Low temperature nucleation of thermochromic VO2crystal domains in nanocolumnar porous thin films.

The low temperature formation of monoclinic VO2crystal domains in nanocolumnar vanadium/oxygen thin films prepared by magnetron sputtering at oblique angles is analyzed. The synthesis procedure involved the deposition of amorphous nanocolumnar VO1.9thin films at room temperature and its subsequent annealing at temperatures between 250 °C and 330 °C in an oxygen atmosphere. The thermochromic transition of these films was found at a temperature of 47 °C when the annealing temperature was 270 °C and 58 °C when the annealing temperature was 280 °C and 290 °C, presenting a clear drop of the optical transmittance in the infrared region of the spectrum. The significant downshift in the temperature window to obtain VO2in comparison with compact films and other strategies in literature is explained by the particular morphology of the nanocolumnar structures, which contains numerous defects along with open and embedded porosity.

Current status of precision medicine in pediatric oncology in Spain: a consensus report by the Spanish Society of Paediatric Haematology and Oncology (SEHOP).

The study analyzes the current status of personalized medicine in pediatric oncology in Spain. It gathers national data on the tumor molecular studies and genomic sequencing carried out at diagnosis and at relapse, the centers that perform these studies, the technology used and the interpretation and clinical applicability of the results. Current challenges and future directions to achieve a coordinated national personalized medicine strategy in pediatric oncology are also discussed. Next generation sequencing-based (NGS) gene panels are the technology used in the majority of centers and financial limitations are the main reason for not incorporating these studies into routine care. Nowadays, the application of precision medicine in pediatric oncology is a reality in a great number of Spanish centers. However, its implementation is uneven and lacks standardization of protocols; therefore, national coordination to overcome the inequalities is required. Collaborative work within the Personalized Medicine Group of SEHOP is an adequate framework for encouraging a step forward in the effort to move precision medicine into the national healthcare system.

Challenges in early phase clinical trials for childhood cancer during the COVID-19 pandemic: a report from the new agents group of the Spanish Society of Paediatric Haematology and Oncology (SEHOP).

PURPOSE: The COVID-19 pandemic has forced healthcare stakeholders towards challenging decisions. We analyse the impact of the pandemic on the conduct of phase I-II trials for paediatric cancer during the first month of state of alarm in Spain. METHODS: A questionnaire was sent to all five ITCC-accredited Spanish Paediatric Oncology Early Phase Clinical Trial Units, including questions about impact on staff activities, recruitment, patient care, supply of investigational products, and legal aspects. RESULTS: All units suffered personnel shortages and difficulties in enrolling patients, treatment continuity, or performing trial assessments. Monitoring activity was frequently postponed (73%), and 49% of on-going trials interrupted recruitment. Only two patients could be recruited during this period (75% reduction in the expected rate). CONCLUSIONS: The COVID-19 crisis has significantly impacted clinical research practice and access to innovation for children with cancer. Structural and functional changes are under way to better cope with the expected future restrictions.

Determinación de las características funcionales de los nódulos tiroideos mediante imágenes de medicina nuclear en pacientes que acudieron al Instituto de Investigaciones en Ciencias de la Salud - UNA, en el periodo 2016-2019 / Determination of the functional characteristics of thyroid nodules through nuclear medicine images in patients, who attended the Instituto de Investigaciones en Ciencias de la Salud - UNA, in the period 2016-2019

nuclear permiten visualizar la estructura y función de un órgano, tejido, hueso o sistema dentro del cuerpo, entre ellos la glándula tiroidea, la cual puede presentar un nódulo tiroideo y este es importante diagnosticar por su potencial malignidad. Objetivo: Determinar las características funcionales de los nódulos tiroideos en 183 pacientes que asistieron al Servicio de Medicina Nuclear del Instituto de Investigaciones en Ciencias de la Salud - UNA durante el período de noviembre del 2016 - noviembre del 2019. Metodología: Fue utilizada la gammacámara SPECT doble cabezal, siguiendo protocolo estandarizado, con administración de pertecnetato de sodio. Resultados: Se observó que la gran mayoría de los pacientes corresponden al sexo femenino 89%, así como que el 64% provienen de la capital y del departamento central; las patologías detectadas corresponden a bocio en 82%, 15% a nódulos (hipercaptantes, hipocaptantes y autónomos) y casos particulares de tiroiditis, tiroides ectópica y adenoma tóxico. La medicina nuclear está directamente involucrada tanto en el diagnóstico como en el tratamiento de la enfermedad tiroidea, por lo que se requiere una comprensión de la fisiopatología y el manejo de los trastornos de la tiroides, de manera a que las políticas de salud pública sean implementadas para el fortalecimiento de la lucha contra estas enfermedades. Conclusión: El trabajo de investigación realizado comprobó que un mayoritario porcentaje de participantes de sexo femenino (89%), con enfermedades tiroideas asistieron al IICS/UNA, y que la frecuencia de bocio entre la totalidad de pacientes que participaron de este estudio fué de 151/183 (82%), los pacientes provenían en su mayoría de hospitales de referencia del departamento Central y coinciden con la localización geográfica de los domicilios de los pacientes, quienes provenían principalmente del mismo departamento Central 118/183 (64%), no obstante también participaron del trabajo de investigación pacientes provenientes de otros departamentos del país. Palabras claves: Diagnóstico, medicina nuclear, tiroides, tecnología nuclear en salud, SPECT

Introduction: The images obtained by nuclear medicine allow to visualize the structure and function of an organ, tissue, bone or system inside the body, including the thyroid gland, which can present a thyroid nodule and this is important to diagnose for its potential malignancy. Objective: To determine the functional characteristics of the thyroid nodules were determined in 183 patients, who attended the Nuclear Medicine Service at the Instituto de Investigaciones en Ciencias de la Salud during the period of November 2016 - November 2019. Methodology: It was used the dual head SPECT gamma camera following a standardized protocol with administration of sodium pertechnetate. Result: It was observed that most of the patients corresponded to the female sex 89 %, as well as that 64% came from the capital and the central department. The pathologies detected corresponded to goiter in 82%, 15% to nodules (hypercaptant, hypocaptant and autonoms) and particular cases of thyroiditis, ectopic thyroid and toxic adenoma. Nuclear medicine is directly involved both in the diagnosis and in the treatment of thyroid disease, therefore it requires an understanding of the pathophysiology and management of thyroid disorders in order that public health policies are implemented for strengthening the fight against these diseases. Conclusion: The research carried out showed that a majority percentage of female participants (89%), with thyroid diseases attended IICS / UNA, and the frequency of goiter among all patients who participated in this study was 151/183 ( 82%), the patients mostly they came the reference hospitals in the Central department and coincide with the geographic location of the patients' homes, who tested mainly from the same Central department 118/183 (64%), also participate in the research work patients from other departments of the country. Keywords: Diagnosis, nuclear medicine, thyroid, health technology, SPECT.

Proteomic investigations into hypertension: what's new and how might it affect clinical practice?

Introduction: Hypertension is a multifactorial disease that has, thus far, proven to be a difficult target for pharmacological intervention. The application of proteomic strategies may help to identify new biomarkers for the early diagnosis and prompt treatment of hypertension, in order to control blood pressure and prevent organ damage. Areas covered: Advances in proteomics have led to the discovery of new biomarkers to help track the pathophysiological processes implicated in hypertension. These findings not only help to better understand the nature of the disease, but will also contribute to the clinical needs for a timely diagnosis and more precise treatment. In this review, we provide an overview of new biomarkers identified in hypertension through the application of proteomic techniques, and we also discuss the difficulties and challenges in identifying biomarkers in this clinical setting. We performed a literature search in PubMed with the key words 'hypertension' and 'proteomics', and focused specifically on the most recent literature on the utility of proteomics in hypertension research. Expert opinion: There have been several promising biomarkers of hypertension identified by proteomics, but too few have been introduced to the clinic. Thus, further investigations in larger cohorts are necessary to test the feasibility of this strategy for patients. Also, this emerging field would profit from more collaboration between clinicians and researchers.

Improving the quality of care in the molecular era for children and adolescents with medulloblastoma.

PURPOSE: Elevated mortality and morbidity rates persist in pediatric patients with medulloblastoma. We present a clinical audit of a real-world cohort of patients in search for pragmatic measures to improve their management and outcome. METHODS/PATIENTS: All pediatric patients with medulloblastoma treated between 2003 and 2016 at a Spanish reference center were reviewed. In the absence of internationally accepted quality indicators (QIs) for pediatric CNS tumors, diagnostic, therapeutic, survival, and time QIs were defined and assessed. RESULTS: Fifty-eight patients were included, 24% were younger children (< 3 years), 36% high risk (anaplastic, metastasis, or surgical residue > 1.5 cm2), and 40% standard risk. Five-year OS was 59.2% (95% CI 47-75); 5-year PFS 36.4% (95% CI 25-53). Five main areas of quality assurance were identified: diagnosis, global strategy, frontline treatment modalities, outcomes, and long-term and end-of-life care. A set of 34 QIs was developed and applied. Lack of central pathology review, delay in the incorporation of novel molecular markers, and absence of a neurocognitive and quality-of-life evaluation program were some of the audit findings. CONCLUSIONS: This real-world research study resulted in the development of a pragmatic set of QIs, aimed to improve clinical audits and quality of care given to children and adolescents with medulloblastoma. We hope that our findings will serve as a reference to further develop a quality assurance system with specific QIs for pediatric CNS tumors in the future and that this will ultimately improve the survival and quality of life of these patients.

Mechanism of Photoluminescence Intermittency in Organic-Inorganic Perovskite Nanocrystals.

Lead halide perovskite nanocrystals have demonstrated their potential as active materials for optoelectronic applications over the past few years. Nevertheless, one issue that hampers their applicability has to do with the observation of photoluminescence intermittency, commonly referred to as "blinking", as in their inorganic counterparts. Such behavior, reported for structures well above the quantum confinement regime, has been discussed to be strongly related to the presence of charge carrier traps. In this work, we analyze the characteristics of this intermittency and explore the dependence on the surrounding atmosphere, showing evidence for the critical role played by the presence of oxygen. We discuss a possible mechanism in which a constant creation/annihilation of halide-related carrier traps takes place under light irradiation, with the dominant rate being determined by the atmosphere.

Proteínas de Bacillus thuringiensis con actividad citotóxica: Parasporinas / Proteins of Bacillus thuringiensis with cytotoxic activity: Parasporins

RESUMEN Las toxinas Cry de Bacillus thuringiensis (Bt) han sido reconocidas por su acción biocontroladora contra insectos plaga. Recientemente se ha descrito que algunas cepas de Bt codifican proteínas que no presentan actividad insecticida, pero al ser enfrentadas a líneas celulares de cáncer de diferentes tipos han demostrado actividad citotóxica. Estas proteínas han sido denominadas parasporinas (PS) y surgen como una potencial alternativa para el tratamiento del cáncer debido a que presentan citotoxicidad hacia diferentes líneas celulares cancerígenas y baja o nula citotoxicidad hacia células normales.

ABSTRACT Cry toxins from Bacillus thuringiensis (Bt) have been recognized for their biocontrol action against insect pests. Recently it has been described some strains of Bt produce proteins without insecticidal activity, but when cancer cell lines of different types are exposed to these proteins they have demonstrated cytotoxic activity. These proteins have been called parasporins (PS) and are a potential alternative for the treatment of cancer because they have high cytotoxicity in different cancer cell lines, and null or low toxic activity in normal cells.

Highly Efficient and Environmentally Stable Flexible Color Converters Based on Confined CH3NH3PbBr3 Nanocrystals.

In this work, we demonstrate a synthetic route to attain methylammonium lead bromide (CH3NH3PbBr3) perovskite nanocrystals (nc-MAPbBr3, 1.5 nm < size < 3 nm) and provide them with functionality as highly efficient flexible, transparent, environmentally stable, and adaptable color-converting films. We use nanoparticle metal oxide (MOx) thin films as porous scaffolds of controlled nanopores size distribution to synthesize nc-MAPbBr3 through the infiltration of perovskite liquid precursors. We find that the control over the reaction volume imposed by the nanoporous scaffold gives rise to a strict control of the nanocrystal size, which allows us to observe well-defined quantum confinement effects on the photo-emission, being the luminescence maximum tunable with precision between λ = 530 nm (green) and λ = 490 nm (blue). This hybrid nc-MAPbBr3/MOx structure presents high mechanical stability and permits subsequent infiltration with an elastomer to achieve a self-standing flexible film, which not only maintains the photo-emission efficiency of the nc-MAPbBr3 unaltered but also prevents their environmental degradation. Applications as adaptable color-converting layers for light-emitting devices are envisaged and demonstrated.

Room temperature synthesis of water-dispersible Ln3+:CeF3 (Ln = Nd, Tb) nanoparticles with different morphology as bimodal probes for fluorescence and CT imaging.

The singular properties of lanthanide-based inorganic nanoparticles (NPs) has raised the attention of the scientific community in biotechnological applications. In particular, those systems with two or more functionalities are especially interesting. In this work, an effective and commercially attractive procedure has been developed that renders uniform, water-dispersible Ln3+:CeF3 (Ln = Tb, Nd) NPs with different shapes and size. The method consists of the homogeneous precipitation, in a mixture of polyol and water, of cations and anions using precursors that allow the controlled release of the latter. The advantages of the reported method are related to the absence of surfactants, dispersing agents or corrosive precursors as well as to the room temperature of the process. The obtained Tb:CeF3 NPs produce an intense emission after excitation through the Ce-Tb energy transfer band located in the UV spectral region, thus being potentially useful as phosphors for in-vitro imaging purposes. On the other hand, the synthesized Nd:CeF3 NPs are good candidates for in-vivo imaging because their excitation and emission wavelengths lie in the biological windows. Finally, the excellent X-ray attenuation efficacy of the Nd:CeF3 NPs is shown, which confers double functionality to this material as both luminescence bioprobe and contrast agent for X-ray computed-tomography.

Outcome of childhood leukaemia survivors and necrosis of the femoral head treated with autologous mesenchymal stem cells.

PURPOSE: Corticoid-induced osteonecrosis (ON) of femoral head can lead to severe hip joint impairment and hip replacement, with negative impact in young survivors of acute lymphoblastic leukaemia (ALL) with long life expectancy. We aim to improve quality of life in these patients with a novel approach. METHODS/PATIENTS: Based on the regenerative capacities of mesenchymal stem cells (MSCs), we performed locally implanted autologous cell therapy in two adolescents suffering of bilateral femoral ON. This required a simple, minimally invasive surgical procedure. RESULTS: Both patients experienced significant pain relief and restoration of gait kinematic values. Radiographic evaluation showed cessation of hip collapse. No toxicities/complications were observed after a 4-year follow-up. CONCLUSIONS: Our preliminary results suggest that autologous MSCs can be considered as a novel treatment for children and young adults with ON after overcoming ALL. It may avoid hip replacement and improve quality of life of leukaemia survivors.

Plasma assisted deposition of single and multistacked TiO2 hierarchical nanotube photoanodes.

We present herein an evolved methodology for the growth of nanocrystalline hierarchical nanotubes combining physical vapor deposition of organic nanowires (ONWs) and plasma enhanced chemical vacuum deposition of anatase TiO2 layers. The ONWs act as vacuum removable 1D and 3D templates, with the whole process occurring at temperatures ranging from RT to 250 °C. As a result, a high density of hierarchical nanotubes with tunable diameter, length and tailored wall microstructures are formed on a variety of processable substrates as metal and metal oxide films or nanoparticles including transparent conductive oxides. The reiteration of the process leads to the development of an unprecedented 3D nanoarchitecture formed by stacking the layers of hierarchical TiO2 nanotubes. As a proof of concept, we present the superior performance of the 3D nanoarchitecture as a photoanode within an excitonic solar cell with efficiencies as high as 4.69% for a nominal thickness of the anatase layer below 2.75 µm. Mechanical stability and straightforward implementation in devices are demonstrated at the same time. The process is extendable to other functional oxides fabricated by plasma-assisted methods with readily available applications in energy harvesting and storage, catalysis and nanosensing.

Management and outcome of children with neuroendocrine tumors of the appendix in Spain: Is there room for improvement?

PURPOSE: Neuroendocrine tumors (NETs) are, after lymphomas, the most frequent gastrointestinal tumors in children, mainly located in the appendix. Best management remains unclear, given the absence of pediatric guidelines. We present the first Spanish series of pediatric patients with NETs. PATIENTS AND METHODS: Retrospective study of all pediatric patients (<18 years) with NET treated in four oncology reference institutions in Spain between 1994 and 2015. RESULTS: Seventeen patients were included. All patients presented with acute abdomen. TNM stage was T1a (82%) and T1b (12%). Extension study was heterogenous, with only 4 patients undergoing an OctreoScan. Four patients met criteria for second surgery (affected surgical margins or mesoappendix invasion), but it was only performed in two. Despite the diverse management, none of the patients relapsed during follow-up. CONCLUSIONS: The disparity in diagnostic tests, second surgery criteria and follow-up shown in this study highlights the need for specific pediatric guidelines.

Experiencia del uso de terapia biológica en pacientes con enfermedad inflamatoria intestinal en un hospital público / Experience in the use of biological therapy in IBD patients in a public hospital

Biological therapy plays an important role in the treatment of inflammatory bowel disease (IBD). However, the use of these drugs is limited due to fears about their side effects. Aim: To report the experience with the use of infliximab/adalimumab in IBD patients in a public hospital. Material and Methods: Descriptive study of a historical cohort of IBD patients treated with infliximab and adalimumab between April 2012 and July 2014. The clinical response was considered favourable when general, intestinal and extra intestinal symptoms subsided after the induction therapy. In addition, endoscopic and/or imaging response was evaluated at three and six months of treatment. Results: Fifteen out of 162 patients, aged 17 to 52 years (7 women) were included. Seven had Crohn´s Disease, 7 had ulcerative colitis and one had non-classifiable IBD. Biological therapy was indicated due to conventional refractory disease in all patients. All patients received combined treatment with immunosuppressive medications. A favorable clinical response was observed in 93 percent after induction therapy and 73 percent showed endoscopic/imagining remission after 3-6 months. Only one patient experienced side effects associated to the biological therapy, which did not result in discontinuation or treatment interruption. Conclusions: In this cohort of IBD patients treated in a public hospital, the use of infliximab/adalimumab was associated with favorable clinical and endoscopic evolution, post induction therapy with no major side effects.

La terapia biológica tiene un papel fundamental en el tratamiento de la enfermedad inflamatoria intestinal (EII). Sin embargo, el uso de estos fármacos es escaso debido a los costos y los temores sobre los efectos secundarios. Objetivo: Dar a conocer la experiencia en el uso de infliximab/adalimumab en pacientes con EII atendidos en un hospital público de nuestro país. Material y Métodos: Estudio descriptivo de una cohorte histórica de pacientes con EII tratados con infliximab y adalimumab entre abril de 2012 y julio de 2014. La respuesta clínica fue considerada favorable cuando los síntomas generales, intestinales y extra-intestinales desaparecieron después de la terapia de inducción. Además se evaluó la respuesta endoscópica/radiológica a los 3 y 6 meses de tratamiento. Resultados: De un total de 162 pacientes con EII, 15 fueron tratados con terapia biológica, con edad entre 17-52 años (7 mujeres). Siete presentaban el diagnóstico de enfermedad de Crohn, siete colitis ulcerosa y uno EII no clasificable. En todos se inició terapia biológica debido a la presencia de refractariedad a la terapia convencional. Todos recibieron terapia combinada con inmunosupresores. Se observó una respuesta clínica favorable en 93 por ciento después de la terapia de inducción y 73 por ciento tuvo una mejoría endoscópica después de 3-6 meses. Sólo un paciente presentó un evento adverso a terapia biológica, el cual no motivó la interrupción del tratamiento. Conclusiones: En esta cohorte de pacientes con EII tratados en un hospital público, el uso de infliximab/adalimumab se asoció con mejoría clínica y endoscópica post terapia de inducción, sin mayores efectos secundarios.

Self-Lubricity of WSex Nanocomposite Coatings.

Transition metal chalcogenides with lamellar structure are known for their use in tribological applications although limited to vacuum due to their easy degradation in the presence of oxygen and/or moisture. Here we present a tailored WSex coating with low friction (0.07) and low wear rates (3×10(-7) mm3 Nm(-1)) even in ambient air. To understand the low friction behavior and lower chemical reactivity a tribological study is carried out in a high-vacuum tribometer under variable pressure (atmospheric pressure to 1×10(-8) mbar). A detailed investigation of the film nanostructure and composition by advanced transmission electron microscopy techniques with nanoscale resolution determined that the topmost layer is formed by nanocrystals of WSe2 embedded in an amorphous matrix richer in W, a-W(Se). After the friction test, an increased crystalline order and orientation of WSe2 lamellas along the sliding direction were observed in the interfacial region. On the basis of high angle annular dark field, scanning transmission electron microscopy, and energy dispersive X-ray analysis, the release of W atoms from the interstitial basal planes of the a-W(Se) phase is proposed. These W atoms reaching the surface, play a sacrificial role preventing the lubricant WSe2 phase from oxidation. The increase of the WSe2 crystalline order and the buffer effect of W capturing oxygen atoms would explain the enhanced chemical and tribological response of this designed nanocomposite material.

[Multidisciplinary management of retinoblastoma: Experience in 37 eyes]. / Manejo multidisciplinario en retinoblastoma: experiencia en 37 ojos.

OBJECTIVE: To report the results of the multidisciplinary management of patients with retinoblastoma, including survival, enucleation rate, and systemic chemoreduction success. METHODS: A retrospective study was conducted on 27 patients (37 eyes) diagnosed with retinoblastoma, and treated by a multidisciplinary team in San Juan de Dios Hospital. Demographic information, clinical characterization, survival, local and systemic treatments were included in the analysis. Patients treated with intra-arterial chemotherapy (IAC) were also reviewed. RESULTS: The study included14 male patients (52%). The median of age at presentation was 8 months (0.16-90). The median follow-up time was 33 ± 21 months. The diagnosis was made in 10 (37%) cases after 15 months old, with a median of 35 months (24-90). 17 (63%) patients had unilateral retinoblastoma, and 10 (37%) bilateral retinoblastoma. Leukocoria, isolated or associated with other signs, was the most frequent reason for referral (63%). Global enucleation rate was 57% (n=21), being the primary treatment in 15 (55%) patients. Enucleation rate in unilateral retinoblastoma was 76.5%, and for bilateral retinoblastoma, it was 60% for one eye and 10% for both. Systemic chemotherapy was prescribed in 17 (63%) patients, with a mean number of cycles of 5.3 ± 2.1. The overall success of chemoreduction and focal therapy in order to avoid external radiotherapy and/or enucleation was 68%. Three patients were treated with IAC as a salvage therapy, controlling the tumor in 2 patients at 6 months of follow-up. These are the first cases reported in Chile. Survival rate was 100%. CONCLUSION: Multidisciplinary management of retinoblastoma led to a survival rate and morbidity comparable with international reports.

Trasplante de microbiota fecal en paciente con colitis ulcerosa e infección refractaria por: revisión de la literatura a partir de un caso clínico / Fecal microbiota transplantation in patient with ulcerative colitis and refractory infection due to: review of the literature based on a clinical case

Infection (CDI) is increasing both in the hospital environment as in the outpatient setting, and is associated with prior use of antibiotics, hospitalizations and inflammatory bowel disease (IBD), among others. It is also characterized by a high rate of recurrence with the usual antibiotic treatment, which increases with greater number of episodes, reaching up to 65 percent. In this context, the transplantation of fecal microbiota (FMT) emerges as recurrent CDI therapy, achieving success rates exceeding 90 percent, including in IBD patients, with minimum rates of recurrence. To achieve such efficiency, the colonization by the donated microbiota in the recipient is critical. The role of FMT is still unclear in IBD therapy not associated with CDI. Although there are great differences in the methodology of FMT, the process has been standardized even creating banks of frozen fecal samples, without reducing its effectiveness. FMT is a safe procedure, without serious adverse events, and accepted by the potential beneficiary population. There are few reported cases of refractory CDI management with FMT. Since 2012, the FMT in CDI and IBD publications have increased significantly, but in our country there are only few reports of this therapeutic strategy. We present a patient with ulcerative colitis and conventional antimicrobial management resistant CDI, which was successfully treated with FMT in a public hospital in Chile.

La infección por Clostridium difficile (ICD) está en aumento tanto en el ambiente hospitalario como ambulatorio, y se asocia a uso previo de antibióticos, hospitalización y enfermedades inflamatorias intestinales (EII), entre otros. Se caracteriza además por su alta tasa de recurrencia con el tratamiento antimicrobiano habitual, que aumenta con el mayor número de episodios alcanzando hasta 65 por ciento. En este contexto, el trasplante de microbiota fecal (TMF) surge como terapia para la ICD recurrente, logrando tasas de éxito superiores a 90 por ciento, incluyendo pacientes con EII, con mínimas tasas de recurrencia. Para lograr esa eficacia, la colonización por la microbiota donada en el receptor es fundamental. Aún no está claro el rol del TMF en la terapia de EII no asociada a ICD. Aunque existe gran heterogeneidad en la metodología del TMF, el proceso se ha ido estandarizando incluso hasta llegar a la creación de bancos de muestra fecal congelada, sin disminuir su efectividad. El TMF es un procedimiento seguro, sin eventos adversos graves y aceptado por la población potencialmente beneficiaria de él. Existen pocos casos publicados de manejo de ICD refractaria con TMF. Desde el 2012 el número de publicaciones sobre TMF en ICD y en EII ha aumentado considerablemente, sin embargo, en nuestro país los reportes sobre esta estrategia terapéutica son escasos. Presentamos el caso de un paciente con colitis ulcerosa e ICD refractaria al manejo antimicrobiano habitual, que se trató exitosamente con TMF en un hospital público de Chile.

A new bottom-up methodology to produce silicon layers with a closed porosity nanostructure and reduced refractive index.

A new approach is presented to produce amorphous porous silicon coatings (a-pSi) with closed porosity by magnetron sputtering of a silicon target. It is shown how the use of He as the process gas at moderated power (50-150 W RF) promotes the formation of closed nanometric pores during the growth of the silicon films. The use of oblique-angle deposition demonstrates the possibility of aligning and orientating the pores in one direction. The control of the deposition power allows the control of the pore size distribution. The films have been characterized by a variety of techniques, including scanning and transmission electron microscopy, electron energy loss spectroscopy, Rutherford back scattering and x-ray photoelectron spectroscopy, showing the incorporation of He into the films (most probably inside the closed pores) and limited surface oxidation of the silicon coating. The ellipsometry measurements show a significant decrease in the refractive index of porous coatings (n(500 nm) = 3.75) in comparison to dense coatings (n(500 nm) = 4.75). The capability of the method to prepare coatings with a tailored refractive index is therefore demonstrated. The versatility of the methodology is shown in this paper by preparing intrinsic or doped silicon and also depositing (under DC or RF discharge) a-pSi films on a variety of substrates, including flexible materials, with good chemical and mechanical stability. The fabrication of multilayers of silicon films of controlled refractive index in a simple (one-target chamber) deposition methodology is also presented.

Characterisation of Co@Fe3O4 core@shell nanoparticles using advanced electron microscopy.

Cobalt nanoparticles were synthesised via the thermal decomposition of Co2(CO)8 and were coated in iron oxide using Fe(CO)5. While previous work focused on the subsequent thermal alloying of these nanoparticles, this study fully elucidates their composition and core@shell structure. State-of-the-art electron microscopy and statistical data processing enabled chemical mapping of individual particles through the acquisition of energy-filtered transmission electron microscopy (EFTEM) images and detailed electron energy loss spectroscopy (EELS) analysis. Multivariate statistical analysis (MSA) has been used to greatly improve the quality of elemental mapping data from core@shell nanoparticles. Results from a combination of spatially resolved microanalysis reveal the shell as Fe3O4 and show that the core is composed of oxidatively stable metallic Co. For the first time, a region of lower atom density between the particle core and shell has been observed and identified as a trapped carbon residue attributable to the organic capping agents present in the initial Co nanoparticle synthesis.

Behaviour of Au-citrate nanoparticles in seawater and accumulation in bivalves at environmentally relevant concentrations.

The degree of aggregation and/or coalescence of Au-citrate nanoparticles (AuNPs, mean size 21.5 ± 2.9 nm), after delivery in simulated seawater, are shown to be concentration-dependent. At low concentrations no coalescence and only limited aggregation of primary particles were found. Experiments were performed in which the marine bivalve (Ruditapes philippinarum) was exposed to AuNPs or dissolved Au and subsequently, bivalve tissues were studied by Scanning and Transmission Electron Microscopy and chemical analyses. We show that the bivalve accumulates gold in both cases within either the digestive gland or gill tissues, in different concentrations (including values of predicted environmental relevance). After 28 days of exposure, electron-dense deposits (corresponding to AuNPs, as proven by X-ray microanalysis) were observed in the heterolysosomes of the digestive gland cells. Although non-measurable solubility of AuNPs in seawater was found, evidence is presented of the toxicity produced by Au(3+) dissolved species (chloroauric acid solutions) and its relevance is discussed.