Remarks on the Formulation of Quantum Mechanics on Noncommutative Phase Spaces

We consider the probabilistic description of nonrelativistic, spinless one-particle classical mechanics, and immerse the particle in a deformed noncommutative phase space in which position coordinates do not commute among themselves and also with canonically conjugate momenta. With a postulated normalized distribution function in the quantum domain, the square of the Dirac delta density distribution in the classical case is properly realised in noncommutative phase space and it serves as the quantum condition. With only these inputs, we pull out the entire formalisms of noncommutative quantum mechanics in phase space and in Hilbert space, and elegantly establish the link between classical and quantum formalisms and between Hilbert space and phase space formalisms of noncommutative quantum mechanics. Also, we show that the distribution function in this case possesses 'twisted' Galilean symmetry.Comment: 25 pages, JHEP3 style; minor changes; Published in JHE

The Fuzzy Disc

We introduce a finite dimensional matrix model approximation to the algebra of functions on a disc based on noncommutative geometry. The algebra is a subalgebra of the one characterizing the noncommutative plane with a * product and depends on two parameters N and theta. It is composed of functions which decay exponentially outside a disc. In the limit in which the size of the matrices goes to infinity and the noncommutativity parameter goes to zero the disc becomes sharper. We introduce a Laplacian defined on the whole algebra and calculate its eigenvalues. We also calculate the two--points correlation function for a free massless theory (Green's function). In both cases the agreement with the exact result on the disc is very good already for relatively small matrices. This opens up the possibility for the study of field theories on the disc with nonperturbative methods. The model contains edge states, a fact studied in a similar matrix model independently introduced by Balachandran, Gupta and Kurkcuoglu.Comment: 17 pages, 8 figures, references added and correcte

Management of post-acute COVID-19 patients in geriatric rehabilitation: EuGMS guidance

Purpose To describe a guidance on the management of post-acute COVID 19 patients in geriatric rehabilitation. Methods The guidance is based on guidelines for post-acute COVID-19 geriatric rehabilitation developed in the Netherlands, updated with recent insights from literature, related guidance from other countries and disciplines, and combined with experiences from experts in countries participating in the Geriatric Rehabilitation Special Interest Group of the European Geriatric Medicine Society. Results This guidance for post-acute COVID-19 rehabilitation is divided into a section addressing general recommendations for geriatric rehabilitation and a section addressing specific processes and procedures. The Sect. "General recommendations for geriatric rehabilitation" addresses: (1) general requirements for post-acute COVID-19 rehabilitation and (2) critical aspects for quality assurance during COVID-19 pandemic. The Sect. "Specific processes and procedures", addresses the following topics: (1) patient selection; (2) admission; (3) treatment; (4) discharge; and (5) follow-up and monitoring. Conclusion Providing tailored geriatric rehabilitation treatment to post-acute COVID-19 patients is a challenge for which the guidance is designed to provide support. There is a strong need for additional evidence on COVID-19 geriatric rehabilitation including developing an understanding of risk profiles of older patients living with frailty to develop individualised treatment regimes. The present guidance will be regularly updated based on additional evidence from practice and research.Key summary pointsAim To describe a guidance on the management of post-acute COVID 19 patients in geriatric rehabilitation. Findings This guidance addresses general requirements for post-acute COVID-19 geriatric rehabilitation and critical aspects for quality assurance during the COVID-19 pandemic. Furthermore, the guidance describes relevant care processes and procedures divided in five topics: patient selection; admission; treatment; discharge; and follow-up and monitoring. Message This guidance is designed to provide support to care professionals involved in the geriatric rehabilitation treatment of post-acute COVID-19 patients.Public Health and primary careGeriatrics in primary car

Collisional and Radiative Processes in Optically Thin Plasmas

Most of our knowledge of the physical processes in distant plasmas is obtained through measurement of the radiation they produce. Here we provide an overview of the main collisional and radiative processes and examples of diagnostics relevant to the microphysical processes in the plasma. Many analyses assume a time-steady plasma with ion populations in equilibrium with the local temperature and Maxwellian distributions of particle velocities, but these assumptions are easily violated in many cases. We consider these departures from equilibrium and possible diagnostics in detail

Microflares and the Statistics of X-ray Flares

This review surveys the statistics of solar X-ray flares, emphasising the new views that RHESSI has given us of the weaker events (the microflares). The new data reveal that these microflares strongly resemble more energetic events in most respects; they occur solely within active regions and exhibit high-temperature/nonthermal emissions in approximately the same proportion as major events. We discuss the distributions of flare parameters (e.g., peak flux) and how these parameters correlate, for instance via the Neupert effect. We also highlight the systematic biases involved in intercomparing data representing many decades of event magnitude. The intermittency of the flare/microflare occurrence, both in space and in time, argues that these discrete events do not explain general coronal heating, either in active regions or in the quiet Sun.Comment: To be published in Space Science Reviews (2011

Quantificação de fatores de crescimento na pele de equinos tratada com plasma rico em plaquetas

O plasma rico em plaquetas (PRP) é um produto derivado da centrifugação do sangue total, sendo rico em fatores bioativos, como os de crescimento. Apesar da ampla utilização em processos cicatriciais, há controvérsia sobre a eficácia da terapia na cicatrização cutânea. O objetivo desse estudo foi quantificar e comparar a concentração dos fatores TGF-β1 e PDGF-BB no PRP, plasma sanguíneo e pele, durante diferentes fases do processo de cicatrização da pele tratada ou não com PRP. Foram utilizados sete equinos machos castrados, mestiços, hígidos, com idade entre 16 e 17 (16,14±0,63) anos. Três lesões em formato quadrangular (6,25cm²) foram produzidas cirurgicamente nas regiões glúteas direita e esquerda de todos os animais. Doze horas após indução das feridas, 0,5mL do PRP foi administrado em cada uma das quatro extremidades das feridas de uma das regiões glúteas (Grupo tratado = GT), escolhida aleatoriamente. A região contralateral foi utilizada como controle (GC). As feridas foram submetidas à limpeza diária com água Milli Q, e amostras foram obtidas mediante biópsias realizadas com Punch de 6mm. Foram obtidas seis biópsias de pele, sendo a primeira realizada logo após a produção da ferida (T0), e as demais com 1 (T1) 2 (T2) 7 (T3) e 14 (T4) dias após a indução da lesão. A sexta biópsia (T5) foi obtida após completo fechamento da pele, que ocorreu aproximadamente aos 37 dias (36,85±7,45, GC; 38,85±6,46, GT). Também foram obtidas amostras de sangue com EDTA em todos os tempos mencionados. A quantificação dos fatores de crescimento TGF-β1 e PDGF-BB na pele, PRP e plasma sanguíneo foi realizada pela técnica ELISA. Os dados foram analisados estatisticamente pelo teste t, correlação de Pearson e regressão, utilizando nível de significância de 5%. Não houve diferença entre os grupos, nos valores dos dois fatores de crescimento mensurados na pele, nos diferentes tempos. Também não houve correlação entre a quantidade dos fatores de crescimento presentes na pele e no plasma. Por outro lado, correlação positiva foi observada entre PRP e pele no grupo tratado, para os fatores de crescimento TGF-β1 (r=0,31) e PDGF-BB (r=0,38), bem como entre ambos os fatores de crescimento presentes no PRP (r=0,81). Considerando as concentrações dos fatores de crescimento no T0, os maiores valores cutâneos (p<0,05) do TGF-β1, em ambos os grupos, ocorreram nos tempos T3 e T5. Valores mais elevados (p<0,05) do PDGF-BB ocorreram no T4 (GT) e T5 (GC). No plasma não houve alteração nas concentrações desses fatores em relação ao T0, o que sugere que o PRP não acarreta efeito sistêmico, quando os procedimentos adotados na presente pesquisa são utilizados. A administração local de PRP no volume estudado, 12 h após indução cirúrgica de ferida cutânea na região glútea de equinos não ocasiona maiores concentrações dos fatores de crescimento TGF-β1 e PDGF-BB no plasma sanguíneo e pele, durante o processo de cicatrização

Doença do enxerto contra hospedeiro pós-transfusional-guia para irradiação gama de hemocomponentes Transfusion-associated graft-versus-host disease-guideline on gamma irradiation of blood components

A doença enxerto contra hospedeiro transfusional (DECHT) é síndrome rara e geralmente fatal. É caracterizada por febre, eritema cutâneo, náuseas, vômitos, diarréia, hepatite e pancitopenia. Pode ocorrer em pacientes com imunossupressão severa e em pacientes imunocompetentes após a transfusão de hemocomponente celular de doador homozigoto para proteínas HLA às quais o receptor é heterozigoto. O diagnóstico é feito pelo quadro clínico e exame histopatológico da pele. A gamaglobulina antitimocítica associada a altas doses de corticosteróides é a terapêutica mais empregada. O desconhecimento da síndrome, o retardo no diagnóstico, o curso rápido e a ausência de resposta ao tratamento estão relacionados à má evolução dos pacientes. A melhor forma de abordagem da DECHT é a prevenção através da irradiação gama dos hemocomponentes. A dose necessária para completa inativação dos linfócitos T é de 2500 cGy. A principal alteração decorrente da irradiação é o aumento da concentração de potassio nos concentrados de hemácias. Os filtros de leucócitos não previnem o desenvolvimento da DECHT e a irradiação não previne a aloimunizaçao e as reaçoes transfusionais. Apenas hemocomponentes celulares como sangue total, concentrado de hemácias, concentrado de plaquetas e concentrado de granulócitos, necessitam ser irradiados. Devem ser irradiados os hemocomponentes para transfusão entre familiares, transfusões HLA compatíveis, pacientes submetidos a transplante de medula óssea, portadores de doença de Hodgkin, pacientes tratados com análogos da purina, transfusões intra-útero, recém nascidos pré-termo e pacientes com síndrome de imunodeficiência congênita. É recomendável a irradiação de hemocomponentes destinados a pacientes com doenças neoplásicas quando submetidos a protocolos de quimioterapia agressivos.<br>Transfusion-associated graft-versus-host disease (TA-GVHD) is a rare and usuailly fatal syndrome. Clinical manifestations are fever, maculopapular skin rash, nausea, vomiting, diarrhea, hepatitis and pancytopenia owing to bone marrow hypoplasia. lt can occur in recipients with severe immunossuppression and in immunocompetent recipients after transfusion of ceillular components from HLA homozygous donor to recipients heterozygous for that HLA haplotype. The diagnosis is made by clinical manifestation and skin biopsy. Antithymocyte globulin and high dose systemic corticosteroids are both the most used therapy. The back of knowledge about this syndrome, the rapid evolution and the absence of treatement response are related to patients bad evolution. Gamma irradiation of blood products has been the mainstay of TA-GVHD prevention. Dose of 2500 cGy is required to completly inactivate T cells. lrradiation damage red cells membrane and the red celis units can not be storage for long time after irradiation. High potassium levels is the mainly change in red cells units.White cell-reduction filters do not prevent TA-GVHD and gamma irradiation does not prevent alloimmunization or blood reactions. Oniy cellular components like whole blood, red cells, platelets and granulocytes need be irradiated. Ali blood components should be irradiated to: first or second-degree relatives, patients need HLA-matched platelets, recipients of allogeneic or autologous bone marrow transplantation, patients with Hodgkin's disease, patients treated with purine analogue drugs, intrauterine transfusions, pre-term infants and when congenítal immunodeficiency states is suspected. lt is recomended irrradiated blood to patients with neoplastic disease when they receive intensive chemoterapy