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Rehana Zi Madeeha Riaz Nida ul nasir Farhat Saleemi Zora Kayani Safia Anjum Farooq Bashir Tousif Hussain 《自然科学进展(英文版)》2016,26(1):41-48
The main objective of the study was to control the degradation rate of material at a higher degradation rate improving the chemical stability of the material. Ta is known to have good chemical resistance, biocompatibility and show no adverse biological response. In the present study, SiO2–Na2O–CaO–P2O5 bioceramics with different Ta2O5 contents was prepared by solid state sintering method at 1000 °C. The as-sintered ceramics were subjected to immersion studies in stimulated body fluid (SBF) for 21 days under static condition and characterized by XRD, FTIR, SEM, and AAS. The findings of the research indicate that the addition of Ta2O5 controlled degradability, and all samples showed sufficient bioactivity. 相似文献
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Chérine Bechara Manjula Pallerla Fabienne Burlina Françoise Illien Sophie Cribier Sandrine Sagan 《Cellular and molecular life sciences : CMLS》2015,72(4):809-820
Among non-invasive cell delivery strategies, cell-penetrating peptide (CPP) vectors represent interesting new tools. To get fundamental knowledge about the still debated internalisation mechanisms of these peptides, we modified the membrane content of cells, typically by hydrolysis of sphingomyelin or depletion of cholesterol from the membrane outer leaflet. We quantified and visualised the effect of these viable cell surface treatments on the internalisation efficiency of different CPPs, among which the most studied Tat, R9, penetratin and analogues, that all carry the N-terminal biotin-Gly4 tag cargo. Under these cell membrane treatments, only penetratin and R6W3 underwent a massive glycosaminoglycan (GAG)-dependent entry in cells. Internalisation of the other peptides was only slightly increased, similarly in the absence or the presence of GAGs for R9, and only in the presence of GAGs for Tat and R6L3. Ceramide formation (or cholesterol depletion) is known to lead to the reorganisation of membrane lipid domains into larger platforms, which can serve as a trap and cluster receptors. These results show that GAG clustering, enhanced by formation of ceramide, is efficiently exploited by penetratin and R6W3, which contains Trp residues in their sequence but not Tat, R9 and R6L3. Hence, these data shed new lights on the differences in the internalisation mechanism and pathway of these peptides that are widely used in delivery of cargo molecules. 相似文献
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Rául Espejo 《Systemic Practice and Action Research》1993,6(5):517-525
This paper offers insights about the role of complexity in the interaction between a social system and its environment. For this purpose it clarifies, from the viewpoint of the individuals constituting these social systems, the complementarity between their domain of observation, or informational domain, and their domain of action, or operational domain. 相似文献
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Ribot JC debarros A Silva-Santos B 《Cellular and molecular life sciences : CMLS》2011,68(14):2345-2355
T cell activation requires the integration of signals that arise from various types of receptors. Although TCR triggering
is a necessary condition, it is often not sufficient to induce full T-cell activation, as reflected in cell proliferation
and cytokine secretion. This has been firmly demonstrated for conventional αβ T cells, for which a large panel of costimulatory
receptors has been identified. By contrast, the area remains more obscure for unconventional, innate-like γδ T cells, as the
literature has been scarce and at times contradictory. Here we review the current state of the art on the costimulatory requirements
of γδ T cell activation. We highlight the roles of members of the immunoglobulin (like CD28 or JAML) or tumour necrosis factor
receptor (like CD27) superfamilies of coreceptors, but also of more atypical costimulatory molecules, such as NKG2D or CD46.
Finally, we identify various areas where our knowledge is still markedly insufficient, hoping to provoke future research on
γδ T cell costimulation. 相似文献
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H. M. Shifa ul Haq Arnaud John KOMBE KOMBE Ayesha Zahid Momal Babar Weihong Zeng Hongliang He Tengchuan Jin 《中国科学技术大学学报》2022,52(6):1-1-1-10
The coronavirus disease 2019 (COVID-19) epidemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has caused millions of deaths worldwide. Therefore, it is critical to understand the biological basis of SARS-CoV-2 to develop novel approaches to control its spread. The SARS-CoV-2 nucleocapsid (N) protein is an important diagnostic and potent therapeutic target of the disease, as it is involved in numerous important functions in the viral life cycle. Several studies have explained the structural and functional aspects of the SARS-CoV-2 N protein. This review summarizes the currently available data on the evolutionarily conserved N protein of SARS-CoV-2 by providing detailed information on the structural and multifunctional characteristics of the N protein. 相似文献
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