Rhodium-Catalyzed Arene Alkenylation: Selectivity and Reaction Mechanism as a Function of In Situ Oxidant Identity.

Rhodium catalyzed arene alkenylation reactions with arenes and olefins using dioxygen as the direct oxidant (e.g., ACS Catal. 2020, 10, 11519), Cu(II) carboxylates (e.g., Science 2015, 348, 421; J. Am. Chem. Soc. 2017, 139, 5474) or Fe(III) carboxylate clusters (e.g., ACS Catal. 2024, 14, 10295), in the presence or absence of dioxygen, have been reported. These processes involve heating catalyst precursor [(η2-C2H4)2Rh(µ-OAc)]2, olefin, arene, and oxidant at temperatures between 120 and 200 °C. Herein, we report comparative studies of Rh-catalyzed arene alkenylation as a function of oxidant identity. This work includes comparisons of catalysis using Cu(II) carboxylates in the presence and absence of dioxygen, catalysis with only dioxygen as the oxidant, and Fe(III) carboxylates in the presence and absence of dioxygen. We report studies of catalysis with each oxidant including reagent concentration dependencies and kinetic isotope effect experiments using C6H6 or C6D6 and protio- or deutero carboxylic acid. Additionally, we probe ortho/meta/para regioselectivity for reactions of ethylene with monosubstituted arenes and Markovnikov/anti-Markovnikov selectivity with monosubstituted olefins. These studies indicate that the variation of oxidant identity impacts catalyst speciation, the reaction mechanism, and the reaction rate. Consequently, distinct Markovnikov/anti-Markovnikov and ortho/meta/para selectivities are observed for catalysis with each oxidant.

Unraveling the Origin of the Repulsive Interaction between Hydrogen Adsorbates on Platinum Single-Crystal Electrodes.

Hydrogen adsorption on platinum (Pt) single-crystal electrodes has been studied intensively in both experiments and computations. Yet, the precise origin and nature of the repulsive interactions observed between hydrogen adsorbates (Hads) have remained elusive. Here, we use first-principles density functional theory calculations to investigate in detail the interactions between Hads on Pt(111), Pt(100), and Pt(110) surfaces. The repulsive interaction between Hads on Pt(111) is deconvoluted into three different physical contributions, namely, (i) electrostatic interactions, (ii) surface distortion effect, and (iii) surface coordination effect. The long-range electrostatic interaction, which is generally considered the most important source of repulsive interactions in surface adsorption, was found to contribute less than 30% of the overall repulsive interaction. The remaining >70% arises from the other two contributions, underscoring the critical influence of surface-mediated interactions on the adsorption process. Surface distortion and coordination effects are found to strongly depend on the coverage and adsorption geometry: the effect of surface distortion dominates when adsorbates reside two or more Pt atoms apart; the effect of surface coordination dominates if hydrogen is adsorbed on neighboring adsorption sites. The above effects are considerably less pronounced on Pt(100) and Pt(110), therefore resulting in weaker interactions between Hads on these two surfaces. Overall, the study highlights the relevance of surface-mediated effects on adsorbate-adsorbate interactions, such as the often-overlooked surface distortion. The effect of these interactions on the hotly debated adsorption site for the adsorbed hydrogen intermediate in the hydrogen evolution reaction is also discussed.

No Money No Time Culinary Nutrition Website eHealth Challenge: A Pre-Post Evaluation of Impact on Diet Quality, Food Expenditure, and Engagement.

No Money No Time (NMNT) is a culinary nutrition website designed to optimize diet quality. The primary aim was to evaluate the impact of an online targeted nutrition challenge email campaign that encouraged engagement with NMNT and goal setting to improve diet quality and weekly food expenditure. A secondary aim was to assess NMNT engagement. Australian adults ≥18 years were recruited to the eHealth nutrition challenge delivered via weekly emails. Diet quality was assessed using the Healthy Eating Quiz (HEQ) diet quality tool. Engagement was assessed using email open and click-through rates. Intention-to-treat (ITT) analysis was conducted using mixed effects linear regression. Of 481 adults (49.7 ± 13.9 years, 84% female) who enrolled 79 (16%) completed the challenge. ITT results indicated statistically significant 6-week increases in diet quality score (+3.8 points p ≤ 0.001, d = 0.58) with sub-scale improvements in vegetables (+0.9 points, p = 0.01, d = 0.32), fruit (+1.2 points, p ≤ 0.001, d = 0.55), and dairy (+0.9 points, p ≤ 0.001, d = 0.58). There were significant post-challenge reductions in household spending on takeaway/snacks/coffee of AUD 8.9 per week (p = 0.01, d = 0.29), body weight reduction (-0.6 kg, p = 0.03, d = 0.26), and BMI (-0.2 kg/m2p = 0.02, d = 0.28). The email open rate remained constant at around 67% (56% to 75%), with an average click-through rate of 18% (7.1% to 37.9%). The eHealth nutrition challenge significantly improved diet quality while reducing BMI and money spent on discretionary foods. Strategies to scale the challenge should be tested as an innovative population strategy for improving diet quality, health indicators, and managing household food budgets.

Association of Serum Endocannabinoid Levels with Pancreatitis and Pancreatitis-Related Pain.

Background and Aims: This investigation examined the association of pancreatitis and pancreatitis-related pain with serum levels of two endocannabinoid molecules such as anandamide (AEA) and 2-arachidonoylglycerol (2-AG) and two paracannabinoid molecules such as oleoylethanolamide (OEA) and palmitoylethanolamide (PEA). Methods: A case-control study was conducted within the Prospective Evaluation of Chronic Pancreatitis for Epidemiological and Translational Studies, including participants with no pancreas disease (N = 56), chronic abdominal pain of suspected pancreatic origin or indeterminate chronic pancreatitis (CP) (N = 22), acute pancreatitis (N = 33), recurrent acute pancreatitis (N = 57), and definite CP (N = 63). Results: Circulating AEA concentrations were higher in women than in men (p = 0.0499), and PEA concentrations were higher in obese participants than those who were underweight/normal or overweight (p = 0.003). Asymptomatic controls with no pancreatic disease had significantly (p = 0.03) lower concentrations of AEA compared with all disease groups combined. The highest concentrations of AEA were observed in participants with acute pancreatitis, followed by those with recurrent acute pancreatitis, chronic abdominal pain/indeterminant CP, and definite CP. Participants with pancreatitis reporting abdominal pain in the past year had significantly (p = 0.04) higher concentrations of AEA compared with asymptomatic controls. Levels of 2-AG were significantly lower (p = 0.02) among participants reporting abdominal pain in the past week, and pain intensity was inversely associated with concentrations of 2-AG and OEA. Conclusions: Endocannabinoid levels may be associated with stage of pancreatitis, perhaps through activation of the CB1 receptor. Validation of our findings would support the investigation of novel therapeutics, including cannabinoid receptor-1 antagonists, in this patient population.

Carbodicarbene-Stibenium Ion-Mediated Functionalization of C(sp3)-H and C(sp)-H Bonds.

Main-group element-mediated C-H activation remains experimentally challenging, and the development of clear concepts and design principles have been limited by the increased reactivity of relevant complexes, especially for the heavier elements. Herein, we report that the stibenium ion [(pyCDC)Sb][NTf2]3 (1) (pyCDC = bis-pyridyl carbodicarbene; NTf2 = bis(trifluoromethanesulfonyl)imide) reacts with acetonitrile in the presence of the base 2,6-di-tert--butylpyridine to enable C(sp3)-H bond breaking to generate the stiba-methylene nitrile complex [(pyCDC)Sb(CH2CN)][NTf2]2 (2). Kinetic analyses were performed to elucidate the rate dependence for all the substrates involved in the reaction. Computational studies suggest that C-H activation proceeds via a mechanism in which acetonitrile first coordinates to the Sb center through the nitrogen atom in a κ1 fashion, thereby weakening the C-H bond which can then be deprotonated by base in solution. Further, we show that 1 reacts with terminal alkynes in the presence of 2,6-di-tert--butylpyridine to enable C(sp)-H bond breaking to form stiba-alkynyl adducts of the type [(pyCDC)Sb(CCR)][NTf2]2 (3a-f). Compound 1 shows excellent specificity for the activation of the terminal C(sp)-H bond even across alkynes with diverse functionality. The resulting stiba-methylene nitrile and stiba-alkynyl adducts react with elemental iodine (I2) to produce iodoacetonitrile and iodoalkynes, while regenerating an Sb trication.

Understanding risk factors for endometrial cancer in young women.

BACKGROUND: The American Cancer Society recommends physicians inform average risk women about endometrial cancer (EC) risk on reaching menopause, but new diagnoses are rising fastest in women <50 years. Educating these women about EC risks requires knowledge of risk factors. However, EC in young women is rare and challenging to study in single study populations. METHODS: We included 13,846 incident EC patients (1,639 < 50 years) and 30,569 matched control individuals from the Epidemiology of Endometrial Cancer Consortium. We used generalized linear models to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for 6 risk factors and EC risk. We created a risk score to evaluate the combined associations and population attributable fractions of these factors. RESULTS: In younger and older women, we observed positive associations with BMI and diabetes, and inverse associations with age at menarche, oral contraceptive use, and parity. Current smoking was associated with reduced risk only in women ≥50 years (PHet<0.01). BMI was the strongest risk factor [OR≥35 vs <25 kg/m2=5.57 (95% CI:4.33-7.16) for <50 years; OR≥35 vs <25 kg/m2=4.68 (95% CI : 4.30-5.09) for ≥50 years; PHet=0.14]. Possessing ≥4 risk factors was associated with ∼9-fold increased risk in women <50 years and ∼4-fold increased risk in women ≥50 years (PHet<0.01). Together, 59.1% of ECs in women <50 and 55.6% in women ≥50 were attributable to these factors. CONCLUSIONS: Our data confirm younger and older women share common EC risk factors. Early educational efforts centered on these factors may help mitigate the rising EC burden in young women.

The improbability of detecting trade-offs and some practical solutions.

Trade-offs are a fundamental concept in evolutionary biology because they are thought to explain much of nature's biological diversity, from variation in life-histories to differences in metabolism. Despite the predicted importance of trade-offs, they are notoriously difficult to detect. Here we contribute to the existing rich theoretical literature on trade-offs by examining how the shape of the distribution of resources or metabolites acquired in an allocation pathway influences the strength of trade-offs between traits. We further explore how variation in resource distribution interacts with two aspects of pathway complexity (i.e., the number of branches and hierarchical structure) affects tradeoffs. We simulate variation in the shape of the distribution of a resource by sampling 106 individuals from a beta distribution with varying parameters to alter the resource shape. In a simple "Y-model" allocation of resources to two traits, any variation in a resource leads to slopes less than -1, with left skewed and symmetrical distributions leading to negative relationships between traits, and highly right skewed distributions associated with positive relationships between traits. Adding more branches further weakens negative and positive relationships between traits, and the hierarchical structure of pathways typically weakens relationships between traits, although in some contexts hierarchical complexity can strengthen positive relationships between traits. Our results further illuminate how variation in the acquisition and allocation of resources, and particularly the shape of a resource distribution and how it interacts with pathway complexity, makes its challenging to detect trade-offs. We offer several practical suggestions on how to detect trade-offs given these challenges.

Tracking the surface structure and the influence of cations and anions on the double-layer region of a Au(111) electrode.

We examined the electric double-layer (EDL) of a Au(111) electrode in a dilute perchloric acid solution using a combination of capacitance measurements and in situ scanning tunnelling microscopy under electrochemical conditions (ECSTM). The "camel-shaped" capacitance curve of the EDL is studied with different cations and anions, including their impact on the potential of zero charge (PZC). We show that the ECSTM images of thermally reconstructed and of the potential-induced surface reconstruction of Au(111) in perchloric acid electrolyte resemble previous work in sulphuric acid, displaying a herringbone pattern for a thermally reconstructed surface. Once the reconstruction is lifted, the Au(111) forms islands with an average of 1 atomic step height. When the potential is lowered below that of the PZC, the potential-induced surface reconstruction results in a more disoriented pattern than the thermally reconstructed surface. ECSTM images at different potentials are correlated with the voltammogram to understand the time and potential dependence of the surface. This correlation has led to the development of a potential window technique that can be used to reveal the surface structure of Au(111) based on observing the changes in PZC in the voltammogram. This method provides an indirect approach to understanding the surface structure without always relying on ECSTM. From the voltammogram, we also observed that anions (SO42-, CH3SO3-, ClO4-, F-) interact more strongly with the Au(111) surface than the alkali cations. The cation capacitance peak shape does not depend strongly on the identity of the alkali metal cation (Li+, Na+, K+). However, the anion capacitance peak depends strongly on the anion identity. It suggests that some level of specific adsorption cannot be excluded, even for anions that are traditionally not considered to adsorb specifically (perchlorate, fluoride).

DASH properties: Estimating atomic and molecular properties from a dynamic attention-based substructure hierarchy.

Recently, we presented a method to assign atomic partial charges based on the DASH (dynamic attention-based substructure hierarchy) tree with high efficiency and quantum mechanical (QM)-like accuracy. In addition, the approach can be considered "rule based"-where the rules are derived from the attention values of a graph neural network-and thus, each assignment is fully explainable by visualizing the underlying molecular substructures. In this work, we demonstrate that these hierarchically sorted substructures capture the key features of the local environment of an atom and allow us to predict different atomic properties with high accuracy without building a new DASH tree for each property. The fast prediction of atomic properties in molecules with the DASH tree can, for example, be used as an efficient way to generate feature vectors for machine learning without the need for expensive QM calculations. The final DASH tree with the different atomic properties as well as the complete dataset with wave functions is made freely available.

lwreg: A Lightweight System for Chemical Registration and Data Storage.

Here, we present lwreg, a lightweight, yet flexible chemical registration system supporting the capture of both two-dimensional molecular structures (topologies) and three-dimensional conformers. lwreg is open source, with a simple Python API, and is designed to be easily integrated into computational workflows. In addition to lwreg itself, we also introduce a straightforward schema for storing experimental data and metadata in the registration database. This direct connection between compound structural information and data generated using those structures creates a powerful tool for data analysis and experimental reproducibility. The software is available at and installable directly from https://github.com/rinikerlab/lightweight-registration.

Functional role of metabolic suppression in avian thermoregulation in the heat.

Hypometabolism arising from active metabolic suppression occurs in several contexts among endotherms, particularly during heterothermic states such as torpor. However, observed Q10 ≈ 1 for avian resting metabolic rate within the thermoneutral zone, values far below the Q10 = 2-3 expected on the basis of Arrhenius effects, suggests hypometabolism also plays a role in birds' thermoregulation at environmental temperatures approaching or exceeding normothermic body temperature (Tb). We evaluated the occurrence of hypometabolism during heat exposure among birds by re-analysing literature data to quantify changes in Tb and resting metabolic rate (RMR) near the upper boundary of the thermoneutral zone, at air temperatures (Tair) between the inflection above which Tb increases above normothermic levels (Tb.inf) and the upper critical limit of thermoneutrality (Tuc). Among the ∼55 % of species in which Tuc - Tb.inf > 0, Q10 < 2-3 occurred in nine of 10 orders for which suitable data exist, indicating that hypometabolism during heat exposure is widespread across the avian phylogeny. Values of Q10 < 2-3 were not restricted to small body mass, as previously proposed. Our findings support the idea that metabolic suppression reduces avian metabolic heat production and hence evaporative cooling requirements during heat exposure, with reductions of 20-30 % in RMR in some species. Moreover, these findings add to evidence that hypometabolism is an important component of heat tolerance among endotherms such as birds and tropical arboreal mammals.

Reducing information avoidance: The effectiveness of humour, cute animals and coping messages.

OBJECTIVES: Guided by the hedonic surplus/mood-as-resource hypotheses, we sought to identify message components that prevent health information avoidance by inducing hedonic psychological states. DESIGN: Two experimental studies. METHODS: Participants, age 45-75, recruited from the online survey platform, Prolific (Study 1 N = 288, Study 2 N = 505), completed a survey of their colorectal cancer (CRC) information avoidance tendency and demographics. They were reinvited to participate in a study where they were randomized to view one of four types of images: humorous comics, cute animals, coping messages or streetscapes images (control condition). To assess CRC information avoidance behaviour after viewing the stimuli, participants choose whether to be directed to a website to complete a CRC risk calculator (Study 1), or whether to view a CRC information video or a video about foot care (Study 2). Using logistic regression, we regressed each outcome variable on interactions between self-reported CRC information avoidance tendency and experimental condition. We then used the PROCESS macro to test if mood mediated these interaction effects. RESULTS: In Study 1, to the degree participants reported CRC information avoidance tendency, viewing humorous comics compared to control images increased their odds of choosing to view the risk calculator (OR = 5.26, p = .02). The same was true in Study 2 for choosing to watch the video about CRC vs. foot care (OR = 2.42, p = .04). Effects were not mediated through mood and there were no effects for the cute animals or coping messages. CONCLUSIONS: Using humour at the outset of a health message may increase reach to people who otherwise avoid CRC or other health messaging.

Elevated tumor necrosis factor alpha and vascular endothelial growth factor in intermediate age-related macular degeneration and geographic atrophy.

Introduction: Tumor necrosis factor alpha (TNF-α) is an inflammatory cytokine implicated in pathological changes to the retinal pigment epithelium that are similar to changes in geographic atrophy (GA), an advanced form of age related macular degeneration (AMD). TNF-α also modulates expression of other cytokines including vascular endothelial growth factor (VEGF), leading to choroidal atrophy in models of AMD. The purpose of this study was to investigate systemic TNF-α and VEGF in patients with GA and intermediate AMD (iAMD) compared to controls without AMD. Methods: We examined plasma levels of TNF-α and VEGF in patients with GA, iAMD, and controls without AMD from the University of Colorado AMD registry (2014 to 2021). Cases and controls were characterized by multimodal imaging. TNF-α and VEGF were measured via multiplex immunoassay and data were analyzed using a non-parametric rank based linear regression model fit to plasma biomarkers. Results: There were 97 GA, 199 iAMD patients and 139 controls. TNF-α was significantly increased in GA (Median:9.9pg/ml, IQR:7.3-11.8) compared to iAMD (Median:7.4, IQR:5.3-9.1) and in both GA and iAMD compared to controls (Median:6.4, IQR:5.3-7.8), p<0.01 for all comparisons. VEGF was significantly increased in iAMD (Median:8.9, IQR:4.8-14.3) compared to controls (Median:7.7, IQR:4.6-11.1), p<0.01. There was a significant positive correlation between TNF-α and VEGF in GA (0.46, p<0.01), and iAMD (0.20, p=0.01) with no significant interaction between TNF-α and VEGF in any group. Discussion: These findings suggest TNF-α and VEGF may contribute to systemic inflammatory processes associated with iAMD and GA. TNF-α and VEGF may function as systemic biomarkers for disease development.

Hexa-Fe(III) Carboxylate Complexes Facilitate Aerobic Hydrocarbon Oxidative Functionalization: Rh Catalyzed Oxidative Coupling of Benzene and Ethylene to Form Styrene.

Fe(II) carboxylates react with dioxygen and carboxylic acid to form Fe6(µ-OH)2(µ3-O)2(µ-X)12(HX)2 (X = acetate or pivalate), which is an active oxidant for Rh-catalyzed arene alkenylation. Heating (150-200 °C) the catalyst precursor [(η2-C2H4)2Rh(µ-OAc)]2 with ethylene, benzene, Fe(II) carboxylate, and dioxygen yields styrene >30-fold faster than the reaction with dioxygen in the absence of the Fe(II) carboxylate additive. It is also demonstrated that Fe6(µ-OH)2(µ3-O)2(µ-X)12(HX)2 is an active oxidant under anaerobic conditions, and the reduced material can be reoxidized to Fe6(µ-OH)2(µ3-O)2(µ-X)12(HX)2 by dioxygen. At optimized conditions, a turnover frequency of ∼0.2 s-1 is achieved. Unlike analogous reactions with Cu(II) carboxylate oxidants, which undergo stoichiometric Cu(II)-mediated production of phenyl esters (e.g., phenyl acetate) as side products at temperatures ≥150 °C, no phenyl ester side product is observed when Fe carboxylate additives are used. Kinetic isotope effect experiments using C6H6 and C6D6 give k H/k D = 3.5(3), while the use of protio or monodeutero pivalic acid reveals a small KIE with k H/k D = 1.19(2). First-order dependencies on Fe(II) carboxylate and dioxygen concentration are observed in addition to complicated kinetic dependencies on the concentration of carboxylic acid and ethylene, both of which inhibit the reaction rate at a high concentration. Mechanistic studies are consistent with irreversible benzene C-H activation, ethylene insertion into the formed Rh-Ph bond, ß-hydride elimination, and reaction of Rh-H with Fe6(µ-OH)2(µ3-O)2(µ-X)12(HX)2 to regenerate a Rh-carboxylate complex.

Luminescence Thermometry Probes Local Heat Effects at the Platinum Electrode Surface during Alkaline Water Electrolysis.

Accurate determination of the temperature dynamics at the electrode surface is crucial for advancing electrocatalysis, particularly in the development of stable materials that aid energy conversion and storage technologies. Here, lanthanide-based in situ luminescence thermometry was used to probe local heat effects at the platinum electrode surface during alkaline water electrolysis. It is demonstrated that the oxygen evolution reaction (OER) induces a more significant temperature increase compared to the hydrogen evolution reaction (HER) under the same electrochemical conditions. This difference is attributed to variations in overpotential heating and local effects on Joule heating. Furthermore, local heat effects are not observed at increased electrolyte concentrations during the HER, whereas substantial temperature variations (up to 2 K) are detected for the OER at higher electrolyte concentrations. Our observations highlight the potential of in situ luminescence thermometry to measure interfacial temperature effects during electrocatalytic reactions.

Pre-diagnosis tea and coffee consumption and survival after a diagnosis of ovarian cancer: results from the Ovarian Cancer Association Consortium.

BACKGROUND: Tea and coffee are the most frequently consumed beverages in the world. Green tea in particular contains compounds with potential anti-cancer effects, but its association with survival after ovarian cancer is uncertain. METHODS: We investigated the associations between tea and coffee consumption before diagnosis and survival using data from 10 studies in the Ovarian Cancer Association Consortium. Data on tea (green, black, herbal), coffee and caffeine intake were available for up to 5724 women. We used Cox proportional hazards regression to estimate adjusted hazard ratios (aHR) and 95% confidence intervals (CI). RESULTS: Compared with women who did not drink any green tea, consumption of one or more cups/day was associated with better overall survival (aHR = 0.84, 95% CI 0.71-1.00, p-trend = 0.04). A similar association was seen for ovarian cancer-specific survival in five studies with this information (aHR = 0.81, 0.66-0.99, p-trend = 0.045). There was no consistent variation between subgroups defined by clinical or lifestyle characteristics and adjustment for other aspects of lifestyle did not appreciably alter the estimates. We found no evidence of an association between coffee, black or herbal tea, or caffeine intake and survival. CONCLUSION: The observed association with green tea consumption before diagnosis raises the possibility that consumption after diagnosis might improve patient outcomes.

Effects of lead on avian thermoregulation in the heat: An experimental test with pied crows (Corvus albus).

Many of the negative physiological effects of lead involve the hypothalamus, but the possibility that thermoregulation is affected has received little attention. We tested the hypothesis that lead exposure reduces avian thermoregulatory performance under hot conditions in pied crows (Corvus albus) experimentally exposed to lead in their diet. Crows in our high lead treatment (blood [Pb] = 87.3 ± 44.7 µg dL-1) showed significantly higher air temperature (Tair) inflections for evaporative water loss (EWL) and resting metabolic rate (RMR) compared to control (6.4 ± 1.8 µg dL-1) or intermediate (53.9 ± 23.7 µg dL-1) lead groups, which did not differ. EWL, RMR and body temperature (Tb) all increased more rapidly at Tair > Tb in the high lead treatment. In contrast, neither maximum Tair tolerated by the crows nor maximum Tb varied with treatment. Our data reveal that water and energy balance during hot weather is affected by lead exposure.

Effect of a Physisorbed Tetrabutylammonium Cation Film on Alkaline Hydrogen Evolution Reaction on Pt Single-Crystal Electrodes.

The addition of tetrabutylammonium (TBA+) to alkaline electrolytes enhances the hydrogen evolution reaction (HER) activity on Pt single-crystal electrodes. The concentration of TBA+ significantly influences the HER on Pt(111). Concentrations of ≤1 mM yield no significant effect on HER currents or the coverage of adsorbed hydrogen (H*) but exhibit an interaction with the OHads on the surface. Conversely, concentrations of >1 mM result in an apparent site-blocking effect for underpotential-deposited H* caused by the physisorption of the organic cation, which counterintuitively leads to an increase in the HER activity. The physisorption of TBA+ is linked to its accumulation in the diffuse layer, as it can be reversibly removed by the addition of nonadsorbing cations such as sodium. Following the previous literature on the TBA+ interaction with electrode surfaces, we ascribe this effect to the formation of a two-dimensional TBA+ film in the double layer. On stepped Pt single-crystal surfaces, TBA+ enhances HER activity at all concentrations, primarily at step sites. Our findings not only highlight the complexities of TBA+ accumulation on Pt electrodes but also offer important molecular-level insights for optimizing the HER by organic film formation on various atomic-level electrode structures.

Where do ICU trainees really look? An eye-tracking analysis of gaze patterns during central venous catheter insertion.

BACKGROUND: There is limited knowledge about gaze patterns of intensive care unit (ICU) trainee doctors during the insertion of a central venous catheter (CVC). The primary objective of this study was to examine visual patterns exhibited by ICU trainee doctors during CVC insertion. Additionally, the study investigated whether differences in gaze patterns could be identified between more and less experienced trainee doctors. METHODS: In a real-life, prospective observational study conducted at the interdisciplinary ICU at the University Hospital Zurich, Switzerland, ICU trainee doctors underwent eye-tracking during CVC insertion in a real ICU patient. Using mixed-effects model analyses, the primary outcomes were dwell time, first fixation duration, revisits, fixation count, and average fixation time on different areas of interest (AOI). Secondary outcomes were above eye-tracking outcome measures stratified according to experience level of participants. RESULTS: Eighteen participants were included, of whom 10 were inexperienced and eight more experienced. Dwell time was highest for CVC preparation table (p = 0.02), jugular vein on ultrasound image (p < 0.001) and cervical puncture location (p < 0.001). Concerning experience, dwell time and revisits on jugular vein on ultrasound image (p = 0.02 and p = 0.04, respectively) and cervical puncture location (p = 0.004 and p = 0.01, respectively) were decreased in more experienced ICU trainees. CONCLUSIONS: Various AOIs have distinct significance for ICU trainee doctors during CVC insertion. Experienced participants exhibited different gaze behavior, requiring less attention for preparation and handling tasks, emphasizing the importance of hand-eye coordination.

Unmasking a Silent Threat: Office-Based Diagnosis of an Ascending Aortic Dissection With Transthoracic Echocardiography.

Type A aortic dissection (TAAD) is a potentially life-threatening diagnosis that can present with elusive symptomatology. A high degree of clinical suspicion is necessary for prompt diagnosis and management. We describe a case of a transthoracic echo (TTE) in a non-suspicious clinic patient diagnosed with TAAD. A 66-year-old Caucasian male presented for a routine clinic visit with one episode of acute severe chest pain. An echocardiogram was ordered for further workup of hypertension and chest discomfort. The echocardiogram demonstrated an ejection fraction of 60% without significant valvular abnormalities. There was suspicion of aortic pathology, which required multiple attending to review the images. The final interpretation was TAAD with a thrombus present in the false lumen. The patient then presented to the Emergency Department. A computed tomographic angiography was performed, which subsequently confirmed the TAAD. The patient was admitted to the cardiovascular ICU and ultimately underwent a successful repair of the dissection. The patient had an unremarkable post-operative course and was ultimately discharged home. Our case demonstrated a diagnosis of TAAD by office-based TTE as the original imaging modality. While this was unconventional, a TAAD should remain on the differential diagnosis when being ordered for the patient's with uncontrolled hypertension with chest pain as a presenting symptom.