全文获取类型
收费全文 | 5346篇 |
免费 | 279篇 |
国内免费 | 69篇 |
专业分类
耳鼻咽喉 | 50篇 |
儿科学 | 172篇 |
妇产科学 | 80篇 |
基础医学 | 628篇 |
口腔科学 | 188篇 |
临床医学 | 336篇 |
内科学 | 1362篇 |
皮肤病学 | 111篇 |
神经病学 | 263篇 |
特种医学 | 329篇 |
外科学 | 1131篇 |
综合类 | 13篇 |
预防医学 | 86篇 |
眼科学 | 38篇 |
药学 | 271篇 |
中国医学 | 8篇 |
肿瘤学 | 628篇 |
出版年
2023年 | 36篇 |
2022年 | 69篇 |
2021年 | 108篇 |
2020年 | 82篇 |
2019年 | 104篇 |
2018年 | 131篇 |
2017年 | 109篇 |
2016年 | 133篇 |
2015年 | 146篇 |
2014年 | 206篇 |
2013年 | 237篇 |
2012年 | 372篇 |
2011年 | 384篇 |
2010年 | 196篇 |
2009年 | 156篇 |
2008年 | 340篇 |
2007年 | 377篇 |
2006年 | 352篇 |
2005年 | 364篇 |
2004年 | 314篇 |
2003年 | 314篇 |
2002年 | 315篇 |
2001年 | 45篇 |
2000年 | 46篇 |
1999年 | 42篇 |
1998年 | 72篇 |
1997年 | 45篇 |
1996年 | 65篇 |
1995年 | 39篇 |
1994年 | 61篇 |
1993年 | 35篇 |
1992年 | 42篇 |
1991年 | 37篇 |
1990年 | 23篇 |
1989年 | 25篇 |
1988年 | 20篇 |
1987年 | 22篇 |
1986年 | 17篇 |
1985年 | 17篇 |
1984年 | 23篇 |
1983年 | 16篇 |
1982年 | 27篇 |
1981年 | 14篇 |
1980年 | 15篇 |
1979年 | 13篇 |
1978年 | 14篇 |
1977年 | 12篇 |
1975年 | 8篇 |
1974年 | 9篇 |
1972年 | 8篇 |
排序方式: 共有5694条查询结果,搜索用时 15 毫秒
81.
Ishikawa T Wanifuchi H Abe K Kato K Watanabe A Okada Y 《Neurologia medico-chirurgica》2010,50(11):1027-1030
A 51-year-old man presented with a rare case of brain metastasis of malignant pleural mesothelioma (MPM) manifesting as intratumoral hemorrhage. He had undergone several treatments such as left pneumonectomy, pleurectomy, chemotherapy with cis-diamminedichloroplatinum and gemcitabine hydrochloride, and irradiation. Five years later, computed tomography revealed right parietal metastasis with intratumoral hemorrhage and the patient was treated by surgery and irradiation. Six months after the surgery, recurrent intratumoral hemorrhage occurred and a second surgery was performed. MPM has a poor prognosis and brain metastasis is rare, but long-term survival has recently improved through the application of multi-modality approaches. Therefore, the number of opportunities for treating MPM metastasis will increase in the near future. Intratumoral hemorrhage may occur in patients with solitary brain metastasis of MPM, so surgery should be considered as a general candidate treatment for metastatic tumors. 相似文献
82.
Furihata M Sawada T Okada T Ishizuka M Horie T Takagi K Nagata H Kubota K 《World journal of surgery》2006,30(4):590-597
Background It is now generally believed that regulatory T cells (Tregs) play an important role in peripheral tolerance, and a defect
in Tregs is considered one of the most important factors in the induction of various kinds of autoimmune disease including
ulcerative colitis (UC). Here, we examined the change in frequency of Tregs phenotype in five patients with UC whose condition
had not been controllable by conventional conservative therapy and who were scheduled for total colectomy.
Aims The aim of this study was to elucidate the role of Tregs in the pathogenesis of UC in a clinical setting.
Methods Peripheral blood mononuclear cells (PBMCs) were obtained from five patients with UC, and the change in frequency of Tregs
was analyzed by flow cytometry before total colectomy and on postoperative days 1, 7, and 20. Tregs were defined as CD4+ CD25+
CD45RA+ T cells, and data (%) were expressed as frequency of Tregs/CD4+ T cells. Peripheral blood mononuclear cells (PBMCs)
from healthy blood donors (n = 5) and from patients undergoing other types of major surgery (n = 5) were used as controls.
Results Comparison with normal subjects showed that generation of Tregs was suppressed in UC patients before they underwent total
colectomy (0.95 versus 5.06; P = 0.009). The frequency of Tregs increased shortly after total colectomy. The frequency at postoperative days 1, 7, and 20
was 3.81%, 8.13%, and 3.76%, respectively. There were significant differences in the change in frequency in the period before
surgery and postoperative day 1, between postoperative days 1 and 7, and between days 7 and 20.
Conclusions Elimination of targeted antigens residing in the colorectal mucosa by total colectomy improved the suppressed distribution
of Tregs in UC patients. The present study provides the first direct clinical evidence that Tregs play a pivotal role in the
pathogenesis of UC. 相似文献
83.
Relation of inflammatory cytokines to atrial fibrillation after off-pump coronary artery bypass grafting. 总被引:5,自引:0,他引:5
Keiichi Ishida Fumio Kimura Mizuho Imamaki Atsushi Ishida Hitoshi Shimura Hiroki Kohno Manabu Sakurai Masaru Miyazaki 《European journal of cardio-thoracic surgery》2006,29(4):501-505
OBJECTIVE: It has been observed that a systemic inflammatory response after on-pump coronary artery bypass grafting (CABG) participates in the pathogenesis of postoperative atrial fibrillation (AF). In patients undergoing off-pump CABG, it is plausible that inflammation is associated with the development of postoperative AF. The present study examined relation of proinflammatory cytokines, which play an important role in the upstream of inflammatory cascade, to the development of AF after off-pump CABG. METHODS: The present study included 39 patients undergoing off-pump CABG. Tumor necrosis factor-alpha (TNF-alpha), interleukin (IL)-6, and IL-8, were measured by enzyme-linked immunosorbent assay, on anesthetic induction, after sternotomy before anastomoses, at the completion of anastomoses, 3 and 6h thereafter, and on postoperative days (POD) 1-4. C-reactive protein (CRP) was also measured by turbidimetric immunoassay, preoperatively, and on POD 1, 2, 3, 6, 9, and 13. RESULTS: Eleven patients (28%) developed postoperative AF. Patients with postoperative AF were older (70+/-6.4 years vs 60+/-8.8 years, P=0.001); however, there was no difference in other pre- and perioperative variables. TNF-alpha level did not change during the study period. However, IL-8 and CRP levels significantly increased after the surgery, although there was no significant difference between the two groups. IL-6 level also increased after the surgery with its peak at 6h after the completion of anastomoses. IL-6 levels of 3 and 6h after anastomoses were significantly higher in patients with postoperative AF (360+/-143 pg/ml vs 230+/-94 pg/ml, P=0.0047, 435+/-175 pg/ml vs 247+/-102 pg/ml, P=0.0005, respectively). Logistic regression analysis indicated that the highest quartile of IL-6 level immediately after the surgery (odds ratio 7.63; 95% CI, 1.06-54.9; P=0.04) and age (odds ratio 1.18; 95% CI, 1.01-1.39; P=0.04) independently predict postoperative AF. Furthermore, the maximum level of IL-6 immediately after the surgery significantly correlated to age and intraoperative blood loss (r=0.04, P=0.01, and r=0.47, P=0.04, respectively). CONCLUSIONS: Advanced age was a major risk factor for postoperative AF. Furthermore, inflammatory response induced by surgical trauma was also associated with the development of AF after off-pump CABG. 相似文献
84.
We examined whether regional differences in cortical bone mineral density (Ct.BMD) measured by peripheral quantitative computed tomography is related to the heterogeneity of bone tissue and whether regional Ct.BMD is a better indicator of changes in bone material properties. Bilateral tibiae were obtained from 17 female adult Cynomolgus monkeys (Macaca fascicularis; mean age 16.8 years). After determining that Ct.BMD was similar between the right and left tibiae, the left tibiae were used for bone histomorphometry and the right for a three-point bending test. The Ct.BMD in the posterior quadrant was significantly higher than that in the anterior quadrant. In the bone histomorphometric analysis, all parameters (i.e., average osteonal area, average osteonal bone area, osteon population density, percent osteonal area [%On.Ar], percent osteonal bone area [%On.B.Ar], percent osteonal area of initial remodeling [%Il.On.Ar], percent osteonal area of secondary remodeling [%Sd.On.Ar], porosity, and percent osteoid area in the posterior region) were significantly lower than those in the anterior region. The results indicated that in the same cross-section, bone tissue structure was heterogeneous. Both total- and posterior-Ct.BMD were positively correlated with breaking stress and negatively correlated with toughness, whereas anterior-Ct.BMD was positively correlated with elastic modulus. Backward stepwise multiple regression analyses indicated that posterior-Ct.BMD and total-Ct.BMD were the best variables for predicting breaking stress and toughness, respectively, when age is taken into account. The %On.Ar, %On.B.Ar, and %Il.On.Ar in the posterior region were negatively correlated with elastic modulus. The %On.Ar, %On.B.Ar, and %Sd.On.Ar in the posterior region were positively correlated with toughness. These findings indicated that regional Ct.BMD measurement is useful to assess changes in the material properties of bone associated with the degree of mineralization. In particular, anterior-, posterior-, and total-Ct.BMD can be used separately to predict changes in the material properties of the tibial diaphysis. 相似文献
85.
86.
87.
Teiichi Yamane Taro Date Yasuko Kanzaki Keiichi Inada Seiichiro Matsuo Kenri Shibayama Satoru Miyanaga Hidekazu Miyazaki Ken-ichi Sugimoto Seibu Mochizuki 《Circulation journal》2007,71(5):753-760
BACKGROUND: The limited efficacy and complications of segmental ostial pulmonary vein isolation (PVI) for treating atrial fibrillation (AF) have been discussed so, in the present study the feasibility and efficiency of performing segmental pulmonary vein (PV) antrum isolation to treat AF were assessed. METHODS AND RESULTS: A total of 187 patients with drug-refractory AF (paroxysmal 120, persistent 67) underwent segmental PVI guided by circumferential 20-electrode catheters (Lasso). Radiofrequency (RF) current was delivered either at the ostium using a regular Lasso (15-20 mm in diameter, 70 patients: Group 1) or at the antrum using a larger Lasso (25-30 mm in diameter, 117 patients: Group 2). A significantly wider region had to be ablated, with a longer RF application time, to isolate all 4 PVs in Group 2 patients than in Group 1 patients. Although the rate of recurrence of AF after the initial session was equal in both groups, a significantly greater number of patients were free from AF after a mean of 1.4 procedures in Group 2 than in Group 1 (93% vs 76% for paroxysmal AF, 78% vs 48% for persistent AF). CONCLUSIONS: Segmental antral PVI using large-sized Lasso catheters was found to be more effective and safer than ostial PVI for the treatment of AF. 相似文献
88.
89.
Nobuyasu Hirai Kei Kasahara Hiroyuki Fujikura Shingo Yoshihara Taku Ogawa Yoshihiko Ogawa Naokuni Hishiya Yuki Suzuki Ryuichi Nakano Hisakazu Yano Masahide Yoshikawa Keiichi Mikasa 《Journal of infection and chemotherapy》2018,24(7):570-572
Mycotic aneurysm is a rare but life-threatening disease that warrants an integrated therapeutic approach involving surgical intervention and prolonged antibiotic use. However, the causative organisms are often unidentified because antibiotics started empirically render blood and tissue cultures negative. Molecular diagnosis has been reported to be useful in such culture-negative cases. We report a case of a culture-negative mycotic aortic aneurysm due to Haemophilus influenzae, diagnosed by direct 16S rRNA polymerase chain reaction (PCR) and sequencing of the resected aneurysm tissue. PCR for serotype revealed type b, and PCR and sequencing of the ftsI gene revealed alterations in penicillin-binding protein 3, suggesting resistance to ampicillin. Multilocus sequence typing demonstrated that the isolate belonged to sequence type 54. 相似文献
90.
Melissa Soohoo Elani Streja Yoshitsugu Obi Connie M. Rhee Daniel L. Gillen Keiichi Sumida Danh V. Nguyen Csaba P. Kovesdy Kamyar Kalantar-Zadeh 《Mayo Clinic proceedings. Mayo Clinic》2018,93(8):1074-1085