115 resultados para Mixed-integer linear programing


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A study was conducted to verify whether the theory on the evolution of corporate environmental management (CEM) is applicable to organizations located in Brazil. Some of the most important proposals pertaining to the evolution of CEM were evaluated in a systematic fashion and integrated into a typical theoretical framework containing three evolutionary stages: reactive, preventive and proactive. The validity of this framework was tested by surveying 94 companies located in Brazil with ISO 14001 certification. Results indicated that the evolution of CEM tends to occur in a manner that is counter to what has generally been described in the literature. Two evolutionary stages were identified: 1) synergy for eco-efficiency and 2) environmental legislation view, which combine variables that were initially categorized into different theoretical CEM stages. These data, obtained from a direct study of Brazilian companies, suggest that the evolution of environmental management in organizations tends to occur in a non-linear fashion, requiring a re-analysis of traditional perceptions of CEM development, as suggested by Kolk and Mauser (2002). (C) 2010 Elsevier Ltd. All rights reserved.

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Surface pressure (pi)-molecular area (A) curves were used to characterize the packing of pseudo-ternary mixed Langmuir monolayers of egg phosphatidylcholine (EPC), 1,2-dioleoyl-3-trimethylammonium propane (DOTAP) and L-alpha-dioleoyl phosphatidylethanolamine (DOPE). This pseudo-ternary mixture EPC/DOPE/DOTAP has been successfully employed in liposome formulations designed for DNA non-viral vectors. Pseudo-binary mixtures were also studied as a control. Miscibility behavior was inferred from pi-A curves applying the additivity rule by calculating the excess free energy of mixture (Delta G(Exc)). The interaction between the lipids was also deduced from the surface compressional modulus (C(s)(-1)). The deviation from ideality shows dependence on the lipid polar head type and monolayer composition. For lower DOPE concentrations, the forces are predominantly attractive. However, if the monolayer is DOPE rich, the DOTAP presence disturbs the PE-PE intermolecular interaction and the net interaction is then repulsive. The ternary monolayer EPC/DOPE/DOTAP presented itself in two configurations, modulated by the DOPE content, in a similar behavior to the DOPE/DOTAP monolayers. These results contribute to the understanding of the lipid interactions and packing in self-assembled systems associated with the in vitro and in vivo stability of liposomes. (C) 2010 Elsevier B.V. All rights reserved.

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One-pot hydrochalcogenation of 1-phenylthioacetylenes using organylselenolate and organyltellurolate anions generated by the insertions of selenium and tellurium in n-organyl lithium produced (Z)-1,2-bis(organylchalcogene)-1-alkenes. The chemical reactivity of these mixed 1,2-bis(organylchalcogene)-1-alkenes was studied by Te/Li and Se/Li stereoretentive exchanges carried out with n-butyl lithium, furnishing the new intermediate species (Z)-beta-organylthio vinyllithium anions, which were trapped with aldehydes, to give the (Z)-3-hydroxy vinyl thioethers with total control of the regio- and stereochemistry. (c) 2010 Elsevier Ltd. All rights reserved.

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Modeling volatile organic compounds (voc`s) adsorption onto cup-stacked carbon nanotubes (cscnt) using the linear driving force model. Volatile organic compounds (VOC`s) are an important category of air pollutants and adsorption has been employed in the treatment (or simply concentration) of these compounds. The current study used an ordinary analytical methodology to evaluate the properties of a cup-stacked nanotube (CSCNT), a stacking morphology of truncated conical graphene, with large amounts of open edges on the outer surface and empty central channels. This work used a Carbotrap bearing a cup-stacked structure (composite); for comparison, Carbotrap was used as reference (without the nanotube). The retention and saturation capacities of both adsorbents to each concentration used (1, 5, 20 and 35 ppm of toluene and phenol) were evaluated. The composite performance was greater than Carbotrap; the saturation capacities for the composite was 67% higher than Carbotrap (average values). The Langmuir isotherm model was used to fit equilibrium data for both adsorbents, and a linear driving force model (LDF) was used to quantify intraparticle adsorption kinetics. LDF was suitable to describe the curves.

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The goal of this paper is to study the global existence of small data solutions to the Cauchy problem for the nonlinear wave equation u(tt) - a(t)(2) Delta u = u(t)(2) - a(t)(2)vertical bar del u vertical bar(2). In particular we are interested in statements for the 1D case. We will explain how the interplay between the increasing and oscillating behavior of the coefficient will influence global existence of small data solutions. Copyright c 2011 John Wiley & Sons, Ltd.

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New differential linear coherent scattering coefficient, mu(CS), data for four biological tissue types (fat pork, tendon chicken, adipose and fibroglandular human breast tissues) covering a large momentum transfer interval (0.07 <= q <= 70.5 nm(-1)), resulted from combining WAXS and SAXS data, are presented in order to emphasize the need to update the default data-base by including the molecular interference and the large-scale arrangements effect. The results showed that the differential linear coherent scattering coefficient demonstrates influence of the large-scale arrangement, mainly due to collagen fibrils for tendon chicken and fibroglandular breast samples, and triacylglycerides for fat pork and adipose breast samples at low momentum transfer region. While, at high momentum transfer, the mu(CS) reflects effects of molecular interference related to water for tendon chicken and fibroglandular samples and, fatty acids for fat pork and adipose samples. (C) 2009 Elsevier B.V. All rights reserved.

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Mixed connective tissue disease (MCTD) is a rare disease that includes clinical and laboratorial manifestations of systemic lupus erythematosus, scleroderma and polymyositis that is associated with high titers of anti-U1RNP antibodies. In general, muscle involvement is subclinical, usually appearing as an increase in muscle enzyme levels that tends to be a characteristic of the initial phases of the disease. Severe clinical muscle weakness is not observed in this disease. The objective of this study is to report a rare case of a patient who presented a severe onset of myositis characterized by dysphagia, an increase in myopathy and a weakening of the cervical musculature. While there was no response to the administration of an initial dose of corticosteroids, improvement was observed after increasing the dose of corticosteroids, in addition to the initiation of pulse therapy with methylprednisolone accompanied by methotrexate treatment. The authors emphasize that there is only one previously reported case regarding a child with MCTD and severe clinical myopathy on electromyography and muscle biopsy, and they report in this article one adult female patient who presented severe myositis and was refractive to corticotherapy. Lupus (2010) 19, 1659-1661.

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Background: Urban air pollutants are associated with cardiovascular events. Traffic controllers are at high risk for pollution exposure during outdoor work shifts. Objective: The purpose of this study was to evaluate the relationship between air pollution and systemic blood pressure in traffic controllers during their work shifts. Methods: This cross-sectional study enrolled 19 male traffic controllers from Santo Andre city (Sao Paulo, Brazil) who were 30-60 years old and exposed to ambient air during outdoor work shifts. Systolic and diastolic blood pressure readings were measured every 15 min by an Ambulatory Arterial Blood Pressure Monitoring device. Hourly measurements (lags of 0-5 h) and the moving averages (2-5 h) of particulate matter (PM(10)), ozone (O(3)) ambient concentrations and the acquired daily minimum temperature and humidity means from the Sao Paulo State Environmental Agency were correlated with both systolic and diastolic blood pressures. Statistical methods included descriptive analysis and linear mixed effect models adjusted for temperature, humidity, work periods and time of day. Results: Interquartile increases of PM(10) (33 mu g/m(3)) and O(3) (49 mu g/m(3)) levels were associated with increases in all arterial pressure parameters, ranging from 1.06 to 2.53 mmHg. PM(10) concentration was associated with early effects (lag 0), mainly on systolic blood pressure. However, O(3) was weakly associated most consistently with diastolic blood pressure and with late cumulative effects. Conclusions: Santo Andre traffic controllers presented higher blood pressure readings while working their outdoor shifts during periods of exposure to ambient pollutant fluctuations. However, PM(10) and O(3) induced cardiovascular effects demonstrated different time courses and end-point behaviors and probably acted through different mechanisms. (C) 2011 Elsevier Inc. All rights reserved.

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Linear IgA disease is a rare autoimmune subepidermal bullous disorder characterized by linear IgA deposits at the epidermal basement membrane zone. According to the literature, in patients who have linear IgA disease and become pregnant, the disease tends to improve. We report a case of linear IgA disease induced by pregnancy, successfully treated with dapsone and prednisone with no adverse effects observed in the patient and her newborns.

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Leptospirosis is a zoonotic infection associated with severe diseases such as leptospirosis pulmonary haemorrhage syndrome (LPHS). The cause of pulmonary haemorrhage is unclear. Understanding which mechanisms and processes are involved in LPHS will be important in treatment regimens under development for this life-threatening syndrome. In the present study, we evaluated 30 lung specimens from LPHS patients and seven controls using histology and immunohistochemistry (detection of IgM, IgG, IgA and C3) in order to describe the pathological features associated with this syndrome. Immunoglobulin deposits were detected on the alveolar surface in 18/30 LPHS patients. Three staining patterns were observed for the immunoglobulins and C3 in the lung tissues of LPHS patients: AS, delicate linear staining adjacent to the alveolar surface, which was indicative of a membrane covering the luminal surface of type I and II pneumocyte cells; S, heterogeneous staining which was sporadically distributed along the alveolar septum; and IA, weak, focal intra-alveolar granular staining. Human LPHS is associated with individual and unique histological patterns that differ from those of other causes of pulmonary haemorrhage. In the present study, it was found that the linear deposition of immunoglobulins (IgA, IgG and IgM) and complement on the alveolar surface may play a role in the pathogenesis of pulmonary haemorrhage in human leptospirosis.

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Peptides constitute the largest group of Hymenoptera venom toxins; some of them interact with GPCR, being involved with the activation of different types of leukocytes, smooth muscle contraction and neurotoxicity. Most of these toxins vary from dodecapeptides to tetradecapeptides, amidated at their C-teminal amino acid residue. The venoms of social wasps can also contains some tetra-, penta-, hexa- and hepta-peptides, but just a few of them have been structurally and functionally characterized up to now. Protonectin (ILG-TILGLLKGL-NH(2)) is a polyfunctional peptide, presenting mast cell degranulation, release of lactate dehydrogenase (LDH) from mast cells, antibiosis against Gram-positive and Gram-negative bacteria and chemotaxis for polymorphonucleated leukocytes (PMNL), while Protonectin (1-6) (ILGTIL-NH(2)) only presents chemotaxis for PMNL However, the mixture of Protonectin (1-6) with Protonectin in the molar ratio of 1:1 seems to potentiate the biological activities dependent of the membrane perturbation caused by Protonectin, as observed in the increasing of the activities of mast cell degranulation, LDH releasing from mast cells, and antibiosis. Despite both peptides are able to induce PMNL chemotaxis, the mixture of them presents a reduced activity in comparison to the individual peptides. Apparently, when mixed both peptides seems to form a supra-molecular structure, which interact with the receptors responsible for PMNL chemotaxis, disturbing their individual docking with these receptors. In addition to this, a comparison of the sequences of both peptides suggests that the sequence ILGTIL is conserved, suggesting that it must constitute a linear motif for the structural recognition by the specific receptor which induces leukocytes migration. (C) 2010 Elsevier Ltd. All rights reserved.

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Background: Splanchnic perfusion is prone to early injury and persists despite normalization of global hemodynamic variables in sepsis. Volume replacement guided by oxygen derived variables has been recommended in the management of septic patients. Our hypothesis was that a hypertonic isoneotic solution Would improve the benefits of crystalloids replacement guided by mixed venous oxygen saturation. Methods: Seventeen anesthetized and mechanically ventilated mongrel dogs received an intravenous infusion of live E. coli in 30 minutes. They were then randomized into three groups: control group (n = 3) bacterial infusion without treatment; normal saline (n = 7), initial fluid replacement with 32 mL/kg of normal saline during 20 minutes; hypertonic solution (n = 7), initial fluid replacement with 4 mL/kg of hypertonic solution during 5 minutes. After 30 and 60 Minutes, additional boluses of normal saline were administered when mixed venous oxygen saturation remained below 70%. Mean arterial pressure, cardiac output; regional blood flows, systemic and regional oxygen-derived variables, and lactate levels were assessed. Animals were observed for 90 minutes and then killed. Hystopathological analysis including apoptosis detection using terminal deoxynucleotidil transferase mediated dUTP-biotin nick end labeling was performed. Results: A hypodynamic septic shock was observed after bacterial infusion. Both the fluid-treated groups presented similar transient benefits in systemic and regional variables. A greater degree of gut epithelial cells apoptosis was observed in normal saline-treated animals. Conclusions: Although normalization of mixed venous oxygen saturation was not associated with restoration of markers of splanchnic or other systemic perfusion variables, the initial fluid savings with hypertonic saline and its latter effect on gut apoptosis may be of interest in sepsis management.

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The objective of this study is to evaluate the prevalence of antiphospholipid antibodies, mainly anti-beta(2)-glycoprotein I (anti-beta(2)-GPI), and their possible clinical and laboratory relevance in mixed connective tissue disease (MCTD). This study included 39 consecutive patients with MCTD (Kasukawa`s criteria) from January, 2005, to March, 2007, and compared them with 21 age- and sex-matched healthy controls. IgG and IgM anticardiolipin (aCL) and anti-beta(2)-GPI were measured by ELISA. Lupus anticoagulant (LA) was detected by functional coagulation tests. Medium to high titres of aCL and anti-beta(2)-GPI antibodies were found in sera from four (10.2%) MCTD patients. One of these patients was found to be positive for IgM aCL, IgM anti-beta(2)-GPI and LA antibodies simultaneously. Additionally, this patient had a previous history of foetal loss in the second trimester and new-onset pulmonary arterial hypertension (PAH). The other three patients had none of the manifestations of antiphospholipid syndrome (APS) or PAH. The mean value of IgG anti-beta(2)-GPI was higher among those MCTD patients with PAH than in the group without PAH (34.2 +/- 46.8 vs 12.3 +/- 9.1, P = 0.018). None of the controls were positive for antiphospholipid antibodies. High to moderate titres of anti-beta(2)-GPI as well as APS were rare in MCTD, and these antibodies may be correlated with the development of PAH in these patients. Lupus (2009) 18, 618-621.

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Objective To investigate whether the cox-2 inhibitor celecoxib has antidepressant effects in bipolar disorder (BD) patients during depressive or mixed phases. Methods We studied 28 DSM-IV BD patients who were experiencing a depressive or mixed episode and were on a stable dose of a mood stabilizer or atypical antipsychotic medication. Subjects were randomized to receive 6 weeks of double-blind placebo or celecoxib (400 mg/day) treatment. Current mood stabilizer or antipsychotic medication remained at the same doses during the trial. Results Intention-to-treat analysis showed that the patients receiving celecoxib had lower Hamilton Depression Rating Scale (HamD) scores after 1 week of treatment compared to the patients receiving placebo, but this difference was not statistically significant (p=0.09). The improvement in the first week of treatment was statistically significant when the analysis included only the subjects who completed the full 6-week trial (p=0.03). The two groups did not differ significantly on depressive or manic symptoms from the second week until the end of the trial. Celecoxib was well tolerated with the exception of two subjects who dropped out of the study due to rash. Conclusions Our findings suggest that adjunctive treatment with celecoxib may produce a rapid-onset antidepressant effect in BD patients experiencing depressive or mixed episodes. Copyright (C) 2008 John Wiley & Sons, Ltd.

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Background: The Flutter (R) VRP1 combines high frequency oscillation and positive expiratory pressure (PEP). Objective: To separately evaluate the effect of the Flutter (R) VRP1 components (high frequency oscillation and PEP) on mucus transportability in patients with bronchiectasis. Methods: Eighteen patients with bronchiectasis received sessions with the Flutter (R) VRP1 or PEP for 30 min daily in a randomized, crossover study. The treatment duration was four weeks with one of the therapies, one week of a ""wash-out"" period and followed by four more weeks with the other treatment. Weekly secretion samples were collected and evaluated for mucociliary relative transport velocity (RTV), displacement in a simulated cough machine (SCM) and contact angle measurement (CAM). For the proposed comparisons, a linear regression model was used with mixed effects with a significance level of 5%. Results: The Flutter (R) VRP1 treatment resulted in greater displacement in SCM and lower CAM when comparing results from the first (9.6 +/- 3.4 cm and 29.4 +/- 5.7 degrees, respectively) and fourth weeks of treatment (12.44 +/- 10.5 cm and 23.28 +/- 6.2, respectively; p < 0.05). There was no significant difference in the RTV between the treatment weeks for either the Flutter (R) VRP1 or PEP. Conclusion: The use of the Flutter (R) VRP1 for four weeks is capable of altering the respiratory secretion transport properties, and this alteration is related to the high frequency oscillation component. (C) 2011 Elsevier Ltd. All rights reserved.