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1.
J Youth Adolesc ; 2024 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-38782846

RESUMO

Accuracy and assumed similarity are the most central topics in the research area of interpersonal perception. These two interpersonal perceptual tendencies have been demonstrated to have beneficial effects on adults' psychological functioning independently. However, how and why they influence adolescent psychological adjustment is less well-understood. The present research aimed to examine the mediating role of peer relationships in the association between these two interpersonal perceptual tendencies and psychological adjustment in adolescents. In the first study, a sample of adolescents in their first year of college (N = 93, 63% girls, Mage = 17.45 years, SD = 0.52) were recruited from a university located in Eastern China. They completed the likableness ratings of Anderson's 200 adjectives. The top 10 personality traits with the lowest and highest likableness values were selected to measure adolescents' personality profiles. In the second study, a round-robin design in a real-life setting, a sample of Chinese adolescents in grades six to nine were recruited from two middle schools (N = 337, Ndyads = 918, 47% girls, Mage = 13.76, SD = 1.15). They were requested to rate themselves and their peers within the same group on various factors. Results revealed that adolescents could form an accurate perception of their peers' personalities and concurrently assume that their peers' personalities are similar to their own. More importantly, accurate interpersonal perception and a biased tendency towards assumed similarity could, directly and indirectly, benefit adolescent psychological adjustment through peer relationships.

2.
Br J Anaesth ; 131(4): 653-663, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37718096

RESUMO

BACKGROUND: Anaemic cardiac surgery patients are at greater risk of intraoperative red blood cell transfusion. This study questions the application of the World Health Organization population-based anaemia thresholds (haemoglobin <120 g L-1 in non-pregnant females and <130 g L-1 in males) as appropriate preoperative optimisation targets for cardiac surgery. METHODS: A retrospective cohort study was conducted on adults ≥18 yr old undergoing cardiopulmonary bypass surgery. Logistic regression was applied to define sex-specific preoperative haemoglobin concentrations with reduced probability of intraoperative red blood cell transfusion for cardiac surgery patients. RESULTS: Data on 4384 male and 1676 female patients were analysed. Binarily stratified multivariable logistic regression odds of receiving intraoperative red blood cell transfusion increased in cardiac surgery patients >45 yr old (odds ratio [OR] 1.84; 95% confidence interval [CI] 1.33-2.55), surgery urgency <30 days (OR 2.03; 95% CI 1.66-2.48), combined coronary artery bypass grafting and valve surgery, or other surgery types (OR 2.24; 95% CI 1.87-2.67), and female sex (OR 1.92; 95% CI 1.62-2.28). The odds decreased by 8.4% with each 1 g L-1 increase in preoperative haemoglobin (OR 0.92; 95% CI 0.91-0.92). Logistic regression predicted females required a preoperative haemoglobin concentration of 133 g L-1 and males 127 g L-1 to have a 15% probability of intraoperative transfusion. CONCLUSIONS: The World Health Organization female anaemia threshold of haemoglobin <120 g L-1 disproportionately disadvantages female cardiac surgery patients. A preoperative haemoglobin concentration ≥130 g L-1 in adult cardiac surgery patients would minimise their overall probability of intraoperative red blood cell transfusion to <15%.


Assuntos
Procedimentos Cirúrgicos Cardíacos , Transfusão de Eritrócitos , Adulto , Humanos , Feminino , Masculino , Estudos Retrospectivos , Ponte de Artéria Coronária , Probabilidade
3.
Molecules ; 28(16)2023 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-37630417

RESUMO

The dichloromethane extract of the roots of Bridelia balansae Tutcher (Phyllanthaceae) was found to show potential anticancer activity against HCT116 colorectal cancer cell. Our bioassay-guided phytochemical investigation of the roots of B. balansae led to the identification of 14 compounds including seven lignans (1-7), three phenylbenzene derivatives (8-10), two flavanone (11-12), and two triterpenoids (13-14). Among them, 4'-demethyl-4-deoxypodophyllotoxin (1) is the first aryltetralin lignan compound identified from this plant species. In addition, the stereochemistry of 1 was validated by X-ray crystallography for the first time, and its distinguished cytotoxic effect on HCT116 cells with an IC50 value at 20 nM was induced via an apoptosis induction mechanism. Compound 1 could also significantly decrease the migration rate of HCT116 cells, indicating its potential application against cancer metastasis. The western blot analysis showed that 1 has the potential to inhibit cell proliferation and metastasis. Treatment of 1 resulted in the downregulation of matrix metalloproteinases 2 (MMP2) and p-Akt, while p21 was upregulated. Collectively, the present study on the phytochemical and biological profile of B. balansae has determined the plant as a useful source to produce promising anticancer lead compounds.


Assuntos
Lignanas , Malpighiales , Bioensaio , Western Blotting , Morte Celular , Proliferação de Células , Lignanas/farmacologia
4.
Molecules ; 27(5)2022 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-35268699

RESUMO

Previous studies have reported that recombinant tumor necrosis factor (TNF)-α has powerful antiviral activity but severe systematic side effects. Jasminin is a common bioactive component found in Chinese herbal medicine beverage "Jasmine Tea". Here, we report that jasminin-induced endogenous TNF-α showed antiviral activity in vitro. The underlying TNF-α-inducing action of jasminin was also investigated in RAW264.7 cells. The level of endogenous TNF-α stimulated by jasminin was first analyzed by an enzyme-linked immunosorbent assay (ELISA) from the cell culture supernatant of RAW264.7 cells. The supernatants were then collected to investigate the potential antiviral effect against herpes simplex virus 1 (HSV-1). The antiviral effects of jasminin alone or its supernatants were evaluated by a plaque reduction assay. The potential activation of the PI3K-Akt pathway, three main mitogen-activated protein kinases (MAPKs), and nuclear factor (NF)-κB signaling pathways that induce TNF-α production were also investigated. Jasminin induces TNF-α protein expression in RAW264.7 cells without additional stimuli 10-fold more than the control. No significant up-expression of type I, II, and III interferons; interleukins 2 and 10; nor TNF-ß were observed by the jasminin stimuli. The supernatants, containing jasminin-induced-TNF-α, showed antiviral activity against HSV-1. The jasminin-stimulated cells caused the simultaneous activation of the Akt, MAPKs, and NF-κB signal pathways. Furthermore, the pretreatment of the cells with the Akt, MAPKs, and NF-κB inhibitors effectively suppressed jasminin-induced TNF-α production. Our research provides evidence that endogenous TNF-α can be used as a strategy to encounter viral infections. Additionally, the Akt, MAPKs, and NF-κB signaling pathways are involved in the TNF-α synthesis that induced by jasminin.


Assuntos
Fosfatidilinositol 3-Quinases , Fator de Necrose Tumoral alfa , Antivirais/farmacologia , Lipopolissacarídeos/farmacologia , NF-kappa B/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Fator de Necrose Tumoral alfa/metabolismo
5.
Org Biomol Chem ; 18(20): 3848-3852, 2020 05 27.
Artigo em Inglês | MEDLINE | ID: mdl-32400817

RESUMO

The total synthesis of six novel okaramines (C, J, L, and S-U) was accomplished with a precise synthesis scheme involving a few steps and a practical yield of 6.7%-23% was obtained. The significance of this study includes the design of a successful and convenient synthesis method for preparation of 3a-hydroxy-pyrrolo[2,3-b]-indole and C-7 prenylated l-tryptophan derivatives using a nucleophilic attack of cyclopropylazetoindoline and an aza-Claisen rearrangement of N-reverse-prenyl tryptophan, respectively.

6.
J Org Chem ; 84(2): 831-839, 2019 01 18.
Artigo em Inglês | MEDLINE | ID: mdl-30562032

RESUMO

Javanicunines A-B and 9-deoxy-PF1233s A-B belong to a family of natural diketomorpholines with a unique isopropenyl group at C-10b or C-5a and a hydroxyl group at C-11a or C-10b. We herein reported the first total synthesis of javanicunines A-B and 9-deoxy-PF1233s A-B. Pivotal features of the synthesis included a nucleophilic substitution reaction, followed by a Davis' oxaziridine oxidation to assemble javanicunines A-B, and a chemoselective and stereoselective oxidation with Murray's reagent to install the requisite C-10b hydroxyl group in 9-deoxy-PF1233s A-B. The present synthesis also established the absolute configuration of javanicunine B.

7.
Bioorg Chem ; 86: 44-51, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30685643

RESUMO

Human dihydroorotate dehydrogenase (hDHODH) is a flavin-dependent enzyme essential to pyrimidine de novo biosynthesis, which serves as an attractive therapeutic target for the treatment of autoimmune disorders. A novel series of hDHODH inhibitors was developed based on a lead which was obtained by a medicinal chemistry exploration. Most compounds showed moderate to significant potency against hDHODH, compounds 5d, 5e, and 6a effectively inhibited the activities of hDHODH with IC50 values from 0.9 to 2.8 µM. Further studies showed that compound 5e also effectively suppressed proliferation of the activated PBMCs (IC50 = 20.35 µM). Surprisingly, compound 5e also showed anti-pulmonary fibrotic activity similar to that of pirfenidone in vitro assay. Therefore, compound 5e might have potential to be developed as a novel hDHODH inhibitors for autoimmune diseases therapy.


Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Descoberta de Drogas , Inibidores Enzimáticos/farmacologia , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/antagonistas & inibidores , Fibrose Pulmonar/tratamento farmacológico , Células A549 , Anti-Inflamatórios não Esteroides/síntese química , Anti-Inflamatórios não Esteroides/química , Proliferação de Células/efeitos dos fármacos , Di-Hidro-Orotato Desidrogenase , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Humanos , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/metabolismo , Microssomos/efeitos dos fármacos , Microssomos/metabolismo , Estrutura Molecular , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/metabolismo , Fibrose Pulmonar/metabolismo , Fibrose Pulmonar/patologia , Relação Estrutura-Atividade , Células Tumorais Cultivadas
8.
Molecules ; 24(10)2019 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-31108884

RESUMO

A series of benzimidazole carboxamide derivatives have been synthesized and characterized by 1H-NMR, 13C-NMR and HRMS. PARP inhibition assays and cellular proliferation assays have also been carried out. Compounds 5cj and 5cp exhibited potential anticancer activities with IC50 values of about 4 nM against both PARP-1 and PARP-2, similar to the reference drug veliparib. The two compounds also displayed slightly better in vitro cytotoxicities against MDA-MB-436 and CAPAN-1 cell lines than veliparib and olaparib, with values of 17.4 µM and 11.4 µM, 19.8 µM and 15.5 µM, respectively. The structure-activity relationship based on molecular docking was discussed as well.


Assuntos
Imidazóis/síntese química , Imidazóis/farmacologia , Neoplasias/metabolismo , Inibidores de Poli(ADP-Ribose) Polimerases/síntese química , Inibidores de Poli(ADP-Ribose) Polimerases/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Descoberta de Drogas , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Imidazóis/química , Modelos Moleculares , Simulação de Acoplamento Molecular , Neoplasias/tratamento farmacológico , Poli(ADP-Ribose) Polimerase-1/antagonistas & inibidores , Poli(ADP-Ribose) Polimerase-1/química , Inibidores de Poli(ADP-Ribose) Polimerases/química , Poli(ADP-Ribose) Polimerases/química , Poli(ADP-Ribose) Polimerases/metabolismo , Relação Estrutura-Atividade
9.
Zhongguo Zhong Yao Za Zhi ; 44(3): 500-508, 2019 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-30989915

RESUMO

This Paper aimed to analyze and identify the chemical constituents from the seeds of Celosia argentea by UPLC-ESI-Q-TOF-MS. The analysis was performed on an ACQUITY HSS T3 reverse phase column(2.1 mm ×100 mm, 1.8 µm). The mobile phase consisting of 0.1% formic acid acetonitrile and 0.1% aqueous formic acid was used for gradient elution, and the flow rate was 0.4 mL·min~(-1). Mass spectrometry was applied for the qualitative analysis under positive and negative ionization modes and ESI ion source. Data was analyzed by Masslynx 4.1 software, literatures in SciFinder database, and standards. A total of 49 compounds, including 14 triterpenoids, 17 flavonoids, 11 cyclic peptides, 2 phenols, 2 organic acids, and 3 steroids were putatively identified. Among them, 19 compounds were firstly reported from this species. In-depth chemical constituent analysis for the seeds of C. argentea were accomplished here, and the findings could lay a good foundation for its quality control and clarifying the material basis of its efficacy.


Assuntos
Celosia/química , Compostos Fitoquímicos/análise , Sementes/química , Cromatografia Líquida de Alta Pressão , Espectrometria de Massas por Ionização por Electrospray
10.
J Nat Prod ; 81(1): 98-105, 2018 01 26.
Artigo em Inglês | MEDLINE | ID: mdl-29281282

RESUMO

Concise total syntheses of the natural phytoalexins 2-hydroxy-8-(4-hydroxyphenyl)phenalen-1-one (1), 2-hydroxy-8-(3,4-dihydroxyphenyl)phenalen-1-one (2), and hydroxyanigorufone (4), together with regioisomer 3 are accomplished in 11 or 12 steps. The synthetic strategy features a Friedel-Crafts acylation to construct the 1H-phenalen-1-one tricyclic core followed by a Suzuki cross-coupling to obtain the target compounds.


Assuntos
Fenalenos/química , Sesquiterpenos/química , Acilação , Produtos Biológicos/química , Fitoalexinas
11.
Molecules ; 23(12)2018 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-30563201

RESUMO

The purpose of this research was to investigate the chemical profile, nutritional quality, antioxidant and hypolipidemic effects of Mexican chia seed oil (CSO) in vitro. Chemical characterization of CSO indicated the content of α-linolenic acid (63.64% of total fatty acids) to be the highest, followed by linoleic acid (19.84%), and saturated fatty acid (less than 11%). Trilinolenin content (53.44% of total triacylglycerols (TAGs)) was found to be the highest among seven TAGs in CSO. The antioxidant capacity of CSO, evaluated with ABTS•+ and DPPH• methods, showed mild antioxidant capacity when compared with Tocopherol and Catechin. In addition, CSO was found to lower triglyceride (TG) and low-density lipoprotein-cholesterol (LDL-C) levels by 25.8% and 72.9%respectively in a HepG2 lipid accumulation model. As CSO exhibits these chemical and biological characteristics, it is a potential resource of essential fatty acids for human use.


Assuntos
Compostos Fitoquímicos/química , Óleos de Plantas/química , Salvia/química , Antioxidantes/química , Ácidos Graxos/química , Células Hep G2 , Humanos , Compostos Fitoquímicos/metabolismo , Óleos de Plantas/metabolismo , Sementes/química , Triglicerídeos , Ácido alfa-Linolênico/química
12.
Wei Sheng Yan Jiu ; 46(1): 94-98, 2017 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-29903159

RESUMO

OBJECTIVE: To implement molecular subtyping and traceability analysis of Campylobacter jejuni isolated from chicken carcasses in slaughterhouses in some provinces. METHODS: A total of 72 Campylobacter jejuni strains were subtyped by fluorescent amplified fragment length polymorphism with Hind Ⅲ and Hha Ⅰ. After electrophoresis results were analyzed with Gene Marker V1. 80, Cluster analysis was performed by Bio Numerics software to further establish tracing analysis database of Campylobacter jejuni. RESULTS: 241 polymorphic fragments were yielded among 72 islolates, while most isolates gave 80 to 100 fragments. 72 FAFLP types were yielded among 72 strains with a resolution of 100%. According to 70% similarity, 72 strains were assigned to 11 clusters. The lowest similarity between clusters was 56. 9%, and the highest similarity was 94. 9%. According to 80% similarity, cluster A could be divided into 5 sub-clusters, and cluster B was divided into 15 sub-clusters. Strains in the same sub-cluster displayed complete regional homology. CONCLUSION: FAFLP is suitable for molecular subtyping andtraceability analysis of Campylobacter jejuni for its high resolution and good regional homology of cluster analysis.


Assuntos
Análise do Polimorfismo de Comprimento de Fragmentos Amplificados , Infecções por Campylobacter/microbiologia , Campylobacter jejuni/genética , Campylobacter jejuni/isolamento & purificação , Carne/microbiologia , Matadouros , Animais , Infecções por Campylobacter/transmissão , Galinhas , Contaminação de Alimentos/análise , Humanos , Polimorfismo de Fragmento de Restrição
13.
Child Abuse Negl ; 141: 106236, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37192589

RESUMO

BACKGROUND: Due to its diversifying and appealing content, short-form videos have developed very rapidly since its emergence, with more and more users enjoying the transient pleasures from such videos, which have triggered widespread concern over the detrimental influence of short-form video addiction on adolescent health. OBJECTIVE: The present study intended to examine the longitudinal relations among paternal/maternal harsh parenting, adolescents' emotional dysregulation and their short-form video addiction using a cross-lagged longitudinal design. PARTICIPANTS AND SETTING: We recruited a sample of 1064 adolescent students from two middle schools located in rural areas of eastern China. METHODS: Adolescents reported on paternal and maternal harsh parenting, their own emotional dysregulation and short-form video addiction at three time points across two years. Autoregressive and cross-lagged models were analyzed using three-wave variables to test the associations among parental (maternal) harsh parenting, adolescent emotional dysregulation, and short-form video addiction. A multi-group analysis was used to test for potential gender differences in the model. RESULTS: We found that harsh fathering but not harsh mothering contributed to adolescent emotional dysregulation, which in turn predicted adolescent short-form video addiction. However, the reverse longitudinal relationships did not exist. Multiple group analyses revealed that the predictive effect of harsh fathering on adolescent emotional dysregulation was stronger in boys. CONCLUSIONS: Our findings help clarify the complex relationships among harsh parenting, adolescent emotional dysregulation and short-form addiction, providing more effective guidance for prevention against adolescent short-form video addiction.


Assuntos
Pai , Poder Familiar , Masculino , Feminino , Humanos , Adolescente , Poder Familiar/psicologia , Pai/psicologia , Mães/psicologia , Pais , Estudantes/psicologia
14.
IEEE Trans Pattern Anal Mach Intell ; 45(10): 11654-11667, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37310843

RESUMO

The interpretability of policies remains an important challenge in Deep Reinforcement Learning (DRL). This paper explores interpretable DRL via representing policy by Differentiable Inductive Logic Programming (DILP) and provides a theoretical and empirical study of DILP-based policy learning from an optimization perspective. We first identified a fundamental fact that DILP-based policy learning should be solved as a constrained policy optimization problem. We then proposed to use Mirror Descent for policy optimization (MDPO) to deal with the constraints of DILP-based policies. We derived the closed-form regret bound of MDPO with function approximation, which is helpful to the design of DRL frameworks. Moreover, we studied the convexity of DILP-based policy to further verify the benefits gained from MDPO. Empirically, we experimented MDPO, its on-policy variant, and 3 mainstream policy learning methods, and the results verified our theoretical analysis.

15.
Child Abuse Negl ; 129: 105621, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35439628

RESUMO

BACKGROUND: Extant models of the association between harsh parenting and social anxiety among adolescents are mostly partial mediation models, leaving much of the relationship unaccounted for. OBJECTIVE: The current study intends to test a two-mediator model in which adolescents' cognitive reactivity and emotional dysregulation were assumed to mediate the potential impact of harsh parenting on their social anxiety. PARTICIPANTS AND SETTINGS: A sample of 726 adolescent students with their parents was recruited from two middle schools located in a provincial city of Northern China. METHODS: Both fathers and mothers were required to report on their spouse's harsh parenting practices. The "Behind your back" task was used to assess cognitive reactivity of adolescents who also reported on their emotional dysregulation and social anxiety. Moderated mediation model and simple slope analyses were used to examine the meditational relations and the moderating role of child sex. RESULTS: For the current model, cognitive reactivity and emotional dysregulation could completely mediate the potential influence of harsh fathering and harsh mothering on adolescents' social anxiety. Moreover, harsh fathering has a greater effect on adolescents' social anxiety than harsh mothering, especially for girls. CONCLUSIONS: Cognitive reactivity in conjunction with emotional dysfunction can better account for the relationship from harsh fathering and harsh mothering to adolescents' social anxiety.


Assuntos
Pai , Poder Familiar , Adolescente , Ansiedade/psicologia , Criança , Cognição , Pai/psicologia , Feminino , Humanos , Masculino , Mães/psicologia , Poder Familiar/psicologia
16.
Materials (Basel) ; 15(3)2022 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-35160918

RESUMO

The smart meta-superconductor MgB2 and Bi(Pb)SrCaCuO increase the superconducting transition temperature (TC), but the changes in the transport critical current density (JC) and Meissner effect are still unknown. Here, we investigated the JC and Meissner effect of smart meta-superconductor MgB2 and Bi(Pb)SrCaCuO. The use of the standard four-probe method shows that Y2O3:Eu3+ and Y2O3:Eu3++Ag inhomogeneous phase significantly increase the JC, and JC decreases to a minimum value at a higher temperature. The Meissner effect was measured by direct current magnetization. The doping of Y2O3:Eu3+ and Y2O3:Eu3++Ag luminescent inhomogeneous phase causes a Meissner effect of MgB2 and Bi(Pb)SrCaCuO at a higher temperature, while the non-luminescent dopant reduces the temperature at which samples have Meissner effect. The introduction of luminescent inhomogeneous phase in conventional MgB2 and copper oxide high-temperature Bi(Pb)SrCaCuO superconductor increases the TC and JC, and Meissner effect is exerted at higher temperature. Therefore, smart meta-superconductivity is suitable for conventional and copper oxide high-temperature superconductors.

17.
J Interpers Violence ; 36(21-22): 9904-9923, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-31608734

RESUMO

Although negative parenting and attachment insecurity have been demonstrated to place children at risk for social anxiety, the different roles of fathers and mothers in this association need to be further clarified. This study examined the different mediating roles of attachment insecurity with fathers and mothers in the association between harsh parenting and social anxiety among Chinese adolescents. A sample of 395 students in the sixth through eighth grades with their parents was enlisted as participants of this survey from two public middle schools located in Northern China. Parents were required to report on their harsh parenting, and students were asked to report on their social anxiety and perceived attachment insecurity with both parents. The results demonstrated that both paternal harsh parenting and maternal harsh parenting were positively associated with attachment insecurity with both parents. More importantly, we found that attachment insecurity with mothers partially mediated the association between maternal harsh parenting and adolescent social anxiety but completely mediated the relation of paternal harsh parenting to adolescent social anxiety. These results expanded extant understandings on the associations among harsh parenting, attachment insecurity, and child social anxiety by taking the different roles of both parents into consideration.


Assuntos
Pai , Poder Familiar , Adolescente , Ansiedade/epidemiologia , China , Feminino , Humanos , Masculino , Mães
18.
Nanomaterials (Basel) ; 11(5)2021 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-33919085

RESUMO

A smart meta-superconductor Bi(Pb)SrCaCuO (B(P)SCCO) may increase the critical transition temperature (TC) of B(P)SCCO by electroluminescence (EL) energy injection of inhomogeneous phases. However, the increase amplitude ΔTC (ΔTC=TC-TC,pure) of TC is relatively small. In this study, a smart meta-superconductor B(P)SCCO with different matrix sizes was designed. Three kinds of raw materials with different particle sizes were used, and different series of Y2O3:Sm3+, Y2O3, Y2O3:Eu3+, and Y2O3:Eu3++Ag-doped samples and pure B(P)SCCO were prepared. Results indicated that the TC of the Y2O3 or Y2O3:Sm3+ non-luminescent dopant doping sample is lower than that of pure B(P)SCCO. However, the TC of the Y2O3:Eu3++Ag or Y2O3:Eu3+ luminescent inhomogeneous phase doping sample is higher than that of pure B(P)SCCO. With the decrease of the raw material particle size from 30 to 5 µm, the particle size of the B(P)SCCO superconducting matrix in the prepared samples decreases, and the doping content of the Y2O3:Eu3++Ag or Y2O3:Eu3+ increases from 0.2% to 0.4%. Meanwhile, the increase of the inhomogeneous phase content enhances the ΔTC. When the particle size of raw material is 5 µm, the doping concentration of the luminescent inhomogeneous phase can be increased to 0.4%. At this time, the zero-resistance temperature and onset transition temperature of the Y2O3:Eu3++Ag doped sample are 4 and 6.3 K higher than those of pure B(P)SCCO, respectively.

19.
Int J Biol Macromol ; 184: 144-158, 2021 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-34089759

RESUMO

Wound healing is a complicated process that influences patient's life quality. Plant-based polysaccharide has recently gained interest in its use in wound dressing materials because of its biological compatibility, natural abundance, and ideal physiochemical properties. The present study reveals the potential of polysaccharide isolated from Moringa oleifera seed (MOS-PS) and its nanocomposite with silver (MOS-PS-AgNPs) as alternative materials for wound dressing. First, MOS-PS was isolated and structurally characterized by TLC, HPLC, FTIR, NMR, and GPC analyses. A green and simple method was used to synthesize AgNPs using MOS-PS as a stabilizing and reducing agent. The size, morphology, and structure of the MOS-PS-AgNPs were characterized by UV-Vis spectroscopy, X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and zeta potential analysis. The results showed that the MOS-PS-AgNPs were spherically shaped, having no cytotoxicity toward mouse fibroblasts cells and promoting their in-vitro migration. Moreover, the MOS-PS-AgNPs displayed strong anti-microbial activity against wound infectious pathogenic bacteria. Finally, the MOS-PS-AgNPs were used for dressing animal wounds and its preliminary mechanism was studied by RT-PCR and histological analysis. The results showed that the MOS-PS-AgNPs can promote wound contraction and internal tissue growth well. Overall, our results indicated that the MOS-PS-AgNPs might be an excellent candidate for use as an optimal wound dressing material.


Assuntos
Antibacterianos/administração & dosagem , Moringa oleifera/química , Polissacarídeos/química , Prata/administração & dosagem , Infecção dos Ferimentos/tratamento farmacológico , Animais , Antibacterianos/química , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Bandagens , Linhagem Celular , Movimento Celular/efeitos dos fármacos , Modelos Animais de Doenças , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Química Verde , Masculino , Nanopartículas Metálicas , Camundongos , Testes de Sensibilidade Microbiana , Nanocompostos , Tamanho da Partícula , Extratos Vegetais/química , Ratos , Sementes/química , Prata/química , Prata/farmacologia , Cicatrização
20.
Chemistry ; 16(19): 5723-35, 2010 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-20391566

RESUMO

Ruthenium porphyrins (particularly [Ru(2,6-Cl(2)tpp)CO]; tpp=tetraphenylporphinato) and RuCl(3) can act as oxidation and/or Lewis acid catalysts for direct C-3 alkylation of indoles, giving the desired products in high yields (up to 82% based on 60-95% substrate conversions). These ruthenium compounds catalyze oxidative coupling reactions of a wide variety of anilines and indoles bearing electron-withdrawing or electron-donating substituents with high regioselectivity when using tBuOOH as an oxidant, resulting in the alkylation of N-arylindoles to 3-{[(N-aryl-N-alkyl)amino]methyl}indoles (yield: up to 82%, conversion: up to 95%) and the alkylation of N-alkyl or N-H indoles to 3-[p-(dialkylamino)benzyl]indoles (yield: up to 73%, conversion: up to 92%). A tentative reaction mechanism involving two pathways is proposed: an iminium ion intermediate may be generated by oxidation of an sp(3) C-H bond of the alkylated aniline by an oxoruthenium species; this iminium ion could then either be trapped by an N-arylindole (pathway A) or converted to formaldehyde, allowing a subsequent three-component coupling reaction of the in situ generated formaldehyde with an N-alkylindole and an aniline in the presence of a Lewis acid catalyst (pathway B). The results of deuterium-labeling experiments are consistent with the alkylation of N-alkylindoles via pathway B. The relative reaction rates of [Ru(2,6-Cl(2)tpp)CO]-catalyzed oxidative coupling reactions of 4-X-substituted N,N-dimethylanilines with N-phenylindole (using tBuOOH as oxidant), determined through competition experiments, correlate linearly with the substituent constants sigma (R(2)=0.989), giving a rho value of -1.09. This rho value and the magnitudes of the intra- and intermolecular deuterium isotope effects (k(H)/k(D)) suggest that electron transfer most likely occurs during the initial stage of the oxidation of 4-X-substituted N,N-dimethylanilines. Ruthenium-catalyzed three-component reaction of N-alkyl/N-H indoles, paraformaldehyde, and anilines gave 3-[p-(dialkylamino)benzyl]indoles in up to 82% yield (conversion: up to 95%).


Assuntos
Aminas/química , Indóis/química , Metaloporfirinas/química , Rutênio/química , Alquilação , Catálise , Ligação de Hidrogênio , Modelos Químicos , Oxirredução , Estereoisomerismo
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