Some active metal oxides(Al_(2)O_(3),TiO_(2),and Cr_(2)O_(3))were selected as dopants to the Al_(2)O_(3)-based ceramic shells for investment casting of K417G superalloy.The effects of dopant types and contents(0,2,5,a...Some active metal oxides(Al_(2)O_(3),TiO_(2),and Cr_(2)O_(3))were selected as dopants to the Al_(2)O_(3)-based ceramic shells for investment casting of K417G superalloy.The effects of dopant types and contents(0,2,5,and 8 wt.%)on the wettability and interfacial reaction between the alloy and shell were investigated by a sessile-drop experiment.The results show that increasing the Al_(2)O_(3) doping contents(0−8 wt.%)reduces the porosity(21.74%−10.08%)and roughness(3.22−1.34μm)of the shell surface.The increase in Cr_(2)O_(3) dopant content(2−8 wt.%)further exacerbates the interfacial reaction,leading to an increase in the thickness of the reaction layer(2.6−3.1μm)and a decrease in the wetting angle(93.9°−91.0°).The addition of Al_(2)O_(3) and TiO_(2) dopants leads to the formation of Al_(2)TiO_(5) composite oxides in the reaction products,which effectively inhibits the interfacial reaction.The increase in TiO_(2) dopant contents(0−8 wt.%)further promotes the formation of Al_(2)TiO_(5),which decreases the thickness of the interfacial reaction layer(3.9−1.2μm)and increases the wetting angle(95.0°−103.8°).The introduced dopants enhance the packing density of the shell surface,while simultaneously suppress the diffusion of active metal elements from the alloy matrix to the interface.展开更多
Background Increased backfat thickness of sows in early gestation is negative to reproductive performance.Endometrial receptivity is an important determinant of reproductive success,but it is unclear whether the effec...Background Increased backfat thickness of sows in early gestation is negative to reproductive performance.Endometrial receptivity is an important determinant of reproductive success,but it is unclear whether the effect of sow backfat thickness on litter size is associated with endometrial receptivity and whether melatonin treatment may have benefits.The present study seeks to answer these questions through in vitro and in vivo investigations.Results Excessive lipid deposition and lower melatonin levels in the uterus are detrimental to endometrial receptivity and embryo implantation in high backfat thickness sows.In cells treated with melatonin,the MT2/PI3K/LIF axis played a role in reducing lipid accumulation in porcine endometrial epithelium cells and improved endometrial receptivity.Furthermore,we found a reduction of lipids in the uterus after eight weeks of intraperitoneal administration of melatonin to HFD mice.Notably,melatonin treatment caused a significant reduction in the deposition of endometrial collagen,an increase in the number of glands,and repair of the pinopode structure,ultimately improving endometrial receptivity,promoting embryo implantation,and increasing the number of litter size of mice.Conclusions Collectively,the finding reveals the harmful effects of high backfat thickness sows on embryo implantation and highlight the role of melatonin and the MT2/PI3K/LIF axis in improving endometrial receptivity by enhancing metabolism and reducing the levels of uterine lipids in obese animals.展开更多
OBJECTIVE:To investigate the effects of Jiawei Huangqi Guizhi decoction(加味黄芪桂枝汤)on chronic atrophic gastritis(CAG)in rats and its modulation of the phosphatidylinositol 3-kinase/protein kinase B/mechanistic tar...OBJECTIVE:To investigate the effects of Jiawei Huangqi Guizhi decoction(加味黄芪桂枝汤)on chronic atrophic gastritis(CAG)in rats and its modulation of the phosphatidylinositol 3-kinase/protein kinase B/mechanistic target of rapamycin complex 2(PI3K/Akt/m TORC2)signaling pathway.METHODS:CAG was induced in rats and treated with high-,medium-,or low-dose Jiawei Huangqi Guizhi decoction.Gastric histopathology was observed by hematoxylin and eosin staining.Serum levels of gastrin,PI3K,Akt,and m TORC2 were detected by enzyme-linked immunosorbent assay.Gene and protein expression levels were analyzed by reverse transcription polymerase chain reaction and western blot.RESULTS:The decoction alleviated gastric mucosal injury,reduced inflammation,and restored epithelial structure.It regulated PI3K,Akt,and m TORC2 expression at both m RNA and protein levels.CONCLUSION:Jiawei Huangqi Guizhi decoction may prevent CAG progression by improving gastric tissue and modulating the PI3K/Akt/m TORC2 signaling pathway.展开更多
BACKGROUND Gastric cancer(GC)is a widespread malignancy and associated with high rates of morbidity and mortality worldwide.AIM To examine the functional role of long non-coding RNAs small nucleolar RNA host gene 5(SN...BACKGROUND Gastric cancer(GC)is a widespread malignancy and associated with high rates of morbidity and mortality worldwide.AIM To examine the functional role of long non-coding RNAs small nucleolar RNA host gene 5(SNHG5)and its regulation of miR-92a-3p and B-cell translocation gene 2(BTG2)in GC progression.METHODS Quantitative reverse transcription PCR and western blot analysis determined the expression of SNHG5,miR-92a-3p,and BTG2 in GC and adjacent non-neoplastic mucosa.Dual-luciferase assays demonstrated interactions of SNHG5 with miR-92a-3p and BTG2.AGS cells were transfected with SNHG5 overexpression and miR-92a-3p knockdown models.Various assays,including CCK-8,colony formation,scratch wound healing,and Transwell assays,were used to determine cell proliferation and migration.An experimental model of a xenograft mouse was used to determine in vivo tumor growth.At the same time histological changes were evaluated by hematoxylin and eosin staining,with western blot analysis used to evaluate signaling pathway protein expression.RESULTS BTG2 and SNHG5 were downregulated in GC tissues,and miR-92a-3p was upregulated.Overexpression of SNHG5 or knockdown of miR-92a-3p reduced GC cell proliferation and migration,and increased BTG2 expression while decreasing PI3K/AKT signaling activity.The dual-luciferase assays demonstrated direct binding of miR-92a-3p to SNHG5 and BTG2.Tumor volume and weight were significantly reduced in mice transplanted with AGS cells treated with miR-92a-3p inhibitor or SNHG5 overexpression compared with control AGS cells.Hematoxylin and eosin staining revealed that treated tumors exhibited degenerative characteristics,including irregular morphology and nucleolysis.CONCLUSION LncRNA SNHG5 inhibited GC cell growth and migration by modulating the PI3K/AKT pathway via the miR-92a-3p/BTG2 axis.展开更多
In situ quick X-ray absorption spectroscopy(QXAFS) at the Cu and Zn K-edge under operando conditions has been used to unravel the Cu/Zn interaction and identify possible active site of CuO/ZnO/Al_2O_3 catalyst for met...In situ quick X-ray absorption spectroscopy(QXAFS) at the Cu and Zn K-edge under operando conditions has been used to unravel the Cu/Zn interaction and identify possible active site of CuO/ZnO/Al_2O_3 catalyst for methanol synthesis. In this work, the catalyst, whose activity increases with the reaction temperature and pressure, was studied at calcined, reduced, and reacted conditions. TEM and EDX images for the calcined and reduced catalysts showed that copper was distributed uniformly at both conditions. TPR profile revealed two reduction peaks at 165 and 195 °C for copper species in the calcined catalyst. QXAFS results demonstrated that the calcined form consisted mainly of a mixed Cu O and Zn O, and it was progressively transformed into Cu metal particles and dispersed Zn O species as the reduction treatment. It was demonstrated that activation of the catalyst precursor occurred via a Cu^+intermediate, and the active catalyst predominantly consisted of metallic Cu and Zn O evenunder higher pressures. Structure of the active catalyst did not change with the temperature or pressure, indicating that the role of the Zn was mainly to improve Cu dispersion.This indicates the potential of QXAFS method in studying the structure evolutions of catalysts in methanol synthesis.展开更多
A series of CuO/ZnO/Al_2O_3, CuO/ZnO/ZrO_2/Al_2O_3 and CuO/ZnO/CeO_2/Al_2O_3 catalysts were prepared by coprecipitation and characterized by N_2 adsorption, XRD, TPR, N_2O titration and HRTEM. The catalytic performanc...A series of CuO/ZnO/Al_2O_3, CuO/ZnO/ZrO_2/Al_2O_3 and CuO/ZnO/CeO_2/Al_2O_3 catalysts were prepared by coprecipitation and characterized by N_2 adsorption, XRD, TPR, N_2O titration and HRTEM. The catalytic performances of these catalysts for the steam reforming of methanol were evaluated in a laboratory-scale fixed-bed reactor at 0.1 MPa and temperatures between 473 and 543 K. The results showed that the catalytic activity depended greatly on the catalyst reducibility and the specific surface area of Cu. An approximate linear correlation between the catalytic activity and the Cu surface area was found for all catalysts investigated in this study.Compared to CuO/ZnO/Al_2O_3, the ZrO_2-doped CuO/ZnO/Al_2O_3 exhibited higher activity and selectivity to CO,while the CeO_2-doped catalyst displayed lower activity and selectivity. Finally, an intrinsic kinetic study was carried out over a screened CuO/ZnO/CeO_2/Al_2O_3 catalyst in the absence of internal and external mass transfer effects. A good agreement was observed between the model-derived effluent concentrations of CO(CO_2) and the experimental data. The activation energies for the reactions of methanol-steam reforming, water-gas shift and methanol decomposition over CuO/ZnO/CeO_2/Al_2O_3 were 93.1, 85.1 and 116.5 k J·mol^(-1), respectively.展开更多
The CuO/γ-Al2O3/cordierite catalyst, after being sulfated by sulfur dioxide (SO2) at 673 K, exhibits high activities for selective catalytic reduction (SCR) of nitrogen oxide (NO) with ammonia (NH3) at 573-723 K. The...The CuO/γ-Al2O3/cordierite catalyst, after being sulfated by sulfur dioxide (SO2) at 673 K, exhibits high activities for selective catalytic reduction (SCR) of nitrogen oxide (NO) with ammonia (NH3) at 573-723 K. The intrinsic kinetics of SCR of NO with NH3 over CuO/γ-Al2O3/cordierite catalyst has been measured in a fixed-bed reactor in the absence of internal and external diffusions. The experimental results show that the reaction rate can be quantified by a first-order expression with activation energy Eá of 94.01 kJ·mol-1 and the corresponding p re-exponential factor A′ of 3.39×108 cm3·g-1·s-1 when NH3 is excessive. However, when NH3 is not enough, an E ley-Rideal kinetic model based on experimental data is derived with Ea of 105.79 kJ·mol-1, the corresponding A of 2 .94×109 cm3·g-1·s-1, heat of adsorption-Hads of 87.90 kJ·mol-1 and the corresponding Aads of 9.24 cm3·mol-1. The intrinsic kinetic model obtained was incorporated in a 3D mathematical model of monolithic reactor, and the agreement of the prediction with experimental data indicates that the present kinetic model is adequate for the reac-tor design and engineering scale-up.展开更多
基金supported by the National Natural Science Foundation of China (No. 52374292)China Baowu Low Carbon Metallurgy Innovation Foundation, China (No. BWLCF202309)the Natural Science Foundation of Changsha City, China (No. KQ2208271)。
文摘Some active metal oxides(Al_(2)O_(3),TiO_(2),and Cr_(2)O_(3))were selected as dopants to the Al_(2)O_(3)-based ceramic shells for investment casting of K417G superalloy.The effects of dopant types and contents(0,2,5,and 8 wt.%)on the wettability and interfacial reaction between the alloy and shell were investigated by a sessile-drop experiment.The results show that increasing the Al_(2)O_(3) doping contents(0−8 wt.%)reduces the porosity(21.74%−10.08%)and roughness(3.22−1.34μm)of the shell surface.The increase in Cr_(2)O_(3) dopant content(2−8 wt.%)further exacerbates the interfacial reaction,leading to an increase in the thickness of the reaction layer(2.6−3.1μm)and a decrease in the wetting angle(93.9°−91.0°).The addition of Al_(2)O_(3) and TiO_(2) dopants leads to the formation of Al_(2)TiO_(5) composite oxides in the reaction products,which effectively inhibits the interfacial reaction.The increase in TiO_(2) dopant contents(0−8 wt.%)further promotes the formation of Al_(2)TiO_(5),which decreases the thickness of the interfacial reaction layer(3.9−1.2μm)and increases the wetting angle(95.0°−103.8°).The introduced dopants enhance the packing density of the shell surface,while simultaneously suppress the diffusion of active metal elements from the alloy matrix to the interface.
基金supported by the China Agriculture Research System(CARS-35-PIG)the National Natural Science Foundation of China(32272847,U22A20516)+1 种基金the National Key Research and Development Program of China(No.2021YFF1000602)the Key Research and Development Program of Shaanxi Province(No.2022ZDLNY01–04)。
文摘Background Increased backfat thickness of sows in early gestation is negative to reproductive performance.Endometrial receptivity is an important determinant of reproductive success,but it is unclear whether the effect of sow backfat thickness on litter size is associated with endometrial receptivity and whether melatonin treatment may have benefits.The present study seeks to answer these questions through in vitro and in vivo investigations.Results Excessive lipid deposition and lower melatonin levels in the uterus are detrimental to endometrial receptivity and embryo implantation in high backfat thickness sows.In cells treated with melatonin,the MT2/PI3K/LIF axis played a role in reducing lipid accumulation in porcine endometrial epithelium cells and improved endometrial receptivity.Furthermore,we found a reduction of lipids in the uterus after eight weeks of intraperitoneal administration of melatonin to HFD mice.Notably,melatonin treatment caused a significant reduction in the deposition of endometrial collagen,an increase in the number of glands,and repair of the pinopode structure,ultimately improving endometrial receptivity,promoting embryo implantation,and increasing the number of litter size of mice.Conclusions Collectively,the finding reveals the harmful effects of high backfat thickness sows on embryo implantation and highlight the role of melatonin and the MT2/PI3K/LIF axis in improving endometrial receptivity by enhancing metabolism and reducing the levels of uterine lipids in obese animals.
基金Supported by Guangzhou Science and Technology Bureau Research Fund:the Mechanism of Action of Huangqi Guizhi Decoction on Precancerous Lesions in Cag Rats was Studied based on the Phosphatidylinositol 3-Kinase-Protein Kinase B-Mechanistic Target of Rapamycin Complex 2 Pathway(No.202102080643)Guangzhou Traditional Chinese Medicine and Integrative Medicine Research Project:Observation on the Therapeutic Effect of Wenyang Jianpi Ointment on Chronic Atrophic Gastritis of Spleen and Stomach Weakness Type and Study on its Regulatory Effect on Transforming Growth Factor Beta 3(No.20222A010079)Panyu District Science and Technology Project:the Mechanism by which the Modified Huangqi Guizhi Decoction Regulates the Transforming Growth Factor-β3 Signaling Pathway to Improve Precancerous Lesions in Rats with Chronic Atrophic Gastritis(No.2020-Z04-025)。
文摘OBJECTIVE:To investigate the effects of Jiawei Huangqi Guizhi decoction(加味黄芪桂枝汤)on chronic atrophic gastritis(CAG)in rats and its modulation of the phosphatidylinositol 3-kinase/protein kinase B/mechanistic target of rapamycin complex 2(PI3K/Akt/m TORC2)signaling pathway.METHODS:CAG was induced in rats and treated with high-,medium-,or low-dose Jiawei Huangqi Guizhi decoction.Gastric histopathology was observed by hematoxylin and eosin staining.Serum levels of gastrin,PI3K,Akt,and m TORC2 were detected by enzyme-linked immunosorbent assay.Gene and protein expression levels were analyzed by reverse transcription polymerase chain reaction and western blot.RESULTS:The decoction alleviated gastric mucosal injury,reduced inflammation,and restored epithelial structure.It regulated PI3K,Akt,and m TORC2 expression at both m RNA and protein levels.CONCLUSION:Jiawei Huangqi Guizhi decoction may prevent CAG progression by improving gastric tissue and modulating the PI3K/Akt/m TORC2 signaling pathway.
文摘BACKGROUND Gastric cancer(GC)is a widespread malignancy and associated with high rates of morbidity and mortality worldwide.AIM To examine the functional role of long non-coding RNAs small nucleolar RNA host gene 5(SNHG5)and its regulation of miR-92a-3p and B-cell translocation gene 2(BTG2)in GC progression.METHODS Quantitative reverse transcription PCR and western blot analysis determined the expression of SNHG5,miR-92a-3p,and BTG2 in GC and adjacent non-neoplastic mucosa.Dual-luciferase assays demonstrated interactions of SNHG5 with miR-92a-3p and BTG2.AGS cells were transfected with SNHG5 overexpression and miR-92a-3p knockdown models.Various assays,including CCK-8,colony formation,scratch wound healing,and Transwell assays,were used to determine cell proliferation and migration.An experimental model of a xenograft mouse was used to determine in vivo tumor growth.At the same time histological changes were evaluated by hematoxylin and eosin staining,with western blot analysis used to evaluate signaling pathway protein expression.RESULTS BTG2 and SNHG5 were downregulated in GC tissues,and miR-92a-3p was upregulated.Overexpression of SNHG5 or knockdown of miR-92a-3p reduced GC cell proliferation and migration,and increased BTG2 expression while decreasing PI3K/AKT signaling activity.The dual-luciferase assays demonstrated direct binding of miR-92a-3p to SNHG5 and BTG2.Tumor volume and weight were significantly reduced in mice transplanted with AGS cells treated with miR-92a-3p inhibitor or SNHG5 overexpression compared with control AGS cells.Hematoxylin and eosin staining revealed that treated tumors exhibited degenerative characteristics,including irregular morphology and nucleolysis.CONCLUSION LncRNA SNHG5 inhibited GC cell growth and migration by modulating the PI3K/AKT pathway via the miR-92a-3p/BTG2 axis.
基金supported by the National Basic Research Program of China(973 Program,2013CB933104)the National Natural Science Foundation of China(Nos.11275258 and 11135008)
文摘In situ quick X-ray absorption spectroscopy(QXAFS) at the Cu and Zn K-edge under operando conditions has been used to unravel the Cu/Zn interaction and identify possible active site of CuO/ZnO/Al_2O_3 catalyst for methanol synthesis. In this work, the catalyst, whose activity increases with the reaction temperature and pressure, was studied at calcined, reduced, and reacted conditions. TEM and EDX images for the calcined and reduced catalysts showed that copper was distributed uniformly at both conditions. TPR profile revealed two reduction peaks at 165 and 195 °C for copper species in the calcined catalyst. QXAFS results demonstrated that the calcined form consisted mainly of a mixed Cu O and Zn O, and it was progressively transformed into Cu metal particles and dispersed Zn O species as the reduction treatment. It was demonstrated that activation of the catalyst precursor occurred via a Cu^+intermediate, and the active catalyst predominantly consisted of metallic Cu and Zn O evenunder higher pressures. Structure of the active catalyst did not change with the temperature or pressure, indicating that the role of the Zn was mainly to improve Cu dispersion.This indicates the potential of QXAFS method in studying the structure evolutions of catalysts in methanol synthesis.
基金Supported by the National Natural Science Foundation of China(21276076)the Program for New Century Excellent Talents in University(NCET-13-0801)the"111"Project(B08021)
文摘A series of CuO/ZnO/Al_2O_3, CuO/ZnO/ZrO_2/Al_2O_3 and CuO/ZnO/CeO_2/Al_2O_3 catalysts were prepared by coprecipitation and characterized by N_2 adsorption, XRD, TPR, N_2O titration and HRTEM. The catalytic performances of these catalysts for the steam reforming of methanol were evaluated in a laboratory-scale fixed-bed reactor at 0.1 MPa and temperatures between 473 and 543 K. The results showed that the catalytic activity depended greatly on the catalyst reducibility and the specific surface area of Cu. An approximate linear correlation between the catalytic activity and the Cu surface area was found for all catalysts investigated in this study.Compared to CuO/ZnO/Al_2O_3, the ZrO_2-doped CuO/ZnO/Al_2O_3 exhibited higher activity and selectivity to CO,while the CeO_2-doped catalyst displayed lower activity and selectivity. Finally, an intrinsic kinetic study was carried out over a screened CuO/ZnO/CeO_2/Al_2O_3 catalyst in the absence of internal and external mass transfer effects. A good agreement was observed between the model-derived effluent concentrations of CO(CO_2) and the experimental data. The activation energies for the reactions of methanol-steam reforming, water-gas shift and methanol decomposition over CuO/ZnO/CeO_2/Al_2O_3 were 93.1, 85.1 and 116.5 k J·mol^(-1), respectively.
基金Supported by the National Natural Science Foundation of China （20821004 20736001 21076008） the Research Fund for the Doctoral Program of Higher Education of China （2090010110002）
文摘The CuO/γ-Al2O3/cordierite catalyst, after being sulfated by sulfur dioxide (SO2) at 673 K, exhibits high activities for selective catalytic reduction (SCR) of nitrogen oxide (NO) with ammonia (NH3) at 573-723 K. The intrinsic kinetics of SCR of NO with NH3 over CuO/γ-Al2O3/cordierite catalyst has been measured in a fixed-bed reactor in the absence of internal and external diffusions. The experimental results show that the reaction rate can be quantified by a first-order expression with activation energy Eá of 94.01 kJ·mol-1 and the corresponding p re-exponential factor A′ of 3.39×108 cm3·g-1·s-1 when NH3 is excessive. However, when NH3 is not enough, an E ley-Rideal kinetic model based on experimental data is derived with Ea of 105.79 kJ·mol-1, the corresponding A of 2 .94×109 cm3·g-1·s-1, heat of adsorption-Hads of 87.90 kJ·mol-1 and the corresponding Aads of 9.24 cm3·mol-1. The intrinsic kinetic model obtained was incorporated in a 3D mathematical model of monolithic reactor, and the agreement of the prediction with experimental data indicates that the present kinetic model is adequate for the reac-tor design and engineering scale-up.
