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Metal-zeolite composites with metal (oxide) and acid sites are promising catalysts for integrating multiple reactions in tandem to produce a wide variety of wanted products without separating or purifying the intermediates. However, the conventional design of such materials often leads to uncontrolled and non-ideal spatial distributions of the metal inside/on the zeolites, limiting their catalytic performance. Here we demonstrate a simple strategy for synthesizing double-shelled, contiguous metal oxide@zeolite hollow spheres (denoted as MO@ZEO DSHSs) with controllable structural parameters and chemical compositions. This involves the self-assembly of zeolite nanocrystals onto the surface of metal ion-containing carbon spheres followed by calcination and zeolite growth steps. The step-by-step formation mechanism of the material is revealed using mainly in situ Raman spectroscopy and X-ray diffraction and ex situ electron microscopy. We demonstrate that it is due to this structure that an Fe2O3@H-ZSM-5 DSHSs-showcase catalyst exhibits superior performance compared with various conventionally structured Fe2O3-H-ZSM-5 catalysts in gasoline production by the Fischer-Tropsch synthesis. This work is expected to advance the rational synthesis and research of hierarchically hollow, core-shell, multifunctional catalyst materials.
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OBJECTIVE: To evaluate the diagnostic quality of photon-counting detector (PCD) computed tomography (CT) in patients undergoing lung cancer screening compared with conventional energy-integrating detector (EID) CT in a prospective multireader study. MATERIALS: Patients undergoing lung cancer screening with conventional EID-CT were prospectively enrolled and scanned on a PCD-CT system using similar automatic exposure control settings and reconstruction kernels. Three thoracic radiologists blinded to CT system compared PCD-CT and EID-CT images and scored examinations using a 5-point Likert comparison score (-2 [left image is worse] to +2 [left image is better]) for artifacts, sharpness, image noise, diagnostic image quality, emphysema visualization, and lung nodule evaluation focusing on the border. Post hoc correction of Likert scores was performed such that they reflected PCD-CT performance in comparison to EID-CT. A nonreader radiologist measured objective image noise. RESULTS: Thirty-three patients (mean, 66.9 ± 5.6 years; 11 female; body mass index; 30.1 ± 5.1 kg/m 2 ) were enrolled. Mean volume CT dose index for PCD-CT was lower (0.61 ± 0.21 vs 0.73 ± 0.22; P < 0.001). Pooled reader results showed significant differences between imaging modalities for all comparative rankings ( P < 0.001), with PCD-CT favored for sharpness, image noise, image quality, and emphysema visualization and lung nodule border, but not artifacts. Photon-counting detector CT had significantly lower image noise (74.4 ± 10.5 HU vs 80.1 ± 8.6 HU; P = 0.048). CONCLUSIONS: Photon-counting detector CT with similar acquisition and reconstruction settings demonstrated improved image quality and less noise despite lower radiation dose, with improved ability to depict pulmonary emphysema and lung nodule borders compared with EID-CT at low-dose lung cancer CT screening.
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Enfisema , Neoplasias Pulmonares , Enfisema Pulmonar , Humanos , Feminino , Detecção Precoce de Câncer , Estudos Prospectivos , Neoplasias Pulmonares/diagnóstico por imagem , Fótons , Imagens de Fantasmas , Tomografia Computadorizada por Raios X/métodosRESUMO
BACKGROUND/OBJECTIVE: A subset of patients with idiopathic inflammatory myopathy (IIM) develops highly fatal, rapidly progressive interstitial lung disease (RP-ILD). Treatment strategies consist of glucocorticoid and adjunctive immunosuppressive therapies. Plasma exchange (PE) is an alternative therapy, but its benefit is unclear. In this study, we aimed to determine whether PE benefited outcomes for patients with RP-ILD. METHODS: In this medical records review study, we compared baseline characteristics and clinical outcomes for 2 groups of patients with IIM-related RP-ILD: those who received and did not receive PE. RESULTS: Our cohort consisted of 15 patients, 9 of whom received PE. Baseline demographic characteristics and severity of lung, skin, and musculoskeletal disease between the 2 groups of patients were not significantly different. Five patients required mechanical ventilation (2, PE; 3, no PE). Plasma exchange was generally a third-line adjunctive treatment option. The PE group had a longer median (interquartile range) hospitalization (27.0 [23.0-36.0] days) than the non-PE group (12.0 [8.0-14.0] days) ( p = 0.02). There was a potential benefit in 30-day mortality improvement in those receiving PE (0% vs 33%, p = 0.14), with a statistically significant improvement in 2 important composite end points including 30-day mortality or need for lung transplant (0% vs 50%, p = 0.04) and 1-year mortality or need for lung transplant or hospital readmission for RP-ILD in those receiving PE (22% vs 83%, p = 0.04). CONCLUSIONS: Plasma exchange may be an underutilized, safe salvage therapy for patients with IIM-related RP-ILD when other immunosuppressive therapies fail.
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Doenças Pulmonares Intersticiais , Miosite , Humanos , Troca Plasmática , Doenças Pulmonares Intersticiais/terapia , Doenças Pulmonares Intersticiais/complicações , Miosite/complicações , Miosite/terapia , Pulmão , Plasmaferese , Autoanticorpos , Estudos RetrospectivosRESUMO
Oxide-derived copper electrodes have displayed a boost in activity and selectivity toward valuable base chemicals in the electrochemical carbon dioxide reduction reaction (CO2RR), but the exact interplay between the dynamic restructuring of copper oxide electrodes and their activity and selectivity is not fully understood. In this work, we have utilized time-resolved surface-enhanced Raman spectroscopy (TR-SERS) to study the dynamic restructuring of the copper (oxide) electrode surface and the adsorption of reaction intermediates during cyclic voltammetry (CV) and pulsed electrolysis (PE). By coupling the electrochemical data to the spectral features in TR-SERS, we study the dynamic activation of and reactions on the electrode surface and find that CO2 is already activated to carbon monoxide (CO) during PE (10% Faradaic efficiency, 1% under static applied potential) at low overpotentials (-0.35 VRHE). PE at varying cathodic bias on different timescales revealed that stochastic CO is dominant directly after the cathodic bias onset, whereas no CO intermediates were observed after prolonged application of low overpotentials. An increase in cathodic bias (-0.55 VRHE) resulted in the formation of static adsorbed CO intermediates, while the overall contribution of stochastic CO decreased. We attribute the low-overpotential CO2-to-CO activation to a combination of selective Cu(111) facet exposure, partially oxidized surfaces during PE, and the formation of copper-carbonate-hydroxide complex intermediates during the anodic pulses. This work sheds light on the restructuring of oxide-derived copper electrodes and low-overpotential CO formation and highlights the power of the combination of electrochemistry and time-resolved vibrational spectroscopy to elucidate CO2RR mechanisms.
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Operando shell-isolated nanoparticle-enhanced Raman spectroscopy (SHINERS) with on-line mass spectrometry (MS) has been used to investigate the surface species, such as NO, NOH, NO2 , N2 O, and reaction products of the NO reduction reaction with CO and H2 over supported Rh-based catalysts in the form of catalyst extrudates. By correlating surface intermediates and reaction products, new insights in the reaction mechanism could be obtained. Upon applying different reaction conditions (i. e., H2 or CO), the selectivity of the catalytic reaction could be tuned towards the formation of N2 . Furthermore, in the absence of Rh, no reaction products were detected. The importance of the operando SHINERS as a surface-sensitive characterization technique in the field of heterogeneous catalysis provides routes towards a better understanding of catalytic performance.
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The electrocatalytic carbon dioxide (CO2 ) reduction reaction (CO2 RR) into hydrocarbons is a promising approach for greenhouse gas mitigation, but many details of this dynamic reaction remain elusive. Here, time-resolved surface-enhanced Raman spectroscopy (TR-SERS) is employed to successfully monitor the dynamics of CO2 RR intermediates and Cu surfaces with sub-second time resolution. Anodic treatment at 1.55â V vs. RHE and subsequent surface oxide reduction (below -0.4â V vs. RHE) induced roughening of the Cu electrode surface, which resulted in hotspots for TR-SERS, enhanced time resolution (down to ≈0.7â s) and fourfold improved CO2 RR efficiency toward ethylene. With TR-SERS, the initial restructuring of the Cu surface was followed (<7â s), after which a stable surface surrounded by increased local alkalinity was formed. Our measurements revealed that a highly dynamic CO intermediate, with a characteristic vibration below 2060â cm-1 , is related to C-C coupling and ethylene production (-0.9â V vs. RHE), whereas lower cathodic bias (-0.7â V vs. RHE) resulted in gaseous CO production from isolated and static CO surface species with a distinct vibration at 2092â cm-1 .
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UV-curable inks, coatings, and adhesives are being increasingly used in food packaging systems. When exposed to UV energy, UV-photoinitiators (PI's) present in the formulations produce free radicals which catalyze polymerization of monomers and pre-polymers into resins. In addition to photopolymerization, other free radical reactions occur in these systems resulting in the formation of chemically varied photolytic decomposition products, many of which are low molecular weight chemical species with high migration potential. This research conducted model experiments in which 24 commonly used PI's were exposed to UV-energy at the typical upper limit of commercial UV-printing press conditions. UV-irradiated PI's were analyzed by gas chromatography-mass spectrometry (GC-MS) and electrospray-mass spectrometry (ESI-MS) in order to identify photolytic decomposition products. Subsequently, migration studies of 258 UV-cure food packaging samples were conducted using GC-MS; PI's and photolytic decomposition products were found in nearly all samples analyzed. One hundred-thirteen photolytic decomposition products were identified. Eighteen intact PI's and 21 photolytic decomposition products were observed as migrants from the 258 samples analyzed, and these were evaluated for frequency of occurrence and migratory concentration range. The most commonly observed PI's were 2-hydroxy-2-methylpropiophenone and benzophenone. The most commonly observed photolytic decomposition products were 2,4,6-trimethylbenzaldehyde and 1-phenyl-2-butanone. This compilation of PI photolytic decomposition data and associated migration data will aid industry in identifying and tracing non-intentionally added substances (NIAS) in food packaging materials.
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Benzaldeídos/isolamento & purificação , Butanonas/isolamento & purificação , Contaminação de Alimentos/análise , Embalagem de Alimentos , Benzaldeídos/metabolismo , Benzofenonas/química , Butanonas/química , Cromatografia Gasosa-Espectrometria de Massas , Estrutura Molecular , Fotólise , Propiofenonas/química , Espectrometria de Massas por Ionização por Electrospray , Raios UltravioletaRESUMO
Raman spectroscopy is known as a powerful technique for solid catalyst characterization as it provides vibrational fingerprints of (metal) oxides, reactants, and products. It can even become a strong surface-sensitive technique by implementing shell-isolated surface-enhanced Raman spectroscopy (SHINERS). Au@TiO2 and Au@SiO2 shell-isolated nanoparticles (SHINs) of various sizes were therefore prepared for the purpose of studying heterogeneous catalysis and the effect of metal oxide coating. Both SiO2 - and TiO2 -SHINs are effective SHINERS substrates and thermally stable up to 400 °C. Nano-sized Ru and Rh hydrogenation catalysts were assembled over the SHINs by wet impregnation of aqueous RuCl3 and RhCl3 . The substrates were implemented to study CO adsorption and hydrogenation under in situ conditions at various temperatures to illustrate the differences between catalysts and shell materials with SHINERS. This work demonstrates the potential of SHINS for in situ characterization studies in a wide range of catalytic reactions.
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Shell-isolated nanoparticle-enhanced Raman spectroscopy (SHINERS) has proven to be a useful characterization tool for heterogeneous catalysis research. The advantage of SHINERS lies in studying surface reactions on solid catalysts, including the detection of reactants, intermediates and products, in real time. However, due to the extremely strong local electric fields, minor amounts of contaminants can already have a big impact on the quality and interpretation of the spectroscopic data obtained. Often, a large part of the organic fingerprint region (1100-1700â cm-1 ) is omitted from SHINER spectra as this is not the main region of interest. However, we show that bands in this region are an important indication of the cleanliness of the substrate. In this work, we propose robust synthesis and measurement protocols to obtain clean SHINERS substrates amenable for catalysis research. By cleaning the substrates with various heat and oxidation treatments, featureless Raman spectra can be obtained. Furthermore, very pure gas feeds are required and must be obtained by flushing the gas lines and the reaction chamber beforehand and installing a filter for further cleaning the gas feed. Controlling the laser power to limit substrate and sample degradation is also a crucial aspect of proper measurement protocols.
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The linear growth of operators in local quantum systems leads to an effective light cone even if the system is nonrelativistic. We show that the consistency of diffusive transport with this light cone places an upper bound on the diffusivity: Dâ²v^{2}τ_{eq}. The operator growth velocity v defines the light cone, and τ_{eq} is the local equilibration time scale, beyond which the dynamics of conserved densities is diffusive. We verify that the bound is obeyed in various weakly and strongly interacting theories. In holographic models, this bound establishes a relation between the hydrodynamic and leading nonhydrodynamic quasinormal modes of planar black holes. Our bound relates transport data-including the electrical resistivity and the shear viscosity-to the local equilibration time, even in the absence of a quasiparticle description. In this way, the bound sheds light on the observed T-linear resistivity of many unconventional metals, the shear viscosity of the quark-gluon plasma, and the spin transport of unitary fermions.
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Pneumocystis carinii , Pneumonia por Pneumocystis/etiologia , T-Linfocitopenia Idiopática CD4-Positiva/complicações , Contagem de Linfócito CD4 , Humanos , Pulmão/diagnóstico por imagem , Pulmão/microbiologia , Masculino , Pessoa de Meia-Idade , Pneumonia por Pneumocystis/diagnóstico por imagem , Pneumonia por Pneumocystis/microbiologia , Radiografia Torácica , T-Linfocitopenia Idiopática CD4-Positiva/diagnóstico , Tomografia Computadorizada por Raios XRESUMO
PURPOSE: To investigate the prognostic value of quantitative computed tomographic (CT) scoring for the extent of fibrosis or emphysema in the context of a clinical model that includes the gender, age, and physiology ( GAP gender, age, and physiology model) of the patient. MATERIALS AND METHODS: Study cohorts were approved by local institutional review boards, and all patients provided written consent. This was a retrospective cohort study that included 348 patients (246 men, 102 women; mean age, 69 years ± 9) with idiopathic pulmonary fibrosis from two institutions. Fibrosis and emphysema visual scores were independently determined by two radiologists. Models were based on competing risks regression for death and were evaluated by using the C index and reclassification improvement. RESULTS: The CT- GAP gender, age, and physiology model (a modification of the original GAP gender, age, and physiology model that replaces diffusion capacity of carbon monoxide with CT fibrosis score) had accuracy comparable to that of the original GAP gender, age, and physiology model, with a C index of 70.3 (95% confidence interval: 66.4, 74.0); difference in C index compared with the GAP gender, age, and physiology model of -0.4 (95% confidence interval: -2.2, 3.4). The performance of the original GAP gender, age, and physiology model did not change significantly with the simple addition of fibrosis score, with a change in C index of 0.0 (95% confidence interval: -1.8, 0.5) or of emphysema score, with a change in C index of 0.0 [95% confidence interval: -1.3, 0.4]). CONCLUSION: CT fibrosis score can replace diffusion capacity of carbon monoxide test results in a modified GAP gender, age, and physiology model (the CT- GAP gender, age, and physiology model) with comparable performance. This may be a useful alternative model in situations where CT scoring is more reliable and available than diffusion capacity of carbon monoxide.
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Fibrose Pulmonar Idiopática/diagnóstico por imagem , Fibrose Pulmonar Idiopática/mortalidade , Tomografia Computadorizada por Raios X/métodos , Idoso , Algoritmos , Feminino , Humanos , Fibrose Pulmonar Idiopática/cirurgia , Estudos Longitudinais , Transplante de Pulmão/mortalidade , Masculino , Prognóstico , Testes de Função Respiratória , Estudos RetrospectivosRESUMO
Accurate assessment of prognosis in idiopathic pulmonary fibrosis remains elusive due to significant individual radiological and physiological variability. We hypothesised that short-term radiological changes may be predictive of survival. We explored the use of CALIPER (Computer-Aided Lung Informatics for Pathology Evaluation and Rating), a novel software tool developed by the Biomedical Imaging Resource Laboratory at the Mayo Clinic Rochester (Rochester, MN, USA) for the analysis and quantification of parenchymal lung abnormalities on high-resolution computed tomography. We assessed baseline and follow-up (time-points 1 and 2, respectively) high-resolution computed tomography scans in 55 selected idiopathic pulmonary fibrosis patients and correlated CALIPER-quantified measurements with expert radiologists' assessments and clinical outcomes. Findings of interval change (mean 289 days) in volume of reticular densities (hazard ratio 1.91, p=0.006), total volume of interstitial abnormalities (hazard ratio 1.70, p=0.003) and per cent total interstitial abnormalities (hazard ratio 1.52, p=0.017) as quantified by CALIPER were predictive of survival after a median follow-up of 2.4 years. Radiologist interpretation of short-term global interstitial lung disease progression, but not specific radiological features, was also predictive of mortality. These data demonstrate the feasibility of quantifying interval short-term changes on high-resolution computed tomography and their possible use as independent predictors of survival in idiopathic pulmonary fibrosis.
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Fibrose Pulmonar Idiopática/diagnóstico por imagem , Processamento de Imagem Assistida por Computador/métodos , Pulmão/diagnóstico por imagem , Reconhecimento Automatizado de Padrão/métodos , Idoso , Progressão da Doença , Feminino , Humanos , Fibrose Pulmonar Idiopática/mortalidade , Masculino , Prognóstico , Modelos de Riscos Proporcionais , Espirometria , Tomografia Computadorizada por Raios XRESUMO
BACKGROUND: Chronic lymphocytic leukemia (CLL) is the most common type of leukemia in Western countries. Although various patterns of lung involvement with CLL have been reported, data on clinicoradiologic presentation are sparse. METHODS: A computer-assisted search was conducted to identify patients encountered at Mayo Clinic from 1998 to 2022 and had leukemic pulmonary infiltrates (LPI) with CLL demonstrated on lung biopsy. Medical records and chest imaging studies were reviewed to identify clinical and radiologic features. RESULTS: Among 13 patients, median age was 77 years (range: 60-88) and included 10 men (77 %). All patients were known to have CLL with a median duration of 96 months (range: 50-408), and none were on treatment. Most common symptoms were dyspnea (62 %), cough (54 %), and fatigue (46 %); 2 patients (15 %) were asymptomatic. Dominant abnormality on CT consisted of single or multiple nodular/mass-like opacities in 10 patients (77 %), while diffuse centrilobular nodules, pleural mass, and diffuse bronchial wall thickening were each seen in one patient, respectively; intrathoracic lymphadenopathy was present in all. After diagnosis of LPI, treatment for CLL was administered to 7 patients (54 %); 6 patients (86 %) exhibited improvement. During follow-up (median 41 months), 8 (62 %) patients died. Causes of death included progressive CLL or treatment-related complications (2 patients), pneumonia (1 patient), unrelated causes (3 patients), and unknown in 2 patients. CONCLUSIONS: LPI in CLL is generally encountered in patients with known untreated CLL. The main imaging feature is single mass-like opacity or multiple nodular/mass-like opacities, associated with intrathoracic lymphadenopathy.
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Leucemia Linfocítica Crônica de Células B , Linfadenopatia , Pneumonia , Masculino , Humanos , Idoso , Leucemia Linfocítica Crônica de Células B/complicações , Leucemia Linfocítica Crônica de Células B/diagnóstico por imagem , Leucemia Linfocítica Crônica de Células B/patologia , Linfadenopatia/etiologia , Linfadenopatia/complicaçõesRESUMO
BACKGROUND: Although radiologic honeycombing is generally associated with progressive fibrosis and a dismal prognosis, some patients display an unexpectedly indolent clinical course. We aimed to assess for variants of honeycombing associated with a more favorable prognosis. METHODS: A computer-assisted search was conducted to identify patients encountered at Mayo Clinic from 1998 to 2022 who had undergone chest CT that manifested exuberant honeycombing. Medical records and chest imaging studies were reviewed to identify clinical, pulmonary function and radiologic features. RESULTS: Among 136 patients with exuberant honeycombing, 23 patients were identified with CT features of what we termed "bubbly lung" characterized by extensive macrocystic fibrosis; 17 (74%) were female with a median age of 71 years (range, 32-88) at baseline. Underlying diagnoses were ANCA associated vasculitis (22%), overlap CTD (22%), rheumatoid arthritis (17%), IPF (17%), IPAF (9%), systemic sclerosis (4%), undifferentiated CTD (4%), and dermatomyositis (4%). Median FVC was 78% predicted (range 35-112), median DLco was 41% predicted (range 10-92), and median TLC was 73% predicted (range 57-116). Serial FVC measurements were available for 19 (83%) patients with a median interval of 4.7 years (range: 0.4-20); median FVC change per year was 23 ml (range -279 to +232) and median FVC % predicted change per year was 0.00% (range -3.20 to +6.79%). The median survival was 7.1 years, 5-year survival was 76% (95% CI: 58%-100%) and 10-year survival was 48%. CONCLUSIONS: "Bubbly lung" is a variant of exuberant honeycombing that is associated with better-than-expected outcome and FVC decline per year.
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INTRODUCTION: Amyloid transthyretin amyloidosis (ATTR) is characterized by deposition of a misfolded conformation of the transport protein TTR, most commonly in cardiac and nerve tissue, causing clinical disease. Pulmonary amyloidosis, or deposition of ATTR in lung tissue, is a poorly characterized manifestation of this disease. We present the clinical course, imaging characteristics, pathology results, and outcomes of a patient cohort diagnosed with pulmonary ATTR. METHODS: We retrospectively reviewed records of 28 patients with pulmonary ATTR seen at Mayo Clinic from September 30, 2005, through December 31, 2020. Data collected included information on demographics, subjective symptoms, tissue biopsy results, pulmonary function testing, imaging findings, and treatment. RESULTS: Of the patients, 89% were men; the median age was 74.5 years (range, 50-99 years). Patients were typically diagnosed after persistent dyspnea and abnormal chest imaging resulted in lung biopsy, which yielded the ATTR diagnosis. Most patients had a preexisting diagnosis of cardiac ATTR. The disease was wild-type in 62% and hereditary in 38%. Normal pulmonary function tests followed by a restrictive pattern were the most common presentation. Of the patients, 93% had chest computed tomography, with common findings of diffuse nodularity, calcified granulomas, interlobular septal thickening, and pleural effusions. Almost all patients had pulmonary vascular involvement, and half had interstitial involvement on tissue biopsy. One-third received either anti-amyloid pharmacotherapy or a heart transplant. Half of patients had died before the time of study inclusion. CONCLUSION: Pulmonary disease is a less common but clinically important manifestation of ATTR.
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Neuropatias Amiloides Familiares , Pneumopatias , Idoso , Neuropatias Amiloides Familiares/complicações , Neuropatias Amiloides Familiares/diagnóstico por imagem , Humanos , Pulmão/patologia , Pneumopatias/diagnóstico por imagem , Masculino , Estudos RetrospectivosRESUMO
Polyolefin catalysts are characterized by their hierarchically complex nature, which complicates studies on the interplay between the catalyst and formed polymer phases. Here, the missing link in the morphology gap between planar model systems and industrially relevant spherical catalyst particles is introduced through the use of a spherical cap Ziegler-type catalyst model system for the polymerization of ethylene. More specifically, a moisture-stable LaOCl framework with enhanced imaging contrast has been designed to support the TiCl4 pre-active site, which could mimic the behaviour of the highly hygroscopic and industrially used MgCl2 framework. As a function of polymerization time, the fragmentation behaviour of the LaOCl framework changed from a mixture of the shrinking core (i.e., peeling off small polyethylene fragments at the surface) and continuous bisection (i.e., internal cleavage of the framework) into dominantly a continuous bisection model, which is linked to the evolution of the estimated polyethylene volume and the fraction of crystalline polyethylene formed. The combination of the spherical cap model system and the used advanced micro-spectroscopy toolbox, opens the route for high-throughput screening of catalyst functions with industrially relevant morphologies on the nano-scale.
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OBJECTIVE: The aim of this study was to evaluate the clinical impact of a higher spatial resolution, full field-of-view investigational photon-counting detector computed tomography (PCD-CT) on radiologist confidence in imaging findings and diagnosis of usual interstitial pneumonia (UIP) compared with conventional energy-integrating detector CT (EID-CT). MATERIALS AND METHODS: Patients suspected of interstitial lung disease were scanned on a PCD-CT system after informed consent and a clinically indicated EID-CT. In 2 sessions, 3 thoracic radiologists blinded to clinical history and scanner type evaluated CT images of the right and left lungs separately on EID- or PCD-CT, reviewing each lung once/session, rating confidence in imaging findings of reticulation, traction bronchiectasis, honeycombing, ground-glass opacities (GGOs), mosaic pattern, and lower lobe predominance (100-point scale: 0-33, likely absent; 34-66, indeterminate; 67-100, likely present). Radiologists also rated confidence for the probability of UIP (0-20, normal; 21-40, inconsistent with UIP; 41-60, indeterminate UIP; 61-81; probable UIP; 81-100, definite UIP) and graded image quality. Because a confidence scale of 50 represented completely equivocal findings, magnitude score (the absolute value of confidence scores from 50) was used for analysis (higher scores were more confident). Image noise was measured for each modality. The magnitude score was compared using linear mixed effects regression. The consistency of findings and diagnosis between 2 scanners were evaluated using McNemar test and weighted κ statistics, respectively. RESULTS: A total of 30 patients (mean age, 68.8 ± 11.0 years; M:F = 18:12) underwent conventional EID-CT (median CTDI vol , 7.88 mGy) and research PCD-CT (median CTDI vol , 6.49 mGy). The magnitude scores in PCD-CT were significantly higher than EID-CT for imaging findings of reticulation (40.7 vs 38.3; P = 0.023), GGO (34.4 vs 31.7; P = 0.019), and mosaic pattern (38.6 vs 35.9; P = 0.013), but not for other imaging findings ( P ≥ 0.130) or confidence in UIP (34.1 vs 22.2; P < 0.059). Magnitude score of probability of UIP in PCD-CT was significantly higher than EID-CT in one reader (26.0 vs 21.5; P = 0.009). Photon-counting detector CT demonstrated a decreased number of indeterminate GGO (17 vs 26), an increased number of unlikely GGO (74 vs 50), and an increased number of likely reticulations (140 vs 130) relative to EID-CT. Interobserver agreements among 3 readers for imaging findings and probability of UIP were similar between PCD-CT and EID-CT (intraclass coefficient: 0.507-0.818 vs 0.601-0.848). Photon-counting detector CT had higher scores in overall image quality (4.84 ± 0.38) than those in EID-CT (4.02 ± 0.40; P < 0.001) despite increased image noise (mean 85.5 vs 36.1 HU). CONCLUSIONS: Photon-counting detector CT provided better image quality and improved the reader confidence for presence or absence of imaging findings of reticulation, GGO, and mosaic pattern with idiosyncratic improvement in confidence in UIP presence.
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Fibrose Pulmonar Idiopática , Idoso , Humanos , Pulmão/diagnóstico por imagem , Pessoa de Meia-Idade , Imagens de Fantasmas , Fótons , Tomografia Computadorizada por Raios X/métodosRESUMO
Caffeoyl CoA O-methyltransferases (OMTs) have been characterized from numerous plant species and have been demonstrated to be involved in lignin biosynthesis. Higher plant species are known to have additional caffeoyl CoA OMT-like genes, which have not been well characterized. Here, we identified two new caffeoyl CoA OMT-like genes by screening a cDNA library from specialized hair cells of pods of the orchid Vanilla planifolia. Characterization of the corresponding two enzymes, designated Vp-OMT4 and Vp-OMT5, revealed that in vitro both enzymes preferred as a substrate the flavone tricetin, yet their sequences and phylogenetic relationships to other enzymes are distinct from each other. Quantitative analysis of gene expression indicated a dramatic tissue-specific expression pattern for Vp-OMT4, which was highly expressed in the hair cells of the developing pod, the likely location of vanillin biosynthesis. Although Vp-OMT4 had a lower activity with the proposed vanillin precursor, 3,4-dihydroxybenzaldehyde, than with tricetin, the tissue specificity of expression suggests it may be a candidate for an enzyme involved in vanillin biosynthesis. In contrast, the Vp-OMT5 gene was mainly expressed in leaf tissue and only marginally expressed in pod hair cells. Phylogenetic analysis suggests Vp-OMT5 evolved from a cyanobacterial enzyme and it clustered within a clade in which the sequences from eukaryotic species had predicted chloroplast transit peptides. Transient expression of a GFP-fusion in tobacco demonstrated that Vp-OMT5 was localized in the plastids. This is the first flavonoid OMT demonstrated to be targeted to the plastids.
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Metiltransferases/fisiologia , Proteínas de Plantas/fisiologia , Plastídeos/química , Vanilla/química , Sequência de Aminoácidos , Clonagem Molecular , Biblioteca Gênica , Proteínas de Fluorescência Verde/análise , Metiltransferases/análise , Metiltransferases/isolamento & purificação , Dados de Sequência Molecular , Filogenia , Proteínas de Plantas/análise , Proteínas de Plantas/isolamento & purificação , Alinhamento de SequênciaRESUMO
OBJECTIVE: The purpose of this study was to retrospectively evaluate appropriate and inappropriate application of nodule management guidelines in radiology reports of pulmonary nodules seen at CT. MATERIALS AND METHODS: The CT reports of 181 patients examined in July and August 2007 (94 males, 87 females; age range, 2-88 years; mean, 60.3 ± 13.0 years) and 177 patients examined in March 2009 (106 men, 71 women; age range, 24-91 years; mean, 60.7 ± 14.0 years) were retrospectively reviewed to assess whether nodule management guidelines were inappropriately applied. The exclusion criteria for the 2007 cases included multiple nodules, stable nodules, potential metastatic disease, probable infectious or inflammatory cause, and age younger than 35 years. The exclusion criteria for the 2009 cases were all of the 2007 criteria except multiple nodules. RESULTS: Guidelines were inappropriately applied 105 times in 2007 and 25 times in 2009. Reasons for inappropriate use in 2007 were multiple nodules in 70 of the 105 cases (67%), potential metastatic disease in 25 cases (24%), age younger than 35 years in four cases (4%), stable nodules in two cases (2%), probable infectious or inflammatory cause in two cases (2%), and protocol not included despite absence of exclusion criteria in two cases (2%). The reasons in 2009 were potential metastatic disease in 15 of the 25 cases (60%), age younger than 35 years in four cases (16%), stable nodules in three cases (12%), probable infectious or inflammatory cause in one case (4%), and protocol not included despite absence of exclusion criteria in two cases (8%). The percentage of cases with at least one error was 48.1% in 2007, significantly higher than the 13.6% in 2009 (p < 0.001). CONCLUSION: Inappropriate application of guidelines for management of pulmonary nodules seen at CT was significantly reduced by removing multiple nodules from the exclusion criteria. Otherwise, causes for inappropriate application remained stable.