Addition Of Sulfate Research Articles

Deep mantle cycle of chalcophile metals and sulfur in subducted oceanic crust

Understanding the subduction-driven recycling of economically important chalcophile metals (e.g., Cu, Au, Ag, and platinum-group elements, PGEs) and volatiles (e.g., sulfur) is critical for assessing models of ore formation. However, whether the sulfide remains stable in recycled altered oceanic crust (AOC) in the mantle is unclear, and the influence of AOC-derived metasomatic agents on the extraction efficiency of chalcophile elements from the deep mantle remains poorly understood. Here we report whole-rock Cu-Ag-Au-Re-PGEs of Cenozoic alkaline basalts at Hannuoba, eastern China, which were derived from the interaction of carbonated eclogite (recycled AOC)-derived melts with lithospheric peridotites. Volatile-rich primitive melts from carbonated eclogite are poor in strongly chalcophile metals (e.g., ∑PGE < 1 ng/g, Au < 1 ng/g, Cu < 30 μg/g). Remarkably, primitive melts show significant fractionation of elements with variable chalcophile affinities, such as lower Cu/Ag ratios than those in primitive mantle and MORBs. These features reflect the sequestration of these metals in residual mono-sulfide solid solution (MSS) during low-degree melting of the AOC in the deep mantle. Given the retention of sulfides in the AOC, partial melts derived from it are rich in sulfur but poor in strongly chalcophile metals. The Hannuoba alkaline melts scavenged some strongly chalcophile metals from peridotites (especially PGEs) during their ascent. However, this did not necessarily lead to the formation of chalcophile metal-enriched melts (e.g., Au < 1 ng/g and Cu < 60 μg/g). These processes appear to be common in eastern China, as evidenced by the low abundances of Cu and Au found in many primitive intraplate alkaline basalts. We propose that strongly chalcophile elements in subducted AOC are efficiently transported into, and stored in, the deep mantle, with a small proportion returning to the exosphere through volcanism. Moreover, the chalcophile metal-poor and volatile-rich melts of subducted AOC could also explain the addition of abundant sulfur (secondary sulfides), but limited chalcophile metals to the metasomatized mantle.

Comparative study between rocuronium and magnesium sulfate as adjuvants to local anesthetics for peribulbar block

Background &amp; Objective: Peribulbar anesthesia is frequently used in cataract surgeries. Compared to retrobulbar anesthesia, this approach is associated with less significant consequences. However, the prolonged onset of orbital akinesia and the frequent need for block replenishment are considered drawbacks. We aimed to investigate the impact of adding rocuronium and magnesium sulfate to a commonly used local anesthetic combination on the onset of corneal anesthesia and the degree of lid and globe akinesia during peribulbar block in ocular surgeries.&#x0D; Patients and Methods: This prospective double-blinded randomized study was conducted in the ophthalmic surgery operating theater, Ain Shams University Hospital from January 2019 to April 2020. We enrolled 75 patients from both sexes, with American Society of Anesthesiology (ASA) physical status I–III, ages 40-80 y, and an axial globe length less than or equal to 26 mm planned for cataract surgery under peribulbar block in the study following institutional ethical board approval and written informed patient consents. Patients were randomly divided into three groups, 25 patients per group, based on the drugs they received: Group O (control group): received local anesthetic + 0.9% normal saline (1 ml). Group M: received local anesthetic + magnesium sulphate 50 mg in normal saline. Group R: received local anesthetic + rocuronium at a dose of 0.06 mg/kg (maximum 5 mg) in normal saline.&#x0D; Results: Our study found statistically significant more rapid onset of action (mean time to start surgery) in rocuronium group (7.00 ± 1.22 min) than control group and magnesium sulfate group (9.00 ± 1.47 and 9.00 ± 1.15 min) respectively, (P &lt; 0.001); Moreover, no significant difference was noted between control group and magnesium sulfate group. In addition, no relevant difference was reported regarding duration of surgery between the groups.&#x0D; Conclusion: During cataract surgery, the addition of rocuronium to the local anesthetic mixture in the peribulbar nerve block has been found to enhance ocular akinesia and corneal anesthesia. Furthermore, the use of rocuronium demonstrated a significantly faster onset and shorter time needed to achieve the appropriate conditions to initiate the surgical procedure compared to the use of magnesium sulfate. Addition of magnesium sulfate showed good results regarding akinesia, corneal anesthesia and need for supplementary injections but it did not significantly fasten the onset of block and hence the time to start surgery.&#x0D; Key words: Cataract; Magnesium Sulfate; Peribulbar Block; Rocuronium&#x0D; Citation: Nagy M, Abo El-Ella S, El-Shafey MA, Helal AM, Zekry MR. Comparative study between rocuronium and magnesium sulfate as adjuvants to local anesthetics for peribulbar block. Anaesth. pain intensive care 2024;28(1):55−61; DOI: 10.35975/apic.v28i1.2157&#x0D; Received: February 18, 2023; Reviewed: July 30, 2023; Accepted: December 23, 2023

Effects of zinc supplementation from organic and inorganic sources on growth, blood biochemical indices, and intestinal microarchitecture in broilers

In poultry nutrition, zinc supplementation is typically achieved through the addition of zinc oxide or zinc sulfate to the feed. The alternative approach of organic sources utilizes an organic ligand to bind zinc (Zn), resulting in higher bioavailability. Thus, a study was conducted to assess and compare the impact of a methionine-complexed Zn versus an inorganic Zn on growth, blood biochemical profile, gut histomorphology, and fecal excretion of Zn in broilers. The experimental design included two treatments: the addition of a zinc amino acid complex or zinc oxide to the basal diet. The zinc amino acid complex was supplemented at a dose equivalent to the inorganic zinc (Zn-80), while the organic zinc was provided at levels of 20, 40, and 80 mg/kg to a total of 400 broilers. There were five treatments in total, and each treatment was replicated four times. Broilers supplemented with an organic form of Zn at the level of 80 mg/kg had significantly (p < 0.05) higher body weight gain and lower feed conversion ratio (F/G). Significantly (p < 0.05) higher Zn excretion was recorded in broilers supplemented with inorganic Zn supplementation. Significantly (p < 0.05) higher villus length and width, their ratio, and lower (p < 0.05) crypt depth were observed in birds supplemented with 80 mg/kg organic Zn. From the results of the present study, it was concluded that Zn from an organic source at the rate of 80 mg/kg was superior in terms of growth performance, intestinal histomorphology and less excretion of Zn to the environment in broilers.

Utilization of Hydroxyapatite-Chitosan-Bay Leaf Oil (Syzygium Polyanthum W.) as Antibacterial for Streptococcus Mutants

Dental caries is a disease that can damage hard tooth tissue caused by the activity of Streptococcus mutans bacteria. Streptococcus mutans bacteria are the leading cause of dental caries disease. Efforts to prevent dental caries can be made using toothpaste, but toothpaste cannot reach areas that are difficult to reach with a toothbrush. Another method that can be used is mouthwash. This study was developed with the active ingredient compound HAp-chitosan-bay leaf oil in mouthwash to have an antimicrobial effect to prevent dental caries. This study aimed to determine the chemical physics characteristics and antibacterial activity of mouthwash preparations based on hydroxyapatite-chitosan-bay leaf oil. In this study, the active ingredients hydroxyapatite-chitosan-bay leaf oil was used with variations in the concentration of bay leaf oil, namely 0.5, 1.5, and 2.5 %. FT-IR characterization showed the presence of OH, N-H, CH, C=O, C=C, C-O, and PO43- functional groups. The pH test on the mouthwash showed compliance with the quality standard for mouthwash pH, which has a pH range of 5-7. The homogeneity test results in the mouthwash preparation showed no sediment or separation. Antibacterial activity testing showed that the HAp-chitosan-bay leaf oil mouthwash preparation inhibited the growth of Streptococcus mutans bacteria. The inhibition zone in the strong category with an average of 12.75 mm was shown in the HAp-chitosan-bay leaf oil mouthwash preparation formulation with a concentration of 2.5% bay leaf oil with the addition of sodium lauryl sulfate (SLS).

The influence of polydiethylsiloxane (PDES) concentration on the tribolfilm of chlorophenyl silicone oil (CPSO) under high-temperature lubrication

As pivotal structural component, steels operating at high temperatures play a vital role in promoting the development of advanced equipment technology. Enduring and efficient lubricants are critical bottleneck for the construction of high-temperature frictional subsystems. Polydiethylsiloxane oil (PDES) significantly reduces the coefficient of friction (COF) (9.80–16.74 %) and wear rate (28.95–54.59 %) in the Si3N4–8Cr4Mo4V system without sulfur and phosphorus anti-wear additives at 250 °C. With only 1 wt% PDES, there is a remarkable 28.95 % wear rate reduction in the Si3N4–8Cr4Mo4V frictional system. The enhanced lubrication performance come from the Si–O tribofilm at lower PDES concentrations (1–15 wt%). Once exceeding a PDES concentration of 30 wt%, the as-formed Si–O tribofilm transitions to a Fe–Mo compound film, exhibiting superior friction reduction and wear resistance properties.

Insights into sulfur cycling contribution to nitrogen removal in sulfur autotrophic denitrification combined microbial electrochemical denitrification

In the face of increasing discharge standards, sulfur autotrophic denitrification (SAD) is gradually applied for deep nitrogen removal of electron-donor-deficient waters. However, the product sulfate induces secondary pollution in the effluent, and the proton consumption from alkalinity is detrimental to the stable operation of the system. In this study, a sulfur autotrophic denitrification coupled with microbial electrochemical denitrification system (S-MED) is proposed to reduce the addition of inorganic sulfur, alleviating nitrite accumulation, while enabling the system to self-sustain at a neutral pH. The S-MED system that was operated under the applied potential of −0.5 V achieved a nitrate removal of 97.5 ± 1.57 % and a total nitrogen removal of 90.3 ± 4.27 %, which were 14.6 % and 68.0 % higher than the SAD systems in control under the S/N molar ratio of 0.8. The nitrite accumulation rate was reduced by 69.1 % compared to SAD. The effluent sulfate concentration was also reduced to 5.8 mg/mg-N TN removal. The electrochemically active denitrifying bacterium Thiobacillus was enriched in the coupled system, and the copy numbers of functional genes of narGHI, napAB, and nirK involved in denitrification were increased. According to the microbial analysis and electrochemical characteristics, it suggested that S2- might be generated from sulfate with the presence of electrodes, enabling the cycling of sulfur, providing mobile electron carriers for denitrification, thus allowing bacteria to conduct denitrification by indirectly obtaining electrons from the electrode.

The role of bidirectional communication between the adipokines and the endogenous opioid system in an experimental mouse model of colitis-associated colorectal cancer.

Colorectal cancer (CRC) is one of the leading causes of death globally. Multiple factors may contribute to the pathogenesis of CRC, including the abnormalities in the functioning of the endogenous opioid system (EOS) or adiponectin-related signaling. The aim of our study was to evaluate if differences in the expression of opioid receptors (ORs) influence the development of CRC and if modulation of adiponectin receptors using AdipoRon, a selective AdipoR1 receptor agonist, affects colorectal carcinogenesis. Naltrexone, an opioid receptor antagonist, was injected intraperitoneally every second day for 2weeks, at the dose of 1mg/kg in healthy Balb/C mice to induce changes in ORs expression. CRC was induced by a single intraperitoneal injection of azoxymethane (AOM) and the addition of dextran sodium sulfate (DSS) into drinking water in three-week cycles. The development of CRC was assessed using macro- and microscopic scoring and molecular analysis (RT qPCR, ELISA)after 14 weeks. Naltrexone significantly increased the mRNA expression of Oprm1, Oprd1, and Oprk1 in the mouse colon and in the brain (non-significantly). The pretreatment of mice with naltrexone aggravated the course of CRC (as indicated by tumor area, colon thickness, and spleen weight). The level of circulatory adiponectin was lowered in mice with CRC and increased in the colon as compared with healthy mice. The β-endorphin level was increased in the plasma of mice with CRC and decreased in the colon as compared to healthy mice. AdipoRon, AdipoR1 agonist, worsened the CRC development, and pretreatment with naltrexone enhanced this negative effect in mice. CRC did not affect the expression of the Adipor1 gene, but the Adipor1 level was increased in mice pretreated with naltrexone (AOM/DSS and healthy mice). AdipoRon did not influence the expression of opioid receptors at the mRNA level in the colon of mice with CRC. The mRNA expression of Ptgs2, Il6, Nos2, Il1b, Il18, Gsdmd, and Rela was increased in mice with CRC as compared to the healthy colon. AdipoRon significantly decreased mRNA expression of Ptgs2, Il6, Il1b, and Il18 as compared to CRC mice. EOS and adiponectin-related signaling may play a role in the pathogenesis of CRC and these systems may present some additivity during carcinogenesis.

Assessing above and belowground recovery from ammonium sulfate addition and wildfire in a lowland heath: mycorrhizal fungi as potential indicators

Atmospheric pollution containing soil‐nitrifying ammonium sulfate ((NH₄)₂SO₄) affects semi‐natural ecosystems worldwide. Long‐term additions of (NH₄)₂SO₄ to nitrogen (N)‐limited habitats, including heathlands, increase climate stress affecting recovery from wildfires. Although heathland vegetation largely depends on ericoid mycorrhizal fungi (ErM) to access soil N, we lack detailed understanding of how prolonged exposure to (NH₄)₂SO₄ may alter ErM community composition and host plants' reliance on fungal partners following wildfire and affect recovery. Simulation of atmospheric pollution ((NH₄)₂SO₄) occurred bi‐weekly for 5 years after a 2006 wildfire in a UK heathland. Ten years after treatments ceased, we measured vegetation structure, lichen and lichen photobiont composition, soil characteristics, ErM colonization, ErM diversity in roots and soil, and assessed ErM potential as novel recovery indicators. Heather height and density, and moss groundcover, were greater in N‐enriched plots. Lichen community indices showed significant treatment effects, but without differences in photobionts. Soil pH and Mg were significantly lower in treated plots while soil cation exchange capacity was significantly higher. There were no detectable differences in ErM composition and keystone ErM taxa between control and treated plots. Soil carbon stock measures were variable. Our results indicate atmospheric pollution following fire can have significant lingering effects above‐ and belowground. ErM diversity and root colonization were not assessed in the original N‐addition experiment; we advocate for their inclusion in future studies as an integral part of the recovery assessment toolkit. We show that mycorrhizal fungi diversity is a viable ecological tool and summarize key steps for ErM identification.

Microbial responses to elevated temperature: Evaluating bentonite mineralogy and copper canister corrosion within the long-term stability of deep geological repositories of nuclear waste

Deep Geological Repositories (DGRs) consist of radioactive waste contained in corrosion-resistant canisters, surrounded by compacted bentonite clay, and buried few hundred meters in a stable geological formation. The effects of bentonite microbial communities on the long-term stability of the repository should be assessed. This study explores the impact of harsh conditions (60 °C, highly-compacted bentonite, low water activity), and acetate:lactate:sulfate addition, on the evolution of microbial communities, and their effect on the bentonite mineralogy, and corrosion of copper material under anoxic conditions. No bentonite illitization was observed in the treatments, confirming its mineralogical stability as an effective barrier for future DGR. Anoxic incubation at 60 °C reduced the microbial diversity, with Pseudomonas as the dominant genus. Culture-dependent methods showed survival and viability at 60 °C of moderate-thermophilic aerobic bacterial isolates (e.g., Aeribacillus). Despite the low presence of sulfate-reducing bacteria in the bentonite blocks, we proved their survival at 30 °C but not at 60 °C. Copper disk's surface remained visually unaltered. However, in the acetate:lactate:sulfate-treated samples, sulfide/sulfate signals were detected, along with microbial-related compounds. These findings offer new insights into the impact of high temperatures (60 °C) on the biogeochemical processes at the compacted bentonite/Cu canister interface post-repository closure.

Utilization of Tamarind Seeds Extract as a Natural and Sustainable Fabric Dye

This research focuses on the use of tannin components in tamarind seed coats as a mordant and natural dye in cotton fabrics. Tannins were extracted from the tamarind seed coat by boiling method and then the tannin content was determined. The tannin extract was then used as a natural mordant with the addition of metallic copper sulfate (CuSO4) mordant. Tannin extract is also used as a dye on fabrics with the addition of sodium sulfate (NaSO4). The color strength of the tannins in the fabric was analyzed using a spectrophotometer from the rinse water. The results showed that the cloth that had been given the mordant had a stronger color strength than the cloth without the mordant. The use of mordant was varied at concentrations of 5, 10, 15, 20, and 25%-owf. The results of the analysis showed the most optimum tannin concentration at 15%-owf. The concentration of tannin used in the coloring process was also varied at concentrations of 5, 10, 15, 20, and 25%-owf. The results of the analysis show that the concentration of tannin used in the dye does not affect the strength of the color, but only affects the brightness of this color.

Effect of inorganic anions on hydrothermal removal of impurities Fe/Al from Cu-bearing polymetallic leachate.

Hydrometallurgy recycling of heavy metals from electroplating sludge is of hot spot in recent decades. Such recycling was tedious in the separation of impure Fe/Al prior to heavy metals from acid leachate after sludge dissolution. Herein, a facile hydrothermal route was developed to separate Fe/Al from Cu-bearing leachate. The results showed that when the leachate was directly hydrothermally treated at 160°C in the presence of nitrate and ethanol, Al/Cu were stable in the leachate, but nearly 100% Fe was removed as hematite nanoparticles. With the addition of chloridion, the removal efficiencies of Fe/Al/Cu did not change apparently, but the corresponding precipitate was akageneite, not hematite. By replacing chloridion with sulfate, nearly 100% Fe and 98.6% Al were separated as natrojarosite/natroalunite block, while the Cu loss was only 1.7%. However, with the supplementary of phosphate, the Fe/Al removal achieved nearly 100%, but the Cu removal also achieved by 92.6%. The thermodynamic analysis showed that Cu was precipitated rapidly via the phosphate/Cu oxyhydroxide route by adding phosphate but removed slightly via the coordination route on the Fe/Al precipitates with the addition of nitrate, chloridion, and sulfate. In summary, Fe was effectively separated as hematite, akageneite, natrojarosite, and phosphate halite, in the presence of nitrate, chloridion, sulfate, and phosphate, separately. But the removal of Al as natroalunite and AlPO4 only started by adding sulfate and phosphate, respectively. Such results enabled a short hydrometallurgy process to effectively recycle heavy metals from electroplating sludge.

Elimination of methylmercury production potential in excessive sludge in wastewater treatment plants by sulfur addition

Mercury ions (Hg(II)) in wastewater can accumulate and transform into the highly neurotoxic methylmercury (MeHg) in activated sludge. The release of MeHg can have severe environmental consequences, making the treatment of MeHg-contaminated sludge a pressing concern. In this study, we found that all the collected activated sludge samples, from different wastewater treatment plants in four cities, had the potential for Hg methylation. The Hg-methylating capacity reached a maximum level of 0.70–0.92 μg/g volatile suspended solids after 48 h of exposure to 5 μg/L Hg(II) and showed an average MeHg production rate of 4.8±0.5%. Accordingly, a sludge treatment method involving the addition of elemental sulfur (S0) for a short-term or long-term duration (3 or 180 days, respectively) was proposed. The results demonstrated that this treatment approach effectively mitigated and potentially eliminated MeHg formation by simultaneously reducing Hg bioavailability and Hg-methylating bioactivity. We found that bioavailable Hg(II) ions were converted to a secondary phase similar to insoluble HgS after S0 addition treatment, leading to a decrease in Hg bioavailability in sludge. The enhancement of Hg and extracellular polymeric substances (EPS) complexation via the increasing amount of thiol groups in EPS also reduced the Hg bioavailability after the long-term treatment. Furthermore, the long-term S0 addition significantly reduced the abundance of Hg-methylators with hgcA gene and promoted the growth of Hg-reducers with merA gene, which ensured the complete elimination of MeHg production potential of the excessive activated sludge. Our findings demonstrated that the proposed S0-addition sludge treatment is a promising and safe biotechnology for treating Hg-contaminated sludge. This approach has the potential to contribute significantly to the mitigation of MeHg pollution within environmental contexts.

Disentangling the effects of sulfate and other seawater ions on microbial communities and greenhouse gas emissions in a coastal forested wetland.

Seawater intrusion into freshwater wetlands causes changes in microbial communities and biogeochemistry, but the exact mechanisms driving these changes remain unclear. Here we use a manipulative laboratory microcosm experiment, combined with DNA sequencing and biogeochemical measurements, to tease apart the effects of sulfate from other seawater ions. We examined changes in microbial taxonomy and function as well as emissions of carbon dioxide, methane, and nitrous oxide in response to changes in ion concentrations. Greenhouse gas emissions and microbial richness and composition were altered by artificial seawater regardless of whether sulfate was present, whereas sulfate alone did not alter emissions or communities. Surprisingly, addition of sulfate alone did not lead to increases in the abundance of sulfate reducing bacteria or sulfur cycling genes. Similarly, genes involved in carbon, nitrogen, and phosphorus cycling responded more strongly to artificial seawater than to sulfate. These results suggest that other ions present in seawater, not sulfate, drive ecological and biogeochemical responses to seawater intrusion and may be drivers of increased methane emissions in soils that received artificial seawater addition. A better understanding of how the different components of salt water alter microbial community composition and function is necessary to forecast the consequences of coastal wetland salinization.

Influence of Copper Sulphate on Anther Culture for Haploid Production in African Marigold (Tagetes erecta L.)

The present study was carried out to improve the yield of androgenesis in marigold, for which copper sulfate was tested during the pretreatment of anther culture at various concentrations. The best results were obtained when copper sulfate was added at 15 µM and 20 µM. With the addition of copper sulphate at 20 µM, the percent of responding anthers increased from 81.6 to 92.2 %. While. percent caulogenesis increased from 66.8 to 78.4 % with copper sulphate concentration of 15 µM. With the same concentration of copper sulphate (15 µM), the number of shoot buds per anther increased from 7.4 to 9.6 and the number of regenerants per anther increased from 5.8 to 8.6. The positive influence of copper sulphate may be due to an increase in the microspore survival during anther culture.

Underlying the inhibition mechanisms of sulfate and lincomycin on long-term anaerobic digestion: Microbial response and antibiotic resistance genes distribution

This study evaluated the resilience of a long-term anaerobic treatment system exposed to sulfate, lincomycin (LCM) and their combined stress. LCM was found to impede anaerobic propionate degradation, while sulfate for restraining methanogenic acetate utilization. The combined stress, with influent LCM of 200 mg/L and sulfate of 1404 mg/L, revealed severer inhibition on anaerobic digestion than individual inhibition, leading to 73.9 % and 38.5 % decrease in methane production and sulfate removal, respectively. Suppression on propionate-oxidizing bacteria like unclassified_f__Anaerolineae and unclassified_f__Syntrophaceae further demonstrated LCM's inhibitory effect on propionate degradation. Besides, the down-regulation of genes encoding dissimilatory sulfate reduction enzymes caused by LCM triggered great inhibition on sulfate reduction. A notable increase in ARGs was detected under sulfate-stressed condition, owing to its obvious enrichment of tetracycline-resistant genes. Genera including unclassified_f__Syntrophaceae, unclassified_f__Geobacteraceae and unclassified_f__Anaerolineaceae were identified as dominant host of ARGs and enriched by sulfate addition. Overall, these results could provide the theoretical basis for further enhancement on anaerobic digestion of pharmaceutical wastewater containing sulfate and lincomycin.

Sulfide Inclusions in an Al‐Killed Nonoriented Electrical Steel with Lanthanum Addition

Herein, laboratory experiments are conducted to evaluate the effect of sulfur and lanthanum content in the steel on the modification of inclusions. The amount, composition, morphology, and size of nonmetallic inclusions in the steel are observed using an automatic scanning electron microscope. Results show that as the lanthanum content in the steel increased from 0 to 72 ppm, the inclusions in the steel with 12 ppm sulfur are modified in the following order: Al2O3–CaO–MgO → LaAlO3 → LaAlO3–La2O2S → La2O2S. Similarly, when the sulfur content is 27 ppm, inclusions transformed in the order of Al2O3–CaO–MgO → LaAlO3 → LaAlO3–La2O2S → La2O2S → La2O2S–LaxS → LaxS as the lanthanum content increases from 0 to 150 ppm. Thermodynamic analysis using FactSage based on a private database is employed to reveal the mechanism for the modification of inclusions. Additionally, a kinetic model is established to study the transformation rate of inclusions in the steel after the addition of lanthanum and sulfur. Liquid Al2O3–CaO–MgO inclusions disappear after 800 s when the steel contains 12 ppm sulfur and 12 ppm lanthanum. The composition of inclusions is 53%LaAlO3–47%La2O2S at 1800 s, while it is 100%La2O2S and 80%La2O2S–18%LaxS–2%CaS when the lanthanum content is 33 and 72 ppm, respectively.

Catalytic insights into perhydro-benzyltoluene dehydrogenation: Probing surface characteristics revealed by DRIFTS study

The enhancement of dehydrogenation activity in liquid organic hydrogen carriers (LOHC), such as perhydro-benzyltoluene (H12-BT), has been attributed to the addition of various promoters and support modifications into platinum (Pt)-based heterogeneous catalysts. Comprehensive understanding of surface sites predominantly catalyzing the dehydrogenation process is crucial for further enhancing catalytic performance. In this contribution, an in-depth quantitative CO diffuse reflectance infrared Fourier transform spectroscopy (CO-DRIFTS) study on Pt-based catalysts with varying contents of sulfur, known to be effective in dehydrogenation reactions, is performed to unveil the active sites involved in the H12-BT dehydrogenation. Furthermore, while challenges associated with the adsorption step of reactants and products potentially deteriorate catalytic activity, these processes remain open questions for H12-BT dehydrogenation. To shed light on these aspects, we conducted in situ DRIFTS experiments utilizing H12-BT and H0-BT, its dehydrogenated counterpart, to determine the adsorption strength between these molecules and the different catalyst surfaces, influenced by the electron-deficiency effect due to the addition of sulfur. Additionally, our study investigates the correlation between sulfur-induced catalyst surface characteristics and the formation of methane through the demethylation process.

Sulfur — a potential additive to increase the efficacy of copper-based fungicides against grapevine downy mildew

Control of downy mildew on grapevines in organic viticulture in Europe is mainly based on using copper-based fungicides. However, the effect of these agents is often insufficient to prevent losses when infestation pressure is high. The addition of sulfur, which is primarily used to control powdery mildew, improves the effect of copper on downy mildew. In three out of five trial years, sulfur had a clear positive effect when it was added during spray treatments against Plasmopara viticola, the causal agent of downy mildew on grapevines. This was evident mainly in the fruits; no further positive effect on the leaves was evident. In addition, the present study shows that copper-based fungicides are effective on leaves but have a rather poor effect on grapevine fruit. Furthermore, the study demonstrates that the effect of copper is significantly worse than that of the chemical synthetic contact fungicide folpet.

Effects of rattan fiber length variation on mechanical properties, characterization, and microstructure of concrete

The study aimed to test how variations in fiber length affect the behavior of microstructures in concrete, as well as to characterize and analyze their mechanical properties. This research covers several specific objectives, including understanding the influence of different fiber lengths on micro and macrostructural aspects of concrete, assessing the mechanical properties of reinforced concrete with fibers of various lengths, and examining the relationship between fiber length and the mechanical performance of concrete. The results showed that the addition of rattan fibers in concrete can increase or even reduce tensile strength depending on the length of the fibers and their material characteristics. The addition of rattan fibers with a length of 30 mm results in a significant increase in tensile strength, while longer or shorter fiber lengths do not yield equally favorable results. Analysis of the chemical composition of concrete shows that the elements oxygen (O), calcium (Ca), and silicon (Si) predominate, with the addition of carbon (C), iron (Fe), aluminum (Al), magnesium (Mg), and Sulphur (S) elements in concrete with rattan fibers. Morphological observations using SEM on concrete, both with fibers and without fibers, provide an in-depth understanding of the structure of concrete surfaces microscopically

Effect of i.v. Magnesium Sulphate versus i.v. Dexamethasone on Intraoperative Haemodynamic and Postoperative Analgesia after Spinal Anaesthesia in Lower Limb Surgeries: A Randomised Clinical Study

Introduction: Intrathecal adjuvants have gained favour in recent years with the goal of extending the duration of a block. Among these, Dexamethasone possesses anti-inflammatory and analgesic action and can be given as an adjuvant to local anaesthetics to enhance the efficacy of regional anaesthesia, as well as to decrease the intensity of shivering. The addition of Magnesium sulphate (MgSO4 ) to spinal anaesthesia helps in improving postoperative analgesia in an orthopaedic setting. Aim: To compare the effects of Intravenously (i.v.) MgSO4 and i.v. dexamethasone on intraoperative haemodynamics, the time to achieve dermatome T10 intraoperatively, and to compare postoperative Visual Analogue Scale (VAS) scores between the two groups at 1, 3, 6, 12, and 24 hours after surgery. Materials and Methods: This randomised clinical trial was conducted, and patients were randomly divided into two groups. Group M (n=40): MgSO4 40 mg/kg given 15 minutes before spinal anaesthesia in 100 mL normal saline infusion i.v. Group D (n=40): Dexamethasone 8 mg given 15 minutes before spinal anaesthesia in 100 mL normal saline infusion i.v. The parameters assessed included haemodynamic parameters, time to achieve dermatome T10 intraoperatively, postoperative VAS score at 1, 3, 6, 12, and 24 hours after surgery, and any side-effects like sedation, respiratory depression, nausea, vomiting, pruritus, urinary retention, bradycardia, and hypotension. Statistical testing was conducted using the statistical software Statistical Package for Social Sciences (SPSS) 28.0. Results: There was no significant difference in demographic variables (age and gender) between the two groups (p-value&gt;0.05). However, the decrease in mean heart rate, Systolic Blood Pressure (SBP), Diastolic Blood Pressure (DBP), and Mean Arterial Blood Pressure (MAP) was greater in group D compared to group M at different time intervals (p-value&lt;0.05). Additionally, dermatome level T10 was achieved earlier in group D by approximately two minutes compared to group M (6.95±0.39 minutes versus 5.03±0.16 minutes, respectively, p-value&lt;0.001). Conclusion: An i.v. infusion of 8 mg dexamethasone in 100 mL normal saline was more effective compared to an i.v. infusion of 40 mg/kg MgSO4 in terms of achieving more stable haemodynamics intraoperatively and achieving the T10 dermatome level earlier.