全文获取类型
收费全文 | 1317篇 |
免费 | 66篇 |
国内免费 | 6篇 |
专业分类
耳鼻咽喉 | 8篇 |
儿科学 | 39篇 |
妇产科学 | 202篇 |
基础医学 | 123篇 |
口腔科学 | 37篇 |
临床医学 | 88篇 |
内科学 | 264篇 |
皮肤病学 | 20篇 |
神经病学 | 60篇 |
特种医学 | 44篇 |
外国民族医学 | 1篇 |
外科学 | 220篇 |
综合类 | 24篇 |
预防医学 | 83篇 |
眼科学 | 19篇 |
药学 | 79篇 |
中国医学 | 2篇 |
肿瘤学 | 76篇 |
出版年
2023年 | 13篇 |
2022年 | 30篇 |
2021年 | 30篇 |
2020年 | 28篇 |
2019年 | 35篇 |
2018年 | 52篇 |
2017年 | 25篇 |
2016年 | 20篇 |
2015年 | 23篇 |
2014年 | 45篇 |
2013年 | 65篇 |
2012年 | 102篇 |
2011年 | 96篇 |
2010年 | 49篇 |
2009年 | 43篇 |
2008年 | 59篇 |
2007年 | 72篇 |
2006年 | 76篇 |
2005年 | 64篇 |
2004年 | 58篇 |
2003年 | 66篇 |
2002年 | 50篇 |
2001年 | 24篇 |
2000年 | 34篇 |
1999年 | 24篇 |
1998年 | 8篇 |
1997年 | 14篇 |
1996年 | 3篇 |
1995年 | 11篇 |
1993年 | 4篇 |
1992年 | 23篇 |
1991年 | 13篇 |
1990年 | 7篇 |
1989年 | 19篇 |
1988年 | 9篇 |
1987年 | 8篇 |
1986年 | 13篇 |
1985年 | 8篇 |
1984年 | 3篇 |
1983年 | 4篇 |
1979年 | 3篇 |
1977年 | 2篇 |
1974年 | 5篇 |
1973年 | 7篇 |
1972年 | 5篇 |
1971年 | 10篇 |
1970年 | 8篇 |
1969年 | 8篇 |
1968年 | 3篇 |
1967年 | 2篇 |
排序方式: 共有1389条查询结果,搜索用时 0 毫秒
1.
2.
The management of a neck mass: presenting feature of an asymptomatic head and neck primary malignancy? 总被引:2,自引:1,他引:1
M Barakat L M Flood V H Oswal R W Ruckley 《Annals of the Royal College of Surgeons of England》1987,69(4):181-184
Malignancy of the upper aerodigestive tract is not always associated with obvious localizing symptoms. Presentation may then only be prompted by the appearance of a hard mass in the neck, a metastasis to a cervical lymph node. Neck exploration without a prior diligent search for an occult head and neck primary tumour is to be avoided as it compromises subsequent treatment. The diagnostic investigation of 112 patients complaining solely of a painless and enlarging neck swelling is reviewed. An otolaryngologic examination identified an asymptomatic malignancy of the head and neck in 72 patients (64%). Excision biopsy of the neck mass was required to achieve a diagnosis in only 29 (29%) of those patients who had not already undergone surgery. These results are presented to emphasize the need for a specialist examination of the head and neck prior to embarking on excision of any suspicious neck mass. 相似文献
3.
4.
5.
We provide microscopic evidence that motile rod-shaped forms of Ramlibacter tataouinensis TTB310 are formed from dividing cyst-like cells. Careful estimation of the size of the two morphotypes was conducted using optical and transmission electron microscopy (TEM). The cyst-like cell was shown to be a sphere with a diameter Dc=850 nm. The rod-shaped form was a round-ended cylinder with length Lr=2.91 microm and diameter Dr=239 nm. The membrane area of the two morphotypes was the same. However, the formation of rods from cysts involved loss of two-thirds of the cell volume. TEM showed that, prior to division and transition into rods, cysts contained condensed cytoplasmic material. These results suggest that the morphological transition occurs by pure reshaping of cells. 相似文献
6.
Tibor Hortobágyi Joseph A. Houmard Richard G. Israel John W. Carpenter Judy Heath Hisham A. Barakat 《European journal of applied physiology》1993,67(3):226-230
Summary The purpose of this study was to determine the effects of short-term exercise cessation on lipid and lipoprotein profile and insulin sensitivity in highly trained runners (n=12; mean age 19.9 years) and power athletes (n=12; mean age 24.4 years). Following 14 days of exercise cessation, running time to exhaustion and maximal oxygen uptake decreased by 9.2% and 4.8% (P < 0.05) in the runners, while in the power athletes one repetition maximum squat and bench press did not change (P>0.05). No changes occurred in body composition. Data from a 2-h oral glucose tolerance test revealed an impairment of the glycemic state in all athletes (P<0.05). In contrast, exercise cessation did not significantly (P>0.05) alter plasma levels of cholesterol, triglycerides, and low density (LDL) and high density lipoprotein (HDL). No changes were observed in HDL2, HDL2b, and HDL3 subfractions, LDL diameter, and qualitative LDL pattern (P>0.05). These data thus suggest that despite a decrease in insulin sensitivity, short-term exercise cessation, independent of exercise mode, was insufficient to alter plasma lipid and lipoprotein profiles in well-trained athletes. 相似文献
7.
Harrath R Bourlet T Delézay O Douche-Aourik F Omar S Aouni M Pozzetto B 《Journal of medical virology》2004,74(2):283-290
Although the transmission of coxsackievirus B3 occurs mainly via the oral route, little is known about the primary replication and persistence of this agent in the intestine. To address this question, BALB/c mice were inoculated by gavage with coxsackievirus B3, Nancy strain. The mice were killed from 1 hr to 90 days after infection. The viral markers were detected in the small intestine using RT-PCR, cell culture and detection of VP1 protein. Coxsackievirus B3 was detected positive by the three methods from hr 2 to day 45 after infection. By using monoclonal antibodies directed towards VP1, CD40 and CD26, the virus was shown to be present in the lymphocytes of the mucosa as soon as 2 hr after infection; in contrast, no virus was detected in the epithelial cells lining the intestinal lumen. Further experiments were performed to evaluate the capacity of coxsackievirus B3 to establish a persistent infection in two intestinal cell lines. In contrast to HT29 cells, the CaCo-2 cells were shown to develop a persistent infection for up to 20 passages, as demonstrated by the detection of viral RNA and VP1 protein. This study provides further evidence that, after infection by the oral route, the viral particles are concentrated in the lymphocytes of the mucosal layer. In addition, the results suggest that coxsackievirus B3 is capable of establishing a persistent infection in the small intestine that may act as a reservoir of viral particles for the delayed spread of the virus to other target organs. 相似文献
8.
9.
BACKGROUND: To evaluate the efficacy of the peripheral leukocyte count and chest X-rays as an index which could be used in the early assessment of the severity of acute pancreatitis in an Emergency Room. METHODS: We prospectively evaluated the peripheral leukocyte count and the findings of chest X-rays in 181 consecutive patients (102 males, 79 females, mean age 61 years, range 16-97) who were admitted to our Emergency Department with acute pancreatitis. One hundred twenty six patients had mild pancreatitis and 55 had severe pancreatitis. The peripheral leukocyte count and the chest X-rays were evaluated in all patients upon admission. The Ranson criteria were also assessed. RESULTS: Using a cut off value of 13,000/mm3, 45% of the patients with severe pancreatitis and 17% of those with mild acute pancreatitis had a peripheral leukocyte count greater than 13,000/mm3. Pleural or pulmonary alterations observed on chest X-ray were found in 66% of patients with severe pancreatitis and in 2% of those with mild acute pancreatitis. A peripheral leukocyte count greater than 13,000/mm3 and/or pleural or pulmonary alterations present on chest X-ray were found in 78% of the patients with severe pancreatitis and in 19% of those with mild pancreatitis. The Ranson criteria greater than or equal to three were found in 45% of the patients with severe acute pancreatitis and in 16% of those with the mild form of the disease. The positive predictive value was 92% for the presence of alterations on the chest X-rays, 64% for the alteration of at least one of the abnormal findings on the chest X-ray and a peripheral leukocyte count greater than 13,000/mm3, 56% for a peripheral leukocyte count greater than 13,000/mm3, and 54% for the presence of Ranson criteria greater than or equal to three. The negative predictive values were similar. CONCLUSIONS: The presence of pleural or pulmonary alterations on chest X-rays may be useful in the Emergency Room for the early identification of patients with severe acute pancreatitis. 相似文献
10.
Aeshah Ibrahim Alhosain Ghedeir M. Alshammari Barakat Lafi Almoteri Mohammed A. Mohammed Manal Abdulaziz Binobead Mohammed Abdo Yahya 《Nutrients》2022,14(10)
This cross-sectional study examines the influence of long-term gluten-free diet (GFD) consumption on nutritional status, body composition, and associated factors in adult Saudi females with celiac diseases (CD). Fifty-one patients who have been diagnosed with CD and have been on GFD for more than 1 year were included in this study where data regarding their dietary pattern, as well as a complete analysis of their anthropometric parameters, vitamins B12 and D levels, and complete blood count (CBC), were collected. Data have shown that all included patients showed a reduced intake in all micro and macro-nutrients, as well as vitamin D, folate, calcium, and iron. However, the vast majority of all measured hematological parameters and blood indices were within the expected reference range. In addition, 51%, 43.1%, and 60.8% of the patients showed low waist/hip ratio (WHR), decreased level of total body fat (BF), and decreased level of visceral fat (VF), respectively, whereas 33.3% were slim. The poor educational level and some psychosocial factors were associated with the poor nutritional status of the patients. In conclusion, the GFD-dependent intake by female patients with CD adversely affects their nutritional intake and anthropometric indices and leads to a deficiency in major nutrients, vitamins, and ions. 相似文献