RESUMO
Characterization of phases of soft matter systems is a challenge faced in many physical chemical problems. For polymorphic fluids it is an even greater challenge. Specifically, glass forming fluids, as water, can have, besides solid polymorphism, more than one liquid and glassy phases, and even a liquid-liquid critical point. In this sense, we apply a neural network algorithm to analyze the phase behavior of a mixture of core-softened fluids that interact through the continuous-shouldered well (CSW) potential, which have liquid polymorphism and liquid-liquid critical points, similar to water. We also apply the neural network to mixtures of CSW fluids and core-softened alcohols models. We combine and expand methods based on bond-orientational order parameters to study mixtures, applied to mixtures of hardcore fluids and to supercooled water, to include longer range coordination shells. With this, the trained neural network was able to properly predict the crystalline solid phases, the fluid phases and the amorphous phase for the pure CSW and CSW-alcohols mixtures with high efficiency. More than this, information about the phase populations, obtained from the network approach, can help verify if the phase transition is continuous or discontinuous, and also to interpret how the metastable amorphous region spreads along the stable high density fluid phase. These findings help to understand the behavior of supercooled polymorphic fluids and extend the comprehension of how amphiphilic solutes affect the phases behavior.
RESUMO
Intracerebral haemorrhage (ICH) is a worldwide public health problem. Experimental studies have shown that oxidative stress plays an important role in the pathogenesis of ICH and could represent a target for its treatment. However, the blood-brain barrier is an obstacle to be overcome, as it hampers the administration of compounds to the central nervous system. In this study, we compared the effects of a quercetin-loaded nanoemulsion (QU-N) with the free form of the drug (QU-SP) in a collagenase-induced ICH rat model. Quercetin (QU) is a polyphenol that has an antioxidant effect in vitro, but due to its high lipophilicity, it has low bioavailability in vivo. In this study, animals submitted or not to ICH were treated with a single intraperitoneal QU dose (free or nanoemulsion) of 30 mg kg(-1). Motor assessment was evaluated by the open field, foot fault and beam walking behavioural tests. 72 h after surgery the haematoma size was evaluated and biochemical measurements were performed. Animals treated with QU-N had a significant improvement in the beam walking and open field tests. Also, QU-N was able to reduce the size of the haematoma, preserving the activity of glutathione S-transferase (GST), increasing GSH content, and the total antioxidant capacity. QU-SP recovered locomotor activity and increased the GSH content and the total antioxidant capacity. Thus, it can be observed that QU presented antioxidant activity in both formulations, but the incorporation into nanoemulsions increased its antioxidant effect, which was reflected in the improvement of the motor skills and in the haematoma size decrement. These results suggest that the nanoemulsion containing QU developed in this study could be promising for future studies on treatments for ICH.
Assuntos
Antioxidantes/administração & dosagem , Hemorragia Cerebral/tratamento farmacológico , Portadores de Fármacos/química , Nanoestruturas/química , Quercetina/química , Animais , Antioxidantes/química , Antioxidantes/farmacologia , Peso Corporal/efeitos dos fármacos , Hemorragia Cerebral/etiologia , Cromatografia Líquida de Alta Pressão , Colagenases/metabolismo , Modelos Animais de Doenças , Emulsões/química , Glutationa/metabolismo , Glutationa Transferase/metabolismo , Locomoção/efeitos dos fármacos , Tamanho da Partícula , Quercetina/administração & dosagem , Quercetina/farmacologia , Ratos , Ratos WistarRESUMO
Cellular defence against the formation of reactive oxygen species (ROS) involves a number of mechanisms in which antioxidant enzymes such as catalase (CAT) and superoxide dismutase (SOD) play an important role. The relation between sleep deprivation and oxidative stress has not yet been completely elucidated. Although some authors did not find evidence of this relationship, others found alterations in some oxidative stress markers in response to sleep deprivation. Thus, the objective of this study was to identify changes induced by sleep deprivation in the activity and gene expression of antioxidant enzymes in mice splenocytes, ideally corroborating a better understanding of the observed effects related to sleep deprivation, which could be triggered by oxidative imbalance. Splenocytes from mice sleep deprived for 72 h showed no significant difference in CAT and CuZnSOD gene expression compared with normal sleep mice. However, sleep-deprived mice did show higher MnSOD gene expression than the control group. Concerning enzymatic activity, CuZnSOD and MnSOD significantly increased after sleep deprivation, despite the expression in CuZnSOD remained unchanged. Moreover, CAT activity was significantly lower after sleep deprivation. The data suggest that the antioxidant system is triggered by sleep deprivation, which in turn could influence the splenocytes homoeostasis, thus interfering in physiological responses.
Assuntos
Catalase/genética , Regulação Enzimológica da Expressão Gênica , Privação do Sono/fisiopatologia , Baço/metabolismo , Superóxido Dismutase/genética , Animais , Antioxidantes/metabolismo , Catalase/metabolismo , Peroxidação de Lipídeos , Masculino , Malondialdeído/metabolismo , Camundongos , Estresse Oxidativo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Baço/citologia , Superóxido Dismutase/metabolismo , Fatores de TempoRESUMO
OBJECTIVE: To review a single center's experience in the management of twin pregnancies with conjoined fetuses. METHODS: Retrospective study describing prenatal findings, delivery details, surgical treatment and perinatal outcome. RESULTS: The study included 36 twin pregnancies with conjoined twins seen over a period of 12 years in a single tertiary hospital: 69.4% were thoracopagus, 13.9% parapagus, 8.3% omphaloischiopagus 5.6% omphalopagus and 2.8% cephalopagus. Cardiac defects were present in 91.6% of twin pairs and associated malformations were present in 61.8% of the cases: limb abnormalities in 36.1%, abdominal wall defects in 25.0%, cleft lip and/or palate in 13.9% and congenital diaphragmatic hernia in 5.5%. Surgical separation was considered not feasible and prognosis lethal in 30 (83.3%) cases. Termination of pregnancy was performed in 12 pregnancies of poor prognosis. Cesarean section was performed in all remaining cases. Five sets of twins underwent surgical separation and six children survived. Overall survival in our series was 8.3% and, among the livebirths, 13.6%. CONCLUSION: Conjoined twin pregnancies should be referred to tertiary centers for detailed fetal anomaly and echocardiographic assessment to evaluate prognosis and determine the possibility of postnatal surgical separation.
Assuntos
Gêmeos Unidos/patologia , Adulto , Brasil , Parto Obstétrico , Feminino , Humanos , Masculino , Gravidez , Estudos Retrospectivos , Gêmeos Unidos/cirurgia , Adulto JovemRESUMO
This study evaluated the effect of the C-factor and dentin preparation method (DPM) in the bond strength (BS) of a mild self-etch adhesive; the study also observed the SEM superficial aspects of the corresponding smear layer. For purposes of this study, 25 molars (n=5) were used in a bond strength test. The molars were divided into two parts (buccal and lingual): one part received a Class V cavity (C-factor=3) and the other received a flat surface (C-factor=0) with the same bur type (coarse diamond or carbide bur and fine diamond or carbide bur), both within the same dentin depth. Five teeth were prepared with wet 60-grit and 600-grit SiC papers. After restoration with Clearfil SE Bond, microtensile beans (0.8 mm2) were prepared and tested after 24 hours in a universal testing machine (0.5 mm/minute). An additional two teeth for each DPM were prepared for SEM evaluation of the smear layer superficial aspects. The BS values were submitted to one-way ANOVA, considering only the DPM (flat surfaces) and two-way ANOVA (C-Factor x DPM, considering only burs) with p=0.05. Although the DPM in the flat surfaces was not significant, the standard deviations of carbide bur-prepared specimens were markedly lower. The BS was significantly lower in cavities. The fine carbide bur presented the most favorable smear layer aspect. It was concluded that different dentin preparation methods could not prevent the adverse effect in bond strength of a high C-factor. A coarse cut carbide bur should be avoided prior to a mild self-etch adhesive, because it adversely affected bond strength. In contrast, a fine cut carbide bur provided the best combination: high bond strength with low variability, which suggests a more reliable bond strength performance.
Assuntos
Colagem Dentária , Preparo da Cavidade Dentária , Cimentos Dentários , Corrosão Dentária , Análise do Estresse Dentário , Dentina/ultraestrutura , Equipamentos Odontológicos de Alta Rotação , Adesivos Dentinários , Humanos , Técnicas In Vitro , Dente MolarRESUMO
Estresse, correria, poluiçåo e preocupações såo alguns dos problemas da vida moderna que mexem com a nossa saúde e tiram nossa energia. Atividades como a medicina complementar podem repor essa energia perdida, proporcionando a vitalidade, a calma, o alívio das dores, a melhoria da circulaçåo sangüinea e o tônus muscular, dentre outros benefícios. Este trabalho tem como objetivo apresentar a experiência com atividades de medicina complementar, inicidas em maio de 2002, dentro da ações de educaçåo em saúde, desenvolvidas na comunidade de Nazaré-Inabi, no município de Macaragibe. O trabalho ocorreu sob a orientaçåo dos profissionais da equipe e de convidados que realizam, em outros espaços, atividades com este fim.
Assuntos
Terapias Complementares , Saúde da FamíliaRESUMO
Leguminous trees are being suggested for revegetation programs due to their ability to develop associations with rhizobia and mycorrhizal fungi. The growth of a native species of the Tropical Atlantic Forest, Centrolobium tomentosum, was evaluated in a native forest soil and in a Eucalyptus forest soil under different treatments of inoculation. C. tomentosum produced more biomass under nursery conditions after inoculation with Rhizobium BHICB-Ab1 associated with arbuscular mycorrhizal (AM). This treatment improved shoot and root growth and nodule weight under forest soil condition, while in eucalyptus soil only shoot biomass and nodule weight were significantly modified. In another experiment, using forest soil, height and stem diameter were also increased by dual inoculation procedures. The height and diameter growth promoting effect was observed when BHICB-Ab1 was used as inoculant associated with AM, but not with BHICB-Ab1 alone. In contrast, plants inoculated with BHICB-Ab3 alone were similar in height and diameter growth, to those which were inoculated with BHICB-Ab3 associated with AM. These results suggest that benefits of dual inoculation depend on triparty symbiosis and especially on the choice of Rhizobium strain.
Assuntos
Fungos/fisiologia , Rhizobium/fisiologia , Árvores/microbiologia , Biomassa , Fixação de Nitrogênio , Raízes de Plantas/microbiologia , Solo , Simbiose , Árvores/crescimento & desenvolvimentoRESUMO
The steam volatile components from the hexane extract of dried flower buds of Egletes viscosa were identified by gas chromatography-mass spectrometry as trans-carvyl acetate, cis-carvyl acetate, sabinyl acetate, verbenyl acetate, cyclopentaethylidene, geranyl acetate and 5-methylfuranone, and trans-pinocarvyl acetate (major component). From the non-volatile residue, centipedic acid and a novel clerodane diterpene, 12-acetoxy-hawtriwaic acid lactone, were isolated. From the ethanol extract, ternatin (4',5-dihidroxy-3,3',7,8-tetramethoxyflavone), was isolated. Ternatin showed anti-inflammatory, hepatoprotection and gastroprotection properties, and, according to the NCI protocols, it showed moderate activity against HIV. The diterpenes showed antispasmodic activity. Structure determination of these secondary metabolites was accomplished by spectrometric methods, including 2D NMR, chemical interconversion and X-ray crystallographic analysis.
Assuntos
Antivirais/química , Flavonoides/química , HIV/efeitos dos fármacos , Plantas Medicinais , Terpenos/química , Anti-Inflamatórios não Esteroides/química , Anti-Inflamatórios não Esteroides/isolamento & purificação , Anti-Inflamatórios não Esteroides/farmacologia , Antivirais/isolamento & purificação , Antivirais/farmacologia , Brasil , Cristalografia por Raios X , Diterpenos/química , Diterpenos/isolamento & purificação , Diterpenos/farmacologia , Flavonoides/isolamento & purificação , Flavonoides/farmacologia , Humanos , Espectroscopia de Ressonância Magnética , Medicina Tradicional , Modelos Moleculares , Estrutura Molecular , Parassimpatolíticos/química , Parassimpatolíticos/isolamento & purificação , Parassimpatolíticos/farmacologia , Extratos Vegetais , Relação Estrutura-Atividade , Terpenos/isolamento & purificação , Terpenos/farmacologiaRESUMO
There is some uncertainty about the extent to which Latin America and the Caribbean have participated in the advances of health-related industrial biotechnology. This article reviews the available literature and seeks to provide an overview of the prevailing situation. In general, national governments and multinational agencies have provided most of the health-related biotechnology investments within this region. Efforts to achieve technology transfers, a subject of prime concern, have been developed by a number of programs including the WHO Special Programme for Research and Training in Tropical Diseases, the UNDP/UNESCO/UNIDO Regional Biotechnology Program for Latin America and the Caribbean; PAHO's Program for the Regional Development of Biotechnology as Applied to Health; the PAHO/WHO Expanded Program of Immunization (EPI); and PAHO's Regional System of Vaccines (SIREVA). Regarding current production capacity, some successful efforts have been made to produce a variety of therapeutic products including recombinant and natural ionterferons, interleukins, insulin, and recombinant streptokinase; but in general the region's current potential in this area is at best incipient and uncertain. However, the region does have a limited ability to make diagnostic products and a well-established capacity for vaccine development. Overall, this picture suggests that the region has the potential to play a small but significant role in health-related biotechnology (AU).
Assuntos
Humanos , Biotecnologia/tendências , Serviços de Saúde/tendências , Produtos Biológicos/biossíntese , Pesquisa , Financiamento Governamental , Agências Internacionais , Transferência de Tecnologia , Vacinas/biossíntese , América Latina , Região do CaribeRESUMO
Fractures of the lower radius with anterior displacement of the distal fragment are very uncommon injuries. These injuries, designated Smiths' and Barton's Fractures, tend to be readily confused with and misdiagnosed as the commoner Colles' fracture in which the distal fragment is displaced posteriorly, producing the well-known clinical "Dinner Fork Deformity". Between January 1977 and October 1984, 12 fractures of the distal radius with anterior displacement were seen and treated at the Queen Elizabeth Hospital. The case notes and radiographs of these 12 patients were studied, and nine were available for interview and examination. The injuries arose from falls (5), cycle accidents (6), and blows to the back of the hand (1). Two fractures were in children. In ten of the 12 cases the initial diagnosis was incorrect. On average presentation was late, 3 to 4 days, with one patient presenting one month after injury. Most fractures were treated by open reduction and fixation; three, including two children, were treated by manipulation and Plaster-of-Paris (AU)