全文获取类型
收费全文 | 35951篇 |
免费 | 1632篇 |
国内免费 | 152篇 |
专业分类
耳鼻咽喉 | 270篇 |
儿科学 | 553篇 |
妇产科学 | 429篇 |
基础医学 | 4806篇 |
口腔科学 | 1054篇 |
临床医学 | 2430篇 |
内科学 | 9062篇 |
皮肤病学 | 795篇 |
神经病学 | 2657篇 |
特种医学 | 1347篇 |
外科学 | 5971篇 |
综合类 | 158篇 |
一般理论 | 1篇 |
预防医学 | 1199篇 |
眼科学 | 628篇 |
药学 | 2438篇 |
中国医学 | 76篇 |
肿瘤学 | 3861篇 |
出版年
2023年 | 158篇 |
2022年 | 350篇 |
2021年 | 627篇 |
2020年 | 308篇 |
2019年 | 429篇 |
2018年 | 590篇 |
2017年 | 458篇 |
2016年 | 574篇 |
2015年 | 555篇 |
2014年 | 760篇 |
2013年 | 939篇 |
2012年 | 1514篇 |
2011年 | 1713篇 |
2010年 | 911篇 |
2009年 | 865篇 |
2008年 | 1518篇 |
2007年 | 1655篇 |
2006年 | 1682篇 |
2005年 | 1687篇 |
2004年 | 1583篇 |
2003年 | 1663篇 |
2002年 | 1756篇 |
2001年 | 1465篇 |
2000年 | 1472篇 |
1999年 | 1277篇 |
1998年 | 491篇 |
1997年 | 361篇 |
1996年 | 330篇 |
1995年 | 286篇 |
1994年 | 254篇 |
1993年 | 251篇 |
1992年 | 921篇 |
1991年 | 820篇 |
1990年 | 737篇 |
1989年 | 755篇 |
1988年 | 682篇 |
1987年 | 701篇 |
1986年 | 608篇 |
1985年 | 574篇 |
1984年 | 374篇 |
1983年 | 316篇 |
1982年 | 162篇 |
1981年 | 154篇 |
1979年 | 246篇 |
1978年 | 183篇 |
1977年 | 155篇 |
1974年 | 159篇 |
1973年 | 174篇 |
1969年 | 155篇 |
1967年 | 158篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
82.
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
83.
H Shiozaki T Ide J Nakao T Imamura M Nakamura K Shimada Y Miura T Suda 《Japanese journal of cancer research》1992,83(5):499-504
LD78 is a cDNA newly isolated from human stimulated tonsillar lymphocytes. The expression of LD78 is related to inflammatory responses and its structure has a homology with macrophage inflammatory protein 1-alpha, which is known to have an inhibitory effect on murine CFU-S. Using a colony assay technique, we examined the effects of LD78 on human hemopoietic progenitors. The addition of doses of 100 ng/ml or more of LD78 suppressed the colony formation of KMT-2, a factor-dependent myelomonocytic cell line established from cord blood cells; this suppressive activity was neutralized by the addition of antibody against LD78. The same doses of LD78 suppressed the formation of neutrophil, macrophage, and megakaryocytic colonies which were supported by human interleukin-3 and erythropoietin; however, LD78 did not affect colony formation by either non-phagocytic mononuclear cells or sorted CD34+ cells. The conditioned medium of KMT-2 cells or peripheral blood mononuclear cells cultured with LD78 suppressed colony formation by CD34+ cells. From these findings, it is suggested that LD78 affects phagocytic cells and induces factors that are inhibitory for hemopoiesis. We consider LD78 to be a new cytokine that plays an inhibitory role in hemopoiesis. 相似文献
84.
Koichiroh Nandate Kenji Muranaka Koichi Shinohara Kazuyoshi Ishida Hiroko Ishida Katsuhiro Seo Hiroshi Takeshita 《Journal of anesthesia》1997,11(2):117-120
We retrospectively reviewed the records of 250 consecutive patients undergoing coronary artery bypass graft surgery (CABG)
from January 1994 through January 1996 to determine the incidence of persistent postoperative neurological dysfunction after
CABG and to compare normothermic and moderate hypothermic cardiopulmonary bypass (CPB). Normothermic CPB was used in 128 patients
(36°–37°C) and hypothermic CPB (27°–28°C) in 122 patients. Postoperative neurological dysfunction included focal motor deficits,
delayed recovery of consciousness (>24h) after surgery, and seizures within 1 week postoperatively. Persistent neurological
dysfunction was diagnosed if complete resolution had not occurred within 10 days of surgery. The incidence of persistent postoperative
neurological dysfunction was 4.1% in the hypothermic CPB group and 2.3% in the normothermic CPB group. There were no statistically
significant differences between the two groups (P=NS). These results suggest that normothermic CPB did not increase the incidence of persistent postoperative neurological
dysfunction compared to hypothermic CPB. 相似文献
85.
Makoto Watanabe Takashi Fujimoto Masayuki Iwano Hideo Shiiki Shinobu Nakamura 《Nihon Rinshō Men'eki Gakkai kaishi》2002,25(2):191-198
We describe the case of a 61-year-old woman diagnosed with primary Sj?gren's syndrome (SS) after an 8-year history of IgA nephropathy and a 3-year history of recurrent purpuric rashes. Her two daughters had previously been diagnosed with other autoimmune diseases. One daughter had Graves' disease and the other had Hashimoto's disease and systemic lupus erythematosus. The diagnosis of SS was made based on dryness of mucous membranes, Shirmer test, and parotid sialography. Thrombocytopenia, high platelet-aggregated IgG (PA-IgG) level, and normal megakaryocytes count in bone marrow suggested that her recurrent purpuric rashes were due to idiopathic thrombocytopenic purpura (ITP). Patients with SS may develop other autoimmune diseases. This case aids understanding of the immune pathogenesis and genetic background of SS. 相似文献
86.
Mariko Hosono H. Kobayashi Ryota Fujimoto Kazushige Tsutsui Yoshihiko Kotoura Tadao Tsuboyama Hikaru Hayashi Takashi Nakamura Junji Konishi 《Skeletal radiology》1997,26(9):525-528
Objective. To clarify the MRI features of parasymphyseal insufficiency fractures of the os pubis. Design and patients. MRI was performed in four postmenopausal women with parasymphyseal insufficiency fractures. The diagnosis was confirmed with
plain films in every patient. T1-weighted and T2-weighted images were obtained in four patients using a 1.5-T unit. Postcontrast
T1-weighted imaging was also done in three patients. Results and conclusions. MRI of pubic parasymphyseal insufficiency fracture characteristically demonstrates a hyperintense mass lesion with a hypointense
rim on T2-weighted imaging, showing peripheral and septal enhancement after contrast administration. It is important to have
this entity in mind in patients with osteoporosis, especially in patients with a history of pelvic irradiation for malignant
disease, so as not to misinterpret it as a chondroid tumor or bone metastasis. 相似文献
87.
M Teramachi N Miyamoto T Sasaka T Nakamura F Kitamura 《Nihon Kyōbu Shikkan Gakkai zasshi》1991,29(7):909-912
A 68-year-old woman was admitted with cough and dyspnea. Her chest X-ray showed right pleural effusion and a mediastinal tumor. She underwent mediastinotomy following a preoperative diagnosis of invasive thymoma. A tumor originating from the thymus had invaded the right middle lobe and pericardium, and multiple pleural dissemination was also found. Therefore, considering the patient's age and pulmonary function, we performed only subtotal resection of the tumor. The pathological diagnosis was poorly differentiated squamous cell carcinoma. The patient received irradiation and chemotherapy including Cisplatin after surgery, but she died 1 year later because of rapid progression of distant metastases. 相似文献
88.
K Nishi M Yamada D Morishita Y Nakamura Y Murata M Fujioka S Muramoto S Murakami K Sasaki M Yasui 《Nihon Kyōbu Shikkan Gakkai zasshi》1991,29(7):904-908
A rare case of a 25-year-old man with pulmonary aspergillosis is reported. Pulmonary bulla and eosinophilic pneumonia in the right upper lobe were diagnosed by chest roentgenogram and transbronchial lung biopsy. Because the patient developed infective bullae during steroid therapy, we performed transcutaneous thoracic drainage and right upper lobectomy. The resected lung tissue contained numerous hyphae of Aspergillus. Around the hyphae of Aspergillus, granulomatous reaction and eosinophilic infiltration were observed. Antibodies against Aspergillus were detected in the serum of the patient. The number of peripheral blood eosinophils decreased after right upper lobectomy. These findings suggest that pulmonary bullae and eosinophilic pneumonia may be a rare manifestation of pulmonary aspergillosis. 相似文献
89.
N Nakamura S Suzuki N Ono K Tominaga H Hojo M Abe H Wakasa 《Hematological oncology》1992,10(2):95-104
We reported a new monoclonal antibody, designated FUB-1, reacting with normal and neoplastic large lymphoid cells. FUB-1 was produced using a Burkitt's lymphoma cell line (HBL-5) as an immunogen. Its immunoglobulin subtype was IgM. The determinant was not on the surface but in the cytoplasm. Western blotting analysis revealed that the molecular weight of the antigen was 52,000 dalton. In the normal lymphoid tissue, FUB-1 reacted with large lymphoid cells, but not with small or medium-sized lymphoid cells or plasma cells. In addition, the FUB-1 antigen was not found in resting cells in the peripheral blood (PB), but it was induced on mononuclear cells of PB by addition of PWM or PMA. In the B-cell lymphomas tested, FUB-1 reacted with small cleaved cell lymphomas (3/12), large cell lymphomas (7/10), Burkitt's lymphomas (4/4) and immunoblastic lymphomas (2/2), but not with small cell lymphomas (0/3) or intermediate lymphocytic lymphomas (0/8). These findings indicate that the FUB-1 antigen appears to be expressed on normal lymphoid cells during blastoid transformation and on neoplastic large lymphoid cells. FUB-1 also reacted with normal glandular epithelium and various adenocarcinomas. FUB-1 may be useful to investigate the mechanism of in vitro blastoid transformation or activation of lymphoid cells. 相似文献
90.
Extracardiac Direct Total Cavopulmonary Connection 总被引:2,自引:0,他引:2
Masaaki Yamagishi MD Yuzuru Nakamura MD Toshiyuki Kanazawa MD Noriyasu Kawada MD 《The Annals of thoracic surgery》1997,64(6):1817-1819
We report a successful extracardiac direct total cavopulmonary connection without prosthetic materials performed in a 3-year-old boy with tricuspid atresia, infundibular pulmonary stenosis, and normally positioned great arteries. The transected pulmonary trunk was bought down posterolaterally with respect to the right atrium and was anastomosed end-to-end with the inferior vena cava. 相似文献