bluuebunny/crossref_metadata_2025_split huggingface dataset:
Twin Gestation and Neurodevelopmental Outcome in Extremely Low Birth Weight Infants
Authors: Wadhawan Rajan , Oh William , Perritt Rebecca L. , McDonald Scott A. , Das Abhik , Poole W. Kenneth , Vohr Betty R. , Higgins Rosemary D. 
Published: January 2009

OBJECTIVE. The purpose of this work was to compare the risk-adjusted incidence of death or neurodevelopmental impairment at 18 to 22 months’ corrected age between twin and singleton extremely low birth weight infants. We hypothesized that twin gestation is independently associated with increased risk of death or adverse neurodevelopmental outcomes at 18 to 22 months’ corrected age in these infants.
METHODS. We conducted a retrospective study of inborn extremely low birth weight infants admitted to Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network units between 1997 and 2005, who either died or had follow-up data available at 18 to 22 months’ corrected age. Neurodevelopmental impairment, the primary outcome variable, was defined as the presence of any 1 of the following: moderate or severe cerebral palsy, severe bilateral hearing loss, bilateral blindness, Bayley Mental Developmental Index or Psychomotor Developmental Index of &lt;70. Death was included with neurodevelopmental impairment as a composite outcome. Results were compared for both twins, twin A, twin B, same-gender twins, unlike-gender twins, and singleton infants. Logistic regression analysis was performed to control for demographic and clinical factors that were different among the groups.
RESULTS. The cohort of infants who either died or were assessed for neurodevelopmental impairment consisted of 7630 singleton infants and 1376 twins. Logistic regression adjusting for clinical and sociodemographic risk factors showed an increased risk of death or neurodevelopmental impairment for twins as a group when compared with the singletons. On analyzing twin A and B separately as well, risk of death or neurodevelopmental impairment was increased in both twin A and twin B.
CONCLUSIONS. Twin gestation in extremely low birth weight infants is associated with an independent increased risk of death or neurodevelopmental impairment at 18 to 22 months’ corrected age compared with singleton-gestation infants. Both first- and second-born twins are at increased risk.
Acquisition of Word-Formation Categories by Children with Hearing Loss
Authors: Muzyka Ewa 
Published: January 2009

Acquisition of Word-Formation Categories by Children with Hearing LossThe article describes the competence of children with hearing loss in comprehending and producing derivational (word-formation constructions) belonging to various categories. The skills of children with hearing loss are compared with the skills of hearing children. The extensive field of observation - the object of study were all word-formation categories (productive in contemporary Polish) - caused this article to focus exclusively on quantitative analyses. The conclusions that follow from them allow us to determine the hierarchy of word-formation categories, ordered according to the degree of difficulty, and to compare the level of their acquisition by hearing children, hard-of-hearing children (using the hearing sense) and by deaf ones (not using the hearing sense). This hierarchy is different in the area of interpreting than in the area of producing derivational (word-formation) constructions. The degree of complication of the semantic structure of the categories investigated has a distinct effect on the level of their acquisition. If we adopt the view that the categorization of the world by the learning mind is reflected in derivational constructions, analyses of the abilities of children with hearing loss in this sphere of linguistic functions allow us to access the available subjective ways of how they perceive and interpret the phenomena of treality. The analyses proper are preceded by a description of the investigation instrument employed: a word-formation questionnaire, which is a methodological proposal for studying word formation in school-age children.
Lexical Skills in Alzheimer's Dementia (Based on the Material of Dialogue Utterances)
Authors: Domagała Aneta 
Published: January 2009

Lexical Skills in Alzheimer's Dementia (Based on the Material of Dialogue Utterances)
The paper discusses the lexical skills of adults with Alzheimer's dementia, assessed on the material of dialogue utterances. The paper presents a proposal for a way of describing lexical disorders in dementia and illustrates the problems commonly occurring in this group of patients. The linguistic analysis covered 1000 pages of transcripts of conversations with patients with moderate and severe intensity of dementia. In the discussion of the results, the most common symptoms of lexical disorders were presented that characterize functional behaviors in dementia: quasi-nomination with the use of the pronoun, transfer of a name, and delexicalization (dephraseologization). At the same time, the behaviors and reactions of patients were shown that appear in the situation of experiencing communication failures due to a decreased lexical skills.
Development and Testing of Energetic Materials: The Concept of High Densities Based on the Trinitroethyl Functionality
Authors: Göbel Michael , Klapötke Thomas M. 
Published: January 2009

AbstractThe development of new energetic materials is an emerging area of materials chemistry facilitated by a worldwide need to replace materials used at present, due to environmental considerations and safety requirements, while at the same time securing high performance. The development of such materials is complex, owing to the fact that several different and apparently mutually exclusive material properties have to be met in order for a new material to become widely accepted. In turn, understanding the basic principles of structure property relationships is highly desirable, as such an understanding would allow for a more rational design process to yield the desired properties. This article covers the trinitroethyl functionality and its potential for the design of next generation energetic materials, and describes relevant aspects of energetic materials chemistry including theoretical calculations capable of reliably predicting material properties. The synthesis, characterization, energetic properties, and structure property relationships of several new promising compounds displaying excellent material properties are reported with respect to different kinds of applications and compared to standard explosives currently used. Based on a review of trinitroethyl‐containing compounds available in the literature, as well as this new contribution, it is observed that high density can generally be obtained in a more targeted manner in energetic materials taking advantage of noncovalent bonding interactions, a prerequisite for the design of next generation energetic materials.
N,N‐Dimethylformamide as a Reaction Medium for Metal Nanoparticle Synthesis
Authors: Pastoriza‐Santos Isabel , Liz‐Marzán Luis M. 
Published: January 2009

AbstractThe versatility of wet chemical methods has rendered them extremely popular for the preparation of metal nanoparticles with tailored size and shape. This Feature Article reviews the use of N,N‐dimethylformamide (DMF) for the reduction of metal salts, mainly Au and Ag, while also acting as a solvent. Apart from describing the ability of DMF to reduce metal salts, the effect of different parameters, such as the concentration of capping agent and metal precursors, the presence of preformed seeds acting as catalysts or their crystalline structure, on particle morphology are analyzed. Published reports on the use of different capping agents are summarized, with particular emphasis on the role of poly(vinylpyrrolidone) to determine the morphology of the particles. Finally, a brief overview is provided on the modulation of the optical response in DMF‐based metal nanoparticle colloids with tunable size and shape.
Enzymatic Production of l‐Menthol by a High Substrate Concentration Tolerable Esterase from Newly Isolated Bacillus subtilis ECU0554
Authors: Zheng Gao‐Wei , Yu Hui‐Lei , Zhang Jian‐Dong , Xu Jian‐He 
Published: January 2009

Abstractmagnified imageEnzymatic preparation of l‐menthol has been attracting much attention in the flavor and fragrance industry. A new ideal strain, Bacillus subtilis ECU0554, which exhibited high hydrolytic activity and excellent enantioselectivity towards l‐menthyl ester, has been successfully isolated from soil samples through enrichment culture and identified as Bacillus subtilis by 16S rDNA gene sequencing. The esterase extracted from B. subtilis ECU0554 (BSE) showed the best catalytic properties (E>200) for dl‐menthyl acetate among the five menthyl esters examined. Enantioselective hydrolysis of 100 mM dl‐menthyl acetate at 30°C and pH 7.0, using crude BSE as biocatalyst and 10% ethanol (v/v) as cosolvent, resulted in 49.0% conversion (3 h) and 98.0% ee for the l‐menthol produced, which were much better than those using commercial enzymes tested. Moreover, BSE exhibited strong tolerance against high substrate concentration (up to 500 mM), and the concentration of l‐menthol produced could reach as high as 182 mM, and more importantly, the optical purity of l‐menthol produced was kept above 97% ee, which were not found in previous reports. These results imply that BSE is a potentially promising biocatalyst for the large‐scale enzymatic preparation of l‐menthol. Using this excellent biocatalyst, the enzymatic production of l‐menthol will become a mild, efficient, inexpensive and easy‐to‐use “green chemistry” methodology.
Ruthenium‐Catalyzed CH Bond Activation of Michael Acceptors: An Unusual Reactivity Leading to Allylsilanes
Authors: Simon Marc‐Olivier , Martinez Rémi , Genêt Jean‐Pierre , Darses Sylvain 
Published: January 2009

AbstractWe report here an improved catalyst for the functionalization of Michael acceptors, involving CC bond formation via CH bond activation, using an in situ generated ruthenium active species. Moreover, on some particular substrates, the CH functionalization resulted unexpectedly in the formation of allylsilanes rather than in the expected conjugated adducts, affording a new straightforward methodology to access useful stereodefined trisubstituted allylsilanes via CH bond activation. Preliminary results have shown that they were reactive in the allylation of aldehydes, providing an access to alcohols bearing a quaternary carbon center.
A Catalytic Asymmetric Electrocyclization‐Protonation Reaction
Authors: Rueping Magnus , Ieawsuwan Winai 
Published: January 2009

AbstractThe first enantioselective Brønsted acid‐catalyzed electrocyclization‐protonation reaction has been developed which provides a number of different cyclopentenones in good yields and with high enantioselectivities. The stereodetermining step of this asymmetric Nazarov cyclization reaction is an asymmetric Brønsted acid‐catalyzed kinetic protonation.
Highly Efficient Iron(II) Chloride/N‐Bromosuccinimide‐Mediated Synthesis of Imides and Acylsulfonamides
Authors: Wang Feng , Liu Hongxia , Fu Hua , Jiang Yuyang , Zhao Yufen 
Published: January 2009

AbstractWe have developed a general and highly efficient iron(II) chloride/N‐bromosuccinimide (NBS)‐mediated method for the synthesis of imides and acylsulfonamides via couplings of thioesters with carboxamides/sulfonamides, and the method is simple, economical and shows practical advantages.
Elucidation of Architectural Requirements from a Spacer in Supported Proline‐Based Catalysts of Enantioselective Aldol Reaction
Authors: Goren Kerem , Kehat Tzofit , Portnoy Moshe 
Published: January 2009

AbstractIn order to delineate the properties of the spacer architecture responsible for the strong positive dendritic effect exhibited by polymer‐supported proline‐based catalysts, we prepared two series of polystyrene‐bound model catalysts. The first series was based on a linear and partially dendritic spacers (of reduced branching and valency) imitating the length of the second generation spacer, while the second series was based on the first generation dendron spacer with one functional (proline‐terminated) and one non‐functional arm. Comparative studies of the model and original (fully dendritic) catalysts in the asymmetric aldol reaction of aromatic aldehydes with acetone disclose the features characteristic to the dendritic architecture, such as proximity between the terminal catalytic units and enhanced branching, as crucial for inducing higher yield and enantioselectivity in catalysis.
Achieving state estimation equivalence for misassigned disturbances in offset‐free model predictive control
Authors: Rajamani Murali R. , Rawlings James B. , Qin S. Joe 
Published: January 2009

AbstractIntegrated white noise disturbance models are included in advanced control strategies, such as Model Predictive Control, to remove offset when there are unmodeled disturbances or plant/model mismatch. These integrating disturbances are usually modeled to enter either through the plant inputs or the plant outputs or partially through both. There is currently a lack of consensus in the literature on the best choice for the structure of this disturbance model to obtain good feedback control. We show that the choice of the disturbance model does not affect the closed‐ loop performance if appropriate covariances are used in specifying the state estimator. We also present a data based autocovariance technique to estimate the appropriate covariances regardless of the plant's true unknown disturbance source. The covariances estimated using the autocovariance technique and the resulting estimator gain are shown to compensate for an incorrect choice of the source of the disturbance in the disturbance model. © 2009 American Institute of Chemical Engineers AIChE J, 2009
The underrecognized progressive nature of N370S Gaucher disease and assessment of cancer risk in 403 patients
Authors: Taddei Tamar H. , Kacena Katherine A. , Yang Mei , Yang Ruhua , Malhotra Advitya , Boxer Michael , Aleck Kirk A. , Rennert Gadi , Pastores Gregory M. , Mistry Pramod K. 
Published: January 2009

AbstractMutations in GBA1 gene that encodes lysosomal glucocerebrosidase result in Type 1 Gaucher Disease (GD), the commonest lysosomal storage disorder; the most prevalent disease mutation is N370S. We investigated the heterogeneity and natural course of N370S GD in 403 patients. Demographic, clinical, and genetic characteristics of GD at presentation were examined in a cross‐sectional study. In addition, the relative risk (RR) of cancer in patients compared with age‐, sex‐, and ethnic‐group adjusted national rates of cancer was determined. Of the 403 patients, 54% of patients were homozygous (N370S/N370S) and 46% were compound heterozygous for the N370S mutation (N370S/other). The majority of N370S/N370S patients displayed a phenotype characterized by late onset, predominantly skeletal disease, whereas the majority of N370S/other patients displayed early onset, predominantly visceral/hematologic disease, P < 0.0001. There was a striking increase in lifetime risk of multiple myeloma in the entire cohort (RR 25, 95% CI 9.17–54.40), mostly confined to N370S homozygous patients. The risk of other hematologic malignancies (RR 3.45, 95% CI 1.49–6.79), and overall cancer risk (RR 1.80, 95% CI 1.32–2.40) was increased. Homozygous N370S GD leads to adult‐onset progressive skeletal disease with relative sparing of the viscera, a strikingly high risk of multiple myeloma, and an increased risk of other cancers. High incidence of gammopathy suggests an important role of the adaptive immune system in the development of GD. Adult patients with GD should be monitored for skeletal disease and cancers including multiple myeloma. Am. J. Hematol., 2009. © 2009 Wiley‐Liss, Inc.
Nanomedizin – Herausforderung und Perspektiven
Authors: Riehemann Kristina , Schneider Stefan W. , Luger Thomas A. , Godin Biana , Ferrari Mauro , Fuchs Harald 
Published: January 2009

AbstractDie Anwendung nanotechnologischer Konzepte in der Medizin verbindet zwei große interdisziplinäre Wissenschaftsgebiete mit einem beispiellosen sozialen und ökonomischen Potenzial. Diese Nanomedizin nutzt die Errungenschaften beider Forschungsfelder, wobei die gemeinsame Basis die Untersuchung spezifischer Eigenschaften auf der Molekülebene ist. Mithilfe lokaler Sonden und molekularer Bildgebungstechniken können Oberflächen‐ und Grenzflächeneigenschaften auf der Nanometerskala an vorgegebenen Messpunkten charakterisiert werden, während es mit chemischen Methoden gelingt, Oberflächen kontrolliert zu modifizieren und zu adressieren. Beispiele hierfür sind neuartige Konzepte für den gezielten Wirkstofftransport, die Biokompatibilitätsoptimierung und neuroprothetische Anwendungen. Allerdings sind im Hinblick auf toxikologische sowie ethische Aspekte dieser Querschnittsdisziplin noch viele Fragen offen. Hier werden ausgewählte Entwicklungen nud Anwendungen der Nanomedizin besprochen.
XeF4 as a Ligand for a Metal Ion
Authors: Tavčar Gašper , Žemva Boris 
Published: January 2009

AbstractEdles Molekül: [Mg(XeF2)(XeF4)](AsF6)2 ist die erste Koordinationsverbindung, in der XeF4 als an ein Metallzentrum gebundener Ligand vorliegt. Es ist auch die erste bekannte Verbindung, in der XeF2 und XeF4 gemeinsam an dasselbe Metallzentrum binden (siehe Struktur; lila Xe, grün F, grau Mg, gelb As).magnified image
Palladium‐Catalyzed Substitution of Allylic Fluorides
Authors: Hazari Amaruka , Gouverneur Véronique , Brown John M. 
Published: January 2009

AbstractEin Sonderfall: Ungewöhnliche Substrate für die Tsuji‐Trost‐Allylierung sind Allylfluoride, die palladiumkatalysierte Substitutionen eingehen. Ihre Aktivität bei dieser Reaktion folgt der Reihe OCO2Me>OBz≫F≫OAc. Die klassische Stereoretention als Folge einer Serie von Inversionen tritt in diesem Fall nicht auf.magnified image
High‐Purity Discrete PEG‐Oligomer Crystals Allow Structural Insight
Authors: French Alister C. , Thompson Amber L. , Davis Benjamin G. 
Published: January 2009

AbstractÜber kurz oder lang: Eine verbesserte Methode zur Synthese von Ethylenglycol (EG)‐Oligomeren eröffnet den Zugang zu 16‐ und 32‐meren, die rein genug für einen mehrfachen Einbau sind, sowie zum bisher längsten (48‐meren) einzelnen EG‐Oligomer. Die hohe Reinheit ermöglichte die ersten Kristallisationen und damit die ersten Einblicke in sekundäre 310‐helicale PEG‐Strukturen.magnified image
Isoprene‐Assisted Radical Coupling of (Co)polymers Prepared by Cobalt‐Mediated Radical Polymerization
Authors: Debuigne Antoine , Jérôme Christine , Detrembleur Christophe 
Published: January 2009

AbstractPolymere en bloc: Die Isopren‐unterstützte radikalische Kupplung (I‐ARC) von Polymeren, die durch Cobalt‐vermittelte radikalische Polymerisation präpariert wurden (siehe Bild), ist die erste effiziente Radikalkupplungsmethode, die nicht auf kurze Ketten beschränkt ist. Die Anwendung der I‐ARC auf AB‐Diblockcopolymere bietet einen direkten Zugang zu neuartigen symmetrischen ABA‐Triblockcopolymeren.magnified image
A Phosphorus Analogue of Bis(η4‐cyclobutadiene)iron(0)
Authors: Wolf Robert , Slootweg J. Chris , Ehlers Andreas W. , Hartl František , de Bruin Bas , Lutz Martin , Spek Anthony L. , Lammertsma Koop 
Published: January 2009

AbstractP macht's möglich: Angesichts der leichten oxidativen Synthese des gezeigten 16‐Elektronen‐Sandwichkomplexes [Fe(η4‐P2C2tBu2)2] ist gut denkbar, dass auch der schwer zu fassende Komplex [Fe(η4‐C4H4)2] mit reinen Kohlenwasserstoffliganden hergestellt werden könnte.magnified image
Stable Aziridinium Salts as Versatile Intermediates: Isolation and Regio‐ and Stereoselective Ring‐Opening and Rearrangement
Authors: Song Hyun A. , Dadwal Mamta , Lee Yeseul , Mick Emily , Chong Hyun‐Soon 
Published: January 2009

AbstractEine nützliche Entdeckung: Aziridiniumbromide wurden zufällig bei der Bromierung von N,N‐dicarboxymethylierten β‐Aminoalkoholen entdeckt. Die regiospezifische Ringöffnung und Umlagerung der isolierten, erstaunlich stabilen Aziridiniumsalze liefert nützliche Moleküle einschließlich C‐funktionalisierter Oxomorpholine und α,β‐ungesättigter Amine.magnified image
Compartmentalization of Chemically Separated Components into Droplets
Authors: Edgar J. Scott , Milne Graham , Zhao Yiqiong , Pabbati Chaitanya P. , Lim David S. W. , Chiu Daniel T. 
Published: January 2009

AbstractMehr als ein Tropfen im Meer: Die Kombination von Kapillarelektrophorese (CE) mit elektroosmotischer Tröpfchenerzeugung ermöglicht die Kompartimentalisierung von durch CE getrennten molekularen Komponenten in einzelnen Tröpfchen (siehe Bild; die grünen Balken repräsentieren die getrennten Analyte). Die tröpfchenweise separierten Banden können auf einem Chip untersucht oder isoliert und separat analysiert werden.magnified image
Water as an Oxygen Source in the Generation of Mononuclear Nonheme Iron(IV) Oxo Complexes
Authors: Lee Yong‐Min , Dhuri Sunder N. , Sawant Sarvesh C. , Cho Jaeheung , Kubo Minoru , Ogura Takashi , Fukuzumi Shunichi , Nam Wonwoo 
Published: January 2009

AbstractMit Cer(IV) als Oxidationsmittel und Wasser als Sauerstoffquelle wurden einkernige Nichthäm‐Eisen(IV)‐Oxo‐Komplexe erhalten. Die in hoher Ausbeute verlaufende Oxygenierung organischer Substrate in diesem System (siehe Schema; Fe grün, O rot, N blau, C grau) wird durch Eisen(II)‐Komplexe katalysiert. Die Quelle des Sauerstoffs in den Eisen(IV)‐Oxo‐Komplexen und den oxygenierten Produkten wurde durch Isotopenmarkierung eindeutig bestimmt.magnified image
Diastereoselective Synthesis of Hexahydropyrrolo[2,1‐b]oxazoles by a Rhodium‐Catalyzed Hydroformylation / Silica‐Promoted Deformylation Sequence
Authors: Vasylyev Maxym , Alper Howard 
Published: January 2009

AbstractFleetingly formyl: A new rhodium‐catalyzed hydroformylation reaction of N‐allyl oxazolidines, carried out under a CO/H2 atmosphere, followed by a diastereoselective deformylative cyclization affords hexahydropyrrolo[2,1‐b]oxazoles in good yields. The reaction proceeds by a unique hydroformylation–deformylation sequence in which the formyl group virtually substitutes for the {CH2O} fragment of the oxazolidine heterocycle.magnified image
Aluminum Bases for the Highly Chemoselective Preparation of Aryl and Heteroaryl Aluminum Compounds
Authors: Wunderlich Stefan H. , Knochel Paul 
Published: January 2009

AbstractSelective CH activation with a series of neutral aluminum trisamide bases led to a wide range of polyfunctional aryl and heteroaryl aluminum reagents. Ester and cyano groups are stable under the reaction conditions for this direct alumination, and donor oxygen substituents are efficient directing groups. High metalation regioselectivities were observed with O,S and N,S heterocycles (see example).magnified image
A Phosphorus Analogue of Bis(η4‐cyclobutadiene)iron(0)
Authors: Wolf Robert , Slootweg J. Chris , Ehlers Andreas W. , Hartl František , de Bruin Bas , Lutz Martin , Spek Anthony L. , Lammertsma Koop 
Published: January 2009

AbstractP makes it possible: The convenient oxidative synthesis of the 16‐electron organophosphorus iron sandwich complex [Fe(η4‐P2C2tBu2)2] (see structure) suggests that the elusive all‐carbon complex [Fe(η4‐C4H4)2] is a viable synthetic target.magnified image
Stable Aziridinium Salts as Versatile Intermediates: Isolation and Regio‐ and Stereoselective Ring‐Opening and Rearrangement
Authors: Song Hyun A. , Dadwal Mamta , Lee Yeseul , Mick Emily , Chong Hyun‐Soon 
Published: January 2009

AbstractRock trapping and exploration: Aziridinium bromide salts were discovered serendipitously during bromination of N,N‐dicarboxymethylated β‐amino alcohols. Regiospecific ring‐opening and rearrangement of the isolated, surprisingly stable aziridinium salts produces useful molecules including C‐functionalized oxomorpholines and α,β‐unsaturated amines.magnified image