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Controlled splitting of liquid droplets is a key function in many microfluidic applications. In recent years, various methodologies have been used to accomplish this task. Here, we present an optofluidic technique based on an engineered surface formed by coating a z-cut iron-doped lithium niobate crystal with a lubricant-infused layer, which provides a very slippery surface. Illuminating the crystal with a light spot induces surface charges of opposite signs on the two crystal faces because of the photovoltaic effect. If the light spot is sufficiently intense, millimetric water droplets placed near the illuminated spot split into two charged fragments, one fragment being trapped by the bright spot and the other moving away from it. The latter fragment does not move randomly but rather follows one of three well-defined trajectories separated by 120°, which reflect the anisotropic crystalline structure of Fe:LiNbO3. Numerical simulations explain the behavior of water droplets in the framework of the forces induced by the interplay of pyroelectric, piezoelectric, and photovoltaic effects, which originate simultaneously inside the illuminated crystal. Such a synergetic effect can provide a valuable feature in applications that require splitting and coalescence of droplets, such as chemical microreactors and biological encapsulation and screening.

We present a G0W0approach that is based on the evaluation of the linear response of the actions of the G0and W0operators. In this way we avoid sums over empty one-particle orbitals and do not have to explicitly develop the screened Coulomb interaction W0on a dedicated basis. For a given orbital, the self-energy is found by summing terms relative to a set of points in the real-space simulation cell. This permits us to easily control the ratio of the accuracy to the computational cost. A trivial parallelization strategy allows strong linear scaling up to tens of thousands of computing cores.

The Bethe–Salpeter equation (BSE) can be applied to compute from first-principles optical spectra that include the effects of screened electron–hole interactions. As input, BSE calculations require single-particle states, quasiparticle energy levels, and the screened Coulomb interaction, which are typically obtained with many-body perturbation theory, whose cost limits the scope of possible applications. This work tries to address this practical limitation, instead deriving spectral energies from Koopmans-compliant functionals and introducing a new methodology for handling the screened Coulomb interaction. The explicit calculation of the Wmatrix is bypassed via a direct minimization scheme applied on top of a maximally localized Wannier function basis. We validate and benchmark this approach by computing the low-lying excited states of the molecules in Thiel’s set and the optical absorption spectrum of a C60fullerene. The results show the same trends as quantum chemical methods and are in excellent agreement with previous simulations carried out at the time-dependent density functional theory or G0W0-BSE level. Conveniently, the new framework reduces the parameter space controlling the accuracy of the calculation, thereby simplifying the simulation of charge-neutral excitations, offering the potential to expand the applicability of first-principles spectroscopies to larger systems of applied interest.

Limited studies examined the effects of pneumoperitoneum during robot-assisted radical prostatectomy (RARP) and with AirSeal. The aim of this study was to assess the effect on hemodynamics of lower pressure pneumoperitoneum (8 mmHg) with AirSeal, during RARP in steep Trendelenburg 45°, proving how the combination of steep Trendelenburg, lower pressure pneumoperitoneum and the extreme surgeon's experience allows to safely perform RARP using a low-impact surgery.

The role of chlorine doping in CH3NH3PbI3represents an important open issue in the use of hybrid perovskites for photovoltaic applications. In particular, even if a positive role of chlorine doping on perovskite film formation and on material morphology has been demonstrated, an inherent positive effect on the electronic and photovoltaic properties cannot be excluded. Here we carried out periodic density functional theory and Car–Parrinello molecular dynamics simulations, going down to ∼1% doping, to investigate the effect of chlorine on CH3NH3PbI3. We found that such a small doping has important effects on the dynamics of the crystalline structure, both with respect to the inorganic framework and with respect to the cation libration motion. Together, we observe a dynamic spatial localization of the valence and conduction states in separated spatial material regions, which takes place in the 10–1ps time scale and which could be the key to ease of exciton dissociation and, likely, to small charge recombination in hybrid perovskites. Moreover, such localization is enhanced by chlorine doping, demonstrating an inherent positive role of chlorine doping on the electronic properties of this class of materials.

Quantum simulation methods based on electronic-structure theory are deemed unfit to cope with atomic heat transport within the Green–Kubo formalism, because quantum-mechanical energy densities and currents are inherently ill-defined at the atomic scale. We show that, although this difficulty would also affect classical simulations, thermal conductivity is indeed insensitive to such ill-definedness by virtue of a kind of gauge invariance resulting from energy extensivity and conservation. On the basis of these findings, we derive an expression for the adiabatic energy flux from density-functional theory, which allows heat transport to be simulated using ab initio equilibrium molecular dynamics. Our methodology is demonstrated by comparing its predictions to those of classical equilibrium and ab initio non-equilibrium (Müller–Plathe) simulations for a liquid-argon model, and by applying it to heavy water at ambient conditions.

Introduction We present a refinement to our original technique in MtF gender reassignment surgery. Our goal was to construct a neoclitoris, which is wet and covered with urethral neoprepuce. Since 1995 more than 300 transgender MtF patients have been operated at our institution. Our refinement has been applied to 12 cases and showed both excellent functional and cosmetic results during midterm follow-up.Patients and Methods During 2010 several sex reassignment surgeries have been performed using our new technique that includes: bilateral orchiectomy, removal of corpora cavernosa of the penis, formation of the neourethra with neomeatus, neovaginoplasty by inversion of penoscrotal skin flaps, construction of the neoclitoris with preservation of the neurovascular bundle and exterior vulva formation. The refinement consists in creating a neoclitoris embedded in urethral mucosa using urethral flaps. These flaps are in continuity with the previously spatulated urethra. The urethral plate is further incised distally in a Y fashion. The urethral flaps are sutured around the neoclitoris to form a neourethroclitoris covered by urethral neoprepuce, which resembles a real female clitoris. The neoclitoris is positioned in the anatomical position of the male suspensory ligament of the penis that is also the natural anatomical position of the female clitoris.Results With this method we are able to construct a clitoris with a normal sensitivity embedded in urethral mucosa that remains wet and hairless. It can be easily stimulated during sexual intercourse, as most of the patients reported great satisfaction and ability to reach orgasm.Discussion We want to emphasize how both the cosmetic results and functionality of the neovagina and neoclitoris are important in this type of surgery for the quality of life of our patients. We are still far from a perfect surgical solution, but we are further improving our technique and follow our aims step by step.

We present SIMPLE, a code developed to calculate optical properties of metallic and insulating extended systems using the optimal basis method originally proposed by E.L. Shirley in 1996. Two different approaches for the evaluation of the complex dielectric function are implemented: (i) the independent-particle approximation considering both interband and intraband contributions for metals and (ii) the Bethe–Salpeter equation for insulators. Since, notably, the optimal basis set is systematically improvable, accurate results can be obtained at a strongly reduced computational cost. Moreover, the simplicity of the method allows for a straightforward use of the code; improvement of the optimal basis and thus the overall precision of the simulations is simply controlled by one (for metals) or two (for insulators) input thresholds. The code is extensively tested, in terms of verification and performance, on bulk silver for metals and on bulk silicon for insulators. Program Title: SIMPLE Program Files doi: http://dx.doi.org/10.17632/99ps9dz428.1 Licensing provisions: GNU General Public License v2 Programming language: Fortran 95 External routines: Quantum ESPRESSO distribution, BLAS, LAPACK, FFTW, MPI. Nature of problem: First-principles calculations of the optical properties of metals and insulators. Solution method: Shirley's optimal basis for the complex dielectric function, at the independent-particle level for metals and by solving the Bethe–Salpeter equation for insulators. Restrictions: Norm-conserving pseudopotentials. [ABSTRACT FROM AUTHOR]