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991.
992.
993.
TEM studies of tungstenite crystals grown by sublimation method have been investigated. Dislocation loops observed during such studies have been reported. It has been shown by different methods that these loops have a vacancy character.  相似文献   
994.
Because skeletal images obtained with a commercial lyophilized preparation of 99mTc-Sn-pyrophosphate were occasionally degraded by liver and spleen uptake, a method for preparing 99mTc-Sn-pyrophosphate and a system for in-house quality assurance were developed. Control of the age of the stannous chloride solution and the final pH of the 99mTc-Sn-pyrophosphate eliminated the undesirable uptake. The quality and body distribution of the in-house preparation were compared to those of the radiopharmaceutical from a commercial kit.  相似文献   
995.
996.
CONTEXT: The prevalence of Bordetella pertussis and Bordetella parapertussis infections among outpatients in an immunized population is not known. OBJECTIVE: To study the prevalence of these infections in outpatients with paroxysmal cough in Finland, where the pertussis vaccine coverage of 4 doses is 98%. DESIGN: Prospective cohort study. SETTING: Thirty-two health centers in southwestern Finland. PATIENTS: A total of 584 patients with paroxysmal cough seen at local health centers from October 1994 through March 1997 from whom nasopharyngeal swabs were collected. MAIN OUTCOME MEASURES: Prevalence of positive cultures for B pertussis or B parapertussis and/or positive polymerase chain reaction (PCR) results and frequency of symptoms in those with pertussis and parapertussis. RESULTS: A total of 153 subjects (26.2%) had Bordetella infection by culture or PCR: 93 (60.8%) had B pertussis infection, 49 (32.0%) had B parapertussis infection, and 1 1 (7.2%) had both. Of these cases, 39 (25.5%) had positive cultures and 95 (62.1%) had positive PCR results for B pertussis, and 19 (12.4%) had positive cultures and 55 (35.9%) had positive PCR results for B parapertussis. At the time of diagnosis, no difference was found in the frequency of symptoms between patients with B parapertussis infection and those with B pertussis infection. Bordetella parapertussis infection was as common as B pertussis infection in children before school entry, whereas in schoolchildren and adults, B pertussis infection was more common than B parapertussis infection (P<.001). CONCLUSION: Bordetella infections are common in an immunized population, and B parapertussis infections apparently are more prevalent than previously documented.  相似文献   
997.
The authors investigated the cue dependency of source and item memory. Individuals listened to words spoken by a man or a woman and later determined whether a test word was previously presented by a man or by a woman, or whether it was a new word. Cue dependent effects were assessed by presenting test words with (a) the same voice (match condition) that originally presented the word, (b) a different but familiar voice (mismatch condition), (c) a novel test voice (novel condition), and (d) no test voice (control condition). Compared with the control condition, source recollection was facilitated in matching-context conditions, disrupted in mismatching-context conditions, and not affected in novel test conditions. By contrast, item recognition was not affected by the match–mismatch manipulation but was significantly worse in novel test voice conditions. The authors propose an associative source interference view to account for the voice match–mismatch effects observed in source recollection. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
998.
One hundred and four cases of Hodgkin's disease diagnosed between July 1981 and June 1991 have been analysed. There was a definite male preponderance. Majority of the patients (82.7%) were below the age of 50 years. Mixed cellularity was the most common type (57.7%). It was followed by both nodular sclerosis and lymphocyte predominant types (16.3% each). Lymphocyte depletion Hodgkin's disease, the most aggressive variant, was the least common (9.7%). The detailed observations, as compared to the previous studies in this region as well as in other parts of the world have been presented and discussed.  相似文献   
999.
PURPOSE: The management of patients with a normal digital rectal examination and a prostate specific antigen (PSA) level of 4.0 to 10.0 ng./ml. remains controversial. To improve the specificity of cancer detection in this group, PSA density has been recommended with biopsies based on a PSA density of 0.15 or more. To evaluate PSA density as a discriminator of prostate cancer we enrolled patients in a prospective study. MATERIALS AND METHODS: A prospective evaluation was done of 44 consecutive patients with a palpably normal digital rectal examination and a serum PSA level of 4.0 to 10.0 ng./ml. enrolled during a 13-month period. All patients underwent transrectal ultrasound with sextant biopsies regardless of calculated PSA density. RESULTS: Overall, 8 of 44 men (18%) had prostate cancer. There was no significant difference in the mean PSA density between the patients with positive and negative biopsies (mean 0.12 and 0.15, respectively, p = 0.258). Also, there was no significant association between PSA or PSA density and a positive biopsy in multivariate analysis (p = 0.863). Receiver operating characteristic curves for PSA and PSA density failed to demonstrate any superior benefit for PSA density in this patient population. A PSA density of 0.15 was an unreliable indicator of cancer (sensitivity 12.5%, specificity 61.1% and positive predictive value 6.7%). CONCLUSIONS: In our study, PSA density did not discriminate between patients with positive and negative biopsies, and in fact most cancers would not have been detected if a PSA density of 0.15 or more had been used as the sole indication for biopsy. Therefore, we recommend systematic biopsies in these patients independent of calculated PSA density.  相似文献   
1000.
The proboscis extension reflex (PER) can be elicited by applying a sucrose stimulation to the tarsus of a walking fly. This reflex decreases in frequency with repetition, presumably habituation, a nonassociative learning. If each sucrose stimulation is followed by a bitter stimulation, quinine chloride, the PER declines more rapidly, probably the result of conditioning, an associative learning. The present work shows that quinine chloride does not always inhibit PER suppressions but depends on the moment of delivery, being most effective when presented immediately after a sucrose stimulation. A bitter stimulus presented before, or simultaneously with a sucrose stimulation is less effective than habituation to sucrose alone. This experiment provides evidence for an interpretation in terms of cognitive association. The model of learning is not a Pavlovian conditioning as advanced by Medioni and Vaysse (1975), but corresponds to the punishment paradigm of Dyal and Corning (1973).  相似文献   
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