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791.
A chimera HIV-1/HIV-2 envelope sequence composed of multiple conserved immunodominant epitopes of HIV-1 envelope protein (HIV-1 IIIB: env482-518 + env548-675) and the HIV-2 gp36 immunodominant epitope (env592-603), was constructed and directly over-expressed in E. coli by using a prokaryotic translation initiation sequence contained within the gene of HIV-1 envelope. The recombinant product was purified and applied in antibody-screening assay. The purified chimera antigen reacted with all the thirty-eight HIV-1 positive serum samples, the two HIV-2 serum samples, and had no cross-reaction with all the eighty-eight normal healthy serum sample. The results indicated that this recombinant chimera HIV-1/HIV-2 envelope protein could be useful for diagnostic purposes of HIV infection. 相似文献
792.
Balzano Q. Bergeron J.A. Cohen J. Osepchuk J.M. Petersen R.C. Roszyk L.M. 《Electromagnetic Compatibility, IEEE Transactions on》1995,37(2):183-191
In response to reports of alleged health effects associated with the use of hand-held traffic radars, e.g., testicular cancer, a study was undertaken to quantify: (1) the distribution of the electric field (E) in the immediate vicinity of the antenna aperture of a typical 24-GHz hand-held traffic radar; and (2) the relative match and the corresponding depth of penetration of the absorbed energy when the antenna aperture is positioned in contact with material having properties similar to human tissue. The former measurements are important for assessing a large number of measurements reported by others using techniques that are not expected to be reliable indicators of power density at distances small compared with the size of the radiator; the latter are important for verifying predictions that energy from the antenna at 24-GHz will be predominantly absorbed in superficial tissue, i.e., the skin. The results of the first part of the study indicate that the equivalent-plane-wave power density in the plane of the aperture of the radar antenna is approximately one-half of the corresponding values reported in the literature; the results of the second part of the study indicate that the depth of penetration into material simulating human skin is approximately 0.5 mm 相似文献
793.
794.
MU Ferreira Q Liu M Kimura BT Ndawi K Tanabe F Kawamoto 《Canadian Metallurgical Quarterly》1998,84(6):1286-1289
Allelic diversity in the merozoite surface protein-1 (MSP-1) of Plasmodium falciparum, a major malaria vaccine candidate, was examined in clinical isolates from holoendemic northern Tanzania. The variable blocks 2, 4a, 4b, 6, and 10 of the MSP-1 gene were typed by allelic type-specific polymerase chain reaction. Twenty-four possible MSP-1 gene types were defined as unique combinations of allelic types detected in each variable block. Thirteen gene types were identified, and 187 P. falciparum populations were fully typed among 79 isolates. In contrast with recent findings in Vietnam, we were unable to detect nonrandom associations between allelic types in the typed variable blocks. Most patients (60%) harbored more than 1 genetically distinct parasite population (average: 2.37 populations per isolate) and, in 1 patient, 6 different versions of this single-copy gene were found. Statistical analysis suggests that parasites carrying different MSP-1 gene types are not independently distributed in the host population. The epidemiological consequences of these findings are discussed. 相似文献
795.
Islet allografts transplanted into Type I diabetic recipients may be destroyed by allorejection or recurrent autoimmune diabetes. We studied islet transplantation in three murine models in order to determine the relative sensitivity of autoimmunity and alloimmunity to two immunosuppressive agents that may be useful in clinical islet transplantation: 15-deoxyspergualin (DSG) and anti-CD4 antibody (GK 1.5). In the model in which only allorejection occurs (BALB/c islets transplanted into streptozotocin-induced diabetic CBA or streptozotocin-induced diabetic NOD recipients), both DSG and anti-CD4 antibody treatment led to indefinite survival of allogeneic islets (>100 days in both treatments). In the second model in which only recurrent autoimmunity can destroy islet grafts (islets from NOD donors transplanted into spontaneously diabetic NOD recipients), only anti-CD4 treatment caused prolonged graft survival [MST 36.7 +/- 6.8 days vs 9.8 +/- 1.8 days (controls), P < 0.0002]. Treatment with DSG did not cause any increase in graft survival (MST 12.6 +/- 5.4 days, NS). Finally, using a model in which both autoimmunity and allorejection may occur (BALB/c to spontaneously diabetic NOD mice), treatment with anti-CD4 caused marked graft prolongation [42.0 +/- 14.5 days vs 7.2 +/- 0.8 days (control), P < 0.002] while DSG again did not prolong graft survival with respect to untreated recipients (9.8 +/- 3.0, NS). We conclude that recurrent autoimmunity in the NOD mouse involves a CD4+ T cell that is not sensitive to DSG. Anti-CD4 antibody may be useful in human clinical islet transplantation trials because it seems to prevent both allorejection and recurrent autoimmunity. 相似文献
796.
For 13 years between 1980 and 1992, 23 patients needed pacemaker (PM) implantation because of bradyarrhythmia, 21 of atrial fibrillation and two of complete A-V block, after valve surgery. Five of 88 survivors (5.7%) after OMC, 11 of 227 (4.8%) after MVR, one of 169 (0.6%) after AVR, five of 67 (7.4%) after MVR + AVR and one of 15 (6.7%) after TVR underwent PM implantation in postoperative period. Two cases who had heart failure was implanted PM in early postoperative period. In late period, the mean duration between previous valve surgery and PM implantation was 6.4 years in 12 cases after initial valve surgery and 2.3 years in nine after second valve surgery. Postoperative course after PM implantation was almost good, but one case was died due to critical arrhythmia. And one case underwent re-MVR because of mitral bioprosthesis dysfunction and one, without anticoagulant after OMC, was complicated cerebral infarction. 相似文献
797.
The authors propose a new approach for subcube and noncubic processor allocations for hypercube multiprocessors. The main idea is to represent available processors in the system by means of a prime cube graph (PC-graph). The PC-graph maintains the inter-relationships between free subcubes and hence reduces both internal and external processor fragmentations. Their simulation results show that the PC-graph approach outperforms the existing allocation strategies by 25% to 50% under certain load conditions 相似文献
798.
R. W. Bartlett M. C. van Hecke C. Q. Hoard 《Metallurgical and Materials Transactions B》1972,3(8):2241-2245
A general equation for cathode impurity concentration is developed for steady-state electrorefining with an impurity that
is more readily reduced than the primary metal. The results depend on the equilibrium cathode/electrolyte distribution coefficient
and the transport properties of the electrolyte. Applicability is restricted to situations where electrode kinetics are not
rate limiting, such as most fused salt systems. Experimental results for copper impurity in a Sn/fused SnCl2/Sn system are compared with calculated cathode impurities as a function of cell voltage. 相似文献
799.
Research in the 1960s demonstrated the capabilities of infants and the demand characteristics of their behavior. These data, together with the failure of studies directed exclusively to parent effects on children, have led to a reformulation of socialization theory to encompass the reciprocal influences of parent and offspring. The cognitive capabilities, knowledge, and attitudes of parents assume a more important role in this theory. New research approaches are now available that can isolate parent and child effects, thus providing the foundation needed for identifying reciprocal influences. If research fills in the outline of this new perspective, and the viewpoint is communicated to parents, it should facilitate parent–child interaction. Previous theories, all too often given extreme expression in the mass media, have adversely affected the functioning of parents, either causing them to feel too much responsibility for their children's development, or leading them to mistake permissiveness for parental involvement and commitment. The reformulation should attenuate these extreme formulations, because neither of the latter is consistent with the concept of reciprocal influences. (9 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
800.
Thin foils of an aluminium alloy containing the fracture surface were studied in the electron microscope. The fatigue striations were visible due to thickness contrast and bands of dislocations. Supplementary etch pit studies and stereographic measurements were carried out. In many cases the crack plane was close to (100) or (110). The mechanism of fatigue crack propagation is discussed in the light of the new evidence. 相似文献