193 research outputs found
Does childhood trauma impact daily psychobiological stress in somatic symptom disorder? An ambulatory assessment study
Objectives: Somatic symptom disorder is characterized by excessive thoughts, feelings, and behaviors dedicated to bodily symptoms, which are often medically unexplained. Although 13% of the population are affected by this disorder, its aetiopathogenesis is not fully understood. Research in medically unexplained conditions (e.g., fibromyalgia) points to increased psychosocial stress and alterations in stress-responsive bodily systems as a potential contributing factor. This pattern has often been hypothesized to originate from early life stress, such as childhood trauma. The aim of this study was to examine, for the first time, whether individuals with somatic symptom disorder exhibit elevated levels of self-reported daily stress and alterations in the autonomic nervous system and hypothalamic-pituitary-adrenal axis, both in comparison to healthy controls and individuals with depressive disorders, and whether reports of childhood trauma influence these alterations.
Methods: A total of N = 78 individuals were recruited into this study. Of these, n = 27 had a somatic symptom disorder, n = 23 were healthy controls, and n = 28 had a depressive disorder. All individuals underwent a 14-day measurement period at home, with five assessments of self-reported stress, salivary alpha-amylase, and cortisol per day. Childhood trauma was assessed by the Childhood Trauma Questionnaire.
Results: Individuals with somatic symptom disorder exhibited higher daily stress levels (p = 0.063) as well as a less pronounced alpha-amylase awakening response (p = 0.050), compared to healthy controls (statistical trends). Moreover, they were characterized by significantly attenuated diurnal cortisol concentrations (p < 0.001). A nearly identical pattern was observed in individuals with depression. In individuals with somatic symptom disorder and depressive disorders, childhood trauma was, by trend, associated with a more pronounced alpha-amylase awakening response (b = ā0.27, p = 0.077).
Conclusions: This study provides preliminary evidence for elevated daily stress and blunted sympathetic and hypothalamic-pituitary-adrenal axis activity in individuals with somatic symptom disorder and depressive disorders. Further studies will help to uncover the conditions under which these dysregulations develop into medically unexplained vs. depressive symptoms
Remote epitaxy of InxGa1-xAs (0 0 1) on graphene covered GaAs(0 0 1) substrates
The heteroepitaxial growth of lattice mismatched layers is crucial for modern semiconductor device fabrication, but it is a significant challenge in epitaxy. Growth of lattice mismatched materials creates strain in the epitaxial layer, which is usually relaxed by introducing crystal defects deteriorating the device performance. Remote epitaxy on graphene covered substrates was recently proposed to offer a different relaxation pathway for the strained films. Here, we report on the remote heteroepitaxy growth by molecular beam epitaxy (MBE) of InxGa1-xAs-layers (0 < x 0.5) on transfer graphene covered GaAs-(0 0 1) substrates. We show that a carefully optimized plasma treatment followed by ultra-high vacuum (UHV) annealing allows InxGa1-xAs remote epitaxy on transfer graphene covered GaAs substrates. Detailed investigations on the strain relaxation of 200 nm thick InxGa1-xAs-layers on graphene covered GaAs and for comparison on bare GaAs are presented. High-resolution X-ray-diffraction (HRXRD) and transmission electron microscopy (TEM) measurements reveal single crystalline growth on large areas. On bare GaAs we observe the well-known tilt of the InxGa1-xAs-layers whereas on graphene no tilt is observed. The layers grown on graphene are more relaxed than layers grown on bare GaAs and their strain relaxation is symmetric whereas on bare GaAs the strain relaxation is stronger along the [1 1 0] direction
TDP-43 as a potential biomarker for amyotrophic lateral sclerosis:a systematic review and meta-analysis
Abstract Background Frontotemporal dementia (FTD) and Amyotrophic Lateral Sclerosis (ALS) are incurable, progressive and fatal neurodegenerative diseases with patients variably affected clinically by motor, behavior, and cognitive deficits. The accumulation of an RNA-binding protein, TDP-43, is the most significant pathological finding in approximately 95% of ALS cases and 50% of FTD cases, and discovery of this common pathological signature, together with an increasing understanding of the shared genetic basis of these disorders, has led to FTD and ALS being considered as part of a single disease continuum. Given the widespread aggregation and accumulation of TDP-43 in FTD-ALS spectrum disorder, TDP-43 may have potential as a biomarker in these diseases. Methods We therefore conducted a systematic review and meta-analysis to evaluate the diagnostic utility of TDP-43 detected in the cerebrospinal fluid (CSF) of patients with FTD-ALS spectrum disorder. Results From seven studies, our results demonstrate that patients with ALS have a statistically significantly higher level of TDP-43 in CSF (effect size 0.64, 95% CI: 0.1ā1.19, pā=ā0.02). Conclusions These data suggest promise for the use of CSF TDP-43 as a biomarker for ALS
Quantitative Histomorphometry of the Healthy Peritoneum
The peritoneum plays an essential role in preventing abdominal frictions and adhesions and can be utilized as a dialysis membrane. Its physiological ultrastructure, however, has not yet been studied systematically. 106 standardized peritoneal and 69 omental specimens were obtained from 107 patients (0.1-60 years) undergoing surgery for disease not affecting the peritoneum for automated quantitative histomorphometry and immunohistochemistry. The mesothelial cell layer morphology and protein expression pattern is similar across all age groups. Infants below one year have a thinner submesothelium; inflammation, profibrotic activity and mesothelial cell translocation is largely absent in all age groups. Peritoneal blood capillaries, lymphatics and nerve fibers locate in three distinct submesothelial layers. Blood vessel density and endothelial surface area follow a U-shaped curve with highest values in infants below one year and lowest values in children aged 7-12 years. Lymphatic vessel density is much lower, and again highest in infants. Omental blood capillary density correlates with parietal peritoneal findings, whereas only few lymphatic vessels are present. The healthy peritoneum exhibits major thus far unknown particularities, pertaining to functionally relevant structures, and subject to substantial changes with age. The reference ranges established here provide a framework for future histomorphometric analyses and peritoneal transport modeling approaches. Ā© 2016, EDP Science. All rights reserved
Effect of Piezoelectric Polarization on Phonon group velocity in Wurtzite Nitrides
We have investigated the effect of piezoelectric (PZ) polarization property
on group velocity of phonons in binary as well as in ternary wurtzite nitrides.
It is found that with the presence of PZ polarization property, the phonon
group velocity is modified. The change in phonon group velocity due to PZ
polarization effect directly depends on piezoelectric tensor value. Using
different piezoelectric tensor values recommended by different workers in the
literature, percent change in group velocities of phonons has been estimated.
The Debye temperatures and frequencies of binary nitrides GaN, AlN and InN are
also calculated using the modified group velocities. For ternary nitrides
AlxGa(1-x)N, InxGa(1-x)N and InxAl(1-x)N, the phonon group velocities have been
calculated as a functions of composition. A small positive bowing is observed
in phonon group velocities of ternary alloys. Percent variations in phonon
group velocities are also calculated for a straightforward comparison among
ternary nitrides. The results are expected to show a change in phonon
relaxation rates and thermal conductivity of III-nitrides when piezoelectric
polarization property is taken into account.Comment: 05 figures; Journal of Material science, 201
Homeostatic regulation of energetic arousal during acute social isolation: Evidence from the lab and the field
Recent evidence suggests that social contact is a basic need governed by a social homeostatic system. Little is known, however, about how conditions of altered social homeostasis affect human psychology and physiology. Here, we investigated the effects of 8 hr of social isolation on psychological and physiological variables and compared this with 8 hr of food deprivation in a lab experiment (N = 30 adult women). Social isolation led to lowered self-reported energetic arousal and heightened fatigue, comparable with food deprivation. To test whether these findings would extend to a real-life setting, we conducted a preregistered field study during a COVID-19 lockdown (N = 87 adults; 47 women). The drop in energetic arousal after social isolation observed in the lab replicated in the field study for participants who lived alone or reported high sociability, suggesting that lowered energy could be part of a homeostatic response to the lack of social contact
Detection and Quantification of Novel Cāterminal TDPā43 Fragments in ALSāTDP
The pathological hallmark of amyotrophic lateral sclerosis (ALS) is the presence of cytoplasmic inclusions, containing Cāterminal fragments of the protein TDPā43. Here, we tested the hypothesis that highly sensitive mass spectrometry with parallel reaction monitoring (MSāPRM) can generate a highāresolution map of pathological TDPā43 peptide ratios to form the basis for quantitation of abnormal Cāterminal TDPā43 fragment enrichment.Human cortex and spinal cord, microscopically staged for the presence of phosphoTDPā43, pātau, alphaāsynuclein and betaāamyloid pathology, were biochemically fractionated and analysed by immunoblot and MS for detection of fullālength and truncated (diseaseāspecific) TDPā43 peptides. This informed synthesis of heavy isotopeālabelled peptides for absolute quantification of TDPā43 by MSāPRM across 16 ALS, 8 Parkinsonās and 8 Alzheimerās disease and 8 aged control cases.We confirmed by immunoblot the previously described enrichment of pathological Cāterminal fragments in ALSāTDP urea fractions. Subsequent MS analysis resolved specific TDPā43 Nā and Cāterminal peptides, including a novel Nāterminal truncation siteāspecific peptide. Absolute quantification of peptides by MSāPRM showed an increased C:Nāterminal TDPā43 peptide ratio in ALSāTDP brain compared to normal and disease controls. A C:Nāterminal ratio >1.5 discriminated ALS from controls with a sensitivity of 100% (CI 79.6ā100) and specificity of 100% (CI 68ā100), and from Parkinsonās and Alzheimerās disease with a sensitivity of 93% (CI 70ā100) and specificity of 100% (CI 68ā100). Nāterminal truncation siteāspecific peptides were increased in ALS in line with Cāterminal fragment enrichment, but were also found in a proportion of Alzheimer cases with normal C:Nāterminal ratio but coexistent TDPā43 pathology.In conclusion this is a novel, sensitive and specific method to quantify the enrichment of pathological TDPā43 fragments in human brain, which could form the basis for an antibodyāfree assay. Our methodology has the potential to help clarify if specific pathological TDPā43 peptide signatures are associated with primary or secondary TDPā43 proteinopathies
Non-neoclassical up/down asymmetry of impurity emission on Alcator C-Mod
We demonstrate that existing theories are insufficient to explain up/down asymmetries of argon x-ray emission in Alcator C-Mod ohmic plasmas. Instead of the poloidal variation, Ʊ[subscript z]/ā©n[subscript z]āŖ, being of order the inverse aspect ratio, Ļµ, and scaling linearly with B[subscript t][superscript _ over n][subscript e]/I[2 over p], it is observed over 0.8 < r/a < 1.0 to be of order unity and exhibits a threshold behaviour between 3.5 <B[subscript t][superscript _ over n][subscript e]/I[subscript p] < 4.0 (T10[superscript 20] m[superscript ā3] MA[superscript ā1]). The transition from a poloidally symmetric to asymmetric impurity distribution is shown to occur at densities just below those that trigger a reversal of the core toroidal rotation direction, thought to be linked to the transition between the linear and saturated ohmic confinement regimes. A possible drive is discussed by which anomalous radial transport might sustain the impurity density asymmetry as the ratio of the perpendicular to parallel equilibration times, Ļ[subscript ā„,z]/Ļ[subscript ā„,z], approaches unity. This explanation requires a strong up/down asymmetry in radial flux which, while not observable on C-Mod, has been measured in TEXT and Tore Supra ohmic plasmas.United States. Dept. of Energy (Contract DE-FC02-99ER54512)United States. Dept. of Energy (Fusion Research Postdoctoral Research Program
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