全文获取类型
收费全文 | 39927篇 |
免费 | 2676篇 |
国内免费 | 127篇 |
专业分类
耳鼻咽喉 | 370篇 |
儿科学 | 981篇 |
妇产科学 | 951篇 |
基础医学 | 5171篇 |
口腔科学 | 646篇 |
临床医学 | 3895篇 |
内科学 | 7707篇 |
皮肤病学 | 592篇 |
神经病学 | 4143篇 |
特种医学 | 1290篇 |
外科学 | 6560篇 |
综合类 | 476篇 |
现状与发展 | 1篇 |
一般理论 | 35篇 |
预防医学 | 3322篇 |
眼科学 | 1011篇 |
药学 | 2679篇 |
中国医学 | 114篇 |
肿瘤学 | 2786篇 |
出版年
2023年 | 224篇 |
2022年 | 400篇 |
2021年 | 890篇 |
2020年 | 548篇 |
2019年 | 803篇 |
2018年 | 1019篇 |
2017年 | 723篇 |
2016年 | 728篇 |
2015年 | 860篇 |
2014年 | 1334篇 |
2013年 | 1732篇 |
2012年 | 2815篇 |
2011年 | 2936篇 |
2010年 | 1646篇 |
2009年 | 1490篇 |
2008年 | 2677篇 |
2007年 | 2864篇 |
2006年 | 2686篇 |
2005年 | 2646篇 |
2004年 | 2528篇 |
2003年 | 2380篇 |
2002年 | 2180篇 |
2001年 | 397篇 |
2000年 | 359篇 |
1999年 | 395篇 |
1998年 | 447篇 |
1997年 | 401篇 |
1996年 | 391篇 |
1995年 | 313篇 |
1994年 | 303篇 |
1993年 | 265篇 |
1992年 | 229篇 |
1991年 | 196篇 |
1990年 | 165篇 |
1989年 | 152篇 |
1988年 | 169篇 |
1987年 | 160篇 |
1986年 | 139篇 |
1985年 | 150篇 |
1984年 | 148篇 |
1983年 | 158篇 |
1982年 | 197篇 |
1981年 | 174篇 |
1980年 | 149篇 |
1979年 | 90篇 |
1978年 | 115篇 |
1977年 | 115篇 |
1976年 | 90篇 |
1975年 | 92篇 |
1974年 | 78篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
61.
Philip J. Bossart M.D. F.A.C.E.P. Lenard Brunsdale M.D. Matt Hughes M.D. B. J. Manaster M.D. Ph.D. Anthony Doyle M.D. Kathy Murray M.D. David Tripp Ph.D. 《Emergency radiology》1997,4(1):26-29
To determine the utility of the lateral view of the chest in emergency department patients, records of all patients who had had 2-view chest x-rays ordered in the emergency department were reviewed retrospectively. A study radiologist recorded a reading of the posteroanterior (PA) radiograph alone. The lateral radiograph was then provided, along with the PA view, and a second reading was recorded. A comparison was then made between the first and second readings.A total of 417 sets of x-rays were included. The PA view alone successfully diagnosed or suspected 92% of pulmonary nodules, 95% of effusions, 97% of cases of emphysema, 98% of pneumonias, and 100% of cases of cardiomegaly, pulmonary edema, interstitial pulmonary disease, and atelectasis.In the emergency department patient population, lateral views of the chest have minimal diagnostic yield and therefore may be used selectively to safely decrease the amount of breast radiation exposure to young women. 相似文献
62.
63.
64.
Daniel F. Worsley Anthony Y. Fung David B. Coupland Cori G. Rexworthy George P. Sexsmith Brian C. Lentle 《European journal of nuclear medicine and molecular imaging》1992,19(6):441-444
Unlike conventional thallium-201 myocardial imaging, technetium-99m methoxyisobutylisonitrile (MIBI) requires separate stress and rest injections. We prospectively studied 148 consecutive patients referred for myocardial perfusion studies to determine the diagnostic value of rest images once normal exercise or dipyridamole tomographic images had been obtained. In patients referred with no history of previous myocardial infarction in whom the diagnosis of coronary artery disease was suspected, 45 of 109 (41%) patients had normal stress tomographic images. Obtaining rest images did not alter the final interpretation in any of these cases. From this we infer that in patients with normal images after exercise or dipyridamole administration and no past history of myocardial infarction, 99mTc-MIBI rest images are not required. This provides several advantages including increased speed of diagnosis, decreased patient radiation exposure, improved cost efficiency and decreased demand on tomographic camera time.
Offprint requests to: A.Y. Fung 相似文献
65.
66.
Luiz C M Pereira Vanessa N Palter Anthony E Lang William D Hutchison Andres M Lozano Jonathan O Dostrovsky 《Movement disorders》2004,19(12):1485-1492
The pathophysiological changes in neural activity that characterize multiple system atrophy (MSA) are largely unknown. We recorded the activity of pallidal neurons in 3 patients with clinical and radiological features of MSA who underwent unilateral microelectrode-guided pallidotomy for disabling parkinsonism. Findings in these patients were compared with 4 control patients with a clinical diagnosis of Parkinson's disease (PD). The position, firing rates, and firing patterns of single neurons in the pallidal complex were analyzed in both MSA and PD patients. The mean spontaneous firing rate of neurons in the internal segment of the globus pallidus internus (GPii) was significantly lower in MSA than in PD patients. There were no significant differences between MSA and PD patients, however, in firing rates of neurons in the external globus pallidus (GPe) or in the external segment of GPi (GPie). In addition, no significant differences in firing pattern were found between MSA and PD patients. In conclusion, this study has shown that firing rates of neurons in GPii but not in GPie and GPe are different in MSA patients compared with that in PD patients, a finding that may reflect the poor clinical results of pallidotomy reported in patients with MSA. 相似文献
67.
68.
Should cervical ultrasonography be a routine staging investigation for lung cancer patients with impalpable cervical lymph nodes? 总被引:3,自引:0,他引:3
Alan D L Sihoe Tak Wai Lee Anil T Ahuja Anthony P C Yim 《European journal of cardio-thoracic surgery》2004,25(4):486-491
OBJECTIVES: Detection of cervical N3 lymph nodes is currently not a routine preoperative investigation for lung cancer patients. We designed a study to assess if the frequency and accuracy of detection of metastatic cervical lymph nodes using cervical ultrasonography (US) and fine needle aspiration (FNA) justify their routine use in all lung cancer patients with impalpable cervical lymph nodes. METHODS: Fifty patients with suspected and potentially operable non-small cell lung cancer were enrolled. Patients with palpable cervical lymph nodes were excluded. In addition to routine preoperative investigations, all patients received cervical US to determine the presence of cervical lymph nodes. Nodes suspicious of harboring malignancy according to a specific set of sonographic criteria (which include shape, echogenicity, nodal architecture, and vascular patterns) were subjected to biopsy by ultrasound-guided FNA. RESULTS: Normal cervical lymph nodes were detected by cervical US in 30 patients (60%). Cervical lymph nodes suspicious of harboring malignancy were detected in 10 patients (20%). FNA confirmed cervical nodal metastasis in four of these patients (8%). The TNM staging of two patients (4%) was revised up to stage IIIb as a result, excluding them from further surgery. Cost analysis suggests this technique to be cost-effective when used as a routine preoperative investigation to exclude patients from unnecessary surgical intervention. No mortality or complications were encountered in all patients. CONCLUSIONS: Cervical US and FNA is a safe and cost-effective method of evaluating the status of impalpable cervical lymph nodes in lung cancer patients. Further study is warranted to establish the role of cervical US and FNA in lung cancer staging algorithms. 相似文献
69.
Michael F Parry Brenda Grant Anthony Iton Patricia D Parry Diane Baranowsky 《Infection control and hospital epidemiology》2004,25(11):929-932
BACKGROUND: The need to improve influenza vaccination delivery in our community became painfully clear during the winter of 1997-1998 when high rates of respiratory illness led to congestion in the emergency department and a critical shortage of hospital beds. In response, the local hospital and the Department of Health launched a collaborative program to increase influenza vaccine coverage in the community. METHODS: The partnership was designed to increase the number of citizens receiving influenza vaccine and to moderate the severity of lower respiratory tract illness during the winter season. A variety of methods were used to increase public awareness, enhance vaccine delivery, and create a relatively seamless service for the community. RESULTS: During three seasons, influenza vaccination rates increased by a relative 150%. This represented immunization of 16% of the entire community and more than 75% of residents older than 65 years. Hospital employee vaccination rates also rose from 34% to 58%. When compared with other hospitals in the county, the campaign reduced the average number of annual visits to the emergency department for all respiratory diagnoses by 34% and exacerbations of chronic obstructive pulmonary disease by 46%. CONCLUSIONS: This influenza vaccination program illustrates the potential for synergy that exists between local departments of health and community hospitals in successfully increasing vaccine delivery to the community. Furthermore, it also suggests that such efforts can be successful in reducing use of the emergency department, resulting in a positive impact on the health of the community. 相似文献
70.