871 research outputs found
Prevalence and independent risk factors for hearing loss in NICU infants
Aim: To determine the prevalence and independent relationship between hearing loss and risk factors in a representative neonatal intensive care unit (NICU) population. Methods: Automated auditory brainstem response (AABR) hearing screening has been introduced since 1998 in the Dutch NICUs. After a second AABR failure, diagnostic ABR was used to establish diagnosis of hearing loss. Newborns who died before the age of 3 months were excluded. In the present study only the NICU infants who were born with a gestational age <30 weeks and/or a birth weight <1000 g between October 1, 1998 and January 1, 2002 were included. Risk factors included in the study were familial hearing loss, in utero infections, craniofacial anomalies, birth weight <1500g, hyperbilirubinemia, ototoxic medications, cerebral complications, severe birth asphyxia, assisted ventilation ≥5 days and syndromes. Results: A nationwide cohort of 2186 newborns were included. Mean gestational age was 28.5 weeks (SD 1.6) and mean birth weight was 1039 g (SD 256). Prevalence of uni- or bilateral hearing loss was 3.2% (71/2186; 95% CI 2.6-4.1). Multivariate analysis revealed that the only independent risk factors for hearing loss were severe birth asphyxia (OR 1.7; 95% CI 1.0-2.7) and assisted ventilation ≥5 days (OR 3.6; 95% CI 2.1-6.0). Conclusion: The prevalence of hearing loss in a representative NICU population was 3.2%. Independent risk factors for hearing loss were severe birth asphyxia and assisted ventilation ≥5 days.</p
Improving green manure quality with phosphate rocks in Ontario Canada
Phosphate rock (PR) was applied to one conventional and two organic dairy fields and planted with buckwheat (Fagopyrum esculentum) as a green manure crop. In total, five types of PR were applied at three application rates in order to determine the yield, concentration of P in the aboveground tissue and the P uptake of buckwheat. It was found that PR of relatively high carbonate substitution and small particle diameter could increase buckwheat tissue concentrations to a quality such that mineralization of the buckwheat mulch could occur. Buckwheat mulch and residual PR increased soil P flux as determined by anion exchange membranes in situ in the following spring. This provides evidence that buckwheat of high P quality has the potential to supply P to a subsequent crop
The correlations between the spin frequencies and kHz QPOs of Neutron Stars in LMXBs
We studied the correlations between spin frequencies and kilohertz
quasi-periodic oscillations (kHz QPOs) in neutron star low mass X-ray binaries.
The updated data of kHz QPOs and spin frequencies are statistically analyzed.
We found that when two simultaneous kHz QPOs are present in the power spectrum,
the minimum frequency of upper kHz QPO is at least 1.3 times larger than the
spin frequency, i.e. \nu_{s}<\nu_{2min}/1.3. We also found that the average kHz
QPO peak separation in 6 Atoll sources anti-correlates with the spin frequency
in the form \lan\dn\ran = -(0.19\pm0.05)\ns+(389.40\pm21.67)Hz. If we shifted
this correlation in the direction of the peak separation by a factor of 1.5,
this correlation matches the data points of the two accretion powered
millisecond X-ray pulsars, SAX J1808.4-3658 and XTE J1807-294.Comment: 4 pages, 2 figures, accepted for publication in A&
Hearing loss by week of gestation and birth weight in very preterm neonates
OBJECTIVE: To gain insight into health and related costs associated with very preterm births, one needs accurate information about the prevalence of the disabling conditions, including neonatal hearing loss (NHL).STUDY DESIGN: We assessed the prevalence of NHL by week of gestation and categories of birth weight in very preterm neonates. Results of the 2-stage Automated Auditory Brainstem Response nationwide Newborn Hearing Screening Program in Dutch Neonatal Intensive Care Units and diagnostic examinations were centrally registered between October 1998 and December 2012 and included in this study. NHL was defined as impaired when the neonate conventional Auditory Brainstem Response level exceeded 35 dB near Hearing Level at diagnostic examination. Birth weight was stratified into <750 g, 750-999 g, 1000-1249 g, 1250-1499 g, and ≥ 1500 g, and by small for gestational age (SGA; <10th percentile) vs appropriate for gestational age. Logistic regression analyses and recursive partitioning were performed.RESULTS: In total, 18,564 very preterm neonates were eligible. The prevalence of NHL consistently increased with decreasing week of gestation (1.2%-7.5% from 31 to 24 weeks) and decreasing birth weight (1.4%-4.8% from ≥ 1500 g to <750 g, all P < .002). Most vulnerable to NHL were girls <28 weeks, boys <30 weeks, and SGA neonates. The SGA effect started at 27 weeks.CONCLUSIONS: Gestational age and birth weight quantify the risk of NHL. This information can be used at the individual level for parent counseling and at the population level for medical decision making.</p
Purification, crystallization and preliminary X-ray analysis of the lytic transglycosylase MltA from Escherichia coli
The lytic transglycosylase MltA from Escherichia coli with its membrane anchor and signal sequence deleted has been purified to homogeneity by means of cation-exchange chromatography. The enzyme was crystallized using the hanging-drop vapour-diffusion method. The crystals belong to space group P3(1)21 or P3(2)21, with unit-cell parameters a=b=103.70, c=109.84 Angstrom and one molecule per asymmetric unit. Crystals diffract to 2.2 Angstrom resolution on a synchrotron-radiation source
Evaluation of Treatment Thresholds for Unconjugated Hyperbilirubinemia in Preterm Infants:Effects on Serum Bilirubin and on Hearing Loss?
Background: Severe unconjugated hyperbilirubinemia may cause deafness. In the Netherlands, 25% lower total serum bilirubin (TSB) treatment thresholds were recently implemented for preterm infants.Objective: To determine the rate of hearing loss in jaundiced preterms treated at high or at low TSB thresholds.Design/Methods: In this retrospective study conducted at two neonatal intensive care units in the Netherlands, we included preterms (gestational age 35 dB).Results: There were 479 patients in the high and 144 in the low threshold group. Both groups had similar gestational ages (29.5 weeks) and birth weights (1300 g). Mean and mean peak TSB levels were significantly lower after the implementation of the novel thresholds: 152 +/- 43 mu mol/L and 212 +/- 52 mu mol/L versus 131 +/- 37 mu mol/L and 188 +/- 46 mu mol/L for the high versus low thresholds, respectively (PConclusions: Implementation of lower treatment thresholds resulted in reduced mean and peak TSB levels. The incidence of hearing impairment in preterms with a gestational age</p
Glucosuria as an early marker of late-onset sepsis in preterms:a prospective cohort study
Background: Early and accurate diagnosis of late-onset sepsis (LONS) in preterm infants is difficult since presenting signs are subtle and non-specific. Because neonatal sepsis may be accompanied by glucose intolerance and glucosuria, we hypothesized that glucosuria may be associated with LONS in preterms, in an early stage. We aim to evaluate the association of glucosuria and late-onset neonatal sepsis (LONS) in preterm infants, in an attempt to improve early and accurate diagnosis of LONS. Methods: We performed a prospective observational cohort study in 316 preterms ( Results: Glucosuria was found in 65.8 % of 316 preterm patients, and sepsis was suspected 157 times in 123 patients. LONS was found in 47.1 % of 157 suspected episodes. The presence of glucosuria was associated with LONS (OR 2.59, 95 % CI 1.24-5.43, p = 0.012) with sensitivity 69.0 % and specificity 53.8 % (Likelihoodratio 1.49). After adjustment for gestational age, birth weight, and postnatal age, this association weakened and was no longer significant (adjusted OR 2.16; 95 % CI 0.99-1.85, p = 0.055). An increase in glucosuria 48-24 h before onset of symptoms was not associated with LONS. Conclusion: In preterms glucosuria is associated with LONS within 24 h, however this association is too weak to be of diagnostic value
Byggmeister Test Home: Cold Climate Multifamily Masonry Building Condition Assessment and Retrofit Analysis
This report describes a retrofit project undertaken by Building Science Corporation and partner Byggmeister on a multifamily brick row house located in Jamaica Plain, MA. This project studied the row house to determine the right combination of energy efficiency measures that are feasible, affordable, and suitable for this type of construction and acceptable to homeowners
The atoll source states of 4U 1608-52
We have studied the atoll source 4U 1608-52 using a large data set obtained
with the Rossi X-ray Timing Explorer. We find that the timing properties of 4U
1608-52 are almost exactly identical to those of the atoll sources 4U 0614+09
and 4U 1728-34 despite the fact that contrary to these sources 4U 1608-52 is a
transient covering two orders of magnitude in luminosity. The frequencies of
the variability components of these three sources follow a universal scheme
when plotted versus the frequency of the upper kilohertz QPO, suggesting a very
similar accretion flow configuration. If we plot the Z sources on this scheme
only the lower kilohertz QPO and HBO follow identical relations. Using the
mutual relations between the frequencies of the variability components we
tested several models; the transition layer model, the sonic point beat
frequency model, and the relativistic precession model. None of these models
described the data satisfactory. Recently, it has been suggested that the atoll
sources (among them 4U 1608-52) trace out similar three-branch patterns as the
Z sources in the color-color diagram. We have studied the relation between the
power spectral properties and the position of 4U 1608-52 in the color-color
diagram and conclude that the timing behavior is not consistent with the idea
that 4U 1608-52 traces out a three-branched Z shape in the color-color diagram
along which the timing properties vary gradually, as Z sources do.Comment: 43 pages, 16 figures, ApJ accepte
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