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161.
Sali Anies Vincent Jallu Julien Diharce Tarun J. Narwani Alexandre G. de Brevern 《International journal of molecular sciences》2022,23(2)
Integrin αIIbβ3, a glycoprotein complex expressed at the platelet surface, is involved in platelet aggregation and contributes to primary haemostasis. Several integrin αIIbβ3 polymorphisms prevent the aggregation that causes haemorrhagic syndromes, such as Glanzmann thrombasthenia (GT). Access to 3D structure allows understanding the structural effects of polymorphisms related to GT. In a previous analysis using Molecular Dynamics (MD) simulations of αIIb Calf-1 domain structure, it was observed that GT associated with single amino acid variation affects distant loops, but not the mutated position. In this study, experiments are extended to Calf-1, Thigh, and Calf-2 domains. Two loops in Calf-2 are unstructured and therefore are modelled expertly using biophysical restraints. Surprisingly, MD revealed the presence of rigid zones in these loops. Detailed analysis with structural alphabet, the Proteins Blocks (PBs), allowed observing local changes in highly flexible regions. The variant P741R located at C-terminal of Calf-1 revealed that the Calf-2 presence did not affect the results obtained with isolated Calf-1 domain. Simulations for Calf-1 + Calf-2, and Thigh + Calf-1 variant systems are designed to comprehend the impact of five single amino acid variations in these domains. Distant conformational changes are observed, thus highlighting the potential role of allostery in the structural basis of GT. 相似文献
162.
重水作为反应堆的慢化材料,其浓度直接影响反应堆的安全和性能。为研究其重水浓度与吸光度间的关系曲线类型,基于朗伯-比尔定律,从理论上推导出液态重水中某种水分子的红外吸收峰分别与0~2种其他水分子的红外吸收峰发生重叠时重水浓度与吸光度间的关系式,分情况对二者之间的关系曲线类型进行讨论。采用傅里叶变换红外光谱仪,测得浓度为0.015%~99.98%(摩尔比)的重水标准样品吸收光谱,对重水浓度和吸光度间的关系曲线类型进行验证,理论推导与实际吻合。研究表明,一般情况下,宽浓度范围内,重水浓度与吸光度间的关系曲线类型为二次曲线;窄浓度范围内,关系曲线类型为线性。特殊情况下,吸光度为定值或关系曲线类型为线性。 相似文献
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164.
Zhen Zeng Tong Lyu Xin Jia Yue Chen Yingmin Lyu 《International journal of molecular sciences》2022,23(8)
During the growth cycle of lilies, assimilates undergo a process of accumulation, consumption and reaccumulation in bulbs and are transported and allocated between aboveground and underground organs and tissues. The sink–source relationship changes with the allocation of assimilates, affecting the vegetative growth and morphological establishment of lilies. In this study, the carbohydrate contents in different tissues of five critical stages during lily development were measured to observe the assimilates allocation. The results showed bulbs acted as the main source to provide energy before the budding stage (S3); after the flowering stage (S4), bulbs began to accumulate assimilates as a sink organ again. During the period when the plant height was 30cm with leaf-spread (S2), leaves mainly accumulated assimilates from bulbs through the symplastic pathway, while when leaves were fully expanded, it transformed to export carbohydrates. At the S4 stage, flowers became a new active sink with assimilates influx. To further understand the allocation of assimilates, 16 genes related to sugar transport and metabolism (ST genes) were identified and categorized into different subfamilies based on the phylogenetic analysis, and their protein physicochemical properties were also predicted. Tissue-specific analysis showed that most of the genes were highly expressed in stems and petals, and it was mainly the MST (monosaccharide transporter) genes that were obviously expressed in petals during the S4 stage, suggesting that they may be associated with the accumulation of carbohydrates in flowers and thus affect flower development process. LoSWEET14 (the Sugar will eventually be exported transporters) was significantly correlated with starch in scales and with soluble sugar in leaves. Sugar transporters LoHXT6 and LoSUT1 were significantly correlated with soluble sugar and sucrose in leaves, suggesting that these genes may play key roles in the accumulation and transportation of assimilates in lilies. In addition, we analyzed the expression patterns of ST genes under different abiotic stresses, and the results showed that all genes were significantly upregulated. This study lays a solid foundation for further research on molecular mechanism of sink–source change and response to abiotic stresses in lilies. 相似文献
165.
钢管混凝土粘结滑移本构关系理论研究 总被引:1,自引:0,他引:1
钢管混凝土中钢管与混凝土之间的粘结强度和粘结滑移备受关注.国内外对钢管混凝土粘结滑移的研究较多,但主要侧重于粘结强度的研究,而对粘结滑移本构关系的研究相对较少;而且目前钢材和混凝土的本构关系均已经比较明确,钢管混凝土粘结滑移的本构方程尚无定论.从理论上推导了钢管与混凝土粘结滑移的本构关系,讨论了钢管混凝土粘结滑移本构关系的建立方法.为进一步研究钢管混凝土的粘结滑移本构关系提供了理论依据. 相似文献
166.
为了解医用防护服研究进展,对医用防护服的时空关系、合作关系、共现关系和共被引进行了研究.以文献计量和知识图谱法为研究方法,CiteSpace为分析工具,对2006年1月1日—2020年10月30日在Web of Science上发表的380条文献进行可视化分析.研究发现:在时间线上有关医用防护服的发展呈现螺旋上升的趋势... 相似文献
167.
采用DSC和~(13)C-NMR等方法,将玻璃化温度(T_g)和溶聚丁苯橡胶(S-SBR)的序列结构关联起来,并以此为判据,将具有不同序列结构的S-SBR分为无规,短嵌段和长嵌段三种类型。T_g和序列分布对S-SBR性能的影响基本相似,硬度、拉伸强度、300%定伸应力和永久变形基本恒定,分别为72±2度、22±1.5MPa,11.0—13.0MPa和<12%;伸长率λ=-5627-15.8×T_g,弹性E=27.9-0.197T_g;分别求得无规型和短嵌段型S-SBR的λ、E与序列分布的线性关联式。 相似文献
168.
储层"四性"关系是指储层的岩性、物性、电性和含油气性之间的关系。本文通过结合测井、录井、岩心、分析化验和岩电资料对渭北油田延长组储层四性关系进行了综合分析研究,明确了其储层四性之间的关系,进而为油层解释和储层评价奠定了基础。 相似文献
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170.