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51.
Escherichia coli strains of phylogenetic group B2 obtained from Western human hosts are enriched in virulence-associated genes and have a superior capacity to persist in the colonic microbiota. Here, E . coli strains from 22 infants born in Pakistan whose rectal flora was sampled regularly over the first 6 months of life were examined. B2 strains did not carry the virulence-associated genes sfaD/E , papC , neuB or hlyA more often than strains of other phylogenetic groups . B2 origin was not associated with persistence in the bowel microbiota. As compared with B2 strains from Swedish infants, Pakistani B2 strains carried significantly less often the virulence genes fimH (p 0.04), papC (p 0.02), papG class III (p 0.01), sfaD / E (p ≤0.0001), neuB (p ≤0.0001), and hlyA (p 0.005), and also the high-pathogenicity island (p ≤0.0001). A minority of Pakistani B2 strains belonged to recognized uropathogenic O-groups, which are common among 'Western' B2 strains. Thus, extra-intestinal pathogenicity may be the foremost characteristic of B2 strains colonizing Western populations.  相似文献   
52.
Proton (1H) MRS enables non‐invasive biochemical assay with the potential to characterize malignant, benign and healthy breast tissues. In vitro studies using perchloric acid extracts and ex vivo magic angle spinning spectroscopy of intact biopsy tissues have been used to identify detectable metabolic alterations in breast cancer. The challenges of 1H MRS in vivo include low sensitivity and significant overlap of resonances due to limited chemical shift dispersion and significant inhomogeneous broadening at most clinical magnetic field strengths. Improvement in spectral resolution can be achieved in vivo and in vitro by recording the MR spectra spread over more than one dimension, thus facilitating unambiguous assignment of metabolite and lipid resonances in breast cancer. This article reviews the recent progress with two‐dimensional MRS of breast cancer in vitro, ex vivo and in vivo. The discussion includes unambiguous detection of saturated and unsaturated fatty acids, as well as choline‐containing groups such as free choline, phosphocholine, glycerophosphocholine and ethanolamines using two‐dimensional MRS. In addition, characterization of invasive ductal carcinomas and healthy fatty/glandular breast tissues non‐invasively using the classification and regression tree (CART) analysis of two‐dimensional MRS data is reviewed. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   
53.
This paper summarises results from an evaluation of the adequacy and utility of the Australian Competency Standards for Entry-Level Occupational Therapists © (OT AUSTRALIA, 1994a). It comprised a two-part study, incorporating an online survey of key national stakeholders ( n  = 26), and 13 focus groups ( n  = 152) conducted throughout Australia with occupational therapy clinicians, academics, OT AUSTRALIA association and Occupational Therapy Registration Board representatives, as well as university program accreditors. The key recommendations were that: (i) urgent revision to reflect contemporary practice, paradigms, approaches and frameworks is required; (ii) the standards should exemplify basic competence at graduation (not within two years following); (iii) a revision cycle of five years is required; (iv) the Australian Qualifications Framework should be retained, preceded by an introduction describing the scope and nature of occupational therapy practice in the national context; (v) access to the standards should be free and unrestricted to occupational therapists, students and the public via the OT AUSTRALIA (national) website; (vi) the standards should incorporate a succinct executive summary and additional tools or templates formatted to enable occupational therapists to develop professional portfolios and create working documents specific to their workplace; and (vii) language must accommodate contextual variation while striking an appropriate balance between providing instruction and encouraging innovation in practice.  相似文献   
54.
Despite a well-documented gender pattern in adolescent mental health, research investigating possible explanatory factors from a gender-theoretical approach is scarce. This paper reports a grounded theory study based on 29 focus groups. The aim was to explore 16- to 19-year-old students' perceptions of what is significant for mental health, and to apply a gender analysis to the findings in order to advance understanding of the gender pattern in adolescent mental health. Significant factors were identified in three social processes categories, including both positive and negative aspects: (1) social interactions, (2) performance and (3) responsibility. Girls more often experienced negative aspects of these processes, placing them at greater risk for mental health problems. Boys' more positive mental health appeared to be associated with their low degree of responsibility-taking and beneficial positions relative to girls. Negotiating cultural norms of femininity and masculinity seemed to be more strenuous for girls, which could place them at a disadvantage with regard to mental health. Social factors and processes (particularly responsibility), gendered power relations and constructions of masculinities and femininities should be acknowledged as important for adolescent mental health.  相似文献   
55.
Many have questioned whether it is ethical to assign participants in a research trial to a non-active control condition (e.g., a placebo or attention-only control) when (a) the disorder under study is serious, (b) validated treatment is available, and (c) harm may occur if treatment is not given. This ethical concern may apply to studies of controlled trials of treatments for drug dependence. The current paper examines this concern for trials of nicotine dependence because there are multiple validated treatments available. The major harm from assignment to a non-active condition in such a trial could occur if failure to quit discourages smokers from trying to quit again. Whether this harm actually occurs is unclear. Potential harms from non-active conditions may be mitigated by (a) provision of more explicit information in the consent process, (b) inclusion of only those who have failed optimal treatment, (c) provision of validated treatment via a different modality, (d) tests of the new treatment as an add-on to standard treatment, (e) use of dose–response design, (f) use of unequal randomization designs, (g) use of stopping rules, (h) provision of optimal therapy to those who fail during the study, or (i) comparison of the experimental treatment vs. standard treatment. Empirical research to inform ethical analysis of non-active conditions in drug abuse research is suggested.  相似文献   
56.
A study of the methylation of N‐nosyl‐α‐amino acids and derivatives with trimethylsilyldiazomethane is here reported. Trimethylsilyldiazomethane allows the chemo‐specific methylation of the carboxyl function of N‐nosyl‐α‐amino acids in high yields and purity. This method provides a practical route to N‐methyl‐α‐amino acids avoiding the use of the more toxic and explosive diazomethane. This simple and safe methylation methodology of α‐amino acids and derivatives is not limited to organic synthesis and involves the use of a commercially available reagent as well.  相似文献   
57.
Objective: Performance validity test (PVT) research studies commonly utilize a known-groups design, but the criterion grouping approaches within the design vary greatly from one study to another. At the present time, it is unclear as to what degree different criterion grouping approaches might impact PVT classification accuracy statistics. Method: To analyze this, the authors used three different criterion grouping approaches to examine how classification accuracy statistics of a PVT (Word Choice Test; WCT) would differ. The three criterion grouping approaches included: (1) failure of 2+ PVTs versus failure of 0 PVTs, (2) failure of 2+ PVTs versus failure of 0–1 PVT, and (3) failure of a stand-alone PVT versus passing of a stand-alone PVT (Test of Memory Malingering). Results: When setting specificity at ≥.90, WCT cutoff scores ranged from 41 to 44 and associated sensitivity values ranged from .64 to .88, depending on the criterion grouping approach that was utilized. Conclusions: When using a stand-alone PVT to define criterion group status, classification accuracy rates of the WCT were higher than expected, likely due to strong correlations between the reference PVT and the WCT. This held true even when considering evidence that this grouping approach results in higher rates of criterion group misclassification. Conversely, when using criterion grouping approaches that utilized failure of 2+ PVTs, accuracy rates were more consistent with expectations. These findings demonstrate that criterion grouping approaches can impact PVT classification accuracy rates and resultant cutoff scores. Strengths, weaknesses, and practical implications of each of the criterion grouping approaches are discussed.  相似文献   
58.
59.
Summary Dermatologic, ophthalmologic, and neurologic examinations were carried out on 33 patients with clinical symptoms of xeroderma pigmentosum (XP). Complementation groups were determined for 23 patients. Types of tumors and complementation group were found to be related in the following way: In the XP variant groups basaliomas were the most frequently occurring malignant tumors, whereas in the D group pigmentary tumors, such as melanotic precanceroses and melanomas prevailed; in the A and the C group, spinaliomas seem to be the most frequent malignomas. The DNA repair activity was measured using colony-forming ability and unscheduled DNA synthesis. Colony-forming ability was quantitated as a function of 12 different UV doses and expressed in terms of D0. Unscheduled DNA synthesis was determined autoradiographically by establishing dose-response curves, which analyzed by the characteristic value of linear regression. G0, defined as the linear increase in the mean number of silver grains per nucleus when the UV dose is multiplied by the factor of e (i. e., 2.72), was derived from the slopes of the regression lines. The repair capability of XP fibroblast lines was classified on the basis of D0 and G0.Abbreviations XP Xeroderma pigmentosum - UV ultraviolet light - Me2SO dimethyl sulfoxide Supported by the Deutsche Forschungsgemeinschaft, SFB 136Dedicated to Prof. U. W. Schnyder in honour of his 60th birthday  相似文献   
60.
This introduction traces the increasing awareness of the prevalence of child sexual abuse over the last 20 years, examines the nature and consequences of such abuse and summarizes current information on the use of group treatment and its evaluation with sexually abused children and adolescents and their parents. Four examples of group treatment with different populations of abused children are described in this issue.  相似文献   
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