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We study the pion electromagnetic half-off-shell form factors $F_1$ and $F_2$ using an exactly solvable manifestly covariant model of a $(3+1)$ dimensional fermion field theory. The model provides a three-dimensional imaging of $F_1$ and $F_2$ as a function of $(Q^2,t)$, which are constrained by the Ward-Takahashi identity. The normalization of the charge form factor $F_1$ is fixed by $F_1(Q^2=0, t=m^2_\pi)=1$ while the other form factor $F_2$ vanishes, i.e. $F_2(Q^2, t=m^2_\pi)=0$ for any value of $Q^2$ due to the time-reversal invariance of the strong interaction. The new form factor defined by $g(Q^2,t)=F_2(Q^2,t)/(t- m^2_\pi)$ is however measurable in the on-mass-shell limit. We note that $g(Q^2=0, t=m^2_\pi)$ is related with the pion charge radius.

Sulfamethoxazole (SMZ) is a synthetic broad-spectrum antibiotic of biopharmaceutical classification system (BCS) class IV, with both low solubility and permeability, requiring probably higher drug doses in orally-administered formulations to promote an expected systemic absorption. To overcome such limitations and especially to increase its solubility, this study has a main purpose of the development of novel optimized crystalline forms of SMZ. Herein, two crystalline salts of SMZ (SMZBr and SMZNO3) have been synthesized from solution crystallization and characterized using X-ray (single and powder), spectroscopic (infrared, FT-IR) and thermal (DSC and TGA) techniques. Furthermore, a solubility study was performed in pure water and compared with the SMZCl salt and SMZ form I. It was observed that the SMZBr salt exhibits phase stability in water media and shows enhanced solubility compared to the SMZCl salt and SMZ form I. Additionally, a qualitative litmus paper test was employed to verify the volatiles released during the thermal drug degradation.

Selecting a trait linked to metabolic pathways that enhance resistance and tolerance to biotic and abiotic stresses may be an excellent alternative. A practical approach to increase the productivity of annual crops is to maximize the photosynthetic efficiency in plant breeding. The purpose of this study was to discriminate common bean genotypes during physiological senescence with regard to the stay-green trait and analyze its effects on other traits of agronomic interest. Ten common bean genotypes were analyzed in a randomized complete block design with three replications. The stay-green trait was assessed by visual scores at harvest. The chlorophyll a content, chlorophyll b and green pod color were also evaluated during senescence (75, 80, 85, 90, and 95 days after sowing). Pod maturation of all evaluated genotypes was standard when they reached 95 days after sowing. The stay - green feature was detected only in the genotypes BRS Expedito, FT - Tarumã and BAF071. Genetic variability in the mechanisms related to late senescence is indicated by: i) a high initial chlorophyll a content; and ii) reduced chlorophyll degradation throughout senescence. Plants with stay-green properties were significantly correlated with a lower incidence and severity of plant pathology, greater stem diameter, and higher grain yield. Selecionar uma característica relacionada às vias metabólicas responsáveis pelo aumento da resistência e/ou tolerância a estresses bióticos e abióticos pode ser uma excelente alternativa no melhoramento de plantas. Uma abordagem prática para aumentar a produtividade das culturas anuais é maximizar a eficiência fotossintética. O objetivo do trabalho foi discriminar genótipos de feijão durante a senescência fisiológica quanto ao caráter stay-green e correlacionar os efeitos sobre outros caracteres de interesse agronômico. Foram avaliados dez genótipos de feijão submetidos ao delineamento de blocos casualizados com três repetições. O caráter stay-green foi mensurado por escores de notas visuais na colheita. Também foram avaliados o teor de clorofila a, teor de clorofila b e coloração verde do legume no decorrer da senescência (75, 80, 85, 90, 95 dias após semeadura). A maturação dos legumes foi padrão para todos os genótipos avaliados. Os genótipos BRS Expedito, FT - Tarumã e BAF071 apresentaram stay-green, diferentemente dos demais. A variabilidade genética nos mecanismos relacionados a senescência tardia, são detectadas pela: i) elevado teor de clorofila a inicial; e ii) reduzida degradação de clorofila ao longo da senescência. As plantas com stay-green apresentaram correlações significativas com menor incidência e severidade de fitopatologias, maior diâmetro do caule e rendimento de grãos.

The electromagnetic form factors of a composite vector particle within the light-front formulation of the Mandelstam formula is investigated. In order to extract the form factors from the matrix elements of the plus component of the current in the Drell-Yan frame, where the momentum transfer is chosen such that $q^+=q^0+q^3=0$, one has in principle the freedom to choose between different linear combinations of matrix elements of the current operator. The different prescriptions to calculate the electromagnetic form factors, $G_0,G_1$ and $G_2$, i.e., charge form factor, magnetic and quadrupole respectively. If the covariance is respected, all prescriptions give the same results, misfortune, is not the situation, the light-front approach produce different results, which depend of the prescriptions as utilized to extract the electromagnetic form factors in the case of the spin-1 particles. The main differences of the prescriptions appear because of the light-front matrix elements of the electromagnetic current are contaminated by the zero-modes contributions to the same with the plus component of the matrix elements of the electromagnetic current. However, the Inna Grach prescription is immune to the zero-modes contributions to the electromagnetic current, then the electromagnetic form factors extracted with that prescriptions do not have zero-modes contribution and give the same result compared with the instant form quantum field theory. Another's prescriptions with the light-front approach are contaminated by the zero-modes contributions to the matrix elements of the electromagnetic current with the plus component of the current., Use elsevier style.1 latex file and 10 figures eps. Revised version. To appear Phys. Lett. B. (2018)

TPS5617 Background: Despite therapeutic advances in ovarian cancer, platinum-resistant recurrent ovarian cancer (PROC) remains an area of high unmet clinical need and there is an urgent need for new treatments to further improve clinical outcomes. Addition of bevacizumab to non-platinum-based chemotherapy significantly improved PFS in patients with PROC but did not show a clear OS benefit. Thus far, the combination of paclitaxel and bevacizumab has shown the most promise in treatment of PROC, although the proportion of patients eligible for bevacizumab is limited by treatment-associated toxicities. Combination of the anti-PD-1 antibody pembrolizumab with weekly paclitaxel showed antitumor activity and manageable toxicity in patients with PROC in a single-arm, phase 2 study (Wenham Int J Gynecol Cancer 2018). The current study ENGOT-ov65/KEYNOTE-B96 (NCT05116189) compares the efficacy and safety of the addition of pembrolizumab to standard of care chemotherapy (weekly paclitaxel) with/without bevacizumab vs placebo plus weekly paclitaxel with/without bevacizumab in patients with PROC. Methods: In this randomized, placebo-controlled, double-blind, phase 3 study, eligible patients are aged ≥18 y with histologically confirmed epithelial ovarian, fallopian tube, or primary peritoneal carcinoma with 1-2 prior lines of systemic therapy, including at least 1 prior platinum-based therapy with ≥4 cycles in first line. Patients must have platinum-resistant disease (radiographic evidence of PD ≤6 mo after last platinum-based therapy dose), be eligible for paclitaxel (with/without bevacizumab per investigator discretion), have ECOG PS ≤1, radiographically evaluable disease per RECIST v1.1, and have a tumor sample for central evaluation of PD-L1 status. Approximately 616 patients will be randomized 1:1 to receive pembrolizumab 400 mg IV or placebo Q6W for up to 18 cycles (̃2 y) plus paclitaxel 80 mg/m2 on days 1, 8, and 15 of each Q3W cycle (with/without bevacizumab 10 mg/kg Q2W per investigator discretion) until PD or unacceptable toxicity. Randomization is stratified by planned bevacizumab use (yes vs no), region (US vs Europe vs rest of world), and PD-L1 status (combined positive score [CPS] < 1 vs CPS 1- < 10 vs CPS ≥10). Tumor PD-L1 status is determined using the PD-L1 IHC 22C3 pharmDx (Investigational Use Only) diagnostic kit. Tumor imaging is performed Q9W from randomization to week 54 and Q12W thereafter. The primary endpoint is PFS per RECIST version 1.1 by investigator review in patients with tumor PD-L1 CPS ≥1 and in all patients. Secondary endpoints are OS in patients with tumor PD-L1 CPS ≥1 and in all patients, PFS per RECIST version 1.1 by blinded independent central review in patients with tumor PD-L1 CPS ≥1 and in all patients, safety, and patient-reported outcomes. Enrollment is ongoing. Clinical trial information: NCT05116189.

This study aimed to optimize the synthesis of a cosmetic ester (decyl oleate) catalyzed by immobilized lipase from Thermomyces lanuginosus (TLL) on amino-functionalized rice husk silica (Amino–SiO2), i.e. a homemade biocatalyst prepared via ionic adsorption. Functionalized support has been characterized by ATR–FTIR, TGA–DTA, and TEM analyses. The effect of important parameters on ester synthesis has been evaluated through a full factorial design in Central Composite Rotatable Design (CCRD) mode. Under optimal experimental conditions, maximum ester conversion percentage of 87% was observed after 105 and 180 min of reaction time in iso-octane and solvent-free systems, respectively. However, similar reaction rates of around 10 mM/min were obtained for both reaction systems. Ester synthesis in a solvent-free system is a kinetically controlled process, which has been confirmed by calculating its Damkohler number (Da = 7.63 × 10−5). Reusability tests showed that the biocatalyst retained all of its original activity after eight successive reaction cycles in a solvent-free system. These results show that this homemade biocatalyst can be successfully used in cosmetic ester synthesis through a clean technology process due to its high catalytic activity and reusability.

In this paper we present the mass matrices and mass eigenstates for the CP-even neutral scalars in the minimal 331 model (m331) and its self-interactions, showing that the m331 automatically reproduces the Higgs potential of the Standard Model. We also present a method to generate numerical solutions for the quarks and leptons masses and their mixings, which we apply to study FCNC processes, being to calculate the contributions of all exotic neutral particles of the m331 to the mass differences in meson oscillations., 36 pages, 12 figures

The soft gluon limit of the longitudinal part of the quark-gluon vertex is studied by resorting to non-perturbative approaches to Quantum Chromodynamics (QCD). Based on a Slavnov-Taylor identity (STI), the longitudinal form factors is expressed in terms of the quark-ghost kernel, the quark self energy and the quark wave function. An exact relation between the non-vanishing longitudinal form factors is derived for the soft gluon limit and explored to understand the behaviour of the vertex. Within a Ball-Chiu vertex, the form factor $\lambda_1$ was analysed using recent lattice simulations for full QCD for the soft gluon limit. The lattice data shows that the gluon propagator resumes the momentum dependence of such component of the vertex. This connection is understood via a fully dressed one-loop Bethe-Salpeter equation. The behaviour of the remaining longitudinal form factors $\lambda_2(p^2)$ and $\lambda_3(p^2)$ is investigated combining both the information of lattice simulations and the derived relations based on the STI., Comment: Accepted for publication on EPJC

Mechanochemistry is addressed here for the green formation of a 1:1 pharmaceutical cocrystal involving the antifungal prodrug 5-Fluorocytosine (5-FC) and the antineoplastic drug 5-Fluorouracil (5-FU). Crystalline material of this drug-drug cocrystal (DDC) was previously obtained by slow evaporation from solution (SES) and was then structurally analyzed. In this paper, neat grinding and solvent-drop grinding (SDG) were applied in an attempt to achieve a route for the supramolecular synthesis of this cocrystal, exhibiting suitable yield and amount for solid characterization, which were not achieved via the SES method. SDG provided the solid drug-drug cocrystal form. The resulting material had its physical stability monitored for 2 years and was then evaluated by a range of analytical technologies: X-ray powder diffraction, differential scanning calorimetry, hot-stage microscopy, thermogravimetric, and spectroscopic analysis. The new cocrystal proved to be stable for 6 months and in environments with high relative humidity. In this sense, it is believed that the new DDC is a potential model system which could be used as a base for further developments in the field, for other molecules or in relation to the feasibility of using this cocrystal therapeutically.

Levofloxacin, the levo-isomer of the antibiotic ofloxacin, can crystallize into two different hydrate forms, the monohydrate and the hemihydrate. Although these forms are well characterized, little is known about their anhydrous structures besides the study of Singh and Thakur using crystal structure prediction. In order to solve this issue, this paper proposes the use of high-temperature powder X-ray diffraction to determine the anhydrous structures of the levofloxacin forms termed in the literature as α and γ, herein obtained by heating of the levofloxacin monohydrate and hemihydrate, respectively. These are the first levofloxacin anhydrates whose structures could be solved. To support our results, the dehydration process has been also evaluated by means of differential scanning calorimetry, thermogravimetric analysis, and hot-stage polarized microscopy. The resulting X-ray structures differ from the ones reported as the best-predicted solution, although the predicted work had predicted similar structur...

We study the nucleon electromagnetic (EM) form factors in symmetric nuclear matter as well as in vacuum within a light-front approach using the in-medium inputs calculated by the quark-meson coupling model. The same in-medium quark properties are used as those used for the study of in-medium pion properties. The zero of the proton EM form factor ratio in vacuum, the electric to magnetic form factor ratio $��_p G_{Ep}(Q^2)/G_{Mp}(Q^2)$ ($Q^2 = -q^2 > 0$ with $q$ being the four-momentum transfer), is determined including the latest experimental data by implementing a hard constituent quark component in the nucleon wave function. A reasonable fit is achieved for the ratio $��_pG_{Ep}(Q^2)/G_{Mp}(Q^2)$ in vacuum, and we predict that the $Q_0^2$ value to cross the zero of the ratio to be about 15 GeV$^2$. In addition the double ratio data of the proton EM form factors in $^4$He and H nuclei, $[G^{^4{\rm He}}_{Ep}(Q^2)/G^{^4{\rm He}}_{Mp}(Q^2)]/[G^{^1{\rm H}}_{Ep}(Q^2)/G^{^1{\rm H}}_{Mp}(Q^2)]$, extracted by the polarized ($\vec{e}, e' \vec{p}$) scattering experiment on $^4$He at JLab, are well described. We also predict that the $Q_0^2$ value satisfying $��_pG_{Ep}(Q_0^2)/G_{Mp}(Q_0^2) = 0$ in symmetric nuclear matter, shifts to a smaller value as increasing nuclear matter density, which reflects the facts that the faster falloff of $G_{Ep}(Q^2)$ as increasing $Q^2$ and the increase of the proton mean-square charge radius. Furthermore, we calculate the neutron EM form factor double ratio in symmetric nuclear matter for $0.1 < Q^2 < 1.0$ GeV$^2$. The result shows that the neutron double ratio is enhanced relative to that in vacuum, while for the proton it is quenched, and agrees with an existing theoretical prediction., 39 pages, 11 figures. Revtex style. Title change, and news results added. To appear Nuclear Physics A

A aceitação da ideia de planejamento, nas sociedades ocidentais, vem evoluindo segundo um padrão que se pode caracterizar como dialético. O planejamento tomou-se difundido, inicialmente, a partir de uma visão racional compreensiva, introduzida nos anos cinquenta, que dava ênfase à mudança guiada por uma unidade organizacional central, responsável pela elaboração de projeções a partir das quais produzia documentos detalhados cujas recomendações deveriam ser rigidamente implementadas pelas unidades executivas. Compreendendo as fases de definição de objetivos, identificação de alternativas e escolha da opção que maximizava os resultados desejados, este tipo de planejamento requeria uma realização sequencial dessas fases, de modo que cada nova etapa só se iniciava quando a anterior houvesse sido concluída. Prevendo ainda a possível repetição de todo o ciclo, no final, para utilizar os benefícios da retroalimentação,- essa abordagem compreensiva é fortemente dependente de informação abrangente e rigorosa.

Ethambutol (ETB) is a chiral dibasic compound formulated and marketed as the (S,S)-ethambutol dihydrochloride, (S,S)-EDH, to treat tuberculosis. It is administered orally in a solid formulation composed of isoniazid, rifampicin, and pyrazinamide as a fixed-dose combination tablet. Because of its high hygroscopicity, (S,S)-EDH is known for catalyzing the degradation of isoniazid by rifampicin to yield isonicotinyl hydrazone. In order to avoid or even minimize these mutual drug–drug interactions, in this work we have focused on the development of less hygroscopic multicomponent solid forms of ETB. Four salts of this drug, namely, oxalate (ETBOXA), maleate, terephthalate, and trichloroacetate, were prepared via supramolecular synthesis by the slow evaporation method and characterized by X-ray diffraction (single crystal X-ray diffraction, powder X-ray diffraction), spectroscopic (Fourier transform-infrared), and thermal (thermogravimetric analysis, differential scanning calorimetry, hot stage microscopy) tec...

We propose a medium-modified holographic-hadron dynamics suitable for the study of symmetric nuclear matter, with a key property of a simple law for the evolution of the five dimensional mass with the scalar background field. We show that the model satisfies symmetric nuclear matter constraints, namely, incompressibility and density dependence of the pressure, with only three free adjustable parameters fitted to the free nucleon mass and the nuclear matter saturation properties. We found that the holographic nucleon swells and the UV behavior of the associated string amplitude is damped, with the scaling property at short distances softened. Both effects can also generate observable consequences reflecting an average leakage of partons to the nuclear medium when density is increased, in the route towards the deconfinement of the internal nucleon degrees of freedom. Keywords: AdS/QCD models, Nuclear matter, Equations of state

β-glucosidases (EC 3.2.1.21) have been described as essential to second-generation biofuel production. They act in the last step of the lignocellulosic saccharification, cleaving the β - 1,4 glycosidic bonds in cellobiose to produce two molecules of glucose. However, β-glucosidases have been described as strongly inhibited by glucose, causing an increment of cellobiose concentration. Also, cellobiose is an inhibitor of other enzymes used in this process, such as exoglucanases and endoglucanases. Hence, the engineering of thermostable and glucose-tolerant β-glucosidases has been targeted by many studies. In this study, we performed high sampling accelerated molecular dynamics for a wild glucose-tolerant GH1 β-glucosidase (Bgl1A), a wild non-tolerant (Bgl1B), and a set of glucose-tolerant Bgl1B's mutants: V302F, N301Q/V302F, F172I, V227M, G246S, T299S, and H228T. Our results suggest that point mutations promissory to induce glucose tolerance trend to enhance the mobility of the flexible loops around the active site. Mutations affected B and C loops regions, and an αβ-hairpin motif between them. Conformational clusters and free energy landscape profiles suggest that the mobility acquired by mutants allows a higher closure of the substrate channel. This closure is compatible with a higher impedance for glucose entrance and stimulus of its withdrawal. Based on mutants' structural analyses, we inferred that both the direct stereochemical effect on the glucose path and the changes in the mobility affect glucose tolerance. We hope these results be useful for the rational design of glucose-tolerant and industrially promising enzymes.Communicated by Ramaswamy H. Sarma.

Este capitulo busca aproximar as reflexoes no campo da inovacao e propriedade intelectual para estudo do caso de tecnologia agropecuaria. Partindo do conceito de paradigma tecnologico esbocamos algumas consideracoes sobre os processos de melhoramento de cultivares com especial atencao para o caso do BRS-Para, uma variedade de acai desenvolvida pela Embrapa Amazonia Oriental com o objetivo de potencializacao produtiva e agricola da variedade.

Background Protein engineering has many applications for industry, such as the development of new drugs, vaccines, treatment therapies, food, and biofuel production. A common way to engineer a protein is to perform mutations in functionally essential residues to optimize their function. However, the discovery of beneficial mutations for proteins is a complex task, with a time-consuming and high cost for experimental validation. Hence, computational approaches have been used to propose new insights for experiments narrowing the search space and reducing the costs. Results In this study, we developed Proteus (an acronym for Protein Engineering Supporter), a new algorithm for proposing mutation pairs in a target 3D structure. These suggestions are based on contacts observed in other known structures from Protein Data Bank (PDB). Proteus’ basic assumption is that if a non-interacting pair of amino acid residues in the target structure is exchanged to an interacting pair, this could enhance protein stability. This trade is only allowed if the main-chain conformation of the residues involved in the contact is conserved. Furthermore, no steric impediment is expected between the proposed mutations and the surrounding protein atoms. To evaluate Proteus, we performed two case studies with proteins of industrial interests. In the first case study, we evaluated if the mutations suggested by Proteus for four protein structures enhance the number of inter-residue contacts. Our results suggest that most mutations proposed by Proteus increase the number of interactions into the protein. In the second case study, we used Proteus to suggest mutations for a lysozyme protein. Then, we compared Proteus’ outcomes to mutations with available experimental evidence reported in the ProTherm database. Four mutations, in which our results agree with the experimental data, were found. This could be initial evidence that changes in the side-chain of some residues do not cause disturbances that harm protein structure stability. Conclusion We believe that Proteus could be used combined with other methods to give new insights into the rational development of engineered proteins. Proteus user-friendly web-based tool is available at .

Chromium-doped $$\alpha$$ - $$\hbox {Al}_{2}\hbox {O}_{3}$$ powder was synthesized by a modified sol–gel method using poly(vinyl alcohol) aqueous solutions and metal nitrate precursors. The synthesis process is simple, is of low cost and produced final crystals with cubic shape as confirmed by X-ray diffraction. The morphology of the samples verified by scanning electron microscopy showed slabs with thickness below 1 $$\upmu {\mathrm{m}}$$ , formed by interconnected long grains of typical thickness of around 200 $${\mathrm{nm}}$$ , showing growth of the grains as followed by thermogravimetric analysis. Luminescence characteristics of $$\hbox {Cr}^{3+}$$ were detected and analyzed as a function of the concentration of chromium using photoacoustic and photoluminescence spectroscopies.

The Simultaneous Localization and Mapping (SLAM) problem is recurrent in today's robotics. One challenge of it is the extensive computational cost to create complex maps in real-time. Various applications, mainly search and rescue operate in GPS denied scenarios, with possible difficulty communicating with an external base. A portable SLAM system capable of being run in a microcomputer would greatly help such operations. This paper mentions the unfinished into this topic and discusses further steps that shall be taken in the upcoming months.

Understanding the origin and dynamics of hadron structure and in turn that of atomic nuclei is a central goal of nuclear physics. This challenge entails the questions of how does the roughly 1 GeV mass-scale that characterizes atomic nuclei appear; why does it have the observed value; and, enigmatically, why are the composite Nambu-Goldstone (NG) bosons in quantum chromodynamics (QCD) abnormally light in comparison? In this perspective, we provide an analysis of the mass budget of the pion and proton in QCD; discuss the special role of the kaon, which lies near the boundary between dominance of strong and Higgs mass-generation mechanisms; and explain the need for a coherent effort in QCD phenomenology and continuum calculations, in exa-scale computing as provided by lattice QCD, and in experiments to make progress in understanding the origins of hadron masses and the distribution of that mass within them. We compare the unique capabilities foreseen at the electron-ion collider (EIC) with those at the hadron-electron ring accelerator (HERA), the only previous electron-proton collider; and describe five key experimental measurements, enabled by the EIC and aimed at delivering fundamental insights that will generate concrete answers to the questions of how mass and structure arise in the pion and kaon, the Standard Model's NG modes, whose surprisingly low mass is critical to the evolution of our Universe., Comment: 16 pages, 12 figures, to appear in the European Physical Journal A - "Hadrons and Nuclei"

Porous silicon layers were embedded with ZnTe using the isothermal close space sublimation technique. The presence of ZnTe was demonstrated using cross-sectional energy dispersive spectroscopy maps. ZnTe embedded samples present intense room temperature photoluminescence along the whole visible range. We ascribe this PL to ZnTe nanocrystals of different sizes grown on the internal pore surface. Such crystals, with different orientations and sizes, were observed in transmission electron microscopy images, while transmission electron diffraction images of the same regions reveal ZnTe characteristic patterns., This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in (Applied Physics Letters 100, 263110 (2012)) and may be found at (https://aip.scitation.org/doi/full/10.1063/1.4731276)

Isothermal Close Space Sublimation (ICSS) technique was used for embedding porous silicon (PS) films with ZnTe. It was studied the influence of the preparation conditions and in particular of a chemical etching step before the ZnTe growth, on the composition profile and final porosity of ZnTe embedded PS. The structure of the embedded material was determined by x-ray diffraction analysis while the thickness of the samples was determined by scanning electron microscopy (SEM). Rutherford backscattering (RBS) and Energy Dispersive (EDS) spectrometries allowed determining the composition profiles. We conclude that the etching of the PS surface before the ZnTe growth has two main effects: the increase of the porosity and enhancing the reactivity of the inner surface. It was observed that both effects benefit the filling process of the pores. Since RBS and EDS cannot detect the porosity in the present system, we explore the evolution of porosity by the fitting of the UV-VIS reflectance spectra. The atomic percent determined with this method was in relatively good agreement with that obtained from the RBS and EDS measurements., This article appeared in Microporous and Mesoporous Materials 188 2014 93 98 and may be found at www.sciencedirect.com/science/article/pii/S138718111400019

We investigate the pion electromagnetic half off-shell form factors, which parametrize the matrix element of the charged pion electromagnetic current with one leg off-mass-shell and the other leg on-mass-shell, using an exactly solvable manifestly covariant model of a $(3+1)$ dimensional fermion field theory. The model provides a 3D imaging of the two off-shell pion form factors $F_1$ and $F_2$ as a function of $(Q^2,t)$, which are related to each other satisfying the Ward-Takahashi identity. The normalization of the renormalized charge form factor $F_1$ is fixed by $F_1(Q^2=0, t=m^2_\pi)=1$ while the other form factor $F_2$ vanishes, i.e. $F_2(Q^2, t=m^2_\pi)=0$ for any value of $Q^2$ due to the time-reversal invariance of the strong interaction. We define the new form factor $g(Q^2,t)=F_2(Q^2,t)/(t-m^2_\pi)$ and find that $g(Q^2,t)$ can be measurable in the on-mass-shell limit. In particular, $g(Q^2=0, t=m^2_\pi)$ is related with the pion charge radius. We also compare our form factors with the data extracted from the pion electroproduction reaction for both the off-shell region ($t, Comment: typo corrected; revision for the discussion in Sec. III.; 11pages, 10 figures; version to appear in Physical Review D

The ratios of the baryon electric (GE) to magnetic (GM) form factors, GE/GM, can provide us with important information on the structure of baryons in vacuum as demonstrated in recent studies for the proton and neutron systems. It has been argued that the corresponding in-medium ratios GE*/GM* can also provide useful information on the electromagnetic structure of baryons in a nuclear medium. Although the ratios may not be measured directly in experiments except for the proton at present, the double ratios (GE*/GM*)/(GE/GM) can be directly related to the polarization-transfer measurements of bound baryons. In the present work we estimate, for the first time, the double ratios (GE*/GM*)/(GE/GM) for all the members of octet baryons in symmetric nuclear matter in the range Q2=0–3 GeV2, where Q2=−q2 with q being the four-momentum transfer.

Iron (Fe) toxicity is often observed in lowland rice (Oryza sativa L.) plants, disrupting cell homeostasis and impairing growth and crop yields. Silicon (Si) can mitigate the effects of Fe excess on rice by decreasing tissue Fe concentrations, but no information exists whether Si could prevent the harmful effects of Fe toxicity on the photosynthesis and carbon metabolism. Two rice cultivars with contrasting abilities to tolerate Fe excess were hydroponically grown under two Fe levels (25 μM or 5 mM) and amended or not with Si (0 or 2 mM). Fe toxicity caused decreases in net photosynthetic rate (A), particularly in the sensitive cultivar. These decreases were correlated with reductions in stomatal (gs) and mesophyll (gm) conductances, as well as with increasing photorespiration. Photochemical (e.g. electron transport rate) and biochemical (e.g., maximum RuBisCO carboxylation capacity and RuBisCO activity) parameters of photosynthesis, and activities of a range of carbon metabolism enzymes, were minimally, if at all, affected by the treatments. Si attenuated the decreases in A by presumably reducing the Fe content. In fact, A as well as gs and gm, correlated significantly with leaf Fe contents. In summary, our data suggest a remarkable metabolic homeostasis under Fe toxicity, and that Si attenuated the impairments of Fe excess on the photosynthetic apparatus by affecting the leaf diffusive conductance with minimal impacts on carbon metabolism.

We present time-resolved Kerr rotation measurements, showing spin lifetimes of over 100 ns at room temperature in monolayer MoSe

This study evaluated whether by-products from industrial processing of acerola (Malpighia glabra L.; AB) and guava (Psidium guajava L.; GB) fruit may stimulate the growth and metabolism of probiotic Lactobacillus and Bifidobacterium and induce changes in human colonic microbiota.The ability of non-digested and digested AB or GB to stimulate the growth ad metabolism of Lactobacillus acidophilus LA-05, Lactobacillus casei L-26 and Bifidobacterium animalis subsp. lactis BB-12 was evaluated. Changes in populations of distinct bacterial groups of human colonic microbiota induced by digested AB and GB were evaluated using an in vitro colonic fermentation system. Non-digested and digested AB and GB favoured probiotic growth. No difference among counts of probiotics in media with glucose, fructooligosaccharides and non-digested and digested AB and GB was found during a 48-h cultivation. Cultivation of probiotics in media with non-digested and digested AB and GB resulted in decreased pH, increased organic acid production and sugar consumption over time. Digested AB and GB caused overall beneficial changes in abundance of Bifidobacterium spp., Lactobacillus-Enterococcus, Eubacterium rectall-Clostridium coccoides and Bacteroides-Provotella populations, besides to decrease the pH and increase the short-chain fatty acid production during a 24-h in vitro colonic fermentation.AB and GB could be novel prebiotic ingredients because they can stimulate the growth and metabolism of probiotics and induce overall beneficial changes in human colonic microbiota.AB and GB stimulated the growth and metabolism of probiotics, in addition to induce beneficial alterations in human colonic microbiota composition and increase short-chain fatty acid production. These results characterize AB and GB as potential prebiotic ingredients and fruit processing by-products as sources of added-value compounds.

Pion valence distributions in nuclear medium and vacuum are studied in a light-front constituent quark model. The in-medium input for studying the pion properties is calculated by the quark-meson coupling model. We find that the in-medium pion valence distribution, as well as the in-medium pion valence wave function, are substantially modified at normal nuclear matter density, due to the reduction in the pion decay constant., Comment: 16 pages. 10 eps figures, typos corrected. Version to appear Physics Letters B

The pion structure in Minkowski space is described in terms of an analytic model of the Bethe–Salpeter amplitude combined with Euclidean Lattice QCD results. The model is physically motivated to take into account the running quark mass, which is fitted to Lattice QCD data. The pion pseudoscalar vertex is associated to the quark mass function, as dictated by dynamical chiral symmetry breaking requirements in the limit of vanishing current quark mass. The quark propagator is analyzed in terms of a spectral representation, and it shows a violation of the positivity constraints. The integral representation of the pion Bethe–Salpeter amplitude is also built. The pion space-like electromagnetic form factor is calculated with a quark electromagnetic current, which satisfies the Ward–Takahashi identity to ensure current conservation. The results for the form factor and weak decay constant are found to be consistent with the experimental data.

A comprehensive solid state study of Paroxetine nitrate hydrate, (PRX+·NO3−)H2O, is reported. This salt was characterized by a combination of methods, including Single crystal X-ray diffraction, Thermal analysis, Fourier transform infrared spectroscopy (FTIR) and Solubility measurements. (PRX+·NO3−)H2O crystallizes in the monoclinic C2 space group (Z′ = 1) and its packing was analyzed in details, showing that the main supramolecular motif consists in a C 2 2 ( 4 ) chain formed by charge-assisted N+-H⋯O− hydrogen bonds. The salt formation and conformation features were also accuracy established via FTIR spectra. In comparison with the pharmaceutical approved (PRX+⋅Cl−)⋅0.5H2O, (PRX+⋅NO3−)⋅H2O showed a decrease of 24 °C in the drug melting peak and a slight reduction in its water solubility value.

Buclizine (BCZ) is a chiral synthetic piperazine derivative which has antihistaminic, anti-muscarinic and antiemetic properties, and has been reintroduced as an appetite stimulant, especially for pediatric patients. Structural information about this drug, as well as other buclizine crystalline forms (solvates, salts and co-crystals) including the BCZ free-base (BCZ-FB), is non-existent. Here, we present for the first time the crystal structure of the monohydrochloride monohydrate salt of BCZ (BCZHCl·H2O), and of its anhydrous form, BCZHCl. Interestingly, BCZHCl·H2O was obtained by recrystallization from the raw material (BCZH2Cl2) in ethanol:water solution showing that BCZ anhydrous dihydrochloride salt changes easily to a monohydrochloride monohydrate salt modification, which raise concerns about formulation quality control. BCZHCl·H2O and BCZHCl crystallize in the orthorhombic space groups (Pna21 and Pca21) belonging to the mm2 point group and are thus classified as non-centrosymmetric achiral structures (NA). Intuitively, we expect these salts to crystallize in a space group with a center of symmetry, since less than 5% of the known racemic compounds crystallize in the NA type. The crystal structures of BCZH2Cl2 and BCZ-FB were not determined, but their existence was verified by other techniques (chloride ion analysis, PXRD, HPLC, FT-IR, DSC, TGA) and by comparison of the obtained results with those found for BCZHCl. Additionally, we have also performed an evaluation of the equilibrium solubility (at six different aqueous media) and the dissolution profile of the BCZHCl salt compared to the raw material and BCZ-FB. Different equilibrium solubility values were found comparing the three forms in acidic and neutral pH ranges and all of them were insoluble at pH > 7.0. Moreover, tablets prepared with BCZH2Cl2, BCZHCl or BCZ-FB show significant differences in terms of dissolution profile.

Essential roles in biological systems depend on protein-ligand recognition, which is mostly driven by specific non-covalent interactions. Consequently, investigating these interactions contributes to understanding how molecular recognition occurs. Nowadays, a large-scale data set of protein-ligand complexes is available in the Protein Data Bank, what led several tools to be proposed as an effort to elucidate protein-ligand interactions. Nonetheless, there is not an all-in-one tool that couples large-scale statistical, visual, and interactive analysis of conserved protein-ligand interactions. Therefore, we propose nAPOLI (Analysis of PrOtein-Ligand Interactions), a web server that combines large-scale analysis of conserved interactions in protein-ligand complexes at the atomic-level, interactive visual representations, and comprehensive reports of the interacting residues/atoms to detect and explore conserved non-covalent interactions. We demonstrate the potential of nAPOLI in detecting important conserved interacting residues through four case studies: two involving a human cyclin-dependent kinase 2 (CDK2), one related to ricin, and other to the human nuclear receptor subfamily 3 (hNR3). nAPOLI proved to be suitable to identify conserved interactions according to literature, as well as highlight additional interactions. Finally, we illustrate, with a virtual screening ligand selection, how nAPOLI can be widely applied in structural biology and drug design. nAPOLI is freely available at bioinfo.dcc.ufmg.br/napoli/ .

With the use of genetic engineering, modified and sometimes more efficient enzymes can be created for different purposes, including industrial applications. However, building modified enzymes depends on several in vitro experiments, which may result in the process being expensive and time-consuming. Therefore, computational approaches could reduce costs and accelerate the discovery of new technological products. In this study, we present a method, called structural signature variation (SSV), to propose mutations for improving enzymes&rsquo, activity. SSV uses the structural signature variation between target enzymes and template enzymes (obtained from the literature) to determine if randomly suggested mutations may provide some benefit for an enzyme, such as improvement of catalytic activity, half-life, and thermostability, or resistance to inhibition. To evaluate SSV, we carried out a case study that suggested mutations in &beta, glucosidases: Essential enzymes used in biofuel production that suffer inhibition by their product. We collected 27 mutations described in the literature, and manually classified them as beneficial or not. SSV was able to classify the mutations with values of 0.89 and 0.92 for precision and specificity, respectively. Then, we used SSV to propose mutations for Bgl1B, a low-performance &beta, glucosidase. We detected 15 mutations that could be beneficial. Three of these mutations (H228C, H228T, and H228V) have been related in the literature to the mechanism of glucose tolerance and stimulation in GH1 &beta, glucosidase. Hence, SSV was capable of detecting promising mutations, already validated by in vitro experiments, that improved the inhibition resistance of a &beta, glucosidase and, consequently, its catalytic activity. SSV might be useful for the engineering of enzymes used in biofuel production or other industrial applications.

Structural signature is a set of characteristics that unequivocally identifies protein folding and the nature of interactions with other proteins or binding compounds. We investigate the use of the geometric linearity of the main chain as a key feature for structural classification. Using polypeptide main chain atoms as structural signature, we showed that this signature is better to preciselly classify than using C\(\alpha \) only. Our results are equivalent in precision to a structural signature built including artificial points between C\(\alpha \)s and hence we believe this improvement in classification precision occurs due to the strengthening of geometric linearity.

Introduction Residual excessive sleepiness (RES) is presented by 6% of obstructive sleep apnea patients despite effective CPAP therapy. Few interventions have been tested for this condition and are focused on daytime stimulants. Recently, cholinergic activity decline was suggested as a potential mechanism in the pathophysiology of RES. This study aimed to investigate the effects of donepezil, an anticholinesterase inhibitor, in patients with RES. Methods This double-blind, randomized, placebo-controlled crossover study included participants with RES (35-65 years). Neuropsychiatric disorders, alcoholism, smoking, shiftwork, psychoactive drugs, other sleep disorders were exclusion criteria. Participants were assigned to one intervention arm (donepezil 5 mg for 15 days followed by donepezil 10mg for 15 days or placebo in the morning). After a 20-day wash-out, the same procedure was repeated following the crossover design. Somnolence measured by the Epworth sleepiness scale (ESS) and Maintenance of Wakefulness Test (MWT) were the primary endpoints. PSG, cognitive (trail test, continuous performance test) and Beck’s depression scale parameters were secondary endpoints. General Linear Models for repeated measures compared interventions responses. Cohen’s d measured effect sizes. Adverse events (AEs) were assessed by questionnaire. Results The study enrolled eight individuals. ESS was lower in the donepezil arm than in the placebo arm (8.9±4.4 vs 15.7±4.1, p Conclusion Donepezil improved subjective sleepiness in individuals with RES. To our knowledge, this is the first study to report the effects of a cholinergic intervention in patients with RES. Effect size was high for self-reported sleepiness, which may impact on quality of life and risk of disability in people with RES. Agents acting on the cholinergic system are potential targets for treating RES. Support Acknowledgements Brazilian National Council for Scientific and Technological Development (CNPq) This study is supported by AFIP (Associacao Fundo Incentivo a Pesquisa).

In this paper, we report the development of a novel technique in which the magnetoresistance of nanostructures is perturbatively measured by transversally modulating the DC magnetic field. It measures the electrical transport counterpart of the transverse magnetic AC-susceptibility. The technique was developed in a conventional four-probe configuration in which a small DC current flows through the sample and a small transverse AC-field perturbates the equilibrium position of the sample magnetization. Lock-in detection, in-phase with the AC-perturbation, is used to measure the voltage signal between the two inner electrodes of the four-probe station. We successfully demonstrated that this signal is proportional to the product of the first derivative of sample resistance with respect to the equilibrium position of the magnetization times the second derivative of the energy with respect to the equilibrium position of the magnetization. These dependences add new features to the technique investigated here that were not captured by the investigations previously reported on the same subject. To show the effective use of the technique, we discuss its application in measuring magnetic properties of thin magnetic films in the non-saturated regime.

Summary: Obesity has been associated with cognitive decline, atrophy of brain regions related to learning and memory, and higher risk of developing dementia. However, the molecular mechanisms underlying these neurological alterations are still largely unknown. Here, we investigate the effects of palmitate, a saturated fatty acid present at high amounts in fat-rich diets, in the brain. Palmitate is increased in the cerebrospinal fluid (CSF) of overweight and obese patients with amnestic mild cognitive impairment. In mice, intracerebroventricular infusion of palmitate impairs synaptic plasticity and memory. Palmitate induces astroglial and microglial activation in the mouse hippocampus, and its deleterious impact is mediated by microglia-derived tumor necrosis factor alpha (TNF-α) signaling. Our results establish that obesity is associated with increases in CSF palmitate. By defining a pro-inflammatory mechanism by which abnormal levels of palmitate in the brain impair memory, the results further suggest that anti-inflammatory strategies may attenuate memory impairment in obesity. : Obesity has been associated with cognitive decline. Melo et al. show that palmitate levels are increased in the CSF of overweight and obese humans. In mice, intracerebroventricular infusion of palmitate impairs synaptic plasticity and memory. Microglial-derived TNF-α mediates the deleterious actions of palmitate in the brain. Keywords: palmitate, memory impairment, obesity, brain inflammation, microglia, TNF-α, insulin signaling

Several computational activities, such as image segmentation and classification, use texture information. This information, also called descriptors, is typically calculated through the Gray Level Occurrence Matrix (GLCM), which has a quadratic cost. In this work, we discuss an alternative to this method using Sum and Difference Histograms (SDH), which has linear cost. A set of nine equations that already exist in the literature, but presenting high values of difference with GLCM, were investigated and adapted in this study. The differences (which in some cases were very high) were eliminated in most of the descriptors. The few remaining differences present values very close to zero, with a ratio of 10−1. In addition, six other equations are proposed and discussed in this study. To validate these equations, a series of experiments are performed, using real and synthetic textures. Each texture contains different combinations that represent the same motif with different perspectives and scales. These served to validate the equations proposed in this study. Moreover, in applications always present the same pattern of behavior for the equivalent equations of the original ones described by using GLCM. All the results were favorable to the use of SDH that presented a reduction of the complexity wich speeds up to 98.6% the computational time.

Leishmaniasis is an endemic disease caused by protozoa of the genus Leishmania, which affects around two million people worldwide. One major drawback in the treatment of leishmaniasis is the emergence of resistance to current chemotherapeutics. Medicinal and aromatic plants constitute a major source of natural organic compounds. In this study, the leaf essential oil of Cryptocarya aschersoniana was obtained by hydrodistillation in a Clevenger-type apparatus, and the chemical composition was analyzed by GC-MS and GC-FID. The essential oil of these species was predominantly constituted by monoterpene hydrocarbons (48.8%). Limonene (42.3%), linalool (9.7%) and nerolidol (8.6%) were the main constituents in the oil of C. aschersoniana. The in vitro activity of the oil was evaluated against the promastigote forms of Leishmania amazonensis, the causative agent of cutaneous leishmaniasis in humans. The essential oil of C. aschersoniana showed high activity against L. amazonensis promastigote forms (IC50 = 4.46 µg/mL), however, it also demonstrated a relatively high cytotoxicity on mouse peritoneal macrophages (CC50 = 7.71 µg/mL). This is the first report of the chemical composition and the leishmanicidal and cytotoxic activities of the leaf essential oil of C. aschersoniana.

exico D.F. 07738, M´ exico In this work a two-step procedure is reported for the formation of ZnO/porous silicon (PS) composites in which ZnO is embedded in the pores of sponge like mesoporous silicon. The procedure consists of an isothermal annealing of the PS layer in Zn vapors using a close space configuration and a subsequent oxidation of the Zn infiltrated in the pores. The oxidation agent and the annealing duration are optimized for a complete oxidation of the infiltrated Zn. Structure, morphology and composition of the samples were characterizedbyX-raydiffraction(XRD),extendedX-rayabsorptionfinestructure(EXAFS),ScanningElectronMicroscopy(SEM), Energy Dispersive Spectroscopy (EDS), Rutherford backscattering spectrometry (RBS) and photoluminescence (PL). The ZnO/PS composite was observed to exhibit a broad luminescent band covering almost all the visible range.