A theoretical characterization method for non-spherical core-shell nanoparticles by XPS.

Core-shell nanoparticles (NPs) are active research areas for their unique properties and wide applications. By changing the elemental composition in the core and shell, a series of core-shell NPs with specific functions can be obtained, where the sizes of the core and shell also influence the properties. X-ray photoelectron spectroscopy (XPS) is useful in this context as a means of quantitatively analyzing such NPs. The empirical formula proposed by Shard [J. Phys. Chem. C, 2012, 116(31), 16806-16813] for calculating the shell thickness of the spherical core-shell NPs has been verified by Powell et al. [J. Phys. Chem. C, 2016, 120(39), 22730-22738] through a simulation of XPS with Simulation of Electron Spectra for Surface Analysis (SESSA) software. However, real core-shell NPs are not necessarily ideal spheres; such NPs can have rich shapes and uneven thicknesses. This work aims to extend the Shard formula to non-ideal core-shell NPs. We have used a Monte Carlo simulation method to study the XPS signal variation with the shell thickness for several modeled non-spherical shapes of core-shell NPs including some complex geometric structures which are numerically constructed with finite-element triangular meshes. Five types of non-spherical shapes, i.e. egg, ellipsoid, rod, rough-surface, and star shapes, are considered, while the size parameters are varied over a wide range. The equivalent radius and equivalent thickness are defined to characterize the average size of the nanoparticles for the use of the Shard formula. We have thus derived an extended Shard formula for the specific core-shell NPs, with which the relative error between the predicted shell thickness and the real thickness can be reduced to less than 10%.

Capillary-driven horseshoe vortex forming around a micro-pillar.

HYPOTHESIS: Horseshoe vortices are known to emerge around large-scale obstacles, such as bridge pillars, due to an inertia-driven adverse pressure gradient forming on the upstream-side of the obstacle. We contend that a similar flow structure can arise in thin-film Stokes flow around micro-obstacles, such as used in textured surfaces to improve wettability. This could be exploited to enhance mixing in microfluidic devices, typically limited to creeping-flow regimes. EXPERIMENTS: Numerical simulations based on the Navier-Stokes equations are carried out to elucidate the flow structure associated with the wetting dynamics of a liquid film spreading around a 50 µm diameter micro-pillar. The employed multiphase solver, which is based on the volume of fluid method, accurately reproduces the wetting dynamics observed in current and previous (Mu et al., Langmuir, 2019) experiments. FINDINGS: The flow structure within the liquid meniscus forming at the foot of the micro-pillar evinces a horseshoe vortex wrapping around the obstacle, notwithstanding that the Reynolds number in our system is extremely low. Here, the adverse pressure gradient driving flow reversal near the bounding wall is caused by capillarity instead of inertia. The horseshoe vortex is entangled with other vortical structures, leading to an intricate flow system with high-potential mixing capabilities.

Thermoelectric instabilities in a circular Couette flow.

The stability of a non-isothermal circular Couette flow is analyzed when subjected to a dielectrophoretic force field. Outward and inward heating configurations are considered when the inner cylinder is rotating and the outer cylinder is at rest. In addition, an alternating voltage is applied between the two cylinders to induce a radial electric buoyancy that acts on the dielectric fluid. The linear stability analysis provides the threshold for the first transition to instability, as well as the corresponding wavenumber and frequency of the modes. This article is part of the theme issue 'Taylor-Couette and related flows on the centennial of Taylor's seminal Philosophical Transactions paper (part 1)'.

Effect of high- and low-energy entrance surface dose allocation ratio for two-shot dual-energy subtraction imaging on low-contrast resolution.

INTRODUCTION: Dual-energy subtraction (DES) imaging can obtain chest radiographs with high contrast between nodules and healthy lung tissue, and evaluating of chest radiography and evaluating exposure conditions is crucial to obtain a high-quality diagnostic image. This study aimed to investigate the effect of the dose allocation ratio of entrance surface dose (ESD) between high- and low-energy projection in low-contrast resolution of soft-tissue images for two-shot DES imaging in digital radiography using a contrast-detail phantom (CD phantom). METHODS: A custom-made phantom mimicking a human chest that combined a CD phantom, polymethylmethacrylate square plate, and an aluminum plate (1-3 mm) was used. The tube voltage was 120 kVp (high-energy) and 60 kVp (low-energy). The ESD was changed from 0.1 to 0.5 mGy in 0.1 mGy increments. Dose allocation ratio of ESD between 120 kVp and 60 kVp projection was set at 1:1, 1:2, 1:3, and 2:1. Inverse image quality figure (IQFinv) was calculated from the custom-made phantom images. RESULTS: When the total ESD and aluminum thickness were constant, no significant difference in IQFinv was observed under most conditions of varied dose allocation ratio. Similarly, when the total ESD and the dose allocation ratio were constant, there was no significant difference in IQFinv based on the aluminum plate thickness. CONCLUSION: Using IQFinv to evaluate the quality of the two-shot DES image suggested that dose allocation ratio did not have a significant effect on low-contrast resolution of soft-tissue images. IMPLICATIONS FOR PRACTICE: The present results provide useful information for determining exposure conditions for two-shot DES imaging.

Correction to: Comprehensive genetic analyses using targeted next-generation sequencing and genotype-phenotype correlations in 53 Japanese patients with osteogenesis imperfecta.

The original article has been corrected.

Plasmonic layer-selective all-optical switching of magnetization with nanometer resolution.

All-optical magnetization reversal with femtosecond laser pulses facilitates the fastest and least dissipative magnetic recording, but writing magnetic bits with spatial resolution better than the wavelength of light has so far been seen as a major challenge. Here, we demonstrate that a single femtosecond laser pulse of wavelength 800 nm can be used to toggle the magnetization exclusively within one of two 10-nm thick magnetic nanolayers, separated by just 80 nm, without affecting the other one. The choice of the addressed layer is enabled by the excitation of a plasmon-polariton at a targeted interface of the nanostructure, and realized merely by rotating the polarization-axis of the linearly-polarized ultrashort optical pulse by 90°. Our results unveil a robust tool that can be deployed to reliably switch magnetization in targeted nanolayers of heterostructures, and paves the way to increasing the storage density of opto-magnetic recording by a factor of at least 2.

Comprehensive genetic analyses using targeted next-generation sequencing and genotype-phenotype correlations in 53 Japanese patients with osteogenesis imperfecta.

To elucidate mutation spectrum and genotype-phenotype correlations in Japanese patients with OI, we conducted comprehensive genetic analyses using NGS, as this had not been analyzed comprehensively in this patient population. Most mutations were located on COL1A1 and COL1A2. Glycine substitutions in COL1A1 resulted in the severe phenotype. INTRODUCTION: Most cases of osteogenesis imperfecta (OI) are caused by mutations in COL1A1 or COL1A2, which encode α chains of type I collagen. However, mutations in at least 16 other genes also cause OI. The mutation spectrum in Japanese patients with OI has not been comprehensively analyzed, as it is difficult to identify using classical Sanger sequencing. In this study, we aimed to reveal the mutation spectrum and genotype-phenotype correlations in Japanese patients with OI using next-generation sequencing (NGS). METHODS: We designed a capture panel for sequencing 15 candidate OI genes and 19 candidate genes that are associated with bone fragility or Wnt signaling. Using NGS, we examined 53 Japanese patients with OI from unrelated families. RESULTS: Pathogenic mutations were detected in 43 out of 53 individuals. All mutations were heterozygous. Among the 43 individuals, 40 variants were identified including 15 novel mutations. We found these mutations in COL1A1 (n = 30, 69.8%), COL1A2 (n = 12, 27.9%), and IFITM5 (n = 1, 2.3%). Patients with glycine substitution on COL1A1 had a higher frequency of fractures and were more severely short-statured. Although no significant genotype-phenotype correlation was observed for bone mineral density, the trabecular bone score was significantly lower in patients with glycine substitutions. CONCLUSION: We identified pathogenic mutations in 81% of our Japanese patients with OI. Most mutations were located on COL1A1 and COL1A2. This study revealed that glycine substitutions on COL1A1 resulted in the severe phenotype among Japanese patients with OI.

Study of twice-weekly injections of Teriparatide by comparing efficacy with once-weekly injections in osteoporosis patients: the TWICE study.

A 48-week, multicenter, randomized, double-blind, double-dummy, active-controlled, non-inferiority trial (the TWICE study) conducted in Japanese primary osteoporosis patients with a high risk of fractures demonstrated that a 28.2-µg twice-weekly regimen of teriparatide can provide comparable efficacy to a 56.5-µg once-weekly regimen of teriparatide, while also improving safety. INTRODUCTION: While a 56.5-µg once-weekly regimen of teriparatide has high efficacy for osteoporosis, treatment continuation rates are low, with one of the major causes being adverse drug reactions such as nausea or vomiting. The TWICE study was therefore conducted to investigate whether a twice-weekly regimen with 28.2-µg teriparatide can provide comparable efficacy to the 56.5-µg once-weekly regimen while improving safety. METHODS: A 48-week, multicenter, randomized, double-blind, double-dummy, active-controlled, non-inferiority trial was conducted in Japan. Patients with primary osteoporosis aged ≥ 65 years at high risk of fractures (n = 553) were randomly allocated to the 28.2-µg twice-weekly group (n = 277) or the 56.5-µg once-weekly group (n = 276). The primary endpoint was the percentage change in lumbar spine (L2-L4) bone mineral density (BMD) at final follow-up. RESULTS: The percentage changes in lumbar spine (L2-L4) BMD at final follow-up in the 28.2-µg twice-weekly and 56.5-µg once-weekly groups were 7.3% and 5.9%, respectively; the difference (95% confidence interval [CI]) in percentage change was 1.3% (0.400-2.283%). Since the lower limit of the 95% CI was above the pre-specified non-inferiority margin (- 1.6%), non-inferiority of the 28.2-µg twice-weekly group was demonstrated. Adverse drug reactions were significantly less frequent in the 28.2-µg twice-weekly group (39.7% vs 56.2%; p < 0.01); the incidence of major adverse drug reactions was lower, and the number of subjects who discontinued due to adverse drug reactions was less in the 28.2-µg twice-weekly group. CONCLUSIONS: A 28.2-µg twice-weekly regimen of teriparatide can provide comparable efficacy to a 56.5-µg once-weekly regimen while improving safety. CLINICAL TRIAL REGISTRATION: JapicCTI-163477 .

Cartilage wear patterns in severe osteoarthritis of the trapeziometacarpal joint: a quantitative analysis.

OBJECTIVE: The present quantitative study aimed to assess the three-dimensional (3-D) cartilage wear patterns of the first metacarpal and trapezium in the advanced stage of osteoarthritis (OA) and compare cartilage measurements with radiographic severity. DESIGN: Using 19 cadaveric trapeziometacarpal (TMC) joints, 3-D cartilage surface models of the first metacarpal and trapezium were created with a laser scanner, and 3-D bone surface model counterparts were similarly created after dissolving the cartilage. These two models were superimposed, and the interval distance on the articular surface as the cartilage thickness was measured. All measurements were obtained in categorized anatomic regions on the articular surface of the respective bone, and we analyzed the 3-D wear patterns on the entire cartilage surface. Furthermore, we compared measurements of cartilage thickness with radiographic OA severity according to the Eaton grading system using Pearson correlation coefficients (r). RESULTS: In the first metacarpal, the cartilage thickness declined volarly (the mean cartilage thickness of the volar region was 0.32 ± 0.16 mm, whereas that of the dorsal region was 0.53 ± 0.18 mm). Conversely, the cartilage evenly degenerated throughout the articular surface of the trapezium. Measurements of the categorized regions where cartilage thinning was remarkable exhibited statistical correlations with radiographic staging (r = -0.48 to -0.72). CONCLUSIONS: Our findings indicate that cartilage wear patterns differ between the first metacarpal and trapezium in the late stage of OA. There is a need for further studies on cartilage degeneration leading to symptomatic OA in the TMC joint.

Safety of tooth extraction in patients receiving direct oral anticoagulant treatment versus warfarin: a prospective observation study.

The aim of this study was to compare the safety of tooth extraction in patients receiving direct oral anticoagulants (DOACs) or warfarin without cessation of their antithrombotic treatment. This prospective observational study included 367 patients undergoing tooth extraction (119 receiving DOACs and 248 receiving warfarin). All extractions in DOAC patients were performed 6-7h after taking DOACs in consideration of the half-life in blood under continued antithrombotic treatment. To examine the potential postoperative bleeding risk related to the time of extraction and the drug concentration of blood, activated partial thromboplastin time (APTT) in dabigatran and prothrombin time (PT) in rivaroxaban were measured three times after administration. A total of 390 tooth extractions were performed: 128 in the DOAC patients and 262 in warfarin patients. Postoperative bleeding occurred in four extractions (3.1%) in the DOAC group and in 23 (8.8%) in the warfarin group. There was no statistically significant difference between the two groups (odds ratio: 2.362, 95% confidence interval (CI) 0.819-6.815, p=0.112). APTT and PT prolongation in almost all cases decreased with time after taking the medicine. Our findings suggest that interruption of DOAC therapy is not necessary for tooth extraction if the procedure is performed at least 6h after the last dose.

Efficacy, Immunogenicity, and Safety of a 9-Valent Human Papillomavirus Vaccine: Subgroup Analysis of Participants From Asian Countries.

Background: A 9-valent human papillomavirus-6/11/16/18/31/33/45/52/58 (9vHPV) vaccine extends coverage to 5 next most common oncogenic types (31/33/45/52/58) in cervical cancer versus quadrivalent HPV (qHPV) vaccine. We describe efficacy, immunogenicity, and safety in Asian participants (India, Hong Kong, South Korea, Japan, Taiwan, and Thailand) from 2 international studies: a randomized, double-blinded, qHPV vaccine-controlled efficacy study (young women aged 16-26 years; NCT00543543; Study 001); and an immunogenicity study (girls and boys aged 9-15 years; NCT00943722; Study 002). Methods: Participants (N = 2519) were vaccinated at day 1 and months 2 and 6. Gynecological samples (Study 001 only) and serum were collected for HPV DNA and antibody assessments, respectively. Injection-site and systemic adverse events (AEs) were monitored. Data were analyzed by country and vaccination group. Results: 9vHPV vaccine prevented HPV-31/33/45/52/58-related persistent infection with 90.4%-100% efficacy across included countries. At month 7, ≥97.9% of participants seroconverted for each HPV type. Injection-site AEs occurred in 77.7%-83.1% and 81.9%-87.5% of qHPV and 9vHPV vaccine recipients in Study 001, respectively, and 62.4%-85.7% of girls/boys in Study 002; most were mild to moderate. Conclusions: The 9vHPV vaccine is efficacious, immunogenic, and well tolerated in Asian participants. Data support 9vHPV vaccination programs in Asia. Clinical Trials Registration: NCT00543543; NCT00943722.

Impact of switching oral bisphosphonates to denosumab or daily teriparatide on the progression of radiographic joint destruction in patients with biologic-naïve rheumatoid arthritis.

In biologic-naïve female RA patients, switching oral BPs to DMAb significantly reduced radiographic joint destruction compared to continuing oral BPs or switching to TPTD at 12 months, which were significantly associated with a decrease of a bone resorption marker at 6 months. INTRODUCTION: The aim of this study was to clarify the effects of switching oral bisphosphonates (BPs) to denosumab (DMAb) or daily teriparatide (TPTD) on the progression of radiographic joint destruction in patients with biologic-naïve rheumatoid arthritis (RA). METHODS: A retrospective, case-controlled study involving 90 female RA patients (mean age 68.2 years, 96.7% postmenopausal, disease activity score assessing 28 joints with CRP (DAS28-CRP) 2.4, methotrexate treatment 81.1%, prednisolone treatment 68.9%, and prior BP treatment 44.8 months), who were allocated depending on each patient's and physician's wishes, to (1) the BP-continue group (n = 30), (2) the switch-to-DMAb group (n = 30), or (3) the switch-to-TPTD group (n = 30), was conducted. Patients were retrospectively selected to minimize the difference of possible clinical backgrounds that may affect the joint destruction of RA. The primary endpoint was to clarify the change of the modified total Sharp score (mTSS) from baseline to 12 months. RESULTS: After 12 months, the mean changes of the modified Sharp erosion score were significantly lower in the switch-to-DMAb group (0.2 ± 0.1; mean ± standard error) than in the switch-to-TPTD group (1.3 ± 0.5; P < 0.05), and mTSS was significantly lower in the switch-to-DMAb group (0.3 ± 0.2) than in the BP-continue group (1.0 ± 0.3; P < 0.05) and the switch-to-TPTD group (1.7 ± 0.6; P < 0.05). The logistic regression analysis showed that mTSS changes were significantly associated with the percent changes of TRACP-5b at 6 months (ß = 0.30, 95% CI = 0.002-0.016; P < 0.01). CONCLUSIONS: Changes of systemic bone turnover induced by switching BPs to DMAb or TPTD may affect not only systemic bone mass, but also local joint destruction, and its clinical relevance should be considered comprehensively.

In vivo three-dimensional kinematics of normal knees during different high-flexion activities.

AIMS: In Asia and the Middle-East, people often flex their knees deeply in order to perform activities of daily living. The purpose of this study was to investigate the 3D kinematics of normal knees during high-flexion activities. Our hypothesis was that the femorotibial rotation, varus-valgus angle, translations, and kinematic pathway of normal knees during high-flexion activities, varied according to activity. MATERIALS AND METHODS: We investigated the in vivo kinematics of eight normal knees in four male volunteers (mean age 41.8 years; 37 to 53) using 2D and 3D registration technique, and modelled the knees with a computer aided design program. Each subject squatted, kneeled, and sat cross-legged. We evaluated the femoral rotation and varus-valgus angle relative to the tibia and anteroposterior translation of the medial and lateral side, using the transepicodylar axis as our femoral reference relative to the perpendicular projection on to the tibial plateau. This method evaluates the femur medially from what has elsewhere been described as the extension facet centre, and differs from the method classically applied. RESULTS: During squatting and kneeling, the knees displayed femoral external rotation. When sitting cross-legged, femurs displayed internal rotation from 10° to 100°. From 100°, femoral external rotation was observed. No significant difference in varus-valgus angle was seen between squatting and kneeling, whereas a varus position was observed from 140° when sitting cross-legged. The measure kinematic pathway using our methodology found during squatting a medial pivoting pattern from 0° to 40° and bicondylar rollback from 40° to 150°. During kneeling, a medial pivot pattern was evident. When sitting cross-legged, a lateral pivot pattern was seen from 0° to 100°, and a medial pivot pattern beyond 100°. CONCLUSION: The kinematics of normal knees during high flexion are variable according to activity. Nevertheless, our study was limited to a small number of male patients using a different technique to report the kinematics than previous publications. Accordingly, caution should be observed in generalizing our findings. Cite this article: Bone Joint J 2018;100-B:50-5.

An optical pickup enzyme-linked immunosorbent assay (ELISA) with a microfluidic disk.

We evaluated optical pickup ELISA with an original microfluidic disk that contains eight radially arranged channels, which enable semi-automatic sample loading and washing. This disk-shaped chip composed of acrylic plates was fabricated by CO2 laser machining and capture antibodies were immobilized in the channels. After the immunoreaction with antigens and enzyme-linked secondary antibodies, an enzyme-catalyzed nanoaggregation of o-phenylenediamine was detected by measuring the reflectivity change of a laser beam focused in the channel. The assay of C-reactive protein (CRP) was successfully performed in a short amount of time (approximately 20 min from CRP loading). The limit of detection was determined to be 2 ng mL-1, which is more sensitive as compared with conventional ELISA using microplates.

Altered bone density and stress distribution patterns in long-standing cubitus varus deformity and their effect during early osteoarthritis of the elbow.

OBJECTIVE: To quantify the bone density and stress distribution patterns in long-standing cubitus varus and clarify the effects of the deformity on bone density. DESIGN: We created three-dimensional computed tomography (CT) elbow models from 21 patients with long-standing cubitus varus deformities without advanced osteoarthritis (OA) and assessed the deformity by superimposing the affected humerus onto a mirror-image of the contralateral normal. Elbows were divided into 13 regions before measuring the bone density of each region and comparing the percentage of high-density volume (%HDV) between affected and normal sides. We constructed finite element models and quantitatively analyzed stress distribution. RESULTS: Average degrees of deformities were 20.1° of varus, 6.4° of extension, and 12.7° of internal rotation. The medial side of the affected humerus and ulna, Anteromedial trochlea (P < 0.001), Medial coronoid (P = 0.004), and Medial olecranon (P = 0.049) had significantly higher %HDVs than their normal counterparts. Conversely, %HDVs on the affected lateral side, Capitellum (P < 0.001), Anterolateral trochlea (P = 0.010), Posterolateral trochlea (P < 0.001), Lateral coronoid (P = 0.007), and Lateral olecranon (P < 0.001) were significantly lower than the normal side. The affected radial head %HDVs at Anterolateral and Posteromedial quadrants were high (P = 0.007) and low (P = 0.007), respectively. The bone density distribution coincided with stress distribution patterns revealed by finite element analysis (FEA), except in the lateral region influenced by forearm rotation. CONCLUSIONS: Repetitive stress on the medial elbow may alter bone density distribution patterns, probably presenting from early stage of OA.

Converging on child mental health - toward shared global action for child development.

We are a group of researchers and clinicians with collective experience in child survival, nutrition, cognitive and social development, and treatment of common mental conditions. We join together to welcome an expanded definition of child development to guide global approaches to child health and overall social development. We call for resolve to integrate maternal and child mental health with child health, nutrition, and development services and policies, and see this as fundamental to the health and sustainable development of societies. We suggest specific steps toward achieving this objective, with associated global organizational and resource commitments. In particular, we call for a Global Planning Summit to establish a much needed Global Alliance for Child Development and Mental Health in all Policies.

Are the triple surface plasmon resonances in Zn nanoparticles true?

It has been experimentally and numerically confirmed that zinc (Zn) nanoparticles (NPs) dispersed in silica exhibit two optical extinction peaks around ∼250 nm (1st peak) and ∼1050 nm (2nd peak), both of which were ascribed to surface plasmon resonances (SPRs) in the broad sense, i.e., the dual SPRs. Recently, Kuiri and Majhi (KM) observed the 3rd peak around ∼900 nm by calculations, and proposed the triple SPRs for Zn NPs without any experimental confirmation. This paper claims that the 3rd peak has never been observed in any experiments nor in any calculations except given by KM. They justified the triple resonances from an approximated SPR criterion, ε 1Zn(ω) + 2ε 1SiO2 (ω) = 0, which is not valid for non-idealized metals like Zn, because the imaginary part of the dielectric function ε 2Zn(ω) is not negligible. Instead, a rigorous SPR criterion predicts the dual resonances only. From comparisons with ab initio band calculations, the 1st and 2nd extinction peak are ascribed to resonantly enhanced inter-band transitions (so-called electronic resonance) and intra-band transitions (SPR in the narrow sense), respectively. Since either of the peaks arises from the resonant enhancement due to the dielectric function, both the peaks are regarded as SPRs in the broad sense, i.e. the dual SPRs.

Calculations of Electron Inelastic Mean Free Paths. XI. Data for Liquid Water for Energies from 50 eV to 30 keV.

We calculated electron inelastic mean free paths (IMFPs) for liquid water from its optical energy-loss function (ELF) for electron energies from 50 eV to 30 keV. These calculations were made with the relativistic full Penn algorithm (FPA) that has been used for previous IMFP and electron stopping-power calculations for many elemental solids. We also calculated IMFPs of water with three additional algorithms: the relativistic single-pole approximation (SPA), the relativistic simplified SPA, and the relativistic extended Mermin method. These calculations were made using the same optical ELF in order to assess any differences of the IMFPs arising from choice of the algorithm. We found good agreement among the IMFPs from the four algorithms for energies over 300 eV. For energies less than 100 eV, however, large differences became apparent. IMFPs from the relativistic TPP-2M equation for predicting IMFPs were in good agreement with IMFPs from the four algorithms for energies between 300 eV and 30 keV but there was poorer agreement for lower energies. We calculated values of the static structure factor as a function of momentum transfer from the FPA. The resulting values were in good agreement with results from first-principles calculations and with inelastic X-ray scattering spectroscopy experiments. We made comparisons of our IMFPs with earlier calculations from authors who had used different algorithms and different ELF data sets. IMFP differences could then be analyzed in terms of the algorithms and the data sets. Finally, we compared our IMFPs with measurements of IMFPs and of a related quantity, the effective attenuation length (EAL). There were large variations in the measured IMFPs and EALs (as well as their dependence on electron energy). Further measurements are therefore required to establish consistent data sets and for more detailed comparisons with calculated IMFPs.

Gay-Straight Alliances as settings to discuss health topics: individual and group factors associated with substance use, mental health, and sexual health discussions.

Sexual minority (e.g. lesbian, gay, bisexual, questioning; LGBQ) and gender minority (e.g. transgender) youth experience myriad health risks. Gay-Straight Alliances (GSAs) are school-based settings where they may have opportunities to discuss substance use, mental health, and sexual health issues in ways that are safe and tailored to their experiences. Attention to these topics in GSAs could aid in developing programming for these settings. Among 295 youth from 33 Massachusetts high-school GSAs (69% LGBQ, 68% cisgender female, 68% White, Mage = 16.06), we examined how often youth discussed these topics within their GSA and identified factors associated with having more of these discussions. Youth and GSAs as a whole varied in their frequency of discussing these topics. Youth who accessed more information/resources in the GSA and did more advocacy more frequently engaged in discussions around substance use, mental health and sexual health. Youth who reported greater victimization more often discussed substance use and mental health, but not sexual health. Finally, GSAs whose members collectively reported greater victimization more frequently discussed these topics. These findings can assist the development of health programming to be delivered within GSAs.

Costal cartilage transplantation for treatment of growth plate injury in a rabbit model.

OBJECTIVES: The purpose of this study is to evaluate the effects of allogenic costal cartilage transplantation on preventing bony bridge formation and angular deformities for the treatment of partial growth plate injury using a rabbit model. METHODS: An experimental model of partial growth injury was created by resecting the medial part of the proximal tibial growth plate in male six-week-old New Zealand White rabbits. The rabbits were divided into four groups: no surgery; no transplantation; bone wax transplantation; and allogenic costal cartilage transplantation. The angular deformities of the tibia and bony bridge were analysed using radiographs and microcomputed tomography, and the repair of the injured growth plate cartilage and bony bridge formation rate were histologically evaluated. RESULTS: On radiographic evaluation, the varus deformities in the costal cartilage group were significantly improved compared with the no transplantation group at four and eight weeks after operation and with the bone wax group at eight weeks after operation. Micro-computed tomography showed that the bony bridge formation was prevented in the bone wax and costal cartilage groups. Histological findings showed that the bony bridge formation in the bone wax and costal cartilage group was decreased. In addition, the growth plate was continuous and stained with safranin O and immunohistochemically stained for type II collagen. CONCLUSION: Transplantation of costal cartilage improved angular deformities and decreased bony bridge formation in the partial growth plate injury. Costal cartilage might be a suitable graft for the treatment of growth plate injury.