Impact of Early Coherences on the Control of Ultrafast Photodissociation Reactions.

By coherent control, the yield of photodissociation reactions can be maximized, starting in a suitable superposition of vibrational states. In ultrafast processes, the interfering pathways are born from the early vibrational coherences in the ground electronic potential. We interpret their effect from a purely classical picture, in which the correlation between the initial position and momentum helps to synchronize the vibrational dynamics at the Franck-Condon window when the pulse is at its maximum intensity. In the quantum domain, we show that this localization in time and space is mediated by dynamic squeezing of the wave packet.

Two-qubit atomic gates: spatio-temporal control of Rydberg interaction.

By controlling the temporal and spatial features of light, we propose a novel protocol to prepare two-qubit entangling gates on atoms trapped at close distance, which could potentially speed up the operation of the gate from the sub-micro to the nanosecond scale. The protocol is robust to variations in the pulse areas and the position of the atoms, by virtue of the coherent properties of a dark state, which is used to drive the population through Rydberg states. From the time-domain perspective, the protocol generalizes the one proposed by Jaksch and coworkers [Jaksch et al., Phys. Rev. Lett., 2000, 85, 2208], with three pulses that operate symmetrically in time, but with different pulse areas. From the spatial-domain perspective, it uses structured light. We analyze the map of the gate fidelity, which forms rotated and distorted lattices in the solution space. Finally, we study the effect of an additional qubit to the gate performance and propose generalizations that operate with multi-pulse sequences.

Circularly polarized light-induced potentials and the demise of excited states.

In the presence of strong electric fields, the excited states of single-electron molecules and molecules with large transient dipoles become unstable because of anti-alignment, the rotation of the molecular axis perpendicular to the field vector, where bond hardening is not possible. We show how to overcome this problem by using circularly polarized electromagnetic fields. Using a full quantum description of the electronic, vibrational, and rotational degrees of freedom, we characterize the excited electronic state dressed by the field and analyze its dependence on the bond length and angle and the stability of its vibro-rotational eigenstates. Although the dynamics is metastable, most of the population remains trapped in this excited state for hundreds of femtoseconds, allowing quantum control. Contrary to what happens with linearly polarized fields, the photodissociation occurs along the initial molecular axis, not perpendicular to it.

Psychological distress in Spanish airline pilots during the aviation crisis caused by the COVID-19 pandemic and psychometric analysis of the 12-item general health questionnaire.

The aim of this study was to evaluate the psychological distress of Spanish airline pilots, a group of professionals undergoing an unprecedented work situation as a result of the Covid-19 pandemic. To do so, we administered the General Health Questionnaire-12 (GHQ-12). A total of 342 questionnaires were obtained, with the largest respondent age group being 41-50 years. The psychometric properties of the instrument were also evaluated, with an exploratory factor analysis revealing a unidimensional structure that explained 59.23% of the variance. The total score on the standard GHQ-12 was 4.54 ± 3.31 very close to the cut-off point established to determine psychological distress. The score increased among those unemployed and was also higher among pilots on furlough compared to those whose work situation was relatively normal. Furthermore, the reliability measured by the total Cronbach's alpha was above 0.8 of each across all employment status considered. These results show the desirability of conducting periodic psychological distress assessments of pilots so that effective measures can be implemented to ensure their psychological and socio-emotional well-being. Practitioner summary: This article evaluates psychological distress in a group of professionals that has received scant attention in the field. Moreover, it does so against the background of an atypical situation, evaluating the psychological distress suffered by pilots in different employment categories during the current severe crisis in the aviation sector.Abbreviations: CFI: comparative fit index; COPAC: Official College of Commercial Aviation Pilots; ECA: European Cockpit Association; EFA: exploratory factor analysis; GHQ-12: general health questionnaire-12; IATA: International Air Transport Association; KMO: Kaiser-Meyer-Olkin test; PA: optimal implementation of parallel analysis; ULS: unweighted least squares.

Anti-alignment driven dynamics in the excited states of molecules under strong fields.

We develop two novel models of the H2+ molecule and its isotopes from which we assess quantum-mechanically and semi-classically whether the molecule anti-aligns with the field in the first excited electronic state. The results from both models allow us to predict anti-alignment dynamics even for the HD+ isotope, which possesses a permanent dipole moment. The molecule dissociates at angles perpendicular to the field polarization in both the excited and the ground electronic state, as the population is exchanged through a conical intersection. The quantum mechanical dispersion of the initial state is sufficient to cause full dissociation. We conclude that the stabilization of these molecules in the excited state through bond-hardening under a strong field is highly unlikely.

Control defeasance by anti-alignment in the excited state.

We predict anti-alignment dynamics in the excited state of H2+ or related homonuclear dimers in the presence of a strong field. This effect is a general indirect outcome of the strong transition dipole and large polarizabilities typically used to control or to induce alignment in the ground state. In the excited state, however, the polarizabilities have the opposite sign compared to those in the ground state, generating a torque that aligns the molecule perpendicular to the field, deeming any laser-control strategy impossible.

[Complicated renal cyst by fistula from acute appendicitis on an appendicular mucocele. First literature report.] / Quiste renal complicado por fistulización de apendicitis aguda sobre un mucocele apendicular. Primera descripción en la literatura.

We describe the first clinical case in the reviewed literature of a patient with a complicated renal cyst by fistula of an appendicular neoplasm with acute appendicitis, as well as the management performed and the therapeutic options in similar cases.

Se describe el primer caso clínico en la literatura revisada de un paciente con un quiste renal complicado por sobreinfección tras fistulización de una neoplasia apendicular con apendicitis aguda, así como el manejo realizado y las opciones terapéuticas en un caso similar.

Quiste renal complicado por fistulización de apendicitis aguda sobre un mucocele apendicular. Primera descripción en la literatura / Complicated renal cyst by fistula from acute appendicitis on an appendicular mucocele. First literature report

Se describe el primer caso clínico en la literatura revisada de un paciente con un quiste renal complicado por sobreinfección tras fistulización de una neoplasia apendicular con apendicitis aguda, así como el manejo realizado y las opciones terapéuticas en un caso similar

We describe the first clinical case in the reviewed literature of a patient with a complicated renal cyst by fistula of an appendicular neoplasm with acute appendicitis, as well as the management performed and the therapeutic options in similar cases

Grid-Based Ehrenfest Model To Study Electron-Nuclear Processes.

The two-dimensional electron-nuclear Schrödinger equation using soft-core Coulomb potentials has been a cornerstone for modeling and predicting the behavior of one-active-electron diatomic molecules, particularly for processes where both bound and continuum states are important. The model, however, is computationally expensive to extend to more electron or nuclear coordinates. Here we propose use of the Ehrenfest approach to treat the nuclear motion, while the electronic motion is still solved by quantum propagation on a grid. In this work, we present results for a one-dimensional treatment of H2+, where the quantum and semiclassical dynamics can be directly compared, showing remarkably good agreement for a variety of situations. The advantage of the Ehrenfest approach is that it can be easily extended to treat as many nuclear degrees of freedom as needed.

Halogen-atom effect on the ultrafast photodissociation dynamics of the dihalomethanes CH2ICl and CH2BrI.

A comparative study of the ultrafast photodissociation dynamics of the dihalomethanes CH2ICl and CH2BrI has been carried out at 268 nm, around the maximum of the first absorption band, employing femtosecond velocity map ion imaging in conjunction with high level ab initio electronic structure calculations and full dimension on-the-fly trajectory calculations including surface hopping. Total translational energy distributions and angular distributions of the iodine fragments as well as reaction times for the C-I bond cleavage are presented and discussed along with the computed absorption spectra, potential energy curves and trajectories. The revealed dynamics is mainly governed by absorption to the 5A' state for CH2BrI while two dissociation pathways, through the 4A' or 5A' states, are in competition for CH2lCI. An anchor effect due to the substituent halogen atom (Br or Cl), which implies significant rotational motion of the dissociating molecule, characterizes the photodissociation in both dihalomethanes and leads to a remarkable rotational energy of the radical co-fragment. This energy flux into the internal degrees of freedom of the molecules is the main key factor governing the real time reaction dynamics.

Geometrical Optimization Approach to Isomerization: Models and Limitations.

We study laser-driven isomerization reactions through an excited electronic state using the recently developed Geometrical Optimization procedure. Our goal is to analyze whether an initial wave packet in the ground state, with optimized amplitudes and phases, can be used to enhance the yield of the reaction at faster rates, driven by a single picosecond pulse or a pair of femtosecond pulses resonant with the electronic transition. We show that the symmetry of the system imposes limitations in the optimization procedure, such that the method rediscovers the pump-dump mechanism.

Nonresonant electronic transitions induced by vibrational motion in light-induced potentials.

We find a new mechanism of electronic population inversion using strong femtosecond pulses, where the transfer is mediated by vibrational motion on a light-induced potential. The process can be achieved with a single pulse tuning its frequency to the red of the Franck-Condon window. We show the determinant role that the gradient of the transition dipole moment can play on the dynamics, and extend the method to multiphoton processes with odd number of pulses. As an example, we show how the scheme can be applied to population inversion in Na2.

Protecting and accelerating adiabatic passage with time-delayed pulse sequences.

Using numerical simulations of two-photon electronic absorption with femtosecond pulses in Na2 we show that: (i) it is possible to avoid the characteristic saturation or dumped Rabi oscillations in the yield of absorption by time-delaying the laser pulses; (ii) it is possible to accelerate the onset of adiabatic passage by using the vibrational coherence starting in a wave packet; and (iii) it is possible to prepare the initial wave packet in order to achieve full state-selective transitions with broadband pulses. The findings can be used, for instance, to achieve ultrafast adiabatic passage by light-induced potentials and understand its intrinsic robustness.

Reto diagnóstico de neoplasia de células fusiformes atípicas del cordón espermático / Diagnosis challenge of atypical spindle cells neoplasm of the spermatic cord

OBJETIVO: Describir un caso infrecuente de patología genital y revisar la literatura existente. MÉTODOS: Nuestro caso trata de un paciente de 70 años que al ser intervenido de una hernia inguinal se descubre de forma accidental una tumoración en íntima relación con el cordón espermático. RESULTADOS: Tras el análisis exhaustivo de patólogos expertos no se pudo llegar a especificar la naturaleza exacta de la tumoración extirpada en la cirugía. CONCLUSIONES: Los tumores de partes blandas del cordón espermático pueden presentarse de forma inusual y llegar a plantear un verdadero reto diagnóstico

OBJECTIVE: To report an unusual case of softtissue neoplasm and to review the literature on this type of tumour. METHODS: We report an accidentally found tumour closely related to the spermatic cord that was diagnosed in a 70 year-old man when he was being operated on for an inguinal hernia repair. RESULTS: After thorough analysis by experienced pathologists it was not possible to determine the nature of the tumour that was removed at surgery. CONCLUSIONS: Soft tissues neoplasms of the spermatic cord may occur in an unusual way and they may be a real challenge to diagnose

Long-term oncological outcomes of an active surveillance program in recurrent low grade Ta bladder cancer.

INTRODUCTION: Over the last 2 decades, there has been a major increase in active surveillance (AS) as a therapeutic alternative in urological tumors regarded to be of low risk. Owing to the findings of significant clinical outcomes in our series, this report presents an update of our AS program in patients with recurrent non-muscle-invasive bladder tumor. The objective was to confirm the oncological long-term safety of this protocol and to determine possible variables associated with progression. MATERIALS AND METHODS: Cohort of patients included in AS between 1999 and 2014. INCLUSION CRITERIA: recurrent papillary tumors, previous pTa-pT1, G1-G2, shorter than 1cm, and fewer than 5 tumour sites. EXCLUSION CRITERIA: prior G3, CIS (carcinoma in situ), or positive-result cytology. All patients underwent close monitoring with flexible cystoscopy every 3 to 4 months for the first 2 years. After this time, follow-ups were conducted every 6 months, alternating between cystoscopy and ultrasound. Urinary cytology test was performed at all visits. RESULTS: In all, 252 AS periods in 186 patients were studied, with a median follow-up of 6 years. Out of all periods, 203 (80.6%) underwent active treatment. After remaining under observation, 86.4% had not progressed in stage, and 79.3% in grade. Of these patients, 4 experienced progression to T2; all of them were previously T1G2. CONCLUSIONS: AS in a high-selectivity group of patients with recurrent non-muscle-invasive bladder tumor is feasible and oncologically safe in the long term. Patients with previous history of T1 should not be included in AS protocols even when very small recurrences are diagnosed.

State-Selective Excitation of Quantum Systems via Geometrical Optimization.

We lay out the foundations of a general method of quantum control via geometrical optimization. We apply the method to state-selective population transfer using ultrashort transform-limited pulses between manifolds of levels that may represent, e.g., state-selective transitions in molecules. Assuming that certain states can be prepared, we develop three implementations: (i) preoptimization, which implies engineering the initial state within the ground manifold or electronic state before the pulse is applied; (ii) postoptimization, which implies engineering the final state within the excited manifold or target electronic state, after the pulse; and (iii) double-time optimization, which uses both types of time-ordered manipulations. We apply the schemes to two important dynamical problems: To prepare arbitrary vibrational superposition states on the target electronic state and to select weakly coupled vibrational states. Whereas full population inversion between the electronic states only requires control at initial time in all of the ground vibrational levels, only very specific superposition states can be prepared with high fidelity by either pre- or postoptimization mechanisms. Full state-selective population inversion requires manipulating the vibrational coherences in the ground electronic state before the optical pulse is applied and in the excited electronic state afterward, but not during all times.

Ultrafast Population Inversion without the Strong Field Catch: The Parallel Transfer.

Quantum systems with sublevel structures, like molecules, prevent full population inversion from one manifold of sublevels to the other using ultrafast resonant pulses. We explain the mechanism by which this population transfer is blocked. We then develop a novel concept of geometric control, assuming full or partial coherent manipulation within the manifolds, and show that by preparing specific coherent superpositions in the initial manifold, full population inversion or full population blockade, that is, laser transparency, can be achieved. By properly choosing the relative phases of the initial state, one can interfere in the stimulated emission process, changing the pattern of Rabi oscillations so that full population inversion to the excited electronic state can be achieved almost regardless of the pulse intensity after a minimal threshold value. This is the basis of a novel control mechanism, termed parallel transfer.

Communication: Vibrational and vibronic coherences in the two dimensional spectroscopy of coupled electron-nuclear motion.

We theoretically investigate the photon-echo spectroscopy of coupled electron-nuclear quantum dynamics. Two situations are treated. In the first case, the Born-Oppenheimer (adiabatic) approximation holds. It is then possible to interpret the two-dimensional (2D) spectra in terms of vibrational motion taking place in different electronic states. In particular, pure vibrational coherences which are related to oscillations in the time-dependent third-order polarization can be identified. This concept fails in the second case, where strong non-adiabatic coupling leads to the breakdown of the Born-Oppenheimer-approximation. Then, the 2D-spectra reveal a complicated vibronic structure and vibrational coherences cannot be disentangled from the electronic motion.

"Stirred, Not Shaken": Vibrational Coherence Can Speed Up Electronic Absorption.

We have recently proposed a laser control scheme for ultrafast absorption in multilevel systems by parallel transfer (J. Phys. Chem. Lett. 2015, 6, 1724). In this work we develop an analytical model that better takes into account the main features of electronic absorption in molecules. We show that the initial vibrational coherence in the ground electronic state can be used to greatly enhance the rate and yield of absorption when ultrashort pulses are used, provided that the phases of the coherences are taken into account. On the contrary, the initial coherence plays no role in the opposite limit, when a single long pulse drives the optical transition. The theory is tested by numerical simulations in the first absorption band of Na2.

Strong field laser control of photochemistry.

Strong ultrashort laser pulses have opened new avenues for the manipulation of photochemical processes like photoisomerization or photodissociation. The presence of light intense enough to reshape the potential energy surfaces may steer the dynamics of both electrons and nuclei in new directions. A controlled laser pulse, precisely defined in terms of spectrum, time and intensity, is the essential tool in this type of approach to control chemical dynamics at a microscopic level. In this Perspective we examine the current strategies developed to achieve control of chemical processes with strong laser fields, as well as recent experimental advances that demonstrate that properties like the molecular absorption spectrum, the state lifetimes, the quantum yields and the velocity distributions in photodissociation processes can be controlled by the introduction of carefully designed strong laser fields.