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Low-field nuclear magnetic resonance (NMR) relaxation is a promising non-invasive technique for characterizing solid–liquid interactions within functional porous materials. However, the ability of the solid–liquid interface to enhance adsorbate relaxation rates, known as the surface relaxivity, in the case of different solvents and reagents involved in various chemical processes has yet to be evaluated in a quantitative manner. In this study, we systematically explore the surface relaxation characteristics of 10 liquid adsorbates (cyclohexane, acetone, water, and 7 alcohols, including ethylene glycol) confined within mesoporous silicas with pore sizes between 6 and 50 nm using low-field (12.7 MHz) two-dimensional 1H T1–T2relaxation measurements. Functional-group-specific relaxation phenomena associated with the alkyl and hydroxyl groups of the confined alcohols are clearly distinguished; we report the dependence of both longitudinal (T1) and transverse (T2) relaxation rates of these 1H-bearing moieties on pore surface-to-volume ratio, facilitating the quantification and assignment of surface relaxivity values to specific functional groups within the same adsorbate molecule for the first time. We further demonstrate that alkyl group transverse surface relaxivities correlate strongly with the alkyl/hydroxyl ratio of the adsorbates assessed, providing evidence for a simple, quantitative relationship between surface relaxivity and interfacial chemistry. Overall, our observations highlight potential pitfalls in the application of NMR relaxation for the evaluation of pore size distributions using hydroxylated probe molecules, and provide motivation for the exploration of nuclear spin relaxation measurements as a route to adsorbate identity within functional porous materials.

Artificial habitat for cavity nesting birds can provide excellent opportunities for research and conservation efforts but may expose species to the negative impacts of warming ambient temperatures with climate change. Artificial nest boxes have been successfully used to monitor the breeding activity of the Cassin's auklet (Ptychoramphus aleuticus), a small burrow‐nesting seabird, on Southeast Farallon Island (SEFI) since 1971. Mean monthly ambient air temperatures on SEFI during the summer months have increased at an annual rate of roughly 0.03°C from 1971 to 2022, along with an increase in the number of extreme heat days and average maximum temperature, confirming a warming trend at this seabird colony. Given a projected increase in global temperature, we assessed the effectiveness of traditional wooden nest boxes vs. newer ceramic modules at buffering external ambient air temperatures in normal and extreme heat days across a gradient of microclimates on SEFI. Results from fitting linear mixed effects models indicated that, on average, internal temperatures of wooden and ceramic nests (of comparable size and shape) exhibited similar rates of deviation from ambient air temperature of approximately 0.15°C, even during extreme heat events. Ceramic modules did keep nest chambers cooler by approximately 1.2°C than wooden boxes during extreme events at the warmer, drier southern location of the island. Our results can help guide future efforts to design artificial nests that can effectively provide habitat for seabirds as ambient temperatures increase. [ABSTRACT FROM AUTHOR]

Objective: To compare the effect of virtual and in-person head and neck physical examination training events on medical student confidence in performing examination maneuvers and seeking mentorship from otolaryngology faculty and residents.Methods: Training events were held with first-year medical student volunteers in 2020 (in-person) and 2021 (virtual). Participants in both cohorts were given didactics on head and neck cancer, trained to perform a head and neck physical examination, and demonstrated their clinical skills to otolaryngology faculty and residents. Pre- and post-training surveys were utilized to assess the following outcomes: participant head and neck cancer knowledge, confidence in performing examination maneuvers, and confidence in seeking mentorship in otolaryngology. Differences in outcomes between training settings were assessed by comparing participant survey responses pre- and post- training.Results: Both in-person and virtual training modalities improved participant confidence in performing the physical examination. There was no significant difference in the degree of improvement between training types. In-person training significantly increased participant confidence in seeking mentorship from otolaryngology faculty and residents (P= .003), while virtual training did not (P= .194).Conclusion: Virtual training modalities are feasible methods of teaching the head and neck physical examination. Instruction through a video conferencing platform has the potential to be incorporated into traditional in-person medical education in a permanent fashion. This pilot study can inform future studies directly comparing in-person and virtual physical examination training modalities.

IMPORTANCE: The gold-standard treatment for laryngeal dystonia (LD) and essential tremor of the vocal tract (ETVT) is botulinum toxin (BoNT) chemodenervation. Although safe and effective, it is not curative, and periodic injections are required. Some medical insurance companies only cover injections at a 3-month interval, though some patients benefit from injections more frequently. OBJECTIVE: To determine the proportion and characteristics of patients who receive BoNT chemodenervation treatment in intervals shorter than 90 days. DESIGN, SETTING, AND PARTICIPANTS: This retrospective cohort study across 3 quaternary care neurolaryngology specialty practices in Washington and California recruited patients who underwent at least 4 consecutive laryngeal BoNT injections for LD and/or ETVT in the past 5 years. Data were collected from March through June 2022 and analyzed from June through December 2022. EXPOSURE: Laryngeal BoNT treatment. MAIN OUTCOMES AND MEASURES: Biodemographic and clinical variables, injection characteristics, evolution during the 3 interinjection intervals, and lifetime laryngeal BoNT treatment data were collected from patient medical records. Logistic regression was used to assess association to the short-interval outcome, defined as an average injection interval shorter than 90 days. RESULTS: Of 255 patients included from the 3 institutions, 189 (74.1%) were female, and the mean (SD) age was 62.7 (14.3) years. The predominant diagnosis was adductor LD (n = 199 [78.0%]), followed by adductor dystonic voice tremor (n = 26 [10.2%]) and ETVT (n = 13 [5.1%]). Seventy patients (27.5%) received short-interval injections (<90 days). The short-interval group was younger than the long-interval group (≥90 days), with a mean (SD) age of 58.6 (15.5) years and 64.2 (13.5) years, respectively, and a mean difference of −5.7 years (95% CI, −9.6 to −1.8 years). There were no patient-related differences between the short- and long-interval groups in terms of sex, employment status, or diagnosis. CONCLUSIONS AND RELEVANCE: This cohort study demonstrated that while insurance companies often mandate a 3-month or greater interval for BoNT chemodenervation financial coverage, there is a considerable subset of patients with LD and ETVT who receive short-interval treatment to optimize their vocal function. Short-interval chemodenervation injections demonstrate a similar adverse effect profile and do not appear to predispose to resistance through antibody formation.

Natural gas containing trace amounts of water is frequently liquefied at conditions where aqueous solids are thermodynamically stable. However, no data are available to describe the kinetics of aqueous solid formation at these conditions. Here, we present experimental measurements of both solid formation kinetics and solid–fluid equilibrium for trace concentrations of (12 ± 0.7) ppm water in methane using a stirred, high-pressure apparatus and visual microscopy. Along isochoric pathways with cooling rates around 1 K·min–1, micron-scale aqueous solids were observed to form at subcoolings of (0.3–8.6) K, relative to an average equilibrium melting temperature of (253 ± 1.9) K at (8.9 ± 0.08) MPa; these data are consistent with predicted methane hydrate dissociation conditions within the uncertainty of both the experiment and model. The 36 measured formation events were used to construct a cumulative formation probability distribution, which was then fitted with a model from Classical Nucleation Theory, enabling the extraction of kinetic and thermodynamic nucleation parameters. While the resulting nucleation parameter values were comparable to those published for methane hydrate formation in bulk-water systems, the observed growth kinetics were distinctly different with only a small percentage of the water in the system converting into micron-scale solids over the experimental time scale. These results may help explain how cryogenic heat exchangers in liquefied natural gas facilities can operate for long periods without blockages forming despite being at very high subcoolings for aqueous solids.

High magnetic field NMR spectroscopy featuring the use of superconducting magnets is a powerful analytical technique for the detection of honey adulteration. Such high field NMR systems are, however, typically housed in specialised laboratories, require cryogenic coolants, and necessitate specialist training to operate. Benchtop NMR spectrometers featuring permanent magnets are, by comparison, significantly cheaper, more mobile and can be operated with minimal expertise. The lower magnetic fields used in such systems, however, result in limited spectral resolution, which diminishes their ability to perform quantitative composition analysis. These limitations may be overcome by implementing a recently developed field-invariant model-based fitting method which is defined by the underlying quantum mechanical properties of the nuclear spin system; this method is applied here to quantify the sugar composition of honey using benchtop 1H NMR (43 MHz) spectroscopy. The detection of adulteration of 26 honey samples with brown rice syrup is quantitatively demonstrated to a minimum adulterant concentration of 5 wt%. Honey adulteration with corn syrup, glucose syrup and wheat syrup was also quantitatively detected using this approach. Our NMR detection of adulteration was shown to be invariant with time over 60 days of storage.

* In August, the Pentagon began its Nuclear Posture Review, a six-month process of comprehensively evaluating the U.S. nuclear arsenal and strategic doctrine. The review, which every U.S. president has [...]

Objective: Medical podcasts are becoming increasingly available; however, it is unclear how these new resources are being used by trainees or whether they influence clinical practice. This study explores the preferences and experiences of otolaryngology residents with otolaryngology-specific podcasts, and the impact of these podcasts on resident education and clinical practice.Methods: An 18-question survey was distributed anonymously to a representative junior (up to post-graduate year 3) and senior (post-graduate year 4 or greater) otolaryngology residents at most programs across the US. Along with demographic information, the survey was designed to explore the preferences of educational materials, podcast listening habits and motivations, and influence of podcasts on medical practice. Descriptive statistics and student t-tests were used to analyze the results.Results: The survey was distributed to 198 current otolaryngology residents representing 94% of eligible residency programs and was completed by 73 residents (37% response rate). Nearly 3-quarters of respondents reported previous use of otolaryngology podcasts, among which 83% listen at least monthly. Over half of residents changed their overall clinical (53%) and consult (51%) practice based on podcast use. Residents rank-ordered listening to podcasts last among traditional options for asynchronous learning, including reading textbooks and watching online videos.Conclusions: While other asynchronous learning tools remain popular, most residents responding to this survey use podcasts and report that podcasts influence their clinical practice. This study reveals how podcasts are currently used as a supplement to formal otolaryngology education. Results from the survey may inform how medical podcasts could be implemented into resident education in the future.

Objectives: Over the past 30 years laryngology fellowships have grown in number and diversity. This study investigated the career trajectories of recent laryngology fellowship graduates with the purpose of informing residents considering fellowship.Study design: Cross-sectional surveySetting: Academic medical centerMethods: The directors of all 27 US laryngology fellowships that graduated/recruited fellows from 2010 to 2019 were contacted, and a list of former fellows was compiled. A short survey was administered in person or via email or phone. Additional data was gathered through internet searches.Results: One hundred eighty-three fellows were identified having completed American laryngology fellowships between 2010 and 2019 (100M:83F). Fifteen percent now practice internationally and 68% are in academic practice. A higher proportion of women than men enter laryngology fellowship after otolaryngology residency. One hundred twenty-nine fellows responded to our survey. Two-thirds of former fellows report current participation in laryngology research. Seventy-two percent of former fellows are still in their first job after fellowship and 53% believe they have their ideal practice. Women were more likely to enter academics than men after laryngology fellowship. Responders were overwhelmingly satisfied with their fellowship experience, with 95% saying they would choose to pursue fellowship training again.Conclusions: Most former laryngology fellows enter academia, contribute to laryngology research, practice away from their training institution, and believe they have found their ideal practice. The results of this study may be useful to residents considering fellowship training, centers considering establishing laryngology fellowships, and practices recruiting fellowship graduates.

The growth and aggregation potential of gas hydrates in subsea flowlines are critical risk parameters for oil and gas production flow assurance. Hydrate interfaces may be exposed to water and hydrocarbon phases where natural oil surfactants may have a tendency to adsorb. The cohesion and growth between cyclopentane hydrate (structure II hydrate) particles exposed to natural oil surfactants in modified hydrocarbon phases were studied using a micromechanical force (MMF) apparatus. An Australian crude oil (unmodified), isolated asphaltenes and resins obtained via SARA fractionation and, when added to the cyclopentane phase, reduced the hydrate cohesive force by up to 98% (<1 wt % of additive). During cases of flowline shutdown, hydrate particles may have the opportunity to sinter with each other, whereby the force required to separate particles may be representative of the shear requirement to fracture aggregates in a flowline restart. The force required to separate hydrate particles was measured as a function of interparticle contact time to quantify the activity of naturally present surface-active material at resisting sintering-type phenomena. The results indicate that naturally occurring species adsorb to hydrate interfaces and decrease the extent of sintering between particles across the range of contact times studied. In a modified experimental setup, cyclopentane hydrate film growth rate measurements illustrated a comparable suppression in hydrate film growth rate to previous work. These results indicate that naturally derived surfactants from some crude oils may stabilize both water-in-oil emulsions and hydrate-in-oil suspensions. The elimination of otherwise necessary chemical management may be suitable if natural oil surfactants can perform suitable flow assurance functions.

Objective: Patients with subglottic stenosis (SGS) present with varied degree of breathing complaints. The dyspnea index (DI) is a 10-question patient-reported outcome measure designed to measure the severity of upper airway obstruction. We set out to determine whether pulmonary function tests or clinician-reported degree of stenosis best predicted DI scores.Methods: Thirty patients with SGS were retrospectively reviewed over a 6-year period. One visit from each patient was included. Data including peak expiratory flow rate (PEFR), body-mass index (BMI), clinician-reported degree of stenosis, and DI scores were reviewed. Multiple linear regression was performed to determine how degree of stenosis and PEFR % predicted the variation in DI score.Results: PEFR % better predicted DI scores compared to degree of stenosis (partial correlation −0.32 vs 0.17). After stepwise elimination, PEFR % remained in the regression and was significantly associated with DI scores (F[1, 29] = 9.38, P= .005). BMI did not demonstrate a linear relationship with DI scores and was not included in the regression (r= −.02). The PEFR % unstandardized coefficient was −0.25 (95% CI: −0.42 to −0.08, P= .005). The model predicts that a 4% increase in the PEFR % results in a 1-point decrease in the DI score (95% CI: −1.68 to −0.32).Conclusion: This study suggests that pulmonary function tests may be a better in-office measure to substantiate the severity of symptoms in patients with SGS.

Conventional water-in-oil emulsion studies where shear energy intensity and duration are applied to achieve ‘equilibrium’ emulsion droplet properties may not represent partial emulsion conditions observed in single pass flow through Inflow Control Device (ICD) orifices. Our experiments provide data expected to improve emulsion transport models for partial emulsification processes expected in well completion and production tubulars. Development of a novel flow adaptor apparatus is described together with a laboratory homogeniser enables independent control of shear intensity and duration together with input water volume fraction. The emulsions formed are characterised with a benchtop Nuclear Magnetic Resonance spectrometer for water content and droplet size, viscosity by a rotating bob viscometer and free water/emulsion proportion by optical photography. Experimental results confirmed partial emulsification above 30% V/V, as observed in both previous ICD flow experiments and field observations. Electrical conductivity measurements of the emulsions produced indicated that partial emulsification comprising an oil external emulsion phase together with free water, rather than emulsion inversion, occurs in this system.

Abstract Postirradiation sarcomas of the head and neck are rare. When they do occur, most appear at least 10 years following radiation therapy. We report three cases of early-onset (1, [...]

Solid–fluid interactions underpin the efficacy of functional porous materials across a diverse array of chemical reaction and separation processes. However, detailed characterization of interfacial phenomena within such systems is hampered by their optically opaque nature. Motivated by the need to bridge this capability gap, we report low-magnetic-field two-dimensional (2D) 1H nuclear spin relaxation measurements as a noninvasive probe of adsorbate identity and interfacial dynamics, exploring the relaxation characteristics exhibited by liquid hydrocarbon adsorbates confined to a model mesoporous silica. For the first time, we demonstrate the capacity of this approach in distinguishing functional group-specific relaxation phenomena across a diverse range of alcohols and carboxylic acids employed as solvents, reagents, and liquid hydrogen carriers, with distinct relaxation responses assigned to the alkyl and hydroxyl moieties of each confined liquid. Uniquely, this relaxation behavior is shown to correlate with adsorbate acidity, with the observed relationship rationalized on the basis of surface–adsorbate proton-exchange dynamics. Our results demonstrate that nuclear spin relaxation provides a molecular-level perspective on sorbent/sorbate interactions, motivating the exploration of such measurements as a unique probe of adsorbate identity within optically opaque porous media.

Objectives: To examine whether social determinants of health (SDH) factors are associated with time to diagnosis, treatment selection, and time to recurrent surgical intervention in idiopathic subglottic stenosis (iSGS) patients.Methods: Adult patients with diagnosed iSGS were recruited prospectively (2015-2017) via clinical providers as part of the North American Airway Collaborative (NoAAC) and via an online iSGS support community on Facebook. Patient-specific SDH factors included highest educational attainment (self-reported), median household income (matched from home zip code via U.S. Census data), and number of close friends (self-reported) as a measure of social support. Main outcomes of interest were time to disease diagnosis (years from symptom onset), treatment selection (endoscopic dilation [ED] vs cricotracheal resection [CTR] vs endoscopic resection with adjuvant medical therapy [ERMT]), and time to recurrent surgical intervention (number of days from initial surgical procedure) as a surrogate for disease recurrence.Results: The total 810 participants were 98.5% female, 97.2% Caucasian, and had a median age of 50 years (IQR, 43-58). The cohort had a median household income of $62 307 (IQR, $50 345-$79 773), a median of 7 close friends (IQR, 4-10), and 64.7% of patients completed college or graduate school. Education, income, and number of friends were not associated with time to diagnosis via multivariable linear regression modeling. Univariable multinominal logistic regression demonstrated an association between education and income for selecting ED versus ERMT, but no associations were noted for CTR. No associations were noted for time to recurrent surgical procedure via Kaplan Meier modeling and Cox proportional hazards regression.Conclusions: Patient education, income, and social support were not associated with time to diagnosis or time to disease recurrence. This suggests additional patient, procedure, or disease-specific factors contribute to the observed variations in iSGS surgical outcomes.

Objective. To compare three methods of computing the national requirements for otolaryngologists in 1994 and 2010. Data Sources. Three large HMOs, a Delphi panel, the Bureau of Health Professions (BHPr), and published sources. Study Design. Three established methods of computing requirements for otolaryngologists were compared: managed care, demand-utilization, and adjusted needs assessment. Under the managed care model, a published method based on reviewing staffing patterns in HMOs was modified to estimate the number of otolaryngologists. We obtained from BHPr estimates of work force projections from their demand model. To estimate the adjusted needs model, we convened a Delphi panel of otolaryngologists using the methodology developed by the Graduate Medical Education National Advisory Committee (GMENAC). Data Collection/Extraction Methods. Not applicable. Principal Findings. Wide variation in the estimated number of otolaryngologists required occurred across the three methods. Within each model it was possible to alter the requirements for otolaryngologists significantly by changing one or more of the key assumptions. The managed care model has a potential to obtain the most reliable estimates because it reflects actual staffing patterns in institutions that are attempting to use physicians efficiently. Conclusions. Estimates of work force requirements can vary considerably if one or more assumptions are changed. In order for the managed care approach to be useful for actual decision making concerning the appropriate number of otolaryngologists required, additional research on the methodology used to extrapolate the results to the general population is necessary. Key Words. Work force requirements, otolaryngologists, health professions education, physician supply, For several decades policymakers have debated whether the United States is training the appropriate number of physicians and the appropriate mix of generalists and specialists. Interest in this issue intensified [...]

Abstract

The transfer of words from one language to another is ubiquitous in many of the world’s languages. While loanwords have a rich literature in the fields of historical linguistics, language contact, and sociolinguistics, little work has been done examining how loanwords are processed by bilinguals with knowledge of both the source and recipient languages. The present study uses pupillometry to compare the online processing of established loanwords in Puerto Rican Spanish to native Spanish words by highly proficient Puerto Rican Spanish-English bilinguals. Established loanwords elicited a significantly larger pupillary response than native Spanish words, with the pupillary response modulated by both the frequency of the loanword itself and of the native Spanish counterpart. These findings suggest that established loanwords are processed differently than native Spanish words and compete with their native equivalents, potentially due to both intra- and inter-lingual effects of saliency.

Cemented paste backfill (CPB) technology is a favored approach with which to dispose of solid mining waste in underground voids. Knowledge of the evolving material properties of CPB under the conditions of hypersaline water-initiated hydration is crucial for its enhanced utilization as passive support material in mining operations. Here, we investigate the hydration behavior of CPB samples using 1H NMR T1–T2correlation measurements at a low magnetic field (2 MHz), contrasting hypersaline and tap-water-hydrated CPB comprising 5 wt % cement binder for up to 28 days. Our results reveal a complex and rapidly evolving hierarchical pore network within the CPB structures. Relaxation peaks are assigned to a combination of pore water populations and pore-to-pore exchange dynamics with the aid of additional relaxation-exchange correlation measurements. Differences in the hydration behavior of hypersaline and tap-water-hydrated materials are further discussed in terms of observed exchange processes and evolving pore surface chemistry.

Natural gas hydrates have attracted interest as a potential future energy resource to meet the expected growth in the global energy demand. One of the key challenges to be tackled for commercial production is gas hydrate re-formation in production lines. Such hydrate blockages have been a major concern of flow assurance in the oil and gas industries, and typically occur during start-up, shut-in, and restart operations. This study sheds light on the behavior of methane hydrate slurries in pure water systems under shut-in conditions and their transition to solid blockages during system restart: a key risk factor in gas hydrate production. Flowloop experiments were conducted to measure the critical stress required to restart flow in hydrate slurries, which were accompanied by visual observations using an in-line video camera. A transition from smooth restart to a critical stress requirement was observed at 4–5 vol % of hydrate; visually, this corresponded to complete occupancy of the flow cross section with porous aggregated hydrate particles in a loosely packed network. The critical stress increased with higher hydrate volume fractions per the behavior of yield stress for a general suspension: it was not affected by the shut-in period, suggesting that annealing was not a factor at the volume fractions measured. Further, hydrate blockage occurred in several restart operations at approximately 18 vol % of hydrate even though the video camera had captured partial yielding before the blockage occurred. These results show a progression in slurry behavior as a function of hydrate volume fraction, offering insights into varied mechanisms for blockage formation, and operational strategies to minimize blockage risk.

Introduction Robotic colectomy could reduce morbidity and postoperative recovery over laparoscopic and open procedures. This comparative review evaluates colectomy outcomes based on surgical approach at a single community institution.Methods A retrospective review of all patients who underwent colectomy by a fellowship-trained colon and rectal surgeon at a single institution from 2015 through 2019 was performed, and a cohort developed for each approach (open, laparoscopic, and robotic). 30-day outcomes were evaluated. For dichotomous outcomes, univariate logistic regression models were used to quantify the individual effect of each predictor of interest on the odds of each outcome. Continuous outcomes received a similar approach; however, linear and Poisson regression modeling were used, as appropriate.Results 115 patients were evaluated: 14% (n = 16) open, 44% (n = 51) laparoscopic, and 42% (n = 48) robotic. Among the cohorts, there was no statistically significant difference in operative time, rate of reoperation, readmission, or major complications. Robotic colectomies resulted in the shortest length of stay (LOS) (Kruskal-Wallis P< .0001) and decreased estimated blood loss (EBL) (Kruskal-Wallis P= .0012). Median age was 63 years (interquartile range [IQR] 53-72). 54% (n = 62) were female. Median American Society of Anesthesiologists physical status classification was 3 (IQR 2-3). Median body mass index was 28.67 (IQR 25.03-33.47). A malignant diagnosis was noted on final pathology in 44% (n = 51).Conclusion Among the 3 approaches, there was no statistically significant difference in 30-day morbidity or mortality. There was a statistically significant decreased LOS and EBL for robotic colectomies.

Physician burnout has become a hot topic in the popular press. It seems that a day doesn't pass without seeing an email, editorial, or published research article on the topic, [...]

The May 2018 Horn Call article concerning IHS Workshop I brought back memories, some of which may be interesting to younger attendees of the recently completed IHS Workshop L.In 1969 [...]

NMR relaxation analysis provides a unique and non-invasive probe of fluid dynamics within porous materials, and may be applied to the interpretation of a wide variety of material and interfacial characteristics. Here, we report two-dimensional 1H T1−T2relaxation correlation measurements of a range of three-carbon adsorbates (1-propanol, 2-propanol and propanoic acid) imbibed within the mesoporous metal oxide gamma-alumina. Our data, acquired across field strengths of 2 MHz, 12.7 MHz and 43 MHz, clearly reveal two populations in each measurement, identified as the alkyl and hydroxyl moieties of each adsorbate. These results expand the range of materials in which such functional group resolved relaxation is known to occur, and demonstrate the clear persistence of such phenomena using a range of typical benchtop NMR systems employed to study fluid-saturated porous media.

IMPORTANCE: One-third of singers and vocal professionals report experiencing a benefit from empirical vitamin B12 injections for improvement of mild singing-related symptoms (eg, reduced stamina, vocal fatigue, and effort). However, there is no objective evidence to support or refute these claims. OBJECTIVE: To assess the presence and magnitude of the effect of empirical vitamin B12 injection on the vocal performance of singers. DESIGN, SETTING, AND PARTICIPANTS: A randomized, double-blind, placebo-controlled, crossover trial was conducted from November 7, 2017, to November 30, 2018, at an academic voice center among 20 active adult singers without dysphonia but with mild vocal symptoms. Individuals with known or suspected vitamin B12 deficiency or active or recent vitamin B12 treatment were excluded. Analysis was on a per-protocol basis. INTERVENTIONS: Participants were randomized to receive an intramuscular (deltoid) injection of either vitamin B12 (1000 μg of cyanocobalmin) or placebo (0.9% sodium chloride). After a washout period of at least 4 weeks, participants were crossed over to receive the opposite injection. Both the investigators and participants were blinded to the order of injections. MAIN OUTCOMES AND MEASURES: The participants completed the Singing Voice Handicap Index–10 (SVHI-10), the Voice Fatigue Index (VFI), and the Evaluation of the Ability to Sing Easily (EASE) before each injection and at intervals of 1 hour, 3 hours, 24 hours, 72 hours, and 1 week after the injection. The primary time point assessment was 72 hours after injection, and the SVHI-10 score was the primary outcome measure. RESULTS: Twenty singers (10 men; median age, 22 years [range, 19-42 years]) were enrolled. The improvements after either placebo or vitamin B12 injections were comparable to each other. At 72 hours after the vitamin B12 injection, the median difference in the SVHI-10 score was 1 (95% CI, –1 to 2) compared with 3 (95% CI, 0-4) after placebo. The median difference between differences at 72 hours between placebo and vitamin B12 injections were 1.5 (95% CI, –2 to 5) for the SVHI-10, 1 (95% CI, –9 to 9) for the VFI, and –1 (95% CI, –3 to 2) for the EASE. The improvements after both injections failed to reach the estimated minimal clinically important difference. Of the 20 participants, 4 (20%) reached the estimated minimal clinically important difference in their SVHI-10 score after 72 hours for both vitamin B12 and placebo injections. CONCLUSIONS AND RELEVANCE: This randomized, double-blind, placebo-controlled, crossover trial found that after empirical vitamin B12 injection to improve mild voice-related symptoms, the improvement in self-reported voice measures in singers shows no meaningful difference compared with placebo. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03437824

In subsea oil and gas production, a transition away from complete gas hydrate avoidance to risk-based hydrate management has the potential to offer cost savings and improved viability for new developments. Rigorous characterization of hydrate formation probability (via the measurement of statistically significant numbers of independent hydrate formation events) represents a crucial step toward accurate quantification of hydrate blockage risk. Such characterization is especially pertinent when deploying low-dosage kinetic hydrate inhibitors (KHIs), which, unlike thermodynamic hydrate inhibitors (THIs), affect hydrate formation kinetics rather than thermodynamic stability envelopes. Here, we demonstrate the use of a second-generation, Peltier-cooled, high-pressure, stirred, automated lag time apparatus (HPS-ALTA) to efficiently measure hydrate formation under conditions simulating a methane-dominant natural gas asset. Over 2500 hydrate formation events were measured using a low-salt-content brine, enabling the production of smooth, high-resolution hydrate probability distributions in the presence of three inhibitor chemical additives and combinations thereof (a corrosion inhibitor, a KHI, and a conventional THI). Beyond enabling rapid, high-fidelity testing of potential inhibitor interactions, the results explicitly demonstrate the ability to effectively manipulate formation probability boundaries via a combination of thermodynamic and kinetic inhibition effects. Such hybrid inhibition strategies can be used to achieve long induction times at operationally relevant formation temperatures (over 2 days at 2.5 °C in this study) and may be more beneficial and/or cost-effective than strategies focused on complete hydrate avoidance.

Background A randomized controlled trial of routine administration of pasireotide demonstrated decreased incidence of clinically significant postoperative pancreatic fistula (POPF). Recent studies have not replicated these results. A meta-analysis was performed to evaluate its efficacy in this setting.Methods Prospective trials utilizing pasireotide prophylactically after pancreatectomy were reviewed. The primary outcome was clinically significant POPF. Secondary outcomes included length of stay (LOS), readmission rates, and mortality. Study heterogeneity was assessed.Results Five studies totaling 1571 patients were identified. There was no difference in age, sex, or cancer rates. Pasireotide patients had smaller pancreatic ducts (P< .001) and softer glands (P= .04). For all pancreatectomies, there was no difference in POPF rates (odds ratio [OR] 0.84; 95% CI 0.60-1.16, P= .29). Patients undergoing distal pancreatectomy (OR 0.70; 95% CI 0.30-1.63, P= .41) had similar rates of POPF versus pancreaticoduodenectomy (PD) patients who experienced a lower incidence of POPF (OR 0.60; 95% CI 0.42-0.86, P= .006). Mortality rates and LOS were similar. Readmission rates were decreased with pasireotide (OR 0.61; 95% CI 0.44-0.85).Conclusions Routine administration of pasireotide did not decrease POPF rates for all pancreatectomies, but was associated with lower rates for PD, and decreased readmission rates. Further prospective, randomized studies are warranted.

Reliable measurements of oil-in-water (OiW) content is essential in the oil and gas industry. The current OiW analysis techniques deployed in the industry need frequent calibration and mostly depend on optical access to the sample. They are also limited in providing a thorough compositional examination of the oil content. Nuclear magnetic resonance (NMR) is a well-established analytical tool across a wide range of different fields. For the OiW analysis, NMR can provide a self-calibrated measurement, does not require optical access, and allows for quantitative analysis of aromatic and aliphatic hydrocarbon content at the ppm level. Here, a fully automated prototype combining a custom-built solid-phase extraction (SPE) platform for sample pre-concentration and a benchtop NMR spectrometer for quantitative OiW measurements is designed, built, and demonstrated. The novel automated apparatus has significant potential for field deployment and provides a reliable and reproducible analysis of OiW content consistent with common reference methods.

The production of methane (CH4) from natural gas hydrate deposits via molecular replacement by injected, thermodynamically more favorable, carbon dioxide (CO2) is a promising method of energy production and carbon sequestration. However, the viability of this technique is constrained by mass-transfer limitations, which are in turn associated with diffusion of the injected CO2into the hydrate-bearing sediment layers. Generally, the coupled heat- and mass-transfer phenomena associated with this replacement process in complex heterogeneous porous media are poorly understood. To facilitate the noninvasive pore-scale study of this replacement process (ultimately in sediment cores) using a range of nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI) techniques, a novel NMR-compatible sediment holder has been designed and constructed. Via the provision of centralized sample cooling, sample temperature control is achieved at high pressures while keeping the NMR magnet system at the required temperature. Hydrate formation and dissociation processes in model porous media were successfully investigated using a CH4/C2H6mixture and CO2. Novel one-dimensional (1D) MRI images of the residual liquid water and hydrocarbon gas were acquired during the hydrate formation and dissociation processes using a single-point ramped imaging with T1enhancement (SPRITE) MRI pulse sequence. Interleaved NMR T2relaxation measurements were also obtained to interrogate the pores sizes occupied by the residual water. From these results, the water distribution and subsequent hydrate-formation behavior have been spatially and temporally resolved throughout the porous media.

NMR T2relaxation times for fluids in a porous medium are, in principle, proportional to the relevant occupied pore size. Here, we exploit this relationship to monitor the pore size distribution occupied by methane (CH4) at 100 bar and room temperature in both sandstone and carbonate rock cores, while it is displaced by a range of miscible fluids: carbon dioxide (CO2), nitrogen (N2), nitrous dioxide (N2O), and helium (He). The process is then reversed, with methane being used to displace these injected fluids. Time-resolved T2distributions are thus able to probe the preference of the methane for smaller or larger pores during these core-flooding processes. In the cases of CO2and N2O, methane was found to preferentially occupy larger pores during both injection and displacement for both rock types. In the case of N2, no significant preferential pore size occupation was evident, whereas in the case of He, methane preferentially occupied smaller pores. For the fluids used in this work, preferential occupation of comparatively smaller pores during these displacement experiments correlated with a comparatively greater surface adsorption capacity.

Gas hydrates are ice-like solids that may form and aggregate in crude oil pipelines; in severe cases, the increase in frictional pressure drop may exceed the available driving force, resulting in a non-flowing (blockage) condition. To assess the severity of hydrate formation in oil- or condensate-dominant lines, a slurry viscosity model must be applied to and validated for hydrate-laden suspension. A well-known model, applied in industrial situations for hydrate slurry rheology, has been suggested to significantly underpredict apparent viscosity during the early and intermediate stages of hydrate blockage formation. Because hydrate particles suspended in the slurry may aggregate, this study interrogates their suspension rheology in two parts: The underlying suspension behavior was tested by injecting industrial anti-agglomerant (AA) chemicals, thereby identifying the contribution of particle aggregation for identical systems without AAs. A temperature-controlled high-pressure rheometer with a vane blade rotor was deployed, where hydrate-in-oil suspensions were formed from a metastable water-in-oil emulsion pressurized with methane. The results first illustrate that, at similar operating conditions, the addition of AAs reduced the hydrate growth rate by an order of magnitude and decreased the steady-state relative viscosity order of magnitude. After the hydrate volume fraction achieved a steady-state condition, the addition of AA suppressed the magnitude of the hydrate-in-oil slurry viscosity flow curve by an order of magnitude. Extrapolated to the infinite shear rate, the apparent viscosity behavior of hydrate-in-oil suspensions was compared to a range of rheological suspension models. The current industry model was indeed found to perform poorly, which may be due to assumptions of rigid and spherical particles; a revised suspension model considering arbitrarily shaped particles improved experimental predictions by between 50 and 60% for two crude oil systems.

Under high-pressure and low-temperature conditions, gas hydrate shells may form and grow at the interface of water droplets in water-in-oil emulsions. Such hydrate formation can enable downstream agglomeration and slurry viscosification, thus increasing the risk of hydrate blockage. Therefore, emulsion stability represents a critical parameter in understanding this overall flow behaviour. In this study, the impact of three common and widely-used industrial anti-agglomerants from three different suppliers (AA-1, AA-2 and AA-3—exact composition is commercially sensitive) on 30 wt% water-in-oil (W/O) emulsion stability was investigated. Bench-top nuclear magnetic resonance (NMR) pulsed field gradient (PFG) methods were used to measure the droplet size distributions (DSDs) of the W/O emulsions as a complement to bottle stability test. In the absence of hydrate anti-agglomerants, based on visual observation, 85% of the original W/O emulsion remained after 10 h. In the presence of AA-1 and AA-2, 94% of the original emulsion was retained; in contrast, AA-3 acted to destabilise the emulsion with only 64% of the original emulsion visually evident after 10 h. These results were substantiated by PFG NMR measurements which showed substantial changes in droplet size as a function of sample height for the W/O emulsion formulated with AA-3. Interestingly the W/O emulsion formulated with AA-1, while very stable, was characterised by comparatively very large water droplets, indicative of a complex multiple water-in-oil-in-water (W/O/W) emulsion microstructure. AA-2 forms stable emulsion with small droplets of water dispersed in the oil phase. Our results provide insight into a wide range of potential impacts of AA addition on an industrial crude oil pipeline, in which AA-1 resulted in a complex W/O/W multiple emulsion, AA-2 behaved as an emulsifier and AA-3 behaved as a demulsifier.

IMPORTANCE: Surgical treatment comparisons in rare diseases are difficult secondary to the geographic distribution of patients. Fortunately, emerging technologies offer promise to reduce these barriers for research. OBJECTIVE: To prospectively compare the outcomes of the 3 most common surgical approaches for idiopathic subglottic stenosis (iSGS), a rare airway disease. DESIGN, SETTING, AND PARTICIPANTS: In this international, prospective, 3-year multicenter cohort study, 810 patients with untreated, newly diagnosed, or previously treated iSGS were enrolled after undergoing a surgical procedure (endoscopic dilation [ED], endoscopic resection with adjuvant medical therapy [ERMT], or cricotracheal resection [CTR]). Patients were recruited from clinician practices in the North American Airway Collaborative and an online iSGS community on Facebook. MAIN OUTCOMES AND MEASURES: The primary end point was days from initial surgical procedure to recurrent surgical procedure. Secondary end points included quality of life using the Clinical COPD (chronic obstructive pulmonary disease) Questionnaire (CCQ), Voice Handicap Index-10 (VHI-10), Eating Assessment Test-10 (EAT-10), the 12-Item Short-Form Version 2 (SF-12v2), and postoperative complications. RESULTS: Of 810 patients in this cohort, 798 (98.5%) were female and 787 (97.2%) were white, with a median age of 50 years (interquartile range, 43-58 years). Index surgical procedures were ED (n = 603; 74.4%), ERMT (n = 121; 14.9%), and CTR (n = 86; 10.6%). Overall, 185 patients (22.8%) had a recurrent surgical procedure during the 3-year study, but recurrence differed by modality (CTR, 1 patient [1.2%]; ERMT, 15 [12.4%]; and ED, 169 [28.0%]). Weighted, propensity score–matched, Cox proportional hazards regression models showed ED was inferior to ERMT (hazard ratio [HR], 3.16; 95% CI, 1.8-5.5). Among successfully treated patients without recurrence, those treated with CTR had the best CCQ (0.75 points) and SF-12v2 (54 points) scores and worst VHI-10 score (13 points) 360 days after enrollment as well as the greatest perioperative risk. CONCLUSIONS AND RELEVANCE: In this cohort study of 810 patients with iSGS, endoscopic dilation, the most popular surgical approach for iSGS, was associated with a higher recurrence rate compared with other procedures. Cricotracheal resection offered the most durable results but showed the greatest perioperative risk and the worst long-term voice outcomes. Endoscopic resection with medical therapy was associated with better disease control compared with ED and had minimal association with vocal function. These results may be used to inform individual patient treatment decision-making.

Injecting carbon dioxide into geological formations for long‐term storage is considered integral to reducing greenhouse gas emissions. Residual trapping of CO2is a primary storage mechanism, whereby CO2ganglia are trapped in the pore space by capillary forces. Experimental knowledge of residual trapping processes in rocks is critical to the development of safe storage strategies. Here we present a quantitative low field 1H nuclear magnetic resonance (NMR) core flooding study of CO2residual trapping in three different sandstones. It was found that transverse relaxation (T2) measurements were sensitive to the dissolution of paramagnetic ions from rock matrix minerals after exposure to carbonic acid; this response was observed on time scales relevant to core flooding experiments (i.e., minutes to hours). Subsequently, a brine aging protocol was designed and implemented to minimize this chemical effect, and hence, by applying the well‐known T2‐pore size relationship, changes in T2time distributions during core flooding could be related to displacement of brine from pores of different sizes. Comparison of T2distributions for partially CO2/brine‐saturated cores to previously published data for N2/H2O systems shows an increased displacement of brine from small pores by CO2. Furthermore, results from cyclical brine/CO2injections showed an increase in the total volume of residually trapped CO2and an increase in trapping efficiency; compared to the results observed for N2/H2O, however, the improvement in trapping efficiency with cyclic injection was less pronounced. Potential causes for the observed differences are discussed in the context of effective N2and CO2wetting. NMR T2relaxation enhancement from paramagnetic ion dissolution from rock cores exposed to carbonic acid was measuredCyclical brine/CO2injection increases trapped CO2volumes and trapping efficiencyDifferences in the drainage of different pore size for CO2/brine and N2/water flooding suggest differences in wettability

Dielectric measurements of reservoir rocks are used to estimate important petro‐physical properties such as water‐filled porosity and pore surface textures. However, complex dielectric polarization processes that occur in rocks are strongly dependent on frequency, making physically meaningful interpretation of broadband dielectric data difficult. At high frequency (> 10 MHz) dielectric permittivity primarily relates to the volume fractions of constituents (i.e., saturation, minerals), while at lower frequency (< 10 MHz), interpretation is complicated by interfacial polarization, electro‐diffusion phenomena, and ohmic conduction. The ability to de‐convolve these electrical processes is critical for interpreting petro‐physical properties from broadband dielectric data. Here we demonstrate the application of Tikhonov regularization methods to compute dielectric relaxation time distributions from broadband (40 Hz to 110 MHz) dielectric data for ten shale core samples at varying partial saturation. Furthermore, via the Kramers‐Kronig relation, the contribution from in‐phase conduction currents to the imaginary component of the dielectric response was quantified. The evolution of dielectric polarization processes with increasing moisture content was analyzed directly from changes in relaxation time distributions. It was found that the dominant polarization mechanism, up to a critical partial saturation, occurred as surface polarization within the electrical double layer. Above this critical partial saturation, electro‐diffusion mechanisms acting between the Stern and diffuse layers resulted in a large low frequency response. This work provides valuable insight into dielectric polarization mechanisms in shales and demonstrates such measurements are sensitive to electrical double layer properties and electro‐diffusion length scales that are potentially relevant to characterizing pore‐scale properties in shales. Tikhonov regularization methods were applied to compute dielectric relaxation time distributions from broadband dielectric dataDielectric relaxation time distributions for a range of shale samples were determined as a function of water saturationAbove a critical partial saturation, electro‐diffusion mechanisms dominated the low frequency dielectric permittivity

A study on the occurrence of dysphonia among elderly individuals, and its impact on their quality of life, is presented.

Asphaltenes are widely associated with the unwanted stability of water-in-crude oil (w/o) emulsions due to their inhibitory effect on water droplet coalescence. Here, we seek to prove that certain crude oil resins that can bind with asphaltenes, hereafter referred to as binding resins, are capable of solvating these asphaltenes such that the w/o emulsion destabilizes. W/o emulsions were formed using a variety of crude oils as well as model oils with varying amounts of resins and asphaltenes. A modified SARA fractionation technique was adopted to extract the required resins and asphaltenes. Emulsion stability was tracked over time both visually and via the use of pulsed field gradient nuclear magnetic resonance to quantify the emulsions’ water droplet size distributions. It was conclusively found that the binding resins significantly improved the demulsification rate of the emulsions formed using both crude oil and model oils. In the case of the model oils, this influence could only be attributed to the removal of the asphaltenes from the droplet surfaces by the binding resins; the effect was shown to be partially independent of the source of the binding resin. The use of this oil fraction subclass for emulsion destabilization shows great promise as a new flow assurance strategy by substituting costly synthetic chemical emulsion destabilizers with naturally occurring resins.

IMPORTANCE: Diagnostic flexible laryngoscopy (DFL) is the second-most reimbursed procedure by Medicare in otolaryngology. However, the economic trends of this procedure on a population level are unknown. OBJECTIVE: To describe national- and state-level DFL and videolaryngostroboscopy (VLS) utilization and payment trends from 2000 to 2016 in the Medicare population. DESIGN, SETTING, AND PARTICIPANTS: This population-based, cross-sectional study of all Medicare beneficiaries from 2000 through 2016 found that at the national level the total absolute number of DFLs performed in the US Medicare population increased by 87% from 344 183 to 645 172 services, whereas total absolute payments for DFLs made by Medicare concurrently increased by 41% from $38 720 243 to $54 499 071. Rates of DLS and VLS categorized as Current Procedural Terminology (CPT) code 31575 and 31579, respectively. Analysis was carried out between November 18, 2018 and December 18, 2018. EXPOSURES: Diagnostic flexible laryngoscopy and VLS. MAIN OUTCOMES AND MEASURES: The DFL and VLS utilization rates, payments, and reimbursement rate trends were analyzed by year and state. Utilization was assessed for physician characteristics, including specialty and credentials. RESULTS: Nationally from 2000 to 2016 in the Medicare population, DFL utilization per Medicare enrollee increased 30% from 0.0087 to 0.0110 and payment per enrollee decreased 2% from $0.98 to $0.96, whereas VLS utilization and payment per enrollee both increased at least 300% during the same time period, with VLS procedure per enrollee and payment per enrollee increasing by 382% from 0.00028 to 0.0013 and 301% from $0.05 to $0.22, respectively. There was a weak correlation between reimbursement and utilization per enrollee for both DFL (r = 0.23; 95% CI, 0.12-0.34) and VLS (r = 0.26; 95% CI, 0.14-0.37) performed from 2012 to 2016. In 2016, the mean (SD) payment per DFL was $85.14 ($7.95), ranging from $65.45 in Puerto Rico to $104.82 in Washington, DC, a 1.6-fold difference. For VLS, there was a 2-fold difference between the lowest-reimbursing state, Maine ($92.20) and the highest, New York ($182.96). All US dollar values were uniformly adjusted for inflation to 2018 dollar values. Most DFLs in 2016 were performed by otolaryngologists (93.6%). CONCLUSIONS AND RELEVANCE: The DFL utilization rates remained stable compared with VLS in the Medicare population from 2000 to 2016. There was a decrease in both DFL and VLS payments per procedure in the same time period and also weak correlations between reimbursement and utilization. Practice patterns and reimbursement varied geographically across the United States, though VLS exhibited significantly higher variation than DFL at the state level.

The production of water during crude oil extraction may result in the formation of stable water-in-oil emulsions. Such emulsions are problematic for a variety of reasons; for example, they increase the fluid viscosity and hence the pumping costs. Previously, Ling; [NMR Studies of the Effect of CO2on Oilfield Emulsion Stability. Energy Fuels2016, 307, 5555–5562] have shown that treating these water-in-crude oil emulsions with subcritical CO2at 50 bar can lead to their breakage. These measurements utilized benchtop NMR pulsed field gradient (PFG) techniques to monitor the evolution in the emulsion droplet size distribution, which is a precursor to emulsion breakage. Experimental limitations meant, however, that the measurements were performed only following depressurization of the applied CO2and as such were unable to directly distinguish between two potential mechanisms for emulsion breakage as proposed in the literature: (i) CO2bubble formation within the water droplets upon depressurization or (ii) the removal of surface-adsorbed asphaltenes. Here, we develop a new apparatus and perform the required emulsion droplet sizing measurements using NMR PFG techniques with the sample under pressure during CO2treatment. A distinct growth in the droplet size was observed during the treatment, which is consistent with mechanism (ii); however, further growth was observed following depressurization and shown to be consistent with mechanism (i); thus, both are relevant. The efficacy of the treatment was then further assessed for the case of NaCl addition to the aqueous phase.

Presents a speech by Michael Johns, assistant editor of "Policy Review," delivered at the Heritage Foundation in Washington, D.C. on September 17, 1986. Observations during his visit to the front lines in January 1984; Fallacy surrounding the debate to fund the Nicaraguan resistance; Criticisms on the Contadora treaty.

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Health care is one of the few industries in which the consumer (in this case, the patient) seldom pays for the full cost of the service or product. This dynamic [...]