Climate of Transformation: Pursuing Carbon Neutrality and Economic Equity in San Francisco

San Francisco has enacted numerous policies in its efforts to achieve carbon neutrality. Stephanie Siehr outlines current initiatives and the work that still needs to be done to lower greenhouse gas emissions

Reported Sildenafil Side Effects in Pediatric Pulmonary Hypertension Patients

Background: Sildenafil, a phosphodiestase type 5 inhibitor, was approved in 2005 for the treatment of pulmonary arterial hypertension (PAH) in adults, and is commonly used off-label for pediatric patients. Little is known, however, about sildenafil’s side effects in this population.Methods: Single institution, longitudinal survey-based study performed in an outpatient pediatric cardiology clinic. Pediatric patients on sildenafil (alone or in combination with other PH therapies) completed questionnaires regarding frequency of vascular, gastrointestinal, neurologic and hematologic side effects. Results: Between January 2011 and May 2014, 66 pediatric patients with PH on sildenafil filled out 214 surveys, 32 patients (96 surveys) on monotherapy, and 43 patients (118 surveys) on sildenafil plus an endothelin receptor antagonist (bosentan or ambrisentan) and/or a prostacyclin (epoprostenol or treprostinil). Overall, 30% of respondents identified at least one side effect. For all patients on sildenafil, incidence of side effects by system was 37% gastrointestinal, 35% vascular and 22% neurologic. For patients on sildenafil monotherapy, incidence of side effects by system was 24% gastrointestinal, 21% vascular and 18% neurologic compared to patients on combination therapy who reported an incidence of 48% gastrointestinal, 45% vascular and 25% neurologic.Conclusion: Incidence of vascular, gastrointestinal and neurologic side effect in pediatric patients on sildenafil therapy for pulmonary arterial hypertension was 30%. Side effects were more common in patients on combination therapy with an endothelin receptor antagonist and/or prostacyclin than in patients on sildenafil monotherapy

Cellulose nanocrystal effect on crystallization kinetics and biological properties of electrospun polycaprolactone

Mechanical properties of tissue engineering nanofibrous scaffolds are of importance because they not only determine their ease of application, but also influence the environment for cell growth and proliferation. Cellulose nanocrystals (CNCs) are natural renewable nanoparticles that have been widely used for manipulating nanofibers' mechanical properties. In this article, cellulose nanoparticles were incorporated into poly(caprolactone) (PCL) solution, and composite nanofibers were produced. Ozawa-Flynn-Wall (OFW) methodology and X-ray diffraction were used to investigate the effect of CNC incorporation on PCL crystalline structure and its biological properties. Results showed that CNC incorporation up to 1 increases the crystallization activation energy and reduces the crystal volume, while these factors remain constant above this critical concentration. MTT assay and microscopic images of seeded cells on the nanofiber scaffolds indicated increased cell growth on the samples containing CNC. This behavior could be attributed to their greater hydrophilicity, which was confirmed using parallel exponential kinetics (PEK) model fitting to results obtained from dynamic vapor sorption (DVS) studies. Superior performance of CNC containing samples was also confirmed by in vivo implantation on full-thickness wounds. The wound area faded away more rapidly in these samples. H&E and Masson's trichrome staining showed better regeneration and more developed tissues in wounds treated with PCL-CNC1 nanofibers. © 202