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Organic-rich carbonate sediments are deposited in a range of environments today and in the geologic past. A significant part of organic matter (OM) degradation in such sediments often occurs by microbial reduction of seawater sulfate, and the sulfide product may be preserved in pyrite and in organic sulfur (S) compounds. The isotopic composition (δ34S) of these phases can provide valuable information about S cycling in the ocean and in sediment porewaters, but only insofar as the processes governing these δ34S values are understood. To this end, we investigated the pathways, timing and interactions between pyrite and organic S formation during the deposition of organic-rich chalks. As a test case, we studied cores representing the thickest (∼350 m) and most complete Late Cretaceous organic-rich sequence along the southern Paleotethyan margin (central Israel). The organic S and OM contents show an inverse relation with the pyritic S content, which together with the uniform FePy/FeHR ratio (∼40%), suggest competition between organic S and pyrite formation. Both kerogen and pyritic S are 34S-depleted relative to Late Cretaceous marine sulfate (δ34S∼17–20‰), but the kerogen S is consistently and unusually 34S-enriched relative to coexisting pyrite by up to ∼38‰. Large S isotope fractionation (∼60‰) during microbial sulfate reduction necessary to reproduce the lowest pyrite δ34S values in the core, and relatively invariant δ34S values in organic S suggests that this large fractionation was approximately constant during deposition of the chalks in the core. Higher pyrite δ34S values observed in the most organic-rich parts of the core may be explained by Fe-limited pyrite formation, perhaps due to the reaction of Fe (e.g., complexation, sorption) with organic compounds. Lesser Fe availability, relative to the OM available for sulfate reduction, limits the ultimate abundance of pyrite, but importantly, it delays the formation of pyrite to deeper below the sediment-water interface, from 34S-enriched sulfide produced by Rayleigh distillation of a dwindling sulfate reservoir. Thus, it appears that competing Fe-OM, S-OM and Fe-S reactions can significantly affect the δ34S values recorded in pyrite in organic-rich carbonate sediments despite large and relatively constant microbial S isotope fractionation.

This study investigates how glacially delivered reactive iron (oxyhydr) oxide and manganese oxide phases influence the biogeochemical cycling of sulfur in sediments of three Arctic fjords and how the biogeochemical signatures of these processes are preserved. Results reveal differences in the concentrations of dissolved iron and manganese in pore-waters and the concentration of solid-phase sulfur species within individual fjords and amongst the three fjords, likely controlled by the varying input of reactive iron (oxyhydr) oxides to the sediment. Broadly, the stations can be divided into three categories based on their biogeochemical signals. Stations in the first category, located in Smeerenburgfjorden, are characterized by relatively low concentrations of (easily) reducible particulate iron phases, increasing concentrations of iron monosulfides, pyrite, and elemental sulfur with depth, and low pore-water dissolved iron and manganese concentrations. Biogeochemical processes at these stations are primarily driven by organoclastic sulfate reduction, sulfur disproportionation and the subsequent reaction and sequestration of sulfide in the sediment as iron monosulfide and pyrite. Sulfur and oxygen isotope values of sulfate display progressive enrichment in heavy isotopes with depth at these stations. In contrast, concentrations of (easily) reducible particulate iron phases and pore-water dissolved iron (up to 850 mu M) and manganese (up to 650 mu M) are very high at stations of the second and third category, located in Kongsfjorden and Van Mijenfjorden, while iron monosulfide and pyrite contents are extremely low. The amount of pyrite and its isotope values in conjunction with organic sulfur compounds provide evidence for a detrital origin of a fraction of these sulfur compounds. At the Kongsfjorden and Van Mijenfjorden stations, oxidative pathways of the sedimentary sulfur cycle, controlled by the high availability of reducible particulate iron phases, play an important role, leading to the effective recycling of sulfide to sulfate through sulfur intermediates and concomitant resupply of the sulfate reservoir with S-32. In both fjords, elemental sulfur was only detected at the outer fjord stations grouped into the third category. Our study provides a framework for interpreting the Fe-S-C geochemistry of similar continental shelf areas in modern settings and ultimately for identifying these environments in the rock record.

The accumulation of oxygen in Earth’s atmosphere and oceans in the late Archean had profound implications for the planet’s biogeochemical evolution. Oxygen impacts sulfur cycling through the oxidation of sulfide minerals and the production of sulfate for microbial sulfate reduction (MSR). The isotopic signature of sulfur species preserved in the geologic record is affected by the prevailing biological and chemical processes and can therefore be used to constrain past oxygen and sulfate concentrations. Here, in a study of a late Archean analogue, we find that the sulfur isotopic signature in the water column of a seasonally stratified lake in southern China is influenced by MSR, whereas model results indicate that the isotopic signature of the underlying sediments can be best explained by concurrent sulfate reduction and sulfide oxidation. These data demonstrate that small apparent sulfur isotope fractionations (δ34Ssulfate-AVS = 4.2‰–1.5‰; AVS—acid volatile sulfides) can be caused by dynamic sulfur cycling at millimolar sulfate concentrations. This is in contrast to current interpretations of the isotopic record and indicates that small fractionations do not necessarily indicate very low sulfate or oxygen.

In order to characterize biogeochemical sulfur cycling in the metalimnion of a thermally stratified freshwater lake, we followed changes in the concentrations and isotopic composition of sulfur species during a 24-h period, during which the chemocline oscillated at an amplitude of 5.3 m due to internal wave activity. Hourly sampling at a fixed depth (17.1 m) enabled study of redox changes during the transition from oxic to sulfidic conditions and vice versa. The oxidation–reduction potential, pH, conductivity and turbidity correlated linearly with the water temperature (a proxy for depth relative to the chemocline). The highest concentrations of thiosulfate and sulfite were detected approximately 2.5 m below the chemocline. Concentrations of zero-valent sulfur increased ~ 10 fold when the chemocline rose into the photic zone due to phototrophic sulfide oxidation. Triple isotopic composition of sulfur species indicates a shift with depth from values typical for sulfate reduction right below the chemocline to values which may be explained by either sulfate reduction alone or by a combination of microbial sulfate reduction and microbial sulfate disproportionation. We conclude that consumption of hydrogen sulfide at the chemocline of Lake Kinneret is controlled by the combination of its chemical and/or chemotrophic oxidation to sulfur oxoanions and predominantly phototrophic oxidation to zero-valent sulfur.

Soft robotics is a growing field of research, focusing on constructing motor-less robots from highly compliant materials, some are similar to those found in living organisms. Soft robotics has a high potential for applications in various fields such as soft grippers, actuators, and biomedical devices. 3D printing of soft robotics presents a novel and promising approach to form objects with complex structures, directly from a digital design. Here, recent developments in the field of materials for 3D printing of soft robotics are summarized, including high-performance flexible and stretchable materials, hydrogels, self-healing materials, and shape memory polymers, as well as fabrication of all-printed robots (multi-material printing, embedded electronics, untethered and autonomous robotics). The current challenges in the fabrication of 3D printed soft robotics, including the materials available and printing abilities, are presented and the recent activities addressing these challenges are also surveyed.

The search for new high-performance antimicrobial compounds remains one of the most important tasks of modern pharmaceutical chemistry, despite the wide range of modern natural, synthetic and semi-synthetic drugs for the treatment of infectious diseases.This is especially true for the naturally occurring compounds, new non-toxic and effective drugs can be created by their chemical modification for the treatment of various infectious pathologies. Recent researches in this area point to significant prospect of new synthetic derivatives of xanthine. The aim of this work is to develop simple laboratory methods for synthesizing 8-aminoderivatives of 7-alkyl-3-methylxanthines and to study their physical and chemical peculiarities and antimicrobial properties. The meltingpoint has been determined with the help of an open capillary method with TAP device (M). Elemental analysis has been performed with the help of the instrument ElementarVario L cube, NMR-spectra have been taken on a spectrometer Bruker SF-400 (operating frequency of 400 MHz, solvent DMSO-d6, internal standard – TMS). These data correspond to the calculated elemental analysis. For the initial screening study of the newly-synthesized substances benchmark testing-cultures of both gram-positive and gram-negative bacteria have been used, which belong to clinically significant groups of infections agents which are differing by their morpho-physiological properties. Through the reaction of 7-alkyl-3-methylxanthines with primary and secondary amines in water, water-ethanol, water-dioxane or cellosolve environment a range of 8-aminoderivativeshas been obtained which was not described earlier. Developing accessible laboratory methods to synthesize new 8-aminoderivatives of 7-alkyl-3-methylxanthines, which are potential bioactive compounds. Studying NMR-spectral characteristics of the obtained substances. Initial screening research of antimicrobial activity of the synthesized compounds has shown that 8-aminoxanthines (4, 6–12) can be used in medical practice as antistaphylococcal drugs, and 3-methyl-8-(4-methylpiperidine-1-yl)-7-n-propilxanthine (5)– antifungal agentafter additional studies.

Oxygen profiles were measured in the sediments of the Gulf of Aqaba (Red Sea), an oligotrophic marine system affected by episodic seasonal flash floods and intense aeolian dry deposition. Sediment cores were retrieved from shallow (15–45 m), intermediate (250–561 m) and deep (700 m) water sites of south–north and east–west transects. Dissolved oxygen concentrations were measured simultaneously by using microelectrodes and microoptodes immediately after sampling and after transportation. Oxygen penetration depths were found to increase from 2 to 5 mm at the shallow water sites with sandy permeable sediments to 10–21 mm at the deeper sites with cohesive muddy sediments. This increase corresponds to decrease in oxygen diffusive fluxes at the sediment–water interface and oxygen consumption rates with depth. Oxygen consumption rates exhibit local maxima at the oxic–anoxic sediment boundary, which may be attributed to oxygen reduction coupled to oxidation of dissolved Fe(II) and Mn(II) at deep and intermediate water sites and of hydrogen sulfide at shallow water sites. Microelectrodes and microoptodes measurements of cohesive sediments from deep and intermediate water sites yielded similar results. By comparison, the microoptodes displayed more robust measurements than microelectrodes in sandy near-shore sediments. This was attributed to their flexible fiber structure that is less likely to break or to abruptly displace sand particles. After transportation of sediment cores from Eilat to Beer Sheva followed by ≤ 24-h storage, no changes in oxygen fluxes and consumption rates were detected.

Special attention of pharmaceutical scientists is attracted to the creation of new potential substances. They select natural heterocyclic molecules that exhibit various types of pharmacological activity as basic structures. Adamantane derivatives, as well as a number of other framework compounds, in the vast majority are biologically active substances. This fact causes interest to the given classes of organic compounds as potential sources for the development of new drugs. Due to the high pharmacological action of 1,2,4-triazole derivatives, the combination of adamantane and 1,2,4-triazole in one molecule can lead to the formation of high-level pharmacological substances. The aim of this work is the synthesis of some 2- (2 - ((5- (adamantane-1-yl) -4-R-1,2,4-triasole-3-yl) thio) acetyl) -N-R1-hydrazine-carbothioamides, study of their physical and chemical properties, antimicrobial and antifungal activity. Materials and methods. The chemical names of the compounds are given in accordance with the requirements of the IUPAC nomenclature (1979) and the recommendations of the IUPAC (1993). Study of the physical and chemical properties of 2-(2-((5-(adamantane-1-yl)-4-R-1,2,4-triazole-3-yl)thio)acetyl)-N-R1-hydrazine-carbothioamides have been carried out on the certified and licensed equipment in the ZSMU physical-chemical laboratories. The melting temperature was determined by an open capillary method on the Opti Melt MPA 100. The elemental composition of the synthesized compounds was determined on the universal analyzer Elementar Vario L cube (CHNS) (standard – sulfanilamide). 1H NMR spectra were recorded on a spectrometer Varian Mercury VX-200 (1H, 200 MHz) in dimethylsulfoxide-d6solvent (tetramethylsilane - internal standard) and are decoded using ADVASP(tm)Analyzer program (Umatek International Inc.). Chromatographic mass spectral studies were performed on a gas-liquid chromatograph Agilent 1260 Infinity HPLC equipped with an Agilent 6120 mass spectrometer (ionization in an electric spray (ESI). Results. New 2-(2-((5-(adamantane-1-yl)-4-R-1,2,4-triazole-3-yl)thio)acetyl)-N-R1-hydrazine-carbothioamides are firstly synthesized, their structure is established by means of modern physical chemical methods of analysis (elemental analysis, IR-, NMR 1H-spectroscopy), and their individuality is done by HPLC-MS method. In all cases, the meanings of the investigated physical and chemical constants coincide with the estimated theoretical indicators. Determination of antimicrobial and antifungal activity was carried out by 2-fold serial dilutions method in liquid nutrient media. As a result of conducted investigations the compounds which levels of antimicrobial and antifungal action approaching, and in some cases exceeding comparison drug trimethoprim were revealed among the synthesized compounds. Conclusions. A compound of 2-(2-((5-(adamantane-1-yl)-4-phenyl-1,2,4-triazole-3-yl)thio)acetyl)-N-ethyl-hydrazine-carbothioamide occurred as the most active in relation to all test-strains among the synthesized substances, the force of antimicrobial and antifungal activity of it several times exceeds the comparison standard trimethoprim.

Conductive copper inks have attracted much attention as low-cost replacement for the currently used silver inks for printed electronics. The copper inks should be stable to oxidation at all stages of fabrication of conductive patterns: ink formulation and storage, printing, and post-printing treatment. In the present study, air-stable copper-silver core-shell (Cu@Ag) submicron particles were utilized in conductive ink formulations. To improve the conductivity of the resulting Cu@Ag coatings, the effect of various carboxylic acids was evaluated. It was found that all acids led to decreased resistivity after sintering at elevated temperatures, while the lowest value was only 4 times higher than the bulk resistivity at 3 wt% of oleic. The mechanism governing the effect of carboxylic acids is discussed, in view of possible stabilizer exchange and oxide dissolution.

Objective – to determine the frequency of serous meningitis of enteroviral etiology and find out their clinical and laboratory features. Materials and Methods. The study included 51 patients with serous meningitis. To confirm the serous meningitis of enteroviral etiology the method of polymerase chain reaction with enteroviruses RNA identification in feces and cerebrospinal fluid and subsequent identification of the enterovirus type 71. The study has been carried out as a part of an open cohort study of the Small Grants Joint Programme WHO/HHWS focused on the programs of the communicable disease control implementation. Results. Enterovirus etiology of serous meningitis was confirmed in 27 (52.9 %) patients, but the genotype of enterovirus type 71 was not detected in any case. The risk group of serous meningitis of enteroviral etiology development were children aged 8–11 years, as the frequency of serous meningitis of enteroviral etiology among them was 40.8 % against 12.5 % (χ 2 = 5.09, p < 0.02) of cases serous meningitis of unknown etiology in the same age group. Serous meningitis of enteroviral etiology, which was not caused by virus type 71, was characterized by acute onset, less pronounced cerebral symptomatology, dissociation of meningeal signs (48.1 %), neutrophilic pleocytosis (25.9 %) at the beginning of the disease and benign course of the disease due to faster regress in the clinical manifestations of the disease such as headache and meningeal signs. Conclusions. Enterovirus etiology of serous meningitis was confirmed in 52.9 % of patients but there was not identification of enterovirus genotype 71. Mostly serous meningitis had enterovirus etiology in children of 8–11 years old. Serous meningitis of enteroviral etiology was not caused by virus type 71, and was characterized by acute onset, less severe cerebral symptoms, dissociation of meningeal signs, neutrophilic pleocytosis at the beginning of the disease and benign course of the disease.

We report on the synthesis of copper-silver core-shell (Cu@Ag) particles with about 1 μm-diameter Cu core coated with a thin (∼20 nm) silver shell, for application in printed electronics as low cost conductive ink. The process is based on using the environmentally friendly sodium formaldehyde sulfoxylate dehydrate as a reducing agent for copper ions and two types of polymeric stabilizers (nonionic PVP and anionic PAA). The formation of core-shell particles is followed by transmetallation reaction on the surface of the Cu particles, where copper atoms function as the reducer for silver ions. Characterization of the submicron particles by SEM, EDS and XRD confirm the core-shell structure. The resulting Cu@Ag particles enable overcoming a major challenge in copper ink, their rapid oxidation in air. It was found that ink formulations based on propylene glycol as the liquid vehicle and containing a silicone based wetting agent possesses the optimal characteristics (wetting, sintering) for printing on a glass substrate. To obtain conductive metallic structures, thermal sintering of metallic patterns was used. The Cu@Ag coating are stable to oxidation for at least 6 months at room temperature, and also during sintering process which is carried out at temperatures up to 250 °C. The conductivity of Cu@Ag coatings after sintering at 250 °C was high, 16% of that for bulk copper.

It has been a clear increase in the number of enteroviral infection (EI) activation in recent years. EI are the widespread agents of infectious diseases in children and adults. Moreover this virus affects various organs and tissues and it results in different symptoms of EI in patients of different age groups. All these facts lead to the difficulties in diagnostics, treatment and prophylactics of the EI clinical forms. Aim of the study was to improve diagnostics of the enteroviral infections (EVI) in children and adults based on the epidemiological features of the definitive clinical forms in season 2016. Materials and Methods. The study was carried out as a part of the Grant Agreement between Zaporizhzhia State Medical University (ZSMU) and "Regional Training Centre of Research in the HealthCare System" (theRepublic ofKazakhstan). 185 patient’s medical documentation was analyzed in the inpatient department. Only symptomatic patients with clinical manifestation of enteroviral infection different forms were included into the study. Polymerase chain reaction (PCR) was used for enteroviruses detection. Results and Discussion: Enterovirus was identified in biological liquids in 36.7 % (68 patients) of cases. Patients with meningitis (35) prevailed among them. Other 9 patients had: exanthema, gastroenteritis, herpangina. An increase in the incidence of morbidity has been noted in August - November with the prevalence of meningitis in August – September, herpangina – in November. Most frequently EVI was detected in children aged 7 – 12 years and in young children. Meningitis dominated in school-aged children, exanthema – in children up to 3 years old. Conclusions. EVI is widespread cause of meningitis, vesicular or ulcerative lesions of the posterior oropharyngeal structures and exanthemas in young and early school-age children. Clear association between season and age features with type of the EVI clinical manifestation has been noted. enteroviral infection; epidemiology; adults; children

The use of Cu-formate-2-amino-2-methyl-1-propanol ink and low-pressure plasma for the formation of highly conductive patterns on heat sensitive plastic substrates was studied. It was found that plasma results in decomposition of copper complex to form metallic copper without heating at high temperatures. Ink composition and plasma parameters (predrying conditions, plasma treatment duration, gas type, and flow rate) were optimized to obtain uniform conductive metallic films. The morphology and electrical characteristics of these films were evaluated. Exposing the printed copper metallo-organic decomposition (MOD) ink to 160 W plasma for 8 min yielded resistivity as low as 7.3 ± 0.2 μΩ cm, which corresponds to 23% bulk copper conductivity. These results demonstrate the applicability of MOD inks and plasma treatment to obtain highly conductive printed patterns on low-cost plastic substrates and 3D printed polymers.

This review describes recent developments in the field of conductive nanomaterials and their application in 2D and 3D printed flexible electronics, with particular emphasis on inks based on metal nanoparticles and nanowires, carbon nanotubes, and graphene sheets. We present the basic properties of these nanomaterials, their stabilization in dispersions, formulation of conductive inks and formation of conductive patterns on flexible substrates (polymers, paper, textile) by using various printing technologies and post-printing processes. Applications of conductive nanomaterials for fabrication of various 2D and 3D electronic devices are also briefly discussed.