Large-scale sand fracturing is a necessary means in the efficient exploitation of shale gas/oil.However,in the process of fracturing operation,the sand carrying fluid and proppant easily causes scouring and wear to pr...Large-scale sand fracturing is a necessary means in the efficient exploitation of shale gas/oil.However,in the process of fracturing operation,the sand carrying fluid and proppant easily causes scouring and wear to production strings,especially the casing perforation system,which damage the wellbore integrity and deformation to affect the subsequent fracturing.For this problem,taking the actual construction conditions and perforation technology of an oilfield in western China as an example,the structural parameters of the downhole string were measured and the wall thickness reduction model of casing perforation suitable for large-displacement sand fracturing in horizontal well section was established.With software ANSYS-FLUENT,the casing perforation erosion under the conditions of different displacements,sand content and perforation sand-passing quantity in the process of sand fracturing was simulated and calculated.The influences of three parameters on perforation erosion and expansion were analyzed and the prediction chart of the influences of three main control factors on perforation erosion and expansion was established.The perforation erosion images after fracturing construction were obtained with the downhole eagle perforation logging technology.The logging chart results were compared with the downhole eagle perforation data.The error between the established numerical simulation calculation charts and the real logging data was about 5%,indicating that the simulation charts were the valuable reference.展开更多
国内首台多路并联超高功率脉冲装置"聚龙一号"(PTS)已被用于磁驱动准等熵实验研究,其分时分组放电特点为开展材料的动高压可控路径加载研究提供了便利.磁驱动准等熵实验的物理设计和结果分析需要依赖可靠的数值模拟平台.本文...国内首台多路并联超高功率脉冲装置"聚龙一号"(PTS)已被用于磁驱动准等熵实验研究,其分时分组放电特点为开展材料的动高压可控路径加载研究提供了便利.磁驱动准等熵实验的物理设计和结果分析需要依赖可靠的数值模拟平台.本文介绍了含强度计算的一维磁流体力学程序MADE1D的物理模型和程序特点,讨论了"聚龙一号"装置两种不同电流波形驱动条件下准等熵实验的模拟情况.结果显示,MADE1D程序能够较好地反映电磁力引起的压缩波在样品内部的产生、传播及发展过程,计算获得的"样品/窗口"界面速度同实验测量结果符合较好.分析发现,电流波形是影响加载过程的重要因素.对于目前使用的带状电极,电流上升率不宜超过40 k A/ns,否则可能在厚度1.2 mm以上的铝样品中产生冲击.展开更多
In this study, we show that the percutaneous absorption and brain distribution of tetramethylpyrazine(TMP) is enhanced when combined with borneol(BN) in a microemulsionbased transdermal therapeutic system(ME-TTS). The...In this study, we show that the percutaneous absorption and brain distribution of tetramethylpyrazine(TMP) is enhanced when combined with borneol(BN) in a microemulsionbased transdermal therapeutic system(ME-TTS). The formulation of the TMP and BN microemulsion(TEM-BN-ME) was optimized in skin permeation studies in vitro following a uniform experimental design. Male Sprague-Dawley rats were used for the in vivo pharmacokinetic and tissue distribution studies of TMP-BN-ME-TTS. In the pharmacokinetic study, the TMP-BN-ME-TTS treated rats had significantly higher( P < 0.05) C max and AUC of TMP than the TMP-ME-TTS treated rats, indicating that BN improves the rate and extent of TMP percutaneous absorption. In the tissue distribution study, the AUC of TMP in brain was significantly higher in the TMP-BN-ME-TTS group( P < 0.05), indicating that BN facilitates the distribution of TMP in brain. In summary, BN enhanced the percutaneous absorption and brain distribution of TMP in a microemulsion-based transdermal therapeutic system.展开更多
考察以0.55 g/100 mL L-精氨酸(精氨酸)/L-赖氨酸(赖氨酸)+1.5 g/100 mL NaCl溶液为提取剂提取的鸡胸肉蛋白的凝胶特性。差示扫描量热法和动态流变结果表明:与对照组相比,添加精氨酸/赖氨酸的提取剂所对应的蛋白提取物在加热过程中具有...考察以0.55 g/100 mL L-精氨酸(精氨酸)/L-赖氨酸(赖氨酸)+1.5 g/100 mL NaCl溶液为提取剂提取的鸡胸肉蛋白的凝胶特性。差示扫描量热法和动态流变结果表明:与对照组相比,添加精氨酸/赖氨酸的提取剂所对应的蛋白提取物在加热过程中具有3个明显的变性温度点和4个明显的温度区间,其在加热和冷却的过程中均具有更高的储能模量;添加精氨酸/赖氨酸的提取剂所对应的蛋白提取物形成的蛋白凝胶具有连续的三维网络结构、更高的保水性和凝胶强度以及更低的蒸煮损失。因此,提取剂中包含精氨酸/赖氨酸的蛋白提取物具有更好的凝胶特性,所形成的凝胶具有更好的保水和质构等特性。展开更多
Antibiotic pollution has become a global eco-environmental issue.To reduce sulfonamide antibiotics in water and improve resource utilization of solid wastes,phosphogypsummodified biochar composite(PMBC)was prepared vi...Antibiotic pollution has become a global eco-environmental issue.To reduce sulfonamide antibiotics in water and improve resource utilization of solid wastes,phosphogypsummodified biochar composite(PMBC)was prepared via facile one-step from distillers grains,wood chips,and phosphogypsum.The physicochemical properties of PMBCwere characterized by scanning electron microscope(SEM),Fourier transform infrared spectroscopy(FTIR),Zeta potential,X-ray diffraction(XRD),etc.The influencing factors,adsorption behaviors,and mechanisms of sulfadiazine(SD)and sulfamethazine(SMT)onto PMBC were studied by batch and fixed bed column adsorption experiments.The results showed that the removal rates of SD and SMT increased with the increase of phosphogypsum proportion,while decreased with the increase of solution pH.The maximum adsorption capacities of modified distillers grain and wood chips biochars for SD were 2.98 and 4.18 mg/g,and for SMT were 4.40 and 8.91mg/g,respectively,which was 9.0–22.3 times that of pristine biochar.Fixed bed column results demonstrated that PMBC had good adsorption capacities for SD and SMT.When the solution flow rate was 2.0 mL/min and the dosage of PMBC was 5.0 g,the removal rates of SD and SMT by modified wood chips biochar were both higher than 50%in 4 hr.The main mechanisms of SD and SMT removal by PMBC are hydrogen bonding,π-πdonor-acceptor,electrostatic interaction,and hydrophobic interaction.This study provides an effective method for the removal of antibiotics in water and the resource utilization of phosphogypsum.展开更多
Several derivatives have been synthesized from chrysin, diosmetin, apigenin, and luteolin, which were isolated from diverse natural plants. The a-glucosidase inhibitory activity of these compounds was evaluated. The g...Several derivatives have been synthesized from chrysin, diosmetin, apigenin, and luteolin, which were isolated from diverse natural plants. The a-glucosidase inhibitory activity of these compounds was evaluated. The glucosidase inhibitory activity of all derivatives(IC50< 24.396 mmol/L) was higher compared with that of the reference drug, acarbose(IC50= 563.601 40.492 mmol/L), and 1-deoxynojirimycin(IC50= 226.912 12.573 mmol/L). O30,O7-Hexyl diosmetin(IC50= 2.406 0.101 mmol/L)was the most potent inhibitor identified. These compounds showed a higher inhibitory ability compared with their precursors except the luteolin derivatives. In general, the inhibitory activity of the synthetic derivatives was enhanced with long alkyl chains at positions 30, 40 and 7 of the flavonoid.展开更多
Background and Aims:Metabolic dysfunction-associ-ated fatty liver disease(MAFLD)is a new concept,pro-posed in 2020;however,its applicability in Asia populations has yet to be evaluated.Therefore,we aimed to compare th...Background and Aims:Metabolic dysfunction-associ-ated fatty liver disease(MAFLD)is a new concept,pro-posed in 2020;however,its applicability in Asia populations has yet to be evaluated.Therefore,we aimed to compare the difference in epidemiological and clinical characteris-tics between MAFLD and non-alcoholic fatty liver disease(NAFLD)among Asian populations.Methods:Based on the Jinchang cohort,30,633 participants were collected.The prevalence and incidence of MAFLD and NAFLD were used to analyze the epidemic characteristics and its overlapping effects.In addition,the corresponding clinical character-istics of the two diagnostic criteria populations were com-pared.Results:The prevalence rates of MAFLD and NAFLD were 21.03%and 18.83%,respectively.After an average 2.28-year follow-up,the incidence densities of MAFLD and NAFLD were 41.58 per 1,000 person-years and 37.69 per 1,000 person-years,respectively.With the increase of baseline age,body mass index(BMI),and waist circumfer-ence(WC)levels,the prevalence and incidence of MAFLD and NAFLD were on the rise(all ptrend<0.05).Among the total patients diagnosed at baseline or follow-up,most pa-tients had both MAFLD and NAFLD,accounting for 78.84%and 82.88%,respectively.Compared with NAFLD,MAFLD patients had greater proportions of males and metabolic diseases(diabetes,dyslipidemia),and had higher BMI,WC,liver enzymes,blood glucose,and lipid levels in the base-line diagnosis patients(p<0.05).Additionally,lean MAFLD patients had higher metabolic disorders than lean NAFLD patients(p<0.05).Conclusions:Compared with NAFLD,the newly proposed definition of MAFLD is more practical and accurate,and it can help identify more fatty liver pa-tients with high-risk diseases.展开更多
Cardiovascular disease(CVD)and environmental degradation are leading global health problems of our time.Recent studies have linked exposure to heavy metals to the risks of CVD and diabetes,particularly in populations ...Cardiovascular disease(CVD)and environmental degradation are leading global health problems of our time.Recent studies have linked exposure to heavy metals to the risks of CVD and diabetes,particularly in populations from low-and middle-income countries,where concomitant rapid development occurs.In this review,we 1)assessed the totality,quantity,and consistency of the available epidemiological studies,linking heavy metal exposures to the risk of CVD(including stroke and coronary heart disease);2)discussed the potential biological mechanisms underlying some tantalizing observations in humans;and 3)identified gaps in our knowledge base that must be investigated in future work.An accumulating body of evidence from both experimental and obser-vational studies implicates exposure to heavy metals,in a dose-response manner,in the increased risk of CVD.The limitations of most existing studies include insufficient statistical power,lack of comprehensive assessment of exposure,and cross-sectional design.Given the widespread exposure to heavy metals,an urgent need has emerged to investigate these putative associations of environmental exposures,either independently or jointly,with incident CVD outcomes prospectively in well-characterized cohorts of diverse populations,and to determine potential strategies to prevent and control the impacts of heavy metal exposure on the cardiometabolic health outcomes of individuals and populations.展开更多
Objective: Both exposure to heavy metals and alcohol intake have been related to the risk of type 2 diabetes (T2D). In this study, we aimed to assess the potential interactions between metal exposure and alcohol intak...Objective: Both exposure to heavy metals and alcohol intake have been related to the risk of type 2 diabetes (T2D). In this study, we aimed to assess the potential interactions between metal exposure and alcohol intake on the risk of T2D and prediabetes in a cohort of Chinese male workers. Methods: We conducted a cross-sectional analysis of 26,008 Chinese male workers in an occupational cohort study from 2011 to 2013. We assessed metal exposure and alcohol consumption at baseline in these workers who were aged ≥20 years. Based on occupations which were categorized according to measured urine metal levels, multiple logistic regression analyses were used to evaluate the independent and joint effects of metal and alcohol exposure on the risk of T2D and prediabetes. Results: Risks of T2D (Ptrend= 0.0 0 1 ) and prediabetes (Ptrend = 0.001) were significantly elevated with increasing number of standard drinks per week, years of drinking, and lifetime alcohol consumption. An adjusted odds ratio (OR) of 6.1 (95% confidence interval [CI]: 4.8-7.8) was observed for the smelting/refining workers (highest metal exposure levels) who had the highest lifetime alcohol consumption (>873 kg)(Pinteraction = 0.018), whereas no statistically significant joint effect was found for prediabetes (Pinteraction =0.515). Conclusions: Both exposures to metal and heavy alcohol intake were associated with the risk of diabetes in this large cohort of male workers. There was a strong interaction between these two exposures in affecting diabetes risk that needs to be confirmed in future studies.展开更多
基金support from Sichuan Science and Technology Program(21JCQN0066)supported by National Natural Science Foundation of China(No.51774249).
文摘Large-scale sand fracturing is a necessary means in the efficient exploitation of shale gas/oil.However,in the process of fracturing operation,the sand carrying fluid and proppant easily causes scouring and wear to production strings,especially the casing perforation system,which damage the wellbore integrity and deformation to affect the subsequent fracturing.For this problem,taking the actual construction conditions and perforation technology of an oilfield in western China as an example,the structural parameters of the downhole string were measured and the wall thickness reduction model of casing perforation suitable for large-displacement sand fracturing in horizontal well section was established.With software ANSYS-FLUENT,the casing perforation erosion under the conditions of different displacements,sand content and perforation sand-passing quantity in the process of sand fracturing was simulated and calculated.The influences of three parameters on perforation erosion and expansion were analyzed and the prediction chart of the influences of three main control factors on perforation erosion and expansion was established.The perforation erosion images after fracturing construction were obtained with the downhole eagle perforation logging technology.The logging chart results were compared with the downhole eagle perforation data.The error between the established numerical simulation calculation charts and the real logging data was about 5%,indicating that the simulation charts were the valuable reference.
文摘国内首台多路并联超高功率脉冲装置"聚龙一号"(PTS)已被用于磁驱动准等熵实验研究,其分时分组放电特点为开展材料的动高压可控路径加载研究提供了便利.磁驱动准等熵实验的物理设计和结果分析需要依赖可靠的数值模拟平台.本文介绍了含强度计算的一维磁流体力学程序MADE1D的物理模型和程序特点,讨论了"聚龙一号"装置两种不同电流波形驱动条件下准等熵实验的模拟情况.结果显示,MADE1D程序能够较好地反映电磁力引起的压缩波在样品内部的产生、传播及发展过程,计算获得的"样品/窗口"界面速度同实验测量结果符合较好.分析发现,电流波形是影响加载过程的重要因素.对于目前使用的带状电极,电流上升率不宜超过40 k A/ns,否则可能在厚度1.2 mm以上的铝样品中产生冲击.
基金supported by the Program from Shanghai Uni-versity of Traditional Chinese Medicine(B201725)
文摘In this study, we show that the percutaneous absorption and brain distribution of tetramethylpyrazine(TMP) is enhanced when combined with borneol(BN) in a microemulsionbased transdermal therapeutic system(ME-TTS). The formulation of the TMP and BN microemulsion(TEM-BN-ME) was optimized in skin permeation studies in vitro following a uniform experimental design. Male Sprague-Dawley rats were used for the in vivo pharmacokinetic and tissue distribution studies of TMP-BN-ME-TTS. In the pharmacokinetic study, the TMP-BN-ME-TTS treated rats had significantly higher( P < 0.05) C max and AUC of TMP than the TMP-ME-TTS treated rats, indicating that BN improves the rate and extent of TMP percutaneous absorption. In the tissue distribution study, the AUC of TMP in brain was significantly higher in the TMP-BN-ME-TTS group( P < 0.05), indicating that BN facilitates the distribution of TMP in brain. In summary, BN enhanced the percutaneous absorption and brain distribution of TMP in a microemulsion-based transdermal therapeutic system.
文摘考察以0.55 g/100 mL L-精氨酸(精氨酸)/L-赖氨酸(赖氨酸)+1.5 g/100 mL NaCl溶液为提取剂提取的鸡胸肉蛋白的凝胶特性。差示扫描量热法和动态流变结果表明:与对照组相比,添加精氨酸/赖氨酸的提取剂所对应的蛋白提取物在加热过程中具有3个明显的变性温度点和4个明显的温度区间,其在加热和冷却的过程中均具有更高的储能模量;添加精氨酸/赖氨酸的提取剂所对应的蛋白提取物形成的蛋白凝胶具有连续的三维网络结构、更高的保水性和凝胶强度以及更低的蒸煮损失。因此,提取剂中包含精氨酸/赖氨酸的蛋白提取物具有更好的凝胶特性,所形成的凝胶具有更好的保水和质构等特性。
基金supported by the Key Project of Science and Technology Department of Guizhou Province(No.ZK(2022)016)the Special Research Fund of Natural Science(Special Post)of Guizhou University(No.(2020)01)the Key Cultivation Program of Guizhou University(No.2019(08)).
文摘Antibiotic pollution has become a global eco-environmental issue.To reduce sulfonamide antibiotics in water and improve resource utilization of solid wastes,phosphogypsummodified biochar composite(PMBC)was prepared via facile one-step from distillers grains,wood chips,and phosphogypsum.The physicochemical properties of PMBCwere characterized by scanning electron microscope(SEM),Fourier transform infrared spectroscopy(FTIR),Zeta potential,X-ray diffraction(XRD),etc.The influencing factors,adsorption behaviors,and mechanisms of sulfadiazine(SD)and sulfamethazine(SMT)onto PMBC were studied by batch and fixed bed column adsorption experiments.The results showed that the removal rates of SD and SMT increased with the increase of phosphogypsum proportion,while decreased with the increase of solution pH.The maximum adsorption capacities of modified distillers grain and wood chips biochars for SD were 2.98 and 4.18 mg/g,and for SMT were 4.40 and 8.91mg/g,respectively,which was 9.0–22.3 times that of pristine biochar.Fixed bed column results demonstrated that PMBC had good adsorption capacities for SD and SMT.When the solution flow rate was 2.0 mL/min and the dosage of PMBC was 5.0 g,the removal rates of SD and SMT by modified wood chips biochar were both higher than 50%in 4 hr.The main mechanisms of SD and SMT removal by PMBC are hydrogen bonding,π-πdonor-acceptor,electrostatic interaction,and hydrophobic interaction.This study provides an effective method for the removal of antibiotics in water and the resource utilization of phosphogypsum.
基金supported by the Research Fund for the Doctoral Program of Higher Education of China(No.20114301120004)Hunan Provincial Natural Science Foundation of China(No.12JJ6081)+1 种基金Dr.’s Start-up Foundation of Xiangtan University(No.06KZjKZ08035)Natural Science Foundation of Xiangtan University(No.2011XZX09)
文摘Several derivatives have been synthesized from chrysin, diosmetin, apigenin, and luteolin, which were isolated from diverse natural plants. The a-glucosidase inhibitory activity of these compounds was evaluated. The glucosidase inhibitory activity of all derivatives(IC50< 24.396 mmol/L) was higher compared with that of the reference drug, acarbose(IC50= 563.601 40.492 mmol/L), and 1-deoxynojirimycin(IC50= 226.912 12.573 mmol/L). O30,O7-Hexyl diosmetin(IC50= 2.406 0.101 mmol/L)was the most potent inhibitor identified. These compounds showed a higher inhibitory ability compared with their precursors except the luteolin derivatives. In general, the inhibitory activity of the synthetic derivatives was enhanced with long alkyl chains at positions 30, 40 and 7 of the flavonoid.
基金This study was supported by the National Natural Science Foundation of China(Grant Number:41705122).
文摘Background and Aims:Metabolic dysfunction-associ-ated fatty liver disease(MAFLD)is a new concept,pro-posed in 2020;however,its applicability in Asia populations has yet to be evaluated.Therefore,we aimed to compare the difference in epidemiological and clinical characteris-tics between MAFLD and non-alcoholic fatty liver disease(NAFLD)among Asian populations.Methods:Based on the Jinchang cohort,30,633 participants were collected.The prevalence and incidence of MAFLD and NAFLD were used to analyze the epidemic characteristics and its overlapping effects.In addition,the corresponding clinical character-istics of the two diagnostic criteria populations were com-pared.Results:The prevalence rates of MAFLD and NAFLD were 21.03%and 18.83%,respectively.After an average 2.28-year follow-up,the incidence densities of MAFLD and NAFLD were 41.58 per 1,000 person-years and 37.69 per 1,000 person-years,respectively.With the increase of baseline age,body mass index(BMI),and waist circumfer-ence(WC)levels,the prevalence and incidence of MAFLD and NAFLD were on the rise(all ptrend<0.05).Among the total patients diagnosed at baseline or follow-up,most pa-tients had both MAFLD and NAFLD,accounting for 78.84%and 82.88%,respectively.Compared with NAFLD,MAFLD patients had greater proportions of males and metabolic diseases(diabetes,dyslipidemia),and had higher BMI,WC,liver enzymes,blood glucose,and lipid levels in the base-line diagnosis patients(p<0.05).Additionally,lean MAFLD patients had higher metabolic disorders than lean NAFLD patients(p<0.05).Conclusions:Compared with NAFLD,the newly proposed definition of MAFLD is more practical and accurate,and it can help identify more fatty liver pa-tients with high-risk diseases.
文摘Cardiovascular disease(CVD)and environmental degradation are leading global health problems of our time.Recent studies have linked exposure to heavy metals to the risks of CVD and diabetes,particularly in populations from low-and middle-income countries,where concomitant rapid development occurs.In this review,we 1)assessed the totality,quantity,and consistency of the available epidemiological studies,linking heavy metal exposures to the risk of CVD(including stroke and coronary heart disease);2)discussed the potential biological mechanisms underlying some tantalizing observations in humans;and 3)identified gaps in our knowledge base that must be investigated in future work.An accumulating body of evidence from both experimental and obser-vational studies implicates exposure to heavy metals,in a dose-response manner,in the increased risk of CVD.The limitations of most existing studies include insufficient statistical power,lack of comprehensive assessment of exposure,and cross-sectional design.Given the widespread exposure to heavy metals,an urgent need has emerged to investigate these putative associations of environmental exposures,either independently or jointly,with incident CVD outcomes prospectively in well-characterized cohorts of diverse populations,and to determine potential strategies to prevent and control the impacts of heavy metal exposure on the cardiometabolic health outcomes of individuals and populations.
基金Project of Belt and Road Special Project of Lanzhou University (20181dbrzd008)Natural Science Foundation of China (81673248)Fogarty training grants D43TW 008323 and D43TW 007864-01 from the US National Institutes of Health.
文摘Objective: Both exposure to heavy metals and alcohol intake have been related to the risk of type 2 diabetes (T2D). In this study, we aimed to assess the potential interactions between metal exposure and alcohol intake on the risk of T2D and prediabetes in a cohort of Chinese male workers. Methods: We conducted a cross-sectional analysis of 26,008 Chinese male workers in an occupational cohort study from 2011 to 2013. We assessed metal exposure and alcohol consumption at baseline in these workers who were aged ≥20 years. Based on occupations which were categorized according to measured urine metal levels, multiple logistic regression analyses were used to evaluate the independent and joint effects of metal and alcohol exposure on the risk of T2D and prediabetes. Results: Risks of T2D (Ptrend= 0.0 0 1 ) and prediabetes (Ptrend = 0.001) were significantly elevated with increasing number of standard drinks per week, years of drinking, and lifetime alcohol consumption. An adjusted odds ratio (OR) of 6.1 (95% confidence interval [CI]: 4.8-7.8) was observed for the smelting/refining workers (highest metal exposure levels) who had the highest lifetime alcohol consumption (>873 kg)(Pinteraction = 0.018), whereas no statistically significant joint effect was found for prediabetes (Pinteraction =0.515). Conclusions: Both exposures to metal and heavy alcohol intake were associated with the risk of diabetes in this large cohort of male workers. There was a strong interaction between these two exposures in affecting diabetes risk that needs to be confirmed in future studies.
