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1.
Biomed Environ Sci ; 30(3): 170-176, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28427486

RESUMO

OBJECTIVE: We aim to explore the potential association between serum gamma-glutamyl transferase levels and functional outcome after aneurysmal subarachnoid hemorrhage in a Chinese population. METHODS: A total of 386 aneurysmal subarachnoid hemorrhage patients were included in the study from September 2007 to February 2015. Baseline serum gamma-glutamyl transferase levels and 6-month follow-up functional outcomes were determined. A poor outcome was defined as a modified ranking scale score of ⋝ 3. The multivariable logistic model was used to analyze the relationship between serum gamma-glutamyl transferase and clinical outcomes after aneurysmal subarachnoid hemorrhage. RESULTS: The adjusted poor outcome rates of patients with gamma-glutamyl transferase levels of < 30 U/L, 30-50 U/L and ⋝ 50 U/L were 16.7%, 19.6%, and 34.4%, respectively (P < 0.01). The age-sex and multivariable adjusted odds ratios (95% confidence intervals) of poor prognosis comparing the top group (⋝ 50 U/L) with the lowest group (< 30 U/L) were 5.76 (2.74-12.13), 6.64 (2.05-21.52), and 6.36 (1.92-21.02). A significant linear trend existed between gamma-glutamyl transferase level and aneurysmal subarachnoid hemorrhage prognosis. This association was also observed among nondrinkers. CONCLUSION: Patients with higher gamma-glutamyl transferase levels were more likely to have a poor prognosis. Serum gamma-glutamyl transferase can be considered to be an independent predictor of functional outcomes after aneurysmal subarachnoid hemorrhage.


Assuntos
Hemorragia Subaracnóidea/sangue , Hemorragia Subaracnóidea/complicações , gama-Glutamiltransferase/sangue , Idoso , Feminino , Seguimentos , Regulação Enzimológica da Expressão Gênica , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes
2.
Zhen Ci Yan Jiu ; 47(5): 386-92, 2022 May 25.
Artigo em Zh | MEDLINE | ID: mdl-35616411

RESUMO

OBJECTIVE: To observe the effect of electroacupuncture (EA) at "Zusanli" (ST36) on apoptosis of intestinal T lymphocytes, translocation of intestinal bacteria and expression of intestinal Bcl-2 and Bax proteins and intestinal mucosal immune barrier in sepsis rats, so as to explore its underlying mechanism in relieving sepsis. METHODS: SD rats were randomly divided into sham operation (n=6), model (n=15), non-meridian and non-acupoint (non-acupoint, n=15) and acupoint EA(n=15) groups by using random number table method. The sepsis model was established by using cecal ligation and perforation(CLP) method. EA (2 Hz, 2 mA) was applied to bilateral ST36 or non-acupoint for 30 min one hour after modeling, once every day for 3 days. The rats' general conditions and fatality rate in 3 days after modeling were recorded. The liver, spleen and mesenteric lymph nodes were taken for bacterial culture to detect the translocation rate of intestinal bacteria. The small intestinal tissue was taken for observing histopathological changes (Chiu's score: 0-5 points) after HE staining, and for determining the expression levels of Bcl-2 and Bax proteins using Western blot. The intestinal mucosa was sampled for detecting the apop-tosis (apoptotic index) of lymphocytes by using terminal deoxynucleoitidyl transferase-mediated deoxyuridine triphosphate biotin nick end labeling (TUNEL) assay, and the counts of CD4+ and CD8+T cells using flow cytometry. The contents of IL-4 in the small intestine and that of secretory IgA (sIgA) in the small intestinal mucus were determined by using ELISA. RESULTS: After modeling, of the 15 rats in each of the 3 groups, 7, 7 and 2 in the model, non-acupoint and EA groups were dead in the first 3 days, with the fatality rate being 46.67% (7/15), 46.67% (7/15) and 13.33% (2/15), respectively (being obviously lower in the EA group than in the former two groups, P<0.05). Compared with the sham operation group, the incidence of intestinal bacterial translocation, apoptotic index, Chiu's score, and Bax expression were significantly increased (P<0.05), and the percentages of CD4+ and CD8+T cells, IL-4 and sIgA contents and Bcl-2 expression considerably decreased (P<0.05) in the model group. In comparison with the model group, modeling-induced increase of incidence of bacterial translocation, apoptotic index and Bax expression, and decrease of percentages of CD4+ and CD8+T cells, IL-4 and sIgA contents and Bcl-2 expression were reversed (P<0.05) in the EA group. CONCLUSION: EA at ST36 can reduce death rate and intestinal bacteria translocation incidence in sepsis rats, which may be related to its functions in regulating the expression of intestinal Bcl-2 and Bax proteins and inhibiting the apoptosis of intestinal mucosal T lymphocytes, thereby protecting the immune barrier function of intestinal mucosa to reduce the intestinal permeability.


Assuntos
Eletroacupuntura , Sepse , Pontos de Acupuntura , Animais , Apoptose , Imunoglobulina A Secretora , Interleucina-4 , Mucosa Intestinal/metabolismo , Linfócitos/metabolismo , Ratos , Ratos Sprague-Dawley , Sepse/genética , Sepse/terapia , Proteína X Associada a bcl-2/genética
3.
Zhonghua Yan Ke Za Zhi ; 47(7): 589-95, 2011 Jul.
Artigo em Zh | MEDLINE | ID: mdl-22041482

RESUMO

OBJECTIVE: To investigate the changes and relevant factors of forward scatter after Epipolis laser in situ keratomileusis (Epi-LASIK)and laser in situ keratomileusis (LASIK). METHODS: It was a prospective clinical comparative study. 45 patients (45 eyes) were scheduled for Epi-LASIK and 42 patients (42 eyes) for LASIK. Straylight examinations were performed using the C-Quant straylight meter before and 1, 4, 10 months after surgery. The data was analyzed for statistical significance by one-way ANOVA and the correlation was tested by Pearson's test by using SPSS 13.0 software. RESULTS: The straylight values were (0.91 ± 0.17), (1.03 ± 0.15), (1.11 ± 0.13), (1.01 ± 0.16) of Epi-LASIK group and (0.96 ± 0.14), (1.05 ± 0.12), (1.10 ± 0.12), (0.98 ± 0.15) of LASIK group preoperatively and 1, 4, 10 months postoperatively respectively, which there were significant increase postoperatively in both groups (F = 12.29, 8.11; P < 0.05). Compared with preoperative values, the changes in straylight values at 1, 4 and 10 months postoperatively were (0.12 ± 0.18), (0.19 ± 0.20), (0.08 ± 0.16) of Epi-LASIK group and (0.09 ± 0.13), (0.15 ± 0.17), (-0.01 ± 0.17) of LASIK group. In Epi-LASIK group, the preoperative refractive error, RBT/CCT, and ablation ratio have significant relevance with straylight values at 4 months postoperatively (r = -0.344, -0.361, 0.361; P < 0.05), no such correlation was found in LASIK group (r = 0.186, 0.162, -0.206; P > 0.05). For corneal haze which was found from 1 to 4 months after Epi-LASIK, grade 2, 1, 0.5 appeared in 1, 2, 4 eyes respectively and the changes of straylight values were 0.52, (0.37, 0.42), (0.06, 0.09, 0.07, 0.17) at 4 months postoperatively. 10 months postoperatively, the increases of straylight values for the eye with grade 2 haze declined from 0.52 to 0.11 after the haze disappeared. CONCLUSION: Straylight values increase significantly at early time after Epi-LASIK and LASIK, but decrease partially as time going. Corneal wound healing response may be the reasons induced the increases of light scatter after Epi-LASIK. For LASIK, flap interface factors may be the reasons. Corneal haze especially above mild grade, can affect the straylight obviously.


Assuntos
Astigmatismo/etiologia , Lasers de Excimer/efeitos adversos , Adolescente , Adulto , Feminino , Humanos , Ceratectomia Subepitelial Assistida por Laser/efeitos adversos , Ceratomileuse Assistida por Excimer Laser In Situ/efeitos adversos , Estudos Longitudinais , Masculino , Miopia/cirurgia , Período Pós-Operatório , Estudos Prospectivos , Adulto Jovem
4.
Shanghai Kou Qiang Yi Xue ; 30(4): 439-443, 2021 Aug.
Artigo em Zh | MEDLINE | ID: mdl-34693442

RESUMO

PURPOSE: To observe the occurrence of temporomandibular joint disorder (TMD) in patients with bimaxillary protrusion after orthodontic treatment, and to explore the possible factors causing this phenomenon, so as to guide rational prevention of TMD in clinic. METHODS: The clinical data of 80 patients with bimaxillary protrusion who received orthodontic treatment in Hebei Provincial People's Hospital from March 2019 to October 2020 were retrospectively analyzed. The patients with TMD after orthodontic treatment were included in the experimental group and the remaining patients were included in control group. The baseline data questionnaire was designed for bimaxillary protrusion patients after orthodontic treatment. The risk factors of TMD were included in the study. Through a series of univariate and multivariate analysis, the influencing factors of TMD in patients with bimaxillary protrusion after orthodontic treatment were determined. SPSS 23.0 software package was used to analyze the data. RESULTS: Among 80 patients with bimaxillary protrusion after orthodontic treatment, 15(18.75%) were included in the experimental group, while 65(81.25%) did not have TMD, and were included in the control group. After a preliminary analysis of the baseline data, the variables with significant difference were included in the independent variables for univariate analysis. After adjusting for the influence of other baseline data, the results showed that younger age, girl, high stress perception scale score, bad oral habits, dental caries, history of maxillofacial trauma, bad eating habits, and root canal treatment history were the causes of bimaxillary protrusion. CONCLUSIONS: The risk factors of TMD of patients with bimaxillary protrusion after orthodontic treatment may be closely related to girl, younger age, high stress perception score, bad eating habits, previous caries, root canal treatment history and maxillofacial trauma. Therefore, it is necessary to strengthen the standardization of orthodontic treatment, publicize oral health awareness, establish good eating habits. Patients who had a history of root canal therapy, maxillofacial trauma and dental caries should be vigilant, which may be of positive significance in reducing the incidence of TMD.


Assuntos
Cárie Dentária , Transtornos da Articulação Temporomandibular , Feminino , Humanos , Incidência , Estudos Retrospectivos , Fatores de Risco , Transtornos da Articulação Temporomandibular/epidemiologia
5.
Sci Rep ; 11(1): 2668, 2021 01 29.
Artigo em Inglês | MEDLINE | ID: mdl-33514798

RESUMO

Our aim was to detect type 2 innate lymphoid cells (ILC2s)-related cytokines of infants with bronchiolitis by using Elisa, Liquidchip technology and RT-PCR and investigated its correlation with bronchiolitis. We recruited 26 infants with bronchiolitis and 20 healthy infants as control from Xiangya Hospital. Compared to the control group, the serum levels of interleukin-5 (IL-5) [41.99 (21.11) vs 25.70 (19.64)], IL-9 [27.04 (37.51) vs 8.30 (0.54)], IL-13 [184.05 (132.81) vs 121.75 (176.13)], IL-33 [83.70 (46.69) vs 11.23 (55.31)] and thymic stromal lymphopoietin (TSLP) [31.42 (5.41) vs 28.76 (2.56)] were significantly increased in infants with bronchiolitis (P < 0.05), while the level of IgE had no significant difference between the two groups [19.05 (14.15) vs 14.85 (20.2), P > 0.05]. The mRNA expression of IL-17RB (9.83 ± 0.35 vs 9.19 ± 0.58), TSLP (16.98 ± 2.12 vs 15.07 ± 2.25), retinoid acid receptor related orphan receptor α (7.18 ± 0.71 vs 5.46 ± 1.09) and trans-acting T-cell-specific transcription factor 3 (4.86 ± 0.66 vs 4.19 ± 0.90) were significantly increased in infants with bronchiolitis versus the control group (P < 0.05), while there was no statistical significance for suppression of tumorigenicity 2 (5.59 ± 0.68 vs 5.41 ± 0.87, P > 0.05). Our findings suggested that ILC2s possibly play a specific role in immunopathology of bronchiolitis.


Assuntos
Bronquiolite/imunologia , Linfócitos/imunologia , Bronquiolite/genética , Bronquiolite/patologia , Pré-Escolar , Citocinas/genética , Citocinas/imunologia , Feminino , Regulação da Expressão Gênica/imunologia , Humanos , Imunoglobulina E/imunologia , Lactente , Masculino
6.
Medicine (Baltimore) ; 100(11): e25142, 2021 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-33725996

RESUMO

BACKGROUND: The hospital-acquired influenza (HAI) were usually contributed to severe outcomes among the inpatients. Here, we performed a meta-analysis to summarize and quantify the epidemiological and clinical characteristics of HAI. METHODS: We performed a literature search thorough PubMed, Web of Science, Cochrane Library, Embase, Scopus and China National Knowledge Infrastructure (CNKI), and Wanfang databases for observational studies. Random/fix-effects models were used to obtain pooled proportion, odds ratio (OR), and weighted mean difference (WMD). RESULTS: A total of 14 studies involving 1483 HAI and 71849 non-hospital-acquired influenza infections (NHAI) cases were included.The proportion of the HAI among the influenza cases was 11.38% (95% confidence interval [CI]: 5.19%-19.55%) and it was increased after 2012 (6.15% vs 12.72%). The HAI cases were significantly older (WMD = 9.51, 95% CI: 0.04-18.98) and the patients with chronic medical diseases were at increased risk of HAI (OR = 1.85, 95% CI: 1.57-2.19). Among them, metabolic disorders (OR = 8.10, 95% CI: 2.46-26.64) ranked the highest danger, followed by malignancy (OR = 3.18, 95% CI: 2.12-4.76), any chronic diseases (OR = 2.81, 95% CI: 1.08-9.31), immunosuppression (OR = 2.13, 95% CI: 1.25-3.64), renal diseases (OR = 1.72, 95% CI:1.40-2.10), heart diseases (OR = 1.52, 95% CI: 1.03-1.44), and diabetes (OR = 1.22, 95% CI: 1.03-1.44). The HAI cases were more likely to experience longer hospital stay (WMD = 10.23, 95% CI: 4.60-15.85) and longer intensive care unit (ICU) stay (WMD = 2.99, 95% CI: 1.50-4.48). In the outcomes within 30 days, those population was still more likely to receive hospitalization (OR = 6.55, 95% CI: 5.19-8.27), death in hospital (OR = 1.99, 95% CI: 1.65-2.40) but less likely to discharged (OR = 0.20, 95% CI: 0.16-0.24). CONCLUSION: The proportion of the HAI among the influenza cases was relatively high. Reinforcement of the surveillance systems and vaccination of the high-risk patients and their contacts are necessary for the HAI control.


Assuntos
Infecção Hospitalar/epidemiologia , Hospitalização/estatística & dados numéricos , Vírus da Influenza A , Influenza Humana/epidemiologia , Vigilância da População , Estudos de Casos e Controles , Infecção Hospitalar/virologia , Estudos Transversais , Feminino , Humanos , Incidência , Influenza Humana/etiologia , Masculino , Razão de Chances
7.
J Ovarian Res ; 13(1): 76, 2020 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-32622365

RESUMO

BACKGROUND: Ovarian cancer is one of the most common malignant tumors in the female reproductive system with the highest mortality rate. Cul4B participates in the oncogenesis and progression of several malignant tumors. However, the role of Cul4B in ovarian cancer has not been studied. RESULTS: High expression of intratumor Cul4B was associated with poor patient survival. Cul4B expression was associated with FIGO stage and Cul4B was independent risk factor of ovarian cancer disease-free survival and overall survival. In vitro studies revealed that overexpression of Cul4B promoted tumor proliferation while knockdown of Cul4B significantly inhibited the proliferation capacity of ovarian cancer cells. Mechanistically, Cul4B was found to promotes cell entering S phase from G0/G1 phase by regulating the expression of CDK2 and CyclinD1. Cul4B regulates the expression of CDK2 and CyclinD1 by repressing miR-372. CONCLUSIONS: The results revealed that high expression of Cul4B is associated with poor ovarian cancer prognosis and Cul4B may serve as a potential treating target for an adjuvant therapy.


Assuntos
Proteínas Culina/genética , Ciclina D1/genética , Quinase 2 Dependente de Ciclina/genética , Neoplasias Ovarianas/genética , Regulação para Cima/genética , Ciclo Celular/genética , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Progressão da Doença , Feminino , Regulação Neoplásica da Expressão Gênica/genética , Humanos , MicroRNAs/genética , Pessoa de Meia-Idade , Neoplasias Ovarianas/patologia , Fatores de Risco
8.
Transl Cancer Res ; 9(2): 657-668, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35117411

RESUMO

BACKGROUND: The resistance to endocrine therapy poses a significant challenge to the management of advanced breast cancer with hormone receptor (HR) positive and human epidermal growth factor receptor 2 (Her-2) negative. The purpose of this study was to further examine the efficacy and safety of cyclin-dependent kinase 4/6 inhibitors (CDK4/6Is) in combination with endocrine therapy as a recovery treatment for advanced breast cancer patients. METHODS: The risk of bias for each included study was assessed using the Cochrane Risk of Bias Tool. The Cochrane Q value, combined with the I2 statistics, were selected to be tested for heterogeneity across the studies. The generic inverse variance was used to pool the hazard ratio and 95% CI of progression-free survival (PFS) and overall survival (OS), while pooled RRs and 95% CI were conducted using the Mantel-Haenszel to appraise the overall response rate (ORR), clinical benefit rate (CBR), and any adverse effects. RESULTS: Eight random clinical trials were finally identified. The analysis showed that the duration of PFS was significantly longer in the CDK4/6Is group than in the control group (hazard ratio, 0.55; 95% CI, 0.51-0.60; P<0.00001), and treatment with CDK4/6Is-endocrine therapy resulted in longer OS than treatment with endocrine therapy only (hazard ratio, 0.79; 95% CI, 0.66-0.96; P=0.001). As for any adverse events, the analysis showed a remarkable rise in bone marrow suppression, especially neutropenia and leukopenia (respectively, RR =32.04; 95% CI, 17.14-59.90, RR =30.65; 95% CI, 16.51-56.91), but not in gastrointestinal toxicity. CONCLUSIONS: Highly selective CDK4/6Is were well tolerated, effective drugs in advanced breast cancer patients with HR-positive and Her-2 negative.

9.
Cancer Manag Res ; 12: 12011-12020, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33262651

RESUMO

PURPOSE: To explore the regulatory mechanism of long non-coding RNA small nucleolar RNA host gene 1 (SNHG1) in glioma. MATERIALS AND METHODS: The expression of SNHG1 and miR-140-5p in glioma tissues and glioma cell lines (LN-18, KNS-81, and KALS-1) was determined, and the effect of the two on cell proliferation, invasion, and PI3K/AKT pathway was analyzed. RESULTS: SNHG1 was overexpressed in glioma tissues, while miR-140-5p was underexpressed in them, and there was a significant negative correlation between SNHG1 and miR-140-5p. In addition, both down-regulation of SNHG1 and up-regulation of miR-140-5p significantly inhibited the malignant proliferation and invasion of glioma, intensified the apoptosis, and also significantly suppressed the activation of the PI3K/AKT pathway. The dual-luciferase reporter assay, RNA pull-down assay, and RIP determination all confirmed that there was a targeting relationship between SNHG1 and miR-140-5p, and there was no difference between KNS-81 and KALS-1 cells transfected with SNHG1+mimics and si-SNHG1+inhibitor and those in the si-NC group with unrelated sequences in terms of cell malignant progression. CONCLUSION: SNHG1/miR-140-5p axis and its regulation on PI3K/AKT pathway might be a novel therapeutic direction to curb the malignant progression of glioma.

10.
Shanghai Kou Qiang Yi Xue ; 28(5): 504-508, 2019 Oct.
Artigo em Zh | MEDLINE | ID: mdl-32274482

RESUMO

PURPOSE: To investigate the effects of basic periodontal treatment on the levels of endothelin (ET), vascular endothelial growth factor-A (VEGF-A) and tumor necrosis factor-α (TNF-α) in gingival crevicular fluid and serum. METHODS: A total of 57 patients with periodontitis (experimental group) and 43 healthy examinees (control group) admitted to Shenzhen Hospital of Guangzhou University of Chinese Medicine from October to May 2018 were selected. Patients received subgingival scaling and root planing for 6 weeks. Then various indexes were compared, including bleeding on probing (BOP), plaque index (PI), probe depth (PD), clinical attachment level (CAL) and gingival index (GI), as well as the levels of ET, VEGF-A and TNF-α in gingival crevicular fluid and serum. The correlation between ET, VEGF-A and TNF-α was analyzed. The data were analyzed with SPSS 21.0 software package. RESULTS: Periodontal indexes including BOP, PI, PD, CAL and GI in the experimental group were significantly increased after treatment (P<0.05), but still significantly lower than those in the control group (P<0.05). The levels of ET, VEGF-A and TNF-α in gingival crevicular fluid and serum were significantly decreased in the experimental group after treatment (P<0.05), but significantly higher than those in the control group (P<0.05). The level of ET in gingival crevicular fluid was not significantly correlated with VEGF-A level in patients with periodontitis (P>0.05), while was positively correlated with VEGF-A levels (P<0.05). CONCLUSIONS: Basic periodontal treatment can reduce the levels of ET, VEGF-A and TNF-α in gingival crevicular fluid and serum of patients with periodontitis, and improve the periodontal status; moreover, ET level in gingival crevicular fluid is positively correlated with TNF-α level.


Assuntos
Periodontite Crônica , Líquido do Sulco Gengival , Índice de Placa Dentária , Raspagem Dentária , Endotelinas , Humanos , Perda da Inserção Periodontal , Fator de Necrose Tumoral alfa , Fator A de Crescimento do Endotélio Vascular
11.
Leuk Lymphoma ; 57(6): 1311-8, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26372888

RESUMO

Decitabine (DAC) is commonly used for the treatment of myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). Previous studies have indicated DAC sequentially combined with idarubicin was an effective treatment for myeloid neoplasms. Therefore, a clinical study was conducted of the sequential combination of DAC followed by low-dose idarubicin/cytarabine in high-risk myeloid neoplasms. A total of 30 patients with a diagnosis of high-risk MDS, AML evolving from MDS or relapsed/refractory AML were enrolled in the study. DAC was administered 20 mg/m(2) daily for 3 consecutive days. Idarubicin (3 mg/m(2)/day) was administered 24 h after the last administration of DAC for 5-7 consecutive days, combined with cytarabine (30 mg/m(2)/day) for 7-14 days. The overall complete remission rate was 66.67%. The results demonstrate that epigenetic priming with decitabine followed by low-dose idarubicin/ytarabine has an increased anti-leukemia effect compared to traditional chemotherapy in high-risk myeloid neoplasms.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Azacitidina/análogos & derivados , Epigênese Genética/efeitos dos fármacos , Leucemia Mieloide Aguda/tratamento farmacológico , Leucemia Mieloide Aguda/genética , Síndromes Mielodisplásicas/tratamento farmacológico , Síndromes Mielodisplásicas/genética , Adulto , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Azacitidina/administração & dosagem , Azacitidina/uso terapêutico , Aberrações Cromossômicas , Citarabina/administração & dosagem , Decitabina , Progressão da Doença , Esquema de Medicação , Resistencia a Medicamentos Antineoplásicos , Feminino , Humanos , Idarubicina/administração & dosagem , Leucemia Mieloide Aguda/diagnóstico , Masculino , Pessoa de Meia-Idade , Mutação , Síndromes Mielodisplásicas/diagnóstico , Recidiva , Indução de Remissão , Resultado do Tratamento
12.
Chem Asian J ; 10(3): 614-21, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25641859

RESUMO

Ferrocenylethynyl-terminated derivatives 8-12 have been synthesized and characterized by electrochemistry and UV/Vis spectroscopy. The electrochemical and photophysical studies indicate that the electronic communication in ferrocenylethynyl-substituted derivatives is strongly influenced by the substituted position of the ferrocenylethynyl moiety. In situ electrochemical oxidation or chemical oxidation caused a characteristically weak ligand-to-metal charge-transfer (LMCT) band to appear at 700-1000 nm. Subsequent electrochemical reduction or chemical reduction recovered the most of the original curve and the color of the solution as well. Among the derivatives, compound 8 exhibits the highest cis/trans molar ratio (64:36) in the photostationary state (PSS) upon light irradiation at 365 nm. Compound 8 exhibits excellent fatigue resistance and reversibility under several repeated reversible isomerization cycles.

13.
Dalton Trans ; 41(36): 11000-8, 2012 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-22858784

RESUMO

Two novel alkynyl-bridged symmetric bis-tridentate ligands 1,2-bis(1'-[4'-(2,2':6',2''-terpyridinyl)]ferrocenyl)ethyne (3a; tpy-Fc-C[triple bond]C-Fc-tpy; Fc = ferrocenyl; tpy = terpyridyl) and 1,4-bis(1'-[4'-(2,2':6',2''-terpyridinyl)]ferrocenyl)-1,3-butadiyne (3b; tpy-Fc-C[triple bond]C-C[triple bond]C-Fc-tpy) and their Ru(2+) complexes 6a and 6b have been synthesized and characterized by cyclic voltammetry, UV-vis and luminescence spectroscopy, and in the case of 3b by single-crystal X-ray diffraction. Cyclic voltammograms of both compounds, 3a and 3b, display two severely overlapping ferrocene-based oxidative peaks with only one reductive peak. The redox behavior of 6a and 6b is dominated by the Ru(2+)/Ru(3+) redox couple (E(1/2) from 1.33 to 1.34 V), the Fe(2+)/Fe(3+) redox couples (E(1/2) from 0.46 to 0.80 V), and the tpy/tpy(-)/tpy(2-) redox couples (E(1/2) from -1.19 to -1.48 V). The UV-vis spectra of 6a and 6b show absorption bands assigned to the (1)[(d(π)(Fe))(6)] → (1)[(d(π)(Fe))(5)(π*(tpy)(Ru))(1)] MMLCT transition at ~555 nm. Complexes and are luminescent in H(2)O-CH(3)CN (4 : 1, v/v) solution at room temperature, and 6b exhibits the strongest luminescence intensity (λ(max)(em): 710 nm, Φ(em): 2.28 × 10(-4), τ: 358 ns) relative to analogous ferrocene-based bis(terpyridine) Ru(II) complexes reported so far.

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