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1.
J Environ Sci (China) ; 144: 212-224, 2024 Oct.
Article in English | MEDLINE | ID: mdl-38802232

ABSTRACT

In this work, the perovskite LaZnO3 was synthesized via sol-gel method and applied for photocatalytic treatment of sulfamethizole (SMZ) antibiotics under visible light activation. SMZ was almost completely degraded (99.2% ± 0.3%) within 4 hr by photocatalyst LaZnO3 at the optimal dosage of 1.1 g/L, with a mineralization proportion of 58.7% ± 0.4%. The efficient performance of LaZnO3 can be attributed to its wide-range light absorption and the appropriate energy band edge levels, which facilitate the formation of active agents such as ·O2-, h+, and ·OH. The integration of RP-HPLC/Q-TOF-MS and DFT-based computational techniques revealed three degradation pathways of SMZ, which were initiated by the deamination reaction at the aniline ring, the breakdown of the sulfonamide moieties, and a process known as Smile-type rearrangement and SO2 intrusion. Corresponding toxicity of SMZ and the intermediates were analyzed by quantitative structure activity relationship (QSAR), indicating the effectiveness of LaZnO3-based photocatalysis in preventing secondary pollution of the intermediates to the ecosystem during the degradation process. The visible-light-activated photocatalyst LaZnO3 exhibited efficient performance in the occurrence of inorganic anions and maintained high durability across multiple recycling tests, making it a promising candidate for practical antibiotic treatment.


Subject(s)
Anti-Bacterial Agents , Light , Oxides , Sulfamethizole , Titanium , Water Pollutants, Chemical , Anti-Bacterial Agents/chemistry , Titanium/chemistry , Oxides/chemistry , Sulfamethizole/chemistry , Water Pollutants, Chemical/chemistry , Calcium Compounds/chemistry , Catalysis , Photolysis , Models, Chemical
2.
RSC Adv ; 14(20): 14114-14125, 2024 Apr 25.
Article in English | MEDLINE | ID: mdl-38686288

ABSTRACT

In this work, twenty-four stable dimers of RCHZ with R = H, F, Cl, Br, CH3 or NH2 and Z = O, S, Se or Te were determined. It was found that the stability of most dimers is primarily contributed by the electrostatic force, except for the dominant role of the induction term in those involving a Te atom, which has been rarely observed. Both electron-donating and -withdrawing groups in substituted formaldehyde cause an increase in the strength of nonconventional Csp2-H⋯Z hydrogen bonds, as well as the dimers, in which the electron donating effect plays a more crucial role. The strength of nonconventional hydrogen bonds decreases in the following order: Csp2-H⋯O ≫ Csp2-H⋯S > Csp2-H⋯Se > Csp2-H⋯Te. Remarkably, a highly significant role of the O atom compared to S, Se and Te in increasing the Csp2-H stretching frequency and strength of the nonconventional hydrogen bonds and dimers is found. A Csp2-H stretching frequency red-shift is observed in Csp2-H⋯S/Se/Te, while a blue-shift is obtained in Csp2-H⋯O. When Z changes from O to S to Se and to Te, the Csp2-H blue-shift tends to decrease and eventually turns to a red-shift, in agreement with the increasing order of the proton affinity at Z in the isolated monomer. The magnitude of the Csp2-H stretching frequency red-shift is larger for Csp2-H⋯Te than Csp2-H⋯S/Se, consistent with the rising trend of proton affinity at the Z site and the polarity of the Csp2-H bond in the substituted chalcogenoaldehydes. The Csp2-H blue-shifting of the Csp2-H⋯O hydrogen bonds is observed in all dimers regardless of the electron effect of the substituents. Following complexation, the electron-donating derivatives exhibit a stronger Csp2-H blue-shift compared to the electron-withdrawing ones. Notably, the stronger Csp2-H blue-shift turns out to involve a less polarized Csp2-H bond and a decrease in the occupation at the σ*(Csp2-H) antibonding orbital in the isolated monomer.

3.
Heliyon ; 10(5): e26783, 2024 Mar 15.
Article in English | MEDLINE | ID: mdl-38434284

ABSTRACT

In this study, we investigated the possibility of a photocatalytic system that uses graphene-quantum-dot (GQD)-deposited graphitic carbon nitride (g-C3N4) to treat tetracycline (TC) and other organic compounds generated from an in-situ-recirculatory-aquaculture-system (RAS)-like shrimp farming pond. GQDs were successfully deposited on the exfoliated g-C3N4 base through a hydrothermal treatment. The results showed that the incorporation of GQDs into the g-C3N4 enhanced its porosity without aggregating its mesoporous structure. The GQDs-deposited g-C3N4 photocatalysts revealed sheet-like structures with nanopores on their surface that facilitate photocatalysis. More than 90% of the TC was removed by the photocatalysts under UV-LED irradiation. Low loadings of GQDs over g-C3N4 resulted in a faster and more effective photocatalysis of TC, mainly driven by.O2- radicals. The photocatalysts were also applicable in the degradation of organic compounds with 27% of the total organic compounds (TOC) being removed from the wastewater of a RAS-like shrimp farming pond.

4.
Chem Biol Drug Des ; 103(3): e14494, 2024 03.
Article in English | MEDLINE | ID: mdl-38490810

ABSTRACT

A series of synthesized sulfonyl thiourea derivatives (7a-o) of substituted 2-amino-4,6-diarylpyrimidines (4a-o) exhibited the remarkable inhibitory activity against some the human carbonic anhydrases (hCAs), including hCA I, II, IX, and XII isoforms. The inhibitory efficacy of synthesized sulfonyl thiourea derivatives were experimentally validated by in vitro enzymatic assays. 7a (KI = 46.14 nM), 7j (KI = 48.92 nM), and 7m (KI = 62.59 nM) (for isoform hCA I); 7f (KI = 42.72 nM), 7i (KI = 40.98 nM), and 7j (KI = 33.40 nM) (for isoform hCA II); 7j (KI = 228.5 nM), 7m (KI = 195.4 nM), and 7n (KI = 210.1 nM) (for isoform hCA IX); 7l (KI = 116.9 nM), 7m (KI = 118.8 nM), and 7n (KI = 147.2 nM) (for isoform hCA XII) in comparison with KI values of 452.1, 327.3, 437.2, and 338.9 nM, respectively, of the standard drug AAZ. These compounds also had significantly more potent inhibitory action against cytosolic isoform hCA I and tumor-associated isoforms hCA IX and hCA XII. Furthermore, the potential inhibitory compounds were subjected to in silico screening for molecular docking and molecular dynamics simulations. The results of in vitro and in silico studies revealed that compounds 7a, 7j, and 7m were the most promising derivatives in this series due to their significant effects on studied hCA I, II, IX, and XII isoforms, respectively. The results showed that the sulfonyl thiourea moiety was accommodated deeply in the active site and interacted with the zinc ion in the receptors.


Subject(s)
Carbonic Anhydrase I , Carbonic Anhydrase Inhibitors , Humans , Carbonic Anhydrase I/metabolism , Carbonic Anhydrase Inhibitors/pharmacology , Carbonic Anhydrase Inhibitors/chemistry , Isoenzymes/metabolism , Molecular Docking Simulation , Molecular Structure , Structure-Activity Relationship , Pyrimidines/chemistry , Pyrimidines/pharmacology
5.
Arch Pharm (Weinheim) ; 357(5): e2300557, 2024 May.
Article in English | MEDLINE | ID: mdl-38321839

ABSTRACT

A series of sulfonyl thioureas 6a-q containing a benzo[d]thiazole ring with an ester functional group was synthesized from corresponding substituted 2-aminobenzo[d]thiazoles 3a-q and p-toluenesulfonyl isothiocyanate. They had remarkable inhibitory activity against acetylcholinesterase (AChE), butyrylcholinesterase (BChE), monoamine oxidase (MAO)-A, and MAO-B. Among thioureas, several compounds had notable activity in the order of 6k > 6 h > 6c (AChE), 6j > 6g > 6k (BChE), 6k > 6g > 6f (MAO-A), and 6i > 6k > 6h (MAO-B). Compound 6k was an inhibitor of interest due to its potent or good activity against all studied enzymes, with IC50 values of 0.027 ± 0.008 µM (AChE), 0.043 ± 0.004 µM (BChE), 0.353 ± 0.01 µM (MAO-A), and 0.716 ± 0.02 µM (MAO-B). This inhibitory capacity was comparable to that of the reference drugs for each enzyme. Kinetic studies of two compounds with potential activity, 6k (against AChE) and 6j (against BChE), had shown that both 6k and 6j followed competitive-type enzyme inhibition, with Ki constants of 24.49 and 12.16 nM, respectively. Induced fit docking studies for enzymes 4EY7, 7BO4, 2BXR, and 2BYB showed active interactions between sulfonyl thioureas of benzo[d]thiazoles and the residues in the active pocket with ligands 6k, 6i, and 6j, respectively. The stability of the ligand-protein complexes while each ligand entered the active site of each enzyme (4EY7, 7BO4, 2BXR, or 2BYB) was confirmed by molecular dynamics simulations.


Subject(s)
Acetylcholinesterase , Butyrylcholinesterase , Cholinesterase Inhibitors , Molecular Docking Simulation , Monoamine Oxidase Inhibitors , Monoamine Oxidase , Humans , Cholinesterase Inhibitors/pharmacology , Cholinesterase Inhibitors/chemical synthesis , Cholinesterase Inhibitors/chemistry , Monoamine Oxidase Inhibitors/pharmacology , Monoamine Oxidase Inhibitors/chemical synthesis , Monoamine Oxidase Inhibitors/chemistry , Monoamine Oxidase/metabolism , Acetylcholinesterase/metabolism , Butyrylcholinesterase/metabolism , Structure-Activity Relationship , Molecular Structure , Thiourea/pharmacology , Thiourea/chemistry , Thiourea/chemical synthesis , Dose-Response Relationship, Drug , Benzothiazoles/pharmacology , Benzothiazoles/chemistry , Benzothiazoles/chemical synthesis , Thiazoles/pharmacology , Thiazoles/chemistry , Thiazoles/chemical synthesis
6.
RSC Med Chem ; 14(12): 2751-2767, 2023 Dec 13.
Article in English | MEDLINE | ID: mdl-38107183

ABSTRACT

Some substituted thioureas (6a-i) containing a 1,3,4-thiadiazole ring were synthesized by the reaction of the corresponding substituted 2-amino-1,3,4-thiadiazoles 3a-i with p-toluenesulfonyl isocyanate in a one-pot procedure. The antibacterial and antifungal activities of these sulfonyl thioureas were estimated using a minimum inhibitory concentration protocol. Almost all the thioureas exhibited remarkable antimicrobial activity. Amongst the studied compounds, thioureas 6a, 6c, 6h, and 6i were better inhibitors against the bacterium S. aureus, with MIC values of 0.78-3.125 µg mL-1. These compounds were also tested for their inhibition against S. aureus enzymes, including enzymes of DNA gyrase, DNA topoisomerase IV (Topo IV), and dihydrofolate reductase. Amongst the compounds, 6h was a strong inhibitor, with IC50 values of 1.22, 53.78, and 0.23, respectively. Induced fit docking calculations were performed to observe the binding efficiency and steric interactions of these compounds. The obtained results showed that compound 6h was compatible with the active sites of S. aureus DNA gyrase 2XCS. This ligand interacted with residues ASP1083 (chain D), MET1121 (chain B), ARG1122 (chain D), and also with HOH2035, HOH2089, HOH2110, HOH2162. Molecular dynamics simulation in a water solvent system showed that the active interactions with residues ASP083 and MET1121 (chain B), along with ASP1083, MET1121, and ARG1122 (chain D), played an important role in stabilizing complex 6h/2XCS in the active pocket.

7.
Chem Biodivers ; 20(11): e202301013, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37749933

ABSTRACT

From the moss Erythrodontium julaceum Paris growing in Vietnam, julacelide (1), a new 3-benzylphthalide, along with methyl orsellinate (2), ethyl orsellinate (3), 4-O-methylhaematommic acid (4), and zeorin (5), were isolated and structurally elucidated. Their chemical structures were elucidated through extensive 1D and 2D NMR analysis and high-resolution mass spectroscopy as well as through comparisons to the existing literature. Compound 4-O-methylhaematommic acid was a new natural product. The absolute configuration of julacelide was defined using time-dependent density functional theory (TDDFT) calculations. Julacelide was evaluated for α-glucosidase inhibition.


Subject(s)
alpha-Glucosidases , Molecular Structure , Magnetic Resonance Spectroscopy , Mass Spectrometry , alpha-Glucosidases/metabolism , Density Functional Theory
8.
RSC Med Chem ; 14(6): 1114-1130, 2023 Jun 22.
Article in English | MEDLINE | ID: mdl-37360390

ABSTRACT

Some substituted glucose-conjugated thioureas containing 1,3-thiazole ring, 4a-h, were synthesized by the reaction of the corresponding substituted 2-amino-4-phenyl-1,3-thiazoles 2a-h with 2,3,4,6-tetra-O-acetyl-ß-d-glucopyranosyl isocyanate. The antibacterial and antifungal activities of these thiazole-containing thioureas were estimated using a minimum inhibitory concentration protocol. Among these compounds, 4c, 4g, and 4h were better inhibitors with MIC = 0.78-3.125 µg mL-1. These three compounds were also tested for their ability to inhibit S. aureus enzymes, including DNA gyrase, DNA topoisomerase IV (Topo IV), and dihydrofolate reductase, and compound 4h was found to be a strong inhibitor with IC50 = 1.25 ± 0.12, 67.28 ± 1.21, and 0.13 ± 0.05 µM, respectively. Induced-fit docking and MM-GBSA calculations were performed to observe the binding efficiencies and steric interactions of these compounds. The obtained results showed that compound 4h is compatible with the active site of S. aureus DNA gyrase 2XCS with four H-bond interactions with residues Ala1118, Met1121, and F:DC11 and also three interactions with F:DG10 (two interactions) and F:DC11 (one interaction). Molecular dynamics simulation in a water solvent system showed that ligand 4h had active interactions with enzyme 2XCS through residues Ala1083, Glu1088, Ala1118, Gly1117, and Met1121.

9.
ACS Omega ; 8(17): 15031-15040, 2023 May 02.
Article in English | MEDLINE | ID: mdl-37151498

ABSTRACT

In this study, Wedelolactone's multitarget activity against Alzheimer's disease was examined using density functional theory and molecular docking techniques. At physiological pH, the pK a and molar fractions have been estimated. The most likely relative rate constants of two radical scavenger mechanisms are formal hydrogen transfer in a lipid environment and single-electron transfer in a water solvent. Compared to Trolox (k overall = 8.96 × 104 M-1 s-1), Wedelolactone (k overall = 4.26 × 109 M-1 s-1) is more efficient in scavenging the HOO• radical in an aqueous environment. The chelation capacity of metals was investigated by examining the complexation of the Cu(II) ion at various coordination positions and calculating the complexation kinetic constants. Furthermore, molecular docking simulations showed that the known forms of Wedelolactone at physiological pH effectively inhibited the AChE and BChE enzymes by comparing their activity to that of tacrine (control). Wedelolactone is a promising drug candidate for Alzheimer's disease therapy in light of these findings.

10.
Heliyon ; 9(4): e14884, 2023 Apr.
Article in English | MEDLINE | ID: mdl-37095977

ABSTRACT

This research combined ultrasonic-assisted extraction (UAE) and natural deep eutectic solvent (NADES) to recover phenolic and flavonoid components from mangosteen rind. The antioxidant activities were determined using DPPH, ABTS+, and hydroxyl assays. NADES prepared from lactic and 1,2-propanediol had the highest extraction efficiency based on the total flavonoid content (TFC) and phenolic contents (TPC). Single-factor experiments were employed to assess the influence of UAE conditions (liquid-to-solid ratio, temperature, water content in NADES, and time) on TFC, TPC, and antioxidant activities. NADES-based UAE conditions were optimized using response surface methodology with the Box-Behnken design model on five dependent responses (TPC, TFC, DPPH, ABTS, and OH). The optimal conditions for the lactic-1,2-Propanediol-based UAE process were 76.7 ml liquid/g solid with 30.3% of water content at 57.5 °C for 9.1 min. Scanning electron microscopy (SEM) was applied to examine the surface morphology of mangosteen rind before and after sonication. This study proposes an efficient, green, and practical approach for recovering phenolics and flavonoids from mangosteen rinds.

11.
IEEE Trans Neural Netw Learn Syst ; 34(12): 10698-10710, 2023 Dec.
Article in English | MEDLINE | ID: mdl-35536803

ABSTRACT

Emerging cross-device artificial intelligence (AI) applications require a transition from conventional centralized learning systems toward large-scale distributed AI systems that can collaboratively perform complex learning tasks. In this regard, democratized learning (Dem-AI) lays out a holistic philosophy with underlying principles for building large-scale distributed and democratized machine learning systems. The outlined principles are meant to study a generalization in distributed learning systems that go beyond existing mechanisms such as federated learning (FL). Moreover, such learning systems rely on hierarchical self-organization of well-connected distributed learning agents who have limited and highly personalized data and can evolve and regulate themselves based on the underlying duality of specialized and generalized processes. Inspired by Dem-AI philosophy, a novel distributed learning approach is proposed in this article. The approach consists of a self-organizing hierarchical structuring mechanism based on agglomerative clustering, hierarchical generalization, and corresponding learning mechanism. Subsequently, hierarchical generalized learning problems in recursive forms are formulated and shown to be approximately solved using the solutions of distributed personalized learning problems and hierarchical update mechanisms. To that end, a distributed learning algorithm, namely DemLearn, is proposed. Extensive experiments on benchmark MNIST, Fashion-MNIST, FE-MNIST, and CIFAR-10 datasets show that the proposed algorithm demonstrates better results in the generalization performance of learning models in agents compared to the conventional FL algorithms. The detailed analysis provides useful observations to further handle both the generalization and specialization performance of the learning models in Dem-AI systems.

12.
J Magn Reson Imaging ; 57(3): 740-749, 2023 03.
Article in English | MEDLINE | ID: mdl-35648374

ABSTRACT

BACKGROUND: Timely diagnosis of meniscus injuries is key for preventing knee joint dysfunction and improving patient outcomes because it decreases morbidity and facilitates treatment planning. PURPOSE: To train and evaluate a deep learning model for automated detection of meniscus tears on knee magnetic resonance imaging (MRI). STUDY TYPE: Bicentric retrospective study. SUBJECTS: In total, 584 knee MRI studies, divided among training (n = 234), testing (n = 200), and external validation (n = 150) data sets, were used in this study. The public data set MRNet was used as a second external validation data set to evaluate the performance of the model. SEQUENCE: A 3 T, coronal, and sagittal images from T1-weighted proton density (PD) fast spin-echo (FSE) with fat saturation and T2-weighted FSE with fat saturation sequences. ASSESSMENT: The detection system for meniscus tear was based on the improved YOLOv4 model with Darknet-53 as the backbone. The performance of the model was also compared with that of three radiologists of varying levels of experience. The determination of the presence of a meniscus tear from surgery reports was used as the ground truth for the images. STATISTICAL TESTS: Sensitivity, specificity, prevalence, positive predictive value, negative predictive value, accuracy, and receiver operating characteristic curve were used to evaluate the performance of the detection model. Two-way analysis of variance, Wilcoxon signed-rank test, and Tukey's multiple tests were used to evaluate differences in performance between the model and radiologists. RESULTS: The overall accuracies for detecting meniscus tears using our model on the internal testing, internal validation, and external validation data sets were 95.4%, 95.8%, and 78.8%, respectively. One radiologist had significantly lower performance than our model in detecting meniscal tears (accuracy: 0.9025 ± 0.093 vs. 0.9580 ± 0.025). DATA CONCLUSION: The proposed model had high sensitivity, specificity, and accuracy for detecting meniscus tears on knee MRIs. EVIDENCE LEVEL: 3 TECHNICAL EFFICACY: Stage 2.


Subject(s)
Meniscus , Tibial Meniscus Injuries , Humans , Retrospective Studies , Menisci, Tibial , Tibial Meniscus Injuries/diagnostic imaging , Tibial Meniscus Injuries/pathology , Arthroscopy , Knee Joint/pathology , Magnetic Resonance Imaging/methods , Sensitivity and Specificity , Neural Networks, Computer
13.
Diagn Interv Imaging ; 104(3): 133-141, 2023 Mar.
Article in English | MEDLINE | ID: mdl-36328943

ABSTRACT

PURPOSE: The purpose of this study was to develop a semi-supervised segmentation and classification deep learning model for the diagnosis of anterior cruciate ligament (ACL) tears on MRI based on a semi-supervised framework, double-linear layers U-Net (DCLU-Net). MATERIALS AND METHODS: A total of 297 participants who underwent of total of 303 MRI examination of the knee with fat-saturated proton density (PD) fast spin-echo (FSE) sequence in the sagittal plane were included. There were 214 men and 83 women, with a mean age of 37.46 ± 1.40 (standard deviation) years (range: 29-44 years). Of these, 107 participants had intact ACL (36%), 98 had partially torn ACL (33%), and 92 had fully ruptured ACL (31%). The DCLU-Net was combined with radiomic features for enhancing performances in the diagnosis of ACL tear. The different evaluation metrics for both classification (accuracy, sensitivity, accuracy) and segmentation (mean Dice similarity coefficient and root mean square error) were compared individually for each image class across the three phases of the model, with each value being compared to its respective value from the previous phase. Findings at arthroscopic knee surgery were used as the standard of reference. RESULTS: With the addition of radiomic features, the final model yielded accuracies of 90% (95% CI: 83-92), 82% (95% CI: 73-86), and 92% (95% CI: 87-94) for classifying ACL as intact, partially torn and fully ruptured, respectively. The DCLU-Net achieved mean Dice similarity coefficient and root mean square error of 0.78 (95% CI: 0.71-0.80) and 0.05 (95% CI: 0.06-0.07), respectively, when segmenting the three ACL conditions with pseudo data (P < 0.001). CONCLUSION: A dual-modules deep learning model with segmentation and classification capabilities was successfully developed. In addition, the use of semi-supervised techniques significantly reduced the amount of manual segmentation data without compromising performance.


Subject(s)
Anterior Cruciate Ligament Injuries , Deep Learning , Male , Humans , Female , Adult , Anterior Cruciate Ligament Injuries/diagnostic imaging , Anterior Cruciate Ligament Injuries/surgery , Retrospective Studies , Magnetic Resonance Imaging/methods , Knee Joint , Rupture , Sensitivity and Specificity
14.
Heliyon ; 8(12): e11845, 2022 Dec.
Article in English | MEDLINE | ID: mdl-36506388

ABSTRACT

Cellulose was extracted from the banana stem by chemical method and the factors affecting the extraction process such as concentration of NaOH and H2O2, as well as the assisted microwave time were investigated. Design-Expert software with Response Surface Methodology was used in the modeling and optimization of the cellulose extraction process. The results of XRD, FT-IR, SEM were also used to determine the physicochemical properties of cellulose obtained from the banana stem. The results of the modeling and optimization process of cellulose extraction showed the efficiency of the process and the high applicability of cellulose from the banana stem to create valuable industrial products.

15.
RSC Adv ; 12(54): 35309-35319, 2022 Dec 06.
Article in English | MEDLINE | ID: mdl-36540253

ABSTRACT

Stable binary complexes of RCZOH⋯CH3CHZ (R = CH3, H, F; Z = O, S) are due to contributions from the O-H⋯O/S and Csp2 -H⋯O/S hydrogen bonds. The strength of Csp2 /O-H⋯O is 1.5 to 2 times greater than that of the Csp2 /O-H⋯S bond. The substitution of H(Csp2 ) of HCZOH by CH3 causes a decrease in complex stability, while the opposite trend occurs for the F atom. A very large red shift of the O-H stretching frequency in O-H⋯O/S bonds was observed. A surprising Csp2 -H blue shift up to 104.5 cm-1 was observed for the first time. It is found that the presence of O-H⋯O/S hydrogen bonds and a decisive role of intramolecular hyperconjugation interactions in the complex cause a significant blue shift of the Csp2 -H covalent bonds. A striking role of O compared to the S atom in determining the blue shift of Csp2 -H stretching vibration and stability of binary complexes is proposed. The obtained results show that the ratio of deprotonation enthalpy and proton affinity could be considered as an index for the classification of the non-conventional hydrogen bond. SAPT2+ results show that the strength of RCSOH⋯CH3CHS complexes is dominated by electrostatic and induction energies, while a larger contribution to the stability of remaining complexes is detected for the electrostatic component.

16.
RSC Adv ; 12(39): 25753-25763, 2022 Sep 05.
Article in English | MEDLINE | ID: mdl-36199345

ABSTRACT

A green synthesis using extract from Citrus maxima peel was developed to fabricate Au-Ce catalysts for the reduction of p-nitrophenol (PNP). Au nanoparticles with a diameter of 6.6 ± 2.5 nm were deposited onto the surface of CeO2 nanorods with a length of 33.1 ± 15.0 nm and a diameter of 7.1 ± 2.1 nm. The mesoporous and non-porous capillary structures of these materials were observed. The interaction between Au and CeO2 increased the specific surface area, pore diameter, and pore volume compared with pure CeO2 (90 m2 g-1, 23.8 Å, and 0.110 cm3 g-1 versus 72 m2 g-1, 23.0 Å, and 0.089 cm3 g-1). The splitting peaks of the surface oxygen and their shifting at lower temperatures compared with CeO2 nanorods were found thanks to the Au-CeO2 interaction, suggesting that their reduction occurred more easily. The synthesized Au-Ce catalysts exhibited excellent activity in the reduction of PNP to p-aminophenol. The 0.2Au-Ce catalyst was the most efficient one for PNP reduction, enabling the conversion of PNP in 30 minutes with a catalyst concentration of 20 mg L-1 and a PNP/NaBH4 molar ratio of 1/200. Moreover, the 0.2Au-Ce catalyst could be reused for at least five consecutive cycles without considerable loss of its activity.

17.
Beilstein J Org Chem ; 18: 1140-1153, 2022.
Article in English | MEDLINE | ID: mdl-36105726

ABSTRACT

Substituted 4-acetyl-3-hydroxy-3-pyrroline-2-ones have been prepared via three-component reactions and the tautomerism of these 3-pyrroline-2-ones is due to the slight difference of energy, and the significantly large rate constant of transformation between two tautomers. 1,4,5-Trisubstituted pyrrolidine-2,3-dione derivatives were prepared from the above mentioned 2-pyrrolidinone derivatives and aliphatic amines, which exist in enamine form and are stabilized by an intramolecular hydrogen bond. A possible reaction mechanism between 3-pyrroline-2-one and aliphatic amine (CH3NH2) was proposed based on computational results and the main product is formed favorably following the PES via the lowest ΔG # pathway in both the gas-phase and an ethanol solvent model. DFT calculations showed that kinetic selectivity is more significant than thermodynamic selectivity for forming main products.

18.
ACS Omega ; 7(23): 20092-20103, 2022 Jun 14.
Article in English | MEDLINE | ID: mdl-35721961

ABSTRACT

Ni-based catalysts dispersed on different supports (MgO-α-Al2O3, CeO2, SBA-15, and MgO-SBA-15) were prepared by the impregnation method. Characteristics of the catalysts, including specific surface areas (N2 physisorption), crystalline phase compositions (powder X-ray diffraction, Raman spectroscopy), reducibility (hydrogen temperature-programmed reduction, H2-TPR), and morphology (scanning electron microscopy (SEM) and transmission electron microscopy, TEM)) were investigated. The activity and stability of the catalysts were tested for the combined steam and CO2 reforming of methane at 700 °C in a microflow system. The results show that the catalysts exhibit high activity in the BRM reaction. At 700 °C, the conversion of CH4 and CO2 reached 86-99% and 67-80%, respectively, in which the Ni/Mg-SBA catalyst is the best with conversions of CH4 and CO2 reaching 99% and 80%. Coke accumulation on the surface of the catalysts for 100 h time on stream (TOS) was evaluated by the temperature-programmed oxidation (TPO) technique. The major cause of the catalytic deactivation was elucidated by combining the determination of the amount and type of deposited coke with the changes in the physicochemical properties of the catalysts after the long-term reaction. Almost complete loss of activity was observed on Ni/Mg-Al catalyst after 100 h TOS, while the activity drop was slow on the Ni/Mg-SBA sample, about 15-20% of the total value. Otherwise, the Ni/CeO2 and Ni/SBA catalysts firmly retained their stable activity for 100 h TOS due to the minimal carbon deposition and stability of these catalysts' structure. The highly considerable formation of inert Cγ carbon and sintering over Ni catalyst supported on MgO-α-Al2O3 were responsible for the lower stability of this catalyst compared to those supported on CeO2 and SBA-15.

19.
Int J Med Sci ; 19(4): 651-658, 2022.
Article in English | MEDLINE | ID: mdl-35582413

ABSTRACT

Objective: The study aims to evaluate long-term ovarian reserve change by serum anti-Mullerian hormone (AMH) level and determine the factors that affect the changes after laparoscopic endometrioma cystectomy. Methods: In a prospective longitudinal study, 104 patients with unilateral (n=77) and bilateral (n=27) endometrioma underwent laparoscopic endometrioma cystectomy. AMH levels were measured preoperatively and at 1, 3, 6, and 12 months postoperatively. Multivariate linear regression analysis was performed to determine factors related to AMH level changes. Results: Median preoperative AMH levels significantly declined from 3.77 ng/mL to 1.60 ng/mL (P<0.001), 1.66 ng/mL (P<0.001), 1.67 ng/mL (P<0.001), and 1.72 ng/mL (P<0.001) at 1, 3, 6, and 12 months postoperatively, respectively. The rate of decrease in AMH was unchanged six months after surgery, 52.2%, 53.7%, 54.8% at 1, 3, 6 months, respectively, and declined to 43.2% at 12 months. Although most factors were associated with AMH level changes in monovariant linear regression, multivariant linear regression analysis showed only three factors that reached the statistical significance, including bilateral endometriomas, mean size of the endometrioma, and preoperative AMH levels. Conclusions: Serum AMH levels decline significantly after laparoscopic cystectomy of endometriomas but recovered at 12 months compared with the first 6 months with unilateral endometrioma. Bilateral endometriomas, size of the cyst, and preoperative AMH levels might independently affect AMH levels at 12 months after surgery.


Subject(s)
Endometriosis , Laparoscopy , Anti-Mullerian Hormone , Cystectomy , Endometriosis/surgery , Female , Follow-Up Studies , Humans , Longitudinal Studies , Prospective Studies , Transforming Growth Factor beta
20.
J Phys Chem A ; 126(20): 3101-3109, 2022 May 26.
Article in English | MEDLINE | ID: mdl-35548930

ABSTRACT

The small binary boron silicon clusters B2Si3q with q going from -2 to +2 and B3Si2p with p varying from -3 to +1 were reinvestigated using quantum chemical methods. The thermodynamic stability of these smallest ribbon structures is governed by both Hückel and ribbon models for aromaticity. The more negative the cluster charge, the more ribbon character is shown. In contrast, the more positive the charge state, the more pronounced the Hückel character becomes. The ribbon aromaticity character can also be classified into ribbon aromatic, semiaromatic, antiaromatic, and triplet aromatic when the electron configuration of a ribbon structure is described as [...π2(n+1)σ2n], [...π2n+1σ2n], [...π2nσ2n], and [...π2n+1σ2n-1], respectively. Geometry optimizations of the B2Si3 lowest-energy structure by some density functional theory (DFT) functionals result in a nonplanar shape because it possesses an antiaromatic ribbon character. However, its π aromaticity assigned by the Hückel rule is stronger in such a way that several other DFT and coupled-cluster theory CCSD(T) calculations show that B2Si3 is indeed stable in a planar form (Cs). A new global equilibrium structure for the anion B2Si32-, which is a ribbon semiaromatic species, was identified. Some benchmark tests were also carried out to evaluate the performance of popular methods for the treatment of binary B-Si clusters. At odds with some previous studies, we found that with reference to the high accuracy CCSD(T)/CBS method, the hybrid TPSSh functional is reliable for a structure search, whereas the hybrid B3LYP functional is more suitable for simulations of some experimental spectroscopic results.

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