Search results for "REF"

Precision and accuracy of single-molecule FRET measurements-a multi-laboratory benchmark study

2018

Single-molecule Forster resonance energy transfer (smFRET) is increasingly being used to determine distances, structures, and dynamics of biomolecules in vitro and in vivo. However, generalized protocols and FRET standards to ensure the reproducibility and accuracy of measurements of FRET efficiencies are currently lacking. Here we report the results of a comparative blind study in which 20 labs determined the FRET efficiencies (E) of several dye-labeled DNA duplexes. Using a unified, straightforward method, we obtained FRET efficiencies with s.d. between +/- 0.02 and +/- 0.05. We suggest experimental and computational procedures for converting FRET efficiencies into accurate distances, and…

2021

Abstract Background Gastric inflammation is a major risk factor for gastric cancer. Current endoscopic methods are not able to efficiently detect and characterize gastric inflammation, leading to a sub-optimal patients’ care. New non-invasive methods are needed. Reflectance mucosal light analysis is of particular interest in this context. The aim of our study was to analyze reflectance light and specific autofluorescence signals, both in humans and in a mouse model of gastritis. Methods We recruited patients undergoing gastroendoscopic procedure during which reflectance was analysed with a multispectral camera. In parallel, the gastritis mouse model of Helicobacter pylori infection was used…

The influence of oxygen and methane on nitrogen fixation in subarctic Sphagnum mosses

2018

Biological nitrogen fixation is an important source of bioavailable nitrogen in Sphagnum dominated peatlands. Sphagnum mosses harbor a diverse microbiome including nitrogen-fixing and methane (CH4) oxidizing bacteria. The inhibitory effect of oxygen on microbial nitrogen fixation is documented for many bacteria. However, the role of nitrogen-fixing methanotrophs in nitrogen supply to Sphagnum peat mosses is not well explored. Here, we investigated the role of both oxygen and methane on nitrogen fixation in subarctic Sphagnum peat mosses. Five species of Sphagnum mosses were sampled from two mesotrophic and three oligotrophic sites within the Lakkasuo peatland in Orivesi, central Finland. Mo…

Maternal Diet and Nutrient Requirements in Pregnancy and Breastfeeding. An Italian Consensus Document.

2016

The importance of lifestyle and dietary habits during pregnancy and breastfeeding, for health of mothers and their offspring, is widely supported by the most recent scientific literature. The consumption of a varied and balanced diet from the preconceptional period is essential to ensure both maternal well-being and pregnancy outcomes. However, the risk of inadequate intakes of specific micronutrients in pregnancy and lactation is high even in the most industrialized countries. This particularly applies to docosahexaenoic acid (DHA), iron, iodine, calcium, folic acid, and vitamin D, also in the Italian population. Moreover, the risk of not reaching the adequate nutrient supply is increased …

Cocaine-induced changes in CX3CL1 and inflammatory signaling pathways in the hippocampus: Association with IL1β

2020

Cocaine induces neuroinflammatory response and interleukin-1 beta (IL1β) is suggested a final effector for many cocaine-induced inflammatory signals. Recently, the chemokine fractalkine (CX3CL1) has been reported to regulate hippocampus-dependent neuroinflammation and synaptic plasticity via CX3C-receptor 1 (CX3CR1), but little is known about the impact of cocaine. This study is mainly focused on the characterization of CX3CL1, IL1β and relevant inflammatory signal transduction pathways in the hippocampus in acute and repeated cocaine-treated male mice. Complementarily, the rewarding properties of cocaine were also assessed in Cx3cr1-knockout (KO) mice using a conditioned place preference (…

Acute effect of intravenously applied alcohol in the human striatal and extrastriatal D2 /D3 dopamine system

2016

Investigations on the acute effects of alcohol in the human mesolimbic dopamine D2 /D3 receptor system have yielded conflicting results. With respect to the effects of alcohol on extrastriatal D2 /D3 dopamine receptors no investigations have been reported yet. Therefore we applied PET imaging using the postsynaptic dopamine D2 /D3 receptor ligand [18 F]fallypride addressing the question, whether intravenously applied alcohol stimulates the extrastriatal and striatal dopamine system. We measured subjective effects of alcohol and made correlation analyses with the striatal and extrastriatal D2 /D3 binding potential. Twenty-four healthy male μ-opioid receptor (OPRM1)118G allele carriers underw…

Survival of Late Pleistocene Hunter-Gatherer Ancestry in the Iberian Peninsula

2019

The Iberian Peninsula in southwestern Europe represents an important test case for the study of human population movements during prehistoric periods. During the Last Glacial Maximum (LGM), the peninsula formed a periglacial refugium [1] for hunter-gatherers (HGs) and thus served as a potential source for the re-peopling of northern latitudes [2]. The post-LGM genetic signature was previously described as a cline from Western HG (WHG) to Eastern HG (EHG), further shaped by later Holocene expansions from the Near East and the North Pontic steppes [3, 4, 5, 6, 7, 8, 9]. Western and central Europe were dominated by ancestry associated with the ∼14,000-year-old individual from Villabruna, Italy…

The habitual nature of food purchases at the supermarket: Implications for policy making

2020

Abstract Supermarkets have become the most important provider of food products worldwide. However, empirical evidence about how consumers make their food purchase decisions in this environment is still scarce. The present field study aimed to: i) explore how people make their in-store food purchases, and ii) identify the information they search for when making those purchases. Consumers (n = 144) were intercepted when entering the facilities of three supermarkets in two Uruguayan cities. They were asked to wear a mobile eye-tracker while they made their purchases as they normally do. The great majority of the consumers bought at least one food product or beverage (92%) and, on average, exam…

Managing adult patients with infectious diseases in emergency departments: international ID-IRI study.

2021

We aimed to explore factors for optimizing antimicrobial treatment in emergency departments. A single-day point prevalence survey was conducted on January 18, 2020, in 53 referral/tertiary hospitals in 22 countries. 1957 (17%) of 11557 patients presenting to EDs had infections. The mean qSOFA score was 0.37 +/- 0.74. Sepsis (qSOFA >= 2) was recorded in 218 (11.1%) patients. The mean qSOFA score was significantly higher in low-middle (1.48 +/- 0.963) compared to upper-middle (0.17 +/- 0.482) and high-income (0.36 +/- 0.714) countries ( P < 0.001). Eight (3.7%) patients with sepsis were treated as outpatients. The most common diagnoses were upper-respiratory (n = 877, 43.3%), lower-respirator…

Entropic Interactions between Two Knots on a Semiflexible Polymer.

2017

Two knots on a string can either be separated or intertwined, and may even pass through each other. At the microscopic scale, such transitions may occur spontaneously, driven by thermal fluctuations, and can be associated with a topological free energy barrier. In this manuscript, we study the respective location of a trefoil ( 3 1 ) and a figure-eight ( 4 1 ) knot on a semiflexible polymer, which is parameterized to model dsDNA in physiological conditions. Two cases are considered: first, end monomers are grafted to two confining walls of varying distance. Free energy profiles and transition barriers are then compared to a subset of free chains, which contain exactly one 3 1 and one 4 1 kn…