Peripheral noxious stimulation induces CREM expression in dorsal horn: involvement of glutamate

Thermal washout curves have been proposed as noninvasive tools for analysing lower airway dimensions and pulmonary blood flow, but how upper airway heat transfer affects these washout curves is unclear. The present study was designed to compare extrathoracic and tracheobronchial contributions to thermal washout curves. Respiratory frequency, air ambient temperature, and body core temperature (tc) were varied in six male subjects before and after immersion in cold (1.1 degrees C) water for up to 2 h under three conditions: 1) control: ambient temperature (tamb) = 25 degrees C, rectal temperature change (delta tre) = 0 degrees C; 2) pre-immersion: tamb = 4 degrees C, delta tre = 0 degrees C; and 3) post-immersion: tamb = 25 degrees C, delta tre = -0.7 degrees C. Both peak expiratory nasal (tpn) and oral (tpo) airstream temperatures were measured. Each subject was tested twice. Expiratory tpo was generally higher than tpn in all conditions. Increasing breathing rates lowered tpn and tpo in the control and cold air environments. Orifice temperatures, which are presumed to reflect upper airway blood temperatures, correlated with both tpn and tpo. Lowering tc had no effect on washout curves during quiet breathing and affected only tpn during rapid breathing. The results suggest that while tracheobronchial conditions may contribute to thermal washout curves, extrathoracic conditions predominate. Strong correlations between orifice temperatures, peak expiratory nasal temperatures and peak expiratory oral temperature demonstrate the dominant role of upper airway heat exchange in determining thermal washout curves.     

Asynchronous privacy-preserving iterative computation on peer-to-peer networks

Privacy preserving algorithms allow several participants to compute a global function collaboratively without revealing local information to each other. Examples of applications include trust management, collaborative filtering, and ranking algorithms such as PageRank. Most solutions that can be proven to be privacy preserving theoretically are not appropriate for highly unreliable, large scale, distributed environments such as peer-to-peer (P2P) networks because they either require centralized components, or a high degree of synchronism among the participants. At the same time, in P2P networks privacy preservation is becoming a key requirement. Here, we propose an asynchronous privacy preserving communication layer for an important class of iterative computations in P2P networks, where each peer periodically computes a linear combination of data stored at its neighbors. Our algorithm tolerates realistic rates of message drop and delay, and node churn, and has a low communication overhead. We perform simulation experiments to compare our algorithm to related work. The problem we use as an example is power iteration (a method used to calculate the dominant eigenvector of a matrix), since eigenvector computation is at the core of several practical applications. We demonstrate that our novel algorithm also converges in the presence of realistic node churn, message drop rates and message delay, even when previous synchronized solutions are able to make almost no progress.     

Opc-fly ash cementitious systems: study of gel binders produced during alkaline hydration

In the present paper, experiments were performed on blended cements containing 30% Portland cement clinker and 70% fly ash. The powdery material was mixed with deionised water for “normal” hydration, and with two different alkaline solutions for “normal” alkaline activation. The mechanical strength developed by this highly blended cement differed significantly depending on the hydrating solution used. XRD, FTIR and ²⁹Si MAS-NMR characterisation studies were conducted to obtain information on the complex structural nature of the hardened matrices, which in all cases consisted of a mixture of amorphous gels (C-S-H + N-A-S-H gel). These highly blended cements are able to comply with the specifications defined in the European Standard EN-197-1:2000.     

Fully distributed authentication with locality exploitation for the CoDiP2P peer-to-peer computing platform

CodiP2P is a distributed platform for computation based on the peer-to-peer paradigm. This article presents a novel distributed authentication method that suits the platform and adapts to its characteristics. The developed method is based on the Web of Trust paradigm, i.e., not depending on a traditional PKI infrastructure, and focuses on efficiency both in the number of messages transmitted and digital signatures processed by exploiting the inherent locality found in the platform. As part of the method, a reliable and efficient distributed public key repository is developed taking CoDiP2P’s de Bruijn topology as a cornerstone.     

Removing interference components in time–frequency representations using morphological operators

Time–frequency representations have been of great interest in the analysis and classification of non-stationary signals. The use of highly selective transformation techniques is a valuable tool for obtaining accurate information for studies of this type. The Wigner-Ville distribution has high time and frequency selectivity in addition to meeting some interesting mathematical properties. However, due to the bi-linearity of the transform, interference terms emerge when the transform is applied over multi-component signals. In this paper, we propose a technique to remove cross-components from the Wigner-Ville transform using image processing algorithms. The proposed method exploits the advantages of non-linear morphological filters, using a spectrogram to obtain an adequate marker for the morphological processing of the Wigner-Ville transform. Unlike traditional smoothing techniques, this algorithm provides cross-term attenuations while preserving time–frequency resolutions. Moreover, it could also be applied to distributions with different interference geometries. The method has been applied to a set of different time–frequency transforms, with promising results.     

Influence of Drying Temperature and Harvesting Season on Phenolic Content and Antioxidant and Antiproliferative Activities of Olive (Olea europaea) Leaf Extracts

Interest in plant compounds has increased, given recent evidence regarding their role in human health due to their pleiotropic effects. For example, plant bioactive compounds present in food products, including polyphenols, are associated with preventive effects in various diseases, such as cancer or inflammation. Breast and colorectal cancers are among the most commonly diagnosed cancers globally. Although appreciable advances have been made in treatments, new therapeutic approaches are still needed. Thus, in this study, up to 28 olive leaf extracts were obtained during different seasons and using different drying temperatures. The influence of these conditions on total polyphenolic content (measured using Folin–Ciocalteu assays), antioxidant activity (using Trolox Equivalent Antioxidant Capacity and Ferric Reducing Ability of Plasma assays) and antiproliferative capacity (using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, MTT assays) was tested in breast and colorectal cancer cells. Increased phenolic composition and antioxidant and antiproliferative capacity are noted in the extracts obtained from leaves harvested in autumn, followed by summer, spring and winter. Regarding drying conditions, although there is not a general trend, conditions using the highest temperatures lead to the optimal phenolic content and antioxidant and antiproliferative activities in most cases. These results confirm previously published studies and provide evidence in support of the influence of both harvesting and drying conditions on the biological activity of olive leaf extracts.     

Conjugated Porous Polymers Based on BODIPY and BOPHY Dyes in Hybrid Heterojunctions for Artificial Photosynthesis

Developing highly efficient photocatalysts for artificial photosynthesis is one of the grand challenges in solar energy conversion. Among advanced photoactive materials, conjugated porous polymers (CPPs) possess a powerful combination of high surface areas, intrinsic porosity, cross-linked nature, and fully π-conjugated electronic systems. Here, based on these fascinating properties, organic–inorganic hybrid heterostructures composed of CPPs and TiO₂ for the photocatalytic CO₂ reduction and H₂ evolution from water are developed. The study is focused on CPPs based on the boron dipyrromethene (BODIPY) and boron pyrrol hydrazine (BOPHY) families of compounds. It is shown that hybrid photocatalysts are active for the conversion of CO₂ mainly into CH₄ and CO, with CH₄ production 4 times over the benchmark TiO₂. Hydrogen evolution from water surpassed by 37.9-times that of TiO₂, reaching 200 mmol g_cat⁻¹ and photonic efficiency of 20.4% in the presence of Pt co-catalyst (1 wt% Pt). Advanced photophysical studies, based on time-resolved photoluminescence and transient absorption spectroscopy, reveal the creation of a type II heterojunction in the hybrids. The unique interfacial interaction between CPPs and TiO₂ results in longer carriers’ lifetimes and a higher driving force for electron transfer, opening the door to a new generation of photocatalysts for artificial photosynthesis.