Spectral Stokesmeter. 1. Implementation of the device

We describe a spectral Stokesmeter: a device for fast simultaneous measurement of the four Stokes parameters of light. It consists of an original optical part, a four-channel scanning optoelectronic system, and a controlling computer system. The original optical scheme was first proposed by us. It is based on two holographic gratings, one of which is a special type of polarization grating. It allows an easy calibration of the device comprising wavelength and sensitivity calibration. The spectral range of the present implementation of the spectral Stokesmeter is 520-750 nm, and the error in the measurement of the normalized Stokes parameters is < or = 0.05.     

Structure and catalytic properties of Co/ porcelain in the synthesis of 2,3‐dihydrofuran

The cyclodehydration of 1,4‐butanediol over cobalt catalysts in the liquid phase is used for the production of 2,3‐dihydrofuran. The catalyst preparation parameters considered were the metal loading, precipitation pH and reduction temperature of cobalt salt. It was found that the use of Co(NO₃)₂ together with Na₂CO₃ in a 1:1 ratio yielded better catalysts. Under the conditions used in this study the optimum cobalt loading for the selective production of 2,3‐dihydrofuran is in the range 15–50 wt%. The optimum reduction temperature of Co/porcelain catalyst depends on cobalt loading. The optimum reduction temperatures for 15 and 50 wt% cobalt loading are 773 and 723 K (reduction time 20 min), respectively. © 2001 Society of Chemical Industry     

Accumulation of dysprosium,samarium, terbium,lanthanum, neodymium and ytterbium by Arthrospira platensis and their effects on biomass biochemical composition

The growth of Arthrospira platensis and physiological changes in biomass under the effects of six rare earth elements Dy, Sm, Tb, La, Nd and Yb were evaluated. Elements were tested by three concentrations of 10, 20 and 30 mg/L. According to neutron activation analysis data A. platensis's accumulation capacity toward studied elements changes in the following order of La > Dy > Nd > Sm > Yb > Tb. The results show that Dy and La ions stimulate biomass growth and Yb ions inhibit it, while Sm, Tb and Nd ions do not affect biomass accumulation. The contents of proteins and chlorophyll a are not affected by the presence of rare earth elements in the cultivation medium. Studied elements affect to different extents carbohydrates, phycobilins, β-carotene, lipids and MDA contents in spirulina biomass. Changes in the antioxidant activity under applied metal loads reveal a moderate stress in exposed A. platensis. Cyanobacterium A. platensis can be successfully used for bioremediation of natural water contaminated with REEs as well as REEs recovery from low polluted industrial effluents.     

Inhaled Placental Mesenchymal Stromal Cell Secretome from Two- and Three-Dimensional Cell Cultures Promotes Survival and Regeneration in Acute Lung Injury Model in Mice

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) is a common clinical problem, leading to significant morbidity and mortality, and no effective pharmacotherapy exists. The problem of ARDS causing mortality became more apparent during the COVID-19 pandemic. Biotherapeutic products containing multipotent mesenchymal stromal cell (MMSC) secretome may provide a new therapeutic paradigm for human healthcare due to their immunomodulating and regenerative abilities. The content and regenerative capacity of the secretome depends on cell origin and type of cultivation (two- or three-dimensional (2D/3D)). In this study, we investigated the proteomic profile of the secretome from 2D- and 3D-cultured placental MMSC and lung fibroblasts (LFBs) and the effect of inhalation of freeze-dried secretome on survival, lung inflammation, lung tissue regeneration, fibrin deposition in a lethal ALI model in mice. We found that three inhaled administrations of freeze-dried secretome from 2D- and 3D-cultured placental MMSC and LFB protected mice from death, restored the histological structure of damaged lungs, and decreased fibrin deposition. At the same time, 3D MMSC secretome exhibited a more pronounced trend in lung recovery than 2D MMSC and LFB-derived secretome in some measures. Taking together, these studies show that inhalation of cell secretome may also be considered as a potential therapy for the management of ARDS in patients suffering from severe pneumonia, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), however, their effectiveness requires further investigation.     

How Immunosenescence and Inflammaging May Contribute to Hyperinflammatory Syndrome in COVID-19

Aging is characterized by the dynamic remodeling of the immune system designated “immunosenescence,” and is associated with altered hematopoiesis, thymic involution, and lifelong immune stimulation by multitudinous chronic stressors, including the cytomegalovirus (CMV). Such alterations may contribute to a lowered proportion of naïve T-cells and to reduced diversity of the T-cell repertoire. In the peripheral circulation, a shift occurs towards accumulations of T and B-cell populations with memory phenotypes, and to accumulation of putatively senescent and exhausted immune cells. The aging-related accumulations of functionally exhausted memory T lymphocytes, commonly secreting pro-inflammatory cytokines, together with mediators and factors of the innate immune system, are considered to contribute to the low-grade inflammation (inflammaging) often observed in elderly people. These senescent immune cells not only secrete inflammatory mediators, but are also able to negatively modulate their environments. In this review, we give a short summary of the ways that immunosenescence, inflammaging, and CMV infection may cause insufficient immune responses, contribute to the establishment of the hyperinflammatory syndrome and impact the severity of the coronavirus disease 2019 (COVID-19) in elderly people.     

Efficacy of Nerve-Derived Hydrogels to Promote Axon Regeneration Is Influenced by the Method of Tissue Decellularization

Injuries to large peripheral nerves are often associated with tissue defects and require reconstruction using autologous nerve grafts, which have limited availability and result in donor site morbidity. Peripheral nerve-derived hydrogels could potentially supplement or even replace these grafts. In this study, three decellularization protocols based on the ionic detergents sodium dodecyl sulfate (P1) and sodium deoxycholate (P2), or the organic solvent tri-n-butyl phosphate (P3), were used to prepare hydrogels. All protocols resulted in significantly decreased amounts of genomic DNA, but the P2 hydrogel showed the best preservation of extracellular matrix proteins, cytokines, and chemokines, and reduced levels of sulfated glycosaminoglycans. In vitro P1 and P2 hydrogels supported Schwann cell viability, secretion of VEGF, and neurite outgrowth. Surgical repair of a 10 mm-long rat sciatic nerve gap was performed by implantation of tubular polycaprolactone conduits filled with hydrogels followed by analyses using diffusion tensor imaging and immunostaining for neuronal and glial markers. The results demonstrated that the P2 hydrogel considerably increased the number of axons and the distance of regeneration into the distal nerve stump. In summary, the method used to decellularize nerve tissue affects the efficacy of the resulting hydrogels to support regeneration after nerve injury.     

Consumption of Fish in Chronic Kidney Disease – A Matter of Depth

Fish is an excellent source of ω-3 polyunsaturated fatty acids (PUFAs), amino acids, collagen, vitamins, and iodine and its intake is associated with health benefits, mainly reduces risk of cardiovascular mortality. However, recent studies have shown that fish is also an important source of trimethylamine N-oxide (TMAO), a uremic toxin produced by the gut microbiota that promotes an increased risk of cardiovascular diseases. In patients with chronic kidney disease (CKD), TMAO levels are markedly increased due to gut dysbiosis and reduced kidney function. No study has yet evaluated the effects of a fish-rich diet on TMAO plasma levels and cardiovascular outcomes. This review discusses the pros and cons of a fish-rich diet in patients with CKD – a matter of depth.     

Emulsion polymerisation of MMA employing a chain transfer agent of low environmental impact: ISO‐octyl‐3‐mercaptopropionate

The unseeded batch‐emulsion polymerisation of methyl methacrylate (MMA) was investigated using the chain transfer agent iso‐octyl‐3‐mercaptopropionate (iOMP), which exhibits a low environmental impact. The commercial iOMP is a mixture of over 10 isomers that proved adequate to control the molecular weights of poly(methyl methacrylate) with a decreasing evolution of both the number‐ and weight‐average molecular weights along the reactions. The iOMP also affects the polymerisation kinetics as a consequence of the lower reactivity of the iOMP radicals with respect to the MMA‐ended radicals. Experimental results were interpreted with the help of a first principles mathematical model. © 2013 Canadian Society for Chemical Engineering