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  • Author: Zhang Ji-wang x
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Abstract

High-speed blades form core mechanical components in turbomachines. Research concerning online monitoring of operating states of such blades has drawn increased attention in recent years. To this end, various methods have been devised, of which, the blade tip-timing (BTT) technique is considered the most promising. However, the traditional BTT method is only suitable for constant-speed operations. But in practice, the rotational speed of turbomachine blades is constantly changing under the influence of external factors, which lead to unacceptable errors in measurement. To tackle this problem, a new BTT method based on multi-phases is proposed. A plurality of phases was arranged as evenly as possible on the rotating shaft to determine the rotation speed. Meanwhile, the corresponding virtual reference point was determined in accordance with the number of blades between consecutive phases. Based on these reference points, equations to measure displacement due to blade vibrations were deduced. Finally, mathematical modeling, numerical simulation and experimental tests were performed to verify the validity of the proposed method. Results demonstrate that the error in measurement induced when using the proposed method is less than 1.8 %, which is much lower compared to traditional methods utilized under variable-speed operation.

Abstract

Introduction

Enolases are enzymes in the glycolytic pathway, which catalyse the reversible conversion of D-2-phosphoglycerate into phosphoenol pyruvate in the second half of the pathway. In this research, the effects of α-enolase (ENO1) on steroid reproductive-related hormone receptor expression and on hormone synthesis of primary granulosa cells from goose F1 follicles were studied.

Material and Methods

Primary granulosa cells from the F1 follicles of eight healthy 8-month-old Zi geese were separated and cultured. An ENO1 interference expression vector was designed, constructed and transfected into primary cultured granulosa cells. The mRNA expression levels of follicle-stimulating hormone receptor (FSHR), luteinising hormone receptor (LHR), oestrogen receptor α (ER α), oestrogen receptor β (ER β), growth hormone receptor (GHR) and insulin-like growth factor binding protein-1 (IGFBP-1) in the cells were evaluated as were the secretion levels of oestradiol, activin, progesterone, testosterone, inhibin and follistatin in cell supernatant.

Results

α-enolase gene silencing reduced the expression of FSHR, LHR, ERα, ERβ, GHR, and IGFBP-1 mRNA, potentiated the secretion of oestrogen, progesterone, testosterone, and follistatin of granulosa cells, and hampered the production of activin and inhibin.

Conclusion

ENO1 can regulate the reactivity of granulosa cells to reproductive hormones and regulate cell growth and development by adjusting their hormone secretion and reproductive hormone receptor expression. The study provided a better understanding of the functional action of ENO1 in the processes of goose ovary development and egg laying.

Abstract

The objective of this study was to investigate the effect of reduced levels of Cu, Zn, Mn in combination from organic mineral source on eggshell quality and mineral retention in hens. After feeding the basal diet (8.82 mg/kg Cu, 24.94 mg/kg Zn, and 16.38 mg/kg Mn) without Cu, Zn, and Mn addition for 4 weeks, hens (39-week-old) were assigned to 5 treatments according to the equal body weight and egg production for 12-week experimental trial. The 5 treatments included the basal diet without Cu, Zn, and Mn (NCON), and NCON added with 16-80-60 mg/kg Cu-Zn-Mn from sulfates (ITM100%), or 4-20-15, 8-40-30 or 16-80-60 mg/kg Cu-Zn-Mn from 2-hydroxy-4-(methylthio)butanoic acid (HMTBA) mineral chelates (OTM25%, OTM50% or OTM100%). Supplementation of Cu, Zn, and Mn had no significant influences on the performance of hens. After 12 weeks feeding, eggshell breaking strength (EBS) decreased in the following order: OTM25% and ITM100% > OTM50% > NCON and OTM100%. The eggshell weight and thickness in OTM25% were greater than that in NCON, while not differing from that in ITM100%. The EBS and eggshell weight linearly decreased with increasing level of OTM. After 12 weeks feeding, supplementation of Cu, Zn, and Mn increased the concentrations of liver Zn, tibia Zn and Mn, and Zn and Mn retention in eggs as compared with NCON. No significant difference was observed in the concentrations of Cu, Zn, and Mn in liver and plasma, and Zn and Mn in eggs between any OTM treatment and ITM100% groups. Addition of OTM at increasing level had quadratic effect on tibia Cu, Zn, Mn concentrations, with the greater retention of Cu, Zn, and Mn in OTM50%. In conclusion, the OTM25% from HMT BA mineral chelates can substitute for ITM100% evaluated by the eggshell quality in the diet of laying hens.

Abstract

Objective Genome-wide association studies (GWAS) have linked many single nucleotide polymorphisms (SNPs) to the outcomes of a variety of liver diseases. The aim of the present study was to evaluate the association of several candidate SNPs with the risk and severity of cirrhosis due to chronic hepatitis B in a Chinese population.

Methods A total of 714 Chinese participants with persistent HBV infection were studied. Patients were divided into cirrhotic (n = 429) and non-cirrhotic (n = 285) groups based on clinical and pathological evidence. The progression rate and severity of liver cirrhosis were evaluated with an arbitrary t-score system. Genotypes of six SNPs in five candidate genes were detected with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The genotypic distributions of the SNPs were compared between the age-matched cirrhotic and non-cirrhotic subjects. The association between the risk of SNPs and the severity and progression rate of cirrhosis was further analyzed.

Results Rs2679757 polymorphism of the antizyme inhibitor 1 (AZIN1) gene and Rs886277 in the transient receptor potential cation channel subfamily M, member 5 gene (TRPM5) were found to be associated with cirrhosis risk in CHB. They were also correlated with the overall severity and progression rate of cirrhosis. Genotype frequencies of other SNPs were not different between the cirrhosis and non-cirrhosis groups.

Conclusions AZIN1 rs2679757 and TRPM5 rs886277 are associated with the risk and the progression rate of HBV-related liver fibrosis in Chinese patients. The emerging SNPs associated with cirrhosis prognosis warrant further clinical validation in other CHB cohorts or ethnic groups, and merit mechanistic studies to reveal their roles in fibrosis progression.

Abstract

Introduction: The extremely high genetic variation and the continuously emerging variants of foot-and-mouth disease virus (FMDV) of Southern African Territory (SAT) serotypes including SAT1, SAT2, and SAT3 make it necessary to develop a new RT-PCR for general use for monitoring viruses based on the updated genome information.

Material and Methods: A FMDV SAT-D8 one-step RT-PCR was established based on the 1D2A2B genes of the SAT serotype viruses with a multiplex primer set. FMDV A, O, C, and Asia 1 serotypes, other vesicular disease viruses, inactivated SAT viruses, and 125 bovine, ovine, caprine and porcine tissue samples collected from the Chinese mainland were included for evaluating the assay.

Results: The new RT-PCR was proven to be specific without cross-reactions with Eurasian FMDV, swine vesicular disease virus (SVDV), Seneca valley virus (SVV), or other common viral pathogens of cattle, sheep, goat, and pig. An around 257 bp-sized amplicon clearly appeared when the inactivated SAT viruses were detected. However, all 125 samples collected from FMDV-susceptible animals from the Chinese mainland which has not known SAT epidemics showed negative results.

Conclusions: A FMDV SAT-D8 one-step RT-PCR is a promising method for primary screening for FMDV SAT serotypes.

Abstract

Objective: The objective was to increase the understanding of vascular access in hemodialysis and evaluate hemodialysis-related anticoagulation treatments and the associated hemorrhagic or thrombotic complications. Materials and Methods: In this study, an epidemiological investigation was conducted in 1175 patients who underwent hemodialysis in seven blood purification centers in northern Chinese. The patients were divided into two groups based on the vascular access they used: Arteriovenous fistula (AVF) group and central venous catheter (CVC) group. The similarities and differences of anticoagulation and hemorrhagic, thrombotic complications were compared between two groups. Results: Arteriovenous fistula was the most frequently used vascular access, and heparin was the most commonly used anticoagulant. Patients in CVC group experienced significantly greater rates of low molecular weight heparin (LMWH) administration and had a higher rate in achieving thrombotic complications than those in AVF group. There were no significant differences in LMWH dosages in patients with thrombotic complications, as well as the proportion of patients who received anti-platelet drugs. Heparinized catheter lock solutions were excessively high in this study, which may lead to a risk of hemorrhage. Conclusion: Hemodialysis-related anticoagulation treatments in China require additional improvements, especially for the patients using CVC as vascular access. There is an urgent need to develop clinical evaluation studies of anticoagulation treatments for achieving more standardized and targeted treatments.