全文获取类型
收费全文 | 37540篇 |
免费 | 3126篇 |
国内免费 | 155篇 |
专业分类
耳鼻咽喉 | 645篇 |
儿科学 | 918篇 |
妇产科学 | 675篇 |
基础医学 | 4617篇 |
口腔科学 | 981篇 |
临床医学 | 3458篇 |
内科学 | 8599篇 |
皮肤病学 | 380篇 |
神经病学 | 3378篇 |
特种医学 | 1225篇 |
外科学 | 6257篇 |
综合类 | 741篇 |
一般理论 | 24篇 |
预防医学 | 2895篇 |
眼科学 | 989篇 |
药学 | 2433篇 |
中国医学 | 82篇 |
肿瘤学 | 2524篇 |
出版年
2023年 | 148篇 |
2022年 | 252篇 |
2021年 | 711篇 |
2020年 | 402篇 |
2019年 | 659篇 |
2018年 | 782篇 |
2017年 | 632篇 |
2016年 | 631篇 |
2015年 | 717篇 |
2014年 | 1149篇 |
2013年 | 1614篇 |
2012年 | 2416篇 |
2011年 | 2454篇 |
2010年 | 1355篇 |
2009年 | 1314篇 |
2008年 | 2273篇 |
2007年 | 2409篇 |
2006年 | 2528篇 |
2005年 | 2496篇 |
2004年 | 2332篇 |
2003年 | 2347篇 |
2002年 | 2187篇 |
2001年 | 438篇 |
2000年 | 431篇 |
1999年 | 502篇 |
1998年 | 532篇 |
1997年 | 409篇 |
1996年 | 382篇 |
1995年 | 327篇 |
1994年 | 297篇 |
1993年 | 249篇 |
1992年 | 339篇 |
1991年 | 302篇 |
1990年 | 285篇 |
1989年 | 263篇 |
1988年 | 257篇 |
1987年 | 233篇 |
1986年 | 232篇 |
1985年 | 222篇 |
1984年 | 247篇 |
1983年 | 207篇 |
1982年 | 230篇 |
1981年 | 222篇 |
1980年 | 175篇 |
1979年 | 172篇 |
1978年 | 176篇 |
1977年 | 158篇 |
1975年 | 130篇 |
1974年 | 149篇 |
1973年 | 138篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
The medical hazards of salmon farming can be grouped into thoserelated to marine safety, fish husbandry, fish-farm diving anddisease treatments. The hostile water environment requires thermalprotection and personal buoyancy aids as workers frequentlyfall in the water from boats or cages. Feedstuffs may generaterespirable dust and attract rats, creating a risk of leptospirosis.Musculo-skeletal injuries are common from lifting nets. Fish-farmdiving has particular risks which can be minimized. Organophosphorouspesticides are used to treat sea lice and employees requirehealth surveillance. Fish immunization is required to reducethe incidence of Aeromonas salmonitica. Needlestick injurieswhen using oil-based vaccines are a serious hazard to employees.The occupational health problems of salmon farming are predictableand preventable with primary safety measures. This new industryis safer than land-based agriculture on current evidence. 相似文献
42.
43.
44.
P S Douglas K F Moos W S Hislop 《The British journal of oral & maxillofacial surgery》1992,30(6):382-386
Five female patients with Klippel-Feil syndrome (KFS) are presented with abnormal bony masses in the mandibular ramus region. The features of KFS are described with assessment and treatment of the five patients. Although congenital duplication of mandibular rami in KFS has been previously documented, we believe this is the first series of patients with this deformity. 相似文献
45.
OBJECTIVES: To investigate variation among neonatal intensive care units (NICUs) in prevalence and management of thrombocytopenia in infants <1500 g. STUDY DESIGN: In total 1283 infants &<1500 g admitted to six NICUs over 21 months were prospectively analyzed. Illness severity was measured by the Score for Neonatal Acute Physiology (SNAP). Platelet counts in the first 12 hours after birth and on day 3 of life were abstracted from the infants' medical records. Thrombocytopenia was determined from the lowest platelet count in each of these time periods. RESULTS: There was variability in rates of thrombocytopenia among NICUs, even after controlling for risk factors (e.g., SNAP, small for gestational (SGA) age and maternal hypertension). One site had a high prevalence of thrombocytopenia, but the lowest percentage of infants with thrombocytopenia who received platelet transfusions. After controlling for SNAP, GA, SGA, Apgar score and incidence of thrombocytopenia, the odds of receiving platelets at this site, relative to the site with the highest transfusion rate, was 0.10 (95% CI 0.02 to 0.43). CONCLUSIONS: This multicenter study finds a 10-fold variation among NICU in the administration of platelets to their thrombocytopenic infants that cannot be explained by presence of thrombocytopenia or illness severity. 相似文献
46.
Robert C. Knowlton MD Nicholas D. Lawn FRACP James M. Mountz MD PhD Ojha Buddhiwardhan MD Suzanne Miller RN BSN Jorge G. Burneo MD Ruben I. Kuzniecky MD 《Journal of neuroimaging》2004,14(4):324-330
PURPOSE: To examine the application of statistical parametric mapping (SPM) to analyze ictal single-photon emission computed tomography (SPECT) scans in surgical candidates with extratemporal lobe epilepsy. METHODS: The authors selected patients who underwent successful ictal SPECT acquisition in the process of surgical treatment of intractable partial epilepsy. Thirteen patients were identified who met inclusion criteria for confident seizure localization from either intracranial electroencephalogram recordings or epilepsy surgery outcome. In these cases, ictal scans were registered to an in-house-developed normal SPECT atlas composed of 14 spatially normalized brains of normal subjects. SPM96 was used to test on a voxel-by-voxel basis for statistically significant increases in blood flow associated with each patient's ictal scan. The results were then mapped back onto the patient's magnetic resonance image (MRI) for final interpretation. Statistical parametric mapping (SPM) analysis of ictal SPECT scans was compared to both conventional visual interpretation and the analysis of subtraction ictal SPECT co-registered to MRI (SISCOM). RESULTS: Ten of 13 patient scans showed localizing focal ictal increases in regional cerebral blood flow, all of which were concordant with ultimate epilepsy localization. Of the 3 cases not localized with SPM, 1 was localized by conventional visual interpretation and another, not localized by visual interpretation, was correctly localized with SISCOM. Two cases not localized by SISCOM were localized by both visual and SPM analysis. CONCLUSIONS: This work provides supportive evidence for proof of principle that SPM can be used to provide objective, accurate analysis of ictal SPECT scans in patients with extratemporal lobe epilepsy. 相似文献
47.
Simone Shurland Min Zhan Douglas D Bradham Mary-Claire Roghmann 《Infection control and hospital epidemiology》2007,28(3):273-279
OBJECTIVE: To quantify the clinical impact of methicillin-resistance in Staphylococcus aureus causing infection complicated by bacteremia in adult patients, while controlling for the severity of patients' underlying illnesses. DESIGN: Retrospective cohort study from October 1, 1995, through December 31, 2003. PATIENTS AND SETTING: A total of 438 patients with S. aureus infection complicated by bacteremia from a single Veterans Affairs healthcare system. RESULTS: We found that 193 (44%) of the 438 patients had methicillin-resistant S. aureus (MRSA) infection and 114 (26%) died of causes attributable to S. aureus infection within 90 days after the infection was identified. Patients with MRSA infection had a higher mortality risk, compared with patients with methicillin-susceptible S. aureus (MSSA) infections (relative risk, 1.7 [95% confidence interval, 1.3-2.4]; P<.01), except for patients with pneumonia (relative risk, 0.7 [95% confidence interval, 0.4-1.3]). Patients with MRSA infections were significantly older (P<.01), had more underlying diseases (P=.02), and were more likely to have severe sepsis in response to their infection (P<.01) compared with patients with MSSA bacteremia. Patients who died within 90 days after S. aureus infection was identified were significantly older (P<.01) and more likely to have severe sepsis (P<.01) and pneumonia (P=.01), compared with patients who survived. After adjusting for age as a confounder, comorbidities, and pneumonia as an effect modifier, S. aureus infection-related mortality remained significantly higher in patients with MRSA infection than in those with MSSA infection, among those without pneumonia (hazard ratio, 1.8 [95% confidence interval, 1.2-3.0]); P<.01. CONCLUSIONS: The results of this study suggest that patients with MRSA infections other than pneumonia have a higher mortality risk than patients with MSSA infections other than pneumonia, independent of the severity of patients' underlying illnesses. 相似文献
48.
49.
50.