pH-Dependent Electrocatalytic Aqueous Ammonia Oxidation to Nitrite and Nitrate by a Copper(II) Complex with an Oxidation-Resistant Ligand.

The electrocatalytic aqueous ammonia oxidation (AO) represents a more sustainable alternative to accessing nitrite (NO) and nitrate (NO). We now report that Cu(pyalk) {pyalk = 2-(pyridin-2-yl)propan-2-oate}, previously employed as a homogeneous water oxidation (WO) catalyst, is also active for selective AO in aqueous environments. The traditional Griess analytical test for NO/NO was modified to permit the operation in the presence of the otherwise interfering Cu ion.

Modeling Electrochemical Vacancy Regeneration in Single-Walled Carbon Nanotubes.

Synthesis-induced defects in single-walled carbon nanotubes (SWCNTs) enable diverse catalytic reactions, but the nature of catalytic intermediates and how active species regeneration occurs are unclear. Using a quantum mechanics/molecular mechanics (QM/MM) hybrid methodology based on density functional theory (DFT) and a classical force-field, we explore the reactivity and electrochemical regeneration of a vacancy defect in a zigzag SWCNT. Our findings indicate that hydrolysis of the defect forms a ketone group on one carbon atom and C-H bonds on two adjacent carbons.

Ambulance service recognition of health inequalities and activities for reduction: An evidence and gap map of the published literature.

Background: Emergency medical services (EMS) are often patients' first point of contact for urgent and emergency care needs. Patients are triaged over the phone and may receive an ambulance response, with potential conveyance to the hospital. A recent scoping review suggested disparities in EMS patient care in the United States.

BODIPY Chemisorbed on SnO and TiO Surfaces for Photoelectrochemical Applications.

Advancement toward dye-sensitized photoelectrochemical cells to produce solar fuels by solar-driven water splitting requires a photosensitizer that is firmly attached to the semiconducting photoelectrodes. Covalent binding enhances the efficiency of electron injection from the photoexcited dye into the metal oxide. Optimization of charge transfer, efficient electron injection, and minimal electron-hole recombination are mandatory for achieving high efficiencies.

Feed-Forward Neural Network for Predicting Enantioselectivity of the Asymmetric Negishi Reaction.

Density functional theory (DFT) is a powerful tool to model transition state (TS) energies to predict selectivity in chemical synthesis. However, a successful multistep synthesis campaign must navigate energetically narrow differences in pathways that create some limits to rapid and unambiguous application of DFT to these problems. While powerful data science techniques may provide a complementary approach to overcome this problem, doing so with the relatively small data sets that are widespread in organic synthesis presents a significant challenge.

Manipulation Under Anesthesia and/or Lysis of Adhesions After Anterior Cruciate Ligament Reconstruction in Female Basketball Players: Does Race Play a Role?

Background: Arthrofibrosis can limit function and return to sport after anterior cruciate ligament (ACL) reconstruction. Previously reported risk factors for developing arthrofibrosis after ACL reconstruction include female sex, age <18 years, time from injury to surgery <28 days, concomitant meniscal repair, prolonged immobilization, and genetic factors. There is a lack of evidence regarding whether race plays a significant role.

Medialized Rip-Stop Convergence Technique for Retracted Rotator Cuff Tears.

Attempts to restore the anatomical footprint during rotator cuff repair for retracted, relatively immobile tears can be difficult. In some cases, it can lead to excessive tension of the repair. Previous studies have noted improved clinical outcomes when repair tension is not excessive, and medialization of the anatomical footprint has been suggested as a technique that can help surgeons repair large, retracted tears without excessive tension and achieve improved clinical outcomes.

-Allylhydroxyamine: A Bifunctional Olefin for Construction of Axially and Centrally Chiral Amino Alcohols via Asymmetric Carboamidation.

Difunctionalization of olefins offers an attractive approach to access complex chiral structures. Reported herein is the design of -protected -allylhydroxyamines as bifunctional olefins that undergo catalytic asymmetric 1,2-carboamidation with three classes of (hetero)arenes to afford chiral amino alcohols via C-H activation. The C═C bond in -allylhydroxyamine is activated by the intramolecular electrophilic amidating moiety as well as a migrating directing group.

Sigma-Bond Metathesis as an Unusual Asymmetric Induction Step in Rhodium-Catalyzed Enantiodivergent Synthesis of C-N Axially Chiral Biaryls.

Mechanistic understanding of asymmetric induction plays a crucial role in designing new catalytic asymmetric reactions. Reported herein is atroposelective access to C-N axially chiral isoquinolones via rhodium-catalyzed C-H activation of -alkoxy benzamides and annulation with imidoyl sulfoxonium ylides. The coupling system proceeded with excellent functional group tolerance, and different conditions were identified to afford one or the other enantiomeric product each in excellent enantioselectivity for a representative class of the sulfoxonium ylide reagent, thus making both enantiomers readily available using the same catalyst.

Bicondylar tibial plateau fracture dislocations with an intact anterolateral cortical rim: A surgical technique.

A displaced medial tibial plateau fracture with central and lateral impaction, but an intact anterolateral cortical rim, is an uncommon variant of bicondylar tibial plateau fracture that presents a number of challenges. Without a lateral metaphyseal fracture line to work through, it is challenging to address central and lateral impaction. Previously published techniques for addressing this fracture pattern describe an intra-articular osteotomy of the lateral plateau to aid visualization and reduction, or use a posterolateral approach to the proximal tibia with or without an osteotomy of the proximal fibula.

BODIPY and dipyrrin as unexpected robust anchoring groups on TiO nanoparticles.

Covalent attachment of molecules to metal oxide surfaces typically demands the presence of an anchoring group that in turn requires synthetic steps to introduce. BODIPY (4,4-difluoro-4-bora-3a,4a-diaza--indacene) chromophores have long been used in dye-sensitized solar cells, but carboxylic acid groups typically had to be installed to act as surface anchors. We now find that even without the introduction of such anchors, the unmodified BODIPY can bind to TiO surfaces its BF group through boron-oxygen surface bonds.

Optimization of Surface Loading of the Silatrane Anchoring Group on TiO.

Anchoring groups are usually needed for the attachment of small molecules to metal oxide surfaces such as in water-splitting dye-sensitized photoelectrochemical cells (WS-DSPECs). Here, we optimize the surface loading onto titanium dioxide surfaces of the silatrane anchoring group, a triethanolamine-protected trialkoxysilane. This anchoring group is not yet widely used because prior protocols afforded low surface coverage, but it has the advantage of high stability over a wide pH range and at both oxidizing and reducing potentials when bound.

Distorted Copper(II) Complex with Unusually Short CF···Cu Distances.

We find a Cu(II)-() complex ( = 2,2,2-trifluoro--[2-(pyridin-2-yl)propan-2-yl]acetamide) with a distorted "seesaw" geometry. It has the shortest crystallographic CF···Cu distances yet reported, to the best of our knowledge (<2.6 Å), for which computational and experimental data indicate a secondary bonding interaction.

Electronic and Spin-State Effects on Dinitrogen Splitting to Nitrides in a Rhenium Pincer System.

Bimetallic nitrogen (N) splitting to form metal nitrides is an attractive method for N fixation. Although a growing number of pincer-supported systems can bind and split N, the precise relationship between the ligand properties and N binding/splitting remains elusive. Here we report the first example of an N-bridged rhenium(III) complex, [(-PPyrr)ReCl](μ-η:η-N) (PPyrr = [2,5-(CHPBu)CHN]).

Surprisingly big linker-dependence of activity and selectivity in CO reduction by an iridium(i) pincer complex.

Here, we report the quantitative electroreduction of CO2 to CO by a PNP-pincer iridium(i) complex bearing amino linkers in DMF/water. The electrocatalytic properties greatly depend on the choice of linker within the ligand. The complex 3-N is far superior to the analogues with methylene and oxygen linkers, showing higher activity and better selectivity for CO2 over proton reduction.

Concerted proton-electron transfer oxidation of phenols and hydrocarbons by a high-valent nickel complex.

The high-valent nickel(iii) complex Ni(pyalk) () was prepared by oxidation of a nickel(ii) complex, Ni(pyalk) () (pyalk = 2-pyridyl-2-propanoate). and derivatives were fully characterized by mass spectrometry and X-ray crystallography. Electron paramagnetic resonance spectroscopy and X-ray photoelectron spectroscopy confirm that the oxidation is metal-centered.

Trends and Risk Factors in Orthopedic Lawsuits: Analysis of a National Legal Database.

Orthopedic surgeons frequently encounter medical malpractice claims. The purpose of this study was to assess trends and risk factors in lawsuits brought against orthopedic surgeons using a national legal database. A legal research service was used to search publicly available settlement and verdict reports between 1988 and 2013 by terms "orthopaedic or orthopedic" and "malpractice.

On the damage done to the structure of the Thermoplasma acidophilum proteasome by electron radiation.

It has long been known that proteins are damaged when they are exposed to the electron beam in an electron microscope. Here we show that exposure to electrons under cryo-EM conditions leads to a small change in the quaternary structure of the Thermoplasma acidophilum proteasome, and that backbones atoms belonging to the α-helices in this molecule appear to be particular prone to chemical damage. A chemical mechanism is proposed for this damage.

Silatrane Anchors for Metal Oxide Surfaces: Optimization for Potential Photocatalytic and Electrocatalytic Applications.

Silatrane surface anchors are protected siloxanes that are known to bond firmly (from pH 2-11) to metal oxide electrodes under heating. However, these conditions are not always compatible with the other functionality present. A silatrane-containing porphyrin molecule and a silatrane-containing ruthenium complex have now been designed, synthesized and optimized conditions have been identified for surface binding.