全文获取类型
收费全文 | 3331882篇 |
免费 | 244574篇 |
国内免费 | 5396篇 |
专业分类
耳鼻咽喉 | 47933篇 |
儿科学 | 105545篇 |
妇产科学 | 87834篇 |
基础医学 | 461791篇 |
口腔科学 | 93003篇 |
临床医学 | 297014篇 |
内科学 | 643769篇 |
皮肤病学 | 68260篇 |
神经病学 | 274631篇 |
特种医学 | 132816篇 |
外国民族医学 | 1082篇 |
外科学 | 503516篇 |
综合类 | 74487篇 |
现状与发展 | 2篇 |
一般理论 | 1216篇 |
预防医学 | 266374篇 |
眼科学 | 78082篇 |
药学 | 251912篇 |
11篇 | |
中国医学 | 7231篇 |
肿瘤学 | 185343篇 |
出版年
2018年 | 52741篇 |
2017年 | 40551篇 |
2016年 | 45118篇 |
2015年 | 33291篇 |
2014年 | 46460篇 |
2013年 | 69859篇 |
2012年 | 100568篇 |
2011年 | 117465篇 |
2010年 | 74082篇 |
2009年 | 64593篇 |
2008年 | 109550篇 |
2007年 | 117859篇 |
2006年 | 101430篇 |
2005年 | 99645篇 |
2004年 | 97132篇 |
2003年 | 94353篇 |
2002年 | 90955篇 |
2001年 | 150440篇 |
2000年 | 155953篇 |
1999年 | 131374篇 |
1998年 | 36816篇 |
1997年 | 33090篇 |
1996年 | 32774篇 |
1995年 | 31424篇 |
1994年 | 29376篇 |
1993年 | 27431篇 |
1992年 | 104406篇 |
1991年 | 100794篇 |
1990年 | 97704篇 |
1989年 | 94280篇 |
1988年 | 87201篇 |
1987年 | 85509篇 |
1986年 | 81113篇 |
1985年 | 77257篇 |
1984年 | 57828篇 |
1983年 | 49171篇 |
1982年 | 29134篇 |
1981年 | 25748篇 |
1979年 | 53873篇 |
1978年 | 37365篇 |
1977年 | 32123篇 |
1976年 | 29490篇 |
1975年 | 31790篇 |
1974年 | 38789篇 |
1973年 | 36876篇 |
1972年 | 34699篇 |
1971年 | 32239篇 |
1970年 | 30329篇 |
1969年 | 28464篇 |
1968年 | 25739篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
C.A. AMEZCUA H.R. MACDONALD† C.A. LUM W. YI‡ L.I. MUDERSPACH† L.D. ROMAN† & J.C. FELIX† 《International journal of gynecological cancer》2006,16(3):1336-1341
In this study, we examine the prevalence of finding isolated tumor cells (ITCs) in negative lymph nodes of endometrial cancer patients using immunohistochemistry. Seventy-six endometrial cancer patients with lymph nodes histologically negative for metastatic disease were examined. Nodal tissue sections were stained with anticytokeratin antibodies AE-1 and CAM 5.2. Nodes with single or groups of cells (two to four cells) < or =0.2 mm and showing cytokeratin reactivity were positive for ITCs. Findings were compared to features of the primary tumor and patient outcome. ITCs were present in 31 of 1712 lymph nodes. Fifteen (19.7%) patients had ITC-positive nodes. ITCs involved only pelvic nodes in nine cases, only para-aortic nodes in five cases, and pelvic and para-aortic in one case. Tumor in adnexa was the only pathologic feature associated with nodal ITCs (P= 0.0485). All 15 patients with nodal ITCs were alive at follow-up. One (6.7%) patient suffered recurrent disease but was alive at last encounter. Disease recurred in 5 (8.8%) of 57 patients without nodal ITCs. Two are alive without disease, two alive with disease, and one died from her cancer. In summary, a significant proportion of endometrial cancer patients have ITCs detected by immunohistochemistry in histologically negative regional lymph nodes. 相似文献
992.
PURPOSE: Concern over stigma as a consequence of genetic testing has grown in response to the recent increase in genetic research and testing resulting from the Human Genome Project. However, whether a genetic or hereditary basis necessarily confers a stigma to a condition remains unexamined. METHODS: We performed a qualitative interview study with 86 individuals with one of four conditions: deafness or hearing loss, breast cancer, sickle cell disease, and cystic fibrosis. The first two groups were divided approximately between people who ascribed their conditions to a genetic or hereditary cause and those who did not. RESULTS: Respondents interpreted genetic or hereditary causes and nongenetic causes in a variety of ways. Subjects with breast cancer reported the most consistently negative interpretation of genetic cause. This response concerned future ill health, not an enduring sense of stigma. Deaf and hard of hearing subjects provided the most consistently positive comments about a genetic or hereditary basis to their condition, casting familial hearing loss as a vital component of group and individual identity. Respondents with sickle cell disease and cystic fibrosis offered similar and positive interpretations of the genetic cause of their condition insofar as it meant their conditions were not contagious. CONCLUSIONS: Although some subjects report feeling stigmatized as a result of their condition, this stigmatization is not uniformly associated with the condition's cause, genetic or otherwise. Instead, stigma emerges from a variety of sources in the context of the lived experience of a particular condition. 相似文献
993.
Matthew J Matasar Ellen K Ritchie Nathan Consedine Carol Magai Alfred I Neugut 《European journal of cancer prevention》2006,15(4):367-370
Despite significant improvements in the prognosis of acute promyelocytic leukemia brought about by therapeutic advances, understanding of the epidemiology of acute promyelocytic leukemia remains limited. Earlier reports have suggested that Hispanics may have an increased incidence of acute promyelocytic leukemia, but no systematic analysis of national data has yet been reported. We performed a retrospective cohort study, using data from the Surveillance, Epidemiology, and End Results (SEER) Program of the National Cancer Institute from 1992-2001 in order to compare leukemia incidence rates as a function of race and ethnicity. We identified 709 cases of acute promyelocytic leukemia and analyzed incidence rates by race and sex. Hispanics were not found to have greater lifetime incidence rates than whites, with an incidence relative rate (IRR) of 0.86 that of whites (P=0.17). The age distribution among Hispanics was significantly different from non-Hispanic whites, with greater incidence rates for children ages 1-19 years (IRR=1.9, P=0.02) and adult ages 20-44 years (IRR=1.6, P=0.004). Blacks had lower lifetime incidence rates than non-Hispanic whites (IRR=0.75, P=0.04), Hispanics (IRR=0.64, P=0.007), and Asians (IRR=0.67, P=0.03). Asians did not differ from non-Hispanic whites in lifetime or age-specific incidence rates. These results indicate that while US Hispanics do not have greater lifetime incidence rates of acute promyelocytic leukemia, blacks have lower incidence rates of acute promyelocytic leukemia than Hispanics, non-Hispanic whites, and Asians. 相似文献
994.
C G Arruda J M Aldrighi L A Bortolotto I N Alecrin J A F Ramires 《Gynecological endocrinology》2006,22(10):557-563
BACKGROUND: Arterial hypertension and postmenopausal reduction of estrogen levels may be involved in modifications of the stiffness of large arteries. OBJECTIVES: To evaluate the pulse-wave velocity (PWV) and indirectly the arterial stiffness in hypertensive postmenopausal women submitted to hormone therapy with estradiol alone or combined with norethisterone acetate. SUBJECTS: Forty-five hypertensive postmenopausal women were double-blindly, randomly assigned to three arms of treatment: placebo (group I); estradiol 2 mg/day (group II); or estradiol 2 mg/day and norethisterone acetate 1 mg/day (group III). METHODS: Arterial stiffness was assessed from PWV measurements of the common carotid and femoral arteries (CF-PWV) and the common carotid and radial arteries (CR-PWV) obtained using the automatic Complior(R) device, taken at baseline and after 12 weeks of treatment. RESULTS: After the 12-week treatment, values of CF-PWV and CR-PWV were not significantly different (p = 0.910 and p = 0.736, respectively) among the groups. Systolic blood pressure showed a positive correlation with CF-PWV in groups II and III (p = 0.02 and p < 0.001, respectively). CONCLUSIONS: PWV and arterial stiffness in postmenopausal hypertensive women did not reduce over a 12-week treatment with estradiol alone compared with the same period of treatment with estradiol combined with norethisterone acetate. 相似文献
995.
Gábor Márk Somfai Kata Miháltz Eszter Tulassay János Rigó 《Hypertension in pregnancy》2006,25(1):11-20
OBJECTIVE: Visual symptoms are common in patients with preeclampsia, and are caused by various underlying pathological changes in the retina. Blurred vision may be one of these symptoms. We describe three cases in which the underlying retinal pathology of blurred vision was clarified using optical coherence tomography (OCT), a novel, non-invasive ophthalmic imaging technique that provides micrometer-scale resolution images of the human retina. METHODS: Three patients with preeclampsia complained of blurred vision postpartum. In all cases, ophthalmoscopy was performed at the bedside, followed by the assessment of best corrected visual acuity, slit-lamp biomicroscopy, fluorescein angiography (FLA), and OCT. In all cases, the presence of central visual defects was examined by an Amsler-grid. RESULTS: In one case, the symptoms were bilateral. In all affected eyes, the patients complained of a relative central scotoma. Ophthalmoscopy showed edema in the affected maculae, while OCT examination clarified a serous neurosensory detachment of the macula. In one case, a neurosensory detachment was also detected in the papillomacular region of a fellow eye with no symptoms. In two cases, FLA was performed, but only in one case could we detect late leakage and subretinal exudates. The serous detachments observed showed total resolution in all cases within 5 to 10 weeks, with restoration of visual acuity. CONCLUSION: In patients with preeclampsia, OCT may provide a useful method for the precise assessment of retinal changes, distinguishing retinal edema from serous neurosensory detachments. This finding may help to clarify the pathophysiological circulatory changes seen in preeclampsia. 相似文献
996.
Indices of surgical site infection risk and prediction of other adverse outcomes during hospitalization. 总被引:2,自引:0,他引:2
Miguel Delgado-Rodríguez Silvia Palma Antonio Gómez-Ortega Gabriel Martínez-Gallego Marcelino Medina-Cuadros 《Infection control and hospital epidemiology》2006,27(8):825-828
OBJECTIVE: To assess which adverse postsurgical outcomes are best predicted by the Study on the Efficacy of Nosocomial Infection Control (SENIC) index and the National Nosocomial Infection Surveillance system (NNIS) index. DESIGN: Prospective cohort study. SETTING: The service of general surgery at a tertiary care hospital. PATIENTS: A consecutive series of patients hospitalized for more than 1 day (n=2,989). RESULTS: The outcome best predicted by the SENIC and NNIS indices was assessed by estimating the area under the receiver operating characteristic (ROC) curve. The areas under the ROC curves for nosocomial infection and in-hospital death were higher for the NNIS index than they were for the SENIC index (P<.05). The NNIS index predicted in-hospital death better than it predicted surgical site infection (area under the ROC curve+/-SE, 0.836+/-0.022 vs 0.689+/-0.017; P=.001). CONCLUSIONS: The NNIS index is superior to the SENIC index for all adverse postsurgical outcomes. Its ability to predict in-hospital mortality is clearly better than its ability to predict surgical site infection. 相似文献
997.
998.
999.
1000.
BACKGROUND: Diffuse peritubular capillary (PTC) C4d deposition has been shown to be associated with relatively poor graft outcome. The significance of focal PTC C4d staining in the early post-transplant period is uncertain. METHODS: Sixty-five biopsies from 53 patients with acute rejection were graded (Banff '97 criteria), stained for C4d, monocytes and T cells, and divided into three groups according to PTC C4d: (i) focal C4d (F) (14 biopsies, 14 patients), (ii) diffuse C4d (D) (23 biopsies, 15 patients) and (iii) no C4d (N) (28 biopsies, 24 patients). The three groups were compared with respect to a variety of biopsy and clinical parameters including outcome. RESULTS: The incidence of transplant glomerulitis and glomerular monocyte infiltration were significantly greater in F (64% and 2.0+/-2.0) and D (57% and 3.4+/-2.0) than in N (11% and 0.2+/-0.2). A significantly higher proportion of F (93%) demonstrated acute cellular rejection (Banff '97 grade > or = 1A) than did D (35%). The F and D groups included significantly more females (50 and 67%, respectively) than did N (21%). The percentage of patients with a second or third transplant was higher in F (29%) and D (40%) than in N (8%) (P = 0.0589). The proportion of patients with glomerular filtration rate < 30 ml/min at 12, 24 and 48 months was higher in the D and F groups than in the N, and there was a statistically significant increasing trend in odds of this outcome occurring at 48 months across the three groups (D > F > N group) (P = 0.0416). CONCLUSION: The results suggest that the biopsy findings and clinical course in patients with focal PTC C4d staining are similar to those associated with diffuse C4d. 相似文献