目的 探讨基于机器学习的自动阿尔伯塔卒中项目早期计算机断层扫描评分(Alberta Stroke Program Early CT Score,ASPECTS)对不同部位的急性脑梗死(acute cerebral infarction,ACI)患者重组组织型纤溶酶原激活剂(rt-PA)静脉溶栓治疗预后...目的 探讨基于机器学习的自动阿尔伯塔卒中项目早期计算机断层扫描评分(Alberta Stroke Program Early CT Score,ASPECTS)对不同部位的急性脑梗死(acute cerebral infarction,ACI)患者重组组织型纤溶酶原激活剂(rt-PA)静脉溶栓治疗预后的评估价值。方法 回顾性连续收集2021年1月-2023年2月在南昌大学第二附属医院接受静脉溶栓治疗的急性缺血性卒中患者,以DWI序列高信号作为梗死标准,由人工智能软件基于CT的自动ASPECTS评分,收集患者的一般临床资料、自动ASPECTS评分及溶栓3个月后mRS评分。结果 共纳入急性脑梗死患者135例,分为预后良好组(78例)与预后不良组(57例)。预后不良组豆状核、尾状核、岛叶及M1256区的发生率高于预后良好组(P<0.05)。预后不良组的入院NHISS评分、自动ASPECTS评分与预后良好组比较,差异有统计学意义(P<0.05);二元Logistic回归显示基于梗死位置中的豆状核(0R=0.249,95%CI:0.065~0.956,P=0.043)、尾状核(OR=6.036,95%CI:2.119~17.190,P=0.001)、岛叶(OR=0.280,95%CI:0.096~0.812,P=0.019)及M1区(OR=0.289,95%CI:0.704~6.038,P=0.032)是脑梗死预后不良的独立危险因素。NHISS评分(OR=1.072,95%CI:1.004~1.144,P=0.038),ASPECTS评分(OR=0.520,95%CI:0.387~0.699,P<0.001)。结论 梗死位置可以作为急性脑梗死患者溶栓预后评估的重要预测指标,不同区域的自动ASPECTS评分对预后的预估存在差异,豆状核区、尾状核区、岛叶区或M1区梗死的预后较差,我们的发现对于识别溶栓治疗后有预后不良风险的患者具有价值。展开更多
In cold regions,rock structures will be weakened by freeze-thaw cycles under various water immersion conditions.Determining how water immersion conditions impact rock deterioration under freeze-thaw cycles is critical...In cold regions,rock structures will be weakened by freeze-thaw cycles under various water immersion conditions.Determining how water immersion conditions impact rock deterioration under freeze-thaw cycles is critical to assess accurately the frost resistance of engineered rock.In this paper,freeze-thaw cycles(temperature range of-20℃-20℃)were performed on the sandstones in different water immersion conditions(fully,partially and non-immersed in water).Then,computed tomography(CT)tests were conducted on the sandstones when the freeze-thaw number reached 0,5,10,15,20 and 30.Next,the effects of water immersion conditions on the microstructure deterioration of sandstone under freezethaw cycles were evaluated using CT spatial imaging,porosity and damage factor.Finally,focusing on the partially immersed condition,the immersion volume rate was defined to understand the effects of immersion degree on the freeze-thaw damage of sandstone and to propose a damage model considering the freeze-thaw number and immersion degree.The results show that with increasing freeze-thaw number,the porosities and damage factors under fully and partially immersed conditions increase continuously,while those under non-immersed condition first increase and then remain approximately constant.The most severe freeze-thaw damage occurs in fully immersed condition,followed by partially immersed condition and finally non-immersed condition.Interestingly,the freeze-thaw number and the immersion volume rate both impact the microstructure deterioration of the partially immersed sandstone.For the same freeze-thaw number,the damage factor increases approximately linearly with increasing immersion volume rate,and the increasing immersion degree exacerbates the microstructure deterioration of sandstone.Moreover,the proposed model can effectively estimate the freeze-thaw damage of partially immersed sandstone with different immersion volume rates.展开更多
Embryo size is a critical trait determining not only grain yield but also the nutrition of the maize kernel.Up to the present,only a few genes have been characterized affecting the maize embryo/kernel ratio.Here,we id...Embryo size is a critical trait determining not only grain yield but also the nutrition of the maize kernel.Up to the present,only a few genes have been characterized affecting the maize embryo/kernel ratio.Here,we identify 63 genes significantly associated with maize embryo/kernel weight ratio using a genome-wide association study(GWAS).The peak GWAS signal shows that the natural variation in Zea mays COMPACT PLANT2(CT2),encoding the heterotrimeric G proteinαsubunit,is significantly associated with the Embryo/Kernel Weight Ratio(EKWR).Further analyses show that a missense mutation of CT2 increases its enzyme activity and associates with EKWR.The function of CT2 on affecting embryo/kernel weight ratio is further validated by the characterization of two ct2 mutants,for which EKWR is significantly decreased.Subsequently,the key downstream genes of CT2 are identified by combining the differential expression analysis of the ct2 mutant and quantitative trait transcript analysis in the GWAS population.In addition,the allele frequency spectrum shows that CT2 was under selective pressure during maize domestication.This study provides important genetic insights into the natural variation of maize embryo/kernel weight ratio,which could be applied in future maize breeding programs to improve grain yield and nutritional content.展开更多
基金funding support from the National Natural Science Foundation of China(Grant No.12172019).
文摘In cold regions,rock structures will be weakened by freeze-thaw cycles under various water immersion conditions.Determining how water immersion conditions impact rock deterioration under freeze-thaw cycles is critical to assess accurately the frost resistance of engineered rock.In this paper,freeze-thaw cycles(temperature range of-20℃-20℃)were performed on the sandstones in different water immersion conditions(fully,partially and non-immersed in water).Then,computed tomography(CT)tests were conducted on the sandstones when the freeze-thaw number reached 0,5,10,15,20 and 30.Next,the effects of water immersion conditions on the microstructure deterioration of sandstone under freezethaw cycles were evaluated using CT spatial imaging,porosity and damage factor.Finally,focusing on the partially immersed condition,the immersion volume rate was defined to understand the effects of immersion degree on the freeze-thaw damage of sandstone and to propose a damage model considering the freeze-thaw number and immersion degree.The results show that with increasing freeze-thaw number,the porosities and damage factors under fully and partially immersed conditions increase continuously,while those under non-immersed condition first increase and then remain approximately constant.The most severe freeze-thaw damage occurs in fully immersed condition,followed by partially immersed condition and finally non-immersed condition.Interestingly,the freeze-thaw number and the immersion volume rate both impact the microstructure deterioration of the partially immersed sandstone.For the same freeze-thaw number,the damage factor increases approximately linearly with increasing immersion volume rate,and the increasing immersion degree exacerbates the microstructure deterioration of sandstone.Moreover,the proposed model can effectively estimate the freeze-thaw damage of partially immersed sandstone with different immersion volume rates.
基金supported by National Key Research and Development Program of China(2023YFF1000400)National Natural Science Foundation of China(32101693)+2 种基金Key Research and Development Program of Shaanxi(2021ZDLNY01-06)Agricultural Science and Technology Innovation Program of CAAS(CAAS-ZDRW202004)supported by Hatch project(1019088).
文摘Embryo size is a critical trait determining not only grain yield but also the nutrition of the maize kernel.Up to the present,only a few genes have been characterized affecting the maize embryo/kernel ratio.Here,we identify 63 genes significantly associated with maize embryo/kernel weight ratio using a genome-wide association study(GWAS).The peak GWAS signal shows that the natural variation in Zea mays COMPACT PLANT2(CT2),encoding the heterotrimeric G proteinαsubunit,is significantly associated with the Embryo/Kernel Weight Ratio(EKWR).Further analyses show that a missense mutation of CT2 increases its enzyme activity and associates with EKWR.The function of CT2 on affecting embryo/kernel weight ratio is further validated by the characterization of two ct2 mutants,for which EKWR is significantly decreased.Subsequently,the key downstream genes of CT2 are identified by combining the differential expression analysis of the ct2 mutant and quantitative trait transcript analysis in the GWAS population.In addition,the allele frequency spectrum shows that CT2 was under selective pressure during maize domestication.This study provides important genetic insights into the natural variation of maize embryo/kernel weight ratio,which could be applied in future maize breeding programs to improve grain yield and nutritional content.
