Synthesis, characterization and properties of a glycol-coordinated ε-Keggin-type Al13 chloride

Herein we present the first example of a glycol-coordinated ε-Keggin Al13 chloride (gl-ε-Al13), which is the first chelated version since discovery of Al13 in 1960. The molecular structure consists of [AlO4Al12(OH)12(OC2H4OH)12]Cl7·H2O units with chelating mono-anionic ethylene glycol units replacing one bridging and one terminal oxygen site.

Approaching single DNA molecule detection with an ultrasensitive electrochemical genosensor based on gold nanoparticles and cobalt-porphyrin DNA conjugates

We describe an ultrasensitive electrochemical genosensor based on gold nanoparticles and cobalt-porphyrin functionalised ssDNA probes. The sensitivity at the attomolar concentration level arises from an increased density of redox labels on the electrode surface compared to sensors without NP modification. The electrode detects as few as 23 DNA molecules, approaching single molecule detection.

Supported gold–nickel nano-alloy as a highly efficient catalyst in levulinic acid hydrogenation with formic acid as an internal hydrogen source

Gamma-valerolactone (GVL) is one of the key products of future biorefineries. We show here for the first time the superior activity of Ni-based, Au doped catalysts in levulinic acid hydrogenation towards GVL using formic acid as a hydrogen source. Their performances are strongly influenced by the preparation method, and the highest GVL yield is achieved for bimetallic Au–Ni catalysts prepared via co-impregnation of both metallic salts with a reductive thermal treatment under hydrogen. The very high catalytic activity is explained by the use of DFT calculations and the extensive characterization of the catalyst surface and bulk properties. We highlight the pivotal role played by the incorporated isolated metallic Ni atoms within Au nanoparticles. The nano-alloy composition is determined. It allows establishment of a surface model of such an alloy, thanks to which the high activity can be explained by the presence of an optimum energetic span of FA adsorption. The existence of strong interaction between Au and Ni in a surface alloy, Au–Ni, favors selective and fast decomposition of formic acid into hydrogen that consequently facilitates strongly the combined hydrogenation process.

Sequencing of human genomes extracted from single cancer cells isolated in a valveless microfluidic device

Sequencing the genomes of individual cells enables the direct determination of genetic heterogeneity amongst cells within a population. We have developed an injection-moulded valveless microfluidic device in which single cells from colorectal cancer derived cell lines (LS174T, LS180 and RKO) and fresh colorectal tumors have been individually trapped, their genomes extracted and prepared for sequencing using multiple displacement amplification (MDA). Ninety nine percent of the DNA sequences obtained mapped to a reference human genome, indicating that there was effectively no contamination of these samples from non-human sources. In addition, most of the reads are correctly paired, with a low percentage of singletons (0.17 ± 0.06%) and we obtain genome coverages approaching 90%. To achieve this high quality, our device design and process shows that amplification can be conducted in microliter volumes as long as the lysis is in sub-nanoliter volumes. Our data thus demonstrates that high quality whole genome sequencing of single cells can be achieved using a relatively simple, inexpensive and scalable device. Detection of genetic heterogeneity at the single cell level, as we have demonstrated for freshly obtained single cancer cells, could soon become available as a clinical tool to precisely match treatment with the properties of a patient's own tumor.

Role of disorder in limiting the true multi-electron redox in ε-LiVOPO4

Recent advances in materials syntheses have enabled e-LiVOPO4 to deliver capacities approaching, and in some cases exceeding the theoretical value of 305 mA h g−1 for 2Li intercalation, despite its poor electronic and ionic conductivity. However, not all of the capacity corresponds to the true electrochemical intercalation/deintercalation reactions as evidenced upon systematic tracking of V valence through combined operando and rate-dependent ex situ X-ray absorption study presented herein. Structural disorder and defects introduced in the material by high-energy ball milling impede kinetics of the high-voltage V5+/V4+ redox more severely than the low-voltage V4+/V3+ redox, promoting significant side reaction contributions in the high-voltage region, irrespective of cycling conditions. The present work emphasizes the need for nanoengineering of active materials without compromising their bulk structural integrity in order to fully utilize high-energy density of multi-electron cathode materials.

Analyzing transport properties of p-type Mg2Si–Mg2Sn solid solutions: optimization of thermoelectric performance and insight into the electronic band structure

Receptive Language Skills in Slovak-Speaking Children With Intellectual Disability: Understanding Words, Sentences, and Stories

The study aims to describe receptive language skills in children with intellectual disability (ID) and to contribute to the debate on deviant versus delayed language development. This is the 1st study of receptive skills in children with ID who speak a Slavic language, providing insight into how language development is affected by disability and also language typology.

Influence of irradiation on stability and effectiveness of TiO 2 /N,C photocatalysts

The gypsum building material was enriched with photocatalytic properties for indoor air purification. The photocatalytic additive to gypsum was TiO 2 modified with carbon from various sources. The photocatalytic activity of gypsum plates was performed towards NO x removal. Carbon doping into TiO 2 improved not only total degradation of NO x on corresponding gypsum plates but also NO 2 selectivity was changed, limiting the production of toxic NO 2 . The exhibition of photocatalysts on the visible and ultraviolet irradiation has been also carried out to examine their durability. First, the stability of modifying element – carbon in TiO 2 structure was analysed, indicating on the gradual reduction of carbon content with irradiation time, especially when the carbon source was cyclic hydrocarbon. Second, the photocatalytic activity of the gypsum plates was performed at each stage of the ageing process. Based on this insight, the correlation between carbon content in modified photocatalysts loaded to gypsum plates and photocatalytic activity of them was described in detail.

Research on chromium and arsenic speciation in atmospheric particulate matter: short review

Atmospheric particulate matter (PM) plays an important role in the distribution of elements in the environment. The PM-bound elements penetrates into the other elements of the environment, in two basic forms - those dissolved in the atmospheric precipitation and those permanently bound to PM particles. Those forms differs greatly in their mobility, thus posing a potential threat to living organisms. They can also be an immediate threat, while being inhaled. Chromium (Cr) and arsenic (As) belong to the group of elements whose certain chemical states exhibit toxic properties, that is Cr(VI) and As(III). Thus, recognition of the actual threat posed by Cr and As in the environment, including those present in PM, is possible only through the in depth speciation analysis. Research on the Cr and As speciation in PM, more than the analogous studies of their presence in other compartments of the environment, have been undertaken quite rarely. Hence the knowledge on the speciation of PM-bound As and Cr is still limited. The state of knowledge in the field of PM-bound Cr and As is presented in the paper. The issues related to the characterization and occurrence of Cr and As species in PM, the share of Cr and As species mass in different PM size fractions, and in PM of different origin is also summarized. The analytical techniques used in the speciation analysis of PM-bound Cr and As are also discussed. In the existing literature there is no data on the physical characteristics of Cr and As (bound to a different PM size fractions), and thus it still lack of data needed for a comprehensive assessment of the actual environmental and health threat posed by airborne Cr and As

Factors determining the concentration and chemical composition of particulate matter in the air of selected service facilities

The link between increased morbidity and mortality and increasing concentrations of particulate matter (PM) resulted in great attention being paid to the presence and physicochemical properties of PM in closed rooms, where people spends most of their time. The least recognized group of such indoor environments are small service facilities. The aim of this study was to identify factors which determine the concentration, chemical composition and sources of PM in the air of different service facilities: restaurant kitchen, printing office and beauty salon. The average PM concentration measured in the kitchen was 5-fold (PM4, particle fraction ≥ 4 μm) and 5.3-fold (TSP, total PM) greater than the average concentration of these PM fractions over the same period. During the same measurement period in the printing office and in the beauty salon, the mean PM concentration was 10- and 4-fold (PM4) and 8- and 3-fold (TSP) respectively greater than the mean concentration of these PM fractions in outdoor air. In both facilities the main source of PM macro-components, especially organic carbon, were chemicals, which are normally used in such places - solvents, varnishes, paints, etc. The influence of some metals inflow from the outdoor air into indoor environment of those facilities was also recognized