全文获取类型
收费全文 | 5021篇 |
免费 | 342篇 |
国内免费 | 24篇 |
专业分类
耳鼻咽喉 | 23篇 |
儿科学 | 79篇 |
妇产科学 | 147篇 |
基础医学 | 661篇 |
口腔科学 | 118篇 |
临床医学 | 560篇 |
内科学 | 1077篇 |
皮肤病学 | 73篇 |
神经病学 | 363篇 |
特种医学 | 336篇 |
外科学 | 731篇 |
综合类 | 44篇 |
一般理论 | 3篇 |
预防医学 | 207篇 |
眼科学 | 76篇 |
药学 | 413篇 |
中国医学 | 2篇 |
肿瘤学 | 474篇 |
出版年
2023年 | 67篇 |
2022年 | 93篇 |
2021年 | 231篇 |
2020年 | 132篇 |
2019年 | 160篇 |
2018年 | 185篇 |
2017年 | 134篇 |
2016年 | 146篇 |
2015年 | 162篇 |
2014年 | 203篇 |
2013年 | 235篇 |
2012年 | 374篇 |
2011年 | 359篇 |
2010年 | 205篇 |
2009年 | 159篇 |
2008年 | 221篇 |
2007年 | 257篇 |
2006年 | 215篇 |
2005年 | 205篇 |
2004年 | 176篇 |
2003年 | 188篇 |
2002年 | 192篇 |
2001年 | 111篇 |
2000年 | 105篇 |
1999年 | 78篇 |
1998年 | 58篇 |
1997年 | 30篇 |
1996年 | 29篇 |
1995年 | 15篇 |
1994年 | 16篇 |
1992年 | 42篇 |
1991年 | 47篇 |
1990年 | 37篇 |
1989年 | 35篇 |
1988年 | 40篇 |
1987年 | 31篇 |
1986年 | 29篇 |
1985年 | 27篇 |
1984年 | 21篇 |
1983年 | 15篇 |
1981年 | 15篇 |
1979年 | 21篇 |
1978年 | 14篇 |
1977年 | 18篇 |
1975年 | 17篇 |
1973年 | 15篇 |
1972年 | 31篇 |
1970年 | 13篇 |
1969年 | 19篇 |
1968年 | 19篇 |
排序方式: 共有5387条查询结果,搜索用时 15 毫秒
61.
OBJECTIVES--The debate in Massachusetts over the repeal of the first state-based "pay or play" universal health plan is discussed using data from a survey of 1066 Massachusetts households. The survey attempted to measure the problems of the uninsured, to estimate the likelihood that they would buy insurance if offered, and to calculate the proportion of the uninsured who would be covered under an employer mandate. DESIGN--A survey conducted in person and by telephone in 1066 households, with an oversample of uninsured households, using stratification, clustering, disproportionate sampling, and poststatistical weighting. PARTICIPANTS--Adults aged 18 years and older who were knowledgeable about the insurance status of persons in their household. MAIN OUTCOME MEASURES--Insurance status, employment status, access to and use of health services, and willingness to purchase health insurance. RESULTS--First, the present system of hospital-based uncompensated care in Massachusetts is inadequate by itself to meet the needs of uninsured residents. Uninsured persons are less likely than insured ones to seek medical care for chronic health problems and serious symptoms requiring evaluation. Second, 83% of uninsured families and 24% of uninsured individual respondents would purchase one of several insurance options with 30% of the cost subsidized. Last, the employer mandate provisions of the legislation would cover 43% of the uninsured in Massachusetts. CONCLUSION--In the current economic climate, the political viability of the universal health care plan and similar national initiatives is uncertain given the intractable conflict between perceptions of the financial stability of small businesses that do not offer insurance and the health care needs of uninsured individuals. 相似文献
62.
Summary In 11 mongrel dogs both kidneys have been subjected to a 2 h ischaemic period. One kidney was cooled by perfusing the renal artery at 4°C while the contralateral normothermic kidney was clamped for 2 h. Studying the renal blood flow using the Xenon wash out technique, sequential renal scanning and angiography, marked differences between hypo- and normothermic ischaemia kidneys were observed. One or two hours following hypothermic perfusion a marked decrease of blood flow in the first compartment and vasoconstriction was evident, while within this period following normothermic ischaemia an enhanced renal blood flow was observed. After 24 h renal blood flow and renal function tested by 131I-Hippuran clearance returned to normal values. Angiographic studies corresponded to the preoperative findings. In contrast, normothermic ischaemia kidneys showed a decreased renal blood flow, impairment of kidney function in isotope studies and pathological angiographic changes.Supported by Deutsche Forschungsgemeinschaft 相似文献
63.
Prognostic impact of ANX7-GTPase in metastatic and HER2-negative breast cancer patients. 总被引:4,自引:0,他引:4
Meera Srivastava Lukas Bubendorf Mark Raffeld Christoph Bucher Jochen Torhorst Guido Sauter Cara Olsen Olli P Kallioniemi Ofer Eidelman Harvey B Pollard 《Clinical cancer research》2004,10(7):2344-2350
PURPOSE: ANX7-GTPase located on chromosome 10q21 is significantly altered and associated with hormone-refractory metastatic prostate cancers. Therefore, we investigated whether levels of ANX7 correlate with breast cancer progression and survival EXPERIMENTAL DESIGN: A diagnostic tumor tissue microarray containing 525 human breast tissue specimens at different stages of the disease was assayed for ANX7 using immunocytochemical methods with ANX7 monoclonal antibody. A separate prognostic tumor tissue microarray containing 553 human breast tissue specimens annotated with clinicopathological parameters was assayed for ANX7, HER2, estrogen receptor, progesterone receptor, and p53 protein. RESULTS: We report here for the first time that the expression of ANX7-GTPase is significantly enhanced and associated with the presence of metastatic disease (P < 0.0001) in the 525 human breast tissue specimens analyzed. Furthermore, using a separate 553 case retrospective prognostic tumor tissue microarray, we found that increased ANX7 expression is also significantly associated with poor overall patient survival (P < 0.014). This is particularly true when restricted to patients in whom the BRE clinical grade is 2 (P < 0.001) or for whom there is a lack of HER2 expression (P < 0.002). Finally, Cox regression analysis shows that as the expression of ANX7 rises, the probability of survival decreases by more than 10-fold for those patients with HER2-negative tumors. These latter patients represented 66% of the population affected with breast cancer in this study. CONCLUSIONS: High levels of ANX7 in tumor correlate strongly with poor survival of HER2-negative patients and the most aggressive forms of breast cancer. This is the first study to demonstrate that ANX7 antibody has the potential for development into an in vivo diagnostic and therapeutic tool. This simple and reliable immunohistochemical assay may therefore become an important biomarker for metastatic breast cancer diagnosis and management of HER2-negative breast tumor patients. 相似文献
64.
65.
66.
Jean-Blaise Wasserfallen Alexandre Berger Philippe Eckert Jean-Christophe Stauffer Jürg Schlaepfer Dominique Gillis Jacques Cornuz Marie-Denise Schaller Lukas Kappenberger Bertrand Yersin 《International journal for quality in health care》2004,16(5):383-389
OBJECTIVE: To assess the impact of introducing clinical practice guidelines on acute coronary syndrome without persistent ST segment elevation (ACS) on patient initial assessment. DESIGN: Prospective before-after evaluation over a 3-month period. SETTING: The emergency ward of a tertiary teaching hospital. PATIENTS: All consecutive patients with ACS evaluated in the emergency ward over the two 3-month periods. INTERVENTION: Implementation of the practice guidelines, and the addition of a cardiology consultant to the emergency team. MAIN OUTCOME MEASURES: Diagnosis, electrocardiogram interpretation, and risk stratification after the initial evaluation. RESULTS: The clinical characteristics of the 328 and 364 patients evaluated in the emergency ward for suspicion of ACS before and after guideline implementation were similar. Significantly more patients were classified as suffering from atypical chest pain (39.6% versus 47.0%; P = 0.006) after guideline implementation. Guidelines availability was associated with significantly more formal diagnoses (79.9% versus 92.9%; P < 0.0001) and risk stratification (53.7% versus 65.4%, P < 0.0001) at the end of initial assessment. CONCLUSION: Guidelines implementation, along with availability of a cardiology consultant in the emergency room had a positive impact on initial assessment of patients evaluated for suspicion of ACS. It led to increased confidence in diagnosis and stratification by risk, which are the first steps in initiating effective treatment for this common condition. 相似文献
67.
Cowan RL Frederick BB Rainey M Levin JM Maas LC Bang J Hennen J Lukas SE Renshaw PF 《Psychiatry research》2000,100(3):129-138
Studies using a variety of investigative methods, including functional brain imaging and electroencephalography (EEG), have suggested that changes in central nervous system (CNS) dopamine function result in altered visual system processing. The discovery of abnormal retinal blue cone, but not red cone, electroretinogram in association with cocaine withdrawal and Parkinson's disease suggests that visual system response to blue light might be a marker for CNS dopamine tone. As there are numerous sex-related differences in central nervous system dopamine function, we predicted that blue and red light stimulation would produce sex-specific patterns of response in primary visual cortex when studied using the blood oxygen level dependent (BOLD) functional magnetic resonance imaging (fMRI) technique. We analyzed the BOLD response to red and blue light in male and female human volunteers (N=20). Red and blue light responses in primary visual cortex (V1) to stepped intensities of red and blue light were compared by sex for threshold to detectable BOLD signal increase and for stimulus intensity vs. BOLD signal response. Near threshold, males and females showed similar BOLD signal change to red light, but males showed a threefold greater increase (0.52%) to blue light stimulation when compared to females (0.14%). Log-linear regression modeling revealed that the slope coefficients for the red light stimulus intensity vs. signal change curve were not significantly different for males and females (z=0.995, P=0.320), whereas the slope coefficients for the blue light stimulus intensity vs. signal change curve were significantly larger in males (z=2.251, P=0.024). These findings support a sex and color-dependent differential pattern of primary visual cortical response to photic stimulation and suggest a method for assessing the influence of specific dopamine agonist/antagonist medications on visual function. 相似文献
68.
Stefano Pini Valéria de Queiroz Daniel Pagnin Lukas Pezawas Jules Angst Giovanni B Cassano Hans-Ulrich Wittchen 《European neuropsychopharmacology》2005,15(4):425-434
A literature search, supplemented by an expert survey and selected reanalyses of existing data from epidemiological studies was performed to determine the prevalence and associated burden of bipolar I and II disorder in EU countries. Only studies using established diagnostic instruments based on DSM-III-R or DSM-IV, or ICD-10 criteria were considered. Fourteen studies from a total of 10 countries were identified. The majority of studies reported 12-month estimates of approximately 1% (range 0.5-1.1%), with little evidence of a gender difference. The cumulative lifetime incidence (two prospective-longitudinal studies) is slightly higher (1.5-2%); and when the wider range of bipolar spectrum disorders is considered estimates increased to approximately 6%. Few studies have reported separate estimates for bipolar I and II disorders. Age of first onset of bipolar disorder is most frequently reported in late adolescence and early adulthood. A high degree of concurrent and sequential comorbidity with other mental disorders and physical illnesses is common. Most studies suggest equally high or even higher levels of impairments and disabilities of bipolar disorders as compared to major depression and schizophrenia. Few data are available on treatment and health care utilization. 相似文献
69.
Interleukin-1 and interleukin-6 gene polymorphisms and the risk of breast cancer in caucasian women. 总被引:7,自引:0,他引:7
Lukas A Hefler Christoph Grimm Tilmann Lantzsch Dieter Lampe Sepp Leodolter Heinz Koelbl Georg Heinze Alexander Reinthaller Dan Tong-Cacsire Clemens Tempfer Robert Zeillinger 《Clinical cancer research》2005,11(16):5718-5721
PURPOSE: Genetic polymorphisms of cytokine-encoding genes are known to predispose to malignant disease. Interleukin (IL)-1 and IL-6 are crucially involved in breast carcinogenesis. Whether polymorphisms of the genes encoding IL-1 (IL1) and IL-6 (IL6) also influence breast cancer risk is unknown. EXPERIMENTAL DESIGN: In the present case-control study, we ascertained three polymorphisms of the IL1 gene cluster [-889 C/T polymorphism of the IL1alpha gene (IL1A), -511 C/T polymorphism of the IL1beta promoter (IL1B promoter), a polymorphism of IL1beta exon 5 (IL1B exon 5)], an 86-bp repeat in intron 2 of the IL1 receptor antagonist gene (IL1RN), and the -174 G/C polymorphism of the IL6 gene (IL6) in 269 patients with breast cancer and 227 healthy controls using PCR and pyrosequencing. RESULTS: Polymorphisms within the IL1 gene cluster and the respective haplotypes were not associated with the presence and the phenotype of breast cancer. The IL6 polymorphism was significantly associated with breast cancer. Odds ratios for women with one or two high-risk alleles versus women homozygous for the low-risk allele were 1.5 (95% confidence interval, 1.04-2.3; P = 0.04) and 2.0 (95% confidence interval, 1.1-3.6; P = 0.02), respectively. No association was ascertained between presence of the IL6 polymorphism and various clinicopathologic variables. CONCLUSIONS: Although polymorphisms within the IL1 gene cluster do not seem to influence breast cancer risk or phenotype, presence of the -174C IL6 allele increases the risk of breast cancer in Caucasian women in a dose-dependent fashion. 相似文献
70.