Application of ATONA Amplifiers to the Measurement of Uranium Isotopic Ratios by Thermal Ionization Mass Spectrometry.

Uranium isotopic composition can provide valuable information about the history and provenance of a nuclear material; therefore, uranium isotopic analyses are frequently made in the nuclear forensics, safeguards, and environmental monitoring communities. These measurements have always presented challenges due to the extreme variability in the relative abundance between the major (235U, 238U) and minor (233U, 234U, 236U) isotopes of uranium. The recently developed ATONA (Atto- to Nano-Amp) amplification system paired with Faraday cup detectors has a large dynamic range and low noise floor making it ideal for measuring uranium isotopic ratios in materials of both natural and anthropogenic origin. A wide variety of certified reference materials were analyzed to investigate the utility of the ATONA amplification system for determining uranium isotopic composition in samples ranging from depleted to highly enriched. The ATONA amplifiers provide nearly an order of magnitude improvement in external reproducibility over 1011 Ω amplifiers when measuring the minor 234U/238U ratio in isotopically natural and depleted samples and when paired with a secondary electron multiplier can measure very low relative abundance uranium isotopes (i.e., 236U).

Postinjury Alcohol Use Is Associated With Prolonged Recovery After Concussion in NCAA Athletes.

OBJECTIVE: To determine whether alcohol use leads to prolonged clinical recovery or increased severity of concussion symptoms in National Collegiate Athletic Association (NCAA) athletes. DESIGN: Prospective observational study. SETTING: Clinical institutions. PARTICIPANTS: Athletes from the NCAA Concussion Assessment Research and Education consortium who sustained a concussion from 2014 to 2021. INTERVENTIONS: Athletes were divided into 2 groups, those reporting alcohol use postinjury and those reporting no alcohol use postinjury. MAIN OUTCOME MEASURES: Symptom recovery was evaluated as time (in days) from injury to clearance to return to unrestricted play (days until URTP). Severity of concussion symptoms was assessed using the Standardized Sport Concussion Assessment Tool (SCAT3) symptom severity, headache severity, difficulty concentrating, and difficulty remembering scores. These scores were taken a median of 6.6 [interquartile range (IQR) = 4.0-10] and 6 (IQR = 4.0-9.0) days after injury for those who did and did not consume alcohol postinjury respectively and compared with baseline SCAT3 scores. RESULTS: Four hundred eighty four athletes from the data set had complete data for exposure and outcome. The adjusted mean number of days until URTP for athletes reporting alcohol use postinjury [23.3; 95% confidence interval (CI), 20.0-27.2; days] was incidence rate ratio (IRR) 1.32 (95% CI, 1.12-1.55; P < 0.001) times higher than for athletes who reported no alcohol use postinjury [17.7 (95% CI, 16.1-19.3) days]. Postinjury alcohol was not associated with severity of concussion symptoms ( P 's < 0.05). CONCLUSION: Self-reported postinjury alcohol use is associated with prolonged recovery but not severity of concussion symptoms in collegiate athletes. This may inform future clinical recommendations regarding alcohol consumption after concussion.

Detectability of Small Low-Attenuation Lesions With Deep Learning CT Image Reconstruction: A 24-Reader Phantom Study.

BACKGROUND. Iterative reconstruction (IR) techniques are susceptible to contrast-dependent spatial resolution, limiting overall radiation dose reduction potential. Deep learning image reconstruction (DLIR) may mitigate this limitation. OBJECTIVE. The purpose of our study was to evaluate low-contrast detectability performance and radiation-saving potential of a DLIR algorithm in comparison with filtered back projection (FBP) and IR using a human multireader noninferiority study design and task-based observer modeling. METHODS. A dual-phantom construct, consisting of a low-contrast detectability module (21 low-contrast hypoattenuating objects in seven sizes [2.4-10.0 mm] and three contrast levels [-15, -10, -5 HU] embedded within liver-equivalent background) and a phantom, was imaged at five radiation exposures (CTDIvol range, 1.4-14.0 mGy; size-specific dose estimate, 2.5-25.0 mGy; 90%-, 70%-, 50%-, and 30%-reduced radiation levels and full radiation level) using an MDCT scanner. Images were reconstructed using FBP, hybrid IR (ASiR-V), and DLIR (TrueFidelity). Twenty-four readers of varying experience levels evaluated images using a two-alternative forced choice. A task-based observer model (detectability index [d']) was calculated. Reader performance was estimated by calculating the AUC using a noninferiority method. RESULTS. Compared with FBP and IR methods at routine radiation levels, DLIR medium and DLIR high settings showed noninferior performance through a 90% radiation reduction (except DLIR medium setting at 70% reduced level). The IR method was non-inferior to routine radiation FBP only for 30% and 50% radiation reductions. No significant difference in d' was observed between routine radiation FBP and DLIR high setting through a 70% radiation reduction. Reader experience was not correlated with diagnostic accuracy (R2 = 0.005). CONCLUSION. Compared with FBP or IR methods at routine radiation levels, certain DLIR algorithm weightings yielded noninferior low-contrast detectability with radiation reductions of up to 90% as measured by 24 human readers and up to 70% as assessed by a task-based observer model. CLINICAL IMPACT. DLIR has substantial potential to preserve contrast-dependent spatial resolution for the detection of hypoattenuating lesions at decreased radiation levels in a phantom model, addressing a major shortcoming of current IR techniques.

Amputation for Complex Regional Pain Syndrome: Meta-Analysis and Validation of a Histopathology Scoring System.

OBJECTIVE: Pathology can provide crucial insights into the etiology of disease. The goal of this review is to evaluate the rigor of histopathology reports of Complex Regional Pain Syndrome (CRPS). METHODS: A systematic search of multiple databases identified papers that described amputation for CRPS with pathology findings. Control pathology articles were randomly chosen from the same journals. Landmark articles in Surgical Pathology were previously identified. Papers were categorized by the use of histology: Anatomic (microscopic description), Diagnostic (binary result), and Substrate (special studies only). A novel Histopathology Score assigned 1 point for each of 10 History elements and 15 Pathology elements. All articles were scored and analyzed by appropriate statistics. RESULTS: The search identified 22 CRPS, 50 Control and 50 Landmark articles. Multivariable analysis of the Pathology Score showed a significantly higher score for Anatomic vs Non-Anatomic papers (Incidence Rate Ratio (IRR) 1.54, P < .001) and Landmark vs CRPS articles (IRR 1.39, P value .003). CRPS papers reported some elements infrequently: diagnostic criteria (31.8%), routine stain (50%), any clinic-pathologic correlation (40.9%), and sample size >2 (27.3%). CONCLUSIONS: The Pathology Score is a useful quality assessment tool to evaluate studies. As expected, Anatomic papers scored significantly higher than Non-Anatomic papers. CRPS papers had small sample sizes (median 1) and infrequent reporting of diagnostic criteria, routine stain, any clinical pathologic correlation. These particular elements are crucial for analyzing and reviewing pathologic features. The analysis explains why it is quite difficult to write a meaningful systematic review of CRPS histology at this time.

Accessing Photoredox Transformations with an Iron(III) Photosensitizer and Green Light.

Efficient excited-state electron transfer between an iron(III) photosensitizer and organic electron donors was realized with green light irradiation. This advance was enabled by the use of the previously reported iron photosensitizer, [Fe(phtmeimb)2]+ (phtmeimb = {phenyl[tris(3-methyl-imidazolin-2-ylidene)]borate}, that exhibited long-lived and luminescent ligand-to-metal charge-transfer (LMCT) excited states. A benchmark dehalogenation reaction was investigated with yields that exceed 90% and an enhanced stability relative to the prototypical photosensitizer [Ru(bpy)3]2+. The initial catalytic step is electron transfer from an amine to the photoexcited iron sensitizer, which is shown to occur with a large cage-escape yield. For LMCT excited states, this reductive electron transfer is vectorial and may be a general advantage of Fe(III) photosensitizers. In-depth time-resolved spectroscopic methods, including transient absorption characterization from the ultraviolet to the infrared regions, provided a quantitative description of the catalytic mechanism with associated rate constants and yields.

Correction: Water binding stabilizes stacked conformations of ferrocene containing sheet-like aromatic oligoamides.

Correction for 'Water binding stabilizes stacked conformations of ferrocene containing sheet-like aromatic oligoamides' by Ya-Zhou Liu et al., Org. Biomol. Chem., 2021, DOI: 10.1039/d1ob00580d.

Water binding stabilizes stacked conformations of ferrocene containing sheet-like aromatic oligoamides.

While water clusters play an essential role in the stability of biological structures, their ability to stabilize synthetic oligomers is less understood. We have synthesized a heptameric sheet-like aromatic oligoamide foldamer with ferrocene as turn unit. It shows strong interactions with water in the solid state and in solution. The water binding limits the fluxional processes resulting from the flexible ferrocene unit, highlighting the importance of such interactions for conformational studies on this class of molecule.

Kentucky pharmacists' perceptions regarding provision of hormonal contraception.

BACKGROUND: Although Kentucky pharmacists recently gained authority to provide protocol-driven care for 13 conditions, provision of prescription hormonal contraception (HC) services is not currently authorized. A board-approved protocol allowing for provision of nonprescription over-the-counter (OTC) emergency contraception (EC) was recently approved by the Kentucky Board of Pharmacy but has yet to be implemented. OBJECTIVES: The objectives of this study were (1) to assess Kentucky pharmacists' interest in providing prescription HC and OTC EC services via protocol and (2) to identify perceived benefits/barriers regarding provision of prescription HC. METHODS: An online questionnaire was disseminated electronically to a convenience sample of Kentucky pharmacists. The questionnaire collected (1) demographic information, (2) opinions regarding provision of prescription HC and OTC EC, and (3) perceived benefits and barriers regarding provision of prescription HC. For analysis, responses were limited to pharmacists in community-based practice. McNemar's test was used to identify statistically significant differences in support by dosage form. In addition, a multivariable logistic regression model was used to examine associations between demographic factors and support for pharmacist provision of prescription HC. RESULTS: We received 151 responses from community-based pharmacists. Support for provision of prescription HC was highest for oral (61%) and transdermal (54%) forms. We found no statistically significant differences in support among demographic factors other than number of years in practice, with more recent graduates being at higher odds of support. In addition, time, reimbursement, training, and belief in the need for pelvic exams were the most commonly cited barriers to implementation. With regard to OTC EC provision, pharmacists were largely supportive (62%) and confident in their abilities. CONCLUSIONS: Community-based pharmacists in Kentucky are supportive of provision of oral, vaginal, and transdermal prescription HC as well as OTC EC via protocol. Barriers, including time, reimbursement, training, and belief in the need for pelvic exams, should be addressed to increase support for prescription HC provision.

Structure-Dependent Guest Recognition with Flexible Ferrocene-Based Aromatic Oligoamide ß-Sheet Mimics.

A series of aromatic oligoamides incorporating an inherently flexible ferrocene dicarboxylic acid unit was synthesized. Solid state, solution, and computational studies on these systems indicated that the aromatic strands can adopt a syn parallel stacked conformation. This results in modular ß-sheet-like molecular clefts that display structure-dependent recognition of small polar molecules. NMR and theoretical studies of the host-guest interaction support an in cleft binding mode and allowed the selectivity of the oligomers to be rationalized on the basis of minor changes in functional-group presentation on the edge of the aromatic strands.

Balancing Ligand Flexibility versus Rigidity for the Stepwise Self-Assembly of M12 L24 via M6 L12 Metal-Organic Cages.

Non-covalent interactions are important for directing protein folding across multiple intermediates and can even provide access to multiple stable structures with different properties and functions. Herein, we describe an approach for mimicking this behavior in the self-assembly of metal-organic cages. Two ligands, the bend angles of which are controlled by non-covalent interactions and one ligand lacking the above-mentioned interactions, were synthesized and used for self-assembly with Pd2+ . As these weak interactions are easily broken, the bend angles have a controlled flexibility giving access to M2 (L1)4 , M6 (L2)12 , and M12 (L2)24 cages. By controlling the self-assembly conditions this process can be directed in a stepwise fashion. Additionally, the multiple endohedral hydrogen-bonding sites on the ligand were found to play a role in the binding and discrimination of neutral guests.

Water vapor exposure chamber for constant humidity and hydrogen and oxygen stable isotope composition.

RATIONALE: Water vapor exposure experiments have applications for studying water physisorption and chemisorption hydration and hydroxylation reactions on a wide variety of material surfaces. The stable isotopes of hydrogen and oxygen in the water molecule are useful tracers of water exchange mechanisms and/or rates in such vapor exposure experiments. METHODS: We designed and built a humidity chamber system that uses membrane-mediated liquid-vapor exchange of water followed by mixing with dry air to control the relative humidity of air and its δ2 H and δ18 O isotopic composition. We tested the stability and precision of the humidity and its isotopic composition on hourly to 90-day timescales. RESULTS: The humidity chamber design reported here is capable of providing relative humidity control to within ±1%, and consistent δ2 H and δ18 O values of the water vapor that are similar to our cavity ringdown spectroscopy (CRDS) measurement precision (δ2 Hvap ± 0.7‰ and δ18 Ovap ± 0.24‰). We quantify the isotopic enrichment effects of Rayleigh distillation in the system and provide information on water reservoir sizes large enough to buffer isotopic enrichment effects to within measurement precision. CONCLUSIONS: The humidity chamber design reported here provides a means to create constant δ2 H and δ18 O values over the course of an exposure experiment. The design has applications to a wide range of studies of water sorption on material surfaces from foods and pharmaceuticals to geological materials.

Establishment of a comprehensive drug overdose fatality surveillance system in Kentucky to inform drug overdose prevention policies, interventions and best practices.

BACKGROUND: According to the National Center for Health Statistics, Kentucky had the third highest drug overdose fatality rate in the nation in 2015 at 29.9 drug overdose fatalities per 100 000 population. OBJECTIVE: The elevated drug overdose fatality rate necessitated the development and implementation of a comprehensive multisource drug overdose fatality surveillance system (DOFSS). METHODS: DOFSS stakeholder work group members and data sources were identified, and memorandums of understanding were established. The following data sources were used to establish DOFSS: (1) death certificates; (2) autopsy reports; (3) toxicology result reports; (4) coroner reports; and (5) Kentucky All Schedule Prescription Electronic Reporting (KASPER) (prescription drug monitoring programme) data. Drug overdose poisonings were defined using Injury Surveillance Workgroup 7 definitions. Analyses were performed to investigate possible drug overdose-related health disparities for disabled drug overdose decedents and to characterise gabapentin in drug overdose deaths. RESULTS: DOFSS identified 2106 drug overdose poisoning fatalities in Kentucky for 2013-2014. Identification of specific drugs involved in drug overdose deaths increased from 75.8% using a single data source to 97.5% using multiple data sources. Disabled drug overdose decedents were significantly more likely to have an active prescription for drugs identified in their system compared with the non-disabled drug overdose decedents. Toxicology data showed increased gabapentin involvement in drug overdose deaths from 2.9% in 2013 to 17% in 2014. Alprazolam was found most often in combination with gabapentin (41%), along with various other benzodiazepines and prescription opioids. CONCLUSIONS: A comprehensive multisource DOFSS improved drug overdose fatality surveillance by increasing completeness of data and data quality. DOFSS is a model that can be considered by other states to enhance their efforts in tracking drug overdose fatalities, identifying new and emerging trends, and informing policies and best practices, to address and reduce drug overdoses.

Direct electrolytic dissolution of silicate minerals for air CO2 mitigation and carbon-negative H2 production.

We experimentally demonstrate the direct coupling of silicate mineral dissolution with saline water electrolysis and H2 production to effect significant air CO2 absorption, chemical conversion, and storage in solution. In particular, we observed as much as a 10(5)-fold increase in OH(-) concentration (pH increase of up to 5.3 units) relative to experimental controls following the electrolysis of 0.25 M Na2SO4 solutions when the anode was encased in powdered silicate mineral, either wollastonite or an ultramafic mineral. After electrolysis, full equilibration of the alkalized solution with air led to a significant pH reduction and as much as a 45-fold increase in dissolved inorganic carbon concentration. This demonstrated significant spontaneous air CO2 capture, chemical conversion, and storage as a bicarbonate, predominantly as NaHCO3. The excess OH(-) initially formed in these experiments apparently resulted via neutralization of the anolyte acid, H2SO4, by reaction with the base mineral silicate at the anode, producing mineral sulfate and silica. This allowed the NaOH, normally generated at the cathode, to go unneutralized and to accumulate in the bulk electrolyte, ultimately reacting with atmospheric CO2 to form dissolved bicarbonate. Using nongrid or nonpeak renewable electricity, optimized systems at large scale might allow relatively high-capacity, energy-efficient (<300 kJ/mol of CO2 captured), and inexpensive (<$100 per tonne of CO2 mitigated) removal of excess air CO2 with production of carbon-negative H2. Furthermore, when added to the ocean, the produced hydroxide and/or (bi)carbonate could be useful in reducing sea-to-air CO2 emissions and in neutralizing or offsetting the effects of ongoing ocean acidification.

Synthesis of 1,8-diazaanthracenes as building blocks for internally functionalized aromatic oligoamide foldamers.

The synthesis of a variety of 9-functionalized 1,8-diazaanthracene diesters and amino acids is described. Derivatization at the 9-position relies on facile reactions performed on the 9-chloro and 9-bromomethyl precursors. This has allowed the incorporation of nucleophilic or sensitive functional groups that otherwise cannot be incorporated under standard methods for synthesizing these compounds. Additionally, the synthesis of the protected amino acids via a high-yielding monosaponification and subsequent Curtius rearrangement has been accomplished on a multigram scale. These units, together with the functionalized derivatives, should prove to be useful monomers in the synthesis of aromatic oligoamide foldamers.

Body mass index, asthma and exhaled nitric oxide in U.S. adults, 2007-2010.

OBJECTIVE: Increases in asthma and obesity over the past three decades have led to speculation about a causal link between the two diseases. However, investigations of the relationship between body mass index (BMI) and fractional exhaled nitric oxide (FeNO) - a marker of eosinophilic airway inflammation - have produced mixed results. The purpose of this study was to evaluate the relationship between body mass index (BMI), asthma and FeNO in a sample of U.S. adults using data from the National Health and Nutrition Examination Surveys (NHANES) for 2007-2010. METHODS: We assessed the relationship between FeNO and BMI in subjects with and without asthma using categorical and continuous models for BMI. All models controlled for age, gender, ethnicity, household income-to-poverty ratio, atopy and current smoking. RESULTS: Adjusted asthma prevalence was positively associated with BMI, and subjects with asthma had higher adjusted FeNO levels than subjects without asthma. However, no association between FeNO and BMI was observed in either those with (ß = 0.002, p = 0.74) or without (ß = 0.0014, p = 0.51) asthma after adjusting for covariates. CONCLUSIONS: Our results suggest that in the U.S. adult population, BMI is not associated with eosinophilic airway inflammation.

Increasing the size of an aromatic helical foldamer cavity by strand intercalation.

The postsynthetic modulation of capsules based on helical aromatic oligoamide foldamers would be a powerful approach for controlling their receptor properties without altering the initial monomer sequences. With the goal of developing a method to increase the size of a cavity within a helix, a single-helical foldamer capsule was synthesized with a wide-diameter central segment that was designed to intercalate with a second shorter helical strand. Despite the formation of stable double-helical homodimers (K(dim)>10(7) M(-1)) by the shorter strand, when it was mixed with the single-helical capsule sequence, a cross-hybridized double helix was formed with K(a)>10(5) M(-1). This strategy makes it possible to direct the formation of double-helical heterodimers. On the basis of solution- and solid-state structural data, this intercalation resulted in an increase in the central-cavity size to give a new interior volume of approximately 150 Å(3).

Ultrasound-Assisted Spinal Anesthesia in a Patient with a Preexisting Lumbar Interspinous Spacer: A Case Report.

An interspinous spacer is a minimally invasive implantable device for the treatment of lumbar spinal stenosis. The in situ implant may prevent safe and successful spinal anesthesia because its position can obstruct the path of the spinal needle. Lumbar neuraxial ultrasonography has been shown to aid in performance of neuraxial anesthesia in patients with challenging anatomy. Currently, there are no reported cases of ultrasound-assisted spinal anesthesia in patients with interspinous spacers. We present a case in which ultrasonography assisted the successful administration of a spinal anesthetic by avoiding an indwelling lumbar interspinous spacer.

Association between perioperative non-steroidal anti-inflammatory drug use and cardiovascular complications after non-cardiac surgery in older adult patients.

BACKGROUND: We investigated in older adult non-cardiac surgical patients whether receipt of perioperative non-steroidal anti-inflammatory drugs (NSAIDs) is associated with increased incidence of postoperative cardiovascular complications. METHODS: We retrospectively extracted the information for patients with age ≥  65 years who had inpatient non-cardiac surgery with a duration of ≥  1 h from the American College of Surgeons-National Surgical Quality Improvement Program registry data acquired at the University of Washington Medical Center. We compared patients who received NSAIDs perioperatively to those who did not receive NSAIDs, on the two composite outcomes: (1) the incidence of postoperative cardiovascular complications within 30 days of the surgery, and (2) the incidence of combined postoperative gastrointestinal and renal complications, and length of postoperative hospital stay. We used separate multivariable logistic regression models to analyze the two composite outcomes and a Poisson regression model for the length of hospital stay. RESULTS: The receipt of perioperative NSAIDs was not associated with postoperative cardiovascular complications (estimated odds ratio (OR), 1.78; 95% confidence interval (CI), 0.97 to 3.25; P =  0.06), combined renal and gastrointestinal complications (estimated OR, 1.30; 95% CI, 0.53 to 3.20; P =  0.57), and length of postoperative hospital stay in days (incidence rate ratio, 1.06; 95% CI, 0.93 to 1.21; P =  0.39). CONCLUSIONS: In older adult non-cardiac surgical patients, receipt of perioperative NSAIDs was not associated with increased incidences of postoperative cardiovascular complications, and renal and gastrointestinal complications within 30 days after surgery, or length of postoperative hospital stay.

Oxygen Isotope and Fluorine Impurity Signatures during the Conversion of Uranium Ore Concentrates to Nuclear Fuel.

Within the front end of the nuclear fuel cycle, many processes impart forensic signatures. Oxygen-stable isotopes (δ18O values) of uranium-bearing materials have been theorized to provide the processing and geolocational signatures of interdicted materials. However, this signature has been minimally utilized due to a limited understanding of how oxygen isotopes are influenced during uranium processing. This study explores oxygen isotope exchange and fractionation between magnesium diuranate (MDU), ammonium diuranate (ADU), and uranyl fluoride (UO2F2) with steam (water vapor) during their reduction to UOx. The MDU was precipitated from two water sources, one enriched and one depleted in 18O. The UO2F2 was precipitated from a single water source and either directly reduced or converted to ADU prior to reduction. All MDU, ADU, and UO2F2 were reduced to UOx in a 10% hydrogen/90% nitrogen atmosphere that was dry or included steam. Powder X-ray diffraction (p-XRD) was used to verify the composition of materials after reduction as mixtures of primarily U3O8, U4O9, and UO2 with trace magnesium and fluorine phases in UOx from MDU and UO2F2, respectively. The bulk oxygen isotope composition of UOx from MDU was analyzed using fluorination to remove the lattice-bound oxygen, and then O2 was subsequently analyzed with isotope ratio mass spectrometry (IRMS). The oxygen isotope compositions of the ADU, UO2F2, and the resulting UOx were analyzed by large geometry secondary ion mass spectrometry (LG-SIMS). When reduced with steam, the MDU, ADU, and UO2F2 experienced significant oxygen isotope exchange, and the resulting δ18O values of UOx approached the values of the steam. When reduced without steam, the δ18O values of converted ADU, U3O8, and UOx products remained similar to those of the UO2F2 starting material. LG-SIMS isotope mapping of F impurity abundances and distributions showed that direct steam-assisted reduction from UO2F2 significantly removed F impurities while dry reduction from UO2F2 led to the formation of UOx that was enhanced in F impurities. In addition, when UO2F2 was processed via precipitation to ADU and calcination to U3O8, F impurities were largely removed, and reductions to UOx with and without steam each had low F impurities. Overall, these findings show promise for combining multiple signatures to predict the process history during the conversion of uranium ore concentrates to nuclear fuel.