39 research outputs found
Electron-beam-assisted superplastic shaping of nanoscale amorphous silica
At room temperature, glasses are known to be brittle
and fracture upon deformation. Zheng et al. show that, by exposing amorphous silica
nanostructures to a low-intensity electron beam, it is possible to achieve dramatic shape
changes, including a superplastic elongation of 200% for nanowires
Review of literature on medical mycology in the philippines, 1955–1962
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43278/1/11046_2005_Article_BF02054886.pd
Cabbage and fermented vegetables : From death rate heterogeneity in countries to candidates for mitigation strategies of severe COVID-19
Large differences in COVID-19 death rates exist between countries and between regions of the same country. Some very low death rate countries such as Eastern Asia, Central Europe, or the Balkans have a common feature of eating large quantities of fermented foods. Although biases exist when examining ecological studies, fermented vegetables or cabbage have been associated with low death rates in European countries. SARS-CoV-2 binds to its receptor, the angiotensin-converting enzyme 2 (ACE2). As a result of SARS-CoV-2 binding, ACE2 downregulation enhances the angiotensin II receptor type 1 (AT(1)R) axis associated with oxidative stress. This leads to insulin resistance as well as lung and endothelial damage, two severe outcomes of COVID-19. The nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is the most potent antioxidant in humans and can block in particular the AT(1)R axis. Cabbage contains precursors of sulforaphane, the most active natural activator of Nrf2. Fermented vegetables contain many lactobacilli, which are also potent Nrf2 activators. Three examples are: kimchi in Korea, westernized foods, and the slum paradox. It is proposed that fermented cabbage is a proof-of-concept of dietary manipulations that may enhance Nrf2-associated antioxidant effects, helpful in mitigating COVID-19 severity.Peer reviewe
Nrf2-interacting nutrients and COVID-19 : time for research to develop adaptation strategies
There are large between- and within-country variations in COVID-19 death rates. Some very low death rate settings such as Eastern Asia, Central Europe, the Balkans and Africa have a common feature of eating large quantities of fermented foods whose intake is associated with the activation of the Nrf2 (Nuclear factor (erythroid-derived 2)-like 2) anti-oxidant transcription factor. There are many Nrf2-interacting nutrients (berberine, curcumin, epigallocatechin gallate, genistein, quercetin, resveratrol, sulforaphane) that all act similarly to reduce insulin resistance, endothelial damage, lung injury and cytokine storm. They also act on the same mechanisms (mTOR: Mammalian target of rapamycin, PPAR gamma:Peroxisome proliferator-activated receptor, NF kappa B: Nuclear factor kappa B, ERK: Extracellular signal-regulated kinases and eIF2 alpha:Elongation initiation factor 2 alpha). They may as a result be important in mitigating the severity of COVID-19, acting through the endoplasmic reticulum stress or ACE-Angiotensin-II-AT(1)R axis (AT(1)R) pathway. Many Nrf2-interacting nutrients are also interacting with TRPA1 and/or TRPV1. Interestingly, geographical areas with very low COVID-19 mortality are those with the lowest prevalence of obesity (Sub-Saharan Africa and Asia). It is tempting to propose that Nrf2-interacting foods and nutrients can re-balance insulin resistance and have a significant effect on COVID-19 severity. It is therefore possible that the intake of these foods may restore an optimal natural balance for the Nrf2 pathway and may be of interest in the mitigation of COVID-19 severity
Structural characterization and luminescence of porous single crystalline ZnO nanodisks with sponge-like morphology
We report the synthesis of porous single crystalline ZnO nanodisks with sponge-like morphology through a wet chemical approach. To our best knowledge, this is the first report about highly porous single crystalline nanodisks of ZnO with an average diameter of ∼100 nm. The ZnO nanodisks exhibit strong visible (bluegreen) light emission on UV excitation. Scanning Transmission Electron Microcopy (STEM), High-Resolution Transmission Electron Microscopy (HRTEM), and Selected Area Electron Diffraction (SAED) were performed to confirm that the nanodisks are single crystalline and porous in nature. The porosity of the nanodisks gives them the sponge-like appearance. Energy Dispersive X-ray Spectrometry (EDS) and Electron Energy Loss Spectrometry (EELS) analysis of the nanodisks together with high-resolution electron microscopy and photoluminescence measurements were used to determine the cause of the visible emission and its relation to the sponge-like morphology and growth mechanism. The larger surface area to volume ratio of these sponge-like nanostructures makes them very attractive for applications like biochemical sensors and solar cells. © 2008 American Chemical Society
Structural study of the acute effect of Karwinskia humboldtiana on cerebral motor cortex, hippocampus, and caudate nucleus of the rat
We report the synthesis of porous single crystalline ZnO nanodisks with sponge-like morphology through a wet chemical approach. To our best knowledge, this is the first report about highly porous single crystalline nanodisks of ZnO with an average diameter of ?100 nm. The ZnO nanodisks exhibit strong visible (bluegreen) light emission on UV excitation. Scanning Transmission Electron Microcopy (STEM), High-Resolution Transmission Electron Microscopy (HRTEM), and Selected Area Electron Diffraction (SAED) were performed to confirm that the nanodisks are single crystalline and porous in nature. The porosity of the nanodisks gives them the sponge-like appearance. Energy Dispersive X-ray Spectrometry (EDS) and Electron Energy Loss Spectrometry (EELS) analysis of the nanodisks together with high-resolution electron microscopy and photoluminescence measurements were used to determine the cause of the visible emission and its relation to the sponge-like morphology and growth mechanism. The larger surface area to volume ratio of these sponge-like nanostructures makes them very attractive for applications like biochemical sensors and solar cells. " 2008 American Chemical Society.",,,,,,"10.1021/jp0765704",,,"http://hdl.handle.net/20.500.12104/44787","http://www.scopus.com/inward/record.url?eid=2-s2.0-38549168402&partnerID=40&md5=d46ef308181dc0f331f67ac736078c5
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
Karrikin (KAR) molecules found in smoke stimulate seed germination of many plant species that emerge after fire. Genetic studies in Arabidopsis thaliana have identified core components of the KAR signaling pathway, including an α/β-hydrolase, KARRIKIN INSENSITIVE2 (KAI2), that is required for KAR responses. Although KAI2 is often considered a KAR receptor, recent evidence suggests that KARs may require metabolism to become bioactive signals. In addition to sensing KARs or a KAR-derived signal, KAI2 is thought to recognize an unknown endogenous signal, KAI2 ligand (KL). We generated loss-of-function mutations in KARRIKIN-UP-REGULATED F-BOX1 (KUF1), which is a transcriptional marker of KAR/KL signaling in A. thaliana and other plants. The kuf1 mutant in Arabidopsis shows several phenotypes that are consistent with enhanced activity of the KAI2 pathway, including reduced hypocotyl elongation, enhanced cotyledon expansion in light-grown seedlings, increased root hair density and elongation, and differential expression of KAR/KL-responsive transcriptional markers. Seedling phenotypes of kuf1 are dependent on KAI2 and its signaling partner MORE AXILLARY GROWTH2 (MAX2). Furthermore, kuf1 mutants are hypersensitive to KAR(1), but not to other molecules that can signal through KAI2 such as GR24. This implies that kuf1 does not increase the overall responsiveness of the KAI2-dependent signaling pathway, but specifically affects the ability of KAI2 to detect certain signals. We hypothesize that KUF1 imposes feedback inhibition of KL biosynthesis and KAR(1) metabolism. As an F-box protein, KUF1 likely participates in an E3 ubiquitin ligase complex that imposes this regulation through polyubiquitylation of a protein target(s)
Real-time intraoperative monitoring of blood coagulability via coherence-gated light scattering
When characterizing dynamic processes, ergodicity - that is, the equivalence of time averages and of averages over a system\u27s possible microstates - is often invoked. Yet many complex social, economic and material systems are such that practical observations cannot survey the entire ensemble of microstates. In the case of non-ergodic fluids, their slow structural dynamics makes such an approach prohibitive. Blood is a prominent example of a non-ergodic, complex fluid for which today\u27s standards for coagulation tests in vivo are chemically induced offline assays. Here, we show that heterodyne amplification - that is, amplification of a signal by frequency conversion - combined with suitable control of spatiotemporal coherence permits measurements of non-stationary dynamics in non-ergodic, complex media. By taking advantage of this approach, we developed an optical-fibre-based tool that can be directly incorporated into standard vascular-access devices for real-time monitoring of blood coagulability in the operating room