bluuebunny/crossref_metadata_2025_split huggingface dataset:
Validation of neural tube defects in the full featured—general practice research database
Authors: Devine Scott , West Suzanne L. , Andrews Elizabeth , Tennis Pat , Eaton Susan , Thorp John , Olshan Andrew 
Published: March 2008

AbstractBackgroundThe General Practice Research Database (GPRD) has been used to identify associations between pregnancy medication exposures and birth defects, but experts have argued that databases such as this one cannot provide detailed information for the valid identification of complicated congenital anomalies. Our objective was to determine if the GPRD could be used to identify cases of neural tube defects (NTDs).MethodsFirst, we created algorithms for anencephaly, encephalocele, meningocele, and spina bifida and used them to identify potential cases. We used the algorithms to identify 217 potential NTD cases in either a child's or a mother's record. We validated cases by querying general practitioners (GPs) via questionnaire. Where cases of NTD were identified in the mother's record, in addition to confirming the diagnosis, we asked the GPs if the diagnosis was for the mother or that of her fetus or offspring.ResultsTwo hundred seventeen cases were identified, and 165 GP questionnaires were returned. We validated an NTD diagnosis for 117 cases, giving our algorithms a positive predictive value (PPV) of 0.71. The PPVs varied by NTD type: 0.81 for anencephaly, 0.83 for cephalocele, 0.64 for meningocele, and 0.47 for spina bifida.ConclusionsOur identification algorithm was useful in identifying three of the four types of NTDs studied. Additional information is necessary to accurately identify cases of spina bifida. Copyright © 2008 John Wiley & Sons, Ltd.
Proteome analysis of ventral midbrain in MPTP‐treated normal and L1cam transgenic mice
Authors: Diedrich Madeleine , Mao Lei , Bernreuther Christian , Zabel Claus , Nebrich Grit , Kleene Ralf , Klose Joachim 
Published: March 2008

AbstractTreatment of mice by 1‐methyl‐4‐phenyl‐1,2,3,6‐tetrahydropyridene hydrochloride (MPTP) is a well established animal model for Parkinson's disease (PD), while overexpression of L1 cell adhesion molecule (L1cam) has been proposed to attenuate the degeneration of dopaminergic neurons induced by MPTP. To gain insight into the role of L1cam in the pathomechanism of PD, we investigated protein expression patterns after MPTP‐treatment in both C57BL/6 (wild‐type) and transgenic mice overexpressing L1cam in astrocytes. Our results showed that during the acute phase, proteins in functional complexes responsible for mitochondrial, glycolysis, and cytoskeletal function were down‐regulated in MPTP‐treated wild‐type mice. After a recovery phase, proteins that were down‐regulated in the acute phase reverted to normal levels. In L1cam transgenic mice, a much higher number of proteins was altered during the acute phase and this number even increased after the recovery phase. Many proteins involved in oxidative phosphorylation were still down‐regulated and glycolysis related protein were still up‐regulated. This pattern indicates a lasting severely impaired energy production in L1cam mice after MPTP treatment.
An easy‐to‐use Decoy Database Builder software tool, implementing different decoy strategies for false discovery rate calculation in automated MS/MS protein identifications
Authors: Reidegeld Kai A. , Eisenacher Martin , Kohl Michael , Chamrad Daniel , Körting Gerhard , Blüggel Martin , Meyer Helmut E. , Stephan Christian 
Published: March 2008

AbstractOne of the major challenges for large scale proteomics research is the quality evaluation of results. Protein identification from complex biological samples or experimental setups is often a manual and subjective task which lacks profound statistical evaluation. This is not feasible for high‐throughput proteomic experiments which result in large datasets of thousands of peptides and proteins and their corresponding mass spectra. To improve the quality, reliability and comparability of scientific results, an estimation of the rate of erroneously identified proteins is advisable. Moreover, scientific journals increasingly stipulate that articles containing considerable MS data should be subject to stringent statistical evaluation. We present a newly developed easy‐to‐use software tool enabling quality evaluation by generating composite target‐decoy databases usable with all relevant protein search engines. This tool, when used in conjunction with relevant statistical quality criteria, enables to reliably determine peptides and proteins of high quality, even for nonexperienced users (e.g.laboratory staff, researchers without programming knowledge). Different strategies for building decoy databases are implemented and the resulting databases are characterized and compared. The quality of protein identification in high‐throughput proteomics is usually measured by the false positive rate (FPR), but it is shown that the false discovery rate (FDR) delivers a more meaningful, robust and comparable value.
PMMA colloid particles armored by clay layers with PDMAEMA polymer brushes
Authors: Zhang Jian , Chen Kaiqiang , Zhao Hanying 
Published: March 2008

AbstractPoly[2‐(dimethylamino) ethyl methacrylate] (PDMAEMA) brushes on the surfaces of clay layers were prepared by in situ free‐radical polymerization. Poly (methyl methacrylate) (PMMA) colloid particles stabilized and initiated by clay layers with PDMAEMA polymer brushes were prepared by Pickering emulsion polymerization. Transmission electron microscopy was used to characterize the structure and morphology of the colloid particles. The X‐ray diffraction (XRD) results indicated that the intercalated structures of the clay layers were almost destroyed in Pickering emulsion polymerization, and clay layers with exfoliated structures were created. The surface of the colloid particles was analyzed by using X‐ray photoelectron spectroscopy (XPS). The XPS results provide direct evidence that the clay layers with PDMAEMA chains cover the PMMA colloid particles. © 2008 Wiley Periodicals, Inc. JPolym Sci Part A: Polym Chem 46: 2632–2639, 2008
Study on the preparation and the self‐assembly of poly(propyleneimine)–poly(styrene) nanoparticles
Authors: Zhu Yanjin , Xu Zushun , Yi Changfeng 
Published: March 2008

AbstractUsing 2‐chloropropionamide derivative of poly(propyleneimine) dendrimer DAB‐dendr‐(NH2)32 (DAB‐32‐Cl) as the macroinitiator, atom transfer radical polymerization of styrene was successfully carried out in DMF medium. The monodisperse poly(propyleneimine)–polystyrene (dendrimer–PSt) particles with diameters smaller than 100 nm could be prepared. The morphology, size, and size distribution of the dendrimer–PSt particles were characterized by transmission electron microscopy (TEM) and photon correlation spectroscopy (PCS). The effects of reaction temperature, the ratio of St/macroinitiator, and reaction time on the size, and size distribution of the dendrimer–PSt nanoparticles were investigated. In a selective solvent (DMF/H2O), polymers can self‐assemble into different aggregate configurations such as regular microsphere and wire‐like thread. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 2658–2666, 2008
4,9‐Dihydro‐s‐indaceno[1,2‐b:5,6‐b′]dithiophene‐4,9‐dione functionalized copolymers for organic photovoltaic devices
Authors: Zhao Chunchang , Chen Xiaohong , Zhang Yong , Ng Man‐kit 
Published: March 2008

AbstractThe synthesis of conjugated polymers 1–5 functionalized with 4,9‐dihydro‐s‐indaceno[1,2‐b:5,6‐b′]dithiophene‐4,9‐dione in the backbone is reported and their use in the construction of organic solar cells is demonstrated. Increasing the molar ratio of 2,7‐dibromo‐3,8‐dihexyl‐4,9‐dihydro‐s‐indaceno[1,2‐b:5,6‐b′]dithiophene‐4,9‐dione, relative to 4,4′‐dihexyl‐5,5′‐dibromo‐2,2′‐bithiophene, in the copolymer synthesis significantly lowers the solubility of these polymers. The incorporation of highly conjugated 3,8‐dihexyl‐4,9‐dihydro‐s‐indaceno[1,2‐b:5,6‐b′]dithiophene‐4,9‐dione unit into the polymer backbone has been confirmed by UV–vis absorption. The observation of decreasing quantum yield for the emission in the order of 1, 2, 3 is consistent with copolymers with different comonomer content. The power conversion efficiencies of solar cells using blends of these polymers with PCBM ([6,6]‐phenyl C61‐butyric acid methyl ester) were determined to be 0.11% for polymer 1, 0.33% for 2, and 0.26% for 3, respectively. Under identical white light illumination, the power conversion efficiency of the device based on polymer 2/PCBM as the active layer was three times higher compared to that of device based on polymer 1/PCBM. Owing to the limited solubility and poor film‐forming ability of polymer 3, the power conversion efficiency of solar cell based on 3/PCBM blend is lower than that of 2/PCBM blend, but is still larger than that of 1/PCBM blend. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 2680–2688, 2008
Self‐assembled organic nanotubes: Toward attoliter chemistry
Authors: Shimizu Toshimi 
Published: March 2008

AbstractDiverse chemical functionalization of the inner and outer surfaces of the nanotubes enables us to sense and visualize the encapsulation and transport behavior of biomacromolecular guests. The event occurs specifically in attoliter volume nanospace inside the hollow cylinder of the nanotubes. Comparison of the organic nanotube history with that of well‐known carbon nanotubes and a variety of molecular building blocks as tube‐forming compounds were first introduced. Asymmetric organic nanotubes with different inner and outer surfaces were discussed in terms of molecular design, immobilization of functional moieties, and molecular packing. Finally, the practical examples of the organic nanotubes as a nanocontainer, nanochannel, and nanopipette were also described to feature the concept of “attoliter chemistry.” © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 2601–2611, 2008
Spectral time moment analysis of microgel structure and dynamics
Authors: Streletzky Kiril A. , McKenna John T. , Mohieddine Rami 
Published: March 2008

AbstractThe structure and dynamics of crosslinked nanoparticles (microgels) made out of hydroxypropylcellulose (HPC) polymer chains were studied using dynamic light scattering spectroscopy. The microgel light scattering spectra were found to be highly nonexponential requiring a spectral time moment analysis in which the spectra were fit to a sum of stretched exponentials. Each term offers three parameters for analysis and represents a single spectral mode. At room temperature microgel spectra reveal three modes. Two faster modes are almost diffusive and correspond to apparent sizes of 25 and 450–650 nm. The slowest mode is independent of scattering angle and is reminiscent of the slow polymer mode observed in identical non‐crosslinked polymer solutions. When solution temperature is varied from 23 to 45°C and back, the microgel undergoes a reversible volume phase transition between 40 and 45°C. According to the time‐moment analysis, above the transition temperature two faster modes collapse into one with apparent hydrodynamic radius of 100–150 nm, while the slow mode remains largely unchanged. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 771–781, 2008
Supramolecular micellization and pH‐inducible gelation of a hydrophilic block copolymer by block‐specific threading of α‐cyclodextrin
Authors: Yuan Renxu , Shuai Xintao 
Published: March 2008

AbstractA poly(ethylene glycol)‐b‐poly(L‐lysine) diblock copolymer (PEG‐b‐PLL) was synthesized. Micellization of this hydrophilic copolymer due to the block‐specific threading of α‐cyclodextrin (α‐CD) molecules onto the polyethylene glycol (PEG) block yielded supramolecular‐structured nanoparticles, which undergoes pH‐inducible gelation in aqueous media. The pH‐inducible gelation of supramolecular micelle in water appeared to be completely reversible upon pH changes. The synergetic effect of selective complexation between PEG block and α‐CD and the pH‐inducible hydrophobic interaction between PLL blocks at pH 10 was believed to be the driving force for the formation of the supramolecular hydrogel. 1H NMR and wide angle X‐ray diffraction (WAXD) were employed to confirm the inclusion complexation between α‐CD and PEG block. Meanwhile, the morphology of the micellized nanoparticles was investigated by transmission electron microscopy (TEM). The thermal stability of inclusion complexes (ICs) was investigated and the rheologic experiment was conducted to reveal the micelle‐gel transition. Such pH‐induced reversible micelle‐gel transition of the supramolecular aggregates may find applications in several fields, for example as advanced biomedical material possessing stimulus‐responsiveness. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 782–790, 2008
GaN and ZnO freestanding micromechanical structures on silicon‐on‐insulator substrates
Authors: Tripathy S. , Vicknesh S. , Wang L. S. , Lin V. K. X. , Oh S. A. , Grover R. , Zang K. Y. , Arokiaraj J. , Tan J. N. , Kumar B. , Gong H. , Shannigrahi S. R. , Ramam A. , Chua S. J. 
Published: March 2008

AbstractUsing a combination of selective dry etching techniques, surface micro‐machined GaN and ZnO micromechanical structures are demonstrated on silicon‐on‐insulator (SOI) substrates. The dry releasing technique employs a controlled gas phase pulse etching with non‐plasma xenon difluoride (XeF2), which selectively etches the Si overlayer of SOI, thus undercutting the wide bandgap semiconductor material on top. This method prevents crystal damage of overhanging wide bandgap semiconductor mechanical structures. The mechanical properties of these released microstructures are characterized by micro‐Raman spectroscopy. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Silver nanoparticles embedded in polymer matrices ‐ a FTIR‐SE study
Authors: Dahmouchène Nora , Coppée Séverine , Voué Michel , De Coninck Joel 
Published: March 2008

AbstractThe optical properties of silver nanoparticles embedded in a poly (vinyl) alcohol matrix have been investigated using Fourier transform infrared spectrocopic ellipsometry (600 and 6000 cm–1). An atomic force microscopy analysis showed that the particles were nearly spherical and that their average size was ≃20 nm. The extinction coefficient spectrum of the annealed films reveals the major peaks associated with polyvinyl alcohol, as well as two additionnal peaks located at 1134 and 1036 cm–1, suggesting the presence of bonds between Ag and the polymer matrix. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Ellipsometric characterization of flagellin films for biosensor applications
Authors: Kozma P. , Nagy N. , Kurunczi S. , Petrik P. , Hámori A. , Muskotál A. , Vonderviszt F. , Fried M. , Bársony I. 
Published: March 2008

AbstractThe quality of flagellin films in terms of thickness and homogeneity was investigated by spectroscopic ellipsometry. Flagellin films were prepared in three steps: silanization, glutaraldehyde activation and finally the coating with proteins. The process of film preparation was optimized by varying the duration of the silanization and by testing sticking on different substrates including Si wafer covered with different thickness of silicon‐oxide and also covered with a thin film of tantallum pentoxide. Spectroscopic ellipsometry was applied to gain in‐depth information on the film properties for the optimization of the immobilization. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Defect profiling by ellipsometry using ion implantation through wedge masks
Authors: Fried M. , Khanh N. Q. , Petrik P. 
Published: March 2008

AbstractWe measured 3.5 MeV energy He‐ and N‐implanted Si by spectroscopic ellipsometry (SE) and Rutherford backscattering/channeling spectrometry (RBS/C). The He and N ions were implanted in the range of 1–5x1016/cm2 and 0.2–1.2x1016/cm2, respectively through a wedge‐shape silicon membrane (∼4.5 micron/mm slope) which was fixed to the target wafer and was moved laterally to the ion beam spot causing the disorder (mainly point defects) profile “moving” in depth. The doses and energies were in both cases set to have all the positions of the Gaussian damage at the surface, and to cover the damage range from slightly damaged to the maximum. We used ∼0.1 mm wide measuring spots for both SE and RBS/C making possible to “scan” the disorder profiles with ∼0.5 micron depth resolution. Several nm thick, surface amorphous damage peak was observed with low level (far below the modified Kinchin‐Pease model predictions) point defect region beneath the surface, possibly due to dynamic annealing processes. Using critical point analysis we make an attempt to determine the optical response (dielectric function) of the point defects or defect complexes. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Cu underpotential deposition on Au controlled by in situ Spectroscopic Ellipsometry
Authors: Prato Mirko , Gussoni Antonio , Panizza Marco , Cavalleri Ornella , Mattera Lorenzo , Canepa Maurizio 
Published: March 2008

AbstractWe have studied Cu electrodeposition on well defined Au films using real time Spectroscopic Ellipsometry (SE). SE allows to discriminate the under‐potential (UP) and over‐potential (OP) regimes. In the UP regime, tiny yet reproducible variations of Ψ and Δ parameters indicate the formation of two phases with slightly different optical behavior. The phase at the largest coverage is assigned to a Cu monolayer. The SE response in the OP regime shows a marked dependence on the potential scan rate. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Complex dielectric function of ion implantation amorphized SiC determined by spectroscopic ellipsometry
Authors: Lohner T. , Zolnai Z. , Petrik P. , Battistig G. , Garcia López J. , Morilla Y. , Koós A. , Osváth Z. , Fried M. 
Published: March 2008

AbstractMeasuring with a spectroscopic ellipsometer we determined the complex dielectric function of completely amorphous silicon carbide prepared by ion implantation. 860 keV Ni+ ions were implanted into single crystalline 4H‐SiC to produce thick amorphized layer. Ion beam analysis was applied to assess total amorphization. For this purpose 4He+ ion beam of 3.5 MeV was selected taking the advantage that the scattering cross section of carbon at this energy at 165° detection angle is about six times larger than the Rutherford type. Atomic force microscopy was performed to characterize the roughness of the ion‐implanted surfaces. Multiple energy Ar+ implantation was used to produce homogeneous amorphous layer. The Tauc‐Lorentz model was applied for the evaluation of the ellipsometric results. The implantation‐induced swelling was obtained through the measurement of the step height across the masked and implanted areas. Comparison was made among the complex dielectric functions of amorphized SiC studied by us and by different research groups. It is found that the complex dielectric functions of amorphized SiC differ considerably if different ion implantation conditions were applied. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optical response of nanostructured GaSb
Authors: Kildemo M. , Nerbø I. S. , Søndergård E. , Holt L. , Simonsen I. , Stchakovsky M. 
Published: March 2008

AbstractOptical measurements of nanostructured GaSb prepared by sputtering is presented. The optical response is studied by Mueller Matrix Ellipsometry (MME) in the visible range (430‐850 nm), and by spectroscopic ellipsometry in the range 0.6‐6.5 eV. The nano‐structured surfaces reported in this work, consist of densely packed GaSb cones approximately 50 nm high, on bulk GaSb. The nanostructured surfaces are here shown to considerably modify the optical response of the surface, hence giving a strong sensitivity to the far field spectroscopic (Mueller matrix) ellipsometric measurements. The off‐specular scattering and the depolarization is found to be low. The anisotropic response is particularly emphasized by studying nano‐structured GaSb cones approximately 45 degrees tilted with respect to the surface normal. In the latter case, one observes upon rotating the sample around the surface normal, that the Mueller matrix elements m13 and m14 oscillate as a function of the rotation angle. Finally, Mueller matrix techniques have been applied to the measured data, in order to analyze the acquired Mueller matrix in terms of physical realisability and noise. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A process capability/customer satisfaction approach to short‐run processes
Authors: Spiring Fred 
Published: March 2008

AbstractShort‐run processes pose many challenges to standard statistical process control methodologies. Classical short‐run approaches attempt to standardize the measurements before applying traditional control procedures. A technique is proposed that standardizes the measurements from a customer satisfaction perspective and then uses small sample process capability techniques to provide analytical control mechanisms for a class of short‐run processes. Examples motivated from a print shop are used to illustrate the procedures. Copyright © 2008 John Wiley & Sons, Ltd.
A Combined 2D‐ and 3D‐QSAR Study on Analogues of ARC‐111 with Antitumor Activity
Authors: Liao Si Yan , Qian Li , Lu Hai Liang , Shen Yong , Zheng Kang Cheng 
Published: March 2008

AbstractTwo‐Dimensional (2D) and Three‐Dimensional (3D) Quantitative Structure–Activity Relationships (QSARs) of a series of analogues of ARC‐111 with antitumor activity expressed as pIC50, which is defined as the negative value of the logarithm of necessary molar concentration of these compounds to cause 50% growth inhibition against tumor cell lines P388, have been studied by using a combined method of the DFT, MM2, and statistics for 2D, as well as the Comparative Molecular Field Analysis (CoMFA) for 3D. The established 2D‐QSAR model shows not only significant statistical quality, but also predictive ability, with the square of adjusted correlation coefficient $\rm{ R_{\rm{A}}^{\rm{2}} }$ of 0.869 and the square of the crossvalidation coefficient q2 of 0.834 as well as the square of predictive correlation coefficient $\rm{ R_{{\rm{pred}}}^{\rm{2}} }$ of 0.867 for the test set. The 3D‐QSAR model also shows good correlative and predictive capabilities in terms of R2 (0.993) and q2 (0.674) when CoMFA fields are used for the whole studied compounds. The results from 2D‐ and 3D‐QSAR analyses conformably show that the steric interaction plays a crucial role in determining the cytotoxicity of the compounds and that selecting a moderate‐size substituent R as well as increasing the negative charge of C28 at the same time are advantageous to improving the antitumor activity. Such results might offer some useful theoretical references for understanding the action mechanism and directing the molecular design of this kind of compound with antitumor activity.