Necessary Optimality Conditions for Higher-Order Infinite Horizon Variational Problems on Time Scales

We obtain Euler-Lagrange and transversality optimality conditions for higher-order infinite horizon variational problems on a time scale. The new necessary optimality conditions improve the classical results both in the continuous and discrete settings: our results seem new and interesting even in the particular cases when the time scale is the set of real numbers or the set of integers.Comment: This is a preprint of a paper whose final and definite form will appear in Journal of Optimization Theory and Applications (JOTA). Paper submitted 17-Nov-2011; revised 24-March-2012 and 10-April-2012; accepted for publication 15-April-201

Generalized Assisted Inflation

We obtain a new class of exact cosmological solutions for multi-scalar fields with exponential potentials. We generalize the assisted inflation solutions previously obtained, and demonstrate how they are modified when there exist cross-couplings between the fields, such as occur in supergravity inspired cosmological models.Comment: 5 page

Nanoparticles In Treatment Of Thermal Injured Rats: Is It Safe?

The aim of this study was to assess whether thermal trauma induced oxidative stress altered the balance between oxidant and antioxidant systems in the blood of burn wound rats in the absence and presence of silver nanoparticles and S-nitrosoglutathione, GSNO. Free silver nanoparticles, free GSNO and silver nanoparticles + GSNO had no cytotoxic effects. Under anesthesia, the shaved dorsum of the rats was exposed to 90°C (burn group) water bath. Studied compounds were administered topically immediately and at 28 days after the burn injury, four times a day. Silver nanoparticles and silver nanoparticles + GSNO were no toxic in vitro and in vivo. There were no significant differences in the levels of urea, creatinine, aminotransferases and hematological parameters, in control-burn groups (free silver nanoparticles) and treated-burn groups (free GSNO or silver nanoparticles + GSNO). There were no differences in lipid peroxidation and in the levels of protein carbonyls and glutathione, used as oxidative stress markers. A little inflammatory cell response, papillary dermis vascularization, fibroblasts differentiated into contractile myofibroblasts and the presence of a large amount of extracellular matrix were evidenced in treated groups following skin injury. These results indicate that silver nanoparticles and GSNO may provide an effective action on wound healing.3041Tian, J., Wong, K.K.Y., Ho, C.M., Lok, C.N., Yu, W.Y., Che, C.M., Chiu, J.F., Tam, P.K.H., (2007) J. Chem. Med. Chem., 2, p. 129Teli, M.K., Mutalik, S., Rajanikant, G.K., (2010) Cur. Pharm. Design., 16, p. 1882Schaller, M., Laude, J., Bodewaldt, H., Hamm, G., Korting, H.C., (2004) Skin Pharmacol. Physiol., 17, p. 31Seabra, A.B., Da Silva, R., De Souza, G.F.P., De Oliveira, M.G., (2008) Artif. Organs, 32, p. 262Seabra, A.B., Pankotai, E., Fehér, M., Somlai, A., Kiss, L., Bíró, L., Szabó, C., Lacza, Z., (2007) Br. J. Dermatol., 156, p. 814Seabra, A.B., Martins, D., Simes, M.M.S.G., Da Silva, R., Brocchi, M., De Oliveira, M.G., (2010) Artif. Organs, 34, p. 204Durán, N., Marcato, P.D., Alves, O.L., De Souza, G.I.H., Esposito, E., (2005) J. Nanobiotechnol., 3, p. 1Durán, N., Marcato, P.D., De Souza, G.I.H., Alves, O.L., Esposito, E., (2007) J. Biomed. Nanotechnol., 3, p. 203Amadeu, T.P., Seabra, A.B., De Oliveira, M.G., Costa, A.M.A., (2007) J. Eur. Acad. Dermatol. Venereol., 21, p. 629Amadeu, T.P., Seabra, A.B., De Oliveira, M.G., Costa, A.M.A., (2008) J. Surg Res., 149, p. 84Correa, D.H.A., Melo, P.S., De Carvalho, C.A.A., De Azevedo, M.B.M., Durán, N., Haun, M., (2005) Eur. J. Pharmacol., 510, p. 17De Conti, R., Oliveira, D.A., Fernandes, A.M.A.P., Melo, P.S., Rodriguez, J.A., Haun, M., Castro, S.L., Durán, N., (1998) Vitro Mol. Toxicol, 11, p. 153Borefreund, E., Puerner, J.A., (1984) J. Tissue Cult. Methods, 9, p. 7Denizot, F., Lang, R., (1986) J. Immunol. Methods, 89, p. 271Michailidis, Y., Jamurta, A.Z., Nikolaidis, M.G., Fatouros, I.G., Koutedakis, Y., Papassotiriou, I., (2007) Med. Sci. Sport Exerc., 39, p. 1107Davis, T.A., Amare, M., Naik, S., Kovalchuk, A.L., Tadaki, D., (2007) Wound Repair Regen., 15, p. 57

Avaliação Da Assistência Oftalmológica Na Perspectiva Dos Usuários

The prevalence of need of, access to, and dissatisfaction with ophthalmic assistance was estimated among those who were assisted in such services in the last year; factors associated with dissatisfaction were identified. Complex probabilistic sample was used. A descriptive, bivariate, and multiple analysis with correction for design effect was conducted. Of 2.582 participants, 76% needed assistance and, of those, 82.5% possessed access to it. Among patients who received assistance in the last year, 13.1% were dissatisfied. Dissatisfaction was higher among older patients, those who went walking or cycling to the location of assistance, and those who described the following aspects as regular/bad/terrible: being received and treated with respect, the clarity with which the service provider explained things, and their autonomy to choose their provider of ophthalmic assistance. Most of them was in need of and possessed access to assistance. Dissatisfaction was low. Patient’s age, means of transport used to get to the local of the assistance, patient-professional relationship, and autonomy to choose are factors that interfere for the outcome of dissatisfaction. © 2016, Assocaicao Brasileira de Pos, Gradacao em Saude Coletiva. All rights reserved.19239040

Phytoestrogen agathisflavone ameliorates neuroinflammation-induced by LPS and IL-1β and protects neurons in cocultures of glia/neurons

Inflammation and oxidative stress are common aspects of most neurodegenerative diseases in the central nervous system. In this context, microglia and astrocytes are central to mediating the balance between neuroprotective and neurodestructive mechanisms. Flavonoids have potent anti-inflammatory and antioxidant properties. Here, we have examined the anti-inflammatory and neuroprotective potential of the flavonoid agathisflavone (FAB), which is derived from the Brazilian plant Poincianella pyramidalis, in in vitro models of neuroinflammation. Cocultures of neurons/glial cells were exposed to lipopolysaccharide (LPS, 1 µg/mL) or interleukin (IL)-1β (10 ng/mL) for 24 h and treated with FAB (0.1 and 1 µM, 24 h). FAB displayed a significant neuroprotective effect, as measured by nitric oxide (NO) production, Fluoro-Jade B (FJ-B) staining, and immunocytochemistry (ICC) for the neuronal marker β-tubulin and the cell death marker caspase-3, preserving neuronal soma and increasing neurite outgrowth. FAB significantly decreased the LPS-induced microglial proliferation, identified by ICC for Iba-1/bromodeoxyuridine (BrdU) and CD68 (microglia M1 profile marker). In contrast, FAB had no apparent effect on astrocytes, as determined by ICC for glial fibrillary acidic protein (GFAP). Furthermore, FAB protected against the cytodestructive and proinflammatory effects of IL-1β, a key cytokine that is released by activated microglia and astrocytes, and ICC showed that combined treatment of FAB with α and β estrogen receptor antagonists did not affect NF-κB expression. In addition, qPCR analysis demonstrated that FAB decreased the expression of proinflammatory molecules TNF-α, IL-1β, and connexins CCL5 and CCL2, as well as increased the expression of the regulatory molecule IL-10. Together, these findings indicate that FAB has a significant neuroprotective and anti-inflammatory effect in vitro, which may be considered as an adjuvant for the treatment of neurodegenerative diseases

On exact solutions for quintessential (inflationary) cosmological models with exponential potentials

We first study dark energy models with a minimally-coupled scalar field and exponential potentials, admitting exact solutions for the cosmological equations: actually, it turns out that for this class of potentials the Einstein field equations exhibit alternative Lagrangians, and are completely integrable and separable (i.e. it is possible to integrate the system analytically, at least by quadratures). We analyze such solutions, especially discussing when they are compatible with a late time quintessential expansion of the universe. As a further issue, we discuss how such quintessential scalar fields can be connected to the inflationary phase, building up, for this class of potentials, a quintessential inflationary scenario: actually, it turns out that the transition from inflation toward late-time exponential quintessential tail admits a kination period, which is an indispensable ingredient of this kind of theoretical models. All such considerations have also been done by including radiation into the model.Comment: Revtex4, 10 figure

Epigenetic silencing of TGFBI confers resistance to trastuzumab in human breast cancer

Altres ajuts: This work was supported in part by La Marató de TV3 (20131530, TPuig), financial support was from the University of Girona (MPCUdG2016/036), and the University of Girona and La Caixa Foundation awarded S. Palomeras with a predoctoral grant.Background: Acquired resistance to trastuzumab is a major clinical problem in the treatment of HER2-positive (HER2+) breast cancer patients. The selection of trastuzumab-resistant patients is a great challenge of precision oncology. The aim of this study was to identify novel epigenetic biomarkers associated to trastuzumab resistance in HER2+ BC patients. Methods: We performed a genome-wide DNA methylation (450K array) and a transcriptomic analysis (RNA-Seq) comparing trastuzumab-sensitive (SK) and trastuzumab-resistant (SKTR) HER2+ human breast cancer cell models. The methylation and expression levels of candidate genes were validated by bisulfite pyrosequencing and qRT-PCR, respectively. Functional assays were conducted in the SK and SKTR models by gene silencing and overexpression. Methylation analysis in 24 HER2+ human BC samples with complete response or non-response to trastuzumab-based treatment was conducted by bisulfite pyrosequencing. Results: Epigenomic and transcriptomic analysis revealed the consistent hypermethylation and downregulation of TGFBI, CXCL2, and SLC38A1 genes in association with trastuzumab resistance. The DNA methylation and expression levels of these genes were validated in both sensitive and resistant models analyzed. Of the genes, TGFBI presented the highest hypermethylation-associated silencing both at the transcriptional and protein level. Ectopic expression of TGFBI in the SKTR model suggest an increased sensitivity to trastuzumab treatment. In primary tumors, TGFBI hypermethylation was significantly associated with trastuzumab resistance in HER2+ breast cancer patients. Conclusions: Our results suggest for the first time an association between the epigenetic silencing of TGFBI by DNA methylation and trastuzumab resistance in HER2+ cell models. These results provide the basis for further clinical studies to validate the hypermethylation of TGFBI promoter as a biomarker of trastuzumab resistance in HER2+ breast cancer patients

Absence of the Fifth Force Problem in a Model with Spontaneously Broken Dilatation Symmetry

A scale invariant model containing dilaton $\phi$ and dust (as a model of matter) is studied where the shift symmetry $\phi\to\phi +const.$ is spontaneously broken at the classical level due to intrinsic features of the model. The dilaton to matter coupling "constant" $f$ appears to be dependent of the matter density. In normal conditions, i.e. when the matter energy density is many orders of magnitude larger than the dilaton contribution to the dark energy density, $f$ becomes less than the ratio of the "mass of the vacuum" in the volume occupied by the matter to the Planck mass. The model yields this kind of "Archimedes law" without any especial (intended for this) choice of the underlying action and without fine tuning of the parameters. The model not only explains why all attempts to discover a scalar force correction to Newtonian gravity were unsuccessful so far but also predicts that in the near future there is no chance to detect such corrections in the astronomical measurements as well as in the specially designed fifth force experiments on intermediate, short (like millimeter) and even ultrashort (a few nanometer) ranges. This prediction is alternative to predictions of other known models.Comment: 23 pages, some explanations expanded, misprints corrected, reference adde

Epidemiological situation of bovine brucellosis in the State of Rio Grande do Sul, Brazil

Realizou-se um estudo para caracterizar a situação epidemiológica da brucelose bovina. O Estado foi dividido em sete regiões. Em cada região foram amostradas aleatoriamente cerca de 300 propriedades, e dentro dessas foi escolhido de forma aleatória um número pré-estabelecido de animais, dos quais foi obtida uma amostra de sangue. No total foram amostrados 16.072 animais, provenientes de 1.957 propriedades. Em cada propriedade amostrada foi aplicado um questionário epidemiológico para verificar o tipo de exploração e as práticas zootécnicas e sanitárias que poderiam estar associadas ao risco de infecção pela doença. O protocolo de testes utilizado foi o da triagem com o teste do antígeno acidificado tamponado e o reteste dos positivos com o teste do 2-mercaptoetanol. O rebanho foi considerado positivo se pelo menos um animal foi reagente às duas provas sorológicas. Para o Estado, as prevalências de focos e de animais infectados foram, respectivamente, 2,1% [1,5-2,6%] e 1,0% [0,60-1,4%]. Para os circuitos, a prevalência de focos e a de animais foram, respectivamente: circuito 1, 3,1% [1,4-5,7%] e 0,95% [0,0-2,0%]; circuito 2, 7,7% [4,9-11,3%] e 1,0% [0,40-1,7%]; circuito 3, 5,7% [3,4-8,8%] e 2,1% [0,41-3,8%]; circuito 4, 0,66% [0,08-2,4%] e 0,66% [0,0-1,8%]; circuito 5, 0,66% [0,08-2,4%] e 0,05% [0,0-0,13%]; circuito 6, 0,0% [0,0-1,3%] e 0,0% [0,0-0,25%]; circuito 7, 5,4% [2,5-10,1%] e 2,9% [0,49-5,3%]. Os fatores de risco (odds ratio, OR) associados à condição de foco foram: exploração de corte (OR= 4,27 [1,82-10,01]) e histórico de aborto (OR=3,27,1,71-6,25]). ____________________________________________________________________________________________________________ ABSTRACTA study to characterize the epidemiological status of bovine brucellosis was carried out in the State of Rio Grande do Sul. The State was divided in seven regions. Three hundred herds were randomly sampled in each region and a pre-established number of animals were sampled in each of these herds. A total of 16,072 serum samples from 1,957 herds, were collected. In each herd, it was applied an epidemiological questionnaire focused on herd traits as well as husbandry and sanitary practices that could be associated with the risk of infection. The serum samples were screened for antibodies against Brucella spp. by the Rose-Bengal Test and all positive sera were re-tested by the 2-mercaptoethanol test. The herd was considered positive if at least one animal was positive on both tests. The prevalences of infected herds and animals in the State were, respectively 2.1% [1.5-2.6%] and 1.0% [0.60-1.4%]. In the regions, the prevalences of infected herds and animals were, respectively: region 1, 3.1% [1.4-5.7%] and 0.95% [0.0-2.0%]; region 2, 7.7% [4.9-11.3%] and 1.0% [0.40-1.7%]; region 3, 5.7% [3.4-8.8%] and 2.1% [0.41-3.8%]; region 4, 0.66% [0.08-2.4%] and 0.66% [0.0-1.8%]; region 5, 0.66% [0.08-2.4%] and 0.05% [0.0-0.13%]; region 6, 0.0% [0.0-1.3%] and 0.0% [0.0-0.25%]; and region 7, 5.4% [2.5-10.1%] and 2.9% [0.49-5.3%]. The risk factors (odds ratio, OR) associated with the presence of infection were: beef herd (OR= 4.27 [1.82-10.01]) and recent history of abortion (OR= 3.27-1.71-6.25])

Faraday rotation in graphene

We study magneto--optical properties of monolayer graphene by means of quantum field theory methods in the framework of the Dirac model. We reveal a good agreement between the Dirac model and a recent experiment on giant Faraday rotation in cyclotron resonance. We also predict other regimes when the effects are well pronounced. The general dependence of the Faraday rotation and absorption on various parameters of samples is revealed both for suspended and epitaxial graphene.Comment: 10 pp; v2: typos corrected and references added, v3, v4: small changes and more reference