•A voltammetric pH sensor based on an Indoaniline derivative.•Almost Nernstian sensitivity towards pH variations.•High fabrication reproducibility and negligible effect of hysteresis.•Accurate pH ...measurement performed both in in beverages and biological fluids.
Measurement of pH is of fundamental importance in a wide range of environmental, biological and industrial applications. Glass electrode and litmus paper are widely used for this, but the former is difficult to miniaturize, prone to drift and fragile, the latter is inaccurate. This paper describes a pH sensor based on an indoaniline-derivative (4-((4-aminophenyl)imino)-2,6-dimethoxycyclohexa-2,5-dien-1-one), which exploits alternating current voltammetry to measure pH in the range between 2 and 12. The synthetized indoaniline-derivative was not genotoxic (A. cepa assay), and the sensor reliably measured pH in milk, tea, orange juice, blood, urine and saliva. Results were comparable with those obtained with a glass electrode calibrated with certified solutions (maximum relative standard deviation of 3 % and accuracy less than 0.2 pH unit). The sensor had negligible hysteresis, an almost Nernstian sensitivity (56 mV/pH) and was fully functional after a two-month storage. Sensor response showed a limited dependence on temperature (0.14 mV per pH unit and °C) and limited sensitivity to possible interferents such as lithium and sodium ions; its response to these was similar to that of a glass electrode, and was absent for ascorbic acid.
Despite the rapid evolution of industrial technologies in the last decades greatly improved many production processes, several industrial sectors still rely heavily on manual labour. Ship building is ...a possible example, as the fabrication of the hull is still mainly performed by human operators. Styrene, a largely used chemical in many production chains of the polymer industry, is the main component of the fiberglass used for the hulls. In the long term, exposure to styrene is known for its irritating effect, ototoxicity and suspected cancerogenic effects.
In this work, we developed a radial colorimetric dosimeter based on nanostructured materials loaded with potassium permanganate and characterized to finely control the reaction kinetics over an eight hours work shift. Colorimetric dosimeters were successfully tested in a real case scenario by comparing their data with those obtained by sampling styrene with passive absorption tubes and analysing their content by thermal desorption/gas chromatography/mass spectrometry.
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•Radial colorimetric dosimeter for the exposure to styrene.•Changing the substrate properties allows the tuning of the dosimeter’s response.•The colorimetric response was successfully compared with GC/MS analysis.
A Biosensor for the Detection of Acetylcholine and Diazinon Herrera, E. G.; Bonini, A.; Vivaldi, F. ...
2019 41st Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC),
07/2019, Letnik:
2019
Conference Proceeding, Journal Article
Acetylcholine is a neurotransmitter and a neuromodulator found in the autonomic, peripheral and central nervous systems. Diazinon is a pesticide with toxic effects on humans, such as the inhibition ...of acetylcholine. In this paper, a biosensor is proposed for the detection of acetylcholine (range 70 - 1000 μΜ) and diazinon (range 0.3 - 20000 ppb). This biosensor combines a pH-sensitive layer of reduced graphene oxide functionalized with 4-aminobenzoic acid and acetylcholinesterase. This enzyme was immobilized on reduced graphene oxide and it catalyzed the conversion of acetylcholine into choline and acetic acid, locally decreasing the pH value and triggering the sensor response. The limit of detection for the acetylcholine and diazinon were 70 μΜ and 0.3 ppb, respectively.
A graphene-based pH sensor on paper for human plasma and seawater Vivaldi, F.; Bonini, A.; Melai, B. ...
2019 41st Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC),
07/2019, Letnik:
2019
Conference Proceeding, Journal Article
The relevance of pH assessment in clinical analysis, environmental and industrial control, has raised the demand for the development of portable, low cost and easy-to-use monitoring systems. This ...paper proposes a pH sensor printed on a paper support passivated with a solid-ink coating. The sensor exploits the pH sensitivity of a reduced graphene oxide functionalized with 3-(4-aminophenil)propionic acid. The sensor responded in the pH range 4, 10 and had a sensitivity of 46 mV/pH. Tests on human plasma and seawater proved this pH sensor to have similar performances than those of a commercial pH-meter with an uncertainty of 0.1 and 0.2 pH unit in plasma and seawater, respectively.
The BICEP/
Keck
series of experiments target the cosmic microwave background at degree-scale resolution from the South Pole. Over the next few years, the “Stage-3” BICEP Array (BA) telescope will ...improve the program’s frequency coverage and sensitivity to primordial B-mode polarization by an order of magnitude. The first receiver in the array, BA1, began observing at 30/40 GHz in early 2020. The next two receivers, BA2 and BA3, are currently being assembled and will map the southern sky at frequencies ranging from 95 to 150 GHz. Common to all BA receivers is a refractive, on-axis, cryogenic optical design that focuses microwave radiation onto a focal plane populated with antenna-coupled bolometers. High-performance antireflective coatings up to 760 mm in aperture are needed for each element in the optical chain, and must withstand repeated thermal cycles down to 4 K. Here, we present the design and fabrication of the 30/40 GHz anti-reflection coatings for the recently deployed BA1 receiver, with indices matched to its various polyethylene, nylon and alumina optical components. We describe an epoxy coating technique designed for alumina optics, which achieves better than 80% transmission at room temperature. For polyethylene optical elements, we present a new heat-compression approach that allows low-density polytetrafluoroethylene AR layers to reach sub-percent reflected power. We describe the planned use of these methods for the next BA cryostats, which may inform technological choices for future small-aperture telescopes of the CMB-S4 experiment.
Background To describe the incidence of ischemic stroke, short-term mortality, recurrences, and prescription patterns. Methods Data from administrative health databases of the Lombardy Region from ...2002 to 2010 (about 4 million people) were analyzed for stroke incidence and recurrence, mortality, and drug prescriptions after an ischemic stroke. Results A total of 43,352 patients with a first hospital admission for ischemic stroke were identified. During 8 years, stroke incidence decreased from 3.2 of 1000 to 2.4 of 1000 ( P < .001) in people aged 65-74 years, from 7.1 of 1000 to 5.3 of 1000 ( P < .001) at ages 75-84 years and from 11.9 of 1000 to 9.4 of 1000 ( P < .001) at age 85 years or older. Stroke recurrences dropped by 30% (from 10.0% to 7.0%, P < .001) and 30-day mortality rate also decreased. Prescription trends showed linear increase in antiplatelets and lipid-lowering drugs, respectively, from 60.2% to 65.0% ( P < .001) and from 19.1% to 34.6% ( P < .001), whereas antihypertensive prescriptions did not change appreciably. Anticoagulant prescription increased in patients with atrial fibrillation, from 64.8% to 72.1% in the 65-74 years age group, ( P = .004) and from 40.2% to 53.7% in the 75-84 years age group ( P < .001); less than 20% of the 85 years or older age group were treated with anticoagulants ( P < .0001). Conclusions Stroke incidence, recurrence, and 30-day mortality decreased from 2002 to 2010 concomitant with an increase in prescriptions of secondary stroke prevention drugs.
We report DNA- and RNA-like systems built from eight nucleotide "letters" (hence the name "hachimoji") that form four orthogonal pairs. These synthetic systems meet the structural requirements needed ...to support Darwinian evolution, including a polyelectrolyte backbone, predictable thermodynamic stability, and stereoregular building blocks that fit a Schrödinger aperiodic crystal. Measured thermodynamic parameters predict the stability of hachimoji duplexes, allowing hachimoji DNA to increase the information density of natural terran DNA. Three crystal structures show that the synthetic building blocks do not perturb the aperiodic crystal seen in the DNA double helix. Hachimoji DNA was then transcribed to give hachimoji RNA in the form of a functioning fluorescent hachimoji aptamer. These results expand the scope of molecular structures that might support life, including life throughout the cosmos.
Describe COVID-19 information-seeking experiences for culturally and linguistically diverse groups in Sydney, Australia.
Cross-sectional survey, translated into 11 languages; participants recruited ...from March 21 to July 9, 2021. Regression models identified factors associated with difficulty finding easy-to-understand COVID-19 information.
Across 708 participants (88% born overseas, 31% poor English proficiency), difficulty finding easy-to-understand COVID-19 information was rated 4.13 for English (95%CI: 3.85–4.41) and 4.36 for non-English language materials (95%CI: 4.07–4.66) (1 easy to 10 hard). Participants who were older (p < 0.001), had inadequate health literacy (p < 0.001), or poor English proficiency (p < 0.001) found it harder to find easy-to-understand English-language COVID-19 information. Those who had greater difficulty finding easy-to-understand non-English COVID-19 information were younger (p = 0.004), had poor English proficiency (p < 0.001), were university-educated (p = 0.05), and had spent longer living in Australia (p = 0.001). They were more likely to rely on friends and family for COVID-19 information (p = 0.02). There was significant variation in information-seeking experiences across language groups (p’s < 0.001).
Easy-to-understand and accessible COVID-19 information is needed to meet the needs of people in culturally and linguistically diverse communities.
COVID-19 communication efforts must involve working alongside these communities to leverage existing communication channels and tailor messages.
•COVID-19 experience survey 708 people from 11 language groups in Sydney, Australia.•English COVID-19 information less accessible for older people with low health literacy.•Substantial differences in information-seeking experiences across language groups.•People with low health literacy relied more on friends/family and overseas sources.•COVID-19 communication efforts must be tailored for culturally diverse communities.
Improved thermodynamic parameters for prediction of RNA duplex formation are derived from optical melting studies of 90 oligoribonucleotide duplexes containing only Watson−Crick base pairs. To test ...end or base composition effects, new sets of duplexes are included that have identical nearest neighbors, but different base compositions and therefore different ends. Duplexes with terminal GC pairs are more stable than duplexes with the same nearest neighbors but terminal AU pairs. Penalizing terminal AU base pairs by 0.45 kcal/mol relative to terminal GC base pairs significantly improves predictions of ΔG°37 from a nearest-neighbor model. A physical model is suggested in which the differential treatment of AU and GC ends accounts for the dependence of the total number of Watson−Crick hydrogen bonds on the base composition of a duplex. On average, the new parameters predict ΔG°37, ΔH°, ΔS°, and T M within 3.2%, 6.0%, 6.8%, and 1.3 °C, respectively. These predictions are within the limit of the model, based on experimental results for duplexes predicted to have identical thermodynamic parameters.
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