Limitation of Hall‐Petch relationship for interpreting scratch on polycrystalline copper using spherical indenter

It is widely known that grain boundary can play a big role in influencing crystal deformation (Hall-Petch effect). This has been intensively studied and widely used as a strengthening mechanism for material component design and manufacture. In the recent years, grain size gradient was introduced by modifying the surface of material component to demonstrate that high strength could be achieved with little compromise in losing ductility [K. Lu, Science 345 p.1455 (2016)]. However, in addition to the grain refinement introduced by the surface treatment, there are also work-hardening, even residual stress; as a result, it is difficult (sometimes impossible) to separate which mechanism is key to provide the strengthening effect. In this study, a well-defined interface between coarse grain and fine grain copper was created using electro-deposition method to provide a simplified case for investigation of the grain size refinement influence: the contribution from work-hardening and residual stress is considered as negligible. Micro-scratch was carried out using a spherical indenter (R=20µm) across this clear boundary as demonstrated in the Figure 1. Preliminary results suggested that the grain orientation could be a key factor in determining the measured scratch hardness, sometime even more significant than the contribution from grain size strengthening for scratch resistance. This work contributes new knowledge to better tune the crystal orientation/grain size combination to achieve the desired mechanical strength/ductility at small scales. Please click Additional Files below to see the full abstract

37 - Does the Quality or Quantity of Friendships Improve Emotions?

Does the Quality or Quantity of Friendships Improve Emotions? Friendship is defined by researchers as a reciprocal, mutual, voluntary relationship with strong emotional bonds (Rubin, Bukowski, & Bowker, 2015). Having close friends during adolescence promotes a subjective sense of well-being (Jose, 2015). However, previous research on friendship has failed to clarify the differential effect of friendship quality and the total amount of friends on positive and negative emotions, particularly in Chinese culture. The goal of the current study was to examine the effect of friendship quality and the amount of friends on positive and negative emotions among Chinese adolescents. In order to do this, we collected data from 674 adolescents in Central China. The amount of friends was identified by using peer-nominations and the quality of friendships was measured by using a self-report measure of security, satisfaction, intimacy, helping and trust. In addition, positive and negative emotions were assessed using a self-report measure. Regression analysis was used to analyze the effect of friendship quality and the amount of friends on emotions. Results showed that the amount of friends (β = .082, p \u3c .05), satisfaction with friends (β = .123, p \u3c .05), and intimacy between friends (β = .173, p \u3c .05) were significant predictors of positive emotions, F (3, 670) = 21.22, p \u3c .01. Security (β = -.097, p \u3c .05) was a significant predictor of negative emotions, F (1, 672) = 6.39, p \u3c .01. The discussion focuses on friendships in Chinese culture and its implications for adolescents’ subjective well-being and social skills interventions. Keywords: friendship quality, Chinese culture, adolescents, emotions, amount of friend

Lack of Evidence for erm(B) Infiltration Into Erythromycin-Resistant Campylobacter coli and Campylobacter jejuni from Commercial Turkey Production in Eastern North Carolina: A Major Turkey-Growing Region in the United States

In Campylobacter spp., resistance to erythromycin and other macrolides has typically implicated ribosomal mutations, especially substitutions in the 23S rRNA genes. However, in 2014, the macrolide resistance gene erm(B) was reported for the first time in Campylobacter and shown to be harbored by a multidrug resistance island in the chromosome of the swine-derived strain Campylobacter coli ZC113. erm(B)-positive C. coli and Campylobacter jejuni strains from the food supply have been mostly reported from China. However, erm(B)-positive C. coli isolates were also detected recently in fecal samples from turkeys in Spain. To determine whether erm(B) may be harbored by erythromycin-resistant Campylobacter from commercial turkey production in eastern North Carolina, a major turkey-growing region in the United States, we investigated a panel of 178 erythromycin-resistant isolates (174 C. coli, 4 C. jejuni) using PCR with erm(B)-specific primers. None of the isolates were PCR-positive for erm(B) and sequence analysis of a subset of these erythromycin-resistant isolates revealed that all harbored A2075G substitutions in the 23S rRNA genes. Data fail to provide evidence for infiltration of erm(B) into erythromycin-resistant Campylobacter from commercial turkey production in this region and suggest the need for continuing surveillance

A Systematic and Critical Review of Discrete Choice Experiments in Asthma and Chronic Obstructive Pulmonary Disease

BACKGROUND: Regulators have called for greater emphasis on the role of the patient voice to inform medical product development and decision making, and expert guidelines and reports for asthma and chronic obstructive pulmonary disease (COPD) both explicitly recommend the consideration of patient preferences in the management of these diseases. Discrete choice experiments (DCEs) are commonly used to quantify stakeholders’ treatment preferences and estimate the trade-offs they are willing to make between outcomes such as treatment benefits and risks. OBJECTIVE: The aim of this systematic literature review is to provide an up-to-date and critical review of DCEs published in asthma and COPD; specifically, we aim to evaluate the subject of preference studies conducted in asthma and COPD, what attributes have been included, stakeholders’ preferences, and the consistency in reporting of instrument development, testing and reporting of results. METHODS: A systematic review of published DCEs on asthma and COPD treatments was conducted using Embase, Medline and the Cochrane Database of Systematic Reviews. Studies were included if they included a DCE conducted in a relevant population (e.g. patients with asthma or COPD or their caregivers, asthma or COPD-treating clinicians, or the general population), and reported quantitative outcomes on participants’ preferences. Study characteristics were summarised descriptively, and descriptive analyses of attribute categories, consistency in reporting on key criteria, and stakeholder preferences were undertaken. RESULTS: A total of 33 eligible studies were identified, including 28 unique DCEs. The majority (n = 20; 71%) of studies were conducted in a patient sample. Studies focused on inhaler treatments, and included attributes in five key categories: symptoms and treatment benefits (n = 23; 82%), treatment convenience (n = 19; 68%), treatment cost (n = 17; 61%), treatment risks (n = 13; 46%), and other (n = 10; 36%). Symptoms and treatment benefits were the attributes most frequently ranked as important to patients (n = 26, 72%), followed by treatment risks (n = 7, 39%). Several studies (n = 9, 32%) did not qualitatively pre-test their DCE, and a majority did not report the uncertainty in estimated outcomes (n = 18; 64%). CONCLUSIONS: DCEs in asthma and COPD have focused on treatment benefits and convenience, with less evidence generated on participants’ risk tolerance. Quality criteria and reporting standards are needed to promote study quality and ensure consistency in reporting between studies. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s40271-021-00536-w

Towards Transparent, Reusable, and Customizable Data Science in Computational Notebooks

Data science workflows are human-centered processes involving on-demand programming and analysis. While programmable and interactive interfaces such as widgets embedded within computational notebooks are suitable for these workflows, they lack robust state management capabilities and do not support user-defined customization of the interactive components. The absence of such capabilities hinders workflow reusability and transparency while limiting the scope of exploration of the end-users. In response, we developed MAGNETON, a framework for authoring interactive widgets within computational notebooks that enables transparent, reusable, and customizable data science workflows. The framework enhances existing widgets to support fine-grained interaction history management, reusable states, and user-defined customizations. We conducted three case studies in a real-world knowledge graph construction and serving platform to evaluate the effectiveness of these widgets. Based on the observations, we discuss future implications of employing MAGNETON widgets for general-purpose data science workflows.Comment: To appear at Extended Abstracts of the 2023 CHI Conference on Human Factors in Computing System

Correction to: A Systematic and Critical Review of Discrete Choice Experiments in Asthma and Chronic Obstructive Pulmonary Disease (Jul, 10.1007/s40271-.021-.00536-w, 2021)

The article “A Systematic and Critical Review of Discrete Choice Experiments in Asthma and Chronic Obstructive Pulmonary Disease”, written by Hannah Collacott, Dian Zhang, Sebastian Heidenreich and Tommi Tervonen1 was originally published electronically on the publisher’s internet portal on 12 July 2021 without open access.</p

Nanomechanical behavior of individual phases and size effect in WC-Co by means of high temperature nanoindentation and electron microscopy: A study from ambient to high temperature

The dependence of the hardness and deformation mechanism of individual phases in WC-Co on microstructural parameters such as grain size and orientation was investigated by nanoindentation and electron microscopy from ambient to high temperature. At room temperature, the binder phase only exhibits a hardness of about 10 GPa, whilst the hardness of WC grains were measured about 29-30 and 37 GPa for the prismatic and basal orientation, respectively. All WC orientations exhibited a similar decrease in hardness as the temperature increased. A broad range of WC prismatic grain areas (AWC-prismatic), from about 2 to 1000 µm2, were selected and subsequently indented to investigate any size effect. A slight decrease in the hardness of WC prismatic grains (HWC-prismatic) as a function of AWC-prismatic was observed. Damage mechanisms occurring in WC-Co during nanoindentation were investigated for the different grain orientation at various temperature. The damage was visualised using electron microscopy near the residual indent as well as focused ion beam sectioning across the indent. The three dimensional distribution of plastic deformation across multiple grains in the vicinity of an indent was examined using Electron Back Scattered Diffraction (EBSD) and Electron Channelling Contrast Imaging (ECCI). The ECCI enabled the observation of crystal defects, especially dislocations, in th plastic zone. The dislocation density and spatial distribution in the deformed WC-Co were compared to that of an untested WC-Co to relate the quantity of defects as well as their origin to the state of stress in the material. The collected data represent useful guidance for manufacturer of hardmetals, provides important information underpinning an understanding of the relationship between WC-Co microstructure and mechanical properties, and also highlight the performance of WC-Co at operating temperatures. Please click Additional Files below to see the full abstract