全文获取类型
收费全文 | 28701篇 |
免费 | 2091篇 |
国内免费 | 51篇 |
专业分类
耳鼻咽喉 | 243篇 |
儿科学 | 917篇 |
妇产科学 | 638篇 |
基础医学 | 3865篇 |
口腔科学 | 320篇 |
临床医学 | 4357篇 |
内科学 | 4965篇 |
皮肤病学 | 625篇 |
神经病学 | 2821篇 |
特种医学 | 521篇 |
外科学 | 3223篇 |
综合类 | 312篇 |
一般理论 | 42篇 |
预防医学 | 3712篇 |
眼科学 | 422篇 |
药学 | 1742篇 |
中国医学 | 20篇 |
肿瘤学 | 2098篇 |
出版年
2024年 | 32篇 |
2023年 | 265篇 |
2022年 | 368篇 |
2021年 | 808篇 |
2020年 | 590篇 |
2019年 | 787篇 |
2018年 | 941篇 |
2017年 | 705篇 |
2016年 | 737篇 |
2015年 | 727篇 |
2014年 | 1080篇 |
2013年 | 1586篇 |
2012年 | 2378篇 |
2011年 | 2449篇 |
2010年 | 1299篇 |
2009年 | 1159篇 |
2008年 | 1939篇 |
2007年 | 2021篇 |
2006年 | 1849篇 |
2005年 | 1742篇 |
2004年 | 1571篇 |
2003年 | 1412篇 |
2002年 | 1368篇 |
2001年 | 225篇 |
2000年 | 223篇 |
1999年 | 246篇 |
1998年 | 257篇 |
1997年 | 201篇 |
1996年 | 172篇 |
1995年 | 137篇 |
1994年 | 132篇 |
1993年 | 128篇 |
1992年 | 144篇 |
1991年 | 108篇 |
1990年 | 105篇 |
1989年 | 80篇 |
1988年 | 77篇 |
1987年 | 71篇 |
1986年 | 79篇 |
1985年 | 66篇 |
1984年 | 72篇 |
1983年 | 52篇 |
1982年 | 52篇 |
1981年 | 49篇 |
1980年 | 29篇 |
1979年 | 52篇 |
1978年 | 29篇 |
1977年 | 33篇 |
1976年 | 30篇 |
1974年 | 27篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
Multiply Recurrent Trichilemmal Carcinoma With Perineural Invasion and Cytokeratin 17 Positivity 总被引:4,自引:0,他引:4
Julie E. Allee MD George Cotsarelis MD Benjamin Solky MD Jonathan L. Cook MD 《Dermatologic surgery》2003,29(8):886-889
BACKGROUND: Trichilemmal carcinoma is an uncommon cutaneous malignancy that is thought to be the malignant counterpart of the trichilemmoma. Despite histologic features such as pronounced cytologic atypia, trichilemmal carcinoma is often described as having a rather benign clinical course. Cases of tumor recurrence after therapy are uncommon, and tumor neurotropism has never been described. OBJECTIVE: A case of multiply recurrent trichilemmal carcinoma with perineural invasion is described. The outer root sheath differentiation of this neoplasm is confirmed with the use of novel antibodies directed toward cytokeratins that are expressed in this area of the hair follicle. METHODS: The trichilemmal carcinoma was excised using the Mohs surgical technique. Tissue obtained during the extirpation of the tumor was subjected to immunohistochemical staining for cytokeratin 15, cytokeratin 17, and c-erb-B2. RESULTS: Tumor neurotropism was noted. The trichilemmal carcinoma demonstrated abundant cytoplasmic staining for cytokeratin 17 and c-erb-B2. CONCLUSIONS: In distinction to previous reports, this case reveals that trichilemmal carcinoma can demonstrate significant biological aggression, as reflected by tumor neurotropism and by failure to respond to multiple surgical excisions. The purported outer root sheath differentiation of this neoplasm is confirmed with the use of novel immunohistochemical staining. This immunohistochemical staining may be useful in differentiating trichilemmal carcinoma from other clear cell neoplasms. 相似文献
92.
93.
94.
95.
Larry Burd Jacob Kerbeshian Julie L. Meredith 《Journal of developmental and physical disabilities》1997,9(3):255-263
This paper reviews the association of Huntington's Disease (HD) and tic disorder or Tourette Syndrome (TS) We also present the results of a follow-up study of a male with childhood-onset TS and adult-onset HD who died at 45 years of age. The developmental course and results of neuropathologic and molecular studies of this patient are reported. This is the first case of childhood onset of TS with adult onset of HD reported who has come to autopsy. A developmental model for childhood and adult neuropsychiatric disorders is presented. 相似文献
96.
Eta S Berner Julie J McGowan J Michael Hardin S Andrew Spooner William V Raszka Roger L Berkow 《Academic medicine》2002,77(6):547-551
PURPOSE: To develop and evaluate a model for assessing information retrieval and application skills, and to compare the performances on the assessment exercises of students who were and were not instructed in these skills. METHOD: The authors developed a set of four examination stations, each with multiple subtasks, and administered the exams to students at two medical schools. Students at one school had intensive instruction in literature searching and filtering skills for information quality (instructed group), and those at the other school had minimal instruction in these areas (uninstructed group). The stations addressed pediatrics content and the skills of searching Medline and the World Wide Web, evaluating research articles, evaluating the accuracy of information from the Web, and using the information to make recommendations to patients. The authors determined the psychometric characteristics of the stations and compared the performances of the two groups of students. RESULTS: Students in the instructed group performed significantly better and with less variability than the uninstructed group on four tasks and no differently on seven tasks. There was no task on which the uninstructed group performed significantly better than the instructed group. CONCLUSION: The prototype stations showed predictable differences across curricula, indicating that they have promise as assessment tools for the essential skills of information retrieval and application. 相似文献
97.
Feng-Chun Tsai Daniel Marelli Jessica Bresson David Gjertson Reza Kermani Abbas Ardehali Fardad Esmailian Michele Hamilton Gregg C Fonarow Jaime Moriguchi Mark Plunkett Antoine Hage Julie Tran Jon A Kobashigawa Hillel Laks 《American journal of transplantation》2002,2(6):539-545
Older age, prior transplantation, pulmonary hypertension, and mechanical support are commonly seen in current potential cardiac transplant recipients. Transplants in 436 consecutive adult patients from 1994 to 1999 were reviewed. There were 251 using standard donors in 243 patients (age range 18-69 years). To emphasize recipient risk, 185 patients who received a nonstandard donor were excluded from analysis. The indications for transplant were ischemic heart disease (n = 123, 47%), dilated cardiomyopathy (n = 82, 32%), and others (n=56, 21%). One hundred and forty-nine (57%) recipients were listed as status I; 5 and 6% were supported with an intra-aortic balloon and an assist device, respectively. The 30-d survival and survival to discharge were 94.7 and 92.7%, respectively; 1-year survival was 89.1%. Causes of early death were graft failure (n = 6), infection (n = 4), stroke (n = 4), multiorgan failure (n = 3) and rejection (n = 2). Predictors were balloon pump use alone (OR= 11.4, p =0.002), pulmonary vascular resistance > 4 Wood units (OR = 5.7, p = 0.007), pretransplant creatinine > 2.0 mg/dL (OR = 6.9, p = 0.004) and female donor (OR = 8.3, p = 0.002). Recipient age and previous surgery did not affect short-term survival. Heart transplantation in the current era consistently offers excellent early and 1-year survival for well-selected recipients receiving standard donors. Early mortality tends to reflect graft failure while hospital mortality may be more indicative of recipient selection. 相似文献
98.
Julie D Rippeth Robert K Heaton Catherine L Carey Thomas D Marcotte David J Moore Raul Gonzalez Tanya Wolfson Igor Grant 《Journal of the International Neuropsychological Society》2004,10(1):1-14
Both HIV infection and methamphetamine dependence can be associated with brain dysfunction. Little is known, however, about the cognitive effects of concurrent HIV infection and methamphetamine dependence. The present study included 200 participants in 4 groups: HIV infected/methamphetamine dependent (HIV+/METH+), HIV negative/methamphetamine dependent (HIV-/METH+), HIV infected/methamphetamine nondependent (HIV+/METH-), and HIV negative/methamphetamine nondependent (HIV-/METH-). Study groups were comparable for age, education, and ethnicity, although the HIV-/METH- group had significantly more females. A comprehensive, demographically corrected neuropsychological battery was administered yielding a global performance score and scores for seven neurobehavioral domains. Rates of neuropsychological impairment were determined by cutoff scores derived from performances of a separate control group and validated with larger samples of HIV+ and HIV- participants from an independent cohort. Rates of global neuropsychological impairment were higher in the HIV+/METH+ (58%), HIV-/METH+ (40%) and HIV+/METH- (38%) groups compared to the HIV-/METH- (18%) group. Nonparametric analyses revealed a significant monotonic trend for global cognitive status across groups, with least impairment in the control group and highest prevalence of impairment in the group with concurrent HIV infection and methamphetamine dependence. The results indicate that HIV infection and methamphetamine dependence are each associated with neuropsychological deficits, and suggest that these factors in combination are associated with additive deleterious cognitive effects. This additivity may reflect common pathways to neural injury involving both cytotoxic and apoptotic mechanisms. 相似文献
99.
100.