Full field strain during tensile deformation is measured in parts produced by material extrusion additive manufacturing (MEAM) using digital image correlation. Many studies have been conducted to ...examine stress and strain at the part level; however, local levels of stress and strain within MEAM parts remain largely unexplored. This study documents the effects of tensile loading on acrylonitrile butadiene styrene parts fabricated with MEAM using both solid and sparse infill geometries. The effects of different toolpath orientations on local tensile strain are also studied. A novel build strategy for creating sparse infill geometry to improve part strength is introduced and tested.
Zinc (Zn) is an essential micronutrient and cofactor for up to 10% of proteins in living organisms. During Zn limitation, specialized enzymes called metallochaperones are predicted to allocate Zn to ...specific metalloproteins. This function has been putatively assigned to G3E GTPase COG0523 proteins, yet no Zn metallochaperone has been experimentally identified in any organism. Here, we functionally characterize a family of COG0523 proteins that is conserved across vertebrates. We identify Zn metalloprotease methionine aminopeptidase 1 (METAP1) as a COG0523 client, leading to the redesignation of this group of COG0523 proteins as the Zn-regulated GTPase metalloprotein activator (ZNG1) family. Using biochemical, structural, genetic, and pharmacological approaches across evolutionarily divergent models, including zebrafish and mice, we demonstrate a critical role for ZNG1 proteins in regulating cellular Zn homeostasis. Collectively, these data reveal the existence of a family of Zn metallochaperones and assign ZNG1 an important role for intracellular Zn trafficking.
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•The N terminus of ZNG1 interacts with the zinc finger of METAP1•ZNG1 promotes METAP1 activity in a GTP-hydrolysis- and Zn-dependent manner•Loss of ZNG1 impairs mitochondrial function and cellular proliferation•Zng1 mutant animals are sensitive to Zn starvation and inhibition of METAP activity
ZNG1 is a putative Zn metallochaperone that supports the activity of Zn-dependent proteins in vertebrates, thereby maintaining Zn homeostasis and cellular integrity.
Enterotoxigenic Escherichia coli (ETEC) is estimated to cause approximately 380,000 deaths annually during sporadic or epidemic outbreaks worldwide. Development of vaccines against ETEC is very ...challenging due to the vast heterogeneity of the ETEC strains. An effective vaccines would have to be multicomponent to provide coverage of over ten ETEC strains with genetic variabilities. There is currently no vaccine licensed to prevent ETEC. Nanobodies are successful new biologics in treating mucosal infectious disease as they recognize conserved epitopes on hypervariable pathogens. Cocktails consisting of multiple nanobodies could provide even broader epitope coverage at a lower cost compared to monoclonal antibodies. Identification of conserved epitopes by nanobodies can also assist reverse engineering of an effective vaccine against ETEC. By screening nanobodies from immunized llamas and a naïve yeast display library against adhesins of colonization factors, we identified single nanobodies that show cross-protective potency against eleven major pathogenic ETEC strains in vitro. Oral administration of nanobodies led to a significant reduction of bacterial colonization in animals. Moreover, nanobody-IgA fusion showed extended inhibitory activity in mouse colonization compared to commercial hyperimmune bovine colostrum product used for prevention of ETEC-induced diarrhea. Structural analysis revealed that nanobodies recognized a highly-conserved epitope within the putative receptor binding region of ETEC adhesins. Our findings support further rational design of a pan-ETEC vaccine to elicit robust immune responses targeting this conserved epitope.
Speed trends in male distance running Kruse, Timothy N; Carter, Rickey E; Rosedahl, Jordan K ...
PloS one,
11/2014, Letnik:
9, Številka:
11
Journal Article
Recenzirano
Odprti dostop
The major cycling "Grand Tours" have shown an attenuation of performance over the last decade. This has been interpreted as circumstantial evidence that newer anti-doping strategies have reduced the ...use of performance-enhancing drugs. To examine this idea under more controlled conditions, speed trends for world class 5000 m, 10000 m, and marathon performances by men from 1980 to 2013 were analyzed. We obtained comprehensive records from the International Association of Athletics Federations, Association of Road Racing Statisticians, and the Track and Field All-time Performances database webpages. The top 40 performances for each event and year were selected for regression analysis. For the three distances, we noted cumulative performance improvements in the 1990s thru the mid-2000s. After the peak speed years of the mid 2000 s, there has been limited improvement in the 5000 m and 10,000 m and world records set during that time remain in place today, marking the longest period of time between new records since the early 1940s. By contrast marathon speed continues to increase and the world record has been lowered four times since 2007, including in 2013. While the speed trends for 5000 m and 10000 m track results parallel those seen in elite cycling, the marathon trends do not. We discuss a number of explanations other than improved anti-doping strategies that might account for these divergent findings.
...we work to combine inquiry and engineering when we can. Because we do not have a stove in our classroom, we bring out a hot plate to confirm that heating up the water is a possibility. Sometimes ...we use this as an opportunity to talk about NOS by asking, "Why do scientists make assumptions when doing their work?" Now that the class understands how we can collect data on temperature and color spread, we have small groups of students brainstorm how they could investigate how fast the food coloring will disperse using different temperatures. Alternative strategies for differentiation and cost * If your school does not have hot plates, consider using a percolator or coffee maker as a substitute. * If time or student ability is of concern, having the various temperatures of water set up in advance can lighten students' cognitive load. * Also, if time is a concern, the food coloring activity can be done as a demonstration.
The impact of the COVID-19 pandemic on US adults' smoking and quitting behaviors is unclear. We explored the impact of COVID-19 on smoking behaviors, risk perceptions, and reactions to text messages ...during a statewide stay-at-home advisory among primary care patients who were trying to quit. From May-June 2020, we interviewed smokers enrolled in a 12-week, pilot cessation trial providing text messaging and mailed nicotine replacement medication (NCT04020718). Twenty-two individuals (82% white, mean age 55 years), representing 88% of trial participants during the stay-at-home advisory, completed exit interviews; four (18%) of them reported abstinence. Interviews were thematically analyzed by two coders. COVID-19-induced environmental changes had mixed effects, facilitating quitting for some and impeding quitting for others. While stress increased for many, those who quit found ways to cope with stress. Generally, participants felt at risk for COVID-19 complications but not at increased risk of becoming infected. Reactions to COVID-19 and quitting behaviors differed across age groups, older participants reported difficulties coping with isolation (e.g., feeling disappointed when a text message came from the study and not a live person). Findings suggest that cessation interventions addressing stress and boredom are needed during COVID-19, while smokers experiencing isolation may benefit from live-person supports.
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