Polyol Synthesis of Silver Nanowires by Heterogeneous Nucleation and Mechanistic Aspects Influencing its Length and Diameter

Various additives are employed in the polyol synthesis of silver nanowires (Ag NWs), which are typically halide salts such as NaCl. A variety of mechanistic roles have been suggested for these additives. My research showed that the early addition of NaCl in the polyol synthesis of Ag NWs from AgNO3 in ethylene glycol results in the rapid formation of AgCl nanocubes, which induce the heterogeneous nucleation of metallic Ag upon their surfaces. Ag NWs subsequently grow from these nucleation sites. The conclusions are supported by studies using ex-situ generated AgCl nanocubes. Additionally, the final mean silver nanowire diameter is found to be independent of the size of the heterogeneous nucleant, showing that the diameter is not significantly influenced by the nucleation event. Kinetics studies determine that nanowire diameter, length, and aspect ratio grow in parallel to one another and with the extent of the Ag+ reduction reaction, demonstrating that growth is reduction-rate limited. The results are interpreted to support nanowire growth by a surface-catalyzed reduction process occurring on all nanowire surfaces, and to exclude nanoparticle aggregation or Ostwald ripening as primary components of the growth mechanism

Parents’ Perspectives on Variants of Uncertain Significance from Chromosome Microarray Analysis

Chromosomal microarray analysis (CMA) for unexplained anomalies and developmental delay has improved diagnosis rates, but results classified as variants of uncertain significance (VUS) may challenge both clinicians and families. We explored the impact of such results on families, including parental knowledge, understanding and interpretation. Semi‐structured telephone interviews were conducted with parents (N = 14) who received genetic counseling for a VUS in their child. Transcripts were analyzed through an iterative coding process. Participants demonstrated a range of recall and personal interpretation regarding whether test results provided a causal explanation for their children’s health issues. Participants maintained contradictory interpretations, describing results as answers while maintaining that little clarification of their child’s condition had been provided. Reported benefits included obtaining medical services and personal validation. Parents described adaptation/coping processes similar to those occurring after positive test results. Recall of terminology, including “VUS” and precise CMA abnormalities, was poor. However, most demonstrated conceptual understanding of scientific uncertainty. All participants expressed intentions to return for recommended genetics follow‐up but had misconceptions about how this would occur. These results provide insight into the patient‐and‐family experience when receiving uncertain genomic findings, emphasize the importance of exploring uncertainty during the communication process, and highlight areas for potential attention or improvement in the clinical encounter.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146918/1/jgc40101.pd

The Penguin: a Low Reynolds Number Powered Glider for Station Keeping Missions

The Penguin is a low Reynolds number (approx. 100,000) remotely piloted vehicle (RPV). It was designed to fly three laps indoors around two pylons in a figure-eight course while maximizing loiter time. The Penguin's low Reynolds number mission is an important one currently being studied for possible future flights in the atmospheres of other planets and for specialized military missions. Although the Penguin's mission seemed quite simple at first, the challenges of such low Reynolds number flight have proven to be quite unique. In addition to the constraint of low Reynolds number flight, the aircraft had to be robust in its control, highly durable, and it had to carry a small instrument package. The Penguin's flight plan, concept, performance, aerodynamic design, weight estimation, structural design, propulsion, stability and control, and cost estimate is detailed

Tensile Tests of Round-head, Flat-head, and Brazier-head Rivets

An investigation was conducted to determine the tensile strength of round-head (AN43C), flat-head(AN442), and brazier-head (AN4556) aluminum-alloy rivets because of the scarcity of information on the tensile strength of rivets. The results of the investigation are presented as curves that show the variation of the ratio of the tensile strength of the rivet to the tensile strength of the rivet crank with the ratio of the sheet thickness to the rivet diameter for the different types of rivet

Factors Influencing high adolescent pregnancy rate in Riobamba, Ecuador

The country of Ecuador has the highest rate of adolescent pregnancy in Latin America and the Caribbean. Risk factors associated with this pregnancy rate need to be explored to effectively implement educational youth programs.1 Early sexual initiation, poor reproductive health knowledge, and disruption of family structure are hypothesized to be major risk factors of adolescent (<20 years) motherhood (AMH) in Riobamba, Ecuador.2 We conducted a case-control study with case being women <20 years of age during first pregnancy and control being women ≥20 years of age during first pregnancy. Controls were not matched. The study took place in June/July of 2021 in five public governmental primary health clinics within Riobamba, Ecuador with the primary goal of determining risk factors associated with AMH. Age responses were used to designate group status. Risk factors were analyzed using Welch’s two-sample t-tests and Fisher’s Exact tests. 198 participants were analyzed: 99 who had AMH and 99 who had non-AMH. Adolescent mothers were significantly younger during first sexual encounter than adult mothers. Adolescent mothers were also more likely to lack reproductive health knowledge and have a disruption in family structure. While our study was able to broadly explore the risk factors for AMH, the underlying causes of these risk factors, such as societal pressures, need to be examined further. Early education about sexual health and use of contraception should be an initial goal of Riobamba’s programs to reduce AMH