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1.
Conserv Biol ; 2022 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-35098582

RESUMO

An important rationale for legally-farmed and synthetic wildlife products are that they reduce illegal wild-sourced trade by supplying markets with sustainable alternatives. For this to work, more established illegal-product consumers must switch to legal alternatives than new legal-product consumers drawn to illegal wild products. Despite widespread debate on the magnitude and direction of switching, studies among actual consumers are lacking. We used an anonymous online survey of 1421 Traditional Chinese Medicine consumers in China to investigate switching between legal farmed, synthetic, and illegal wild bear bile. We examined past consumption behaviour, and applied a discrete choice experiment framed within worsening hypothetical disease scenarios, using latent class models to investigate groups with shared preferences. Bear bile consumers (86% respondents) were wealthier, more likely to have family who consumed bile, and less knowledgeable about bile treatments than non-consumers. Consumer preferences were heterogenous but most consumers preferred switching between bile types as disease worsened. We identified five distinct latent classes within our sample: 'law-abiding consumers' (34% respondents), who prefer legal products and were unlikely to switch; two 'all-natural consumer' groups (53%), who dislike synthetics but may switch between farmed and wild products; and two 'non-consumer' groups (12%) who prefer not to buy bile. People with past experience of bile consumption had different preferences than those without. Willingness to switch to wild products was related to believing they were legal, although the likelihood of switching was mediated by preferences for cheaper products sold in legal, familiar places. We show that consumers of wild bile may switch, given the availability of a range of legal alternatives, while legal-product consumers may switch to illegal products if the barriers to doing so are small. Understanding preferences that promote or impede switching should be a key consideration when attempting to predict consumer behaviour in complex wildlife markets. This article is protected by copyright. All rights reserved.


Wildlife consumer characteristics and preferences determine their likelihood and direction of switching between legal and illegal products.

2.
Neurol Sci ; 41(3): 733, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31909448

RESUMO

The above article was published online with incorrect abbreviations in Figures 2 and 3 last sentence of the legend. HDA should be corrected to HADS.

3.
Neurol Sci ; 41(2): 281-293, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31494820

RESUMO

OBJECTIVE: To evaluate the safety and efficacy of Cerebrolysin as an add-on therapy to local standard treatment protocol in patients after moderate-to-severe traumatic brain injury. METHODS: The patients received the study medication in addition to standard care (50 mL of Cerebrolysin or physiological saline solution daily for 10 days, followed by two additional treatment cycles with 10 mL daily for 10 days) in a prospective, randomized, double-blind, placebo-controlled, parallel-group, multi-centre phase IIIb/IV trial. The primary endpoint was a multidimensional ensemble of 14 outcome scales pooled to be analyzed by means of the multivariate, correlation-sensitive Wei-Lachin procedure. RESULTS: In 46 enrolled TBI patients (Cerebrolysin 22, placebo 24), three single outcomes showed stand-alone statistically significant superiority of Cerebrolysin [Stroop Word/Dots Interference (p = 0.0415, Mann-Whitney(MW) = 0.6816, 95% CI 0.51-0.86); Color Trails Tests 1 and 2 (p = 0.0223/0.0170, MW = 0.72/0.73, 95% CI 0.53-0.90/0.54-0.91), both effect sizes lying above the benchmark for "large" superiority (MW > 0.71)]. While for the primary multivariate ensemble, statistical significance was just missed in the intention-to-treat population (pWei-Lachin < 0.1, MWcombined = 0.63, 95% CI 0.48-0.77, derived standardized mean difference (SMD) 0.45, 95% CI -0.07 to 1.04, derived OR 2.1, 95% CI 0.89-5.95), the per-protocol analysis showed a statistical significant superiority of Cerebrolysin (pWei-Lachin = 0.0240, MWcombined = 0.69, 95% CI 0.53 to 0.85, derived SMD 0.69, 95% CI 0.09 to 1.47, derived OR 3.2, 95% CI 1.16 to 12.8), with effect sizes of six single outcomes lying above the benchmark for "large" superiority. Safety aspects were comparable to placebo. CONCLUSION: Our trial suggests beneficial effects of Cerebrolysin on outcome after TBI. Results should be confirmed by a larger RCT with a comparable multidimensional approach.


Assuntos
Aminoácidos/farmacologia , Lesões Encefálicas Traumáticas/tratamento farmacológico , Disfunção Cognitiva/tratamento farmacológico , Fármacos Neuroprotetores/farmacologia , Avaliação de Resultados em Cuidados de Saúde , Doença Aguda , Adulto , Aminoácidos/administração & dosagem , Aminoácidos/efeitos adversos , Sudeste Asiático , Lesões Encefálicas Traumáticas/complicações , Disfunção Cognitiva/etiologia , Método Duplo-Cego , Ásia Oriental , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fármacos Neuroprotetores/administração & dosagem , Fármacos Neuroprotetores/efeitos adversos , Índice de Gravidade de Doença , Adulto Jovem
4.
BMC Psychiatry ; 19(1): 225, 2019 07 23.
Artigo em Inglês | MEDLINE | ID: mdl-31337373

RESUMO

BACKGROUND: Cognitive Bias Modification (CBM) has been used successfully as a computer-based intervention in disorders such as anxiety. However, CBM to modify interpretations of ambiguous information relevant to paranoia has not yet been tested. We conducted a qualitative investigation of a novel intervention called CBM for paranoia (CBM-pa) to examine its acceptability in patients with psychosis. METHODS: Eight participants with psychosis who completed CBM-pa were identified by purposive sampling and invited for a semi-structured interview to explore the facilitators and barriers to participation, optimum form of delivery, perceived usefulness of CBM-pa and their opinions on applying CBM-pa as a computerised intervention. The interviews were transcribed and analysed using thematic analysis by researchers working in collaboration with service users. RESULTS: Themes emerged relating to participants' perception about delivery, engagement, programme understanding, factors influencing experience, perceived impact and application of CBM-pa. CBM-pa was regarded as easy, straightforward and enjoyable. It was well-accepted among those we interviewed, who understood the procedure as a psychological intervention. Patients reported that it increased their capacity for adopting alternative interpretations of emotionally ambiguous scenarios. Although participants all agreed on the test-like nature of the current CBM-pa format, they considered that taking part in sessions had improved their overall wellbeing. Most of them valued the computer-based interface of CBM-pa but favoured the idea of combining CBM-pa with some form of human interaction. CONCLUSIONS: CBM-pa is an acceptable intervention that was well-received by our sample of patients with paranoia. The current findings reflect positively on the acceptability and experience of CBM-pa in the target population. Patient opinion supports further development and testing of CBM-pa as a possible adjunct treatment for paranoia. TRIAL REGISTRATION: Current Controlled Trials ISRCTN: 90749868 . Retrospectively registered on 12 May 2016.


Assuntos
Terapia Cognitivo-Comportamental/métodos , Transtornos Paranoides/terapia , Aceitação pelo Paciente de Cuidados de Saúde/psicologia , Transtornos Psicóticos/terapia , Adulto , Feminino , Humanos , Masculino , Transtornos Paranoides/psicologia , Transtornos Psicóticos/psicologia , Pesquisa Qualitativa , Interface Usuário-Computador
5.
Eur J Cancer Care (Engl) ; 27(4): e12857, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29767417

RESUMO

This study examined concordances of cancer patients' received and caregivers' provided support and dyadic relationship quality, and their predictive utility in prospective psychological distress and well-being. A total of 83 Chinese cancer patient-caregiver dyads were recruited in two government-funded hospitals in Hong Kong. Participants reported received (patient)/provided (caregiver) emotional and instrumental support and dyadic relationship quality within 6 months after diagnosis (T1), and anxiety and depressive symptoms, positive affect and life satisfaction at both T1 and 6-month follow-up (T2). We hypothesised that concordances at T1 would predict lower psychological distress and higher psychological well-being among both patients and caregivers at T2. Concordances were indicated by Gwet's AC2 scores (possible range = -1.00 to 1.00) and as follows: emotional support: M = 0.92, SD = 0.12, range = 0.25-1.00; instrumental support: M = 0.92, SD = 0.16, range = 0.08-1.00; and relationship quality: M = 0.63, SD = 0.27, range = -0.31 to 1.00. Hierarchical multiple regressions revealed that T1 concordances of perceived emotional and instrumental support and dyadic relationship quality positively predicted T2 anxiety symptoms [F(9, 74) = 6.725, ∆R2  = .031, p < .001)] and state positive affect [F(9, 74) = 3.436, ∆R2  = .042, p = .001)], whereas inversely predicted T2 depressive symptoms [F(9, 74) = 4.189, ∆R2  = .042, p < .01)]. Significant associations were found only among caregivers, but not patients.


Assuntos
Ansiedade/psicologia , Cuidadores/psicologia , Depressão/psicologia , Relações Interpessoais , Neoplasias/enfermagem , Apoio Social , Estresse Psicológico/psicologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Hong Kong , Humanos , Masculino , Saúde Mental , Pessoa de Meia-Idade , Neoplasias/psicologia , Adulto Jovem
6.
Lab Invest ; 97(3): 243-255, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-27991911

RESUMO

Although endothelin (ET)-1 has been shown to upregulate nerve growth factor (NGF) expression, the molecular mechanisms are largely unknown. Phosphatidylinositol 3-kinase (PI3K)/Akt/glycogen synthase kinase (GSK)-3ß signal has been implicated in the regulation of NGF. We investigated whether selective ET receptor blockers attenuated cardiac sympathetic reinnervation through restoring PI3K/Akt/GSK-3ß activity. After ligation of the left anterior descending artery, male Wistar rats were randomized to either vehicle, atrasentan (an ETA receptor antagonist) or A-192621 (an ETB receptor antagonist) for 4 weeks. Sympathetic hyperinnervation after infarction was confirmed by myocardial norepinephrine measurement and immunofluorescent analysis. Post infarction was associated with increased reactive oxygen species (ROS), as measured by myocardial superoxide levels and dihydroethidine fluorescence staining. This was paralleled by a significant upregulation of NGF expression on mRNA and protein levels in the vehicle-treated rats, which reduced after administering atrasentan, not A-192621. Arrhythmic scores in the vehicle-treated rats were significantly higher than those treated with atrasentan. In an in vivo study atrasentan-induced decreased NGF was associated with activation of PI3K/Akt signaling pathway, which was further confirmed by the ex vivo study showing the restoration of NGF levels after coadministration of PI3K inhibitors (wortmannin and LY294002). Lithium chloride, an inhibitor of GSK-3ß, did not provide additional attenuated NGF levels compared with atrasentan alone. Finally, atrasentan-attenuated NGF levels were reversed in the presence of peroxynitrite generator. ETA receptor antagonism is a mediator to attenuate sympathetic hyperinnervation probably through restoration of PI3K/Akt/GSK-3ß/ROS signaling pathway, a potential pharmacological target for arrhythmias after infarction.


Assuntos
Antagonistas dos Receptores de Endotelina/farmacologia , Glicogênio Sintase Quinase 3 beta/metabolismo , Infarto do Miocárdio/prevenção & controle , Fosfatidilinositol 3-Quinase/metabolismo , Transdução de Sinais/efeitos dos fármacos , Sistema Nervoso Simpático/efeitos dos fármacos , Animais , Arritmias Cardíacas/genética , Arritmias Cardíacas/metabolismo , Arritmias Cardíacas/prevenção & controle , Atrasentana , Western Blotting , Inibidores Enzimáticos/farmacologia , Glicogênio Sintase Quinase 3 beta/antagonistas & inibidores , Coração/efeitos dos fármacos , Coração/inervação , Coração/fisiopatologia , Masculino , Infarto do Miocárdio/genética , Infarto do Miocárdio/metabolismo , Miocárdio/metabolismo , Fator de Crescimento Neural/genética , Fator de Crescimento Neural/metabolismo , Norepinefrina/metabolismo , Inibidores de Fosfoinositídeo-3 Quinase , Proteínas Proto-Oncogênicas c-akt/metabolismo , Pirrolidinas/farmacologia , Distribuição Aleatória , Ratos Wistar , Espécies Reativas de Oxigênio/metabolismo , Receptores de Endotelina/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sistema Nervoso Simpático/metabolismo , Sistema Nervoso Simpático/fisiopatologia
7.
Psychol Med ; 46(12): 2485-99, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27328861

RESUMO

BACKGROUND: Late-life depression (LLD) in the elderly was reported to present with emotion dysregulation accompanied by high perceived loneliness. Previous research has suggested that LLD is a disorder of connectivity and is associated with aberrant network properties. On the other hand, perceived loneliness is found to adversely affect the brain, but little is known about its neurobiological basis in LLD. The current study investigated the relationships between the structural connectivity, functional connectivity during affective processing, and perceived loneliness in LLD. METHOD: The current study included 54 participants aged >60 years of whom 31 were diagnosed with LLD. Diffusion tensor imaging (DTI) data and task-based functional magnetic resonance imaging (fMRI) data of an affective processing task were collected. Network-based statistics and graph theory techniques were applied, and the participants' perceived loneliness and depression level were measured. The affective processing task included viewing affective stimuli. RESULTS: Structurally, a loneliness-related sub-network was identified across all subjects. Functionally, perceived loneliness was related to connectivity differently in LLD than that in controls when they were processing negative stimuli, with aberrant networking in subcortical area. CONCLUSIONS: Perceived loneliness was identified to have a unique role in relation to the negative affective processing in LLD at the functional brain connectional and network levels. The findings increas our understanding of LLD and provide initial evidence of the neurobiological mechanisms of loneliness in LLD. Loneliness might be a potential intervention target in depressive patients.


Assuntos
Envelhecimento , Conectoma/métodos , Transtorno Depressivo Maior/fisiopatologia , Solidão , Rede Nervosa/fisiopatologia , Idoso , Transtorno Depressivo Maior/diagnóstico por imagem , Imagem de Tensor de Difusão , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Rede Nervosa/diagnóstico por imagem
8.
Am J Transplant ; 14(2): 453-8, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24354898

RESUMO

High pulmonary vascular resistance index (PVRI) can lead to right ventricular dysfunction and failure of the donor heart early after pediatric heart transplantation. Oral pulmonary vasodilators such as sildenafil have been shown to be effective modifiers of pulmonary vascular tone. We performed a retrospective, observational study comparing patients treated with sildenafil ("sildenafil group") to those not treated with sildenafil ("nonsildenafil group") after heart transplantation from 2007 to 2012. Pre- and posttransplant data were obtained, including hemodynamic data from right heart catheterizations. Twenty-four of 97 (25%) transplant recipients were transitioned to sildenafil from other systemic vasodilators. Pretransplant PVRI was higher in the sildenafil group (6.8 ± 3.9 indexed Woods units [WU]) as compared to the nonsildenafil group (2.5 ± 1.7 WU, p=0.002). In the sildenafil group posttransplant, there were significant decreases in systolic pulmonary artery pressure, mean pulmonary artery pressure, transpulmonary gradient and PVRI (4.7 ± 2.9 WU before sildenafil initiation to 2.7 ± 1 WU on sildenafil, p=0.0007). While intubation time, length of inotrope use and time to hospital discharge were longer in the sildenafil group, survival was similar between both groups. Oral sildenafil was associated with a significant improvement in right ventricular dysfunction and invasive hemodynamic measurements in pediatric heart transplant recipients with high PVRI early after transplant.


Assuntos
Transplante de Coração/efeitos adversos , Piperazinas/uso terapêutico , Complicações Pós-Operatórias/tratamento farmacológico , Sulfonas/uso terapêutico , Vasodilatadores/uso terapêutico , Disfunção Ventricular Direita/tratamento farmacológico , Adolescente , Adulto , Cateterismo Cardíaco , Criança , Pré-Escolar , Feminino , Seguimentos , Humanos , Lactente , Masculino , Complicações Pós-Operatórias/etiologia , Prognóstico , Purinas/uso terapêutico , Estudos Retrospectivos , Citrato de Sildenafila , Disfunção Ventricular Direita/etiologia , Adulto Jovem
9.
Diabet Med ; 28(4): 493-9, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21392070

RESUMO

AIMS: The presence of subclinical stenosed coronary segments and plaque subtypes has not been compared among those with metabolic syndrome, diabetes, or neither condition in middle-aged individuals. In select, intermediate-risk subjects, it may be reasonable to directly measure atherosclerosis burden by low-dose, multidetector-row computed tomographic coronary angiography. METHODS: We performed a cross-sectional analysis of 1024 consecutive, newly self-referred subjects (692 men, 332 women; mean age 53.0±9.7 years) who underwent health evaluation at the China Medical University Hospital. Participants had at least one cardiac risk factor, but no known coronary heart disease. RESULTS: Among our 1024 subjects, 135 had diabetes, 334 had metabolic syndrome and 555 had neither condition. The subjects with diabetes and those with metabolic syndrome had a higher prevalence of non-calcified, calcified and mixed-type plaques and stenosed coronary segments than the subjects with neither condition (P<0.05). The odds ratios for diabetes and the presence of any plaque, mixed plaque, calcified plaque and stenosed segment compared with neither metabolic syndrome nor diabetes were 2.893, 3.629, 2.099 and 2.036, respectively, all of which were significant (P<0.05). The odds ratio for metabolic syndrome and the presence of any plaque compared with neither metabolic syndrome nor diabetes was 1.606 (95% CI 1.063-2.426; P<0.05). CONCLUSION: In middle-aged subjects, diabetes was related to an increased risk of the presence of mixed plaques, calcified plaques and stenosed coronary segments. However, metabolic syndrome was related to an increased risk of the presence of any coronary plaque, but not related to stenosed coronary segments.


Assuntos
Doença da Artéria Coronariana/radioterapia , Estenose Coronária/diagnóstico por imagem , Diabetes Mellitus Tipo 2/diagnóstico por imagem , Angiopatias Diabéticas/diagnóstico por imagem , Síndrome Metabólica/diagnóstico por imagem , China , Angiografia Coronária , Doença da Artéria Coronariana/etiologia , Estenose Coronária/etiologia , Estudos Transversais , Diabetes Mellitus Tipo 2/complicações , Feminino , Humanos , Masculino , Síndrome Metabólica/complicações , Pessoa de Meia-Idade , Fatores de Risco , Tomografia Computadorizada por Raios X
10.
Dev Neurosci ; 31(4): 276-84, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19546564

RESUMO

Sleep deprivation among adolescents is epidemic. We argue that this sleep deprivation is due in part to pubertal changes in the homeostatic and circadian regulation of sleep. These changes promote a delayed sleep phase that is exacerbated by evening light exposure and incompatible with aspects of modern society, notably early school start times. In this review of human and animal literature, we demonstrate that delayed sleep phase during puberty is likely a common phenomenon in mammals, not specific to human adolescents, and we provide insight into the mechanisms underlying this phenomenon.


Assuntos
Comportamento do Adolescente/fisiologia , Ritmo Circadiano/fisiologia , Homeostase/fisiologia , Privação do Sono/fisiopatologia , Sono/fisiologia , Adolescente , Animais , Relógios Biológicos/fisiologia , Feminino , Hormônios Gonadais/metabolismo , Humanos , Luz , Masculino , Fotoperíodo , Puberdade/fisiologia
11.
Psychol Med ; 39(7): 1097-106, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18945378

RESUMO

BACKGROUND: Patients with major depressive disorder are found to show selective attention biases towards mood-congruent information. Although previous studies have identified various structural changes in the brains of these patients, it remains unclear whether the structural abnormalities are associated with these attention biases. In this study, we used voxel-based morphometry (VBM) to explore the structural correlates of attention biases towards depression-related stimuli. METHOD: Seventeen female patients with major depressive disorder and 17 female healthy controls, matched on age and intelligence, underwent magnetic resonance imaging (MRI). They also performed positive-priming (PP) and negative-priming (NP) tasks involving neutral and negative words that assessed selective attention biases. The reaction time (RT) to a target word that had been attended to or ignored in a preceding trial was measured on the PP and NP tasks respectively. The structural differences between the two groups were correlated with the indexes of attention biases towards the negative words. RESULTS: The enhanced facilitation of attention to stimuli in the PP task by the negative valence was only found in the depressed patients, not in the healthy controls. Such attention biases towards negative stimuli were found to be associated with reduced gray-matter concentration (GMC) in the right superior frontal gyrus, the right anterior cingulate gyrus and the right fusiform gyrus. No differential effect in inhibition of attention towards negative stimuli in the NP task was found between the depressed patients and the healthy controls. CONCLUSIONS: Specific structural abnormalities in depression are associated with their attention biases towards mood-congruent information.


Assuntos
Afeto/fisiologia , Atenção/fisiologia , Encéfalo/fisiopatologia , Transtorno Depressivo Maior/fisiopatologia , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Semântica , Adulto , Mapeamento Encefálico , Sinais (Psicologia) , Dominância Cerebral/fisiologia , Feminino , Lobo Frontal/fisiopatologia , Giro do Cíngulo/fisiopatologia , Humanos , Sistema Límbico/fisiopatologia , Pessoa de Meia-Idade , Rede Nervosa/fisiopatologia , Inventário de Personalidade/estatística & dados numéricos , Psicometria , Tempo de Reação/fisiologia , Leitura , Valores de Referência , Lobo Temporal/fisiopatologia
12.
J Inherit Metab Dis ; 32 Suppl 1: S97-101, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19238581

RESUMO

Propionic acidaemia (PA) is an autosomal recessive disease that results from deficiency of propionyl-CoA carboxylase (PCC). In the majority of reported cases, the phenotype includes metabolic acidosis and/or neurological deficits. We report on a 14-year-old Asian-American male with PA who presented with isolated cardiomyopathy without any documented episodes of metabolic acidosis or evidence of any neurocognitive deficits. On routine metabolic screening, the patient was found to have urine organic acids suggestive of PA. Biochemical and genetic characterization confirmed a PCC deficiency with two novel mutations in PCCB: IVS7 + 2 T > G (c.763 + 2 T > G) and p.R410Q (c.1229 G > A). Residual enzyme activity likely explains our patient's mild phenotype. Splicing mutations tend to result in a milder phenotype as these mutations may still produce small amounts of normal enzyme. In addition, the similar p.R410W mutation has been shown to have partial residual activity. Moreover, this case illustrates that a thorough metabolic evaluation should be performed in both paediatric and adult patients with cardiomyopathy. Such an evaluation has important implications for clinical management and genetic counselling.


Assuntos
Cardiomiopatias/diagnóstico , Propionatos/sangue , Acidemia Propiônica/diagnóstico , Adolescente , Sequência de Bases , Cardiomiopatias/enzimologia , Cardiomiopatias/genética , Transplante de Coração , Humanos , Masculino , Metilmalonil-CoA Descarboxilase/genética , Mutação , Fenótipo , Acidemia Propiônica/enzimologia , Acidemia Propiônica/genética
14.
Plant Cell ; 5(2): 171-179, 1993 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-12271060

RESUMO

Increases in the terrestrial levels of ultraviolet-B (UV-B) radiation (280 to 320 nm) due to diminished stratospheric ozone have prompted an investigation of the protective mechanisms that contribute to UV-B tolerance in plants. In response to UV-B stress, flowering plants produce a variety of UV-absorptive secondary products derived from phenylalanine. Arabidopsis mutants with defects in the synthesis of these compounds were tested for UV-B sensitivity. The transparent testa-4 (tt4) mutant, which has reduced flavonoids and normal levels of sinapate esters, is more sensitive to UV-B than the wild type when grown under high UV-B irradiance. The tt5 and tt6 mutants, which have reduced levels of UV-absorptive leaf flavonoids and the monocyclic sinapic acid ester phenolic compounds, are highly sensitive to the damaging effects of UV-B radiation. These results demonstrate that both flavonoids and other phenolic compounds play important roles in vivo in plant UV-B protection.

15.
J Dent Res ; 86(6): 539-43, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17525354

RESUMO

For dental orthodontic applications, NiTi wires are used under bending conditions in the oral environment for a long period. The purpose of this study was to investigate the effect of bending stress on the corrosion of NiTi wires using potentiodynamic and potentiostatic tests in artificial saliva. The results indicated that bending stress induces a higher corrosion rate of NiTi wires in passive regions. It is suggested that the passive oxide film of specimens would be damaged under bending conditions. Auger electron spectroscopic analysis showed a lower thickness of passive films on stressed NiTi wires compared with unstressed specimens in the passive region. By scanning electron microscopy, localized corrosion was observed on stressed Sentalloy specimens after a potentiodynamic test at pH 2. In conclusion, this study indicated that bending stress changed the corrosion properties and surface characteristics of NiTi wires in a simulated intra-oral environment.


Assuntos
Ligas Dentárias/química , Níquel/química , Fios Ortodônticos , Titânio/química , Corrosão , Eletroquímica , Microanálise por Sonda Eletrônica , Humanos , Concentração de Íons de Hidrogênio , Teste de Materiais , Microscopia Eletrônica de Varredura , Óxidos/química , Potenciometria , Saliva Artificial/química , Estresse Mecânico , Propriedades de Superfície , Suporte de Carga
16.
J Biomed Mater Res A ; 83(2): 263-71, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17415765

RESUMO

This study was undertaken to evaluate the effect of post-hydrothermal treatment on the biological responses of the plasma-sprayed hydroxyapatite (HA)-coated Ti-6Al-4V implant system both in vitro and in vivo. After hydrothermal treatment, the HA coating (HAC) shows the high mechanical strength and indices-of-crystallinity, denser microstructure, lower concentrations of amorphous and impurity phases, when compared with the as-sprayed HAC. The in vitro cell-culture studies, using UMR106 osteoblast-like cell, demonstrated no signifiacnt cell growth on both surface of as-sprayed and hydrothermal-treated HACs during 10-day culture. The in vivo studies, using the transcortical implant model in the femora of goats, evaluated the histological responses of two coatings. After 6 week of implantation, using backscattered electron images, no substantial histological variations in the extents of new bone apposition and new bone healing between the two HACs were observed. However, the as-sprayed HAC, owing to the dissolution induced the granular particles dissociated from the HAC, showed the statically lower extent of new bone apposition than hydrothermal-treated HAC at 12 weeks. The results suggest that hydrothermal treatment could be used to improve the mechanical strength, crystallinity, and phase composition of HAC, which are important factors of long-term fixation and stability of implant. Besides, the treated HAC could also achieve the initial fixation of implant in clinical use.


Assuntos
Materiais Revestidos Biocompatíveis/metabolismo , Durapatita/metabolismo , Teste de Materiais/métodos , Temperatura , Animais , Linhagem Celular , Proliferação de Células , Fêmur/citologia , Fêmur/ultraestrutura , Cabras , Implantes Experimentais , Modelos Biológicos , Ratos
17.
J Biomed Mater Res B Appl Biomater ; 82(2): 450-9, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17245748

RESUMO

A porous metal coating applied to solid substrate implants has been shown, in vivo, to anchor implants by bone ingrowth. Calcium phosphate ceramics, in particular hydroxyapatite [Ca(10)(PO(4))(6)(OH)(2), HA], are bioactive ceramics, which are known to be biocompatible and osteoconductive, and these ceramics deposited on to porous-coated devices may enhance bone ingrowth and implant fixation. In this study, bi-feedstock of the titanium powder and composite (Na(2)CO(3)/HA) powder were simultaneously deposited on a Ti-6Al-4V substrate by a plasma sprayed method. At high temperature of plasma torch, the solid state of Na(2)CO(3) would decompose to release CO(2) gas and then eject the molten Ti powder to induce the interconnected pores in the coatings. After cleaning and soaking in deionized water, the residual Na(2)CO(3) in the coating would dissolve to form the open pores, and the HA would exist at the surface of pores in the inner coatings. By varying the particle size of the composite powder, the porosity of porous coating could be varied from 25.0 to 34.0%, and the average pore size of the porous coating could be varied to range between 158.5 and 202.0 microm. Using a standard adhesive test (ASTM C-633), the bonding strength of the coating is between 27.3 and 38.2 MPa. By SEM, the HA was observed at the surface of inner pore in the porous coating. These results suggest that the method exhibits the potential to manufacture the bioactive ceramics on to porous-coated specimen to achieve bone ingrowth fixation for biomedical applications.


Assuntos
Substitutos Ósseos/química , Cerâmica/química , Materiais Revestidos Biocompatíveis/química , Durapatita/química , Titânio/química , Ligas , Carbonatos/química , Microscopia Eletrônica de Varredura , Tamanho da Partícula , Porosidade
18.
Theriogenology ; 67(3): 459-67, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17010414

RESUMO

Evidence suggests that exposure to excess steroids during critical periods of fetal development leads to reproductive disorders. Exposure of female lambs to excess testosterone (T) from Days 60 to 90 of gestation (T60-90; term, 147 days) delayed onset of the LH surge and resulted in to male-typical reproductive behavior. The objectives of this study were to test the ability of T60-90 ewes to mate, conceive and lamb during the first three breeding seasons (Years 1, 2 and 3). Pregnant Suffolk ewes were injected with T propionate in cottonseed oil (100mg, im twice weekly) or vehicle (control; C) from Days 60 to 90 of gestation. In Year 1, ewes (C=12, T60-90=12) were kept with a vasectomized ram for 3 months and markings/visual observation of copulations were recorded. Rams had paint applied to their chest to facilitate detection of estrus and mating. All C but only three T60-90 ewes were marked (P<0.001). All ewes were then estrus-synchronized with two injections of prostaglandin F2alpha (20mg, im) given 11 days apart and allowed to mate with a painted, fertile ram. Nine of 12 C and 4 of 12 T60-90 ewes (P=0.1) were mated. Based on estrus and long-term monitoring of progesterone, more C than T60-90 became pregnant (82 and 18%, respectively; P<0.01). In Year 2, to maximize ram exposure, two C and two T60-90 estrus-synchronized ewes were placed with a painted, fertile ram at a time and mated ewes were removed to a nearby pen to force mating with others. Twenty-four hour video monitoring revealed the rams mated more C than T60-90 ewes (83 and 25%, respectively; P=0.01). In both Years 1 and 2, the rams preferred C over T60-90 ewes; therefore in Year 3 rams were given access only to T60-90 ewes. Only four T60-90 estrus-synchronized ewes were placed with a painted ram at a time. Not given an option, 91% of the T60-90 ewes were marked resulting in 4 of 11 (36%; first-service pregnancy rate in the breeding herd was 91%) ewes becoming pregnant to the synchronized estrus. Collectively these studies showed that fertility in T60-90 females was severely compromised, even after overcoming ram preference for controls.


Assuntos
Cruzamento , Desenvolvimento Fetal/efeitos dos fármacos , Resultado da Gravidez/veterinária , Reprodução/efeitos dos fármacos , Ovinos/fisiologia , Testosterona/farmacologia , Animais , Animais Recém-Nascidos/crescimento & desenvolvimento , Estro/efeitos dos fármacos , Feminino , Masculino , Gravidez , Comportamento Sexual Animal/efeitos dos fármacos , Ovinos/embriologia , Testosterona/administração & dosagem , Fatores de Tempo
20.
Transl Psychiatry ; 7(7): e1175, 2017 07 25.
Artigo em Inglês | MEDLINE | ID: mdl-28742075

RESUMO

High psychopathy is characterized by untruthfulness and manipulativeness. However, existing evidence on higher propensity or capacity to lie among non-incarcerated high-psychopathic individuals is equivocal. Of particular importance, no research has investigated whether greater psychopathic tendency is associated with better 'trainability' of lying. An understanding of whether the neurobehavioral processes of lying are modifiable through practice offers significant theoretical and practical implications. By employing a longitudinal design involving university students with varying degrees of psychopathic traits, we successfully demonstrate that the performance speed of lying about face familiarity significantly improved following two sessions of practice, which occurred only among those with higher, but not lower, levels of psychopathic traits. Furthermore, this behavioural improvement associated with higher psychopathic tendency was predicted by a reduction in lying-related neural signals and by functional connectivity changes in the frontoparietal and cerebellum networks. Our findings provide novel and pivotal evidence suggesting that psychopathic traits are the key modulating factors of the plasticity of both behavioural and neural processes underpinning lying. These findings broadly support conceptualization of high-functioning individuals with higher psychopathic traits as having preserved, or arguably superior, functioning in neural networks implicated in cognitive executive processing, but deficiencies in affective neural processes, from a neuroplasticity perspective.


Assuntos
Transtorno da Personalidade Antissocial , Encéfalo/fisiologia , Enganação , Personalidade , Adulto , Transtorno da Personalidade Antissocial/fisiopatologia , Transtorno da Personalidade Antissocial/psicologia , Mapeamento Encefálico , Reconhecimento Facial , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Inventário de Personalidade , Tempo de Reação , Reconhecimento Psicológico , Adulto Jovem
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