全文获取类型
收费全文 | 150914篇 |
免费 | 8940篇 |
国内免费 | 1415篇 |
专业分类
耳鼻咽喉 | 2368篇 |
儿科学 | 2363篇 |
妇产科学 | 2508篇 |
基础医学 | 23541篇 |
口腔科学 | 3462篇 |
临床医学 | 13972篇 |
内科学 | 28002篇 |
皮肤病学 | 4538篇 |
神经病学 | 12033篇 |
特种医学 | 8306篇 |
外科学 | 19984篇 |
综合类 | 1046篇 |
现状与发展 | 3篇 |
一般理论 | 42篇 |
预防医学 | 7856篇 |
眼科学 | 3956篇 |
药学 | 13519篇 |
中国医学 | 1627篇 |
肿瘤学 | 12143篇 |
出版年
2023年 | 1078篇 |
2022年 | 3103篇 |
2021年 | 5086篇 |
2020年 | 2463篇 |
2019年 | 3530篇 |
2018年 | 4366篇 |
2017年 | 3465篇 |
2016年 | 4497篇 |
2015年 | 6183篇 |
2014年 | 7366篇 |
2013年 | 8649篇 |
2012年 | 12898篇 |
2011年 | 12506篇 |
2010年 | 7151篇 |
2009年 | 6191篇 |
2008年 | 8858篇 |
2007年 | 8439篇 |
2006年 | 7609篇 |
2005年 | 7137篇 |
2004年 | 6231篇 |
2003年 | 5571篇 |
2002年 | 4831篇 |
2001年 | 3780篇 |
2000年 | 3454篇 |
1999年 | 2772篇 |
1998年 | 1128篇 |
1997年 | 874篇 |
1996年 | 702篇 |
1995年 | 616篇 |
1994年 | 530篇 |
1993年 | 429篇 |
1992年 | 1046篇 |
1991年 | 921篇 |
1990年 | 897篇 |
1989年 | 814篇 |
1988年 | 704篇 |
1987年 | 668篇 |
1986年 | 511篇 |
1985年 | 532篇 |
1984年 | 400篇 |
1983年 | 303篇 |
1982年 | 212篇 |
1981年 | 235篇 |
1980年 | 196篇 |
1979年 | 348篇 |
1978年 | 244篇 |
1977年 | 186篇 |
1976年 | 179篇 |
1975年 | 183篇 |
1974年 | 192篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
A case of spontaneous thrombosis and infarction leading to death as complications of a cerebral venous malformation in a 13-yearold boy is reported. This is the first published report of this type of complication occurring in a case of venous angioma. While the biologic behavior of cerebral venous malformations has suggested that they are benign in nature, and the results of surgical management have encouraged a conservative approach, the present case illustrates a potential complication and argues against the assumption that these malformations are completely benign in nature. 相似文献
82.
BACKGROUND AND PURPOSE: The Doppler waveform patterns of loss of diastolic flow, appearance of retrograde diastolic flow, or no detectable flow in the cerebral arteries suggest significantly abnormal cerebral blood flow (CBF). A retrospective study was performed to show that significantly abnormal CBF alone, without clinical criteria, is not necessarily specific to brain death in the young pediatric population. PATIENTS AND METHODS: Forty-seven pediatric patients, from newborn to 4 years of age, were found to have significantly abnormal CBF, including 7 patients with loss of diastolic flow, 28 with retrograde diastolic flow, and 23 with no detectable cerebral flow on serial Doppler sonographic examinations. Their clinical data and sonographic results were collected and analyzed. RESULTS: Forty-two patients died, a few of whom had only transient improvement of cerebral flow. All of the patients with no detectable cerebral flow expired. Five patients survived with or without sequelae. Their underlying conditions that caused increased intracranial pressure were treated by medical and/or surgical intervention, and diastolic reversal of CBF corrected within 1 day in all 5. CONCLUSIONS: Although no detectable flow is a lethal sign, pediatric patients with loss or reversal of diastolic flow may survive with prompt and effective treatment. Using Doppler ultrasound to diagnose cerebral circulatory arrest should be done with caution in pediatric patients. 相似文献
83.
It is often difficult to make a clinical or histologic diagnosis of erythrodermic mycosis fungoides (MF) and Sézary syndrome (SS). Whereas the histologic parameters for making a diagnosis of MF with well-developed patch and plaque stage lesions are clearly defined, the same criteria appear to be less relevant for diagnosing MF in patients with erythroderma secondary to the disease. In order to better define the histologic features of erythrodermic MF and SS, we studied 28 routine histologic sections of 17 patients with known erythrodermic MF or SS. Sections were reviewed independently by 2 dermatopathologists. Each of 24 parameters was scored semi-quantitatively and the data were compared to data previously reported from a group of 64 patients with limited patch and plaque stage lesions of MF. When compared to biopsies from patients with limited patch/plaque lesions, biopsies taken from erythrodermic patients displayed more parakeratosis (p=0.0492) and acanthosis (p=0.0046), less disproportionate epidermotropism, fewer lymphocytes aligned within the basal layer (p=0.0045), fewer hyper-convoluted cells in the epidermis, more dermal hyperconvoluted cells (p=0.0191), more papillary dermal fibrosis (p=0.0002), more prominent teleangiectasias (p=0.0028) and more mitotic figures.
The histologic features of erythrodermic MF and Sézary syndrome are even more subtle than the features of patch and plaque stage MF, thus rendering the histologic diagnosis more difficult. 相似文献
The histologic features of erythrodermic MF and Sézary syndrome are even more subtle than the features of patch and plaque stage MF, thus rendering the histologic diagnosis more difficult. 相似文献
84.
Hyun-Min Shin Chul-Jong Park Jong-Yuk Yi Tae-Yoon Kim Chung-Won Kim 《Pediatric dermatology》1996,13(2):146-147
Abstract: Juvenile xanthogranuloma is a xanthomatous and granulomatous condition that frequently arises before 1 year of age and mainly occurs on the head and trunk. We report a rare solitary juvenile xanthogranuloma on the right palm of a 10-year-old girl, present for one year. This solitary involvement of the palm has been reported only twice before. 相似文献
85.
W. S. Hong Y. I. Min H. T. Kim Y. B. Cho K. H. Kim D. K. Kim 《Journal of Korean medical science》1995,10(4):269-274
In an attempt to develop a new anticancer platinum complex with greater or equivalent antitumor activity but reduced side effects compared with cisplatin (CDDP), a series of new platinum complexes having a glycolate leaving ligand was synthesized. Among them, five complexes were selected for further development on the basis of adequate water solubility, low nephrotoxicity and high antitumor activity in a murine system. The chemosensitivity of these five complexes was examined in MTT assay against two human pulmonary adenocarcinoma cell lines, PC-9 and PC-14, and two human stomach adenocarcinoma cell lines, MKN-45 and KATO III. Their IC50 and relative antitumor activity (RAA) values were compared with those of CDDP and 254-S, a second-generation platinum complex with a glycolate leaving ligand under phase III clinical trial. The lowest mean IC50 value was observed in CDDP, followed by SKI 2034R and SKI 2033R. In this study, the antitumor activity was evaluated in terms of RAA values and SKI 2034R showed the highest RAA value. The order of RAA values was SKI 2034R > CDDP > SKI 2032R > SKI 2033R > SKI 2030R > SKI 2029R > 254-S. Based on the RAA order, we have recommended SKI 2034R as the most promising candidate for further development of a clinically useful platinum complex. 相似文献
86.
87.
Tetsuji Kai Yang Il Kim Hirokazu Kitamura Katsunori Kawano Seigo Kitano 《Journal of Hepato-Biliary-Pancreatic Surgery》1997,4(4):423-430
There is a growing body of evidence that the cytokine, tumor necrosis factor-α (TNF-ga), plays an important role in the development
of hepatic ischemia/reperfusion injury. We found that the immunosuppressants, cyclosporine-A (CsA), azathioprine, and FK506,
have protective effects on such injury. The purpose of the present study was to elucidate mechanisms involved in these beneficial
effects of the immunosuppressant, CsA, on liver injury following cold preservation and transplantation, with special reference
to the suppression of TNF-α release. Rat livers were stored in Euro-Collins solution (EC) at 4°C for 6h and orthotopically
transplanted. The animals allotted to two groups: group A (untreated controls) and group B (CsA pretreatment of recipients).
CsA (10 mg/kg, p.o.) was given for 3 consecutive days preoperatively. CsA pretreatment of the recipients significantly improved
the 2-week survival rate (0/6 for group A, 3/6 for group B;P<0.05) and this was associated with a significant decrease in serum TNF-α levels 2h posttransplantation (group A, 69.8±15.7
pg/ml; group B, 22.8±6.8; mean±SEM;n=12 each;P<0.05) and amelioration of sinusoidal endothelial injury, assessed by electron microscopy. Plasma endotoxin levels following
reperfusion of the grafts were not altered by the CsA therapy. Morphologically, CsA pretreatment of the recipients did not
alter activation of Kupffer cells. CsA pretreatment of the recipient aids in preventing cold preservation/reperfusion injury
of the liver graft, possibly by modulating effects of TNF-α. 相似文献
88.
Daniel W. Walsh Vincent B. Ho Michael F. Haggerty 《Journal of magnetic resonance imaging : JMRI》1997,7(2):312-315
Mycotic aneurysms of the abdominal aorta are potentially fatal but uncommon. We report the MRI and MRA features of an abdominal aortic mycotic aneurysm in a patient who presented with nonspecific low back pain. By delineating the saccular nature of the aneurysm and identifying the coexistence of vertebral enhancement, MRI was crucial for the final diagnosis. A potential pitfall of contrast-enhanced MRA is also demonstrated. 相似文献
89.
90.