Indium phthalocyanines with different axial ligands: a study of the influence of the structure on the photophysics and optical limiting properties

The photophysical properties of four axially substituted indium phthalocyanines, namely, 2,(3)-tetra- tert-butyl-phthalocyaninato indium chloride ( 1), 2,(3)-tetra-[(3,5-di- tert-butyl)-phenyloxy]-phthalocyaninato indium bromide ( 2), 2,(3)-tetra-[(3,5-di- tert-butyl)-phenyloxy]-phthalocyaninato indium iodide ( 3), and 2,3-octa-[(2-hexyl)-ethyloxy]-phthalocyaninato indium trifluoroacetate ( 4), have been investigated, and their optical limiting properties with nanosecond light pulses were evaluated. All complexes behave as reverse saturable absorbers in the range of 400-625 nm due to a triplet-triplet excited-state transition. Excited-state absorption cross sections and triplet state lifetimes are not significantly affected by the nature of the axial ligand. On the other hand, remarkable differences in the variation of nonlinear transmittance are observed for 1- 4 due to significantly different intersystem crossing rates. Heavier axial ligands in phthalocyanines 2 and 3 produce the largest variations of nonlinear transmission (heavy-atom effect). Complex 1 in polystyrene matrix shows reversible nonlinear absorption when incident fluence does not exceed 0.025 J cm (-2).     

Primes between consecutive squares and the Lindelöf hypothesis

At present noone knows an unconditional proof that between two consecutive squares there is always a prime number. In a previous paper the author proved that, under the assumption of the Lindelöf hypothesis, each of the intervals [n ², (n+1)²] ? [1,N], with at most O(N ^?) exceptions, contains the expected number of primes, for every constant ? > 0. In this paper we improve the result by weakening the hypothesis in two different ways.     

Generalized Nash equilibria for SaaS/PaaS Clouds

Cloud computing is an emerging technology that allows to access computing resources on a pay-per-use basis. The main challenges in this area are the efficient performance management and the energy costs minimization.     

Targeted analysis reveals alteration in pathway in 5p minus individuals

Cri du Chat or 5p minus (5p−) syndrome is characterized by a deletion located on the chromosome 5 short (−p) arm and has an incidence rate of 1 in 50,000 individuals worldwide. This disease manifests in disturbances across a range of systems biochemicals. Therefore, a targeted metabolomics analysis was evaluated in patients with 5p− syndrome to help unravel the biochemical changes that occur in this disease. Urine samples were collected from people of both sexes aged 1–38 years old and analyzed by ultra-performance liquid chromatography coupled to mass spectrometry. Student' statistical test, metabolomic pathway analysis and metabolite set enrichment analysis were applied to the data. Alterations of some amino acids and amine biogenics levels were found in Cri du Chat Syndrome individuals. The alteration of most of these metabolites is associated with energy recuperation and glycolysis. In general, we found the catabolism of some metabolic pathways to be affected in 5p− patients.     

The Crossed Product by a Partial Endomorphism

Given a closed ideal I in a C*-algebra A, an ideal J (not necessarily closed) in I , a *-homomorphism α : A → M(I ) and a map L : J → A with some properties, based on earlier works of Pimsner and Katsura, we define a C*-algebra which we call the Crossed Product by a Partial Endomorphism. We introduce the Crossed Product by a Partial Endomorphism induced by a local homeomorphism σ : U → X where X is a compact Hausdorff space and U is an open subset of X. A bijection between the gauge invariant ideals of and the σ, σ^-1- invariant open subsets of X is showed. If (X, σ) has the property that is topologically free for each closed σ, σ^-1-invariant subset X′ of X then we obtain a bijection between the ideals of and the open σ, σ^-1-invariant subsets of X. *Partially supported by CNPq. **Supported by CNPq.     

Synthesis of new arylbenzofurodiazepin-6-ones

Two new tetracyclic structures, containing the diazepine ring, were synthesized: 5,6-dihydro-12H-benzofuro[3,2-b][1,5]benzodiazepin-6-one and 5,6-dihydro-12H-benzofuro[3,2-b]pyrido[3,2-f][1,5]diazepin-6-one. Thus N-(2-haloaryl)-2-[(2-cyanophenyl)oxy]acetamides were cyclized to the corresponding N-(2-haloaryl)-3-amino-2-benzofurancarboxamides and then, through the formation of the central diazepine ring, to the title compounds. Formation of the diazepine ring took place only when an electron-withdrawing group was present in the molecule to facilitate the nucleophilic attack of an amine in the benzofuran intermediate.     

Electrochemical Immunosensor Made with Zein-based Nanofibers for On-site Detection of Aflatoxin B1

A disposable electrochemical immunosensor for on-site detection of aflatoxin B1(AFB1), one of the most toxic mycotoxins in agri-food products, was fabricated through a low-cost cut-printing method and then modified with zein/polypyrrole(PPy) electrospun nanofibers onto which anti-AFB1 monoclonal antibodies were immobilized covalently. Fabrication was possible with an innovative and simple approach to adsorb nanofibers onto the working electrode during electrospinning. Electrochemical impedance spectroscopy was employed as the principle of detection, and the data collected with a portable potentiostat were treated with information visualization techniques. The nanostructured immunosensor showed a high sensitivity for AFB1 with a linear detection range from 0.25 to 10 ng mL⁻¹ and a theoretical limit of detection of 0.092 ng mL⁻¹, which is adequate to detect AFB1 in food, according to regulatory agencies.     

Information Theory for Biological Sequence Classification: A Novel Feature Extraction Technique Based on Tsallis Entropy

In recent years, there has been an exponential growth in sequencing projects due to accelerated technological advances, leading to a significant increase in the amount of data and resulting in new challenges for biological sequence analysis. Consequently, the use of techniques capable of analyzing large amounts of data has been explored, such as machine learning (ML) algorithms. ML algorithms are being used to analyze and classify biological sequences, despite the intrinsic difficulty in extracting and finding representative biological sequence methods suitable for them. Thereby, extracting numerical features to represent sequences makes it statistically feasible to use universal concepts from Information Theory, such as Tsallis and Shannon entropy. In this study, we propose a novel Tsallis entropy-based feature extractor to provide useful information to classify biological sequences. To assess its relevance, we prepared five case studies: (1) an analysis of the entropic index q; (2) performance testing of the best entropic indices on new datasets; (3) a comparison made with Shannon entropy and (4) generalized entropies; (5) an investigation of the Tsallis entropy in the context of dimensionality reduction. As a result, our proposal proved to be effective, being superior to Shannon entropy and robust in terms of generalization, and also potentially representative for collecting information in fewer dimensions compared with methods such as Singular Value Decomposition and Uniform Manifold Approximation and Projection.