Stress corrosion cracking behavior of 310S in supercritical water with different oxygen concentrations

The effect of dissolved oxygen(DO) on the stress corrosion cracking(SCC) of 310 S in supercritical water was investigated using slow-strain-rate tensile tests.The tensile properties, fracture morphology, and distribution of the chemical composition of the oxide were analyzed to evaluate the SCC susceptibility of 310 S. The results showed that the rupture elongation decreased significantly as the degree of DO increased. A brittle fracture mode was observed on the fracture surface, and only intergranular cracking was observed on the surface of the gauge section, regardless of the DO. Cracks were widely distributed on the gauge surface near the fracture surface.Oxides were observed in the cracks with two-layered structures, i.e., a Cr-rich inner oxide layer and an Fe-rich outer oxide layer.

Comparison of the performance of MS enteroscope series and Japanese double-and single-balloon enteroscopes

BACKGROUND Small intestine disease endangers human health and is not easy to locate and diagnose.AIM To observe the effect of the MS series of small intestine endoscopes on the gastrointestinal tract,the changes in serum gastrin levels and intestinal tissue,and the time required for the examination.METHODS In vivo experiments in 20 Living pigs were conducted,Bowel preparation was routinely performed,Intravenous anesthesia with propofol and ketamine was applied,the condition of the small intestine was observed and the detection time of the MS series of small intestine endoscopes were recorded,The changes in intestinal tissue using the MS series of small intestine endoscopes observed and compared before and after the examination,Venous blood(3-5 mL)from pigs was collected before and after the experiment;changes in intestinal tissue after use of the MS series of small intestine endoscopes observed after examination.After completion of each type of small intestine endoscope experiment,the pigs were allowed to rest and the next type of small intestine endoscope experiment was performed after 15 days of normal feeding.The detection time data of the single-balloon small intestine endoscope and doubleballoon small intestine endoscope were collected from four hospitals.RESULTS One case of Ascarislumbricoides,one of suspected Crohn’s disease,one small intestinal diverticulum and one anesthesia accident were observed in pigs.The small intestine showed no differences in the MS series of small intestine endoscopes and there were no differences in serum gastrin between the groups(P>0.05).The time required for inspection was recorded,and the overall detection time for the Japanese small intestine endoscopes was approximately 1.68±0.16 h.CONCLUSION Intestinal ascariasis is a common disease in pigs.Some pigs have abnormal intestinal variation.After continuous upgrade and improvement,the MS-3 and MS-4 small intestine endoscope appear superior in terms of detection time.

Animal experimental studies using small intestine endoscope

AIM To assess the feasibility and safety of a novel enteroscope,negative-pressure suction endoscope in examining the small intestine of a porcine model.METHODS In vitro experiments in small intestinal loops from 20pigs and in vivo experiments in 20 living pigs were conducted.RESULTS In in vitro experiments,a negative pressure of>0.06MPa was necessary for optimal visualization of the intestine,and this pressure did not cause gross or histological damage to the mucosa.For satisfactory examination of the small intestine in vivo,higher negative pressure(>1.00 MPa)was required.Despite this higher pressure,the small intestine did not show any gross or microscopic damage in the suctioned areas.The average time of examination in the living animals was 60±7.67 min.The animals did not experience any apparent ill effects from the procedure.CONCLUSION Small intestine endoscope was safely performed within a reasonable time period and enabled complete visualization of the intestine in most cases.

Human Papillomavirus Type 16 Mutant E7 Protein Induces Oncogenic Transformation via Up-regulation of Cyclin A and cdc25A

A new mutant human papillomavirus type 16 E7 gene, termed HPV16 HBE7, was isolated from cervical carcinoma biopsy samples from patients in an area with high incidence of cervical cancer (Hubei province, China). A previous study showed that the HPV16 HBE7 protein was primarily cytoplasmic while wild-type HPV16 E7 protein, termed HPV16 WE7, was concentrated in the nucleus. With the aim of studying the biological functions of HPV16 HBE7, the transforming potential of HPV16 HBE7 in NIH/3T3 cells was detected through observation of cell morphology, cell proliferation assay and anchorage-independent growth assay. The effect of HPV16 HBE7 on cell cycle was examined by flow cytometry. Dual-luciferase reporter assay and RT-PCR were used to investigate the influence of HPV16 HBE7 protein on the expression of regulation factors associated with G1/S checkpoint. The results showed that HPV16 HBE7 protein, as well as HPV16 WE7 protein, held transformation activity. NIH/3T3 cells expressing HPV16 HBE7 could easily transition from G1 phase into S phase and expressed high level of cyclin A and cdc25A. These results indicated HPV16 mutant E7 protein, located in the cytoplasm, induces oncogenic transformation of NIH/3T3 cells via up-regulation of cyclin A and cdc25A.

A rare porous zinc phosphonocarboxylate framework with high thermal stability and interesting structural transformation

A rare porous zinc-organic framework with ultrahigh thermal stability over 500℃ was obtained, which exhibits a CaF2-type topology formed by 8-connected tetranuclear Zn4 clusters and 4-connected phosphonocarboxylate ligands. Interestingly, the similar reactions to the 2 zinc-organic framework but in the absence of H2 O or by the replacement of Zn2＋with Co2＋can yield three different 3 D cluster-based frameworks but with the same CaF2-type topology.