Simultaneous Enhancement of Strength and Sulfide Stress Cracking Resistance of Hot-Rolled Pressure Vessel Steel Q345 via a Quenching and Tempering Treatment.

Sulfide stress cracking (SSC) failure is a main concern for the pressure vessel steel Q345 used in harsh sour oil and gas environments containing hydrogen sulfide (H2S). Methods used to improve the strength of steel usually decrease their SSC resistance. In this work, a quenching and tempering (Q&T) processing method is proposed to provide higher strength combined with better SSC resistance for hot-rolled Q345 pressure vessel steel. Compared to the initial hot-rolled plates having a yield strength (YS) of ~372 MPa, the Q&T counterparts had a YS of ~463 MPa, achieving a remarkable improvement in the strength level. Meanwhile, there was a resulting SSC failure in the initial hot-rolled plates, which was not present in the Q&T counterparts. The SSC failure was not only determined by the strength. The carbon-rich zone, residual stress, and sensitive hardness in the banded structure largely determined the susceptibility to SSC failure. The mechanism of the property amelioration might be ascribed to microstructural modification by the Q&T processing. This work provides an approach to develop improved strength grades of SSC-resistant pressure vessel steels.

Biodegradation, Antibacterial Performance, and Cytocompatibility of a Novel ZK30-Cu-Mn Biomedical Alloy Produced by Selective Laser Melting.

In the present study, an antibacterial biomedical magnesium (Mg) alloy with a low biodegradation rate was designed, and ZK30-0.2Cu-xMn (x = 0, 0.4, 0.8, 1.2, and 1.6 wt%) was produced by selective laser melting, which is a widely applied laser powder bed fusion additive manufacturing technology. Alloying with Mn evidently influenced the grain size, hardness, and biodegradation behavior. On the other hand, increasing Mn content to 0.8 wt% resulted in a decrease of biodegradation rate which is attributed to the decreased grain size and relatively protective surface layer of manganese oxide. Higher Mn contents increased the biodegradation rate attributed to the presence of the Mn-rich particles. Taken together, ZK30-0.2Cu-0.8Mn exhibited the lowest biodegradation rate, strong antibacterial performance, and good cytocompatibility.

Facile synthesis of O-acylhydroxamates via reaction of oxime chlorides with carboxylic acids.

A simple and efficient method for the synthesis of O-acylhydroxamate derivatives from oxime chlorides and carboxylic acids was developed. The reaction affords clean and facile access to diverse O-acylhydroxamates in high yields (up to 85%). The chemical structure of a typical product was confirmed using single-crystal X-ray structure analysis.

Correlations Between Radiation Dose in Bone Marrow and Hematological Toxicity in Patients With Cervical Cancer: A Comparison of 3DCRT, IMRT, and RapidARC.

OBJECTIVE: To comparatively evaluate the hematological toxicity (HT) associated with 3 concurrent chemoradiotherapies that are routinely used to treat cervical cancer, including 3-dimensional conformal radiotherapy (3DCRT), intensity-modulated radiation therapy (IMRT), and RapidARC and to establish a new normal tissue complication probability model of bone marrow (BM) to predict HT in cervical cancer patients undergoing concurrent chemoradiotherapy. METHODS: Patients with cervical cancer (N = 100) who received concurrent cisplatin and whole-pelvic radiotherapy were enrolled in this study. Dosimetric parameters (including V10, V20, V30, and V40 and mean doses to the pelvic bone) and HT were analyzed. RESULTS: The V20, V30, and V40 and mean doses to the BM were lower in the IMRT and RapidARC groups than in the 3DCRT group, and the RapidARC group had higher V10 and V40 and mean values than the IMRT group. The V20, V30, and V40 and the mean dose to the pelvic bone were positively correlated with HT. Generalized linear normal tissue complication probability models of white blood cell (WBC) and absolute neutrophil cell (ANC) nadirs and BM V20 were established as follows: WBC nadir = 3.382 - 4.056 • V20 + 0.295 • baseline of WBC (adjusted R = 0.246, F = 15.847) and ANC nadir = 2.438 - 2.780 • V20 + 0.233 • baseline of ANC (adjusted R = 0.236, F = 16.282). CONCLUSIONS: This study suggests that IMRT results in milder hematological toxicity than either 3DCRT or RapidARC. Dosimetric parameters were associated with the incidence of HT in cervical cancer patients who received concurrent chemoradiotherapies.

MEF2D/Wnt/ß-catenin pathway regulates the proliferation of gastric cancer cells and is regulated by microRNA-19.

The underlying molecular pathogenesis in gastric cancer remains poorly unknown. The transcription factor myocyte enhancer factor 2D (MEF2D) participates in the initiation and development of many human cancers. However, its potential roles in gastric cancer have surprisingly not been studied. In present study, we first explored MEF2's expression in gastric cancer, finding that only MEF2D rather than MEF2A, 2B, or 2C was elevated in gastric cancer clinical specimens. Furthermore, immunohistochemical analysis on the tissue samples obtained from 260 patients with gastric cancer revealed that MEF2D expression was significantly associated with the clinical stage, vascular invasion, metastasis, and tumor size. Gastric cancer patients with MEF2D expression showed a significantly shorter overall survival time compared with that of patients lacking of MEF2D. Multivariate analysis revealed that MEF2D expression was an independent prognostic factor for overall survival. These results indicated that MEF2D was a prognostic marker for gastric cancer. Notably, MEF2D silencing was able to reduce the proliferation and survival of gastric cancer cells. Further study revealed that MEF2D suppression significantly inactivated the oncogenic Wnt/ß-catenin pathway. Downregulation of MEF2D inhibited the tumorigenesis of gastric cancer cells in nude mice. Finally, MEF2D is a direct target of miR-19, which was found to be decreased in gastric cancer clinical specimens. Collectively, we found that miR-19/MEF2D/Wnt/ß-catenin regulatory network contributes to the growth of gastric cancer, hinting a new promising target for gastric cancer treatment.