全文获取类型
收费全文 | 34950篇 |
免费 | 2648篇 |
国内免费 | 95篇 |
专业分类
耳鼻咽喉 | 334篇 |
儿科学 | 1043篇 |
妇产科学 | 902篇 |
基础医学 | 5340篇 |
口腔科学 | 472篇 |
临床医学 | 4990篇 |
内科学 | 6167篇 |
皮肤病学 | 700篇 |
神经病学 | 3910篇 |
特种医学 | 806篇 |
外科学 | 3177篇 |
综合类 | 276篇 |
现状与发展 | 1篇 |
一般理论 | 33篇 |
预防医学 | 3725篇 |
眼科学 | 606篇 |
药学 | 2285篇 |
中国医学 | 42篇 |
肿瘤学 | 2884篇 |
出版年
2024年 | 32篇 |
2023年 | 278篇 |
2022年 | 428篇 |
2021年 | 890篇 |
2020年 | 594篇 |
2019年 | 925篇 |
2018年 | 1099篇 |
2017年 | 855篇 |
2016年 | 938篇 |
2015年 | 971篇 |
2014年 | 1373篇 |
2013年 | 1772篇 |
2012年 | 2798篇 |
2011年 | 2882篇 |
2010年 | 1562篇 |
2009年 | 1419篇 |
2008年 | 2426篇 |
2007年 | 2497篇 |
2006年 | 2255篇 |
2005年 | 2350篇 |
2004年 | 2094篇 |
2003年 | 1954篇 |
2002年 | 1833篇 |
2001年 | 243篇 |
2000年 | 137篇 |
1999年 | 288篇 |
1998年 | 391篇 |
1997年 | 321篇 |
1996年 | 236篇 |
1995年 | 238篇 |
1994年 | 191篇 |
1993年 | 178篇 |
1992年 | 119篇 |
1991年 | 107篇 |
1990年 | 88篇 |
1989年 | 96篇 |
1988年 | 78篇 |
1987年 | 67篇 |
1986年 | 59篇 |
1985年 | 50篇 |
1984年 | 71篇 |
1983年 | 52篇 |
1982年 | 59篇 |
1981年 | 66篇 |
1980年 | 66篇 |
1979年 | 31篇 |
1978年 | 30篇 |
1977年 | 37篇 |
1976年 | 29篇 |
1974年 | 24篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
82.
V. Leroy Young Mary K. Seaton Christine A. Feely Cynthia Arfken Dorothy F. Edwards Carolyn M. Baum Samuel Logan 《American journal of industrial medicine》1995,27(3):419-431
On-site testing of 157 poultry processors disclosed that 50% had three or more abnormal upper extremity findings out of a total of 22 possibles. The average worker had five to six abnormal findings. Impaired pinch strength, decreased vibration sensitivity in the fingertips, and reports of current numbness were the most prevalent. Of workers with signs, 25% reported no symptoms, whereas only 8% of workers reported symptoms but had no signs. The investigators concluded that this measurement method has utility for assessments of worker populations to determine prevalence of CTDs and, potentially, for preclinical detection of these disorders to permit early intervention, reduce medical costs, and minimize disability. The need for accurate measurement to enhance early detection and prevention is discussed. 相似文献
83.
Steven M Kawut Darren B Taichman Vivek N Ahya Sandra Kaplan Christine L Archer-Chicko Stephen E Kimmel Harold I Palevsky 《Liver transplantation》2005,11(9):1107-1111
It is not known whether patients with pulmonary arterial hypertension associated with portal hypertension (portopulmonary hypertension (PPHTN) have different disease characteristics from those of patients with other forms of pulmonary arterial hypertension. We performed a retrospective cohort study of patients with PPHTN and patients with pulmonary arterial hypertension that was idiopathic, familial, or associated with anorexigen use (IPAH) to determine whether hemodynamics or survival were different between these groups. We included consecutive patients who underwent initial pulmonary artery catheterization and vasodilator testing at our center between January 1997 and May 2001 and who were followed until January 2004. Patients with PPHTN (N = 13) had a higher cardiac index and lower pulmonary vascular resistance than patients with IPAH (N = 33) (P < or = 0.001). Right atrial pressure and pulmonary artery pressure were similar between the groups. Patients with PPHTN had a higher risk of death in multivariate analysis (hazard ratio: [HR] = 2.8, 95% CI 1.04-7.4; P = 0.04). These findings were not affected by adjustment for differences in laboratory values, hemodynamics, or therapy. In conclusion, patients with PPHTN have a higher risk of death than that of patients with IPAH, despite having a higher cardiac index and lower pulmonary vascular resistance. Future studies of the specific mechanisms of and therapy for pulmonary arterial hypertension should focus on the distinctions between the different forms of this disease. 相似文献
84.
85.
86.
Kathleen Wermke Christine Hauser Gerda Komposch Angelika Stellzig 《The Cleft palate-craniofacial journal》2002,39(3):285-294
OBJECTIVE: The objectives of the present study were: (1) to analyze the cry features of infants with cleft lip and palate (UCLP) by means of spectral analysis, (2) to describe changes of the acoustic parameters from birth until 9 months of age, and (3) to compare these data with existing cry data of infants without cleft (control group). DESIGN: The study was designed on a interdisciplinary, prospective, and longitudinal basis. SETTING: Interdisciplinary study: (1) Institute of Anthropology at the Humboldt-University, Berlin; (2) Heidelberg University Hospital: Interdisciplinary Cleft Palate and Craniofacial Center. PATIENTS AND METHOD: The cry parameters of five patients with complete unilateral cleft lip, alveolar ridge, and hard and soft palate were analyzed from birth to 9 months of age. The patients were treated with the same protocol. At the age of 24 months, sensomotor development was assessed using the KIPHARD test. Perceptual judgment of speech, performed after 36 months of life, included nasal resonance, nasal emission of air, articulation disorders, and speech intelligibility. MAIN OUTCOME MEASURE: The cry parameters of fundamental frequency (F(0)), pitch period perturbation quotient (PPQ), and cry duration (Tsam) were analyzed. RESULTS: Contrary to the expectation that laryngeal parameters are not affected by vocal tract malformations, differences of cry parameters were found between the patients with UCLP and the non-cleft group. Particularly, the F(0) and its short-time variability (PPQ) were affected. CONCLUSIONS: The preliminary results of this study showed that F(0) and PPQ of spontaneous cries are influenced in patients with UCLP, and a cry analysis might become a noninvasive tool for early detection of an at-risk status for neuromuscular development and prediction of an at-risk status for later speech and language acquisition in infants with cleft lip and palate. Future research strategies are outlined. 相似文献
87.
Peter J. Franks PhD ; Hanne Winterberg RGN DN BSc ; Christine J. Moffatt RGN PhD 《Wound repair and regeneration》2002,10(3):133-140
Little is known of the impact of pressure ulceration on adult patients' health-related quality of life. The purpose of this study was to determine the impact pressure ulceration has on pressure ulcer patients cared for in the community. A case control study design was used by drawing a random sample from patients receiving community nursing care, stratified by the presence of pressure ulceration. In all, 75 patients with pressure ulcers were compared with 100 controls without ulcers using the four-point ulcer grading scale described by United Kingdom consensus guidelines. Patients were interviewed using the Short Form-36 (SF-36) questionnaire and activities of daily living assessed using the modified Barthel scale. Patients with pressure ulcers had significantly poorer physical function (mean difference (d) = 37.6, 95% CI 28.6-46.6, p < 0.001) and social functioning (d = 33.9, 95 % CI 24.0-43.9, p < 0.001) than published age- and sex-matched normative data from the United Kingdom. The difference between cases and controls was much smaller in these domains, with neither approaching statistical significance. After adjustment for age and gender, scores for bodily pain were poorer in patients with no ulceration (d = -10.5, 95% CI - 20.6 to - 0.4, p = 0.042) indicating greater pain in these patients compared with the cases with ulceration. Activities of daily living determined by the modified Barthel scale showed reduced self-care (d = -7.6, 95% CI -12.5 to - 2.7, p = 0.010) and mobility (d = -9.2, 95% CI -14.6 to - 3.8, p = 0.001) in patients with pressure ulceration. The overall ability to perform these activities was also significantly poorer in this group (d = -16.3, 95% CI -27.3 to -5.3, p = 0.004). While patients with pressure ulceration experience some deficits in their health-related quality of life compared with a normal population, these differences are similar to those experienced by other patients receiving community nursing care. 相似文献
88.
Lipodermatosclerosis: review of cases evaluated at Mayo Clinic. 总被引:1,自引:0,他引:1
Alison J Bruce Daniel D Bennett Christine M Lohse Thom W Rooke Mark D P Davis 《Journal of the American Academy of Dermatology》2002,46(2):187-192
BACKGROUND: Lipodermatosclerosis describes bound-down, sclerotic skin involving the lower extremities. OBJECTIVE: Our purpose was to describe the demographic and clinical features of patients with lipodermatosclerosis. METHODS: This was a retrospective study of patients presenting to Mayo Clinic between 1976 and 1998 with a diagnosis of lipodermatosclerosis. RESULTS: Of 97 patients, 84 (87%) were women. Mean age was 62 years (range, 25-88 years). Mean body mass index was 34.3 (range, 17.8-71.5). Clinical signs were bilateral involvement in 44 patients (45%), induration localized to a discrete plaque in 49 (51%), erythema in 69 (71%), hyperpigmentation in 57 (59%), ulceration in 13 (13%), concomitant edema in 69 (71%), and varicosities in 55 (57%). Vascular studies performed on 72 patients showed abnormalities in 49: deep venous incompetence in 33 (67%), calf muscle pump abnormality in 19 (39%), abnormal pulsatility in 10 (20%), and obstruction in 1 (2%). CONCLUSION: Lipodermatosclerosis was associated with female sex, middle age, high body mass index, and venous abnormalities. 相似文献
89.
Christine A. Ellis Susan F. Brooks Gavin Brooks A. Tudor Evans Nicholas Morrice Fred. J. Evans Alastair Aitken 《Phytotherapy research : PTR》1987,1(4):187-190
The sapintoxins are a series of naturally occurring fluorescent phorbol esters with a range of selective biological activities (e.g. pro-inflammatory but non-tumour promoting). Their ability to activate protein kinase C (PKC) in vitro has been studied. Both tumour promoting and non-promoting phorbol derivatives activate the enzyme in vitro at low concentrations. 12-deoxyphorbol-13-phenylacetate-20 acetate (DOPPA) acts as a partial agonist in the activation of protein kinase C. Structurally distinct phorbol esters may therefore preferentially activate different forms of protein kinase C. α-sapinine, a biologically inactive compound, binds to protein kinase C without stimulating the enzyme and prevents subsequent activation by phorbol esters such as 12-O-tetradecanoyl phorbol-13-acetate (TPA). 相似文献
90.