全文获取类型
收费全文 | 3308篇 |
免费 | 145篇 |
国内免费 | 21篇 |
专业分类
耳鼻咽喉 | 13篇 |
儿科学 | 41篇 |
妇产科学 | 20篇 |
基础医学 | 386篇 |
口腔科学 | 53篇 |
临床医学 | 216篇 |
内科学 | 858篇 |
皮肤病学 | 26篇 |
神经病学 | 229篇 |
特种医学 | 118篇 |
外科学 | 690篇 |
综合类 | 10篇 |
预防医学 | 63篇 |
眼科学 | 97篇 |
药学 | 289篇 |
中国医学 | 6篇 |
肿瘤学 | 359篇 |
出版年
2023年 | 38篇 |
2022年 | 43篇 |
2021年 | 83篇 |
2020年 | 57篇 |
2019年 | 65篇 |
2018年 | 53篇 |
2017年 | 64篇 |
2016年 | 73篇 |
2015年 | 84篇 |
2014年 | 103篇 |
2013年 | 134篇 |
2012年 | 219篇 |
2011年 | 217篇 |
2010年 | 104篇 |
2009年 | 106篇 |
2008年 | 167篇 |
2007年 | 179篇 |
2006年 | 205篇 |
2005年 | 196篇 |
2004年 | 177篇 |
2003年 | 199篇 |
2002年 | 182篇 |
2001年 | 78篇 |
2000年 | 76篇 |
1999年 | 79篇 |
1998年 | 39篇 |
1997年 | 49篇 |
1996年 | 25篇 |
1995年 | 16篇 |
1994年 | 26篇 |
1993年 | 19篇 |
1992年 | 41篇 |
1991年 | 31篇 |
1990年 | 27篇 |
1989年 | 26篇 |
1988年 | 19篇 |
1987年 | 20篇 |
1986年 | 21篇 |
1985年 | 36篇 |
1984年 | 16篇 |
1983年 | 17篇 |
1982年 | 11篇 |
1981年 | 4篇 |
1980年 | 5篇 |
1979年 | 8篇 |
1978年 | 5篇 |
1977年 | 3篇 |
1975年 | 3篇 |
1972年 | 4篇 |
1971年 | 10篇 |
排序方式: 共有3474条查询结果,搜索用时 0 毫秒
31.
Shinohara K Shoji T Tsujimoto Y Kimoto E Tahara H Koyama H Emoto M Ishimura E Miki T Tabata T Nishizawa Y 《Kidney international》2004,65(3):936-943
BACKGROUND: Hemodialysis patients have advanced arterial wall stiffening as shown by increased aortic pulse wave velocity (PWV), an independent predictor of cardiovascular mortality. We compared aortic PWV of uremic patients before starting hemodialysis treatment with that of patients on maintenance hemodialysis. METHODS: The subjects were 71 patients with end-stage renal disease (ESRD) before starting hemodialysis (predialysis group), 144 patients on maintenance hemodialysis, and 140 healthy control subjects. These three groups were all nondiabetic and comparable in age and gender. RESULTS: The hemodialysis group had greater aortic PWV than the healthy subjects, and the predialysis patients showed a still higher value than the hemodialysis group. Multiple regression analysis in the total subjects revealed that the presence of renal failure was significantly associated with increased aortic PWV independent of age, gender, blood pressure, body mass index, smoking, high-density lipoprotein (HDL) and nonhigh-density lipoprotein (non-HDL) cholesterol levels. In contrast, hemodialysis was associated with decreased aortic PWV independent of renal failure and the other factors. Further analyses in the combined uremic patients again indicated the favorable impact of hemodialysis on aortic PWV independent of the classical risk factors, use of antihypertensive medications, including angiotensin-converting enzyme inhibitors and calcium channel blockers, hematocrit, serum calcium, phosphorus, parathyroid hormone levels, and the use of calcium carbonate. Insulin resistance using homeostasis model assessment (HOMA-IR) was associated with increased aortic PWV. CONCLUSION: Aortic stiffening was present in uremic patients before starting hemodialysis treatment and no adverse effect of hemodialysis was observed, suggesting the important roles of renal failure and/or metabolic alterations secondary to renal failure in arterial stiffness in patients with uremia. 相似文献
32.
Effect of early wound excision on changes in plasma nitric oxide and endothelin-1 level after burn injury: an experimental study in rats 总被引:4,自引:0,他引:4
Chen X Soejima K Nozaki M Tanabe Y Sakurai H 《Burns : journal of the International Society for Burn Injuries》2004,30(8):793-797
The purpose of this study was to evaluate effects of early wound excision on changes in NO and endothelin-1 (ET-1) level in the plasma after extensive burn injury. The effects on vascular permeability and hepatic blood flow (HBF) were also assessed. Male Wistar rats were used for this study. A 30% total body surface area (TBSA) third-degree burn was made on the back. Then animals were divided into four groups. Burn group (n = 13), burn alone; infusion group (n = 13), burn injury and fluid resuscitation; early excision group (n = 13), burn injury, total wound excision at 30 min after the injury followed with immediate allogenic skin graft and fluid resuscitation; and the sham group (n = 15). The sham group and the early excision group did not show significant changes in the NO and ET-1 level in plasma during experimental period, while the burn group and the infusion group showed significant increase in the NO and ET-1. The early excision group also did not show hypovolemia, and the significant decrease in the HBF. These data suggest that the increased NO and ET-1 in plasma following thermal injury were originated from burned tissue and the removal of these injured tissue has beneficial effect on the vascular permeability and the changes in HBF. 相似文献
33.
Yoshida S Kawakami S Komai Y Tadokoro M Yokoyama M Saito K Kageyama Y Kihara K 《Nihon Hinyōkika Gakkai zasshi. The japanese journal of urology》2004,95(5):718-721
A 46-year-old man was presented with a firm mass of the spermatic cord. He underwent left radical orchiectomy with clinical diagnosis of spermatic cord tumor. The pathological examination revealed leiomyosarcoma (3.6 x 2.7 x 1.0 cm, pT1bN0M0; 5th TNM, Stage IA; 5th AJCC). He is free of disease 3 year postoperatively. 相似文献
34.
35.
Terazawa S Tajima K Takami Y Tanaka K Okada N Usui A Ueda Y 《Journal of cardiac surgery》2012,27(3):281-287
Abstract Background: Advances in percutaneous coronary intervention (PCI) using drug‐eluting stents (DES) have impacted clinical practice. However, the efficacy of DES for dialysis patients still remains controversial. This study compares the early and long‐term clinical outcomes of coronary artery bypass grafting (CABG) and PCI with DES in dialysis patients. Methods: A retrospective review was performed in 125 dialysis patients treated between 2004 and 2007. Fifty‐eight patients underwent CABG and 67 underwent PCI with DES. The overall death, cardiac death, and cardiac‐related event rates were analyzed using the Kaplan‐Meier method. For the risk‐adjusted comparisons, multivariable logistic and Cox regression analyses were used. Results: The preoperative characteristics of the patients were similar except for the ejection fraction (p = 0.002) and the number of diseased vessels (p < 0.001). The 30‐day mortality was 0 in both groups. The overall survival rates at one, three, and five years were 84.2%, 64.7%, and 56.2% in CABG group and 88.2%, 75.5%, and 61.7% in DES group, respectively (p = 0.202). The rates of freedom from cardiac‐related events at one, three, and five years were 76.6%, 68.1%, and 48.6%, and 63.0%, 31.4%, and 0% in CABG and DES groups (p < 0.001), respectively, including seven (10%) late thromboses in the DES group. Although the risk‐adjusted analysis showed no significant difference for overall and cardiac death rates, the rates of cardiac‐related events and graft/stent failure were significantly higher in the DES group. Conclusions: CABG is superior for revascularization in dialysis patients compared with PCI using DES in terms of freedom from cardiac‐related events. (J Card Surg 2012;27:281‐287) 相似文献
36.
Surgery for pulmonary metastases from colorectal cancer 总被引:2,自引:0,他引:2
Masahiko Higashiyama Ken Kodama Naozumi Higaki Koji Takami Kohei Murata Masao Kameyama Hideoki Yokouchi 《The Japanese Journal of Thoracic and Cardiovascular Surgery》2003,51(7):289-296
OBJECTIVE: Several investigators have analyzed prognostic factors of surgical treatment for pulmonary metastases from colorectal cancer, but the results remain inconclusive. This study was performed to determine the prognostic implications of the prethoracotomy serum level of carcinoembryonic antigen (CEA) in relation to the postthoracotomy recurrent pattern among patients with this disease. METHODS: A retrospective analysis of prognostic factors was undertaken in 100 patients who had consecutively undergone initial surgical resection for pulmonary metastases of colorectal origin. RESULTS: The overall 3- and 5-year survival rates were 62.2% and 49.4%, respectively. Univariate analysis revealed that the prethoracotomy serum CEA level and operative curability were strongly associated with prognosis, while in multivariate analysis, only the prethoracotomy serum CEA level was a significant prognostic indicator. Patients with a high level of prethoracotomy serum CEA more frequently exhibited recurrence in extrathoracic sites, especially in the brain. CONCLUSION: Before thoracotomy for pulmonary metastases from colorectal cancer, the serum CEA level was the most useful prognostic factor. Patients with elevated serum CEA level should undergo a careful prethoracotomy systemic survey and postthoracotomy follow-up for extrathoracic metastases, in particular brain metastases, and an appropriate combined therapeutic modality should be considered. 相似文献
37.
Akira Sato Kazutaka Aonuma Toshihiro Nozato Yukio Sekiguchi Osamu Okazaki Kazuo Kubota Michiaki Hiroe 《Journal of nuclear cardiology》2008,15(5):671-679
Background. This study was designed to assess the influence of coronary endothelial function and the serial changes of dual myocardial
single photon emission computed tomography (SPECT) imaging in transient left ventricular (LV) apical ballooning.
Methods and Results. We evaluated 35 consecutive patients (8 men and 27 women; mean age, 71 ±13 years) with transient LV apical ballooning. All
patients underwent coronary angiography with acetylcholine provocation 1 month after onset. Iodine 123 β-methyl-p-iodophenyl-pentadecanoic acid (BMIPP) and thallium 201 dual myocardial SPECT was serially performed on day 1 of admission
and 1 month and 6 months later. In 8 of 35 patients (23%), epicardial coronary spasm was induced by acetylcholine infusion.
At the peak acetylcholine dose (100 μg), diffuse coronary vasoconstriction developed in 19 of 35 patients (54%). Of 19 patients,
13 had diffuse coronary vasoconstriction with chest pain and ST-segment depression. The total defect score of I-123 BMIPP
and Tl-201 SPECT showed marked perfusion-fatty acid metabolic mismatches (13.7±3.6 vs 8.7±2.3, P<.001) at the LV apex during the acute phase but few mismatched areas (2.1±1.1 vs 1.5±1.4, P = not significant) at 6 months.
Conclusions. Transient LV apical ballooning might be caused by stress-induced coronary epicardial spasm or endothelial dysfunction, resulting
in myocardial stunning. 相似文献
38.
Efficacy of dynamic CT perfusion imaging in conjunction with three dimensional CT angiography for the evaluation of acute ischemic stroke 总被引:2,自引:0,他引:2
Nakaguchi H Teraoka A Adachi S Yanagibashi K 《No shinkei geka. Neurological surgery》2003,31(1):17-25
BACKGROUND AND PURPOSE: Through the use of a high-speed spiral CT scanner (GEMedical HiSpeedZX/i), CT/P/A technique, where conventional CT, CT perfusion imaging (CTP) and CT angiography (CTA) are consecutively performed, can now be performed with an imaging time of 90 seconds and a total contrast medium volume of 100 ml. A prospective clinical study was performed to ascertain the effectiveness of CT/P/A in diagnosing acute ischemic strokes. METHODS: 29 consecutive patients of Teraoka Memorial Hospital suspected of suffering from the occlusion or constriction of cerebral arteries and who underwent CT/P/A within 3 hours from the onset served as subjects. The sensitivity, specificity, or Odds ratio of CTP and CTA in detecting lesions that caused cerebral infarction was calculated. RESULTS: CTP detected a hypoperfusion area with a sensitivity, specificity, and Odds ratio of 80%, 64%, and 7.2. The sensitivity in lobar infarcts, white matter infarcts, basal ganglia infarcts, and brainstem infarcts was 100%, 100%, 100%, 0% (p = 0.0022). The sensitivity and Odds ratio of CT/P/A in cerebral infarcts differed according to the diameter of the infarcts. That with infarcts of 10 mm or more was 91%, 20. That with infarcts smaller than 10 mm was 50%, 2. CTA detected arterial lesions that caused cerebral ischemic attack with a sensitivity of 94% and specificity of 90%. The examination time for CT/P/A was 18 minutes, total radiation time being 90 seconds. CONCLUSIONS: Although CT/P/A was ineffective for the diagnosis of brainstem infarcts and lesions smaller than 10 mm, CT/P/A was useful in detecting moderate-sized hypoperfusion areas and arterial lesions three-dimensionally before an infarct is completed. 相似文献
39.
Tetsuhiko Mimura Shigeharu Uchiyama Masanori Hayashi Kazutaka Uemura Hideki Moriya Hiroyuki Kato 《Journal of orthopaedic science》2017,22(6):1026-1030
Background
During the surgery for a distal radius fracture, we encountered a large anomalous muscle lying across the distal radius. The muscle was identified as a flexor carpi radialis brevis muscle (FCRB), based on its location, function, and innervation. This experience led us to clarify its prevalence in living subjects and alert surgeons of its presence.Methods
We reviewed wrist MRI scans of 515 hands of 379 patients with carpal tunnel syndrome (CTS). The prevalence of the FCRB was calculated. The cross sectional area (CSA) of the FCRB was compared with that of the hypothenar muscles. Signal intensity and fat infiltration of the FCRB were assessed using semiquantitative methods. The anterior compartment ratio (CSA of the anterior compartment of the forearm was divided by CSA of the forearm. CSA of the FCRB was excluded for measurement) was compared between patients with and without FCRB.Results
We found seven hands of six patients (1.6%) with a FCRB. All of these tendons were inserted into the second metacarpal base. CSA of FCRB was smaller than that of the hypothenar muscles. Semiquantitative assessment revealed normal signal intensities of the FCRB compared with those of other muscles. The anterior compartment ratio was smaller in patients with FCRB than without FCRB. None of the FCRB in our series demonstrated any sign of tendinitis on MRI. Furthermore, the postoperative clinical course for those patients was uneventful.Conclusions
Prevalence of FCRB in patients with CTS was 1.6%. FCRB should function as a wrist flexor. Its strength varied according to the individuals but was not greater than that of the hypothenar muscles. It is still unclear if the FCRB could cause the development of CTS. However, it was found that the FCRB could be a mass which occupies and narrows the anterior compartment. 相似文献40.
Nahoko Kawamura Makoto Tomita Midori Hasegawa Kazutaka Murakami Kunihiro Nabeshima Hiroko Kushimoto Masami Kasugai Kazuo Takahashi Yoshiyuki Hiki Tsuneo Kinukawa Nobumitsu Usuda Satoshi Sugiyama 《Clinical transplantation》2005,19(S14):27-31
Abstract: The effects of antibody-mediated rejection on long-term graft survival have not been fully investigated. The aim of this study is to clarify the influence on long-term survival of deposition of the complement split product C4d in allografts using polyclonal anti-C4d antibody. Inclusion criteria were recipients who underwent graft biopsy during acute deterioration of graft function within the first 2 yr after transplantation. Patients whose graft did not survive more than 1 yr and who received graft from an human leucocyte antigen (HLA)-identical sibling or an ABO-incompatible donor were excluded. Among the 92 recipients investigated, 22 (23.9%) had peritubular capillary C4d deposition, 15 (16.3%) had glomerular capillary C4d deposition and seven (7.6%) had both peritubular and glomerular capillary C4d deposition. Twenty of these 22 patients revealed acute cellular rejection, including borderline changes. There was no significant relationship between pathological severity of acute rejection and presence or absence of peritubular capillary C4d deposition. Graft survival was inferior in patients with peritubular capillary C4d deposition to that in patients without C4d deposition (p = 0.0419). Graft survival in patients with glomerular C4d deposition did not differ from that in patients without C4d deposition. In conclusion, C4d deposition in peritubular capillaries has a substantial impact on long-term graft survival. 相似文献