全文获取类型
收费全文 | 443699篇 |
免费 | 40012篇 |
国内免费 | 29430篇 |
专业分类
耳鼻咽喉 | 3879篇 |
儿科学 | 4990篇 |
妇产科学 | 6212篇 |
基础医学 | 58171篇 |
口腔科学 | 7601篇 |
临床医学 | 59261篇 |
内科学 | 65271篇 |
皮肤病学 | 4409篇 |
神经病学 | 23803篇 |
特种医学 | 16037篇 |
外国民族医学 | 260篇 |
外科学 | 44222篇 |
综合类 | 70100篇 |
现状与发展 | 88篇 |
一般理论 | 31篇 |
预防医学 | 28280篇 |
眼科学 | 12434篇 |
药学 | 47031篇 |
431篇 | |
中国医学 | 24197篇 |
肿瘤学 | 36433篇 |
出版年
2024年 | 1465篇 |
2023年 | 6611篇 |
2022年 | 17222篇 |
2021年 | 21803篇 |
2020年 | 16005篇 |
2019年 | 14312篇 |
2018年 | 15170篇 |
2017年 | 13447篇 |
2016年 | 12701篇 |
2015年 | 19199篇 |
2014年 | 23899篇 |
2013年 | 21597篇 |
2012年 | 31414篇 |
2011年 | 34954篇 |
2010年 | 22611篇 |
2009年 | 17747篇 |
2008年 | 23582篇 |
2007年 | 23628篇 |
2006年 | 23048篇 |
2005年 | 22185篇 |
2004年 | 15033篇 |
2003年 | 14034篇 |
2002年 | 12146篇 |
2001年 | 10577篇 |
2000年 | 10889篇 |
1999年 | 11272篇 |
1998年 | 6920篇 |
1997年 | 7034篇 |
1996年 | 5409篇 |
1995年 | 4942篇 |
1994年 | 4166篇 |
1993年 | 2771篇 |
1992年 | 3698篇 |
1991年 | 3221篇 |
1990年 | 2834篇 |
1989年 | 2524篇 |
1988年 | 2163篇 |
1987年 | 1868篇 |
1986年 | 1610篇 |
1985年 | 1316篇 |
1984年 | 887篇 |
1983年 | 668篇 |
1982年 | 506篇 |
1981年 | 458篇 |
1980年 | 383篇 |
1979年 | 412篇 |
1978年 | 274篇 |
1977年 | 300篇 |
1976年 | 260篇 |
1974年 | 258篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
42.
Jing‐Ping Zhang Limin Zheng Jiang‐Hai Wang Karl‐Eric Magnusson Xin Liu 《Phytotherapy research : PTR》2009,23(6):844-850
Ganoderma sinensis has been used widely in Oriental countries for the prevention and treatment of various diseases including cancer. Previous studies have shown that the lipid extract from Ganoderma exhibits direct cytotoxicity against tumor cells. Here, it is reported that the lipid extract from germinating G. sinensis spores, at lower concentrations that have no direct tumoricidal activity, induce potent antitumor immune responses in human monocytes/macrophages. Upon stimulation with the lipid extract, monocytes/macrophages exhibited markedly increased production of proinflammatory cytokines and surface expression of costimulatory molecules. Conditioned medium from stimulated cells effectively suppressed the growth of tumor cells. Apparently, the lipid extract triggered macrophage activation via a mechanism different from that associated with LPS. Moreover, it was observed that the lipid extract could partially re‐establish the antitumor activity of the immunosuppressive tumor‐associated macrophages. These results indicated that in addition to its direct tumoricidal activity, the lipid extract from G. sinensis spores could exert antitumor activity by stimulating the activation of human monocytes/macrophages. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
43.
Fu-Wei Wang Yu-Wen Chiu Ming-Shium Tu Ming-Yueh Chou Chao-Ling Wang Hung-Yi Chuang 《International archives of occupational and environmental health》2009,82(7):819-825
Purpose There has been increasing interest in the occupational health of workers in small enterprises, especially in developing countries.
This study examines the association between psychosocial job characteristics and fatigue, and attempts to identify risk factors
for fatigue among workers of small enterprises in southern Taiwan.
Methods A structured questionnaire was administered to workers receiving regular health examinations between August 2005 and January
2006. The questionnaire collected demographic information and data on working conditions, personal health status and life
styles. It also collected information on psychosocial job characteristics, fatigue and psychological distress using three
instruments.
Results A total of 647 workers with mean age of 43.7 were completed. Probable fatigue was found in 34.6% of the sample. Fatigue was
found by multiple logistic regressions to be associated with the lack of exercise, working in shifts, depression score and
lack of social support at workplace.
Conclusions This study found associations between life style, psychosocial job characteristics and fatigue. Because the high prevalence
of probable fatigue was found in such small enterprises, the authors suggest that a short interview with some quick questionnaires
in health checkup for these small enterprise workers are helpful to early detect psychosocial and fatigue problems. 相似文献
44.
Yulu Miao Mingxia Zhang Yulin Nie Wan Zhao Bin Huang Zhengming Jiang Shaoxiong Yu Zhibin Huang Hongjin Fu 《中国神经再生研究》2007,2(2):126-128
BACKGROUND: Besides local changes of cranial parenchymal cells, hemorrhage, etc., severe traumatic brain injuries also cause the changes of total body fluid and various functions, and the changes of lymphocytes and T lymphocyte subsets should be paid more attention to. OBJECTIVE: To reveal the changing laws of T lymphocyte subsets after severe traumatic brain injury, and compare with mild to moderate brain injury. DESIGN: A comparative observation. SETTINGS: Department of Neurosurgery, Longgang District Buji People's Hospital of Shenzhen City; Central Laboratory of Shenzhen Hospital of Prevention and Cure for Chronic Disease. PARTICIPANTS: All the subjects were selected from the Department of Neurosurgery, Longgang District Buji People's Hospital of Shenzhen City from August 2002 to August 2005. Thirty patients with severe brain injury, whose Glasgow coma score (GCS) was ≤ 8 points, were taken as the experimental group, including 21 males and 9 females, aging 16 - 62 years. Meanwhile, 30 patients with mild traumatic brain injury were taken as the control group (GCS ranged 14- 15 points), including 18 males and 12 females, aging 15 -58 years. All the subjects were in admission at 6 hours after injury, without disease of major organs before injury Informed consents were obtained from all the patients or their relatives. METHODS: (1) The T lymphocytes and the subsets in peripheral blood were detected with immunofluorescent tricolor flow cytometry at l, 3, 7 and 14 days after injury in both groups. (2) The conditions of pulmonary infections were observed at 4 days after injury. The differences of measurement data were compared with the t test. MAIN OUTCOME MEASURES: Changes of T lymphocytes subsets at 1 - 14 days after severe and mild or moderate traumatic injury. RESULTS: Finally, 28 and 25 patients with mild to moderate traumatic brain injury, whereas 25 and 21 patients with severe traumatic brain injury were analyzed at 7 and 14 days respectively, and the missed ones died due to the development of disease. (1) Changes of T lymphocyte subsets: At 1 and 3 days after injury, CD3, CD4, CD8, CD4/CD8 began to decrease, whereas CD8 increased in the experimental group, which were very significantly different from those in the control group (t =2.77 - 3.26, P 〈 0.01), and began to recover at 7 days, which were significantly different from those in the control group (t = 2.06 - 2.24, P 〈 0.05), and generally recovered to the normal levels at 14 days (P 〉 0.05). (2) Conditions of pulmonary infections: At 4 days after injury, the rate of pulmonary infection was significantly different between the experimental group and control group [73% (22/30), 0, x2=37.29, P 〈 0.01]. CONCLUSION: Patients with severe traumatic brain injury suffer from damages of cellular immune function at early period (within 7 days), and they are easily to be accompanied by pulmonary infections. 相似文献
45.
L Wang 《中华耳鼻咽喉科杂志》1989,24(4):209-11, 254
For a systematic understanding of the effect of diving on hearing ability and middle and inner ear morphology, we have carried out simulated tests on 65 healthy guinea pigs, under water 60 meters deep, and then decompress rapidly. The tests proved that hearing ability changed most significantly 7 days after diving. After diving, all tympanogram curves, except those in 3 ears, changed to type B. Thirty-nine (37.85%) middle ears had been damaged, 4 (3.88%) had inner ears injured, as seen under light microscope. During decompression, three animals had nystagmus. Screen electronmicroscopy showed hair cell destruction and hair derangement. Transmission electronmicroscopy showed mitochondria damage. The results showed that damages in middle and inner ears were mainly mechanical, sometimes metabolic. 相似文献
46.
Intrathecal morphine for post-thoracotomy pain 总被引:1,自引:0,他引:1
We wished to investigate possible differences in the duration of postoperative analgesia and the incidence of respiratory depression after the intrathecal injection in the lumbar area of 10 micrograms/kg morphine in hypobaric and hyperbaric solution for relief of post-thoracotomy pain. Twenty-nine patients received morphine plus dextrose (hyperbaric) and 21 received morphine in preservative-free normal saline. The duration of analgesia was longer with the morphine in the normal saline group than in the hyperbaric group (P less than 0.04). One patient developed delayed respiratory depression. Our data support the use of morphine in normal saline mixtures for greater duration of analgesia after thoracic operations. 相似文献
47.
48.
五倍南星膏外敷治疗颌下淋巴结炎26例 总被引:2,自引:2,他引:0
王象腾 《中华实用中西医杂志》2005,18(20):1300-1300
自1998年2月-2004年12月共应用五倍南星膏治疗颌下淋巴结炎病人26例,收到良好的临床效果,现报告如下: 相似文献
49.
Two samples of kindergarten children's representation and understanding of written number symbols were examined in two time points in one academic year. About 85% of Chinese five year olds (mean = 5 years 10 months) were able to use conventional number symbols to represent the quantity of 30 or larger. At the end of the kindergarten year, 94% of Chinese six year olds (mean = 6 years 4 months) were able to use conventional number symbols to represent the quantity of 100 or larger. Some Chinese six year olds had problems in representing written addition and subtraction tasks. Children's ability to represent written number symbols, ability to represent written addition and subtraction formula and their performance on written addition and subtraction were closely related. The performance of children in a university-affiliated childcare center was better than that of the center serving working-class families in Time 1, but the performance reversed at the end of the kindergarten year. 相似文献
50.
Tumor metastasis to the pancreas is a rare but recognized cause of acute pancreatitis. Autopsy series have reported a 24-40% of pancreatic involvement in small cell lung cancer. However, only a very few cases of tumor-induced acute pancreatitis have been described. Budd-Chiari syndrome complicating lung cancer is a rarely reported condition. We report a 68-year-old woman with extensive small cell lung cancer with the unusual initial presentation of both acute pancreatitis and acute Budd-Chiari syndrome. This patient suffered from progressive epigastralgia for 3 weeks. Severe epigastralgia with radiation to back and progressive jaundice developed 2 days prior to admission. After admission, the liver enlarged rapidly and the ascites increased markedly. Chest roentgenogram showed a mass lesion over the left lower lung field. Poorly differentiated carcinoma cells were found in ascites and bone marrow. The patient died on the ninth day of hospitalization before chemotherapy was initiated. Prompt diagnosis of extensive-stage small cell lung cancer may allow early chemotherapy treatment which favorably influences recovery when the pancreatitis is mild. Although prolonged survival might have been expected had this patient recovered from pancreatitis and received chemotherapy, diagnosis was delayed due to difficulty in immunohistochemical diagnosis of the tumor and the unusual clinical presentation. The use of stains employing antibodies against neurofilament and neuron-specific enolase cell antigens is important for early diagnosis of poorly differentiated metastatic tumor cells. 相似文献