A Study of Hydrogen Embrittlement of SA-372 J Class High Pressure Hydrogen Storage Seamless Cylinder (≥100 MPA).

The spinning process will lead to changes in the micro-structure and mechanical properties of the materials in different positions of the high-pressure hydrogen storage cylinder, which will show different hydrogen embrittlement resistance in the high-pressure hydrogen environment. In order to fully study the safety of hydrogen storage in large-volume seamless steel cylinders, this chapter associates the influence of the forming process with the deterioration of a high-pressure hydrogen cylinder (≥100 MPa). The anti-hydrogen embrittlement of SA-372 grade J steel at different locations of the formed cylinders was studied experimentally in three cylinders. The hydrogen embrittlement experiments were carried out according to method A of ISO 11114-4:2005. The relationship between tensile strength, microstructure, and hydrogen embrittlement is analyzed, which provides comprehensive and reliable data for the safety of hydrogen storage and transmission.

Two novel predictive biomarkers for osteosarcoma and glycolysis pathways: A profiling study on HS2ST1 and SDC3.

INTRODUCTION: Prognostic biomarkers for osteosarcoma (OS) are still very few, and this study aims to examine 2 novel prognostic biomarkers for OS through combined bioinformatics and experimental approach. MATERIALS AND METHODS: Expression profile data of OS and paraneoplastic tissues were downloaded from several online databases, and prognostic genes were screened by differential expression analysis, Univariate Cox analysis, least absolute shrinkage and selection operator regression analysis, and multivariate Cox regression analysis to construct prognostic models. The accuracy of the model was validated using principal component analysis, constructing calibration plots, and column line plots. We also analyzed the relationship between genes and drug sensitivity. Gene expression profiles were analyzed by immunocytotyping. Also, protein expressions of the constructed biomarkers in OS and paraneoplastic tissues were verified by immunohistochemistry. RESULTS: Heparan sulfate 2-O-sulfotransferase 1 (HS2ST1) and Syndecan 3 (SDC3, met all our requirements after screening. The constructed prognostic model indicated that patients in the high-risk group had a much lower patient survival rate than in the low-risk group. Moreover, these genes were closely related to immune cells (P < .05). Drug sensitivity analysis showed that the 2 genes modeled were strongly correlated with multiple drugs. Immunohistochemical analysis showed significantly higher protein expression of both genes in OS than in paraneoplastic tissues. CONCLUSIONS: HS2ST1 and SDC3 are significantly dysregulated in OS, and the prognostic models constructed based on these 2 genes have much lower survival rates in the high-risk group than in the low-risk group. HS2ST1 and SDC3 can be used as glycolytic and immune-related prognostic biomarkers in OS.

Elastic-Plastic Numerical Analysis of the Spinning Process of SA-372 Steel Used in High-Pressure Hydrogen Storage Cylinders (≥100 MPA).

Elastic-plastic numerical analysis of the spinning process of SA-372 steel is used in high-pressure hydrogen storage to analyze high-pressure hydrogen storage cylinders with high precision and excellent hydrogen embrittlement resistance. The spinning process of SA-372 steel used to form such a cylinder with a pressure of 100 MPa is investigated through elastic-plastic finite element analysis. The variations in the stress, strain, pressure, temperature, and wall thickness during the spinning processes are comprehensively examined, and the optimized processing parameters are determined based on the numerical analysis results. Finally, these optimal parameters are used to conduct actual spin-forming experiments. The numerical results are found to be in excellent agreement with the experimental results, which verifies the feasibility and effectiveness of the proposed elastic-plastic numerical analysis model for the optimization of spinning process parameters. Furthermore, the hydrogen embrittlement test based on ISO 11114-4:2005 method A proves that the cylinder shoulder has a good hydrogen embrittlement resistance.

Synthesis of polyketide stereoarrays enabled by a traceless oxonia-Cope rearrangement.

Polyketide antibiotics bearing skipped polyols represent a synthetic challenge. A SiCl4-promoted oxonia-Cope rearrangement of syn,syn-2-vinyl-1,3-diols was developed to forge an array of 1,5-pentenediols, thus providing versatile motifs for the preparation of 1,2,3,5-stereoarrays in a highly stereoselective manner. Further exploration with Sn(OTf)2 realized the rearrangement of a cross-aldehyde which tactically warrants the utility of the current approach to access complex polyketides. The origin of high stereoselectivity is attributed to a chairlike anti-conformation of the oxonium ion intermediate.

Study on the coupling of acyclic esters with alkenes--the synthesis of 2-(2-hydroxyalkyl)cyclopropanols via cascade cyclization using allylsamarium bromide.

The radical cyclization between aliphatic acyclic esters and alkenes was achieved unprecedentedly in the presence of allylsamarium bromide with HMPA and H(2)O as additives. The cascade radical cyclization-ring-opening-anionic cyclization allowed facile and efficient access to 2-(2-hydroxyalkyl)cyclopropanols from readily available materials.

(E)-5-Benzyl-1-methyl-N-nitro-1,3,5-triazinan-2-imine.

In the title compound, C(11)H(15)N(5)O(2), the 1,3,5-triazine ring exhibits a half-chair conformation. An intra-molecular N-H⋯O inter-action occurs. In the crystal structure, mol-ecules are connected by inter-molecular C-H⋯O and N-H⋯N hydrogen bonds, forming a zigzag chain along the b axis.

[The clinical application of the neurovascular island flap of the calf supported by perforating branches of peroneal artery].

OBJECTIVE: To study the clinical application of the neurovascular island flap of the calf supported by perforating branches of peroneal artery for the soft tissue defects of ankle and the foot. METHODS: The flaps were used in 27 cases to repair the soft tissue defects of ankle and the lower leg from February 2004 to December 2007. Among them, 21 cases were male and 6 cases were female, ranging in age from 7 months to 64 years, with an average of 31.5 years. There were 7 cases with external malleolus, 5 cases with medial malleolus, 8 cases with dorsum of foot, 7 cases with achilles tendon. The range of soft tissue defects was from 2.5 cm x 3.5 cm to 10 cm x 24 cm and the range of flap was from 3 cm x 4 cm to 12 cm x 26.5 cm. RESULTS: Seven cases were lightly swelling and distension after operation from 3 to 7 days. After 7 days, the swelling subsidised gradually and all flaps survived. In the follow-up for 3-12 months with an average of 5 months, all flaps showed fine appearance without fat and clumsy. The function of donor site was very well. CONCLUSION: The neurovascular island flap of the calf supported by perforating branches of peroneal artery can provide reliable blood supply, long reversed distance and wide repairing limitation and the proximal end of flap can reach to popliteal fossa. It is a good method to repair the defects of the lower leg and the foot.