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The literature is virtually devoid of studies examining the effect of aging on the ''global precedence'' effect (Navon, D. [1977]. Cognitive Psychology, 9, 353-383). In this paradigm, global letters formed with local letters are shown, and the subject has to recognize either the local or the global letters. The relation between the global and the local letters is either congruent, neutral, or conflicting. Five experiments are reported, with five sets of 16 young and five sets of 16 elderly, healthy, adult subjects. The global precedence effect was observed in both age groups in the basic perceptual experiment as designed by Navon (Experiment 1). In addition, young and elderly subjects were able to process separately the global and the local shapes when attention was not directed towards a specific level (Experiment 1a). However, subpopulations emerged, especially in the elderly, depending on their ability to ''resist'' to the interference of the global shape upon the processing of the local form. This could support the few indirect published data suggesting that global precedence tends to diminish or to disappear with age. In experiments 2 and 2a, subjects were retained only if they did process the local level better than at random. Global precedence was confirmed in both young and elderly subjects. Again, elderly subjects manifested an increased sensitivity to interference. Moreover, a general effect of age remained, even in the control (neutral) conditions, suggesting difficulties of encoding in elderly. Therefore, in Experiment 3, encoding conditions of both age groups were equated by increasing exposure durationof the material for elderly. Subjects of Experiment 3 were also submitted to a Strooptest, to verify whether the increased sensitivity to interference in the elderly was specific to the ''Navon task'' or the expression of a general effect of aging on inhibition mechanisms. The global precedence phenomen on was observed in young andelderly subjects, with no sign of an effect of age under these conditions; in elderly, furthermore, the interference effect did not appear to result froma general aspecific deficit of inhibition mechanisms. It thus appears that the global precedence phenomenon resists well the effects of aging, but that subpopulations of elderly subjects should be considered in future studies.  相似文献   
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BACKGROUND: No study on bioclinical criteria predicting a biliary origin for acute pancreatitis has included endosonography as a reference examination. Re-examination of bioclinical parameters deserves consideration in the era where other causes are known (e.g. hereditary, autoimmune). AIM AND METHODS: To determine the performance of bioclinical markers in predicting a biliary origin of acute pancreatitis where the diagnosis of biliary lithiasis was established or ruled out using endosonography. Only patients with a first acute episode of pancreatitis were included. RESULTS: 213 patients (male: 55%; median age: 56 years) were prospectively included in 14 centres. Causes of acute pancreatitis were: biliary (62%), alcoholic (25%), other (13%). Delay between symptom-onset and admission was <48 h in 80%. Endosonography was the sole method establishing the diagnosis of biliary pancreatitis in 15% of patients. At univariate analysis, age, female sex, declared alcohol consumption, elevated aspartate and alanine transaminases on admission, gammaglutamyl transferase, alkaline phosphatase, total bilirubin, lipase, mean corpuscular volume were predictive of a biliary origin. Only age (p < 0.0001), sex (p < 0.0008) and alanine transaminase (p < 0.0004) remained significant at multivariate analysis. At age 50, the respective sensitivity and specificity were 73 and 65%. With an elevated alanine transaminase at 2 times the upper limit of normal range, the respective sensitivity and specificity were 74 and 84%. The probability of a biliary origin of acute pancreatitis could be estimated by the following formula: = 1/1 + exp(4.6967 - 0.0656 x age + 1.1208 x sex - 0.6909 x alanine transaminase). CONCLUSION: When endosonography is performed to confirm or exclude a biliary origin of acute pancreatitis, age, sex and alanine transaminase at admission are the only factors predictive of a biliary cause.  相似文献   
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Pouchitis is the most significant long-term complication in patients with ileoanal pouch anastomosis (IAP) and is especially frequent in patients with ulcerative colitis. There is an urgent need for simple and objective parameters to assess the presence and activity of pouchitis. Whole-gut lavage fluid (WGLF) was collected from 34 patients [8 with pouchitis (PDAI > or = 7 points) and 26 without pouchitis (Pouchitis Disease Activity Index, PDAI, < 7)]. Patients with active ulcerative colitis (n = 8) served as controls. Concentrations of IgG and sCD44 in WGLF were measured by enzyme-linked immunosorbent assays and those of albumin by immunoturbidimetry. Similar to the case in active ulcerative colitis, concentrations of IgG, albumin, and sCD44 in WGLF were significantly increased in acute pouchitis and reached high specificity (IgG 96%, albumin 96%, sCD44 100%) and acceptable sensitivity (75%) for the diagnosis of acute pouchitis. These parameters were also closely correlated with disease activity as determined by PDAI and endoscopic scoring indices. Assay of protein concentrations in WGLF is thus a simple and objective means for grading inflammation of the pouch and may be useful as a quantitative index of disease activity in clinical studies.  相似文献   
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Statement of problemStereolithography (SLA) ceramic crown frameworks are suitable for clinical use, but the impact of SLA build orientation has not been identified.PurposeThe purpose of this in vitro study was to investigate the effect of 3 build orientations on the physical and mechanical properties and the microstructure of SLA alumina dental ceramics.Material and methodsThe physical and mechanical properties and microstructures of 3 different oriented SLA alumina ceramics (ZX, ZY, and XY) were evaluated by visual observation, hydrostatic weighing (n=10/group), Weibull analyses (n=30/group), scanning electron microscopy, 3-point flexural strength (n=30/group), fracture toughness (indentation, single-edge-V-notched-beam) (n=4/group), and Vickers hardness (n=15/group) testing. The hydrostatic weighing, 3-point flexural strength, fracture toughness, and Vickers hardness testing data were statistically analyzed (α=.05).ResultsThe minimum resting period of slurries between the polymerization of 2 layers was shorter for the ZY- and ZX-oriented specimens and increased with the layer surface. The density and Vickers hardness of the SLA-manufactured specimens were similar for all groups (P>.05). The 95% confidence intervals of the Weibull moduli of the ZX- and ZY-oriented specimens were higher than that of the XY-oriented specimens, with no overlap fraction. The ZY-oriented specimens displayed significantly higher 3-point flexural strength (P<.05) and fracture toughness as evaluated by the single-edge-V-notched-beam method than the ZX-oriented specimens (P<.05). They also displayed significantly higher 3-point flexural strength than the XY-oriented specimens (P<.05). The microstructural analysis showed that the texturing was heterogeneous and that the major axis of the large grains of alumina ran parallel to the orientation of the layers.ConclusionsThe ZY orientation produced a reliable dental ceramic by SLA, with the shortest general manufacturing time and the highest mechanical strength when the layers were perpendicular to the test load surface.  相似文献   
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PURPOSE: This study was designed to compare the results of two methods on the rate of postoperative perineum healing. PATIENTS AND METHODS: In this prospective, randomized, multicenter trial of 234 consecutive patients undergoing abdominoperineal rectal excision for carcinoma, 48 had unsatisfactory hemostasis or intraoperative gross septic contamination. Three patients were withdrawn because of protocol violation. Of the 45 remaining patients, 21 were randomized to undergo primary closure of the perineum with drainage while 24 underwent packing. Preoperative factors (sex, age, degree of obesity, weight loss, anemia, or presence of ascites), intraoperative findings (Dukes stage, degree of hemostasis, gross septic contamination), and postoperative oncologic courses (recurrence, mortality rate) were similar in both groups. All patients were followed for at least 12 months or until their demise. RESULTS: There was no significant difference in the number of early (one vs. zero) or late (five vs. four) deaths between primary closure and packing groups, respectively. Median duration of hospital stay was 25 and 27 days, respectively. Primary closure was associated with a significantly higher rate of healed perineums at one month (30 percent vs. 0 percent) (P = 0.01) and a shorter delay to complete cicatrization (median, 47 vs. 69 days) (P < 0.01). From three months onward, there was no difference in healing between the two groups, but two patients in the packing group had not healed at one year. Conversely, hematoma, perineal abscess, and reoperations were significantly more frequent (P < 0.01) in the primary closure group. CONCLUSION: Primary closure associated with drainage after abdominoperineal resection for carcinoma expedites perineal healing but morbidity is higher.  相似文献   
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Essential thrombocythemia (ET) and polycythemia vera (PV) are myeloproliferative neoplasms (MPN) with an increased risk of arterial and venous thrombosis. Aspirin is recommended to reduce this risk, but resistance to antiplatelet therapy seems to hamper its efficacy in some patients. We have previously shown that multiple electrode aggregometry (MEA) was a valuable tool to assess aspirin resistance in MPN. In this study, MEA was used to assess the reduction in aspirin resistance after bi-daily (BID) aspirin intake or cytoreduction.

Fifty one MPN patients (31 ET and 20 PV) receiving 75 mg aspirin once daily (OD) or BID, with or without cytoreductive treatment, were analyzed. Aspirin resistance was assessed using whole blood MEA (Multiplate®, Roche Diagnostics, Meylan, France).

In all patients, global aspirin resistance consisted mainly of turnover resistance (TOR). 94% of patients with OD aspirin intake and without cytoreduction displayed biological aspirin resistance. By switching to a BID aspirin regimen, the proportion of resistant patients reduced to 47%. Cytoreduction also contributed to reduce aspirin resistance in a similar way (50% of aspirin resistant patients). Combining cytoreduction and BID aspirin regimen was the most efficient way to reduce aspirin resistance yielding to 12% resistant patients. Moreover, a nonlinear correlation was observed between TOR and naive platelet counts regardless of aspirin regimen. Last, mutational status did not seem to affect TOR.

This study confirmed that BID aspirin is biologically more effective than OD aspirin in reduction of aspirin resistance. The latter was achieved through a reduction in TOR which was also decreased by cytoreductive therapy.  相似文献   

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