bluuebunny/crossref_metadata_2025_split huggingface dataset:
Investigation of confined placental mosaicism (CPM) at multiple sites in post‐delivery placentas derived through intracytoplasmic sperm injection (ICSI)
Authors: Minor Agata , Harmer Karynn , Peters Nicole , Yuen Basil Ho , Ma Sai 
Published: December 2005

AbstractAlthough earlier studies on pregnancies derived through intracytoplasmic sperm injection (ICSI) reported increased non‐mosaic aneuploidy among ICSI children, undetected mosaicism, such as confined placental mosaicism (CPM) has not been evaluated. We investigated the incidence of CPM in post‐delivery placentas derived from ICSI, evaluated whether CPM was increased and whether it was a contributing factor to negative pregnancy outcome. [Fifty‐one post‐delivery placentas were collected from patients who underwent ICSI with a normal or negative pregnancy outcome]. Trophoblast and chorionic stroma from three sites were analyzed by comparative genomic hybridization (CGH) and flow cytometry. Detected abnormalities were confirmed by fluorescence in situ hybridization (FISH). The incidence of CPM in the ICSI population was compared to the general population from published data. We detected three cases of CPM in our study. One abnormality was found by CGH analysis; partial trisomy 7q and a partial monosomy Xp limited to the trophoblast at two sites. The abnormality was associated with a child affected by spina bifida. Two cases of mosaic tetraploidy were observed by flow cytometry in pregnancies with a normal outcome. All three abnormalities were confirmed by FISH analysis. The incidence of CPM in the ICSI study population was 5.88% (3/51), which was not statistically different from published reports in the general population (5.88% (42/714), Chi square, P > 0.05). The post‐ICSI population was not at risk for CPM in this study. © 2005 Wiley‐Liss, Inc.
Adverse reproductive outcomes among pregnancies of aunts and (spouses of) uncles in Irish families with neural tube defects
Authors: Byrne Julianne , Carolan Susan 
Published: December 2005

AbstractAdverse pregnancy outcomes may be more frequent among sibs of individuals with neural tube defects (NTDs), and transmission of risk in families with an NTD may be more frequent among maternal relatives. In a study designed to evaluate matrilineal risk for NTDs, we compared adverse pregnancy outcomes among maternal and paternal first cousin pregnancies. Pregnancy histories were obtained by interview with 288 uncles and aunts (parents of the first cousin pregnancies) in 48 Irish NTD families. We analyzed pregnancy outcomes (preterm deliveries, stillbirths, and miscarriages) among 1,033 singleton first cousin pregnancies and compared risk among maternal versus paternal relatives. Maternal first cousin pregnancies were more likely to end adversely when compared to paternal first cousin pregnancies (17.4% vs. 11.7%, P = 0.01). In a logistic regression analysis of pregnancies unaffected by birth defects, maternal line remained independently associated with adverse outcomes (odds ratio (OR) = 1.55, 95% confidence interval (CI) 1.06, 2.27) after controlling for NTD type, maternal age, maternal smoking during pregnancy, first cousin pregnancy's year of birth. The excess risk with maternal line related mainly to spina bifida occulta families (OR = 42.4; CI 2.64, 681; P = 0.008); risk in open spina bifida families was 1.24 (CI 0.82, 1.87; P = 0.3). These results support the hypothesis of excess risk for adverse pregnancy outcomes among maternal relatives in NTD families. Further work is needed, epidemiological as well as clinical and molecular, not only to confirm these findings, but also to define the underlying biological mechanisms linking adverse reproductive outcomes, excess maternal risk and occurrence of NTDs. © 2005 Wiley‐Liss, Inc.
Supported hybrid catalysts based on zirconocene and tris(pyrazolyl)borate titanium derivatives
Authors: Pires Gilvan P. , Gil Marcelo P. , Rohrman Juliana A. , Stedile Fernanda C. , Casagrande Osvaldo L. , dos Santos João H. Z. , Sano Tsuneji 
Published: December 2005

AbstractA series of hybrid supported catalysts were prepared by combining (iBuCp)2ZrCl2 and {TpMs*}TiCl3 complex (TpMs* = HB(3‐mesityl‐pyrazolyl)2(5‐mesityl‐pyrazolyl)−) sequentially grafted onto MAO (methylaluminoxane)‐modified silica according to a Plackett Burmann 23 design. Supported catalysts were prepared taking into account the immobilization order, silica pretreatment temperature, and grafting temperature. Grafted metal content was comparatively determined by Rutherford backscattering spectrometry (RBS), X‐ray photoelectronic spectroscopy (XPS), and inductively coupled plasma–optical emission spectroscopy (ICP–OES). The resulting catalysts were evaluated in terms of catalyst activity and polymer properties. According to RBS measurements, grafted metal content remained comprised between 0.1 and 0.5 wt % Zr/SiO2 and 0.1 and 0.3 wt % Ti/SiO2 depending on the immobilization order and on silica pretreatment temperature. All the systems were shown to be active in ethylene polymerization having external MAO as cocatalyst. Catalyst activity seemed to be governed by the zirconocene species, influenced slightly by Ti ones. Resulting polymers were characterized by DSC and GPC. The polyethylenes mostly presented higher molecular weight than those produced by homogeneous catalysts or by zirconocene grafted on bare or on MAO‐modified silica. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci, 2006
Mechanical, thermomechanical, and morphology of PVC/PBMA blends and full IPNs
Authors: Bhattacharyya Rupa , Roy Neelanjan , Chakraborty Debabrata 
Published: December 2005

AbstractBlends and full IPNs' of poly(vinyl chloride) and polybutylmethacrylate (PBMA) have been synthesized and characterized with respect to their mechanical, thermomechanical, and morphological properties. Both the systems displayed a rise in the modulus and ultimate tensile strength and a consequent decreasing tendency of elongation at break and toughness are exhibited. The influence of crosslinking of the two polymers as has been done in case of full IPNs over the ordinary blends is quite well understood from these properties. The thermomechanical analysis revealed a substantial rise in stability with increasing methacrylate concentration in the system and this is quite apparent from the softening characteristics of the different samples under study. The biphasic cocontinuous systems as explicit from the morphological studies support phase mixing at the initial stages, with subsequent phasing out tendency with increasing percentage of PBMA incorporation. The thermomechanical parameters are in conformity to their mechanicals which have been further supported by their morphological studies. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci, 2006
Synthesis of chelate resins derived from furfural and their adsorption properties for metal ions
Authors: Zhou Lin‐Cheng , Li Yan‐Feng , Zhang Shu‐Jiang , Chang Xi‐Jun , Hou Ying‐Feng , Yang Hai‐Xia 
Published: December 2005

AbstractA series of new chelate resins were synthesized by ring‐opening polycondensation of the reaction mixture of furfural with diethanolamine, using sulfuric acid as a catalyst, and the resulting chelate resins were employed in the adsorption for metal ions Bi, In, Sn, V, Ga, Y, Ti, and Pb. The composition, structure, and properties of the resulting chelate resin were studied by means of fourier transform infrared (FTIR), electron paramagnetic resonance spectrum (EPR), and elemental analysis methods. Meanwhile, the adsorption properties of the resulting chelate resins for the above metal ions were investigated by inductively‐coupled plasma–atomic emission spectrometry (ICP‐AES) procedures. The results show that the resulting chelate resins hold the structure consisting of hydroxyl groups, amine groups, and conjugated π bonds, as well as more crosslinkages, and so they exhibit a good reactivity and chemical stability. The adsorption experiments show that the chelate resins could well adsorb V, Ga, Y, Ti, and Pb in a wider acidity range and exhibit a good adsorption selectivity. Particularly, the chelate resins could adsorb and desorb for Pb, Bi, In, V, Y, and Ti, quantitatively, in the given conditions. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 1620–1626, 2006
Rheological properties of polypropylene modified by high‐intensity ultrasonic waves
Authors: Kim K. Y. , Nam G. J. , Lee S. M. , Lee J. W. 
Published: December 2005

AbstractA new method using high‐intensity ultrasonic waves, instead of peroxide‐aided reactive extrusion, was applied to modify a linear polypropylene into a branched structure. The ultrasonic waves induced chain scission and created reactive macromolecules of polypropylene successfully in the melt state without any peroxide. To enhance and control the recombination reaction during sonication, a multifunctional agent and an antioxidant were used. The rheological property measurements clearly confirmed that the modified polypropylene had a nonlinear branched structure. It showed shear‐thinning behaviors in its viscosities at low frequencies, high elastic behaviors in Cole–Cole plots, and a high rheological polydispersity index in comparison with a linear polypropylene. The degradation or recombination of polypropylene was adequately controlled by an antioxidant, which stabilized the structure during sonication. Also, the use of an antioxidant was quite effective in improving the extrusion processability by delaying the instability of the extrudate to a higher shear rate. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci, 2006
Comparison of the guarded‐heat‐flow and transient‐plane‐source methods for carbon‐filled nylon 6,6 composites: Experiments and modeling
Authors: Miller Michael G. , Keith Jason M. , King Julia A. , Hauser Rebecca A. , Moran Angela M. 
Published: December 2005

AbstractIn this study, two different carbons (synthetic graphite particles and carbon fiber) were added to nylon 6,6, and the resulting composites were tested for thermal conductivity. The first goal of this work was to compare through‐plane thermal conductivity results from the guarded‐heat‐flow method and the transient‐plane‐source method. The results showed that both test methods gave similar through‐plane thermal conductivity results for composites containing 10–40 wt % synthetic graphite and for composites containing 5–40 wt % carbon fiber. The advantages of using the transient‐plane‐source method were that the in‐plane thermal conductivity was also measured and the experimental time was shorter than that of the guarded‐heat‐flow method. The second goal of this work was to develop and use a detailed finite‐element analysis to model heat transfer within a carbon‐filled nylon 6,6 composite sample for the transient‐plane‐source method and compare these results to actual experimental results. The results showed that the finite‐element model compared well with the actual experimental data. The finite‐element model could be used in the future as a design tool to predict the dynamic thermal response of different composite materials for many applications. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci, 2006
A “Grapple Hook” technique using a deflectable tip catheter to facilitate complex proximal circumflex interventions
Authors: McNulty Edward , Cohen Joshua , Chou Tony , Shunk Kendrick 
Published: December 2005

AbstractWe present two patients with angulated, proximal left circumflex lesions, one a chronic total occlusion and one an acute subtotal occlusion. In both cases, use of the deflectable tip Venture Catheter (Velocimed, Minneapolis, MN) facilitated guide wire passage and successful percutaneous coronary intervention (PCI) after prior attempts at guide wire passage with standard wires were unsuccessful. © 2005 Wiley‐Liss, Inc.
The Heat of Formation of the Uranyl Dication: Theoretical Evaluation Based on Relativistic Density Functional Calculations
Authors: Moskaleva Lyudmila V. , Matveev Alexei V. , Krüger Sven , Rösch Notker 
Published: December 2005

AbstractBy using a set of model reactions, we estimated the heat of formation of gaseous UO22+ from quantum‐chemical reaction enthalpies and experimental heats of formation of reference species. For this purpose, we performed relativistic density functional calculations for the molecules UO22+, UO2, UF6, and UF5. We used two gradient‐corrected exchange‐correlation functionals (revised Perdew–Burke–Ernzerhof (PBEN) and Becke–Perdew (BP)) and we accounted for spin‐orbit interaction in a self‐consistent fashion. Indeed, spin‐orbit interaction notably affects the energies of the model reactions, especially if compounds of UIV are involved. Our resulting theoretical estimates for Δf${H{{^{o}\hfill \atop 0\hfill}}}$(UO22+), 365±10 kcal mol−1 (PBEN) and 370±12 kcal mol−1 (BP), are in quantitative agreement with a recent experimental result, 364±15 kcal mol−1. Agreement between the results of the two different exchange‐correlation functionals PBEN and BP supports the reliability of our approach. The procedure applied offers a general means to derive unknown enthalpies of formation of actinide species based on the available well‐established data for other compounds of the element in question.
Ba2[Ni3N2]: A Low‐Valent Nitridonickelate—Synthesis, Crystal Structure, and Physical Properties
Authors: Mehta Akash , Höhn Peter , Schnelle Walter , Petzold Vivien , Rosner Helge , Burkhardt Ulrich , Kniep Rüdiger 
Published: December 2005

AbstractThe ternary alkaline‐earth nitridonickelate Ba2[Ni3N2] (Ba2[NiI2Ni0N2]) was prepared by the reaction of mixtures of Ba2N and Ni in nitrogen gas of ambient back‐pressure at 1173 K. The crystal structure determined by X‐ray single‐crystal and powder diffraction methods as well as from neutron diffraction data at various temperatures between 2 and 298 K is orthorhombic (Cmca (no. 64), 298 K: a=715.27(18) pm, b=1032.99(21) pm, c=740.12(20) pm) and provides the first example of a nitridonickelate with a two‐dimensional complex anion. The Ni(2) atom is described with a split position and the corresponding superstructure variants are investigated by theoretical full‐potential nonorthogonal local‐orbital calculations (FPLO). The average oxidation state of Ni in Ba2[Ni3N2] is +0.67, the lowest average value observed in nitridonickelates so far. Investigations of the physical properties demonstrate that Ba2[Ni3N2] acts as a “poor” metal with a large resistivity of ≈2.7 mΩ cm at 300 K and exhibits low‐dimensional magnetism with antiferromagnetic ordering at T≈90 K. XAS spectra correspond with low‐valent Ni states.
A Two‐State Computational Investigation of Methane CH and Ethane CC Oxidative Addition to [CpM(PH3)]n+ (M=Co, Rh, Ir; n=0, 1)
Authors: Petit Alban , Richard Philippe , Cacelli Ivo , Poli Rinaldo 
Published: December 2005

AbstractReductive elimination of methane from methyl hydride half‐sandwich phosphane complexes of the Group 9 metals has been investigated by DFT calculations on the model system [CpM(PH3)(CH3)(H)] (M=Co, Rh, Ir). For each metal, the unsaturated product has a triplet ground state; thus, spin crossover occurs during the reaction. All relevant stationary points on the two potential energy surfaces (PES) and the minimum energy crossing point (MECP) were optimized. Spin crossover occurs very near the σ‐CH4 complex local minimum for the Co system, whereas the heavier Rh and Ir systems remain in the singlet state until the CH4 molecule is almost completely expelled from the metal coordination sphere. No local σ‐CH4 minimum was found for the Ir system. The energetic profiles agree with the nonexistence of the CoIII methyl hydride complex and with the greater thermal stability of the Ir complex relative to the Rh complex. Reductive elimination of methane from the related oxidized complexes [CpM(PH3)(CH3)(H)]+ (M=Rh, Ir) proceeds entirely on the spin doublet PES, because the 15‐electron [CpM(PH3)]+ products have a doublet ground state. This process is thermodynamically favored by about 25 kcal mol−1 relative to the corresponding neutral system. It is essentially barrierless for the Rh system and has a relatively small barrier (ca. 7.5 kcal mol−1) for the Ir system. In both cases, the reaction involves a σ‐CH4 intermediate. Reductive elimination of ethane from [CpM(PH3)(CH3)2]+ (M=Rh, Ir) shows a similar thermodynamic profile, but is kinetically quite different from methane elimination from [CpM(PH3)(CH3)(H)]+: the reductive elimination barrier is much greater and does not involve a σ‐complex intermediate. The large difference in the calculated activation barriers (ca. 12.0 and ca. 30.5 kcal mol−1 for the Rh and Ir systems, respectively) agrees with the experimental observation, for related systems, of oxidatively induced ethane elimination when M=Rh, whereas the related Ir systems prefer to decompose by alternative pathways.
Total Synthesis of Gambierol: The Generation of the A–C and F–H Subunits by Using a C‐Glycoside Centered Strategy
Authors: Majumder Utpal , Cox Jason M. , Johnson Henry W. B. , Rainier Jon D. 
Published: December 2005

AbstractGambierol, a representative of the marine ladder toxin family, consists of eight ether rings, 18 stereocenters, and two challenging pyranyl rings having methyl groups that are in a 1,3‐diaxial orientation to one another. Herein we describe the generation of gambierol's A–C and F–H ring systems and demonstrate the versatility of the glycosyl anhydride, enol ether–olefin RCM strategy to fused polycyclic ethers. This work has both enabled us to generate sufficient quantities of the gambierol precursors and has enabled us to better understand the chemical transformations that were key to these efforts. Fundamental work included efforts to C‐glycosides and C‐ketosides, Claisen rearrangements, and enol ether–olefin RCM reactions.
Total Synthesis of Gambierol: Subunit Coupling and Completion
Authors: Johnson Henry W. B. , Majumder Utpal , Rainier Jon D. 
Published: December 2005

AbstractThe preceding manuscript detailed our synthesis of the gambierol A–C and F–H ring precursors. Reported herein is a description of the coupling of the two precursors and the conversion of the coupled material into gambierol. Coupling of the subunits involved ester formation, enol ether RCM, and mixed thioketal formation and reduction. By employing this strategy we were able to bring highly advanced subunits into the coupling and, as a result, we were able to minimize the number of post‐coupling transformations required to complete gambierol. At the completion of the synthesis, we generated 7.5 mg (1.5 % overall yield) of (−)‐gambierol in 44 steps (longest linear sequence).
Prostate‐specific antigen velocity and survival for patients with hormone‐refractory metastatic prostate carcinoma
Authors: Rozhansky Flora , Chen Ming‐Hui , Cox Michael C. , Dahut William , Figg William D. , D'Amico Anthony V. 
Published: December 2005

AbstractBACKGROUNDThe authors investigated whether prostate‐specific antigen (PSA) velocity was associated significantly with the time to death after randomization among patients with hormone‐refractory metastatic prostate carcinoma (HRMPC) who were treated with cytotoxic, cytotatic, or combination therapy.METHODSThe study cohort included 213 men with HRMPC who were treated on 3 prospective, randomized Phase II studies between February 1996 and October 2001. Cox regression analysis was used to evaluate whether there was a significant association between PSA velocity and the time to death after randomization, controlling for treatment and known prognostic factors.RESULTSIncreasing PSA velocity was associated significantly with shorter survival after randomization (P = 0.005) controlling for treatment and known prognostic factors. The adjusted hazard ratio for death was 1.8 (95% confidence interval [95% CI], 1.3–2.5; P = 0.0004) for men who had a PSA velocity > 0.0 ng/mL per month compared with men who had a PSA velocity ≤ 0.0 ng/mL per month. Estimates of survival 2 years after randomization for these men were 16% (95% CI, 7–25%) and 44% (95% CI, 35–53%), respectively.CONCLUSIONSPSA velocity was associated significantly with the length of survival among men with HRMPC who received cytotoxic, cytostatic, or combination therapy. Cancer 2006. © 2005 American Cancer Society.
Oxidation of Formic Acid and Carbon Monoxide on Gold Electrodes Studied by Surface‐Enhanced Raman Spectroscopy and DFT
Authors: Beltramo Guillermo L. , Shubina Tatyana E. , Koper Marc T. M. 
Published: December 2005

AbstractThe oxidation of formic acid and carbon monoxide was studied at a gold electrode by a combination of electrochemistry, in situ surface‐enhanced Raman spectroscopy (SERS), differential electrochemical mass spectrometry, and first‐principles DFT calculations. Comparison of the SERS results and the (field‐dependent) DFT calculations strongly suggests that the relevant surface‐bonded intermediate during oxidation of formic acid on gold is formate HCOO${{{- \hfill \atop ad\hfill}}}$. Formate reacts to form carbon dioxide via two pathways: at low potentials, with a nearby water to produce carbon dioxide and a hydronium ion; at higher potentials, with surface‐bonded hydroxyl (or oxide) to give carbon dioxide and water. In the former pathway, the rate‐determining step is probably related to the reaction of surface‐bonded formate with water, as measurements of the reaction order imply a surface almost completely saturated with adsorbate. The potential dependence of the rate of the low‐potential pathway is presumably governed by the potential dependence of formate coverage. There is no evidence for CO formation on gold during oxidation of formic acid. The oxidation of carbon monoxide must involve the carboxyhydroxyl intermediate, but SERS measurements do not reveal this intermediate during CO oxidation, most likely because of its low surface coverage, as it is formed after the rate‐determining step. Based on inconclusive spectroscopic evidence for the formation of surface‐bonded OH at potentials substantially below the surface oxidation region, the question whether surface‐bonded carbon monoxide reacts with surface hydroxyl or with water to form carboxyhydroxyl and carbon dioxide remains open. The SERS measurements show the existence of both atop and bridge‐bonded CO on gold from two distinguishable low‐frequency modes that agree very well with DFT calculations.
Current Densities and Nucleus‐Independent Chemical Shift Maps from Reciprocal‐Space Density Functional Perturbation Theory Calculations
Authors: Sebastiani Daniel 
Published: December 2005

AbstractA method to calculate condensed‐matter nucleus independent chemical shift maps (NICS maps) from first principles in the framework of density functional theory is presented. I use a pseudopotential plane‐wave approach in which the electronic current density and the NICS map are obtained from an inverse Fourier transformation of the induced magnetic field represented in reciprocal space (G space). Due to its intrinsically periodic description, the method is suitable for isolated molecules (by using a supercell technique) and for condensed‐phase systems like solids. The periodic NICS method was applied to hydrogen‐bonded calixhydroquinone nanotubes, crystalline graphite, and two carbon nanotube systems.