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1.
Public Health Rev ; 43: 1604796, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36120091

RESUMO

Objective: Identify barriers and facilitators in access to medicines for diabetes, hypertension, and dyslipidemia, considering patient, health provider, and health system perspectives. Methods: Scoping review based on Joanna Briggs methodology. The search considered PubMed, Cochrane Library, CINAHL, Academic Search Ultimate, Web of Science, SciELO Citation Index, and grey literature. Two researchers conducted screening and eligibility phases. Data were thematically analyzed. Results: The review included 219 documents. Diabetes was the most studied condition; most of the evidence comes from patients and the United States. Affordability and availability of medicines were the most reported dimension and specific barrier respectively, both cross-cutting concerns. Among high- and middle-income countries, identified barriers were cost of medicines, accompaniment by professionals, long distances to facilities, and cultural aspects; cost of transportation emerges in low-income settings. Facilitators reported were financial accessibility, trained health workers, medicines closer to communities, and patients' education. Conclusion: Barriers and facilitators are determined by socioeconomic and cultural conditions, highlighting the role of health systems in regulatory and policy context (assuring financial coverage and free medicines); providers' role bringing medicines closer; and patients' health education and disease management.

2.
Transp Res Part A Policy Pract ; 161: 107-129, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35572809

RESUMO

The lockdown of March and April 2020 declared by Spanish authorities in the Valencian Region to bending the Covid-19 curve, caused a drastic reduction of the economic activity and a severe limitation of mobility. People were asked to stay at home as much as possible. Education and administrative centers, as well as restaurants, theaters, sport arenas, etc., were closed. Work at conventional workplaces was prohibited for people who could tele-work, and students were compelled to attend classes on-line. Such limitation of mobility and spending so many time at home, could affect the wellbeing of people. The objective of the present paper is to present a study on the differences on wellbeing according to the mobility of respondents during the lockdown. Information from 1,827 individuals regarding the satisfaction of the basic psychological needs (Autonomy, Competence and Relatedness) and Positive and Negative affect were collected through and web-survey during the first lockdown of the Covid-19 pandemic, together with mobility data and sociodemographic characteristics. Mann-Whitney U tests, Confirmatory Factor Analyses and Structural Equation models are used to find out differences in the wellbeing of people according to their mobility characteristics during the first lockdown, and how these mobility characteristics are associated to the psychological variables studied. Mobility of people during the first lockdown reduced drastically, especially the youngest ones, and the main travel mode was walking. In general, the youngest participants in this research and females present lower values of the psychological wellbeing variables during the lockdown. A very low or very high degree of mobility is also associated to discomfort, although the more time spent traveling the better people feel. Those who walked more are related to lower values of wellbeing. Some lessons are learned to improve transport and mobility planning during a pandemic.

3.
ACS Sens ; 6(10): 3632-3639, 2021 10 22.
Artigo em Inglês | MEDLINE | ID: mdl-34498459

RESUMO

Unraveling cellular physiological processes via luminescent probes that target specific cellular microenvironments is quite challenging due to the uneven distribution of probes. Herein, we designed a new dynamic excimer (DYNEX) imaging method that involves the sensitive detection of nanosecond-scale dynamic molecular contacts of a fluorescent acridone derivative and reveals the cell microenvironment polarity. Using our method, we specifically tracked cell lipid droplets in fibroblast colon carcinoma cells. These organelles play a central role in metabolic pathways, acting as energy reservoirs in regulatory processes. DYNEX imaging provides the inner polarity of cell lipid droplets, which can be related to lipid contents and metabolic dysfunctions. This new methodology will inspire development of novel multidimensional fluorescent sensors that are able to provide target-specific and orthogonal information at the nanosecond scale.


Assuntos
Corantes Fluorescentes , Gotículas Lipídicas , Microscopia de Fluorescência , Imagem Óptica
4.
Entropy (Basel) ; 22(12)2020 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-33322747

RESUMO

Positional obstructive sleep apnea (POSA) is a major phenotype of sleep apnea. Supine-predominant positional patients are frequently characterized by milder symptoms and less comorbidity due to a lower age, body mass index, and overall apnea-hypopnea index. However, the bradycardia-tachycardia pattern during apneic events is known to be more severe in the supine position, which could affect the cardiac regulation of positional patients. This study aims at characterizing nocturnal heart rate modulation in the presence of POSA in order to assess potential differences between positional and non-positional patients. Patients showing clinical symptoms of suffering from a sleep-related breathing disorder performed unsupervised portable polysomnography (PSG) and simultaneous nocturnal pulse oximetry (NPO) at home. Positional patients were identified according to the Amsterdam POSA classification (APOC) criteria. Pulse rate variability (PRV) recordings from the NPO readings were used to assess overnight cardiac modulation. Conventional cardiac indexes in the time and frequency domains were computed. Additionally, multiscale entropy (MSE) was used to investigate the nonlinear dynamics of the PRV recordings in POSA and non-POSA patients. A total of 129 patients (median age 56.0, interquartile range (IQR) 44.8-63.0 years, median body mass index (BMI) 27.7, IQR 26.0-31.3 kg/m2) were classified as POSA (37 APOC I, 77 APOC II, and 15 APOC III), while 104 subjects (median age 57.5, IQR 49.0-67.0 years, median BMI 29.8, IQR 26.6-34.7 kg/m2) comprised the non-POSA group. Overnight PRV recordings from positional patients showed significantly higher disorderliness than non-positional subjects in the smallest biological scales of the MSE profile (τ = 1: 0.25, IQR 0.20-0.31 vs. 0.22, IQR 0.18-0.27, p < 0.01) (τ = 2: 0.41, IQR 0.34-0.48 vs. 0.37, IQR 0.29-0.42, p < 0.01). According to our findings, nocturnal heart rate regulation is severely affected in POSA patients, suggesting increased cardiac imbalance due to predominant positional apneas.

7.
Medicine (Baltimore) ; 99(17): e19769, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32332617

RESUMO

INTRODUCTION: High blood pressure is the leading modifiable risk factor for cardiovascular disease, and is associated with high morbidity and mortality and with significant health care costs for individuals and society. However, fewer than half of the patients with hypertension receiving pharmacological treatment have adequate blood pressure control. The main reasons for this are therapeutic inertia, lack of adherence to treatment, and unhealthy lifestyle (i.e., excess dietary fat and salt, sedentary lifestyle, and overweight). Cardiovascular risk and mortality are greater in hypertensive patients who are receiving treatment but have suboptimal control of blood pressure. METHODS/DESIGN: This is a multicentre, parallel, 2-arm, single-blind (outcome assessor), controled, cluster-randomized clinical trial. General practitioners and nurses will be randomly allocated to the intervention group (self-management of antihypertensive medication, self-measurement of blood pressure, hypocaloric and low sodium diet, and physical exercise) or the control group (regular clinical practice). A total of 424 patients in primary care centers who use 2 or more antihypertensive drugs and blood pressure of at least 130/80 during 24-hambulatory blood pressure monitoring will be recruited. The primary outcome is systolic blood pressure at 12 months. The secondary outcomes are blood pressure control (<140/90 mm Hg); quality of life (EuroQol 5D); direct health care costs; adherence to use of antihypertensive medication; and cardiovascular risk (REGICOR and SCORE scales). DISCUSSION: This trial will be conducted in the primary care setting and will evaluate the impact of a multifactorial intervention consisting of self-management of blood pressure, antihypertensive medications, and lifestyle modifications (hypocaloric and low sodium diet and physical exercise).


Assuntos
Anti-Hipertensivos/normas , Determinação da Pressão Arterial/normas , Hipertensão/tratamento farmacológico , Adulto , Idoso , Anti-Hipertensivos/uso terapêutico , Pressão Sanguínea/efeitos dos fármacos , Determinação da Pressão Arterial/métodos , Restrição Calórica/métodos , Análise por Conglomerados , Dieta Hipossódica/métodos , Exercício Físico/fisiologia , Feminino , Humanos , Hipertensão/psicologia , Estilo de Vida , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Autogestão/métodos , Autogestão/psicologia , Cooperação e Adesão ao Tratamento/psicologia , Resultado do Tratamento
8.
Sci Rep ; 10(1): 5332, 2020 03 24.
Artigo em Inglês | MEDLINE | ID: mdl-32210294

RESUMO

The most appropriate physiological signals to develop simplified as well as accurate screening tests for obstructive sleep apnoea (OSA) remain unknown. This study aimed at assessing whether joint analysis of at-home oximetry and airflow recordings by means of machine-learning algorithms leads to a significant diagnostic performance increase compared to single-channel approaches. Consecutive patients showing moderate-to-high clinical suspicion of OSA were involved. The apnoea-hypopnoea index (AHI) from unsupervised polysomnography was the gold standard. Oximetry and airflow from at-home polysomnography were parameterised by means of 38 time, frequency, and non-linear variables. Complementarity between both signals was exhaustively inspected via automated feature selection. Regression support vector machines were used to estimate the AHI from single-channel and dual-channel approaches. A total of 239 patients successfully completed at-home polysomnography. The optimum joint model reached 0.93 (95%CI 0.90-0.95) intra-class correlation coefficient between estimated and actual AHI. Overall performance of the dual-channel approach (kappa: 0.71; 4-class accuracy: 81.3%) significantly outperformed individual oximetry (kappa: 0.61; 4-class accuracy: 75.0%) and airflow (kappa: 0.42; 4-class accuracy: 61.5%). According to our findings, oximetry alone was able to reach notably high accuracy, particularly to confirm severe cases of the disease. Nevertheless, oximetry and airflow showed high complementarity leading to a remarkable performance increase compared to single-channel approaches. Consequently, their joint analysis via machine learning enables accurate abbreviated screening of OSA at home.


Assuntos
Monitorização Ambulatorial/métodos , Ventilação Pulmonar/fisiologia , Síndromes da Apneia do Sono/diagnóstico , Adulto , Idoso , Algoritmos , Feminino , Humanos , Aprendizado de Máquina , Masculino , Programas de Rastreamento/métodos , Pessoa de Meia-Idade , Oximetria/métodos , Polissonografia/métodos , Reprodutibilidade dos Testes , Fenômenos Fisiológicos Respiratórios , Síndromes da Apneia do Sono/fisiopatologia , Apneia Obstrutiva do Sono/diagnóstico , Apneia Obstrutiva do Sono/fisiopatologia , Espanha/epidemiologia
9.
Chemistry ; 26(15): 3373-3384, 2020 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-31967698

RESUMO

This work is focused on unraveling the mechanisms responsible for the aggregation-induced enhanced emission and solid-state luminescence enhancement effects observed in star-shaped molecules based on 1,3,5-tris(styryl)benzene and tri(styryl)-s-triazine cores. To achieve this, the photophysical properties of this set of molecules were analyzed in three states: free molecules, molecular aggregates in solution, and the solid state. Different spectroscopy and microscopy experiments and DFT calculations were conducted to scrutinize the causative mechanisms of the luminescence enhancement phenomenon observed in some experimental conditions. Enhanced luminescence emission was interpreted in the context of short- and long-range excitonic coupling mechanisms and the restriction of intramolecular vibrations. Additionally, we found that the formation of π-stacking aggregates could block E/Z photoisomerization through torsional motions between phenylene rings in the excited state, and hence, enhancing the luminescence of the system.

10.
Medisur ; 17(2): 241-247, mar.-abr. 2019. tab
Artigo em Espanhol | LILACS-Express | LILACS | ID: biblio-1002672

RESUMO

RESUMEN Fundamento: El afrontamiento de la maternidad en la adolescencia tiene serias implicaciones para la vida de la madre y su descendencia. Es un proceso en el que influyen diversos factores sociales, culturales, económicos y biológicos. Objetivo: describir la relación entre factores socioculturales y la decisión del tipo de parto en adolescentes ecuatorianas. Métodos: estudio descriptivo, de corte transversal. Se estudiaron 574 adolescentes de la ciudad de Machala, Ecuador, en el año 2016, aplicando una encuesta personal. Se estableció en este grupo de adolescentes la relación entre la decisión del tipo de parto con las variables edad, residencia, paridad, religión e instrucción; y se definió la asociación estadística derivada de estas relaciones. Resultados: la mayor preferencia fue hacia el parto transpelviano, con un 82,4 %. El 70,2 % de las féminas perteneció a áreas urbanas, y el 66,2 % de ellas no tenía partos previos. La mayoría de las jóvenes decidió tener un parto transpelviano, a pesar del razonamiento expuesto referente a diferentes factores socioculturales. Hubo relación estadística significativa entre el razonamiento y la decisión. Conclusión: los aspectos socioculturales abordados no influyen en la toma de la decisión del tipo de parto que desean las adolescentes ecuatorianas; más bien, su decisión puede orientar hacia problemas de otra índole. Solo las creencias religiosas y el razonamiento que sirvió de base a la elección, se manifestaron como factores influyentes.


ABSTRACT Foundation: Confronting motherhood in adolescence has serious implications for the life of the mother and her descendant. It is a process influenced by various social, cultural, economic and biological factors. Objective: to describe the relationship between sociocultural factors and the decision of the type of delivery in Ecuadorian adolescents. Methods: cross- descriptive, study. A number of 574 adolescents were studied from the city of Machala, Ecuador, in 2016, applying a personal survey. The relationship between the decision of the type of delivery with the variables age, residence, parity, religion and instruction was established in this group of adolescents; and the statistical association derived from these relationships was defined. Results: the greater preference was towards trans-pelvic childbirth, with 82.4%. 70.2% of the adolescents belonged to urban areas, and 66.2% of them did not have previous births. The majority of them decided to have a trans-pelvic childbirth, despite the reasoning given regarding different sociocultural factors. There was a significant statistical relationship between the reasoning and the decision. Conclusion: the sociocultural aspects addressed do not influence the decision of the desired type of delivery; rather, their decision may lead to problems of another kind. Only religious beliefs and reasoning that served as the basis for the election were manifested as influential factors.

11.
J Expo Sci Environ Epidemiol ; 29(2): 278-291, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30185946

RESUMO

Air pollution is one of the greatest challenges cities are facing today and improving air quality is a pressing need to reduce negative health impacts. In order to efficiently evaluate which are the most appropriate policies to reduce the impact of urban pollution sources (such as road traffic), it is essential to conduct rigorous population exposure assessments. One of the main limitations associated with those studies is the lack of information about population distribution in the city along the day (population dynamics). The pervasive use of mobile devices in our daily lives opens new opportunities to gather large amounts of anonymized and passively collected geolocation data allowing the analysis of population activity and mobility patterns. This study presents a novel methodology to estimate population dynamics from mobile phone data based on a user-centric mobility model approach. The methodology was tested in the city of Madrid (Spain) to evaluate population exposure to NO2. A comparison with traditional census-based methods shows relevant discrepancies at disaggregated levels and highlights the need to incorporate mobility patterns into population exposure assessments.


Assuntos
Poluentes Atmosféricos/análise , Poluição do Ar/análise , Telefone Celular , Exposição Ambiental/análise , Monitoramento Ambiental/métodos , Dinâmica Populacional , Cidades , Humanos , Espanha
12.
Psicol. educ. (Madr.) ; 23(1): 63-72, jun. 2017. tab
Artigo em Espanhol | IBECS | ID: ibc-162962

RESUMO

El objetivo del estudio fue analizar la autoeficacia para el aprendizaje de la investigación que tienen los estudiantes universitarios y de qué manera estas ideas interactúan con sus concepciones respecto a la investigación. La muestra la constituyen 1.304 estudiantes de la Universidad Técnica de Machala, Ecuador, a los cuales se les aplicó un inventario de autoeficacia para el aprendizaje de la investigación. Los resultados indican que las ideas de autoeficacia están en proceso de formación. El estudiante ve la investigación como requisito para continuar su progresión profesional, de allí que se concibe más como producto que como proceso. Hay un relativo interés y autoconfianza para investigar. Se determinó que las ideas de eficacia de modo lineal no cambian las nociones de investigación que tienen los estudiantes y que los imaginarios de la universidad condicionan la fuerza y dirección de las creencias personales en la capacidad de aprender a investigar


The aim of this study was to analyze the university students' self-efficacy for learning how to conduct research and how these ideas interact with their conceptions about research. The sample was made up of 1,304 students from Universidad Técnica de Machala, Ecuador. A questionnaire about self-efficacy for learning how to conduct research was applied to these students. The results of this study show that the ideas of self-efficacy are being formed. Students see research as a requirement for continuing their professional career; therefore, it is from that idea that research is conceived more as product than as a process. There exists a relative interest and confidence in conducting research. As a result, it has been determined that ideas of efficacy in the linear model do not change the research notions that university students have. It was also found that university social representations determine the strength and direction of personal beliefs in the ability to learn how to conduct research


Assuntos
Humanos , Autoeficácia , Pesquisa/educação , Aprendizagem , Estudantes/estatística & dados numéricos , Universidades , Confiança/psicologia , Teoria da Construção Pessoal
13.
Dalton Trans ; 45(44): 17896-17909, 2016 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-27775738

RESUMO

2,4-Bis(1,3,7-trimethyl-pteridine-2,4(1H,3H)-dione-6-yl)-2,3-dihydro-2-methyl-1H-1,5-benzodiazepine (DLMBZD) has been prepared and its molecular and crystal structures have been determined from spectral and XRD data. The benzodiazepine ligand was reacted with zinc(ii), cadmium(ii) and mercury(ii) chloride, bromide and iodide to give complexes with general formula [M(DLMBZD)X2]. The complexes have been synthesized and characterized by IR, NMR and elemental analysis. The structure of seven complexes has been obtained by single crystal X-ray diffraction. In all the cases, the metal is (2 + 2 + 1)-five-coordinated by two halide ligands, two nitrogen atoms from pyrazine and diazepine rings and a carbonyl oxygen from a pteridine ring. The coordinated-metal environment is a square-based pyramid, with increasing trigonality from Hg(ii) to Zn(ii) complexes. To coordinate the metals, the ligand folds itself, establishing four intramolecular σ-π interactions with the pyrimidine and pyrazine rings. A topological analysis of the electron density using the Quantum Theory of Atoms in Molecules and the complexes stability has been performed.

14.
J Chem Phys ; 145(5): 054903, 2016 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-27497578

RESUMO

Density functional theory calculations were carried out to investigate the evolvement of charge transport properties of a set of new discotic systems as a function of ring and heteroatom (B, Si, S, and Se) substitution on the basic structure of perylene. The replacement of six-membered rings by five-membered rings in the reference compound has shown a prominent effect on the electron reorganization energy that decreases ∼0.2 eV from perylene to the new carbon five-membered ring derivative. Heteroatom substitution with boron also revealed to lower the LUMO energy level and increase the electron affinity, therefore lowering the electron injection barrier compared to perylene. Since the rate of the charge transfer between two molecules in columnar discotic systems is strongly dependent on the orientation of the stacked cores, the total energy and transfer integral of a dimer as a disc is rotated with respect to the other along the stacking axis have been predicted. Aimed at obtaining a more realistic approach to the bulk structure, the molecular geometry of clusters made up of five discs was fully optimized, and charge transfer rate and mobilities were estimated for charge transport along a one dimensional pathway. Heteroatom substitution with selenium yields electron transfer integral values ∼0.3 eV with a relative disc orientation of 25°, which is the preferred angle according to the dimer energy profile. All the results indicate that the tetraselenium-substituted derivative, not synthetized so far, could be a promising candidate among those studied in this work for the fabrication of n-type semiconductors based on columnar discotic liquid crystals materials.

15.
J Inorg Biochem ; 143: 20-33, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25474363

RESUMO

The reactions of [RhCl(CO)(PPh3)2], [RhCl(CO)2]2 and [IrCl(CO)(PPh3)2] with different 5-nitrosopyrimidines afforded sixteen complexes which have been structurally characterized by elemental analysis, IR and NMR ((1)H and (13)C) spectral methods and luminescence spectroscopy. The crystal and molecular structures of [Rh(III)Cl(VIOH-1)2(PPh3)], [Rh(III)Cl(DVIOH-1)2(PPh3)] and [Rh(II)(DVIOH-1)2(PPh3)2] have been established from single crystal x-ray structure analyses. The three complexes are six-coordinated with both violurato ligands into an equatorial N5,O4-bidentate fashion, but with different mutually arrangements. Theoretical studies were driven on the molecular structure of [Rh(III)Cl(VIOH-1)2(PPh3)] to assess the nature of the metal-ligand interaction as well as the foundations of the cis-trans (3L-2L) isomerism. An assortment of density functional (SOGGA11-X, B1LYP, B3LYP, B3LYP-D3 and wB97XD) has been used, all of them leading to a similar description of the target system. Thus, a topological analysis of the electronic density within AIM scheme and the study of the Mulliken charges yield a metal-ligand link of ionic character. Likewise, it has been proved that the cis-trans isomerism is mainly founded on that metal-ligand interaction with the relativistic effects playing a significant role. Although most of the compounds showed low direct toxicity against the human cell lines NB69 (neuroblastoma) and U373-MG (astroglioma), they differently modify in several ways the renin-angiotensin system (RAS)-regulating proteolytic regulatory enzymes aminopeptidase A (APA), aminopeptidase N (APN) and insulin-regulated aminopeptidase (IRAP). Therefore, these complexes could exert antitumor activity against both brain tumor types, acting through the paracrine regulating system mediated by tissue RAS rather than exerting a direct cytotoxic effect on tumor cells.


Assuntos
Antineoplásicos , Neoplasias Encefálicas , Irídio , Neuroblastoma , Compostos Nitrosos , Peptídeo Hidrolases/metabolismo , Inibidores de Proteases , Pirimidinas , Sistema Renina-Angiotensina/efeitos dos fármacos , Ródio , Antineoplásicos/síntese química , Antineoplásicos/química , Antineoplásicos/farmacologia , Comunicação Autócrina/efeitos dos fármacos , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/enzimologia , Linhagem Celular Tumoral , Humanos , Irídio/química , Irídio/farmacologia , Modelos Químicos , Estrutura Molecular , Neuroblastoma/tratamento farmacológico , Neuroblastoma/enzimologia , Compostos Nitrosos/síntese química , Compostos Nitrosos/química , Compostos Nitrosos/farmacologia , Inibidores de Proteases/síntese química , Inibidores de Proteases/química , Inibidores de Proteases/farmacologia , Pirimidinas/síntese química , Pirimidinas/química , Pirimidinas/farmacologia , Ródio/química , Ródio/farmacologia
16.
J Chem Phys ; 140(4): 044908, 2014 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-25669584

RESUMO

Aimed to optimize the ratio accuracy/computational cost, in this work we study the performance of three different theoretical methodologies in the calculation of the optical bandgap for a test set made of a number of poly(aryl-ethynylene)s related polymers. Infinite, ideal polymer chains were first optimized by means of periodic calculations. Different length oligomers were afterward generated by direct replication of the corresponding periodic structure and their optical bandgaps were calculated by means of different time dependent-density functional theory (TD-DFT) methodologies. These results were fitted to an exponential function for each oligomer family in order to get a theoretical estimation of the optical bandgap for each polymer to be compared to the experimental reported values. The best result was obtained for TD-M06-2X yielding an average deviation of 3.4% with respect to the experimental values.


Assuntos
Modelos Teóricos , Polímeros/química , Estrutura Molecular
17.
Eur J Med Chem ; 64: 260-72, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23644209

RESUMO

The synthesis and molecular and supramolecular structures of the compound (6-amino-1-methyl-5-nitrosouracilato-N3)-triphenylphosphine-gold(I) with interesting abilities to inhibit tumor growth in an animal model of experimental glioma are reported. Thus, its antitumor properties, effects on both enzyme and non-enzyme antioxidant defense systems and the response of several biochemical biomarkers have been analyzed. After seven days of treatment, the gold compound decreased the tumor growth to ca. one-tenth and reduced oxidative stress biomarkers (thiobarbituric acid-reactive substances (TBARS) and protein oxidation levels) compared to animals treated with the vehicle. Also, gold compound maintained non-enzyme antioxidant defense systems as in non-tumor animals and increased enzyme antioxidant defenses, such as superoxide dismutase and glutathione peroxidase activities, and decreased catalase activity. Analysis of serum levels of electrolytes, nitrogenous compounds, glucose, lipids, total protein, albumin, transaminases and alkaline phosphatase indicated that gold compound treatment showed few adverse effects, while effectively inhibiting tumor growth through mechanisms that involved endogenous antioxidant defenses.


Assuntos
Antineoplásicos/farmacologia , Antioxidantes/farmacologia , Glioma/tratamento farmacológico , Compostos Organoáuricos/farmacologia , Uracila/análogos & derivados , Animais , Antineoplásicos/síntese química , Antineoplásicos/química , Antioxidantes/síntese química , Antioxidantes/química , Proliferação de Células/efeitos dos fármacos , Cristalografia por Raios X , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Glioma/patologia , Humanos , Masculino , Modelos Moleculares , Estrutura Molecular , Compostos Organoáuricos/síntese química , Compostos Organoáuricos/química , Estresse Oxidativo/efeitos dos fármacos , Ratos , Ratos Wistar , Relação Estrutura-Atividade , Células Tumorais Cultivadas , Uracila/síntese química , Uracila/química , Uracila/farmacologia
19.
J Mol Model ; 18(2): 815-24, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21618020

RESUMO

The title compound, C(6)H(4)N(4)S(2)·C(3)H(7)NO, crystallizes in the monoclinic space group C 2/c with a = 26.673(5), b = 5.397(1), c = 16.522(3) Å, ß = 95.49(3)°, Z = 8, R = 0.0461 for 1891 reflections with I > 2σ(I) and 174 parameters (4 restraints). Single pteridine-2,4(1 H,3 H)-dithione and dimethylformamide molecules are packed via N-H···O and N-H···N hydrogen bonds into centrosymmetric clusters containing two molecules of each class; these are roughly planar and placed into two different sets of planes -both containing the [-1,0,2] direction- mutually angled by 77.8°. Despite the distance between two neighbor planes in each set is ca. 3.4 Å, the analysis of π,π-stacking interactions shows too large slippage distance between aromatic rings from contiguous planes. Additional σ-π interactions between S2, S4 and O1S atoms and pyrazine or pyrimidine rings from adjacent molecules are present. The structure for the cluster [DTLM-DMF](2) has been simulated by using the density functionals B1B95 (6-31 G(d) and 6-31+G(d) basis sets) and M06-2X (6-31 G(d) basis set). As a result, the M06-2X/6-31 G(d) approach provides the best agreement with the experimental XRD data. For a better evaluation of the intermolecular interactions, the superposition of two dimeric adducts [DTLM-DMF](2) has been modelized. The binding capability of DTLM ligand was simulated on systems containing two metal-binding modes to palladium (N5-S4 and N1-S2) with different chelate size. The analysis of the frontier orbitals points out that the link with the metallic centers will take place through the sulfur atoms.


Assuntos
Dimetilformamida/química , Modelos Moleculares , Pteridinas/química , Tionas/química , Cristalografia por Raios X , Ligação de Hidrogênio , Ligantes
20.
Artigo em Inglês | MEDLINE | ID: mdl-22153593

RESUMO

Multi-parameter scaling techniques, such as Scaled Quantum Mechanical (SQM) force field [J. Am. Chem. Soc. 105 (1983) 7037-7047; J. Phys. Chem. A 102 (1998) 1412-1424] or Effective Scaling Frequency Factor (ESFF) [Chem. Phys. Lett. 446 (2007) 191-198; J. Mol. Spectrosc. 264 (2010) 66-74] techniques, are very powerful in the theoretical prediction of the vibrational spectra of complex molecules. In the present work sets of transferable SQM and ESFF scaling factors (within the valence coordinates based schemes) that can be applied to silicon- and sulfur(II)-containing compounds have been determined. A number of VDZ- and VTZ-quality basis sets were used in conjunction with the B3LYP density functional. Eight molecules typically used in the synthesis of silica-based materials were chosen, and theoretical modes were assigned to bands detected on their IR or Raman spectra. This set was augmented with a set of 10 auxiliary, sulfur(II)-containing molecules, for which only "pure" vibrations involving S-containing motifs were assigned. This led to the set of more than 600 individual vibrations. Five factors attributed to these motifs were optimized. Scaling factors attributed to the characteristic types of internal coordinates including the second-row atoms and chlorine, which are applicable to the present molecules were preset. Their values, optimized for Baker's training set of molecules [J. Phys. Chem. A 102 (1998) 1412-1424] for all basis sets considered in this work, were also found, extending thus the applicability of the multi-parameter scaling methods. New scaling factors exhibit low statistical uncertainties. Reasonable agreement between experimental and SQM- or ESFF-scaled frequencies was obtained even for the 6-31G* basis set (RMS<12cm(-1)); extension of the basis set by adding polarization function on hydrogen atoms and/or diffuse functions provides significant improvement of the results, for which the RMS values are often (well) below 10 cm(-1). In addition, SQM scaling factors were found to occasionally exhibit large deviations from unity, which is to be contrasted with ESFF scaling factors.


Assuntos
Teoria Quântica , Compostos de Silício/química , Compostos de Enxofre/química , Vibração , Simulação por Computador , Ligação de Hidrogênio , Espectroscopia de Infravermelho com Transformada de Fourier , Análise Espectral Raman , Compostos de Sulfidrila/química
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