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船闸的耐久性一直是水利水电领域研究的重要课题,而船闸闸墙混凝土受过往船只的碰撞、摩擦容易受到破坏,形成擦痕,这不仅极大地影响到了船闸的耐久性,并影响其美观。通过对国内外现有部分工程材料的技术资料和使用情况的调研,选择具有环氧树脂和聚氨酯分子链段结构的特殊树脂为基体,初步制备出了CKC系列新型防护修补材料,并在三峡工程五级永久船闸现场进行了生产性科学试验研究。由于CKC系列新型防护修补材料特殊的分子结构,使它既具有环氧树脂硬度高、粘结性强的特点,又具有聚氨酯的韧性和耐磨性的特点。通过2次半年期与一年期的检测,闸墙修补的CKC材料基本完好无损。 相似文献
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Targeted chemotherapy has become the forefront for cancer treatment in recent years. The selective and specific features allow more effective treatment with reduced side effects. Most targeted therapies, which include small molecules, act on specific molecular targets that are altered in tumour cells, mainly in cancers such as breast, lung, colorectal, lymphoma and leukaemia. With the recent exponential progress in drug development, programmed cell death, which includes apoptosis and autophagy, has become a promising therapeutic target. The research in identifying effective small molecules that target compensatory mechanisms in tumour cells alleviates the emergence of drug resistance. Due to the heterogenous nature of breast cancer, various attempts were made to overcome chemoresistance. Amongst breast cancers, triple negative breast cancer (TNBC) is of particular interest due to its heterogeneous nature in response to chemotherapy. TNBC represents approximately 15% of all breast tumours, however, and still has a poor prognosis. Unlike other breast tumours, signature targets lack for TNBCs, causing high morbidity and mortality. This review highlights several small molecules with promising preclinical data that target autophagy and apoptosis to induce cell death in TNBC cells. 相似文献
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Pitt William R.; Goodfellow Julia M. 《Protein engineering, design & selection : PEDS》1991,4(5):531-537
Previous analysis of the distribution of experimental solventmolecule positions around amino acid side chains showed thatdistinct clustering occurred close to polar or charged atomsin proteins. We have used those data to predict likely solventpositions around proteins not used in our initial analysis.We envisage that this algorithm, AQUARIUS, will be useful forfinding solvent positions in electron density maps generatedby protein crystallography and as useful starting positionsfor solvent molecules in computer simulation studies of macromolecules. 相似文献
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Study of DNA Origami Dimerization and Dimer Dissociation Dynamics and of the Factors that Limit Dimerization 下载免费PDF全文
Miran Liber Toma E. Tomov Roman Tsukanov Yaron Berger Mary Popov Dinesh C. Khara Eyal Nir 《Small (Weinheim an der Bergstrasse, Germany)》2018,14(23)
Organizing DNA origami building blocks into higher order structures is essential for fabrication of large structurally and functionally diverse devices and molecular machines. Unfortunately, the yields of origami building block attachment reactions are typically not sufficient to allow programed assembly of DNA devices made from more than a few origami building blocks. To investigate possible reasons for these low yields, a detailed single‐molecule fluorescence study of the dynamics of rectangular origami dimerization and origami dimer dissociation reactions is conducted. Reactions kinetics and yields are investigated at different origami and ion concentrations, for different ion types, for different lengths of bridging strands, and for the “sticky end” and “weaving welding” attachment techniques. Dimerization yields are never higher than 86%, which is typical for such systems. Analysis of the dynamic data shows that the low yield cannot be explained by thermodynamic instability or structural imperfections of the origami constructs. Atomic force microscopy and gel electrophoresis evidence reveal self‐dimerization of the origami monomers, likely via blunt‐end interactions made possible by the presence of bridging strands. It is suggested that this mechanism is the major factor that inhibits correct dimerization and means to overcome it are discussed. 相似文献
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Cancer is a predominant cause of mortality all over the world. Lung, prostate, and colorectal cancer are the more frequent in men while breast and colorectal have a high incidence in women. Major progress aside, some cancers are still frequent and one major issue is improvements in detection methods. Imaging techniques have a major role, but inflammatory, tumoral markers and calculated scores may contribute to the assessment of prognosis. The erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and carcinoembryonic antigen cell adhesion molecule (CEACAM) have been used for decades and do not have a clear use for diagnosis or prognosis yet. The CEACAM family includes 12 human members, and some of them have a cluster differentiation (CD). CD66 may be an interesting indicator of disease severity. Beside interleukin-6 (IL-6), the high level of which is observed in patients with a high mortality rate, other cytokines IL-17A, IL-22, and transforming growth factor -β (TGF-β) are expressed at the tumor level. The detection of circulating tumor cells has been improved but is still of undetermined value. Circulating tumor DNA (ctDNA) was recently studied in CRC stage II patients and may be helpful for chemotherapy management. 相似文献