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Search Results: 1 - 10 of 313373 matches for " HH H?vels-Gürich "
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Influences of pre-, peri- and postoperative risk factors in neonatal cardiac surgery on neurodevelopmental status in preschool-age children
HH Hvels-Gürich, M-C Seghaye, M Sigler, A Bartl, F Kotlarek, J Neuser, BJ Messmer, G von Bernuth
Critical Care , 2000, DOI: 10.1186/cc676
Abstract: Thirty-three unselected children operated on as neonates with combined deep hypothermic circulatory arrest and low flow cardiopulmonary bypass were examined at an age of 3.0–4.6 years [3.6 ± 0.5 (mean ± standard deviation)]. The control group for developmental outcome consisted of 32 age-matched healthy children, who were 3.0–4.8 years [3.8 ± 0.6 (mean ± standard deviation)] of age. Evaluation of socioeconomic status and a standardised test comprising all areas of child development (Vienna developmental test), including scores of motor and cognitive functions, perception, language, learning and behaviour, were carried out in patients and controls, and clinical neurological status was assessed in patients. Results of patients were related to those of the control group and to pre-, peri-, and postoperative cerebral risk factors of the control group and to pre-, peri-, and postoperative cerebral risk factors as described in the context.Neurological impairment was more frequent (6.1%) than in the normal population. Compared with published norms, complete developmental score and the subtests for motor function, visual perception and visual motor integration, learning and memory, cognitive function, language, and socioemotional functions were not different. Compared with the control group, complete developmental score, cognitive score and language were reduced (P < 0.01), but socioeconomic status was significantly lower in the patient group (P = 0.0001). Motor function was weakly, but significantly inversely related to the duration of circulatory arrest (Pearson correlation coefficient -0.37; P = 0.049), but not to the duration of bypass. The other developmental parameters were not related to the duration of the support techniques. Serum levels of the biochemical marker neuron-specific enolase, although significantly elevated at the end of bypass (P = 0.0002) and 4 h after surgery (P = 0.0012) compared with preoperative values, were not correlated to developmental test re
Myocardial cell damage related to arterial switch operation in neonates with transposition of the great arteries
HH Hvels-Gürich, JF Vazquez-Jimenez, A Silvestri, K Schumacher, S Kreitz, J Duchateau, BJ Messmer, G von Bernuth, M-C Seghaye
Critical Care , 2001, DOI: 10.1186/cc1009
Abstract: Sixty-three neonates (age 2-28 [8.1 ± 4.6] days), who were operated on under combined deep hypothermic (15°C) circulatory arrest and low-flow cardiopulmonary bypass (CPB), were studied. Inclusion criteria were transposition of the great arteries with or without ventricular septal defect (VSD) that was suitable for arterial switch operation (VSD-; n = 53), and if necessary additional VSD closure (VSD+; n = 10). Patients were differentiated clinically into two groups by presence or absence of MD within 24 h after surgery. MD was defined as myocardial ischaemia after coronary reperfusion and/or myocardial hypocontractility as assessed by echocardiography. MD was related to clinical outcome parameters and to perioperative release of cardiac troponin-T (cTnT) and production of interleukin-6 and interleukin-8.MD was observed in 11 patients (17.5%). Two patients died early after surgery from myocardial infarction, and two died late after surgery (6.3%). CPB and cross-clamping, but not deep hypothermic circulatory arrest times, were correlated with MD; MD was more frequent in the VSD+ than in the VSD- group because of longer support times. Coronary status and age at surgery were not related to MD. Patients with MD had more frequently impaired cardiac, respiratory and renal functions. cTnT, interleukin-6 and interleukin-8 were significantly elevated at the end of CPB, and 4 and 24 h after surgery, as compared with preoperative values in both groups. Postoperative cTnT, interleukin-6 and interleukin-8 concentrations were significantly higher in MD patients than in the others. Multivariable analysis of independent risk factors for MD revealed interleukin-6 4 h after surgery to be significant (P = 0.04; odds ratio 1.24 [95% confidence interval 1.01-1.52] per 10 pg/ml). The cutoff point for prediction of MD was set at 500 pg/ml (specificity 95.4%, sensitivity 72.7%).Cardiac operations in neonates induce the production of the proinflammatory cytokines interelukin-6 and interleuki
Neurodevelopmental outcome related to cerebral risk factors in children after neonatal arterial switch operation
HH Hvels-Gürich, MC Seghaye, M Sigler, A Bartl, F Kotlarek, J Neuser, BJ Messmer, G von Bernuth
Critical Care , 1999, DOI: 10.1186/cc330
Abstract: Protracted birth (PB), perinatal asphyxia (PA), intraventricular cerebral haemorrhage (IVH) evaluated by pre/peri/postoperative cranial ultrasound, clinical seizures (CS) and high levels of the neuron-specific enolase (NSE) prior to as well as immediately after and 4 and 24 h after CPB in 25 neonates (mean age 7 days) were defined as cerebral risk factors. Correlation analyses (Fisher's Exact Test, Pearson Coefficient) were performed to the results of formalized clinical neurological (CNS) and complete developmental score (CDS) including 7 subtests (Vienna developmental test, standard values defined normal 100 ± 10, mean ± SD) at mean age 3.7 ± 0.5 years.PB was found in 16%, PA 0%, IVH 48%, residual IVH at discharge 24%, CS prior to surgery 16%, CS > 24 h after CPB 12%. NSE, elevated prior to surgery (11.3 ± 4.5 ng/ml, mean ± SD), increased to peak values 4 h after CPB (17.3 ± 6.0) and individual peak values within 24 h after CPB (19.9-7.0). CNS was normal in 84%, 16% had strabism. CDS was normal in 88% (100 ± 8), motor score 96% (99 ± 6), visual perception 88% (100 ± 9), learning and memory 96% (102 ± 7), cognitive score 100% (101 ± 8), language 100% (99 ± 5), socioemotional score 100% (103 ± 7). Developmental scores did not differ significantly from normal children. None of the considered risk factors had significant influence on any outcome parameter (P > 0.1 in all).In our study, neurodevelopmental outcome was not found dependent on cerebral risk factors as elevated NSE indicative of neuronal cell damage, intraventricular haemorrhage, seizures or pre-/perinatal asphyxia. Rare incidence of reduced test results might have masked significant correlations.
Fabrication and characterization of a lithium-glass-based composite neutron detector
G. C. Rich,K. Kazkaz,H. P. Martinez,T. Gushue
Physics , 2014, DOI: 10.1016/j.nima.2015.05.004
Abstract: A novel composite, scintillating material intended for neutron detection and composed of small (1.5 mm) cubes of KG2-type lithium glass embedded in a matrix of scintillating plastic has been developed in the form of a 2.2 in.-diameter, 3.1 in.-tall cylindrical prototype loaded with $\left( 5.82 \pm 0.02 \right)\%$ lithium glass by mass. The response of the material when exposed to ${}^{252}$Cf fission neutrons and various $\gamma$-ray sources has been studied; using the charge-integration method for pulse shape discrimination, good separation between neutron and $\gamma$-ray events is observed and intrinsic efficiencies of $\left( 1.15 \pm 0.16 \right)\times 10^{-2}$ and $\left( 2.28 \pm 0.21 \right)\times 10^{-4}$ for ${}^{252}$Cf fission neutrons and ${}^{60}$Co $\gamma$ rays are obtained; an upper limit for the sensitivity to ${}^{137}$Cs $\gamma$ rays is determined to be $< 3.70 \times 10^{-8}$. The neutron/$\gamma$ discrimination capabilities are improved in circumstances when a neutron capture signal in the lithium glass can be detected in coincidence with a preceding elastic scattering event in the plastic scintillator; with this coincidence requirement, the intrinsic efficiency of the prototype detector for ${}^{60}$Co $\gamma$ rays is $\left( 2.42 \pm 0.61 \right)\times 10^{-6}$ while its intrinsic efficiency for unmoderated ${}^{252}$Cf fission neutrons is $\left( 4.31 \pm 0.59 \right)\times 10^{-3}$. Through use of subregion-integration ratios in addition to the coincidence requirement, the efficiency for $\gamma$ rays from ${}^{60}$Co is reduced to $\left( 7.15 \pm 4.10 \right) \times 10^{-7}$ while the ${}^{252}$Cf fission neutron efficiency becomes $\left( 2.78 \pm 0.38 \right) \times 10^{-3}$.
Polycyclic aromatic hydrocarbon in rain and street runoff in Amman, Jordan
Jiries Anwar G,Hussein Helmi H,Lintelmann Jutta,
Jiries AG
,Hussein HH,Lintelmann J

环境科学学报(英文版) , 2003,
Abstract: Concentrations of polycyclic aromatic hydrocarbons (PAHs) were determined in the rain and street runoff samples from two sites in the vicinity of Amman City during the pluvial period 1999-2000. The results showed that elevated levels of PAHs were detected in the city center (site 1) than the residential area (site 2) and that the levels were higher in street runoff than rain samples of the same sites. The highest concentration of PAHs in both street runoff and rain samples were observed in the first rainy month (November 1999) which indicated a wash out effect of PAHs originating from vehicular emission accumulated during the long dry summer season before sampling. Within the investigated cold winter seasons, fluctuations in PAHs concentration were observed. The variation was attributed to the fossil combustion for heating purposes and to intervals between rainfalls: as the longer the intervals between rains were, the higher the PAH concentration were. Removal of PAHs from the atmosphere through precipitation over the investigated period varied with time and places depending on the amount of rainfall where higher rainfall removed higher amount of PAHs from the atmosphere. The amount of PAHs washed out through precipitation was estimated to be around 14.8 mg/m2 and 21.1 mg/m2 for sites 1 and 2 respectively.
Measurements of the 48Ca(γ,n) Reaction
J. R. Tompkins,C. W. Arnold,H. J. Karwowski,G. C. Rich,L. G. Sobotka,C. R. Howell
Physics , 2011, DOI: 10.1103/PhysRevC.84.044331
Abstract: The 48Ca({\gamma},n) cross section was measured using {\gamma}-ray beams of energies between 9.5 and 15.3 MeV generated at the Triangle Universities Nuclear Laboratory (TUNL) high-intensity {\gamma}-ray source (HI{\gamma}S). Prior to this experiment, no direct measurements had been made with {\gamma}-ray beams of sufficiently low energy spread to observe structure in this energy range. The cross sections were measured at thirty-four different {\gamma}-ray energies with an enriched 48Ca target. Neutron emission is the dominant decay mechanism in the measured energy range that spans from threshold, across the previously identified M1 strength, and up the low-energy edge of the E1 giant dipole resonance (GDR). This work found B(M 1) = 6.8 \pm 0.5 {\mu}N2 for the 10.23 MeV resonance, a value greater than previously measured. Structures in the cross section commensurate with extended random-phase approximation (ERPA) calculations have also been observed whose magnitudes are in agreement with existing data.
Characterization of an INVS Model IV Neutron Counter for High Precision ($γ,n$) Cross-Section Measurements
C. W. Arnold,T. B. Clegg,H. J Karwowski,G. C. Rich,J. R. Tompkins,C. R. Howell
Physics , 2010, DOI: 10.1016/j.nima.2011.01.177
Abstract: A neutron counter designed for assay of radioactive materials has been adapted for beam experiments at TUNL. The cylindrical geometry and 60% maximum efficiency make it well suited for ($\gamma,n$) cross-section measurements near the neutron emission threshold. A high precision characterization of the counter has been made using neutrons from several sources. Using a combination of measurements and simulations, the absolute detection efficiency of the neutron counter was determined to an accuracy of $\pm$ 3% in the neutron energy range between 0.1 and 1 MeV. It is shown that this efficiency characterization is generally valid for a wide range of targets.
Cross Section Measurement of 9Be(γ,n)8Be and Implications for α+α+n -> 9Be in the r-Process
C. W. Arnold,T. B. Clegg,C. Iliadis,H. J. Karwowski,G. C. Rich,J. R. Tompkins,C. R. Howell
Physics , 2011, DOI: 10.1103/PhysRevC.85.044605
Abstract: Models of the r-process are sensitive to the production rate of 9Be because, in explosive environments rich in neutrons, alpha(alpha n,gamma)9Be is the primary mechanism for bridging the stability gaps at A=5 and A=8. The alpha(alpha n,gamma)9Be reaction represents a two-step process, consisting of alpha+alpha -> 8Be followed by 8Be(n,gamma)9Be. We report here on a new absolute cross section measurement for the 9Be(gamma,n)8Be reaction conducted using a highly-efficient, 3He-based neutron detector and nearly-monoenergetic photon beams, covering energies from E_gamma = 1.5 MeV to 5.2 MeV, produced by the High Intensity gamma-ray Source of Triangle Universities Nuclear Laboratory. In the astrophysically important threshold energy region, the present cross sections are 40% larger than those found in most previous measurements and are accurate to +/- 10% (95% confidence). The revised thermonuclear alpha(alpha n,gamma)9Be reaction rate could have implications for the r-process in explosive environments such as Type II supernovae.
Assessing Researcher Interdisciplinarity: A Case Study of the University of Hawaii NASA Astrobiology Institute
Michael G. Gowanlock,Rich Gazan
Computer Science , 2012,
Abstract: In this study, we combine bibliometric techniques with a machine learning algorithm, the sequential Information Bottleneck, to assess the interdisciplinarity of research produced by the University of Hawaii NASA Astrobiology Institute (UHNAI). In particular, we cluster abstract data to evaluate Thomson Reuters Web of Knowledge subject categories as descriptive labels for astrobiology documents, assess individual researcher interdisciplinarity, and determine where collaboration opportunities might occur. We find that the majority of the UHNAI team is engaged in interdisciplinary research, and suggest that our method could be applied to additional NASA Astrobiology Institute teams in particular, or other interdisciplinary research teams more broadly, to identify and facilitate collaboration opportunities.
Family-Based Association Analysis Confirms the Role of the Chromosome 9q21.32 Locus in the Susceptibility of Diabetic Nephropathy
Marcus G. Pezzolesi, Jackson Jeong, Adam M. Smiles, Jan Skupien, Josyf C. Mychaleckyj, Stephen S. Rich, James H. Warram, Andrzej S. Krolewski
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0060301
Abstract: A genome-wide association scan of type 1 diabetic patients from the GoKinD collections previously identified four novel diabetic nephropathy susceptibility loci that have subsequently been shown to be associated with diabetic nephropathy in unrelated patients with type 2 diabetes. To expand these findings, we examined whether single nucleotide polymorphisms (SNPs) at these susceptibility loci were associated with diabetic nephropathy in patients from the Joslin Study of Genetics of Nephropathy in Type 2 Diabetes Family Collection. Six SNPs across the four loci identified in the GoKinD collections and 7 haplotype tagging SNPs, were genotyped in 66 extended families of European ancestry. Pedigrees from this collection contained an average of 18.5 members, including 2 to 14 members with type 2 diabetes. Among diabetic family members, the 9q21.32 locus approached statistical significance with advanced diabetic nephropathy (P = 0.037 [adjusted P = 0.222]). When we expanded our definition of diabetic nephropathy to include individuals with high microalbuminuria, the strength of this association improved significantly (P = 1.42×10?3 [adjusted P = 0.009]). This same locus also trended toward statistical significance with variation in urinary albumin excretion in family members with type 2 diabetes (P = 0.032 [adjusted P = 0.192]) and in analyses expanded to include all relatives (P = 0.019 [adjusted P = 0.114]). These data increase support that SNPs identified in the GoKinD collections on chromosome 9q21.32 are true diabetic nephropathy susceptibility loci.
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