Natural Compounds for Counteracting Nonalcoholic Fatty Liver Disease (NAFLD): Advantages and Limitations of the Suggested Candidates

The booming prevalence of nonalcoholic fatty liver disease (NAFLD) in adults and children will threaten the health system in the upcoming years. The “multiple hit” hypothesis is the currently accepted explanation of the complex etiology and pathophysiology of the disease. Some of the critical pathological events associated with the development of NAFLD are insulin resistance, steatosis, oxidative stress, inflammation, and fibrosis. Hence, attenuating these events may help prevent or delay the progression of NAFLD. Despite an increasing understanding of the mechanisms involved in NAFLD, no approved standard pharmacological treatment is available. The only currently recommended alternative relies on lifestyle modifications, including diet and physical activity. However, the lack of compliance is still hampering this approach. Thus, there is an evident need to characterize new therapeutic alternatives. Studies of food bioactive compounds became an attractive approach to overcome the reticence toward lifestyle changes. The present study aimed to review some of the reported compounds with beneficial properties in NAFLD; namely, coffee (and its components), tormentic acid, verbascoside, and silymarin. We provide details about their protective effects, their mechanism of action in ameliorating the critical pathological events involved in NAFLD, and their clinical applications.     

Biodegradable baked foam made with chayotextle starch mixed with plantain flour and wood fiber

New renewable materials are needed to reduce petroleum‐based plastic packaging. The effect of plantain flour (PF) and wood fiber (WF) on the properties of starch‐based foams (SBFs) were investigated. The SBFs were characterized using physical, thermal, and mechanical methods to better understand the relationship between PF and WF concentration. Contact angle values showed that the addition of WF or PF increased the hydrophobic character of the SBFs. Also, the addition of PF increased the heat transfer resistance and density of the foams, while their solubility decreased. The values of tensile strength and Young's modulus increased with increasing concentrations of PF in the SBFs. However, the addition of PF and WF promoted a decrease on the elongation at break of the SBFs. An increase in concentration of PF also showed a decrease in water vapor permeability, and an increase in the thickness of the cell wall layer of the SBFs. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45565.     

Polyurethane/acrylate hybrids: Effects of the acrylic content and thermal treatment on the polymer properties

Polyurethane (PU)/acrylate hybrids with different acrylic contents (10, 30, 50, 70, and 90 wt %) were prepared by the polymerization of acrylic monomers in the presence of preformed PU chains with polymerizable terminal vinyl groups. Films obtained by the casting of polymer dispersions before and after thermal annealing were characterized by dynamic light scattering, Fourier transform infrared spectroscopy, transmission electron microscopy (TEM), TEM electron energy‐loss spectroscopy, differential scanning calorimetry, and gel fraction determination. Small‐angle X‐ray scattering (SAXS), wide‐angle X‐ray scattering, mechanical properties testing, atomic force microscopy, water contact angle testing, Buchholz hardness testing, and roughness testing of the films were also performed. The effects of the acrylic content and thermal treatment on the structure and properties were determined. TEM showed that a core–shell morphology was formed during polymerization. When the acrylic content increased, smaller particles without core–shell morphologies were observed. TEM energy‐loss spectroscopy studies confirmed this observation. Systems with up to 50 wt % acrylic component were homogeneous, as determined by SAXS, before and after thermal annealing. An attempt to incorporate a higher amount of acrylic component led to phase‐separated materials with a different morphology and, therefore, different properties. The relationship between the acrylic content and properties did not follow linear behavior. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Monoliths as suitable catalysts for reverse‐flow combustors: Modeling and experimental validation

The performance of a bench‐scale monolithic reverse‐flow reactor (RFR) for methane combustion has been experimentally studied in this work. The influence of the different operating parameters, such as total gas flow rate (2.5 × 10^?4–5 × 10^?4 m³ s^?1 (STP)), methane inlet concentration (1000–5500 ppm), and switching time (300–900 s) on the reactor performance (outlet conversion and stability), has been experimentally determined. The validation of a heterogeneous one‐dimensional dynamic model for monolithic beds with the obtained experimental data allows the use of this model to simulate the behavior of industrial‐scale reactors. In the second part of the work, a systematic comparison of particulate and monolithic RFRs is carried out through design curves. Reactor length for 99% outlet conversion and the corresponding pressure drop is determined for varying operating conditions (surface velocity and inlet methane concentration). © 2010 American Institute of Chemical Engineers AIChE J, 2010     

Obtaining 1‐heptene from 1‐heptyne semihydrogenation with an anchored rhodium complex on different supports as catalyst

The complex [RhCl(NH₂(CH₂)₁₂CH₃)₃] was tested for the semihydrogenation of 1‐heptyne in homogeneous and heterogeneous conditions. γ‐Al₂O₃ and two different commercial activated carbons (RX‐3 EXTRA and GF‐45) were used as supports. The results were, then, compared with those previously reported for the [PdCl₂(NH₂(CH₂)₁₂CH₃)₂] complex supported or unsupported, and with the results obtained with the classic Lindlar catalyst. The complex was characterised by FTIR and elemental analysis. The pure species and the supported one were also characterised by X‐ray photoelectron spectroscopy. Results determined by the latter technique suggest that the active species is the complex itself, which is stable under the reaction conditions. The supported rhodium tetra‐coordinated complex shows higher activity and selectivity than the same complex unsupported, and also than the classic Lindlar catalyst. Moreover, among the rhodium‐supported complexes the one immobilised on RX‐3 EXTRA has a better performance than that heterogenised on GF‐45, and this one has a better activity and selectivity than the γ‐Al₂O₃ anchored complex. Our results also show that under the same operational conditions (temperature, hydrogen pressure and metal/substrate weight ratio) the rhodium complex, unsupported or supported, has a better performance than the corresponding palladium complex. Copyright © 2004 Society of Chemical Industry     

A Comparative Study of the 1-Hexene Hydroformylation Either Under Syngas Conditions or with Paraformaldehyde Catalyzed by Rhodium/Diphosphine Systems

In order to carry out a comparison, the hydroformylation of 1-hexene to their corresponding aldehydes (heptanal and 2-methyl-hexanal) was studied both under syngas conditions and with paraformaldehyde using the catalytic rhodium/diphosphine precatalysts; the catalytic systems were formed in situ by the addition of one or two equivalents of the corresponding diphosphine, Ph₂P(CH₂)_nPPh_2, n = 2 (dppe), 3 (dppp) and 4 (dppb), to the carbonyl complex Rh(acac)(CO)₂. For the hydroformylation reactions under syngas conditions, the more active systems were the ones containing one equivalent of the diphosphine, which produce trigonal bipyramidal species like RhH(CO)₂(diphos). The activity and selectivity of these systems strongly depend on the bite angle of the ligand: when the bite angle increases both parameters are higher (dppb > dppp > dppe). Contrary to these results, for the reaction with paraformaldehyde, the systems containing two equivalents of the diphosphine ligand, which produce the cationic square planar species [Rh (diphos)₂]⁺, were more active than those containing one equivalent; the reaction rate decreases with the enlargement of the carbon chain of the bridge between the two phosphorous atoms of the diphosphine (dppe > dppp > dppb). These results may be explained by a higher steric effect on the metal center, which probably produces a decreasing of the rate of the CH₂O oxidative addition reactions. For both reactions, these effects were explained through DFT calculations of the corresponding resting states.     

Liquid crystals ‘made of gold’

The simple linear coordination of gold(I) helps in the understanding of structure-property relationships in liquid crystals based on metal-containing molecules. This simple geometry also allows the preparation of materials showing a range of mesophases, based on both rod-like and disc-like molecules.     

Gold Nanoprisms as Optoacoustic Signal Nanoamplifiers for In Vivo Bioimaging of Gastrointestinal Cancers

Early detection of cancer greatly increases the chances of a simpler and more effective treatment. Traditional imaging techniques are often limited by shallow penetration, low sensitivity, low specificity, poor spatial resolution or the use of ionizing radiation. Hybrid modalities, like optoacoustic imaging, an emerging molecular imaging modality, contribute to improving most of these limitations. However, this imaging method is hindered by relatively low signal contrast. Here, gold nanoprisms (AuNPrs) are used as signal amplifiers in multispectral optoacoustic tomography (MSOT) to visualize gastrointestinal cancer. PEGylated AuNPrs are successfully internalized by HT‐29 gastrointestinal cancer cells in vitro. Moreover, the particles show good biocompatibility and exhibit a surface plasmon band centered at 830 nm, a suitable wavelength for optoacoustic imaging purposes. These findings extend well to an in vivo setting, in which mice are injected with PEGylated AuNPrs in order to visualize tumor angiogenesis in gastrointestinal cancer cells. Overall, both our in vitro and in vivo results show that PEGylated AuNPrs have the capacity to penetrate tumors and provide a high‐resolution signal amplifier for optoacoustic imaging. The combination of PEGylated AuNPrs and MSOT represents a significant advance for the in vivo imaging of cancers.     

High-Temperature Mechanical Behavior of Extruded Mg-Y-Zn Alloy Containing LPSO Phases

The high-temperature mechanical behavior of extruded Mg_97?3x Y_2x Zn _x (at. pct) alloys is evaluated from 473 K to 673 K (200 °C to 400 °C). The microstructure of the extruded alloys is characterized by Long Period Stacking Ordered structure (LPSO) elongated particles within the magnesium matrix. At low temperature and high strain rates, their creep behavior shows a high stress exponent (n = 11) and high activation energy. Alloys behave as a metal matrix composite where the magnesium matrix transfers part of its load to the LPSO phase. At high-temperature and/or low stresses, creep is controlled by nonbasal dislocation slip. At intermediate and high strain rates at 673 K (400 °C) and at intermediate strain rates between 623 K and 673 K (350 °C and 400 °C), the extruded alloys show superplastic deformation with elongations to failure higher than 200 pct. Cracking of coarse LPSO second-phase particles and their subsequent distribution in the magnesium matrix take place during superplastic deformation, preventing magnesium grain growth.     

Light harvesting photovoltaic mini‐generator

In this work, the design, fabrication and characterisation of a millimetre‐size photovoltaic (PV) energy source is described. The fabrication process is based on p‐type silicon‐on‐insulator wafers. It is shown that scaling up the number of cells from 9 to 169 makes the open‐circuit voltage to increase from 3.6 to 101.5 V with generated power densities ranging from 2.07 to 6.7 mW/cm² under 100 mW/cm² standard AM 1.5 Global Spectrum. A prototype consisting of a PV mini‐module connected to a mini‐battery has been assembled, modelled and characterised. The results show that the mini‐PV source can be used in low power applications. Copyright © 2011 John Wiley & Sons, Ltd.