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We hereby present a rare case of laryngeal zoster presenting with unilateral odynophagia and hemifacial pain in an immunocompetent host. Visualization of the characteristic vesicles is challenging given their short-lived and at times delayed appearance; thus, laryngeal zoster may be a largely unrecognized cause of laryngitis and cranial neuropathies. Heightened awareness may improve prompt diagnosis, referral and initiation of antiviral therapy, while guiding patient counselling on the associated long-term sequelae such as voice and swallowing impairments, and post-herpetic neuralgia., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Metastatic renal cell carcinoma to the thyroid is a rare yet aggressive histopathologic diagnosis, which may often be omitted from the initial clinical differential. This is in part due to the long latency period between the initial renal primary and appearance of metastatic disease, coupled with the diagnostic limitations of fine-needle aspiration biopsies. We herein present an interesting case of a metastatic clear-cell renal-cell carcinoma mimicking an aggressive primary thyroid neoplasm, 10 years after a nephrectomy for a renal primary, highlighting key diagnostic and management considerations., Competing Interests: Declaration of conflicting interestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Background: Patients with oropharyngeal squamous cell carcinoma (OPSCC) treated with radiation-based therapy suffer from short- and long-term toxicities that affect quality of life (QOL). Transoral robotic surgery (TORS) has an established role in the management of early OPSCC but adjuvant treatment is often indicated postoperatively due to the high incidence of nodal metastasis associated with advanced human papillomavirus (HPV)-related OPSCC. To overcome the need for adjuvant radiation therapy (RT), neoadjuvant chemotherapy followed by TORS and neck dissection (ND) is proposed. This study aimed to assess if QOL in HPV-associated OPSCC receiving neoadjuvant chemotherapy followed by TORS and ND returns to baseline within 12 months of completing treatment., Methods: A 12 month longitudinal study was carried out at McGill University Health Centre in Montreal, Canada, among a convenience sample of patients with American Joint Committee on Cancer Seventh Edition stage III and IVa HPV-related OPSCC who were treated with neoadjuvant chemotherapy followed by TORS and ND. QOL data were obtained pretreatment and at 1, 3, 6, and 12 months following treatment completion using the European Organisation for Research and Treatment of Cancer Core and Head and Neck extension modules. Paired t tests and mixed models for repeated measures analysis were used to assess changes in QOL from baseline to 12 months postoperatively and over time, respectively., Results: Nineteen of 23 patients (median age 58 years) who received the study treatment fulfilled the eligibility criteria. OPSCC subsites were palatine tonsil (n = 12) and base of tongue (n = 7). All 19 patients were treated per protocol and none required adjuvant RT as per pathology review and protocol requirements at a postoperative multidisciplinary team tumor board discussion. No significant differences were found when comparing 12 month QOL follow-up scores to pretreatment scores in measures that would likely be affected by RT [eg, swallowing ( P  = .7), social eating ( P  = .8), xerostomia ( P  = .9)]., Conclusion: In HPV-related OPSCC, neoadjuvant chemotherapy followed by TORS and ND as definitive treatment is associated with excellent QOL outcomes. Postoperative QOL scores returned to baseline by 3 months and were maintained for all measures, indicating a return to normal function., Competing Interests: Declaration of Conflicting InterestsThe authors declare that they have no competing interests.

Importance: Efforts are underway to deintensified treatment protocols for patients with human papillomavirus virus-associated oropharyngeal squamous cell carcinoma (HPV-OPSCC) to achieve similar excellent oncologic outcomes while reducing treatment-related adverse effects. Transoral robotic surgery (TORS) as primary treatment often requires adjuvant therapy due to the high incidence of nodal metastasis. Treatment with neoadjuvant chemotherapy followed by TORS and neck dissection (NECTORS), reserving radiation therapy for salvage, yields excellent oncologic outcomes., Objective: To assess patient-reported quality of life (QOL) and functional outcomes among patients with HPV-OPSCC who undergo NECTORS., Design, Settings, and Participants: This was a multicenter prospective cohort study of patients with HPV-OPSCC treated with the NECTORS protocol in 2017 to 2022. Consecutive patients with stage III or IVa HPV-OPSCC treated with NECTORS in 2017 to 2022 who had completed the primary QOL questionnaire at baseline and at least once during the 24-month follow-up period were included. Ninety-four patients were eligible, and 67 were included in the analyses., Outcome Measures: QOL questionnaires at baseline, and at month 1, 3, 6, 12, 18, and 24 posttreatment. Global score on the 30-item European Organization for Research and Treatment of Cancer Core quality of life questionnaire (EORTC QLQ-C30) was the primary outcome; the head and neck extension module (EORTC QLQ-HN35); the MD Anderson Dysphagia Inventory for dysphagia-related QOL; and the Decision Regret Scale were also used. Paired t tests assessed change between the baseline and 12- or 24-month patient-reported outcomes., Results: Among the study population of 67 patients (median [range] age, 63 [58-67] years; 54 [80.6%] male) with HPV-OPSCC, the most frequent cancer subsites were palatine tonsil (41 [61%]) and base of tongue (26 [39%]); none required adjuvant RT. Global QOL at 24 months improved compared with baseline (mean difference, 9.49; 95% CI, 2.45 to 16.53). All EORTC QLQ-C30 functional scores returned to baseline or improved within 3 to 6 months posttreatment and remained stable at 24 months. EORTC QLQ-HN35 symptom scale scores improved or were stable at 24 months. The MD Anderson Dysphagia Inventory scores demonstrated no significant difference between baseline and month 12 for global scores (mean difference, 6.15; 95% CI, -4.18 to 16.49) and composite scores (mean difference, 2.73; 95% CI, -1.62 to 7.09). Median (range) score on the Decision Regret Scale was 5 of 100 (0-30), representing mild overall regret., Conclusion and Relevance: The findings of this multicenter cohort study indicate that use of the NECTORS protocol is associated with excellent QOL outcomes. QOL measures returned to baseline levels or were better than baseline, which represents positive outcomes for patients with HPV-OPSCC who undergo this treatment regimen.

The incidence of all head and neck malignancies is rising worldwide, with carcinoma of the larynx constituting approximately 1% of all cancers. Early glottic cancer responds quite favorably to surgical intervention due to its early presentation, coupled with the low rate of regional and distant metastases. This article focuses on various approaches to the surgical treatment of early glottic cancer. Details include the clinical and radiological evaluation of laryngeal cancer, the goals of treatment, current surgical options for early disease, approach to surgical resection margins and management of nodal disease, and complications associated with each treatment modality., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Importance: Obesity has traditionally been described as a relative contraindication to percutaneous dilatational tracheostomy (PDT). Increased familiarity with the technique and use of bronchoscopy or real-time ultrasonography to enhance visualization have led many practitioners to expand the indication for PDT to patients historically deemed to have high risk of perioperative complications., Objective: To assess the reported complication rate of PDT in critically ill adults with obesity and compare it with that of open surgical tracheostomies (OSTs) in this patient population and with that of PDT in their counterparts without obesity., Data Sources: In this systematic review and meta-analysis, Ovid MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials were searched from January 1, 2000, to March 1, 2022. Key terms related to percutaneous tracheostomy and obesity were included., Study Selection: Original investigations of critically ill adult patients (age ≥18 years) with obesity who underwent PDT that reported at least 1 complication of interest were included. Case reports or series with fewer than 5 patients were excluded, as were studies in a language other than English or French., Data Extraction and Synthesis: Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) and Meta-analysis of Observational Studies in Epidemiology (MOOSE) were used, with independent extraction by multiple observers. Frequencies were reported for all dichotomous variables. Relative risks for complications were calculated using both fixed-effects and random-effects models in the meta-analysis., Main Outcomes and Measures: Main outcomes included mortality directly associated with the procedure, conversion to OST, and complications associated with the procedure (subclassified into life-threatening or non-life-threatening adverse events)., Results: Eighteen studies were included in the systematic review, comprising 1355 patients with obesity who underwent PDT. The PDT-related complication rate was 16.6% among patients with obesity overall (791 patients, 17 studies), most of which were non-life-threatening. Only 0.6% of cases (8 of 1314 patients, 17 studies) were aborted or converted to an OST. A meta-analysis of 12 studies (N = 4212; 1078 with obesity and 3134 without obesity) showed that patients with obesity had a higher rate of complications associated with PDT compared with their counterparts without obesity (risk ratio, 1.78; 95% CI, 1.38-2.28). A single study compared PDT with OST directly for critically ill adults with obesity; thus, the intended meta-analysis could not be performed in this subgroup., Conclusions and Relevance: The findings suggest that the rate of complications of PDT is low in critically ill individuals with obesity, although the risk of complications may be higher than in individuals without obesity.

Objectives: To conduct a scoping review of the literature on psychological interventions directed to identify primary prevention strategies for depression among adult head and neck cancer (HNC) patients., Methods: Systematic searches were conducted following Preferred Reporting Items for Systematic Reviews and Meta-Analysis Extension for Scoping Review including relevant studies within the PubMed, PsycINFO, and EMBASE databases. Two authors independently screened the searches and reviewed the included articles according to the predetermined eligibility criteria based on the PICOS format. Studies included subjects with previous or current diagnosis of depression were excluded. The risk of bias assessment of these trials was conducted following the Cochrane tool for assessing the risk of bias in randomized trials. The search was repeated prior to submission to ensure all current articles meeting criteria were included., Results: The search yielded 875 studies. The title and abstract screen, followed by the review of full texts identified five articles that met inclusion criteria. Four were randomized controlled trials (RCT) and the fifth was a non-randomized but controlled study. Different psychosocial interventions were used, including psycho-educational interventions, psychosocial counseling, and pharmacotherapy. All studies established the diagnosis of depression or screened for the diagnosis using standardized psychiatric assessment tools, either Diagnostic and Statistical Manual of Mental Disorders criteria or validated patient reported outcome measures. The average follow-up periods after intervention was 9.8 months. There was a significant decrease in the incidence of depression or depressive symptoms favoring the intervention group in three out of the five studies that were included., Conclusion: Psychological interventions identified thus far studying primary prevention of depression in HNC patients show promising results. However, the paucity of data and heterogeneity of the interventions challenges the ability to compare the prevention modalities and outcomes. Future well-designed RCTs with large sample sizes are recommended to better conclude a result of effectiveness., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: Oropharyngeal squamous cell carcinoma (OPSCC) patients are burdened by the effect of the disease process and treatment toxicities on organs important in everyday activities, such as breathing, speaking, eating, and drinking. There is a rise in OPSCC due to human papilloma virus (HPV)-associated OPSCC, affecting younger and healthier patients and with a better overall prognosis. Emphasis must be shared between oncologic outcomes and the effects on quality of life. While there have been efforts to study global and physical quality of life, the impact on psychosocial quality of life has not yet been specifically reviewed. Methods: A scoping review methodology was employed to explore the emotional, social, and mental quality of life in OPSCC patients and determine the impact of HPV status or treatment modalities. Results: Eighty-seven full-text articles were evaluated for eligibility. Fifteen articles met final inclusion criteria. The majority of the studies were conducted in the United States (n = 10) and study methodology was divided between cross-sectional (n = 6), prospective (n = 5), and retrospective studies (n = 4). Four psychosocial quality of life themes were explored: the impact on mental health and emotional wellbeing, social wellbeing and function, stress, and relationship and sexual behavior. Eighteen different patient-reported outcome measures were used, including both general head and neck oncology questionnaires and symptom-specific surveys. Conclusion: There is a paucity of research regarding the effect of OPSCC on patients' psychosocial quality of life. Learning more about this component of quality of life can guide outreach programs and multidisciplinary involvement in improving patient care.

Competing Interests: Declaration of conflicting interestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Significance Statement: We present the rare case of a nasal lobular capillary hemangioma with bony erosion atypically localized to the left piriform aperture. This fast-growing lesion caused both physical and emotional distress due to recurrent epistaxis and prominent esthetic deformity evidenced by a large nasal growth. While the final diagnosis was benign, the clinical and radiological findings caused concern. This case serves as a reminder that prompt referral, work-up, and diagnosis are essential to optimize patient care., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Objectives/hypothesis: Quantity and quality of Otolaryngology-Head and Neck Surgery (OTL-HNS) research are increasing, yet patterns within Pediatric OTL-HNS publications are unknown. This study examines trends in the level of evidence of pediatric OTL-HNS articles over a 20-year period to quantify the growth and characterize contributing factors., Study Design: Review article., Methods: A retrospective review was conducted on 12 peer-reviewed OTL-HNS journals at three time-points: 1996, 2006, and 2016. Pediatric-specific OTL-HNS journals were selected; all were among the top 10 highest impact factor journals, with one pediatric-specific and one Canadian journal. Publication details, author characteristics, and study focus were collected. Papers were classified based on the Oxford Centre for Evidence-Based Medicine Levels of Evidence by two independent reviewers., Results: Of the 1,733 articles reviewed, 727 met inclusion criteria. A greater absolute number of pediatric OTL-HNS articles were published over the years studied: from 95 in 1996 to 359 in 2016 (P < .001). As well, the absolute number of high-quality studies has increased over the study period, from 28 articles in 1996 to 100 articles in 2016. However, the relative percentage of high-quality papers remained stable between 27.9% and 32.2% with an average of 29.7% (P = .89). Higher impact factor journals did not tend to publish higher-quality pediatric OTL-HNS articles (P = .48)., Conclusions: Over the past 20 years, there is no appreciable improvement in the proportion of high-quality publications in pediatric OTL-HNS; however, there is an overall greater number of high-quality papers within OTL-HNS literature. These findings likely relate to challenges of research within pediatric surgical specialties., Level of Evidence: NA Laryngoscope, 132:1869-1876, 2022., (© 2021 The American Laryngological, Rhinological and Otological Society, Inc.)

Prostate cancer metastases involving the orbit and/or paranasal sinuses represent a rare oncological presentation. Patients can have a myriad of symptoms such as proptosis, periorbital swelling, blurry vision, rhinorrhea, epistaxis, anosmia, or others depending on the structures involved. The differential diagnosis of paranasal sinus masses on imaging studies is broad and can include inflammatory, congenital, or neoplastic masses; leading to the requirement of biopsy for definitive diagnosis. Tissue sample is usually obtained via an endoscopic approach. The prognosis of such a presentation is not well described in the literature, but it is usually guarded due to the advanced stage of the disease and generally a poorly differentiated primary tumor. Treatments usually aim to reduce the burden of disease and debulk the tumor mass for palliative purposes. We present a case of a 71-year-old male presenting with unilateral proptosis and periorbital swelling secondary to prostatic metastasis., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

The prevalence of oropharyngeal squamous cell carcinoma has been increasing in North America due to human papillomavirus-associated disease. It is molecularly distinct and differs from other head and neck cancers due to the young population and high survival rate. The treatment regimens currently in place cause significant long-term toxicities. Studies have transitioned from mortality-based outcomes to patient-reported outcomes assessing quality of life. There are many completed and ongoing trials investigating alternative therapy regimens or de-escalation strategies to minimize the negative secondary effects while maintaining overall survival and disease-free survival. The goal of this review is to discuss the most recent advancements within the field while summarizing and reviewing the available evidence.

Background: While some studies suggest that the BRAF V600E mutation correlates with a high-risk phenotype in papillary thyroid microcarcinoma (PTMC), more evidence is necessary before this mutation can be used to help guide decision making in the management of small thyroid nodules. This study investigated whether BRAF V600E mutation is associated with aggressive features in PTMC (≤ 1 cm) and small PTC (1-1.5 cm)., Methods: Retrospective chart review was performed on 121 patient cases. Patients who underwent thyroid surgery for PTMC (≤ 1 cm) or small PTC (1-1.5 cm) were included if molecular testing was done for BRAF V600E mutation. Two study groups were created based on tumour size: PTMC (n = 55) and small PTC (n = 66). The groups were analysed for the presence of a BRAF V600E mutation and aggressive features, including macroscopic extrathyroidal extension (ETE), lymph node metastasis (LNM), and high-risk histological features (tall cell, columnar cell, hobnail, solid/trabecular, and diffuse sclerosing). The Fischer exact test was used to calculate statistical significance., Results: BRAF V600E mutations were detected in 43.6% of PTMC and 42.4% of small PTC. Of the mutated PTMC nodules, 54.1% demonstrated aggressive characteristics as compared to 19.4% of the non-mutated PTMCs (p = 0.010). Of the mutated small PTC tumours, 82.1% had aggressive features. In contrast, 28.9% of the non-mutated small PTCs showed aggressive features (p < 0.001)., Conclusions: Our findings demonstrate an association between a BRAF V600E mutation and aggressive features in PTMC (≤ 1 cm) and small PTC (1-1.5 cm). Therefore, determining the molecular status of these thyroid nodules for the presence of BRAF V600E can help guide patient management., (© 2021. The Author(s).)

Objective: The purpose of this study was to evaluate the quality of evidence of rhinology and rhinologic skull base surgery (RSBS) research and its evolution over the past decade., Study Design: Review article., Setting: We reviewed articles from 2007 to 2019 in 4 leading peer-reviewed otolaryngology journals and 3 rhinology-specific journals., Methods: The articles were reviewed and levels of evidence were assigned using the Oxford Centre for Evidence-Based Medicine 2011 guidelines. High quality was defined as level of evidence 1 or 2., Results: In total, 1835 articles were reviewed in this study spanning a 13-year period. Overall, the absolute number of RSBS publications increased significantly 22.6% per year, from 108 articles in 2007 to 481 in 2019 ( P < .001; 95% CI, 7.9-37.2). In 2007, only 13 articles, or 15%, were high quality, and this grew to 146 articles, or 39%, in 2019. A 14.0% per year exponential increase in the number of high-quality publications was found to be statistically significant ( P < .001; 95% CI, 7.2, 20.7). Overall, high-quality publications represented just 25.8% of RSBS articles overall. There was no significant difference in quality between rhinology-specific journals and general otolaryngology journals (χ 2 = 3.1, P = .077)., Conclusion: The number of overall publications and of high-quality RSBS publications has significantly increased over the past decade. However, the proportion of high-quality studies continues to represent a minority of total RSBS research.

Background: Opioid-prescribing patterns have been implicated as a contributing factor to the opioid epidemic, yet few evidence-based guidelines exist to assist health-care providers in assessing and possibly modifying their prescribing practices., Methods: Five orthopaedic hand surgeons at a level-I trauma center developed a postoperative prescribing guideline for 25 common hand and upper-extremity outpatient procedures, which were delineated into 5 tiers. Postoperative opioid prescriptions in a 3-month period after implementation of the protocol were compared with those from a 3-month period before implementation of the protocol., Results: There were 231 patients in the pre-implementation group and 287 patients in the post-implementation group. Each individual opioid protocol tier showed a significant decrease in the mean morphine milligram equivalents (MME) prescribed, ranging from a minimum decrease of 97.8% to a maximum decrease of 176.0%. After implementation, adherence to protocol was achieved in 55.1% of patients; the MME amounts prescribed were below protocol for 28.6% and above for 16.4%. The number of additional opioid prescriptions in the 1-month postoperative period was significantly less in the post-implementation group than in the pre-implementation group (p < 0.001). The total number of pills prescribed was reduced by a theoretical equivalent of over three thousand 5-mg oxycodone pills for the 287 patients in the 3-month period., Conclusions: By utilizing a simple consensus protocol, we have demonstrated success diminishing the number of opioids prescribed without leading to an increase in the number of secondary prescriptions written by our providers. These findings are encouraging and suggest that fewer opioids were left in the possession of patients, leaving fewer pills vulnerable to misuse, abuse, and diversion.

Businesses may be missing opportunities to account for ecosystem services in their decisions, because they do not have methods to quantify and value ecosystem services. We developed a method to quantify and value coastal protection and other ecosystem services in the context of a cost-benefit analysis of hurricane risk mitigation options for a business. We first analyze linked biophysical and economic models to examine the potential protection provided by marshes. We then applied this method to The Dow Chemical Company's Freeport, Texas facility to evaluate natural (marshes), built (levee), and hybrid (marshes and a levee designed for marshes) defenses against a 100-y hurricane. Model analysis shows that future sea-level rise decreases marsh area, increases flood heights, and increases the required levee height (12%) and cost (8%). In this context, marshes do not provide sufficient protection to the facility, located 12 km inland, to warrant a change in levee design for a 100-y hurricane. Marshes do provide some protection near shore and under smaller storm conditions, which may help maintain the coastline and levee performance in the face of sea-level rise. In sum, the net present value to the business of built defenses ($217 million [2010 US$]) is greater than natural defenses ($15 million [2010 US$]) and similar to the hybrid defense scenario ($229 million [2010 US$]). Examination of a sample of public benefits from the marshes shows they provide at least $117 million (2010 US$) in coastal protection, recreational value, and C sequestration to the public, while supporting 12 fisheries and more than 300 wildlife species. This study provides information on where natural defenses may be effective and a replicable approach that businesses can use to incorporate private, as well as public, ecosystem service values into hurricane risk management at other sites., (© 2015 The Authors. Integrated Environmental Assessment and Management Published by Wiley Periodicals, Inc. on behalf of SETAC.)

An improved Raman gain spectrometer for flame measurements of gas temperature and species concentrations is described. This instrument uses a multiple-pass optical cell to enhance the incident light intensity in the measurement volume. The Raman signal is 83 times larger than from a single pass, and the Raman signal-to-noise ratio (SNR) in room-temperature air of 153 is an improvement over that from a single-pass cell by a factor of 9.3 when the cell is operated with 100 passes and the signal is integrated over 20 laser shots. The SNR improvement with the multipass cell is even higher for flame measurements at atmospheric pressure, because detector readout noise is more significant for single-pass measurements when the gas density is lower. Raman scattering is collected and dispersed in a spectrograph with a transmission grating and recorded with a fast gated CCD array detector to help eliminate flame interferences. The instrument is used to record spontaneous Raman spectra from N(2), CO(2), O(2), and CO in a methane-air flame. Curve fits of the recorded Raman spectra to detailed simulations of nitrogen spectra are used to determine the flame temperature from the shapes of the spectral signatures and from the ratio of the total intensities of the Stokes and anti-Stokes signals. The temperatures measured are in good agreement with radiation-corrected thermocouple measurements for a range of equivalence ratios., (© 2011 Optical Society of America)

Multiple-pass optical cells with dense spot patterns are useful for many applications, especially when the cell volume must be minimized relative to the optical path length. Present methods to achieve these dense patterns require expensive, highly precise astigmatic mirrors and complex alignment procedures. This work describes a new, simpler, and less demanding mirror system, comprising either a pair of cylindrical mirrors or one cylindrical and one spherical mirror.

Object: Diffuse axonal injury (DAI) is a major complication of traumatic brain injury (TBI) that leads to functional and psychological deficits. Although DAI is frequently underdiagnosed by conventional imaging modalities, it can be demonstrated using diffusion tensor imaging. The aim of this study was to assess the presence and extent of DAI in patients with mild TBI., Methods: Forty-six patients with mild TBI and 29 healthy volunteers underwent a magnetic resonance (MR) imaging protocol including: dual-spin echo, fluid-attenuated inversion recovery, T2-weighted gradient echo, and diffusion tensor imaging sequences. In 20 of the patients, MR imaging was performed at a mean of 4.05 days after injury. In the remaining 26, MR imaging was performed at a mean of 5.7 years after injury. In each case, mean diffusivity and fractional anisotropy were measured using both whole-brain histograms and regions of interest analysis. No differences in any of the histogram-derived measures were found between patients and control volunteers. Compared with controls, a significant reduction of fractional anisotropy was observed in patients' corpus callosum, internal capsule, and centrum semiovale, and there were significant increases of mean diffusivity in the corpus callosum and internal capsule. Neither histogram-derived nor regional diffusion tensor imaging metrics differed between the two groups., Conclusions: Although mean diffusivity and fractional anisotropy abnormalities in these patients with TBI were too subtle to be detected with the whole-brain histogram analysis, they are present in brain areas that are frequent sites of DAI. Because diffusion tensor imaging changes are present at both early and late time points following injury, they may represent an early indicator and a prognostic measure of subsequent brain damage.

Objective: Our purpose is to examine the effect of different classes of anxiolytics on cognitive flexibility., Background: Situational stressors and anxiety impede performance on "creativity" tests requiring cognitive flexibility. Noradrenergic agents have been shown to modulate cognitive flexibility as assessed by performance on anagrams. To determine whether these findings on noradrenergic modulation of cognitive flexibility are specific to the noradrenergic system or are a nonspecific anxiety effect, we compared the effects of propranolol, lorazepam, and placebo on the anagram task., Methods: Subjects attended 3 test sessions. Prior to each session, subjects were given 1 of the 3 drugs. As in previous research, the natural log of the solution latency of each test item was summed for each test session and compared across drug conditions., Results: For subjects able to solve the anagrams, solution times after propranolol, but not lorazepam, were significantly lower than after placebo., Conclusions: Therefore, this suggests that the phenomenon of noradrenergic modulation of cognitive flexibility does not result from a nonspecific anxiolytic effect, but rather is specific to the noradrenergic system.

Water vapor is measured by use of a near-infrared diode laser and wavelength-modulation absorption spectroscopy. Humidity levels as low as 5 nmol/mol [1 nmol/mol = 1 ppb (1 ppb equals 1 part in 10(9))] of water vapor in air are measured with a sensitivity of better than 0.2 nmol/mol (3varsigma). The sensitivity, linearity, and stability of the technique are determined in experiments conducted at the National Institute of Standards and Technology, Gaithersburg, Maryland, by use of the low frost-point humidity generator over the range from 5 nmol/mol to 2.5 mumol/mol of water vapor in air. The pressure-broadening coefficients for water broadened by helium [0.0199(6) cm(-1) atm(-1) HWHM] and by hydrogen chloride [0.268(6) cm(-1) atm(-1) HWHM] are reported for the water line at 1392.5 nm.

Absolute concentrations of water vapor are measured in microgravity (µ-g), nonpremixed methane, and propane jet flames with diode-laser wavelength modulation spectroscopy. These experiments are performed in the 2.2-s µ-g drop facility at the NASA Lewis Research Center. Abel inversion methods are used to determine time-dependent radial profiles from eight line-of-sight projections across the flames. At all measured heights above the nozzle, water vapor spatial distributions in µ-g flames are much wider than their 1-g counterparts. Radial growth of the water signal continues throughout the drop, verifying earlier suggestions that a steady state is not reached during the duration of the test, despite a quasi-steady flame shape. Large amounts of water vapor are observed at larger radii, at odds with visual (video) observations and numerical predictions.

Effects of experimental exposure to O3 (0.33 ppm) or filtered air on regional lung function were assessed in nine healthy male subjects. Immediately after 2-h chamber exposures, regional ventilation and particle dosimetry were measured by gamma camera imaging. The vertical distributions of a radiolabeled gas (133Xe) and aerosol (3.5-microns-diam insoluble 99mTc-tagged Fe2O3 particles) were quantitated for upper, middle, and lower lung regions; distribution data were corrected for regional differences in lung volume and tissue attenuation. Indexes of mechanical function, inspiratory capacity, and mid-maximal expiratory flow rates were significantly reduced after O3, but functional residual capacity remained unchanged. Exposure to O3 significantly enhanced the fraction of respired aerosol retained by the lung and altered the distribution pattern of deposited aerosol by increasing particle deposition to the middle lung region (P < 0.05). Aerosol penetration indexes, i.e., ratio of particle deposition in central lung regions to that in peripheral lung regions, and particle retention 24 h postinhalation (an index of aerosol deposition within alveoli and slowly clearing bronchioles) indicated that particle filtration efficiency had increased for tracheobronchial and parenchymal lung regions. For seven of the nine subjects, regional ventilation after O3 was reduced by 14% to the lung base and enhanced by 8 and 6% to the upper and middle lung regions, respectively; these changes were significant (P < 0.02) compared with ventilation after filtered air.(ABSTRACT TRUNCATED AT 250 WORDS)

A variety of frequency-modulation methods for high-sensitivity absorption detection of gas-phase species has evolved in recent years. The distinctions among these methods are mostly semantic. The mathematical derivations for wavelength-modulation spectroscopy and one- and two-tone frequency-modulation spectroscopies are presented; a common terminology is used to permit a comprehensive comparison of predicted detection sensitivities. Applying this formalism, I compare the optimum detection sensitivities of these different methods for a typical laser system, using the same parameters. As long as residual amplitude modulation is minimized by proper adjustment of the detection phase angle, high-frequency wavelength modulation and one- and two-tone frequency-modulation methods all achieve approximately the same sensitivities. The choice among techniques is most strongly driven by the individual laser tuning characteristics, the absorption linewidth, and the detection bandwidth. It is shown that excess laser noise cannot always be excluded from consideration, even at megahertz detection frequencies. Also, detection at harmonics of the modulation or beat frequency may present certain advantages in minimizing residual amplitude-modulation noise.

Wavelength modulation spectroscopy (WMS) and one-tone and two-tone frequency modulation spectroscopy (FMS) are compared by measuring the minimum detectable absorbances achieved using a mid-IR lead-salt diode laser. The range of modulation and detection frequencies spans over 5 orders of magnitude. The best results, absorbances in the low-to-mid 10(-7) range in a 1-Hz bandwidth, are obtained by using high-frequency WMS (10-MHz detection frequency) and are limited by detector thermal noise. This sensitivity can provide species detection limits well below 1 part per billion for molecules with moderate line strengths if multiple-pass cells are used. High-frequency WMS is also tested by measuring the absorbance due to tropospheric N(2)O at 1243.795 cm(-1). WMS at frequencies < 100 kHz is limited by laser excess (1/f) noise. Both of the FMS methods, which require modulating the laser at frequencies >/= 150 MHz, give relatively poor results due to inefficient coupling of the modulation waveform to the laser current. The re ults obtained agree well with theory. We also discuss the sensitivity limitations due to interference fringes from unintentional étalons and the effectiveness of étalon reduction schemes.

We used a single-mode Pb-salt diode laser to quantify in situ the amount of ammonia generated during pyrolysis of pulverized coal in an entrained-flow reactor at 1225 K. The combination of wavelength modulation spectroscopy, a Herriott style multiple pass cell, rapid wavelength scanning (to eliminate noise due to turbulence and vibration) and a novel etalon fringe suppression technique provided a minimum detectable absorbance of 2 x 10(-6) (SNR = 1, 1-Hz bandwidth) corresponding to 0.04-ppm ammonia at 1225 K. This is a 4-order-of-magnitude improvement over CO(2) laser based ammonia detectors and is approximately 2000 times more sensitive than electrochemical detection methods (for equal integration times).

Hydrogen chloride gas is measured by absorption in the second overtone band near 1.2microm using an InGaAsP diode laser. The strength and air-broadening coefficient of the H(35)Cl P(3) line are measured. The line strength is ~18% higher than the previous grating spectrometer measurement and suggests that the commonly used experimental value for the 3 ?0 HCl vibrational moment may be low. High-frequency two-tone FM detection is also used in this study to measure trace concentrations of HCl. Using a multimode laser, the sensitivity limit is 3-parts per million HCl in air at 50 Torr, corresponding to a minimum detectable fractional absorption (multimode) of 4 x 10(-6). Optimization of the detection method should permit real-time measurement of concentrations below 0.1 ppm. The low cost and convenient operating characteristics of InGaAsP diode lasers make them attractive for many applications in high-resolution near-IR spectroscopy and trace species detection.

Two-tone optical heterodyne detection using single mode buried double heterostructure lead-salt diode lasers is studied. Residual amplitude modulation with these lasers is found to be substantially smaller than has been noted in previous work with mesa stripe lasers, permitting improved sensitivity for measurement of small optical absorption. Minimum detectable absorption well below 10(-5) is measured at a laser power of 3 microW, in good agreement with signal-to-noise calculations using the experimental values of the FM and AM modulation indices. Optical heterodyne detection with two-tone modulation at 145 and 155 MHz is found to be nearly an order of magnitude more sensitive than conventional second harmonic detection at kilohertz frequencies. In addition to improved detection sensitivity, the double heterostructure lasers offer the important advantages of single mode operation above liquid nitrogen temperature.

Instrumentation for the measurement of ambient humidity, incorporating a liquid nitrogen-cooled tunable lead-salt laser and a reduced pressure multipass absorption cell, was installed on the Lockheed L-1011 advanced research aircraft and tested on four flights. Humidity measurements taken over altitudes ranging from 0.76 to 10.7 km were compared to results obtained with a commercial dew point hygrometer. The flight tests showed generally good agreement between the two devices to within the estimated accuracies of the instruments. At altitudes above 8 or 9 km the hygrometer is not reliable, whereas the diode laser system exhibited very good sensitivity at the highest altitudes attained. A time response of better than 0.1 s was demonstrated. We believe that a compact diode laser instrument can ultimately measure atmospheric water vapor concentrations over a wide altitude range with an accuracy of better than 3%.