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1.
Front Psychiatry ; 15: 1427482, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39279811

RESUMO

The introduction of a new psychopharmaceutical medication instead of the previous one always poses a certain challenge. In the case of antipsychotics (AP), these problems are considerably more complicated and are mainly caused by the question of dose equivalents, but also by the pharmacokinetic properties of the drug. In the case of partial dopamine D2 agonists, an additional issue is the possibility of deterioration when switching from the previous D2 antagonists to these drugs. Cross-titration is therefore generally recommended. Finally, due to the capsule form, it is not possible to increase the dose of cariprazine by less than 1.5 mg during titration. In this paper, we have presented our proposal to replace the most commonly used second-generation APs with the third-generation AP cariprazine. We have taken into account the dose equivalents, the pharmacological forms of the drugs and their pharmacokinetic and pharmacodynamic properties.

2.
Molecules ; 29(17)2024 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-39275039

RESUMO

Understanding the thermal aging kinetics of animal oils is of vital importance in the storage and applications of animal oils. In this work, we use four different techniques, including UV-Vis spectrometry, viscometry, impedance spectroscopy, and acid-base titration, to study the thermal aging kinetics of tallow, chicken oil, lard, and sheep oil in the temperature range from 120 °C to 180 °C. The evolutions of the UV-Vis absorbance, dynamic viscosity, electric impedance, and acid titration are discussed with the defect kinetics. The evolutions of the color centers, defects for dynamic viscosity, and electric dipoles follow second-order, first-order, and zero-order kinetics, respectively. The temperature dependence of rate constants for the evolutions of the UV-Vis absorbance, dynamic viscosity, electric impedance, and acid titration satisfies the Arrhenius equation with the same activation energy for individual animal oils. The activation energies are ~43.1, ~23.8, ~39.1, and ~37.5 kJ/mol for tallow, chicken oil, lard, and sheep oil, respectively. The thermal aging kinetics of the animal oils are attributed to the oxidation of triglycerides.

3.
Am Heart J Plus ; 45: 100438, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39220718

RESUMO

The objective of our study was to evaluate the real-world effects of an aggressive, personalized protocol for guideline-directed medical therapy (GDMT) titration in patients with heart failure (HF) with reduced ejection fraction (HFrEF). We conducted a two-center retrospective cohort study. Patients with HFrEF who presented to a HF clinic from January 2020 to December 2022 were placed on a GDMT protocol. 180 patients were included in the study. Mean GDMT score significantly increased from 4.7 to 5.9 (p < 0.001) between initial and final visits. Mean left ventricular ejection fraction (LVEF) significantly increased from 28 % to 33 % (+5 %, p < 0.001). 27 (15.7 %) of the 172 patients with complete New York Heart Association (NYHA) classification data had improvement by at least 1 class, while 2 (1.2 %) patients had worsening NYHA classification. 140 (77.8 %) patients had no unplanned hospitalizations between visits. 21 (11.7 %) patients had an unplanned hospitalization for acute HF during the study period with a mean time from first clinic visit to hospitalization of 183 days (range: 13-821 days). 2 (1.1 %) patients were hospitalized due to GDMT-associated adverse drug events (i.e. hypotension, hyperkalemia). 7 (3.9 %) patients died during the study period, which was lower than the predicted 1-year death rate for our cohort (12.3 %) using the MAGGIC score. In conclusion, an aggressive, personalized protocol for GDMT titration in patients with HFrEF led to significant improvements in LVEF, NYHA classification, hospitalization, and mortality in a real-world setting. This protocol may help serve as a road map to lessen the gap between clinical knowledge and practice surrounding optimization of GDMT and move HFrEF patients toward a path to recovery.

4.
JACC Heart Fail ; 2024 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-39243244
5.
ACS Appl Bio Mater ; 7(9): 5784-5794, 2024 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-39226406

RESUMO

Hydrated dispersions containing equimolar mixtures of cationic and anionic amphiphiles, referred to as catanionic systems, exhibit synergistic physicochemical properties, and mixing single-chain cationic and anionic lipids can lead to the spontaneous formation of vesicles as well as other phase structures. In the present work, we have characterized two catanionic systems prepared by mixing N-acyltaurines (NATs) and sarcosine alkyl esters (SAEs) bearing 11 and 12 C atoms in the acyl/alkyl chains. Turbidimetric and isothermal titration calorimetric studies revealed that both NATs form equimolar complexes with SAEs having matching acyl/alkyl chains. The three-dimensional structure of the sarcosine lauryl ester (lauryl sarcosinate, LS)-N-lauroyltaurine (NLT) equimolar complex has been determined by single-crystal X-ray diffraction. The LS-NLT equimolar complex is stabilized by electrostatic attraction and multiple hydrogen bonds, including classical, strong N-H···O hydrogen bonds as well as several C-H···O hydrogen bonds between the two amphiphiles. DSC studies showed that both equimolar complexes show single sharp phase transitions. Transmission electron microscopy and dynamic light scattering studies have demonstrated that the LS-NLT catanionic complex assemblies yield stable medium-sized vesicles (diameter 280-350 nm). These liposomes were disrupted at high pH, suggesting that the designed catanionic complexes can be used to develop base-labile drug delivery systems. In vitro studies with these catanionic liposomes showed efficient entrapment (73% loading) and release of the anticancer drug 5-fluorouracil in the physiologically relevant pH range of 6.0-8.0. The release rate was highest at pH 8.0, reaching about 78%, 90%, and 100% drug release at 2, 6, and 12 h, respectively. These observations indicate that LS-NLT catanionic vesicles will be useful for designing drug delivery systems, particularly for targeting organs such as the colon, which are inherently at basic pH.


Assuntos
Materiais Biocompatíveis , Fluoruracila , Tamanho da Partícula , Fluoruracila/química , Estrutura Molecular , Materiais Biocompatíveis/química , Materiais Biocompatíveis/síntese química , Teste de Materiais , Cátions/química , Sarcosina/química , Sarcosina/análogos & derivados , Ésteres/química , Humanos , Lipossomos/química
6.
Sci Total Environ ; 951: 175562, 2024 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-39153621

RESUMO

Arsenic (As) is the most prolific contaminant in food, triggering arseniasis primarily via contaminated rice and drinking contaminated water. However, toxicological data for arsenite (As (III)) and arsenate (As (V)) on antioxidant enzyme catalase (CAT) at molecular level is shortage. The interaction mechanism of As (III) and As (V) with CAT was investigated using enzyme activity detection, multi-spectroscopic techniques, isothermal titration calorimetry and computational simulations. Results indicated As (III) and As (V) induced protein skeleton relaxation, secondary structure transformation, fluorescence sensitization and particle alteration of CAT, particularly As (III). Moreover, As (III)/As (V) bound to CAT through hydrogen bonding and hydrophobic. As (III) and As (V) contacted with core residues His 74, Asn 147 and His A74, Trp A357, respectively, thereby inhibiting CAT activity. Overall, As (III) is more aggressive against the structure and physiological function of CAT than As (V). Our findings enhance the understanding of health risk related to dietary As exposure.


Assuntos
Catalase , Catalase/metabolismo , Arsênio/metabolismo
7.
Intensive Care Med Exp ; 12(1): 67, 2024 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-39103646

RESUMO

BACKGROUND: Individualised bedside adjustment of mechanical ventilation is a standard strategy in acute coma neurocritical care patients. This involves customising positive end-expiratory pressure (PEEP), which could improve ventilation homogeneity and arterial oxygenation. This study aimed to determine whether PEEP titrated by electrical impedance tomography (EIT) results in different lung ventilation homogeneity when compared to standard PEEP of 5 cmH2O in mechanically ventilated patients with healthy lungs. METHODS: In this prospective single-centre study, we evaluated 55 acute adult neurocritical care patients starting controlled ventilation with PEEPs close to 5 cmH2O. Next, the optimal PEEP was identified by EIT-guided decremental PEEP titration, probing PEEP levels between 9 and 2 cmH2O and finding the minimal amount of collapse and overdistension. EIT-derived parameters of ventilation homogeneity were evaluated before and after the PEEP titration and after the adjustment of PEEP to its optimal value. Non-EIT-based parameters, such as peripheral capillary Hb saturation (SpO2) and end-tidal pressure of CO2, were recorded hourly and analysed before PEEP titration and after PEEP adjustment. RESULTS: The mean PEEP value before titration was 4.75 ± 0.94 cmH2O (ranging from 3 to max 8 cmH2O), 4.29 ± 1.24 cmH2O after titration and before PEEP adjustment, and 4.26 ± 1.5 cmH2O after PEEP adjustment. No statistically significant differences in ventilation homogeneity were observed due to the adjustment of PEEP found by PEEP titration. We also found non-significant changes in non-EIT-based parameters following the PEEP titration and subsequent PEEP adjustment, except for the mean arterial pressure, which dropped statistically significantly (with a mean difference of 3.2 mmHg, 95% CI 0.45 to 6.0 cmH2O, p < 0.001). CONCLUSION: Adjusting PEEP to values derived from PEEP titration guided by EIT does not provide any significant changes in ventilation homogeneity as assessed by EIT to ventilated patients with healthy lungs, provided the change in PEEP does not exceed three cmH2O. Thus, a reduction in PEEP determined through PEEP titration that is not greater than 3 cmH2O from an initial value of 5 cmH2O is unlikely to affect ventilation homogeneity significantly, which could benefit mechanically ventilated neurocritical care patients.

8.
Methods Mol Biol ; 2845: 219-235, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39115670

RESUMO

Isothermal titration calorimetry (ITC) is a widely used technique for the characterization of protein-protein and protein-ligand interactions. It provides information on the stoichiometry, affinity, and thermodynamic driving forces of interactions. This chapter exemplifies the use of ITC to investigate interactions between human autophagy modifiers (LC3/GABARAP proteins) and their interaction partners, the LIR motif-containing sequences. The purpose of this report is to present a detailed protocol for the production of LC3/GABARAP-interacting LIR peptides using E. coli expression systems. In addition, we outline the design of ITC experiments using the LC3/GABARAP:peptide interactions as an example. Comprehensive troubleshooting notes are provided to facilitate the adaptation of these protocols to different ligand-receptor systems. The methodology outlined for studying protein-ligand interactions will help to avoid common errors and misinterpretations of experimental results.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal , Proteínas Reguladoras de Apoptose , Calorimetria , Proteínas Associadas aos Microtúbulos , Ligação Proteica , Termodinâmica , Calorimetria/métodos , Humanos , Ligantes , Proteínas Associadas aos Microtúbulos/metabolismo , Proteínas Associadas aos Microtúbulos/química , Proteínas Reguladoras de Apoptose/metabolismo , Proteínas Reguladoras de Apoptose/química , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/química , Escherichia coli/metabolismo , Peptídeos/química , Peptídeos/metabolismo
9.
Molecules ; 29(15)2024 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-39124899

RESUMO

Anthelmintic resistance in gastrointestinal nematodes produces substantial challenges to agriculture, and new strategies for nematode control in livestock animals are called for. Natural compounds, including tannins, with proven anthelmintic activity could be a functional option as structurally diverse complementary compounds to be used alongside commercial anthelmintics. However, the dual use of two anthelmintic components requires an understanding of the pharmacological effects of the combination, while information concerning the interactions between plant-based polyphenols and commercial anthelmintics is scarce. We studied the direct interactions of proanthocyanidins (PAs, syn. condensed tannins) and a commercial anthelmintic thiabendazole, as a model substance of benzimidazoles, by isothermal titration calorimetry (ITC). Our results show evidence of a direct interaction of an exothermic nature with observed enthalpy changes ranging from 0 to -30 kJ/mol. The strength of the interaction between PAs and thiabendazole is mediated by structural characteristics of the PAs with the strongest positive correlation originating from the presence of galloyl groups and the increased degree of polymerization.


Assuntos
Anti-Helmínticos , Calorimetria , Proantocianidinas , Tiabendazol , Proantocianidinas/química , Proantocianidinas/farmacologia , Tiabendazol/química , Tiabendazol/farmacologia , Anti-Helmínticos/química , Anti-Helmínticos/farmacologia , Termodinâmica , Animais
10.
Molecules ; 29(15)2024 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-39125015

RESUMO

The presented studies aimed to evaluate the peripheral coordinating properties of a novel porphyrinoid family representative preceded by its synthesis for potential sensing purposes. Two synthetic pathways were employed to a obtain maleonitrile derivative, further used as a starting material in the cyclotetramerization reaction. In the first one, DAMN was used in sequential double-reductive alkylation with 2-thiophene-carboxyaldehyde and sodium borohydride. In the second, DAMN was used in a one-pot reaction with 2-thiophene-carboxyaldehyde in the presence of a 5-ethyl-2-methylpyridine borane complex in methanol and acetic acid. Following the Linstead approach, the cyclization reaction led to a novel symmetrical magnesium(II) octaaminoporphyrazine with methyl(2-thiophenylmethylene) substituents. The macrocycle's electrochemical properties were assessed by cyclic and differential pulse voltammetries revealing one reduction and two oxidation peak potentials. The additional spectroelectrochemical measurements showed formation of a cationic form of the macrocycle at an applied potential of 0.6 V. The coordinating properties due to the palladium ion of novel porphyrazines were measured with the use of titration combined with UV-vis spectrometry. The titration of Pd2+ revealed the good sensing activity of porphyrazine in the range of 0.1 to 5 palladium molar equivalents. In addition, Pd2+ ions coordination was also assessed by electrochemical studies, indicating the peak potential shift of 0.1 V in the presence of metal cations. DFT calculations showed the good agreement between theoretical and experimental data in the UV-vis and 1H NMR studies.

11.
Diagnostics (Basel) ; 14(15)2024 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-39125456

RESUMO

For antinuclear antibody (ANA) screening, the gold standard method is an indirect immunofluorescence assay (IIFA) using HEp-2 cells, and a serial dilution test is needed to determine the endpoint titer. We aimed to evaluate the accuracy of the estimated endpoint titer (eEPT) by the NOVA View system, by comparing it with the EPT by the serial dilution method (dEPT). The endpoint titers of a total of 1518 ANA positive cases with five major patterns including speckled, homogeneous, centromere, nucleolar, and nuclear dots patterns were determined using both the estimation function and the serial dilution method by the NOVA View system. A significant correlation between the light intensity unit (LIU) values and dEPTs was identified in all five patterns with high ρ values, ranging from 0.666 to 0.832. However, the overall exact match rate between dEPT and eEPT was 22.1% (336/1518), with the ±one-titer match rate being highest in the centromere pattern (62.8%, 81/129), and lowest in the homogeneous pattern (37.6%, 200/532). This suggests that while LIU values correlate well with dEPT, there are discrepancies in numerical agreement. Most cases that did not show an exact match, showed one-to-three-titer overestimations by eEPT. Therefore, adjusting eEPT downward significantly improved the concordance rates with dEPTs. Further investigation for an appropriate cutoff of LIU values for determining eEPT should be performed for clinical application and contribution to the standardization of the ANA titer.

13.
Sci Rep ; 14(1): 19059, 2024 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-39154086

RESUMO

A modified carbon paste sensor based on N,N'-(((ethane-1,2-diylbis(oxy))bis(2,1-phenylene))bis(methanylylidene))bis(pyridine-2-amine; BPA Schiff base as Cr(III) selective carrier was fabricated and studied in this work. The proposed sensor homogenization and mechanism of action was studied by infra-red (IR) and scanning electron microscope (SEM) with energy dispersive X-ray (EDX) tools. The sensor covered 1.0 × 10-7-1.0 × 10-1 mol L-1 linear range and a detection limit of 7.22 × 10-8 mol L-1 for Cr(III) with 20.17 ± 0.13 mV decade-1 Nernstian slope. 5 s was the response time of the prepared sensor and it was reproducible and stable for 3 months. The working pH range was 3.3-6.0 and it also works well to determine Cr(III) ion in presence of water miscible solvents up to 12.5% content of the methanol and 17.5% of ethanol. The electrode's selectivity was studied using separate and mixed solution methods for selectivity coefficients determination and the sensor showed good selectivity relative to a variety of metal ions (selectivity coefficients = 1.01 × 10-5-8.57 × 10-3). In addition, the practical analysis value of the sensor was demonstrated by measurement of Cr(III) quantitatively in mineral water, supplement and also as an indicator electrode in Cr(III) against EDTA potentiometric titration with good reproducibility (RSDs of 0.91-2.15%).


Assuntos
Carbono , Cromo , Cromo/análise , Cromo/química , Carbono/química , Água/química , Suplementos Nutricionais/análise , Bases de Schiff/química , Limite de Detecção , Concentração de Íons de Hidrogênio , Poluentes Químicos da Água/análise , Eletrodos , Reprodutibilidade dos Testes , Íons/análise , Técnicas Eletroquímicas/métodos
14.
Comput Struct Biotechnol J ; 23: 2985-2994, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-39135886

RESUMO

Cyclic peptides present a robust platform for drug design, offering high specificity and stability due to their conformationally constrained structures. In this study, we introduce an updated version of the Cyclic Peptide Matching program (cPEPmatch) tailored for the identification of cyclic peptides capable of mimicking protein-glycosaminoglycan (GAG) binding sites. We focused on engineering cyclic peptides to replicate the GAG-binding affinity of antithrombin III (ATIII), a protein that plays a crucial role in modulating anticoagulation through interaction with the GAG heparin. By integrating computational and experimental methods, we successfully identified a cyclic peptide binder with promising potential for future optimization. MD simulations and MM-GBSA calculations were used to assess binding efficacy, supplemented by umbrella sampling to approximate free energy landscapes. The binding specificity was further validated through NMR and ITC experiments. Our findings demonstrate that the computationally designed cyclic peptides effectively target GAGs, suggesting their potential as novel therapeutic agents. This study advances our understanding of peptide-GAG interactions and lays the groundwork for future development of cyclic peptide-based therapeutics.

15.
JACC Heart Fail ; 2024 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-39152986

RESUMO

BACKGROUND: Rapid uptitration of guideline-directed medical therapy (GDMT) before and after discharge in hospitalized heart failure (HF) patients is feasible, is safe, and improves outcomes; whether this is also true in patients with coexistent atrial fibrillation/flutter (AF/AFL) is not known. OBJECTIVES: This study sought to investigate whether rapid GDMT uptitration before and after discharge for HF is feasible, safe and beneficial in patients with and without AF/AFL. METHODS: In this secondary analysis of the STRONG-HF (Safety, Tolerability, and Efficacy of Rapid Optimization, Helped by NT-proBNP Testing, of Heart Failure Therapies) trial, GDMT uptitration and patient outcomes were analyzed by AF/AFL status and type (permanent, persistent, paroxysmal). RESULTS: Among 1,078 patients enrolled in STRONG-HF, 496 (46%) had a history of AF, including 238 assigned to high-intensity care (HIC) and 258 to usual care (UC), and 581 did not have a history of AF/AFL, including 304 assigned to HIC and 277 to UC. By day 90, the average percent optimal dose of neurohormonal inhibitors achieved in the HIC arm was similar in patients with and without AF/AFL, reaching approximately 80% of the optimal dose (average absolute difference between AF/AFL and non-AF/AFL groups: -0.81%; 95% CI: -3.51 to 1.89). All-cause death or HF readmission by day 180 occurred less frequently in the HIC than the UC arm, both in patients with and without AF (adjusted HR: 0.75 [95% CI: 0.48-1.19] in AF vs adjusted HR: 0.50 [95% CI: 0.31-0.79] in non-AF/AFL patients; P for interaction = 0.2107). Adverse event rates were similar in patients with and without AF/AFL. AF/AFL type did not affect either uptitration or patient outcomes. CONCLUSIONS: Nearly half of acute HF patients have AF/AFL history. Rapid GDMT uptitration before and early after discharge is feasible, is safe, and may improve outcomes regardless of AF presence or type. (Safety, Tolerability, and Efficacy of Rapid Optimization, Helped by NT-proBNP Testing, of Heart Failure Therapies [STRONG-HF]; NCT03412201).

16.
Chempluschem ; : e202400380, 2024 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-39136597

RESUMO

This article focuses on developing selective receptors for chloride. A series of novel receptors based on a rigid naphthalene spacer bearing tetrafluoropyridines (TFPs) in various substitution patterns has been designed and synthsized. The topology of the receptors was confirmed by X-ray cristallography. Their complexation efficiency was essentially studied in the gas phase through mass spectrometry experiments. Density Functional Theory (DFT) calculations and NMR titration were also performed.

17.
Clin Park Relat Disord ; 11: 100264, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39175580

RESUMO

Introduction: In the United States (US), prophylactic treatment with the antiemetic trimethobenzamide has been used before initiating apomorphine therapy. However, US trimethobenzamide stores have been depleted, leaving uncertainty regarding whether antiemetic pretreatment is needed. Methods: This modified Delphi panel aimed to inform circumstances when apomorphine is initiated without antiemetic pretreatment. During Round 1, a panel of 9 US movement disorder specialists rated the appropriateness of prescribing apomorphine therapy with and without antiemetic pretreatment across 192 patient scenarios and were able to review their scores in relation to other scores. During the Round 2, consensus was defined for each scenario as either strong (>75 % agreement) or moderate (66 % agreement). Results: There was strong consensus on 118 of 192 scenario's (97 as appropriate and 21 as inappropriate), moderate consensus on 29 scenarios, some agreement on 32 scenarios, and lack of agreement on 13 scenarios. In the absence of an antiemetic, there was strong consensus that titration schedules should be flexible and based on dose response. However, the group only reached moderate consensus on the speed of titration, highlighting the need for more systematic information on this area. In the presence of an antiemetic, panelists considered usual initial dosing and flexible titration to be appropriate in most scenarios except for when the patient is already experiencing dopaminergic adverse events. Conclusions: Experts generally reached consensus that apomorphine can usually be prescribed without antiemetic pretreatment. Recommendations described here reflect the areas of greatest agreement among a panel of experts based on current available evidence.

18.
J Clin Sleep Med ; 2024 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-39167433

RESUMO

STUDY OBJECTIVES: Hypoglossal nerve stimulation (HGNS) is a common treatment for obstructive sleep apnea (OSA). Objective assessment of HGNS efficacy measures apnea-hypopnea index (AHI) by multi-amplitude titration polysomnography (tPSG) and/or a single amplitude efficacy sleep study (eHST). Both tests have been used to determine efficacy despite significantly different protocols. This project's aim was to determine differences in objective outcomes in HGNS patients who underwent both tPSG and eHST post-operatively. METHODS: Data from 379 consecutive HGNS patients were retrospectively reviewed. Inclusion requirements were a pre-operative sleep study, a post-operative tPSG, and then an eHST, which at our institution is a type 3 home study. AHI mean and differences were calculated. Wilcoxon rank sum tests were used to analyze differences between tPSG and eHST. Sher15 criteria (post-operative AHI≤15 events/hour and ≥50% reduction from baseline) was calculated and compared by χ2 tests. RESULTS: Ultimately 61 patients met inclusion criteria with an average pre-operative AHI=33.2. When comparing the subject's tPSG versus eHST, tPSG AHI was significantly lower (AHI=8.8 versus AHI=17.6; respectively, p<0.001). There was also a difference in the percentage of patients that met Sher15 criteria when using tPSG (80.3%) versus eHST AHI (45.9%). CONCLUSIONS: HGNS patient's postoperative tPSG AHI was significantly lower than their eHST outcome. This work highlights the importance of reporting the type of post-operative study used in evaluating HGNS efficacy and the need for single amplitude, full-night studies to assess HGNS efficacy more accurately.

19.
Animals (Basel) ; 14(16)2024 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-39199867

RESUMO

The inclusion of rumen buffers in ruminant feeds has gained widespread adoption for the prevention of rumen acidosis, thereby avoiding the negative production and health consequences of low rumen pH and resulting in improved feed efficiency. Benchmarking and quality controlling the performance of rumen buffer materials is of significant interest to feed mills and end-user producers. The aim of this study was to evaluate, develop and optimise a laboratory protocol to consistently and robustly evaluate rumen buffering materials in order to predict their in vivo efficacy. Three different methods were evaluated for determining the buffering potential of carbonate buffer materials: (a) 2 and 8 h static pH, (b) 8 h fixed HCl acid load addition and (c) 3 h acidotic diet simulation using acetic acid. Buffer material, threshold pH, test duration and interactions between all three variables were significant (p < 0.001) in evaluating the performance of the buffer materials. The acidotic diet simulation was found to provide a different ranking of materials to the 8 h fixed HCl acid load methodology. The results highlight the importance of method selection and test parameters for accurately evaluating the potential efficacy of rumen buffer materials.

20.
J Colloid Interface Sci ; 677(Pt B): 780-794, 2024 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-39173511

RESUMO

A new CeCO3OH@(hexagonal/cubic phases-CdS) (CeCO3OH@(H/C-CdS)) composite catalyst was facilely synthesized by a simple microinjection titration-stirring method, in which CdS nanoparticles were dispersed on the surface of CeCO3OH nanolines. The optimal conditions for the preparation of composite catalysts with high photocatalytic performance were determined by single-factor experiments and response surface experiments. Under these conditions, the degradation rate of 30 mL 2.000 g/L rhodamine B (Rh B) by CeCO3OH@(H/C-CdS) in a photocatalytic reaction for 1 h at 25 °C was up to 86.81 % and its degradation rate in a photocatalytic reaction for 150 min was up to 99.62 %. The degradation rate could be maintained above 80 % even after six times recycling. Especially, the photocatalytic degradation efficiency of 2.000 g/L Rh B on the composite catalyst under sunlight and at room temperature for 30 min reached 97.66 %. Meanwhile, the large size of CeCO3OH considerably alleviated the agglomeration of CdS, providing more adsorption and active sites for visible light-mediated degradation of Rh B. Importantly, the Z-scheme charge transfer realized by CdS and CeCO3OH enhanced the efficient separation of photogenerated electrons and holes, and successfully inhibited the recombination of photogenerated electrons with holes. At the same time, owing to the low energy band difference between the two phases of CdS, charge was transferred between the hexagonal and cubic phases, leaving more effective photogenerated charge to participate in the degradation of Rh B. The synergism of the heterophase junction and heterojunction and the presence of oxygen and sulfur vacancies considerably enhanced the degradation performance of the catalyst. Thus, this study provides a new strategy for the modification and enhanced visible-light catalysis performance of CdS-based catalysts.

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