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Background: Periacetabular osteotomy (PAO) is an effective surgical procedure for managing acetabular dysplasia. The purpose of this study was to analyze the biomechanical properties of novel PAO constructs that incorporate orthopaedic trauma techniques. We hypothesize that these fixation methods will create a stiffer construct that tolerates higher loads to failure. Methods: Twenty bio-composite hemi-pelvises underwent PAO with the following fixation configurations: Group A: 4 iliac crest (IC) screws; Group B: 3 IC screws; Group C: 2 IC screws, 1 retrograde anterior column (AC) screw, and 1 lateral compression type-2 (LC2) screw directed from the anterior inferior iliac spine to the posterior inferior iliac spine; Group D: 1 AC screw, 1 LC2 screw, 1 posterior column screw; Group E: 2 LC2 screws, 1 AC screw. Constructs were loaded to failure on a material testing hydraulic press, and ultimate strength, stiffness, and osteotomy displacement were measured. Results: The highest load to failure was seen in group D (2511 N), which was significantly more than groups A (1528 N, P = .0114) and B (1348 N, P < .0001). The stiffest construct was group E (602 N/mm) compared to groups A (315 N/mm, P = .0439) and B (243 N/mm, P = .0008). Failure occurred most often with a fracture in the posterior column. Conclusions: This study supports column fixation methods used in orthopaedic trauma for PAO as biomechanically advantageous to traditional fixation techniques. These constructs may be beneficial to patients with weight-bearing concerns or early rehabilitation needs.

Abstract. Objectives: To compare the stability of screw fixation with that of plate fixation for symphyseal injuries in a vertically unstable pelvic injury (AO/Tile 61-C1) associated with complete disruption of the sacroiliac joint and the pubic symphysis. Methods: Eight fourth-generation composite pelvis models with sacroiliac and pubic symphyseal disruption (Sawbones, Vashon Island, WA) underwent biomechanical testing simulating static single-leg stance. Four were fixed anteriorly with a symphyseal screw, and 4 with a symphyseal plate. All had single transsacral screw fixation posteriorly. Displacement and rotation were monitored at both sacroiliac joint and pubic symphysis. Results: There was no significant difference between the 2 groups for mean maximum force generated. There was no significant difference in net displacement at both sacroiliac joint and pubic symphysis. There was significantly less rotation but more displacement in the screw group in the Z-axis. The screw group showed increased stiffness compared with the plate group. Conclusions: This is the first biomechanical study to compare screw versus plate symphyseal fixation in a Tile C model. Our biomechanical model using anterior and posterior fixation demonstrates that symphyseal screws may be a viable alternative to classically described symphyseal plating.

Background: Wearable devices provide the ability for clinical teams to continuously monitor patients' rehabilitation progress with objective data. Understanding expected recovery patterns following total knee arthroplasty (TKA) enables prompt identification of patients failing to meet these milestones. The aim of this study was to establish normative values for daily functional recovery in the first 6 weeks after TKA using a wearable device., Methods: This prospective study included patients who underwent TKA between 2020 and 2023, treated by 11 surgeons from 8 institutions. Eligible participants were aged 18 or older, had a primary unilateral TKA, and owned a smartphone. Knee range of motion, total daily steps, cadence, and device usage were measured continuously over 6 weeks. Statistical analysis included analysis of variance using post hoc Tukey honest significant difference tests., Results: The cohort of 566 participants had a mean age of 65 and 69 for men and women, respectively (range, 50 to 80). Women comprised 61% (n = 345) of study participants. There were 82% of women and 90% of men who had a body mass index > 30. The average daily wear time of the device was 12 hours (±4) for a total of 45 days (±27). Recovery was nonlinear, with the greatest gains in the first 3 weeks postsurgery for all metrics. Men demonstrated greater total daily step counts and cadence when compared to women. Obese patients demonstrated poorer performance when compared to lower body mass index patients., Conclusions: To our knowledge, this study presents the first normative data for tracking daily functional recovery in TKA patients using wearable sensors. Standardizing the TKA recovery timeline allows surgeons to isolate factors affecting patients' healing processes, accurately counsel them preoperatively, and intervene more promptly postoperatively when rehabilitation is not within standard recovery parameters., (Copyright © 2024 Elsevier Inc. All rights reserved.)

This study developed and validated the Telepsychology Facilitators Scale (TFS), a novel measure that uses the theory of reasoned action and technology acceptance model as frameworks to assess factors that influence psychologists' openness to using telepsychology. At the beginning of the COVID-19 pandemic, an online sample of 2,619 psychologists completed initial items considered for the TFS, along with a measure assessing their actual use of telepsychology. The sample was split in half, with a preliminary exploratory factor analysis ultimately revealing a 13-item general scale with four distinct subscales (Positive Attitudes, Facilitating Infrastructure, Organizational Support, and External Policies). Higher scores on each subscale positively correlated with psychologists' percentage of patient treatment conducted with telepsychology. The exploratory factor analysis subscale structure was subsequently supported via confirmatory factory analyses of a four-factor structure and bifactor structure (tested separately) with the other half of the sample, revealing adequate model fit for both models and similar convergent validity. The TFS may help the field assess the potential barriers and drivers of telepsychology use among psychologists and be used to inform future organizational and policy efforts to increase telepsychology implementation and use across health service settings. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

3-mercaptopropionate (3MPA) dioxygenase (MDO) is a mononuclear nonheme iron enzyme that catalyzes the O 2 -dependent oxidation of thiol-bearing substrates to yield the corresponding sulfinic acid. MDO is a member of the cysteine dioxygenase family of small molecule thiol dioxygenases and thus shares a conserved sequence of active site residues (Serine-155, Histidine-157, and Tyrosine-159), collectively referred to as the SHY-motif. It has been demonstrated that these amino acids directly interact with the mononuclear Fe-site, influencing steady-state catalysis, catalytic efficiency, O 2 -binding, and substrate coordination. However, the underlying mechanism by which this is accomplished is poorly understood. Here, pulsed electron paramagnetic resonance spectroscopy [ 1 H Mims electron nuclear double resonance spectroscopy] is applied to validate density functional theory computational models for the MDO Fe-site simultaneously coordinated by substrate and nitric oxide (NO), (3MPA/NO)-MDO. The enhanced resolution provided by electron nuclear double resonance spectroscopy allows for direct observation of Fe-bound substrate conformations and H-bond donation from Tyr159 to the Fe-bound NO ligand. Further inclusion of SHY-motif residues within the validated model reveals a distinct channel restricting movement of the Fe-bound NO-ligand. It has been argued that the iron-nitrosyl emulates the structure of potential Fe(III)-superoxide intermediates within the MDO catalytic cycle. While the merit of this assumption remains unconfirmed, the model reported here offers a framework to evaluate oxygen binding at the substrate-bound Fe-site and possible reaction mechanisms. It also underscores the significance of hydrogen bonding interactions within the enzymatic active site., Competing Interests: Conflict of interest The authors declare that they have no conflicts of interest with the contents of this article., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

A series of tridentate copper(II) N -heterocyclic carbene (NHC) complexes with imidazole, benzimidazole, and 5,6-dimethylbenzimidazole azole rings were synthesized and comprehensively characterized via X-ray crystallography, ESI-MS, cyclic voltammetry, and UV-Vis and EPR spectroscopic studies. These complexes were then utilized for the optimization of ketone reduction under sustainable conditions using 2-acetylpyridine and phenylsilane. The relationships between product formation, temperature, reaction time, and catalyst loading for the hydrogenation reactions are covered in detail. Reduction of eighteen different aliphatic, cyclic, and aromatic ketones were demonstrated, which were compatible to produce the corresponding products in moderate to good yields. These systems were used to develop related DNA-hybrid catalytic systems, but only supported weak enantioselectivity. Further thermodynamic experiments showed Cu-NHC complexes did not demonstrate specific binding to DNA, which is consistent with their limited selectivity.

A new tridentate Cu 2+ complex based on ( E )-1-(pyridin-2-yl)- N -(quinolin-8-yl)methanimine (PQM) was generated and characterized to support the activation of diazo compounds for the formation of new C-N bonds. This neutral Schiff base ligand was structurally characterized to coordinate with copper(II) in an equatorial fashion, yielding a distorted octahedral complex. Upon characterization, this copper(II) complex was used to catalyze an efficient and cost-effective protocol for C-N bond formation between N -nucleophiles and copper carbene complexes arising from the activation of diazo carbonyl compounds. A substrate scope of approximately 15 different amine-based substrates was screened, yielding 2° or 3° amine products with acceptable to good yields under mild reaction conditions. Reactivity towards phenol and thiophenol were also screened, showing relatively weak C-O or C-S bond formation under optimized conditions.

Reaction of the nitrosylated-iron metallodithiolate ligand, paramagnetic (NO)Fe(N 2 S 2 ), with [M(CH 3 CN) n ][BF 4 ] 2 salts (M = Ni II , Pd II , and Pt II ; n = 4 or 6) affords di-radical tri-metallic complexes in a stairstep type arrangement ([FeMFe] 2+ , M = Ni, Pd, and Pt), with the central group 10 metal held in a MS 4 square plane. These isostructural compounds have nearly identical ν (NO) stretching values, isomer shifts, and electrochemical properties, but vary in their magnetic properties. Despite the intramolecular Fe⋯Fe distances of ca. 6 Å, antiferromagnetic coupling is observed between {Fe(NO)} 7 units as established by magnetic susceptibility, EPR, and DFT studies. The superexchange interaction through the thiolate sulfur and central metal atoms is on the order of Ni II < Pd II ≪ Pt II with exchange coupling constants ( J ) of -3, -23, and -124 cm -1 , consistent with increased covalency of the M-S bonds (3d < 4d < 5d). This trend is reproduced by DFT calculations with molecular orbital analysis providing insight into the origin of the enhancement in the exchange interaction. Specifically, the magnitude of the exchange interaction correlates surprisingly well with the energy difference between the HOMO and HOMO-1 orbitals of the triplet states, which is reflected in the central metal's contribution to these orbitals. These results demonstrate the ability of sulfur-dense metallodithiolate ligands to engender strong magnetic communication by virtue of their enhanced covalency and polarizability., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Mammalian stearoyl-CoA desaturase-1 (SCD1) introduces a double-bond to a saturated long-chain fatty acid in a reaction catalyzed by a diiron center. The diiron center is well-coordinated by conserved histidine residues and is thought to remain with the enzyme. However, we find here that SCD1 progressively loses its activity during catalysis and becomes fully inactive after about nine turnovers. Further studies show that the inactivation of SCD1 is due to the loss of an iron (Fe) ion in the diiron center and that the addition of free ferrous ions (Fe 2+ ) sustains the enzymatic activity. Using SCD1 labeled with Fe isotope, we further show that free Fe 2+ is incorporated into the diiron center only during catalysis. We also discover that the diiron center in SCD1 has prominent electron paramagnetic resonance signals in its diferric state, indicative of distinct coupling between the two ferric ions. These results reveal that the diiron center in SCD1 is structurally dynamic during catalysis and that labile Fe 2+ in cells could regulate SCD1 activity and hence lipid metabolism., Competing Interests: Conflict of interest The authors declare that they have no conflicts of interest with the contents of this article., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

The COVID-19 pandemic transformed the delivery of psychological services as many psychologists adopted telepsychology for the first time or dramatically increased their use of it. The current study examined qualitative and quantitative data provided by 2619 practicing psychologists to identify variables facilitating and impeding the adoption of telepsychology in the U.S. at the beginning of the COVID-19 pandemic. The top five reported barriers were: inadequate access to technology, diminished therapeutic alliance, technological issues, diminished quality of delivered care or effectiveness, and privacy concerns. The top five reported facilitators were: increased safety, better access to patient care, patient demand, efficient use of time, and adequate technology for telepsychology use. Psychologists' demographic and practice characteristics robustly predicted their endorsement of telepsychology barriers and facilitators. These findings provide important context into the implementation of telepsychology at the beginning of the pandemic and may serve future implementation strategies in clinics and healthcare organizations attempting to increase telepsychology utilization.

Thiol dioxygenases are a subset of non-heme mononuclear iron oxygenases that catalyze the O 2 -dependent oxidation of thiol-bearing substrates to yield sulfinic acid products. Cysteine dioxygenase (CDO) and 3-mercaptopropionic acid (3MPA) dioxygenase (MDO) are the most extensively characterized members of this enzyme family. As with many non-heme mononuclear iron oxidase/oxygenases, CDO and MDO exhibit an obligate-ordered addition of organic substrate before dioxygen. As this substrate-gated O 2 -reactivity extends to the oxygen-surrogate, nitric oxide (NO), EPR spectroscopy has long been used to interrogate the [substrate:NO:enzyme] ternary complex. In principle, these studies can be extrapolated to provide information about transient iron-oxo intermediates produced during catalytic turnover with dioxygen. In this work, we demonstrate that cyanide mimics the native thiol-substrate in ordered-addition experiments with MDO cloned from Azotobacter vinelandii (AvMDO). Following treatment of the catalytically active Fe(II)-AvMDO with excess cyanide, addition of NO yields a low-spin (S = 1/2) (CN/NO)-Fe-complex. Continuous wave and pulsed X-band EPR characterization of this complex produced in wild-type and H157N variant AvMDO reveal multiple nuclear hyperfine features diagnostic of interactions within the first- and outer-coordination sphere of the enzymatic Fe-site. Spectroscopically validated computational models indicate simultaneous coordination of two cyanide ligands replaces the bidentate (thiol and carboxylate) coordination of 3MPA allowing for NO-binding at the catalytically relevant O 2 -binding site. This promiscuous substrate-gated reactivity of AvMDO with NO provides an instructive counterpoint to the high substrate-specificity exhibited by mammalian CDO for L-cysteine., (© 2023. The Author(s), under exclusive licence to Society for Biological Inorganic Chemistry (SBIC).)

The synthesis of sulfur-bridged Fe-Ni heterobimetallics was inspired by Nature's strategies to "trick" abundant first row transition metals into enabling 2-electron processes: redox-active ligands (including pendant iron-sulfur clusters) and proximal metals. Our design to have redox-active ligands on each metal, NO on iron and dithiolene on nickel, resulted in the observation of unexpectedly intricate physical properties. The metallodithiolate, (NO)Fe(N 2 S 2 ), reacts with a labile ligand derivative of [Ni II (S 2 C 2 Ph 2 )] 0 , Ni DT , yielding the expected S-bridged neutral adduct, FeNi , containing a doublet {Fe(NO)} 7 . Good reversibility of two redox events of FeNi led to isolation of reduced and oxidized congeners. Characterization by various spectroscopies and single-crystal X-ray diffraction concluded that reduction of the FeNi parent yielded [FeNi] - , a rare example of a high-spin {Fe(NO)} 8 , described as linear Fe II (NO - ). Mössbauer data is diagnostic for the redox change at the {Fe(NO)} 7/8 site. Oxidation of FeNi generated the 2 [FeNi] + ⇌ [Fe 2 Ni 2 ] 2+ equilibrium in solution; crystallization yields only the [Fe 2 Ni 2 ] 2+ dimer, isolated as PF 6 - and BArF - salts. The monomer is a spin-coupled diradical between {Fe(NO)} 7 and Ni DT + , while dimerization couples the two Ni DT + via a Ni 2 S 2 rhomb. Magnetic susceptibility studies on the dimer found a singlet ground state with a thermally accessible triplet excited state responsible for the magnetism at 300 K (χ M T = 0.67 emu·K·mol -1 , µ eff = 2.31 µ B ), and detectable by parallel-mode EPR spectroscopy at 20 to 50 K. A theoretical model built on an H 4 chain explains this unexpected low energy triplet state arising from a combination of anti- and ferromagnetic coupling of a four-radical molecular conglomerate.

The COVID-19 pandemic has altered life globally like no other event in modern history, and psychological service changes to meet the resultant impacts on families have not been assessed in the empirical literature. The purpose of the current study was to examine whether family systems therapists increased their teletherapy use during the pandemic relative to prepandemic usage, and whether projected postpandemic rates would remain at the same level; further, environmental and demographic predictors of these changes were examined. In May 2020, a sample of 626 family systems therapists (58.6% women, 40.6% men; M = 57.4 years old; M years in practice = 25.5) completed a national online study assessing these variables. Results suggested that family systems therapists performed 7.92% of their clinical work using teletherapy before the pandemic and 88.17% during the pandemic. They also projected that they would perform 36.57% of their clinical work using teletherapy after the pandemic. Teletherapy uptake was unrelated to primary practice setting, provider age, gender, race/ethnicity, and practice location (urban/suburban vs. rural) but was higher for family systems therapists who reported increased supportive teletherapy policies and training in their practice setting. Organizational infrastructure and availability of training played an important role in influencing teletherapy uptake during the pandemic. Family systems therapists have a unique opportunity to deploy teletherapy modalities to meet the needs of families during the COVID-19 pandemic, and infrastructure and training to do so may facilitate that work., (© 2021 Family Process Institute. This article is a U.S. Government work and is in the public domain in the USA.)

Telepsychology has the potential to help mental health service providers reach millions of people in rural areas or those limited by other factors. This study examined pre-COVID-19 deterrents reported by psychologists who did not use telepsychology. Participants were 1,400 psychologists with an average of 26.3 ( SD = 11.18) years in practice who were currently practicing within the United States but did not currently use telepsychology. All 50 states were represented as well as Washington, DC. The most commonly reported deterrents, from most to least frequent, were insufficient training, client safety/crisis concerns, privacy, legality, ethics, reimbursement, efficacy, prohibitive organizational policies/culture, and insufficient demand. Logistic regression analyses suggested that psychologists' deterrents varied based in part on demographic and practice characteristics. Psychologists practicing within medical centers or Veterans Affairs facilities were less likely to indicate safety, privacy, legal issues, ethics, and efficacy as a concern. Older psychologists were less deterred by reimbursement issues and more concerned about effectiveness. Those using cognitive-behavioral approaches were less likely to report efficacy and safety concerns. Cisgender men were less likely to be deterred by safety or privacy issues, and White psychologists were less likely to indicate safety as a deterrent. Additional telepsychology training and information for psychologists may increase its use and foster improved mental health care access for populations unable to attend in-person sessions. A more focused approach to training and implementation of telepsychology that considers the needs and concerns of the target psychologist group could benefit organizations promoting its use. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

The human copper-binding protein metallothionein-3 (MT-3) can reduce Cu(II) to Cu(I) and form a polynuclear Cu(I) 4 -Cys 5-6 cluster concomitant with intramolecular disulfide bonds formation, but the cluster is unusually inert toward O 2 and redox-cycling. We utilized a combined array of rapid-mixing spectroscopic techniques to identify and characterize the transient radical intermediates formed in the reaction between Zn 7 MT-3 and Cu(II) to form Cu(I) 4 Zn(II) 4 MT-3. Stopped-flow electronic absorption spectroscopy reveals the rapid formation of transient species with absorption centered at 430-450 nm and consistent with the generation of disulfide radical anions (DRAs) upon reduction of Cu(II) by MT-3 cysteine thiolates. These DRAs are oxygen-stable and unusually long-lived, with lifetimes in the seconds regime. Subsequent DRAs reduction by Cu(II) leads to the formation of a redox-inert Cu(I) 4 -Cys 5 cluster with short Cu-Cu distances (<2.8 Å), as revealed by low-temperature (77 K) luminescence spectroscopy. Rapid freeze-quench Raman and electron paramagnetic resonance (EPR) spectroscopy characterization of the intermediates confirmed the DRA nature of the sulfur-centered radicals and their subsequent oxidation to disulfide bonds upon Cu(II) reduction, generating the final Cu(I) 4 -thiolate cluster. EPR simulation analysis of the radical g - and A -values indicate that the DRAs are directly coupled to Cu(I), potentially explaining the observed DRA stability in the presence of O 2 . We thus provide evidence that the MT-3 Cu(I) 4 -Cys 5 cluster assembly process involves the controlled formation of novel long-lived, copper-coupled, and oxygen-stable disulfide radical anion transient intermediates.

3-Mercaptopropionic acid ( 3MPA ) dioxygenase (MDO) is a non-heme Fe(II)/O 2 -dependent oxygenase that catalyzes the oxidation of thiol-substrates to yield the corresponding sulfinic acid. Hydrogen-bonding interactions between the Fe-site and a conserved set of three outer-sphere residues (Ser-His-Tyr) play an important catalytic role in the mechanism of this enzyme. Collectively referred to as the SHY-motif, the functional role of these residues remains poorly understood. Here, catalytically inactive Fe(III)-MDO precomplexed with 3MPA was titrated with cyanide to yield a low-spin ( S = 1/2) ( 3MPA /CN)-bound ternary complex (referred to as 1C ). UV-visible and electron paramagnetic resonance (EPR) spectroscopy were used to monitor the binding of 3MPA and cyanide. Comparisons of results obtained from SHY-motif variants (H157N and Y159F) were performed to investigate specific H-bonding interactions. For the wild-type enzyme, the binding of 3MPA - and cyanide to the enzymatic Fe-site is selective and results in a homogeneous ternary complex. However, this selectivity is lost for the Y159F variant, suggesting that H-bonding interactions contributed from Tyr159 gate ligand coordination at the Fe-site. Significantly, the g -values for the low-spin ferric site are diagnostic of the directionality of Tyr159 H-bond donation. Computational models coupled with CASSCF/NEVPT2-calculated g -values were used to verify that a major shift in the central g -value ( g 2 ) displayed between wild-type and SHY variants could be attributed to the loss of Tyr159 H-bond donation to the Fe-bound cyanide. Applied to native cosubstrate, this H-bond donation provides a means to stabilize Fe-bound dioxygen and potentially explains the attenuated (∼15-fold) rate of catalytic turnover previously reported for MDO SHY-motif variants.

Objective: The aim of this study is to apply the theory of reasoned action (TRA) and technology acceptance model (TAM) to psychologists' telepsychology use during the COVID-19 pandemic., Methods: A sample of 2619 US-licensed psychologists completed a survey assessing telepsychology use and aspects of both models in May 2020., Results: Cross-sectional TRA and TAM path models evidenced excellent fit in explaining psychologists' telepsychology use. The TRA indicated that psychologists' attitudes concerning telepsychology and subjective norms were associated with intentions to use telepsychology, which related to percentage of clinical work performed via telepsychology. The TAM showed that perceived usefulness of telepsychology and perceived ease of use were associated with attitudes toward telepsychology. Perceived usefulness was associated with psychologists' intention to use telepsychology, as was perceived ease of use., Conclusion: Efforts to facilitate telepsychology provision during the pandemic and broadly may benefit from trainings and campaigns to address attitudes toward telepsychology, subjective norms, and perceived ease of use., (© 2021 Wiley Periodicals LLC.)

Telemedicine use increased during the COVID-19 pandemic, but uptake was uneven and future use is uncertain. This study, then, examined the ability of personal and environmental variables to predict telemedicine adoption during the COVID-19 pandemic. A total of 230 physicians practicing in the U.S. completed questions concerning personal and environmental characteristics, as well as telemedicine use at three time points: pre-pandemic, during the pandemic, and anticipated future use. Associations between use and characteristics were determined to identify factors important for telemedicine use. Physicians reported that telemedicine accounted for 3.72% of clinical work prior to the pandemic, 46.03% during the pandemic, and predicted 25.44% after the pandemic ends. Physicians within hospitals reported less increase in telemedicine use during the pandemic than within group practice ( p = 0.016) and less increase in use at hospitals compared to academic medical centers ( p = 0.027) and group practice ( p = 0.008). Greater telemedicine use was associated with more years in practice ( p = 0.009), supportive organizational policies ( p = 0.001), organizational encouragement ( p = 0.003), expectations of greater patient volume ( p = 0.003), and perceived higher quality of patient care ( p = 0.032). Characteristics such as gender, number of physicians, and level of telemedicine training were not significant predictors. Organizations interested in supporting physicians to adopt telemedicine should encourage its use and create policies supporting its use. More senior physicians had a greater degree of telemedicine uptake, while training programs did not predict use, suggesting that efforts to develop telemedicine competency in younger physicians may be ineffective and should be re-examined.

Study Design: Pre-post study., Objective: To evaluate the efficiency of a series of recruitment strategies in a longitudinal study of individuals with SCI and their informal caregivers. Primary strategies included (a) rapport building in advance, (b) warm handoffs from another healthcare provider who already had a relationship with the potential participant, (c) ensuring the potential participant had information about the study prior to the initial contact by the research coordinator (RC), (d) attempting informed consent only when both the patient and informal caregiver were present, and (e) ensuring the RC had at least 30 minutes to explain the study when attempting recruitment., Summary of Background Data: While a fairly large body of research has been conducted on general recruitment strategies for clinical trials, very little has examined the efficacy of these strategies within neurological conditions and almost none within SCI., Methods: Individuals with an acute SCI and their informal caregivers were recruited from acute spinal cord rehabilitation units with a Veteran's Affairs medical center and an academic medical center in the same urban area. Of 49 eligible dyads, 41 were approached for consent, with 27 consenting to join the study (9 from the academic medical center; 18 from the VA)., Results: There was a significant difference in enrollment rates after implementing the recruitment strategies, χ2(1) = 7.572, P = 0.006, with the per month participant enrollment rate nearly doubling after implementation., Conclusion: Using a multiteam and multidisciplinary approach to recruitment may increase the likelihood that individuals with an acute SCI and their caregivers enroll in research.Level of Evidence: 3., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

An EPR signal for Mn(III) bound to the metal transport protein transferrin has been detected for the first time. The temperature dependence and simulations of the EPR signal are consistent with the Mn(III) centers being six-coordinate in an elongated tetragonal environment. Thus, the incorporation of Mn(III) within the Tf active site does not vastly alter the coordination number or active site geometry relative to native Fe(III) 2 -Tf. This parallel mode EPR signal for Mn(III) 2 -Tf could prove valuable for future studies aimed at determining the physiological relevance of Mn(III) 2 -Tf.

To inculcate biocatalytic activity in the oxygen-storage protein myoglobin (Mb), a genetically engineered myoglobin mutant H64DOPA (DOPA = L-3,4-dihydroxyphenylalanine) has been created. Incorporation of unnatural amino acids has already demonstrated their ability to accomplish many non-natural functions in proteins efficiently. Herein, the presence of redox-active DOPA residue in the active site of mutant Mb presumably stabilizes the compound I in the catalytic oxidation process by participating in an additional hydrogen bonding (H-bonding) as compared to the WT Mb. Specifically, a general acid-base catalytic pathway was achieved due to the availability of the hydroxyl moieties of DOPA. The reduction potential values of WT (E° = -260 mV) and mutant Mb (E° = -300 mV), w.r.t. Ag/AgCl reference electrode, in the presence of hydrogen peroxide, indicated an additional H-bonding in the mutant protein, which is responsible for the peroxidase activity of the mutant Mb. We observed that in the presence of 5 mM H2O2, H64DOPA Mb oxidizes thioanisole and benzaldehyde with a 10 and 54 folds higher rate, respectively, as opposed to WT Mb. Based on spectroscopic, kinetic, and electrochemical studies, we deduce that DOPA residue, when present within the distal pocket of mutant Mb, alone serves the role of His/Arg-pair of peroxidases., (© 2021 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.)

Background: While spinal cord injury (SCI) caregiving can be a rewarding experience, caregivers often experience reduced mental and physical health., Objective: This article describes the methodology of a study examining the efficacy of a newly developed telehealth Transition Assistance Program (TAP) for caregivers of individuals with acute SCI., Methods: A mixed-methods, randomized controlled trial is comparing TAP outcomes to that of a standard-of-care control. The study is recruiting for 48 months and incorporating quantitative outcome measures., Results: This study was funded by the Craig H. Neilsen Foundation in April 2017. It was approved by the institutional review boards at Virginia Commonwealth University and the Hunter Holmes McGuire Veterans Affairs Medical Center that same year. Participant recruitment and data collection began in 2018., Conclusions: This study is implementing and testing an SCI caregiver intervention unlike any created before, targeting a critical time period that, until now, other SCI caregiver interventions have overlooked. Research personnel intend to disseminate the intervention and study findings through the publication of manuscripts and presentations at conferences. If the current study shows improvements in caregiver or patient well-being, the TAP for SCI caregivers could become part of the standard of care for acute SCI., Trial Registration: ClinicalTrials.gov NCT03244098; https://www.clinicaltrials.gov/ct2/show/NCT03244098., International Registered Report Identifier (irrid): DERR1-10.2196/28256., (©Paul B Perrin, Scott D McDonald, Jack D Watson, Bradford S Pierce, Timothy R Elliott. Originally published in JMIR Research Protocols (http://www.researchprotocols.org), 29.03.2021.)

Purpose/Objective: Despite the increasingly high number of individuals who survive burns and the documented impairments in functioning across psychological, work, sexual, and interpersonal domains, there has been a dearth of research investigating connections between pain and functioning in these domains after burn injury. The purpose of the current study was to investigate the relationships among pain, mental health, and functioning of individuals with burn injury. It was hypothesized that pain after burn would yield direct effects on functioning (work, sexual, and interpersonal), as well as indirect effects on functioning through depression and anxiety. Research Method/Design: Eighty-seven individuals with burn injury completed a questionnaire assessing study constructs in an outpatient burn center setting. Results: Pain was positively related to depression and anxiety and inversely related to all three forms of functioning. In a series of mediational models, depression and anxiety simultaneously and partially mediated the relationship between pain and work functioning. Depression fully mediated the relationship between pain and sexual functioning, as well as partially mediated the relationship between pain and interpersonal functioning. The models explained 39.2% of the variance in work functioning, 28.4% in sexual functioning, and 35.6% in interpersonal functioning. Conclusions/Implications: Although the cross-sectional findings are unable to conclude causality, individuals with burn injury experiencing pain may benefit from a biopsychosocial treatment approach while also addressing symptoms of depression and anxiety. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

The COVID-19 pandemic has altered mental health care delivery like no other event in modern history. The purpose of this study was to document the magnitude of that effect by examining (a) the amount of psychologists' telepsychology use before the COVID-19 pandemic, during the pandemic, and anticipated use after the pandemic; as well as (b) the demographic, training, policy, and clinical practice predictors of these changes. This study used a cross-sectional, national online design to recruit 2,619 licensed psychologists practicing in the United States. Prior to the COVID-19 pandemic, psychologists performed 7.07% of their clinical work with telepsychology, which increased 12-fold to 85.53% during the pandemic, with 67.32% of psychologists conducting all of their clinical work with telepsychology. Psychologists projected that they would perform 34.96% of their clinical work via telepsychology after the pandemic. Psychologists working in outpatient treatment facilities reported over a 26-fold increase in telepsychology use during the pandemic, while those in Veterans Affairs medical centers only reported a sevenfold increase. A larger increase in percentage telepsychology use occurred in women, in psychologists who reported an increase in telepsychology training and supportive organizational telepsychology policies, and in psychologists who treated relationship issues, anxiety, and women's issues. The lowest increases in percentage telepsychology use were reported by psychologists working in rural areas, treating antisocial personality disorder, performing testing and evaluation, and treating rehabilitation populations. Although there was a remarkable increase in telepsychology use during the COVID-19 pandemic, individual and practice characteristics affected psychologists' ability to adopt telepsychology. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Thiol dioxygenases are a subset of nonheme iron oxygenases that catalyze the formation of sulfinic acids from sulfhydryl-containing substrates and dioxygen. Among this class, cysteine dioxygenases (CDOs) and 3-mercaptopropionic acid dioxygenases (3MDOs) are the best characterized, and the mode of substrate binding for CDOs is well understood. However, the manner in which 3-mercaptopropionic acid (3MPA) coordinates to the nonheme iron site in 3MDO remains a matter of debate. A model for bidentate 3MPA coordination at the 3MDO Fe-site has been proposed on the basis of computational docking, whereas steady-state kinetics and EPR spectroscopic measurements suggest a thiolate-only coordination of the substrate. To address this gap in knowledge, we determined the structure of Azobacter vinelandii 3MDO (Av3MDO) in complex with the substrate analog and competitive inhibitor, 3-hydroxypropionic acid (3HPA). The structure together with DFT computational modeling demonstrates that 3HPA and 3MPA associate with iron as chelate complexes with the substrate-carboxylate group forming an additional interaction with Arg168 and the thiol bound at the same position as in CDO. A chloride ligand was bound to iron in the coordination site assigned as the O 2 -binding site. Supporting HYSCORE spectroscopic experiments were performed on the (3MPA/NO)-bound Av3MDO iron nitrosyl (S = 3/2) site. In combination with spectroscopic simulations and optimized DFT models, this work provides an experimentally verified model of the Av3MDO enzyme-substrate complex, effectively resolving a debate in the literature regarding the preferred substrate-binding denticity. These results elegantly explain the observed 3MDO substrate specificity, but leave unanswered questions regarding the mechanism of substrate-gated reactivity with dioxygen., Competing Interests: Conflict of interest The authors declare that they have no conflicts of interest with the contents of this article., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

Objectives: The aim of this study was to examine potential racial/ethnic disparities in community integration for the 2 yrs after burn injury., Design: A sample of 1773 adults with burn injury from the Burn Model Systems database was used with data on community integration collected at discharge (preinjury recall), 6, 12, and 24 mos after discharge., Methods: Four sets of hierarchal linear models determined the most appropriate model for understanding racial/ethnic differences in Community Integration Questionnaire trajectories over time., Results: Data indicated a decrease in community integration between discharge and 6 mos, a slight increase between 6 mos and 1 yr, and then a plateau between 1 and 2 yrs. White individuals had higher community integration score trajectories over time than black (b = 0.53, P < 0.001) and Hispanic (b = 0.58, P < 0.001) individuals, and community integration scores were similar between black and Hispanic individuals (b = -0.05, P = 0.788). These racial/ethnic disparities remained after accounting for age, sex, total burned surface area, number of days in rehabilitation, and active range of motion deficits., Conclusions: Additional rehabilitation resources should be targeted to helping black and Hispanic individuals integrate back into their communities after burn injury.

Competing Interests: The authors report no conflicts of interest.

Objective: This article positions the special issue on telepsychology amidst the COVID-19 pandemic, which has dramatically accelerated the adoption and dissemination of telepsychology., Method: The article makes general observations about the themes emerging in the special issue with considerations for application, training, theory-driven research, and policy. It then presents as a case example the rapid deployment during the pandemic of telepsychology doctoral training and services at the Virginia Commonwealth University (VCU) Primary Care Psychology Collaborative., Results: Facilitators to VCU telepsychology deployment included trainee and supervisor resources, strong telepsychology training, and prior experience. Barriers to overcome included limited clinic capacity, scheduling, technology, and accessibility and diversity issues. Lessons learned involved presenting clinical issues, supervision, and working with children and adolescents., Conclusions: Telepsychology is crucial for psychological service provision, during the COVID-19 pandemic more than ever, and that is unlikely to change as psychologists and patients increasingly continue to appreciate its value., (© 2020 Wiley Periodicals LLC.)

Objective: To examine whether the Theory of Reasoned Action (TRA) and Technology Acceptance Model (TAM) apply to psychologists' openness to using telepsychology., Method: Participants were 1,791 psychologists currently practicing psychotherapy. Participants represented all 50 US states and averaged 26.33 (SD = 11.18) years in clinical practice. The study used a cross-sectional, national online design., Results: Path analyses derived from the TRA and TAM evidenced poor fit. A newly-developed, third model achieved adequate to fit in which perceived attitudes of others concerning telepsychology were associated with perceived ease of use (β = 0.25, p < .001) and usefulness (β = 0.30, p < .001) of telepsychology. Perceived ease of use (β = 0.30, p < .001) and usefulness (β = 0.32, p < .001) of telepsychology both uniquely predicted current use of telepsychology., Conclusions: Organizations should adopt methods for delivering telepsychology that are easy to use and possess demonstrable utility., (© 2019 Wiley Periodicals, Inc.)

Herein, we disclose a new series of TYK2/ JAK1 inhibitors based upon a 3.1.0 azabicyclic substituted pyrimidine scaffold. We illustrate the use of structure-based drug design for the initial design and subsequent optimization of this series of compounds. One advanced example 19 met program objectives for potency, selectivity and ADME, and demonstrated oral activity in the adjuvant-induced arthritis rat model., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

The catalase family of enzymes, which include a variety with a binuclear manganese active site, mitigate the risk from reactive oxygen species by facilitating the disproportionation of hydrogen peroxide into molecular oxygen and water. In this work, hydrogen peroxide disproportionation using complexes formed between manganese and cyclen or pyclen were investigated due to the spectroscopic similarities with the native MnCAT enzyme. Potentiometric titrations were used to construct speciation diagrams that identify the manganese complex compositions at different pH values. Each complex behaves as a functional mimic of catalase enzymes. UV-visible spectroscopic investigations of the H 2 O 2 decomposition reaction yielded information about the structure of the initial catalyst and intermediates that include monomeric and dimeric species. The results indicate that rigidity imparted by the pyridine ring of pyclen is a key factor in increased TON and TOF values measured compared to cyclen., Competing Interests: Conflicts of interest There are no conflicts to declare.

Benzimidazoles are common in nature, medicines, and materials. Numerous strategies for preparing 2-arylbenzimidazoles exist. In this work, 1,2-disubstituted benzimidazoles were prepared from various mono- and disubstituted ortho -phenylenediamines (OPD) by iron-catalyzed oxidative coupling. Specifically, O 2 and FeCl 3 ·6H 2 O catalyzed the cross-dehydrogenative coupling and aromatization of diarylmethyl and dialkyl benzimidazole precursors. N , N '-Disubstituted-OPD substrates were significantly more reactive than their N , N -disubstituted isomers, which appears to be relative to their propensity for complexation and charge transfer with Fe 3+ . The reaction also converted N-monosubstituted OPD substrates to 2-substituted benzimidazoles; however, electron-poor substrates produce 1,2-disubstituted benzimidazoles by intermolecular imino-transfer. Kinetic, reagent, and spectroscopic (UV-vis and EPR) studies suggest a mechanism involving metal-substrate complexation, charge transfer, and aerobic turnover, involving high-valent Fe(IV) intermediates. Overall, comparative strategies for the relatively sustainable and efficient synthesis of 1,2-disubstituted benzimidazoles are demonstrated.

Thiol dioxygenases are non-heme mononuclear iron enzymes that catalyze the O 2 -dependent oxidation of free thiols (-SH) to produce the corresponding sulfinic acid (-SO 2 - ). Regardless of the phylogenic domain, the active site for this enzyme class is typically comprised of two major features: (1) a mononuclear ferrous iron coordinated by three protein-derived histidines and (2) a conserved sequence of outer Fe-coordination-sphere amino acids (Ser-His-Tyr) spatially adjacent to the iron site (∼3 Å). Here, we utilize a promiscuous 3-mercaptopropionic acid dioxygenase cloned from Azotobacter vinelandii ( Av MDO) to explore the function of the conserved S-H-Y motif. This enzyme exhibits activity with 3-mercaptopropionic acid ( 3mpa ), l-cysteine ( cys ), as well as several other thiol-bearing substrates, thus making it an ideal system to study the influence of residues within the highly conserved S-H-Y motif (H157 and Y159) on substrate specificity and reactivity. The p K a values for these residues were determined by pH-dependent steady-state kinetics, and their assignments verified by comparison to H157N and Y159F variants. Complementary electron paramagnetic resonance and Mössbauer studies demonstrate a network of hydrogen bonds connecting H157-Y159 and Fe-bound ligands within the enzymatic Fe site. Crucially, these experiments suggest that the hydroxyl group of Y159 hydrogen bonds to Fe-bound NO and, by extension, Fe-bound oxygen during native catalysis. This interaction alters both the NO binding affinity and rhombicity of the 3mpa -bound iron-nitrosyl site. In addition, Fe coordination of cys is switched from thiolate only to bidentate (thiolate/amine) for the Y159F variant, indicating that perturbations within the S-H-Y proton relay network also influence cys Fe binding denticity.

Because of the importance of hydrogen atom transfer (HAT) in biology and chemistry, there is increased interest in new strategies to perform HAT in a sustainable manner. Here, we describe a sustainable, net redox-neutral HAT process involving hydrosilanes and alkali metal Lewis base catalysts - eliminating the use of transition metal catalysts - and report an associated mechanism concerning Lewis base-catalysed, complexation-induced HAT (LBCI-HAT). The catalytic LBCI-HAT is capable of accessing both branch-specific hydrosilylation and polymerization of vinylarenes in a highly selective fashion, depending on the Lewis base catalyst used. In this process, earth abundant, alkali metal Lewis base catalyst plays a dual role. It first serves as a HAT initiator and subsequently functions as a silyl radical stabilizing group, which is critical to highly selective cross-radical coupling. EPR study identified a potassiated paramagnetic species and multistate density function theory revealed a high HAT character, yet multiconfigurational nature in the transition state of the reaction.

N-Alkyl and N-aryl-isoindolinones were prepared by a dioxane-mediated oxidation of isoindoline precursors. The transformation exhibits unique chemoselectivity for isoindonlines. A chiral tertiary (3°)-benzylic position was not racemized during oxidation, and methyl indoprofen was prepared by late stage oxidation. Mechanistic studies suggest a selective H atom transfer, which avoids many known oxidation (by-)products of isoindolinones.

The nitrosylated diiron complexes, Fe 2 (NO) 3 , of this study are interpreted as a mono-nitrosyl Fe(NO) unit, MNIU, within an N 2 S 2 ligand field that serves as a metallodithiolate ligand to a dinitrosyl iron unit, DNIU. The cationic Fe(NO)N 2 S 2 ⋅Fe(NO) 2 + complex, 1 + , of Enemark-Feltham electronic notation {Fe(NO)} 7 -{Fe(NO) 2 } 9 , is readily obtained via myriad synthetic routes, and shown to be spin coupled and diamagnetic. Its singly and doubly reduced forms, {Fe(NO)} 7 -{Fe(NO) 2 } 10 , 1 0 , and {Fe(NO)} 8 -{Fe(NO) 2 } 10 , 1 - , were isolated and characterized. While structural parameters of the DNIU are largely unaffected by redox levels, the MNIU readily responds; the neutral, S= 1 / 2 , complex, 1 0 , finds the extra electron density added into the DNIU affects the adjacent MNIU as seen by the decrease its Fe-N-O angle (from 171° to 149°). In contrast, addition of the second electron, now into the MNIU, returns the Fe-N-O angle to 171° in 1 - . Compensating shifts in Fe MNIU distances from the N 2 S 2 plane (from 0.518 to 0.551 to 0.851 Å) contribute to the stability of the bimetallic complex. These features are addressed by computational studies which indicate that the MNIU in 1 - is a triplet-state {Fe(NO)} 8 with strong spin polarization in the more linear FeNO unit. Magnetic susceptibility and parallel mode EPR results are consistent with the triplet state assignment., (© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Cytokine signaling is an important characteristic of autoimmune diseases. Many pro-inflammatory cytokines signal through the Janus kinase (JAK)/Signal transducer and activator of transcription (STAT) pathway. JAK1 is important for the γ-common chain cytokines, interleukin (IL)-6, and type-I interferon (IFN) family, while TYK2 in addition to type-I IFN signaling also plays a role in IL-23 and IL-12 signaling. Intervention with monoclonal antibodies (mAbs) or JAK1 inhibitors has demonstrated efficacy in Phase III psoriasis, psoriatic arthritis, inflammatory bowel disease, and rheumatoid arthritis studies, leading to multiple drug approvals. We hypothesized that a dual JAK1/TYK2 inhibitor will provide additional efficacy, while managing risk by optimizing selectivity against JAK2 driven hematopoietic changes. Our program began with a conformationally constrained piperazinyl-pyrimidine Type 1 ATP site inhibitor, subsequent work led to the discovery of PF-06700841 (compound 23), which is in Phase II clinical development (NCT02969018, NCT02958865, NCT03395184, and NCT02974868).

Superoxide overproduction is known to occur in multiple disease states requiring critical care; yet, noninvasive detection of superoxide in deep tissue remains a challenge. Herein, we report a metal-free magnetic resonance imaging (MRI) and electron paramagnetic resonance (EPR) active contrast agent prepared by "click conjugating" paramagnetic organic radical contrast agents (ORCAs) to the surface of tobacco mosaic virus (TMV). While ORCAs are known to be reduced in vivo to an MRI/EPR silent state, their oxidation is facilitated specifically by reactive oxygen species-in particular, superoxide-and are largely unaffected by peroxides and molecular oxygen. Unfortunately, single molecule ORCAs typically offer weak MRI contrast. In contrast, our data confirm that the macromolecular ORCA-TMV conjugates show marked enhancement for T 1 contrast at low field (<3.0 T) and T 2 contrast at high field (9.4 T). Additionally, we demonstrated that the unique topology of TMV allows for a "quenchless fluorescent" bimodal probe for concurrent fluorescence and MRI/EPR imaging, which was made possible by exploiting the unique inner and outer surface of the TMV nanoparticle. Finally, we show TMV-ORCAs do not respond to normal cellular respiration, minimizing the likelihood for background, yet still respond to enzymatically produced superoxide in complicated biological fluids like serum.

This study showcases the potential of unnatural amino acids to enable non-natural functions when incorporated in the protein scaffold of heme metalloproteins. For this purpose, a genetically-engineered myoglobin (Mb) mutant was created by incorporating redox-active 3-amino-l-tyrosine (NH 2 Tyr) into its active site, replacing the distal histidine (H64) with NH 2 Tyr. In peroxide-shunt assays, this variant exhibits an increased rate of turnover for thioanisole and benzaldehyde oxidation as compared to the wild-type (WT) Mb. Indeed, in the presence of excess hydrogen peroxide (H 2 O 2 ), a 9-fold and 81-fold increase in activity was observed over multiple turnovers for thioanisole sulfoxidation and benzoic acid formation, respectively. The increased oxidation activity in the H64NH 2 Tyr Mb mutant underlined the role of NH 2 Tyr in the distal active-site scaffold in peroxide activation. Kinetic, electrochemical, and EPR spectroscopic experiments were performed. On the basis of these studies, it is argued that the single NH 2 Tyr residue within the Mb variant simultaneously serves the role of the conserved His/Arg-pair within the distal pocket of horseradish peroxidase., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Biochemical screening is a major source of lead generation for novel targets. However, during the process of small molecule lead optimization, compounds with excellent biochemical activity may show poor cellular potency, making structure-activity relationships difficult to decipher. This may be due to low membrane permeability of the molecule, resulting in insufficient intracellular drug concentration. The Cell Squeeze platform increases permeability regardless of compound structure by mechanically disrupting the membrane, which can overcome permeability limitations and bridge the gap between biochemical and cellular studies. In this study, we show that poorly permeable Janus kinase (JAK) inhibitors are delivered into primary cells using Cell Squeeze, inhibiting up to 90% of the JAK pathway, while incubation of JAK inhibitors with or without electroporation had no significant effect. We believe this robust intracellular delivery approach could enable more effective lead optimization and deepen our understanding of target engagement by small molecules and functional probes.

Objectives: To use latent growth curve and longitudinal structural equation modeling to examine the 2-year trajectory of satisfaction with appearance in adults with burn injury, and that trajectory's effect on depression 5 years after burn injury., Design: Data were collected at discharge after burn injury hospitalization and at 6 months, 1 year, 2 years, and 5 years postdischarge., Setting: The Burn Model Systems (BMS) program consisted of a data center and 5 participating burn centers., Participants: The sample consisted of adults (N=720) who were hospitalized for a burn injury, enrolled in the BMS database, and completed measures at least once throughout the 5-year study duration., Interventions: Not applicable., Main Outcome Measures: Satisfaction With Appearance Scale and Patient Health Questionnaire-9 (depression)., Results: Women with burn injury reported higher levels of dissatisfaction with their appearance in comparison to their male counterparts over the 2 years after discharge. Individuals with a larger total body surface area (TBSA) affected by a burn also reported greater body dissatisfaction across the postdischarge 2-year period. Results did not support significant gender or TBSA differences in the rate of change of body dissatisfaction trajectories across these 2 years. Individuals with greater body dissatisfaction at 6 months postdischarge tended to have higher depressive symptoms at 5 years. Six month postdischarge, body dissatisfaction scores also mediated the effects of gender and TBSA on depressive symptoms 5 years later., Conclusions: It is recommended that individuals with heightened body image dissatisfaction after a burn, particularly women and those with larger TBSA, participate in evidence-based psychosocial interventions to improve long-term adjustment., (Copyright © 2017 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.)

Ovotransferrin (OTf), the major protein constituent of egg white, is of great interest due to its pivotal role in biological iron transport and storage processes and its spontaneous autocleavage into peptidic fragments with alternative biological properties, such as antibacterial and antioxidant activities. However, despite being well-investigated in avian, a detailed elucidation of the structure-function relationship of ovotransferrins in the closely related order of Crocodilia has not been reported to date. In this study, electron paramagnetic resonance (EPR) confirmed the presence of two spectroscopically distinct ferric iron binding sites in Crocodylus siamensis OTf (cOTf), but implied a five-fold lower quantity of bound iron than in hen OTf (hOTf). In addition, quantitative estimation of free sulfhydryl groups revealed slight differences to hOTf. To gain a better structural understanding of cOTf, we found a cOTf gene consisting of an open reading frame of 2040bp and encoding a protein of 679 amino acids. In silico prediction of the three-dimensional structure of cOTf and comparison with hOTf revealed four evolutionarily conserved iron-binding sites in both N- and C-lobes, as well as the presence of only 13 of the 15 disulfide bonds in hOTf. This evolutionary loss of disulfide linkages in conjunction with the lack of hydrogen bonding from a dilysine trigger in the C-lobe are presumed to affect the iron binding and autocleavage character of cOTf. As a result, cOTf may be capable of exerting a more diverse array of functions compared to its avian counterparts; for instance, ion buffering, antioxidant and antimicrobial activities., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Thiol dioxygenases are non-heme mononuclear iron enzymes that catalyze the O 2 -dependent oxidation of free thiols (-SH) to produce the corresponding sulfinic acid (-SO 2 - ). Previous chemical rescue studies identified a putative Fe III -O 2 - intermediate that precedes substrate oxidation in Mus musculus cysteine dioxygenase (Mm CDO). Given that a similar reactive intermediate has been identified in the extradiol dioxygenase 2, 3-HCPD, it is conceivable that these enzymes share other mechanistic features with regard to substrate oxidation. To explore this possibility, enzymatic reactions with Mm CDO (as well as the bacterial 3-mercaptopropionic acid dioxygenase, Av MDO) were performed using a substrate analogue (2-mercaptoaniline, 2ma). This aromatic thiol closely approximates the catecholic substrate of homoprotocatechuate of 2, 3-HPCD while maintaining the 2-carbon thiol-amine separation preferred by Mm CDO. Remarkably, both enzymes exhibit 2ma-gated O 2 -consumption; however, none of the expected products for thiol dioxygenase or intra/extradiol dioxygenase reactions were observed. Instead, benzothiazoles are produced by the condensation of 2ma with aldehydes formed by an off-pathway oxidation of primary alcohols added to aqueous reactions to solubilize the substrate. The observed oxidation of 1º-alcohols in 2ma-reactions is consistent with the formation of a high-valent intermediate similar to what has been reported for cytochrome P450 and mononuclear iron model complexes., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Through fragment-based drug design focused on engaging the active site of IRAK4 and leveraging three-dimensional topology in a ligand-efficient manner, a micromolar hit identified from a screen of a Pfizer fragment library was optimized to afford IRAK4 inhibitors with nanomolar potency in cellular assays. The medicinal chemistry effort featured the judicious placement of lipophilicity, informed by co-crystal structures with IRAK4 and optimization of ADME properties to deliver clinical candidate PF-06650833 (compound 40). This compound displays a 5-unit increase in lipophilic efficiency from the fragment hit, excellent kinase selectivity, and pharmacokinetic properties suitable for oral administration.

3-mercaptopropionate dioxygenase from Azotobacter vinelandii (Av MDO) is a non-heme mononuclear iron enzyme that catalyzes the O2-dependent oxidation of 3-mercaptopropionate (3mpa) to produce 3-sulfinopropionic acid (3spa). With one exception, the active site residues of MDO are identical to bacterial cysteine dioxygenase (CDO). Specifically, the CDO Arg-residue (R50) is replaced by Gln (Q67) in MDO. Despite this minor active site perturbation, substrate-specificity of Av MDO is more relaxed as compared to CDO. In order to investigate the relative timing of chemical and non-chemical events in Av MDO catalysis, the pH/D-dependence of steady-state kinetic parameters (kcat and kcat/KM) and viscosity effects are measured using two different substrates [3mpa and l-cysteine (cys)]. The pL-dependent activity of Av MDO in these reactions can be rationalized assuming a diprotic enzyme model in which three ionic forms of the enzyme are present [cationic, E((z+1)); neutral, E(z); and anionic, E((z-1))]. The activities observed for each substrate appear to be dominated by electrostatic interactions within the enzymatic active site. Given the similarity between MDO and the more extensively characterized mammalian CDO, a tentative model for the role of the conserved 'catalytic triad' is proposed., (Copyright © 2016 Elsevier Inc. All rights reserved.)

The purpose of this study was to investigate among college students the relationship between personality traits and willingness to care for a relative with a chronic health condition. 329 undergraduate students completed an online questionnaire. Hierarchical multiple regressions found that after controlling for demographics personality traits explained 10% of the variance in willingness to provide emotional care, 7% in instrumental care, and 7% in nursing care. Within these models, greater empathy was uniquely associated with willingness to provide emotional, instrumental, and nursing care for a family member in the future. Similarly, participants with high agreeableness were more willing to provide emotional care, and participant older age was a unique predictor of instrumental care. The results can help shape research on interventions that incorporate perspective taking, motivational interviewing, and training in life skills as a means of boosting college students' willingness to provide care for a relative with a chronic health condition.

Cysteine dioxygenase (CDO) is a non-heme iron enzyme that catalyzes the O2-dependent oxidation of l-cysteine to produce cysteinesulfinic acid. Bacterial CDOs have been subdivided as either "Arg-type" or "Gln-type" on the basis of the identity of conserved active site residues. To date, "Gln-type" enzymes remain largely uncharacterized. It was recently noted that the "Gln-type" enzymes are more homologous with another thiol dioxygenase [3-mercaptopropionate dioxygenase (MDO)] identified in Variovorax paradoxus, suggesting that enzymes of the "Gln-type" subclass are in fact MDOs. In this work, a putative "Gln-type" thiol dioxygenase from Azotobacter vinelandii (Av) was purified to homogeneity and characterized. Steady-state assays were performed using three substrates [3-mercaptopropionic acid (3mpa), l-cysteine (cys), and cysteamine (ca)]. Despite comparable maximal velocities, the "Gln-type" Av enzyme exhibited a specificity for 3mpa (kcat/KM = 72000 M(-1) s(-1)) nearly 2 orders of magnitude greater than those for cys (110 M(-1) s(-1)) and ca (11 M(-1) s(-1)). Supporting X-band electron paramagnetic resonance (EPR) studies were performed using nitric oxide (NO) as a surrogate for O2 binding to confirm obligate-ordered addition of substrate prior to NO. Stoichimetric addition of NO to solutions of 3mpa-bound enzyme quantitatively yields an iron-nitrosyl species (Av ES-NO) with EPR features consistent with a mononuclear (S = (3)/2) {FeNO}(7) site. Conversely, two distinct substrate-bound conformations were observed in Av ES-NO samples prepared with cys and ca, suggesting heterogeneous binding within the enzymatic active site. Analytical EPR simulations are provided to establish the relative binding affinity for each substrate (3map > cys > ca). Both kinetic and spectroscopic results presented here are consistent with 3mpa being the preferred substrate for this enzyme.

MiaE [2-methylthio-N(6)-isopentenyl-adenosine(37)-tRNA monooxygenase] isolated from Salmonella typhimurium is a unique non-heme diiron enzyme that catalyzes the O2-dependent post-transcriptional allylic hydroxylation of a hypermodified nucleotide (ms(2)i(6)A37) at position 37 of selected tRNA molecules to produce 2-methylthio-N(6)-(4-hydroxyisopentenyl)-adenosine(37). In this work, isopentenylated tRNA substrates for MiaE were produced from small RNA oligomers corresponding to the anticodon stem loop (ACSL) region of tRNA(Trp) using recombinant MiaA and dimethylallyl pyrophosphate. Steady-state rates for MiaE-catalyzed substrate hydroxylation were determined using recombinant ferredoxin (Fd) and ferredoxin reductase (FdR) to provide a catalytic electron transport chain (ETC) using NADPH as the sole electron source. As with previously reported peroxide-shunt assays, steady-state product formation retains nearly stoichiometric (>98%) E stereoselectivity. MiaE-catalyzed i(6)A-ACSL(Trp) hydroxylation follows Michaelis-Menten saturation kinetics with kcat, KM, and V/K determined to be 0.10 ± 0.01 s(-1), 9.1 ± 1.5 μM, and ∼11000 M(-1) s(-1), respectively. While vastly slower, MiaE-catalyzed hydroxylation of free i(6)A nucleoside could also be observed using the (Fd/FdR)-ETC assay. By comparison to the V/K determined for i(6)A-ACSL substrates, an ∼6000-fold increase in enzymatic efficiency is imparted by ACSL(Trp)-MiaE interactions. The impact of substrate tRNA-MiaE interactions on protein secondary structure and active site electronic configuration was investigated using circular dichroism, dual-mode X-band electron paramagnetic resonance, and Mössbauer spectroscopies. These studies demonstrate that binding of tRNA to MiaE induces a protein conformational change that influences the electronic structure of the diiron site analogous to what has been observed for various bacterial multicomponent diiron monooxygenases upon titration with their corresponding effector proteins. These observations suggest that substrate-enzyme interactions may play a pivotal role in modulating the reactivity of the MiaE diiron active site. Moreover, the simplified monomeric (α) protein configuration exhibited by MiaE provide an unparalleled opportunity to study the impact of protein-effector interactions on non-heme diiron site geometry and reactivity.

Cysteine dioxygenase (CDO) is a non-heme mononuclear iron enzyme that catalyzes the oxygen-dependent oxidation of L-cysteine (Cys) to produce L-cysteine sulfinic acid (CSA). Sequence alignment of mammalian CDO with recently discovered thiol dioxygenase enzymes suggests that the mononuclear iron site within all enzymes in this class share a common 3-His first coordination sphere. This implies a similar mechanistic paradigm among thiol dioxygenase enzymes. Although steady-state studies were first reported for mammalian CDO over 45 years ago, detailed analysis of the specificity for alternative thiol-bearing substrates and their oxidative coupling efficiencies have not been reported for this enzyme. Assuming a similar mechanistic theme among this class of enzymes, characterization of the CDO substrate specificity may provide valuable insight into substrate-active site intermolecular during thiol oxidation. In this work, the substrate-specificity for wild-type Mus musculus CDO was investigated using NMR spectroscopy and LC-MS for a variety of thiol-bearing substrates. Tandem mass spectrometry was used to confirm dioxygenase activity for each non-native substrate investigated. Steady-state Michaelis-Menten parameters for sulfinic acid product formation and O₂-consumption were compared to establish the coupling efficiency for each reaction. In light of these results, the minimal substrate requirements for CDO catalysis and O₂-activation are discussed., (Copyright © 2014 Elsevier Inc. All rights reserved.)