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32P in membrane phosphatidylethanolamine (PE) and red cell 14C, reflecting cytoplasmic hemoglobin, were measuredsequentially in rats given transfusions ofdoubly-labeled reticulocytes. With reticulocytes from normal rats there was a smalldecline in the levels of both the membraneand the cytoplasmic labels; the changeswere almost parellel, although loss ofmembrane PE-32P exceeded that of 14C toa small extent. By contrast, with "stressreticulocytes" from bled donors, there wasa markedly disproportionate loss of themembrane label; this asymmetrical lossof membrane material was diminishedwhen recipients had been splenectomized.With transfusions of doubly-labeled reticulocytes from rats with severe iron deficiency anemia, there was a marked lossof both membrane PE-32P and red cell 14Cwhich was only moderately asymmetrical.The asymmetrical loss of the membranelabel found with stress reticulocytes supports the conclusion that these cells undergo a process of surface remodeling duringtheir maturation in the peripheral blood.The spleen is partly responsible for thisprocess. Normal reticulocytes also appearto undergo a minor degree of remodeling.On the other hand, the almost symmetricalloss of membrane and cytoplasmic labelobserved with reticulocytes from iron deficient rats indicates that many of thecells in this model of ineffective erythropoiesis are hemolyzed in their entirety.These experiments demonstrate that stressreticulocytes differ under different conditions and may lose cellular material bytwo, possibly interrelated, mechanisms:surface remodeling or whole-cell hemolysis.

Submitted on January 9, 1974 Accepted on June 19, 1974  相似文献   
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Reliable real-time quantitative PCR assays to measure Epstein-Barr virus (EBV) DNA load (EBV) are useful for monitoring EBV-associated diseases. We evaluated a new commercial kit, EBV R-gene Quantification kit (Argene, Varilhes, France) to quantify EBV DNA load in whole blood. Assay performance was assessed with two PCR platforms (LightCycler 2.0 and SmartCycler 2.0) and three commercial DNA extraction methods. The assay was compared with our in-house real-time EBV PCR using samples from the Quality Control for Molecular Diagnostics 2006 EBV proficiency program and using 167 whole-blood specimens from individuals with infectious mononucleosis, from transplanted or HIV-infected patients, and from EBV-seropositive healthy carriers. The EBV R-gene assay was sensitive to 500 copies of EBV DNA per milliliter of whole blood with the two PCR platforms and the three extraction methods and was linear across 4 orders of magnitude. Intra- and interassay coefficients of variations were less than 20%. Nine of 10 samples tested with the EBV R-gene were in agreement with the expected qualitative results of the Quality Control for Molecular Diagnostics 2006 EBV proficiency program, and 7 of 10 samples were within +/-0.5 log units of the expected quantitative values, with discrepant results mostly observed for low viral load (ie, <1000 copies/ml). In the clinical specimens, the correlation between the R-gene assay and the in-house PCR was high (r=0.92). In conclusion, the EBV R-gene assay accurately assesses the EBV DNA load in whole blood of patients with various forms of EBV infections.  相似文献   
5.
Objective  To assess the ability of echocardiographic data to predict important functional status outcomes in patients with chest pain. Design  Prospective cohort study. Setting  A large, urban teaching hospital. Patients  Three hundred thirty-three patients admitted from the Emergency Department for evaluation of chest pain. Measurements and Main Results  Patients underwent two-dimensional and Doppler echocardiography as well as a face-to-face interview during their initial hospitalization and a telephone interview 1 year thereafter. The interview included the Medical Outcomes Study 36-Item Short Form (SF-36) health inventory, a generic health status instrument with a physical function subscale. The relation between clinical and echocardiographic factors and functional status was explored by univariable and multivariable linear regression and logistic regression analyses. Multiple clinical and echocardiographic factors correlated significantly with functional status measures at 1 year. For the SF-36 score at 1 year, age, male gender, white race, the presence of rales, and a comorbidity score were independently predictors in multivariate analysis; echocardiographic findings of severe left ventricular dysfunction (parameter estimate [PE] −27.6; 95% confidence interval [CI] −43.1, −12.2) and aortic insufficiency (PE −16.7; 95% CI −26.4, −7.0) added independent predictive information. Explanatory power (r 2) for models using clinical and demographic variables was .27 and increased after inclusion of echocardiographic data to an r 2 of .35. Results in the subset of patients (n=148) with acute coronary syndromes such as unstable angina or myocardial infarction were qualitatively similar. Selected factors (rales on examination, electrocardiographic changes suggestive of ischemia, and moderate to severe mitral regurgitation) also predicted which patients would die or have a decline in their functional status. In multivariate analysis, only rales remained an independent predictor of poor outcome (odds ratio 2.4; 95% CI 1.2, 4.5). Conclusions  Echocardiographic data are correlated with measures of functional status in patients with chest pain, but the ability to predict future functional status from clinical or echocardiographic information is limited. Because functional status cannot be predicted adequately from either patients’ characteristics or echocardiographic testing, it must be assessed directly. Dr. Fleischmann is the recipient of a Clinical Investigator Development Award (IK08HL02964-01) from the National Heart, Lung and Blood Institute.  相似文献   
6.
Preliminary reports have documented the utility of balloon aortic valvuloplasty as a palliative treatment for high-risk patients with critical aortic stenosis, but the effect of this procedure on cardiac performance has not been studied in detail. Accordingly, 32 patients (mean age 79 years) with long-standing, calcific aortic stenosis were treated at the time of cardiac catheterization with balloon dilatation of the aortic valve, and serial changes in left ventricular and valvular function were followed before and after valvuloplasty by radionuclide ventriculography, determination of systolic time intervals, and Doppler echocardiography. Prevalvuloplasty examination revealed heavily calcified aortic valves in all patients, a mean peak-to-peak aortic valve gradient of 77 +/- 27 mm Hg, a mean Fick cardiac output of 4.6 +/- 1.4 liters/min, and a mean calculated aortic valve area of 0.6 +/- 0.2 cm2. Subsequent balloon dilatation with 12 to 23 mm valvuloplasty balloons resulted in a fall in aortic valve gradient to 39 +/- 15 mm Hg, an increase in cardiac output to 5.2 +/- 1.8 liters/min, and an increase in calculated aortic valve area to 0.9 +/- 0.3 cm2. Individual hemodynamic responses varied considerably, with some patients showing major increases in valve area, while others demonstrated only small increases. In no case was balloon dilatation accompanied by evidence of embolic phenomena. Supravalvular aortography obtained in 13 patients demonstrated no or a mild (less than or equal to 1+) increase in aortic insufficiency. Serial radionuclide ventriculography in patients with a depressed left ventricular ejection fraction (i.e., that less than or equal to 55%) revealed a small increase in ejection fraction from 40 +/- 13% to 46 +/- 12% (p less than .03). In addition, for the study group as a whole there was a decrease in left ventricular end-diastolic volume index (113 +/- 38 to 101 +/- 37 ml/m2, p less than .003), a fall in stroke-volume ratio (1.49 +/- 0.44 to 1.35 +/- 0.33, p less than .04), and no immediate change in left ventricular peak filling rate (2.05 +/- 0.77 to 2.21 +/- 0.65 end-diastolic counts/sec, p = NS). Serial M mode echocardiography and phonocardiography showed an increase in aortic valve excursion (0.5 +/- 0.2 to 0.8 +/- 0.2 cm, p less than .001), a decrease in time to one-half carotid upstroke (80 +/- 30 to 60 +/- 10 msec, p less than .001), and a small decrease in left ventricular ejection time (0.44 +/- 0.03 to 0.42 +/- 0.02 sec, p less than .001).(ABSTRACT TRUNCATED AT 400 WORDS)  相似文献   
7.
The incidence of breast cancer diagnosed during pregnancy is increasing. We sought to characterize patient, treatment, pregnancy and lactation factors among young women with newly diagnosed breast cancer during pregnancy in a prospective cohort study. We identified all women who were pregnant when diagnosed with invasive breast cancer among those enrolled in the Young Women's Breast Cancer Study (NCT01468246), and collected details on pregnancy, birth and lactation from surveys, and treatment information medical record review. Of 1302 enrolled participants, 976 women with invasive breast cancer completed full baseline surveys, among whom 39 (4.0%) patients reported being pregnant at diagnosis. Median age at diagnosis was 34 years (range: 25‐40), with stage distribution: I, 28%; II, 44%; III, 23%; and IV, 5%. 74% of patients (29/39) had grade 3 tumors, 59% (23/39) ER‐positive, and 31% (12/39) HER2‐positive disease. 23 (59%) had surgery during pregnancy, 4 (17%) during the first trimester. Among the women who had surgery during pregnancy, 61% (14/23) underwent lumpectomy, 35% (8/23) unilateral, and 4% (1/23) bilateral mastectomy. All patients who had chemotherapy (51%, 20/39) received it in second and third trimesters, and had ACx4. There were 31 live births, 2 spontaneous, and 5 therapeutic abortions. Among live births, 16 (41%) were before 37 weeks of gestation. Three women reported breastfeeding. Within 6 months after delivery, comprehensive staging in 13 patients showed upstaging in four patients. In a contemporary cohort of young women with breast cancer, pregnancy at diagnosis is relatively uncommon. Treatment during pregnancy can generally be consistent with standard surgical and chemotherapy approaches, with attention to timing of therapies. Longer‐term outcomes including effects of some timing issues including delayed use of anti‐HER2 therapy on patient outcomes warrant further research.  相似文献   
8.
The optimal means of combining breast-conserving surgery, radiation therapy, and chemotherapy for the treatment of patients with early-stage, node-positive breast cancer is not known. We reviewed the results in 295 patients treated at the Joint Center for Radiation Therapy and affiliated institutions from 1976 to 1985. All patients had positive axillary nodes on dissection, had no gross residual disease in the breast or axilla after surgery, and received breast irradiation (with or without nodal irradiation) and three or more cycles of a cyclophosphamide, methotrexate, and fluorouracil (CMF)-based or doxorubicin-containing regimen. Median follow-up in patients without any failure was 78 months. Breast failure rates were assessed in relation to the sequencing of radiotherapy and chemotherapy. The different sequences were not randomly assigned, and the characteristics of the sequence groups differed. The actuarial 5-year breast failure rate was 4% in 99 patients receiving radiotherapy before chemotherapy; 8% in 54 patients sequentially receiving some chemotherapy, then radiotherapy without concurrent chemotherapy, then further chemotherapy; and 6% in 116 patients receiving concurrent chemotherapy and radiotherapy. However, the failure rate was 41% in 26 patients who received all chemotherapy before radiotherapy. The crude incidences of local failure within 4 years of treatment in these groups were 3%, 2%, 4%, and 15%, respectively (P = .065 for all four groups not being the same). The actuarial 5-year local failure rate was 5% for 252 patients irradiated within 16 weeks after surgery compared with 35% for 34 patients irradiated more than 16 weeks after surgery. The 4-year crude incidences were 4% and 12% for the two groups, respectively (P = .06). These results suggest that delaying the initiation of radiotherapy may result in an increased likelihood of local failure. Formal randomized controlled trials will be needed to confirm these results and to improve the integration of these treatment modalities.  相似文献   
9.
The families of 12 probands with classic mitral valve prolapse were studied for evidence of mitral valve prolapse. Seventy parents, sibs, and progeny were included in the analysis. Forty-seven percent (16 of 34) of progeny were affected compared with 30 percent (3 of 10) of parents. Thirty-eight percent (10 of 26) of sibs were affected. A three-compartmental penetrance model was devised to account for the variation in expression with age. This includes a latent stage (time before onset of signs), an affected stage, and a stage in which the subjects are withdrawn (because of treatment, regression, or death). The implications of this model are discussed.  相似文献   
10.
Fifteen patients with idiopathic hypertrophic subaortic stenosis had a ventricular extrasystole induced with a new external mechanical cardiac stimulator during noninvasive evaluation of left ventricular outflow tract obstruction. Ten patients were monitored with simultaneous echocardiogram, phonocardiogram and indirect carotid pulse tracing; five were monitored with the phonocardiogram and indirect carotid pulse tracing alone. Nine of the 15 patients showed obstruction in the beat after the ventricular extrasystole, as defined by appearance of the characteristic bifid carotid pulse contour and, where recorded, an increase in systolic anterior motion of the mitral valve on echocardiography. Six patients did not show obstruction. All nine patients with obstruction had greater than 20 msec prolongation of uncorrected systolic ejection time in the post-extrasystolic beat of the carotid pulse tracing. Change in the uncorrected ejection time was + 0.038 ± 0.015 second (mean ± standard deviation) in these nine patients compared with − 0.003 ± 0.005 second in the six not showing obstruction (P < 0.01). Six patients underwent cardiac catheterization: Three patients without obstruction after a noninvasively induced ventricular extrasystole had no obstruction at catheterization and three patients with obstruction after noninvasively induced ventricular premature beats demonstrated obstruction at rest or after provocative maneuvers during catheterization. These results indicate that the noninvasive induction of a ventricular extrasystole is a useful and easily performed procedure for both diagnosing and evaluating the dynamic left ventricular outflow tract obstruction of idiopathic hypertrophic subaortic stenosis.  相似文献   
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