全文获取类型
收费全文 | 55643篇 |
免费 | 5009篇 |
国内免费 | 3136篇 |
专业分类
耳鼻咽喉 | 856篇 |
儿科学 | 686篇 |
妇产科学 | 618篇 |
基础医学 | 7473篇 |
口腔科学 | 1077篇 |
临床医学 | 6661篇 |
内科学 | 9260篇 |
皮肤病学 | 817篇 |
神经病学 | 3328篇 |
特种医学 | 2734篇 |
外国民族医学 | 21篇 |
外科学 | 6061篇 |
综合类 | 6299篇 |
现状与发展 | 13篇 |
一般理论 | 5篇 |
预防医学 | 3226篇 |
眼科学 | 1315篇 |
药学 | 5653篇 |
41篇 | |
中国医学 | 2481篇 |
肿瘤学 | 5163篇 |
出版年
2024年 | 179篇 |
2023年 | 894篇 |
2022年 | 2203篇 |
2021年 | 3082篇 |
2020年 | 2220篇 |
2019年 | 2046篇 |
2018年 | 2071篇 |
2017年 | 1863篇 |
2016年 | 1846篇 |
2015年 | 2677篇 |
2014年 | 3099篇 |
2013年 | 2999篇 |
2012年 | 4302篇 |
2011年 | 4561篇 |
2010年 | 2814篇 |
2009年 | 2239篇 |
2008年 | 2976篇 |
2007年 | 2904篇 |
2006年 | 2708篇 |
2005年 | 2551篇 |
2004年 | 1880篇 |
2003年 | 1721篇 |
2002年 | 1435篇 |
2001年 | 1141篇 |
2000年 | 1126篇 |
1999年 | 1147篇 |
1998年 | 624篇 |
1997年 | 603篇 |
1996年 | 474篇 |
1995年 | 426篇 |
1994年 | 384篇 |
1993年 | 219篇 |
1992年 | 372篇 |
1991年 | 285篇 |
1990年 | 276篇 |
1989年 | 246篇 |
1988年 | 221篇 |
1987年 | 193篇 |
1986年 | 161篇 |
1985年 | 121篇 |
1984年 | 81篇 |
1983年 | 67篇 |
1982年 | 26篇 |
1981年 | 35篇 |
1980年 | 22篇 |
1979年 | 37篇 |
1978年 | 21篇 |
1977年 | 22篇 |
1976年 | 32篇 |
1974年 | 25篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
X F Sun H Zhang X C Wu Y M Han G Q Hou M S Xian 《Acta oncologica (Stockholm, Sweden)》1992,31(1):37-40
The microcirculatory architecture of normal tissue, transitional mucosa and adenocarcinoma of the human colon was investigated with microvascular corrosion casting (MVCC) combined with scanning electron microscopy (SEM). The study showed that the capillaries within the normal mucosa were arranged in a regular hexagonal pattern around the mucosal glands and that the microvessels of transitional mucosa mostly had lost the typical hexagonal pattern and become slightly wider in diameter. The microvessels in the tumor periphery were increased in number and disorganized, and presented large variation in morphology with claw-like formations, widened sinuses, diverticula and appendixoid patterns. Microvessels were lacking in the central areas of tumors. These morphological alterations may serve as additional indicators of tumor development. 相似文献
12.
13.
A case of a paraffinoma in the urinary bladder is presented. Plain radiography and intravenous urography showed a low attenuation filling defect in the urinary bladder, and CT demonstrated a lobulated fat-attenuation mass floating in the urinary bladder. 相似文献
14.
Sonographic findings in 16 cases of Krukenberg tumor from gastric carcinoma were analyzed. The patients' ages ranged from 25 to 52 years (mean 42 years). The tumor involved both ovaries in 14 patients with asymmetrical masses in 9 of 14 cases. Ascites was noted in 15 cases. Echogenicity of the tumor varied from solid to predominantly cystic: solid in 8, mixed in 6, and predominantly cystic in 2 cases. Solid masses tended to be smaller than mixed or cystic masses. The primary gastric carcinoma had been diagnosed before emergence of the tumors in only 7 cases. The findings suggest that in relatively young patients with ovarian mass, particularly bilateral tumors, careful evaluation for gastrointestinal tract involvement should be done. 相似文献
15.
Kyung‐Sub Moon Shin Jung Jae‐Hyuk Lee Tae‐Young Jung In‐Young Kim Soo‐Han Kim Sam‐Suk Kang 《Neuropathology》2006,26(2):141-146
We present a case of benign osteoblastoma of the occipital bone. Benign osteoblastoma is an uncommon primary bone tumor, which usually involves the vertebrae and the long bones. This tumor rarely develops in the calvaria, showing a preference for the temporal and frontal bones when it does. To the best of our knowledge, this case is only the eighth reported case of benign osteoblastoma confined to the occipital bone. A 20‐year‐old male presented with a mild tender mass lesion of the occipital area, just below the lambda. Plain X‐ray films and CT scans demonstrated an osteolytic mass surrounded by the sclerotic rim within the diploic space. MRI proved to be effective for the evaluation of the intracranial and intraosseous extensions of the tumor. However, it was very difficult to formulate a differential diagnosis against other osteoblastic tumors, or osteoid osteoma, in view of its radiological appearance. The final diagnosis was obtained by careful consideration of the histopathological characteristics of the tumor combined with its clinical and radiological features. Although generally regarded as benign, a complete resection is preferred over conventional curettage as this can guard against possible recurrence and malignant transformation. 相似文献
16.
17.
Y.W. Chung D.S. Han Y.K. Park B.K. Son C.H. Paik Y.C. Jeon J.H. Sohn 《Digestive and liver disease》2006,38(7):515-517
A diospyrobezoar is a type of phytobezoar that is considered to be harder than any other types of phytobezoars. Here, we describe a new treatment modality, which effectively and easily disrupted huge gastric diospyrobezoars. A 41-year-old man with a history of diabetes mellitus was admitted with lower abdominal pain and vomiting. Upper gastrointestinal endoscopy revealed three huge, round diospyrobezoars in the stomach. He was made to drink two cans of Coca-Cola every 6 h. At endoscopy the next day, the bezoars were partially dissolved and turned to be softened. We performed direct endoscopic injection of Coca-Cola into each bezoar. At repeated endoscopy the next day, the bezoars were completely dissolved. 相似文献
18.
Previous findings from this laboratory with the intracerebral microinjection technique suggested that the periaqueductal gray (PAG), nucleus accumbens, and habenula might constitute a unidirectional loop to play their roles in pain modulation. In the present study we demonstrate that intra-habenular injection of naloxone antagonizes the analgesia elicited by morphine injected into the periaqueductal gray (PAG) and that intra-accumbens injection of naloxone is capable of attenuating the analgesic effects of morphine injected into the habenula. These results indicate that the relationships between these nuclei may be more complex than the putative unidirectional loop. 相似文献
19.
Effects of sodium salts of various monovalent inorganic anions on transdermal permeation of salicylic acid were investigated. In in-vitro experiment using a Franz-type diffusion cell and excised mouse skin, the permeation-enhancing activities of the sodium salts of inorganic anions were roughly proportional to lyotropic Hofmeister swelling abilities of the anions; F?<SO4 2?<Cl? <ClO4 ?<NO3 <SCN? <Br <I?, i.e. l, Br and SCN increased the flux of drugs through the mouse skin, while F?, SO4 2?, Cl?, ClO4 ? and NO3 ? decreased or did not affect the flux. In invivo experiment using the rabbit as the test animal, the plasma concentration of salicylic acid of the rabbit to which 10%-salicylic acid ointment containing 5%-Nal or NaBr was applied was significantly higher than that of the rabbit to which the ointment without the electrolytes was applied. The amounts of sterol leached out of stratum corneum sheet when the sheet was immersed in aqueous solutions of Nal, NaBr, or NaSCN were much more than that of stratum corneum immersed in aqueous solutions of the other inorganic anions. The FTIR/ATR spectroscopy showed that the peaks at 2853 cm?1 and 2924 cm?1 in the IR absorption spectrum of the stratum corneum sheet of the mouse were shifted to higher frequencies by the anions which enhanced the transdermal drug permeation, while not shifted by the anions which did not have any permeation-enhancing activities or have permeation-reducing activities. These results suggest that sodium salts of some anions such as iodide, bromide and thiocyanate enhance transdermal permeation of salicylic acid through swelling and perturbation of the skin structure by these anions. 相似文献
20.