Coherence in Polycrystalline Thin Films of Twisted Molecular Crystals.

Helicoidal crystallites in rhythmically banded spherulites manifest spectacular optical patterns in small molecules and polymers. It is shown that concentric optical bands indicating crystallographic orientations typically lose coherence (in-phase twisting) with growth from the center of nucleation. Here, coherence is shown to increase as the twist period decreases for seven molecular crystals grown from the melt. This dependence was correlated to crystallite fiber thickness and length, as well as crystallite branching frequency, a parameter that was extracted from scanning electron micrographs, and supported by numerical simulations. Hole mobilities for 2,5-didodecyl-3,6-di(thiophen-2-yl)pyrrolo[3,4-c]pyrrole-1,4(2H,5H)-dione (DPP-C12) measured by using organic field-effect transistors demonstrated that more incoherent boundaries between optical bands in spherulites lead to higher charge transport for films with the same twist period. This was rationalized by combining our growth model with electrodynamic simulations. This work illustrates the emergence of complexity in crystallization processes (spherulite formation) that arises in the extra variable of helicoidal radial twisting. The details of the patterns analyzed here link the added complexity in crystal growth to the electronic and optical properties of the thin films.

Leveling up Organic Semiconductors with Crystal Twisting.

The performance of crystalline organic semiconductors depends on the solid-state structure, especially the orientation of the conjugated components with respect to device platforms. Often, crystals can be engineered by modifying chromophore substituents through synthesis. Meanwhile, dissymetry is necessary for high-tech applications like chiral sensing, optical telecommunications, and data storage. The synthesis of dissymmetric molecules is a labor-intensive exercise that might be undermined because common processing methods offer little control over orientation. Crystal twisting has emerged as a generalizable method for processing organic semiconductors and offers unique advantages, such as patterning of physical and chemical properties and chirality that arises from mesoscale twisting. The precession of crystal orientations can enrich performance because achiral molecules in achiral space groups suddenly become candidates for the aforementioned technologies that require dissymetry.

Scaffold-Guided Crystallization of Oriented α-FAPbI3 Nanowire Arrays for Solar Cells.

Perovskite nanowire arrays with large surface areas for efficient charge transfer and continuous highly crystalline domains for efficient charge transport exhibit ideal morphologies for solar-cell active layers. Here, we introduce a room temperature two-step method to grow dense, vertical nanowire arrays of formamidinium lead iodide (FAPbI3). PbI2 nanocrystals embedded in the cylindrical nanopores of anodized titanium dioxide scaffolds were converted to FAPbI3 by immersion in a FAI solution for a period of 0.5-30 min. During immersion, FAPbI3 crystals grew vertically from the scaffold surface as nanowires with diameters and densities determined by the underlying scaffold. The presence of butylammonium cations during nanowire growth stabilized the active α polymorph of FAPbI3, precluding the need for a thermal annealing step. Solar cells comprising α-FAPbI3 nanowire arrays exhibited maximum solar conversion efficiencies of >14%. Short-circuit current densities of 22-23 mA cm-2 were achieved, on par with those recorded for the best-performing FAPbI3 solar cells reported to date. Such large photocurrents are attributed to the single-crystalline, low-defect nature of the nanowires and increased interfacial area for photogenerated charge transfer compared with thin films.

Self-Patterning Tetrathiafulvalene Crystalline Films.

Tetrathiafulvalene (TTF) crystals grown from the melt are organized as spherulites in which helicoidal fibrils growing radially from the nucleation center twist in concert with one another. Alternating bright and dark concentric bands are apparent when films are viewed between crossed polarizers, indicating an alternating pattern of crystallographic faces exposed at the film surface. Band-dependent reorganization of the TTF crystals was observed during exposure to methanol vapor. Crystalline growth appears on bright bands at the expense of the dark bands. After a 24 h period of exposure to methanol vapor, the original spherulites were completely restructured, and the films comprise isolated, concentric circles of crystallites whose orientations are determined by the initial TTF crystal fibril orientation. While the surface of these outgrowths appears faceted and smooth, cross-sectional SEM images revealed a semiporous inner structure, suggesting solvent-vapor-induced recrystallization. Collectively, these results show that crystal twisting can be used to rhythmically redistribute material. Crystal twisting is a common and often controllable phenomenon independent of molecular or crystal structure and therefore offers a generalizable path to spontaneous pattern formation in a wide range of materials.

Validating the biosocial model of borderline personality disorder: Findings from a longitudinal study.

This longitudinal study aimed to validate the biosocial theory of borderline personality disorder (BPD) by examining the transactional relationship between individual vulnerabilities and parental invalidation, and their links to BPD symptoms. We recruited a sample of 332 adolescents (mean age = 14.18 years; 58.3% female) residing in Singapore and administered self-report measures across three time-points (six months apart). Results from our path analytic model indicated that parental invalidation, impulsivity, and emotional vulnerability exhibited unique predictive associations with emotion dysregulation six months later. There was also a reciprocal prospective relationship between emotion regulation difficulties and BPD symptoms. Using random-intercepts cross-lagged panel models, we found partial evidence for a within-individual reciprocal relationship between parental invalidation and emotional vulnerability, and a unidirectional relationship of within-individual changes in impulsivity positively predicting changes in parental invalidation six months later. Overall, the study provided partial empirical support for the biosocial model in a Singaporean context.

Diagnosis and Management of Pediatric Chronic Hand Eczema: The PeDRA CACHES Survey.

BACKGROUND: Chronic hand eczema (CHE) significantly impacts quality of life. Published literature on pediatric CHE (P-CHE) in North America including knowledge on epidemiology and standard evaluation and management is limited. OBJECTIVE: Our objective was to assess diagnostic practices when evaluating patients with P-CHE in the US and Canada, produce data on therapeutic agent prescribing practices for the disorder, and lay the foundation for future studies. METHODS: We surveyed pediatric dermatologists to collect data on clinician and patient population demographics, diagnostic methods, therapeutic agent selection, among other statistics. From June 2021 to January 2022, a survey was distributed to members of the Pediatric Dermatology Research Alliance (PeDRA). RESULTS: Fifty PeDRA members responded stating that they would be interested in participating, and 21 surveys were completed. For patients with P-CHE, providers most often utilize the diagnoses of irritant contact dermatitis, allergic contact dermatitis, dyshidrotic hand eczema, and atopic dermatitis. Contact allergy patch testing and bacterial hand culture are the most used tests for workup. Nearly all utilize topical corticosteroids as first line therapy. Most responders report that they have treated fewer than six patients with systemic agents and prefer dupilumab as first-line systemic therapy. CONCLUSIONS: This is the first characterization of P-CHE among pediatric dermatologists in the United States and Canada. This assessment may prove useful in designing further investigations including prospective studies of P-CHE epidemiology, morphology, nomenclature, and management.

Pediatric chronic hand eczema: Epidemiology, clinical presentation, and management.

Chronic hand eczema (CHE) is persistent inflammatory dermatitis that may significantly affect the quality of life, with psychosocial effects, impact on school, work, and leisure activities, influence on socioeconomic status, and high health care costs. Pediatric-CHE (P-CHE) has a high prevalence yet has not been extensively studied in children and adolescents. There is minimal published data on P-CHE in North America, and no specific management guidelines. Limited prevalence data show broad ranges (0.9%-4.4%) in preschool and school children, with 1 study stating up to 10.0% 1-year prevalence for ages 16 to 19 years. Atopic dermatitis and allergic contact dermatitis appear important in the pathogenesis of this disease process, although there is limited pediatric data assessing disease associations and no standardized methodology for evaluating this disorder. Given the potential life-changing consequences of P-CHE, further research into this disease process is warranted to help generate best therapeutic practices and minimize this disease process' morbidity in adulthood.

Collimating the growth of twisted crystals of achiral compounds.

A great proportion of molecular crystals can be made to grow as twisted fibrils. Typically, this requires high crystallization driving forces that lead to spherulitic textures. Here, it is shown how micron size channels fabricated from poly(dimethylsiloxane) (PDMS) serve to collimate the circular polycrystalline growth fronts of optically banded spherulites of twisted crystals of three compounds, coumarin, 2,5-bis(3-dodecyl-2-thienyl)-thiazolo[5,4-d]thiazole, and tetrathiafulvalene. The relationships between helicoidal pitch, growth front coherence, and channel width are measured. As channels spill into open spaces, collimated crystals "diffract" via small angle branching. On the other hand, crystals grown together from separate channels whose bands are out of phase ultimately become a single in-phase bundle of fibrils by a cooperative mechanism yet unknown. The isolation of a single twist sense in individual channels is described. We forecast that such chiral molecular crystalline channels may function as chiral optical wave guides.

Examining the intergenerational transmission of parental invalidation: Extension of the biosocial model.

This study examined the intergenerational transmission of parental invalidation and whether parental difficulties in emotion regulation mediated the association between past experiences of invalidation and current invalidating parenting practices. We also aimed to investigate whether gender might influence the transmission of parental invalidation. We recruited a community sample of 293 dual-parent families (adolescent and their parents) based in Singapore. Parents and adolescents each completed measures of childhood invalidation, whereas parents additionally reported on their difficulties in emotion regulation. Results based on path analyses demonstrated that past parental invalidation experienced by fathers positively predicted current perceived invalidation by their children. The association between mothers' childhood invalidation and current invalidating practices was fully mediated by mothers' difficulties with emotion regulation. Further analyses revealed that parents' current invalidating behaviors were not predicted by their past experiences of paternal or maternal invalidation. These findings point to the importance of considering the family invalidating environment as a whole when examining the influence of past experienced parental invalidation on emotion regulation and invalidating behaviors of second-generation parents. Our study provides empirical support for the intergenerational transmission of parental invalidation and highlights the need to address childhood experiences of parental invalidation in parenting programs.

Variable Association of Physiologic Changes With Electrographic Seizure-Like Events in Infants Born Preterm.

OBJECTIVES: To determine the incidence of seizure-like events in a cohort of infants born preterm as well as the prevalence of associated vital sign changes (heart rate [HR], respiratory rate, and pulse oximetry [SpO2]). STUDY DESIGN: We performed prospective conventional video electroencephalogram monitoring on infants born at 23-30 weeks of gestational age during the first 4 postnatal days. For detected seizure-like events, simultaneously captured vital sign data were analyzed during the pre-event baseline and during the event. Significant vital sign changes were defined as HR or respiratory rate >±2 SD from the infant's own baseline physiologic mean, derived from a 10-minute interval before the seizure-like event. Significant change in SpO2 was defined as oxygen desaturation during the event with a mean SpO2 <88%. RESULTS: Our sample included 48 infants with median gestational age of 28 weeks (IQR 26-29) and birth weight of 1125 g (IQR 963-1265). Twelve (25%) infants had seizure-like discharges with a total of 201 events; 83% (10/12) of infants had vital sign changes during these events, and 50% (6/12) had significant vital sign changes during the majority of the seizure-like events. Concurrent HR changes occurred the most frequently. CONCLUSIONS: Individual infant variability was observed in the prevalence of concurrent vital sign changes with electroencephalographic seizure-like events. Physiologic changes associated with preterm electrographic seizure-like events should be investigated further as a potential biomarker to assess the clinical significance of such events in the preterm population.

Charge Transport in Twisted Organic Semiconductor Crystals of Modulated Pitch.

Many molecular crystals (approximately one third) grow as twisted, helicoidal ribbons from the melt, and this preponderance is even higher in restricted classes of materials, for instance, charge-transfer complexes. Previously, twisted crystallites of such complexes present an increase in carrier mobilities. Here, the effect of twisting on charge mobility is better analyzed for a monocomponent organic semiconductor, 2,5-bis(3-dodecyl-2-thienyl)-thiazolo[5,4-d]thiazole (BDT), that forms twisted crystals with varied helicoidal pitches and makes possible a correlation of twist strength with carrier mobility. Films are analyzed by X-ray scattering and Mueller matrix polarimetry to characterize the microscale organization of the polycrystalline ensembles. Carrier mobilities of organic field-effect transistors are five times higher when the crystals are grown with the smallest pitches (most twisted), compared to those with the largest pitches, along the fiber elongation direction. A tenfold increase is observed along the perpendicular direction. Simulation of electrical potential based on scanning electron microscopy images and density functional theory suggests that the twisting-enhanced mobility is mainly controlled by the fiber organization in the film. A greater number of tightly packed twisted fibers separated by numerous smaller gaps permit better charge transport over the film surface compared to fewer big crystallites separated by larger gaps.

Resources Required for Implementation of SARS-CoV-2 Screening in Massachusetts K-12 Public Schools in Winter/Spring 2021.

BACKGROUND: The financial costs and human resource requirements at the school and district level to implement a SARS-CoV-2 screening program are not well known. METHODS: A consortium of Massachusetts public K-12 schools was formed to implement and evaluate a range of SARS-CoV-2 screening approaches. Participating districts were surveyed weekly about their programs, including: type of assay used, individual vs. pooled screening, approaches to return of results and deconvolution of positive pools, number and type of personnel, and hours spent implementing the screening program, and hours spent on program implementation. RESULTS: In 21 participating districts, over 21 weeks from January to June 2021, the positivity rate was 0.0% to 0.21% among students and 0.0% to 0.13% among educators/staff. The average weekly cost to implement a screening program, including assay and personnel costs, was $17.00 per person tested; this was $46.68 for individual screenings and $15.61 for pooled screenings. The total weekly costs by district ranged from $1,644 to $93,486, and districts screened between 58 and 3675 people per week. CONCLUSIONS: Where screening is recommended for the 2021 to 2022 school year due to high COVID-19 incidence, understanding the human resources and finances required to implement screening will assist district policymakers in planning.

Parental invalidation and its associations with borderline personality disorder symptoms: A multivariate meta-analysis.

Childhood invalidation has been postulated to be implicated in the development of borderline personality disorder (BPD), according to the biosocial model. Despite its significance, most systematic reviews and meta-analyses have focused on examining the associations between extreme forms of invalidation, such as sexual abuse, and BPD. Nonetheless, individuals could experience mild-to-severe levels of parental invalidation, with or without abuse. This study examined the relationship between parental invalidation as an overall construct and BPD symptoms, synthesized across 21 studies (total N = 7,198). As most reviewed studies utilized retrospective self-report measures, the effect sizes derived pertained largely to the association between reported childhood parental invalidation and BPD symptoms. We conducted a multivariate meta-analysis to account for the dependence of multiple effect sizes obtained from a single study and to maintain precision in obtained effect sizes. Maternal, paternal, and overall parental invalidation were positively associated with BPD symptoms, with small-to-moderate effect sizes of .26, .23, and .25, respectively. The mean effect size of maternal invalidation was greater than that of paternal invalidation. We also investigated if the parental invalidation-BPD associations were moderated by child gender, age, and culture (degree of individualism). Only overall parental invalidation and BPD symptoms association was moderated by child's gender, with larger effect sizes found for samples with a greater proportion of males. Age and culture did not moderate the parental invalidation-BPD association. Risk of publication bias was low. Our findings provide support for the invalidating childhood environment component of the biosocial model. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Atypical keratosis pilaris-like lesions in a patient with Bethlem myopathy.

Bethlem myopathy is a collagen VI-related myopathy. Collagen VI is primarily not only associated with the extracellular matrix of skeletal muscle, but is also found in the skin, blood vessels, and other organs. Dermatologic findings described for Bethlem myopathy include follicular hyperkeratosis and abnormal scar formation, although clinical and histopathologic photographs remain elusive in the literature. We present a case of atypical keratosis pilaris-like follicular lesions in a patient with Bethlem myopathy and provide histopathologic correlation to better characterize the development of skin lesions in this rare neuromuscular disease.

How do patient-provider relationship continuity, gender, and language affect pediatric HPV vaccine acceptance?

Increasing human papillomavirus (HPV) vaccine uptake remains a challenge. We compared reasons for HPV vaccine acceptance between two Southern California pediatric clinics serving diverse populations: an academically affiliated resident clinic that offered little continuity of care (n = 53) and a private-practice clinic with well-established physician-patient relationships (n = 200). We found strong doctor recommendation and information dissemination about the importance of HPV vaccination were the most important drivers of acceptance across these distinct settings. The top-cited reasons for vaccine acceptance also varied by gender, language (English vs. Spanish), and clinic type. Findings point to the need for (1) robust provider education on vaccines, vaccine-preventable diseases, and vaccine hesitancy and (2) increased efforts to raise public awareness of the importance of HPV vaccination.

Nanoconfining solution-processed organic semiconductors for emerging optoelectronics.

Solution-processable organic materials for emerging electronics can generally be divided into two classes of semiconductors, organic small molecules and polymers. The theoretical thermodynamic limits of device performance are largely determined by the molecular structure of these compounds, and advances in synthetic routes have led to significant progress in charge mobilities and light conversion and light emission efficiencies over the past several decades. Still, the uncontrolled formation of out-of-equilibrium film microstructures and unfavorable polymorphs during rapid solution processing remains a critical bottleneck facing the commercialization of these materials. This tutorial review provides an overview of the use of nanoconfining scaffolds to impose order onto solution-processed semiconducting films to overcome this limitation. For organic semiconducting small molecules and polymers, which typically exhibit strong crystal growth and charge transport anisotropy along different crystallographic directions, nanoconfining crystallization within nanopores and nanogrooves can preferentially orient the fast charge transport direction of crystals with the direction of current flow in devices. Nanoconfinement can also stabilize high-performance metastable polymorphs by shifting their relative Gibbs free energies via increasing the surface area-to-volume ratio. Promisingly, such nanoconfinement-induced improvements in film and crystal structures have been demonstrated to enhance the performance and stability of emerging optoelectronics that will enable large-scale manufacturing of flexible, lightweight displays and solar cells.

Management of Severe Atopic Dermatitis in Pediatric Patients.

Atopic dermatitis is a common, chronic inflammatory skin disorder, present in about 12% of children worldwide. Optimizing management of severe atopic dermatitis in pediatric patients is critical to reduce signs of inflammation, alleviate pruritus and sleep disturbance, minimize the development and/or impact of comorbidities, and improve the patient and caregiver's quality of life. Evaluating the longitudinal severity of pediatric atopic dermatitis is an important component of measuring therapeutic response and long-term management, and is different in clinical practice versus clinical trials. This article describes when and how to use different treatments for pediatric patients with severe atopic dermatitis, including topical medications, phototherapy, and systemic medical therapies (traditional immunosuppressants, biologics, and small molecule inhibitors). It also provides recommendations useful in clinical practice for nonpharmacologic interventions for pediatric patients with severe atopic dermatitis.