The fabrication of nanoporous Pt-based multimetallic alloy nanowires and their improved electrochemical durability

A general approach for the fabrication of nanoporous Pt-based multimetallic alloy nanowires is reported, which involves electrodeposition of corresponding precursor alloys into porous anodic alumina templates, followed by a mild dealloying process. Nanoporous ternary PtCoNi and PtCoAu as well as quaternary PtRuCoNi nanowires were successfully fabricated, and their microstructure and composition were examined by transmission electron microscopy. Electrochemical tests showed that these porous nanowires exhibit higher electrochemically active surface area and much improved durability compared to commercially available Pt black, and may find potential applications in electrocatalysis and electrochemical sensing.     

Preparation and structural characterization of Zn1?xMnxSe thin films

Undoped and Mn doped ZnSe nanoparticles thin films of thickness ranging from 20 to 120 nm have been successfully synthesized via inert gas condensation (IGC) technique with constant Argon gas flow rate and deposition temperature 300 K. The energy dispersive X-ray analysis (EDX) for freshly deposited Zn_1−xMn_xSe thin films were carried out and revealed that Mn contents (x) were 0, 0.05, 0.16 and 0.25. The as-prepared deposited thin films of different thickness were examined using transmission electron microscope (TEM) and showed that all films were nanocrystalline with particle size ranging from 4.1 to 6.6 nm. The grazing incident in-plane X-ray diffraction (GIIXD) patterns verified nanocrystalline single phase zinc blende structure for 80 nm film thickness for all examined Zn_1−xMn_xSe compound films. A broadening of main characteristic lines (111), (220) and (311) of cubic phase was observed and was attributed to the lower particle size in nanocrystalline examined Zn_1−xMn_xSe compound films.     

应变率对全焊节点影响的试验和数值分析

对2个梁柱焊接节点的足尺试件进行动力试验。为了模拟试件的非线性动力性能,用纤维梁单元模拟梁、柱,用非线性旋转弹簧模拟焊接节点。对每一纤维,均采用Perzyna准则考虑应变率对梁、柱性能的影响。通过改进Richard静力模型模拟动力性能,考虑应变率对焊接节点的影响。Krawin-kler-Zoheri模型是标准累积塑性应变的函数,可根据应变率影响量化损伤和退化性能。将有限元分析软件DRAIN-2DX升级,建立模型并进行数值分析。与试验结果比较可知,考虑应变率影响和损伤累积的数值模拟能很好预测结构动力性能,甚至能预测焊接节点的破坏模式。     

The PINK1 p.Asn521Thr Variant Is Associated with Earlier Disease Onset in GRN/C9orf72 Frontotemporal Lobar Degeneration

Genetic frontotemporal lobar degeneration (FTLD) is characterized by heterogeneous phenotypic expression, with a disease onset highly variable even in patients carrying the same mutation. Herein we investigated if variants in lysosomal genes modulate the age of onset both in FTLD due to GRN null mutations and C9orf72 expansion. In a total of 127 subjects (n = 74 GRN mutations and n = 53 C9orf72 expansion carriers), we performed targeted sequencing of the top 98 genes belonging to the lysosomal pathway, selected based on their high expression in multiple brain regions. We described an earlier disease onset in GRN/C9orf72 pedigrees in subjects carrying the p.Asn521Thr variant (rs1043424) in PTEN-induced kinase 1 (PINK1), a gene that is already known to be involved in neurodegenerative diseases. We found that: (i) the PINK1 rs1043424 C allele is significantly associated with the age of onset; (ii) every risk C allele increases hazard by 2.11%; (iii) the estimated median age of onset in homozygous risk allele carriers is 10–12 years earlier than heterozygous/wild type homozygous subjects. A replication study in GRN/C9orf72 negative FTLD patients confirmed that the rs1043424 C allele was associated with earlier disease onset (−5.5 years in CC versus A carriers). Understanding the potential mechanisms behind the observed modulating effect of the PINK1 gene in FTLD might prove critical for identifying biomarkers and/or designing drugs to modify the age of onset, especially in GRN/C9orf72-driven disease.     

Sustained Increase in Serum Glial Fibrillary Acidic Protein after First ST-Elevation Myocardial Infarction

Acute ischemic cardiac injury predisposes one to cognitive impairment, dementia, and depression. Pathophysiologically, recent positron emission tomography data suggest astroglial activation after experimental myocardial infarction (MI). We analyzed peripheral surrogate markers of glial (and neuronal) damage serially within 12 months after the first ST-elevation MI (STEMI). Serum levels of glial fibrillary acidic protein (GFAP) and neurofilament light chain (NfL) were quantified using ultra-sensitive molecular immunoassays. Sufficient biomaterial was available from 45 STEMI patients (aged 28 to 78 years, median 56 years, 11% female). The median (quartiles) of GFAP was 63.8 (47.0, 89.9) pg/mL and of NfL 10.6 (7.2, 14.8) pg/mL at study entry 0–4 days after STEMI. GFAP after STEMI increased in the first 3 months, with a median change of +7.8 (0.4, 19.4) pg/mL (p = 0.007). It remained elevated without further relevant increases after 6 months (+11.7 (0.6, 23.5) pg/mL; p = 0.015), and 12 months (+10.3 (1.5, 22.7) pg/mL; p = 0.010) compared to the baseline. Larger relative infarction size was associated with a higher increase in GFAP (ρ = 0.41; p = 0.009). In contrast, NfL remained unaltered in the course of one year. Our findings support the idea of central nervous system involvement after MI, with GFAP as a potential peripheral biomarker of chronic glial damage as one pathophysiologic pathway.     

氮在渣-钢间传质系数的测定

使用Al₂O₃坩埚在真空感应炉内测定了1600℃时氮在含C还原渣和钢液之间的总传质系数β_o.研究表明,β_o与气相中氮分压P_N2的大小有关,随着P_N2的增加β_o增大.由物料平衡计算得出,在本实验条件下,β_o为3.7×10^-4 cm/S.     

Experimental and mathematical modelling of magnetically labelled mesenchymal stromal cell delivery

A key challenge for stem cell therapies is the delivery of therapeutic cells to the repair site. Magnetic targeting has been proposed as a platform for defining clinical sites of delivery more effectively. In this paper, we use a combined in vitro experimental and mathematical modelling approach to explore the magnetic targeting of mesenchymal stromal cells (MSCs) labelled with magnetic nanoparticles using an external magnet. This study aims to (i) demonstrate the potential of magnetic tagging for MSC delivery, (ii) examine the effect of red blood cells (RBCs) on MSC capture efficacy and (iii) highlight how mathematical models can provide both insight into mechanics of therapy and predictions about cell targeting in vivo. In vitro MSCs are cultured with magnetic nanoparticles and circulated with RBCs over an external magnet. Cell capture efficacy is measured for varying magnetic field strengths and RBC percentages. We use a 2D continuum mathematical model to represent the flow of magnetically tagged MSCs with RBCs. Numerical simulations demonstrate qualitative agreement with experimental results showing better capture with stronger magnetic fields and lower levels of RBCs. We additionally exploit the mathematical model to make hypotheses about the role of extravasation and identify future in vitro experiments to quantify this effect.     

Corrosion inhibition by naturally occurringsubstances—I. The effect of Hibiscus subdariffa (karkade) extract on the dissolution of Al and Zn

The thermometric, the weight-loss and the galvanostatic polarization techniques wereused to establish the inhibition of the dissolution of Al and Zn in HCl and NaOH by different concentrations of aqueous extract of Hibiscus subdariffa (Karkade). The extent of corrosion inhibition as measured by the three techniques is comparable. The results indicated that the additive acts by way of adsorption on both cathodic and anodic corrosion areas. Curves representing the variation of the reaction number (R.N.), in thermometric experiments, and the decrease in weight as a function of the concentration of the additive, are invariably sigmoid in nature. When present in enough amounts, the additive decreases the dissolution rate by as much as 85 per cent of the value recorded in its absence.     

Stoffaustausch zwischen flüssigem Eisen und Schlacke beim Sprühraffinationsverfahren

Erläuterung des Sprühraffinationsverfahrens, bei dem eine Schmelze mit inertem Gas verdüst wird und die entstehenden Metalltropfen durch eine Raffinationsschlacke fallen. Erörterung der Gesetzmäßigkeiten für die Stoffaustauschvorgänge zwischen Metalltropfen und Schlacke. Bestimmung der mittleren Tropfengröße beim Versprühen von kohlenstoffgesättigtem Roheisen. Untersuchung der Wirkung der Sprühraffination am Beispiel der Entschwefelung des Roheisens mit Schlacken des Systems CaO–CaF₂–Al₂O₃ bei 1600 °C. Ermittlung des Stoffübergangskoeffizienten des Schwefels für den umgekehrt transitorischen Phasenkontakt und Vergleich mit Werten bei anderen Techniken des Phasenkontaktes Metall-Schlacke.