bluuebunny/crossref_metadata_2025 huggingface dataset:
Bioprocess monitoring and control via adaptive sensor calibration
Authors: Krause Daniel , Birle Stephan , Hussein Mohamed A. , Becker Thomas
Published: June 2011

To ensure optimal product quality of bioprocesses, it is necessary to develop intelligent control systems with integrated monitoring of key parameters. Having optimal yeast propagation in brewing technology is important to increase the efficiency of subsequent processes. Major drawbacks are: lacks in online detection of yeast attributes and temporal control schemes. One solution is to accurately detect essential process parameters combined with expert knowledge of linguistic control mechanisms. Those needs can be fulfilled by fuzzy logic or state observers including process dynamics associated with accurate multivariate calibration of sensing devices. Ultrasonic‐based devices could monitor key parameter but their inline implementation is limited due to influences of the temperature and gas bubbles. Thus, incipient stages for calibration of the device including temperature dependencies using time and frequency properties of ultrasonic waves are presented. A multivariate model using offline measurements with a maximum prediction error of 0.48 g/100 g is reported in this study. Additionally, we show preliminary results of a mechanistic model for the temperature dependency of yeast growth adapted from the literature (biomass and ethanol production, substrate consumption). The results will lead to flexible control of temperature and aeration resulting in vital yeast and enhanced transparency of propagation progress according to the demands.
Sociability of female bottlenose dolphins (Tursiops spp.) and chimpanzees (Pan troglodytes): Understanding evolutionary pathways toward social convergence
Authors: Pearson Heidi C.
Published: June 2011

On the northern tip of New Zealand's South Island, bottlenose dolphins (Tursiops truncatus) occasionally pass through Admiralty Bay in large, fast‐traveling groups of 100 or so individuals. Watching such a group race and splash through the water is reminiscent of a stampeding herd of ungulates, cetaceans' closest terrestrial ancestors. At other times, smaller social groups of bottlenose dolphins appear in the bay and provide a glimpse of the behavioral complexity that dolphins share with their distant relatives, the primates (Fig. 1). Despite being evolutionarily separated for 95 million years1 and evolving in vastly different environments, cetaceans and primates share striking similarities in behavior, socioecological problem‐solving, life‐history patterns, and cognitive capacity.2 By comparing attributes shared by primates and cetaceans, distraction from phylogenetic “noise” is minimized and our understanding of evolutionary pathways is enhanced. In particular, cetaceans provide a powerful outgroup for studying the evolution of primate social organization.
Linking genotypes, phenotypes, and fitness in wild primate populations
Authors: Bradley Brenda J. , Lawler Richard R.
Published: June 2011

In the decade since the first draft of the human genome was announced,1 genome sequencing projects have been initiated for an additional twenty‐some primate species. Within the next several years, genome sequence data will likely become available for all primate genera and for most individuals within some primate populations.2, 3 At the same time, gene mapping and association studies of humans and other organisms are rapidly advancing our understanding of the genetic bases of behavioral and morphological traits. Primatologists are especially well‐placed to take advantage of this coming flood of genetic data. Here we discuss what this new era of primate genomics means for field primatology and highlight some of the unprecedented opportunities it will afford, particularly with regard to examining the genetic basis of primate adaptation and diversity.
Flame resistant performance of nanocomposites coated with exfoliated graphite nanoplatelets/carbon nanofiber hybrid nanopapers
Authors: Zhuge Jinfeng , Gou Jihua , Ibeh Christopher
Published: June 2011

Exfoliated graphite nanoplatelets (xGnPs) were used to improve the flame resistant performance of glass fiber‐reinforced polyester composites. Along with xGnP, traditional intumescent fire retardant ammonium polyphosphate (APP) was introduced into the polymer matrix as the dominant additive to reduce the heat release rate (HRR) and total heat released (THR) of the composites. The cone calorimeter test results Indicate that the optimal weight ratios of xGnP and APP were 3% and 17% by weight, respectively. At such weight ratio, a synergistic effect between xGnP and APP was demonstrated. The flame resistant performance of the nanocomposites was further improved by applying xGnP‐dominant carbon nanofiber (CNF)/xGnP hybrid nanopaper onto the surface of the samples. Compared with the control sample, the integration of the HRR (THR) from 0 to 100 s of the sample coated with the nanopaper of CNF/xGnP = 1/3 shows more than 30% decrease in THR. Based on the results of mass loss, the nanopaper coating is also shown to enhance the structural stability of the samples under fire conditions, which affects the mechanical properties of the composites. The results show that the thermal properties, permeability of composites, and char formation play important roles in determining the fire behavior of the composites. Copyright © 2011 John Wiley & Sons, Ltd.
Does short‐term odour memory increase with expertise? An experimental study with perfumers, flavourists, trained panellists and novices
Authors: Valentin Dominique , Dacremont Catherine , Cayeux Isabelle
Published: June 2011

We have examined short‐term memory performance for odour recognition as a function of expertise. Experts (perfumers and flavourists), trained panellists, and novices studied three sets of common and uncommon (perfumery and flavour raw materials) odours with intentional encoding instructions. The three sets included three, six and 12 odours, respectively. As expected, recognition performance indicated an expertise effect: hit rates increased with expertise, whereas false alarm rates decreased. This effect, however, is mediated by the type and number of odours. For common odours, the effect of expertise is significant only for the larger odour set. For uncommon odours, the effect of expertise is significant for all three odour sets. Finally, an order effect was found on hit rate for novices and to a lesser extent for trained panellists, but not for perfumers and flavourists. Taken together these results indicate that, as expected, through training, experts develop a better olfactory short‐term memory than novices. This increase in short‐term memory performance might be sustained by a better ability to verbalize the odours. Copyright © 2011 John Wiley & Sons, Ltd.
Evaluation of instrumental methods for the untargeted analysis of chemical stimuli of orange juice flavour
Authors: Charve Joséphine , Chen Chi , Hegeman Adrian D , Reineccius Gary A
Published: June 2011

This work was conducted as the initial part of the evaluation of flavoromics as a tool in flavour research. The objective was to develop and evaluate methods for the untargeted analysis of chemical stimuli of orange juice flavour. It considered for study all (ideally) low molecular weight compounds as candidate chemical stimuli in flavour perception (unbiased) instead of focusing only on compounds already known to influence the flavour quality. Four commercial juices and their blend were analysed by headspace solid‐phase micro‐extraction gas chromatography (GC) and ultra‐high‐performance liquid chromatography (UHPLC)–time of flight mass spectrometry for volatiles and non‐volatiles, respectively. The developed methods were a compromise between the number of compounds extracted and detected, throughput and repeatability. The methods were tested for their ability to distinguish between orange juices based on mass spectral information using chemometrics. Classification of the samples was not the goal of the study but rather an indirect way to test the instrumental methods, the handling and chemometric analysis of these data. Classification models were obtained which allowed the categorization of the samples by brands with little overlapping, and the tight clustering of the replicates indicated a good repeatability of the methods, especially for GC and RP‐UHPLC. Fusion of GC‐ and RP‐UHPLC‐MS data sets gave similar classification models compared to that of using only data from volatiles or non‐volatiles but can offer the advantage of finding potential correlations between chemical compounds and increased accuracy in flavour predictions as it includes inputs from more compounds. Copyright © 2011 John Wiley & Sons, Ltd.
Does model fit matter for hedging? Evidence from FTSE 100 options
Authors: Alexander Carol , Kaeck Andreas
Published: June 2011

This study implements a variety of different calibration methods applied to the Heston model and examines their effect on the performance of standard and minimum‐variance hedging of vanilla options on the FTSE 100 index. Simple adjustments to the Black–Scholes–Merton model are used as a benchmark. Our empirical findings apply to delta, delta‐gamma, or delta‐vega hedging and they are robust to varying the option maturities and moneyness, and to different market regimes. On the methodological side, an efficient technique for simultaneous calibration to option price and implied volatility index data is introduced. © 2011 Wiley Periodicals, Inc. Jrl Fut Mark 32:609–638, 2012
Comparison of displacement field predicted by 2D and 3D finite element modelling of shallow NATM tunnels in clays
Authors: Svoboda Thomas , Masin David
Published: June 2011

The 2D load‐reduction method for simulating NATM tunnels using plane strain finite elements is evaluated in the paper by comparison with fully 3D simulations. Three real shallow tunnels in urban environment in different stiff clays were simulated. The soil behaviour was described by an advanced non‐linear soil constitutive model based on the hypoplasticity theory. Time‐dependent behaviour of shotcrete lining was considered in 3D simulations, whereas constant final stiffness was used in the plane strain analyses. The 2D analyses were thus controlled by a single parameter that accounts for 3D effects. It is shown that for an optimum value of this parameter, the displacement field predicted by the 2D method agrees well with the 3D simulations. In some cases only, a discrepancy was observed in the close vicinity of the tunnel. The controlling parameter was, however, found to be dependent on the problem simulated (for the same material) and also on the material properties (for the same tunnelling problem). Considering the material properties, the shear modulus at very small strain was found to be more influential than the shear modulus at large strain. The initial K0 stress state did not influence the controlling parameter substantially.

Vergleich der Prognose des Verschiebungsfeldes durch 2D‐ und 3D‐FE‐Modellierungen von seichten Tunneln im Ton Die mit finiten Elementen mit ebenem Spannungszustand arbeitende 2D‐Lastreduktionsmethode zur Simulierung von NÖTTunneln wird im vorliegenden Aufsatz im Vergleich zu vollen 3DSimulationen bewertet. Es wurden drei existierende oberflächennahe Stadttunnel in verschieden festen Tonböden simuliert. Das Bodenverhalten wurde durch ein komplexes, nicht‐lineares Bodenmodell auf Basis der Hypoplastizitätstheorie beschrieben. In den 3D‐Simulationen wurde das zeitabhängige Verhalten der Spritzbetonauskleidung untersucht, wohingegen in den Analysen der ebenen Spannungszustände die konstante, endgültige Festigkeit des Betons verwendet wurde. Die 2D‐Analysen wurden auf diese Weise durch einen einzelnen Parameter bestimmt, der den 3D‐Wirkungen Rechnung trägt. Die Untersuchung zeigt, dass für einen Optimalwert dieses Parameters das mittels der 2D‐Methode prognostizierte Verschiebungsfeld weitestgehend mit den 3DSimulationen übereinstimmt. Nur in einigen Fällen war in unmittelbarer Nähe zum Tunnel eine Diskrepanz zu beobachten. Es wurde jedoch festgestellt, dass der bestimmende Parameter von der Art des simulierten Problems abhängt (für dasselbe Material) und auch von den Materialeigenschaften (für dasselbe Tunnelbauproblem). Für die Materialeigenschaften wurde festgestellt, dass der Schubmodul bei sehr kleinen Spannungen eine größere Rolle spielt als bei großen Spannungen. Der anfängliche K0‐Lastzustand hatte keinen wesentlichen Einfluss auf den bestimmenden Parameter.
Bodenmechanische Eigenschaften organischer Ablagerungen der brandenburgischen Niederungs‐ und Luchgebiete
Authors: Rackwitz Frank , Schüßler Maik , Savidis Stavros A. , Ney Marcel
Published: June 2011

Organische Böden zeichnen sich gegenüber rein mineralischen Böden durch besonders starke Variabilität und Heterogenität aus. Zur sicheren und wirtschaftlichen Dimensionierung von Untergrundverbesserungen sowie anderen Gründungsmaßnahmen im Bereich organischer Böden sind umfangreiche Kenntnisse über die Eigenschaften und das bodenmechanische Verhalten dieser schwierigen Böden unabdingbar. In der Literatur sind hierzu bislang nur vereinzelt vollständige, teils sogar widersprüchliche Angaben zu finden. Im vorliegenden Beitrag werden die wesentlichen Ergebnisse von Laboruntersuchungen an ca. 650 überwiegend ungestörten Torf‐ und Muddeproben aus Baugrunduntersuchungen für den Verkehrswegebau im Land Brandenburg präsentiert. Es erfolgte sowohl eine Auswertung hinsichtlich bodenmechanischer Klassifikationskennwerte als auch zum lastund zeitabhängigen Verformungsverhalten sowie zum geschwindigkeitsabhängigen Scherverhalten. Zusätzlich wurden Daten von Druck‐ und Feldflügelsondierungen in die Auswertung einbezogen. Basierend auf diesen Ergebnissen wird auch als deutliche Erweiterung der aktuellen Normung eine Unterteilung der Torfe und Mudden aus bodenmechanischer Sicht vorgeschlagen. Im Beitrag wird zusätzlich auf zahlreiche Besonderheiten bei der Untersuchung organischer Böden eingegangen.

Soil mechanical properties of organic deposits in Brandenburg's lowland river valley regions. Organic soils are extremely heterogeneous and widely variable in contrast with most granular, silty and clayey soils. Safe and efficient design of subsoil improvement measures in such difficult organic soils therefore requires extensive knowledge of their properties and their mechanical behaviour. So far there has been a lack of complete and cohesive information about organic soil behaviour in the relevant literature. This paper details the main laboratory test results obtained from approx. 650 mostly undisturbed samples of peat and gyttja taken in the course of several infrastructure projects in the State of Brandenburg. Evaluation of the test results considered soil classification parameters, stress and time dependent deformation behaviour in addition to rate dependent shear behaviour. Data from cone penetration (CPT) and field vane (FVT) tests were also included in the interpretation of results. A significantly extended organic soil classification scheme is presented here based on these results. The text also takes a detailed look at a large number of specific problems that are encountered when conducting organic soil investigations.
Haldengeothermie – Chancen und Risiken bei der thermischen Nutzung von Haldenschwelbränden
Authors: Kürten Sylvia , Feinendegen Martin , Schwerdt Peter , Noel Yves , Klein Andreas , Gaschnitz Roland
Published: June 2011

Bergehalden gehören in Steinkohlerevieren zum bekannten Landschaftsbild. Eher unbekannt ist dagegen, dass im Inneren vieler Halden in Folge von Selbstentzündungsprozessen Schwelbrände vorhanden sind, die oftmals Temperaturen von mehreren Hundert Grad Celsius erreichen. Im Rahmen eines vom BMBF geförderten Verbundprojekts wird das geothermische Potenzial solcher Haldenschwelbrände untersucht. Auf einer Halde im westlichen Ruhrgebiet wurden zu diesem Zweck drei Erdwärmesonden installiert. Es hat sich gezeigt, dass die spezifischen Entzugsleistungen deutlich höher als bei herkömmlichen Geothermieanlagen sind. Zur Beschreibung der thermischen und physikalischen Eigenschaften des Haldenmaterials wurde eine Vielzahl von Versuchen im Feld und im Labor durchgeführt. Trotz der vorhandenen Inhomogenität des Materials weisen die Ergebnisse eine relativ geringe Streubreite auf. Das Arbeiten auf (alten) Bergehalden ist mit zahlreichen Herausforderungen verbunden. Der Aufwand wird jedoch durch den großen energetischen und ökologischen Nutzen gerechtfertigt.

Geothermal energy from mining waste – Chances and risks at the thermal exploitation of smouldering mining dump. Mining spoil heaps are common in coal‐mining areas. A little‐known fact that has not yet attracted much public attention is the phenomenon of smouldering inside heaps. The energetic utilization of smouldering waste heaps is being investigated as part of a joint research project funded by the BMBF. Three borehole heat exchangers were installed in a spoil heap in the western Ruhr. It can be shown that the flow temperatures and thus the achievable heat extraction rate are much higher than in conventional geothermal systems. In order to determine the thermal and physical properties of the mining materials, several field and laboratory tests were performed. The variation of the properties of the inhomogeneous material is much less than expected. When working on old mining waste heaps, many challenges have to be faced but the high energetic potential justifies the efforts.
Cancer predisposing mutations in BRCT domains
Authors: di Masi Alessandra , Gullotta Francesca , Cappadonna Valentina , Leboffe Loris , Ascenzi Paolo
Published: June 2011

Members of the breast cancer 1 (BRCA1) carboxy‐terminal (BRCT) superfamily are involved in the cellular response to the DNA damage sensing and repair, as well as in the cell cycle control. All proteins are characterized by one or more BRCT domain(s), which provides a flexible framework representing scaffolding element(s) in multi‐protein complexes. In particular, BRCA1, nibrin (NBN), and microcephalin (MCPH1), generally considered as molecular models for cancer‐prone syndromes, contain BRCT domains able to bind phosphorylated proteins. Mutations within the BRCT domains of BRCA1, NBN, and MCPH1 are responsible for cancer susceptibility, both at the homozygous and heterozygous status. Here, we report a critical analysis of: (i) the BRCT domain structure, (ii) the role of BRCA1, NBN, and MCPH1 in DNA damage sensing and repair as well as in cell cycle control, and (iii) the pathological effects of mutations within the BRCT domains of BRCA1, NBN, and MCPH1. © 2011 IUBMB IUBMB Life, 63(7): 503–512, 2011
miR‐200a modulate HUVECs viability and migration
Authors: Li Yi‐Xuan , Liu Da‐Quan , Zheng Chen , Zheng Shu‐Qi , Liu Min , Li Xin , Tang Hua
Published: June 2011

The posttranscriptional regulation of miRNAs is important for organism development. To investigate the role of miRNAs in angiogenesis, we performed a loss‐of‐function screening assay in human umbilical vein endothelial cells (HUVECs) and found that knockdown of 7 miRNAs (miR‐95a, miR‐126, miR‐129, miR‐137, miR‐139, miR‐200a, and miR‐335) significantly suppressed cell viability. As miR‐200a was highly expressed in HUVECs, blocking endogenous miR‐200a using 2′‐OMe antisense oligonucleotide (ASOs) resulted in a decrease of cell viability and migration. Bioinformatics analysis indicates the 3′ untranslated region (UTR) of thrombospondin‐1 (THBS1) has a putative binding site for miR‐200a. MiR‐200a can directly bind to THBS1 3′UTR and negatively regulate THBS1 expression. The identification of endothelial cells (ECs) related miRNA and its target gene may gain new insight into the mechanism of angiogenesis. © 2011 IUBMB IUBMB Life, 63(7): 553‐559, 2011
Fibronectin splice variants: Understanding their multiple roles in health and disease using engineered mouse models
Authors: White Eric S. , Muro Andrés F.
Published: June 2011

The extracellular matrix (ECM) is a highly dynamic network of proteins, glycoproteins, and proteoglycans. Numerous diseases result from mutation in genes coding for ECM proteins, but only recently it has been reported that mutations in the fibronectin (FN) gene were associated with a human disorder. FN is one of the main components of the ECM. It generates protein diversity through alternative splicing of a single pre‐mRNA, having at least 20 different isoforms in humans. The precise function of these protein isoforms has remained obscure in most cases. Only in the recent few years, it was possible to shed light on the multiple roles of the alternatively spliced FN isoforms. This substantial progress was achieved basically with the knowledge derived from engineered mouse models bearing subtle mutations in specific FN domains. These data, together with a recent report associating mutations in the FN gene to a form of glomerulopathy, clearly show that mutations in constitutive exons or misregulation of alternatively spliced domains of the FN gene may have nonlethal pathological consequences. In this review, we focus on the pathological consequences of mutations in the FN gene, by connecting the function of alternatively spliced isoforms of fibronectin to human diseases. © 2011 IUBMB IUBMB Life, 63(7): 538–546, 2011
Proteins with neomorphic moonlighting functions in disease
Authors: Jeffery Constance J.
Published: June 2011

One gene can encode multiple protein functions because of RNA splice variants, gene fusions during evolution, promiscuous enzyme activities, and moonlighting protein functions. In addition to these types of multifunctional proteins, in which both functions are considered “normal” functions of a protein, some proteins have been described in which a mutation or conformational change imparts a second function on a protein that is not a “normal” function of the protein. We propose to call these new functions “neomorphic moonlighting functions”. The most common examples of neomorphic moonlighting functions are due to conformational changes that impart novel protein–protein interactions resulting in the formation of protein aggregates in Alzheimers, Parkinsons disease, and the systemic amyloidoses. Other changes that can result in a neomorphic moonlighting function include a mutation in SMAD4 that causes the protein to bind to new promoters and thereby alter gene transcription patterns, mutations in two isocitrate dehydrogenase isoforms that impart a new catalytic activity, and mutations in dihydrolipoamide dehydrogenase that activate a hidden protease activity. These neomorphic moonlighting functions were identified because of their connection to disease. In the cases described herein, the new functions cause cancers or severe neurological impairment, although in most cases the mechanism by which the new function leads to disease is unknown. © 2011 IUBMB IUBMB Life, 63(7): 489–494, 2011
Structural heterogeneity and ligand gating in ferric methanosarcina acetivorans protoglobin mutants
Authors: Pesce Alessandra , Tilleman Lesley , Dewilde Sylvia , Ascenzi Paolo , Coletta Massimo , Ciaccio Chiara , Bruno Stefano , Moens Luc , Bolognesi Martino , Nardini Marco
Published: June 2011

Protoglobin from Methanosarcina acetivorans C2A (MaPgb), a strictly anaerobic methanogenic Archaea, displays peculiar structural and functional properties within members of the hemoglobin superfamily. In fact, MaPgb‐specific loops and a N‐terminal extension (20 amino acid residues) completely bury the heme within the protein matrix. Therefore, the access of diatomic gaseous molecules to the heme is granted by two apolar tunnels reaching the heme distal site from locations at the B/G and B/E helix interfaces. The presence of two tunnels within the protein matrix could be partly responsible for the slightly biphasic ligand binding behavior. Unusually, MaPgb oxygenation is favored with respect to carbonylation. Here, the crucial role of Tyr(B10)61 and Ile(G11)149 residues, located in the heme distal site and lining the protein matrix tunnels 1 and 2, respectively, on ligand binding to the heme‐Fe‐atom and on distal site structural organization is reported. In particular, tunnel 1 accessibility is modulated by a complex reorganization of the Trp(B9)60 and Phe(E11)93 side‐chains, triggered by mutations of the Tyr(B10)61 and Ile(G11)149 residues, and affected by the presence and type of the distal heme‐bound ligand.
Regulation of postnatal trabecular bone formation by the osteoblast endothelin A receptor
Authors: Clines Gregory A , Mohammad Khalid S , Grunda Jessica M , Clines Katrina L , Niewolna Maria , McKenna C Ryan , McKibbin Christopher R , Yanagisawa Masashi , Suva Larry J , Chirgwin John M , Guise Theresa A
Published: June 2011

Endothelin-1 (ET-1) is a potent vasoconstrictor that also stimulates cells in the osteoblast lineage by binding to the endothelin A receptor (ETAR). ET-1 ligand is widely secreted, particularly by the vasculature. However, the contributions of ETAR signaling to adult bone homeostasis have not been defined. ETAR was inactivated in osteoblasts by crossing ETAR-floxed and osteocalcin-Cre mice. Histomorphometric analyses were performed on 4-, 8-, and 12-week-old osteoblast-targeted ETAR knockout (KO) and wild-type (WT) male and female mice. Tibial trabecular bone volume was significantly lower from 12 weeks in KO versus WT mice in both males and females. Bone-formation rate, osteoblast density, and in vitro osteoblast differentiation were reduced by targeted inactivation of ETAR. A separate longitudinal analysis was performed between 8 and 64 weeks to examine the effect of aging and castration on bone metabolism in ETAR KO mice. Hypogonadism did not change the rate of bone accrual in WT or KO females. However, eugonadal KO males had a significantly larger increase in tibial and femoral bone acquisition than WT mice. Male mice castrated at 8 weeks of age showed the reverse: KO mice had reduced rates of tibial and femoral BMD acquisition compared with WT mice. In vitro, ET-1 increased osteoblast proliferation, survival, and differentiation. Dihydrotestosterone also increased osteoblast differentiation using a mechanism distinct from the actions of ET-1. These results demonstrate that endothelin signaling in osteoblasts is an important regulator of postnatal trabecular bone remodeling and a modulator of androgen effects on bone. © 2011 American Society for Bone and Mineral Research
High serum 25-hydroxyvitamin D is associated with a low incidence of stress fractures
Authors: Burgi Alina A , Gorham Edward D , Garland Cedric F , Mohr Sharif B , Garland Frank C , Zeng Kenneth , Thompson Kerry , Lappe Joan M
Published: June 2011

Low serum 25-hydroxyvitamin D [25(OH)D] concentrations are associated with hip fractures, but the dose-response relationship of serum 25(OH)D with risk of stress fractures in young women is unknown. This nested case-control study in a cohort of female Navy recruits was designed to determine whether those with low prediagnostic serum 25(OH)D concentrations had greater risk of stress fracture. Sera were drawn in 2002–2009 from 600 women who were diagnosed subsequently with stress fracture of the tibia or fibula and 600 matched controls who did not experience a stress fracture. The 25(OH)D concentration was measured using the DiaSorin radioimmunoassay method. Controls were individually matched to cases on race (white, black, or other), length of service (±30 days), and day blood was drawn (±2 days). There was approximately half the risk of stress fracture in the top compared with the bottom quintile of serum 25(OH)D concentration (odds ratio [OR] = 0.51, 95% CI 0.34–0.76, p ≤ 0.01). The range of serum 25(OH)D in the lowest quintile was 1.5 to 19.7 (mean 13.9) ng/mL, whereas in the highest it was 39.9 to 112 (mean 49.7) ng/mL. It is concluded that there was a monotonic inverse dose-response gradient between serum 25(OH)D and risk of stress fracture. There was double the risk of stress fractures of the tibia and fibula in women with serum 25(OH)D concentrations of less than 20 ng/mL compared to those with concentrations of 40 ng/mL or greater. A target for prevention of stress fractures would be a serum 25(OH)D concentration of 40 ng/mL or greater, achievable with 4000 IU/d of vitamin D3 supplementation. © 2011 American Society for Bone and Mineral Research
Subperitoneal adenomucinosis following proctocolectomy for ulcerative colitis
Authors: Ryan E. Ronan , Hosseinzadeh Keyanoosh , Bansal Mona , Schraut Wolfgang H.
Published: June 2011

Adenomucinosis is a rare condition characterized by accumulation of large volumes of mucin, typically related to mucinous neoplasms of the appendix within the peritoneal space. Extraperitoneal adenomucinosis is an uncommon variant where mucin accumulates outside the peritoneal space and usually arises following surgery for mucinous appendiceal neoplasms. This is a case of subperitoneal adenomucinosis resulting from retention of a small fragment of rectal mucosa following proctocolectomy for ulcerative colitis 16 years prior. The patient presented with a slow‐growing boggy perineal mass. Contrast‐enhanced magnetic resonance imaging (MRI) showed the mass to be localized to the pelvis, without solid enhancing components, and correctly facilitated local surgical excision without the risk of peritoneal dissemination and accurately predicted benignity. J. Magn. Reson. Imaging 2011;. © 2011 Wiley‐Liss, Inc.
Effects of respiratory cycle and body position on quantitative pulmonary perfusion by MRI
Authors: Cao Jie J. , Wang Yi , Schapiro William , McLaughlin Jeannette , Cheng Joshua , Passick Michael , Ngai Nora , Marcus Philip , Reichek Nathaniel
Published: June 2011

Purpose:

To evaluate the performance of lung perfusion imaging using two‐dimensional (2D) first pass perfusion MRI and a quantitation program based on model‐independent deconvolution algorithm.

Materials and Methods:

In eight healthy volunteers 2D first pass lung perfusion was imaged in coronal planes using a partial Fourier saturation recovery stead state free precession (SSFP) technique with a temporal resolution of 160 ms per slice acquisition. The dynamic signal in the lung was measured over time and absolute perfusion calculated based on a model‐independent deconvolution program.

Results:

In the supine position mean pulmonary perfusion was 287 ± 106 mL/min/100 mL during held expiration. It was significantly reduced to 129 ± 68 mL/min/100 mL during held inspiration. Similar differences due to respiration were observed in prone position with lung perfusion much greater during expiration than during inspiration (271 ± 101 versus 99 ± 38 mL/min/100 mL (P < 0.01)). There was a linear increase in pulmonary perfusion from anterior to posterior lung fields in supine position. The perfusion gradient reversed in the prone position with the highest perfusion in anterior lung and the lowest in posterior lung fields.

Conclusion:

Lung perfusion imaging using a 2D saturation recovery SSFP perfusion MRI coupled with a model‐independent deconvolution algorithm demonstrated physiologically consistent dynamic heterogeneity of lung perfusion distribution. J. Magn. Reson. Imaging 2011;. © 2011 Wiley‐Liss, Inc.
dGEMRIC and subsequent T1 mapping of the hip at 1.5 Tesla: Normative data on zonal and radial distribution in asymptomatic volunteers
Authors: Bittersohl Bernd , Hosalkar Harish S. , Werlen Stefan , Trattnig Siegfried , Siebenrock Klaus A. , Mamisch Tallal C.
Published: June 2011

Purpose:

To characterize the zonal distribution of three‐dimensional (3D) T1 mapping in the hip joint of asymptomatic adult volunteers.

Materials and Methods:

This study included 10 volunteers (3 males and 7 females with a mean age of 26.5 years; range, 24–31 years). MRI protocol included standard sequences for hip imaging and a dual‐flip‐angle 3D gradient‐echo (GRE) sequence with volumetric interpolated breathhold examination (VIBE) postcontrast administration. Seven radial cuts were created clockwise around the femoral neck by using multi‐planar reconstruction.

Results:

Analysis of the radial distribution revealed an increase of T1‐values toward the superior regions. T1‐values differed between the peripheral and central portions. The standard deviation (SD) ranged from 76.2 ms to 124.1 ms in the peripheral zone, and from 69.1 ms to 112.9 ms in the central zone. In both zones, SD was low in the superior regions compared with the anterior and posterior regions of the joint. Based on the high intra‐ (0.95) and interobserver (0.87) agreement, normative data from this study will prepare the foundation for further studies of dGEMRIC and T1 in the hip.

Conclusion:

We noted a radial T1 mapping pattern with higher values in the superior zone that was not statistically significant and a notable trend in zonal distribution between peripheral and central zones. These findings are critical while outlining future studies for detailed objective evaluation of zonal cartilage lesions due to varying pathologies. J. Magn. Reson. Imaging 2011;. © 2011 Wiley‐Liss, Inc.
Investigation of acupoint specificity by multivariate granger causality analysis from functional MRI data
Authors: Feng Yuanyuan , Bai Lijun , Zhang Wensheng , Xue Ting , Ren Yanshuang , Zhong Chongguang , Wang Hu , You Youbo , Liu Zhenyu , Dai Jianping , Liu Yijun , Tian Jie
Published: June 2011

Purpose:

To investigate the acupoint specificity by exploring the effective connectivity patterns of the poststimulus resting brain networks modulated by acupuncture at the PC6, with the same meridian acupoint PC7 and different meridian acupoint GB37.

Materials and Methods:

The functional MRI (fMRI) study was performed in 36 healthy right‐handed subjects receiving acupuncture at three acupoints, respectively. Due to the sustained effects of acupuncture, a novel experimental paradigm using the nonrepeated event‐related (NRER) design was adopted. Psychophysical responses (deqi sensations) were also assessed. Finally, a newly multivariate Granger causality analysis (mGCA) was used to analyze effective connectivity patterns of the resting fMRI data taken following acupuncture at three acupoints.

Results:

Following acupuncture at PC6, the red nucleus and substantia nigra emerged as central hubs, in comparison with the fusiform gyrus following acupuncture at GB37. Red nucleus was also a target following acupuncture at PC7, but with fewer inputs than those of PC6. In addition, the most important target following acupuncture at PC7 was located at the parahippocampus.

Conclusion:

Our findings demonstrated that acupuncture at different acupoints may exert heterogeneous modulatory effects on the causal interactions of brain areas during the poststimulus resting state. These preliminary findings provided a clue to elucidate the relatively function‐oriented specificity of acupuncture effects. J. Magn. Reson. Imaging 2011;. © 2011 Wiley‐Liss, Inc.
MRI assessment of iron deposition in multiple sclerosis
Authors: Ropele Stefan , de Graaf Wolter , Khalil Michael , Wattjes Mike P. , Langkammer Christian , Rocca Maria A. , Rovira Alex , Palace Jacqueline , Barkhof Frederik , Filippi Massimo , Fazekas Franz
Published: June 2011

Iron deposition in the human brain tissue occurs in the process of normal aging and in many neurodegenerative diseases. Elevated iron levels in certain brain regions are also an increasingly recognized finding in multiple sclerosis (MS). The exact mechanism(s) for this phenomenon and its implication in terms of pathophysiology and clinical significance are still largely unknown and debated. Reliable methods to exactly quantify brain iron are a first step to clarify these issues. Therefore, the aim of this review is to present currently available magnetic resonance imaging (MRI) techniques for the assessment of brain iron. These include relaxation time mapping, phase imaging, susceptibility‐weighted imaging, susceptibility mapping, magnetic field correlation imaging, and direct saturation imaging. After discussing their advantages and disadvantages, existing MRI clinical correlations with brain iron concentration in MS are summarized and future research directions are shown. J. Magn. Reson. Imaging 2011;. © 2011 Wiley‐Liss, Inc.
In vivo single scan detection of both iron‐labeled cells and breast cancer metastases in the mouse brain using balanced steady‐state free precession imaging at 1.5 T
Authors: Ribot Emeline J. , Martinez‐Santiesteban Francisco M. , Simedrea Carmen , Steeg Patricia S. , Chambers Ann F. , Rutt Brian K. , Foster Paula J.
Published: June 2011

Purpose:

To simultaneously detect iron‐labeled cancer cells and brain tumors in vivo in one scan, the balanced steady‐state free precession (b‐SSFP) imaging sequence was optimized at 1.5 T on mice developing brain metastases subsequent to the injection of micron‐sized iron oxide particle‐labeled human breast cancer cells.

Materials and Methods:

b‐SSFP sequence parameters (repetition time, flip angle, and receiver bandwidth) were varied and the signal‐to‐noise ratio, contrast between the brain and tumors, and the number of detected iron‐labeled cells were evaluated.

Results:

Optimal b‐SSFP images were acquired with a 26 msec repetition time, 35° flip angle, and bandwidth of ±21 kHz. b‐SSFP images were compared with T2‐weighted 2D fast spin echo (FSE) and 3D spoiled gradient recalled echo (SPGR) images. The mean tumor‐brain contrast‐to‐noise ratio and the ability to detect iron‐labeled cells were the highest in the b‐SSFP images.

Conclusion:

A single b‐SSFP scan can be used to visualize both iron‐labeled cells and brain metastases. J. Magn. Reson. Imaging 2011;. © 2011 Wiley‐Liss, Inc.
Unenhanced ECG‐gated fast spin‐echo MR digital subtraction angiography (MRDSA) using short echo‐spacing three‐dimensional sequence of femoral arteries: Initial experience
Authors: Morita Satoru , Kojima Shinya , Hirata Masami , Suzuki Masaru , Suzuki Kazufumi , Masukawa Ai , Ueno Eiko
Published: June 2011

Purpose:

To compare the image qualities of unenhanced electrocardiographically (ECG)‐gated fast spin‐echo magnetic resonance digital subtraction angiography (MRDSA) using a short echo‐spacing three‐dimensional (3D) sequence, known as sampling perfection with application‐optimized contrasts using different flip angle evolutions (SPACE), and the conventional half‐Fourier single‐shot turbo spin‐echo (HASTE) sequence.

Materials and Methods:

Unenhanced ECG‐gated MRDSA using SPACE and HASTE of the femoral arteries were prospectively acquired in 13 healthy volunteers at 1.5 Tesla (T) MRI. Sequential frontal maximum‐intensity‐projection images produced by subtracting each of 10 systolic images from a diastolic image were evaluated quantitatively using paired t‐test and qualitatively by two blinded radiologists using the Mann‐Whitney U‐test.

Results:

Quantitatively, relative contrast against the background, contour sharpness index, and slope of the sequential signal changes of the superficial femoral artery of MRDSA using SPACE were significantly better than those of HASTE (P = 0.005, P = 0.001, and P < 0.0001, respectively). Qualitatively, the overall subjective image quality and sequential appearance changes of MRDSA using SPACE were significantly better than those of HASTE (P < 0.0001 and P < 0.0001, respectively).

Conclusion:

Unenhanced ECG‐gated fast spin‐echo MRDSA using SPACE produces increments in signal intensity, which reflect arterial pulse wave transmission, more clearly than the conventional HASTE sequence. J. Magn. Reson. Imaging 2011;. © 2011 Wiley‐Liss, Inc.
Prostate cancer: Utility of fusion of T2‐weighted and high b‐value diffusion‐weighted images for peripheral zone tumor detection and localization
Authors: Rosenkrantz Andrew B. , Mannelli Lorenzo , Kong Xiangtian , Niver Ben E. , Berkman Douglas S. , Babb James S. , Melamed Jonathan , Taneja Samir S.
Published: June 2011

Purpose:

To retrospectively assess the utility of fusion of T2‐weighted images (T2WI) and high b‐value diffusion‐weighted images (DWI) for prostate cancer detection and localization.

Materials and Methods:

In this IRB‐approved HIPAA‐compliant study, 42 patients with prostate cancer underwent MRI including multiplanar T2WI and axial DWI before prostatectomy. Two independent radiologists first assessed multiplanar T2WI and axial DWIb‐1000 images and recorded whether tumor was present in each sextant. Axial T2WI was then fused with axial DWIb‐1000 images, and the radiologists re‐evaluated each sextant for tumor. Accuracy was compared using generalized estimating equations based on a binary logistic regression model.

Results:

The accuracy, sensitivity, specificity, PPV, and NPV for tumor detection on a sextant‐basis using separate and fused image sets was 65.1%, 50.8%, 78.0%, 67.8%, and 63.6% and 71.0%, 60.8%, 80.3%, 73.7%, and 69.3%, respectively, for reader 1, and 54.0%, 42.5%, 64.4%, 52.0%, and 55.2%, and 61.1%, 56.7%, 65.2%, 59.6%, and 62.3%, respectively, for reader 2. The improvements in accuracy, sensitivity, and NPV using fused images were statistically significant for both readers, as was the improvement in PPV for reader 2 (P ranging from <0.0001 to 0.041). With either separate or fused images, there was greater sensitivity for tumors of higher grade or larger size (P ranging from <0.001 to 0.099).

Conclusion:

Fusion of T2WI and high b‐value DWI resulted in significant improvements in sensitivity and accuracy for tumor detection on a sextant‐basis, with similar specificity. J. Magn. Reson. Imaging 2011;. © 2011 Wiley‐Liss, Inc.
Measuring lung water: Ex vivo validation of multi‐image gradient echo MRI
Authors: Holverda Sebastiaan , Theilmann Rebecca J. , Sá Rui C. , Arai Tatsuya J. , Hall Evan T. , Dubowitz David J. , Prisk G. Kim , Hopkins Susan R.
Published: June 2011

Purpose:

To validate a fast gradient echo sequence for rapid (9 s) quantitative imaging of lung water.

Materials and Methods:

Eleven excised pig lungs were imaged with a fast GRE sequence in triplicate, in the sagittal plane at 2 levels of inflation pressure (5 and 15 cm H2O), an intervention that alters T2*, but not total lung water. Images were acquired alternating between two closely‐spaced echoes and data were fit (voxel‐by‐voxel) to a single exponential to determine T2* and water content, and compared with gravimetric measurements of total water.

Results:

T2* averaged 1.08 ± 0.02 ms at 5 cm H2O and 1.02 ± 0.02 ms at 15 cm H2O (P < 0.05). The measure was reliable (R2 = 0.99), with an average mean error of 1.8%. There was a significant linear relationship between the two measures of water content: The regression equations for the relationship were y = 0.92x + 19 (R2 = 0.94), and y = 1.04x + 4 (R2 = 0.96), for 5 and 15 cm H2O inflation pressure respectively. Y‐intercepts were not statistically different from zero (P = 0.86).

Conclusion:

The multi‐echo GRE sequence is a reliable and valid technique to assess water content in the lung. This technique enables rapid assessment of lung water, which is advantageous for in vivo studies. J. Magn. Reson. Imaging 2011;. © 2011 Wiley‐Liss, Inc.
Development of a UHPLC method for the assessment of the metabolic profile of cinitapride
Authors: Marquez Helena , Albertí Joan , Salvà Miquel , Saurina Javier , Sentellas Sonia
Published: June 2011

An ultra high‐performance liquid chromatographic method was developed to study the cinitapride metabolism. Metabolites were generated from the incubation of cinitapride with human liver microsomes. Cinitapride and its metabolites were separated by reversed‐phase mode using a formate aqueous solution (pH 6.5) and acetonitrile as the components of the mobile phase. Chromatographic conditions, including the establishment of an elution gradient, were optimized for obtaining the maximum number of resolved components in the minimum analysis time. Experimental design and multicriteria decision‐making strategies were utilized to facilitate the optimization of chromatographic conditions. Figures of merit were evaluated with cinitapride standards and incubated samples. Limits of detection are about 0.03 μmol/L, and repeatabilities are better than 0.06% for retention times and better than 3.5% for concentrations. The method was applied to characterize the in vitro cinitapride metabolism with human liver microsomes.
Preparation of zwitterionic polymeric monolithic columns for hydrophilic interaction capillary liquid chromatography
Authors: Chen Xin , Tolley H. Dennis , Lee Milton L.
Published: June 2011

Porous zwitterionic monolithic columns based on photo‐initiated copolymerization of N,N‐dimethyl‐N‐methacryloxyethyl‐N‐(3‐sulfopropyl)ammonium betaine and poly(ethylene glycol) diacrylate in a binary porogen system comprising isopropanol and decanol were prepared in 75‐μm‐id fused silica capillaries. The resulting monolith was evaluated by hydrophilic interaction chromatography. Inverse size‐exclusion chromatography was used to characterize the pore structure of the resulting monolith. A typical hydrophilic interaction chromatography mechanism was observed when the organic content in the mobile phase was higher than 60%. Good separations of amides, phenols, and benzoic acids were achieved. An efficiency of 75 000 plates/m was obtained. The effects of mobile phase pH, salt concentration, and organic modifier content on retention were investigated. For polar‐charged analytes, both hydrophilic interactions and electrostatic interactions contributed to the selectivity.
Application of pneumatic nebulization single‐drop microextraction for the determination of organophosphorous pesticides by gas chromatography–mass spectrometry
Authors: Wang Yeqiang , Wang Ziming , Zhang Huihui , Shi Yuhua , Ren Ruibing , Zhang Hanqi , Yu Yong
Published: June 2011

Organophosphorous pesticides (OPPs) including dichlorvos, diazinon, malathion, phenamiphos and chlorpyrifos, in water samples were extracted by pneumatic nebulization single‐drop microextraction (PN‐SDME) and then determined by gas chromatography–mass spectrometry (GC‐MS). Experimental parameters affecting the performances of PN‐SDME, such as flow rate of carrier gas, extraction time and microdrop volume, were examined and optimized. The limits of detection for the analytes were in the range of 0.0014–0.0019 μg/mL. The linear range was 0.0050–0.50 μg/mL, except dichlorvos (0.0070–0.50 μg/mL). Water samples were analyzed and the recoveries of the analytes in the spiked water samples were from 75.2 to 105.3%. The relative standard deviations were lower than 12.7%.
Liquid chromatography–electrospray ionization tandem mass spectrometry for the quantification of styraxlignolide A in rat plasma
Authors: Ji Hye Y. , Oh Sei‐Ryang , Lee Hyeong‐Kyu , Na Dong H. , Lee Hye S.
Published: June 2011

Styraxlignolide A is a pharmacologically active ingredient isolated from Styrax japonica Sieb. et Zucc. A rapid, selective, and sensitive liquid chromatographic method with electrospray ionization tandem mass spectrometry was developed for use in the quantification of styraxlignolide A in rat plasma. Styraxlignolide A was extracted from rat plasma using ethyl acetate at neutral pH. The analytes were separated on an Atlantis dC18 column using a mixture of methanol and ammonium formate (10 mM, pH 3.0) (70:30, v/v) and detected by tandem mass spectrometry in multiple reaction monitoring mode. The standard curve was linear (r2=0.9978) over the concentration range of 100−10000 ng/mL. The lower limit of quantification was 100 ng/mL using 50 μL of plasma sample. The coefficient of variation and relative error for intra‐ and inter‐assays at four QC levels were 1.6–8.3% and from −12.0 to −1.7%, respectively. The present method was applied successfully to the pharmacokinetic study of styraxlignolide A after intravenous administration of styraxlignolide A at a dose of 10 mg/kg in male Sprague–Dawley rats.