510 research outputs found

    In-Situ Mechanical Property Evaluation of Dielectric Ceramics in Multilayer Capacitors

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    The Young's modulus, hardness, and fracture toughness of barium titanate dielectric ceramics in three commercially available multilayer capacitors (MLCs) were measured in-situ using indentation and a mechanical properties microprobe. The three MLCs were equivalent in size (0805), capacitance (0.1 uF) and dielectric type (X7R). The Young's modulus and hardness of the dielectric ceramics in the three MLCs were similar, while there were statistically significant differences in their fracture toughnesses. The results provide insight into the assessment of MLC mechanical reliability, and show that equivalent electrical MLC rating is not necessarily a guarantee that the dielectric ceramics in them will exhibit equivalent mechanical performance

    Identifying new potential biomarkers in adrenocortical tumors based on mrna expression data using machine learning

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    Adrenocortical carcinoma (ACC) is a rare disease, associated with poor survival. Several “multiple-omics” studies characterizing ACC on a molecular level identified two different clusters correlating with patient survival (C1A and C1B). We here used the publicly available transcriptome data from the TCGA-ACC dataset (n = 79), applying machine learning (ML) methods to classify the ACC based on expression pattern in an unbiased manner. UMAP (uniform manifold approximation and projection)-based clustering resulted in two distinct groups, ACC-UMAP1 and ACC-UMAP2, that largely overlap with clusters C1B and C1A, respectively. However, subsequent use of random-forest-based learning revealed a set of new possible marker genes showing significant differential expression in the described clusters (e.g., SOAT1, EIF2A1). For validation purposes, we used a secondary dataset based on a previous study from our group, consisting of 4 normal adrenal glands and 52 benign and 7 malignant tumor samples. The results largely confirmed those obtained for the TCGA-ACC cohort. In addition, the ENSAT dataset showed a correlation between benign adrenocortical tumors and the good prognosis ACC cluster ACC-UMAP1/C1B. In conclusion, the use of ML approaches re-identified and redefined known prognostic ACC subgroups. On the other hand, the subsequent use of random-forest-based learning identified new possible prognostic marker genes for ACC

    Gene expression profiling of brains from bovine spongiform encephalopathy (BSE)-infected cynomolgus macaques

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    BACKGROUND: Prion diseases are fatal neurodegenerative disorders whose pathogenesis mechanisms are not fully understood. In this context, the analysis of gene expression alterations occurring in prion-infected animals represents a powerful tool that may contribute to unravel the molecular basis of prion diseases and therefore discover novel potential targets for diagnosis and therapeutics. Here we present the first large-scale transcriptional profiling of brains from BSE-infected cynomolgus macaques, which are an excellent model for human prion disorders. RESULTS: The study was conducted using the GeneChip\uae Rhesus Macaque Genome Array and revealed 300 transcripts with expression changes greater than twofold. Among these, the bioinformatics analysis identified 86 genes with known functions, most of which are involved in cellular development, cell death and survival, lipid homeostasis, and acute phase response signaling. RT-qPCR was performed on selected gene transcripts in order to validate the differential expression in infected animals versus controls. The results obtained with the microarray technology were confirmed and a gene signature was identified. In brief, HBB and HBA2 were down-regulated in infected macaques, whereas TTR, APOC1 and SERPINA3 were up-regulated. CONCLUSIONS: Some genes involved in oxygen or lipid transport and in innate immunity were found to be dysregulated in prion infected macaques. These genes are known to be involved in other neurodegenerative disorders such as Alzheimer's and Parkinson's diseases. Our results may facilitate the identification of potential disease biomarkers for many neurodegenerative diseases

    Модернизация конструкции биологического лабораторного комплекса

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    Объектом модернизации в данной работе является конструкция биологического лабораторного комплекса. Цель: модернизация конструкции биологического лабораторного комплекса. Результатом процесса модернизации является конструкция комплекса в CAD системе SolidWorks. В ходе работы: модернизирована конструкция комплекса под заданные характеристики, разработан сборочный чертеж, спроектирован технологический процесс изготовления детали типа фланец.The object of modernization in this work is the construction of a biological laboratory complex. Purpose: modernization of the biological laboratory complex. The result of the modernization process is the design of the complex in the CAD system SolidWorks. In the course of work: the design of the complex has been modernized for the given characteristics, an assembly drawing has been developed, a technological process has been designed for manufacturing a flange type part

    Cortisol excess in patients with primary aldosteronism impacts on left ventricular hypertrophy

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    Context Primary aldosteronism (PA) represents the most frequent form of endocrine hypertension. Hyperaldosteronism and hypercortisolism both induce excessive left ventricular hypertrophy (LVH) compared to matched essential hypertensives. In recent studies frequent co-secretion of cortisol and aldosterone has been reported in PA patients. Objective Our aim was to investigate the impact of cortisol co-secretion on left ventricular hypertrophy in PA patients. We determined 24-h excretion of mineralocorticoids and glucocorticoids by gas chromatography-mass spectrometry and assessed cardiac remodeling using echocardiography initially and one year after initiation of treatment for PA. Patients We included 73 patients from the Munich center of the German Conn's registry; 45 with unilateral aldosterone-producing adenoma and 28 with bilateral adrenal hyperplasia. Results At the time of diagnosis, 85% of PA patients showed left ventricular hypertrophy according to left ventricular mass index (LVMI, median 62.4 g/m2.). LVMI correlated positively with total glucocorticoid excretion (r2=0.076, p=0.018) as well as with tetrahydroaldosterone excretion (r2=0.070, p=0.024). Adrenalectomy led to significantly reduced LVMI in aldosterone-producing adenoma (p<0.001) while mineralocorticoid receptor antagonist therapy in bilateral adrenal hyperplasia patients reduced LVMI to a lesser degree (p=0.024). In multivariate analysis, the decrease in LVMI was positively correlated with total glucocorticoid excretion and systolic 24-hour blood pressure, but not with tetrahydroaldosterone excretion. Conclusion Cortisol excess appears to have an additional impact on cardiac remodeling in patients with PA. Treatment of PA by either adrenalectomy or mineralocorticoid receptor antagonist improves LVMI. This effect was most pronounced in patients with high total glucocorticoid excretion

    Identification and validation of multiple cell surface markers of clinical-grade adipose-derived mesenchymal stromal cells as novel release criteria for good manufacturing practice-compliant production

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    Background: Clinical translation of mesenchymal stromal cells (MSCs) necessitates basic characterization of the cell product since variability in biological source and processing of MSCs may impact therapeutic outcomes. Although expression of classical cell surface markers (e.g., CD90, CD73, CD105, and CD44) is used to define MSCs, identification of functionally relevant cell surface markers would provide more robust release criteria and options for quality control. In addition, cell surface expression may distinguish between MSCs from different sources, including bone marrow-derived MSCs and clinical-grade adipose-derived MSCs (AMSCs) grown in human platelet lysate (hPL). Methods: In this work we utilized quantitative PCR, flow cytometry, and RNA-sequencing to characterize AMSCs grown in hPL and validated non-classical markers in 15 clinical-grade donors. Results: We characterized the surface marker transcriptome of AMSCs, validated the expression of classical markers, and identified nine non-classical markers (i.e., CD36, CD163, CD271, CD200, CD273, CD274, CD146, CD248, and CD140B) that may potentially discriminate AMSCs from other cell types. More importantly, these markers exhibit variability in cell surface expression among different cell isolates from a diverse cohort of donors, including freshly prepared, previously frozen, or proliferative state AMSCs and may be informative when manufacturing cells. Conclusions: Our study establishes that clinical-grade AMSCs expanded in hPL represent a homogeneous cell culture population according to classical markers,. Additionally, we validated new biomarkers for further AMSC characterization that may provide novel information guiding the development of new release criteria

    Loss of histone methyltransferase Ezh2 stimulates an osteogenic transcriptional program in chondrocytes but does not affectcartilage development

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    Ezh2 is a histone methyltransferase that suppresses osteoblast maturation and skeletal development. We evaluated the roleof Ezh2 in chondrocyte lineage differentiation and endochondral ossification. Ezh2 was genetically inactivated in the mesenchymal, osteoblastic, and chondrocytic lineages in mice using the Prrx1-Cre,Osx1-Cre, and Col2a1-Cre drivers, respectively. Wild-type and conditional knockout mice were phenotypically assessed by grossmorphology, histology, and micro-CT imaging. Ezh2-deficient chondrocytes in micromass culture models were evaluated usingRNA-sequencing, histologic evaluation, and western blotting. Aged mice with Ezh2 deficiency were also evaluated for prematuredevelopment of osteoarthritis using radiographic analysis. Ezh2 deficiency in murine chondrocytes reduced bone density at 4 weeks of age, although caused no other gross developmentaleffects. Knockdown of Ezh2 in chondrocyte micromass cultures resulted in a global reduction in trimethylation of histone 3lysine 27 (H3K27me3) and altered differentiation in vitro. RNA-seq analysis revealed enrichment of an osteogenic gene expressionprofile in Ezh2 deficient chondrocytes. Joint development proceeded normally in the absence of Ezh2 in chondrocytes withoutinducing excessive hypertrophy or premature osteoarthritis in vivo. In summary, loss of Ezh2 reduced H3K27me3 levels, increased expression of osteogenic genes in chondrocytes, and resulted ina transient post-natal bone phenotype. Remarkably, Ezh2 activity is dispensable for normal chondrocyte maturation and endochondralossification in vivo, even though it appears to have a critical role during early stages of mesenchymal lineage-commitment

    Electrochemical and antimicrobial properties of diamond like carbon-metal composite films

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    ABSTRACT Implants containing antimicrobial metals may reduce morbidity, mortality, and healthcare costs associated with medical device-related infections. We have deposited diamondlike carbonsilver (DLC-Ag), diamondlike carbon-platinum (DLC-Pt), and diamondlike carbon-silverplatinum (DLC-AgPt) thin films using a multicomponent target pulsed laser deposition process. Transmission electron microscopy of the DLC-silver and DLC-platinum composite films revealed that the silver and platinum self-assemble into nanoparticle arrays within the diamondlike carbon matrix. The diamondlike carbon-silver film possesses hardness and Young&apos;s modulus values of 37 GPa and 331 GPa, respectively. The diamondlike carbon-metal composite films exhibited passive behavior at open-circuit potentials. Low corrosion rates were observed during testing in a phosphate-buffered saline (PBS) electrolyte. In addition, the diamondlike carbon-metal composite films were found to be immune to localized corrosion below 1000 mV (SCE). DLC-silver-platinum films demonstrated exceptional antimicrobial properties against Staphylococcus bacteria. It is believed that a galvanic couple forms between platinum and silver, which accelerates silver ion release and provides more robust antimicrobial activity. Diamondlike carbon-silver-platinum films may provide unique biological functionalities and improved lifetimes for cardiovascular, orthopaedic, biosensor, and implantable microelectromechanical systems
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