Elevated duct is an atmospheric structure characterized by abnormal refractive index gradients, which can significantly affect the performance of radar, communication, and other systems by capturing a portion of elect...
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Elevated duct is an atmospheric structure characterized by abnormal refractive index gradients, which can significantly affect the performance of radar, communication, and other systems by capturing a portion of electromagnetic waves. The South China Sea (SCS) is a high-incidence area for elevated duct, so conducting detection and forecasts of the elevated duct in the SCS holds important scientific significance and practical value. This paper attempts to utilize remote sensing techniques for extracting elevated duct information. Based on GPS sounding data, a lapse rate formula (LRF) model and an empirical formula (EF) model for the estimation of the cloud top height of Stratocumulus were obtained, and then remote sensing retrieval methods of elevated duct were established based on the Moderate Resolution Imaging Spectroradiometer (MODIS) remote sensing data. The results of these two models were compared with results from the elevated duct remote sensing retrieval model developed by the United States Naval Postgraduate School. It is shown that the probability of elevated duct events was 79.1% when the presence of Stratocumulus identified using GPS sounding data, and the trapping layer bottom height of elevated duct well with the cloud top height of Stratocumulus, with a correlation coefficient of 0.79, a mean absolute error of 289 m, and a root mean square error of 598 m. Among the different retrieval models applied to MODIS satellite data, the LRF model emerged as the optimal remote sensing retrieval method for elevated duct in the SCS, showing a correlation coefficient of 0.51, a mean absolute error of 447 m, and a root mean square error of 658 m between the trapping layer bottom height and the cloud top height. Consequently, the encouraging validation results demonstrate that the LRF model proposed in this paper offers a novel method for diagnosing and calculating elevated ducts information over large-scale marine areas from remote sensing data.
The human telomerase gene (hTERT) is repressed in most somatic cells. How transcription factors activate the hTERT promoter in its repressive chromatin environment is unknown. Here, we report that the ETS family prote...
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The human telomerase gene (hTERT) is repressed in most somatic cells. How transcription factors activate the hTERT promoter in its repressive chromatin environment is unknown. Here, we report that the ETS family protein ETS variant transcription factor 5 (ETV5) mediates epidermal growth factor (EGF)-induced hTERT expression in MCF10A cells. This activation required MYC proto-oncogene bHLH transcription factor (c-Myc) and depended on the chromatin state of the hTERT promoter. Using chromatinized bacterial artificial chromosome (BAC) reporters in human fibroblasts, we found that ETV5 and c-Myc/MYC-associated factor X (MAX) synergistically activate the hTERT promoter via two identical, but inverted, composite Ets/E-box motifs enclosing the core promoter. Mutations of Ets or E-box sites in either DNA motif abolished the activation and reduced or eliminated the synergism. ETV5 and c-Myc facilitated each other's binding to the hTERT promoter. ETV5 bound to the hTERT promoter in both telomerase-negative and -positive cells, but it activated the repressed hTERT promoter and altered histone modifications only in telomerase-negative cells. The synergistic ETV5/c-Myc activation disappeared when hTERT promoter repression became relieved because of the loss of distal regulatory elements in chimeric human/mouse BAC reporters. Our results suggest that the binding of c-Myc and ETS family proteins to the Ets/E-box motifs derepresses the hTERT promoter by inducing an active promoter configuration, providing a mechanistic insight into hTERT activation during tumorigenesis.
Delayed coal bursts in deep coal mines have caused significant fatalities and economic losses in recent years. Instead of occurring right around the advancing face, this particular type of coal burst is characterized ...
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Delayed coal bursts in deep coal mines have caused significant fatalities and economic losses in recent years. Instead of occurring right around the advancing face, this particular type of coal burst is characterized by its occurrence at a certain distance behind the advancing face. To better understand the mechanism of a delayed coal burst, we used borehole camera, electromagnetic CT, and borehole deformation monitoring device to observe the fracturing and deformation process of an advancing entry's surrounding coal in the field. Borehole camera detection showed a zonal disintegration phenomenon in the advancing entry's surrounding coal. Electromagnetic CT detection showed that zonal disintegration developed within 14 days of excavation. Borehole deformation monitoring indicated a deformation rate difference between the intact zone and fractured zones. The deformation rate difference was observed to increase with time and cause increasing elastic energy accumulation in the intact zone. The cumulative elastic energy in the intact zone finally caused a delayed coal burst in the entry. Sensitivity analysis of the cumulative elastic energy was conducted based on a thick-walled model deduced from field detection. The model shows that the smaller thickness of the intact zone brings higher elastic energy in the intact zone. This investigation provides an improved understanding of delayed coal bursts in deep coal mines.
This paper examines the effectiveness of energy absorption anti-impact support in protecting the coal mine roadway from rock burst and ensuring safe production. By establishing an ABAQUS numerical model of the support...
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This paper examines the effectiveness of energy absorption anti-impact support in protecting the coal mine roadway from rock burst and ensuring safe production. By establishing an ABAQUS numerical model of the support and wall rock, the mechanical behavior of the system under static and impact loads have been investigated. The analysis includes the deformation of the wall rock, plastic strain, plastic property, and damage range to evaluate the support effect and the synergistic effect with the wall rock. The findings indicate that compared to ordinary support, the energy absorption anti-impact support exhibits a 20.40% increase in maximum deformation, 4.74% increase in maximum stress, 66.67% decrease in maximum plastic strain, and 116.79% increase in maximum absorption energy. The wall rock also experiences a 2.91% increase in maximum deformation and 10.19% increase in maximum stress. These results suggest that energy absorption anti-impact support is effective in improving the anti-impact performance of the support and providing a certain level of protection to both the support and wall rock.
Aging affects lipid metabolism and can cause obesity as it is closely related to the disorder of many lipogenic regulatory factors. LncRNAs have been recognized as pivotal regulators across diverse biological processe...
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Aging affects lipid metabolism and can cause obesity as it is closely related to the disorder of many lipogenic regulatory factors. LncRNAs have been recognized as pivotal regulators across diverse biological processes, but their effects on lipogenesis in aging remain to be further studied. In this work, using RNA sequencing (RNA-Seq), we found that the expression of lncRNA AI504432 was significantly upregulated in the eWAT (epididymal white adipose tissue) of aging mice, and the knockdown of AI504432 notably reduced the expression of several adipogenic genes (e.g., Cebp/ alpha, Srebp-1c, Fasn, Acaca, and Scd1 ) in senescent adipocytes. The bioinformatics investigation revealed that AI504432 possessed a binding site for miR-1a-3p, and the discovery was verified by the luciferase reporter assay. The expression of Fasn was increased upon the inhibition of miR-1a-3p but restored upon the simultaneous silencing of AI504432. Taken together, our results suggested that AI504432 controlled lipogenesis through the miR-1a-3p/ Fasn signaling pathway. The findings may inspire new therapeutic approaches to target imbalanced lipid homeostasis due to aging.
Primary immune thrombocytopenia (ITP) is an autoimmune haemorrhagic disease that could manifest with comorbid type 2 diabetes mellitus (T2DM). However, the exact impact of T2DM in patients with ITP remains uncertain. ...
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Primary immune thrombocytopenia (ITP) is an autoimmune haemorrhagic disease that could manifest with comorbid type 2 diabetes mellitus (T2DM). However, the exact impact of T2DM in patients with ITP remains uncertain. In this study, we performed a retrospective cohort study of 458 participants with ITP. The prevalence of T2DM was 7.6% in this population (35 patients), which was slightly lower than the Chinese nationwide prevalence of T2DM, calculated to be approximately 10.9%. The participants with pre-existing T2DM displayed a significantly higher response to therapy than those without T2DM (71% vs. 53%). Furthermore, in the T2DM cohort, the response rate reached 88% when metformin was included in the treatment regimen. This clinical evidence suggests that metformin therapy might improve the clinical outcomes of ITP.
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