Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 10 de 10
Filtrar
1.
Chemistry ; 29(54): e202301826, 2023 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-37369918

RESUMO

We report the development of Pd/Cu-catalyzed selective 2,1-borocarbonylation reactions of aliphatic terminal alkynes with aryldiazonium salts and B2 Pin2 to prepare gem-bis(boryl) ketones in one-pot. A series of corresponding products are obtained with good to excellent yields under a carbon monoxide atmosphere (10 bar). In addition, wide functional-group tolerance can be observed. Preliminary mechanistic studies reveal that ethyl acetate serves as a proton source in the reaction.

2.
Chemistry ; 29(17): e202203079, 2023 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-36573558

RESUMO

A copper-catalyzed three-component coupling reaction has been developed allowing the rapid building of valuable complex highly functionalized ß-polychloromethyl amines from simple styrenes, arylamines, and dichloromethane/chloroform. Using aryldiazonium salts as a radical initiator, a series of corresponding products are obtained with moderate to good yields under a carbon dioxide or nitrogen atmosphere (50 psi). In addition, good functional group tolerance can be observed.

3.
J Org Chem ; 88(7): 4352-4358, 2023 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-36929949

RESUMO

An unprecedented and challenging multicomponent reaction has been developed that allows for the direct transformation of acyl chlorides with alkynes into the corresponding saturated ß-boryl ketones via Pd/Cu-catalyzed coupling and boration with ethyl acetate as the hydrogen sources. Various ß-boryl ketones were synthesized in good to excellent yields with broad functional group tolerance. In addition, the introduction of boron groups into the products provides substantial opportunities for further conversions.

4.
J Org Chem ; 88(8): 5153-5160, 2023 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-36103718

RESUMO

A convenient four-component reaction has been developed that allows for the direct transformation of aryl iodides with alkyl halides into the corresponding aromatic esters and diesters via palladium-catalyzed carbonylation with water as solvent. Various esters and diesters were isolated in moderate to good yields with broad functional group tolerance.

5.
IUCrJ ; 10(Pt 6): 671-677, 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37721769

RESUMO

Five coordination polymers [TM1(absa)(H2O)4]n and [TM2(absa)(bipy)(H2O)]n [TM1 = Zn (1), Co (2); TM2 = Zn (3), Co (4), Cu (5); Na2absa = 5,5'-azobissalicylic acid disodium salt; bipy = 4,4'-bipyride] were synthesized by solvent evaporation under a magnetic field. It is evident that magnetic fields bring significant and noticeable changes to the absa2- ligand orientation and the component movement behaviors to construct coordination polymers. The absa2- ligands bind to the metal ions in bridging coordination mode through the carboxylate groups, in addition to the bipy molecules adopting bridging modes. Photoluminescence measurements indicate that the emissions of compounds 1-5 are at 626, 600, 632, 658 and 682 nm in the solid state, respectively.

6.
Chem Sci ; 13(41): 12122-12126, 2022 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-36349108

RESUMO

A new Pd/Cu-catalyzed carbonylation and borylation of alkynes with aryldiazonium salts toward α-unsubstituted ß-boryl ketones with complete regioselectivity has been developed. This transformation shows broad substrate scope and excellent functional-group tolerance. Moreover, the obtained 1,2-carbonylboration products provide substantial opportunities for further transformations which cannot be obtained by known carbonylation procedures. Preliminary mechanistic studies indicate that the three hydrogen atoms of the products originated from ethyl acetate.

7.
Front Public Health ; 10: 926395, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36091496

RESUMO

Objective: Thousands of healthcare workers on the frontlines who have been battling the COVID-19 pandemic could face emotional and mental health risks even after their critical pandemic work. This study examined the impact of affective rumination on emotional exhaustion and the spillover effect of affective rumination on unhealthy food consumption among healthcare workers during recuperation. Methods: A total of 418 frontline healthcare workers from 10 Chinese medical institutions were recruited through random cluster sampling. A linear mixed model in SPSS25.0 was performed for hierarchical regression to analyze the effect of affective rumination on unhealthy food consumption via emotional exhaustion. A conditional process analysis was employed to investigate the moderating role of family support in the mediating effect of emotional exhaustion. Results: Front-line healthcare workers scored at a medium level on an emotional exhaustion scale (2.45 ± 0.88). Affective rumination mediated by emotional exhaustion had a significant positive predictive effect on unhealthy food consumption. The indirect effect accounted for ~43.9% of the total effect. Family support amplified the effect of emotional exhaustion on unhealthy food consumption (ß = 0.092, p < 0.05). Conclusion: Affective rumination could be a cause of emotional exhaustion and unhealthy food consumption. First-line healthcare workers could be screened for possible emotional exhaustion through the evaluation of affective rumination in order to provide them with targeted interventions. Family support did not prove to be beneficial in all cases as it enhanced the positive effect of emotional exhaustion on unhealthy eating in the current study. Therefore, family support should be carefully integrated in future interventions.


Assuntos
Esgotamento Profissional , COVID-19 , Esgotamento Profissional/psicologia , COVID-19/epidemiologia , Estudos Transversais , Pessoal de Saúde/psicologia , Humanos , Pandemias , Inquéritos e Questionários
8.
BMJ Open ; 12(6): e049191, 2022 06 23.
Artigo em Inglês | MEDLINE | ID: mdl-35738647

RESUMO

OBJECTIVES: This study aimed to examine the influence and conditioning process of hindrance stressors on the emotional exhaustion of the front-line healthcare workers during recuperation, examine the potential mediating process of rumination, and explore the moderating role of organisational and family factors. SETTING: This cross-sectional study was conducted during 12-20 July 2020. Total 418 questionnaires were collected from front-line healthcare workers by random cluster sampling. Hierarchical regression was performed to analyse the mediating effect of affective rumination using SPSS25.0, while PROCESS was used to further investigate the moderating role of servant leadership and family support. PARTICIPANTS: 418 healthcare workers were investigated randomly from front-line medical teams. Inclusion criteria included worked as front-line health workers and participated in the fight against COVID-19 in Hubei; age ≥18 years; normal cognitive and comprehension abilities under physical and mental health; volunteer to participate in this study. Exclusion criteria included recently affected by major events other than COVID-19 or those with a history of neurasthenia and trauma. RESULTS: Using descriptive analysis of average value and SD measured by a five-item scale (MBI-GS), we found that front-line healthcare workers' emotional exhaustion score (2.45±0.88) was at the medium level. Hindrance stressors, mediated by affective rumination, had a significant positive predictive effect on emotional exhaustion. Servant leadership negatively moderated the direct effect of hindrance stressors on emotional exhaustion (ß=-0.106, p<0.01). Family support positively moderated the impact of hindrance stressors on emotional exhaustion (ß=0.082, p<0.05). CONCLUSIONS: During the recuperation period, after successfully controlling COVID-19 at the front line, the first-line healthcare workers should be screened through affective rumination evaluation to gain insight for targeted interventions. We find that servant leadership is beneficial in alleviating emotional exhaustion while family support worsens emotional exhaustion. We suggest that servant leadership should be further promoted in medical organisations, and family support should be applied correctly and cautiously.


Assuntos
Esgotamento Profissional , COVID-19 , Adolescente , Esgotamento Profissional/epidemiologia , Esgotamento Profissional/psicologia , COVID-19/epidemiologia , Estudos Transversais , Pessoal de Saúde/psicologia , Humanos , Estudos Prospectivos
9.
Oncotarget ; 7(51): 84851-84859, 2016 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-27769044

RESUMO

BACKGROUND: Several studies have investigated the diagnostic value of fibulin-3 for malignant pleural mesothelioma (MPM), but the results were various. Therefore, we performed a systematic review and meta-analysis to evaluate the diagnostic value of fibulin-3 for MPM. RESULTS: Eight studies were included in this work. The overall sensitivity of blood fibulin-3 were 0.87 (95% CI, 0.58 - 0.97) and 0.89 (95% CI, 0.77 - 0.95), respectively. The overall sensitivity and specificity of PF fibulin-3 for MPM were 0.73 (95% CI, 0.54 - 0.86) and 0.80 (95% CI, 0.60 - 0.91), respectively. The area under curve of blood and pleural effusion (PF) Fibulin-3 were 0.94 (95% CI, 0.91 - 0.96) 0.83 (95% CI, 0.79 - 0.86), respectively. METHODS: PubMed and EMBASE databases were searched up to July 29, 2016 to verify studies investigating the diagnostic value of fibulin-3 for MPM. The quality of eligible studies was assessed using the revised Quality Assessment for Studies of Diagnostic Accuracy tool (QUADAS-2). The overall sensitivity and specificity were pooled using a bivariate model. CONCLUSION: Fibuoin-3 is a useful diagnostic marker for MPM.


Assuntos
Biomarcadores Tumorais/sangue , Proteínas da Matriz Extracelular/sangue , Neoplasias Pulmonares/diagnóstico , Mesotelioma/diagnóstico , Neoplasias Pleurais/diagnóstico , Humanos , Mesotelioma Maligno , Valor Preditivo dos Testes , Prognóstico , Sensibilidade e Especificidade
10.
Drug Deliv ; 22(5): 598-607, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-24524364

RESUMO

When polyethylene glycol (PEG)ylated liposomes were repeatedly injected into the same animal, the second dose of liposomes would rapidly clear from the bloodstream and enhance accumulation in the liver and spleen, and this phenomenon is called "accelerated blood clearance (ABC)". There are many factors known to influence ABC phenomenon, in this study, we mainly focused on the effects of different phospholipids (PL) types and animal models. The effects of PL types on ABC phenomenon were examined by repeating injection of PEGylated liposomes prepared by five different types of PL (hydrogenated soy phosphatidylcholine, egg sphingomyelin, soybean phosphatidycholin, 1,2-dipalmitoyl-sn-glycero-3-phosphocholine and egg phosphatidycholin) in rats. Dramatically, repeated injection of different types of PL could induce ABC phenomenon altogether. Both t1/2 and AUC of experimental group (EG) were lower significantly than those of control group (CG). Our results also showed that the liver accumulation of second dose increased significantly (p < 0.01) in all EG as compared that of CG. Interestingly, ABC phenomenon of liposomes prepared by unsaturated PL was more obvious than that of saturated PL. All the first dose could induce the antibody (anti-PEG IgM) level increasing significantly (p < 0.01). For different animal models, we found that after repeated injection of PEGylated liposomes, rats, mice, rabbits and guinea pigs could produce ABC phenomenon. Various PL types and animal models could all produce the ABC phenomenon. However, their extent of accelerated clearance differed. ABC phenomenon is possibly a ubiquitous immune phenomenon in life.


Assuntos
Lipossomos/farmacocinética , Fígado/metabolismo , Fosfolipídeos/farmacocinética , Polietilenoglicóis/farmacocinética , 1,2-Dipalmitoilfosfatidilcolina/análogos & derivados , 1,2-Dipalmitoilfosfatidilcolina/farmacocinética , Animais , Anticorpos/imunologia , Cobaias , Imunoglobulina M/imunologia , Taxa de Depuração Metabólica , Camundongos , Modelos Animais , Óvulo , Fosfatidilcolinas/farmacocinética , Coelhos , Ratos , Glycine max , Esfingomielinas/farmacocinética
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa