bluuebunny/crossref_metadata_2025_split huggingface dataset:
Straightforward Synthesis of Dipyrido‐Annelated NHC‐Palladium(II) Complexes by Oxidative Addition
Authors: Gierz Verena , Seyboldt Alexander , Maichle‐Mössmer Cäcilia , Fröhlich Roland , Rominger Frank , Kunz Doris 
Published: January 2012

AbstractA straightforward synthesis method for mixed phosphane dipyrido‐annelated N‐heterocyclic carbene (dipiy) palladium(II) complexes is presented. The key step is the oxidative addition of 6‐bromodipyridoimidazolium bromides that can be prepared easily from dipyridine in a two step reaction. This new procedure avoids any generation of the free carbene as well as any transmetallation step.
Amide and Urea Ferrocene‐Containing Macrocycles Capable of the Electrochemical Sensing of Anions
Authors: Evans Nicholas H. , Serpell Christopher J. , Christensen Kirsten E. , Beer Paul D. 
Published: January 2012

AbstractTwo novel macrocycles that incorporate the redox‐active ferrocene motif have been synthesized. The amide‐containing macrocycle is capable of sensing basic oxoanions such as dihydrogen phosphate and benzoate despite only exhibiting weak binding of these anions. The second macrocycle, which incorporates urea functionality, is capable of binding and sensing a greater range of anions with a maximum shift of the ferrocene/ferrocenium redox couple of –170 mV observed upon addition of an excess amount of dihydrogen phosphate.
A procedure on ground motion selection and scaling for nonlinear response of simple structural systems
Authors: Ay Bekir Özer , Akkar Sinan 
Published: January 2012

SUMMARYThis study presents a ground‐motion selection and scaling methodology that preserves the basic seismological features of the scaled records with reduced scatter in the nonlinear structural response. The methodology modifies each strong‐motion recording with known fundamental seismological parameters using the estimations of ground‐motion prediction equations for a given target hazard level. It provides robust estimations on target building response through scaled ground motions and calculates the dispersion about this target. This alternative procedure is not only useful for record scaling and selection but, upon its further refinement, can also be advantageous for the probabilistic methods that assess the engineering demand parameters for a given target hazard level. Case studies that compare the performance of the proposed procedure with some other record selection and scaling methods suggest its usefulness for building performance assessment and loss models. Copyright © 2012 John Wiley & Sons, Ltd.
A node‐pair finite element/volume mesh adaptation technique for compressible flows based on a hierarchical approach
Authors: Fossati M. , Guardone A. , Vigevano L. 
Published: January 2012

SUMMARYA grid adaptation technique for two‐dimensional unstructured grids of triangles and quadrilaterals is presented. The error estimation procedure is formulated in terms of a node pair‐based data structure that allows for a unified description of the finite element and finite volume schemes. The adaptation algorithm is based on a strategy of hierarchical corrections, where a suitable number of intermediate adapted grids are generated and successively corrected by employing a simple node insertion technique at the midpoint of the element edges. Coarsening of the grid is obtained in an implicit fashion by avoiding the insertion of new nodes during the correction phase. The adaptation history, from the initial to the current grid, including all intermediate grids, is stored and updated through the whole process. No intermediate grid is therefore required to be stored explicitly. The adapted grid is anisotropic, thanks to the adoption of both regular triangular and quadrilateral elements with high aspect ratio that are gathered in, for example, boundary layer or wake regions. Numerical experiments of steady compressible flows, including both inviscid and viscous flows, are presented to support the suitability of the adaptation technique. Copyright © 2012 John Wiley & Sons, Ltd.
Preoperative imaging and surgical margins in maxillectomy patients
Authors: Kreeft Anne Marijn , Smeele Ludwig E. , Rasch Coen R. N. , Hauptmann Michael , Rietveld Derk H. F. , Leemans C. René , Balm Alfons J. M. 
Published: January 2012

AbstractBackgroundHigh rates of positive surgical margins are reported after a maxillectomy. A large part of tumors that are preoperatively considered “operable” can thus not be resected with tumor‐free margins.MethodsThis was a retrospective study on medical files of 69 patients that underwent maxillectomy as primary treatment for a squamous cell carcinoma.ResultsMore than one third (39%) of all resections performed is incomplete, with dorsal or dorsocranial‐positive surgical margins in two thirds. Correlation of tumor extension on preoperative imaging to surgical margins status revealed that dorsal and cranial tumor extension were significant prognostic factors for tumor positive surgical margins (p = .006 and p = .031, respectively). Positive margins were associated with a 2‐fold increased risk of death (hazard ratio, 2.4; 95% confidence interval, 1.2–4.9).ConclusionCranial or dorsal tumor extension on preoperative imaging was a significant risk factor for positive surgical margins after maxillectomy with significant negative influence on overall survival. © 2012 Wiley Periodicals, Inc. Head Neck, 2012
Flavonoid Constituents from Spiraea brahuica
Authors: Mughal Uzma Rasheed , Mehmood Rashad , Malik Abdul , Ali Bakhat , Tareen Rasool Bakhsh 
Published: January 2012

AbstractSparins A–C (1–3, resp.), three new flavonoids, were isolated from the CHCl3 subfraction of the EtOH extract of the whole plant of Spiraea brahuica, along with 3′,7‐di‐O‐methylquercetin (4) and luteolin 7‐β‐D‐glucopyranoside (5), reported for the first time from this species. The structures of the new compounds were elucidated by spectroscopic techniques including MS and 2D‐NMR spectroscopy.
Aluminium Nitrate Nonahydrate (Al(NO3)3⋅9 H2O): An Efficient Oxidant Catalyst for the One‐Pot Synthesis of Biginelli Compounds from Benzyl Alcohols
Authors: Kolvari Eskandar , Zolfigol Mohammad Ali , Mirzaeean Maryam 
Published: January 2012

AbstractA clean and efficient tandem oxidative cyclocondensation process is reported for the synthesis of 3,4‐dihydropyrimidin‐2(1H)‐one or ‐thione derivatives from primary aryl alcohols, β‐keto esters, and urea or thiourea in the presence of Al(NO3)3⋅9 H2O as oxidant catalyst (Scheme, Table 5).
A One‐Pot Tandem Ugi Multicomponent Reaction (MCR)/Click Reaction as an Efficient Protecting‐Group‐Free Route to 1H‐1,2,3‐Triazole‐Modified α‐Amino Acid Derivatives and Peptidomimetics
Authors: Niu Teng‐Fei , Cai Chun , Yi Lan 
Published: January 2012

AbstractBy a one‐pot tandem Ugi multicomponent reaction (MCR)/click reaction sequence not requiring protecting groups, 1H‐1,2,3‐triazole‐modified Ugi‐reaction products 6a–6n (Scheme 1 and Table 2), 7a–7b (Table 4), and 8 (Scheme 2) were synthesized successfully. i.e., terminal, side‐chain, or both side‐chain and terminal triazole‐modified Ugi‐reaction products as potential amino acid units for peptide syntheses. Different catalyst systems for the click reaction were examined to find the optimal reaction conditions (Table 1, Scheme 1). Finally, an efficient Ugi MCR+Ugi MCR/click reaction strategy was elaborated in which two Ugi‐reaction products were coupled by a click reaction, thus incorporating the triazole fragment into the center of peptidomimetics (Scheme 3). Thus, the Ugi MCR/click reaction sequence is a convenient and simple approach to different 1H‐1,2,3‐triazole‐modified amino acid derivatives and peptidomimetics.
Multicomponent Transformation of Isoindoline‐1,3‐diimine (=1H‐Isoindole‐1,3(2H)‐diimine), Acetylenic Esters, and Triphenylphosphine to Novel Dihydropyrimido[2,1‐a]isoindole Derivatives
Authors: Baharfar Robabeh , Mohajer Saadieh 
Published: January 2012

AbstractThe three‐component reaction of the zwitterions generated from dialkyl acetylenedicarboxylates (=dialkyl but‐2‐ynedioates and triphenylphosphine (Ph3P) with isoindoline‐1,3‐diimine (=1H‐isoindole‐1,3(2H)‐diimine) is described (Scheme 1). This reaction affords the corresponding special type of substituted dihydropyrimido[2,1‐a]isoindole derivatives in good yields without using any catalyst and activation (Table).
New Secondary Metabolites from Asphodelus tenuifolius
Authors: Safder Muhammad , Mehmood Rashad , Ali Bakhat , Mughal Uzma Rasheed , Malik Abdul , Jabbar Abdul 
Published: January 2012

AbstractAsphorins A and B (1 and 2, resp.), two new triterpene glycosides, have been isolated along with a new chromone, 3, from the AcOEt subfraction of the MeOH extract of the whole plant of Asphodelus tenuifolius. Their structures were elucidated by spectral analysis including 2D‐NMR spectroscopic experiments.
IsosteviolProline Conjugates as Highly Efficient Amphiphilic Organocatalysts for Asymmetric Three‐Component Mannich Reactions in the Presence of Water
Authors: An Ya‐Jie , Wang Chuan‐Chuan , Liu Zi‐Ping , Tao Jing‐Chao 
Published: January 2012

AbstractIn this work, six isosteviolamino acid conjugates were designed and synthesized through simple condensation on a large scale without protecting group (Scheme). These amphiphilic organocatalysts mediated asymmetric three‐component Mannich reactions of cyclohexanone and anilines with aromatic aldehydes in the presence of H2O. Meanwhile, the isosteviolproline conjugate 3b has been established as a highly efficient catalyst (Table 1), and afforded syn‐Mannich products with excellent diastereoselectivities (syn/anti up to 98 : 2) and enantioselectivities (up to >99% ee; Table 3). The transition state of the reaction in the presence of H2O is proposed (Fig. 2).
Synthesis of Functionalized Pyrazines and Quinoxalines from Nef‐Isocyanide Adducts and 1,2‐Diamines
Authors: Yavari Issa , Pashazadeh Ramin , Hosseinpour Reza 
Published: January 2012

AbstractAlkyl 3‐(alkylamino)‐5,6‐dicyanopyrazine‐2‐carboxylates and alkyl 3‐(alkylamino)quinoxaline‐2‐carboxylates were obtained in good yields by treatment of Nef‐isocyanide adducts with 1,2‐diamines in MeCN.
Maintenance of redox state and pancreatic beta‐cell function: Role of leptin and adiponectin
Authors: Chetboun Moria , Abitbol Guila , Rozenberg Konstantin , Rozenfeld Hava , Deutsch Avigail , Sampson Sanford R. , Rosenzweig Tovit 
Published: January 2012

AbstractWhereas oxidative stress is linked to cellular damage, reactive oxygen species (ROS) are also believed to be involved in the propagation of signaling pathways. Studies on the role of ROS in pancreatic beta‐cell physiology, in contrast to pathophysiology, have not yet been reported. In this study we investigate the importance of maintaining cellular redox state on pancreatic beta‐cell function and viability, and the effects of leptin and adiponectin on this balance. Experiments were conducted on RINm and MIN6 pancreatic beta‐cells. Leptin (1–100 ng/ml) and adiponectin (1–100 nM) increased ROS accumulation, as was determined by DCFDA fluorescence. Using specific inhibitors, we found that the increase in ROS levels was mediated by NADPH oxidase (Nox), but not by AMP kinase (AMPK) or phosphatidyl inositol 3 kinase (PI3K). Leptin and adiponectin increased beta‐cell number as detected by the XTT method, but did not affect apoptosis, indicating that the increased cell number results from increased proliferation. The adipokines‐induced increase in viability is ROS dependent as this effect was abolished by N‐acetyl‐L‐cysteine (NAC) or PEG‐catalase. In addition, insulin secretion was found to be regulated by alterations in redox state, but not by adipokines. Finally, the effects of the various treatments on activity and mRNA expression of several antioxidant enzymes were determined. Both leptin and adiponectin reduced mRNA levels of superoxide dismutase (SOD)1. Adiponectin also decreased SOD activity and increased catalase and glutathione peroxidase (GPx) activities in the presence of H2O2. The results of this study show that leptin and adiponectin, by inducing a physiological increase in ROS levels, may be positive regulators of beta‐cell mass. J. Cell. Biochem. 113: 1966–1976, 2012. © 2012 Wiley Periodicals, Inc.
Biogenesis, functions and fate of plant microRNAs
Authors: Naqvi Afsar Raza , Sarwat Maryam , Hasan Shirin , Roychodhury Nirupam 
Published: January 2012

AbstractmicroRNAs (miRNAs), a recently discovered class of small RNAs, are endogenously transcribed non‐coding RNAs that are known to control diverse developmental processes and defense responses. They regulate these pathways by fine‐tuning the levels of transcripts to which they bind and cause their cleavage or translation repression. Several studies on the processing of miRNA precursors have shed light on the essential structural features for precise release of miRNA duplexes. The identification of a protein that degrade single stranded small RNA has provided us with some understanding of how miRNA flux is maintained in plants. This review focuses on the genome organization, biogenesis, miRNA activity, and the fate of miRNAs. J. Cell. Physiol. 227: 3163–3168, 2012. © 2012 Wiley Periodicals, Inc.
Histology and histochemistry of the gekkotan notochord and their bearing on the development of notochordal cartilage
Authors: Jonasson Kristin A. , Russell Anthony P. , Vickaryous Matthew K. 
Published: January 2012

AbstractThe persistence of the notochord into the skeletally mature life stage is characteristic of gekkotans, but is otherwise of rare occurrence among amniotes. The taxonomic diversity of Gekkota affords the opportunity to investigate the structure and development of this phylogenetically ancestral component of the skeleton, and to determine its basic characteristics. The gekkotan notochord spans almost the entire postcranial long axis and is characterized by a moniliform morphology with regularly alternating zones of chordoid and chondroid tissue. Chordoid tissue persists in the region of intervertebral articulations and occupies the cavitations that lie between the centra of the amphicoelous vertebrae. Chondroid tissue is restricted to zones in which the diameter of the notochord is reduced, corresponding to mid‐vertebral locations. In the tail, these zones of chondroid tissue are associated with the autotomic fracture planes. Chondroid tissue first manifests during late embryogenesis, appears to differentiate from pre‐existing chordoid tissue, and has the histological and histochemical characteristics of cartilage. Our observations lend support to the hypothesis that cartilage can be derived directly from notochordal tissue, and suggest that the latter may be an evolutionary and developmental precursor to chordate cartilage. The persistence of chordoid tissue in the intervertebral regions of amphicoelous vertebrae is consistent with a suite of paedomorphic traits exhibited by gekkotans and suggests that the typical hydrostatic nature of notochordal tissue may play a role in mechanically governing patterns of displacement between adjacent amphicoelous vertebrae that lack extensive centrum‐to‐centrum contact. Morphol., 2012. © 2012 Wiley Periodicals, Inc.
Analysis of cutoff wavelength of elliptical waveguide by regularized meshless method
Authors: Song Rencheng , Chen Xudong 
Published: January 2012

SUMMARYIn this paper, the regularized meshless method (RMM) combined with the determinant rule is taken to analyze the cutoff wavelength of elliptical waveguide with arbitrary eccentricity. First, an improved desingularization technique of subtracting and adding back is introduced for RMM to discretize this problem. Then, the novel local minimum finding technique on the basis of Chebfun is applied to extract the cutoff wavelength from the determinant of the interpolation matrix of RMM. The numerical examples show that the RMM obtains consistent results with the conventional method of fundamental solutions but has advantage of well‐conditioning and no fictitious boundary. Our method provides another highly effective and stable candidate to solve the cutoff wavelength of elliptical waveguide. Copyright © 2012 John Wiley & Sons, Ltd.
Comprehensive surface‐based morphometry reveals the association of fracture risk and bone geometry
Authors: Wang Defeng , Shi Lin , Griffith James F. , Qin Ling , Yew David T. W. , Riggs Christopher M. 
Published: January 2012

AbstractSurface‐based morphometry method is advantageous in its objectivity and increased capability in detecting focal morphological changes, but has not been applied in bone‐related research. Orthopedics research in human has confirmed the association of the bone geometry in proximal femur and its fracture. In this study, surface‐based morphometry is used to test the hypothesis that there is relationship between bone geometry and fracture risk of the proximal sesamoid bone (PSB) in forelimbs of Thoroughbred racehorses. The PSB surfaces were extracted from CT images of nonfractured forelegs (i.e., right foreleg in this study) of 6 racehorses with fractures in the contralateral (i.e., left) foreleg, and the right forelegs of 6 matched controls. Significant differences were detected at the abaxial margin of the medial PSB base which was found to be up to 3.5 mm more prominent in the fracture‐group compared to the control‐group. This study demonstrated a successful application of computational morphometry in bone. The detected anatomical differences may lead to a larger moment arm generated via the medial branch of the suspensory apparatus, increasing pressure on the sesamoid surface, and thus potentially predisposing to fracture. Findings from this pilot study not only increase the likelihood of accurate PSB fracture risk assessment, but also shed light on investigating the influence of sports and exercise on human athletes. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 30:1277–1284, 2012
Indocyanine green fluorescence‐navigated sentinel node biopsy showed higher sensitivity than the radioisotope or blue dye method, which may help to reduce false‐negative cases in skin cancer
Authors: Fujisawa Yasuhiro , Nakamura Yasuhiro , Kawachi Yasuhiro , Otsuka Fujio 
Published: January 2012

AbstractBackground and ObjectivesAlthough sentinel lymph node (SLN) biopsy using radioisotope (RI) and blue dye (BD) achieved a high detection rate, approximately 5% of melanomas with negative SLNs develop nodal metastasis. We tested a new lymphatic navigation method using indocyanine green fluorescence imaging (ICG‐FI) to detect such “occult” SLNs.MethodsThirty‐four skin cancer patients received SLN biopsy with the following three methods: RI (99Tc‐tin colloid), BD (2% patent blue), and ICG (0.5% indocyanine green). Lymph nodes detected by any of the three methods were counted as SLNs.ResultsICG‐FI detected more SLNs in 8 out of the 34 cases (24%). The average numbers of SLNs detected by ICG‐FI, RI, and BD were 2.18, 1.76, and 1.73, respectively. Interestingly, ICG‐FI not only detected more SLNs in one basin (ICG‐FI: 1.64, RI: 1.50, and BD: 1.51 SLNs per basin), but also detected additional SLNs in other basins (ICG‐FI: 1.32, RI: 1.18, and BD: 1.15 basins per case).ConclusionICG‐FI detected SLNs more efficiently than did the conventional methods, and these “occult” SLNs may offer an explanation for some false‐negative cases. We recommend using ICG‐FI in addition to a conventional method to reduce the risk of overlooking these “occult” SLNs. J. Surg. Oncol. 2012; 106:41–45. © 2012 Wiley Periodicals, Inc.
Solvent effects on the activation parameters of the reaction between an α‐tocopherol analogue and dpph•: The role of H‐bonded complexes
Authors: Foti Mario C. 
Published: January 2012

AbstractThe analysis of the activation parameters for the formal H‐atom transfer reaction between 2,2,5,7,8‐pentamethyl‐6‐chromanol (ChrOH) and 2,2‐diphenyl‐1‐picrylhydrazyl (dpph•) reveals that these parameters are effective probes of the actual reaction mechanism. Indeed, the A factors measured in various polar and apolar solvents are localized in three distinct domains according to whether the reaction occurs via outer‐sphere electron transfer (ET) from the anion ChrO− or hydrogen atom transfer (HAT). For instance, A = 5.9 × 105 M−1 s−1 and Ea = 2.5 kcal mol−1 in cyclohexane where the reaction proceeds by HAT, whereas in methanol, ethanol, and their mixtures with water where there is a substantial ET contribution A > 109 M−1s−1 and Ea > 7 kcal mol−1. Interestingly, in nonhydroxylic polar solvents, A∼ 107 M−1s−1 and the Ea values reflect the H‐bond accepting ability of the solvent in agreement with the “standard” kinetic solvent effects on HAT reactions. Addition of small quantities of pyridine accelerates the reaction rates in these solvents. This suggests that the H‐bonded complex (ChrOH···Py) is able to react via intermolecular ET with dpph•. It is known, in fact, that pyridine lowers the oxidation potential of phenols by ∼0.5 V and the ΔGET of ChrOH + dpph• consequently decreases by about 10 kcal mol−1. © 2012 Wiley Periodicals, Inc. Int J Chem Kinet 44: 524–531, 2012
Transforming growth factor β3 for the prevention of vocal fold scarring
Authors: Ohno Satoshi , Hirano Shigeru , Kanemaru Shin‐ichi , Kitani Yoshiharu , Kojima Tsuyoshi , Ishikawa Seiji , Mizuta Masanobu , Tateya Ichiro , Nakamura Tatsuo , Ito Juichi 
Published: January 2012

AbstractObjectives/Hypothesis:Vocal fold scarring poses a therapeutic challenge. It causes hoarseness and decreases the quality of life. Transforming growth factor β3 (TGFβ3) is highly expressed in fetal wounds that heal without scarring, and administration of TGFβ3 has been reported to prevent scarring of the skin and the buccal mucosa. Thus TGFβ3 is considered to be a key molecule in scar‐free healing. This study aimed to examine the ability of TGFβ3 to prevent vocal fold scarring, with particular attention paid to the distribution of extracellular matrices and functional outcomes.Study Design:Prospective study using an animal model.Methods:Ten beagles were used in this study; 500 μL of TGFβ3 (0.5 μg/mL: 5 beagles) or saline (5 beagles) was injected into the vocal fold lamina propria. Fifteen minutes after injection, vocal folds were injured by stripping off the entire layer of the lamina propria. Six months after surgery, animals were euthanized and the larynges were harvested. Vibratory and histologic examinations were performed.Results:The administration of TGFβ3 suppressed granulation‐tissue formation and scarring. TGFβ3‐treated vocal folds showed significantly better vibratory properties, resembling normal vocal folds. Histologic analysis revealed favorable restoration of elastin and hyaluronic acid in the lamina propria. The distribution of collagen was well organized, and collagen deposition was less dense in TGFβ3‐treated vocal folds compared to sham‐treated vocal folds.Conclusions:Administration of TGFβ3 before injury significantly suppressed scar formation and induced favorable restoration of extracellular matrices in the vocal fold lamina propria, resulting in much improved phonatory function.