48 research outputs found
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Effects of Temperature and Moisture Content on Bonding Performance of Mass Plywood Panels
As a new product patented by Freres Lumber Company in 2018, little information exists for manu-facturing procedures of mass plywood panels (MPP). At first glance, MPP may appear to be ply-wood, laminated veneer lumber (LVL), or similar to conventional cross-laminated timber (CLT). Often manufacturers, as well as users, of MPP must infer from experiences with plywood, LVL, and CLT in regard to manufacturing operating parameters and in-service performance. As is the situation with all adhesive bonded wood products, moisture content and temperature conditions should be considered during its manufacturing and end-use applications. The main objective of this thesis was the creation of an operational envelope regarding temperature and moisture con-tent of materials in the factory environment, with particular attention to melamine-formaldehyde adhesive bonds in MPP. Small-scale and full-scale test procedures were utilized on MPP speci-mens produced at 5 different surface temperatures (13 to 39 °C) and 3 different surface moisture contents (2 to 11%). SmallÂscale mechanical lapÂshear tests were performed on dry specimens and specimens after accelerated weathering according to ASTM D3434Â18. Degradation of the melamineÂformaldehyde (MF) bondline performance was observed throughout accelerated weathering. The short-span bending and block-shear tests on full-scale MPP did not discover significant differences amongst different manufacturing conditions in the dry and wet conditions. Seventeen months of monitoring environmental conditions inside the MPP manufacturing facility showed daily average temperate range from 21 to 27 °C and relative humidity 20 to 59%. Calcu-lated equilibrium moisture content conditions varied from 4.6 to 10.6%. Measured wood substrate temperature ranged from 23 to 30 °C and MC ranged from 5 to 8%. Therefore, actual manufac-turing conditions were within the parameters of this study. High variation in the data restrains the author from identifying statistically significant effects of surface temperature or moisture content on the bond performance of MPP. However, the melamine-formaldehyde adhesive bond per-formed consistently under all test conditions, with failure of test specimens occurring most often in the wood substrate. While some differences in bond performance were observed between sur-face temperature and surface moisture contents, the differences were small. Therefore, the tem-perature range of 13 to 39 °C (at 7% MC) and moisture content range from 2 to 11% (at 26 °C) is a satisfactory operating envelope. In regard to bond strength after accelerated weathering, small-scale tests showed a similar trend as full-scale tests. Furthermore, small-scale adhesive bond strength retention after 20 cycles (total of 24 hours) of accelerated weathering, according to ASTM D3434, was roughly equivalent to short-span shear strength retention of full-scale MPP specimens after 6 weeks of constant water soaking. However, the failure mode of the short-span shear specimens was rolling shear of the adjacent crossband veneer and not shear failure of the MF bondline
Loss of TMEM106B potentiates lysosomal and FTLD-like pathology in progranulin-deficient mice
Single nucleotide polymorphisms (SNPs) in TMEM106B encoding the lysosomal type II transmembrane protein 106B increase the risk for frontotemporal lobar degeneration (FTLD) of GRN (progranulin gene) mutation carriers. Currently, it is unclear if progranulin (PGRN) and TMEM106B are synergistically linked and if a gain or a loss of function of TMEM106B is responsible for the increased disease risk of patients with GRN haploinsufficiency. We therefore compare behavioral abnormalities, gene expression patterns, lysosomal activity, and TDP-43 pathology in single and double knockout animals. Grn-/- /Tmem106b-/- mice show a strongly reduced life span and massive motor deficits. Gene expression analysis reveals an upregulation of molecular signature characteristic for disease-associated microglia and autophagy. Dysregulation of maturation of lysosomal proteins as well as an accumulation of ubiquitinated proteins and widespread p62 deposition suggest that proteostasis is impaired. Moreover, while single Grn-/- knockouts only occasionally show TDP-43 pathology, the double knockout mice exhibit deposition of phosphorylated TDP-43. Thus, a loss of function of TMEM106B may enhance the risk for GRN-associated FTLD by reduced protein turnover in the lysosomal/autophagic system
Synthesis and Characterization of High-Performing Sulfur-Free Tannin Foams
Tannin foams are green lightweight materials that have attracted industrial interest for the
manufacturing of sandwich panels for insulation purposes. However, the dimensions of the cells and
the presence of sulfur in the formulation developed until now have discouraged their upscaling. In
this work, we present the synthesis and the characterization of the more promising small cell and
sulfur-free materials. It was observed that, with respect to standard ones, foams catalyzed with nitric
acid present similar physical properties and more phenolic character, which favors the absorption of
ionic pollutants. Conversely, the foams blown with aliphatic solvents and surfactants present smaller
pores, and higher mechanical and insulating properties, without a\ufb00ecting the chemical properties or
the heating value. The combined foam produced with nitric acid as a catalyst and petroleum ether as
a blowing agent result in sulfur-free and small cell material with overall improved features. These
foams have been produced at 30
7 30
7 3 cm3, with high homogeneity and, to date, they represent
the most suitable formulation for industrial upscaling
Eosinophil Morphology Eosinophil granules and degranulation
Endogenous DNA damage is causally associated with the functional decline and transformation of stem cells that characterize aging. DNA lesions that have escaped DNA repair can induce replication stress and genomic breaks that induce senescence and apoptosis. It is not clear how stem and proliferating cells cope with accumulating endogenous DNA lesions and how these ultimately affect the physiology of cells and tissues. Here we have addressed these questions by investigating the hematopoietic system of mice deficient for Rev1, a core factor in DNA translesion synthesis (TLS), the postreplicative bypass of damaged nucleotides. Rev1 hematopoietic stem and progenitor cells displayed compromised proliferation, and replication stress that could be rescued with an antioxidant. The additional disruption of Xpc, essential for global-genome nucleotide excision repair (ggNER) of helix-distorting nucleotide lesions, resulted in the perinatal loss of hematopoietic stem cells, progressive loss of bone marrow, and fatal aplastic anemia between 3 and 4 months of age. This was associated with replication stress, genomic breaks, DNA damage signaling, senescence, and apoptosis in bone marrow. Surprisingly, the collapse of the Rev1Xpc bone marrow was associated with progressive mitochondrial dysfunction and consequent exacerbation of oxidative stress. These data reveal that, to protect its genomic and functional integrity, the hematopoietic system critically depends on the combined activities of repair and replication of helix-distorting oxidative nucleotide lesions by ggNER and Rev1-dependent TLS, respectively. The error-prone nature of TLS may provide mechanistic understanding of the accumulation of mutations in the hematopoietic system upon aging
Chronic PPARÎł Stimulation Shifts Amyloidosis to Higher Fibrillarity but Improves Cognition.
We undertook longitudinal β-amyloid positron emission tomography (Aβ-PET) imaging as a translational tool for monitoring of chronic treatment with the peroxisome proliferator-activated receptor gamma (PPARγ) agonist pioglitazone in Aβ model mice. We thus tested the hypothesis this treatment would rescue from increases of the Aβ-PET signal while promoting spatial learning and preservation of synaptic density. Here, we investigated longitudinally for 5 months PS2APP mice (N = 23; baseline age: 8 months) and App NL-G-F mice (N = 37; baseline age: 5 months) using Aβ-PET. Groups of mice were treated with pioglitazone or vehicle during the follow-up interval. We tested spatial memory performance and confirmed terminal PET findings by immunohistochemical and biochemistry analyses. Surprisingly, Aβ-PET and immunohistochemistry revealed a shift toward higher fibrillary composition of Aβ-plaques during upon chronic pioglitazone treatment. Nonetheless, synaptic density and spatial learning were improved in transgenic mice with pioglitazone treatment, in association with the increased plaque fibrillarity. These translational data suggest that a shift toward higher plaque fibrillarity protects cognitive function and brain integrity. Increases in the Aβ-PET signal upon immunomodulatory treatments targeting Aβ aggregation can thus be protective
Enhancing medical students' communication skills: development and evaluation of an undergraduate training program
<p>Abstract</p> <p>Background</p> <p>There is a relative lack of current research on the effects of specific communication training offered at the beginning of the medical degree program. The newly developed communication training "Basics and Practice in Communication Skills" was pilot tested in 2008 and expanded in the following year at the University Medical Centre Hamburg-Eppendorf in Germany. The goal was to promote and improve the communicative skills of participants and show the usefulness of an early offered intervention on patient-physician communication within the medical curriculum.</p> <p>Methods</p> <p>The students participating in the project and a comparison group of students from the standard degree program were surveyed at the beginning and end of the courses. The survey consisted of a self-assessment of their skills as well as a standardised expert rating and an evaluation of the modules by means of a questionnaire.</p> <p>Results</p> <p>Students who attended the communication skills course exhibited a considerable increase of communication skills in this newly developed training. It was also observed that students in the intervention group had a greater degree of self-assessed competence following training than the medical students in the comparison group. This finding is also reflected in the results from a standardised objective measure.</p> <p>Conclusions</p> <p>The empirical results of the study showed that the training enabled students to acquire specialised competence in communication through the course of a newly developed training program. These findings will be used to establish new communication training at the University Medical Centre Hamburg-Eppendorf.</p
Novel App knock-in mouse model shows key features of amyloid pathology and reveals profound metabolic dysregulation of microglia.
BACKGROUND: Genetic mutations underlying familial Alzheimer\u27s disease (AD) were identified decades ago, but the field is still in search of transformative therapies for patients. While mouse models based on overexpression of mutated transgenes have yielded key insights in mechanisms of disease, those models are subject to artifacts, including random genetic integration of the transgene, ectopic expression and non-physiological protein levels. The genetic engineering of novel mouse models using knock-in approaches addresses some of those limitations. With mounting evidence of the role played by microglia in AD, high-dimensional approaches to phenotype microglia in those models are critical to refine our understanding of the immune response in the brain.
METHODS: We engineered a novel App knock-in mouse model (App
RESULTS: Leveraging multi-omics approaches, we discovered profound alteration of diverse lipids and metabolites as well as an exacerbated disease-associated transcriptomic response in microglia with high intracellular Aβ content. The App
DISCUSSION: Our findings demonstrate that fibrillar Aβ in microglia is associated with lipid dyshomeostasis consistent with lysosomal dysfunction and foam cell phenotypes as well as profound immuno-metabolic perturbations, opening new avenues to further investigate metabolic pathways at play in microglia responding to AD-relevant pathogenesis. The in-depth characterization of pathological hallmarks of AD in this novel and open-access mouse model should serve as a resource for the scientific community to investigate disease-relevant biology
A purified membrane protein from Akkermansia muciniphila or the pasteurized bacterium improves metabolism in obese and diabetic mice
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Report on computational assessment of Tumor Infiltrating Lymphocytes from the International Immuno-Oncology Biomarker Working Group
Funder: U.S. Department of Health & Human Services | NIH | National Cancer Institute (NCI)Funder: National Center for Research Resources under award number 1 C06 RR12463-01, VA Merit Review Award IBX004121A from the United States Department of Veterans Affairs Biomedical Laboratory Research and Development Service, the DOD Prostate Cancer Idea Development Award (W81XWH-15-1-0558), the DOD Lung Cancer Investigator-Initiated Translational Research Award (W81XWH-18-1-0440), the DOD Peer Reviewed Cancer Research Program (W81XWH-16-1-0329), the Ohio Third Frontier Technology Validation Fund, the Wallace H. Coulter Foundation Program in the Department of Biomedical Engineering and the Clinical and Translational Science Award Program (CTSA) at Case Western Reserve University.Funder: Susan G Komen Foundation (CCR CCR18547966) and a Young Investigator Grant from the Breast Cancer Alliance.Funder: The Canadian Cancer SocietyFunder: Breast Cancer Research Foundation (BCRF), Grant No. 17-194Abstract: Assessment of tumor-infiltrating lymphocytes (TILs) is increasingly recognized as an integral part of the prognostic workflow in triple-negative (TNBC) and HER2-positive breast cancer, as well as many other solid tumors. This recognition has come about thanks to standardized visual reporting guidelines, which helped to reduce inter-reader variability. Now, there are ripe opportunities to employ computational methods that extract spatio-morphologic predictive features, enabling computer-aided diagnostics. We detail the benefits of computational TILs assessment, the readiness of TILs scoring for computational assessment, and outline considerations for overcoming key barriers to clinical translation in this arena. Specifically, we discuss: 1. ensuring computational workflows closely capture visual guidelines and standards; 2. challenges and thoughts standards for assessment of algorithms including training, preanalytical, analytical, and clinical validation; 3. perspectives on how to realize the potential of machine learning models and to overcome the perceptual and practical limits of visual scoring
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Pitfalls in assessing stromal tumor infiltrating lymphocytes (sTILs) in breast cancer
Abstract: Stromal tumor-infiltrating lymphocytes (sTILs) are important prognostic and predictive biomarkers in triple-negative (TNBC) and HER2-positive breast cancer. Incorporating sTILs into clinical practice necessitates reproducible assessment. Previously developed standardized scoring guidelines have been widely embraced by the clinical and research communities. We evaluated sources of variability in sTIL assessment by pathologists in three previous sTIL ring studies. We identify common challenges and evaluate impact of discrepancies on outcome estimates in early TNBC using a newly-developed prognostic tool. Discordant sTIL assessment is driven by heterogeneity in lymphocyte distribution. Additional factors include: technical slide-related issues; scoring outside the tumor boundary; tumors with minimal assessable stroma; including lymphocytes associated with other structures; and including other inflammatory cells. Small variations in sTIL assessment modestly alter risk estimation in early TNBC but have the potential to affect treatment selection if cutpoints are employed. Scoring and averaging multiple areas, as well as use of reference images, improve consistency of sTIL evaluation. Moreover, to assist in avoiding the pitfalls identified in this analysis, we developed an educational resource available at www.tilsinbreastcancer.org/pitfalls