116 research outputs found

    Thermophysical Properties of an Fe_(57.75)Ni_(19.25)Mo₁₀C₅B₈ Glass‐Forming Alloy Measured in Microgravity

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    Iron‐based metallic glasses are among the lowest‐cost form of amorphous metals and have numerous potential applications, such as wear‐resistant coatings, cutting tools, and gears. There is an increased interest for using this novel alloys as protective coatings and to produce structural elements by additive manufacturing. If an accelerated process development is desired, computer‐based process simulations are nowadays a vital tool. As a consequence, high‐quality measurements of the thermophysical properties in the solid and liquid phases are essential for developing numerical simulation models and suitable processing parameters. Due to the high melt reactivity of liquid metals at high temperatures, measurements using conventional containers are challenging, hence containerless methods have to be used. Herein, the thermophysical properties of an Fe‐based metallic glass‐former have been measured in the liquid phase using the electromagnetic levitator ISS‐EML on‐board the International Space Station (ISS)

    Metabolic engineering of apple by overexpression of the MdMyb10 gene

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    Flavonoids are low-molecular-weight phenolic compounds that are widely distributed in the plant kingdom. They have different roles in plant resistance to biotic and abiotic stresses. The transcription factor gene MdMyb10 (Gene Bank: DQ267896) was introduced into two apple (Malus domestica Borkh.) cultivars i.e. ‘Holsteiner Cox (HC)’ and ‘Gala’ via Agrobacterium-mediated transformation. The regenerated shoots were selected on kanamycin containing media. The presence of additional MdMyb10 gene in putative shoots was confirmed by PCR, RT-PCR and Southern blotting. Expression level of introduced MdMyb10 gene was analyzed by quantitative real time PCR. The results confirmed a dramatic increase in overexpression of MdMyb10 in the transgenic plants, up to 1261 and 847-folds for cultivars Holsteiner Cox and Gala, respectively compared to non-transformed negative control plants. HPLC-MS was used to determine the levels of different flavonoid compounds in both non-transgenic and transgenic plants. In MdMyb10 ‘HC’ transgenic plants, some of the polyphenols analyzed were enhanced while others were reduced in comparison to their levels in the non-transgenic plants. On the other hand, all of the analyzed polyphenol classes were induced in MdMyb10 ‘Gala’ transgenic plants in comparison to their levels in the non-transgenic plants. In the present study, the flavonoid pathway was successfully modified in apple by overexpressing the MdMyb10 transcription factor to validate the hypothesis of increased effect on plant disease resistance.Islamic Development Ban

    Unusual evolution of a catalytic core element in CCA-adding enzymes

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    CCA-adding enzymes are polymerases existing in two distinct enzyme classes that both synthesize the C-C-A triplet at tRNA 3′-ends. Class II enzymes (found in bacteria and eukaryotes) carry a flexible loop in their catalytic core required for switching the specificity of the nucleotide binding pocket from CTP- to ATP-recognition. Despite this important function, the loop sequence varies strongly between individual class II CCA-adding enzymes. To investigate whether this loop operates as a discrete functional entity or whether it depends on the sequence context of the enzyme, we introduced reciprocal loop replacements in several enzymes. Surprisingly, many of these replacements are incompatible with enzymatic activity and inhibit ATP-incorporation. A phylogenetic analysis revealed the existence of conserved loop families. Loop replacements within families did not interfere with enzymatic activity, indicating that the loop function depends on a sequence context specific for individual enzyme families. Accordingly, modeling experiments suggest specific interactions of loop positions with important elements of the protein, forming a lever-like structure. Hence, although being part of the enzyme’s catalytic core, the loop region follows an extraordinary evolutionary path, independent of other highly conserved catalytic core elements, but depending on specific sequence features in the context of the individual enzymes

    Hop/Sti1 – A Two-Faced Cochaperone Involved in Pattern Recognition Receptor Maturation and Viral Infection

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    Perception of pathogens by host pattern recognition receptors (PRRs) or R proteins is a prerequisite to promote successful immune responses. The Hsp70/Hsp90 organizing protein Hop/Sti1, a multifunctional cochaperone, has been implicated in the maturation of a receptor-like kinase (RLK) necessary for chitin sensing. However, it remains unknown whether Hop/Sti1 is generally participating in PRR genesis. Using RNA-interference (RNAi), we silenced Hop/Sti1 expression in Nicotiana tabacum to gain further insight into the role of the cochaperone in plant defense responses. As expected, transgenic plants do not respond to chitin treatment anymore. In contrast to this, trafficking and functionality of the flagellin PRR FLS2 were unaltered, suggesting a selective involvement of Hop/Sti1 during PRR maturation. Furthermore, Hop/Sti1 was identified as a cellular determinant of Potato virus Y (PVY) symptom development in tobacco, since PVY was able to accumulate to near wild-type level without provoking the usual veinal necrosis phenotype. In addition, typical antiviral host defense responses were suppressed in the transgenic plants. These data suggest that perception of PVY is dependent on Hop/Sti1-mediated receptor maturation, while viral symptoms represent a failing attempt to restrict PVY spread. In addition, Hop/Sti1 colocalized with virus-induced membrane aggregates in wild-type plants. The retention of Hop/Sti1 in potential viral replication complexes suggests a role during viral translation/replication, explaining why RNAi-lines do not exhibit increased susceptibility to PVY. This study provides evidence for a dual role of Hop/Sti1 in PRR maturation and pathogen perception as well as in promoting viral proliferation

    Transplantation of progenitor cells and regeneration enhancement in acute myocardial infarction Final one-year results of the TOPCARE-AMI Trial

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    ObjectivesThe Transplantation of Progenitor Cells And Regeneration Enhancement in Acute Myocardial Infarction (TOPCARE-AMI) trial investigates both safety, feasibility, and potential effects on parameters of myocardial function of intracoronary infusion of either circulating progenitor cells (CPC) or bone marrow-derived progenitor cells (BMC) in patients with acute myocardial infarction (AMI).BackgroundIn animal experiments, therapy with adult progenitor cells was shown to improve vascularization, left ventricular (LV) remodeling, and contractility after AMI.MethodsA total of 59 patients with AMI were randomly assigned to receive either CPC (n = 30) or BMC (n = 29) into the infarct artery at 4.9 ± 1.5 days after AMI.ResultsIntracoronary progenitor cell application did not incur any measurable ischemic myocardial damage, but one patient experienced distal embolization before cell therapy. During hospital follow-up, one patient in each cell group developed myocardial infarction; one of these patients died of cardiogenic shock. No further cardiovascular events, including ventricular arrhythmias or syncope, occurred during one-year follow-up. By quantitative LV angiography at four months, LV ejection fraction (EF) significantly increased (50 ± 10% to 58 ± 10%; p < 0.001), and end-systolic volumes significantly decreased (54 ± 19 ml to 44 ± 20 ml; p < 0.001), without differences between the two cell groups. Contrast-enhanced magnetic resonance imaging after one year revealed an increased EF (p < 0.001), reduced infarct size (p < 0.001), and absence of reactive hypertrophy, suggesting functional regeneration of the infarcted ventricles.ConclusionsIntracoronary infusion of progenitor cells (either BMC or CPC) is safe and feasible in patients after AMI successfully revascularized by stent implantation. Both the excellent safety profile and the observed favorable effects on LV remodeling, provide the rationale for larger randomized double-blind trials

    New insights into the prevalence of depressive symptoms and depression in rheumatoid arthritis – Implications from the prospective multicenter VADERA II study

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    Objectives To investigate the prevalence of depressive symptoms in rheumatoid arthritis (RA) patients using two previously validated questionnaires in a large patient sample, and to evaluate depressive symptoms in the context of clinical characteristics (e.g. remission of disease) and patient-reported impact of disease. Methods In this cross-sectional study, the previously validated Patient Health Questionnaire (PHQ-9) and Beck-Depression Inventory II (BDI-II) were used to assess the extent of depressive symptoms in RA patients. Demographic background, RA disease activity score (DAS28), RA impact of disease (RAID) score, comorbidities, anti-rheumatic therapy and antidepressive treatment, were recorded. Cut-off values for depressive symptomatology were PHQ-9 ≥5 or BDI-II ≥14 for mild depressive symptoms or worse and PHQ-9 ≥ 10 or BDI-II ≥ 20 for moderate depressive symptoms or worse. Prevalence of depressive symptomatology was derived by frequency analysis while factors independently associated with depressive symptomatology were investigated by using multiple logistic regression analyses. Ethics committee approval was obtained, and all patients provided written informed consent before participation. Results In 1004 RA-patients (75.1% female, mean±SD age: 61.0±12.9 years, mean disease duration: 12.2±9.9 years, DAS28 (ESR): 2.5±1.2), the prevalence of depressive symptoms was 55.4% (mild or worse) and 22.8% (moderate or worse). Characteristics independently associated with depressive symptomatology were: age 2 (OR = 10.54) and presence of chronic pain (OR = 3.25). Of patients classified as having depressive symptoms, only 11.7% were receiving anti-depressive therapy. Conclusions Mild and moderate depressive symptoms were common in RA patients according to validated tools. In routine clinical practice, screening for depression with corresponding follow-up procedures is as relevant as incorporating these results with patient-reported outcomes (e.g. symptom state), because the mere assessment of clinical disease activity does not sufficiently reflect the prevalence of depressive symptoms. Clinical trial registration number This study is registered in the Deutsches Register Klinischer Studien (DRKS00003231) and ClinicalTrials.gov (NCT02485483)

    The multicenter effectiveness study of inpatient and day hospital treatment in departments of psychosomatic medicine and psychotherapy in Germany

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    Background: Reliable outcome data of psychosomatic inpatient and day hospital treatment with a focus on psychotherapy are important to strengthen ecological validity by assessing the reality of mental health care in the field. This study aims to evaluate the effectiveness of inpatient and day hospital treatment in German university departments of Psychosomatic Medicine and Psychotherapy in a prospective, naturalistic, multicenter design including structured assessments. Methods: Structured interviews were used to diagnose mental disorders according to ICD-10 and DSM-IV at baseline. Depression, anxiety, somatization, eating disorder and posttraumatic stress disorder (PTSD) symptoms, as well as personality functioning were assessed by means of questionnaires on admission and at discharge. Results: 2,094 patients recruited by 19 participating university hospitals consented to participation in the study. Effect sizes for each of the outcome criteria were calculated for 4–5 sub-groups per outcome domain with differing severity at baseline. Pre-post effect sizes for patients with moderate and high symptom severity at baseline ranged from d = 0.78 to d = 3.61 with symptoms of PTSD, depression, and anxiety showing the largest and somatization as well as personality functioning showing somewhat smaller effects. Conclusions: Inpatient and day hospital treatment in German university departments of Psychosomatic Medicine and Psychotherapy is effective under field conditions. Clinical trial registration: https://drks.de/search/de/trial/DRKS00016412, identifier: DRKS00016412
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