Electrochemical oxygen reduction to hydrogen peroxide at practical rates in strong acidic media.

Electrochemical oxygen reduction to hydrogen peroxide (H2O2) in acidic media, especially in proton exchange membrane (PEM) electrode assembly reactors, suffers from low selectivity and the lack of low-cost catalysts. Here we present a cation-regulated interfacial engineering approach to promote the H2O2 selectivity (over 80%) under industrial-relevant generation rates (over 400 mA cm-2) in strong acidic media using just carbon black catalyst and a small number of alkali metal cations, representing a 25-fold improvement compared to that without cation additives. Our density functional theory simulation suggests a "shielding effect" of alkali metal cations which squeeze away the catalyst/electrolyte interfacial protons and thus prevent further reduction of generated H2O2 to water. A double-PEM solid electrolyte reactor was further developed to realize a continuous, selective (∼90%) and stable (over 500 hours) generation of H2O2 via implementing this cation effect for practical applications.

Does the Magnitude of the Electrocardiogram QT Interval Dispersion Predict Stroke Outcome?

BACKGROUND: QT dispersion, maximal interlead difference in QT interval on 12-lead electrocardiogram (ECG), measures cardiac repolarization abnormalities. Data are conflicting whether QT dispersion predicts adverse outcome in acute ischemic stroke (AIS) patients. Our objective is to determine if QT dispersion predicts: (1) short-term clinical outcome in AIS, and (2) stroke location (insular versus noninsular cortex). METHODS: Admission ECGs from 412 consecutive patients with acute stroke symptoms from 2 university-based stroke centers were reviewed. QT dispersion was measured. A neuroradiologist reviewed brain imaging for insular cortex involvement. Favorable clinical outcomes at discharge were modified Rankin Scale (mRS) score of 0-1, discharge National Institutes of Health Stroke Scale (NIHSS) score less than 2, and discharge to home. Multiple logistic regressions were performed for each outcome measure and to determine the association between insular infarct and QT dispersion. RESULTS: Of 145 subjects in the final analysis, median age was 65 years (interquartile range [IQR] 56-75), male patients were 38%, black patients were 68%, median QT dispersion was 78 milliseconds (IQR 59-98), and median admission NIHSS score was 4 (IQR 2-6). QT dispersion did not predict short-term clinical outcome for mRS score (odds ratio [OR] = 1.001, 95% confidence interval [CI] .99-1.01, P = .85), NIHSS at discharge (OR = .994, 95% CI .98-1.01, P = .30), or discharge disposition (OR = 1.001, 95% CI .99-1.01, P = .81). Insular cortex involvement did not correlate with QT dispersion magnitude (OR = 1.009, 95% CI .99-1.02, P = .45). CONCLUSIONS: We could not demonstrate that QT dispersion is useful in predicting short-term clinical outcome at discharge in AIS. Further, the magnitude of QT dispersion did not predict insular cortical stroke location.

The Challenges of a Vertical Evacuation Drill.

INTRODUCTION: Recent natural and infrastructural disasters, such as Hurricanes Sandy (2012) and Katrina (2005) and the Northeastern power outage of 2003, have emphasized the need for hospital staff to be trained in disaster management and response. Even an internal hospital disaster may require the safe and efficient evacuation and transfer of patients with varying medical conditions and complications. A notably susceptible population is renal transplant patients, including those with post-transplant complications. HYPOTHESIS: This descriptive study evaluated staff performance of a vertical evacuation drill of renal transplant patients at State University of New York (SUNY) Downstate Medical Center - University Hospital Brooklyn (UHB; Brooklyn, New York USA). METHODS: Thirteen standardized patients, 12 of whom received a renal transplant, with varying medical histories, ambulatory ability, and mental status were vertically evacuated by the transplant staff from the eighth floor to the ambulance entrance on the ground floor. Non-ambulatory patients were transported on portable evacuation sleds. RESULTS: All patients were evacuated successfully within 3.5 hours. On a post-drill evaluation form, drill participants self-reported largely positive results concerning their own role in the drill and the evacuation drill itself. Drill evaluators observed very different results, including staff reticence, poor training retention, and lack of leadership. CONCLUSION: Despite encouraging post-drill evaluation results from the participants, the evacuation drill highlighted several immediate deficiencies. It also demonstrated a significant discrepancy in performance perception between the drill participants and the drill evaluators.SalwayRJ, AdlerZ, WilliamsT, NwokeF, RoblinP, ArquillaB. The challenges of a vertical evacuation drill. Prehosp Disaster Med. 2019;34(1):25-29.

Stroke and Etonogestrel/Ethinyl Estradiol Ring (NuvaRing): Clinical, Radiological, and Prognostic Features.

BACKGROUND: A recent study found that NuvaRing (a vaginal contraceptive ring containing 15 µg ethinyl estradiol and 120 µg etonogestrel) has 2.5 times increased relative risk of thrombotic stroke compared to nonuse. OBJECTIVE: We studied a case series of 19 such patients as well as prior published case reports to clarify clinical, radiological, and prognostic features. METHODS: Medical records and imaging for 18 cases were initially systematically reviewed for consultation in a class action lawsuit. One case was seen personally outside of litigation. All 19 cases were entered into a database detailing clinical, radiological, and prognostic features as well as other potential risk factors. A literature search identified 8 additional cases. RESULTS: Average age at stroke was 31.7 ± 9.8 years; average duration of NuvaRing use prior to stroke was 11.2 months. Arterial stroke occurred in 10 of 19 (52%); 1 of 10 (10%) was hemorrhagic. Venous sinus thrombosis was present in 11 of 19 (58%) on initial imaging; 6 of 11 (54%) were hemorrhagic. The most common presenting symptom was headache (7 of 19 [37%]) and motor weakness (7 of 19 [37%]). A hypercoagulable condition was present in 3 of 19 (16%); 3 of 19 (16%) had history of hypercoagulable disease in a first-degree relative. Mortality was .5%; 8 of 19 (42%) fully recovered and 3 of 19 (15%) were discharged to rehabilitation. CONCLUSIONS: In this largest case series of NuvaRing-associated stroke to date, approximately half of the strokes are venous and half are arterial. Stroke typically occurred within the first year of use, and as soon as 2 weeks after NuvaRing initiation.

Risk factors for pulmonary metastases from giant cell tumor of bone.

BACKGROUND: Giant cell tumor (GCT) of bone is a rare, benign, aggressive bone tumor with an unusual capacity to metastasize to the lung. It was the goal of this study to identify patient and treatment-specific variables associated with the development of pulmonary metastases of GCT of bone. METHODS: From 1980 to 2009, 291 patients with benign GCT of bone were treated at our institution, and 167 were followed for at least two years. Eleven (6.6%) of these 167 patients developed biopsy-confirmed pulmonary metastasis. All patients were evaluated relative to nine patient, disease, and treatment-specific variables. RESULTS: We identified four properties of benign GCT of bone associated with an increased risk of metastasis on univariate analysis: age at diagnosis, axial location of the primary GCT, primary Enneking stage-3 disease, and local recurrence. Multivariate analysis showed local recurrence to be an independent risk factor for pulmonary metastasis (adjusted odds ratio, 7.42). CONCLUSIONS: There is an increased risk of pulmonary metastasis of GCT of bone in patients who are younger, present with Enneking stage-3 disease, develop local recurrence, and/or present with axial disease. The mode of treatment was not found to be associated with the development of pulmonary metastasis.

Percutaneous radionuclide ablation of axial aneurysmal bone cysts.

OBJECTIVE: The purpose of our study was to retrospectively examine the efficacy of intralesional injection of 32P chromic phosphate, a beta-emitting colloidal radiopharmaceutical, in the treatment of aneurysmal bone cysts of the axial skeleton. Five patients with large aneurysmal bone cysts were managed with injection of 32P chromic phosphate into their tumors under CT guidance. With only a single minor complication, all lesions were observed to ossify on follow-up CT, with an average follow up of 2 years. CONCLUSION: CT-guided injection of axial aneurysmal bone cysts with 32P chromic phosphate leads to excellent local lesion control. In addition, the morbidity associated with this procedure is lower than that associated with surgical or other nonsurgical treatments.