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1.
Artigo em Inglês | MEDLINE | ID: mdl-25768644

RESUMO

In the referred paper, the authors use a numerical method for solving ordinary differential equations and a softened Coulomb potential -1/√[x(2)+ß(2)] to study the one-dimensional Coulomb problem by approaching the parameter ß to zero. We note that even though their numerical findings in the soft potential scenario are correct, their conclusions do not extend to the one-dimensional Coulomb problem (ß=0). Their claims regarding the possible existence of an even ground state with energy -∞ with a Dirac-δ eigenfunction and of well-defined parity eigenfunctions in the one-dimensional hydrogen atom are questioned.

2.
Water Sci Technol ; 66(7): 1384-91, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22864421

RESUMO

Membrane wastewater treatment plants (WWTPs) have several advantages compared with conventionally designed WWTPs with classical purification techniques. The filtration process is the key to their commercial success in Germany with respect to energy consumption and effectiveness, enabled by the optimization of filtration using a dynamic simulation model. This work is focused on the development of a robust, flexible and practically applicable membrane simulation model for submerged hollow-fibre and flat-sheet membrane modules. The model is based on standard parameters usually measured on membrane WWTPs. The performance of the model is demonstrated by successful calibration and validation for three different full-scale membrane WWTPs achieving good results. Furthermore, the model is combinable with Activated Sludge Models.


Assuntos
Reatores Biológicos , Membranas Artificiais , Eliminação de Resíduos Líquidos/métodos , Purificação da Água/métodos , Simulação por Computador , Modelos Teóricos
3.
Phys Rev E Stat Nonlin Soft Matter Phys ; 63(6 Pt 1): 061104, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11415065

RESUMO

The effect of quenched disorder on the underdamped motion of a periodically driven particle on a ratchet potential is studied. As a consequence of disorder, current reversal and chaotic diffusion may take place on regular trajectories. On the other hand, on some chaotic trajectories disorder induces regular motion. A localization effect similar to the Golosov phenomenon sets in whenever a disorder threshold that depends on the mass of the particle is reached. Possible applications of the localization phenomenon are discussed.

4.
Phys Rev Lett ; 85(15): 3321-4, 2000 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-11019331

RESUMO

The effects of quenched disorder on the overdamped motion of a driven particle on a periodic, asymmetric potential are studied. While for the unperturbed potential the transport is due to a regular drift, the quenched disorder induces a significant additional chaotic "diffusive" motion. Possible applications to experiments in nanoscale surfaces and particle separation are discussed.


Assuntos
Modelos Teóricos , Difusão , Processos Estocásticos
5.
An. Fac. Med. Univ. Fed. Pernamb ; 40(2): 102-5, 1995. ilus
Artigo em Português | LILACS | ID: lil-222931

RESUMO

Para estudar a influência do processo granulomatoso esquistossomóticosobre as células ganglionares mioentéricas, foram utilizados 30 camundongos albinos Swiss infectadoscom 50 cercárias da cepa SLM do S. mansoni.O grupo controle foi constituído por dez animais näo infectados. Após sessenta dias de infecçäo, cortes histológicos do intestino delgadocorados por hematoxilina-eosina e P.A.S. demonstraram granulomas periovulares em todas as camadas da parede intestinal. Através do método imunohistoquímico indireto, usando-se a enolase neurônio-específica como marcador, observou-se desorganizaçäo do plexo mioentêrico em áreas contendo granulomas. Além disso, ocorreu rarefaçäo das estaçöes ganglionares, com aparente destruiçäo de células neuronais. A possível contribuiçäo dessas alteraçöes para a sintomatologia da esquistossomose humana é avaliada


Assuntos
Animais , Camundongos , Ensaio Clínico , Esquistossomose mansoni/fisiopatologia , Células Enteroendócrinas/fisiologia , Células Enteroendócrinas/parasitologia
6.
Phytochemistry ; 37(4): 1045-53, 1994 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-7765655

RESUMO

In a leaf flavonoid survey of 15 Brazilian orchid species from the subtribe Ornithocephalinae, flavone C-glycosides were found to be the major constituents in all except two Ornithocephalus taxa. In Zygostates cornuta a rare glycoside, apigenin 7,4'-dimethyl ether 6-C-glucoside-2"-O-rhamnoside, was identified. This also occurred in Z. alleniana, Z. lunata, Z. pellucida and Z. pustulata. Two further similar apigenin 7,4'-dimethyl ether C-glycoside-O-rhamnosides, possibly with different C-linked sugars, were detected in Z. multiflora and Z. grandiflora. In Z. cornuta, apigenin 4'-methyl ether 6-C-glucoside-2"-O-rhamnoside was found to co-occur with the apigenin 7,4'-dimethyl ether derivative. Ornithocephalus myrticola was distinguished by the presence of an apigenin 8-C-methylpentoside and three apigenin 7-methyl ether 8-C-glycoside derivatives. In O. bicornis and O. kruegeri, another apigenin 7,4'-dimethyl ether C-glycoside was found, while from Phymatidum falcifolium, apigenin 7,4'-dimethyl ether and apigenin 7-methyl ether C-glycosides and their O-arabinosides were isolated. Chytroglossa marileoniae also contained an apigenin 7,4'-dimethyl ether C-glycoside, which appeared to be the same as that in P. falcifolium. Rauhiella silvana, on the other hand, could be distinguished from all the other taxa studied by the absence of methylated C-glycosylflavones and presence of isovitexin. 6-Hydroxyflavone O-glycosides, which are characteristic leaf constituents of some Oncidium species in the related subtribe Oncidinae were not detected in the present sample.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Flavonoides/análise , Glicosídeos/análise , Plantas/química , Sequência de Carboidratos , Metilação , Dados de Sequência Molecular , Plantas/classificação
7.
Arq Neuropsiquiatr ; 46(1): 49-60, 1988 Mar.
Artigo em Português | MEDLINE | ID: mdl-3136760

RESUMO

Twenty one cases of schistosomal meningomyeloradiculopathy due to Schistosoma mansoni are reported. This result was attained after a 4- year research period based on a "Clinical and Laboratory Investigation Protocol" applied on 212 patients in Itabuna, a city of Southeast region of Bahia state in the Northeast of Brazil. This region is a non endemic one for schistosomiasis. The Protocol consisted in leading to investigation every patient that presented a clinical triad characterized by: lumbar pain, paresthesias in the inferior limbs, miction difficulties. Diagnostic criteria were based on clinical neurologic signs, presence of Schistosoma mansoni eggs on feces or rectum biopsy, positive immunofluorescence reaction for schistosomiasis in the cerebrospinal fluid (CSF), the inflammatory CSF characteristics, and an exhaustive research for differential diagnosis. The diagnosis has been essentially based on clinical and laboratory data, not having for any of the cases an histopathological study. The treatment was performed the earliest as possible, and corticosteroids associated to oxaminiquine were used for all cases. The patients were studied as to sex, age, profession, city of origin, initial symptoms, laboratory tests related to schistosomiasis, the onset type of neurologic clinical symptoms and several CSF aspects. Treatment beginning was related with time of disease. Clinical evolution and sequelae were analysed. Abdominal contractions were observed in 10 cases several hours before the clinical picture had been clearly presented. Clinical diagnosis is justified since it is performed under severe clinical and laboratory evidences, as well as an accurate search for differential diagnosis. The authors think that the schistosomal meningomyeloradiculopathy is a well defined nosological entity by its neurological picture, as also from the pathological point of view. Finally, the authors suggest to neurological services of the country the planning and application of similar or even more detailed Protocol in order to obtain an early diagnosis and treatment for the disease, preventing so irreversible damages and sequelae very harmful for the patients in their social life.


Assuntos
Meningite/etiologia , Mielite/etiologia , Radiculopatia/etiologia , Esquistossomose mansoni/complicações , Adolescente , Adulto , Doenças do Sistema Nervoso Central/líquido cefalorraquidiano , Doenças do Sistema Nervoso Central/diagnóstico , Doenças do Sistema Nervoso Central/tratamento farmacológico , Criança , Diagnóstico Diferencial , Feminino , Humanos , Técnicas Imunológicas , Masculino , Pessoa de Meia-Idade , Esquistossomose mansoni/tratamento farmacológico
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