Generalized Differential Geometry

Generalized Functions play a central role in the understanding of differential equations containing singularities and nonlinearities. Introducing infinitesimals and infinities to deal with these obstructions leads to controversies concerning the existence, rigor and the amount of non-standard analysis needed to understand these theories. Milieus constructed over the generalized reals sidestep them all. A Riemannian manifold M embeds discretely into a generalized manifold $M^*$ on which singularities vanish and products of nonlinearities make sense. Linking this to an already existing global theory provides an algebra embedding $\kappa :\hat{{\cal{G}}}(M)\longrightarrow {\cal{C}}^{\infty}(M^*,\widetilde{\mathbb{R}}_f)$. Generalized Space-Time is constructed and its possible effects on Classical Space-Time are examined

New synthetic raloxifen-like di(hetero)arylamines induce apoptosis and inhibit the estrogen receptor in breast cancer cells

Breast cancer is the most common form of cancer in women in the western world, and in spite of some decline in death rates in recent years it is still the second most common cause of death from cancer, in women (1). For more than three decades, the estrogen receptor (ER) has been the most important biomarker of breast cancer, largely due to the substantial benefit that endocrine therapy provides in the treatment of ER positive tumors, in women of all ages (2). Endocrine therapies currently available include selective estrogen receptor modulators (SERMs), like tamoxifen and raloxifene (3). Raloxifene acts as an estrogen antagonist in the breast by competitive binding to the ER, inhibiting estrogen-induced breast tissue proliferation and preventing the growth of mammary tumors. In addition, it shows no increase in incidence of endometrial cancer, which is an advantage compared to tamoxifen (4). The successes of these endocrine therapies, however, are often limited. So, it is important to continue searching for new strategies and/or drugs that overcome resistance problems and that can be potent enough with fewer adverse effects. In this work, we studied the effect of two new synthetic di(hetero)arylamines, named MJQ2 and MJQ3 (which have in common with raloxifene a benzothiophene ring), in cell proliferation and apoptosis of two different cell lines from breast cancer: MCF-7 (ER positive) and MDA-MB-231 (ER negative). Our results showed that both diarylamines induce apoptosis without significant necrosis (evaluated by Hoechst-PI staining), at the IC50 concentration that inhibits cell proliferation (evaluated by the SRB assay). The results obtained with TMRM, a marker of mitochondrial membrane potential, suggest that mitochondrial disruption can be involved in this apoptotic process. These effects are more pronounced in the MCF-7 cell line (ER positive), suggesting that the presence of the ER might be important in the response to these compounds. Confirmation of their interaction with the ER was obtained in the E-Screen assay, where a clear antagonism of the proliferative effects of the hormone 17β-estradiol was observed with both compounds, at non-toxic concentrations. The overall results suggest that these new synthetic “raloxifene-like” drugs might have potential to be further developed as alternative hormonal or adjuvant therapies for breast cancer.Fundação para a Ciência e a Tecnologia (FCT) research project PTDC/QUI/68382/2006 (FCOMP-01-0124-FEDER 007441)

Expressão da fertilidade de gemas da Superior Seedless no Município de Petrolina (PE).

Objetivou-se com o presente trabalho avaliar a expressão da fertilidade de gemas da ?Superior Seedless? no município de Petrolina (PE), através da relação fertilidade de gemas real/potencial. A fertilidade potencial foi avaliada antes da poda pela análise microscópica das gemas e a fertilidade real pela relação: número de cacho e mitido por gema/número total de gema brotada por planta. Verificou-se que a taxa média de expressão da fertilidade real/potencial, para as condições locais de estudo foi de 59,52%

Domain size effects in Barkhausen noise

The possible existence of self-organized criticality in Barkhausen noise is investigated theoretically through a single interface model, and experimentally from measurements in amorphous magnetostrictive ribbon Metglas 2605TCA under stress. Contrary to previous interpretations in the literature, both simulation and experiment indicate that the presence of a cutoff in the avalanche size distribution may be attributed to finite size effects.Comment: 5 pages, 3 figures, submitted so Physical Review

Palladium-catalyzed borylation and Suzuki coupling (BSC) to obtain beta-substituted dehydroamino acid derivatives

Several benzo[b]thienyldehydroamino acids were prepared by one pot palladium-catalyzed borylation and Suzuki coupling (BSC) from bromobenzo[b]thiophenes containing EDG (OMe or Me), as the component to be borylated with pinacolborane, and pure stereoisomers of beta-bromodehydroamino acid derivatives. To our knowledge it is the first time that the BSC reaction involves a non aromatic system.Fundação para a Ciência e Tecnologia - POCTI/1999/QUI/32689, SFRH/BD/4709/2001

Características produtivas de cultivares de cebola sob dois métodos de manejo irrigação.

Suplemento. Edição dos Trabalhos do 50. Congresso Brasileiro de Olericultura, Guarapari, jul. 2010