1,170 research outputs found
Thermal Effects for Shaft-Pre-Stress on Rotor Dynamic System
This Paper outlines study behaviour of rotating shaft with high speed under
thermal effects. The method of obtaining the frequency response functions of a
rotor system with study whirl effect in this revision the raw data obtained
from the experimental results (using Smart Office program) are curve-fitted by
theoretical data regenerated from some of the experimental data and simulating
it using finite element (ANSYS 12). (FE) models using the Eigen analysis
capability were used to simulate the vibration. The results were compared with
experimental data show analysis data with acceptable accuracy and performance.
The rotating effect causes un-symmetry in the system matrices, resulting in
complexity in decoupling the mathematical models of the system for the purpose
of modal analysis. Different method is therefore required, which can handle
general system matrices rather than symmetrical matrices, which is normal for
passive structures. Mathematical model of the system from the test data can be
assembled. The frequency response functions are extracted, Campbell diagram are
draw and simulated. (FE) is used to carry out such as simulation since it has
good capability for Eigen analysis and also good graphical facility.
Keywords: Thermal effects, Modelling, Campbell diagram, Whirl, Rotor
dynamics.Comment: Published by: Academic Research Publishing Agency. All rights
reserved, 6 pages, 4 figures, 1 pictur
Low vitamin D serum level is associated with HDL-C dyslipidemia and increased serum thrombomodulin levels of insulin-resistant individuals
Background: Insulin-resistant individuals are known to have dyslipidemia and are predicted to be at high risk of cardiovascular events. Vitamin D deficiency was shown to be associated with dyslipidemia; however, the type of dyslipidemia associated with vitamin D deficiency in insulin-resistant individuals is not determined. Furthermore, there is evidence linking insulin resistance with low-grade inflammation suggesting levels of pro-inflammatory cytokines to be increased in insulin-resistant states. Objective: This study was performed to evaluate the impact of vitamin D deficiency, defined as serum level of 25(OH)D below 20 ng/mL, on lipid profile and inflammatory markers such as interleukin (IL-6) and IL-8, as well as soluble thrombomodulin (TM) in the serum of insulin-resistant individuals. Methods: A total of 4114 individuals had simultaneous serum 25(OH)D, insulin, and lipid panel testing during 2013 as part of the United Arab Emirates National Diabetes and Lifestyle (UAEDIAB) study. Multivariate logistic regression analysis was used to assess the association between serum level of 25(OH)D and lipid profile in insulin-sensitive versus-resistan t individuals. The lipid panel was stratified into high total cholesterol (TC: >6.2 mmol/L), high low-density lipoprotein-cholesterol (LDL-C: >2.59 mmol/L), high triglycerides (TG: >2.3 mmol/L), and low high-density lipoprotein-cholesterol (HDL-C: <1.55 mmol/L) dysli-pidemia. Furthermore, the immunomodulatory and vasculoprotective effects of 25(OH)D were assessed by measuring the levels of IL-6, IL-8, and soluble TM in serum using ELISA. Results: More than half of the 4114 individuals were insulin resistant (n=2760, 67%) and around one-fifth of them were vitamin D-deficient (n=796, 19%). After adjusting for age, gender, body mass index, smoking, ethnicity, and educational level, the only dyslipidemia associated with vitamin D-deficient-insulin-resistant individuals (OR 2.09 [95]; P=0.009) was lower HDL-C. Furthermore, deficient 25(OH)D individuals with low HDL-C levels had higher circulatory IL-6 and IL-8 levels, and higher serum soluble TM compared to individuals with sufficient 25(OH)D and normal lipid profiles (median, IL-6 pg/mL 0.82 vs 1.71, P=0.001; median, IL-8 pg/mL 51.31 vs 145.6, P=0.003; and median, soluble TM ng/mL 5.19 vs 7.38, P<0.0001; in sufficient vs deficient groups, respectively). Conclusion: The results of our study showed that in insulin-resistant individuals, vitamin Ddeficiency status is associated with HDL-C dyslipidemia and higher serum inflammatory and endothelial damage markers
Integrative systematic review meta-analysis and bioinformatics identifies MicroRNA-21 and its target genes as biomarkers for colorectal adenocarcinoma
BACKGROUND: Advanced colorectal has poor survival and are difficult to treat. Therefore, there is an urgent need
for biomarkers to diagnose this cancer at earlier manageable stages. Micro-RNAs (miRNAs) are amongst the most
significant biomarkers that have shown promise in improving management and early detection of different types
of cancers. However, since MiRNAs are non-coding, the main limitation of using them as biomarkers is that they
do not have associated phenotype and therefore difficult to validate using other techniques. This makes it difficult to understand the mechanism of miRNA is disease initiation and progression, therefore any methodology
that can provide semantics to miRNA expression would enhance the understanding of the role of miRNA in
disease.
METHODS: Here we report an integrative meta-analysis and bioinformatics methodology that showed microRNA21 and its associated target mRNA to be the most significant predictive biomarkers for colorectal adenoma and
adenocarcinoma. After drawing key inferences by meta-analysis, the authors then developed a bioinformatics
method to identify mir-21 gene targeting in a specific tissue using two different bioinformatics approaches;
absolute GSEA (Gene Set Enrichment Analysis) and LIMMA (Linear Models for MicroArray data) to identify
differentially expressed genes of miRNA-21.
RESULTS: Results from GSEA intersection with mir-21 gene targets was a subset of longer gene list that was
obtained from the GEO2R intersect. In our study, both of longer GEO2R gene target list and the more focused
GSEA list established the fact that mir-21 target numerous functional pathways that are mostly interconnected.
Our three steps bioinformatics approach identified ABCB1, HPGD, BCL2, TIAM1, TLR3, and PDCD4 as common
targets for mir-21 in both of adenoma as well as adenocarcinoma suggesting they are biomarkers for early CRC.
CONCLUSIONS: The approach in this study proposed combining the big data from the scientific literature together
with novel bioinformatics to bring about a methodology that can be used to first identify which microRNAs are
involved in a specific disease, and then to identify a panel of biomarkers derived from the microRNAs target
genes, and from these target genes the functional significance of these microRNAs can be inferred providing
better clinical value for the surgeon
First record of two hard coral species (Faviidae and Siderastreidae) from Qeshm Island (Persian Gulf, Iran)
Abstrak. Moradi M, Kamrani E, Shokri MR, Ranjbar MS, Hesni MA (2009) Rekaman pertama dua spesies karang keras (Faviidae dan
Siderastreidae) dari Pulau Qeshm (Teluk Persia, Iran). Nusantara Bioscience 2: 34-37. Dua jenis karang keras termasuk Cyphastrea
chalcidicum (Forskal 1775) (Faviidae) dan Coscinaraea monile (Forskal 1775) (Siderastreidae) dikumpulkan dari selatan Pulau Qeshm
(Teluk Persia, Iran) pada akhir tahun 2008. Spesies ini sebelumnya dilaporkan terdapat di Teluk Persia selatan, Teluk Aden, Afrika
Tenggara dan Indo-Pasifik. Tinjauan literatur pada distribusi kedua jenis mengungkapkan bahwa spesies ini pertama kali tercatat dari
Teluk Persia. Temuan ini semakin menunjukkan tingginya keragaman fauna karang di perairan Iran di bagian utara Teluk Persia.
Kata kunci: catatan pertama, Coscinaraea monile, Cyphastrea chalcidicum, Qeshm island, Persian gulf
Enhanced Expression of Autoantigens During SARS-CoV-2 Viral Infection
Immune homeostasis is disturbed during severe viral infections, which can lead to loss of tolerance to self-peptides and result in short- or long-term autoimmunity. Using publicly available transcriptomic datasets, we conducted an in-silico analyses to evaluate the expression levels of 52 autoantigens, known to be associated with 24 autoimmune diseases, during SAR-CoV-2 infection. Seven autoantigens (MPO, PRTN3, PADI4, IFIH1, TRIM21, PTPRN2, and TSHR) were upregulated in whole blood samples. MPO and TSHR were overexpressed in both lung autopsies and whole blood tissue and were associated with more severe COVID-19. Neutrophil activation derived autoantigens (MPO, PRTN3, and PADI4) were prominently increased in blood of both SARS-CoV-1 and SARS-CoV-2 viral infections, while TSHR and PTPRN2 autoantigens were specifically increased in SARS-CoV-2. Using single-cell dataset from peripheral blood mononuclear cells (PBMCs), we observed an upregulation of MPO, PRTN3, and PADI4 autoantigens within the low-density neutrophil subset. To validate our in-silico analysis, we measured plasma protein levels of two autoantigens, MPO and PRTN3, in severe and asymptomatic COVID-19. The protein levels of these two autoantigens were significantly upregulated in more severe COVID-19 infections. In conclusion, the immunopathology and severity of COVID-19 could result in transient autoimmune activation. Longitudinal follow-up studies of confirmed cases of COVID-19 could determine the enduring effects of viral infection including development of autoimmune disease
Frustration of triplet interaction in spin-glass background
Parisi demonstrated in 1979 that pairwise interactions exhibit a glass spin
phase when there is disorder. While he discovered an equilibrium solution of
the Sherrington-Kirkpatrick (SK) spin-glass model and we know it as a
continuous phase transition, the model dedicated to pairwise interactions and
higher-order interactions has not been addressed. This research intends to
determine whether this phase exists in triplet interactions. Due to the
intractable nature of the three interacting spins alone, we employed a
perturbation approach to provide an analytical solution for the triplet
interactions in the background of the SK spin-glass model. Our results show the
existence of this phase in the third-order interaction and a sudden transition
that indicates a change in the nature of a glassy spin system transitioning
from the continuous order to the first order. It causes a forward shift in the
critical temperature by identifying the frustration of triplet interactions.Comment: 6 pages, 2 figure
Cardiovascular medications and regulation of COVID-19 receptors expression
INTRODUCTION: Emerging epidemiological studies suggested that Renin–Angiotensin–Aldosterone system (RAAS) inhibitors may increase infectivity and severity of COVID-19 by modulating the expression of ACE2. METHODS: In silico analysis was conducted to compare the blood expression levels of SARS-CoV-2 entry genes between age and gender matched cohort of hypertensive patients versus control, and to determine the effect of common cardiovascular medications on the expression of COVID-19 receptors in vitro using primary human hepatocytes. RESULTS: The transcriptomic analysis revealed a significant increase of ACE2 and TMPRSS2 in the blood of patients with hypertension. Treatment of primary human hepatocytes with captopril, but not enalapril, significantly increased ACE2 expression. A similar pattern of ACE2 expression was found following the in vitro treatments of rat primary cells with captopril and enalapril. Telmisartan, a second class RAAS inhibitors, did not affect ACE2 levels. We have also tested other cardiovascular medications that may be used alone, or in combination with RAAS inhibitors. Some of these medications increased TMPRSS2, while others, like furosemide, significantly reduced COVID-19 receptors. CONCLUSIONS: The increase in ACE2 expression levels could be due to chronic use of RAAS inhibitors or alternatively caused by other hypertension-related factors or presence of other comorbidities. Treatment of common co-morbidities often require chronic use of multiple medications, which may result in an additive increase in the expression of ACE2 and TMPRSS2. Our data suggest that more research is needed to determine the effect of different medications, as well as medication combinations, on COVID-19 receptors
Defect Diagnosis in Rotors Systems by Vibrations Data Collectors Using Trending Software
Vibration measurements have been used to reliably diagnose performance
problems in machinery and related mechanical products. A vibration data
collector can be used effectively to measure and analyze the machinery
vibration content in gearboxes, engines, turbines, fans, compressors, pumps and
bearings. Ideally, a machine will have little or no vibration, indicating that
the rotating components are appropriately balanced, aligned, and well
maintained. Quick analysis and assessment of the vibration content can lead to
fault diagnosis and prognosis of a machine's ability to continue running. The
aim of this research used vibration measurements to pinpoint mechanical defects
such as (unbalance, misalignment, resonance, and part loosening), consequently
diagnosis all necessary process for engineers and technicians who desire to
understand the vibration that exists in structures and machines.
Keywords- vibration data collectors; analysis software; rotating components.Comment: 11 pages,6 figures,1 pictuer,1 schem
Can excessive wear of ceramic bearing couples be a consequence of hip squeaking?
The occurrence of Ceramic-on‐Ceramic hip squeaking in some patients is a cause for concern. Friction was shown the main reason of hip squeaking. Moreover, hip vibration significantly altered contact point path during
the gait cycle. This study investigated the effect of hip squeaking on hip implant wear
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