Molecular imaging of experimental abdominal aortic aneurysms.

Current laboratory research in the field of abdominal aortic aneurysm (AAA) disease often utilizes small animal experimental models induced by genetic manipulation or chemical application. This has led to the use and development of multiple high-resolution molecular imaging modalities capable of tracking disease progression, quantifying the role of inflammation, and evaluating the effects of potential therapeutics. In vivo imaging reduces the number of research animals used, provides molecular and cellular information, and allows for longitudinal studies, a necessity when tracking vessel expansion in a single animal. This review outlines developments of both established and emerging molecular imaging techniques used to study AAA disease. Beyond the typical modalities used for anatomical imaging, which include ultrasound (US) and computed tomography (CT), previous molecular imaging efforts have used magnetic resonance (MR), near-infrared fluorescence (NIRF), bioluminescence, single-photon emission computed tomography (SPECT), and positron emission tomography (PET). Mouse and rat AAA models will hopefully provide insight into potential disease mechanisms, and the development of advanced molecular imaging techniques, if clinically useful, may have translational potential. These efforts could help improve the management of aneurysms and better evaluate the therapeutic potential of new treatments for human AAA disease.

Concept Mapping as a Metacognition Tool in a Problem-Solving-Based BME Course During In-Person and Online Instruction.

Metacognitive skills can have enormous benefits for students within engineering courses. Unfortunately, these metacognitive skills tend to fall outside the content area of most courses, and consequently, they can often be neglected in instruction. In this context, previous research on concept mapping as a teaching strategy points to meaningful learning. The purpose of this innovation paper is to report an application of concept mapping (1) to facilitate metacognition steps in students, and (2) to identify the muddiest points students struggle with, during both in-person and online instruction of a problem-solving-based biomedical engineering course. This innovation article also looks at the usefulness of concept mapping through instructor and student perceptions and students' class performance. The entire concept mapping intervention was conducted during weeks 8-10 of the Spring 2019 in-person quarter and during weeks 3-4 and 8-10 of the Spring 2021 online quarter. The exercise involved concept mapping, explanation and discussion with peers, and answering structured reflection prompts. Each concept map activity was contextualized to the metacognitive knowledge domain of the revised Bloom's taxonomy. The average class performance was compared between students who completed concept mapping vs. those who did not, using a t-test and one-way ANOVA at alpha = 0.05 significance level followed by a Tukey HSD test. Students' concept maps and reported answers were analyzed qualitatively following the concept mapping intervention. During the Spring 2019 in-person quarter, 59.30% of students completed concept mapping with reflection, whereas 47.67% completed it in spring 2021 online instruction. A two-tailed, unpaired t-test indicated that concept mapping did not significantly enhance students' class performance (p > 0.05) within each of the in-person and online instructions. Peers' suggestions to students to improve concept maps revealed themes related to course concepts, prerequisite concepts, and the act of concept mapping itself. Concept mapping was effective in revealing the muddiest points of the course. Concept mapping did not significantly enhance students' class performance either in-person or online instruction (effect sizes were 0.29 for the 2019 in-person quarter and 0.33 for the 2021 online quarter). However, instructors and students' perceptions reflected that concept mapping facilitated metacognition in a problem-solving-based biomedical engineering course both during in-person and online instruction. Most students (78%) were optimistic about the usefulness of concept mapping for this course, and 84% were inclined to apply it for a variety of other courses. Supplementary Information: The online version contains supplementary material available at 10.1007/s43683-022-00066-3.

Structuring Formative Feedback in an Online Graphics Design Course in BME.

With a motivation to immerse students in engineering design, graphics communication, and computer aided design (CAD) skills early-on in the biomedical engineering curriculum, we launched a new 2-unit laboratory course on "Graphics Design in BME" in the Spring 2020 quarter for UC Davis sophomores. Due to the COVID-19 pandemic, the course met with the significant challenge of conversion to an online mode of teaching, instead of planned face-to-face instruction. Providing formative feedback was thought to be an important step to help students succeed in their final CAD project of the course. In the process of designing feedback, we found that the concept of feedback is still fragile in an online learning environment because online learning settings provide distinct pedagogical demands as compared to face-to-face settings. The situation is especially delicate in the context of contemporary higher education imparting engineering skills, where students attend large classes, with diminished opportunities to interact with the teaching staff. The challenge we faced was to provide meaningful dialogic feedback in an online environment, especially while teaching engineering graphics design to a large class. Here we addressed this challenge by focusing on the process of structuring meaningful feedback. We designed a project assignment to be submitted as multiple deliverables to be submitted in two-stages. Then, we characterized its feedback with multiple notions, such as dialogic iterative cycles, personalized, goal-directed, immediate, in written format, and having a peer assessment component. The process of providing formative feedback online through the structure mentioned in this paper resulted in students' improved scores on the final project elements. It also helped us identify the common issues students are faltering in a graphics design class, and provide customized guidance, ideal examples of expected work, and more resources to motivate each student group to achieve mastery of course content. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s43683-021-00046-z.

Gender Differences During Toddlerhood in Autism Spectrum Disorder: A Prospective Community-Based Longitudinal Follow-Up Study.

Relatively few studies have examined gender differences in infants and toddlers, and most focus on clinically referred samples or high-risk infant cohorts. The current study aimed to examine gender differences in early autism manifestations and cognitive development in a community-ascertained sample. In total, 46 males and 21 females with ASD were seen at approximately 24 and 48 months of age. No significant gender differences were observed on overall cognitive ability, verbal skills, non-verbal skills, overall autism severity, or restricted repetitive behaviours. However, females were found to exhibit more social communication impairments than males. These findings may indicate that female toddlers with less severe or different, social communication impairments may be more likely to be missed during routine surveillance during toddlerhood.

ROS-responsive microspheres for on demand antioxidant therapy in a model of diabetic peripheral arterial disease.

A new microparticle-based delivery system was synthesized from reactive oxygen species (ROS)-responsive poly(propylene sulfide) (PPS) and tested for "on demand" antioxidant therapy. PPS is hydrophobic but undergoes a phase change to become hydrophilic upon oxidation and thus provides a useful platform for ROS-demanded drug release. This platform was tested for delivery of the promising anti-inflammatory and antioxidant therapeutic molecule curcumin, which is currently limited in use in its free form due to poor pharmacokinetic properties. PPS microspheres efficiently encapsulated curcumin through oil-in-water emulsion and provided sustained, on demand release that was modulated in vitro by hydrogen peroxide concentration. The cytocompatible, curcumin-loaded microspheres preferentially targeted and scavenged intracellular ROS in activated macrophages, reduced in vitro cell death in the presence of cytotoxic levels of ROS, and decreased tissue-level ROS in vivo in the diabetic mouse hind limb ischemia model of peripheral arterial disease. Interestingly, due to the ROS scavenging behavior of PPS, the blank microparticles also showed inherent therapeutic properties that were synergistic with the effects of curcumin in these assays. Functionally, local delivery of curcumin-PPS microspheres accelerated recovery from hind limb ischemia in diabetic mice, as demonstrated using non-invasive imaging techniques. This work demonstrates the potential for PPS microspheres as a generalizable vehicle for ROS-demanded drug release and establishes the utility of this platform for improving local curcumin bioavailability for treatment of chronic inflammatory diseases.

Dual pH- and temperature-responsive microparticles for protein delivery to ischemic tissues.

Injectable "smart" microspheres that are sensitive to both temperature and pH have been fabricated and tested for controlled delivery of therapeutic proteins to ischemic skeletal muscle. A library of copolymers composed of N-isopropyl acrylamide (NIPAAm), propyl acrylic acid (PAA), and butyl acrylate (BA) was used to fabricate microspheres using a double emulsion method, and an optimal formulation made from copolymers composed of 57 mol.% NIPAAm, 18 mol.% PAA and 25 mol.% BA copolymers was identified. At 37°C and pH representative of ischemic muscle (i.e. pH 5.2-7.2), these microspheres produced sustained, diffusion-controlled release, and at normal, physiological pH (i.e. pH 7.4), they underwent dissolution and rapid clearance. Delivery of fibroblast growth factor 2 was used to confirm that protein bioactivity was retained following microsphere encapsulation/release based on a dose-dependent increase in NIH3T3 fibroblast proliferation in vitro. Microsphere-loaded or free Cy5.5-labeled albumin was injected into ischemic and control gastrocnemii of mice following unilateral induction of hind limb ischemia to model peripheral arterial disease. In the ischemic limb at days 3.5 and 7, there was higher local retention of the protein delivered via microspheres relative to injected free protein (p<0.05). However, clearance of protein delivered via microspheres was equivalent to free protein at later time points that correspond to ischemic recovery in this model. Finally, histological analysis of the gastrocnemius revealed that the polymeric microspheres did not produce any microscopic signs of toxicity near the injection site. These combined results suggest that the pH- and temperature-responsive microspheres presented herein are a promising technological platform for controlled protein delivery to ischemic tissue.

GIS based water quality indexing of Malad creek, Mumbai (India): an impact of sewage discharges.

Malad creek is one of the most heavily polluted water bodies in Mumbai, India. Presently, creek receives wastewater and sewage from open drains and nallahs as well as partially treated wastewater from treatment facilities. The objective of the present study was to assess and classify the water quality zones spatially and temporally based on physico-chemical and bacteriological analysis. For this, GIS based methodology was integrated with water quality indexing, according to National Sanitation Foundation. Nine water quality parameters were considered to generate the indices that represent the overall status of creek water quality. Based on field observations and spatial distribution of water quality, various options were suggested for improvement in water quality of the creek.