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The flow field in the tip region of an axial ventilation fan was investigated with a PIV (Particle Image Velocimeter) system at the design condition. Characteristics of a ventilation fan are an extreme low-pressure difference and a large tip clearance with a low rotating speed. Flow fields with three different tip clearances are surveyed on three different circumferential planes, respectively. The phase-locked average method is used to investigate the generation and the development of a tip leakage vortex. The result from PIV system was compared with that from a PDA (Particle Dynamics Anemometer) system. Both data are in good agreement. The structure of the tip leakage vortexfor the rotor was illustrated. The characteristic of a leakage vortex was described in both velocity vectors and vortical contours. It is found that the tip leakage flow for low speed and a low pressure ventilation fan also has a chance to roll up into a discrete vortex at three different tip clearances, which is similar to high speed and high-pressure compressors and turbines. When the tip clearance increases, the scope and the location variation for the tip leakage vortex increases. Finally, the trajectory of the tip leakage vortex by the experimental measurement is compared with predictions from the existing models for high speed and high-pressure compressors and turbines. A good agreement is obtained. [ABSTRACT FROM AUTHOR]

Due to the tip clearance, the three-dimensional flow in the tip region of rotor is more complicated. It is very difficult to acquire the detailed flow in the passage of rotor, owing to the relative rotation between the rotor and the casing wall. The commercial software CFX-Tascflow is employed to compute the three-dimensional viscous flow in an axial flow rotor with tip clearance. Based on the comparison of the measured and computed performance curve, the tip leakage flow in the tip region was investigated. The tip leakage has a chance to rollup a discrete tip leakage vortex. The work in this paper helps to improve the turbomachinery design. [ABSTRACT FROM AUTHOR]

Glycogen storage disease type V is an autosomal recessive genetic disorder caused by muscle glycogen phosphorylase (PYGM) deficiency, which is characterized by exercise intolerance, second wind phenomena and high level of serum creatine kinase. In this study, we reported a Chinese young man with glycogen storage disease type V, with lower extremity weakness after exercise, increased creatine kinase, and slight fat infiltration in the posterior group of thigh muscle by magnetic resonance imaging (MRI). The proband had complex heterozygous PYGM disease-causing mutations, including c.308T>C (p.L103P) variant transmitted from the mother and c.260_261delCT (p.S87Ffs*23) from the father, of which the former was a novel PYGM mutation. This study enriched the PYGM pathogenic gene mutation spectrum, contributed to improve clinicians' understanding of glycogen storage disease type V and provided a reference for further genetic study of the disease.

Lin28 plays important roles in the development, maintenance of pluripotency and progression of various types of cancers. Lin28 represses the biogenesis of let-7 microRNAs and is implicated in both development and tumorigenesis. Oncogenic regulation of let-7 microRNAs has been demonstrated in several human malignancies, yet their correlation with Lin28 has not yet been studied in gastric cancer. Therefore, in the present study, we explored the possible mechanisms involved in the effects by Lin28 on the proliferation, migration, cell cycle arrest and apoptosis in gastric cancer cells via alteration of let-7 miRNA. The expression levels of Lin28 and let-7 were detected by real-time PCR in gastric cancer cell lines in vitro. Lin28 was overexpressed in the BGC-823 cells via lentiviral transfection, and let-7 expression was assessed. Cell proliferation and migration capabilities were investigated by MTT and Transwell assays, while cell cycle distribution and the apoptosis rate were detected using flow cytometry. The expression of Lin28 was moderately expressed in the GES cells while underexpressed in the BGC-823, SGC-7901 and HGC-27 cells. Let-7a miRNA was highly expressed in the GES, BGC-823, SGC-7901 and HGC-27 cells. Overexpression of Lin28 was inversely correlated with the downregulated expression of let-7a, and markedly suppressed the proliferation, migration, cell cycle progression and induced apoptosis in the BGC-823 cells. These findings demonstrated that overexpression of Lin28 can suppress the biological behavior of gastric cancer in vitro, and let-7 miRNA may play an important role in the process. We suggest that Lin28 may be a candidate predictor or an anticancer therapeutic target for gastric cancer patients.

Lysyl oxidase (LOX) initiates the enzymatic stage of collagen and elastin cross-linking. It also has intracellular functions involved in the regulation of cell differentiation, motility/migration and gene transcription. Aberrant expression of the LOX gene has been reported in multiple tumors. However, the correlation of its expression with clinicopathological parameters and its prognostic significance in gastric cancer remains largely unknown. In order to address this problem, total RNA of paired tissue samples (n=10) and a tissue microarray containing 161 paired tissues from patients with gastric cancers at different stages were collected. Quantitative real-time PCR and immunochemistry assay were conducted to investigate the expression of LOX. Based on the results, LOX mRNA was increased in gastric cancer tissues compared with the adjacent normal mucosa. Immunohistochemical detection revealed that expression of LOX was associated with depth of tumor invasion (P<0.05), lymph node status (P<0.05), TNM stage (P<0.05) and survival (P<0.05). Cox regression analysis revealed that positive expression of LOX (P=0.026) was an independent prognostic marker for survival in patients with gastric cancer.