Small networks of polarized splicing processors are universal

In this paper, we consider the computational power of a new variant of networks of splicing processors in which each processor as well as the data navigating throughout the network are now considered to be polarized. While the polarization of every processor is predefined (negative, neutral, positive), the polarization of data is dynamically computed by means of a valuation mapping. Consequently, the protocol of communication is naturally defined by means of this polarization. We show that networks of polarized splicing processors (NPSP) of size 2 are computationally complete, which immediately settles the question of designing computationally complete NPSPs of minimal size. With two more nodes we can simulate every nondeterministic Turing machine without increasing the time complexity. Particularly, we prove that NPSP of size 4 can accept all languages in NP in polynomial time. Furthermore, another computational model that is universal, namely the 2-tag system, can be simulated by NPSP of size 3 preserving the time complexity. All these results can be obtained with NPSPs with valuations in the set \(\{-1,0,1\}\) as well. We finally show that Turing machines can simulate a variant of NPSPs and discuss the time complexity of this simulation.     

Different measures of sensitivity of recipe colour to random and proportional dye concentration error. Part 3: Observed repeatability in regard to predicted sensitivity

The essential question of the paper ‘Can the predicted sensitivity to random and/or proportional dye concentration errors assist in selecting the most repeatable recipes?’ was investigated using the laboratory dyeing of acrylic fabric with basic dyes. When the dye strength errors were not involved, the biggest scattering of the recipe colour in repeated dyeings was observed in the cases of light neutral target colours, where the predicted sensitivity to random concentration errors was also the highest. For a few low‐saturated targets, eight recipes with different predicted sensitivities to random errors were treated. In six cases out of the seven treated, those recipes less sensitive to random concentration errors generally performed better than the more sensitive ones, but the correlation was rather weak. For those cases when the dye strength errors were included, experiments were also carried out with several different recipes for a neutral medium‐lightness target colour.     

Studies on the electronic transport and optical properties of some new chelate modified polysulfones in thin films

The studied polymers (chelate modified polysulfones) have been prepared by the polycondensation reaction between chloro‐end‐capped polysulfones and bis(2,4‐dihydroxybenzaldehyde)Cu²⁺ in the dymethyl sulfoxide/dichlormethane system, in the presence of an aqueous sodium hydroxide solution. The temperature dependence of electrical conductivity and Seebeck coefficient of the respective polymers was investigated using thin‐film samples, deposited from chloroform solutions onto glass substrates. The polymers under study have typical semiconducting properties. The values of some characteristic parameters of the investigated polymers (for example, activation energy of electrical conduction, ratio of carrier mobilities, etc.) have been determined. The nature of the electrical conduction mechanism is discussed. The values of the optical bandgap energy are determined from the absorption spectra. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 100–106, 2006     

Morphological changes induced in erythrocyte membrane by the antiepileptic treatment: An atomic force microscopy study

Atomic force microscopy (AFM), a powerful characterization tool widely applied in problems in a large range of disciplines of the natural sciences, including cellular biology, was used to obtain information about the morphological changes induced in the erythrocyte membrane at the patients with epilepsy that undergo a long time treatment that operates upon one or several neuronal ionic channels, comparative with a healthy donor. This technique allowed non‐invasive imaging of erythrocyte membrane, revealing details and specific characteristics down to the nanometer level with characterization of surface texture parameters, such as average height, average roughness and coefficient of kurtosis at micrometer/nanometer resolution. For the healthy donor the AFM morphology appears to have all the characteristics of a normal red blood cell membrane. Instead, the closer examination of the erythrocytes membrane surface morphology for the samples collected from the patients diagnosed with epilepsy and treated with specific drugs did not reveal similar structures with those obtained for the healthy donor. The nanostructure of the membrane was drastically damaged, depending on the administrated treatment, and probably in time will affect their functionality. Therefore, the anticomital drugs have influence not only at the neuronal level, but also at the red blood cell level.     

‘Generation rent’ and the emotions of private renting: self-worth,status and insecurity amongst low-income renters

Abstract

The UK private-rented sector is increasingly accommodating a diverse range of households, many of whom are young people struggling to access other forms of housing. For those at the bottom end of the sector, who typically have limited economic resources, it is a precarious housing tenure due to its expense and insecurity, yet few studies have explored qualitatively the emotional consequences of this for well-being. We address this gap in the ‘generation rent’ literature by focusing attention on those voices that have been less prominent in the literature. Informed by the theoretical lens of ‘residential alienation’, our study illustrates the emotional toll of private renting upon low-income groups in a national context where state regulation is more limited. In doing so, we add nuance to the literature surrounding socio-economic differentiation within the UK private-rented sector. Our arguments are also relevant to an international audience given global concerns about housing precarity and the politics of housing.     

Manipulation and tracking of superparamagnetic nanoparticles using MRI

The use of magnetic fields in magnetic resonance imaging (MRI) for the tracking and delivery of chemotherapeutics bound to superparamagnetic nanoparticles offers a promising method for the non-invasive treatment of inoperable tumours. Here we demonstrate that superparamagnetic magnetite nanoparticles fabricated by an easily scalable method can be driven and tracked in real time at high velocities in vitro using MRI hardware. Force balance calculations are consistent with the magnetic properties of individual 10 nm diameter particles that move collectively as micron sized agglomerates with hydrodynamic diameter similar to that inferred from zero-magnetic-field dynamic light scattering measurements.     

The Role of Endothelium in COVID-19

The 2019 novel coronavirus, known as severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) or coronavirus disease 2019 (COVID-19), is causing a global pandemic. The virus primarily affects the upper and lower respiratory tracts and raises the risk of a variety of non-pulmonary consequences, the most severe and possibly fatal of which are cardiovascular problems. Data show that almost one-third of the patients with a moderate or severe form of COVID-19 had preexisting cardiovascular comorbidities such as diabetes mellitus, obesity, hypertension, heart failure, or coronary artery disease. SARS-CoV2 causes hyper inflammation, hypoxia, apoptosis, and a renin–angiotensin system imbalance in a variety of cell types, primarily endothelial cells. Profound endothelial dysfunction associated with COVID-19 can be the cause of impaired organ perfusion that may generate acute myocardial injury, renal failure, and a procoagulant state resulting in thromboembolic events. We discuss the most recent results on the involvement of endothelial dysfunction in the pathogenesis of COVID-19 in patients with cardiometabolic diseases in this review. We also provide insights on treatments that may reduce the severity of this viral infection.     

Volatile organic compound detection using nanostructured copolymers

Regioregular polythiophene-based conductive copolymers with highly crystalline nanostructures are shown to hold considerable promise as the active layer in volatile organic compound (VOC) chemresistor sensors. While the regioregular polythiophene polymer chain provides a charge conduction path, its chemical sensing selectivity and sensitivity can be altered either by incorporating a second polymer to form a block copolymer or by making a random copolymer of polythiophene with different alkyl side chains. The copolymers were exposed to a variety of VOC vapors, and the electrical conductivity of these copolymers increased or decreased depending upon the polymer composition and the specific analytes. Measurements were made at room temperature, and the responses were found to be fast and appeared to be completely reversible. Using various copolymers of polythiophene in a sensor array can provide much better discrimination to various analytes than existing solid state sensors. Our data strongly indicate that several sensing mechanisms are at play simultaneously, and we briefly discuss some of them.     

Magnesia supported Au and Ag catalysts for the preparation of few-layer graphene–metal nanocomposites: relationship between catalyst structure and the properties of graphene composites

Magnesia supported Au, Ag, and Au–Ag nanostructured catalysts were prepared, characterized, and used to synthesize few-layer graphene–metal nanoparticle (Gr–MeNP) composites. The catalysts have a mezoporous structure and a mixture of MgO and MgO·H₂O as support. The gold nanoparticles (AuNPs) are uniformly dispersed on the surface of the Au/MgO catalysts, and have a uniform round shape with a medium size of ~8 nm. On the other hand, the silver nanoparticles (AgNPs) present on the Ag/MgO catalyst have an irregular shape, larger diameters, and less uniform dispersion. The Au–Ag/MgO catalyst contains large Au–Ag bimetallic particles of ~20–30 nm surrounded by small (5 nm) AuNPs. Following the RF-CCVD process and the dissolution of the magnesia support, relative large, few-layer, wrinkled graphene sheets decorated with metal nanoparticles (MeNPs) are observed. Graphene–gold (Gr–Au) and graphene–silver (Gr–Ag) composites had 4–7 graphitic layers with a relatively large area and similar crystallinity for samples prepared in similar experimental conditions. Graphene–gold–silver composites (Gr–Au–Ag) presented graphitic rectangles with round, bent edges, higher crystallinity, and a higher number of layers (8–14). The MeNPs are encased in the graphitic layers of all the different samples. Their size, shape, and distribution depend on the nature of the catalyst. The AuNPs were uniformly distributed, had a size of about 15 nm, and a round shape similar to those from Au/MgO catalyst. In Gr–Ag, the AgNPs have a round shape, very different from that of the Ag/MgO catalyst, large size distribution and are not uniformly distributed on the surface. Agglomerations of AgNPs together with large areas of pristine few-layer graphene were observed. In Gr–Au–Ag composites, almost exclusively large bimetallic particles of about 25–30 nm, situated at the edge of graphene rectangles have been found.