bluuebunny/crossref_metadata_2025_split huggingface dataset:
Redox Chemistry and Group 10 Metal Complexes of Aromatic Compounds with Bulky Bicyclic Guanidino Groups
Authors: Wild Ute , Kaifer Elisabeth , Himmel Hans‐Jörg 
Published: August 2011

AbstractThe reaction between activated bicyclic tetramethylbisurea and 1,2‐diaminobenzene or 1,2,4,5‐tetraaminobenzene affords new aromatic compounds functionalized with bicyclic guanidino groups. Protonation and redox reactions are carried out to obtain information about the chemical properties of these new guanidines. They are used as chelating ligands in mononuclear and dinuclear group 10 metal (Ni, Pd, and Pt) complexes, which could be interesting for catalytic applications. Initial experiments with a Ni complex showed a moderate activity in olefin oligomerization yielding mostly C6 hydrocarbons.
Synthesis, Electrochemical and Optical Absorption Properties of New Perylene‐3,4:9,10‐bis(dicarboximide) and Perylene‐3,4:9,10‐bis(benzimidazole) Derivatives
Authors: Perrin Lara , Hudhomme Piétrick 
Published: August 2011

AbstractA series of perylene‐3,4:9,10‐bis(dicarboximide) (PBI) and perylene‐3,4:9,10‐bis(benzimidazole) (PTCBI) derivatives that are di‐ or tetra‐substituted at the bay region by electron‐donating or electron‐withdrawing groups have been synthesized as soluble n‐type semiconductors. Optical absorption spectroscopy and electrochemical analysis show that the nature of substitution at the bay region plays a crucial role in the modulation of the electronic properties of these PBI and PTCBI derivatives. Examination of these optical and electrochemical data in the light of energy levels identified by theoretical studies allowed a relationship between the structure and the electronic properties to be established.
Three New 3,6‐Dioxygenated Diketopiperazines from the Basidiomycete Lepista sordida
Authors: Chen Xiang‐Lian , Wu Min , Ti Hui‐Hui , Wei Xiao‐Yi , Li Tai‐Hui 
Published: August 2011

AbstractThree new 3,6‐dioxygenated diketopiperazines, lepistamides A–C (1–3), along with a known compound, diatretol (4), were isolated from the mycelial solid cultures of the basidiomycete Lepista sordida. Their structures were elucidated by spectroscopic means. The isolated diketopiperazines were evaluated for the cytotoxic activity against Astc‐a‐1, Bel 7402, and HeLa cell lines, and their biogenetic pathway was discussed.
The Rearrangement of 2,2‐Diphenyl‐1‐[(E)‐2‐phenylethenyl]cyclopropane to 3,4,4‐Triphenylcyclopent‐1‐ene: a DFT Analysis
Authors: Sicking Willi , Sustmann Reiner , Mulzer Johann , Huisgen Rolf 
Published: August 2011

AbstractA computational study on the rearrangement of 2,2‐diphenyl‐1‐[(E)‐2‐phenylethenyl]cyclopropane (1) is presented, using density functional theory (DFT), (U)B3LYP with the 6‐31G* basis set (DFT1) and (U)M05‐2X with the 6‐311+G** basis set (DFT2). In agreement with a biradical character of the transition structure (TS) or intermediate, the potential‐energy hypersurface is lowered by the influence of three conjugated Ph groups. Surprisingly, two conformations of the geminal diphenyl group (different twist angles) induce two different minimum‐energy pathways for the rearrangement. Independent of the functional used, the first hypersurface harbors true biradical intermediates, whereas the second energy surface is a flat, slightly ascending slope from the starting material to the TS. The functional (U)M05‐2X with the basis set 6‐311+G** provides realistic energies which seem to be close to experiment. The activation energy for racemization of enantiomers of 1 is lower than that of rearrangement by 2.5 kcal mol−1, in agreement with experiment.
Calvaria bone chamber—A new model for intravital assessment of osseous angiogenesis
Authors: Sinikovic Branko , Schumann Paul , Winkler Meike , Kuestermeyer Julian , Tavassol Frank , von See Constantin , Carvalho Carlos , Mülhaupt Rolf , Bormann Kai‐Hendrik , Kokemueller Horst , Meyer‐Lindenberg Andrea , Laschke Matthias W. , Menger Michael D. , Gellrich Nils‐Claudius , Rücker Martin 
Published: August 2011

AbstractThe faith of tissue engineered bone replacing constructs depends on their early supply with oxygen and nutrients, and thus on a rapid vascularization. Although some models for direct observation of angiogenesis are described, none of them allows the observation of new vessel formation in desmal bone. Therefore, we developed a new chamber model suitable for quantitative in vivo assessment of the vascularization of bone substitutes by intravital fluorescence microscopy. In the parietal calvaria of 32 balb/c mice a critical size defect was set. Porous 3D‐poly(L‐lactide‐co‐glycolide) (PLGA)‐blocks were inserted into 16 osseous defects (groups 3 and 4) while other 16 osseous defects remained unequipped (groups 1 and 2). By placing a polyethylene membrane onto the dura mater, the angiogenesis was mainly restricted to the osseous margins (groups 2 and 4). Microvascular density, angiogenesis, and microcirculatory parameters were evaluated repetitively during 22 days. In all animals, only a mild inflammatory reaction was observed with a climax after 2 weeks. The implantation of PLGA scaffolds resulted in a vascular growth directed towards the center of the defect as demonstrated by the significantly (p < 0.05) enhanced central microvascular densitiy from day 3 to day 22 when compared with unequipped chambers. The additional application of polyethylene membrane was found to reduce significantly the microvessel density mainly in the center of both scaffolds and defects. The present calvaria bone chamber allows for the first time to assess quantitatively the angiogenesis arising from desmal bone directly in vivo. Therefore, this chronic model may support the future research in the biological adequacy of bone substitutes. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part A:, 2011.
The biocompatibility and antimicrobial activity of nanocomposites from polyurethane and nano silicate platelets
Authors: Tseng Hsiang‐Jung , Lin Jiang‐Jen , Ho Tung‐Tso , Tseng Sheng‐Mao , Hsu Shan‐hui 
Published: August 2011

AbstractNanocomposites from a polyether‐type waterborne polyurethane (PU) and 0.1 wt % of silicate materials were prepared. The individual silicate materials were natural clays (montmorillonite and mica), their exfoliated clays [nano silicate platelets (NSP) and nano mica platelets], and NSP modified with C18 fatty amine (NSP‐S). The physico‐chemcical properties and antimicrobial activity of the nanocomposites were characterized in
vitro. The biostability and biocompatibility of the nanocomposites were evaluated in vivo. The nanocomposites exhibited various surface morphologies with phase separation of hard and soft domains in nanometric scales. The nanocomposite containing NSP (PU‐NSP) showed better endothelial cell attachment and gene expression. The better biocompatibility of PU‐NSP and PU‐NSP‐S was evidenced by the lower thickness of foreign body capsules in rat subcutaneous implantation. PU‐NSP had the least surface degradation in vivo as demonstrated by the electron microscopy and infrared spectroscopy. This may be associated with the different surface structure. PU‐NSP and PU‐NSP‐S showed strong bacteriostatic effects, which suggested that the nano clay in the polymer matrix may still interact with the microbes. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part A:, 2011.
Maintenance of hepatic differentiation by hepatocyte attachment peptides derived from laminin chains
Authors: Kikkawa Yamato , Kataoka Akira , Matsuda Yuji , Takahashi Naoya , Miwa Takahiro , Katagiri Fumihiko , Hozumi Kentaro , Nomizu Motoyoshi 
Published: August 2011

AbstractHepatocytes rapidly lose hepatic functions upon isolation from liver, perhaps due to disrupted cell/matrix interactions. The matrix macromolecule laminin‐111 consists of three chains, α1, β1, and γ1; it is a major component of Matrigel, which can maintain hepatic differentiation. We previously showed that the A13 peptide (RQVFQVAYIIIKA, α1 chain 121–133) derived from mouse laminin α1 exhibits hepatocyte attachment activity and maintains hepatic differentiation. Here, we sought to identify hepatocyte adhesive sequences from the mouse laminin β1 and γ1 chains using 22 synthetic peptides that show biological activity for fibrosarcoma cells. Nine peptides showed hepatocyte attachment activity. Of these, B160 (VILQQSAADIAR, β1 chain 1607–1618), and C16 (KAFDITYVRLKF γ1 chain 139–150) exhibited the most potent activity. Hepatocytes cultured on both peptides also maintained expression of albumin, tyrosine aminotransferase, tryptophan‐2,3‐dioxygenase, and cytochrome P450. The morphology of hepatocytes on both peptides was a rounded shape typical for hepatic differentiation. We also characterized the nature of adhesion to the peptides. Heparin and EDTA inhibited cell attachment to both peptides, suggesting that hepatocyte attachment to the peptides was mediated by multiple receptors. The identification of active sequences regulating hepatic functions may facilitate the design of hepatocyte culture substrata that can regulate specific cellular behaviors in the context of a bioartificial liver. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part A:, 2011.
The effects of surface and biomolecules on magnesium degradation and mesenchymal stem cell adhesion
Authors: Liu Huinan 
Published: August 2011

AbstractA novel class of biodegradable metals, magnesium (Mg) and Mg‐based alloys, has recently attracted much attention because of unique biodegradation and mechanical properties for medical applications. Ideally, Mg‐based devices should degrade no faster than the degradation products can be eliminated efficiently from the body. Additionally, for orthopedic and maxillofacial applications, the implant integration with the surrounding bone is critical for its clinical success. Therefore, it is necessary to thoroughly characterize Mg surface and degradation and investigate how these characteristics influence its interactions with essential cells, for example, bone marrow derived mesenchymal stem cells. The objectives of this study were to investigate (1) the effects of two surface conditions (the presence vs. absence of surface oxides) on Mg degradation and mesenchymal stem cell adhesion, and (2) the effects of two essential aqueous environments (the presence vs. absence of physiological ions and proteins) on Mg degradation. In an effort towards standardizing testing methods for Mg alloys, consistent and well‐controlled experimental methods were designed to characterize the surface and degradation of Mg and its interactions with cells. The results demonstrated that original surface (oxidized vs. polished) conditions had a less pronounced effect on regulating initial cell adhesion, but did affect surface morphology and composition of the Mg samples after 24 h of cell culture. The presence versus absence of biological ions and proteins had a significant effect on Mg degradation mode and rate. In conclusion, the material surface and anatomical sites of implantation dependent on the intended applications must be carefully considered while assessing Mg alloys in vitro or in vivo for medical applications. Standardized testing procedures and methods are critically needed for developing more effective medical‐grade Mg alloys. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part A:, 2011.
Uterine and chorioallantoic angiogenesis and changes in the uterine epithelium during gestation in the viviparous lizard,niveoscincus conventryi(squamata: scincidae)
Authors: Ramírez‐Pinilla Martha Patricia , Parker Scott L. , Murphy Christopher R. , Thompson Michael B. 
Published: August 2011

AbstractWe used immunofluorescent confocal microscopy and scanning electron microscopy to quantify uterine vascularity and to describe uterine surface morphology during gestation in pregnant females of the lecithotrophic lizardNiveoscincus coventryi. As uterine angiogenesis and epithelial cell morphology are thought to be under progesterone control, we studied the effect of a progesterone receptor antagonist (mifepristone) on uterine and chorioallantoic microvasculature and features of the uterine epithelial surfaces. Although intussuceptive angiogenesis was observed in both, uterine and chorioallantoic, vascular beds during gestation, the only significant increases were in the diameters of the uterine vessels. An ellipsoid vessel‐dense area grows in the mesometrial hemisphere of the developing conceptus, which parallels the expansion of the allantois to form the chorioallantoic placenta. Uterine surface topography changed during gestation. In particular, uterine blood vessels bulge over the luminal surface to form marked ridges on the uterine embryonic hemisphere, especially during the last stage of pregnancy, and ciliated cells are maintained in the embryonic and abembryonic hemispheres but disappear in both the mesometrial and antimesometrial poles. This distinct regionalization of uterine ridges and ciliated cells in the uterine surface and in the shape of the epithelial component of the chorion might be related to the function of both chorioallantoic and yolk sac placentae during gestation. There was no significant difference between females treated with or without mifepristone, which may be related to the partial function of mifepristone as a progestin antagonist and/or with the function and time of action of progesterone in the uterus during gestation inN. coventryi. Differences in the pattern of angiogenesis and uterine surface morphology during gestation among squamates may be related to the functional diversity of the uterine component of the different placentae and probably reflect its diverse evolutionary history. J. Morphol., 2011. © 2011 Wiley Periodicals, Inc.
MR venography of the brain with enhanced vessel contrast using image‐domain high‐pass filtering of the susceptibility phase shift
Authors: Jin Zhaoyang , Xia Ling , Lou Min , Zhang Minming , Du Yiping P. 
Published: August 2011

AbstractPurpose:To develop a postprocessing algorithm that enhances the visibility of intracranial venous vasculature and reduces the artifacts in the display of susceptibility‐weighted images (SWI).Materials and Methods:Image‐domain high‐pass filters based on second‐order phase difference were applied to the complex 3D SWI data to enhance the susceptibility phase shift of the veins and suppress background signal in SWI. A multivariant statistical parameter was used to suppress the noise in air.Results:Magnetic resonance (MR) venography with enhanced susceptibility phase shift and reduced off‐resonance artifacts was obtained using the proposed filters. The background signal in the 3D MR venography data was well suppressed. Venous vasculature in the peripheral regions of the brain was well depicted and the adverse effect of noise in air in the maximum‐intensity projection display of the 3D SWI data was well suppressed.Conclusion:Image‐domain high‐pass filtering with second‐order phase difference provides an alternative display of 3D SWI data with enhanced visibility of the venous vasculature and effective suppression of artifacts. J. Magn. Reson. Imaging 2011;. © 2011 Wiley Periodicals, Inc.
Orienting the Demixion of a Diblock‐copolymer Using 193 nm Interferometric Lithography for the Controlled Deposition of Nanoparticles
Authors: Dirani Ali , Stehlin Fabrice , Dika Ihab , Spangenberg Arnaud , Grumbach Nathan , Gallani Jean‐Louis , Donnio Bertrand , Greget Romain , Begin‐Colin Sylvie , Demortière Arnaud , Soppera Olivier 
Published: August 2011

AbstractDUV interferometric lithography and diblock copolymer self‐organization have successfully been combined to provide a simple and highly collective nanopatterning technique enabling the organization of nanoparticles over several orders of magnitude, from nanometre to millimetre. The nanostructural changes at the surface of the polymer film after thermal annealing have been monitored by AFM and the process parameters optimized for obtaining a long‐range organization of the lamellar domains. In particular, the impact of the annealing conditions and geometric parameters of the substrate patterns have been investigated. The nanopatterns resulting from the lamellar demixion of (PS‐b‐MMA) were used for a controlled deposition of nanoparticles. The affinity of the hydrophobic particles for the PS block was demonstrated, opening new doors towards the preparation of high‐density arrays of nanoparticles with potential applications in data storage.magnified image
The significance of serial histopathology in a residual mass for outcome of intermediate risk stage 3 neuroblastoma
Authors: Marachelian Araz , Shimada Hiroyuki , Sano Hideki , Jackson Hollie , Stein James , Sposto Richard , Matthay Katherine K. , Baker David , Villablanca Judith G. 
Published: August 2011

AbstractBackgroundTo describe the serial histopathology of intermediate risk stage 3 neuroblastoma after chemotherapy, and correlate with residual mass at therapy completion and outcome.ProcedureA retrospective review of intermediate risk stage 3 neuroblastoma patients treated 1989–2005 at Children's Hospital Los Angeles according to CCG 3881 or CCG 3961 protocols was performed, with central review of histopathology, radiology, and surgery.ResultsEighteen patients treated per CCG 3881 (n = 9) or CCG 3961 (n = 9), with including 1 (n = 5), 2 (n = 9), ≥3 (n = 3), or unknown number (n = 1) of surgical procedures were included. At therapy completion, 10 patients had residual tumor: <10% original size (n = 3), >10% original size (n = 6) (5 MIBG avid; 4 with elevated catecholamines), and CT non‐measurable MIBG avid tumor (n = 1). Post‐chemotherapy histology showed tumor regression (n = 4); or maturation with (n = 6) or without (n = 2) Schwannian development. Histologic changes correlated with median tumor shrinkage of 80% (regressing tumors) and <25% (maturing tumors). Tumor size increased in one patient with maturing tumor and Schwannian development. Overall survival was 100%.ConclusionPost‐chemotherapy histopathology of intermediate risk stage 3 neuroblastoma was characterized by regression or maturation. Persisting residual and maturing tumors were not associated with tumor progression, despite MIBG uptake and/or elevated catecholamines, supporting observation only. Histopathology should be obtained in future studies to confirm these findings, and guide length of chemotherapy. Pediatr Blood Cancer 2012; 58: 675–681. © 2011 Wiley Periodicals, Inc.
Initial testing (stage 1) by the pediatric preclinical testing program of RO4929097, a γ‐secretase inhibitor targeting notch signaling
Authors: Kolb E. Anders , Gorlick Richard , Keir Stephen T. , Maris John M. , Lock Richard , Carol Hernan , Kurmasheva Raushan T. , Reynolds C. Patrick , Kang Min H. , Wu Jianrong , Houghton Peter J. , Smith Malcolm A. 
Published: August 2011

AbstractRO4929097 is a potent and selective inhibitor of γ‐secretase and as a result is able to inhibit Notch pathway signaling. The activity of RO4929097 was evaluated against the in vivo panels of the Pediatric Preclinical Testing Program (PPTP). RO4929097 induced significant differences in event‐free survival (EFS) distribution compared to control in 6 of 26 (23%) of the evaluable solid tumor xenografts and in 0 of 8 (0%) of the evaluable ALL xenografts. The most consistent tumor growth delay effects were noted in the osteosarcoma panel. RO4929097 at the dose and schedule evaluated demonstrated little antitumor activity against childhood cancer xenografts. Pediatr Blood Cancer 2012; 58: 815–818. © 2011 Wiley Periodicals, Inc.
TP53 codon 72 polymorphisms in favorable histology Wilms tumors
Authors: Cost Nicholas G. , Mitui Midori , Khokhar Shama , Wickiser Jonathan E. , Baker Linda A. , Rakheja Dinesh 
Published: August 2011

AbstractIn Wilms tumor (WT), mutations in the gene encoding p53, TP53, are correlated with anaplasia; however TP53 variants have not been studied in favorable histology (FH) WTs. A single nucleotide polymorphism of TP53 encoding either arginine or proline at codon 72 is suggested to alter in vitro p53 behavior. Therefore, we analyzed tissue from 23 consecutive patients with FHWT to determine allelic and genotypic frequencies of Pro72 and Arg72 variants and correlate this with clinical outcomes. Interestingly, our cohort showed a statistically significant over‐representation of the Arg allele and Arg/Arg genotype. However, the genotypic and allelic frequencies showed no significant correlation with age, stage, or disease recurrence. Pediatr Blood Cancer 2012;59:326–328. © 2011 Wiley Periodicals, Inc.
Fabrication of Silicon/Polymer Composite Nanopost Arrays and Their Sensing Applications
Authors: Li Yunfeng , Zhang Junhu , Fang Liping , Wang Tieqiang , Zhu Shoujun , Li Yang , Wang Zhanhua , Zhang Liang , Cui Liying , Yang Bai 
Published: August 2011

AbstractA novel technique is reported for fabricating silicon/polymer composite nanopost arrays by combining colloidal lithography and surface‐initiated atom‐transfer radical polymerization. The composite nanopost arrays possess a core/shell nanoarchitecture, with shells of poly(2‐hydroxyethyl methacrylate) and cores of silicon nanoposts. The polymer brush possesses quasi‐3D homogeneous nanoarchitectures due to the controllable polymerization process using the surface‐initiated atom‐transfer radical polymerization technique. The composite nanopost arrays are durable due to the particular nanoarchitectures. The backbone templates of the composites are silicon nanopost arrays directly etched from silicon substrates, and the polymer shell is covalently grafted from the arrays. The composite nanopost arrays exhibit vivid colors. Moreover, the colors of the composite nanopost arrays can be tuned from green to red by changing the thickness of film. Specifically, the composite nanopost arrays can be used as sensors to rapidly detect water vapors with high stability and reproducibility. Many different functional surfaces could be prepared through this technique using other functional monomers.
Effects of Water Molecules on Photoluminescence from Hierarchical Peptide Nanotubes and Water Probing Capability
Authors: Wang Minjie , Xiong Shijie , Wu Xinglong , Chu Paul K. 
Published: August 2011

AbstractPhotoluminescence (PL) spectra reveal that deficiency of water molecules in the channel cores of bioinspired hierarchical diphenylalanine (L‐Phe‐L‐Phe, FF) peptide nanotubes (PNTs) not only modifies the bandgap of the subnanometer crystalline structure formed by the self‐assembly process, but also induces a characteristic ultraviolet PL peak the position of which is linearly proportional to the number of water molecules in the PNTs. Addition or loss of water molecules gives rise to the UV PL redshift or blueshift. Density functional theory calculation also confirms that addition of water molecules to the PNTs causes splitting of the valence‐band peak, which corresponds to the shift and splitting of the observed UV PL peak. Water molecules play an important role in the biological properties of FF PNTs and the results demonstrate that the PL spectra can be used to probe the number of water molecules bonded to the FF molecules.