1,900 research outputs found
Barrierless procedure for substitutionally doping graphene sheets with boron atoms: ab initio calculations
Using ab initio methods, we propose a simple and effective way to
substitutionally dope graphene sheets with Boron. The method consists of
selectively exposing each side of the graphene sheet to different elements. We
first expose one side of the membrane to Boron, while the other side is exposed
to Nitrogen. Proceeding this way, the B atoms will be spontaneously
incorporated into the graphene membrane, without any activation barrier. In a
second step, the system should be exposed to a H-rich environment, that will
remove the CN radical from the layer and form HCN, leading to a perfect
substitutional doping.Comment: Accepted Physical Review
Impact of the economic crisis on human resources for health policies in Southern EU countries
Background
The economic and financial crisis which started in the European Union in 2008 affected some countries more than others. Cyprus, Greece, and Portugal had to receive emergency financial aid from the so-called Troika (International Monetary Fund, Central European Bank, European Commission) and consequently were imposed severe austerity measures. All sectors were affected, including health. This paper focuses on the effects of the crisis on the health workforce, which represents the largest share of expenditures in the sector, and on policy responses from these three governments to measures ‘imposed' by the Troika.
Methods
A systematic search of peer-reviewed and grey literature, and key sources such as government websites was performed. Interviews with key informants were also conducted. Country data and information served to assess policy responses and their effects on the availability, accessibility, acceptability and quality of human resources for health.
Results
Countries responded to the crisis and to the conditions set by lenders by reducing or freezing salaries and benefits, by cutting on recruitment and even dismissing personnel, by increasing workloads, and by introducing other cost containment measures. The three countries do not seem to have used the crisis as an opportunity to make efficiency gains and thereby improve the performance of their health workforce.
Conclusions
This paper is included in the Workshop because it discusses policy responses to a major economic shock by governments facing external constraints, which at the same time limited their capacity for action and provided opportunities for reforminfo:eu-repo/semantics/acceptedVersio
Deindustrialization in the light of classical location theory
In this paper, we used a framework due VON THUNEN (1966) and Friedrich LIST (1841) where manufacturing development is regarded as a process of “refining” primary raw materials in order to yield “lighter”, easier to carry products. If the artificial regulations which formerly kept industrial plants confined to core urban areas are abolished, then factories shift to rural areas in order to be close to the sources of farming raw materials, provided that the industrial transformation is sufficiently weight losing. However, the new productive sites for manufacturing will remain at a bounded distance from the Town, since they must bear the transport costs of shipping the output to the central meeting point where it must be transacted. Areas which are beyond this distance threshold are occupied by a traditional cottage economy, where goods are not carried to the Town but are rather produced for the household self-consumption. This framework also explains the observed fact that, within manufacturing, resource based branches are more centrally located in relation to core urban areas than other sectors.info:eu-repo/semantics/publishedVersio
Molecular characterization of larval anisakid nematodes from marine fishes of Madeira by a PCR-based approach, with evidence for a new species
One-hundred and fifteen anisakid larvae from 3 different fish hosts, Aphanopus carbo, Scomber japonicus, and Trachurus picturatus, caught in Madeiran waters, were identified by PCR-RFLP. Three distinct species were identified in A. carbo, namely Anisakis simplex sensu stricto, Anisakis pegreffii, and Anisakis ziphidarum; 5 in S. japonicus, i.e., A. simplex s.s., A. pegreffii, Anisakis physeteris, Anisakis typica, and A. ziphidarum; and 3 in T. picturatus, i.e., A. simplex s.s., A. pegreffii, and A. typica. Anisakis simplex s.s. was the most frequent species in both A. carbo and S. japonicus (54% and 23.5%, respectively). Anisakis pegreffii and A. physeteris occurred with a frequency of 20.6% in S. japonicus, whereas in T. picturatus the most frequent species was A. typica (41.9%), followed by A. simplex s.s. (32.3%). Furthermore, A. carbo and S. japonicus were infected by an apparently undescribed taxon, provisionally named Anisakis sp. A. Based on estimations of the genetic distance, this new taxon seems to be more similar to A. ziphidarum (0.0335) than to other species of the genus
Procedimento de operação, manutenção e verificação de centrífuga JOUAN refrigerada.
bitstream/CENARGEN/29585/1/ct064.pd
Processing of conductive filled polymers using microinjection
Polystyrene granules were coated by sputtering
with an innovative film of stainless steel
obtaining this way a composite. To compare
results it was necessary to prepare two different
composites, mixing polymer granules with steel
fibers mechanically in a drum.
Microinjection molding is a processing
technique that allowed obtaining a
representative sample of each composite.
Scanning electron microscope (SEM) allowed
the characterization of the coating thickness
while the dispersion and distribution of metal
particles were analyzed by optical microscopy
in polarized light. Results showed a uniform
thickness of the coating and good dispersion of
the reinforcements in the matrix. Electrical and
mechanical properties of the composites were
characterized by measuring the electrical
resistivity and flexural tests. Considerable
values of conductivity were exhibited in
composites with carbon nanotubes and a slight
increase in the modulus of the polymers due to
reinforcement incorporation was noticed
Study of the adhesion on overmoulded parts with thermoplastic/LSR combination
Multi-material parts with PBT/LSR combination were produced in two separate steps,
one for the injection of PBT parts, and a second for the LSR overmoulding. The aim of this work is
to study the influence of process-parameters such as mold temperature, curing time, temperature of
the PBT insert before performing the overmoulding with LSR, on the adhesion with LSR’s. The
effect on the adhesion of the amount of glass fiber content on the PBT was also studied. The
adhesion between the materials was measured using a peel-test 90º.
The results of the peel-test indicated that the adhesion is influenced by the parameters described.
The adhesion between the two materials increase significantly with the increase of the processparameters
Histopathological and immunohistochemical differentiation of epithelial alterations in vocal nodule comparing to polyps and to laryngeal edema
AIM: To evaluate by histological and immunohistochemical methods the epithelial lesions in vocal nodule and correlate with polyp, laryngeal edema and vocal folds without macroscopic lesions. STUDY DESIGN: Chart review. MATERIAL AND METHOD: In a retrospective analysis of medical records, twenty-six patients, who underwent microsurgical excision of laryngeal inflammatory lesions (nodules, polyps and laryngeal edema), were identified. Vocal folds without macroscopic lesions were obtained from autopsy. To evaluate epithelial lesions, specimens were stained with H&E, PAS, and with antibodies against laminin and collagen type IV. These specimens were analyzed by light microscopy. RESULTS: Lesions diagnosed as nodules showed more collagen type IV and laminin deposition when compared to polyps (p=0,034 and p=0,036, respectively) and to vocal folds without macroscopic lesions (p=0,019 and p=0,021, respectively). Nodules showed basement membranes thicker than polyps on PAS stain (p=0,102). Laryngeal edema could not be differentiated from nodules, polyps or vocal folds without macroscopic lesions by PAS, laminin or collagen type IV stain (p>0,10). CONCLUSION: By histological and immunohistochemical techniques to evaluate epithelium of laryngeal inflammatory lesions we conclude that vocal fold nodule differentiate from polyps on the three techniques used to stain basement membrane (PAS, laminin, collagen IV) and from vocal folds without macroscopic lesions on two techniques used (laminin, collagen IV). Laryngeal edema cannot be differentiated from the others laryngeal lesions, neither from vocal folds without macroscopic lesions, when the techniques before described are used.OBJETIVO: Avaliar, por meio de técnicas histológicas e imunoistoquímicas, o epitélio nos nódulos vocais em relação aos pólipos, ao edema de laringe e às pregas vocais sem lesões macroscópicas. FORMA DE ESTUDO: Clínico retrospectivo. MATERIAL E MÉTODO: Por meio de levantamento de prontuário, foram identificados vinte e seis pacientes com lesões laríngeas inflamatórias (nódulos, pólipos e edema de laringe), que haviam sido submetidos à cirurgia. Pregas vocais sem alterações macroscópicas foram obtidas a partir de autópsia de cadáveres. Para análise do epitélio, foram realizadas colorações pela técnica da hematoxilina-eosina e do ácido periódico de Schiff e técnicas de imunoistoquímica com anticorpos dirigidos contra laminina e colágeno IV. A leitura das lâminas foi realizada por meio de microscopia óptica. RESULTADOS: Houve maior imunoexpressão de laminina e colágeno IV nos nódulos quando comparados aos pólipos (p=0,034 e p=0, 036, respectivamente), assim como quando comparados às pregas vocais sem lesões macroscópicas (p=0,019 e p=0, 021, respectivamente). Nódulos tendem a apresentar maior espessura da membrana basal, quando utilizamos coloração pela técnica do PAS, em relação aos pólipos (p=0,102). O edema de laringe não se diferenciou das demais nas técnicas utilizadas (p> 0,10). CONCLUSÕES: O Nódulo Vocal diferencia-se dos pólipos, nas três técnicas utilizadas para detecção da membrana basal (PAS, laminina, colágeno IV), e das pregas vocais sem lesões macroscópicas em duas das técnicas utilizadas (laminina e colágeno IV). Edema de laringe não se diferencia das demais lesões, nem de pregas vocais sem lesões macroscópicas, quando utilizadas as técnicas anteriormente descritas, para estudo da membrana basal.Universidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Departamento de Otorrinolaringologia e Distúrbios da Comunicação HumanaUniversidade de São Paulo Faculdade de OdontologiaUNIFESP, EPM, Depto. de Otorrinolaringologia e Distúrbios da Comunicação HumanaSciEL
Ejection force of tubular injection moldings. Part II : a prediction model
The integrated knowledge of the injection molding process
and the material changes induced by processing is
essential to guarantee the quality of technical parts. In
the case of parts with deep cavities, quite often the
ejection phase of the molding cycle is critical. Thus, in
the mold design stage, the aspects associated with the
ejection system will require special consideration. In
particular, the prediction of the ejection force will contribute
to optimizing the mold design and to guarantee
the integrity of the moldings. In this work, a simulation
algorithm based on a thermomechanical model is described
and their predictions are compared with experimental
data obtained from a fully-instrumented mold
(pressure, temperature, and force). Three common thermoplastics
polymers were used for the tubular moldings:
a semicrystalline polypropylene and two amorphous
thermoplastics: polystyrene and polycarbonate.
The thermomechanical model is based on the assumption
of the polymer behavior changing from purely viscous
to purely elastic below a transition point. This point
corresponds to solidification determined by temperature
in the case of amorphous materials and by critical crystallinity
for semicrystalline polymers. The model results
for the ejection force closely agree with the experimental
data for the three materials used
North American entomophagy
Eating insects is not a common Northern American practice today. However, in the past a variety of insect species was consumed in Northern America (north of Mexico including Greenland). The aim of this literature review is to provide an historical overview of North American entomophagy based upon both peer and non-peer reviewed sources on this topic. Regional differences in insect consumption and reasons for being underreported are discussed. We show that North American natives, and in certain cases colonists, collected and consumed a large variety of edible insects. These are categorized per order and where available, information on how these species were collected and processed is provided. Lastly, we mention reasons for the renewed interest in edible insects in North America, and make suggestions for future studies
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