全文获取类型
收费全文 | 105365篇 |
免费 | 42461篇 |
国内免费 | 139篇 |
专业分类
耳鼻咽喉 | 2005篇 |
儿科学 | 4864篇 |
妇产科学 | 1046篇 |
基础医学 | 19587篇 |
口腔科学 | 7869篇 |
临床医学 | 14324篇 |
内科学 | 28785篇 |
皮肤病学 | 8209篇 |
神经病学 | 15198篇 |
特种医学 | 2831篇 |
外科学 | 16971篇 |
综合类 | 112篇 |
一般理论 | 28篇 |
预防医学 | 7618篇 |
眼科学 | 1589篇 |
药学 | 7621篇 |
中国医学 | 1319篇 |
肿瘤学 | 7989篇 |
出版年
2023年 | 310篇 |
2022年 | 767篇 |
2021年 | 2427篇 |
2020年 | 5727篇 |
2019年 | 11610篇 |
2018年 | 11165篇 |
2017年 | 12168篇 |
2016年 | 12841篇 |
2015年 | 12890篇 |
2014年 | 13049篇 |
2013年 | 13764篇 |
2012年 | 6462篇 |
2011年 | 6737篇 |
2010年 | 10221篇 |
2009年 | 6284篇 |
2008年 | 3791篇 |
2007年 | 2601篇 |
2006年 | 2339篇 |
2005年 | 1923篇 |
2004年 | 1722篇 |
2003年 | 1608篇 |
2002年 | 1522篇 |
2001年 | 1364篇 |
2000年 | 1243篇 |
1999年 | 734篇 |
1998年 | 190篇 |
1997年 | 139篇 |
1996年 | 122篇 |
1995年 | 83篇 |
1994年 | 109篇 |
1993年 | 63篇 |
1992年 | 227篇 |
1991年 | 209篇 |
1990年 | 136篇 |
1989年 | 154篇 |
1988年 | 133篇 |
1987年 | 88篇 |
1986年 | 114篇 |
1985年 | 91篇 |
1984年 | 75篇 |
1983年 | 71篇 |
1982年 | 37篇 |
1980年 | 52篇 |
1979年 | 72篇 |
1978年 | 41篇 |
1977年 | 38篇 |
1976年 | 38篇 |
1973年 | 38篇 |
1969年 | 40篇 |
1968年 | 49篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
61.
E. Andrs G. Kaltenbach E. Noel M. Noblet‐Dick A.‐E. Perrin T. Vogel J.‐L. Schlienger M. Berthel J. F. Blickl 《International journal of laboratory hematology》2003,25(3):161-166
Background: It has been suggested that oral cobalamin (vitamin B12) therapy may be an effective therapy for treating cobalamin deficiencies related to food‐cobalamin malabsorption. However, the duration of this treatment was not determined. Patients and method: In an open‐label, nonplacebo study, we studied 30 patients with established cobalamin deficiency related to food‐cobalamin malabsorption, who received between 250 and 1000 μg of oral crystalline cyanocobalamin per day for at least 1 month. Endpoints: Blood counts, serum cobalamin and homocysteine levels were determined at baseline and during the first month of treatment. Results: During the first month of treatment, 87% of the patients normalized their serum cobalamin levels; 100% increased their serum cobalamin levels (mean increase, +167 pg/dl; P < 0.001 compared with baseline); 100% had evidence of medullary regeneration; 100% corrected their initial macrocytosis; and 54% corrected their anemia. All patients had increased hemoglobin levels (mean increase, +0.6 g/dl) and reticulocyte counts (mean increase, +35 × 106/l) and decreased erythrocyte cell volume (mean decrease, 3 fl; all P < 0.05). Conclusion: Our findings suggest that crystalline cyanocobalamin, 250–1000 μg /day, given orally for 1 month, may be an effective treatment for cobalamin deficiencies not related to pernicious anemia. 相似文献
62.
63.
Nuno Fonseca Filomena Caetano José Santos Filipe Seixo Leonel Bernardino Isabel Silvestre Paula Cardoso Filomena Segurado Lopes Inês 《Revista portuguesa de cardiologia》2004,23(3):365-375
INTRODUCTION: In patients (pts) with atrial fibrillation (AF) of more than 48 hours' duration, electrical cardioversion (ECV) should only be performed after 3 weeks of effective anticoagulation. Transesophageal echocardiography (TEE) allows earlier ECV; however, despite exclusion of thrombi in the atrium and left atrial appendage (LAA), cases of thromboembolism related to ECV have been documented in AF. To define a low-risk group for cardioversion without previous anticoagulation, pts were selected for immediate ECV if no thrombi or dynamic spontaneous echo contrast (auto-contrast) were found after TEE and if LAA velocity was more than 0.25 m/sec. METHODS AND RESULTS: We performed TEE in 31 consecutive pts referred for ECV for AF of more than 48 hours' duration and without previous anticoagulation. After TEE the pts eligible for immediate ECV began anticoagulation with low molecular weight heparin (enoxaparin), subcutaneously in therapeutic doses, together with warfarin immediately before cardioversion. Enoxaparin was continued until an INR of over 2 was reached. Based on the TEE findings, the pts were divided in 2 groups: immediate ECV, group A, 20 pts with a mean age of 62 +/- 13 years, 6 female; and conventional therapy with warfarin before ECV, group B, 11 pts, mean age of 67 +/- 10 years (p < 0.05), 2 female. None of the pts in either group had mitral stenosis or previous episodes of thromboembolism. The mean transverse diameter of the left atrium in the 31 pts was 47 +/- 4.5 mm, without statistically significant differences between the 2 groups. Of the 11 pts in group B, 3 had a thrombus in the LAA, 6 dynamic spontaneous echo contrast and the remainder LAA velocities of less than 0.25 m/sec. ECV was achieved in all the pts, with no complications. Oral anticoagulation was maintained for at least a month. At one month, sinus rhythm was maintained in 75% of group A and 45% of group B (p < 0.01). CONCLUSION: In pts with AF of more than 48 hours' duration and no previous history of thromboembolism, the use of our exclusion criteria during TEE enabled stratification of a low-risk population for immediate ECV, which was accomplished effectively and safely in 2/3 of the pts. This strategy is associated with early symptomatic improvement, and may contribute to maintenance of sinus rhythm after one month, which was significantly better than in the pts who had prolonged therapy with warfarin before ECV, despite the differences found in age and left ventricular function. 相似文献
64.
Felipe Scalco Manzano DDSc Lucia Mercuri Granero MD Danilo Masiero MD Maria Teresa Botti Rodrigues dos Santos DDSc PhD 《Special care in dentistry》2004,24(4):235-239
This study was designed to verify the safety and efficacy of botulinum toxin type A (BTX-A) used as a neuromuscular block on spastic masticatory musculature of children with cerebral palsy. Six patients who had spastic-tetraplegic cerebral-palsy, aged 5 to 20 years were selected. All patients had spasticity of the jaw muscles, bruxism, lower lip trauma, limited mouth opening, and difficulties in cleaning the oral cavity. The patients were sedated under general anesthesia, while the dentist injected the masseter and temporalis muscles bilaterally with 150 and 75 units of BTX-A each. Clinical examinations were conducted at 7, 14, 30, and 90 days after the initial appointment. We found statistically significant decreases in muscle spasticity and bruxism ( p = 0.002), improved inter-incisal opening ( p = 0.002), improved oral hygiene ( p = 0.031), and less lower lip trauma ( p = 0.060) after the neuromuscular blocking. 相似文献
65.
The objective of this study was to compare the clinical and laboratory consequences of left and right displacement of the abomasum (LDA and RDA), short‐ and long‐term survival after surgery and the findings in cows, that could not be cured by omentopexy. Data from 564 cases of displaced abomasum (466 LDA, 98 RDA) were analysed retrospectively. Clinical and laboratory findings were compared between the two manifestations of DA. Survival was assessed after 10 days and after 15 months. Necropsy was carried out on cows that died or were killed. On arrival at the clinic, left displacement of the abomasum (LDA) cows had been recognized as diseased for longer. LDA occurred earlier in lactation, and more cows with right displacement of the abomasum (RDA) were pregnant. Overall clinical symptoms were more severe in RDA than in LDA cows. Heart rate was higher, body temperature was lower, inanition, abnormal faeces and ruminal stasis were more frequent in RDA cows. Leucocyte counts were higher, and potassium and chloride levels were lower in RDA cows. Acetonuria was more frequent in LDA cows. More LDA than RDA cows were released from the clinic as cured (82.0% versus 74.5%). However, survival after the early post‐surgical period was similar for RDA and LDA cows. At necropsy, diseases of the gastrointestinal system were the predominant finding in RDA cows, while in LDA cows, diseases of the liver and other concurrent diseases were more important. 相似文献
66.
67.
68.
R. Kazi V. Prasad R. Venkitaraman C.M. Nutting P. Clarke P. Rhys‐Evans K.J. Harrington 《Clinical otolaryngology》2006,31(6):525-530
Objective: To determine the effects of a total laryngectomy on the swallow and subsequent quality of life in head and neck cancer patients. Design: Cross‐sectional single centre cohort study. Setting: Head and Neck Oncology Unit, Tertiary Referral Unit. Patients: Sixty‐two patients who underwent total laryngectomy at our centre participated in the study. Methods: Subjects were stratified by age, sex, tumour stage, other procedures such as myotomy and nerve re‐implantation. Pharyngectomy, glossectomy, flap reconstruction, neck dissection and previous radio‐ and chemotherapy were also assessed to see if they affected swallow and subsequent quality of life. Main outcome was measured using the MD Anderson Dysphagia Inventory questionnaire. Results: Responses were received from 46 males and 16 females (response rate of 80.5%) with a mean age of 64.7 years (SD 9.4). Median follow‐up in patients was 90 months (range 1–276). The mean MD Anderson Dysphagia Inventory total score in our series of patients was 77.7 (SD 16.6). MD Anderson Dysphagia Inventory global score was 79.4 (SD 22.6), Emotional score was 77.7 (SD 17.8), Functional score 81.3 (SD 15.9) and Physical score was 74.1(SD 18). Statistically significant differences were seen between the emotional scores of glossectomised and non‐glossectomised patients (Mann Whitney, P = 0.04). No significant correlation was seen between the subscale scores and the remaining treatment variables such as age, gender, site, tumour stage, myotomy, nerve implantation, radiotherapy, reconstruction and major complications. Conclusion: This questionnaire study is the largest of its type to assess the swallow of patients who have undergone laryngectomy at a single centre. The overall result confirmed that most patients had a subjectively good swallow. Only glossectomy and the method of PE segment closure were shown to significantly affect swallowing outcomes following surgery. We recommend further work especially prospective studies pre and post surgery using this or similarly validated instruments to fully assess swallow in the laryngectomy population. 相似文献
69.
P. E. Marchiori M. dos Reis M. E. Quevedo M. Scaff W. Cossermelli J. L. Assis R. M. de Oliveira 《Acta neurologica Scandinavica》1989,80(5):387-389
Radioimmunoassay techniques were used to detect antibodies to the acetylcholine receptor (AAChR) in 164 patients with adult-onset myasthenia gravis. AAChR levels above 0.6 nM/l were considered pathological and were found in 67% of the patients with an average value of 58.99 +/- 125.02 nM/l (0.6-900.0). Correlation, with clinical functional status, the histopathological thymus alterations and the different therapeutics used did not disclose any statistically significant differences. 相似文献
70.