279 research outputs found
Stylish UV-C lamp for disinfecting household objects
In this study, UV-C device proved to be a valuable tool for disinfecting household items and enhancing safety for
everyday healt
EARLINET Single Calculus Chain – overview on methodology and strategy
In this paper we describe the EARLINET Single Calculus Chain (SCC), a tool for
the automatic analysis of lidar measurements. The development of this
tool started in the framework of EARLINET-ASOS (European Aerosol
Research Lidar Network – Advanced Sustainable Observation System); it was extended within ACTRIS (Aerosol, Clouds and
Trace gases Research InfraStructure Network), and it is continuing within
ACTRIS-2. The main idea was to develop a data processing chain that allows all
EARLINET stations to retrieve, in a fully automatic way, the aerosol
backscatter and extinction profiles starting from the raw lidar data
of the lidar systems they operate. The calculus subsystem of the SCC
is composed of two modules: a pre-processor module which handles the
raw lidar data and corrects them for instrumental effects and an optical
processing module for the retrieval of aerosol optical products from
the pre-processed data. All input parameters needed to perform the
lidar analysis are stored in a database to keep track of all changes which may occur for any
EARLINET lidar system over the time. The two calculus modules are coordinated and synchronized by an additional module (daemon)
which makes the whole analysis process fully automatic. The end user
can interact with the SCC via a user-friendly web interface.
All SCC modules are developed using open-source and freely available
software packages.
The final products retrieved by the SCC fulfill all requirements of the EARLINET quality assurance
programs on both instrumental and algorithm levels. Moreover, the
manpower needed to provide aerosol optical products is greatly reduced
and thus the near-real-time availability of lidar data is improved.
The high-quality of the SCC products is proven by the good
agreement between the SCC analysis, and the corresponding independent manual
retrievals. Finally, the ability of the SCC to provide high-quality
aerosol optical products is demonstrated for an EARLINET intense
observation period
Wind of change: Better air for microbial environmental control
Background: The COVID19 epidemic highlighted the importance of air in the transmission of pathogens. Air
disinfection is one of the key points to reduce the risk of transmission both in the health sector and in public, civil
and industrial environments. All bacteria and viruses tested to date can be inactivated by UV-C rays. Laboratory
tested UV-C systems are increasingly popular and proposed as effective technologies for air purification; few
studies have evaluated their performance in populated indoor environments. The aim of this investigation was to
evaluate the effectiveness of a UV-C disinfection system for air in a real working context.
Methods: This experimental study was conducted between December 2020 and February 2021 in an office of the
Department of Molecular and Developmental Medicine of the University of Siena, Italy. A pre-final version air
purifier (Cleaning Air T12), capable of treating 210 m3/h of air, was first tested for its ability to filter particulates
and reduce microbial air contamination in the absence of people. Subsequently, the experiments were conducted
in the presence of 3–5 subjects who worked for several hours in an office. During the tests, microbiological
samples of air were collected in real time, switching the system on and off periodically. Air samples were
collected and incubated on Petri dishes at 36 ◦C and 22 ◦C. Statistical analysis was performed with Stata 16
software assuming a significance level of 95%. An interpolating model was identified to describe the dynamics of
contamination reduction when the device operates.
Results: Preliminary tests showed a significant 62.5% reduction in Colony-Forming Units (CFUs) with 36 ◦C
incubation. Reductions in the particulate component were also observed. In the main test, comparison of CFU
data, between the device-on phase (90 min) and the subsequent device-off phase (60 min), showed statistically
significant increase (p = 0.001) of environmental contamination passing from a mean of 86.6 (65.8–107.4) to
171.1 (143.9–198.3) CFU/m3, that is a rise of about 100%. The interpolating model exhibited a good fit of CFU
reduction trend with the device on.
Conclusions: The system, which mainly uses UV-C lamps for disinfection, was able to significantly reduce envi-
ronmental and human contamination in real time. Experimental tests have shown that as soon as the device is
switched off, after at least half an hour of operation, the healthiness of the air decreases drastically within 10
minutes, bringing the airborne microbial contamination (induced by the presence of operators in the environ-
ment) to levels even higher than 150% of the last value with the device on. Re-engineering strategies for system
improvement were also discusse
Safer school with near-UV technology: novel applications for environmental hygiene
Systems capable of disinfecting air and surfaces could reduce the risk of infectious diseases transmission. Aim: to evalu-ate the effectiveness of near-UV LED ceiling lamps, with a wavelength of 405 nm, in improving environmental hygiene. Between November and December 2020, we conducted an experimental study having a pre-post design in a kindergarten room in Siena where 4 ceiling lamps with 405 nm LED technology were installed. Twice per day, sampling was performed before (T0) and after treatment with near-UV (T1). We used between 8 and 12 pairs of contact plates to sample at various random spots each day. Air samplings were also performed. The plates were incubated at 22 and 36 degrees C. Significance was set at 95% (p < 0.05). The mean level of Colony Forming Unit (CFU) at T(0) was 249 (95% CI 193.1 - 305.0) at 36 degrees C and 535.2 (374.3 - 696.1) at 22 degrees C. The reduction was significant at T(1): by 65% at 36 degrees C and, 72% at 22 degrees C. Also, for air contamination: 95.3% (98.4 & mdash;92.3). A dose threshold of about 5 J/cm2 was identified to have an 80% CFU abatement and remains nearly constant. The advantage of being able to use this technology in the presence of people is very important in the context of controlling environmental contamination. © 2023, The Author(s)
From dislocation nucleation to dislocation multiplication in ceramic nanoparticle
Magnesium oxide nanocubes are compressed along the [001] direction in situ in the transmission electron microscope. Incipient plasticity in the smaller samples is characterized by the nucleation of few 1/2{110}
dislocations while a larger number of line defects is observed in larger nanocubes. Yield and flow stresses scattered stochastically above a minimum value varying as the inverse of the sample size. The upper bound is given by the reduced number of dislocation sources. Such size-dependent behaviour is justified by a detailed statistical analysis and is fully explained by the deformation mechanism
Intermittent dislocation flow in viscoplastic deformation
The viscoplastic deformation (creep) of crystalline materials under constant
stress involves the motion of a large number of interacting dislocations.
Analytical methods and sophisticated `dislocation-dynamics' simulations have
proved very effective in the study of dislocation patterning, and have led to
macroscopic constitutive laws of plastic deformation. Yet, a statistical
analysis of the dynamics of an assembly of interacting dislocations has not
hitherto been performed. Here we report acoustic emission measurements on
stressed ice single crystals, the results of which indicate that dislocations
move in a scale-free intermittent fashion. This result is confirmed by
numerical simulations of a model of interacting dislocations that successfully
reproduces the main features of the experiment. We find that dislocations
generate a slowly evolving configuration landscape which coexists with rapid
collective rearrangements. These rearrangements involve a comparatively small
fraction of the dislocations and lead to an intermittent behavior of the net
plastic response. This basic dynamical picture appears to be a generic feature
in the deformation of many other materials. Moreover, it should provide a
framework for discussing fundamental aspects of plasticity, that goes beyond
standard mean-field approaches that see plastic deformation as a smooth laminar
flow
Elongation of the Hydrophobic Chain as a Molecular Switch:Discovery of Capsaicin Derivatives and Endogenous Lipids as Potent Transient Receptor Potential Vanilloid Channel 2 Antagonists
The transient receptor potential vanilloid type-2 (TRPV2) protein is a nonselective Ca2+ permeable channel member of the TRPV subfamily, still considered an orphan TRP channel due to the scarcity of available selective and potent pharmacological tools and endogenous modulators. Here we describe the discovery of novel synthetic long-chain capsaicin derivatives as potent TRPV2 antagonists in comparison to the totally inactive capsaicin, the role of their hydrophobic chain, and how the structure-activity relationships of such derivatives led, through a ligand-based approach, to the identification of endogenous long-chain fatty acid ethanolamides or primary amides acting as TRPV2 antagonists. Both synthetic and endogenous antagonists exhibited differential inhibition against known TRPV2 agonists characterized by distinct kinetic profiles. These findings represent the first example of both synthetic and naturally occurring TRPV2 modulators with efficacy in the submicromolar/low-micromolar range, which will be useful for clarifying the physiopathological roles of this receptor, its regulation, and its targeting in pathological conditions.We gratefully acknowledge financial support from Universitat
de Lleida, Ministerio de Educación, Cultura y Deporte and
Banco Santander (Programa UdL-Impuls). The authors are
grateful to the Serveis Cientifictècnics (SCT) of the Universitat
de Lleida for providing us with spectroscopic and chromatographic
facilities. We acknowledge Dr. Alberto Minassi,
Dipartimento di Scienze del Farmaco, Universitàdel Piemonte
Orientale, Novara, Italy, for the kind gift of olvanil
Robotic therapy : Cost, accuracy, and times. New challenges in the neonatal intensive care unit
Background: The medication process in the Neonatal Intensive Care Unit (NICU), can be challenging in terms of costs, time, and the risk of errors. Newborns, especially if born preterm, are more vulnerable to medication errors than adults. Recently, robotic medication compounding has reportedly improved the safety and efficiency of the therapeutic process. In this study, we analyze the advantages of using the I.V. Station\uae system in our NICU, compared to the manual preparation of injectable drugs in terms of accuracy, cost, and time. Method: An in vitro experimental controlled study was conducted to analyze 10 injectable powdered or liquid drugs. Accuracy was calculated within a 5% difference of the bottle weight during different stages of preparation (reconstitution, dilution, and final product). The overall cost of manual and automated preparations were calculated and compared. Descriptive statistics for each step of the process are presented as mean \ub1 standard deviation or median (range). Results: The median error observed during reconstitution, dilution, and final therapy of the drugs prepared by the I.V. Station\uae ranged within \ub15% accuracy, with narrower ranges of error compared to those prepared manually. With increasing preparations, the I.V. Station\uae consumed less materials, reduced costs, decreased preparation time, and optimized the medication process, unlike the manual method. In the 10 drugs analyzed, the time saved from using the I.V. Station\uae ranged from 16 s for acyclovir to 2 h 57 min for teicoplanin, and cost savings varied from 8% for ampicillin to 66% for teicoplanin. These advantages are also capable of continually improving as the total amount of final product increases. Conclusions: The I.V. Station\uae improved the therapeutic process in our NICU. The benefits included increased precision in drug preparation, improved safety, lowered cost, and saved time. These advantages are particularly important in areas such as the NICU, where the I.V. Station\uae could improve the delivery of the high complexity of care and a large amount of intravenous therapy typically required. In addition, these benefits may lead to the reduction in medication errors and improve patient and family care; however, additional studies will be required to confirm this hypothesis
Cyclic nucleotide-dependent relaxation in human umbilical vessels
Umbilical vessels have a low sensitivity to dilate, and this property is speculated to have physiological implications. We aimed to investigate the different relaxing responses of human umbilical arteries (HUAs) and veins (HUVs) to agonists acting through the cAMP and cGMP pathways. Vascular rings were suspended in organ baths for isometric force measurement. Following precontraction with the thromboxane prostanoid (TP) receptor agonist U44069, concentration-response curves to the nitric oxide (NO) donor sodium nitroprusside (SNP), the soluble guanylate cyclase (sGC) stimulator BAY 41-2272, the adenylate cyclase (AC) activator forskolin, the \u3b2-adrenergic receptor agonists isoproterenol (ADRB1), salmeterol (ADRB2), and BRL37344 (ADRB3), and the phosphodiesterase (PDE) inhibitors milrinone (PDE3), rolipram (PDE4), and sildenafil (PDE5) were performed. None of the tested drugs induced a relaxation higher than 30% of the U44069-induced tone. Rings from HUAs and HUVs showed a similar relaxation to forskolin, SNP, PDE inhibitors, and ADRB agonists. BAY 41-2272 was significantly more efficient in relaxing veins than arteries. ADRB agonists evoked weak relaxations (< 20%), which were impaired in endothelium-removed vessels or in the presence of the NO synthase inhibitor L-NAME, sGC inhibitor ODQ. PKA and PKG inhibitors impaired ADBR1-mediated relaxation but did not affect ADRB2-mediated relaxation. ADRB3-mediated relaxation was impaired by PKG inhibition in HUAs and by PKA inhibition in HUVs. Although HUA and HUV rings were relaxed by BRL37344, immunohistochemistry and RT-qPCR analysis showed that, compared to ADRB1 and ADRB2, ADRB3 receptors are weakly or not expressed in umbilical vessels. In conclusion, our study confirmed the low relaxing capacity of HUAs and HUVs from term infants. ADRB-induced relaxation is partially mediated by endothelium-derived NO pathway in human umbilical vessels
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