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91.
安徽马尾松人工林营养元素分配格局的研究   总被引:11,自引:0,他引:11  
本文系统地研究了马尾松人工林营养元素的分配格局。结果表明马尾松不同器官营养元素含量是叶>枝皮>干皮>枝木>干木;同化器官——针叶中营养元素含量规律为N>K>Ca>Mg>P,非同化器官为Ca>N>K>Mg>P;不同器官营养元素的贮量为干木>干皮>叶>枝木>枝皮,同化器官对不同营养元素的贮量呈N>K>Ca>Mg>P,非同化器官为Ca>N>K>Mg>P;不同立地条件下,马尾松林生产1t干物质所贮存的营养元素不同,立地条件愈好,营养元素效率愈高,贮存愈少;母岩、土层厚度和养分总量是影响马尾松林地上各器官,特别是针叶营养元素含量的重要因子,土壤N、P含量越高,马尾松人工林生物量越大。  相似文献   
92.
人胎肝细胞分泌的低分子抑瘤物对白血病细胞的抑制作用   总被引:4,自引:1,他引:3  
本工作证明了在胎儿组织中存在一类低分子天然肿瘤抑制物,它是胎儿组织细胞生成和分泌的,对瘤株细胞和原代白血病细胞有选择性抑制作用。初发期或复发期急性非淋巴细胞白血病患者的骨髓在体外液体培养条件下与肝细胞上清及其甲醇提取物共同孵育4d,可使所有病例的骨髓AML—CFU降低到不可检出的程度。因而,低分子天然抑瘤物是天然肿瘤免疫中的一个组成部分,它在肿瘤的诊断和治疗中有着深远的意义。  相似文献   
93.
聚球藻藻胆体-类囊体膜吸收光谱中有五个吸收峰,它们位于420nm,438nm,490nm,624nm 和678nm。放氧速率为161—179mol O2/mg Chl.hr.电镜照片中显示在类囊体膜上有大量藻胆体。  相似文献   
94.
为挖掘湿地松(Pinus elliottii)松脂合成相关的基因,对不同采脂期的木质部和针叶进行高通量转录组测序,与火炬松(Pinus taeda)参考基因组进行比对,共获得了68 211条unigenes,546 356 450条clean reads,平均比对率达90.21%。将不同时期木质部、木质部与针叶间进行两两对比,以P<0.05,|log2FoldChange|>1.0为标准来筛选差异基因,并进行GO和KEGG富集分析。结果表明,参与萜类物质合成的差异基因有133个,其中大部分富集在MEP途径,从差异基因中挑选8个产脂相关的候选基因进行RT-qPCR验证,确定HMGR、DXS、TPS、ABC转运蛋白基因与产脂存在关联性。通过转录组测序与分析,挖掘出133个参与松脂萜类物质合成相关的差异基因,其中萜烯合酶基因(TPS)和ABC转运基因在正调控萜类物质合成中发挥关键作用。  相似文献   
95.
Long non-coding RNAs (lncRNA) have an extensive role in the progression and chemoresistance of gastric cancer (GC). Deeply study the regulatory role of lncRNAs could provide potential therapeutic targets. The aim of this study is to explore the regulatory role of HOTAIR in the progression and oxaliplatin resistance of GC. The expression of HOTAIR in GC and cell lines were detected by using qRT-PCR. Cell proliferation and apoptosis were analysed by CCK-8, EdU incorporation and flow cytometry. Luciferase reporter assay was used to identify the interaction between HOTAIR and ABCG2 (ATP-binding cassette (ABC) superfamily G member 2, ABCG2) via miR-195-5p. The regulatory functions were verified by using molecular biology experiments. HOTAIR was significantly overexpressed in GC and associated with poor prognosis. Knock-down of HOTAIR inhibited the GC cells proliferation and oxaliplatin resistance, while overexpression of HOTAIR showed opposite functions. Further studies found that HOTAIR acted as a competing endogenous RNA (ceRNA) to absorb miR-195-5p and elevated the expression of ABCG2, which leads to resistance of GC cells to oxaliplatin. Taken together, our findings demonstrated that HOTAIR regulates ABCG2 induced resistance of GC to oxaliplatin through miR-195-5p signalling and illustrate the great potential of developing new therapeutic targets for GC patients.  相似文献   
96.
Genetic studies on attention have mainly focused on children with attention-deficit/hyperactivity disorder (ADHD), so little systematic research has been conducted on genetic correlates of attention performance and their potential brain mechanisms among healthy individuals. The current study included a genome-wide association study (GWAS, N = 1145 healthy young adults) aimed to identify genes associated with sustained attention and an imaging genetics study (an independent sample of 483 healthy young adults) to examine any identified genes' influences on brain function. The GWAS found that TTLL11 showed genome-wide significant associations with sustained attention, with rs13298112 as the most significant SNP and the GG homozygotes showing more impulsive but also more focused responses than the A allele carriers. A retrospective examination of previously published ADHD GWAS results confirmed an un-reported, small but statistically significant effect of TTLL11 on ADHD. The imaging genetics study replicated this association and showed that the TTLL11 gene was associated with resting state activity and connectivity of the somatomoter network, and can be predicted by dorsal attention network connectivity. Specifically, the GG homozygotes showed lower brain activity, weaker brain network connectivity, and non-significant brain-attention association compared to the A allele carriers. Expression database showed that expression of this gene is enriched in the brain and that the G allele is associated with lower expression level than the A allele. These results suggest that TTLL11 may play a major role in healthy individuals' attention performance and may also contribute to the etiology of ADHD.  相似文献   
97.
Shawurenine C ( 1a ) and D ( 1b ), a new pair of regioisomeric C19-diterpenoid alkaloids, and five known C19-diterpenoid alkaloids ( 2 – 6 ) were isolated from the aerial part of Delphinium shawurense W. T. Wang. The chemical structures of new compounds were established based on spectroscopic analyses: HR-ESI-MS, and 1D, 2D NMR spectroscopic data. The anti-inflammatory and cytotoxic activities of these diterpenoid alkaloids were also evaluated.  相似文献   
98.
Serine esterases (SEs) are hydrolases that catalyze the conversion of carboxylic esters into acids and alcohols. Lipases and carboxylesterases constitute two major groups of SEs. Although over a hundred of insect genomes are known, systematic identification and classification of SEs are rarely performed, likely due to large size and complex composition of the gene family in each species. Considering their key roles in lipid metabolism and other physiological processes, we have categorized 144 M. sexta SEs and SE homologs (SEHs), 114 of which contain a motif of GXSXG. Multiple sequence alignment and phylogenetic tree analysis have revealed 39 neutral lipases (NLs), 3 neutral lipase homologs (NLHs), 11 acidic lipases (ALs), 3 acidic lipase homologs (ALHs), a lipase-3, a triglyceride lipase, a monoglyceride lipase, a hormone-sensitive lipase, and a GDSL lipase. Eighty-three carboxylesterase genes encode 29 α-esterases (AEs), 12 AEHs (e.g., SEH4-1–3), 20 feruloyl esterases (FEs), 2 FEHs, 2 β-esterases (BEs), 2 integument esterases (IEs), 1 IEH, 4 juvenile hormone esterases, 2 acetylcholinesterases, gliotactin, 6 neuroligins, neurotactin, and an uncharacteristic esterase homolog. In addition to these GXSXG proteins, we have identified 26 phospholipases and 13 thioesterases. Expression profiling of these genes in specific tissues and stages has provided insights into their functions including digestion, detoxification, hormone processing, neurotransmission, reproduction, and developmental regulation. In summary, we have established a framework of information on SEs and related proteins in M. sexta to stimulate their research in the model species and comparative investigations in agricultural pests or disease vectors.  相似文献   
99.
为快速鉴定糜子(Panicum miliaceum)资源, 建立分子标记检测平台, 以272份山西糜子核心种质为研究材料, 利用85对简单重复序列(SSR)引物, 应用ID Analysis 4.0软件, 构建DNA分子身份证。结果表明, 对85对SSR引物进行筛选, 发现20对引物组合(RYW67、RYW53、RYW37、RYW65、RYW62、RYW77、RYW5、RYW49、RYW84、RYW19、RYW11、RYW40、RYW54、RYW28、RYW31、RYW7、RYW16、RYW8、RYW9和RYW18)可区分272份材料。共检测到等位变异(Na) 60个, 平均每个位点检出3个; Shannon多样性指数(I)为0.957 8 (RYW16)-1.096 7 (RYW5), 平均值为1.055 2; 多态性信息含量(PIC)为0.604 4 (RYW77)-0.753 0 (RYW37), 平均值为0.692 1。利用20对引物构建山西糜子核心种质的字符串、条形码和二维码DNA分子身份证, 可为种质身份标识和溯源提供实践路径。  相似文献   
100.
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