氯离子对两种钴铬合金修复体离子析出行为的影响

目的:研究激光快速成形技术钴铬合金及铸造钴铬合金试件在不同氯离子浓度人工唾液中的离子析出行为。方法:采用激光快速成形技术制备钴铬合金试件24块,并以同种成分的铸造钴铬合金试件作对比,每种试件分为三组,分别浸泡于0.9%、2.0%及3.0%氯化钠浓度的人工唾液中,于第7、14、21、28、35、42、49、56天时检测人工唾液中试件的钴、铬离子析出浓度。结果:同种方法成形的试件,随着氯离子浓度升高,样本中的钴、铬离子析出量也增高,3.0%Na Cl浓度组离子析出量高于2.0%和0.9%Na Cl组,差异有统计学意义(P0.05);氯离子浓度相同的人工唾液中,各时间点的激光快速成形技术钴铬合金离子析出量均低于铸造钴铬合金,在2.0%和3.0%Na Cl浓度时差异有统计学意义(P0.05);随着时间的延长(前4周),2种钴铬合金的离子析出量逐渐增加,差异有统计学意义(P0.05)。结论:激光快速成形技术钴铬合金的抗腐蚀性能优于铸造钴铭合金。     

Volume of RBCs, 24- and 48-hour posttransfusion survivals, and the lifespan of (51)Cr and biotin-X-N-hydroxysuccinimide (NHS)-labeled autologous baboon RBCs: effect of the anticoagulant and blood pH on (51)Cr and biotin-X-NHS elution in vivo

BACKGROUND: The RBC injury that occurs during collection of the first few milliliters of blood into the pH 5.0 ACD (NIH, Formula A) is referred to as the lesion of collection. The RBC injury was evaluated by labeling the ACD RBCs with (51)Cr and measuring the 24-hour posttransfusion survival. The effect of the acidification of ACD blood on the in vivo elution of (51)Cr from the RBC has not been reported. STUDY DESIGN AND METHODS: Baboon blood was collected in heparin and in ACD and CP2D at different ratios of blood to anticoagulant. ACD blood with a pH of 5.7 to 6.9 was labeled with (51)Cr. Heparinized blood with a pH of 7.4 was labeled with biotin-X-N-hydroxysuccinimide (NHS). ACD blood with a pH of 5.9 was labeled with both (51)Cr and biotin-X-NHS. The RBC volumes, 24- and 48-hour posttransfusion survivals, and lifespans (T50) were measured. RESULTS: The RBC volume of ACD blood with a pH ranging from 5.7 to 6.9 was not affected by (51)Cr labeling. (51)Cr-labeled ACD blood with a pH of 6.9 had an RBC volume that was significantly greater than that seen in heparinized blood with a pH of 7.4 labeled with biotin-X-NHS. In vivo elution of (51)Cr from the RBCs prepared from the ACD blood with a pH of 5.7 to 6.9 and in vivo elution of biotin-X-NHS from RBCs prepared from ACD blood with a pH of 5.9 were associated with reductions in 24- and 48-hour posttransfusion survivals and T50. CONCLUSIONS: The anticoagulant and the pH of the medium in which the RBCs were labeled with (51)Cr or biotin-X-NHS affected in vivo elution of the label from the RBCs and may reduce posttransfusion survival values.     

二元镁合金在细胞培养基中的耐腐蚀能力及其生物相容性

背景:尽管已经有很多研究报道镁及其合金具有一定的骨传导性和可降解性,可以做为承重骨科内植物材料,但是还需要做更多的工作来正确评估它的潜力所在。目的:检测镁和二元镁合金在细胞培养基中的降解特性和对成人骨髓间充质干细胞活性的影响。方法:制备纯镁和8种二元镁合金(Mg-Al、Mg-Ca、Mg-Mn、Mg-Sn、Mg-Si、Mg-Y、Mg-Zn、Mg-Zr)样品;采用α-MEM细胞培养基(含体积分数为10%胎牛血清)模拟体内环境下制备标准浸提液,并检测pH值;电感耦合等离子体原子发射光谱仪检测浸提液中镁和添加元素含量;AlamarBlue法检测培养达1,3,5,7d时100%、50%、25%浓度的纯镁和8种镁合金浸提液对成人骨髓间充质干细胞增殖的影响,判断8种二元镁合金的生物相容性。结果与结论:Mg-Ca、Mg-Y合金耐腐蚀性较差,浸提液中Mg2+质量浓度分别达到(408.0±37.9)mg/L和(351±15.3)mg/L,pH值分别为8.87±0.19和8.84±0.15;其次是Mg-Zr合金;其他二元合金耐腐蚀性与纯镁相当。结果表明纯镁和8种二元镁合金100%含量的浸提液均对成人骨髓间充质干细胞的增殖有显著抑制作用,当Mg2+质量浓度低于110mg/L,pH值7.35~7.65时,纯镁和8种二元镁合金对成人骨髓间充质干细胞的增殖无显著影响。     

氮离子溅射对镍铬合金表面细菌黏附的影响

背景：镍铬合金被广泛应用于口腔修复领域,大量实验正在进行其机械性能、抗腐蚀性能以及生物相容性的研究。目的：观察氮离子溅射对镍铬合金表面细菌黏附能力的影响。方法：制作镍铬合金试件 144 件,随机选出 72 件,采氮离子溅射法对其表面改性,镍铬合金组为对照组,氮离子溅射组为实验组。对两组试件表面黏附血型链球菌、黏性放线菌、白色念珠菌,分别进行细菌体外黏附实验。用菌落形成单位计数法统计分析氮离子溅射前后各种细菌黏附量的变化。结果与结论：在细菌黏附 24,48,168 h,上述 3 种细菌在实验组表面黏附量较对照组表面黏附量显著减少（P 〈 0.001）。提示,氮离子溅射可抑制镍铬合金表面细菌黏附。     

二元镁合金在细胞培养基中的耐腐蚀能力及其生物相容性

背景：尽管已经有很多研究报道镁及其合金具有一定的骨传导性和可降解性,可以做为承重骨科内植物材料,但是还需要做更多的工作来正确评估它的潜力所在。目的：检测镁和二元镁合金在细胞培养基中的降解特性和对成人骨髓间充质干细胞活性的影响。方法：制备纯镁和8种二元镁合金（Mg-Al、Mg-Ca、Mg-Mn、Mg-Sn、Mg-Si、Mg-Y、Mg-Zn、Mg-Zr）样品;采用α-MEM细胞培养基（含体积分数为10%胎牛血清）模拟体内环境下制备标准浸提液,并检测pH值;电感耦合等离子体原子发射光谱仪检测浸提液中镁和添加元素含量;AlamarBlue法检测培养达1,3,5,7d时100%、50%、25%浓度的纯镁和8种镁合金浸提液对成人骨髓间充质干细胞增殖的影响,判断8种二元镁合金的生物相容性。结果与结论：Mg-Ca、Mg-Y合金耐腐蚀性较差,浸提液中Mg2＋质量浓度分别达到（408.0±37.9）mg/L和（351±15.3）mg/L,pH值分别为8.87±0.19和8.84±0.15;其次是Mg-Zr合金;其他二元合金耐腐蚀性与纯镁相当。结果表明纯镁和8种二元镁合金100%含量的浸提液均对成人骨髓间充质干细胞的增殖有显著抑制作用,当Mg2＋质量浓度低于110mg/L,pH值7.35~7.65时,纯镁和8种二元镁合金对成人骨髓间充质干细胞的增殖无显著影响。     

氟处理AZ31B生物可降解镁合金材料的细胞相容性

背景:镁及镁合金作为新型可降解植入材料,具有优异的生物相容性和综合力学性能,但是由于镁及镁合金较差的耐蚀性能,影响到其在临床上的应用.表面氟化处理的AZ31B镁合金是否具有良好的生物相容性尚不清楚.目的:以诱导的人骨髓间充质干细胞作为检测细胞,评价不同表面氟处理的镁合金材料的细胞相容性.方法:以诱导的人骨髓间充质干细胞作为检测细胞,取未经氟处理及不同氟处理时间的镁合金材料浸提液进行体外细胞相容性实验,评价不同氟处理的镁合金AZ31B材料的生物相容性.结果与结论:经氟处理镁合金AZ31B材料与未经氟处理镁合金AZ31B材料相比能显著提高细胞存活率,细胞毒性分级1级,对细胞生长基本无毒性作用.提示经氟处理镁合金AZ31B材料生物相容性优于未经氟处理镁合金AZ31B材料.     

反复熔铸对镍铬烤瓷合金化学成分和微观组织结构的影响

背景:熔铸后烤瓷合金能否回收再利用取决于熔铸后烤瓷合金的化学成分、微观组织结构、铸流率、力学性能、金瓷结合性能等因素的变化情况,但目前研究反复熔铸后镍铬烤瓷合金化学成分及微观组织结构的报道较少.目的:分析反复熔铸对镍铬烤瓷合金化学成分、微观组织结构变化的影响.设计、时间及地点:医学材料学体外观察实验,于2007-06/08在福建医科大学附属口腔医院技工室、福州大学材料测试中心进行.材料:以经0～5次熔铸后的镍铬烤瓷合金为原料在真空加压氩气保护铸造机铸造,即获得分别经1～6次熔铸后直径为30.0 mm、厚度为1.0 mm和边长为10.0 mm、厚度为1.0 mm的试样,依次称为Ⅰ～Ⅵ代试样,同时将厂家提供的原始合金加工成相同的形状称为0代试样.方法:应用X射线荧光光谱仪对镍铬烤瓷合金原始合金和反复熔铸后铸成的各代试样进行定性半定量分析.应用正置式反射金相显微镜对经过表面抛光后的镍铬烤瓷合金原始合金和反复熔铸后铸成的各代试样的金相显微结构进行观察;应用X射线粉末衍射仪对镍铬烤瓷合金原始合金和反复熔铸后铸成的各代试样进行物相分析.主要观察指标:各代试件中各化学成分的含量;金相显微镜下观察各代试件有无夹杂物,有无缩松、缩孔等现象;各代试件X射线峰分布情况.结果:在真空加压氩气保护的铸造环境下,经反复熔铸后,镍铬烤瓷合金的主要组分Ni、Cr、Mo、Al、Be等元素所占的质量百分数没有显著性变化,且符合相关标准要求;其金相结构为树枝状共晶结构,随着反复熔铸次数的增加,出现枝晶粗化、枝晶排列稍显紊乱、晶间相(基质)增多现象,且合金内部夹杂物的含量以及缩孔、缩松的数量分布随着反复熔铸次数的增加而逐渐增多、增广;其相结构为镍基固溶体、面心立方(FCC)晶格结构,铬元素广泛分布于镍基质中,经1～6次反复熔铸后的镍铬烤瓷合金的物相结构没有发生变化,未出现新相.结论:在真空加压氩气保护的铸造环境下,镍铬烤瓷合金各主要元素组分的质量百分数和物相结构随着反复熔铸次数的增多没有发生显著变化,随着熔铸次数的增多其枝晶粗化,合金内部夹杂物和铸造缺陷增多.     

烤瓷合金材料生物相容性的研究与进展

背景:研究表明,戴用金属烤瓷冠后,牙龈和牙周出现的局部组织不良反应与口腔烤瓷合金修复体的金属元素释放有关。目的:总结分析非贵金属烤瓷合金及贵金属烤瓷合金的生物相容性、细胞毒性、细胞代谢及其在分子水平的研究机制。方法:检索1990-01/2012-01PubMed数据库,万方数据库与金属烤瓷合金材料对细胞正常生理代谢及细胞免疫学影响的相关研究。英文检索词为"dental casting alloys,biocompatibility,cytotoxicity,cytokines",中文检索词为"烤瓷合金,生物相容性,细胞毒性,细胞因子"。排除因研究目的与本文无关及内容重复的研究,共保留其中的39篇归纳总结。结果与结论:临床5种常用的烤瓷合金的细胞毒性大小依次为:镍铬合金、钛合金、钴铬合金、钯基合金、金合金。贵金属烤瓷合金除了拥有优越的机械性能、抗变色和耐腐蚀性能以及优良的加工应用性还有良好的细胞相容性和生物相容性。金合金的遗传毒性性能优于镍铬合金、钛合金和钴铬合金,是具有良好生物学性能的牙科烤瓷合金材料。非贵金属烤瓷合金中Co-Cr-Mo生物安全性最高,Ni-Cr-Be生物安全性最低,而Ni-Cr介于两者之间。贵金属烤瓷合金的金瓷结合力比非贵金属烤瓷合金的金瓷结合力高,不易出现崩瓷现象。金层可利用自身的弹性屈服来缓解界面应力的破坏从而分散聚集的内应力相应地增强金瓷的结合强度。     

反复熔铸对NEO钴铬烤瓷合金金瓷结合性能的影响

背景:NEO钴铬烤瓷合金不含有害物质,但其钴铬烤瓷合金能否回收利用存在争议,反复熔铸对NEO烤瓷合金性能影响的报道较少。目的:观察反复熔铸对NEO钴铬烤瓷合金金瓷结合力、金相结构、金瓷界面形貌的影响。方法:根据ISO9693标准,采用真空条件下氩气保护加压铸造方法,用三点弯曲实验测试分别经过1～5次熔铸后NEO钴铬烤瓷合金的金瓷结合能力,金相显微镜观察各代铸件金相结构,扫描电镜观察各代试件金瓷结合界面形貌。结果与结论:分别经过1～5次熔铸后的NEO钴铬烤瓷合金的金瓷结合能力差异有显著性意义(P<0.05);随着熔铸次数增加铸件的树枝状结构和晶粒结构逐渐模糊、消失;试件金瓷界面结合逐渐疏松、过渡层厚度增加。提示经过反复熔铸的NEO会明显影响其金瓷结合性能。     

反复熔铸镍铬合金在腐蚀液中的镍离子析出

背景:重复熔铸镍铬烤瓷合金是否会加大镍离子的析出,从而降低抗腐蚀性能,研究结论不一。目的:检测非真空状态下反复熔铸镍铬烤瓷合金在人工唾液中镍离子的析出量,分析熔铸次数对合金抗腐蚀性能的影响。方法:非真空状态下反复熔铸镍铬烤瓷合金Ⅰ、Ⅱ、Ⅲ、Ⅳ代,将试件浸泡于按照ISO标准制定的pH值为6.8,4.0的人工唾液中(168±1)h,恒温(37±1)℃,利用Z-5000原子吸收分光光度计检测不同pH值人工唾液中镍离子的析出量。结果与结论:相同pH值状态下,经两两比较发现,4代Ni-Cr烤瓷合金差异均有显著性意义(P<0.05),铸造第Ⅳ代镍离子析出最多,其次为Ⅲ代、Ⅱ代。随pH值的降低,合金的抗腐蚀性能降低,镍离子析出增多。提示非真空条件下反复熔铸镍铬烤瓷合金的耐腐蚀性能下降,随着熔铸次数的增加,镍离子的析出明显增多。     

Insight into structural stability and helium diffusion behavior of Fe–Cr alloys from first-principles

We have performed the first-principles method to study the structural stability and helium diffusion behavior of Fe–Cr alloys. The calculated bulk modulus of 284.935 GPa in the non-magnetic (NM) state is in good agreement with others. We have obtained solid evidence that the alloy structures meet the mechanical stability criteria and lattice dynamics conditions in the anti-ferromagnetism (AFM) and non-magnetic (NM) states. Compared with bulk γ-Fe, a slightly larger Young''s modulus indicates that the doping of Cr helps to enhance the stiffness of the material and the ability to resist the reversible deformation of shear stress, but the ductility decreased slightly. Our results revealed that the addition of interstitial He atom promotes the expansion and deformation of the lattice, and further enlarges the cell volume. The presence of Cr in the alloy structures promotes the migration of a single helium atom between octahedral interstitials, and at the same time, inhibits the diffusion of helium atoms between tetrahedral interstitials to a large extent, which seem to be trapped in tetrahedral interstitials and cannot escape. The electronic properties show that the alloy materials exhibit obvious metallicity, and the doping of Cr generates an impurity state at lower energy, which is mainly formed by the s, p of Fe and s, p shell electrons of Cr. The charge density difference graphs corroborate that there is bonding interactions between Fe and Cr atoms. Bader charge analysis shows that a stronger polar covalent bond is formed between Fe and Cr in the non-magnetic (NM) state than in the anti-ferromagnetism (AFM) state. Our results provide useful information for understanding the initial growth of helium bubbles in experiments.

We have performed the first-principles method to study the structural stability and helium diffusion behavior of Fe–Cr alloys.     

镁合金材料的溶血率及影响因素

背景:镁合金作为潜在的新型医用可降解生物金属材料受到越来越多的关注,体外纯镁合金浸提液具有溶血作用.目的:探讨镁合金浸提液与其溶血率的关系.方法:将镁合金浸提液稀释,按GBT 16175-2008<医用有机硅材料生物学评价实验方法>第13 部分<溶血试验>的改良方法进行溶血实验.测量A值,计算溶血率,各稀释度溶液钠、镁离子浓度及pH值.结果与结论:100%,50%,25%,10%,5%,2.5%和1%稀释度镁浸提液的溶血率分别为65.3%,66.7%,33.8%,11.8%,6.2%,0.3%和-0.3%.随着稀释度的加大,镁离子浓度呈下降趋势,而钠离子则无明显波动.100%,50%,25%,10%,5%和2.5%稀释度之间的pH值差异无显著性意义(P>0.05),均高于1%稀释度(P<0.05).提示镁合金浸提液的高pH值和离子浓度是影响其体外试验溶血的主要因素.     

Improved paramagnetic liposomes for MRI visualization of pH triggered release

This work aims at assessing the in vitro potential of paramagnetic pH sensitive liposomes as imaging tools for visualizing drug-delivery and release processes by Magnetic Resonance Imaging (MRI). pH sensitive liposomes (pSLs) were formulated using the fusogenic phospholipid 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoethanolamine (POPE), the membrane stabilizer D-α-tocopherol-hemisuccinate (THS), and were loaded with several paramagnetic complexes including the clinically approved Gadoteridol (marketed as ProHance™). The proposed formulation allows the fast and full release of Gadoteridol at pH 5.5. The leakage of the imaging reporter from the vesicles was associated with a relaxivity enhancement that allowed its visualization by MRI. It was observed that the release mechanism implies the protonation of the THS basic sites that leads to vesicle aggregation, thus enabling the expression of the fusogenic property of POPE. Attempts for improving the MRI properties of pSLs were pursued through the encapsulation of imaging agents with higher relaxivity than Gadoteridol, but it was observed that the release kinetic can be significantly affected by the probe size. Aiming at preparing stealth pSLs, PEG chains were conjugated to the external surface of the vesicles via cleavable disulphide bridges. Such nanomedicines do not release their content at acidic pH as long as the coating polymer is not removed from the surface. The results obtained suggest that the liposomal formulation investigated in this work has the potential for visualizing drug-delivery and release processes by in vivo MRI preclinical studies.     

反复熔铸镍铬合金在腐蚀液中的镍离子析出

背景：重复熔铸镍铬烤瓷合金是否会加大镍离子的析出,从而降低抗腐蚀性能,研究结论不一。目的：检测非真空状态下反复熔铸镍铬烤瓷合金在人工唾液中镍离子的析出量,分析熔铸次数对合金抗腐蚀性能的影响。方法：非真空状态下反复熔铸镍铬烤瓷合金Ⅰ、Ⅱ、Ⅲ、Ⅳ代,将试件浸泡于按照ISO标准制定的pH值为6.8,4.0的人工唾液中（168±1）h,恒温（37±1）℃,利用Z-5000原子吸收分光光度计检测不同pH值人工唾液中镍离子的析出量。结果与结论：相同pH值状态下,经两两比较发现,4代Ni-Cr烤瓷合金差异均有显著性意义（P〈0.05）,铸造第Ⅳ代镍离子析出最多,其次为Ⅲ代、Ⅱ代。随pH值的降低,合金的抗腐蚀性能降低,镍离子析出增多。提示非真空条件下反复熔铸镍铬烤瓷合金的耐腐蚀性能下降,随着熔铸次数的增加,镍离子的析出明显增多。     

Bioadhesive grafted starch copolymers as platforms for peroral drug delivery: a study of theophylline release.

Nonirritant bioadhesive drug release systems based on starch-acrylic acid graft copolymers prepared by radiation of starch and acrylic acid mixtures with (60)Co were developed for buccal application. The release rate of theophylline (TPL), used as a model drug, depended on the ratio of starch to acrylic acid and on the presence of cations in the graft copolymers, but was practically not affected by the pH (between pH 3 and 7) of the dissolution medium nor by the type of starch used (corn, rice, or potato). Possible release mechanisms are discussed for specific conditions. In general, the release behavior of the graft copolymers was found to be non-Fickian, n value being between 0.6 and 0.96, suggesting that the release was controlled by a combination of tablet erosion and the diffusion of the drug from the swollen matrix. Incorporation of divalent cations into the graft copolymers led to a significant decrease in swelling erosion of the tablets as well as a substantial retardation of drug release. Highest work of adhesion was obtained with graft copolymers containing calcium ions as well as longer time of adhesion on dogs' gingiva.     

In vitro and in vivo activity of murine lymphokine-activated killer cells after cryopreservation

The in vitro and in vivo effects of cryopreservation on the cytotoxic activity of murine lymphokine-activated killer (LAK) cells were studied. LAK cells were generated by incubation of spleen lymphocytes of BALB/c mice for 3 days with recombinant interleukin-2 (rIL-2) and subsequent cryopreservation. Cytotoxicity was determined in a 51Cr release assay. After thawing, cytotoxic activity was reduced (40.4% 51Cr release at an effector:target cell ratio of 40:1 as compared to 68.5% 51Cr release before freezing) and could be restored to precryopreserved levels by reincubation with rIL-2 for 2 days after thawing (78.8% 51Cr release). These cells were then tested in BALB/c mice injected with RAW 112 cells, a pre-B-cell lymphoma line. The results demonstrate that the survival rate of mice injected with cryopreserved and restimulated LAK cells (50% survival greater than 180 days after injection) did not differ significantly from that of mice injected with fresh unfrozen LAK cells (60% survival greater than 120 days, 50% survival greater than 180 days). Cryopreserved LAK cells have potential use in adoptive immunotherapy.     

The stabilizing effect of glucocorticoids on human endothelial cells in culture

The effect of hydrocortisone, prednisolone and dexamethasone on the stability and viability of cultured human endothelial cells was studied by measuring the release of 51Cr from pre-labelled cells by cell number calculation and by the Trypan-blue test. All glucocorticoids studied, stabilized endothelial cells as demonstrated by a decreased release of 51Cr. The maximal stabilizing effect of the steroids appeared to be equal, although the maximal effect of dexamethasone was seen at a lower concentration than that of prednisolone and hydrocortisone. However, at the very high concentration of 10(-4) mol/l, dexamethasone induced an increase in the release of 51Cr suggesting a toxic effect. The viability of cells was not affected by the steroids. The stabilizing effect of glucocorticoids at optimal concentrations in vitro may indicate strengthening of endothelial integrity by the steroids in vivo. This may explain their beneficial effect in the treatment of certain vascular disorders, e.g. thrombocytopenia.     

镁锌合金与大鼠肠道的生物相容性

背景:镁合金在骨科已进行一些初步研究,有较好的生物相容性,目前尚未在肠道进行相关基础研究.目的:镁锌合金植入大鼠盲肠,观察其与大鼠的生物相容性.方法:取SD大鼠随机区组法分为镁合金组、纯钛组和假手术组,镁合金组在盲肠切口周围包埋长约5 mm×1 mm×1 mm镁锌合金条,纯钛组植入相同尺寸的医用纯钛条,假手术组仅做缝合.于术前、术后第7,14,21,28天,观察血清谷草转氨酶、肌酐、镁离子浓度;植入材料区X射线片;肝、肾和材料植入区盲肠病理学变化.结果与结论:各组同一时间节点血清谷草转氨酶、肌酐、镁离子浓度的差异无显著性意义(P>0.05);镁锌合金逐步降解,28 d时部分降解;肝肾盲肠病理无明显异常.结果提示,镁锌合金对肠道无明显影响,其降解时间发挥固定功能时间长于肠道愈合时间,且有较好的生物相容性,可用作胃肠吻合器所用到的吻合钉.     

氮离子溅射对镍铬合金表面细菌黏附的影响

背景:镍铬合金被广泛应用于口腔修复领域,大量实验正在进行其机械性能、抗腐蚀性能以及生物相容性的研究.目的:观察氮离子溅射对镍铬合金表面细菌黏附能力的影响.方法:制作镍铬合金试件144件,随机选出72件,采氮离子溅射法对其表面改性,镍铬合金组为对照组,氮离子溅射组为实验组.对两组试件表面黏附血型链球菌、黏性放线菌、白色念珠菌,分别进行细菌体外黏附实验.用菌落形成单位计数法统计分析氮离子溅射前后各种细菌黏附量的变化.结果与结论:在细菌黏附24,48,168 h,上述3种细菌在实验组表面黏附量较对照组表面黏附量显著减少(P < 0.001).提示,氮离子溅射可抑制镍铬合金表面细菌黏附.     

Antioxidant Effects and Insulin Resistance Improvement of Chromium Combined with Vitamin C and E Supplementation for Type 2 Diabetes Mellitus

To determine the effects of combined supplementation with chromium (Cr) and vitamins C and E on oxidative stress in type 2 diabetes, adult subjects with HbA1c >8.5%. Subjects (n = 30) in this randomized, double blind, placebo-control study were divided into three groups (placebo, Cr or Cr + C + E) on daily treatment. The Cr group received 1000 µg of Cr (as Cr yeast); the Cr + C + E group received Cr (1000 µg as Cr yeast) together with vitamins C (1000 mg) and E (800 IU); and, a control group received a placebo. Baseline plasma Cr levels were not significant differences comparing the supplementation and placebo groups. Thiobarbituric acid reactive substances (TBARS) and total antioxidative status (TAS) were also not significant different. Following the 6-month study period, the plasma TBARS levels, fasting glucose, HbA1c and insulin resistance were significantly decreased in the Cr and Cr + C + E groups, but not for the placebo group. Plasma TAS and glutathione peroxidase were significantly higher for Cr and Cr + C + E groups relative to the placebo group. These findings suggest that Cr supplementation alone and combined of Cr together with vitamins C and E was effective for minimization of oxidative stress and improvement of glucose metabolism in type 2 DM patients.