Optical and electrical properties of colloidal (spherical Au)-(spinel ferrite nanorod) heterostructures

We report here a simple synthetic route to Au-Fe(x)O(y) heterostructures in which spinel ferrite (Fe(x)O(y)) grows as a nanorod on a spherical gold (Au) seed. The large red shift in the plasmon resonance in the heterostructures could be explained by a dielectric effect (although we could not entirely exclude a contribution due to electron transfer from Au to defect states at the Au-Fe(x)O(y) interface), while the magnetic properties of the Au-Fe(x)O(y) heterostructures were basically the same as those of the corresponding nanocrystals after Au leaching. In films of Au-Fe(x)O(y) heterostructures the electrical conductivity appeared to be mediated by the Au domains.     

Near-Infrared Dyes: Towards Broad-Spectrum Antivirals

Broad antiviral activity in vitro is known for many organic photosensitizers generating reactive oxygen species under irradiation with visible light. Low tissue penetration of visible light prevents further development of antiviral therapeutics based on these compounds. One possible solution to this problem is the development of photosensitizers with near-infrared absorption (NIR dyes). These compounds found diverse applications in the photodynamic therapy of tumors and bacterial infections, but they are scarcely mentioned as antivirals. In this account, we aimed to evaluate the therapeutic prospects of various NIR-absorbing and singlet oxygen-generating chromophores for the development of broad-spectrum photosensitizing antivirals.     

Distinct Effects of Beta-Amyloid,Its Isomerized and Phosphorylated Forms on the Redox Status and Mitochondrial Functioning of the Blood–Brain Barrier Endothelium

The Alzheimer’s disease (AD)-associated breakdown of the blood–brain barrier (BBB) promotes the accumulation of beta-amyloid peptide (Aβ) in the brain as the BBB cells provide Aβ transport from the brain parenchyma to the blood, and vice versa. The breakdown of the BBB during AD may be caused by the emergence of blood-borne Aβ pathogenic forms, such as structurally and chemically modified Aβ species; their effect on the BBB cells has not yet been studied. Here, we report that the effects of Aβ₄₂, Aβ₄₂, containing isomerized Asp7 residue (iso-Aβ₄₂) or phosphorylated Ser8 residue (p-Aβ₄₂) on the mitochondrial potential and respiration are closely related to the redox status changes in the mouse brain endothelial cells bEnd.3. Aβ₄₂ and iso-Aβ₄₂ cause a significant increase in nitric oxide, reactive oxygen species, glutathione, cytosolic calcium and the mitochondrial potential after 4 h of incubation. P-Aβ₄₂ either does not affect or its effect develops after 24 h of incubation. Aβ₄₂ and iso-Aβ₄₂ activate mitochondrial respiration compared to p-Aβ₄₂. The isomerized form promotes a greater cytotoxicity and mitochondrial dysfunction, causing maximum oxidative stress. Thus, Aβ₄₂, p-Aβ₄₂ and iso-Aβ₄₂ isoforms differently affect the BBBs’ cell redox parameters, significantly modulating the functioning of the mitochondria. The changes in the level of modified Aβ forms can contribute to the BBBs’ breakdown during AD.     

CrossTORC and WNTegration in Disease: Focus on Lymphangioleiomyomatosis

The mechanistic target of rapamycin (mTOR) and wingless-related integration site (Wnt) signal transduction networks are evolutionarily conserved mammalian growth and cellular development networks. Most cells express many of the proteins in both pathways, and this review will briefly describe only the key proteins and their intra- and extracellular crosstalk. These complex interactions will be discussed in relation to cancer development, drug resistance, and stem cell exhaustion. This review will also highlight the tumor-suppressive tuberous sclerosis complex (TSC) mutated, mTOR-hyperactive lung disease of women, lymphangioleiomyomatosis (LAM). We will summarize recent advances in the targeting of these pathways by monotherapy or combination therapy, as well as future potential treatments.     

Dynamic mechanical analysis of ethylene/1‐hexene copolymers: The effect of the catalyst type on the short‐chain branching distribution and properties of the amorphous and crystalline phases

Dynamic mechanical analysis was used to study ethylene/1‐hexene copolymers with different compositions, molecular weight distributions, and profiles of short‐chain branching (SCB) versus molecular weight. These copolymers were produced over a highly active supported titanium–magnesium catalyst (TMC), a highly active supported vanadium–magnesium catalysts (VMC), and a supported zirconocene catalyst. A higher fraction of the crystalline phase in the copolymers prepared with VMC was shown to result in higher elastic modulus values. β relaxation was found to be sensitive to the SCB distribution versus the molecular weight. The copolymers prepared with the zirconocene catalyst and VMC were characterized by more uniform SCB distributions and higher temperatures of β relaxation compared to the copolymers prepared with TMC. The mobility of the polymer chains at room temperature in the amorphous phase obtained by the spin‐probe method rose with increasing branch content in the copolymers and was not sensitive to different SCB distribution profiles. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44638.     

Design,Synthesis, and Biological Evaluation of (+)-Camphor- and (−)-Fenchone-Based Derivatives as Potent Orthopoxvirus Inhibitors

In this work, a library of (+)-camphor and (−)-fenchone based N-acylhydrazones, amides, and esters, including para-substituted aromatic/hetaromatic/cyclohexane ring was synthesized, with potent orthopoxvirus inhibitors identified among them. Investigations of the structure-activity relationship revealed the significance of the substituent at the para-position of the aromatic ring. Also, the nature of the linker between a hydrophobic moiety and aromatic ring was clarified. Derivatives with p-Cl, p-Br, p-CF_3, and p-NO₂ substituted aromatic ring and derivatives with cyclohexane ring showed the highest antiviral activity against vaccinia virus, cowpox, and ectromelia virus. The hydrazone and the amide group were more favourable as a linker for antiviral activity than the ester group. Compounds 3 b and 7 e with high antiviral activity were examined using the time-of-addition assay and molecular docking study. The results revealed the tested compounds to inhibit the late processes of the orthopoxvirus replication cycle and the p37 viral protein to be a possible biological target.     

Comparative analysis of catalyst operation in the process of higher paraffins dehydrogenation at different technological modes using mathematical model

Abstract

This paper presents the results of comparative analysis of three run cycles of platinum catalyst for higher paraffins C₉–C₁₄ dehydrogenation process, performed using mathematical model. The results of model calculations were compared with the experimental data obtained at the industrial unit. It was established that deactivation of the platinum dehydrogenation catalyst is influenced by the technological modes of its operation, such as temperature, pressure, hydrogen/feedstock molar ratio and water supply. In the process of higher paraffins dehydrogenation, the phenomenon of platinum catalyst self-regeneration is observed. This occurs due to the action of feedstock components, in particular water and hydrogen involved in oxidation and hydrogenation of intermediate condensation products (coke structures). Model calculations showed that with a decrease in the hydrogen/feedstock molar ratio and simultaneous increase in water supply, depending on the temperature and composition of feedstock, it is possible to slow down deactivation process and increase the catalyst service life. This fact was experimentally confirmed at industrial unit.     

Comparison of Polyunsaturated Fatty Acids Content in Filets of Anadromous and Landlocked Sockeye Salmon Oncorhynchus Nerka

Abstract: Fatty acid composition and content of 2 forms of sockeye salmon Oncorhynchus nerka from lakes in Kamchatka Peninsula (Russia) were compared. One form of sockeye salmon was anadromous (“marine”), that is, adult fish migrated in ocean to feed and grow and than return in the lake to breed. Fish of another form, kokanee, never migrate in the ocean. Per cent levels of the main indicators of nutritive value, eicosapentaenoic acid (EPA, 20:5n‐3), and docosahexaenoic acid (DHA, 22:6n‐3), were significantly higher in the landlocked O. nerka. However, concentrations of EPA and DHA per wet weight of filets were higher in the marine form, because of the relatively higher content of sum of fatty acids in their muscle tissue. As concluded, fish fed in marine environment had higher contents of long‐chain n‐3 fatty acids per wet weight than fish of the same species, fed in fresh waters. In general, both the anadromous sockeye salmon and the landlocked kokanee salmon can be recommended for human diet as a valuable product concerning contents of EPA and DHA. Practical Application: The long‐chain polyunsaturated acids (PUFA) have been specifically recommended for humans to prevent cardiovascular disease and psychiatric disorders. Fish are known to be the main source of PUFA in human diet. Data on PUFA content in diverse food fish is essential to compare the benefits they offer for consumers’ health. We compared PUFA contents in 2 forms of popular food fish Oncorhynchus nerka, migrating sockeye salmon and landlocked kokanee salmon, and found that both forms are valuable product concerning PUFA content.     

Metal‐Free Efficient,General and Facile Iododecarboxylation Method with Biodegradable Co‐Products

The development of a novel, efficient and robust method for the general conversion of aliphatic and aromatic carboxylic acids to organic iodides without the use of heavy metals or strong oxidizing agents is reported. Commercially available N‐iodoamides were used for both initiation and halogen donation under irradiative conditions. Isolation of the product is extremely simple and the major co‐product is removed as a water‐soluble biodegradable material.     

Plasmon dynamics in colloidal Cu₂-xSe nanocrystals

The optical response of metallic nanostructures after intense excitation with femtosecond-laser pulses has recently attracted increasing attention: such response is dominated by ultrafast electron-phonon coupling and offers the possibility to achieve optical modulation with unprecedented terahertz bandwidth. In addition to noble metal nanoparticles, efforts have been made in recent years to synthesize heavily doped semiconductor nanocrystals so as to achieve a plasmonic behavior with spectrally tunable features. In this work, we studied the dynamics of the localized plasmon resonance exhibited by colloidal Cu(2-x)Se nanocrystals of 13 nm in diameter and with x around 0.15, upon excitation by ultrafast laser pulses via pump-probe experiments in the near-infrared, with ～200 fs resolution time. The experimental results were interpreted according to the two-temperature model and revealed the existence of strong nonlinearities in the plasmonic absorption due to the much lower carrier density of Cu(2-x)Se compared to noble metals, which led to ultrafast control of the probe signal with modulation depth exceeding 40% in transmission.