Alkane coiling in perfluoroalkane solutions: a new primitive solvophobic effect

In this work, we demonstrate that n-alkanes coil when mixed with perfluoroalkanes, changing their conformational equilibria to more globular states, with a higher number of gauche conformations. The new coiling effect is here observed in fluids governed exclusively by dispersion interactions, contrary to other examples in which hydrogen bonding and polarity play important roles. FTIR spectra of liquid mixtures of n-hexane and perfluorohexane unambiguously reveal that the population of n-hexane molecules in all-trans conformation reduces from 32% in the pure n-alkane to practically zero. The spectra of peffluorohexane remain unchanged, suggesting nanosegregatiori of the hydrogenated and fluorinated chains. Molecular dynamics simulatiOns support this analysis. The new solvophobic effect is prone to have a major impact on the structure, organization, and therefore thermodynamic properties and phase equilibria of, fluids involving mixed hydrogenated and fluorinated chains.Fundacao para a Ciencia e Tecnologia [UID/NAN/50024/2013, UID/QUI/0100/2013, SFRH/BPD/81748/2011

Systems involving hydrogenated and fluorinated chains: Volumetric properties of Perfluoroalkanes and Perfluoroalkylalkane Surfactants

As part of a combined experimental and theoretical study of the thermodynamic properties of perfluoroalkylalkanes (PFAAs), the liquid density of perfluorobutylpentane (F4H5), perfluorobutylhexane (F4H6), and perfluorobutyloctane (F4H8) was measured as a function of temperature from 278.15 to 353.15 K and from atmospheric pressure to 70 MPa. The liquid densities of n-perfluoropentane, n-perfluorohexane, n-perfluorooctane, and n-perfluorononane were also measured at room pressure over the same temperature range. The PVT behavior of the PFAAs was also studied using the SAFT-VR equation of state. The PFAA molecules were modeled as heterosegmented diblock chains, using different parameters for the alkyl and perfluoroalkyl segments, that were developed in earlier work. Through this simple approach, we are able to predict the thermodynamic behavior of the perfluoroalkylalkanes, without fitting to any experimental data for the systems being studied. Molecular dynamics simulations have also been performed and used to calculate the densities of the perfluoroalkylalkanes studied

Poly(N-isopropylacrylamide)-co-acrylamide hydrogels for the controlled release of bromelain from agroindustrial residues of Ananas comosus

This works reports the purification of bromelain extracted from Ananas comosus industrial residues by ethanol purification, its partial characterization from the crude extract as well as the ethanol purified enzyme, and its application onto poly(N-isopropylacrylamide)-co-acrylamide hydrogels. Bromelain was recovered within the 30–70 % ethanol fraction, which achieved a purification factor of 3.12-fold, and yielded more than 90 % of its initial activity. The resulting purified bromelain contained more than 360 U · mg−1, with a maximum working temperature of 60 °C and pH of 8.0. Poly(N-isopropylacrylamide)-co-acrylamide hydrogels presented a swelling rate of 125 %, which was capable of loading 56 % of bromelain from the solution, and was able to release up to 91 % of the retained bromelain. Ethanol precipitation is suitable for bromelain recovery and application onto poly(N-isopropylacrylamide)-co-acrylamide hydrogels based on its processing time and the applied ethanol prices8117191726CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE MINAS GERAIS - FAPEMIGsem informaçã

Poly(n-isopropylacrylamide)-co-acrylamide Hydrogels For The Controlled Release Of Bromelain From Agroindustrial Residues Of Ananas Comosus.

This works reports the purification of bromelain extracted from Ananas comosus industrial residues by ethanol purification, its partial characterization from the crude extract as well as the ethanol purified enzyme, and its application onto poly(N-isopropylacrylamide)-co-acrylamide hydrogels. Bromelain was recovered within the 30-70 % ethanol fraction, which achieved a purification factor of 3.12-fold, and yielded more than 90 % of its initial activity. The resulting purified bromelain contained more than 360 U · mg(-1), with a maximum working temperature of 60 °C and pH of 8.0. Poly(N-isopropylacrylamide)-co-acrylamide hydrogels presented a swelling rate of 125 %, which was capable of loading 56 % of bromelain from the solution, and was able to release up to 91 % of the retained bromelain. Ethanol precipitation is suitable for bromelain recovery and application onto poly(N-isopropylacrylamide)-co-acrylamide hydrogels based on its processing time and the applied ethanol prices.811719-172

Transport properties and Kondo correlations in nanostructures: the time-dependent DMRG method applied to quantum dots coupled to Wilson chains

We apply the adaptive time-dependent Density Matrix Renormalization Group method (tDMRG) to the study of transport properties of quantum-dot systems connected to metallic leads. Finite-size effects make the usual tDMRG description of the Kondo regime a numerically demanding task. We show that such effects can be attenuated by describing the leads by "Wilson chains", in which the hopping matrix elements decay exponentially away from the impurity ($t_n \propto \Lambda^{-n/2}$). For a given system size and in the linear response regime, results for $\Lambda > 1$ show several improvements over the undamped, $\Lambda=1$ case: perfect conductance is obtained deeper in the strongly interacting regime and current plateaus remain well defined for longer time scales. Similar improvements were obtained in the finite-bias regime up to bias voltages of the order of the Kondo temperature. These results show that, with the proposed modification, the tDMRG characterization of Kondo correlations in the transport properties can be substantially improved, while it turns out to be sufficient to work with much smaller system sizes. We discuss the numerical cost of this approach with respect to the necessary system sizes and the entanglement growth during the time-evolution.Comment: 10 pages, 9 figures. Updated: new section on finite bias adde

Тhe economic value of volunteering

Voluntary work is a non-remunerated activity, which is usually performed to satisfy a moral need of the individual as well as to contribute to the collective goal of the society. It usually leads to the creation of goods or services that would in a normal situation require the use of workforce that needs to be paid, meaning it would mean an expense. The goods and services produced through the voluntary work are usually not part of the official measures of production, but volunteers make significant contributions to the economy and society

Risk factors for physical disability in patients with leprosy: a systematic review and meta analysis

Abstract Importance: The World Health Organization (WHO) 2016–2020 Global Leprosy Strategy aims to reinvigorate efforts to control leprosy and avert leprosy disability to less than one per million population. Objective: This study aimed to identify systematically clinical factors associated with physical disability in patients with leprosy. Data source: Searches were performed in Scopus, PubMed and Web of Science databases to identify studies published up to May 2018, using the keywords leprosy and physical disability and related terms. Study selection: We included studies that evaluated patients using the WHO leprosy disability grading and reported the number of patients with and without disability by clinical characteristics. Data Extraction and Synthesis: The study was conducted following the Meta-Analysis of Observational Studies in Epidemiology (MOOSE) statement. We used the odds ratio (OR) as a measure of association between the clinical features and physical disability. Summary estimates were calculated using random-effects models. Main Outcome(s) and Measure(s): Our primary outcome was physical disability according the WHO disability classification. We evaluated the association between clinical features and physical disability. Results: Thirty-two studies were included in the systematic review. Males were more likely to have physical disability than females (pooled OR: 1.66; CI95% 1.43-1.93). Multibacillary (MB) leprosy were 4-fold more likely to have physical disability than paucibacillary (PB) leprosy 4 patients (pooled OR 4.32; CI95% 3.37-5.53). Patients having leprosy reactions were more likely to have disability (pooled OR 2.43, CI95% 1.35-4.36). Patients with lepromatous leprosy experienced 5- to 12-fold higher odds of disability. Conclusion and Relevance: This systematic review and meta-analysis confirms the strong association between the presence of physical disabilities and male gender, MB leprosy, leprosy reactions and lepromatous presentation. These findings can guide the development of targeted interventions to identify early individuals at greater risk of developing physical disabilities and education campaigns to promote early consultation to institute treatment for leprosy reactions and to prevent physical disability

Search for W' bosons decaying to an electron and a neutrino with the D0 detector

This Letter describes the search for a new heavy charged gauge boson W' decaying into an electron and a neutrino. The data were collected with the D0 detector at the Fermilab Tevatron proton-antiproton Collider at a center-of-mass energy of 1.96 TeV, and correspond to an integrated luminosity of about 1 inverse femtobarn. Lacking any significant excess in the data in comparison with known processes, an upper limit is set on the production cross section times branching fraction, and a W' boson with mass below 1.00 TeV can be excluded at the 95% C.L., assuming standard-model-like couplings to fermions. This result significantly improves upon previous limits, and is the most stringent to date.Comment: submitted to Phys. Rev. Let

A Survey on the Value Consciousness of Japanese Athletes

行為体系理論の立場から設定された4種の価値, スポーツ体系構成要因間の投入産出の相互交換, 及びR.ベネディクトの文化型にみられる日本的特性を手掛りにした調査の結果, わが国競技者(陸上競技, 野球, 剣道)の価値意識について次の事実が明らかになった。1.全体的な傾向についてみれば, スポーツ, チーム, 試合, 練習に関する価値については業績価値, 献身価値が多く選ばれた。これは競技スポーツの特性とよく合致している。指導者の資質, 年長者-年少者の関係についてみれば, 献身価値, 和合価値等の個別主義的価値への志向が多くみられたが, これはベラーの指摘する日本文化の伝統的特性と対応するものである。2.世代間の差についてみれば, スポーツ, チームに関してはOB, 現役とも業績価値, 献身価値という成就本位の価値に志向する者が多いが, OBは現役よりも和合価値を, 現役はOBよりも充足価値を選ぶ者が多い。集団を構成する人間関係についてみれば, 年長者-年少者という先天的属性のみにかかわる上下関係では双方とも和合価値を志向し, 指導者-競技者という機能的上下関係に関してはOBは現役よりも厳しい献身価値を, 現役はOBよりも暖かい和合価値や, 自由な充足価値をより多く志向する。これはOB, 現役が競技者としておかれた社会的文化的背景の差, また監督経験の有無の差によるものであろう。3.種目間の差についてみれば, 陸上競技は合理的な業績価値を, 野球はスポーツに対しては和合価値を, チームや連帯, 指導者に関しては克服価値を他種目より多く選ぶ。これは個人の記録の客観比較である陸上競技と, 監督による統制の強いチーム競技である野球との間のスポーツ文化としての特質の