634 research outputs found

    Operator Method for Nonperturbative Calculation of the Thermodynamic Values in Quantum Statistics. Diatomic Molecular Gas

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    Operator method and cumulant expansion are used for nonperturbative calculation of the partition function and the free energy in quantum statistics. It is shown for Boltzmann diatomic molecular gas with some model intermolecular potentials that the zeroth order approximation of the proposed method interpolates the thermodynamic values with rather good accuracy in the entire range of both the Hamiltonian parameters and temperature. The systematic procedure for calculation of the corrections to the zeroth order approximation is also considered.Comment: 22 pages, 7 Postscript figures, accepted for publication in Journal of Physics

    Relationship of Genotype, Phenotype, and Treatment in Dopa-Responsive Dystonia: MDSGene Review

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    Background Pathogenic variants in 5 genes (GCH1, TH, PTS, SPR, and QDPR), involved in dopamine/tetrahydrobiopterin biosynthesis or recycling, have been linked to Dopa-responsive dystonia (DRD). Diagnosis and treatment are often delayed due to high between- and within-group variability. Objectives Comprehensively analyzed individual genotype, phenotype, treatment response, and biochemistry information. Methods 734 DRD patients and 151 asymptomatic GCH1 mutation carriers were included using an MDSGene systematic literature review and an automated classification approach to distinguish between different forms of monogenic DRDs. Results Whereas dystonia, L-Dopa responsiveness, early age at onset, and diurnal fluctuations were identified as red flags, parkinsonism without dystonia was rarely reported (11%) and combined with dystonia in only 18% of patients. While sex was equally distributed in autosomal recessive DRD, there was female predominance in autosomal dominant DYT/PARK-GCH1 patients accompanied by a lower median age at onset and more dystonia in females compared to males. Accordingly, the majority of asymptomatic heterozygous GCH1 mutation carriers (>8 years of age) were males. Multiple other subgroup-specific characteristics were identified, showing high accuracy in the automated classification approach: Seizures and microcephaly were mostly seen in DYT/PARK-PTS, autonomic symptoms appeared commonly in DYT/PARK-TH and DYT/PARK-PTS, and sleep disorders and oculogyric crises in DYT/PARK-SPR. Biochemically, homovanillic acid and 5-hydroxyindoleacetic acid in CSF were reduced in most DRDs, but neopterin and biopterin were increased only in DYT/PARK-PTS and DYT/PARK-SPR. Hyperphenylalaninemia was seen in DYT/PARK-PTS, DYT/PARK-QDPR, and rarely reported in autosomal recessive DYT/PARK-GCH1. Conclusions Our indicators will help to specify diagnosis and accelerate start of treatment. © 2021 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Societ

    Interrater reliability of motor severity scales for hemifacial spasm

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    To compare the inter-rater reliability (IRR) of five clinical rating scales for video-based assessment of hemifacial spasm (HFS) motor severity. We evaluated the video recordings of 45 HFS participants recruited through the Dystonia Coalition. In Round 1, six clinicians with expertise in HFS assessed the participants\u27 motor severity with five scales used to measure motor severity of HFS: the Jankovic rating scale (JRS), Hemifacial Spasm Grading Scale (HSGS), Samsung Medical Center (SMC) grading system for severity of HFS spasms (Lee\u27s scale), clinical grading of spasm intensity (Chen\u27s scale), and a modified version of the Abnormal Involuntary Movement Scale (Tunc\u27s scale). In Round 2, clinicians rated the same cohort with simplified scale wording after consensus training. For each round, we evaluated the IRR using the intraclass correlation coefficient [ICC (2,1) single-rater, absolute-agreement, 2-way random model]. The scales exhibited IRR that ranged from poor to moderate ; the mean ICCs were 0.41, 0.43, 0.47, 0.43, and 0.65 for the JRS, HSGS, Lee\u27s, Chen\u27s, and Tunc\u27s scales, respectively, for Round 1. In Round 2, the corresponding IRRs increased to 0.63, 0.60, 0.59, 0.53, and 0.71. In both rounds, Tunc\u27s scale exhibited the highest IRR. For clinical assessments of HFS motor severity based on video observations, we recommend using Tunc\u27s scale because of its comparative reliability and because clinicians interpret the scale easily without modifications or the need for consensus training

    Maternal PlGF and umbilical Dopplers predict pregnancy outcomes at diagnosis of early-onset fetal growth restriction

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    BACKGROUNDSevere, early-onset fetal growth restriction (FGR) causes significant fetal and neonatal mortality and morbidity. Predicting the outcome of affected pregnancies at the time of diagnosis is difficult, thus preventing accurate patient counseling. We investigated the use of maternal serum protein and ultrasound measurements at diagnosis to predict fetal or neonatal death and 3 secondary outcomes: fetal death or delivery at or before 28+0 weeks, development of abnormal umbilical artery (UmA) Doppler velocimetry, and slow fetal growth.METHODSWomen with singleton pregnancies (n = 142, estimated fetal weights [EFWs] below the third centile, less than 600 g, 20+0 to 26+6 weeks of gestation, no known chromosomal, genetic, or major structural abnormalities) were recruited from 4 European centers. Maternal serum from the discovery set (n = 63) was analyzed for 7 proteins linked to angiogenesis, 90 additional proteins associated with cardiovascular disease, and 5 proteins identified through pooled liquid chromatography and tandem mass spectrometry. Patient and clinician stakeholder priorities were used to select models tested in the validation set (n = 60), with final models calculated from combined data.RESULTSThe most discriminative model for fetal or neonatal death included the EFW z score (Hadlock 3 formula/Marsal chart), gestational age, and UmA Doppler category (AUC, 0.91; 95% CI, 0.86-0.97) but was less well calibrated than the model containing only the EFW z score (Hadlock 3/Marsal). The most discriminative model for fetal death or delivery at or before 28+0 weeks included maternal serum placental growth factor (PlGF) concentration and UmA Doppler category (AUC, 0.89; 95% CI, 0.83-0.94).CONCLUSIONUltrasound measurements and maternal serum PlGF concentration at diagnosis of severe, early-onset FGR predicted pregnancy outcomes of importance to patients and clinicians.TRIAL REGISTRATIONClinicalTrials.gov NCT02097667.FUNDINGThe European Union, Rosetrees Trust, Mitchell Charitable Trust

    Review of two-photon exchange in electron scattering

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    We review the role of two-photon exchange (TPE) in electron-hadron scattering, focusing in particular on hadronic frameworks suitable for describing the low and moderate Q^2 region relevant to most experimental studies. We discuss the effects of TPE on the extraction of nucleon form factors and their role in the resolution of the proton electric to magnetic form factor ratio puzzle. The implications of TPE on various other observables, including neutron form factors, electroproduction of resonances and pions, and nuclear form factors, are summarized. Measurements seeking to directly identify TPE effects, such as through the angular dependence of polarization measurements, nonlinear epsilon contributions to the cross sections, and via e+ p to e- p cross section ratios, are also outlined. In the weak sector, we describe the role of TPE and gamma-Z interference in parity-violating electron scattering, and assess their impact on the extraction of the strange form factors of the nucleon and the weak charge of the proton.Comment: 73 pages, 40 figures, review article for Prog. Part. Nucl. Phys. (dedicated to the memory of John A. Tjon
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