全文获取类型
收费全文 | 6849篇 |
免费 | 315篇 |
国内免费 | 34篇 |
专业分类
耳鼻咽喉 | 103篇 |
儿科学 | 147篇 |
妇产科学 | 82篇 |
基础医学 | 914篇 |
口腔科学 | 141篇 |
临床医学 | 369篇 |
内科学 | 1656篇 |
皮肤病学 | 222篇 |
神经病学 | 530篇 |
特种医学 | 252篇 |
外科学 | 1210篇 |
综合类 | 44篇 |
一般理论 | 1篇 |
预防医学 | 181篇 |
眼科学 | 142篇 |
药学 | 319篇 |
中国医学 | 12篇 |
肿瘤学 | 873篇 |
出版年
2023年 | 29篇 |
2022年 | 63篇 |
2021年 | 120篇 |
2020年 | 75篇 |
2019年 | 90篇 |
2018年 | 130篇 |
2017年 | 101篇 |
2016年 | 162篇 |
2015年 | 182篇 |
2014年 | 191篇 |
2013年 | 288篇 |
2012年 | 414篇 |
2011年 | 478篇 |
2010年 | 279篇 |
2009年 | 211篇 |
2008年 | 431篇 |
2007年 | 431篇 |
2006年 | 484篇 |
2005年 | 460篇 |
2004年 | 477篇 |
2003年 | 489篇 |
2002年 | 445篇 |
2001年 | 64篇 |
2000年 | 62篇 |
1999年 | 85篇 |
1998年 | 113篇 |
1997年 | 111篇 |
1996年 | 84篇 |
1995年 | 82篇 |
1994年 | 64篇 |
1993年 | 54篇 |
1992年 | 37篇 |
1991年 | 37篇 |
1990年 | 24篇 |
1989年 | 32篇 |
1988年 | 30篇 |
1987年 | 23篇 |
1986年 | 16篇 |
1985年 | 17篇 |
1984年 | 17篇 |
1983年 | 20篇 |
1982年 | 26篇 |
1981年 | 27篇 |
1980年 | 22篇 |
1979年 | 16篇 |
1978年 | 14篇 |
1976年 | 10篇 |
1975年 | 11篇 |
1974年 | 7篇 |
1971年 | 8篇 |
排序方式: 共有7198条查询结果,搜索用时 0 毫秒
61.
62.
The dorsolateral pontine nucleus (DLPN) is a major component of the cortico-ponto-cerebellar pathway that carries signals essential for smooth pursuit. This pathway also carries visual signals that could play a role in visually guided motor learning in the vestibular ocular reflex (VOR). However, there have been no previous studies that tested this possibility directly. The aim of this study was to determine the potential role of the DLPN in short-term VOR gain adaptation produced by viewing a scene through lenses placed in front of both eyes. In control experiments, adaptation of VOR gain was achieved by sinusoidal rotation (0.2 Hz, 30 degrees /s) for 2 h while the monkey viewed a stationary visual surround through either magnifying (x2) or minifying (x0.5) lenses. This led to increases (23-32%) or decreases (22-48%) of VOR gain as measured in complete darkness (VORd). We used injections of muscimol, a potent GABA(A) agonist (0.5 microl; 2%), to reversibly inactivate the DLPN, unilaterally, in three monkeys. After DLPN inactivation, initial acceleration of ipsilateral smooth-pursuit was reduced by 35-68%, and steady-state gain was reduced by 32-61%. Despite these significant deficits (P < 0.01) in ipsilesional smooth pursuit, the VOR during lens viewing was similar to that measured in preinjection control experiments. Similarly, after 2 h of adaptation, VORd gain was not significantly different (P > 0.61) from control adaptation values for either ipsi- or contralesional directions of head rotation. This was the case even though a stable ipsilesional smooth pursuit deficit persisted throughout the full adaptation period. Our results suggest that visual error signals for short-term adaptation of the VOR are derived from sources other than the DLPN perhaps including other basilar pontine nuclei and the accessory optic system. 相似文献
63.
Why the flexible cystoscope has not yet been widely introduced?: A questionnaire to Japanese urologists 总被引:1,自引:0,他引:1
Background : The flexible cystoscope has not been as widely accepted in the field of urology as in other fields. The results of this investigation provided implications for determining the reasons for the under-use of flexible cystoscopy as well as for the drawbacks of the flexible cystoscope.
Methods : We performed an investigation by sending a questionnaire to urologists asking them to compare the flexible cystoscope with the rigid cystoscope in order to determine why use of the former lags behind that of the latter.
Results : We received answers from 420 urologists. We classified the urologist into four groups according to their years of experience. We also classified patients, for whom flexible cystoscopy was carried out, into four groups. The majority of the urologists in all groups thought that the flexible cystoscope provided a small field of vision and rough images. Urologists thought that the flexible cystoscope was inferior to the rigid cystoscope in terms of manipulability in biopsy. However, doctors who examined many patients using flexible cystoscopy believed that it was advantageous in terms of decreasing the patients' pain and they have experienced no problem in clinical practice.
Conclusions : Lack of experience in using the flexible cystoscope appears to be the main reason for the negative impression it generates. The flexible cystoscope can be routinely used in place of the rigid counterpart for urological investigations and it is recommended that it be used more widely for the benefit of the patients. 相似文献
Methods : We performed an investigation by sending a questionnaire to urologists asking them to compare the flexible cystoscope with the rigid cystoscope in order to determine why use of the former lags behind that of the latter.
Results : We received answers from 420 urologists. We classified the urologist into four groups according to their years of experience. We also classified patients, for whom flexible cystoscopy was carried out, into four groups. The majority of the urologists in all groups thought that the flexible cystoscope provided a small field of vision and rough images. Urologists thought that the flexible cystoscope was inferior to the rigid cystoscope in terms of manipulability in biopsy. However, doctors who examined many patients using flexible cystoscopy believed that it was advantageous in terms of decreasing the patients' pain and they have experienced no problem in clinical practice.
Conclusions : Lack of experience in using the flexible cystoscope appears to be the main reason for the negative impression it generates. The flexible cystoscope can be routinely used in place of the rigid counterpart for urological investigations and it is recommended that it be used more widely for the benefit of the patients. 相似文献
64.
Masaki Kaibori Shoji Kubo Hiroaki Nagano Michihiro Hayashi Seiji Haji Takuya Nakai Morihiko Ishizaki Kosuke Matsui Takahiro Uenishi Shigekazu Takemura Hiroshi Wada Shigeru Marubashi Koji Komeda Fumitoshi Hirokawa Yasuyuki Nakata Kazuhisa Uchiyama A-Hon Kwon 《World journal of surgery》2013,37(4):820-828
Background
The present study aimed to clarify the clinicopathologic features of long-term disease-fee survival after resection of hepatocellular carcinoma (HCC).Methods
This retrospective study identified 940 patients who underwent curative resection of HCC between 1991 and 2000 at five university hospitals. Seventy-four patients with 10 years of recurrence-free survival were identified and followed up. They were divided into two groups, 60 recurrence-free and 14 with recurrence after a 10-year recurrence-free period.Results
Overall survival rates of recurrence and non-recurrence groups were 68 and 91 % at 16 years, and 34 and 91 % at 20 years (p = 0.02), respectively. There were five (36 %), and two deaths (3 %), respectively, after 10 recurrence-free years. A second resection for recurrence was performed in four patients (29 %), and mean survival was 15.3 years after the first hepatectomy. Although three patients in the non-recurrence group (5 %) developed esophageal and/or gastric varices, seven patients in the recurrence group (50 %) developed varices during 10 years (p < 0.0001). In multivariate analysis, preoperative and 10-year platelet count was identified as a favorable independent factor for maintained recurrence-free survival after a 10-year recurrence-free period following curative hepatic resection of HCC.Conclusions
Recurrence of HCC may occur even after a 10-year recurrence-free period. Long-term follow-up after resection of HCC is important, and should be life-long. Patients with higher preoperative and 10-year platelet counts are more likely to have long-term survival after resection. A low platelet count, related to the degree of liver fibrosis, is a risk factor for recurrence and survival of HCC after curative resection. 相似文献65.
Tomiguchi S Kumita S Hashimoto J Inoue T Nomura Y Emoto J Nakajima K Nishimura T 《Kaku igaku. The Japanese journal of nuclear medicine》2002,39(1):37-46
The aim of this study was to evaluate the clinical usefulness of attenuation and scatter correction (AC, SC) on a 201Tl myocardial single-photon emission computed tomography (201Tl SPECT) as a multi-center trial. With a dual-detecter and a triple-detector SPECT systems with a 99mTc transmission source, simultaneous transmission/emission tomography (TCT/ECT) was performed on 38 patients with angiographically coronary heart disease (CHD) and 26 patients without evidence of CHD. Stress and delayed attenuation and scatter corrected images (SAC) and uncorrected images (NC) were reconstructed. On NC images of normal cases, influence of attenuation was greater in male than female. In comparison of 201Tl distribution between male and female, significant decrease in 201Tl activity was observed in the inferoposterior wall in male and that was observed in the anterobasal wall of the left myocardium in female. Such a difference in 201Tl distribution between male and female disappeared on SAC images. On the diagnostic performance for the identification of CHD, SAC images demonstrated improved specificity and accuracy values in the right coronary arterial territory (RCA) with visual analysis statistically. Sensitivity value in the RCA was also improved, but it was not statistically significant. Sensitivity value in the left circumflex arterial territory (LCX) increased without decrease in specificity value on SAC images. In the left anterior descending arterial territory (LAD), sensitivity value increased on SAC images. Although specificity value decreased on SAC images in LAD territory, it was not statistically significant. The difference in 201Tl distribution between male and female is improved in normal cases by attenuation and scatter correction on 201Tl myocardial SPECT. Diagnostic performance of CHD is also improved by attenuation and scatter correction, especially in territories of which specificity in assessing the absence of disease have been suboptimal. In conclusion, attenuation and scatter correction on 201Tl myocardial SPECT is considered to be clinically useful. 相似文献
66.
Ultrasonographic evaluation of small nodules in the peripheral lung during video-assisted thoracic surgery (VATS). 总被引:1,自引:0,他引:1
Seiji Matsumoto Toshiki Hirata Eiji Ogawa Tatsuo Fukuse Hiroyuki Ueda Takashi Koyama Takayuki Nakamura Hiromi Wada 《European journal of cardio-thoracic surgery》2004,26(3):469-473
OBJECTIVE: We examined the possibility of intraoperative ultrasonography during video-assisted thoracic surgery (VATS) to localize and make a qualitative diagnosis of small peripheral pulmonary nodules. METHODS: Ultrasonography during VATS and conventional thoractomy was performed on 25 and 18 nodules, respectively, all which were localized in the peripheral lung, were less than 30 mm in diameter and for which there was no definitive diagnosis. RESULTS: All 25 nodules, including 10 invisible but palpable and three both invisible and non-palpable, could be localized by ultrasonography during VATS. If nodules were located less than 15 mm from the pleural surface, ultrasonography during VATS could detect nodules 10 mm or less in diameter. The rate of malignant tumors among 11 of 12 pulmonary nodules (91.6%) showing both heterogeneous and ill-defined patterns was significantly higher than 6 of 16 nodules (37.5%) showing both homogeneous and well-defined patterns on ultrasonography. CONCLUSIONS: Our study suggested that ultrasonography during VATS is useful for the detection of peripheral pulmonary nodules, even when they are not identified on video images or palpation, and may enable a differential diagnosis between malignant and non-malignant lesions. 相似文献
67.
Ca2+ sensitization in contraction of human bladder smooth muscle 总被引:13,自引:0,他引:13
Takahashi R Nishimura J Hirano K Seki N Naito S Kanaide H 《The Journal of urology》2004,172(2):748-752
PURPOSE: The role of Ca2+ sensitization in the contraction of human bladder urinary smooth muscle (UBSM) was investigated. MATERIALS AND METHODS: Simultaneous measurements of intracellular Ca2+ concentration ([Ca2+]i) and tension in fura-2 loaded intact strips and receptor coupled strips permeabilized with alpha-toxin were applied. Protein expressions was confirmed by Western blot analysis. RESULTS: In intact fura-2 loaded strips 1 microM carbachol (CCh) induced a greater contraction and a lower [Ca2+]i elevation than that induced by 60 mM K depolarization. In alpha-toxin permeabilized strips 1 microM CCh induced contraction at constant [Ca2+]i and produced a leftward shift in the [Ca2+]i-tension relationship. RhoA, Rho-associated kinase (ROCK) I, ROCK II and CPI-17 proteins were expressed in human UBSM. In intact fura-2 loaded strips the application of 3 microM Y-27632, a ROCK inhibitor, or 3 microM bisindolylmaleimide I (GF109203X), a protein kinase C inhibitor, during the sustained phase of contraction induced by 1 microM CCh induced relaxation without changing [Ca2+]i. In alpha-toxin permeabilized strips the application of 3 microM Y-27632 or 3 microM GF109203X during the sustained contraction induced by 0.3 microM Ca plus 10 microM guanosine triphosphate and 1 microM CCh induced relaxation at constant [Ca2+]i. CONCLUSIONS: These results indicate that in human UBSM CCh induces contraction, not only by increasing [Ca2+]i, but also by increasing the Ca2+ sensitivity of the contractile apparatus in a ROCK and protein kinase C dependent manner. Antagonism of Ca2+ sensitization pathways may represent an alternative target in the treatment of overactive bladder. 相似文献
68.
Takehiko Matsushita Hiroshi Sasaki Koji Takayama Kazunari Ishida Tomoyuki Matsumoto Seiji Kubo Tokio Matsuzaki Kotaro Nishida Masahiro Kurosaka Ryosuke Kuroda 《Journal of orthopaedic research》2013,31(4):531-537
In this study, we examined the effects of overexpression of SIRT1 on IL‐1β‐induced gene expression changes in human chondrocytes to explore a protective role of SIRT1 in human chondrocytes. SIRT1 was overexpressed in human chondrocytes by expression plasmid under stimulation with IL‐1β. SIRT1 was also inhibited by siRNA under stimulation with IL‐1β. Gene expression changes were examined by real‐time PCR. The interaction of SIRT1 and p65 (NF‐κB) were examined by Western blotting. SIRT1, MMP‐13, and ADAMTS‐5 expressions in human cartilage were examined by immunohistochemistry. IL‐1β stimulation significantly up‐regulated MMP‐1, 2, 9, and 13 and ADAMTS‐5. Overexpression of SIRT1 significantly inhibited the up‐regulation of those genes caused by IL‐1β while the inhibition of SIRT1 further increased them. In addition, the overexpression of SIRT1 markedly reduced the IL‐1β‐induced acetylation of p65. SIRT1 expression was clearly detected in the non‐OA cartilage while MMP‐13 and ADAMTS‐5 were undetectable. In contrast, in the OA cartilage, SIRT1 expression was decreased while MMP‐13 and ADAMTS‐5 were increased. Our observations suggested that SIRT1 can play a protective role by suppressing IL‐1β‐induced expressions of cartilage‐degrading enzymes partially through the modulation of the NF‐κB pathway. SIRT1 overexpression might be a new therapeutic approach for OA. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 31: 531–537, 2013 相似文献
69.
Tomoyuki Yano M.D. Mutsumi Okazaki M.D. Ph.D. Runa Kawaguchi M.D. Nobuko Suesada M.D. Kentaro Tanaka M.D. Seiji Kishimoto M.D. Ph.D. 《Microsurgery》2013,33(6):487-490
Tongue reconstruction was performed using a deep inferior epigastric perforator (DIEP) free flap in a 6‐year‐old girl with undifferentiated sarcoma of the tongue. After hemi‐glossectomy with upper neck dissection, a 3‐lobed DIEP free flap was used for the reconstruction. Donor site was closed primarily with suturing umbilicus in proper position. No flap loss, leakage, or infection occurred. Postoperatively, the patient was able to consume a normal diet without difficulty or aspiration and displayed good speech function. No donor site morbidity, e.g., herniation or bulging, was observed, and the patient was able to perform their normal daily activities. DIEP flaps provide a pliable skin paddle, an adequate amount of adipose tissue, and reduced donor site morbidity, even in children. We did not have any difficulty harvesting the DIEP flap or with the microvascular anastomosis. We consider DIEP free flaps to be the ideal option for pediatric tongue reconstruction. © 2013 Wiley Periodicals, Inc. Microsurgery 33:487–490, 2013. 相似文献
70.
Sugo H Ishizaki Y Yoshimoto J Imamura H Kawasaki S 《Annals of surgical oncology》2012,19(7):2238-2245