全文获取类型
收费全文 | 570篇 |
免费 | 51篇 |
国内免费 | 1篇 |
专业分类
耳鼻咽喉 | 5篇 |
儿科学 | 21篇 |
妇产科学 | 4篇 |
基础医学 | 116篇 |
口腔科学 | 17篇 |
临床医学 | 43篇 |
内科学 | 119篇 |
皮肤病学 | 24篇 |
神经病学 | 53篇 |
特种医学 | 16篇 |
外科学 | 105篇 |
综合类 | 2篇 |
预防医学 | 20篇 |
药学 | 28篇 |
肿瘤学 | 49篇 |
出版年
2023年 | 3篇 |
2022年 | 7篇 |
2021年 | 15篇 |
2020年 | 8篇 |
2019年 | 19篇 |
2018年 | 14篇 |
2017年 | 22篇 |
2016年 | 8篇 |
2015年 | 12篇 |
2014年 | 17篇 |
2013年 | 25篇 |
2012年 | 28篇 |
2011年 | 31篇 |
2010年 | 32篇 |
2009年 | 21篇 |
2008年 | 30篇 |
2007年 | 40篇 |
2006年 | 38篇 |
2005年 | 35篇 |
2004年 | 30篇 |
2003年 | 17篇 |
2002年 | 25篇 |
2001年 | 8篇 |
2000年 | 7篇 |
1999年 | 16篇 |
1998年 | 6篇 |
1997年 | 6篇 |
1996年 | 6篇 |
1995年 | 11篇 |
1994年 | 2篇 |
1993年 | 6篇 |
1992年 | 3篇 |
1991年 | 8篇 |
1990年 | 4篇 |
1989年 | 3篇 |
1988年 | 6篇 |
1987年 | 4篇 |
1986年 | 6篇 |
1985年 | 7篇 |
1983年 | 3篇 |
1979年 | 2篇 |
1978年 | 3篇 |
1977年 | 2篇 |
1976年 | 2篇 |
1975年 | 2篇 |
1974年 | 6篇 |
1973年 | 5篇 |
1972年 | 4篇 |
1968年 | 2篇 |
1966年 | 1篇 |
排序方式: 共有622条查询结果,搜索用时 31 毫秒
51.
52.
Ando T Kobayashi E Liao H Maruyama T Muragaki Y Iseki H Kubo O Sakuma I 《Brain tumor pathology》2011,28(1):43-51
Photodynamic diagnosis is used during glioma surgery. Although some studies have shown that the spectrum of fluorescence was
efficient for precise tumor diagnosis, previous methods to characterize the spectrum have been problematic, which can lead
to misdiagnosis. In this paper, we introduce a comparison technique to characterize spectrum from pathology and results of
preliminary measurement using human brain tissues. We developed a spectrum scanning system that enables spectra measurement
of raw tissues. Because tissue preparations retain the shape of the device holder, spectra can be compared precisely with
pathological examination. As a preliminary analysis, we measured 13 sample tissues from five patients with brain tumors. The
technique enabled us to measure spectra and compare them with pathological results. Some tissues exhibited a good relationship
between spectra and pathological results. Although there were some false positive and false negative cases, false positive
tissue had different spectra in which intensity of short-wavelength side was also high. The proposed technique provides an
accurate comparison of quantitative fluorescence spectra with pathological results. We found that spectrum analysis may reduce
false positive errors. These results will increase the accuracy of tumor tissue identification. 相似文献
53.
Kenji Wakai Mariko Naito Toru Naito Masaaki Kojima Haruo Nakagaki Osami Umemura Makoto Yokota Nobuhiro Hanada Takashi Kawamura 《Community dentistry and oral epidemiology》2010,38(1):43-49
Wakai K, Naito M, Naito T, Kojima M, Nakagaki H, Umemura O, Yokota M, Hanada N, Kawamura T. Tooth loss and intakes of nutrients and foods: a nationwide survey of Japanese dentists. Community Dent Oral Epidemiol 2010; 38: 43–49. © 2009 John Wiley & Sons A/S Abstract –
Objectives: To clarify the association of tooth loss with dietary intakes among dentists, for whom sufficient dental care is available.
Methods: We analyzed the data from 20 366 Japanese dentists (mean age ± SD, 52.2 ± 12.1 years; women 8.0%) who participated in a nationwide cohort study from 2001 to 2006. The baseline questionnaire included a validated food-frequency questionnaire to estimate intakes of foods and nutrients. We computed the geometric means of daily intakes by the number of teeth, adjusting for age, sex, smoking, physical activity, and history of diabetes.
Results: The mean intakes of some key nutrients and food groups, such as carotene, vitamins A and C, milk and dairy products, and vegetables including green-yellow vegetables, decreased with the increasing number of teeth lost ( P for trend <0.05). On the contrary, mean intakes of carbohydrate, rice, and confectioneries were increased among those with fewer teeth ( P for trend <0.05). The difference in the geometric mean (%) between totally edentulous subjects and those with ≥25 teeth, that is [(Geometric mean for ≥25 teeth) — (Geometric mean for 0 teeth)]/(Geometric mean for ≥25 teeth) × 100, was 14.3%, 8.6%, 6.1%, and –6.1% for carotene, vitamin C, vitamin A, and carbohydrate, respectively. For food groups, it was 26.3%, 11.9%, 5.6%, –9.5%, and –29.6% for milk and dairy products, green-yellow vegetables, total vegetables, rice, and confectioneries, respectively.
Conclusions: Tooth loss was linked with poorer nutrition even among dentists. 相似文献
Objectives: To clarify the association of tooth loss with dietary intakes among dentists, for whom sufficient dental care is available.
Methods: We analyzed the data from 20 366 Japanese dentists (mean age ± SD, 52.2 ± 12.1 years; women 8.0%) who participated in a nationwide cohort study from 2001 to 2006. The baseline questionnaire included a validated food-frequency questionnaire to estimate intakes of foods and nutrients. We computed the geometric means of daily intakes by the number of teeth, adjusting for age, sex, smoking, physical activity, and history of diabetes.
Results: The mean intakes of some key nutrients and food groups, such as carotene, vitamins A and C, milk and dairy products, and vegetables including green-yellow vegetables, decreased with the increasing number of teeth lost ( P for trend <0.05). On the contrary, mean intakes of carbohydrate, rice, and confectioneries were increased among those with fewer teeth ( P for trend <0.05). The difference in the geometric mean (%) between totally edentulous subjects and those with ≥25 teeth, that is [(Geometric mean for ≥25 teeth) — (Geometric mean for 0 teeth)]/(Geometric mean for ≥25 teeth) × 100, was 14.3%, 8.6%, 6.1%, and –6.1% for carotene, vitamin C, vitamin A, and carbohydrate, respectively. For food groups, it was 26.3%, 11.9%, 5.6%, –9.5%, and –29.6% for milk and dairy products, green-yellow vegetables, total vegetables, rice, and confectioneries, respectively.
Conclusions: Tooth loss was linked with poorer nutrition even among dentists. 相似文献
54.
Background Platelets contain many kinds of growth factors with the ability to accelerate angiogenesis. We analyzed whether a single injection of platelet-rich plasma (PRP) would accelerate surgical angiogenesis in necrotic bone implanted with vascular tissue.
Methods We used 24 Japanese White rabbits. PRP was refined from autologous blood by separation twice with centrifugation. A removed iliac bone was frozen in liquid nitrogen to ensure complete cellular necrosis. A narrow hole was made in the bone and the saphenous vascular bundle was passed through the hole. The bone was wrapped after injection of either 1 mL (1) PRP, or (2) saline solution into the hole, and was placed subcu-taneously in the thigh. In both groups, angiogenesis was compared 1 week and 2 weeks after surgery.
Result Angiogenesis was observed along the implanted vascular bundle in both groups. At 1 and 2 weeks after surgery, both the vessel density and the average length of newly formed vessels of the experimental group were significantly greater than in the control group. Both the vessel density and the length were greater after 2 weeks than after 1 week.
Interpretation A single injection of PRP accelerates surgical angiogenesis in vascular-implanted necrotic bone. 相似文献
Methods We used 24 Japanese White rabbits. PRP was refined from autologous blood by separation twice with centrifugation. A removed iliac bone was frozen in liquid nitrogen to ensure complete cellular necrosis. A narrow hole was made in the bone and the saphenous vascular bundle was passed through the hole. The bone was wrapped after injection of either 1 mL (1) PRP, or (2) saline solution into the hole, and was placed subcu-taneously in the thigh. In both groups, angiogenesis was compared 1 week and 2 weeks after surgery.
Result Angiogenesis was observed along the implanted vascular bundle in both groups. At 1 and 2 weeks after surgery, both the vessel density and the average length of newly formed vessels of the experimental group were significantly greater than in the control group. Both the vessel density and the length were greater after 2 weeks than after 1 week.
Interpretation A single injection of PRP accelerates surgical angiogenesis in vascular-implanted necrotic bone. 相似文献
55.
Chiba H Kazama T Takenouchi T Nomoto S Yamada S Tago O Ito M 《The British journal of dermatology》2000,142(6):1190-1194
We describe two Japanese female patients with pigmented extramammary Paget's disease (EMPD); one patient had a dark brown plaque and the other had a reddish patch with a pigmented area, both affecting the vulval region. Histochemical and immunohistochemical examinations confirmed EMPD with melanocyte colonization; plump tumour cells with a large nucleus and pale cytoplasm that were positive for CAM 5.2 and CEA proliferated singly or in nests in the epidermis, and scattered among the tumour cells were many dendritic cells with a large amount of melanin that were positive for HMB-45 and S-100 protein. Fontana-Masson (FM) stain showed many positive cells with well-developed dendritic processes within and around tumour nests. Histochemical and immunohistochemical studies of non-pigmented EMPD cases on the same region showed that HMB-45 positive cells were sparse or not detected at all, and that also FM staining-positive cells were decreased or not detected, and their dendritic processes were poorly formed. The present study suggests that there might be heterogeneity in EMPD in terms of relationships between Paget's cells and melanocytes. 相似文献
56.
57.
A 66-year-old man presented with complaints of numbness for the past 5 years and progressive motor weakness of the right leg for the previous 2 months. Magnetic resonance imaging revealed large intra- and extracranial tumors in the frontoparietal region. Physical examination suggested the extracranial lesion was a subcutaneous lipoma, which had been partially resected 60 years before, connected to the intracranial lesion via a defect of the skull. Gross total removal of the tumors was performed. Histological examination showed the intracranial lesion was epidermoid tumor, and connected to the extracranial lipoma by a lipoma bridge. The symptoms improved remarkably following surgery. This case of intracranial epidermoid tumor associated with intra-extracranial lipoma indicates that implantation of skin tissue in childhood carries the risk of epidermoid tumor even after several decades. Neuroimaging screening is recommended to detect the development of any intracranial components. 相似文献
58.
Kenji Takahashi Hiromasa Kurosaki Sanshiro Hashimoto Kenji Takenouchi Toshikazu Kamada Hiroshi Nakamura 《Journal of orthopaedic science》2011,16(4):376-381
Background
The clinical evidence of the efficacy of hyperthermia on osteoarthritis (OA) has not yet been clearly established. In addition, the application of a modality that can control the temperature inside the joints has not been reported. The purpose of this study was to investigate the effect of percutaneous radiofrequency hyperthermia, which could safely raise the temperature of the body core, in patients with OA knees. 相似文献59.
Osami Kawarada Yoshiaki Yokoi Nobuyuki Morioka Shinji Nakata Kazushi Takemoto 《Catheterization and cardiovascular interventions》2005,65(2):187-192
Chronic total occlusions in the superficial femoral artery (SFA) are the longest and straightest lesions in the whole body. This presents additional technical challenges and the inability to cross the occluded lesion is a common cause of procedural failure in these percutaneous interventions. The objective of this study was to investigate the usefulness of a strategy using a hydrophilic 1.5 mm J-tip 0.035' guidewire with an over-the-wire balloon catheter under ultrasound guidance for chronic total occlusions in the SFA. This strategy was performed in 32 consecutive patients (36 limbs). Average occlusion length was 17 +/- 10 cm (3-40 cm). The crossover approach was performed in 26 cases (72%); in the remaining 10 cases, the antegrade ipsilateral approach was selected. The technical success rate was 92% (32/36). A secondary popliteal artery approach was performed in the three failed limbs and was successful in two limbs, increasing the final technical success rate to 97%. This novel procedure may be considered the preferred strategy for intervening in chronic total occlusions in the SFA. 相似文献
60.
Rapid deletion of rearranged T cell antigen receptor (TCR) Vα-Jα segment by secondary rearrangement in the thymus: Role of continuous rearrangement of TCR α chain gene and positive selection in the T cell repertoire formation
下载免费PDF全文
![点击此处可从《Proceedings of the National Academy of Sciences of the United States of America》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Fanping Wang Ching-Yu Huang Osami Kanagawa 《Proceedings of the National Academy of Sciences of the United States of America》1998,95(20):11834-11839
A rearranged T cell receptor (TCR) Vα and Jα gene from a cytochrome c-specific T cell hybridoma was introduced into the genomic Jα region. The introduced TCR α chain gene is expressed in a majority of CD3 positive and CD4 CD8 double-negative immature thymocytes. However, only a few percent of the double-positive and single-positive thymocytes express this TCR α chain. This decrease is caused by a rearrangement of TCR α chain locus, which deletes the introduced TCR gene. Analysis of the mice carrying the introduced TCR α chain and the transgenic TCR β chain from the original cytochrome c-specific T cell hybridoma revealed that positive selection efficiently rescues double-positive thymocytes from the loss of the introduced TCR α chain gene. In the mice with negatively selecting conditions, T cells expressing the introduced TCR αβ chains were deleted at the double-positive stage. However, a large number of thymocytes escape negative selection by using an endogenous TCR α chain created by secondary rearrangement maintaining normal thymocyte development. These results suggest that secondary rearrangements of the TCR α chain gene play an important role in the formation of the T cell repertoire. 相似文献