Guest effect on nanopatterned spin-crossover thin films

Nanopatterned thin films of the metal-organic framework {Fe(bpac)[Pt(CN)4]} (bpac=bis(4-pyridyl)acetylene) are elaborated by the combination of a sequential assembly process and a lithographic method. Raman microspectroscopy is used to probe the temperature dependence of the spin state of the iron(II) ions in the films (40-90 nm in thickness), and reveals an incomplete but cooperative spin transition comparable to that of the bulk material. Adsorption/desorption of pyridine guest molecules is found to have a substantial influence on the spin-crossover properties of the thin layers. This interplay between host-guest and spin-crossover properties in thin films and nanopatterns demonstrates the potential ability of using this kind of material as a microsensor.     

Strong seasonality produces spatial asynchrony in the outbreak of infectious diseases

Models for infectious diseases usually assume a fixed demographic structure. Yet, a disease can spread over a region encountering different local demographic variations that may significantly alter local dynamics. Spatial heterogeneity in the resulting dynamics can lead to important differences in the design of surveillance and control strategies. We illustrate this by exploring the north–south gradient in the seasonal demography of raccoon rabies over the eastern USA. We find that the greater variance in the timing of spring births characteristic of southern populations can lead to the spatial synchronization of southern epidemics, while the narrow birth-pulse associated with northern populations can lead to an irregular patchwork of epidemics. These results indicate that surveillance in the southern states can be reduced relative to northern locations without loss of detection ability. This approach could yield significant savings in vaccination programmes. The importance of seasonality in many widely distributed diseases indicates that our findings will find applications beyond raccoon rabies.     

Maintaining yeast viability in continuous primary beer fermentation

Continuous fermentation is a long known and vastly studied process. The use of immobilized cell technology (ICT) is exploited in a significant number of studies owing to the associated high volumetric productivity, time savings and low capital demand. This work was aimed at solving one of the most relevant obstacles to implementing ICT on a large scale in beer fermentations, namely the control of biomass and the maintenance of cell viability in a gas‐lift bioreactor. For this purpose, foam fractionation by skimming was proposed as a tool for control of continuous biomass concentration. The consequences of foaming on lignocellulosic yeast carrier losses were assessed and discussed. A steady consumption of sugars from wort, as well as consistent ethanol production, were achieved. The viability of the suspended cells in the reactor was compared with that of the cell population in the foam using flow cytometry. Results suggest that foam might be used as a promising tool to skim non‐viable biomass out of the gas‐lift reactor, thus ensuring the maintenance of a cell culture with optimum viability. Copyright © 2014 The Institute of Brewing & Distilling     

Synthesis of nanocrystalline magnetite by mechanical alloying of iron and hematite

The synthesis of magnetite has been studied by mechanical alloying in an inert atmosphere of a stoichiometric mixture of micrometric particle size iron and hematite powders. The final products have been characterised by chemical analysis, SEM, TEM, XRD, Mössbauer spectroscopy as well as specific surface and magnetic measurements. The magnetite obtained in this way exhibits a high magnetic hardness. The formation of a wüstite layer on the magnetite core, because of the reaction between magnetite and iron contamination coming from the bowls and grinding balls, tends to decrease the coercive force of magnetite. The formation of this phase would be avoided by controlling the grinding time.     

The home treatment of deep venous thromboses with low-molecular-weight heparin

Low-molecular-weight heparins (LMWH) have shown to be at least as safe and efficient as non-fractionated heparin in the treatment of deep-vein thrombosis (DVT). Moreover, no serial laboratory controls are required. Therefore, LMWH allow the patients to be treated at home. From July 1995 to July 1996, 30 consecutive patients with DVT were enrolled in a prospective study and treated with nadroparin. Ambulatory treatment was feasible in 24 patients (9 patients did not require admission and 15 patients were discharged in less than 6 days). The main causes for admission were the inability to obtain a diagnosis, the severity of symptoms in the involved limb, and the presence of associated disease. None of the 24 patients to whom the possibility of home therapy was offered desired to remain at hospital. The ambulatory care of these patients increased the burden on primary care teams. There was no case of clinical recurrent thromboembolism nor a major hemorrhagic complication. Ambulatory treatment of DVT with nadroparin seems to be feasible, efficient and safe. Nevertheless, before using this therapeutic alternative a series of factors should be considered, which include the severity of clinical presentation, the embolic and hemorrhagic risks, and the presence of associated diseases.     

Screening for cancer of the cervix. Program of the Central Region of Portugal

Cervical cancer screening is clearly efficient, as can be proved by a simple comparison of the incidence and mortality rates for this neoplasia before and after the implementation of screening programmes in various countries and regions. The Screening Programme of the Central Region of Portugal is done by the G.P., who collects cytological smears in the Health Centres and sends them to the Cytopathology Laboratory of the Coimbra Cancer Institute (IPO). The IPO not only does the cytological test but also coordinates the programme and is responsible for quality control. To date, 83,173 women have been screened. Although the average participation rate is low (34.5%) some Health Centres have a very high rate, above 90%. The detection rate of pre-malignant lesions by cytology is 4.5%, which falls within the parameters provided by the WHO. The study of these cases confirms the high degree of sensitivity of cytology. For women who were tested a second time, the number of pre-malignant lesions revealed was not significant, so this procedure is more for quality control. When the programme began, only 0.4% of carcinomas were pre-invasive, compared to 42.1% now! Before the programme, only 18.6% of patients were able to be treated surgically, whilst now, 74.4% are able to benefit this way. The main problem continues to be the lack of definitions of the role of the Health Centres in the screening programme.     

Approximate rate formulation of non-elastic bifurcation problem for thin-walled structures

Simplified set of equations is derived for solution of a non-elastic bifurcation problem in thin-walled structures. The rate formulation is preferable, and based on the classical Hill's approach. It is shown that for a particular case of small strain the problem can be reduced to a more simple eigenvalue problem. As an example, the approach proposed has been applied to a circular stationary disk subjected to thermal expansion. The material of the disk is assumed to be elastic–perfectly plastic obeying the von Mises yield criterion with its associated flow rule. The influence of the width ratio on the bifurcation behavior has been discussed.     

Nutritional status in preschoolers attending a public day-care center in Valencia, Venezuela

With the purpose of evaluating nutritional status in a group of preschoolers attending a public day care center in Valencia, Venezuela (2002), a research was made for social stratus, anthropometric variables; weight, height and arm circumference, hemoglobin, seric retinol, presence of parasitosis and food consumption, as well as the mother's educational level. The program SPSS 11.0 and the t Student, ANOVA Post Hoc from Bonferroni and Fisher (p < 0.05) were used. A predominance of the female sex was presented (52%). According to the social stratus, 23.3% was located in the middleclass, and 76.8% on some level of poverty. 60% of the middleclass mothers had finished their high school education, while only 9.8% of the mothers in poverty had reached that level. According to the Z values (H/A, W/H and AC/H), high percentages under -1.00 were observed (27.3%, 25.6% and 24.5%, respectively). The W/H and AC/H of children of mothers studying in a university presented discrepancies when compared with children of mothers with a primary educational level. A 25.9% of anemia was presented, and there were differences between anemic and non-anemic groups for H/A and AC/H. Protozoaries were observed in 61.0%, helmintos in 16.9% and both in 22.1%. There was a 2.6 times higher risk of presenting nutritional deficiency for AC/H in the group found with parasites. An adequate consumption of energy and iron was found, with an excessive consumption of proteins and vitamin A. It is concluded that there exists a nutritional risk evaluated through hematologic parameters, the presence of parasitosis and social stratus.     

Inositol hexaphosphate: a potential chelating agent for uranium

Chelation therapy is an optimal method to reduce the radionuclide-related risks. In the case of uranium incorporation, the treatment of choice is so far i.v infusion of a 1.4% sodium bicarbonate solution, but the efficacy has been proved to be not very high. In this study, we examine the efficacy of some substances: bicarbonate, citrate, diethylenetriamine pentaacetic acid (DTPA), ethidronate (EHBP) and inositol hexaphosphate (phytic acid) to chelate uranium using a test developed by Braun et al. Different concentrations of phytic acid, an abundant component of plant seeds that is widely distributed in animal cells and tissues in substantial levels, were tested and compared to the same concentrations of sodium citrate, bicarbonate, EHBP and DTPA. The results showed a strong affinity of inositol hexaphosphate for uranium, suggesting that it could be an effective chelating agent for uranium in vivo.