An Oncoplastic Approach to Primary Pediatric Pterygomaxillary Osteosarcoma.

Osteosarcomas arising within the pterygomaxillary/infratemporal fossa region are rare among the pediatric population. Survival rates are most influenced by tumor resection with negative margins, which can be dependent on surgical accessibility of the tumor site. The pterygomaxillary/infratemporal fossa location poses several challenges to safe and adequate tumor resection, including proximity of the facial nerve and great vessels and scarring associated with traditional transfacial approaches. In this article, we present the case of a 6-year-old boy with an osteosarcoma of the left pterygomaxillary/infratemporal fossa region successfully managed with an "oncoplastic" approach, incorporating the use of CAD/CAM and mixed reality technologies.

Factors Associated With Control of Diabetes and Hypertension Among Patients Seen as Part of a Longitudinal Medical School Service-Learning Program From 2018-2019: An Exploratory Analysis.

Introduction The Florida International University (FIU) Green Family Neighborhood Health Education Learning Program (NeighborhoodHELP) in Miami-Dade County serves communities impacted by adverse social determinants of health. This study identified sociodemographic factors affecting control of diabetes and hypertension among NeighborhoodHELP patients. Methods This non-concurrent cohort study evaluated NeighborhoodHELP patients who received care at mobile health centers (MHCs) utilizing de-identified data extracted from the MHCs' clinical quality metrics data set for the 2018-2019 fiscal year. A total of 143 eligible adults with diabetes and 222 adults with hypertension were identified. Condition control was defined as blood pressure ≤ 130 mmHg (systolic) and ≤ 80 mmHg (diastolic) or hemoglobin A1c (HbA1c) ≤ 7% (diabetes). Association with age, gender, ethnicity, marital status, language, service area, income per-capita, and medical student assignment was explored using logistic regression. Results The model showed decreased diabetes control likelihood among Haitian-Creole speakers (OR: 0.13; 95% CI: 0.02-0.75). Odds of diabetes control were greater in two discrete areas serviced by the program, one known as Hippocrates (OR: 4.9; 95% CI: 1.23-19.37) and the other Semmelweis (OR: 3.71; 95% CI: 1.07-12.83). Income greater than $10,000 increased hypertension control likelihood (OR: 2.22; 95% CI: 1.03-4.8). Conclusions Among NeighborhoodHELP patients, geographic region and language impact diabetes control, while income affects hypertension control. Further research is warranted to identify the role of other factors.

Mechanochemical strengthening of a synthetic polymer in response to typically destructive shear forces.

High shear stresses are known to trigger destructive bond-scission reactions in polymers. Recent work has shown that the same shear forces can be used to accelerate non-destructive reactions in mechanophores along polymer backbones, and it is demonstrated here that such mechanochemical reactions can be used to strengthen a polymer subjected to otherwise destructive shear forces. Polybutadiene was functionalized with dibromocyclopropane mechanophores, whose mechanical activation generates allylic bromides that are crosslinked in situ by nucleophilic substitution reactions with carboxylates. The crosslinking is activated efficiently by shear forces both in solvated systems and in bulk materials, and the resulting covalent polymer networks possess moduli that are orders-of-magnitude greater than those of the unactivated polymers. These molecular-level responses and their impact on polymer properties have implications for the design of materials that, like biological materials, actively remodel locally as a function of their physical environment.

Bicyclo[3.2.0]heptane mechanophores for the non-scissile and photochemically reversible generation of reactive bis-enones.

Force-induced transformations of polymer-bound functionalities have the potential to produce a rich array of stress-responsive behavior. One area of particular interest is the activation of non-scissile mechanophores in which latent reactivity can be unveiled that, under the appropriate conditions, could lead to constructive bond formation in materials exposed to typically destructive stress. Here, the mechanical activation of a bicyclo[3.2.0]heptane (BCH) mechanophore is demonstrated via selective labeling of bis-enone products. BCH ring-opening produces large local elongation (>4 Å) and products that are reactive to conjugate additions under mild conditions. Subsequent photocyclization regenerates the initial BCH functionality, providing switchable structure and reactivity along the polymer backbone in response to stress and visible light.

Tension trapping of carbonyl ylides facilitated by a change in polymer backbone.

Epoxidized polybutadiene and epoxidized polynorbornene were subjected to pulsed ultrasound in the presence of small molecules capable of being trapped by carbonyl ylides. When epoxidized polybutadiene was sonicated, there was no observable small molecule addition to the polymer. Concurrently, no appreciable isomerization (cis to trans epoxide) was observed, indicating that the epoxide rings along the backbone are not mechanically active under the experimental conditions employed. In contrast, when epoxidized polynorbornene was subjected to the same conditions, both addition of ylide trapping reagents and net isomerization of cis to trans epoxide were observed. The results demonstrate the mechanical activity of epoxides, show that mechanophore activity is determined not only by the functional group but also the polymer backbone in which it is embedded, and facilitate a characterization of the reactivity of the ring-opened dialkyl epoxide.

Microstructure of Copolymers Formed by the Reagentless, Mechanochemical Remodeling of Homopolymers via Pulsed Ultrasound.

The high shear forces generated during the pulsed ultrasound of dilute polymer solutions lead to large tensile forces that are focused near the center of the polymer chain, but quantitative experimental evidence regarding the force distribution is rare. Here, pulsed ultrasound of quantitatively geminal-dihalocyclopropanated (gDHC) polybutadiene provides insights into the distribution. Pulsed ultrasound leads to the mechanochemical ring-opening of the gDHC mechanophore to a 2,3-dihaloalkene. The alkene product is then degraded through ozonolysis to leave behind only those stretches of the polymer that have not experienced large enough forces to be activated. Microstructural and molecular weight analysis reveals that the activated and unactivated regions of the polymer are continuous, indicating a smooth and monotonic force distribution from the midchain peak toward the polymer ends. When coupled to chain scission, the net process constitutes the rapid, specific, and reagentless conversion of a single homopolymer into block copolymers. Despite their compositional polydispersity, the sonicated polymers assemble into ordered lamellar phases that are characterized by small-angle X-ray scattering.