全文获取类型
收费全文 | 18876篇 |
免费 | 888篇 |
国内免费 | 130篇 |
专业分类
耳鼻咽喉 | 97篇 |
儿科学 | 390篇 |
妇产科学 | 289篇 |
基础医学 | 2096篇 |
口腔科学 | 324篇 |
临床医学 | 1223篇 |
内科学 | 5239篇 |
皮肤病学 | 272篇 |
神经病学 | 1360篇 |
特种医学 | 665篇 |
外科学 | 3375篇 |
综合类 | 80篇 |
预防医学 | 375篇 |
眼科学 | 514篇 |
药学 | 1153篇 |
中国医学 | 40篇 |
肿瘤学 | 2402篇 |
出版年
2023年 | 124篇 |
2022年 | 241篇 |
2021年 | 464篇 |
2020年 | 262篇 |
2019年 | 367篇 |
2018年 | 419篇 |
2017年 | 339篇 |
2016年 | 426篇 |
2015年 | 447篇 |
2014年 | 563篇 |
2013年 | 620篇 |
2012年 | 1159篇 |
2011年 | 1162篇 |
2010年 | 700篇 |
2009年 | 582篇 |
2008年 | 1017篇 |
2007年 | 1065篇 |
2006年 | 1109篇 |
2005年 | 1039篇 |
2004年 | 1076篇 |
2003年 | 1013篇 |
2002年 | 1057篇 |
2001年 | 412篇 |
2000年 | 378篇 |
1999年 | 390篇 |
1998年 | 254篇 |
1997年 | 212篇 |
1996年 | 181篇 |
1995年 | 138篇 |
1994年 | 145篇 |
1993年 | 117篇 |
1992年 | 239篇 |
1991年 | 209篇 |
1990年 | 189篇 |
1989年 | 190篇 |
1988年 | 172篇 |
1987年 | 120篇 |
1986年 | 148篇 |
1985年 | 139篇 |
1984年 | 102篇 |
1983年 | 87篇 |
1982年 | 45篇 |
1979年 | 89篇 |
1978年 | 50篇 |
1977年 | 58篇 |
1974年 | 51篇 |
1973年 | 51篇 |
1972年 | 47篇 |
1971年 | 59篇 |
1968年 | 46篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
Naoaki Takemoto Hiroaki Kuroda Yoshinobu Nakamura Takashi Ichiba Naruto Matsuda Yasushi Ashida Takafumi Hamasaki Yohichi Hara Shingo Ishiguro Tohru Mori 《Surgery today》1996,26(3):179-183
The effects of calcium (Ca) on a hyperkalemic cardioplegic solution for continuous cardioplegia were examined in an isolated perfused working rat heart model. The coronary arteries were perfused with a modified Krebs-Henseleit bicarbonate buffer (K-H) solution, containing various concentrations of Ca(0.1, 0.6, 1.2, and 2.5 mmol/l) and a high concentration of potassium (20 mmol/l), for 180 min, after which cardiac arrest was induced at 37°C for 180 min. Cardiac function and creatine kinase (CK) were measured. In the control group, K-H solution was infused in place of the cardioplegic solution, and cardiac arrest was not induced. No significant differences were observed between the groups infused with the K-H solution containing Ca concentrations of 0.6, 1.2, and 2.5 mmol/l in the percent recovery of aortic flow (82.1±2.9%, 80.6±2.0%, and 71.5±3.7% (mean±SEM) respectively) or in the recovery of other indices of cardiac function, or in CK leakage. There were also no significant differences in the recovery of cardiac function and CK leakage between these groups and the control group. In the Ca 0.1 mmol/l group, however, the characteristic Ca paradox was observed. These findings suggest that if the Ca concentration in a cardioplegic solution is higher than 0.6 mmol/l during continuous cardioplegia, excellent cardioprotective effects will be achieved. 相似文献
52.
Hiroshi Okimura Masahiko Muto Makoto Ichimiya Satoshi Mogami Hiroaki Takahata Chidori Asagami 《The Journal of dermatology》1996,23(9):631-634
A 58-year-old Japanese woman who had herpes zoster in association with colitis was successfully treated with intravenously administrated acyclovir. Vesicular lesions with red haloes ranged from the left side of her buttock to the left extremity, corresponding to the L4 to S2 dermatomes. Her colitis was considered to have been induced by varicella-zoster virus, based on the facts that the clinical courses were correlated and that the innervation of the affected site of the colon corresponded to an infected dermatome (S2). 相似文献
53.
A 47-year-old woman visited a clinic with dyspnea which had continued for two months and was followed by general fatigue and fever. Antibiotics were not effective. Edematous erythema occurred on her face, elbows, knees and feet, and she entered our hospital. A skin biopsy revealed interface dermatitis with severe edema and mucinosis in dermis. Diffuse bilateral infiltration was observed in the chest X-ray, and laboratory findings showed increased LDH, GPT, GOT and CPK. No antinuclear factor was detected. Her respiratory condition rapidly worsened, and she died eight days after hospitalization in spite of corticosteroid pulse therapy. The autopsy revealed that the main cause of death was diffuse alveolar damage (DAD). Interstitial pneumonia related to dermatomyositis is not histologically uniform; the response to the therapy depends on its histological type. The patients with dermatomyositis who have poor prognosis are clinically characterized by acute onset with general symptoms and less pronounced muscle weakness; they generally show DAD in their lungs. We need to establish a simple method for distinguishing histological types of interstitial pneumonia and adequate therapy for each one. 相似文献
54.
Two patients with "my hand" sign in association with tactile extinction from callosal lesion, one due to left anterior cerebral artery occlusion, the other due to right anterior cerebral artery aneurysm rupture, were reported. The examination of "my hand" sign was performed with the methods proposed by Brion et al. Our patients correctly responded when they grasped their own or the examiner's thumb with their left hand. But they replied "my finger"when they grasped not only their own but also the examiner's thumb with their right hand. Left tactile extinction was observed after a routine extinction test in one patient, and it was observed in the other after the following method: both patient's index fingers were disposed in his midline position. In these methods of extinction test, they made errors in saying "right" when both fingers were touched simultaneously. However, they said "both" when their right index finger alone was touched (synchiria) during an extinction test using the following method: both index fingers of patients were approached by examiner to touch each other or for one of them to touch the examiner's finger. When they were asked whose finger they touched in this method (whose finger test), they made the same errors as seen in "my hand" sign test. These test results suggest that there is a common underlying mechanism in the "my hand" sign and extinction, because the sense of double stimulations felt when only one stimulation is given (synchiria), is a possible explanation for the "my hand" sign and the pathogenesis of synchiria appears to be related to extinction.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
55.
Shunsuke Imai Susumu Sekigawa Yoshitaka Ohno Hiroaki Yamamoto Yoshihiko Tsubura 《Pathology international》1981,31(1):129-133
A case of giant cell carcinom of the pancreas is reported herein. The patient is a 67-year-old Japanese woman complaining of ascites, general fatigue, loss of weight, abdominal distention, nausea, and vomiting. Cytological diagnosis of ascites revealed adenocarcinoma. At autopsy, a whitish tumor measuring around 5 cm in diameter was found at the head of the pancreas. Metastasis was seen only in the liver. Histological examination displayed bizarre multinucleated giant cells occasionally phagocytosing the tumor cells and neutrophils. 相似文献
56.
Norio Kunieda Akira Suzuki Masayoshi Kinoshita Minoru Imoto 《Macromolecular chemistry and physics.》1972,152(1):27-33
The acid-catalyzed condensation of formaldehyde and diphenyl sulfide was carried out in benzene in the presence of p-toluene sulfonic acid. From the products, four poly(methylene diphenyl sulfides) of the following structures were isolated. 相似文献
57.
Yozo Miura Yuzo Morimoto Masayoshi Kinoshita 《Macromolecular chemistry and physics.》1974,175(12):3487-3493
2,4,6-Triphenyl-3,4-dihydro-s-tetrazin-1(2H)-yl ( 1 ) (1,3,5-triphenylverdazyl) was allowed to react with ethyl- and butyllithium, ethyl-, isopropyl-, and butylmagnesium bromide, as well as benzylmagnesium chloride to give the coupling products 2a–d . These results indicate that structures corresponding to 2 are present in the polymers resulting from vinyl monomers containing the verdazyl structure, if they are initiated with alkyllithium or a Grignard reagent. A reaction mechanism is discussed. 相似文献
58.
Antithrombin 3 (AT 3) activity was examined in pregnant women, women using oral contraceptives (mestranol .1 mg plus norethisterone 2 mg daily or mestranol .05 mg plus norethisterone 1 mg daily), and women on the gestagens alone. AT 3 activity in serum was found to decrease significantly in the third trimester of pregnancy and postpartum period (2 or 3 days); it returned to the level of nonpregnant females 6 or 7 days postpartum. AT 3 in plasma as well as serum was found to decrease significantly after the first month administration of the oral contraceptives. It returned to normal level after the cessation of administration. The successive course of administration again caused the decrease of AT 3 activity. The degree of the decrease became less and less. Finally the decrease was not in effect after 3-5 courses of administration. Norethisterone alone did not cause any change of AT 3 level. (Author's Modified) 相似文献
59.
Systematic changes in gene expression in postmortem human brains associated with tissue pH and terminal medical conditions 总被引:8,自引:0,他引:8
60.
A Masunaga T Oka H Nakamura K Kinoshita T Yamashita I Sugawara S Itoyama 《Acta pathologica japonica》1992,42(12):916-922
A case of intrauterine tumor in a 62-year-old Japanese woman is presented. It was thought initially that this was a case of uterine tumor resembling an ovarian sex cord tumor. To examine the cytological features of the tumor cells, electron microscopical and immunohistochemical studies were done, and a hormone assay of the tumor tissue was performed. The tumor cells were rich in rough endoplasmic reticulum (rER), mitochondria and microfilaments. Some tumor cells tended to form glandular patterns, but these epithelial elements were frequently scattered among fibrous stromal elements. Though many tumor cells with an epithelial appearance possessed a large quantity of cytokeratin and vimentin, they did not secrete estradiol, progesterone, testosterone or human chorionic gonadotropin. This case was finally diagnosed as an intramural uterine stromal tumor with epithelial differentiation after taking all the available data into consideration. This would be classified as an endometrial stromal tumor with epithelial elements, recently proposed and named by Clement and Scully. 相似文献