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991.
992.
The evolution of mining-induced stress field in longwall panel is closely related to the fracture field and the breaking characteristics of strata.Few laborator...  相似文献   
993.
Shi  Shun  Wang  JiaYu  Wang  TianRan  Ren  Hui  Zhou  YuHao  Li  Gao  He  ChaoLiang  Chen  XueSi 《中国科学:技术科学(英文版)》2021,64(3):641-650
Science China Technological Sciences - Glycopolypeptides as analogs of glycoproteins or glycosaminoglycans represent attractive building blocks for the construction of biomimetic biomaterials....  相似文献   
994.
Rice blast is one of the main diseases in rice and can occur in different rice growth stages. Due to the complicated procedure of panicle blast identification and instability of panicle blast infection influenced by the environment, most cloned rice resistance genes are associated with leaf blast. In this study, a rice panicle blast resistance gene, Pb2, was identified by genome-wide association mapping based on the panicle blast resistance phenotypes of 230 Rice Diversity Panel 1 (RDP1) accessions with 700,000 single-nucleotide polymorphism (SNP) markers. A genome-wide association study identified 18 panicle blast resistance loci (PBRL) within two years, including 9 reported loci and 2 repeated loci (PBRL2 and PBRL13, PBRL10 and PBRL18). Among them, the repeated locus (PBRL10 and PBRL18) was located in chromosome 11. By haplotype and expression analysis, one of the Nucleotide-binding domain and Leucine-rich Repeat (NLR) Pb2 genes was highly conserved in multiple resistant rice cultivars, and its expression was significantly upregulated after rice blast infection. Pb2 encodes a typical NBS-LRR protein with NB-ARC domain and LRR domain. Compared with wild type plants, the transgenic rice of Pb2 showed enhanced resistance to panicle and leaf blast with reduced lesion number. Subcellular localization of Pb2 showed that it is located on plasma membrane, and GUS tissue-staining observation found that Pb2 is highly expressed in grains, leaf tips and stem nodes. The Pb2 transgenic plants showed no difference in agronomic traits with wild type plants. It indicated that Pb2 could be useful for breeding of rice blast resistance.  相似文献   
995.
Placenta accreta spectrum (PAS) accounts for 7% of maternal mortality and is associated with intraoperative and postoperative morbidity caused by massive blood loss, infection, and adjacent organ damage. The aims of this study were to identify the protein biomarkers of PAS and to further explore their pathogenetic roles in PAS. For this purpose, we collected five placentas from pregnant subjects with PAS complications and another five placentas from normal pregnancy (NP) cases. Then, we enriched protein samples by specifically isolating the trophoblast villous, deeply invading into the uterine muscle layer in the PAS patients. Next, fluorescence-based two-dimensional difference gel electrophoresis (2D-DIGE) and MALDI-TOF/MS were used to identify the proteins differentially abundant between PAS and NP placenta tissues. As a result, nineteen spots were determined as differentially abundant proteins, ten and nine of which were more abundant in PAS and NP placenta tissues, respectively. Then, specific validation with western blot assay and immunohisto/cytochemistry (IHC) assay confirmed that heat shock 70 kDa protein 4 (HSPA4) and chorionic somatomammotropin hormone (CSH) were PAS protein biomarkers. Further tube formation assays demonstrated that HSPA4 promoted the in vitro angiogenesis ability of vessel endothelial cells, which is consistent with the in vivo scenario of PAS complications. In this study, we not only identified PAS protein biomarkers but also connected the promoted angiogenesis with placenta invasion, investigating the pathogenetic mechanism of PAS.  相似文献   
996.
根据人工智能技术课程的教学情况,从教学内容、教学方法、教学案例、考核方式、培养实践能力五个方面探讨教学改革.提出在不断更新教学内容和"课堂讲授-课下辅导"模式的基础上,加强网络资源的利用,增加贯穿整个教学过程的分组报告,设计出提高创新能力的教学案例,开展具有多元考核方式以及循序渐进的动态实验设置模式的实践教学改革,以有...  相似文献   
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To enhance the red emission efficiency of Eu3+ complexes, [Eu/Tbx(BPA)3phen] (BPA?=?bisphenol A, phen?=?1,10-phenanthroline) is designed and synthesized. The complexes are characterized fully and their luminescence properties are evaluated. Co-fluorescence is detected in the Eu/Tbx(BPA)3phen complexes, and the existence of Tb3+ enhances the luminescence intensity of the central Eu3+ because of the intramolecular energy transfer from the 5D4 level of Tb3+ to the 5D0 level of Eu3+. The luminescence intensity of europium ions at 615?nm is the highest for Eu/Tb1(BPA)3phen. To improve the thermal stabilities and mechanical properties of pure complexes, Eu/Tb1(BPA)3phen/PAN (PAN?=?polyacrylonitrile) is used to fabricate fibres by electrospinning. Compared with Eu/Tb1(BPA)3phen (τ?=?1.1087?ms), the fibres have a longer fluorescence lifetime of 1.533?ms. The fibres also retain a high quantum yield of 47.16%. Thus, the flexible luminescent fibres have potential applications in many fields.  相似文献   
1000.
以C2H2为碳源,Ar为辅助气体,利用射频等离子体化学气相沉积的方法在载玻片上成功地制备了类金刚石(DLC)薄膜.通过红外光谱分析了所制备DLC薄膜的结构;利用原子力显微镜分析了薄膜的表面形貌;通过表面轮廓仪测量了薄膜的沉积速率;还利用摩擦磨损仪对薄膜的机械性能进行了研究.实验结果表明,制备的DLC薄膜比较致密、均匀,有较好的耐磨性能.  相似文献   
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