全文获取类型
收费全文 | 5376篇 |
免费 | 269篇 |
国内免费 | 23篇 |
专业分类
耳鼻咽喉 | 31篇 |
儿科学 | 73篇 |
妇产科学 | 48篇 |
基础医学 | 648篇 |
口腔科学 | 135篇 |
临床医学 | 361篇 |
内科学 | 1633篇 |
皮肤病学 | 86篇 |
神经病学 | 245篇 |
特种医学 | 191篇 |
外科学 | 1015篇 |
综合类 | 15篇 |
预防医学 | 294篇 |
眼科学 | 55篇 |
药学 | 389篇 |
中国医学 | 2篇 |
肿瘤学 | 447篇 |
出版年
2023年 | 39篇 |
2022年 | 59篇 |
2021年 | 83篇 |
2020年 | 45篇 |
2019年 | 75篇 |
2018年 | 78篇 |
2017年 | 74篇 |
2016年 | 71篇 |
2015年 | 93篇 |
2014年 | 157篇 |
2013年 | 154篇 |
2012年 | 287篇 |
2011年 | 264篇 |
2010年 | 173篇 |
2009年 | 139篇 |
2008年 | 257篇 |
2007年 | 336篇 |
2006年 | 320篇 |
2005年 | 338篇 |
2004年 | 303篇 |
2003年 | 296篇 |
2002年 | 310篇 |
2001年 | 172篇 |
2000年 | 138篇 |
1999年 | 133篇 |
1998年 | 76篇 |
1997年 | 64篇 |
1996年 | 49篇 |
1995年 | 43篇 |
1994年 | 30篇 |
1993年 | 28篇 |
1992年 | 98篇 |
1991年 | 69篇 |
1990年 | 73篇 |
1989年 | 66篇 |
1988年 | 79篇 |
1987年 | 50篇 |
1986年 | 72篇 |
1985年 | 52篇 |
1984年 | 39篇 |
1983年 | 39篇 |
1979年 | 36篇 |
1978年 | 21篇 |
1977年 | 21篇 |
1975年 | 21篇 |
1974年 | 31篇 |
1973年 | 22篇 |
1969年 | 18篇 |
1968年 | 22篇 |
1967年 | 21篇 |
排序方式: 共有5668条查询结果,搜索用时 15 毫秒
61.
Tc-99m PMT hepatobiliary scintigraphy in the differential diagnosis of extrahepatic metastases and hepatocellular carcinoma 总被引:1,自引:0,他引:1
Mochizuki T Tsuda T Sugawara Y Tanaka H Kikuchi T Miyagawa M Shimizu K Murase K Iuchi H Onji M Ikezoe J 《Clinical nuclear medicine》2000,25(12):991-995
PURPOSE: The authors evaluated the utility of hepatobiliary scintigraphy for tissue characterization of extrahepatic metastases from hepatocellular carcinoma (HCC) using Tc-99m N-pyrydoxyl-5-methyltriptophane (Tc-99m PMT). METHODS: We examined 13 patients with HCC (29 extrahepatic metastases and 3 benign bone lesions) and 5 patients with other cancers (15 extrahepatic metastases). Thirty minutes to 6 hours after intravenous administration of Tc-99m PMT, planar (all 47 lesions) and SPECT (42 lesions) images were obtained. Accumulation of Tc-99m PMT in the lesion was evaluated visually by comparing bone scintigraphy, computed tomography, magnetic resonance imaging, or all of these. RESULTS: Findings were positive in 12 of 13 patients with HCC and extrahepatic metastases (16 of 29 on planar imaging and 21 of 26 on SPECT). Findings in all three benign bone lesions and 15 metastatic lesions from non-HCC primary lesions were negative (0 of 18 on planar imaging, 0 of 16 on SPECT). There were no false-positive findings in these lesions. Lesion-by-lesion sensitivity, specificity, accuracy, and positive and negative predictive values were 55%, 100%, 72%, 100%, and 58% by planar imaging and 81%, 100%, 88%, 100%, and 76% by SPECT, respectively. CONCLUSIONS: Because of the high specificity and reasonable sensitivity, Tc-99m PMT appears to be useful for the differential diagnosis of extrahepatic metastases from HCC. SPECT improves the detectability of small or faint accumulation in metastases from HCC. 相似文献
62.
Orihashi K Matsuura Y Sueda T Watari M Okada K Sugawara Y Ishii O 《The Journal of thoracic and cardiovascular surgery》2000,120(4):672-678
OBJECTIVE: Transesophageal echocardiography was applied to visualizing endovascular procedures during transaortic stent grafting for aneurysm and dissection at the distal arch, and the use of transesophageal echocardiography was evaluated. METHODS: The 16 consecutive patients (13 with aneurysms and 3 with dissections) were examined. Transesophageal echocardiography was used for (1) determining graft size, (2) guiding placement of the catheter in the descending aorta at an appropriate position without intimal damage, (3) guiding graft tailoring with a balloon catheter, and (4) examining the results after the procedures. RESULTS: Visualization was disturbed in one patient who had undergone a previous operation. The graft size was appropriate, except in one patient as a result of underestimation. Transesophageal echocardiography was helpful for navigating the graft placement and tailoring without intimal damage. We tried to keep a distance from the diaphragm of 9 cm and an attachment portion of 4 cm. In one patient the graft was placed too distally (7 cm from the diaphragm) to cover the thick atheromatous plaque with the graft. The patient had paraplegia. Transesophageal echocardiographic assessment of endoleak and thromboexclusion was identical to that of postoperative computed tomography or angiography, with a sensitivity of 100% (1/1) and a specificity of 100% (13/13). Leakage at the proximal suture and graft kinking were found in 3 patients. Successful thromboexclusion by transesophageal echocardiographic assessment (13 patients) was predictive of subsequent regression of aneurysm and dissection in the midterm follow-up period: there was complete and partial regression in 5 and 8 patients, respectively. CONCLUSION: Transesophageal echocardiography enables echocardiography-assisted operations with secure step-by-step endoluminal procedures and immediate intraoperative assessment, which is predictive of the postoperative results. 相似文献
63.
Tomohiro Komatsu Makoto Ayaori Harumi Uto-Kondo Katsumi Hayashi Katsumi Tamura Hiroki Sato Makoto Sasaki Takafumi Nishida Shunichi Takiguchi Emi Yakushiji Kazuhiro Nakaya Katsunori Ikewaki 《Journal of atherosclerosis and thrombosis》2022,29(5):775
Aims: Inflammation is involved in various processes of atherosclerosis development. Serum C-reactive protein (CRP) levels, a predictor for cardiovascular risk, are reportedly reduced by statins. However, several studies have demonstrated that CRP is a bystander during atherogenesis. While S100A12 has been focused on as an inflammatory molecule, it remains unclear whether statins affect circulating S100A12 levels. Here, we investigated whether atorvastatin treatment affected S100A12 and which biomarkers were correlated with changes in arterial inflammation. Methods: We performed a prospective, randomized open-labeled trial on whether atorvastatin affected arterial (carotid and thoracic aorta) inflammation using18fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG-PET/CT) and inflammatory markers. Thirty-one statin-naïve patients with carotid atherosclerotic plaques were randomized to either a group receiving dietary management (n=15) or one receiving atorvastatin (10mg/day,n=16) for 12weeks.18F-FDG-PET/CT and flow-mediated vasodilation (FMD) were performed, the latter to evaluate endothelial function. Results: Atorvastatin, but not the diet-only treatment, significantly reduced LDL-cholesterol (LDL-C, -43%), serum CRP (-37%) and S100A12 levels (-28%) and improved FMD (+38%).18F-FDG-PET/CT demonstrated that atorvastatin, but not the diet-only treatment, significantly reduced accumulation of18F-FDG in the carotid artery and thoracic aorta. A multivariate analysis revealed that reduction in CRP, S100A12, LDL-C, oxidized-LDL, and increase in FMD were significantly associated with reduced arterial inflammation in the thoracic aorta, but not in the carotid artery. Conclusions: Atorvastatin treatment reduced S100A12/CRP levels, and the changes in these circulating markers mirrored the improvement in arterial inflammation. Our observations suggest that S100A12 may be an emerging therapeutic target for atherosclerosis. 相似文献
64.
Kanto S Sugawara J Masuda H Sasano H Arai Y Kyono K 《Fertility and sterility》2008,90(5):2010.e5-2010.e7
65.
Hiroyuki Ito Takafumi Tanei Kyoko Sugawara Yu Sando Naohiro Hori 《Fukushima journal of medical science》2022,68(1):37
Systemic sclerosis is a complex disease characterized by extensive fibrosis, microvascular alterations, and additional sequelae. Microvascular alterations can cause painful ulcers and necrosis; however, conservative or surgical treatment is often challenging in terms of healing. The study aimed to describe a toe ulcer with systemic sclerosis and its’ successful treatment with spinal cord stimulation. An 83-year-old woman, who was diagnosed with systemic sclerosis over the past decade, was distressed by a non-healing toe ulcer for an extended period of time. The patient underwent spinal cord stimulation treatment with the expectation of pain relief and an improvement in microcirculatory insufficiency. Her pain scales and microcirculation improved, and the toe ulcer healed. Furthermore, the frequency of Raynaud’s symptoms was reduced, and the patient’s pain decreased. There was no recurrence of the ulcer and she no longer needed a cane for walking. 相似文献
66.
Akira Kunimatsu Koichiro Yasaka Hiroyuki Akai Haruto Sugawara Natsuko Kunimatsu Osamu Abe 《Magnetic resonance in medical sciences》2022,21(1):95
Texture analysis, as well as its broader category radiomics, describes a variety of techniques for image analysis that quantify the variation in surface intensity or patterns, including some that are imperceptible to the human visual system. Cerebral gliomas have been most rigorously studied in brain tumors using MR-based texture analysis (MRTA) to determine the correlation of various clinical measures with MRTA features. Promising results in cerebral gliomas have been shown in the previous MRTA studies in terms of the correlation with the World Health Organization grades, risk stratification in gliomas, and the differentiation of gliomas from other brain tumors. Multiple MRTA studies in gliomas have repeatedly shown high performance of entropy, a measure of the randomness in image intensity values, of either histogram- or gray-level co-occurrence matrix parameters. Similarly, researchers have applied MRTA to other brain tumors, including meningiomas and pediatric posterior fossa tumors.However, the value of MRTA in the clinical use remains undetermined, probably because previous studies have shown only limited reproducibility of the result in the real world. The low-to-modest generalizability may be attributed to variations in MRTA methods, sampling bias that originates from single-institution studies, and overfitting problems to a limited number of samples.To enhance the reliability and reproducibility of MRTA studies, researchers have realized the importance of standardizing methods in the field of radiomics. Another advancement is the recent development of a comprehensive assessment system to ensure the quality of a radiomics study. These two-way approaches will secure the validity of upcoming MRTA studies. The clinical use of texture analysis in brain MRI will be accelerated by these continuous efforts. 相似文献
67.
Trends in dietary fiber intake in Japan over the last century 总被引:5,自引:0,他引:5
Nakaji S Sugawara K Saito D Yoshioka Y MacAuley D Bradley T Kernohan G Baxter D 《European journal of nutrition》2002,41(5):222-227
Summary. Background: Insufficient intake of dietary fiber (DF) is currently a major problem in the overall promotion of health in the general
population in Japan. Aim of the study: To analyze the time trends in DF intake, including DF density (total DF intake/1,000 kcal), and the ratio of water-insoluble
fiber to water-soluble fiber (IS ratio) in Japan. Methods: The time trend in DF intake in Japan was calculated from data compiled in the Japanese National Nutrition Survey. Results: The mean daily DF intake (total DF intake) in 1952 was 20.5 g/day, which rapidly declined to about 70 % of the 1952 level
in 1970, after which there was little change to 1998. DF density in 1952 was 9.7 g/1000 kcal, which declined by about 30 %
in 1970, and remained at about the same level to 1998. The IS ratio has remained stable over this period. Whereas total DF
intake and DF density in Japan are similar to those in Western countries, the IS ratios are higher in Japan. Therefore, the
higher incidence of, and mortality from, colon diverticulosis, coronary heart disease, hyperlipidemia, etc., which are all
thought to be related to fiber deficiency, in Western countries compared to Japan might be due to the differences in the IS
ratio. Conclusions: A decline in total DF intake and DF density is predicted for Japan in the future, because these parameters were lower among
the younger generation. This may be due to the marked changes in the dietary habits of the younger generation, and is a problematic
trend for Japanese health.
Received: 26 April 2002, Accepted: 22 August 2002
Correspondence to: Shigeyuki Nakaji, MD, PhD 相似文献
68.
Distinct Recurrence Pattern and Outcome of Adenocarcinoma of the Gastric Cardia in Comparison with Carcinoma of Other Regions of the Stomach 总被引:4,自引:0,他引:4
Saito H Fukumoto Y Osaki T Fukuda K Tatebe S Tsujitani S Ikeguchi M 《World journal of surgery》2006,30(10):1864-1869
Background Carcinoma arising in the cardioesophageal junction is a distinct clinical entity compared with tumors located in other regions
of the stomach. The prognosis for adenocarcinoma of the upper stomach is considered to be relatively poorer than carcinomas
of the more distal stomach. We have therefore investigated patients with carcinoma of the gastric cardia in order to evaluate
the underlying cause of this poor prognosis.
Materials and Methods Clinicopathologic features and postoperative prognosis of 101 patients with carcinoma of the cardia were evaluated and compared
with findings on 1884 patients with tumors in other regions of the stomach.
Results Tumors of the cardia had a mean size of 6.8 cm, which was significantly larger than the mean size of 5.9 cm for tumors found
in the middle- and lower third of the stomach. The incidence of serosal invasion, lymph node metastasis, and lymphatic and
blood vessel invasion was higher in association with adenocarcinoma of the cardia than with adenocarcinoma in remaining parts
of the stomach. In the analysis of patients who had undergone curative resection, the 5-year survival rates were 61.6, 79.1,
and 82.6% in patients with carcinoma of the cardia, upper one-third, and remaining middle- and lower one-third of the stomach,
respectively, and the differences were statistically significant. Multivariate analysis indicated that adenocarcinoma of the
gastric cardia is an independent prognostic factor. With regard to the site of recurrence, both lymph node and hematogenous
recurrence were observed more frequently in the cardia than in the remaining parts of the stomach.
Conclusions Our data indicate that the prognosis of patients with adenocarcinoma of the gastric cardia is extremely poor. To improve their
prognosis, new treatments in addition to gastrectomy with extensive lymph node dissection are needed. 相似文献
69.
Takagawa R Fujii S Ohta M Nagano Y Kunisaki C Yamagishi S Osada S Ichikawa Y Shimada H 《Annals of surgical oncology》2008,15(12):3433-3439
Background We evaluated the prognostic value of the preoperative serum carcinoembryonic antigen (CEA) level in patients with colorectal
cancer (CRC).
Patients and Methods The study group comprised 638 patients. The optimal cutoff value for the preoperative serum CEA level was determined. Predictive
factors of recurrence were evaluated using multivariate analyses. The relapse-free time was investigated according to the
CEA level.
Results All patients underwent potentially curative resection for CRC without distant metastasis, classified as stage I, II, or III.
The optimal cutoff value for preoperative serum CEA level was 10 ng/ml. Elevated preoperative serum CEA level was observed
in 92 patients. Multivariate analysis identified tumor–node–metastasis (TNM) stage and preoperative serum CEA level as independent
predictive factors of recurrence. The relapse-free survival between CEA levels >10 ng/ml and <10 ng/ml significantly differed
in patients with stage II and III. However, there was no significant difference in relapse-free survival between CEA levels
>10 ng/ml and <10 ng/ml in patients with stage I.
Conclusion Preoperative serum CEA is a reliable predictive factor of recurrence after curative surgery in CRC patients and a useful indicator
of the optimal treatment after resection, particularly for cases classified as stage II or stage III. 相似文献
70.
Yoh Sugawara Yusuke Mizuno Shinya Oku Takahisa Goto 《British journal of anaesthesia》2019,122(4):437-447