Experimentally derived partitioning coefficients of carbamazepine and sulfadiazine in landfill refuse-leachate phase: Effects of refuse and leachate properties.

Pharmaceuticals have been detected at high concentrations in landfill leachate and refuse, which may pose potential long-term environmental impacts. The interaction of pharmaceuticals between leachate and refuse contributes to their retention through in situ sorption, thereby mitigating this impact. However, limited efforts have been made to describe the distribution characteristics of pharmaceuticals in the refuse-leachate phase. In this study, two refuse and three leachate samples were used to obtain partitioning coefficients (Kd) for two typical pharmaceuticals, carbamazepine (CBZ) and sulfadiazine (SD), with campus soil as a comparison. Landfill refuse exhibited higher Kd values (12.36 ± 0.90 and 19.76 ± 1.96 mL/g for CBZ and 1.90 ± 0.34 and 6.27 ± 0.58 mL/g for SD in two samples, respectively) than campus soil (3.73 ± 1.31 mL/g for CBZ and 0.81 ± 0.26 mL/g for SD), influenced by refuse properties such as higher organic matter (OM) content and specific surface area (SSA). The influence of leachate pH on Kd values depended on the electrostatic interaction between the species of target pollutants and negatively charged refuse. The effect of humic acid (HA) was related to its binding with target pollutants in solution and its competition with them for sorption sites. Electrostatic repulsion, hydrogen bonding and π-π interaction were the proposed mechanisms in SD sorption on refuse, while hydrogen bonding participated in the sorption of CBZ. The results will help aid the understanding of the distribution of pharmaceuticals in the refuse-leachate system and improve corresponding management strategies.

The mechanism differences between sulfadiazine degradation and antibiotic resistant bacteria inactivation by iron-based graphitic biochar and peroxydisulfate system.

In this study, the activation of peroxydisulfate (PS) by K2FeO4-activation biochar (KFeB) and acid-picking K2FeO4-activation biochar (AKFeB) was investigated to reveal the mechanism differences between iron site and graphitic structure in sulfadiazine (SDZ) degradation and ARB inactivation, respectively. KFeB/PS and AKFeB/PS systems had similar degradation property towards SDZ, but only KFeB/PS system showed excellent bactericidal property. The mechanism study demonstrated that dissolved SDZ was degraded through electron transfer pathway mediated by graphitic structure, while suspended ARB was inactivated through free radicals generated by iron-activated PS, accompanied by excellent removal on antibiotic resistance genes (ARGs). The significant decrease in conjugative transfer frequency indicated the reduced horizontal gene transfer risk of ARGs after treatment with KFeB/PS system. Transcriptome data suggested that membrane protein channel disruption and adenosine triphosphate synthesis inhibition were key reasons for conjugative transfer frequency reduction. Continuous flow reactor of KFeB/PS system can efficiently remove antibiotics and ARB, implying the potential application in practical wastewater purification. In conclusion, this study provides novel insights for classified and collaborative control of antibiotics and ARB by carbon-based catalysts driven persulfate advanced oxidation technology.

Efficient peroxymonosulfate activation by nanoscale zerovalent iron for removal of sulfadiazine and sulfadiazine resistance bacteria: Sulfidated modification or not.

Whether it's necessary to extra chemical synthesis steps to modify nZVI in peroxymonosulfate (PMS) activation process are worth to further investigation. The 56 mg/L nZVI/153.65 mg/L PMS and 56 mg/L sulfidated nZVI (S-nZVI) (S/Fe molar ratio = 1:5)/153.65 mg/L PMS) processes could effectively attain 97.7% (with kobs of 3.7817 min-1) and 97.0% (with kobs of 3.4966 min-1) of the degradation of 20 mg/L sulfadiazine (SDZ) in 1 min, respectively. The nZVI/PMS system could quickly achieve 85.5% degradation of 20 mg/L SDZ in 1 min and effectively inactivate 99.99% of coexisting Pseudomonas. HLS-6 (5.81-log) in 30 min. Electron paramagnetic resonance tests and radical quenching experiments determined SO4•-, HO•, 1O2 and O2•- were responsible for SDZ degradation. The nZVI/PMS system could still achieve the satisfactory degradation efficiency of SDZ under the influence of humic acid (exceeded 96.1%), common anions (exceeded 67.3%), synthetic wastewater effluent (exceeded 90.7%) and real wastewater effluent (exceeded 78.7%). The high degradation efficiency of tetracycline (exceeded 98.9%) and five common disinfectants (exceeded 96.3%) confirmed the applicability of the two systems for pollutants removal. It's no necessary to extra chemical synthesis steps to modify nZVI for PMS activation to remove both chemical and biological pollutants.

The healing effect of a mixture of Arnebia euchroma and animal fat on burn wounds in rats in comparison with sulfadiazine.

OBJECTIVE: Thermal burn is a serious cause of morbidity and mortality that affects millions of people worldwide. The aim of this experimental study was to investigate the efficacy of Arnebia euchroma (AE) to treat burn wounds in a rat model. METHOD: A total of 80 male rats (200-250g) were shaved over the back of the neck (2×3cm2) and a second-degree burn wound was induced at this site under general anaesthesia. The rats were then randomly assigned to one of four groups (each n=20) and the burns were treated daily for 14 days as follows: (1) dressed with animal fat; (2) dressed with sulfadiazine; (3) dressed with a mixture of AE and animal fat; (4) no treatment (control). Five rats from each group were sacrificed on days 3, 5, 9 and 14 post-burn and the wounds were evaluated histologically and immunohistochemically for the expression of interleukin (IL)-1 and IL-6. RESULTS: There was a significant increase at day 3 and decrease on day 5 samples for the expression of IL-1 in the AE plus fat group and IL-6 in the AE plus fat and sulfadiazine groups, compared to the control and fat treatment groups, respectively. Both AE plus fat and sulfadiazine treatments reduced inflammation and granulation tissue formation by day 5 post-burn, while re-epithelialisation commenced by day 9 post-burn. In addition, burns treated with AE plus fat exhibited keratinised epidermis, associated with regular collagen fibres, compared to moderately dense collagen fibres without vascularisation in the sulfadiazine group. CONCLUSION: These findings suggested that AE plus fat was superior to sulfadiazine in enhancing burn wound healing in rats.

Hemoadsorption and Coagulation Systemic Rebalance in Patients Undergoing Nonelective Cardiac Surgery and Treated with Antithrombotics.

INTRODUCTION: Insufficient withdrawal duration of antithrombotics leads to excessive bleeding after major surgery. We hypothesize that intraoperative hemoadsorption (HA) can reduce postoperative allogeneic transfusion requirements and excessive bleeding events (EBE), without an increase in ischemic/thromboembolic events (ITE) in patients who have taken antithrombotics and undergone nonelective cardiac surgery. METHODS: A total of 460 patients admitted to our hospital from 2018 to 2022 were included in this study and divided into two groups: HA and non-HA. Because of the risk of bias due to differences in antithrombotic type, withdrawal duration, or basic coagulation function, propensity score matching was used for analyses. RESULTS: Out of 154 cases in the HA group, 144 pairs were successfully matched. No HA safety events such as hemolysis, hypotension, or device failure occurred. After matching, the two groups were found to be comparable in preoperative antithrombotic type, withdrawal duration, platelets and coagulation function, and demographic and perioperative characteristics. Although the HA group did not have a reduced incidence of EBE, this group exhibited significant decreases in the transfusion rate and volume, the incidence of ITE, acute kidney injury, and central nervous system injury. CONCLUSIONS: For patients who have undergone nonelective cardiac surgery and taken antithrombotics, HA can simply and safely rebalance the postoperative coagulation system and have associations with reduced transfusion and postoperative ITE.

Synergistic effects of trace sulfadiazine and corrosion scales on disinfection by-product formation in bulk water of cast iron pipe.

The effects of trace sulfadiazine (SDZ) and cast-iron corrosion scales on the disinfection by-product (DBP) formation in drinking water distribution systems (DWDSs) were investigated. The results show that under the synergistic effect of trace SDZ (10 µg/L) and magnetite (Fe3O4), higher DBP concentration occurred in the bulk water with the transmission and distribution of the drinking water. Microbial metabolism-related substances, one of the important DBP precursors, increased under the SDZ/Fe3O4 condition. It was found that Fe3O4 induced a faster microbial extracellular electron transport (EET) pathway, resulting in a higher microbial regrowth activity. On the other hand, the rate of chlorine consumption was quite high, and the enhanced microbial EET based on Fe3O4 eliminated the need for microorganisms to secrete excessive extracellular polymeric substances (EPS). More importantly, EPS could be continuously secreted due to the higher microbial activity. Finally, high reactivity between EPS and chlorine disinfectant resulted in the continuous formation of DBPs, higher chlorine consumption, and lower EPS content. Therefore, more attention should be paid to the trace antibiotics polluted water sources and cast-iron corrosion scale composition in the future. This study reveals the synergistic effects of trace antibiotics and corrosion scales on the DBP formation in DWDSs, which has important theoretical significance for the DBP control of tap water.

Mechanism and synergistic effect of sulfadiazine (SDZ) and cadmium toxicity in spinach (Spinacia oleracea L.) and its alleviation through zinc fortification.

Cadmium (Cd) and antibiotic's tendency to accumulate in edible plant parts and fertile land is a worldwide issue. The combined effect of antibiotics and heavy metals on crops was analyzed, but not mitigation of their toxicity. This study investigated the potential of zinc oxide nanoparticles (ZnO NPs) to alleviate the SDZ and Cd toxicity (alone/combined) to promote spinach growth. Results revealed that the ZnO 200 mg L-1 spray decreased the malondialdehyde (MDA) 14%, hydrogen peroxide (H2O2) 13%, and electrolyte leakage (EL) 7%, and increased the superoxide dismutase (SOD) 8%, peroxidase (POD) 25%, catalase (CAT) 39% and ascorbate peroxidase (APX) 12% in spinach leaves under combined SDZ+Cd (25 mg Kg-1 +50 mg Kg-1) stress compared to ZnO 100 mg L-1 spray. Likewise, ZnO NPs 200 mg L-1 spray enhanced the zinc (Zn) 97%, iron (Fe) 86%, magnesium (Mg) 35%, manganese (Mn) 8%, and potassium (K) 23% in shoots under combined SDZ+Cd (25 mg Kg-1 +50 mg Kg-1) stress compared to ZnO 100 mg L-1 spray. Further, ZnO 200 mg L-1 spray reduced Cd uptake in roots by 9% and shoots 15% under combined SDZ+Cd (25 mg Kg-1 +50 mg Kg-1) stress compared to ZnO 100 mg L-1. Overall, ZnO NPs alleviated the SDZ and Cd toxicity and enhanced spinach growth in all treatments.

Visible light-driven photocatalysts, quantum chemical calculations, ADMET-SAR parameters, and DNA binding studies of nickel complex of sulfadiazine.

A 3D-supramolecular nickel integrated Ni-SDZ complex was synthesized using sodium salt of sulfadiazine as the ligand and nickel(II) acetate as the metal salt using a condensation process and slow evaporation approach to growing the single crystal. The metal complex was characterized for its composition, functional groups, surface morphology as well as complex 3D structure, by resorting to various analytical techniques. The interacting surface and stability as well as reactivity of the complex were carried out using the DFT platform. From ADMET parameters, human Intestinal Absorbance data revealed that the compound has the potential to be well absorbed, and also Ni-SDZ complex cannot cross the blood-brain barrier (BBB). Additionally, the complex's DNA binding affinity and in-vivo and in-vitro cytotoxic studies were explored utilizing UV-Vis absorbance titration, viscosity measurements, and S. pombe cells and brine shrimp lethality tests. In visible light radiation, the Ni-SDZ complex displayed exceptional photo-degradation characteristics of approximately 70.19% within 70 min against methylene blue (MB).

Cortical Reorganization After Optical Alignment in Strabismic Patients Outside of Critical Period.

Purpose: To measure visual crowding, an essential bottleneck on object recognition and reliable psychophysical index of cortex organization, in older children and adults with horizontal concomitant strabismus before and after strabismus surgery. Methods: Using real-time eye tracking to ensure gaze-contingent display, we examined the peripheral visual crowding effects in older children and adults with horizontal concomitant strabismus but without amblyopia before and after strabismus surgery. Patients were asked to discriminate the orientation of the central tumbling E target letter with flankers arranged along the radial or tangential axis in the nasal or temporal hemifield at different eccentricities (5° or 10°). The critical spacing value, which is the minimum space between the target and the flankers required for correct discrimination, was obtained for comparisons before and after strabismus surgery. Results: Twelve individuals with exotropia (6 males, 21.75 ± 7.29 years, mean ± SD) and 15 individuals with esotropia (6 males, 24.13 ± 5.96 years) participated in this study. We found that strabismic individuals showed significantly larger critical spacing with nasotemporal asymmetry along the radial axis that related to the strabismus pattern, with exotropes exhibiting stronger temporal field crowding and esotropes exhibiting stronger nasal field crowding before surgical alignment. After surgery, the critical spacing was reduced and rebalanced between the nasal and temporal hemifields. Furthermore, the postoperative recovery of stereopsis was associated with the extent of nasotemporal balance of critical spacing. Conclusions: We find that optical realignment (i.e., strabismus surgery) can normalize the enlarged visual crowding effects, a reliable psychophysical index of cortical organization, in the peripheral visual field of older children and adults with strabismus and rebalance the nasotemporal asymmetry of crowding, promoting the recovery of postoperative stereopsis. Our results indicated a potential of experience-dependent cortical organization after axial alignment even for individuals who are out of the critical period of visual development, illuminating the capacity and limitations of optics on sensory plasticity and emphasizing the importance of ocular correction for clinical practice.

In vitro multitarget activity of sulfadiazine substituted triazenes as antimicrobial, cytotoxic, and larvicidal agents.

Multidrug resistance (MDR) causes difficulties in the treatment of infections and cancer. Research and development studies have become increasingly important for the strategy of preventing MDR. There is a need for new multitarget drug research and advancement to reduce the development of drug resistance in drug-drug interactions and reduce cost and toxic effects. This study aimed to determine the effects of multi-target triazene compounds on antibacterial, antifungal, antiviral, cytotoxic, and larvicidal activities were investigated in vitro. A series of 12 novel of 1,3-diaryltriazene-substituted sulfadiazine (SDZ) derivatives were synthesized, and the obtained pure products characterized in detail by spectroscopic and analytic methods (FT-IR, 1 H-NMR, 13 C-NMR, and melting points). The antibacterial and antifungal activities of these derivatives (AH1-12) were determined by broth microdilution method. All derivatives have been evaluated in cell-based assays for cytotoxic and antiviral activities against Modified Vaccinia Virus Ankara. The larvicidal efficacy of these chemical compounds was also investigated by using Lucilia sericata (L. sericata) larvae. Twelve 1,3-diaryltriazene-substituted SDZ derivatives (AH1-12) were designed and developed as potent multitargeted compounds. Among them, the AH1 derivative showed the most antibacterial and antifungal activity. Besides, synthesized derivatives AH2, AH3, AH5, and AH7 showed higher antiviral activity than SDZ. All synthesized derivatives showed higher cytotoxic activity than SDZ. Also, they showed larvicidal activity at 72 h of the experiment. As a result, these compounds might be great leads for the development of next-generation multitargeted agents.

Polymorphs of a 1:1 salt of sulfadiazine and piperazine-relative stability, dissolution studies, pharmacokinetics and anti-meningitis efficiency.

Two new salt forms of sulfadiazine (SDZ) and piperazine (PIP) were synthesized and characterized. Out of the two polymorphs (SDZ-PIP Ⅰ and SDZ-PIP II), SDZ-PIP Ⅱ is the more stable form at low temperature, room temperature and high temperature. The solution-mediated phase transformation result shows that SDZ-PIP II can transform into pure SDZ within 15 s in phosphate buffer at 37 °C, which leads to a loss in solubility advantage. The addition of 2 mg/mL PVP K30, a polymeric crystallization inhibitor, maintains the solubility advantage and permits supersaturation for a longer period of time. SDZ-PIP II showed 2.5 times the solubility of SDZ alone. The area under the curve (AUC) of SDZ-PIP II with 2 mg/mL PVP K30 was approximately 165% of that of SDZ alone. Moreover, SDZ-PIP II with PVP K30 was more effective than SDZ alone in treating meningitis. Therefore, the SDZ-PIP II salt improves the solubility, bioavailability, and anti-meningitis activity of SDZ.

Understanding the cometabolic degradation of sulfadiazine by an enriched ammonia oxidizing bacteria culture from both extracellular and intracellular perspectives.

Antibiotics are widely used drugs in the world and pose serious threats to ecosystems and human health. Although it has been reported that ammonia oxidizing bacteria (AOB) can cometabolize antibiotics, little has been reported on how AOB would respond to the exposure of antibiotics on extracellular and enzymatic levels, as well as the impact of antibiotics on the bioactivity of AOB. Therefore, in this study, a typical antibiotic, sulfadiazine (SDZ), was selected, and a series short-term batch tests using enriched AOB sludge were conducted to investigate the intracellular and extracellular responses of AOB along the cometabolic degradation process of SDZ. The results showed the cometabolic degradation of AOB made the main contribution to SDZ removal. When the enriched AOB sludge was exposed to SDZ, ammonium oxidation rate, ammonia monooxygenase activity, adenosine triphosphate concentration and dehydrogenases activity were negatively affected. The amoA gene abundance increased 1.5 folds within 24 h, which may enhance the uptake and utilization of substrates and maintain stable metabolic activity. In the tests with and without ammonium, the concentration of total EPS increased from 264.9 to 231.1 mg/gVSS to 607.7 and 538.2 mg/gVSS, respectively, under the exposure to SDZ, which was mainly contributed by the increase of proteins in tightly bound extracellular polymeric substances (EPS) and polysacharides in tightly bound EPS and soluble microbial products. The proportion of tryptophan-like protein and humic acid-like organics in EPS also increased. Moreover, SDZ stress stimulated the secretion of three quorum sensing signal molecules, C4-HSL (from 140.3 to 164.9 ng/L), 3OC6-HSL (from 17.8 to 42.4 ng/L) and C8-HSL (from 35.8 to 95.9 ng/L) in the enriched AOB sludge. Among them, C8-HSL may be a key signal molecule that promoted the secretion of EPS. The findings of this study could shed more light on the cometabolic degradation of antibiotics by AOB.

Biodegradation of trace sulfonamide antibiotics accelerated by substrates across oxic to anoxic conditions during column infiltration experiments.

Frequent occurrence of trace organic contaminants in aquatic environments, such as sulfonamide antibiotics in rivers receiving reclaimed water, is concerning. Natural attenuation by soil and sediment is increasingly relied upon. In the case of riverbank filtration for water purification, the reliability of antibiotic attenuation has been called into question due to incomplete understanding of their degradation processes. This study investigated influence of substrates and redox evolution along infiltration path on biotransformation of sulfonamides. Eight sand columns (length: 28 cm) with a riverbed sediment layer at 3-8 cm were fed by groundwater-sourced tap water spiked with 1 µg/L of sulfadiazine (SDZ), sulfamethazine (SMZ), and sulfamethoxazole (SMX) each, with or without amendments of dissolved organic carbon (5 mg-C/L of 1:1 yeast and humics) or ammonium (5 mg-N/L). Two flow rates were tested over 120 days (0.5 mL/min and 0.1 mL/min). Iron-reducing conditions persisted in all columns for 27 days during the initial high flow period due to respiration of sediment organics, evolving to less reducing conditions until the subsequent low flow period to resume more reducing conditions. With surplus substrates, the spatial and temporal patterns of redox conditions differentiated among columns. The removal of SDZ and SMZ in effluents was usually low (15 ± 11%) even with carbon addition (14 ± 9%), increasing to 33 ± 23% with ammonium addition. By contrast, SMX removal was higher and more consistent among columns (46 ± 21%), with the maximum of 64 ± 9% under iron-reducing conditions. When sulfonamide removal was compared between columns for the same redox zones during infiltration, their enhancements were always associated with the availability of dissolved or particulate substrates, suggesting co-metabolism. Manipulation of the exposure time to optimal redox conditions with substrate amendments, rather than to simply prolong the overall residence time, is recommended for nature-based solutions to tackle target antibiotics.

Efficient purification of aqueous solutions contaminated with sulfadiazine by coupling electro-Fenton/ultrasound process: optimization, DFT calculation, and innovative study of human health risk assessment.

In the current work, the hybrid process potential of ultrasound (US) and electro-Fenton (EF), named sono-electro-Fenton (SEF), was fully investigated for sulfadiazine (SDZ) degradation. The decontamination in the integration approach was revealed to be greater than in individual procedures, i.e., EF process (roughly 66%) and US process (roughly 15%). The key operating process factors (i.e., applied voltage, H2O2 content, pH, initial concentration of SDZ, and reaction time) affecting SDZ removal were evaluated and optimized using Box-Behnken Design (BBD). In addition, an adaptive neuro-fuzzy inference system (ANFIS) as an efficient predictive model was applied to forecast the decontamination efficiency of SDZ through the SEF process based on the same findings produced from BBD. The results revealed that the predictability of SDZ elimination by the ANFIS and BBD approaches exhibited an excellent agreement (a greater R2 of 0.99%) among the both models. Density functional theory was also employed to forecast the plausible decomposition elucidation by the bond-breaking mechanism of organic substances. Plus, the main side products of SDZ degradation during the SEF process were tracked. Eventually, the non-carcinogenic risk assessment of different samples of natural water containing SDZ that was treated by adopting US, EF, and SEF processes was examined for the first time. The findings indicated that the non-carcinogenic risk (HQ) values of all the purified water sources were computed in the permissible range.

Effect of adsorption on ferrihydrite on the photoreactivity of dissolved black carbon for photodegradation of sulfadiazine.

The selective adsorption of dissolved black carbon (DBC) on inorganic minerals is a widespread geochemical process in the natural environment, which could change the chemical and optical properties of DBC. However, it remains unclear how selective adsorption affects the photoreactivity of DBC for photodegradation of organic pollutants. This paper was the first to investigate the effect of DBC adsorption on ferrihydrite at different Fe/C molar ratios (Fe/C molar ratios of 0, 7.50 and 11.25, and marked as DBC0, DBC7.50 and DBC11.25) on the photoproduction of reactive intermediates generated from DBC and their interaction with sulfadiazine (SD). Results showed that UV absorbance, aromaticity, molecular weight and contents of phenolic antioxidants of DBC were significantly decreased after adsorption on ferrihydrite, and higher decrease was observed at higher Fe/C ratio. Photodegradation kinetics experiments showed that observed photodegradation rate constant of SD (kobs) increased from 3.99 × 10-5 s-1 in DBC0 to 5.69 × 10-5 s-1 in DBC7.50 while decreased to 3.44 × 10-5 s-1 in DBC11.25, in which 3DBC* played an important role and 1O2 played a minor role, while ·OH was not involved in the reaction. Meanwhile, the second-order reaction rate constant between 3DBC* and SD (kSD, 3DBC*) increased from 0.84 × 108 M-1 s-1 for DBC0 to 2.53 × 108 M-1 s-1 for DBC7.50 while decreased to 0.90 × 108 M-1 s-1 for DBC11.25. The above results might be mainly attributed to the fact that the decrease of phenolic antioxidants in DBC weakened the back-reduction of 3DBC* and reactive intermediates of SD as the Fe/C ratio increased, while the decrease of quinones and ketones reduced the photoproduction of 3DBC*. The research revealed adsorption on ferrihydrite affected the photodegradation of SD by changing the reactivity of 3DBC*, which was helpful to understand the dynamic roles of DBC in the photodegradation of organic pollutants.

In vitro and in vivo susceptibility to sulfadiazine and pyrimethamine of Toxoplasma gondii strains isolated from Brazilian free wild birds.

Little is known about the existence of drug-resistant Toxoplasma gondii strains and their possible impact on clinic outcomes. To expand our knowledge about the existence of natural variations on drug susceptibility of T. gondii strains in Brazil, we evaluated the in vitro and in vivo susceptibility to sulfadiazine (SDZ) and pyrimethamine (PYR) of three atypical strains (Wild2, Wild3, and Wild4) isolated from free-living wild birds. In vitro susceptibility assay showed that the three strains were equally susceptible to SDZ and PYR but variations in the susceptibility were observed to SDZ plus PYR treatment. Variations in the proliferation rates in vitro and spontaneous conversion to bradyzoites were also accessed for all strains. Wild2 showed a lower cystogenesis capacity compared to Wild3 and Wild4. The in vivo analysis showed that while Wild3 was highly susceptible to all SDZ and PYR doses, and their combination, Wild2 and Wild4 showed low susceptibility to the lower doses of SDZ or PYR. Interestingly, Wild2 presented low susceptibility to the higher doses of SDZ, PYR and their combination. Our results suggest that the variability in treatment response by T. gondii isolates could possibly be related not only to drug resistance but also to the strain cystogenesis capacity.

Enhanced removal of sulfonamide antibiotics from water by phosphogypsum modified biochar composite.

Antibiotic pollution has become a global eco-environmental issue. To reduce sulfonamide antibiotics in water and improve resource utilization of solid wastes, phosphogypsum modified biochar composite (PMBC) was prepared via facile one-step from distillers grains, wood chips, and phosphogypsum. The physicochemical properties of PMBC were characterized by scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), Zeta potential, X-ray diffraction (XRD), etc. The influencing factors, adsorption behaviors, and mechanisms of sulfadiazine (SD) and sulfamethazine (SMT) onto PMBC were studied by batch and fixed bed column adsorption experiments. The results showed that the removal rates of SD and SMT increased with the increase of phosphogypsum proportion, while decreased with the increase of solution pH. The maximum adsorption capacities of modified distillers grain and wood chips biochars for SD were 2.98 and 4.18 mg/g, and for SMT were 4.40 and 8.91 mg/g, respectively, which was 9.0-22.3 times that of pristine biochar. Fixed bed column results demonstrated that PMBC had good adsorption capacities for SD and SMT. When the solution flow rate was 2.0 mL/min and the dosage of PMBC was 5.0 g, the removal rates of SD and SMT by modified wood chips biochar were both higher than 50% in 4 hr. The main mechanisms of SD and SMT removal by PMBC are hydrogen bonding, π-π donor-acceptor, electrostatic interaction, and hydrophobic interaction. This study provides an effective method for the removal of antibiotics in water and the resource utilization of phosphogypsum.

Red osier dogwood extract vs. trimethoprim-sulfadiazine (Part 2). Pharmacodynamic effects on ileal and cecal microbiota of broiler chickens challenged orally with Salmonella Enteritidis.

With the subsisting restrictions on the use of antibiotics in poultry production, the use of plant extracts has shown some promising antimicrobial capacity similar to antibiotics; however, such capacity is largely dependent on their total polyphenol concentration and profile. Given the emerging antimicrobial potential of red osier dogwood (ROD) extract, the study aimed to investigate the pharmacodynamic effect of ROD extract on the ileal and cecal microbiota of broiler chickens challenged orally with Salmonella Enteritidis (SE). A 21 d 4 × 2 factorial experiment was conducted based on 2 main factors, including diets and SE challenge. A total of 384 one-day-old mixed-sex Cobb-500 broiler chicks were randomly allotted to 4 dietary treatments; Negative control (NC), NC + 0.075 mg trimethoprim-sulfadiazine (TMP/SDZ)/kg of diet, and NC containing either 0.3 or 0.5% ROD extract. On d 1, half of the birds were orally challenged with 0.5 mL of phosphate-buffered saline (Noninfected group) and the remaining half with 0.5 mL of 3.1 × 105 CFU/mL SE (Infected group). Dietary treatments were randomly assigned to 8 replicate cages at 6 birds/cage. On d 21, 10 birds/treatment were euthanized and eviscerated to collect ileal and cecal digesta for gut microbiota analysis. The ileal and cecal microbiota was dominated by phyla Firmicutes, Proteobacteria, and Actinobacteriota. The SE infection decreased (P < 0.05) the relative abundance of Proteobacteria and Actinobacteriota in the ileum and ceca, respectively, however, it increased (P < 0.05) Proteobacteria in the ceca. Both 0.3 and 0.5% ROD extracts (P < 0.05) depressed the relative abundance of Actinobacteriota in the ileum but marginally improved (P < 0.05) it in the ceca compared to the TMP/SDZ treatment. Dietary TMP/SDZ increased (P < 0.05) genus Bifidobacterium at the ileal and cecal segments compared to other treatments. Dietary 0.3 and 0.5% marginally improved (P < 0.05) Bifidobacterium in the ceca and depressed (P < 0.05) Weissella and was comparably similar to TMP/SDZ in the ileum. Regardless of the dietary treatments and SE infection, alpha diversity differed (P < 0.05) between ileal and cecal microbiota. Beta diversity was distinct (P < 0.05) in both ileal and cecal digesta along the SE infection model. Conclusively, both ROD extract levels yielded a pharmacodynamic effect similar to antibiotics on ileal and cecal microbiota.

An Electrochemical Sensor for Sulfadiazine Determination Based on a Copper Nanoparticles/Molecularly Imprinted Overoxidized Polypyrrole Composite.

To protect consumers from risks related to overexposure to sulfadiazine, total residues of this antibacterial agent in animal-origin foodstuffs not exceed international regulations. To this end, a new electrochemical sensor based on a molecularly imprinted polymer nanocomposite using overoxidized polypyrrole and copper nanoparticles for the detection of sulfadiazine is elaborated. After optimization of the preparation of the electrochemical sensors, their differential pulse voltammetric signal exhibits an excellent stability and reproducibility at 1.05 V, with a large linear range between 10-9 and 10-5 mol L-1 and a low detection limit of 3.1 × 10-10 mol L-1. The produced sulfadiazine sensor was successfully tested in real milk samples. The combination of the properties of the electrical conduction of copper nanoparticles with the properties of the preconcentration of the molecularly imprinted overoxidized polypyrrole allows for the highly sensitive detection of sulfadiazine, even in real milk samples. This strategy is new and leads to the lowest detection limit yet achieved, compared to those of the previously published sulfadiazine electrochemical sensors.

Evaluation of the effect of guanabenz-loaded nanoparticles on chronic toxoplasmosis in mice.

Chronic toxoplasmosis which is positively correlated with many neuropsychiatric problems has no curative treatment till now; due to the resistant tissue cysts especially in the brain. In search of an effective treatment, guanabenz-loaded polyethylene glycol poly lactic-co-glycolic acid (PEG-PLGA) nanoparticles was evaluated against chronic experimental toxoplasmosis. For this purpose, each mouse was infected with 10 cysts of Toxoplasma gondii (ME 49 strain). Treated mice received either guanabenz alone (5 mg/kg/day) in subgroup IIa or guanabenz-loaded nanoparticles by full dose in subgroup IIb or guanabenz-loaded nanoparticles by the half dose (2.5 mg/kg/day) in subgroup IIc. Subgroup Ie was treated by pyrimethamine and sulfadiazine. The treatment started on day 25 post-infection for 19 successive days. Then Parasitological, histopathological, immunohistochemical, immunological and ultrastructural morphological studies were performed. The results showed that: subgroup IIb showed the highest statistically significant reduction in the neuroinflammation and brain tissue cysts (77%) with a significant higher efficacy in comparison with pyrimethamine and sulfadiazine and showed the highest level of IFN-γ, while the lowest level was in subgroup IIa. All group II mice showed similar changes of depression and compression of the wall of the cyst. This is marked in subgroup IIb with release of crescent shaped bradyzoite outside the cyst. PEG-PLGA nanoparticles had no toxic effect on the liver or the kidney of the mice. It could be concluded that guanabenz-loaded PEG-PLGA nanoparticles could be promising and safe for treatment of chronic toxoplasmosis.