全文获取类型
收费全文 | 15300篇 |
免费 | 727篇 |
国内免费 | 100篇 |
专业分类
耳鼻咽喉 | 220篇 |
儿科学 | 317篇 |
妇产科学 | 113篇 |
基础医学 | 1650篇 |
口腔科学 | 382篇 |
临床医学 | 999篇 |
内科学 | 4107篇 |
皮肤病学 | 260篇 |
神经病学 | 1257篇 |
特种医学 | 445篇 |
外科学 | 2791篇 |
综合类 | 64篇 |
预防医学 | 454篇 |
眼科学 | 344篇 |
药学 | 1086篇 |
中国医学 | 23篇 |
肿瘤学 | 1615篇 |
出版年
2023年 | 82篇 |
2022年 | 208篇 |
2021年 | 338篇 |
2020年 | 205篇 |
2019年 | 259篇 |
2018年 | 344篇 |
2017年 | 257篇 |
2016年 | 314篇 |
2015年 | 332篇 |
2014年 | 433篇 |
2013年 | 502篇 |
2012年 | 832篇 |
2011年 | 899篇 |
2010年 | 533篇 |
2009年 | 421篇 |
2008年 | 794篇 |
2007年 | 839篇 |
2006年 | 817篇 |
2005年 | 829篇 |
2004年 | 738篇 |
2003年 | 691篇 |
2002年 | 736篇 |
2001年 | 416篇 |
2000年 | 459篇 |
1999年 | 381篇 |
1998年 | 163篇 |
1997年 | 138篇 |
1996年 | 143篇 |
1995年 | 100篇 |
1994年 | 93篇 |
1993年 | 86篇 |
1992年 | 250篇 |
1991年 | 227篇 |
1990年 | 196篇 |
1989年 | 245篇 |
1988年 | 183篇 |
1987年 | 185篇 |
1986年 | 156篇 |
1985年 | 155篇 |
1984年 | 112篇 |
1983年 | 91篇 |
1979年 | 98篇 |
1978年 | 61篇 |
1977年 | 51篇 |
1975年 | 51篇 |
1974年 | 53篇 |
1973年 | 53篇 |
1972年 | 64篇 |
1969年 | 55篇 |
1968年 | 55篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
32.
Toshiharu Mori Nobukazu Okimoto Akinori Sakai Yuichi Okazaki Nariaki Nakura Takuya Notomi Toshitaka Nakamura 《Journal of bone and mineral research》2003,18(11):2002-2009
To investigate the relationship between the effects of bone turnover and bone marrow cell development in bone cells, we developed a mouse voluntary climbing exercise model. Climbing exercise increased bone volume and transient osteogenic potential of bone marrow. This model would be suitable for investigating the mechanistic roles of mechanical loading. INTRODUCTION: The relationship between bone mass gain and local bone formation and resorption in mechanically loaded bone is not well understood. MATERIALS AND METHODS: Sixty-five C57BL/6J mice, 8 weeks of age, were assigned to five groups: a baseline control and two groups each of ground control and climbing exercise mice for 2 and 4 weeks. Mice were housed in a 100-cm tower and had to climb toward a bottle placed at the top to drink water. RESULTS: Compared with the ground control, bone mineral density of the left femur increased in the climbing mice at 4 weeks. At 2 and 4 weeks, bone formation rate (BFR/BS) of periosteal surface, the cross-sectional area, and moment of inertia were increased in the climbing mice, whereas BFR/BS and eroded surface (ES/BS) of endosteal surface did not differ. The trabecular bone volume (BV/TV) of the proximal tibia increased in climbing mice, and osteoclast surface (Oc.S/BS) and osteoclast number decreased at 2 weeks. At 4 weeks, there were increases in BV/TV and parameters of bone formation, including mineralized surface, mineral apposition rate, and bone formation rate. In marrow cell cultures from the tibia, the number of alkaline phosphatase+ colony forming units-fibroblastic and the area of mineralized nodule formation in climbing mice were increased, and the number of osteoclast-like TRACP+ multinucleated cells was lower at 2 weeks. At 4 weeks, these parameters recovered to the levels of the ground controls. CONCLUSION: Our results indicate that climbing increased trabecular bone volume and reduced bone resorption, with a subsequent increase in bone formation. Intermittent climbing downregulates marrow osteoclastogenic cells and upregulates osteogenic cells initially, but further exercise seemed to desensitize them. Cortical envelopes were enlarged earlier, but the response seems to differ from trabecular bone. 相似文献
33.
Y Fujibayashi Y Takemura K Matsumoto K Wada Y Yonekura J Konishi A Yokoyama 《Journal of nuclear medicine》1992,33(4):545-549
In view of the high binding ability of cardiac glycosides to the myocardial Na,K-ATPase, radioiodinated digoxin derivatives were surveyed as candidates for myocardial imaging, with particular emphasis on the noninvasive monitoring of cardiac glycoside therapy. Among the radioiodinated digoxin derivatives surveyed, 125I-digoxin-iodohistamine(bis(O-carboxymethyloxime)) showed the highest accumulation in the myocardium and similar binding ability to Na,K-ATPase as digoxin itself against ouabain displacement, as indicated by in vivo and in vitro studies. Based on these results, 123I labeling of digoxin-histamine(bis(O-carboxymethyloxime)) and imaging in a dog demonstrated uptake in the myocardium. 相似文献
34.
K Iwata H Yoshimura Y Tsuji A Shirai F Uto T Tamada I Yamamoto T Tomiyama T Wada H Ohishi 《International journal of radiation oncology, biology, physics》1992,22(5):1109-1115
For intracavitary high dose-rate radiation therapy, a thermoluminescent [TL] sheet for in vivo measurement of spatial dose distribution around source has been recently developed. The TL sheet was found to have a linear response with a very wide dynamic range from at least 0.002 cGy to 5000 cGy for 60Co gamma-rays. This TL sheet (40 cm x 50 cm x 200 microns), which is composed of Teflon mixed with BaSO4:Eu doped powder, is very flexible and can be cut to the desired size. In addition, this sheet is easy to handle because of its insensitivity to room light. The spatial dose distribution is displayed in a color mode by using a newly developed TL sheet readout system. For a clinical application, the TL sheet was wrapped on an applicator for intracavitary radiation therapy of a rectal cancer and was inserted into the rectum. The location of the TL sheet could be confirmed with diagnostic X ray film. After irradiation with high dose-rate 60Co source, the in vivo relative dose distribution on the surface of the rectum was determined. This TL sheet provided a convenient means of measuring the relative dose distributions around 60Co sources of various patterns in intracavitary radiation therapy. 相似文献
35.
Mitsuru Masaki Tadashi Kuroda Naoki Hosen Hisao Hirota Kazuo Terai Yuichi Oshima Yoshikazu Nakaoka Shoko Sugiyama Ryusuke Kimura Satoshi Yoshihara Manabu Kawakami Norishige Iizuka Yasuhiko Tomita Hiroyasu Ogawa Ichiro Kawase Keiko Yamauchi-Takihara 《Journal of the American Society of Echocardiography》2004,17(4):397-398
A 57-year-old man with a history of renal cell carcinoma presented with presyncope. He underwent nephrectomy years earlier followed by HLA-matched allogeneic peripheral-blood stem-cell transplantation. Echocardiographic investigation revealed a solitary right ventricle mass without contiguous vena caval or right atrial involvement. The mass was pathologically confirmed to be metastatic carcinoma in the right ventricular cavity. This case highlights the need to consider an underlying neoplastic syndrome in patients presenting isolated right ventricle mass by echocardiography. 相似文献
36.
K Wada D Nishi T Kitamura K Ono T Takahara T Shirotani A Shimizu 《Undersea & hyperbaric medicine》2006,33(6):399-405
Moderate hypothermia may have a beneficial effect on the neurological outcome. However, ischemic deterioration such as brain swelling during rewarming has been reported as a notable complication after successful therapeutic cerebral hypothermia. In this study, we investigated the effects of hyperbaric oxygenation during rewarming. Forebrain ischemia was produced in 24 gerbils and sham ischemia in 8 animals. Then ischemia-treated animals were divided into 3 groups, whole-body moderate hypothermia (31 degrees C for 60 min) and hyperbaric oxygenation (HBO2) (2- atmosphere absolute for 60 min using 100% oxygen) during rewarming group (n = 8), moderate hypothermia without HBO2 group (n = 8), and sham treatment without hypothermia and without HBO2 group (n = 8). Both the hypothermia group (77.9 +/- 48.1 neurons per mm, mean +/- SD) and hypothermia + HBO2 group (127.6 +/- 29.7 neurons per mm,) showed significant preservation of CA1 pyramidal neurons in the hippocampus compared to that in the sham treatment group (6.4 +/- 2.7) (p < 0.01). Furthermore, the hypothermia + HBO2 group showed significantly greater preservation of CA1 pyramidal neurons than the hypothermia group (p < 0.05). These results suggest that HBO2 during rewarming preserves the protective effect of hypothermia against ischemic neuronal damage. 相似文献
37.
Naohito Mikuma Hideki Adachi Keiji Takatsuka Akifumi Yokoo Hideki Wada Atsushi Takahashi 《International journal of urology》1996,3(3):243-244
A rare adult case of a left ectopic ureterocele associated with a duplex horseshoe kidney is reported. To the best of our knowledge, only one pediatric case of horseshoe kidney with an ectopic ureterocele has been reported. The present case was successfully treated by ureteropyelostomy, upper ureterectomy and unroofing of the ureterocele. The patient is currently followed with excretory urograms and renograms. 相似文献
38.
W Sakamoto T Kishimoto M Nishisaka H Iimori S Wada R Yasumoto K Yamamoto M Maekawa S Sukano K Umeyama 《Nihon Hinyōkika Gakkai zasshi. The japanese journal of urology》1990,81(2):230-235
We retrospectively reviewed 32 patients who underwent parathyroidectomy at our hospital for the last fourteen years. 1) Clinical appearance of primary hyperparathyroidism was in younger age in women. 2) In previous history or at the time of PTX, 9 patients had malignant tumors including 6 thyroid cancers, 36% of the patients with out bone related symptoms had a remarkable decrease in bone mineral content. 3) After PTX, none of patients had recurrent urolithiasis and bone mineral content of all patients was significantly increased in a short time. In addition, upper GI complaints were improved, or hypertension was partially normalized. However, renal insufficiency remained unchanged. 4) In preoperative localization study, Ultrasound sonography (US) demonstrated the best accuracy rate of 88% when only one gland was involved. US was able to detect multiple gland involvement only in 20% of 5 cases. 5) Hypercalciuria was recognized as one of the risk factors of stone formation in patients with primary hyperparathyroidism. 相似文献
39.
To evaluate the number and function of suppressor T cells in children with minimal change nephrotic syndrome (MCNS), we performed an inhibition test of rosette formation and measured leukocyte procoagulant activity. The number of histamine H2 receptor-bearing T lymphocytes (histamine H2 R+ lymphocytes) was markedly decreased at the onset of MCNS but gradually increased and was normalized following steroid therapy. The production of leukocyte procoagulant activity by normal T lymphocytes was abolished by incubation with patient's lymphocytes. However, pretreatment of the normal T lymphocytes with cimetidine markedly decreased the suppression. The results suggest an abnormality in the histamine H2 receptors on the patient's suppressor T lymphocytes. 相似文献
40.
Yuichi Ando Kenji Kikuchi Naoya Ichikawa Kazuhiko Meigata Yuji Nomura Kenshi Watanabe Yoshifumi Beck Hisakazu Degawa Shinji Tomikawa Takeshi Nagao Hisanori Chida 《Surgery today》1997,27(4):353-356
We herein report the case of a 53-year-old man with a nonspecific acute colonic ulcer whose liver function deteriorated after he had undergone hepatectomy. He was referred to our hospital for a hepatoma caused by hepatitis B virus and a right hemihepatectomy was performed. His liver function was poor after the operation, and minor complications such as pleural effusion and biliary fistula developed. A large amount of melena was seen 29 days after the hepatectomy and he developed hemorrhagic shock. Superior mesenteric arteriography revealed pooling of blood in both the hepatic flexure of the ascending colon and the cecum. An emergency right hemicolectomy was performed. There was a 5 x 1-mm ulcer 18 cm distal to the ileocecal valve. Numerous erosions were observed to be scattered throughout the colonic mucosa. The patient recovered slowly and was discharged 6 months after the hepatectomy. This is the first report of an acute colonic ulcer that could have been caused by liver dysfunction. 相似文献