Surgical Management of Iatrogenic Mercury Poisoning From Subcutaneous Injection Into the Arm.

BACKGROUND: Mercury, an element with threats of severe toxic insult to humans and no biological function, has a surprisingly extensive record of human exposure. Regardless of hesitancies toward its harmfulness, it has been historically identified with an almost supernatural power to provide protection from evil and sickness, give good fortune, lend aid in athletic undertakings, or even allow one to achieve immortality. Mercury poisoning is an iatrogenic disease even today as people attempt to achieve these effects through volitional injections into their body by practitioners. Although an uncommon practice in the United States, awareness of patient presentation after volitional injections of elemental mercury is necessary for appropriate treatment of these patients. We aim to increase awareness of the cultural practice of subcutaneous injections of mercury, as it is uncommonly seen in the United States, to contribute a broader understanding to the patient's medical presentation and describe an approach and the impact of medical and surgical intervention. METHODS: In this report, we describe a rare case of elemental mercury poisoning secondary to volitional subcutaneous injection to the arm. Initial management of care through chelation therapy and monitoring of renal and serum mercury levels in addition to symptoms of systemic spread was overseen by an internal medicine physician and poison control. Surgical intervention via full-thickness excision of the visible mercury to the right arm followed by local flap and skin grafting reconstruction was performed. CONCLUSIONS: Mercury poisoning from intentional subcutaneous administration is an uncommon patient presentation in the United States; however, knowledge of management of this rare condition is important for effective management of iatrogenic mercury toxicity.

Scope of practice of oculofacial plastic and reconstructive surgeons: a public perception survey.

PURPOSE: The purpose of this study is to determine the public's perception of the scope of practice for oculofacial plastic and reconstructive surgeons (OFPRS). METHODS: A 49-question survey was distributed by QualtricsⓇ to a panel similar to the US demographic composition. Responses collected underwent bivariate statistical analysis. RESULT: A total of 530 responses were obtained, with most respondents being white, female, over the age of 35, from the Midwest, and with at least a college education or above. Most respondents did not think ophthalmologists or optometrists were surgeons, and only 158 people (29.8%) knew the primary specialty of OFPRS was ophthalmology. Board certification was preferred by 98.87% of respondents, and 95.28% preferred ASOPRS-trained OFPRS. CONCLUSIONS: Our study highlights the gap in knowledge about OFPRS as a field, the qualifications and training required, and the scope of practice. Notably, even for OFPRS-specific procedures, PRS remained the leading subspecialist chosen for interventions such as orbital decompression (58.5% vs. 71.5%), orbital reconstruction (57.9% vs. 74.2%), enucleation/evisceration (48.1% vs. 53.4%), optic nerve-related surgery (39.8% vs. 43.4%), orbital cancer resection (42.8% vs. 46.8%), and tear duct surgery (41.9% vs. 52.5%). Additionally, most respondents did not feel that facial fillers, laser skin resurfacing, eyelid cancer removal, or cataract surgery were within the OFPRS scope of practice.

Interfacial Chemistry Effects in the Electrochemical Performance of Silicon Electrodes under Lithium-Ion Battery Conditions.

Understanding the solid electrolyte interphase (SEI) formation and (de)lithiation phenomena at silicon (Si) electrodes is key to improving the performance and lifetime of Si-based lithium-ion batteries. However, these processes remain somewhat elusive, and, in particular, the role of Si surface termination merits further consideration. Here, scanning electrochemical cell microscopy (SECCM) is used in a glovebox, followed by secondary ion mass spectrometry (SIMS) at identical locations to study the local electrochemical behavior and associated SEI formation, comparing Si (100) with a native oxide layer (SiOx /Si) and etched with hydrofluoric acid (HF-Si). HF-Si shows greater spatial electrochemical heterogeneity and inferior lithiation reversibility than SiOx /Si. This is attributed to a weakly passivating SEI and irreversible lithium trapping at the Si surface. Combinatorial screening of charge/discharge cycling by SECCM with co-located SIMS reveals SEI chemistry as a function of depth. While the SEI thickness is relatively independent of the cycle number, the chemistry - particularly in the intermediate layers - depends on the number of cycles, revealing the SEI to be dynamic during cycling. This work serves as a foundation for the use of correlative SECCM/SIMS as a powerful approach to gain fundamental insights on complex battery processes at the nano- and microscales.

Designing mixed-metal electrocatalyst systems for photoelectrochemical dinitrogen activation.

Efficient artificial photosynthesis systems are currently realized as catalyst- and surface-functionalized photovoltaic tandem-and triple-junction devices, enabling photoelectrochemical (PEC) water oxidation while simultaneously recycling CO2 and generating hydrogen as a solar fuel for storable renewable energy. Although PEC systems also bear advantages for the activation of dinitrogen - such as a high system tunability with respect to the electrocatalyst integration and a directly controllable electron flux to the anchoring catalyst through the adjustability of incoming irradiation - only a few PEC devices have been developed and investigated for this purpose. We have developed a series of photoelectrodeposition procedures to deposit mixed-metal electrocatalyst nanostructures directly on the semiconductor surface for light-assisted dinitrogen activation. These electrocatalyst compositions containing Co, Mo and Ru in different atomic ratios follow previously made recommendations of metal compositions for dinitrogen reduction and exhibit different physical properties. XPS studies of the photoelectrode surfaces reveal that our electrocatalyst films are to a large degree nitrogen-free after their fabrication, which is generally difficult to achieve with traditional magnetron sputtering or e-beam evaporation techniques. Initial chronoamperometric measurements of the p-InP photoelectrode coated with the Co-Mo alloy electrocatalyst show higher photocurrent densities in the presence of N2(g) than in the presence of Ar at -0.09 V vs. RHE. Indications of successful dinitrogen activation have also been found in consecutive XPS studies, where both N 1s and Mo 3d spectra reveal evidence of nitrogen-metal interactions.

The Influence of Defects on the Luminescence of Trivalent Terbium in Nanocrystalline Yttrium Orthovanadate.

Terbium-doped YVO4 has been considered a nonluminescent solid since the first classic studies on rare-earth-doped phosphors in the 1960s. However, we demonstrate that defect engineering of YVO4:Tb3+ nanoparticles overcomes the metal-metal charge transfer (MMCT) process which is responsible for the quenching of the Tb3+ luminescence. Tetragonal (Y1-xTbx)VO4 nanoparticles obtained by colloidal precipitation showed expanded unit cells, high defect densities, and intimately mixed carbonates and hydroxides, which contribute to a shift of the MMCT states to higher energies. Consequently, we demonstrate unambiguously for the first time that Tb3+ luminescence can be excited by VO43- → Tb3+ energy transfer and by direct population of the 5D4 state in YVO4. We also discuss how thermal treatment removes these effects and shifts the quenching MMCT state to lower energies, thus highlighting the major consequences of defect density and microstructure in nanosized phosphors. Therefore, our findings ultimately show nanostructured YVO4:Tb3+ can be reclassified as a UV-excitable luminescent material.

From graphene to graphene oxide: the importance of extended topological defects.

Graphene oxide (GO) represents a complex family of materials related to graphene: easy to produce in large quantities, easy to process, and convenient to use as a basis for further functionalization, with the potential for wide-ranging applications such as in nanocomposites, electronic inks, biosensors and more. Despite their importance, the key structural traits of GO, and the impact of these traits on properties, are still poorly understood due to the inherently berthollide character of GO which complicates the establishment of clear structure/property relationships. Widely accepted structural models of GO frequently neglect the presence of extended topological defects, structural changes to the graphene basal plane that are not removed by reduction methods. Here, a combination of experimental approaches and molecular simulations demonstrate that extended topological defects are a common feature across GO and that the presence of these defects strongly influences the properties of GO. We show that these extended topological defects are produced following even controlled 'gentle' functionalization by atomic oxygen and are comparable to those obtained by a conventional modified Hummers' method. The presence of the extended topological defects is shown to play an important role in the retention of oxygen functional groups after reduction. As an exemplar of their effect on the physical properties, we show that the GO sheets display a dramatic decrease in strength and stiffness relative to graphene and, due to the presence of extended structural defects, no improvement is seen in the mechanical properties after reduction. These findings indicate the importance of extended topological defects to the structure and properties of functionalized graphene, which merits their inclusion as a key trait in simple structural models of GO.

Protecting Group Free Synthesis of Glyconanoparticles Using Amino-Oxy-Terminated Polymer Ligands.

Glycomaterials display enhanced binding affinity to carbohydrate-binding proteins due to the nonlinear enhancement associated with the cluster glycoside effect. Gold nanoparticles bearing glycans have attracted significant interest in particular. This is due to their versatility, their highly tunable gold cores (size and shape), and their application in biosensors and diagnostic tools. However, conjugating glycans onto these materials can be challenging, necessitating either multiple protecting group manipulations or the use of only simple glycans. This results in limited structural diversity compared to glycoarrays which can include hundreds of glycans. Here we report a method to generate glyconanoparticles from unprotected glycans by conjugation to polymer tethers bearing terminal amino-oxy groups, which are then immobilized onto gold nanoparticles. Using an isotope-labeled glycan, the efficiency of this reaction was probed in detail to confirm conjugation, with 25% of end-groups being functionalized, predominantly in the ring-closed form. Facile post-glycosylation purification is achieved by simple centrifugation/washing cycles to remove excess glycan and polymer. This streamlined synthetic approach may be particularly useful for the preparation of glyconanoparticle libraries using automation, to identify hits to be taken forward using more conventional synthetic methods. Exemplar lectin-binding studies were undertaken to confirm the availability of the glycans for binding and show this is a powerful tool for rapid assessment of multivalent glycan binding.

Polymer-Stabilized Sialylated Nanoparticles: Synthesis, Optimization, and Differential Binding to Influenza Hemagglutinins.

During influenza infection, hemagglutinins (HAs) on the viral surface bind to sialic acids on the host cell's surface. While all HAs bind sialic acids, human influenza targets terminal α2,6 sialic acids and avian influenza targets α2,3 sialic acids. For interspecies transmission (zoonosis), HA must mutate to adapt to these differences. Here, multivalent gold nanoparticles bearing either α2,6- or α2,3-sialyllactosamine have been developed to interrogate a panel of HAs from pathogenic human, low pathogenic avian, and other species' influenza. This method exploits the benefits of multivalent glycan presentation compared to monovalent presentation to increase affinity and investigate how multivalency affects selectivity. Using a library-orientated approach, parameters including polymer coating and core diameter were optimized for maximal binding and specificity were probed using galactosylated particles and a panel of biophysical techniques [ultraviolet-visible spectroscopy, dynamic light scattering, and biolayer interferometry]. The optimized particles were then functionalized with sialyllactosamine and their binding analyzed against a panel of HAs derived from pathogenic influenza strains including low pathogenic avian strains. This showed significant specificity crossover, which is not observed in monovalent formats, with binding of avian HAs to human sialic acids and vice versa in agreement with alternate assay formats. These results demonstrate that precise multivalent presentation is essential to dissect the interactions of HAs and may aid the discovery of tools for disease and zoonosis transmission.

Versailles Project on Advanced Materials and Standards interlaboratory study on intensity calibration for x-ray photoelectron spectroscopy instruments using low-density polyethylene.

We report the results of a Versailles Project on Advanced Materials and Standards interlaboratory study on the intensity scale calibration of x-ray photoelectron spectrometers using low-density polyethylene (LDPE) as an alternative material to gold, silver, and copper. An improved set of LDPE reference spectra, corrected for different instrument geometries using a quartz-monochromated Al Kα x-ray source, was developed using data provided by participants in this study. Using these new reference spectra, a transmission function was calculated for each dataset that participants provided. When compared to a similar calibration procedure using the NPL reference spectra for gold, the LDPE intensity calibration method achieves an absolute offset of ∼3.0% and a systematic deviation of ±6.5% on average across all participants. For spectra recorded at high pass energies (≥90 eV), values of absolute offset and systematic deviation are ∼5.8% and ±5.7%, respectively, whereas for spectra collected at lower pass energies (<90 eV), values of absolute offset and systematic deviation are ∼4.9% and ±8.8%, respectively; low pass energy spectra perform worse than the global average, in terms of systematic deviations, due to diminished count rates and signal-to-noise ratio. Differences in absolute offset are attributed to the surface roughness of the LDPE induced by sample preparation. We further assess the usability of LDPE as a secondary reference material and comment on its performance in the presence of issues such as variable dark noise, x-ray warm up times, inaccuracy at low count rates, and underlying spectrometer problems. In response to participant feedback and the results of the study, we provide an updated LDPE intensity calibration protocol to address the issues highlighted in the interlaboratory study. We also comment on the lack of implementation of a consistent and traceable intensity calibration method across the community of x-ray photoelectron spectroscopy (XPS) users and, therefore, propose a route to achieving this with the assistance of instrument manufacturers, metrology laboratories, and experts leading to an international standard for XPS intensity scale calibration.

The Effect of Autologous Fat Grafting on Edema and Ecchymoses in Primary Open Rhinoplasty.

BACKGROUND: Autologous fat is a safe and effective soft tissue filler. Recent evidence also suggests improved wound healing and immune modulation with fat grafting. OBJECTIVES: The aim of this study was to describe a novel technique utilizing fat grafting during primary open rhinoplasty. We hypothesize a more rapid resolution of bruising and edema. METHODS: Patients who underwent rhinoplasty were reviewed and compared by presence or absence of concurrent fat grafting. Three-dimensional images were analyzed employing Mirror (Vectra, Canfield Scientific, NJ). Ecchymoses were outlined utilizing a magnetic lasso followed by an area measurement. Volumetric edema measurements were also taken and assessed. Edema and ecchymosis were measured at 2 and 6 weeks postoperatively. Statistical significance was defined as P < 0.05. RESULTS: Sixty-two patients were included. Thirty-three patients (53.2%) received autologous fat grafting and 29 (46.8%) did not. Age, gender, surgical approach, and osteotomy distribution were similar between the groups. The fat grafted group showed 7.29 cm2 fewer ecchymoses (P < 0.001) and 0.73 cc less edema (P = 0.68) in the early postoperative interval. Six weeks postoperatively, the fat grafted group showed 1 cc less edema (P = 0.36) with negligible differences in bruising. CONCLUSIONS: Autologous fat grafting is a useful adjunct to rhinoplasty and is associated with significantly fewer ecchymoses in the acute postoperative period.

Multivalent Presentation of Ice Recrystallization Inhibiting Polymers on Nanoparticles Retains Activity.

Poly(vinyl alcohol) (PVA) has emerged as the most potent mimic of antifreeze (glyco)proteins ice recrystallization inhibition (IRI) activity, despite its lack of structural similarities and flexible, rather than rigid, backbone. The precise spacing of hydroxyl groups is hypothesized to enable PVA to recognize the prism planes of ice but not the basal plane, due to hydroxyl pattern matching of the ice surface giving rise to the macroscopic activity. Here, well-defined PVA derived from reversible addition-fragmentation chain-transfer (RAFT) polymerization is immobilized onto gold nanoparticles to enable the impact of nanoscale assembly and confinement on the observed IRI activity. Unlike previous reports using star-branched or bottle-brush PVAs, the nanoparticle-PVA retains all IRI activity compared to polymers in solution. Evidence is presented to show that this is due to the low grafting densities on the particle surface meaning the chains are free to explore the ice faces, rather than being constrained as in star-branched polymers. These results demonstrate a route to develop more functional IRI's and inclusion of metallic particle cores for imaging and associated applications in cryobiology.

Work function of GaAs(hkl) and its modification using PEI: mechanisms and substrate dependence.

Spin-coating of poly(ethylenimine) (PEI) has been used to reduce the work function of GaAs (001), (110), (111)A and (111)B. The magnitude of the reduction immediately after coating varies significantly from 0.51 eV to 0.69 eV and depends on the surface crystal face, on the GaAs bulk doping and on the atomic termination of the GaAs. For all samples, the work function reduction shrinks in ambient air over the first 20 hours after spin coating, but reductions around 0.2-0.3 eV persist after 1 year of storage in air. Core-level photoemission of thin film PEI degradation in air is consistent with a two-stage reaction with CO2 and H2O previously proposed in carbon capture studies. The total surface dipole from PEI coating is consistent with a combination of internal neutral amine dipole and an interface dipole whose magnitude depends on the surface termination. The contact potential difference measured by Kelvin probe force microscopy on a cleaved GaAs heterostructure is smaller on p-doped regions. This can be explained by surface doping due to the PEI, which increases the band bending on p-doped GaAs where Fermi level pinning is weak. Both surface doping and surface dipole should be accounted for when considering the effect of PEI coated on a semiconductor surface.

Three-dimensional Analysis of How Radiation Affects Deep Inferior Epigastric Perforator (DIEP) Flap Volume, Projection, and Position in Breast Cancer Reconstruction.

BACKGROUND: The deep inferior epigastric perforator (DIEP) flap has gained popularity for autologous free flap breast reconstruction. Historically, patients receiving post mastectomy radiation therapy (PMRT) were not candidates for immediate autologous reconstruction due to concerns for flap volume depletion, fat necrosis, and flap failure. However, this literature is anecdotal and lacks case controls. We objectively analyzed the effects radiation imparts on immediate DIEP flap reconstruction using 3-dimensional software and inherent controls. METHODS: We performed a cohort study on breast cancer patients who underwent immediate bilateral DIEP flap reconstructions followed by PMRT between 2005 and 2014. Exclusion criteria included patients less than 6 months from PMRT completion and bilateral PMRT. Three-dimensional photographs were analyzed using Geomagic (Rock Hill, SC) software to compare flap position, projection, and volume between the irradiated and nonirradiated reconstructed breasts. Breast Q survey evaluated patients' satisfaction. RESULTS: Eleven patients met inclusion criteria. Average time from PMRT completion to photo acquisition was 1.93 years. There was no statistical difference in average volume or projection in the irradiated versus nonirradiated side (P = 0.087 and P = 0.176, respectively). However, position of the irradiated flaps was significantly higher on the chest wall compared to controls (mean difference, 1.325 cm; P < 0.004). CONCLUSIONS: Three-dimensional analysis exhibited no statistical differences in projection or volume between irradiated DIEP flaps and nonirradiated controls. However, irradiated DIEP flaps were positioned higher on the chest wall, similar to observations in irradiated tissue expanders/implants. Patients were satisfied as measured by Breast Q. Immediate bilateral DIEP flap reconstructions can safely be performed with PMRT with satisfactory results.

Impact of sequential surface-modification of graphene oxide on ice nucleation.

Base-washed graphene-oxide which has been sequentially-modified by thiol-epoxy chemistry, results in materials with ice-nucleation activity. The role of hydro-philic/phobic grafts and polymers was evaluated with the most potent functioning at just 0.25 wt%. These 2-D hybrid materials may find use in cryopreservation and fundamental studies on ice formation.

Low-Voltage Voltammetric Electrowetting of Graphite Surfaces by Ion Intercalation/Deintercalation.

We demonstrate low-voltage electrowetting at the surface of freshly cleaved highly oriented pyrolytic graphite (HOPG). Using cyclic voltammetry (CV), electrowetting of a droplet of a sodium perchlorate solution is observed at moderately positive potentials on high-quality (low step edge coverage) HOPG, leading to significant changes in the contact angle and relative contact diameter that are comparable to the results of the widely studied electrowetting on dielectric (EWOD) system, but over a much lower voltage range. The electrowetting behavior is found to be reasonably fast, reversible, and repeatable for at least 20 cyclic scans (maximum tested). In contrast to classical electrowetting, e.g., EWOD, the electrowetting of the droplet on HOPG occurs with the intercalation/deintercalation of anions between the graphene layers of graphite, driven by the applied potential, observed in the CV response, and detected by X-ray photoelectron spectroscopy. The electrowetting behavior is strongly influenced by those factors that affect the extent of the intercalation/deintercalation of ions on graphite, such as potential range scan rate, potential polarity, quality of the HOPG substrate (step edge density and step height), and type of anion in the solution. In addition to perchlorate, sulfate salts also promote electrowetting, but some other salts do not. Our findings suggest a new mechanism for electrowetting based on ion intercalation, and the results are important to fundamental electrochemistry as well as to diversifying the means by which electrowetting can be controlled and applied.

"Grafting to" of RAFTed Responsive Polymers to Glass Substrates by Thiol-Ene and Critical Comparison to Thiol-Gold Coupling.

Surface-grafted polymers have been widely applied to modulate biological interfaces and introduce additional functionality. Polymers derived from reversible addition-fragmentation transfer (RAFT) polymerization have a masked thiol at the ω-chain end providing an anchor point for conjugation and in particular displays high affinity for gold surfaces (both flat and particulate). In this work, we report the direct grafting of RAFTed polymers by a "thiol-ene click" (Michael addition) onto glass substrates rather than gold, which provides a more versatile surface for subsequent array-based applications but retains the simplicity. The immobilization of two thermoresponsive polymers are studied here, poly[oligo(ethylene glycol) methyl ether methacrylate] (pOEGMA) and poly(N-isopropylacrylamide) (pNIPAM). Using a range of surface analysis techniques the grafting efficiency was compared to thiol-gold and was quantitatively compared to the gold alternative using quartz crystal microbalance. It is shown that this method gives easy access to grafted polymer surfaces with pNIPAM resulting in significantly increased surface coverage compared to pOEGMA. The nonfouling (protein resistance) character of these surfaces is also demonstrated.

A silver-free, reflective substrate electrode for electron extraction in top-illuminated organic photovoltaics.

The choice of metals suitable as the reflective substrate electrode for top-illuminated organic photovoltaics (OPVs) is extremely limited. Herein, we report a novel substrate electrode for this class of OPV architecture based on an Al | Cu | AlOx triple-layer structure, which offers a reflectivity comparable to that of Al over the wavelength range 400-900 nm, a work function suitable for efficient electron extraction in OPVs and high stability towards oxidation. In addition to demonstrating the advantage of this composite electrode over Al in model top-illuminated OPVs, we also present the results of a photoelectron spectroscopy study, which show that an oxidised 0.8 nm Al layer deposited by thermal evaporation onto an Al | Cu reflective substrate electrode is sufficient to block oxidation of the underlying Cu by air or during deposition of a ZnO1-x electron-transport layer. This is remarkable given that the self-limiting oxide thickness on Al metal is greater than 2 nm.

Sonographic evaluation of hydronephrosis in the pediatric population: is well-tempered sonography necessary?

OBJECTIVES: Standardized protocols exist for diuretic renography. There are no specific guidelines regarding hydration before renal sonography. This study assessed the importance of the hydration status by sonographic measurements of the anteroposterior diameter and its effect on Society for Fetal Urology (SFU) hydronephrosis grading. METHODS: Children aged 6 weeks to 16 years (mean age, 22 months) with unilateral SFU grade 3 or 4 hydronephrosis requiring diuretic renal scintigraphy were recruited to undergo prehydration and posthydration renal sonography. Hydrated diuretic renal scintigraphy, or "well-tempered" renography, was then performed. Renal sonograms were reviewed by a blinded pediatric radiologist and pediatric urologist. Two-sided statistical tests assessed whether SFU grades and the anteroposterior diameter changed significantly after hydration. RESULTS: Among 67 kidneys, the pediatric urologist (L.P.M.) and pediatric radiologist (V.J.R.) reported no SFU grade change in 45 (67%) and 52 (78%) kidneys after hydration. In kidneys that changed, the posthydration grade was more likely to be higher. This difference was statistically significant (14 of 22 and 13 of 15 differences were higher grades after hydration for L.P.M. and V.J.R., respectively; P= .06; P= .007). Most kidneys that changed with hydration differed by only 1 SFU grade. Differences greater than 1 grade were seen in 5 control kidneys, which increased from SFU grade 0 to 2. The mean anteroposterior diameter increased significantly between prehydration and posthydration sonography for both hydronephrotic kidneys (1.46 versus 1.72 cm; P< .001) and control kidneys (0.22 versus 0.39 cm; P= .019), but did not correlate with increased SFU grades. CONCLUSIONS: Hydration does have a substantial effect on the anteroposterior diameter, but it does not correlate with a substantial effect on the SFU grade; therefore, well-tempered sonography seems unnecessary.