Mixed oxide nanotubes in nanomedicine: A dead-end or a bridge to the future?

Nanomedicine has seen a significant rise in the development of new research tools and clinically functional devices. In this regard, significant advances and new commercial applications are expected in the pharmaceutical and orthopedic industries. For advanced orthopedic implant technologies, appropriate nanoscale surface modifications are highly effective strategies and are widely studied in the literature for improving implant performance. It is well-established that implants with nanotubular surfaces show a drastic improvement in new bone creation and gene expression compared to implants without nanotopography. Nevertheless, the scientific and clinical understanding of mixed oxide nanotubes (MONs) and their potential applications, especially in biomedical applications are still in the early stages of development. This review aims to establish a credible platform for the current and future roles of MONs in nanomedicine, particularly in advanced orthopedic implants. We first introduce the concept of MONs and then discuss the preparation strategies. This is followed by a review of the recent advancement of MONs in biomedical applications, including mineralization abilities, biocompatibility, antibacterial activity, cell culture, and animal testing, as well as clinical possibilities. To conclude, we propose that the combination of nanotubular surface modification with incorporating sensor allows clinicians to precisely record patient data as a critical contributor to evidence-based medicine.     

A cost-based algorithm for design of Cellular Manufacturing Systems

This paper describes a cost-based algorithm that deals with the design problems of Cellular Manufacturing Systems (CMS) associated exceptional parts and bottleneck machines. The developed algorithm employes explicitly the main elements of manufacturing costs, such as the fixed machine cost, the production cost, the setup cost, and the material handling cost. The algorithm is based on the minimization of sum of these costs, and considers three alternatives to solve exceptional issues. The first alternative is to try to eliminate the maximum number of intercellular movements from the presently configured manufacturing system by buying and installing extra bottleneck machines into the appropriate cells. The second alternative considers the alternative process plans available and tries to complete the job using the overtime basis in the small machine cells. The third alternative considers the possibility of subcontracting the processing operations of exceptional part(s) to outside vendors to reduce the overall cost for the manufacturing system. The total costs of the three cases are compared and the best alternative for any given problem is identified. In order to illustrate performance of the algorithm developed, a test example is provided.     

Automatic features extraction of faults in PEM fuel cells by a siamese artificial neural network

In this paper, a procedure aimed at the automatic extraction of the features from polymer electrolyte membrane fuel cell impedance spectra is proposed. An artificial neural network that is trained by exploiting the similarity learning concept has been used. The network learns the features of the impedance spectra and maps each of them into the embedding space by clustering them accurately and by emphasising differences among spectra corresponding to different faults. The siamese network structure is optimised and the quality of the learnt representation is evaluated by analysing the clusters obtained in the features space. The dataset of experimental spectra has been augmented in two different ways and the results are compared. The clustering quality of the proposed siamese network is compared with the one of other state of the art approaches.     

Boosting alcohol electro-oxidation reaction with bimetallic PtRu nanoalloys supported on robust Ti0.7W0.3O2 nanomaterial in direct liquid fuel cells

In this work, an anatase Ti_0.7W_0.3O₂-supported Pt₃Ru nanoparticles (NPs) were fabricated by combining the advantages of the non-carbon Ti_0.7W_0.3O₂ nanosupport and the synergistic effect of the bimetallic Pt₃Ru nanoalloy that was investigated as electrocatalyst toward alcohol electrochemical oxidation. The bimetallic Pt₃Ru nanoparticles with ~3 nm in diameter were relatively well-dispersed on the surface of the anatase Ti_0.7W_0.3O₂ nanosupport via a surfactant-free microwave-assisted polyol route that, which was attributable to the good dispersibility of ethylene glycol and the rapid, uniformity of the microwave heating. For methanol and ethanol electrochemical oxidation, the as-obtained Pt₃Ru (NPs)/Ti_0.7W_0.3O₂ electrocatalyst exhibited the low onset potential (~0.10 V vs. NHE for MOR and ~0.35 V vs. NHE for EOR) and high mass activity (~350.84 mA mg_Pt^?1 for MOR and ~274.59 mA mg_Pt^?1 for EOR) compared to the commercial Pt (NPs)/C (E-TEK) electrocatalyst. Additionally, the CO-stripping and CA results indicated the remarkably enhanced CO-tolerance of the Pt₃Ru (NPs)/Ti_0.7W_0.3O₂ catalyst. After the 5000-cycle accelerated durability test (ADT) in acidic ethanol media, the bimetallic Pt₃Ru (NPs)/Ti_0.7W_0.3O₂ catalyst only showed the mass activity loss of 19.11% of its initial mass activity, compared with the severe deterioration of 44.04% of the commercial Pt (NPs)/C (E-TEK) catalyst. The outstanding results could be interpreted due to the bifunctional mechanism of the Pt₃Ru nanoalloys combining with the synergistic effect between the bimetallic nanoalloy and the mesoporous Ti_0.7W_0.3O₂ nanosupport as well as the superior anti-corrosion of the TiO₂-based nanosupport under acidic and oxidative environments.     

Electrokinetic motion of particles and cells in microchannels

This paper provides an overview of the electrokinetic phenomena associated with particles and cells in microchannel systems. The most important phenomena covered include electrophoresis, dielectrophoresis, and induced-charge electrokinetics. The latest development of these electrokinetic techniques for particle or cell manipulations in microfluidic systems is reviewed, in terms of the basic theories, mathematical models, numerical and experimental methods, and the key results/findings from the published literatures in the most recent decades. Some of the limitations associated with the negative field effects are discussed and the perspectives for the future investigations are summarized.     

Hydrogen production by sorption enhanced steam reforming of oxygenated hydrocarbons (ethanol, glycerol, n-butanol and methanol): Thermodynamic modelling

Thermodynamic analysis of steam reforming of different oxygenated hydrocarbons (ethanol, glycerol, n-butanol and methanol) with and without CaO as CO₂ sorbent is carried out to determine favorable operating conditions to produce high-quality H₂ gas. The results indicate that the sorption enhanced steam reforming (SESR) is a fuel flexible and effective process to produce high-purity H₂ with low contents of CO, CO₂ and CH₄ in the temperature range of 723-873 K. In addition, the separation of CO₂ from the gas phase greatly inhibits carbon deposition at low and moderate temperatures. For all the oxygenated hydrocarbons investigated in this work, thermodynamic predictions indicate that high-purity hydrogen with CO content within 20 ppm required for proton exchange membrane fuel cell (PEMFC) applications can be directly produced by a single-step SESR process in the temperature range of 723-773 K at pressures of 3-5 atm. Thus, further processes involving water-gas shift (WGS) and preferential CO oxidation (COPROX) reactors are not necessary. In the case of ethanol and methanol, the theoretical findings of the present analysis are corroborated by experimental results from literature. In the other cases, the results could provide an indication of the starting point for experimental research. At P = 5 atm and T = 773 K, it is possible to obtain H₂ at concentrations over 97 mol% along with CO content around 10 ppm and a thermal efficiency greater than 76%. In order to achieve such a reformate composition, the optimized steam-to-fuel molar ratios are 6:1, 9:1, 12:1 and 4:1 for ethanol, glycerol, n-butanol and methanol, respectively, with CaO in the stoichiometric ratio to carbon atom.     

人PSCA真核表达载体的构建及表达

目的构建含有信号肽及FLAG标签的人前列腺干细胞抗原(PSCA)真核表达载体,并在人胚肾293T细胞中进行表达。方法通过PCR方法获得SIG-FLAG基因片段及人PSCA基因片段,插入到真核表达载体pIRES-neo中。构建的重组质粒pIRES-neo-sig-FLAG-PSCA转染293T细胞,利用流式细胞仪、免疫荧光及RT-PCR方法检测其表达情况。结果PCR扩增出的SIG-FLAG及PSCA基因测序正确,酶切鉴定证明重组质粒pIRES-neo-sig-FLAG-PSCA构建成功;检测结果显示重组质粒pIRES-neo-sig-FLAG-PSCA在293T细胞中得到表达。结论成功构建了重组质粒pIRES-neo-sig-FLAG-PSCA,且在293T细胞中能有效表达,为后续转人PSCA基因细胞系的构建工作奠定了基础。     

Detection of mitochondrial DNA in living animal cells with fluorescence microscopy

The detection of mitochondrial DNA (mtDNA) in living human cells could be useful for understanding mitochondrial behaviour during cellular processes and pathological mtDNA depletions. However, until now, human mtDNA has not been visualized in living cells with fluorescence microscopy, although it has been easily detected in organisms with larger mtDNA. Previous reports have stated that mtDNA staining results in homogeneous fluorescence of mitochondria or that animal mitochondria are refractory to DAPI staining. This paper shows that mtDNA of cultured green monkey kidney CV-1 can be stained using a very low concentration of DAPI, then detected by a cooled Photometrics CCD camera with 14-bit resolution detection. Indeed, under these conditions CV-1 cells have small fluorescent spots in the cytoplasm that colocalize with mitochondria, even after mitochondrial movements, uncoupling by carbonyl cyanide p-(trifluoromethoxy)phenylhydrazone and swelling. These observations have been reproduced for the human fibroblast foreskin cell line HS68. These results and known properties of DAPI as a specific DNA stain strongly suggest that mtDNA can be detected and visualized by fluorescence microscopy in human living cells, with potential developments in the study of mtDNA in normal and pathological situations.     

Interaction Study of Yttria‐Based Glasses with High‐Temperature Electrolyte for SOFC

The chemical interaction study of AO–SiO₂–B₂O₃–Y₂O₃ (A = Ba, Sr) (BaY, SrY) glass with high‐temperature electrolyte yttria‐stabilized zirconia (YSZ 8 mol%) is reported as a function of different heat treatment durations. The as‐prepared glass with 10 mol% of yttria shows limited amount of crystallization at 800 °C. Due to this yttria‐based glasses BaY and SrY have been chosen to make diffusion couples with high‐temperature electrolyte and interconnect material. These diffusion couples have been heat treated at 850 °C, for 100, 200, and 500 h. The heat‐treated diffusion couples have been characterized using X‐ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS). Microstructural analysis of diffusion couples shows absence of any undesired oxides and detrimental reaction products at the interface. The glass has shown good bonding characteristics and absence of cracks, pores, or any kind of delamination from YSZ. Apart from this, SrY and BaY glass seals have also shown good adhesion characteristics with Crofer 22 APU, even after 500 h at 850 °C. The morphology and microstructure of the glass matrix suggest limited amount of devitrification in the glass.