bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dynamics in Central European near‐natural Abies‐Fagus forests: Does the mosaic‐cycle approach provide an appropriate model?
Authors: Podlaski Rafat 
Published: January 2008

AbstractQuestion: The mosaic‐cycle concept of forest dynamics dominates in Central Europe. According to this concept intermediate‐scale disturbances only accelerate the forest break‐up under existing cycles of forest development. Is such an approach correct, or should new developmental cycles be elaborated for intermediate‐scale disturbances?Location: Near‐natural Abies alba ‐ Fagus sylvatica forests in the Świétokrzyski National Park in Central Poland. In these forests intermediate‐scale disturbances occurred between 1970 and 1990.Methods: Data were collected twice in areas surrounding 212 permanent sample points (in 1994 and 2004). Two increment cores were taken from 259 sample Abies trees. The effect of intermediate‐scale disturbances on radial increment of Abies was assessed. Probabilities of stand transition during a 10‐year period between individual stages and phases of development of the mixed forest were calculated. The development stages and phases were arranged into hypothetical succession series of successive changes.Results: In 1994 70 stands and in 2004, 47 stands representing stages and phases containing the older generation formed by trees > 100–150 years were found. Also, in 1994 142 and in 2004, 165 stands representing stages and phases containing the younger generations only, formed by trees < 100‐150 years, were recorded. Stages and phases containing only younger generations do not occur in the existing forest development cycle which does not consider the influence of intermediate‐scale disturbances separately. Two developmental cycles, which take into account the presence of the older generation and the younger generations only (under conditions of the occurrence of intermediate‐scale disturbances), are proposed.Conclusion: The mosaic‐cycle concept of forest dynamics can be used to analyse the dynamics of Central European near‐natural mixed‐species forests, but new developmental cycles should be elaborated for intermediate‐scale disturbances.
Communication of positive newborn screening results for sickle cell disease and sickle cell trait: Variation across states
Authors: Kavanagh Patricia L. , Wang C. Jason , Therrell Bradford L. , Sprinz Philippa G. , Bauchner Howard 
Published: January 2008

AbstractIn the US, all states and the District of Columbia have universal newborn screening (NBS) programs for sickle cell disease (SCD), which also identify sickle cell trait (trait). In this project, we surveyed follow‐up coordinators, including one in the District of Columbia and two in Georgia, about protocols for stakeholder notification for SCD and trait. The primary outcomes were total number and type of stakeholder informed of a positive screen. We received 52 completed surveys (100% response). Primary care providers (PCPs) (100%), hematologists (81%), hospitals (73%), and families (40%) were the most commonly notified stakeholders of positive SCD screens, while PCPs (88%), hospitals (63%), and families (37%) were most commonly notified for trait. On average, 3.4 stakeholders were notified for a positive screening for SCD, compared to 2.4 stakeholders for sickle cell trait (P < 0.001). In multivariate analyses for SCD, we found a 2.9% increase in stakeholders notified for each additional year of universal screening mandated in a state (95% CI: 1.4–4.4%). For trait, we found an 8.5% increase in stakeholders notified for each additional follow‐up staff (95% CI: 1.3–15.7%), and a 1.3% increase for each additional percent of black births in the state (95% CI: 0.1–2.5%). Wide variation exists in stakeholder notification by NBS programs of positive screenings for SCD and trait. This variation may alter the effectiveness of NBS programs by location of birth. © 2008 Wiley‐Liss, Inc.
Patient advocacy in newborn screening: Continuities and discontinuities
Authors: Paul Diane B. 
Published: January 2008

AbstractIn the 1960s, patient advocacy groups were instrumental in efforts to mandate state testing of newborns for phenylketonuria (PKU), a recessively inherited disorder of phenylalanine metabolism. Advocacy groups have continued to actively lobby for the expansion of screening to other conditions detectable in newborns and, currently, for states' adoption of a uniform core screening panel. They have also been generally favorable to the offer of fee‐based supplemental screening services. In the early years of newborn screening, groups such as the National Association for Retarded Children (NARC) were strongly imbued with a public‐health ethic. This ethic has apparently eroded over time as the result of both broad social changes and the increasing entanglement of such groups with pharmaceutical and biotechnology companies. A history of newborn screening reveals both continuities and discontinuities in the agendas and funding of patient advocacy groups and in their rhetorical strategies. In particular, it demonstrates that there have always been tensions as well as partnerships with medical and other professionals, although the nature and intensity of the former have been affected by advocacy groups' increasing numbers, resources, and cultural authority. It also illuminates differences that have emerged as advocacy groups have informally allied with industry and adopted new rationales in support of access to testing. © 2008 Wiley‐Liss, Inc.
Nucleic Acid Biosensor for Detection of Human Immunodeficiency Virus Using Aquabis(1,10‐phenanthroline)copper(II) Perchlorate as Electrochemical Indicator
Authors: NIU Shu‐Yan , WANG Shao‐Juan , LI Xue‐Mei 
Published: January 2008

AbstractThe electrochemical behavior of aquabis(1,10‐phenanthroline)copper(II) perchlorate [Cu(H2O)(phen)2]·2ClO4, where phen=1,10‐phenanthroline, on binding to DNA at a glassy carbon electrode (GCE) and in solution, was described. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) results showed that [Cu(H2O)(phen)2]2+ had excellent electrochemical activity on the GCE with a couple of quasi‐reversible redox peaks. The interaction mode between [Cu(H2O)(phen)2]2+ and double‐strand DNA (dsDNA) was identified to be intercalative binding. An electrochemical DNA biosensor was developed with covalent immobilization of human immunodeficiency virus (HIV) probe for single‐strand DNA (ssDNA) on the modified GCE. Numerous factors affecting the probe immobilization, target hybridization, and indicator binding reactions were optimized to maximize the sensitivity and speed of the assay. With this approach, a sequence of the HIV could be quantified over the range from 7.8×10−9 to 3.1×10−7 mol·L−1 with a linear correlation of γ=0.9987 and a detection limit of 1.3×10−9 mol·L−1.
Synthesis and Mesomorphic Behavior of 3‐Alkyl‐2,5‐ bis[p‐(hexa‐2,4‐dienoyloxy)phenyl]‐Thiophene Derivatives
Authors: CHENG Xiao‐Hong , DONG Xing , ZHENG Tao , YE Hui , WEI Guang‐Hui 
Published: January 2008

Abstract3‐Alkyl‐2,5‐bis[p‐(hexa‐2,4‐dienoyloxy)phenyl]‐thiophene derivatives were synthesized by using Kumada coupling and Suzuki coupling reactions as key steps. The thermotropic liquid crystalline behavior of these compounds was investigated by optical polarized microscopy, monotropic nematic mesophases were observed in such compounds.
Further New Cembrane Diterpenes from the Hainan Soft Coral Sarcophyton latum
Authors: YAN Xiao‐Hong , FENG Lin‐Yin , GUO Yue‐Wei 
Published: January 2008

AbstractTwo new cembranoid diterpenes, diepoxysarcophytonene (1) and sarconphytonol (2), were isolated from the Hainan soft coral Sarcophyton latum. Their structures including relative stereochemistry were established by 1D and 2D NMR spectroscopic techniques. Compound 1 showed weak inhibitory activity against COX‐2 in vitro at the concentration of 10−5 µmol·L−1 with the inhibitory rate of 55%.
Total Synthesis of 4′′‐O‐Acetylmananthoside B Part II: Synthesis of the Disaccharide Fragment
Authors: ZHAO Gui‐Long , YU Zhao‐Yun , LI Yan , PANG Li‐Na , WANG Jian‐Wu 
Published: January 2008

AbstractA disaccharide compound, p‐methoxyphenyl 2,3,4‐tri‐O‐benzyl‐β‐L‐arabinopyranosyl‐(1→6)‐2‐O‐benzyl‐3,4‐di‐O‐acetyl‐β‐D‐galactopyranoside (17), was successfully synthesized from two monosaccharides L‐arabinose and D‐galactose and fully characterized. This compound can be used to build a natural product 4″‐O‐acetylmanan thoside B, which was isolated from the leaves and stems of a kind of Vietnamese Acanthaceae Justicia patentiflora.
Synthesis and Properties of N,N′‐Bis(difuroxano [3,4‐b:3′,4′‐d]phenyl)oxalic Amide
Authors: WANG Jian‐Long , LÜ Lian‐Ying , OU Yu‐Xian 
Published: January 2008

AbstractN,N′‐Bis(difuroxano[3,4‐b:3′,4′‐d]phenyl)oxalic amide was synthesized via acylation, nitration, azidation, and pyrolysis‐denitrogenation from the starting materials of oxalyl chloride and 3,5‐dichloroaniline, under mild reaction conditions, with the yields of 81.0%, 82.0%, 86.0% and 81.7% respectively. The title compound and its precursors were characterized by 1H NMR, IR, MS, and elemental analysis. The title compound has a density of 1.92 g·cm−3 by a suspension method, a standard formation enthalpy of 979 kJ·mol−1 calculated by Gaussian programs, a detonation velocity of 8.17 km·s−1, and a detonation pressure of 31 GPa obtained by Kamlet Equation. The thermal decomposition reactions of the title compound at different heating rates were tested by differential scanning calorimetry (DSC). The kinetics parameters of the pyrolysis of the compound were calculated by Kissinger's method. The values of apparent activation energy (Ea) and pre‐exponential constant (A) were 226.7 kJ·mol−1 and 1023.17 s−1 respectively. It was presupposed that N,N′‐bis(difuroxano[3,4‐b:3′,4′‐d]phenyl)oxalic amide would be a promising high energetic explosive with low sensitivity.
Theoretical Studies on the One‐ and Two‐Photon Absorption Properties of Double‐bis(styryl)benzene Derivatives
Authors: HAN De‐Ming , FENG Ji‐Kang , REN Ai‐Min , SHANG Xiao‐Hong , ZHANG Xiang‐Biao , MA Yu‐Guang , HE Feng 
Published: January 2008

AbstractTwo series of bis(styryl)benzene derivatives (BSBD), namely the single‐BSBD and the double‐BSBD, were investigated. The equilibrium geometries and electronic structures were obtained by using the density functional theory B3LYP and 6‐31G basis set. In succession, the one‐ and two‐photon absorption properties of all the molecules were studied theoretically with a ZINDO‐SOS (sum‐over‐states) method in detail. It can be seen that the double‐BSBDs have larger two‐photon absorption (TPA) cross sections in the visible‐IR range than the corresponding single‐BSBDs, demonstrating that increasing the molecular dimension is a very effective method to enhance the values of the TPA cross sections. On the other hand, it can be also noticed that the values of the TPA cross sections are correlative with the ability of donating (accepting) electrons of the terminal substituent groups R [N(CH3)2, CH3, H and CF3] in these molecules. That is, the intramolecular charge transfer is also a factor for the enhancement of the TPA efficiency. To sum up, the idea of increasing the molecular dimension to enhance the TPA cross section value is a helpful direction to explore better TPA materials for practical applications. And the double‐BSBD molecules are promising TPA materials for the further investigation from the standpoint of the high transparency and the larger TPA cross sections.
Effect of the Carboxylate Salt on the CON Bond Homolysis of SG1‐Based Alkoxyamines
Authors: Bertin Denis , Gigmes Didier , Marque Sylvain R. A. , Siri Didier , Tordo Paul , Trappo Gregory 
Published: January 2008

AbstractAlkoxyamines and persistent nitroxides are important regulators of the nitroxide mediated radical polymerization (NMP). Since the polymerization time decreases with increasing values of the homolysis rate constant (kd) for the CON bond between the polymer chain and the nitroxide moiety, the factors influencing kd are of considerable interest. Environmentally friendly polymerization methods, such as NMP in emulsion medium, have now been developed. The success of the polymerization depends not only on the strength of the CON bond but also on the solubility of the initiator/controller alkoxyamines, which control the nucleation. Various salts of SG1‐based alkoxyamines (S+−OOCCMeH‐SG1) labelled 1 a–f, where S+=Li+ (a), Na+ (b), K+ (c), nBu3HN+ (d), NH4+ (e), and nBu4N+ (f) are prepared, all of which are soluble in most organic solvents (e.g. pentane, dichlomethane, benzene, ethanol, etc.) as well as in water. Their kd values, which are measured in tert‐butylbenzene, reveal unexpected behaviors depending on the diastereoisomers. For the RR/SS diatereoisomers (i.e. slowly homolyzing isomers), kd was not found to be sensitive to any of the salts, whereas for the RS/SR diastereoisomers (i.e. quickly homolyzing isomers), kd is observed to decrease to a greater or lesser extent depending on the type of salt. The conformations of the diastereoisomers of several salts are determined by means of DFT calculations, and the orbital interactions are studied by natural bond orbital (NBO) analysis.
Monogenic migraine syndromes highlight novel drug targets
Authors: Gargus J. Jay , Shih Cindy H. 
Published: January 2008

AbstractIn the post‐genomic era, the paradigm for drug discovery has changed, as every gene may become a potential target. Genetic diseases provide a special window into gene target selection. This approach is being applied to migraine making use of the genes and mutations causing familial hemiplegic migraine (FHM). FHM is caused by missense mutations in CACNA1A, altering a neuronal P/Q Ca2+ channel, in ATP1A2, altering α2 Na,K‐ATPase, and in SCN1A, altering a neuronal sodium channel. These genes provide insights into migraine pathogenesis that likely extend to other forms of migraine as well. Since the three FHM genes are only co‐expressed in neurons, FHM is a neuronal, not a vascular, disease and because they all encode ion transport proteins, FHM is a neuronal channelopathy—meaning meta‐stable neuronal hyperexcitability is the substrate of migraine, much as it is for genetic epilepsy syndromes. This similarity is reinforced, since different mutations of all three FHM genes can produce seizure syndromes. This has implications for drug discovery in that seizure medications already known to modulate the FHM channel mechanisms warrant more targeted development, and that drugs targeted to vascular headaches, such as the historically effective triptans, or experimental botulinum toxin, may well work by similar nonvascular mechanisms. Finally, in model neurogenetic systems such as Caenorhabditis elegans, the FHM genes also provide both a comprehensive means to discover all genes involved in their signaling pathway—genes potentially involved in common forms of the disease, and an in vivo whole animal means to screen rapidly for novel therapeutics. Drug Dev Res 68:432–440, 2007. © 2008 Wiley‐Liss, Inc.
Evidence‐based medicine in migraine prophylactic treatment in childhood and adolescence
Authors: Balottin Umberto , Ferri Matteo , Termine Cristiano 
Published: January 2008

AbstractMigraine is a common and disabling disorder, affecting children, adolescents, and adults. Prophylactic therapy should be considered when specific clinical conditions are fulfilled. Its goal is to reduce the frequency and duration of the attacks as well as the severity of pain, thus allowing patients to regain routine activities and ameliorating their quality of life. Using the principles of evidence‐based medicine, a review of available published data on the efficacy and safety of prophylactic treatments for migraine in children and adolescents is presented. Currently, only flunarizine and psychologically based interventions (e.g., relaxation training, biofeedback, and psychotherapeutic techniques) may be effective in migraine prophylaxis in children and adolescents. Owing to the paucity of evidence, there is a need for large, controlled, randomized, and masked trials. Clinical researchers should consider that migraine, especially in childhood and adolescence, is a complex condition, resulting from the interaction between biological, psychological, and environmental factors. Specific events, constitutional predisposition, individual and environmental‐emotional dynamics can play a significant role in the genesis and evolution of pain. Age‐related characteristics such as prevalence, diagnosis, quality of life, and therapy should be considered designing future studies. Drug Dev Res 68:461–468, 2007. © 2008 Wiley‐Liss, Inc.
Supramolecular Aggregates in Fluid Phases: Mesomorphic ortho‐Palladated Complexes with Substituted Crown Ethers and Their Potassium Adducts
Authors: Coco Silverio , Cordovilla Carlos , Espinet Pablo , Gallani Jean‐Louis , Guillon Daniel , Donnio Bertrand 
Published: January 2008

AbstractNew imines (HL) containing substituted dibenzo‐18‐crown‐6‐ethers and their dinuclear ortho‐palladated complexes, [Pd(μ‐X)L]2 (X– = CH3COO–, Cl–), have been prepared. The free imine ligands are not liquid crystals, but the palladium complexes, including acetato‐bridged derivatives, show liquid‐crystal properties. The mesomorphic palladium complexes bear six or eight alkoxy chains. Although a columnar arrangement of these chains might be expected, a smectic arrangement is in fact preferred for half of the metallomesogens prepared, which show a smectic C mesophase. Complexation with potassium produces a significant increase in the mesophase range and stability. Moreover, both the free imines and the corresponding liquid‐crystalline ortho‐palladated complexes form stable Langmuir films at the air–water interface.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
A Pair of Coordination Donor–Acceptor Ensembles for the Detection of Tartrate in Aqueous Media
Authors: Koo Chi‐Kin , Chow Cheuk‐Fai , Chiu Brenda Ka‐Wen , Lei Ngai‐Yu , Lam Michael Hon‐Wah , Wong Wai‐Yeung 
Published: January 2008

AbstractA chemosensing approach utilizing a pair of heterodimetallic chemodosimetric ensembles of different analyte selectivity for the specific detection of targeted analytes in aqueousmedia was developed. Two new trinuclear, heterodimetallic donor–acceptor complexes, {Ru(tBubpy)(CN)4[Cu(cyclen)]2}(ClO4)2 ([Ru‐Cu]) and {Ru(tBubpy)(CN)4[Ni(cyclen)]2}(ClO4)2([Ru‐Ni]), where tBubpy = 4,4′‐di‐tert‐butyl‐2,2′‐bipyridine and cyclen = 1,4,7,10‐tetraazacyclododecane, have been synthesized and characterized. Their formation constants from K2[Ru(tBubpy)(CN)4] and [Cu(cyclen)](ClO4)2 and [Ni(cyclen)](ClO4)2 were measured to be 5.54 × 106 ([Ru‐Cu]) and 1.24 × 107 M–2 ([Ru‐Ni]), respectively, at 298 K. Luminescent chemodosimetric responses of these two ensembles towards various anionic analytes in neat aqueous buffer at pH 7.0 were evaluated. While each of these two ensembles showed relatively low analyte specificity, they can be used together to manifest a chemosensing XOR logic output for the specific detection of tartrate. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Synthesis and Structural Characterisation of cis‐ and trans‐[(hppH)2PtCl2], [(hppH)3­PtCl]+Cl– and Some New Salts of the [hppH2]+ Cation (hppH = 1,3,4,6,7,8‐Hexahydro‐2H‐pyrimido[1,2‐a]pyrimidine): The Importance of Hydrogen Bonding
Authors: Wild Ute , Roquette Pascal , Kaifer Elisabeth , Mautz Jürgen , Hübner Olaf , Wadepohl Hubert , Himmel Hans‐Jörg 
Published: January 2008

AbstractThe reaction between the guanidine derivative hppH (hppH = 1,3,4,6,7,8‐hexahydro‐2H‐pyrimido[1,2‐a]pyrimidine) and K2PtCl4 in H2O affords the salt [hppH2]2[PtCl4], which reacts further with Li(hpp) in thf to give cis‐[(hppH)2PtCl2]. The corresponding trans isomer is obtained from the reaction between [(dmso)2PtCl2] and hppH. hppH easily replaces another chlorido ligand to give [(hppH)3PtCl]+Cl–. [hppH2]Cl is formed as a hygroscopic side‐product in the synthesis of [(hppH)2PtCl2] and takes up 1 equiv. of H2O to give [hppH2]Cl·H2O. We report the crystal structures of cis‐ and trans‐[(hppH)2PtCl2], [(hppH)3PtCl]+Cl– and some salts of the [hppH2]+ cation, namely [hppH2]2[PtCl4] and the Pt‐free salts [hppH2][BPh4], [hppH2]Cl and [hppH2]Cl·H2O, which have an increasing degree of directed intermolecular hydrogen contacts. The crystal structure of [hppH2]Cl·H2O features helical chains of Cl–·H2O connected via [hppH2]+ cations. The effects of hydrogen bonding on the structures of these compounds in the solid state are discussed. Finally, quantum chemical calculations provide further insight into the structures and properties of some of these compounds. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Cobalt(III) Complexes of a Tripodal Ligand Containing Three Imidazole Groups: Properties and Structures of Racemic and Optically Active Species
Authors: Nakamura Hirofumi , Fujii Megumi , Sunatsuki Yukinari , Kojima Masaaki , Matsumoto Naohide 
Published: January 2008

AbstractThe complex [Co(H3L)](ClO4)3·H2O (1), where H3L {tris[2‐(4‐imidazoylmethylideneamino)ethyl]amine} is a tripodal ligand obtained by condensation of tris(2‐aminoethyl)amine and 4‐formylimidazole in a 1:3 molar ratio, was synthesized and optically resolved by fractional crystallization of the diastereomeric salt with [Sb2{(R,R)‐tart}2]2– [(R,R)‐tart = (2R,3R)‐tartrate(4–) ion]. From the less soluble part, Λ‐[Co(H2L)][Sb2{(R,R)‐tart}2]·4H2O (2) was isolated. Starting from 2, two optically active complexes, Λ‐[Co(H3L)](ClO4)3·1.5H2O (Λ‐1) and Λ‐[Co(L)] (Λ‐3), were obtained. The crystal structures of these complexes are compared with those of the racemic structures. Λ‐1 shows an unusually strong circular dichroism (λ = 488 nm, Δϵ = –7.74 M–1 cm–1) in the first d–d absorption band region. The effects of deprotonation–reprotonation of the uncoordinated imidazole NH groups of Λ‐[Co(H3L)]3+ on the UV/Vis and CD spectra and on the cyclic voltammograms were studied in methanol. Although the deprotonation–reprotonation reactions are reversible, the redox couple for the completely deprotonated species [CoIII/II(L)]0/– is not observed. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Synthesis and Characterization of Cyclopropylpolyketides: A Combined Experimental and Theoretical Study
Authors: Rahn Thomas , Jiao Haijun , Baumann Wolfgang , Spannenberg Anke , Langer Peter 
Published: January 2008

AbstractThe first open‐chain cyclopropylpolyketides were prepared and characterized by experimental and computational methods. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Scaffolds based on hyaluronan crosslinked with a polyaminoacid: Novel candidates for tissue engineering application
Authors: Pitarresi G. , Palumbo F. S. , Cavallaro G. , Faré S. , Giammona G. 
Published: January 2008

AbstractNew porous scaffolds, with a suitable hydrolytic and enzymatic degradation, useful for tissue engineering applications have been obtained by a carbodiimide mediated reaction between hyaluronan (HA) and a synthetic polymer with a polyaminoacid structure such as α,β‐polyaspartylhydrazide (PAHy). Scaffolds with a different molar ratio between PAHy repeating units and HA repeating units have been prepared and characterized from a chemical and physicochemical point of view. Tests of indirect and direct cytotoxicity, cell adhesion, and spreading on these biomaterials have been performed by using murine L929 fibroblasts. The new biomaterials showed a good cell compatibility and ability to allow cell migration into the scaffolds as well as spreading on their surface. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2008