Infrared thermography of external ocular surface in patients with absolute glaucoma in transscleral cyclophotocoagulation: a pilot study

Background: Changes in the temperature of external ocular surface in patients with absolute neovascular glaucoma (including the changes after transscleral contact cyclophotocoagulation with scleral compression (TCCSC)) are still to be investigated. Purpose: To use infrared thermography (1) to investigate thermal patterns and to estimate the temperature of the external ocular surface in healthy individuals and (2) to compare these characteristics in the glaucomatous eyes versus intact fellow eyes of patients with absolute glaucoma undergoing treatment with 1064-nm TCCSC. Materials and Methods: Twenty healthy volunteers (40 eyes) and 45 patients (90 eyes) with absolute glaucoma were under observation. All 130 eyes underwent visual acuity assessment, anterior eye photography, and infrared thermography of the external corneal surface. Each patient underwent three sessions of 1 064-nm TCCSC. Results: In healthy subjects, mean external ocular surface temperature was 34.5 ± 0.7°C. For patients with absolute glaucoma, external corneal surface temperature at baseline was higher in intact fellow eyes than in glaucomatous eyes (34.3 ± 0.9°C versus 33.1 ± 0.8°С, P = 0.0008). In addition, increases in the temperature of external ocular surface were observed in the course of decrease in IOP after 1 064-nm TCCSC. Conclusion: In patients with absolute glaucoma, infrared thermography found a marked thermal pattern asymmety between glaucomatous eyes and intact fellow eyes. In addition, increases in the temperature of external ocular surface in the course of decrease in IOP after 1064-nm TCCSC may be apparently attributed to improved ocular blood flow and inflammatory response of the ciliary body to laser photocoagulation

Quantitative Structure-Activity Relationship, Ontology-Based Model of the Antioxidant and Cell Protective Activity of Peat Humic Acids

Peat humic acids are well known for their wide range of biological effects which can be attributed to the complex chemical structure of naturally occurring humic substances. One of the promising tools is an ontology-based quantitative analysis of the relationship between physical and chemical parameters describing a chemical structure of peat humic acids and their biological activity. This article demonstrates the feasibility of such an approach to estimate the antioxidant and cell protective properties of the peat humic acids. The structural parameters of the peat humic acids were studied by electronic, fluorescence, infrared, 13C-NMR spectroscopy, titrimetric analysis, elemental C,H,N, and O- analysis, and gel chromatography. Antioxidant and antiradical activities were assessed by physicochemical methods of analysis: electronic paramagnetic resonance, cathodic voltammetry, ABTS•+ scavenging, assay of DPPH radical-scavenging activity, assay of superoxide radical-scavenging activity, iron chelating activity, and scavenging of hydroxyl radicals. Cytoprotective activity was evaluated by the neutral red-based cytotoxicity test in 3T3-L1 cell culture in a wide range of concentrations. Assessment of intracellular ROS production was carried out using a 2,7-dichlorodihydrofluoresceindiacetate (DCFDA) fluorescent probe. Intracellular ROS production was induced using two common prooxidants (tert-butyl hydroperoxide, Fe2+ ions). We suggested an ontology-based model for the antioxidant and cytoprotective activity of humic acids based on experimental data and numerical models. This model establishes the way to further research on the biological effects of humic acids and provides a useful tool for numerical simulation of these effects. Remarkable antioxidant and cell protective activity of humic acids makes them a promising natural source of new pharmaceutical substances that feature a wide range of biological effects

Revealing New Patterns in Resource­saving Processing of Chromium­containing Ore Raw Materials by Solid­phase Reduction

The physical and chemical properties of products from the carbon-thermal reduction of oxide chromo-containing ore raw materials have been investigated. This is necessary to determine the parameters that reduce the loss of Cr in the processing of ore materials and the use of metallized chromium doping additives in steelmaking. It has been determined that the increase in processing temperature from 1,250 K to 1,450 K led to an increase in the manifestation of Cr23C6 and (Cr, Fe)7C3. In this case, the diffraction maxima of Cr2O3 corresponded to the trend of weakening and, having been treated at 1,450 K, had a residual character. Cr3C2 on the diffractograms was only evident after processing at 1,250 K. The phase of the metallic Cr was traced in the samples after processing at 1,350 K and 1,450 K with the increased intensity of manifestation when the heating temperature rose. It has been determined that the microstructure of reduction products is heterogeneous with the presence of particles of different sizes and chemical compositions. The increase in the reduction temperature from 1,250 K to 1,350 K and 1,450 K and the development of reduction processes were accompanied by particle sintering with the formation of a spongy microstructure. We have detected regions that characterized inclusions and the phases where Cr content amounted to 65.10 % by weight, Fe ‒ to 16.13 % by weight. Some local areas with particles with a relatively high content of ore impurities and carbon have also been found. It follows from the results of our study that the most acceptable temperature for reduction is 1,450 K. In this case, the reduction is ensured with a predominance in the phase composition of the metal Cr and carbides (Cr, Fe)7C3 and Cr23C6 relative to the oxide component of Cr2O3. In this case, the lower residual carbon content was due to the higher efficiency of the reducer compared to other temperature regimes.The spongy microstructure allows for a Faster dissolution compared to standard ferroalloys, thereby reducing the duration of smeltin

Enhanced Antioxidant Activity and Reduced Cytotoxicity of Silver Nanoparticles Stabilized by Different Humic Materials

The current article describes the biological activity of new biomaterials combining the “green” properties of humic substances (HSs) and silver nanoparticles. The aim is to investigate the antioxidant activity (AOA) of HS matrices (macroligands) and AgNPs stabilized with humic macroligands (HS-AgNPs). The unique chemical feature of HSs makes them very promising ligands (matrices) for AgNP stabilization. HSs have previously been shown to exert many pharmacological effects mediated by their AOA. AgNPs stabilized with HS showed a pronounced ability to bind to reactive oxygen species (ROS) in the test with ABTS. Also, higher AOA was observed for HS-AgNPs as compared to the HS matrices. In vitro cytotoxicity studies have shown that the stabilization of AgNPs with the HS matrices reduces the cytotoxicity of AgNPs. As a result of in vitro experiments with the use of 2,7-dichlorodihydrofluorescein diacetate (DCFDA), it was found that all HS materials tested and the HS-AgNPs did not exhibit prooxidant effects. Moreover, more pronounced AOA was shown for HS-AgNP samples as compared to the original HS matrices. Two putative mechanisms of the pronounced AOA of the tested compositions are proposed: firstly, the pronounced ability of HSs to inactivate ROS and, secondly, the large surface area and surface-to-volume ratio of HS-AgNPs, which facilitate electron transfer and mitigate kinetic barriers to the reduction reaction. As a result, the antioxidant properties of the tested HS-AgNPs might be of particular interest for biomedical applications aimed at inhibiting the growth of bacteria and viruses and the healing of purulent wounds

Revealing new patterns in resource saving processing of chromium containing ore raw materials by solid phase reduction

Дослiджено фiзико-хiмiчнi властивостi продуктiв вуглецевотермiчного вiдновлення оксидної хромвмiсної рудної сировини. Це необхiдно для визначення параметрiв, що знижують втрати Cr при переробцi рудних матерiалiв i використаннi металiзованих хромвмiсних легуючих добавок у сталеплавильному виробництвi. Визначено, що пiдвищення температури обробки з 1250 K до 1450 K призвело до збiльшення прояву Cr23C6 та (Cr, Fe)7C3. При цьому дифракцiйнi максимуми Cr2O3 вiдповiдали тенденцiї послаблення та пiсля обробки при 1450 K мали залишковий характер. Cr3C2 на дифрактограмах провялявся лише пiсля обробки при 1250 K. Фаза металевого Cr прослiдковувалась в зразках пiсля обробки при 1350 K та 1450 K з пiдсиленням iнтенсивностi прояву при збiльшеннi температури нагрiвання. Визначено, що мiкроструктура продуктiв вiдновлення неоднорiдна з присутнiстю часток рiзного розмiру та хiмiчного складу. З пiдвищенням температури вiдновлення з 1250 K до 1350 K та 1450 K i розвитком вiдновних процесiв мало мiсце спiкання часток з утворенням губчастої мiкрострукту ри. Виявлено дiлянки, що характеризували включення i фази iз вмiстом Cr до 65,10 % мас., Fe – до 16,13 % мас. Також виявлено окремi локальнi дiлянки з частками з вiдносно високим вмiстом рудних домiшок та вуглецю. З отриманих результатiв дослiдження витiкає, що найбiльш прийнятною температурою для вiдновлення є 1450 K. В цьому випадку забезпечується вiдновлення з переважанням у фазовому складi Cr металевого та карбiдiв (Fe, Cr)7C3 i Cr23C6 вiдносно оксидної складової Cr2O3. При цьому менший залишковий вмiст вуглецю обумовлений бiльш високою ефективнiстю дiї вiдновника порiвняно з iншими температурними режимами. Завдяки губчастiй мiкроструктурi стає можливим бiльш швидке розчинення, порiвняно iз стандартними феросплавами, при цьому реалiзується скорочення часу виплавки