2,519 research outputs found
A comparison of the Normal and Laplace distributions in the models of fuzzy probability distribution for portfolio selection
The propose of this work is applied the fuzzy Laplace distribution on a possibilistic mean-variance model presented by Li et al which appliehe fuzzy normal distribution. The theorem necessary to introduce the Laplace distribution in the model was demonstrated. It was made an analysis of the behavior of the fuzzy normal and fuzzy Laplace distributions on the portfolio selection with VaR constraint and risk-free investment considering real data. The results showns that were not difference in assets selection and in return rate, however, There was a change in the risk rate, which was higher in the Laplace distribution than in the normal distribution
Crystal structures and Hirshfeld surfaces of four methoxybenzaldehyde oxime derivatives, 2-MeO-XC6H3C=NOH (X = H and 2-, 3- and 4-MeO): different conformations and hydrogen-bonding patterns
The crystal structures of four (E)-meth-oxy-benzaldehyde oxime derivatives, namely (2-meth-oxy-benzaldehyde oxime, 1, 2,3-di-meth-oxy-benzaldehyde oxime, 2, 4-di-meth-oxy-benzaldehyde oxime, 3, and 2,5-di-meth-oxy-benzaldehyde oxime, 4, are discussed. The arrangements of the 2-meth-oxy group and the H atom of the oxime unit are s-cis in compounds 1-3, but in both independent mol-ecules of compound 4, the arrangements are s-trans. There is also a difference in the conformation of the two mol-ecules in 4, involving the orientations of the 2- and 5-meth-oxy groups. The primary inter-molecular O-H(oxime)⋯O(hy-droxy) hydrogen bonds generate C(3) chains in 1 and 2. In contrast, in compound 3, the O-H(oxime)⋯O(hy-droxy) hydrogen bonds generate symmetric R22(6) dimers. A more complex dimer is generated in 4 from the O-H(oxime)⋯O(hy-droxy) and C-H(2-meth-oxy)⋯O(hy-droxy) hydrogen bonds. In all cases, further inter-actions, C-H⋯O and C-H⋯π or π-π, generate three-dimensional arrays. Hirshfeld surface and fingerprint analyses are discussed.info:eu-repo/semantics/publishedVersio
Automatic Network Fingerprinting through Single-Node Motifs
Complex networks have been characterised by their specific connectivity
patterns (network motifs), but their building blocks can also be identified and
described by node-motifs---a combination of local network features. One
technique to identify single node-motifs has been presented by Costa et al. (L.
D. F. Costa, F. A. Rodrigues, C. C. Hilgetag, and M. Kaiser, Europhys. Lett.,
87, 1, 2009). Here, we first suggest improvements to the method including how
its parameters can be determined automatically. Such automatic routines make
high-throughput studies of many networks feasible. Second, the new routines are
validated in different network-series. Third, we provide an example of how the
method can be used to analyse network time-series. In conclusion, we provide a
robust method for systematically discovering and classifying characteristic
nodes of a network. In contrast to classical motif analysis, our approach can
identify individual components (here: nodes) that are specific to a network.
Such special nodes, as hubs before, might be found to play critical roles in
real-world networks.Comment: 16 pages (4 figures) plus supporting information 8 pages (5 figures
METHODS AIMED AT REDUCING THE RESIDUAL RISK OF PATHOGEN TRANSMISSION DURING PLATELET TRANSFUSION: A LITERATURE REVIEW
Objective: In the Brazilian public health system, sterile filtration is often used to prevent infections associated with platelet transfusion. The literature addressing this issue indicates that pathogen inactivation could be incorporated as an alternative to the development of individual tests and blood donor selection. The objective was to assess whether the use of platelets submitted to pathogen inactivation by photochemical methods could decrease the incidence of post-transfusion infections by viruses, bacteria or other pathogens compared to the use of platelet concentrate or platelets extracted by apheresis without photochemical treatment.Methods: A literature review from 1998 to 2015 was conducted. The scientific literature was surveyed using six electronic databases, two Internet search tools and a manual search of references, using specific search strategies for each database. The selected studies were assessed for quality according to a specific methodology. Data analysis was performed by observations made from the efficacy of the methods.Results: From a detailed analysis of 426 articles retrieved, 10 articles were selected for this review. Among the selected studies, seven studies were clinical trials, and three studies were systematic reviews in combination with meta-analysis. The outcomes analyzed included the reduction of the residual risk in pathogen transmission, mortality, occurrence of hemorrhagic events, corrected count increment (CCI) after 1 h, CCI after 24 h, and transfusion reactions.Conclusion: Differences were found in the quality of the included studies. Systematic reviews conducted on this topic, in alliance with political, social and administrative factors, will aid decision makers regarding its incorporation into the Brazilian Health System.Keywords: Blood Platelets, Platelet Transfusion, Platelet Transfusion/methods*, Riboflavin, Ultraviolet Rays, Photosensitizing Agents, Platelet Transfusion/adverse effect
Ab-initio study of model guanine assemblies: The role of pi-pi coupling and band transport
Several assemblies of guanine molecules are investigated by means of
first-principle calculations. Such structures include stacked and
hydrogen-bonded dimers, as well as vertical columns and planar ribbons,
respectively, obtained by periodically replicating the dimers. Our results are
in good agreement with experimental data for isolated molecules, isolated
dimers, and periodic ribbons. For stacked dimers and columns, the stability is
affected by the relative charge distribution of the pi orbitals in adjacent
guanine molecules. pi-pi coupling in some stacked columns induces dispersive
energy bands, while no dispersion is identified in the planar ribbons along the
connections of hydrogen bonds. The implications for different materials
comprised of guanine aggregates are discussed. The bandstructure of dispersive
configurations may justify a contribution of band transport (Bloch type) in the
conduction mechanism of deoxyguanosine fibres, while in DNA-like configurations
band transport should be negligible.Comment: 21 pages, 6 figures, 3 tables, to be published in Phys. Rev.
Antiparasitic Activity of Natural and Semi-Synthetic Tirucallane Triterpenoids from Schinus terebinthifolius (Anacardiaceae): Structure/Activity Relationships
Leishmaniasis and Chagas are diseases caused by parasitic protozoans that affect the poorest population in the World, causing a high mortality and morbidity. As a result of highly toxic and long-term treatments, the discovery of novel, safe and more efficacious drugs is essential. in this work, the in vitro antiparasitic activity and mammalian cytotoxicity of three natural tirucallane triterpenoids, isolated from leaves of Schinus terebinthifolius (Anacardiaceae), and nine semi-synthetic derivatives were investigated against Leishmania (L.) infantum and Trypanosoma cruzi. Trypomastigotes of T. cruzi were the most susceptible parasites and seven compounds demonstrated a trypanocidal activity with IC50 values in the range between 15 and 58 mu g/mL. Four compounds demonstrated selectivity towards the intracellular amastigotes of Leishmania, with IC50 values in the range between 28 and 97 mu g/mL. the complete characterization of triterpenoids was afforded after thorough analysis of nuclear magnetic resonance (NMR) data as well as electrospray ionization mass spectrometry (ESI-MS). Additionally, structure-activity relationships were performed using Decision Trees.Conselho Nacional de Desenvolvimento CientÃfico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG)Universidade Federal de São Paulo, Inst Ciencias Ambientais Quim & Farmaceut, BR-09972270 Diadema, SP, BrazilAdolfo Lutz Inst, Ctr Parasitol, BR-01246902 São Paulo, BrazilUniv Fed Paraiba, Ctr Ciencias Aplicadas & Educ, BR-58297000 Rio Tinto, BrazilUniv Fed Uberlandia, Inst Quim, BR-38400902 Uberlandia, MG, BrazilUniversidade Federal de São Paulo, Inst Ciencias Ambientais Quim & Farmaceut, BR-09972270 Diadema, SP, BrazilCNPq: 300546/2012-2CNPq: 471458/2012-0FAPESP: 2011/51739-0FAPESP: 2012/18756-1FAPESP: 2013/16320-4Web of Scienc
Brazilian recommendations on the safety and effectiveness of the yellow fever vaccination in patients with chronic immune-mediated inflammatory diseases
Background: In Brazil, we are facing an alarming epidemic scenario of Yellow fever (YF), which is reaching the most populous areas of the country in unvaccinated people. Vaccination is the only effective tool to prevent YF. In special situations, such as patients with chronic immune-mediated inflammatory diseases (CIMID), undergoing immunosuppressive therapy, as a higher risk of severe adverse events may occur, assessment of the risk-benefit ratio of the yellow fever vaccine (YFV) should be performed on an individual level. Main body of the abstract: Faced with the scarcity of specific orientation on YFV for this special group of patients, the Brazilian Rheumatology Society (BRS) endorsed a project aiming the development of individualized YFV recommendations for patients with CIMID, guided by questions addressed by both medical professionals and patients, followed an internationally validated methodology (GIN-McMaster Guideline Development). Firstly, a systematic review was carried out and an expert panel formed to take part of the decision process, comprising BRS clinical practitioners, as well as individuals from the Brazilian Dermatology Society (BDS), Brazilian Inflammatory Bowel Diseases Study Group (GEDIIB), and specialists on infectious diseases and vaccination (from Tropical Medicine, Infectious Diseases and Immunizations National Societies); in addition, two representatives of patient groups were included as members of the panel. When the quality of the evidence was low or there was a lack of evidence to determine the recommendations, the decisions were based on the expert opinion panel and a Delphi approach was performed. A recommendation was accepted upon achieving ≥80% agreement among the panel, including the patient representatives. As a result, eight recommendations were developed regarding the safety of YFV in patients with CIMID, considering the immunosuppression degree conferred by the treatment used. It was not possible to establish recommendations on the effectiveness of YFV in these patients as there is no consistent evidence to support these recommendations. Conclusion: This paper approaches a real need, assessed by clinicians and patient care groups, to address specific questions on the management of YFV in patients with CIMID living or traveling to YF endemic areas, involving specialists from many areas together with patients, and might have global applicability, contributing to and supporting vaccination practices. We recommended a shared decision-making approach on taking or not the YFV
Primary skin fibroblasts as a model of Parkinson's disease
Parkinson's disease is the second most frequent neurodegenerative disorder. While most cases occur sporadic mutations in a growing number of genes including Parkin (PARK2) and PINK1 (PARK6) have been associated with the disease. Different animal models and cell models like patient skin fibroblasts and recombinant cell lines can be used as model systems for Parkinson's disease. Skin fibroblasts present a system with defined mutations and the cumulative cellular damage of the patients. PINK1 and Parkin genes show relevant expression levels in human fibroblasts and since both genes participate in stress response pathways, we believe fibroblasts advantageous in order to assess, e.g. the effect of stressors. Furthermore, since a bioenergetic deficit underlies early stage Parkinson's disease, while atrophy underlies later stages, the use of primary cells seems preferable over the use of tumor cell lines. The new option to use fibroblast-derived induced pluripotent stem cells redifferentiated into dopaminergic neurons is an additional benefit. However, the use of fibroblast has also some drawbacks. We have investigated PARK6 fibroblasts and they mirror closely the respiratory alterations, the expression profiles, the mitochondrial dynamics pathology and the vulnerability to proteasomal stress that has been documented in other model systems. Fibroblasts from patients with PARK2, PARK6, idiopathic Parkinson's disease, Alzheimer's disease, and spinocerebellar ataxia type 2 demonstrated a distinct and unique mRNA expression pattern of key genes in neurodegeneration. Thus, primary skin fibroblasts are a useful Parkinson's disease model, able to serve as a complement to animal mutants, transformed cell lines and patient tissues
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