Microstructure Evolution and Mechanical Response of a Direct Quenched and Partitioned Steel at Different Finishing Rolling Temperatures.

The effects of finishing rolling temperature on the microstructure and mechanical properties of a direct quenched and partitioned (DQ&P) steel were investigated by a thermal simulation machine, a field emission scanning electron microscope (FE-SEM), electron backscattering diffraction (EBSD), and a transmission electron microscope (TEM). The results show that the original austenite grain size was refined by 31% as the finishing rolling temperature decreased from 920 °C to 840 °C, leading to the formation of the finest martensite lath at 840 °C. At the same time, the lower finishing rolling temperature resulted in a higher dislocation density, and consequently improved the stability of the retained austenite. Moreover, compared to the conventional Q&P process, the comprehensive mechanical properties of a steel with similar chemical composition can be enhanced by DQ&P processing. With the decrease of finishing rolling temperature from 920 °C to 840 °C, the strength and total elongation increases. The yield strength, tensile strength, and total elongation reach the maximum values of 1121 MPa, 1134 MPa, and 11.7%, respectively, at 840 °C.

Comprehensive transcriptomic analysis of immune-related eRNAs associated with prognosis and immune microenvironment in melanoma.

Background: Recent evidence suggests that enhancer RNAs (eRNAs) play key roles in cancers. Identification of immune-related eRNAs (ireRNAs) in melanoma can provide novel insights into the mechanisms underlying its genesis and progression, along with potential therapeutic targets. Aim: To establish an ireRNA-related prognostic signature for melanoma and identify potential drug candidates. Methods: The ireRNAs associated with the overall survival (OS-ireRNAs) of melanoma patients were screened using data from The Cancer Genome Atlas (TCGA) via WGCNA and univariate Cox analysis. A prognostic signature based on these OS-ireRNAs was then constructed by performing the least absolute shrinkage and selection operator (LASSO) Cox regression analysis. The immune landscape associated with the prognostic model was evaluated by the ESTIMATE algorithm and CIBERSORT method. Finally, the potential drug candidates for melanoma were screened through the cMap database. Results: A total of 24 OS-ireRNAs were obtained, of which 7 ireRNAs were used to construct a prognostic signature. The ireRNAs-related signature performed well in predicting the overall survival (OS) of melanoma patients. The risk score of the established signature was further verified as an independent risk factor, and was associated with the unique tumor microenvironment in melanoma. We also identified several potential anti-cancer drugs for melanoma, of which corticosterone ranked first. Conclusions: The ireRNA-related signature is an effective prognostic predictor and provides reliable information to better understand the mechanism of ireRNAs in the progression of melanoma.

[Expression of α(5) subunit of extrasynaptic GABA(A) receptor in insular-kindled rats].

OBJECTIVE: To explore the expression of α(5) subunit of extrasynaptic GABA(A) receptor in insular electrical kindled rats and analyze its significance. METHODS: A total of 96 male Sprague-Dawley rats were divided randomly into kindled, sham-operated and control groups (n = 32). And each group was further divided into 2 sub-groups at different time points. Kindled group: insular electrical kindled via chronic electrical stimulation; Sham-operated group: electrode implantation without electrical stimulation; CONTROL GROUP: no operation at all. The number of hippocampal neurons was detected by Nissl staining; the mRNA of α(5) subunit of hippocampus by quantitative-polymerase chain reaction (q-PCR); the expression of α(5) subunit of hippocampus by immunohistochemistry. RESULTS: No significant difference existed in the number of hippocampal neurons between epileptic and normal rats (P > 0.05). The mRNA levels of α(5) subunit of hippocampus in the sham-operated and control groups were much higher than that of the kindled group at Day 1 and 7 post-sacrificing (P < 0.01). And the hippocampal expressions of α(5) subunit were much more in the sham-operated and control groups than that of the kindled group at Day 1 and 7 post-sacrificing (P < 0.01). CONCLUSION: The hippocampal expression of α(5) subunit decreases markedly in insular epilepsy. And α(5) subunit may play an important role in the occurrence and development of insular epilepsy.

[Expression of neuropeptides ghrelin and Nesfatin-1 in kainic acid kindling rats].

OBJECTIVE: To observed the post-seizure expression level of neuropeptides ghrelin and Nesfatin-1 between the untreated and treated groups in kainic acid-kindling rats and understand the significance of their basic expressions. METHODS: The male S-D rats were divided randomly into NS and VPA groups after seizure. Each group was divided into 7 subgroups of 3 h, 6 h, 12 h, 24 h, 3 d, 7 d and 14 d. And the blank group (without NS or VPA) and sham group (normal saline instead of kainic acid) were established. RIA (radioimmunoassay), ELISA (enzyme-linked immunosorbent assay) and immunohistochemistry were used to detect the expression levels of ghrelin and Nesfatin-1 in the serum and hypothalamus of kainic acid-kindling rats. RESULTS: Compared with the blank and sham groups, the seizure rats had a decreased expression of ghrelin while there was an elevated expression of Nesfatin-1 in hypothalamus. This trend was consistent with the serum expressions of deacylated ghrelin and Nesfatin-1. The expression of ghrelin became elevated at all stages in the VPA group. Especially the subgroups of 24 h (0.320 ± 0.007) and 7 d (0.284 ± 0.004) had a significant increase (P < 0.05) while their expression levels remained lowed than that of the blank group (0.342 ± 0.039). The expressions of Nesfatin-1 had a significant decrease (P < 0.05) in all VPA subgroups while they were higher than those in the blank group (0.124 ± 0.007). CONCLUSION: An accurate detection of serum expression level of deacylated ghrelin and Nesfatin-1 may reflect the fluctuation trend of neuropeptides in hypothalamus. It may offer a simple, sensitive and noninvasive method of diagnosing and treating epilepsy.

[mRNA expression of activity-regulated cytoskeletal-associated protein in hippocampus induced by insular-kindled rats].

OBJECTIVE: To investigate the expression of Arc mRNA in insular electrical kindled and single electrical stimulated rats and its significance. METHODS: Male SD rats were divided randomly into kindled group, single electrical stimulated group, sham-operated group and control group. Each group was divided into 2 sub-groups at different time points. Kindled group: establishing chronic insular electrical kindled model, decapitation to perform RT-PCR of Arc mRNA on hippocampus and to applying in situ hybridization of Arc mRNA on dentate gyrus; Single electrical stimulated group: using the same method as the kindled group with only electrical stimulation twice; Sham-operated group: using the same method to the kindled group without electrical stimulation; CONTROL GROUP: no surgery. RESULTS: Expression of Arc mRNA in the hippocampus of single electrical stimulated, sham-operated and control groups were 0.72 ± 0.14, 0.75 ± 0.16 and 0.71 ± 0.14 respectively. They were significantly less than the kindled group of 1.78 ± 0.43(P < 0.01) at 3 h. The expression of Arc mRNA had no significant difference (P > 0.05) among 4 groups at 6 h; in situ hybridization (cell count) of Arc mRNA showed the expression of Arc mRNA in the kindled group was 112.8 ± 6.0. And it was significantly higher than the other three groups of 46.25 ± 4.35, 45.25 ± 6.23, 44.75 ± 6.49 (P < 0.01) after 3 h, there were no significant difference among 4 groups at 6 h (P > 0.05). CONCLUSION: Insular epilepsy increase the expression of Arc mRNA in hippocampus. Arc may play an important role in the synaptic plasticity of insular epilepsy.