15,886 research outputs found
Standard and Specialized Infant Formulas in Europe: Making, Marketing, and Health Outcomes
Infant formulas are the only suitable substitute for human milk. The most common infant formulas are standard formulas based on cow's milk. In addition, there are formulas for infants showing signs and symptoms of intolerance and for clinical conditions such as allergy, prematurity, and gastrointestinal diseases. A comprehensive review of the literature was made to review the composition of standard and specialized infant formulas and analyze indications for use, real or presumed nutrition differences and properties, and impact on infant growth. A brief consideration on costs is outlined for each formula. Over the past few years, industrial production and advertising of infant formulas have increased. Human milk still remains the most complete source of nutrition for infants and should be continued according to the current recommendations. Few differences exist between infant formulas, both for the nutrition action and the macronutrient/micronutrient composition. Specialized infant formulas have limited indications for use and high costs. The role of the pediatrician is crucial in the management of infant nutrition, promotion of breastfeeding, and prescribing of specialized formulas only in specific clinical conditions
Hospital environment as a reservoir for cross transmission. Cleaning and disinfection procedures
Background. Healthcare associated infections (HAIs) represent a serious problem for public health, as they increase the morbidity and mortality rates, present a relevant financial burden, and significantly contribute to the antimicrobial resistance. Methods. The aim of this review was to investigate the literature about HAIs, with particular reference to hospital environments and the role of cleaning and disinfection procedures. Hospital environments are an essential reservoir for HAIs cross transmission, and the application of appropriate procedures related to hand hygiene and disinfection/sterilization of surfaces and instruments remain key strategies for controlling HAIs. Results. Different procedures, based on the risk associated with the healthcare procedure, are recommended for hand hygiene: washing with soap and water, antiseptic rubbing with alcohol-based disinfectants, antiseptic and surgical hand washing. Environmental surfaces can be treated with different products, and the mostly used are chlorine-based and polyphenolic disinfectant. The reprocessing of instruments is related to their use according to the Spaulding's classification. In addition, scientific evidence demonstrated the great relevance of the "bundles" (small set of practices performed together) in controlling HAIs. Conclusions. Research agenda should include the improvement of well-known effective preventive procedures and the development of new bundles devoted to high-risk procedures and specific microorganisms
Investigating Supergiant Fast X-ray Transients with LOFT
Supergiant Fast X-ray Transients (SFXT) are a class of High-Mass X-ray
Binaries whose optical counterparts are O or B supergiant stars, and whose
X-ray outbursts are ~ 4 orders of magnitude brighter than the quiescent state.
LOFT, the Large Observatory For X-ray Timing, with its coded mask Wide Field
Monitor (WFM) and its 10 m^2 class collimated X-ray Large Area Detector (LAD),
will be able to dramatically deepen the knowledge of this class of sources. It
will provide simultaneous high S/N broad-band and time-resolved spectroscopy in
several intensity states, and long term monitoring that will yield new
determinations of orbital periods, as well as spin periods. We show the results
of an extensive set of simulations performed using previous observational
results of these sources obtained with Swift and XMM-Newton. The WFM will
detect all SFXT flares within its field of view down to a 15-20 mCrab in 5ks.
Our simulations describe the outbursts at several intensities
(F_(2-10keV)=5.9x10^-9 to 5.5x10^-10 erg cm^-2 s^-1), the intermediate and most
common state (10^-11 erg cm^-2 s^-1), and the low state (1.2x10^-12 to 5x10^-13
erg cm^-2 s^-1). We also considered large variations of N_H and the presence of
emission lines, as observed by Swift and XMM-Newton.Comment: Proceedings of the 5th International Symposium on High-Energy
Gamma-Ray Astronomy (Gamma2012), Heidelberg. 4 pages, 3 figures, 1 tabl
Swift monitoring of IGR J16418-4532
We report on the Swift observations of the candidate supergiant fast X-ray
transient (SFXT) IGR J16418-4532, which has an orbital period of ~3.7 d. Our
monitoring, for a total of ~43 ks, spans over three orbits and represents the
most intense and complete sampling along the orbital period of the light curve
of this source. If one assumes a circular orbit, the X-ray emission from this
source can be explained by accretion from a spherically symmetric clumpy wind
from a blue supergiant, composed of clumps with different masses, ranging from
~5x10^16 g to 10^21g.Comment: 4 pages; Proceedings, 5th International Symposium on High-Energy
Gamma-Ray Astronomy, (Gamma2012) Heidelberg, Germany, July 9-13th, 201
Ashtekar Constraint Surface as Projection of Hilbert-Palatini One
The Hilbert-Palatini (HP) Lagrangian of general relativity being written in
terms of selfdual and antiselfdual variables contains Ashtekar Lagrangian
(which governs the dynamics of the selfdual sector of the theory on condition
that the dynamics of antiselfdual sector is not fixed). We show that
nonequivalence of the Ashtekar and HP quantum theories is due to the specific
form (of the "loose relation" type) of constraints which relate self- and
antiselfdual variables so that the procedure of (canonical) quantisation of
such the theory is noncommutative with the procedure of excluding antiselfdual
variables.Comment: 9 pages of LaTeX fil
C ion-implanted TiO2 thin film for photocatalytic applications
Third-generation TiO2 photocatalysts were prepared by implantation of C+ ions into 110 nm thick TiO2 films. An accurate structural investigation was performed by Rutherford backscattering spectrometry, secondary ion mass spectrometry, X-ray diffraction, Raman-luminescence spectroscopy, and UV/VIS optical characterization. The C doping locally modified the TiO2 pure films, lowering the band-gap energy from 3.3 eV to a value of 1.8 eV, making the material sensitive to visible light. The synthesized materials are photocatalytically active in the degradation of organic compounds in water under both UV and visible light irradiation, without the help of any additional thermal treatment. These results increase the understanding of the C-doped titanium dioxide, helpful for future environmental applications. (C) 2015 AIP Publishing LLC
A new method of measuring center-of-mass velocities of radially pulsating stars from high-resolution spectroscopy
We present a radial velocity analysis of 20 solar neighborhood RR Lyrae and 3
Population II Cepheids variables. We obtained high-resolution, moderate-to-high
signal-to-noise ratio spectra for most stars and obtained spectra were covering
different pulsation phases for each star. To estimate the gamma
(center-of-mass) velocities of the program stars, we use two independent
methods. The first, `classic' method is based on RR Lyrae radial velocity curve
templates. The second method is based on the analysis of absorption line
profile asymmetry to determine both the pulsational and the gamma velocities.
This second method is based on the Least Squares Deconvolution (LSD) technique
applied to analyze the line asymmetry that occurs in the spectra. We obtain
measurements of the pulsation component of the radial velocity with an accuracy
of 3.5 km s. The gamma velocity was determined with an accuracy
10 km s, even for those stars having a small number of spectra.
The main advantage of this method is the possibility to get the estimation of
gamma velocity even from one spectroscopic observation with uncertain pulsation
phase. A detailed investigation of the LSD profile asymmetry shows that the
projection factor varies as a function of the pulsation phase -- this is a
key parameter which converts observed spectral line radial velocity variations
into photospheric pulsation velocities. As a byproduct of our study, we present
41 densely-spaced synthetic grids of LSD profile bisectors that are based on
atmospheric models of RR Lyr covering all pulsation phases.Comment: 17 pages, 16 figures, accepted for publication in MNRAS;
doi:10.1093/mnras/stx294
Two years of monitoring Supergiant Fast X-ray Transients with Swift
We present two years of intense Swift monitoring of three SFXTs, IGR
J16479-4514, XTE J1739-302, and IGR J17544-2619 (since October 2007).
Out-of-outburst intensity-based X-ray (0.3-10keV) spectroscopy yields absorbed
power laws with by hard photon indices (G~1-2). Their outburst broad-band
(0.3-150 keV) spectra can be fit well with models typically used to describe
the X-ray emission from accreting NSs in HMXBs. We assess how long each source
spends in each state using a systematic monitoring with a sensitive instrument.
These sources spend 3-5% of the total in bright outbursts. The most probable
flux is 1-2E-11 erg cm^{-2} s^{-1} (2-10 keV, unabsorbed), corresponding to
luminosities in the order of a few 10^{33} to 10^{34} erg s^{-1} (two orders of
magnitude lower than the bright outbursts). The duty-cycle of inactivity is 19,
39, 55%, for IGR J16479-4514, XTE J1739-302, and IGR J17544-2619, respectively.
We present a complete list of BAT on-board detections further confirming the
continued activity of these sources. This demonstrates that true quiescence is
a rare state, and that these transients accrete matter throughout their life at
different rates. X-ray variability is observed at all timescales and
intensities we can probe. Superimposed on the day-to-day variability is
intra-day flaring which involves variations up to one order of magnitude that
can occur down to timescales as short as ~1ks, and whichcan be explained by the
accretion of single clumps composing the donor wind with masses
M_cl~0.3-2x10^{19} g. (Abridged)Comment: Accepted for publication in MNRAS. 17 pages, 11 figures, 8 table
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