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1.
Environ Toxicol Chem ; 2024 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-38695731

RESUMO

Microplastic pollution threatens some of the world's most iconic locations for marine biodiversity, including the remote Galápagos Islands, Ecuador. Using the Galápagos penguin (Spheniscus mendiculus) as a sentinel species, the present study assessed microplastics and suspected anthropogenic cellulose concentrations in surface seawater and zooplankton near Santa Cruz and Galápagos penguin colonies (Floreana, Isabela, Santiago), as well as in penguin potential prey (anchovies, mullets, milkfish) and penguin scat. On average, 0.40 ± 0.32 microplastics L-1 were found in surface seawater (<10 µm; n = 63 L), while 0.003, 0.27, and 5.12 microplastics individual-1 were found in zooplankton (n = 3372), anchovies (n = 11), and mullets (n = 6), respectively. The highest concentration (27 microplastics individual-1) was observed in a single milkfish. Calculations based on microplastics per gram of prey, in a potential diet composition scenario, suggest that the Galápagos penguin may consume 2881 to 9602 microplastics daily from prey. Despite this, no microplastics or cellulose were identified in 3.40 g of guano collected from two penguins. Our study confirms microplastic exposure in the pelagic food web and endangered penguin species within the UNESCO World Heritage site Galápagos Islands, which can be used to inform regional and international policies to mitigate plastic pollution and conserve biodiversity in the global ocean. Environ Toxicol Chem 2024;00:1-16. © 2024 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

2.
ACS Nano ; 18(15): 10388-10396, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38567867

RESUMO

Interferometric scattering microscopy (iSCAT) has rapidly developed as a quantitative tool for the label-free detection of single macromolecules and nanoparticles. In practice, this measurement records the interferometric scattering signal of individual nanoparticles in solution as they land and stick on a coverslip, exhibiting an intensity that varies linearly with particle volume and an adsorption rate that reflects the solution-phase transport kinetics of the system. Together, such measurements provide a multidimensional gauge of the particle size and concentration in solution over time. However, the landing kinetics of particles in solution also manifest a measurement frequency limitation imposed by the slow long-range mobility of particle diffusion to the measurement interface. Here we introduce an effective means to overcome the inherent diffusion-controlled sampling limitation of spontaneous mass photometry. We term this methodology electrophoretic deposition interferometric scattering microscopy (EPD-iSCAT). This approach uses a coverslip supporting a conductive thin film of indium tin oxide (ITO). Charging this ITO film to a potential of around +1 V electrophoretically draws charged nanoparticles from solution and binds them in the focal plane of the microscope. Regulating this potential offers a direct means of controlling particle deposition. Thus, we find for a 0.1 nM solution of 50 nm polystyrene nanoparticles that the application of +1 V to an EPD-iSCAT coverslip assembly drives an electrophoretic deposition rate constant of 1.7 s-1 µm-2 nM-1. Removal of the potential causes deposition to cease. This user control of EPD-iSCAT affords a means to apply single-molecule mass photometry to monitor long-term changes in solution, owing to slow kinetic processes. In contrast with conventional coverslips chemically derivatized with charged thin films, EPD-iSCAT maintains a deposition rate that varies linearly with the bulk concentration.

3.
HEC Forum ; 2024 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-38652193

RESUMO

Clinical Ethics Consultation (CEC) has grown significantly in the last decade, and efforts are being made to professionalize the practice. The American Society for Bioethics and Humanities (ASBH) has been instrumental in this process, having published the Code of Ethics and Professional Responsibilities for Healthcare Ethics Consultants and founded and endorsed the creation of the Healthcare Ethics Consultant Certified (HCEC) Certification Commission. The ASBH also published "core competencies" for healthcare ethics consultants and has delineated a clear identity and role of such consultants distinct from that other healthcare professionals. In addition, more enter the field armed with advanced degrees (MA and PhD) or certification in clinical ethics consultation. While some have questioned the trend toward professionalization, the momentum is clearly in its favor. This paper explores three questions: Does the professionalization of healthcare ethics consultation expose those engaged in the field to the types of liability claims faced by professionals in other fields? What specific liabilities could affect a healthcare ethics consultant? And finally, what should healthcare ethics consultants do to protect themselves against liability claims? We conclude that while the risk of liability remains low, those engaged in the field should accept that risk just as part of their status as professionals and, like those in allied professions, seek appropriate protection in the form of liability insurance.

4.
Radiology ; 310(1): e233281, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38259213

Assuntos
Biópsia , Humanos
5.
PNAS Nexus ; 2(11): pgad327, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37937270

RESUMO

One in 10 cases of sudden cardiac death strikes without warning as the result of an inherited arrhythmic cardiomyopathy, such as Brugada Syndrome (BrS). Normal physiological variations often obscure visible signs of this and related life-threatening channelopathies in conventional electrocardiograms (ECGs). Sodium channel blockers can reveal previously hidden diagnostic ECG features, however, their use carries the risk of life-threatening proarrhythmic side effects. The absence of a nonintrusive test places a grossly underestimated fraction of the population at risk of SCD. Here, we present a machine-learning algorithm that extracts, aligns, and classifies ECG waveforms for the presence of BrS. This protocol, which succeeds without the use of a sodium channel blocker (88.4% accuracy, 0.934 AUC in validation), can aid clinicians in identifying the presence of this potentially life-threatening heart disease.

6.
Radiology ; 309(1): e231481, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37906014

RESUMO

Multiple US-based systems for risk stratification of thyroid nodules are in use worldwide. Unfortunately, the malignancy probability assigned to a nodule varies, and terms and definitions are not consistent, leading to confusion and making it challenging to compare study results and craft revisions. Consistent application of these systems is further hampered by interobserver variability in identifying the sonographic features on which they are founded. In 2018, an international multidisciplinary group of 19 physicians with expertise in thyroid sonography (termed the International Thyroid Nodule Ultrasound Working Group) was convened with the goal of developing an international system, tentatively called the International Thyroid Imaging Reporting and Data System, or I-TIRADS, in two phases: (phase I) creation of a lexicon and atlas of US descriptors of thyroid nodules and (phase II) development of a system that estimates the malignancy risk of a thyroid nodule. This article presents the methods and results of phase I. The purpose herein is to show what has been accomplished thus far, as well as generate interest in and support for this effort in the global thyroid community.


Assuntos
Neoplasias da Glândula Tireoide , Nódulo da Glândula Tireoide , Humanos , Nódulo da Glândula Tireoide/diagnóstico por imagem , Nódulo da Glândula Tireoide/patologia , Consenso , Medição de Risco , Ultrassonografia/métodos , Neoplasias da Glândula Tireoide/patologia , Estudos Retrospectivos
7.
Anal Chem ; 95(43): 15908-15916, 2023 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-37698955

RESUMO

Important decisions in local agricultural policy and practice often hinge on the soil's chemical composition. Raman spectroscopy offers a rapid noninvasive means to quantify the constituents of complex organic systems. But the application of Raman spectroscopy to soils presents a multifaceted challenge due to organic/mineral compositional complexity and spectral interference arising from overwhelming fluorescence. The present work compares methodologies with the capacity to help overcome common obstacles that arise in the analysis of soils. We created conditions representative of these challenges by combining varying proportions of six amino acids commonly found in soils with fluorescent bentonite clay and coarse mineral components. Referring to an extensive data set of Raman spectra, we compare the performance of the convolutional neural network (CNN) and partial least-squares regression (PLSR) multivariate models for amino acid composition. Strategies employing volume-averaged spectral sampling and data preprocessing algorithms improve the predictive power of these models. Our average test R2 for PLSR models exceeds 0.89 and approaches 0.98, depending on the complexity of the matrix, whereas CNN yields an R2 range from 0.91 to 0.97, demonstrating that classic PLSR and CNN perform comparably, except in cases where the signal-to-noise ratio of the organic component is very low, whereupon CNN models outperform. Artificially isolating two of the most prevalent obstacles in evaluating the Raman spectra of soils, we have characterized the effect of each obstacle on the performance of machine learning models in the absence of other complexities. These results highlight important considerations and modeling strategies necessary to improve the Raman analysis of organic compounds in complex mixtures in the presence of mineral spectral components and significant fluorescence.

9.
J Digit Imaging ; 36(6): 2392-2401, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37580483

RESUMO

Thyroid nodules occur in up to 68% of people, 95% of which are benign. Of the 5% of malignant nodules, many would not result in symptoms or death, yet 600,000 FNAs are still performed annually, with a PPV of 5-7% (up to 30%). Artificial intelligence (AI) systems have the capacity to improve diagnostic accuracy and workflow efficiency when integrated into clinical decision pathways. Previous studies have evaluated AI systems against physicians, whereas we aim to compare the benefits of incorporating AI into their final diagnostic decision. This work analyzed the potential for artificial intelligence (AI)-based decision support systems to improve physician accuracy, variability, and efficiency. The decision support system (DSS) assessed was Koios DS, which provides automated sonographic nodule descriptor predictions and a direct cancer risk assessment aligned to ACR TI-RADS. The study was conducted retrospectively between (08/2020) and (10/2020). The set of cases used included 650 patients (21% male, 79% female) of age 53 ± 15. Fifteen physicians assessed each of the cases in the set, both unassisted and aided by the DSS. The order of the reading condition was randomized, and reading blocks were separated by a period of 4 weeks. The system's impact on reader accuracy was measured by comparing the area under the ROC curve (AUC), sensitivity, and specificity of readers with and without the DSS with FNA as ground truth. The impact on reader variability was evaluated using Pearson's correlation coefficient. The impact on efficiency was determined by comparing the average time per read. There was a statistically significant increase in average AUC of 0.083 [0.066, 0.099] and an increase in sensitivity and specificity of 8.4% [5.4%, 11.3%] and 14% [12.5%, 15.5%], respectively, when aided by Koios DS. The average time per case decreased by 23.6% (p = 0.00017), and the observed Pearson's correlation coefficient increased from r = 0.622 to r = 0.876 when aided by Koios DS. These results indicate that providing physicians with automated clinical decision support significantly improved diagnostic accuracy, as measured by AUC, sensitivity, and specificity, and reduced inter-reader variability and interpretation times.


Assuntos
Aprendizado Profundo , Nódulo da Glândula Tireoide , Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Idoso , Estudos Retrospectivos , Inteligência Artificial , Nódulo da Glândula Tireoide/patologia , Ultrassonografia/métodos
11.
AIDS ; 37(7): 1057-1064, 2023 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-36927740

RESUMO

OBJECTIVE: To evaluate the safety and efficacy of switching highly treatment-experienced people with HIV (HTE PWH) from rilpivirine/emtricitabine/tenofovir alafenamide (RPV/FTC/TAF) plus dolutegravir (DTG) to bictegravir/emtricitabine/tenofovir alafenamide (BIC/FTC/TAF) plus doravirine (DOR). A pharmacokinetic (PK) analysis was conducted to assess the potential interaction between BIC and DOR. DESIGN AND METHODS: This open-label switch trial enrolled HTE PWH from a primary care private practice in the United States. Eligible participants were male, aged ≥45 years, with documented viral resistance to protease inhibitors, nucleoside reverse transcriptase inhibitors, and/or nonnucleoside reverse transcriptase inhibitors but no resistance to RPV or DOR, and no K65R or T69 insertion mutations. Virologic suppression (≤50 copies/ml) while on RPV/FTC/TAF plus DTG for ≥6 months was required prior to enrollment. The primary endpoint of the study was virologic suppression (<50 and <200 copies/ml) at 48 weeks. Secondary endpoints included safety, tolerability, changes in body mass index (BMI), and identification of PK parameters of BIC and DOR. RESULTS: Twenty males [median age: 65 years (range, 46-74), median time since HIV diagnosis: 37 years (range, 12-42)] completed the study. BIC/FTC/TAF plus DOR was well tolerated with no serious or treatment-related adverse events reported and no appreciable changes in BMI from baseline to Week 48. At Week 48, 100% of participants had <50 viral copies/ml. PK parameters for BIC and DOR ( n  = 10) were consistent with published data. CONCLUSIONS: Switching from RPV/FTC/TAF plus DTG to BIC/FTC/TAF plus DOR was well tolerated and efficacious in HTE men aged ≥45 years with HIV.


Assuntos
Fármacos Anti-HIV , Infecções por HIV , Idoso , Feminino , Humanos , Masculino , Fármacos Anti-HIV/uso terapêutico , Combinação de Medicamentos , Emtricitabina , Compostos Heterocíclicos com 3 Anéis , Infecções por HIV/tratamento farmacológico , Piridonas/uso terapêutico , Inibidores da Transcriptase Reversa/uso terapêutico
12.
J Am Chem Soc ; 145(8): 4414-4420, 2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36799452

RESUMO

Here, we detail how the catalytic behavior of immobilized molecular electrocatalysts for the CO2 reduction reaction (CO2RR) can be impacted by catalyst aggregation. Operando Raman spectroscopy was used to study the CO2RR mediated by a layer of cobalt phthalocyanine (CoPc) immobilized on the cathode of an electrochemical flow reactor. We demonstrate that during electrolysis, the oxidation state of CoPc in the catalyst layer is dependent upon the degree of catalyst aggregation. Our data indicate that immobilized molecular catalysts must be dispersed on conductive supports to mitigate the formation of aggregates and produce meaningful performance data. We leveraged insights from this mechanistic study to engineer an improved CO-forming immobilized molecular catalyst─cobalt octaethoxyphthalocyanine (EtO8-CoPc)─that exhibited high selectivity (FECO ≥ 95%), high partial current density (JCO ≥ 300 mA/cm2), and high durability (ΔFECO < 0.1%/h at 150 mA/cm2) in a flow cell. This work demonstrates how to accurately identify CO2RR active species of molecular catalysts using operando Raman spectroscopy and how to use this information to implement improved molecular electrocatalysts into flow cells. This work also shows that the active site of CoPc during CO2RR catalysis in a flow cell is the metal center.

13.
Europace ; 25(3): 948-955, 2023 03 30.
Artigo em Inglês | MEDLINE | ID: mdl-36610790

RESUMO

AIMS: The long-QT syndrome (LQTS) represents a leading cause of sudden cardiac death (SCD). The aim of this study was to assess the presence of an underlying electroanatomical arrhythmogenic substrate in high-risk LQTS patients. METHODS AND RESULTS: The present study enrolled 11 consecutive LQTS patients who had experienced frequent implantable cardioverter-defibrillator (ICD discharges triggered by ventricular fibrillation (VF). We acquired electroanatomical biventricular maps of both endo and epicardial regions for all patients and analyzed electrograms sampled from several myocardial regions. Abnormal electrical activities were targeted and eliminated by the means of radiofrequency catheter ablation. VF episodes caused a median of four ICD discharges in eleven patients (6 male, 54.5%; mean age 44.0 ± 7.8 years, range 22-53) prior to our mapping and ablation procedures. The average QTc interval was 500.0 ± 30.2 ms. Endo-epicardial biventricular maps displayed abnormally fragmented, low-voltage (0.9 ± 0.2 mV) and prolonged electrograms (89.9 ± 24.1 ms) exclusively localized in the right ventricular epicardium. We found electrical abnormalities extending over a mean epicardial area of 15.7 ± 3.1 cm2. Catheter ablation of the abnormal epicardial area completely suppressed malignant arrhythmias over a mean 12 months of follow-up (median VF episodes before vs. after ablation, 4 vs. 0; P = 0.003). After the procedure, the QTc interval measured in a 12-lead ECG analysis shortened to a mean of 461.8 ± 23.6 ms (P = 0.004). CONCLUSION: This study reveals that, among high-risk LQTS patients, regions localized in the epicardium of the right ventricle harbour structural electrophysiological abnormalities. Elimination of these abnormal electrical activities successfully prevented malignant ventricular arrhythmia recurrences.


Assuntos
Ablação por Cateter , Síndrome do QT Longo , Taquicardia Ventricular , Humanos , Masculino , Adulto Jovem , Adulto , Pessoa de Meia-Idade , Resultado do Tratamento , Técnicas Eletrofisiológicas Cardíacas/métodos , Fibrilação Ventricular/diagnóstico , Fibrilação Ventricular/etiologia , Fibrilação Ventricular/terapia , Eletrocardiografia/métodos , Morte Súbita Cardíaca/etiologia , Morte Súbita Cardíaca/prevenção & controle , Síndrome do QT Longo/complicações , Ablação por Cateter/efeitos adversos , Ablação por Cateter/métodos
15.
Wounds ; 35(12): E414-E419, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-38277629

RESUMO

BACKGROUND: Most chronic wounds contain biofilm, and debridement remains the centerpiece of treatment. Enzymatic debridement is an effective tool in removing nonviable tissue, however, there is little evidence supporting its effect on planktonic and biofilm bacteria. OBJECTIVE: This study evaluated the effects of a novel BBD agent on removal of nonviable tissue, biofilm, and microbial loads in patients with chronic ulcers. MATERIALS AND METHODS: Twelve patients with DFU or VLU were treated with up to 8 once-daily applications of BBD and then followed for an additional 2 weeks. Punch biopsy specimens were collected and analyzed for biofilm, and fluorescence imaging was used to measure bacterial load. RESULTS: Ten patients completed treatment, and 7 achieved complete debridement within a median of 2 applications (range, 2-8). By the end of the 2-week follow-up period, the mean ± SD reduction in wound area was 35% ± 38. In all 6 patients who were positive for biofilm at baseline, the biofilm was reduced to single individual or no detected microorganisms by the end of treatment. Red fluorescence for Staphylococcus aureus decreased from a mean of 1.09 cm² ± 0.58 before treatment to 0.39 cm² ± 0.25 after treatment. BBD was safe and well tolerated. CONCLUSION: Preliminary data suggest that BBD is safe and that it can be used to effectively debride DFU and VLU, reduce biofilm and planktonic bacterial load, and promote reduction in wound size.


Assuntos
Diabetes Mellitus , Pé Diabético , Humanos , Biofilmes , Bromelaínas/farmacologia , Bromelaínas/uso terapêutico , Desbridamento/métodos , Pé Diabético/terapia , Cicatrização , Estudo de Prova de Conceito
16.
Environ Adv ; 92022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36507367

RESUMO

Background: Perfluoroalkyl substances (PFAS) are ubiquitous synthetic chemicals with long half-lives and are known to cross the placenta during pregnancy. We examined the influence of maternal PFAS levels on in utero fetal growth trajectories and assessed whether maternal stress modified these associations. Methods: Blood serum concentrations of five PFAS (PFOS, PFHxS, PFNA, PFOA, PFDA) were measured in 335 prenatal specimens (mean gestational age (GA): 21±9 weeks) in the MADRES cohort. Fetal growth outcomes (head circumference (HC), abdominal circumference (AC), biparietal diameter (BPD), femur length (FL), and estimated fetal weight (EFW)) were abstracted from ultrasound medical records and measured at the 3rd trimester study visit (N = 833 scans, GA range 10-42 weeks, mean 2.4 scans/participant). Adjusted linear mixed models with a GA quadratic growth curve were used for each PFAS exposure and growth outcome. PFOS and PFHxS were modeled continuously (100% sample detection), while PFOA, PFNA, and PFDA were modeled categorically (57-70% sample detection). Scores on the Perceived Stress Scale (PSS) measured in pregnancy were dichotomized at the median (<13 vs. ≥ 13) in stratified models. Results: Participants were on average 29±6 years old and predominately Hispanic (76%). Median serum concentrations of PFOS, PFHxS, PFNA, PFOA and PFDA were 1.34, 1.10, 0.07, 0.12, and 0.04 ng/mL, respectively. Participants with detected PFOA concentrations had fetuses with -2.5 mm (95% CI -4.2, -0.8) smaller HC and-0.7 mm (95% CI -1.3, -0.2) smaller BPD on average for a fixed GA than those without detected PFOA concentrations. In models stratified by PSS level, the effects of PFOA on fetal growth parameters were stronger and only significant in participants with higher stress levels (HC: ß= -3.5, 95% CI -5.8, -1.4; BPD: ß = -0.8, 95% CI -1.6, -1.1). Conclusions: Prenatal PFOA exposure adversely impacted fetal head biometric parameters in participants experiencing higher stress during pregnancy.

17.
Environ Health ; 21(1): 115, 2022 11 26.
Artigo em Inglês | MEDLINE | ID: mdl-36434705

RESUMO

BACKGROUND: It is well documented that persons of color experience disproportionate exposure to environmental contaminants, including air pollution, and have poorer pregnancy outcomes. This study assessed the critical windows of exposure to ambient air pollution on in utero fetal growth among structurally marginalized populations in urban Los Angeles. METHODS: Participants (N = 281) from the larger ongoing MADRES pregnancy cohort study were included in this analysis. Fetal growth outcomes were measured on average at 32 [Formula: see text] 2 weeks of gestation by a certified sonographer and included estimated fetal weight, abdominal circumference, head circumference, biparietal diameter and femur length. Daily ambient air pollutant concentrations were estimated for four pollutants (particulate matter less than 2.5 µm (PM2.5) and less than 10 µm (PM10) in aerodynamic diameter, nitrogen dioxide (NO2), and 8-h maximum ozone (O3)) at participant residences using inverse-distance squared spatial interpolation from ambient monitoring data. Weekly gestational averages were calculated from 12 weeks prior to conception to 32 weeks of gestation (44 total weeks), and their associations with growth outcomes were modeled using adjusted distributed lag models (DLMs). RESULTS: Participants were on average 29 years [Formula: see text] 6 old and predominately Hispanic (82%). We identified a significant sensitive window of PM2.5 exposure (per IQR increase of 6 [Formula: see text]3) between gestational weeks 4-16 for lower estimated fetal weight [Formula: see text] averaged4-16 = -8.7 g; 95% CI -16.7, -0.8). Exposure to PM2.5 during gestational weeks 1-23 was also significantly associated with smaller fetal abdominal circumference ([Formula: see text] averaged1-23 = -0.6 mm; 95% CI -1.1, -0.2). Additionally, prenatal exposure to PM10 (per IQR increase of 13 [Formula: see text]3) between weeks 6-15 of pregnancy was significantly associated with smaller fetal abdominal circumference ([Formula: see text] averaged6-15 = -0.4 mm; 95% CI -0.8, -0.1). DISCUSSION: These results suggest that exposure to particulate matter in early to mid-pregnancy, but not preconception or late pregnancy, may have critical implications on fetal growth.


Assuntos
Poluição do Ar , Peso Fetal , Feminino , Humanos , Gravidez , Estudos de Coortes , Exposição Ambiental/efeitos adversos , Exposição Ambiental/análise , Poluição do Ar/efeitos adversos , Poluição do Ar/análise , Material Particulado/efeitos adversos , Material Particulado/análise , Desenvolvimento Fetal , Hispânico ou Latino
18.
Phys Rev Lett ; 129(12): 123002, 2022 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-36179157

RESUMO

Air lasing from single ionized N_{2}^{+} molecules induced by laser filamentation in air has been intensively investigated and the mechanisms responsible for lasing are currently highly debated. We use ultrafast nitrogen K-edge spectroscopy to follow the strong field ionization and fragmentation dynamics of N_{2} upon interaction with an ultrashort 800 nm laser pulse. Using probe pulses generated by extreme high-order harmonic generation, we observe transitions indicative of the formation of the electronic ground X^{2}Σ_{g}^{+}, first excited A^{2}Π_{u}, and second excited B^{2}Σ_{u}^{+} states of N_{2}^{+} on femtosecond timescales, from which we can quantitatively determine the time-dependent electronic state population distribution dynamics of N_{2}^{+}. Our results show a remarkably low population of the A^{2}Π_{u} state, and nearly equal populations of the X^{2}Σ_{g}^{+} and B^{2}Σ_{u}^{+} states. In addition, we observe fragmentation of N_{2}^{+} into N and N^{+} on a timescale of several tens of picoseconds that we assign to significant collisional dynamics in the plasma, resulting in dissociative excitation of N_{2}^{+}.

19.
Chemistry ; 28(25): e202200340, 2022 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-35344228

RESUMO

Electrochemical reactors that electrolytically convert CO2 into higher-value chemicals and fuels often pass a concentrated hydroxide electrolyte across the cathode. This strongly alkaline medium converts the majority of CO2 into unreactive HCO3 - and CO3 2- byproducts rather than into CO2 reduction reaction (CO2RR) products. The electrolysis of CO (instead of CO2 ) does not suffer from this undesirable reaction chemistry because CO does not react with OH- . Moreover, CO can be more readily reduced into products containing two or more carbon atoms (i. e., C2+ products) compared to CO2 . We demonstrate here that an electrocatalyst layer derived from copper phthalocyanine (CuPc) mediates this conversion effectively in a flow cell. This catalyst achieved a 25 % higher selectivity for acetate formation at 200 mA/cm2 than a known state-of-art oxide-derived Cu catalyst tested in the same flow cell. A gas diffusion electrode coated with CuPc electrolyzed CO into C2+ products at high rates of product formation (i. e., current densities ≥200 mA/cm2 ), and at high faradaic efficiencies for C2+ production (FEC2+ ; >70 % at 200 mA/cm2 ). While operando Raman spectroscopy did not reveal evidence of structural changes to the copper molecular complex, X-ray photoelectron spectroscopy suggests that the catalyst undergoes conversion to a metallic copper species during catalysis. Notwithstanding, the ligand environment about the metal still impacts catalysis, which we demonstrated through the study of a homologous CuPc bearing ethoxy substituents. These findings reveal new strategies for using metal complexes for the formation of carbon-neutral chemicals and fuels at industrially relevant conditions.

20.
J Ultrasound Med ; 41(9): 2295-2306, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34918364

RESUMO

OBJECTIVES: To investigate the accuracy, sensitivity, and specificity of contrast-enhanced ultrasound (CEUS) for detection of parathyroid adenomas and compare it to those of 4-dimensional computed tomography (4DCT), which has been established as a reliable, effective tool for preoperative localization of parathyroid adenomas. METHODS: About 27 patients with suspected parathyroid pathology underwent imaging evaluations with 4DCT and CEUS and 22 patients subsequently underwent surgical resection of parathyroid lesions. 4DCT and CEUS were performed and interpreted by consensus of two expert radiologists with extensive experience in each modality. Assessment for the side, z-axis (craniocaudal axis), and quadrant of the pathologically proven lesion was performed based on the surgical report. RESULTS: For single-gland disease, the accuracy for CEUS localization to the correct quadrant and side were 81.0 and 90.1% respectively. For single-gland disease, the accuracy for 4DCT localization to the correct quadrant and side were 81.0 and 90.5% respectively. 4DCT localization sensitivity and specificity were comparable to those for CEUS. 4DCT allowed for accurate diagnosis in multigland disease in contradistinction to CEUS. CONCLUSIONS: CEUS is a noninvasive, real-time imaging technique that has relatively high diagnostic confidence and accuracy of localization which are comparable to the accuracy of 4DCT for preoperative parathyroid adenoma detection, characterization, and localization. This technique should be considered for primary preoperative diagnosis, especially in younger patients.


Assuntos
Adenoma , Hiperparatireoidismo Primário , Neoplasias das Paratireoides , Adenoma/diagnóstico por imagem , Adenoma/cirurgia , Tomografia Computadorizada Quadridimensional/métodos , Humanos , Glândulas Paratireoides/diagnóstico por imagem , Neoplasias das Paratireoides/diagnóstico por imagem , Neoplasias das Paratireoides/cirurgia , Sensibilidade e Especificidade , Ultrassonografia/métodos
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