bluuebunny/crossref_metadata_2025_split huggingface dataset:
Internal wave drag in stratified flow over mountains on a beta plane
Authors: Teixeira M. A. C. , Grisogono Branko 
Published: March 2008

AbstractThe impact of the variation of the Coriolis parameter f on the drag exerted by internal Rossby‐gravity waves on elliptical mountains is evaluated using linear theory, assuming constant wind and static stability and a beta‐plane approximation. Previous calculations of inertia‐gravity wave drag are thus extended in an attempt to establish a connection with existing studies on planetary wave drag, developed primarily for fluids topped by a rigid lid. It is found that the internal wave drag for zonal westerly flow strongly increases relative to that given by the calculation where f is assumed to be a constant, particularly at high latitudes and for mountains aligned meridionally. Drag increases with mountain width for sufficiently wide mountains, reaching values much larger than those valid in the non‐rotating limit. This occurs because the drag receives contributions from a low wavenumber range, controlled by the beta effect, which accounts for the drag amplification found here. This drag amplification is shown to be considerable for idealized analogues of real mountain ranges, such as the Himalayas and the Rocky mountains, and comparable to the barotropic Rossby wave drag addressed in previous studies. Copyright © 2008 Royal Meteorological Society
Comparison between a switching controller and two LTI controllers for a class of LTI plants
Authors: Santarelli Keith R. , Dahleh Munther A. 
Published: March 2008

AbstractWe consider the design of three different control architectures for a step response tracking problem within a class of linear time‐invariant (LTI) plants. Our goal is to motivate the use of a particular switching architecture that has been the subject of our prior work. We present the design of the particular switching architecture that we use and characterize its step response performance (measured in terms of the percentage overshoot and 1% settling time of the step response). We then compare the response of the switching controller with two other forms of LTI control in a servo configuration, one in which the order of the controller is constrained to be first order (which matches the order of the dynamics of the switching controller) and one in which the order of the controller is unconstrained. We will show that the switching architecture can outperform first‐order LTI control, first in the context of a particular example. We shall then provide a weak generalization to extend this result to a more general class of plants. We shall also show that, while the LTI control of unconstrained order can outperform the switching architecture, the performance improvement is bounded (in a sense to be defined). Moreover, one method of designing close‐to‐optimal controllers will be discussed, which yields controllers of very high order. Copyright © 2008 John Wiley & Sons, Ltd.
An application of multivariate ranks to assess effects from combining factors: Metal exposures and semen analysis outcomes
Authors: Ramamoorthi R. V. , Rossano M. G. , Paneth N. , Gardiner J. C. , Diamond M. P. , Puscheck E. , Daly D. C. , Potter R. C. , Wirth J. J. 
Published: March 2008

AbstractIn studies of environmental effects on human health outcomes, it is often difficult to assess the effects of a group of exposure variables when the individual exposures do not appear to have statistically significant effects. To address this situation, we propose a method of U‐scores applied to subsets of multivariate data. We illustrate the usefulness of this approach by applying it to data collected as part of a study on the effects of metal exposure on human semen parameters. In this analysis, profiles (pairs) of metals containing copper and/or manganese were negatively correlated with total motile sperm and profiles containing copper were negatively correlated with sperm morphology; profiles containing selenium and chromium were positively correlated with total motile sperm. Copyright © 2008 John Wiley & Sons, Ltd.
An overview on the ancient goldsmith's skill and the circulation of gold in the past: the role of x‐ray based techniques
Authors: Guerra Maria Filomena 
Published: March 2008

AbstractFrom the study of coins and casted simple objects to intricate jewellery comprising many diverse parts joined together, analytical queries on ancient goldwork concern the description of the manufacturing techniques, the identification of the authenticity and the localisation of the exploited sources of gold. Through the examination of the objects by x‐ray radiography and the non‐destructive elemental analysis of the gold alloys – by XRF, SEM‐EDX, PIXE and SR‐XRF, x‐ray based techniques have always played an important role in the study of cultural heritage and, in particular, of goldwork.The aim of this article is to give a short overview of the use of the most established scientific‐based techniques in the study of goldwork, with special outlining on the limitations, advantages and applications of x‐ray based techniques. Two applications illustrate both the potential of examination techniques to identify the authenticity of gold jewellery and the importance of combining examination techniques and elemental analysis to describe the fabrication stages of goldwork. At last, a third example shows the significant socio‐economical assumptions developed by determining the characteristic trace elements of gold when coinages are considered. Copyright © 2008 John Wiley & Sons, Ltd.
Gilding and silvering surface decoration techniques, and copper provenance studies of the tomb of D. Afonso of Portugal (15th century)
Authors: Borges Rui , Tissot Isabel , Seruya Ana Isabel , C. Silva Rui J. , Fragoso Sara , Maduro Belmira , Pais Alexandre 
Published: March 2008

AbstractThe tomb of D. Afonso of Portugal (1390‐1400), king D. João I first born raises questions about the production of its different elements, which according to their typology were not all made simultaneously. The singularity of both the composition of the metal and the type of techniques ‐ fire gilding and amalgam silvering ‐ used in the decoration of some elements causes difficulties in the attribution of the tomb to a Flanders or to a Portuguese workshop.The aim of this work is to attribute to the tomb a possible production origin based on the study of the copper provenance. Special attention was given to decorative techniques because these could bring further information about the production of the elements. For these purposes PIXE and SEM‐EDS analysis were used.PIXE analysis revealed the importance given to the choice of an almost pure copper for the tomb pieces, since it has a direct consequence in the manufacture and decorative techniques. It also allowed concluding that the composition of the pieces correlates very well with the coins minted during D. Afonso V period, further studies being necessary to compare the results with objects from Flanders.Analysis by SEM/EDS characterized the gilded coating as being made of a layer of Au + Hg applied by fire amalgam. In the silvered coating, the existence of two separate layers characterises the silvering technique as having been executed by the application of an Ag + Hg amalgam, on top of a first layer of Au + Hg, also applied by amalgam. Copyright © 2008 John Wiley & Sons, Ltd.
Fundamental parameter approach to XRF spectroscopy measurements of arsenic in polyester resin skin phantoms
Authors: Gherase Mihai Raul , Fleming David E. B. 
Published: March 2008

AbstractA fundamental parameter (FP) approach that explicitly incorporates the energy‐broadening response of the detector was developed. The ratio between Kα fluorescence peak area and the sum of coherently and incoherently scattered peak areas was used as an indicator of trace element concentration. The peak ratio was theoretically calculated using the FP method. The energy‐broadening response curve of the Si(Li) detector was estimated by matching the theoretical and experimental values of this ratio. The method was implemented for the analysis of the K‐shell x‐ray fluorescence (K‐XRF) spectra of six polyester resin samples corresponding to six different arsenic concentrations. A 109Cd radioactive source provided the excitation radiation for spectra acquisition. The predicted detector energy resolution expressed as full width at half‐maximum (FWHM) for Fe Kα fluorescence peak (208 ± 5 eV at 6.4 keV) and As Kα fluorescence peak (222 ± 5 eV at 10.5 keV) were in agreement with the experimental measurements. Copyright © 2008 John Wiley & Sons, Ltd.
Synthesis and Characterization of the New Copper Tetraphosphonate Cu2[(HO3PCH2)4C6H2]·2H2O
Authors: Kaempfe Paulina , Stock Norbert 
Published: March 2008

AbstractFollowing the strategy of using polyfunctional phosphonic acids for the synthesis of three‐dimensional metal phosphonates, the ethyl ester of a tetraphosphonic acid, i. e. 1,2,4,5‐(Et2O3PCH2)4C6H2, was used in the hydrothermal synthesis of the new copper tetraphosphonate, Cu2[(HO3PCH2)4C6H2]·2H2O (1). The in situ hydrolysis of the ethyl ester leads to the acid (1,2,4,5‐(H2O3PCH2)4C6H2) which reacts with the Cu2+ ions to form the green coarse‐crystalline product. The title compound is the first fully characterized copper tetraphosphonate. Its structure was solved from single crystal data (1: triclinic, $\rm P{\bar 1}$, a = 4.9262(10), b = 8.1890(16), c = 11.800(2) Å, α = 71.17(3), β = 89.15(3), γ = 88.56(3)°, V = 450.39(16) Å3, Z = 2, R1 = 0.0284, wR2 = 0.0682). The structure is built up from edge‐sharing CuO5 polyhedra each containing a single H2O molecule. Thus, dimeric [Cu2O8] units are formed. In the second coordination sphere of each of the Cu2+ ions four HO3PCH2R units are observed. The [Cu2O8] polyhedra are connected to eight other [Cu2O8] polyhedra by these organic linkers and a three‐dimensional framework structure is formed. Thermogravimetric, magnetic, and temperature dependent powder XRD measurements and the Raman‐spectrum are also presented.
LixNayBa14LiN6: New Representatives of the Subnitride Family
Authors: Smetana Volodymyr , Babizhetskyy Volodymyr , Simon Arndt 
Published: March 2008

AbstractThree new metal‐rich phases, Li4Na11Ba14LiN6, Li5Na10Ba14LiN6 and Na14Ba14LiN6 have been prepared and their crystal structure determined. According to single crystal and powder X‐ray diffraction data, all compounds crystallize with cubic unit cells (Li4Na11Ba14LiN6: $F{\bar 4}{\rm 3}m$, a = 17.874(2) Å, Z = 4, V = 5710(1) Å3; Li5Na10Ba14LiN6: $F{\bar 4}{\rm 3}m$, a = 17.799(1) Å, Z = 4, V = 5638.7(6) Å3; Na14Ba14LiN6: $Fm{\bar 3}m$, a = 17.7955(5) Å, Z = 4, V = 5635.6(2) Å). The last mentioned compound crystallizes in the Na14Ba14CaN6 type, and both Li4Na11Ba14LiN6 and Li5Na10Ba14LiN6 have related structures. These compounds open a series of metal‐rich Ba nitrides, containing the new Ba14LiN6 cluster.
Heterobimetallic Complexes: Substitution Effects in the [Tetracarbonylrhodiumbis{μ‐(diphenylphosphino)}{μ‐(η:η2‐(4‐diphenylphosphino‐κP)‐2‐methyl‐oxobutyl)}molybdenum](Mo‐Rh) System
Authors: Coutinho Kevin J. , Dickson Ron S. , Koutsantonis George A. , Skelton Brian W. , White Allan H. 
Published: March 2008

AbstractSyntheses of the array of heterobimetallic complexes [(OC)3M(μ‐PPh2)2(μ‐O‐C(CHMe(CH2)2PPh2)RhL], M = Cr, Mo, W, L = tBuNC, are described, extending the previous study of the counterpart array for L = CO. A single crystal X‐ray structure determination is reported for the M = Mo adduct, enabling comparison with its previously reported L = CO counterpart, for which an improved redetermination is also reported. In the present complex the tBuNC ligand is found to be much more weakly bound (Rh‐C 2.026(5) Å) than the carbonyl group it displaces (Rh‐C 1.945(2) Å) with concomitant minor impact on the remainder of the rhodium ambience.
Dichalcogenide Cleavage and Carbonyl Insertion Reactions on a Dirhodium Bond
Authors: Devery Michael P. , Dickson Ron S. , Fallon Gary D. , Koutsantonis George A. , Skelton Brian W. , White Allan H. 
Published: March 2008

AbstractThe reaction of the binuclear rhodium complex [(η−C5H5)2Rh2(μ‐CO)(μ‐η1:η1‐C2(CF3)2)] with a series of dichalcogenides, R2E2 (E = S, Se, Te; R = Me, Et, i‐Pr, Ph, Fc; not all combinations) has provided mixtures of complexes, the majority of which have been characterized by standard spectroscopic techniques. These complexes arise as a consequence of carbonyl substitution followed by chalcogen‐chalcogen bond cleavage giving [(η−C5H5)2Rh2(μ‐ER)2(μ‐η1:η1‐C2(CF3)2)], possibly concomitant with CO insertion into a Rh‐C2(CF3)2 bond of the product in some cases, giving [(η−C5H5)2Rh2(CO)(μ‐ER)2(μ‐η1:η1‐C2(CF3)2C(O))] (E = Se, Te; R = Me, Et, i‐Pr, Ph, Fc; not all combinations). In the case of Te2R2 the dichalcogenide products have been structurally characterized for the carbonyl insertion product (for R = Et) and the simple cleavage case (for R = i‐Pr). In both, the putative m‐symmetry is broken by substituent dispositions and, in the R = Et adduct, torsion in the fluorocarbon skeleton.
[(C6F5)2IF2][BF4], the First Salt with the Electrophilic Cation [(C6F5)2IF2]+: Synthesis, Reactivity, and Structure
Authors: Frohn Hermann‐Josef , Wenda André , Flörke Ulrich 
Published: March 2008

AbstractThe substitution of hypervalently bonded fluorine atoms in C6F5IF4 was performed with C6F5BF2 and resulted in the new salt [(C6F5)2IF2][BF4]. The iodonium(V) salt was characterized by multi‐NMR and Raman spectroscopy and X‐ray crystal structure analysis. The fluorinating ability of the new electrophilic cation [(C6F5)2IF2]+ was exemplified in reactions with monovalent iodine compounds (C6F5I, p‐FC6H4I, and I2) and with electron‐poor tri(organyl)pnictanes ER3 (E = P, As, Sb, Bi; R = C6F5). In a heterogeneous reaction with CsF in MeCN the [(C6F5)2IF2]+ cation forms the dinuclear [{(C6F5)2IF2}2F]+ cation.
Mercuric Bis(N‐imino‐methyl‐formamidate), Hg(Imf)2
Authors: Nockemann Peter , Pantenburg Ingo , Meyer Gerd 
Published: March 2008

AbstractSingle crystals of mercuric bis(N‐imino‐methyl‐formamidate), Hg(Imf)2, were obtained from aqueous solutions of 1,2,4‐triazole and Hg(NO3)2·2H2O. The crystal structure [monoclinic, P21/c (no. 14), a = 499.6(2), b = 1051.2(4), c = 711.1(3) pm, β = 117.55(1)°, Z = 2, R1 for 890 reflections with I0>2σ(I0): 0.0369] contains linear centrosymmetric Hg(Imf)2 molecules with Hg–N distances of only 203.5(7) pm. Two plus two intra‐ and intermolecular nitrogen atoms add to an effective coordination number of 6.
Tetrakis(acetonitrile)‐dibromo‐nickel(II)‐di‐acetonitrile, [Ni(CH3CN)4Br2]·2CH3CN
Authors: Getsis Anna , Mudring Anja‐Verena 
Published: March 2008

Abstract[Tetrakis(acetonitrile)‐dibromo‐nickel(II)]‐di‐acetonitrile was obtained from a solution of nickel(II) dibromide in acetonitrile at 258 K. The crystal structure [monoclinic, P21/n (no.14), a = 1005.5(5), b = 831.3(5) , c = 1131.7(5) pm, β = 106.263(5)°, V = 908.1(8)·106 pm3, Z = 2, R1 for 1580 reflections with I0>2σ(I0): 0.0505] contains sixfold coordinated NiII atoms. Two trans coordinating bromide anions and four equatorial acetonitrile molecules form an elongated octahedron around the central NiII atom. [Ni(CH3CN)4Br2] octahedra are connected via hydrogen bonds to neighboring octahedra as well as to solvate acetonitrile molecules.
Indium(I) Tetraiodoaluminate, InAlI4
Authors: Timofte Tudor , Mudring Anja‐Verena 
Published: March 2008

AbstractIndium(I) tetraiodoaluminate, InAlI4, was obtained from the respective molar amounts of In, InI3 and AlI3 at 553 K. The crystal structure [monoclinic, P21/m (no. 11), a = 713.5(4), b = 1182.2(3), c = 1108.3(6) pm, β = 96.32(6)°, V = 1013.2(8)·106 pm3, Z = 4, R1 for 981 reflections with I0>2σ(I0): 0.0404] contains discrete indium(I) cations and tetraiodoaluminate anions. No evidence was found for a stereochemical activity of the In‐5s2 electron pair. InAlI4 (Person code mP24) represents a new structure type within the ABX4 structure family.
Surgery and Radiofrequency Ablation for Treatment of Liver Metastases from Midgut and Foregut Carcinoids and Endocrine Pancreatic Tumors
Authors: Eriksson John , Stålberg Peter , Nilsson Anders , Krause Johan , Lundberg Christina , Skogseid Britt , Granberg Dan , Eriksson Barbro , Åkerström Göran , Hellman Per 
Published: March 2008

AbstractBackgroundMany neuroendocrine tumors (NETs) have a tendency to metastasize to the liver. In case of limited number of metastases, liver surgery or radiofrequency ablation (RFA) may result in apparently total clearance of metastases. However, it is not clear whether such therapy will provide symptom reduction or increased survival.MethodsSeventy‐three patients with foregut (n = 6) or midgut carcinoids (n = 37) or endocrine pancreatic tumors (n = 28), and two patients with NETs without discernable origin were studied. Symptoms were evaluated using a Symptom Severity Score. Liver surgery was performed in 42 operations and RFA on 205 lesions.ResultsApparently total clearance of liver metastases was attained in 1 of 6 patients with foregut carcinoids, 15 of 37 with midgut carcinoids, and 13 of 28 with EPT. Symptom improvement was noted in 12 of 17 (70.6%) patients with carcinoid syndrome, and 75% also reduced their 5‐HIAA and P‐CgA by at least 50%. Patients with nonfunctioning EPT generally had no improvement of symptoms after surgical/RFA liver treatment, but eight patients had functioning EPT, and four of these reduced their biochemical markers by at least 50%. NETs with higher Ki67 index tended to recur more often. Complications occurred in 9 of 45 open surgery procedures, and in 8 of 203 RFA procedures.ConclusionsTreatment of liver metastases is successful in midgut carcinoid patients with limited liver metastases. Patients with foregut carcinoid and EPTs recur more often, possibly related to higher Ki67 index, and treatment of liver lesions less often reduces symptoms. Liver resections and RFA may be safely performed, and RFA is associated with few complications.
What is new in uremic toxicity?
Authors: Vanholder Raymond , Van Laecke Steven , Glorieux Griet 
Published: March 2008

AbstractUremic syndrome results from a malfunctioning of various organ systems due to the retention of compounds which, under normal conditions, would be excreted into the urine and/or metabolized by the kidneys. If these compounds are biologically active, they are called uremic toxins. One of the more important toxic effects of such compounds is cardio-vascular damage. A convenient classification based on the physico-chemical characteristics affecting the removal of such compounds by dialysis is: (1) small water-soluble compounds; (2) protein-bound compounds; (3) the larger “middle molecules”. Recent developments include the identification of several newly detected compounds linked to toxicity or the identification of as yet unidentified toxic effects of known compounds: the dinucleotide polyphosphates, structural variants of angiotensin II, interleukin-18,p-cresylsulfate and the guanidines. Toxic effects seem to be typically exerted by molecules which are “difficult to remove by dialysis”. Therefore, dialysis strategies have been adapted by applying membranes with larger pore size (high-flux membranes) and/or convection (on-line hemodiafiltration). The results of recent studies suggest that these strategies have better outcomes, thereby clinically corroborating the importance attributed in bench studies to these “difficult to remove” molecules.
Surface Melting in Alkane Emulsion Droplets as Affected by Surfactant Type
Authors: Gülseren İbrahim , Coupland John N. 
Published: March 2008

AbstractThe influence of surfactant type (Tween 20, Tween 40, Tween 60, Tween 80, Brij 58, Triton X‐100, SDS, STS) on the crystallization and melting characteristics of emulsified (mean droplet diameter 0.52 μm) n‐octadecane and n‐eicosane were studied using microcalorimetry. The melting point (~37 °C) of the eicosane droplets was higher than the crystallization point (~24 °C) and was not affected by the surfactant selected. There was a similar separation between the crystallization (~14 °C) and melting (~28 °C) point of the emulsified octadecane however the details of the transitions was affected by the surfactant selected. For Tween 40 and Brij 58‐stabilized droplets there was a split peak on crystallization which we attribute to a surface heterogeneous nucleation mechanism. Only these surfactant‐alkane combinations had a split peak on melting. The size of the lower temperature fraction decreased with droplet size suggesting another surface effect. However, the size of the surface layer was calculated to be many times the length of the surfactant tail suggesting the crystal structure was modified by the nucleation mechanism.
Surgical Patient Education Related to Smoking
Authors: Lauerman Cecelia J. 
Published: March 2008

ABSTRACTESTIMATES INDICATE THAT ONE MILLION patients who smoke present annually in the United States for some form of surgical intervention. Smoking is a known cause of respiratory complications, hemodynamic fluctuations, and delayed wound healing.A LITERATURE SEARCH REVEALED a small number of available studies that address the education provided to surgical patients who smoke.INFORMATION ABOUT THE EFFECTS of smoking on surgical outcomes is not routinely provided to smokers. Determining the best methods by which to provide smoking cessation counseling will help increase patients' chances for a positive surgical outcome.
A randomized comparative study of prophylactic oxytocin versus ergometrine in the third stage of labor
Authors: Orji Ernest , Agwu Felix , Loto Olabisi , Olaleye Oladapo 
Published: March 2008

AbstractObjectiveTo compare the effect of prophylactic use of oxytocin and ergometrine in management of the third stage of labor.MethodsA prospective randomized study of 600 women assigned to receive either oxytocin or ergometrine in the third stage of labor. Outcome measures were the predelivery and 48‐hour postdelivery hematocrit, duration of the third stage, specific side effects, and incidence of postpartum hemorrhage. Statistical analyses were done using thettest for continuous variables andχ2test for categorical variables. The level of significance was set atP< 0.05.ResultsThere were no significant differences between the 2 groups in maternal age, gestational age, duration of third stage, birth weights, risk for retained placenta, manual removal of placenta, or need for additional oxytocics. Patients in the ergometrine group were at significant risk for nausea, vomiting, headaches, and elevated blood pressure (P= 0.0001).ConclusionOxytocin is as effective as ergometrine at reducing the incidence of postpartum hemorrhage, but without the undesirable side effects of nausea, vomiting, and elevated blood pressure associated with ergometrine.
Peripartum hysterectomy in Taiwan
Authors: Jou Hei‐Jen , Hung Hsin‐Wen , Ling Pei‐Ying , Chen Shih‐Ming , Wu Shiao‐Chi 
Published: March 2008

AbstractObjectiveTo investigate the incidence and associated risk factors for peripartum hysterectomy in singleton pregnancies.MethodsA retrospective cohort study of all women with singleton pregnancies admitted for delivery in 2002 taken from the National Healthcare Insurance database. Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were calculated for maternal and hospital characteristics using logistic regression.ResultsThere were 287 peripartum hysterectomies in 214 237 singleton pregnancies (0.13%). Cesarean delivery, vaginal birth after cesarean (VBAC), and repeat cesarean delivery had higher hysterectomy rates than vaginal delivery, with adjusted ORs of 12.13 (95% CI 8.30–17.74), 5.12 (95% CI 1.19–21.92), and 3.84 (95% CI 2.52–5.86), respectively. Pregnancies complicated with placenta previa, gestational diabetes mellitus (GDM), and premature labor were associated with significantly increased risks for peripartum hysterectomy (P< 0.05).ConclusionRisk factors for peripartum hysterectomy included cesarean delivery, VBAC, repeat cesarean, placenta previa, GDM, and premature labor. VBAC and repeat cesarean had a similar risk.