148 research outputs found
Investigation of A1g phonons in YBa2Cu3O7 by means of LAPW atomic-force calculations
We report first-principles frozen-phonon calculations for the determination
of the force-free geometry and the dynamical matrix of the five Raman-active
A1g modes in YBa2Cu3O7. To establish the shape of the phonon potentials atomic
forces are calculated within the LAPW method. Two different schemes - the local
density approximation (LDA) and a generalized gradient approximation (GGA) -
are employed for the treatment of electronic exchange and correlation effects.
We find that in the case of LDA the resulting phonon frequencies show a
deviation from experimental values of approximately -10%. Invoking GGA the
frequency values are significantly improved and also the eigenvectors are in
very good agreement with experimental findings.Comment: 15 page
Engagement 2.0. Vom passiven Wahrnehmen zum aktiven Nutzen neuer Kommunikationstechnologien
Im vorliegenden Beitrag beschreiben die Autoren einen seit zwei Jahren am Bundesinstitut für Erwachsenenbildung situierten Kurs, der engagierte Menschen in die Kommunikationstechniken und -werkzeuge im sogenannten Web 2.0 einführt. Als "politische Kommunikation" betrachten sie alle öffentlichkeitswirksamen bzw. zielgruppenbezogenen Aktivitäten für Anliegen, die im Selbstbewusstsein der AkteurInnen als öffentlich, als Interessen der Allgemeinheit oder aber auch als moralische Ansprüche an die Gesellschaft verstanden werden. Den Abschluss des Beitrages bildet der Ausblick auf eine im Entstehen befindliche Webcommunity der AbsolventInnen des Kurses. (DIPF/Orig.)The authors of the present article describe a course at the Austrian Federal Institute of Adult Education (bifeb) that has introduced dedicated people to Web 2.0 communication technologies and tools for the last two years. For the authors, “political communication” represents all public-oriented and target group related activities surrounding matters that are considered to be public in the self-awareness of those involved, interests of the general public or also moral demands on society. The end of the article provides a panorama of the web community that is being created by the course graduates. (DIPF/Orig.
Infrared optical properties of Pr2CuO4
The ab-plane reflectance of a Pr2CuO4 single crystal has been measured over a
wide frequency range at a variety of temperatures, and the optical properties
determined from a Kramers-Kronig analysis. Above ~ 250 K, the low frequency
conductivity increases quickly with temperature; the resistivity follows the
form e^(E_a/k_BT), where E_a ~ 0.17 eV is much less than the inferred optical
gap of ~ 1.2 eV. Transport measurements show that at low temperature the
resistivity deviates from activated behavior and follows the form
e^[(T_0/T)^1/4], indicating that the dc transport in this material is due to
variable-range hopping between localized states in the gap. The four
infrared-active Eu modes dominate the infrared optical properties. Below ~ 200
K, a striking new feature appears near the low-frequency Eu mode, and there is
additional new fine structure at high frequency. A normal coordinate analysis
has been performed and the detailed nature of the zone-center vibrations
determined. Only the low-frequency Eu mode has a significant Pr-Cu interaction.
Several possible mechanisms related to the antiferromagnetism in this material
are proposed to explain the sudden appearance of this and other new spectral
features at low temperature.Comment: 11 pages, 7 embedded EPS figures, REVTeX
Delayed contrast-enhanced cardiac MRI at an open 1.0T MR-system comparison of conventional segmented 3D gradient echo and phase-sensitive inversion recovery sequences: initial results
Unusual multisystemic involvement and a novel BAG3 mutation revealed by NGS screening in a large cohort of myofibrillar myopathies
Background: Myofibrillar myopathies (MFM) are a group of phenotypically and genetically heterogeneous neuromuscular disorders, which are characterized by protein aggregations in muscle fibres and can be associated with multisystemic involvement. Methods: We screened a large cohort of 38 index patients with MFM for mutations in the nine thus far known causative genes using Sanger and next generation sequencing (NGS). We studied the clinical and histopathological characteristics in 38 index patients and five additional relatives (n = 43) and particularly focused on the associated multisystemic symptoms. Results: We identified 14 heterozygous mutations (diagnostic yield of 37%), among them the novel p.Pro209Gln mutation in the BAG3 gene, which was associated with onset in adulthood, a mild phenotype and an axonal sensorimotor polyneuropathy, in the absence of giant axons at the nerve biopsy. We revealed several novel clinical phenotypes and unusual multisystemic presentations with previously described mutations: hearing impairment with a FLNC mutation, dysphonia with a mutation in DES and the first patient with a FLNC mutation presenting respiratory insufficiency as the initial symptom. Moreover, we described for the first time respiratory insufficiency occurring in a patient with the p.Gly154Ser mutation in CRYAB. Interestingly, we detected a polyneuropathy in 28% of the MFM patients, including a BAG3 and a MYOT case, and hearing impairment in 13%, including one patient with a FLNC mutation and two with mutations in the DES gene. In four index patients with a mutation in one of the MFM genes, typical histological findings were only identified at the ultrastructural level (29%). Conclusions: We conclude that extraskeletal symptoms frequently occur in MFM, particularly cardiac and respiratory involvement, polyneuropathy and/or deafness. BAG3 mutations should be considered even in cases with a mild phenotype or an adult onset. We identified a genetic defect in one of the known genes in less than half of the MFM patients, indicating that more causative genes are still to be found. Next generation sequencing techniques should be helpful in achieving this aim
Qualität der Arbeit, Beschäftigung und Beschäftigungsfähigkeit im Wechselspiel von Technologie, Organisation und Qualifikation - Querschnittsanalyse: Projektabschlussbericht
Das vom Bundesministerium für Arbeit und Soziales (BMAS) geförderte Forschungsprojekt QuaTOQ (Qualität der Arbeit, Beschäftigung und Beschäftigungsfähigkeit im Wechselspiel von Technologie, Organisation und Qualifikation) untersucht für acht verschiedene Branchen zukünftige Arbeitsformen und -inhalte vor dem Hintergrund einer weiterhin zunehmenden Technisierung, vor allem aber Digitalisierung. Die hier vorgelegte vertiefende Querschnittsanalyse baut auf diesen Branchenberichten auf und analysiert branchenspezifische und branchenübergreifende Trends. Drei Querschnittsthemen werden aufgrund der empirischen Ergebnisse als besonders zukunftsweisend vertieft behandelt: psychische Belastungsmuster, künftiger Wandel von Berufs- und Kompetenzbilder und Plattformökonomie
Distinct muscle imaging patterns in myofibrillar myopathies
Objective: To compare muscle imaging findings in different subtypes of myofibrillar myopathies (MFM) in order to identify characteristic patterns of muscle alterations that may be helpful to separate these genetic heterogeneous muscular disorders. Methods: Muscle imaging and clinical findings of 46 patients with MFM were evaluated (19 desminopathy, 12 myotilinopathy, 11 filaminopathy, 1 alpha B-crystallinopathy, and 3 ZASPopathy). The data were collected retrospectively in 43 patients and prospectively in 3 patients. Results: In patients with desminopathy, the semitendinosus was at least equally affected as the biceps femoris, and the peroneal muscles were never less involved than the tibialis anterior (sensitivity of these imaging criteria to detect desminopathy in our cohort 100%, specificity 95%). In most of the patients with myotilinopathy, the adductor magnus showed more alterations than the gracilis muscle, and the sartorius was at least equally affected as the semitendinosus (sensitivity 90%, specificity 93%). In filaminopathy, the biceps femoris and semitendinosus were at least equally affected as the sartorius muscle, and the medial gastrocnemius was more affected than the lateral gastrocnemius. The semimembranosus mostly showed more alterations than the adductor magnus (sensitivity 88%, specificity 96%). Early adult onset and cardiac involvement was most often associated with desminopathy. In patients with filaminopathy, muscle weakness typically beginning in the 5th decade of life was mostly pronounced proximally, while late adult onset (> 50 years) with distal weakness was more often present in myotilinopathy. Conclusions: Muscle imaging in combination with clinical data may be helpful for separation of distinct myofibrillar myopathy subtypes and in scheduling of genetic analysis
The slow-releasing and mitochondria-targeted hydrogen sulfide (H2s) delivery molecule ap39 induces brain tolerance to ischemia
This is the final version. Available on open access from MDPI via the DOI in this recordIschemic stroke is the third leading cause of death in the world, which accounts for almost 12% of the total deaths worldwide. Despite decades of research, the available and effective pharmacotherapy is limited. Some evidence underlines the beneficial properties of hydrogen sulfide (H2S) donors, such as NaSH, in an animal model of brain ischemia and in in vitro research; however, these data are ambiguous. This study was undertaken to verify the neuroprotective activity of AP39, a slow-releasing mitochondria-targeted H2S delivery molecule. We administered AP39 for 7 days prior to ischemia onset, and the potential to induce brain tolerance to ischemia was verified. To do this, we used the rat model of 90-min middle cerebral artery occlusion (MCAO) and used LC-MS/MS, RT-PCR, Luminex™ assays, Western blot and immunofluorescent double-staining to determine the absolute H2S levels, inflammatory markers, neurotrophic factor signaling pathways and apoptosis marker in the ipsilateral frontal cortex, hippocampus and in the dorsal striatum 24 h after ischemia onset. AP39 (50 nmol/kg) reduced the infarct volume, neurological deficit and reduced the microglia marker (Iba1) expression. AP39 also exerted prominent anti-inflammatory activity in reducing the release of Il-1β, Il-6 and TNFα in brain areas particularly affected by ischemia. Furthermore, AP39 enhanced the pro-survival pathways of neurotrophic factors BDNF-TrkB and NGF-TrkA and reduced the proapoptotic proNGF-p75NTR-sortilin pathway activity. These changes corresponded with reduced levels of cleaved caspase 3. Altogether, AP39 treatment induced adaptative changes within the brain and, by that, developed brain tolerance to ischemia.National Science Center, PolandMedical Research Council (MRC
The additional value of first pass myocardial perfusion imaging during peak dose of dobutamine stress cardiac MRI for the detection of myocardial ischemia
Purpose of this study was to assess the additional value of first pass myocardial perfusion imaging during peak dose of dobutamine stress Cardiac-MR (CMR). Dobutamine Stress CMR was performed in 115 patients with an inconclusive diagnosis of myocardial ischemia on a 1.5 T system (Magnetom Avanto, Siemens Medical Systems). Three short-axis cine and grid series were acquired during rest and at increasing doses of dobutamine (maximum 40 μg/kg/min). On peak dose dobutamine followed immediately by a first pass myocardial perfusion imaging sequence. Images were graded according to the sixteen-segment model, on a four point scale. Ninety-seven patients showed no New (Induced) Wall Motion Abnormalities (NWMA). Perfusion imaging showed absence of perfusion deficits in 67 of these patients (69%). Perfusion deficits attributable to known previous myocardial infarction were found in 30 patients (31%). Eighteen patients had NWMA, indicative for myocardial ischemia, of which 14 (78%) could be confirmed by a corresponding perfusion deficit. Four patients (22%) with NWMA did not have perfusion deficits. In these four patients NWMA were caused by a Left Bundle Branch Block (LBBB). They were free from cardiac events during the follow-up period (median 13.5 months; range 6–20). Addition of first-pass myocardial perfusion imaging during peak-dose dobutamine stress CMR can help to decide whether a NWMA is caused by myocardial ischemia or is due to an (inducible) LBBB, hereby preventing a false positive wall motion interpretation
Serum Tumor Markers and Outcomes in Patients With Appendiceal Adenocarcinoma
IMPORTANCE: Serum tumor markers carcinoembryonic antigen (CEA), carbohydrate antigen 19-9 (CA19-9), and cancer antigen 125 (CA125) have been useful in the management of gastrointestinal and gynecological cancers; however, there is limited information regarding their utility in patients with appendiceal adenocarcinoma.
OBJECTIVE: To assess the association of serum tumor markers (CEA, CA19-9, and CA125) with clinical outcomes and pathologic and molecular features in patients with appendiceal adenocarcinoma.
DESIGN, SETTING, AND PARTICIPANTS: This is a retrospective cohort study at a single tertiary care comprehensive cancer center. The median (IQR) follow-up time was 52 (21-101) months. Software was used to query the MD Anderson internal patient database to identify patients with a diagnosis of appendiceal adenocarcinoma and at least 1 tumor marker measured at MD Anderson between March 2016 and May 2023. Data were analyzed from January to December 2023.
MAIN OUTCOMES AND MEASURES: Association of serum tumor markers with survival in patients with appendiceal adenocarcinoma. Cox proportional hazards regression analyses were also performed to assess associations between clinical factors (serum tumor marker levels, demographics, and patient and disease characteristics) and patient outcomes (overall survival).
RESULTS: A total of 1338 patients with appendiceal adenocarcinoma were included, with a median (range) age at diagnosis of 56.5 (22.3-89.6) years. The majority of the patients had metastatic disease (1080 patients [80.7%]). CEA was elevated in 742 of the patients tested (56%), while CA19-9 and CA125 were elevated in 381 patients (34%) and 312 patients (27%), respectively. Individually, elevation of CEA, CA19-9, or CA125 were associated with worse 5-year survival; elevated vs normal was 81% vs 95% for CEA (hazard ratio [HR], 4.0; 95% CI, 2.9-5.6), 84% vs 92% for CA19-9 (HR, 2.2; 95% CI, 1.4-3.4), and 69% vs 93% for CA125 (HR, 4.6; 95% CI, 2.7-7.8) (P \u3c .001 for all). Quantitative evaluation of tumor markers was associated with outcomes. Patients with highly elevated (top 10th percentile) CEA, CA19-9, or CA125 had markedly worse survival, with 5-year survival rates of 59% for CEA (HR, 9.8; 95% CI, 5.3-18.0), 64% for CA19-9 (HR, 6.0; 95% CI, 3.0-11.7), and 57% for CA125 (HR, 7.6; 95% CI, 3.5-16.5) (P \u3c .001 for all). Although metastatic tumors had higher levels of all tumor markers, when restricting survival analysis to 1080 patients with metastatic disease, elevated CEA, CA19-9, or CA125 were all still associated worse survival (HR for CEA, 3.4; 95% CI, 2.5-4.8; P \u3c .001; HR for CA19-9, 1.8; 95% CI, 1.2-2.7; P = .002; and HR for CA125, 3.9; 95% CI, 2.4-6.4; P \u3c .001). Interestingly, tumor grade was not associated with CEA or CA19-9 level, while CA-125 was slightly higher in high-grade tumors relative to low-grade tumors (mean value, 18.3 vs 15.0; difference, 3.3; 95% CI, 0.9-3.7; P \u3c .001). Multivariable analysis identified an incremental increase in the risk of death with an increase in the number of elevated tumor markers, with an 11-fold increased risk of death in patients with all 3 tumor markers elevated relative to those with none elevated. Somatic mutations in KRAS and GNAS were associated with significantly higher levels of CEA and CA19-9.
CONCLUSIONS AND RELEVANCE: In this retrospective study of serum tumor markers in patients with appendiceal adenocarcinoma, CEA, CA19-9, and CA125 were associated with overall survival in appendiceal adenocarcinoma. Given their value, all 3 biomarkers should be included in the initial workup of patients with a diagnosis of appendiceal adenocarcinoma
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