A cross-sectional analysis of medications used by patients reporting alopecia areata on the FDA adverse events reporting system

BACKGROUND

Alopecia areata (AA) is an autoimmune condition that leads to patchy, nonscarring hair loss. Its etiology remains unknown; the condition can be debilitating for patients, impacting their psychosocial wellbeing. Various triggers have been reported, ranging from genetic predisposition and infections to environmental factors. Medications have also been thought to be an inciting factor in AA.

METHODS

Using the Food and Drug Administration (FDA) Adverse Events Reporting System (FAERS), all cases reporting AA as an adverse event were used to capture associated medications and patient characteristics.

RESULTS

There were 1,331 AA cases reported as an adverse event with medication use. Monoclonal antibodies accounted for 6 out of the top 10 drugs associated with the highest number of AA cases. Males were more likely to report AA when taking adalimumab (OR: 1.79, P = 0.04) and dupilumab (OR: 2.56, P = 0.03) compared to females. Individuals between 42 and 64 years old accounted for 46.7% of AA cases. Lastly, females in older age groups showed greater odds of developing AA compared to males (OR: 1.03, P < 0.01).

CONCLUSIONS

Based on the FAERS, there has been a steady rise in AA cases, and monoclonal antibodies were the most frequently cited medication class tied to AA. With a dearth of literature on triggers and patient demographics, we sought to describe features of AA cases that could increase awareness and be used to improve future clinical outcomes in patients.

Real-World Experience With Teprotumumab in Patients With Dysthyroid Optic Neuropathy

BACKGROUND

Teprotumumab, an insulin-like growth factor I receptor inhibitory antibody, improved proptosis, diplopia, inflammatory signs/symptoms, and quality of life in patients with active thyroid eye disease (TED) in clinical trials. The trials excluded patients with dysthyroid optic neuropathy (DON). Recently, many case reports and case series have reported the successful use of teprotumumab to treat DON. Here, we review the data from published cases and our clinical experience in treating patients having DON with teprotumumab.

METHODS

A literature search was conducted of patients with DON treated with teprotumumab from January 2020 through September 2022. Data from DON patients from the authors' (M.A.T. and C.A.B.) clinical practice were included. Primary outcome measure was mean (SD) improvements for visual acuity, color vision, and visual fields. Improvements in proptosis and clinical activity score (CAS) and diplopia were compared before and after teprotumumab administration.

RESULTS

Ten observational studies/case reports were identified along with 2 patients in our practice. In all, there were 24 active TED patients with DON (37 eyes) who were treated with teprotumumab. Mean (SD) age was 66.5 (13.6) years and 13 (54%) were females, disease duration ranged from 2 months to >15 years. 22/24 patients had none, minimal improvement or progression of visual loss with intravenous/oral corticosteroids, orbital decompression (n = 9), and orbital radiation (n = 2). There were 2 patients who received teprotumumab as the only therapy. Overall, 88% (21/24) reported improvement in visual acuity after teprotumumab and in 75% (18/24), improvement in vision was observed after just 2 infusions of teprotumumab. Three eyes had decompression surgery in close proximity to teprotumumab infusions and were excluded from analyses. Mean (SD) improvement in visual acuity was 3.73 lines (SD 3.74), range 2-15 lines in 33 eyes. The mean (SD) improvement in the mean deviation on visual field testing in 15 eyes was 5.6 db (3.0 db). Mean (SD) improvement in proptosis was 4.37 mm (SD: 2.11) (20 patients, 32 eyes); and clinical activity score: mean reduction of 5.1 (1.3) for 18 patients. Teprotumumab was well tolerated in all but one patient. Adverse events reported included fatigue, dysgeusia, hearing loss, nausea, hyperglycemia, and muscle spasms.

CONCLUSIONS

Teprotumumab is an effective treatment for DON in our experience and in published cases in whom treatment with steroids, surgery, or orbital radiation was unsuccessful.

The association of stroke with herpes zoster ophthalmicus

BACKGROUND/OBJECTIVES

Studies have reported an association between herpes zoster ophthalmicus (HZO) and stroke. We sought to validate this association with rigorous controls for both medical comorbidities and social factors using a nationwide U.S. administrative medical claims database.

SUBJECTS/METHODS

A two-step approach was taken: first a retrospective case-control study was performed, followed by a self-controlled case series (SCCS). For the case control study, cox proportional hazard regression with inverse proportional treatment weighting assessed the hazard for stroke. In the SCCS, incidence of stroke was compared prior to and after the diagnosis of HZO.

RESULTS

For the case-control study, 25,720 cases and 75,924 controls met our eligibility criteria. 1712 (6.7%) and 4544 (6.0%) strokes occurred in the case and control groups respectively, conferring an 18% increased risk of stroke in the observed 1-year post-HZO period (HR = 1.18, 95% CI: 1.12-1.25, p < 0.001). SCCS analysis showed the risk for stroke was highest in the month immediately after HZO episode compared to any other time range (1-30 days after, relative risk 1.58, p < 0.001) and even higher when assessing time more distal time points prior to the HZO diagnosis (days 1-30 after HZO diagnosis had RR = 1.69 (95% CI: 1.38-2.07) and RR = 1.93 (95% CI: 1.55-2.39) compared with days -120 to -91 and -150 to -121 prior to index, respectively (p < 0.001).

CONCLUSIONS

After accounting for stroke risk factors, our analysis confirms the association between HZO and stroke, with highest risk in the immediate month after an episode.

The distribution of industry payments among pediatric dermatologists from 2015 to 2021

BACKGROUND/OBJECTIVES

To understand the landscape of industry payments to pediatric dermatologists to foster transparency and identify potential disparities in funding.

METHODS

Using the Centers for Medicare and Medicaid Services (CMS) Open Payments database, a national cross-sectional study was performed examining payments to pediatric dermatologists from 2015 to 2021.

RESULTS

Of the 147 pediatric dermatologists who received industry funding, 35 were male and 112 were female. $9 million in payments was amassed, with 10% of pediatric dermatologists accounting for 94% of total industry payments. Consulting was the most common service, with Pfizer Inc., Amgen Inc., and Regeneron Healthcare Solutions Inc. representing the top three companies. Mean payment was $143,836 for males and $35,943 for females (p < .001). Eight female and seven male pediatric dermatologists received payments in the top 10th percentile, with different average payment in this subgroup (females $447,588 vs. males $698,746, p = .03). 11 states did not have a pediatric dermatologist receiving industry payments, while California (19) and Texas (12) had the most.

CONCLUSIONS

There are approximately 400 board-certified pediatric dermatologists in the United States and fewer than 40% are receiving monetary compensation from private industry. A fraction of physicians accounted for a majority of total industry payments and industry payments to male pediatric dermatologists were higher despite nearly triple the number of female pediatric dermatologists. With the rise of valuable partnerships between healthcare and industry in modern medicine, the implications of geographic, gender, and financial disparity of industry payments in pediatric dermatology are worthy of further study.

The top 100 most cited Mohs micrographic surgery articles: an analysis of Altmetrics data from 2010 to 2020

With skin cancer rates rising, there is a consistent stream of literature published on Mohs micrographic surgery (MMS). However, there are no studies examining MMS article visibility and readership patterns. The Altmetric Attention Score (AAS) is a metric that quantifies article distribution on media platforms. We analyzed the 100 most cited MMS publications from 2010 to 2020 and constructed multivariate regression models using top 25th percentile AASs and mentions on Facebook, Twitter, and new outlets as outcome variables. Articles with an AAS in the top 25th quartile consistently performed better with higher citations, Twitter mentions, Facebook mentions, and journal impact factors compared to articles in the lower three quartiles (53.8 vs 33.9; 4.68 vs 0.44; 0.32 vs 0.08; 53.5 vs 14.6; p < 0.05 for all). There were significantly lower female last authors versus males in the top quartile of AAS articles, with males 142 times more likely to have articles in the top quartile (p < 0.05). Studies comparing MMS to other surgical techniques and funded articles had higher odds of being in the top quartile of AASs (aOR 29.63 p < 0.05; aOR 74.50 p < 0.05). AASs can be useful to understand public interest, readership, and article features that influence the reach of MMS literature.

Utility of diffusion-weighted imaging to differentiate benign and malignant solid orbital tumours

OBJECTIVE

We assessed the utility of apparent diffusion coefficients (ADCs) derived from diffusion-weighted imaging to differentiate benign and malignant orbital tumours by oculoplastic surgeons in the clinical setting and sought to validate observed ADC cut-off values.

DESIGN AND PARTICIPANTS

Retrospective review of patients with benign or malignant biopsy-confirmed orbital tumours.

METHODS

Blinded graders including 2 oculoplastic surgeons, 1 neuroradiologist, and 1 medical student located and measured orbital tumour ADCs (10-6 mm2/s) using the Region of Interest tool.

OUTCOME MEASURES

Nonradiologist measurements were compared with each other to assess reliability and with an expert neuroradiologist measurement and final pathology to assess accuracy.

RESULTS

Twenty-nine orbital tumours met inclusion criteria, consisting of 6 benign tumours and 23 malignant tumours. Mean ADC values for benign orbital tumours were 1430.59 ± 254.81 and 798.68 ± 309.12 mm2/s for malignant tumours. Our calculated optimized ADC cut-off to differentiate benign from malignant orbital tumours was 1120.84 × 10-6 mm2/s (sensitivity 1, specificity 0.9). Inter-rater reliability was excellent (intraclass correlation coefficient = 0.92; 95% CI, 0.86-0.96). Our 3 graders had a combined accuracy of 84.5% (92.3%, 92.3%, and 65.4%).

CONCLUSIONS

Our ADC cut-off of 1120.84 × 10-6 mm2/s for benign and malignant orbital tumours agrees with previously established values in literature. Without priming with instructions, training, or access to patient characteristics, most tumours were correctly classified using rapid ADC measurements. Surgeons without radiologic expertise can use the ADC tool to quickly risk stratify orbital tumours during clinic visits to guide patient expectations and further work-up.

Artificial Intelligence Automation of Proptosis Measurement: An Indicator for Pediatric Orbital Abscess Surgery

INTRODUCTION

To evaluate the ability of artificial intelligence (AI) software to quantify proptosis for identifying patients who need surgical drainage.

METHODS

We pursued a retrospective study including 56 subjects with a clinical diagnosis of subperiosteal orbital abscess (SPOA) secondary to sinusitis at a tertiary pediatric hospital from 2002 to 2016. AI computer software was developed to perform 3D visualization and quantitative assessment of proptosis from computed tomography (CT) images acquired at the time of hospital admission. The AI software automatically computed linear and volume metrics of proptosis to provide more practice-consistent and informative measures. Two experienced physicians independently measured proptosis using the interzygomatic line method on axial CT images. The AI software and physician proptosis assessments were evaluated for association with eventual treatment procedures as standalone markers and in combination with the standard predictors.

RESULTS

To treat the SPOA, 31 of 56 (55%) children underwent surgical intervention, including 18 early surgeries (performed within 24 h of admission), and 25 (45%) were managed medically. The physician measurements of proptosis were strongly correlated (Spearman r = 0.89, 95% CI 0.82-0.93) with 95% limits of agreement of ± 1.8 mm. The AI linear measurement was on average 1.2 mm larger (p = 0.007) and only moderately correlated with the average physicians' measurements (r = 0.53, 95% CI 0.31-0.69). Increased proptosis of both AI volumetric and linear measurements were moderately predictive of surgery (AUCs of 0.79, 95% CI 0.68-0.91, and 0.78, 95% CI 0.65-0.90, respectively) with the average physician measurement being poorly to fairly predictive (AUC of 0.70, 95% CI 0.56-0.84). The AI proptosis measures were also significantly greater in the early as compared to the late surgery groups (p = 0.02, and p = 0.04, respectively). The surgical and medical groups showed a substantial difference in the abscess volume (p < 0.001).

CONCLUSION

AI proptosis measures significantly differed from physician assessments and showed a good overall ability to predict the eventual treatment. The volumetric AI proptosis measurement significantly improved the ability to predict the likelihood of surgery compared to abscess volume alone. Further studies are needed to better characterize and incorporate the AI proptosis measurements for assisting in clinical decision-making.

Interface fluid syndrome after LASIK surgery: retrospective pooled analysis and systematic review

Interface fluid syndrome (IFS) is a complication associated with laser in situ keratomileusis (LASIK) surgery where a fluid pocket in the corneal stroma decreases visual acuity. A systematic review of IFS cases using PRISMA guidelines was performed yielding a total of 33 patients. 2 outcomes were selected for logistic regression analysis: final corrected distance visual acuity (CDVA) and need for surgical management. Results showed 33.3% of patients required surgery, 51.5% had their IFS resolve within 1 month or sooner, and 51.5% had final CDVA 20/25 or better. Higher presenting intraocular pressure (IOP) and duration of IFS ≤1 month was associated with higher odds of final CDVA 20/25 or better (adjusted odds ratio [aOR] 1.12, P = .04; aOR 7.71, P = .02, respectively). Endothelial cell dysfunction led to 17.55 greater odds for requiring surgical compared to medical management (aOR 0.36, P = .04). Presenting IOP and duration of IFS predicted final CDVA, while prior endothelial cell dysfunction predicted need for surgery.

More than just a stye: identifying seasonal patterns using google trends, and a review of infodemiological literature in ophthalmology

PURPOSE

We aim to evaluate the utility of internet search query data in ophthalmology by: (1) Evaluating trends in searches for styes in the United States and worldwide, and (2) Performing a review of literature of infodemiological data in ophthalmology.

METHODS

Google Trends search data for "stye" was analyzed from January 2004 to January 2020 in the United States and worldwide. Spearman's correlation coefficient and sinusoidal modeling were performed to assess the significance and seasonality of trends. Review of literature included searches for "ophthalmology Google trends," "ophthalmology twitter trends," "ophthalmology infodemiology," "eye google trends," and "social media ophthalmology."

RESULTS

Searches for styes were cyclical in the United States and globally with a steady increase from 2004 to 2020 (sum-of-squares F-test for sinusoidal model: p < .0001, r² = 0.96). Peak search volume index (SVI) months were 7.9 months in the United States and 6.8 months worldwide. U.S. temperature and SVI for stye were correlated in the United States at the state, divisional, and country-wide levels (p < .005; p < .005; p < .01 respectively). Seven articles met our literature review inclusion criteria.

CONCLUSIONS

We present a novel finding of seasonality with global and U.S. searches for stye, and association of searches with temperature in the United States. Within ophthalmology, infodemiological literature has been used to track trends and identify seasonal disease patterns, perform disease surveillance, improve resource optimization by identifying regional hotspots, tailor marketing, and monitor institutional reputation. Future research into this domain may help identify further trends, improve prevention efforts, and reduce medical costs.

Association of Proton Pump Inhibitor/Histamine-2 Blocker Use and Ocular Toxoplasmosis: Findings from a Large US National Database

OBJECTIVE

To test the hypothesis that the use of proton pump inhibitors (PPIs) is associated with an increased risk of being diagnosed with toxoplasmic retinochoroiditis.

DESIGN

Retrospective, matched case-control study using data from 2000 to 2020.

PARTICIPANTS

Patients with ocular toxoplasmosis and controls were matched 5:1 for age, sex, and race, with the eligibility date ± 3 months from the index date of exposed match. Patients aged < 18 years with congenital toxoplasmosis, having < 2 years in the insurance plan before the index date, and without ≥ 1 visit to an eyecare provider before the index date were excluded from the study.

METHODS

Patients with ocular toxoplasmosis were identified using the International Classification of Diseases, Ninth Revision and International Classification of Diseases, Tenth Revision codes, and PPI use or diseases highly associated with PPIs were identified using national drug codes from an administrative medical claims database.

MAIN OUTCOME MEASURES

The primary outcome was defined as having a prescription for a PPI or histamine-2 (H2) blocker. Multivariable logistic regression analyses were performed, controlling for demographic and systemic health variables.

RESULTS

A total of 4069 cases and 19 177 controls met the eligibility criteria. Of the 4069 patients with ocular toxoplasmosis, 989 (24.3%) were on PPI/H2 blockers compared with 3763 of 19 177 (19.2%) controls. The adjusted logistic regression model demonstrated 1.28 greater odds of PPI/H2 blocker use in cases of ocular toxoplasmosis than matched controls (95% confidence interval, 1.17-1.40; P < 0.001).

CONCLUSIONS

Proton pump inhibitor/H2 blocker exposure was associated with an increased risk of being diagnosed with ocular toxoplasmosis, corroborating findings from a prior case series.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found after the references.

Risk factors for enucleation or evisceration in endophthalmitis

PURPOSE

To identify clinical risk factors for enucleation or evisceration in patients with endophthalmitis at an academic institution.

METHODS

A retrospective review of patients diagnosed with endophthalmitis at Wilmer Eye Institute from 2010 to 2019 was conducted. Clinical characteristics, including demographics, cause for endophthalmitis, microbial culture results, salvaging procedures and surgical intervention were recorded. In patients who underwent enucleation or evisceration, type of surgery and placement of a primary implant were recorded. Chi-squared, Student's t-tests and multivariate analysis were used to identify clinical factors that predicted enucleation or evisceration.

RESULTS

Two hundred and fifty three patients treated for endophthalmitis over the study period were identified, of which 25 (9.88%) underwent enucleation or evisceration. Risk factors for enucleation or evisceration included poor presenting visual acuity (OR 7.86, CI: 2.26, 27.3), high presenting intraocular pressure (OR 1.07, CI: 1.03, 1.12), presence of relative afferent pupillary defect (OR 3.69, CI: 1.20, 11.37) and positive vitreous culture for methicillin-resistant staphylococcus aureus (MRSA) (OR 18.3, CI: 1.54, 219.2) on multivariate analysis. Patients undergoing enucleation or evisceration were also more likely to have trauma, corneal ulcer or combined causes for endophthalmitis and underwent fewer salvaging surgical and procedural interventions. There were no significant differences in characteristics of those receiving enucleation versus evisceration in our cohort.

CONCLUSION

Patients with endophthalmitis who underwent enucleation or evisceration had more severe disease on presentation compared to those treated with eye sparing therapy. Presenting clinical characteristics may have a role in triage and management decisions for patients presenting with severe endophthalmitis.

Predictive Factors of Research Productivity among Ophthalmology Residents: A Benchmark Analysis

Introduction Positive and negative associations between prior publications and future research productivity is described in other fields, but no such analysis exists for ophthalmology. We conducted a study to determine characteristics of residents exhibiting research productivity during residency.

Methods Using San Francisco Match and Program Web sites, a roster of ophthalmology residents in 2019 to 2020 was compiled, and publication data was collected via PubMed and Google Scholar on a random sample of 100 third-year residents.

Results The median number of publications generated by ophthalmology residents before residency is 2 (range 0–13). Thirty-seven, 23, and 40 residents had zero, one, and two or more papers published during residency, respectively, with a median of 1 (range 0–14). On univariate analysis, compared with residents who published zero or one paper, those who published ≥ 2 were more likely to have more preresidency publications (odds ratio [OR] 1.30; p = 0.005), attend a top-25 ranked residency program by multiple metrics including Doximity reputation (OR 4.92; p < 0.001), and have attended a top-25 ranked medical school program by U.S. News and World Report (OR 3.24; p = 0.03). However, on adjusted analyses, the only factor that remained significant for predicting publications in residency was whether the residency program attended was top 25 ranked (OR 3.54; p = 0.009).

Discussion/Conclusion With the advent of the United States Medical Licensing Examination Step 1 pass/fail system, greater emphasis will be placed on other metrics, including research. This is the first benchmark analysis examining factors predictive of publication productivity in ophthalmology residents. Our study suggests that the residency program attended, not the medical school attended or prior publication history, plays an influential role in the number of publications produced during residency, highlighting the importance of factors to support research on the institutional level, such as mentorship and funding, rather than historical factors in research productivity by the resident.

Neuroimaging correlates of syndromal depression following traumatic brain injury: A systematic review of the literature

Objective

To complete a systematic review of the literature examining neuroimaging findings unique to co-occurring syndromal depression in the setting of TBI.

Methods

A PRISMA compliant literature search was conducted in PubMed (MEDLINE), PsychINFO, EMBASE, and Scopus databases for articles published prior to April of 2022. The database query yielded 4447 unique articles. These articles were narrowed based on specific inclusion criteria (e.g., clear TBI definition, clear depression construct commenting on the syndrome of major depressive disorder, conducted empirical analyses comparing neuroimaging correlates in TBI subjects with depression versus TBI subjects without depression, controlled for the time interval between TBI occurrence and acquisition of neuroimaging).

Results

A final cohort of 10 articles resulted, comprising the findings from 423 civilians with brain injury, 129 of which developed post-TBI depression. Four articles studied mild TBI, three mild/moderate, one moderate/severe, and two all-comers, with nine articles focusing on single TBI and one including both single and recurrent injuries. Spatially convergent structural abnormalities in individuals with TBI and co-occurring syndromal depression were identified primarily in bilateral frontal regions, particularly in those with damage to the left frontal lobe and prefrontal cortices, as well as temporal regions including bilateral temporal lobes, the left superior temporal gyrus, and bilateral hippocampi. Various parietal regions and the nucleus accumbens were also implicated. EEG studies showed supporting evidence of functional changes in frontal regions.

Conclusion

Additional inquiry with attention to TBI without depression control groups, consistent TBI definitions, previous TBI, clinically diagnosed syndromal depression, imaging timing post-injury, acute prospective design, functional neuroimaging, and well-defined neuroanatomical regions of interest is crucial to extrapolating finer discrepancies between primary and TBI-related depression.

Adequacy of samples obtained via percutaneous core-needle rebiopsy for EGFR T790M molecular analysis in patients with non-small cell lung cancer following acquired resistance to first-line therapy: A systematic review and meta-analysis

MICRO ABSTRACT

Rebiopsies characterizing resistance mutations in patients with non-small cell lung cancer (NSCLC) can guide personalized medicine and improve overall survival rates. In this systematic review, we examine the suitability of percutaneous core-needle biopsy (PT-CNB) to obtain adequate samples for molecular characterization of the acquired resistance mutation T790M. This review provides evidence that PT-CNB can obtain samples with high adequacy, with a mutation detection rate that is in accordance with prior literature.

BACKGROUND

Non-small cell lung cancer (NSCLC) comprises 85% of all lung cancers and has seen improved survival rates with the rise of personalized medicine. Resistance mutations to first-line therapies, such as T790M, however, render first-line therapies ineffective. Rebiopsies characterizing resistance mutations inform therapeutic decisions, which result in prolonged survival. Given the high efficacy of percutaneous core-needle biopsy (PT-CNB), we conducted the first systematic review to analyze the ability of PT-CNB to obtain samples of high adequacy in order to characterize the acquired resistance mutation T790M in patients with NSCLC.

METHODS

We performed a comprehensive literature search across PubMed, Embase, and CENTRAL. Search terms related to "NSCLC," "rebiopsy," and "PT-CNB" were used to obtain results. We included all prospective and retrospective studies that satisfied our inclusion and exclusion criteria. A random effects model was utilized to pool adequacy and detection rates of the chosen articles. We performed a systematic review, meta-analysis, and meta-regression to investigate the adequacy and T790M detection rates of samples obtained via PT-CNB.

RESULTS

Out of the 173 studies initially identified, 5 studies met the inclusion and exclusion criteria and were chosen for our final cohort of 436 patients for meta-analysis. The pooled adequacy rate of samples obtained via PT-CNB was 86.92% (95% CI: [79.31%, 92.0%]) and the pooled T790M detection rate was 46.0% (95% CI: [26.6%, 66.7%]). There was considerable heterogeneity among studies (I² > 50%) in both adequacy and T790M detection rates.

CONCLUSION

PT-CNB can obtain adequate samples for T790M molecular characterization in NSCLC lung cancer patients. Additional prospective studies are needed to corroborate the results in this review.

Neuroimaging Correlates of Syndromal Anxiety Following Traumatic Brain Injury: A Systematic Review of the Literature

BACKGROUND

Traumatic brain injury (TBI) can precipitate new-onset psychiatric symptoms or worsen existing psychiatric conditions. To elucidate specific mechanisms for this interaction, neuroimaging is often used to study both psychiatric conditions and TBI. This systematic review aims to synthesize the existing literature of neuroimaging findings among patients with anxiety after TBI.

METHODS

We conducted a Preferred Reporting Items for Systematic Review and Meta-Analyses-compliant literature search via PubMed (MEDLINE), PsychINFO, EMBASE, and Scopus databases before May, 2019. We included studies that clearly defined TBI, measured syndromic anxiety as a primary outcome, and statistically analyzed the relationship between neuroimaging findings and anxiety symptoms.

RESULTS

A total of 5982 articles were retrieved from the systematic search, of which 65 studied anxiety and 13 met eligibility criteria. These studies were published between 2004 and 2017, collectively analyzing 764 participants comprised of 470 patients with TBI and 294 non-TBI controls. Imaging modalities used included magnetic resonance imaging, functional magnetic resonance imaging, diffusion tensor imaging, electroencephalogram, magnetic resonance spectrometry, and magnetoencephalography. Eight of 13 studies presented at least one significant finding and together reflect a complex set of changes that lead to anxiety in the setting of TBI. The left cingulate gyrus in particular was found to be significant in 2 studies using different imaging modalities. Two studies also revealed perturbances in functional connectivity within the default mode network.

CONCLUSIONS

This is the first systemic review of neuroimaging changes associated with anxiety after TBI, which implicated multiple brain structures and circuits, such as the default mode network. Future research with consistent, rigorous measurements of TBI and syndromic anxiety, as well as attention to control groups, previous TBIs, and time interval between TBI and neuroimaging, are warranted. By understanding neuroimaging correlates of psychiatric symptoms, this work could inform future post-TBI screening and surveillance, preventative efforts, and early interventions to improve neuropsychiatric outcomes.

Automated delineation of orbital abscess depicted on CT scan using deep learning

OBJECTIVES

To develop and validate a deep learning algorithm to automatically detect and segment an orbital abscess depicted on computed tomography (CT).

METHODS

We retrospectively collected orbital CT scans acquired on 67 pediatric subjects with a confirmed orbital abscess in the setting of infectious orbital cellulitis. A context-aware convolutional neural network (CA-CNN) was developed and trained to automatically segment orbital abscess. To reduce the requirement for a large dataset, transfer learning was used by leveraging a pre-trained model for CT-based lung segmentation. An ophthalmologist manually delineated orbital abscesses depicted on the CT images. The classical U-Net and the CA-CNN models with and without transfer learning were trained and tested on the collected dataset using the 10-fold cross-validation method. Dice coefficient, Jaccard index, and Hausdorff distance were used as performance metrics to assess the agreement between the computerized and manual segmentations.

RESULTS

The context-aware U-Net with transfer learning achieved an average Dice coefficient and Jaccard index of 0.78 ± 0.12 and 0.65 ± 0.13, which were consistently higher than the classical U-Net or the context-aware U-Net without transfer learning (P < 0.01). The average differences of the abscess between the computerized results and the experts in terms of volume and Hausdorff distance were 0.10 ± 0.11 mL and 1.94 ± 1.21 mm, respectively. The context-aware U-Net detected all orbital abscess without false positives.

CONCLUSIONS

The deep learning solution demonstrated promising performance in detecting and segmenting orbital abscesses on CT images in strong agreement with a human observer.

Trends in Anti-VEGF Injection Medicare Part B Claims among Male and Female Ophthalmologists from 2012-2016

Background: Compared to male ophthalmologists, female ophthalmologists have significantly reduced salaries, fewer faculty roles and authored publications, garnered less federal research funding, and achieved less editorial advancement. We aimed to use the most recently available Centers for Medicare and Medicaid Services data to characterize trends and differences in anti-VEGF reimbursements coded for by male and female ophthalmologists.Methods: We used Medicare Fee-For Service Provider Utilization and Payment Data: Part B Provider public use files for 2012-2016 to quantify service and reimbursement patterns for anti-VEGF injections between male and female ophthalmologists. Five outcome variables were studied: number of providers, average Medicare payment amount, total payment, number of services, and number of Medicare beneficiaries.Results: Number of services performed per female provider was 71.2% that of a male ophthalmologist in 2012, and this percentage did not change from 2012 to 2016 (95%CI [0.63, 0.804], [0.984, 1.04], respectively). Female providers had 76.1% of beneficiaries as males in 2012, and this percentage stayed constant throughout the years (95%CI [0.69, 0.84] and [0.99, 1.03], respectively). The total payment difference between female and males was $102,175 per provider in 2012, and this gap widened by $18,292 yearly (95% CI [-162599.17, -41760.47], [-33060.35, -3524.38], respectively).Conclusion: While male and female providers saw considerable increases in aflibercept services and payments in the 5-year period, the gap between male and female reimbursements widened significantly. Moving forward, analysis of large-scale Medicare datasets provides a tangible report card on how effective our attitudes and policies are in cultivating equal opportunity.

Lesion-Mapping Software for the Measurement of Subperiosteal Abscess Volume for Pediatric Orbital Cellulitis: A Retrospective Chart Review

Introduction

Our objective was to assess the utility of using lesion-mapping software to calculate precise orbital volumes to predict patients who would benefit from early surgical intervention.

Methods

We retrospectively reviewed patients diagnosed with subperiosteal orbital abscess (SPOA) secondary to sinusitis at a tertiary pediatric hospital from 2005 to 2016. Diagnoses were confirmed by CT scans. Lesion-mapping software was used to measure SPOA volume using initial CT images. Data collected included patient demographics, length of hospital stay, and subsequent medical or surgical treatment.

Results

Thirty-three (52%) patients ultimately underwent surgical intervention, while 30 (48%) were managed medically. Between the surgical and medical groups, there were no differences in gender, age, or comorbidities. The surgical group had larger abscess volumes than the medically managed group (0.94 mL vs. 0.31 mL, p < 0.01). Overall, increased SPOA volume was associated with increased age (Pearson’s coefficient = 0.374, p ≤ 0.01) and increased total days of intravenous (IV) antibiotic administration (Pearson’s coefficient = 0.260, p = 0.039). Patients who underwent surgery on the day of admission had 25% shorter hospital stay than patients who had delayed surgery (p < 0.01). Our calculated sensitivity-optimized SPOA volume cutoff of 0.231 mL yielded sensitivity of 90.9% and specificity of 70.0%.

Conclusions

This is the first study to use lesion-mapping software for precise calculation of SPOA volumes, which can help refine indications for early surgical intervention and help decrease length of hospital stay.

Ocular adnexal metastases from renal cell carcinoma: An update and comprehensive literature review

PURPOSE:

The purpose of this study was to review the clinical presentation, systemic work-up, and outcomes of all previously reported ocular adnexal (OA) metastases from renal cell carcinoma (RCC).

METHODS:

This was a literature review. PubMed and Google Scholar databases were searched for all well-documented cases of OA metastases from RCC.

RESULTS:

Final analysis identified 44 patients with either biopsy-confirmed (41/44, 93%) or treatment response-documented (3/44, 6%) OA metastases from RCC. Thirty-four (77%) patients were male. The median age was 60 years (mean: 60, range: 22–87 years). The most common presenting signs were proptosis (19/44, 43%) and OA mass (14/44, 32%). Metastases most frequently involved the orbital bones (10/44, 23%) and adjacent extraconal fat, extending from the sinonasal tract in 7/10 (70%) of these cases. OA metastases were initial manifestation of RCC in 18/44 (41%) patients. At the time of primary tumor diagnosis, 22 of 30 (73%) patients had American Joint Committee on Cancer Stage IV disease with metastases to 2 or more sites in 13 (57%) patients. Seventeen of 42 (40%) patients underwent local therapy only, which most commonly included excision/exenteration with margin control (10/17, 59%). Twenty-five of 42 (60%) patients had systemic therapy, which included biologic agents and chemotherapy. The absolute 5-year survival rate was 66% with significantly improved survival in patients reported after 2006 (92% vs. 42%, P = 0.04) and in those with isolated OA metastases (100% vs. 27%, P = 0.02) at 30 months.

CONCLUSION:

Although RCC metastases to OA occur in a setting of advanced disease, the recent advances in diagnostic modalities and targeted therapies resulted in improved survival.

Peripheral-to-central ratio of Guttae: validity and reliability of an objective method to characterize severity of Fuchs endothelial corneal dystrophy

PURPOSE

Common methods of measuring severity of Fuchs endothelial corneal dystrophy (FECD) are limited in objectivity, reliability, or start with a variable baseline that prevents distinguishing healthy from affected eyes. The aim of this study was to describe a method of grading FECD that overcomes these limitations.

METHODS

Fifteen patients with Fuchs endothelial corneal dystrophy were included in the study. Guttae were imaged with a slit lamp beam 8 mm tall; the bottom 4 mm half of each image was divided into two equally-sized sections. Guttae were counted by four independent graders blinded to disease severity scores. The peripheral:central guttae ratio was compared to modified Krachmer clinical severity scores. The peripheral:central guttae ratio was compared between mild (severity 0.5-3) versus moderate-to-severe (severity 4-5) disease. Receiver operating characteristics defined optimal ratio cutoffs for mild versus moderate-to-severe disease.

RESULTS

Increased peripheral guttae and peripheral:central guttae ratio correlated with Krachmer severity (p = 0.021 and p = 0.009, respectively). The difference between mild and moderate-to-severe cases for the peripheral:central guttae ratio was significant (p < 0.001). Inter-rater reliability of total guttae count was high (coefficient = 0.82, p < 0.001). A peripheral:central guttae ratio of 0.16 was the ideal cut-off point (area under the curve = 0.79, sensitivity = 0.78, and specificity = 0.80).

CONCLUSION

In this pilot study, the peripheral:central ratio of guttae correlates with subjective clinical severity of Fuchs dystrophy. It starts at a common baseline, has good inter-rater reliability, does not require dilation, and can be conducted with a smartphone and slit-lamp.

Testing a Popular Smartphone Application for Colour Vision Assessment in Healthy Volunteer Subjects

We aimed to compare the Ishihara pseudoisochromatic colour vision test with a colour vision test from a popular smartphone application (EyeHandBook [EHB]) using digital image processing to simulate colour vision deficiencies. Three digital versions of the Ishihara and EHB slides were created: full colour; 32 bit- greyscale (removing all colour information); and blue channel (to simulate red-green colour vision deficiencies). Twenty healthy volunteers were shown each colour-edited plate. The answers they reported were compared with what would be expected for that colour-simulation scenario based on the answer key provided in the Ishihara booklet ("expected" answer). There were nine plates that had comparable patterns between the EHB and Ishihara test. We found no significant difference in the overall proportion of "expected" answers for the full colour (p = .35), 32 bit-greyscale (p = .39) and blue channel (p = .22) conditions. There were significant differences between the proportion of "expected" answers among six individual colour- edited plates (p < .05 for each). Colour vision assessment from the EHB is distinct from comparable Ishihara plates. Clinical scenarios that require serial assessment of colour vision may benefit from using the same modality consistently rather than exchanging between the two tests with the assumption of equivalence. Refinement of digital colour editing techniques beyond 32-bit greyscale and RGB channel splitting is necessary in order to accurately simulate colour vision deficiency.

Eye injuries in the National Hockey League from 2010 to 2018: an analysis of injury rates, mechanisms, and the National Hockey League visor policy

OBJECTIVE

We aim to assess the efficacy of widespread visor adoption by assessing eye injury rates during the 2010-2018 seasons. We also compare injury rates, missed games, and financial losses to previously reported data in order to track progress over time. Lastly, we characterize the mechanism and type of eye injuries sustained by National Hockey League (NHL) players to examine risk areas within NHL games.

DESIGN

We performed a retrospective review of NHL player injuries using official NHL team reports, ProSportsTransactions, and TSN Sports.

PARTICIPANTS

All NHL players who suffered an eye injury from 2010 to 2018 were included; 31 injuries matched this criterion.

METHODS

Trends in injuries, missed games, and financial losses over time were analyzed using Pearson's correlation coefficients. Wilcoxon-Mann-Whitney tests were performed to compare our data with eye injury data. Fisher's exact test was performed to assess significance between mechanism and type of eye injury and outcome.

RESULTS

There were 31 total eye injuries causing 233 missed games and a total of US$8 951 000 in financial losses across the 2010-2018 seasons. There was a strong decrease in the number of eye injuries (r = -0.83, p = 0.01) and a moderate decrease in number of missed games (r = -0.62, p = 0.09). Injuries due to direct puck strikes contributed to over US$6.5 million in financial losses and led to significantly more missed games compared with stick injuries (14.6 vs 4.3).

CONCLUSION

We tangibly demonstrate the financial and physical effects of recent safety interventions and indicate areas for improved safety in the NHL.

Seasonal variability in public searches of keratosis pilaris: How the internet can illuminate a pattern in public interest

In this study, we examine keratosis pilaris search patterns using Google Trends to determine any seasonality. Monthly searches were collected from January 2004 to January 2020 using "keratosis pilaris" as the search term in the Google Trends database. The US search data were compared to monthly temperatures and tested for correlation. Worldwide search interest was also acquired and, along with the US data, a two-model analysis was performed to determine any seasonal patterns. Peaks in search interest closely overlapped with higher temperatures in the United States and showed correlation (.44; P < .0001). The US and worldwide search interest also exhibited seasonality, which was confirmed with a sinusoidal regression being the best-fit model (R² = .867 and .895). These results show higher search volume during warmer months in the United States and a clear cyclical pattern in searches worldwide and in the United States. Examination of these trends could elucidate peaks that health care providers may not have been aware of yielding improved resource allocation and preparedness for larger volume periods. This information in conjunction with clinical data could also shed more light in the future on potential peak seasons of incidence and prevalence.

History of traumatic brain injury interferes with accurate diagnosis of Alzheimer's dementia: a nation-wide case-control study

Traumatic brain injury (TBI) and Alzheimer's disease (AD) bear a complex relationship, potentially increasing risk of one another reciprocally. However, recent evidence suggests post-TBI dementia exists as a distinct neurodegenerative syndrome, confounding AD diagnostic accuracy in clinical settings. This investigation sought to evaluate TBI's impact on the accuracy of clinician-diagnosed AD using gold standard neuropathological criteria. In this preliminary analysis, data were acquired from the National Alzheimer's Coordinating Centre (NACC), which aggregates clinical and neuropathologic information from Alzheimer's disease centres across the United States. Modified National Institute on Aging-Reagan criteria were applied to confirm AD by neuropathology. Among participants with clinician-diagnosed AD, TBI history was associated with misdiagnosis (false positives) (OR = 1.351 [95% CI: 1.091-1.674], p = 0.006). Among participants without clinician-diagnosed AD, TBI history was not associated with false negatives. TBI moderates AD diagnostic accuracy. Possible AD misdiagnosis can mislead patients, influence treatment decisions, and confound research study designs. Further work examining the influence of TBI on dementia diagnosis is warranted.

UPLC and ESI-MS analysis of metabolites of Rauvolfia tetraphylla L. and their spatial localization using desorption electrospray ionization (DESI) mass spectrometric imaging

Rauvolfia tetraphylla L. (family Apocynaceae), often referred to as the wild snakeroot plant, is an important medicinal plant and produces a number of indole alkaloids in its seeds and roots. The plant is often used as a substitute for Ravuolfia serpentine (L.) Benth. ex Kurz known commonly as the Indian snakeroot plant or sarphagandha in the preparation of Ayurvedic formulations for a range of diseases including hypertension. In this study, we examine the spatial localization of the various indole alkaloids in developing fruits and plants of R. tetraphylla using desorption electrospray ionization mass spectrometry imaging (DESI-MSI). A semi-quantitative analysis of the various indole alkaloids was performed using UPLC-ESI/MS. DESI-MS images showed that the distribution of ajmalcine, yohimbine, demethyl serpentine and mitoridine are largely localized in the fruit coat while that for ajmaline is restricted to mesocarp of the fruit. At a whole plant level, the ESI-MS intensities of many of the ions were highest in the roots and lesser in the shoot region. Within the root tissue, except sarpagine and ajmalcine, all other indole alkaloids occurred in the epidermal and cortex tissues. In leaves, only serpentine, ajmalcine, reserpiline and yohimbine were present. Serpentine was restricted to the petiolar region of leaves. Principal component analysis based on the presence of the indole alkaloids, clearly separated the four tissues (stem, leaves, root and fruits) into distinct clusters. In summary, the DESI-MSI results indicated a clear tissue localization of the various indole alkaloids, in fruits, leaves and roots of R. tetraphylla. While it is not clear of how such localization is attained, we discuss the possible pathways of indole alkaloid biosynthesis and translocation during fruit and seedling development in R. tetraphylla. We also briefly discuss the functional significance of the spatial patterns in distribution of metabolites.

Self-propagated combustion synthesis of few-layered graphene: an optical properties perspective

This paper describes a labour efficient and cost-effective strategy to prepare few-layered of reduced graphene oxide like (RGOL) sheets from graphite. The self-propagated combustion route enables the bulk production of RGOL sheets. Microscopic and spectroscopic analyses confirmed the formation of few-layer graphene sheets of an average thickness of ∼3 nm and the presence of some oxygen functional groups with a C/O ratio of 8.74. A possible mechanistic pathway for the formation of RGOL sheets is proposed. The optical properties of the RGOL sample were studied in detail by means of Spectroscopic Ellipsometry (SE). The experimental abilities of SE in relating the optical properties with the number of oxygen functionalities present in the samples are explored. The data were analysed by a double-layered optical model along with the Drude-Lorentz oscillatory dispersion relation. The refractive index (n = 2.24), extinction coefficient (k = 2.03), and dielectric functions are obtained using point-by-point analysis and are also checked for Kramers-Kronig (KK) consistency.

Ultra-high sensitivity infra-red detection and temperature effects in a graphene-tellurium nanowire binary hybrid

The optoelectronic performance of hybrid devices from graphene and optically sensitive semiconductors exceeds conventional photodetectors due to a large in-built optical gain. Tellurium nanowire (TeNW), being a narrow direct band gap semiconductor (∼0.65 eV), is as an excellent potential candidate for near infra-red (NIR) detection. Here we demonstrate a new graphene-TeNW binary hybrid that exhibits a maximum photoresponsivity of ∼10⁶ A W^-1 at 175 K in the NIR regime (920 nm-1720 nm), which exceeds the photoresponsivity of the most common NIR photodetectors. The resulting noise-equivalent power (NEP) is as low as 2 × 10^-18 W Hz^-1/2, and the specific detectivity (D*) exceeds 5 × 10¹³ cm Hz^1/2 W^-1 (Jones). The temperature range of optimal operation, which extends up to ≈220 K and ≈260 K for 1720 nm and 920 nm excitation, respectively, is primarily limited by the electrical conductivity of the TeNW layer, and can further be improved by lowering of the defect density as well as inter-wire electronic coupling.

Qualitative observation of reversible phase change in astrochemical ethanethiol ices using infrared spectroscopy

Here we report the first evidence for a reversible phase change in an ethanethiol ice prepared under astrochemical conditions. InfraRed (IR) spectroscopy was used to monitor the morphology of the ice using the SH stretching vibration, a characteristic vibration of thiol molecules. The deposited sample was able to switch between amorphous and crystalline phases repeatedly under temperature cycles between 10K and 130K with subsequent loss of molecules in every phase change. Such an effect is dependent upon the original thickness of the ice. Further work on quantitative analysis is to be carried out in due course whereas here we are reporting the first results obtained.

Solar mediated reduction of graphene oxide

This paper explores the reduction of water dispersed graphene oxide (GO) by sunlight. The electronic and structural properties of the sunlight reduced GO are compared with that of GO reduced by conventional methods.

Rapid dehalogenation of pesticides and organics at the interface of reduced graphene oxide-silver nanocomposite

This paper reports dehalogenation of various organohalides, especially aliphatic halocarbons and pesticides at reduced graphene oxide-silver nanocomposite (RGO@Ag). Several pesticides as well as chlorinated and fluorinated alkyl halides were chosen for this purpose. The composite and the products of degradation were characterized thoroughly by means of various microscopic and spectroscopic techniques. A sequential two-step mechanism involving dehalogenation of the target pollutants by silver nanoparticles followed by adsorption of the degraded compounds onto RGO was revealed. The composite showed unusual adsorption capacity, as high as 1534 mg/g, which facilitated the complete removal of the pollutants. Irrespective of the pollutants tested, a pseudo-second-order rate equation best described the adsorption kinetics. The affinity of the composite manifested chemical differences. The high adsorption capacity and re-usability makes the composite an excellent substrate for purification of water.

Developmental patterning and segregation of alkaloids in areca nut (seed of Areca catechu) revealed by magnetic resonance and mass spectrometry imaging

Areca nut (seed of Areca catechu) is consumed by people from different parts of Asia, including India. The four major alkaloids present in areca nut are arecoline, arecaidine, guvacoline and guvacine. Upon cutting, the nut reveals two kinds of regions; white and brown. In our present study, we have monitored the formation of these two regions within the nut during maturation, using the non-invasive techniques of magnetic resonance imaging (MRI) and volume localized magnetic resonance spectroscopy (MRS). Electrospray ionization mass spectrometry (ESI MS) and desorption electrospray ionization mass spectrometry (DESI MS) imaging have been used to study the associated change in the alkaloid contents of these two regions during the growth of the nut. Our study reveals that white and brown regions start forming within the nut when the liquid within starts solidifying. At the final stage of maturity, arecoline, arecaidine and guvacoline get segregated in the brown region whereas guvacine gets to the white region of the nut. The transport of molecules with maturity and corresponding pattern formation are expected to be associated with a multitude of physiochemical changes.

A panel study of the acute effects of personal exposure to household air pollution on ambulatory blood pressure in rural Indian women

BACKGROUND

Almost half the world's population is exposed to household air pollution from biomass and coal combustion. The acute effects of household air pollution on the cardiovascular system are poorly characterized. We conducted a panel study of rural Indian women to assess whether personal exposures to black carbon during cooking were associated with acute changes in blood pressure.

METHODS

We enrolled 45 women (ages 25-66 years) who cooked with biomass fuels. During cooking sessions in winter and summer, we simultaneously measured their personal real-time exposure to black carbon and conducted ambulatory blood pressure measurements every 10min. We recorded ambient temperature and participants' activities while cooking. We assessed body mass index, socioeconomic status, and salt intake. Multivariate mixed effects regression models with random intercepts were used to estimate the associations between blood pressure and black carbon exposure, e.g., average exposure in the minutes preceding blood pressure measurement, and average exposure over an entire cooking session.

RESULTS

Women's geometric mean (GM) exposure to black carbon during cooking sessions was lower in winter (GM: 40μg/m(3); 95% CI: 30, 53) than in summer (GM: 56μg/m(3); 95% CI: 42, 76). Interquartile range increases in black carbon were associated with changes in systolic blood pressure from -0.4mm Hg (95% CI: -2.3, 1.5) to 1.9mm Hg (95% CI: -0.8, 4.7), with associations increasing in magnitude as black carbon values were assessed over greater time periods preceding blood pressure measurement. Interquartile range increases in black carbon were associated with small decreases in diastolic blood pressure from -0.9mm Hg (95% CI: -1.7, -0.1) to -0.4mm Hg (95% CI: -1.6, 0.8). Associations of a similar magnitude were estimated for cooking session-averaged values.

CONCLUSIONS

We found some evidence of an association between exposure to black carbon and acute increases in systolic blood pressure in Indian women cooking with biomass fuels, which may have implications for the development of cardiovascular diseases.

A facile method to fabricate carbon nanostructures via the self-assembly of polyacrylonitrile/poly(methyl methacrylate-b-polyacrylonitrile) AB/B′ type block copolymer/homopolymer blends

The self-assembly and high temperature behavior of AB/B′ type block copolymer/homopolymer blends containing polyacrylonitrile (PAN) polymers were studied for the first time.

Translocation of uranium from water to foodstuff while cooking

The present work report the unusual uranium uptake by foodstuff, especially those rich in carbohydrates like rice when they are cooked in water, contaminated with uranium. The major staple diet in South Asia, rice, was chosen to study its interaction with UO2(2+), the active uranium species in water, using inductively coupled plasma mass spectrometry. Highest uptake limit was checked by cooking rice at very high uranium concentration and it was found to be good scavenger of uranium. To gain insight into the mechanism of uptake, direct interaction of UO2(2+) with monosaccharides was also studied, using electrospray ionization mass spectrometry taking mannose as a model. The studies have been done with dissolved uranium salt, uranyl nitrate hexahydrate (UO2(NO3)2·6H2O), as well as the leachate of a stable oxide of uranium, UO2(s), both of which exist as UO2(2+) in water. Among the eight different rice varieties investigated, Karnataka Ponni showed the maximum uranium uptake whereas unpolished Basmati rice showed the minimum. Interaction with other foodstuffs (potato, carrot, peas, kidney beans and lentils) with and without NaCl affected the extent of chemical interaction but was not consistent with the carbohydrate content. Uranium interaction with D-mannose monitored through ESI-MS, under optimized instrumental parameters, identified the peaks corresponding to uranyl adduct with mannose monomer, dimer and trimer and the species were confirmed by MS/MS studies. The product ion mass spectra showed peaks illustrating water loss from the parent ion as the collision energy was increased, an evidence for the strong interaction of uranium with mannose. This study would constitute the essential background for understanding interaction of uranium with various foods. Extension of this work would involve identification of foodstuff as green heavy metal scavengers.

Efficient red luminescence from organic-soluble Au₂₅ clusters by ligand structure modification

An efficient method to enhance visible luminescence in a visibly non-luminescent organic-soluble 4-(tert butyl)benzyl mercaptan (SBB)-stabilized Au25 cluster has been developed. This method relies mainly on enhancing the surface charge density on the cluster by creating an additional shell of thiolate on the cluster surface, which enhances visible luminescence. The viability of this method has been demonstrated by imparting red luminescence to various ligand-protected quantum clusters (QCs), observable to the naked eye. The bright red luminescent material derived from Au25SBB18 clusters was characterized using UV-vis and luminescence spectroscopy, TEM, SEM/EDS, XPS, TG, ESI and MALDI mass spectrometry, which collectively proposed an uncommon molecular formula of Au29SBB24S, suggested to be due to different stapler motifs protecting the Au25 core. The critical role of temperature on the emergence of luminescence in QCs has been studied. The restoration of the surface ligand shell on the Au25 cluster and subsequent physicochemical modification to the cluster were probed by various mass spectral and spectroscopic techniques. Our results provide fundamental insights into the ligand characteristics determining luminescence in QCs.

Ambient ionization mass spectrometry imaging of rohitukine, a chromone anti-cancer alkaloid, during seed development in Dysoxylum binectariferum Hook.f (Meliaceae)

Rohitukine, a chromone alkaloid, possesses anti-inflammatory, anti-cancer and immuno-modulatory properties. It has been reported from four species, belonging to the families, Meliaceae and Rubiaceae. Stem bark of Dysoxylum binectariferum (Meliaceae) accumulates the highest amount of rohitukine (3-7% by dry weight). In this study, we examine the spatial and temporal distribution of rohitukine and related compounds during various stages of seed development in D. binectariferum using desorption electrospray ionization mass spectrometry imaging (DESI MSI). Rohitukine (m/z 306.2) accumulation increased from early seed development to seed maturity stage. The spatial distribution of rohitukine was largely restricted to the cotyledonary tissue followed by the embryo and least in the seed coat. Besides rohitukine, rohitukine acetate (m/z 348.2) and glycosylated rohitukine (m/z 468.2) were also detected, both through mass fragmentation and exact mass analysis through Orbitrap mass spectrometry. These results indicate a dynamic pattern of chromane alkaloid accumulation through seed development in D. binectariferum.

Rapid detection of Fusarium wilt in basil (Ocimum sp.) leaves by desorption electrospray ionization mass spectrometry (DESI MS) imaging

A rapid method to unravel the spatial distribution ofFusarium/other pathogen-contamination in asymptomatic leaves under ambient conditions.

Noble metal clusters protected with mixed proteins exhibit intense photoluminescence

Noble metal clusters in a mixed protein (BSA–Lyz) matrix lead to a better FRET and high fluorescence quantum yield.

Antimicrobial silver: an unprecedented anion effect

Silver is an indispensable metal but its use has to be minimised for sustainable growth. Much of the silver lost during use is unrecoverable; an example being its use as an antimicrobial agent, a property known since ages. While developing methods to create an affordable drinking water purifier especially for the developing world, we discovered that 50 parts per billion (ppb) of Ag⁺ released continuously from silver nanoparticles confined in nanoscale cages is enough to cause antimicrobial activity in conditions of normal water. Here we show that the antibacterial and antiviral activities of Ag⁺ can be enhanced ~1,000 fold, selectively, in presence of carbonate ions whose concentration was maintained below the drinking water norms. The protective layers of the organisms were affected during the carbonate-assisted antimicrobial activity. It is estimated that ~1,300 tons of silver can be saved annually using this new way to enhance its antimicrobial activity.

Isolation and Tandem Mass Spectrometric Identification of a Stable Monolayer Protected Silver-Palladium Alloy Cluster

A selenolate-protected Ag-Pd alloy cluster was synthesized using a one-pot solution-phase route. The crude product upon chromatographic analyses under optimized conditions gave three distinct clusters with unique optical features. One of these exhibits a molecular peak centered at m/z 2839, in its negative ion mass spectrum assigned to Ag5Pd4(SePh)12(-), having an exact match with the corresponding calculated spectrum. Tandem mass spectrometry of the molecular ion peak up to MS(9) was performed. Complex isotope distributions in each of the mass peaks confirmed the alloy composition. We find the Ag3Pd3(-) core to be highly stable. The composition was further supported by scanning electron microscopy, energy-dispersive spectroscopy, and X-ray photoelectron spectroscopy.

Reversible formation of Ag₄₄ from selenolates

The cluster Ag₄₄SePh₃₀, originally prepared from silver selenolate, upon oxidative decomposition by H₂O₂ gives the same cluster back, in an apparently reversible synthesis. Such an unusual phenomenon was not seen for the corresponding thiolate analogues. From several characterization studies such as mass spectrometry, Raman spectroscopy, etc., it has been confirmed that the degraded and as-synthesized selenolates are the same in nature, which leads to the reversible process. The possibility of making clusters from the degraded material makes cluster synthesis economical. This observation makes one to consider cluster synthesis to be a reversible chemical process, at least for selenolates.

Blue emitting undecaplatinum clusters

A blue luminescent 11-atom platinum cluster showing step-like optical features and the absence of plasmon absorption was synthesized. The cluster was purified using high performance liquid chromatography (HPLC). Electrospray ionization (ESI) and matrix assisted laser desorption ionization (MALDI) mass spectrometry (MS) suggest a composition, Pt11(BBS)8, which was confirmed by a range of other experimental tools. The cluster is highly stable and compatible with many organic solvents.

Development of ultralow energy (1-10 eV) ion scattering spectrometry coupled with reflection absorption infrared spectroscopy and temperature programmed desorption for the investigation of molecular solids

Extremely surface specific information, limited to the first atomic layer of molecular surfaces, is essential to understand the chemistry and physics in upper atmospheric and interstellar environments. Ultra low energy ion scattering in the 1-10 eV window with mass selected ions can reveal extremely surface specific information which when coupled with reflection absorption infrared (RAIR) and temperature programmed desorption (TPD) spectroscopies, diverse chemical and physical properties of molecular species at surfaces could be derived. These experiments have to be performed at cryogenic temperatures and at ultra high vacuum conditions without the possibility of collisions of neutrals and background deposition in view of the poor ion intensities and consequent need for longer exposure times. Here we combine a highly optimized low energy ion optical system designed for such studies coupled with RAIR and TPD and its initial characterization. Despite the ultralow collision energies and long ion path lengths employed, the ion intensities at 1 eV have been significant to collect a scattered ion spectrum of 1000 counts/s for mass selected CH2(+).