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991.
OBJECTIVE: To examine the relationships between the distribution and composition of subfractions of very low density (VLDL), low density (LDL) and high density (HDL) lipoproteins and central fat deposition as measured by the waist-to-hip ratio (WHR). DESIGN: Participants (n = 62, 44 women and 18 men; body mass index (BMI) > or = 25.0) were recruited from those consecutively attending the outpatient obesity clinic at the University Hospital, Geneva. MEASUREMENTS: Lipoprotein subfractions were isolated from fasting blood samples by cumulative flotation or density gradient ultracentrifugation. Concentration and composition were analysed as a function of obesity indices. RESULTS: There were significant correlations between the WHR and the profiles of the three major lipoprotein subclasses. Central obesity was associated with larger VLDL, small, dense LDL and lower levels of HDL-2 independently of other indices of obesity and plasma triglycerides. Central obesity was also significantly and independently associated with compositional anomalies, specifically an increased free cholesterol content of VLDL and LDL. CONCLUSIONS: Central body fat was associated with modifications of an atherogenic nature to lipoprotein distribution and composition. The data are consistent with an impact of body fat distribution on cardiovascular disease (CVD) via the agency of modified lipoprotein metabolism independently of raised triglycerides.  相似文献   
992.
993.
The nucleotide sequence of the 3.5-kb right junction fragment of the streptococcal conjugative transposon Tn5252 was obtained. The DNA fragment was found to carry four putative genes one of which displayed a high degree of similarity to prokaryotic 5C-cytosine methyltransferases carrying multiple sequence specificities. No cognate endonuclease gene was detected in the sequenced DNA. Purified methylase polypeptide synthesized in a T7 promoter-controlled overexpression system was found to lack methylase activity while the cell extracts of host cells containing the recombinant plasmid carrying the methylase gene were active. In vivo mutations in the methylase gene did not seem to affect the transferability of the element.  相似文献   
994.
Nasal chondromesenchymal hamartoma is the suggested appellation for a tumefactive process of the nasal passages and contiguous paranasal sinuses in seven children with a detectable mass in the nose. With the exception of one patient who was 7 years of age at diagnosis, the others were 3 months of age or less upon recognition of the mass. Two children were diagnosed in the first 2 weeks of life. Imaging studies showed a complex solid and cystic mass or masses filling the nasal cavity and extending into the ethmoid sinuses in most cases. Erosion of the surrounding bone, including the cribriform plate, resulted in an intracranial component in the four cases. Surgical resection was the treatment of choice despite its technical difficulties that often necessitated a combined intranasal and intracranial approach. Residual disease with continued growth in one case was the clinical outcome in two children, and the remaining five patients have not experienced any further difficulties. The piecemeal fragments of tissue disclosed a collage of histologic features, but the basic morphologic elements were well-demarcated nodules of cartilage with some variation in the cellular density and maturation of the chondrocytes, a myxoid to spindle cell stroma, focal osteoclastlike giant cells in the stroma, and erythrocyte-filled spaces resembling those of the aneurysmal bone cyst. Two of the tumors were less polymorphous or complex in their spectrum of histologic features. These nasal masses have similarities to the so-called chest wall hamartoma or mesenchymal hamartoma of the chest wall in terms of the clinical presentation in infancy and the basic cartilaginous character of both entities. There is a degree of presumption in the designation of these nasal and chest wall tumors as hamartomas because the pathogenesis has not been established for either entity.  相似文献   
995.
The prostate is an androgen-regulated organ, which has led to long-standing interest in the role of androgens in prostate carcinogenesis. Although evidence of a hormonal etiology for prostate cancer is strong, it is almost entirely circumstantial. Much of the problem in proving a causal relationship relates to the continued difficulties in reliably measuring human tissue-specific exposure to endogenous steroid hormones. The international and racial-ethnic variations in prostate cancer incidence, combined with the effects of migration on risk patterns, have suggested that whereas environmental factors are likely to be important, genetic factors might also play a central role in determining prostate cancer risk. We are developing a polygenic model of prostate carcinogenesis focused around a series of genes involved in androgen biosynthesis and androgen activation, transport, and metabolism in the prostate. In this developing model, we have initially targeted four genes based on three main criteria: (a) all encode products that play important roles in inducing androgen stimulation in the prostate; (b) all are polymorphic; and (c) all show substantial allelic variation in the polymorphic marker among the racial-ethnic groups of greatest interest in terms of prostate cancer risk. In addition to studying how the polymorphic markers of interest are related to prostate cancer development within and between racial-ethnic groups, we are concurrently evaluating whether genotypic variations correlate in the anticipated direction with biochemical parameters in vitro and in vivo. We summarize the development of this model and the state of knowledge related to each of the genes comprising the current model. We discuss the extent to which the current model can explain demographic variation in prostate cancer risk as well as the potential for future expansion of the model to incorporate environmental risk factors as well as additional genes. The model, when fully developed, can potentially provide a basis for targeting populations for screening interventions and/or preventive strategies aimed at the multigene products or at the genes themselves.  相似文献   
996.
BACKGROUND: Postoperative infection following cholecystectomy poses a significant threat to recovery, with major cost repercussions. Though antimicrobial prophylaxis is commonly practiced, its value - particularly in laparoscopic cholecystectomy - has not yet been adequately documented. METHOD: In a prospective multicenter quality assurance study in 28 German hospitals, an analysis of data collected on 4,477 patients undergoing conventional (n = 1,349) or laparoscopic (n = 3,128) cholecystectomy was performed; 2,217 patients received and 2,260 did not obtain perioperative antibiotic cover. RESULTS: Postoperative infections occurred in a total of 136 patients, with infection rates of 5.0% in those without prophylaxis, 0.8% in those on ceftriaxone, and 1.2% in those on other antibiotic regimens. Patients receiving prophylaxis fared significantly better than those with no prophylaxis in terms of the rate of postoperative wound infections, chest infections, other complications, reoperation and mortality. CONCLUSION: Neither laparoscopic nor conventional open cholecystectomy should be performed without adequate perioperative antimicrobial prophylaxis in future, especially since such measures also reduce hospital stay and hence the costs.  相似文献   
997.
BACKGROUND: To assess the efficiency and safety of intravenous antibiotic therapy (IAT) when performed through the traditional simple infusion system by gravity in the home setting. PATIENTS AND METHODS: The clinical records of patients undergoing intravenous antibiotic therapy through the traditional gravitational infusion system in the home care unit over a five year period were reviewed retrospectively. RESULTS: 120 patients were treated (44 F/76 M), with a mean age of 48 years (44-52). 67% of the total had chronic diseases. Infections were most commonly found in bones and joints (38%), followed by the skin and soft tissues. A wide variety of antibiotics was used, 61% as monotherapy. 76% of them were given intermittently. 161 intravenous catheters were used, 53% of which were central catheters with peripheral insertion, 27% inserted centrally and 20% peripheral catheters. The overall incidence of phlebitis was 18% without associated bacteremia. 91% of our patients evolved well, 6% had to become in-patients, none of them due to problems with the infusion system or by their own petition. The intravenous treatment lasted a mean of 17 days at home and 25 days at both home and hospital, which represents a decrease of 2,040 hospital stays. CONCLUSIONS: The traditional gravitational system of infusion is an effective and safe method for intravenous antibiotic administration at home. For these therapies to be successful, suitable patients must be selected and continuous attention is required. This treatment at home satisfies the patient and permits hospital stays to be reduced, thus improving the use of hospital resources.  相似文献   
998.
999.
The evaluation of gastric emptying by the double isotope technique involves some methodologic conditioning. Among them contamination correction or interference in the energy windows of the activity of the two isotopes used in the marking of the solids and fluids of the test food are important. The results of an experiment in which a phantom was used to evaluate the contamination between indio 111 (DTPA-Ca111In) and technecium 99m (colloid99mTc). Three test studies were posteriorly performed in healthy volunteers and 27 studies in a control group (13 males, mean age of 33 years, mean body mass index 39.02 kg/m). In these studies the contamination was corrected with the acquisition, following an initial swallow of juice marked with 111In, of activity in the windows of both isotopes. The contamination of 111In (isotope of greatest radiation energy) in the window of 99mTc was 24% in the phantom and 20%, 23% and 26% in the three initial study tests. The mean contamination in the control group was of 22% with limits of 19% to 29% and a standard deviation of 3%. Despite the comparable results, the usefulness of the individualized contamination calculation in the studies of gastric emptying with dual isotope to minimize the methodologic errors of this technique is discussed.  相似文献   
1000.
R. H. Logie and D. A. Baddeley (1987) suggested that event counting may be supported by a phonologically based working-memory structure referred to as the phonological loop. However, inconsistent results concerning the detrimental effects of irrelevant speech on event counting led them to propose that lexical or semantic representations are also involved. In 4 experiments, the authors showed that this extension of Logie and Baddeley's original conceptualization was unnecessary. Instead, the number of irrelevant syllables spoken per time unit, a factor that was not taken into account in previous research, can explain Logie and Baddeley's results. In addition, the present results support the hypothesis that in cases of interference from the auditory channel, correction processes that help to recover the current running total from past running totals are also involved in counting performance.  相似文献   
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