From maternal tending to adolescent befriending: The adolescent transition of social support.

Attachment theory holds that parental relationships have lifelong effects on offspring social lives. The tend-and-befriend hypothesis posits that female friendships among humans evolved as part of a primate-wide coping mechanism to mediate stress by relying on social support. Here we bridge developmental and evolutionary frameworks to examine adolescent girls' perception of their reliance on female friendship for social support, how perceptions of parental relationships affect peer relationships, and the extent to which parent and peer relationships buffer depressive symptoms. We predict perceived maternal relationship quality will be positively associated with close female friendships, and maternal relationships, paternal relationships, and female friendship will buffer depressive symptoms. Participants were adolescent girls from a summer science camp (N = 95). Participants filled out demographic information, social network surveys, the Parent-Adolescent Communication Scale, and the Center for Epidemiology Depression Scale. Data was analyzed with Pearson's correlations, t tests, and path analysis. Adolescent girls with few female friends, compared with girls who had more than two very close female friends, experienced more depressive symptoms (t = 3.382, p = .001, D = 0.784). Adolescent girls with few female friends experienced more depressive symptoms compared to girls with two or more very close female friends (t = 3.382, p = .001, D = 0.784). Stronger maternal and paternal relationships were associated with having more female friends (maternal: t = -3.213, p = .003, D = 0.837; paternal: t = -2.432; p = .017). In the path analysis model, only maternal relationship quality significantly predicted female friendship category (ß = .33, CR = 2.770, p < .006). Furthermore, participants with two or more very close female friends and higher paternal relationship quality had significantly fewer depressive symptoms (friends; ß = -.19, CR = -2.112, p = .035; paternal: ß = -.33, CR = -3.220, p < .001), and older participants had more depressive symptoms (ß = .17, CR = -1.931, p = .036). These results provide additional support for the tend-and-befriend hypothesis, suggesting that maternal tending sets the stage for close female friendships.

Secondary anchor targeted cell release.

Personalized medicine offers the promise of tailoring therapy to patients, based on their cellular biomarkers. To achieve this goal, cellular profiling systems are needed that can quickly and efficiently isolate specific cell types without disrupting cellular biomarkers. Here we describe the development of a unique platform that facilitates gentle cell capture via a secondary, surface-anchoring moiety, and cell release. The cellular capture system consists of a glass surface functionalized with APTES, d-desthiobiotin, and streptavidin. Biotinylated mCD11b and hIgG antibodies are used to capture mouse macrophages (RAW 264.7) and human breast cancer (MCF7-GFP) cell lines, respectively. The surface functionalization is optimized by altering assay components, such as streptavidin, d-desthiobiotin, and APTES, to achieve cell capture on 80% of the functionalized surface and cell release upon biotin treatment. We also demonstrate an ability to capture 50% of target cells within a dual-cell mixture. This engineering advancement is a critical step towards achieving cell isolation platforms for personalized medicine.

Characterization of polymeric microcapsules containing a low molecular weight peptide for controlled release.

A need exists to prolong the release of rapidly metabolized peptides of a low molecular weight, while delivering this peptide without environmental interference. Previous studies have used bovine serum albumin (BSA) as a model peptide to study release characteristics from alginate microcapsules. BSA is 66 kDa in size, while the peptide of interest here, connexin-43 carboxyl-terminus mimetic peptide (αCT1), is only 3.4 kDa. Such a change in size results in a much different set of release parameters. Our overall goal is a sustained release over a 24+ h period. Prolonged application of the peptide to a wound site to investigate therapeutic effects is ideal. As a result, a diffusion method using alginate microcapsules, along with the addition of poly-l-lysine and poly-l-ornithine, has been explored. We first aimed to establish and characterize our parameters through a set of parametric tests. Variations in polymer coating, change in pH, and changes in loading ratio have previously been shown to effect release using model compounds. Here we test specific changes in these parameters to show effects on the release of αCT1. Additionally, the microcapsules were attached to several biomaterials and surgical implants by ultraviolet cross-linking to study the effectiveness of attachment and delivery. Analysis and measurements using phase contrast microscopy, scanning electron microscopy, and atomic force microscopy were used to characterize changes in microcapsule morphology.

Learning Environments and Evidence-Based Practices in Bioengineering and Biomedical Engineering.

This paper provides a synopsis of discussions related to the Learning Environments track of the Fourth BME Education Summit held at Case Western Reserve University in Cleveland, Ohio in May 2019. This summit was organized by the Council of Chairs of Bioengineering and Biomedical Engineering, and participants included over 300 faculty members from 100+ accredited undergraduate programs. The Learning Environments track had six interactive workshops that provided facilitated discussion and provide recommendations in the areas of: (1) Authentic project/problem identification in clinical, industrial, and global settings, (2) Experiential problem/project-based learning within courses, (3) Experiential learning in co-curricular learning settings, (4) Team-based learning, (5) Teaching to reach a diverse classroom, and (6) innovative platforms and pedagogy. A summary of the findings, best practices and recommendations from each of the workshops is provided under separate headings below, and a list of resources is provided at the end of this paper.

Use of Virtual Reality to Educate Undergraduate Medical Students on Cardiac Peripheral and Collateral Circulation.

Many medical schools are looking to utilize virtual reality (VR); however, due to its novelty, we know little about how VR can be effectively used in medical education. This study evaluates a case-centered VR task that supported students with learning peripheral and collateral circulation, anatomical features that are not easily observed in cadavers. Data sources included a quiz, survey, and focus group. Based on quantitative and qualitative analyses, we support the claim that this activity was an effective use of VR and identify features that made it effective, which can guide other educators who are interested in developing VR activities.

Low-Complexity System and Algorithm for an Emergency Ventilator Sensor and Alarm.

In response to anticipated shortages of ventilators caused by the COVID-19 pandemic, many organizations have designed low-cost emergency ventilators. Many of these devices are pressure-cycled pneumatic ventilators, which are easy to produce but often do not include the sensing or alarm features found on commercial ventilators. This work reports a low-cost, easy-to-produce electronic sensor and alarm system for pressure-cycled ventilators that estimates clinically useful metrics such as pressure and respiratory rate and sounds an alarm when the ventilator malfunctions. A low-complexity signal processing algorithm uses a pair of nonlinear recursive envelope trackers to monitor the signal from an electronic pressure sensor connected to the patient airway. The algorithm, inspired by those used in hearing aids, requires little memory and performs only a few calculations on each sample so that it can run on nearly any microcontroller.

Emergency ventilator for COVID-19.

The COVID-19 pandemic disrupted the world in 2020 by spreading at unprecedented rates and causing tens of thousands of fatalities within a few months. The number of deaths dramatically increased in regions where the number of patients in need of hospital care exceeded the availability of care. Many COVID-19 patients experience Acute Respiratory Distress Syndrome (ARDS), a condition that can be treated with mechanical ventilation. In response to the need for mechanical ventilators, designed and tested an emergency ventilator (EV) that can control a patient's peak inspiratory pressure (PIP) and breathing rate, while keeping a positive end expiratory pressure (PEEP). This article describes the rapid design, prototyping, and testing of the EV. The development process was enabled by rapid design iterations using additive manufacturing (AM). In the initial design phase, iterations between design, AM, and testing enabled a working prototype within one week. The designs of the 16 different components of the ventilator were locked by additively manufacturing and testing a total of 283 parts having parametrically varied dimensions. In the second stage, AM was used to produce 75 functional prototypes to support engineering evaluation and animal testing. The devices were tested over more than two million cycles. We also developed an electronic monitoring system and with automatic alarm to provide for safe operation, along with training materials and user guides. The final designs are available online under a free license. The designs have been transferred to more than 70 organizations in 15 countries. This project demonstrates the potential for ultra-fast product design, engineering, and testing of medical devices needed for COVID-19 emergency response.

The medical emergency team as a safety net.

In the case of an 11-year-old boy with stable physiological parameters, the deterioration in condition was so sudden that only a rapid response system could ensure any chance of survival.

Synergistic effects of high molecular weight polyethylene oxide (PEO) and cationic cellulosic polymers on conditioning properties of hair care products [corrected].

A hair cleansing composition containing both high molecular weight PEO and cationic hydroxyethyl cellulose (HEC) was found to provide superior conditioning performance. Hair treated with a formulation containing both cationic HEC and high molecular weight PEO showed 30% better wet combing reduction than the formulation containing cationic HEC only. In conjunction with PEO, cationic HEC-dependent deposition of silicone oil and octyl methoxycinnamate (OMC) onto hair was enhanced 27% and 25%, respectively. When examined with a polarized microscope, the appearance of the polymer-surfactant complex (coacervate) of the diluted formation differed in the presence of PEO. In particular, the particle size of the coacervate in the formulation containing both PEO and cationic HEC was smaller. This result indicates PEO reduces the size of the deposition precipitate by preventing the coacervate from agglomerating. Surface analysis also showed that the presence of PEO in formulations containing cationic HEC deposited insoluble actives more evenly on the hair surface.

Design of a new non-sterile glove-dispensing unit to reduce touch-based contamination.

BACKGROUND: Despite best efforts by healthcare providers to sterilise their hands through hand washing prior to touching medical equipment and patients, bacteria are still present and can be spread through physical contact. We aimed to reduce the spread of touch-induced and airborne bacteria and virus spreading by using a touch-free glove-dispensing system that minimally exposes gloves in the box to air. METHOD: The team met multiple times to undertake early prototyping and present ideas for the design. We experimented with folding gloves in varying patterns, similar to facial tissuedispensing boxes, and tried several methods of opening/closing the glove box to determine the most effective way to access gloves with the least amount of physical contact. We considered the user experience and obtained user feedback after each design iteration. RESULTS: Ultimately, we decided on a vertically oriented box with optional holes for dispensing a glove on the side of the box or on the bottom by means of the pull-down drawer mechanism. This system will dispense a single glove at a time to the user with the option of using a pull-down drawer trigger to decrease the likelihood of physical contact with unused gloves. Both methods dispense a single glove. CONCLUSION: By reducing physical contact between the healthcare practitioner and the gloves, we are potentially reducing the spread of bacteria. This glove box design ensures that gloves are not exposed to the air in the clinic or hospital setting, thereby further reducing spread of airborne germs. This could assist in decreasing the risk of nosocomial infections in healthcare settings.

Limb bud mesenchyme cultured under tensile strain remodel collagen type I tubes to produce fibrillar collagen type II.

In this work, we studied the effects of tensile strain on limb bud mesenchymal cells (MSC) cultured on a collagen type I tubular scaffold. A novel bioreactor was designed to culture the cells while subjecting the tubular scaffold to tensile stress and strain. Control samples included unseeded and MSC-seeded tubes cultured for 2 weeks under unloaded, no-strain conditions, and unseeded tubes subjected to prolonged tensile stress and strain. Mechanical properties of tube specimens were measured under oscillatory compressive stress. Following mechanical testing, scaffolds were fixed for immunohistochemistry or frozen for mRNA extraction. The storage modulii of both seeded/unstrained and seeded/strained tubes were significantly less than that of unseeded tubes, suggesting that MSC disrupted the structure and elasticity of the tubes' collagen type I. At a frequency of 1.0 Hz, the loss tangent of seeded/strained tubes was more than 2.5 times greater than that of seeded/unstrained tubes, and almost 6 times greater than that of unseeded tubes. Confocal microscopy and qRT-PCR results demonstrated that collagen type II and aggrecan expression was upregulated in the seeded/strained tubes. The images also show, for the first time, that culture under tensile strain induces MSC to remodel the collagen type I tube with collagen type II and aggrecan expression into fibrils dispersed throughout the matrix. The seeded/unstrained tubes manifested less collagen type II with a more random expression pattern. Compared to seeded/unstrained tubes, qRT-PCR for collagen type II in the seeded/strained tubes showed a 4-fold increase in the message for collagen type II and a 13-fold increase in the message for aggrecan. These results demonstrate that MSC cultured for at least some period under tensile strain are able to remodel collagen type I scaffolds to produce a more viscous construct having many of the mechanical and biological features of engineered cartilage.