Early Postoperative Results in Robotic-Arm-Assisted Total Knee Replacement versus Conventional Technique: First Latin American Experience.

Early results with robotic-arm-assisted total knee arthroplasty (TKA) are encouraging; nevertheless, literature might be unrepresentative, as it comes mostly from American, European, and Asian countries. There is limited experience and no comparative clinical reports in Latin America, a region of mainly low- and middle-income countries with limited access to these promising technologies. This study aims to compare the early postoperative results of the first Latin American experience with robotic-arm-assisted TKA versus conventional TKA. A cohort study was performed, including 181 consecutive patients (195 knees) with advanced symptomatic knee osteoarthritis (OA) undergoing primary TKA between March 2016 and October 2019. The cohort included 111 consecutive patients (123 knees) undergoing conventional TKA, followed by 70 consecutive patients (72 knees) undergoing robotic-arm-assisted TKA. The same surgical team (surgeon 1 and surgeon 2) performed all procedures. Patients with previous osteotomy, posttraumatic OA, and revision components were not considered. The same anesthetic and rehabilitation protocol was followed. The investigated clinical outcomes (for the first 60 postoperative days) were: surgical tourniquet time, time to home discharge, time to ambulation, postoperative daily pain (Visual Analog Scale), opioid use, range of motion, blood loss, complications, and postoperative mechanical axis. The early clinical postoperative results of this first Latin American comparative experience of robotic-arm-assisted TKA versus conventional technique showed lower opioids requirements and faster functional recovery of ambulation in those patients operated with the robotic system; nevertheless, surgical times were higher, without differences in total postoperative complications and other clinical outcomes.

Morphology, dynamic disorder, and charge transport in an indoloindole-based hole-transporting material from a multi-level theoretical approach.

The exponential effort in the design of hole-transporting materials (HTMs) during the last decade has been motivated by their key role as p-type semiconductors for (opto)electronics. Although structure-property relationships have been successfully rationalized to decipher optimal site substitutions, aliphatic chain lengths or efficient aromatic cores for enhanced charge conduction, the impact of molecular shape, material morphology and dynamic disorder has been generally overlooked. In this work, we characterize by means of a multi-level theoretical approach the charge transport properties of a novel planar small-molecule HTM based on the indoloindole aromatic core (IDIDF), and compare it with spherical spiro-OMeTAD. Hybrid DFT calculations predict moderate band dispersions in IDIDF associated to the main transport direction characterized by π-π stacked molecules, both between the indoloindole cores and the thiophene groups. Strongly coupled dimers show relevant non-covalent interactions (NCI), indicating that NCI surfaces are a necessary but not exclusive requirement for large electronic couplings. We evidence remarkable differences in the site energy standard deviation and electronic coupling distributions between the conduction paths of IDIDF and spiro-OMeTAD. Despite the spherical vs. planar shape, theoretical calculations predict in the static crystal strong direction-dependent charge transport in the two HTMs, with ca. one-order-of-magnitude higher mobility (µ) for IDIDF. The dynamical disorder promoted by finite temperature effects in the crystal leads to a reduction in the hole transport properties in both HTMs, with maximum µ values of 2.42 and 4.2 × 10-2 cm2 V-1 s-1 for IDIDF and spiro-OMeTAD, respectively, as well as a significant increase in the transport anisotropy in the latter. Finally, the impact of the material amorphousness in the hole mobility is analysed by modelling a fully random distribution of HTM molecules. An average (lower-bound) mobility of 1.1 × 10-3 and 4.9 × 10-5 cm2 V-1 s-1 is predicted for planar IDIDF and spherical spiro-OMeTAD, respectively, in good accord with the experimental data registered in thin-film devices. Our results demonstrate the strong influence of molecular shape, dynamic structural fluctuations and crystal morphology on the charge transport, and pose indoloindole-based HTMs as promising materials for organic electronics and photovoltaics.

Relativistic Density Functional NMR Tensors Analyzed with Spin-free Localized Molecular Orbitals.

The front cover artwork is provided by Dr. Alberto Fernández-Alarcón. The image symbolizes the interactions of a molecule, via its orbitals, with an electromagnetic field, to produce the spectroscopic signals observed in NMR. Read the full text of the Concept at 10.1002/cphc.202200667.

Relativistic Density Functional NMR Tensors Analyzed with Spin-free Localized Molecular Orbitals.

The implementation of fast relativistic methods based on density functional theory, in conjunction with localized molecular orbital (LMO) based analysis, allows straightforward interpretations of NMR parameters in terms of contributions from core shells, lone pairs, and bonds, for compounds containing elements from across the periodic table. We present a conceptual review of a frequently used LMO analysis of NMR parameters calculated in the presence of spin-orbit interactions and other relativistic effects. An accompanying example focuses on the 15 N shielding in a heavy metal complex.

La artroplastía total bilateral de rodilla en un acto anestésico. Un procedimiento seguro, comparable a la artroplastía de rodilla unilateral / Bilateral total knee arthroplasty is a safe procedure compared to unilateral total knee arthroplasty

Introducción: El objetivo de este trabajo es comparar los resultados clínicos y complicaciones de la artroplastia total de rodilla bilateral (ATRB) con los de la artroplastia total de rodilla unilateral (ATRU).Materiales y métodos: estudio caso control. Se analizaron quince pacientes (treinta rodillas) con ATRB y ciento dos con ATRU, operados entre marzo del 2016 a agosto del 2018 por un mismo equipo quirúrgico, centro y modelo de prótesis. Se excluyeron artroplastias con componentes constreñidos. Se analizaron los datos demográficos, estadía hospitalaria (EH), caída del hematocrito, necesidad de transfusión sanguínea, días con drenaje, complicaciones postoperatorias, mortalidad, tiempo de isquemia y rango de movilidad (ROM). Se utilizó la encuesta KOOS Jr. para medir resultados funcionales y otra para valorar satisfacción. El análisis estadístico se realizó con t de Student, prueba exacta de Fisher y modelos mixtos (p <0.05).Resultados: ambos grupos fueron comparables en edad, IMC, tabaquismo, riesgo anestésico según la Sociedad Americana de Anestesiología (ASA), depresión y hematocrito. El grupo ATRB presentó una EH, días de drenaje, descenso del hematocrito postoperatorio y necesidad de transfusiones significativamente mayor. No hubo diferencias significativas en cuanto a tiempo de isquemia, complicaciones postoperatorias, mortalidad y en el ROM logrado a corto y mediano plazo. Se observó una tendencia a lograr antes el ROM objetivo (0-120°) en las ATRB. No hubo diferencias significativas en los resultados funcionales ni en satisfacción. Conclusión: en nuestro centro y en pacientes seleccionados, la ATRB es un procedimiento seguro sin una mayor tasa de complicaciones ni mortalidad asociada, con resultados clínicos similares a la ATRU. Nivel de Evidencia: III

Introduction: The aim of this study is to compares the clinical results and complications of bilateral total knee arthroplasty (BTKA) with unilateral total knee arthroplasty (UTKA).Materials and methods: case control study. Fifteen patients (thirty knees) with BTKA and hundred two patients with UTKA were analyzed, operated from March 2016 to August 2018 by the same surgical team, center and prosthetic model. Arthroplasties with constrained components were excluded. Demographic data, length of hospital stay (LOS), hematocrit drop, need for blood transfusion, days with drainage, post-operative complications, mortality, tourniquet time and range of motion (ROM) were analyzed. KOOS Jr. survey was answered, and satisfaction was reported. Statistical analysis was performed with t-Student, Fisher's test and mixed models (p <0.05).Results: the groups were comparable (age, BMI, smoking, anesthetic risk according to the classification system of the American Society of Anesthesiology (ASA), depression, hematocrit). The BTKA group presented LOS, drainage days, decrease in post operative hematocrit and need for transfusions significantly higher. There were no significant differences in terms of tourniquet time, post-operative complications, mortality and ROM achieved at short term. There is a tendency to achieve the target ROM (0-120 °) earlier on the BTKA group. There were no significant differences in functional results or satisfaction.Conclusion: In our center and in selected patients, the BTKA is a safe procedure without a higher rate of complications or associated mortality, with clinical results similar to the UTKA. Level of Evidence: III

The nature of the intermolecular interaction in (H2X)2 (X = O, S, Se).

Hydrogen bonds (HBs) are crucial non-covalent interactions in chemistry. Recently, the occurrence of an HB in (H2S)2 has been reported (Arunan et al., Angew. Chem., Int. Ed., 2018, 57, 15199), challenging the textbook view of H2S dimers as mere van der Waals clusters. We herein try to shed light on the nature of the intermolecular interactions in the H2O, H2S, and H2Se dimers via correlated electronic structure calculations, Symmetry Adapted Perturbation Theory (SAPT) and Quantum Chemical Topology (QCT). Although (H2S)2 and (H2Se)2 meet some of the criteria for the occurrence of an HB, potential energy curves as well as SAPT and QCT analyses indicate that the nature of the interaction in (H2O)2 is substantially different (e.g. more anisotropic) from that in (H2S)2 and (H2Se)2. QCT reveals that the HB in (H2O)2 includes substantial covalent, dispersion and electrostatic contributions, while the last-mentioned component plays only a minor role in (H2S)2 and (H2Se)2. The major contributions to the interactions of the dimers of H2S and H2Se are covalency and dispersion as revealed by the exchange-correlation components of QCT energy partitions. The picture yielded by SAPT is somewhat different but compatible with that offered by QCT. Overall, our results indicate that neither (H2S)2 nor (H2Se)2 are hydrogen-bonded systems, showing how the nature of intermolecular contacts involving hydrogen atoms evolves in a group down the periodic table.

Antiplatelet Therapy And Percutaneous Coronary Interventions.

Dual antiplatelet therapy is one of the cornerstones of modern percutaneous coronary interventions. The development of new therapeutic agents has significantly reduced ischemic events at the risk of increased bleeding complications. Therefore, efforts are currently focused on optimizing therapeutic algorithms to obtain the greatest anti-thrombotic benefit associated with the lowest risk of bleeding, that is, the greater net clinical benefit. A significant number of trials evaluating different drug combinations or adjustments in treatment duration have been completed. However, clinical translation of these results is often difficult due to the heterogeneity of the therapeutic approaches. The aim of this manuscript is to provide an updated review of the literature regarding the use of dual antiplatelet therapy in patients undergoing coronary angioplasty and stenting.

Photochemistry in Real Space: Batho- and Hypsochromism in the Water Dimer.

Invited for the cover of this issue is Alberto Fernández-Alarcón and co-workers at The Institute of Chemistry of the National Autonomous University of Mexico and The School of Chemistry of the University of Oviedo. The image depicts the real space analysis of the excitation energies in the double blue and red shift of the water dimer. Read the full text of the article at 10.1002/chem.202002854.

Photochemistry in Real Space: Batho- and Hypsochromism in the Water Dimer.

The development of chemical intuition in photochemistry faces several difficulties that result from the inadequacy of the one-particle picture, the Born-Oppenheimer approximation, and other basic ideas used to build models. It is shown herein how real-space approaches can be efficiently used to gain valuable insights in photochemistry through a simple example of red and blue shift effects: the double hypso- and bathochromic shifts in the low-lying valence excited states of (H2 O)2 . It is demonstrated that 1) the use of these techniques allows the perturbative language used in the theory of intermolecular interactions, even in the strongly interacting short-range regime, to be maintained; 2) one and only one molecule is photoexcited in each of the addressed excited states and 3) the electrostatic interaction between the in-the-cluster molecular dipoles provides a fairly intuitive rationalisation of the observed batho- and hypsochromism. The methods exploited and illustrated herein are able to maintain the individuality and properties of the interacting entities in a molecular aggregate, and thereby they allow chemical intuition in general states, at any geometry and using a broad variety of electronic structure methods to be kept and built.

On the strength of hydrogen bonding within water clusters on the coordination limit.

Hydrogen bonds (HB) are arguably the most important noncovalent interactions in chemistry. We study herein how differences in connectivity alter the strength of HBs within water clusters of different sizes. We used for this purpose the interacting quantum atoms energy partition, which allows for the quantification of HB formation energies within a molecular cluster. We could expand our previously reported hierarchy of HB strength in these systems (Phys. Chem. Chem. Phys., 2016, 18, 19557) to include tetracoordinated monomers. Surprisingly, the HBs between tetracoordinated water molecules are not the strongest HBs despite the widespread occurrence of these motifs (e.g., in ice Ih ). The strongest HBs within H2 O clusters involve tricoordinated monomers. Nonetheless, HB tetracoordination is preferred in large water clusters because (a) it reduces HB anticooperativity associated with double HB donors and acceptors and (b) it results in a larger number of favorable interactions in the system. Finally, we also discuss (a) the importance of exchange-correlation to discriminate among the different examined types of HBs within H2 O clusters, (b) the use of the above-mentioned scale to quickly assess the relative stability of different isomers of a given water cluster, and (c) how the findings of this research can be exploited to indagate about the formation of polymorphs in crystallography. Overall, we expect that this investigation will provide valuable insights into the subtle interplay of tri- and tetracoordination in HB donors and acceptors as well as the ensuing interaction energies within H2 O clusters.

Partition of electronic excitation energies: the IQA/EOM-CCSD method.

Different developments in chemistry and emerging technologies have generated a renewed interest in the properties of molecular excited states. We present herein the partition of black-box, size-consistent equation-of-motion coupled cluster singles and doubles (EOM-CCSD) excitation energies within the framework of the interacting quantum atoms (IQA) formalism. We denote this method as IQA/EOM-CCSD. We illustrate this approach by considering small molecules used often in the study of excited states. This investigation shows how the combination of IQA and EOM-CCSD may provide valuable insights into the molecular changes induced by electron excitation via the real space distribution of the energy of an absorbed photon in a molecular system. Our results reveal (i) the most energetically deformed atomic basins and (ii) the most affected covalent and non-covalent interactions within a molecule due to a given photoexcitation. In other words, this kind of analysis provides insights into the spatial energetic redistribution accompanying an electronic excitation, with interesting foreseeable applications in the rational design of photoexcitations with tailored chemical effects. Altogether, we expect that the IQA/EOM-CCSD excitation energy partition will prove useful in the understanding of systems and processes of interest in photophysics and photochemistry.

In Planta Recapitulation of Isoprene Synthase Evolution from Ocimene Synthases.

Isoprene is the most abundant biogenic volatile hydrocarbon compound naturally emitted by plants and plays a major role in atmospheric chemistry. It has been proposed that isoprene synthases (IspS) may readily evolve from other terpene synthases, but this hypothesis has not been experimentally investigated. We isolated and functionally validated in Arabidopsis the first isoprene synthase gene, AdoIspS, from a monocotyledonous species (Arundo donax L., Poaceae). Phylogenetic reconstruction indicates that AdoIspS and dicots isoprene synthases most likely originated by parallel evolution from TPS-b monoterpene synthases. Site-directed mutagenesis demonstrated invivo the functional and evolutionary relevance of the residues considered diagnostic for IspS function. One of these positions was identified by saturating mutagenesis as a major determinant of substrate specificity in AdoIspS able to cause invivo a dramatic change in total volatile emission from hemi- to monoterpenes and supporting evolution of isoprene synthases from ocimene synthases. The mechanism responsible for IspS neofunctionalization by active site size modulation by a single amino acid mutation demonstrated in this study might be general, as the very same amino acidic position is implicated in the parallel evolution of different short-chain terpene synthases from both angiosperms and gymnosperms. Based on these results, we present a model reconciling in a unified conceptual framework the apparently contrasting patterns previously observed for isoprene synthase evolution in plants. These results indicate that parallel evolution may be driven by relatively simple biophysical constraints, and illustrate the intimate molecular evolutionary links between the structural and functional bases of traits with global relevance.

Chilling-Induced Changes in Aroma Volatile Profiles in Tomato.

Fruit and vegetables are regularly stored by consumers in the refrigerator at temperatures that may be well below the recommended storage temperatures. Apart from causing visible symptoms such as watery, sunken areas on the skin, chilling may also induce changes in fruit textural properties and flavour. The aim of this research was to investigate the effect of low temperature storage on tomato flavour and off-flavour production. To more closely mimic the real-consumer aroma perception while eating, in addition to the standard solid-phase microextraction gas chromatography-mass spectrometry (SPME/GC-MS) analysis, volatiles were also measured using a chewing device connected to a proton-transfer reaction-mass spectrometer (PTR-MS). Aroma volatiles were assessed in red ripe tomatoes of the cvs Cappricia RZ (round truss) and Amoroso RZ (cocktail truss) stored at refrigerator temperature (4 °C) and at higher temperatures (16 and 22 °C) for 20 days. The changes in aroma production were also monitored when the fruit was brought from room to refrigerator temperature and vice versa. After bringing the fruit from room to refrigerator temperature, the abundance of most volatiles was greatly reduced within 3 to 5 h, closely following the decrease in fruit temperature. When temperature was restored to room temperature following varying times of cold storage, the abundance of most volatiles increased again, but generally not to the original levels. Overall, the effects of low temperature storage on the decrease in volatile abundance were more pronounced in cv Cappricia RZ than in cv Amoroso RZ. On the contrary, the production of off flavours following prolonged cold storage was more pronounced in cv Amoroso RZ than in cv Cappricia RZ. Apart from changes in the overall abundance of the volatiles, marked changes in the volatile profile were observed in fruit stored for longer times in the cold and this may at least in part explain the negative effect of cold storage on overall tomato flavour.

Emission of volatile sesquiterpenes and monoterpenes in grapevine genotypes following Plasmopara viticola inoculation in vitro.

The grapevine (Vitis vinifera) is one of the most widely cultivated fruit crops globally, and one of its most important diseases in terms of economic losses is downy mildew, caused by Plasmopara viticola. Several wild Vitis species have been found to be resistant to this pathogen and have been used in breeding programs to introduce resistance traits to susceptible cultivars. Plant defense is based on different mechanisms, and volatile organic compounds (VOCs) play a major role in the response to insects and pathogens. Although grapevine resistance mechanisms and the production of secondary metabolites have been widely characterized in resistant genotypes, the emission of VOCs has not yet been investigated following P. viticola inoculation. A Proton Transfer Reaction-Time of Flight-Mass Spectrometer (PTR-ToF-MS) was used to analyze the VOCs emitted by in vitro-grown plants of grapevine genotypes with different levels of resistance. Downy mildew inoculation significantly increased the emission of monoterpenes and sesquiterpenes by the resistant SO4 and Kober 5BB genotypes, but not by the susceptible V. vinifera Pinot noir. Volatile terpenes were implicated in plant defense responses against pathogens, suggesting that they could play a major role in the resistance against downy mildew by direct toxicity or by inducing grapevine resistance. The grapevine genotypes differed in terms of the VOC emission pattern of both inoculated and uninoculated plants, indicating that PTR-ToF-MS could be used to screen hybrids with different levels of downy mildew resistance. Copyright © 2015 John Wiley & Sons, Ltd.