全文获取类型
收费全文 | 10432篇 |
免费 | 509篇 |
国内免费 | 67篇 |
专业分类
耳鼻咽喉 | 152篇 |
儿科学 | 152篇 |
妇产科学 | 109篇 |
基础医学 | 1455篇 |
口腔科学 | 293篇 |
临床医学 | 647篇 |
内科学 | 2925篇 |
皮肤病学 | 93篇 |
神经病学 | 739篇 |
特种医学 | 364篇 |
外科学 | 1466篇 |
综合类 | 41篇 |
预防医学 | 312篇 |
眼科学 | 361篇 |
药学 | 859篇 |
中国医学 | 12篇 |
肿瘤学 | 1028篇 |
出版年
2023年 | 64篇 |
2022年 | 118篇 |
2021年 | 168篇 |
2020年 | 103篇 |
2019年 | 132篇 |
2018年 | 172篇 |
2017年 | 121篇 |
2016年 | 204篇 |
2015年 | 196篇 |
2014年 | 226篇 |
2013年 | 295篇 |
2012年 | 475篇 |
2011年 | 534篇 |
2010年 | 324篇 |
2009年 | 255篇 |
2008年 | 505篇 |
2007年 | 539篇 |
2006年 | 517篇 |
2005年 | 545篇 |
2004年 | 558篇 |
2003年 | 562篇 |
2002年 | 548篇 |
2001年 | 337篇 |
2000年 | 326篇 |
1999年 | 285篇 |
1998年 | 166篇 |
1997年 | 113篇 |
1996年 | 103篇 |
1995年 | 77篇 |
1994年 | 86篇 |
1993年 | 73篇 |
1992年 | 226篇 |
1991年 | 180篇 |
1990年 | 178篇 |
1989年 | 177篇 |
1988年 | 174篇 |
1987年 | 161篇 |
1986年 | 138篇 |
1985年 | 116篇 |
1984年 | 101篇 |
1983年 | 72篇 |
1982年 | 50篇 |
1981年 | 42篇 |
1979年 | 76篇 |
1978年 | 57篇 |
1976年 | 46篇 |
1972年 | 45篇 |
1971年 | 42篇 |
1970年 | 42篇 |
1968年 | 45篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
Chinori Kurata MD PhD Sakae Shouda MD Tadashi Mikami MD Yasushi Wakabayashi MD Tomoyasu Nakano MD Tsuyoshi Sugiyama MD Kei Tawarahara MD PhD Kazuyuki Sakata MD PhD 《Journal of nuclear cardiology》1997,4(6):515
Background. [123I]Metaiodobenzylguanidine (MIBG) imaging has been used to assess cardiac sympathetic nerve abnormalities. We evaluated the clinical significance of myocardial MIBG imaging as a measure of cardiac sympathetic nervous system function by comparing it to heart rate variability and plasma norepinephrine level.Methods and Results. In 211 subjects, we analyzed heart rate variability with 24-hour electrocardiography, performed scintigraphy with MIBG, and measured plasma norepinephrine levels. Time and frequency domain measures of heart rate variability were calculated with the Marquette heart rate variability program (Marquette Electronics, Milwaukee, Wis.). Early and late myocardial MIBG uptakes were measured at 15 and 150 minutes after injection, respectively. MIBG clearance rate from the heart and heart-to-lung and heart-to-mediastinum ratios of MIBG activities were calculated. On the whole, heart rate variability, including low-frequency power, correlated positively, but modestly so, with late MIBG uptake and negatively with MIBG clearance rate. The plasma norepinephrine level correlated negatively with late MIBG uptake and with heart rate variability, including low-frequency power, and positively with MIBG clearance rate. Similar correlations were also observed in patient subgroups with coronary artery disease, diabetes mellitus, and renal failure, but these correlations were weak (R2 < 0.5).Conclusions. Increased cardiac sympathetic nervous system activity may be associated with increased myocardial MIBG clearance and decreased heart rate variability, including low-frequency power. Because these associations were not strong, however, the combination of heart rate variability with MIBG may allow an interactive assessment of the cardiac autonomic nervous system. 相似文献
62.
Tatsuo Uchida Takahiko Tokumaru Hiroshi Kojima Katsura Nakagawaji Munehisa Imaizumi Toshio Abe 《Surgery today》1992,22(3):265-268
A 36 year old woman was admitted to our department because of a chest X-ray which showed multiple developing shadows. She underwent bilateral exploratory thoracotomies and a total 5 tumors were resected and pathologically diagnosed as benign metastasizing leiomyoma, the largest of which was positive for the progesterone receptor and negative for the estrogen receptor. A histogram of this tumor using a flow cytometer showed a diploid pattern and 4.6 percent of the S phase which was not more than that of a leiomyoma of the uterus from another patient. Two months later, she underwent a hysterectomy and bilateral salpingo-oophorectomy for treatment of the positive progesterone receptor in the pulmonary lesions. The resected uterine myoma and normal myometrium showed positive estrogen and progesterone receptors. For the subsequent 28 months she has been free of any further symptoms. Benign metastasizing leiomyoma of the uterus is a rare disease and very interesting because of its histological benignity and hormonal dependency. However, according to the literature, it is often confused in entity due to the fact that normal lung tissue also possesses hormone receptors. Considering our data on hormone receptors, it is rational to think that multiple leiomyomatous lesions in the lung should only be diagnosed as benign metastasizing leiomyomas when they possess positive estrogen and progesterone receptors. 相似文献
63.
64.
Ouabain has recently been reported to be an endogenous Na, K-ATPase inhibitor. To evaluate whether it exerts hypertensive action itself or amplifies the hypertensive action of small doses of mineralocorticoids, 5 mg deoxycorticosterone acetate (DOCA), 1 mg ouabain, or a combination of both were injected into mononephrectomized rats weekly for 6 weeks, and changes in blood pressure were evaluated. The blood pressures of control, DOCA-treated, ouabain-treated, and the combination treatment group at the sixth week were 138 +/- 3 (SE), 160 +/- 6, 144 +/- 6, and 201 +/- 14 mmHg, respectively. The blood pressure of rats given DOCA or ouabain alone was not significantly different from that of controls. In contrast, the blood pressure of rats given the combination of DOCA and ouabain was significantly higher than that of control rats and those given DOCA or ouabain separately. Cardionephromegaly and histopathological changes found in rats given the combination of DOCA and ouabain were consistent with the effects of an elevation of blood pressure. Further evaluation revealed that the amplification effect of ouabain on the hypertensive action of DOCA was dose dependent, with the minimum dose that caused the amplification effect being 0.25 mg/week. These results indicate that ouabain, although devoid of hypertensive action itself, amplifies the hypertensive action of small doses of DOCA and can cause a hypertensive state similar to that induced by larger doses of DOCA. It is inferred that the amplification effect of ouabain on mineralocorticoids is important in the genesis of hypertension. 相似文献
65.
Synchronous pulmonary atypical adenomatous hyperplasia and metastatic osteosarcoma in a young female
Ken Kodama Masahiko Higashiyama Koji Takami Naozumi Higaki Kazuyuki Oda Nobuhito Araki 《The Japanese Journal of Thoracic and Cardiovascular Surgery》2004,52(7):357-359
A 17-year-old female underwent metastasectomy of three synchronous lesions in the bilateral lungs under the diagnosis of metastatic
osteosarcoma, however, one of them was found to be atypical adenomatous hyperplasia (AAH). Since AAH is very rare among young
people, a careful evaluation of high-resolution computed tomographic image is important in determining the operative indications
and procedures in patients with multiple metastatic tumors. 相似文献
66.
67.
68.
69.
Eight adult cats of either sex were studied. The minimal alveolar concentration (MAC) for sevoflurane in the cats was found to be 2.58 ± 0.30% (mean ± SD). The ratios of MAC values between sevoflurane and halothane, enflurane and isoflurane in cats were very similar to those ratios found in humans and dogs. This observation suggests that the results of this study are correct and allows us to estimate unknown MAC values for sevoflurane in other species using known MAC values for other anesthetic agents.(Doi M, Yunoki H, Ikeda K: The minimum alveolar concentration of sevoflurane in cats. J Anesth 2: 113–114, 1988) 相似文献
70.
A 72-year-old male was admitted because of right lower quadrant pain, Barium enema and total colonoscopy disclosed multiple colon cancers and sequentially, a subtotal colectomy was performed. The resected specimen demonstrated 3 advanced carcinomas and an adenomatous cancer with additional multiple polyps. Investigation of his family history revealed that his mother and his elder sister had died of uterine cancer, and that his elder brother, his nephew, and his niece had been operated on for colorectal cancer. We thus supposed a case of "Cancer Family Syndrome" presenting multiple neoplasms of the colon. 相似文献