Explorative investigation of the anti-glycative effect of a rapeseed by-product extract

Formation of Advanced Glycation End-products (AGEs) in biological systems are increased during hyperglycaemia due to higher levels of circulating glucose, as well as carbonyl reactive species. AGEs are causative factors of common chronic diseases. Since synthetic AGE-inhibitors exert unwanted side effects and polyphenols act as potent antiglycative agents, vegetables (fruits, seeds and related by-products) are good candidates for searching natural inhibitors. The aim of this research is to explore the suitability of a polyphenol-rich rapeseed cake extract (RCext) to decrease the formation of AGEs in an in vitro model. Total Phenolic Content, antioxidant, anti-glycative activity, specific inhibition of AGEs (pentosidine and argypyrimidine), and methylglyoxal trapping capacity of the RCext were evaluated. The metabolomic profile of the extract was also analysed through GC-MS. Different phenols, amino acids, carbohydrates, organic acids and fatty acids are identified in the RCE by GC-MS. Results confirm the high concentration of polyphenols correlated with the antioxidant capacity and anti-glycative activity in a dose dependent manner. Rapeseed cake extract (3.7 mg mL−1) significantly reduced the formation of free fluorescent AGEs and pentosidine up to 34.85%. The anti-glycative activity of the extract is likely to be due to the high concentration of sinapinic acid in its metabolic profile, and the mechanism of action is mediated by methylglyoxal trapping. Results show a promising potential for using rapeseed cake extract as a food supplement to ameliorate the formation of AGEs. Rapeseed cake extract should therefore be considered a potential candidate for the prevention of glycation-associated complications of age-related pathologie

Electrochemical assessment of pigments-binding medium interactions in oil paint deterioration: a case study on indigo and Prussian blue

Abstract The degradation of laboratory oil paint film specimens containing indigo and Prussian blue pigments and pictorial samples from the Sant Francesc de Paula painting exhibited in the Tomàs Balvey Arxiu Museum (Cardedeu (Catalonia), Spain) has been studied by voltammetry of immobilized particles. This technique, combined with light microscopy, scanning electron microscopy-energy dispersive X-ray analysis, nanoindentation-atomic force microscopy, attenuated total reflectance-Fourier-transform infrared spectroscopy and gas chromatography–mass spectroscopy techniques permits the proposal of a dual scheme for the degradation of the pigments when naturally aged and submitted to accelerated UVA aging. Under conditions of moderate temperature, humidity and natural illumination, and low gradients of these parameters, Prussian blue acts as a radical scavenger moderating the production of reactive oxygen species produced in the oil binding medium by the action of ultraviolet radiation, resulting in the formation, in the solid state, of the solid-solution, {KFeIII[FeII(CN)6]} x {FeIII[FeIII(CN)6]}1–x , known as Berlin green, which then promotes the formation of indigo adducts with radicals. In several localized areas of the Sant Francesc de Paula paint showing strong degradation, Prussian blue acts as a promoter of the indigo oxidation to isatin, thus resulting in a considerable chromatic shift

Diffusionless Transition in Tricosane and Reversible Inhibition of Calcium Oxalate Monohydrate: Two Studies of Crystal Growth

The process of crystal growth has been intensively studied, for both its academic interest and industrial importance. I report here two studies of crystal growth. The normal alkanes are an interesting, both in terms of their intrinsic properties and because many biological materials contain hydrocarbon domains. The normal alkanes often exhibit complicated phase behaviour, with phase diagrams containing multiple solid phases. We report here a curious pattern of twinned domains seen in one phase of tricosane (C23H48), which we have studied by X-ray diffraction, as well as by optical and atomic force microscopy. This pattern is seen in the rotator RV phase, a monoclinic arrangement of tricosane molecules without orientational order. Transitions between this polymorph and the orthorhombic phase lying at higher temperatures preserve features at the molecular level, and thus represent a diffusionless, martensitic-like transformation. Calcium oxalate monohydrate (COM) is the primary constituent of most kidney stones. Certain proteins, such as osteopontin (OPN), inhibit stone formation. The inhibition of crystallization due to adsorbed impurities is usually explained in terms of a model proposed in 1958 by Cabrera and Vermilyea, which hypothesizes that impurities adsorb to growth faces and pin growth steps, thus impeding their progress via the Gibbs-Thomson effect. To determine the role of OPN in the biomineralization of kidney stones, crystal growth on the {010} face of COM was examined in real time by atomic force microscopy in the presence of a synthetic peptide. We observed clear changes in the morphology of the growth-step structure and a decrease in step velocity upon addition of inhibitors, suggesting adsorption on the {010} growth hillocks. Experiments in which inhibitors were replaced in the growth cell by a supersaturated solution showed that COM hillocks are able to fully recover to their pre-inhibited state. Our results suggest that recovery occurs through incorporation of the peptide into the growing crystal, rather than by, e.g., desorption from the growth face. This work provides new insights into the mechanism by which crystal growth is inhibited, with important implications for the design of therapeutic agents for kidney stone disease and other forms of pathological calcification

Integrating Voice over IP Solution in IPv6 and IPv4 Networks to Increase Employee Productivity: A Case Study of Cameroon Telecommunications (Camtel), North-West

Telecommunications organizations have to follow the rapid innovation of technology if they want to face challenges raised by competition. The challenge to respond to the huge market demand of updated products and services from customers requires that the organization‘s working environment be equipped with tools and communication facilities that contribute to ameliorating productivity. Cameroon Telecommunications (Camtel) is facing a digital telephony and Internet Protocol strategic management challenge. Successful implementation cannot be achieved if the employees are still depending on the ageing public switched telephone network (PSTN) as their primary communication system, despite the frequent loss of dial tone experience in a day which can last up to a week, with serious repercussions on business activities and revenues. This study is designed to provide a solution to the telecommunications challenge. The fundamental question is how to integrate a digital telephony system that will provide telephony services in the existing IPv4 data network while prioritizing IPv6 traffic forwarding. This study proposes and implements solutions that integrate a Voice over IP solution with IPv6 as an alternative communication system that relies on the existing IPv4 data network. VoIP is deemed as one of the driving forces behind the adoption of IPv6. The purpose is to offer to workers an option that will free them from the poor Quality of Service (QoS) of their existing PSTN based solution, hopefully enhancing the overall productivity. This paper follows two research methodologies: Qualitative Research in Applied Situations and Engineering design process. The first part of this study reports the results of the evaluation of how much such a solution can enhance workers’ productivity. As it is important to provide an environment where IPv4 and IPv6 networks and applications/devices can interoperate in the context of VoIP; the second part describes practically a simulation environment where various configurations of network entities are done following a Dual-Stack transition approach. Document and records were used to gather information related to the structure, operations, and topological update of the Camtel’s existing IP data network. The findings demonstrated that VoIP can be an effective communication solution for Camtel and its implementation with IPv6 will be preferable. However, for this to be efficient there must be a provision of sufficient bandwidth and usage of types of equipment and transmission mediums that minimizes processing and propagation delays. Findings also reveal that better productivity will be achieved if workers are fully trained for the exploitation. This research article tries to highlight, discuss a required transition roadmap and extend the local knowledge and practice on IPv6. Future expansion of this research work will consist of deploying Dual-Stack VoIP in the remaining 9 regional offices for full integration in the corporate communication system of Camtel

Structure and composition dynamics of single-crystal copper interfaces and Fe-Ag and Fe-Cu nanoparticles

For heterogeneous (electro)catalysis, the catalytic properties of a material are foremost determined by its structure and composition at the interface between the catalyst and the reaction environment. However, both the structure and composition are not static factors, but parameters that respond dynamically to their environment. A deeper understanding of these dynamic processes is therefore required to be able to, in turn, make targeted improvements to electrocatalytic materials. Here, three projects are presented that each address the surface alterations that result from specific catalyst functionalization and activation treatments. First, we show the oxidation of Cu(100) and Cu(111) surfaces via a low-pressure O2-plasma treatment, investigated by scanning tunneling microscopy, x-ray spectroscopy and low energy electron diffraction. We traced the evolution of Cu, Cu2O and CuO and the surface structure over time and found that the surface orientation plays a critical role in the time-dependent oxidation process. The results show that initial surface reconstruction is accompanied by island growth, coalescencing into a thin layer for longer exposure times. The composition trace reveals an initial Cu2O overlayer until eventually a thicker CuO is grown on top of it. The second study investigates the effects of a pulsed potential on the surface morphology of a Cu(100) single crystal. The stepped surface of a UHV-prepared crystal experiences large alterations in the form of cubic protrusions evolving during the pulsed potential in a certain potential window, resulting in a reconstructed surface and highly reactive structural motifs. We also identified key potentials and pulse durations and their corresponding structural changes to allow for separation of morphological from oxidation state effects in future studies. In the final project, nuclear resonant inelastic X-ray scattering (NRIXS) and X-ray absorption fine-structure spectroscopy (XAFS) measurements were employed to gain insight into the dynamic structure and surface composition of FeCu and FeAg nanoparticles under CO2RR conditions. We also extracted their correlations with the catalytic activity and selectivity. The formation of a core-shell structure during CO2RR for FeAg NP was inferred from the phonon density of states (PDOS), extracted from NRIXS data, and XAFS measurements

Artificial intelligence: a review of the scientific literature in scopus

Artificial intelligence (AI) has revolutionized conventional work methods in all areas of knowledge. The aim of this study is to analyze the current state of research in this field. To this end, a systematic review was carried out with a bibliometric approach that included analysis of the distribution of scientific production by year, the most relevant sources, Bradford's Law to identify the main sources, the most prominent authors, Lotka's Law to analyze the productivity of authors and the author's "h" index. Through the review of the scientific literature available in the Scopus database, 609 relevant results were identified, of which 414 were articles in Spanish. A total of 205 articles were selected as the final publication of the study and 113 of them were open access. The empirical studies demonstrate that AI presents both opportunities and ethical and social challenges, especially in areas such as health, communication, law and artistic practices. In healthcare, AI can improve patients' quality of life. In journalism, AI streamlines the production of objective news and helps reduce misinformation, although it also poses ethical and professional challenges. In the field of law, AI offers opportunities to improve efficiency in judicial decision-making and legal work, but it also brings ethical and legal considerations. It is therefore essential to strike a balance between harnessing the benefits of AI and protecting rights, privacy and ethics in each of these fields, in order to maximize its potential for the benefit of society

Bifurcation scenarios, dynamical integrity and control of noncontact atomic force microscopes

The research focuses on the description of the global dynamical behavior of a reduced-order model of noncontact Atomic Force Microscope. Different numerical analyses and continuation techniques are carried out to investigate the evolution of the main system periodic solutions and relevant basins of attraction under variations of the most significant system parameters. Local bifurcations, stability boundaries and basin erosion processes around primary and subharmonic resonance regions are studied in presence of both the parametrical horizontal excitation and the external one, and the obtained behavior charts are used not only to compare the results with the literature ones, but also as practical instruments to characterize the operation ranges in terms of the selected parameters. With the same perspective, dynamical integrity concepts, such as detection of basins of attraction, and quantification of their erosion process via integrity measures, are applied to determine acceptable frequency-dependent thresholds associated with a priori safe design targets. Furthermore, an external feedback control is introduced with the aim to take the system response to a selected reference one, thus providing a simple and efficient method to avoid possible unstable motions. Upon checking the effectiveness of the procedure in the weakly nonlinear regime via a perturbation approach, several numerical analyses in the strongly nonlinear regime are accomplished to achieve a description of its dynamical behavior as a function of the newly inserted parameters, and to critically evaluate the effectiveness of the control actuation on the system dynamics, with also a view to the overall response scenario

Influence of Effective Modulus on Period-Doubling Bifurcation in Atomic Force Microscopy: Investigation and Implementation for Sample Characterization

Atomic force microscope (AFM) is an important tool for measuring the topographical and other properties of a sample with nanometer resolution. The cantilever probe of the AFM is influenced by nonlinear interaction forces which act between the probe and the sample. For certain non-standard excitation conditions, this can result in bifurcations in the probe's response. This work numerically examines a period-doubling bifurcation observed to occur for interactions with soft materials. The influence of the sample properties and other conditions on the bifurcation is studied and a method is proposed for sample material characterization. The identified values from simulated 1-D and 2-D scans agree well with the true values. The proposed method does not require the use of special probes and it uses the control algorithm for traditional tapping mode AFM with minor modification. This proposed method could also achieve high scan speeds and prevent strong, destructive interaction forces