3,192 research outputs found
Effects of rituximab-based B-cell depletion therapy on skin manifestations of lupus erythematosus--report of 17 cases and review of the literature
Cutaneous manifestations occur frequently in systemic lupus erythematosus (SLE) and are pathognomonic in subacute-cutaneous lupus erythematosus (SCLE) and chronic cutaneous lupus erythematosus (CCLE). Although B-cell depletion therapy (BCDT) has demonstrated efficacy in SLE with visceral involvement, its usefulness for patients with predominant skin manifestations has not been fully established. In this single-centre, retrospective study 14 consecutive SLE, one CCLE and two SCLE patients with recalcitrant skin involvement were treated with 2 × rituximab 1 g, and 1 × cyclophosphamide 750 mg. Six months after BCDT, nine of 17 (53%) patients were in complete (CR) or partial remission (PR). Relapses occurred in 12 patients (71%) at a mean time of 10 ± 1.8 months after BCDT. A second cycle of BCDT achieved a more sustained remission in seven of nine patients (78%) lasting for a mean time of 18.4 ± 2.7 months. Minor adverse events were experienced by three patients. Mean follow-up was 30 months. Our own results and the literature review demonstrate that BCDT based on rituximab is well tolerated and may be effective for cutaneous lesions of lupus erythematosus. Randomized controlled trials are necessary to further evaluate the value of BCDT for this group of patients
Experimentos, modelagem, simulação e controle de uma operação contÃnua de secagem e resfriamento de soja (Glycine max) extrusada
Orientador : Prof. Dr. Everton Fernando ZanoeloDissertação (mestrado) - Universidade Federal do Paraná, Setor de Tecnologia, Programa de Pós-Graduação em Engenharia de Alimentos. Defesa: Curitiba, 15/06/2012Bibliografia: fls. 60-65ResumoResumo: A secagem e resfriamento simultâneos em esteiras móveis é uma operação preliminar tipicamente aplicada em indústrias de processamento de soja com o objetivo de reduzir a umidade e temperatura do leito alimentado no extrator de óleo e proteÃna. Embora estes parâmetros sejam importantes para propósitos de segurança e otimização de extração, esquemas para o controle automático destas variáveis são extremamente limitados ou inexistentes na literatura. Neste sentido, a presente investigação sugere a utilização de um controlador PID para manipular a velocidade da esteira a fim de manter a temperatura dos flocos de soja expandidos na saÃda do secador-resfriador em 61,0 ºC sem exceder o intervalo de 0,099 a 0,123 (base seca) de umidade de descarga do produto. Respostas das variáveis investigadas em malha aberta e fechada frente a perturbações arbitrárias na umidade (0,142-0,156 b.s.), e temperatura (103,2-109,8 °C) de alimentação do sólido, assim como na temperatura (52,6-53,4 °C) e umidade média do ar (0,0663-0,0703 kg kg-1) confirmaram a validade da estratégia de controle proposta. Um modelo dinâmico representado por um sistema de duas equações diferencias parciais obtido por um balanço de energia e de massa para o soluto no leito de sólidos foi empregado como secador-resfriador virtual. A consistência do modelo foi verificada por comparação entre resultados experimentais e calculados de umidade e temperatura de soja extrusada na descarga de um secador-resfriador contÃnuo de grande porte operando em tÃpicas condições industriais. Os coeficientes efetivos de transporte de massa e calor requeridos para solução numérica do modelo dinâmico pelo método das diferenças finitas foram ajustados a um conjunto de dados cinéticos de secagem e resfriamento obtidos em um secador-resfriador batelada de laboratório a 30, 40 e 50 ºC. A técnica ISE e o método simplex de otimização foram aplicados para determinar os parâmetros do controlador requeridos para um controle estável do processo.Abstract: Simultaneous drying and cooling in conveyor-belts is a preliminary operation typically applied in the soybean processing industry to reduce the moisture content and temperature of the full-fat flakes fed to the oil and protein extractor. Although these parameters are important to have a safe and optimal process of extraction, limited or even inexistent schemes for their control are available. To deal with this drawback, the current investigation suggests the use of a PID controller to manipulate the speed of the conveyor-belt in order to keep the temperature of the flakes in the discharge of the dryer-cooler close to 61.0 ºC without exceeding the acceptable outlet moisture content range from 0.099 to 0.123 in dry basis. Closed-loop responses for the controlled variables when considering simultaneous arbitrary disturbances on inlet moisture content (0.142-0.156 d.b.), inlet temperature of the solid (103.2-109.8 °C), average air temperature (52.6-53.4 °C) and absolute humidity (0.0663-0.0703 kg kg-1) confirmed the reliability of the current strategy of control. A dynamic model represented by a system of two partial differential equations obtained by an energy and mass balance for the solute in the bed was used as a virtual conveyor-belt dryer-cooler. The consistency of this model was checked by a comparison between experimental and calculated results of moisture content and temperature at the exit of a size-scale dryer-cooler of soybean flakes at typical industrial operating conditions. The effective coefficients of mass and heat transfer required to numerically solve the model by using the finite difference method were tuned on a set of kinetic drying and cooling curves obtained in a batch dryer-cooler. The ISE technique and simplex method of optimization were used to tune the set of PID parameters in which process control is stable
Seguro de crédito: a crise econômica e o impacto nas operações de crédito
O presente estudo tem por objetivo apresentar uma fundamentação teórica sobre a modalidade de seguro de crédito, analisando sua aplicabilidade e explorando os impactos de sua operação no mercado de crédito. É sabido que a concessão de crédito caracteriza objeto de suma importância aos administradores de instituições financeiras, uma vez que, trata-se de operação em condições de risco. A decisão de assumir esse risco é constantemente tomada dentro de um ambiente de mudanças no mercado econômico, na polÃtica e no mercado financeiro, dentre outras tantas, e todas elas alteram, a todo momento, as condições de risco e incerteza. Desta forma, o seguro de crédito torna-se um importante instrumento de proteção ao risco para a operação de concessão de crédito praticada pelas instituições financeiras, principalmente, em tempos de crise econômica. Este trabalho buscou construir uma análise dos conceitos da modalidade de seguros abordada, demonstrando sua aplicabilidade conceitual e prática e, destacando sua operação em momentos de crise, com a intenção de aperfeiçoar conhecimentos acerca da atividade profissional à qual a autora está ligada e estruturar bases para futuras pesquisas. Para tanto, realizou-se revisão de artigos e trabalhos acadêmicos sobre o assunto, além de consulta à s normativas disponibilizadas pela autarquia federal de seguros, Superintendência de Seguros Privados (SUSEP). Ao final da pesquisa, concluiu-se que existe uma tendência de crescimento de demanda para a modalidade de seguro de crédito na indústria de Seguros, impulsionada, dentre outros fatores, pelo impacto negativo no perfil de crédito causado pela recessão econômica e por alterações nas regras regulatórias das instituições financeiras que vigorarão em breve
A discussion about a start-up procedure of a doubly-fed induction generator system
The present work proposes a start-up procedure for a doubly-fed induction generator (DFIG) driven by a wind turbine. In the DFIG topology the stator is connected direct to the grid while the rotor is connected to a back-to-back converter. This structure requires some care during grid synchronization to avoid undesired overloads. The main goal of a start-up procedure is to reduce the stresses on the electrical and mechanical components during synchronization. In this work, it is achieved by equalization among the induced stator voltage, the voltage over the filter capacitor and the grid voltage. A phase-locked-loop (PLL) computes the grid voltage phase displacement required for the system control orientation and synchronization procedures.
Previous to the starting-up, the output currents set-points of the grid-side converter and rotor-side converter are computed in order to produce the same grid voltage over the filter capacitors and on the stator terminals. The whole procedure is summarized in seven different steps: turbine acceleration by the pitch control, DC-link pre-charge; initialization of the filter current controllers; filter synchronization; DC-Link voltage adjust; rotor current controllers' initialization and stator synchronization. The proposed start-up procedure was tested in a 4Â kW test bench and the description of each step as well as simulation and experimental results are presented throughout the paper.reviewe
From social context and resilience to performance through job satisfaction: A multilevel study over time
Giving the crucial role of organizational context in shaping individual attitudes and behaviors at work, in this research we studied the effects of collective work-unit Perceptions of Social Context (PoSC) on individual work resilience and two key individual outcomes: job satisfaction and job performance as rated by the supervisor. We theorized that collective PoSC act as antecedents of individual variables, and that individual job satisfaction mediates the relationship between collective PoSC and job performance, and between work resilience and job performance over time. A sample of 305 white-collar employees, clustered in 67 work-units, participated in the study. Hierarchical linear modeling highlighted that collective PoSC are significant related to individual work resilience. Moreover, results showed that individual job satisfaction fully mediates the relationship between collective PoSC and individual job performance and the relationship between individual work resilience and individual job performance. At a practical level, results suggest that interventions on collective PoSC may increase work resilience, job satisfaction and job performance over time at the individual level
Use of crushing residue as nutrients source in the cocoa seedlings development in Medicilândia – PA
The use of milled rocks has been postulated as an efficient way to provide nutrients to the plants. The objective of this work was to evaluate the cocoa seedlings agronomic performance in different Diabase Penatecaua powder treatments. The study comprehends the following phases: i) involved waste characterization, ii) treatments definition and sampling; iii) monitoring and evaluation; iv) systematization and results discussion. The experiment was realized with cocoa seedlings germinated in commercial organic substrate in the period from July to September 2019. The used rock dust was extracted at Km 85, Transamazônica highway, Medicilândia municipality – Pa. The extraction area lithology is formed by igneous rocks of Diabase Penatecaua. The experimental delineation was entirely randomized, with four repetitions per treatment, being them respectively in the dosages 0, 25, 50 and 75 (g / plant), being 16 plants per block, totaling 64 plants, and their irrigation done manually in the first hours of the day. Therefore, the results showed that the dosages were absorbed by the cocoa seedlings according to the plant\u27s need allied to pH balance, which was caused by good nutritional cycling with the organic matter high rate present in the commercial substrate when in contact with the Diabase Penatecaua powder worked granulometry. However, the experiment time wasn’t enough to obtain statistically a significant difference. Thus, it is necessary that new studies be done aiming the temporal deepening of the studied doses for the culture
Radius Stabilization by Two-Loop Casimir Energy
It is well known that the Casimir energy of bulk fields induces a non-trivial
potential for the compactification radius of higher-dimensional field theories.
On dimensional grounds, the 1-loop potential is ~ 1/R^4. Since the 5d gauge
coupling constant g^2 has the dimension of length, the two-loop correction is ~
g^2/R^5. The interplay of these two terms leads, under very general
circumstances (including other interacting theories and more compact
dimensions), to a stabilization at finite radius. Perturbative control or,
equivalently, a parametrically large compact radius is ensured if the 1-loop
coefficient is small because of an approximate fermion-boson cancellation. This
is similar to the perturbativity argument underlying the Banks-Zaks fixed point
proposal. Our analysis includes a scalar toy model, 5d Yang-Mills theory with
charged matter, the examination of S^1 and S^1/Z_2 geometries, as well as a
brief discussion of the supersymmetric case with Scherk-Schwarz SUSY breaking.
2-Loop calculability in the S^1/Z_2 case relies on the log-enhancement of
boundary kinetic terms at the 1-loop level.Comment: 18 pages, 2 figures, uses axodraw, references adde
Implicating Self-Control in the Mechanism by which Implementation Intentions Reduce Stress-Induced Unhealthy Eating: a Comment on O’Connor et al.
ANN-based energy reconstruction procedure for TACTIC gamma-ray telescope and its comparison with other conventional methods
The energy estimation procedures employed by different groups, for
determining the energy of the primary -ray using a single atmospheric
Cherenkov imaging telescope, include methods like polynomial fitting in SIZE
and DISTANCE, general least square fitting and look-up table based
interpolation. A novel energy reconstruction procedure, based on the
utilization of Artificial Neural Network (ANN), has been developed for the
TACTIC atmospheric Cherenkov imaging telescope. The procedure uses a 3:30:1 ANN
configuration with resilient backpropagation algorithm to estimate the energy
of a -ray like event on the basis of its image SIZE, DISTANCE and
zenith angle. The new ANN-based energy reconstruction method, apart from
yielding an energy resolution of 26%, which is comparable to that of
other single imaging telescopes, has the added advantage that it considers
zenith angle dependence as well. Details of the ANN-based energy estimation
procedure along with its comparative performance with other conventional energy
reconstruction methods are presented in the paper and the results indicate that
amongst all the methods considered in this work, ANN method yields the best
results. The performance of the ANN-based energy reconstruction has also been
validated by determining the energy spectrum of the Crab Nebula in the energy
range 1-16 TeV, as measured by the TACTIC telescope.Comment: 23pages, 9 figures Accepted for publication in NIM
Magnetic fields in solar plage regions: insights from high-sensitivity spectropolarimetry
Plage regions are patches of concentrated magnetic field in the Sun's
atmosphere where hot coronal loops are rooted. While previous studies have shed
light on the properties of plage magnetic fields in the photosphere, there are
still challenges in measuring the overlying chromospheric magnetic fields,
which are crucial to understanding the overall heating and dynamics. Here, we
utilize high-sensitivity, spectropolarimetric data obtained by the four-meter
Daniel K. Inouye Solar Telescope (DKIST) to investigate the dynamic environment
and magnetic field stratification of an extended, decaying plage region. The
data show strong circular polarization signals in both plage cores and
surrounding fibrils. Notably, weak linear polarization signals clearly
differentiate between plage patches and the fibril canopy, where they are
relatively stronger. Inversions of the Ca II 8542 spectra show
an imprint of the fibrils in the chromospheric magnetic field, with typical
field strength values ranging from 200-300 G in fibrils. We confirm the
weak correlation between field strength and cooling rates in the lower
chromosphere. Additionally, we observe supersonic downflows and strong velocity
gradients in the plage periphery, indicating dynamical processes occurring in
the chromosphere. These findings contribute to our understanding of the
magnetic field and dynamics within plages, emphasizing the need for further
research to explore the expansion of magnetic fields with height and the
three-dimensional distribution of heating rates in the lower chromosphere.Comment: 17 pages, 8 figures, accepted for publication in ApJ
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