Physical and mechanical properties of a dental resin adhesive containing hydrophobic chitin nanocrystals.

OBJECTIVES: In this paper we propose embedding natural fillers, such as pristine and functionalized chitin nanocrystals, into resin adhesives to produce photopolymerizable dental filled adhesives with enhanced biocompatibility, hydrophobicity, mechanical resistance, and anti-bacterial properties. METHODS: Chitin nanocrystals (ChNC) were functionalized with decanoyl chloride and methacrylic anhydride to produce ChNC-C10 and ChNC-MA, respectively. These hydrophobically functionalized chitin nanocrystals were incorporated into a resin adhesive at concentrations of 0.5-3.0 wt% to assess the materials' physical and mechanical properties through Fourier-transform infrared (FTIR) spectroscopy, solid-state NMR spectroscopy, X-ray diffraction (XRD), elemental analysis, scanning electron microscopy (SEM), thermogravimetric analysis (TGA), flexural strength, microhardness, and water sorption tests. RESULTS: The analytical techniques confirmed the successful preparation of chitin nanocrystals from commercial chitin powder derived from shrimp shells and the efficient hydrophobization of their surface. Electron microscope images indicated that the increased hydrophobicity of ChNC-C10 promotes the formation of layered structures throughout the resin adhesive, while ChNC-MA tends to form aggregates in the matrix. Adhesives filled with ChNC-C10 enhanced their flexural strength, microhardness, and thermal stability and decreased their water sorption and degree of conversion. Adhesives filled with ChNC-MA resulted in improvements in microhardness, in water sorption and degree of conversion, although they did not exhibit augmentation of their flexural strength and thermal stability. SIGNIFICANCE: In light of the improved physical and mechanical properties with respect to the control, resin adhesives filled with anti-bacterial chitin nanocrystals are promising new materials for dental applications, especially those filled with low/moderate amounts of ChNC-C10.

Prostac: A New Composite Score With Potential Predictive Value in Prostate Cancer.

Prostate cancer (PCa) is the most commonly diagnosed solid organ cancer in men worldwide. Current diagnosis of PCa includes use of initial prostate specific antigen assay which has a high false positive rate, low specificity, and low sensitivity. The side effects of unnecessary prostate biopsies that healthy men are subjected to, often result in unintended health complications. New PCa biomarkers are being discovered to address this unmet need. Here, we report on the creation of a composite score (Prostac) based on three recently discovered PCa biomarkers, Plasmacytoma Variant Translocation 1 (PVT1) exons 4A, 4B, and 9. Statistical analysis of copy numbers derived from a real-time quantitative polymerase chain (qPCR) reaction - based assay, showed these PCa biomarkers to be linearly separable and significantly over expressed in PCa epithelial cells. We train a supervised learning algorithm using support vector machines to generate a classification hyperplane from which a user-friendly composite score is developed. Cross validation of Prostac using data from prostate epithelial cells (RWPE1) and PCa cells (MDA PCa 2b) accurately classified 100% of PCa cells. Creation of the Prostac score lays the groundwork for clinical trial of its use in PCa diagnosis.

Tailoring the Self-Healing Properties of Conducting Polymer Films.

The conducting polymer polyethylenedioxythiophene doped with polystyrene sulfonate (PEDOT:PSS) has received great attention in the field of wearable bioelectronics due to its tunable high electrical conductivity, air stability, ease of processability, biocompatibility, and recently discovered self-healing ability. It has been observed that blending additives with PEDOT:PSS or post-treatment permits the tailoring of intrinsic polymer properties, though their effects on the water-enabled self-healing property have not previously been established. Here, it is demonstrated that the water-enabled healing behavior of conducting polymers is decreased by crosslinkers or by acid post-treatment. Organic dopants of PEDOT have high water swelling ratios and lead to water-enabled healing, while inorganic dopants fail in the healing of PEDOT. The water-enabled healing of two isolated PEDOT:PSS squares with a 5 µm width gap and a thickness less than 1 µm is shown. This work will help pave the way for the further development of conducting polymer-based self-healable bioelectronics and flexible and stretchable electronics.

Persuasive Reminders for Health Self-Management.

Health reminders are integral to self-managing chronic illness. However, to act on these health reminders, patients face many challenges, such as lack of motivation and ability to perform health tasks. As a result, patients experience negative consequences for their health. To investigate the design of health reminders that persuade patients to take action, we conducted six participatory design sessions with two cohorts: mothers of children with asthma, and older adults with type 2 diabetes. Participants used collages, storyboards, and photos to express design ideas for future health reminder systems. From their design artifacts, we identified four types of persuasive reminders for health self-management: introspective, socially supportive, adaptive, and symbolic. We contribute insights into desired features for persuasive reminder systems from the perspectives of patients and informal caregivers, including features that support users to understand why and how to complete health tasks ahead of time, and affordances for intra-familial and patient-provider collaboration.

Designing Asynchronous Communication Tools for Optimization of Patient-Clinician Coordination.

Asynchronous communication outside the clinical setting has both enriched and complicated patient-clinician interactions. Many patients can now interact with a patient portal 24 hours a day, asking questions of their clinicians via secure message, checking lab results, ordering medication refills, or making appointments. However, the mode of communication (asynchronous) and the nature of the interaction (lacking tone or body language) strip valuable information from each side of patient-clinician asynchronous communication. Using interviews with 34 individuals who actively manage a chronic illness of their own, or for a child or partner, we elicited narratives about patients' experiences and expectations for using asynchronous communication to address medical issues with their clinicians. Based on these perspectives, we present opportunities for designing asynchronous communication tools to better facilitate understanding of and coordination around care activities between patients and clinicians.

Health Vlogs as Social Support for Chronic Illness Management.

Studies have shown positive impact of video blogs (vlogs) on patient education. However, we know little on how patient-initiated vlogs shape the relationships among vloggers and viewers. We qualitatively analyzed 72 vlogs on YouTube by users diagnosed with HIV, diabetes, or cancer and 1,274 comments posted to the vlogs to understand viewers' perspectives on the vlogs. We found that the unique video medium allowed intense and enriched personal and contextual disclosure to the viewers, leading to strong community-building activities and social support among vloggers and commenters, both informationally and emotionally. Furthermore, the unique communication structure of the vlogs allowed ad hoc small groups to form, which showed different group behavior than typical text-based social media, such as online communities. We provide implications to the Health Care Industry (HCI) community on how future technologies for health vlogs could be designed to further support chronic illness management.

Health Vlogger-Viewer Interaction in Chronic Illness Management.

Health video blogs (vlogs) allow individuals with chronic illnesses to share their stories, experiences, and knowledge with the general public. Furthermore, health vlogs help in creating a connection between the vlogger and the viewers. In this work, we present a qualitative study examining the various methods that health vloggers use to establish a connection with their viewers. We found that vloggers used genres to express specific messages to their viewers while using the uniqueness of video to establish a deeper connection with their viewers. Health vloggers also explicitly sought interaction with their viewers. Based on these results, we present design implications to help facilitate and build sustainable communities for vloggers.