全文获取类型
收费全文 | 4611篇 |
免费 | 251篇 |
国内免费 | 25篇 |
专业分类
耳鼻咽喉 | 34篇 |
儿科学 | 102篇 |
妇产科学 | 94篇 |
基础医学 | 544篇 |
口腔科学 | 150篇 |
临床医学 | 343篇 |
内科学 | 1249篇 |
皮肤病学 | 78篇 |
神经病学 | 313篇 |
特种医学 | 163篇 |
外科学 | 814篇 |
综合类 | 14篇 |
预防医学 | 165篇 |
眼科学 | 29篇 |
药学 | 278篇 |
中国医学 | 1篇 |
肿瘤学 | 516篇 |
出版年
2023年 | 40篇 |
2022年 | 78篇 |
2021年 | 117篇 |
2020年 | 56篇 |
2019年 | 82篇 |
2018年 | 96篇 |
2017年 | 88篇 |
2016年 | 85篇 |
2015年 | 80篇 |
2014年 | 120篇 |
2013年 | 160篇 |
2012年 | 266篇 |
2011年 | 278篇 |
2010年 | 150篇 |
2009年 | 118篇 |
2008年 | 241篇 |
2007年 | 298篇 |
2006年 | 266篇 |
2005年 | 313篇 |
2004年 | 259篇 |
2003年 | 229篇 |
2002年 | 211篇 |
2001年 | 94篇 |
2000年 | 117篇 |
1999年 | 128篇 |
1998年 | 44篇 |
1997年 | 31篇 |
1996年 | 27篇 |
1995年 | 39篇 |
1994年 | 34篇 |
1993年 | 36篇 |
1992年 | 68篇 |
1991年 | 73篇 |
1990年 | 54篇 |
1989年 | 46篇 |
1988年 | 56篇 |
1987年 | 49篇 |
1986年 | 47篇 |
1985年 | 32篇 |
1984年 | 27篇 |
1983年 | 20篇 |
1979年 | 22篇 |
1978年 | 17篇 |
1977年 | 12篇 |
1974年 | 14篇 |
1973年 | 14篇 |
1969年 | 14篇 |
1968年 | 14篇 |
1967年 | 15篇 |
1966年 | 21篇 |
排序方式: 共有4887条查询结果,搜索用时 15 毫秒
81.
Taka-Aki Matsuyama Shin Inoue Kaoru Tanno Mutsuki Makino Genyo Ogawa Tetsuo Sakai Youichi Kobayashi Takashi Katagiri Hidekazu Ota 《Europace : European pacing, arrhythmias, and cardiac electrophysiology》2006,8(11):977-979
We report a case, which we believe to be rare, of adenosine-sensitive atrial tachycardia (AT) originating from the mitral valve annulus. The patient, a 73-year-old woman, died of unrelated cause 4 years after radiofrequency (RF) ablation therapy. Histologically, fibrous replacement of atrial musculature by mature collagenous tissue produced by the RF current was observed at the left inferior atrioventricular junction. In serial sections that included the coronary sinus, two distinct nodal structures containing small, pale myocytes within the fibrous tissue matrix were identified around the region of the ablation lesion. Our case appears to be a unique representation of tissue that was associated with the occurrence and maintenance of AT. 相似文献
82.
Yushiro Endo Shin-ya Kawashiri Shimpei Morimoto Ayako Nishino Momoko Okamoto Sosuke Tsuji Ayuko Takatani Toshimasa Shimizu Remi Sumiyoshi Takashi Igawa Tomohiro Koga Naoki Iwamoto Kunihiro Ichinose Mami Tamai Hideki Nakamura Tomoki Origuchi Yukitaka Ueki Tamami Yoshitama Nobutaka Eiraku Naoki Matsuoka Akitomo Okada Keita Fujikawa Hideo Otsubo Hirokazu Takaoka Hiroaki Hamada Tomomi Tsuru Shuji Nagano Arinobu Yojiro Toshihiko Hidaka Yoshifumi Tada Atsushi Kawakami 《Medicine》2021,100(1)
We aimed to evaluate the utility of a simplified ultrasonography (US) scoring system, which is desired in daily clinical practice, among patients with rheumatoid arthritis (RA) receiving biological/targeted synthetic disease-modifying antirheumatic drugs (DMARDs).A total of 289 Japanese patients with RA who were started on tumor necrosis factor inhibitors, abatacept, tocilizumab, or Janus kinase inhibitors between June 2013 and April 2019 at one of the 15 participating rheumatology centers were reviewed. We performed US assessment of articular synovia over 22 joints among bilateral wrist and finger joints, and the 22-joint (22j)-GS and 22-joint (22j)-PD scores were evaluated as an indicator of US activity using the sum of the GS and PD scores, respectively.The top 6 most affected joints included the bilateral wrist and second/third metacarpophalangeal joints. Therefore, 6-joint (6j)-GS and -PD scores were defined as the sum of the GS and PD scores from the 6 synovial sites over the aforementioned 6 joints, respectively. Although the 22j- or 6j-US scores were significantly correlated with DAS28-ESR or -CRP scores, the correlations were weak. Conversely, 6j-US scores were significantly and strongly correlated with 22j-US scores not only at baseline but also after therapy initiation.Using a multicenter cohort data, our results indicated that a simplified US scoring system could be adequately tolerated during any disease course among patients with RA receiving biological/targeted synthetic DMARDs. 相似文献
83.
Kazuhiro Shirozu Hidekazu Setoguchi Kenzo Araki Taichi Ando Ken Yamaura 《American journal of infection control》2021,49(1):44-49
BackgroundPreviously, we found that an upward air current in the head area, induced by forced air warming (FAW), was completely counteracted by downward laminar airflow. However, this study did not include any consideration of the air-conditioner outlet layout (ACOL); hence, its impact remains unclear.MethodsThis study was performed in 2 operating rooms (ORs)—ISO classes 5 and 6, which are denoted as OR-5 and OR-6, respectively. Both ORs have distinct ACOLs. The cleanliness, or the number or ratio of shifting artificial particles was evaluated.ResultsDuring the first 5 minutes after particles generation, significantly more particles shifted into the surgical field in OR-5 when compared to OR-6 (13,587 [4,341-15,913] and 106 [41-338] particles/cubic foot, P < .0001). Notably, FAW did not increase the number of shifting particles in OR-6. The laminar airflow system fully counteracted the upward airflow caused by FAW in OR-6, where the ACOL covered the operating bed. However, this did not occur in OR-5, where the ACOL did not fully cover the operating bed.ConclusionsRegardless of cleanliness ability of OR, an ACOL that fully covers the operating bed can prevent upward airflow in the head area and reduce the number of artificial particles shifting into the surgical field, which are typically caused by FAW. 相似文献
84.
Yano H Suetake M Endo H Takayanagi R Numata M Ohyama K Sagai S Okitsu N Okamoto M Nishimura H Kobayashi T 《The Journal of infection》2005,51(4):e237-e240
Measles virus was isolated from the middle ear fluid (MEF) of two infant cases of acute otitis media (AOM) associated with measles. This is the first report on the isolation of measles virus from the MEF in patients with AOM, and possibility of the measles virus as a causative agent of AOM was suggested. 相似文献
85.
Kumagai S Kai Y Nagano M Zou B Kishimoto H Sasaki H 《Metabolic syndrome and related disorders》2005,3(3):213-220
The objective of this study was to examine the contribution of endurance fitness and visceral fat accumulation on the prevalence of metabolic syndrome in Japanese male patients with either an impaired glucose tolerance (IGT) or type 2 diabetes mellitus (DM). The subjects of this cross-sectional study consisted of 135 Japanese male patients with either IGT or type 2 DM who had not taken any medication or intervention. They were classified into three fitness categories (low, moderate, and high) based on the tertiles of their maximal oxygen uptake ( [Formula: see text] O(2)max) predicted by the Astrand nomogram using a cycle ergometer. Metabolic syndrome was defined based on the WHO criteria. The visceral fat area (VFA) was determined using a computed tomography scan. The age- and VFA-adjusted odds ratio was 3.49 (95% CI, 1.13-10.82) for subjects in the low fitness category in comparison to those in the high fitness category. We calculated the odds ratio for the prevalence of metabolic syndrome in the nine categories classified based on the three VFA and three [Formula: see text] (2)max levels. In Moderate- and Low- [Formula: see text] (2) max categories, the odds ratios increased in line with increases in the VFA level. The highest odds ratios were observed in the low fitness and high visceral fat group. In the High- [Formula: see text] O(2)max category, no significant odds ratios were observed in the Moderate- and High-VFA categories. These results indicate that a high degree of cardiorespiratory fitness positively contributed to the low prevalence of metabolic syndrome in Japanese male patients with IGT and type 2 DM. 相似文献
86.
Effect of L-dopa in young patients with hypertension 总被引:1,自引:0,他引:1
I Saito H Kawabe C Hasegawa Y Iwaida H Yamakawa T Saruta E Takeshita S Nagano T Sekihara 《Angiology》1991,42(9):691-695
The effects of L-dopa on blood pressure, heart rate, plasma renin activity, norepinephrine, epinephrine and prolactin were studied in a randomized single-blind trial in 36 patients with essential hypertension. In response to L-dopa, 250 mg administered orally, the blood pressure decreased significantly as compared with the results of placebo treatment. The heart rate and plasma norepinephrine and epinephrine were unchanged. The plasma renin activity and prolactin decreased as a result of L-dopa administration. The administration of a peripheral DA2 dopamine receptor blocker, domperidone (20 mg, orally) prevented the L-dopa-induced reduction in plasma prolactin but failed to block the fall in blood pressure and plasma renin activity. These results suggest that the blood pressure-lowering effect of L-dopa may be mediated through multiple sites involving D1 dopamine receptors, the central nervous system, and the renin-angiotensin system. 相似文献
87.
Myocardial bridging increases the risk of coronary spasm 总被引:2,自引:0,他引:2
Teragawa H Fukuda Y Matsuda K Hirao H Higashi Y Yamagata T Oshima T Matsuura H Chayama K 《Clinical cardiology》2003,26(8):377-383
BACKGROUND: Myocardial bridging (MB) has been associated with cardiac events. Whether coronary spasm is one factor contributing to those events is unknown. HYPOTHESIS: This study investigated whether the likelihood of coronary spasm is increased in patients with MB. METHODS: A spasm-provocation test was performed by infusing acetylcholine into the left coronary artery in 114 Japanese patients with chest pain. The test result was defined as positive when the diameter of the coronary artery was reduced by > or = 50% and ST-segment changes were documented. Myocardial bridging was defined as a > 15% reduction in coronary arterial diameter during systole after intracoronary injection of nitroglycerin. RESULTS: Myocardial bridging was identified in 41 patients (36%) and was located in the mid-segment of the left anterior descending coronary artery (LAD) in all patients. Patients with MB experienced coronary spasm more frequently than patients without MB (MB+: 73%; MB-: 40%, p = 0.0006). Furthermore, among patients with a positive spasm-provocation test, coronary spasm occurred more frequently in the mid-segment of the LAD in patients with MB than in those without MB (MB+: 73%; MB-: 45%, p = 0.0259). Multivariate regression analysis demonstrated that MB was a predictor of coronary spasm (odds ratio: 3.478, p = 0.0088). CONCLUSIONS: These results suggest that MB increases the risk of coronary spasm and that coronary spasm may be the proximate etiology of cardiac events associated with MB. 相似文献
88.
Levels of Rheumatoid Factor Isotypes, Metalloproteinase-3 and Tissue Inhibitor of Metalloproteinase-1 in Synovial Fluid from Various Arthritides 总被引:2,自引:0,他引:2
When synovial effusion is the only symptom, it is often difficult to make an exact diagnosis of the arthritic disease. To
distinguish various types of arthritis with synovial effusion, we measured the levels of matrix metalloproteinase-3 (MMP-3,
Stromelysin), tissue inhibitor of metalloproteinase-1 (TIMP-1) and rheumatoid factor (RF) isotypes in synovial fluid (SF)
from patients with rheumatoid arthritis (RA), osteoarthritis (OA), pyogenic arthritis (PA), pseudogouty arthritis (PG), gouty
arthritis (GA) and traumatic arthritis (TA). SF was aspirated from the knee joint or the ankle joint. Levels of IgG-, IgM-
and IgA-RF isotypes were measured by ELISA. Levels of MMP-3 and TIMP-1 in SF were simultaneously determined by a one-step
EIA system. Levels of IgG-RF, IgM-RF and MMP-3 in SF from RA patients were significantly higher than those in OA, PA, PG,
GA and TA. However, IgA-RF in SF from RA patients, when compared with PA and GA, did not show a significantly increased level.
In addition, TIMP-1 in SF from RA, when compared with PA and TA, also has not shown a significantly increased level. Therefore,
in addition to analysing clinical data, measurements of IgG-RF, IgM-RF and MMP-3 in SF may contribute in distinguishing RA
from other arthritic diseases.
Received: 18 January 1999 / Accepted: 15 June 1999 相似文献
89.
Cardiac free wall rupture in acute myocardial infarction: ameliorative effect of coronary reperfusion. 总被引:4,自引:0,他引:4
F Nakamura T Minamino Y Higashino H Ito K Fujii T Fujita M Nagano J Higaki T Ogihara 《Clinical cardiology》1992,15(4):244-250
To investigate the pathophysiology of cardiac free wall rupture (cardiac rupture) following acute myocardial infarction (AMI), and to clarify whether reperfusion therapy prevents cardiac rupture, 1,329 cases of AMI (conventional therapy group: 807 cases and reperfusion therapy group: 533 cases) were studied retrospectively. The overall incidence of cardiac rupture was 2.3% (2.7% in the conventional therapy group vs. 1.7% in the reperfusion therapy group). Patients with cardiac rupture were divided into two subgroups according to the time interval from the onset of AMI to cardiac rupture (early rupture less than or equal to 72 h and late rupture greater than or equal to 4 days). The indices of initial evolution of AMI was a significant risk of early cardiac rupture. The reperfusion therapy group showed significantly lower incidence of late rupture (0.4 vs. 1.5% in conventional therapy group; p less than 0.05). The incidence of cardiac rupture in the unsuccessful reperfusion therapy group was higher than that of the successful group (5.9% of 118 cases vs. 0.5% of 404 cases; p less than 0.05). It is concluded that the etiology of cardiac rupture following AMI cannot be explained by any single factor. Early rupture depends on the initial evolution of AMI, and early reperfusion and collateral flow prevent the late onset cardiac rupture. 相似文献
90.
Microscopic observation of chemical modification in sections using scanning acoustic microscopy 下载免费PDF全文
Katsutoshi Miura Yuki Egawa Toshiaki Moriki Hiroyuki Mineta Hidekazu Harada Satoshi Baba Seiji Yamamoto 《Pathology international》2015,65(7):355-366
A scanning acoustic microscope (SAM) calculates the speed of sound (SOS) through tissues and plots the data on the screen to form images. Hard tissues result in greater SOS; based on these differences in tissue properties regarding SOS, SAM can provide data on tissue elasticity. The present study evaluated whether tissue modifications, such as formalin fixation, periodic acid‐Schiff (PAS) reactions and protein degradation, changed the acoustic properties of the tissues and whether SAM could be a useful tool for following chemical changes in sections. The fixation process was observable by the increased SOS. During the PAS reaction, the glycosylation of tissues was characterized by an increased SOS. Mucous or glycogen distribution was visualized and was found to be statistically comparable among lesions and states. Protease digestion by pepsin led to a decreased SOS. Tissue sensitivity to proteases varied due to the stage, cause and duration of inflammation or ageing. Changes in acoustic properties were more sensitive than those in optical histology. SAM facilitates the visualisation of the time course or distribution of chemical modifications in tissue sections, thus aiding their comparison among tissues. SAM may be an effective tool for studying changes such as protein cross‐linkage, tissue repair and ageing. 相似文献