bluuebunny/crossref_metadata_2025_split huggingface dataset:
Solution of Cubic and Quartic Equations
Authors: Riccardi Marco 
Published: July 2009

Solution of Cubic and Quartic Equations
In this article, the principal n-th root of a complex number is defined, the Vieta's formulas for polynomial equations of degree 2, 3 and 4 are formalized. The solution of quadratic equations, the Cardan's solution of cubic equations and the Descartes-Euler solution of quartic equations in terms of their complex coefficients are also presented [5].
Intermolecular slip mechanism in tropocollagen nanofibrils
Authors: Gautieri Alfonso , Vesentini Simone , Redaelli Alberto , Buehler Markus J. 
Published: July 2009

AbstractWe report a detailed study of the shear interaction between two tropocollagen molecules, a major mechanism that contributes to the fibril mechanical behavior. Using steered molecular dynamics simulations in explicit solvent, we model the slip of two tropocollagen molecules at varying pulling rates. We find that the adhesion strength is highly sensitive to the pulling rate, and that it converges to a value of 10.12 pN Å– 1for vanishing loading rates. We find that intermolecular H-bonds play a key role in determining the resistance against slip. Our results provide quantitative details on this mechanism of load transmission inside collagen fibrils and fibers, which is crucial for the development of constitutive models of collagenous tissues at larger hierarchical levels. Such constitutive models of collagenous tissue mechanics have many applications, ranging from development of bio-inspired materials to studies in tissue engineering. By incorporating pathological collagen mutations, our studies could advance our knowledge of mechanisms underlying important collagen-related diseases like Osteogenesis Imperfecta or Ehlers – Danlos Syndrome.
Identification of model parameters from elastic/elasto-plastic spherical indentation
Authors: Niederkofler Thomas , Jäger Andreas , Lackner Roman 
Published: July 2009

Abstract
Spherical indentation is commonly used to study the elastic and visco-elastic response of materials at different length scales. However, depending on the strength properties of the investigated material and the geometric properties, such as sphere radius and penetration depth, plastic material response might occur, making parameter identification from load – penetration curves a difficult task. In this paper, the influence of the aforementioned parameters is investigated by means of numerical simulations, considering elasto-plastic material response. The numerical results obtained are presented in dimensionless format, finally providing (i) general rules for the specification of test parameters in the case of spherical indentation, on the one hand, and – in the case plastic deformation takes place – (ii) relations for the determination of plastic model parameters (such as the deviatoric strength) from the loading phase of the indentation test.
Penetration of a pyramid indenter into a multilayer coating
Authors: Kravchuk A. , Rymuza Z. , Jarzabek D. 
Published: July 2009

Abstract
A simple model of elastic – plastic penetration of a Berkovich pyramid into a multilayer coating has been developed. The model of a simply deformable body was used. It generalizes Winkler's foundation to the case of elastic – plastic deformation of each layer. The elastic – plastic deformation of a layer was modeled by Prandtl's bilinear approximation of a stress – strain curve. The homogenized coefficients of the elastic and plastic properties of the layer set and an analytical solution of the problem were found. The distribution of contact stress and depth of a pyramid indenter penetration were obtained for different angles.
Static Knee Alignment Measurements among Caucasians and African Americans: The Johnston County Osteoarthritis Project
Authors: NELSON AMANDA E. , BRAGA LARISSA , BRAGA-BAIAK ANDRESA , ATASHILI JULIUS , SCHWARTZ TODD A. , RENNER JORDAN B. , HELMICK CHARLES G. , JORDAN JOANNE M. 
Published: July 2009

Objective.To determine if knee alignment measures differ between African Americans and Caucasians without radiographic knee osteoarthritis (rOA).Methods.A single knee was randomly selected from 175 participants in the Johnston County Osteoarthritis Project without rOA in either knee. Anatomic axis, condylar, tibial plateau, and condylar plateau angles were measured by 1 radiologist; means were compared and adjusted for age and body mass index (BMI).Results.There were no significant differences in knee alignment measurements between Caucasians and African Americans among men or women.Conclusion.Observed differences in knee rOA occurrence between African Americans and Caucasians are not explained by differences in static knee alignment.
Serum CXCL16 Concentrations Correlate with the Extent of Skin Sclerosis in Patients with Systemic Sclerosis
Authors: YANABA KOICHI , MUROI EIJI , YOSHIZAKI AYUMI , HARA TOSHIHIDE , OGAWA FUMIHIDE , SHIMIZU KAZUHIRO , YOZAKI MARIKO , HASEGAWA MINORU , FUJIMOTO MANABU , TAKEHARA KAZUHIKO , SATO SHINICHI 
Published: July 2009

Objective.To determine serum concentrations of soluble CXCL16 and its clinical associations in patients with systemic sclerosis (SSc).Methods.Serum CXCL16 levels from 89 patients with SSc were examined by ELISA. In a retrospective longitudinal study, 68 sera from 28 patients with SSc were analyzed (followup 1.3 to 7.3 yrs).Results.Serum CXCL16 levels were elevated in patients with SSc compared with healthy controls (n = 42). Patients with diffuse cutaneous SSc (n = 52) had higher levels of CXCL16 than those with limited cutaneous SSc (n = 37). Serum CXCL16 levels correlated positively with the extent of skin sclerosis. In the longitudinal study, CXCL16 levels generally decreased on a parallel with the improvement in skin sclerosis.Conclusion.CXCL16 levels were increased in patients with SSc, and correlated with the extent of skin sclerosis, suggesting that CXCL16 may have a role in the development of skin fibrosis in SSc. Blockade of CXCL16 interaction might be a potential therapeutic target in patients with SSc.
Improvement in biomass characteristics and degradation efficiency in modified UASB reactor treating municipal sewage: a comparative study with UASB reactor
Authors: Das Suprotim , Chaudhari Sanjeev 
Published: July 2009

AbstractLow strength wastewaters (LSWs) are difficult to degrade efficiently in the upflow anaerobic sludge blanket (UASB) reactor. The possible reasons for poor treatment of LSWs in UASB are: (i) low mixing due to low biogas production (ii) frequent biomass washout at higher hydraulic loading rate due to low settleability of biomass. In the present study, lab scale UASB reactor and modified upflow anaerobic sludge blanket (MUASB) reactor were operated with municipal sewage containing chemical oxygen demand (COD) in range of 180–210 mg L−1 as LSW at three different hydraulic retention times (HRTs) of 8, 6, and 4 h. The changes in the biomass characteristics as well as degradation efficiency were compared with respect to time. During this operation, samples of biomass were taken from both reactors to measure total suspended solids (TSS), settling velocity, granular size and specific methanogenic activity (SMA). The overall COD removal in MUASB reactor was higher compared to UASB (84 and 67% respectively). After 150 days of operation, the settling velocity and SMA of MUASB biomass increased, but no significant change in settling velocity and SMA of UASB biomass was observed. The study shows that MUASB could be preferred over UASB for the treatment of municipal sewage as LSW. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd.
Catalytic wet air oxidation of high‐strength organic coking wastewater
Authors: Han Lihua , Zhu Jing , Kang Ju , Liang Yinghua , Sun Yang 
Published: July 2009

AbstractCatalytic wet air oxidation (CWAO) treatment of the high‐strength organic coking wastewater over CeCu and CeMn catalysts were studied. The main factors affecting the activities of the catalysts were investigated. Experimental results showed that in the absence of rare‐earth metal catalysts, CWAO process was also effective for high‐strength organic coking wastewater treatment. The catalyst, prepared with the active component CuCe (2:1) and carried by γ‐Al2O3/TiO2 calcined at 600 °C, has a higher activity. Up to 95.2% of the initial CODCr was removed at the reaction temperature of 180 °C and oxygen partial pressure of 1.2 MPa. The effect of the catalyst is equivalent to homogeneous catalysis improved by 60% over non‐catalytic treatment. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd.
Development and application of topographic descriptors for conditional analysis of rainfall
Authors: Ferranti Emma Jayne Sakamoto , Whyatt James Duncan , Timmis Roger James 
Published: July 2009

AbstractUpland rainfall is changing but regional climate models (RCMs) are poor at simulating observed precipitation in such areas of complex topography. This paper presents a method of examining observed rainfall patterns and processes under different conditions of synoptic meteorology and local topography. Objective topographic descriptors are defined and used to distinguish the modification of rainfall by local topography from that due to different synoptic conditions and climate change. A case study examining winter rainfall in Cumbria is presented. The conditional analysis method can be used to test RCM outputs so that model parameterisation can be improved. Copyright © 2009 Royal Meteorological Society
Synthesis and Electrochemical Performance of Ti4+ Doped LiV3O8
Authors: SUN Junli , JIAO Lifang , LIU Li , WEI Xin , YANG Lin , LIU Sichen , YUAN Huatang , WANG Yongmei 
Published: July 2009

AbstractLayered LiTiyV3−0.8yO8 cathode materials with y=0, 0.04, 0.06, 0.08 were prepared by a sol‐gel process following a calcination at 350°C in air for 16 h, and show differences in morphological properties (shape, particle size and specific surface area) and electrochemical properties (first charge profile, reversible capacity and rate capability). The LiTiyV3−0.8yO8 powders were characterized by means of X‐ray diffraction (XRD), charge/discharge cycling, cyclic voltammetry (CV), and scanning electron microscopy (SEM). LiTiyV3−0.8yO8 was crystallized to a well layered structure. Its initial specific discharge capacity was higher than that of pristine material. When y=0.04, the sample showed the highest initial discharge capacity of 348.9 mAh·g−1 at a current density of 60 mA·g−1 in the voltage range 1.8–4.0 V, and also higher discharge capacity and better cycle ability.
Fullerene[51] with Quasi‐planar Tetracoordinate Carbons and Its Derivatives
Authors: ZHANG Congjie , JIA Wenhong , CAO Zexing 
Published: July 2009

AbstractFullerene[51] containing quasi‐planar tetracoordinate carbons and its eight modificational compounds with quasi‐planar tetracoordinate carbons have been constructed. Using B3LYP method, their structures, stabilities, and bonding properties have been investigated, indicating that the nine novel structures are stable and have big vertical detachment energies and relatively small vertical electron affinities. The structures of the nine compounds contain five‐ and six‐membered rings, as well as bigger ten‐membered rings.
Silver Nanowire Film: Green Synthesis and Its Surface Enhanced Raman Scattering
Authors: TAO Xiucheng , LU Lei , SHAO Mingwang , HUANG Xiaojia 
Published: July 2009

AbstractOne‐step preparation of silver nanowires on the silicon wafer has been performed successfully employing silver nitrate as silver source. The procedure was operated at room temperature employing an environmentally benign compound of ethylene glycol as reductive agent, which is a completely green route. The as‐prepared products were characterized with X‐ray diffraction, scanning electron microscopy and energy dispersive X‐ray spectrum, which reveals uniform silver nanowires with average diameter of 20 nm. These silver nanowires were used to detect Rhodamine 6G via surface‐enhanced Raman scattering. The characteristic peaks appeared when the concentration of Rhodamine 6G was 10 nmol·L−1.
Large‐scale Hydrothermal Synthesis and Characterization of Size‐controlled Lanthanum Hydroxide Nanorods
Authors: YI Ran , ZHANG Ning , SHI Rongrong , LI Yongbo , QIU Guanzhou , LIU Xiaohe 
Published: July 2009

AbstractUniform lanthanum hydroxide nanorods were successfully synthesized in large quantities through a facile hydrothermal synthetic method, in which soluble lanthanum nitrate was used to supply the lanthanum source and triethylamine (TEA) was used as both alkaline agent and complexing agent. The influences of triethylamine amount, surfactant, reaction temperature and time on the size and shape of lanthanum hydroxide nanorods were investigated in detail. Trivalent rare earth ion doped lanthanum hydroxide nanorods were also obtained in this paper. The phase structures and morphologies of the as‐prepared products were investigated in detail by X‐ray diffraction (XRD), transmission electron microscopy (TEM), selected area electron diffraction (SAED) and high‐resolution transmission electron microscopy (HRTEM). The probable formation mechanism was proposed based on the experimental results.
Heck Reactions Catalyzed by Palladium Complex Supported on 4‐Aminopyridine Resin
Authors: WU Xiangmei , PEI Wen 
Published: July 2009

Abstract4‐Aminopyridine resin‐immobilized palladium catalyst was prepared by a simple procedure, which exhibited excellent activity at low loading levels for the phosphine‐free Heck vinylation of activated and non‐activated aryl or heteroaryl substrates with olefins in air. This method has the advantage of environmental benignity, generality, simplicity and potential for recycling of the resin catalyst.
A New Strategy for the Synthesis of 3‐Acyl‐coumarin Using Mesoporous Molecular Sieve MCM‐41 as a Novel and Efficient Catalyst
Authors: HERAVI Majid M. , POORMOHAMMAD Nargess , BEHESHTIHA Yahia Sh. , BAGHERNEJAD Bita , MALAKOOTI Reihaneh 
Published: July 2009

Abstract3‐Acyl‐coumarins were obtained in high yields from ortho‐hydroxybenzaldehydes and ethyl acetoacetate or ethyl benzoylacetate in acetonitrile in the presence of a catalytic amount of mesoporous molecular sieve MCM‐41. 3‐Acyl‐coumarins were obtained in high yields from ortho‐hydroxybenzaldehydes and ethyl acetoacetate or ethyl benzoylacetate in acetonitrile in the presence of a catalytic amount of mesoporous molecular sieve MCM‐41.
Cyclocondensation Reations of 3‐Amino‐1,2,4‐triazole with 3‐(Benzylidene)‐6‐fluoro‐thiochroman‐4‐ones to Tetracyclically Fused Dihydropyrimidines and Pyrimidines
Authors: MA Zhengyue , YAN Guoying , ZHU Shiguo , YANG Gengliang , LUO Duqiang 
Published: July 2009

AbstractThe effects of reaction temperature, solvents, reaction time and 7‐aryl on the cyclocondensation reactions of 3‐amino‐1,2,4‐triazole with 3‐(benzylidene)‐6‐fluorothiochroman‐4‐ones were studied. The experimental results show that except tetracyclic fused dihydropyrimidines and pyrimidines were produced simultaneously in the cyclocondensation reactions, the dihydropyrimidines could be directly converted into pyrimidines without any dehydrogenizing reagent under high temperature. The structures of the new synthesized compounds were confirmed by 1H NMR, MS spectra, elemental analysis, and X‐ray single crystallography. The cyclocondensation mechanism for producing the tetracyclically fused dihydropyrimidines and pyrimidines was discussed.
Preparation and Characterization of Olaquindox Polyclonal Antibody
Authors: CHE Huilian , SHI Baoxia , CHEN Jinlan , ZHU Xuejia , HE Jiguo 
Published: July 2009

Abstract2‐[N‐(2‐Hydroxyethyl)‐carbamoyl]‐3‐methyl‐oxoquinoxaline‐1,4‐oxides (OLA) was first mono‐esterificated by succinic acid anhydride, and was then turned into a derivative with carboxyl. The synthetic product was purified by recrystallization with a yield of 52.47%. Its chemical structure was determined by NMR, IR and MS spectra. The determined structure was used to synthese OLA hapten, which had the molecular structural characteristics of OLA. The OLA hapten and bovine serum albumin (BSA) were conjugated using the activated ester method, while the hapten and ovalbumin (OVA) were coupled by the mixed anhydride method. The UV scanning and infrared spectrum results showed that the hapten and the carrier protein were successfully coupled to BSA and OVA, with the combined ratios of 3.8:1 and 5:1, respectively. OLA‐BSA was used as the immunogen to immunize four New Zealand white rabbits, and the high titer anti‐serum produced relatively. The titers were 1:6400, 1:1600, 1:12800 and 1:6400, respectively, determined by indirect ELISA OLA‐OVA as the coating antigen. The intermediate inhibition concentration (IC50) of OLA in the indirect ELISA test was 743.3 ng/mL. The lowest detection limit (IC20) was 5.71 ng/mL. High‐purity OLA polyclonal antibody has been obtained by saturated ammonium sulfate and ion‐exchange chromatography.
Two‐dimensional echocardiographic discrimination of normal from abnormal great artery relationships
Authors: George L. , Waldman J. D. , Mathewson J. W. , Kirkpatrick S. E. , Pappelbaum S. J. , Turner S. W. 
Published: July 2009

AbstractA prospective study was performed to determine the diagnostic accuracy of precordial two‐dimensional echocardiographic techniques in discriminating normal from abnormal great artery relationships. We studied 503 children using standard parasternal short‐axis view and a modified technique called rotating high long‐axis view (RHLAV). In RHLAV, there is rapid superimposition of the proximal courses of the two great arteries seen by rotation of the ultrasonic beam. Discrimination was based on the crossing great artery relationship seen with normally related great arteries (NRGA) and the parallel courses found in both transposition and malposition of the great arteries (TGA/MGA). Using the RHLAV, the great artery interrelationship was accurately determined in all 503 patients. Precordial two‐dimensional echocardiography can accurately discriminate great artery relationships and is a useful addition to other two‐dimensional echocardiographic techniques.
Can the mode of death be predicted in patients with angiographically documented coronary artery disease?
Authors: Puddu P. E. , Bourassa M. G. , Lespérance J. , Hélias J. , Danchin N. , Goulet C. 
Published: July 2009

AbstractTo determine whether sudden versus non‐sudden cardiac death could be predicted in high risk patients, 1157 medical patients were followed for an average of 46 months after a diagnostic coronary angiogram and 18 clinical, hemodynamic, and angiographic variables known to be associated with a high risk of mortality were analyzed. The total group of 141 deaths was classified into 3 subgroups: (1) 82 sudden deaths (<1 hour after onset of symptoms); (2) 46 deaths due to acute myocardial infarction with or without heart failure, and (3) 13 deaths unrelated to cardiac symptoms. In a subset of 64 patients, the duration of electrical systole (QTC) was calculated before angiography and before death. A comparison was made of QTCmeasurements at entry with QTCvalues of subjects with normal coronary arteries and normal left ventricular function. Deaths from cardiac causes could often be predicted from older age, male sex, history of myocardial infarction, unstable angina, congestive heart failure, abnormal cardiothoracic ratio, multivessel disease, abnormal left ventricular contraction, and abnormal ejection fraction. However, these variables did not discriminate between sudden and nonsudden cardiac deaths and both modes of death were characterized by depressed left ventricular function and multivessel coronary disease. During follow‐up the incidence of acute myocardial infarction was not different in patients with cardiac and noncardiac deaths and in long‐term survivors. However, patients dying from cardiac causes had a higher incidence of heart failure. Patients dying suddenly did not present new infarctions during follow‐up whereas patients dying from acute myocardial infarction had a 13% incidence of prior infarction and a higher incidence of heart failure. In addition, QTCat entry was longer in nonsurvivors than in normal subjects (p<0.0001) and patients experiencing sudden death exhibited the highest incidence of QTCprolongation (≥440 ms) during follow‐up (p<0.05). We conclude that: (1) although the severity of coronary disease and left ventricular dysfunction are closely related to cardiac mortality, they do not discriminate between sudden and nonsudden cardiac deaths; (2) patients experiencing sudden death are characterized by a low incidence of new myocardial infarction or congestive heart failure and prolongation of the QTCinterval during follow‐up.
Serial ambulatory monitoring in patients with unstable angina pectoris
Authors: Mooss A. N. , Aronow W. S. , Sketch M. , Mohiuddin S. M. , Ryschon K. 
Published: July 2009

AbstractWe performed a prospective study by dual‐channel ambulatory monitoring performed for 24 to 72 hours immediately after hospitalization for unstable angina. The incidence of ST‐segment depression or elevation or ventricular tachycardia or complex premature ventricular complexes (PVCs) in 42 consecutive patients with unstable angina due to coronary artery disease (39 by coronary arteriography) was investigated. During ambulatory monitoring, 28 of 42 patients (67%) exhibited ST‐segment depression or elevation, 13 of 42 patients (31%) had ventricular tachycardia or complex PVCs, and 31 of 42 patients (74%) had either ST‐segment depression or elevation, ventricular tachycardia, or complex PVCs. Ventricular tachycardia or complex PVCs occurred in 10 of 20 patients (50%) with abnormal left ventricular function and in 3 of 22 patients (14%) with normal left ventricular function (p<0.025). We found that 72 hours of ambulatory monitoring was not more useful than 48 hours in detecting the incidence of ST‐segment depression or elevation, ventricular tachycardia, or complex PVCs. Ambultory monitoring did not help in clinically differentiating patients with left main or 3‐vessel disease from 1‐vessel or 2‐vessel disease. In addition, ambulatory monitoring did not help in predicting which patients with unstable angina would require coronary artery surgery.
Congestive heart failure in valvular heart disease in pregnancies with and without valvular prostheses and anticoagulant therapy
Authors: Sheikhzadeh A. , Ghabusi P. , Hakim S H. , Wendler G. , Sarram M. , Tarbiat S. 
Published: July 2009

AbstractThe course and complications of pregnancies in 46 patients with valvular disease and congestive heart failure with or without valve prostheses are described. In group I consisting of 33 women without valve replacement and without anticoagulant therapy one thromboembolic event was seen, emergency closed or open heart surgery was necessary five times. One stillbirth happened after open heart surgery. In group II, of 13 patients with prosthetic valve replacement and anticoagulation therapy there was no thromboembolism, but 2 spontaneous abortions and 2 premature stillbirths; 2 fetuses died after delivery, 3 had congenital abnormalities. Pregnancies in patients with valvular disease and congestive heart failure can be sustained relatively safely for the mother, even if emergency heart surgery becomes necessary. Heart surgery and anticoagulation treatment carry a higher risk for the fetus. Uterine blood loss is not increased, if coumadine treatment is switched to heparin administration shortly before delivery.