Light adjustable intraocular lenses: an updated platform for cataract surgery.

PURPOSE OF REVIEW: Light adjustable intraocular lenses (LALs) are a relatively new platform for cataract surgery that is shifting the paradigm for intraocular lens placement following cataract removal. RECENT FINDINGS: LALs may have additional utility in patients with prior refractive surgery and complex ocular conditions, as they give the surgeon greater latitude in preoperative intraocular power calculations to meet postoperative refractive goals. SUMMARY: Further study of best candidates for LALs is warranted. Current best candidates are patients who can comply with treatment and have decreased accuracy in calculating the preoperative intraocular power requirement.

Oriented Electrostatic Effects on O2 and CO2 Reduction by a Polycationic Iron Porphyrin.

Next-generation energy technologies require improved methods for rapid and efficient chemical-to-electrical energy transformations. One new approach has been to include atomically positioned, electrostatic motifs in molecular catalysts to stabilize high-energy, charged intermediates. For example, an iron porphyrin bearing four cationic, o-N,N,N-trimethylanilinium groups (o-[N(CH3)3]+) has recently been used to catalyze the complex, multistep O2 and CO2 reduction reactions (ORR and CO2RR) with fast rates and at low overpotentials. The success of this catalyst is attributed, at least in part, to specific charge-charge interactions between the atomically positioned o-[N(CH3)3]+ groups and the bound substrate. However, by nature of the mono-ortho substitution pattern, there are four possible atropisomers of this metalloporphyrin and thus four unique electrostatic environments. This work reports that each of the four individual atropisomers catalyzes both the ORR and CO2RR with fast rates and low overpotentials. The maximum turnover frequencies vary among the atropisomers, by a factor of 60 for the ORR and a factor of 5 for CO2RR. For the ORR, the αßαß isomer is the fastest and has the highest overpotential, while for the CO2RR the αααα isomer is the fastest and has the highest overpotential. The role of charge positioning is complex and can affect more than a single step such as CO2 binding. These data offer a first-of-a-kind perspective on atomically positioned charge and highlight the significance of high charge density, rather than orientation, on the thermodynamics and kinetics of multistep molecular electrochemical transformations.

Developing Scaling Relationships for Molecular Electrocatalysis through Studies of Fe-Porphyrin-Catalyzed O2 Reduction.

The oxygen reduction reaction (ORR) is a multiproton/multielectron transformation in which dioxygen (O2) is reduced to water or hydrogen peroxide and serves as the cathode reaction in most fuel cells. The ORR (O2 + 4e- + 4H+ → 2H2O) involves up to nine substrates and thus requires navigating a complicated reaction landscape, typically with several high-energy intermediates. Many catalysts can perform this reaction, though few operate with fast rates and at low overpotentials (close to the thermodynamic potential). Attempts to optimize these parameters, both in homogeneous and heterogeneous electrocatalytic systems, have focused on modifying catalyst design and understanding kinetic/thermodynamic relationships between catalytic intermediates. One such method for analyzing and predicting catalyst reactivity and efficiency has been the development of "molecular scaling relationships". Here, we share our experience deriving and utilizing molecular scaling relationships for soluble, iron-porphyrin-catalyzed O2 reduction in organic solvents. These relationships correlate turnover frequencies (TOFmax) and effective overpotentials (ηeff), properties uniquely defined for homogeneous catalysts. Following a general introduction of scaling relationships for both homogeneous and heterogeneous electrocatalysis, we describe the components of such scaling relationships: (i) the overall thermochemistry of the reaction and (ii) the rate and rate law of the catalyzed reaction. We then show how connecting these thermodynamic and kinetic parameters reveals multiple molecular scaling relationships for iron-porphyrin-catalyzed O2 reduction. For example, the log(TOFmax) responds steeply to changes in ηeff that result from different catalyst reduction potentials (18.5 decades in TOFmax/V in ηeff) but much less dramatically to changes in ηeff that arise from varying the pKa of the acid buffer (5.1 decades in TOFmax/V in ηeff). Thus, a single scaling relationship is not always sufficient for describing molecular electrocatalysis. This is particularly evident when the catalyst identity and reaction conditions are coupled. Using these multiple scaling relationships, we demonstrate that the metrics of turnover frequency and effective overpotential can be predictably tuned to achieve faster rates at lowered overpotentials. This Account uses a collection of related stories describing our research on soluble iron-porphyrin-catalyzed ORR to show how molecular scaling relationships can be derived and used for any electrocatalytic reaction. Such scaling relationships are powerful tools that connect the thermochemistry, mechanism, and rate law for a catalytic system. We hope that this collection shows the utility and simplicity of the molecular scaling approach for understanding catalysis, for enabling direct comparisons between catalyst systems, and for optimizing catalytic processes.

All Four Atropisomers of Iron Tetra(o-N,N,N-trimethylanilinium)porphyrin in Both the Ferric and Ferrous States.

Electrostatic effects are key to many biological and (electro)chemical transformations, especially those that involve charged species. The position and orientation of the electric field with respect to the molecules undergoing charge rearrangement are often crucial to the progress of the reaction. Recently, several molecular (electro)catalysts have been designed to contain spatially positioned charged groups that can engage in specific intramolecular electrostatic interactions. For instance, iron complexes of the tetra(o-N,N,N-trimethylanilinium)porphyrin ligand, which has four cationic groups, have been used to great effect for both CO2 and O2 reduction. Because of the ortho-substitution pattern on the porphyrin ligand, there are four possible atropisomers-such as the αßαß isomer with trimethylanilinium groups on alternating faces of the porphyrin-and thus four unique electrostatic environments. This study details the synthesis and characterization (1H NMR spectroscopy, single crystal X-ray diffraction, and cyclic voltammetry) of these four metalloporphyrin isomers in both the ferric (FeIII) and ferrous (FeII) forms by using a synthetic route that preserves atropisomeric purity. The atropisomers are different in some respects but show remarkable similarities in others, such as their reduction potentials. This study also shows that the widely-cited literature method used previously to prepare the molecular electrocatalyst for CO2 and O2 reduction yields a mixture of atropisomers rather than a single one, as was previously assumed. These results identify the ways in which intra- and intermolecular electrostatic effects affect both solution and solid-state properties as well underscoring the challenges associated with preparing metalloporphyrins with high atropisomeric purity.

Intramolecular Electrostatic Effects on O2, CO2, and Acetate Binding to a Cationic Iron Porphyrin.

Noncovalent electrostatic interactions are important in many biological and chemical reactions, especially those that involve charged intermediates. There has been a growing interest in using electrostatic ligand designs-placing charges in the second coordination sphere-to improve molecular reactivity, catalysis, and electrocatalysis. For instance, an iron porphyrin bearing four cationic ortho-trimethylanilinium groups, Fe(o-TMA), has been reported to be an exceptional electrocatalyst for both the carbon dioxide reduction reaction (CO2RR) and the oxygen reduction reaction (ORR). These reactions involve many different steps, and it is not evident which steps are affected by the four positive charges, or why. By comparing Fe(o-TMA) with the related iron-tetraphenylporphyrin, this work examines how covalently positioned charged groups affect substrate binding and other key pre-equilibria of both the ORR and CO2RR, specifically acetate, dioxygen, and carbon dioxide binding. This study is among the first to directly measure the effects of electrostatics on ligand-binding. The results show that adding electrostatic groups to a catalyst design often results in a complex interplay of multiple effects, including changes in pre-equilibria prior to substrate binding, combinations of through-space and inductive contributions, and effects of ionic strength and solution dielectric. The inverse half-order dependence of binding constant on ionic strength is proposed as a clear marker for an electrostatic effect. The conclusions provide guidance for the increasingly popular electrostatic ligand designs in catalysis and other reactivity.

Oxygen Reduction by Homogeneous Molecular Catalysts and Electrocatalysts.

The oxygen reduction reaction (ORR) is a key component of biological processes and energy technologies. This Review provides a comprehensive report of soluble molecular catalysts and electrocatalysts for the ORR. The precise synthetic control and relative ease of mechanistic study for homogeneous molecular catalysts, as compared to heterogeneous materials or surface-adsorbed species, enables a detailed understanding of the individual steps of ORR catalysis. Thus, the Review places particular emphasis on ORR mechanism and thermodynamics. First, the thermochemistry of oxygen reduction and the factors influencing ORR efficiency are described to contextualize the discussion of catalytic studies that follows. Reports of ORR catalysis are presented in terms of their mechanism, with separate sections for catalysis proceeding via initial outer- and inner-sphere electron transfer to O2. The rates and selectivities (for production of H2O2 vs H2O) of these catalysts are provided, along with suggested methods for accurately comparing catalysts of different metals and ligand scaffolds that were examined under different experimental conditions.

Mechanism of Catalytic O2 Reduction by Iron Tetraphenylporphyrin.

The catalytic reduction of O2 to H2O is important for energy transduction in both synthetic and natural systems. Herein, we report a kinetic and thermochemical study of the oxygen reduction reaction (ORR) catalyzed by iron tetraphenylporphyrin (Fe(TPP)) in N, N'-dimethylformamide using decamethylferrocene as a soluble reductant and para-toluenesulfonic acid ( pTsOH) as the proton source. This work identifies and characterizes catalytic intermediates and their thermochemistry, providing a detailed mechanistic understanding of the system. Specifically, reduction of the ferric porphyrin, [FeIII(TPP)]+, forms the ferrous porphyrin, FeII(TPP), which binds O2 reversibly to form the ferric-superoxide porphyrin complex, FeIII(TPP)(O2•-). The temperature dependence of both the electron transfer and O2 binding equilibrium constants has been determined. Kinetic studies over a range of concentrations and temperatures show that the catalyst resting state changes during the course of each catalytic run, necessitating the use of global kinetic modeling to extract rate constants and kinetic barriers. The rate-determining step in oxygen reduction is the protonation of FeIII(TPP)(O2•-) by pTsOH, which proceeds with a substantial kinetic barrier. Computational studies indicate that this barrier for proton transfer arises from an unfavorable preassociation of the proton donor with the superoxide adduct and a transition state that requires significant desolvation of the proton donor. Together, these results are the first example of oxygen reduction by iron tetraphenylporphyrin where the pre-equilibria among ferric, ferrous, and ferric-superoxide intermediates have been quantified under catalytic conditions. This work gives a generalizable model for the mechanism of iron porphyrin-catalyzed ORR and provides an unusually complete mechanistic study of an ORR reaction. More broadly, this study also highlights the kinetic challenges for proton transfer to catalytic intermediates in organic media.

Synthesis and Prior Misidentification of 4-tert-Butyl-2,6-dinitrobenzaldehyde.

Substituted 2,6-dinitrobenzaldehydes are valuable synthetic precursors and have been prepared by several methods. We report here that one reported synthetic method actually forms the 3,5-dinitro isomer, 4-tert-butyl-3,5-dinitrobenzaldehyde, instead of the claimed 2,6-isomer, 4-tert-butyl-2,6-dinitrobenzaldehyde. Improved syntheses for the large-scale preparation of both compounds and their single-crystal X-ray structures are described.

Rational Design of Mononuclear Iron Porphyrins for Facile and Selective 4e-/4H+ O2 Reduction: Activation of O-O Bond by 2nd Sphere Hydrogen Bonding.

Facile and selective 4e-/4H+ electrochemical reduction of O2 to H2O in aqueous medium has been a sought-after goal for several decades. Elegant but synthetically demanding cytochrome c oxidase mimics have demonstrated selective 4e-/4H+ electrochemical O2 reduction to H2O is possible with rate constants as fast as 105 M-1 s-1 under heterogeneous conditions in aqueous media. Over the past few years, in situ mechanistic investigations on iron porphyrin complexes adsorbed on electrodes have revealed that the rate and selectivity of this multielectron and multiproton process is governed by the reactivity of a ferric hydroperoxide intermediate. The barrier of O-O bond cleavage determines the overall rate of O2 reduction and the site of protonation determines the selectivity. In this report, a series of mononuclear iron porphyrin complexes are rationally designed to achieve efficient O-O bond activation and site-selective proton transfer to effect facile and selective electrochemical reduction of O2 to water. Indeed, these crystallographically characterized complexes accomplish facile and selective reduction of O2 with rate constants >107 M-1 s-1 while retaining >95% selectivity when adsorbed on electrode surfaces (EPG) in water. These oxygen reduction reaction rate constants are 2 orders of magnitude faster than all known heme/Cu complexes and these complexes retain >90% selectivity even under rate determining electron transfer conditions that generally can only be achieved by installing additional redox active groups in the catalyst.

Cardiometabolic disease and features of depression and bipolar disorder: population-based, cross-sectional study.

BACKGROUND: The relative contribution of demographic, lifestyle and medication factors to the association between affective disorders and cardiometabolic diseases is poorly understood. AIMS: To assess the relationship between cardiometabolic disease and features of depresion and bipolar disorder within a large population sample. METHOD: Cross-sectional study of 145 991 UK Biobank participants: multivariate analyses of associations between features of depression or bipolar disorder and five cardiometabolic outcomes, adjusting for confounding factors. RESULTS: There were significant associations between mood disorder features and 'any cardiovascular disease' (depression odds ratio (OR) = 1.15, 95% CI 1.12-1.19; bipolar OR = 1.28, 95% CI 1.14-1.43) and with hypertension (depression OR = 1.15, 95% CI 1.13-1.18; bipolar OR = 1.26, 95% CI 1.12-1.42). Individuals with features of mood disorder taking psychotropic medication were significantly more likely than controls not on psychotropics to report myocardial infarction (depression OR = 1.47, 95% CI 1.24-1.73; bipolar OR = 2.23, 95% CI 1.53-3.57) and stroke (depression OR = 2.46, 95% CI 2.10-2.80; bipolar OR = 2.31, 95% CI 1.39-3.85). CONCLUSIONS: Associations between features of depression or bipolar disorder and cardiovascular disease outcomes were statistically independent of demographic, lifestyle and medication confounders. Psychotropic medication may also be a risk factor for cardiometabolic disease in individuals without a clear history of mood disorder.

Electrochemical reduction of Brønsted acids by glassy carbon in acetonitrile-implications for electrocatalytic hydrogen evolution.

Molecular catalysts for electrochemically driven hydrogen evolution are often studied in acetonitrile with glassy carbon working electrodes and Brønsted acids. Surprisingly, little information is available regarding the potentials at which acids are directly reduced on glassy carbon. This work examines acid electroreduction in acetonitrile on glassy carbon electrodes by cyclic voltammetry. Reduction potentials, spanning a range exceeding 2 V, were found for 20 acids. The addition of 100 mM water was not found to shift the reduction potential of any acid studied, although current enhancement was observed for some acids. The data reported provides a guide for selecting acids to use in electrocatalysis experiments such that direct electrode reduction is avoided.

Impact of socioeconomic deprivation on rate and cause of death in severe mental illness.

BACKGROUND: Socioeconomic status has important associations with disease-specific mortality in the general population. Although individuals with Severe Mental Illnesses (SMI) experience significant premature mortality, the relationship between socioeconomic status and mortality in this group remains under investigated. We aimed to assess the impact of socioeconomic status on rate and cause of death in individuals with SMI (schizophrenia and bipolar disorder) relative to the local (Glasgow) and wider (Scottish) populations. METHODS: Cause and age of death during 2006-2010 inclusive for individuals with schizophrenia or bipolar disorder registered on the Glasgow Psychosis Clinical Information System (PsyCIS) were obtained by linkage to the Scottish General Register Office (GRO). Rate and cause of death by socioeconomic status, measured by Scottish Index of Multiple Deprivation (SIMD), were compared to the Glasgow and Scottish populations. RESULTS: Death rates were higher in people with SMI across all socioeconomic quintiles compared to the Glasgow and Scottish populations, and persisted when suicide was excluded. Differences were largest in the most deprived quintile (794.6 per 10,000 population vs. 274.7 and 252.4 for Glasgow and Scotland respectively). Cause of death varied by socioeconomic status. For those living in the most deprived quintile, higher drug-related deaths occurred in those with SMI compared to local Glasgow and wider Scottish population rates (12.3% vs. 5.9%, p = <0.001 and 5.1% p = 0.002 respectively). A lower proportion of deaths due to cancer in those with SMI living in the most deprived quintile were also observed, relative to the local Glasgow and wider Scottish populations (12.3% vs. 25.1% p = 0.013 and 26.3% p = <0.001). The proportion of suicides was significantly higher in those with SMI living in the more affluent quintiles relative to Glasgow and Scotland (54.6% vs. 5.8%, p = <0.001 and 5.5%, p = <0.001). CONCLUSIONS: Excess mortality in those with SMI occurred across all socioeconomic quintiles compared to the Glasgow and Scottish populations but was most marked in the most deprived quintiles when suicide was excluded as a cause of death. Further work assessing the impact of socioeconomic status on specific causes of premature mortality in SMI is needed.

Chronic multisite pain in major depression and bipolar disorder: cross-sectional study of 149,611 participants in UK Biobank.

BACKGROUND: Chronic pain has a strong association with major depressive disorder (MDD), but there is a relative paucity of studies on the association between chronic multisite pain and bipolar disorder (BD). Such studies are required to help elucidate the complex biological and psychological overlap between pain and mood disorders. The aim of this study is to investigate the relationship between chronic multisite pain and mood disorder across the unipolar-bipolar spectrum. METHODS: We conducted a cross-sectional study of 149,611 UK Biobank participants. Self-reported depressive and bipolar features were used to categorise participants into MDD and BD groups and a non-mood disordered comparison group. Multinomial logistic regression was used to establish whether there was an association between extent of chronic pain (independent variable) and mood disorder category (dependent variable), using no pain as the referent category, and adjusting for a wide range of potential sociodemographic, lifestyle and comorbidity confounders. RESULTS: Multisite pain was significantly more prevalent in participants with BD and MDD, for example, 4-7 pain sites: BD 5.8%, MDD 4.5%, and comparison group 1.8% (p < 0.001). A relationship was observed between extent of chronic pain and risk of BD and persisted after adjusting for confounders (relative to individuals with no chronic pain): 2-3 sites RRR of BD 1.84 (95% CI 1.61, 2.11); 4-7 sites RRR of BD 2.39 (95% CI 1.88, 3.03) and widespread pain RRR of BD 2.37 (95% CI 1.73, 3.23). A similar relationship was observed between chronic pain and MDD: 2-3 sites RRR of MDD 1.59 (95% CI 1.54, 1.65); 4-7 sites RRR of MDD 2.13 (95% CI 1.98, 2.30); widespread pain RRR of MDD 1.86 (95% CI 1.66, 2.08). CONCLUSIONS: Individuals who report chronic pain and multiple sites of pain are more likely to have MDD and are at higher risk of BD. These findings highlight an important aspect of comorbidity in MDD and BD and may have implications for understanding the shared neurobiology of chronic pain and mood disorders.

Combining scaling relationships overcomes rate versus overpotential trade-offs in O2 molecular electrocatalysis.

The development of advanced chemical-to-electrical energy conversions requires fast and efficient electrocatalysis of multielectron/multiproton reactions, such as the oxygen reduction reaction (ORR). Using molecular catalysts, correlations between the reaction rate and energy efficiency have recently been identified. Improved catalysis requires circumventing the rate versus overpotential trade-offs implied by such "scaling relationships." Described here is an ORR system-using a soluble iron porphyrin and weak acids-with the best reported combination of rate and efficiency for a soluble ORR catalyst. This advance is achieved not by "breaking" scaling relationships but rather by combining two of them. Key to this behavior is a polycationic ligand, which enhances anionic ligand binding and changes the catalyst E 1/2. These results show how combining scaling relationships is a powerful way toward improved electrocatalysis.

Spinal cord ischemia after TEVAR in patients with abdominal aortic aneurysms.

OBJECTIVE: To examine the incidence of and the anatomic factors that may contribute to spinal cord ischemia (SCI) in patients with a history of abdominal aortic aneurysms (AAA) after thoracic endovascular aortic repair (TEVAR). METHODS: The medical records, computed tomography (CT) angiograms, and a prospectively maintained clinical database of all TEVAR patients at a single institution between 2000 and 2007 were reviewed. Select preoperative demographics, thoracoabdominal aortoiliac anatomy, intraoperative procedural variables, and postoperative outcomes were examined. Univariate and multivariate analyses were performed and odds ratio estimates were reported with 95% confidence intervals. RESULTS: Of the 261 patients who underwent TEVAR, 27 developed SCI (10%). Thirteen (48%) of these 27 patients were completely reversed with spinal drainage, and 14 (52%) were permanent. Patients with SCI tended to be older (P = .006), male (P = .049), and required more emergent procedures (P = .051) performed under general anesthesia (P = .004). Interestingly, while prior AAA repair (50/261, 19%) alone was not associated with SCI (P = .44), a history of either repaired or unrepaired AAA (101/261, 39%) was a predictor of SCI on multivariate analysis (odds ratio [OR] = 4.35 [1.43, 14.3], P = .10), independent of thoracic aortic coverage (P = .001) and lumbar artery patency (P = .008), both of which were also associated with SCI. CONCLUSION: Although the causes of SCI after TEVAR are multifactorial, abdominal aortic anatomy appears to be associated with development of this complication. Patients with either prior AAA repair or those with unrepaired AAA appear to be at increased risk for SCI.

Outcomes After the Operative Treatment of Bucket-Handle Meniscal Tears in Children and Adolescents.

BACKGROUND: Bucket-handle meniscal tears (BHMTs), which we define as vertical longitudinal tears of the meniscus with displacement of the torn inner fragment toward the intercondylar notch region, are a well-recognized tear pattern. Optimizing the management of BHMTs in younger patients is important, as preserving meniscal tissue may limit future joint degeneration. PURPOSE/HYPOTHESIS: The purpose of this study was to review the patient demographics, clinical presentation, operative details, outcomes, and risk factors for a reoperation associated with operatively treated BHMTs in a pediatric population. We hypothesized that the repair of BHMTs in adolescents would yield a higher reoperation rate than meniscectomy in our population. STUDY DESIGN: Case-series; Level of evidence, 4. METHODS: A departmental database was queried to identify all patients 19 years or younger who presented with a BHMT and underwent surgery between October 2002 and February 2013. Clinical, radiological, and surgical data were retrospectively collected, and risk factors for a reoperation and persistent pain were assessed in all patients with longer than or equal to 6 months of follow-up. RESULTS: A total of 280 BHMTs were treated arthroscopically by 1 of 8 sports medicine fellowship-trained surgeons. The mean age at surgery was 15.5 ± 2.5 years (range, 2.1-19.2 years), and most patients were male (177/280; 63%). Most injuries occurred during sports (203/248; 82%) and involved the medial meniscus (157/280; 56%). Concurrent anterior cruciate ligament (ACL) surgery was performed in 103 cases (37%). Meniscal repair was performed in 181 cases (65%) and was more common in younger patients (P = .01) and for the lateral meniscus (P < .001). Among 185 (66%) cases with longer than or equal to 6 months of adequate follow-up data (which included 126 meniscal repairs [68%]), a meniscus-related reoperation occurred in 45 (24%) cases. A reoperation related to the original BHMT injury or surgery was more common after meniscal repair than after meniscectomy (40/126 [32%] vs 5/59 [8%], respectively) (P = .001) and less common with concurrent ACL surgery (P = .07), although this was not statistically significant. Among patients injured during sports and with adequate follow-up, all but 1 patient (176/177; 99%) returned to sports; a slower rate of return was seen in those undergoing meniscal repair (P = .002) and concurrent ACL surgery (P < .001). At final follow-up, 170 of 185 patients (92%) were pain free. For the 15 patients with persistent pain at final follow-up, no identifiable risk factors for persistent pain were identified. CONCLUSION: Most BHMTs in younger patients occurred in males and during sports and affected the medial meniscus. Concurrent ACL surgery was indicated in approximately one-third of cases and was associated with a lower reoperation rate and slower return to sports. Two-thirds of patients underwent meniscal repair, over two-thirds of whom did not require a reoperation during the study period, despite the high activity levels in this age group.

Epidemic pasteurellosis in a bighorn sheep population coinciding with the appearance of a domestic sheep.

A pneumonia epidemic reduced bighorn sheep (Ovis canadensis) survival and recruitment during 1997-2000 in a population comprised of three interconnected wintering herds (Kenosha Mountains, Sugarloaf Mountain, Twin Eagles) that inhabited the Kenosha and Tarryall Mountain ranges in central Colorado, USA. The onset of this epidemic coincided temporally and spatially with the appearance of a single domestic sheep (Ovis aires) on the Sugarloaf Mountain herd's winter range in December 1997. Although only bighorns in the Sugarloaf Mountain herd were affected in 1997-98, cases also occurred during 1998-99 in the other two wintering herds, likely after the epidemic spread via established seasonal movements of male bighorns. In all, we located 86 bighorn carcasses during 1997-2000. Three species of Pasteurella were isolated in various combinations from affected lung tissues from 20 bighorn carcasses where tissues were available and suitable for diagnostic evaluation; with one exception, beta-hemolytic mannheimia (Pasteurella) haemolytica (primarily reported as biogroup 1(G) or 1(alphaG)) was isolated from lung tissues of cases evaluated during winter 1997-98. The epidemic dramatically lowered adult bighorn monthly survival in all three herds; a model that included an acute epidemic effect, differing between sexes and with vaccination status, that diminished linearly over the next 12 mo best represented field data. In addition to the direct mortality associated with epidemics in these three herds, lamb recruitment in years following the pneumonia epidemic also was depressed as compared to years prior to the epidemic. Based on observations presented here, pasteurellosis epidemics in free-ranging bighorn sheep can arise through incursion of domestic sheep onto native ranges, and thus minimizing contact between domestic and bighorn sheep appears to be a logical principle for bighorn sheep conservation.

Qualitative extension of the EC' Zone Diagram to a molecular catalyst for a multi-electron, multi-substrate electrochemical reaction.

The EC' Zone Diagram, introduced by Savéant and Su over 30 years ago, has been used to classify voltammetric responses for electrocatalytic systems. With a single H2-evolving catalyst, Co(dmgBF2)2(CH3CH)2 (dmgBF2 = difluoroboryl-dimethylglyoxime), and a series of para-substituted anilinium acids, experimental conditions were carefully tuned to access to each region of the classic zone diagram. Close scrutiny revealed the extent to which the kinetic (λ) and excess (γ) factors could be experimentally controlled and used to access a variety of waveforms for this ECEC' catalytic system. It was found that most of the tunable experimental parameters (such as catalyst concentration, scan rate, and substrate concentration) predicted in the EC' Zone Diagram could be extended to a multi-electron system and produced similarly-shaped waveforms with some deviations. Tuning of a single catalyst across every region of the classic zone diagram has previously been prevented due to the seven orders of magnitude that need to be traversed across the kinetic parameter; however, the cobalt catalyst in this study provided unique control of this parameter. By varying the acids used as the proton source, the rate constants for protonation were tuned via a pKa-dependent linear free energy relationship.

Pediatric Dance Injuries: A Cross-Sectional Epidemiological Study.

OBJECTIVE: The purpose of this study was to analyze characteristics of dance injuries evaluated by sports medicine physicians. DESIGN: A cross-sectional epidemiological study of a 5% random probability sample of patients presenting for sports medicine evaluation between January 1, 2000, and December 31, 2009. SETTING: Sports medicine clinic of a tertiary-level pediatric medical center. PATIENTS: A total of 181 pediatric dancers (171 female and 10 male; 14.8 ± 2.0 years of age) with 222 injuries. MAIN OUTCOME MEASURES: Injury diagnoses, location, type, and treatment. RESULTS: Forty-six injury diagnoses were recorded in this random sample of pediatric dancers, with the most common being tendonitis/tendinopathy, patellofemoral pain syndrome, apophysitis, ankle impingement syndrome, and hip labral tear. Most of the injuries occurred in the lower extremities, with knee and ankle injuries being the most common. Injury classification by type revealed that joints were the body structure most likely to be injured, followed by soft tissues, skeletal elements, and growth plates. The most frequent joint injury was patellofemoral pain syndrome. The most frequent soft tissue injury was tendonitis/tendinopathy. The most common skeletal injury was a pars stress reaction/spondylolysis. The most common physeal injury was apophysitis. Dancers were treated mainly with physical therapy, surgery, or physical therapy, in addition to orthotics. CONCLUSION: Pediatric dancers experienced significant, and occasionally rare, injuries that may have long-term health consequences. Although injuries occurred mostly in the lower extremities and involved mainly joints, the most common specific diagnosis was tendonitis/tendinopathy. There is still much to learn about the management of dancers, and there is a need for further research into injury prevention, diagnosis, and treatment.

Trends in the Presentation, Management, and Outcomes of Little League Shoulder.

BACKGROUND: With rising participation in youth sports such as baseball, proximal humeral epiphysiolysis, or Little League shoulder (LLS), is being seen with increasing frequency. However, there remains a paucity of literature regarding the causes, natural history, or treatment outcomes of LLS. PURPOSE: To analyze the demographic, clinical, and diagnostic features of a population of LLS patients, with an emphasis on identifying underlying risk factors for the development and recurrence of LLS after nonoperative treatment. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: A departmental database at a high-volume regional children's hospital was queried to identify cases of LLS between 1999 and 2013. Medical records were reviewed to allow for analysis of age, sex, athletic information, physical examination and radiologic findings, treatment details, clinical course, and rates of recurrence. RESULTS: Ninety-five patients (93 males, 2 females; mean age, 13.1 years; range, 8-16 years) were diagnosed with LLS. The number of diagnosed cases increased annually over the study period. All patients had shoulder pain with overhead athletics; secondary symptoms included elbow pain in 13%, shoulder fatigue or weakness in 10%, and mechanical symptoms in 8%. While the majority of patients (97%) were baseball players (86% pitchers, 8% catchers, 7% other positions), a small subset (3%) were tennis players. On physical examination, 30% were reported to have glenohumeral internal rotation deficit (GIRD), defined as a decreased arc of rotational range of motion of the shoulder. Treatment recommendations included rest in 99% of cases, physical therapy in 79% (including 100% of patients with GIRD), and position change upon return to play in 26%. Average time to full resolution of symptoms was 2.6 months, while average time to return to competition was 4.2 months. Recurrent symptoms were reported in 7% of the overall cohort at a mean of 7.6 months after initial diagnosis. The odds of recurrence in the group with diagnosed GIRD (14%) were 3.6 times greater than those without GIRD (5%; 95% CI: 0.7-17.1), but this difference was not statistically significant (P = .11). CONCLUSION: Little League shoulder is being diagnosed with increasing frequency. While most common in male baseball pitchers, the condition can occur in females, youth catchers, other baseball positions players, and tennis players. Concomitant elbow pain may be seen in up to 13%. After rest and physical therapy, recurrent symptoms may occur in a small subset of patients (7%), generally 3 to 6 months after return to sports. Almost one-third of LLS patients had GIRD, and this group had approximately three times higher probability of recurrence compared with those without GIRD.