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We have studied a new timing circuit in which the input signal is put out at the same time as the clock signal. This is a key element for the realisation of Josephson vortex logic. We propose a new device structure which consists of two Josephson transmission lines connected by a resistor and a vortex trapping site (VTS). In this device a signal vortex is trapped in the VTS and it is repropagated to the output when the clock signal vortex propagates to the turning point. The quasistatic operation of this device is confirmed experimentally.  相似文献   
24.
The deposition of gold ions from atomic force microscope cantilever tips onto bulk insulating substrates with nearby surface electrodes is discussed. Numerical models of the potential distribution are used to estimate potential barriers for the desorption process. These models indicate deposition height thresholds of 7-10 nm with the tip 20-25 nm from the metallic electrode edge over a KBr surface but greater than 20 nm high for InP/GaAs/InP substrates with a two-dimensional electron gas (2DEG) as the back electrode. Experimental results for the deposition of gold clusters over KBr surfaces near metal electrodes in ultra-high vacuum (UHV) are presented and show promising agreement with calculations of the deposition threshold heights. Deposition of clusters over InP is discussed for comparison and indicates similar trends.  相似文献   
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BACKGROUND: In a previous study, it was shown that a spontaneously tolerated DA (RT1a) liver allograft in a PVG (RT1c) recipient was able to induce tolerance of a DA small bowel graft performed 17 days later in spite of infiltration of the intestinal grafts by mononuclear cells. AIMS: To compare the phenotype of graft infiltrating cells in rejecting and tolerated small bowel grafts in order to elucidate the mechanism(s) which block the graft infiltrating cells from mediating rejection. METHODS: Multiparameter immunofluorescence was used to compare the phenotype and state of activation of donor and recipient cells isolated from intestinal grafts rejected or tolerated after liver transplantation. RESULTS: Three differences were found. Firstly, there was a more rapid replacement of lamina propria (LP) cells by recipient lymphocytes in tolerated than in rejected grafts. Secondly, the proportion of LP recipient CD8alphabeta+ lymphocytes bearing the high affinity receptor for interleukin 2 was significantly less in tolerated grafts (1.1%, range 0-2%) than in rejected grafts (21.3%, range 9-26%). Finally, tolerated grafts contained significantly less NK lymphocytes (NKR-P1+) and macrophages than rejected intestinal allografts. CONCLUSIONS: These observations make it possible to delineate clear cut differences in the phenotype of cells infiltrating rejecting versus tolerated grafts. Furthermore, the data suggest that liver transplantation induces tolerance of intestinal grafts by hampering the activation of recipient TcRalphabeta+ CD8alphabeta+ T cells and subsequently the recruitment of non-specific effector cells.  相似文献   
26.
The dose of cells expressing the surface antigen CD34 (CD34+) has been shown to be a reliable predictor of the time to engraftment following transplantation of PBPC to support high-dose chemotherapy. However, evaluation of rare cells is complicated by a number of factors, including the variability in operator and technical procedures. Recently, Becton Dickinson Immunocytometry Systems introduced a new CD34+ cell analysis system, the ProCOUNT cell enumeration kit, which automates the analysis of CD34+ cells and minimizes the variabilities of this procedure. We have evaluated the ProCOUNT system in comparison to a standard CD34 cell analysis (based on the Milan approach) using leukapheresis products from patients and normal donors mobilized with chemotherapy plus recombinant human G-CSF (rhG-CSF) or with rhG-CSF alone. In addition, we compared these analyses using CD34+ cell-selected mobilized leukapheresis products with purities of 75% or greater. The standard CD34 cell analysis methodology quantitated the frequency of cells identified as CD45+, low side scatter, and CD34+. A high correlation coefficient was obtained between the ProCOUNT methodology and the standard CD34 cell analysis methodology for cells obtained from leukapheresis products mobilized with chemotherapy plus rhG-CSF (r = 0.98), rhG-CSF alone (r = 0.96), and CD34+-selected mobilized leukapheresis products (r = 0.83). A comparison was also made between technicians using both analysis methods. Whereas the correlation coefficient between two technicians using the standard methodology was r = 0.77, the correlation coefficient was much higher when using ProCOUNT (r = 0.99). These data demonstrate that the use of ProCOUNT is associated with less variability between data analyzed by different operators. Also, ProCOUNT is consistent with existing CD34+ cellular analysis methodologies. An additional advantage is the ability to determine the absolute concentration of CD34+ cells, thereby allowing calculation of total CD34+ cell numbers without using WBC counts, which also have inherent errors. The ProCOUNT system provides an automated analysis procedure that minimizes the variables in CD34+ cell analysis and may be useful for standardization of methodology between laboratories.  相似文献   
27.
A 12-year-old boy was admitted to our hospital because of abnormal shadows on a chest radiograph, slight fever, and superficial lymphadenopathy. Laboratory examination showed anemia (Hb 9.9 g/dl) and hyperimmunoglobulinemia (IgG 5469 mg/dl) without M protein. A chest CT scan showed bilateral diffuse shadows and bilateral hilar lymphadenopathy. Biopsy specimens of an inguinal lymph node and a lung showed many lymphoid follicles with germinal centers, and marked infiltration of mature plasma cells in the interfollicular area without destruction of follicular structures. The polyclonality of the plasma cells was confirmed by immunohistochemistry. The patient was not treated because these results excluded malignant disease and he was asymptomatic. At the age of 17 years, he was admitted to our hospital again because of dyspnea and a tendency to bleed. Interstitial pneumonia, hyperimmunoglobulinemia (IgG 13900 mg/dl), and anemia (Hb 6.6 g/dl) were found, along with thrombocytopenia (2.5 x 10(4)/mm3) and proteinuria. The serum interleukin-6 level was high: 177 pg/ml. Bronchoalveolar lavage fluid contained many plasma cells. Therapy with corticosteroids and immunosuppressant medication was effective. Our diagnosis was plasma cell interstitial pneumonia as a manifestation of multicentric Castleman's disease.  相似文献   
28.
The liquid velocity profile induced by a chain of bubbles is studied theoretically and a comparison with measurements is made. The wake velocity and the bubble shape involved in the theoretical development are considered based on the wake theory and the previous empirical relation for single bubbles, respectively. The shape and wake volume of chain bubbles can be treated in the same manner as those of single bubbles by using relative velocity. As a result, using the previous results of the drag coefficient and shape of single bubbles enables the prediction of the rising velocity of chain bubbles.  相似文献   
29.
A comprehensive classification system has been proposed by the AO/ASIF Foundation for the classification of long bone fractures. After an explanatory talk and with the aid of an illustrated pamphlet, 18 orthopaedic surgeons were asked to classify 10 long bone fractures according to the AO system. Three of the participating surgeons had previous experience of the classification system. After individual classification, a consensus classification was derived and the results of the individual and consensus codings were compared. Only 32 per cent of all codings agreed with the final consensus. There was no difference between the surgeons with previous experience of the system (66 per cent) and novice coders (69 per cent) in the number of inaccurate codes when compared with the consensus codes. Reasons for error in coding are discussed. It is recommended that if the AO system is used for the purposes of research and computer-based audit, a consensus of opinion is used as the basis of classification.  相似文献   
30.
Case 1 was a 53-year-old female who had a small nodule in the right S3 segment on chest CT. As she was not diagnosed by transbronchial lung biopsy (TBLB), open thoracotomy was performed. Case 2 was a 65-year-old female who had a nodule with pleural indentation in the right S6 segment. As this nodule showed difficulty to differentiate from small lung carcinoma, thoracoscopic surgery was performed. Case 3 was a 63-year-old female who had multiple lesions with cavity in the left S4 and S5 segments, which was preoperatively diagnosed by TBLB. She was performed thoracoscopic partial resection of the lingular segment because of poor response to antimycotic agents. All cases received preventive antimycotic agents for one or two months after the operation. There was no recurrence or postoperative meningitis. Thoracoscopic surgery is the effective procedure for the diagnosis and treatment of the localized pulmonary cryptococcosis.  相似文献   
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