Effect of different physical factors on the synthesis of spherical gold nanoparticles towards cost‐effective biomedical applications

Gold nanoparticles (AuNPs) have great potential to contribute to numerous application fields of biomedicine, which are highly dependent on their physicochemical properties, such as size and shape. Due to the final characteristics, nanoparticles (NPs) are primarily affected by different factors of reaction conditions; the present study aimed to evaluate the effects of manipulating the main physical parameters of the Turkevich method to optimise the fabrication of citrated capped AuNPs in a spherical shape, desirable final size, and efficiency. For this purpose, various experiments of citrate‐capped spherical AuNPs synthesis were designed to study the roles of a wide range of initial pH values and temperature of reaction, Na₃Cit/HAuCl₄ molar ratio, and two order reagent additions, method I and method II, in the final characterisations and reaction efficacy. Prepared NPs synthesised with different experiments were characterised by dynamic light scattering, UV‐Visible, and fourier transform infrared spectroscopy. Furthermore, NPs obtained from optimised synthesis conditions were more detailed using UV‐Visible, transmission electron microscopy, and XRD. The findings indicated that the final size and synthesis efficacy of citrated capped spherical AuNPs were significantly affected by all studied synthesis parameters and the order addition of reagents. The higher initial reaction temperature and Na₃Cit/HAuCl₄ Molar ratio provided a smaller particle size with desirable synthesis efficacy. Besides, final optimised NPs were provided in cubic crystal structures, and each NP''s single crystal was obtained. In sum, our findings indicated that optimising synthesis conditions could improve size distribution, morphology, crystallite size, and structures of final NPS, as well as efficiency, which is a principal factor associated with future cost‐effective productions on large scales. Further studies are needed in this regard.     

An exact schedulability test for fixed-priority preemptive mixed-criticality real-time systems

The current literature of fixed-priority scheduling algorithms relies on sufficient tests to determine if a set of mixed-criticality sporadic tasks is schedulable on a single processor. The drawback of these safe tests is their pessimism, a matter that could be solved if an exact schedulability analysis is used. However, because of the non-deterministic behavior of tasks in the mentioned setups, exact quantification of worst-case response times, needed for the test, is a difficult problem; more precisely, such a quantification needs evaluation of enormous sequences of job executions. The core problem is thus to merge such sequences to make the analysis practical. This paper, for the first time, gives an algorithm for exact worst-case response time characterization of mixed-criticality sporadic real-time tasks executing according to a given fixed-priority scheduler. We use a set of techniques which carefully consider the task properties and their relation to the worst scenarios to prune the analysis state space. We also show an interesting result that if an exact schedulability test is used, the Audsley’s optimal priority assignment algorithm is not applicable to the mixed-criticality case. Accordingly, we need new priority assignment algorithms to work with the exact test; we give a simple task priority assignment algorithm to this aim. The performance of the proposed exact test (in terms of time complexity) is examined and the effectiveness of some heuristic priority assignment algorithms using the test (in terms of the ratio of task sets which are deemed schedulable) are compared.     

Goals in conflict: semantic foundations of goals in agent programming

This paper addresses the notion of (declarative) goals as used in agent programming. Goals describe desirable states, and semantics of these goals in an agent programming context can be defined in various ways. We focus in this paper on the representation of conflicting goals. In particular, we define two semantics for goals, one for unconditional goals and one for conditional goals. The first is based on propositional logic, and the latter is based on default logic. We establish relations between and properties of these semantics. This title was inspired by the title of the PhD thesis of Harrenstein: Logic in conflict: logical explorations in strategic equilibrium [25].     

Utilization of Pharmacological Ascorbate to Enhance Hydrogen Peroxide-Mediated Radiosensitivity in Cancer Therapy

Interest in the use of pharmacological ascorbate as a treatment for cancer has increased considerably since it was introduced by Cameron and Pauling in the 1970s. Recently, pharmacological ascorbate has been used in preclinical and early-phase clinical trials as a selective radiation sensitizer in cancer. The results of these studies are promising. This review summarizes data on pharmacological ascorbate (1) as a safe and efficacious adjuvant to cancer therapy; (2) as a selective radiosensitizer of cancer via a mechanism involving hydrogen peroxide; and (3) as a radioprotector in normal tissues. Additionally, we present new data demonstrating the ability of pharmacological ascorbate to enhance radiation-induced DNA damage in glioblastoma cells, facilitating cancer cell death. We propose that pharmacological ascorbate may be a general radiosensitizer in cancer therapy and simultaneously a radioprotector of normal tissue.     

Preparation of mesoporous nanocrystalline 10% Ni/Ce1−xMnx O2 catalysts for dry reforming reaction

Methane dry reforming (MDR) was employed for the syngas production over 10% Ni/Ce_1?xMn_xO₂ (x = 0, 0.05, 0.25, 0.50, 0.75 and 1) catalysts. The obtained results indicated that the incorporation of Mn to the cerium oxide improved the BET area. However, there was an optimum content of Mn, in which the composite material exhibited the highest BET area. Addition of Mn more than 50 mol.% declined the BET area and significantly raised the mean pore size. The catalytic results indicated that the incorporation of Mn into the catalyst carrier slightly decreased the catalytic activity. However, the catalytic stability improved upon the addition of Mn. The TPO analysis confirmed the decrease in the amount of deposited carbon with the increase of Mn content. The whisker type carbon was observed on the surface of the spent catalysts. The catalytic results showed that the 10% Ni/Ce_0.95Mn_0.05O₂ exhibited the highest catalytic performance in methane reforming with carbon dioxide.     

Multi-objective exergy-based optimization of a continuous photobioreactor applied to produce hydrogen using a novel combination of soft computing techniques

This work was aimed at proposing a flexible and reliable framework based on combination of three soft computing techniques, i.e., artificial neural network, genetic algorithm, and fuzzy systems for multi-objective exergetic optimization of continuous photobiohydrogen production process from syngas by Rhodospirillum rubrum bacterium. To this end, artificial neural network (ANN) coupled with fuzzy clustering method (FCM) to model exergetic outputs on the basis of input variables. The outputs of modeling system were then fed into a novel optimization approach developed by hybridizing additive linear interdependent fuzzy multi-objective optimization (ALIFMO) and the elitist non-dominated sorting genetic algorithm (NSGA-II). The optimization was carried out to minimize the normalized exergy destruction and maximize the rational and process exergetic efficiencies, simultaneously. The solutions of the proposed approach were also compared with conventional fuzzy multi-objective optimization procedure with independent objectives. Overall, the modeling system predicted the exergetic parameters of photobioreactor with a coefficient of determination higher than 0.90. Furthermore, the optimization approach suggested syngas flow rate of 13.35 mL/min and agitation speed of 383.34 rpm as the best operational condition by considering the preferences of process exergy efficiency, rational exergy efficiency, and normalized exergy destruction, respectively. This condition could yield the normalized exergy destruction of 1.56, process exergetic efficiency of 21.66%, and rational exergetic efficiency of 85.65%. The obtained results showed the superiority of the proposed approach over the conventional fuzzy method in optimizing the complex biofuel production systems.     

Base-metal catalysts based on porous layered double hydroxides for alkaline-free sodium borohydride hydrolysis

Catalyzed hydrolysis of sodium borohydride (SBH) has demonstrated promise for generation of a pure hydrogen stream for use with fuel cells. In designing an improved continuous hydrogen generator that uses the substantial heat released in the hydrolysis reaction to more effectively separate the sodium borate by-product, we sought a robust base-metal catalyst that could tolerate the exothermic reaction under flow conditions. Working under base-free conditions in ethanol solvent we identified reduced nickel and iron-containing particles supported on layered double hydroxides (LDHs) as robust catalysts. Catalytic activity was enhanced further using high surface area hierarchical supports prepared using the ‘inverse opal’ method. In particular, macroporous NiMgAl and FeMgAl LDHs produced 0.4 and 1.0 mol of hydrogen per minute per mole of active metal of the supported catalyst in aqueous ethanol solvent.     

Designing an ultra-high-speed multiply-accumulate structure

In this article, an ultra-high-speed multiply-accumulate (MAC) structure is proposed. This fused MAC block uses low-voltage-swing (LVS) technique in the utilized carry-save adders and the final adder to improve its speed. Carry-save adders and the final adder are implemented with pass-transistor-based Manchester-carry-chain logic. Sense amplifiers are used in the output nodes to amplify the LVS signals to the standard levels of zero and one. With this technique, we achieved the outstanding clock frequency of 15 GHz for a five-stage pipelined MAC, which is 87.5% higher than the highest speed achieved for a pipelined multiplier in 65 nm technology and above, with the power consumption of 25 mW/GHz in 1.2 V voltage supply.     

Synthesis,spectral characterization,properties and structure of dinuclear rhenium complex containing bis[4-(2-pyridylmethyleneamino)phenyl]methane ligand

The synthesis, characterization, properties and crystal structure of {(bis[4-(2-pyridylmethyleneamino)phenyl]methane)[Re(CO)₃Br]₂} complex are reported. The ¹H NMR data for this complex shows downfield shift of the bis-diimine ligand protons upon coordination to the Re center. The molecular structure of the dinuclear rhenium(I) complex exhibits distorted octahedral geometries around the each metal center with one Br and facial arrangement of three CO and a cis-bonded diimine ligands. The bis-diimine ligand, twists via a half-turn around the metal–metal axis. Electrochemical investigation reveals two oxidation waves and two irreversible reduction waves.     

The in-vitro digestibility and chemical composition of plant parts in white clover,red clover and lucerne during primary growth

White clover (cv. Grasslands Huia), red clover (cv. Norseman) and lucerne (cv. Sabilt) were sampled during primary growth at the flower bud, near full flowering and seeds formed stages in each of 2 years. Each sample was separated into 2–11 plant parts, depending on species and stage of growth, and for each part the in-vitro true dry matter digestibility, digestibility of cell wall and percentages of cell content, nitrogen, water-soluble carbohydrate and lignin were determined. Green leaflets of all three species were consistently high in digestibility. The cell wall fraction of green leaflets was less digestible in red clover than in white clover and lucerne. The digestibility of the upper part of the stem of lucerne and red clover was high at the flower bud stage but declined considerably thereafter, whereas the digestibility of the lower part of the stem was much lower at the flower bud stage and declined relatively little. The green leaf stalks and inflorescences were generally rather less digestible than green leaflets and, in lucerne and red clover, more digestible than stems. In white clover the inflorescence stalks were less digestible than the leaf stalks. The digestibility of plant parts was strongly correlated with the proportion of cell content, and less strongly with the digestibility of cell wall. The proportion of cell content was positively correlated with N%, and the digestibility of cell wall was negatively correlated with the proportion of lignin in cell wall.