Mitochondrial dysfunction associated with ascorbate synthesis in plants.

Mitochondria are the major organelles of energy production; however, active mitochondria can decline their energetic role and show a dysfunctional status. Mitochondrial dysfunction was induced by high non-physiological level of L-galactone-1,4-lactone (L-GalL), the precursor of ascorbate (AsA), in plant mitochondria. The dysfunction induced by L-GalL was associated with the fault in the mitochondrial electron partition and reactive oxygen species (ROS) over-production. Using mitochondria from RNAi-plant lines harbouring silenced L-galactone-1,4-lactone dehydrogenase (L-GalLDH) activity, it was demonstrated that such dysfunction is dependent on this enzyme activity. The capacity of alternative respiration was strongly decreased by L-GalL, probably mediated by redox-inactivation of the alternative oxidase (AOX) enzyme. Although, alternative respiration was shown to be the key factor that helps support AsA synthesis in dysfunctional mitochondria. Experiments with respiratory inhibitors showed that ROS formation and mitochondrial dysfunction were more associated with the decline in the activities of COX (cytochrome oxidase) and particularly AOX than with the lower activities of respiratory complexes I and III. The application of high L-GalL concentrations induced proteomic changes that indicated alterations in proteins related to oxidative stress and energetic status. However, supra-optimal L-GalL concentration was not deleterious for plants. Instead, the L-GalLDH activity could be positive. Indeed, it was found that wild type plants performed better growth than L-GalLDH-RNAi plants in response to high non-physiological L-GalL concentrations.

Monitoring of ammonia concentrations from coir-husk litter of Brazilian poultry house using diode laser photoacoustic spectroscopy.

Ammonia (NH[Formula: see text]) from manure is a concern in raising broiler due to possible damages to production and the environment. Brazil is the main exporter of chicken meat in the world and is also responsible for large waste of poultry litter. The country, likewise, figures as top 5 producers of green coconut, which results in considerable volumes of waste, since 80%-85% of the fruit is unusable. This work analyzes the ammonia concentration profile of two bedding substrates for raising broiler, to know, coir-husk fiber and a commonly used pine wood shavings in a Brazilian climate. A differential home-made photoacoustic cell combined with a diode laser was employed for sensing ammonia at trace levels. Such combination confers selectivity as well as lower limits of detection to the system. The chemical compositions pH, N, C, Ca, Mg, P[Formula: see text]O[Formula: see text] and K[Formula: see text]O were also determined, in addition to the moisture, dry matter and mineral content of substrates and litters. NH[Formula: see text] concentrations varied from (0.9 ± 0.3) ppmv to (19 ± 3) ppmv and from (2.1 ± 0.5) ppmv to (21 ± 3) ppmv for the coir-husk fiber and wood shavings substrates, respectively. Results showed the feasibility of using coconut fiber as poultry litter in regions where this material is a common waste. Moreover, as NH[Formula: see text] concentrations were lower for coconut fiber bedding compared to shavings, this coir-husk fiber is a potential residue to guarantee the environmental sustainability by Brazilian poultry farming. Coir-husk fibers presented significantly higher amounts of P and K in comparison to pine wood. NH[Formula: see text] profiles revealed that coir-husk fiber emitted lower quantities than wood shavings. Besides, a delay on the NH[Formula: see text] emission pattern was clearly seen when the coconut waste was the bedding material. Such a tendency was confirmed by the logistic model. Our findings, in turn, make the coir-husk an environmentally friendly alternative low-cost product for poultry litter as well as its potential use as natural fertilizer. The later deserves attention since there is a need to accurately assess the emissions of methane, nitrous oxide, and carbon dioxide during the composting process. In Brazil, the waste generated by the high production of green coconut is an environmental liability. The cost of poultry production has been high, reducing the profit of producers, who seek to make production cheaper. Measuring NH[Formula: see text] from poultry activity in Brazil, a tropical country, aims to control management and reduce production losses, since NH[Formula: see text] is a harmful gas to birds. The measurement of NH[Formula: see text] concentrations at trace levels from raising broilers by photoacoustic diode laser spectroscopy, to the best of our knowledge, has been reported for the very first time.

Photoacoustic detection of ammonia exhaled by individuals with chronic kidney disease.

Ammonia (NH3) has been reported as a breath biomarker for chronic kidney disease (CKD) usually detected at concentrations greater than 0.25 parts per million by volume (ppmV). NH3 was detected in breath of individuals with CKD through gaseous photoacoustic spectroscopy (PAS). The efficiency of hemodialysis (HD) was demonstrated. Eight volunteers aged between 20 and 60 years and without previous respiratory disease were eligible, among which six were control volunteers (CV) and two volunteers with advanced CKD, named CKDV1 and CKDV2. The presence of CKD was confirmed by the calculation of creatinine clearance (CC) according to the Cockcroft-Gault equation. Before HD, the mean NH3 concentration exhaled by CKDV1 was 0.9 ± 0.1 ppmV and after HD was 0.20 ± 0.03 ppmV, which demonstrated an efficiency of 76% NH3 reduction in breath. The CKDV2 exhaled 1.27 ± 0.03 ppmV of NH3 pre-HD and 0.42 ± 0.08 ppmV post-HD, which resulted in efficiency of about 67%. It was not possible to quantify NH3 from CV, what led us to infer that all of them exhaled amounts below the detection limit, i.e., 0.20 ppmV. This assumption is underpinned by CC, whose values hovered at 90 ≤ CC ≤ 120 mL/ min, confirming normal renal function.

Environmental impact of combustion of ethanolic biodiesel/diesel blends from several feedstocks on the gas emission levels in the atmosphere.

The aim of this work was to evaluate simultaneously the effect of produced ethanolic biodiesel from several feedstocks (soybean, crambe, macaw, sunflower, and waste cooking oil) and engine operational conditions (low and high engine speed) during combustion of biodiesel/diesel blends on the N2O, NOx, NO, CO2, and CO emission levels in the atmosphere. The biodiesel samples were prepared in one and/or two reaction steps, according to the acid index of each raw material, by esterification using H2SO4 and/or chemical transesterification using sodium ethoxide, both, through ethanolic route. The quality of the produced biodiesels was confirmed by ASTM/EN specifications. Then, biodiesel/diesel blends were prepared according to the following proportions: 10% (B10), 15% (B15), 25% (B25), and 50% (B50). In general way, all raw materials under combustion at low and high engine speed contributed to the formation of NOx and this effect was more drastically increased as the biodiesel concentration in the blends increases. N2O presented a similar behavior except for blends containing crambe and macaw biodiesel whose emissions were slightly reduced as a function of biodiesel content in these blends. Then, Principal component analysis (PCA) was applied to discriminate the effect of engine operating conditions, biodiesel kind, and biodiesel content in the blends during their combustion on the exhaust emissions. The attained results point to crambe and macaw as more environmentally sustainable feedstocks for biodiesel production because they generate less greenhouse gas emissions. These results are particularly attractive considering that, both, crambe and macaw are non-edible feedstocks with great potential for biodiesel production.

Temporomandibular disorders and relationship with socio-demographic and clinical variables in a University of the state of Rio de Janeiro / Disfunções temporomandibulares e a relação com determinantes sócio-demográficos e clínicos em uma universidade do estado do Rio de Janeiro

ABSTRACT BACKGROUND AND OBJECTIVES: This study aimed at identifying the prevalence of suspected temporomandibular disorders in employees and students of a Brazilian university and at evaluating the influence of socio-demographic and clinical variables on this disorder. METHODS: This study had a non-probabilistic sample of 575 volunteers who were evaluated by a questionnaire proposed by the American Academy of Orofacial Pain. RESULTS: Suspected temporomandibular disorder was present in 60.87% of the population. By means of multiple logistic regression analysis, just clinical variables were associated to the presence of suspected temporomandibular disorder, such as: headache, neck pain or teethache (OR=47.60), stiff, tight or regularly tired jaws (OR=13.37), mouth opening difficulty (OR=13.55) and pain around the ears, temples or cheeks (OR=4.61). CONCLUSION: The questionnaire was effective as a pre-screening tool to identify symptoms, and results support the importance of clinical symptoms for the identification and follow up of patients with such disorders.

RESUMO JUSTIFICATIVA E OBJETIVOS: O objetivo deste estudo foi identificar a prevalência de suspeita de disfunção temporomandibular em funcionários e estudantes em uma universidade no Brasil e analisar a influência das variáveis sócio-demográficas e clínicas sobre essa disfunção. MÉTODOS: Este estudo teve uma amostra não probabilística compreendendo 575 voluntários que foram avaliadas por um questionário, proposto pela Academia Americana de Dor Orofacial. RESULTADOS: A suspeita de disfunção temporomandibular estava presente em 60,87% da população. Por meio da análise de regressão logística múltipla, apenas variáveis clínicas foram associadas com a presença de suspeita de disfunção temporomandibular, como: apresentar cefaleia, dores no pescoço ou nos dentes (OR=47,60), maxilares rígidos, apertados ou cansados com regularidade (OR=13,37), dificuldade na abertura da boca (OR=13,55) e dor ao redor das orelhas, têmporas ou bochecha (OR=4,61). CONCLUSÃO: O questionário foi eficaz como um instrumento de pré-triagem no levantamento dos sintomas; e os resultados suportam o ponto forte dos sintomas clínicos na identificação e acompanhamento de indivíduos com tais lesões.

Photodegradation of ethylene by use of TiO2 sol-gel on polypropylene and on glass for application in the postharvest of papaya fruit.

The papaya is a commercially important fruit commodity worldwide. Being a climacteric fruit, it is highly perishable. Thus, for the transportation of papaya fruit for long distances without loss of quality, it is necessary to avoid the autocatalytic effect of ethylene in accelerating the ripening of the fruit. This work addresses the application of heterogeneous photocatalysis to the degradation of ethylene. A TiO2 sol-gel supported on polypropylene (PP) and on glass was used as the catalytic material, and a UV-A lamp was employed as the radiation source. Initially, a concentration of 500 ppbv ethylene was exposed to the catalyst material irradiated by UV-A radiation. A sensitive photoacoustic spectrometer was used to monitor the photocatalytic activity. The TiO2 sol-gel supported on the glass substrate was more efficient than on the PP in degrading the ethylene. Under direct UV-A exposure, the skin appearance of 'Golden' papaya was damaged, depreciating the fruit quality and thus preventing its commercialization. However, the feasibility of the heterogeneous photocatalysis to preserve the fruit quality was achieved when ethylene was removed from the storage ambient using fans, and then, this plant hormone was degraded by a reactor set apart in a ventilation closed system.

Distribuição de tensões em próteses parciais fixas posteriores livres de metal com retentores intracoronários: análise em elementos finitos / Stress distribution in metal-free posterior inlay-retained fixed partial dentures: finite element analysis

Para reabilitar a ausência de um elemento dentário posterior, as próteses parciais fixas (PPF) com retentores intracoronários são uma alternativa aos implantes osseointegrados. O objetivo deste estudo foi avaliar a distribuição de tensões nessas próteses com três combinações de materiais: cerâmica de zircônia parcialmente estabilizada por ítria (ZPEI) revestida por cerâmica de fluorapatita (α), cerâmica de dissilicato de lítio (β) ou compósito fibrorreforçado (γ). Na composição α, foram analisadas a presença ou ausência da cerâmica de revestimento na parede cervical das caixas proximais e três variações na área total da seção transversal dos conectores (4 mm de largura x 3,2, 4,2 ou 5,2 mm de altura). Em 8 modelos bidimensionais de elementos finitos, uma carga vertical de 500 N foi aplicada na fossa central do pôntico e as tensões principais máximas (tração) e mínimas (compressão) foram apontadas em MPa. Inicialmente foram avaliados os 6 modelos com PPF de ZPEI e suas variações. Os maiores valores das tensões de tração foram encontrados no terço cervical dos conectores. Quando presente nestas regiões, a cerâmica de revestimento recebeu tensões acima do limite de sua resistência à flexão. Na comparação entre os modelos sem cerâmica de revestimento na parede cervical das caixas proximais, mesmo aquele com conectores de 3,2 x 4 mm, cuja infraestrutura apresentava 2,5 x 3 mm, poderia ser recomendado para uso clínico. Altos valores de tensões de compressão foram registrados entre o terço oclusal e médio dos conectores, correspondente à união entre as cerâmicas, o que poderia ocasionar, devido à flexão, falhas adesivas. Posteriormente, o modelo de ZPEI com a cerâmica de fluorapatita ausente da parede cervical das caixas proximais e área total dos conectores de 4,2 x 4 mm foi comparado aos dois outros materiais com conectores de mesma área. Na PPF de dissilicato de lítio, os valores representaram uma provável violação do limite de sua resistência à flexão...

Inlay-retained fixed partial dentures (IRFPD) are an alternative to osseointegrated implants to replace a single missing posterior tooth. The aim of this study was to evaluate the stress distribution within these prostheses with three material combinations: yttria-tetragonal zirconia polycrystal (Y-TZP) ceramic veneered with fluorapatite ceramic (α), lithium-disilicate ceramic (β) or fiber-reinforced composite (γ). In composition α, an analysis was conducted on the presence or absence of the veneering ceramic on the cervical wall of the proximal boxes and three variations in the total area of the connectors’ cross-section (4 mm in width x 3.2, 4.2 or 5.2 mm in height). In 8 two-dimensional finite element models, a vertical load of 500 N was applied on the central fossa of the pontic. Maximum (tension) and minimum (compression) principal stresses were then shown in MPa. First, the 6 models with Y-TZP fixed partial dentures (FPD) and their variations were evaluated. The highest values of tensile stresses were found at the cervical third of the connectors. When present in these regions, the veneering ceramic received stresses beyond its flexural strength limit. In the comparison among models without veneering ceramic on the cervical wall of the proximal boxes, even the model with connectors of 3.2 x 4 mm, whose framework presented 2.5 x 3 mm, could be recommended for clinical use. High values of compressive stresses were recorded between the middle and occlusal thirds of the connectors, corresponding to the juncture of the ceramics. Owing to flexure, these stresses might lead to adhesive failures. Then, the Y-TZP model without fluorapatite ceramic on the cervical wall of the proximal boxes and total connector area of 4.2 x 4 mm was compared to the other two materials with connectors of the same area. For the lithium-disilicate FPD, the observed values would probably exceed its flexural strength limit...

Distribuição de tensões em próteses parciais fixas posteriores livres de metal com retentores intracoronários: análise em elementos finitos / Stress distribution in metal-free posterior inlay-retained fixed partial dentures: finite element analysis

Para reabilitar a ausência de um elemento dentário posterior, as próteses parciais fixas (PPF) com retentores intracoronários são uma alternativa aos implantes osseointegrados. O objetivo deste estudo foi avaliar a distribuição de tensões nessas próteses com três combinações de materiais: cerâmica de zircônia parcialmente estabilizada por ítria (ZPEI) revestida por cerâmica de fluorapatita (α), cerâmica de dissilicato de lítio (β) ou compósito fibrorreforçado (γ). Na composição α, foram analisadas a presença ou ausência da cerâmica de revestimento na parede cervical das caixas proximais e três variações na área total da seção transversal dos conectores (4 mm de largura x 3,2, 4,2 ou 5,2 mm de altura). Em 8 modelos bidimensionais de elementos finitos, uma carga vertical de 500 N foi aplicada na fossa central do pôntico e as tensões principais máximas (tração) e mínimas (compressão) foram apontadas em MPa. Inicialmente foram avaliados os 6 modelos com PPF de ZPEI e suas variações. Os maiores valores das tensões de tração foram encontrados no terço cervical dos conectores. Quando presente nestas regiões, a cerâmica de revestimento recebeu tensões acima do limite de sua resistência à flexão. Na comparação entre os modelos sem cerâmica de revestimento na parede cervical das caixas proximais, mesmo aquele com conectores de 3,2 x 4 mm, cuja infraestrutura apresentava 2,5 x 3 mm, poderia ser recomendado para uso clínico. Altos valores de tensões de compressão foram registrados entre o terço oclusal e médio dos conectores, correspondente à união entre as cerâmicas, o que poderia ocasionar, devido à flexão, falhas adesivas. Posteriormente, o modelo de ZPEI com a cerâmica de fluorapatita ausente da parede cervical das caixas proximais e área total dos conectores de 4,2 x 4 mm foi comparado aos dois outros materiais com conectores de mesma área. Na PPF de dissilicato de lítio, os valores representaram uma provável violação do limite de sua resistência à flexão...

Inlay-retained fixed partial dentures (IRFPD) are an alternative to osseointegrated implants to replace a single missing posterior tooth. The aim of this study was to evaluate the stress distribution within these prostheses with three material combinations: yttria-tetragonal zirconia polycrystal (Y-TZP) ceramic veneered with fluorapatite ceramic (α), lithium-disilicate ceramic (β) or fiber-reinforced composite (γ). In composition α, an analysis was conducted on the presence or absence of the veneering ceramic on the cervical wall of the proximal boxes and three variations in the total area of the connectors’ cross-section (4 mm in width x 3.2, 4.2 or 5.2 mm in height). In 8 two-dimensional finite element models, a vertical load of 500 N was applied on the central fossa of the pontic. Maximum (tension) and minimum (compression) principal stresses were then shown in MPa. First, the 6 models with Y-TZP fixed partial dentures (FPD) and their variations were evaluated. The highest values of tensile stresses were found at the cervical third of the connectors. When present in these regions, the veneering ceramic received stresses beyond its flexural strength limit. In the comparison among models without veneering ceramic on the cervical wall of the proximal boxes, even the model with connectors of 3.2 x 4 mm, whose framework presented 2.5 x 3 mm, could be recommended for clinical use. High values of compressive stresses were recorded between the middle and occlusal thirds of the connectors, corresponding to the juncture of the ceramics. Owing to flexure, these stresses might lead to adhesive failures. Then, the Y-TZP model without fluorapatite ceramic on the cervical wall of the proximal boxes and total connector area of 4.2 x 4 mm was compared to the other two materials with connectors of the same area. For the lithium-disilicate FPD, the observed values would probably exceed its flexural strength limit...

Prótese parcial removível com eixo de inserção rotacional: relato de caso / Rotational path removable partial denture: case report

Este relato de caso apresenta os benefícios estéticos da prótese parcial removível com eixo de inserção rotacional diante dos desafios e limitações característicos dessas reabilitações protéticas. O paciente queixava-se de instabilidade e pouca retenção de suas próteses parciais removíveis, além da má aparência de seu sorriso, comprometido pela exposição de uma porção metálica da estrutura superior e pela fratura do elemento protético 22. Para este arco, a prótese rotacional confeccionada possibilitou a colocação de componentes rígidos da estrutura metálica em regiões retentivas nas mesiais dos caninos, prescindindo dos braços de retenção vestibular nestes locais. Os autores pretendem contribuir para a difusão da técnica, que exige elevado apuro clínico e laboratorial, mas propicia resultados estéticos satisfatórios.

Disfunção craniomandibular em portador de prótese total dupla - relato de caso clínico / Craniomandibular dysfunction in complete denture wearer - case report

Este artigo faz o relato de um caso clínico de Disfunção Craniomandibular (DCM) em indivíduo do sexo feminino, 65 anos e portador de prótese total dupla. A paciente apresentou-se à clínica de Especialização em Prótese Dentária da Universidade Veiga de Almeida para confecção de novas próteses. Ao exame clínico, suspeitou-se de DCM e o diagnóstico foi confirmado pela avaliação do índice clínico e anamnésico modificado por Helkimo para disfunção. O tratamento foi efetuado devolvendo as características ideais de retenção, estabilidade, suporte e oclusão para prótese total e a redução da sintomatologia foi obtida dias após a entrega

Histological and biochemical serum effects of alpha-tocopherol on ischemia/reperfusion-related injuries induced in the pelvic limb of rats

OBJETIVO: Avaliar ação protetora do alfa-tocoferol na lesão de isquemia e reperfusão em membro pélvico de ratos. MÉTODOS: Trinta ratos machos adultos da linhagem wistar foram distribuídos aleatoriamente, em três grupos experimentais, com 10 animais cada: Grupo I – Grupo controle sem isquemia ou reperfusão. Grupos II e III – quatro horas de isquemia e duas horas de reperfusão através clampeamento da aorta infra-renal. Os animais do grupo II foram tratados com solução salina e aqueles do grupo III, tratados com alfa-tocoferol 50 mg/kg por via endovenosa. Parâmetros estudados: Biópsias do músculo solear, dosagens da creatina fosfoquinase, da desidrogenasse láctica, do potássio, do cálcio e da hemogasometria arterial. RESULTADOS: Os resultados das biópsias dos músculos soleares estudados através da microscopia óptica, não foram significantes quanto a presença de edema entre os três grupos estudados. As variáveis inflamação e necrose não foram observadas e, portanto não analisáveis estatisticamente. Em relação às dosagens de cálcio e desidrogenase lática, pH, pO2, pCO2, não foram significantes em todos os grupos estudados. Observamos que os níveis de potássio (Grupo II > grupo I, F calculado = 5,84; F crítico = 3,33), creatina fosfoquinase (Grupo II > Grupo I e III, H calculado =13,92; Hcritico 5,99) , e bicarbonato (grupo I e III > grupo II, H calculado = 11,98; h critico 5.99 ) apresentaram resultados significantes entre os grupos. CONCLUSÃO: Tratamento com alfa-tocoferol do ponto de vista bioquímico sérico atenuou as lesões metabólicas na síndrome de isquemia e reperfusão neste modelo experimental.

Histological and biochemical serum effects of alpha-tocopherol on ischemia/reperfusion-related injuries induced in the pelvic limb of rats.

PURPOSE: To evaluate the protective action of alpha-tocopherol in ischemia/reperfusion injuries of pelvic member of rats. METHODS: Thirty adult male rats of the Wistar strain were randomized into three experimental groups of 10: Group I--control group with no ischemia or reperfusion. Groups II and III--four hours of ischemia and of hours of reperfusion by means of clamping of the infrarenal aorta. The animals of Group II were treated with saline and those of Group III were treated with i.v. alpha-tocopherol (50 mg/kg). Parameters studied were biopsies of the soleus muscle, dosing of creatine phosphokinase, lactate dehydrogenase, potassium, calcium and arterial blood gasometry. RESULTS: The results of biopsies of the soleus muscles studied by optical microscopy, were not significant in terms of presence of edema among the three groups studied. Variables inflammation and necrosis were not observed, therefore cannot be statistically analyzed. As to dosing of calcium and lactate dehydrogenase, the pH, pO2 and pCO2 values were not significant for all groups studied. We observed that the levels of potassium (Group II > Group I, Fcalculated = 5.84; Fcritical = 3.33), creatine phosphokinase (Group II > Groups I and III, Hcalculated = 13.92; Hcritical = 5.99) and bicarbonate (Groups I and III > Group II, Hcalculated = 11.98; Hcritical = 5.99) presented significant results among groups. CONCLUSION: From the serum biochemical perspective, the treatment with alpha-tocopherol has attenuated the metabolic injuries in the ischemia/reperfusion syndrome in this experimental model.

Influência da esplintagem de restaurações protéticas fixas sobre implantes na distribuição de tensões em mandíbula edentada posterior / Influence of the splinting of implant-supported fixed restorations on stress distribution in posterior edentulous mandible

Este estudo teve como finalidade analisar a influência da esplintagem de restaurações protéticas fixas na distribuição das tensões de von Mises em dois modelos matemáticos bidimensionais obtidos pelo método de elementos finitos. O limite de proporcionalidade dos materiais e estruturas analisadas não foi alcançado nos dois modelos, de modo que nenhuma das configurações estudadas foi contra-indicada. Entretanto, os resultados sugeriram que o planejamento do tratamento deve ser adequado a condições anatômicas oclusais e biomecânicas específicas.