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Inhalational lung injury should be considered in patients presenting with acute respiratory symptoms and a history of occupational or recreational exposure to toxic substances. We present the case of a 29-year-old patient who developed pneumonitis following usage of waterproofing sealant spray in an enclosed space, despite the use of a dust mask. The patient was managed with oxygen therapy, corticosteroids and bronchodilators. He made a complete clinical recovery with resolution of almost all changes seen on computerised tomography (CT) imaging within 7 days.
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Neumonía , Cuartos de Baño , Masculino , Humanos , Adulto , Disnea , Pulmón , Terapia por Inhalación de OxígenoRESUMEN
A 51-year-old man presented with mild headache followed by sudden onset of right sided weakness and dysarthria on the background of one week history of right sided sciatica and malaise. He was apparently immunocompetent with only past medical history being hypertension. There was no consumption of tobacco or excess alcohol and he previously had normal liver and renal function.
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Isquemia Encefálica , Accidente Cerebrovascular Isquémico , Meningoencefalitis , Accidente Cerebrovascular , Adulto , Humanos , Masculino , Meningoencefalitis/diagnóstico , Persona de Mediana Edad , Streptococcus , Accidente Cerebrovascular/diagnóstico , Accidente Cerebrovascular/etiologíaRESUMEN
The methanol-to-hydrocarbons reaction refers collectively to a series of important industrial catalytic processes to produce either olefins or gasoline. Mechanistically, methanol conversion proceeds through a 'pool' of hydrocarbon species. For the methanol-to-olefins process, these species can be delineated broadly into 'desired' lighter olefins and 'undesired' heavier fractions that cause deactivation in a matter of hours. The crux in further catalyst optimization is the ability to follow the formation of carbonaceous species during operation. Here, we report the combined results of an operando Kerr-gated Raman spectroscopic study with state-of-the-art operando molecular simulations, which allowed us to follow the formation of hydrocarbon species at various stages of methanol conversion. Polyenes are identified as crucial intermediates towards formation of polycyclic aromatic hydrocarbons, with their fate determined largely by the zeolite topology. Notably, we provide the missing link between active and deactivating species, which allows us to propose potential design rules for future-generation catalysts.
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AIM: To report on a snap audit of all departments in the UK as to the value of preoperative thoracic imaging, preferably computed tomography (CT), of patients undergoing any surgery to assess for changes consistent with COVID-19 preoperatively. MATERIALS AND METHODS: All Imaging departments in the UK were contacted and asked to record the number of preoperative CT examinations performed in patients being considered for both emergency and elective surgical intervention over a 5-day period in May 2020. RESULTS: Forty-seven percent of departments replied with data provided on >820 patients. Nineteen percent of additional preoperative CT was in patients undergoing elective intervention and 81% in patients presenting with surgical abdominal pain. There was a high rate of false positives in patients who tested negative for COVID-19, producing a sensitivity for thoracic CT of 68.4%. CONCLUSION: This UK-wide audit demonstrates that a large number of additional thoracic imaging examinations over a 5-day period were performed with a low sensitivity for the identification of COVID-19 in this preoperative group of patients. Given these findings, it is difficult to justify this additional examination in this group of patients.
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Betacoronavirus , Infecciones por Coronavirus/diagnóstico por imagen , Auditoría Médica/métodos , Neumonía Viral/diagnóstico por imagen , Cuidados Preoperatorios/métodos , Procedimientos Quirúrgicos Operativos , Tomografía Computarizada por Rayos X/métodos , COVID-19 , Humanos , Pulmón/diagnóstico por imagen , Auditoría Médica/estadística & datos numéricos , Pandemias , Estudios Prospectivos , Radiografía Torácica , Reproducibilidad de los Resultados , SARS-CoV-2 , Sensibilidad y Especificidad , Reino UnidoRESUMEN
Correction for 'Correlation between Cu ion migration behaviour and deNOx activity in Cu-SSZ-13 for the standard NH3-SCR reaction' by A. M. Beale et al., Chem. Commun., 2016, 52, 6170-6173.
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We report the results from the first 5D tomographic diffraction imaging experiment of a complex Ni-Pd/CeO2-ZrO2/Al2O3 catalyst used for methane reforming. This five-dimensional (three spatial, one scattering and one dimension to denote time/imposed state) approach enabled us to track the chemical evolution of many particles across the catalyst bed and relate these changes to the gas environment that the particles experience. Rietveld analysis of some 2 × 106 diffraction patterns allowed us to extract heterogeneities in the catalyst from the Å to the nm and to the µm scale (3D maps corresponding to unit cell lattice parameters, crystallite sizes and phase distribution maps respectively) under different chemical environments. We are able to capture the evolution of the Ni-containing species and gain a more complete insight into the multiple roles of the CeO2-ZrO2 promoters and the reasons behind the partial deactivation of the catalyst during partial oxidation of methane.
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AIM: To determine the utilisation of computed tomography pulmonary angiography (CTPA) and lung scintigraphy in the UK, and to assess their diagnostic qualities in the investigation of suspected pulmonary embolism (PE) in pregnancy. MATERIALS AND METHODS: Data were collected via electronic questionnaire in the UK from 24 sites. Data on the choice of imaging technique, radiation dose, technical adequacy, weeks' gestation, presenting symptoms, and further management of patients with indeterminate imaging were collected. RESULTS: The sample represented a population of 15.5 million and showed wide variation in the probability of investigation of suspected PE with rates per live birth of 0.06-2.2%. Nine hundred and ninety-one patients were imaged and there were 48 positive scans, an incidence of 0.038%. Of the 269 CTPAs performed, 5.9% were positive, 8.9% were technically inadequate. Of the 769 scintigraphy scans performed, 3.8% were positive and 9.1% were indeterminate; 63% of positive scans were in the third trimester. Most inadequate/indeterminate scans were in the third trimester. The calculated typical radiation dose to the breast and fetus from CTPA ranged from 14 to 2 mGy and 0.02 to 0.002mGy, respectively, and approximately 0.28 and 0.2 mGy, respectively, from scintigraphy. CONCLUSION: The incidence of PE in this population was extremely low and the number of indeterminate or inadequate scans was comparable. This suggests choice of imaging should be made based upon availability and radiation exposure.
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Angiografía por Tomografía Computarizada/estadística & datos numéricos , Pautas de la Práctica en Medicina , Complicaciones Hematológicas del Embarazo/diagnóstico por imagen , Embolia Pulmonar/diagnóstico por imagen , Adulto , Femenino , Encuestas de Atención de la Salud , Humanos , Embarazo , Cintigrafía/estadística & datos numéricos , Estudios Retrospectivos , Reino UnidoRESUMEN
Here we present the results of a synchrotron-based in situ, time-resolved PXRD study during activation of two Cu-SSZ-13 catalysts under O2/He and one during standard NH3-SCR reaction conditions to obtain insight into the behaviour of Cu ions. The results obtained indicate that deNOx activity is inexorably linked with occupancy of the zeolite 6r.
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We report the development of laboratory based hyperspectral X-ray computed tomography which allows the internal elemental chemistry of an object to be reconstructed and visualised in three dimensions. The method employs a spectroscopic X-ray imaging detector with sufficient energy resolution to distinguish individual elemental absorption edges. Elemental distributions can then be made by K-edge subtraction, or alternatively by voxel-wise spectral fitting to give relative atomic concentrations. We demonstrate its application to two material systems: studying the distribution of catalyst material on porous substrates for industrial scale chemical processing; and mapping of minerals and inclusion phases inside a mineralised ore sample. The method makes use of a standard laboratory X-ray source with measurement times similar to that required for conventional computed tomography.
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We report the results from an operando XRD-CT study of a working catalytic membrane reactor for the oxidative coupling of methane. These results reveal the importance of the evolving solid state chemistry during catalytic reaction, particularly the chemical interaction between the catalyst and the oxygen transport membrane.
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The ever increasing demand to develop highly fuel efficient engines coincides with the need to minimize air pollution originating from the exhaust gases of internal combustion engines. Dramatically improved fuel efficiency can be achieved at air-to-fuel ratios much higher than stoichiometric. In the presence of oxygen in large excess, however, traditional three-way catalysts are unable to reduce NOx. Among the number of lean-NOx reduction technologies, selective catalytic reduction (SCR) of NOx by NH3 over Cu- and Fe-ion exchanged zeolite catalysts has been extensively studied over the past 30+ years. Despite the significant advances in developing a viable practical zeolite-based catalyst for lean NOx reduction, the insufficient hydrothermal stabilities of the zeolite structures considered cast doubts about their real-world applicability. During the past decade renewed interest in zeolite-based lean NOx reduction was spurred by the discovery of the very high activity of Cu-SSZ-13 (and the isostructural Cu-SAPO-34) in the NH3-SCR of NOx. These new, small-pore zeolite-based catalysts not only exhibited very high NOx conversion and N2 selectivity, but also exhibited exceptionally high hydrothermal stability at high temperatures. In this review we summarize the key discoveries of the past â¼5 years that led to the introduction of these catalysts into practical applications. This review first briefly discusses the structure and preparation of the CHA structure-based zeolite catalysts, and then summarizes the key learnings of the rather extensive (but not complete) characterisation work. Then we summarize the key findings of reaction kinetic studies, and provide some mechanistic details emerging from these investigations. At the end of the review we highlight some of the issues that still need to be addressed in automotive exhaust control catalysis.
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BACKGROUND: Hypertrophic cardiomyopathy (HCM) is the most common monogenic cardiac condition, with a range of investigation and management options available. Recent research has recommended management within multidisciplinary-dedicated HCM centres. AIM: To assess the clinical impact of attendance at a specialised clinic on the management of HCM. METHODS: A retrospective study of patients attending the HCM Clinic @ The Alfred during the first 2 years of operation was performed. Outcome measures comprised improvements in management of HCM as a result of attending the clinic including risk stratification and further investigations, medication changes, referral for implantable cardioverter-defibrillators (ICD) and septal reduction therapy, and screening of first-degree relatives (FDR). RESULTS: Following specialised clinic attendance, there was an increase in patients investigated with 24-h Holter monitoring by 39%, stress echocardiography by 21% and cardiac magnetic resonance imaging by 70%. Medications were optimised in 47% of patients. Six per cent of patients underwent ICD implantation and 13% underwent septal myectomy. Seventy new FDR were screened identifying 10 new cases of HCM. CONCLUSIONS: Attendance at our specialised HCM clinic leads to facilitation of cardiac investigations, optimisation of medical therapy, streamlining of referrals for ICD implantation and septal reduction therapy, and improved family screening. Referral to a specialised clinic offering comprehensive management should be considered for all patients with HCM.
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Cardiomiopatía Hipertrófica/diagnóstico , Cardiomiopatía Hipertrófica/terapia , Servicio Ambulatorio en Hospital/normas , Femenino , Humanos , Masculino , Persona de Mediana Edad , Derivación y Consulta/normas , Estudios RetrospectivosRESUMEN
The physicochemical state of a catalyst is a key factor in determining both activity and selectivity; however these materials are often not structurally or compositionally homogeneous. Here we report on the 3-dimensional imaging of an industrial catalyst, Mo-promoted colloidal Pt supported on carbon. The distribution of both the active Pt species and Mo promoter have been mapped over a single particle of catalyst using microfocus X-ray fluorescence computed tomography. X-ray absorption near edge spectroscopy (XANES) and extended X-ray absorption fine structure revealed a mixed local coordination environment, including the presence of both metallic Pt clusters and Pt chloride species, but also no direct interaction between the catalyst and Mo promoter. We also report on the benefits of scanning µ-XANES computed tomography for chemical imaging, allowing for 2- and 3-dimensional mapping of the local electronic and geometric environment, in this instance for both the Pt catalyst and Mo promoter throughout the catalyst particle.
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BACKGROUND: Hypertrophic cardiomyopathy (HCM) causes significant morbidity and sudden death. First-degree relatives (FDR) of affected patients are at risk due to autosomal dominant inheritance. Guidelines recommend clinical screening, including echocardiography, for all FDR. AIM: We sought to determine adherence to these guidelines, and whether a specialised HCM clinic improves screening rates. METHOD: This 12-month prospective follow-up study obtained family pedigrees from all patients referred to the HCM Clinic @ The Alfred. The number of living FDR was determined, and whether they had previously been assessed by echocardiography. One year after a coordinated clinic-based family screening approach was instituted, the number of additionally screened FDR was recorded. RESULTS: Three hundred and eight living FDR of 61 HCM patients were identified. Of these, echocardiography had previously been performed in only 80 (26%), yielding 13 (16%) additional cases of HCM. Twelve months after attendance at our clinic, 51 additional FDR were screened (64% improvement) and 8 new cases of HCM were identified. CONCLUSIONS: Recommended family screening for HCM is underperformed, resulting in missed opportunities to detect subclinical HCM. A coordinated approach through a specialised HCM clinic improves screening rates, thus referral to such a service should be considered for all patients with HCM and their families.
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Cardiomiopatía Hipertrófica/diagnóstico , Cardiomiopatía Hipertrófica/genética , Predisposición Genética a la Enfermedad/genética , Pruebas Genéticas/normas , Adulto , Anciano , Estudios de Cohortes , Femenino , Estudios de Seguimiento , Pruebas Genéticas/métodos , Humanos , Masculino , Persona de Mediana Edad , Linaje , Estudios ProspectivosRESUMEN
Three different types of NH3 species can be simultaneously present on Cu(2+)-exchanged CHA-type zeolites, commonly used in Ammonia Selective Catalytic Reduction (NH3-SCR) systems. These include ammonium ions (NH4(+)), formed on the Brønsted acid sites, [Cu(NH3)4](2+) complexes, resulting from NH3 coordination with the Cu(2+) Lewis sites, and NH3 adsorbed on extra-framework Al (EFAl) species, in contrast to the only two reacting NH3 species recently reported on Cu-SSZ-13 zeolite. The NH4(+) ions react very slowly in comparison to NH3 coordinated to Cu(2+) ions and are likely to contribute little to the standard NH3-SCR process, with the Brønsted groups acting primarily as NH3 storage sites. The availability/reactivity of NH4(+) ions can be however, notably improved by submitting the zeolite to repeated exchanges with Cu(2+), accompanied by a remarkable enhancement in the low temperature activity. Moreover, the presence of EFAl species could also have a positive influence on the reaction rate of the available NH4(+) ions. These results have important implications for NH3 storage and availability in Cu-Chabazite-based NH3-SCR systems.
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Amoníaco/química , Cobre/química , Compuestos Organometálicos/química , Zeolitas/química , Catálisis , Modelos Moleculares , Oxidación-Reducción , Propiedades de Superficie , TemperaturaRESUMEN
An eighty nine year old woman was admitted with a two day history of abdominal pain and vomiting. Two months previously she had undergone a Hartmann's procedure following a sigmoid perforation secondary to diverticular disease. A hiatus hernia had been noted on a CT undertaken prior to her recent surgery.
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Causas de Muerte , Servicio de Urgencia en Hospital , Hernia Hiatal/diagnóstico por imagen , Hernia Hiatal/mortalidad , Anciano , Anciano de 80 o más Años , Enfermedad Crítica/terapia , Progresión de la Enfermedad , Tratamiento de Urgencia/métodos , Femenino , Estudios de Seguimiento , Hernia Hiatal/cirugía , Humanos , Radiografía Torácica/métodos , Medición de Riesgo , Muestreo , Índice de Severidad de la Enfermedad , Tasa de Supervivencia , Tomografía Computarizada por Rayos X/métodos , Resultado del TratamientoRESUMEN
OBJECTIVE: To determine Nd:YAG laser energy requirements for posterior capsulotomy and intraocular lens (IOL) damage threshold for foldable acrylic IOLs as compared to traditional polymethylmethacrylate (PMMA). MATERIALS AND PROCEDURES: Four groups of five-six fresh canine cadaver eyes were used in this study. The groups included (1) unaltered eyes (2) aphakic eyes (3) eyes implanted with PMMA IOLs, and (4) eyes implanted with acrylic IOLs. Laser energy was delivered to the posterior capsule in grid fashion for 10 sites each of five levels of laser energy ranging from 0.5 mJ to 9 mJ. Number of successful capsulotomy sites was recorded based on slit-lamp observation. Sites of IOL damage were evaluated using scanning electron microscopy (SEM). Statistical analysis of number of capsulotomies and IOL defects per laser energy level was conducted among and between groups using anova with Tukey's HSD test. RESULTS: When comparing groups (a) including all energy levels (n = 25) and (b) by specific energy levels (n = 5), there was no significant difference (P < 0.05) in number of successful capsulotomy sites between IOL types. The 50% incidence threshold for successful capsulotomy was 2.74 mJ for acrylic IOLs and 2.64 mJ for PMMA IOLs. Energy-dependent damage to both types of IOL was detected for medium, high-medium, and high laser energy. Calculated 50% damage threshold was 4.9 mJ for acrylic IOL and 5.7 mJ for PMMA IOL. Damage to the IOL varied subjectively between IOL type, but there was no significant difference in number of defects caused, with the exception of high-medium energy. CONCLUSIONS: Both posterior lens capsules and IOLs were disrupted in an energy-dependent manner with minimal difference in number of capsulotomy sites or damage to the IOL between acrylic and PMMA IOLs. A therapeutic margin between capsulotomy threshold (2.6-2.7 mJ) and IOL damage threshold (4.9-5.7 mJ) was determined to reliably achieve capsulotomies with minimal IOL damage for both acrylic and PMMA IOLs in normal canine cadaver eyes.
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Terapia por Láser/efectos adversos , Cápsula del Cristalino/cirugía , Lentes Intraoculares , Acrilatos , Animales , Perros , Complicaciones Intraoperatorias , Modelos AnatómicosRESUMEN
A 12-yr-old intact male red wolf (Canis rufus) diagnosed with bilateral idiopathic dry eye was treated with subconjunctival drug delivery implants designed to release therapeutic levels of cyclosporine from 12-24 mo. Normal tear production and corneal health has been maintained, alleviating the need for daily handling of the animal for topical medication.
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Ciclosporina/uso terapéutico , Inmunosupresores/uso terapéutico , Queratoconjuntivitis Seca/veterinaria , Lobos , Animales , Implantes de Medicamentos/uso terapéutico , Queratoconjuntivitis Seca/tratamiento farmacológico , Masculino , Resultado del TratamientoRESUMEN
Bone bruising demonstrated by MRI is discussed with histological findings and proposed classifications. The effects of the mechanism of injury on bone bruising at the knee and the natural history of the process are reviewed. The relationship of bone bruising to osteochondral sequelae and to osteoarthritis are considered.