bluuebunny/crossref_metadata_2025_split huggingface dataset:
ADHD in Dutch adults: Heritability and linkage study
Authors: Saviouk Viatcheslav , Hottenga Jouke‐Jan , Slagboom Eline P. , Distel Marijn A. , de Geus Eco J.C. , Willemsen Gonneke , Boomsma Dorret I. 
Published: February 2011

AbstractAttention deficit/hyperactivity disorder (ADHD) is a neurodevelopmental phenotype that persists into adulthood. This study investigated the heritability of inattentive and hyperactive symptoms and of total ADHD symptomatology load (ADHD index) in adults and performed linkage scans for these dimensions. Data on sibling pairs and their family members from the Netherlands Twin Register with genotype and phenotype data for inattention, hyperactivity and ADHD index (∼750 sib‐pairs) were analyzed. Phenotypes were assessed with the short self‐report form of the Conners' Adult ADHD Rating Scales (CAARS). Heritabilities were estimated in SOLAR under polygenic models. Genome‐wide linkage scans were performed using variance components (VC) in MERLIN and MINX and model‐based linkage analysis was carried out in MENDEL with empirical evaluation of the results via simulations. Heritability estimates for inattention, hyperactivity and ADHD index were 35%, 23%, and 31%, respectively. Chromosomes 18q21.31–18q21.32 (VC LOD = 4.58, pemp = 0.0026) and 2p25.1 (LOD = 3.58, pemp = 0.0372) provided significant evidence for linkage for inattention and the ADHD index, respectively. The QTL on chromosome 2p25.1 also showed suggestive linkage for hyperactivity. Two additional suggestive QTLs for hyperactivity and the ADHD index shared the same location on chromosome 3p24.3–3p24.1. Finally, a suggestive QTL on 8p23.3–8p23.2 for hyperactivity was also found. Heritability of inattention, hyperactivity and total ADHD symptoms is lower in adults than in children. Chromosomes 18q and 2p are likely to harbor genes that influence several aspects of adult ADHD. © 2011 Wiley‐Liss, Inc.
Familial transmission of schizophrenia in Palau: A 20‐year genetic epidemiological study in three generations
Authors: Myles‐Worsley Marina , Tiobech Josepha , Blailes Francisca , Middleton Frank A. , Vinogradov Sophia , Byerley William , Faraone Stephen V. 
Published: February 2011

AbstractOur genetic epidemiological studies of schizophrenia and other psychotic disorders (SCZ) in the isolated population of Palau have been ongoing for 20 years. Results from the first decade showed that Palau has an elevated prevalence of SCZ and that cases cluster in extended multigenerational pedigrees interconnected via complex genetic relationships after centuries of endogamous, but not consanguineous, marriages. The aim of our second decade of research, which extended data collection into a third generation of young, high‐risk (HR) Palauans, was to identify significant predictors of intergenerational transmission of illness. Our findings revealed that degree of familial loading and gender effects on reproductive fitness are important modifiers of risk for transmission of SCZ. Among 45 distinct multiplex families, we identified 10 high‐density (HD) Palauan families, each with 7–29 SCZ cases, which contain half of Palau's 260 SCZ cases and 80% of the 113 SCZ cases with one or more affected first‐degree relatives, indicating that familial loading is a major risk factor for SCZ in Palau. Cases that belong to multiply affected sibships are more common than cases with an affected parent. Furthermore, only 6/38 multiply affected sibships have an affected parent, strong evidence that many unaffected parents are obligate carriers of susceptibility genes. Although reproductive fitness is dramatically reduced in affected males, the 30% minority who do become fathers are twice as likely as affected mothers to transmit SCZ to an offspring. As they evolve, these HD families can help to elucidate the genetic mechanisms that predict intergenerational transmission of SCZ. © 2011 Wiley‐Liss, Inc.
Variation in NGFB is associated with primary affective disorders in women
Authors: Cui Donghong , Zhang Huiping , Yang Bao‐Zhu , Listman Jennifer B. , Li Dawei , Price Lawrence H. , Carpenter Linda L. , Tyrka Audrey R. , Anton Raymond F. , Kranzler Henry R. , Gelernter Joel 
Published: February 2011

AbstractAffective disorders (AFDs) are highly comorbid with substance dependence (SD) and both are genetically influenced. However, the specific etiology of the comorbidity is not well understood. We genotyped an array of 1,350 single nucleotide polymorphisms (SNPs) in or near 130 genes in 868 European‐Americans (EAs), including 182 individuals with primary AFDs (PAFDs), 214 with SD comorbid with AFD (CAFD), and 472 screened controls. NGFB, which encodes nerve growth factor β and was represented in the array by 15 SNPs, showed the strongest evidence of association, but only among women with PAFDs. Six of the SNPs showed nominally significant association with PAFDs in women (P's = 0.0007–0.01); three (rs2856813, rs4332358, and rs10776799) were empirically significant based on 1,000,000 permutations (P's = 0.008–0.015). Seven haplotypes were significantly associated with PAFDs in women (P's = 0.0014–0.01), of which six were significant based on empirical permutation analysis (minimal P = 0.0045). Four diplotypes were significantly associated with PAFDs in women (global P's = 0.001–0.01). The specific diplotype GG‐TC, reconstructed from rs2856813 and rs6678788, showed the strongest evidence of association with PAFDs in women (OR = 4.07, P = 4.2E−05). No SNPs or haplotypes were associated with PAFDs in men or with CAFDs in either sex. We conclude that variation in NGFB is a risk factor for PAFDs in women, but not for CAFD. © 2011 Wiley‐Liss, Inc.
Performance of reclassification statistics in comparing risk prediction models
Authors: Cook Nancy R. , Paynter Nina P. 
Published: February 2011

AbstractConcerns have been raised about the use of traditional measures of model fit in evaluating risk prediction models for clinical use, and reclassification tables have been suggested as an alternative means of assessing the clinical utility of a model. Several measures based on the table have been proposed, including the reclassification calibration (RC) statistic, the net reclassification improvement (NRI), and the integrated discrimination improvement (IDI), but the performance of these in practical settings has not been fully examined. We used simulations to estimate the type I error and power for these statistics in a number of scenarios, as well as the impact of the number and type of categories, when adding a new marker to an established or reference model. The type I error was found to be reasonable in most settings, and power was highest for the IDI, which was similar to the test of association. The relative power of the RC statistic, a test of calibration, and the NRI, a test of discrimination, varied depending on the model assumptions. These tools provide unique but complementary information.
Dysregulation of Claudin family genes in colorectal cancer in a Chinese population
Authors: Tang Weijun , Dou Tonghai , Zhong Ming , Wu Zhiyong 
Published: February 2011

AbstractClaudins play an important role in tumor metastasis and in invasiveness of colorectal cancer (CRC). We have evaluated the relationship between CRC and expression of the claudin genes in Chinese patients with CRC. We measured CLDN1 and CLDN7 mRNA using quantitative PCR, and protein levels with immunohistochemistry in cancer tissues and adjacent normal tissue. Cancer tissues had significantly higher levels of CLDN1, and significantly lower levels of CLDN3, CLDN4, and CLDN7 than did normal tissue. CLDN3, CLDN4, and CLDN7 expression levels were higher in CRC of the protruded type than in CRC of the infiltrative type. Expression of CLDN7 correlated with lymph node metastasis. Stage N0 cancer tissues had higher levels of CLDN7 than did stages N1 and N2, suggesting that CLDN7 expression was closely related to the extent of lymph node metastasis. CLDN1 protein was upregulated, but CLDN7 protein was downregulated in cancer tissues when compared with expression in adjacent normal tissues. In conclusion, CLDN3, CLDN4, and CLDN7 were significantly downregulated, whereas CLDN1 was significantly upregulated in CRC. The altered expression of claudin genes may play a role in the initiation and development of CRC.
Synthesis and characterization of cyclic and linear helical poly(α‐peptoid)s by N‐heterocyclic carbene‐mediated ring‐opening polymerizations of N‐substituted N‐carboxyanhydrides
Authors: Guo Li , Li Jinhai , Brown Zachary , Ghale Kushal , Zhang Donghui 
Published: February 2011

AbstractCyclic poly(α‐peptoid)s [a.k.a. poly(N‐R‐glycine)] with chiral aromatic side‐chains [R = (R)‐ or (S)‐CHMePh] have been synthesized by N‐heterocyclic carbene‐mediated ring‐opening polymerization of N‐substituted N‐carboxyanhydrides (NR‐NCA). Their linear analogs have been prepared by primary amine‐initiated polymerization of the corresponding NR‐NCA. Poly[(R)/(S)‐N‐CHMePh‐glycine] with polymer molecular weights (MWs) in the range of 4–15 kg mol−1 and low MW distribution (Polydispersity index (PDI) < 1.15) can be readily accessed by these methods. Their high MW analogs were not obtained due to the competitive formation of cyclic oligomeric species that result from intramolecular transamidation. Intrinsic viscosity measurements confirm the architectural difference between the polymers prepared by the two methods and reveals that both cyclic and linear poly[(S)‐N‐CHMePh‐glycine]s behave as random‐coil polymers in 0.1M LiBr/Dimethylformamide (DMF) solution. Circular dichroism analysis suggests that the cyclic and linear poly(α‐peptoid)s retain polyproline I helix conformations, analogously to previously reported linear oligomers. Differential scanning calorimetry analysis reveals that cyclic and linear poly[(S)‐N‐CHMePh‐glycine] are both amorphous with the glass transition temperature of the cyclic polymers (Tg = 122°C) being notably higher than that of the linear analogs (Tg = 112°C) with identical MW. These results are consistent with the absence of chain ends, causing the polymers to have reduced segmental mobilities. © 2011 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 96: 596–603, 2011.
The unique plant RhoGAPs are dimeric and contain a CRIB motif required for affinity and specificity towards cognate small G proteins
Authors: Schaefer Antje , Höhner Kathrin , Berken Antje , Wittinghofer Alfred 
Published: February 2011

AbstractPlant Rho proteins (ROPs) are inactivated by specific GTPase activating proteins, called RopGAPs. Many of these comprise the exclusive combination of a classic, catalytic Arg‐containing RhoGAP domain, and a Cdc42/Rac interactive binding (CRIB) motif which in animal and fungi has been identified in effectors for Cdc42 and Rac1, but never in any GAP protein. Both elements are required for an efficient RopGAP activity. Here, we analyzed the effect of the CRIB motif on the complex formation and the binding reaction with plant and human Rho proteins by using kinetic and equilibrium methods. We show that RopGAP2 from Arabidopsis thaliana dimerizes via its GAP domain and forms a 2:2 complex with ROP. The CRIB effector motif mediates high affinity and specificity in binding. The catalytic Arg in the context of the CRIB motif is inhibitory for binding. The unusually slow association and dissociation reactions suggest a major conformational change whereby the CRIB motif functions as a lid for binding and/or release of ROP. We propose a two‐site interaction model where ROP binds to the CRIB motif as described for the human CRIB effectors and to the catalytic GAP domain as described for animal RhoGAPs. © 2011 Wiley Periodicals, Inc. Biopolymers 95: 420–433, 2011
Rapid determination of rifaximin on dried blood spots by LC‐ESI‐MS
Authors: Nageswara Rao R. , Vali R. Mastan , Ramachandra Bondigalla , Maurya Pawan K. 
Published: February 2011

ABSTRACTThe use of blood spot collection cards is a simple way to obtain specimens for therapeutic drug monitoring, assessing adherence to medications and preventing toxicity in a clinical setting. A high‐throughput liquid chromatography–electrospray ionization mass spectrometric (LC‐ESI‐MS) method for determination of rifaximin on dried blood spots (DBS) was developed and validated. It involves solvent extraction of a punch of DBS followed by reversed‐phase LC on a monolithic column consisting of a silica rod with bimodal pore structure and detection by ESI‐MS. Rifampicin was used as an internal standard (IS). The run time was within 5.0 min with a very low back‐pressure at a flow rate of 0.5 mL/min. The assay was linear from 0.1 to 10 ng/mL. The mean recovery was 98.42%. The developed method is very simple, rapid and useful for clinical applications. Copyright © 2011 John Wiley & Sons, Ltd.
Effects of Acidity and Pore Size Constraints on Supported Niobium Oxide Catalysts for the Selective Formation of Glycerol Monolaurate
Authors: Radhakrishnan Rajitha , Wu Jiang , Jaenicke Stephan , Chuah Gaik Khuan 
Published: February 2011

AbstractSupported niobium oxide catalysts with 5–30 wt. % Nb2O5 were prepared by grafting niobium ethoxide onto MCM‐41 and hydrous zirconia. The supported samples contain Brønsted‐acid sites, whereas bulk niobium oxide has predominantly Lewis‐acid sites. In the esterification of glycerol with lauric acid, good activity and a high glycerol monolaurate selectivity was achieved when the active niobium oxide phase was coated within the pore channels of an MCM‐41 support, which has a mean pore diameter of 2.2 nm. Phosphated Nb2O5/MCM‐41 showed an even higher activity without any penalty in selectivity, enabling monolaurate yields of 89–90 %. Glycerol monolaurate is an important ingredient in the food, pharmaceutical, and cosmetic industries. A key feature of these pore confined catalysts is the sustained high selectivity to monolaurate even at high conversions. In contrast, niobium oxide supported on wide‐pored hydrous zirconia showed lower selectivity. The catalysts are active in the solventless esterification of a number of alcohols and acids and can be easily recycled for subsequent batch reactions, making them attractive as green catalysts for sustainable processes.
γ‐ and δ‐Lactams through Palladium‐Catalyzed Intramolecular Allylic Alkylation: Enantioselective Synthesis, NMR Investigation, and DFT Rationalization
Authors: Bantreil Xavier , Prestat Guillaume , Moreno Aitor , Madec David , Fristrup Peter , Norrby Per‐Ola , Pregosin Paul S. , Poli Giovanni 
Published: February 2011

AbstractThe Pd‐catalyzed intramolecular allylic alkylation of unsaturated amides to give γ‐ and δ‐lactams has been studied in the presence of chiral ligands. Ligand (R)‐3,5‐tBu‐MeOBIPHEP (MeOBIPHEP=6,6’‐dimethoxybiphenyl‐2,2‐diyl)bis(diphenylphosphine)) afforded the best results and allowed the cyclization reactions to take place in up to 94:6 enantiomeric ratio. A model Pd–allyl complex has been prepared and studied through NMR spectroscopic analysis, which provided insight into the processes responsible for the observed enantiomeric ratios. DFT studies were used to characterize the diastereomeric reaction pathways. The calculated energy differences were in good agreement with the experimentally observed enantiomeric ratios.
Fluoride‐Cleavable, Fluorescently Labelled Reversible Terminators: Synthesis and Use in Primer Extension
Authors: Knapp Diana C. , Serva Saulius , D'Onofrio Jennifer , Keller Angelika , Lubys Arvydas , Kurg Ants , Remm Maido , Engels Joachim W. 
Published: February 2011

AbstractFluorescent 2′‐deoxynucleotides containing a protecting group at the 3′‐O‐position are reversible terminators that enable array‐based DNA sequencing‐by‐synthesis (SBS) approaches. Herein, we describe the synthesis and full characterisation of four reversible terminators bearing a 3′‐blocking moiety and a linker‐dye system that is removable under the same fluoride‐based treatment. Each nucleotide analogue has a different fluorophore attached to the base through a fluoride‐cleavable linker and a 2‐cyanoethyl moiety as the 3′‐blocking group, which can be removed by using a fluoride treatment as well. Furthermore, we identified a DNA polymerase, namely, RevertAid M‐MuLV reverse transcriptase, which can incorporate the four modified reversible terminators. The synthesised nucleotides and the optimised DNA polymerase were used on CodeLink slides spotted with hairpin oligonucleotides to demonstrate their potential in a cyclic reversible terminating approach.
Well‐Defined Air‐Stable Palladium HASPO Complexes for Efficient Kumada–Corriu Cross‐Couplings of (Hetero)Aryl or Alkenyl Tosylates
Authors: Ackermann Lutz , Kapdi Anant R. , Fenner Sabine , Kornhaaß Christoph , Schulzke Carola 
Published: February 2011

AbstractPalladium complexes of representative heteroatom‐substituted secondary phosphine oxide (HASPO) preligands were synthesized and fully characterized, including X‐ray crystal structure analysis. Importantly, these well‐defined complexes served as highly efficient catalysts for Kumada–Corriu cross‐coupling reactions of aryl, alkenyl, and even heteroaryl tosylates. Particularly, an air‐stable catalyst derived from inexpensive PinP(O)H displayed a remarkably high catalytic efficacy, which resulted in cross‐couplings at low catalyst loadings under exceedingly mild reaction conditions with ample scope.
A Fully Conjugated TTF–π–TCAQ System: Synthesis, Structure, and Electronic Properties
Authors: Santos José , Illescas Beatriz M. , Martín Nazario , Adrio Javier , Carretero Juan C. , Viruela Rafael , Ortí Enrique , Spänig Fabian , Guldi Dirk M. 
Published: February 2011

AbstractThe synthesis of the first fully conjugated tetrathiafulvalene–tetracyano‐p‐quinodimethane ((TTF)–TCNQ)‐type system has been carried out by means of a Julia–Kocienski olefination reaction. In particular, a tetracyanoanthraquinodimethane (TCAQ) formyl derivative and two new sulfonylmethyl‐exTTFs (exTTF=2‐[9‐(1,3‐dithiol‐2‐ylidene)anthracen‐10(9H)‐ylidene]‐1,3‐dithiole)—prepared as new building blocks—were linked. A variety of experimental conditions reveal that the use of sodium hexamethyldisilazane (NaHMDS) as base in THF afforded the E olefins with excellent stereoselectivity. Theoretical calculations at the B3LYP/6‐31G** level point to highly distorted exTTF and TCAQ that form an almost planar stilbene unit between them. Although calculations predicted appreciable electronic communication between the donor and the acceptor, cyclic voltammetric studies did not substantiate this effect. It was only in photophysical assays that the electronic communication emerged in the form of a charge‐transfer (CT) absorption and emission. Once photoexcited (i.e., the locally excited state or excited charge‐transfer state), an ultrafast, subpicosecond charge separation leads to a radical ion pair state in which the spectroscopic features of the radical cation of exTTF as well as the radical anion of TCAQ are discernable. The radical ion pair is metastable and undergoes a fast ((1.0±0.2) ps) charge recombination to reconstitute the electronic ground state. Such ultrafast charge separation and recombination processes come as a consequence of the very short vinyl linkage between the two electroactive units.
ChemInform Abstract: Low Thermal Expansion Behavior and Electrical Conductivity of Mn3(Cu0.5SixGe0.5‐x)N at Low Temperatures.
Authors: Huang Rongjin , Wu Zhixiong , Chu Xinxin , Yang Huihui , Chen Zhen , Li Laifeng 
Published: February 2011

AbstractThe title compounds (x = 0.05, 0.1, 0.15, 0.2) are prepared by ball milling of mixtures of the elements followed by sintering (Ta foil, Ar, 850 °C, 48 h).
ChemInform Abstract: Preparation and Luminescence Properties of Green‐Light‐Emitting Afterglow Phosphor Ca8Mg(SiO4)4Cl2:Eu2+.
Authors: Lei Bingfu , Sha Lei , Zhang Haoran , Liu Yingliang , Man Shi‐qing , Yue Song 
Published: February 2011

AbstractThe title phosphor is synthesized by solid state reaction of Ca2SiO4:Eu2+ (obtained from CaCO3, SiO2, and Eu2O3 in alumina crucibles in a reducing 95%/5% N2/H2 gas flow at 1200 °C for 3 h), MgCl2, and NH4Cl as a flux (N2, 900 °C, 3 h).
ChemInform Abstract: Stabilization of a Complex Perovskite Superstructure under Ambient Conditions: Influence of Cation Composition and Ordering, and Evaluation as an SOFC Cathode.
Authors: Demont A. , Dyer M. S. , Sayers R. , Thomas M. F. , Tsiamtsouri M. , Niu H. N. , Darling G. R. , Daoud‐Aladine A. , Claridge J. B. , Rosseinsky M. J. 
Published: February 2011

AbstractBa1.6Ca2.3Y1.1Fe5O13 is an FeIII oxide with a complex perovskite superstructure, which is an intergrowth between the Ca2Fe2O5 and YBa2Fe3O8 structures featuring octahedral, square pyramidal, and tetrahedral B sites and three distinct A site environments.
ChemInform Abstract: A New Layered Indium Selenium Oxychloride Material: Synthesis, Structure, and Characterization of InSeO3Cl.
Authors: Lee Dong Woo , Ok Kang Min 
Published: February 2011

AbstractThe new title compound is synthesized as single phase by solid state reaction of a 1:1:3 mixture of In2O3, InCl3, and SeO2 (evacuated silica tube, 500 °C, 24 h).
ChemInform Abstract: High‐Pressure Synthesis and Crystal Structure of the New Holmium Oxoborate Ho31O27(BO3)3 (BO4)6.
Authors: Hering Stefanie A. , Haberer Almut , Kaindl Reinhard , Huppertz Hubert 
Published: February 2011

AbstractThe new title compound is synthesized in a modified Walker‐type module from a mixture of Ho2O3 and B2O3 (7.5—11.5 GPa, 1200 °C, 10 min).
ChemInform Abstract: Studies Regarding the Homogeneity Range of the Zirconium Phosphide Telluride Zr2+δPTe2.
Authors: Tschulik Kristina , Hoffmann Stefan , Fokwa Boniface P. T. , Gillessen Michael , Schmidt Peer 
Published: February 2011

AbstractSingle‐phase samples of the title compounds with 0 ≤ δ ≤ 1 are synthesized by solid state reaction of the elements (800 °C, 120 h).
ChemInform Abstract: A Facile Approach to Substituted Acrylates by Regioselective and Stereoselective Addition of Thiols and Amines to an Alkynyl Ester in Water.
Authors: Randive Nitin A. , Kumar Varun , Nair Vipin A. 
Published: February 2011

AbstractA simple, efficient, and environmentally friendly reaction procedure for the stereoselective formation of thioacrylates and β‐enamino esters without employing any hazardous reagent or solvent is presented.
ChemInform Abstract: Amine‐Catalyzed (3 + n) Annulations of 2‐(Acetoxymethyl)buta‐2,3‐dienoates with 1,n‐Bisnucleophiles (n = 3—5).
Authors: Li Chaolong , Zhang Qiongmei , Tong Xiaofeng 
Published: February 2011

AbstractA number of heterocyclic compounds is synthesized in good yields by DABCO‐catalyzed [3 + n] cyclization reactions (n = 3‐5).
ChemInform Abstract: Biginelli and Hantzsch‐Type Reactions Leading to Highly Functionalized Dihydropyrimidinone, Thiocoumarin, and Pyridopyrimidinone Frameworks via Ring Annulation with β‐Oxodithioesters.
Authors: Nandi Ganesh Chandra , Samai Subhasis , Singh Maya Shankar 
Published: February 2011

AbstractH2SO4‐SiO2‐mediated treatment of the dithioesters (I) with aldehydes and urea provides a convenient approach to dihydropyrimidinones of type (IV).
ChemInform Abstract: A Useful, Reliable and Safer Protocol for Hydrogenation and the Hydrogenolysis of O‐Benzyl Groups: The in situ Preparation of an Active Pd0/C Catalyst with Well‐Defined Properties.
Authors: Felpin Francois‐Xavier , Fouquet Eric 
Published: February 2011

AbstractA convenient protocol for Pd‐catalyzed hydrogenation of olefins as well as reductive debenzylation is presented.
ChemInform Abstract: m‐Iodosylbenzoic Acid as a Convenient Recyclable Hypervalent Iodine Oxidant for the Synthesis of α‐Iodo Ketones by Oxidative Iodination of Ketones.
Authors: Yusubov Mehman S. , Yusubova Rosa Y. , Funk Tatyana V. , Chi Ki‐Whan , Kirschning Andreas , Zhdankin Viktor V. 
Published: February 2011

AbstractThe hypervalent iodine oxidant, consisting of m‐iodosylbenzoic acid and iodine, iodinates various enolizable ketones and β‐dicarbonyl compounds under mild conditions providing the corresponding α‐iodo‐substituted carbonyl compounds in good to excellent yields.