Reply to the 'Comment on "Methanol dimer formation drastically enhances hydrogen abstraction from methanol by OH at low temperature"' by D. Heard, R. Shannon, J. Gomez Martin, R. Caravan, M. Blitz, J. Plane, M. Antiñolo, M. Agundez, E. Jimenez, B. Ballesteros, A. Canosa, G. El Dib, J. Albaladejo and J. Cernicharo, Phys. Chem. Chem. Phys., 2018, 20, DOI: 10.1039/C7CP04561A.

In this Reply we answer the two main arguments raised in the Comment. The first argument is related to the binding energy of the methanol dimer and its influence on the dimerization rate constant. We show that the dimerization rate constants calculated in the Comment are unphysically low. We report values that are about two orders of magnitude higher than the values of the Comment, which confirm the conclusions of the original article that dimers can be present in a small amount. The second argument based on the dependence of the pseudo-first order rates on the methanol concentration was already explained in detail in the Supporting Information of the original article.

An automated method to find reaction mechanisms and solve the kinetics in organometallic catalysis.

A novel computational method is proposed in this work for use in discovering reaction mechanisms and solving the kinetics of transition metal-catalyzed reactions. The method does not rely on either chemical intuition or assumed a priori mechanisms, and it works in a fully automated fashion. Its core is a procedure, recently developed by one of the authors, that combines accelerated direct dynamics with an efficient geometry-based post-processing algorithm to find transition states (Martinez-Nunez, E., J. Comput. Chem.2015, 36, 222-234). In the present work, several auxiliary tools have been added to deal with the specific features of transition metal catalytic reactions. As a test case, we chose the cobalt-catalyzed hydroformylation of ethylene because of its well-established mechanism, and the fact that it has already been used in previous automated computational studies. Besides the generally accepted mechanism of Heck and Breslow, several side reactions, such as hydrogenation of the alkene, emerged from our calculations. Additionally, the calculated rate law for the hydroformylation reaction agrees reasonably well with those obtained in previous experimental and theoretical studies.

Nutrición durante el embarazo / Nutrition during the pregnancy

Durante el embarazo su organismo necesita más energía, proteínas, vitaminas y minerales que antes de la gestación. La alimentación que debe realizar tiene que aportar la energía necesaria y los alimentos nutritivos suficientes como para mantener su salud, realizar las modificaciones que experimenta su organismo, y lograr un desarrollo y crecimiento fetal óptimos. La forma más sencilla de incorporar los nutrientes que le son necesarios es realizar una alimentación equilibrada. Los alimentos que consume durante el embarazo son la base de la alimentación de su feto. Habitualmente, no es necesario que usted haga grandes cambios en su alimentación. Las costumbres alimentarías son muy personales. Pueden estar influenciadas por la familia, actitudes, creencias y preferencias por ciertos sabores, así como por la existencia o el precio de un determinado tipo de alimento. Además, le puede resultar muy difícil cambiar sus hábitos alimentarios si debe obligar al resto de la familia, si le resulta desagradable o rompe con sus costumbres. El número total de calorías y la composición de los alimentos son los factores más importantes. Una mujer con un peso normal antes del embarazo debe ganar entre 9 y 13 kilos durante la gestación. Una mujer delgada, sin embargo. Debe ganar algo más de peso; mientras que una mujer obesa debe ganar algo menos. Durante el embarazo no debe comer por dos. En general, la mujer necesita añadir solo alrededor de 200 a 300 calorías a su dieta diaria desde que comienza la gestación. Esta es una recomendación general, pero debe ser su médico quien le aconseje sobre si el número de calorías que debe consumir cada día debe ser algo mayor o menor. Así, en el caso de una adolescente, una mujer delgada o cuando el embarazo es general, se necesitan más calorías (AU)

Trajectory dynamics study of collision-induced dissociation of the Ar + CH4 reaction at hyperthermal conditions: vibrational excitation and isotope substitution.

We investigate the role of vibrational energy excitation of methane and two deuterated species (CD(4) and CH(2)D(2)) in the collision-induced dissociation (CID) process with argon at hyperthermal energies. The quasi-classical trajectory method has been applied, and the reactive Ar + CH(4) system has been modeled by using a modified version of the CH(4) potential energy surface of Duchovic et al. (J. Phys. Chem. 1984, 88, 1339) and the Ar-CH(4) intermolecular potential function obtained by Troya (J. Phys. Chem. A 2005, 109, 5814). This study clearly shows that CID is markedly enhanced with vibrational excitation and, to a lesser degree, with collision energy. In general, CID increases by exciting stretch vibrational modes of the reactant molecule. For the direct dissociation of CH(4), however, the CID cross sections appear to be essentially independent of which vibrational mode is initially excited. In all situations studied, the CID cross sections are always greater for the Ar + CD(4) reaction than for the Ar + CH(4) one, the Ar + CH(2)D(2) being an intermediate situation. A detailed analysis of the energy transfer processes, including their relation with CID, is also presented.

[Lamivudine for the treatment of patients with chronic hepatitis with negative hepatitis B AgHbe]. / Lamivudina en el tratamiento de la hepatopatía crónica por virus hepatitis B AgHbe minus.

INTRODUCTION: It is estimated that chronic hepatitis B affects to than 350 million people around the world. Patients with AgHB- minus account, in some areas, for between 50-80% of the total of the population with chronic hepatitis B. Spontaneous clearance is rare within these patients, the response to interferon is low and the probability of developing cirrhosis and hepatocarcinoma is higher than in the wild type. AIM: To analyze the response to lamivudine treatment in patients with chronic hepatitis B which are AgHB negative. RESULTS: Seven of the 9 patients which were treated in our department for more than 3 months were AgHB negative. Six of them responded to the treatment in an average time of 3.5 months (range 1-6 months). There were two patients that relapsed at 18 and 24 months and they were treated with adefovir. Four patients remained DNA negative and had normal aminotransferases values after an average treatment time of 25 months. CONCLUSION: In our series, the majority of the patients (77.7%) were AgHB negative at the beginning of treatment. The efficacy of the treatment with lamivudine in these cases is high (85.7%) and with an early response (average 3.5 months). One third of patients treated relapsed after one and a half years of treatment.

Lamivudina en el tratamiento de la hepatopatía crónica por virus hepatitis B AgHbe minus / Lamivudine for the treatment of patients with hepatitis B AGHBE Minus

Introducción: Se estima que la hepatopatía crónica por virus de la hepatitis B afecta a más de 350 millones de personas en todo el mundo. Los pacientes AgHbe minus representan en algunas áreas entre el 50-80% del total. En estos pacientes la remisión espontánea es rara, la respuesta a interferón menor y la probabilidad de evolución a cirrosis y hepatocarcinoma mayor que en la cepa salvaje. Objetivo: Analizar la respuesta al tratamiento con Lamivudina en pacientes con hepatopatía crónica VHB AgHBe negativos. Resultados: De los nueve pacientes tratados en nuestro servicio durante más de 3meses, 7 eran AgHbe negativos. De ellos 6 pacientes respondieron al tratamiento, en un tiempo medio de 3,5 meses (rango 1-6). Se han producido dos recidivas a los 18 y 24 meses que han sido tratadas con Adefovir. Cuatro pacientes persisten con ADN negativo y transaminasas normales tras un tiempo medio de tratamiento de 25 meses.Conclusiones: En nuestra serie, la mayoría de los pacientes (77,7%) eran AgHbe negativos al inicio del tratamiento. La eficacia del tratamiento con Lamivudina en ellos es alta (85,7%) y precoz (media de 3,5 meses). En un tercio de los pacientes tratados se produce recidiva viral, al menos tras 1 año y medio de tratamiento

Introduction: It is estimated that chronic hepatitis B affects to than 350 million people around the world. Patients with eAgHB- minus account, in some areas, for between 50-80% of the total of the population with chronic hepatitis B. Spontaneous clearance is rare within these patients, the response to interferon is low and the probability of developing cirrhosis and hepatocarcinoma is higher than in the wild type. Aim: To analyze the response to lamivudine treatment in patients with chronic hepatitis B which are eAgHB negative. Results: Seven of the 9 patients which were treated in our departmentfor more than 3 months were eAgHB negative. Six of them responded to the treatment in an average time of 3.5 months (range 1-6 months). There were two patients that relapsed at 18 and 24 months and they were treated withadefovir. Four patients remained DNA negative and had normal aminotransferases values after an average treatment time of 25 months. Conclusion: In our series, the majority of the patients (77.7%) were eAgHB negative at the beginning of treatment. The efficacy of the treatment with lamivudine in these cases is high (85.7%) and with an early response (average 3,5 months). One third of patients treated relapsed after one and a half years of treatment

On the conformational memory in the photodissociation of formic acid.

The photodissociation of formic acid at 248 and 193 nm was investigated by classical trajectory and RRKM calculations using an interpolated potential energy surface, iteratively constructed using the B3LYP/aug-cc-pVDZ level of calculation. Several sampling schemes in the ground electronic state were employed to explore the possibility of conformational memory in formic acid. The CO/CO2 branching ratios obtained from trajectories initiated at the cis and at the trans conformers are almost identical to each other and in very good accordance with the RRKM results. In addition, when a specific initial excitation that simulates more rigorously the internal conversion process is used, the calculated branching ratio does not vary with respect to those obtained from cis and trans initializations. This result is at odds with the idea of conformational memory in the ground state proposed recently for the interpretation of the experimental results. It was also found that the calculated CO vibrational distributions after dissociation of the parent molecule at 248 nm are in agreement with the experimental available data.

Quasiclassical trajectory study of the F + CH4 reaction dynamics on a dual-level interpolated potential energy surface.

An ab initio interpolated potential energy surface (PES) for the F + CH4 reactive system has been constructed using the interpolation method of Collins and co-workers. The ab initio calculations have been performed using second-order Möller-Plesset (MP2) perturbation theory to build the initial PES. Scaling all correlation (SAC) methodology has been employed to improve the ab initio calculations and to construct a dual-level PES. Using this PES, a detailed quasiclassical trajectory study of integral and differential cross sections, product rovibrational populations and internal energy distributions has been carried out for the F + CH4 and F + CD4 reactions and the theoretical results have been compared with the available experimental data.

Trajectory dynamics study of the Ar + CH4 dissociation reaction at high temperatures: the importance of zero-point-energy effects.

Large-scale classical trajectory calculations have been performed to study the reaction Ar + CH4--> CH3 +H + Ar in the temperature range 2500 < or = T/K < or = 4500. The potential energy surface used for ArCH4 is the sum of the nonbonding pairwise potentials of Hase and collaborators (J. Chem. Phys. 2001, 114, 535) that models the intermolecular interaction and the CH4 intramolecular potential of Duchovic et al. (J. Phys. Chem. 1984, 88, 1339), which has been modified to account for the H-H repulsion at small bending angles. The thermal rate coefficient has been calculated, and the zero-point energy (ZPE) of the CH3 product molecule has been taken into account in the analysis of the results; also, two approaches have been applied for discarding predissociative trajectories. In both cases, good agreement is observed between the experimental and trajectory results after imposing the ZPE of CH3. The energy-transfer parameters have also been obtained from trajectory calculations and compared with available values estimated from experiment using the master equation formalism; in general, the agreement is good.