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1.
J Health Psychol ; 29(4): 266-274, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37840285

RESUMO

Caring for children with cancer is stressful for parents and leads to psychological distress, which is mainly manifested as depressive symptoms and anxiety. This study explored the mediating role of resilience in the relationship between stress and psychological distress in parents of children with cancer. We recruited 258 parents of children with cancer in three tertiary hospitals in Mainland China. The results revealed that the mediating effect of resilience for the relationships between stress and depressive symptoms and between stress and anxiety accounted for 23.4% and 11.4%, respectively, of the total effect. Resilience was confirmed as a protective factor that can be incorporated into future intervention programmes to improve the psychological well-being of parents of children with cancer. Future studies could develop resilience training programmes to enhance the resilience of parents of children with cancer to alleviate parents' psychological distress.


Assuntos
Neoplasias , Resiliência Psicológica , Criança , Humanos , Estresse Psicológico/psicologia , Neoplasias/psicologia , Pais/psicologia , Ansiedade
2.
Nat Commun ; 14(1): 3383, 2023 06 08.
Artigo em Inglês | MEDLINE | ID: mdl-37291168

RESUMO

The hexosamine biosynthetic pathway (HBP) produces uridine diphosphate N-acetylglucosamine (UDP-GlcNAc) to facilitate O-linked GlcNAc (O-GlcNAc) protein modifications, and subsequently enhance cell survival under lethal stresses. Transcript induced in spermiogenesis 40 (Tisp40) is an endoplasmic reticulum membrane-resident transcription factor and plays critical roles in cell homeostasis. Here, we show that Tisp40 expression, cleavage and nuclear accumulation are increased by cardiac ischemia/reperfusion (I/R) injury. Global Tisp40 deficiency exacerbates, whereas cardiomyocyte-restricted Tisp40 overexpression ameliorates I/R-induced oxidative stress, apoptosis and acute cardiac injury, and modulates cardiac remodeling and dysfunction following long-term observations in male mice. In addition, overexpression of nuclear Tisp40 is sufficient to attenuate cardiac I/R injury in vivo and in vitro. Mechanistic studies indicate that Tisp40 directly binds to a conserved unfolded protein response element (UPRE) of the glutamine-fructose-6-phosphate transaminase 1 (GFPT1) promoter, and subsequently potentiates HBP flux and O-GlcNAc protein modifications. Moreover, we find that I/R-induced upregulation, cleavage and nuclear accumulation of Tisp40 in the heart are mediated by endoplasmic reticulum stress. Our findings identify Tisp40 as a cardiomyocyte-enriched UPR-associated transcription factor, and targeting Tisp40 may develop effective approaches to mitigate cardiac I/R injury.


Assuntos
Hexosaminas , Traumatismo por Reperfusão , Animais , Masculino , Camundongos , Vias Biossintéticas , Hexosaminas/metabolismo , Isquemia/metabolismo , Miócitos Cardíacos/metabolismo , Traumatismo por Reperfusão/metabolismo , Espermatogênese , Fatores de Transcrição/metabolismo
3.
Pharmacogenomics ; 24(7): 425-434, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-37212851

RESUMO

Aim: To assess the role of genetic polymorphisms in postoperative imatinib concentrations and edema in patients with gastrointestinal stromal tumor. Methods: The relationships between genetic polymorphisms, imatinib concentrations and edema were explored. Results: Carriers of the rs683369 G-allele and rs2231142 T-allele had significantly higher imatinib concentrations. Grade ≥2 periorbital edemas were related to the carriership of two C-alleles in rs2072454 with an adjusted odds ratio of 2.85, two T-alleles in rs1867351 with an adjusted odds ratio of 3.42 and two A-alleles in rs11636419 with an adjusted odds ratio of 3.15. Conclusion: rs683369 and rs2231142 affect the metabolism of imatinib; rs2072454, rs1867351 and rs11636419 are related to grade ≥2 periorbital edemas.


Assuntos
Antineoplásicos , Tumores do Estroma Gastrointestinal , Adulto , Humanos , Mesilato de Imatinib/efeitos adversos , Tumores do Estroma Gastrointestinal/tratamento farmacológico , Tumores do Estroma Gastrointestinal/genética , Antineoplásicos/uso terapêutico , Polimorfismo Genético , Edema/genética
4.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-970742

RESUMO

Occupational exposure to diacetyl can lead to bronchiolitis obliterans. In this paper, two patients with severe obstructive ventilation disorder who were exposed to diacetyl at a fragrance and flavours factory were analyzed. The clinical manifestations were cough and shortness of breath. One of them showed Mosaic shadows and uneven perfusion in both lungs on CT, while the other was normal. Field investigation found that 4 of the 8 workers in the factory were found to have obstructive ventilation disorder, and 2 had small airway dysfunction. This paper summarizes the diagnostic process of patients in order to improve the understanding of airway dysfunction caused by occupational exposure to diacetyl and promote the development of relevant standards.


Assuntos
Humanos , Diacetil/efeitos adversos , Doenças Profissionais/diagnóstico , Exposição Ocupacional/efeitos adversos , Pulmão , Bronquiolite Obliterante/diagnóstico
5.
Molecules ; 27(21)2022 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-36364410

RESUMO

Chalcone-1-deoxynojirimycin heterozygote (DC-5), a novel compound which was designed and synthesized in our laboratory for diabetes treatment, showed an extremely strong in vitro inhibitory activity on α-glucosidase in our previous studies. In the current research, its potential in vivo anti-diabetic effects were further investigated by integration detection and the analysis of blood glucose concentration, blood biochemical parameters, tissue section and gut microbiota of the diabetic rats. The results indicated that oral administration of DC-5 significantly reduced the fasting blood glucose and postprandial blood glucose, both in diabetic and normal rats; meanwhile, it alleviated the adverse symptoms of elevated blood lipid level and lipid metabolism disorder in diabetic rats. Furthermore, DC-5 effectively decreased the organ coefficient and alleviated the pathological changes of the liver, kidney and small intestine of the diabetic rats at the same time. Moreover, the results of 16S rDNA gene sequencing analysis suggested that DC-5 significantly increased the ratio of Firmicutes to Bacteroidetes and improved the disorder of gut microbiota in diabetic rats. In conclusion, DC-5 displayed a good therapeutic effect on the diabetic rats, and therefore had a good application prospect in hypoglycemic drugs and foods.


Assuntos
Chalcona , Chalconas , Diabetes Mellitus Experimental , Diabetes Mellitus Tipo 2 , Microbioma Gastrointestinal , Ratos , Animais , Glicemia , Diabetes Mellitus Experimental/patologia , 1-Desoxinojirimicina/farmacologia , 1-Desoxinojirimicina/uso terapêutico , Chalconas/farmacologia , Chalconas/uso terapêutico , Chalcona/farmacologia , Heterozigoto , Hipoglicemiantes/farmacologia , Hipoglicemiantes/uso terapêutico , Diabetes Mellitus Tipo 2/tratamento farmacológico
6.
Bio Protoc ; 12(1): e4282, 2022 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-35118174

RESUMO

Many of the current methods for enzyme purification and immobilization suffer from several drawbacks, such as requiring tedious multistep procedures or long preparation, and being environmentally unfriendly, due to the chemicals and conditions involved. Thus, a simple technique for direct purification and immobilization of target enzymes from cell lysates was proposed. The elastin-like polypeptides (ELPs)-SpyCatcher chimera could mediate the formation of silica carriers within seconds and the target enzymes were then covalently immobilized on silica carriers via SpyCatcher/SpyTag spontaneous reaction. These tailor-made carriers were easily prepared, with precisely controlled morphology and size, as well as none-consuming surface modification needed, which could specifically immobilize the SpyTag-fused target enzymes from the cell lysate without pre-purification.

7.
Eur J Surg Oncol ; 48(5): 1173-1180, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-34972620

RESUMO

BACKGROUND: To explore the most predictive lymph node (LN) scheme for stage IIIC endometrial cancer (EC) patients after hysterectomy and develop a scheme-based nomogram. METHODS: Data from 2626 stage IIIC EC patients, diagnosed between 2010 and 2014, were extracted from the Surveillance, Epidemiology, and End Results (SEER) registry. The predictive ability of four LN schemes was assessed using C-index and Akaike information criterion (AIC). A nomogram based on the most predictive LN scheme was constructed and validated. The comparison of the predictive ability between nomogram and FIGO stage was conducted using the area under the receiver operating characteristic curve (AUC) and decision curve analysis (DCA). RESULTS: FIGO stage (stage IIIC1/stage IIIC2) was not an independent risk factor for OS in stage IIIC EC patients (P = 0.672) and log odds of positive lymph nodes (LODDS) had the best predictive ability (C-index: 0.742; AIC: 8228.95). A nomogram based on LODDS was constructed and validated, which had a decent C-index of 0.742 (0.723-0.762). The nomogram showed a better predictive ability than that of the FIGO staging system. CONCLUSION: FIGO IIIC1/FIGO IIIC2 could not differentiate the prognosis for stage IIIC EC patients. We developed and validated a nomogram based on LODDS to predict OS for post-operative patients with stage IIIC EC.


Assuntos
Neoplasias do Endométrio , Neoplasias do Endométrio/patologia , Neoplasias do Endométrio/cirurgia , Feminino , Humanos , Linfonodos/patologia , Estadiamento de Neoplasias , Nomogramas , Prognóstico , Fatores de Risco
8.
Food Sci Biotechnol ; 31(1): 49-59, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35059229

RESUMO

Slowly digestible gorgon nut starch (GN-SDS) was prepared by heating-cooling treatment (HCT), meanwhile its morphological and structural features were characterized in detail by SEM, DSC, XRD and IR detection. The optimized parameters of GN-SDS processing were as following: starch milk (20%) was heated at 100 °C for 20 min, and then cooled under 4 °C for 24 h. Under the optimized parameters, the SDS content increased from 20.49 to 61.74%. GN-SDS showed typical SDS characteristics in in vivo digestion with a low postprandial blood glucose. SEM images suggested that GN-S particles changed from uniform regular polyhedron with smooth surface to irregular gravel-like particles with coarse surface and obvious layered structure inside after HCT. The results of SEM, DSC, XRD and IR determination indicated that HCT changed the granule morphology, interior structure, gelatinization temperature and crystal type (A to B-type) of GN-S, and therefore made it hard to be digested accordingly. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10068-021-01007-6.

9.
J Clin Pharm Ther ; 47(5): 600-608, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-34802160

RESUMO

WHAT IS KNOWN AND OBJECTIVES: Tacrolimus (TAC), a first-line immunosuppressant in solid-organ transplant, has a narrow therapeutic window and large inter-individual variability, which affects its use in clinical practice. Successful predictions using machine learning algorithms have been reported in several fields. However, a comparison of 10 machine learning model-based TAC pharmacogenetic and pharmacokinetic dosing algorithms for kidney transplant perioperative patients of Chinese descent has not been reported. The objective of this study was to screen and establish an appropriate machine learning method to predict the individualized dosages of TAC for perioperative kidney transplant patients. METHODS: The records of 2551 patients were collected from three transplant centres, 80% of which were randomly selected as a 'derivation cohort' to develop the dose prediction algorithm, while the remaining 20% constituted a 'validation cohort' to validate the final algorithm selected. Important features were screened according to our previously established population pharmacokinetic model of tacrolimus. The performances of the algorithms were evaluated and compared using R-squared and the mean percentage in the remaining 20% of patients. RESULTS AND DISCUSSION: This study identified several factors influencing TAC dosage, including CYP3A5 rs776746, CYP3A4 rs4646437, haematocrit, Wuzhi capsules, TAC daily dose, age, height, weight, post-operative time, nifedipine and the medication history of the patient. According to our results, among the 10 machine learning models, the extra trees regressor (ETR) algorithm showed the best performance in the training set (R-squared: 1, mean percentage within 20%: 100%) and test set (R-squared: 0.85, mean percentage within 20%: 92.77%) of the derivation cohort. The ETR model successfully predicted the ideal TAC dosage in 97.73% of patients, especially in the intermediate dosage range (>5 mg/day to <8 mg/day), whereby the ideal TAC dosage could be successfully predicted in 99% of the patients. WHAT IS NEW AND CONCLUSION: The results indicated that the ETR algorithm, which was chosen to establish the dose prediction model, performed better than the other nine machine learning models. This study is the first to establish ETR algorithms to predict TAC dosage. This study will further promote the individualized medication of TAC in kidney transplant patients in the future, which has great significance in ensuring the safety and effectiveness of drug use.


Assuntos
Transplante de Rim , Tacrolimo , China , Citocromo P-450 CYP3A/genética , Genótipo , Humanos , Imunossupressores , Aprendizado de Máquina
10.
J Med Internet Res ; 23(11): e27639, 2021 11 29.
Artigo em Inglês | MEDLINE | ID: mdl-34847060

RESUMO

BACKGROUND: Caring for children with cancer can be a stressful experience for parents and may have negative effects on their physical and psychological well-being. Although evidence has shown that resilience is associated with positive psychological well-being, few interventions have been specifically designed to enhance the resilience of parents of children with cancer. OBJECTIVE: The aim of this study is to examine the effectiveness of a mobile device-based resilience training program in reducing depressive symptoms and enhancing resilience and quality of life (QoL) in parents of children with cancer. METHODS: Parents of children diagnosed with cancer were recruited from the pediatric oncology wards of 3 tertiary hospitals in China. The participants were randomly assigned to either the experimental group (52/103, 50.5%) to undergo an 8-week mobile device-based resilience training program or to the control group (51/103, 49.5%) to receive an 8-week program of placebo information. The study outcomes included resilience, depressive symptoms, and QoL, as measured by the Connor-Davidson Resilience Scale, the Self-Rating Depression Scale, and the Short Form of the 6-Dimension Health Survey, respectively. All data were collected at baseline and at 2 and 6 months of follow-up. The data analysis followed the intention-to-treat principle. A generalized estimating equation was used to examine the effects of the intervention. RESULTS: The participants were mostly female (72/103, 69.9%), and their mean age was 33.6 (SD 5.2) years. The participants in the experimental group showed significantly higher levels of resilience (mean 67.96, SD 15.8 vs mean 58.27, SD 19.0; P<.001) and lower levels of depressive symptoms (mean 40.17, SD 9.9 vs mean 46.04, SD 10.9; P<.001) than those in the control group at 6 months of follow-up. The intervention showed statistically significant effects in improving resilience (ß=6.082; P=.01) and decreasing depressive symptoms (ß=-2.772; P=.04) relative to the control group. The QoL score in the experimental group was higher than that in the control group at 6 months of follow-up (mean 0.79, SD 0.2 vs mean 0.76, SD 0.3; P=.07); however, no statistically significant intervention effect was detected (ß=.020; P=.38). CONCLUSIONS: The mobile device-based resilience training program effectively enhanced resilience and alleviated depressive symptoms in parents of children with cancer. It is highly recommended that health care professionals incorporate this resilience training program when providing psychological care to parents of children with cancer. TRIAL REGISTRATION: Clinical.Trials.gov NCT04038242; http://clinicaltrials.gov/ct2/show/NCT04038242.


Assuntos
Neoplasias , Qualidade de Vida , Adulto , Criança , Computadores de Mão , Depressão/prevenção & controle , Feminino , Humanos , Masculino , Pais
11.
Cell Death Dis ; 12(7): 624, 2021 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-34135313

RESUMO

Proteasomal activity is compromised in diabetic hearts that contributes to proteotoxic stresses and cardiac dysfunction. Osteocrin (OSTN) acts as a novel exercise-responsive myokine and is implicated in various cardiac diseases. Herein, we aim to investigate the role and underlying molecular basis of OSTN in diabetic cardiomyopathy (DCM). Mice received a single intravenous injection of the cardiotrophic adeno-associated virus serotype 9 to overexpress OSTN in the heart and then were exposed to intraperitoneal injections of streptozotocin (STZ, 50 mg/kg) for consecutive 5 days to generate diabetic models. Neonatal rat cardiomyocytes were isolated and stimulated with high glucose to verify the role of OSTN in vitro. OSTN expression was reduced by protein kinase B/forkhead box O1 dephosphorylation in diabetic hearts, while its overexpression significantly attenuated cardiac injury and dysfunction in mice with STZ treatment. Besides, OSTN incubation prevented, whereas OSTN silence aggravated cardiomyocyte apoptosis and injury upon hyperglycemic stimulation in vitro. Mechanistically, OSTN treatment restored protein kinase G (PKG)-dependent proteasomal function, and PKG or proteasome inhibition abrogated the protective effects of OSTN in vivo and in vitro. Furthermore, OSTN replenishment was sufficient to prevent the progression of pre-established DCM and had synergistic cardioprotection with sildenafil. OSTN protects against DCM via restoring PKG-dependent proteasomal activity and it is a promising therapeutic target to treat DCM.


Assuntos
Apoptose/efeitos dos fármacos , Cardiomiopatias Diabéticas/prevenção & controle , Proteínas Musculares/farmacologia , Miócitos Cardíacos/efeitos dos fármacos , Complexo de Endopeptidases do Proteassoma/metabolismo , Fatores de Transcrição/farmacologia , Animais , Células Cultivadas , Proteínas Quinases Dependentes de GMP Cíclico/metabolismo , Cardiomiopatias Diabéticas/enzimologia , Cardiomiopatias Diabéticas/patologia , Modelos Animais de Doenças , Proteína Forkhead Box O1/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Proteínas Musculares/genética , Proteínas Musculares/metabolismo , Miócitos Cardíacos/enzimologia , Miócitos Cardíacos/patologia , Fosforilação , Estudo de Prova de Conceito , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ratos , Proteínas Recombinantes/farmacologia , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
13.
J Int Med Res ; 48(9): 300060520952256, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32910698

RESUMO

Since the outbreak of coronavirus disease 2019 (COVID-19) in December 2019, an epidemic has spread rapidly worldwide. COVID-19 is caused by the highly infectious severe acute respiratory syndrome coronavirus-2. A 42-year-old woman presented to hospital who was suffering from epigastric discomfort and dyspepsia for the past 5 days. Before the onset of symptoms, she was healthy, and had no travel history to Wuhan or contact with laboratory-confirmed COVID-19 cases. An examination showed chronic superficial gastritis with erosion and esophagitis. Enhanced magnetic resonance imaging of the abdomen showed a lesion in the right lower lobe of the lungs. Chest computed tomography showed multiple ground-glass opacity in the lungs. Reverse transcription-polymerase chain reaction was negative for severe acute respiratory syndrome coronavirus-2. There was no improvement after antibiotic treatment. Polymerase chain reaction performed 2 days later was positive and she was diagnosed with COVID-19. After several days of antiviral and symptomatic treatments, her symptoms improved and she was discharged. None of the medical staff were infected. Clinical manifestations of COVID-19 are nonspecific, making differentiating it from other diseases difficult. This case shows the sequence in which symptoms developed in a patient with COVID-19 with gastrointestinal symptoms as initial manifestations.


Assuntos
Betacoronavirus/isolamento & purificação , Infecções por Coronavirus/complicações , Gastroenteropatias/diagnóstico , Gastroenteropatias/virologia , Pneumonia Viral/complicações , Adulto , COVID-19 , Infecções por Coronavirus/transmissão , Infecções por Coronavirus/virologia , Feminino , Gastroenteropatias/patologia , Humanos , Pandemias , Pneumonia Viral/transmissão , Pneumonia Viral/virologia , Prognóstico , SARS-CoV-2
14.
Nanoscale ; 12(14): 7864-7869, 2020 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-32227024

RESUMO

Single crystals of a small bimetallic Ag3Cu2 nanocluster protected by six ligands of 2,4-dimethylbenzene thiol are synthesized by a one-pot procedure of wet chemistry. This Ag3Cu2 nanocluster bears a trigonal bipyramid metallic core with two copper atoms located on both sides of a triangular Ag3. Interestingly, the six Cu-Ag side edges of the trigonal bipyramid are fully protected by the six ligands giving rise to reinforced stability and high chemical purity. More interestingly, this Ag3Cu2 cluster shows strong dual fluorescence emissions in both ultraviolet visible (UV-vis) and near infrared (NIR) regions. Theoretical calculations reproduce the absorption and fluorescence spectra where the NIR emission at 824 nm is assigned to the S1→ S0 transition, while the simultaneous emission in the visible band is due to the radiation of highly excited states and is against Kasha's rule.

15.
Angew Chem Int Ed Engl ; 58(36): 12580-12584, 2019 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-31310447

RESUMO

Chlorosilanes are versatile reagents in organic synthesis and material science. A mild pathway is now reported for the quantitative conversion of hydrosilanes to silyl chlorides under visible-light irradiation using neutral eosin Y as a hydrogen-atom-transfer photocatalyst and dichloromethane as a chlorinating agent. Stepwise chlorination of di- and trihydrosilanes was achieved in a highly selective fashion assisted by continuous-flow micro-tubing reactors. The ability to access silyl radicals using photocatalytic Si-H activation promoted by eosin Y offers new perspectives for the synthesis of valuable silicon reagents in a convenient and green manner.

16.
Chemotherapy ; 64(4): 177-186, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31935733

RESUMO

INTRODUCTION: This study aims to explore the relationship betweenextracellular histone and prostate cancer and its mechanism. METHODS: Migration of prostate cancer cells was detected by Transwell. Inflammatory factor expression was investigated by ELISA. Epithelial-mesenchymal transition and expression of NF-κB pathway-related proteins were investigated using Western blotting. RESULTS: Under the induction of extracellular histones, the migration rate of prostate cancer cells and the levels of IL-1ß, TNF-α, and IL-6 were notably enhanced. Then, expression of E-cadherin was significantly down-regulated, while levels of N-cadherin, vimentin, ß-catenin, Snail, p-p65 and p-IκBα were significantly up-regulated, which was reversed by PDTC (pyrrolidine dithiocarbamate). CONCLUSION: Extracellular histone significantly promotes the progression of prostate cancer cells via NF-κB pathway-mediated inflammatory responses, which may serve as a novel target for treating prostate cancer.


Assuntos
Transição Epitelial-Mesenquimal/efeitos dos fármacos , Histonas/farmacologia , NF-kappa B/metabolismo , Caderinas/metabolismo , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Regulação para Baixo/efeitos dos fármacos , Humanos , Masculino , Inibidor de NF-kappaB alfa/metabolismo , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , Transdução de Sinais/efeitos dos fármacos , Fator de Transcrição RelA/metabolismo , Regulação para Cima/efeitos dos fármacos
17.
J Am Chem Soc ; 140(44): 15099-15113, 2018 11 07.
Artigo em Inglês | MEDLINE | ID: mdl-30362731

RESUMO

A recent experimental study reported a visible-light-mediated aerobic oxidative coupling reaction of phenol with alkynes that produces hydroxyl-functionalized aryl ketones using inexpensive CuCl as catalyst under mild conditions. Here we apply the complete active space self-consistent field (CASSCF) method and multistate second-order perturbation (MS-CASPT2) theory in combination with density functional theory (DFT) to systematically explore the entire photocatalytic reaction between phenol and phenylacetylene in acetonitrile solution in the presence of molecular oxygen and CuCl. Our main findings are as follows: (1) The visible-light-driven conversion of phenylacetylene to PhCCCu(I) occurs thermally because of efficient excited-state deactivation to the S0 state. (2) The single electron transfer from PhCCCu(I) to molecular oxygen that leads to the PhCCCu(II) cation takes place in the T1 state after an efficient S1 → T1 intersystem crossing. (3) During the initial oxidation of phenol, molecular oxygen prefers to attack the para position of the phenol radical intermediate to produce 1,4-benzoquinone, which further reacts with PhCCCu(II) to generate para-hydroxyl-substituted aryl ketones; this is the origin of the experimentally observed regioselectivity. (4) The C≡C bond of the phenylacetylene moiety is not activated by the triplet-state single electron transfer from PhCCCu(I) to molecular oxygen but is cleaved at a later stage, in the [2+2] cycloaddition between PhCCCu(II) and 1,4-benzoquinone. (5) The substrate phenol plays an active role in several hydrogen transfer and decarboxylation reactions; the barriers to these phenol-assisted reactions are lower than those for the corresponding direct or water-assisted reactions, which explains the experimental finding that adding water does not enhance the photocatalytic reaction yield. In summary, while supporting the general features of the experimentally proposed mechanism, our computational study provides detailed mechanistic insights that should be useful for understanding and further improving visible-light-induced copper-catalyzed coupling reactions.

18.
Phys Chem Chem Phys ; 20(23): 16138-16150, 2018 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-29854994

RESUMO

Herein, we employed combined CASPT2 and B3LYP electronic structure methods in the framework of the quantum mechanics/molecular mechanics (QM/MM) approach to explore the ozonolysis of α-humulene and subsequent Criegee reactions with acids and water at the air-water/acetonitrile interface as a surrogate for atmospheric aqueous organic media. First, we found that the 1,3-cycloaddition reactions of ozone on α-humulene proceed concertedly and have small barriers (less than 2.5 kcal mol-1) at the QM(CASPT2)/MM level. Second, the five-membered ring cleavage reactions of the generated ozonides are rate-limiting steps and have considerable barriers (more than 10.0 kcal mol-1). These ring-opening reactions are also concerted and simultaneously lead to the cleavage of O-O and C-C bonds, producing sesquiterpene Criegee intermediates at the air-water/acetonitrile interface. Third, although these Criegee intermediates can react with water and acids near the air-water/acetonitrile boundary, the addition reactions with acids have smaller barriers, which range from 2.7 kcal mol-1 of R1-COOH to 5.6 kcal mol-1 of R7-COOH. In contrast, in water addition reactions, several different water-mediated reaction pathways have been disclosed. Their reaction barriers are found to decrease remarkably with an increase in the number of water molecules involved in the reactions. Finally, we found that in addition to low water concentration near the air-water/acetonitrile boundary, distinct reactivities of Criegee intermediates with acids and water play very important roles in the determination of the fates of the Criegee intermediates. Our present QM/MM study provides new mechanistic insights into ozonolysis and Criegee reactions at air-water/acetonitrile interfaces and gives important implications for new particle formation and secondary organic aerosol formation near the marine boundary.

19.
Angew Chem Int Ed Engl ; 57(31): 9965-9969, 2018 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-29786934

RESUMO

The weak photoluminescence of silver nanoclusters prevents their broad application as luminescent nanomaterials. Recent experiments, however, have shown that gold doping can significantly enhance the photoluminescence intensity of Ag29 nanoclusters but the molecular and physical origins of this effect remain unknown. Therefore, we have computationally explored the geometric and electronic structures of Ag29 and gold-doped Ag29-x Aux (x=1-5) nanoclusters in the S0 and S1 states. We found that 1) relativistic effects that are mainly due to the Au atoms play an important role in enhancing the fluorescence intensity, especially for highly doped Ag26 Au3 , Ag25 Au4 , and Ag24 Au5 , and that 2) heteronuclear Au-Ag bonds can increase the stability and regulate the fluorescence intensity of isomers of these gold-doped nanoclusters. These novel findings could help design doped silver nanoclusters with excellent luminescence properties.

20.
Biochim Biophys Acta Mol Basis Dis ; 1864(9 Pt B): 2769-2784, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29751081

RESUMO

Leukemia inhibitory factor receptor (LIFR) has been documented as a cancer promoter and to be present at high levels in various types of tumor tissues. In our search for molecules prognostic of colorectal cancer (CRC), we found high levels of LIFR in CRC tissue samples. Further analyses revealed that LIFR was indeed prognostic of CRC patient survival, and was associated with tumor size, lymphatic metastasis and stages. LIFR was found to promote tumor growth, metastasis and angiogenesis both in vitro and in vivo. High levels of LIFR in CRC facilitated proliferation and migration of endothelial cells, resulting in an increase in angiogenic activity. Moreover, interleukin 8 (IL-8) was found to play a role in the LIFR induced angiogenesis. IL-8 levels were correlated with LIFR levels in CRC tissues, whereas depletion of IL-8 led to a reduced angiogenic activity of LIFR in CRC cells. In addition, LIFR increased phosphorylation level of Erk, which regulates il-8 transcription. We conclude that LIFR is possibly a valuable prognostic marker for CRC. Our results also implicate a mechanism by which LIFR regulates tumor angiogenesis through Erk/IL-8 pathway, and that LIFR could be a potential therapeutic target for CRC.


Assuntos
Neoplasias Colorretais/irrigação sanguínea , Células Endoteliais/patologia , Interleucina-8/metabolismo , Subunidade alfa de Receptor de Fator Inibidor de Leucemia/metabolismo , Neovascularização Patológica/patologia , Idoso , Animais , Biomarcadores Tumorais/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Neoplasias Colorretais/mortalidade , Neoplasias Colorretais/patologia , Regulação para Baixo , Feminino , Seguimentos , Células Endoteliais da Veia Umbilical Humana , Humanos , Interleucina-8/genética , Subunidade alfa de Receptor de Fator Inibidor de Leucemia/genética , Masculino , Camundongos , Camundongos Nus , Pessoa de Meia-Idade , Neovascularização Patológica/mortalidade , Prognóstico , RNA Interferente Pequeno/metabolismo , Regulação para Cima , Ensaios Antitumorais Modelo de Xenoenxerto
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