1,773 research outputs found

    Photochemical studies of cis-[Ru(bpy)2(4-bzpy)(CO)](PF6)2 and cis-[Ru(bpy)2(4-bzpy)(Cl)](PF6): Blue light-induced nucleobase binding.

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    The ruthenium(II) compounds cis-[Ru(bpy)2(4-bzpy)(CO)](PF6)2 (I) and cis-[Ru(bpy)2(4-bzpy)(Cl)](PF6) (II) (4-bzpy=4-benzoylpyridine, bpy=2,2'-bipyridine) were synthesized and characterized by spectroscopic and electrochemical techniques. The crystal structure of II was determined by X-ray diffraction. The photochemical behavior of I in aqueous solution shows that irradiation with ultraviolet light (365nm) releases both CO and 4-bzpy leading to the formation of the cis-[Ru(bpy)2(H2O)2]2+ ion as identified by NMR and electronic spectroscopy. Carbon monoxide release was confirmed with the myoglobin method and by gas chromatographic analysis of the headspace. CO release was not observed when aqueous I was irradiated with blue light (453nm). Changes in the electronic and 1H NMR spectra indicate that I undergoes photoaquation of 4-bzpy to form cis-[Ru(bpy)2(CO)(H2O)]2+. Blue light irradiation of aqueous II released the coordinated 4-bzpy to give the cis-[Ru(bpy)2(H2O)(Cl)]2+ ion. When the latter reaction was carried out in the presence of the nucleobase guanine, Ru-guanine adducts were formed, indicating that the metal containing photoproduct may also participate in biologically relevant reactions. The photochemical behavior of I indicates that it can release either CO or 4-bzpy depending on the wavelength chosen, a feature that may have therapeutic application

    Avaliação e tratamento do doente com acne – Parte I: Epidemiologia, etiopatogenia, clínica, classificação, impacto psicossocial, mitos e realidades, diagnóstico diferencial e estudos complementares

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    O Portuguese Acne Advisory Board (PAAB), grupo de dermatologistas portugueses que, à semelhança de grupos congéneres internacionais, tem dedicado particular atenção à definição de linhas de orientação para o tratamento da acne, pretende que o presente documento constitua uma ferramenta útil na abordagem dos doentes com esta patologia. Elaborou-se um dossier, para educação médica contínua, subdividido em 2 partes: Parte I – etiopatogenia e clínica; Parte II – abordagem terapêutica. Nesta Parte I, revêem-se os principais aspectos da clínica e da fisiopatogenia da acne à luz dos conhecimentos actuais. Discute-se a importância do impacto psicológico e social desta entidade e analisam-se os principais mitos e realidades com ela relacionados. Descrevem-se, sucintamente, as patologias mais relevantes no diagnóstico diferencial das lesões de acne. Enumeram-se as indicações para estudo hormonal, bem como os exames a efectuar nos doentes com esta patologia. The Portuguese Acne Advisory Board (PAAB), a group of Portuguese dermatologists with a special interest in acne, develop, as other international groups in this field, consensus recommendations for the treatment of acne. Overall, the goal is to provide a practice guideline to all physicians dealing with this entity. The continuing medical education dossier was divided in two parts: Part I – etiopathogeny and clinical features; Part II – therapy. This Part I reviews acne pathophysiology, clinical aspects, psychological and social impact and several myths surrounding this disease. Some other entities relevant for the differential diagnosis are described. The need of hormonal evaluation is also discusse

    Avaliação e tratamento do doente com acne - Parte II: tratamento tópico, sistémico e cirúrgico, tratamento da acne na grávida, algoritmo terapêutico

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    O Portuguese Acne Advisory Board (PAAB), grupo de dermatologistas portugueses que, à semelhança de grupos congéneres internacionais, tem dedicado particular atenção à definição de linhas de orientação para o tratamento da acne, pretende que o presente documento constitua uma ferramenta útil na abordagem dos doentes com esta patologia. Elaborou-se um dossier, para educação médica contínua, subdividido em 2 partes: Parte I – etiopatogenia e clínica; Parte II – abordagem terapêutica. Nesta Parte II discute-se a abordagem terapêutica – tópica e sistémica – em cada forma clínica de acne, dando particular ênfase aos retinóides e aos antimicrobianos, e salientam-se as estratégias a adoptar para limitar a crescente resistência bacteriana aos antibióticos. Referem-se as indicações específicas para terapêutica hormonal e analisam-se as particularidades do tratamento da acne na grávida e lactante. Descrevem-se algumas técnicas para correcção das cicatrizes da acne. Por último, publica-se um algoritmo que pretende ilustrar a classificação da acne e definir, para cada tipo clínico, a abordagem terapêutica consensualmente recomendada

    Heterotic Black Horizons

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    We show that the supersymmetric near horizon geometry of heterotic black holes is either an AdS_3 fibration over a 7-dimensional manifold which admits a G_2 structure compatible with a connection with skew-symmetric torsion, or it is a product R^{1,1} * S^8, where S^8 is a holonomy Spin(7) manifold, preserving 2 and 1 supersymmetries respectively. Moreover, we demonstrate that the AdS_3 class of heterotic horizons can preserve 4, 6 and 8 supersymmetries provided that the geometry of the base space is further restricted. Similarly R^{1,1} * S^8 horizons with extended supersymmetry are products of R^{1,1} with special holonomy manifolds. We have also found that the heterotic horizons with 8 supersymmetries are locally isometric to AdS_3 * S^3 * T^4, AdS_3 * S^3 * K_3 or R^{1,1} * T^4 * K_3, where the radii of AdS_3 and S^3 are equal and the dilaton is constant.Comment: 35 pages, latex. Minor alterations to equation (3.11) and section 4.1, the conclusions are not affecte

    Advanced intrahepatic cholangiocarcinoma: post-hoc analysis of the ABC-01, -02 and -03 clinical trials

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    Background The incidence of intrahepatic cholangiocarcinoma (iCCA) is increasing. The aim was to provide reference survival data for patients with advanced iCCA treated with first-line cisplatin-gemcitabine chemotherapy (current standard of care). Methods Individual data from patients with iCCA recruited into the prospective, randomised Advanced Biliary tract Cancer (ABC)-01, -02 and -03 studies were retrieved. The prevalence and survival of liver-only iCCA was also assessed. Survival analysis was performed using univariate and multivariable Cox Regression. All statistical tests were two-sided. Results Of 534 patients recruited into the ABC-01, -02 and -03 studies, 109 (20.4%) had iCCA. Most patients (n = 86; 78.9%) had metastatic disease at the time of recruitment; 52 patients (47.7%) had liver-only disease. Following randomisation, 66 (60.6%) iCCA patients received cisplatin/gemcitabine. The median progression-free (PFS) and overall survival (OS) was 8.4 months (95%confdence interval [CI] = 5.9-8.9) and 15.4 months (95%CI = 11.1-17.9), respectively. Of these 66 patients, 34 patients (51.5%) had liver-only disease. Following chemotherapy, 30 (45.5%) and 21 (31.8%) were progression free at 3 and 6 months from chemotherapy commencement, respectively. Median OS for patients with liver-only iCCA at diagnosis, and after 3 and 6 months of chemotherapy was 16.7 months (95% confidence interval [CI] = 8.7-20.2), 17.9 (95%CI = 11.7-20.9) and 18.9 (95%CI = 16.7-25.9) months, respectively. Multivariable analysis confirmed that iCCA had a longer OS compared to other non-iCCA BTCs (hazard ratio = 0.58, 95%CI = 0.35-0.95; p-value = 0.03); liver-only iCCA patients also showed longer OS even though findings did not reach statistical significance (hazard ratio = 0.65, 95%CI = 0.36-1.19; p-value = 0.16). Conclusions Patients diagnosed with advanced iCCA have a better OS compared to other BTCs; similar trend was identified for patients diagnosed with liver-only iCCA. These findings are to be considered for future clinical trial design
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