During austral summer 1978/1979 the content of dissolved oxygen, phosphates, nitrates and nitrites was determined in the waters of Admiralty Bay. Environmental conditions prevailing in Admiralty Bay are compared with the conditions in the open Antarctic waters.
The use of hyperbaric oxygen therapy (HBOT) is an accepted method of supporting wound healing in human medicine. Yet, because of the risk of complications associated with HOBT, a safer modification of the therapy, known as L-HOBT (lower pressure and lower oxygen concen- tration), is increasingly used nowadays. Therefore, due to the lack of literature reports regarding the clinical use of L-HBOT in animals, the authors decided to present the results of L-HBOT supportive treatment of postoperative wounds after hemimastectomy compared to classic treat- ment. The study group included 12 bitches divided into two groups: group A (assisted L-HBOT) and group B (classic treatment). In addition to conventional treatment, the supportive therapy included 1.5 hours of hyperbaric chamber therapy for 5 consecutive days, starting 24 hours after surgery (1500hPa pressure and 26% oxygen concentration in the chamber). The patients were followed and evaluated throughout the course of the treatment by two independent doctors. The results of the treatment revealed no negative clinical impact of L-HOBT supportive therapy on the body of the animals. At the same time, postoperative wounds after L-HOBT healed faster and with fewer postoperative complications compared to the control group. This resulted in a shorter treatment period, terminating with an earlier skin suture removal.
Parameters of surface acoustic waves (SAW) are very sensible to change of physical conditions of a propagation medium. In the classical theory formulation, the waves are guided along the boundary of semi-infinity solid state and free space. A real situation is more complex and a medium commonly consists of two physical components: a solid substrate and a gaseous or liquid environment. In the case of stress-free substrate, the strongest impact on SAW properties have surface electrical and mechanical conditions determined by solids or liquids adhering to the boundary. This impact is utilised for constructing sensors for different gases and vapours e.g. (Jakubik et al., 2007; Hejczyk et al., 2011; Jasek et al., 2012). The influence of gaseous environment on the SAW properties is usually very weak and ignored. However, in certain condition it can be significant enough to be applied to sensor construction. In general, it concerns Rayleigh wave devices where energy leakage phenomenon is perceptible, especially when the gas being detected considerably changes the density of environment. The paper presents the results of experiments with oxygen-nitrogen mixture. Their primary aim was focused on finding the dependence of resonant frequency and attenuation in SAW resonator on parameters and concentrations of the gas in the environment.
Operations conducted by petroleum industry generate an entire range of drilling waste. The chemical composition of drilling waste and its toxicity depend primarily on the geological and technological conditions of drilling, the type of drilled rock deposits and on the type and composition of the drilling mud used. In the course of drilling operations, drilling fluids are in constant contact with bacteria, fungi and other organisms infecting the mud. Pioneer species, capable of surviving and using the resources of this specific environment, are selected. For this reason, the effectiveness of microbiota survival on different types of spent drilling muds and in different dilutions with brown soil was measured. Spent drilling muds samples came from drilling operations in various regions of Poland, e.g. Subcarpathia, the Polish Lowland and Pomerania regions. Oxygen consumption after 96 h was around 20 μg·g‒1 dry mass in soil or soil/drilling water-based mud mixture. Soil mixes contained 10 wt% synthetic base, mud had a higher oxygen consumption – 38 μg · g‒1 dry mass. Oxygen consumption decreases sharply as the content of the spent synthetic base mud fraction increases. A higher concentration of spent SBM (35 wt%) reduced the aerobic metabolism by slightly more than 50%. A high concentration of reduced carbon decreased the respiratory quotient (RQ) value to 0.7. All the researched drilling waste shows microbiological activity. At the full concentration of drilling fluids and non-dilution options, the chemical composition (salinity, inhibitors, etc.) strongly inhibits microbiota development and consequently, respiration
Tin dioxide (SnO2) is an n-type semiconductor and has useful characteristics of high transmittance, excellent electrical properties, and chemical stability. Accordingly, it is widely used in a variety of fields, such as a gas sensor, photocatalyst, optoelectronics, and solar cell. In this study, SnO2 films are deposited by thermal atomic layer deposition (ALD) at 180°C using Tetrakis(dimethylamino)tin and water. A couple of 5.9, 7.4 and 10.1nm-thick SnO2 films are grown on SiO2/Si substrate and then each film is annealed at 400°C in oxygen atmosphere. Current transport of SnO2 films are analyzed by measuring current – voltage characteristics from room temperature to 150°C. It is concluded that electrical property of SnO2 film is concurrently affected by its semiconducting nature and oxidative adsorption on the surface.
Samples for the study were collected from, known from the literature, outcrop profiles in Zarzecze, Radymno, Dybawka, Tarnawce and Pikulice-Nehrybka, situated at the Carpathian border, in the vicinity of the Przemyśl town, close to the San River valley (SE Poland). They represent the Vistulian loess-palaeosol sequences. Carbonates occur mainly in the loesses representing OIS 2 and 3. Pollen analysis, carried out for two profiles (Tarnawce, Radymno), throws light on palaeoecological conditions of loess cover formation and transformation.Isotopic analysis of authigenic carbonates was carried out on carbonate cemented bodies dispersed throughout the loess in forms of nodule, rhizolith and rhizocretion and on bioclasts, mainly snail shells, ostracod valves, and sparse globules (probably the internal shells of the naked snails).In the successions studied, the upper Vistulian loess deposited in environment with poor vegetation, contains rhizo- liths and rhizocretions mainly, while in the middle and lower Vistulian loess with well developed soils, gley horizons, and intercalations of subaqueous sediments, remains of snail shells and ostracod valves prevail. The two main forms of carbonates differ markedly in isotopic composition from one another. These differences seem to be more important than those between samples of one form of carbonates along particular sections. That is the result of numerous factors affecting the fractionation of carbon and, in particular, oxygen stable isotopes in the environment of precipitation of authigenic calcite. The isotopic composition of carbonates cementing sediments is controlled mainly by biominerali- zation of organic matter and local climatic parameters which were rather slightly differentiated during the formation of the studied sediments. The d13C values for bioclasts vary in a broader range than for calcitic cements. Usually the snail shell carbonate is more enriched with heavier carbon isotope than that from ostracod valves, resulting from the isotopic equilibrium with precipitation and with surface waters, respectively. Basing on our study we can conclude that fluctuations of isotope composition of authigenic carbonates make it hard to apply as a paleoclimatic indicator. However, the general trend of d18O variation in analysed carbonate fractions from leoss-palaeosol sequences displays some connections with climatic fluctuations.
The organic carbon (OC)-rich, black shale succession of the Middle Triassic Bravaisberget Formation in Spitsbergen contains scattered dolomite-ankerite cement in coarser-grained beds and intervals. This cement shows growth-related compositional trend from non-ferroan dolomite (0–5 mol % FeCO3) through ferroan dolomite (5–10 mol % FeCO3) to ankerite (10–20 mol % FeCO3, up to 1.7 mol % MnCO3) that is manifested by zoned nature of composite carbonate crystals. The d13C (-7.3‰ to -1.8‰ VPDB) and d18O (-9.4‰ to -6.0‰ VPDB) values are typical for burial cements originated from mixed inorganic and organic carbonate sources. The dolomite-ankerite cement formed over a range of diagenetic and burial environments, from early post-sulphidic to early catagenic. It reflects evolution of intraformational, compaction-derived marine fluids that was affected by dissolution of biogenic carbonate, clay mineral and iron oxide transformations, and thermal decomposition of organic carbon (decarboxylation of organic acids, kerogen breakdown). These processes operated during Late Triassic and post-Triassic burial history over a temperature range from approx. 40°C to more than 100°C, and contributed to the final stage of cementation of the primary pore space of siltstone and sandstone beds and intervals in the OC-rich succession.
In this study defense responses in three potato varieties with different levels of reaction to the late blight disease caused by Phytophthora infestans were analyzed after inoculation with the pathogen. In the resistant cv. Pastusa Suprema, increased intensity of H2O2 and callose deposit accumulation was observed beginning at 24 hours after inoculation, followed by a hypersensitive response at the inoculation points. In the moderately resistant cv. Diacol-Monserrate, the same responses were observed as in the resistant variety, but with less intensity over time. For the susceptible cv. Diacol-Capiro, the responses observed occurred later than in the other two varieties, subsequent to the advance of the pathogen over extensive necrotic areas. These results suggest that early, intense peroxide and callose accumulation and a hypersensitive response are associated with the observed resistance of the cv. Pastusa Suprema and cv. Diacol-Monserrate to P. infestans.
In the present study, the influence of the infection with equine herpesvirus type 1 (non-neuropathogenic and neuropathogenic strains of EHV-1) on the morphology and distribution of mitochondrial network in equine dermal cell line was investigated. Our results indicate that EHV-1-infection caused changes in the mitochondrial morphology manifested mostly by fission and reactive oxygen species generation.
Dehydroabietic acid R=COOH (DHA), a naturally occuring diterpene resin acid, is an activator of systemic acquired resistance (SAR) under biotic stress. However, there had been no report on its functioning under salinity. In the present study, we determined the effects of DHA on salinity and its possible role as a signal transmitter in soybean (Glycine max L.) leaves under salinity (200 mM NaCl). Furthermore, physiological parameters, chlorophyll, proline, malondialdehyde (MDA), hydrogen peroxide (H2O2) content, superoxide (O2‾) and hydroxyl radical (•OH) scavenge capacity, as well as antioxidant enzymes (SOD, POX, APX and GST) and GmWRKY-71 gene expressions were investigated in the treated plants at 6 h, 12 h and 24 h. The obtained results showed that pretreatment of DHA caused (1) a reduction in salt-induced damage, (2) improvement in biomass yield, water status, chlorophyll and leaf area, (3) regulation of the proline level and relative electrolyte leakage, (4) increase in reactive oxygen species (ROS) scavenging capacity, (5) induction of SOD and APX enzyme activity at all the investigated periods, while POX only at 6 h, and thus alleviation of the oxidative damage. In addition, the changes in GmWRKY-71 gene expressions were remarkable in soybean under salinity. To sum up, these results showed that DHA can be used as a ROS inhibitor or a signal molecule in increasing salt tolerance in soybean under salinity.
Measurements were made of sediment characteristics, benthic microbial activity and optimum temperature for sulfate reduction at Signy Island, South Orkney Islands, Antarctica . There was little evidence to support any seasonal variation in oxygen penetration of surface sediments. Oxygen penetrated to only 1.5 to 3 mm throughout the year, despite bioturbation from a dense amphipod population. The distribution of acid volatile sulfides increased with depth below 1 cm and above this, surface sediments were lighter in colour and contained fewer sulfides. The rates of sulfate reduction increased during winter under sea-ice cover, and remained high after ice break up. Seasonal water temperature was relatively constant between –1.8 and 0.5°C. Optimum temperature for anaerobic sediment respiration was investigated using different substrates and was found to be in the range 17–27°C, suggesting that sulfate reducing bacteria are psychrotolerant as they were inhibited by low temperatures.
Diagenetic carbonate deposits (concretions, cementation bodies and cementstone bands) commonly occur in organic carbon-rich sequence of the Agardhfjellet Formation (Upper Jurassic) in Spitsbergen . They are dominated by dolomite/ankerite and siderite. These deposits originated as a result of displacive cementation of host sediment in a range of post-depositional environments, from shallow subsurface to deep-burial ones. Preliminary results of the carbon and oxygen isotopic survey of these deposits in southern Spitsbergen (Lĺgkollane, Ingebrigtsenbukta, Reinodden, and Lidfjellet sections) show the δ13C values ranging between –13.0‰ and –1.8‰ VPDB, and the δ18O values between –16.0‰ and –7.7‰ VPDB. These results suggest that the major stage of formation of the carbonate deposits occurred during burial diagenesis under increased temperature, most probably in late diagenetic to early catagenic environments. Carbonate carbon for mineral precipitation was derived from dissolution of skeletal carbonate and from thermal decomposition of organic matter.