BACKGROUND & AIMS: :Titanium and its alloys are widely used as implant materials for dental and orthopaedic applications. To improve their wear and corrosion resistance, several surface modifications that give rise to an outer ceramic layer of rutile have been developed. It is expected that after a long period of functional loading, rutile debris will arise from these modified surfaces. We have compared the in vitro biocompatibility of subcytotoxic doses of rutile and titanium particles of phagocytosable size in primary cultures of human osteoblasts. Particles were visualized using a spectral confocal microscope by reflection. Both types of particles aggregated in the culture media and were efficiently internalized by osteoblasts as agglomerates. Treatment of isolated cultures of osteoblasts with rutile particles stimulated the release of IL-6, PGE2, and GM-CSF to a lesser extent than titanium. The influence of macrophages on the particle-induced stimulation of those local factors was analyzed by coculturing TPA-differentiated THP-1 cells with osteoblasts. Under these conditions, levels of IL-6 and PGE2 after treatment of cocultured osteoblasts with rutile particles were lower than after exposure to titanium. These results indicate that rutile debris shows a lower bioreactivity than titanium when tested in cultures of human osteoblasts and support the improved biocompatibility of titanium-based implants modified to create an outer layer of rutile on their surfaces.

背景与目标： : 钛及其合金被广泛用作牙科和骨科应用的植入材料。为了提高它们的耐磨性和耐腐蚀性，已经开发了几种表面改性，这些表面改性会产生金红石的外部陶瓷层。预计经过长时间的功能加载后，这些改性表面会产生金红石碎屑。我们已经比较了人成骨细胞原代培养物中亚细胞毒性剂量的金红石和可吞噬大小的钛颗粒的体外生物相容性。使用光谱共聚焦显微镜通过反射使颗粒可视化。两种类型的颗粒都聚集在培养基中，并被成骨细胞有效地内化为团聚体。用金红石颗粒处理分离的成骨细胞培养物刺激IL-6，PGE2和gm-csf的释放程度低于钛。通过将TPA分化的THP-1细胞与成骨细胞共培养来分析巨噬细胞对颗粒诱导的刺激这些局部因素的影响。在这些条件下，用金红石颗粒处理共培养的成骨细胞后的IL-6和PGE2水平低于暴露于钛后的水平。这些结果表明，当在人成骨细胞培养物中进行测试时，金红石碎片显示出比钛更低的生物活性，并支持改进的基于钛的植入物的生物相容性，该植入物经过改性以在其表面形成金红石外层。

BACKGROUND & AIMS: :As titanium dioxide (TiO(2)) nanoparticles are widely used commercially, their potential biosafety and metabolic mechanism needs to be fully explained. In this study, the cytotoxicity of homogeneous and weakly aggregated (< 100 nm) TiO(2) nanoparticles was investigated by analyzing the changes in metabolite profiles both in mouse fibroblast (L929) cells and their corresponding culture media using gas chromatograph with a time-of-flight mass spectrometry (GC/TOFMS)-based metabolomic strategy. With multivariate statistics analysis, satisfactory separations were observed in principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA) models. Based on the variable importance in the OPLS-DA models, a series of differential metabolites were identified by comparison between TiO(2) nanoparticle-treated L929 cells or their corresponding culture media and the control groups. It was found that the major biochemical metabolism (carbohydrate metabolism) was suppressed in TiO(2) nanoparticle-treated L929 cells and their corresponding culture media. These results might account for the serious damage to energy metabolism in mitochondria and the increased cellular oxidation stress in TiO(2) nanoparticle-induced L929 cells. These results also suggest that the metabolomic strategy had a great potential in evaluating the cytotoxicity of TiO(2) nanoparticles and thus was very helpful in understanding its underlying molecular mechanisms.

背景与目标： : 由于二氧化钛 (TiO(2)) 纳米颗粒在商业上被广泛使用，因此需要充分解释其潜在的生物安全性和代谢机理。在这项研究中，通过使用气相色谱仪分析小鼠成纤维细胞 (L929) 细胞及其相应培养基中代谢物谱的变化，研究了均质和弱聚集 (< 100  nm) TiO(2) 纳米颗粒的细胞毒性飞行时间质谱 (GC/TOFMS) 基于代谢组学策略。通过多元统计分析，在主成分分析 (PCA) 和正交偏最小二乘判别分析 (OPLS-DA) 模型中观察到令人满意的分离。基于OPLS-DA模型中的可变重要性，通过将TiO(2) 纳米颗粒处理的L929细胞或其相应的培养基与对照组进行比较，鉴定出一系列差异代谢物。发现在TiO(2) 纳米颗粒处理的L929细胞及其相应的培养基中，主要的生化代谢 (碳水化合物代谢) 受到抑制。这些结果可能解释了线粒体能量代谢的严重损害以及TiO(2) 纳米颗粒诱导的L929细胞中细胞氧化应激的增加。这些结果还表明，代谢组学策略在评估TiO(2) 纳米颗粒的细胞毒性方面具有巨大潜力，因此对理解其潜在的分子机制非常有帮助。

BACKGROUND & AIMS: :Silicon dioxide (silica, SiO2, SAS) and titanium dioxide (TiO2) are produced in high volumes and applied in many consumer and food products. As a consequence, there is a potential human exposure and subsequent systemic uptake of these particles. In this study we show the characterization and quantification of both total silicon (Si) and titanium (Ti), and particulate SiO2 and TiO2 in postmortem tissue samples from 15 deceased persons. Included tissues are liver, spleen, kidney and the intestinal tissues jejunum and ileum. Low-level analysis was enabled by the use of fully validated sample digestion methods combined with (single particle) inductively coupled plasma high resolution mass spectrometry techniques (spICP-HRMS). The results show a total-Si concentration ranging from <2 to 191 mg Si/kg (median values of 5.8 (liver), 9.5 (spleen), 7.7 (kidney), 6.8 (jejunum), 7.6 (ileum) mg Si/kg) while the particulate SiO2 ranged from <0.2 to 25 mg Si/kg (median values of 0.4 (liver), 1.0 (spleen), 0.4 (kidney), 0.7 (jejunum, 0.6 (ileum) mg Si/kg), explaining about 10% of the total-Si concentration. Particle sizes ranged from 150 to 850 nm with a mode of 270 nm. For total-Ti the results show concentrations ranging from <0.01 to 2.0 mg Ti/kg (median values of 0.02 (liver), 0.04 (spleen), 0.05 (kidney), 0.13 (jejunum), 0.26 (ileum) mg Ti/kg) while particulate TiO2 concentrations ranged from 0.01 to 1.8 mg Ti/kg (median values of 0.02 (liver), 0.02 (spleen), 0.03 (kidney), 0.08 (jejunum), 0.25 (ileum) mg Ti/kg). In general, the particulate TiO2 explained 80% of the total-Ti concentration. This indicates that most Ti in these organ tissues is particulate material. The detected particles comprise primary particles, aggregates and agglomerates, and were in the range of 50-500 nm with a mode in the range of 100-160 nm. About 17% of the detected TiO2 particles had a size <100 nm. The presence of SiO2 and TiO2 particles in liver tissue was confirmed by scanning electron microscopy with energy dispersive X-ray spectrometry.

背景与目标： : 二氧化硅 (二氧化硅，SiO2，SAS) 和二氧化钛 (TiO2) 的产量很高，并应用于许多消费品和食品中。因此，存在潜在的人类暴露和随后对这些颗粒的全身吸收。在这项研究中，我们展示了来自15名死者的死后组织样品中总硅 (Si) 和钛 (Ti) 以及颗粒SiO2和TiO2的表征和定量。包括肝，脾，肾和肠组织空肠和回肠。通过使用经过充分验证的样品消化方法结合 (单颗粒) 电感耦合等离子体高分辨率质谱技术 (spicp-hrms)，可以进行低水平分析。结果显示，总Si浓度范围为 <2至191  mg Si/kg (5.8 (肝脏)，9.5 (脾脏)，7.7 (肾脏)，6.8 (空肠)，7.6 (回肠) mg Si/kg)，而颗粒SiO2的范围为 <0.2至25  mg Si/kg (0.4 (肝)，1.0 (脾)，0.4 (肾)，0.7 (空肠，0.6 (回肠) mg Si/kg的中值)，解释总Si浓度的约10%。粒径范围为150至850  nm，模式为270  nm。对于总Ti，结果显示浓度范围为 <0.01至2.0  mg Ti/kg (0.02 (肝脏)，0.04 (脾脏)，0.05 (肾)，0.13 (空肠)，0.26 (回肠) mg Ti/kg)，而颗粒TiO2浓度范围为0.01至1.8  mg Ti/kg (0.02 (肝)，0.02 (脾)，0.03 (肾)，0.08 (空肠)，0.25 (回肠) mg Ti/kg)。一般来说，颗粒TiO2解释了总Ti浓度的80%。这表明这些器官组织中的大多数Ti是颗粒材料。检测到的颗粒包括初级颗粒、聚集体和团聚体，在50-500  nm范围内，模式在100-160  nm范围内。大约17% 的检测到的TiO2颗粒的尺寸 <100 nm nm。通过扫描电子显微镜和能量色散x射线光谱法证实了肝组织中SiO2和TiO2颗粒的存在。

BACKGROUND & AIMS: :Titanium implants are the standard therapeutic option when restoring missing teeth and reconstructing fractured and/or diseased bone. However, in the 30 years since the advent of micro-rough surfaces, titanium's ability to integrate with bone has not improved significantly. We developed a method to create a unique titanium surface with distinct roughness features at meso-, micro-, and nano-scales. We sought to determine the biological ability of the surface and optimize it for better osseointegration. Commercially pure titanium was acid-etched with sulfuric acid at different temperatures (120, 130, 140, and 150 °C). Although only the typical micro-scale compartmental structure was formed during acid-etching at 120 and 130 °C, meso-scale spikes (20-50 μm wide) and nano-scale polymorphic structures as well as micro-scale compartmental structures formed exclusively at 140 and 150 °C. The average surface roughness (Ra) of the three-scale rough surface was 6-12 times greater than that with micro-roughness only, and did not compromise the initial attachment and spreading of osteoblasts despite its considerably increased surface roughness. The new surface promoted osteoblast differentiation and in vivo osseointegration significantly; regression analysis between osteoconductivity and surface variables revealed these effects were highly correlated with the size and density of meso-scale spikes. The overall strength of osseointegration was the greatest when the acid-etching was performed at 140 °C. Thus, we demonstrated that our meso-, micro-, and nano-scale rough titanium surface generates substantially increased osteoconductive and osseointegrative ability over the well-established micro-rough titanium surface. This novel surface is expected to be utilized in dental and various types of orthopedic surgical implants, as well as titanium-based bone engineering scaffolds.

背景与目标： : 钛植入物是修复缺失牙齿和重建骨折和/或患病骨时的标准治疗选择。但是，自微粗糙表面出现以来的30年中，钛与骨骼整合的能力并未显着提高。我们开发了一种方法来创建独特的钛表面，该钛表面在细观，微观和纳米级具有明显的粗糙度特征。我们试图确定表面的生物学能力，并对其进行优化以实现更好的骨整合。商业纯钛在不同温度 (120、130、140和150 °C) 下用硫酸酸蚀。尽管在120和130 °C的酸蚀刻期间仅形成典型的微尺度隔室结构，但仅在140和150 °C形成的中尺度尖峰 (20-50μm宽) 和纳米级多晶型结构以及微尺度隔室结构。三尺度粗糙表面的平均表面粗糙度 (Ra) 是仅具有微粗糙度的表面粗糙度的6-12倍，尽管其表面粗糙度显着增加，但并未损害成骨细胞的初始附着和扩散。新表面显着促进了成骨细胞的分化和体内骨整合; 骨传导性和表面变量之间的回归分析表明，这些作用与中尺度尖峰的大小和密度高度相关。当在140 °C下进行酸蚀刻时，骨整合的整体强度最大。因此，我们证明了我们的中，微米和纳米级的粗糙钛表面在成熟的微粗糙钛表面上产生了显着增强的骨传导性和骨整合能力。这种新颖的表面有望用于牙科和各种类型的骨科手术植入物以及基于钛的骨工程支架。

BACKGROUND & AIMS: :The purpose of the current study was to assess the outcome of antegrade intramedullary fixation with titanium elastic nail (TEN) in displaced fifth metacarpal neck fractures. The present study included 69 consecutive juvenile patients with displaced fifth metacarpal fractures. The head-shaft angle of the fifth metacarpal and range of motion (ROM) of the metacarpophalangeal (MCP) joint were evaluated. A disabilities of the arm, shoulder and hand (DASH) questionnaire was used to assess upper arm function. The head-shaft angle of the affected side was significantly improved postoperatively (P<0.05). No marked difference was observed between the affected and unaffected side in head-shaft angle and ROM. The average DASH score was 1.7 (range, 0-6.0). All patients obtained anatomical reduction postoperatively and the average healing time was 5.7±1.09 weeks (range, 5-10 weeks) with no non-union cases. Therefore antegrade intramedullary fixation with TEN is recommended as an easy, reliable and minimally invasive surgical technique for treating displaced fifth metacarpal neck fractures.

背景与目标： : 本研究的目的是评估在移位的第五掌骨颈骨折中使用钛弹性钉 (TEN) 进行顺行髓内固定的结果。本研究包括69名连续的第五掌骨骨折移位的少年患者。评估了第五掌骨的头轴角度和掌骨 (MCP) 关节的运动范围 (ROM)。手臂，肩膀和手部残疾 (DASH) 问卷用于评估上臂功能。术后患侧的头轴角度明显改善 (P<0.05)。在头轴角和ROM的受影响侧和未受影响侧之间未观察到明显差异。平均DASH评分为1.7 (范围，0-6.0)。所有患者术后均获得解剖复位，平均愈合时间为5.7 ± 1.09周 (范围5-10周)，无不愈合病例。因此，建议使用TEN进行顺行髓内固定作为一种简便，可靠且微创的手术技术，以治疗移位的第五掌骨颈骨折。

BACKGROUND & AIMS: :With lithium-ion (li-ion) batteries as energy storage devices, operational safety from thermal runaway remains a major obstacle especially for applications in harsh environments such as in the oil industry. In this approach, a facile method via microwave irradiation technique (MWI) was followed to prepare Co3O4/reduced graphene oxide (RGO)/hexagonal boron nitride (h-BN) nanocomposites as anodes for high temperature li-ion batteries. Results showed that the addition of h-BN not only enhanced the thermal stability of Co3O4/RGO nanocomposites but also enhanced the specific surface area. Co3O4/RGO/h-BN nanocomposites displayed the highest specific surface area of 191 m2/g evidencing the synergistic effects between RGO and h-BN. Moreover, Co3O4/RGO/h-BN also displayed the highest specific capacity with stable reversibility on the high performance after 100 cycles and lower internal resistance. Interestingly, this novel nanocomposite exhibits outstanding high temperature performances with excellent cycling stability (100% capacity retention) and a decreased internal resistance at 150 °C.

背景与目标： : 使用锂离子 (li-ion) 电池作为储能设备，热失控的操作安全性仍然是主要障碍，尤其是在恶劣环境 (例如石油行业) 中的应用。在这种方法中，采用了一种通过微波辐射技术 (MWI) 的简便方法来制备Co3O4/还原的氧化石墨烯 (RGO)/六方氮化硼 (h-BN) 纳米复合材料，作为高温锂离子电池的阳极。结果表明，h-BN的加入不仅提高了Co3O4/RGO纳米复合材料的热稳定性，而且提高了比表面积。Co3O4/RGO/h-BN纳米复合材料显示出最高的比表面积，为191   m2/g，表明RGO和h-BN之间具有协同作用。此外，Co3O4/RGO/h-BN还显示出最高比容量，在100循环后的高性能上具有稳定的可逆性和较低的内阻。有趣的是，这种新型纳米复合材料表现出出色的高温性能，具有优异的循环稳定性 (100% 容量保持) 和在150 ℃ 下降低的内阻。

BACKGROUND & AIMS: :Bovine serum albumin (BSA) was employed as a model protein to study its loading efficiency into a calcium phosphate (CaP) coating on titanium substrates. It is found that the protein loading efficiency can be adjusted by varying the specific configurations of the coating system such as simulated body fluid (SBF) volume, solution height and container selection for the SBF. A BSA loading efficiency as high as 90% was achieved when the ratio of the substrate surface area to modified SBF (m-SBF) volume was as high as 0.072. The release of BSA from the biomimetic coatings was also investigated in vitro. A sustained release was achieved although a large quantity of BSA was still trapped in the coating after 15 days of immersion in a phosphate buffer solution. A much faster release rate would be expected when the coating is implanted in vivo due to the active involvement of osteoclast cells and enzymes.

背景与目标： : 牛血清白蛋白 (BSA) 被用作模型蛋白，以研究其在钛底物上的磷酸钙 (CaP) 涂层中的负载效率。发现可以通过改变涂层系统的特定配置 (例如模拟体液 (SBF) 体积，溶液高度和SBF的容器选择) 来调节蛋白质的加载效率。当衬底表面积与改性SBF (m-SBF) 体积之比高达90% 时，获得高达0.072的BSA加载效率。还在体外研究了仿生涂层中BSA的释放。尽管在磷酸盐缓冲溶液中浸泡15天后仍将大量BSA捕获在涂层中，但仍实现了持续释放。由于破骨细胞和酶的活性参与，当将涂层植入体内时，预计释放速度会更快。

BACKGROUND & AIMS: :Carbide layer was formed on the surface of Ti by heating in hydrocarbon atmosphere (benzene C6H6) at 1000-1400 degrees C using a high frequency induction heating method. Physical and mechanical properties of carbide-coated Ti were investigated to examine its potential as an abrasion-resistant implant material. Scanning electron microscopy (SEM) showed that the surface of Ti was covered with fine grains of 1-4 microm diameter, depending on heating conditions. In addition, carbide layer of about 1-25 microm thickness was observed on the cross-section of specimens by SEM and energy dispersive spectroscopy. Vickers hardness of surface carbide was found to be more than 2000. Further, Martens scratch test and ultrasonic scaler abrasion test showed that the indentation depth and width of carbide-coated Ti were much smaller than pure Ti, thereby confirming its high abrasion resistance. These results showed that for Ti implant materials that require high abrasion resistance, such as the abutment for dental implants, surface carbide coatings would be an effective means to improve their wear properties.

背景与目标： : 通过在烃气氛 (苯C6H6) 中使用高频感应加热方法在1000-1400 ℃ 加热，在Ti的表面上形成碳化物层。研究了碳化物涂层Ti的物理和机械性能，以检查其作为耐磨植入物材料的潜力。扫描电子显微镜 (SEM) 显示，根据加热条件，Ti的表面覆盖着直径为1-4微米的细晶粒。此外，通过SEM和能量色散光谱法在样品的横截面上观察到约1-25微米厚度的碳化物层。发现表面碳化物的维氏硬度大于2000。此外，Martens划痕试验和超声洁牙机磨损试验表明，碳化物涂层Ti的压痕深度和宽度远小于纯Ti，从而证实了其高耐磨性。这些结果表明，对于需要高耐磨性的Ti植入物材料，例如牙科植入物的基台，表面碳化物涂层将是改善其磨损性能的有效手段。

BACKGROUND & AIMS: :Decrease in processing speed due to increased resistance and capacitance delay is a major obstacle for the down-scaling of electronics1-3. Minimizing the dimensions of interconnects (metal wires that connect different electronic components on a chip) is crucial for the miniaturization of devices. Interconnects are isolated from each other by non-conducting (dielectric) layers. So far, research has mostly focused on decreasing the resistance of scaled interconnects because integration of dielectrics using low-temperature deposition processes compatible with complementary metal-oxide-semiconductors is technically challenging. Interconnect isolation materials must have low relative dielectric constants (κ values), serve as diffusion barriers against the migration of metal into semiconductors, and be thermally, chemically and mechanically stable. Specifically, the International Roadmap for Devices and Systems recommends4 the development of dielectrics with κ values of less than 2 by 2028. Existing low-κ materials (such as silicon oxide derivatives, organic compounds and aerogels) have κ values greater than 2 and poor thermo-mechanical properties5. Here we report three-nanometre-thick amorphous boron nitride films with ultralow κ values of 1.78 and 1.16 (close to that of air, κ = 1) at operation frequencies of 100 kilohertz and 1 megahertz, respectively. The films are mechanically and electrically robust, with a breakdown strength of 7.3 megavolts per centimetre, which exceeds requirements. Cross-sectional imaging reveals that amorphous boron nitride prevents the diffusion of cobalt atoms into silicon under very harsh conditions, in contrast to reference barriers. Our results demonstrate that amorphous boron nitride has excellent low-κ dielectric characteristics for high-performance electronics.

背景与目标： : 由于电阻和电容延迟增加而导致的处理速度降低是electronics1-3缩小的主要障碍。最小化互连 (连接芯片上不同电子组件的金属线) 的尺寸对于设备的小型化至关重要。互连通过非导电 (电介质) 层彼此隔离。到目前为止，研究主要集中在降低定标互连的电阻上，因为使用与互补金属氧化物半导体兼容的低温沉积工艺集成电介质在技术上具有挑战性。互连隔离材料必须具有较低的相对介电常数 (κ 值)，充当防止金属迁移到半导体中的扩散势垒，并且在热，化学和机械上是稳定的。具体来说，《国际设备和系统路线图》建议4开发 κ 值小于2 2028年的电介质。现有的低 κ 材料 (例如氧化硅衍生物，有机化合物和气凝胶) 的 κ 值大于2，并且热机械性能差5。在这里，我们报告了在工作频率分别为100千赫兹和1兆赫兹时具有1.78和1.16的超低 κ 值 (接近空气，κ = 1) 的三纳米厚非晶氮化硼膜。该膜在机械和电方面是坚固的，击穿强度为每厘米7.3兆伏，这超出了要求。横截面成像显示，与参考势垒相反，在非常苛刻的条件下，非晶态氮化硼阻止钴原子扩散到硅中。我们的结果表明，非晶态氮化硼具有出色的低 κ 介电特性，可用于高性能电子设备。

BACKGROUND & AIMS: OBJECTIVE:Nickel-titanium orthodontic wires have various temperature-dependent phases. The purpose of this study was to investigate temperature-dependent corrosion characteristics of shape memory, superelastic, and nonsuperelastic orthodontic wires. METHODS:Four orthodontic wires were investigated: 27 and 40 degrees C copper Ni-Ti (superelastic and shape memory, respectively), superelastic Ni-Ti, and nonsuperelastic Nitinol Classic. Differential scanning calorimetry (DSC) was used to confirm phase/temperature behavior of the wires. Sectioned halves of as-received archwires were assessed electrochemically in artificial saliva at 5, 24, 37, and 45 degrees C. Open circuit potential (OCP) was monitored for 2h followed by polarization resistance and cyclic polarization tests. RESULTS:DSC results showed Nitinol was primarily martensitic-stable whereas NiTi, 27 degrees C CuNiTi, and 40 degrees C CuNiTi possessed austenite-finish temperatures of approximately 19, 21, and 38 degrees C. The OCP of the CuNiTi wires was significantly greater than NiTi and Nitinol but no apparent trend in values was apparent with regard to temperature or phases present. Corrosion current density (i(corr)) increased with temperature for all wires, but not all were equally influenced. The two lowest austenite-finish temperature wires (27 degrees C CuNiTi and NiTi) approximately tripled in i(corr) from 37 to 45 degrees C. Greater incidence of pitting was observed in the CuNiTi wires. SIGNIFICANCE:This study showed the corrosion rate of various nickel-titanium wires increase with temperature and different phases present may influence corrosion rate trends.

背景与目标：

BACKGROUND & AIMS: :Gold nanoparticles (Au NPs), silver nanoparticles (Ag NPs), zinc oxide nanoparticles (ZnO NPs) and titanium dioxide nanoparticles (TiO2 NPs) are widely used in cosmetic products such as preservatives, colorants and sunscreens. This study investigated the genotoxicity of Au NPs, Ag NPs, ZnO NPs and TiO2 NPs using the SOS chromotest with Escherichia coli PQ37. The maximum exposure concentrations for each nanoparticle were 3.23 mg l(-1) for Au NPs, 32.3 mg l(-1) for Ag NPs and 100 mg l(-1) for ZnO NPs and TiO2 NPs. Additionally, in order to compare the genotoxicity of nanoparticles and corresponding dissolved ions, the ions were assessed in the same way as nanoparticles. The genotoxicity of the titanium ion was not assessed because of the extremely low solubility of TiO2 NPs. Au NPs, Ag NPs, ZnO NPs, TiO2 NPs and ions of Au, Ag and Zn, in a range of tested concentrations, exerted no effects in the SOS chromotest, evidenced by maximum IF (IFmax) values of below 1.5 for all chemicals. Owing to the results, nanosized Au NPs, Ag NPs, ZnO NPs, TiO2 NPs and ions of Au, Ag and Zn are classified as non-genotoxic on the basis of the SOS chromotest used in this study. To the best of our knowledge, this is the first study to evaluate the genotoxicity of Au NPs, Ag NPs, ZnO NPs and TiO2 NPs using the SOS chromotest.

背景与目标： 金纳米粒子 (Au NPs) 、银纳米粒子 (Ag NPs) 、氧化锌纳米粒子 (ZnO NPs) 和二氧化钛纳米粒子 (TiO2 NPs) 广泛用于化妆品，如防腐剂、着色剂和防晒霜。本研究使用大肠杆菌pq37的SOS色测法研究了Au NPs，Ag NPs，ZnO NPs和TiO2 NPs的遗传毒性。对于Au NPs，每种纳米颗粒的最大暴露浓度为3.23  mg  l(-1)，对于Ag NPs为32.3  mg  l(-1)，对于ZnO NPs和TiO2 NPs为100  mg  l(-1)。此外，为了比较纳米颗粒和相应溶解离子的遗传毒性，以与纳米颗粒相同的方式评估离子。由于TiO2 NPs的溶解度极低，因此未评估钛离子的遗传毒性。在测试浓度范围内的Au NPs、Ag NPs、ZnO NPs、tio2nps和Au、Ag和Zn的离子在SOS色度测试中没有影响，所有化学品的最大IF (IFmax) 值低于1.5证明。根据结果，根据本研究中使用的SOS色度，将纳米级的Au NPs，Ag NPs，ZnO NPs，TiO2 NPs以及Au，Ag和Zn的离子分类为非遗传毒性。据我们所知，这是第一项使用SOS色度测试评估Au NPs，Ag NPs，ZnO NPs和TiO2 NPs的遗传毒性的研究。

BACKGROUND & AIMS: OBJECTIVE:To compare the results of ossicular chain reconstruction using hydroxyapatite (HA) and titanium (TI) prostheses. STUDY DESIGN:Retrospective study and case series. SETTING:Tertiary referral center. PATIENTS:One hundred sixty-eight patients presenting chronic otitis media with or without cholesteatoma. INTERVENTION:Ossiculoplasty using partial or total HA and TI ossicular replacement prostheses (TORP and PORP, respectively). MAIN OUTCOME MEASURES:Patients were assessed at 2 months postoperatively to establish short-term results. Results of treatment for conductive hearing loss were reported according to guidelines. Available audiometric data at 1, 2, 3, and 5 years were used to assess prosthesis stability. Average postoperative air-conduction gain, air-bone gap, and sensorineural hearing level were measured at four frequencies: 0.5, 1, 2, and 4 kHz. Statistical analyses compared outcomes for HA TORP versus TI TORP and HA PORP versus TI PORP. RESULTS:Postoperative air-bone gap of less than 20 dB was obtained in 50% of HA TORP versus 45.8% of TI TORP cases and in 63.2% of HA PORP versus 72% of TI PORP cases. Preoperative middle ear status and presence/absence of malleus significantly influenced postoperative audiometric results. All types of prosthesis demonstrated significant postoperative air-conduction gain decrease on follow-up. Prosthesis exclusion was observed in three cases (1.78%). CONCLUSION:Prostheses using both types of biomaterial gave good functional results and stability with low exclusion rates, with no statistically significant differences between the two. Trends could be observed for slightly better results for HA in total reconstruction and for TI in partial reconstruction. The degradation in postoperative functional gain seemed to be independent of prosthesis type.

背景与目标：

BACKGROUND & AIMS: :Protein tyrosine nitration is a prevalent post-translational modification which occurs as a result of oxidative and nitrative stress, it may be directly involved in the onset and/or progression of diseases. Considering the existence of nano titanium dioxide (TiO(2)) in environment and sunscreen products along with the high content of nitrite in sweat, the UV-exposed skin may be a significant target for the photosensitized damage. In this paper, tyrosine nitration of bovine serum albumin (BSA) was initiated in the UV-irradiated reaction mixture containing 0.2-3.0mg/ml of three commercially nano TiO(2) products and 0.25-1.0mM NO2-. It was found that anatase TiO(2) and Degussa P25 TiO(2) showed prominent photocatalytic activity on promoting the formation of protein tyrosine nitration, and the optimum condition for the reaction was around physiological pH. Meanwhile, the photocatalytic effect of rutile on protein tyrosine nitration was subtle. The potential physiological significance of nano TiO(2)-photocatalytic protein nitration was also demonstrated in mouse skin homogenate. Although the relationship between photocatalytic protein tyrosine nitration and chronic cutaneous diseases needs further study, the toxicity of nano TiO(2) to the skin disease should be paid more attention in the production and utilization process.

背景与目标： : 蛋白质酪氨酸硝化是一种普遍的翻译后修饰，由于氧化和硝化应激而发生，它可能直接参与疾病的发生和/或进展。考虑到环境和防晒产品中存在纳米二氧化钛 (TiO(2))，同时汗液中亚硝酸盐含量高，紫外线暴露的皮肤可能是光敏损伤的重要目标。本文在含有0.2-3.0mg/ml三种商业纳米TiO(2) 产物和0.25-1.0毫米NO2-的UV辐照反应混合物中引发了牛血清白蛋白 (BSA) 的酪氨酸硝化反应。发现锐钛矿型TiO(2) 和Degussa P25 TiO(2) 对促进蛋白质酪氨酸硝化形成具有显着的光催化活性，反应的最佳条件是在生理pH附近。同时，金红石对蛋白质酪氨酸硝化的光催化作用微妙。在小鼠皮肤匀浆中也证明了纳米TiO(2)-光催化蛋白硝化的潜在生理意义。尽管光催化蛋白酪氨酸硝化与慢性皮肤病的关系有待进一步研究，但纳米TiO(2) 对皮肤病的毒性在生产和利用过程中应引起重视。

BACKGROUND & AIMS: :Monolayer transition metal dichalcogenides (TMDCs) including WS2, MoS2, WSe2 and WS2, are two-dimensional semiconductors with direct bandgap, providing an excellent field for exploration of many-body effects in 2-dimensions (2D) through optical measurements. To fully explore the physics of TMDCs, the prerequisite is preparation of high-quality samples to observe their intrinsic properties. For this purpose, we have focused on high-quality samples, WS2 grown by chemical vapor deposition method with hexagonal boron nitride as substrates. We observed sharp exciton emissions, whose linewidth is typically 22~23 meV, in photoluminescence spectra at room temperature, which result clearly demonstrates the high-quality of the current samples. We found that biexcitons formed with extremely low-excitation power (240 W/cm2) at 80 K, and this should originate from the minimal amount of localization centers in the present high-quality samples. The results clearly demonstrate that the present samples can provide an excellent field, where one can observe various excitonic states, offering possibility of exploring optical physics in 2D and finding new condensates.

背景与目标： : 包括WS2，MoS2，WSe2和WS2在内的单层过渡金属二卤化物 (TMDCs) 是具有直接带隙的二维半导体，为通过光学测量探索二维 (2D) 的多体效应提供了极好的领域。要充分探索TMDCs的物理原理，前提是准备高质量的样品以观察其固有特性。为此，我们专注于高质量的样品，WS2通过化学气相沉积法以六方氮化硼为基底生长。我们在室温下的光致发光光谱中观察到明显的激子发射，其线宽通常为22〜23  meV，结果清楚地表明了当前样品的高质量。我们发现双激子在80  K时具有极低的激发功率 (240  W/cm2)，这应该源于目前高质量样品中最小的定位中心。结果清楚地表明，本样品可以提供一个极好的领域，可以观察到各种激子态，为探索2D光学物理和寻找新的冷凝物提供了可能性。

BACKGROUND & AIMS: BACKGROUND:The purpose of this study was to investigate the influences of nanoscale wear particles derived from titanium/titanium alloy-based implants on integration of bone. Here we report the potential impact of titanium oxide (TiO2) nanoparticles on adhesion, migration, proliferation, and differentiation of mesenchymal stem cells (MSC) from the cellular level to the molecular level in the Wistar rat. METHODS:A series of TiO2 nanoparticles (14 nm, 108 nm, and 196 nm) were synthesized and characterized by scanning electron microscopy and transmission electron microscopy, respectively. RESULTS:The TiO2 nanoparticles had negative effects on cell viability, proliferation, and the cell cycle of MSC in a dose-dependent and size-dependent manner. Confocal laser scanning microscopy was used to investigate the effects of particle internalization on adhesion, spreading, and morphology of MSC. The integrity of the cell membrane, cytoskeleton, and vinculin of MSC were negatively influenced by large TiO2 nanoparticles. CONCLUSION:The Transwell migration assay and a wound healing model suggested that TiO2 nanoparticles had a strong adverse impact on cell migration as particle size increased (P < 0.01). Furthermore, alkaline phosphatase, gene expression of osteocalcin (OC) and osteopontin (OPN), and mineralization measurements indicate that the size of the TiO2 nanoparticles negatively affected osteogenic differentiation of MSC.

背景与目标：