bluuebunny/crossref_metadata_2025 huggingface dataset:
Group Sequential Methods in Biomedical Research
Authors: Liu Aiyi , Liu Chunling , Yu Kai F.
Published: March 2010

Group sequential methods have become a common practice in biomedical research due to various reasons such as ethical, administrative, and economic concerns. In testing statistical hypotheses a group sequential procedure allows the hypotheses to be tested repeatedly at several time points after a group of observations have been completed.

The sequential methods pose great challenges to statisticians. These challenges include not only finding appropriate methods of determining critical values at each interim test to control error rates such as false positive/negative rate, but also developing efficient inferential procedures for secondary analysis such as estimation, confidence intervals,p‐values and secondary endpoints. This is because the data‐based random stopping of the sampling process introduces bias to conventional procedures that are appropriate in a non‐sequential (fixed‐size) setting.

In the context of Brownian motion as approximation to various test statistics, this article presents an overview of several common group sequential testing procedures, and methods for computing point estimation, confidence intervals, andp‐values.
Statistical Modeling of Human Fecundity
Authors: Sundaram Rajeshwari , Buck Louis Germaine M. , Kim Sungduk
Published: March 2010

Human fecundity is of great interest to reproductive scientists, as well as to couples trying to conceive. It is measured by the probability of pregnancy in a menstrual cycle for a sexually active couple who is not contracepting. Reproductive epidemiologists are interested in models for human fecundity to identify the determinants and to identify preventable causes of reproductive dysfunction. There is also suspicion that various environmental factors negatively affect the human fertility. Motivated by these issues, there has been considerable interest in developing biologically precise statistical models for human fecundity. This chapter begins with a brief discussion of various biological and behavioral factors that potentially impact pregnancy. Furthermore, emphasis is made on various biological and behavioral factors that impact pregnancy but are not measurable. Next, we review various statistical models for pregnancy that are available in literature, with emphasis on models that are biologically relevant. We also indicate some outstanding issues that need to be addressed to build stronger statistical models that are biologically valid. We conclude with an analysis of the New York Anglers Cohort Prospective Pregnancy study.
Panel Count Data
Authors: Sun Jianguo
Published: March 2010

Panel count data usually refer to data arising from studies on recurrent events in which study subjects are followed or observed only periodically rather than continuously. In these situations, the objective of interest is about the occurrence of some events that can occur multiple times or repeatedly and the studies resulting in this type of information are often referred to as event history studies. There are many fields that produce panel count data and they include medical studies, reliability experiments and social science. This article will review some basic concepts about panel count data, some common issues and questions of interest in their analysis as well as the corresponding statistical procedures that are available. In particular, we will discuss estimation of the mean function of the underlying counting process characterizing the occurrence of the events, comparison of several processes and regression analysis of panel count data. Some discussion will also be provided for situations that involve dependent or informative observation processes.
Centralized Genomic Control: A Simple Approach Correcting for Population Structures
Authors: Zhang Hong , Li Qizhai , Zang Yong , Yang Yaning , Zheng Gang
Published: March 2010

The case‐control study is a useful design for testing for genetic association. However, it may yield spurious associations due to population structure. Population stratification (PS) and cryptic relatedness (CR) are two common population structures under which the trend test for association may be biased and its variance may be distorted. Genomic control and delta centralization are two simple approaches to correct for the variance distortion and the bias, respectively, using unlinked null genetic markers. An alternative simple method, centralized genomic control (CGC), that corrects for both bias and variance distortions simultaneously using unlinked null markers is studied. It can also handle studies with a small number of subjects and a small number of null markers. This approach requires the allele frequencies of the markers of interest roughly to match those of unlinked null markers in control samples. This matching and the effectiveness of various approaches under the matching are investigated by simulation studies. Applications to two real datasets (a candidate gene study and a genome‐wide association study) illustrate that the CGC outperforms the existing methods which correct for either the variance distortion or the bias due to PS or CR.
Effect of Grain Size Reduction and Geometrical Confinement in Fine Grained Copper: Potential Applications as a Material for Reversible Electrical Contacts
Authors: Champion Yannick , Bréchet Yves
Published: March 2010

The potential of ultrafine grained copper as a material for reversible electrical contact is investigated. The influence of grain size and sample size on strength and electrical properties is discussed. The existence of an optimal grain size and the relevance of size effects for the mechanical properties are analyzed.
Molecular Engineering of Blue Fluorescent Molecules Based on Silicon End‐Capped Diphenylaminofluorene Derivatives for Efficient Organic Light‐Emitting Materials
Authors: Lee Kum Hee , Kang Lee Kyung , Lee Jin Yong , Kang Sunwoo , Jeon Soon Ok , Yook Kyoung Soo , Lee Jun Yeob , Yoon Seung Soo
Published: March 2010

Blue fluorescent materials based on silicone end‐capped 2‐diphenylaminofluorene derivatives are synthesized and characterized. These materials are doped into a 2‐methyl‐9,10‐di‐[2‐naphthyl]anthracene host as blue dopant materials in the emitting layer of organic light‐emitting diode devices bearing a structure of ITO/DNTPD (60 nm)/NPB (30 nm)/emitting layer (30 nm)/Alq3 (20 nm)/LiF (1.0 nm)/Al (200 nm). All devices exhibit highly efficient blue electroluminescence with high external quantum efficiencies (3.47%–7.34% at 20 mA cm−2). The best luminous efficiency of 11.2 cd A−1 and highest quantum efficiency of 7.34% at 20 mA cm−2 are obtained in a device with CIE coordinates (0.15, 0.25). A deep‐blue OLED with CIE coordinates (0.15, 0.14) exhibits a luminous efficiency of 3.70 cd A−1 and quantum efficiency of 3.47% at 20 mA cm−2.
The Critical Role of the Underlayer Material and Thickness in Growing Vertically Aligned Carbon Nanotubes and Nanofibers on Metallic Substrates by Chemical Vapor Deposition
Authors: Nessim Gilbert D. , Acquaviva Donatello , Seita Matteo , O'Brien Kevin P. , Thompson Carl V.
Published: March 2010

Vertically aligned carbon nanotubes and nanofibers are grown on metallic Ta and Pd underlayers at temperatures below 500 °C. Controlling the size of the grains of the underlayer film is critical because this leads to a more uniform distribution of catalyst dots, which in turn results in vertical alignment of the carbon nanostructures. Rapid and limited heating and appropriate materials selection can also be used to limit catalyst/underlayer reactions that hinder or suppress carbon nanostructure growth or that lead to entangled growth. Control of catalyst reactivity with metallic underlayers is significant because growth on conductive substrates is notoriously difficult, but needed for many applications such as the use of carbon nanostructures in microelectronic circuits.
Model‐based optimization of hydrogen generation by methane steam reforming in autothermal packed‐bed membrane reformer
Authors: Simakov David S. A. , Sheintuch Moshe
Published: March 2010

An autothermal membrane reformer comprising two separated compartments, a methane oxidation catalytic bed and a methane steam reforming bed, which hosts hydrogen separation membranes, is optimized for hydrogen production by steam reforming of methane to power a polymer electrolyte membrane fuel cell (PEMFC) stack. Capitalizing on recent experimental demonstrations of hydrogen production in such a reactor, we develop here an appropriate model, validate it with experimental data and then use it for the hydrogen generation optimization in terms of the reformer efficiency and power output. The optimized reformer, with adequate hydrogen separation area, optimized exothermic‐to‐endothermic feed ratio and reduced heat losses, is shown to be capable to fuel kW‐range PEMFC stacks, with a methane‐to‐hydrogen conversion efficiency of up to 0.8. This is expected to provide an overall methane‐to‐electric power efficiency of a combined reformer‐fuel cell unit of ∼0.5. Recycling of steam reforming effluent to the oxidation bed for combustion of unreacted and unseparated compounds is expected to provide an additional efficiency gain. © 2010 American Institute of Chemical Engineers AIChE J, 2011
Intra‐individual variability in genetic and environmental models of attention‐deficit/hyperactivity disorder
Authors: Perry G.M.L. , Sagvolden T. , Faraone S.V.
Published: March 2010

The frequent observation of intra‐individual variability (IIV) in the expression of ADHD symptoms suggest that IIV is an integral component of the disorder. We tested IIV in ADHD‐like phenotype from five different studies of rodent models of ADHD, including studies with Spontaneous Hypertensive Rats (SHR/NCrl and SHR/N), Wistar‐Kyoto Hyperactive Rats (WKHA/N), Wistar‐Kyoto Hypertensive rat (WKHT), PCB‐126 and ‐153‐treated Lewis rats and behaviorally normal Wistar/Mol, Wistar‐Kyoto (WKY/N and WKY/NMol), and untreated Lewis rats. Averages of the absolute residual deviation of ADHD‐like behavior from individual means (“individual phenotypic dispersion,” PDi) were used to represent IIV in the fixed‐interval (FI) and extinction (EXT) phases of operant behavioral activity. Across all studies, SHR rats had higher PDi than WKY rats (P < 0.0001) for all ADHD‐like traits, and higher PDi for hyperactivity than WKHT and WKHA/N rats. Male SHR rats in particular had higher PDi for hyperactivity than male or female WKYs, SHR females for EXT hyperactivity, and higher dispersion for inattention than WKY females. These findings strongly suggest the genetic control of IIV, and suggest that the SHR may be a useful model for the identification of genes for IIV in human ADHD. These findings also obliquely support the SHR as a useful model for ADHD overall. © 2010 Wiley‐Liss, Inc.
No association of the serotonin transporter polymorphisms 5‐HTTLPR and RS25531 with schizophrenia or neurocognition
Authors: Konneker Thomas I. , Crowley James J. , Quackenbush Corey R. , Keefe Richard S.E. , Perkins Diana O. , Stroup T. Scott , Lieberman Jeffrey A. , van den Oord Edwin , Sullivan Patrick F.
Published: March 2010

A promoter polymorphism in the serotonin transporter gene has been widely studied in neuropsychiatry. We genotyped the 5‐HTTLPR/rs25531 triallelic polymorphism in 728 schizophrenia cases from the CATIE study and 724 control subjects. In a logistic regression with case/control status as dependent variable and 7 ancestry‐informative principal components as covariates, the effect of 5‐HTTLPR/rs25531 composite genotype was not significant (odds ratio = 1.008, 95% CI 0.868–1.172, P = 0.91). In cases only, 5‐HTTLPR/rs25531 was not associated with neurocognition (summary neurocognitive index P = 0.21, working memory P = 0.32) or symptomatology (PANSS positive P = 0.67 and negative symptoms P = 0.46). We were unable to identify association of the triallelic 5‐HTTLPR with schizophrenia, neurocognition, or core psychotic symptoms even at levels of significance unadjusted for multiple comparisons. © 2010 Wiley‐Liss, Inc.
Neutral and Oxidized Triisopropylsilyl End‐Capped Oligothienoacenes: A Combined Electrochemical, Spectroscopic, and Theoretical Study
Authors: Aragó Juan , Viruela Pedro M. , Ortí Enrique , Malavé Osuna Reyes , Vercelli Barbara , Zotti Gianni , Hernández Víctor , López Navarrete Juan T. , Henssler John T. , Matzger Adam J. , Suzuki Yoshitake , Yamaguchi Shigehiro
Published: March 2010

This work presents an analysis of the structural, electrochemical, and optical properties of a family of triisopropylsilyl end‐capped oligothienoacenes (TIPS‐Tn‐TIPS, n=4–8) by combining cyclic voltammetry, spectroscopic techniques, and quantum‐chemical calculations. TIPS‐Tn‐TIPS compounds form stable radical cations, and dications are only obtained for the longest oligomers (n=7 and 8). Oxidation leads to the quinoidization of the conjugated backbone, from which electrons are mainly extracted. The absorption and fluorescence spectra show partially resolved vibronic structures even at room temperature, due to the rigid molecular geometry. Two well‐resolved vibronic progressions are observed at low temperatures due to the vibronic coupling, with normal modes showing wavenumbers of ≈1525 and ≈480 cm−1. Optical absorption bands display remarkable bathochromic dispersion with the oligomer length, indicative of the extent of π conjugation. The optical properties of the oxidized compounds are characterized by in situ UV/Vis/NIR spectroelectrochemistry. The radical cation species show two intense absorption bands emerging at energies lower than in the neutral compounds. The formation of the dication is only detected for the heptamer and the octamer, and shows a new band at intermediate energies. Optical data are interpreted with the help of density functional theory calculations performed at the B3LYP/6‐31G** level, both for the neutral and the oxidized compounds.
Competitive Adsorption of Methylene Blue and Rhodamine B on Natural Zeolite: Thermodynamic and Kinetic Studies
Authors: Jafari‐zare Farhade , Habibi‐yangjeh Aziz
Published: March 2010

A batch system was applied to study the adsorption behavior of methylene blue (MB) and rhodamine B (RB) in single and binary component systems on natural zeolite. In the single component systems, the zeolite presents higher adsorption capacity for MB than RB with the maximal adsorption capacity of 7.95×10−5 and 1.26×10−5 mol/g at 55°C for MB and RB, respectively. Kinetic studies indicated that the adsorption followed pseudo‐second‐ order kinetics and could be described by a two‐step diffusion process. For the single component systems, the adsorption isotherm could be fitted by the Langmuir model. In the binary component system, MB and RB exhibit competitive adsorption on the zeolite. The adsorption is approximately reduced to 50% and 60% of single component adsorption systems of MB and RB, respectively at an initial concentration of 6×10−6 mol·L−1 at 25°C. In the binary component system, kinetic and adsorption isotherm studies demonstrate that the experimental data are following pseudo‐second‐order kinetics and Langmuir isotherm and kinetic data are fairly described by a two‐step diffusion model. Effect of solution pH on adsorption of MB and RB in both single and binary component systems was studied and the results were described by electrostatic interactions.
Differential Kinetic Spectrophotometric Determination of Methamidophos and Fenitrothion in Water and Food Samples by Use of Chemometrics
Authors: Deng Na , Ni Yongnian , Kokot Serge
Published: March 2010

A spectrophotometric method for simultaneous analysis of methamidophos and fenitrothion was proposed by application of chemometrics to the spectral kinetic data, which was based upon the difference in the inhibitory effect of the two pesticides on acetylcholinesterase (AChE) and the use of 5,5′‐dithiobis(2‐nitrobenzoic acid) (DTNB) as a chromogenic reagent for the thiocholine iodide (TChI) released from the acetylthiocholine iodide (ATChI) substrate. The absorbance of the chromogenic product was measured at 412 nm. The different experimental conditions affecting the development and stability of the chromogenic product were carefully studied and optimized. Linear calibration graphs were obtained in the concentration range of 0.5–7.5 ng·mL−1 and 5–75 ng·mL−1 for methamidophos and fenitrothion, respectively. Synthetic mixtures of the two pesticides were analysed, and the data obtained processed by chemometrics, such as partial least square (PLS), principal component regression (PCR), back propagation‐artificial neural network (BP‐ANN), radial basis function‐artificial neural network (RBF‐ANN) and principal component‐radial basis function‐artificial neural network (PC‐RBF‐ANN). The results show that the RBF‐ANN gives the lowest prediction errors of the five chemometric methods. Following the validation of the proposed method, it was applied to the determination of the pesticides in several commercial fruit and vegetable samples; and the standard addition method yielded satisfactory recoveries.
Synthesis of Novel Trispiroheterocycles through 1,3‐Dipolar Cycloaddition of Azomethine Ylides and Nitrile Oxide
Authors: Li Xiaofang , Yu Xianyong , Yi Pinggui
Published: March 2010

The 1,3‐dipolar cycloaddition of an azomethine ylide generated by a decarboxylative route from sarcosine and isatin to 1‐benzyl‐3,5‐diarylmethylidene‐piperidin‐4‐ones afforded novel di‐spiro‐indolo/pyrrolidino/piperidines in moderate yields. Further cycloaddition of these di‐spiro compounds to nitrile oxide afforded tri‐spiro‐indolo/pyrrolidino/piperadino/isoxazolines in moderate yields with high regio‐ and stereoselectivity.
Bimetallic Rare Earth Alkyl Complexes Bearing Bridged Amidinate Ligands: Synthesis and Activity for L‐Lactide Polymerization
Authors: Yang Jianping , Xu Ping , Luo Yunjie
Published: March 2010

Four novel bridged‐amidines H2L {1,4‐R1[C(=NR2)(NHR2)]2 [R1=C6H4, R2=2,6‐iPr2C6H3 (H2L1); R1=C6H4, R2=2,6‐Me2C6H3 (H2L2); R1=C6H10, R2=2,6‐iPr2C6H3 (H2L3); R1=C6H10, R2=2,6‐Me2C6H3 (H2L4)]} were synthesized in 65%–78% isolated yields by the condensation reaction of dicarboxylic acid with four equimolar amounts of amines in the presence of PPSE at 180°C. Alkane elimination reaction of Ln(CH2SiMe3)3(THF)2 (Ln=Y, Lu) with 0.5 equiv. of amidine in THF at room temperature afforded the corresponding bimetallic rare earth alkyl complexes (THF)(Me3SiCH2)2LnL1Ln(CH2SiMe3)2(THF) [Ln=Y (1), Lu (2)], (THF)(Me3SiCH2)2LnL2Ln‐ (CH2SiMe3)2(THF) [Ln=Y (3), Lu (4)], (THF)(Me3SiCH2)2YL3Y(CH2SiMe3)2(THF) (5), (THF)(Me3SiCH2)2YL4‐ Y(CH2SiMe3)2(THF) (6) in 72% –80% isolated yields. These neutral complexes showed activity towards L‐lactide polymerization in toluene at 70°C to give high molecular weight (M>104) and narrow molecular weight distribution (Mw/Mn≦1.40) polymers
Synthesis, Spectral and Thermal Analyses of Novel Bi‐ and Polyhomonuclear Complexes of Pyrimidine Bisazo‐dianil Derivatives
Authors: El‐Wakiel Nadia , Khedr Abdalla , Mansour Ramadan
Published: March 2010

Seven new bi‐ and polyhomonuclear transition metal complexes with three polyhydroxlated bisazodianil ligands were synthesized and characterized. The ligands were derived from condensation of 6‐(5‐formyl‐2‐hydroxyphenylazo)‐2,4‐dihydroxypyrimidine with aliphatic diamines (H8L1, H8L2 and H6L3). The data of elemental and thermal analyses, molar conductance measurement, IR, electronic and ESR spectra as well as magnetic moment measurements support the formation of [L1Co7Cl6(H2O)10]·22H2O (1), [H2L2Mn6Cl6(H2O)8]·3H2O·2EtOH (3), [L2Co8Cl8(H2O)12]·24H2O (4), [H4L3Co2Cl2(H2O)2]·8H2O·2EtOH (6) with a tetrahedral geometry and [H2L1Ni5Cl4(H2O)16]·19H2O·EtOH (2), [L2Ni8Cl8(H2O)28]·8H2O·EtOH (5) with an octahedral geometry while [H6L3Cu3(H2O)7]Cl3·10H2O (7) has a distorted tetrahedral arrangement. The mode of bonding between the metal ions and the ligand molecules is determined and the metal‐metal interaction was studied. The activation thermo‐kinetic parameters for the thermal decomposition steps of the complexes E*, ΔH*, ΔS*, and ΔG* were calculated.
FeCl3: Highly Efficient Catalyst for Synthesis of α‐Amino Nitriles
Authors: Heravi Majid M. , Ebrahimzadeh Mojgan , Oskooie Hossein A. , Baghernejad Bita
Published: March 2010

α‐Amino nitriles are synthesized by the three‐component coupling reaction of aldehydes, amines and trimethylsilyl cyanide using FeCl3 as a solid acid catalyst, under solvent‐free conditions in good yields. The catalyst was recovered by simple filtration and was recycled in subsequent reactions.
Increased Restenosis Rates 12 Months After Coronary Implantation of the Sirolimus‐Eluting YUKON‐Choice Stent Compared to the Paclitaxel‐Eluting TAXUS Stent
Authors: Ruef Johannes , Störger Hans , Schwarz Franz , Haase Jürgen
Published: March 2010

Background

Previously the polymer‐free sirolimus‐eluting YUKON‐Choice stent (A) has demonstrated noninferiority compared to the polymer‐based paclitaxel‐eluting TAXUS stent (B). To test for long‐term equivalency in unselected real‐world coronary lesions of various complexities, we retrospectively compared both stents.

Methods

A total of 410 patients with symptomatic coronary artery disease (CAD) were treated with stent A (n = 205) or stent B (n = 205). Baseline clinical characteristics, lesion location, and length and the number of stents implanted per lesion were equally distributed. Clinical follow‐up with assessment of major adverse cardiac events (MACE) and noncardiac deaths was obtained at 9 and 12 months.

Results

Nominal stent diameter and nominal length of the stented segment were without differences between the groups. The incidence of MACE after 12 months was significantly higher in group A (35.1%) compared to group B (16.6%, P = .001). This was mainly due to increased rates of target‐lesion revascularizations in group A (13.7%) vs group B (4.4%, P = .005). No significant differences in target‐vessel revascularizations and non‐target‐vessel revascularizations were observed. In group B, 1 stent thrombosis was documented (0.5%) vs none in group A (P > .05); in each group 1 myocardial infarction (MI), but no cardiac deaths occurred; 3 noncardiac deaths in group A (1.5%) vs 7 in group B (3.4%) were observed (P = .3).

Conclusions

In contrast to our previous findings indicating no differences in MACE between patients treated with the polymer‐free sirolimus‐eluting YUKON‐Choice stent and the polymer‐based paclitaxel‐eluting TAXUS stent at 6 months, we herewith show that 12 months after percutaneous coronary intervention (PCI) of real‐world coronary lesions the YUKON stent appears to be inferior due to increased target‐lesion revascularization (TLR) rates as a consequence of delayed restenosis. Copyright © 2010 Wiley Periodicals, Inc.
Clinical Features of the Dilated Phase of Hypertrophic Cardiomyopathy in Comparison With Those of Dilated Cardiomyopathy
Authors: Hamada Tomoyuki , Kubo Toru , Kitaoka Hiroaki , Hirota Takayoshi , Hoshikawa Eri , Hayato Kayo , Shimizu Yuji , Okawa Makoto , Yamasaki Naohito , Matsumura Yoshihisa , Yabe Toshikazu , Takata Jun , Doi Yoshinori L.
Published: March 2010

Background

Although the dilated phase of hypertrophic cardiomyopathy (D‐HCM) characterized by left ventricular (LV) systolic dysfunction and cavity dilatation has been reported to be a poor prognosis, this is now in contrast to the improved prognosis of dilated cardiomyopathy (DCM) in the era of advancements in heart failure management. There has been no investigation of the clinical features of D‐HCM compared with those of DCM from the point of management of systolic dysfunction.

Hypothesis

The aim of this study was to investigate the clinical features of D‐HCM in comparison with those of DCM in a single institute.

Methods

We studied 20 consecutive patients with D‐HCM (global ejection fraction < 50%) and 115 consecutive patients with DCM.

Results

At diagnosis of D‐HCM, 8 (40%) of the D‐HCM patients already experienced dyspnea (New York Heart Association [NYHA] class ≥ III). Left atrial diameter was larger and prevalence of atrial fibrillation was higher in the D‐HCM group, although LV size was larger and LV ejection fraction was lower in the DCM group. During the follow‐up period (4.0 years), 11 (55%) of the patients with D‐HCM died. The 5‐year survival rate from all‐cause mortality including cardiac transplantation was 45.6% in patients with D‐HCM vs 81.6% in patients with DCM (log‐rank P = .0001).

Conclusions

Patients with D‐HCM were more symptomatic at diagnosis, although LV dilatation and impaired fractional shortening seemed more severe in patients with DCM. The prognosis for D‐HCM patients was worse than that for patients with DCM despite similar or even more intensive treatment for heart failure. Copyright © 2010 Wiley Periodicals, Inc.
Arm disability in patients on hemodialysis
Authors: Toffola Elena Dalla , Petrucci Lucia , Mazzacane Bruno , Klersy Catherine , Villa Giuseppe , Bossi Daniela , Bejor Maurizio
Published: March 2010

INTRODUCTION

End‐stage renal disease patients on hemodialysis (HD) often present osteoarticular and musculoskeletal complications related both to chronic renal disease as well as to chronic dialysis. The aim of the present study was to assess the degree of upper‐limb disability, and its determinants, in a group of patients on chronic HD to determine functional capacity and the need for rehabilitative treatment.

MATERIALS AND METHODS

We studied 97 HD patients (46 male, 51 female) with a mean age of 64.4 years, and 51 healthy controls. The Disabilities of the Arm, Shoulder, and Hand (DASH) Outcome Measure was used to clinically assess degree of disability as well as finger function and movement.

RESULTS

For study purposes, patients were divided into 3 groups according to the duration of dialysis: <5 years, 5–10 years, and >10 years. The median DASH score was 9.5 (interquartile range [IQR]: 3.4–24.1) in the entire population. However, it differed significantly in the 3 dialysis groups with scores of 5.2 (IQR: 2.6–18.1), 14.7 (3.4–23.7), and 37.5 (9.5–73.3) in the <5 year, 5–10 year, and >10 year groups, respectively (p < .001). Additionally, disability correlated with shoulder and hand pain and with finger stiffness. Moreover, patients on dialysis for more than 10 years were affected by pain involving several upper limb joints. All patients who worked had a DASH score lower than 20. The median DASH score was 2.6 (IQR: 0.9–5.2) in the control group.

CONCLUSION

Duration of dialysis is associated with progressive disability. Thus, early rehabilitation programs are recommended in patients who are expected to undergo long‐term dialysis.
A more cost effective and rapid high percentage germ‐line transmitting chimeric mouse generation procedure via microinjection of 2‐cell, 4‐cell, and 8‐cell embryos with ES and iPS cells
Authors: Kraus Petra , Leong Geraldine , Tan Valerie , Xing Xing , Goh Jie Wei , Yap Sook Peng , Lufkin Thomas
Published: March 2010

The long‐standing traditional method of delivering embryonic stem (ES) cells adjacent to the inner cell mass (ICM) of blastocysts to generate chimeras improved with the advent of laser‐ or Piezo assisted 8‐cell embryo microinjection. Building on this technology but omitting either the laser or the Piezo to penetrate the zona pellucida and making use of earlier embryonic stages (2‐cell and 4‐cell), we were able to significantly speed up and economize our ES cell microinjection and chimera production throughput. We demonstrate here that embryonic (ES) and induced pluripotent stem (iPS) cells can stay fully pluripotent when delivered into 2‐cell‐ and 4‐cell‐stage embryos, long before they would naturally be incorporated into the ICM of a blastocyst (E3.5) and give rise to high percentage and germline transmitting chimeras. genesis 48:394–399, 2010. © 2010 Wiley‐Liss, Inc.
Synthesis, Crystal Structures, and Magnetic Properties of MnII, CoII, and ZnII Coordination Polymers Containing 1,2,4,5‐Benzenetetracarboxylic Acid and 4,4′‐Azobispyridine
Authors: Zhao Li‐Min , Li Huan‐Huan , Wu Ying , Zhang Shi‐Yuan , Zhang Zhen‐Jie , Shi Wei , Cheng Peng , Liao Dai‐Zheng , Yan Shi‐Ping
Published: March 2010

Manganese(II), cobalt(II), and zinc(II) coordination polymers, {[Mn(H2btec)(azopy)(H2O)2]·(azopy)}n (1), {[Co(H2btec)(azopy)(H2O)2]·(azopy)}n (2), and {[Zn2.5(btec)(azopy)(μ3‐OH)(H2O)]·H2O}n (3) (H4btec = 1,2,4,5‐benzenetetracarboxylic acid; azopy = 4,4′‐azobispyridine), were synthesized by ahydrothermal method and characterized by single‐crystal X‐ray diffraction, elemental analysis, and powder X‐ray diffraction. Compounds 1 and 2 are isomorphic and crystallize in the triclinic space group P$\bar {1}$, exhibiting a 2D grid framework bridged by two types of ligands. Compound 3 also crystallizes in the triclinic space group P$\bar {1}$ and possess an interesting 3D coordination framework with an unprecedented dodecadentate coordination mode and a unique {416.510.618.7}{44.5.6}2 topological structure. The ideal topology of 3 has not been encountered in metal–organic framework chemistry, which has been deposited in the Reticular Chemistry Structure Resource under the name zim net. Magnetic studies show that there are antiferromagnetic interactions in both 1 and 2. The cyclic voltammograms of 1–3 in the solid state were also obtained.
Dicarba‐closo‐dodecaboranes with One and Two Ethynyl Groups Bonded to Boron
Authors: Himmelspach Alexander , Finze Maik
Published: March 2010

The diethynyldicarba‐closo‐dodecaboranes 1,2‐R2‐9,12‐(HCC)2‐closo‐1,2‐C2B10H8 [R = H (1a), Me (2a)] and 9,10‐(HCC)2‐closo‐1,7‐C2B10H10 (3a) were obtained by Pd‐catalyzed Kumada‐type cross‐coupling reactions of the corresponding diiodinated dicarba‐closo‐dodecaboranes withMe3SiCCMgBr followed by desilylation of the trimethylsilylalkynyl‐substituted clusters. In addition, the related {closo‐C2B10} derivatives with one ethynyl group 1,2‐R‐9‐HCC‐closo‐1,2‐C2B10H9 [R = H (4a), Me (5a)], 9‐HCC‐closo‐1,7‐C2B10H11 (6a), and 2‐HCC‐closo‐1,12‐C2B10H11 (7a) were synthesized and their spectroscopic properties were compared to those of the diethynyl‐substituted {closo‐C2B10} clusters. The ethynyl‐ and trimethylsilylalkynyl‐functionalized dicarba‐closo‐dodecaboranes were characterized by elemental analysis, mass spectrometry, as well as by multinuclear NMR, IR, and Raman spectroscopy. The assignment of the NMR spectroscopic chemical shifts and the IR and Raman bands is supported by theoretical values derived from density functional calculations. The crystal structures of 9,12‐(HCC)2‐closo‐1,2‐C2B10H10 (1a), 9,10‐(HCC)2‐closo‐1,7‐C2B10H10 (3a), and 1,2‐Me‐9,12‐(Me3SiCC)2‐closo‐1,2‐C2B10H8 (2b) were determined by single‐crystal X‐ray diffraction. Selected experimental bond properties are compared to bond lengths and angles calculated at the B3LYP/6‐311++G(d,p) level of theory.
A Structural Investigation of Trivalent and Divalent Rare Earth Thiocyanate Complexes Synthesised by Redox Transmetallation
Authors: Bakker Jacinta M. , Deacon Glen B. , Forsyth Craig M. , Junk Peter C. , Wiecko Michal
Published: March 2010

A wide range of reactive trivalent and divalent rare earth thiocyanate complexes with 1,2‐dimethoxyethane (dme), tetrahydrofuran (thf) and acetonitrile namely [RE(NCS)3(dme)3] [RE = La (1a), Nd (1b)], [RE(NCS)3(dme)2(μ‐dme)0.5]2 [RE = Dy (1d), Er (1e)], [RE(NCS)3(thf)4]2 [RE = Y (3a), La (3b), Nd (3c), Sm (3d), Dy (3e), Ho (3f)], [Ca(NCS)2(dme)3] [rac‐(4a)], [RE(NCS)2(dme)3] (RE = Sm (rac‐4b), Eu (rac‐4c), [Ca(Yb)(NCS)2(NCMe)5]·NCMe [Ca (6a), Yb (6b)], and [Eu(NCS)2(thf)4]2 (7) have been prepared in good to high yield by redox transmetallation between rare earth metals and the commercially available Hg(SCN)2. In addition [Eu(NCS)3(dme)2(μ‐dme)0.5]2 (1c) and [Yb(NCS)3(dme)2] (1f) have been prepared by oxidation of rac‐4c and [Yb(NCS)2(thf)2], respectively, with Hg(SCN)2 in dme. Crystallisation of 1e from dme/diglyme (diglyme = bis(2‐methoxyethyl) ether) and thf yields [Er(NCS)3(diglyme)(dme)] (2) and [Er(NCS)3(thf)4]2 (3g), respectively, and prolonged storage of rac‐4a in cold dme gave [Ca(NCS)2(dme)2(H2O)] (5). All undergo rapid hydrolysis on exposure to air. Two structural breaks are observed for [RE(NCS)3(dme)n] complexes, all of which have solely RE–NCS binding. Compounds 1a,b are nine‐coordinate monomers that differ in the arrangement (T or Y) of the RE(NCS)3 moiety, 1c–e are eight coordinate dinuclear complexes being bridged by a single η1:η1‐(O,O′)‐dme and 1f is a seven coordinate monomer. 2 is an eight coordinate monomer with, unusually for the present complexes, a facial RE(NCS)3 array. By contrast 3a–g are all dimeric, eight coordinate complexes with two unusual RE–NCS–RE bridges. The RE–S bonds are very weak and show little variation with RE3+ radius, and Er–S of 3g increases by 0.18 Å between 123 K and room temperature), foreshadowing a change to a seven coordinate monomer with [Yb(NCS)3(thf)4]. Monomeric eight coordination with transoid (N–RE–N ≈ 149°) SCN–RE–NCS bonding is observed in rac‐4a–c and Λ‐4c, whilst 5 is a seven‐coordinate monomer with a cis‐Ca(NCS)2 array. Single crystals of 6,a,b contain seven‐coordinate, pentagonal bipyramidal monomers with trans‐NCS ligands, whereas 7 is dimeric with two Eu–NCS–Eu bridging ligands and seven coordination for Eu.
Peak parking determination of the obstruction factor in lauryl acrylate monolithic CEC columns
Authors: Anderson Gwendolyn J. , LaPier Zoe , Cammarata Michael B. , Cullum Tae Sun , Bushey Michelle M.
Published: March 2010

The peak parking method was used to determine the obstruction factor of lauryl acrylate porous polymer monoliths. Polymers were prepared in situ in fused‐silica capillaries using thermally initiated polymerization. These columns have been used for CEC of neutral analytes. Thiourea, which is unretained, was used as the test analyte for the obstruction factor measurement. The obstruction factor was determined to be 0.72 with a SD of (±0.01), which is consistent with the concept that organic porous polymer monoliths are more permeable than traditional LC stationary phases.
New capillary coatings in open tubular CEC as models for biological membranes
Authors: Martma Kert , Fernaeus Sandra Zetterström , Land Tiit , Shimmo Ruth
Published: March 2010

Novel stationary phases in open tubular CEC were investigated. The coating procedure was fast and simple. The coating material contained membrane suspension of different neuronal cell lines. The performance and stability of three cell lines: human neuroblastoma SH‐SY5Y, murine microglia Bv‐2 and human glioma U87‐MG cells were studied. The coating solution was expected to contain both membrane proteins and membrane lipids. The presence of membrane proteins was tested by Western blotting and the presence of phospholipids by the analysis of phosphorus content. The stability of the coating was estimated by monitoring the mobility of EOF over successive runs. The effects of pH, storage time and temperature on the coating stability were also studied. The results showed that the cell membrane‐based coating was stable over pH range of 6.5–8.5. Coatings derived from different cells yielded similar stability and EOF mobility. Capillary coated with a membrane solution was stable over 3‐day period. The same coating solution could be used for 3 weeks.
Simultaneous analysis of multiple PCR amplicons enhances capillary SSCP discrimination of MHC alleles
Authors: Alcaide Miguel , López Lidia , Tanferna Alessandro , Blas Julio , Sergio Fabrizio , Hiraldo Fernando
Published: March 2010

Major histocompatibility complex (MHC) genotyping still remains one of the most challenging issues for evolutionary ecologists. To date, none of the proposed methods have proven to be perfect, and all provide both important pros and cons. Although denaturing capillary electrophoresis has become a popular alternative, allele identification commonly relies upon conformational polymorphisms of two single‐stranded DNA molecules at the most. Using the MHC class II (β chain, exon 2) of the black kite (Aves: Accipitridae) as our model system, we show that the simultaneous analysis of overlapping PCR amplicons from the same target region substantially enhances allele discrimination. To cover this aim, we designed a multiplex PCR capable to generate four differentially sized and labeled amplicons from the same allele. Informative peaks to assist allele calling then fourfold those generated by the analysis of single PCR amplicons. Our approach proved successful to differentiate all the alleles (N=13) isolated from eight unrelated birds at a single optimal run temperature and electrophoretic conditions. In particular, we emphasize that this approach may constitute a straightforward and cost‐effective alternative for the genotyping of single or duplicated MHC genes displaying low to moderate sets of divergent alleles.
Separation of propranolol enantiomers by CE using sulfated β‐CD derivatives in aqueous and non‐aqueous electrolytes: Comparative CE and NMR study
Authors: Servais Anne‐Catherine , Rousseau Anne , Fillet Marianne , Lomsadze Ketevan , Salgado Antonio , Crommen Jacques , Chankvetadze Bezhan
Published: March 2010

Separations using CE employing non‐aqueous BGE are already as well established as separations in aqueous buffers. The separation mechanisms in achiral CE with non‐aqueous BGEs are most likely similar to those in aqueous buffers. However, for the separation of enantiomers involving their interaction with chiral buffer additives, the interaction mechanisms might be very different in aqueous and non‐aqueous BGEs. While the hypothesis regarding distinct mechanisms of enantiomer separations in aqueous and non‐aqueous BGEs has been mentioned in several papers, no direct proof of this hypothesis has been reported to date. In the present study, the enantiomers of propranolol were resolved using CE in aqueous and non‐aqueous methanolic BGEs with two single isomer sulfated derivatives of β‐CD, namely heptakis (2,3‐diacetyl‐6‐sulfo)‐β‐CD and heptakis (2,3‐dimethyl‐6‐sulfo)‐β‐CD. The enantiomer migration order of propranolol was inverted when an aqueous BGE was replaced with non‐aqueous BGE in the case of heptakis (2,3‐dimethyl‐6‐sulfo)‐β‐CD but remained the same in the case of heptakis (2,3‐diacetyl‐6‐sulfo)‐β‐CD. The possible molecular mechanisms leading to this reversal of enantiomer migration order were studied by using nuclear overhauser effect spectroscopy in both aqueous and non‐aqueous BGEs.
Enhanced selectivity in CZE multi‐chiral selector enantioseparation systems: Proposed separation mechanism
Authors: Dubský Pavel , Svobodová Jana , Tesařová Eva , Gaš Bohuslav
Published: March 2010

It has been reported many times that the commercial mixtures of chiral selectors (CS), namely highly sulfated β‐CDs (HS‐β‐CDs), provide remarkable enantioselectivity in CZE when compared with single‐isomer CDs, even single‐isomer HS‐β‐CDs. This enhanced enantioselectivity of multi‐CS enantioseparative CZE is discussed in the light of multi‐CS model that we have introduced earlier. It is proposed on a theoretical basis and verified experimentally that the two enantiomers of a chiral analyte under interaction with a mixture of CSs are very likely to differ in their limit mobilities, which is opposite to single‐CS systems where the two limit mobilities are likely to be the same. Thus while the enantioseparation is usually controlled by different distribution constants between the two enantiomers and CS used in single‐CS systems, an additional, electrophoretic, enantioselective mechanism resulting from different limit mobilities may play a significant role in multi‐CS systems. This additional mechanism generally makes the multi‐CS systems more selective than the single‐CS systems. The possible inequality of limit mobilities is also significant for optimization of separation conditions using mixtures of CSs. A practical example supporting our considerations is shown on enantioseparation of lorazepam in the presence of a commercial mixture of HS‐β‐CDs and a single‐isomer HS‐β‐CD, heptakis(6‐O‐sulfo)‐β‐CD.
Determination of free and total levels of phenytoin in human plasma from patients with epilepsy by MEKC: An adequate alternative to HPLC
Authors: Lin Ping‐Chih , Hsieh Ya‐Hui , Liao Fen‐Fen , Chen Su‐Hwei
Published: March 2010

Phenytoin is a widely used anti‐seizure agent, and a good correlation is observed between its concentration in plasma and the clinical effect. We developed a selective CE with UV detection at 200 nm for analysis of free and total levels of phenytoin in human plasma based on MEKC. A sample pretreatment by liquid–liquid extraction with ethyl acetate for determination of total level of phenytoin and serum ultrafiltrate was prepared by ultrafiltration technique (ultrafiltration membrane 30 kDa; 2000 g, 10 min) for determination of free level of phenytoin and subsequent quantification by MEKC was used. MEKC was performed in Tris buffer (25 mM; pH 10.5) containing SDS (180 mM) and EG (13%) as BGE. Hydrodynamic injection for phenytoin determination (0.5 psi 5 s for total level, 2 psi 5 s for free level) was used to introduce samples. The separation voltage was set at 20 kV. Data obtained by MEKC were compared with the results by a validated HPLC method. The MEKC assay of phenytoin exhibited a very good correlation with respect to HPLC by Bland–Altman method. The equations for the Passing–Bablok regression line were as follows: for total level: MEKC=1.0143×HPLC+0.0976, r2=1; for free level: MEKC=1.0013×HPLC–0.0016, r2=1. The proposed method was applied successfully to monitor free and total levels of phentoin in 20 patients with seizures.
Efficient implementation of the proper outlet flow conditions in blood flow simulations through asymmetric arterial bifurcations
Authors: Johnson David A. , Naik Ulhas P. , Beris Antony N.
Published: March 2010

We present an efficient implementation of the proper (in vivo) outlet boundary conditions in detailed, three‐dimensional (3D) and time‐periodic simulations of blood flow through arteries. This is achieved through the intermediate use of an approximate ‘simulant’ model of the outlet pressure/flow relationship corresponding to the full 3D and time‐dependent numerical simulation. This model allows us to efficiently couple the 3D outlet pressure/flow conditions to the equivalent relations due to the downstream arterial network, as obtained from a one‐dimensional approximate model in the form of Fourier frequency impedance coefficients. An adjustable time‐periodic function correction term in the simulant model requires input from the full 3D model that has to run iteratively until convergence. The advantage of the proposed numerical scheme is that it decouples the upstream detailed simulation from the downstream approximate network model offering exceptional versatility. This approach is demonstrated here in a series of detailed 3D simulations of blood flow, performed using the commercial software FLUENT™, through an asymmetric arterial bifurcation. Two cases are considered: first a healthy system patterned after the left main coronary arterial bifurcation, and second a diseased case where an occlusion has developed in one of the daughter vessels, resulting in strengthening the asymmetry of the bifurcation. Rapid convergence of the iterative process was achieved in both cases. Subtle changes occur in the shear patterns of the daughter vessels, whereas the flow distribution is quite different. In the presence of a stenosis additional regions of low shear develop due to inertial effects. Copyright © 2010 John Wiley & Sons, Ltd.
Temoporfin‐mediated photodynamic therapy in patients with advanced, incurable head and neck cancer: A multicenter study
Authors: Tan Ing Bing , Dolivet Gilles , Ceruse Philippe , Poorten Vincent Vander , Roest Gerda , Rauschning Winrich
Published: March 2010

Background.

The aim of this study was to confirm the efficacy of temoporfin (Foscan)‐mediated photodynamic therapy (PDT) in patients with end‐stage head and neck squamous cell carcinoma (HNSCC).

Methods.

Thirty‐nine patients with recurring HNSCC lesions ≤10 mm in depth were injected with temoporfin, followed by illumination of the tumor surface.

Results.

Of 39 treated patients, 19 achieved complete response, 2 partial response, 5 stable disease, 5 had progressive disease, and 8 patients were nonevaluable. Thus, in the per‐protocol analysis, the response rate was 68%. Of the treated patients 54% had a response. Median survival was significantly longer for responders (37 months) than for nonresponders (7.4 months). Nine patients were alive at 3.7 to 6.5 years (median, 4.8 years) post‐treatment, 7 free of disease. No major toxicities were observed.

Conclusions.

Patients with advanced HNSCC with lesions ≤10 mm in depth, who have exhausted other treatment options, can achieve significant local control and survival benefit from temoporfin‐mediated PDT. © 2010 Wiley Periodicals, Inc. Head Neck, 2010
Mastoid recurrence after radiotherapy for nasopharyngeal carcinoma: Two case studies
Authors: Zhang Ximei , Luo Jingwei , Gao Li , Xu Guozhen
Published: March 2010

Background.

The mastoid is a rare site of nasopharyngeal carcinoma recurrence after radiotherapy, and no relevant reports are currently in the literature.

Methods.

Two case reports are presented describing patients with a history of nasopharyngeal carcinoma who received primary radical radiotherapy. The first was treated by conventional radiotherapy, using 2‐dimensional techniques, while the second was delivered by intensity‐modulated radiation therapy (IMRT).

Results.

The patients presented with progressive mastoid recurrence after radiotherapy at 12 and 16 months, respectively. Clinical presentation of mastoid recurrence was similar to mastoiditis. Meanwhile, distant metastasis occurred in both cases. To date, 1 has died of distant metastasis, and the other is alive with disease stabilization following chemotherapy treatment.

Conclusion.

This is the first report of mastoid recurrence after radiotherapy for nasopharyngeal carcinoma, which should alert clinicians to probe into the pathogenesis and pay attention to the relationship between mastoid recurrence and distant metastasis. © 2010 Wiley Periodicals, Inc. Head Neck, 2010
SPECT/CT for sentinel lymph node mapping in head and neck melanoma
Authors: Vermeeren Lenka , Valdés Olmos Renato A. , Klop W. Martin C. , van der Ploeg Iris M. C. , Nieweg Omgo E. , Balm Alfons J. M. , van den Brekel Michiel W. M.
Published: March 2010

Background.

The additional value of single photon emission computed tomography with CT (SPECT/CT) for detection and localization of sentinel nodes in patients with a melanoma of the head and neck was determined.

Methods.

Thirty‐eight patients received conventional lymphoscintigraphy followed by hybrid SPECT/CT. The number of sentinel nodes visualized and anatomic information provided were analyzed. Changes in surgical approach due to additional information from the SPECT/CT were evaluated in 20 patients.

Results.

SPECT/CT visualized a mean of 2.6 sentinel nodes per patient (range, 1–6). SPECT/CT depicted an additional sentinel node in 16% of the patients and clearly showed the anatomic location of the hot nodes in all patients. The surgical approach was adjusted on the basis of SPECT/CT images in 11 patients (55%).

Conclusion.

SPECT/CT visualizes more sentinel nodes than conventional images and shows their anatomic location. SPECT/CT is recommended in patients with a melanoma in the head or neck. © 2010 Wiley Periodicals, Inc. Head Neck, 2011