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951.
PURPOSE: The objective of this research is to describe aspects of the organization of adolescent sexual behavior in order to understand factors associated with risk for sexually transmitted diseases (STD). METHODS: Subjects were 82 females (ages 16-19 years; 77% African-American) participating in a larger STD study. Subjects completed diaries for each coital event, recording date of event, partner initial, condom use, and use of drugs or alcohol before intercourse. Partner change was defined as any event for which the sex partner initials differed from those listed for the most recent previous coital event. RESULTS: The 82 subjects recorded 1265 coital events; the average span of the records was 10 weeks. Intercourse was least likely on Sundays (154 of 1265; 12.2%) and most common on Friday and Saturday (221 of 1265 for each day; 17.5%). The proportion of coital events associated with drugs or alcohol increased from Sunday to Saturday, although the proportion of coital events in which a condom was used did not vary significantly. Intercourse was most common in spring and summer, and least frequent in winter. CONCLUSIONS: These data indicate substantial temporal organization of adolescent sexual behaviors that may be related to risk of sexually transmitted diseases. Some STD-preventive interventions may be most effective when targeted to higher risk times.  相似文献   
952.
Two prominent features associated with immunosenescence are thymic involution and altered T-cell phenotype and responsiveness. We have shown previously that in CD2-fas transgenic mice, in which the Fas apoptosis molecule is constituatively expressed on T cells, T-cell senescence is greatly reduced. Using a different experimental approach, the relationship between T-cell senescence and apoptosis was analyzed on human PBMCs. The results indicate that there was increased apoptosis of CD45RO- (CD45RA+) T cells upon activation. We propose that this could account for the increase in CD45RO+ 'memory' T cells with aging in humans. Together these results are consistent with the notion that T-cell senescence is associated with altered apoptosis and decreased T-cell responsiveness. T-cell responsiveness remained high in CD2-fas transgenic aged mice, but there was no increase in overall life span of the mice. Increased T-cell responsiveness was associated with an increased acute-phase response and amyloid A deposition in the glomerulus of these mice. These data suggest that restoration of the T-cell immune function in aged individuals must be carried out in concert with correction of other immune factors that down modulate the acute-phase response to prevent undesirable side-effects.  相似文献   
953.
The prognostic significance of steroid-receptor activity is still debatable. Discrepancies in results are probably attributable to few patients, heterogeneous patient populations, and short follow-up. We investigated the prognostic significance of estrogen- and progesterone-receptor (ER and PgR, respectively) activity as a continuous variable in a homogeneous patient population. The prognostic significance of steroid-receptor activity was examined in 329 node-negative and 320 node-positive unselected breast cancer patients. In node-negative patients, ER values of primary tumors between 100 and 400 fmol/mg protein appeared to be a significant predictor for low risk of recurrence, whereas high ER (> 400) revealed an unfavorable prognosis. The classic cutoff level of ER (< 10 fmol/mg proteins) had no prognostic significance, however. In patients receiving adjuvant chemotherapy--the node-positive breast cancer patients--the classic cutoff value of ER (10 fmol/mg protein) predicts significantly distant metastases-free survival and overall survival only in the first 4 years of follow-up after diagnosis. Progesterone receptor is a time-dependent prognosticator in node-negative breast cancer patients (cutoff point for PgR, 80 fmol/mg). In node-positive breast cancer patients treated with chemotherapy or a combination of chemo- and hormonal therapy, PgR values lower than 60 fmol/mg had a worse prognosis. The results show the poor performance of standard cutoff points for ER and PgR positivity in predicting prognosis. Better prognosis is related to higher receptor levels but this relation is predominantly time-dependent. Moreover, patients who have high ER levels have a prognosis that is worse when compared with intermediate ER levels. Standard cutoff points for steroid receptors should not be used to select patients for prognosis.  相似文献   
954.
We analyzed the pattern of failure and clinicopathologic factors influencing the disease-free survival of 78 patients who died after macroscopic curative resection for pancreatic cancer. Local recurrence was a component of failure in 56 patients (71.8%) and hepatic recurrence in 48 (61.5%), both accounting for 97% of the total recurrence rate. About 95% of recurrences occurred by 24 months after operation. Median disease-free survival time was 8 months, and cumulative 1-, 3-, and 5-year actuarial disease-free survival rates were 66%, 7%, and 3%, respectively. Multivariate analysis showed that tumor grade (p = 0.04), microscopic radicality of resection (p = 0.04), lymph node status (p = 0.01), and size of the tumor (p = 0.005) were independent predictors of disease-free survival. Patterns of failure and disease-free survival were not statistically influenced by the type of surgical procedure performed. Median survival time from the detection of recurrence until death was 7 months for local recurrence versus 3 months for hepatic or local plus hepatic recurrence (p < 0.05). From our experience and the data collected from the literature, it appears that surgery alone is an inadequate treatment for cure in patients with pancreatic carcinoma. Effective adjuvant therapies are needed to improve locoregional control of pancreatic cancer after surgical resection.  相似文献   
955.
To investigate whether aerosolized gentamicin (GM) prevents myeloperoxidase (MPO)-mediated airway injury and mucus hypersecretion, a short course of aerosol therapy (3 d) with GM 40 mg or 0.45% saline (saline) twice per day was conducted. Twenty-eight patients with bronchiectasis and mucus hypersecretion after adequate chest care and hydration were enrolled in a randomized, double-blind fashion. MPO levels in sputum collected on arising were determined by fluorometric assay at 655 nm before and after treatment. The sputum MPO level significantly decreased in patients receiving aerosolized GM, from 0.22 +/- 0.04 to 0.14 +/- 0.04 U/g (n = 15), but not in patients with saline inhalation (0.23 +/- 0.03 to 0.17 +/- 0.02 U/g; n = 11). The daily sputum amount significantly decreased from 94.6 +/- 21.6 to 58.1 +/- 17.8 ml (n = 13, p < 0.01) in the GM group, whereas it increased from 78.6 +/- 25.4 ml to 120.5 +/- 33.9 ml (n = 11, p < 0.05) in the saline group. The change in the amount of daily sputum was related to that in the sputum MPO level in the GM group (r = 0.61; p < 0.01). Inhalation of GM, but not saline, significantly (p < 0.05) increased the value of peak expiratory flow (PEF) from 186.4 +/- 25.1 to 216.4 +/- 26.4 L/min and decreased the variability of PEF from 24.6 +/- 5.1 to 6.1 +/- 2.3 %. The nocturnal desaturation and the 6-min walking distances were also significantly improved in the GM group (11.2 +/- 3.8 to 0.6 +/- 0.5 min/h; 324.9 +/- 43.1 to 408.1 +/- 25.9 m; p < 0.05; respectively), but not in the saline group. Subjective improvements in the Borg scale and self-sputum assessment were found in the GM group only. In conclusion, aerosolized GM is effective in improving airway hypersecretion and inflammation in patients with bronchiectasis.  相似文献   
956.
OBJECTIVES: Clinical knowledge about myoelectrical frequency is well known, but the factors responsible for recorded myoelectrical amplitude remain less clear. METHODS: We assembled an electrogastrographic system that could automatically compute the dominant myoelectrical frequency and power and power ratio. We enrolled 50 healthy volunteers (25 men and 25 women) to study their myoelectrical characteristics. Three surface electrodes were placed in the fundic, stomach body, and antral positions for two 30-min recordings in the fasting and postprandial states. RESULTS: The three different electrodes recorded similar dominant frequencies of about 3 cpm before and after a meal. The fasting dominant powers from these electrodes were 52.9 +/- 14.7, 44.6 +/- 11.5, and 50.1 +/- 15.1 dB, respectively (p < 0.01), whereas the postprandial dominant powers were 61.6 +/- 28.8, 54.3 +/- 26.6, and 61.9 +/- 27.8 dB, respectively (p < 0.01). Meal ingestion did increase the power (p < 0.05). Women had a lower dominant power than men (p < 0.001). Moreover, the dominant powers of each electrode were significantly correlated with body mass index (r = 0.3-0.36, p < 0.05) regardless of meal ingestion. The postprandial power ratio was not influenced by electrode position, gender, or body mass index. CONCLUSIONS: Myoelectrical dominant frequencies and power ratios are similar throughout the whole stomach area, whereas a lower power area exists on the stomach body. Gender-related variation in dominant power seems to be an effect of body size. The power ratio is the only reliable parameter for expressing myoelectrical amplitude.  相似文献   
957.
The authors show the results of the "Curricular Evaluation Program" of University of S?o Paulo Medical School pertaining to the year of 1996. This program (PAC-II) is based on teachers' opinions regarding the subjects taught (1st to 4th grades) and hospital intern courses. The opinions collected concerning such programs were definitely favorable. Most of the teachers considered the programs to be either good or very good. It was also identified that the hospital intern courses were a little more valued than the other courses taught in the first four grades.  相似文献   
958.
Dual-energy X-ray absorptiometry (DXA), using a narrow pencil-shaped X-ray beam coupled to a single detector, has been used extensively. More recently, DXA using a fan- shaped X-ray beam coupled to an array of detectors has been introduced. This new generation of scanners causes an inherent magnification of scanned structures as the distance from the X-ray source decreases. This magnification, which occurs in the medial-lateral direction but not in the craniocaudal direction, does not affect bone mineral density (BMD). There are, however, significant changes of bone mineral content (BMC), bone area, and parameters of hip geometry, with varying distance of the bone scanned from the X-ray source. Variability of soft tissue thickness in vivo, by altering the distance of the skeleton from the scanning table and X-ray source, may cause clinically significant errors of BMC, bone area, and proximal femur geometry when measured using fan-beam densitometers. We analyzed the geometry of Lunar and Hologic fan beam scanners to derive equations expressing the true width of scanned structures in terms of the apparent width and machine dimensions. We also showed mathematic ally that performing an additional scan, at a different distance from the X-ray source than the first scan, provides simultaneous equations that can be solved to derive the real width of a scanned bone. This hypothesis was tested on the Lunar Expert using aluminium phantoms scanned at different table heights. There was an excellent correlation, r = 0.99 (p < 0.001), between the predicted phantom width and the measured phantom width. In conclusion, this study shows that the magnification error of fan beam DXA can be corrected using a dual scanning technique. This has important implications in the clinical usefulness of BMC and geometrical measurements obtained from these scanners.  相似文献   
959.
Hepatic artery thrombosis occurs in 4% to 10% of adult patients and in up to 26% of children undergoing liver transplantation. Aspirin has been used to prevent this complication but may increase procedure-related and gastrointestinal bleeding. The aim of this study was to assess the efficacy and safety of low-dose aspirin in the prophylaxis of hepatic artery thrombosis. The histories of 529 patients who survived liver transplantation between September 1988 and December 1993 were reviewed retrospectively. The routine clinical practice followed until 1992 was to initiate oral aspirin therapy on the first postoperative day (81 mg daily in adults and 40 mg daily in children) as prophylaxis for vascular thrombosis. This was done in 354 patients. Aspirin was not administered to the remaining 175 patients. Hepatic artery thrombosis occurred in 13 patients treated with aspirin (3.7%) and in 7 patients not treated with aspirin (4.0%) (P = .85). Recipient age of younger than 2 years and low donor liver weight were the only factors that predisposed the patients to hepatic artery thrombosis. A total of 1,651 percutaneous liver biopsies were performed in this series, with 1,111 performed in patients treated with aspirin. Significant bleeding after liver biopsy occurred in 12 patients treated with aspirin (1.1%) and in 3 patients not treated with aspirin (0.6%) (P = .29). Gastrointestinal bleeding occurred in 66 patients treated with aspirin (18.9%) and in 23 patients not treated with aspirin (12.8%) (P = .08). Low-dose aspirin therapy is not shown to be effective in preventing hepatic artery thrombosis after liver transplantation. Although aspirin does not produce a statistically significant increase in the risk of bleeding after liver biopsy, there is a trend toward an increased incidence of gastrointestinal bleeding.  相似文献   
960.
En-bloc double lung transplantation with tracheal anastomosis and direct revascularization of the bronchial arteries to the left internal mammary artery has been carried out in Denmark since June 1992. Forty-seven patients (32 with alfa-1 antitrypsin deficiency, 11 with chronic obstructive pulmonary disease, two with cystic fibrosis and two with primary pulmonary hypertension), 25 men and 22 women, average age 39 years (17-64 years), have received their first double-lung transplant with bronchial artery revascularization. Arteriography of the internal mammary artery and bronchial arteries was performed in 42 (89%) of the patients from 1-150 days after the operation. Successful bronchial artery revascularization was demonstrated arteriographically in 40 patients, in two patients the arteriography failed to show bronchial artery revascularization. Arteriography was not performed in five patients due to early complications and death. Bronchoscopy showed rapid, uncomplicated airway healing in 42 patients. Mucosal necrosis under the tracheal anastomosis was found in three patients, and severe obstructive endobronchial growth of the fungus Aspergillus fumigatus was diagnosed in the last two patients. The one- and two-year survival is 83% (Kaplan-Meier). Eleven patients are dead, five due to pulmonary causes and six due to extra-pulmonary causes. Pulmonary function became normal in nearly all surviving patients between three to six months after the transplantation. In conclusion, en-bloc double-lung transplantation with bronchial artery vascularization has shown good short-term results, and the one- and two-year survival gives hope that a successful bronchial artery revascularization will improve the long-term survival following lung transplantation.  相似文献   
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