bluuebunny/crossref_metadata_2025_split huggingface dataset:
The σ‐Hole Phenomenon of Halogen Atoms Forms the Structural Basis of the Strong Inhibitory Potency of C5 Halogen Substituted Glucopyranosyl Nucleosides towards Glycogen Phosphorylase b
Authors: Kantsadi Anastasia L. , Hayes Joseph M. , Manta Stella , Skamnaki Vicky T. , Kiritsis Christos , Psarra Anna‐Maria G. , Koutsogiannis Zissis , Dimopoulou Athina , Theofanous Stavroula , Nikoleousakos Nikolaos , Zoumpoulakis Panagiotis , Kontou Maria , Papadopoulos George , Zographos Spyros E. , Komiotis Dimitris , Leonidas Demetres D. 
Published: January 2012

AbstractC5 halogen substituted glucopyranosyl nucleosides (1‐(β‐D‐glucopyranosyl)‐5‐X‐uracil; X=Cl, Br, I) have been discovered as some of the most potent active site inhibitors of glycogen phosphorylase (GP), with respective Ki values of 1.02, 3.27, and 1.94 μM. The ability of the halogen atom to form intermolecular electrostatic interactions through the σ‐hole phenomenon rather than through steric effects alone forms the structural basis of their improved inhibitory potential relative to the unsubstituted 1‐(β‐D‐glucopyranosyl)uracil (Ki=12.39 μM), as revealed by X‐ray crystallography and modeling calculations exploiting quantum mechanics methods. Good agreement was obtained between kinetics results and relative binding affinities calculated by QM/MM‐PBSA methodology for various substitutions at C5. Ex vivo experiments demonstrated that the most potent derivative (X=Cl) toward purified GP has no cytotoxicity and moderate inhibitory potency at the cellular level. In accordance, ADMET property predictions were performed, and suggest decreased polar surface areas as a potential means of improving activity in the cell.
NMR Investigation of Imidazolium‐Based Ionic Liquids and Their Aqueous Mixtures
Authors: Cesare Marincola Flaminia , Piras Cristina , Russina Olga , Gontrani Lorenzo , Saba Giuseppe , Lai Adolfo 
Published: January 2012

Abstract1H and 13C NMR spectroscopy is employed to investigate the interaction of water with two imidazolium‐based ionic liquids (ILs), 1‐hexyl‐3‐methylimidazolium bromide ([C6mim]Br) and 1‐octyl‐3‐methylimidazolium bromide ([C8mim]Br), at IL concentrations well above the critical aggregation concentration (CAC). The results are compared with those of the neat samples. To this aim, a detailed analysis of the changes in the 1H chemical shifts, 13C relaxation parameters, and 2D ROESY data due to the presence of water is performed. The results for both neat ILs are consistent with a packed structure where head‐to‐head, head‐to‐tail, and tail‐to‐tail contacts occur and where the site of maximal mobility restriction is at the polar head. At the lowest investigated water content, the presence of water influences mainly the environment around the IL polar head, slowing down the motional dynamics of the aromatic ring with respect to the alkyl chain. At higher water contents this difference diminishes, the motional freedom of the whole molecule increasing. The presence of ROESY cross‐peaks between protons in the polar and apolar IL regions, as well as between protons in non‐neighboring alkyl groups, at all investigated water contents suggests that the alkyl tails are not fully segregated in hydrophobic domains, as expected for micelle‐like structures.
1,2,4‐Oxadiazole 4‐Oxides as Nitrones in 1,3‐Dipolar Cycloaddition Reactions to Vinyl Ethers
Authors: Quadrelli Paolo , Lunghi Fabio , Bovio Bruna , Gautschi William , Caramella Pierluigi 
Published: January 2012

Abstract1,2,4‐Oxadiazole 4‐oxides display nitronic reactivity and selectivities identical to those of N‐methyl‐C‐phenyl nitrone, which is a typical acyclic nitrone, affording comparable amounts of endo‐ and exo‐5‐alkoxyisoxazolidines. The exo stereoisomers undergo an easy rearrangement under the reaction conditions to yield oxadiazolinic esters. The structures of the adducts have been confirmed by X‐ray structures and spectroscopic data. A donor p‐methoxyphenyl at the nitronic carbon slows down the cycloaddition rate, while an acceptor p‐nitrophenyl retards the rearrangement of the exo adduct.
Malleable disc base for direct infiltration measurements using the tension infiltrometry technique
Authors: Moret‐Fernández David , Blanco Nuria , Martínez‐Chueca Victor , Bielsa Ana 
Published: January 2012

AbstractThe correct use of the tension disc infiltrometer requires the membrane of the disc base to be completely in contact with the soil surface. To achieve this contact, a thick layer of sand is commonly placed between the soil surface and the disc base. This paper presents an alternative disc (MDB), which, by incorporating a malleable membrane, allows direct infiltration measurements without using a contact sand layer. Infiltration curves obtained with this new design in a soil under three different tillage management treatments were compared with the corresponding curves obtained with a conventional disc (CDB) that uses a contact sand layer. The cumulative infiltration curves measured with CDB were analysed by the differentiated linearization (DL) method, and the corresponding curves obtained with MDB were analysed using both the DL and the cumulative linearization (CL) models. The values of hydraulic conductivity (K0) and sorptivity (S0) estimated with CDB were also compared with those obtained with MDB. Finally, the cumulative infiltration curves measured with CDB and MDB were compared with the corresponding modelled function for the respective K0 and S0 values calculated with the CL and DL models. The results show that, compared with CDB without a contact sand layer, MDB allows complete soil surface wetting even when non‐smoothed soil surfaces are used. The CDB, which yielded average K0 values 18% lower than those estimated with MDB, gave the highest values of standard error for the hydraulic parameters calculated. Furthermore, the subjective method employed in the CDB‐DL technique, which requires the first points of the differential infiltration line corresponding to the sand layer to be manually removed, introduces additional uncertainties in estimating S0 and K0. Comparison between the modelled and measured infiltration curves demonstrates that the DL or CL methods applied to MDB gave excellent estimates of S0 and K0. Copyright © 2012 John Wiley & Sons, Ltd.
Concentrations and loads of dissolved xenobiotics and hormones in two small river catchments of different land use in Luxembourg
Authors: Krein A. , Keßler S. , Meyer B. , Pailler J.‐Y. , Guignard C. , Hoffmann L. 
Published: January 2012

AbstractThe investigation focuses on the analysis of dissolved sulfonamides, tetracyclines, analgesics, anticonvulsants and hormones in surface water. Runoff event and baseflow samples were analysed in two small river catchments of different land use in Luxembourg. For most of the flood events, similar pollutant loads to those transported during 1 day with average baseflow discharge were observed. The maximum contents during flood events and the event mean concentrations are controlled by pre‐event hydro‐climatological conditions. For all substances under investigation, maximum concentrations and event mean concentrations show a decrease with raising antecedent rainfall. In addition, the interstorm and intrastorm variability of the pollutant transport was determined. Runoff generation and corresponding transport of xenobiotic compounds show a complex pattern with many interrelated processes, taking place within bedrock, soil, anthropogenic facilities and channel and in different parts of the basins under investigation. Different sources of pollutants can be identified and related to particular locations in the basin. The influence of the sewer systems is obvious. In the agricultural Mess basin, higher rainfall amounts lead to greater quantities of laterally inflowing soil water with higher concentrations of dissolved oxytetracycline. This originates from veterinary medicines administered to livestock and enters the environment through the application of organic fertilisers, especially by slurry that is applied to the fields. Copyright © 2012 John Wiley & Sons, Ltd.
Multiparametric MRI maps for detection and grading of dominant prostate tumors
Authors: Moradi Mehdi , Salcudean Septimiu E. , Chang Silvia D. , Jones Edward C. , Buchan Nicholas , Casey Rowan G. , Goldenberg S. Larry , Kozlowski Piotr 
Published: January 2012

AbstractPurpose:To develop an image‐based technique capable of detection and grading of prostate cancer, which combines features extracted from multiparametric MRI into a single parameter map of cancer probability.Materials and Methods:A combination of features extracted from diffusion tensor MRI and dynamic contrast enhanced MRI was used to characterize biopsy samples from 29 patients. Support vector machines were used to separate the cancerous samples from normal biopsy samples and to compute a measure of cancer probability, presented in the form of a cancer colormap. The classification results were compared with the biopsy results and the classifier was tuned to provide the largest area under the receiver operating characteristic (ROC) curve. Based solely on the tuning of the classifier on the biopsy data, cancer colormaps were also created for whole‐mount histopathology slices from four radical prostatectomy patients.Results:An area under ROC curve of 0.96 was obtained on the biopsy dataset and was validated by a “leave‐one‐patient‐out” procedure. The proposed measure of cancer probability shows a positive correlation with Gleason score. The cancer colormaps created for the histopathology patients do display the dominant tumors. The colormap accuracy increases with measured tumor area and Gleason score.Conclusion:Dynamic contrast enhanced imaging and diffusion tensor imaging, when used within the framework of supervised classification, can play a role in characterizing prostate cancer. J. Magn. Reson. Imaging 2012;35:1403–1413. © 2012 Wiley Periodicals, Inc.
Quality improvement of microsurgery through telecommunication—the postoperative care after microvascular transfer of intestine
Authors: Chen Hung‐Chi , Kuo Hsin‐Chih , Chung Kuo‐Piao , Chen Shih‐Heng , Tang Yueh‐Bih , Su Syi 
Published: January 2012

AbstractThe purpose of this report is to describe the use of telecommunication to improve the quality of postoperative care following microsurgery, especially following microvascular transfer of intestinal transfer for which shortening of ischemia time is of utmost importance to achieve high success rate. From 2003 to 2009 microvascular transfer of intestinal flaps had been performed in 112 patients. After surgery the patients were put in intensive care unit and the flaps were checked every 1 hour. The image for circulatory status of the flaps was sent directly to the attending surgeon for judgment. The information was sent through intranet and the surgeon can get access to the intranet through internet if necessary. Among the 112 cases, there were 9 cases of reexploration. The average duration between the time of problem detection and the time of starting reexploration was 54 min in 7 cases, and other 2 cases were delayed to enter the operating room which had been occupied by other cases of major trauma. Only two flaps were lost completely, two patients developed narrowing at the junction of cervical esophagus and thoracic esophagus. The rate of salvage for intestinal flap is apparently higher than those reported in the literature. In the postoperative management of microsurgery in ICU, telecommunication can help to reduce the ischemia time after vascular compromise in the transfer of free intestinal flap. Telecommunication is really an easy and effective tool in improving the outcome of reconstructive surgery. © 2012 Wiley Periodicals, Inc. Microsurgery, 2012.
Single‐stage reconstruction of oral and hypopharyngeal double cancer with a free jejunal flap
Authors: Hirano Takashi , Tateyama Kaori , Kodama Satoru , Takeno Shinsuke , Suzuki Masashi 
Published: January 2012

AbstractMultiple primary tumors are a known phenomenon in head and neck cancer. However, the incidence of simultaneous oral and hypopharyngeal double cancer is extremely rare. In light of this, the surgical treatment for oral and hypopharyngeal double cancer has not been established. Here we present a case of oral and hypopharyngeal double cancer in which we successfully used a free jejunal flap to reconstruct an oral and hypopharyngeal defect. When the oral tumor is limited to the mucosal surface, a single‐stage reconstruction with a free jejunal flap is a suitable option because it is simple and causes less morbidity than using additional flap reconstruction. © 2012 Wiley Periodicals, Inc. Microsurgery, 2012.
Autonomization of free flaps in the oral cavity: A prospective clinical study
Authors: Mücke Thomas , Wolff Klaus‐D. , Rau Andrea , Kehl Victoria , Mitchell David A. , Steiner Timm 
Published: January 2012

AbstractControversy exists over how long a free flap is dependent on its pedicle and if neovascularization is different between flap types, recipient sites, and irradiated and nonirradiated patients. An understanding of the timing of this process should optimize the safety of secondary procedures involving the flap. In a prospective clinical study, hemoglobin oxygenation and capillary flow were measured in 50 flaps (25 forearm flaps, 15 osteocutaneous fibula flaps, and 10 anterolateral thigh flaps) 4 and 12 weeks postoperatively. The flaps were located at the floor of the mouth, cheek, or tongue (n = 39) or at the hard or soft palate (n = 11). Measurements were carried out using the O2C monitoring system under temporary digital occlusion of the pedicle. After 4 weeks, 17 free flaps were found to be autonomized indicated by the O2C measurements comparing both values before and after digital compression of the vascular pedicle. After 12 weeks, 41 patients had completion of free flap autonomization, as indicated by the HbO2 and CF before and after pedicle compression. The location of free flap in the lower jaw (P < 0.0001 after 4 weeks, P = 0.013 after 12 weeks), fasciocutaneous radial forearm flaps after 4 weeks (P < 0.0001), and not irradiated recipient site after 4 weeks (P = 0.014) were found to be positive factors significantly influencing autonomization. In conclusion, free flap autonomization depends on several variables which should be considered before further surgery after free flap reconstruction as the transferred tissue can be still dependent on its pedicle. © 2012 Wiley Periodicals, Inc. Microsurgery, 2012.
An 8‐ to 12‐GHz wideband negative resistance reflection amplifier
Authors: Chan Pak , Fusco V. 
Published: January 2012

AbstractThis article describes the design and characterization of a wideband, 40% bandwidth microwave one port reflection amplifier.Experimental and simulation results are presented. The one port reflection amplifier uses a silicon bipolar transistor and demonstrates a return gain of better than 10 dB from 8 to 11.5 GHz. The gain of the refection amplifier can be easily DC modulated. In addition, a pair of reflection amplifiers is used to create a wideband bidirectional amplifier. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:553–555, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26597
Effect of graphene doping of holographic polymer‐dispersed liquid crystals
Authors: Kim Byung Kyu , Jang Min Woo , Park Hong Chae , Jeong Han Mo , Kim Eun Young 
Published: January 2012

AbstractDoping a polymer matrix with a minute amount of graphene (0.05–0.25%) had significant effects on the grating formation kinetics and electro‐optical performance of a holographic polymer‐dispersed liquid crystal. Low graphene contents (≤0.1%) reduced the viscosity and induced rapid diffusion, curing, grating formation, and high diffraction efficiency with a diffraction overshoot of 0.05%. Conversely, high graphene contents increased the compound viscosity, and the entire process proceeded slowly. Graphene increased the polymer conductivity and local electric field, reduced the operating voltage from 65 to 25–50 V, and increased the contrast ratio from 7 to 8–23 with a concomitant decrease in rise time. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Luminescence quenching of porous silicon nanoparticles in presence of ascorbic acid
Authors: La Ferrara Vera , Fiorentino Giuseppe , Rametta Gabriella , Di Francia Girolamo 
Published: January 2012

AbstractIn this work, the effect of ascorbic acid on luminescence of porous silicon nanoparticles is studied. Porous nanoparticles with a multi‐sized distribution are produced from a porous silicon free standing film and filtered through a 450 nm membrane. The highly luminescent and water‐soluble nanoparticles are dispersed in deionized water. The stability of photoluminescence signal and the dimensions of porous silicon nanoparticles are characterized before adding ascorbic acid into the porous nanoparticles solution. The increasing of photoluminescence, before stabilization, has been correlated to oxidation of nanoparticles in water, evaluated by the technique of Attenuated Total Reflection. Once the nanoparticle photoluminescence signal is stabilized, ascorbic acid is loaded into the solution and its presence and real absorption onto the porous silicon nanoparticles are evaluated from their emission quenching. The quenching of photoluminescence is studied with different concentrations of ascorbic acid by Stern–Volmer plot for confirming the quenching law. This study shows that luminescence quenching of porous nanoparticles could be used for determining the presence of ascorbic acid in a solution.
Induction of Osteogenesis in Mesenchymal Stem Cells by Activated Monocytes/Macrophages Depends on Oncostatin M Signaling
Authors: Guihard Pierre , Danger Yannic , Brounais Bénédicte , David Emmanuelle , Brion Régis , Delecrin Joël , Richards Carl D. , Chevalier Sylvie , Rédini Françoise , Heymann Dominique , Gascan Hugues , Blanchard Frédéric 
Published: January 2012

Abstract
Bone resorption by osteoclasts and bone formation by osteoblasts are tightly coupled processes implicating factors in TNF, bone morphogenetic protein, and Wnt families. In osteoimmunology, macrophages were described as another critical cell population regulating bone formation by osteoblasts but the coupling factors were not identified. Using a high-throughput approach, we identified here Oncostatin M (OSM), a cytokine of the IL-6 family, as a major coupling factor produced by activated circulating CD14+ or bone marrow CD11b+ monocytes/macrophages that induce osteoblast differentiation and matrix mineralization from human mesenchymal stem cells while inhibiting adipogenesis. Upon activation of toll-like receptors (TLRs) by lipopolysaccharide or endogenous ligands, OSM was produced in classically activated inflammatory M1 and not M2 macrophages, through a cyclooxygenase-2 and prostaglandin-E2 regulatory loop. Stimulation of osteogenesis by activated monocytes/macrophages was prevented using neutralizing antibodies or siRNA to OSM, OSM receptor subunits gp130 and OSMR, or to the downstream transcription factor STAT3. The induced osteoblast differentiation program culminated with enhanced expression of CCAAT-enhancer-binding protein δ, Cbfa1, and alkaline phosphatase. Overexpression of OSM in the tibia of mice has led to new bone apposition with no sign of bone resorption. Two other cytokines have also a potent role in bone formation induced by monocytes/macrophages and activation of TLRs: IL-6 and leukemia inhibitory factor. We propose that during bone inflammation, infection, or injury, the IL-6 family signaling network activated by macrophages and TLR ligands stimulates bone formation that is largely uncoupled from bone resorption and is thus an important target for anabolic bone therapies.
Disclosure of potential conflicts of interest is found at the end of this article.
PKA/CREB Signaling Triggers Initiation of Endothelial and Hematopoietic Cell Differentiation via Etv2 Induction
Authors: Yamamizu Kohei , Matsunaga Taichi , Katayama Shiori , Kataoka Hiroshi , Takayama Naoya , Eto Koji , Nishikawa Shin-Ichi , Yamashita Jun K. 
Published: January 2012

Abstract
Ets family protein Etv2 (also called ER71 or Etsrp) is a key factor for initiation of vascular and blood development from mesodermal cells. However, regulatory mechanisms and inducing signals for Etv2 expression have been largely unknown. Previously, we revealed that cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA) signaling enhanced differentiation of vascular progenitors into endothelial cells (ECs) and hematopoietic cells (HPCs) using an embryonic stem cell (ESC) differentiation system. Here, we show that PKA activation in an earlier differentiation stage can trigger EC/HPC differentiation through Etv2 induction. We found Etv2 was markedly upregulated by PKA activation preceding EC and HPC differentiation. We identified two cAMP response element (CRE) sequences in the Etv2 promoter and 5′-untranslated region and confirmed that CRE-binding protein (CREB) directly binds to the CRE sites and activates Etv2 transcription. Expression of a dominant negative form of CREB completely inhibited PKA-elicited Etv2 expression and induction of EC/HPCs from ESCs. Furthermore, blockade of PKA significantly inhibited Etv2 expression in ex vivo whole-embryo culture using Etv2-Venus knockin mice. These data indicated that PKA/CREB pathway is a critical regulator for the initiation of EC/HPC differentiation via Etv2 transcription. This early-stage molecular linkage between a triggering signal and transcriptional cascades for differentiation would provide novel insights in vascular and blood development and cell fate determination.
Disclosure of potential conflicts of interest is found at the end of this article.
Evaluation of the long-term effects of gastric inhibitory polypeptide–ovalbumin conjugates on insulin resistance, metabolic dysfunction, energy balance and cognition in high-fat-fed mice
Authors: Irwin Nigel , Montgomery Ian A. , Flatt Peter R. 
Published: January 2012

The effects of active immunisation with gastric inhibitory polypeptide (GIP) or (proline3)GIP–ovalbumin conjugates on insulin resistance, metabolic dysfunction, energy expenditure and cognition were examined in high-fat-fed mice. Normal mice were injected (subcutaneously) once every 14 d for 98 d with GIP–ovalbumin conjugates, with transfer to a high-fat diet on day 21. Active immunisation resulted in GIP antibody generation and significantly (P < 0·01 to P < 0·001) reduced circulating non-fasting plasma insulin concentrations compared to high-fat control mice from day 70 onwards. The glycaemic responses to intraperitoneal glucose or nutrient ingestion were significantly improved in all treated mice, with corresponding stimulated plasma insulin levels depressed compared to high-fat controls. These changes were associated with substantially (P < 0·001) improved glucose-lowering responses to exogenous insulin and decreases of muscle and fat TAG, pancreatic insulin, circulating total and LDL-cholesterol levels (P < 0·01 to P < 0·001). Treatment with GIP–ovalbumin conjugates was not associated with alterations in energy expenditure, indirect calorimetry or aspects of cognitive function. The observed changes were almost identical in GIP and (Pro3)GIP immunised mice and were independent of any effects on food intake or body weight. Further tests established that coupling of GIP peptides to ovalbumin abolished any intrinsic insulin-releasing or glucose-lowering activity. These results suggest that induction of GIP-neutralising antibodies with GIP–ovalbumin conjugates is an effective means of countering the metabolic abnormalities induced by high-fat feeding and does not adversely have an impact on a marker of cognition function or energy expenditure.