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1.
Activation of the alternative complement pathway by respiratory secretory IgA was demonstrated by incubating purified, aggregated preparations of serum and secretory IgA with neat human serum. No depletion of the early components (C1-4) was observed, but 63 and 70% of C3-9, respectively, were consumed. The C3-9-consuming capacity of heat-aggregated nasal secretions from an IgA-deficient volunteer was compared with heat-aggregated nasal secretions from a normal volunteer known to have secretory IgA. The deficient secretions consumed C3-9, whereas the IgA deficient secretions did not. Reconstitution of the nasal secretions from the IgA-deficient volunteer with purified secretory IgA produced alternative pathway activation. Factor B of the alternative complement pathway was found to be present in 16 of 18 bronchoalveolar lavage samples (BALF) from normal volunteers. Simultaneous measurement of lavage and serum albumin and Factor B concentrations rendered it unlikely that Factor B was merely a transudative product from serum in half the samples but rather suggested that it may be a component of lower respiratory tract secretions. The presence of an intact alternative complement pathway in BALF was indicated by showing that cobra venom factor and endotoxin cleaved functionally pure human C3 when mixed with BALF, but had no effect on C3 in the absence of BALF.  相似文献   
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Current mechanical testing methods used to determine the biaxial properties of planar connective tissues may lead to artifactual observations of material behavior. The method of sample gripping affects the constraint on the extracellular fibers at the bounds of the sample. This applied constraint not only affects how the load is transferred to the sample, but also how the load is transmitted throughout the rest of the material – thereby influencing the resulting mechanical behavior of the tissue. In this study, we compared the dynamic biaxial mechanical response of pericardial tissue samples under two different gripping methods: (i) the common method of suturing sample edges and (ii) a new biaxial clamping method. Tissue samples were repeatedly testing using both gripping methods under the same conditions. The tissue samples appeared to be stiffer and less extensible when mechanically tested with clamped sample edges, as opposed to when tested with sutured sample edges. Thus, the influence of the sample boundaries affected the response of the material – precisely the situation to be avoided for reliable material testing. This casts doubt on whether any in vitro mechanical testing method can used to determine the real properties of the tissue since the boundary conditions of the tissue in situ are presently unknown.  相似文献   
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A model describing the angular selectivity of noise gratings in volume holographic recording materials is presented. The noise grating is treated as an ensemble of superimposed, statistically distributed planar gratings. Rigorous coupled-wave analysis is used to treat reconstruction with various polarization states. The model accounts for material properties such as thickness change, absorption, and the angular distribution of scattered light within the recording medium. Results show good agreement with noise gratings that are experimentally formed in a thick cationic ring-opening photopolymer material.  相似文献   
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The effects of the CCK(B) antagonists, CAM1028 and CI988 and a CCK(A) antagonist, CAM1481, were studied on the anxiety-related behaviour produced by withdrawal from chronic ethanol treatment, using the elevated plus maze. Cessation of chronic ethanol administration produced a profile, in both mice and rats, consistent with increase in anxiety-related behaviour. In mice, SC administration of CAM1028 or CI988 reduced the decrease in the time spent on the open arms, the number of entries into these arms and the increases in the latencies to first open arm entry, after withdrawal from the ethanol treatment. The increases in stretched attend postures and head dips from the closed arms and the central square seen during the withdrawal phase, were also decreased by the CCK(B) antagonists, but the decreases in the number of rears and in general activity were unaffected. The doses of CAM1028 and CI988 tested were 0.1 and 1 mg/kg; for some of the withdrawal-induced changes in behaviour only the 1 mg/kg dose was effective. In contrast, the CCK(A) antagonist, CAM1481, at the same doses, had little effect on the anxiety-related behaviour produced by withdrawal from chronic ethanol treatment, although it did decrease the changes in the number of rears and the head dipping behaviour. In rats, the majority of the changes produced by withdrawal from chronic ethanol treatment were decreased by CAM1028 at 1 mg/kg, although the decreases in open arm entries, rearing behaviour and in overall activity were unaffected. CAM1028, CI988 and CAM1481 had no effects on the behaviour of control mice or rats in the plus-maze. The results show that CCK(B) antagonists were effective in decreasing the majority of the anxiogenic effects of withdrawal from chronic ethanol treatment.  相似文献   
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Upper bounds on the rate of codes in DC-constrained spaces are derived for imbalances 3, 4, and 5. The new bounds are based on the identification and size calculation of the minimal Hamming spheres. A new combination of the Hamming and Plotkin (1960) bounds for constrained spaces is obtained  相似文献   
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Investigated relationships between the performance levels of incumbents on job skills and the importance attributed to those job skills. Supervisors and job incumbents rated both the performance of skill dimensions and the importance of those skills for respective incumbents' positions. Results indicate that the ratings of performance and importance on matched skill areas correlated positively, although relationships were somewhat stronger for incumbent data as compared with data provided by supervisors. Supervisors and incumbents agreed moderately on which skill areas were important for various positions, but the interrater agreement was much lower for performance ratings of the skill areas. For some skill areas, incumbent-rated importance and supervisor-rated performance, as well as incumbent-rated performance and supervisor-rated importance, were significantly correlated. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
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BACKGROUND: Tumor labeling index has emerged as a strong predictor of the clinical course of women with breast cancer. This study investigated whether labeling index of primary tumors correlates with labeling indices of concurrent regional node metastases. METHODS: With appropriate written consent, preoperative in vivo infusion of the thymidine analogue 5-bromodeoxyuridine (BrdUrd) was used to label 109 human breast cancers. Labeled S-phase cells were identified immunohistochemically with an antibody specific to DNA-incorporated BrdUrd. Labeling index was the fraction of labeled nuclei in 2000 tumor nuclei. For 30 women, there was sufficient cancer in axillary lymph nodes to compare labeling indices in primary breast cancer and regional lymph node metastases. RESULTS: The 30 women were from 25 to 82 years of age. Tumors were from 1 to 12 cm in size and there were from 1 to 26 positive nodes. Tumor labeling index ranged from 0.1% to 34%, (mean, 11.1%; median, 10.3%) and axillary lymph node metastasis labeling index ranged from 0.1% to 27.7% (mean, 10.8%; median, 10.0%). There was strong correlation between primary tumor labeling index and regional lymph node metastases labeling index (r = 0.82, with 95% confidence interval 0.65-0.91). The correlation persisted within subgroups according to age, tumor size, number of positive nodes, and hormone receptor status. Primary tumor and lymph node metastases labeling indices also had statistically similar relationships with age, level of hormone receptors, tumor size, and number of positive nodes. CONCLUSIONS: Primary tumor and regional node labeling indices correlate strongly; the relationship is not influenced by age, level of hormone receptors, tumor size, or number of positive nodes.  相似文献   
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