全文获取类型
收费全文 | 22627篇 |
免费 | 2271篇 |
国内免费 | 1124篇 |
专业分类
耳鼻咽喉 | 156篇 |
儿科学 | 873篇 |
妇产科学 | 325篇 |
基础医学 | 2507篇 |
口腔科学 | 389篇 |
临床医学 | 2932篇 |
内科学 | 3403篇 |
皮肤病学 | 254篇 |
神经病学 | 1099篇 |
特种医学 | 1282篇 |
外国民族医学 | 6篇 |
外科学 | 2730篇 |
综合类 | 3199篇 |
现状与发展 | 3篇 |
一般理论 | 3篇 |
预防医学 | 1736篇 |
眼科学 | 428篇 |
药学 | 2123篇 |
18篇 | |
中国医学 | 970篇 |
肿瘤学 | 1586篇 |
出版年
2024年 | 74篇 |
2023年 | 293篇 |
2022年 | 710篇 |
2021年 | 1013篇 |
2020年 | 760篇 |
2019年 | 658篇 |
2018年 | 786篇 |
2017年 | 704篇 |
2016年 | 641篇 |
2015年 | 944篇 |
2014年 | 1127篇 |
2013年 | 1089篇 |
2012年 | 1507篇 |
2011年 | 1553篇 |
2010年 | 1158篇 |
2009年 | 892篇 |
2008年 | 1112篇 |
2007年 | 1056篇 |
2006年 | 1065篇 |
2005年 | 956篇 |
2004年 | 743篇 |
2003年 | 689篇 |
2002年 | 635篇 |
2001年 | 551篇 |
2000年 | 427篇 |
1999年 | 395篇 |
1998年 | 340篇 |
1997年 | 328篇 |
1996年 | 273篇 |
1995年 | 210篇 |
1994年 | 210篇 |
1993年 | 183篇 |
1992年 | 220篇 |
1991年 | 196篇 |
1990年 | 162篇 |
1989年 | 198篇 |
1988年 | 199篇 |
1987年 | 163篇 |
1986年 | 173篇 |
1985年 | 168篇 |
1984年 | 127篇 |
1983年 | 98篇 |
1982年 | 91篇 |
1981年 | 86篇 |
1980年 | 81篇 |
1979年 | 111篇 |
1978年 | 71篇 |
1976年 | 70篇 |
1975年 | 70篇 |
1973年 | 74篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
The utilization of medical services by patients is an important determinant of doctor productivity, but this factor does not appear to have been given much attention in previous studies. In order to answer the question of why is there a wide variation in doctor output at low level medical facilities in China, an analytical framework of doctor productivity and utilization is developed. The simulation model is used to produce data that can be analyzed by such a framework. Great uncertainty about patient flows is one reason for the average lower and varying doctor productivity in lower level health facilities. Until uncertainty can be reduced, more flexibility is needed at the lower level to cope with changing utilization patterns and patient characteristics. The management by doctors of non-patient care activities (preventive programmes, medical research, teaching, and administration) is crucial to any approach to using doctor resources more effectively and efficiently. 相似文献
42.
Prospective survey of investigations in outpatients referred with iron deficiency anaemia. 总被引:8,自引:1,他引:7 下载免费PDF全文
Recent evidence has suggested that colonic neoplasm may be missed in patients presenting with iron deficiency anaemia unless colonic investigations are performed on all patients even when an alternative cause has been found. This study prospectively surveyed 114 consecutive patients referred from family practitioners to an outpatient clinic for the investigation of iron deficiency anaemia to determine the diagnoses contributing to the anaemia, the usefulness of certain clinical features, and the role of colonic and other investigations in obtaining the diagnosis. Upper gastrointestinal lesions contributing to anaemia were identified in 45 patients while colonic lesions were found in 18. Twenty three patients had a non-gastrointestinal cause for anaemia and in 12 patients no cause was found. Only two patients were identified as having colonic neoplasia (a small adenomatous polyp in each case) coexisting with upper gastrointestinal lesions. Symptoms and signs had a sensitivity and specificity of upper gastrointestinal disease of 50% and 83% respectively, and 44% and 80% for colonic disease. Endoscopy had a high yield (42%) and duodenal biopsy identified coeliac disease in three patients (two were aged > 70 years) each of whom had normal folate values. Barium enema had a yield of 13%. All colonic carcinomas occurred in patients > 65 years. The coexistence of colonic cancer or large polyps with an upper gastrointestinal lesion identified at endoscopy was rare in outpatients referred from family practitioners. Clinical symptoms and signs were poor indicators of the investigations that will detect a cause for the anaemia.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
43.
乳腺占位病变的高场强MRI诊断价值 总被引:1,自引:1,他引:0
目的 :总结乳腺良恶性占位病变在高场强MRI的影像表现 ,评价高场强MRI对乳腺良恶性病变的诊断价值。方法 :搜集1996~ 2 0 0 4年间经手术病理证实的 4 3例乳腺良恶性占位病变的MRI资料 ,分析其影像表现。结果 :典型乳腺良、恶性病变 ,高场强MR平扫即能准确诊断 ,而部分非典型良、恶性病灶 ,增强扫描形态、信号变化也有一定的重叠。结论 :MRI技术能够充分显示病变形态及与周围组织结构之间的关系 ,是建议活检或预防性手术的最有力的依据。但是 ,MRI平扫、增强技术对乳腺非典型病变 ,仍然有局限性 相似文献
44.
45.
46.
OBJECTIVE: To study the value of serum progesterone in selecting the candidate patients with ectopic pregnancy (EP) for methotrexate (MTX) treatment and in monitoring the effect of the treatment. METHODS: Thirty-seven EP patients who were given single-dose intramuscular injection with 50 mg/m2 MTX were divided into success and failure groups according to the effect of the treatment. The serum progesterone concentrations in these patients were measured and compared between the 2 groups, and the receiver-operator curves (ROC) were used to determine the critical serum progesterone levels for assessing the effect of MTX treatment. The time consumed respectively by serum progesterone and beta-human chorionic gonadotrophin (beta-hCG) decreasing to below normal level was also compared. RESULTS: The serum progesterone concentrations of the success group (7.93+/-2.02 ng/ml) were significantly lower than those of the failure group (14.53+/-1.72 ng/ml, P<0.05). The recommended critical level for assessing the effect of MTX treatment for EP patients was 11 ng/ml according to the ROC, and the time for serum progesterone decreasing to below normal level was significantly less than that for beta-hCG. CONCLUSION: Serum progesterone can be used as an index for selecting candidate EP patients for MTX treatment, and also as a good indicator for assessing the therapeutic effect after treatment. 相似文献
47.
48.
49.
50.
R Long 《中华耳鼻咽喉科杂志》1989,24(1):34-6, 63
One hundred and seventy patients with nasal polyps were studied. According to the history, skin tests with inhalant allergens, determination of serum nasal secretion and polyp fluid IgE, and X-ray films of nasal sinuses, it was suggested that 93.5% of them might have complicated with allergic diseases, 87.7% with sinusitis. A relationship between local IgE production and the eosinophil infiltration of polyps existed. This study suggests that allergic process acting locally on the mucous membrane of the nose is the etiologic factor and bacterial allergy probably contributes to the development of nasal polyps. In order to prevent the recurrence after polypectomy, antiallergic management combined with antibiotics and drainage of infected sinuses may be necessary in most cases. 相似文献