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1.
以硅橡胶为基体、锂瓷石粉和硼砂为烧结助剂,采用机械共混法,制备了具有陶瓷化防火功能的硅橡胶复合材料。通过力学测试、热重分析(TG)、X射线衍射(XRD)和扫描电子显微镜(SEM)表征了该材料的结构、力学性能和烧结性能,研究了锂瓷石粉和硼砂对陶瓷硅橡胶复合材料性能的影响。结果表明:通过在体系中添加锂瓷石粉和硼砂,提高了硅橡胶复合材料的力学性能,降低了陶瓷化硅橡胶复合材料的起始分解温度,加快了烧结反应进程。当锂瓷石粉与硅橡胶的质量比为5:100时,硅橡胶复合材料的综合力学性能最好,拉伸强度、断裂伸长率,撕裂强度分别提高了15.6%、34.8%、2.3%,添加锂瓷石粉的陶瓷复合材料经过烧结,能够形成均匀的陶瓷化整体结构,比添加硼砂的陶瓷化硅橡胶复合材料具有更好的烧结性能。 相似文献
2.
Plat铸造陶瓷的生物相容性试验 总被引:1,自引:1,他引:0
采用溶血试验、细胞毒性试验和急性短期口服毒性试验,对新型牙科材料plat铸造陶瓷的生物相容性进行评价,结果表明:Plat铸造陶瓷平均溶血率为3.93%,按ISO标准属于正常范围(<5%);Plat铸造陶瓷对体外培养的L929细胞的生长、附着和增殖无明显抑制作用;将Plat铸造陶瓷生理盐水悬浮液给小白鼠灌胃,动物未出现全身毒性症状,生长发育未受到不良影响。 相似文献
3.
目的 本研究采用医用硅橡胶经聚四氟乙烯(PTFE)改性,用于制备植入体内的新型腹腔化疗管复合材料.方法 对其材料进行物理机械性能、动物试验安全性进行评价.结果 PTFE添加最对复合材料硬度的影响不大,随着PTFE含量增加,复合材料仍保持较高的物理机械性能;复合材料通过过敏试验、热源试验、全身急性毒性试验表明,所制备的复合材料在生物学评价试验中均呈阴性反应,材料无明显毒性,材料中不存在潜在致敏性物质,所含热原含量符合生物体的要求.具有优良的生物相容性.结论 本文所制备的硅橡胶/PTFE复合材料具有较高的物理机械性能和优良的生物相容性,是制备腹腔化疗导管的良好材料. 相似文献
4.
目的 依据相关标准初步评价自制CPC纳米复合材料的生物相容性,为材料的最终临床应用提供实验依据.方法 根据YY/T 0127.1-93和YY/T 0244-1996标准,用体外溶血试验及经口途径短期全身急性毒性试验评价自制CPC纳米复合材料的安全性.结果 自制材料浸提液对健康人血红细胞溶血率为0.1%(<5%),无溶血现象;经口途径短期全身急性毒性试验的大鼠每周食物利用率及体质量相对增长率与对照组之间均差异无统计学意义(P>0.05),心、肾、肝等重要脏器肉眼观察无异常改变,其组织切片未出现病理学变化.结论 自制CPC纳米复合材料生物相容性符合国内的体内植入物的生物学评价标准,具有良好的生物相容性. 相似文献
5.
双相生物陶瓷/硅橡胶复合材料的各项生物力学性能检测 总被引:3,自引:0,他引:3
目的对新型钙磷类活性材料——双相生物陶瓷(BCP)与硅橡胶(SR)的复合物进行硬度、生物力学性能测定与分析,筛选出二者最佳的复合质量配比,进行下一步生物学评价。方法对不同比例(30-BCP、50-BCP、70-BCP)的双相生物陶瓷/硅橡胶复合物按国家标准(GB/T528)要求对其进行硬度(邵氏A)、抗拉强度、弹性模量、屈服强度、断裂伸长率、断裂强度测定,对其机械性能加以评价,并进行统计学分析。结果随着硅橡胶内双相生物陶瓷含量的增加,硅橡胶的硬度逐渐提高,各项机械性能逐渐下降。结论双相生物陶瓷/硅橡胶复合材料中BCP含量为30~50份时,机械性能与纯硅橡胶相当,而BCP含量为50份以上时性能下降明显,不宜用于体内填充。 相似文献
6.
目的:对储存式多孔聚乳酸/β-磷酸三钙(PDLLA/β-TCP)复合材料载体进行生物学评价。方法:采用热致相分离/冷冻干燥法制备储存式多孔PDLLA/β-TCP复合材料载体,通过对载体的结构表征和体外细胞毒性试验、急性全身毒性试验、溶血试验、皮肤刺激试验、微核实验以及动物体内植入试验进行生物学评价,为其临床应用提供生物学依据。结果:①储存式多孔PDLLA/β-TCP复合载体材料具有多孔结构,孔径约60!m,孔率71.9%;②材料浸提液对3T3细胞的相对增殖率(RGR)大于81.3%,无细胞毒性(Ⅰ级);急性全身毒性试验阴性;受试材料溶血率小于2.20%,体外试验不引起溶血反应;皮肤刺激性无红斑、无水肿出现;微核率(1.4±0.8)%,与阴性对照组比较,P>0.05;肌肉植入8周后,纤维包膜完整地包绕PDLLA/β-TCP多孔微管。结论:采用热致相分离/冷冻干燥法制备的此种新颖的储存式多孔PDLLA/β-TCP复合载体材料具有良好的生物相容性。 相似文献
7.
目的采用医用硅橡胶经聚四氟乙烯(PTFE)改性复合材料制备植入体内的多功能腹腔化疗管,对其材料进行物理机械性能及动物试验安全性评价。方法用健康成年新西兰兔对复合材料进行过敏试验、热源试验、全身急性毒性试验。结果制备多功能腹腔化疗管的复合材料在生物学评价试验中均呈阴性反应,材料无明显毒性,材料中不存在潜在致敏性物质,所含热原含量符合生物体的要求。结论制备多功能腹腔化疗管的复合材料具有优良的生物相容性。 相似文献
8.
目的探讨钛基表面羟基磷灰石/纳米银(HA/Ag)复合涂层的组织相容性,为进一步临床研究和应用奠定基础。方法应用脉冲电泳方法,根据不同浓度的钙-磷-银电解液,在钛金属表面沉积3种复合涂层材料。按国家和ISO对生物材料相容性的检测标准,检测钛基表面HA/Ag复合涂层的生物相容性。以新西兰兔、昆明小鼠进行热原试验、皮肤刺激试验、急性毒性试验和溶血试验。结果静脉注射材料浸提液后,兔体温升高值<0.6℃。浸提液皮内注射法及划痕法观察72 h,兔局部皮肤无红肿、渗出、溃烂等刺激反应。腹腔注射浸提液后,小鼠未出现异常症状,体质量有增加趋势。3种材料溶血率均低于生物医用材料溶血国际标准(5%)。结论在钛基表面沉积制备的HA/Ag纳米复合材料,具有良好的组织相容性。 相似文献
9.
目的使用不同复合工艺制备α-半水硫酸钙/β-磷酸三钙复合人工骨材料,与WRIGHT公司生产的硫酸钙Osteoset进行理化特性和生物相容性的比较.方法对不同工艺制备的α-半水硫酸钙/β-磷酸三钙复合人工骨材料(根据工艺不同分为A、B组)及Osteoset(C组),进行X射线衍射分析、微观形貌观察及体外细胞毒性实验、溶血实验、热原反应检测,同时对人工骨材料进行肌肉包埋实验,对3种材料进行对比研究.结果X线衍射分析显示,各组材料出现各自的特征性衍射峰,未出现新的衍射峰;透射电镜微观形态观察提示,各组均呈现较多相互联通的平行的大孔结构,孔隙分布均匀,孔隙结构之间贯通性良好,晶体结构形态相对均匀一致等特点.体外细胞毒性实验提示:A、B、C组各时间点RGR值均大于75%,各实验组毒性分级为Ⅰ级,阴性对照组毒性级别为0级,阳性对照组毒性级别为Ⅳ级.溶血实验示:A组、B组、C组平均溶血率为分别为0.95%、2.22%、1.05%.热原实验示:A组各时间点体温升高0.2℃,体温升高总和为0.4℃;B组各时间点体温升高0.1 ~0.2℃,体温升高总和为0.3℃;C组各时间点体温升高0.1 ~0.2℃,体温升高总和为0.3 ℃.各实验组体温升高均小于0.6℃,体温升高总和小于1.3℃.人工骨材料肌肉包埋,组织学检查显示肌纤维组织生长结构正常,无明显炎症细胞浸润,无排异反应.各组对细胞生长、增殖无影响,未发现溶血、热原反应及局部炎症反应,是理想的骨替代材料.结论 自制的两种复合人工骨材料均表现出良好的生物相容性,是一种具有潜在临床应用前景的新型人工骨材料. 相似文献
10.
由异种骨制备的多相钙磷陶瓷肌内降解性能的研究 总被引:2,自引:0,他引:2
目的:观察两种不同比例羟基磷灰石(HAP)/β-TCP/NaCaPO4的多相钙磷陶瓷降解情况。方法:通过物理、化学方法将煅烧的鸵鸟松质骨转化为HAP/β-TCP/NaCaPO4多相钙磷陶瓷。通过不同剂量焦磷酸钠处理得到不同比例的HAP/β-TCP/NaCaPO4陶瓷,然后将陶瓷材料植入兔背部肌袋内,未处理的煅烧骨植入作为对照。于4、12、24周取材,测定材料降解率(失重率),从大体、组织学观察以了解材料降解情况。结果:随着β-TCP和NaCaPO4比例的增加,材料降解率提高。植入后4周材料轻度降解,12、24周降解加快,24周的组织学切片观察显示HAP/β-TCP/NaCaPO4陶瓷崩解。崩解后的材料碎片散在于新生纤维组织间隙内。部分区域材料几乎全部吸收,并被纤维组织所取代。结论:制备的鸵鸟多相钙磷陶瓷在肌肉内有部分降解性能,通过控制HAP/β-TCP/NaCaPO4的比例可获得不同降解速率的陶瓷材料。 相似文献
11.
Objective: To evaluatel the value of D-dimers in patients with acute aortic dissection (AAD). Methods: This study consisted of 16 patients with AAD and 27 non-AAD patients. Serum D-dimets were measured by Sta-Liatest D-DI immunoturbidimetric assay. Results: D-dimer level was higher (P < 0.001) in patients with AAD(7.91 ± 5.52 μg/ml) than that in non- AAD group(1.57±1.24 μg/ml). D-dimer was positive (>0.4 μg/ml) in all patients with AAD and in 10 control group patients (37%). Among patients with acute AAD, D-dimers tended to be higher in Stanford A than in Stanford B (8.67 ± 4.31 μg/ml vs. 3.24±1.27 μg/ml, P <0.01). D-dimer values tended to be higher in more extended disease(3.84 ± 1.65 μg/ml, 8.57 ± 3.58 μg/ml and 11.87 ± 5.69 μg/ml in thoracic aorta, thoracic and abdominal aorta, thoracic and abdominal aorta and iliacal arteries, respectively, P < 0.05 for both 8.57 ± 3.58 and 11.87 ± 5.69 vs. 3.84 ± 1.65 ). Including the control group into the analysis, we found a sensitivity of 100%, a negative predictive value of 100%, and a specificity of 66% and a positive predictive value of 64% for D-dimer in diagnosis of AAD in our patients with suspected AAD. Conclusion: D-dimer was elevated in patients with AAD. A negative D-dimer test result could be useful in excluding AAD. 相似文献
12.
Jiageng Zhu Jun Li Ruipeng Ji Jianghao Su Mingshun Shen Zhigang Cao 《南京医科大学学报(自然科学版)》2007,21(2):125-128
Objective: To set up a simple and reliable rat model of combined liver-kidney transplantation. Methods: SD rats served as both donors and recipients. 4℃ sodium lactate Ringer's was infused from portal veins to donated livers,and from abdominal aorta to donated kidneys, respectively. Anastomosis of the portal vein and the inferior vena cava (IVC) inferior to the right kidney between the graft and the recipient was performed by a double cuff method, then the superior hepatic vena cava with suture. A patch of donated renal artery was anastomosed to the recipient abdominal aorta. The urethra and bile duct were reconstructed with a simple inside bracket. Results: Among 65 cases of combined liver-kidney transplantation, the success rate in the late 40 cases was 77.5%. The function of the grafted liver and kidney remained normal. Conclusion: This rat model of combined liver-kidney transplantation can be established in common laboratory conditions with high success rate and meet the needs of renal transplantation experiment. 相似文献
13.
Tao Ye * Zhi-quan Liu Jian-jun Mu Xi-han Fu Jun Yang Bao-lin Gao and Xiao-hong Zhang Department of Cardiology First Hospital of Xi'an Jiaotong University Xi'an Hanzhong Cardiovascular Institute Hanzhong 《中国医学科学杂志(英文版)》2004,19(4):248-251
Objective To observe blood pressure change with age in salt-sensitive teenagers whose salt sensitivity were determined by repeated testing.Methods Salt sensitivity was determined through intravenous infusion of normal saline combined with volume-depletion by oral diuretic furosemide in 55 teenagers. After five years, salt sensitivity was re-examined and subject blood pressure was followed up. Blood pressure changes in salt-sensitive teenagers were compared to that of non-salt sensitive teenagers over five years.Results After 5 years, the repetition rate of salt sensitivity determined by intravenous saline loading is 92.7%. In teenagers with salt sensitivity on the baseline, both the systolic blood pressure increments and increment rates were much higher than non-salt sensitive teenagers (12.7±12.1 mmHg vs. 2.8±5.2 mmHg, P< 0.01; 12.2%± 12.0% vs. 2.5% ±4.4%, P< 0.001,respectively). There was a similar trend for diastolic blood pressure (8.4 ± 6.4 mmHg vs. 3.7 ± 6.4 mmHg, P = 0.052; 13.2% ±10.6 % vs. 6.8%± 10.1%, P = 0.053, respectively).Conclusions Salt sensitivity determined by intravenous saline loading showed good reproducibility. Blood pressure increments with age were much higher in salt-sensitive teenagers than non-salt sensitive teenagers, especially in terms of systolic blood pressure. 相似文献
14.
目的:评价使用安心颗粒对急诊经皮冠状动脉介入术(PPCI)术后生活质量的影响.方法:将160例接受PPCI的急性ST段抬高型心肌梗死患者随机分为安心颗粒组(术前顿服安心颗粒8.8g,术后安心颗粒4.4 g/次,每日2次)和对照组(仅接受基础药物治疗).所有患者均服用阿司匹林、氯吡格雷和阿托伐他汀.分别在入院时、出院前1d、出院后180 d时,应用心肌梗死多维度量表(MIDAS)、中文版SF-36评价量表对患者生活质量评分.并观察术后30 d以内的出血并发症、血小板减少症发生情况.结果:入院时和出院前1d,两组患者的心肌梗死MIDAS、SF-36量表评分比较无差异(P>0.05);出院后180 d时,与对照组比较,安心颗粒组MIDAS、SF-36评分明显减低(P<0.05);组内与入院时比较,两组出院前1d、出院后180 d时,MIDAS、SF-36评分均降低(P<0.05).两组患者在随访期间均无大量出血、少量出血、重度和极重度血小板减少症发生,安心颗粒组有4例、对照组有7例发生不明显出血(P>0.05).两组发生轻度血小板减少症的患者数比较无差异(P>0.05).结论:PPCI使用安心颗粒,能改善急性ST段抬高型心肌梗死患者的生活质量,且不增加出血风险. 相似文献
15.
Jingming Zhu Ningning Hui Xiuhong Jiang Huaxing Zhang Chengzhang Fu 《南京医科大学学报(自然科学版)》2007,21(6):386-389
Objective:To investigate the influences of urapidil and nicardipine on rabbit sinus function,atrio-ventricular node function and hemodynamics.Methods:Thirty-two Angora's rabbits were selected and randomly divided into four groups.U1 group:urapidil 0.25 mg/kg;U2 group:urapidil 0.5 mg/kg;N1 group:nicardipine 10 μg/kg;N2 group:nicardipine 20 μg/kg.All these medicine were administrated within 30 seconds.Measurements were taken before and after the administration of urapidil or nicardipine for the following data:mean blood pressure(MAP),heart rate(HR),sino-atrial conduction time(SACT),maximal sinoatrial recovery time(SNRTmax)corrected sinus node recovery time(CSNRT),index of sinus node recovery time(SNRTI),Wenckebach A-V conduction frequency (WB),and P-R interval.Results:Significant MAP and HR changes were identified in all of the four groups before and after administration of both urapidil and nicardipine.No significant changes could be found in the rest of the parameters.Intergroup analysis showed that SACT and CSNRT of N1 and N2 groups were shorter than those of the U2 group(P<0.01);the MAP decreased(P<0.01)and the HR increased drastically(P<0.01).Conclusions:Neither urapidil(0.25 mg/kg,0.5 mg/kg)nor nicardipine(10μg/kg,20μg/kg)has any significant influence on rabbit sinus function or rabbit atrio-ventricular node function.Nicardipine could be a better choice than urapidil for parafunctional sinus node patients. 相似文献
16.
Objective:To investigate the gene expression of osteoprotegerin(OPG) and osteoclast differentiation factor(ODF) in the bone tissue of patients with hip fracture due to osteoporosis. Methods:OPGmRNA and ODFmRNA in the bone tissue in 50 cases of osteoporosis sufferers(over 50 years old) with hip fracture(Observer Group) and 30 cases of hip facture sufferers with no osteoporosis(Control group) were analyzed with the Semi-Quantitative RT-PCR method. Results:The mRNA expressed of ODF, OPG were both high in the patients with hip fracture. In the control group, the expression of OPG mRNA was observed, while the expression of ODF mRNA was very slight. Conclusion:Aged patients contained all signals including OPG, ODF that are essential for inducing osteoclastogenesis and promoting bone resorption. 相似文献
17.
The clinicopathological and immuohistochemical analysis of solid-pseudopapillary tumor of the pancreas: report of 9 cases 总被引:1,自引:0,他引:1
Shaoqin Chen Shengquan Zou Qibao Dai Peisheng Huang Weihua Cai Hong Li 《南京医科大学学报(自然科学版)》2007,21(6):398-401
Objective:To investigate the clinical features, pathological characteristics and immunophenotype of solid-pseudopapillary tumor of the pancreas(SPTP). Methods:Nine surgically treated cases of SPTP were retrospectively reviewed. Hematoxylin and Eosin(HE) staining and immunohistochemical staining were used to analyze all cases, and the general clinical data was collected. Results:Six patients were asymptomatic except for a palpable mass. Two patients complained of vague-epigastric pain. One patient appeared jaundice. The tumor was encapsulated and solid tissues alternately with cystic tissues. Histologically, the histological structure of solid portion was pseudopapillary with a fibrovascular core. Tumor cells were uniform and medium-sized which were arranged in sheets ets or nests or pseudopapillary patterns. Immunohistochemical studies demonstrated that SPTP proved positive in vimentin(9/9 cases), AAT(9/9 cases), NSE(9/9 cases), ACT(7/9 cases), CK20(2/9 cases), CgA(1/9 cases), S-100(3/gcases), PR(4/gcases), Syn(3/9 cases) and CD56(5/9cases), negative in CEA and ER. Conclusion:SPTP is a tumor predominantly occurring in young women frequently without special symptoms. This tumor has various characteristical histological patterns with different immunophenotype. 相似文献
18.
Scientific principles and rigorous processes should be followed in developing clinical guidelines for therapeutic interventions of integrative medicine
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A clinical guideline for the therapeutic interventions of integrative medicine may be defined as a written document which states a series of recommendations on therapeutic interventions of integrative medicine for a special disease or condition. The guideline may provide assistance to medical professionals in making clinical decisions aimed at improving the clinical outcome of patients and reducing the costs of medical care(~'4~. Recommendations issued by a guideline should be based on the best available evidence in both Western and Chinese medicine. For fulfilling this purpose, the development of clinical guidelines for therapeutic interventions in the field of integrative medicine should follow scientific principles and undergo a rigorous processes. 相似文献
19.
Objective:To probe into the influence of changes of ovarian hormones on the pathogenesis of the specific sub-type premenstrual syndrome(PMS)and reveal partial microcosmic mechanisms of adverse flow of liver-qi.Methods:Estradiol(E2)and progesterone(P)levels in serum were determined at different phases of menstrual cycle by radioimmunoassay.Results:In the group of PMS with adverse flow of liver-qi.the secretive peak value Of E2 and P at the follicular phase significantly decreased,and the secretive peak value at the luteal phase did not come into being.Conclusions:Low E2 and P secretive peak at the follicular phase and absence of secretive peak at the luteal phase is one of the microcosmic mechanisms of PMS with adverse flow of liver-qi.One of the pathophysiologic mechanisms of specific sub-type PMS is probably the continuous low level of E2and P. 相似文献
20.
Real-time three-dimensional echocardiography (RT3DE)is a new ultrasound technique that enables dynamic threedimensional visualization and quantification of the heart in real time. Investigation of feasibility and methodology of RT3DE in determining left ventricular (LV) and right ventricular (RV) volumes, RT3DE was performed in 35 normal adults using Philips SONOS 7500 system with a 2-4 MHz matrix array transducer. The 60°×60° "pyramid" volume database was obtained and analyzed on a TomTec echo workstation. Both LV and RV volumes were calculated with four 3DE methods (i.e. apical 2, 4, 8, and 16-plane) through manually tracing ventricular endocardial borders in end diastole and end systole. Stroke volumes were then calculated. LV volume was also measured by 2DE Simpson's rule using GE VIVID 7 ultrasound machine. 相似文献