首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
Plasma Physics Reports - Results of experiments on a linear facility with a helicon plasma source operating at a frequency of 13.56 MHz and a power of up to 15 kW are reported. In the experiments,...  相似文献   

2.
R. F. Ohlke  J. J. Scales 《CMAJ》1953,68(3):260-261
  相似文献   

3.
4.
This paper investigates the design of four different configurations of plasma reflectarrays. The results provide insight into different radiation characteristics of plasma reflectarrays. The proposed unit cell consists of a cubic glass box filled with argon gas energized with applied AC voltage. The reflectarray reflection coefficient phase variation is achieved by varying the plasma frequency of the energized gas. Four plasma reflectarrays for satellite applications at 12 GHz are proposed (centre feed centre beam, centre feed offset beam, offset feed centre beam, and finally, offset feed offset beam). The finite integration technique is used to analyse the plasma reflectarray.  相似文献   

5.
Fibronectin (FN) is a glycoprotein (disulfite-bonded dimer of 200 to 220 Kd submits) found in a soluble form in blood (concentration 250--500 microg/ml), it can be removed from it by cryoprecipitation and affinity chromatography on gelatin or heparin-agarose. It is also found in an insoluble fibrillar form as a component of connective tissue matrix like collagen, proteoglycans... FN fundamentally forms molecular complexes with collagen, fibrinogen or fibrin, heparin, activated factor XIII, bacteria, cellular membranes..., these various proteins binding with now well known functional "domains" on subunits. Thus FN mediates adhesion of cells to cells as well to biomaterials or tissue, cell migration and chemotactic activity, tissue stromal organization... The transformed cultured cells in presence of oncogen virus loose ability to secrete FN which contribute to their invasive tendency. FN also interacts with hemostatic and fibrinolytic systems, as component of the subendothelium (secreted, like Willbrand factor, by endothelial cells) and of platelet alpha-granules released by stimulated platelets. FN could then provoke platelet spreading on the subendothelium surface after collagen-platelet adhesion, triggered by Willebrand factor, has happened. FN is a part of the fibrinous clot. It participates in anchorage of the clot to subendothelium and mediates its colonisation by fibroblasts, first step to wound reparation. Lastly FN probably has an important role in organism defence. It acts as a non-immunological opsonin, promoting phagocytosis by RES macrophages of bacteria, cellular or fibrin fragments, immune complexes... present in blood. Plasmatic FN concentration is strongly decreased in several ill patients following major trauma, extensive burns, shock, sepsis, with or not evidence of DIVC, of respiratory distress... SABA and various other authors have obtained good results after injections of FN (as cryoprecipitates or concentrated fractions). It is yet necessary to confirm therapeutic role of FN.  相似文献   

6.
7.
目的:研究单采血浆中两种耗材-管路和贮存袋,材料和方法:以压力监测器接头(DPM)、导管流量和贮存袋耐寒性的研究关键。并与国内外同类产品或材料作比较,结果:DPM必须具有适宜的透气性(感应时间≤2s)、阻血性(能耐受40Kpa,40s),滤除率(0.5um粒子,≥90%),导管流量的准确性(与机器设定值误差<5%),稳定性(采集过程中流量误差<5%)可通过控制导管内径(3.08-3.24mm)和选择弹性PVC材料来解决,贮存袋选用耐寒PVC料。扫描电镜证实韧性断裂。结论:研制成的管路和PCS^2机器适配能取代进口同类产品,研制的贮存袋能低温保存血浆,破损率小于2‰。  相似文献   

8.
Background Elevated plasma homocysteine and amyloid β (Aβ) have been associated with Alzheimer’s disease (AD). We investigated the cross-sectional association between these biomarkers. Methods We used linear regression to relate plasma homocysteine and Aβ adjusting for age, gender, creatinine, APOE-ε4, and ethnic group in 327 persons aged 78 ± 6.6 years. Results Plasma homocysteine correlated with age, serum creatinine, plasma Aβ40 and Aβ42, and was inversely correlated with serum vitamin B12, and folate. Aβ42, but not Aβ40, was related to later development of dementia. Homocysteine was related to higher Aβ40 levels (coefficient = 2.0; P < 0.0001) and this association was attenuated after adjustment for creatinine (coefficient = 1.0; P < 0.0001). The crude association between homocysteine and Aβ42 was weaker (coefficient = 0.5; P = 0.01) and became non-significant after adjustment for creatinine (coefficient = 0.4; P = 0.06). These associations were unrelated to ethnicity, the presence of APOE-ε4 or dementia. Analyses by quartiles of homocysteine showed that these association were driven primarily by the fourth quartile. Conclusions Plasma homocysteine is directly related to Aβ40. The association with Aβ42 is not significant. These results seem to indicate that homocysteine is related to aging but not specifically to AD. Special issue dedicated to John P. Blass.  相似文献   

9.
Plasma Physics Reports - Plasma bunches with the characteristic size of approximately 1 mm and electron density larger than 1019 cm–3 are registered by the laser sounding methods on a...  相似文献   

10.
Plasma Physics Reports - Conditions of substrate-free syntheses of graphene and graphene-based systems based on conversion of liquid and gaseous carbon precursors in helium, nitrogen, and argon...  相似文献   

11.
12.
Plasma und Zelle     
Ohne Zusammenfassung  相似文献   

13.
The association of tubulin with the plasma membrane comprises multiple levels of penetration into the bilayer: from integral membrane protein, to attachment via palmitoylation, to surface binding, and to microtubules attached by linker proteins to proteins in the membrane. Here we discuss the soundness and weaknesses of the chemical and biochemical evidence marshaled to support these associations, as well as the mechanisms by which tubulin or microtubules may regulate functions at the plasma membrane.  相似文献   

14.
Procurement and processing of human plasma for fractionation of therapeutic proteins or biological medicines used in clinical practice is a multi-billion dollar international trade. Together the private sector and public sector (non-profit) provide large amounts of safe and effective therapeutic plasma proteins needed worldwide. The principal therapeutic proteins produced by the dichotomous industry include gamma globulins or immunoglobulins (including pathogen-specific hyperimmune globulins, such as hepatitis B immune globulins) albumin, factor VIII and Factor IX concentrates. Viral inactivation, principally by solvent detergent and other processes, has proven highly effective in preventing transmission of enveloped viruses, viz. HBV, HIV, and HCV.  相似文献   

15.
16.
The fractionation of blood plasma yields a number of therapeutic proteins which together constitute a billion dollar world-wide market. Conventional plasma fractionation procedures are being replaced by more sophisticated chromatographic techniques. The application of genetic engineering and these new downstream processing techniques is likely to lead to improved products of higher purity and stability, with less likelihood of contamination by viruses and at lower cost per therapeutic dose.  相似文献   

17.
18.
Peptide identifications of high probability from 28 LC-MS/MS human serum and plasma experiments from eight different laboratories, carried out in the context of the HUPO Plasma Proteome Project, were combined and mapped to the EnsEMBL human genome. The 6929 distinct observed peptides were mapped to approximately 960 different proteins. The resulting compendium of peptides and their associated samples, proteins, and genes is made publicly available as a reference for future research on human plasma.  相似文献   

19.
20.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号