Milling as a route to porous graphitic carbons from biomass.

This paper reports a simple way to produce porous graphitic carbons from a wide range of lignocellulosic biomass sources, including nut shells, softwood sawdust, seed husks and bamboo. Biomass precursors are milled and sieved to produce fine powders and are then converted to porous graphitic carbons by iron-catalysed graphitization. Graphitizing the raw (unmilled) biomass creates carbons that are diverse in their porosity and adsorption properties. This is due to the inability of the iron catalyst precursor to penetrate the structure of dense biomass material. Milling enables much more efficient impregnation of the biomass and produces carbons with homogeneous properties. Lignocellulosic biomass (particularly waste biomass) is an attractive precursor to technologically important porous graphitic carbons as it is abundant and renewable. This simple method for preparing the biomass enables a wide range of biomass sources to be used to produce carbons with homogeneous properties. This article is part of the theme issue 'Bio-derived and bioinspired sustainable advanced materials for emerging technologies (part 2)'.

Virus-directed formation of electrocatalytically active nanoparticle-based Co3O4 tubes.

Spinel-type Co3O4 finds applications in a wide range of fields, including clean energy conversion, where nanostructured Co3O4 may provide a cost-efficient alternative to platinum- and iridium-based catalysts for electrocatalytic water-splitting. We here describe a novel strategy in which basic cobalt carbonate - a precursor to Co3O4 - is precipitated as sheet-like structures and microspheres covered with fine surface protrusions, via ammonium carbonate decomposition at room temperature. Importantly, these mild reaction conditions enable us to employ bio-inspired templating approaches to further control the mineral structure. Rod-like tobacco mosaic viruses (TMV) were used as biotemplates for mineral deposition, where we profit from the ability of Co(ii) ions to mediate the ordered assembly of the virus nanorods to create complex tubular superstructures of TMV/ basic cobalt carbonate. Calcination of these tubules is then achieved with retention of the gross morphology, and generates a hierarchically-structured solid comprising interconnected Co3O4 nanoparticles. Evaluation of these Co3O4 materials as electrocatalysts for the oxygen evolution reaction (OER) demonstrates that the activity of Co3O4 prepared by calcination of ammonia diffusion-grown precursors in both, the absence or presence of TMV exceeds that of a commercial nanopowder.

Electroluminescent method for determining hydrogen peroxide and peroxydisulphate ions in aqueous solution using TiO(2) film electrodes.

An electrochemical optical sensor system with luminescence response was proposed for the continuous determination of hydrogen peroxide or peroxydisulphate concentration in aqueous solutions. The electroluminescence (EL) of TiO(2) film electrodes, which arises under conditions of the cathodic polarization as a result of the hole injection into the TiO(2) from high-energy OH or SO(4)(2-) radicals produced by the electroreduction of H(2)O(2) or S(2)O(8)(2-) ions on the electrode surface, was used as the analytical signal. The EL response is linearly related, in a logarithmic scale, to the hydrogen peroxide or peroxydisulphate concentration ranging from 10(-3) to 10(-1) M H(2)O(2) and from 5 x 10(-4) to 1 M Na(2)S(2)O(8). It was shown that a substantial increase in the quantum efficiency of the EL and, as a consequence, in the sensitivity of the sensor system can be achieved by doping TiO(2) films with chromium. The potential dependence of the EL spectrum for TiO(2) electrodes in S(2)O(8)(2-) solutions differs essentially from that in H(2)O(2) solutions which allows measurement of the concentration of S(2)O(8)(2-) ions when they coexist with H(2)O(2) in solution.

Ultrasound fibrin clot destruction in vitro in the presence of fibrinolytic agent.

Ultrasound fibrin clot destruction was investigated in vitro using electron microscopy and by monitoring the changes in the light transmission of clot debris suspension. It has been established that in the course of a combined action of ultrasound and fibrinolytic agent at high ultrasound intensities and short sonification periods, fibrin clot is disrupted mainly due to sonomechanical treatment, while fermentative lysis takes place in parallel and at a significantly lower rate. However, the streptokinase action prevails after ultrasound switching off and results in the prevention of clot debris conglomeration.

Enhancement of sonoluminescence emission from a multibubble cavitation zone.

Investigations have been performed on various methods of increasing cavitation activity measured by the intensity of sonoluminescence. It is shown that the effect of the combined action of (a) pulsed modulation of an acoustic field, (b) liquid degassing and cooling and (c) increasing the static pressure considerably exceeds the sum of the effects achieved by each of these methods individually. A more than 250-fold increase of the sonoluminescence intensity has been attained compared with continuous irradiation under normal conditions (room temperature, atmospheric pressure, gas-saturated liquid). An interpretation of the results obtained is proposed.

Cavitation activity stimulation by low frequency field pulses.

The influence of a short-time action of a low-frequency ultrasound on the sonoluminescence generation by a high frequency pulsed field has been studied. This action remarkably lowers the cavitation thresholds and increases the sonoluminescence intensity. The stimulating effect of the low-frequency field action depends on its duration and on the intensities of both fields. Possible mechanisms of this effect are discussed.

Parallels between math and reading disability: common issues and approaches.

There is a relatively larger body of research on reading than on math disabilities. However, many research findings and theoretical issues are common to both areas of study. In this review, similarities in skill acquisition across domains are identified, and findings concerning the nature of the differences between learners with and without disabilities are discussed. Evaluating the areas of similarity and difference between reading and math disabilities may enhance our understanding of individual differences in learning abilities, and may be useful in guiding future research and theory development.

[The effectiveness of G. A. Ilizarov's method in treating patients with III- and IV-stage chronic ischemia of the lower extremities]. / Effektivnost' metoda G. A. Ilizarova pri lechenii bol'nykh s III i IV stadiiami khronicheskoi ishemii nizhnikh konechnostei.

The method of treatment after Ilizarov was used in 28 patients with occlusion of lower extremity arteries, mainly of distal localization, with the III and IV degrees of ischemia. Osteotomy of mainly the tibial bone and distraction of the free osseous split was performed during 31-36 days. Two patients had fractures of the bone during operative interventions, after operation four patients had purulent complications or necrosis of the skin around the wire. The immediate positive result was noted in 20 patients. Their fate was followed-up in remote periods from 2 to 19 months, good results were observed in 18 patients. The use of the Ilizarov method was most justified in patients with the III and IV degrees of ischemia when other methods of treatment failed to give any effect and surgical reconstruction of the vessels is impossible. When treating patients with the IV degree, it is necessary to take into consideration the late appearance of revascularization and possibility of temporary deterioration. The use of the Ilizarov method foresees provision of the joint work of an angiosurgeon and a traumatologist-orthopedist.

The role of NMDA and AMPA/Kainate receptors in the consolidation of catalepsy sensitization.

Daily injection of the dopamine D(2) receptor antagonist haloperidol is associated with the development of catalepsy sensitization in rats, which leads to a day to day increase of rigor and akinesia. The process of catalepsy sensitization incorporates different learning stages. Here we investigated the mechanisms underlying the consolidation of catalepsy sensitization. In particular, we asked whether NMDA- and non-NMDA (AMPA- and Kainate) receptors play a role in the consolidation of catalepsy sensitization. Accordingly, rats received post-training injections of the NMDA receptor antagonist MK-801 (single injection of either 0.1mg/kg or 0.25mg/kg; or a double injection of 0.1mg/kg immediately and 30 min after test cessation) or of the AMPA/Kainate receptor antagonist GYKI 52466 (single injection of 5mg/kg). Our results showed that the consolidation of catalepsy sensitization was decelerated by both glutamatergic AMPA/Kainate- and NMDA-receptor antagonists. With the higher MK-801 dosage, the deceleration was stronger, suggesting a dose dependent mechanism. We hence affirmed a role for the ionotropic glutamate receptors in the consolidation process of catalepsy sensitization.

Individual differences in the obligatory activation of addition facts.

In two experiments, we found evidence for individual differences in the obligatory activation of addition facts. Subjects were required to verify the presence of a target digit (e.g., 4) in a previously presented pair (e.g., 5+4). Subjects rejected targets that formed the sum of the initial pair (e.g., 5+4 and 9) more slowly than they rejected unrelated targets (e.g., 5+4 and 7). This interference of the sum was largest for subjects who were relatively skilled at multi-digit arithmetic. Less skilled subjects did not show statistically significant effects of obligatory activation. In comparison with less skilled subjects, skilled subjects showed differential interference on plus-one (e.g., 3+1) and standard (e.g., 2+3) problems when the plus sign was presented, and on ties (e.g., 2 2) when the plus sign was omitted. These results suggest that network models of arithmetic fact retrieval are appropriate for skilled subjects, but that alternative models need to be considered for less skilled individuals.

4-Nitro-2-(1H-tetrazol-1-yl)phenol.

There are two symmetry-independent molecules in the unit cell of the title compound, C(7)H(5)N(5)O(3). The tetrazole and phenyl rings are essentially planar and are not coplanar in either molecule [dihedral angles 30.2 (1) and 7.0 (1) degrees]. In the structure, four molecules are connected by O-H...N bridges, forming four-membered molecular aggregates which are linked together by a complex three-dimensional hydrogen-bond network.

2-(1H-tetrazol-1-yl)benzoic acid.

In the title compound, C8H6N4O2, the tetrazole and benzene rings are planar to within 0.001 (1) and 0.007 (1) A, respectively. These rings are not coplanar in the molecule, the dihedral angle between them being 52.90 (4) degrees. Molecules are connected together by O-H...N and C-H...O hydrogen bonds, forming two-dimensional networks parallel to the xz plane with van der Waals interactions between them.