bluuebunny/crossref_metadata_2025 huggingface dataset:
Glucagon-Like Peptide-1 Inhibits Blood-Brain Glucose Transfer in Humans
Authors: Lerche Susanne , Brock Birgitte , Rungby Jørgen , Bøtker Hans E. , Møller Niels , Rodell Anders , Bibby Bo Martin , Holst Jens J. , Schmitz Ole , Gjedde Albert
Published: November 2007

OBJECTIVE— Glucagon-like peptide-1 (GLP-1) has many effects on glucose homeostasis, and GLP-1 receptors are broadly represented in many tissues including the brain. Recent research in rodents suggests a protective effect of GLP-1 on brain tissue. The mechanism is unknown. We therefore tested whether these neuroprotective effects could relate to changes of glucose transport and consumption.

RESEARCH DESIGN AND METHODS— We studied 10 healthy men in a randomized, double-blinded, placebo-controlled cross-over experiment. We used positron emission tomography to determine the acute insulin-independent effect of GLP-1 on unidirectional glucose transport into the brain during a pituitary-pancreatic normoglycemic (plasma glucose ∼4.5 mmol/l) clamp with 18-fluoro-deoxy-glucose as tracer.

RESULTS— On average, GLP-1 reduced cerebral glucose transport by 27% in total cerebral gray matter (P = 0.05) and by 25–30% in individual gray matter regions (P = 0.02–0.06). The same regions revealed a uniform trend toward similarly reduced cerebral glucose metabolism. Consequently, the intracerebral glucose concentration remained constant in all regions, with and without GLP-1.

CONCLUSIONS— We have demonstrated that a hormone involved in postprandial glucose regulation also limits glucose delivery to brain tissue and hence provides a possible regulatory mechanism for the link between plasma glucose and brain glucose. Because GLP-1 reduces glucose uptake across the intact blood-brain barrier at normal glycemia, GLP-1 may also protect the brain by limiting intracerebral glucose fluctuation when plasma glucose is increased.
Cyclical and Alternating Infusions of Glucose and Intralipid in Rats Inhibit Insulin Gene Expression and Pdx-1 Binding in Islets
Authors: Hagman Derek K. , Latour Martin G. , Chakrabarti Swarup K. , Fontes Ghislaine , Amyot Julie , Tremblay Caroline , Semache Meriem , Lausier James A. , Roskens Violet , Mirmira Raghavendra G. , Jetton Thomas L. , Poitout Vincent
Published: November 2007

OBJECTIVE—Prolonged exposure of isolated islets of Langerhans to elevated levels of fatty acids, in the presence of high glucose, impairs insulin gene expression via a transcriptional mechanism involving nuclear exclusion of pancreas-duodenum homeobox-1 (Pdx-1) and loss of MafA expression. Whether such a phenomenon also occurs in vivo is unknown. Our objective was therefore to ascertain whether chronic nutrient oversupply inhibits insulin gene expression in vivo.

RESEARCH DESIGN AND METHODS—Wistar rats received alternating 4-h infusions of glucose and Intralipid for a total of 72 h. Control groups received alternating infusions of glucose and saline, saline and Intralipid, or saline only. Insulin and C-peptide secretion were measured under hyperglycemic clamps. Insulin secretion and gene expression were assessed in isolated islets, and β-cell mass was quantified by morphometric analysis.

RESULTS—Neither C-peptide secretion nor insulin sensitivity was different among infusion regimens. Insulin content and insulin mRNA levels were lower in islets isolated from rats infused with glucose plus Intralipid. This was associated with reduced Pdx-1 binding to the endogenous insulin promoter, and an increased proportion of Pdx-1 localized in the cytoplasm versus the nucleus. In contrast, MafA mRNA and protein levels and β-cell mass and proliferation were unchanged.

CONCLUSIONS—Cyclical and alternating infusions of glucose and Intralipid in normal rats inhibit insulin gene expression without affecting insulin secretion or β-cell mass. We conclude that fatty acid inhibition of insulin gene expression, in the presence of high glucose, is an early functional defect that may contribute to β-cell failure in type 2 diabetes.
Delineating the Average Rate of Change in Longitudinal Models
Authors: Kelley Ken , Maxwell Scott E.
Published: November 2007

The average rate of change is a concept that has been misunderstood in the literature. This article attempts to clarify the concept and show unequivocally the mathematical definition and meaning of the average rate of change in longitudinal models. The slope from the straight-line change model has at times been interpreted as if it were always the average rate of change. It is shown, however, that this is generally not the case and holds true in only a limited number of situations. General equations are presented for two measures of discrepancy when the slope from the straight-line change model is used to estimate the average rate of change. The importance of fitting an appropriate individual change model is discussed, as are the benefits provided by models nonlinear in their parameters for longitudinal data. An empirical data set is used to illustrate the analytic developments.
Computer-aided diagnosis in two-phase 201Tl-SPECT of thoracic lesions
Authors: Yu Y.-H. , Chang R.-F. , Shen W.-C. , Lin D.-K. , Sun S.-S. , Tu C.-Y. , Chiu K.-L. , Hsu W.-H.
Published: November 2007

Aim: The retention index, a traditionally quantitative analysis of two-phase 201Tl single photon emission computed tomography (SPECT) of the chest, is manually calculated by experienced physicians from comparable 2-D ROI. However, a 3-D ROI would provide more information than a 2-D ROI extracted from a single frame of SPECT. We propose a new diagnostic system, computer-aided diagnosis (CAD), to automatically detect suspicious lesions as 3-D objects on chest 201Tl-SPECT, and assist the physician in interpreting these images. Patients, methods: Seventy patients with thoracic lesions and confirmed diagnoses were enrolled to test this automatic CAD system. The reliability of the CAD system in detecting lesions as 3-D objects was compared to the 2-D ROI of 201Tl-SPECT found by the manually visualized method. Furthermore, we also proposed a novel index, the retention index using the heart (RIH), to differentiate high retention (slow clearance, increasing target to heart ratio) as a criterion for a malignant lesion, from low retention (faster clearance, small or no increase of the target to heart ratio) for benign lesions. Results: The CAD system can achieve a detection rate of 100% in automatically searching for thoracic lesions in 201Tl-SPECT. In diagnostic performance, the CAD system with the RIH of comparable 3-D objects has an area under the ROC curve of 0.86, higher than the 0.78 of the traditional RI method (p = 0.198). Conclusion: The CAD system of two-phase 201Tl-SPECT is a promising tool for detecting and diagnosing thoracic lesions with a diagnostic accuracy of 0.81.
Determinants of final infarct size and incidence of aborted infarction in patients treated with primary coronary intervention and adjunctive abciximab therapy
Authors: Parodi G. , Sotgia B. , Antoniucci D. , Pupi A. , Sciagrà R.
Published: November 2007

Aims: Assess the determinants of final infarct size in patients successfully treated with primary percutaneous coronary intervention (PCI) and abciximab therapy and check whether infarct abortion may occur. Patients, methods: In 208 patients we examined the parameters that predict final infarct size and the incidence of aborted infarction, defined by completely normal perfusion and regional wall motion plus > 50% left ventricular ejection fraction (LVEF) in gated single-photon emission computed tomography (SPECT) acquired at one month. Results: In linear regression analysis, sex (p < 0.0001), high cholesterol (p < 0.05), Killip class (p < 0.0001), symptom-to-reperfusion time (p < 0.001), admission ST segment elevation (p < 0.0001), infarct related artery (p < 0.05), and pre-procedural TIMI flow (p < 0.002) were significant univariate predictors of final infarct size. In multiple linear regression analysis, symptom-to-reperfusion time (p < 0.001), Killip class (p < 0.0001), ST segment elevation (p < 0.003), and sex (p < 0.03) remained significant predictors, model R2 = 0.53. Aborted infarction was registered in 32 patients, more frequently female (59% versus 21%, p < 0.00001), older (p < 0.02), with larger prevalence of TIMI grade 3 (p < 0.05) and lower ST segment elevation at admission (p < 0.05). Conclusions: Sex, reperfusion delay, and initial infarct severity as indicated by Killip class and/or ST segment elevation appear the determinants of final infarct size in patients treated with primary PCI. The presence of aborted infarction seems related to the same factors and to preserved TIMI 3 flow.
An Exact Test for Meta-analysis with Binary Endpoints
Authors: Gromann C. , Kuss O.
Published: November 2007

Objectives
: We reintroduce an exact Mantel-Haenszel (MH) procedure for meta-analysis with binary endpoints which is expected to workespeciallywell i sparse data, e.g., in meta-analyses of safety or adverse events.

Methods
: The performance of the exact MH procedure in terms of empirical size and power is compared to the asymptotic MH and to the two standard procedures (fixed effects and random effects model) in a simulation study. We illustrate the methods with a metaanalysis of postoperative stroke occurrence after offpump or on-pump surgery in coronary artery bypass grafting.

Results
: We find that in almost all situations the asymptotic MH procedure outperforms its competitors; especially the standard methods yield poor results in terms of power and size.

Conclusions
: There is no need to use the reintroduced exact MH procedure; the asymptotic MH procedure will be sufficient in most practical situations. The standard methods (fixed effects and random effects model) should not be used in the sparse data situation.
Detection of Phase Singularities in Triangular Meshes
Authors: Wieser L. , Stühlinger M. C. , Hintringer F. , Tilg B. , Fischer G. , Rantner L. J.
Published: November 2007

Objectives
: Phase singularities have become a key marker in animal and computer models of atrial and ventricular fibrillation. However, existing algorithms for the automatic detection of phase singularities are limited to regular, quadratic mesh grids. We present an algorithm to automatically and exactly detect phase singularities in triangular meshes.

Methods
: For each node an oriented path inscribing the node with one unit of spatial discretization is identified. At each time step the phase information is calculated for all nodes. The so-called topological charge is also computed for each node. A non-zero (± 2π) charge is obtained for all nodes with a path enclosing a phase singularity. Thus all charged nodes belonging to the same phase singularity have to be clustered.

Results
: With the use of the developed algorithm, phase singularities can be detected in triangular meshes with an accuracy of below 0.2 mm – independent of the type of membrane kinetics used.

Conclusions
: With the possibility to detect phase singularities automatically and exactly, important quantitative data on cardiac fibrillation can be gained.
Zur Berücksichtigung des Bereichs kleiner Dehnungen in geotechnischen Berechnungen
Authors: Benz Thomas , Schwab Radu , Vermeer Pieter
Published: November 2007

Das nichtlineare Verhalten von Böden im Bereich kleiner Dehnungen wird in geotechnischen Berechnungen häufig vernachlässigt. Dies kann u.a. dazu führen, dass Fundamentsetzungen oder Wandverschiebungen von Verbauwänden zu groß oder dass Setzungsmulden in Folge von Tunnelvortrieben oder dem Aushub von Baugruben zu flach und ausgedehnt berechnet werden. Aus Vergleichen zwischen Messungen und Berechnungen kann weiterhin geschlossen werden, dass auch das Last‐Verformungsverhalten von Pfählen und Zugankern im Gebrauchszustand zu weich abgebildet wird, wenn das nichtlineare Verhalten von Böden im Bereich kleiner Dehnungen in Berechnungen nicht berücksichtigt wird. Dieser Beitrag diskutiert und quantifiziert die Steifigkeit von Böden unter kleinen Dehnungen und bietet so in Kombination mit dem vorgestellten, kommerziell verfügbaren numerischen Berechnungsansatz die Möglichkeit, den Bereich kleiner Dehnungen auch bei der Bearbeitung von Routineaufgaben zu berücksichtigen.
Verankerung von Spanngliedern beim Teilrückbau vorgespannter Bauwerke – eine Innovation aus UHFB
Authors: Tue Nguyen Viet , Küchler Michael , Ma Jianxin , Zink Martin , Nehrkorn Mathias
Published: November 2007

Für den Teilrückbau von vorgespannten Bauwerken ist die nachträgliche Herstellung einer sicheren Verankerung für die im Verbund liegenden Spannglieder eine wichtige Voraussetzung. In diesem Beitrag wird über eine vom Institut für Massivbau und Baustofftechnologie der Universität Leipzig entwickelte temporäre Spanngliedverankerung aus UHFB berichtet. Mit Hilfe dieses innovativen Verankerungskonzeptes können Spannglieder an beliebiger Stelle im Bauwerk, auf kürzesten Eintragungslängen, kostengünstig, einfach und sicher verankert werden.
Tragwerkssimulation von Verbundkonstruktionen aus Stahlbeton – Teil 2: Ableitungen spezifischer Ansätze und Empfehlungen für die Konstruktion
Authors: Lindig Volker
Published: November 2007

Bestimmte Konstruktionen und außergewöhnliche Beanspruchungen machen es mitunter auch bei der praktischen Tragwerksplanung erforderlich, realitätsnahe Simulationen durchzuführen, um z. B. die Entscheidungsfindung rechnerisch abzusichern sowie Detaillösungen zu beurteilen. Versuche sind auf einfache Modelltragwerke beschränkt. Eine Bewertung realer Tragwerke kann nur auf der Basis numerischer Simulationsverfahren erfolgen. Voraussetzung für solche dreidimensionalen Tragwerksanalysen unter dem Aspekt der Gebrauchs‐ und Grenztragfähigkeit sind geeignete Modelle zur Berücksichtigung der vielfältigen physikalisch nichtlinearen Einflüsse. Universelle FE‐Programme bieten hierfür die grundsätzliche Möglichkeit, eigene Materialmodelle in Abhängigkeit von der Zielstellung einzusetzen. Bei Verbundtragwerken ergibt sich zusätzlich das Problem der nachgiebigen Fuge, deren Einfluss auf das Gesamttragverhalten bedeutsam ist. Der Beitrag gliedert sich in 2 Teile: Teil 1 zeigte einen vorteilhaften Weg der Modellbildung auf. Im hier vorliegenden Teil 2 werden spezifische Ansätze für die dreidimensionale Modellierung der Verbundfuge abgeleitet. Zudem folgt für eine generierte Verbundrahmenkonstruktion die Beschreibung von Detailuntersuchungen im Eckbereich. Es werden Empfehlungen für die Konstruktion gegeben.
Zum Kontaktverhalten zwischen suspensionsgestützten Ortbetonwänden und dem anstehenden Boden
Authors: Arwanitaki Anna , König Diethard , Triantafyllidis Theodor
Published: November 2007

Eingangsparameter für analytische und numerische Berechnungen eines Baugrubenverbaus ist der Wandreibungswinkel. Dieser beschreibt die Fähigkeit, wieviel Schubspannungen aus dem Boden an der Grenzfläche Boden–Verbauwand von der Verbauwand bei einer vorgegebenen Normalspannung aufgenommen werden können. Die national gültigen Normen und Empfehlungen geben für Berechnungen im GZ1 einen Wandreibungswinkel von |δ| ≤ ϕ/2 vor. Für den Nachweis der Gebrauchstauglichkeit GZ2 hat sich die Methode der Finiten Elemente etabliert. Mit zunehmender Verfeinerung der Berechnungen stellt sich somit die Frage, ob der Ansatz von |δ| ≤ ϕ/2 noch zutreffend ist.

Bei der Herstellung von Schlitzwänden sowie von unverrohrten Bohrpfahlwänden erfolgt der Bodenaushub im Schutze einer Stützflüssigkeit aus Wasser und Bentonit. Nach Erreichen der Schlitzendtiefe wird im Kontraktorbetonverfahren die Stützsuspension von unten nach oben verdrängt. Dabei können Reste der Suspension oder des entstehenden Filterkuchens in der Kontaktfläche Boden–Verbauwand verbleiben und den Wandreibungswinkel beeinflussen.

In‐situ‐Proben des Filterkuchens einer Schlitzwandbaugrube zeigten, dass die Filterkuchenfestsubstanz ein Gemisch aus Bentonit und dem anstehenden Boden ist. Durch die Aushubarbeiten vermischt sich der anstehende Boden mit der Suspension, wobei die feinen Kornfraktionen durch die Fließgrenze der Suspension in Schwebe gehalten werden. Der durch den Filtrationsprozess an der Erdwandung entstehende Filterkuchen kann daher nicht mehr als Schmierschicht aus Bentonit bezeichnet werden, sondern besitzt eine beachtliche Scherfestigkeit.

Dieser Beitrag stellt Ergebnisse von Baustellen‐ und Laboruntersuchungen zur Beschaffenheit des Filterkuchens und zur Ermittlung des Kontaktverhaltens des Boden‐Schlitzwand‐Systems vor.
Erfahrungen mit dem Spannungs‐Verformungsverhalten von mit Geogittern bewehrten Stützkonstruktionen
Authors: Bussert Florian , Naciri Omar
Published: November 2007

Seit mehreren Jahrzehnten hat sich der Bau geokunststoffbewehrter Erdkörper erfolgreich bewährt. Die Errichtung der Stützkonstruktionen auf stark wechselndem oder gering tragfähigem Untergrund, bei hohen Verkehrslasten oder großen Konstruktionshöhen hat sich vielfach als äußerst ökonomische und ökologische Alternative zu klassischen Bauweisen bewiesen.

Um Erfahrungen mit einer neuen Bauweise zu sammeln, wird häufig die sogenannte Beobachtungsmethode angewandt, d.h., das Spannungs‐Verformungs‐Verhalten wird sowohl während der Erstellung als auch in der ersten Nutzungsphase des Bauwerks messtechnisch ermittelt. Aus diesen Messergebnissen wird deutlich, dass auch bei hoher Beanspruchung der Konstruktionen die Gesamtverformungen kleiner sind als erwartet. Vor allem die gemessenen Dehnungen der Geogitter sind kleiner als die berechneten Werte. Das derzeit verwendete Konzept zur Abschätzung der Dehnungen scheint damit weit entfernt vom tatsächlichen Verhalten derartiger Konstruktionen. Die Erfahrungen von ausgeführten Baumaßnahmen werden vorgestellt und die Ergebnisse diskutiert.
Neue Methode zur Ermittlung der Ankerlängen bei zweifach verankerten Stützwänden
Authors: Belabed Lazhar
Published: November 2007

Zur Ermittlung der erforderlichen Ankerlängen wird bei verankerten Stützwänden üblicherweise der Nachweis der tiefen Gleitfuge herangezogen. In diesem Beitrag wird ein modifiziertes Verfahren für zweifach verankerte Stützwände mit Berücksichtigung der Restankerkraft außerhalb des abrutschenden Bruchkörpers, das auf der kinematische Methode beruht, vorgeschlagen. Die Untersuchungen erfolgen nach dem probabilistischen Sicherheitskonzept. Das Verfahren liefert deutlich kürzere Ankerlängen als das herkömmliche Verfahren nach EAU. Die damit erzielte Sicherheit liegt in der gleichen Größenordnung wie die nach EAU.
Using birth defects registry data to evaluate infant and childhood mortality associated with birth defects: An alternative to traditional mortality assessment using underlying cause of death statistics
Authors: Copeland Glenn E. , Kirby Russell S.
Published: November 2007

BACKGROUND:

Although birth defects are a leading cause of death in infancy and early childhood, the proportion of all deaths to children with clinically diagnosed birth defects is not well documented. The study is intended to measure the proportion of all deaths to infants and children under age 10 occurring to children with birth defects and how and why this proportion differs from the proportion of deaths due to an underlying cause of congenital anomalies using standard mortality statistics.

METHODS:

A linked file of Michigan livebirths and deaths was combined with data from a comprehensive multisource birth defects registry of Michigan livebirths born during the years 1992 through 2000. The data were analyzed to determine the mortality rate for infants and children with birth defects and for children with no reported birth defect. Mortality risk ratios were calculated. The underlying causes of death for children with birth defects were also categorized and compared to cause‐ specific mortality rates for the general population.

RESULTS:

Congenital anomalies were the underlying cause of death for 17.8% of all infant deaths while infants with birth defects were 33.7% of all infant deaths in the study. Almost half of all Michigan deaths to children aged 1 to 2 were within the birth defects registry, though only 15.0% had an underlying cause of death of a congenital anomaly based upon standard mortality statistics. The mortality experience among children with birth defects was significantly higher than other children throughout the first 9 years of life, ranging from 4.6 for 5 year olds to 12.8 for children 1 to 2. Mortality risk ratios examined by cause of death for infants with birth defects were highest for other endocrine (28.1), other CNS (28.1), and heart (21.9) conditions. For children 1 through 9, the highest differential risk was seen for other perinatal conditions (39.0), other endocrine (29.7), other CNS (24.5), and heart (21.4).

CONCLUSIONS:

Childhood mortality analyses that incorporate birth defects registry data provide a more comprehensive picture of the full burden of birth defects on mortality in infant and children and can provide an effective mechanism for monitoring the survival and mortality risks of children with selected birth defects on a population basis. Birth Defects Research (Part A) 79:792–797, 2007. © 2007 Wiley‐Liss, Inc.
Epidemiology of bladder and cloacal exstrophies in New york state, 1983–1999
Authors: Caton Alissa R. , Bloom Anna , Druschel Charlotte M. , Kirby Russell S.
Published: November 2007

BACKGROUND:

Bladder exstrophy (BE) and cloacal exstrophy (CE) are rare birth defects that have been reported to occur in 1:30,000–50,000 and 1:200,000–400,000 live births. Disagreement exists as to whether they comprise two distinct disorders or are part of a spectrum. We examined epidemiologic trends and risk factors for BE and CE in a large population‐based dataset.

METHODS:

Potential cases were identified in the New York State (NYS) Congenital Malformations Registry. When nonspecific codes for CE were reported, narrative descriptions were reviewed for classification. Birth certificate data were analyzed with descriptive statistics and Poisson regression was used to calculate crude (PR) and adjusted prevalence ratios (aPR) and 95% confidence intervals (CI).

RESULTS:

In NYS from 1983 through 1999, 95 BE cases and 29 CE cases were identified for a live‐birth prevalence of 2.1 and 0.6 per 100,000 live births. BE showed a statistically significant downward linear trend by year. Factors associated with BE included summer conception (vs. winter, aPR 2.46, CI 1.19–5.10), white, non‐Hispanic maternal race/ethnicity (vs. black non‐Hispanic, aPR 3.20, CI 1.20–8.52), and male sex (female vs. male, aPR 0.53, CI 0.33–0.87). Factors associated with CE included preterm low birth weight birth (aPR 14.55, CI 5.28–40.07), multiple birth (aPR 6.68, CI 1.19–23.27), non‐New York City residence (aPR 3.27, CI 1.04–10.22), and female sex (aPR 2.57, CI 1.00–6.64). Infant mortality was greater in the CE group.

CONCLUSIONS:

The epidemiology suggests different risk factor patterns for BE and CE. Classification of BE and CE is difficult due to the nonspecific coding. Birth Defects Research (Part A) 79:781–787, 2007. © 2007 Wiley‐Liss, Inc.
Prevalence of down syndrome among children and adolescents in metropolitan Atlanta
Authors: Besser Lilah M. , Shin Mikyong , Kucik James E. , Correa Adolfo
Published: November 2007

BACKGROUND:

Down syndrome (DS) prevalence estimates beyond infancy are needed to assess health service needs among those with DS.

METHODS:

Children with DS born in metropolitan Atlanta from 1979 through 2003 were ascertained from a population‐based birth defects registry. Vital status through 2003 was obtained using case records, vital records, and the National Death Index. Prevalence was calculated by dividing the children surviving with DS by the population derived from U.S. Census estimates. Variations in DS prevalence by race, heart defects, age, birth cohort, and time period were examined using Poisson regression.

RESULTS:

In metropolitan Atlanta in 2003, there were 67 livebirths with DS (13.0 per 10,000 livebirths) and 738 0‐ to 19‐year‐olds surviving with DS (8.3 per 10,000 population). Over time, births to mothers 35 years and older and DS birth prevalence increased. Birth prevalence was higher among Whites, did not vary by sex, and was higher for infants without heart defects. DS prevalence among 0‐ to 14‐year‐olds increased over time (p < .05). Within each 5 year birth cohort, prevalence decreased with age: this decrease was greater among Blacks than among Whites and among children with heart defects than among children without heart defects.

CONCLUSIONS:

DS prevalence increased among livebirths and among young children. Further studies are warranted to determine whether health services are meeting the needs of an increasing number of children with DS. Birth Defects Research (Part A) 79:765–774, 2007. © 2007 Wiley‐Liss, Inc.
Using registry data to suggest which birth defects may be more susceptible to artifactual clusters and trends
Authors: Langlois Peter H. , Scheuerle Angela
Published: November 2007

BACKGROUND:

Some birth defects appear to be more susceptible than others to artifactual prevalence variability over time or geographically. This article uses an empirical approach to try to identify them.

METHODS:

Assumption: Variation in clinical practice and other artifactual sources of variability impact observed variation in prevalence of mild cases more than severe cases for a given birth defect. Approach: Data were examined from Texas Birth Defects Registry deliveries from 1999–2003. For each of 312 delivery hospitals, birth prevalence for mild cases was calculated for birth defect X. The 5th percentile was subtracted from the 95th percentile to measure spread in the frequency distribution of all hospitals. That was repeated for severe cases. The ratio of the mild:severe spread was calculated for 49 defects, and the defects ranked into quintiles. That was repeated using birth prevalence based on county, and using isolated cases. The percentages of severe cases were calculated and also ranked into quintiles. A sensitivity analysis and simulation were conducted.

RESULTS:

Forty‐nine birth defects were ranked from those least susceptible to differences in mild:severe prevalence variability (e.g., anencephaly, hypoplastic left heart syndrome) to most susceptible (e.g., atrial septal defect, fetal alcohol syndrome). Resulting quintile ranks based on the three measures were highly correlated, whether based on all cases or isolated cases.

CONCLUSIONS:

This empirical approach may be helpful for a number of public health applications. Birth defects and other health outcomes more susceptible to prevalence variability may be more likely to exhibit artifactual trends or clusters. Birth Defects Research (Part A) 79:798–805, 2007. © 2007 Wiley‐Liss, Inc.
Are there ethnic disparities in risk of preterm birth among infants born with congenital heart defects?
Authors: Nembhard Wendy N. , Salemi Jason L. , Hauser Kimberlea W. , Kornosky Jennifer L.
Published: November 2007

BACKGROUND:

Birth defects and preterm birth (PTB) are leading causes of infant morbidity and mortality in the United States. Infants with birth defects are more likely to be born preterm (<37 weeks), yet the roles of maternal ethnicity and fetal growth in this relationship are unclear. This study aimed to assess the risk of PTB among non‐Hispanic (NH) Black, NH‐White, and Hispanic infants with congenital heart defects (CHD), adjusting for fetal growth.

METHODS:

Florida Birth Defects Registry data were used to conduct a retrospective cohort study on 14,319 live‐born infants with CHDs born January 1, 1998 to December 31, 2002. ORs and 95% CIs were computed for each growth category (small‐for‐gestational age [SGA], appropriate‐for‐gestational‐age [AGA], and large‐for‐gestational‐age [LGA]) by ethnicity and adjusted for maternal and infant covariates using logistic regression.

RESULTS:

After adjusting for potential confounders, SGA and AGA NH‐Black infants with CHDs had increased risk of PTB compared to NH‐White infants with CHDs (OR 1.79; 95% CI: 1.40, 2.30 and OR 1.89; 95% CI: 1.68, 2.13, respectively). Hispanic SGA, AGA, and infants with CHDs had no increased risk of PTB compared to NH‐White infants.

CONCLUSIONS:

The increased risk of PTB among SGA and AGA NH‐Black infants with CHDs is not explained by the overall disparities in risk of PTB between NH‐Blacks and NH‐Whites. Additional studies are needed to determine the specific subtypes of CHD for which these relationships are present and if these findings are seen among infants with other birth defects. Birth Defects Research (Part A) 79:754–764, 2007. © 2007 Wiley‐Liss, Inc.
Improving the quality of surveillance data on congenital heart defects in the metropolitan Atlanta congenital defects program
Authors: Riehle‐Colarusso Tiffany , Strickland Matthew J. , Reller Mark D. , Mahle William T. , Botto Lorenzo D. , Siffel Csaba , Atkinson Mike , Correa Adolfo
Published: November 2007

BACKGROUND:

One of the challenges in epidemiologic studies of congenital heart defects (CHDs) has been the lack of a current, standard nomenclature and classification system. Recently such a standard nomenclature became available from the Society of Thoracic Surgeons (STS) Congenital Heart Surgery Database. This study reports the classification of cases of CHDs in a birth defects surveillance database using modified STS nomenclature.

METHODS:

Records of infants and fetuses in the Metropolitan Atlanta Congenital Defects Program delivered during 1968–2003 with CHD diagnoses were reviewed by a team of pediatric cardiologists. The cases were assigned one or more STS codes and subsequently grouped into successively broader levels of aggregation. Aggregation was based on presumed morphogenetically similar developmental mechanisms.

RESULTS:

There were 12,639 cases reviewed, of which 89% had a single, primary STS code. Structural CHDs were found in 7,749 infants, while 4,890 were considered to have structurally normal hearts. Application of clinical CHD nomenclature improved the clinical accuracy of surveillance data by eliminating normal physiologic variants and obligatory shunt lesions. Classification also aggregated specific CHDs into groups appropriate for research and surveillance.

CONCLUSIONS:

Application of a current, standard CHD nomenclature and classification system to cases in a birth defects surveillance database improves the specificity of cardiac diagnoses and allows for the development of a flexible case aggregation system for monitoring of CHD prevalence. Birth Defects Research (Part A) 79:743–753, 2007. © 2007 Wiley‐Liss, Inc.
Birth defects interstate data exchange: A battle worth fighting?
Authors: Cassell Cynthia , Mai Cara , Rickard Russel
Published: November 2007

BACKGROUND:

Regardless of where infants and children are delivered, diagnosed, or treated, an important aspect of population‐based birth defects surveillance is ensuring the inclusion of children with birth defects in the catchment area. However, little is known as to how the lack of interstate birth defects data exchange affects program surveillance, monitoring, prevention, and referral activities. The study objectives were to determine the status of interstate birth defects data exchange agreements and to quantify statewide data on resident births occurring in nonresident states.

METHODS:

In 2004, surveys were distributed to all population‐based birth defects programs in the United States to determine: 1) the types of interstate birth defects data exchange agreements that exist among birth defects programs, 2) perceived barriers in establishing exchange agreements, and 3) the extent to which out‐of‐state births affect a program's catchment area. The National Center for Health Statistics (NCHS) data for 2002 on live birth residency were used to determine the actual frequency of out‐of‐state live birth occurrence.

RESULTS:

Of the 52 states and territories that were surveyed, 65% (n = 34) responded. Approximately 21% (n = 7) of those that responded had an interstate data exchange agreement that allowed sharing of birth defects data with another state or a facility within another state. Approximately 53% (n = 18) of responding states indicated plans to develop an interstate birth defects data exchange agreement with other states, hospitals, or both. The NCHS data showed that the actual percentage of resident out‐of‐state live births ranged from 0.16 to 11.51. NCHS data also reveal that 78% of states would be able to capture >75% of their out‐of‐state births by sharing data on out‐of‐state births with the three neighboring states ranking highest in terms of such occurrences.

CONCLUSIONS:

Few states have interstate birth defects data exchange agreements, though all states have resident births occurring out of state. While suggestive, data beyond residency of live births are needed to quantify the degree to which the objectives of state‐based birth defects programs are compromised. Resources exist to guide programs in establishing interstate data exchange agreements. Efforts to establish such agreements with only a few neighboring states could be a large step toward improving birth defects surveillance on a state, regional, and national level. Birth Defects Research (Part A) 79:806–810, 2007. © 2007 Wiley‐Liss, Inc.
Zr‐TUD‐1: A Lewis Acidic, Three‐Dimensional, Mesoporous, Zirconium‐Containing Catalyst
Authors: Ramanathan Anand , Castro Villalobos M. Carmen , Kwakernaak Cees , Telalovic Selvedin , Hanefeld Ulf
Published: November 2007

A three‐dimensional, mesoporous, silicate containing zirconium, Zr‐TUD‐1, was synthesized by a direct hydrothermal treatment method with triethanolamine as a complexing and templating reagent to ensure that zirconium was incorporated as isolated atoms. The mesoporosity of Zr‐TUD‐1 was confirmed by X‐ray diffraction (XRD), N2 sorption and high‐resolution transmission electron micrograph (HR‐TEM) studies. The nature and strength of the Lewis acid sites present in Zr‐TUD‐1 were evaluated by FTIR studies of pyridine adsorption and temperature‐programmed desorption of ammonia. FTIR, X‐ray photoelectron spectroscopic (XPS) and UV/Vis spectroscopic studies showed that, at Si/Zr ratios of 25 and higher, all the zirconium was tetrahedrally incorporated into the mesoporous framework, while at low Si/Zr ratios, a small part of the zirconium was present as ZrO2 nanoparticles. Zr‐TUD‐1 is a Lewis acidic, stable and recyclable catalyst for the Meerwein–Ponndorf–Verley (MPV) reaction and for the Prins reaction.
A Gd3+‐Based Magnetic Resonance Imaging Contrast Agent Sensitive to β‐Galactosidase Activity Utilizing a Receptor‐Induced Magnetization Enhancement (RIME) Phenomenon
Authors: Hanaoka Kenjiro , Kikuchi Kazuya , Terai Takuya , Komatsu Toru , Nagano Tetsuo
Published: November 2007

Magnetic resonance imaging (MRI) permits noninvasive three‐dimensional imaging of opaque organisms. Gadolinium (Gd3+) complexes have become important imaging tools as MRI contrast agents for MRI studies, though most of them are nonspecific and report solely on anatomy. Recently, MRI contrast agents have been reported whose ability to relax water protons is triggered or greatly enhanced by recognition of a particular biomolecule. This new class of MRI contrast agents could open up the possibility of reporting on the physiological state or metabolic activity deep within living specimens. One possible strategy for this purpose is to utilize the increase in the longitudinal water proton r1 relaxivity that occurs upon slowing the molecular rotation of a small paramagnetic complex, a phenomenon which is known as receptor‐induced magnetization enhancement (RIME), by either binding to a macromolecule or polymerization of the agent itself. Here we describe the design and synthesis of a novel β‐galactosidase‐activated MRI contrast agent, the Gd3+ complex [Gd‐5], by using the RIME approach. β‐Galactosidase is commonly used as a marker gene to monitor gene expression. This newly synthesized compound exhibited a 57 % increase in the r1 relaxivity in phosphate‐buffered saline (PBS) with 4.5 % w/v human serum albumin (HSA) in the presence of β‐galactosidase. Detailed investigations revealed that RIME is the dominant factor in this increase of the observed r1 relaxivity, based on analysis of Gd3+ complexes [Gd‐5] and [Gd‐8], which is generated from [Gd‐5] by the activity of β‐galactosidase, and spectroscopic analysis of their corresponding Tb3+ complexes, [Tb‐5] and [Tb‐8].
Environmentally Friendly Chemoselective Oxidation of Primary Aliphatic Amines by Using a Biomimetic Electrocatalytic System
Authors: Largeron Martine , Chiaroni Angèle , Fleury Maurice‐Bernard
Published: November 2007

Environmentally friendly oxidation of primary aliphatic amines to imines has been successfully achieved, under metal‐free conditions, by the use of diverse electrogenerated o‐azaquinone mediators. High catalytic performance, together with high chemoselectivity, were observed with electron‐poor o‐azaquinone catalysts generated from 2‐aminoresorcinol derivatives. Similar to copper amine oxidase enzymes, these mediators exhibited lower reactivity toward α‐branched primary amines and no reactivity toward secondary amines. In the case of 3,4‐aminophenol derivatives lacking a 2‐hydroxy group, the generated o‐azaquinone species failed to catalyze the oxidation of the amine to the corresponding imine. Further mechanistic considerations allowed a rationalization of the crucial role of the 2‐hydroxy group in converting a catalytically inert species into a highly effective biomimetic catalyst.
Stable Silanetriols That Contain tert‐Alkoxy Groups: Versatile Precursors of Siloxane‐Based Nanomaterials
Authors: Suzuki Jumpei , Shimojima Atsushi , Fujimoto Yasuhiro , Kuroda Kazuyuki
Published: November 2007

Novel tert‐alkoxysilanetriols (ROSi(OH)3, R=adamantyl and 3‐ethyl‐3‐pentyl) have been prepared from the corresponding tert‐alkoxytrichlorosilanes and successfully used as molecular building blocks to produce ordered siloxane‐based nanomaterials. Controlled hydrolysis of the alkoxytrichlorosilanes led to the formation of crystalline powders of alkoxysilanetriols that were stable under ambient conditions. Solid‐state polycondensation of the alkoxysilanetriols occurred upon heating, which led to the formation of ordered silica–organic nanocomposites with laminated morphologies. On the other hand, silylation of the tert‐alkoxysilanetriols with chlorotrimethoxysilane enabled us to synthesize well‐defined oligomeric alkoxysilanes (ROSi[OSi(OMe)3]3). Hydrolysis and polycondensation of these oligomers followed by acid treatment gave microporous silica with narrow pore size distributions. Thus, tert‐alkoxy groups serve not only as protecting groups of siloxane species to regulate hydrolysis and polycondensation, but also as templates to generate micropores thereby providing unique synthetic pathways for the design of ordered silica‐based materials.
Stereoselective Isomerisation of N‐Allyl Aziridines into Geometrically Stable Z Enamines by Using Rhodium Hydride Catalysis
Authors: Tsang Derek S. , Yang Sharon , Alphonse France‐Aimée , Yudin Andrei K.
Published: November 2007

In the presence of rhodium(I) hydride catalysts, tertiary N‐allylamines are known to isomerise into E enamines. In contrast, we have recently found that N‐allylaziridines isomerise to form Z enamines. On the basis of literature data, the most likely mechanism of isomerisation would involve a rhodium hydride addition/β‐hydride elimination sequence. We show that the observed selectivity cannot be adequately explained by this pathway and is more consistent with initial CH‐activation followed by rearrangement to form a five‐membered cyclometallated rhodium intermediate. This intermediate subsequently undergoes reductive elimination to form a CH bond. The resulting geometrically stable Z enamines are useful building blocks for stereoselective synthesis.
Highly Efficient Total Synthesis of the Marine Natural Products (+)‐Avarone, (+)‐Avarol, (−)‐Neoavarone, (−)‐Neoavarol and (+)‐Aureol
Authors: Sakurai Junji , Oguchi Takamasa , Watanabe Kazuhiro , Abe Hideki , Kanno Syu‐ichi , Ishikawa Masaaki , Katoh Tadashi
Published: November 2007

Biologically important and structurally unique marine natural products avarone (1), avarol (2), neoavarone (3), neoavarol (4) and aureol (5), were efficiently synthesized in a unified manner starting from (+)‐5‐methyl‐Wieland–Miescher ketone 10. The synthesis involved the following crucial steps: i) Sequential BF3⋅Et2O‐induced rearrangement/cyclization reaction of 2 and 4 to produce 5 with complete stereoselectivity in high yield (2 → 5 and 4 → 5); ii) strategic salcomine oxidation of the phenolic compounds 6 and 8 to derive the corresponding quinones 1 and 3 (6 → 1 and 8 → 3); and iii) Birch reductive alkylation of 10 with bromide 11 to construct the requisite carbon framework 12 (10 + 11 → 12). An in vitro cytotoxicity assay of compounds 1–5 against human histiocytic lymphoma cells U937 determined the order of cytotoxic potency (3 > 1 > 5 > 2 > 4) and some novel aspects of structure‐activity relationships.
Order‐Disorder Phase Transition in Type‐I Clathrate Cs8Sn44□2.
Authors: Kaltzoglou Andreas , Hoffmann Stephan D. , Faessler Thomas F.
Published: November 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Computational Study of the Release of H2 from Ammonia Borane Dimer (BH3NH3)2 and Its Ion Pair Isomers.
Authors: Nguyen Vinh Son , Matus Myrna H. , Grant Daniel J. , Nguyen Minh Tho , Dixon David A.
Published: November 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
A Quantum Mechanically Guided View of Mg44Rh7.
Authors: Berger Robert F. , Lee Stephen , Hoffmann Roald
Published: November 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Calcium Chloride Rhenate(VII) Dihydrate.
Authors: Jarek Urszula , Holynska Malgorzata , Slepokura Katarzyna , Lis Tadeusz
Published: November 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Rhombohedral Boron Subnitride, B13N2, by X‐Ray Powder Diffraction.
Authors: Kurakevych Oleksandr O. , Solozhenko Vladimir L.
Published: November 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Crystal Structure of a Cerium(IV) Bis(phosphate) Derivative.
Authors: Salvado Miguel A. , Pertierra Pilar , Trobajo Camino , Garcia Jose R.
Published: November 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Sr14[Al4]2[Ge]3: A Zintl Phase with Isolated [Ge]4‐ and [Al4]8‐ Anions.
Authors: Wendorff Marco , Roehr Caroline
Published: November 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Hydrates of Li3VO4: Synthesis and Structural Chemistry.
Authors: Schnabel Simone , Roehr Caroline
Published: November 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
A Metal Nitride Carbodiimide with a Stuffed Skutterudite‐Type Structure: Synthesis, Crystal Structure and IR Spectra of (Ba6N5/6)2[NbN4] [CN2]6.
Authors: Reckeweg Olaf , Somer Mehmet , DiSalvo Francis J.
Published: November 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Optical Properties of Oxygen Vacancies in Germanium Oxides: Quantum Chemical Modeling of Photoexcitation and Photoluminescence.
Authors: Zyubin A. S. , Mebel A. M. , Lin S. H.
Published: November 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
31P Magic Angle Spinning NMR Spectroscopy for Probing Local Environments in Paramagnetic Europium‐Substituted Wells—Dawson Polyoxotungstates.
Authors: Huang Wenlin , Francesconi Lynn C. , Polenova Tatyana
Published: November 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Correlation Between Transport Properties and Lattice Effects in the NdCoO3‐Based Catalysts and Sensor Materials.
Authors: Tealdi Cristina , Malavasi Lorenzo , Gozzo Fabia , Ritter Clemens , Mozzati Maria Cristina , Chiodelli Gaetano , Flor Giorgio
Published: November 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Nickel‐Based Oxyphosphide Superconductor with a Layered Crystal Structure, LaNiOP.
Authors: Watanabe Takumi , Yanagi Hiroshi , Kamiya Toshio , Kamihara Yoichi , Hiramatsu Hidenori , Hirano Masahiro , Hosono Hideo
Published: November 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
The Highest D Value for a MnII Ion: Investigation of a Manganese(II) Polyoxometalate Complex by High‐Field Electron Paramagnetic Resonance.
Authors: Pichon Celine , Mialane Pierre , Riviere Eric , Blain Guillaume , Dolbecq Anne , Marrot Jerome , Secheresse Francis , Duboc Carole
Published: November 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
High‐Temperature Processing of Ba3ZnTa2O9: An in situ Study Using Synchrotron X‐Ray Powder Diffraction.
Authors: Mallinson Phillip M. , Claridge John B. , Rosseinsky Matthew J. , Ibberson Richard M. , Wright Jonathan P. , Fitch Andrew N.
Published: November 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Ordered Mesoporous Spinel LiMn2O4 by a Soft‐Chemical Process as a Cathode Material for Lithium‐Ion Batteries.
Authors: Luo Jia‐yan , Wang Yong‐gang , Xiong Huan‐ming , Xia Yong‐yao
Published: November 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Novel Method for Deposition of Gold—Prussian Blue Nanocomposite Films Induced by Electrochemically Formed Gold Nanoparticles: Characterization and Application to Electrocatalysis.
Authors: Kumar Shanmugam Senthil , Joseph James , Phani Kanala Lakshminarasimha
Published: November 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Preparation of Ammonia Borane in High Yield and Purity, Methanolysis, and Regeneration.
Authors: Ramachandran P. Veeraraghavan , Gagare Pravin D.
Published: November 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.