Search

AbstractBeginning in 2018, a quality improvement collaborative initiative in Brazil successfully reduced the baseline incidence density of healthcare-associated infections in intensive care settings after 2 years. We describe the adaptations of the quality improvement interventions as the COVID-19 pandemic emerged and how the pandemic affected the project outcomes. more...

We use the free radical polymerization initiator 4,4′-azobis(cyanovaleric acid) coordinated to the open metal sites of metal-organic frameworks (MOFs) to give rise to highly uniform MOF/polymer hybrids. We demonstrate this strategy on two robust zirconium MOFs (NU-1000 and MOF-808), which are the most effective catalysts for degradation of chemical warfare nerve agents. The resulting hybrid materials maintain their hydrolytic catalytic activity and have substantially improved adhesion to polypropylene and activated carbon textile fibers, yielding highly robust MOF/polymer/textile hybrid systems. These composites are suitable for the green production of active protective clothing and filters capable of detoxifying organophosphorus warfare agents. more...

Nonunion is a rare complication of metacarpal fractures and is usually associated with compound, open fractures with tissue loss and infection, or after failed surgical treatment. Repair by rigid osteosynthesis with plate and screws combined with autologous bone grafting has always been the treatment of choice for most patients. Such method allows early motion, although it has been proven that the presence of hardware may cause local soft tissue irritation. Often, hardware removal and tendon releases are necessary. We describe an original technique with a fixation method for the treatment of metacarpal nonunions, considering the excellent results attained with an intramedullary, headless screw for metacarpal fracture fixation. We report a series of three cases that evolved to bone healing with excellent clinical, functional, and radiographic outcomes. more...

Organophosphate nerve agents and pesticides are extremely toxic compounds because they result in acetylcholinesterase (AChE) inhibition and concomitant nerve system damage. Herein, we report the synthesis, structural characterization, and proof-of-concept utility of zirconium metal–organic polyhedra (Zr-MOPs) for organophosphate poisoning treatment. The results show the formation of robust tetrahedral cages [((n-butylCpZr)3(OH)3O)4L6]Cl6(Zr-MOP-1; L = benzene-1,4-dicarboxylate, n-butylCp = n-butylcyclopentadienyl, Zr-MOP-10, and L = 4,4′-biphenyldicarboxylate) decorated with lipophilic alkyl residues and possessing accessible cavities of ∼9.8 and ∼10.7 Å inner diameters, respectively. These systems are able to both capture the organophosphate model compound diisopropylfluorophosphate (DIFP) and host and release the AChE reactivator drug pralidoxime (2-PAM). The resulting 2-PAM@Zr-MOP-1(0)host–guest assemblies feature a sustained delivery of 2-PAM under simulated biological conditions, with a concomitant reactivation of DIFP-inhibited AChE. Finally, 2-PAM@Zr-MOPsystems have been incorporated into biocompatible phosphatidylcholine liposomes with the resulting assemblies being non-neurotoxic, as proven using neuroblastoma cell viability assays. more...

Overstrength factors in bridges reported in various studies show great diversity that depends on the type of bridges selected and the set of seismic records used in the analyses. Particularly in Mexico, there are no previous studies that evaluate the bridges’ overstrength. This study determines overstrength factors in medium-length reinforced concrete bridges based on dynamic nonlinear analyses to establish design parameters in bridge regulations in Mexico. More than 3000 nonlinear time history analyses were carried out using 48 bridge models subjected to seismic records from an interplate seismic source. Based on the results, the overstrength factors of simply supported bridges with spans of 30 m and 50 m and substructures composed of one or more reinforced concrete columns were determined. more...

We report the controlled synthesis of thin films of prototypical zirconium metal–organic frameworks [Zr6O4(OH)4(benzene-1,4-dicarboxylate-2-X)6] (X = H, UiO-66 and X = NH2, UiO-66-NH2) over the external surface of shaped carbonized substrates (spheres and textile fabrics) using a layer-by-layer method. The resulting composite materials contain metal–organic framework (MOF) crystals homogeneously distributed over the external surface of the porous shaped bodies, which are able to capture an organophosphate nerve agent simulant (diisopropylfluorophosphate, DIFP) in competition with moisture (very fast) and hydrolyze the P–F bond (slow). This behavior confers the composite material self-cleaning properties, which are useful for blocking secondary emission problems of classical protective equipment based on activated carbon. more...

UiO-66, MOF-808and NU-1000metal–organic frameworks exhibit a differentiated reactivity toward [Mg(OMe)2(MeOH)2]4related to their pore accessibility. Microporous UiO-66remains unchanged while mesoporous MOF-808and hierarchical micro/mesoporous NU-1000materials yield doped systems containing exposed MgZr5O2(OH)6clusters in the mesoporous cavities. This modification is responsible for a remarkable enhancement of the catalytic activity toward the hydrolytic degradation of P–F and P–S bonds of toxic nerve agents, at room temperature, in unbuffered aqueous solutions. more...

Presentamos el caso de un síndrome coronario agudo en un paciente de 30 años con trombocitemia esencial. Los síndromes coronarios agudos ocurren en el 9% de los casos en estos pacientes, y su manejo constituye todo un reto para el cardiólogo, en concreto, en cuanto a la elección del tratamiento antiagregante más adecuado y su duración, considerando que estos pacientes tienen por una parte un elevado riesgo trombótico y, además, un riesgo hemorrágico no despreciable. more...

Descrever os resultados do tratamento cirúrgico de pacientes portadores de artrogripose congênita com deformidade do punho através da osteotomia intracárpica biplanar.

Lanthanide-doped upconversion (UC) phosphors absorb low-energy infrared light and convert it into higher-energy visible light. Despite over 10 years of development, it has not been possible to synthesize nanocrystals (NCs) with UC efficiencies on a par with what can be achieved in bulk materials. To guide the design and realization of more efficient UC NCs, a better understanding is necessary of the loss pathways competing with UC. Here we study the excited-state dynamics of the workhorse UC material β-NaYF4co-doped with Yb3+and Er3+. For each of the energy levels involved in infrared-to-visible UC, we measure and model the competition between spontaneous emission, energy transfer between lanthanide ions, and other decay processes. An important quenching pathway is energy transfer to high-energy vibrations of solvent and/or ligand molecules surrounding the NCs, as evidenced by the effect of energy resonances between electronic transitions of the lanthanide ions and vibrations of the solvent molecules. We present a microscopic quantitative model for the quenching dynamics in UC NCs. It takes into account cross-relaxation at high lanthanide-doping concentration as well as Förster resonance energy transfer from lanthanide excited states to vibrational modes of molecules surrounding the UC NCs. Our model thereby provides insight in the inert-shell thickness required to prevent solvent quenching in NCs. Overall, the strongest contribution to reduced UC efficiencies in core–shell NCs comes from quenching of the near-infrared energy levels (Er3+: 4I11/2and Yb3+: 2F5/2), which is likely due to vibrational coupling to OH–defects incorporated in the NCs during synthesis. more...

La fibrilación auricular (FA) es un conocido factor de riesgo de mortalidad en diferentes patologías. Sin embargo, los datos publicados en insuficiencia cardiaca descompensada (ICD) son contradictorios. El objetivo es investigar el impacto en la mortalidad de la FA en pacientes ingresados por ICD, comparativamente con otras causas. more...

Metacarpal stress fractures, although rare in the general population, are not uncommon in high performance athletes and may be seen in individuals with chronic pain associated with sports activity and with no history of acute trauma. Stress fracture fixation in skeletal long bones with different methods and implants have been discussed in the literature, both for patients who had conservative treatment failure and prophylactically. We describe the use of intramedullary cannulated screw fixation for the treatment of a 26-year-old professional boxer who complained of hand pain and swelling with 18 months evolution. After 30 days of post-operative evolution, the patient had no pain on palpation of the metacarpal base and, after three months, he was back to boxing. This is a level V evidence study. Written informed consent was obtained from the patient for publication of this case report and accompanying images. more...

The design of upconversion phosphors with higher quantum yield requires a deeper understanding of the detailed energy transfer and upconversion processes between active ions inside the material. Rate equations can model those processes by describing the populations of the energy levels of the ions as a function of time. However, this model presents some drawbacks: energy migration is assumed to be infinitely fast, it does not determine the detailed interaction mechanism (multipolar or exchange), and it only provides the macroscopic averaged parameters of interaction. Hence, a rate equation model with the same parameters cannot correctly predict the time evolution of upconverted emission and power dependence under a wide range of concentrations of active ions. We present a model that combines information about the host material lattice, the concentration of active ions, and a microscopic rate equation system. The extent of energy migration is correctly taken into account because the energy transfer processes are described on the level of the individual ions. This model predicts the decay curves, concentration, and excitation power dependences of the emission. This detailed information can be used to predict the optimal concentration that results in the maximum upconverted emission. more...

Purpose:To study the brief and reversible mood response to acute tryptophan depletion (ATD) as a trait marker in subjects considered at risk for major depressive disorder (MDD). Procedures:ATD was administered to 64 subjects (54 European-Americans and 10 from other races) with a personal and family history of MDD. They were in remission and had been medication-free for at least 3 months. Subjects were randomly assignment to an active or sham condition in a double-blind crossover design. They were genotyped for serotonin-related candidate genes, and mood response was quantified with the Hamilton Depression Rating Scale (HDRS). Data were analyzed using Poisson regression with repeated measures and latent trajectory models. Results:Compared to the sham controls, active ATD caused modest depressive changes showing significant main effects of test condition (χ2= 5.14, d.f. = 1, p = 0.023) and time (χ2= 12.22, d.f. = 3, p = 0.007), but no significant interaction of time and test condition. Latent trajectory analysis revealed two groups, identified as depletion responders and non-responders. Those with the HTR2Ars6313 CC genotype had significantly higher HDRS scores during ATD (χ2= 11.72, d.f. = 1, p = 0.0006). Conclusions:ATD may help identifying the biological subtypes of MDD. These data are consistent with imaging reports implicating 5-HT2Areceptor function in ATD phenotypes. more...

The corticoperiosteal flap from the medial femoral condyle has become the workhorse in the management of recalcitrant nonunions with vascularized periosteum. Inclusion of the outer condylar cortex has been advocated to avoid damaging the osteogenic capacity of the periosteum and is at present an ordinary technical step in the procedure. more...

Abstract: Research on seismic safety assessment has been the centre of great interest among the scientific community in recent years. Although the devastating impact of earthquakes on current society should be incentive enough to increase research, the development of more realistic mechanical behaviour models and the continuous enhancement of computation capabilities are paramount factors contributing a great deal to the increase of such interest. In this context, three research areas can be identified as currently leading to important developments: code related research, especially in Europe where new design codes are in the implementation process; risk analysis, namely concerning the definition of methodologies for safety assessment that involve the evaluation of the failure probability and could be included in future generations of codes; and experimental characterization of constitutive laws which provides support for the development and calibration of accurate and realistic numerical models for seismic analysis and for the adequate characterization of limit state capacities. The paper will present some of the current scientific research trends on these three seismic safety assessment related topics. Studies addressing the seismic safety assessment of structures, either probabilistically or based on code provisions, and that consider realistic nonlinear mechanical behaviour models will be focussed. Reference will also be made to experimental research on the seismic behaviour of structural elements, emphasizing its crucial role to support the development of numerical models simulating the effects of different seismic strengthening techniques. Finally, given the development of studies leading to new trends and perspectives for performance based earthquake engineering, a possible scenario for seismic design in the future is presented, emphasizing the key issues for its implementation. more...