bluuebunny/crossref_metadata_2025_split huggingface dataset:
New Organocadmium Hydrazine Adducts and Hydrazide Complexes
Authors: Johnson Andrew L , Hollingsworth Nathan , Kingsley Andrew , Kociok‐Köhn Gabriele , Molloy Kieran C. 
Published: November 2011

AbstractThe synthesis of (Me2CdL)n [L = H2NN(H)tBu, n = 2 (1); L = H2NN(CH2CH2)2NMe, n = ∞ (2)] and the conversion of 2 to MeCdN(H)N(CH2CH2)2NMe (4) are reported. In the solid state, 1 is a dimer in which each H2NN(H)tBu bridges two metal centres to generate discrete, isolated Cd2N4 rings, whereas 2 is a 1D polymer in which Me2Cd units are bridged by H2N and MeN moieties; the chains in 2 are further reinforced by NH···N hydrogen bonds. Hydrazide 4 is tetrameric and isostructural with the known aminomorpholine analogue; it forms a Cd4N8 cage structure that embodies both five‐membered Cd2N3 and six‐membered Cd2N4 rings. In addition to X‐ray crystallography, 1, 2 and 4 have been characterised by 1H, 13C, and 113Cd NMR spectroscopy.
Composition of neutral lipid classes and content of fatty acids throughout sourdough breadmaking
Authors: Rocha João M. , Kalo Paavo J. , Malcata F. Xavier 
Published: November 2011

AbstractBroa is an example of bread that is a good candidate for inclusion in functional diets, so it deserves further in‐depth study of its chemical composition—namely with regard to evolution of the lipid profile throughout breadmaking, in order to assess whether mixing, fermentation, or baking affect its nutritional value (in terms of unsaturated fatty acids, UFA) based on the assumption that neutral lipids (NL) can be protein‐ or carbohydrate‐bound. Hence, constituent fatty acids in NL of maize (Zea mays) and rye flour (Secale cereale), and in sourdough and final broa manufactured from a mixture therefrom were quantitated. Methodologies of esterification of fatty acids, as well as of transesterification of acyl lipids and sterol esters (SE) were improved. The n‐hydrocarbons containing between 4 and 24 carbon atoms were then resolved and identified by gas–liquid chromatography. Regarding total neutral lipids (TNL) in all samples, 79–89% were TAGs, and 87–93% were TAGs and DAGs in the case of free lipids (FL). Furthermore, 73–85% of TNL in bound lipids (BL) and 65–80% of TNL in starch lipids (SL) were TAG and free fatty acids (FFA). Conversely, only 4–5%, 6–16%, and 7–10% of TNL in FL, BL, and SL, respectively, were SE and MAGs. TAGs and DAGs underwent partial hydrolysis during fermentation and baking; palmitic, oleic, and linoleic acids were dominant as products released. The nutritional value of broa lipids was apparent owing to their proportions of SE (4%) and DAG (9%), coupled with 52% of linoleic acid in all samples—as well as to the high contents of polyunsaturated versus monounsaturated or saturated fatty acids, and to the general dominance of UFA.
Synthesis of N‐Vinyloxazolidinones and Morpholines from Amino Alcohols and Vinylsulfonium Salts: Analysis of the Outcome's Dependence on the N‐Protecting Group by Nanospray Mass Spectrometry
Authors: Yar Muhammad , Fritz Sven P. , Gates Paul J. , McGarrigle Eoghan M. , Aggarwal Varinder K. 
Published: November 2011

AbstractThe effect of the nature of the N‐protecting group on 1,2‐amino alcohols in annulation reactions with diphenylvinylsulfonium triflate has been investigated. Although tosyl and sulfinamide groups give morpholines in high yields, the use of N‐Cbz leads to a high‐yielding synthesis of N‐vinyloxazolidinones. The reactions were monitored by nanospray MS/MS, which revealed why reactions are successful and the fate of reactive intermediates in the unsuccessful reactions.
A new enrichment space for the treatment of discontinuous pressures in multi‐fluid flows
Authors: Ausas Roberto F. , Buscaglia Gustavo C. , Idelsohn Sergio R. 
Published: November 2011

SUMMARYIn this work, a new enrichment space to accommodate jumps in the pressure field at immersed interfaces in finite element formulations, is proposed. The new enrichment adds two degrees of freedom per element that can be eliminated by means of static condensation. The new space is tested and compared with the classical P1 space and to the space proposed by Ausas et al (Comp. Meth. Appl. Mech. Eng., Vol. 199, 1019–1031, 2010) in several problems involving jumps in the viscosity and/or the presence of singular forces at interfaces not conforming with the element edges. The combination of this enrichment space with another enrichment that accommodates discontinuities in the pressure gradient has also been explored, exhibiting excellent results in problems involving jumps in the density or the volume forces. Copyright © 2011 John Wiley & Sons, Ltd.
Epithelia, an Evolutionary Novelty of Metazoans
Authors: Leys Sally P. , Riesgo Ana 
Published: November 2011

AbstractAt the point in animal evolution when cells began to adhere to each other they presumably initially functioned as colonies. The formation of an epithelium that enclosed and controlled an internal milieu would have been the first event to distinguish an individual animal from a colony. To better understand when the first epithelium arose and what its characteristics were, we evaluate the morphological, functional, and molecular characters of epithelia in sponges, considered here the extant representatives of the first metazoans. In particular, we show new claudin‐like sequences from sponges align most closely with sequences from Drosophila that have a barrier function in septate junctions. We also show that type IV collagen, the main component of the basement membrane (BM), is present in calcareous sponges, and we confirm the presence of type IV‐like collagen (spongin short chain collagen) in other sponges. Though in sponges as in other metazoans the epithelium has grades of specialization with varying complexity of junctions and the BM, the main character of a functional epithelium, the ability to seal and control the ionic composition of the internal milieu, is a property of even the simplest sponge epithelium, and therefore the first metazoans likely also had epithelia with these characteristics, which we consider a “true” epithelium. J. Exp. Zool. (Mol. Dev. Evol.) 318B:438–447, 2012. © 2011 Wiley Periodicals, Inc.
Prediction of microvascular invasion of hepatocellular carcinoma: Usefulness of peritumoral hypointensity seen on gadoxetate disodium‐enhanced hepatobiliary phase images
Authors: Kim Kyung Ah , Kim Myeong‐Jin , Jeon Hyae Min , Kim Kyung Sik , Choi Jin‐Sub , Ahn Sang Hoon , Cha Soon Joo , Chung Young Eun 
Published: November 2011

AbstractPurpose:To determine whether peritumoral hypointensity seen on hepatobiliary phase images of preoperative gadoxetate disodium‐enhanced magnetic resonance imaging (EOB‐MRI) is useful for predicting microvascular invasion of hepatocellular carcinoma (HCC).Materials and Methods:This study was approved by the Institutional Review Board. In all, 104 HCC masses in 104 patients who had undergone EOB‐MRI and liver surgery within 1 month after EOB‐MRI were evaluated. Two radiologists independently recorded the presence of a peritumoral hypointensity on hepatobiliary phase. Interobserver agreement was assessed and consensus records were used. Tumor size was measured. A chi‐square test and independent t‐test were used for univariate analysis. Multiple logistic regression was performed to determine factors for predicting microvascular invasion. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of peritumoral hypointensity were calculated.Results:Sixty HCCs had microvascular invasion and 44 did not. Interobserver agreement in determining peritumoral hypointensity was excellent (κ = 0.83). By univariate analysis, peritumoral hypointensity and tumor size were significant for predicting microvascular invasion of HCC. On multiple logistic regression analysis, only peritumoral hypointensity was significant in predicting microvascular invasion of HCC (P = 0.013). The sensitivity, specificity, PPV, and NPV of peritumoral hypointensity were 38.3%, 93.2%, 88.5%, and 52.6%, respectively.Conclusion:Peritumoral hypointensity on the hepatobiliary phase of EOB‐MRI is not sensitive but has high specificity for predicting microvascular invasion of HCC. J. Magn. Reson. Imaging 2012;35:629‐634. © 2011 Wiley Periodicals, Inc.
Transplant‐mediated repair properties of rat olfactory mucosal OM‐I and OM‐II sphere‐forming cells
Authors: Toft Andrew , Tomé Mercedes , Lindsay Susan L. , Barnett Susan C. , Riddell John S. 
Published: November 2011

AbstractOlfactory mucosa is a source of cells for transplant‐mediated repair of spinal cord injury (SCI) and is currently being assessed in clinical trials. We previously reported that olfactory mucosa can generate two types of sphere‐forming cells with stem cell‐like properties. Here we have assessed the repair potential of these cells in a rodent SCI model. Sphere‐forming cells transplanted into a dorsal column injury integrated with the host spinal cord, filling the injury cavity, but showed no evidence of differentiation in vivo. Moreover, transplants supported robust axonal regeneration, particularly when suspensions of smaller spheres, rather than large aggregates, were transplanted. However, tract‐tracing of dorsal column fibers showed that regenerating axons did not extend beyond the transplant. These observations show that undifferentiated olfactory spheres, though capable of supporting axonal regeneration, do not show any advantage over olfactory ensheathing cells isolated from adult olfactory tissue. In addition, olfactory spheres induced a greater astrocytic hypertrophy at the injury site than previously observed for purified olfactory ensheathing cells. © 2011 Wiley Periodicals, Inc.
Long‐term oral administration of glucosamine or chondroitin sulfate reduces destruction of cartilage and up‐regulation of MMP‐3 mRNA in a model of spontaneous osteoarthritis in Hartley guinea pigs
Authors: Taniguchi Shin , Ryu Junnosuke , Seki Masayuki , Sumino Takanobu , Tokuhashi Yasuaki , Esumi Mariko 
Published: November 2011

AbstractHistological and molecular changes were examined to investigate the effects of long‐term administration of glucosamine (GlcN) and chondroitin sulfate (CS) in a model of spontaneous osteoarthritis (OA) in Hartley guinea pigs. Three groups of female 3‐week‐old Hartley guinea pigs received GlcN, CS, and neither agent, respectively. Five animals in each group were sacrificed at 8, 12, and 18 months of age. At 8 months of age, Hartley guinea pigs had severe degeneration of knee joint cartilage, chondrocyte apoptosis, marked reduction of tissue total RNA, decreases of aggrecan and collagen type 2 mRNAs, and increases in MMP‐3 and MMP‐8 mRNAs. Long‐term administration of GlcN and CS reduced cartilage degeneration at 8 months of age. The marked loss of total RNA and the increase in MMP‐3 mRNA were also inhibited by GlcN and CS. Thus, long‐term oral administration of GlcN or CS inhibits OA progression, maintains total RNA and down‐regulates MMP‐3 mRNA in a spontaneous OA model in Hartley guinea pigs. © 2011 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 30:673–678, 2012
Adjuvant imatinib therapy for gastrointestinal stromal tumors
Authors: Pisters Peter W.T. , Colombo Chiara 
Published: November 2011

AbstractSurgery is the standard of care for primary resectable gastrointestinal stromal tumors (GISTs), but half of surgically treated patients relapse. Imatinib (IM) has been shown to prolong recurrence‐free survival after complete surgery and is now approved as adjuvant therapy (400 mg/day) for high‐risk GIST patients. IM is well tolerated, with mild to moderate side effects observed. Whether adjuvant IM prolongs overall survival is under evaluation in two ongoing clinical trials. J. Surg. Oncol. 2011; 104:896–900. © 2011 Wiley Periodicals, Inc.
Low MAD2 expression levels associate with reduced progression‐free survival in patients with high‐grade serous epithelial ovarian cancer
Authors: Furlong Fiona , Fitzpatrick Patricia , O'Toole Sharon , Phelan Sine , McGrogan Barbara , Maguire Aoife , O'Grady Anthony , Gallagher Michael , Prencipe Maria , McGoldrick Aloysius , McGettigan Paul , Brennan Donal , Sheils Orla , Martin Cara , W Kay Elaine , O'Leary John , McCann Amanda 
Published: November 2011

AbstractEpithelial ovarian cancer (EOC) has an innate susceptibility to become chemoresistant. Up to 30% of patients do not respond to conventional chemotherapy [paclitaxel (Taxol®) in combination with carboplatin] and, of those who have an initial response, many patients relapse. Therefore, an understanding of the molecular mechanisms that regulate cellular chemotherapeutic responses in EOC cells has the potential to impact significantly on patient outcome. The mitotic arrest deficiency protein 2 (MAD2), is a centrally important mediator of the cellular response to paclitaxel. MAD2 immunohistochemical analysis was performed on 82 high‐grade serous EOC samples. A multivariate Cox regression analysis of nuclear MAD2 IHC intensity adjusting for stage, tumour grade and optimum surgical debulking revealed that low MAD2 IHC staining intensity was significantly associated with reduced progression‐free survival (PFS) (p = 0.0003), with a hazard ratio of 4.689. The in vitro analyses of five ovarian cancer cell lines demonstrated that cells with low MAD2 expression were less sensitive to paclitaxel. Furthermore, paclitaxel‐induced activation of the spindle assembly checkpoint (SAC) and apoptotic cell death was abrogated in cells transfected with MAD2 siRNA. In silico analysis identified a miR‐433 binding domain in the MAD2 3′ UTR, which was verified in a series of experiments. Firstly, MAD2 protein expression levels were down‐regulated in pre‐miR‐433 transfected A2780 cells. Secondly, pre‐miR‐433 suppressed the activity of a reporter construct containing the 3′‐UTR of MAD2. Thirdly, blocking miR‐433 binding to the MAD2 3′ UTR protected MAD2 from miR‐433 induced protein down‐regulation. Importantly, reduced MAD2 protein expression in pre‐miR‐433‐transfected A2780 cells rendered these cells less sensitive to paclitaxel. In conclusion, loss of MAD2 protein expression results in increased resistance to paclitaxel in EOC cells. Measuring MAD2 IHC staining intensity may predict paclitaxel responses in women presenting with high‐grade serous EOC. Copyright © 2012 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Electrical conductivity studies on water‐soluble polypyrrole–graphene oxide composites
Authors: Basavaraja C. , Kim Won Jung , Thinh P.X. , Huh Do Sung 
Published: November 2011

AbstractPolypyrrole (PPy)–graphene oxide (GO) composites are synthesized via a soft‐chemical in situ method at different GO concentrations (10, 20, 30, 40, and 50 wt%) and with ammonium persulfate (APS) as the oxidant. The synthesized composites were characterized using Fourier transform infrared (FTIR) and ultraviolet‐visible light (UV–vis) spectroscopic studies, and their surface properties were analyzed using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Characterization and surface morphology results indicate that PPy is adsorbed onto the graphene surfaces and/or fills the GO sheets. The temperature‐dependent DC conductivity of the polymer composite films in the 300–500 K range indicates a semiconducting behavior with increasing GO concentration in the PPy polymer. Based on morphological and conductivity studies, the large surface area and high aspect ratio of the in situ‐generated GO may have played an important role in the noticeable improvement in the electrical conductivity of the prepared composites. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers
A study on the crosslink network evolution of nitrile butadiene rubber reinforced by in situ zinc dimethacrylate
Authors: Xu Chuanhui , Chen Yukun , Wang Yanpeng , Zeng Xingrong 
Published: November 2011

AbstractIn this article, we study the evolution of networks based on nitrile butadiene rubber (NBR) which is reinforced by in situ zinc dimethacrylate (ZDMA) during curing. The crosslink density of the composites cured for different time was evaluated by equilibrium swelling experiments. The curing process was analyzed by using a UR‐2030 Rotorless Rheometer. Mechanical properties of the composites cured for different time were also used to evaluate the evolution of the networks. The results reveal that the covalent crosslinked network of NBR is formed rapidly in the early curing stage while the ionic crosslinks grow gradually during the whole curing process. The ionic crosslinks affect much more on the mechanical properties and make the composite easier to achieve inextensibility limit of the network. A sketch for formation of the NBR/ZDMA network was proposed in the last part of this article. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers
Environment‐dependent long‐range structural distortion in a temperature‐sensitive point mutant
Authors: Carey Jannette , Benoff Brian , Harish Balasubramanian , Yuan Lara , Lawson Catherine L. 
Published: November 2011

AbstractExtensive environment‐dependent rearrangement of the helix‐turn‐helix DNA recognition region and adjacent L‐tryptophan binding pocket is reported in the crystal structure of dimeric E. coli trp aporepressor with point mutation Leu75Phe. In one of two subunits, the eight residues immediately C‐terminal to the mutation are shifted forward in helical register by three positions, and the five following residues form an extrahelical loop accommodating the register shift. In contrast, the second subunit has wildtype‐like conformation, as do both subunits in an isomorphous wildtype control structure. Treated together as an ensemble pair, the distorted and wildtype‐like conformations of the mutant apoprotein agree more fully than either conformation alone with previously reported NOE measurements, and account more completely for its diverse biochemical and biophysical properties. The register‐shifted segment Ile79‐Ala80‐Thr81‐Ile82‐Thr83 is helical in both conformations despite low helical propensity, suggesting an important structural role for the steric constraints imposed by β‐branched residues in helical conformation.
Roles of the N‐ and C‐terminal sequences in Hsp27 self‐association and chaperone activity
Authors: Lelj‐Garolla Barbara , Mauk A. Grant 
Published: November 2011

AbstractThe small heat shock protein 27 (Hsp27 or HSPB1) is an oligomeric molecular chaperone in vitro that is associated with several neuromuscular, neurological, and neoplastic diseases. Although aspects of Hsp27 biology are increasingly well known, understanding of the structural basis for these involvements or of the functional properties of the protein remains limited. As all 11 human small heat shock proteins (sHsps) possess an α‐crystallin domain, their varied functional and physiological characteristics must arise from contributions of their nonconserved sequences. To evaluate the role of two such sequences in Hsp27, we have studied three Hsp27 truncation variants to assess the functional contributions of the nonconserved N‐ and C‐terminal sequences. The N‐terminal variants Δ1–14 and Δ1–24 exhibit little chaperone activity, somewhat slower but temperature‐dependent subunit exchange kinetics, and temperature‐independent self‐association with formation of smaller oligomers than wild‐type Hsp27. The C‐terminal truncation variants exhibit chaperone activity at 40 °C but none at 20 °C, limited subunit exchange, and temperature‐independent self‐association with an oligomer distribution at 40 °C that is very similar to that of wild‐type Hsp27. We conclude that more of the N‐terminal sequence than simply the WPDF domain is essential in the formation of larger, native‐like oligomers after binding of substrate and/or in binding of Hsp27 to unfolding peptides. On the other hand, the intrinsically flexible C‐terminal region drives subunit exchange and thermally‐induced unfolding, both of which are essential to chaperone activity at low temperature and are linked to the temperature dependence of Hsp27 self‐association.
A conserved interaction with the chromophore of fluorescent proteins
Authors: Choudhary Amit , Kamer Kimberli J. , Raines Ronald T. 
Published: November 2011

AbstractThe chromophore of fluorescent proteins, including the green fluorescent protein (GFP), contains a highly conjugated imidazolidinone ring. In many fluorescent proteins, the carbonyl group of the imidazolidinone ring engages in a hydrogen bond with the side chain of an arginine residue. Prior studies have indicated that such an electrophilic carbonyl group in a protein often accepts electron density from a main‐chain oxygen. A survey of high‐resolution structures of fluorescent proteins indicates that electron lone pairs of a main‐chain oxygen—Thr62 in GFP—donate electron density into an antibonding orbital of the imidazolidinone carbonyl group. This n→π* electron delocalization prevents structural distortion during chromophore excitation that could otherwise lead to fluorescence quenching. In addition, this interaction is present in on‐pathway intermediates leading to the chromophore, and thus could direct its biogenesis. Accordingly, this n→π* interaction merits inclusion in computational and photophysical analyses of the chromophore, and in speculations about the molecular evolution of fluorescent proteins.
CONTSOR—A new knowledge‐based fold recognition potential, based on side chain orientation and contacts between residue terminal groups
Authors: Vishnepolsky Boris , Pirtskhalava Malak 
Published: November 2011

AbstractRecognizing the structural similarity without significant sequence identity (fold recognition) is an effective method for protein structure prediction. Previously, we developed a fold recognition potential called SORDIS, which incorporated side chain orientation in relation to hydrophobic core centers, distance of the residues from the protein globule center and secondary structure terms. But this potential does not include terms, based on close contacts between residues. In this paper a new fold recognition potential CONTSOR was presented, which based on SORDIS terms and the term, based on contacts between amino acid terminal groups. The performance of this potential was evaluated on SABmark benchmark for alignment accuracy and on SABmark and Lindahl benchmarks for fold recognition. The results show that CONTSOR has the best performance among other potentials on SABmark benchmark both for alignment accuracy and fold recognition and one of the best performances on Lindahl benchmark. CONTSOR software package is available for download at http://www.lifescience.org.ge/downloads/contsor.zip.