New insights into the formation of the blue main sequence in NGC 1850

Recent discoveries of bimodal main sequences (MSs) associated with young clusters (with ages $\lesssim 1$ Gyr) in the Magellanic Clouds have drawn a lot of attention. One of the prevailing formation scenarios attributes these split MSs to a bimodal distribution in stellar rotation rates, with most stars belonging to a rapidly rotating population. In this scenario, only a small fraction of stars populating a secondary blue sequence are slowly or non-rotating stars. Here, we focus on the blue MS in the young cluster NGC 1850. We compare the cumulative number fraction of the observed blue-MS stars to that of the high-mass-ratio binary systems at different radii. The cumulative distributions of both populations exhibit a clear anti-correlation, characterized by a highly significant Pearson coefficient of $-0.97$. Our observations are consistent with the possibility that blue-MS stars are low-mass-ratio binaries, and therefore their dynamical disruption is still ongoing. High-mass-ratio binaries, on the other hand, are more centrally concentrated.Comment: 8 pages, 6 figures, accepted to Ap

The Effect of Hexavalent Chromium on the Incidence and Mortality of Human Cancers: A Meta-Analysis Based on Published Epidemiological Cohort Studies

Background: Hexavalent chromium [Cr(VI)] is an occupational carcinogen that can cause lung and nasal cancers, but its association with mortality and incidence in many other cancers is unclear.Objectives: In this meta-analysis, we aimed to evaluate the relationship between exposure to Cr(VI) and the mortality and incidence of human cancers.Methods: We performed a search of the literature and extracted the standardized mortality ratios (SMRs), standardized incidence ratios (SIRs), and their corresponding 95% confidence intervals (CIs), to estimate risk values. Subgroup analyses were conducted by sex, occupation, and types of cancer to identify groups that were at high-risk or predisposed to certain cancers.Results: A total of 47 cohort studies covering the period 1985–2016 were included (37 studies reporting SMRs and 16 studies reporting SIRs). The summary SMR for all studies combined was 1.07 (95% CI: 1.01–1.15). Summary SMRs were higher among chromate production workers, chrome platers, and masons, and especially male workers. In the subgroup analysis, Cr(VI) exposure was related to a higher risk of death owing to lung, larynx, bladder, kidney, testicular, bone, and thyroid cancer. The meta-SIR of all studies combined was 1.06 (95% CI: 1.04–1.09). Summary SIRs were elevated among cement industry workers and tanners. Cr(VI) exposure was related to an elevated risk of respiratory system, buccal cavity, pharynx, prostate, and stomach cancers.Conclusions: Cr(VI) might cause cancers of the respiratory system, buccal cavity and pharynx, prostate, and stomach in humans, and it is related to increased risk of overall mortality owing to lung, larynx, bladder, kidney, testicular, bone, and thyroid cancer. In addition, there was a strong association between incidence and mortality risk of cancers and concentration of Cr(VI) in the air and the exposure time

Sodium Fluoride Arrests Renal G2/M Phase Cell-Cycle Progression by Activating ATM-Chk2-P53/Cdc25C Signaling Pathway in Mice

Background/Aims: Excessive fluoride intake can induce cytotoxicity, DNA damage and cell-cycle changes in many tissues and organs, including the kidney. However, the underlying molecular mechanisms of fluoride-induced renal cell-cycle changes are not well understood at present. In this study, we used a mouse model to investigate how sodium fluoride (NaF) induces cell-cycle changes in renal cells. Methods: Two hundred forty ICR mice were randomly assigned to four equal groups for intragastric administration of NaF (0, 12, 24 and 48 mg/kg body weight/day) for 42 days. Kidneys were taken to measure changes of the cell-cycle at 21 and 42 days of the experiment, using flow cytometry, quantitative real-time polymerase chain reaction (qRT-PCR) and western blot methods. Results: NaF, at more than 12 mg/kg body weight, induced G2/M phase cell-cycle arrest in the renal cells, which was supported by the finding of significantly increased percentages of renal cells in the G2/M phase. We found also that G2/M phase cell-cycle arrest was accompanied by up-regulation of p-ATM, p-Chk2, p-p53, p-Cdc25C, p-CDK1, p21, and Gadd45a protein expression levels; up-regulation of ATM, Chk2, p53, p21, and Gadd45a mRNA expression levels; down-regulation of CyclinB1, mdm2, PCNA protein expression levels; and down-regulation of CyclinB1, CDK1, Cdc25C, mdm2, and PCNA mRNA expression levels. Conclusion: In this mouse model, NaF, at more than 12 mg/ kg, induced G2/M phase cell-cycle arrest by activating the ATM-Chk2-p53/Cdc25C signaling pathway, which inhibits the proliferation of renal cells and development of the kidney. Activation of the ATM-Chk2-p53/Cdc25C signaling pathway is the mechanism of NaF-induced renal G2/M phase cell-cycle arrest in this model

The Effect of Suppression Taurine on Relocation and Epithelial-Mesenchymal Transition in Mankind Lung Cancer Cells

Aim. Taurine is believed to have antioxidant properties and has been implicated in the treatment of neurodegenerative disease, atherosclerosis, coronary heart disease, and prostate cancer. This research focused on taurine inhibition effects of expression related to migration and epithelial-mesenchymal transition- (EMT-) A549 study on related genes of human being non-small-cell lung cancer. Methods. MTT assays assessed cell viability and a RadiusTM assay showed that taurine also inhibited the lung cancer cell migration. Using RT-PCR and Western blot, the migration and EMT markers were identified and evaluated. Results. We found that taurine significantly decreased the expression of migration markers matrix metallopeptidase 9 (MMP-9) and vascular endothelial growth factor (VEGF). In contrast, TIMP metallopeptidase inhibitor 1 (TIMP-1) and TIMP metallopeptidase inhibitor 2 (TIMP-2) expressions were increased with taurine treatment. In addition, we found an association between taurine treatment and the expression of EMT markers. The expression of epithelial marker E-cadherin and the mesenchymal marker N-cadherin TWIST-1 was decreased, but the expression of zinc finger protein SNAIL-1 and E-zinc finger homeobox 1 (ZEB-1) was increased. Conclusion. Taken together, our study strongly suggests the therapeutic significance of taurine, which possesses antimigration activity and induces EMT markers expression in lung cancer cells

Ventilation and air conditioning system of deep-buried subway station in sub-tropical climates: Energy-saving strategies

Subway systems are rapidly developing, and their energy consumption is considerably growing. The ventilation and air conditioning system in the subway station is the key energy-consuming system. It consumes a large amount of energy every day to provide a comfortable environment for passengers, and it has therefore received increasingly more attention from researchers worldwide. In this work, the variation law of the ventilation and air conditioning system of a subway station is analyzed from three aspects (energy consumption, load, and temperature) based on field test data, and the problems existing in the operation and management of the system are analyzed. For example, the results show that the total load of fresh air in the station was as high as 34-37%, and about 30 min was required to adjust the indoor temperature to a stable state. In addition, three general models and seven energy-saving strategies are put forward, and their energy saving potentials are estimated. After optimization, the ventilation and air conditioning system is found to reduce energy consumption by more than 30%. Not only are common problems that exist in the actual operation of the subway station ventilation and air conditioning system found in this research, but valuable measured data is also provided for the theoretical research of the thermal environment of the subway and the design of environmental control systems

Research of Automatic Generation for Engineering Geological Survey Reports Based on a Four-Dimensional Dynamic Template

Errors and inefficiency may be caused by manual processing of complex templates for the preparation and management of engineering survey reports. To address this problem, this paper analyzes the multidimensional variable features of professional field documents and proposes a generation model of standardized reports based on a four-dimensional dynamic template. This approach splits the standardized report into multiple parts to construct a hierarchical tree that represents the report structure according to the report rules, then stores the tree in a graph database, and finally generates the desired report dynamically by retrieving the relational tree for the template and obtaining the relevant data. The model has been applied to the engineering geological survey report system and is shown to improve the working efficiency and data accuracy of the report preparation. Results indicate that the model is feasible and effective