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1.
Reviews the book, Independent living for physically disabled people by Nancy M. Crewe, Irving Kenneth Zola, and Associates (1983). As stated by the authors, one of their goals in writing this text is to bring together a substantial portion of the rapidly growing body of independent living (IL) knowledge, some of which is relatively inaccessible. More importantly, the authors state their wish to present this knowledge in a way that will communicate the challenge and promise of the IL movement to their intended audience, whom they identify as professionals and students already in the field and in closely related fields, as well as disabled individuals. Generally speaking, this book succeeds in meeting its authors' stated objectives. A particularly important reason for this success may be the fact that the book presents the reader with a comprehensive view of the IL movement from a variety of vantage points—historical and cultural, urban and rural, domestic and international, disabled and nondisabled—as well as from numerous professional standpoints. Independent Living for Physically Disabled People is a well-organized and clearly written text that satisfactorily articulates the growing visibility of the IL movement. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

2.
The field of neutron inelastic scattering has probably been developed to the stage where it can begin to help the biologist. Because essentially no experimental data have been obtained, it is difficult either to draw conclusions or to make forecasts except on the basis of general hypotheses. It seems likely, however, that the next stage is up to biologists. After reviewing those biological problems in which molecular dynamics might play an important role, they should suggest specimens of interest which can give inelastic peaks with existing spectrometers operating with 5 to 10-A neutrons at angles greater than 5degrees and with resolutions of approximately 50 mueV. These specimens may involve molecules slightly smaller and more mobile than some biologists would like, but a successful outcome might lead to the development of spectrometers capable of working in a more satisfactory range. In this event the return may well prove rewarding to the biologists.  相似文献   

3.
This review is in support of the development of selective, reproducible and validated capillary electrophoretis (CE) methods. Focusing on pharmaceutical and biological applications, the successful use of CE is demonstrated by more than 800 references, mainly from 1994 until 1998. Approximately 80 recent reviews have been catalogued. These articles sum up the existing strategies for method development in CE, especially in the search for generally accepted concepts, but also looking for new, promising reagents and ideas. General strategies for method development were derived not only with regard to selectivity and efficiency, but also with regard to precision, short analysis time, limit of detection, sample pretreatment requirements and validation. Standard buffer recipes, surfactants used in micellar electrokinetic capillary chromatography (MEKC), chiral selectors, useful buffer additives, polymeric separation media, electroosmotic flow (EOF) modifiers, dynamic and permanent coatings, actions to deal with complex matrices and aspects of validation are collected in 20 tables. Detailed schemes for the development of MEKC methods and chiral separations, for optimizing separation efficiency, means of troubleshooting, and other important information for key decisions during method development are given in 19 diagrams. Method development for peptide and protein separations, possibilities to influence the EOF and how to stabilize it, as well as indirect detection are considered in special sections.  相似文献   

4.
The cellular uptake of liposomes is generally believed to be mediated by adsorption of liposomes onto the cell surface and subsequent endocytosis. This report examines the effect of liposome surface charge on liposomal binding and endocytosis in two different cell lines: a human ovarian carcinoma cell line (HeLa) and a murine derived mononuclear macrophage cell line (J774). The large unilamellar liposomes were composed of 1, 2-dioleolyl-sn-glycero-3-phosphatidylcholine with and without the addition of either a positively charged lipid, 1, 2-dioleoyl-3-dimethylammonium propanediol (DODAP), or a negatively charged lipid, 1,2-dioleolyl-sn-glycero-3-phosphatidylserine. In some experiments 5 mol % of the anionic PEG2000-PE or a neutral PEG lipid of the same molecular weight was added. HeLa cells were found to endocytose positively charged liposomes to a greater extent than either neutral or negatively charged liposomes. This preference was not lipid-specific since inclusion of a cationic cyanine dye, DiIC18(3), to impart positive charge in place of DODAP resulted in a similar extent of endocytosis. In contrast the extent of liposome interaction with J774 cells was greater for both cationic and anionic liposomes than for neutral liposomes. The greater uptake of positively charged liposomes by HeLa cells was also observed with sterically stabilized liposomes (PEG liposomes). Although the overall amount of endocytosis for all the PEG liposomes examined was attenuated relative to conventional liposomes, the extent of endocytosis was greatest for positively charged PEG liposomes, whereas negatively charged PEG2000-PE liposomes were hardly endocytosed by the HeLa cells. Incorporation of a neutral PEG lipid into liposomes permits the independent variation of liposome steric and electrostatic effects in a manner that may allow interactions with cells of the reticuloendothelial system to be minimized, yet permit strong interactions between liposomes and proliferating cells.  相似文献   

5.
The oxidation performance of two nickel base superalloys, Inconel 738 and Rene 80, was determined by isothermal static oxidation test at 900°C. The metrics used to evaluate performance were weight gain per unit area as a function of time, oxide scale thickness, qualitative elemental mapping and calculation of the parabolic rate constant for each. It was found that Inconel 738 performed notably better than Rene 80, with the rate constants being KP?=?2·26×10?12 g2 cm?4 s?1 for Inconel 738 and KP?=?3·85×10?12 g2 cm?4 s?1 for Rene 80. This poorer performance of Rene 80 is attributed to lower amounts of chromium and aluminium, which have been shown to have a positive effect on oxidation performance, and higher amounts of titanium, which has shown to be detrimental. The oxidation results were then used in a new method of evaluating the efficacy of individual elements on overall oxidation behaviour. This method is based on the thermodynamic Gibbs free energy of the oxide and the amounts of the various oxide forming elements present in the alloys. Both alloys were found to exhibit scale growth consisting of a dense outer scale of chromia and a discontinuous inner subscale of alumina, matching predictions for the relative amounts of chromium and aluminium in each.

On a déterminé le comportement à l’oxydation de deux superalliages à base de nickel, Inconel 738 et René 80, par un essai d’oxydation statique isotherme à 900°C. Les mesures utilisées dans l’évaluation du comportement incluaient le gain de poids par unité de surface en fonction du temps, l’épaisseur de l’écaille d’oxyde, la cartographie qualitative des éléments et le calcul de la constante de vitesse parabolique pour chacun. On a trouvé que l’Inconel 738 avait un rendement particulièrement meilleur que celui de René 80, les constantes de vitesse étant de Kp?=?2·26×10?12 g2 cm?4 s?1 pour l’Inconel 738 et de Kp?=?3·85×10?12 g2 cm?4 s?1 pour René 80. On attribue le rendement moins bon de René 80 aux plus petites quantités en chrome et en aluminium, qui ont un effet positif sur le comportement d’oxydation, et aux quantités plus élevées de titane, qui est nuisible. On a ensuite utilisé les résultats d’oxydation dans une nouvelle méthode d’évaluation de l’efficacité d’éléments individuels sur le comportement global d’oxydation. Cette méthode est basée sur l’énergie libre thermodynamique de Gibbs de l’oxyde et sur les quantités des divers éléments favorisant la formation d’oxyde, qui sont présents dans les alliages. On a trouvé que les deux alliages exhibaient une croissance d’écaille qui consistait en une écaille extérieure dense d’oxyde de chrome et en une sous-écaille interne discontinue d’oxyde d’aluminium, coïncidant avec les prédictions des quantités relatives en chrome et en aluminium dans chacun des alliages.  相似文献   

6.
Synthetic glycolipids are of interest for their biological applications requiring interactions with membrane proteins. Depending on their structures, new series of glycolipids have applications in extraction of membrane proteins or medical applications as mimics of natural ligands of proteins.  相似文献   

7.
A comparison was made between the murine anti-MUC1 antibody BC2 (which reacts with the peptide epitope APDTR) and the "humanised" antibody hCTMO1 from CellTech, which reacts with the MUC1 epitope RPAP. Preliminary studies demonstrated that hCTMO1 was a "good" antibody whereas BC2 was not. Various parameters were determined and conclusions reached. (a) Affinity: the affinity of hCTMO1 was 2.60 x 10(7) M(-1) and that of BC2 was 1.36 x 10(7) M(-1); we did not consider these numbers to be substantially different, although hCTMO1 was clearly of higher affinity than BC2. (b) On/off rate at 4 degrees C: both antibodies bound effectively to the MUC-1 transfectant MOR5-CF2; the association rate for hCTMO1 was 3.8 times that of BC2 and the dissociation rate for BC2 was twice as fast as that of hCTMO1. (c) On/off rates at 37 degrees C: at 37 degrees C the association rate for hCTMO1 was greater than that of BC2. (d) Internalization: hCTMO1 was also more efficient at internalising bound antibody; 70% of bound hCTMO1 was internalised, whilst 6% of bound BC2 was internalised. From these studies it was clear that, while hCTMO1 was of similar affinity to BC2, the faster uptake and internalisation and lower off rate indicated that it was likely to be a superior antibody; this was proven in vivo. (e) Localisation: hCTMO1 bound much better in vivo than BC2 (68% compared to 28%). (f) Therapeutic experiments: BC2-idarubicin conjugates were essentially ineffective in eradicating tumours in mice whereas hCTMO1-idarubicin had a dramatic effect on breast cancer tumour cells growing in mice. We conclude that the simple measurements on/off rates and internalisation at 37 degrees C are the most important parameters to use to determine antibody effectiveness, prior to embarking on clinical studies.  相似文献   

8.
The structure and catalytic properties of the enzyme (E) chlorocatechol dioxygenase (CCD) adsorbed on a citrate-reduced silver colloid are analyzed by surface-enhanced resonance Raman spectroscopy (SERRS). This is the first SERRS study of a non-heme metalloenzyme. It is demonstrated that the native conformation of CCD is retained in the adsorbed state by comparison of resonance Raman scattering (RRS) from CCD in solution with SERRS from CCD adsorbed on the silver colloid. Both spectra show clear evidence of vibrational bands typical of iron-tyrosinate proteins. Furthermore, it is demonstrated that adsorbed CCD retains 60-85% of its enzymatic activity in the reaction of catechol substrate (S) with O2 to give the dioxygenated product (P) cis,cis-muconate. This is accomplished by enzyme assays of Ag-adsorbed CCD and comparison of the SERRS of Ag-adsorbed enzyme-substrate (ES) complex under anaerobic conditions with that of Ag-adsorbed ES in the presence of dioxygen. The SERRS difference spectrum, ES(aerobic)--ES(anaerobic), shows clear evidence for the appearance of the vibrational modes of adsorbed product. The analogous SERR difference spectroscopy experiment is also carried out for the enzyme-inhibitor (EI) complex of CCD with tetrachlorocatechol (TCC). Slow turnover of CCD-TCC is observed by SERRS on exposure to dioxygen which is consistent with the slow rate of turnover of TCC by CCD in solution.  相似文献   

9.
邢云  王贵芳 《冶金分析》2013,33(11):6-11
在超声波辐射作用下,以非质子溶剂二甲亚砜为溶剂,制备了新型吸附剂交联羧甲基壳聚糖。利用X-射线光电子能谱、傅里叶红外光谱等分析手段对样品进行了测试和表征。以Pb2+、Cd2+和Co2+为吸附对象,考察了溶液初始浓度、吸附时间、酸度等因素对吸附过程的影响。等温线实验表明Langmuir吸附模型适合模拟金属离子在交联羧甲基壳聚糖表面的吸附过程,说明金属离子在交联羧甲基壳聚糖表面的吸附为单分子层吸附,交联羧甲基壳聚糖对Pb2+、Cd2+和Co2+的最大吸附容量分别为282.49mg/g、328.95mg/g和134.41mg/g。动力学实验表明,准二级方程适合描述此吸附过程。  相似文献   

10.
11.
Recent advances in nuclear magnetic resonance (NMR) methodology and improvements in high-field NMR instrumentation have generated a new wave of research interests in the application of solid-state NMR to the study of quadrupolar nuclei. These developments now permit increasingly complex biological systems to be probed by quadrupolar NMR. In this review I describe a few recent developments in NMR studies of quadrupolar nuclei and demonstrate the potential of solid-state quadrupolar NMR in the study of biological systems. In particular, I discuss the application of solid-state NMR of (17)O, 67Zn, 59Co, 23Na, and 39K nuclei with a prognosis for future work.  相似文献   

12.
以Ca(OH)2和H3PO4为反应物,通过溶胶-凝胶法制备了羟基磷灰石(HA)粉体;用机械混合法制备了304L不锈钢包覆HA粉体;用热压技术制备了纯HA陶瓷材料及HA/304L不锈钢复合材料.1050℃热压烧结后的HA/25vol.%304L复合材料的断裂韧性为2.92 MPa·m1/2,优于纯HA材料(断裂韧性为0.98 MPa·m1/2).显微组织的观察表明,304L不锈钢在材料中呈网状分布.网状分布的金属相能够通过桥接机制对HA基体中的裂纹扩展起到很好的阻碍作用.  相似文献   

13.
PURPOSE: To compare the analgesic efficacy and side effects of tramadol vs tramadol and droperidol for post-operative patient-controlled analgesia (PCA). METHODS: Randomised, double-blind study. Thirty-four patients undergoing elective colorectal or head and neck surgery were allocated to Group 1 (n = 18, PCA bolus 10 mg tramadol) or Group 2 (n = 16, PCA bolus 10 mg tramadol + 0.1 mg droperidol). Anaesthesia was induced with fentanyl and thiopentone and maintained with O2, N2O plus enflurane or isoflurane with iv morphine at doses decided by the attending anaesthetists. Muscle relaxation was achieved with atracurium or vecuronium. Patients were observed four-hourly for pain using an 11-point verbal rating scale (VRS). Nausea and vomiting, and sedation were assessed using four-point scales post-operatively. Vital signs, request for rescue anti-emetic and analgesic, and overall satisfaction were recorded. RESULTS: The mean nausea scores were lower in Group 2 (1.00 +/- 1.33 vs 0.06 +/- 0.25 at 0-8 hr, 1.22 +/- 1.93 vs 0.06 +/- 0.25 at 8-16 hr, P < 0.01; 0.81 +/- 1.68 vs 0 at 32-40 hr, P < 0.05; Group 1 vs Group 2). The vomiting scores were also lower (0.50 +/- 1.04 vs 0 at 0-8 hr, 0.67 +/- 1.50 vs 0, at 8-16 hr, P < 0.05; Group 1 vs Group 2). Seven (39%) patients in Group 1, but none in Group 2 requested rescue anti-emetic (P < 0.01). There were no differences in VRS, sedation score, overall satisfaction or vital signs. CONCLUSION: Tramadol and droperidol combination is superior to tramadol alone for post-operative PCA. It provides a similar quality of analgesia with less nausea and vomiting and without an increase in sedation.  相似文献   

14.
The circumsporozoite (CS) protein of malaria parasites (Plasmodium) covers the surface of sporozoites that invade hepatocytes in mammalian hosts and macrophages in avian hosts. CS genes have been characterized from many Plasmodium that infect mammals; two domains of the corresponding proteins, identified initially by their conservation (region I and region II), have been implicated in binding to hepatocytes. The CS gene from the avian parasite Plasmodium gallinaceum was characterized to compare these functional domains to those of mammalian Plasmodium and for the study of Plasmodium evolution. The P. gallinaceum protein has the characteristics of CS proteins, including a secretory signal sequence, central repeat region, regions of charged amino acids, and an anchor sequence. Comparison with CS signal sequences reveals four distinct groupings, with P. gallinaceum most closely related to the human malaria Plasmodium falciparum. The 5-amino acid sequence designated region I, which is identical in all mammalian CS and implicated in hepatocyte invasion, is different in the avian protein. The P. gallinaceum repeat region consists of 9-amino acid repeats with the consensus sequence QP(A/V)GGNGG(A/V). The conserved motif designated region II-plus, which is associated with targeting the invasion of liver cells, is also conserved in the avian protein. Phylogenetic analysis of the aligned Plasmodium CS sequences yields a tree with a topology similar to the one obtained using sequence data from the small subunit rRNA gene. The phylogeny using the CS gene supports the proposal that the human malaria P. falciparum is significantly more related to avian parasites than to other parasites infecting mammals, although the biology of sporozoite invasion is different between the avian and mammalian species.  相似文献   

15.
Short chain fatty acids (SCFAs) stimulate electroneutral sodium absorption by activation of apical Na/H exchange in colonocytes. It is often assumed that activation of Na/H exchange is via an intracellular acidification caused by SCFA uptake. These lecture notes review shortcomings in this model of SCFA-stimulated sodium absorption, revealed by recent reports in the literature. This is supplemented by information generated in our laboratory using both a tissue culture model of colonocytes (HT29-C1 cells) and a native tissue preparation (mouse distal colonic mucosa). In both preparations, evidence suggests that physiologic SCFA gradients may generate pH heterogeneity in aqueous microdomains near the plasma membrane of colonocytes. Finally, direct observation of such extracellular microdomains with confocal microscopy is used to support a new model, in which pH microdomains play an important role in regulating both SCFA fluxes and sodium absorption.  相似文献   

16.
17.
Haemophiliacs, until recently, have been at risk of hepatitis B and C infection. Substantial numbers of patients remain persistently infected. Several lines of evidence suggest that these diseases will cause considerable morbidity unless therapy can successfully reduce viraemia and prevent disease progression. Cessation of viral replication may prevent progression to hepatic fibrosis.  相似文献   

18.
采用红外光谱、X射线光电子能谱、接触角测定等方法对添加羧甲基纤维素钠的原矿压球所得含碳球块强度提高机理进行了研究.发现黏结剂羧甲基纤维素钠中羧基(—COOH)和羟基(—OH)在原矿颗粒表面产生了化学吸附作用,使矿石颗粒表面的亲水性下降;而羧甲基纤维素钠中有机碳链与煤粒表面作用,使煤的疏水性下降.原矿和煤粒依靠羧甲基纤维素钠高分子有机链结合起来,通过黏结剂颗粒间的黏附能力形成具有一定强度的\  相似文献   

19.
Reviews the book, Psychological concepts and biological psychiatry by Peter Zachar (see record 2000-16870-000). Almost from the very beginning of its disciplinary history clinical psychology has sought to align itself philosophically and methodologically with the natural sciences, particularly medicine and neurology. Contradicting the common-place assumption that common sense or folk psychology has been proven uninformative and futile, Zachar provides explicit philosophical and psychological arguments that demonstrate why such accounts are not only vital to proper scientific explanation but inevitable as well. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

20.
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