New trends in nanoparticle exsolution.

Many relevant high-temperature chemical processes require the use of oxide-supported metallic nanocatalysts. The harsh conditions under which these processes operate can trigger catalyst degradation via nanoparticle sintering, carbon depositions or poisoning, among others. This primarily affects metallic nanoparticles created via deposition methods with low metal-support interaction. In this respect, nanoparticle exsolution has emerged as a promising method for fabricating oxide-supported nanocatalysts with high interaction between the metal and the oxide support. This is due to the mechanism involved in nanoparticle exsolution, which is based on the migration of metal cations in the oxide support to its surface, where they nucleate and grow as metallic nanoparticles partially embedded in the oxide. This anchorage confers high robustness against sintering or coking-related problems. For these reasons, exsolution has attracted great interest in the last few years. Multiple works have been devoted to proving the high catalytic stability of exsolved metallic nanoparticles in several applications for high-temperature energy storage and conversion. Additionally, considerable attention has been directed towards understanding the underlying mechanism of metallic nanoparticle exsolution. However, this growing field has not been limited to these types of studies and recent discoveries at the forefront of materials design have opened new research avenues. In this work, we define six new trends in nanoparticle exsolution, taking a tour through the most important advances that have been recently reported.

Microwave-Driven Exsolution of Ni Nanoparticles in A-Site Deficient Perovskites.

Exsolution has emerged as a promising method for generating metallic nanoparticles, whose robustness and stability outperform those of more conventional deposition methods, such as impregnation. In general, exsolution involves the migration of transition metal cations, typically perovskites, under reducing conditions, leading to the nucleation of well-anchored metallic nanoparticles on the oxide surface with particular properties. There is growing interest in exploring alternative methods for exsolution that do not rely on high-temperature reduction via hydrogen. For example, utilizing electrochemical potentials or plasma technologies has shown promising results in terms of faster exsolution, leading to better dispersion of nanoparticles under milder conditions. To avoid limitations in scaling up exhibited by electrochemical cells and plasma-generation devices, we proposed a method based on pulsed microwave (MW) radiation to drive the exsolution of metallic nanoparticles. Here, we demonstrate the H2-free MW-driven exsolution of Ni nanoparticles from lanthanum strontium titanates, characterizing the mechanism that provides control over nanoparticle size and dispersion and enhanced catalytic activity and stability for CO2 hydrogenation. The presented method will enable the production of metallic nanoparticles with a high potential for scalability, requiring short exposure times and low temperatures.

Dimensional Roadmap for Maximizing the Piezoelectrical Response of ZnO Nanowire-Based Transducers: Impact of Growth Method.

ZnO nanowires are excellent candidates for energy harvesters, mechanical sensors, piezotronic and piezophototronic devices. The key parameters governing the general performance of the integrated devices include the dimensions of the ZnO nanowires used, their doping level, and surface trap density. However, although the method used to grow these nanowires has a strong impact on these parameters, its influence on the performance of the devices has been neither elucidated nor optimized yet. In this paper, we implement numerical simulations based on the finite element method combining the mechanical, piezoelectric, and semiconducting characteristic of the devices to reveal the influence of the growth method of ZnO nanowires. The electrical response of vertically integrated piezoelectric nanogenerators (VING) based on ZnO nanowire arrays operating in compression mode is investigated in detail. The properties of ZnO nanowires grown by the most widely used methods are taken into account on the basis of a thorough and comprehensive analysis of the experimental data found in the literature. Our results show that the performance of VING devices should be drastically affected by growth method. Important optimization guidelines are found. In particular, the optimal nanowire radius that would lead to best device performance is deduced for each growth method.

Eficacia de una estrategia analgésica preincisional con ibuprofeno, paracetamol y dexametasona en colecistectomía laparoscópica. Estudio observacional prospectivo / Efficacy of a preincisional analgesic strategy with ibuprofen, paracetamol and dexamethasone in laparoscopic cholecystectomy. Prospective observational study

OBJETIVOS: Evaluar la eficacia y seguridad de una técnica analgésica preventiva multimodal utilizando dexametasona, ibuprofeno y paracetamol preincisionales como estrategia analgésica perioperatoria tras colecistectomía laparoscópica. METODOLOGÍA: Estudio observacional prospectivo en pacientes sometidos a colecistectomía laparoscópica bajo un protocolo anestésico común y analgesia preincisional multimodal con ibuprofeno (800 mg), paracetamol (1 g) y dexametasona (0,1 mg/kg) intravenosos e infiltración de portales de inserción de trócares con bupivacaína 0,5 %; medicación analgésica intravenosa de rescate con metamizol (2 g) y cloruro mórfico (bolus de 1 mg). Se registraron intensidades de dolor mediante escala verbal numérica y escala categórica en reposo y movimiento, necesidad y dosis de analgesia de rescate, complicaciones anestésico-quirúrgicas y grado de satisfacción en Unidad de Recuperación Postanestésica (a los 20 min, 2 h de su ingreso y al alta) y a las 24 h de la intervención. RESULTADOS: Se analizaron datos de 112 pacientes: 71 mujeres y 41 hombres, con una media de edad de 61,15 ± 16,23 años; un peso medio de 76,20 ± 12,68 kg; duración del tiempo quirúrgico (entre incisión cutánea y cierre de portales de inserción de trócares fue de 92,11 ± 30,64 min); se utilizaron dosis intraoperatorias de 1,91 ± 15,78 mcgs/kg/h de fentanilo; el estado físico se calificó como de ASA I (34,8 %), II (40,2 %), III (22,3 %) y IV (2,7 %). Se objetivaron 2 picos máximos de dolor: a los 20 min y a las 24 h de intervención, más intenso en movimiento (inspiración forzada). En 23 casos se registró la presencia de dolor agudo intenso que requirió analgesia adicional (necesidad de cloruro mórfico en 6 casos). Se documentaron 30 casos de complicaciones perioperatorias: 17 (15,18 %) pacientes refirieron náuseas y/o vómitos, 10 (8,93 %) irritabilidad venosa y 3 (2,68 %) inestabilidad hemodinámica. CONCLUSIONES: La estrategia analgésica multimodal utilizada en este estudio proporcionó una analgesia eficaz con recuperación anestésico-quirúrgica rápida y de alta calidad en la mayoría de los pacientes, con bajos requerimientos de opioides perioperatorios, en los casos en los que se precisó. Baja incidencia y gravedad de complicaciones perioperatorias, lo que facilitó tasas elevadas de cirugía ambulatoria

AIMS: To evaluate efficacy and security with a multimodal preventive analgesic technique (intravenous paracetamol, ibuprofen, dexametasone and local anesthetic infiltration incision) in postoperative pain management after laparoscopic cholecystectomy. METHODOLOGY: Observational prospective study in laparoscopic cholecystectomy under common anesthetic protocol and multimodal pre-incisional analgesia using intravenous ibuprofen (800 mg), paracetamol (1 g), dexamethasone (0.1 mg/kg) and 0.5 % bupivacaine portals infiltration. Analgesic rescue with metamizole (2 g) and morphine clorure (1 mg boluses). We noted pain grade, rescue analgesia, anesthetic-chirurgic complications and satisfaction level at five moments: in UCPA stay (20 min and 2 h after surgery and before discharge) and 24 h after surgery. RESULTS: 112 patients: 71 women and 41 men, 61.15 ± 16.23 aged; 76.20 ± 12.68 kg weight, surgery time of 92.11 ± 30.64 minutes; 1.91 ± 15,78 microgrames/kg/h fentanyl doses; ASA I (34,8 %), II (40,2 %), III (22,3 %) y IV (2,7 %). Two maximum pain peaks: at 20 min and at 24 h after the intervention and during movement. Severe pain and additional analgesia in 23 cases, and need for morphine chloride boluses in 6. Thirty cases complications were documented: emesis in 17 people (15.18 %), venous irritability in 10 cases (8.93 %) and hemodynamic instability in 3 cases (2.68 %). CONCLUSIONS: The multimodal analgesic strategy used in this study provided effective analgesia with fast, highquality anesthetic-surgical recovery in most patients. In case it was need, low perioperative opioid requirements. Low rate and severity of perioperative complications, which facilitated high outpatient surgery rates

Analysis of Production, Impact, and Scientific Collaboration on Difficult Airway Through the Web of Science and Scopus (1981-2013).

BACKGROUND: Bibliometrics, the statistical analysis of written publications, is an increasingly popular approach to the assessment of scientific activity. Bibliometrics allows researchers to assess the impact of a field, or research area, and has been used to make decisions regarding research funding. Through bibliometric analysis, we hypothesized that a bibliometric analysis of difficult airway research would demonstrate a growth in authors and articles over time. METHODS: Using the Web of Science (WoS) and Scopus databases, we conducted a search of published manuscripts on the difficult airway from January 1981 to December 2013. After removal of duplicates, we identified 2412 articles. We then analyzed the articles as a group to assess indicators of productivity, collaboration, and impact over this time period. RESULTS: We found an increase in productivity over the study period, with 37 manuscripts published between 1981 and 1990, and 1268 between 2001 and 2010 (P < .001). The difficult airway papers growth rate was bigger than that of anesthesiology research in general, with CAGR (cumulative average growth rate) since 1999 for difficult airway >9% for both WoS and Scopus, and CAGR for anesthesiology as a whole =0.64% in WoS, and =3.30% in Scopus. Furthermore, we found a positive correlation between the number of papers published per author and the number of coauthored manuscripts (P < .001). We also found an increase in the number of coauthored manuscripts, in international cooperation between institutions, and in the number of citations for each manuscript. For any author, we also identified a positive relationship between the number of citations per manuscript and the number of papers published (P < .001). CONCLUSIONS: We found a greater increase over time in the number of difficult airway manuscripts than for anesthesiology research overall. We found that collaboration between authors increases their impact, and that an increase in collaboration increases citation rates. Publishing in English and in certain journals, and collaborating with certain authors and institutions, increases the visibility of manuscripts published on this subject.

Transient bladder and fecal incontinence following epidural blood patch.

Epidural blood patch (EBP) is the currently accepted treatment of choice for postdural puncture headache because of its high initial success rates and infrequent complications. Many authors recommended a small volume (10-20 mL) of blood to be delivered for an effective EBP. Here, we report an obstetric patient who developed a transient bladder and fecal incontinence after 19 mL of blood EBP at L1 -L2 level. Since the magnetic resonance image did not demonstrate any definitive spinal cord lesion, the exact mechanism remains unclear. We suggest that accumulation of blood performed at L1 to L2 level in a closed relationship with the sacral cord, may have trigger a significant pressure elevation of the epidural space at this level, resulting in a temporal spinal cord-related injury in the sacral cord.

Quistes neuroentéricos intracerebrales en neonatos / Intracerebral neurenteric cysts in newborn infants

Introducción. Los quistes neuroentéricos intracraneales son lesiones congénitas muy poco frecuentes. Dentro del sistema nervioso, su localización más frecuente es en el raquis. Otra de las localizaciones frecuentes es en la unión craneocervical. Se han descrito pocos casos de localización supratentorial. Plantean diagnóstico diferencial con otros quistes. No es frecuente que se diagnostiquen en la edad pediátrica. La clínica que ocasionan es por efecto de masa o episodios de meningitis química. La resonancia magnética es el mejor método diagnóstico aunque, en muchas ocasiones, no se diferencian de los quistes aracnoideos. El tratamiento es quirúrgico con resección completa de las membranas para evitar las recidivas. Casos clínicos. Presentamos dos casos de lactantes que, en las últimas semanas de gestación, mostraron lesiones quísticas intracerebrales supratentoriales con aspecto de quiste aracnoideo. La resonancia magnética neonatal confirmó la existencia de dichos quistes supratentoriales con tabiques en su interior. Tras presentar un aumento del perímetro craneal se realizó el tratamiento quirúrgico con craneotomía guiada por neuronavegador y desbridamiento de los quistes. El contenido de los quistes era mucoso con gruesas membranas. El estudio anatomopatológico resultó compatible con el quiste neuroentérico. Uno de los pacientes presentó una resolución completa tras la cirugía, con buena expansión cerebral. En el segundo, persistió un quiste aracnoideo anexo, en el que fue preciso colocar una derivación cistoperitoneal, con resolución completa. Conclusiones. La mayoría de los quistes intracraneales se corresponden con quistes aracnoideos, pero existen otras lesiones quísticas que deben tratarse quirúrgicamente para su resección completa y estudio anatomopatológico (AU)

Introduction. Intracranial neurenteric cysts are very infrequent congenital lesions. Within the nervous system, they are most commonly located in the rachis. Another frequent site is the craniocervical junction. Few cases of supratentorial location have been reported. A differential diagnosis is required to distinguish them from other cysts. They are not often diagnosed in the paediatric age. The clinical features they give rise to are due to the mass effect or episodes of chemical meningitis. Magnetic resonance imaging is the best diagnostic method although on many occasions they cannot be distinguished from arachnoid cysts. Treatment consists in surgery with complete resection of the membranes in order to prevent recurrences. Case reports. We report two cases of infants who, in the last weeks of gestation, presented supratentorial intracerebral cystic lesions that resembled arachnoid cysts. A neonatal magnetic resonance scan confirmed the existence of such supratentorial cysts with septae inside them. After presenting an increase in the cranial perimeter, surgical treatment was undertaken with a neuronavigation-guided craniotomy and debridement of the cysts. The cysts contain mucus and have thick membranes. Pathological study results are consistent with a neurenteric cyst. One of the patients presented complete resolution after the intervention with good cerebral expansion. In the second case, there was persistence of an adjoining arachnoid cyst, in which placement of a cyst-peritoneal shunt was necessary with full resolution. Conclusions. Most intracranial cysts are arachnoid cysts, but there are other cystic lesions that must be treated by surgical means so that they can be completely excised and sent for pathological analyses (AU)

[Intracerebral neurenteric cysts in newborn infants]. / Quistes neuroentericos intracerebrales en neonatos.

INTRODUCTION: Intracranial neurenteric cysts are very infrequent congenital lesions. Within the nervous system, they are most commonly located in the rachis. Another frequent site is the craniocervical junction. Few cases of supratentorial location have been reported. A differential diagnosis is required to distinguish them from other cysts. They are not often diagnosed in the paediatric age. The clinical features they give rise to are due to the mass effect or episodes of chemical meningitis. Magnetic resonance imaging is the best diagnostic method although on many occasions they cannot be distinguished from arachnoid cysts. Treatment consists in surgery with complete resection of the membranes in order to prevent recurrences. CASE REPORTS: We report two cases of infants who, in the last weeks of gestation, presented supratentorial intracerebral cystic lesions that resembled arachnoid cysts. A neonatal magnetic resonance scan confirmed the existence of such supratentorial cysts with septae inside them. After presenting an increase in the cranial perimeter, surgical treatment was undertaken with a neuronavigation-guided craniotomy and debridement of the cysts. The cysts contain mucus and have thick membranes. Pathological study results are consistent with a neurenteric cyst. One of the patients presented complete resolution after the intervention with good cerebral expansion. In the second case, there was persistence of an adjoining arachnoid cyst, in which placement of a cyst-peritoneal shunt was necessary with full resolution. CONCLUSIONS: Most intracranial cysts are arachnoid cysts, but there are other cystic lesions that must be treated by surgical means so that they can be completely excised and sent for pathological analyses.