Freezing Shrinkage Dynamics and Surface Dendritic Growth of Floating Refractory Alloy Droplets in Outer Space.

The freezing shrinkage and dendritic growth are of great importance for various alloys solidified from high-temperature liquids to solids since they dominate microstructure patterns and follow-up processing. However, the microgravity freezing shrinkage dynamics is scarcely explored on the ground as it is hard to suppress the strong natural convection inside liquid alloys. Here, a series of in-orbit solidification experiments is conducted aboard the China Space Station with a long-term stable 10-5 g0 microgravity condition. The highest temperature up to 2265 K together with substantial liquid undercoolings far from a thermodynamically stable state are attained for both Nb82.7Si17.3 and Zr64V36 refractory alloys. Furthermore, the solidification under microgravity of a droplet is simulated to reveal the liquid-solid interface migration, temperature gradient, and flow field. The microgravity solidification process leads to freezing shrinkage cavities and distinctive surface dendritic microstructure patterns. The combined effects of shrinkage dynamics and liquid surface flow in outer space result in the dendrites growing not only along the tangential direction but also along the normal direction to the droplet surface. These space experimental results contribute to a further understanding of the solidification behavior of liquid alloys under a weaker convection condition, which is often masked by gravity on the ground.

Metastable Liquid Properties and Surface Flow Patterns of Ultrahigh Temperature Alloys Explored in Outer Space.

The metastable liquid properties and chemical bonds beyond 2000 K remain a huge challenge for ground-based research on liquid materials chemistry. We show the strong undercooling capability, metastable liquid properties and surface wave patterns of refractory Nb-Si and Zr-V binary alloys explored in space environment. The floating droplet of Nb82.7Si17.3 eutectic alloy superheated up to 2338 K exhibited an extreme undercooling of 437 K, approaching the 0.2TE threshold for homogeneous nucleation of liquid-solid reaction. The microgravity state endowed alloy droplets with nearly perfect sphericity and thus ensured the high accuracy to determine metastable undercooled liquid properties. A special kind of swirling flow was induced for liquid alloy owing to Marangoni convection, which resulted in the spiral microstructures on Zr64V36 alloy surface during liquid-solid phase transition. The coupled impacts of surface nucleation and surface flow brought in a novel olivary shape for these binary alloys. Furthermore, the chemical bonds and atomic structures of high temperature liquids were revealed to understand the liquid properties in outer space circumstances.

AEBP1 Contributes to Breast Cancer Progression by Facilitating Cell Proliferation, Migration, Invasion, and Blocking Apoptosis.

BACKGROUND: The aberrant expression of adipocyte enhancer binding protein 1 (AEBP1) has been observed in many cancers and it seems to be involved in the tumorigenesis, progression, and metastasis in numerous tumor types. However, the contribution of AEBP1 in breast cancer (BCa) remains inexplicable. METHODS: Information related to the diagnostic significance and expression of AEBP1 in BCa was obtained from the public dataset Kaplan-Meier Plotter (http://kmplot.com/analysis/) and the dataset UALCAN (https://ualcan.path.uab.edu/index.html). The MTT (methyl thiazolyl tetrazolium) assay, colony formation assay, Transwell® assay, and FACS (fluorescence-activated cell sorting) assay were used to detect the proliferation, invasive and apoptotic ability of cells before and after treatment. In addition, we constructed an AEBP1 overexpression vector and silenced AEBP1, combined with Real-Time Quantitative Reverse Transcription PCR (qRT-PCR), western blot, immunohistochemistry and TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling) assay to investigate the prognostic significance, biological functions and potential mechanisms of AEBP1 in BCa. RESULTS: Higher expression of AEBP1 mRNA (message RNA) was observed in BCa patients with later-stage, who obtained poorer overall survival. Meanwhile, compared with adjacent noncancerous tissues, AEBP1 protein expression was dramatically upregulated in the BCa ones. Furthermore, overexpressed AEBP1 enhanced cell proliferation, migration, invasion, and blocked cell apoptosis in BCa cells. Moreover, the research certificated that AEBP1 upregulated the expression of MMP (matrix metalloproteinase)-2, 9, vimentin, N-cadherin (neural-cadherin), phosphorylation of ERK (extracellular signal-regulated kinase), Smad2/3 (Abbreviated from Sma for nematode and Mad for Drosophila) and AKT (V-akt murine thymoma viral oncogene homolog), while down-regulated the expression of E-cadherin (epithelial cadherin) and PTEN (phosphatase and tensin homolog deleted on chromosome 10). To inhibit cell apoptosis, enforced expression of AEBP1 effectively blocked the cleavage of caspase 9 and p53 (protein 53) and promoted the expression of anti-apoptotic protein Bcl-2 (B-cell lymphoma-2). Finally, AEBP1 accelerated subcutaneously transplanted tumor growth in nude mice by increasing the expression of the cell proliferation biomarker ki67, the phosphorylation of AKT, and blocked apoptosis in vivo. CONCLUSIONS: In summary, these data suggested the important role of AEBP1 in the BCa progression, which could be used as a potential biomarker for prognostic hallmark and a novel therapeutic strategy.

Effects of 7,12-Dimethylbenz(a)anthracene on Apoptosis of Breast Cancer Cells through Regulating Expressions of FasL and Bcl-2.

To provides a reference basis for the apoptosis of breast cancer (BC) cells and the carcinogenesis of BC, the effects of 7, 12-dimethylbenz (a) anthracene (DMBA) on apoptosis regulators FasL and B-cell lymphoma-2 (Bcl-2) were investigated. In this study, 62 female C57BL/6 mice aged from 4 to 6 weeks were randomly divided into control group (CG) and test group (TG), with 31 mice in each group. The TG was given DMBA solution by gavage at a dose of 50 mg/kg, and the CG was given normal saline of equal volume. On the second day after the experiment, all the mice were killed by cervical dislocation. The morphology of the mammary gland was observed by hematoxylin-eosin (HE) staining, and the differences of FasL and Bcl-2 protein expression (PE) were detected by immunohistochemistry. The mRNA expression levels of FasL and Bcl-2 were detected by quantitative real-time PCR (qPCR). Breast cell apoptosis status of mice in the two groups was detected by the terminal deoxyribonucleotidyl transferase (TdT)-mediated biotin-16-dUTP nick-end labelling (TUNEL) method. The results showed that after HE staining, the tumor cells in the TG were stacked up to form a substantial structure. The expression level of FasL protein in the CG was greatly lower than that in the TG, and the positive rate (PR) was 20.25%, which was greatly lower than that of 89.65% in the TG (P<0.01). The expression level of Bcl-2 protein in the mammary gland tissues (MGTs) of mice in the TG was greatly higher than that of the CG, and its PR was 87.96%, which was greatly higher than that of 31.48% in the CG (P<0.01). The expression levels of FasL mRNA in the MGTs of mice in the TG and CG were 5.82±4.37 and 1.27±0.12, respectively, and there was a statistically obvious difference (P<0.05). The mRNA expression levels of Bcl-2 in the TG and the CG were 18.97±2.65 and 2.02±0.54, respectively, and there was an extremely obvious difference (P<0.01). The apoptosis rate of mammary gland cells in the TG was (19.79±3.53) %, and that in the CG was (2.93±0.28) %, and there was an extremely obvious difference (P<0.01). It indicated that DMBA inhibited the apoptosis of BC cells by regulating the up-regulation of FasL and Bcl-2 expression.

[The Expression and Significance of Serum Protein ROCK2 in Patients with Chronic Graft-Versus-Host Disease].

OBJECTIVE: To investigate the expression and clinical significance of serum protein ROCK2 in patients with chronic graft-versus-host disease (cGVHD) after allogeneic hematopoietic stem cell transplantation (allo-HSCT). METHODS: The patients were divided into cGVHD group and control group (without cGVHD). The expression levels of serum protein ROCK2 were detected by ELISA in patients with or without cGVHD after allo-HSCT. RESULTS: The expression level of ROCK2 in serum of cGVHD patients was significantly higher than those in control group, moreover, the expression level of ROCK2 in severe cGVHD group was significant higher than that in moderate and mild cGVHD group (P<0.001). The expression level of ROCK2 was significantly decreased in the serum of cGVHD patients after treatment（P＜0.01）; the expression level of ROCK2 was significantly higher in the serum of cGVHD patients with lung as the target organ（P＜0.01）. The median survival time of patients with severe cGVHD were significantly shorter than that of patients with mild and moderate cGVHD（P＜0.05）. CONCLUSION: ROCK2 shows certain reference value in the evaluation of severity and prognosis of cGVHD, and may be a new target for the treatment of cGVHD.

Update on the Relationship Between Depression and Neuroendocrine Metabolism.

Through the past decade of research, the correlation between depression and metabolic diseases has been noticed. More and more studies have confirmed that depression is comorbid with a variety of metabolic diseases, such as obesity, diabetes, metabolic syndrome and so on. Studies showed that the underlying mechanisms of both depression and metabolic diseases include chronic inflammatory state, which is significantly related to the severity. In addition, they also involve endocrine, immune systems. At present, the effects of clinical treatments of depression is limited. Therefore, exploring the co-disease mechanism of depression and metabolic diseases is helpful to find a new clinical therapeutic intervention strategy. Herein, focusing on the relationship between depression and metabolic diseases, this manuscript aims to provide an overview of the comorbidity of depression and metabolic.