Mandibular Gender Dimorphism: The Utility of Artificial Intelligence and Statistical Shape Modeling in Skeletal Facial Analysis.

BACKGROUND: In gender-affirming surgery, facial skeletal dimorphism is an important topic for every craniofacial surgeon. Few cephalometric studies have assessed this topic; however, they fall short to provide skeletal contour insights that direct surgical planning. Herein, we propose statistical shape modeling (SSM) as a novel tool for investigating mandibular dimorphism for young white individuals. METHODS: A single-center, retrospective study was performed using computed tomography (CT) scans of white individuals, aged 20 to 39 years old. AI-assisted, three-dimensional (3D) mandibles were reconstructed in Materialise Mimics v25.0. We used SSM to generate average 3D models for both genders. Relevant manual anthropometric measurements were taken for the SSMs and individual mandibles. Contour disparities were then represented using 3D overlays and heatmaps. Statistical analyses were performed using unpaired student t testing or Wilcoxon signed rank testing with 95% confidence interval as deemed appropriate by population-level normality assessment. RESULTS: Ninety-eight patients (53 females, 45 males) were included. Male mandibles showed greater bigonial width, intercondylar width, ramus height, and body length [p<0.005]. There was no statistically significant difference in the gonial angle measurements [p=0.62]. All relevant manual individual measurements demonstrated excellent concordance to their SSM counterparts. The 3D overlays of SSMs revealed squarer male chins with more lateral but less anterior projection than their female counterparts. Also, the female mandibles showed smoother transition at the gonial angle. CONCLUSIONS: SSM provides a novel tool to objectively evaluate volumetric and contour dimorphisms between genders. Moreover, this method can be automated, allowing for expedited comparisons between populations of interest compared to manual assessment. LEVEL OF EVIDENCE III: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors   www.springer.com/00266 . Bullet points about the importance of this work: Advancing Anthropometric Assessment: Statistical shape modeling (SSM) offers a cutting-edge approach to visualizing gender-specific skeletal anatomic differences for aesthetic and gender-affirming facial surgery. Expediting Comparative Analysis: The workflow established in this paper streamlines the evaluative process, enabling rapid morphologic comparisons between populations. Patient-Centered Care: This study establishes a foundation for the development of SSMs in individualized operative planning.

Virtual surgical planning and mirrored, 3-dimensionally printed guides for corrective clavicle osteotomies in clavicle malunions and nonunions.

BACKGROUND: The objective of this study was to retrospectively review clinical and radiographic outcomes of patients who underwent corrective osteotomies for clavicle malunion and internal fixation for nonunion using a combination of virtual surgical planning, patient-specific 3-dimensional (3D)-printed clavicles, and 3D-printed cutting guides manufactured at the point of care. METHODS: Between 2015 and 2021, 18 patients underwent corrective osteotomy for a clavicle malunion (7 shoulders) or internal fixation for a clavicle nonunion (11 shoulders). There were 11 male and 7 female individuals with an average patient age of 43.9 (range 19-76) years. All patients underwent computed tomography evaluation of both clavicles. The DICOM files were manually segmented, virtual surgical planning was performed selectively using commercially available software, and a mirrored version of the normal clavicle was 3D printed along with a 3D-printed replica of the affected clavicle. Three-dimensionally printed mirrored clavicles were used in all cases to ensure adequate restoration of the shape and length of the clavicle and to precontour fixation plates. Virtual surgical planning and 3D-printed cutting guides for osteotomy were used in 4 of 18 (22%) patients. Either cancellous or structural intercalary bone grafting was used in 15 of 18 (83%) cases. Patients were contacted postoperatively to determine clinical outcome scores. Preoperative, early postoperative, and late postoperative radiographs were reviewed to assess for union and complications. The average follow-up time was 24.9 months. RESULTS: Radiographic evaluation at the most recent follow-up demonstrated adequate restoration of length and successful union for all shoulders. There were no complications or reoperations. Postoperative patient-reported outcomes could be obtained in 16 of 18 (88.9%) patients. At the most recent follow-up, the mean visual analog scale for pain was 2.38 points (range, 1-7), the mean shoulder American Shoulder and Elbow Surgeons score was 73.2 points (range, 25-100), and the mean Patient-Reported Outcome Measurement Information System Upper Extremity score was 26 points (range, 7-35). All (100%) the patients were satisfied with their outcome (9 very satisfied, 7 satisfied), and their mean subjective shoulder value was 73% (range, 10%-100%). However, 2 patients complained of hardware-related symptoms, and 1 patient had return of preoperative symptoms after an interim 2 years of pain relief. CONCLUSION: The use of mirrored 3D-printed clavicles combined with virtual surgical planning and patient-specific 3D guides provides a reliable technique for restoring native anatomy when performing corrective osteotomies for clavicle malunion or internal fixation for clavicle nonunion, with a high rate of satisfactory clinical and radiographic outcomes.

Identification of bile acid and fatty acid species as candidate rapidly bactericidal agents for topical treatment of gonorrhoea.

BACKGROUND: Novel therapeutic strategies are urgently needed for Neisseria gonorrhoeae, given its increasing antimicrobial resistance. Treatment of oropharyngeal N. gonorrhoeae infections has proven particularly challenging, with most reported treatment failures of the first-line drug ceftriaxone occurring at this site and lower cure rates in recent trials of new antibiotics reported for oropharyngeal infections compared with other sites of infection. However, the accessibility of the oropharynx to topical therapeutics provides an opportunity for intervention. Local delivery of a therapeutic at a high concentration would enable the use of non-traditional antimicrobial candidates, including biological molecules that exploit underlying chemical sensitivities of N. gonorrhoeae but lack the potency or pharmacokinetic profiles required for effective systemic administration. METHODS: Two classes of molecules that are thought to limit gonococcal viability in vivo, bile acids and short- and medium-chain fatty acids, were examined for rapid bactericidal activity. RESULTS: The bile acids deoxycholic acid (DCA) and chenodeoxycholic acid (CDCA), but not other bile acid species, exerted extremely rapid bactericidal properties against N. gonorrhoeae, reducing viability more than 100 000-fold after 1 min. The short-chain fatty acids formic acid and hexanoic acid shared this rapid bactericidal activity. All four molecules are effective against a phylogenetically diverse panel of N. gonorrhoeae strains, including clinical isolates with upregulated efflux pumps and resistance alleles to the most widely used classes of existing antimicrobials. DCA and CDCA are both approved therapeutics for non-infectious indications and are well-tolerated by cultured epithelial cells. CONCLUSIONS: DCA and CDCA are attractive candidates for further development as anti-gonococcal agents.

Differential Impact of Blood Pressure Control Targets on Epicardial Coronary Flow After Transcatheter Aortic Valve Replacement.

Background: The cause for the association between increased cardiovascular mortality rates and lower blood pressure (BP) after aortic valve replacement (AVR) is unclear. This study aims to assess how the epicardial coronary flow (ECF) after AVR varies as BP levels are changed in the presence of a right coronary lesion. Methods: The hemodynamics of a 3D printed aortic root model with a SAPIEN 3 26 deployed were evaluated in an in vitro left heart simulator under a range of varying systolic blood pressure (SBP) and diastolic blood pressure (DBP). ECF and the flow ratio index were calculated. Flow index value <0.8 was considered a threshold for ischemia. Results: As SBP decreased, the average ECF decreased below the physiological coronary minimum at 120 mmHg. As DBP decreased, the average ECF was still maintained above the physiological minimum. The flow ratio index was >0.9 for SBP ≥130 mmHg. However, at an SBP of 120 mmHg, the flow ratio was 0.63 (p ≤ 0.0055). With decreasing DBP, no BP condition yielded a flow ratio index that was less than 0.91. Conclusions: Reducing BP to the current recommended levels assigned for the general population after AVR in the presence of coronary artery disease may require reconsideration of levels and treatment priority. Additional studies are needed to fully understand the changes in ECF dynamics after AVR in the presence and absence of coronary artery disease.

Hyoid Position and Aging: A Comprehensive Analysis Using AI-assisted Segmentation of 282 Computed Tomography Scans.

Background: With neck, aging the cervicomental angle becomes obtuse and may be influenced by hyoid bone aging. An understanding of hyoid position changes with aging will further our understanding of its role in neck contour changes. Methods: A 3D volumetric reconstruction of 282 neck computed tomography scans was performed. The cohort was categorized into three groups based on age: 20 years or older and younger than 40 years, 40 years or older and younger than 60 years, and 60 years or older and younger than 80 years. The vertical and horizontal hyoid distances in relation to the mandible were calculated for each patient. Results: A total of 282 patients (153 women, 129 men) were included in the cohort. The age groups were evenly distributed in men and women. Mean hyoid vertical and horizontal distances differed between women and men in all age groups. There was a significant difference in the hyoid vertical distance between 20-39 years old to 40-59 years old in men (P < 0.01), and 20-39 years old to 60-79 years old in both genders (women P = 0.005, men P < 0.01). Hyoid horizontal distance was not affected by age and sex (age and sex: P > 0.05), but rather by body mass index (BMI). Every 5 BMI points corresponded to a forward movement of 2 mm. Conclusions: As individuals age, the hyoid bone descends in both sexes, and an increase in BMI is associated with forward movement. Additional studies are needed to assess the correlation of the hyoid position between upright and supine positions.

Minibeam Radiation Therapy Treatment (MBRT): Commissioning and First Clinical Implementation.

PURPOSE: Minibeam radiation therapy (MBRT) is characterized by the delivery of submillimeter-wide regions of high "peak" and low "valley" doses throughout a tumor. Preclinical studies have long shown the promise of this technique, and we report here the first clinical implementation of MBRT. METHODS AND MATERIALS: A clinical orthovoltage unit was commissioned for MBRT patient treatments using 3-, 4-, 5-, 8-, and 10-cm diameter cones. The 180 kVp output was spatially separated into minibeams using a tungsten collimator with 0.5 mm wide slits spaced 1.1 mm on center. Percentage depth dose (PDD) measurements were obtained using film dosimetry and plastic water for both peak and valley doses. PDDs were measured on the central axis for offsets of 0, 0.5, and 1 cm. The peak-to-valley ratio was calculated at each depth for all cones and offsets. To mitigate the effects of patient motion on delivered dose, patient-specific 3-dimensional-printed collimator holders were created. These conformed to the unique anatomy of each patient and affixed the tungsten collimator directly to the body. Two patients were treated with MBRT; both received 2 fractions. RESULTS: Peak PDDs decreased gradually with depth. Valley PDDs initially increased slightly with depth, then decreased gradually beyond 2 cm. The peak-to-valley ratios were highest at the surface for smaller cone sizes and offsets. In vivo film dosimetry confirmed a distinct delineation of peak and valley doses in both patients treated with MBRT with no dose blurring. Both patients experienced prompt improvement in symptoms and tumor response. CONCLUSIONS: We report commissioning results, treatment processes, and the first 2 patients treated with MBRT using a clinical orthovoltage unit. While demonstrating the feasibility of this approach is a crucial first step toward wider translation, clinical trials are needed to further establish safety and efficacy.

Demographics, Utilization, Workflow, and Outcomes Based on Observational Data From the RSNA-ACR 3D Printing Registry.

PURPOSE: The aim of this study was to report data from the first 3 years of operation of the RSNA-ACR 3D Printing Registry. METHODS: Data from June 2020 to June 2023 were extracted, including demographics, indications, workflow, and user assessments. Clinical indications were stratified by 12 organ systems. Imaging modalities, printing technologies, and numbers of parts per case were assessed. Effort data were analyzed, dividing staff members into provider and nonprovider categories. The opinions of clinical users were evaluated using a Likert scale questionnaire, and estimates of procedure time saved were collected. RESULTS: A total of 20 sites and 2,637 cases were included, consisting of 1,863 anatomic models and 774 anatomic guides. Mean patient ages for models and guides were 42.4 ± 24.5 years and 56.3 ± 18.5 years, respectively. Cardiac models were the most common type of model (27.2%), and neurologic guides were the most common type of guide (42.4%). Material jetting, vat photopolymerization, and material extrusion were the most common printing technologies used overall (85.6% of all cases). On average, providers spent 92.4 min and nonproviders spent 335.0 min per case. Providers spent most time on consultation (33.6 min), while nonproviders focused most on segmentation (148.0 min). Confidence in treatment plans increased after using 3-D printing (P < .001). Estimated procedure time savings for 155 cases was 40.5 ± 26.1 min. CONCLUSIONS: Three-dimensional printing is performed at health care facilities for many clinical indications. The registry provides insight into the technologies and workflows used to create anatomic models and guides, and the data show clinical benefits from 3-D printing.

3D Printed Models of Trochlear Dysplasia and Trochleoplasty Simulation for Trainee Education.

Trochlear dysplasia is a major contributor to patellofemoral instability and subsequent failure of isolated soft tissue reconstruction procedures in the treatment of recurrent patellar dislocation and/or subluxation. Trochleoplasty procedures aim to address abnormal osseous trochlear morphologic factors that contribute to patellar maltracking. However, teaching these techniques is limited by the lack of reliable training models for trochlear dysplasia and trochleoplasty simulation. Although a cadaveric knee model of trochlear dysplasia for trochleoplasty simulation has been recently described, cadaveric knees are less amenable for use in trochleoplasty planning and surgeon training because of the absence of reliable, natural dysplastic anatomic relationships, such as suprapatellar spurs due to the rarity of dysplastic cadavers and the high cost of cadaveric specimens. Furthermore, readily available sawbone models represent "normal" osseous trochlear morphology and are difficult to modify and bend due to their material composition. Given this, we have developed a cost-effective, reliable, and anatomically accurate three-dimensional (3D) knee model of trochlear dysplasia for trochleoplasty simulation and trainee education.

Combined Lateral Closing and Medial Opening-Wedge Proximal Humerus Osteotomy in an Adolescent with Extreme Varus Deformity: A Case Report.

CASE: This report describes the case of an athletic 12-year-old boy who presented with a 64° left proximal humeral varus angulation deformity and physeal bar secondary to multiple operations for a proximal humeral metaphyseal cystic lesion and pathologic fracture. Using a combined lateral closing and medial opening-wedge osteotomy, a 68° valgus correction was achieved with excellent clinical and functional outcomes at 16-month follow-up. Forward flexion increased from 120 to 170° preoperatively to postoperatively while abduction improved from 110° preoperatively to 170° postoperatively. CONCLUSION: A combined lateral closing and medial opening-wedge osteotomy of the proximal humerus can successfully treat cases of extreme proximal humerus varus in the growing shoulder where unilateral or dome osteotomies are not suitable.

The Role of 3D Printing in Treatment Planning of Spine and Sacral Tumors.

Three-dimensional (3D) printing technology has proven to have many advantages in spine and sacrum surgery. 3D printing allows the manufacturing of life-size patient-specific anatomic and pathologic models to improve preoperative understanding of patient anatomy and pathology. Additionally, virtual surgical planning using medical computer-aided design software has enabled surgeons to create patient-specific surgical plans and simulate procedures in a virtual environment. This has resulted in reduced operative times, decreased complications, and improved patient outcomes. Combined with new surgical techniques, 3D-printed custom medical devices and instruments using titanium and biocompatible resins and polyamides have allowed innovative reconstructions.

Three-dimensional printing accuracy analysis for medical applications across a wide variety of printers.

Purpose: Three-dimensional (3D) printing has had a significant impact on patient care. However, there is a lack of standardization in quality assurance (QA) to ensure printing accuracy and precision given multiple printing technologies, variability across vendors, and inter-printer reliability issues. We investigated printing accuracy on a diverse selection of 3D printers commonly used in the medical field. Approach: A specially designed 3D printing QA phantom was periodically printed on 16 printers used in our practice, covering five distinct printing technologies and eight different vendors. Longitudinal data were acquired over six months by printing the QA phantom monthly on each printer. Qualitative assessment and quantitative measurements were obtained for each printed phantom. Accuracy and precision were assessed by comparing quantitative measurements with reference values of the phantom. Data were then compared among printer models, vendors, and printing technologies; longitudinal trends were also analyzed. Results: Differences in 3D printing accuracy across printers were observed. Material jetting and vat photopolymerization printers were found to be the most accurate. Printers using the same 3D printing technology but from different vendors also showed differences in accuracy, most notably between vat photopolymerization printers from two different vendors. Furthermore, differences in accuracy were found between printers from the same vendor using the same printing technology, but different models/generations. Conclusions: These results show how factors such as printing technology, vendor, and printer model can impact 3D printing accuracy, which should be appropriately considered in practice to avoid potential medical or surgical errors.

Enzyme-Triggered Intestine-Specific Targeting Adhesive Platform for Universal Oral Drug Delivery.

Patient adherence to chronic therapies can be suboptimal, leading to poor therapeutic outcomes. Dosage forms that enable reduction in dosing frequency stand to improve patient adherence. Variation in gastrointestinal transit time, inter-individual differences in gastrointestinal physiology and differences in physicochemical properties of drugs represent challenges to the development of such systems. To this end, a small intestine-targeted drug delivery system is developed, where prolonged gastrointestinal retention and sustained release are achieved through tissue adhesion of drug pills mediated by an essential intestinal enzyme catalase. Here proof-of-concept pharmacokinetics is demonstrated in the swine model for two drugs, hydrophilic amoxicillin and hydrophobic levodopa. It is anticipated that this system can be applicable for many drugs with a diverse of physicochemical characteristics.

Respirators in Healthcare: Material, Design, Regulatory, Environmental, and Economic Considerations for Clinical Efficacy.

Maintaining an ample supply of personal protective equipment continues to be a challenge for the healthcare industry, especially during emergency situations and times of strain on the supply chain. Most critically, healthcare workers exposed to potential airborne hazards require sufficient respiratory protection. Respirators are the only type of personal protective equipment able to provide adequate respiratory protection. However, their ability to shield hazards depends on design, material, proper fit, and environmental conditions. As a result, not all respirators may be adequate for all scenarios. Additionally, factors including user comfort, ease of use, and cost contribute to respirator effectiveness. Therefore, a careful consideration of these parameters is essential for ensuring respiratory protection for those working in the healthcare industry. Here respirator design and material characteristics are reviewed, as well as properties of airborne hazards and potential filtration mechanisms, regulatory standards of governmental agencies, respirator efficacy in the clinical setting, attitude of healthcare personnel toward respiratory protection, and environmental and economic considerations of respirator manufacturing and distribution.

Dynamic omnidirectional adhesive microneedle system for oral macromolecular drug delivery.

Oral drug administration remains the preferred route for patients and health care providers. Delivery of macromolecules through this route remains challenging because of limitations imposed by the transport across the gastrointestinal epithelium and the dynamic and degradative environment. Here, we present the development of a delivery system that combines physical (microneedle) and nonphysical (enhancer) modes of drug delivery enhancement for a macromolecule in a large animal model. Inspired by the thorny-headed intestinal worm, we report a dynamic omnidirectional mucoadhesive microneedle system capable of prolonged gastric mucosa fixation. Moreover, we incorporate sodium N-[8-(2-hydroxybenzoyl) amino] caprylate along with semaglutide and demonstrate enhanced absorption in swine resistant to physical displacement in the gastric cavity. Meanwhile, we developed a targeted capsule system capable of deploying intact microneedle-containing systems. These systems stand to enable the delivery of a range of drugs through the generation and maintenance of a privileged region in the gastrointestinal tract.

An automated all-in-one system for carbohydrate tracking, glucose monitoring, and insulin delivery.

Glycemic control through titration of insulin dosing remains the mainstay of diabetes mellitus treatment. Insulin therapy is generally divided into dosing with long- and short-acting insulin, where long-acting insulin provides basal coverage and short-acting insulin supports glycemic excursions associated with eating. The dosing of short-acting insulin often involves several steps for the user including blood glucose measurement and integration of potential carbohydrate loads to inform safe and appropriate dosing. The significant burden placed on the user for blood glucose measurement and effective carbohydrate counting can manifest in substantial effects on adherence. Through the application of computer vision, we have developed a smartphone-based system that is able to detect the carbohydrate load of food by simply taking a single image of the food and converting that information into a required insulin dose by incorporating a blood glucose measurement. Moreover, we report the development of comprehensive all-in-one insulin delivery systems that streamline all operations that peripheral devices require for safe insulin administration, which in turn significantly reduces the complexity and time required for titration of insulin. The development of an autonomous system that supports maximum ease and accuracy of insulin dosing will transform our ability to more effectively support patients with diabetes.

Biodegradable ring-shaped implantable device for intravesical therapy of bladder disorders.

Intravesical instillation is an efficient drug delivery route for the local treatment of various urological conditions. Nevertheless, intravesical instillation is associated with several challenges, including pain, urological infection, and frequent clinic visits for catheterization; these difficulties support the need for a simple and easy intravesical drug delivery platform. Here, we propose a novel biodegradable intravesical device capable of long-term, local drug delivery without a retrieval procedure. The intravesical device is composed of drug encapsulating biodegradable polycaprolactone (PCL) microcapsules and connected by a bioabsorbable Polydioxanone (PDS) suture with NdFeB magnets in the end. The device is easily inserted into the bladder and forms a 'ring' shape optimized for maximal mechanical stability as informed by finite element analysis. In this study, inserted devices were retained in a swine model for 4 weeks. Using this device, we evaluated the system's capacity for delivery of lidocaine and resiquimod and demonstrated prolonged drug release. Moreover, a cost-effectiveness analysis supports device implementation compared to the standard of care. Our data support that this device can be a versatile drug delivery platform for urologic medications.

Delivery of therapeutic carbon monoxide by gas-entrapping materials.

Carbon monoxide (CO) has long been considered a toxic gas but is now a recognized bioactive gasotransmitter with potent immunomodulatory effects. Although inhaled CO is currently under investigation for use in patients with lung disease, this mode of administration can present clinical challenges. The capacity to deliver CO directly and safely to the gastrointestinal (GI) tract could transform the management of diseases affecting the GI mucosa such as inflammatory bowel disease or radiation injury. To address this unmet need, inspired by molecular gastronomy techniques, we have developed a family of gas-entrapping materials (GEMs) for delivery of CO to the GI tract. We show highly tunable and potent delivery of CO, achieving clinically relevant CO concentrations in vivo in rodent and swine models. To support the potential range of applications of foam GEMs, we evaluated the system in three distinct disease models. We show that a GEM containing CO dose-dependently reduced acetaminophen-induced hepatocellular injury, dampened colitis-associated inflammation and oxidative tissue injury, and mitigated radiation-induced gut epithelial damage in rodents. Collectively, foam GEMs have potential paradigm-shifting implications for the safe therapeutic use of CO across a range of indications.

Thinking green: modelling respirator reuse strategies to reduce cost and waste.

OBJECTIVES: To compare the impact of respirator extended use and reuse strategies with regard to cost and sustainability during the COVID-19 pandemic. DESIGN: Cost analysis. SETTING: USA. PARTICIPANTS: All healthcare workers within the USA. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: A model was developed to estimate usage, costs and waste incurred by several respirator usage strategies over the first 6 months of the pandemic in the USA. This model assumed universal masking of all healthcare workers. Estimates were taken from the literature, government databases and commercially available data from approved vendors. RESULTS: A new N95 respirator per patient encounter would require 7.41 billion respirators, cost $6.38 billion and generate 84.0 million kg of waste in the USA over 6 months. One respirator per day per healthcare worker would require 3.29 billion respirators, cost $2.83 billion and generate 37.22 million kg of waste. Decontamination by ultraviolet germicidal irradiation would require 1.64 billion respirators, cost $1.41 billion and accumulate 18.61 million kg of waste. H2O2 vapour decontamination would require 1.15 billion respirators, cost $1.65 billion and produce 13.03 million kg of waste. One reusable respirator with daily disposable filters would require 18 million respirators, cost $1.24 billion and generate 15.73 million kg of waste. Pairing a reusable respirator with H2O2 vapour-decontaminated filters would reduce cost to $831 million and generate 1.58 million kg of waste. The use of one surgical mask per healthcare worker per day would require 3.29 billion masks, cost $460 million and generate 27.92 million kg of waste. CONCLUSIONS: Decontamination and reusable respirator-based strategies decreased the number of respirators used, costs and waste generated compared with single-use or daily extended-use of disposable respirators. Future development of low-cost,simple technologies to enable respirator and/or filter decontamination is needed to further minimise the economic and environmental costs of masks.

Patient and Health Care Worker Perceptions of Communication and Ability to Identify Emotion When Wearing Standard and Transparent Masks.

Importance: Adoption of mask wearing in response to the COVID-19 pandemic alters daily communication. Objective: To assess communication barriers associated with mask wearing in patient-clinician interactions and individuals who are deaf and hard of hearing. Design, Setting, and Participants: This pilot cross-sectional survey study included the general population, health care workers, and health care workers who are deaf or hard of hearing in the United States. Volunteers were sampled via an opt-in survey panel and nonrandomized convenience sampling. The general population survey was conducted between January 5 and January 8, 2021. The health care worker surveys were conducted between December 3, 2020, and January 3, 2021. Respondents viewed 2 short videos of a study author wearing both a standard and transparent N95 mask and answered questions regarding mask use, communication, preference, and fit. Surveys took 15 to 20 minutes to complete. Main Outcomes and Measures: Participants' perceptions were assessed surrounding the use of both mask types related to communication and the ability to express emotions. Results: The national survey consisted of 1000 participants (mean [SD] age, 48.7 [18.5] years; 496 [49.6%] women) with a response rate of 92.25%. The survey of general health care workers consisted of 123 participants (mean [SD] age, 49.5 [9.0] years; 84 [68.3%] women), with a response rate of 11.14%. The survey of health care workers who are deaf or hard of hearing consisted of 45 participants (mean [SD] age, 54.5 [9.0] years; 30 [66.7%] women) with a response rate of 23.95%. After viewing a video demonstrating a study author wearing a transparent N95 mask, 781 (78.1%) in the general population, 109 general health care workers (88.6%), and 38 health care workers who are deaf or hard of hearing (84.4%) were able to identify the emotion being expressed, in contrast with 201 (20.1%), 25 (20.5%), and 11 (24.4%) for the standard opaque N95 mask. In the general population, 450 (45.0%) felt positively about interacting with a health care worker wearing a transparent mask; 76 general health care workers (61.8%) and 37 health care workers who are deaf or hard of hearing (82.2%) felt positively about wearing a transparent mask to communicate with patients. Conclusions and Relevance: The findings of this study suggest that transparent masks could help improve communication during the COVID-19 pandemic, particularly for individuals who are deaf and hard of hearing.

Implantable system for chronotherapy.

Diurnal variation in enzymes, hormones, and other biological mediators has long been recognized in mammalian physiology. Developments in pharmacobiology over the past few decades have shown that timing drug delivery can enhance drug efficacy. Here, we report the development of a battery-free, refillable, subcutaneous, and trocar-compatible implantable system that facilitates chronotherapy by enabling tight control over the timing of drug administration in response to external mechanical actuation. The external wearable system is coupled to a mobile app to facilitate control over dosing time. Using this system, we show the efficacy of bromocriptine on glycemic control in a diabetic rat model. We also demonstrate that antihypertensives can be delivered through this device, which could have clinical applications given the recognized diurnal variation of hypertension-related complications. We anticipate that implants capable of chronotherapy will have a substantial impact on our capacity to enhance treatment effectiveness for a broad range of chronic conditions.