Co-localization of Carbonic Anhydrase and Phosphoenol-pyruvate Carboxylase and Localization of Pyruvate Kinase in Roots and Hypocotyls of Etiolated Glycine max Seedlings

We investigated the presence of carbonic anhydrase in root and hypocotyl of etiolated soybean using enzymatic, histochemical, immunohistochemical and in situ hybridization approaches. In parallel, we used in situ hybridization and immunolocalization to determine the expression pattern and localization of phosphoenolpyruvate carboxylase. Their co-localization in the root tip as well as in the central cylinder, suggests that a large fraction of the CO₂ may be re-introduced into C4 compounds. GmPK3 expression, coding for a cytoplasmic isoform of pyruvate kinase, was detected in all different root cell types, suggesting that both phosphoenolpyruvate-utilizing enzymes are involved in phosphoenolpyruvate metabolism in etiolated soybean roots; a case indicative of the necessary flexibility plant metabolism has to adopt in order to compensate various physiological conditions.     

Surface-stabilized ferroelectric liquid-crystal diffraction gratings with micrometer-scale pitches

The first-order diffraction efficiency eta1 of surface-stabilized ferroelectric liquid-crystal (SSFLC) phase gratings is calculated for device thicknesses in the range d = 1 to 5 microm and for pitches p of 5 to 20 microm assuming incident light at 633 nm. The peak value of eta1 as a function of d has negligible dependence on the incoming polarization when p = 20 microm. For smaller pitch values the peak value of eta1 decreases and becomes increasingly dependent on the orientation of the incoming polarization owing to the influence of the domain walls that occur between the SSFLC pixels.     

A high-level synthesis of oil spill response equipment and countermeasures

This paper presents an operational synthesis of major oil spill response methods (mechanical, chemical, etc.) and the corresponding oil response equipment for sea context (booms, skimmers, etc.). We focus on important features of oil spill response, in order to formulate a decision-based database, capable of supporting the development of a complete oil spill response operation. Moreover, we classify these findings and introduce simple formatting and standards to supply predictive tools for oil spill models. The actual goal of this paper is to come up with a decision-driven process, which can provide for a realistic choice of oil spill response equipment in the design of the primary oil response phase. This is intended to lead to a prompt, logical, and well-prepared oil spill response operation satisfying time and cost criteria and protecting the marine environment.     

Development of an electrochemical metal-ion biosensor using self-assembled peptide nanofibrils

This article describes the combination of self-assembled peptide nanofibrils with metal electrodes for the development of an electrochemical metal-ion biosensor. The biological nanofibrils were immobilized on gold electrodes and used as biorecognition elements for the complexation with copper ions. These nanofibrils were obtained under aqueous conditions, at room temperature and outside the clean room. The functionalized gold electrode was evaluated by cyclic voltammetry, impedance spectroscopy, energy dispersive X-ray and atomic force microscopy. The obtained results displayed a layer of nanofibrils able to complex with copper ions in solution. The response of the obtained biosensor was linear up to 50 μM copper and presented a sensitivity of 0.68 μA cm?2 μM?1. Moreover, the fabricated sensor could be regenerated to a copper-free state allowing its reutilization.     

An empirical study on the commercial adoption of digital currencies

Information Systems and e-Business Management - Digital currencies are rapidly evolving Internet currencies that have been increasingly attracting academic, governmental, banking, and business...     

A semi-analytical refrigeration cycle modelling approach for a heat pump hot water heater

The use of heat pump systems in applications like the production of hot water or space heating makes important the modelling of the processes for the evaluation of the performance of existing systems, as well as for design purposes. The proposed semi-analytical model offers the opportunity to estimate the performance of a heat pump system producing hot water, without using detailed geometrical or any performance data. This is important, as for many commercial systems the type and characteristics of the involved subcomponents can hardly be detected, thus not allowing the implementation of more analytical approaches or the exploitation of the manufacturers’ catalogue performance data. The analysis copes with the issues related with the development of the models of the subcomponents involved in the studied system. Issues not discussed thoroughly in the existing literature, as the refrigerant mass inventory in the case an accumulator is present, are examined effectively.     

The Stretching Method for Vibration‐Based Structural Health Monitoring of Civil Structures

This article newly proposes the application of the stretching method, that is used in geophysics for detecting variations in the velocity with which waves propagate in the earth's crust from seismic noise recordings, in the context of vibration‐based Structural Health Monitoring (SHM) of civil structures. The result is a computationally efficient long‐term vibration‐based SHM tool, that follows the current trend of using a very limited number of sensors permanently installed on site to measure operational structural responses for the purpose of damage detection. In the SHM setting, the proposed method aims at a direct identification of small permanent shifts in the natural frequencies of the structure in a changing environment, which is achieved by maximizing the correlation coefficient between a reference waveform, computed in a training reference period in which the structure is assumed to be undamaged, and a stretched version of the same waveform evaluated at the current time. The comparison is performed in the frequency domain and the waveform of interest is obtained from cross‐correlations of the ambient vibration measurements. More specifically, in the case of multiple sensors, the waveform can be either the cross‐power spectral density of the signals recorded by a pair of sensors, or the largest singular value of the spectral matrix of the measurements. It follows that the method can be regarded as an extension of the classic Frequency Domain Decomposition (FDD). A key feature of the proposed stretching method is mitigating the effects of environmental fluctuations by time domain averaging of cross‐correlations over a proper period of time, before taking their Fourier transform to estimate the spectral densities. Such a time domain averaging is carried out in a relatively long period of time for estimating the reference waveform, whereas it is carried out in a shorter time for estimating the current waveform. The main features of the proposed methodology are its very low sensitivity to environmental fluctuations, resulting in a quite short training period length, and its low computational cost, which could be compatible with a direct integration within smart sensors with embedded electronics. The performance of the method is illustrated in the case study of an Italian historical monumental bell tower that has been monitored by the authors for more than 1 year.     

Tailoring the release rates of fluconazole using solid dispersions in polymer blends

Formulations of the drug Fluconazole with different release characteristics were prepared by dispersing the active pharmaceutical ingredient (API) in various polymeric carriers, and especially in polymer blends. Fluconazole was tested as a model drug with low solubility in water. First solid dispersions in pure polymers were studied. Use of pure polyvinylpyrrolidone (PVP) as carrier even for high drug load (30 wt%) resulted in rapid release. The drug release rates decreased by increasing the API content. The dissolution rate enhancement was attributed to drug amorphization, particle size reduction, and possible improvement of the drug wetting characteristics. Hydroxypropyl methylcellulose (HPMC) gave solid dispersions, from which the release rates of the drug varied from immediate to sustaining. As the drug amount increased, the rates became higher. Similar behavior also was found when Chitosan was used as carrier, with much more controlled rates close to those for sustained release. These differences were mainly attributed to the limited solubility and swelling of HPMC and Chitosan in aquatic media. To study the effectiveness of polymer blends in adjusting the release rates of the drug, solid dispersions in PVP/HPMC and PVP/Chitosan miscible blends were studied. The release rates of Fluconazole were adequately adjusted by differentiating the weight ratio of the polymers in the blends. PVP/HPMC blends with high PVP content can be used for immediate release formulations but PVP/Chitosan blends are inappropriate for such formulations and can only be used for controlled release.     

Small WEEE: determining recyclables and hazardous substances in plastics

The study of cementitious activity of chromium residue (CR) was carried out to formulate the properties of chromium residue-cement matrices (CRCM) by blending CR with Ordinary Portland Cement (OPC). The particle size distribution, microstructures of CR were investigated by some apparatuses, and physical properties, leaching behavior of hexavalent chromium [Cr(VI)] of CRCM were also determined by some experiments. Three types of commonly used superplasticizers (sulphonated acetone formaldehyde superplasticizer (J1), polycarboxylate-based superplasticizer (J2) and naphthalene superplasticizer (J3)) were chosen to investigate their influences on the physical properties and the Cr(VI)-immobilisation in the leachate of the CRCM hardened pastes. The results show that the CR has a certain cementitious activity. The incorporation of CR improves the pore size distribution of CRCM. The Cr(VI) concentrations in the leachate of CRCM significantly decrease by incorporation of J2. Among three superplasticizers, J2 achieves lowest Cr(VI) leaching ratio. Based on this study, it is likely to develop CR as a potential new additive used in cement-based materials.