全文获取类型
收费全文 | 711篇 |
免费 | 103篇 |
国内免费 | 6篇 |
出版年
2023年 | 16篇 |
2022年 | 11篇 |
2021年 | 31篇 |
2020年 | 35篇 |
2019年 | 50篇 |
2018年 | 32篇 |
2017年 | 54篇 |
2016年 | 31篇 |
2015年 | 27篇 |
2014年 | 53篇 |
2013年 | 62篇 |
2012年 | 23篇 |
2011年 | 34篇 |
2010年 | 20篇 |
2009年 | 21篇 |
2008年 | 28篇 |
2007年 | 33篇 |
2006年 | 27篇 |
2005年 | 23篇 |
2004年 | 26篇 |
2003年 | 13篇 |
2002年 | 5篇 |
2001年 | 3篇 |
2000年 | 4篇 |
1999年 | 3篇 |
1998年 | 12篇 |
1997年 | 5篇 |
1995年 | 5篇 |
1994年 | 7篇 |
1993年 | 5篇 |
1992年 | 4篇 |
1991年 | 9篇 |
1990年 | 8篇 |
1989年 | 7篇 |
1988年 | 12篇 |
1987年 | 4篇 |
1986年 | 4篇 |
1985年 | 6篇 |
1984年 | 6篇 |
1983年 | 6篇 |
1982年 | 8篇 |
1981年 | 13篇 |
1980年 | 5篇 |
1979年 | 3篇 |
1978年 | 4篇 |
1976年 | 3篇 |
1973年 | 2篇 |
1972年 | 5篇 |
1971年 | 3篇 |
1970年 | 2篇 |
排序方式: 共有820条查询结果,搜索用时 269 毫秒
51.
Background
The anterior cruciate ligament rupture is a common injury which mainly affects young and active population. Faced to this problem, the development of synthetic structures for ligament reconstruction is increasing. The most recent researches focused on the development of biodegradable structures that could be functionalized to enhance host integration. This work describes the elaboration of different poly(ε-caprolactone) prototypes for the rat anterior cruciate ligament replacement in order to found the best design for further in vivo assays.Methods
According to the literature, it was decided to elaborate two different poly(ε-caprolactone) prototypes: a braided one and a free-fibers one. A chemical grafting of a bioactive polymer–poly(sodium styrene sulfonate) – was performed on both prototypes and mechanical and biological testing were assessed. Based on these results, one rat was implanted with the best prototype.Results
The mechanical and biological results demonstrated that the best prototype to implant was the poly(sodium styrene sulfonate)-grafted braided prototype. After one-month implantation, no inflammation was observable around the scar. The rat demonstrated good flexion and extension of the lower limb without any anterior drawer. The prototype was highly anchored to the bone. ESEM images of the explanted prototype showed the presence of cells and tissue ingrowth along and around the fibers.Conclusion
This work demonstrates the feasibility to implant a bioactive and biodegradable synthetic ligament in the rat model without any inflammation and with a good tissue anchoring at a short-term time. This will lead to an extensive in vivo assay. 相似文献52.
Low amplitude mechanical noise vibration has been shown to improve somatosensory acuity in various clinical groups with comparable deficiencies through a phenomenon known as Stochastic Resonance (SR). This technology showed promising outcomes in improving somatosensory acuity in other clinical patients (e.g., Parkinson’s disease and osteoarthritis). Some degree of chronic somatosensory deficiency in the knee has been reported following anterior cruciate ligament (ACL) reconstruction surgery. In this study, the effect of the SR phenomenon on improving knee somatosensory acuity (proprioception and kinesthesia) in female ACL reconstructed (ACLR) participants (n = 19) was tested at three months post-surgery, and the results were compared to healthy controls (n = 28). Proprioception was quantified by the measure of joint position sense (JPS) and kinesthesia with the threshold to detection of passive movement (TDPM).The results based on the statistical analysis demonstrated an overall difference between the somatosensory acuity in the ACLR limb compared to healthy controls (p = 0.007). A larger TDPM was observed in the ACLR limb compared to the healthy controls (p = 0.002). However, the JPS between the ACLR and healthy limbs were not statistically significantly different (p = 0.365). SR significantly improved JPS (p = 0.006) while the effect was more pronounced in the ACLR cohort. The effect on the TDPM did not reach statistical significance (p = 0.681) in either group.In conclusion, deficient kinesthesia in the ACLR limb was observed at three months post-surgery. Also, the positive effects of SR on somatosensory acuity in the ACL reconstructed group warrant further investigation into the use of this phenomenon to improve proprioception in ACLR and healthy groups. 相似文献
53.
Partial anterior cruciate ligament (p-ACL) rupture is a common injury, but the impact of a p-ACL injury on in vivo joint kinematics has yet to be determined in an animal model. The in vivo kinematics of the ovine stifle joint were assessed during ‘normal’ gait, and at 20 and 40 weeks after p-ACL transection (Tx). Gross morphological scoring of the knee was conducted. p-ACL Tx creates significant progressive post-traumatic osteoarthritis (PTOA)-like damage by 40 weeks. Statistically significant increases for flexion angles at hoof-strike (HS) and mid-stance (MST) were seen at 20 weeks post p-ACL Tx and the HS and hoof-off (HO) points at 40 weeks post p-ACL-Tx, therefore increased flexion angles occurred during stance phase. Statistically significant increases in posterior tibial shift at the mid-flexion (MF) and mid-extension (ME) points were seen during the swing phase of the gait cycle at 40 weeks post p-ACL Tx. Correlation analysis showed a strong and significant correlation between kinematic changes (instabilities) and gross morphological score in the inferior-superior direction at 40 weeks post p-ACL Tx at MST, HO, and MF. Further, there was a significant correlation between change in gross morphological combined score (ΔGCS) and the change in location of the helical axis in the anterior direction (ΔsAP) after p-ACL Tx for all points analyzed through the gait cycle. This study quantified in vivo joint kinematics before and after p-ACL Tx knee injury during gait, and demonstrated that a p-ACL knee injury leads to both PTOA-like damage and kinematic changes. 相似文献
54.
In our previous studies, programmed cell death (PCD) was induced in human periodontal ligament (PDL) cells, through activation of caspase-3 and upregulation of CASP5 gene (encoding caspase-5 protein), in response to mechanical stretch loading. The aim of this study is to explore the relationship between the inflammatory caspase, caspase-5, and the apoptotic executioner protein, caspase-3, in human PDL cells. Here, we found that cyclic stretching upregulated the activity and the protein expression level of caspase-3 and -5 and the addition of the caspase-3 inhibitor or caspase-5 inhibitor significantly inhibited the stretch-induced PCD. Meanwhile, the inhibition of caspase-5 inhibited the activation of caspase-3 and vice versa. The result of coimmunoprecipitation also demonstrated that the expression of caspase-3 was immunoprecipitated with caspase-5. Thus, our study revealed that the in vitro application of cyclic stretching induced PCD by activation of caspase-3 and -5 in human PDL cells, and these two caspases could interact with each other after mechanical stretch loading. The study may facilitate further studies on the mechanism of stretch-induced PCD and help us understand the force-related periodontal homeostasis and remodeling better. 相似文献
55.
56.
Ya Zheng Chen Dong Junling Yang Yi Jin Wenjie Zheng Qiao Zhou Yi Liang Liuliu Bao Guijuan Feng Juan Ji Xingmei Feng Zhifeng Gu 《Journal of cellular physiology》2019,234(11):20662-20674
The mechanism of local inflammation and systemic injury in chronic periodontitis is complicated, in which and exosomes play an important role. In our study, we found that T helper cell 17 (Th17)/regulatory T cell (Treg) balance is destabilized in the peripheral blood of patients with periodontitis, with upregulated Th17 or downregulated Treg, respectively. Porphyromonas gingivalis lipopolysaccharide (LPS) was used to simulate the inflammatory microenvironment of chronic periodontitis. The exosomes were extracted from periodontal ligament stem cells (PDLSCs) in LPS-induced periodontitis environment, which inversely effected on CD4+ T cells under normal and inflammatory conditions. Furthermore, compared with exosomes from normal PDLSCs, lower expression of microRNA-155-5p (miR-155-5p) and higher expression of Sirtuin-1 (SIRT1) were observed in exosomes from LPS-stimulated PDLSCs. Exosomes from PDLSCs alleviated inflammatory microenvironment through Th17/Treg/miR-155-5p/SIRT1 regulatory network. This study aimed to find the “switching” factors that affected the further deterioration of periodontitis to maximally control the multiple downstream damage signal factors to further understand periodontitis and find new targets for its treatment. 相似文献
57.
Xu WP Shiba H Mizuno N Uchida Y Mouri Y Kawaguchi H Kurihara H 《Cell biology international》2004,28(10):675-682
Bone morphogenetic proteins (BMPs) have multiple functions in the development and growth of skeletal and extraskeletal tissues. Therefore, BMPs may regulate the regeneration of periodontal tissue. To investigate this issue, we examined the effects of BMP-4, -5 and -6 on DNA synthesis and the expression of bone-related proteins in cultures of human periodontal ligament (HPL) cells. The expression of bone-related proteins was determined by Real-time polymerase chain reaction and enzyme linked immunosorbent assay in cultures of HPL cells. DNA synthesis was estimated by measuring bromoderoxyuridine incorporation. It was found that BMP-4, -5 and -6 enhanced DNA synthesis dose-dependently. BMP-4 and -5 increased the levels of osteopontin, BMP-2, alkaline phosphatase and core binding factor alpha 1 mRNAs. BMP-6 stimulated the expression of osteopontin, BMP-2, ALPase and osteoprotegerin. These findings show that BMP-4, -5 and -6 have different actions on the expression of bone-related proteins and may play a role in the regeneration of periodontal tissue by promoting cell proliferation and protein expression. 相似文献
58.
59.
60.
Tateyama Y Takano Y Tohno Y Moriwake Y Tohno S Hashimoto M Araki T 《Biological trace element research》2000,74(3):211-221
To show the relationships of calcium accumulation in the thoracic aorta to the other tissues, calcium contents were determined
with a microwave-induced plasma-atomic emission spectrometer on arteries, veins, cartilages, ligaments, and bones. These tissues
were resected from 18 individuals, consisting of 11 men and 7 women who died in the age range 59–91 yr. As thoracic and abdominal
aortas are routinely used for radiographic examination of arterial calcification, they appear to be standard tissues of the
calcium accumulation. The calcium accumulations were determined in the femoral artery, the superior and inferior venae cavae,
the internal jugular vein, cartilages of the articular disk of the temporomandibular joint and the intervertebral disk, both
the ligaments of the anterior cruciate ligament and the ligamentum capitis femoris, and the calcaneus, in contrast with the
thoracic aorta.
As calcium increased in the thoracic aorta, it increased in the femoral artery, the articular disk of the temporomandibular
joint, the intervertebral disk, both ligaments of the anterior cruciate ligament, and the ligamentum capitis femoris, but
it did not increase in veins, such as the superior and inferior venae cavae and the internal jugular vein. In contrast, it
decreased in the calcaneus. 相似文献