Saline Medium Research Articles

Unlocking the potential of a zirconium-based MOF for advanced protective coatings: Delve into the UIO-66 smart release functioning for a bio-based Zn2+ complex

In recent years, the incorporation of nanoreservoirs into epoxy coating (EP) formulations has gained significant traction, primarily for their role in delivering self-healing capabilities. This research endeavor is centered around the synthesis and application of a zirconium-based metal-organic framework (MOF) known as UIO-66, specifically designed for the encapsulation of corrosion inhibitors. A novel breakthrough is achieved by simultaneously loading of a green organic inhibitor (Spand extract) and inorganic zinc cations into the highly porous UIO-66, yielding a pioneering bio-based controlled-release nanoreservoir, denoted as UIO-SP.Zn. The UIO-SP.Zn nanoreservoir is characterized through multiple techniques, including X-ray diffraction, Fourier transform infrared spectroscopy, Brunauer-Emmett-Teller surface area analysis, thermogravimetric analysis, and field emission scanning electron microscopy. The controlled-release and pH-sensitive behavior of the UIO-SP.Zn structure are thoroughly evaluated through inductively coupled plasma and UV–vis spectroscopic analyses at three separate pH levels. Electrochemical impedance spectroscopy results underscore the remarkable enhancement in corrosion protection for steel components exposed to a saline medium (3.5 % NaCl) upon the addition of a 1000 ppm UIO-SP.Zn solution, achieving a total resistance of 10,350 Ω.cm2 after a 96 h immersion. The self-healing and active protection of scratched nano-coatings are meticulously examined through electrochemical techniques, revealing that the EP-coated panel incorporating UIO-SP.Zn nanoreservoirs (EP/UIO-SP.Zn) exhibits a substantial impedance (exceeding 60 kohm.cm2) even after prolonged exposure (72 h). Furthermore, the coating's dry pull-off strength registers a notable increase (40.3 %), while delamination is reduced by 50.1 % compared to the unmodified EP coating, signifying the promising adhesion properties of EP/UIO-SP.Zn.

The genesis of the Chakabeishan Li-(Be) pegmatite deposit in the northern Tibetan Plateau: Evidence from fluid inclusion and lithium isotope

The Chakabeishan (CKBS) deposit is a newly discovered pegmatite-type lithium-beryllium deposit in the northern Qaidam tectonic belt of the northern Tibet Plateau. In recent years, some studies have discussed the genesis of the deposit, but the topic remains unclear. This study constrains the genesis of CKBS deposit based on detailed field observations and mineralogical studies, and presents fluid inclusion data and Li isotopic compositions of Li-rich pegmatites and Li-poor pegmatites. The mineralization characteristics of CKBS deposit shows a trend from weak Be mineralization to Li mineralization in the south to north direction, which shows the magmatic differentiation feature. Four types of fluid inclusions are identified: (1) triphase crystal-bearing inclusions (type-1), (2) biphase CO2-rich inclusions (type-2), (3) biphase aqueous inclusions (type-3), and (4) monophase liquid inclusions (type-4). The Li-rich pegmatites mainly contain type-1 inclusions and type-2 inclusions, while Li-poor pegmatites contain type-3 inclusions and some type-4 inclusions. Microthermometric and Laser Raman spectroscopy analyses show that Li-rich pegmatites formed in a low to medium temperature (210.5 ∼ 381.3 ℃), low to medium salinity (5.23 ∼ 17.82 % NaCl equiv.) NaCl-H2O-CO2 system, whereas Li-poor pegmatites formed in a low to medium temperature (206.4 ∼ 413.4 ℃), low to medium salinity (1.05 ∼ 10.49 % NaCl equiv.) NaCl-H2O system, which indicates a fluid immiscibility between them. In addition, lithium is greatly enriched in Li-rich pegmatites under the positive effects of CO2. The Li-rich pegmatites display high Li content (8362.4 ∼ 15509.6 ppm) but low δ7Li values (1.61 ∼ 1.80 ‰). In contrast, the Li-poor pegmatites display low Li content (23.9 ∼ 231.9) but high δ7Li values (0.79 ∼ 12.32 ‰). This means that the lithium isotopic fractionation is produced by the melt-fluid immiscibility in CKBS deposit, in which a Li-rich system with rich water and poor silicate and a Li-poor system with poor water and rich silicate were formed during the process. Therefore, the CKBS deposit may have formed under the combined effects of magmatic differentiation, melt-fluid immiscibility, and fluid immiscibility.

Impact of Mannitol Bladder Distension in the Intraoperative Detection of Ureteral Kinking During Pelvic Floor Surgery

Introduction and HypothesisUreteral injuries are the most feared complications of gynecological surgery and therefore intraoperative recognition is of the utmost importance. Intraoperative cystoscopy represents the diagnostics of choice to investigate ureteral patency thanks to the direct visualization of ureteral flows after administration of infusion mediums. In this study, we aimed to compare the diagnostic performance of saline versus mannitol intraoperative cystoscopy in terms of false negatives in a large cohort of patients.MethodsWe retrospectively analyzed data of patients who underwent vaginal hysterectomy and high uterosacral ligament suspension for POP. Patients were divided in two groups based on the use of saline or mannitol medium for intraoperative cystoscopy. Postoperative daily control of serum creatinine was performed until discharge, as well as urinary tract imaging, in symptomatic patients.ResultsA total of 925 patients underwent vaginal hysterectomy followed by high USL suspension for POP. Saline and mannitol medium were used in 545 patients and 380 patients respectively. Postoperative ureteral injuries were identified in 12 patients, specifically in 2% of the saline group and in 0.3% of the mannitol group.ConclusionsThe use of mannitol instead of saline as a bladder distension medium was able to significantly reduce the occurrence of postoperative ureteral sequelae.

Screening the Rumen of Balochi Camel (Camelus dromedarius) and Cashmere Goat (Capra hircus) to Isolate Enzyme-Producing Bacteria as Potential Additives for Animal Feed.

Rumen microbiology has made a significant contribution to the discovery of biodegradation processes, which convert nutrients into energy for ruminants. Therefore, understanding the enzymatic potential in the rumen of different animal species is essential for developing efficient microbial feed additives. The aim of this study was to isolate enzyme-producing bacteria (EPBs) from the rumen of the Balochi camel (Camelus dromedarius) and Cashmere goat (Capra hircus) as potential additives for animal feed. The EPBs were screened based on the hydrolysis of carboxyl methyl cellulose, tannin, starch, and bovine serum albumin. The isolates were then subjected to enzyme activity assays and molecular characterization. Additionally, they were evaluated for their antagonistic effects, antibiotic susceptibility, and growth in acidic, bile, and saline media. Thirteen enzyme-producing strains were identified in the rumen of the camels and goats, belonging to the genera Klebsiella, Escherichia, Raoultella, Enterobacter and Pectobacterium. The highest and lowest tannase activities were recorded for Escherichia coli GHMGHE41 (10.46Um/l-1) and Raoultella planticola GHMGHE15 (1.83Um/l-1), respectively. Enterobacter cloacae GHMGHE18 (2.03U/ml) was the most effective cellulolytic isolate, compared to Klebsiella strains (1.05Um/l-1). The highest protease producer was Klebsiella pneumoniae GHMGHE13 (3.00U/ml-1), while Escherichia coli GHMGHE17 (1.13U/ml-1) had the lowest activity. Klebsiella pneumoniae GHMGHE13 (1.55U/ml-1) and Enterobacter cloacae GHMGHE19 (1.26U/ml-1) were the highest and lowest producers of amylase, respectively. The strains exhibited mixed responses to antibiotics and remained stable under stressful conditions. These findings indicate that ruminal EPBs have the potential to be used in animal feed, pending further in vivo studies.

Coupling and decoupling of soil carbon and nutrients cycles at different salinity levels in a mangrove wetland: Insights from CUE and enzymatic stoichiometry

Soil carbon (C), nitrogen (N), and phosphorus (P) cycling, in conjunction with microbial metabolism, varies significantly with salinity in coastal areas. However, microbial metabolism limitation on salinity levels has received limited attention. Based on soil microbial carbon use efficiency and enzymatic stoichiometry, microbial nutrient limitation characteristics of soil microbial communities in different salinity levels (4.45 mS·cm−1 - 17.25 mS·cm−1) in a subtropical mangrove wetland were investigated. Compared to low-salinity levels, the activity of soil C-acquiring enzyme activities, enzymatic C:N ratios and enzymatic C:P ratios decreased with medium salinity levels and high salinity levels. Soil microbial metabolism was primarily constrained by C and N at different salinity levels. Boosted regression tree analysis revealed that abiotic factors had the greatest influence on C and N limitation of microbial metabolism at different salinity levels. This study underscores the significance of salinity in microbial metabolic processes and enhances our understanding of how future salinity changes induced by rising sea levels will affect soil carbon and nutrient cycling in coastal wetlands.

Efficacy of 2D/3D HyCoSy with new contrast medium lignocaine and saline comparing with HSG - A single centre prospective study

Tubal patency significantly impacts female infertility, with a substantial portion of cases linked to tubal damage. This hinders gamete and embryo transfer. While laparoscopic chromo-pertubation is the gold standard, its invasiveness prompts the search for alternatives. Common methods for assessing tubal health are Hysterosalpingography (HSG) and Hysterosalpingo Contrast Sonography (HyCoSy).The objective of this study is to assess and compare the efficacy of a budget-friendly 2D/3D HyCoSy method using a unique contrast agent with traditional HSG for diagnosing tubal patency in women with infertility issues.A prospective observational study was conducted within a single clinical setting over a five-year duration. A total of 117 infertile women underwent assessment using both the 2D/3D HyCoSy and HSG techniques.Participants had a mean age of 27.7 years (standard deviation: 4.2, range: 19-45 years). The diagnostic accuracy of 2D/3D HyCoSy was determined with a sensitivity of 91.86%, specificity of 89.18%, a positive predictive value of 90.40%, and a negative predictive value of 90.82%. Comparative analysis revealed that when evaluating tubal patency in both tubes collectively with HyCoSy, the sensitivity, specificity, and overall accuracy were 91.86%, 89.18%, and 90.59%, respectively. The study findings demonstrated that employing 2D/3D HyCoSy with lignocaine gel proved to be a superior diagnostic approach compared to HSG for assessing tubal patency in women experiencing infertility.

Effect of sulfate on the osmoregulatory and physio-biochemical responses of GIFT (Oreochromis niloticus) juveniles reared in potassium-deficient medium saline waters.

The inland saline waters were continuously observed to have low potassium concentrations compared to their seawater counterpart of the same salinity. We hypothesize that the toxic effect of sulfate may manifest in low potassium saline (LPSW) waters compared to brackish water of the same salinity. Thus, LC50 trials were performed in GIFT (genetically improved farmed tilapia) fry (0.5 ± 0.02 g) to determine the acute sulfate toxicity in freshwater (FW, 0.5 g L-1), artificial seawater (ASW, 10 g L-1), and LPSW (10 g L-1). The median lethal concentrations (96h LC50) of sulfate ion in FW, LPSW, and ASW for the GIFT were 5.30 g L-1, 2.56 g L-1, and 2.98 g L-1, respectively. A second experiment was conducted for 21 days, exposing fish to a sub-lethal level of sulfate ion (SO42-) concentration (1000 mg L-1, one-fifth of FW LC50) with different types of waters (FW, freshwater, 0.5 g L-1; ASW, artificial seawater, 10 g L-1; LPSW, low potassium saline water, 10 g L-1) with and without sulfate inclusion to constitute the treatments as follows, (FW, FW + SO4, ASW, ASW + SO4, LPSW, LPSW + SO4). The effect of sulfate on GIFT reared in sulfate-rich potassium-deficient medium saline water was evaluated by focusing on the hematological adjustments, stress-induced oxidative damage, and osmoregulatory imbalances. The survival was not altered due to the sulfate concentration and K+ deficiency; however, there were significant changes in branchial NKA (Na+/K+-ATPase) activity and osmolality. The increase in NKA was highest in LPSW treatment, suggesting that internal ionic imbalance was triggered due to an interactive effect of sulfate and K+ deficiency. The cortisol levels showed a pronounced increase due to sulfate inclusion irrespective of K+ deficiency. The antioxidant enzymes, i.e., SOD (superoxide dismutase), catalase, GST (glutathione-S-transferase), and GPX (glutathione peroxidase), reflected a similar pattern of increment in the gills and liver of the LPSW + SO4 groups, suggesting a poor antioxidant status of the exposed group. The hepatic peroxidation status, i.e. TBARS (thiobarbituric acid reactive substances), and the peroxide values were enhanced due to both K+ deficiency and sulfate inclusion, suggesting a possible lipid peroxidation in the liver due to handling the excess sulfate anion concentration. The hematological parameters, including haemoglobin, total erythrocyte count, and hematocrit level, reduced significantly in the LPSW + SO4 group, indicating a reduced blood oxygen capacity due to the sulfate exposure and water potassium deficiency. The hepatic acetylcholine esterase activity was suppressed in all the treatments with sulfate inclusion, while the highest suppression was observed in the LPSW + SO4 group. Thus, it is concluded that sulfate-induced physiological imbalances manifest more in potassium-deficient water, indicating that environmental sulfate is more detrimental to inland saline water than freshwater or brackish water of the same salinity.

Response of leaf photosynthesis, chlorophyll content and yield of hydroponic tomatoes to different water salinity levels.

Tomato (Solanum lycopersicum L.) is an important vegetable crop that grows easily under controlled conditions, such as in greenhouses and hydroponics. To overcome freshwater scarcity, researchers are searching for alternatives to groundwater sources such as desalinated water (saline water) for irrigation. High salinity in irrigation water alters physiological functions and crop development, thereby reducing the yield. Best management practices and the use of grafted tomato plants on salt-tolerant rootstocks can alleviate salinity stress. The present study was conducted to address the impact of salinity stress on leaf transpiration (Tr), stomatal conductance (gs), photosynthesis (Pn), leaf chlorophyll content, proline content, and yield of hydroponically cultivated tomato plants. Saline (NaCl) water was used for the preparation of nutrient solution with three salinity levels, electrical conductivity (EC, dS m-1) of 2.5 (control), 6.0, and 9.5. Three commercial tomato cultivars (Valouro-RZ, Ghandora-F1, and Feisty-Red) were used. Both self-rooted plants and plants grafted onto Maxifort rootstocks were transplanted onto a perlite substrate. The recorded data revealed that all studied cultivars were critically affected by higher salinity (≈ 9.5 dS m-1) compared to low (≈ 2.5 dS m-1) and medium (≈ 6.0 dS m-1) salinity levels. The Variations in Tr, Pn, gs, chlorophyll content of leaf, and yield between medium and high salinity trials were reported at 3%, 5%, 9%, 5%, and 7.1%, respectively, whereas no significant differences were observed between low and medium salinities. However, at medium salinity levels, grafted plants performed better in photosynthesis than non-grafted plants. This is due to the accumulation of leaf proline, which maintains osmotic regulation and photosynthetic activity by preventing cell damage at medium salinities. Hence, this study confirmed the use of saline water for growing tomatoes under hydroponic conditions up to an EC of 6.0 dS m-1 including the EC of nutrient fertilizers.

Corrosion of an Additively Manufactured Ti6Al4V Alloy in Saline and Acidic Media.

The present work aims to provide corrosion performance data for an additively manufactured Ti6Al4V alloy in saline and polluted environments. The as-received additively manufactured material underwent heat treatment at 850 °C for 3 h to transform the acicular α' microstructure into a lamellar α microstructure. Comparative corrosion assessments were conducted between the heat-treated substrates, the as-received condition, and a conventionally mill-annealed alloy. Potentiodynamic polarization experiments were carried out in saline (3.5 wt.% NaCl) and acid aqueous media ((NH4)2SO4 containing Harrison's solution). The corrosion performance of additively manufactured substrates matched or surpassed that of the conventional alloy in Harrison's solutions while remaining inferior in saline medium, despite forming a thicker passive film. Overall, the XY plane showed better corrosion performance, particularly after the elimination of the acicular α' martensite by the applied heat treatment. The results also suggested that the presence of the coarse β phase was beneficial in 3.5 wt.% NaCl solution and detrimental in Harrison's solutions, more so in acidified and fluorinated conditions.

Salinity-induced succession of phototrophic communities in a southwestern Siberian soda lake during the solar activity cycle

A variety of lakes located in the dry steppe area of southwestern Siberia are exposed to rapid climatic changes, including intra-century cycles with alternating dry and wet phases driven by solar activity. As a result, the salt lakes of that region experience significant fluctuations in water level and salinity, which have an essential impact on the indigenous microbial communities. But there are few microbiological studies that have analyzed this impact, despite its importance for understanding the functioning of regional water ecosystems. This work is a retrospective study aimed at analyzing how solar activity-related changes in hydrological regime affect phototrophic microbial communities using the example of the shallow soda lake Tanatar VI, located in the Kulunda steppe (Altai Region, Russia, southwestern Siberia). The main approach used in this study was the comparison of hydrochemical and microscopic data obtained during annual field work with satellite and solar activity data for the 12-year observation period (2011–2022). The occurrence of 33 morphotypes of cyanobacteria, two key morphotypes of chlorophytes, and four morphotypes of anoxygenic phototrophic bacteria was analyzed due to their easily recognizable morphology. During the study period, the lake surface changed threefold and the salinity changed by more than an order of magnitude, which strongly correlated with the phases of the solar activity cycles. The periods of high (2011–2014; 100–250 g/L), medium (2015–2016; 60 g/L), extremely low (2017–2020; 13–16 g/L), and low (2021–2022; 23–34 g/L) salinity with unique biodiversity of phototrophic communities were distinguished. This study shows that solar activity cycles determine the dynamics of the total salinity of a southwestern Siberian soda lake, which in turn determines the communities and microorganisms that will occur in the lake, ultimately leading to cyclical changes in alternative states of the ecosystem (dynamic stability).

Optimization of Fermentation Process for New Anti-Inflammatory Glycosylceramide Metabolite from Aspergillus sp.

A novel ceramide compound, named Aspercerebroside A (AcA), was successfully isolated from the ethyl acetate layer of the marine symbiotic fungus Aspergillus sp. AcA exhibited notable anti-inflammatory activity by effectively inhibiting the production of nitric oxide (NO) in RAW 264.7 cells at concentrations of 30 μg/mL and 40 μg/mL, offering a promising avenue for the treatment of inflammatory diseases. To optimize the yield of glycosylceramide (AcA), a series of techniques, including single-factor experiments, orthogonal experiments, and response surface optimization, were systematically employed to fine-tune the composition of the fermentation medium. Initially, the optimal carbon source (sucrose), nitrogen source (yeast extract powder), and the most suitable medium salinity (14 ppt) were identified through single-factor experiments. Subsequently, orthogonal experiments, employing an orthogonal table for planning and analyzing multifactor experiments, were conducted. Finally, a mathematical model, established using a Box-Behnken design, comprehensively analyzed the interactions between the various factors to determine the optimal composition of the fermentation medium. According to the model's prediction, when the sucrose concentration was set at 37.47 g/L, yeast extract powder concentration at 19.66 g/L, and medium salinity at 13.31 ppt, the predicted concentration of glycosylceramide was 171.084 μg/mL. The experimental results confirmed the model's accuracy, with the actual average concentration of glycosylceramide under these conditions measured at 171.670 μg/mL, aligning closely with the predicted value.

Response of Sunflower Yield and Water Productivity to Saline Water Irrigation in the Coastal Zones of the Ganges Delta

The intensification of cropping systems in the salt-affected coastal zones of the Ganges Delta can boost food security in the region. The scarcity of fresh water, coupled with varying degrees of soil and water salinity are however limiting factors for the expansion of irrigated cropping in that area. In this study, we assessed the potential of growing sunflowers using combinations of low and medium saline water for irrigation. The experiments were conducted at two locations with six irrigation treatments in 2016–2017 and 2017–2018. The treatments were: T1—two irrigations at early vegetative (25–30 days after sowing; DAS) and flowering stages (60–65 DAS) with low salinity water (LSW, electric conductivity, ECw < 2 dS m−1); T2—two irrigations, one at the vegetative stage with LSW and one at the flowering stage with medium salinity water (MSW, 2 < ECw < 5dS m−1); T3—two irrigations, one at the vegetative stage with LSW and one at seed development stage (75–80 DAS) with MSW; T4—three irrigations at the vegetative, flowering and seed development stages with LSW; T5—three irrigations, at vegetative stage with LSW, and flowering and seed development stages with MSW; and T6—three irrigations, two at the vegetative and flowering stages with LSW and one at the seed development stage with MSW. Irrigation with LSW at early growth stages and MSW at later growth stages did not significantly (p < 0.05) affect the yield compared to the LSW irrigation at early and later growth stages. Crop water productivity and irrigation water productivity of sunflowers (p < 0.001) increased substantially with the decreasing amount of irrigation water with an average of 1.18 kg m−3 and 2.22 kg m−3 in 2017 and 0.92 kg m−3 and 1.29 kg m−3 in 2018, respectively. Grain yield was significantly correlated with root zone solute potential. The flowering and seed development stages of sunflowers in February–March were sensitive to both low and medium saline water irrigation for seed yield. Overall, the results show that irrigation with LSW (ECw < 2dS m−1) at early growth stages and MSW (2 < ECw < 5dS m−1) at later growth stages could be an option for dry-season sunflowers in the coastal zones of the Ganges Delta which would allow double cropping in this area.

Silver-Assisted Hydrogen Evolution from Aluminum Oxidation in Saline Media.

A swarf of aluminum alloy with high corrosion resistance and ductility was successfully converted into fine hydro reactive powders via ball milling with silver powder and either lithium chloride or gallium. The latter substances significantly intensified particle size reduction, while silver formed 'cathodic' sites (Ag, Ag2Al), promoting Al corrosion in aqueous saline solutions with hydrogen generation. The diffraction patterns, microphotographs, and elemental analysis results demonstrated partial aluminum oxidation in the samples and their contamination with tungsten carbide from milling balls. Those factors were responsible for obtaining lower hydrogen yields than expected. For AlCl3 solution at 60 °C, Al-LiCl-Ag, Al-LiCl, Al-Ga-Ag, and Al-Ga composites delivered (84.6 ± 0.2), (86.8 ± 1.4), (80.2 ± 0.5), and (76.7 ± 0.7)% of the expected hydrogen, respectively. Modification with Ag promoted Al oxidation, thus providing higher hydrogen evolution rates. The samples with Ag were tested in a CaCl2 solution as well, for which the reaction proceeded much more slowly. At a higher temperature (80 °C) after 3 h of experiment, the corresponding hydrogen yields for Al-LiCl-Ag and Al-Ga-Ag powders were (46.7 ± 2.1) and (31.8 ± 1.9)%. The tested Ag-modified composite powders were considered promising for hydrogen generation and had the potential for further improvement to deliver higher hydrogen yields.

Development and validation of UV–Vis spectrophotometry-colorimetric method for the specific quantification of rivastigmine tartrate from separable effervescent microneedles: Ex vivo and in vivo applications in complex biological matrices

Rivastigmine Tartrate is an acetylcholinesterase inhibitor commonly used in Alzheimer treatment. Due to its hydrophilicity, short plasma elimination half-time, and poor blood-brain barrier penetration, developing a new drug delivery system for RT administration is essential. Accordingly, microneedles offer several advantages and could be a promising drug delivery system for RT administration. One of those types of MNs with numerous advantages is separable-effervescent microneedles. To support the formulation development, an analytical method using UV–Vis spectrophotometry was validated in phosphate buffered saline media and various biological matrices, such as rat skin, brain, and plasma to measure the amount of RT in the SEMNs preparations. The developed analytical method was validated under ICH guidelines. The results showed that the instrument could specifically detect the RT in the preparations without being interfered with by other compounds. The calibration curves in various biological matrices were linear ≥ 0.9985. The LOD and LLOQ values of the PBS media biological matrices were found to be 1.5 and 4.8 µg/mL, 1.2 and 3.7 µg/mL, 0.42 and 1.27 µg/mL, and 0.38 and 1.16 µg/mL, respectively. All the accuracy and precision values of this developed method were within acceptable ranges. Additionally, the extraction recovery was prominent after undergoing the protein precipitation process. As a result, the analytical method was proven to be valid and was successfully applied to quantify the amount of RT in the SEMNs formulation, in vitro and ex vivo permeation, along with in vivo pharmacokinetic studies.

Origin of Zn-Pb Mineralization of the Vein Bt23C, Bytíz Deposit, Příbram Uranium and Base-Metal Ore District, Czech Republic: Constraints from Occurrence of Immiscible Aqueous–Carbonic Fluids

The mineralogical, fluid inclusion, and stable isotope (C, O) study was conducted on a Late Variscan Zn-Pb vein Bt23C, Příbram uranium and base-metal district, Bohemian Massif, Czech Republic. The vein is hosted by folded Proterozoic clastic sediments in exo-contact of a Devonian-to-Lower-Carboniferous granitic pluton. Siderite, dolomite-ankerite, calcite, quartz, baryte, galena, sphalerite, V-rich mica (roscoelite to an unnamed V-analogue of illite), and chlorite (chamosite) form the studied vein samples. The banded texture of the vein was modified by the episodic dissolution of earlier carbonates and/or sphalerite. Petrographic, microthermometric, and Raman studies of fluid inclusions proved a complicated fluid evolution, related to the activity of aqueous fluids and to an episode involving an aqueous–carbonic fluid mixture. Homogenization temperatures of aqueous inclusions decreased from ~210 to ~50 °C during the evolution of the vein, and salinity varied significantly from pure water up to 27 wt.% NaCl eq. The aqueous–carbonic fluid inclusions hosted by late quartz show highly variable phase compositions caused by the entrapment of accidental mixtures of a carbonic and an aqueous phase. Carbonic fluid is dominated by CO2 with minor CH4 and N2, and the associated aqueous solution has a medium salinity (6–14 wt.% NaCl eq.). The low calculated fluid δ18O values (−4.7 to +3.6‰ V-SMOW) suggest a predominance of surface waters during the crystallization of dolomite-ankerite and calcite, combined with a well-mixed source of carbon with δ13C values ranging between −8.2 and −10.5‰ V-PDB. The participation of three fluid endmembers is probable: (i) early high-temperature high-salinity Na>Ca-Cl fluids from an unspecified “deep” source; (ii) late low-salinity low-temperature waters, likely infiltrating from overlying Permian freshwater partly evaporated piedmont basins; (iii) late high-salinity chloridic solutions with both high and low Ca/Na ratios, which can represent externally derived marine brines, and/or local shield brines. The source of volatiles can be (i) in deep crust, (ii) from interactions of fluids with sedimentary wall rocks and/or (iii) in overlying Permian piedmont basins containing, in places, coal seams. The event dealing with heterogeneous CO2-bearing fluids yielded constraints on pressure conditions of ore formation (100–270 bar) as well as on the clarification of some additional genetic aspects of the Příbram’s ores, including the reasons for the widespread dissolution of older vein fill, the possible re-cycling of some ore-forming components, pH changes, and occasionally observed carbon isotope shift due to CO2 degassing.

EIS study of Mimosa tenuiflora nanocontainers in a defective epoxy resin for the protection of low-carbon steel in a saline media

EIS study of Mimosa tenuiflora nanocontainers in a defective epoxy resin for the protection of low-carbon steel in a saline media

Bioaugmentation of halophilic consortium for degradation of 1,4 dioxane (1,4-DE) and treatment of cosmetic industrial wastewater in continuous stirred tank reactor under saline condition

The heterocyclic ether 1,4-Dioxane (1,4-DE) is a toxic by-product used widely in various industrial activities as a solvent or stabilizer. 1,4-DE was classified as a probable human carcinogen according to the United States Environmental Protection Agency (USEPA) due to its chemical and physical properties. Emerging pollutants in industrial wastewater is the major challenge for the operation of effluent treatment plant. The bioremediation of 1,4-DE is an effective approach to treat the industrial wastewater. The bacterial consortium was obtained from industrial sludge samples, Yanbu, Saudi Arabia and enriched in 1,4-DE supported basal salt saline medium. Biodegradation of 1,4-DE was studied at several concentrations ranging from 200 to 1200 mg/L. Complete mineralization of 1,4-DE from 200 to 800 mg/L was achieved in 4 to 8 days at 4% salinity. 1,4-DE utilization was studied at different salinity (4% and 6%), the results exhibited complete mineralization of 1,4-DE at 4 days and 6 days respectively. Increase in salinity to 8% displayed 92% degradation of 1,4-DE. Addition of yeast extract accelerated the biomass production correspondingly reduced the time required for biodegradation under saline condition. The bacterial consortium showed the ability to degrade 1,4-DE completely at various range of concentrations. Lab scale continuous stirred tank reactor (CSTR) was used to evaluate the industrial wastewater treatment efficacy of the bacterial consortium under saline condition. CSTR operated for 36 days displayed chemical oxygen demand (COD) removal and 1,4-DE degradation of 96% under saline condition. THF (Tetrahydrofuran) which accelerated the degradation process of 1,4-DE was completely degraded in 28 days. Bacterial analysis with high throughput sequencing technique confirmed the existence of bacterial strains like Ochrobactrum (45%), Marinobacter (21%), Stenotrophomonas (16%), Pseuodomonas (9%), Sphingomonas (4%), Bacillus (3.5%) and Sedimentibacter (1.5%).

Synthesis of hybrid organosilicon materials of various chemistries as efficient protective coatings for mild steels in NaCl media

This study focuses on optimizing the thermal, morphological, scratch resistance, and anti-barrier characteristics of newly developed hybrid sol-gel coatings. The coatings were formulated by varying the synthetic precursors and incorporating a clay additive. The hybrid coatings were prepared using a mixture of organosilane and zirconium propoxide precursors, and further modified with polydimethylsiloxane (PDMS) and Cloisite 20 A (C20A) clay additives. The coatings were applied onto mild steel substrates and their corrosion protection in 3.5 wt% NaCl solutions were evaluated through electrochemical and visual observation testing. Contact angle measurements revealed a hydrophobic nature of the developed coatings on the steel surfaces, primarily attributed to the presence of an organosilane precursor with a long C18-alkyl chain functionality in all formulations. Electrochemical testing data demonstrated that the coating formulation containing the polydimethylsiloxane precursor exhibited good corrosion protection. After 14 days of immersion in a saline medium, this sample exhibited impedance values higher than 106 Ω.cm2 and a low corrosion rate of 3.5 × 10−3 mpy, as determined by electrochemical impedance spectroscopy (EIS) and polarization testing, respectively. Morphological analyzes confirmed the homogeneous and integrated coating layer of this sample, which contributed to its enhanced corrosion protection. Furthermore, the inclusion of the Zr-propoxide precursor in a formulation containing only silane precursors demonstrated favorable effects on the desired coating properties. The hybrid sol-gel coatings exhibited excellent anti-barrier characteristics, which can be attributed to the formation of highly cross-linked Si-O-Si networks. Overall, the reported hybrid coating formulations offer promising alternatives to commercially available toxic conversion coatings, as they exhibit excellent anti-barrier properties and can be considered environmentally friendly.

Effects of curing temperature and addition of functionalized graphene oxide on corrosion barrier performance of phenol furfural polymer-amino phenolic resin composite

Phenol furfural polymer (PFP) blended amino phenolic resin (APR) and functionalized graphene oxide (FGO) dispersed PFP/APR polymer composite coatings were fabricated and evaluated their barrier performance on mild steel (MS) corrosion at different curing temperatures without using any conventional hardeners. The PFP was synthesized by condensation polymerization and blended with the prepared APR to get PFP/APR polymer composite. The GO was functionalized with 4-(trifluoromethyl) benzohydrazide (TFB) and dissipated in PFP/APR composite matrix. The synthesized materials were characterized by FT-IR, Raman, XRD, XPS, EDS, SEM and TEM techniques. The thermal stability of GO and FGO was analyzed using TGA. The fabricated composite materials were coated on MS surface and their surface morphology, anti-corrosion potential and hydrophobic character were evaluated by SEM, optical images, electrochemical impedance spectroscopy (EIS), salt spray analysis (SSA) and contact angle measurements (CA). At 70 °C curing temperature, the PFP/APR coating showed maximum coating resistance (Rc) of 1.39 × 105 Ω cm2 and charge transfer resistance (Rct) of 2.63 × 105 Ω cm2 on 60th day of immersion in 3.5 wt% NaCl solution. Addition of 0.2 wt% FGO into PFP/APR matrix reduced the ideal curing temperature to 50 °C and exhibited an admirable barrier performance even after 90 days of immersion in saline medium with a reliable Rc and Rct values of 1.24 × 105 Ω cm2, 1.93 × 105 Ω cm2 respectively, and coating capacitance (Qc) in the range of 10−9 F/cm2. The cross linking of resin and blockade of defects by nanofiller make the material highly durable and superior in extensive corrosive environment.

Biodegradation of the Antibiotic Doxycycline by Bacteria from the Gastrointestinal Tract of Cucurbit Beetles (Diabrotica speciosa)

Antibiotics can contaminate the environment as a result of improper disposal. The induction of doxycycline in the environment could give rise to lineages of the cucurbit beetle Diabrotica speciosa containing resistant endosymbiotic microorganisms, giving rise to bacterial strains capable of biodegrading these antibiotic residues. This work determined the relationship between the intestinal microbiota of D. speciosa and its ability to biodegrade an antibiotic. Bacterial strains of Enterobacter cloacae and Stenotrophomonas maltophila isolated from the gastrointestinal tract of D. speciosa were evaluated for the biodegradation of doxycycline. An analytical method for the extraction and quantification of doxycycline by high-efficiency liquid chromatography-ultraviolet detection (HPLC-UV) was developed and applied to monitor the biodegradation rates during bacterial growth for nutrient and nutrient-deficient media, both supplemented with the antibiotic. Degradation kinetics showed a decrease in antibiotic concentration after 96 h in saline medium, with recoveries of 63.1 and 87.7% for E. cloacae and S. maltophilia, respectively. Two degradation products were then identified and characterized from the liquid chromatography-high resolution mass spectrometry data after bioassays with E. cloacae. The gastrointestinal tract of insects such as D. speciosa can be a source of useful microbes for biotechnological processes such as the biodegradation of exogenous organic compounds in the environment.