全文获取类型
收费全文 | 20536篇 |
免费 | 1406篇 |
国内免费 | 120篇 |
专业分类
耳鼻咽喉 | 283篇 |
儿科学 | 480篇 |
妇产科学 | 371篇 |
基础医学 | 2732篇 |
口腔科学 | 475篇 |
临床医学 | 1938篇 |
内科学 | 3780篇 |
皮肤病学 | 216篇 |
神经病学 | 2434篇 |
特种医学 | 719篇 |
外国民族医学 | 1篇 |
外科学 | 2604篇 |
综合类 | 247篇 |
一般理论 | 14篇 |
预防医学 | 1989篇 |
眼科学 | 714篇 |
药学 | 1747篇 |
中国医学 | 47篇 |
肿瘤学 | 1271篇 |
出版年
2023年 | 81篇 |
2022年 | 150篇 |
2021年 | 341篇 |
2020年 | 198篇 |
2019年 | 307篇 |
2018年 | 406篇 |
2017年 | 324篇 |
2016年 | 314篇 |
2015年 | 370篇 |
2014年 | 576篇 |
2013年 | 893篇 |
2012年 | 1298篇 |
2011年 | 1372篇 |
2010年 | 732篇 |
2009年 | 619篇 |
2008年 | 1271篇 |
2007年 | 1386篇 |
2006年 | 1358篇 |
2005年 | 1405篇 |
2004年 | 1364篇 |
2003年 | 1266篇 |
2002年 | 1256篇 |
2001年 | 234篇 |
2000年 | 210篇 |
1999年 | 259篇 |
1998年 | 273篇 |
1997年 | 260篇 |
1996年 | 207篇 |
1995年 | 236篇 |
1994年 | 150篇 |
1993年 | 187篇 |
1992年 | 164篇 |
1991年 | 143篇 |
1990年 | 145篇 |
1989年 | 141篇 |
1988年 | 117篇 |
1987年 | 137篇 |
1986年 | 126篇 |
1985年 | 144篇 |
1984年 | 142篇 |
1983年 | 133篇 |
1982年 | 174篇 |
1981年 | 192篇 |
1980年 | 162篇 |
1979年 | 103篇 |
1978年 | 102篇 |
1977年 | 121篇 |
1976年 | 101篇 |
1975年 | 64篇 |
1974年 | 44篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
Nicholas J. Okon DO ; Daniel V. Rodriguez MD ; Dennis W. Dietrich MD ; Carrie S. Oser MPH ; Lynda L. Blades MPH ; Anne M. Burnett RN MN CPHQ ; Joseph A. Russell NREMT-P ; Martha J. Allen RN ; Linda Chasson MSA ; Steven D. Helgerson MD MPH ; Dorothy Gohdes MD ; Todd S. Harwell MPH 《The Journal of rural health》2006,22(3):237-241
CONTEXT: Rapid diagnosis and treatment of ischemic stroke can lead to improved patient outcomes. Hospitals in rural and frontier counties, however, face unique challenges in providing diagnostic and treatment services for acute stroke. PURPOSE: The aim of this study was to assess the availability of key diagnostic technology and programs for acute stroke evaluation and treatment in Montana and northern Wyoming. METHODS: In 2004, hospital medical directors or their designees were mailed a survey about the availability of diagnostic technology, programs, and personnel for acute stroke care. FINDINGS: Fifty-eight of 67 (87%) hospitals responded to the survey. Seventy-nine percent (46/58) of responding hospitals were located in frontier counties, with an average bed size of 18 (11 SD). Of the hospitals in frontier counties, 44% reported emergency medical services prehospital stroke identification programs, 39% had 24-hour computed tomography capability, 44% had an emergency department stroke protocol, and 61% had a recombinant tissue plasminogen activator protocol. Thirty percent of hospitals in frontier counties reported that they met 6-10 of the criteria established by the Brain Attack Coalition to improve acute stroke care compared to 67% of hospitals in the nonfrontier counties. CONCLUSION: A stroke network model could enhance care and improve outcomes for stroke victims in frontier counties. 相似文献
993.
Janel Hanmer William F Lawrence John P Anderson Robert M Kaplan Dennis G Fryback 《Medical decision making》2006,26(4):391-400
BACKGROUND: Despite widespread use of generic health-related quality-of-life (HRQoL) scores, few have publicly published nationally representative US values. PURPOSE: To create current nationally representative values for 7 of the most common HRQoL scores, stratified by age and sex. METHODS: The authors used data from the 2001 Medical Expenditures Panel Survey (MEPS) and the 2001 National Health Interview Survey (NHIS), nationally representative surveys of the US noninstitutionalized civilian population: The MEPS was used to calculate 6 HRQoL scores: categorical self-rated health, EuroQoL-5D with US scoring, EuroQoL-5D with UK scoring, EuroQol Visual Analog Scale, mental and physical component summaries from the SF-12, and the SF-6D. The authors estimated Quality of Well-being scale scores from the NHIS. RESULTS: They included 22,523 subjects from MEPS 2001 and 32,472 subjects from NHIS 2001. Most age and sex categories had instrument completion rates above 85%. Females reported lower scores than males across all ages and instruments. In general, those in older age groups reported lower scores than younger age groups, with the exception of the mental component summary from the SF-12. CONCLUSION: This is one of the first sets of publicly available, nationally representative US values for any standardized HRQoL measure. These values are important for use in both generalized comparisons of health status and in cost-effectiveness analyses. 相似文献
994.
Mark J Gallardo Daniel A Johnson Juan Gaviria Loan Nguyen Robert Melendez Dallas A Connor Dennis A Conrad 《Journal of AAPOS》2005,9(3):285-287
Herpes simplex virus (HSV) infection can be devastating in the neonate. The disease most commonly presents as 1 of 3 clinical manifestations: disseminated visceral infection (with and without central nervous system involvement), isolated meningoencephalitis, and infection limited to the skin, eyes, and/or mucous membranes (SEM). Exposure leading to neonatal infection typically occurs as peripartum vertical transmission, most typically by direct contact with urogenital lesions or infected genital secretions, or as an ascending infection exploiting disrupted chorioamniotic membranes. We present a novel case of a newborn girl who developed HSV-2 keratoconjunctivitis despite being delivered via an elective, uncomplicated, repeat cesarean over intact chorioamniotic membranes in the absence of active clinical maternal HSV infection and despite having a negative medical history of previous orolabial or genital herpetic infection. 相似文献
995.
Phosphatidylinositol 3-kinase inhibition by LY294002 radiosensitizes human cervical cancer cell lines. 总被引:2,自引:0,他引:2
Christopher M Lee Christa B Fuhrman Vicente Planelles Morgan R Peltier David K Gaffney Andrew P Soisson Mark K Dodson H Dennis Tolley Christopher L Green Karen A Zempolich 《Clinical cancer research》2006,12(1):250-256
PURPOSE: The phosphatidylinositol 3-kinase (PI3K) catalytic subunit is amplified in cervical cancers, implicating PI3K in cervical carcinogenesis. We evaluated the radiosensitizing effect of PI3K inhibition by LY294002 on clonogenic survival, growth characteristics, and gene expression in cervical cancer cell lines (HeLa and CaSki). EXPERIMENTAL DESIGN: Cervical cancer cells were treated separately and concurrently with the PI3K inhibitor LY294002 (10 micromol/L) and radiation (2 Gy) with serial analysis of cell count, apoptosis, and flow cytometry. PI3K inhibition was assessed by protein analysis of phosphorylated Akt. Clonogenic assays were done with varying doses of radiation and LY294002 and varied time points of administration of LY294002 proximate to the radiation dose. Surviving fractions and dose modification factors (DMF) were calculated. Each experiment was done in triplicate and analyzed using ANOVA regression analysis and Dunnett's t Test. Microarray gene expression analysis was done on the HeLa cell line. RESULTS: PI3K inhibition with LY294002 alone did not decrease cell survival. However, treatment with LY294002 significantly radiosensitized HeLa and CaSki cell lines with DMFs (1 log cell kill) of 1.95 and 1.37, respectively. Compared with post-irradiation, pretreatment produced more radiosensitization (P < 0.0001). DMFs were 2.2, 2.0, 2.0, and 1.2 for LY294002 added at 6, 2, and 0.5 hours before irradiation and 6 hours after irradiation, respectively. LY294002 pretreatment in irradiated HeLa cells led to altered gene expression. CONCLUSIONS: Although LY294002 alone did not produce cytotoxic effects, PI3K inhibition with LY294002 produced significant radiosensitization, showed significant time-dependent effects, increased apoptosis, and altered gene expression. These findings support future investigation of PI3K inhibitors in combination with radiation therapy for carcinoma of the cervix. 相似文献
996.
Renate Kirschner-Schwabe Claudio Lottaz J?rn T?dling Peter Rhein Leonid Karawajew Cornelia Eckert Arend von Stackelberg Ute Ungethüm Dennis Kostka Andreas E Kulozik Wolf-Dieter Ludwig Günter Henze Rainer Spang Christian Hagemeier Karl Seeger 《Clinical cancer research》2006,12(15):4553-4561
PURPOSE: In childhood acute lymphoblastic leukemia (ALL), approximately 25% of patients suffer from relapse. In recurrent disease, despite intensified therapy, overall cure rates of 40% remain unsatisfactory and survival rates are particularly poor in certain subgroups. The probability of long-term survival after relapse is predicted from well-established prognostic factors (i.e., time and site of relapse, immunophenotype, and minimal residual disease). However, the underlying biological determinants of these prognostic factors remain poorly understood. EXPERIMENTAL DESIGN: Aiming at identifying molecular pathways associated with these clinically well-defined prognostic factors, we did gene expression profiling on 60 prospectively collected samples of first relapse patients enrolled on the relapse trial ALL-REZ BFM 2002 of the Berlin-Frankfurt-Münster study group. RESULTS: We show here that patients with very early relapse of ALL are characterized by a distinctive gene expression pattern. We identified a set of 83 genes differentially expressed in very early relapsed ALL compared with late relapsed disease. The vast majority of genes were up-regulated and many were late cell cycle genes with a function in mitosis. In addition, samples from patients with very early relapse showed a significant increase in the percentage of S and G(2)-M phase cells and this correlated well with the expression level of cell cycle genes. CONCLUSIONS: Very early relapse of ALL is characterized by an increased proliferative capacity of leukemic blasts and up-regulated mitotic genes. The latter suggests that novel drugs, targeting late cell cycle proteins, might be beneficial for these patients that typically face a dismal prognosis. 相似文献
997.
998.
999.
1000.
Charlotta Enerb?ck Dale A Porter Pankaj Seth Dennis Sgroi Justine Gaudet Stanislawa Weremowicz Cynthia C Morton Stuart Schnitt Robert L Pitts Jason Stampl Kerry Barnhart Kornelia Polyak 《Cancer research》2002,62(1):43-47
We determined, by serial analysis of gene expression (SAGE) analysis of normal and DCIS (ductal carcinoma in situ) mammary epithelial cells, that psoriasin and several other genes implicated in psoriasis are aberrantly expressed in high-grade, comedo DCIS. Real-time PCR, mRNA in situ hybridization, and immunohistochemical analysis of breast carcinomas confirmed that psoriasin is frequently overexpressed in estrogen receptor-negative tumors. To gain insight into regulatory pathways that control psoriasin expression, we developed polyclonal and monoclonal antibodies and investigated mechanisms that may account for elevated levels of psoriasin in DCIS. Here, we report that loss of attachment to extracellular matrix, growth factor deprivation, and confluent conditions dramatically up-regulate psoriasin expression in MCF10A mammary epithelial cells. All of these conditions are characteristic of high-grade DCIS and psoriatic skin lesions; therefore, the same mechanisms may be responsible for increased expression of psoriasin in vitro and in vivo. 相似文献