•A new vibration mode for rotating blade with initial exponential function type geometric imperfection is provided.•The shallow shell theory is used and the mode involves the effect of the Coriolis ...and centrifugal force.•The effects of the geometries, imperfection and rotational speeds on the natural frequency is carried out.•It is very interesting to find that the internal resonance vibrations between modes due to imperfection.•The frequency veering phenomenon and mode shapes exchange between the modes are found due to imperfection.
The machining errors and the geometric imperfections are unavoidable, such as, local indentations, surface form error, flat curve form error and non-uniform thickness and so on. In this paper, a new vibration model for the rotating blade which is treated as a cantilever pre-twisted panel with initial exponential function type geometric imperfection is provided by using the shallow shell theory in which the torsion is considered but the two radii of curvatures are zero. Also, this mode involves the effect of the Coriolis and centrifugal force. It is assumed that the material of the pre-twisted curved panel is homogeneous and isotropic. Based on the Rayleigh–Ritz method and continuous algebraic polynomial functions satisfying the cantilever boundary conditions, the natural frequencies and mode shapes of perfect rotating pre-twisted curved panel and those with the initial geometric imperfection are computed. The validity of this model is verified by comparison with ANSYS results. A comprehensive study about the effects of the geometric parameters, imperfection size, imperfection location and the concentration degree of it, pre-twisted angles, setting angle and rotational speeds of the pre-twisted curved panel on the free vibration is carried out. The problems of frequency veering, mode shape shift, internal resonance between modes and effect of dynamic stiffness can be found.
To investigate the immune reconstruct regularity profile of KIR2DL1 and KIR3DL1 in unrelated-donor allogeneic hematopoietic stem cell transplantation (allo-HSCT) with KIR-AA genotype.
75 ...donor-recipient pairs were performed by KIR genotying using PCR-SSP, and all donors were identified with KIR-AA genotype. Dynamic detections (including unrelated-donor on the day of transplantation and the recipient each month post allo-HSCT) of the expression of KIR2DL1/3DL1 on NK cell and mRNA level were performed in 291 cases using flow cytometry (FCM) and real-time fluorescent quantitation PCR (RT-qPCR) .
①The median expression of KIR2DL1 in unrelated-donor on transplant's day was 21.60%, the median expression of KIR2DL1 in recipient 1M, 2M, 3M and 3-6M after transplantation were 7.40%, 12.00%, 16.92%, 17.64% respectively. The median expression of KIR2DL1 in unrelated-donor on transplant's day was 265.14 copies/10 000abl copies, the median expression of KIR2DL1 in recipient 1M, 2M, 3M, 3-6M, 6-9M, 9-12M after transplantat
Our aim was to better understand and improve the accuracy of the preoperative diagnosis of intraspinal MM by a combined analysis of MR imaging and pathologic findings. All 5 patients had undergone ...unenhanced and contrast-enhanced MR imaging examinations. All tumor samples had immunohistochemical reactions to HMB-45, vimentin, S-100, EMA, and Leu-7 antibodies. All 5 cases were located in the intradural extramedullary compartment. Two cases had multifocal lesions, and 3 cases were solitary. Two cases showed homogeneously strong enhancement, and 3 cases showed moderate enhancement on contrast-enhanced T1WI. The tumor cells had positive reactions to HMB-45, vimentin, and S-100 antibodies. MR imaging plays an important role in the detection and diagnosis of intraspinal MM. Final diagnosis should be based on histopathology and IHC examinations.
Background and purpose: The clinical use of arsenic trioxide (As2O3), a potent antineoplastic agent, is limited by its severe cardiotoxic effects. QT interval prolongation and apoptosis have been ...implicated in the cardiotoxicity of As2O3. The present study was designed to evaluate the effects of resveratrol on As2O3‐induced apoptosis and cardiac injury.
Experimental approach: In a mouse model of As2O3‐induced cardiomyopathy in vivo, QT intervals and plasma enzyme activities were measured; cardiac tissues were examined histologically and apoptosis assessed. In H9c2 cardiomyocyte cells, viability, apoptosis, generation of reactive oxygen species (ROS) and cellular calcium levels were measured.
Key results: In the mouse model, resveratrol reduced As2O3‐induced QT interval prolongation and cardiomyocyte injury (apoptosis, myofibrillar loss and vacuolization). In addition, increased lactate dehydrogenase activity and decreased activities of glutathione peroxidase, catalase and superoxide dismutase were observed in the plasma of As2O3‐treated mice; these changes were prevented by pretreatment with resveratrol. In As2O3‐treated H9c2 cardiomyocytes, resveratrol significantly increased cardiomyocyte viability and attenuated cell apoptosis as measured by acridine orange/ethidium bromide staining, TdT‐mediated dUTP nick end labelling assay and caspase‐3 activity. As2O3‐induced generation of ROS and intracellular calcium mobilization in H9c2 cells was also suppressed by pretreatment with resveratrol.
Conclusions and implications: Our results showed that resveratrol significantly attenuated As2O3‐induced QT prolongation, structural abnormalities and oxidative damage in the heart. In H9c2 cardiomyocytes, resveratrol also decreased apoptosis, production of ROS and intracellular calcium mobilization induced by treatment with As2O3. These observations suggested that resveratrol has the potential to protect against cardiotoxicity in As2O3‐exposed patients.
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In the past decade, garlic has become one of the most popular complementary therapies for blood pressure (BP) control used by hypertensive patients. Numerous clinical studies have ...focused on the BP-lowering effect of garlic, but results have been inconsistent. Overall, there is a dearth of information available to guide the clinical community on the efficacy of garlic in hypertensive patients.
To systematically review the medical literature to investigate the current evidence of garlic for the treatment of hypertension.
PubMed, the Cochrane Library and EMBASE were searched for appropriate articles from their respective inceptions until August 2014. Randomized, placebo-controlled trials comparing garlic vs. a placebo in patients with hypertension were considered. Papers were independently reviewed by two reviewers and were analyzed using Cochrane software Revman 5.2.
A total of seven randomized, placebo-controlled trials were identified. Compared with the placebo, this meta-analysis revealed a significant lowering effect of garlic on both systolic BP (WMD: −6.71 mmHg; 95% CI: −12.44 to −0.99; P = 0.02) and diastolic BP (WMD: −4.79 mmHg; 95% CI: −6.60 to −2.99; P < 0.00001). No serious adverse events were reported in any of the trials.
The present review suggests that garlic is an effective and safe approach for hypertension. However, more rigorously designed randomized controlled trials focusing on primary endpoints with long-term follow-up are still warranted before garlic can be recommended to treat hypertensive patients.
To better understand rapid enhancements of the seed populations (hundreds of keV electrons) in the heart of the Earth's outer radiation belt (L* ~ 3.5–5.0) during different geomagnetic activities, we ...investigate three enhancement events measured by Van Allen Probes in detail. Observations of the fluxes and the pitch angle distributions of energetic electrons are analyzed to determine rapid enhancements of the seed populations. Our study shows that three specified processes associated with substorm electron injections can lead to rapid enhancements of the seed populations, and the electron energy increases up to 342 keV. In the first process, substorm electron injections accompanied by the transient and intense substorm electric fields can directly lead to rapid enhancements of the seed populations in the heart of the outer radiation belt. In the second process, the substorm injected electrons are first trapped in the outer radiation belt and subsequently transported into L* < 4.5 by the convection electric field. In the third process, the lower energy electrons are first injected at L* ~ 5.3 and then undergo drift resonance with ultralow‐frequency waves. These accelerated electrons by ultralow‐frequency waves are further transported into L* < 4.5 due to the convection electric field. This process is consistent with the radial diffusion. Our results suggest that these specified processes are important for understanding the dynamics of the seed populations in the heart of the outer radiation belt.
Key Points
Three specified different processes can lead to rapid enhancements of the seed populations in the heart of the Earth's outer radiation belt
The resonant acceleration associated with ULF waves is important for enhancements of the seed populations in L* ~ 3.5–5.0
These specified processes are important for understanding the dynamics of the seed populations in L* ~ 3.5–5.0
•Nearly full dense WC-doped ZrB2–ZrSi2 composites were fabricated at 1550°C.•The doping of WC refined the grain size and led to an anisotropic grain growth.•Pull out of the elongated grains improved ...the fracture toughness.
WC-doped ZrB2–ZrSi2 ceramic composites were fabricated by hot pressing at temperatures ranging from 1450°C to 1550°C. The influence of ZrSi2 content on the mechanical properties of the composites was investigated by means of three point bending test and single edge notched-beam test, respectively. The microstructure and phase composition were characterized by scanning electron microscope (SEM) and X-ray diffraction (XRD) analysis. The results revealed that: (i) the highest relative density was 99.5% for the composite fabricated at 1550°C; (ii) the doping of WC refined the grain size and led to an anisotropic grain growth which was evidenced by the occurrence of elongated grains; (iii) the highest strength and fracture toughness were 585MPa and 6.87MPam1/2, respectively; (iv) the main toughening mechanism was considered as the pull out of elongated grains and the deflection of cracks.
The transmission synchronizer is an important variable speed synchronization mechanism of a vehicle. Since accurate and feasible working load data at the design stage of the synchronizer are lacking, ...the design loads are taken to be static rather than actual working ones, resulting in a high failure rate of the synchronizer in service, which seriously affects the reliability of the whole transmission. The virtual prototype model of a transmission synchronizer is presented. The working load-effected fatigue life of a synchronizer pin is calculated with MSC.Patran software. The failure mechanism of the synchronizer pin is analyzed to predict its fatigue life under complicated working conditions. It provides an important theoretical basis for the optimum design of synchronizer mechanism parameters and reliable transmission design, which is of great practical significance.
A lack of objective biomarkers is preventing the screening and diagnosis of COVID-19 combined with major depression disorder (COVID-19-MDD). The purpose of this study was to identify diagnostic ...biomarkers and gene regulatory mechanisms associated with autophagy; a crucial process significantly involved in the pathogenesis of COVID-19-MDD.
In this study, differentially expressed genes (DEGs) were screened using GSE98793 from the GEO2R analysis (GEO) database, and intersected with the COVID-19-related gene (CRGs) and autophagy-related genes (ARGs) to obtain common genes involved in. Then, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses of these common genes were performed. Subsequently, the transcription factor (TF)-gene regulatory network and comorbidity network were constructed. In addition, 10 drug candidates were screened using the DSigDB database. To identify diagnostic markers, we used LASSO regression.
In total, 13 common genes were screened, which were primarily enriched in lysosomes, endoplasmic reticulum membranes, and other endomembrane systems also associated with autophagy. Additionally, these genes were involved in neurological cell signaling and have a functional role in pathways related to vascular endothelial growth factor, tyrosine kinase, autophagy, inflammation, immunity, and carcinogenesis. Tumors and psychiatric disorders were the most highly linked diseases to COVID-19. Finally, ten drug candidates and eight diagnostic markers (STX17, NRG1, RRAGD, XPO1, HERC1, HSP90AB1, EPHB2, and S1PR3) were screened.
This is the first study to screen eight diagnostic markers and construct a gene regulatory network for COVID-19-MDD from the perspective of autophagy. The findings of our study provide novel insights into the diagnosis and treatment of COVID-19-MDD.
This study compared the effects of sodium selenite and selenium yeast and their combination on laying performance, egg quality, antioxidant capacity, and selenium (Se) contents in tissues and eggs. ...Two-hundred-eighty-eight Jing Hong layers that were similar in laying rate (87.5 ± 0.38%) and body weight (1.70 ± 0.02 kg) were randomly distributed into 4 treatments for 11 wk (from 203 d old to 279 d old) with 9 replicates of 8 hens per replicate. The diets (corn-soybean meal diet) were supplemented with 0 blank control (BC), 0.3 mg/kg Se from sodium selenite (SS), 0.15 mg/kg Se from sodium selenite and 0.15 mg/kg Se from Se yeast (SS+SY), or 0.3 mg/kg Se from Se yeast (SY). Results showed that the laying rate of the SS+SY group increased significantly (P < 0.05) compared to the BC and SY groups. There were no differences (P > 0.05) in egg quality between the Se-supplemented diets and the BC diet. The serum glutathione peroxidase (GSH-Px) activity was increased (P < 0.01) in hens fed Se-supplemented diets compared to the BC diet. The liver superoxide dismutase (SOD) activity of the SY group was increased significantly (P < 0.05) compared to the BC group. Significant increase (P < 0.01) due to SY supplementation was noted in the serum vitamin E content compared to BC and SS. Layers fed Se-supplemented diets had higher (P < 0.01) contents of Se in the serum, liver, and kidney compared to the BC diet. Compared to BC, Se content in eggs was significantly increased (P < 0.05) by feeding supplementary Se. In conclusion, the effects of SS and Se yeast were approximately equal in promoting antioxidant capacity of laying hens, while Se yeast is easier to deposit into eggs and tissues. The diet with added equal amounts of the 2 sources of Se was more cost effective and affordable than a comparable amount of Se yeast to obtain the promising production performance and nearly similar Se deposition.
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