Carrot(Daucus carota)is an Apiaceae plant with multi-colored fleshy roots that provides a model system for carotenoid research.In this study,we assembled a 430.40 Mb high-quality gapless genome to the telomere-to-telo...Carrot(Daucus carota)is an Apiaceae plant with multi-colored fleshy roots that provides a model system for carotenoid research.In this study,we assembled a 430.40 Mb high-quality gapless genome to the telomere-to-telomere(T2T)level of“Kurodagosun”carrot.In total,36268 genes were identified and 34961 of them were functionally annotated.The proportion of repeat sequences in the genome was 55.3%,mainly long terminal repeats.Depending on the coverage of the repeats,14 telomeres and 9 centromeric regions on the chromosomes were predicted.A phylogenetic analysis showed that carrots evolved early in the family Apiaceae.Based on the T2T genome,we reconstructed the carotenoid metabolic pathway and identified the structural genes that regulate carotenoid biosynthesis.Among the 65 genes that were screened,9 were newly identified.Additionally,some gene sequences overlapped with transposons,suggesting replication and functional differentiation of carotenoid-related genes during carrot evolution.Given that some gene copies were barely expressed during development,they might be functionally redundant.Comparison of 24 cytochrome P450 genes associated with carotenoid biosynthesis revealed the tandem or proximal duplication resulting in expansion of CYP gene family.These results provided molecular information for carrot carotenoid accumulation and contributed to a new genetic resource.展开更多
For electromagnetic wave-absorbing materials,maximizing absorption at a specific frequency has been constantly achieved,but enhancing the absorption properties in the entire band remains a challenge.In this work,a 3D ...For electromagnetic wave-absorbing materials,maximizing absorption at a specific frequency has been constantly achieved,but enhancing the absorption properties in the entire band remains a challenge.In this work,a 3D porous pyrolytic carbon(PyC)foam matrix was synthesized by a template method.Amorphous carbon nanotubes(CNTs)were then in-situ grown on the matrix surface to obtain ultralight CNTs/Py C foam.These in-situ grown amorphous CNTs were distributed uniformly and controlled by the catalytic growth time and can enhance the interface polarization and conduction loss of composites.When the electromagnetic wave enters the internal holes,the electromagnetic energy can be completely attenuated under the combined action of polarization,conductivity loss,and multiple reflections.The ultralight CNTs/Py C foam had a density of 22.0 mg·cm^(-3)and a reflection coefficient lower than-13.3 d B in the whole X-band(8.2-12.4 GHz),which is better than the conventional standard of effective absorption bandwidth(≤-10 dB).The results provide ideas for researching ultralight and strong electromagnetic wave absorbing materials in the X-band.展开更多
Precise resources and energy forecasting are important to facilitate the decision-making process in order to achieve higher efficiency and reliability in energy system planning,maintenance,operation,security,and so on...Precise resources and energy forecasting are important to facilitate the decision-making process in order to achieve higher efficiency and reliability in energy system planning,maintenance,operation,security,and so on.In the past decades,many resources and energy forecasting models have been continuously proposed to increase the forecasting accuracy,especially intelligence models(e.g.,artificial neural networks,support vector regression,evolutionary computation models,etc.).Meanwhile,due to the great development of optimization methods(e.g.,quadratic programming method,differential empirical mode method,evolutionary algorithms,etc.),many novel hybrid methods combined with the above-mentioned intelligent-optimization-based methods have also been proposed to achieve satisfactory forecasting accuracy levels.It is worthwhile to explore the tendency and development of intelligent-optimization-based hybrid methodologies and to enrich their practical performances,particularly for resources and energy forecasting.展开更多
基金This article was supported by National Natural Science Foundation of China(32072563,32102369)Natural Science Foundation of Jiangsu Province(BK20211366)+2 种基金Project of Guizhou Provincial Department of Science and Technology(Qiankehe Fuqi[2022005])Project of Guiyang of Science and Technology Bureau(Zhuke contract[2021]5-1)Priority Academic Program Development of Jiangsu Higher Education Institutions Project(PAPD).
文摘Carrot(Daucus carota)is an Apiaceae plant with multi-colored fleshy roots that provides a model system for carotenoid research.In this study,we assembled a 430.40 Mb high-quality gapless genome to the telomere-to-telomere(T2T)level of“Kurodagosun”carrot.In total,36268 genes were identified and 34961 of them were functionally annotated.The proportion of repeat sequences in the genome was 55.3%,mainly long terminal repeats.Depending on the coverage of the repeats,14 telomeres and 9 centromeric regions on the chromosomes were predicted.A phylogenetic analysis showed that carrots evolved early in the family Apiaceae.Based on the T2T genome,we reconstructed the carotenoid metabolic pathway and identified the structural genes that regulate carotenoid biosynthesis.Among the 65 genes that were screened,9 were newly identified.Additionally,some gene sequences overlapped with transposons,suggesting replication and functional differentiation of carotenoid-related genes during carrot evolution.Given that some gene copies were barely expressed during development,they might be functionally redundant.Comparison of 24 cytochrome P450 genes associated with carotenoid biosynthesis revealed the tandem or proximal duplication resulting in expansion of CYP gene family.These results provided molecular information for carrot carotenoid accumulation and contributed to a new genetic resource.
文摘目的探讨术前磁共振成像(magnetic resonance imaging,MRI)瘤周2 cm水肿带的表观扩散系数(apparent diffusion coefficient,ADC)灰度直方图对分析IDH野生型胶质母细胞瘤(glioblastoma,GB)术后空间复发模式的预测价值。方法采用病例-对照研究设计方案,分析陆军特色医学中心神经外科2012年1月至2021年12月采用标准方案治疗且术后定期MRI随访的50例复发性IDH野生型GB患者的影像资料。以复发灶距术腔边缘距离是否>2 cm为标准,根据术后空间复发模式分为原位复发组(n=28)和非原位复发组(n=22)。选取术前轴位MRI增强图像上肿瘤强化最大层面对应的ADC图像层面,采用Mazda软件沿瘤周水肿2 cm范围边缘勾画提取感兴趣区(region of interest,ROI)进行灰度直方图分析,对提取的特征参数进行统计学分析并应用受试者工作特征曲线计算曲线下面积(area under the curve,AUC),评估其诊断效能。结果原位复发组无进展生存期(progression-free survival,PFS)及总生存期(overall survival,OS)均长于非原位复发组(中位PFS:6.6 vs 4.6个月;中位OS:15.4 vs 12.4个月),差异均有统计学意义(PFS:log-rank χ^(2)=4.325,P=0.038;OS:log-rank χ^(2)=4.022,P=0.045)。在ADC灰度直方图提取的9个特征参数中,两组间方差、峰度、第90百分位数的差异有统计学意义(P<0.05)。以方差鉴别不同空间复发模式的诊断效能最佳(AUC:0.804,敏感度:75.00%,特异度:81.82%)。在基于方差、峰度、第90百分位数两两或3个参数联合构建的4种多因素Logistic回归模型中,以3个参数联合构建的模型诊断效能最佳(AUC:0.878,敏感度:78.57%,特异度:86.36%)。结论术前MRI瘤周2 cm水肿带的ADC灰度直方图特征参数可作为预测IDH野生型GB患者术后不同空间复发模式的影像学标记。
基金supported by the National Natural Science Foundation of China(No.51702197)Creative Research Foundation of the Science and Technology on Thermostructural Composite Materials Laboratory,the Natural Science Foundation of Shaanxi Province(No.2022JM248)the Doctoral Scientific Research Foundation of Shaanxi University of Science&Technology(No.BJ16-06)。
文摘For electromagnetic wave-absorbing materials,maximizing absorption at a specific frequency has been constantly achieved,but enhancing the absorption properties in the entire band remains a challenge.In this work,a 3D porous pyrolytic carbon(PyC)foam matrix was synthesized by a template method.Amorphous carbon nanotubes(CNTs)were then in-situ grown on the matrix surface to obtain ultralight CNTs/Py C foam.These in-situ grown amorphous CNTs were distributed uniformly and controlled by the catalytic growth time and can enhance the interface polarization and conduction loss of composites.When the electromagnetic wave enters the internal holes,the electromagnetic energy can be completely attenuated under the combined action of polarization,conductivity loss,and multiple reflections.The ultralight CNTs/Py C foam had a density of 22.0 mg·cm^(-3)and a reflection coefficient lower than-13.3 d B in the whole X-band(8.2-12.4 GHz),which is better than the conventional standard of effective absorption bandwidth(≤-10 dB).The results provide ideas for researching ultralight and strong electromagnetic wave absorbing materials in the X-band.
基金supported by the Ministry of Science and Technol-ogy,Taiwan(MOST110-2410-H-161-001)Science Foundation of Ministry of Education of China(21YJC630072)Natural Science Foundation of Hebei Province,China(G2020403008).
文摘Precise resources and energy forecasting are important to facilitate the decision-making process in order to achieve higher efficiency and reliability in energy system planning,maintenance,operation,security,and so on.In the past decades,many resources and energy forecasting models have been continuously proposed to increase the forecasting accuracy,especially intelligence models(e.g.,artificial neural networks,support vector regression,evolutionary computation models,etc.).Meanwhile,due to the great development of optimization methods(e.g.,quadratic programming method,differential empirical mode method,evolutionary algorithms,etc.),many novel hybrid methods combined with the above-mentioned intelligent-optimization-based methods have also been proposed to achieve satisfactory forecasting accuracy levels.It is worthwhile to explore the tendency and development of intelligent-optimization-based hybrid methodologies and to enrich their practical performances,particularly for resources and energy forecasting.
