Plasma membrane intrinsic proteins （PIPs） are a subfamily ofaquaporins that enable fast and controlled translocation of water across the membrane. In this study, we systematically identified and cloned ten PIP genes...Plasma membrane intrinsic proteins （PIPs） are a subfamily ofaquaporins that enable fast and controlled translocation of water across the membrane. In this study, we systematically identified and cloned ten PIP genes from rice. Based on the similarity of the amino acid sequences they encoded, these rice PIP genes were classified into two groups and designated as OsPIP1-1 to OsPIP1-3 and OsPIP2-1 to OsPIP2-7 following the nomenclature of PIP genes in maize. Quantitative RT-PCR analysis identified three root-specific and one leaf-specific OsPIP genes. Furthermore, the expression profile of each OsPIP gene in response to salt, drought and ABA treatment was examined in detail. Analysis on transgenic plants over-expressing of either OsPIP1 （OsPIP1-1） or OsPIP2 （OsPIP2-2） in wild-type Arabidopsis, showed enhanced tolerance to salt （100 mM of NaCl） and drought （200 mM ofmannitol）, but not to salt treatment of higher concentration （150 mM of NaCl）. Taken together, these data suggest a distinct role of each OsPIP gene in response to different stresses, and should add a new layer to the understanding of the physiological function of rice PIP genes.展开更多
The impact of supercritical CO2/H2O technology on the threshold-voltage instability of AlGaN/GaN metal-insulator semiconductor high-electron-mobility transistors(MIS-HEMTs) is investigated. The MIS-HEMTs were placed i...The impact of supercritical CO2/H2O technology on the threshold-voltage instability of AlGaN/GaN metal-insulator semiconductor high-electron-mobility transistors(MIS-HEMTs) is investigated. The MIS-HEMTs were placed in a supercritical fluid system chamber at 150℃ for 3 h. The chamber was injected with CO2 and H2O at pressure of 3000 psi(1 psi ≈ 6.895 kPa). Supercritical H2O fluid has the characteristics of liquid H2O and gaseous H2O at the same time, that is, high penetration and high solubility. In addition, OH-produced by ionization of H2O can fill the nitrogen vacancy near the Si3N4/GaN/AlGaN interface caused by high temperature process. After supercritical CO2/H2O treatment, the threshold voltage shift is reduced from 1 V to 0.3 V. The result shows that the threshold voltage shift of MIS-HEMTs could be suppressed by supercritical CO2/H2O treatment.展开更多
This paper proposes a method of repairing interface defects by supercritical nitridation technology,in order to suppress the threshold voltage shift of AlGaN/GaN metal-insulator-semiconductor high-electron-mobility tr...This paper proposes a method of repairing interface defects by supercritical nitridation technology,in order to suppress the threshold voltage shift of AlGaN/GaN metal-insulator-semiconductor high-electron-mobility transistors(MIS-HEMTs).We find that supercritical NH3 fluid has the characteristics of both liquid NH3 and gaseous NH3 simultaneously,i.e.,high penetration and high solubility,which penetrate the packaging of MIS-HEMTs.In addition,NH2^-produced via the auto coupling ionization of NH3 has strong nucleophilic ability,and is able to fill nitrogen vacancies near the GaN surface created by high temperature processes.After supercritical fluid treatment,the threshold voltage shift is reduced from 1 V to 0 V,and the interface trap density is reduced by two orders of magnitude.The results show that the threshold voltage shift of MIS-HEMTs can be effectively suppressed by means of supercritical nitridation technology.展开更多
Not much research has been done on motivation to study a second,third or even fourth foreign language though learners of such languages have been increasing.To contribute to this,the present study examined German lear...Not much research has been done on motivation to study a second,third or even fourth foreign language though learners of such languages have been increasing.To contribute to this,the present study examined German learning motivation of Chinese university students at different proficiency levels.A total of 297 German learners at three different proficiency levels at a university in Beijing filled in the questionnaires,of whom 191 answered the open-ended question and 50 were informally interviewed.Analyses of the data revealed the following major findings;(1)most respondents at cach proficiency level had limited access to and little chance to use German,liked the language,studied it(very)hard and did not think the language was difficult,(2)students at different proficiency levels studied German for similar reasons such as major study/research,further education,future career,interest in foreign language learning and German,and(3)students at higher proficiency levels perceived German to be more difficult and worked harder on it.Students at higher proficiency levels were both integratively and instrumentally more motivated to study German and had greater motivation intensity as well.It is clear that students at different proficiency levels were motivated to study German and that students at the advanced level tended to be more integratively motivated than those at the beginning level.Based on these findings,some suggestions are discussed.展开更多
Dietary intake has an impact on the development of gut microbiota.Humans require carbohydrates,protein,fat,and other nutrients on a daily basis to provide energy for the growth,maintenance,and repair of body tissues.T...Dietary intake has an impact on the development of gut microbiota.Humans require carbohydrates,protein,fat,and other nutrients on a daily basis to provide energy for the growth,maintenance,and repair of body tissues.These nutrition-induced changes in gut microbiota may be used to alter host physiology,including disease development and progression,such as obesity and diabetes.More research is needed to fully understand how diet influences microbiota and how microbiota influence host health.The pathways of carbohydrate,protein,and fat metabolism,as well as their interactions and regulatory mechanisms,are described in this review,as well as how diet shapes the microbiota,how dietary-microbiome crosstalk may affect disease development and progression,and how this information could be used to maintain intestinal health.展开更多
It was shown in a previous analysis that D5 gene from rice (Oryza sativa L.) was an anther-specific gene encoding a chalcone synthase-related protein. In this study, D5 gene was found specifically expressed in tapetum...It was shown in a previous analysis that D5 gene from rice (Oryza sativa L.) was an anther-specific gene encoding a chalcone synthase-related protein. In this study, D5 gene was found specifically expressed in tapetum cells as well as in the peripheral cells of the vascular bundle of rice anthers by RNA in situ hybridization. In order to study its function, D5 was transformed into rice in both sense and antisense directions driven by a rice Actin 1 promoter. It has been observed that the pollen grains from the antisense D5 transgenic rice plants are abnormal, indicating that D5 plays a critical role in rice pollen development.展开更多
Exorbitant aldosterone is closely associated with various severe diseases,including congestive heart failure and chronic kidney disease.As aldosterone synthase is the pivotal enzyme in aldosterone biosynthesis,its inh...Exorbitant aldosterone is closely associated with various severe diseases,including congestive heart failure and chronic kidney disease.As aldosterone synthase is the pivotal enzyme in aldosterone biosynthesis,its inhibition constitutes a promising treatment for these diseases.Via a structure-based approach,a series of pyridyl substituted 3,4-dihydrobenzo[f][1,4]oxazepin-5(2 H)-ones were designed as inhibitors of aldosterone synthase.Six compounds(5 j,5 l,5 m 5 w,5 x and 5 y)distinguished themselves with potent inhibition(IC50<100 nmol/L)and high selectivity over homogenous 11β-hydroxylase.As the most promising compound,5 x exhibited an IC_(50) of 12 nmol/L and an excellent selectivity factor(SF)of157,which are both superior to those of the re ference fadrazole(IC_(50)=21 nmol/L,SF=7).Importantly,5 x showed no inhibition against steroidogenic CYP17,CYP19 and a panel of hepatic CYP enzymes indicating an outstanding sa fety profile.As it manifested satis factory pharmacokinetic pro perties in rats,compound5 x was considered as a drug candidate for further development.展开更多
The development of stamen is an important stage during the sexual reproduction in higher plants. Studying the genes that predominantly or even specifically expressed in stamens will aid in understanding the molecular ...The development of stamen is an important stage during the sexual reproduction in higher plants. Studying the genes that predominantly or even specifically expressed in stamens will aid in understanding the molecular mechanism of stamen development. The structure of a rice CHS-like gene (D5) which predominantly expressed in anthers has been analysized, showing high structural similarity with two other anther-specific genes (A1 and BA42) from Brassica napus. Northern analysis also reveals that the three genes share a similar expression pattern and that the expression of D5 may relate to the early development of pollens. It is concluded that D5, A1 and BA42 represent a group of diverged CHS-like genes which are related to stamen development.展开更多
文摘Plasma membrane intrinsic proteins （PIPs） are a subfamily ofaquaporins that enable fast and controlled translocation of water across the membrane. In this study, we systematically identified and cloned ten PIP genes from rice. Based on the similarity of the amino acid sequences they encoded, these rice PIP genes were classified into two groups and designated as OsPIP1-1 to OsPIP1-3 and OsPIP2-1 to OsPIP2-7 following the nomenclature of PIP genes in maize. Quantitative RT-PCR analysis identified three root-specific and one leaf-specific OsPIP genes. Furthermore, the expression profile of each OsPIP gene in response to salt, drought and ABA treatment was examined in detail. Analysis on transgenic plants over-expressing of either OsPIP1 （OsPIP1-1） or OsPIP2 （OsPIP2-2） in wild-type Arabidopsis, showed enhanced tolerance to salt （100 mM of NaCl） and drought （200 mM ofmannitol）, but not to salt treatment of higher concentration （150 mM of NaCl）. Taken together, these data suggest a distinct role of each OsPIP gene in response to different stresses, and should add a new layer to the understanding of the physiological function of rice PIP genes.
基金Project supported by Shenzhen Science and Technology Innovation Committee(Grant Nos.ZDSYS201802061805105,JCYJ20190808155007550,QJSCX20170728102129176,and JCYJ20170810163407761)the National Natural Science Foundation of China(Grant No.U1613215).
文摘The impact of supercritical CO2/H2O technology on the threshold-voltage instability of AlGaN/GaN metal-insulator semiconductor high-electron-mobility transistors(MIS-HEMTs) is investigated. The MIS-HEMTs were placed in a supercritical fluid system chamber at 150℃ for 3 h. The chamber was injected with CO2 and H2O at pressure of 3000 psi(1 psi ≈ 6.895 kPa). Supercritical H2O fluid has the characteristics of liquid H2O and gaseous H2O at the same time, that is, high penetration and high solubility. In addition, OH-produced by ionization of H2O can fill the nitrogen vacancy near the Si3N4/GaN/AlGaN interface caused by high temperature process. After supercritical CO2/H2O treatment, the threshold voltage shift is reduced from 1 V to 0.3 V. The result shows that the threshold voltage shift of MIS-HEMTs could be suppressed by supercritical CO2/H2O treatment.
基金Supported by the Shenzhen Science and Technology Innovation Committee(Grant Nos.ZDSYS201802061805105,JCYJ20190808155007550K,QJSCX20170728102129176,and JCYJ20170810163407761)the National Natural Science Foundation of China(Grant No.U1613215)。
文摘This paper proposes a method of repairing interface defects by supercritical nitridation technology,in order to suppress the threshold voltage shift of AlGaN/GaN metal-insulator-semiconductor high-electron-mobility transistors(MIS-HEMTs).We find that supercritical NH3 fluid has the characteristics of both liquid NH3 and gaseous NH3 simultaneously,i.e.,high penetration and high solubility,which penetrate the packaging of MIS-HEMTs.In addition,NH2^-produced via the auto coupling ionization of NH3 has strong nucleophilic ability,and is able to fill nitrogen vacancies near the GaN surface created by high temperature processes.After supercritical fluid treatment,the threshold voltage shift is reduced from 1 V to 0 V,and the interface trap density is reduced by two orders of magnitude.The results show that the threshold voltage shift of MIS-HEMTs can be effectively suppressed by means of supercritical nitridation technology.
文摘Not much research has been done on motivation to study a second,third or even fourth foreign language though learners of such languages have been increasing.To contribute to this,the present study examined German learning motivation of Chinese university students at different proficiency levels.A total of 297 German learners at three different proficiency levels at a university in Beijing filled in the questionnaires,of whom 191 answered the open-ended question and 50 were informally interviewed.Analyses of the data revealed the following major findings;(1)most respondents at cach proficiency level had limited access to and little chance to use German,liked the language,studied it(very)hard and did not think the language was difficult,(2)students at different proficiency levels studied German for similar reasons such as major study/research,further education,future career,interest in foreign language learning and German,and(3)students at higher proficiency levels perceived German to be more difficult and worked harder on it.Students at higher proficiency levels were both integratively and instrumentally more motivated to study German and had greater motivation intensity as well.It is clear that students at different proficiency levels were motivated to study German and that students at the advanced level tended to be more integratively motivated than those at the beginning level.Based on these findings,some suggestions are discussed.
基金supported by Taishan Industry Talents Project(tscy20200221)the Key Research and Develop Program of Shandong Province(2020CXGC010601).
文摘Dietary intake has an impact on the development of gut microbiota.Humans require carbohydrates,protein,fat,and other nutrients on a daily basis to provide energy for the growth,maintenance,and repair of body tissues.These nutrition-induced changes in gut microbiota may be used to alter host physiology,including disease development and progression,such as obesity and diabetes.More research is needed to fully understand how diet influences microbiota and how microbiota influence host health.The pathways of carbohydrate,protein,and fat metabolism,as well as their interactions and regulatory mechanisms,are described in this review,as well as how diet shapes the microbiota,how dietary-microbiome crosstalk may affect disease development and progression,and how this information could be used to maintain intestinal health.
文摘It was shown in a previous analysis that D5 gene from rice (Oryza sativa L.) was an anther-specific gene encoding a chalcone synthase-related protein. In this study, D5 gene was found specifically expressed in tapetum cells as well as in the peripheral cells of the vascular bundle of rice anthers by RNA in situ hybridization. In order to study its function, D5 was transformed into rice in both sense and antisense directions driven by a rice Actin 1 promoter. It has been observed that the pollen grains from the antisense D5 transgenic rice plants are abnormal, indicating that D5 plays a critical role in rice pollen development.
基金supported by the National Natural Science Foundation of China(No.81872739)the Zhujiang Distinguish Professorship of Guangdong Province,China(2018)+1 种基金the International Scientific Collaboration Program of Guangdong Province,China(No.2020A0505100053)the Key Research and Development Program of Guangdong Province,China(No.2019B02021002)。
文摘Exorbitant aldosterone is closely associated with various severe diseases,including congestive heart failure and chronic kidney disease.As aldosterone synthase is the pivotal enzyme in aldosterone biosynthesis,its inhibition constitutes a promising treatment for these diseases.Via a structure-based approach,a series of pyridyl substituted 3,4-dihydrobenzo[f][1,4]oxazepin-5(2 H)-ones were designed as inhibitors of aldosterone synthase.Six compounds(5 j,5 l,5 m 5 w,5 x and 5 y)distinguished themselves with potent inhibition(IC50<100 nmol/L)and high selectivity over homogenous 11β-hydroxylase.As the most promising compound,5 x exhibited an IC_(50) of 12 nmol/L and an excellent selectivity factor(SF)of157,which are both superior to those of the re ference fadrazole(IC_(50)=21 nmol/L,SF=7).Importantly,5 x showed no inhibition against steroidogenic CYP17,CYP19 and a panel of hepatic CYP enzymes indicating an outstanding sa fety profile.As it manifested satis factory pharmacokinetic pro perties in rats,compound5 x was considered as a drug candidate for further development.
文摘The development of stamen is an important stage during the sexual reproduction in higher plants. Studying the genes that predominantly or even specifically expressed in stamens will aid in understanding the molecular mechanism of stamen development. The structure of a rice CHS-like gene (D5) which predominantly expressed in anthers has been analysized, showing high structural similarity with two other anther-specific genes (A1 and BA42) from Brassica napus. Northern analysis also reveals that the three genes share a similar expression pattern and that the expression of D5 may relate to the early development of pollens. It is concluded that D5, A1 and BA42 represent a group of diverged CHS-like genes which are related to stamen development.
