bluuebunny/crossref_metadata_2025_split huggingface dataset:
Polymorphism and Phonon Dynamics of α‐Quaterthiophene
Authors: Ranzieri Paolo , Girlando Alberto , Tavazzi Silvia , Campione Marcello , Raimondo Luisa , Bilotti Ivano , Brillante Aldo , Della Valle Raffaele G. , Venuti Elisabetta 
Published: February 2009

AbstractTwo 4T: Low‐frequency micro‐Raman spectroscopy coupled with lattice dynamics calculations is an invaluable tool for investigating polymorphism in organic semiconductors. The Raman spectra of the low‐temperature (LT) and high‐temperature (HT) polymorphs of α‐quaterthiophene (4T) are presented and interpreted (see picture). Raman mapping is applied to investigate the phase purity.magnified imageLow‐frequency (10–150 cm−1) Raman spectra of the low‐temperature (LT) and high‐temperature (HT) polymorphs of the organic semiconductor α‐quaterthiophene at 300 and 10 K are reported. Polarized spectra, assisted by quasi‐harmonic lattice dynamics (QHLD) calculations, allow characterization of the lattice phonon dynamics and identification of the two phases spectroscopically. The experimental data can be explained by taking into account the coupling between intermolecular (lattice) and low‐frequency intramolecular modes. Finally, Raman mapping is used to investigate the phase purity.
Adduct Formation of Dichloridodioxidomolybdenum(VI) and Methyltrioxidorhenium(VII) with a Series of Bidentate Nitrogen Donor Ligands
Authors: Al‐Ajlouni Ahmad M. , Günyar Alev , Zhou Ming‐Dong , Baxter Paul N. W. , Kühn Fritz E. 
Published: February 2009

AbstractThe stability of a variety of bidentate N‐base adducts of MoO2Cl2 and (CH3)ReO3 (MTO) was investigated in thf and CH2Cl2 as solvents. The formation constants were determined from the spectrophotometric data based on 1:1 adduct formation. The adduct formation constants for [MoO2Cl2L2] (L2 = bidentate nitrogen ligand) are 104–106 times higher than those for [(CH3)ReO3L2] with the same ligands under the same conditions. The adduct stability of both systems is very sensitive to the electronic nature of the ligands and increases with their donor ability. Hammett correlations of the formation constants against σ give relatively large negative values for the reaction constants (ρRe = –5.9, ρMo = –6.6). The stability is also governed by steric and strain factors. Thus, sterically hindered 6,6′‐disubstituted‐2,2′‐bipyridines do not form adducts with MTO, and only 6,6′‐dimethyl‐ and 6,6′‐diphenyl‐2,2′‐bipyridines form adducts with MoO2Cl2. However, these adducts are much less stable than other methyl derivatives of 2,2′‐bipridine adducts. The steric strain between the two methyl groups in 3,3‐dimethyl‐2,2′‐bipyridine influences the bipyridine planarity upon complexation and reduces the adduct stability. The thermodynamic parameters (enthalpy and entropy) were determined from temperature‐dependence studies. The adduct stability is mainly due to the strongly exothermic binding of the nitrogen‐bidentate ligand. The entropy change is small and has little effect on adduct stability.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Single‐Crystal Structure Determination and Solid‐State NMR Investigations of Lithium Nitridosilicate Li2SiN2 Synthesized by a Precursor Approach Employing Amorphous “Si(CN2)2”
Authors: Pagano Sandro , Zeuner Martin , Hug Stephan , Schnick Wolfgang 
Published: February 2009

AbstractAmorphous silicon bis(carbodiimide) “Si(CN2)2” has been identified as a reactive precursor for the synthesis of nitridosilicates that is specifically useful in the temperature region below 1000 °C. In this context the applicability and reactivity of amorphous “Si(CN2)2” towards Li3N in comparison to silicon diimide Si(NH)2 has been studied using high‐temperature in situ powder diffraction and DSC measurements. During the current investigation single crystals of Li2SiN2 have been obtained and the crystal structure of this Li+ ion conductor has been determined and refined: [Pbca, no. 61, a = 9.907(2), b = 9.907(2), c = 15.014(3) Å, Z = 32, R1 = 0.038, 1460 data, 142 parameters]. In the solid, Li2SiN2 consists of two interpenetrating cristobalite type nets which are made up from hetero‐adamantane‐like [Si4N6]N4/2 groups. The eight crystallographically independent Li+ sites are ordered at room temp. and exhibit coordination numbers 3 to 5. The 7Li and 29Si solid‐state MAS NMR spectra of Li2SiN2 are reported. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
“One‐Pot” Ion‐Exchange and Mesopore Formation During Desilication
Authors: Holm Martin Spangsberg , Hansen Martin Kalmar , Christensen Claus Hviid 
Published: February 2009

AbstractA desilication protocol using tetramethylammonium hydroxide was applied to zeolite beta. The new route presented here integrates the desilication and ion‐exchange post‐treatment steps allowing for a subsequent ion‐exchange step to be avoided. It is shown that the acidic and highly mesoporous zeolite is obtained directly upon calcination. Thus, careful choice of base and post‐treatment conditions lead to the fabrication of a hierarchical meso‐ and microporous structure with completely retained crystallinity.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Bridging Vinyliminium‐ and Enaminoalkylidenediiron Complexes as Organometallic Ligands
Authors: Busetto Luigi , Marchetti Fabio , Mazzoni Rita , Salmi Mauro , Zacchini Stefano , Zanotti Valerio 
Published: February 2009

AbstractThe SPh‐functionalized vinyliminium complexes [Fe2{μ‐η1:η3‐Cγ(R′)=Cβ(SPh)Cα=N(Me)(R)}(μ‐CO)(CO)(Cp)2][SO3CF3](R = Xyl, R′ = Me, 3a; R = R′ = Me, 3b; R = Xyl, R′ = CH2OH, 3c; R = Me, R′ = CH2OH, 3d; Xyl = 2,6‐Me2C6H3; Cp = η5C5H5) react with NaBH4, in thf solution, to afford the corresponding μ‐vinylalkylidene complexes [Fe2{μ‐η1:η3‐Cγ(R′)Cβ(SPh)=Cα(H)N(Me)(R)}(μ‐CO)(CO)(Cp)2] (5a–d). This reaction transforms the iminium into an amine group, thereby generating an N‐donor functionality. Consequently, the bridging organic framework in 5a–d, which contains S and N donor atoms, can act as an ambidentate ligand toward coordinatively unsaturated metal fragments. In particular, the complexes [Fe2{μ‐η1:η3‐Cγ(R′)Cβ(SPh)=Cα(H)NMe2}(μ‐CO)(CO)(Cp)2] (R′ = Me, 5b; R′ = CH2OH, 5d) react with [PdCl2(CH3CN)2] to give [PdCl2(N,S‐5b)] (6a) and [PdCl2(N,S‐5d)] (6b), respectively. The molecular structure of 6b has been determined by X‐ray diffractometry. In an analogous reaction, compound 5d acts as an “organometallic ligand” for the unsaturated rhodium fragment generated upon treatment of [Rh(NBD)Cl]2 (NBD = norbornadiene) with AgClO4. This reaction affords the trinuclear complex [Rh(NBD)(κ2‐N,S‐5d)][ClO4] (7). The bridging ligand in the zwitterionic complex [Fe2{μ‐η1:η3‐Cγ(CH2OH)=Cβ(S)Cα=N(Me)(Xyl)}(μ‐CO)(CO)(Cp)2] (2a) contains an OH group in addition to the N and S functionalities. This bridging framework acts as a O,S bidentate ligand and the reaction of 2a with [Ti(Cp)2(CH3CN)2](SO3CF3)2 leads to the formation of the adduct [Ti(Cp)2(κ2‐O,S‐2a)][SO3CF3]2 (8). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Stereocontrolled Preparation of Fully Substituted Cyclopentanes: Relevance to Total Synthesis
Authors: Heasley Brian 
Published: February 2009

AbstractThis Microreview aims to identify important advances in the asymmetric synthesis of fully substituted five‐membered carbocyclic ring systems. Recent efforts directed towards the intricate and densely functionalized core substructures of three distinct classes of cyclopentane‐based natural products will be examined. Strategies featuring high levels of stereocontrol and/or conciseness in the total number of synthetic steps required to access complex natural product ring fragments are highlighted. Stereoselective Diels–Alder cycloaddition approaches to access functionalized norbornene intermediates as latent chiral cyclopentanes in the tradition of Corey's elegant prostaglandin studies are a recurring theme. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Peripheral Functionalization of Subphthalocyanines
Authors: González‐Rodríguez David , Torres Tomás 
Published: February 2009

AbstractThe optimization of synthetic methodologies that lead to novel synthetically and electronically valuable SubPc molecules is of great interest for the use of these molecules in applied fields. In this work, we describe some useful procedures for the incorporation of diverse functional groups in the periphery of the SubPc macrocycle. Different metal‐catalyzed cross‐coupling reactions, including Stille or Suzuki couplings and palladium‐catalyzed borylation or amination reactions, have been optimized in order to obtain high yields and avoid SubPc decomposition. In addition, we report on the scope of the use of ether functionalities in the condensation reaction with BCl3 and on the synthesis of a trihydroxySubPc, a very valuable compound that could be obtained by deprotection of a silyloxy‐SubPc precursor. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Facile Synthesis and Structure of Novel 2,5‐Disubstituted 1,3,4‐Selenadiazoles
Authors: Hua Guoxiong , Li Yang , Fuller Amy L. , Slawin Alexandra M. Z. , Woollins J. Derek 
Published: February 2009

AbstractThe reaction of hydrazide with carbonyl chloride in the presence of sodium carbonates leads to the corresponding 1,2‐diacylhydrazines [1a–t, R1C(O)NHNHC(O)R2, R1= aryl, R2= aryl or alkyl] in moderate to excellent yield (57–90 %). The latter reacts with 2,4‐diphenyl‐1,3‐diselenadiphosphetane‐2,4‐diselenide (Woollins' reagent,WR) in refluxing toluene to give a series of new 2,5‐disubstituted 1,3,4‐selenadiazoles (2a–t, 51–99 % yield). All compounds were characterized spectroscopically and six compounds were characterized crystallographically. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Subthreshold depression in Parkinson's disease
Authors: Nation Daniel A. , Katzen Heather L. , Papapetropoulos Spyridon , Scanlon Blake K. , Levin Bonnie E. 
Published: February 2009

AbstractObjectiveIt is estimated that 40% of patients with Parkinson's disease (PD) are clinically depressed, however, little is known about the frequency and associated features of subthreshold depression in PD. The current study sought to determine the prevalence of subthreshold depression (sD) and to further characterize the associated features in a sample of 111 nondemented patients with moderate to severe PD.MethodsPatients were classified into the following groups: diagnostic depression (DD), subthreshold depression (sD), or nondepressed (ND) by applying the Diagnostic and Statistical Manual, 4th edn criteria for depression and previously reported criteria for sD to items from the Beck Depression Inventory, 2nd edn. These groups were compared on clinical and demographic variables. The symptom profile of the sD group is also described.ResultsFifty participants (45.0%) were classified as ND, 32 (28.8%) as sD, and 29 (26.1%) as DD. Patients with sD were younger (∼5 yrs) than nondepressed patients, but did not differ in disease stage or any other demographic variables. Patients with sD tended to endorse mood symptoms that overlap with PD, including fatigue, sleep difficulties, appetite dysfunction, and concentration difficulties. These symptoms were also endorsed with high frequency by the other groups.ConclusionsThese findings suggest that sD is not uncommon in PD and may be more prevalent among younger patients. The finding that sD patients report mood symptoms that overlap with the PD symptomatology suggests that these two entities share common features and may be difficult to disentangle. Copyright © 2009 John Wiley & Sons, Ltd.
Nutritional model of steatohepatitis and metabolic syndrome in the Ossabaw miniature swine #
Authors: Lee Lydia , Alloosh Mouhamad , Saxena Romil , Van Alstine William , Watkins Bruce A. , Klaunig James E. , Sturek Michael , Chalasani Naga 
Published: February 2009

Abstract
Miniature pigs residing in the Ossabaw Island (Ossabaw pigs) exhibit a thrifty genotype, and when fed a high-calorie diet they consistently develop metabolic syndrome defined by obesity, insulin resistance, hypertension, and dyslipidemia. We conducted a study to induce steatohepatitis in Ossabaw pigs by dietary manipulation. Pigs were fed standard chow (controls, n = 15), high-fructose diet (20% kcal from fructose and 10.5% kcal from fat) (fructose group, n = 9), atherogenic diet (20% kcal from fructose and 46% kcal from fat and 2% cholesterol and 0.7% cholate by weight) (atherogenic diet group, n = 13), and modified atherogenic diet (different source of fat and higher protein but lower choline content) (M-Ath diet group, n = 7). All animals were sacrificed at 24 weeks after dietary intervention. The high-fructose group had significant weight gain, hypertension, and insulin resistance but showed normal liver histology. The atherogenic diet group had metabolic syndrome and abnormal liver histology consisting of significant microvesicular steatosis and fatty Kupffer cells but no ballooning or fibrosis. The M-Ath diet group developed severe metabolic syndrome and markedly abnormal liver histology with macrovesicular and microvesicular steatosis, fatty Kupffer cells, extensive hepatocyte ballooning, and pericellular/perisinusoidal fibrosis. Compared with controls, the M-Ath diet group had significantly lower serum adiponectin but higher serum leptin and tumor necrosis factor (TNF) levels and higher hepatic triglyceride and malondialdehyde levels. Conclusion: Ossabaw pigs fed a modified atherogenic diet develop severe metabolic syndrome and abnormal liver histology with close resemblance to human nonalcoholic steatohepatitis (NASH). (Hepatology 2009.)
Development of a 3D collagen scaffold coated with multiwalled carbon nanotubes
Authors: Hirata Eri , Uo Motohiro , Takita Hiroko , Akasaka Tsukasa , Watari Fumio , Yokoyama Atsuro 
Published: February 2009

AbstractCarbon nanotubes (CNTs) have attractive biochemical properties such as strong cell adhesion and protein absorption, which are very useful for a cell cultivation scaffold. In this study, we prepared a multiwalled carbon nanotube‐coated collagen sponge (MWCNT‐coated sponge) to improve the surface properties of the collagen sponge, and its cell culturing properties were examined. The suface of the collagen sponge was homogeneously coated with MWCNTs by dispersion. MC3T3‐E1 cells were cultured on and inside the MWCNT‐coated sponge. The DNA content on the MWCNT‐coated sponge after 1 week of culture was significantly higher than on an uncoated collagen sponge (p < 0.05). There was no significant difference between the estimated ALP activity normalized by DNA quantity on the MWCNT‐coated sponge and that on the uncoated collagen sponge which is well known as one of the best scaffolds for cell cultivation. In addition, the MWCNT‐coated surface shows strong cell adhesion. Therefore, the MWCNT‐coated collagen sponge is expected to be a useful 3D scaffold for cell cultivation. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009
Modeling solvent evaporation during the manufacture of controlled drug‐release coatings and the impact on release kinetics
Authors: Kim Chang‐Soo , Saylor David M. , McDermott Martin K. , Patwardhan Dinesh V. , Warren James A. 
Published: February 2009

AbstractTo improve functionality and performance, controlled drug‐release coatings comprised of drug and polymer are integrated with traditional medical devices, e.g., drug eluting stents. Depending on manufacturing conditions, these coatings can exhibit complex microstructures. Previously, a thermodynamically consistent model was developed for microstructure evolution in these systems to establish relationships between process variables, microstructure, and the subsequent release kinetics. Calculations based on the model were, in general, consistent with experimental findings. However, because of assumptions regarding the evaporation of solvent during fabrication, the model was unable to capture variations through the coating thickness that are observed experimentally. Here, a straightforward method is introduced to incorporate solvent evaporation explicitly into the model. Calculations are used to probe the impact of solvent evaporation rate and drug loading on the microstructure that forms during manufacturing and subsequent drug release kinetics. The predicted structures and release kinetics are found to be consistent with experimental observations. Further, the calculations demonstrate that solvent evaporation rate can be as critical to device performance as the amount of drug within the coating. For example, changes of a factor of five in the amount of drug released were observed by modifying the rate of solvent evaporation during manufacturing. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009
Comparison of 3‐dimensional with 2‐dimensional saline infusion sonohysterograms for the evaluation of intrauterine abnormalities
Authors: Terry Stephanie , Banks Erika , Harris Kemoy , Duvivier Roger , Dar Pe'er 
Published: February 2009

AbstractObjective.To compare 3‐dimensional saline infusion sonohysterography (3DSIS) with 2‐dimensional sonohysterography (2DSIS) using hysteroscopy and histologic diagnosis as the gold standard.Method.A retrospective analysis of all SIS examination performed between July 1, 2005 and April 30, 2007 in our gynecological sonographic unit. 2DSIS or 3DSIS sonographic techniques were used randomly. Management decisions and operative procedures were done by the referring provider. Patients that had diagnostic hysteroscopy and complete histologic evaluation were included. Concordance between the various assessment methods as well as sensitivity and specificity were compared between 2DSIS and 3DSIS. Student's t test and chi‐square test were used for statistical analysis. p < 0.05 was considered statistically significant.Result.Of 804 patients that had SIS, 125 patients met the inclusion criteria. Patient median age was 48 (range 19–82). Also, 77 patients were premenopausal, and 48 patients were postmenopausal. Furthermore, 43 patients had 2DSIS and 82 patients had 3DSIS. 3DSIS was found to correlate with hysteroscopic findings more often than 2DSIS (p < 0.05). A trend for higher specificity of 3DSIS with the different uterine pathologies was seen, but it did not reach statistical significance. No difference in sensitivity of 3DSIS compared with 2DSIS was found for all pathologic diagnoses.Conclusion.3DSIS correlated better with hysteroscopy than 2DSIS. Specificity for histologic diagnosis appears to be higher with 3DSIS compared with 2DSIS but larger‐scale studies are needed to confirm this finding. © 2009 Wiley Periodicals, Inc. J Clin Ultrasound 2009
Efficient synthesis of 1,2,4‐triazolo[4,3‐a][1,8]naphthyridines under microwave irradiation
Authors: Mogilaiah K. , Swamy T. Kumara , Kumar K. Shiva 
Published: February 2009

Abstract
magnified imageA simple and highly efficient procedure has been described for the synthesis of 6‐aryl‐9‐(4‐phenoxphenyl)‐1,2,4‐triazolo [4,3‐a] [1,8] napthyridines (4) by the oxidation of 4‐phenoxybenzaldehyde 3‐aryl‐1,8‐naphthyridin‐2‐ylhydrazones (3) with chloramines‐T in methanol under microwave irradiation. The products were obtained in very good yields and excellent purities. J. Heterocyclic Chem., 46, 124 (2009).
Functionalization of benzo[c,d]indole system for the synthesis of visible and near‐infrared dyes
Authors: Henary Maged , Mojzych Mariusz , Say Martial , Strekowski Lucjan 
Published: February 2009

Abstract
magnified imageA number of benzo[c,d]indolium derivatives have been synthesized. J. Heterocyclic Chem., 46, 84 (2009).
High‐pressure Raman spectra of deuterated L‐alanine crystal
Authors: Gonçalves R. O. , Freire P. T. C. , Bordallo H. N. , Lima J. A. , Melo F. E. A. , Filho J. Mendes , Argyriou D. N. , Lima R. J. C. 
Published: February 2009

AbstractRaman spectra of deuterated L‐alanine have been obtained at high‐pressure conditions. A phase transition at ∼1.5 GPa associated with the splitting of some internal modes and increase of the wavenumber of the external modes was observed. Similarly to the hydrogenated L‐alanine crystal, this first transition was related to a symmetry change. Moreover, further modifications of the Raman spectra were observed at 4.4 GPa, which may be associated to conformational changes of the molecule. To give further support to such a hypothesis, neutron powder diffraction measurements were performed. Information about the cell parameter at atmospheric pressure gave valuable information about the ND distances, shedding light on the behavior of the torsional vibration of ND3+. Copyright © 2009 John Wiley & Sons, Ltd.
Theory of coherent anti‐Stokes Raman scattering for mesoscopic particle with complex molecules: angular‐dependent spectrum
Authors: Raymond Ooi C. H. 
Published: February 2009

AbstractWe present a microscopic theory of nonlinear scattering of mesoscopic particle that may be composed of complex molecules. We predict that the spectrum of the scattered field depends on the angle of observation. Transform theory is used to compute the third‐order susceptibility for coherent anti‐Stokes Raman scattering (CARS) of molecules with known absorption spectrum and vibrational modes. By incorporating the theory into an integral scattering formula, we develop a rigorous theory which leads to powerful numerical experimentation of nonlinear optical process in mesoscopic systems composed of complex molecules and driven by laser pulses with arbitrary shape and spectral content. We obtain an expression for spectral dependent CARS field which includes multiple internal reflection and refraction of the incident fields via Mie theory. The theory is used to study the variations of the CARS spectra and intensity on laser parameters and direction of detection. High‐resolution spectra computed for hybrid CARS scheme shows that the relative intensities of the characteristic peaks in the CARS spectrum depend on the direction of detection. This effect can be explained by the interference between the linear response (absorption and dispersion) and the four‐wave mixing process in the mesoscopic medium. The theory is useful for nonlinear spectroscopy, microscopy and nanophotonics involving small particles. Copyright © 2009 John Wiley & Sons, Ltd.
Surface enhanced Raman scattering of nano diamond using visible‐light‐activated TiO2 as a catalyst to photo‐reduce nano‐structured silver from AgNO3 as SERS‐active substrate
Authors: Hong Z.‐C. , Perevedentseva E. , Treschev S. , Wang J.‐B. , Cheng C.‐L. 
Published: February 2009

AbstractIn this work, we demonstrate nano‐structured silver particles photo‐reduced from silver nitride (AgNO3) solution using visible‐light‐activated titanium dioxide (TiO2), which can be a convenient and effective substrate for surface enhanced Raman spectroscopy (SERS) observation. Visible‐light‐activated carbon‐containing TiO2 nanoparticles are applied to photo‐reduce and form nano‐structured silver from AgNO3 upon visible‐light illumination. Photo‐reduced nano‐structured silver is used as an active substrate for SERS studies of TiO2 as well as nano diamond and TiO2. The photo reduction of AgNO3 and SERS observation can be obtained by simultaneously using the same visible laser excitation. The coexistence of the anatase phase with small admixture of the rutile phase in the TiO2 can be observed using SERS. The carbon structure in the carbon‐containing TiO2 was determined to be sp2 type carbon bonding by SERS. Copyright © 2009 John Wiley & Sons, Ltd.