bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mutational screening of theCYP26A1gene in patients with caudal regression syndrome
Authors: De Marco Patrizia , Merello Elisa , Mascelli Samantha , Raso Alessandro , Santamaria Andrea , Ottaviano Catherine , Calevo Maria Grazia , Cama Armando , Capra Valeria 
Published: February 2006

AbstractBACKGROUNDThe retinoic acid (RA)–catabolizing enzyme Cyp26a1 plays an important role in protecting tailbud tissues from inappropriate exposure to RA.Cyp26a1‐null animals exhibit caudal agenesis and spina bifida, imperforate anus, agenesis of the caudal portions of the digestive and urogenital tracts, and malformed lumbosacral skeletal elements. This phenotype closely resembles the most severe form of caudal agenesis in humans. In view of these findings, we investigated a potential involvement of the humanCYP26A1gene in the pathogenesis of caudal regression syndrome (CRS).METHODSMutational screening of 49 CRS patients and 132 controls was performed using denaturing high‐performance liquid chromatography and sequencing. Differences in the genotype and allele frequency of each SNP were evaluated by χ2analysis. The biological significance of the intronic variants was investigated by transfection assays of mutant constructs and by analysis of the splicing patterns with RT‐PCR.RESULTSMutational screening allowed us to identify 6 SNPs, 4 of which (447C>G, 1134G>A, IVS1+10G>C, and IVS4+8AG>GA) are new. In addition, we describe a novel 2‐site haplotype consisting of the 2 intronic SNPs. Both single‐locus and haplotype analyses revealed no association with increased risk for CRS. The consequences of the 2 intronic polymorphisms on the mRNA splicing process were also investigated. Moreover, using functional and computational methods we demonstrated that both of these intronic polymorphisms affect the intron splicing efficiency.CONCLUSIONSOur research did not provide evidence thatCYP26A1has implications for the pathogenesis of human CRS. However, the relationship between CRS risk and theCYP26A1genotype requires further study with a larger number of genotyped subjects. Birth Defects Research (Part A), 2006. © 2006 Wiley‐Liss, Inc.
Recent advances in management of patients with platinum‐refractory testicular germ cell tumors
Authors: Kollmannsberger Christian , Nichols Craig , Bokemeyer Carsten 
Published: February 2006

AbstractWith the use of cisplatin‐based combination chemotherapy, metastatic testicular germ cell tumors can be cured in 70–80% of patients, but patients refractory to cisplatin‐based chemotherapy continue to have a very poor prognosis. Various chemotherapeutic agents have been evaluated in intensively pretreated or cisplatin‐refractory patients, but as single agents, only orally administered etoposide, paclitaxel, gemcitabine, and, most recently, oxaliplatin have been shown to be active with selected patients achieving complete remissions. This has for the first time lead to clinical evaluation of combination chemotherapy regimens such as gemcitabine–paclitaxel or oxaliplatin–gemcitabine, demonstrating the feasibility of combination therapy in these heavily pretreated patients. High response rates of up to 45% were observed in particular with the latter combination. Salvage surgery remains a very important treatment option for patients with resectable disease. The molecular mechanisms of cisplatin resistance have been intensively studied, and several mechanisms have been discussed such as a decreased intracellular concentration of the drug, increased repair of the drug‐induced damage, or an altered apoptotic response to this damage. This increasing knowledge may now allow design of new therapeutic options. Ongoing studies in refractory germ cell tumors are evaluating 3‐drug regimens such as gemcitabine–paclitaxel–oxaliplatin but also biologic approaches such as inhibitors of the epidermal growth factor receptor or the vascular endothelial growth factor. This research may eventually allow the development of a noncross‐resistant multidrug combination regimen that can be evaluated in an earlier line of therapy. Cancer 2006. © 2006 American Cancer Society.
Intratumoral hemorrhage among children with newly diagnosed, diffuse brainstem glioma
Authors: Broniscer Alberto , Laningham Fred H. , Kocak Mehmet , Krasin Matthew J. , Fouladi Maryam , Merchant Thomas E. , Kun Larry E. , Boyett James M. , Gajjar Amar 
Published: February 2006

AbstractBACKGROUNDChildren with diffuse brainstem glioma (BSG) commonly undergo novel therapies because their outcome is poor with radiation therapy (RT). Although recent clinical trials using new biologic agents documented intratumoral hemorrhage (IH) among several children with BSG, to the authors' knowledge little is known regarding this phenomenon. In the current study, the authors assessed the characteristics and estimated the cumulative incidence of IH among children with BSG.METHODSAll available brain imaging studies and medical records of 48 consecutive patients with newly diagnosed BSG treated at the study institution over a 10‐year interval (1992–2002) were reviewed. Treatment was comprised of RT and various regimens of conventional chemotherapy; none of these patients received biologic agents. At the time of last follow‐up, all patients had died of tumor progression.RESULTSThe authors reviewed 319 imaging studies (251 magnetic resonance imaging scans and 68 computed tomography scans). IH was present in 6.25% of patients at the time of diagnosis. The 6‐month and 12‐month cumulative incidence estimates of IH regardless of the associated symptoms were 15.5% ± 5.5% and 24.4% ± 6.5%, respectively. The same estimates for symptomatic cases were 8.9% ± 4% and 17.8% ± 6%, respectively. All cases of IH at the time of diagnosis and 78% of symptomatic cases that developed after diagnosis were located in necrotic areas.CONCLUSIONSAlthough IH is uncommon at the time of diagnosis, symptomatic IH may occur among nearly 20% of children after the diagnosis of BSG. The uniform occurrence of IH among patients treated with various chemotherapeutic regimens and its association with necrotic areas suggests that tumor biology plays a significant role in this event. Cancer 2006. © 2006 American Cancer Society.
In situ and Online Monitoring of Hydrodynamic Flow Profiles in Microfluidic Channels Based upon Microelectrochemistry: Optimization of Electrode Locations
Authors: Amatore Christian , Klymenko Oleksiy V. , Svir Irina 
Published: February 2006

AbstractHerein, we extend our previous approach concerning the reconstruction of profiles of pressure‐driven hydrodynamic flow in microfluidic channels based on current measurements at band electrode(s) [see the preceding paper ChemPhysChem 2005, 6, 1581]. We address the central issue of optimization of geometrical parameters describing the electrode(s) assembly (a single band and two bands working in generator–collector mode) within the channel flow cell to enhance the speed and precision of the flow profile reconstruction method.
Optical Properties of Gas‐Phase Tryptophan–Silver Cations: Charge Transfer from the Indole Ring to the Silver Atom
Authors: Antoine Rodolphe , Tabarin Thibault , Broyer Michel , Dugourd Philippe , Mitrić Roland , Bonačić‐Koutecký Vlasta 
Published: February 2006

AbstractWe present a joint experimental and theoretical investigation of the electronic excitation spectra of the tryptophan–silver complex. The photodissociation spectrum of gas‐phase [Trp‐Ag]+was measured from 215 to 330 nm using a quadrupole ion trap coupled to an optical parametric‐oscillator laser. The calculated time‐dependent density functional theory (TD‐DFT) absorption spectra for different prototypes of structures are presented. Low‐energy transitions that are experimentally observed are only calculated for the charge‐solvation (CS) structures. These transitions are a signature of the metal–π interaction in [Trp‐Ag]+. The recorded spectrum is compared to a Boltzmann average of the absorption spectrum obtained from direct molecular dynamics (MD) simulations involving simultaneous transitions to excited states based on semiempirical configuration interaction (CI) calculations. The results demonstrate that charge transfer can be photoinduced from the indole ring to the silver atom.
An improved algorithm for multicast topology discovery from end‐to‐end measurements
Authors: Tian Hui , Shen Hong 
Published: February 2006

AbstractWe present a new multicast topology inference algorithm called binary loss tree classification with hop count (HBLT). HBLT improves the previous algorithm of binary loss tree classification (BLT) not only in time complexity but also in misclassification probability and inference accuracy. The time complexity of HBLT isO(l2) instead ofO(l3) required by BLT in the worst case, andO(l· logl) instead ofO(l3) by BLT in the expected case, wherelis the number of receivers in the multicast network. The misclassification probability of HBLT decreases more quickly than that of BLT as the number of probe packets increases. For correct classification, the inference accuracy of HBLT is always 1, i.e. the inferred tree is identical to the physical tree, whereas that of BLT is dependent on the shape of the physical tree and inversely proportional to the number of internal nodes with single child. We also show through simulation that HBLT requires fewer probe packets to infer the correct topology and hence has a lower misclassification probability and higher inference accuracy than BLT. Copyright © 2006 John Wiley & Sons, Ltd.
Novel Water‐Soluble Carbosilane Dendrimers: Synthesis and Biocompatibility
Authors: Ortega Paula , Bermejo Jesus F. , Chonco Louis , de Jesus Ernesto , de la Mata F. Javier , Fernández Gerónimo , Flores Juan Carlos , Gómez Rafael , Serramía M. Jesús , Muñoz‐Fernandez M. Angeles 
Published: February 2006

AbstractA synthetic strategy has been developed for the preparation of new peripheral amine‐ or ammonium‐terminated carbosilane dendrimers of type nG‐[Si(OCH2CH2NMe2)y]x or nG‐[Si(OCH2CH2NMe3+I–)y]x, respectively. It consists of the alcoholysis of well‐known chlorosilane‐terminated dendrimers with N,N‐dimethylethanolamine and the subsequent quaternization with MeI. All these systems are susceptible to hydrolysis, although the decomposition depends on concentration and dendrimer generation. Evaluation of dendrimer toxicities by phase‐contrast light microscopy and MTT assay were carried out, and evidence of dendrimer/oligonucleotide complex formation was carried out by gel electrophoresis. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Density‐Functional Calculation of the 183W and 17O NMR Chemical Shifts for Large Polyoxotungstates
Authors: Gracia Jose , Poblet Josep M. , Autschbach Jochen , Kazansky Leonid P. 
Published: February 2006

AbstractA phosphane sulfate relativistic DFT method (ZORA)has been used to calculate the 183W and 17O NMR chemicalshifts for large polyoxotungstates, including W6O192–,CH3OTiW5O183–, W5O18WIINO3–, W10O324–, α‐δ‐γ‐XW12O40n–, β‐PW9O28Br63–, P2W18O626–, PW2O143–, and W7O246–, based on their optimized molecular structures. Despite sizeable deviations between the calculated and experimental values, the calculations correctly reproduce the trends in the change of the chemical shift for both nuclei. As expected, the diamagnetic term is almost constant throughout the whole series. The change in the chemical shifts is shown to be determined by the paramagnetic term, which depends on the electronic structure of the whole anion under study and, in particular, on the local geometry around a given tungsten atom. On the other hand, there is no correlation between the chemical shift and HOMO–LUMO gap, showing that deeper occupied levels and several unoccupied orbitals play an important role in the paramagnetic term. However, analysis of the components of the paramagnetic shielding has shown that the most significant transitions determining the change of both 183W and 17O NMR chemical shifts for anions consisting of tungsten and oxygen atoms are the occupied–occupied and not the occupied–virtual ones.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
DFT Calculations of the 183W NMR Chemical Shifts in Reduced Polyoxotungstates
Authors: Gracia Jose , Poblet Josep M. , Fernández Jorge A. , Autschbach Jochen , Kazansky Leonid P. 
Published: February 2006

AbstractA relativistic DFT method (ZORA) is used to calculate the 183W and 17O NMR chemical shifts for the reduced polyoxotungstates W5O18WIINO3–, γ‐SiW12O406–, P2W18O628–, and W10O326– with different degrees of (de)localization of the electrons introduced. Despite some discrepancies in the calculated and experimental data, the calculations adequately describe the changes in the chemical shifts upon reduction. The reduction of a fully oxidized anion is accompanied by an expansion of the geometry. The effect of the charge localization and change in geometry on the chemical shift is evaluated. The shift of the resonance of the tungsten atoms largely depends on the reduced charge acquired upon reduction. On the other hand, those tungsten atoms that do not increase the electron density upon reduction have a negative shift. The calculations also reproduce the negative shifts of all the 17O NMR resonances upon reduction of the polyoxotungstates. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Unexpected Selectivity in Sodium Borohydride Reductions of α‐Substituted Esters: Experimental and Theoretical Studies
Authors: Li Liang‐Chun , Jiang Ju‐Xing , Ren Jie , Ren Yi , Pittman Charles U. , Zhu Hua‐Jie 
Published: February 2006

AbstractThe propensity of sodium borohydride to reduce the carbonyl group in eleven α‐substituted and two aromatic esters has been investigated by experiments and at the B3LYP/6‐31++G(d,p)//HF/6‐31G(d,p) level of theory. The chemoselectivities in nine of these reductions have been examined by experiments. Experimental results agree well with the calculated order of activation energies for hydride transfer to the ester carbonyl group. Methyl α‐bromoacetate reduces faster than methyl α‐fluoroacetate. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Quantitative comparison of AIR, SPM, and the fully deformable model for atlas‐based segmentation of functional and structural MR images
Authors: Wu Minjie , Carmichael Owen , Lopez‐Garcia Pilar , Carter Cameron S. , Aizenstein Howard J. 
Published: February 2006

AbstractTypical packages used for coregistration in functional image analyses include automated image registration (AIR) and statistical parametric mapping (SPM). However, both methods have limited‐dimension deformation models. A fully deformable model, which combines the piecewise linear registration for coarse alignment with demons algorithm for voxel‐level refinement, allows a higher degree of spatial deformation. This leads to a more accurate colocalization of the functional signal from different subjects and therefore can produce a more reliable group average signal. We quantitatively compared the performance of the three different registration approaches through a series of experiments and we found that the fully deformable model consistently produces a more accurate structural segmentation and a more reliable functional signal colocalization than does AIR or SPM. Hum Brain Mapp, 2006. © 2006 Wiley‐Liss, Inc.
Analysis of soil moisture patterns in forested and suburban catchments in Baltimore, Maryland, using high‐resolution photogrammetric and LIDAR digital elevation datasets
Authors: Tenenbaum D. E. , Band L. E. , Kenworthy S. T. , Tague C. L. 
Published: February 2006

AbstractField observations of near‐surface soil moisture, collected over several seasons in a watershed in suburban Maryland, are compared with values of the topographic soil moisture index generated using digital elevation models (DEMs) at a range of grid cell sizes from photogrammetric and light detection and ranging (LIDAR) data sources. A companion set of near‐surface soil moisture observations, DEMs and topographic index values are also presented for a nearby forested catchment. The degree to which topographic index values are an effective indicator of near‐surface soil moisture conditions varies in the two environments. The urbanizing environment requires topographic index values from a DEM with a much finer grid cell resolution than the LIDAR data can provide, and the relationship is stronger in wetter conditions. In the forested environment, the DEM resolution required is considerably lower and adequately supported by the photogrammetric data, and the relationship is strong under all moisture conditions. These results provide some insights into the length scales of near‐surface hydrological processes in the urbanizing environment, and the resolution of terrain data required to model those processes. Copyright © 2006 John Wiley & Sons, Ltd.
One hundred years of mountain hydrology in Switzerland by the WSL
Authors: Hegg Christoph , McArdell Brian W. , Badoux Alexandre 
Published: February 2006

AbstractIn 1903 the Swiss Federal Research Institute WSL started its first forest hydrology measurements with the aim to deliver a sound scientific basis for the implementation of new forest legislation introduced in Switzerland in 1876. This legislation was triggered by several large floods that occurred in Switzerland, for which a major cause was widely seen as the poor condition of forests at that time. Consequently, hydrologic research at WSL first focused on the influence of forests on floods. In the second half of the 20th century, other hydrological issues such as water quality, snow hydrology and sediment transport complemented the hydrologic research at WSL. Some recent results of this work are presented in three papers joining this introductory paper to mark the 100th anniversary of hydrologic research at WSL. Copyright © 2006 John Wiley & Sons, Ltd.
Investigations on the runoff generation at the profile and plot scales, Swiss Emmental
Authors: Badoux Alexandre , Witzig Jonas , Germann Peter F. , Kienholz Hans , Lüscher Peter , Weingartner Rolf , Hegg Christoph 
Published: February 2006

AbstractThis article describes an investigation on runoff generation at different scales in the forested catchment of the Sperbelgraben in the Emmental region (Swiss Prealps) where studies in the field of forest hydrology have a history of 100 years. It focuses on the analysis of soil profiles and the subsequent sprinkling experiments above them (1 m2), as well as on surface runoff measurements on larger plots (50 to 110 m2). In the Sperbelgraben investigation area, two very distinct runoff reactions could be observed. On the one hand, very high production of saturation overland flow was registered on wet areas of gleyic soils, with runoff coefficients between 0·39 and 0·94 for profile irrigation. On the other hand, almost no surface runoff was measured on Cambisols, with the exception at some sites of a hydrophobic reaction detected at the beginning of storms after dry periods (coefficients for profile irrigation: 0·01–0·16). This pattern was observed during 1 m2 soil plot irrigation and on surface runoff plots. Apart from a less distinctive signal of the water‐repellent litter layer on the larger surface runoff plots, the dominant hydrological processes at the two scales are the same. The determined runoff reaction at the two scales corresponds well with information from a forest site type map describing soil and vegetation characteristics and used as a substitute for a soil map in this study. Theoretical considerations describing forest influence on flood discharge are discussed and evaluated to be in good agreement with observations. These findings are a sound foundation for application in hydrological catchment modelling. Copyright © 2006 John Wiley & Sons, Ltd.
Long‐term investigations of the snow cover in a subalpine semi‐forested catchment
Authors: Stähli Manfred , Gustafsson David 
Published: February 2006

AbstractTo improve spring runoff forecasts from subalpine catchments, detailed spatial simulations of the snow cover in this landscape is obligatory. For more than 30 years, the Swiss Federal Research Institute WSL has been conducting extensive snow cover observations in the subalpine watershed Alptal (central Switzerland). This paper summarizes the conclusions from past snow studies in the Alptal valley and presents an analysis of 14 snow courses located at different exposures and altitudes, partly in open areas and partly in forest. The long‐term performance of a physically based numerical snow–vegetation–atmosphere model (COUP) was tested with these snow‐course measurements. One single parameter set with meteorological input variables corrected to the prevailing local conditions resulted in a convincing snow water equivalent (SWE) simulation at most sites and for various winters with a wide range of snow conditions. The snow interception approach used in this study was able to explain the forest effect on the SWE as observed on paired snow courses. Finally, we demonstrated for a meadow and a forest site that a successful simulation of the snowpack yields appropriate melt rates. Copyright © 2006 John Wiley & Sons, Ltd.
High‐frequency logging technologies reveal state‐dependent hyporheic process dynamics: implications for hydroecological studies
Authors: Malcolm I. A. , Soulsby C. , Youngson A. F. 
Published: February 2006

AbstractThis paper presents a novel method for assessing hyporheic water quality dynamics using advances in sensor technology. High‐resolution (15 min) dissolved oxygen (DO) and hydraulic head data were combined to assess groundwater–surface water (GW–SW) interactions in the hyporheic zone. DO concentrations varied at fine temporal and spatial scales, depending on the relative contributions of GW and SW. The effect of sample frequency on observed patterns of variability was assessed with reference to studies of the ecology of salmon spawning habitat. Conventional approaches fail to capture the full range of temporal variability in hyporheic water quality and demonstrate the need to reassess the interpretations of previous studies of the hyporheic zone. © Crown Copyright 2006. Reproduced with the permission of Her Majesty's Stationery Office. Published by John Wiley & Sons, Ltd.