bluuebunny/crossref_metadata_2025 huggingface dataset:
Real-Time Polymerase Chain Reaction for the Rapid Detection of Group B Streptococcal Colonization in Neonates
Authors: Natarajan Girija , Johnson Yvette R. , Zhang Fan , Chen Kang Mei , Worsham Maria J.
Published: July 2006

BACKGROUND. Group B streptococcal (GBS) infection remains a leading cause of neonatal sepsis. Currently, the management guidelines of neonates born to women with unknown GBS status at delivery are unclear. In this cohort, who undergo at least a 48-hour observation, a rapid method of detection of GBS colonization would allow targeted evaluation and treatment, as well as prevent delayed discharge.

OBJECTIVE. The goal of this research was to evaluate the validity of rapid fluorescent real-time polymerase chain reaction in comparison with standard culture to detect GBS colonization in infants born to women whose GBS status is unknown at delivery.

DESIGN/METHODS. Neonates at >32 weeks' gestation born to women whose GBS status was unknown at delivery were included. Samples were obtained from the ear, nose, rectum, and gastric aspirate for immediate culture and real-time polymerase chain reaction after DNA extraction using the LightCycler. Melting point curves were generated, and confirmatory agar gel electrophoresis was performed.

RESULTS. The study population (n = 94) had a mean ± SD gestational age of 38 ± 2 weeks and birth weight of 3002 ± 548 g. The rates of GBS colonization by culture were 17% and 51% by real-time polymerase chain reaction. The 4 surface sites had comparable rates of GBS. The overall sensitivities, specificities, and positive and negative predictive values of real-time polymerase chain reaction were: 90%, 80.3%, 28%, and 98.9%.

CONCLUSIONS. Real-time polymerase chain reaction resulted in a threefold higher rate of detection of GBS colonization and had an excellent negative predictive value in a cohort of neonates with unknown maternal GBS status at delivery. Thus, real-time polymerase chain reaction would be a useful clinical tool in the management of those infants potentially at risk for invasive GBS infection and would allow earlier discharge for those found to be not at risk.
Regional Brain Development in Serial Magnetic Resonance Imaging of Low-Risk Preterm Infants
Authors: Mewes Andrea U.J. , Hüppi Petra S. , Als Heidelise , Rybicki Frank J. , Inder Terrie E. , McAnulty Gloria B. , Mulkern Robert V. , Robertson Richard L. , Rivkin Michael J. , Warfield Simon K.
Published: July 2006

OBJECTIVE. MRI studies have shown that preterm infants with brain injury have altered brain tissue volumes. Investigation of preterm infants without brain injury offers the opportunity to define the influence of early birth on brain development and provide normative data to assess effects of adverse conditions on the preterm brain. In this study, we investigated serial MRI of low-risk preterm infants with the aim to identify regions of altered brain development.

METHODS. Twenty-three preterm infants appropriate for gestational age without magnetic resonance–visible brain injury underwent MRI twice at 32 and at 42 weeks’ postmenstrual age. Fifteen term infants were scanned 2 weeks after birth. Brain tissue classification and parcellation were conducted to allow comparison of regional brain tissue volumes. Longitudinal brain growth was assessed from preterm infants’ serial scans.

RESULTS. At 42 weeks’ postmenstrual age, gray matter volumes were not different between preterm and term infants. Myelinated white matter was decreased, as were unmyelinated white matter volumes in the region including the central gyri. The gray matter proportion of the brain parenchyma constituted 30% and 37% at 32 and 42 weeks’ postmenstrual age, respectively.

CONCLUSIONS. This MRI study of preterm infants appropriate for gestational age and without brain injury establishes the influence of early birth on brain development. No decreased cortical gray matter volumes were found, which is in contrast to findings in preterm infants with brain injury. Moderately decreased white matter volumes suggest an adverse influence of early birth on white matter development. We identified a sharp increase in cortical gray matter volume in preterm infants’ serial data, which may correspond to a critical period for cortical development.
Sensitivity and Specificity of Pediatric Lipid Determinations for Adult Lipid Status: Findings From the Princeton Lipid Research Clinics Prevalence Program Follow-up Study
Authors: Friedman Lisa Aronson , Morrison John A. , Daniels Stephen R. , McCarthy William F. , Sprecher Dennis L.
Published: July 2006

OBJECTIVE. The goal was to determine the diagnostic utility of the National Cholesterol Education Program pediatric guidelines.

METHODS. With the use of pediatric lipid data from the Cincinnati Clinic of the Lipid Research Clinics Prevalence Study and lipid and cardiovascular disease data collected for the same subjects as adults in the Princeton Follow-up Study, the sensitivity and specificity of the National Cholesterol Education Program pediatric guidelines were calculated overall and according to age. Furthermore, whether use of parental cardiovascular disease history during childhood influenced the sensitivity and specificity was assessed.

RESULTS. Overall sensitivities were 43% to 46% and specificities were 82% to 86% for total and low-density lipoprotein cholesterol levels. There was considerable variation in sensitivities according to age, with the lowest sensitivities at ages 14 to 16 years and the highest sensitivities at ages 5 to 10 years and 17 to 19 years. Results were similar whether or not the population was restricted to children with a positive parental history of cardiovascular disease.

CONCLUSIONS. Results of our analyses suggest that the sensitivity and specificity for evaluating total cholesterol or low-density lipoprotein cholesterol levels that are elevated in adulthood are not improved by selecting children with a positive parental history. These data also show the strong role that age (particularly the pubertal years between 10 and 15 years of age) plays in lipid measurements for children and adolescents. Continued prospective and longitudinal studies designed with age as well as other risk parameters are needed to determine the best guidelines for clinical screening in the future.
Synthesis of a Hydrothermally Stable, Periodic Mesoporous Material Containing Magnetite Nanoparticles, and the Preparation of Oriented Films
Authors: Alvaro M. , Aprile C. , Garcia H. , Gómez‐García C. J.
Published: July 2006

Magnetite nanoparticles modified covalently with triethoxysilane having a quaternary dicetyl ammonium ion are used together with tetraethylorthosilicate as building blocks to prepare a mesoporous material. Cetyltrimethylammonium bromide is used as a structure‐directing agent under conditions typically used for mesoporous MCM‐41 silicas. The resulting mesoporous material (MAG‐MCM‐41), containing up to 15 wt % of magnetite is characterized by transmission electron microscopy (TEM), isothermal gas adsorption, and X‐ray diffraction. In contrast to siliceous MCM‐41, mesoporous MAG‐MCM‐41 exhibits a remarkable hydrothermal stability. The magnetic properties of MAG‐MCM‐41 are characterized by DC and AC magnetic susceptibility, and by isothermal hysteresis cycles, confirming the long‐range magnetic ordering above 400 K. As evidenced by atomic force microscopy and TEM, the ability to respond to magnetic fields is used to orient films of MAG‐MCM‐41 with the channels perpendicular to a support.
A dual‐scale model for describing drier and porous medium interactions
Authors: Perré Patrick , Turner Ian W.
Published: July 2006

A dual‐scale modeling approach is proposed to describe the coupling of the drier (large‐scale) and the porous medium (macroscale) throughout drying. This model is used to investigate the vacuum drying of a softwood board placed in an experimental vacuum chamber that is heated by two infrared (IR) emitters. The large‐scale model provides important information for the drying engineer to assess and tune the performance of the drier. This model allows simulation of the chamber wall and IR emitter temperature evolution, together with changes in the chamber vapor, air, and water mass balances. The comprehensive two‐dimensional drying model known as TransPore is used to determine the heat and mass transfer occurring at the macroscale of the board. Finally, four case studies are presented to elucidate the intricate coupling that exists between the chamber technical specifications and the drying behavior of the porous medium. A highlight of the dual‐scale model is its ability to predict the condensation on the walls of a poorly insulated vacuum chamber for the case of a weak pump. © 2006 American Institute of Chemical Engineers AIChE J, 2006
Association study between genetic variants at the PIP5K2A gene locus and schizophrenia and bipolar affective disorder
Authors: Jamra Rami Abou , Klein Katrin , Villela Angela Wolf , Becker Tim , Schulze Thomas G. , Schmael Christine , Deschner Monika , Klopp Norman , Illig Thomas , Propping Peter , Cichon Sven , Rietschel Marcella , Nöthen Markus M. , Schumacher Johannes
Published: July 2006

Results from molecular and pharmacological studies point to involvement of the gene coding for the phosphatidylinositol‐4‐phosphate 5‐kinase type II‐alpha (PIP5K2A) in the development of schizophrenia and bipolar affective disorder (BPAD). The PIP5K2A gene locus, which is located on chromosomal region 10p12, has been implicated in the development of both disorders by independent linkage and association studies. On a cellular level, PIP5K2A is an enzyme component of the metabolism of inositol phosphate, which has been considered a potential target for the therapeutic action of lithium in BPAD patients. Given that the PIP5K2A gene is a promising candidate for the development of both disorders, we performed an association study between genetic variants at the PIP5K2A locus and 268 patients with schizophrenia, 260 patients with BPAD and 325 ethnically matched healthy controls. We failed to detect association to either disorder using PIP5K2A gene variants through single‐marker and haplotype analysis. Therefore, our data does not support an involvement of the PIP5K2A locus in the etiology of either schizophrenia or BPAD in the German population. © 2006 Wiley‐Liss, Inc.
A study of the influence of polysaccharides on collagen self‐assembly: Nanostructure and kinetics
Authors: Tsai Shiao‐Wen , Liu Re‐Lin , Hsu Fu‐Yin , Chen Chia‐Chun
Published: July 2006

Collagen, a critical part of the extra‐cellular matrix of tissues, is a popular native material for building scaffolding for tissue‐engineering applications. To mimic the structural and functional profiles of materials found in the native extra‐cellular matrix, numerous efforts have been made toward developing a novel scaffold combining collagen with other biomacromolecules. All of these works have been focused on improving the mechanical or biochemical properties of the collagen‐based matrix. Unfortunately, most of these studies have failed to consider the nanostructure of collagen in the complex matrix. The aim of our study was to investigate the aggregation pattern of collagen after addition of polysaccharides with positive or negative charge, the dose–response relationship, and the effect on reconstitution kinetics. Generally, collagen self‐assembles into fibrils with a diameter of around 95 nm but, in the presence of various polysaccharides in varying amounts, collagen self‐assembles into different shapes with larger diameters compared with collagen alone. Although the morphology and diameter of the collagen fibrils varies with reconstitution conditions, the D‐periods of the fibrils all remained the same regardless of the species or concentration of polysaccharides. The kinetics of fibril formation was determined from turbidity–time curves. All turbidity curves demonstrated that polysaccharides only alter the lag time and time frame of reconstitution, but have no significant effect on the mechanism of reconstitution. Together our data indicate that the presence of biomacromolecules can alter the kinetics and the 3D fibril ultrastructure of assembled collagen and that the consequent structural changes may affect cellular responses in medical applications. © 2006 Wiley Periodicals, Inc. Biopolymers 83:381–388, 2006

This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
MCM‐41 Bound Ruthenium Complex as Heterogeneous Catalyst for Hydrogenation I: Effect of Support, Ligand and Solvent on the Catalyst Performance
Authors: Yu Ying‐Min , Fei Jin‐Hua , Zhang Yi‐Ping , Zheng Xiao‐Ming
Published: July 2006

The functionalized MCM‐41 mesoporous bound ruthenium complex was synthesized and characterized using elemental analysis, atomic absorption spectrophotometer, BET, XRD and FTIR. Hydrogenation of carbon dioxide to formic acid was investigated over these catalysts under supercritical CO2 condition. The effect of reactant gas partial pressure, supports, solvents and ligands on the synthesis of formic acid was studied. These factors could influence the catalyst activity, stability and reuse performance greatly and no byproduct was detected. These promising catalysts also offered the industrial advantages such as easy separation.
Synthesis, X‐ray Crystal Structure and Thermal Decomposition Mechanism of [RbHTNR]∞
Authors: Zheng Hong , Zhang Tong‐Lai , Zhang Jian‐Guo , Qiao Xiao‐Jing , Yang Li , Yu Kai‐Bei
Published: July 2006

A new compound, [RbHTNR]∞ [HTNR−: C6H(NO2)3(OH)O−], was synthesized by the reaction of rubidium nitrate and styphnic acid. The molecular structure was characterized using X‐ray diffraction analysis, elemental analysis and FTIR spectroscopy. The crystalline is monoclinic with space group P21/n and the empirical formula C6H2N3O8Rb. The unit cell parameters are: a=0.4525 nm, b=1.0777 nm, c=1.9834 nm, β=90.47(2)°, V=0.96725 nm3, Z=4, Dc2.263 g/cm3, Mr=329.58, F(000) =640, μ(Mo Kα)=5.165 mm−1. The thermal decomposition mechanism of the complex was studied by differential scanning calorimetry (DSC), thermogravimetry‐derivative thermogravimetry (TG‐DTG) and FTIR techniques. At the linear rate of 10 °C/min, the thermal decomposition of the complex showed three mass reducing processes between 60 and 500 °C, and finally evolved RbCN and some gaseous products.
Lattice Energy Estimation for Complex Inorganic Ionic Crystal
Authors: Mu Lai‐Long , He Hong‐Mei , Feng Chang‐Jun
Published: July 2006

A novel connectivity index mG based on adjacency matrix of molecular graphs was proposed as follows: mG=Σ(gi·gj·gk···)0.5. The element gi of adjacency matrix was defined as gi= (1+Zi1.4)/(1+ri1.4), where Zi and ri are the charge number and the thermochemical radius of ion i respectively, and the radii rifor metal ions are taken to be the Goldschmidt radius. The regression analysis by the connectivity index 1G can provide a high‐quality QSPR model for the lattice energies of 245 complex inorganic ionic crystal samples. The results imply that the lattice energies may be expressed as a linear model of the connectivity index 1G. For the linear model the correlation coefficient r and the standard error s are 0.9998 and 228.72 kJ/mol, respectively. The cross‐validation by the leave‐one‐out method demonstrates that the model is highly reliable from the point of view of statistics.
Synthesis of Styryl‐substituted Z/E‐Chlorin Derivatives with Chlorophyll‐a Skeleton
Authors: Wang Jin‐Jun , Li Jia‐Zhu , Wu Xu‐Ran , Shim Yong Key
Published: July 2006

The Wittig reaction of methyl pyropheophorbide‐d 2, obtained from methyl pyropheophorbide‐a 1, with benzyltriphenylphosphonium bromide was performed to yield isomers 3a and 3b. The Vilsmeier reaction of nickel complex 4 or 7 with 3‐dimethylaminoacrolein in the presence of phosphoryl chloride was carried out to form 20‐meso‐2′‐formylvinylpyropheophorbide‐a 5 or 8, which was reacted with Wittig reagent to afford nickel complex isomers 6a and 6b or 9a and 9b, 10a and 10b.
Characteristic Fragmentation Behavior of Steroidal Phosphor‐ amidate Conjugates in Electrospray Ionization Tandem Mass Spectrometry
Authors: Ji San‐Hao , Ju Yong , Xiao Qiang , Zhao Yu‐Fen
Published: July 2006

Novel steroidal phosphoramidate conjugates of 3′‐azido‐2′,3′‐dideoxythymidine (AZT) and amino acid esters were synthesized and determined by positive and negative ion electrospray ionization mass spectrometry. The MS fragmentation behaviors of the steroidal phosphoramidate conjugates have been investigated in conjunction with tandem mass spectrometry of ESI‐MS/MS. There were three characteristic fragment ions in the positive ion ESI mass spectra, which were the Na adduct ions with loss of steroidal moiety, amino acid ester moiety from pseudo molecular ion (M+Na)+, and the phosphoamino acid methyl ester Na adduct ion by α‐cleavage of the phosphoramidate respectively. The main fragment ions in negative ion ESI mass spectra were the ion (M−HN3)−, the ion (M−AZT−H)−, and the ion (M−steroidal moiety−H)− besides the pseudo molecular ion (M−H)−. The fragmentation patterns did not depend on the attached amino acid ester moiety.
CVD of Zr0.65Ti0.35O2 Thin Films Using a Single‐Source Precursor of Novel Anhydrous Mixed‐Metal Nitrates
Authors: Shao Q. , Li A. , Zhang W. , Wu D. , Liu Z. , Ming N.
Published: July 2006

A novel Zr/Ti mixed metal nitrate[ZrxTi1–x(NO3)4] has been successfully developed as a single‐source precursor to deposit multicomponent metal oxide films. X‐ray photoelectron spectroscopy (XPS) and X‐ray diffraction (XRD) analyses confirm that Zr0.65Ti0.35O2 films are successfully prepared from this anhydrous nitrate precursor using CVD. The basal dielectric properties of Zr0.65Ti0.35O2 films are studied, and well‐defined C–V curves with negligible hysteresis are achieved. Compared to pure TiO2 and ZrO2 films, the Zr0.65Ti0.35O2 films exhibit a trade‐off of dielectric properties with a moderate bandgap value of 4.3 eV and a value for k of 47. ZrxTi1–xO2 is, therefore, a promising candidate for gate‐dielectric application, and an anhydrous mixed‐metal nitrate can be a potential single‐source precursor for high‐k materials derived from CVD.
Direct Synthesis of Macroscopic Multiwalled Carbon Nanotube Ribbons
Authors: Wang Z. , Wang D. , Ji L. , Wu J. , Wang R. , Liang J.
Published: July 2006

Macroscopic multiwalled carbon nanotube ribbons can be directly synthesized through the catalytic decomposition of a ferrocene–xylene mixture in a quartz tube reactor. The ribbons are about 20∼100 μm wide, 10∼30 μm thick, and their length can reach 14 mm in 12 h. The nanotubes in each ribbon are closely compact and parallel to each other along the direction of the ribbon axis.
Adaptive image thresholding for real‐time particle monitoring
Authors: Torabi Keivan , Sayad Saed , Balke Stephen Thomas
Published: July 2006

Image thresholding is critical to computer vision systems designed to detect very small numbers of contaminant particles from analysis of images acquired by in‐line process monitoring. The objective of this work was to obtain a thresholding method that would permit in‐line, “real‐time,” determination of both the number of particles in an image and their size. An additional requirement was that it automatically adapt to inevitable variations in the image quality. A new global image thresholding method, the MaxMin method (“MaxMin”), was developed. MaxMin notes the size of the smallest detected particle in an image as threshold value is progressively changed from black to white. The selected threshold value is the one providing the largest size. MaxMin was tested on thousands of images, and it was shown to readily adapt to images of different background noise levels and provided particle counts as accurate as those of a human observer in less than three seconds per image. Error in particle size measurement was a function of the particle size and the image resolution. It was about 3% for 50 μm particles, using a CCD camera with 2× lens, calibrated for each pixel to represent ∼5 μm2. The error was significantly higher for smaller particles, when the same system resolution was used. © 2006 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 16, 9–14, 2006
New concepts regarding focal adhesion kinase promotion of cell migration and proliferation
Authors: Cox Braden D. , Natarajan Meera , Stettner Michelle R. , Gladson Candece L.
Published: July 2006

Focal adhesion kinase (FAK) is a non‐receptor cytoplasmic tyrosine kinase that plays a key role in the regulation of proliferation and migration of normal and tumor cells. FAK associates with integrin receptors and recruits other molecules to the site of this interaction thus forming a signaling complex that transmits signals from the extracellular matrix to the cell cytoskeleton. Crk‐associated substrate (CAS) family members appear to play a pivotal role in FAK regulation of cell migration. Cellular Src bound to FAK phosphorylates CAS proteins leading to the recruitment of a Crk family adaptor molecule and activation of a small GTPase and c‐Jun N‐terminal kinase (JNK) promoting membrane protrusion and cell migration. The relocalization of CAS and signaling through specific CAS family members appears to determine the outcome of this pathway. FAK also plays an important role in regulating cell cycle progression through transcriptional control of the cyclin D1 promoter by the Ets B and Kruppel‐like factor 8 (KLF8) transcription factors. FAK regulation of cell cycle progression in tumor cells requires Erk activity, cyclin D1 transcription, and the cyclin‐dependent kinase (cdk) inhibitor p27Kip1. The ability of FAK to integrate integrin and growth factor signals resulting in synergistic promotion of cell migration and proliferation, and its potential regulation by nuclear factor kappa B (NFκB) and p53 and a ubiquitously expressed inhibitory protein, suggest that it is remarkable in its capacity to integrate multiple extracellular and intracellular stimuli. J. Cell. Biochem. © 2006 Wiley‐Liss, Inc.
Parkin potentiates ATP‐induced currents due to activation of P2X receptors in PC12 cells
Authors: Sato Ayumi , Arimura Yukiko , Manago Yoshimasa , Nishikawa Kaori , Aoki Kumiko , Wada Etsuko , Suzuki Yasuyuki , Osaka Hitoshi , Setsuie Rieko , Sakurai Mikako , Amano Taiju , Aoki Shunsuke , Wada Keiji , Noda Mami
Published: July 2006

Loss‐of‐function mutations of the parkin gene causes an autosomal recessive juvenile‐onset form of Parkinson's disease (AR‐JP). Parkin was shown to function as a RING‐type E3 ubiquitin protein ligase. However, the function of parkin in neuronal cells remains elusive. Here, we show that expression of parkin‐potentiated adenosine triphosphate (ATP)‐induced currents that result from activation of the P2X receptors which are widely distributed in the brain and involved in neurotransmission. ATP‐induced inward currents were measured in mock‐, wild‐type or mutant (T415N)‐parkin‐transfected PC12 cells under the conventional whole‐cell patch clamp configuration. The amplitude of ATP‐induced currents was significantly greater in wild‐type parkin‐transfected cells. However, the immunocytochemical study showed no apparent increase in the number of P2X receptors or in ubiquitin levels. The increased currents were attenuated by inhibition of cAMP‐dependent protein kinase (PKA) but not protein kinase C (PKC) or Ca2+ and calmodulin‐dependent protein kinase (CaMKII). ATP‐induced currents were also regulated by phosphatases and cyclin‐dependent protein kinase 5 (CDK5) via dopamine and cyclic AMP‐regulated phosphoprotein (DARPP‐32), though the phosphorylation at Thr‐34 and Thr‐75 were unchanged or rather attenuated. We also tried to investigate the effect of α‐synuclein, a substrate of parkin and also forming Lysine 63‐linked multiubiquitin chains. Expression of α‐synuclein did not affect the amplitude of ATP‐induced currents. Our finding provides the evidence for a relationship between parkin and a neurotransmitter receptor, suggesting that parkin may play an important role in synaptic activity. J. Cell. Physiol. 209: 172–182, 2006. © 2006 Wiley‐Liss, Inc.
Snail controls differentiation of hepatocytes by repressing HNF4α expression
Authors: Cicchini Carla , Filippini Daniela , Coen Sabrina , Marchetti Alessandra , Cavallari Claudio , Laudadio Ilaria , Spagnoli Francesca M. , Alonzi Tonino , Tripodi Marco
Published: July 2006

Epithelial‐to‐mesenchymal transition (EMT) is a coordinated process, occurring both during morphogenesis and tumor progression, that allows epithelial cells to dissociate from initial contacts and migrate to secondary sites. The transcriptional repressors of the Snail family induce EMT in different epithelial cell lines and their expression is strictly correlated with EMT during the development and progression of carcinomas. We have previously shown that EMT in hepatocytes correlates with the downregulation of hepatic differentiation key factors HNFs (hepatocyte nuclear factors), and in particular of HNF4α. Here, we demonstrate that Snail overexpression is sufficient (i) to induce EMT in hepatocytes with conversion of morphology, downregulation of several epithelial adhesion molecules, reduction of proliferation and induction of matrix metalloproteinase 2 expression and, (ii) most relevantly, to repress the transcription of the HNF4α gene through a direct binding to its promoter. These finding demonstrate that Snail is at the crossroads of the regulation of EMT in hepatocytes by a dual control of epithelial morphogenesis and differentiation. J. Cell. Physiol. 209: 230–238, 2006. © 2006 Wiley‐Liss, Inc.
Land degradation in northeastern Iceland: present and past carbon fluxes
Authors: Kardjilov M. I. , Gisladottir G. , Gislason S. R.
Published: July 2006

The objectives of this paper are to define the present and past terrestrial fluxes of carbon in three river catchments in northeast Iceland and assess the effect of land degradation and future climate change on the fluxes. The carbon fluxes are: (1) present gross primary production (GPP); (2) net primary production (NPP); (3) net ecosystem exchange (NEE) of terrestrial vegetation in the catchments; (4) river transport out of the catchments of dissolved inorganic carbon (DIC) in 1998; (5) dissolved organic carbon (DOC); (6) river particulate organic carbon (POC); and (7) the average present (prNBE) and (8) past 10 000 years net biome exchange (NBE10 000). The GPP is the largest of the carbon fluxes and increases from west to east as vegetation cover and bedrock age increase. The NPP and NEE, however, were highest in the Jökulsá á Dal catchment where wetlands are extensive. The DIC flux is the largest of the river export fluxes, being highest when the GPP is lowest, dictated by the rapid chemical weathering rate of the young basaltic rocks, rather than vegetation. Thus, a greater portion of the autotrophic and heterotrophic respiration escapes to the atmosphere where the GPP is largest. The NBE10 000 rate increases from west to east. The prNBE is negative and larger than the small positive NBE10 000 flux in the Jökulsá á Fjöllum and it is also negative in the Fellsá catchments, indicating land degradation. Conversely, the prNBE is positive and higher than NBE10 000 in the Jökulsá á Dal catchment, where soil organic carbon stock is increasing. In the future, NBE of two of the three catchments will probably increase because of climate warming and consequently increased vegetation cover and ecosystem stability. Copyright © 2006 John Wiley & Sons, Ltd.
1H and 13C NMR assignments for two new xanthones from the endophytic fungus Xylaria sp. FRR 5657
Authors: Davis Rohan A. , Pierens Gregory K.
Published: July 2006

The complete 1H and 13C NMR assignments are reported for the new natural products, 7‐hydroxy‐3‐(hydroxymethyl)‐1‐methoxy‐9H‐xanthen‐9‐one (1) and 2,5‐dihydroxy‐8‐methoxy‐6‐methyl‐9‐oxo‐9H‐xanthene ‐1‐carboxylic acid (2). Both of these secondary metabolites were isolated from the fermentation culture of the endophytic fungus Xylaria sp. FRR 5657. 1D and 2D NMR experiments that included 1H, gCOSY, gHSQC and gHMBC were used for the determination of the structure and assignment of these xanthones. Copyright © 2006 John Wiley & Sons, Ltd.
PP‐based nanocomposites with various intercalant types and intercalant coverages
Authors: Li Jianming , Ton‐That Minh‐Tan , Tsai Shih‐Jung
Published: July 2006

In this article, nanocomposites based on polypropylene containing montmorillonite, modified with two different intercalants (primary and quaternary amine), at three different coverage levels have been investigated. The specimens were prepared in a mini‐extruder machine with a counter‐rotating configuration. The effectiveness of intercalant type and clay coverage level on the dispersion was analyzed by different means, including X‐ray diffraction analysis, field emission gun scanning electron microscopy, transmission electron microscopy, and differential scanning calorimetry. The flexural performance of the specimens was also examined. POLYM. ENG. SCI. 46:1060–1068, 2006. © 2006 Society of Plastics Engineers
Two representations of the simple model and its application to 4f–5d excitation spectra of Dy3+ dopants in crystals
Authors: Xia S. D. , Duan C. K.
Published: July 2006

The 4f–5d excitation spectra of Dy3+ dopants in crystal YPO4 (in CaF2, LiYF4 as well) reported by van Pieterson et al. [Phys. Rev. B 65, 045114 (2002)] are studied theoretically using both the original and extended simple models without or with the non‐diagonal matrix elements taken into account. When the non‐diagonal matrix elements are taken into account, the same energy levels are obtained in both cases as expected and successfully interpret the 4f–5d spectra. When the non‐diagonal matrix elements are neglected, as in actual applications of the simple models, the results of the original simple model is much closer to the complete‐calculated ones than those of the extended simple model for ion Dy3+. This means the original simple model is more suitable for ion Dy3+. The effect of J ‐mixing of final states on the line strength of transitions due to f‐electron crystal field, which was ignored previously, is also discussed. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Realistic investigations of correlated electron systems with LDA + DMFT
Authors: Held K. , Nekrasov I. A. , Keller G. , Eyert V. , Blümer N. , McMahan A. K. , Scalettar R. T. , Pruschke Th. , Anisimov V. I. , Vollhardt D.
Published: July 2006

Conventional band structure calculations in the local density approximation (LDA) [1–3] are highly successful for many materials, but miss important aspects of the physics and energetics of strongly correlated electron systems, such as transition metal oxides and f‐electron systems displaying, e.g., Mott insulating and heavy quasiparticle behavior. In this respect, the LDA + DMFT approach which merges LDA with a modern many‐body approach, the dynamical mean‐field theory (DMFT), has proved to be a breakthrough for the realistic modeling of correlated materials. Depending on the strength of the electronic correlation, a LDA + DMFT calculation yields the weakly correlated LDA results, a strongly correlated metal, or a Mott insulator. In this paper, the basic ideas and the set‐up of the LDA + DMFT(X) approach, where X is the method used to solve the DMFT equations, are discussed. Results obtained with X = QMC (quantum Monte Carlo) and X = NCA (non‐crossing approximation) are presented and compared, showing that the method X matters quantitatively. We also discuss LDA + DMFT results for two prime examples of correlated materials, i.e., V2O3 and Ce which undergo a Mott–Hubbard metal–insulator and volume collapse transition, respectively. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Pressure induced high spin to low spin transition in magnesiowüstite
Authors: Tsuchiya Taku , Wentzcovitch Renata M. , da Silva Cesar R. S. , de Gironcoli Stefano , Tsuchiya Jun
Published: July 2006

Using a rotationally invariant formulation of LDA + U, we report a successful study of the high spin (HS)/low spin (LS) transition in low solute concentration magnesiowüstite (Mw), (Mg1–x Fex )O, (x < 20%), the second most abundant phase in Earth's lower mantle. The HS state crosses over smoothly to the LS state passing through an insulating mixed spins state where properties change continuously, as seen experimentally. These encouraging results indicate this method should enable first principles studies of strongly correlated iron‐bearing minerals, a major class of mineral physics problems. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Expression of TPK1 and TPK2 genes encoding PKA catalytic subunits during growth and morphogenesis in Candida albicans
Authors: Souto Guadalupe , Giacometti Romina , Silberstein Susana , Giasson Luc , Cantore María Leonor , Passeron Susana
Published: July 2006

The transcript levels of Candida albicans TPK1 and TPK2 genes, encoding PKA catalytic subunits, as well as phosphotransferase activity, were measured in the parental strain CAI4 and in homozygous tpk1Δ and tpk2Δ mutants during vegetative growth and during yeast‐to‐mycelial transition in N‐acetylglucosamine liquid inducing medium at 37 °C. We observed two TPK2 transcripts, a major one of 1.8 kb and a minor one of 1.4 kb, and established by 3′‐RACE that they originate from the recognition of the three polyadenylation signals present in the 3′ untranslated region of the gene. During vegetative growth of CAI4 strain, the expression profiles of TPK1 and TPK2 varied similarly, reaching maximal expression at the late logarithmic phase. TPK1 mRNA levels were lower than those of TPK2 at all stages measured. In the corresponding homozygous tpk mutants, mRNA levels and the expression patterns of TPK1 and TPK2 were similar to those of CAI4, suggesting that the loss of one catalytic isoform is not compensated by overexpression of the other. Changes in PKA specific activity roughly correlated with fluctuations of mRNA expression levels. During yeast‐to‐mycelial transition, a sharp increase in TPK1 mRNA levels and in PKA‐specific activity correlated with the onset of germ‐tube formation in strain tpk2Δ. We also showed that tpk1Δ strain exhibited a delayed morphogenetic shift in comparison with CAI4 and tpk2Δ strains in several liquid inducing media, reinforcing the idea that Tpk1p is important for faster germ‐tube appearance. Copyright © 2006 John Wiley & Sons, Ltd.
Recurrent infections and immunological dysfunction in congenital disorder of glycosylation Ia (CDG Ia)
Authors: Blank C. , Smith L. A. , Hammer D. A. , Fehrenbach M. , DeLisser H. M. , Perez E. , Sullivan K. E.
Published: July 2006

Congenital disorder of glycosylation Ia is the most common defect of glycosylation and is due to mutations in phosphomannomutase 2. This leads to aberrant N‐linked oligosaccharides. The phenotype of CDG Ia reflects the essential nature of glycosylation and patients typically present with multiple organs affected, with hypotonia, developmental delay, inverted nipples and abnormal fat pads. Later features include retinitis pigmentosa, stroke, cerebellar atrophy and malabsorption. Approximately 20% of patients die in the first year of life and infection is the most common cause of death. Immunological function has not previously been investigated in these patients and the critical role of oligosaccharides on adhesion molecules suggested that haematopoietic cell migration and communication could be disrupted by mutations in phosphomannomutase 2. We characterized the clinical features, performed standard immunological evaluations, and performed specific analyses of neutrophil adhesion molecules on two patients to address this question. Patient neutrophils had diminished chemotaxis but expressed comparable levels of adhesion molecules and rolled on artificial endothelium equivalently to control neutrophils. The most significant feature of the patients’ immunological function was poor vaccine responses. These two affected patients were begun on intravenous immunoglobulin with some improvement in their infections.
Three-Dimensional CT Imaging of the Wrist
Authors: JAMES S. E. , RICHARDS R. , McGROUTHER D. A.
Published: July 2006

Three-dimensional computerized tomography provides a new approach to radiological imaging. Raw data from sequential two-dimensional scans have been reconstructed as a three-dimensional model of the carpal area using the Medical Graphics and Imaging Workstation. This study demonstrates the anatomical accuracy and potential diagnostic qualities of a reconstruction of the carpus using this system. The advantages, pitfalls and suggested applications of this technique of carpal imaging are discussed. Three-dimensional imaging is shown to provide a great deal of information which cannot be viewed on conventional radiographs or CT images.
Seventh Cervical Nerve Root Transfer from the Contralateral Healthy Side for Treatment of Brachial Plexus Root Avulsion
Authors: GU Y-D. , ZHANG G-M. , CHEN D-S. , YAN J-G. , CHENG X-M. , CHEN L.
Published: July 2006

Cervical root nerve transfer from the contralateral side has been used for the treatment of brachial plexus root avulsion in 49 patients. Resection of C7 root from the healthy side has produced no long-term symptoms or signs. Nine patients with ten recipient nerves have been followed up for more than two years and seven have obtained a functional recovery. This operation offers a new approach for the treatment of brachial plexus root avulsion.
Is Early Vascularization of Nerve Grafts Necessary?
Authors: MANI G. V. , SHUREY C. , GREEN C. J.
Published: July 2006

Revascularization and regeneration through vascularized and non-vascularized nerve grafts were compared on optimal and adverse graft beds in 76 rabbit sciatic nerves. A delay in revascularization of more than 14 days was found to occur in 30 mm long, non-vascularized nerve grafts placed on completely a vascular graft graft beds. However, over a period of 44 weeks, this prolonged ischaemia did not adversely affect nerve regeneration. The vascularized nerve grafts did not differ significantly with respect to the rate of regeneration, motor conduction velocity, fibre diameter and thickness of myelin sheath. In rabbits, the provision of early vascularity does not appear to confer superior regeneration through nerve grafts. The clinical use of vascularized nerve grafts is discussed in the light of these results.
Factors Affecting the Strength of Flexor Tendon Repair
Authors: BHATIA D. , TANNER K. E. , BONFIELD W. , CITRON N. D.
Published: July 2006

The effects of different thicknesses and configurations of core sutures were studied in human cadaveric flexor tendon repairs. Both straight and cyclic load tests were employed.

To exploit the full strength of 4/0 suture material, the Kessler repair using four locked single knots would seem to be appropriate.
Restoration of the Injured Flexor Tendon Surface: A Possible Role for Endotenon Cells
Authors: ABRAHAMSSON S.-O. , LUNDBORG G. , LOHMANDER L. S.
Published: July 2006

The ability of rabbit deep flexor tendons to restore the gliding surface and to heal, without the normal contribution of the superficial epitenon layer of the tendons, was studied by light and scanning electron microscopy. The epitenon layer was carefully removed from defined segments of the tendons. The remaining central tendon tissue was divided, sutured and placed in diffusion chambers subcutaneously in the back of the rabbits. After two weeks of culture, most of the sutured gaps were bridged and the tendons were encapsulated by flattened and spindle-shaped cells which covered a random network of thin collagen fibres. After five and 11 weeks, fibroblast-like cells in multiple layers formed a cobblestone-like surface. Thus, a tendon deprived of its epitenon layer still contains cells which can produce collagen, bridge the gap and restore the injured tendon surface.
Nail Gun Injuries to the Hand
Authors: KENNY N. W. , KAY P. R. , HAINES J. F.
Published: July 2006

Three cases of nail gun injury to the non-dominant hand are reported. The hazards of using this high powered tool are stressed and a possible pitfall in the surgical removal of the nails is outlined.
Pivot Osteotomy for the Correction of Malunion of Metacarpal Neck Fractures
Authors: THURSTON A. J.
Published: July 2006

A new configuration of osteotomy has been developed which combines the principles and benefits of opening and closing wedge osteotomies without the degree of shortening associated with the closing wedge osteotomy and the tension imposed on the soft tissues by the opening wedge osteotomy. It is ideally suited to the correction of angular malunions in the long bones of the hands. Ten osteotomies of malunions of the metacarpals have been performed in nine hands giving good correction of the malunion in all cases.
Soft Tissue Expanders in Hand Reconstruction
Authors: Mackinnon Susan E. , Dellon A. Lee
Published: July 2006

Eight cases in which soft tissue expanders have been used as an adjunct to reconstruction in the hand are reported. Cases involved reconstruction after skin grafting for burns and crush injuries as well as skin resurfacing in the management of the painful hand. Patient tolerance was excellent and the final result was significantly aided by the use of this technique. The technical details of expansion as well as complications are discussed.
Die klinische Untersuchung des kritisch kranken Patienten auf der Intensivpflegestation
Authors: Rudiger
Published: July 2006

Anamnese und klinische Untersuchung des kritisch kranken Patienten sind auf der Intensivpflegestation (IPS) durch verschiedene Umstände erschwert. Trotzdem spielt die klinische Beurteilung eine zentrale Rolle bei den differentialdiagnostischen Überlegungen und dem Entscheid, welche diagnostischen und therapeutischen Schritte eingeleitet werden. Anamnese und klinische Untersuchung müssen auf der IPS zeitsparend und effizient durchgeführt werden. Damit keine wichtigen Informationen verpasst werden, sollte die Untersuchung strukturiert erfolgen. Dabei hält sich der Untersucher am besten an das Konzept des «A B C», wobei «A» für airways (Atemwege), «B» für breathing (Atmung) und «C» für circulation (Kreislauf) stehen. Der Untersucher muss sich bewusst sein, dass gewisse pathologische Befunde eine umgehende therapeutische Intervention bedingen, bevor die Untersuchung fortgeführt wird. Eine gründliche klinische Untersuchung des Patienten wird normalerweise bei IPS-Eintritt durchgeführt. Manche Untersuchungen können aber aus logistischen Gründen bei Eintritt nicht erhoben werden und müssen zu einem späteren Zeitpunkt nachgeholt werden. Die klinische Untersuchung wird bei den täglichen Visiten wiederholt und wird immer dann durchgeführt, wenn sich der Zustand des Patienten ändert. Der Intensivmediziner muss aufpassen, dass er sich bei der klinischen Untersuchung des Patienten nicht von Laborbefunden und Messwerten technischer Apparate ablenken lässt. Die genaue Dokumentation der klinischen Untersuchungsbefunde ist von zentraler Bedeutung, um den Verlauf des Patienten zu beurteilen und um die Kontinuität der Betreuung zu gewährleisten.
Growth history of a diffusely venting sulfide structure from the Juan de Fuca Ridge: A petrological and geochemical study
Authors: Kristall Brian , Kelley Deborah S. , Hannington Mark D. , Delaney John R.
Published: July 2006

Centimeter‐scale mineralogical and chemical analyses of a diffusely venting, ∼280°C sulfide structure (called Roane) from the Mothra Hydrothermal Field on the Juan de Fuca Ridge reveal a complex growth history. These analyses document four well‐defined zones, which from the exterior to the interior of the structure include a barite‐silica zone (Fossil Worm Tube Zone), a silica‐sulfide zone (Silica Zone), a sulfide‐silica zone (Outer Sulfide Zone), and a sulfide ± gordaite ± silica zone (Inner Sulfide Zone). These features are a product of a myriad of processes that include extensive mineral replacement, ingress of seawater, fracturing and breakout of hot hydrothermal fluids, significant conductive cooling, and the sustained, broad‐scale outflow of warm fluids from the walls through a porous and permeable matrix. Roane lacks an open, throughgoing, chalcopyrite‐lined, central conduit. Instead, it hosts an anastomosing, discontinuous network of tortuous channels within the interior of a sponge‐like matrix of amorphous silica, sulfide, sulfate, and clay minerals. Megafaunal communities at the summit and sides of this mature, diffusely venting chimney provide a constructional framework for new growth. Isolation of hydrothermal fluid from seawater during progressive fossilization of megafauna and the early formation of barite‐silica assemblages promote flow of higher‐temperature fluids within the interior. Continued isolation of interior higher‐temperature fluids, through increased mineral precipitation and expansion of the structure, leads to a Zn sulfide + pyrite‐dominated permeable matrix and a network of tortuous channels that form a central porous conduit. This conduit is shielded by a weakly silicified, metal sulfide inner wall and a strongly silicified outer wall. The most outer portions of the walls are highly porous and sites of significant advection and mixing between hydrothermal fluids and seawater. The mineralogy and chemistry of Roane are strongly affected by ammonia‐ammonium buffering of the pH during cooling of the hydrothermal fluids. The two major results of the buffering are (1) precipitation of Zn sulfide at higher temperatures than are typical for bare‐rock systems, leading to the correlation of Cu, Zn, Cd, and Se and (2) increased deposition of amorphous silica and clay minerals.
Internal wave trapping and mixing in a cold water dome
Authors: Xing Juixing , Davies Alan M.
Published: July 2006

A cross‐sectional nonlinear numerical model of a shallow sea basin containing a cold water dome is used to examine the influence of wind frequency and dome characteristics upon internal waves and mixing. At superinertial forcing frequencies, nonlinear effects in the frontal regions of the dome give rise to propagating internal waves which are reflected by the dome's fronts. This reflection gives a standing internal wave trapped within the dome. The spatial variability of the wave is determined by forcing frequency, stratification and dome length. The magnitude of the internal wave and the length of the dome are related to the horizontal distribution of density in the frontal region. At the inertial frequency there is little internal wave propagation, while at subinertial forcing frequencies the internal wave is trapped in the frontal region, and energy cannot radiate away. Consequently, vertical mixing is enhanced in the frontal regions, while in the center of the dome the mixed layer increases due to the vertical diffusion of the wind's momentum to depth as in a single point model. In the case of wind forcing at a superinertial frequency, there is less mixing in the frontal region with internal wave propagation leading to mixing in the center of the dome. These calculations suggest that the breakdown of cold water domes in response to winter wind events may be due to a number of mixing processes depending upon wind frequency.