Magnetron Sputtered CsPbCl3 Perovskite Detectors as Real-Time Dosimeters for Clinical Radiotherapy

The aim of this study is to investigate the feasibility of manufacturing thin real-time relative dosimeters for clinical radiotherapy (RT) with potential applications for transmission monitoring in vivo dosimetry and pre-treatment dose verifications. Thin (≈1 μm) layers of a high sensitivity, wide bandgap semiconductor, the inorganic perovskite CsPbCl₃, have been grown for the first time by magnetron sputtering on plastic substrates equipped with electrode arrays. Prototype devices have been tested in real-time configuration to evaluate the dose delivered by a 6 MV photon beam from a linear accelerator. Linearity of the charge with the dose has been verified over three order of magnitudes, linearity of the current signal with the dose rate has been also successfully tested in the range 0.5-4.3 Gy/min. The combination of high sensitivity per unit volume and wide bandgap provides high signal-to-noise ratios, up to 70, even at moderate applied voltages. The Schottky diode configuration allows the detector to operate without bias voltage (null bias).The blocking-barrier structure allows to confine the active volume within sub-millimetric sizes, a quite attractive feature in view to increase granularity and achieve the high spatial resolutions required in modern RT techniques. All the above-mentioned features indeed pave the way to a novel generation of flexible, transmission, real time dosimeters for clinical radiotherapy.     

Self-reported metal hypersensitivity in patients undergoing unicondylar knee arthroplasty

ObjectivesThere is ongoing discussion about arthroplasty surgery of patients with metal hypersensitivity. The aim of this study was to compare the functional outcomes and eosinophil counts of unicondylar knee arthroplasty (UKA) patients with and without a history of metal hypersensitivity.MethodsA retrospective review was made of the medical records of 148 extremities of 140 consecutive patients who underwent primary UKA between January 2016 and December 2017. The patients who met the inclusion criteria were screened for history of metal hypersensitivity using a questionnaire. The functional outcomes of patients and eosinophil levels were evaluated immediately before and at 6 weeks after surgery.ResultsThe mean follow-up period was 37 months (range, 18–48 months). Of the total 128 patients, 13 (10.2%) reported a history of metal hypersensitivity before the operation. There was no statistically significant difference between patients with or without a history of metal hypersensitivity in respect of the functional outcomes or eosinophil counts (p > 0.05).ConclusionsThe results of this study showed that the functional outcomes of patients who underwent UKA using a standard alloy did not change between the groups who reported having or not having a history of metal hypersensitivity. Although the study also showed that the eosinophil counts decreased after surgery compared to the preoperative counts, there was no statistical relationship between the eosinophil count and functional outcomes or metal hypersensitivity history.     

Biochemical responses revealed in an amphibian species after exposure to a forgotten contaminant: An integrated biomarker assessment

Vanadium is a metal whose toxicity towards terrestrial and aquatic species has been under-reported to date.. The biochemical responses of vanadium in amphibian species have not been determined. To establish the effects of vanadium (V) on exposed adult Xenopus laevis, acute and chronic exposures were conducted, and biomarker analyses were performed on liver and muscle tissues from exposed frogs. Biomarkers of exposure, such as acetylcholinesterase (AChE) and metallothioneins (MT), were analysed. Biomarkers of effect were also analysed to determine possible increases in reactive oxygen species (ROS), and the effect of the exposure on the energy balance in the organisms. These included superoxide dismutase (SOD), catalase (CAT), reduced glutathione (GSH), protein carbonyls (PC), malondialdehyde (MDA), and cellular energy allocation (CEA) (energy available, energy consumption, lipids, proteins and glucose). In acute exposures, the energy balances in organisms were distinctly affected, possibly due to insulin mimetic properties of V. In chronic exposures, MT, AChE, SOD, CAT and GSH responses were more pronounced. Although AChE is generally inhibited by pollutant exposure, in this study, it was stimulated. There were significant inhibitions of SOD and CAT, previously observed in frog species. PC levels increased in the highest acute exposure concentration, indicating protein damage. The IBR.v2 revealed the biochemical responses of V more effectively than traditional statistical analysis.     

Biogenic silver,gold and copper nanoparticles - A sustainable green chemistry approach for cancer therapy

The advent of nanotechnology has revolutionized the way clinicians are treating cancers. Treatment for cancer includes surgery, radiotherapy, hormonal therapy, chemotherapy, and now nano therapy, which could be a possible alternative. This new treatment regime can be beneficial since it shows minimum side effects as compared to other treatment methods. Metallic nanoparticles synthesized through green chemistry by using biological entities minimizes the side effects and enhances the properties of the metal against cancer cells. These green nanoparticles are widely used in research and have shown promising cytotoxic activity against various cancer cell lines. Mechanistically, these nanoparticles can enter the cancer cell and cause cell death by the activation of various molecular pathways such as apoptosis, necrosis and autophagy. This review focuses on the metal nanoparticles (silver, gold and copper) synthesized by the green chemistry approach that have been utilized to study the cancer cell death and we are also discussing the underlying molecular pathways.     

Heteroepitaxy of Cerium Oxide Thin Films on Cu(111)

An important part of fundamental research in catalysis is based on theoretical and modeling foundations which are closely connected with studies of single-crystalline catalyst surfaces. These so-called model catalysts are often prepared in the form of epitaxial thin films, and characterized using advanced material characterization techniques. This concept provides the fundamental understanding and the knowledge base needed to tailor the design of new heterogeneous catalysts with improved catalytic properties. The present contribution is devoted to development of a model catalyst system of CeO₂ (ceria) on the Cu(111) substrate. We propose ways to experimentally characterize and control important parameters of the model catalyst—the coverage of the ceria layer, the influence of the Cu substrate, and the density of surface defects on ceria, particularly the density of step edges and the density and the ordering of the oxygen vacancies. The large spectrum of controlled parameters makes ceria on Cu(111) an interesting alternative to a more common model system ceria on Ru(0001) that has served numerous catalysis studies, mainly as a support for metal clusters.     

提高选题策划质量 提升行业期刊品牌影响力——以金属加工杂志社实践为例

【目的】 探讨行业期刊进行选题策划的方法,提升选题策划的质量。【方法】 利用互联网技术及新媒体资源,结合金属加工杂志社选题策划实例,归纳出几种选题策划的途径及方法。【结果】 结合行业热点进行选题策划,注重实效性和内容深度,提升期刊内容的可读性,可使期刊获得更多读者的关注和认可,提升期刊的行业影响力。【结论】 提高选题策划质量,可有效提升期刊内容的可读性,从而进一步提升期刊在行业的影响力。     

The effects of metal ion PCR inhibitors on results obtained with the Quantifiler® Human DNA Quantification Kit

Forensic DNA samples may include the presence of PCR inhibitors, even after extraction and purification. Studies have demonstrated that metal ions, co-purified at specific concentrations, inhibit DNA amplifications. Metal ions are endogenous to sample types, such as bone, and can be introduced from environmental sources. In order to examine the effect of metal ions as PCR inhibitors during quantitative real-time PCR, 2800 M DNA was treated with 0.0025–18.750 mM concentrations of aluminum, calcium, copper, iron, nickel, and lead. DNA samples, both untreated and metal-treated, were quantified using the Quantifiler^® Human DNA Quantification Kit. Quantification cycle (Cq) values for the Quantifiler^® Human DNA and internal PCR control (IPC) assays were measured and the estimated concentrations of human DNA were obtained. Comparisons were conducted between metal-treated and control DNA samples to determine the accuracy of the quantification estimates and to test the efficacy of the IPC inhibition detection. This kit is most resistant to the presence of calcium as compared to all metals tested; the maximum concentration tested does not affect the amplification of the IPC or quantification of the sample. This kit is most sensitive to the presence of aluminum; concentrations greater than 0.0750 mM negatively affected the quantification, although the IPC assay accurately assessed the presence of PCR inhibition. The Quantifiler^® Human DNA Quantification Kit accurately quantifies human DNA in the presence of 0.5000 mM copper, iron, nickel, and lead; however, the IPC does not indicate the presence of PCR inhibition at this concentration of these metals. Unexpectedly, estimates of DNA quantity in samples treated with 18.750 mM copper yielded values in excess of the actual concentration of DNA in the samples; fluorescence spectroscopy experiments indicated this increase was not a direct interaction between the copper metal and 6-FAM dye used to label the probe that targets human DNA in the Quantifiler^® kit. Evidence of inhibition was observed for the human-specific assay at a lower metal concentration than detected by the IPC, for all metals examined except calcium. These results strongly suggest that determination of a “true negative” sample should not be based solely on the failure of the IPC to indicate the presence of a PCR inhibitor and indicate that amplification of all samples should be attempted, regardless of the quantification results.     

Adherence of investment to Au–Pd–Ag alloy using a vacuum–argon pressure casting machine

OBJECTIVE: The removal of adhered investment material from marginal metal surfaces represents a possible risk of poor marginal adaptation.The aim of this work was to evaluate the effects of argon on investment adherence to the casting surface and on the alloy surface microstructure. METHODS: A die of stainless steel was used. 10 wax copings were cast by vacuum-argon pressure, while 10 copings by vacuum-air pressure using a Combilabor CLG-77 A in a graphite crucible; supply was direct with curved sprues of slashed circle 3.5 mm. The alloy used was Herabond. After coarse investment, removal of all specimens were investigated with scanning electron microscopy and semi-quantitative digital densitometry. RESULTS: The specimens cast under vacuum-argon pressure showed less amount of investment adhered (unpaired t test of grouped specimens, difference 2.896x10(5)pixel; p=0.002) while the grain size on the casting surface increased significantly p=0.000 (difference 5.968(microm). SIGNIFICANCE: Vacuum-argon pressure supply during casting reduces the investment adherence to the metal surface, and increases the packing density and size of the grains, especially on the casting surface. These minimize the risk of marginal distortions due to casting cleaning procedures and facilitate the finishing and polishing procedures.     

RG实验低熔瓷与钛的结合性能分析

目的　测试作者自行研制的RG实验低熔瓷与钛的结合性能。方法　铸造 1 0mm×5mm× 1 4mm钛片 5个 ,于钛片表面依次熔附RG实验遮色瓷和牙本质瓷总厚度 1mm。采用扫描电镜观察钛瓷界面形貌并做能谱分析。采用铸造法制备 2 8mm× 3mm× 0 5mm的NiCr合金试件6个 ,纯钛试件 1 8个。于NiCr合金试件中份 8mm× 3mm处熔附 1mmVita常用瓷 ;钛试件分为 3组 ,每组 6个 ,于试件中份 8mm× 3mm处分别熔附 1mmRG实验低熔瓷、VITATITANKERAMLK瓷和NoritakesuperporcelainTi 2 2瓷。在实验机上采用 3点弯曲法测试金瓷分离时的载荷。采用金瓷修复体制作方法制作RG实验钛瓷冠。结果　扫描电镜观察发现遮色瓷与钛之间无明显缝隙存在 ,遮色瓷与钛之间存在一个约 1 μm过渡层 ,能谱分析发现该过渡层的主要化学元素为Ti、Si、O。NiCr合金 VITA瓷试件的分离加载为 (1 2 733± 3 2 97)N ,钛 VITATITAN、钛 Noritake瓷试件和钛 RG实验瓷的分离加载分别为 (7 2 33± 2 539)N、(5 533± 1 1 99)N和 (6 31 6± 1 433)N。经统计检验 ,3种钛瓷试件之间差异无显著性 (P >0 0 5) ;而 3种钛瓷样本的分离加载均明显低于NiCr合金与瓷的分离载荷 ,差异有极显著性 (P <0 0 1 )。钛瓷冠瓷面完整无裂纹。结论　RG瓷与钛具有良好的结合