Influence of cations during Orange-II degradation on boron-doped diamond electrode

This paper reports a comparative study on the anodic oxidation of 50 mg/L Acid Orange II in the presence of different supporting electrolytes. Experiments have been performed with a batch recirculation reactor containing one-compartment cell equipped with boron-doped diamond anode and Pt cathode. Specifically, the effect of cation is examined among a series of inorganic salts while keeping the anion constant. The results show a significant influence of the applied current density and also of the electrolyte cation on the efficiency of the treatment. In addition, the evidences from electrochemical measurements are used to better clarify the different sequences recorded.     

孪晶对CVD自支撑金刚石薄膜微区织构的影响分析

利用电子背散射衍射技术检测分析了CVD自支撑金刚石薄膜侧面微区织构和孪晶,计算了{100}、{110}、{111}、{122}、{447}、{148}晶面平行薄膜表面的织构在薄膜生长过程中各阶段所占的比例。研究结果表明,不稳定的沉积温度不利于{100}、{110}、{111}织构的形成,孪晶造成了{122}、{447}、{148}织构。     

2000年以来放射增敏剂(化学合成剂和基因治疗剂)概览

IntroductionRadiotherapyhasplayedanimportantroleintreat mentoftumorpatientssinceitappearedabout 80yearsago ,andhasbeenanindispensablepartofthemanage mentofabout 5 0 %oftumors (especially 6 0 % - 70 %ofmalignanttumors) .Currently ,radiotherapyisusedinsimpleandpalliativetherapy ,adjuvanttherapyafterorbeforesurgery ,simultaneousradio chemotherapy ,com binedBRM (biologicalresponsemodifier)therapy ,ets ..Radiosensitizingagentsenhancetheradiationeffectsontumorcellssoastohavebetterresponsesinradioth…     

综合矫治唇裂术后继发鼻唇畸形

目的：探讨通过手术使移位组织解剖复位，综合矫治唇裂术后遗留的鼻、唇畸形。方法：经重建降鼻中隔肌的形态和功能，口轮匝肌的插入缝合，惠侧鼻唇沟瓣梨状孔处充填，鼻小柱的基底离断，鼻翼软骨的解剖学复位、悬吊，完成唇裂鼻唇畸形的修复与功能重建。结果：37例惠者经综合矫治，术后1～3年随访复查，优良31例，改善3例，不满意0。结论：通过综合矫正，一次完成唇、鼻畸形形态、功能及细微的解剖学修复。     

Compatibility of the totally replaced hi

Particulate wear debris in totally replaced hips causes adverse local host reactions. The extreme form of such a reaction, aggressive granulomatosis, was found to be a distinct condition and different from simple aseptic loosening. Reactive and adaptive tissues around the totally replaced hip were made of proliferation of local fibroblast like cells and activated macrophages. Methylmethacrylate and high-molecular-weight polyethylene were shown to be essentially immunologically inert implant materials, but in small particulate form functioned as cellular irritants initiating local biological reactions leading to loosening of the implants. Chromiun-cobalt-molybdenum is the most popular metallic implant material; it is hard and tough, and the bearings of this metal are partially self-polishing. In total hip implants, prerequisites for longevity of the replaced hip are good biocompatibility of the materials and sufficient tribological properties of the bearings. The third key issue is that the bearing must minimize frictional shear at the prosthetic bone-implant interface to be compatible with long-term survival. Some of the approaches to meet these demands are alumina-on-alumina and metal-on-metal designs, as well as the use of highly crosslinked polyethylene for the acetabular component. In order to avoid the wear-based deleterious properties of the conventional total hip prosthesis materials or coatings, the present work included biological and tribological testing of amorphous diamond. Previous experiments had demonstrated that a high adhesion of tetrahedral amorphous carbon coatings to a substrate can be achieved by using mixing layers or interlayers. Amorphous diamond was found to be biologically inert, and simulator testing indicated excellent wear properties for conventional total hip prostheses, in which either the ball or both bearing surfaces were coated with hydrogen-free tetrahedral amorphous diamond films. Simulator testing with such total hip prostheses showed no measurable wear or detectable delamination after 15,000,000 test cycles corresponding to 15 years of clinical use. The present work clearly shows that wear is one of the basic problems with totally replaced hips. Diamond coating of the bearing surfaces appears to be an attractive solution to improve longevity of the totally replaced hip.     

(Pro-)Insulin Biosynthesis and Release of Newly Synthesized (Pro-)Insulin from Isolated Islets of Rat Pancreas in the Presence of Amino Acids and Sulphonylureas+,++

Abstract. The influence of arginine, lysine, tolbutamide and glibenclamide on (pro-)insulin biosynthesis and release of newly synthesized (pro-)insulin was studied in isolated islets of rat pancreas. Islets were incubated with ³H-leucine and glucose in the presence and absence of the test agents. Proinsulin and insulin of islets and incubation media were separated by gel filtration on Sephadex G 50. Estimations were carried out for radioactivity and immunoreactivity for insulin. All four test substances were able to enhance insulin release whereas no stimulation of leucine incorporation into (pro-)insulin was found. Arginine and tolbutamide even markedly reduced (pro-)insulin synthesis. Conversion of proinsulin to insulin was not affected by any of the test agents. For studying the influence of the 4 substances on secretion of newly synthesized (pro-)insulin two experimental models were used: 1) Labelling of the islets in the presence of the test agents, followed by uniform stimulation with glucose alone in the presence or absence of Ca⁺⁺. 2) Addition of the 4 test substances after uniform prelabelling of the islets. 1) Presence of arginine and sulfonylureas during labelling resulted in a significantly enhanced relative fractional release of newly synthesized (pro-)insulin, although the bulk of secreted hormone appeared to stem from the storage pool also under these conditions. The enhanced fractional release was persistent also during the postlabelling period when the islets had been labelled in the presence of arginine or glibenclamide. On the other hand, a decreased release of newly synthesized (pro-)insulin was observed during the postlabelling period in islets labelled in the presence of tolbutamide. Lysine was without significant effects in both periods. Omission of calcium ions during the postlabelling period inhibited the release of both immunoreactive and radioactive hormone. 2) When amino acids or sulphonylureas were added after prelabelling no signifcant changes were found in the specific radioactivity of released (pro-)insulin or in the fractional release of newly synthesized hormone. Enhanced release of fresh granules from the beta cell might explain the increased fractional release of newly synthesized (pro-) insulin when labelling is carried out in the presence of arginine and sulphonylureas, especially glibenclamide.     

Synthesis and Characterization of Multilayered Diamond Coatings for Biomedical Implants

With incredible hardness and excellent wear-resistance, nanocrystalline diamond (NCD) coatings are gaining interest in the biomedical community as articulating surfaces of structural implant devices. The focus of this study was to deposit multilayered diamond coatings of alternating NCD and microcrystalline diamond (MCD) layers on Ti-6Al-4V alloy surfaces using microwave plasma chemical vapor deposition (MPCVD) and validate the multilayer coating's effect on toughness and adhesion. Multilayer samples were designed with varying NCD to MCD thickness ratios and layer numbers. The surface morphology and structural characteristics of the coatings were studied with X-ray diffraction (XRD), Raman spectroscopy, and atomic force microscopy (AFM). Coating adhesion was assessed by Rockwell indentation and progressive load scratch adhesion tests. Multilayered coatings shown to exhibit the greatest adhesion, comparable to single-layered NCD coatings, were the multilayer samples having the lowest average grain sizes and the highest titanium carbide to diamond ratios.     

Upper-limb Postures and Movements during Diamond Polishing

Abstract

Previous occupational health studies of diamond polishers have identified high rates of musculoskeletal disorders of the hands and arms in this population, specifically, ulnar neuropathy in the right elbow. These disorders may be due to the repetitive and forceful motions of the upper extremity required to manipulate the hand-held polishing tools. A video based, biomechanical analysis of the upper extremities of polishers at several diamond-processing factories in Israel was conducted. Detailed motion measurements of the wrists, elbows, and shoulders of polishers were made while. The subjects performed their usual work. During a typical workday, the basic polishing cycle, which involves a series of stereotyped hand and arm movements, is repeated more than 5,000 times. Sustained, extreme flexion of the right elbow, which is the arm holding the eyepiece, may account for the higher rates of ulnar neuropathy in this extremity.     

纳米非晶金刚石膜镀覆镍铬合金烤瓷冠对基牙牙周组织的影响

目的:观察纳米非晶金刚石膜镀覆镍铬合金烤瓷冠对基牙牙周组织的影响。方法:应用镍铬合金烤瓷冠(未镀膜组)修复49例65颗牙,纳米非晶金刚石膜镀覆镍铬合金烤瓷冠(镀膜组)修复46例62颗牙,观察对比1年后两组烤瓷冠的基牙牙周组织变化。结果:镍铬合金烤瓷冠修复1年后,未镀膜组11颗基牙牙龈发生龈染色,镀膜组3颗基牙牙龈发生龈染色;未镀膜组牙龈指数(1.64±0.22)与修复前(0.79±0.16)比较差异有统计学意义,而镀膜组牙龈指数(0.83±0.21)与修复前(0.80±0.19)比较差异无统计学意义;未镀膜组和镀膜组的修复前、修复后菌斑指数、牙周探诊深度差异无统计学意义。结论:镍铬合金烤瓷冠修复对基牙牙周组织有一定的不良影响,纳米非晶金刚石膜镀覆镍铬合金烤瓷冠对基牙牙周组织的影响较小,镀覆纳米非晶金刚石膜能减轻镍铬合金烤瓷冠基牙的牙龈染色及牙龈指数。     

纳米金刚石表面改性对义齿黏附剂黏度的影响

目的:观察不同表面处理的纳米金刚石作为功能填料加入到高分子树脂类义齿黏附剂中,对义齿黏附剂黏度产生的影响。方法:以不同比例配方的改性和非改性纳米金刚石作为功能填料,加入到义齿黏附剂中,测试其黏度。采用SPSS17.0软件包对数据进行统计学分析。结果:添加比例在0.1wt%以下时,义齿黏附剂黏度随着比例的增加而下降;0.1wt%时,黏度降低最显著;添加比例在0.1wt%以上时,义齿黏附剂黏度随着比例的增加而增加。金刚石改性与否对黏度的影响有显著差异。结论:偶联剂化学接枝到金刚石表面,改性后的金刚石在乙醇中的分散稳定性得到提高;适当比例的纳米金刚石能显著降低义齿黏附剂的黏度,增加其流动性;同时,改性纳米金刚石的作用显著高于未经改性的金刚石。