Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 12 de 12
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Sci Total Environ ; 905: 167102, 2023 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-37717759

RESUMO

Lake Erie is the most at risk of the Great Lakes for degraded water quality due to non-point source pollution caused by agricultural activities in the lake's watershed. The extent and temporal patterns of nutrient loading from these agricultural activities is influenced by the timing of agronomic events, precipitation events, and water flow through areas of natural filtration within the watershed. Downstream impacts of these nutrient loading events may be moderated by the co-loading of functionally relevant biogeochemical cycling microbial communities from agricultural soils. This study quantified loading patterns of these communities from tile drain sources, assessed whether functional communities from agricultural sources influenced downstream microbial functionality, and investigated how distance from agricultural sources, storm events, and areas of natural filtration altered nutrient cycling and nutrient fluxes in aquatic and sediment environments. Water and sediment samples were collected in the Wigle Creek watershed in Ontario, from tile drains through to Lake Erie, from May to November 2021, and microbial nitrogen (N) and phosphorous (P) cycling capacity (quantitative PCR), and nutrient levels were evaluated. Results showed that N and P functional groups were co-loaded with nutrients, with increased loading occurring during storm events and during agricultural activities including fertilization and harvest. Overall functional capacity in the aquatic environment decreased with distance from the agricultural sources and as water transited through natural filtration areas. In contrast, the sediment environment was more resilient to both agricultural disturbances and abiotic factors. This study expands our understanding of when and where different stages of N and P cycling occurs in agriculturally impacted watersheds, and identifies both seasons and regions to target with nutrient mitigation strategies.


Assuntos
Lagos , Qualidade da Água , Agricultura , Fósforo/análise , Solo , Nitrogênio/análise , Monitoramento Ambiental/métodos
2.
Internist (Berl) ; 61(12): 1298-1303, 2020 Dec.
Artigo em Alemão | MEDLINE | ID: mdl-32945927

RESUMO

A possible classical complication of Crohn's disease is the formation of a stenosis, which can occur throughout the course of the disease and can present differently depending on the narrowing of the lumen. This article reports the case of a 39-year-old male patient with a stenosing terminal ileitis, which was ultimately only manifested after obstruction by a foreign body.


Assuntos
Doença de Crohn/complicações , Corpos Estranhos , Ileíte/diagnóstico , Adulto , Constrição Patológica , Doença de Crohn/diagnóstico , Doença de Crohn/cirurgia , Humanos , Ileíte/etiologia , Ileíte/cirurgia , Obstrução Intestinal/complicações , Obstrução Intestinal/etiologia , Masculino
5.
Exp Brain Res ; 214(2): 303-15, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21847644

RESUMO

Fatigue post-stroke is a disabling and persistent symptom affecting many stroke survivors. Despite its high prevalence, the pathophysiology underlying this phenomenon remains obscure. The aim of the present study was to investigate the origins of neuromuscular fatigue post-stroke. Ten chronic stroke survivors and 10 controls sustained an isometric contraction at 30% of maximal voluntary contraction (MVC) with the ankle dorsiflexors. Motor evoked potential (MEP), cortical silent period (SP), voluntary activation, M wave and contractile properties were evaluated before, during and after fatigue among the paretic, non-paretic and control limbs. The pattern of response to fatigue in the non-paretic and control limbs was comparable; therefore, results are presented between the paretic and non-paretic limbs. Before fatigue, reduced MVC peak torque and MEP amplitude were observed on the paretic side in comparison with the non-paretic side. During fatigue, the cortical SP duration increased significantly in both limbs, whereas the MEP amplitude significantly increased only in the non-paretic limb. After fatigue, MVC peak torque decreased significantly in both limbs. Significant reductions in M wave and twitch peak torque were observed in both limbs, pointing to the development of peripheral fatigue. However, central fatigue, evident by a significant reduction in voluntary activation, was greater in the paretic than in the non-paretic limb. After stroke, an inability to increase central excitability in response to an increased cortical inhibition associated with the fatiguing contraction may contribute to central fatigue observed in the paretic limb, which may also be linked to increased self-reported fatigue during activities of daily living. These findings advance our understanding of the neuromuscular basis of fatigue post-stroke.


Assuntos
Contração Muscular/fisiologia , Fadiga Muscular/fisiologia , Paresia/fisiopatologia , Acidente Vascular Cerebral/fisiopatologia , Adulto , Idoso , Estimulação Elétrica/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Paresia/diagnóstico , Acidente Vascular Cerebral/diagnóstico
6.
J Dent ; 35(6): 528-34, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17418474

RESUMO

OBJECTIVES: Compare occlusal contacts calculated from 3D virtual models created from clinical records to contacts identified clinically using shimstock and transillumination. METHODS: Upper and lower full arch alginate impressions and vinyl polysiloxane centric interocclusal records were made of 12 subjects. Stone casts made from the alginate impressions and the interocclusal records were optically scanned. Three-dimensional virtual models of the dental arches and interocclusal records were constructed using the Virtual Dental Patient Software. Contacts calculated from the virtual interocclusal records and from the aligned upper and lower virtual arch models were compared to those identified clinically using 0.01mm shimstock and transillumination of the interocclusal record. Virtual contacts and transillumination contacts were compared by anatomical region and by contacting tooth pairs to shimstock contacts. Because there is no accepted standard for identifying occlusal contacts, methods were compared in pairs with one labeled "standard" and the second labeled "test". Accuracy was defined as the number of contacts and non-contacts of the "test" that were in agreement with the "standard" divided by the total number of contacts and non-contacts of the "standard". RESULTS: Accuracy of occlusal contacts calculated from virtual interocclusal records and aligned virtual casts compared to transillumination were: 0.87+/-0.05 and 0.84+/-0.06 by region and 0.95+/-0.07 and 0.95+/-0.05 by tooth, respectively. Comparisons with shimstock were: 0.85+/-0.15 (record), 0.84+/-0.14 (casts), and 81+/-17 (transillumination). CONCLUSIONS: The virtual record, aligned virtual arches, and transillumination methods of identifying contacts are equivalent, and show better agreement with each other than with the shimstock method.


Assuntos
Oclusão Dentária , Processamento de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Coroa do Dente/anatomia & histologia , Adulto , Alginatos/química , Relação Central , Estudos Transversais , Arco Dental/anatomia & histologia , Materiais para Moldagem Odontológica/química , Técnica de Moldagem Odontológica/instrumentação , Registros Odontológicos , Feminino , Humanos , Registro da Relação Maxilomandibular/instrumentação , Masculino , Pessoa de Meia-Idade , Modelos Dentários , Polivinil/química , Siloxanas/química , Propriedades de Superfície , Transiluminação , Interface Usuário-Computador
7.
Clin Nurs Res ; 5(4): 428-40, 1996 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-8970280

RESUMO

The addition of wheat fiber in the diet of post-surgical orthopedic patients as a means of preventing constipation was studied using a quasi-experimental design. It was hypothesized that a 20 gm supplement of All Bran and natural bran would promote spontaneous bowel movements, reduce the incidence of constipation, and thus decrease the need for elimination interventions. The results show that the study group had more spontaneous bowel movements and required fewer elimination interventions than did the control group.


Assuntos
Constipação Intestinal/prevenção & controle , Fibras na Dieta/administração & dosagem , Prótese Articular/efeitos adversos , Adulto , Idoso , Idoso de 80 Anos ou mais , Avena , Humanos , Masculino , Pessoa de Meia-Idade
8.
Clin Exp Immunol ; 37(3): 551-7, 1979 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-315848

RESUMO

Purified human mononuclear cell subpopulations have been evaluated in the in vitro lymphocyte proliferation assay. Monocyte-depleted mononuclear cells had reduced or absent responses to mitogens and antigens which could be restored to the original mononuclear cell response by addition of purified plastic adherent cells. Purified T lymphocytes obtained by density gradient centrifugation of E-rosette-forming cells demonstrated low but significant proliferative responses to mitogens, but no significant response to antigens. The addition of monocytes potentiated the response of purified T cells to mitogens and antigens, but did not fully reconstitute the original mononuclear cell response unless non-T lymphocytes were also present. It is concluded that mononuclear cell proliferation represents a complex mechanism of cellular interaction involving multiple subpopulations of cells.


Assuntos
Leucócitos/imunologia , Ativação Linfocitária , Macrófagos/imunologia , Antígenos/imunologia , Adesão Celular , Humanos , Mitógenos/farmacologia , Monócitos/imunologia , Formação de Roseta , Linfócitos T/imunologia , Linfócitos T/metabolismo , Timidina/metabolismo
9.
J Speech Hear Disord ; 43(2): 263-9, 1978 May.
Artigo em Inglês | MEDLINE | ID: mdl-661264

RESUMO

A wireless intraoral electrolarynx for laryngectomy patients has been developed. The instrument consists of an earphone receiver and a pickup coil housed in the patient's denture. A separate transmitter with hand switch, worn under the patient's clothing, activates the receiver. Intelligibility testing revealed that this device was comparable to the Verbalizer Electrolarynx, a transoral instrument similar to the Cooper-Rand Electrolarynx. If the long-term endurance study now in progress proves that the device can meet the communicative needs of the laryngectomee, and if the favorable results obtained in this study can be duplicated with subsequent instruments, this electrolarynx may be a viable alternative to others now available.


Assuntos
Laringectomia , Boca , Voz Alaríngea/instrumentação , Humanos , Obturadores Palatinos/instrumentação
10.
J Bioeng ; 2(1-2): 47-57, 1978 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-681320

RESUMO

Numerous speech processing techniques have been applied to assist hearing-impaired subjects with extreme high-frequency hearing losses who can be helped only to a limited degree with conventional hearing aids. The results of providing this class of deaf subjects with a speech encoding hearing aid, which is able to reproduce intelligible speech for their particular needs, have generally been disappointing. There are at least four problems related to bandwidth compression applied to the voiced portion of speech: (1) the problem of pitch extraction in real time; (2) pitch extraction under realistic listening conditions, i.e. when competing speech and noise sources are present; (3) an insufficient data base for successful compression of voiced speech; and (4) the introduction of undesirable spectral energies in the bandwidth-compressed signal, due to the compression process itself. Experiments seem to indicate that voiced speech segments bandwidth limited to f = 1000 Hz, even at a loss of higher formant frequencies, is in most instances superior in intelligibility compared to bandwidth-compressed voiced speech segments of the same bandwidth, even if pitch can be extracted with no error. With the added complexity of real-time pitch extraction which has to function in actual listening conditions, it is doubtful that a speech encoding hearing aid, based on bandwidth compression on the voiced portion of speech, could be successfully implemented. However, if bandwidth compression is applied to the unvoiced portions of speech only, the above limitations can be overcome (1).


Assuntos
Fala/fisiologia , Percepção Auditiva , Fenômenos Biofísicos , Biofísica , Surdez/terapia , Auxiliares de Audição , Humanos , Masculino
11.
Lancet ; 2(8043): 844-7, 1977 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-72195

RESUMO

4 young children with active cytomegalovirus (C.M.V.) infection were found, by an in-vitro lymphocyte-proliferation assay, to have a C.M.V.-specific cell-mediated immune defect. These children had antibodies to C.M.V. and were actively shedding C.M.V. in the urine when studied. Their general cellular immune responses were intact, with normal numbers of T lymphocytes and normal in-vitro responses to mitogens and at least one antigen. 3 of the 4 mothers studied shortly after delivery had decreased cell-mediated immunity to C.M.V. These findings suggest that an antigen-specific immune defect facilitates transmission of virus from mother to infant and permits persistence of viral replication in the offspring.


Assuntos
Portador Sadio/imunologia , Infecções por Citomegalovirus/imunologia , Imunidade Celular , Síndromes de Imunodeficiência/imunologia , Troca Materno-Fetal , Adulto , Anticorpos Antivirais/isolamento & purificação , Portador Sadio/microbiologia , Pré-Escolar , Citomegalovirus/imunologia , Citomegalovirus/isolamento & purificação , Infecções por Citomegalovirus/microbiologia , Feminino , Humanos , Síndromes de Imunodeficiência/microbiologia , Técnicas Imunológicas , Técnicas In Vitro , Lactente , Recém-Nascido , Linfócitos/imunologia , Masculino , Gravidez , Replicação Viral
12.
J Bioeng ; 1(3): 165-71, 1977 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-615875

RESUMO

Many patients who have failed to acquire esophageal speech after total laryngectomy are presently using artificial electrolarynges. Two of the principle objections to currently available devices are their bulkiness and visibility. The authors have developed and tested a wireless-controlled intra-oral electrolarynx which overcomes these main objections. In addition, it produces intelligible speech which compares favorably with other existing devices. In this paper, the design details will be presented which significantly influence the performance and the patients' acceptability of the new device.


Assuntos
Órgãos Artificiais , Prótese Total Superior/instrumentação , Eletrônica Médica/instrumentação , Laringe , Fontes de Energia Elétrica , Humanos , Voz Alaríngea
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...