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1.
Nutr Neurosci ; 27(3): 212-222, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36809120

RESUMO

ABSTRACTThe brain aging process triggers cognitive function impairment, such as memory loss and compromised quality of life. Cognitive impairment is based on bioenergetic status, with reduced glucose uptake and metabolism in aged brains. Anaplerotic substrates are reported to promote mitochondrial ATP generation, having been tested in clinical trials for the treatment of neurological disorders and metabolic diseases.Objectives and Methods: To assess whether the improvement in oxidative capacity ameliorates cognitive function in adults (12 weeks), and aged (22-month-old) C57/6BJ mice, they received (1) a ketogenic diet, (2) a ketogenic diet supplemented with the anaplerotic substance, triheptanoin, or (3) a control diet for 12 weeks. Spontaneous alternation and time spent in a previously closed arm in the Y-maze test and time interacting with an unknown object in the novel object recognition test (NORT) were used to evaluate working memory. Acetylcholinesterase (AChE) activity in the prefrontal lobe, brain left hemisphere, and cerebellum was also evaluated. Glucose transporter 3 (GLUT3) expression in the prefrontal lobe was analyzed by western blotting.Results: The ketogenic diet (KD) reduced spontaneous alternation in aged mice, leading to lower AChE activity in the aged prefrontal lobe and cerebellum, and in the parieto-temporal-occipital lobe of adult mice. Furthermore, KD decreased GLUT3 protein expression in the frontal lobe of the adults.Discussion: Supplementation of KD with triheptanoin prevented memory impairment and showed similar values of AChE activity and GLUT3 expression compared to the controls. Our data suggest that triheptanoin has a potential role in the bioenergetic capacity of the brain, improving cognitive function.


Assuntos
Acetilcolinesterase , Qualidade de Vida , Camundongos , Animais , Transportador de Glucose Tipo 3/metabolismo , Acetilcolinesterase/metabolismo , Triglicerídeos , Encéfalo/metabolismo , Cognição
2.
Br Poult Sci ; 64(1): 137-141, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36129037

RESUMO

1. This study evaluated the minimal inhibitory concentration (MIC) of ciprofloxacin and the presence of plasmid-mediated quinolone resistance (PMQR) mechanisms in 97 nontyphoidal Salmonella spp. isolated from broilers and carcases from three different regions in Brazil. The presence of mutations in quinolone resistance determination regions (QRDRS) was investigated in the ciprofloxacin-resistant strain by DNA sequencing.2. Most of the Salmonella spp. (85.6%) had intermediate resistance to ciprofloxacin and only one isolate was resistant. MIC breakpoints ranged from ≤0.03 to 1 µg/ml and 67.0% of the strains had a MIC of 0.25 µg/ml (n=65). Thirteen strains (13.4%) were susceptible to ciprofloxacin with MIC ≤0.06 µg/ml. The qnrB gene was detected in eight isolates with intermediate resistance and in two susceptible strains. The other PMQR genes, qnrA, qnrC, qnrD, qnrS, qnrVC, aac(6')-Ib, qepA, oqxAB and mutations in QRDR were not detected in any strain.3. There was a high frequency of ciprofloxacin intermediate resistant Salmonella from broiler and broiler carcases from Brazil. The presence of these strains in poultry and derived products poses a risk to public health.


Assuntos
Ciprofloxacina , Quinolonas , Animais , Ciprofloxacina/farmacologia , Galinhas , Brasil , Proteínas de Bactérias/genética , Salmonella , Quinolonas/farmacologia , Testes de Sensibilidade Microbiana/veterinária , Antibacterianos/farmacologia , Farmacorresistência Bacteriana/genética
3.
Dermatol Online J ; 28(4)2022 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-36259866

RESUMO

Mohs micrographic surgery (MMS) is a surgical technique used to remove skin tumors with a complete evaluation of the margins. The keystone flap technique is generally used to repair large surgical defects on limbs. We present a case where a modified keystone flap technique was used to close a large defect after Mohs micrographic surgery in a patient with a basal cell carcinoma on the nose. An excellent functional and aesthetic result was obtained with no complications during or after the procedure. We offer a novel indication for this technique for surgical defects in this area.


Assuntos
Carcinoma Basocelular , Neoplasias Nasais , Procedimentos de Cirurgia Plástica , Humanos , Carcinoma Basocelular/cirurgia , Cirurgia de Mohs/efeitos adversos , Neoplasias Nasais/cirurgia , Retalhos Cirúrgicos/cirurgia , Procedimentos de Cirurgia Plástica/métodos
4.
Fish Physiol Biochem ; 47(2): 239-249, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33405064

RESUMO

Although silver nanoparticles (AgNP) are among the most studied nanomaterials by virtue of their broad application in many areas, little is known about their overall toxicity to aquatic organisms after their contamination of the water environment. This study aimed to analyze the effect of the exposure (96 h) to different AgNP concentrations on Danio rerio (zebrafish) tissues. AgNP were synthesized and characterized by transmission electron microscopy (TEM), showing spherical AgNP of 30.00 ± 16.80 nm size. The effects of different AgNP concentrations (1, 3, and 5 µg L-1) on brain, muscle, gill, and liver tissues of zebrafish were investigated. The results show a significant decrease in brain and muscle acetylcholinesterase (AChE) activity. Liver and gill catalase (CAT) activity also decreased significantly. At the highest exposure concentration, muscle AChE was more inhibited (37.3%) than brain AChE (26.4%) and gill CAT was more inhibited (67.4%) than liver CAT (51.2%). D. rerio also showed gill morphological changes such as fusion of secondary lamellae, curvature, dilated marginal channel, and epithelial lifting. This study indicates that gill CAT together with morphological studies are potential biomarkers for AgNP.


Assuntos
Encéfalo/efeitos dos fármacos , Brânquias/efeitos dos fármacos , Fígado/efeitos dos fármacos , Nanopartículas Metálicas/toxicidade , Músculo Esquelético/efeitos dos fármacos , Prata/toxicidade , Animais , Nanopartículas Metálicas/química , Prata/química , Distribuição Tecidual , Testes de Toxicidade , Peixe-Zebra
5.
J Appl Microbiol ; 126(5): 1426-1437, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30762925

RESUMO

AIMS: The aim of this study was to find new eukaryotic sources of the l-asparaginase (l-ASNase), since the prokaryotic sources of the enzyme are well-reported as causing allergic hypersensitivity reactions in a significant number of patients. This report describes screening for l-ASNase production by filamentous fungi isolated from the Brazilian Caatinga, and the optimization of fermentation parameters to increase fungal growth and improve yield in the production of l-ASNase. METHODS AND RESULTS: Thirty-two filamentous fungi were investigated in this study. When Aspergillus terreus strain S-18 was cultured in a proline-enriched medium, intracellular l-ASNase was expressed in concurrence with reduced l-glutaminase (l-GLUase) and protease activities. Fermentation conditions were then optimized in a 5-l bioreactor system to produce a maximum volumetric yield of 108 U total of l-ASNase activity. CONCLUSIONS: The work reported here represents the first attempt to produce l-ASNase by filamentous fungi isolated from Brazil and offers a promising alternative eukaryotic source for l-ASNase production. SIGNIFICANCE AND IMPACT OF THE STUDY: In order to minimize the side effects caused by bacterial l-ASNase, the search of eukaryotic micro-organism for l-ASNase was carried out in fungi. This study demonstrates the diversity of filamentous fungi isolated from the Brazilian Caatinga Biome and the importance of knowledge of the microbial metabolism to obtain high concentrations of biotechnological products.


Assuntos
Asparaginase , Aspergillus , Reatores Biológicos/microbiologia , Asparaginase/análise , Asparaginase/metabolismo , Aspergillus/química , Aspergillus/enzimologia , Aspergillus/metabolismo , Brasil , Microbiologia Ambiental , Fermentação , Florestas , Microbiota
6.
Biochim Biophys Acta ; 1863(6 Pt A): 1119-33, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26947915

RESUMO

The skin possesses a photosensitive system comprised of opsins whose function is not fully understood, and clock genes which exert an important regulatory role in skin biology. Here, we evaluated the presence of opsins in normal (Melan-a cells) and malignant (B16-F10 cells) murine melanocytes. Both cell lines express Opn2, Opn4--for the first time reported in these cell types--as well as S-opsin. OPN4 protein was found in a small area capping the cell nuclei of B16-F10 cells kept in constant dark (DD); twenty-four hours after the white light pulse (WLP), OPN4 was found in the cell membrane. Despite the fact that B16-F10 cells expressed less Opn2 and Opn4 than Melan-a cells, our data indicate that the malignant melanocytes exhibited increased photoresponsiveness. The clock gene machinery is also severely downregulated in B16-F10 cells as compared to Melan-a cells. Per1, Per2, and Bmal1 expression increased in B16-F10 cells in response to WLP. Although no response in clock gene expression to WLP was observed in Melan-a cells, gene correlational data suggest a minor effect of WLP. In contrast to opsins and clock genes, melanogenesis is significantly upregulated in malignant melanocytes in comparison to Melan-a cells. Tyrosinase expression increased after WLP only in B16-F10 cells; however no increase in melanin content after WLP was seen in either cell line. Our findings may prove useful in the treatment and the development of new pharmacological approaches of depigmentation diseases and skin cancer.


Assuntos
Expressão Gênica/efeitos da radiação , Luz , Melaninas/biossíntese , Melanócitos/efeitos da radiação , Animais , Proteínas CLOCK/genética , Proteínas CLOCK/metabolismo , Linhagem Celular , Linhagem Celular Tumoral , Imuno-Histoquímica , Melanócitos/metabolismo , Melanoma/genética , Melanoma/metabolismo , Melanoma/patologia , Camundongos , Microscopia de Fluorescência , Monofenol Mono-Oxigenase/genética , Monofenol Mono-Oxigenase/metabolismo , Opsinas/genética , Opsinas/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Tempo
7.
J Intellect Disabil Res ; 61(8): 755-765, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28585394

RESUMO

BACKGROUND: People with Down syndrome (DS) usually display reduced physical fitness (aerobic capacity, muscle strength and abnormal body composition), motor proficiency impairments (balance and postural control) and physical functional limitations. Exergames can be an appealing alternative to enhance exercise engagement and compliance, whilst improving physical fitness and motor function. This study aims to analyse the effects of a Wii-based exercise program on physical fitness, functional mobility and motor proficiency of adults with DS. METHODS: Twenty-seven adults with DS were randomly allocated to an experimental group (Wii; n = 14) or control group (n = 13). Participants in the experimental group completed a 2-month Wii-based exercise program, with three 1-h sessions per week that included training games for aerobic endurance, balance and isometric strength. Participants completed assessments regarding anthropometric measures, physical fitness, functional mobility and motor proficiency. RESULTS: Mixed ANOVA analysis showed a significant group by time interaction for aerobic endurance, explosive leg power and flexibility. Independent samples t-test for change scores indicated significant between-group differences favouring the experimental group regarding speed of limb movement, trunk strength and functional mobility, as well as a trend towards significance on body weight. Mann-Whitney's U test for change scores demonstrated between-group differences favouring the experimental group for visceral fat as well as running speed and agility. Large within-group effect sizes were observed for explosive leg power (d = 1.691), body weight (d = 1.281), functional mobility (d = 1.218), aerobic endurance (d = 1.020), speed of limb movement (d = 0.867) and flexibility (d = 0.818) in the experimental group. CONCLUSIONS: Our findings suggest that Wii-based exercise can be an effective tool to improve physical fitness, functional mobility and motor proficiency of adults with DS, including crucial measures such as aerobic capacity and lower limb strength. Exergames using Wii Fit or other equipment can be appealing alternatives for adults with DS to engage in regular physical activity, preventing sedentary behaviour and decreasing the risk to develop cardiovascular diseases.


Assuntos
Síndrome de Down/reabilitação , Terapia por Exercício/métodos , Avaliação de Resultados em Cuidados de Saúde , Terapia Assistida por Computador/métodos , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Jogos de Vídeo
8.
Int J Colorectal Dis ; 31(2): 197-210, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26507962

RESUMO

PURPOSE: To obtain a prognostic index, which has been named PROCOLE (prognostic colorectal leakage), it can predict the risk that a certain individual may suffer anastomotic leakage. METHODS: The methodology consists of a systematic review to identify potential risk factors for anastomotic leakage and a meta-analysis of studies of each of these factors. In the meta-analysis, the prognostic index integrates factors that are statistically significant, which are weighted according to the estimated value of the effect size. The prognostic index was validated using retrospectively collected data from patients who underwent colorectal cancer surgery anastomosis at our institution. RESULTS: The mean and standard deviation of the PROCOLE prognostic index in patients with anastomotic leakage is 1.9 ± 6.13, whereas in controls, it is 3.63 ± 2.1. The predictive ability of the PROCOLE, assessed by calculating the area under the curve (AUC) of the receiver operating characteristic (ROC), results in an AUC of 0.82 with a 95% confidence interval (CI) (0.75, 0.89) of the AUC, and it can be considered a good prognostic indicator. CONCLUSIONS: The PROCOLE prognostic index predicts the risk of a certain individual developing anastomotic leakage after colorectal cancer surgery. Specifically, the PROCOLE prognostic index establishes a discrimination value threshold of 4.83 for recommending the implementation of a protective stoma. We have developed free software with a simple interface that only requires the selection of risk factors to obtain the PROCOLE value.


Assuntos
Fístula Anastomótica/etiologia , Colo/cirurgia , Neoplasias Colorretais/cirurgia , Reto/cirurgia , Humanos , Estudos Observacionais como Assunto , Prognóstico , Fatores de Risco
9.
Genet Mol Res ; 15(3)2016 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-27525952

RESUMO

The pteridophytes Salvinia minima, S. herzogii, and S. auriculata are among the most abundant aquatic macrophytes in the upper Paraná River floodplain. Since some species have highly similar morphological features, it is very difficult to identify members of this genus to the species level. An indication of this difficulty is a set of poorly differentiated taxa comprising S. auriculata and S. herzogii known as the 'S. auriculata complex', which is found in the Paraná River together with other Salvinia species such as S. biloba and S. molesta. Some authors have reported the existence of inter-species hybrids. Despite the complex Salvinia taxonomy, few genetic studies have been performed on purported species within the genus to resolve this complexity. The present study was conducted to determine useful molecular sequences for the discrimination of Salvinia species of the upper Paraná River floodplain. Molecular data were compared with data of other species of the genus to clarify phylogenetic relationships, employing the nucleotide sequence trnL-trnF from the chloroplast DNA. The results revealed that Salvinia populations in the upper Paraná River floodplain belong to different species and indicated that species of the S. auriculata complex may be distinguished from one another after the division of the S. minima group, corroborating results by other researchers. Although the taxonomic position of S. oblongifolia was clarified, as high closeness between S. oblongifolia and the S. auriculata complex was reported, Salvinia kinship is still not thoroughly established and further investigations in morphology and molecular diversity are required.


Assuntos
Traqueófitas/genética , Biodiversidade , DNA de Cloroplastos/genética , Genes de Plantas , Tipagem Molecular , Filogenia , Rios , Análise de Sequência de DNA
10.
Scand J Med Sci Sports ; 23(1): 46-56, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21672029

RESUMO

We investigated brain mechanisms modulating fatigue during prolonged physical exercise in cold environments. In a first set of studies, each rat was subjected to three running trials in different ambient temperatures (T(a)). At 8 °C and 15 °C, core body temperature (T(core)) decreased and increased, respectively, whereas at 12 °C, the T(core) did not change throughout the exercise. In another set of experiments, rats were randomly assigned to receive bilateral 0.2 µL injections of 2.5 × 10(-2) M methylatropine or 0.15 M NaCl solution into the ventromedial hypothalamic nuclei (VMH). Immediately after the injections, treadmill exercise was started. Each animal was subjected to two experimental trials at one of the following T(a) : 5 °C, 12 °C or 15 °C. Muscarinic blockade of the VMH reduced the time to fatigue (TF) in cold environments by 35-37%. In all T(a) studied, methylatropine-treated rats did not present alterations in T(core) and tail skin temperature compared with controls. These results indicate that, below the zone of thermoneutrality, muscarinic blockade of the VMH decreases the TF, independent of changes in T(core). In conclusion, our data suggest that VMH muscarinic transmission modulates physical performance, even when the effects of thermoregulatory adjustments on fatigue are minimal.


Assuntos
Regulação da Temperatura Corporal/efeitos dos fármacos , Temperatura Baixa , Hipotálamo Médio/efeitos dos fármacos , Esforço Físico/efeitos dos fármacos , Receptores Muscarínicos/fisiologia , Animais , Regulação da Temperatura Corporal/fisiologia , Hipotálamo Médio/fisiologia , Masculino , Fadiga Muscular/efeitos dos fármacos , Esforço Físico/fisiologia , Ratos , Ratos Wistar , Receptores Muscarínicos/administração & dosagem , Corrida/fisiologia
11.
Minerva Stomatol ; 62(5): 189-92, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23715204

RESUMO

Warthin tumor (papillary cystadenoma lymphomatosum, adenolymphoma) is a benign neoplasm from salivary glands and is almost restricted to the parotid gland and the periparotid lymph nodes. Its etiopathogenesis has been associated with tobacco smoke. Several authors believe that the tumor develops from heterotopic salivary gland tissues or through the attraction of a heavy lymphoid reaction. Most cases involve the lower pole or the tail of the parotid. Since its description, a few cases have been reported in other sites, like the submandibular salivary gland. This study aimed to describe a rare presentation of a Warthin tumor and discuss its etiology and differential diagnosis. A 72-year-old male patient presented an asymptomatic, nodular mass adjacent to the submandibular salivary gland. Based on clinical diagnosis of cervical lymphadenopathy, the patient underwent a surgical excision of the lesion. Histopathological exam revealed a benign neoplasm from salivary glands composed of two components: epithelial and lymphoid. The findings were consistent with Warthin tumor. Warthin tumor from submandibular salivary gland is a rare lesion. Professionals should not misinterpret their site of origin, as if they were from the lower pole or the tail of the parotid.


Assuntos
Adenolinfoma/diagnóstico , Erros de Diagnóstico , Neoplasias da Glândula Submandibular/diagnóstico , Adenolinfoma/patologia , Adenolinfoma/cirurgia , Idoso , Epitélio/patologia , Humanos , Doenças Linfáticas/diagnóstico , Tecido Linfoide/patologia , Masculino , Neoplasias da Glândula Submandibular/patologia , Neoplasias da Glândula Submandibular/cirurgia
12.
Plant Biol (Stuttg) ; 25(1): 161-175, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36278887

RESUMO

In Metrodorea nigra, a Rutaceae species with rhythmic growth, the shoot apex in the dormant stage is enclosed by modified stipules. The young organs are fully covered with peltate secretory trichomes, and these structures remain immersed in a hyaline exudate within a hood-shaped structure. Our study focused on the morpho-functional characterization of the peltate trichomes and cytological events associated with secretion. Shoot apices were collected during both dormant and active stages and processed for anatomical, cytochemical and ultrastructural studies. Trichomes initiate secretion early on, remain active throughout leaf development, but collapse as the leaves expand; at which time secretory cavities start differentiation in the mesophyll and secretion increases as the leaf reaches full expansion. The subcellular apparatus of the trichome head cells is consistent with hydrophilic and lipophilic secretion. Secretion involves two vesicle types: the smaller vesicles are PATAg-positive (periodic acid/thiocarbohydrazide/silver proteinate) for carbohydrates and the larger ones are PATAg-negative. In the first phase of secretory activity, the vesicles containing polysaccharides discharge their contents through exocytosis with the secretion accumulating beneath the cuticle, which detaches from the cell wall. Later, a massive discharge of lipophilic substances (lipids and terpenes/phenols) results in their accumulation between the wall and cuticle. Release of the secretions occurs throughout the cuticular microchannels. Continued protection of the leaves throughout shoot development is ensured by replacement of the collapsed secretory trichomes by oil-secreting cavities. Our findings provide new perspectives for understanding secretion regulation in shoot apices of woody species with rhythmic growth.


Assuntos
Rutaceae , Tricomas , Tricomas/ultraestrutura , Terpenos/química , Folhas de Planta/química , Fenóis/análise
13.
J Eur Acad Dermatol Venereol ; 26 Suppl 6: 14-5, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23067433

RESUMO

A 9-month-old infant, with no family history of atopy, presenting with erythematous, itchy plaques, and sleep disturbance, was diagnosed with atopic eczema (AE). Previous treatment with topical hydrocortisone and emollients had little effect. The infant was treated nightly with methylprednisolone aceponate (MPA) 0.1% (Advantan(®)) cream, in addition to emollients and an oral antihistamine. After 1 week of once-daily MPA 0.1% treatment, followed by 1 week of alternate-day treatment with Advantan, significant improvements in AE symptoms and sleep were observed. The patient's caregiver reported overall treatment satisfaction and no side effects of Advantan. For this infant with newly diagnosed AE, Advantan improved symptoms and sleep quality in a safe and well-tolerated manner.


Assuntos
Anti-Inflamatórios/uso terapêutico , Dermatite Atópica/tratamento farmacológico , Metilprednisolona/análogos & derivados , Transtornos do Sono-Vigília/etiologia , Administração Tópica , Anti-Inflamatórios/administração & dosagem , Dermatite Atópica/complicações , Humanos , Lactente , Masculino , Metilprednisolona/administração & dosagem , Metilprednisolona/uso terapêutico
14.
Eur Stroke J ; 6(2): 205-212, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34414296

RESUMO

INTRODUCTION: Systemic contraceptives increase the risk of ischemic stroke but little is known about the characteristics, mechanisms and long-term outcome post stroke of patients on hormonal contraception. We sought to To assess characteristics and outcome of acute ischemic stroke (AIS) in young women using systemic hormonal contraceptives (SHC) and compare them to strokes in non-contraceptive users. PATIENTS AND METHODS: Using the Acute STroke Registry and Analysis of Lausanne (ASTRAL), we analyzed demographics, risk factors, clinical, radiological and treatment data of consecutive female patients of <50 years between 2003 to 2015. We compared groups with and without SHC in a logistic regression analysis. RESULTS: Of the 179 female patients of <50 years during the observation period, 57 (39.6%) used SHC, 71.9% of whom, a combined oral contraceptive pill. On logistic regression contraceptive users were significantly younger but had comparable stroke severity. They had less migraine with aura and tobacco use, and more hyperlipidaemia. Also, contraceptive users had significantly less intra and extracranial stenosis and occlusion on arterial imaging, but more focal hypoperfusion on CT-perfusion. Undetermined mechanism of stroke was more frequent with SHC users, whereas rare mechanisms were more frequent in non-users. The contraceptive user group had a more favourable adjusted 12-month outcome with significantly fewer ischemic recurrences after stopping systemic contraception in all. CONCLUSION: Contraceptive users with ischemic strokes are younger and have lesser tobacco use and migraine with aura and more hyperlipidemia. Their stroke mechanism is more often undetermined using a standardised work-up, and their adjusted long-term outcome is more favourable with less stroke recurrence.

15.
Water Sci Technol ; 62(12): 2729-36, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-21123900

RESUMO

This paper presents a degradation study of the pesticide atrazine using photo-assisted electrochemical methods at a dimensionally stable anode (DSA(®)) of nominal composition Ti/Ru(0.3)Ti(0.7)O(2) in a prototype reactor. The effects of current density, electrolyte flow-rate, as well as the use of different atrazine concentrations are reported. The results indicate that the energy consumption is substantially reduced for the combined photochemical and electrochemical processes when compared to the isolated systems. It is observed that complete atrazine removal is achieved at low current densities when using the combined method, thus reducing the energy required to operate the electrochemical system. The results also include the investigation of the phytotoxicity of the treated solutions.


Assuntos
Atrazina/química , Técnicas Eletroquímicas , Herbicidas/química , Fotólise , Atrazina/farmacologia , Eletrodos , Herbicidas/farmacologia , Lactuca/efeitos dos fármacos , Estrutura Molecular , Poluentes Químicos da Água/química
16.
Science ; 223(4632): 139-44, 1984 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-6691139

RESUMO

Cancer mortality data from the National Center for Health Statistics, covering the period 1950 through 1978, were used to test a reported association between childhood leukemia and exposure to radioactive fallout from nuclear weapons tests in Nevada between 1951 and 1958. No pattern of temporal and geographic variation in risk supportive of the reported association was found. Comparison of these results with those presented in support of an association of risk with fallout suggests that the purported association merely reflects an anomalously low leukemia rate in southern Utah during the period 1944 to 1949.


Assuntos
Leucemia Induzida por Radiação/epidemiologia , Leucemia/mortalidade , Cinza Radioativa/efeitos adversos , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Nevada , Guerra Nuclear , Risco , Estatística como Assunto , Utah
17.
J Chem Phys ; 130(6): 064108, 2009 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-19222268

RESUMO

Douglas-Kroll-Hess (DKH) contracted Gaussian basis sets of double, triple, and quadruple zeta valence qualities plus polarization functions (XZP, X=D, T, and Q, respectively) for the atoms H-Ar and DZP and TZP for K-Kr are presented. They have been determined from the corresponding nonrelativistic basis sets generated previously by Jorge et al. We have recontracted the original XZP basis sets, i.e., the values of the contraction coefficients were reoptimized using the relativistic DKH Hamiltonian. The effect of DKH at the coupled-cluster level of theory on the ionization energy of some atoms and dissociation energy and geometric parameters for a sample of molecules is discussed. Our results were compared with theoretical and experimental values reported in the literature.

18.
J Comput Chem ; 29(14): 2434-44, 2008 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-18612996

RESUMO

Contracted basis sets of double zeta (DZ) quality for the atoms from K to Kr are presented. They were determined from fully optimized basis sets of primitive Gaussian-type functions generated in atomic Hartree-Fock calculations. Sets of Gaussian polarization functions optimized at the Möller-Plesset second-order level were added to the DZ basis set. This extends earlier work on segmented contracted DZ basis set for atoms H-Ar. From this set, using the BP86 nonhybrid and B3LYP hybrid functionals, dissociation energy, geometric parameters, harmonic vibrational frequency, and electric dipole moment of a set of molecules were calculated and compared with results obtained with other basis sets and with experimental data reported in the literature. In addition, (57)Fe and (77)Se nuclear magnetic resonance chemical shifts in Fe(C(5)H(5))(2), H(2)Se, and CSe(2) were calculated using density functional theory and gauge-including atomic orbitals and, then, compared with theoretical and experimental values previously published in the literature. Except for chemical shift, one verifies that our results give the best agreement with experimental and benchmark values.

19.
Plant Biol (Stuttg) ; 10(5): 660-73, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18761504

RESUMO

Extrafloral nectaries are nectar-secreting structures that are especially common among the woody flora of the Brazilian cerrado, a savanna-like vegetation. In this study, we provide morphological and anatomical descriptions of extrafloral nectaries (EFNs) occurring on vegetative and reproductive organs of several plant species from the cerrado, and discuss their function and ecological relevance. We describe the morphology and anatomy of EFNs of 40 species belonging to 15 woody families using scanning electron microscopy and light microscopy. We categorise EFNs following a structural-topographical classification, and characterise the vascularised and complex nectaries, amorphous nectaries and secretory trichomes. Fabaceae, Bignoniaceae, Malpighiaceae and Vochysiaceae were the plant families with the majority of species having EFNs. Ten species possess more than one morphotype of gland structure. Observations and experimental field studies in the cerrado support the anti-herbivore role of EFN-gathering ants in this habitat. Additional morphological studies of EFNs-bearing plants, including other growth forms (e.g. herbs and lianas), are being undertaken and will hopefully cast further light on the ecological relevance of these glands in the cerrado, especially with respect to their attractiveness to multiple visitors.


Assuntos
Metabolismo dos Carboidratos , Magnoliopsida/ultraestrutura , Bignoniaceae/fisiologia , Bignoniaceae/ultraestrutura , Brasil , Ecossistema , Fabaceae/fisiologia , Fabaceae/ultraestrutura , Magnoliopsida/fisiologia , Malpighiaceae/fisiologia , Malpighiaceae/ultraestrutura
20.
J Hazard Mater ; 156(1-3): 170-7, 2008 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-18242835

RESUMO

The present paper presents the study of the decolourisation of real textile effluent by constant current electrolysis in a flow-cell using a DSA type material. The effect of using different anode materials (Ti/Ru(0.3)Ti(0.7)O(2); Ti/Ir(0.3)Ti(0.7)O(2); Ti/Ru(X)Sn(1-X)O(2), where X=0.1, 0.2 or 0.3) on the efficiency of colour removal is discussed. Attempts to perform galvanostatic oxidation (40 and 60 mA cm(-2)) on the as-received effluent demonstrate that colour removal and total organic carbon (TOC) removal are limited. In this case the greatest degree of colour removal is achieved when anode containing 90% SnO(2) is used. If the conductivity of the effluent is increased by adding NaCl (0.1 mol L(-1)) appreciable colour/TOC removal is observed. The efficiencies of colour and TOC removal are discussed in terms of the energy per order (E(EO)/kW h m(-3)order(-1)) and energy consumption (E(C)/kW h kg(-1)TOC), respectively. Finally, the extent of colour removal is compared to consent levels presented in the literature.


Assuntos
Cor , Eletroquímica/métodos , Eletrodos , Resíduos Industriais , Indústria Têxtil , Indicadores e Reagentes , Espectrofotometria Ultravioleta
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