With the arrival of the big data era, the modern higher education model has undergone radical changes, and higher requirements have been put forward for the data literacy of college teachers. The paper first analyzes ...With the arrival of the big data era, the modern higher education model has undergone radical changes, and higher requirements have been put forward for the data literacy of college teachers. The paper first analyzes the connotation of teacher data literacy, and then combs through the status quo and dilemmas of teachers’ data literacy ability in applied universities. The paper proposes to enhance the data literacy ability of teachers from the perspective of organizational learning. Through building a digital culture, building a data-driven teaching environment, and constructing an interdisciplinary learning community to further promote the application of the theory and practice of datafication inside and outside the organization, and ultimately improve the quality of teaching.展开更多
Objective： The high expression of cell division cycle 42 protein （CDC42） may be involved in the occurrence and progression of several tumors. However, the expression and function of CDC42 in cervical squamous cell ...Objective： The high expression of cell division cycle 42 protein （CDC42） may be involved in the occurrence and progression of several tumors. However, the expression and function of CDC42 in cervical squamous cell carcinoma remains unclear. This study aimed to investigate the expression of CDC42 in cervical squamous cell carcinoma and its correlation with clinicopathologic characteristics. Methods： The expression of CDC42 in 162 cervical squamous cell carcinoma tissue samples and 33 normal cervical tissue samples was investigated by immunohistochemistry. The CDC42 mRNA expression was detected by reverse transcription-polymerase chain reaction （RT-PCR）. Results： The cervical squamous cell carcinoma group showed a significantly higher CDC42 positive rate, compared to the normal cervical tissues （P〈0.05）. Fttrthermore, the tissues of stage Ⅱ-Ⅳ carcinoma patients showed higher CDC42 expression levels compared to stage I patients （P=0.05）. In addition, the expression of CDC42 was not correlated to age of patients, differentiation degree of cancer cells, or lymph node metastasis （P〉0.05）. Furthermore, compare with normal cervical tissues, the CDC42 mRNA expression in cervical cancer had no significant difference. Conclusions： CDC42 was up-regulated at protein level, but not mRNA level, in cervical squamous cell carcinoma. The high expression of CDC42 was correlated to the clinical stage of the patients, indicating that CDC42 might contribute to the progression of cervical squamous cell carcinoma.展开更多
The authors regret<the wrong file for Appendix A and the mistake in Figure 3;the correct Appendix has been updated as the attachment.>The authors would like to apologize for any inconvenience caused.
A novel on-line system composed of supercritical fluid extraction(SFE), dilution line and reverse phase liquid chromatography/mass spectrometry(RPLC/MS) was constructed for on-line extraction and reverse phase separat...A novel on-line system composed of supercritical fluid extraction(SFE), dilution line and reverse phase liquid chromatography/mass spectrometry(RPLC/MS) was constructed for on-line extraction and reverse phase separation of some fat-soluble components in foods. Three columns including a trap column,concentration column and analytical column were used for trapping the fat-soluble components, on-line enrichment and reverse phase separation, respectively. Capsaicinoids were on-line extracted by a CO_2 supercritical fluid, then concentrated and separated by using the C_(18) columns, finally detected by mass spectrometry(MS). Capsaicin eluted at 10.1 min and limit of detection(LOD, S/N=3) for the standard solution is 0.55pg. The linearity was calculated with a value of coefficient of determination(R^2)≥0.998 in the range of 1.1–8.5 ng. Concentrations of capsaicin in the green, yellow, and red bell peppers were determined to be 60.33 ng/g, 31.79 ng/g, 35.38ng/g, respectively.展开更多
Zinc(Zn)has been shown to attenuate the adverse effects of heat stress on broilers,but the mechanisms involving this process remain unclear.We aimed to investigate possible protective mechanisms of Zn on primary cultu...Zinc(Zn)has been shown to attenuate the adverse effects of heat stress on broilers,but the mechanisms involving this process remain unclear.We aimed to investigate possible protective mechanisms of Zn on primary cultured hepatocytes of broiler embryos subjected to heat stress.Three experiments were conducted.In Exp.1,hepatocytes were treated with 0,50,100,200,or 400μmol/L added Zn as inorganic Zn sulfate(iZn)for 12,24 or 48 h.In Exp.2,cells were exposed to 40℃(a normal temperature[NT])and 44℃(a high temperature[HT])for 1,2,4,6,or 8 h.In Exp.3,cells were preincubated with 0 or 50μmol/L Zn as iZn or organic Zn lysine chelate(oZn)for 8 h under NT,and then incubated with the same Zn treatments under NT or HT for 4 or 6 h.The biomarkers of antioxidative status and heat stress in cells were measured.The results in Exp.1 indicated that 50μmol/L Zn and 12 h incubation were the optimal conditions for increasing antioxidant ability of hepatocytes.In Exp.2,the 4 or 6 h incubation under HT was effective in inducing heat shock responses of hepatocytes.In Exp.3,HT elevated(P<0.01)malondialdehyde content and expressions of heat shock protein 70(HSP70)mRNA and protein,as well as HSP90 mRNA.However,Zn supplementation increased(P<0.05)copper zinc superoxide dismutase(CuZnSOD)activity and metallothionein mRNA expression,and effectively decreased(P<0.05)the ex-pressions of HSP70 mRNA and protein,as well as HSP90 mRNA.Furthermore,oZn was more effective(P<0.05)than iZn in enhancing CuZnSOD activity of hepatocytes under HT.It was concluded that Zn(especially oZn)could alleviate heat stress of broiler hepatocytes via enhancing their antioxidant ability and attenuating heat shock responses.展开更多
The current NRC dietary selenium(Se)requirement(0.15 mg/kg)of broilers is primarily based on growth performance data reported in 1986.Our study aimed to determine optimal dietary Se levels of broilers fed a practical ...The current NRC dietary selenium(Se)requirement(0.15 mg/kg)of broilers is primarily based on growth performance data reported in 1986.Our study aimed to determine optimal dietary Se levels of broilers fed a practical corn-soybean meal diet for the full expression of selenoproteins in various tissues.A total of 384 one-d-old male broilers(n=8 replicates/diet)were fed a basal corn-soybean meal diet or the basal diet supplemented with 0.1,0.2,0.3,0.4 or 0.5 mg Se/kg in the form of Na_(2)SeO_(3) for 21 d.Regression analysis was conducted to evaluate the optimal dietary Se levels using broken-line,quadratic or asymptotic models.The activity of glutathione peroxidase(GPX)in the plasma,liver,kidney and pancreas,iodothyronine deiodinase(DIO)in the plasma,liver and pancreas,and thioredoxin reductase(Txnrd)in the liver and pancreas,the mRNA levels of Gpx1,Gpx4,Dio1,selenoprotein(Seleno)h,Selenop and Selenou in the liver,Gpx4,Dio1,Txnrd1,Txnrd2,Selenoh,Selenop and Selenou in the kidney,and Gpx1,Gpx4,Selenoh and Selenou in the pancreas,and the protein levels of GPX4 in the liver and kidney of broilers were influenced(P<0.05)by added Se levels,and increased quadratically(P<0.05)with the increase of added Se levels.The estimates of optimal dietary Se levels were 0.07 to 0.36 mg/kg based on the fitted broken-line,quadratic or asymptotic models(P<0.001)of the aforementioned selenoprotein expression in the plasma,liver and kidney,and 0.09 to 0.46 mg/kg based on the fitted broken-line models(P<0.001)of the aforementioned selenoprotein expression in the pancreas.The results indicate that the optimal dietary Se levels would be 0.36 mg/kg to support the full expression of selenoproteins in the plasma,liver and kidney,and 0.46 mg/kg to support the full expression of selenoproteins in the pancreas of broilers fed a practical corn-soybean meal diet from 1 to 21 d of age.展开更多
To prevent the deposition of natural gas hydrate in deepwater gas well,the hydrate formation area in wellbore must be predicted.Herein,by comparing four prediction methods of temperature in pipe with field data and co...To prevent the deposition of natural gas hydrate in deepwater gas well,the hydrate formation area in wellbore must be predicted.Herein,by comparing four prediction methods of temperature in pipe with field data and comparing five prediction methods of hydrate formation with experiment data,a method based on OLGA&PVTsim for predicting the hydrate formation area in wellbore was proposed.Meanwhile,The hydrate formation under the conditions of steady production,throttling and shut-in was predicted by using this method based on a well data in the South China Sea.The results indicate that the hydrate formation area decreases with the increase of gas production,inhibitor concentrations and the thickness of insulation materials and increases with the increase of thermal conductivity of insulation materials and shutdown time.Throttling effect causes a plunge in temperature and pressure in wellbore,thus leading to an increase of hydrate formation area.展开更多
A simple and efficient dithizone-functionalized solid-phase extraction(SPE)procedure,online coupled with high-performance liquid chromatography(HPLC)-inductively coupled plasma mass spectrometry,was developed for the ...A simple and efficient dithizone-functionalized solid-phase extraction(SPE)procedure,online coupled with high-performance liquid chromatography(HPLC)-inductively coupled plasma mass spectrometry,was developed for the first time for enrichment and determination of ultra-trace mercury(Hg)species(inorganic divalent Hg(Hg(Ⅱ)),methylmercury(CH_(3)Hg(Ⅱ))and ethylmercury(C_(2)H_(5)Hg(Ⅱ))in cereals and environmental samples.In the proposed method,functionalization of the commercial C_(18) column with dithizone,enrichment,and elution of the above Hg species can be completed online with the developed SPE device.A simple solution of 2-mercaptoethanol(1%(V/V))could be used as an eluent for both the SPE and HPLC separation of Hg species,significantly simplifying the method and instrumen-tation.The online SPE method was optimized by varying dithizone dose,2-mercaptoethanol concentration,and sample volume.In addition,the effect of pH,coexisting interfering ions,and salt effect on the enrichment was also discussed.Under the optimized conditions,the detection limits of Hg species for 5 mL water sample were 0.15 ng/L for Hg(Ⅱ),0.07 ng/L for CH_(3)Hg(Ⅱ),and 0.04 ng/L for C_(2)H_(5)Hg(Ⅱ)with recoveries in the range of 85%-100%.The developed dithizone-functionalized C_(18) SPE column can be reused after a single function-alization,which significantly simplifies the enrichment step.Moreover,the stability of Hg species enriched on the SPE column demonstrated its suitability for field sampling of Hg species for later laboratory analysis.This environment-friendly method offers a robust tool to detect ultra-trace Hg species in cereals and environmental samples.展开更多
Taking the e-commerce platform’s fairness concern into account,three decision-making models of e-commerce closed-loop supply chain are constructed.Then,the recycling decisions under three models are studied and the i...Taking the e-commerce platform’s fairness concern into account,three decision-making models of e-commerce closed-loop supply chain are constructed.Then,the recycling decisions under three models are studied and the impact of fairness concern is analysed.The‘effort costs sharing contract’is proposed to realise the coordination of the supply chain.Finally,the conclusions are verified by numerical analysis.The results show that the e-commerce platform’s fairness concern reduces own profit and the remanufacturer’s profit,and decreases system efficiency.The‘effort costs sharing contract’can realise the centralised model where recycling price of waste products is the highest,commission is the lowest,and system profit is the highest.In the coordinated system,the higher the proportion of remanufacturer sharing effort costs,the higher the profit of remanufacturer.展开更多
文摘With the arrival of the big data era, the modern higher education model has undergone radical changes, and higher requirements have been put forward for the data literacy of college teachers. The paper first analyzes the connotation of teacher data literacy, and then combs through the status quo and dilemmas of teachers’ data literacy ability in applied universities. The paper proposes to enhance the data literacy ability of teachers from the perspective of organizational learning. Through building a digital culture, building a data-driven teaching environment, and constructing an interdisciplinary learning community to further promote the application of the theory and practice of datafication inside and outside the organization, and ultimately improve the quality of teaching.
基金supported by the National Natural Science Foundation of China(No.11072006,No.10772007 and No.81070078)National Basic Research Program of China(973 Program,2013CB933702)
文摘Objective： The high expression of cell division cycle 42 protein （CDC42） may be involved in the occurrence and progression of several tumors. However, the expression and function of CDC42 in cervical squamous cell carcinoma remains unclear. This study aimed to investigate the expression of CDC42 in cervical squamous cell carcinoma and its correlation with clinicopathologic characteristics. Methods： The expression of CDC42 in 162 cervical squamous cell carcinoma tissue samples and 33 normal cervical tissue samples was investigated by immunohistochemistry. The CDC42 mRNA expression was detected by reverse transcription-polymerase chain reaction （RT-PCR）. Results： The cervical squamous cell carcinoma group showed a significantly higher CDC42 positive rate, compared to the normal cervical tissues （P〈0.05）. Fttrthermore, the tissues of stage Ⅱ-Ⅳ carcinoma patients showed higher CDC42 expression levels compared to stage I patients （P=0.05）. In addition, the expression of CDC42 was not correlated to age of patients, differentiation degree of cancer cells, or lymph node metastasis （P〉0.05）. Furthermore, compare with normal cervical tissues, the CDC42 mRNA expression in cervical cancer had no significant difference. Conclusions： CDC42 was up-regulated at protein level, but not mRNA level, in cervical squamous cell carcinoma. The high expression of CDC42 was correlated to the clinical stage of the patients, indicating that CDC42 might contribute to the progression of cervical squamous cell carcinoma.
文摘The authors regret<the wrong file for Appendix A and the mistake in Figure 3;the correct Appendix has been updated as the attachment.>The authors would like to apologize for any inconvenience caused.
基金supported by the National Natural Science Foundation of China (No. 21621003)
文摘A novel on-line system composed of supercritical fluid extraction(SFE), dilution line and reverse phase liquid chromatography/mass spectrometry(RPLC/MS) was constructed for on-line extraction and reverse phase separation of some fat-soluble components in foods. Three columns including a trap column,concentration column and analytical column were used for trapping the fat-soluble components, on-line enrichment and reverse phase separation, respectively. Capsaicinoids were on-line extracted by a CO_2 supercritical fluid, then concentrated and separated by using the C_(18) columns, finally detected by mass spectrometry(MS). Capsaicin eluted at 10.1 min and limit of detection(LOD, S/N=3) for the standard solution is 0.55pg. The linearity was calculated with a value of coefficient of determination(R^2)≥0.998 in the range of 1.1–8.5 ng. Concentrations of capsaicin in the green, yellow, and red bell peppers were determined to be 60.33 ng/g, 31.79 ng/g, 35.38ng/g, respectively.
基金supported by the Key International Cooperation Program of the National Natural Science Foundation of China(project no.31110103916,Beijing,China)the National Natural Science Foundation of China(project no.31972583,Beijing,China)+1 种基金the China Agricultural Research System(project no.CARS-41,Beijing,China)the Agricultural Science and Technology Innovation Program(ASTIP-IAS09,Beijing,China)
文摘Zinc(Zn)has been shown to attenuate the adverse effects of heat stress on broilers,but the mechanisms involving this process remain unclear.We aimed to investigate possible protective mechanisms of Zn on primary cultured hepatocytes of broiler embryos subjected to heat stress.Three experiments were conducted.In Exp.1,hepatocytes were treated with 0,50,100,200,or 400μmol/L added Zn as inorganic Zn sulfate(iZn)for 12,24 or 48 h.In Exp.2,cells were exposed to 40℃(a normal temperature[NT])and 44℃(a high temperature[HT])for 1,2,4,6,or 8 h.In Exp.3,cells were preincubated with 0 or 50μmol/L Zn as iZn or organic Zn lysine chelate(oZn)for 8 h under NT,and then incubated with the same Zn treatments under NT or HT for 4 or 6 h.The biomarkers of antioxidative status and heat stress in cells were measured.The results in Exp.1 indicated that 50μmol/L Zn and 12 h incubation were the optimal conditions for increasing antioxidant ability of hepatocytes.In Exp.2,the 4 or 6 h incubation under HT was effective in inducing heat shock responses of hepatocytes.In Exp.3,HT elevated(P<0.01)malondialdehyde content and expressions of heat shock protein 70(HSP70)mRNA and protein,as well as HSP90 mRNA.However,Zn supplementation increased(P<0.05)copper zinc superoxide dismutase(CuZnSOD)activity and metallothionein mRNA expression,and effectively decreased(P<0.05)the ex-pressions of HSP70 mRNA and protein,as well as HSP90 mRNA.Furthermore,oZn was more effective(P<0.05)than iZn in enhancing CuZnSOD activity of hepatocytes under HT.It was concluded that Zn(especially oZn)could alleviate heat stress of broiler hepatocytes via enhancing their antioxidant ability and attenuating heat shock responses.
基金supported by the National Natural Science Foundation of China(project no.31601956)the Agricultural Science and Technology Innovation Program(project no.ASTIPIAS09)the China Agriculture Research System of MOF and MARA(project no.CARS-41)。
文摘The current NRC dietary selenium(Se)requirement(0.15 mg/kg)of broilers is primarily based on growth performance data reported in 1986.Our study aimed to determine optimal dietary Se levels of broilers fed a practical corn-soybean meal diet for the full expression of selenoproteins in various tissues.A total of 384 one-d-old male broilers(n=8 replicates/diet)were fed a basal corn-soybean meal diet or the basal diet supplemented with 0.1,0.2,0.3,0.4 or 0.5 mg Se/kg in the form of Na_(2)SeO_(3) for 21 d.Regression analysis was conducted to evaluate the optimal dietary Se levels using broken-line,quadratic or asymptotic models.The activity of glutathione peroxidase(GPX)in the plasma,liver,kidney and pancreas,iodothyronine deiodinase(DIO)in the plasma,liver and pancreas,and thioredoxin reductase(Txnrd)in the liver and pancreas,the mRNA levels of Gpx1,Gpx4,Dio1,selenoprotein(Seleno)h,Selenop and Selenou in the liver,Gpx4,Dio1,Txnrd1,Txnrd2,Selenoh,Selenop and Selenou in the kidney,and Gpx1,Gpx4,Selenoh and Selenou in the pancreas,and the protein levels of GPX4 in the liver and kidney of broilers were influenced(P<0.05)by added Se levels,and increased quadratically(P<0.05)with the increase of added Se levels.The estimates of optimal dietary Se levels were 0.07 to 0.36 mg/kg based on the fitted broken-line,quadratic or asymptotic models(P<0.001)of the aforementioned selenoprotein expression in the plasma,liver and kidney,and 0.09 to 0.46 mg/kg based on the fitted broken-line models(P<0.001)of the aforementioned selenoprotein expression in the pancreas.The results indicate that the optimal dietary Se levels would be 0.36 mg/kg to support the full expression of selenoproteins in the plasma,liver and kidney,and 0.46 mg/kg to support the full expression of selenoproteins in the pancreas of broilers fed a practical corn-soybean meal diet from 1 to 21 d of age.
文摘To prevent the deposition of natural gas hydrate in deepwater gas well,the hydrate formation area in wellbore must be predicted.Herein,by comparing four prediction methods of temperature in pipe with field data and comparing five prediction methods of hydrate formation with experiment data,a method based on OLGA&PVTsim for predicting the hydrate formation area in wellbore was proposed.Meanwhile,The hydrate formation under the conditions of steady production,throttling and shut-in was predicted by using this method based on a well data in the South China Sea.The results indicate that the hydrate formation area decreases with the increase of gas production,inhibitor concentrations and the thickness of insulation materials and increases with the increase of thermal conductivity of insulation materials and shutdown time.Throttling effect causes a plunge in temperature and pressure in wellbore,thus leading to an increase of hydrate formation area.
基金This work was supported by the National Key Research and Development Project(No.2020YFA0907400)the National Natural Science Foundation of China(Nos.21777178,21976193)+1 种基金Y.Yin acknowledges the supports from the National Young Top-Notch Talents(No.W03070030)the Youth Innovation Promotion Association of the Chinese Academy of Sciences(No.Y202011).
文摘A simple and efficient dithizone-functionalized solid-phase extraction(SPE)procedure,online coupled with high-performance liquid chromatography(HPLC)-inductively coupled plasma mass spectrometry,was developed for the first time for enrichment and determination of ultra-trace mercury(Hg)species(inorganic divalent Hg(Hg(Ⅱ)),methylmercury(CH_(3)Hg(Ⅱ))and ethylmercury(C_(2)H_(5)Hg(Ⅱ))in cereals and environmental samples.In the proposed method,functionalization of the commercial C_(18) column with dithizone,enrichment,and elution of the above Hg species can be completed online with the developed SPE device.A simple solution of 2-mercaptoethanol(1%(V/V))could be used as an eluent for both the SPE and HPLC separation of Hg species,significantly simplifying the method and instrumen-tation.The online SPE method was optimized by varying dithizone dose,2-mercaptoethanol concentration,and sample volume.In addition,the effect of pH,coexisting interfering ions,and salt effect on the enrichment was also discussed.Under the optimized conditions,the detection limits of Hg species for 5 mL water sample were 0.15 ng/L for Hg(Ⅱ),0.07 ng/L for CH_(3)Hg(Ⅱ),and 0.04 ng/L for C_(2)H_(5)Hg(Ⅱ)with recoveries in the range of 85%-100%.The developed dithizone-functionalized C_(18) SPE column can be reused after a single function-alization,which significantly simplifies the enrichment step.Moreover,the stability of Hg species enriched on the SPE column demonstrated its suitability for field sampling of Hg species for later laboratory analysis.This environment-friendly method offers a robust tool to detect ultra-trace Hg species in cereals and environmental samples.
基金supported by the National Natural Science Foundation of China[grant number 71971129],[grant number 71501111]A Project of Shandong Province Higher Educational Science and Technology Program[grant number 2019RWG017].
文摘Taking the e-commerce platform’s fairness concern into account,three decision-making models of e-commerce closed-loop supply chain are constructed.Then,the recycling decisions under three models are studied and the impact of fairness concern is analysed.The‘effort costs sharing contract’is proposed to realise the coordination of the supply chain.Finally,the conclusions are verified by numerical analysis.The results show that the e-commerce platform’s fairness concern reduces own profit and the remanufacturer’s profit,and decreases system efficiency.The‘effort costs sharing contract’can realise the centralised model where recycling price of waste products is the highest,commission is the lowest,and system profit is the highest.In the coordinated system,the higher the proportion of remanufacturer sharing effort costs,the higher the profit of remanufacturer.
