全文获取类型
收费全文 | 3264篇 |
免费 | 152篇 |
国内免费 | 25篇 |
专业分类
耳鼻咽喉 | 113篇 |
儿科学 | 43篇 |
妇产科学 | 65篇 |
基础医学 | 374篇 |
口腔科学 | 85篇 |
临床医学 | 219篇 |
内科学 | 896篇 |
皮肤病学 | 76篇 |
神经病学 | 208篇 |
特种医学 | 175篇 |
外科学 | 573篇 |
综合类 | 6篇 |
预防医学 | 103篇 |
眼科学 | 35篇 |
药学 | 230篇 |
中国医学 | 5篇 |
肿瘤学 | 235篇 |
出版年
2023年 | 28篇 |
2022年 | 44篇 |
2021年 | 61篇 |
2020年 | 39篇 |
2019年 | 52篇 |
2018年 | 49篇 |
2017年 | 35篇 |
2016年 | 58篇 |
2015年 | 56篇 |
2014年 | 80篇 |
2013年 | 122篇 |
2012年 | 141篇 |
2011年 | 133篇 |
2010年 | 79篇 |
2009年 | 62篇 |
2008年 | 101篇 |
2007年 | 119篇 |
2006年 | 115篇 |
2005年 | 124篇 |
2004年 | 102篇 |
2003年 | 116篇 |
2002年 | 146篇 |
2001年 | 122篇 |
2000年 | 118篇 |
1999年 | 115篇 |
1998年 | 45篇 |
1997年 | 36篇 |
1996年 | 21篇 |
1995年 | 36篇 |
1994年 | 28篇 |
1993年 | 26篇 |
1992年 | 104篇 |
1991年 | 76篇 |
1990年 | 84篇 |
1989年 | 65篇 |
1988年 | 86篇 |
1987年 | 62篇 |
1986年 | 68篇 |
1985年 | 59篇 |
1984年 | 50篇 |
1983年 | 48篇 |
1981年 | 19篇 |
1979年 | 37篇 |
1978年 | 23篇 |
1977年 | 23篇 |
1974年 | 21篇 |
1972年 | 20篇 |
1971年 | 23篇 |
1968年 | 21篇 |
1966年 | 21篇 |
排序方式: 共有3441条查询结果,搜索用时 15 毫秒
101.
Responses of plasma adrenocorticotropic hormone, cortisol, and cytokines during and after upper abdominal surgery. 总被引:31,自引:0,他引:31
Y Naito S Tamai K Shingu K Shindo T Matsui H Segawa Y Nakai K Mori 《Anesthesiology》1992,77(3):426-431
There is currently accumulating evidence for bidirectional communication between the neuroendocrine and immune systems. Various cytokines have been suggested to be involved in the stimulation of stress hormone secretion during the times of infection and inflammation. To assess the possible involvement and pathophysiologic significance of cytokines in the mechanisms responsible for the perioperative stress response of the hypothalamo-pituitary-adrenal axis, we observed the changes of plasma adrenocorticotropic hormone and cortisol levels together with those of plasma endotoxin and cytokine levels. In patients undergoing pancreatoduodenectomy, perioperative stimulation of adrenocorticotropic hormone and cortisol secretion was accompanied by a significant elevation of plasma cytokine levels. Application of epidural block up to the upper thoracic levels failed to suppress this stress response effectively. In patients undergoing unilateral total hip replacement, the response of plasma hormone levels was smaller and briefer with no significant increase of plasma cytokine levels. Application of epidural block up to the lower thoracic levels suppressed this hormonal response almost completely. In patients undergoing pancreatoduodenectomy, a significant elevation of plasma endotoxin level was followed by a gradual but significant elevation of plasma tumor necrosis factor alpha and interleukin-6 levels. It seems likely that the stimulatory effects of these cytokines on the secretion of adrenocorticotropic hormone and cortisol might be involved in the development of the greater and more prolonged stress response of hypothalamo-pituitary-adrenal axis. Our present study suggests that not only neural input from the surgical wound but also stimulation of cytokine production were responsible for the development of the stress response of the hypothalamo-pituitary-adrenal axis during and after upper abdominal surgery.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
102.
Purposes
Single-incision laparoscopic surgery improves the cosmetic outcome after surgery. We herein report six cases of successful single-incision laparoscopic (SILS) herniorrhaphy.Methods
Six patients, five with unilateral inguinal hernias and one with bilateral inguinal hernias, underwent SILS herniorrhaphy. A Covidien SILS port was inserted via an umbilical incision, through which three trocars of 5, 5 and 12 mm (or 5 mm) were inserted. The peritoneum was then opened with flexible scissors and electrocoagulation, after which, the preperitoneal space was dissected. A mesh was then fixed, and the peritoneum was finally closed using Covidien SILS Stitch or AbsorbaTack.Results
The mean length of the operation for the unilateral cases was 136 min. The increased time was due to difficulties unrelated to this methodology. However, the length of the operation in the bilateral case was 94 min. All patients were discharged without complications.Conclusions
SILS herniorrhaphy requires experience and more time than conventional three-port herniorrhaphy. However, if the length of the operation can be shortened, then this novel surgical technique is considered to be feasible and it is expected to improve the cosmetic outcome without any additional risk. 相似文献103.
104.
Masunaga R Nagasaka A Sawai Y Hayakawa N Nakai A Hotta K Kato Y Hishida H Takahashi H Naka M Shimada Y Tanaka T Hidaka H Itoh M 《Journal of molecular and cellular cardiology》2004,37(3):767-774
Cyclic nucleotides (cAMP and cGMP) phosphodiesterase (PDE) activities and expression are altered in the cardiac muscle of cardiomyopathic heart failure, and PDE inhibitors improve the abnormal muscle condition through changing the cyclic nucleotide concentration. These observations prompted us to investigate the role of calmodulin (CaM) in the regulation of cyclic nucleotide PDE activities, and moreover to study the modulation of the PDE isozymes in heart failure, using cardiac muscles of cardiomyopathic hamster. The CaM concentrations in the heart muscle of the normal control and cardiomyopathic hamsters (each of three to four hamsters) varied with cell fraction and with the age of the animal. The CaM concentrations in the soluble fraction obtained from cardiomyopathic hamster tissue were significantly increased at 25 and 32 weeks of age (2.02 +/- 0.62 microg/mg protein (mean +/- S.E.), and 3.21 +/- 0.95) compared with that obtained from the control (0.60 +/- 0.04) or cardiomyopathic (0.95 +/- 0.12) hamsters at 8 weeks of age. The solubilized PDE isolated from the hamster heart muscle (three or four hamsters in each age) by column chromatography on diethylaminoethyl (DEAE)-cellulose revealed three peaks of activity, which may correspond to the isozymes of PDE classified recently, namely PDE I, II, and III. These three peaks of activity, particularly peak III, seen in the soluble fraction of cardiomyopathic hamster heart declined in proportion to the age of the animal compared with that of the control hamster heart. In the cGMP-PDE assay system, the concentration of CaM inhibitor W-7 required for 50% inhibition (IC(50)) of PDE I, II, and III peak activities was 140, 29, and 46 microM, respectively, suggesting that PDE II is more sensitive to W-7. These results suggest that alteration in these isozyme activities accompanied with changes of CaM concentration may influence the cardiac muscle contractility in cardiomyopathic hamster via changes of cyclic nucleotide concentration. 相似文献
105.
Takao Takeshima Masami Nakai Yoshiyuki Shibasaki Miki Ishida Byung-Kun Kim Xiaoping Ning Nobuyuki Koga 《The journal of headache and pain》2022,23(1)
BackgroundEarly onset of action has become recognized as an important efficacy feature of preventive migraine treatment, which can help overcome adherence issues commonly associated with older medications. Preventive treatments that target the calcitonin gene-related peptide (CGRP) or the CGRP receptor have been previously shown to provide early onset of action.MethodsThis subanalysis of primary endpoints of two separate phase 2b/3 studies sought to determine the onset of action of fremanezumab in Japanese and Korean patients with episodic migraine (EM) and chronic migraine (CM).ResultsIn EM patients (n = 357), both fremanezumab quarterly and fremanezumab monthly led to greater reductions in weekly migraine days (days/week) than placebo from the first week after the initial injection and thereafter during the remainder of the study period. Similarly, CM patients (n = 571) had a greater reduction in headache days of at least moderate severity (days/week) with fremanezumab (total) than placebo. The percentage of patients with a migraine day (EM) or headache day at least moderate severity (CM) was lower in those treated with fremanezumab than placebo and this effect was apparent from as early as Day 2 (1 day after first injection).ConclusionsThese results suggest that fremanezumab has an early onset of action, as noted in previous post hoc analyses of anti-CGRP monoclonal antibodies.Trial registrationClinicalTrials.gov. , Registered 5 October 2017, NCT03303092, Registered 5 October 2017. NCT03303079相似文献
106.
Contrast‐enhanced harmonic endoscopic ultrasonography for differential diagnosis of localized gallbladder lesions 下载免费PDF全文
Ken Kamata Mamoru Takenaka Masayuki Kitano Shunsuke Omoto Takeshi Miyata Kosuke Minaga Kentaro Yamao Hajime Imai Tosiharu Sakurai Naoshi Nishida Hiroshi Kashida Takaaki Chikugo Yasutaka Chiba Takuya Nakai Yoshifumi Takeyama Andrea Lisotti Pietro Fusaroli Masatoshi Kudo 《Digestive endoscopy》2018,30(1):98-106
Background and Aim
Differential diagnosis of localized gallbladder lesions is challenging. The aim of the present study was to evaluate the utility of contrast‐enhanced harmonic endoscopic ultrasonography (CH‐EUS) for diagnosis of localized gallbladder lesions.Methods
One hundred and twenty‐five patients with localized gallbladder lesions were evaluated by CH‐EUS between March 2007 and February 2014. This was a single‐center retrospective study. Utilities of fundamental B‐mode EUS (FB‐EUS) and CH‐EUS in the differentiation of gallbladder lesions and sludge plug were initially compared. Thereafter, these two examinations were compared with respect to their accuracy in the diagnosis of malignant lesions. Five reviewers blinded to the clinicopathological results evaluated microcirculation patterns in the vascular and perfusion images.Results
In the differentiation between gallbladder lesions and sludge plug, FB‐EUS had a sensitivity, specificity, and accuracy of 82%, 100%, and 95%, respectively, whereas CH‐EUS had a sensitivity, specificity, and accuracy of 100%, 99%, and 99%, respectively. FB‐EUS‐based diagnosis of carcinomas based on tumor size and/or shape had a sensitivity, specificity, and accuracy of 61–87%, 71–88%, and 74–86%, respectively. Additional information regarding irregular vessel patterns in the vascular image and/or heterogeneous enhancement in the perfusion image on CH‐EUS increased the sensitivity, specificity, and accuracy for the diagnosis of carcinomas to 90%, 98%, and 96%, respectively. There was a significant difference between FB‐EUS and CH‐EUS in terms of carcinoma diagnosis.Conclusion
CH‐EUS was useful for the evaluation of localized gallbladder lesions. 相似文献107.
Takashi Kitagataya Goki Suda Kazunori Nagashima Takehiko Katsurada Koji Yamamoto Megumi Kimura Osamu Maehara Ren Yamada Taku Shigesawa Kazuharu Suzuki Akihisa Nakamura Masatsugu Ohara Machiko Umemura Naoki Kawagishi Masato Nakai Takuya Sho Mitsuteru Natsuizaka Kenichi Morikawa Koji Ogawa Shunsuke Ohnishi Yoshito Komatsu Hiroo Hata Satoshi Takeuchi Takashige Abe Jun Sakakibara-Konishi Takanori Teshima Akihiro Homma Naoya Sakamoto 《Journal of gastroenterology and hepatology》2020,35(10):1782-1788
108.
Adrenocorticotropic hormone cells and immunoreactive beta-endorphin cells in the human pituitary gland: normal and pathologic conditions studied by the peroxidase-labeled antibody method. 下载免费PDF全文
The comparative immunohistochemical localization of adrenocorticotropic hormone (ACTH) and beta-endorphin-like immunoreactivity (referred to as beta-endorphin) was studied in 16 human anterior pituitary glands from 6 normal adults, 4 normal fetuses, 1 stillborn infant, 2 anencephalic infants, 1 adult with Crooke's hyaline degeneration, and 2 patients with pituitary adenomas associated with Cushing's syndrome. Mirror sections were used in order to enable precise comparison of the same cells on the two consecutive tissue sections. In these normal and pathologic human anterior pituitary glands, ACTH and beta-endorphin were mostly localized in the same cells. In the normal adult pituitary glands, however, some ACTH cells were negative for beta-endorphin; and in one of the pituitary adenomas, some tumor cells were positive for only one hormone (beta-endorphin). These data suggest concomitant production of ACTH and beta-endorphin in the same cells and support the production of precursor molecules for these two hormones. The significance of ACTH-positive, beta-endorphin-negative normal cells and beta-endorphin-positive, ACTH-negative tumor cells is also discussed. 相似文献
109.
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
110.
Masatsugu Ohara Goki Suda Megumi Kimura Osamu Maehara Tomoe Shimazaki Taku Shigesawa Kazuharu Suzuki Akihisa Nakamura Naoki Kawagishi Masato Nakai Takuya Sho Mitsuteru Natsuizaka Kenichi Morikawa Koji Ogawa Tomoe Kobayashi Minoru Uebayashi Ryo Takagi Isao Yokota Tsuyoshi Shimamura Naoya Sakamoto 《Hepatology research》2020,50(6):715-725