL-1 polymorphisms with metal allergy. Conclusion: The IL1RN VNTR allele 498 bp was strongly associated with SA. In patients with a history of atopy, presence of the IL1RN VNTR allele 498 bp led to a four-fold higher SA prevalence compared to patients without this allele

    Scarring Effects on Tunneling in Chaotic Double-Well Potentials

    Full text link
    The connection between scarring and tunneling in chaotic double-well potentials is studied in detail through the distribution of level splittings. The mean level splitting is found to have oscillations as a function of energy, as expected if scarring plays a role in determining the size of the splittings, and the spacing between peaks is observed to be periodic of period {2π2\pi\hbar} in action. Moreover, the size of the oscillations is directly correlated with the strength of scarring. These results are interpreted within the theoretical framework of Creagh and Whelan. The semiclassical limit and finite-{\hbar} effects are discussed, and connections are made with reaction rates and resonance widths in metastable wells.Comment: 22 pages, including 11 figure

    Novel multiple sclerosis susceptibility loci implicated in epigenetic regulation

    Get PDF
    We conducted a genome-wide association study (GWAS) on multiple sclerosis (MS) susceptibility in German cohorts with 4888 cases and 10,395 controls. In addition to associations within the major histocompatibility complex (MHC) region, 15 non-MHC loci reached genome-wide significance. Four of these loci are novel MS susceptibility loci. They map to the genes L3MBTL3, MAZ, ERG, and SHMT1. The lead variant at SHMT1 was replicated in an independent Sardinian cohort. Products of the genes L3MBTL3, MAZ, and ERG play important roles in immune cell regulation. SHMT1 encodes a serine hydroxymethyltransferase catalyzing the transfer of a carbon unit to the folate cycle. This reaction is required for regulation of methylation homeostasis, which is important for establishment and maintenance of epigenetic signatures. Our GWAS approach in a defined population with limited genetic substructure detected associations not found in larger, more heterogeneous cohorts, thus providing new clues regarding MS pathogenesis

    Mechanically Induced Amorphization of Diaqua-bis(Omeprazolate)-Magnesium Dihydrate

    No full text
    The influence of milling diaqua-bis(omeprazolate)-magnesium dihydrate (DABOMD), an active pharmaceutical ingredient (API), was investigated. DABOMD was processed in a planetary ball mill at different milling times, from 1 to 300 min. The milling process resulted in a prominent comminution (size reduction) and amorphization of the API. DABOMD amorphization was identified with various characterization techniques including thermogravimetric analysis, differential scanning calorimetry, powder X-ray diffraction, and attenuated total reflection-Fourier transform infrared spectroscopy. The solid–solid crystalline to amorphous phase transformation is driven by compression, shear stresses, and heat generated in the planetary ball mill. This leads to distortion and breakage of hydrogen bonds, release of water molecules from the crystalline lattice of DABOMD and the accumulation of defects, and eventually a collapse of the crystalline order. Model fitting of the kinetics of comminution and the amorphization of DABOMD revealed a series of events: a rapid comminution at the start of milling driven by crystal cleavage of DABOMD, followed by partial amorphization, which is driven by rapid water diffusion, and subsequently, a slow steady comminution and amorphization

    MicroRNA-138 is a potential regulator of memory performance in humans

    Get PDF
    Genetic factors underlie a substantial proportion of individual differences in cognitive functions in humans, including processes related to episodic and working memory. While genetic association studies have proposed several candidate "memory genes," these currently explain only a minor fraction of the phenotypic variance. Here, we performed genome-wide screening on 13 episodic and working memory phenotypes in 1318 participants of the Berlin Aging Study II aged 60 years or older. The analyses highlight a number of novel single nucleotide polymorphisms (SNPs) associated with memory performance, including one located in a putative regulatory region of microRNA (miRNA) hsa-mir-138-5p (rs9882688, P-value = 7.8 x 10(-9)). Expression quantitative trait locus analyses on next-generation RNA-sequencing data revealed that rs9882688 genotypes show a significant correlation with the expression levels of this miRNA in 309 human lymphoblastoid cell lines (P-value = 5 x 10(-4)). In silico modeling of other top-ranking GWAS signals identified an additional memory-associated SNP in the 3' untranslated region (3' UTR) of DCP1B, a gene encoding a core component of the mRNA decapping complex in humans, predicted to interfere with hsa-mir-138-5p binding. This prediction was confirmed in vitro by luciferase assays showing differential binding of hsa-mir-138-5p to 3' UTR reporter constructs in two human cell lines (HEK293: P-value = 0.0470; SH-SY5Y: P-value = 0.0866). Finally, expression profiling of hsa-mir-138-5p and DCP1B mRNA in human post-mortem brain tissue revealed that both molecules are expressed simultaneously in frontal cortex and hippocampus, suggesting that the proposed interaction between hsa-mir-138-5p and DCP1B may also take place in vivo. In summary, by combining unbiased genome-wide screening with extensive in silico modeling, in vitro functional assays, and gene expression profiling, our study identified miRNA-138 as a potential molecular regulator of human memory function

    Solution Structure of the Iron−Sulfur Cluster Cochaperone HscB and Its Binding Surface for the Iron−Sulfur Assembly Scaffold Protein IscU†‡

    Get PDF
    ABSTRACT: The interaction between IscU and HscB is critical for successful assembly of iron-sulfur clusters. NMR experiments were performed on HscB to investigate which of its residues might be part of the IscU binding surface. Residual dipolar couplings ( 1 DHN and 1 DCRHR) indicated that the crystal structure of HscB [Cupp-Vickery, J. R., and Vickery, L. E. (2000) Crystal structure of Hsc20, a J-type cochaperone from Escherichia coli, J. Mol. Biol. 304, 835-845] faithfully represents its solution state. NMR relaxation rates ( 15 N R1, R2) and 1 H- 15 N heteronuclear NOE values indicated that HscB is rigid along its entire backbone except for three short regions which exhibit flexibility on a fast time scale. Changes in the NMR spectrum of HscB upon addition of IscU mapped to the J-domain/C-domain interface, the interdomain linker, and the C-domain. Sequence conservation is low in the interface and in the linker, and NMR changes observed for these residues likely result from indirect effects of IscU binding. NMR changes observed in the conserved patch of residues in the C-domain (L92, M93, L96, E97, E100, E104, and F153) were suggestive of a direct interaction with IscU. To test this, we replaced several of these residues with alanine and assayed for the ability of HscB to interact with IscU and to stimulate HscA ATPase activity. HscB(L92A,M93A,F153A) and HscB(E97A,E100A,E104A) both showed decreased binding affinity for IscU; the (L92A,M93A,F153A) substitution also strongly perturbed the allosteric interactio

    Alzheimer's disease pathology explains association between dementia with Lewy bodies and APOE-ε4/TOMM40 long poly-T repeat allele variants.

    Get PDF
    Introduction: The role of TOMM40-APOE 19q13.3 region variants is well documented in Alzheimer's disease (AD) but remains contentious in dementia with Lewy bodies (DLB) and Parkinson's disease dementia (PDD). Methods: We dissected genetic profiles within the TOMM40-APOE region in 451 individuals from four European brain banks, including DLB and PDD cases with/without neuropathological evidence of AD-related pathology and healthy controls. Results: TOMM40-L/APOE-ε4 alleles were associated with DLB (OR TOMM40 -L = 3.61; P value = 3.23 × 10-9; OR APOE -ε4 = 3.75; P value = 4.90 × 10-10) and earlier age at onset of DLB (HR TOMM40 -L = 1.33, P value = .031; HR APOE -ε4 = 1.46, P value = .004), but not with PDD. The TOMM40-L/APOE-ε4 effect was most pronounced in DLB individuals with concomitant AD pathology (OR TOMM40 -L = 4.40, P value = 1.15 × 10-6; OR APOE -ε4 = 5.65, P value = 2.97 × 10-8) but was not significant in DLB without AD. Meta-analyses combining all APOE-ε4 data in DLB confirmed our findings (ORDLB = 2.93, P value = 3.78 × 10-99; ORDLB+AD = 5.36, P value = 1.56 × 10-47). Discussion: APOE-ε4/TOMM40-L alleles increase susceptibility and risk of earlier DLB onset, an effect explained by concomitant AD-related pathology. These findings have important implications in future drug discovery and development efforts in DLB
    corecore