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1.
Target set size refers to the number of preexisting connections a studied word has to closely related concepts in long-term memory. The purpose of this investigation was to determine whether target set size influences feeling-of-knowing (FOK) ratings. The results showed that ratings were higher for targets connected to smaller sets, as compared with those connected to larger sets. Comparable effects were obtained with the use of different encoding strategies, including concreteness classifications and vowel naming, and with both meaningfully and phonologically related test cues. These findings indicate that FOKs are sensitive to competition between concepts linked to the target and that this sensitivity is independent of encoding strategy and type of test cue. Response time measures indicated that FOKs are sensitive to competition that arises when concepts are activated in parallel, whereas recall is more sensitive to competition that arises during sampling associated with search. Implications for various cue-based and target-based explanations of FOK effects are discussed.  相似文献   

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The examinations of 71 patients having comprehensive 2D time of flight (TOF) abdominal magnetic resonance venography (MRV) in three planes (axial, sagittal and 10 degrees offset coronal) were evaluated to assess the appearances of anomalous left renal veins as shown by MRV. Six cases of circumaortic left renal vein (CLRV) (8.5%) and one example of retro-aortic left renal vein only (1.4%) were identified, an incidence higher than that in previous computed tomography (CT) studies but comparable to venographic and post-mortem investigations. All retro-aortic components passed in a caudal direction to join the inferior vena cava (IVC) inferior to the anterior limb. MRV acquired in the sagittal plane was found to be most useful for identifying these variants and provided highest signal by avoidance of in-plane flow saturation effects.  相似文献   

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This study summarizes 24,000 transvaginal ultrasound examinations which were performed in a predominantly low-risk population at 14-16 weeks' gestation. 1254 (5.2 per cent) fetuses had a nuchal fold or a non-septated cystic hygroma. Of these fetuses, 140 (11.1 per cent) had additional structural anomalies. Cardiovascular anomalies were the most commonly detected structural malformations. Forty-three (3.4 per cent) fetuses were aneuploid. Trisomy 21 was the most common chromosomal anomaly (n = 27). Aneuploidy was significantly more common in fetuses who had a nuchal finding and an associated structural anomaly. The prevalence of nuchal fold and non-septated cystic hygroma, as well as the incidence of their associated structural anomalies, was similar. Based on these data, it is concluded that a complete ultrasonic survey of the fetus and karyotyping are advocated in fetuses with a nuchal abnormality, irrespective of maternal age or triple serum screening results.  相似文献   

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Phathalate esters, which are commonly used as plasticizers for polyvinyl chloride, are also well known to disturb Sertoli cells. This study aims to show the effect of prenatally administered phthalate on testicular descent in pre- and postnatal rats. Pregnant rats were exposed to mono-n-butyl phthalate (MBP) by gavage from the 15th to the 18th gestational days. Rats administered with solvent only were used as controls. In 20-day-old fetuses (n = 15), the degree of transabdominal testicular ascent in relation to the bladder neck was thus found to be significantly higher in MBP-treated rats than that of the controls (n = 19). In addition, in MBP-treated male offspring (n = 26), 22 rats showed either bilateral or unilateral cryptorchidism at the age of 30 to 40 days old, and the occurrence of cryptorchidism was 84.6%. By contrast, the occurrence of cryptorchidism was 0% in the control rats (n = 15, P < .001). It is therefore suggested that prenatal exposure to MBP may disturb the Sertoli cells and elevate the fetal testes relative to the bladder neck while also inducing cryptorchidism postnatally. Sertoli cells may thus play an important role in the transabdominal descent of the testis by secreting Müllerian-inhibiting substance (MIS), which is known to act as a putative mediator of the transabdominal phase.  相似文献   

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Normal values of the pulsatility index in the fetal renal arteries in a group of 65 uncomplicated pregnancies were established. The measurements were obtained between 28 and 40 weeks of gestation. The values of pulsatility index may be used as a reference for further investigation of pathologic pregnancies.  相似文献   

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OBJECTIVE: The etiology and pathogenesis of renal dysplasia are poorly understood. To characterize the histologic changes in fetal renal dysplasia, we studied a fetal ovine model of urinary obstruction. DESIGN: Animal study. ANIMALS: Seven fetal lambs, and other lambs of the same gestational age as controls. INTERVENTIONS: Unilateral ureteral ligation on fetal lambs at approximately 70 days' gestation (term for sheep is 145 days), during nephrogenesis. Kidneys were subsequently collected, examined histologically and characterized by immunohistochemical tests involving cytokeratin antiserum and a monoclonal antibody to alpha-actin. OUTCOME MEASURES: Histologic changes in ligated fetal lamb kidneys, based on comparison with normal fetal lamb kidneys. RESULTS: At near term (140 days' gestation), the ligated kidney showed distorted and less abundant renal parenchyma than a normal control kidney. Upon microscopic examination, the ligated kidney displayed marked architectural distortion of the outer cortex, with abundant interstitial fibrosis, primitive ductules and glomeruli, and cysts of varying sizes lined by squamous and cuboidal epithelia and surrounded by a loose mesenchyme. The renal medulla contained differentiated collecting ducts, which were structurally distorted and less abundant than in normal control kidneys. The proximal and distal tubule elements were primitive and markedly underdeveloped. Cytokeratin immunoreactivity was present in the collecting duct epithelium and in the cuboidal epithelium lining many of the cortical cysts. Smooth muscle alpha-actin immunoreactivity was localized in the cortical region of the kidney, which highlighted the abundance and disorganization of the undifferentiated mesenchyme and identified the fibromuscular collars of the primitive ductules of the cortex and the distorted collecting ducts of the medulla. CONCLUSIONS: These results highlight the histologic changes resulting from unilateral ureteral ligation in fetal lambs. This model is useful in the study of the pathogenesis of fetal obstructive renal dysplasia.  相似文献   

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A 29-y-old male attempted suicide with 3000 mg clozapine, 150 mg zopiclone, alprazolam and unknown quantities of alcohol. He was admitted in a deep hypotonic coma with respiratory depression, inhalation pneumonia and vascular collapse. Symptomatic treatment involved mechanical ventilation, vascular filling and antibiotics. The patient was discharged from the Intensive Care Unit 72 h after the suicide attempt with no sequelae. To detect and quantify clozapine in plasma, high-pressure liquid chromatography showed a 4 h absorption phase and a peak serum concentration of 5200 ng/ml. Three successive elimination t1/2 values of 38, 24 and 13 h were calculated.  相似文献   

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The objective of this study was to evaluate the effectiveness of the measurement of maternal serum alpha-fetoprotein (MSAFP) at 16 weeks and a subsequent routine ultrasound screening at 18-20 weeks' gestation and the impact on the birth prevalence of congenital structural anomalies in an unselected pregnant population of Hungary in a prospective epidemiological study. A total of 63,794 pregnant women (representing one-sixth of the population of Hungary) were offered this screening program over 3 years (1988-90). Of the pregnant population, 75.7% (48,312) received MSAFP screening and in 81.0% (51,675), at least one ultrasound scan was performed. In the screened pregnancies, 496 craniospinal, thoraco-abdominal, urogenital and other severe major anomalies occurred; 317 were detected at 18-20 weeks (sensitivity 63.1%; specificity 100.0%; positive predictive value 100.0%). The sensitivity of ultrasound scanning was significantly higher (p < 0.05) than that of the MSAFP screening. (At the time of ultrasound scanning the MSAFP value was known.) In this study, the less serious anomalies such as hydrocele, hypospadias and undescended testicle were not systematically searched for, but the birth prevalences were calculated. The overall mid-trimester prevalence of severe plus less severe major anomalies was 2.26%. The birth prevalences of severe major anomalies were 0.57 (craniospinal), 4.36 (thoracoabdominal and urogenital) and 1.21 (other severe) per 1000. These values were lower than the mid-trimester prevalences which were 2.94, 5.20 and 2.06 per 1000, respectively. The prevalence values at the age of 1 year were also calculated (0.36, 2.21, 0.54 per 1000, respectively). We conclude that our screening program with availability of termination of pregnancy could significantly (p < 0.05) reduce the prevalence of severe major abnormalities at birth. Training programs in cardiac scanning are required.  相似文献   

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The advantages and limitations of transvaginal (TV) sonography in detecting fetal anomalies in the 12th week of pregnancy were examined in a prospective screening study of an unselected population. During a 3-year period, 3991 examinations were performed and 35 fetuses were identified as having 43 anomalies (0.9 per cent). Most of these malformations were either severe structural disorders or isolated nuchal changes when karyotyping revealed chromosomal aberration in six cases. Twenty-one pregnancies were terminated and three fetuses died. Routine transabdominal (TA) ultrasonographic examinations were performed at 18 and 30 weeks in all those pregnancies where the TV scan had not found fetal anomalies. TA sonography identified 19 abnormal fetuses and ten cases remained undetected. TV sonography detected 51 per cent of malformed fetuses which were diagnosed prenatally (not including cases with nuchal oedema) and 41 per cent of the total were found in this study. Besides offering the possibility of early termination, first trimester screening has the advantage of identifying a transient sonographic sign, nuchal oedema, which can be used as a marker in screening for fetal chromosomal abnormalities. However, standard mid-second-trimester TA scanning is still recommended, since a significant number of malformations cannot be detected so early in pregnancy.  相似文献   

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We studied the effect of pyridostigmine bromide, a nerve agent prophylactic, on the central nervous system (CNS) uptake of [14C]permethrin, a pyrethroid insecticide, at scaled human-equivalent exposures in rats using accelerator mass spectrometry (AMS). AMS detects 14C at attomole sensitivities and determines the tissue distribution of 14C-labeled compounds. Pyridostigmine bromide in chow at 7.75 mg kg(-1) per day lowered the CNS tissue levels of permethrin, dosed at 4.75 microg kg(-1), in the CNS of rats by 30%. These results are inconsistent with hypothesized synergy of such compounds as a precursor to 'Gulf War syndrome'.  相似文献   

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The diagnosis of a kidney trauma is discussed and the great importance of angiography besides i. v. urography and retrograde pyelogram is pointed out. In surgical treatment exact urinary diversion and wound drainage are most important points to avoid later complications.  相似文献   

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Four cytotoxic lignans were isolated from the stem bark of Bursera permollis (Burseraceae), namely, deoxypodophyllotoxin (1), beta-peltatin methyl ether (2), picro-beta-peltatin methyl ether (3), and dehydro-beta-peltatin methyl ether (4). Also isolated was the inactive lignan, nemerosin (5). Compounds 1 and 2 were potently cytotoxic when evaluated against a panel of human cancer cell lines.  相似文献   

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