160 research outputs found
Changes in mechanical behaviour of a glass fibre reinforced epoxy by adding polyamide 6 nanofibres
Interlaminar toughening of resin transfer moulded glass fibre epoxy laminates by polycaprolactone electrospun nanofibres
Renal function in the preterm neonate and the newborn rabbit
Nephrogenesis in the human being proceeds until the 35th week of gestation.
The anatomic immaturity of the kidneys in preterm neonates concurs
with a functional immaturity on glomerular as well as on tubular level.
The studies in this thesis are performed in order to analyse the effect of
extrarenal influences on renal function in the developing kidney. Studies
are in part performed in newborn rabbits before the end of nephrogenesis,
and in part in preterm human neonate
Once-daily versus twice-daily administration of ceftazidime in the preterm infant
Ceftazidime pharmacokinetics in 28 preterm infants (gestational ages, 25.6
to 31.9 weeks) were studied on day 3 of life. Patients with suspected
septicemia were randomized on day 1 of life in two groups. One group (n =
13) was administered 25 mg of ceftazidime per kg of body weight once
daily, and the other (n = 15) was given 25 mg of ceftazidime per kg twice
daily. Both groups also received 25 mg of amoxicillin per kg twice daily.
Blood samples were collected on day 3 of life with an arterial catheter at
0, 0.5, 1, 2, 4, 8, and 12 h after an intravenous bolus injection. An
additional blood sample was taken at 24 h from the group dosed once a day.
High-performance liquid chromatography was used to determine serum
ceftazidime concentrations. The pharmacokinetics of ceftazidime were best
described by using a one-compartment model. The half-life for the
elimination of the drug from serum, apparent volume of distribution, total
body clearance of ceftazidime, and inulin clearance were not significantly
different for both groups. The ceftazidime/inulin clearance ratio was 0.72
for both groups. However, trough concentrations in serum for the
twice-daily group were significantly (P < 0.001) higher (42.0 +/- 13.4
mg/liter) than those for the once-daily group (13.1 +/- 4.7 mg/liter). The
latter concentrations were all still substantially higher than the MIC of
ceftazidime for major neonatal pathogens. We conclude that the currently
recommended dosage of 25 mg of ceftazidime per kg twice daily for preterm
infants with gestational ages below 32 weeks may be adjusted during the
first days of life to one daily dose at 25 mg/kg, provided that for the
empirical treatment of septicemia, amoxicillin at 25 mg/kg is also given
twice daily
Beam-induced Fe nanopillars as tunable domain-wall pinning sites
Focused-electron-beam-induced deposition (FEBID) is employed to create freestanding magnetic nanostructures. By growing Fe nanopillars on top of a perpendicular magnetic domain wall (DW) conduit, pinning of the DWs is observed due to the stray fields emanating from the nanopillar. Furthermore, a different DW pinning behavior is observed between the up and down magnetic states of the pillar, allowing to deduce the switching fields of the pillar in a novel way. The implications of these results are two-fold: not only can 3-dimensional nano-objects be used to control DW motion in applications, it is also proposed that DW motion is a unique tool to probe the magnetic properties of nano-objects
Development and characterization of protein nanohydrogels for food applications
Fundação para a Ciência e Tecnologia, POPH-QREN and FSE (FCT, Portugal)EU Cost Actions FA090
Genetic variants associated with adult blood pressure and kidney function do not affect fetal kidney volume. The Generation R Study
Background: Smaller kidneys with reduced number of nephrons in early life lead to impaired kidney function and risk for hypertension and chronic kidney disease. These associations might be partly explained by common genetic variation. Aims: To assess the associations between common genetic variants, which have recently shown to be associated with blood pressure or kidney function, with fetal kidney volume. Study design: A prospective population based cohort study in Rotterdam, The Netherlands. Subjects: 855 children, followed from early fetal life onwards (born 2003-2005). Predictor: Common genetic variants previously associated with blood pressure or kidney function. Outcome measures: Combined third trimester fetal kidney volume. Results: After taking into account multiple testing, only rs12940887 (near ZNF652) was significantly associated with fetal kidney volume (β: 0.88 (95% CI: 0.40; 1.37) cm 3 per minor allele, P-value<0.001), but the effect showed the opposite direction as expected. The remaining common genetic variants were not associated with fetal kidney volume. We also did not find associations of genetic variants previously shown to affect newborn kidney volume, with third trimester fetal kidney volume. Conclusions: Our results suggest that common genetic variants, associated with kidney function or disease and blood pressure, do not affect the third trimester fetal kidney volume. Further studies are needed to elucidate the mechanisms underlying the associations between small kidney size and increased risks of hypertension and impaired kidney function in adulthood
Reduced renal length and volume 20Â years after very preterm birth
Intrauterine growth retardation is presumed to be associated with decreased renal size and impaired renal function as a result of stunted kidney development and nephron deficit. To study whether very preterm birth also affects renal size at young adulthood, we sonographically measured bipolar kidney length and volume in 51 very premature individuals (<32 weeks of gestation), either small (SGA) or appropriate (AGA) for gestational age (22 SGA and 29 AGA), and 30 full-term controls 20 years after birth. Relative kidney length and volume were calculated. Both absolute and relative left kidney length and volume were significantly lower in SGA and AGA individuals, notably in women. Renal size did not differ between SGA and AGA individuals. In 70% of controls, the left kidney was larger than the right one compared with 40.9% in SGA [relative risk (RR) 1.7; 95% confidence interval (CI) 1.0−3.0] and 48.3% in AGA (RR 1.5; 95% CI 0.9−2.3) individuals. Renal structural anomalies were present in eight prematurely born participants only. Our data suggest that kidney growth is stunted after preterm birth, especially on the left side, and in the female gender
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