MiR-495-3p facilitates colon cancer cell proliferation via Wnt/β-catenin signaling pathway by restraining Wnt inhibitory factor

Purpose: To demonstrate whether miR-495-3p promote the occurrence of colon cancer and development of colon cancer stem cells by inhibiting Wnt inhibitory factor (WIF1).Methods: The level of MiRNA and mRNA in cells were tested by real-time polymerase chain reaction (RT-PCR). Cell viability was assessed by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay. Cell spheroid formation was measured by colony assay. Expression protein was tested using Western blotting. β-catenin binding ability was detected by chromatin immunoprecipitation (ChIP) assay. MiRNA target gene was defined by luciferase assay.Results: Compared with normal colon cells and tissue, miR-495-3p is elevated in colon cancer cells and tissues, which regulate proliferation, level of stemness factors SOX-9, Bmil, and OCT-4 in HCT-116 cells, even spheroid formation. Overexpression of miR-495-3p inhibits the expression of WIF1 in HCT-116 cells and promotes colon tumorigenesis by binding with 3’-UTR. MiR-495-3p inhibitor downregulated WIF1-enhanced sphere formation of colon cancer cells.Conclusion: These results indicate that miR-495-3p/WIF1 can modulate the development of colon cancer and is a potential target for prevention and treatment of cancer.Keywords: MiR-495-3p, Wnt inhibitory factor, Colon cancer, Stemness, Tumorigenesi

Fatigue Damage Analysis of Composite Insulator Cor Rod/sheath Interface

A self-made fatigue testing machine was used to simulate the damage process of the insulator interface under working conditions and the damage degree is evaluated by the compressive shear test. The improved interface adhesion model reflects the interface debonding process under different fatigue loads by introducing the damage coefficient χ, migration coefficient α and the debonding coefficient μ. The relationship of fatigue loads and interface damage is established by the peeling force, the unit interface separation work and the peeling time. The test demonstrates that the interface damage near the bottom of the insulator is worse than that near the middle part. The result of this analysis will be beneficial in easily finding damaged places of the insulator, and so as to reduce the power breakdown

Selective Laser Melting of Al-Cu-Mn-Mg Alloys: Processing and Mechanical Properties

Al-Cu-Mn-Mg alloys containing Zr were produced via selective laser melting (SLM). The processing parameters were analyzed via an orthogonal experiment, and the microstructure and mechanical properties of the specimens were investigated. The results showed that the laser power and scanning speed were the main factors affecting the density and hardness of the specimens. The optimal parameters for the SLM processing of Al-Cu-Mn-Mg alloy were a laser power of 300 W, scanning speed of 1100 mm/s, and hatch spacing of 0.12 mm. The microstructure of the specimen was made of fine equiaxed grains and columnar grains, and Al2Cu precipitates were found in the as-printed alloy. The alloy was isotropic, and the hardness was around 100 HV. The tensile and yield strength of the alloy were 361 MPa and 266 MPa, and the elongation was 5.4%. The superior mechanical properties can be attributed to the synergy effect of the strengthening of the grain boundary, solid solution, and precipitation

Fatigue Damage Analysis of Composite Insulator Cor Rod/sheath Interface

A self-made fatigue testing machine was used to simulate the damage process of the insulator interface under working conditions and the damage degree is evaluated by the compressive shear test. The improved interface adhesion model reflects the interface debonding process under different fatigue loads by introducing the damage coefficient χ, migration coefficient α and the debonding coefficient μ. The relationship of fatigue loads and interface damage is established by the peeling force, the unit interface separation work and the peeling time. The test demonstrates that the interface damage near the bottom of the insulator is worse than that near the middle part. The result of this analysis will be beneficial in easily finding damaged places of the insulator, and so as to reduce the power breakdown

Accumulation conditions and exploration potential of deep natural gas in the Qaidam Basin

This paper examines the enrichment conditions of deep natural gas reservoirs in the Qaidam Basin and delineates the exploration potential utilizing seismic, geological, geochemical, well-logging, and drilling data. The findings indicate the presence of two high-quality gas source formations, namely the Jurassic and Paleogene formations, along the northern margin and the western part of the basin, respectively. The formations both exhibit advanced evolution and robust gas-generating capacity. The deep layers along the northern margin consist of bedrocks and Paleogene clastic reservoirs, while the western deep layers feature Paleogene lacustrine carbonate reservoirs. The reservoirs west of Qaidam Basin are widely distributed on the plane and vertically form multiple reservoir cap combinations. The primary pores, dissolution pores, fractures, and other pore types developed in the reservoirs are considered as the storage space for deep gas accumulation. The continuous active deep faults serve as high-quality channels for deep gas sources; furthermore, the formation of deep structures is well-matched with natural gas generation. The deep hydrocarbon source rocks in the western Qaidam Basin are characterized by early and continuous hydrocarbon generation. Early-generated liquid hydrocarbons undergo high-temperature cracking into gas during later burial, resulting in a robust gas-generating capacity and significant potential for deep resources. The widely developed salt rocks, argillaceous rock, and abnormally high-pressure layers in the deep Qaidam Basin contribute to preserving deep natural gas. In conclusion, it is believed that deep gas reservoirs in the Qaidam Basin are enriched in the traps around hydrocarbon-generating sags with developed faults. Key favorable areas for deep-seated natural gas exploration include the basement rocks of the ancient piedmont uplift in the northern margin of Qaidam, the Paleogene clastic rocks in the central structural belt, and the carbonate rocks along the Yingxiongling structural belt in the western part of the basin

Study on defects of Zr-containing Al–Cu–Mn–Mg alloys manufactured by selective laser melting

The effects of selective laser melting (SLM) parameters on the formability, microstructure, and mechanical properties of Zr-containing Al–1Cu–1Mg–3Mn alloys were investigated. It was observed that, under different energy density, the type, shape, volume, and number of defects were different. At a lower energy density, cracks and irregular holes occurred, and with an increase in the energy density, the holes gradually became spherical. The mechanism diagram for the hole formation was drawn, and the reason for crack formation was described. The microstructure of the specimen was made of equiaxed and columnar grains, and Al2Cu and Al6Mn precipitates were found both at the grain boundaries and inside the grains. The electron backscattered diffraction (EBSD) indicated that the large columnar grains in the centre primarily exhibited the {001} and {101} orientations. In the equiaxed grain region, the grain orientation along {111} was enhanced. A hardness test revealed that the hardness of cross section and longitudinal section of the alloy was basically the same. When the energy density was 3.06 J/mm2, the tensile and yield strength of the alloy were 434 MPa and 336 MPa, respectively, and the elongation was 4.8 %

Beta-adrenergic activation induces cardiac collapse by aggravating cardiomyocyte contractile dysfunction in bupivacaine intoxication.

In order to determine the role of the adrenergic system in bupivacaine-induced cardiotoxicity, a series of experiments were performed. In an animal experiment, male Sprague-Dawley (SD) rats under chloral hydrate anesthesia received intravenous bupivacaine, followed by an intravenous injection of adrenalin or isoprenalin, and the electrocardiogram (ECG), left ventricular systolic pressure (LVSP), left ventricular end-diastolic pressure (LVEDP), the maximum rate of rise of left ventricular pressure (+dP/dtmax) and the maximum rate of pressure decrease (-dP/dtmax) were continually monitored. In a cellular experiment, freshly isolated adult SD rat ventricular myocytes were perfused with bupivacaine at different concentrations in the presence or absence of isoprenalin, with or without esmolol. The percentage of the sarcomere shortening (bl% peak h), departure velocity (dep v) of sarcomere shortening and time to 50% of the peak speed of myocyte contraction (Tp50) was assessed by a video-based edge-detection system. In an additional experiment, Swiss mice pretreated with saline, isoprenalin, esmolol or dexmedetomidine received bupivacaine to determine the 50% lethal dose (LD50) of bupivacaine. Electron microscopy of myocardial mitochondria was performed to assess damage of these structures. To test mitochondrial reactive oxygen species (ROS) production, freshly isolated SD rat ventricular myocytes were incubated with bupivacaine in the presence of isoprenalin, with or without esmolol. First, our results showed that bupivacaine significantly reduced the LVSP and +dP/dtmax, as well as enhanced the LVEDP and -dP/dtmax (P < 0.05, vs. control, and vs. baseline). Adrenalin and isoprenalin induced a further reduction of LVSP and +dP/dtmax (P < 0.05, vs. before adrenalin or isoprenalin delivery, and vs. control). Second, bupivacaine induced a dose-dependent cardiomyocyte contractile depression. While 5.9 μmol/L or 8.9 μmol/L of bupivacaine resulted in no change, 30.0 μmol/L of bupivacaine prolonged the Tp50 and reduced the bl% peak h and dep v (P < 0.05, vs. control and vs. baseline). Isoprenalin aggravated the bupivacaine-induced cardiomyocyte contractile depression, significantly prolonging the Tp50 (P < 0.05, vs. bupivacaine alone) and reducing the dep v (P < 0.05, vs. bupivacaine alone). Third, esmolol and dexmedetomidine significantly enhanced, while isoprenalin significantly reduced, the LD50 of bupivacaine in mice. Fourth, bupivacaine led to significant mitochondrial swelling, and the extent of myocardial mitochondrial swelling in isoprenalin-pretreated mice was significantly higher than that compared with mice pretreated with saline, as reflected by the higher mitochondrial damage score (P < 0.01). Meanwhile, esmolol pretreatment significantly reduced the mitochondrial damage score (P < 0.01). Fifth, bupivacaine significantly increased the ROS in freshly isolated cardiomyocytes, and added isoprenalin induced a further enhancement of ROS production (P < 0.05, vs. bupivacaine alone). Added esmolol significantly decreased ROS production (P < 0.05, vs. bupivacaine + isoprenalin). Our results suggest that bupivacaine depressed cardiac automaticity, conductivity and contractility, but the predominant effect was contractile dysfunction which resulted from the disruption of mitochondrial energy metabolism. β-adrenergic activation aggravated the cellular metabolism disorder and therefore contractile dysfunction

Geological features and exploration fields of tight oil in the Cenozoic of western Qaidam Basin, NW China

Using a large amount of drilling and experimental analysis data, this paper evaluates four potential fields of tight oil exploration in western Qaidam Basin from comprehensive analysis of geological conditions such as sedimentary environments, source rock evaluations, reservoir characteristics, and source-reservoir relationships. Influenced by continuous uplift of Tibet Plateau since Paleogene, the sedimentary environment of the western Qaidam Basin exibits three characteristics: (1) a paleo-topographic configuration consisted of inherited slopes, depressions and paleohighs; (2) frequent alternation of relative humid and arid paleoclimate; and (3) oscillation of salinity and level of the paleo-lake water. Preferential paleo-environment resulted in two sets of large-scale source rocks with high efficiency and two types of large-scale tight reservoir rocks (siliclastic and carbonate), deposited during the late Paleogene to early Neogene. The above source and reservoir rocks form favorable spatial relationships which can be classified into three categories: symbiotic, inter and lateral. Based on sedimentary environments and reservoir types, tight oil resource in western Qaidam Basin can be divided into four types, corresponding to four exploration fields: salty lacustrine carbonate tight oil, shallow lake beach-bar sandstone tight oil, delta-front-sandstone tight oil and deep lake gravity-flow-sandstone tight oil. The temporal and spatial distribution of tight oil has characteristics of layer concentration, strong regularity and large favorable area, in which the saline lacustrine carbonate and shallow lake beach-bar sandstone tight oil are the best exploration targets in the western Qaidam Basin. Key words: tight oil, geological features, exploration fields, Qaidam Basin, tight reservoi

Development, sand control mechanism and hydrocarbon accumulation of beach-bar sandstone in a saline lake basin: A case from the Neogene of southwestern Qaidam Basin, NW China

Based on the data of field outcrops, drilling cores, casting thin sections, well logging interpretation, oil/gas shows during drilling, and oil/gas testing results, and combined with modern salt-lake sediments in the Qinghai Lake, the Neogene saline lake beach-bars in southwestern Qaidam Basin are studied from the perspective of sedimentary characteristics, development patterns, sand control factors, and hydrocarbon accumulation characteristics. Beach-bar sand bodies are widely developed in the Neogene saline lake basin, and they are lithologically fine sandstone and siltstone, with wavy bedding, low-angle cross bedding, and lenticular-vein bedding. In view of spatial-temporal distribution, the beach-bar sand bodies are stacked in multiple stages vertically, migratory laterally, and extensive and continuous in NW−SE trending pattern in the plane. The stacking area of the Neogene beach-bar sandstone is predicted to be 3 000 km2. The water salinity affects the sedimentation rate and offshore distance of beach-bar sandstone, and the debris input from the source area affects the scale and enrichment of beach-bar sandstone. The ancient landform controls the morphology and stacking style of beach-bar sandstone, and the northwest monsoon driving effect controls the long-axis extension direction of beach-bar sandstone. The beach-bars have a reservoir-forming feature of “one reservoir in one sand body”, with thick beach-bar sand bodies controlling the effective reservoir distribution and oil-source faults controlling the oil/gas migration and accumulation direction. Three favorable exploration target zones in Zhahaquan, Yingdong−eastern Wunan and Huatugou areas are proposed based on the analysis of reservoir-forming elements