首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   2541篇
  免费   66篇
  国内免费   48篇
耳鼻咽喉   15篇
儿科学   14篇
妇产科学   12篇
基础医学   1362篇
口腔科学   73篇
临床医学   121篇
内科学   175篇
皮肤病学   17篇
神经病学   63篇
特种医学   82篇
外科学   185篇
综合类   177篇
一般理论   1篇
预防医学   192篇
眼科学   14篇
药学   104篇
  1篇
中国医学   17篇
肿瘤学   30篇
  2024年   4篇
  2023年   16篇
  2022年   42篇
  2021年   37篇
  2020年   33篇
  2019年   185篇
  2018年   170篇
  2017年   90篇
  2016年   722篇
  2015年   311篇
  2014年   67篇
  2013年   99篇
  2012年   72篇
  2011年   102篇
  2010年   63篇
  2009年   80篇
  2008年   67篇
  2007年   38篇
  2006年   71篇
  2005年   39篇
  2004年   31篇
  2003年   41篇
  2002年   27篇
  2001年   17篇
  2000年   18篇
  1999年   16篇
  1998年   5篇
  1997年   7篇
  1996年   8篇
  1995年   13篇
  1994年   7篇
  1993年   6篇
  1992年   2篇
  1991年   5篇
  1988年   2篇
  1987年   3篇
  1985年   13篇
  1984年   15篇
  1983年   7篇
  1982年   13篇
  1981年   10篇
  1980年   14篇
  1979年   9篇
  1978年   12篇
  1977年   11篇
  1976年   11篇
  1975年   8篇
  1974年   6篇
  1973年   6篇
  1965年   1篇
排序方式: 共有2655条查询结果,搜索用时 31 毫秒
991.
BACKGROUND: The chemical compositions and structure of calcium phosphate bone cement are similar to those of human bone, which can fill the bone collapse caused by fracture and induce osteogenesis, but its degradation rate is slow. OBJECTIVE: To evaluate the biocompatibility of the calcium phosphate cement/fibrin glue and the feasibility of repairing radius defects. METHODS: In vitro cytotoxicity experiment: Mouse fibroblasts were cultured in the calcium phosphate bone cement/fibrin glue extracts, phenol solution, and RPMI 1640 culture medium containing 10% fetal bovine serum, respectively, to detect the cytotoxicity grade. Hemocompatibility experiment: Calcium phosphate bone cement/fibrin glue extracts, normal saline and distilled water were respectively added into the rabbit anticoagulation, to detect the hemolytic rate. Forty-five New Zealand white rabbits were enrolled and modeled into bilateral radius defects, followed by randomly allotted into three groups: blank control group without any intervention, experimental and control groups were given the implantation with calcium phosphate bone cement/fibrin glue and autologous radius, respectively. X-ray, histology, bone mineral density and biomechanical test were performed at postoperative 4, 8 and 16 weeks. RESULTS AND CONCLUSION: The toxicity grade of the calcium phosphate cement/fibrin glue was 0 to 1. The hemolytic rate of the calcium phosphate cement/fibrin glue was 3.15%. At 16 weeks postoperatively, X-ray showed that in the experimental and control groups, the fracture line disappeared completely, pulp cavity was recanalized, and in plastic completely. Histology showed that the reconstructed bone trabecular was obvious, plate layer of bone was mature, and medullary cavity recanalization appeared in the control group; there were a large number of new grid-shaped woven bone tissues growing into the material in the experimental group, with overt degradation, and degradation rate was in parallel to bone ingrowth. The bone density, the maximum load, maximum stress and failure energy in the experimental and control groups were significantly higher than those in the blank control group (P < 0.05), and all above indicators showed no significant differences between the experimental and control groups. These results manifest that the calcium phosphate bone cement/fiber protein glue composite material holding a good biocompatibility can promote bone tissue regeneration for bone defect repair, achieving similar curative effect with autologous bone transplantation.  相似文献   
992.
BACKGROUND: With the promotion of 3D printing technology, 3D printing scaffolds for bone tissue engineering have become the new ideas for jaw bone repair. OBJECTIVE: To compare the physical and biological properties of sheep vertebral bone meal/polyvinyl alcohol (PVA) scaffold, nano-hydroxyapatite (nHA)/PVA scaffold, and sheep vertebral bone meal/PVA nonporous bone plate. METHODS: 3D printing technology was used to print sheep vertebral bone meal/PVA scaffold, nHA/PVA scaffold, and sheep vertebral bone meal/PVA nonporous bone plate. Porosity, morphology, water absorption rate and mechanical properties of different scaffolds were detected. Three kinds of scaffolds were all used to culture bone marrow mesenchymal stem cells, and cell proliferation ability was detected using cell counting kit-8 at 1, 4, 7 days of culture. RESULTS AND CONCLUSION: Under scanning electron microscope, the sheep vertebral bone meal/PVA scaffold and nHA/PVA scaffold exhibited regular and interconnected pores with good continuity and clear network structure; the sheep vertebral bone meal/PVA nonporous bone plate had no obvious pores; however, it had dense and evenly distributed micropores with different sizes on its surface. The porosity of nHA/PVA scaffold was lower than that of the sheep vertebral bone meal/PVA scaffold (P < 0.05). The water absorption rate was highest for the nHA/PVA scaffold followed by the sheep vertebral bone meal/PVA scaffold and the sheep vertebral bone meal/PVA nonporous bone plate (P < 0.05). In contrast, the scaffold toughness was highest for the sheep vertebral bone meal/PVA nonporous bone plate, followed by the sheep vertebral bone meal/PVA scaffold and nHA/PVA scaffold. In addition, the cell proliferation activity of cells cultured on the sheep vertebral bone meal/PVA scaffold was significantly higher than that cultured on the other two kinds of scaffolds. Taken together, the 3D printing sheep vertebral bone/PVA scaffold has good physical and chemical performance.  相似文献   
993.
BACKGROUND: Articular cartilage repair has been a difficulty in the clinical setting, which is mainly treated with autologous or allogeneic osteochondral grafts, and cartilage periosteum or periosteum grafts. However, the limited source, secondary lesion and immunological rejection force some researchers to search for a novel treatment strategy, cartilage tissue engineering, that is of great significance for cartilage regeneration and repair. OBJECTIVE: To investigate the tissue-engineered scaffolds for the repair of articular cartilage defects. METHODS: The first author searched the PubMed and WanFang databases for the articles addressing tissue-engineered cartilage for articular cartilage defects published between 1991 and 2015 using the keywords “articular cartilage defect, scaffold, tissue engineered cartilage” in English and Chinese, respectively. The irrelative and repetitive literatures were excluded. RESULTS AND CONCLUSION: Finally 48 eligible literatures were enrolled based on the inclusion and exclusion criteria. Cartilage tissue engineering possesses the advantages of controllability, little damage to tissue itself, and biological repair of injured cartilage. Tissue-engineered scaffold material is a critical factor in tissue engineering construction; therefore, it should hold biodegradability and histocompatibility. The commonly used scaffold materials include natural macromolecule materials (collagen, silk fibroin and chitosan), and synthetic polymer materials (polylactic acid and tricalcium phosphate). It is necessary to prepare composite scaffolds with high bioactivity integrate advantages of each material. The tissue engineering is bound to be a hotspot in the field of articular cartilage repair.   相似文献   
994.
BACKGROUND: Common peroneal nerve injury is one of the rare but serious complications after total knee arthroplasty. With the increased amount of operations, peroneal nerve injury would become more and more common, although the incidence rate is relatively low.  相似文献   
995.
BACKGROUND:With the development of tissue engineering technology and the deep research of tendon regeneration, many problems caused by traditional tendon transplantation will be solved. OBJECTIVE:To evaluate and prospect the effects of corresponding mechanical systems on seeding cells based on the characters of tendon, stem cells as well as mechanical systems. METHODS:CBM, CNKI, CqVip and PubMed databases were retrieved for reviews and articles related to tissue-engineered tendon published from January in 2005 to December in 2015. The keywords were “tissue engineering, tendon, tendon stem cell, mechanical stimulation and seeding cells” in Chinese and English, respectively. Finally a total of 63 articles were selected for overview. RESULTS AND CONCLUSION:As all kinds of stem cells and the corresponding mechanical systems exhibit advantages and disadvantages when applied for tissue engineering, it is advisable to make appropriate choices according to the research needs. Tendon stem cells show a broad application prospect in tendon regeneration, which will grow into required tendon tissues through appropriate, accurate and gentle mechanical stimulations, thereby providing another alternative to improve the tendon healing.  相似文献   
996.
BACKGROUND:Dental pulp stem cells are characterized by multi-lineage differentiation and proliferation abilities and are easy to obtain, so they are becoming an issue of concern in regenerative medicine. OBJECTIVE:To provide clues and direction for further study by analyzing progress of domestic and overseas research on dental pulp stem cells, and summarizing their application in regenerative medicine. METHODS:The “dental pulp stem cell, regenerative medicine, tissue engineering” in Chinese and English served as the search terms to search articles related to dental pulp stem cells and regenerative medicine, published from 2000 to 2015 in Medline, PubMed, CNKI, Wanfang and Cqvip databases. Totally 46 articles were selected for overview.  RESULTS AND CONCLUSION:Dental pulp stem cells, which hold the capacity of self-renewal and multi-lineage differentiation, are relatively easy to obtain, and exhibit a great potential in regenerative medicine. The research of dental pulp stem cells in repairing bone defects has entered the clinical trial phase, but the research of cell differentiation into other tissues is still in basic trial phase and needs further development.  相似文献   
997.
BACKGROUND: The effects of advanced glycation end products (AGEs) on osteoclast-induced bone resorption is controversial and the underlying mechanisms remain unclear. Most of the studies indicate that AGEs can enhance bone resorption, while some others show the opposite effects. OBJECTIVE:To investigate the effects of AGEs on osteoclast-induced inorganic matrix dissolution and organic component degradation and the underlying mechanisms. METHODS: RAW 264.7 cells were induced to generate osteoclasts, and AGEs (50-400 µg/mL) or control-bovine serum albumin (100 µg/mL) was added since the beginning of the induction. The effect of AGEs on bone resorption was evaluated by analyzing the area of resorption pits on the Osteo Assay Surface plates and the expression of cathepsin K. Furthermore, the number of tartrate-resistant acid phosphatase (TRAP)-positive multinucleated cells, nuclei per osteoclasts and the expression of integrin ανβ3 were detected. RESULTS AND CONCLUSION: The area of resorption pits and expression of cathepsin K in AGEs groups were significantly decreased compared with the control group, and this inhibiting effect became more obvious with the increase of AGEs concentration. TRAP staining also showed that number of TRAP-positive multinucleated cells and nuclei per osteoclast were significantly reduced in an AGE dose-dependent manner. Quantitative PCR revealed that the expression of integrin ανβ3 decreased significantly with the extension of AGEs incubation time. These data indicate that AGEs can exert inhibitory effects on organic and inorganic matrix degradation induced by osteoclasts. The underlying mechanism may be involved in the inhibitory effects of AGEs on directed differentiation and cell fusion of osteoclast precursor cells, and migration and adhension of osteoclasts. 中国组织工程研究杂志出版内容重点:组织构建;骨细胞;软骨细胞;细胞培养;成纤维细胞;血管内皮细胞;骨质疏松;组织工程  相似文献   
998.
BACKGROUND: Ligustrazine has been shown to restore the function of the femoral head via the revascularization, increased blood flow, the absorption of necrotic bone, and bone regeneration. OBJECTIVE:To study the effects of ligustrazine on remodeling of periodontal tissues and the expression of osteoprotegerin in the maintenance phase in rats with orthodontic tooth movement. METHODS: Thirty-two healthy male Wistar rats were included and equally randomized into four groups. Maxillary left first molar mesialization was performed through traction of 50 g force for 21 days to establish the rat model of tooth movement. 5, 10, 15 mg/L ligustrazine (50 µL) were locally injected into the first molar periosteum in model rats on the day before removing the orthodontic forcing device. Same volume of saline was injected in the control group. The injection was administered every other day. At 1 and 4 weeks after injection, the distance of tooth movement, the recurrence distances and percentage were determined and calculated. The pathological changes in periodontal tissues were observed by immunohistochemistry and hematoxylin-eosin staining. The width of the parodontium and number of osteoblasts were observed under an optical microscope. RESULTS AND CONCLUSION: The recurrence distance in the control group was increased compared with the experimental group, while the number of osteoblasts and osteoprotegerin immunoreactivity were decreased. Good width of the parodontium and small recurrence trend were found in 10 mg/L ligustrazine group. These findings indicate that ligustrazine promotes the proliferation of osteoblasts and enhances the expression of osteoprotegerin, which is beneficial to the retention of teeth after orthodontic surgery. 中国组织工程研究杂志出版内容重点:组织构建;骨细胞;软骨细胞;细胞培养;成纤维细胞;血管内皮细胞;骨质疏松;组织工程  相似文献   
999.
BACKGROUND: Cilium is an antenna-like organelle that plays a vital role in all organs generation and maintenance. Ciliopathies refer to multisystem diseases caused by disorders of the cilia structure and function. OBJECTIVE: To introduce current understanding of the structure and function of the cilium, with a focus on the study progress of ciliopathies. METHODS: PubMed database was searched by computer using the keywords of “primary cilium, motion cilium, ciliopathy”. Totally 371 relevant articles published from 1959 to 2015 were retrieved. After excluding repetitive and irrelevant articles, we enrolled 32 English literatures regarding cilia structure, function and ciliopathies in accordance with the inclusion criteria. RESULTS AND CONCLUSION: Ciliopathies almost involve every system of the human body, such as the brain, eyes, liver, kidney, bone and reproductive system. Most ciliopathies are related to human developmental or degenerative diseases, which characterized by wide-ranging clinical and genetic heterogeneity, such as primary ciliary dyskinesia, ploycystic kidney disease, infertility, blindness and tumor. In view of the medical importance of the cilium, scholars have devoted to studying the underlying cellular mechanisms. These in turn have revealed that ciliopathies are not only caused by defective assembly of the cilium, but also by impaired ciliary signaling. 中国组织工程研究杂志出版内容重点:组织构建;骨细胞;软骨细胞;细胞培养;成纤维细胞;血管内皮细胞;骨质疏松;组织工程  相似文献   
1000.
BACKGROUND: O-arm navigation integrates CT image quality and the flexible mobility of the C-arm. Surgery for severe spinal deformity is very difficult, with high incidence of nerve injury, so it is a challenging surgery for spinal surgery. The role of O-arm in the correction of spinal deformity is particularly important.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号