740 research outputs found

    Duality in Nondifferentiable Vector Programming

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    AbstractIn this paper we study the saddle point optimality conditions and Lagrange duality in multiobjective optimization for generalized subconvex-like functions. We obtain results which will allow us to characterize the solutions for multiobjective programming problems from the saddle point conditions and allow us to relate them to the dual problem solutions which will be adequately defined. We also define a new dual problem for the multiobjective programming problem with the special property of being a scalar programming problem

    Generalized Convexity in Multiobjective Programming

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    AbstractFor the scalar programming problem, some characterizations for optimal solutions are known. In these characterizations convexity properties play a very important role. In this work, we study characterizations for multiobjective programming problem solutions when functions belonging to the problem are differentiable. These characterizations need some conditions of convexity. In differentiable scalar programming problems the concept of invexity is very important. We prove that it is also necessary for the multiobjective programming problem and give some characterizations of multiobjective programming problem solutions under weaker conditions. We define analogous concepts to those of stationary points and to the conditions of Kuhn–Tucker and Fritz–John for the multiobjective programming problem

    Preinvex functions and weak efficient solutions for some vectorial optimization problem in Banach spaces

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    AbstractIn this work, we introduce the notion of preinvex function for functions between Banach spaces. By using these functions, we obtain necessary and sufficient conditions of optimality for vectorial problems with restrictions of inequalities. Moreover, we will show that this class of problems has the property that each local optimal solution is in fact global

    Efficient inhibition of iron superoxide dismutase and of Trypanosoma cruzi growth by benzo[g]phthalazine derivatives functionalized with one or two imidazole rings

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    The synthesis and trypanosomatic behavior of a new series of 1,4-bis(alkylamino)benzo[g]phthalazines 1−4 containing the biologically significant imidazole ring are reported. In vitro antiparasitic activity against Trypanosoma cruzi epimastigotes is remarkable, especially for compound 2, whereas toxicity against Vero cells is very low. Conversion of epimastigotes to metacyclic forms in the presence of the tested compounds causes significant decreases in the amastigote and trypomastigote numbers. Fe-SOD inhibition is noteworthy, whereas effect on human Cu/Zn-SOD is negligible.The authors thank the Spanish CICYT for the financial support

    Basal VEGF-A and ACE Plasma Levels of Metastatic Colorectal-Cancer Patients Have Prognostic Value for First-Line Treatment with Chemotherapy Plus Bevacizumab

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    The identification of factors that respond to anti-angiogenic therapy would represent a significant advance in the therapeutic management of metastatic-colorectal-cancer (mCRC) patients. We previously reported the relevance of VEGF-A and some components of the renin–angiotensin-aldosterone system (RAAS) in the response to anti-angiogenic therapy in cancer patients. Therefore, this prospective study aims to evaluate the prognostic value of basal plasma levels of VEGF-A and angiotensin-converting enzyme (ACE) in 73 mCRC patients who were to receive bevacizumab-based therapies as a first-line treatment. We found that high basal VEGF-A plasma levels were significantly associated with worse overall survival (OS) and progression-free survival (FPS). On the other hand, low ACE levels were significantly associated with poor OS. Importantly, a simple scoring system combining the basal plasma levels of VEGF-A and ACE efficiently stratified mCRC patients, according to OS, into high-risk or low-risk groups, prior to their treatment with bevacizumab. In conclusion, our study supports that VEGF-A and ACE may be potential biomarkers for selecting those mCRC patients who will most benefit from receiving chemotherapy plus bevacizumab treatment in first-line therapy. Additionally, our data reinforce the notion of a close association between the RAAS and the anti-angiogenic response in cancer

    1,4-Bis(alkylamino)benzo[g]phthalazines able to form dinuclear complexes of Cu(II) which as free ligands behave as SOD inhibitors and show efficient in vitro activity against Trypanosoma cruzi

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    The synthesis of a new series of 1,4-bis(alkylamino)benzo[g]phthalazines 1–3 is reported, and their ability to form dinuclear complexes with Cu(II) assayed. The geometry of the complexes is dependent on the nature of the electron-donor sites at the sidechains. Compounds 1 and 2, that contain sp3 or sp2 nitrogens at the end of the alkylamino groups, originate monopodal dinuclear complexes which seem to include endogenous OH bridges, and the sidechains seem to actively participate in complexation. However, the substitution of nitrogen by oxygen in 3 leads to a tripodal dinuclear complex in which the sidechains are not involved. The in vitro antiparasitic activity on Trypanosoma cruzi epimastigotes and amastigotes and the SOD activity inhibition have been evaluated for compounds 1–3, and, as expected, 1 and 2 show in all cases relevant results, whereas 3 is always the less active among the three substrates tested.The authors thank the Spanish Comision Interministerial de Ciencia y Tecnologia for the economical support given to this work (SAF99-0066)

    Values and Intercultural Experiences Through Picture Books

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    The authors searched for picture books that are useful for intercultural education and for discovering students’ perceptions about the values and intercultural experiences conveyed through the books. To do so, the authors selected two books by following established criteria and analyzed students’ responses through semistructured interviews. The data were obtained after reading the books aloud to 30 fifth-grade students in a school located in the south of Spain and reflecting on the books’ contents. As a main conclusion, the authors found that students’ answers revealed the presence of some positive values, such as helpfulness, friendship, and empathy, through questions about the experiences of characters in the books. Thus, prejudices were dismantled and positive intercultural experiences in school were fostered

    Circulating Cell-Free DNA-Based Liquid Biopsy Markers for the Non-Invasive Prognosis and Monitoring of Metastatic Pancreatic Cancer

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    Liquid biopsy may assist in the management of cancer patients, which can be particularly applicable in pancreatic ductal adenocarcinoma (PDAC). In this study, we investigated the utility of circulating cell-free DNA (cfDNA)-based markers as prognostic tools in metastatic PDAC. Plasma was obtained from 61 metastatic PDAC patients, and cfDNA levels and fragmentation were determined. BEAMing technique was used for quantitative determination of RAS mutation allele fraction (MAF) in cfDNA. We found that the prognosis was more accurately predicted by RAS mutation detection in plasma than in tissue. RAS mutation status in plasma was a strong independent prognostic factor for both overall survival (OS) and progression-free survival (PFS). Moreover, RAS MAF in cfDNA was also an independent risk factor for poor OS, and was strongly associated with primary tumours in the body/tail of the pancreas and liver metastases. Higher cfDNA levels and fragmentation were also associated with poorer OS and shorter PFS, body/tail tumors, and hepatic metastases, whereas cfDNA fragmentation positively correlated with RAS MAF. Remarkably, the combination of CA19-9 with MAF, cfDNA levels and fragmentation improved the prognostic stratification of patients. Furthermore, dynamics of RAS MAF better correlated with patients’ outcome than standard CA19-9 marker. In conclusion, our study supports the use of cfDNA-based liquid biopsy markers as clinical tools for the non-invasive prognosis and monitoring of metastatic PDAC patients

    The Combination of Neutrophil–Lymphocyte Ratio and Platelet–Lymphocyte Ratio with Liquid Biopsy Biomarkers Improves Prognosis Prediction in Metastatic Pancreatic Cancer

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    Pancreatic ductal adenocarcinoma (PDAC) is an aggressive cancer with a highly inflammatory microenvironment and liquid biopsy has emerged as a promising tool for the noninvasive analysis of this tumor. In this study, plasma was obtained from 58 metastatic PDAC patients, and neutrophil–lymphocyte ratio (NLR), platelet–lymphocyte ratio (PLR), circulating cell-free DNA (cfDNA) concentration, and circulating RAS mutation were determined. We found that NLR was significantly associated with both overall survival (OS) and progression-free survival. Remarkably, NLR was an independent risk factor for poor OS. Moreover, NLR and PLR positively correlated, and combination of both inflammatory markers significantly improved the prognostic stratification of metastatic PDAC patients. NLR also showed a positive correlation with cfDNA levels and RAS mutant allelic fraction (MAF). Besides, we found that neutrophil activation contributed to cfDNA content in the plasma of metastatic PDAC patients. Finally, a multi-parameter prognosis model was designed by combining NLR, PLR, cfDNA levels, RAS mutation, RAS MAF, and CA19-9, which performs as a promising tool to predict the prognosis of metastatic PDAC patients. In conclusion, our study supports the idea that the use of systemic inflammatory markers along with circulating tumor-specific markers may constitute a valuable tool for the clinical management of metastatic PDAC patients

    Continuity for s-convex fuzzy processes

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    In a previous paper we introduced the concept of s-convex fuzzy mapping and established some properties. In this work we study the continuity for s-convex fuzzy processes
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