Background:SMAD family proteins(SMADs)are crucial transcription factors downstream of transforming growth factor beta(TGF-ß)/SMAD signaling pathways that have been reported to play a pivotal role in mammalian rep...Background:SMAD family proteins(SMADs)are crucial transcription factors downstream of transforming growth factor beta(TGF-ß)/SMAD signaling pathways that have been reported to play a pivotal role in mammalian reproduction.However,the role of SMAD family member 8(SMAD8,also known as SMAD9),a member of the SMAD family,in mammalian reproduction remains unclear.Methods:We employed RNA interference techniques to knock down Smad8 expression in mouse granulosa cells(GCs)to investigate the effects of Smad8 on GC growth and steroidogenesis.Results:Our findings revealed a significant decrease in the proliferative capacity and a substantial increase in the apoptosis rate of GCs after transfection with Smad8-siRNA for 48 h.Subsequent hormone assays demonstrated a significant decrease in estradiol(E2)levels,whereas progesterone(P4)remained unchanged.Further mechanistic analysis showed that the mRNA expression of proliferating cell nuclear antigen(Pcna),Cyclin D2,cell cycle-dependent kinase 4(Cdk4),B-cell lymphoma-2(Bcl-2),estrogen receptor(Er),luteinizing hormone receptor(Lhr)and cytochrome P450 family 19 subfamily A member 1(Cyp19a1)significantly decreased.Conversely,the mRNA of cysteine aspartate proteinase 3(Caspase 3)significantly increased,wheras Bcl2-associated X(Bax),folliclestimulating hormone receptor(Fshr)and cytochrome P450 family 11 subfamily A member 1(Cyp11a1)remained unchanged compared to the controls.Conclusion:This study indicates that Smad8 knockdown inhibits cell proliferation,promotes apoptosis,reduces Er and Lhr transcription,and decreases E2 production in mouse GCs.These findings suggest that Smad8 may serve as a novel genetic marker for mammalian reproduction.展开更多
The high throughput prediction of the thermodynamic phase behavior of active pharmaceutical ingredients(APIs)with pharmaceutically relevant excipients remains a major scientific challenge in the screening of pharmaceu...The high throughput prediction of the thermodynamic phase behavior of active pharmaceutical ingredients(APIs)with pharmaceutically relevant excipients remains a major scientific challenge in the screening of pharmaceutical formulations.In this work,a developed machine-learning model efficiently predicts the solubility of APIs in polymers by learning the phase equilibrium principle and using a few molecular descriptors.Under the few-shot learning framework,thermodynamic theory(perturbed-chain statistical associating fluid theory)was used for data augmentation,and computational chemistry was applied for molecular descriptors'screening.The results showed that the developed machine-learning model can predict the API-polymer phase diagram accurately,broaden the solubility data of APIs in polymers,and reproduce the relationship between API solubility and the interaction mechanisms between API and polymer successfully,which provided efficient guidance for the development of pharmaceutical formulations.展开更多
To improve the stability of nanoparticles in aqueous solution,polymer or surfactant,etc.are often added in solutions during the preparation process of nanoparticles,which can induce new interfaces that influence the s...To improve the stability of nanoparticles in aqueous solution,polymer or surfactant,etc.are often added in solutions during the preparation process of nanoparticles,which can induce new interfaces that influence the solubility of nanoparticles.In this work,a novel interfacial thermodynamic model for describing the Gibbs energy of the nanoparticles coated by stabilizers was proposed to predict the solubility of nanoparticles.Within the developed model,the activity coefficient of nano metal system was determined by Davies model and that of nano drug system by Perturbed-Chain Statistical Associating Fluid Theory(PC-SAFT).The Gibbs energy of the interface was established as a function of molecular parameters via the application for nano metal system.Furthermore,the model was further used to predict the solubility of nano drugs itraconazole,fenofibrate,and griseofulvin.It was found that the Gibbs energy of the interface plays an important role especially when the radius of nano metal is less than 40 nm,and the developed model can predict the solubility of nano drug with high accuracy in comparison with the experimental data as well as predict the changing trend of solubility of nano drugs that increases as the particle size decreases.Meanwhile,the stabilization mechanism of stabilizers on nano drugs was studied which provided theoretical guidance for the selection of polymer or surfactant stabilizer.These findings showed that the developed model can provide a reliable prediction of the solubility of nanoparticles and help to comprehend the stabilization mechanism of the stabilizers on nano drugs with different particle sizes,which is expected to provide important information for the design of nano drugs formulations.展开更多
[Objectives]This study was conducted to effectively monitor PGR residues in bean sprouts to provide guarantee for the food safety of agricultural products.[Methods]A high-performance liquid chromatography-tandem mass ...[Objectives]This study was conducted to effectively monitor PGR residues in bean sprouts to provide guarantee for the food safety of agricultural products.[Methods]A high-performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS)method for the determination of residues of 15 plant growth regulators(PGRs)in bean sprouts was established using bean sprouts as an experimental material.Samples were extracted with a solution containing 5%acetic acid-acetonitrile(1∶99,V/V),purified with anhydrous magnesium sulfate,and diluted with methanol solvent to constant volume.The solutions were filtered through 0.22μm filtering membrane and the target analytes were separated on a Phenomenex H18 column.The identification of each compound was established by retention time matching along with the accurate mass measurement of the precursor ions and their main fragment ions.The quantification was carried out using matrix-matched external standard method.[Results]The retention time of the 15 PGRs were found in the range from 5.8-11.7 min under the optimized conditions.The linear relation was good in the concentration range of 0.005-0.050μg/ml,and the correlation coefficients of the 15 PGRs were≥0.9990.The limits of detection were in the range of 0.03-0.92 g/kg,and the limits of quantification were in the range of 0.50-2.10μg/kg.The average recovery in the recovery test at 3 concentration levels was 80%-110%,and the relative standard deviations were in the range of 2.8%-7.5%.[Conclusions]This method is simple and accurate,and can quickly qualitatively and quantitatively analyze the residues of 15 PGRs in bean sprouts.The proposed procedure was simple,quick and accurate for the simultaneous determination of the 15 PGRs in bean sprout.展开更多
[Objectives]This study was conducted to investigate the differences of main nutrient components in 29 different varieties of Chinese chestnut.[Methods]The protein contents,starch contents,Vc contents,soluble sugar con...[Objectives]This study was conducted to investigate the differences of main nutrient components in 29 different varieties of Chinese chestnut.[Methods]The protein contents,starch contents,Vc contents,soluble sugar contents and inorganic element contents in the 29 different varieties of Chinese chestnut in the north were detected and compared.[Results]The main nutrient components in the 29 varieties of Chinese chestnut were as follows:amylose content 47.16%-63.27%,protein content 3.23%-7.58%,soluble sugar content 7.23%-16.17%,Vc content 2.42-9.42 mg/100 g,Fe content 7.20-17.28 mg/kg,K content 3611-8940 mg/kg,Zn content 4.43-9.24 mg/kg,Ca content 120-304 mg/kg,and P content 752-1658 mg/kg.In general,four varieties,"Dabanhong","Yanbao","Duanzhi"and"Jinhua",have higher nutritional components.[Conclusions]This study provides a theoretical basis for the processing,utilization,storage,purchase,breeding and scientific management of Chinese chestnut in the future.展开更多
Resveratrol is a ployphenolic compound which has a wide variety of pharmacological activity. This paper reviewed the physicochemical properties of resveratrol and its purification technology including macroporous resi...Resveratrol is a ployphenolic compound which has a wide variety of pharmacological activity. This paper reviewed the physicochemical properties of resveratrol and its purification technology including macroporous resin method, high-speed countercurrent chromatography method, molecular imprinting method, membrane separation method, column chromatography method, two-aqueous phase extraction method and the combination of purification methods, so as to provide certain reference for further research and development.展开更多
Excessive temperature rise during the operation of the generator system can affect the safety and life cycle of the machine.Therefore,in order to accurately obtain the internal temperature of the switched reluctance g...Excessive temperature rise during the operation of the generator system can affect the safety and life cycle of the machine.Therefore,in order to accurately obtain the internal temperature of the switched reluctance generator(SRG),an internal temperature estimation model based on electric heating is established in this paper.First,an im-proved variable coefficient Bertotti loss separation calcula-tion formula is adopted to solve the iron loss of the genera-tor under various operating conditions.Subsequently,the accurate heat source parameters in the temperature model can be obtained,and the corresponding heat source data can be calculated.Then,based on the obtained heat source data,an equivalent thermal circuit model is established for SRG.Meanwhile,in order to effectively reduce the internal temperature during SRG operation,a new water-cooled structure for direct cooling of SRG stator windings is pro-posed in this paper,which can effectively reduce the tem-perature rise during operation,thus improving the reliabil-ity of the generator.Finally,by comparing the equivalent thermal circuit model,finite element thermal model,and experimental temperature measurements of SRG,it is found that results from the equivalent thermal circuit model of the SRG are closer to the measured temperatures,while the effectiveness of the water-cooled structure is verified.展开更多
Skills are the foundation on which to build a strong nation,and also the foundation on which to start one's career.Xi Jinping,General Secretary of the Communist Party of China(CPC)Central Committee,has called for ...Skills are the foundation on which to build a strong nation,and also the foundation on which to start one's career.Xi Jinping,General Secretary of the Communist Party of China(CPC)Central Committee,has called for the promotion of the spirit of craftsmanship throughout society,and for the encouragement of young people to become highly skilled talents who serve China with their skills.When delivering his report to the 20th CPC National Congress,on October 16,2022,Xi Jinping said,"We will speed up efforts to build a contingent of personnel with expertise of strategic importance and cultivate greater numbers of master scholars,science strategists,first-class scientists and innovation teams,young scientists,outstanding engineers,master craftsmen,and highly skilled workers."展开更多
Beijing Overseas Cultural Exchanges Center has created an online roadmap of the Cultural Tour of Peking Opera,which highlights Peking Opera theaters,former residences of Peking Opera artists,guild halls and other plac...Beijing Overseas Cultural Exchanges Center has created an online roadmap of the Cultural Tour of Peking Opera,which highlights Peking Opera theaters,former residences of Peking Opera artists,guild halls and other places used for Peking Opera performances.The center advocates low-carbon travel,and it recommends a cycling route of the Cultural Tour of Peking Opera.While cycling along the streets of Beijing,people can visit landmark buildings of the Peking Opera,and they can feel the unique charm of the city.展开更多
Women have become an important force in promoting scientific and technological advancement globally.Many women scientists,worldwide,have created“miracles”that have greatly promoted the development of human civilizat...Women have become an important force in promoting scientific and technological advancement globally.Many women scientists,worldwide,have created“miracles”that have greatly promoted the development of human civilization.展开更多
基金supported by the High-Level Talent Research Start-Up Funds of West Anhui University(No.WGKQ2021031)Key Project of Natural Science Foundation of Anhui Province of China(No.2108085QC136)+2 种基金Key Project of Quality Engineering in Higher Education Institutions of Anhui Province(No.2020jyxm2128)National College Student Innovation and Entrepreneurship Training Program(No.202110370093)Innovation and Entrepreneurship Training Program for College Students of Anhui Province(No.S202010376114).
文摘Background:SMAD family proteins(SMADs)are crucial transcription factors downstream of transforming growth factor beta(TGF-ß)/SMAD signaling pathways that have been reported to play a pivotal role in mammalian reproduction.However,the role of SMAD family member 8(SMAD8,also known as SMAD9),a member of the SMAD family,in mammalian reproduction remains unclear.Methods:We employed RNA interference techniques to knock down Smad8 expression in mouse granulosa cells(GCs)to investigate the effects of Smad8 on GC growth and steroidogenesis.Results:Our findings revealed a significant decrease in the proliferative capacity and a substantial increase in the apoptosis rate of GCs after transfection with Smad8-siRNA for 48 h.Subsequent hormone assays demonstrated a significant decrease in estradiol(E2)levels,whereas progesterone(P4)remained unchanged.Further mechanistic analysis showed that the mRNA expression of proliferating cell nuclear antigen(Pcna),Cyclin D2,cell cycle-dependent kinase 4(Cdk4),B-cell lymphoma-2(Bcl-2),estrogen receptor(Er),luteinizing hormone receptor(Lhr)and cytochrome P450 family 19 subfamily A member 1(Cyp19a1)significantly decreased.Conversely,the mRNA of cysteine aspartate proteinase 3(Caspase 3)significantly increased,wheras Bcl2-associated X(Bax),folliclestimulating hormone receptor(Fshr)and cytochrome P450 family 11 subfamily A member 1(Cyp11a1)remained unchanged compared to the controls.Conclusion:This study indicates that Smad8 knockdown inhibits cell proliferation,promotes apoptosis,reduces Er and Lhr transcription,and decreases E2 production in mouse GCs.These findings suggest that Smad8 may serve as a novel genetic marker for mammalian reproduction.
基金the financial support from the National Natural Science Foundation of China(22278070,21978047,21776046)。
文摘The high throughput prediction of the thermodynamic phase behavior of active pharmaceutical ingredients(APIs)with pharmaceutically relevant excipients remains a major scientific challenge in the screening of pharmaceutical formulations.In this work,a developed machine-learning model efficiently predicts the solubility of APIs in polymers by learning the phase equilibrium principle and using a few molecular descriptors.Under the few-shot learning framework,thermodynamic theory(perturbed-chain statistical associating fluid theory)was used for data augmentation,and computational chemistry was applied for molecular descriptors'screening.The results showed that the developed machine-learning model can predict the API-polymer phase diagram accurately,broaden the solubility data of APIs in polymers,and reproduce the relationship between API solubility and the interaction mechanisms between API and polymer successfully,which provided efficient guidance for the development of pharmaceutical formulations.
基金funding from the National Natural Science Foundation of China(21776046,21978047)the Fundamental Research Funds for the Central Universities(2242020K40033)the Six Talent Peaks Project in Jiangsu Province(XCL-079)。
文摘To improve the stability of nanoparticles in aqueous solution,polymer or surfactant,etc.are often added in solutions during the preparation process of nanoparticles,which can induce new interfaces that influence the solubility of nanoparticles.In this work,a novel interfacial thermodynamic model for describing the Gibbs energy of the nanoparticles coated by stabilizers was proposed to predict the solubility of nanoparticles.Within the developed model,the activity coefficient of nano metal system was determined by Davies model and that of nano drug system by Perturbed-Chain Statistical Associating Fluid Theory(PC-SAFT).The Gibbs energy of the interface was established as a function of molecular parameters via the application for nano metal system.Furthermore,the model was further used to predict the solubility of nano drugs itraconazole,fenofibrate,and griseofulvin.It was found that the Gibbs energy of the interface plays an important role especially when the radius of nano metal is less than 40 nm,and the developed model can predict the solubility of nano drug with high accuracy in comparison with the experimental data as well as predict the changing trend of solubility of nano drugs that increases as the particle size decreases.Meanwhile,the stabilization mechanism of stabilizers on nano drugs was studied which provided theoretical guidance for the selection of polymer or surfactant stabilizer.These findings showed that the developed model can provide a reliable prediction of the solubility of nanoparticles and help to comprehend the stabilization mechanism of the stabilizers on nano drugs with different particle sizes,which is expected to provide important information for the design of nano drugs formulations.
基金Supported by Research Projects Funded by Talent Project Training Funds in Hebei Province(A201901128)Key R&D Project of Tangshan City(20150210C).
文摘[Objectives]This study was conducted to effectively monitor PGR residues in bean sprouts to provide guarantee for the food safety of agricultural products.[Methods]A high-performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS)method for the determination of residues of 15 plant growth regulators(PGRs)in bean sprouts was established using bean sprouts as an experimental material.Samples were extracted with a solution containing 5%acetic acid-acetonitrile(1∶99,V/V),purified with anhydrous magnesium sulfate,and diluted with methanol solvent to constant volume.The solutions were filtered through 0.22μm filtering membrane and the target analytes were separated on a Phenomenex H18 column.The identification of each compound was established by retention time matching along with the accurate mass measurement of the precursor ions and their main fragment ions.The quantification was carried out using matrix-matched external standard method.[Results]The retention time of the 15 PGRs were found in the range from 5.8-11.7 min under the optimized conditions.The linear relation was good in the concentration range of 0.005-0.050μg/ml,and the correlation coefficients of the 15 PGRs were≥0.9990.The limits of detection were in the range of 0.03-0.92 g/kg,and the limits of quantification were in the range of 0.50-2.10μg/kg.The average recovery in the recovery test at 3 concentration levels was 80%-110%,and the relative standard deviations were in the range of 2.8%-7.5%.[Conclusions]This method is simple and accurate,and can quickly qualitatively and quantitatively analyze the residues of 15 PGRs in bean sprouts.The proposed procedure was simple,quick and accurate for the simultaneous determination of the 15 PGRs in bean sprout.
基金Supported by Hebei Talent Project Training Fund(A201901128).
文摘[Objectives]This study was conducted to investigate the differences of main nutrient components in 29 different varieties of Chinese chestnut.[Methods]The protein contents,starch contents,Vc contents,soluble sugar contents and inorganic element contents in the 29 different varieties of Chinese chestnut in the north were detected and compared.[Results]The main nutrient components in the 29 varieties of Chinese chestnut were as follows:amylose content 47.16%-63.27%,protein content 3.23%-7.58%,soluble sugar content 7.23%-16.17%,Vc content 2.42-9.42 mg/100 g,Fe content 7.20-17.28 mg/kg,K content 3611-8940 mg/kg,Zn content 4.43-9.24 mg/kg,Ca content 120-304 mg/kg,and P content 752-1658 mg/kg.In general,four varieties,"Dabanhong","Yanbao","Duanzhi"and"Jinhua",have higher nutritional components.[Conclusions]This study provides a theoretical basis for the processing,utilization,storage,purchase,breeding and scientific management of Chinese chestnut in the future.
基金Supported by Hebei Provincial PhaseⅡModern Agricultural Industry Technology System Innovation Team Construction Project(HBCT2018120207)Tangshan Science and Technology Planning Project(19150204E)Hebei Province Innovation Ability Promotion Plan Project(20567673H)。
文摘Resveratrol is a ployphenolic compound which has a wide variety of pharmacological activity. This paper reviewed the physicochemical properties of resveratrol and its purification technology including macroporous resin method, high-speed countercurrent chromatography method, molecular imprinting method, membrane separation method, column chromatography method, two-aqueous phase extraction method and the combination of purification methods, so as to provide certain reference for further research and development.
基金supported in part by the Shenzhen Col-laborative Innovation Special Plan International Coopera-tion Research Project(No.GJHZ20220913144400001)the General Research Project of Shenzhen Science and Technology Plan(No.JCYJ20220818100000001).
文摘Excessive temperature rise during the operation of the generator system can affect the safety and life cycle of the machine.Therefore,in order to accurately obtain the internal temperature of the switched reluctance generator(SRG),an internal temperature estimation model based on electric heating is established in this paper.First,an im-proved variable coefficient Bertotti loss separation calcula-tion formula is adopted to solve the iron loss of the genera-tor under various operating conditions.Subsequently,the accurate heat source parameters in the temperature model can be obtained,and the corresponding heat source data can be calculated.Then,based on the obtained heat source data,an equivalent thermal circuit model is established for SRG.Meanwhile,in order to effectively reduce the internal temperature during SRG operation,a new water-cooled structure for direct cooling of SRG stator windings is pro-posed in this paper,which can effectively reduce the tem-perature rise during operation,thus improving the reliabil-ity of the generator.Finally,by comparing the equivalent thermal circuit model,finite element thermal model,and experimental temperature measurements of SRG,it is found that results from the equivalent thermal circuit model of the SRG are closer to the measured temperatures,while the effectiveness of the water-cooled structure is verified.
文摘Skills are the foundation on which to build a strong nation,and also the foundation on which to start one's career.Xi Jinping,General Secretary of the Communist Party of China(CPC)Central Committee,has called for the promotion of the spirit of craftsmanship throughout society,and for the encouragement of young people to become highly skilled talents who serve China with their skills.When delivering his report to the 20th CPC National Congress,on October 16,2022,Xi Jinping said,"We will speed up efforts to build a contingent of personnel with expertise of strategic importance and cultivate greater numbers of master scholars,science strategists,first-class scientists and innovation teams,young scientists,outstanding engineers,master craftsmen,and highly skilled workers."
文摘Beijing Overseas Cultural Exchanges Center has created an online roadmap of the Cultural Tour of Peking Opera,which highlights Peking Opera theaters,former residences of Peking Opera artists,guild halls and other places used for Peking Opera performances.The center advocates low-carbon travel,and it recommends a cycling route of the Cultural Tour of Peking Opera.While cycling along the streets of Beijing,people can visit landmark buildings of the Peking Opera,and they can feel the unique charm of the city.
文摘Women have become an important force in promoting scientific and technological advancement globally.Many women scientists,worldwide,have created“miracles”that have greatly promoted the development of human civilization.
