首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
Adipose derived adult stem cells (ASCs) are multipotent cells that are able to differentiate into osteoblasts in presence of certain factors. The histological characteristics of periosteum makes it a specific tissue with a unique capacity to be engineered. Higher flexibility of the greater omentum is useful for reconstructive surgery. These criteria make it suitable for tissue engineering. The present study was designed to evaluate bone tissue engineering with periosteal free graft concurrent with ASCs and pedicle omentum in dog model. Twelve young female indigenous dogs were used in this experiment. In omental group (n = 4), end of omentum was wrapped by periosteum of the radial bone in abdomen of each dog. In omental-autogenously ASCs group (n = 4), 1 ml of ASCs was injected into the wrapped omentum with periosteum while in omental-allogenously ASCs group (n = 4), 1 ml of allogenous ASCs was injected. Lateral view radiographs were taken from the abdominal cavity postoperatively at the 2nd, 4th, 6th and 8th weeks post-surgery. Eight weeks after operation the dogs were re-anesthetized and the wrapped omenum by periosteum in all groups was found and removed for histopathological evaluation. Our results showed that omentum–periosteum, omental-periosteum-autogenous ASCs and omental-periosteum-allogenous ASCs groups demonstrated bone tissue formation in the abdominal cavity in dog model. The radiological, macroscopical and histological findings of the present study by the end of 8 weeks post-surgery indicate bone tissue engineering in all three groups in an equal level. The present study has shown that the wrapped omentum with periosteum concurrent with ASCs (autogenous or allogenous ASCs) lead to a favorable bone tissue formation. We suggested that it may be useful when pedicle graft omentum used concurrent with periosteum in the bone defect reconstruction, and this phenomenon should be studied in future.  相似文献   

2.
Bone grafting is used to enhance healing in osteotomies, arthrodesis, and multifragmentary fractures and to replace bony loss resulting from neoplasia or cysts. They are source of osteoprogenitor cells and induce bone formation and provide mechanical support for vascular and bone ingrowth. Autografts are used commonly but quantity of retrieved bone is limit. This study was designed to evaluate autograft and new xenograft (Bovine fetal growth plate) effects on bone healing process. Twenty male White New Zealand rabbits were used in this study. In autograft group the defect was filled by fresh autogenous cortical graft, in xenograft group the defect was filled by a segment of bovine fetal growth plate and was fixed by cercelage wire. Radiological, histopathological and biomechanical evaluations were performed blindly and results scored and analyzed statistically. Statistical tests did not support significant differences between two groups at the 14th and 28th postoperative day radiographically (P > 0.05). There was a significant difference for remodeling at the 42nd postoperative radiologically (P < 0.05). Xenograft was superior to autograft at the 56th postoperative day for radiological bone formation (P < 0.03). Histopathological and biomechanical evaluation revealed no significant differences between two groups. The results of this study indicate that satisfactory healing occurred in rabbit radius defect filled with calf fetal growth plate. Complications were not identified and healing was faster than cortical autogenous grafting. It was concluded that the use of calf fetal growth plate as a new xenograft is an acceptable alternative to cortical autogenous graft and could reduce the morbidity associated with harvesting autogenous graft during surgery.  相似文献   

3.
《Cytotherapy》2014,16(6):857-867
Background aimsSuture anchor fixation failure has been reported as a result of anchor loosening and migration during the tendon-bone repair. The aim of this study was to evaluate the effects of bone morphogenetic protein-2 (BMP-2) inserted into the suture anchor hole on bone formation and the tendon-bone healing.MethodsBoth back legs of 24 New Zealand White rabbits (n = 48) were used in this study. A metal suture anchor was then placed 5 mm below the cortex. In the control group, the space over the eyelet of the anchor (suture anchor hole) was not filled. In the experimental group, the suture anchor hole was filled with 0.1 mL of fibrin glue (group 2) or collagen gel (group 3) with 1 μg BMP-2. Histologic analysis, real-time-polymerase chain reaction, bone density and failure load measurement were performed, and differences were analyzed at 4 and 8 weeks.ResultsHistologic analysis revealed more abundant new bone, mature bone and organized fibrocartilage at the tendon-bone interface at 4 and 8 weeks in groups in which BMP-2 was applied. At 8 weeks, the failure load of groups 1, 2 and 3 was significantly different among the three groups (P = 0.01). After post hoc Tukey test, the failure load of group 2 was significantly higher than that of group 1 (P = 0.01).ConclusionsBMP-2, administrated as described in this study, improved tendon-bone healing and bone formation, resulting in improved biomechanical strength of the tendon-bone junction.  相似文献   

4.
Vascularized and conventional autogenous rib grafts were used to reconstruct 6-cm ulnar defects in the forelegs of the nine dogs. Each dog served as its own control. Biomechanical torsional testing of the grafted ulnas showed that vascularized grafts were 234 percent stronger than the conventional grafts. Bone toughness (energy absorbed) was 483 percent greater in the vascularized grafts, and elastic modulus and proportional limits were 263 and 246 percent greater, respectively. We conclude that vascularized bone grafts are significantly stronger than conventional autogenous bone grafts after 3 months of healing in the dog ulna model.  相似文献   

5.
硫酸钙作为微小颗粒骨载体的实验研究   总被引:1,自引:0,他引:1       下载免费PDF全文
目的:研究硫酸钙作为微小颗粒骨载体,解决微小颗粒骨的自身缺点的实际效果,为其临床应用提供依据。方法:将49只日本大耳白兔随机分成4组并通过手术造成双侧桡骨中段1.5cm骨缺损,以植入硫酸钙为载体的自体微小颗粒骨为实验组,同时设立单纯植入自体微小颗粒骨,单纯植入硫酸钙和不植入任何物质的空白对照组。术后4周和8周分别行大体观察。X线摄片,组织学观察,骨生物力学测定。结果:以硫酸钙为栽体的自体微小颗粒骨组比单纯自体微小颗粒骨组及单纯硫酸钙组能更有效地修复骨缺损,单纯颗粒骨组成骨效果优于单纯硫酸钙组。空白组无骨愈合迹象;组织学观察示以硫酸钙为载体的自体微小颗粒骨实验组的成骨效果最好,单纯自体微小颗粒骨组次之;生物力学测定证明以硫酸钙为载体的自体微小颗粒骨实验组的力学强度优于单纯自体微小颗粒骨组及单纯硫酸钙组。结论:硫酸钙是微小颗粒骨的优良载体,以硫酸钙为载体的自体微小颗粒骨成骨速度快,成骨量多,质量高,骨的机械强度高,修复骨缺损的能力较单纯应用微小颗粒骨和硫酸钙强;二者结合可充分发辉各自的优势。  相似文献   

6.

Aims

Our study was intended to evaluate the role of inducible nitric oxide synthase (iNOS), endothelial nitric oxide synthase (eNOS), caspases 1 and 3 and calpain 1 in the pathogenesis of contrast-induced nephropathy (CIN) and to compare the protective effects of N acetyl cysteine (NAC) and grape seed proanthocyanidin extract (GSPE) against the development of CIN.

Main methods

32 rats were divided into four groups; control, contrast media (CM), CM + NAC and CM + GSPE. CIN was induced by administration of 7 ml/kg diatrizoate. The experiment was discontinued on the ninth day. Blood was collected for blood urea nitrogen (BUN) and creatinine measurement. Rat kidney tissues were removed for histopathological evaluation and the investigation of caspases 1 and 3, iNOS, eNOS, TUNEL and calpain 1.

Key findings

A significant increase in BUN, creatinine, renal histopathological injury, TUNEL, caspases 1, 3, calpain 1, iNOS and eNOS was observed in the CM group compared to the control group. There was amelioration in all these parameters in the CM + GSPE group, while there was no significant amelioration in BUN, creatinine and renal histopathological injury in the CM + NAC group. In addition, calpain 1 staining and creatinine were significantly lower in the CM + GSPE group compared to the CM + NAC group.

Significance

Our study showed, for the first time in the literature, that GSPE has a greater renoprotective effect compared with NAC and that this effective protection may be related to decrease in calpain 1 levels.  相似文献   

7.
Little is understood about the role of the recipient site in the revascularization and incorporation of autogenous inlay bone grafts in the craniofacial skeleton. Clinical experience demonstrates that secondary complex cranial vault reconstruction performed with scarred avascular dura or poor soft-tissue coverage may undergo significant resorption, thus compromising the aesthetic outcome. This study was designed to determine the effect of isolating autogenous orthotopic inlay calvarial bone grafts from the surrounding dura and/or periosteum on graft revascularization, healing, and volume maintenance in the adult rabbit. Adult rabbits were randomized into four groups (n = 10 per group); in each rabbit, the authors created a circular, 15-mm in diameter, full-thickness cranial defect followed by reconstruction with an autogenous calvarial bone graft, which was replaced orthotopically and held with microplate fixation. Silicone sheeting (0.5 mm thickness) was used to isolate the dura (group II), the periosteum (group II), or both dura and periosteum (group IV) from the graft interface. No silicone was placed in group I. Animals were killed 10 weeks postoperatively, and calvaria were harvested to assess graft surface area, morphology, quantitative histology, fluorochrome staining, and revascularization. Grafts isolated from both the dura and periosteum exhibited significant decreases in total bone (cortical and trabecular) surface area, blood vessel count, and interface healing compared with nonisolated control grafts. Isolation of either the dura or periosteum significantly (p < 0.05) decreased blood vessel count but had no significant effect on interface healing. Isolation of the dura alone was associated with a significant (p < 0.05) decrease in graft cross-sectional surface area and dural cortical thickness compared with nonisolated control grafts, but this effect was not observed when the periosteum alone was isolated. Quantitative histology performed 10 weeks after surgery indicated that graft isolation was associated with increased marrow fibrosis and necrosis compared with nonisolated controls; it also demonstrated evidence of increased activity in bone remodeling (osteoblast and osteocyte count, new trabecular bone, and surface resorption). Triple fluorochrome staining suggested increased bone turnover in the nonisolated grafts compared with isolated grafts at 1 and 5 weeks postoperatively. This study demonstrates that isolating a rabbit calvarial inlay autogenous bone graft from the dura and/or periosteum results in significantly (p < 0.05) decreased revascularization, interface healing, and cross-sectional areas of amount of mature bone compared with nonisolated control grafts 10 weeks after surgery. At this time point, histologic examination demonstrates a paradoxical increase in bone remodeling in isolated bone grafts compared with controls. It is possible that the inhibition of revascularization results in a delayed onset of the remodeling phase of graft incorporation. However, in the model studied, it is not known whether the quantitative histologic and morphometric parameters measured in these isolated grafts exhibit a "catch-up" phenomenon at time points beyond 10 weeks after surgery. The results of this study emphasize the importance of a healthy recipient site in the healing and incorporation of calvarial bone grafts but stress the need for further investigation at later time points.  相似文献   

8.
Our purpose was to investigate the relationship between running volume and bone mineral mass in adult male runners. Whole body and regional bone mineral density were determined by dual-photon absorptiometry in 22 sedentary controls and 53 runners who were selected according to their running mileage to fall into a 5- to 10-, 15- to 20-, 25- to 30-, 40- to 55-, or 60- to 75-mile/wk group. All groups were of similar age (20-45 yr) and nutritional status, as determined by 7-day food records. Regional sites for bone density measurements included the trunk, spine, pelvis, thighs, and lower legs. In addition, serum total testosterone was determined in each subject and computed tomography scans were made of the lower legs in 34 subjects to assess bone cross-sectional area. No significant differences were detected for bone density measurements with the exception of the lower legs where it was significantly (P less than 0.05) greater for the 15- to 20-mile/wk group than for the control and 5- to 10-mile/wk groups. With mileage greater than 20 miles/wk, bone density of the lower legs showed no further increase and, in fact, tended to decrease, so that for the 60- to 75-mile/wk group it was similar to that of the controls. Cross-sectional area of the tibia and fibula when normalized to body weight tended to be greater as weekly mileage increased and was significantly greater in the 40- to 55-mile/wk runners than in the control group.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

9.
目的:探讨采用3D适形打印技术制备的羟基磷灰石/聚乳酸网状复合体在兔颅骨缺损中的修复作用及安全性。方法:以24只新西兰兔为研究对象,以羟基磷灰石/聚乳酸为材料,采用3D适形打印技术制备网状复合体,于兔颅骨顶部制成两个颅骨全层缺损,分别为孔A(左)和孔B(右),孔A(阳性对照组)以自体颅骨为修复材料,孔B(实验组)以复合体为修复材料,观察缺损修复区域的形态学、影像学(X线及CT扫描)及组织学检查结果。结果:植入后24周时,形态学显示:阳性对照组可见致密的骨组织修复,与缺损边缘界限不清,实验组中支架孔隙内纤维组织由新生骨质取代,且新生骨成熟度较提高,材料表面有部分吸收。CT扫描观察显示:冠状面上,阳性对照组缺损修复区域与周围正常骨组织融合为一体,实验组修复材料与缺损边缘融合紧密,与周围正常骨组织结合良好,部分边缘结合不连贯。组织学观察显示:实验组材料部分降解,材料间隔可见新生骨小梁。研究中无实验动物死亡,皮肤切口处缝合良好,无皮下积液,无移植物脱出、红肿感染等情况出现。结论:以3D适形打印技术制备的羟基磷灰石/聚乳酸复合体对兔颅骨缺损有较好的修复作用,能促进缺损区域新骨的形成和生长,且安全性较高。  相似文献   

10.
Promotion of wound healing by yeast glucan evaluated on single animals   总被引:3,自引:0,他引:3  
M Wolk  D Danon 《Medical biology》1985,63(2):73-80
The effectiveness of yeast glucan in the acceleration of wound healing was evaluated in mice, rats and guinea pigs. In all experiments comparison between glucan treatment in one hind leg and saline treatment as control on the other leg was made on identical wounds. The degree of healing in the two legs was evaluated macroscopically and classified as follows: 1. healing more advanced in glucan treated wound marked by (+). 2. No significant difference between the two legs marked by (0). 3. Healing more advanced in the control wound, marked by (-). During the days when the differences were most obvious, 60% to 80% of the animals showed more advanced healing in the glucan treated wound, 20% to 40% showed no significant difference; and 0 to 15% showed more advanced healing in the control, saline treated wound. The average time for complete wound healing was reduced by about 18% as a result of glucan treatment. The histological analysis shows that the acceleration of wound healing was mediated by early arrival of macrophages to the wound area in the glucan treated wounds.  相似文献   

11.
The aim of this study was to evaluate the healing of class III furcation defects following transplantation of autogenous periosteal cells combined with β-tricalcium phosphate (β-TCP). Periosteal cells obtained from Beagle dogs’ periosteum explant cultures, were inoculated onto the surface of β-TCP. Class III furcation defects were created in the mandibular premolars. Three experimental groups were used to test the defects’ healing: group A, β-TCP seeded with periosteal cells were transplanted into the defects; group B, β-TCP alone was used for defect filling; and group C, the defect was without filling materials. Twelve weeks post surgery, the tissue samples were collected for histology, immunohistology and X-ray examination. It was found that both the length of newly formed periodontal ligament and the area of newly formed alveolar bone in group A, were significantly increased compared with both group B and C. Furthermore, both the proportion of newly formed periodontal ligament and newly formed alveolar bone in group A were much higher than those of group B and C. The quantity of cementum and its percentage in the defects (group A) were also significantly higher than those of group C. These results indicate that autogenous periosteal cells combined with β-TCP application can improve periodontal tissue regeneration in class III furcation defects.  相似文献   

12.
Delayed wound healing is a common complication in diabetes mellitus. From this point of view, the main purpose of the present study is to investigate the effect of extremely low frequency pulsed electromagnetic fields (ELF PEMFs) on skin wound healing in diabetic rats. In this study, diabetes was induced in male Wistar rats via a single subcutaneous injection of 65 mg/kg streptozocin (freshly dissolved in sterile saline, 0.9%). One month after the induction of diabetes, a full‐thickness dermal incision (35 mm length) was made on the right side of the paravertebral region. The wound was exposed to ELF PEMF (20 Hz, 4 ms, 8 mT) for 1 h per day. Wound healing was evaluated by measuring surface area, percentage of healing, duration of healing, and wound tensile strength. Obtained results showed that the duration of wound healing in diabetic rats in comparison with the control group was significantly increased. In contrast, the rate of healing in diabetic rats receiving PEMF was significantly greater than in the diabetic control group. The wound tensile strength also was significantly greater than the control animals. In addition, the duration of wound healing in the control group receiving PEMF was less than the sham group. Based on the above‐mentioned results we concluded that this study provides some evidence to support the use of ELF PEMFs to accelerate diabetic wound healing. Further research is needed to determine the PEMF mechanisms in acceleration of wound healing in diabetic rats. Bioelectromagnetics 31:318–323, 2010. © 2010 Wiley‐Liss, Inc.  相似文献   

13.
《Phytomedicine》2011,18(5):356-361
The aim of this study was to investigate the possible protective effects of lycopene (LC) and ellagic acid (EA) on cisplatin (CP)-induced testicular apoptosis in male rats. The control group was treated with placebo; LC, EA and CP groups were given alone LC, EA and CP, respectively; the CP + LC group was treated with a combination of CP and LC; and the CP + EA group was treated with a combination of CP and EA. Although CP significantly increased the number of Bax-positive (apoptotic) cells it had no effect on the number of Bcl-2-positive (antiapoptotic) cells compared with the control group. Administration of CP caused significant increase in lipid peroxidation and nonsignificant decrease in superoxide dismutase (SOD) activity along with some histopathological lesions in testicular tissue. However, combined treatments of LC or EA in addition to CP tended to prevent the CP-induced testicular apoptosis, histopathological lesions and lipid peroxidation.  相似文献   

14.
目的:探究强骨胶囊对老年股骨头近段骨折延迟愈合患者血清骨形态发生蛋白-2(BMP-2)及胰岛素生长因子-1(IGF-1)水平的影响。方法:选择我院收治的股骨近端骨折延迟愈合的老年患者41例,随机分为实验组及对照组。对照组19例予钙片;实验组22例予强骨胶囊。对比两组的临床疗效及治疗前后血清BMP-2及IGF-1水平的改变。结果:实验组总有效率(95.5%)高于对照组(78.9%),差异具备统计学意义(P0.05)。两组血清BMP-2及IGF-1水平均较治疗前显著升高(P0.05),且实验组血清BMP-2和IGF-1水平较对照组高(P0.05)。治疗后,两组血浆粘度均下降、骨密度值(BMD)均升高(P0.05);与对照组相较,实验组血浆粘度降低、BMD较高(P0.05)。结论:强骨胶囊能够有效改善老年股骨头近段骨折延迟愈合,促进骨折断端的愈合,推测其机制与增加患者血清BMP-2及IGF-1水平有关。  相似文献   

15.
16.
BackgroundBoron nitride is a biocompatible and an osteo-inductive material for orthopedic applications. The aim of this study was to evaluate the effects of two different allotrope boron nitride coated implants, cubic boron nitride and hexagonal boron nitride, on fracture healing.MethodsIn this experimental study, a total of 24 rats were divided into three groups. Group A was the control group with Kirschner wire without coating, while the wires were coated dominantly by cubic boron nitride in Group B and hexagonal boron nitride in Group C. Then a mid-third femoral fracture was created. The fracture healing was examined in terms of new bone formation with micro-CT analysis and histopathological examination, quantitative measurement of bone turnover metabolites and scintigraphic examination of osteoblastic activity on 28th day post fracture.ResultsMicro-CT measurement results revealed a statistically significant increase in bone volume/tissue volume ratio and bone surface values in group B compared to group A. Cortex diameter and osteoblast counts were statistically higher in group B compared to group A. Inflammatory response was increased in group C compared to groups A and B. Biochemical test results showed significantly increased alkaline phosphatase levels and decreased osteocalcin levels in group B compared to group A. The increase in serum phosphorus and decrease in serum calcium levels was statistically significant in group C compared to Group A.ConclusionBoth types of boron nitride coating had superior fracture healing features compared to control group. Therefore, c-BN coating can accelerate the fracture healing and could lead to shorten of union time.  相似文献   

17.
目的:探讨富血小板纤维蛋白(PRF)联合人工骨粉(Bio-Oss骨粉)在口腔种植引导性骨再生中的临床应用价值。方法:选取2017年6月到2018年6月期间在我院接受口腔种植引导性骨再生手术治疗的患者80例,根据随机数字表法分为对照组(40例)和研究组(40例),对照组采用Bio-Oss骨粉联合Bio-Gide生物膜进行干预,研究组采用Bio-Oss骨粉联合PRF进行干预。比较两组患者的组织愈合情况、出血指数、探诊深度、附着丧失、植体周围的骨密度、植骨高度、成骨厚度和术后并发症。结果:研究组的组织愈合优良率为95.00%,高于对照组的80.00%,差异有统计学意义(P0.05)。研究组患者的出血指数、探诊深度、附着丧失均低于对照组,种植体周围的骨密度、成骨厚度均明显大于对照组,植骨高度高于对照组,差异有统计学意义(P0.05)。两组患者的并发症发生率比较差异无统计学意义(P0.05)。结论:PRF联合Bio-Oss骨粉可有效增加种植区骨量和种植体周围的骨密度,促进骨缺损再生和组织愈合,且无明显的并发症,在口腔种植引导性骨再生中有较好的临床应用价值。  相似文献   

18.
Effects of small vibration stimuli on bone formation have been reported. In the present study, we used morphological and morphometric procedures to elucidate whether low-magnitude, high-frequency (LMHF) vibration stimuli could enhance the bone healing of rat incisor extraction sockets. After extraction of incisors from six-week-old rats, animals were assigned into a control group and two experimental groups to receive 50?Hz stimuli at either 0.05?mm or 0.2?mm peak-to-peak for an hour/day. LMHF vibration stimuli were generated by placing the mandibles of the animals onto a vibration generator. All groups were subdivided into two, according to the study periods (1 and 3 weeks). After the study period, undecalcified ground sections were taken and morphological and morphometric analyses performed. At both 1 and 3 weeks, newly formed bone was observed mainly in the upper wall of the extraction socket in all groups. Morphometric analyses revealed that the trabecular thickness in both experimental groups at 1 week was significantly greater than that in the control. LMHF vibration stimuli had a positive effect on bone at the early stage of bone healing, particularly in trabecular thickness, at the incisor extraction socket.  相似文献   

19.
目的探讨低强度脉冲超声波辐照对节段性骨缺损修复效果的影响。方法将直径12 mm长20mm泡沫TiC/Ti植入6只Beagle犬的左侧胫骨节段性骨缺损区。随机分为超声组和对照组,超声组采用低强度脉冲超声波辐照(频率1.5 MHz、强度30 mW/cm2、脉冲宽度200μs、脉冲周期1 kHz、20 min/次、1次/d),对照组为不开功率源的假辐照,术后4、8周后分别行X线检查及骨密度测定,观察及分析材料周围骨愈合情况。结果 6只beagle犬均进入结果分析。术后4周超声组骨早期成熟度优于对照组,表现在材料周围骨痂影密度增高,骨痂影由两端向中央生长;对照组仅见骨痂区密度低,还可见部分骨痂缺如。术后8周超声组新生骨痂面积优于对照组,骨干结构相对稳定;对照组骨缺损区未闭合,在骨干两侧看到少量骨痂,愈合较差。骨密度测定结果显示,4周时超声组高于对照组,两组间存在统计学差异;8周时超声组略高于对照组,但两组间没有统计学差异。结论通过联合应用低强度脉冲超声波辐照与人工骨材料修复可提高新骨形成速度及骨组织密度,缩短节段性骨缺损的骨愈合时间。  相似文献   

20.
目的:评价富血小板血浆联合同种异体骨治疗非感染性骨不连的临床疗效。方法:回顾性分析我院创伤骨科2010年2月-2015年1月的非感染性骨不连患者,比较同种异体骨加富血小板血浆混合物与自体髂骨植骨治疗非感染性骨不连的疗效。结果:两组共随访非感染性骨不连患者69例,全部进行了术中断端植骨,其中富血小板血浆联合同种异体骨植骨组(PRP组)21例,其中愈合19例,未愈合2例,临床愈合率90.5%。自体髂骨植骨组(自体骨组)48例,愈合44例,4例未愈合,临床愈合率91.6%。PRP组平均手术持续时间为(108.73±13.91),自体骨组为(120.54±13.87)min,两组间有统计学意义(P0.05)。术后3月,PRP组患者X线骨痂评价标准平均评分值为(2.54±0.43)分,自体骨组为(2.62±0.45)分,两组间差异无统计学意义(P0.05)。结论:富血小板血浆混合同种异体骨植骨治疗骨不连较传统自体髂骨植骨可缩短手术时间,避免供骨区并发症,修复效果良好,为骨不连的治疗提供了一个新的方法。  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