173 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
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)
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
Abdominal cystic lymphangioma in a term newborn : A case report and update of new treatments
Introduction: Lymphatic malformations are benign anomalies derived from the abnormal development of lymphatic channels. Usually asymptomatic, they can cause compression on adjacent structures or present acute complications (bleeding or infection). Small asymptomatic lesions can be conservatively managed since the possibility of spontaneous regressions is described, while symptomatic lesions require active management. Less invasive therapeutic options are now preferred instead of surgery (sclerotherapy, laser therapy). However, there are not uniform therapeutic protocols. Case Report: We present the case of a term newborn with an abdominal cystic lymphangioma extending from the umbilical to the right inguinal area, reaching the medial surface of the right tight. Despite its large dimensions, which classically request surgical management, the patient was by chance asymptomatic, and the mass did not determine compression on the surrounding organs. Therefore, conservative management was tried, and a close clinical and radiological follow-up was started. This approach permitted a spontaneous regression of the mass and to avoid major surgical intervention. Conclusion: Our purpose is to underline the possibility of conservative management of the major multicystic masses and to focus on less invasive therapeutic options, like sclerotherapy, oral therapy, and laser therapy
Four-dimensional distribution of the 2010 Eyjafjallajökull volcanic cloud over Europe observed by EARLINET
© Author(s) 2013. This work is distributed under the Creative Commons Attribution 3.0 License.The eruption of the Icelandic volcano Eyjafjallaj ökull in April-May 2010 represents a "natural experiment" to study the impact of volcanic emissions on a continental scale. For the first time, quantitative data about the presence, altitude, and layering of the volcanic cloud, in conjunction with optical information, are available for most parts of Europe derived from the observations by the European Aerosol Research Lidar NETwork (EARLINET). Based on multi-wavelength Raman lidar systems, EARLINET is the only instrument worldwide that is able to provide dense time series of high-quality optical data to be used for aerosol typing and for the retrieval of particle microphysical properties as a function of altitude. In this work we show the four-dimensional (4-D) distribution of the Eyjafjallajökull volcanic cloud in the troposphere over Europe as observed by EARLINET during the entire volcanic event (15 April-26 May 2010). All optical properties directly measured (backscatter, extinction, and particle linear depolarization ratio) are stored in the EARLINET database available at www.earlinet.org. A specific relational database providing the volcanic mask over Europe, realized ad hoc for this specific event, has been developed and is available on request at www.earlinet.org. During the first days after the eruption, volcanic particles were detected over Central Europe within a wide range of altitudes, from the upper troposphere down to the local planetary boundary layer (PBL). After 19 April 2010, volcanic particles were detected over southern and south-eastern Europe. During the first half of May (5-15 May), material emitted by the Eyjafjallajökull volcano was detected over Spain and Portugal and then over the Mediterranean and the Balkans. The last observations of the event were recorded until 25 May in Central Europe and in the Eastern Mediterranean area. The 4-D distribution of volcanic aerosol layering and optical properties on European scale reported here provides an unprecedented data set for evaluating satellite data and aerosol dispersion models for this kind of volcanic events.Peer reviewe
Gene signature and immune cell profiling by high-dimensional, single-cell analysis in COVID-19 patients, presenting Low T3 syndrome and coexistent hematological malignancies
BACKGROUND: Low T3 syndrome is frequent in patients admitted to intensive care units for critical illness and pneumonia. It has been reported also in patients with COVID-19, Hodgkin disease and chronic lymphocytic leukemia. We analyzed the clinical relevance of Low T3 syndrome in COVID-19 patients and, in particular, in those with associated hematological malignancies.METHODS: Sixty-two consecutive patients, hospitalized during the first wave of SARS-CoV-2 outbreak in Sant'Andrea University Hospital in Rome, were subdivided in 38 patients (Group A), showing low levels of FT3, and in 24 patients (Group B), with normal FT3 serum values. During the acute phase of the disease, we measured serum, radiologic and clinical disease severity markers and scores, in search of possible correlations with FT3 serum values. In addition, in 6 COVID-19 patients, 4 with Low T3 syndrome, including 2 with a hematological malignancy, and 2 with normal FT3 values, we performed, high-dimensional single-cell analysis by mass cytometry, multiplex cytokine assay and gene expression profiling in peripheral blood mononuclear cells (PBMC).RESULTS: Low FT3 serum values were correlated with increased Absolute Neutrophil Count, NLR and dNLR ratios and with reduced total count of CD3+, CD4+ and CD8+ T cells. Low FT3 values correlated also with increased levels of inflammation, tissue damage and coagulation serum markers as well as with SOFA, LIPI and TSS scores. The CyTOF analysis demonstrated reduction of the effector memory and terminal effector subtypes of the CD4+ T lymphocytes. Multiplex cytokine assay indicates that mainly IL-6, IP-10 and MCAF changes are associated with FT3 serum levels, particularly in patients with coexistent hematological malignancies. Gene expression analysis using Nanostring identified four genes differently expressed involved in host immune response, namely CD38, CD79B, IFIT3 and NLRP3.CONCLUSIONS: Our study demonstrates that low FT3 serum levels are associated with severe COVID-19. Our multi-omics approach suggests that T3 is involved in the immune response in COVID-19 and coexistent hematological malignancy and new possible T3 target genes in these patients have been identified
Atomistic simulations of dislocation mobility in Al, Ni and Al/Mg alloys
Dislocation velocities and mobilities are studied by Molecular Dynamics
simulations for edge and screw dislocations in pure aluminum and nickel, and
edge dislocations in Al-2.5%Mg and Al-5.0%Mg random substitutional alloys using
EAM potentials. In the pure materials, the velocities of all dislocations are
close to linear with the ratio of (applied stress)/(temperature) at low
velocities, consistent with phonon drag models and quantitative agreement with
experiment is obtained for the mobility in Al. At higher velocities, different
behavior is observed. The edge dislocation velocity remains dependent solely on
(applied stress)/(temperature) up to approximately 1.0 MPa/K, and approaches a
plateau velocity that is lower than the smallest "forbidden" speed predicted by
continuum models. In contrast, above a velocity around half of the smallest
continuum wave speed, the screw dislocation damping has a contribution
dependent solely on stress with a functional form close to that predicted by a
radiation damping model of Eshelby. At the highest applied stresses, there are
several regimes of nearly constant (transonic or supersonic) velocity separated
by velocity gaps in the vicinity of forbidden velocities; various modes of
dislocation disintegration and destabilization were also encountered in this
regime. In the alloy systems, there is a temperature- and
concentration-dependent pinning regime where the velocity drops sharply below
the pure metal velocity. Above the pinning regime but at moderate stresses, the
velocity is again linear in (applied stress)/(temperature) but with a lower
mobility than in the pure metal.Comment: PDF, 30 pages including figures, submitted to Modelling Simul. Mater.
Sci. En
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EARLINET observations of the 14-22-May long-range dust transport event during SAMUM 2006: Validation of results from dust transport modelling
We observed a long-range transport event of mineral dust from North Africa to South Europe during the Saharan Mineral
Dust Experiment (SAMUM) 2006. Geometrical and optical properties of that dust plume were determined with Sun
photometer of the Aerosol Robotic Network (AERONET) and Raman lidar near the North African source region, and
with Sun photometers of AERONET and lidars of the European Aerosol Research Lidar Network (EARLINET) in the
far field in Europe. Extinction-to-backscatter ratios of the dust plume over Morocco and Southern Europe do not differ.
Ångstr¨om exponents increase with distance from Morocco. We simulated the transport, and geometrical and optical
properties of the dust plume with a dust transport model. The model results and the experimental data show similar
times regarding the appearance of the dust plume over each EARLINET site. Dust optical depth from the model agrees
in most cases to particle optical depth measured with the Sun photometers. The vertical distribution of the mineral dust
could be satisfactorily reproduced, if we use as benchmark the extinction profiles measured with lidar. In some cases
we find differences. We assume that insufficient vertical resolution of the dust plume in the model calculations is one
reason for these deviations
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