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991.
D Pende R Biassoni C Cantoni S Verdiani M Falco C di Donato L Accame C Bottino A Moretta L Moretta 《Canadian Metallurgical Quarterly》1996,184(2):505-518
Human natural killer (NK) cells express inhibitory receptors that are specific for different groups of HLA-C or HLA-B alleles. The majority of these receptors belong to the immunoglobulin (Ig) superfamily and are characterized by two or three extracellular Ig-like domains. Here we describe a novel inhibitory NK receptor that is specific for a group of HLA-A alleles. The HLA-A3-specific NK cell clone DP7 has been used for mice immunization. Two mAbs, termed Q66 and Q241, bound to the immunizing clone and stained only a subset of NK cell populations or clones. Among Q66 mAb-reactive clones, we further selected those that did not express any of the previously identified HLA-class I-specific NK receptors. These clones did not lyse HLA-A3+ (or -A11+) target cells, but lysis of these targets could be detected in the presence of Q66 or Q241 mAbs. On the other hand, target cells expressing other HLA-A alleles, including -A1, -A2, and -A24, were efficiently lysed. Moreover, none of the HLA-C or HLA-B alleles that were tested exerted a protective effect. Q66+, but not Q66- NK cell clones, expressed messenger RNA coding for a novel 3 Ig domain protein homologous to the HLA-C (p58) and HLA-B (p70) receptors. The corresponding cDNA (cl.1.1) was used to generate transient and stable transfectants in COS7 and NIH3T3 cell lines, respectively. Both types of transfectants were specifically stained by Q66 and Q241 mAbs. Since the cytoplasmic tail of Q66-reactive molecules was at least 11 amino acid longer than the other known p58/p70 molecules, we could generate an antiserum specific for the COOH-terminus of Q66-reactive molecules, termed PGP-3. PGP-3 immunoprecipitated, only from Q66+ NK cells, molecules displaying a molecular mass of 140 kD, under nonreducing conditions, which resolved, under reducing conditions, in a 70-kD band. Thus, differently from the other p58/p70 receptors, Q66-reactive molecules appear to be expressed as disulphide-linked dimers and were thus termed p140. The comparative analysis of the amino acid sequences of p58, p70, and p140 molecules revealed the existence of two cysteins proximal to the transmembrane region, only in the amino acid sequence of p140 molecules. 相似文献
992.
993.
The feasibility of applying a chemical method based on the formation of 2-alkylcyclobutanone to samples of irradiated soft cheese (Brie and Camembert) was investigated. Significant quantities of 2-dodecylcyclobutanone (DCB) and 2-tetradecylcyclobutanone (TCB) were detected in both types of irradiated cheese and are proposed as qualitative markers. Other members of the cyclobutanone family (decyl- and tetradecenyl-) are also thought to be present but could not be substantiated due to a lack of authentic standards. These compounds were absent from the unirradiated samples. Results also show a significant linear relationship between the irradiation dose (1 to 8 kGy) and the amount of DCB and TCB detected in the cheese. 相似文献
994.
Z Zdrojewski A Raszeja-Specht J Kustosz A Skibowska B Rutkowski 《Canadian Metallurgical Quarterly》1996,53(5):434-438
Platelets (PLT) play an important role in hemostasis, modulation of immunological and inflammatory processes. There is also evidence that PLT takes part in the development of atherosclerosis and glomerulosclerosis. The aim of presented study was to determine morphological and functional changes of platelets and their relation to the lipid, protein and coagulation factors disturbances in patients with chronic glomerulonephritis (CGN). The studies were carried out in 60 patients with CGN diagnosed by renal biopsy: 30 patients without nephrotic syndrome (NS)-CGN and 30 patients with NS-CGN+NS. Protein and lipid disturbances, coagulation factors were estimated using routine laboratory methods. Platelet count (PLT), mean platelet volume (MPV) and modal platelet volume (PLT-Mode) were measured using Technicon H1 hematological autoanalyser. Platelet function was assessed by aggregometry using turbidimetric method (inductors: ADP 1-3 microM, collagen 50g/ml, epinephrine 0.25-5 microM). Spontaneous platelet aggregation (SPA) was measured in platelet rich plasma (PRP) without inductors for 15 min, in 1-2 hours after venesection. SPA was observed in 9 of 30 patients with CGN and in 19 of 30 patients with CGN+NS. MPV and PLT Mode were significantly higher in patient showing SPA compared with those without. Significant correlations between SPA and the concentration of plasma albumin (r = -0,70; p < 0.02) TG and CH-LDL (r = 0,61; p < 0.05) were found in CGN+NS patients. APTT was significantly shorter in patients showing SPA compared with those without and negative significant correlation between SPA and APTT was found. Platelet aggregation to inductors in CGN and CGN+NS patients was diminished compared with control group. Lack of second phase aggregation in response to aggregation inducers was observed in patients with SPA. Conclusions. 1. Platelet hyperaggregation play an important role in hypercoagulation state in CGN patients. 2. SPA in vitro was observed in majority of CGN+NS patients and in some without NS. 3. Pathomechanism of SPA is probably multifactorial (hypoalbuminemia, dyslipidemia, changes in concentration of coagulation parameters). 相似文献
995.
996.
WKB近似下的Fourier衍射成象方法 总被引:1,自引:0,他引:1
对于介质目标微波衍射成象,本文引入了WKB近似来模拟目标内部总场。基于这种近似,我们导出了Fourier衍射公式,并采用了广义滤波逆传播方法由目标空间谱实现目标特性的重建。计算机模拟结果表明采用WKB近似重建目标特性较Born近似有明显改善。 相似文献
997.
S. Bismo P. Duverneuil L. Pibouleau S. Domenech J. -P. Couderc 《Materials and Manufacturing Processes》1995,10(2):241-266
This paper presents the results of our work on a new type of CVD reactor, annular reactor. This equipment is able to deposit pure silicon and also in-situ phosphorus doped silicon on a large number of substrates 相似文献
998.
Thermal water at Yufuin (Kyushu Island, Japan) is tapped through about 820 shallow wells and used mainly for hot-spring bathing purposes. Chemical and isotopic data for fluids from wells and fumaroles in Yufuin and Beppu indicate that the thermal activity at Yufuin represents a dilute, westward-flowing hydrothermal outflow plume from the Beppu hydrothermal system. Two other (eastward-flowing) outflow plumes have long been recognized at Beppu, but the Yufuin outflow plume is first recognized here. The Yufuin outflow plume is apparently a mixture of two end-member fluids: (1) deep high-temperature (250–300°C) fluid from the Beppu system having high chloride concentration (1400–1600 mg/L) and a δ18O value near −6.0%, and (2) meteoric water having low chloride concentration (≤7 mg/L) and a δ18O value near −9.2%.A permeable conduit for the vertical and lateral transport of deep fluid from the Beppu system is provided by the Yufuin Fault zone, which extends westward from the southern flank of Mt. Tsurumi volcano to the town of Yufuin. Stable isotope ratios and chloride concentrations for shallow groundwaters near the eastern end of the fault, at an elevation near 700 m, are consistent with those required for the low-chloride meteoric end-member of the Yufuin thermal waters. Recharge of this meteoric water, as well as mixing with the Beppu deep fluid, may occur along the Yufuin Fault. Enthalpy-chloride relations indicate additional conductive heating of the Yufuin waters, in the amount of 350–500 kJ/kg beyond that which can be accounted for by mixing between Beppu deep fluid and meteoric water. This could be a result of conductive heating with convection to a depth of 1–2 km. Estimates of the magnitude of the heat source for the Beppu hydrothermal system should take into account the heat being discharged at Yufuin. 相似文献
999.
Laser-induced chemical vapour deposition of silicon films on SiO2/Si (1 0 0) and Si (1 0 0) substrates was studied using ArF laser irradiation of silane/argon gas mixture in parallel to the substrate. The optimal deposition conditions were specified by examination of film morphology at a wide range of irradiation and process parameters. At optimal conditions, specular films were obtained with no powder formation. The effect of deposition parameters, such as laser energy and repetition rate, on the deposition rate and the related film quality, was investigated. 相似文献
1000.
The calculations of the first paper suggesting phase separation in the Hubbard model [2] are performed under modern computer facilties for the one and three-band Hubbard model. High-temperature approximations for specific heat and static correlation functions are obtained. The latter show, at these high temperatures, no tendency to phase separate in the same way as in the cited paper because our spin parallel nearest-neighbor charge correlation function is negative for all doping values. The spin antiparallel correlation function has positive and negative values for different doping regimes.Extension of this work to higher levels of iterations and to other correlation functions is in progress. 相似文献