293 research outputs found
Mixed initial conditions to estimate the dynamic critical exponent in short-time Monte Carlo simulation
We explore the initial conditions in short-time critical dynamics to propose
a new method to evaluate the dynamic exponent z. Estimates are obtained with
high precision for 2D Ising model and 2D Potts model for three and four states
by performing heat-bath Monte Carlo simulations.Comment: Latex paper, 2 eps figure
Alcoolismo, tabagismo e carcinoma epidermóide de terço médio do esÎfago: estudo tipo caso-controle
A case-control study was planned to show a possible association between middle third squamous esophageal cancer and the use of alcohol and tobacco. The study was conducted at the outpatient department of the University Hospital, Medical School of RibeirĂŁo Preto during the years 1980/1981. Among 25,661 patients, 21 were diagnosed as middle third squamous esophageal cancer and 57 were chosen as controls. The controls were selected in a 3:1 ratio. The following item were matched: age, sex, residence, race, socioeconomic status, profession and use of tobacco and alcohol. An association between middle third squamous esophageal cancer and alcoholism was found (relative risk = 26.7) (p ; 0.10).Para verificar uma possĂvel associação entre o carcinoma epidermĂłide de terço mĂ©dio de esĂŽfago e os hĂĄbitos de beber e fumar, foi realizado um estudo tipo caso-controle no Hospital das ClĂnicas de RibeirĂŁo Preto, no perĂodo de agosto de 1980 a outubro de 1981. Entre 25.661 pacientes atendidos nesta instituição, 21 tiveram o diagnĂłstico deste tipo de neoplasia. Eles foram considerados casos e pareados individualmente com 57 controles (razĂŁo de pareamento de 1:3) em relação Ă s variĂĄveis: sexo, idade, cor, procedĂȘncia, residĂȘncia, profissĂŁo, nĂvel sĂłcio-econĂŽmico e o hĂĄbito de beber ou fumar. Foi encontrada associação estatisticamente significativa entre o carcinoma epidermĂłide de terço mĂ©dio do esĂŽfago e o alcoolismo, com risco relativo de 26,7. Este valor Ă© maior que os encontrados em outras partes do mundo, referentes Ă associação com o cĂąncer de esĂŽfago em geral. Em relação ao tabagismo, nĂŁo foi encontrada associação significativa: o risco relativo obtido foi de 1,9
Gasto energético após 2 ou 3 horas de cirurgia eletiva
Energy expenditure was measured by indirect calorimetry in 17 adult patients (8 women and 9 men) before surgery, 4 hours immediately after surgery , and 24 hours late after surgery in patients undergoing elective surgery of small-to-medium scope. MATERIAL AND METHODS: The total duration of surgery ranged from 2 to 3 hours. Repeated measures were performed on the same patient, so that each patient was considered to be his/her own control. All patients received a 5% dextrose solution (2000 mL/day) throughout the postoperative period. RESULTS: Men showed a reduction in CO2 production during the immediately after surgery period (257±42 mL/min) compared to before surgery (306±48 mL/min) and late after surgery (301±45 mL/min); this reduction was not observed in women. Energy expenditure was also lower in men during immediately after surgery (6.6 kJ/min). None of the other measurements, including substrate oxidation, showed significant differences. CONCLUSION: Therefore, elective surgery itself cannot be considered an important trauma that would result in increased energy expenditure. According to this study, it is not necessary to prescribe an energy supply exceeding basal expenditure during the immediate after-surgery period. The present results suggest that the energy supply prescribed during the postoperative period after elective surgery of small-to-medium scope should not exceed 5-7 kJ/min, so the patient does not receive a carbohydrate overload from energy supplementation.A resposta metabĂłlica ao trauma cirĂșrgico ocorre imediatamente apĂłs a cirurgia e recomenda-se que a oferta calĂłrica, nesta situação, seja igual ao metabolismo basal acrescido de 20-30%, considerado fator de injĂșria. No entanto, nĂveis elevados de glicemia e aumento na produção de CO2 sĂŁo freqĂŒentemente observados nestas ocasiĂ”es . OBJETIVO: O principal objetivo do presente estudo foi medir o gasto energĂ©tico basal, o gasto energĂ©tico imediatamente e 24 horas apĂłs cirurgia eletiva; comparar o gasto e consumo energĂ©tico entre estes diferentes perĂodos, assim como, procurar diferenças entre o homem e a mulher. MATERIAL E MĂTODO: O mĂ©todo utilizado para avaliar o gasto energĂ©tico de 17 pacientes adultos (8 mulheres e 9 homens) foi por meio de calorimetria indireta, nos perĂodos basal, imediatamente apĂłs cirurgia e 24 horas apĂłs cirurgia . O tempo cirĂșrgico variou entre 2 e 3 horas. Este foi um estudo pareado , sendo portanto cada paciente considerado controle de si prĂłprio. RESULTADOS: Todos os pacientes receberam no perĂodo pĂłs-cirĂșrgico solução de dextrose a 5% (2000 mL/dia).Os resultados encontrados nos homens mostraram diminuição da produção de CO2 no perĂodo imediatamente apĂłs cirurgia (257±42 mL/min) quando comparado ao gasto energĂ©tico basal (306±48 mL/min) e 24horas apĂłs a cirurgia (301±45 mL/min). O mesmo nĂŁo ocorreu com as mulheres. O gasto energĂ©tico dos homens tambĂ©m foi menor no imediatamente apĂłs a cirurgia (6,6 kJ/min). Todas outras medidas, incluindo oxidação do substrato, nĂŁo mostraram diferenças significativas. CONCLUSĂO: Desta maneira, a cirurgia eletiva nĂŁo pode ser considerado trauma importante que resulte em aumento do gasto energĂ©tico. Conclui-se que a prescrição energĂ©tica no pĂłs-cirĂșrgico, de cirurgias eletivas de mĂ©dio e pequeno porte, seja equivalente 5-7 kJ/min, evitando desta maneira que o paciente receba sobregarca de hidratos de carbono
Universality and scaling study of the critical behavior of the two-dimensional Blume-Capel model in short-time dynamics
In this paper we study the short-time behavior of the Blume-Capel model at
the tricritical point as well as along the second order critical line. Dynamic
and static exponents are estimated by exploring scaling relations for the
magnetization and its moments at early stage of the dynamic evolution. Our
estimates for the dynamic exponents, at the tricritical point, are and .Comment: 12 pages, 9 figure
Global persistence exponent of the two-dimensional Blume-Capel model
The global persistence exponent is calculated for the
two-dimensional Blume-Capel model following a quench to the critical point from
both disordered states and such with small initial magnetizations.
Estimates are obtained for the nonequilibrium critical dynamics on the
critical line and at the tricritical point.
Ising-like universality is observed along the critical line and a different
value is found at the tricritical point.Comment: 7 pages with 3 figure
Short telomeres in ESCs lead to unstable differentiation
SummaryFunctional telomeres are critical for stem cell proliferation; however, whether they are equally important for the stability of stem cell differentiation is not known. We found that mouse embryonic stem cells (ESCs) with critically short telomeres (Tertâ/â ESCs) initiated normal differentiation after leukemia inhibitory factor (LIF) withdrawal but, unlike control ESCs, failed to maintain stable differentiation when LIF was reintroduced to the growth medium. Tertâ/â ESCs expressed higher levels of Nanog and, overall, had decreased genomic CpG methylation levels, which included the promoters of Oct4 and Nanog. This unstable differentiation phenotype could be rescued by telomere elongation via reintroduction of Tert, via suppression of Nanog by small hairpin RNA (shRNA) knockdown, or via enforced expression of the de novo DNA methyltransferase 3b. These results demonstrate an unexpected role of functional telomeres in the genome-wide epigenetic regulation of cell differentiation and suggest a potentially important role of telomere instability in cell fate during development or disease
Parenteral nutrition support: prescriptions and follow up
The introduction of total parenteral nutrition support in the therapy of hospitalized patients has necessitated the development of a rig guidelines lo promote coast containment and optimal patient care. It is very kwon nowadays the impact of nutrition support team, which members include one or more physicians, nurses and pharmacists upon this practice, such as, the potential benefits derived from a particular mode of providing specifics parenteral feeding formulations and high performance in the assessment of nutrient intake of the hospitalized patient. The main purpose of this study is to present the Total Parenteral Nutrition Committee of the Clinics Hospital of RibeirĂŁo Pretoâs report concerning the specific parenteral feeding formulations to be used in the hospitalized patient.O suporte nutricional, na terapĂȘutica de pacientes hospitalizados, requer o desenvolvimento de princĂpios que determinarĂŁo a melhor assistĂȘncia nutricional, associada ao menor custo do procedimento. Reconhece-se, atualmente, o impacto causado pela formação de equipes ou comissĂ”es multidisciplinares de suporte nutricional parenteral, formadas por mĂ©dicos, enfermeiros e farmacĂȘuticos, sobre a racionalização da terapĂȘutica nutricional, como a escolha de nutrientes especĂficos e a padronização das formulaçÔes nutritivas. O objetivo deste trabalho se relaciona com o uso de nutrição parenteral total, no Hospital das ClĂnicas de RibeirĂŁo Preto, incluindo indicaçÔes, formulaçÔes, efeitos colaterais e benefĂcios. Paralelamente, Ă© apresentada a padronização das formulaçÔes nutritivas parenterais, efetuada pela ComissĂŁo de Nutrição Parenteral do Hospital das ClĂnicas de RibeirĂŁo Preto, a ser utilizada nos pacientes hospitalizados, que necessitem de terapia nutricional parenteral
A Prospective Randomized Trial of Either Famotidine or Pantoprazole for the Prevention of Bleeding after Endoscopic Submucosal Dissection
Endoscopic submucosal dissection (ESD) has been reported to have a higher bleeding rate than conventional methods. However, there are few reports on whether a proton pump inhibitor or a histamine2-receptor antagonist is the more effective treatment for preventing bleeding after ESD. In a prospective trial, patients undergoing ESD due to gastric adenoma or adenocarcinoma were randomly assigned to pantoprazole or famotidine. Both drugs were given intravenously for the first 2 days, thereafter by mouth. Eighty-five in the pantoprazole group and 79 in the famotidine group were included for analysis. Primary outcome measure was the delayed bleeding rate. Clinical characteristics were not different between the two groups. The delayed bleeding rate was significantly lower in the pantoprazole group compared with the famotidine group (3.5% vs. 12.7%, p=0.031). On multivariate analysis, the preventive use of pantoprazole (relative hazard: 0.220, 95% CI: 0.051- 0.827, p=0.026) and the specimen size (â„34 mm, relative hazard: 4.178, 95% CI: 1.229-14.197, p=0.022) were two independent factors predictive of delayed bleeding. There were no significant differences in en bloc and complete resection rate between the two groups. In conclusion, pantoprazole is more effective than famotidine for the prevention of delayed bleeding after ESD
Long-duration gamma-ray emissions from 2007 and 2008 winter thunderstorms
The Gamma-Ray Observation of Winter THunderclouds (GROWTH) experiment,
consisting of two radiation-detection subsystems, has been operating since 2006
on the premises of Kashiwazaki-Kariwa nuclear power plant located at the
coastal area of Japan Sea. By 2010 February, GROWTH detected 7 long-duration
-rays emissions associated with winter thunderstorms. Of them, two
events, obtained on 2007 December 13 and 2008 December 25, are reported.On both
occasions, all inorganic scintillators (NaI, CsI, and BGO) of the two
subsystems detected significant gamma-ray signals lasting for >1 minute.
Neither of these two events were associated with any lightning. In both cases,
the gamma-ray energy spectra extend to 10 MeV, suggesting that the detected
gamma-rays are produced by relativistic electrons via bremsstrahlung. Assuming
that the initial photon spectrum at the source is expressed by a power-law
function,the observed photons can be interpreted as being radiated from a
source located at a distance of 290-560 m for the 2007 event and 110-690 m for
the 2008 one, both at 90% confidence level.Employing these photon spectra, the
number of relativistic electrons is estimated as 10^9 - 10^{11}. The estimation
generally agrees with those calculated based on the relativistic runaway
electron avalanche model. A GROWTH photon spectrum, summed over 3 individual
events including the present two events and another reported previously, has
similar features including a cut-off energy, to an averaged spectrum of
terrestrial gamma-ray flashes.Comment: 46 pages, 13 figures, accepted for publication in JGR-Atmospher
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