bluuebunny/crossref_metadata_2025 huggingface dataset:
Bernauer′s Bands
Authors: Shtukenberg Alexander , Gunn Erica , Gazzano Massimo , Freudenthal John , Camp Eric , Sours Ryan , Rosseeva Elena , Kahr Bart
Published: March 2011

Ferdinand Bernauer proposed in his monograph, “Gedrillte” Kristalle(1929), that a great number of simple, crystalline substances grow from solution or from the melt as polycrystalline spherulites with helically twisting radii that give rise to distinct bull′s‐eye patterns of concentric optical bands between crossed polarizers. The idea that many common molecular crystals can be induced to grow as mesoscale helices is a remarkable proposition poorly grounded in theories of polycrystalline pattern formation. Recent reinvestigation of one of the systems Bernauer described revealed that rhythmic precipitation in the absence of helical twisting accounted for modulated optical properties [Gunn, E. et al.J. Am. Chem. Soc.2006,128, 14 234–14 235]. Herein, the Bernauer hypothesis is re‐examined in detail for three substances described in “Gedrillte” Kristalle, potassium dichromate, hippuric acid, and tetraphenyl lead, using contemporary methods of analysis not available to Bernauer, including micro‐focus X‐ray diffraction, electron microscopy, and Mueller matrix imaging polarimetry. Potassium dichromate is shown to fall in the class of rhythmic precipitates of undistorted crystallites, while hippuric acid spherulites are well described as helical fibrils. Tetraphenyl lead spherulites grow by twistingandrhythmic precipitation. The behavior of tetraphenyl lead is likely typical of many substances in “Gedrillte” Kristalle. Rhythmic precipitation and helical twisting often coexist, complicating optical analyses and presenting Bernauer with difficulties in the characterization and classification of the objects of his interest.
Unravelling Complex Spectra of a Simple Molecule: REMPI Study of the 420 nm Band System of KRb
Authors: Lee Yonghoon , Yoon Youngjee , Kim Jin‐Tae , Lee Sungyul , Kim Bongsoo
Published: March 2011

Complex spectra of the KRb 420 nm system are analyzed by mass‐resolved resonance enhanced two‐photon ionization in a cold molecular beam. Vibronic structures of three singlet–singlet (4 1Π, 7 1Σ+, and 5 1Π←X 1Σ+) transitions were identified for the first time. By comparing with highly accurate ab initio calculations, we assigned the singlet excited electronic states, and determined their electronic term values and vibrational constants. Weak singlet–triplet transitions were observed and identified as the 5 3Π (0+)←X 1Σ+ transitions by the homogeneous perturbation selection rule.
NMR J‐Coupling Constants in Cisplatin Derivatives Studied by Molecular Dynamics and Relativistic DFT
Authors: Sutter Kiplangat , Truflandier Lionel A. , Autschbach Jochen
Published: March 2011

Solvent effects on J(195Pt15N) one‐bond nuclear spin–spin coupling constants (JPtN) of cisplatin [cis‐diamminedichloroplatinum(II)] and three cisplatin derivatives are investigated using a combination of density functional theory (DFT) based ab initio molecular dynamics (aiMD) and all‐electron relativistic DFT NMR calculations employing the two‐component relativistic zeroth‐order regular approximation (ZORA). Good agreement with experiment is obtained when explicit solvent molecules are considered and when the computations are performed with a hybrid functional. Spin–orbit coupling causes only small effects on JPtN. Key factors contributing to the magnitude of coupling constants are elucidated, with the most significant being the presence of solvent as well as the quality of the density functional and basis set combination. The solvent effects are of the same magnitude as JPtN calculated for gas‐phase geometries. However, the trends of JPtN among the complexes are already present in the gas phase. Results obtained with a continuum solvent model agree quite well with the aiMD results, provided that the Pt solvent‐accessible radius is carefully chosen. The aiMD results support the existence of a partial hydrogen‐bond‐like inverse‐hydration‐type interaction affording a weak 1J(Pt⋅⋅⋅Hw) coupling between the complexes and the coordinating water molecule.
Additive induced morphology changes of nano‐crystalline SrWO4
Authors: Tian Guangru , Sun Sixiu
Published: March 2011

Large‐scale high‐quality SrWO4 nanocrystals have been synthesized in aqueous solutions under mild hydrothermal conditions with citrate as a simple additive. The crystals undergo an interesting 0‐D to 1‐D and to 0‐D morphology changes and have been characterized by X‐ray diffraction (XRD) and transmission electron microscopy (TEM) techniques. The results showed that the experimental parameters had great influences on the shape evolution of products. The adjustment of these parameters such as the addition of the citrate and hydrothermal reaction conditions, can lead to obvious morphology changes of products, and the growth mechanism has been proposed. Room‐temperature photoluminescence indicated that the as‐prepared SrWO4 nanocrystals had strong emission peaks at about 434 and 506 nm, respectively. This facile route could be employed to synthesize more promising nanomaterials with interesting self‐assembly structures. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Metastable zone width for secondary nucleation and secondary nucleation inside the metastable zone
Authors: Khaddour I. , Rocha F.
Published: March 2011

This study presents an evaluation of a new method, called zero growth activation free energy, used to determine the metastable zone width for the secondary nucleation case. It predicts the metastable zone width with a maximum error of 5‐10%. Estimation of the metastable zone width for different isothermal crystallization conditions can be modeled according to a chosen reference set of growth experiments carried out in the volume diffusion regime at different initial supersaturations, using seed crystals of a certain characteristic size. Moreover, the activation free energy of the secondary nucleation was estimated. The role of the enthalpy of immersion in the formation of secondary nucleation events inside the metastable zone was pointed out, as well as its effect in causing extra‐fast growth rate. Furthermore, sucrose crystal surface free energy was estimated. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Local nanotailoring of polymeric photophysics by Au nanoparticles implantation
Authors: Suárez López I. , Rajendran S. K. , Corbelli G. , Ghisleri C. , Milani P. , Ravagnan L. , Pasini M. , Stagira S. , Virgili T.
Published: March 2011

We studied the excitation dynamics and the photoluminescence spectra in polymeric matrix implanted with metallic nanoparticles. A supersonic beam of gold nanoparticles (sizes 2‐7 nm) was generated by using a Pulsed Microplasma Cluster Source (PMCS). The nanoparticles were implanted in a thin polyfluorene film (thickness around 100 nm) spin coated on a PMMA (poly methyl methacrilate) substrate. We performed photoluminescence and pump‐probe measurements using a Ti:Sapphire amplified laser system, the excitation pump pulse was centered at 400 nm with a 150 fs time duration. The experimental results show a suppression of the amplified spontaneous emission from the polyfluorene (PFO) film due to the presence of the implanted nanoparticles. The transient transmission spectra revealed the presence of a photoinduced absorption band due to the nanoparticles which overlaps with the stimulated emission band from the PFO, hindering the possibility of having amplified spontaneous emission. These results demonstrate the possibility of a local nanotailoring of the polymeric photophysics. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Stacking faults in semi‐polar 6H‐SiC single crystals
Authors: Gao Y. Q. , Hu X. B. , Xu X. G. , Chen X. F. , Peng Y. , Song S. , Jiang M. H. , Huang W. X.
Published: March 2011

6H‐SiC single crystals have been successfully grown on (1015) plane seed by sublimation method. High density stacking faults (SFs) were observed by transmission synchrotron radiation X‐ray topography. Based on the invisibility criteria of stacking faults, the displacement vectors of most SFs were determined to be the type of 1/6[1120]. Laser scanning confocal microscopy (LSCM) was used to observe the etching morphology of (0115) wafer. The etching steps of SFs were found and their density decreased from 3.6×103 cm‐1 to 2.0×102 cm‐1 along the <0001> projection direction. The inclination angles of the SFs etching step plane to (10‐15) plane were measured by line scanning of LSCM. It was found that the inclination angles decreased from 20° to 10° along the <0001> projection direction. Different etching characteristics of SFs along radial direction of 6H‐SiC (1015) wafer should be attributed to different displacement vectors and different stacking fault energies for these stacking faults. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Diagnostic pitfalls in cytological diagnosis of subcutaneous fungal infection in renal transplant recipients
Authors: Jaiswal Sushila , Vij Mukul , Prasad Narayan , Kaul Anupama , Marak Rungmei S. K. , Pandey Rakesh
Published: March 2011

Renal transplant recipients (RTRs) are at increased risk of the development of a variety of skin infections that can result from graft‐preserving immuno‐suppressive therapy. In this study, we aimed to determine cytomorphological findings of fungal subcutaneous swelling in seven RTRs and to analyze diagnostic pitfalls in fungal cytology. A retrospective review of fine needle aspiration cytology (FNAC) smears of subcutaneous swelling with positive fungal elements in RTRs from 2008 to 2010 was performed. We had seven cases (all males; age range, 34–58 years, mean, 46.3 years). The time interval between the renal transplantation and appearance of swelling ranged from 8 to 19 months (mean, 13.4 months). The swelling was located on lower limb (six cases) and arm (one case). The lesion was solitary (six cases) and multiple (one case). The cytology of aspirated material showed branched septate fungal hyphae in six cases. These were well delineated on Periodic acid schiffs (PAS) and chromic silver methenamine (CSM) stains. One case showed presence of faint, thin walled, broad ribbon like hyphae. Culture of aspirated material was performed in four cases which grew phaeohyphomycosis in all. Histology of excised tissue showed numerous septate, branched, pigmented fungal elements suggestive of pheohyphomycosis in four cases and broad ribbon hyphae suggestive of zygomycosis in one case. All of our cases responded well with anti‐fungal treatment. Fungal infection can manifest as subcutaneous swelling in RTRs. It is often severe, rapidly progressive and difficult to diagnose. FNAC is an important diagnostic tool which is simple, cost effective and rapid method. Diagn. Cytopathol. 2012. © 2011 Wiley Periodicals, Inc.
Primary effusion lymphoma involving the cerebrospinal fluid
Authors: Moatamed Neda A. , Song Sophie X. , Apple Sophia K. , Said Jonathan W.
Published: March 2011

Primary effusion lymphoma or body cavity based lymphoma is a form of large B‐cell lymphoma which usually presents as serous effusions without detectable tumor masses. It is universally associated with human herpesvirus‐8 also known as Kaposi sarcoma herpesvirus. This condition, so far, has been reported in the body cavity effusions that include pleura, peritoneum, and pericardium. We report a case of primary effusion lymphoma which has involved the cerebrospinal fluid. To our knowledge, this is the first case of PEL reported in the cerebrospinal fluid. Diagn.Cytopathol. 2012. © 2011 Wiley‐ Liss, Inc.
Gallium and Indium β‐Diketonate Complexes: AACVD of [In(thd)3] and the Attempted Synthesis of Gallium and Indium Bis(β‐diketonates)
Authors: Pugh David , Bloor Leanne G. , Sathasivam Sanjayan , Parkin Ivan P. , Carmalt Claire J.
Published: March 2011

Aerosol‐assisted chemical vapour deposition (AACVD) of a suspension of [In(thd)3] (thd = 2,2,6,6‐tetramethylheptane‐3,5‐dionate) in CH2Cl2 at 450 °C afforded thin crystalline films of indium oxide. The films were analyzed by scanning electron microscopy (SEM), glancing angle X‐ray diffraction (XRD) and energy dispersive analysis of X‐rays (EDX). Efforts to grow thicker films were hampered by the poor solubility of [In(thd)3], so the synthesis of heteroleptic compounds of the type [M(bdk)2X] (M = Ga, In; bdk = β‐diketonate; X = chloride, hydride, methyl) was attempted such that the solubility could be improved by tuning the ligands surrounding the metal centre. Reaction of stoichiometric amounts of β‐diketones [Hthd and 2,4‐pentanedione (acetylacetone, Hacac)] with Lewis base‐stabilized adducts of GaH3 resulted only in the isolation of the homoleptic gallium tris(β‐diketonate) compounds [Ga(bdk)3], instead of the expected heteroleptic gallium bis(β‐diketonate) hydride, [GaH(bdk)2]. An unexpected reduction of Hthd to 2,2,6,6‐tetramethylheptane‐3,5‐diol was also observed. Other attempted syntheses of gallium bis(β‐diketonate) compounds also resulted in the isolation of homoleptic [Ga(bdk)3] complexes and similar results were obtained for indium. The compounds were characterised by 1H NMR spectroscopy, mass spectrometry and elemental analysis and the structures of [In(thd)3] and 2,2,6,6‐tetramethylheptane‐3,5‐diol were determined by X‐ray crystallography.
Facile Oxidative Addition of Organic Halides to Heteroleptic and Homoleptic Pd0–N‐Heterocyclic Carbene Complexes
Authors: Lee Jung‐Hyun , Jeon Hyeong‐Tak , Kim Yong‐Joo , Lee Kyung‐Eun , Ok Jang Young , Lee Soon W.
Published: March 2011

Novel heteroleptic Pd0 complexes with an N‐heterocyclic carbene (NHC) ligand [(Me3P)Pd(NHC)] (NHC = IPr, 1; SIPr, 2) were obtained from [Pd(CH2=CHPh)(PMe3)2] and an equivalent of NHC [NHC = 1,3‐bis(2,6‐diisopropylphenyl)imidazol‐2‐ylidene (IPr) or 1,3‐bis(2,6‐diisopropylphenyl)‐4,5‐dihydroimidazol‐2‐ylidene (SIPr)]. Further treatments of complexes 1 and 2 with an additional equimolar NHCafforded the corresponding bis(NHC)–Pd0 complexes [Pd(NHC)2] (NHC = IPr, 3; SIPr, 4). Complexes 1–4 readily reacted with dichloromethane or chloroform to give C–Cl oxidative addition products. In addition, the reactivity of complex 2 toward other organic halides such as bromobenzene, trans‐1,2‐dichloroethylene, and 5,5′‐dibromo‐2,2′‐bithiophene to produce the corresponding oxidative addition products was investigated. Finally, the ligand replacement of complex 1 with a chelating phosphane was examined.
Radical Coordination Chemistry and Its Relevance to Metal‐Mediated Radical Polymerization
Authors: Poli Rinaldo
Published: March 2011

The reactions engaged by organic radicals with transition‐metal complexes are reviewed with a particular focus on how they can interplay with and affect the results of radical polymerization. Radicals can either add to a metal centre to establish metal–carbon bonds, abstract an atom or group, be abstracted by an atom or group, undergo associative exchange, transfer a β‐H atom or add to existing ligands in the metal coordination sphere. Reversibility is key for certain controlled polymerization methods. The various ways in which metal complexes can play a role in radical polymerization lead to atom‐transfer radical polymerization (ATRP), organometallic‐mediated radical polymerization by either reversible termination (OMRP‐RT) or degenerative transfer (OMRP‐DT) and chain‐transfer‐catalysed radical polymerization (CTCRP).
Synthesis and IR Spectroelectrochemical Studies of a [60]Fulleropyrrolidine‐(tricarbonyl)chromium Complex: Probing C60 Redox States by IR Spectroscopy
Authors: Andersson Claes‐Henrik , Berggren Gustav , Ott Sascha , Grennberg Helena
Published: March 2011

The synthesis of a new fulleropyrrolidine‐(tricarbonyl)chromium complex: 1‐methyl‐2‐(4‐methoxyphenyl)‐3,4‐[60]fulleropyrrolidine‐(tricarbonyl)chromium is described together with its characterization by IR, NMR and cyclic voltammetry. IR spectro‐electrochemistry has been used to probe the redox level of the fullerene derivative via the relative position of the vibrational bands of the CO ligands, which are sensitive to the electronic state of the complex. Other strategies to incorporate a tricarbonylchromium moiety to fullerene C60 are also briefly discussed and evaluated.
Synthesis of Cyclopropane‐Containing Phosphorus Compounds by Radical Coupling of Butenylindium with Iodo Phosphorus Compounds
Authors: Kiyokawa Kensuke , Suzuki Itaru , Yasuda Makoto , Baba Akio
Published: March 2011

The radical coupling of α‐ or β‐iodo phosphorus compounds such as iodo phosphonate, iodo phosphane oxide, and iodo phosphonothioate with butenylindium species, prepared by transmetalation between a (cyclopropylmethyl)stannane and InBr3, afforded the corresponding cyclopropylmethylated products. The radical reaction was initiated by the radical species generated from butenylindium assisted by a small amount of oxygen. Butenylindium works not only as a cyclopropylmethylating reagent, but also as a radical initiator. For successful coupling, a tin/indium transmetalation was used, where it was important for the tin halide by‐product to be inert to the reaction system. In addition, the transmetalation of a (cyclopropylmethyl)stannane and InBr3 provided the dibutenylindium bromide as a single product, which smoothly coupled with the unstable phosphonyl radical species from the iodo phosphorus compound. A photochemical method (UV irradiation) was also applied and accelerated the coupling reaction. The cyclopropylmethylated phosphonate produced was a good intermediate in the Horner–Wadsworth–Emmons reaction and gave functionalized olefins bearing the cyclopropane moiety.
Contorted Conformations of 1,4‐Butylidenedipyridinium and 1,10‐Decylidenedipyridinium Cationic Guests in a Cucurbit[8]uril Host
Authors: Xiao Xin , Wang Qian , Yu Yi‐Hua , Xiao Zhi‐You , Tao Zhu , Xue Sai‐Feng , Zhu Qian‐Jiang , Liu Jing‐Xin , Liu Xin‐Hua
Published: March 2011

1,4‐Butylidenedipyridinium (C4DP2+) and 1,10‐decylidenedipyridinium (C10DP2+) cationic guests form highly stable 1:1 inclusion complexes in aqueous solution with a cucurbit[8]uril (Q[8]) host. Single‐crystal structure analysis of the inclusion complexes revealed that the alkyl chain of the CnDP2+ (n = 4, 10) cationic guest adopts an unconventional contorted conformation, which is attributed to favorable host–guest interactions (including charge–dipole and hydrophobic interactions) when bound within the cavity of the Q[8] host. Moreover, their crystal structures suggest that the alkyl chain and the aromatic group can be encapsulated into the Q[8] host simultaneously, and the alkyl chain is more favorably encapsulated into the Q[8] host than the aromatic group.
A Clean, Highly Efficient and One‐Pot Green Synthesis of Aryl/Alkyl/Heteroaryl‐Substituted Bis(6‐amino‐1,3‐dimethyluracil‐5‐yl)methanes in Water
Authors: Das Subrata , Thakur Ashim Jyoti
Published: March 2011

A highly efficient green synthesis of aryl/alkyl/heteroaryl‐substituted bis(6‐amino‐1,3‐dimethyluracil‐5‐yl)methanes by the condensation of 6‐amino‐1,3‐dimethyluracil with aldehydes (aromatic, aliphatic and heterocyclic) in water at room temperature is described. No dehydrating agent, heat, catalyst, surfactant or additive was used. The structures of the compounds were established by spectroscopic methods and single‐crystal X‐ray crystallography.
Practical Syntheses of (2S)‐R207910 and (2R)‐R207910
Authors: Chandrasekhar Srivari , Babu G. S. Kiran , Mohapatra Debendra K.
Published: March 2011

Concise and practical syntheses of (2S)‐R207910 (3a) and (2R)‐R207910 (3b) have been achieved in high overall yield of 12 % in 10 steps for each isomer starting from a known intermediate following Sharpless asymmetric epoxidation, regioselective epoxide opening, modified allylzinc bromide addition as key reactions.
Gold‐Catalyzed Reactions of 2‐C‐Branched Carbohydrates: Mild Glycosidations and Selective Anomerizations
Authors: Vidadala Srinivasa Rao , Pimpalpalle Tukaram M. , Linker Torsten , Hotha Srinivas
Published: March 2011

2‐C‐branched methyl glycosides react with various alcohols under gold catalysis to transglycosylated products. The method is applicable for the convenient synthesis of disaccharides. Without nucleophile a selective anomerization occurs, giving first access to α‐configured 2‐C‐nitromethyl glycosides. The results are interesting for the mechanism of gold‐catalyzed glycosidations.
Micronuclei and other nuclear abnormalities in mussels (Mytilus galloprovincialis) as biomarkers of cyto‐genotoxic pollution in mediterranean waters
Authors: Fernández Beatriz , Campillo Juan Antonio , Martínez‐Gómez Concepción , Benedicto José
Published: March 2011

Environmental genotoxicity and cytotoxicity along the Spanish Mediterranean coast was investigated through the determination of levels of micronuclei (MN) and other nuclear abnormalities (NAs) such as nuclear buds (NB) and binucleated cells (BN) in gills of wild mussels, Mytilus galloprovincialis, from 17 study sites. The results obtained were studied in relation to the exposure to main pollutants (metals, PAHs, PCBs and DDTs), gill antioxidant enzyme activities and environmental variables (temperature and salinity). The highest MN and NB levels were found in mussels from metal‐polluted sites, such as Cartagena (MN: 11.6‰, NB: 4.6‰) and Portman (MN: 8.0‰, NB: 3.5‰), where genotoxicity seemed to be related to the oxidative stress generated by exposure to metals. High frequencies of MN and NB in mussels from Algeciras 1 (MN: 8.6‰, NB: 4‰) and of MN (7.2‰) in mussels from Manilva also indicated genotoxicity, though not attributable to the pollutants analysed. In contrast, MN levels at sites highly polluted by organic contaminants such as Barcelona, Vallcarca, Tarragona and Valencia, were lower than expected (ranging from 3.8 to 5.8‰). On the other hand, evidences of cytotoxicity indicated by the high frequencies of BN found in mussels from Vallcarca, Barcelona, and Cartagena (3.9, 3.4, and 2.3‰, respectively) appeared to be specifically related to the accumulation of organic pollutants. Positive correlations found between MN and NB frequencies, and also between both NAs and water temperature, suggested that they were related genotoxic events, and that this environmental factor is able to influence their levels and has to be taken into account in the application of these biomarkers in field studies. Environ. Mol. Mutagen., 2011. © 2011 Wiley‐Liss, Inc.
Biomonitoring of rural workers exposed to a complex mixture of pesticides in the municipalities of Tianguá and Ubajara (Ceará state, Brazil): Genotoxic and cytogenetic studies
Authors: Paiva Jean C.G. , Cabral Igor O. , Soares Bruno M. , Sombra Carla M.L. , Ferreira José R.O. , Moraes Manoel O. , Cavalcanti Bruno C. , Pessoa Cláudia
Published: March 2011

In recent years, the use of pesticides in agriculture has been steadily increasing, and associations between exposure to agricultural chemicals and DNA damage and cancer have been reported. Brazil is one of the world leaders in pesticide use; however, studies that evaluate the impact of pesticide exposure on cancer incidence and mortality are very scarce in the Brazilian population. The alkaline comet assay and the chromosome aberration (CA) test were used to evaluate primary DNA damage in the peripheral blood lymphocytes of workers exposed to a complex mixture of pesticides in two small rural communities in the municipalities of Tianguá and Ubajara, located in the western part of Ceará State (Northeast Brazil), which are among the largest agricultural areas of the state. The comet assay showed that the damage index and damage frequency observed in the exposed groups were significantly higher in relation to the controls (P < 0.05). On the other hand, no differences were detected regarding structural and numerical CAs in the communities evaluated. Additionally, the observed levels of DNA strand breaks and frequencies of CAs, stratified for exposure time, were not statistically different for individuals of either rural community. Our results suggest that the damages caused by pesticides in our study area were not great enough to induce permanent mutations or to interfere with mitotic apparatus formation; minimal pesticide damages could have undergone cellular repair, explaining the absence of structural and numerical CAs. Environ. Mol. Mutagen. 2011. © 2011 Wiley‐Liss, Inc.
Novel control and steady-state correction method for standard 28-day bioaccumulation tests using Nereis virens
Authors: Bennett Erin R , Steevens Jeffery A , Lotufo Guilherme R , Paterson Gord , Drouillard Ken G
Published: March 2011

Evaluation of dredged material for aquatic placement requires assessment of bioaccumulation potentials for benthic organisms using standardized laboratory bioaccumulation tests. Critical to the interpretation of these data is the assessment of steady state for bioaccumulated residues needed to generate biota sediment accumulation factors (BSAFs) and to address control correction of day 0 contaminant residues measured in bioassay organisms. This study applied a novel performance reference compound approach with a pulse-chase experimental design to investigate elimination of a series of isotopically labeled polychlorinated biphenyl (13C-PCBs) in the polychaete worm Nereis virens while simultaneously evaluating native PCB bioaccumulation from field-collected sediments. Results demonstrated that all 13C-PCBs, with the exception of 13C-PCB209 (> 80%), were eliminated by more than 90% after 28 d. The three sediment types yielded similar 13C-PCB whole-body elimination rate constants (ktot) producing the following predictive equation: log ktot =  − 0.09 × log KOW − 0.45. The rapid loss of 13C-PCBs from worms over the bioassay period indicated that control correction, by subtracting day 0 residues, would result in underestimates of bioavailable sediment residues. Significant uptake of native PCBs was observed only in the most contaminated sediment and proceeded according to kinetic model predictions with steady-state BSAFs ranging from 1 to 3 and peaking for congeners of log KOW between 6.2 and 6.5. The performance reference compound approach can provide novel information about chemical toxicokinetics and also serve as a quality check for the physiological performance of the bioassay organism during standardized bioaccumulation testing. Environ. Toxicol. Chem. 2011; 30:1366–1375. © 2011 SETAC
The improved space–time conservation element and solution element scheme for two‐dimensional dam‐break flow simulation
Authors: Zhang Yongxiang , Zeng Zhong , Chen Jingqiu
Published: March 2011

A new numerical scheme, namely space–time conservation element and solution element (CE/SE) method, has been used for the solution of the two‐dimensional (2D) dam‐break problem. Distinguishing from the well‐established traditional numerical methods (such as characteristics, finite difference, finite element, and finite‐volume methods), the CE/SE scheme has many non‐traditional features in both concept and methodology: space and time are treated in a unified way, which is the most important characteristic for the CE/SE method; the CEs and SEs are introduced, both local and global flux conservations in space and time rather than space only are enforced; an explicit scheme with a stagger grid is adopted. Furthermore, this scheme is robust and easy to implement. In this paper, an improved CE/SE scheme is extended to solve the 2D shallow water equations with the source terms, which usually plays a critical role in dam‐break flows. To demonstrate the accuracy, robustness and efficiency of the improved CE/SE method, both 1D and 2D dam‐break problems are simulated numerically, and the results are consistent with either the analytical solutions or experimental results. Copyright © 2011 John Wiley & Sons, Ltd.
Guidelines for psychosocial interventions in dementia care: a European survey and comparison
Authors: Vasse E. , Vernooij‐Dassen M. , Cantegreil I. , Franco M. , Dorenlot P. , Woods B. , Moniz‐Cook E.
Published: March 2011

Objective

The effectiveness of psychosocial interventions in treating people with dementia and their carers is increasingly emphasised in the literature. Dementia guidelines should summarise the scientific evidence and best practice that is currently available, therefore, it should include recommendations for psychosocial interventions. The aims of our study were (1) to collate dementia guidelines from countries across Europe and to check whether they included sections about psychosocial interventions, and (2) to compare the methodological quality and the recommendations for specific psychosocial interventions in these guidelines.

Methods

The European dementia guidelines were inventoried. The methodological quality of the guideline sections for psychosocial interventions was assessed with the (AGREE) Appraisal of Guidelines Research and Evaluation instrument. The recommendations for specific psychosocial interventions were extracted from each of these guidelines and compared.

Results

Guidelines for psychosocial interventions were found in five of 12 countries. Guideline developers, methodological quality and appreciation of available evidence influenced the inclusion of psychosocial interventions in dementia guidelines from Germany, Italy, the Netherlands, Spain and the UK. The UK NICE SCIE guideline had the best methodological quality and included the most recommendations for psychosocial interventions. Physical activity and carer interventions were recommended the most across all guidelines.

Conclusion

The inclusion of psychosocial interventions in dementia guidelines is limited across Europe. High‐quality guidelines that include psychosocial interventions and are kept up to date with the emerging evidence are needed. Throughout Europe, special attention to the implementation of evidence‐based psychosocial care is needed in the next few years. Copyright © 2011 John Wiley & Sons, Ltd.
Meta-analysis of the influence of I148M variant of patatin-like phospholipase domain containing 3 gene (PNPLA3) on the susceptibility and histological severity of nonalcoholic fatty liver disease
Authors: Sookoian Silvia , Pirola Carlos J.
Published: March 2011

Our objective was to estimate the strength of the effect of the I148M (rs738409 C/G) patatin-like phospholipase domain containing 3 ( PNPLA3) variant on nonalcoholic fatty liver (NAFLD) and disease severity across different populations. We performed a systematic review by a meta-analysis; literature searches identified 16 studies. Our results showed that rs738409 exerted a strong influence not only on liver fat accumulation (GG homozygous showed 73% higher lipid fat content when compared with CC ones, data from 2,937 subjects; P < 1 × 10−9), but also on the susceptibility of a more aggressive disease (GG homozygous had 3.24-fold greater risk of higher necroinflammatory scores and 3.2-fold greater risk of developing fibrosis when compared with CC homozygous; P < 1 × 10−9; data from 1,739 and 2,251 individuals, respectively). Nonalcoholic steatohepatitis (NASH) was more frequently observed in GG than CC homozygous (odds ratio [OR] 3.488, 95% confidence interval [CI] 1.859–6.545, random model; P < 2 × 10−4; data from 2,124 patients). Evaluation of the risk associated with heterozygosity for the variant suggests that the additive genetic model best explains the effect of rs738409 on the susceptibility to develop NAFLD. Nevertheless, carrying two G alleles does not seem to increase the risk of severe histological features. Meta-regression showed a negative correlation between male sex and the effect of rs738409 on liver fat content (slope: −2.45 ± 1.04; P < 0.02). The rs738409 GG genotype versus the CC genotype was associated with a 28% increase in serum alanine aminotransferase levels.

Conclusion:

By summarizing the amount of evidence, this study provided unequivocal evidence of rs738409 as a strong modifier of the natural history of NAFLD in different populations around the world. (HEPATOLOGY 2011;)
High predictive accuracy of an unbiased proteomic profile for sustained virologic response in chronic hepatitis C patients
Authors: Patel Keyur , Lucas Joseph E. , Thompson Will J. , Dubois Laura G. , Tillmann Hans L. , Thompson Alexander J. , Uzarski Diane , Califf Robert M. , Moseley Martin A. , Ginsburg Geoffrey S. , McHutchison John G. , McCarthy Jeanette J.
Published: March 2011

Chronic hepatitis C (CHC) infection is a leading cause of endstage liver disease. Current standard-of-care (SOC) interferon-based therapy results in sustained virological response (SVR) in only one-half of patients, and is associated with significant side effects. Accurate host predictors of virologic response are needed to individualize treatment regimens. We applied a label-free liquid chromatography mass spectrometry (LC-MS)-based proteomics discovery platform to pretreatment sera from a well-characterized and matched training cohort of 55 CHC patients, and an independent validation set of 41 CHC genotype 1 patients with characterized IL28B genotype. Accurate mass and retention time methods aligned samples to generate quantitative peptide data, with predictive modeling using Bayesian sparse latent factor regression. We identified 105 proteins of interest with two or more peptides, and a total of 3,768 peptides. Regression modeling selected three identified metaproteins, vitamin D binding protein, alpha 2 HS glycoprotein, and Complement C5, with a high predictive area under the receiver operator characteristic curve (AUROC) of 0.90 for SVR in the training cohort. A model averaging approach for identified peptides resulted in an AUROC of 0.86 in the validation cohort, and correctly identified virologic response in 71% of patients without the favorable IL28B “responder” genotype. Conclusion: Our preliminary data indicate that a serum-based protein signature can accurately predict treatment response to current SOC in most CHC patients. (HEPATOLOGY 2011)
Nanoscale spectroscopy and imaging of hemoglobin
Authors: Kennedy Eamonn , Yarrow Fiona , Rice James H.
Published: March 2011

Sub diffraction limited infrared absorption imaging of hemoglobin was performed by coupling IR optics with an atomic force microscope. Comparisons between the AFM topography and IR absorption images of micron sized hemoglobin features are presented, along with nanoscale IR spectroscopic analysis of the metalloprotein. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
In vitro osteoblastic differentiation of human mesenchymal stem cells and human dental pulp stem cells on poly‐L‐lysine‐treated titanium‐6‐aluminium‐4‐vanadium
Authors: Galli Daniela , Benedetti Laura , Bongio Matilde , Maliardi Valentina , Silvani Giulia , Ceccarelli Gabriele , Ronzoni Flavio , Conte Silvio , Benazzo Francesco , Graziano Antonio , Papaccio Gianpaolo , Sampaolesi Maurilio , Cusella De Angelis Maria Gabriella
Published: March 2011

Three‐dimensional (3D) titanium‐6‐aluminium‐4‐vanadium (Ti6Al4V) is a widely used biomaterial for orthopedic prosthesis and dental implants; thanks to its very high‐mechanical strength and resistance to corrosion. Human mesenchymal stem cells (hMSCs) and dental pulp stem cells (hDPSCs) are responsible for bone regeneration following colonization of prosthesis or dental implants. Both hMSCs and hDPSCs have lower ability to colonize this biomaterial in comparison with tissue culture‐treated plastic. Both hMSCs and hDPSCs show lack of focal adhesion kinase (FAK) activation when grown on Ti6Al4V. This signal is restored in the presence of poly‐L‐lysine (poly‐L‐lys). Poly‐L‐lys has been used as part of organoapatite or together with zinc and calcium ions. Our results suggest that poly‐L‐lys alone induces FAK activation through β1‐INTEGRIN, because the presence of β1‐INTEGRIN blocking antibody avoided FAK autophosphorylation. Presence of poly‐L‐lys also increases expression of osteoblastic differentiation marker genes in hMSCs and hDPSCs grown on Ti6Al4V. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part A:, 2011.
Engineering an antiplatelet adhesion layer on an electrospun scaffold using porcine endothelial progenitor cells
Authors: Zhang Xing , Xu Yuanyuan , Thomas Vinoy , Bellis Susan L. , Vohra Yogesh K.
Published: March 2011

In coronary artery bypass graft interventions, luminal thrombosis is one of the greatest challenges for polymeric grafts with a luminal diameter less than 4 mm. Previously, we reported the fabrication of a highly porous micro/nanofibrous electrospun scaffold and demonstrated the excellent biocompatibility of the scaffolding materials with human endothelial cells. In this study, we explored the engineering of an antithrombotic layer on the scaffold's lumen within 48 h, using peripheral blood‐derived porcine endothelial progentior cells (EPC). Flow cytometric results showed that they were CD31− but highly CD34+ and CD105+, suggesting the primitive nature of these freshly isolated EPC. The vast majority of EPC readily took up low density lipoprotein, confirming their endothelial phenotype. These EPC also exhibited a strong proliferation capacity on the scaffold for up to 11 days. A confluent layer could be easily engineered within 24 h, which successfully prevented platelet adhesion, a critical step in the cascade of thrombotic events. We concluded that this scaffold could afford a convenient means for the regeneration of a functional cardiovascular endothelium shortly after implantation. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part A:, 2011.
Stimulation of fibroblasts and neuroblasts on a biomimetic extracellular matrix consisting of tandem repeats of the elastic VGVPG domain and RGD motif
Authors: Jeon Won Bae , Park Bo Hyung , Wei Junjun , Park Rang‐Woon
Published: March 2011

Elastin‐like proteins (ELPs) modeled after tropoelastin are favored in the development of biomimetic matrices due to their biocompatibility and the possibility to precisely control their environmental responsiveness, mechanical properties, and fate within the cells by recombinant DNA technology‐mediated design at the gene level. However, a basic prerequisite in the use of ELPs as cell culture matrices is the presence of a biofunctionality that can induce adhesion‐mediated signaling pathways. To activate fibronectin‐integrin signaling events from a cell‐matrix interface and direct cell survival and proliferation, we biosynthesized a modular ELP, represented as TGPG[VGRGD(VGVPG)6]20WPC, consisting of alternating elastic (VGVPG)6 structural domains and cell‐binding VGRGD motifs that are intended to emulate various aspects of extracellular matrix proteins. The inverse transition curves of [VGRGD(VGVPG)6]20 and (VGVPG)140 overlapped with each other, indicating that one VGRGD sequence fused with six elastic pentapeptides did not disturb the thermal sensitivity of [VGRGD(VGVPG)6]20. The cell adhesion activity of [VGRGD(VGVPG)6]20 toward HEK293 fibroblasts and N2A neuroblasts was similar to that of native fibronectin. Upon contact with [VGRGD(VGVPG)6]20, the fibroblasts exhibited a flattened polygonal morphology, and the neuroblasts synthesized new DNA and proliferated. On the basis of these physiological changes, we concluded that RGD‐functionalized ELP triggers the activation of signaling cascades within cells and can be used as an elastin‐like matrix for mammalian cell culture. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part A:, 2011.
Mild hyponatremia as a risk factor for fractures: The rotterdam study
Authors: Hoorn Ewout J , Rivadeneira Fernando , van Meurs Joyce BJ , Ziere Gijsbertus , Stricker Bruno HCh , Hofman Albert , Pols Huibert AP , Zietse Robert , Uitterlinden André G , Zillikens M Carola
Published: March 2011

Recent studies suggest that mild hyponatremia is associated with fractures, but prospective studies are lacking. We studied whether hyponatremia is associated with fractures, falls, and/or bone mineral density (BMD). A total of 5208 elderly subjects with serum sodium assessed at baseline were included from the prospective population-based Rotterdam Study. The following data were analyzed: BMD, vertebral fractures (mean follow-up 6.4 years), nonvertebral fractures (7.4 years), recent falls, comorbidity, medication, and mortality. Hyponatremia was detected in 399 subjects (7.7%, 133.4 ± 2.0 mmol/L). Subjects with hyponatremia were older (73.5 ± 10.3 years versus 70.0 ± 9.0 years, p < .001), had more recent falls (23.8% versus16.4%, p < .01), higher type 2 diabetes mellitus prevalence (22.2% versus 10.3%, p < .001), and more often used diuretics (31.1% versus 15.0%, p < .001). Hyponatremia was not associated with lower BMD but was associated with increased risk of incident nonvertebral fractures [hazard ratio (HR) =1.39, 95% confidence interval (CI) 1.11–1.73, p = .004] after adjustment for age, sex, and body mass index. Further adjustments for disability index, use of diuretics, use of psycholeptics, recent falls, and diabetes did not modify results. In the fully adjusted model, subjects with hyponatremia also had increased risk of vertebral fractures at baseline [odds ratio (OR) = 1.78, 95% CI 1.04–3.06, p = .037] but not at follow-up. Finally, all-cause mortality was higher in subjects with hyponatremia (HR = 1.21, 95% CI 1.03–1.43, p = .022). It is concluded that mild hyponatremia in the elderly is associated with an increased risk of vertebral fractures and incident nonvertebral fractures but not with BMD. Increased fracture risk in hyponatremia also was independent of recent falls, pointing toward a possible effect on bone quality. © 2011 American Society for Bone and Mineral Research
PAK4 is required for regulation of the cell‐cycle regulatory protein p21, and for control of cell‐cycle progression
Authors: Nekrasova Tanya , Minden Audrey
Published: March 2011

The serine/threonine kinase PAK4 regulates cytoskeletal architecture, and controls cell proliferation and survival. In most adult tissues PAK4 is expressed at low levels, but overexpression of PAK4 is associated with uncontrolled proliferation, inappropriate cell survival, and oncogenic transformation. Here we have studied for the first time, the role for PAK4 in the cell cycle. We found that PAK4 levels peak dramatically but transiently in the early part of G1 phase. Deletion of Pak4 was also associated with an increase in p21 levels, and PAK4 was required for normal p21 degradation. In serum‐starved cells, the absence of PAK4 led to a reduction in the amount of cells in G1, and an increase in the amount of cells in G2/M phase. We propose that the transient increase in PAK4 levels at early G1 reduces p21 levels, thereby abrogating the activity of CDK4/CDK6 kinases, and allowing cells to proceed with the cell cycle in a precisely coordinated way. J. Cell. Biochem. 112: 1795–1806, 2011. © 2011 Wiley‐Liss, Inc.
Basic fibroblast growth factor inhibits mineralization but induces neuronal differentiation by human dental pulp stem cells through a FGFR and PLCγ signaling pathway
Authors: Osathanon Thanaphum , Nowwarote Nunthawan , Pavasant Prasit
Published: March 2011

Basic fibroblast growth factor (basic FGF) has pivotal roles in the function of various cell types. Here, we report the effects of basic FGF in the regulation of dental pulp stem cell (DPSC) behaviors including maintaining stemness and directing differentiation. Cells isolated from human dental pulp tissues exhibited stem cell properties including the expression of mRNA markers for embryonic and mesenchymal stem cells, the expression of Stro‐1, and the multipotential differentiation. Basic FGF stimulated colony‐forming units of DPSCs and up‐regulated the expression of the embryonic stem cell markers; Oct4, Rex‐1, and Nanog. Moreover, osteogenic medium containing basic FGF inhibited alkaline phosphatase enzymatic activity and mineralization of DPSCs. On the contrary, basic FGF appeared to be an influential growth factor in the neurogenic differentiation of DPSCs. In the presence of basic FGF, increased DPSCs neurosphere size and the up‐regulation of neurogenic markers were noted. Inhibitors of FGFR or PLCγ were able to ablate the basic FGF‐induced neuronal differentiation of DPSCs. Taken together, these results suggest basic FGF may be involved in the mechanisms controlling DPSCs cell fate decisions. J. Cell. Biochem. 112: 1807–1816, 2011. © 2011 Wiley‐Liss, Inc.
Body composition changes and inhibition of fat development in vivo implicates androgen in regulation of stem cell lineage allocation
Authors: Semirale Anthony A. , Zhang Xiao‐Wei , Wiren Kristine M.
Published: March 2011

Androgens regulate body composition in youth and declining testosterone that occurs with aging is associated with muscle wasting, increased fat mass and osteopenia. Transgenic mice with targeted androgen receptor (AR) over‐expression in mesenchymal stem cells (MSC) were generated to explore the role of androgen signaling in the regulation of body composition. Transgenic males, but not females, were shorter and have reduced body weight and visceral fat accumulation. Dual‐energy X‐ray absorptiometry (DXA) revealed significant reductions in fat mass with a reciprocal increase in lean mass, yet no difference in food consumption or locomotor activity was observed. Adipose tissue weight was normal in brown fat but reduced in both gonadal and perirenal depots, and reduced hyperplasia was observed with smaller adipocyte size in visceral and subcutaneous white adipose tissue. Although serum leptin, adiponectin, triglyceride, and insulin levels were no different between the genotypes, intraperitoneal glucose tolerance testing (IPGTT) showed improved glucose clearance in transgenic males. High levels of the AR transgene are detected in MSCs but not in mature fat tissue. Reduced fibroblast colony forming units indicate fewer progenitor cells resident in the marrow in vivo. Precocious expression of glucose transporter 4 (GLUT4), peroxisome proliferator‐activated receptor γ (PPARγ), and CCAAT enhancer‐binding protein α (C/EBPα) was observed in proliferating precursor cultures from transgenic mice compared to controls. In more mature cultures, there was little difference between the genotypes. We propose a mechanism where enhanced androgen sensitivity can alter lineage commitment in vivo to reduce progenitor number and fat development, while increasing the expression of key factors to promote smaller adipocytes with improved glucose clearance. J. Cell. Biochem. 112: 1773–1786, 2011. © 2011 Wiley‐Liss, Inc.
Protein side chain modeling with orientation‐dependent atomic force fields derived by series expansions
Authors: Liang Shide , Zhou Yaoqi , Grishin Nick , Standley Daron M.
Published: March 2011

We describe the development of new force fields for protein side chain modeling called optimized side chain atomic energy (OSCAR). The distance‐dependent energy functions (OSCAR‐d) and side‐chain dihedral angle potential energy functions were represented as power and Fourier series, respectively. The resulting 802 adjustable parameters were optimized by discriminating the native side chain conformations from non‐native conformations, using a training set of 12,000 side chains for each residue type. In the course of optimization, for every residue, its side chain was replaced by varying rotamers, whereas conformations for all other residues were kept as they appeared in the crystal structure. Then, the OSCAR‐d were multiplied by an orientation‐dependent function to yield OSCAR‐o. A total of 1087 parameters of the orientation‐dependent energy functions (OSCAR‐o) were optimized by maximizing the energy gap between the native conformation and subrotamers calculated as low energy by OSCAR‐d. When OSCAR‐o with optimized parameters were used to model side chain conformations simultaneously for 218 recently released protein structures, the prediction accuracies were 88.8% for χ1, 79.7% for χ1 + 2, 1.24 Å overall root mean square deviation (RMSD), and 0.62 Å RMSD for core residues, respectively, compared with the next‐best performing side‐chain modeling program which achieved 86.6% for χ1, 75.7% for χ1 + 2, 1.40 Å overall RMSD, and 0.86 Å RMSD for core residues, respectively. The continuous energy functions obtained in this study are suitable for gradient‐based optimization techniques for protein structure refinement. A program with built‐in OSCAR for protein side chain prediction is available for download at http://sysimm.ifrec.osaka‐u.ac.jp/OSCAR/. © 2011 Wiley Periodicals, Inc. J Comput Chem 2011