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INDUCTION: chemotherapy (IC) followed by chemoradiation (CRT) is an attractive approach in high-risk locally advanced rectal cancer. Additionally, ASA has shown potential to improve outcomes alongside CRT in rectal cancer. The ICAR trial aimed to evaluate the safety and efficacy of IC followed by CRT with or without ASA on MRI tumor response.Single-center, double-blind, randomized phase II trial to evaluate induction treatment with CAPOX, followed by capecitabine-based chemoradiotherapy with ASA (arm 1) or placebo (arm 2) in high-risk stage II-III rectal adenocarcinoma staged by MRI. The primary endpoint was MRI tumor regression grade (mrTRG). Secondary endpoints were pathological response, surgical outcomes, postoperative complications, treatment tolerance, DFS, and OS.Between January 2018 and August 2019, 27 patients were eligible, 25 (92.5%) completed IC, and 23 patients were randomly assigned (12 to ASA group; 11 to placebo group). In the ASA arm, 3 pts (25%) presented distant disease progression at restaging. Seven patients (30.4%) had cCR after neoadjuvant treatment. All 13 patients submitted to surgery after neoadjuvant treatment underwent R0 resections except for 1 patient with positive CRM, and 12 patients (92.3%) had sphincter preservation. After a median follow-up of 34.9 months, the 2-year DFS was 83.1% and 3-year OS was 81.5%.There was good compliance in both treatment arms and encouraging cCR rate. ASA during CRT was safe but failed to improve on MRI tumor response. The study was closed due to the absence of benefits.

Lately, numerous works have characterized the effectiveness of games in the process of learning. Benefits such as pleasure, stimulation, creativity, and enthusiasm have captivated people’s interest in science through interactive games. Hence, many games for teaching subjects in biochemistry have been developed. However, understanding molecular interactions in proteins can still be a difficult task for students in biochemistry classes. One of the main issues reported by them is the fact they cannot visually see an interaction that happens between proteins. More specifically, the atomic structure, the particulate nature of matter, the molecule, and the chemical interactions are considered abstract concepts by teachers and students. In this paper, we present the conception, development, and evaluation of Proteingo: a game created to build a crowdsourced database of protein-protein interactions. An experiment was conducted during the X-meeting 2016 Congress in Brazil, where 27 users played the Proteingo game. The development of the players along the plays, together with the answers of a post-test questionnaire, give substantial evidence of user’s incidental learning of chemical interactions through the Proteingo game. Also, 96.3% of the players consider the use of the game in classrooms as a didactic-pedagogical resource. Proteingo is available at http://bioinfo.dcc.ufmg.br/proteingo/ .

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

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

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.

Excess iron (Fe) is commonly observed in wetland rice (Oryza sativa L.) plants, impairing crop growth and productivity. Some information suggests that silicon (Si) can reduce Fe content in leaves and roots of rice (vegetative phase), but nothing is known if Si could mitigate the effects of Fe toxicity on rice production and photosynthesis. Here, we assessed the role of Si in alleviating the well-known effects of Fe toxicity on nutritional imbalances, biomass accumulation, photosynthesis and grain yield using two rice cultivars having differential abilities to tolerate excess Fe. Plants were hydroponically grown under two Fe levels (25 μM or 5 mM) and the nutrient solutions were amended with Si (0 or 2 mM). Under excess Fe were detected (i) nutritional deficiencies, especially of calcium and magnesium in leaves; (ii) negligible changes in grain nutritional composition, independently of Si application; (iii) decreases in net photosynthetic rates, stomatal conductance and electron transport rate, in parallel to decreased grain yield components (total grain biomass, 1000-grain mass, percentage of filled grains, number of grains per plant and harvest index), especially in the Fe-sensitive cultivar. These impairments were partially reversed by the application of Si. Results also suggest that Si alleviated the negative impacts of Fe on spikelet sterility. In summary, we conclude that the use of Si can be recommended as an effective management strategy to reduce the negative impacts of Fe toxicity on rice photosynthetic performance and crop yield.

Many studies about porphyrins have emerged in recent years, including studies using porphyrins as building blocks for supramolecular assemblies. Understanding new solid state forms of porphyrins and the elucidation of their structures can have remarkable benefits for nanoscience and synthetic biology. In this study, a new pseudopolymorph of cobalt (II) meso-tetraphenylporphyrin, (CoTPP), was synthesized in a known one-pot reaction, rather than using many-step conventional methods, was isolated and was characterized for the first time by low-temperature single crystal X-ray diffraction. It is a nonstoichiometric solvate assembled into dichloromethane channels. The most striking feature of this structure is the conformation adopted by the porphyrin macrocycle. In contrast to the non-solvated form of CoTPP that exhibits a ruffled core distortion and crystallizes in the tetragonal space group I-42d, this solvated form has been crystallized in the triclinic space group Pī and shows a distinct saddle-shaped macrocycle distortion. In the triclinic form, the conformation of one of the four phenyl rings is remarkably different from the others. A potential energy surface scan of the torsional angles around the bonds between this phenyl moiety and the macrocycle of CoTPP in both the non-solvated and the solvate forms demonstrates that the saddle-shaped macrocycle distortion depends on the unusual phenyl conformation. The distortion is responsible for the symmetry decrease in the channel solvate form, causing a loss of the 4-fold rotoinversion axis observed in the non-solvated tetragonal phase, which has identical phenyl conformations.

This work is dedicate to investigate the spin-1 electromagnetic form factors with the light-front quantum field theory approach. All prescriptions with the light-front approach are contamined by the zero-modes contribuitions to the electromagnetic matrix elements of the electromagnetic current with the plus component of the current; however, the Inna Grach prescriptions it is immune for the zero modes contribuitions. We show numerically the contribution of zero-modes for the electromagnetic current in the case of the vector particles in the light-front quantum field theory. Also the electromagnetic observables, like electromagnetic form factors, radius and the decay constant are presented.

In this work, Fe-doped and mixed ZnO nanoparticles were synthesized via a modified sol–gel method using water as unique solvent. The structural properties were analyzed by X-ray diffraction and the results showed the existence of wurtzite ZnO structure. The XRD results also indicate a phase segregation in the samples with more than 2 mol% of Fe. UV–Vis diffuse reflectance spectra showed that Fe-doped ZnO exhibited a red-shift of the band-edge and a decrease in band gap energy, as compared to pure ZnO. The surface area increased significantly with the iron addition, and TEM analysis revealed hexagonal nanoparticles.

After a brief review of B s 0 – B s 0 oscillations, we discuss the weak decays B s 0 → J / ψ ϕ and B s 0 → J / ψ f 0 ( 980 ) and the ratio R f 0 / ϕ of their decay rates in the light of recent measurements by the LHCb, D 0 and CDF Collaborations. We point out that the experimental values for R f 0 / ϕ impose tight limits on new physics contributions to both decay channels.

The issue of the contribution of zero-modes to the light-front projection of the electromagnetic current of phenomenological models of vector particles vertices is addressed in the Drell-Yan frame. Our analytical model of the Bethe-Salpeter amplitude of a spin-1 fermion-antifermion composite state gives a physically motivated light-front wave function symmetric by the exchange of the fermion and antifermion, as in the $\rho$-meson case. We found that among the four independent matrix elements of the plus component in the light-front helicity basis only the $0\to 0$ one carries zero mode contributions. Our derivation generalizes to symmetric models, important for applications, the above conclusion found for a simplified non-symmetrical form of the spin-1 Bethe-Salpeter amplitude with photon-fermion point-like coupling and also for a smeared fermion-photon vertex model., Comment: Use elservier style. 14 pages

The exponential increase in genome sequencing output has led to the accumulation of thousands of predicted genes lacking a proper functional annotation. Among this mass of hypothetical proteins, enzymes catalyzing new reactions or using novel ways to catalyze already known reactions might still wait to be identified. Here, we provide a structural and biochemical characterization of the 3-keto-5-aminohexanoate cleavage enzyme (Kce), an enzymatic activity long known as being involved in the anaerobic fermentation of lysine but whose catalytic mechanism has remained elusive so far. Although the enzyme shows the ubiquitous triose phosphate isomerase (TIM) barrel fold and a Zn2+ cation reminiscent of metal-dependent class II aldolases, our results based on a combination of x-ray snapshots and molecular modeling point to an unprecedented mechanism that proceeds through deprotonation of the 3-keto-5-aminohexanoate substrate, nucleophilic addition onto an incoming acetyl-CoA, intramolecular transfer of the CoA moiety, and final retro-Claisen reaction leading to acetoacetate and 3-aminobutyryl-CoA. This model also accounts for earlier observations showing the origin of carbon atoms in the products, as well as the absence of detection of any covalent acyl-enzyme intermediate. Kce is the first representative of a large family of prokaryotic hypothetical proteins, currently annotated as the “domain of unknown function” DUF849.

Electroweak transition form factors of heavy meson decays are important ingredients in the extraction of the Cabibbo-Kobayashi-Maskawa (CKM) matrix elements from experimental data. In this work, within a light-front framework, we calculate electroweak transition form factor for the semileptonic decay of $D$ mesons into a pion or a kaon. The model results underestimate in both cases the new data of CLEO for the larger momentum transfers accessible in the experiment. We discuss possible reasons for that in order to improve the model., Paper with 5 pages and 2 eps figures. To appear to Nuclear Physics B. Talk at Light Cone 2009: Relativistic Hadronic and Particle Physics (LC 2009), Sao Jose dos Campos, S.P, Brazil, 8-13 Jul 2009.

Investigation of the spacelike and timelike electromagnetic form factors of hadrons, within a relativistic microscopical model characterized by a small set of hypothesis, could shed light on the components of hadron states beyond the valence one. Our relativistic approach has been successfully applied first to the pion and then the extension to the nucleon has been undertaken. The pion case is shortly reviewed as an illustrative example for introducing the main ingredients of our approach, and preliminary results for the nucleon in the spacelike range $-10 (GeV/c)^2\le q^2 \le 0$ are evaluated., 8 pages, 6 figs, espcrc1.sty included. Proceedings of Fifth International Conference on Perspectives In Hadronic Physics, ICTP, May 22-26, 2006

An easy and simple synthesis of 3-aryl- trans -5,6-dihydroxy-5,6-dihydro-1,2,4-oxadiazines 4a – e from arylamidoximes 1a – e and glyoxal 2 is described.

For synthesizing title compounds, first we carried out the Ferrier's rearrangement involving tri-O-acetyl- d -glucal 1 and alcohols 2a–e using Montmorillonite K-10 as a catalyst. This reaction gave diastereoisomeric mixture of 3a–e and 4a–e . Basic hydrolysis of each pair of diastereoisomeric mixture furnished title compounds 5a–e and 6a–e , which were separated very carefully over a silica gel column yielding all diastereoisomers in the pure form. One of them 5d was subjected to a single crystal X-ray analysis to determine the correct configuration at the asymmetric carbon atom of the aglycone. The methyl signals of the diastereomers helped to assign the configuration of each diastereoisomer. Molecular orbital calculations of 5d using the semi-empirical method (AM1) has been performed to compare its results with the crystallographic data. We have also determined the rotational barrier of C(8) and O(9) bond in both (R) and (S) enantiomers of compounds 5a and 6a .

Ellipticine [5,11-dimethyl-6H-pyrido[4,3]carbazole] is a planar organic compound isolated from the plant extract of Ochrosia elliptica, with a high degree of antitumor and cytotoxic activity. Ellipticine and its derivatives have different modes of action, which may include intercalation or covalent binding to DNA and interference with the activity of topoisomerase II. In the present work we studied the electronic, geometrical and spectroscopic properties of 31 ellipticine derivatives and analogue compounds, using the semiempirical methods Parametric Method 3 and Zerner's Intermediate Neglect of Differential Overlap. The Zero Differential Overlap semiempirical Molecular Electrostatic Potential (MEP) was also calculated in order to interpret the electronic structure of the molecules. For the biologically tested ellipticines and olivacines we have observed a rule based on the dipole moment values and a selective distribution of active sites (coming from the MEP calculations) that can be used to identify the active molecules. These results provide a pattern which can be used to select potentially active molecules from the untested group of molecules and to design new ellipticine derivatives with improved antitumor activity.

The pion electromagnetic form factor is calculated in the space- and time-like regions from -10 $(GeV/c)^2$ up to 10 $(GeV/c)^2$, within a front-form model. The dressed photon vertex where a photon decays in a quark-antiquark pair is depicted generalizing the vector meson dominance ansatz, by means of the vector meson vertex functions. An important feature of our model is the description of the on-mass-shell vertex functions in the valence sector, for the pion and the vector mesons, through the front-form wave functions obtained within a realistic quark model. The theoretical results show an excellent agreement with the data in the space-like region, while in the time-like region the description is quite encouraging., 9 pages + 4 figures. To appear in Phys. Lett. B

The electromagnetic current of bound systems in the light-front is constructed in the Breit-Frame, in the limit of momentum transfer $q^+=(q^0+q^3)$ vanishing. In this limit, the pair creation term survives and it is responsible for the covariance of the current. The pair creation term is computed for the $j^+$ current of a spin one composite particle in the Breit-frame. The rotational symmetry of $j^+$ is violated if the pair term is not considered., 8 pages latex,revtex. e-mail: pacheco@axpfep1.if.usp.br and tobias@fis.ita.cta.br