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991.
Genetic diagnosis of hereditary tumors has progressed extensively and contributed to the presymptomatic testing for mutation carriers. This evolution of genetic testing for cancer susceptibility leads to improved prevention and early detection of cancers. However, the benefits and limits of testing, and the range of prevention and treatment are different in each hereditary tumor. The American Society of Clinical Oncology (ASCO) made the statement on genetic testing for cancer susceptibility and showed three categories for consideration of cancer predisposition testing. They recommend that genetic testing should be offered only for the categories including well-defined tumors. We described the characteristics of hereditary tumors in the three categories and discussed the significance of genetic testing for each tumor. In conclusion, genetic testing for cancer susceptibility should be applied only for subsets of hereditary syndromes, and it is important to continue the analysis of the significance (frequency or penetrance) of mutations of cancer predisposition genes and to make clear the genotype-phenotype and other correlations.  相似文献   
992.
993.
Among 145 patients treated with recombinant human growth hormone (GH), four developed sleep apnea (two obstructive, two mixed) associated with tonsillar and adenoidal hypertrophy in three. These four patients had no local risk factors predisposing to upper airway obstruction (i.e., frequent pharyngitis or sinusitis). Clinical and/or polysomnographic features of sleep apnea improved following cessation of GH therapy in one patient, and following tonsillectomy and adenoidectomy in all patients. The present observations indicate that, albeit rarely, obstructive and/or central sleep apnea may occur in children treated with GH. Polysomnography should be considered if symptoms of snoring, interrupted sleep, daytime somnolence-particularly if associated with tonsillar hypertrophy-appear in children during GH therapy.  相似文献   
994.
A bacterial cytochrome c peroxidase was purified from the obligate methanotroph Methylococcus capsulatus Bath in either the fully oxidized or the half reduced form depending on the purification procedure. The cytochrome was a homo-dimer with a subunit mol mass of 35.8 kDa and an isoelectric point of 4.5. At physiological temperatures, the enzyme contained one high-spin, low-potential (Em7 = -254 mV) and one low-spin, high-potential (Em7 = +432 mM ) heme. The low-potential heme center exhibited a spin-state transition from the penta-coordinated, high-spin configuration to a low-spin configuration upon cooling the enzyme to cryogenic temperatures. Using M. capsulatus Bath ferrocytochrome c555 as the electron donor, the KM and Vmax for peroxide reduction were 510 +/- 100 nM and 425 +/- 22 mol ferrocytochrome c555 oxidized min-1 (mole cytochrome c peroxidase)-1, respectively.  相似文献   
995.
BACKGROUND: A central problem in practice guideline development is how to develop guidelines that appropriately account for variations in clinical populations and practice settings. Despite recognition of this problem, there is no formal mechanism for assessing what the need is for flexibility in guidelines, or for deciding how to incorporate such flexibility into recommendations. OBJECTIVE: This research sought to provide a formal basis to determine when clinical circumstances vary sufficiently that guideline recommendations should differ, how recommendations should be tailored for a specific clinical setting, and whether the benefit associated with such site-specific guidelines justifies the expense of their development. RESULTS: The authors describe an approach for estimating the maximum health benefit that developers can obtain by eliminating uncertainty about differences in the patient populations and practice settings in which a guideline will be used. This estimate, the expected value of customization, provides a mechanism to evaluate the cost-effectiveness of the development of site-specific guidelines that account explicitly for variation in clinical circumstances. Application of this method to the development of screening guidelines for human immunodeficiency virus (HIV) infection indicates that the development of site-specific guidelines potentially is cost-effective. Site-specific guidelines either improve, or leave unchanged, the efficiency of HIV screening; whether they increase or decrease total expenditures and health benefits depends on the choice of a cost-effectiveness threshold, and the clinical problem. CONCLUSIONS: Development of guideline recommendations based on decision models provides a normative approach for evaluating the need for and the cost-effectiveness of site-specific guidelines that have been tailored to specific practice settings. Such site-specific guidelines can improve substantially the expected health benefit and the economic efficiency of practice guidelines.  相似文献   
996.
RepA, the initiator protein of plasmid P1, binds to multiple sites (iterons) in the origin. The binding normally requires participation of chaperones, DnaJ, DnaK and GrpE. When purified, RepA appears dimeric and is inactive in iteron binding. On reaction with chaperones, a species active in iteron binding is formed and found to be monomeric. To test whether the chaperones can reduce dimerization, RepA was used to replace the dimerization domain of the lambda repressor. The hybrid protein repressed the lambda operator efficiently, indicating that RepA can dimerize in vivo. A further increase in repressor activity was seen in dnaJ mutant cells. These results are consistent with a chaperone-mediated reduction of RepA dimerization. We also found that RepA mutants defective in dimerization still depend on DnaJ for iteron binding. Conversely, RepA mutants that no longer require chaperones for iteron binding remain dimerization proficient. These results indicate that the chaperone dependence of RepA activity is not solely owing to RepA dimerization. Our results are most simply explained by a chaperone-mediated conformational change in RepA protomer that activates iteron binding. This conformational change also results in reduced RepA dimerization.  相似文献   
997.
OBJECTIVES: To describe the experience of two male fertility programs using electroejaculation (EEJ) in the management of men with ejaculatory failure secondary to diabetes mellitus. METHODS: Twenty-nine EEJ procedures were performed in 7 diabetic men with ejaculatory failure. Results were reviewed with attention paid to sperm characteristics in both antegrade and retrograde specimens as well as pregnancy rates. RESULTS: Retrograde semen specimens retrieved from the bladder following EEJ contained a mean of 3444.5 million sperm (range 269.2 to 4996 million). Antegrade specimens contained a mean of 698.8 million sperm (range 226.8 to 1961 million). Mean sperm motility was 4% for retrograde specimens (range 0% to 11%) and 7% for antegrade specimens (1% to 15%). In all but 1 case, semen specimens were used for intrauterine insemination. The total number of motile sperm contained in the processed, inseminated specimens ranged from 1 to 87.2 million. In 1 case, the sperm obtained through EEJ was used in an in vitro fertilization procedure. CONCLUSIONS: EEJ can be successfully used to obtain sperm from men with ejaculatory failure due to diabetes mellitus. The procedure requires general anesthesia, and pregnancy rates after intrauterine insemination with the processed sperm are low. Advanced reproductive technologies may offer a feasible alternative, providing higher success rates with fewer procedures.  相似文献   
998.
OBJECTIVES: A 10-month direct mail campaign was implemented to increase use of emergency medical services via 911 calls and to reduce prehospital delay for individuals experiencing acute myocardial infarction symptoms. METHODS: This prospective, randomized, controlled trial involved three intervention groups (receiving brochures with informational, emotional, or social messages) and a control group. RESULTS: Intervention effects were not observed except for individuals who had a history of acute myocardial infarction and who were discharged with a diagnosis of acute myocardial infarction; their 911 use was meaningfully higher in each intervention group than in the control group. CONCLUSIONS: The mailings affected only the individuals at greatest risk.  相似文献   
999.
The elaboration of new mortality tables by the Swiss statistical office has allowed to estimate the impact of different pathology or risk factors on the average life duration of the resident population in Switzerland. Thus, attributable death of the smoking habits have for effect to decrease the life expectancy of swiss citizens of 2.9 years for men and 0.7 years for women, for the period 1988/1993. The calculation of mortality rates attributable to this factor of risk shows nevertheless that the risk of death has decreased since the end of years 1960 for all quinquennial age groups between 35 and 74 years. The smoking habits would be responsible of approximately 16% of deaths observed in the swiss population and 20% of premature deaths (between 25 and 64 years). The present analysis shows furthermore that different evolutions of the mortality associated with the smoking habits characterize men and women.  相似文献   
1000.
We attempted to replicate the three-dimensional factor structure of a previously proposed ADL scale and demonstrate an association between the advanced ADL dimension and cognitive function. Data used in these analyses were baseline assessments of health and functional status of hospitalized patients enrolled in a randomized controlled trial of case managers as a means of reducing health care utilization. We submitted 14 items from the OARS to a two-stage process of principal components factor analysis. Four significant dimensions emerged that were remarkably similar to the advanced, basic, and household ADL dimensions reported by Wolinsky and Johnson (1991). In this sample of hospitalized patients, however, incontinence emerged as a weak fourth dimension. Multiple regression of SPMSQ mental status examination scores on these ADL dimensions demonstrates the association between cognitive function and the advanced ADL dimension. These data confirm that the underlying structure of ADLs consists of at least three separate dimensions, one of which is aligned with cognitive capacity.  相似文献   
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