Nonlinear Absorption of Submicrometer Grain‐Size Cobalt‐Doped Magnesium Aluminate Transparent Ceramics

Transparent cobalt‐doped magnesium aluminate spinel (Co:MgAl₂O₄) ceramics with a submicrometer grain size were prepared by spark plasma sintering. For the first time, the nonlinear absorption of Co:MgAl₂O₄ transparent ceramics was experimentally demonstrated. Both ground state absorption (σ_GSA) and excited state absorption (σ_ESA) were estimated using the solid‐state slow saturable absorber model based on absorption saturation measurements performed at 1.535 μm. σ_GSA and σ_ESA for 0.03 at.% Co:MgAl₂O₄ were found to be 4.1 × 10^?19 cm² and 4.0 × 10^?20 cm², respectively. In the case of 0.06 at.% Co:MgAl₂O₄ ceramics, σ_GSA = 2.6 × 10^?19 cm² and σ_ESA= 5.3 × 10^?20 cm² were determined.     

Degradative transport of cationic amphiphilic drugs across phospholipid bilayers

Drug molecules must cross multiple cell membrane barriers to reach their site of action. We present evidence that one of the largest classes of pharmaceutical drug molecules, the cationic amphiphilic drugs (CADs), does so via a catalytic reaction that degrades the phospholipid fabric of the membrane. We find that CADs partition rapidly to the polar-apolar region of the membrane. At physiological pH, the protonated groups on the CAD catalyse the acid hydrolysis of the ester linkage present in the phospholipid chains, producing a fatty acid and a single-chain lipid. The single-chain lipids rapidly destabilize the membrane, causing membranous fragments to separate and diffuse away from the host. These membrane fragments carry the drug molecules with them. The entire process, from drug adsorption to drug release within micelles, occurs on a time-scale of seconds, compatible with in vivo drug diffusion rates. Given the rate at which the reaction occurs, it is probable that this process is a significant mechanism for drug transport.     

Novel conventional and chelating anion exchange resins with amino ligands for sorption of silver

ABSTRACT

The polymeric resins containing diethylenetriamine, tetraethylenepentamine, 2-(diethylamino)ethanol, 1-methylimidazole, and 1,2-dimethylimidazole ligands have been synthesized from vinylbenzyl chloride-divinylbenzene copolymers and used in the removal of Ag(I) from chloride solution. The best Ag(I) sorption was reached in the case of 1-methylimidazole resin. Resins retain their capacity towards Ag(I) in five consecutive sorption/desorption cycles. The resins with imidazole ligands were highly selective for Ag(I) from synthetic chloride solution and they did not sorb chloride complexes of Cu(II). Additionally, the recovery of Ag(I) was tested from real chloride solution coming from leaching of the copper concentrate from Lubin Concentrator (KGHM Polska Mied? S.A.).     

Identification of novel intergenic repetitive units in a mycobacterial two-component system operon

Mycobacterial interspersed repetitive units (MIRUs), a novel class of repeated sequences, were identified within the intercistronic region of an operon coding for a mycobacterial two-component system, named senX3-regX3. Southern blot analysis and homology searches revealed the presence of several homologous sequences in intergenic regions dispersed throughout the genomes of Mycobacterium bovis BCG, Mycobacterium tuberculosis and Mycobacterium leprae. These could be grouped into three major families, containing elements of 77-101 bp, 46-53 bp and 58-101 bp. Based on the available mycobacterial sequences, the total number of MIRUs is estimated to be about 40-50 per genome. Similar to previously identified small repetitive sequences, the MIRUs of the two-component operon are transcribed on a polycistronic mRNA. Unlike previously identified small repetitive sequences, however, MIRUs do not contain dyad symmetries, comprise small open reading frames (ORFs) whose extremities overlap those of the contiguous ORFs and are oriented in the same translational direction as those of the adjacent genes. Analyses of the sequences at the insertion sites suggest that MIRUs disseminate by transposition into DTGA sites involved in translational coupling in polycistronic operons.     

Label-Free Quantitative Proteomics Reveals Differences in Molecular Mechanism of Atherosclerosis Related and Non-Related to Chronic Kidney Disease

The major cause of mortality in patients with chronic kidney disease (CKD) is atherosclerosis related to traditional and non-traditional risk factors. However, the understanding of the molecular specificity that distinguishes the risk factors for classical cardiovascular disease (CVD) and CKD-related atherosclerosis (CKD-A) is far from complete. In this study we investigated the disease-related differences in the proteomes of patients with atherosclerosis related and non-related to CKD. Plasma collected from patients in various stages of CKD, CVD patients without symptoms of kidney dysfunction, and healthy volunteers (HVs), were analyzed by a coupled label-free and mass spectrometry approach. Dysregulated proteins were confirmed by an enzyme-linked immunosorbent assay (ELISA). All proteomic data were correlated with kidney disease development and were subjected to bioinformatics analysis. One hundred sixty-two differentially expressed proteins were identified. By directly comparing the plasma proteomes from HVs, CKD, and CVD patients in one study, we demonstrated that proteins involved in inflammation, blood coagulation, oxidative stress, vascular damage, and calcification process exhibited greater alterations in patients with atherosclerosis related with CKD. These data indicate that the above nontraditional risk factors are strongly specific for CKD-A and appear to be less essential for the development of “classical” CVD.     

Behavior of Cetyltrimethylammonium Bromide, tert-Octylphenol (9.5 EO) Ethoxylate and Ethanol Mixtures at the Water–Air Interface

The surface tension measurements of aqueous solutions of p‐(1,1,3,3‐tetramethylbutyl)phenoxypoly(9.5)ethylene glycol or tert‐octylphenol ethoxylate (TOP10) and cetyltrimethylammonium bromide (CTAB) mixtures with ethanol were carried out in the range of the total concentration of CTAB and TOP10 mixtures from 1 × 10^?7 to 1 × 10^?2 M and ethanol from 0 to 17.13 M. In the CTAB and TOP10 mixtures, the mole fractions of TOP10 were equal to 0.2; 0.4; 0.6; and 0.8, respectively. The results obtained were compared to those calculated from the Fainerman and Miller equation developed for ideal mixtures of two homologous surfactants, as well as from the Connors equation derived for the concentrated organic solutions. The calculations of the surface tension from the Fainerman and Miller equation were carried out treating the solvent and solute in a few different ways. The differences between the measured and calculated values of the surface tension were discussed in the light of molecular interaction parameter and the composition of the surface layer. The composition of the mixed surface layer at the solution‐air interface was evaluated according to Rosen using the nonideal solution theory with the assumption that water with ethanol is a mixed solvent. Knowing the values of mole fractions of CTAB and TOP10 in the surface layer, the molecular interaction parameter was determined.     

The effect of freezing on the hot air and microwave vacuum drying kinetics and texture of whole cranberries

Abstract

The aim of this study was to evaluate the effect of convective and cryogenic freezing, hot air convective drying (HACD) at 60, 70, 80, and 90?°C and microwave vacuum drying (MWVD) at 100, 150, 200, 300, 450, and 500?W on the drying kinetics and texture of whole cranberries. Effective moisture diffusivities and drying rates were higher, whereas drying times were shorter for the samples dried by MWVD compared with the samples processed by HACD. The drying kinetics of cranberries during MWVD was discussed based on the hypothesis postulating that changes in the drying rate of cranberries during MWVD can be explained by and correlated with changes in the pressure gradient on material surface. Cranberries processed by MWVD were characterized by significantly greater hardness, gumminess, and chewiness in comparison with HACD samples. MWVD was found to be an effective method for producing dried snacks characterized by hard and crispy texture and considerable resistance to stress associated with manufacturing, packaging, storage, and delivery. HACD produced brittle fruit that were difficult to store and transport and were not fully suitable for direct consumption. Convective freezing before MWVD improved the overall appearance of cranberries, whereas cryogenic freezing combined with high temperature HACD adversely influenced the drying rate and produced dried cranberries with suboptimal overall appearance.     

Regulated Necrosis in HeLa Cells Induced by ZnPc Photodynamic Treatment: A New Nuclear Morphology

Photodynamic therapy (PDT) is a cancer treatment modality based on the administration of a photosensitizer (PS), which accumulates preferentially in tumor cells. Subsequent irradiation of the neoplastic area triggers a cascade of photochemical reactions that leads to the formation of highly reactive oxygen species responsible for cell inactivation. Photodynamic treatments in vitro are performed with the PS, zinc-phthalocyanine (ZnPc). The PS is near the plasma membrane during uptake and internalization. Inactivation clearly occurs by a necrotic process, manifested by nuclear pyknosis, negative TUNEL and Annexin V assays and non-relocation of cytochrome c. In contrast, by increasing the incubation time, ZnPc is accumulated in the Golgi apparatus and produces cell inactivation with characteristics of apoptosis and necrosis: TUNEL positive, relocated cytochrome c and negative Annexin V assay. This type of death produces a still undescribed granulated nuclear morphology, which is different from that of necrosis or apoptosis. This morphology is inhibited by necrostatin-1, a specific inhibitor of regulated necrosis.     

Associations between Oil Yield and Profile of Fatty Acids,Sterols, Squalene,Carotenoids, and Tocopherols in Seed Oil of Selected Japanese Quince Genotypes during Fruit Development

Tocopherols, phytosterols, carotenoids, and squalene are present in mature seeds of Japanese quince. Yet, little is known about the relationship between these compounds and oil yield during fruit and seed development. The profile change of lipophilic compounds during fruit and seed development in Japanese quince cultivars “Darius,” “Rondo,” and “Rasa” is investigated. It is shown here that during fruit and seed development, there is a significant reduction, three‐ to over tenfold, in the concentration of minor bioactive compounds in seed oil. It is recorded that delay between synthesis of tocopherols and oil in Japanese quince seeds during the fruit development results in a logarithmic relationship between the oil content and tocopherols concentration in the seed oil (R² = 0.980). Similar trends are observed between oil yield and phytosterols, and carotenoids (R² = 0.927 and R² = 0.959, respectively). The profile of fatty acids during the development of the seeds significantly is changed. The reduction of linoleic, palmitic, and gondoic acids levels and increment of oleic acid is noted. The oil content, profile of fatty acids, and concentration of bioactive compounds in all three genotypes of Japanese quince do not change significantly statistically during the last month of fruit development. Practical Applications: Some fruits are harvested at different degrees of maturity mainly due to a logistic issue and uneven ripening of fruits, which affects the chemical composition of whole fruit including seeds. Therefore, it would be good to know how the chemical composition is changing in plant material during development especially in the last month before harvest. Production of Japanese quince continues to rise year to year and with it the volume of generated by‐products such as seeds. This study demonstrates how it changes the oil content, profile of fatty acid, and concentration of tocopherols, squalene, phytosterols, and carotenoids in the seeds and seed oil of three Japanese quince cultivars “Rondo,” “Darius,” and “Rasa” during plant development. The provided information can be very useful for the manufactories oriented on the processing of by‐products, mainly seeds, generated by other branches of industry, for instance, fruit‐processing.     

Electrochemical studies of carbon-rich polymer-derived SiCN ceramics as anode materials for lithium-ion batteries

The electrochemical behavior of poly(phenylvinylsilylcarbodiimide)-derived SiCN ceramics as anode material for lithium-ion batteries is reported here for the first time. The novel carbon-rich silicon carbonitride (SiCN) ceramics have been synthesized by the thermal treatment of poly(phenylvinylsilylcarbodiimide) under argon atmosphere at five temperatures, namely 1100, 1300, 1500, 1700 and 2000 °C. The SiCN electrodes were prepared without any conducting additives and were tested in electrochemical two electrodes cell using cyclic voltammetry and galvanostatic techniques. The capacity of the carbon-rich SiCN samples was found to be stable upon galvanostatic cycling and reaches almost 300 mAh/g for the sample prepared at 1300 °C with oxygen as the impurity. The dependence of the microstructure, especially of the crystallinity of the segregated carbon phase and of the oxygen impurities on the electrochemical behavior of the SiCN material, was analysed. At all temperatures of thermolysis, the free carbon phase has been identified as “soft carbon”.