4,692 research outputs found
Cooling electrons from 1 K to 400 mK with V-based nanorefrigerators
The fabrication and operation of V-based superconducting nanorefrigerators is
reported. Specifically, electrons in an Al island are cooled thanks to
hot-quasiparticle extraction provided by tunnel-coupled V electrodes.
Electronic temperature reduction down to 400 mK starting from 1 K is
demonstrated with a cooling power ~20 pW at 1 K for a junction area of 0.3
micron^2. The present architecture extends to higher temperatures refrigeration
based on tunneling between superconductors and paves the way to the
implementation of a multi-stage on-chip cooling scheme operating from above 1 K
down to the mK regime.Comment: 3+ pages, 4 color figure
Knowledge, attitudes, and behavior concerning dental trauma among parents of children attending primary school
BACKGROUND: Traumatic dental injuries occur frequently in children and adolescents. The purpose of the present study is to examine the levels of knowledge and behaviors regarding dental trauma among parents of children attending primary schools in the Apulia region of Italy.
METHODS: The study was carried out using an anonymous questionnaire with closed answers distributed to 2,775 parents who were enrolled based on the entire regional school population. Analyses were conducted using the PROC CORRESP (procedure to perform multiple correspondence analysis) and PROC FASTCLUS (procedure to perform cluster analysis). Statistical significance was set at p-value <0.05.
RESULTS: A total 15.5% of the sample reported that their children had experienced dental trauma. Overall, 53.8% of respondents stated that they knew what to do in cases of dental injury. Regarding the time limit within which it is possible to usefully intervene for dental trauma, 56.8% of respondents indicated "within 30 minutes". Of the total sample, 56.5% knew how to preserve a displaced tooth. A total 62.9% of parents felt it was appropriate for their children to use dental guards during sports activities. The multivariate analysis showed that wrong knowledge are distributed among all kinds of subject. Parents with previous experience of dental trauma referred right behaviours, instead weak knowledge and wrong behaviours are associated with parents that easily worried for dental events.
CONCLUSIONS: This study showed that most parents reported no experience of dental trauma in their children, and half of them did not know what to do in case of traumatic dental injury and they would intervene within 30 minutes, suggesting that dental trauma may trigger panic. However, they did not have the information needed to best assist the affected child. Motivating parents to assume a preventive approach towards dental trauma may produce positive changes that would result an increase of long-term health benefits among both parents and children
The contribution of age structure to cell population responses to targeted therapeutics
Cells grown in culture act as a model system for analyzing the effects of
anticancer compounds, which may affect cell behavior in a cell cycle
position-dependent manner. Cell synchronization techniques have been generally
employed to minimize the variation in cell cycle position. However,
synchronization techniques are cumbersome and imprecise and the agents used to
synchronize the cells potentially have other unknown effects on the cells. An
alternative approach is to determine the age structure in the population and
account for the cell cycle positional effects post hoc. Here we provide a
formalism to use quantifiable age distributions from live cell microscopy
experiments to parameterize an age-structured model of cell population
response
Needle revision with 5-fluorouracil for the treatment of ahmed glaucoma valve filtering blebs 5-fluoruracil needling revision can be a useful and safe tool in the management of failing ahmed glaucoma valve filtering blebs
Quality of Life in Glaucoma: A Review of the Literature
The ultimate goal of glaucoma management is the preservation of patients’ visual function and quality of life (QoL). The disease itself as well as the medical or surgical treatment can have an enormous impact on a patient’s QoL. Even the mere diagnosis of a chronic, irreversible, potentially blinding disorder can adversely affect the patient’s sense of well-being and QoL by eliciting significant anxiety. Patients with primary open-angle glaucoma rarely present with visual symptoms, at least early in the course of the disease. A better understanding of patient-reported QoL can improve patient–physician interaction and enhance treatment adherence by customizing treatment options based on individual patient profile, thus optimizing long-term prognosis. These aspects are summarized and critically appraised in this article
Paradoxical movement of the lower ribcage at rest and during exercise in COPD patients
Paradoxical inward displacement of the costal margin during inspiration is observed in many chronic obstructive pulmonary disease patients at rest but its importance is unclear.The current authors studied 20 patients (forced expiratory volume in one second 32.6 +/- 11.7, functional residual capacity 186 +/- 32% predicted) and 10 healthy controls at rest and during symptom-limited incremental exercise. With optoelectronic plethysmography, the phase shift between pulmonary and abdominal ribcage volumes and the percentage of inspiratory time the ribcage compartments moved in opposite directions were quantified, using control data to define the normal range of movement.Eight patients showed lower ribcage inspiratory paradox at rest (P+), while 12 patients did not (P-). This was unrelated to resting lung function or exercise tolerance. Total end-expiratory chest wall volume (EEVcw) increased immediately when exercise began in P+ patients, but later in exercise in P- patients. This difference in EEVcw was mainly due to a greater increase of end-expiratory pulmonary ribcage volume in P+ patients. During exercise, dyspnoea increased similarly in the two groups, while leg effort increased more markedly in the patients without paradox.In conclusion, lower ribcage paradox at rest is reproducible and associated with early-onset hyperinflation of the chest wall and predominant dyspnoea at end-exercise. When paradox is absent, the sense of leg effort becomes a more important symptom limiting exercise.British Lung FoundationEuropean Respiratory Society (ERS)ERS COEDPolitecn Milan, TBM Lab, Dipartimento Bioingn, I-20133 Milan, ItalyUniv Liverpool, Ctr Clin Sci, Univ Hosp Aintree, Liverpool L69 3BX, Merseyside, EnglandUniversidade Federal de São Paulo, São Paulo, BrazilUniversidade Federal de São Paulo, São Paulo, BrazilEuropean Respiratory Society (ERS): 69Web of Scienc
Impact of remnant vital tissue after locoregional treatment and liver transplant in hepatocellular cancer patients. A multicentre cohort study
The role of pathological findings after locoregional treatments as predictors of hepatocellular cancer recurrence after liver transplantation has been poorly addressed. The aim of the study was to identify the role of remnant vital tissue (RVT) of the target lesion in predicting hepatocellular cancer recurrence. Two hundred and seventy-six patients firstly undergoing locoregional treatment and then transplanted between January 2010 and December 2015 in four European Transplant Centres (i.e. Rome Tor Vergata, Birmingham, Brussels and Ancona) were enrolled in the study to investigate the role of pathological response at upfront locoregional treatment. At multivariable Cox regression analysis, RVT ≥2 cm was a strong independent risk factor for post-LT recurrence (HR = 5.6; P < 0.0001). Five-year disease-free survival rates were 60.8%, 80.9% and 95.0% in patients presenting a RVT ≥2 cm vs. 0.1-1.9 vs. no RVT, respectively. When only Milan Criteria-IN patients were analysed, similar results were reported, with 5-year disease-free survival rates of 58.1%, 79.0% and 94.0% in patients presenting a RVT ≥2 cm vs. 0.1-1.9 vs. no RVT, respectively. RVT is an important determinant of tumour recurrence after liver transplantation performed for hepatocellular cancer. Its discriminative power looks to be evident also in a Milan-IN setting, suggesting to more liberally use locoregional treatments also in these patients
Stardust experimental campaign and numerical simulations: influence of obstacles and temperature on dust resuspension in a vacuum vessel under lova
Activated dust mobilization during a Loss of Vacuum Accident (LOVA) is one of the safety concerns for the International Thermonuclear Experimental Reactor (ITER). Intense thermal loads in fusion devices occur during plasma disruptions, edge localized modes and vertical displacement events. They will result in macroscopic erosion of the plasma facing materials and consequent accumulation of activated dust into the ITER vacuum vessel (VV). These kinds of events can cause dust leakage outside the VV that represents a high radiological risk for the workers and the population. A small facility, Small Tank for Aerosol Removal and Dust (STARDUST), was set up at the ENEA Frascati laboratories to perform experiments concerning the dust mobilization in a volume with the initial conditions similar to those existing in ITER VV. The aim of this work was to reproduce a low pressurization rate (300 Pa s−1) LOVA event in a VV due to a small air leakage for two different positions of the leak, at the equatorial port level and at the divertor port level, in order to evaluate the influence of obstacles and walls temperature on dust resuspension during both maintenance (MC) and accident conditions (AC) (T
walls = 25 °C MC, 110 °C AC). The dusts used were tungsten (W), stainless steel 316 (SS316) and carbon (C), similar to those produced inside the vacuum chamber in a fusion reactor when the plasma facing materials vaporize due to the high energy deposition. The experimental campaign has been carried out by introducing inside STARDUST facility an obstacle to simulate the presence of objects, such as divertor. In the obstacle a slit was cut to simulate the limiter–divertor gap inside ITER VV. In this paper experimental campaign results are shown in order to investigate how the divertor and limiter–divertor gap influence dust mobilization into a VV. A two-dimensional (2D) modelling of STARDUST was made using the CFD commercial code FLUENT, in order to get a preliminary overview of the fluid dynamics behaviour during a LOVA event and to justify the mobilization data. In addition, a numerical model was developed to compare numerical results with experimental ones.</jats:p
Characterization of charge collection in CdTe and CZT using the transient current technique
The charge collection properties in different particle sensor materials with
respect to the shape of the generated signals, the electric field within the
detector, the charge carrier mobility and the carrier lifetime are studied with
the transient current technique (TCT). Using the well-known properties of Si as
a reference, the focus is laid on Cadmium-Telluride (CdTe) and
Cadmium-Zinc-Telluride (CZT), which are currently considered as promising
candidates for the efficient detection of X-rays. All measurements are based on
a transient-current technique (TCT) setup, which allows the recording of
current pulses generated by an 241Am alpha-source. These signals will be
interpreted with respect to the build-up of space-charges inside the detector
material and the subsequent deformation of the electric field. Additionally the
influence of different electrode materials (i.e. ohmic or Schottky contacts) on
the current pulse shapes will be treated in the case of CdTe. Finally, the
effects of polarization, i.e. the time-dependent degradation of the detector
signals due to the accumulation of fixed charges within the sensor, are
presented.Comment: 20 pages, 17 figure
Induced pluripotent stem cells in hematology: current and future applications
Reprogramming somatic cells into induced pluripotent stem (iPS) cells is nowadays approaching effectiveness and clinical grade. Potential uses of this technology include predictive toxicology, drug screening, pathogenetic studies and transplantation. Here, we review the basis of current iPS cell technology and potential applications in hematology, ranging from disease modeling of congenital and acquired hemopathies to hematopoietic stem and other blood cell transplantation
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