359 research outputs found
Guiding properties of a non-isothermal atmosphere for acoustic-gravity waves
The propagation of pressure waves in a stratified,
non-isothermal atmosphere is studied in the linear approximation. It is found that acoustic and
acoustic-gravity waves can be horizontally guided by the effect of the Earth’s thermocline alone, under very mild conditions on the temperature gradient steepness. The effect of the Earth’s surface is also studied. Lamb’s modes associated with the rigid surface are, then, identified and their behaviour, as a function of the Earth’s position, is discussed. Finally, dissipation is included, and its effect is derived using a perturbation technique
Considerações Sobre o Tratamento Ortodôntico Em Pacientes Com Comprometimento Periodontal
TCC (graduação) – Universidade Federal de Santa Catarina, Centro de Ciências da Saúde, OdontologiaA crescente procura de pacientes com comprometimento periodontal por tratamento ortodôntico pode ser explicada por diversos fatores, dentre eles a busca por vantagens estéticas, periodontais e funcionais, sendo assim costumeiramente está associado a outras especialidades. A maioria destes pacientes tem motivação própria para buscar o tratamento, sendo realista quanto aos resultados que podem ser obtidos; todavia são menos tolerantes aos incômodos que por ventura possam ocorrer durante o tratamento odontológico. A presença do periodonto reduzido não afasta a possibilidade de receber intervenção ortodôntica, mas sugere certas particularidades, como a necessidade de utilizar forças leves e manter um controle rigoroso da placa bacteriana, através de cuidado profissional e higiene por parte do paciente, a fim de manter o tecido gengival saudável durante o tratamento ortodôntico ativo, de forma a não produzir efeitos nocivos no decorrer do tratamento. Além disso, em relação aos objetivos finais do tratamento, o alcance de parâmetros clássicos de normalidade não é obrigatório, o mais importante é restabelecer a relação oclusal fisiológica e quando possível, melhorar a estética. A movimentação dentária benéfica para os pacientes periodontais pode ser obtida de diversas formas, principalmente realizando intrusão e extrusão, seguindo os critérios quanto à magnitude de força, controle de placa e sistema mecânico. A intrusão é recomendada para dentes com perda óssea horizontal e bolsas infra-ósseas, e possibilita maior quantidade de suporte alveolar, com reinserção das fibras periodontais. Já a extrusão é indicada na redução de defeitos infra-ósseos e no aumento do comprimento da coroa clínica, ocasionando mudanças na arquitetura de tecidos moles e duros do periodonto que possibilitam neo formação óssea nas cristas alveolares e mudanças da placa supra para subgengival
Incorporating changes in albedo in estimating the climate mitigation benefits of land use change projects
International audienceSome climate scientists are questioning whether the practice of converting of non-forest lands to forest land (afforestation or reforestation) is an effective climate change mitigation option. The discussion focuses particularly on areas where the new forest is primarily coniferous and there is significant amount of snow since the increased climate forcing due to the change in albedo may counteract the decreased climate forcing due to carbon dioxide removal. In this paper, we develop a stand-based model that combines changes in surface albedo, solar radiation, latitude, cloud cover and carbon sequestration. As well, we develop a procedure to convert carbon stock changes to equivalent climatic forcing or climatic forcing to equivalent carbon stock changes. Using the model, we investigate the sensitivity of combined affects of changes in surface albedo and carbon stock changes to model parameters. The model is sensitive to amount of cloud, atmospheric absorption, timing of canopy closure, carbon sequestration rate among other factors. The sensitivity of the model is investigated at one Canadian site, and then the model is tested at numerous sites across Canada. In general, we find that the change in albedo reduces the carbon sequestration benefits by approximately 30% over 100 years, but this is not drastic enough to suggest that one should not use afforestation or reforestation as a climate change mitigation option. This occurs because the forests grow in places where there is significant amount of cloud in winter. As well, variations in sequestration rate seem to be counterbalanced by the amount and timing of canopy closure. We close by speculating that the effects of albedo may also be significant in locations at lower latitudes, where there are less clouds, and where there are extended dry seasons. These conditions make grasses light coloured and when irrigated crops, dark forests or other vegetation such as biofuels replace the grasses, the change in carbon stocks may not compensate for the darkening of the surface
Design of a distributed control system based on CORBA and Java for a new rib facility at LNL
Abstract SPES (Study for the Production of Exotic Species) [1] is a L.N.L. project that will produce by the end of this year the design of a facility for Radioactive Ion Beams (RIBs) originated by fission fragments produced by secondary neutrons; it will be characterized by moderate size, performance and cost and will produce also intense neutron beams for activities both in fundamental and applied Nuclear Physics. In the context of this design study and tightly related to the medium size of this facility, the architecture of a distributed control system using the Common Object Request Broker Architecture (CORBA, [2]) as middleware framework and Java as main programming language was investigated for the core components (diagnostics, optics, RF-control) of the primary accelerator. The performances of CORBA middleware for the high level control system were measured in different conditions and shown to be sufficient to cover the requirements for remote operations (all feedback loops will be performed either in specialized hardware or by dedicated real-time embedded controllers). A minimal programming effort, a good level of modularity and long-term maintenance were some of the reasons to choose Java [3] and its related Integrated Development Environments (IDEs) as the main programming language and as a software platform for the Graphical User Interface (GUI) and the middleware implementations of this project
A case of capecitabine-induced coronary microspasm in a patient with rectal cancer
5-Fluorouracil (5-FU) is the most frequently used chemotherapy agent concomitant with radiotherapy in the management of patients with rectal cancer. Capecitabine is an oral fluoropyrimidine that mimics the pharmaconkinetics of infusional 5-FU. This new drug is replacing 5-FU as a part of the combined-modality treatment of a number of gastrointestinal cancers. While cardiac events associated with the use of 5-FU are a well known side effect, capecitabine-induced cardiotoxicity has been only rarely reported. Here, we reviewed the case of a patient with rectal cancer who had a capecitabine-induced coronary vasospasm. The most prominent mutation of the dihydropyrimidine dehydrogenase gene was also analyzed
Platelet rich plasma from different preparations: effect on chondrocytes and synoviocytes of osteoarthritis patients
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Good manufacturing practices in autologous chondrocyte implantation: the experience in a public hospital
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Visualization of Myelin Basic Protein (Mbp) T Cell Epitopes in Multiple Sclerosis Lesions Using a Monoclonal Antibody Specific for the Human Histocompatibility Leukocyte Antigen (Hla)-Dr2–Mbp 85–99 Complex
Susceptibility to multiple sclerosis (MS) is associated with the human histocompatibility leukocyte antigen (HLA)-DR2 haplotype, suggesting that major histocompatibility complex class II–restricted presentation of central nervous system–derived antigens is important in the disease process. Antibodies specific for defined HLA-DR2–peptide complexes may therefore be valuable tools for studying antigen presentation in MS. We have used phage display technology to select HLA-DR2–peptide-specific antibodies from HLA-DR2–transgenic mice immunized with HLA-DR2 molecules complexed with an immunodominant myelin basic protein (MBP) peptide (residues 85–99). Detailed characterization of one clone (MK16) demonstrated that both DR2 and the MBP peptide were required for recognition. Furthermore, MK16 labeled intra- and extracellular HLA-DR2–MBP peptide complexes when antigen-presenting cells (APCs) were pulsed with recombinant MBP. In addition, MK16 inhibited interleukin 2 secretion by two transfectants that expressed human MBP–specific T cell receptors. Analysis of the structural requirement for MK16 binding demonstrated that the two major HLA-DR2 anchor residues of MBP 85–99 and the COOH-terminal part of the peptide, in particular residues Val-96, Pro-98, and Arg-99, were important for binding. Based on these results, the antibody was used to determine if the HLA-DR2–MBP peptide complex is presented in MS lesions. The antibody stained APCs in MS lesions, in particular microglia/macrophages but also in some cases hypertrophic astrocytes. Staining of APCs was only observed in MS cases with the HLA-DR2 haplotype but not in cases that carried other haplotypes. These results demonstrate that HLA-DR2 molecules in MS lesions present a myelin-derived self-peptide and suggest that microglia/macrophages rather than astrocytes are the predominant APCs in these lesions
Disminución de la reserva de flujo coronario en pacientes con insuficiencia cardíaca no isquémica
Introduction and objectives. Coronary flow reserve
(CFR) is impaired not only in ischemic heart disease, but
also in cardiac diseases that may or may not course with
heart failure. The aim of the present study was to determine
if the severity of heart failure can influence CFR impairment.
Methods. Forty patients with non-ischemic heart disease
and heart failure were studied 41 times. Four groups
were established: 1. 10 patients in functional class III-IV;
2. 10 patients in functional class II not taking beta-blockers;
3. 11 patients in class II treated with carvedilol, and 4.
10 patients in class I. These patients had a history of heart
failure and systolic dysfunction. Myocardial blood flow
(MBF) was measured with positron emission tomography
(PET) and N-13 ammonia at rest (r) and during adenosine
triphosphate (ATP) infusion.
Results. MBF and CFR were significantly higher in
group 4 (1.95 ± 0.58 and 2.40 ± 0.95 ml/min/g) than in
group 1 (1.02 ± 0.52 and 1.46 ± 0.48 ml/min/g). CFR tended
to be higher in groups 2 (1.73 ± 0.72), and 3 (1.89 ±
0.75) vs group 1. No significant correlation was found between
CFR and the following variables: age, systolic blood
pressure, ventricular mass index, ventricular volume indexes,
and ejection fraction.
Conclusions. Coronary microvascular function is impaired
in non-ischemic heart failure, and the impairment is
related to functional class, regardless of the underlying
responsible heart disease
Patient-reported experiences of cancer care related to the COVID-19 pandemic in Switzerland.
This study aims to describe the experience of Swiss oncological patients during the COVID-19 pandemic.
A national multi-center study including five hospitals covering the three main language regions of Switzerland was conducted between March and July 2021. Patients with melanoma, breast, lung, or colon cancer receiving active systemic anti-cancer treatment at the time of the COVID-19 pandemic were included. We conducted semi-structured telephone or onsite interviews alongside the administration of distress and resilience-validated questionnaires. Thematic analysis was performed for the qualitative data and descriptive statistics for the quantitative data.
Sixty-two cancer patients with a mean age of 61 (SD=14) (58% female) were interviewed. Based on the interviews, we identified that the experience of having cancer during the COVID-19 pandemic was related to five dimensions: psychological, social, support, healthcare, and vaccination. Three themes transverse the five dimensions: (a) needs, (b) positive changes, and (c) phases of the pandemic. In general, patients did not experience delays or disruptions in their cancer treatment nor felt additionally burdened by the pandemic. Lockdown and isolation were reported as mixed experiences (positive and negative), and access to vaccination reassured patients against the risk of infection and instilled hope to return to normalcy. Additionally, we found low distress levels (M=2.9; SD=2.5) and high resilience scores (M=7; SD=1.3) in these patients.
Swiss patients with cancer did not express major needs or disruptions in their care during this period of the COVID-19 pandemic. Results identify the mixed experiences of patients and highlight the high resilience levels
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