全文获取类型
收费全文 | 31682篇 |
免费 | 1575篇 |
国内免费 | 158篇 |
专业分类
耳鼻咽喉 | 467篇 |
儿科学 | 571篇 |
妇产科学 | 342篇 |
基础医学 | 4276篇 |
口腔科学 | 812篇 |
临床医学 | 2108篇 |
内科学 | 7970篇 |
皮肤病学 | 789篇 |
神经病学 | 2048篇 |
特种医学 | 1285篇 |
外国民族医学 | 1篇 |
外科学 | 5318篇 |
综合类 | 170篇 |
一般理论 | 2篇 |
预防医学 | 882篇 |
眼科学 | 401篇 |
药学 | 2361篇 |
中国医学 | 108篇 |
肿瘤学 | 3504篇 |
出版年
2023年 | 165篇 |
2022年 | 350篇 |
2021年 | 556篇 |
2020年 | 329篇 |
2019年 | 435篇 |
2018年 | 520篇 |
2017年 | 455篇 |
2016年 | 552篇 |
2015年 | 537篇 |
2014年 | 762篇 |
2013年 | 901篇 |
2012年 | 1464篇 |
2011年 | 1581篇 |
2010年 | 890篇 |
2009年 | 858篇 |
2008年 | 1426篇 |
2007年 | 1630篇 |
2006年 | 1538篇 |
2005年 | 1639篇 |
2004年 | 1554篇 |
2003年 | 1404篇 |
2002年 | 1374篇 |
2001年 | 1076篇 |
2000年 | 1009篇 |
1999年 | 979篇 |
1998年 | 399篇 |
1997年 | 282篇 |
1996年 | 323篇 |
1995年 | 243篇 |
1994年 | 195篇 |
1993年 | 228篇 |
1992年 | 656篇 |
1991年 | 566篇 |
1990年 | 554篇 |
1989年 | 562篇 |
1988年 | 535篇 |
1987年 | 495篇 |
1986年 | 472篇 |
1985年 | 437篇 |
1984年 | 329篇 |
1983年 | 264篇 |
1982年 | 168篇 |
1979年 | 248篇 |
1977年 | 188篇 |
1973年 | 178篇 |
1972年 | 188篇 |
1971年 | 190篇 |
1970年 | 173篇 |
1969年 | 189篇 |
1968年 | 173篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
71.
72.
73.
M. Ito T. F. Lang M. Jergas M. Ohki M. Takada T. Nakamura K. Hayashi H. K. Genant 《Calcified tissue international》1997,61(2):123-128
This study examined trabecular bone mineral density (BMD) in Japanese women with and without spinal fracture, and compared
the results to American women with and without fracture. The quantitative computed tomography (QCT) systems used at the University
of California, San Francisco (UCSF) and at Nagasaki University were cross-calibrated. Normative BMD was assessed with the
K2HPO4 liquid phantom in 538 Americans aged 20–85 years, and with the B-MAS200 phantom in 577 Japanese aged 20–83 years. These BMD
were adjusted for use with the Image Analysis solid phantom using the result of cross-calibration. The trabecular BMD in 111
postmenopausal American women (55 with fracture), and in 185 postmenopausal Japanese women (67 with fracture) were compared
for investigation of the difference in BMD values relative to fracture status. The absolute BMD values in Japanese were lower
than those in Americans, and the differences were greater with advancing age. The magnitude of the BMD difference was 8.6,
20.5, 38.1 mg/cm3 in women aged 20–24 years, 40–44 years, 60–64 years, respectively. In premenopausal women, BMD began to decrease at the age
of 20 in Japanese, whereas the peak bone mass was maintained until the age of 35 in the American women. In immediate postmenopausal
women, BMD significantly decreased in both populations. In later postmenopausal women, BMD significantly decreased with age
in the Japanese women but decreased less rapidly in the American women. The aging decrease of BMD was 1.4% and 2.2% per year
in the later postmenopausal American and Japanese women, respectively. The fracture threshold is considered to be lower in
Japanese women. However, the BMD difference between American and Japanese women with fracture was similar to that without
fracture. The Z-scores of fracture subjects versus controls were 2.9 in American and 1.8 in Japanese women. In conclusion,
Japanese women were found to have a lower BMD and lower fracture threshold than American women. The significant decrease of
spinal trabecular BMD in late postmenopause is potentially responsible for the higher prevalence of spinal fracture in Japanese
women.
Received: 18 December 1995 / Accepted: 23 September 1996 相似文献
74.
A case of a bilateral pulmonary hernia of the lungs into the supraclavicular fossae is described. A man, aged 79, with severe chronic asthma and chronic bronchitis due to air pollution, complained of a cervical mass off and on for several years. The herniation was greater on the right side. It could be identified on physical examination by the presence of a soft painless supraclavicular bulge which was exaggerated by strain or cough. Radiologically this herniation could best be identified on lateral cervical roentgenogram. It is said that cervical lung hernia is a rare condition, but in our experience supraclavicular herniation of the lung is not unusual in cases of severe chronic obstructive lung disease. 相似文献
75.
We have prepared a new material for embolisation: ethylene vinylacetate copolymer dissolved in polyvinyl alcohol. When in contact with blood, polyvinyl alcohol rapidly becomes a soft gel, which is accompanied by wedging of the ethylene vinylacetate copolymer. We analysed the histopathology of intra-arterial microemboli in rats, after intracarotid injection of this material. We confirmed that it was applicable to embolisation for neurosurgical treatment. 相似文献
76.
H J Jeon T Akagi Y Hoshida K Hayashi T Yoshino T Tanaka J Ito T Kamei K Kawabata 《Cancer》1992,70(10):2451-2459
BACKGROUND. The breast is rarely a primary site for extranodal malignant lymphoma. Most reported primary non-Hodgkin malignant lymphomas of the breast (PBL) are of B-cell phenotype. METHODS. Histologic and immunohistochemical analyses of seven patients with PBL and a statistical analysis of 152 patients with PBL reported in the Japanese literature were performed. RESULTS. Malignant lymphoma could not be predicted preoperatively with clinical and radiologic findings; breast carcinoma, fibroadenoma, and phyllodes tumor were the preoperative diagnoses. All patients were women; they ranged in age from 31 to 80 years (mean, 57.6 years). The right breast was involved initially in five patients. In four, only the breast was involved (Stage I), whereas in three, the ipsilateral axillary lymph nodes (Stage II) were involved at diagnosis. According to the Working Formulation, all patients belonged to the intermediate grade and were classified as having diffuse large cell (five patients) or mixed (two patients) lymphoma. Immunophenotypic analysis revealed that all patients had B-cell lymphoma. No patients had lymphoepithelial lesions, which is the characteristic feature in categorizing a lymphoma as a mucosa-associated lymphoid tissue (MALT) lymphoma. A statistical analysis of the patient reported in the Japanese literature has divided PBL into two types: a bilateral type that affects younger women and a unilateral type that has a broad age distribution, but preponderantly occurs in older women. The age and stage at diagnosis were significant prognostic factors in predicting the survival time, but the location and size of the tumor at initial presentation, histopathologic type, terminal leukemic manifestation, and treatment modality were not. CONCLUSIONS. This study indicates that most PBL are diffuse large cell lymphoma of B-cell phenotype and that the age and stage at diagnosis are significant prognostic factors. 相似文献
77.
Based upon detailed dissections of the lymphatic system in adult cadavers, the lymphatic drainage of the gallbladder was divided
into three pathways: (1) The cholecystoretropancreatic pathway, which had two routes, one running spirally from the anterior
surface of the common bile duct to the right rear, and the other running almost straight down from the posterior surface of
the common bile duct. These routes converged at the principal retroportal node at the posterior surface of the head of the
pancreas. (2) The cholecysto-celiac pathway; this was the route running to the left through the hepatoduodenal ligament to
reach the celiac nodes. (3) The cholecysto-mesenteric pathway; this was the route running to the left in front of the portal
vein to connect with the nodes at the superior mesenteric root. The cholecysto-retropancreatic pathway can be regarded as
the main pathway, and the principal retroportal node appeared to be critical as the main terminal node in the visceral lymphatic
system of the gallbladder. These three pathways converged with the abdomino-aortic lymph nodes near the left renal vein, and
the nodes in the interaortico-caval space were considered to be of particular importance.
Offprint requests to: M. Ito 相似文献
78.
79.
Seiya Kikuchi Akira Ingu Masayoshi Ito 《Annals of thoracic and cardiovascular surgery》2005,11(5):320-323
We report an 18-month-old boy with the association of pectus excavatum and tetralogy of Fallot (TOF). We successfully performed simultaneous pectus repair using sternal elevation without any prosthetic support and total correction of TOF after a prior modified Blalock-Taussig shunt. Retracting a divided costo-sternal complex with a rectus abdominal flap away from the operative field before the cardiac operation provided excellent surgical exposure. The modified Blalock-Taussig shunt prior to the combined repair prevented life-threatening hypoxic spells during dissection of the deformed sternum and costochondral cartilages before institution of cardiopulmonary bypass. 相似文献
80.
Shinichi Suzuki Kiyotaka Imoto Keiji Uchida Naoki Hashiyama Yoshinori Takanashi 《Annals of thoracic and cardiovascular surgery》2005,11(6):424-428
This report describes the use of transluminal endovascular grafting for the treatment of a presumed aortoduodenal fistula. The patient was a 71-year-old man who had undergone resection and graft replacement for an abdominal aortic aneurysm. Three years after operation, melena was caused by perforation of the duodenal wall by a pseudoaneurysm at the proximal graft anastomosis. The pseudoaneurysm was treated by transluminal endovascular grafting. The pseudoaneurysm was subsequently thrombosed and absorbed. The ulcer-like lesions at the site of the duodenal wall perforated by the pseudoaneurysm also resolved. Endovascular stent-grafts may have a role to play in management of aortoduodenal fistula. 相似文献