43 research outputs found
Towards a rapid, non-contact shaping method for fibre metal laminates using a laser source
Abstract Since their initial development, fibre metal laminates (FMLs) have slowly started to be used by industry, particularly the aerospace sector. One of the reasons for the relatively slow adoption of FMLs is due to the difficulties faced in shaping them to the desired geometry. Whilst traditional processes such as roll forming are effective in shaping monolithic materials, these processes could potentially destroy the mechanical properties of the composite layer. The approached investigated here uses thermal or laser forming (LF) to shape flat panels of thermosetting glass fibre based FMLs into 2D geometries. This initial empirical investigation covers the effectiveness of the various LF processes and the effects of various parameters have on the forming process. These include laser parameters such as power and velocity and material parameters such as FML lay-up strategy, fibre orientation and comparison with monolithic materials
Nanoscale Mobility of the Apo State and TARP Stoichiometry Dictate the Gating Behavior of Alternatively Spliced AMPA Receptors.
Neurotransmitter-gated ion channels are allosteric proteins that switch on and off in response to agonist binding. Most studies have focused on the agonist-bound, activated channel while assigning a lesser role to the apo or resting state. Here, we show that nanoscale mobility of resting α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)-type ionotropic glutamate receptors (AMPA receptors) predetermines responsiveness to neurotransmitter, allosteric anions and TARP auxiliary subunits. Mobility at rest is regulated by alternative splicing of the flip/flop cassette of the ligand-binding domain, which controls motions in the distant AMPA receptor N-terminal domain (NTD). Flip variants promote moderate NTD movement, which establishes slower channel desensitization and robust regulation by anions and auxiliary subunits. In contrast, greater NTD mobility imparted by the flop cassette acts as a master switch to override allosteric regulation. In AMPA receptor heteromers, TARP stoichiometry further modifies these actions of the flip/flop cassette generating two functionally distinct classes of partially and fully TARPed receptors typical of cerebellar stellate and Purkinje cells
Micellar nanoparticles with tuneable morphologies through interactions between nucleobase-containing synthetic polymers in aqueous solution
YesHerein, we report the preparation of nucleobase-containing synthetic amphiphilic diblock copolymers using RAFT polymerization. Well-defined spherical micelles can be formed in aqueous solutions through the self-assembly of the amphiphilic copolymers, with the nucleobase functionality sequestered in the core of the particles. Following assembly, copolymers with the complementary nucleobase were introduced into the preformed micellar solutions. This addition induced a change in nanostructure size and morphology and this reorganization was fully characterized by DLS, TEM, SLS and SAXS analysis. The insertion of copolymers with the complementary nucleobase into formed micelles was also confirmed by 1 H NMR and UV-vis spectroscopy. For micelles consisting of moderately short hydrophobic blocks, upon the addition of complementary nucleobase copolymer a decrease in size was observed but without any accompanying morphological change. For micelles formed from longer hydrophobic blocks, a morphological transition from spheres to cylinders and then to smaller spheres was observed upon increasing the amount of the complementary copolymer. This work highlights how complementary nucleobase interactions can be used to induce nanostructure reorganization and through a simple mixing process provide access to different nanostructure sizes and morphologies.University of Warwick, China Scholarship Council (CSC), National Science Foundation (U.S.) (NSF), Engineering and Physical Sciences Research Council (EPSRC), European Research Council (ERC
Multiorgan MRI findings after hospitalisation with COVID-19 in the UK (C-MORE): a prospective, multicentre, observational cohort study
Introduction:
The multiorgan impact of moderate to severe coronavirus infections in the post-acute phase is still poorly understood. We aimed to evaluate the excess burden of multiorgan abnormalities after hospitalisation with COVID-19, evaluate their determinants, and explore associations with patient-related outcome measures.
Methods:
In a prospective, UK-wide, multicentre MRI follow-up study (C-MORE), adults (aged ≥18 years) discharged from hospital following COVID-19 who were included in Tier 2 of the Post-hospitalisation COVID-19 study (PHOSP-COVID) and contemporary controls with no evidence of previous COVID-19 (SARS-CoV-2 nucleocapsid antibody negative) underwent multiorgan MRI (lungs, heart, brain, liver, and kidneys) with quantitative and qualitative assessment of images and clinical adjudication when relevant. Individuals with end-stage renal failure or contraindications to MRI were excluded. Participants also underwent detailed recording of symptoms, and physiological and biochemical tests. The primary outcome was the excess burden of multiorgan abnormalities (two or more organs) relative to controls, with further adjustments for potential confounders. The C-MORE study is ongoing and is registered with ClinicalTrials.gov, NCT04510025.
Findings:
Of 2710 participants in Tier 2 of PHOSP-COVID, 531 were recruited across 13 UK-wide C-MORE sites. After exclusions, 259 C-MORE patients (mean age 57 years [SD 12]; 158 [61%] male and 101 [39%] female) who were discharged from hospital with PCR-confirmed or clinically diagnosed COVID-19 between March 1, 2020, and Nov 1, 2021, and 52 non-COVID-19 controls from the community (mean age 49 years [SD 14]; 30 [58%] male and 22 [42%] female) were included in the analysis. Patients were assessed at a median of 5·0 months (IQR 4·2–6·3) after hospital discharge. Compared with non-COVID-19 controls, patients were older, living with more obesity, and had more comorbidities. Multiorgan abnormalities on MRI were more frequent in patients than in controls (157 [61%] of 259 vs 14 [27%] of 52; p<0·0001) and independently associated with COVID-19 status (odds ratio [OR] 2·9 [95% CI 1·5–5·8]; padjusted=0·0023) after adjusting for relevant confounders. Compared with controls, patients were more likely to have MRI evidence of lung abnormalities (p=0·0001; parenchymal abnormalities), brain abnormalities (p<0·0001; more white matter hyperintensities and regional brain volume reduction), and kidney abnormalities (p=0·014; lower medullary T1 and loss of corticomedullary differentiation), whereas cardiac and liver MRI abnormalities were similar between patients and controls. Patients with multiorgan abnormalities were older (difference in mean age 7 years [95% CI 4–10]; mean age of 59·8 years [SD 11·7] with multiorgan abnormalities vs mean age of 52·8 years [11·9] without multiorgan abnormalities; p<0·0001), more likely to have three or more comorbidities (OR 2·47 [1·32–4·82]; padjusted=0·0059), and more likely to have a more severe acute infection (acute CRP >5mg/L, OR 3·55 [1·23–11·88]; padjusted=0·025) than those without multiorgan abnormalities. Presence of lung MRI abnormalities was associated with a two-fold higher risk of chest tightness, and multiorgan MRI abnormalities were associated with severe and very severe persistent physical and mental health impairment (PHOSP-COVID symptom clusters) after hospitalisation.
Interpretation:
After hospitalisation for COVID-19, people are at risk of multiorgan abnormalities in the medium term. Our findings emphasise the need for proactive multidisciplinary care pathways, with the potential for imaging to guide surveillance frequency and therapeutic stratification
Composition and Activity of Microbial Communities along the Redox Gradient of an Alkaline, Hypersaline, Lake
We compared the composition of microbial communities obtained by sequencing 16S rRNA gene amplicons with taxonomy derived from metatranscriptomes from the same samples. Samples were collected from alkaline, hypersaline Mono Lake, California, USA at five depths that captured the major redox zones of the lake during the onset of meromixis. The prokaryotic community was dominated by bacteria from the phyla Proteobacteria, Firmicutes, and Bacteroidetes, while the picoeukaryotic chlorophyte Picocystis dominated the eukaryotes. Most (80%) of the abundant (>1% relative abundance) OTUs recovered as amplicons of 16S rRNA genes have been reported in previous surveys, indicating that Mono Lake's microbial community has remained stable over 12 years that have included periods of regular, annual overturn interspersed by episodes of prolonged meromixis that result in extremely reducing conditions in bottom water. Metatranscriptomic sequences binned predominately to the Gammaproteobacteria genera Thioalkalivibrio (4–13%) and Thioalkalimicrobium (0–14%); and to the Firmicutes genera Dethiobacter (0–5%) and Clostridium (1–4%), which were also abundant in the 16S rRNA gene amplicon libraries. This study provides insight into the taxonomic affiliations of transcriptionally active communities of the lake's water column under different redox conditions
Natural Resources Research Institute Technical Report
Part II, Technical Report, NRRI/TR-87-3, December 1987The study objective was to analyze prospects for manufacturing wood
products in Minnesota using birch in small scale and cottage industries.
The current status of Minnesota's birch-based industry is described
indicating that low valued firewood is 60 percent of consumption and the
majority of the remaining consumption is in sawbolts. In secondary
manufacturing most birch is used in low value-added products.
Cottage industry is defined in several ways, but by any definition
Minnesota has been effective in developing this segment. Some of
Minnesota's cottage industry is using wood as a raw material. Three
successful companies are profiled; a classic cottage industry, a small
home-based cooking utensil manufacturer and a small wood products
manufacturer. Each of these uses wood to a greater or lesser degree.
There are good prospects for increasing the use of wood, including birch,
in companies of this type. A discussion of challenges is presented and
specific recommendations made. The profiled cottage industry would
serve as a model for further expansion. Creation of a Minnesota wood
turning industry should be explored. Establishment of a prototype manufacturing
shop would help existing and new operations.Blandin Foundation, Grand Rapids, Minnesota; Natural Resources Research Institute, University of Minnesota, Duluth
3151 Miller Trunk Highway, Duluth , Minnesota 5581
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Activation of P2X4 receptors induces an increase in the area of the extracellular region and a decrease in receptor mobility.
The P2X4 receptor (P2X4R) is an ATP-gated cation channel. Here, we used fast-scan atomic force microscopy (AFM) to visualize changes in the structure and mobility of individual P2X4Rs in response to activation. P2X4Rs were purified from detergent extracts of transfected cells and integrated into lipid bilayers. Activation resulted in a rapid (2Â s) and substantial (10-20Â nm2 ) increase in the cross-sectional area of the extracellular region of the receptor and a corresponding decrease in receptor mobility. Both effects were blocked by the P2X4R antagonist 5-BDBD. Addition of cholesterol to the bilayer reduced receptor mobility, although the ATP-induced reduction in mobility was still observed. We suggest that the observed responses to activation may have functional consequences for purinergic signalling
Environmental Sources of Bacteria Differentially Influence Host-Associated Microbial Dynamics.
Host-associated microbial dynamics are influenced by dietary and immune factors, but how exogenous microbial exposure shapes host-microbe dynamics remains poorly characterized. To investigate this phenomenon, we characterized the skin, rectum, and respiratory tract-associated microbiota in four aquarium-housed dolphins daily over a period of 6 weeks, including administration of a probiotic during weeks 4 to 6. The environmental bacterial sources were also characterized, including the animals' human handlers, the aquarium air and water, and the dolphins' food supply. Continuous microbial exposure occurred between all sites, yet each environment maintained a characteristic microbiota, suggesting that the majority of exposure events do not result in colonization. Small changes in water physicochemistry had a significant but weak correlation with change in dolphin-associated bacterial richness but had no influence on phylogenetic diversity. Food and air microbiota were the richest and had the largest conditional influence on other microbiota in the absence of probiotics, but during probiotic administration, food alone had the largest influence on the stability of the dolphin microbiota. Our results suggest that respiratory tract and gastrointestinal epithelium interactions with air- and food-associated microbes had the biggest influence on host-microbiota dynamics, while other interactions, such as skin transmission, played only a minor role. Finally, direct oral stimulation with a foreign exogenous microbial source can have a profound effect on microbial stability. IMPORTANCE These results provide valuable insights into the ecological influence of exogenous microbial exposure, as well as laying the foundation for improving aquarium management practices. By comparing data for dolphins from aquaria that use natural versus artificial seawater, we demonstrate the potential influence of aquarium water disinfection procedures on dolphin microbial dynamics
Table_3_Transport from the wild rapidly alters the diversity and composition of skin microbial communities and antifungal taxa in spring peeper frogs.xlsx
Amphibians are routinely collected from the wild and added into managed care and public display facilities; however, there is a gap in understanding how these practices might alter the diversity and composition of skin microbial communities on these animals. The aim of this study was to evaluate and compare skin microbial communities of spring peeper frogs (Pseudacris crucifer) from acquisition in the wild through the end of their quarantine period and identify microbial taxa with antifungal properties. From an original group of seventy-six frogs, cohorts of ten were swabbed when acquired in the wild, upon transport from the wild, and swabbed throughout a 9-week quarantine period while under managed care. An immediate loss of microbial richness and diversity was evident upon transfer of the frogs from their original environment and continued throughout subsequent sampling time-points during quarantine. Importantly, antifungal taxa comprised significantly more of the overall skin community after the frogs were moved from the wild, largely due to members of the family Moraxellaceae. Overall, our findings demonstrate that amphibian skin microbiome changes immediately on removal from the wild, and that these changes persist throughout quarantine while being housed under managed care. This may play a pivotal role in the development of dermatological disease and have implications in the health and immune function of amphibians.</p