bluuebunny/crossref_metadata_2025_split huggingface dataset:
Stability for large forbidden subgraphs
Authors: Nikiforov Vladimir 
Published: March 2009

AbstractIn this note we strengthen the stability theorem of Erdős and Simonovits. Write Kr(s1, …, sr) for the complete r‐partite graph with classes of sizes s1, …, sr and Tr(n) for the r‐partite Turán graph of order n. Our main result is:For all r≥2 and all sufficiently small c>0, ε>0, every graph G of sufficiently large order n with e(G)>(1−1/r−ε)n2/2 satisfies one of the conditions:

G contains a
\documentclass{article} \usepackage{amssymb}\footskip=0pc\pagestyle{empty} \begin{document} $K_{r+1} (\lfloor c\,\mbox{ln}\,n \rfloor,\ldots,\lfloor c\,\mbox{ln}\,n \rfloor,\lceil n^{{1}-\sqrt{c}}\rceil)$ \end{document};
G differs from Tr(n) in fewer than (ε1/3+c1/(3r+3))n2 edges.
Letting µ(G) be the spectral radius of G, we prove also a spectral stability theorem:For all r≥2 and all sufficiently small c>0, ε>0, every graph G of sufficiently large order n with µ(G)>(1−1/r−ε)n satisfies one of the conditions:

G contains a \documentclass{article} \usepackage{amssymb}\footskip=0pc\pagestyle{empty} \begin{document} $K_{r+1}(\lfloor c\,\mbox{ln}\,n\rfloor,\ldots,\lfloor c\,\mbox{ln}\,n\rfloor,\lceil n^{1-\sqrt{c}}\rceil)$ \end{document};
G differs from Tr(n) in fewer than (ε1/4+c1/(8r+8))n2 edges.
© 2009 Wiley Periodicals, Inc. J Graph Theory 62: 362–368, 2009
A novel microwave‐assisted green synthesis of condensed 2‐substituted‐pyrimidin‐4(3H)‐ones under solvent‐free conditions
Authors: Jain Kishor S. , Bariwal Jitender B. , Phoujdar Manisha S. , Nagras Madhuri A. , Amrutkar Rakesh D. , Munde Manoj K. , Tamboli Riyaj S. , Khedkar Samrat A. , Khiste Rahul H. , Vidyasagar Nikhil C. , Dabholkar Vinit V. , Kathiravan M. K. 
Published: March 2009

Abstract
magnified imageA rapid microwave‐assisted green chemical synthesis of condensed 2‐substituted‐pyrimidin‐4(3H)‐ones 3, 4, and 5 involving the condensation of a variety of nitriles with o‐aminoesters of thiophene 2a, 2b, 2c, 2d, 2e, benzene 2f, dimethoxybenzene 2g and quinazolinone 2h in the presence of catalytic amount of HCl alone or with the Lewis acid AlCl3 under solvent‐free conditions, is described for the first time. This novel and clean one‐pot methodology, which is characterized by very short reaction times and easy workup procedures, can be exploited to generate a diverse library of condensed pyrimidine heterocycles. J. Heterocyclic Chem., (2009)
New functionalized N‐heterocyclic carbene ligands for arylation of benzaldehydes
Authors: Doğan Öznur , Gürbüz Nevin , Özdemir İsmail , Çetinkaya Bekir 
Published: March 2009

Abstract
magnified imageNovel functionalized 1,3‐dialkylimidazolinium salts (LHCl) as NHC precursors have been prepared and successfully applied in palladium‐catalyzed arylation of benzaldehydes. The ortho position of aromatic aldehydes was directly and selectively arylated with aryl chlorides in the presence of a catalytic system prepared in situ from Pd(OAc)2, 1,3‐dialkylimidazolinium chlorides (2a, 2b, 2c), and Cs2CO3. J. Heterocyclic Chem., (2009)
Synthesis of the hypotensive agent 8‐amino‐7‐[2‐hydroxy‐3‐morpholinopropyl]theophylline (P23) and analogs
Authors: Cegla Marek T. , Potaczek Joanna , Zylewski Marek , Strekowski Lucjan 
Published: March 2009

Abstract
magnified imageSynthesis of a number of 7,8‐disubstituted theophyllines including enantiomers of the hypotensive agent P23 is described. J. Heterocyclic Chem., (2009)
Meta‐substituent effects on organoiridium‐catalyzed ortho‐hydrogen isotope exchange
Authors: Heys J. Richard , Elmore Charles S. 
Published: March 2009

AbstractReports in the literature appear to differ on the effects of some C3 substituents on the relative efficiencies of isotope exchange in the nonidentical C2‐ and C6‐positions catalyzed by organoiridium complexes. Controlled experiments were conducted using a set of model substrates in attempts to clarify these effects. The results clearly showed that, in common with most previous findings, alkyl substituents at C3 reduced the rate of isotope incorporation into C2 relative to C6, as expected on steric grounds. In contrast, all substituents possessing electron lone pairs resulted in a lessening of the inhibition of C2‐vs‐C6 labeling or promoted C2 labeling to such a degree that it became faster than that at C6. NMR measurements on equimolar mixtures of active iridium complex with selected substrates revealed that the ratios of C2‐ and C6‐iridacycles present in solution correlated with the relative rates of ortho‐deuteration in the rate studies. The results of the two studies, taken together, suggest that conventional explanations for the origin of the positive meta‐effect may not be adequate for the present system. An alternative hypothesis is advanced. Copyright © 2009 John Wiley & Sons, Ltd.
Efficient syntheses of isotopically labeled PD0198961, a novel synthetic coagulation factor Xa inhibitor
Authors: Zhang Yinsheng 
Published: March 2009

AbstractPD0198961 was investigated as a potent and selective inhibitor of coagulation factor Xa for the treatment of thrombotic disorders. Radioactive and stable isotope‐labeled PD0198961 were synthesized for absorption, distribution, metabolism and elimination studies of the compound in animals and for use as mass spectral internal standards in support of bioanalytical assays, respectively. [14C]PD0198961 was prepared from [14C]CuCN in four radiosynthetic steps in an overall yield of 48% with a radiochemical purity of >99%. The cyanation reaction of an aromatic bromide with inorganic [14C]cyanide as a key radiolabeling step was investigated. The deuterium‐labeling was accomplished in a different reaction sequence from the 14C labeling. This convergent process introduced stable isotope labeling via cis‐2,6‐dimethyl[2H5]piperidine, which was synthesized by catalytic hydrogenation of 2,6‐dimethylpyridine with deuterium gas. Copyright © 2009 John Wiley & Sons, Ltd.
A climatology of warm‐season mesoscale convective complexes in subtropical South America
Authors: Durkee Joshua D. , Mote Thomas L. 
Published: March 2009

AbstractThis study extends investigations of mesoscale convective complexes (MCCs) over subtropical South America (SSA) by describing the physical characteristics of MCCs during the austral warm season (October–May) for 1998–2007 in SSA. Within the nine warm seasons, 330 events were documented. An average of 37 MCCs occurred each warm season and reached a maximum cloud‐shield size of 256 500 km2, and lasted 14 h on average. Although 85% of the MCC population occurred over the South American continent, the remaining systems that occurred over the adjacent Atlantic Ocean were significantly larger by nearly 30%. These findings show MCCs in SSA are larger and longer‐lived than shown in previous work. Compared to the United States, MCCs in SSA are significantly larger with longer durations. Unlike the US systems, these events do not exhibit much poleward migration throughout the warm season. The highest frequency and concentration of MCC cloud shields are centred east of the Andes Mountains between 20°S and 30°S over Paraguay, northern Argentina, and southern Brazil throughout the warm season. As a result, relationships between latitude, and MCC maximum extent or duration are weak or non‐existent, respectively. There is, however, a moderate positive relationship between duration and maximum extent. Ultimately, MCCs in SSA are large, long‐lasting events that possess great potential for contributing significantly to precipitation totals across the region. Copyright © 2009 Royal Meteorological Society
T1 glottic carcinoma involving the posterior commissure
Authors: Shvero Jacob , Shvili Itzhak , Mizrachi Aviram , Shpitzer Thomas , Nageris Benny , Koren Rumelia , Hadar Tuvia 
Published: March 2009

AbstractObjectives/Hypothesis:The posterior commissure is an uncommon site of glottic carcinoma. The aim of the study was to compare the clinical and prognostic characteristics of glottic carcinoma of the posterior commissure and the vocal cords.Study Design:Retrospective case control study.Methods:The study group consisted of 40 patients aged 32 to 84 years (mean, 62.7 ± 10.7) diagnosed with T1 glottic carcinoma involving the posterior commissure from 1960 to 2008. Data on clinical features and outcome were collected from the medical files and compared with the data for 42 patients aged 30 to 87 years (mean, 64.4 ± 11.8) with T1 vocal cord carcinoma.Results:There were no significant differences in clinical characteristics between the groups except for the higher rate of smokers among the patients with vocal cord carcinoma (95% vs. 65%, P = .01). All patients were treated primarily with radiotherapy. Disease‐free survival in the posterior commissure carcinoma group was 76.1% after 5 years and 72.3% after 10 years, and in the vocal cord carcinoma group, 95% after 5 and 10 years (P = .012). The risk of recurrence was higher when the tumor involved the posterior commissure (hazard ratio, 8.78; 95% CI, 1.12–68.5, P = .038).Conclusions:T1 glottic carcinoma involving the posterior commissure has a more aggressive biological behavior and a worse prognosis than T1 glottic carcinoma of the vocal cords. Smoking, which is an important pathogenetic factor in vocal cord carcinoma, plays a lesser role in posterior commissure carcinoma. Laryngoscope, 2009
Photon‐echo quantum memory in solid state systems
Authors: Tittel W. , Afzelius M. , Chaneliére T. , Cone R.L. , Kröll S. , Moiseev S.A. , Sellars M. 
Published: March 2009

AbstractMany applications of quantum communication crucially depend on reversible transfer of quantum states between light and matter. Motivated by rapid recent developments in theory and experiment, we review research related to quantum memory based on a photon‐echo approach in solid state material with emphasis on use in a quantum repeater. After introducing quantum communication, the quantum repeater concept, and properties of a quantum memory required to be useful in a quantum repeater, we describe the historical development from spin echoes, discovered in 1950, to photon‐echo quantum memory. We present a simple theoretical description of the ideal protocol, and comment on the impact of a non‐ideal realization on its quantum nature. We extensively discuss rare‐earth‐ion doped crystals and glasses as material candidates, elaborate on traditional photon‐echo experiments as a test‐bed for quantum state storage, and describe the current state‐of‐the‐art of photon‐echo quantum memory. Finally, we give a brief outlook on current research.
Experimental and numerical analyses of diffusion bonded hollow sphere structures
Authors: Winkler R. , Merkel M. , Öchsner A. 
Published: March 2009

AbstractThe reduction of N&V (noise and vibration) is a progressively more important objective for designers of various engineering applications. When a series of physical and mechanical requirements are touched, classic materials reach their limits. Cellular metals with their great diversity of properties open up new vistas. Metallic hollow sphere structures (MHSS) feature a new group of advanced composite materials characterised by high geometrical reproducibility leading to stable properties. In the scope of this study, vibrational analysis of sintered metallic hollow sphere structures is performed. The objective is a description of the dynamic response by numerical simulation. A detailed finite element model would exceed available resources. Therefore, a proper model with special descriptions for hollow spheres and interconnections has been developed and is presented in detail. Numerical results are compared with vibrations measured by laser scanning vibrometer and analytical analysis.
Computed tomography based finite element analysis of the thermal properties of cellular aluminium
Authors: Fiedler T. , Solórzano E. , Garcia‐Moreno F. , Öchsner A. , Belova I.V. , Murch G.E. 
Published: March 2009

AbstractThis work addresses the thermal finite element analysis (FE) of cellular aluminium with irregular pore structures. The used finite element models are generated with computed tomography (CT) images as a basis. Three‐dimensional brick elements of cubic shape are used. The material properties of each element are thereby defined based on corresponding pixels in computed tomography images. The proposed analysis with mapping of material properties on a regular finite element mesh is first validated on simple two dimensional models of regular geometries. The obtained results are compared to highly accurate reference solutions and analytical predictions. Subsequently, the FEM thermal analysis of closed cell Alporas® aluminium foam and open cell M‐Pore® aluminium sponge is carried out determining the effective thermal conductivities of these materials in three perpendicular directions in order to investigate the anisotropic properties of both structures. The variability in the material volume (due to meso‐inhomogeneities) has been inspected by computing different sub‐volumes of the specimens.
Numerical approaches for residual vibration free positioning of elastic robots
Authors: Bachmayer M. , Zander R. , Ulbrich H. 
Published: March 2009

AbstractToday increasing the speed of moving machines with the same or even better precision can often only be realized if flexibilities are taken into account. In order to avoid a stiffer and therefore heavier structure, the flexibility must be considered in the control design. Numerical optimization approaches as well as an analytical feed forward control for linearly actuated robots like placement machines or stacker cranes are presented. These methods help to reduce the time required for positioning in dynamic automation scenarios where the structure’s elasticity is essential for achieving high positioning precision in a minimum of time. Backlash in the gear limits standard closed loop active damping controller’s capabilities in respect to the achievable damping constant. Therefore, feedforward trajectories avoiding residual vibrations are desirable to reduce the positioning time to a structural given limit.
Monitoring of oil leakage from a ship propulsion system using IR camera and wavelet analysis for prevention of health and ecology risks and engine faults
Authors: Kuzmanić I. , Šoda J. , Antonić R. , Vujović I. , Beroš S. 
Published: March 2009

AbstractIt is a well known fact that oil leakage from ship diesel engines is harmful both for the environment and the ship engine and therefore has to be observed and alarmed. The present paper proposes a system for overcoming described problems by installing a computer vision system. The used algorithm of pattern recognition system is based on the use of wavelet structures. Additionally, one of the problems in the system is the compensation of camera movements due to engine vibration. The compensation part of the computer vision solution is used to improve position determination. The position determination is improved more that 300 % when using farras wavelets.
Drop impact analysis of smart unmanned aerial vehicle (SUAV) landing gear and comparison with experimental data
Authors: Kong J.P. , Lee Y.S. , Han J.D. , Ahn O.S. 
Published: March 2009

AbstractThe dynamic behavior of the landing gear is very important, because it absorbs kinetic energy of the vertical load and reduces aircraft impact at touchdown. In this study, drop impact analyses have been conducted for SUAV’s landing gear using the explicit finite element code LS‐DYNA®. The landing gear was modeled as a flexible body and the analyses were focused on the dynamic behavior of the shock absorber, the deformation of the tire, energy analysis and the reaction load on the impact surface. Experimental results were compared with the analytical results.
Mechanical behavior analysis of sintered products of natural rubber crumb rubber (NRCR) using adhesives
Authors: Crespo J. E. , Parres F. , Nadal A. 
Published: March 2009

AbstractIn this work, we began by carrying out an analysis of the mechanical behaviour of sintered Natural Rubber Crumb Rubber (NRCR) optimising the temperature and compression pressure. The results obtained show an improvement in the mechanical properties of the material when the temperature and compression pressure are increased. We then mixed particles of NRCR with different percentages of adhesives with the aim of improving the mechanical performance of the sintered material. The adhesives used in this study were Latex and Polychloroprene, obtaining the best performance for the mixtures with Polychloroprene with a weight percentage of 50 %. The study was completed by an image analysis of the mixtures using a scanning electronic microscope (SEM) in order to observe the NRCR – adhesive reaction.
An anterior‐lateral thigh perforator flap on a recipient brachial‐radial vein graft for complex wound reconstruction: A case report
Authors: Romeo Marco , Cuccia Giuseppe , Manasseri Benedetto , Delia Gabriele , Risitano Giovanni , Spinelli Francesco , D'Alcontres Francesco Stagno , Colonna Michele R. 
Published: March 2009

AbstractA case of challenging microsurgical reconstruction of a difficult defect in a radiated upper limb is reported. A difficult wound, with tendon and bone exposition, developed on the dorsum of the forearm in a 76‐year‐old patient; she had been radiated since almost 50 years and her left hand had also been revascularized twice with venous grafts between the humeral artery and the superficial palmar arch. After failure of a local flap, an anterior‐lateral thigh perforator flap was successfully transferred with end‐to‐side anastomoses on the arterialized venous graft. Up to date follow‐up shows a good outcome. The Authors discuss the case and review the indications for microsurgical reconstruction in difficult wounds after radiation and ischemic limb conditions. © 2009 Wiley‐Liss, Inc. Microsurgery, 2009.
Reverse flow facial artery as recipient vessel for perforator flaps
Authors: Hölzle Frank , Hohlweg‐Majert Bettina , Kesting Marco R. , Mücke Thomas , Loeffelbein Denys J. , Wolff Klaus‐Dietrich , Wysluch Andreas 
Published: March 2009

AbstractIn perforator flaps, anastomosis between flap and recipient vessels in the neck area is often difficult due to small vessel diameter and short pedicle. The aim of this study was to investigate whether the retrograde flow of the distal, paramandibular part of the facial artery would provide sufficient pressure and size to perfuse perforator flaps. Before and after occlusion of the contralateral facial artery, retrograde and anterograde arterial pressure was measured on both sides of the facial artery in 50 patients. The values were compared with the mean systemic arterial pressure. Diameters of facial arteries in the paramandibular region and perforator flap vessels were evaluated by morphometry. Arterial pressure in the distal facial artery with retrograde flow was 76% of the systemic arterial pressure. The latter equaled approximately the anterograde arterial pressure in the proximal end of the facial artery. Mean arterial pressure of the facial arteries decreased after proximal occlusion of the contralateral facial artery, which was not significant (P = 0.09). Mean diameter of the distal facial arteries in the mandibular region was 1.6 mm (range 1.3–2.2 mm; standard deviation 0.3 mm; n = 50), that of the perforator flap arteries 1.3 mm (0.9–2.6 mm; 0.4 mm; n = 20). Facial arteries, based on reverse flow, successfully supported all 20 perforator flaps. Retrograde pulsatile flow in the distal facial artery sustains perforator flaps even if the contralateral facial artery is occluded. Proximity of the distal facial arteries to the defect compensates for short pedicles. Matching diameters of the arteries are ideal for end‐to‐end anastomosis. © 2009 Wiley‐Liss, Inc. Microsurgery, 2009.
Face resurfacing using a cervicothoracic skin flap prefabricated by lateral thigh fascial flap and tissue expander
Authors: Li Qingfeng , Zan Tao , Gu Bin , Liu Kai , Shen Guoxiong , Xie Yun , Weng Rui 
Published: March 2009

AbstractBackground: Resurfacing of facial massive soft tissue defect is a formidable challenge because of the unique character of the region and the limitation of well‐matched donor site. In this report, we introduce a technique for using the prefabricated cervicothoracic skin flap for facial resurfacing, in an attempt to meet the principle of flap selection in face reconstructive surgery for matching the color and texture, large dimension, and thinner thickness (MLT) of the recipient. Materials: Eleven patients with massive facial scars underwent resurfacing procedures with prefabricated cervicothoracic flaps. The vasculature of the lateral thigh fascial flap, including the descending branch of the lateral femoral circumflex vessels and the surrounding muscle fascia, was used as the vascular carrier, and the pedicles of the fascial flap were anastomosed to either the superior thyroid or facial vessels in flap prefabrication. A tissue expander was placed beneath the fascial flap to enlarge the size and reduce the thickness of the flap. Results: The average size of the harvested fascia flap was 6.5 × 11.7 cm. After a mean interval of 21.5 weeks, the expanders were filled to a mean volume of 1,685 ml. The sizes of the prefabricated skin flaps ranged from 12 × 15 cm to 15 × 32 cm. The prefabricated skin flaps were then transferred to the recipient site as pedicled flaps for facial resurfacing. All facial soft tissue defects were successfully covered by the flaps. The donor sites were primarily closed and healed without complications. Although varied degrees of venous congestion were developed after flap transfers, the marginal necrosis only occurred in two cases. The results in follow‐up showed most resurfaced faces restored natural contour and regained emotional expression. Conclusion: MLT is the principle for flap selection in resurfacing of the massive facial soft tissue defect. Our experience in this series of patients demonstrated that the prefabricated cervicothoracic skin flap could be a reliable alternative tool for resurfacing of massive facial soft tissue defects. © 2009 Wiley‐Liss, Inc. Microsurgery, 2009.
Porosity of the wall of a Neurolac® nerve conduit hampers nerve regeneration
Authors: Meek Marcel F. , Den Dunnen Wilfred F. A. 
Published: March 2009

AbstractOne way to improve nerve regeneration and bridge longer nerve gaps may be the use of semipermeable/porous conduits. With porosity less biomaterial is used for the nerve conduit. We evaluated the short‐term effects of porous Neurolac® nerve conduits for in vivo peripheral nerve regeneration. In 10 male Black Hooded rats, a gap of 10 mm was bridged by a porous Neurolac® nerve conduit. Evaluation point ranged from 3 to 12 weeks. The sciatic nerve function was not measurable due to automutilation and flexion contractures. The gait‐stance duration showed no improvement with time, indicating a disturbed walking pattern. The nerve guides showed very fast degradation with swelling, fragmentation, and collapse. Furthermore, a severe foreign body reaction occurred. Nerve regeneration was severely hampered. This study showed no beneficial effects of porous Neurolac® nerve conduits when compared with previous findings with nonporous copolymeric nerve guides of a slightly different composition. © 2009 Wiley‐Liss, Inc. Microsurgery, 2009.