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The Cu-catalyzed azide–alkyne cycloaddition (CuAAC) reaction is used as a ligation tool throughout chemical and biological sciences. Despite the pervasiveness of CuAAC, there is a need to develop more efficient methods to form 1,4-triazole ligated products with low loadings of Cu. In this paper, we disclose a mechanistic model for the ynamine-azide (3 + 2) cycloadditions catalyzed by copper(II) acetate. Using multinuclear nuclear magnetic resonance spectroscopy, electron paramagnetic resonance spectroscopy, and high-performance liquid chromatography analyses, a dual catalytic cycle is identified. First, the formation of a diyne species via Glaser–Hay coupling of a terminal ynamine forms a Cu(I) species competent to catalyze an ynamine-azide (3 + 2) cycloaddition. Second, the benzimidazole unit of the ynamine structure has multiple roles: assisting C–H activation, Cu coordination, and the formation of a postreaction resting state Cu complex after completion of the (3 + 2) cycloaddition. Finally, reactivation of the Cu resting state complex is shown by the addition of isotopically labeled ynamine and azide substrates to form a labeled 1,4-triazole product. This work provides a mechanistic basis for the use of mixed valency binuclear catalytic Cu species in conjunction with Cu-coordinating alkynes to afford superior reactivity in CuAAC reactions. Additionally, these data show how the CuAAC reaction kinetics can be modulated by changes to the alkyne substrate, which then has a predictable effect on the reaction mechanism.

Spearfishing is a common activity used to harvest coastal marine species worldwide and can be a significant contributor to landings of ecologically and economically relevant species. As such, it is important to monitor spearfishing catch and effort. Spearfishing is commonly practiced throughout the Caribbean, yet characteristics of this gear's fishery remain understudied in the region. Thus, the objectives of this study were to provide a description of the Puerto Rico spearfishing fishery utilizing a long‐term MRIP APAIS data set, examine the data set quality of this survey, and provide suggestions to improve MRIP implementation in the U.S. Caribbean. We described the Puerto Rico recreational spearfishing fishery using a multidecadal (2000–2015) Marine Recreational Information Program (MRIP) Access Point Angler Intercept Survey conducted along the coast of Puerto Rico and surrounding territories. Data issues were identified in the survey results, including possible errors in measurement and identification; therefore, we limited analyses to species composition, enumeration, and mean catch rates. There were 89 species identified, with snappers (family Lutjanidae) being the most encountered family. Other economically relevant finfish frequently reported were Hogfish Lachnolaimus maximus(n= 121), Queen Triggerfish Balistes vetula(n= 115), and Red Hind Epinephelus guttatus(n= 90). Multiple reef fishes were landed during their spawning season, while prohibited by seasonal closures. Further, spearfishing accounted for 25.8% of the total harvest throughout the study period. Our results suggest that spearfishing could be a considerable contributor to finfish landings in Puerto Rico, warranting its continued and improved monitoring in the region. Further, modifications in the design of fisheries surveys are warranted. We suggest increasing the allocation of resources, training, data quality assurance and quality control, and funding for the MRIP to maximize the accuracy of data obtained and meet MRIP U.S. Caribbean priorities. Implementation of a recreational fishing license would assist by creating a registry to monitor total recreational fishing effort and by generating funds to supplement the MRIP. The use of electronic reporting can help mitigate discrepancies with species identification and size measurements and enhance overall recreational fisheries data collection. Impact statementSpearfishing, a commonly practiced yet poorly understood activity in the Caribbean, was described in Puerto Rico using a long‐term recreational fishing survey. Eighty‐nine species were harvested by spear fishers, including deepwater fishes, suggesting that multiple gears are used on fishing trips. Spearfishing accounted for a considerable amount of recreational landings throughout the study period. Further, several economically relevant finfishes were harvested during their spawning season closures. We conclude that spearfishing could be a considerable contributor to finfish landings in Puerto Rico, warranting its continued and improved monitoring in the region. Various issues were identified in the survey design, and we provide recommendations to improve recreational fisheries data collection in the Caribbean. Spearfishing, a commonly practiced yet poorly understood activity in the Caribbean, was described in Puerto Rico using a long‐term recreational fishing survey. Eighty‐nine species were harvested by spear fishers, including deepwater fishes, suggesting that multiple gears are used on fishing trips. Spearfishing accounted for a considerable amount of recreational landings throughout the study period. Further, several economically relevant finfishes were harvested during their spawning season closures. We conclude that spearfishing could be a considerable contributor to finfish landings in Puerto Rico, warranting its continued and improved monitoring in the region. Various issues were identified in the survey design, and we provide recommendations to improve recreational fisheries data collection in the Caribbean.

Native chemical ligation (NCL) at proline has been limited by cost and synthetic access. In addition, prior examples of NCL using mercaptoproline have exhibited stalling of the reaction after thioester exchange, due to inefficient S→ Nacyl transfer. Herein, we develop methods, using inexpensive Boc-4R-hydroxyproline, for the solid-phase synthesis of peptides containing N-terminal 4R-mercaptoproline and 4R-selenoproline. The synthesis proceeds via proline editing on the N-terminus of fully synthesized peptides on the solid phase, converting an N-terminal Boc-4R-hydroxyproline to the 4S-bromoproline, followed by an SN2 reaction with potassium thioacetate or selenobenzoic acid. After cleavage from the resin and deprotection, peptides with functionalized N-terminal proline amino acids were obtained. NCL reactions with mercaptoproline proceeded slowly under standard NCL conditions, with the S-acyl transthioesterification intermediate observed as a major species. Computational investigations indicated that the bicyclic intermediates and transition states for S→ Nacyl transfer are sufficiently low in energy (10–15 kcal mol–1above starting material) that ring strain cannot explain the slow S→ Nacyl transfer. Instead, the bicyclic zwitterionic tetrahedral intermediate has a low barrier for reversion to the S-acyl intermediate, causing reversion to the thioester (reverse reaction) to occur preferentially over elimination to generate the amide (forward reaction). We hypothesized that a buffer capable of general acid and/or general base catalysis could promote S→ Nacyl transfer and thus achieve greater efficiency in proline NCL. In the presence of 2 M imidazole at pH 6.8, NCL with mercaptoproline proceeded efficiently to generate the peptide with a native amide bond. NCL with selenoproline also proceeded efficiently to generate the desired products when a thiophenol thioester was employed as a ligation partner. After desulfurization or deselenization, the products obtained were identical to those synthesized directly, confirming that the solid-phase proline editing reactions proceeded stereospecifically and without epimerization.

Carotenoids are plant pigments with light filtering and antioxidant properties that deposit in human tissues, including retina and skin. Descriptive characteristics and covariates of carotenoid status in macula and skin have been examined in adults; however, similar studies in children are limited. Thus, this study aimed to delineate how factors of age, sex, race, weight status, and dietary carotenoid intake relate to macular and skin carotenoids in children.

Phosphorylation and dephosphorylation of proteins by kinases and phosphatases are central to cellular responses and function. The structural effects of serine and threonine phosphorylation were examined in peptides and in proteins, by circular dichroism, NMR spectroscopy, bioinformatics analysis of the PDB, small-molecule X-ray crystallography, and computational investigations. Phosphorylation of both serine and threonine residues induces substantial conformational restriction in their physiologically more important dianionic forms. Threonine exhibits a particularly strong disorder-to-order transition upon phosphorylation, with dianionic phosphothreonine preferentially adopting a cyclic conformation with restricted ϕ (ϕ ∼ −60°) stabilized by three noncovalent interactions: a strong intraresidue phosphate-amide hydrogen bond, an n → π* interaction between consecutive carbonyls, and an n → σ* interaction between the phosphate Oγ lone pair and the antibonding orbital of C–Hβ that restricts the χ2side-chain conformation. Proline is unique among the canonical amino acids for its covalent cyclization on the backbone. Phosphothreonine can mimic proline’s backbone cyclization via noncovalent interactions. The preferred torsions of dianionic phosphothreonine are ϕ,ψ = polyproline II helix > α-helix (ϕ ∼ −60°); χ1= g–; χ2∼ +115° (eclipsed C–H/O–P bonds). This structural signature is observed in diverse proteins, including in the activation loops of protein kinases and in protein–protein interactions. In total, these results suggest a structural basis for the differential use and evolution of threonine versus serine phosphorylation sites in proteins, with serine phosphorylation typically inducing smaller, rheostat-like changes, versus threonine phosphorylation promoting larger, step function-like switches, in proteins.

ABSTRACT:Background:Mortality remains a substantial problem after acute ischemic stroke, despite advances in acute stroke treatment over the past three decades. Mortality is particularly high among patients with Total Anterior Circulation Stroke (TACS), generally representing patients with middle cerebral artery occlusions. Notably however, these patients also stand to benefit most from new therapies including endovascular thrombectomy (EVT). In this study, we aimed to examine temporal trends in, and factors associated with, 30-day in-hospital mortality after TACS.Methods:Information on all patients with community-onset TACS from 1994 through 2019 was extracted from a prospective acute stroke registry. Multivariate analysis was performed on the primary outcome of 30-day in-hospital mortality, as well as secondary functional outcomes.Results:We studied 1106 patients hospitalized for community-onset TACS, 456 (41%) of whom experienced 30-day in-hospital mortality. Over the 25 years of observation, 30-day in-hospital mortality rose and then fell. Increased odds of mortality was associated with age and stroke severity. Decreased odds of mortality was associated with alteplase therapy and EVT, as well as presentation to hospital more than 12 hours after stroke onset. Treatment with alteplase, EVT, or both was associated with higher odds of functional independence and discharge home, and shorter lengths of stay in acute care.Conclusions:Patients receiving alteplase, EVT, or both had lower 30-day in-hospital mortality and better functional outcomes than those who were untreated. These observational data demonstrate the benefits of recanalization therapy in routine clinical practice.

Intracardiac catheter ablation for atrial fibrillation with pulmonary vein isolation may result in Takotsubo syndrome (TS), but the frequency, predisposing factors (age, sex, mental health disorders), and outcomes are currently unknown. This study sought to assess the frequency, predisposing factors, and outcomes of subjects who underwent intracardiac catheter ablation for atrial fibrillation with pulmonary vein isolation and were diagnosed with TS. This was a retrospective observational cohort study utilizing TriNetX® electronic health record (EHR) data. We included subjects aged older than 18 years who underwent intracardiac catheter ablation for atrial fibrillation with pulmonary vein isolation. The study population was divided into two groups (no TS diagnostic code presence and TS diagnostic code presence). We analyzed the distributions of age, sex, race, diagnostic codes, common terminology procedures (CPT), and vasoactive medication codes and examined mortality rate within 30 days. We included 69,116 subjects. Of these, 27 (0.04%) had a TS diagnostic code, the cohort was comprised mostly of females [17 (63.0%)], and 1 (3.7%) death within 30 days was reported. There were no significant differences in age and frequency of mental health disorders between those patients in TS and non‐TS cohorts. Adjusting for age, sex, race, ethnicity, patient regionality, and mental health disorder diagnostic code, those patients who developed TS had a significantly higher odds of dying in 30 days after catheter ablation compared to those without TS (OR = 15.97, 95% CI: 2.10–121.55, p= .007). Approximately 0.04% of subjects who underwent intracardiac catheter ablation of atrial fibrillation by pulmonary vein isolation had a subsequent diagnostic code of TS. Further study is needed to determine whether there are predisposing factors associated with the development of TS in subjects who undergo catheter ablation of atrial fibrillation by pulmonary vein isolation. Intracardiac catheter ablation for atrial fibrillation with pulmonary vein isolation may result in Takotsubo syndrome (TS), but the frequency, predisposing factors, and outcomes are currently unknown in this clinical context. Utilizing an electronic health record (EHR) database predominantly in the United States, we found that approximately 0.04% of subjects who underwent intracardiac catheter ablation of atrial fibrillation by pulmonary vein isolation had a subsequent diagnostic code of TS, were comprised primarily of females, but were not of older age or with an increased mental health disorder history.

Background: Damage biomarkers are helpful in early identification of patients who are at risk of developing acute kidney injury (AKI). Investigations are ongoing to identify the optimal role of stress/damage biomarkers in clinical practice regarding AKI risk prediction, surveillance, diagnosis, and prognosis.Objective: To determine the impact of utilizing a clinical decision support system (CDSS) to guide stress biomarker testing in intensive care unit (ICU) patients at risk for drug-induced acute kidney injury (D-AKI).Methods: A protocol was designed utilizing a clinical decision support system (CDSS) alert to identify patients that were ordered 3 or more potentially nephrotoxic medications, suggesting risk for progressing to AKI from nephrotoxic burden. Once alerted to these high-risk patients, the pharmacist determined if action was needed by ordering a stress biomarker test, tissue inhibitor of metalloproteinase-2-insulin-like growth factor-binding protein 7 (TIMP-2•IGFBP7). If the biomarker test result was elevated, the pharmacist provided nephrotoxin stewardship recommendations to the team. Pharmacists recorded the response to the clinical decision support alert, ordering, and interpreting the TIMP-2•IGFBP7, and information regarding clinical interventions. An alert in conjunction with TIMP-2•IGFBP7 as a strategy for AKI risk prediction and stimulant for patient care management was assessed. In addition, barriers and solutions to protocol implementation were evaluated.Results: There were 394 total activities recorded by pharmacists for 345 unique patients. Ninety-three (93/394; 23.6%) actionable alerts resulted in a TIMP-2•IGFBP7 test being ordered. Thirty-one TIMP-2•IGFBP7 results were >0.3 (31/81; 38.3%), suggesting a high-risk of progression to AKI, which prompted 191 pharmacist/team interventions. On average, there were 1.64 interventions per patient in the low-risk patients, 3.43 in high-risk patients, and 3.75 in the highest-risk patients.Conclusion and Relevance: Stress biomarkers can be used in conjunction with CDSS alerts to affect therapeutic decisions in ICU patients at high-risk for D-AKI.

ABSTRACTObjectives:We aimed to determine whether consumption of a fermented dairy beverage containing probiotic microorganisms influences negative mood states, stress, and hippocampal memory performance in healthy adults. Methods:Adults (25-45 yrs, N = 26) free of gastrointestinal and mental illness were enrolled in a single-blind, randomized, controlled, crossover trial. Participants completed testing prior to and after 4-week consumption, with a 2–4 week washout between treatments of: (1) 8 oz of a dairy-based fermented beverage containing 25–30 billion colony forming units of live and active kefir cultures or (2) 8 oz isocaloric, non-fermented, 1% low-fat lactose-free dairy-based control beverage. Hippocampal-dependent relational memory was assessed using a spatial reconstruction task. Negative mood states of depression and anxiety were assessed using the Depression Anxiety Stress Scales-42 (DASS-42). Pooled 24-hour urine samples were analyzed using an enzyme-linked immunosorbent assay to determine urinary free-cortisol (UFC) concentrations. Fecal microbiota composition was assessed using 16S rRNA gene sequencing. Results:Lactobacilluswas increased by 235% following fermented dairy consumption compared to the control (p < .01). Furthermore, the fermented dairy beverage improved performance on two metrics of relational memory, misplacement (p = .04) and object-location binding (p = .03). UFC and DASS-42 scores (all p’s > .08) were not significantly changed by either arm of the intervention. No correlations were observed between the change in Lactobacillusand memory performance. Conclusions:Fermented dairy consumption increased the presence of certain microorganisms in the gut and improved relational memory in healthy adults. However, the benefits observed for relational memory were not related to changes in Lactobacillus.Trial registration:ClinicalTrials.gov identifier: NCT02849275.

Mitochondrial dysfunction and oxidative damage have long been suggested as critically important mechanisms underlying the ageing process in animals. However, conflicting data exist on whether this involves increased production of mitochondrial reactive oxygen species (ROS) during ageing. We employed high‐resolution respirometry and fluorometry on flight muscle (pectoralis major) and liver mitochondria to simultaneously examine mitochondrial function and ROS (H2O2) release rates in young (3 months) and old (4 years) zebra finches (Taeniopygia guttata). Respiratory capacities for oxidative phosphorylation did not differ between the two age groups in either tissue. Respiratory control ratios (RCR) of liver mitochondria also did not differ between the age classes. However, RCR in muscle mitochondria was 55% lower in old relative to young birds, suggesting that muscle mitochondria in older individuals are less efficient. Interestingly, this observed reduction in muscle RCR was driven almost entirely by higher mitochondrial LEAK-state respiration. Maximum mitochondrial ROS release rates were found to be greater in both flight muscle (1.3-fold) and the liver (1.9-fold) of old birds. However, while maximum ROS (H2O2) release rates from mitochondria increased with age across both liver and muscle tissues, the liver demonstrated a proportionally greater age-related increase in ROS release than muscle. This difference in age-related increases in ROS release rates between muscle and liver tissues may be due to increased mitochondrial leakiness in the muscle, but not the liver, of older birds. This suggests that age-related changes in cellular function seem to occur in a tissue-specific manner in zebra finches, with flight muscle exhibiting signs of minimising age-related increase in ROS release, potentially to reduce damage to this crucial tissue in older individuals.

Invasive annual grasses now dominate millions of hectares of rangeland in the Intermountain Western United States. Local annual grass distribution, however, has been shown to follow landscape patterns of slope, aspect, and elevation that are correlated with ecological resilience to stress and disturbance and resistance to annual grass invasion. Although these patterns have previously been linked to soil-climate classes, several mechanistic factors in native-plant seedling establishment are also associated with both topography and seasonal weather patterns in the year following planting. In this study we used the Simultaneous Heat and Water (SHAW) model to estimate long-term weather effects on soil microclimate and hydrothermal-germination models to predict germination response of one fast- and one slow-germinating native grass as a function of planting date, slope, aspect, and elevation in the Boise Foothills in southwestern Idaho. Higher elevation and northerly aspect sites are more likely to defer germination of seeded species until late enough in the fall that they avoid postgermination/preemergence freezing mortality. These sites are also more favorable for survival of emerged seedlings through mid to late summer. Slope, aspect, and elevation effects on modeled restoration outcomes are consistent with previously modeled general patterns of ecological resilience and resistance as a function of soil hydrothermal class, but inclusion of slope and aspect effects may produce finer-scale metrics for mapping these patterns over space. The probabilistic nature of microclimatic variability as a function of elevation may yield useful insights into successful restoration approaches for reestablishment of native plant communities in lower-elevation ecosystems with inherently lower ecological resilience and resistance. The generally arid climate in this region, however, may limit successful restoration outcomes at lower elevation in most years even under conditions of long-term annual grass control.

Understanding the thermal structure of protoplanetary disks is crucial for modeling planet formation and interpreting disk observations. We present a new two-layer radiative transfer model for computing the thermal structure of axisymmetric irradiated disks. Unlike the standard two-layer model, our model accounts for the radial as well as vertical transfer of the starlight reprocessed at the disk surface. The model thus allows us to compute the temperature below “shadowed” surfaces receiving no direct starlight. Thanks to the assumed axisymmetry, the reprocessed starlight flux is given in a one-dimensional integral form that can be computed at a low cost. Furthermore, our model evolves the midplane temperature using a time-dependent energy equation and can therefore treat thermal instabilities. We apply our global two-layer model to disks with a planetary induced gap and confirm that the model reproduces the disks’ temperature profiles obtained from more computationally expensive Monte Carlo radiative transfer calculations to an accuracy of less than 20%. We also apply the model to study the long-term behavior of the thermal wave instability in irradiated disks. Being simple and computationally efficient, the global two-layer model will be suitable for studying the interplay between disks’ thermal evolution and dust evolution.

Diving animals must sustain high muscle activity with finite oxygen (O2) to forage underwater. Studies have shown that some diving mammals exhibit changes in the metabolic phenotype of locomotory muscles compared with non-divers, but the pervasiveness of such changes across diving animals is unclear, particularly among diving birds. Here, we examined whether changes in muscle phenotype and mitochondrial abundance are associated with dive capacity across 17 species of ducks from three distinct evolutionary clades (tribes) in the subfamily Anatinae: the longest diving sea ducks, the mid-tier diving pochards and the non-diving dabblers. In the gastrocnemius (the primary swimming and diving muscle), mitochondrial volume density in both oxidative and glycolytic fiber types was 70% and 30% higher in sea ducks compared with dabblers, respectively. These differences were associated with preferential proliferation of the subsarcolemmal subfraction, the mitochondria adjacent to the cell membrane and nearest to capillaries, relative to the intermyofibrillar subfraction. Capillary density and capillary-to-fiber ratio were positively correlated with mitochondrial volume density, with no variation in the density of oxidative fiber types across tribes. In the pectoralis, sea ducks had greater abundance of oxidative fiber types than dabblers, whereas pochards were intermediate between the two. These data suggest that skeletal muscles of sea ducks have a heightened capacity for aerobic metabolism and an enhanced ability to utilize O2 stores in the blood and muscle while diving.

No therapies for acute coronavirus disease 2019 (COVID-19) have been tested in children to establish effectiveness. Despite this, across 48 hospitals, 235/424 children (55%) admitted to the intensive care or step-down unit with COVID-19 received directed therapies. Systemic steroids and remdesivir were most commonly administered, with use rising from March 2020 to December 2020.

Burns are routinely assessed at the scene of the incident by prehospital or emergency medical services providers. The initial management of burns is based on the calculation of the extent of the injury, reported as percent total body surface area (TBSA). This study evaluates discrepancies in the estimation of TBSA between prehospital providers and burn team physicians over a 3-year period at an academic, university medical center serving as the regional burn center. A total of 120 adult and 27 pediatric patients (younger than age 16 years) were included in this study; 95 (65%) patients were male, 67 (46%) patients were Caucasian, 62 (42%) patients had no healthcare insurance, and the median age was 35 years (interquartile range [IQR] 27). The most common etiology of burns was hot liquid, 39 (26.5%). Median [IQR] and mean (SD) estimated TBSA (%) were 4 [1–10] and 8.6 (12.8) for prehospital providers and 2 [1–6] and 5.9 (9.9) for burn team physicians. Bland–Altman plots evaluating second- and third-degree burns separately and combined demonstrated that, as burns involved more surface area, agreement decreased between emergency medical service providers and burn physicians. Agreement between prehospital providers and burn physicians decreased as TBSA of burns increased. This finding reaffirms the need for more standardized education and training for all medical personnel.

Aim:Generating direct comparative evidence in prospective randomized trials is difficult for rare diseases. Real-world cohorts may supplement control populations. Methods:Entrectinib-treated adults with advanced ROS1fusion-positive NSCLC (n = 94) from Phase I/II trials (ALKA-372-001 [EudraCT2012-00148-88], STARTRK-1 [NCT02097810], and STARTRK-2 [NCT02568267]) were compared with a real-world crizotinib-treated cohort (n = 65). Primary end point, time-to-treatment discontinuation (TTD); secondary end points, PFS and OS. Results:Median (95% CI) weighted TTD: 12.9 (9.9–17.4) months for entrectinib; 8.8 (6.2–9.9) months for crizotinib (weighted hazard ratio: 0.72 [0.51–1.02]). Median OS with entrectinib was not reached, weighted median OS with crizotinib was 18.5 (15.1–19.9) months. Conclusion:Entrectinib administered in clinical trials may be associated with longer TTD than a real-world crizotinib population.

Supplemental stocking of crappie is a primary management strategy in many small southern reservoirs, but survival and contribution to the year‐class in these systems is not known. We assessed the contribution of hatchery fish to the age‐1 year‐class within established crappie populations in four reservoirs ranging 29–74 ha in surface area. Chemically marked White Crappie Pomoxis annularisand magnolia crappie (Black Crappie Pomoxis nigromaculatus× ♀White Crappie) were stocked at 125 fish/ha in 2015 and 2016, respectively. We also stocked a renovated reservoir (40 ha) with White Crappie in 2015 to serve as a reference without intraspecific competition and to provide an estimate of marking efficacy and mark retention. The total length of wild age‐0 fish at the time of stocking averaged 52–60 mm larger than that of their hatchery conspecifics. We only recaptured 11 marked crappie, 10 of which were from the reference reservoir. The recovery of only one hatchery fish from the supplemental stockings yielded a combined stocking contribution of 0.59%, or 0.71% when adjusted for marking efficacy (at least 83%). We concluded that supplemental stocking of crappie in smaller reservoirs is not effective under current the stocking protocols, as contributions <1% cannot justify hatchery and personnel costs. It may be possible to modify the stocking procedures, and potential modifications are discussed.

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