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1.
In the natural world, a number of visual cues indicate that an item is quickly approaching the perceiver. Binocular disparity is one cue for depth, and it has been demonstrated that abrupt changes in disparity, artificially unaccompanied by correlated depth cues, are capable of causing the perception of looming for the observer. An experiment involving 38 undergraduates, using a computer-controlled stereoscopic display, examined the ability of above-threshold changes in disparity (artificial looming) to facilitate response time and accuracy for observers engaged in an object-enumeration task within a cluttered display. Compared with performance using the same stimuli without disparity information (lateral motion), participants were more accurate regardless of the disparity level (9, 12, 24, or 48 minutes of arc) and faster at the two lowest levels of disparity. Participants showed the classic subitizing function, suggesting that target stimuli presented with motion information were segregated from otherwise identical distractor items. It is proposed that binocular disparity information can act as a valid location cuing method in stereoscopic computer displays in which form and color information are to be preserved. 相似文献
2.
S Luisi C Battaglia P Florio G D'Ambrogio F Taponeco M Santuz AR Genazzani F Petraglia 《Canadian Metallurgical Quarterly》1998,19(5-6):435-438
Activin A and inhibin B levels were measured, using a two-site enzyme immunoassay, in extra-embryonic coelomic fluid, amniotic fluid and maternal serum samples retrieved from 23 healthy pregnant women, at 8 (n=8), 9 (n=8), and 10 (n=7) weeks of gestation. Dimeric activin A and inhibin B were measurable in all samples. Median (+/-SEM) activin A concentrations in coelomic fluid (0.98+/-0.34 ng/ml) were significantly higher than in maternal serum (0.68+/-0.05 ng/ml) and in amniotic fluid (0.09+/-0.04 ng/ml) (P<0.05). Maternal serum activin A levels were significantly higher than amniotic fluid concentrations. Median (+/-SEM) inhibin B concentrations in coelomic fluid (24.32+/-6.02 pg/ml) were significantly higher than in maternal serum (5.94+/-0.97 pg/ml) and in amniotic fluid (6.31+/-1.53 pg/ml) (P<0.05), while no significant difference between maternal serum levels and amniotic fluid concentrations was found. No significant difference in activin A and inhibin B levels in extra-coelomic fluid, amniotic fluid, and maternal serum throughout the 3 weeks of pregnancy was found. The present study showed that coelomic fluid is an important reservoir of activin A and inhibin B, supporting the hypothesis that the extra-embryonic coelom may have a secretory role during the first 11 weeks of gestation. 相似文献
3.
HP Zahradnik F Geisth?vel R Weitzell M Breckwoldt 《Canadian Metallurgical Quarterly》1976,36(9):710-714
The concentrations of prostaglandin F-equivalents were measured in peripheral plasma during labour at a cervical dilatation of 5 cm and at complete dilatation. After purification, extraction and chromatography the PGF-equivalents were measured radioimmunologically. The intraassay variation was 1.5%, the interassay variation 3.5%. The specificity for PGF was 96-98%. Logit/log transformation of the standardcurve yielded a sensitivity of the assay of 120 pg. At cervical dilatation of 5 cm PGF-equivalents varied between 1300 and 3200 pg/ml plasma. At complete dilatation values changed between 1200 and 5400 pg/ml. These fluctuations correlate timedepending to the uterine contractions recorded and may be interpreted as a result of uterine PGF-release. 相似文献
4.
Amylin is a 37-amino acid peptide co-secreted from the pancreatic beta-cell with insulin in response to nutrient stimuli. Plasma amylin concentrations in the rat are reported to vary widely. We have employed a recently-developed immunoenzymometric assay to quantify plasma amylin concentrations in fasted, fed and glucose-administered rats. Fasted amylin concentrations ranged between 1.02+/-0.09 and 1.63+/-0.15pM among three different common rat strains, and increased up to 7.70+/-0.80 pM after feeding. The differences among strains and between fasted and fed rats were all significant at P<0.01 or less. Intravenous glucose administration (5.2 mmol/kg) also significantly increased plasma amylin concentrations in fasted rats from 1.5+/-0.3pM to 3.4+/-0.5pM, and in fed rats from 4.6+/-1.1 pM to 9.1+/-1.7 pM. Plasma amylin/insulin molar ratios ranged between 2.3+/-0.2% and 3.6+/-0.5% (mean 3.0%), but did not differ among strains, or between the fasted vs fed state in any strain. In conclusion, a new sensitive immunoenzymometric assay revealed fasting plasma concentrations which are lower than previously reported, and which are significantly increased by stimulation with feeding or glucose administration. 相似文献
5.
T Harigaya M Komori T Kawakami H Watanabe M Abe 《Canadian Metallurgical Quarterly》1997,44(1):155-161
Threshold photoelectron spectra of N2+ were measured between 23.4 and 27.6 eV with high resolution and high intensity by using the penetrating field technique and synchrotron radiation. Five vibrational progressions were observed. The first of these progressions was the C2Sigmau+ state. The second progression was identified as the transition to the second state of 2Pig symmetry found by P. Baltzer, M. Larsson, L. Karlsson, B. Wannberg, and M. Carlsson (1992. Phys. Rev. A 46, 5545). The third progression, which was discovered by F. Merkt and P. M. Guyon (1993. J. Chem. Phys. 99, 3400), can be designated as the 2Sigmau- state by comparison with previous theoretical study (E. W. Thulstrup and A. Andersen, 1975. J. Phys. B 8, 965). The fourth and fifth progressions were designated as the 2Deltau and 2(2) Piu states by similar comparison with previous theories. Copyright 1997 Academic Press. Copyright 1997Academic Press 相似文献
6.
Large-core (14g) needle biopsy (CNB) of the breast is a new diagnostic modality increasingly being used to evaluate patients with mammographic abnormalities. Two hundred twenty-four CNBs were performed on 198 patients. Surgical follow-up was available in 64 cases (28.6%). Overall concordance rate was 93.8% (60 of 64 cases). Of the four discordant cases, two were diagnosed as atypical ductal hyperplasia (ADH) on CNB; on excision, these cases showed cribriform ductal carcinoma in situ (DCIS); two remaining cases, diagnosed on CNB as ADH versus DCIS, showed invasive carcinoma (DCIS with invasive component and infiltrating cribriform carcinoma, respectively) on excisional biopsy. Malignancy, primary (52) or metastatic (5), was identified in 57 cases (25.4%); 47 of these patients underwent surgical excision, and the diagnosis was confirmed in all of these cases. Of 51 cases with radiographic evidence of microcalcifications, 48 (94%) had microcalcifications in the CNB: 30 (62.5%) were benign, 11 (22.9%) were malignant, and 7 (14.6%) were diagnosed as ADH. In the remaining three cases (1.3%), only benign breast tissue without microcalcifications was seen, and the lesion was considered to have been missed. Biopsy specimens were obtained from 173 lesions because of the presence of a mass: 125 (72.3%) were benign, 45 (26%) were malignant, and 3 (1.7%) were diagnosed as ADH. Follow-up was available in 118 patients with benign lesions: all were mammographically stable or decreased at 6 or 12 months; no follow-up was available for the remaining patients. CNB of the breast is a highly sensitive (96.9%) and specific (100%) technique for management of patients with mammographic abnormalities. The histologic findings should be correlated with the mammographic appearance, and an attempt should be made to achieve a specific diagnosis in all lesions, particularly masses. The diagnosis of ADH should always prompt excisional biopsy because of a high frequency of false-negative results caused by sampling errors or underestimation. 相似文献
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8.
In order to investigate the effect of fibrin glueing on the treatment or prevention of air leakages, 114 patients undergoing pulmonary resections and pneumonectomies were studied in two treatment groups: surgery alone (59 patients) or analogous surgical treatment followed by the application of fibrin glue (55 patients). The patients were randomly assigned to treatment groups within two strata: pulmonary resections (63 patients) and pneumonectomies (51 patients). Intraoperatively, 81% of the patients undergoing pulmonary resection who suffered from air leakages after conventional suturing showed improved results of the airway-tolerance-pressure test after the application of fibrin glue (one-sided P value < 0.01; 95% confidence interval: 58-95%). Treatment with fibrin glue reduced the incidence of postoperative leakages significantly from 66% in the control group to 39% in the treatment group (one-sided P-value < 0.02; estimated risk reduction 41%; 95% confidence interval 2-65%). An additional reduction of the duration of post-operative air leakages by the treatment with fibrin glue could not be shown. In terms of minor response criteria, slight trends for an advantage of treatment with fibrin glue could be observed for the duration of stay in hospital and the number of patients with complications. There were no obvious trends concerning fever, intraoperative and postoperative intubation times, the amount of secretion from thoracic tubes and the general condition of the patients. No adverse drug event related to fibrin glueing was observed. 相似文献
9.
Talin, an actin-binding protein from smooth muscle, is shown to bind to myosin in such a way that it stimulates the ATPase activity of myosin irrespective of the phosphorylation state of myosin. The binding site is shown to be localized at the N-terminal, 47 KDa fragment. The position of the actin-binding site at the C terminal suggests that talin may work as a crosslinker between myosin and actin. 相似文献
10.
An immunoassay for the quantitation of the angiotensin-converting enzyme inhibitor, captopril in human plasma is described. Antisera very specific for captopril were produced by immunization with captopril conjugated to bovine serum albumin or porcine thyroglobulin via the drug's thiol group. The antibodies were used to develop an enzyme-linked immunosorbent assay (ELISA) with a detection limit of 0.3 ng mL-1 and intra- and inter-assay coefficients of variation of 7 and 12%, respectively. Apart from stabilizing captopril by the addition of N-ethyl maleimide, the assay was used to detect the drug in human plasma without further extraction or purification. Our immunoassay provides a very sensitive and rapid (four hours) alternative for the study of captopril pharmacokinetics. 相似文献
11.
DD Ciupersescu 《Canadian Metallurgical Quarterly》1977,22(1):23-27
The relationship between endurance time and the mean force of contraction was investigated in intermittent and sustained static contractions over a long period of time (60 min). For intermittent static contractions the endurance limit of the mean force of contraction was found to be 14.0%, and for sustained static contractions it was 7.9% of the maximal force of contraction. Weak subjects appear to have a higher endurance limit of force than strong subjects. 相似文献
12.
Demonstration of vitamin B12 analogues in human sera not detected by microbiological assay 总被引:1,自引:0,他引:1
Sera were absorbed with polyacrylamide beads to which purified human intrinsic factor was attached. This procedure removed the vitamin B12 analogues which are measured by microbiological assay with Lactobacillus leichmannii and Euglena gracilis and which are measured in an isotope dilution method using intrinsic factor. Such sera still contained B12 analogues that were assayed in an isotope dilution method using a non-intrinsic factor vitamin B12 binder. Such vitamin B12 analogues make up approximately half of the total vitamin B12 analogues in human serum. 相似文献
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14.
With the advent of modern therapy, it has become essential to obtain a tissue diagnosis in all cases of pulmonary and mediastinal disease. Since it is often necessary to resort to thoracotomy as a final step in making such a diagnosis, we have sought a procedure that is simpler while capable of providing the same information. Through a standard cervical mediastinoscopy incision, the mediastinum is first explored; if the diagnosis is not obtained, the mediastinal pleura is digitally opened and lung or pleural biopsies are taken. In the course of 1,100 mediastinoscopies since 1969, 275 pleuroscopies have been done. We were able to obtain a tissue diagnosis in 102 (78%) of 131 patients with bronchogenic carcinoma, in 92 (91%) of 102 with benign pulmonary disease, and in all 20 (100%) with pleural disease. 相似文献
15.
The levels of lactogenic activity in the serum of rabbits during pregnancy and early lactation have been determined. The accuracy and sensitivity of the radioreceptor assay used were increased by several technical improvements. Lactogenic activity remained low throughout pregnancy and increased at parturition; the highest values were reached on day 5 of lactation. No lactogenic activity was detected in placental extracts of rabbits, suggesting that the lactogenic activity measured in the serum is solely of pituitary origin. These results are discussed in relation to the main stages of development of rabbit mammary glands. 相似文献
16.
VD Castracane DR Stewart T Gimpel JW Overstreet BL Lasley 《Canadian Metallurgical Quarterly》1998,13(2):460-464
As in other mammals, several nuclear basic proteins replace histones during the differentiation of germinal cells into spermatozoa in the ram. These proteins called transition proteins (TP) are later replaced by protamines. The amino acid sequence of the ram spermatidal protein 3 has been established by Edman degradation of the protein and of its fragments generated from digestion with endoproteinase Lys-C and pepsin and from the coding sequence of the gene and of the cDNA. The ram protein 3 is a basic protein of 109 residues (calculated Mr 13,200) with arginine and lysine residues uniformly distributed along the polypeptide chain. Of the 13 serine and threonine residues, 9 are located in structural motifs where they could be phosphorylated and, thus, modulate the binding of the protein to DNA. The tyrosine residues at position 33 and position 93, located in a basic environment, and the tryptophan residue at position 29 could be involved in the interactions of the protein with DNA through the stacking of their aromatic ring between the nucleotide bases. The ram protein 3 differs completely from the two well-defined transition protein families TP1 and TP2, which are also synthesised transiently during mammal spermiogenesis. In contrast with the rat TP3, ram protein 3 does not correspond to a precursor of a protamine. However, it shares structural similarities with both transition proteins TP3 and TP4 of the boar. The ram protein 3 and the boar transition proteins TP3 and TP4 probably belong to the same transition-protein group and would play similar functions in the chromatin remodelling during spermiogenesis. As protamine and transition-protein TP1 and TP2 genes from mammals, the coding sequence of the gene of ram protein 3 is interrupted by one intron but its organisation is different. 相似文献
17.
This long-term prospective study evaluates the clinical results of subsequent laminectomy in 103 consecutive patients who initially underwent chemonucleolysis (CNL) or laminectomy for lumbar disc herniation. Between 1981 and 1994, 53 patients who had received CNL initially and then underwent laminectomy and 50 patients treated initially with laminectomy underwent a repeat laminectomy. Clinical assessment at 6 weeks showed a success rate of 80.8% for post-CNL laminectomy and 78% for repeat laminectomy. At 6 months, the success rate for patients treated with CNL was 86% versus 78.7% for laminectomy. At 12 months, the overall success rate for the CNL group was 80.4% versus 83.3% for the laminectomy group, but in patients who had not obtained relief from the first procedure the success rate for the second procedure was higher for the post-CNL patients. A questionnaire was sent to all patients for 1- to 13-year follow-up review. The average follow-up period was 6.6 years for post-CNL laminectomy and 5.2 years for repeat laminectomy. The long-term success rate (81.8%) was higher in the post-CNL group compared to 64.4% in the repeat laminectomy group. Seven patients in the post-CNL group and nine in the repeat laminectomy group had undergone a third operation. When these originally successfully treated patients were reassigned after unsuccessful outcomes, the success rate for the CNL groups was 72.7%, versus 51.1% in the laminectomy group (p = 0.049). Employment rates were 80% for patients with CNL (21.8% changed jobs) and 76.3% for patients undergoing laminectomy (48.3% changed jobs) (p = 0.036). In conclusion, patients who underwent laminectomies after receiving CNL had significantly better long-term results than those who had repeat laminectomies. 相似文献
18.
A study of the presence of human viruses (adenoviruses, enteroviruses, and hepatitis A viruses [HAVs]) in environmental and shellfish samples was carried out by applying DNA and cDNA amplification techniques by PCR. The detection of human adenoviruses by PCR was also examined as a potential molecular test to monitor viral pollution. The samples studied were urban and slaughterhouse sewage, river water, seawater, and shellfish. Enteroviruses were quantified by PFU in Buffalo green monkey kidney cells and fecal coliforms and phages of Bacteroides fragilis HSP40 were also evaluated in some of the samples. The amplification of viral DNA and cDNA has shown a high prevalence of human viruses that would not be detected by the use of classical techniques, such as the quantification of PFU in cell lines. The results of the analysis of slaughterhouse sewage samples together with the test of farm animal feces indicate that the adenoviruses and the HAVs detected in the environment are mostly of human origin. A significative correlation between the detection of human viruses by PCR and the values of bacteriophages of B. fragilis HSP40 in urban raw sewage was observed. Human adenoviruses were the viruses most frequently detected throughout the year, and all the samples that were positive for enteroviruses or HAVs were also positive for human adenoviruses. The results suggest that the detection of adenoviruses by PCR could be used as an index of the presence of human viruses in the environment where a molecular index is acceptable. 相似文献
19.
Complexometric determinations of serum magnesium levels, moreover partly of Mg concentrations in whole blood, and withal determinations of hematocrit in 489 healthy pregnancies, parturients, puerperants (1 to 10 days post partum), and nonpregnant women were performed. By aid of these values we were able to calculate Mg concentrations in 100 ml erythrocytes (Mg E 100). The apparent decrease of serum Mg during pregnancy may be founded according to the changes of the plasma volume. However, actually the total (absolute) ammount of serum Mg is increased in pregnancy. We suppose some influences on serum Mg due to stimulation of the thyroid gland in pregnancy and further those of Mg being released from the muscular cells of uterus those been destroyed after delivery. The increased erythrocyte Mg during pregnancy and post partum confirm the view that there are no corresponding relations between Mg concentrations of serum and those of erythrocytes. The possible causes of the increase of erythrocyte Mg in pregnancy are discussed in detail. 相似文献
20.
The objective of this study was to find the earliest time at which it was possible to detect clinical pregnancy in an in-vitro fertilization (IVF) treatment cycle supported with human chorionic gonadotrophin (HCG), and also retrospectively to diagnose abnormal ovarian- or endometrium-related situations in failure cycles. Serum samples were taken in 41 IVF cycles at frequent intervals from the beginning of ovarian stimulation until menstrual bleeding occurred or a pregnancy was established. Concentrations of oestradiol, progesterone, placental protein 14 (PP14), pregnancy-specific beta 1-glycoprotein (SP1), and pregnancy-associated plasma protein A (PAPP-A) were determined in the serum samples using commercially available (steroid) or purpose-developed (protein) immunoassays. The cycles were retrospectively distributed into four outcome groups: (i) fertilization failure (FF, n = 8); (ii) implantation failure (IF, n = 10); (iii) 'interaction' (embryo-endometrium) cycle (IC, n = 14), and (iv) clinical pregnancy (CP, n = 9). The embryo-endometrium interaction was detected by a rise in SP1 in 23 cycles (70% of embryo transfers) at a time when endogenous HCG was still masked by external support. Early ('false') positive SP1 concentrations were observed in two out of eight and five out of 14 cases in groups FF and IC respectively, but never amongst the ongoing pregnancies (CP). PAPP-A did not distinguish pregnancy from the other outcomes. The PP14/progesterone ratio was lower, later in the cycle, in CP than in the other groups.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献