On the optimum distribution of enzyme feed in a cascade of CSTR's performing an enzyme-catalyzed reaction with deactivation

A search for the optimum fractional distribution of an enzyme-rich stream to the various reactors of a cascade of CSTR's was implemented. A theoretical analysis, laid out in dimensionless form and based on the assumptions that the system is operated under steady state conditions, the enzyme undergoes first order deactivation, and the reaction catalyzed by the enzyme follows Michaelis-Menten kinetics, is reported. The objective function utilised is the minimisation of the overall volume of the cascade, and analytical expressions are obtained for the concentration of active enzyme and substrate in the outlet stream from each reactor. It is found that the best option is to add the whole enzyme-rich stream to the first reactor in the cascade irrespective of the operating and kinetic parameters of the system

Meissner state in finite superconducting cylinders with uniform applied magnetic field

We study the magnetic response of superconductors in the presence of low values of a uniform applied magnetic field. We report measurements of DC magnetization and AC magnetic susceptibility performed on niobium cylinders of different length-to-radius ratios, which show a dramatic enhance of the initial magnetization for thin samples, due to the demagnetizing effects. The experimental results are analyzed by applying a model that calculates the magnetic response of the superconductor, taking into account the effects of the demagnetizing fields. We use the results of magnetization and current and field distributions of perfectly diamagnetic cylinders to discuss the physics of the demagnetizing effects in the Meissner state of type-II superconductors.Comment: Accepted to be published in Phys. Rev. B; 15 pages, 7 ps figure

Atypical enteropathogenic Escherichia coli (aEPEC) in children under five years old with diarrhea in Quito (Ecuador)

Enteropathogenic Escherichia coli (EPEC) remain one the most important pathogens infecting children and they are one of the main causes of persistent diarrhea worldwide. In this study, we have isolated EPEC from 94 stool samples of children under five years old with diarrheal illness in the area of Quito (Ecuador), and we have determined the occurrence of the two subtypes of EPEC, typical EPEC (tEPEC) and atypical (aEPEC), by PCR amplification of the genes eae (attaching and effacing) and bfp (bundle- forming pilus). Typical EPEC is positive for eae and bfp genes while aEPEC is positive only for eae. Our results suggest that aEPEC is the most prevalent subtype in Quito (89.36 %), while subtype tEPEC is less prevalent (10.64 %). [Int Microbiol 19(3):157-160 (2016)]Keywords: Escherichia coli · atypical EPEC · genes eae and bfp · diarrhea in children · Quito (Ecuador

Post-fire management of cork oak forests

28 páginas, 11 figuras.This chapter concerns the ecology and post-fire management of cork oak forests. It starts with a short overview of ecological and socio-economic context, continuing with an introduction on the cork oak post-fire regeneration strategies and the main factors affecting tree responses. Several post-fire management issues and alternatives, such as tree logging, assisting natural regeneration, reforestation, cork harvesting and pruning, or protecting against herbivory, are also presented and discussed.To all people who contributed in some way to the contents of this chapter, with special thanks to Francisco Rego, Paulo Fernandes and Thomas Curt. To Fundação para a Ciência e a Tecnologia (PhD grant SFRH/BD/65991/2009), FFP (project Recuperação de Áreas Ardidas), EU (COST FP0701 and TRANZFOR), and the Spanish government (project VARQUS, CGL2004-4325/BOS).Peer reviewe

Thermal fluctuations of a quantized massive scalar field in Rindler background

Thermal fluctuations for a massive scalar field in the Rindler wedge are obtained by applying the point-splitting procedure to the zero temperature Feynman propagator in a conical spacetime. Renormalization is implemented by removing the zero temperature contribution. It is shown that for a field of non vanishing mass the thermal fluctuations, when expressed in terms of the local temperature, do not have Minkowski form. As a by product, Minkowski vacuum fluctuations seen by an uniformly accelerated observer are determined and confronted with the literature.Comment: 10 pages; Latex fil

EFFECTS OF grape powder SUPPLEMENTATION ON INFLAMMATION IN hemodialysis patients.

Polyphenols and antioxidants anti-inflammatory have been considered pharmacological agents to combat oxidative stress in chronic diseases due the reduction in the formation of free radicals (FR). Hemodialysis (HD) patients have an imbalance between oxidant and antioxidant activity, with increased levels of FR and consequently an increase of lipid peroxidation, thereby raising the risk for cardiovascular disease (CVD). The beneficial health effects of grape juice or red wine for these patients have been attributed to the antioxidant activity of its polyphenols. Then, this study aimed to evaluate the effects of grape powder supplementation on inflammation and glutathione peroxidase levels in hemodialysis (HD) patients. Thirty-two HD patients from CIN, RJ, Brazil were studied and randomly into two groups: placebo group- PG (16 patients, 9 men, 52.7 ± 13.7 yrs) and experimental group EG (16 patients, 9 men, 53.0 ± 9.8 yrs). Each patient received 12g/day of powder grape with grape jelly or only grape jelly (placebo) during 5 weeks. The lipid profile, C-reactive protein (CRP) levels and glutathione peroxidase (GPx) activity were evaluated before and after supplementation (Table). The data suggest that the consumption of grape powder was effective to increase the activity of GPx and decreasing the progression the inflammation. Thus, our results indicate that grape powder plays an important role as an antioxidant agent in HD patients.Placebo GroupExperimental GroupBeforeAfterBeforeAfterCRP (mg/mL)2.6±0.22.8±0.2*2.6±0.22.6±0.2LDL-C86.3±38.894.4±34.380.5±25.082.9±22.1Total cholesterol154.6±44.9163.3±44.8143.9±29.2145.4±28.3GPx (U/g prot)17.5±9.829.1±30.719.7±20.341.0±27.7*⁎p<0.0

Human Papillomavirus in Brazilian women with and without cervical lesions

<p>Abstract</p> <p>Background</p> <p>Human Papillomavirus (HPV) high-risk (HR) types are the causal factor for cervical cancer and premalignant dysplasia. Data on frequency of HPV types provide a basis to design and evaluate HPV prevention programs. Taking into account the heterogeneity of HPV types across and within populations this study aims to access the HPV frequency in Brazilian women.</p> <p>Results</p> <p>We identified 24 different types of HPV, including a <it>Betapapillomavirus </it>and a likely new type, previously reported, from 132 women positive for the virus analysed by Hybrid Capture II assay. These women were infected by a single or multiple HPV types and 142 HPV strains were identified. HR types were found in 75% of women and HPV types 16, 18, 45, 58, and 66 had the highest frequency. Significant differences in frequency of HR HPV types were found for presence of cervical lesions, and for different HPV species and women age.</p> <p>Conclusions</p> <p>Compared with previous studies in Brazil, our data indicated differences in frequency and HPV type diversity, a significant association of other HR-types but HPV16 and 18 and cervical lesions, and a trend for distinct distribution of HPV types by age.</p

Analysis of drugs returned by inpatient services after unit dose distribution in a portuguese public hospital

Unit-dose has been considered the most effective dispensing system in hospital pharmacy, however not all drugs are administered, are then returned to the pharmacy. The analysis of non-administered drugs might provide important data regarding pharmacotherapeutic follow-up, but also regarding pharmacy management decisions. The present study aims at depicting the drugs returned to the pharmacy following their previous unit-dose dispensing. Methods: During a period of 45 days, the unused returned drugs of five different inpatient clinical services were analyzed regarding the state of conservation, justification for return, inpatient clinical service provenance, and dosage regimen. Of a total of 65280 unit-dose dispensed drugs, 25.2% were returned (n=16431) and 74.9% of SOS (i.e. medications prescribed as needed) drugs (n=6583) were unused. Excluding SOS drugs, more than a half of the returned drugs (52.4%, n=4967), were probably returned due to unintended omission of administration, after excluding patients that were not physically on the unit and patients whose treatments were modified. The large majority of returned drugs (98.6%, n=16201) were suitable for reintroduction in the medication circuit. In order to accomplish the basic principles of unit-dose dispensing genesis, the returned drugs must be kept to a minimum. Therefore, the suspension of dispensing SOS drugs by unit-dose should be considered. Additionally, the careful analysis of returned drugs should be promoted, in order to avoid, as much as possible, the omission of administration.info:eu-repo/semantics/publishedVersio