全文获取类型
收费全文 | 26312篇 |
免费 | 1326篇 |
国内免费 | 98篇 |
专业分类
耳鼻咽喉 | 421篇 |
儿科学 | 490篇 |
妇产科学 | 326篇 |
基础医学 | 3593篇 |
口腔科学 | 669篇 |
临床医学 | 1809篇 |
内科学 | 6508篇 |
皮肤病学 | 651篇 |
神经病学 | 1786篇 |
特种医学 | 1056篇 |
外国民族医学 | 1篇 |
外科学 | 4361篇 |
综合类 | 143篇 |
一般理论 | 2篇 |
预防医学 | 700篇 |
眼科学 | 323篇 |
药学 | 1979篇 |
中国医学 | 77篇 |
肿瘤学 | 2841篇 |
出版年
2022年 | 285篇 |
2021年 | 436篇 |
2020年 | 264篇 |
2019年 | 338篇 |
2018年 | 426篇 |
2017年 | 344篇 |
2016年 | 423篇 |
2015年 | 412篇 |
2014年 | 609篇 |
2013年 | 698篇 |
2012年 | 1136篇 |
2011年 | 1228篇 |
2010年 | 683篇 |
2009年 | 672篇 |
2008年 | 1086篇 |
2007年 | 1257篇 |
2006年 | 1161篇 |
2005年 | 1240篇 |
2004年 | 1174篇 |
2003年 | 1039篇 |
2002年 | 1009篇 |
2001年 | 1021篇 |
2000年 | 961篇 |
1999年 | 897篇 |
1998年 | 309篇 |
1997年 | 212篇 |
1996年 | 236篇 |
1995年 | 190篇 |
1994年 | 160篇 |
1993年 | 187篇 |
1992年 | 628篇 |
1991年 | 546篇 |
1990年 | 533篇 |
1989年 | 528篇 |
1988年 | 512篇 |
1987年 | 483篇 |
1986年 | 459篇 |
1985年 | 426篇 |
1984年 | 311篇 |
1983年 | 256篇 |
1982年 | 158篇 |
1979年 | 245篇 |
1978年 | 157篇 |
1977年 | 184篇 |
1973年 | 177篇 |
1972年 | 186篇 |
1971年 | 190篇 |
1970年 | 172篇 |
1969年 | 186篇 |
1968年 | 170篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Takashi Ito Kazuo Shimamura Kiyoshi Shoji Akira Akatsuka Yasuyoshi Kiryu Norikazu Tamaoki Yoshiyuki Osamura 《Virchows Archiv : an international journal of pathology》1993,422(6):487-490
A rare case of urinary bladder carcinoma with granulocyte colony stimulating factor (G-CSF) production was reported. In an 83-year-old female, marked neutrophilia in the peripheral blood decreased from 132,500/mm3 to 3,300/mm3 after tumour resection. The tumour was a transitional cell carcinoma. The serum G-CSF level reduced from 238 pg/ml pre-operatively to normal (60 pg/ml) after the operation. Immunohistochemical investigation of the resected tumour with monoclonal antibody specific for G-CSF revealed positive staining in the carcinoma cells, confirming G-CSF secretion. 相似文献
992.
Yamakami S Toyama J Okamoto M Matsushita T Murakami Y Ogata M Ito S Fukutomi T Okayama N Itoh M 《Japanese heart journal》2003,44(6):811-822
This study evaluates the usefullness of intravenous electron beam computed tomographic angiography (EBA) for the detection of coronary artery bypass graft patency in 43 patients (33 men and 10 women, mean age, 65 years) who had coronary artery bypass graft surgery. EBA was performed a few days before selective bypass graft angiography (SGA). Forty axial cross-sections of angiographic images of the heart were acquired consecutively by an electrocardiographic trigger signal at 40% of the RR interval, which corresponds to the end-systolic phase. EBA data were reconstructed as a three-dimensional shaded surface display of the heart and bypass grafts. Detectability of the patency of bypass gratis was evaluated, taking selective angiographic images of the bypass grafts as a gold standard. One hundred and nine grafts (96%) out of 114 grafts were subjected to evaluation: 37 grafts were left internal mammary artery grafts (LIMA), 7 were right internal mammary artery grafts (RIMA), 6 were gastroepiploic artery grafts (GEA), 7 were free gastroepiploic artery grafts with venous drainage (free-GEA), 7 were radial artery grafts (RAG), and 45 were saphenous vein gratis (SVG). The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of EBA were 98%, 100%, 100%, 91%, and 98%, respectively. EBA sampled at the end-systolic period was determined to be useful for the detection of coronary artery bypass graft patency and occlusion. 相似文献
993.
Angiotensin within the central nervous system appears to be important for the maintenance of hypertension in spontaneously hypertensive rats. This study addresses the hypothesis that blockade of AT1 receptors in the rostral ventrolateral medulla would decrease blood pressure in spontaneously hypertensive rats and that this tonically active AT1-mediated input to the rostral ventrolateral medulla arises from the hypothalamic paraventricular nucleus. Injection of the nonpeptide AT1 receptor antagonist valsartan bilaterally into the rostral ventrolateral medulla of choralose-anesthetized adult spontaneously hypertensive rats produced a dose-related decrease in mean arterial pressure, with a maximal effect of approximately 30 mm Hg. Inhibition of the paraventricular nucleus by local injection of muscimol elicited a similar response, which was inhibited by prior injection of valsartan into the rostral ventrolateral medulla. In contrast, in control Wistar-Kyoto rats, neither valsartan injected into the rostral ventrolateral medulla nor muscimol injected into the paraventricular nucleus had a substantial effect on arterial pressure. These data indicate that in spontaneously hypertensive rats but not in Wistar-Kyoto rats, rostral ventrolateral medulla vasomotor neurons are tonically excited by endogenous stimulation of AT1 receptors, and this input is apparently driven from the hypothalamus. These results suggest that the rostral ventrolateral medulla is one site that the brain renin-angiotensin system acts to maintain elevated blood pressure in spontaneously hypertensive rats. 相似文献
994.
Hiroyuki Isayama Yousuke Nakai MD PhD Yoshihide Toyokawa MT Osamu Togawa MD Chimyon Gon MT Yukiko Ito MD Yoko Yashima MD Hiroshi Yagioka MD Hirofumi Kogure MD Takashi Sasaki MD Toshihiko Arizumi MD Saburo Matsubara MD Natsuyo Yamamoto MD PhD Naoki Sasahira MD PhD Kenji Hirano MD PhD Takeshi Tsujino MD PhD Nobuo Toda MD PhD Minoru Tada MD PhD Takao Kawabe MD PhD Masao Omata MD PhD 《Gastrointestinal endoscopy》2009,70(1):37-44
995.
Vascular endothelial growth factor (VEGF) is a survival factor in endothelial cells and a promoter of angiogenesis that reportedly plays a pivotal role protecting against injury. In aged humans and animals, lung injuries are generally more serious and cause higher mortality. We thus hypothesized that the expression of VEGF and its related molecules in the lung declines with age. In this study, we first examined the expression of VEGF family (VEGF-A, -B, -C and -D), VEGF-A isoforms (VEGF120, 164, 188), and VEGF-specific receptors (VEGFR-1: Flt-1; VEGFR-2: Flk-1 and VEGFR-3: Flt-4) by quantitative RT-PCR in lungs from young and old mice. Expression of all these except for VEGF-D was significantly lower in old mice than in young mice. We then subjected young and old mice to lipopolysaccaride (LPS)-induced lung injury. Old animals demonstrated poor survival and prolonged lung inflammation when compared with young counterparts. At 24 and 72 h after intratracheal LPS administration, expression of the examined factors was down-regulated in the lungs irrespective of age. In conclusion, pulmonary expression of the VEGF family and their receptors declines with age, and is further down-regulated in LPS-induced lung injury, although the mechanism of age- and/or injury-related down-regulation of VEGF remains unknown. 相似文献
996.
Ito K Hirooka Y Kimura Y Shimokawa H Takeshita A 《Clinical and experimental hypertension (New York, N.Y. : 1993)》2005,27(2-3):269-277
Previously, we reported that the inhibition of Rho-kinase by a microinjection of Y-27632 or the transfection of dominant-negative Rho-kinase into cells of the nucleus tractus solitarii (NTS) reduces blood pressure, heart rate, and sympathetic nerve activity. In the present study, we examined the effects of another Rho-kinase inhibitor, hydroxyfasudil, on blood pressure and heart rate in anesthetized rats. The results were compared between normotensive Wistar-Kyoto (WKY) rats and spontaneously hypertensive rats (SHR). The microinjection of hydroxyfasudil was performed unilaterally or bilaterally into the NTS of WKY rats and SHR. A unilateral microinjection of hydroxyfasudil elicited depressor and bradycardic responses in SHR but not in WKY rats. A bilateral microinjection of hydroxyfasudil elicited depressor and bradycardic responses in both SHR and WKY rats. However, the magnitude of the decrease in these variables was greater in SHR than in WKY rats. The expression levels of RhoA in the membrane fraction and phosphorylated ERM family (ezrin, radixin, and moesin) in the NTS were greater in SHR than in WKY rats. These results suggest that the microinjection of hydroxyfasudil into the NTS causes cardiovascular responses similar to those caused by Y-27632 and that these responses are probably mediated by the inhibition of Rho-kinase. 相似文献
997.
Tomoda C Uruno T Takamura Y Ito Y Miya A Kobayashi K Matsuzuka F Amino N Kuma K Miyauchi A 《Endocrine journal》2005,52(2):237-240
To decrease total body iodine is a key point in preparation for radioiodine study and therapy. We introduced a stringent self-managed low iodine diet (LID) and compared the outcome to that of the conventional restricted iodine diet (RID) for outpatients. We measured urine iodine to creatinine ratios (I/Cr) in patients prepared with RID for one week, LID for one week, or LID for two weeks. Mean urinary iodine excretion after RID for one week (n = 210) was 182.2 microg/gCr (range, 13-986 microg/gCr; standard deviation (SD) = 158.5) not reaching below the recommended level (I/Cr<100 microg/gCr). Urinary iodine excretion after LID for one week (n = 15) showed a lower mean urinary iodine level (I/Cr 119.4 microg/gCr; range, 23-218 microg/gCr; SD = 55.9) than RID for one-week, and two-week LID (n = 17) showed an even lower mean level (I/Cr 63.1 microg/gCr; range, 7-134 microg/gCr; SD = 38.7). The one-week LID period adequately (recommended level of I/Cr being less than 100 microg/gCr) prepared 26% of the patients, while two-weeks on the diet adequately prepared 70% of the patients. Furthermore, none of the two-week LID patients had I/Cr>150 microg/gCr, although a significantly greater number of one-week LID patients (19%) did. Our self-managed, outpatient LID successfully induced iodine deficiency, and two-week LID may be recommended for preparation in radioiodine study and therapy for thyroid cancer. 相似文献
998.
Multiple bone fractures found in a young sarcoidosis patient with long stable disease 总被引:1,自引:0,他引:1
Handa T Nagai S Ito I Shigematsu M Hamada K Kitaichi M Ohta K Izumi T Mishima M 《Internal medicine (Tokyo, Japan)》2005,44(12):1269-1275
A 22-year-old Japanese man was found to have bilateral hilar lymphadenopathy (BHL), and was diagnosed with sarcoidosis in 1995. He was followed without treatment until 2002, when a bone fracture due to osseous sarcoidosis was found in his left thumb. Despite systemic treatment with corticosteroid and methotrexate, a new bone lesion developed in his right foot and his right middle finger was fractured. The patient also suffered multiple organ involvements including brain and muscle lesions. This is the first report of a sarcoidosis patient who presented with BHL, and developed bone fractures after a long stable period of more than 5 years. 相似文献
999.
Nagata S Tanaka S Ito M Yoshihara M Haruma K Chayama K 《Journal of gastroenterology and hepatology》2005,20(9):1461-1463
Reported herein is a very rare polyp in the gastric cardia of a 49-year-old man. He was referred because of a polyp detected by upper gastrointestinal examination in an affiliated hospital. Endoscopic examination revealed a polyp-like submucosal tumor. Endoscopic ultrasonography revealed minute cystic dilatations and thickening of the submucosal layer. Accordingly, a preliminary diagnosis of cardiac gland hyperplasia was made. The lesion was removed successfully by snare polypectomy. Observed macroscopically, the polyp was 30 mm in diameter and covered with normal gastric mucosa. Examined histologically, the polyp comprised a hyperplastic submucosal cardiac gland. 相似文献
1000.
Chihiro Nishio Takashi Hajiro Taishi Nagao Masami Ito Chikara Sakaguchi Yasutaka Nakano 《The Journal of asthma》2013,50(4):339-342
Background. The prevalence of obesity and asthma has been increasing during the last several decades. Obesity has been reported to be associated with asthma. Obesity, especially abdominal obesity, is the main component of the metabolic syndrome. Objectives. We thus hypothesized that metabolic syndrome is an important contributing factor for the development of asthma-like symptoms. Methods. The Korean Health and Genome Study started in 2001 as an ongoing population-based study of Korean adults 40 to 69 years of age. The prevalence of asthma-like symptoms in the previous 12 months was obtained by a questionnaire, and spirometric testing was conducted. Results. Among the 10,038 participants, the data from 9,942 individuals (4,716 men and 5,226 women) was available. Asthma-like symptoms (wheeze [p = 0.0006], resting dyspnea [p = 0.0062], and post-exercise dyspnea [p < 0.0001]) were increased in the subjects of the metabolic syndrome group. Subjects with asthma-like symptoms had a decreased lung function compared to subjects without asthma-like symptoms. Among the components of the metabolic syndrome, abdominal obesity and hypertension were the risk factors for asthma-like symptoms. Conclusions. Metabolic syndrome is associated with asthma-like symptoms. Among the components of metabolic syndrome, abdominal obesity and hypertension are the risk factors for asthma-like symptoms. 相似文献