BACKGROUND： The change in expression of synaptophysin （Syp） and postsynaptic density-95 （PSD-95） alters after cerebral infarction, and the plasticity of synapses contributes greatly to nerve function recovery. Ch...BACKGROUND： The change in expression of synaptophysin （Syp） and postsynaptic density-95 （PSD-95） alters after cerebral infarction, and the plasticity of synapses contributes greatly to nerve function recovery. Chinese medicinal substances may play an important role in the expression of Syp and PSD-95. OBJECTIVE： To observe the effect of Panaxtriol Saponins （PTS）, an active component in Sanqi tongshu capsules, on the expression of Syp and PSD-95 after cerebral infarction at different time points in rats, so as to examine the cerebral function remodeling mechanism. DESIGN, TIME AND SETTING： A randomized and controlled observation which was performed in Dongzhimen Hospital, Beijing University of Traditional Chinese Medicine from January to March, 2007. MATERIALS： Twenty-six healthy male Sprague Dawley rats were used to establish middle cerebral artery occlusion based on the Longa method. Sanqi tongshu capsules （containing 100 mg PTS per tablet） were provided by the Chengdu Huashen Group and nimodipine tablets （30 mg） by Tianjin Zhongyang Pharmaceutical Co., Ltd. METHODS： Twenty-six rats were randomly divided into an operation group （n = 21 ） and a control group （n = 5）. The operation group underwent the EZ Longa procedure to make the middle cerebral artery occlusion model. After surgery rats were randomly divided into a model group, a PTS group and a nimodipine group, with seven rats in each group. Rats were intragastrically administrated with saline （2 mL/d） in the model group, with Sanqi tongshu capsule （5.4 mg/100 g/d） in the PTS group, and with nimodipine （1.73 mg/100 g/d） in the nimodipine group. Rats in the control group did not undergo model establishment and drug administration. MAIN OUTCOME MEASURES： The expressions of Syp and PSD-95 were measured by immunohistochemical and image analysis at days 3, 7 and 28 after the operation. RESULTS： The expression of Syp and PSD-95 in the operation group was significantly lower than in the control group at days 3, 7, 28 postoperatively （P 〈 0.05）. The expression of Syp and PSD-95 in the PTS group and nimodipine group was significantly higher than in the model group at day 28 postoperatively （P 〈 0.05-0.01）. Additionally, after PTS and nimodipine treatment at different intervals, the expression of Syp and PSD-95 at day 28 postoperatively was significantly higher than those at days 3 and 7 postoperatively, respectively （P 〈 0.01）. CONCLUSION： PTS can promote the expression of Syp and PSD-95, i.e. the remodeling process of synapses, after cerebral infarction at different time points in rats, which contributes to cerebral function remodeling.展开更多
Background:An influenza forecasting system is critical to influenza epidemic preparedness.Low temperature has long been recognized as a condition favoring influenza epidemic,yet it fails to justify the summer influenz...Background:An influenza forecasting system is critical to influenza epidemic preparedness.Low temperature has long been recognized as a condition favoring influenza epidemic,yet it fails to justify the summer influenza peak in tropics/subtropics.Recent studies have suggested that absolute humidity(AH)had a U-shape relationship with influenza survival and transmission across climate zones,indicating that a unified influenza forecasting system could be established for China with various climate conditions.Methods:Our study has generated weekly influenza forecasts by season and type/subtype in northern and southern China from 2011 to 2021,using a forecasting system combining an AH-driven susceptible-infected-recovered-susceptible(SIRS)model and the ensemble adjustment Kalman filter(EAKF).Model performance was assessed by sensitivity and specificity in predicting epidemics,and by accuracies in predicting peak timing and magnitude.Results:Our forecast system can generally well predict seasonal influenza epidemics(mean sensitivity>87.5%;mean specificity>80%).The average forecast accuracies were 82%and 60%for peak timing and magnitude at 3e6 weeks ahead for northern China,higher than those of 42%and 20%for southern China.The accuracy was generally better when the forecast was made closer to the actual peak time.Discussion:The established AH-driven forecasting system can generally well predict the occurrence of seasonal influenza epidemics in China.展开更多
Multiple plant lineages have independently evolved sex chromosomes and variable karyotypes to maintain their sessile lifestyles through constant biological innovation.Morus notabilis,a dioecious mulberry species,has t...Multiple plant lineages have independently evolved sex chromosomes and variable karyotypes to maintain their sessile lifestyles through constant biological innovation.Morus notabilis,a dioecious mulberry species,has the fewest chromosomes among Morus spp.,but the genetic basis of sex determination and karyotype evolution in this species has not been identified.In this study,three high-quality genome assemblies were generated for Morus spp.[including dioecious M.notabilis(male and female)and Morus yunnanensis(female)]with genome sizes of 301–329 Mb and were grouped into six pseudochromosomes.Using a combination of genomic approaches,we found that the putative ancestral karyotype of Morus species was close to 14 protochromosomes,and that several chromosome fusion events resulted in descending dysploidy(2n=2x=12).We also characterized a~6.2-Mb sex-determining region on chromosome 3.Four potential male-specific genes,a partially duplicated DNA helicase gene(named MSDH)and three Ty3_Gypsy long terminal repeat retrotransposons(named MSTG1/2/3),were identified in the Y-linked area and considered to be strong candidate genes for sex determination or differentiation.Population genomic analysis showed that Guangdong accessions in China were genetically similar to Japanese accessions of mulberry.In addition,genomic areas containing selective sweeps that distinguish domesticated mulberry from wild populations in terms of flowering and disease resistance were identified.Our study provides an important genetic resource for sex identification research and molecular breeding in mulberry.展开更多
Flowering time is of great significance for crop reproduction,yield,and regional adaptability,which is intricately regulated by various environmental cues and endogenous signals.Genetic approaches in Arabidopsis have ...Flowering time is of great significance for crop reproduction,yield,and regional adaptability,which is intricately regulated by various environmental cues and endogenous signals.Genetic approaches in Arabidopsis have revealed the elaborate underlying mechanisms of sensing the dynamic change of photoperiod via a coincidence between light signaling and circadian clock,the cellular time keeping system,to precisely control photoperiodic flowering time,and many other signaling pathways including internal hormones and external temperature cues.Extensive studies in rice(Oryza sativa.),one of the short-day plants(SDP),have uncovered the multiple major genetic components in regulating heading date,and revealed the underlying mechanisms for regulating heading date.Here we summarize the current progresses on the molecular basis for rice heading date control,especially focusing on the integration mechanism between photoperiod and circadian clock,and epigenetic regulation and heading procedures in response to abiotic stresses.展开更多
Plants with crassulacean acid metabolism(CAM) generally utilize water 20%–80% more efficiently than non-CAM plants. The whole genomes of several CAM plants have been sequenced or are being sequenced. For effective ge...Plants with crassulacean acid metabolism(CAM) generally utilize water 20%–80% more efficiently than non-CAM plants. The whole genomes of several CAM plants have been sequenced or are being sequenced. For effective genome characterization and genome editing of CAM plants,an efficient transformation system is essential. In this study, we developed an Agrobacterium-mediated transformation protocol for Kalanchoe laxiflora, an obligate CAM plant,by optimizing several factors affecting the transformation efficiency. Agrobacterium strains AGL1, C58, EHA105,and GV3101 were all suitable for K. laxiflora transformation. Fifty-nine percent of the leaf explants yielded kanamycin-resistant and GUS-positive shoots. Polymerase chain reaction and quantitative real-time PCR(qRT-PCR) using gus A-, gus Plus-, npt II-and hpt-specific primers confirmed that the transgenes were integrated into K. laxiflora genome and expressed. This efficient transformation system will allow effective functional characterization of genes through over-or down-expression, knockout, or genome editing.展开更多
基金the National Natural Science Foundation of China,No.30472214
文摘BACKGROUND： The change in expression of synaptophysin （Syp） and postsynaptic density-95 （PSD-95） alters after cerebral infarction, and the plasticity of synapses contributes greatly to nerve function recovery. Chinese medicinal substances may play an important role in the expression of Syp and PSD-95. OBJECTIVE： To observe the effect of Panaxtriol Saponins （PTS）, an active component in Sanqi tongshu capsules, on the expression of Syp and PSD-95 after cerebral infarction at different time points in rats, so as to examine the cerebral function remodeling mechanism. DESIGN, TIME AND SETTING： A randomized and controlled observation which was performed in Dongzhimen Hospital, Beijing University of Traditional Chinese Medicine from January to March, 2007. MATERIALS： Twenty-six healthy male Sprague Dawley rats were used to establish middle cerebral artery occlusion based on the Longa method. Sanqi tongshu capsules （containing 100 mg PTS per tablet） were provided by the Chengdu Huashen Group and nimodipine tablets （30 mg） by Tianjin Zhongyang Pharmaceutical Co., Ltd. METHODS： Twenty-six rats were randomly divided into an operation group （n = 21 ） and a control group （n = 5）. The operation group underwent the EZ Longa procedure to make the middle cerebral artery occlusion model. After surgery rats were randomly divided into a model group, a PTS group and a nimodipine group, with seven rats in each group. Rats were intragastrically administrated with saline （2 mL/d） in the model group, with Sanqi tongshu capsule （5.4 mg/100 g/d） in the PTS group, and with nimodipine （1.73 mg/100 g/d） in the nimodipine group. Rats in the control group did not undergo model establishment and drug administration. MAIN OUTCOME MEASURES： The expressions of Syp and PSD-95 were measured by immunohistochemical and image analysis at days 3, 7 and 28 after the operation. RESULTS： The expression of Syp and PSD-95 in the operation group was significantly lower than in the control group at days 3, 7, 28 postoperatively （P 〈 0.05）. The expression of Syp and PSD-95 in the PTS group and nimodipine group was significantly higher than in the model group at day 28 postoperatively （P 〈 0.05-0.01）. Additionally, after PTS and nimodipine treatment at different intervals, the expression of Syp and PSD-95 at day 28 postoperatively was significantly higher than those at days 3 and 7 postoperatively, respectively （P 〈 0.01）. CONCLUSION： PTS can promote the expression of Syp and PSD-95, i.e. the remodeling process of synapses, after cerebral infarction at different time points in rats, which contributes to cerebral function remodeling.
基金supported by the Three-year Public Health System Construction Program of Shanghai,from Shanghai Municipal Health Commission of China[grant number GWV-10.2-YQ36].
文摘Background:An influenza forecasting system is critical to influenza epidemic preparedness.Low temperature has long been recognized as a condition favoring influenza epidemic,yet it fails to justify the summer influenza peak in tropics/subtropics.Recent studies have suggested that absolute humidity(AH)had a U-shape relationship with influenza survival and transmission across climate zones,indicating that a unified influenza forecasting system could be established for China with various climate conditions.Methods:Our study has generated weekly influenza forecasts by season and type/subtype in northern and southern China from 2011 to 2021,using a forecasting system combining an AH-driven susceptible-infected-recovered-susceptible(SIRS)model and the ensemble adjustment Kalman filter(EAKF).Model performance was assessed by sensitivity and specificity in predicting epidemics,and by accuracies in predicting peak timing and magnitude.Results:Our forecast system can generally well predict seasonal influenza epidemics(mean sensitivity>87.5%;mean specificity>80%).The average forecast accuracies were 82%and 60%for peak timing and magnitude at 3e6 weeks ahead for northern China,higher than those of 42%and 20%for southern China.The accuracy was generally better when the forecast was made closer to the actual peak time.Discussion:The established AH-driven forecasting system can generally well predict the occurrence of seasonal influenza epidemics in China.
基金supported by the National Key R&D Program of China(Grant No.2019YFD1000604)the China Agriculture Research System(Grant No.CARS-18-ZJ0201)+1 种基金the Forestry Promotion by Science and Technology Program of Chongqing,China(Grant No.Yulinkeyan2020-2)the Sichuan Science and Technology Program,China(Grant No.22NSFSC3680).
文摘Multiple plant lineages have independently evolved sex chromosomes and variable karyotypes to maintain their sessile lifestyles through constant biological innovation.Morus notabilis,a dioecious mulberry species,has the fewest chromosomes among Morus spp.,but the genetic basis of sex determination and karyotype evolution in this species has not been identified.In this study,three high-quality genome assemblies were generated for Morus spp.[including dioecious M.notabilis(male and female)and Morus yunnanensis(female)]with genome sizes of 301–329 Mb and were grouped into six pseudochromosomes.Using a combination of genomic approaches,we found that the putative ancestral karyotype of Morus species was close to 14 protochromosomes,and that several chromosome fusion events resulted in descending dysploidy(2n=2x=12).We also characterized a~6.2-Mb sex-determining region on chromosome 3.Four potential male-specific genes,a partially duplicated DNA helicase gene(named MSDH)and three Ty3_Gypsy long terminal repeat retrotransposons(named MSTG1/2/3),were identified in the Y-linked area and considered to be strong candidate genes for sex determination or differentiation.Population genomic analysis showed that Guangdong accessions in China were genetically similar to Japanese accessions of mulberry.In addition,genomic areas containing selective sweeps that distinguish domesticated mulberry from wild populations in terms of flowering and disease resistance were identified.Our study provides an important genetic resource for sex identification research and molecular breeding in mulberry.
基金supported by National Key Research and Development Program of China(2016YFD0100600)National Natural Science Foundation of China(No.31770287).
文摘Flowering time is of great significance for crop reproduction,yield,and regional adaptability,which is intricately regulated by various environmental cues and endogenous signals.Genetic approaches in Arabidopsis have revealed the elaborate underlying mechanisms of sensing the dynamic change of photoperiod via a coincidence between light signaling and circadian clock,the cellular time keeping system,to precisely control photoperiodic flowering time,and many other signaling pathways including internal hormones and external temperature cues.Extensive studies in rice(Oryza sativa.),one of the short-day plants(SDP),have uncovered the multiple major genetic components in regulating heading date,and revealed the underlying mechanisms for regulating heading date.Here we summarize the current progresses on the molecular basis for rice heading date control,especially focusing on the integration mechanism between photoperiod and circadian clock,and epigenetic regulation and heading procedures in response to abiotic stresses.
基金supported by the Tennessee Agricultural Experiment Station Hatch Project (TEN00491)Fundamental Research Funds for the Central Universities (XDJK2018C065)
文摘Plants with crassulacean acid metabolism(CAM) generally utilize water 20%–80% more efficiently than non-CAM plants. The whole genomes of several CAM plants have been sequenced or are being sequenced. For effective genome characterization and genome editing of CAM plants,an efficient transformation system is essential. In this study, we developed an Agrobacterium-mediated transformation protocol for Kalanchoe laxiflora, an obligate CAM plant,by optimizing several factors affecting the transformation efficiency. Agrobacterium strains AGL1, C58, EHA105,and GV3101 were all suitable for K. laxiflora transformation. Fifty-nine percent of the leaf explants yielded kanamycin-resistant and GUS-positive shoots. Polymerase chain reaction and quantitative real-time PCR(qRT-PCR) using gus A-, gus Plus-, npt II-and hpt-specific primers confirmed that the transgenes were integrated into K. laxiflora genome and expressed. This efficient transformation system will allow effective functional characterization of genes through over-or down-expression, knockout, or genome editing.
