Characterization of dentine to assess bond strength of dental composites

This study was performed to develop alternating dentine adhesion models that could help in the evaluation of a self-bonding dental composite. For this purpose dentine from human and ivory was characterized chemically and microscopically before and after acid etching using Raman and SEM. Mechanical properties of dentine were determined using 3 point bend test. Composite bonding to dentine, with and without use of acid pre-treatment and/or the adhesive, were assessed using a shear bond test. Furthermore, micro gap formation after restoration of 3 mm diameter cavities in dentine was assessed by SEM. Initial hydroxyapatite level in ivory was half that in human dentine. Surface hydroxyapatites decreased by approximately half with every 23 s of acid etch. The human dentine strength (56 MPa) was approximately double that of ivory, while the modulus was almost comparable to that of ivory. With adhesive use, average shear bond strengths were 30 and 26 MPa with and without acid etching. With no adhesive, average bond strength was 6 MPa for conventional composites. This, however, increased to 14 MPa with a commercial flowable "self-bonding" composite or upon addition of low levels of an acidic monomer to the experimental composite. The acidic monomer additionally reduced micro-gap formation with the experimental composite. Improved bonding and mechanical properties should reduce composite failures due to recurrent caries or fracture respectively

Pandemic Pivot: A Faculty Development Program for Enhanced Remote Teaching

The novel coronavirus COVID-19 has impacted the higher education sector all over the world and has been most disruptive to residential academic institutions that offer mostly, if not wholly, in-person instruction. Of the 1.5 million college faculty members in the United States, about 70% had never taught a virtual course prior to COVID-19 (Hechinger & Lorin, 2020). During spring 2020, colleges had to pivot to remote instruction without much notice for faculty or students to prepare. Some referred to this as “emergency remote teaching” as it did not allow adequate time to thoughtfully plan out a course for a remote format (Hodges, et al., 2020). Institutions turned to web conferencing platforms such as Zoom to allow students and faculty to meet in real time and replicate the face-to-face experience as closely as possible, with mixed results. For some, it offered a space for class connection during a time of isolation from campus. Others experienced Zoom fatigue. Over the summer and fall of 2020, many colleges invested in training programs to help faculty design and deliver their courses in a remote format, beyond just using Zoom (Johnson, 2020). This article describes an online faculty development program that was created for faculty at a residential liberal arts university that, prior to COVID-19, offered the majority of courses on campus in-person. The objective of the program was to help faculty plan out and design their remote courses in the Blackboard Learning Management System using an instructional design framework known as backward design. This program ended up receiving the 2021 Blackboard Catalyst Award for Training and Professional Development

Extension of multifactor dimensionality reduction for identifying multilocus effects in the GAW14 simulated data

The multifactor dimensionality reduction (MDR) is a model-free approach that can identify gene × gene or gene × environment effects in a case-control study. Here we explore several modifications of the MDR method. We extended MDR to provide model selection without crossvalidation, and use a chi-square statistic as an alternative to prediction error (PE). We also modified the permutation test to provide different levels of stringency. The extended MDR (EMDR) includes three permutation tests (fixed, non-fixed, and omnibus) to obtain p-values of multilocus models. The goal of this study was to compare the different approaches implemented in the EMDR method and evaluate the ability to identify genetic effects in the Genetic Analysis Workshop 14 simulated data. We used three replicates from the simulated family data, generating matched pairs from family triads. The results showed: 1) chi-square and PE statistics give nearly consistent results; 2) results of EMDR without cross-validation matched that of EMDR with 10-fold cross-validation; 3) the fixed permutation test reports false-positive results in data from loci unrelated to the disease, but the non-fixed and omnibus permutation tests perform well in preventing false positives, with the omnibus test being the most conservative. We conclude that the non-cross-validation test can provide accurate results with the advantage of high efficiency compared to 10-cross-validation, and the non-fixed permutation test provides a good compromise between power and false-positive rate

A combined "electrochemical-frustrated Lewis pair" approach to hydrogen activation: surface catalytic effects at platinum electrodes

Herein, we extend our “combined electrochemical–frustrated Lewis pair” approach to include Pt electrode surfaces for the first time. We found that the voltammetric response of an electrochemical–frustrated Lewis pair (FLP) system involving the B(C6F5)3/[HB(C6F5)3]− redox couple exhibits a strong surface electrocatalytic effect at Pt electrodes. Using a combination of kinetic competition studies in the presence of a H atom scavenger, 6-bromohexene, and by changing the steric bulk of the Lewis acid borane catalyst from B(C6F5)3 to B(C6Cl5)3, the mechanism of electrochemical–FLP reactions on Pt surfaces was shown to be dominated by hydrogen-atom transfer (HAT) between Pt, [Pt[BOND]H] adatoms and transient [HB(C6F5)3]⋅ electrooxidation intermediates. These findings provide further insight into this new area of combining electrochemical and FLP reactions, and proffers additional avenues for exploration beyond energy generation, such as in electrosynthesis

Surrogacy Among Filipinos Who Have Struggled With Infertility: A Discourse Analysis

Surrogacy continues to be practiced to address infertility in the Philippines; however, discussions on the method are sparse, given its limited accessibility and morally questionable procedures that may concern potential parents in a developing country. Using discourse analysis, the researchers interviewed ten (10) Filipino Roman Catholics who were struggling with infertility, to uncover how they construct the idea of surrogacy. The study shows the discourses on surrogacy are often approached in a detached manner, where potential parents describe the method as a last choice or one that is never considered. They articulate this position by highlighting the emotional factors surrogacy would entail; the women, in particular, described the involvement of another individual as “taking over” the role of the mother. Participants placed themselves in positions of both power and vulnerability, reconciling the split between surrogacy as a compassionate act or a transactional business. The ambiguous role of faith was also negotiated by the participants, where they argued for surrogacy using alternative teachings or through God-given “free will”. The discourses present considerations for the continued practice of surrogacy among key players in reproductive health in developing countries, recognizing the concerns of infertile couples to enable informed decision-making and policy creation

Aurintricarboxylic Acid is a Canonical Disruptor of the TAZ-TEAD Transcriptional Complex

Disrupting the formation of the oncogenic YAP/TAZ-TEAD transcriptional complex holds substantial therapeutic potential. However, the three protein interaction interfaces of this complex cannot be easily disrupted using small molecules. Here, we report that the pharmacologically active small molecule aurintricarboxylic acid (ATA) acts as a disruptor of the TAZ-TEAD complex. ATA was identified in a high-throughput screen using a TAZ-TEAD AlphaLISA assay that was tailored to identify disruptors of this transcriptional complex. We further used fluorescence polarization assays both to confirm disruption of the TAZ-TEAD complex and to demonstrate that ATA binds to interface 3. We have previously shown that cell-based models that express the oncogenic TAZ-CAMTA1 (TC) fusion protein display enhanced TEAD transcriptional activity because TC functions as an activated form of TAZ. Utilizing cell-based studies and our TC model system, we performed TC/TEAD reporter, RNA-Seq, and qPCR assays and found that ATA inhibits TC/TEAD transcriptional activity. Further, disruption of TC/TEAD and TAZ/TEAD interaction by ATA abrogated anchorage-independent growth, the phenotype most closely linked to dysregulated TAZ/TEAD activity. Therefore, this study demonstrates that ATA is a novel small molecule that has the ability to disrupt the undruggable TAZ-TEAD interface