Abstract
Waste date palm fiber (DPF) has recently emerged as a promising natural fiber due to its abundance, renewability, and low cost. The study discussed the use of DPF as reinforcement in ...composites, particularly in polybenzoxazine (PBz), epoxy resin (EP), and their copolymer (EP‐co‐PBz) composites. The waste DPF underwent an alkaline treatment process, resulting in a high‐performance material that exhibits exceptional interaction with the matrix. The composite samples were fabricated using 5–20 wt% of alkali treated DPFs with polybenzoxazines and epoxy resins. The study examined the thermal and morphological properties of the resulting composites and found that they exhibited remarkable enhancements in various properties. For instance, the PNaphz‐COOH reinforced 5 wt% DPFs composite showed a significant increase in
T
d5%
and
T
d10%
, while the EP‐co‐PBz reinforced DPFs composites exhibited a remarkable increase in char yield (
Y
c
). The SEM analysis of the composite surface further validated these findings, highlighting the remarkable interfacial bonding between the DPFs and the matrix. The remarkable enhancements in thermal properties demonstrated in this study open up new possibilities for utilizing waste DPF in various applications.
Highlights
Waste date palm fiber enhances thermosetting polymer reinforcement for high‐performance composites.
Alkaline treatment improves interfacial bonding between waste DPF and matrix.
Composites reinforced with waste DPF exhibit outstanding thermal and morphological properties.
Association rule mining (ARM) is a data mining technique to discover interesting associations between datasets. The frequent pattern-growth (FP-growth) is an effective ARM algorithm for compressing ...information in the tree structure. However, it tends to suffer from the performance gap when processing large databases because of its mining procedure. This study presents a modified FP-growth (MFP-growth) algorithm to enhance the efficiency of the FP-growth by obviating the need for recurrent creation of conditional subtrees. The proposed algorithm uses a header table configuration to reduce the complexity of the whole frequent pattern tree. Four experimental series are conducted using different benchmark datasets to analyze the operating efficiency of the proposed MFP-growth algorithm compared with state-of-the-art machine learning algorithms in terms of runtime, memory consumption, and the effectiveness of generated rules. The experimental results confirm the superiority of the MFP-growth algorithm, which focuses on its potential implementations in various contexts.
Background: Glaucoma is the most typical cause of permanent blindness. POAG, or primary open angle glaucoma, is the most common type. The pattern electroretinogram (PERG) has become a promising ...technique for detecting glaucoma early- on. The goal of this study was to assess the ability of PERG to diagnose POAG, especially in early, difficult-to-diagnose cases in comparison with other already established diagnostic methods. Methods: 150 participants (300 eyes) were enrolled in a cross-sectional study at ophthalmology department at Menoufia University Hospital in August 2022 to February 2023. All recruited participants underwent comprehensive ophthalmological and PERG exams. The studied eyes were divided into three groups as 100 normal eyes (Group I), 100 eyes with preperimetric glaucoma (Group II), and 100 eyes with established perimetric glaucoma (Group III). Results: OCT-RNFL average thickness had a significant positive correlation with P50 latency (r=0.289, p=0.041) or P50 amplitude (r=0.302, p=0.018) and N95 amplitude (r=0.640, p=0.001) among group (II). Also, RNFL thickness had negative correlation with P50 amplitude (r= -0.268, p=0.043) among group (III). RNFL thickness and P50 and N95 amplitude showed highest AUC values in detecting preperimetric glaucomatous eyes vs normal eyes (AUC=0.927, 0.952, 904), and for detecting established perimetric glaucomatous eyes vs normal eyes (AUC=1.00, 0.957, 0.983 respectively) compared with VF MD which showed AUC (0.458 and 0.901 respectively). Conclusion: Glaucoma patients exhibit PERG alterations (comparable to RNFL thickness changes) so, it could be used as an accurate diagnostic method in POAG. Because PERG alterations occur before visual field abnormalities, it could be relied on as an early diagnostic tool in preperimetric glaucoma. We can use both RNFL thickness assessment by OCT with PERG parameters as complementary tests for accurate diagnosis of preperimetric glaucoma which represents the most difficult diagnostic challenge in glaucoma diagnosis. Keywords: pattern electroretinogram, preperimetric glaucoma, primary open angle glaucoma, RNFL thickness
Repetitive Mizoroki‐Heck (MH) coupling polymerization was used to create novel chiral polyureas with cinchona alkaloids in the main chain. Apart from two‐component polycondensation of cinchona urea ...dimers with diiodobenzene via MH reaction conditions, some chiral polyureas were easily polymerized under self polycondensation to yield the chiral polymers. The asymmetric Michael addition reaction was successfully carried out using chiral polymers derived cinchona urea. Interestingly, phenolic‐based chiral polymers served as heterogeneous catalysts for the enantioselective Michael reaction, with high catalytic activity and excellent enantioselectivities (up to 99 % ee). These polymeric catalysts were also stable, and they could be recycled and reused.
This manuscript introduced novel chiral polyureas with cinchona alkaloids in the main chain via Mizoroki‐Heck polycondensation reactions. Interestingly, pheloic based chiral polymers served as heterogeneous catalysts. These chiral polymers derived cinchona ureas successfully applied in the asymmetric Michael addition reaction with high level of catalytic activity and excellent enantioselectivities (up to 99 % ee). Finally, these polymeric catalysts were also stable, and they could be recycled and reused with maintained reactivity and stereoselectivity.
Background
Chronic hepatitis C virus (HCV) infection negatively impacts health-related quality of life (HRQL). We aimed to assess patient-reported outcomes (PROs) to evaluate the impact of treating ...chronic HCV with directly acting antivirals (DAAs) on HRQL.
Methods
PROs were assessed prospectively using the PROQOL-HCV questionnaire before (week 0), at the end (week 12), and after DAA treatment at week 24. HRQL was measured in six different dimensions: physical health, emotional health, future uncertainty, intimate relationships, social health, and cognitive functions.
Results
A total of 500 HCV patients receiving DAAs were enrolled; of them, 399 were included in the analysis (median age 57 years, 59% females). HRQL increased significantly between baseline, end of treatment, and week 24 for all dimensions (
P
< 0.001), more often for physical health in females compared to males (OR = 1.69, 95% CI = 1.1–2.5), for future uncertainty among people with diabetes (1.75, 95% CI = 1.05–2.9), and for cognitive functions among obese patients (OR = 1.98; 95% CI = 1.1–3.3). Improvement in HRQL was less common for intimate relations among females (OR = 0.47; 95% CI = 0.3–0.7) and in patients with cirrhosis (OR = 0.35, 95% CI = 0.1–0.7). Improvement in HRQL was consistently higher in < 60 years compared to ≥ 60 years patients, with a significant difference in social health (
P
< 0.001) and future uncertainty (
P
< 0.049) HRQL domains.
Conclusion
HRQL improved with DAA therapy, a relation consistent across all HRQL dimensions up to 12 weeks after the end of treatment.
Chiral polyureas of cinchona alkaloids were synthesized via repetitive Mizoroki‐Heck (MH) coupling reaction. The Pd‐catalyzed polycondensation of cinchona urea dimers 6 and aromatic diiodide 7 ...afforded the chiral polyureas (P1−P4). The catalytic activity of the chiral polymers was subsequently investigated. The asymmetric Michael addition of ketoesters to nitroolefins was successfully catalyzed by the polymeric organocatalysts (P1−P4) to give the corresponding Michael adducts with high catalytic activities and excellent enantionselectivities (up to >99% ee). The polymeric catalysts were insoluble in commonly used organic solvents. They were easily recovered and reused several times without any loss of the catalytic activity.
Cinchona alkaloid polyurea catalyst: Mizoroki‐Heck polymerization of cinchona urea dimer and 1,4‐diiodobenzene gave a new type of chiral polyurea, which showed excellent catalytic activity in asymmetric Michael reactions. Up to >99% ee of the product was obtained with the polyurea catalyst which can be reused several times without any loss of the activity.
A novel chitosan-supported cinchona urea heterogeneous catalyst was developed for asymmetric reaction. The catalytic activity of the chitosan-supported organocatalyst was examined in the asymmetric ...Michael addition reaction to give chiral adducts in good yields with excellent enantioselectivities (up to 99% ee). The insolubility of the chitosan-supported cinchona urea catalyst facilitated catalyst recovery. The catalyst was easily separated and reused without any loss in catalytic activity.
Display omitted
•Design and synthesis of chitosan-supported cinchona urea derivatives.•Urea moiety of the chitosan-supported cinchona urea catalyst played an important role for the asymmetric Michael addition.•Good reusability of chitosan-supported catalyst without significant loss in catalytic performance.
A convenient synthesis of intermediate 4,5-diamino-3-aryl-l-phenylpyrazoles 4a--4c was reported. The different cyclization reactions were carried out with chalcone, 2-mercaptoacetic acid and ...p-anisialdehyde, ethyl chloroformate, glyoxal and thiourea to afford different N and S containing heterocycles. The reaction conditions were compared by conventional heating and microwave irradiation. The structures of the cyclization products were de- termined by analytical and spectroscopic data. All the synthesized compounds were screened for antibacterial activities in vitro.
Different analogues of Capravirine (AG-1549) or S-1153 were prepared by synthesis of 2-(5-benzyl-4-isopropyl-1-methyl-2,3-dihydro-1H-imidazol-2-ylthio)acetamide (3a-c), ethyl ...5-benzyl-1-(ethoxymethyl)-4-ethyl-1H-imidazol-2-ylthioacetate (10), 2-5-alkyl-4-substituted 1-(pyridin-4-ylmethyl)-1H-imidazol-2-ylthioacetamides (12a-f), and 2-5-benzyl-1-(benzyloxymethyl)-4-isopropyl-1H-imidazol-2-ylthioacetamides (14a-l) from their corresponding amino acids through a sequence of reactions: Dakin-West reaction, hydrolysis, condensation with thiocyanate derivatives, alkylation with 2-iodoacetamide and ethyl chloroacetate, and coupling with 4-pyridylmethyl chloride, ethoxymethyl chloride and benzyloxymethyl chloride. All the synthesized compounds were screened for their activity against HIV-1 (wild type) and some of them (especially Capravirine like structures) were found active.
Coupling of 5-amino-1,3-diaryl-pyrazoles 1a-c with diazonium salts of different aryl amines gave a series of novel 1,3-diaryl-5-amino-4-arylazopyrazoles 3a-l. Such compounds could be also obtained by ...reaction of 5-amino-1,3-diaryl-4-nitroso-1H-pyrazoles 2a-c with different aryl amines in alkaline medium. Oxidation of azo derivatives 3a-l with cupric acetate, in dimethyl formamide and stream of air, gave 2,4,6-triaryl-2,4-dihydropyrazolo 4,3-d-1,2,3-triazoles 4a-l. and the fluorescence properties of the cyclic triazoles were studied. Diazotization of 5-amino-1,3-diaryl-1H-pyrazoles 1a-c by sodium nitrite in ortho-phosphoric acid followed by coupling with some aryl amines gave o-aminoazo compounds 5a-f. Cyclisation of compounds 5a-f in pyridine and cupric acetate gave the corresponding triazoles 6a-f. The coupling of compounds 6a-f with different aryl diazonium salts gave compounds 7a-j. The synthesized dyes were applied to polyesters as disperse dyes and the fastness properties were evaluated. 5-Amino-1,3-diaryl-pyrazoles 1a-c 와 다양한 aryl amine의diazonium salts를 반응시켜서 1,3-diaryl-5-amino-4-arylazopyrazoles 3a-l을 합성하였으며, 몇 가지 화합물은 5-amino-1,3-diaryl-4-nitroso-1H-pyrazoles 2a-c와 aryl amine의 diazonium salts를 반응시켜서 얻었다. 합성한 azo 유도체 화합물 3a-l을 DMF 용매 속에서 cupric acetate와 산화반응시켜서 2,4,6-triaryl-2,4-dihydropyrazolo 4,3-d-1,2,3-triazoles 4a-l을 합성하였으며, 합성한 cyclic triazoles에 대한 형광 특성을 측정하였다. 한편,Diazotization of sodium nitrite/ortho-phosphoric acid 조건에서 5-amino-1,3-diaryl-1H-pyrazoles 1a-c를 diazotization화 반응시킨 다음에, aryl amines과 반응시켜서 o-aminoazo compounds 5a-f를 합성하였다. 합성한 화합물 5a-f를 pyridine/cupric acetate 반응 조건에서 반응시켜서 triazole 6a-f들을 합성하였으며, 얻어진 화합물 6a-f을 aryl diazonium salts과 반응시켜서 화합물 7a-j을 합성하였다. 합성한 염료 화합물을 polyesters에 분산염료와 정착성을 측정하였다. KCI Citation Count: 0
PDF
