Hepatic Δ9, Δ6, and Δ5 desaturations in non-insulin-dependent diabetes mellitus eSS rats

Both diabetes mellitus type 1 and diabetes mellitus type 2 are widespread diseases that alter carbohydrate and lipid metabolism. e Stilmann-Salgado (eSS) rats are experimental animals that spontaneously evolve to a state similar to that of young people affected by non-insulin-dependent diabetes mellitus (NIDDM; type 2). Using 6-mon-old eSS rats that, according to the literature [Martinez, S.M., Tarrés, M.C., Montenegro, S, Milo, R., Picena, J.C., Figueroa, N., and Rabasa, S.R. (1988) Spontaneous Diabetes in eSS Rats, Acta Diabetol. Lat. 25, 303–313], had already developed insulin resistance, we investigated the changes evoked on Δ9, Δ6, and Δ5 liver desaturases. The abundance of mRNA and enzymatic activities were measured, as well as the FA composition of liver microsomal lipids. Compared to control rats, the mRNA content and activity of SCD-1 (stearoyl CoA-desaturase, isoform of the Δ9 desaturase) were significantly higher, urase, isoform of the Δ9 desaturase) were significantly higher, whereas the mRNA and activities of Δ6 and Δ5 desaturases were not significantly modified. Correspondingly, the proportion of 18∶1n−9 and the ratios of 18∶1n−9/18∶0 and 16∶1/16∶0 in lipids were significantly increased, whereas the proportion of 20∶4n−6 was unaltered. These effects were found while glycemia was constant or increased. The results are completely opposite those described in insulin-dependent diabetes mellitus (type 1), in which a depression of all the desaturases is found. They suggest that in eSS rats, the activities of the desaturases were not modified by an insulin-resistance effect. Moreover, we suggest that the enhancement of SCD-1 activity might be considered as another typical sign of the NIDDM syndrome, because it has also been found in other animal models of NIDDM, for example, the ones evoked by the sucrose-rich diet and in the Zucker rat.     

Application of fracture mechanics for the characterization of poly(vinyl chloride) pipes. II. Evaluation of a ring-type specimen for fracture mechanics testing

An unplasticized poly(vinyl chloride) (U-PVC) pipe sample used in infrastructure applications in Brazil (nominal diameter DN 100, outside diameter 110 mm) was evaluated according to different fracture mechanics methodologies, including essential work of fracture (EWF) and other fracture toughness parameters such as the stress intensity factor and plane strain energy release rate . This pipe sample was also tested for the quality of processing (degree of gelation) via differential scanning calorimetry (DSC) and tensile strength. The comparative evaluation of different specimen configurations—curved specimens in three-point bending (CTPB) and full rings in tension (SNRT), in thicknesses varying from 5 to 30 mm, showed initial evidence of the suitability of ring-type specimens for the evaluation of EWF and . Results also indicate that the full ring geometry, at least in the present experimental setup, presents some drawbacks probably due to the storage of large amounts of elastic energy throughout the test. This fact leads to relevant deviations in both load–displacement behavior and results for strain energy release rate (), and the results found here will guide future research using full and split rings in different loading modes and improved experimental setups. It was also confirmed that the value of , determined by a modified Charpy test, is independent of the type of specimen tested, as long as the test mode and specimen width are the same. Both the experimental value of and the estimated value for the plane strain stress intensity factor () showed excellent agreement with values reported for other U-PVC compositions.     

Interactive Dynamics of Cell Volume and Cell Death in Human Erythrocytes Exposed to α-Hemolysin from Escherichia coli

α-hemolysin (HlyA) of E. coli binds irreversibly to human erythrocytes and induces cell swelling, ultimately leading to hemolysis. We characterized the mechanism involved in water transport induced by HlyA and analyzed how swelling and hemolysis might be coupled. Osmotic water permeability (P_f) was assessed by stopped-flow light scattering. Preincubation with HlyA strongly reduced P_f in control- and aquaporin 1-null red blood cells, although the relative P_f decrease was similar in both cell types. The dynamics of cell volume and hemolysis on RBCs was assessed by electrical impedance, light dispersion and hemoglobin release. Results show that HlyA induced erythrocyte swelling, which is enhanced by purinergic signaling, and is coupled to osmotic hemolysis. We propose a mathematical model of HlyA activity where the kinetics of cell volume and hemolysis in human erythrocytes depend on the flux of osmolytes across the membrane, and on the maximum volume that these cells can tolerate. Our results provide new insights for understanding signaling and cytotoxicity mediated by HlyA in erythrocytes.     

Dynamic analysis of thin-walled and variable open section beams with shear flexibility

The equations of motion of thin-walled beams with open cross-section, considering the effects of shear flexibility and rotatory inertia in the stress resultants, as well as variable cross-sectional properties are presented using a state variables approach. These equations are based on Vlasov's theory of thin-walled beams, which is modified to include the effects indicated above. The resulting equations are used in the determination of the natural frequencies of an open cross-section prestressed concrete beam. Comparisons with other formulations are also presented employing the waves dispersion equation.     

Targeting PIK3CA Actionable Mutations in the Circulome: A Proof of Concept in Metastatic Breast Cancer

The study of circulating cancer-derived components (circulome) is considered the new frontier of liquid biopsy. Despite the recognized role of circulome biomarkers, their comparative molecular profiling is not yet routine. In advanced breast cancer (BC), approximately 40% of hormone-receptor-positive, HER2-negative BC cases harbor druggable PIK3CA mutations suitable for combined alpelisib/fulvestrant treatment. This pilot study investigates PIK3CA mutations in circulating tumor DNA (ctDNA), tumor cells (CTCs), and extracellular vesicles (EVs) with the aim of determining which information on molecular targetable profiling could be recollected in each of them. The in-depth molecular analysis of four BC patients demonstrated, as a proof-of-concept study, that it is possible to retrieve mutational information in the three components. Patient-specific PIK3CA mutations were found in both tissue and ctDNA and in 3/4 cases, as well as in CTCs, in the classical population (large-sized CD45−/EpCAM+/− cells), and/or in the “non-conventional” sub-population (smaller-sized CD44+/EpCAM−/CD45− cells). Consistent mutational profiles of EVs with CTCs suggest that they may have been released by CTCs. This preliminary evidence on the molecular content of the different circulating biomaterials suggests their possible function as a mirror of the intrinsic heterogeneity of BC. Moreover, this study demonstrates, through mutational assessment, the tumor origin of the different CTC sub-populations sustaining the translational value of the circulome for a more comprehensive picture of the disease.     

Non-dissipative decoherence in Rabi oscillation experiments

Abstract

Decoherence may be due to the fluctuations of some classical variable or parameter of a system, and not only to the entanglement with the environment. Here we derive a model-independent formalism for this non-dissipative decoherence, which is then applied to describe the decoherence observed in some recent Rabi oscillation experiments.     

Multi-objective design and control of hybrid systems minimizing costs and unmet load

This paper presents, for the first time, the application of the strength Pareto evolutionary algorithm to the multi-objective design of isolated hybrid systems, minimising both the total cost throughout the useful life of the installation and the unmet load. For this task, a multi-objective evolutionary algorithm (MOEA) and a genetic algorithm (GA) have been used in order to find the best combinations of components for the hybrid system and control strategy. Also, a novel control strategy has been developed and it will be expounded in this article. As an example of application, a PV–wind–diesel system has been designed, obtaining a set of possible solutions (Pareto set) from which the designer can choose those which he/she prefers considering the costs and unmet load of each. The results obtained demonstrate the practical utility of the design method used.     

Evaluation of Different Sample Preparation Procedures Using Chemometrics: Comparison Among Photo-Fenton Reaction,Microwave Irradiation,and Direct Determination of Minerals in Fruit Juices

In this work, an exploratory study about the mineral characteristic of some fruit juice (passion fruit, pineapple, orange, and grape) applying chemometric tools was made. The juices analyzed were separated in different groups by principal components analysis and hierarchical components analysis in accordance with their minerals contents. Barium, C, Ca, K, Mg, Mn, Na, and Sr were determined by inductively coupled plasma optical emission spectrometry. Addition and recovery methods were used for confirmation of the results. The recovery range for microwave sample preparation was from 81% (for K) to 111% (for Mn), for photo-Fenton from 102% (for Ca e Mg) to 128% (for Na), and the direct analysis, without sample preparation step, from 96% (for K) to 139% (for Mn). A new method based on photo-Fenton reaction coupled with microwave radiation for juice decomposition was proposed; the obtained results were satisfactory and compatible with the conventional methods of analysis in accordance with Student’s statistic t test and chemometric tools.     

Design and economical analysis of hybrid PV–wind systems connected to the grid for the intermittent production of hydrogen

In this paper, several designs of hybrid PV–wind (photovoltaic–wind) systems connected to the electrical grid, including the intermittent production of hydrogen, are shown. The objective considered in the design is economical to maximise the net present value (NPV) of the system.