bluuebunny/crossref_metadata_2025 huggingface dataset:
Gd3+ and Eu2+ local environment in Ca1–xEuxB6 (0.0001 ≤ x ≤ 0.30) and Ca1–xGdxB6 (0.0001 ≤ x ≤ 0.01)
Authors: Urbano R. R. , Pagliuso P. G. , Rettori C. , Schlottmann P. , Fisk Z. , Chapler B. , Oseroff S. B.
Published: May 2006

Local environment of Gd3+ and Eu2+ 4f7 ions, S = 7/2, in Ca1–x Eux B6 (0.0001 ≤ x ≤ 0.30) and Cax Gdx B6 (0.0001 ≤ x ≤ 0.01) is investigated by means of electron spin resonance (ESR). For x ≤ 0.001 the spectra show resolved fine structures due to the cubic crystal electric field and, in the case of Eu, the hyperfine structure due to the nuclear hyperfine field is also observed. The resonances have Lorentzian line shape, indicating insulating host for the Gd3+ and Eu2+ ions. As x increases, the ESR lines broaden due to local distortions caused by the Ca/Gd,Eu ions substitution. For Gd (x ≈ 0.001) and Eu (x ≈ 0.02), the spectra present superposition of Lorentzian and Dysonian resonances, suggesting a coexistence of insulating and metallic hosts for the Gd3+ and Eu2+ ions. The Gd3+ and Eu2+ fine structures are still observable up to x ≈ 0.003 for Gd and x ≈ 0.15 for Eu. For larger values of x the fine and hyperfine structures are no longer observed, the line width increases, and the line shape becomes pure Dysonian anticipating the metallic and semimetallic character of GdB6 and EuB6, respectively. These results clearly show that in the low concentration regime the Ca1–x Rx B6 (R = Gd, Eu) systems are intrinsically inhomogeneous. No evidence of weak ferromagnetism (WF) was found in the ESR spectra of either metallic or insulating phases of these compounds, suggesting that, if WF is present in these materials, the Gd3+ and Eu2+ 4f7‐electrons are shielded from the WF field. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
AlGaN multiple quantum well based deep UV LEDs and their applications
Authors: Asif Khan M.
Published: May 2006

In this paper we will describe the approaches that we have used to grow AlGaN‐based multiple quantum well deep UV LED structures and to overcome issues of doping efficiency, cracking, and slow growth rates both for the n‐ and the p‐type layers of the device structures. This has led to the fabrication of devices with emission from 250–340 nm and cw‐milliwatt powers at pump currents of only 20 mA (V f ≤ 6 V). Record wall plug efficiencies as high as 1.5% are now achievable for devices with emission at 280 nm. Thermal management and a proper device design are not only a key to achieving these record performance numbers but are also crucial to device reliability. We will also discuss some of our initial research to clarify the factors influencing the lifetime of the deep UV LEDs. In addition to our own work, we will review the results from the excellent research carried out at several other laboratories worldwide. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
1‐Oxa‐nido‐dodecaborate [OB11H12]− from the Controlled Oxidation of the closo‐Borates [B11H11]2− and [B12H12]2−
Authors: Volkov Oleg , Paetzold Peter , Hu Chunhua
Published: May 2006

The closo‐dodecaborate [B12H12]2− is degraded at room temperature by oxygen in an acidic aqueous solution in the course of several weeks to give B(OH)3. The degradation is induced by Ag2+ ions, generated from Ag+ by the action of H2S2O8. Oxa‐nido‐dodecaborate(1−) is an intermediate anion, that can be separated from the reaction mixture as [NBzlEt3][OB11H12] after five days in a yield of 18 %. The action of FeCl3 on the closo‐undecaborate [B11H11]2− in an aqueous solution gives either [B22H22]2− (by fusion) or nido‐B11H13(OH)− (by protonation and hydration), depending on the concentration of FeCl3. In acetonitrile, however, [B11H11]2− is transformed into [OB11H12]− by Fe3+ and oxygen. The radical anions [B12H12]˙− and [B11H11]˙− are assumed to be the primary products of the oxidation with the one‐electron oxidants Ag2+ and Fe3+, respectively. These radical anions are subsequently transformed into [OB11H12]− by oxygen. The crystal structure analysis shows that the structure of [OB11H12]− is derived from the hypothetical closo‐oxaborane OB12H12 by removal of the B3 vertex, leaving a non‐planar pentagonal aperture with a three‐coordinate O vertex, as predicted by NMR spectra and theory.
Structure and Magnetic Properties of Ce3Ge0.66In4.34 and Ce11Ge4.74In5.26
Authors: Zaremba Vasyl' I. , Kaczorowski Dariusz , Nychyporuk Galyna P. , Rodewald Ute Ch. , Heying Birgit , Pöttgen Rainer
Published: May 2006

New indides Ce3Ge0.66In4.34 and Ce11Ge4.74In5.26 were synthesized from the elements by arc‐melting and subsequent annealing at 870 K. Single crystals were grown through special annealing procedures in sealed tantalum tubes in a high‐frequency furnace. Both compounds were investigated on the basis of X‐ray powder and single crystal data: I4/mcm, La3GeIn4 type, a = 848.8(1), c = 1192.0(2) pm, Z = 4, wR2 = 0.0453, 499 F2 values, 17 variables for Ce3Ge0.66In4.34 and I4/mmm, Sm11Ge4In6 type (ordered version of the Ho11Ge10 type), a = 1199.3(2), c = 1662.0(3) pm, wR2 = 0.0507, 1217 F2 values, 41 variables for Ce11Ge4.74In5.26. The Ce3Ge0.66In4.34 structure shows a mixed Ge/In occupancy on the 4c Wyckoff position. This site is octahedrally coordinated by cerium atoms. These octahedra share all edges, leading to a three‐dimensional network. The latter is penetrated by a two‐dimensional indium substructure which consists of flattened tetrahedra at In–In distances of 291 and 300 pm. The Ce11Ge4.74In5.26 structure contains three crystallographically independent germanium sites. The latter are coordinated by eight or nine cerium neighbors. These CN8 and CN9 polyhedra are condensed to a complex network which is penetrated by a three‐dimensional indium network with In–In distances of 301–314 pm. The 16m site shows a mixed In/Ge occupancy. Chemical bonding in both compounds is dominated by the p elements. Both ternaries studied exhibit localized magnetism due to the presence of Ce3+ ions. The compound Ce3GeIn4 remains paramagnetic down to 1.72 K, whereas Ce11Ge4In6 orders ferromagnetically at TC = 7.5 K.
Lanthanides as d Metals
Authors: Simon Arndt , Mattausch Hansjürgen , Ryazanov Mikhail , Kremer Reinhard K.
Published: May 2006

Reduction of lanthanide trihalides with alkali metals along the route used by Klemm and Bommer leads to pure lanthanide metals. In closed Ta capsules at elevated temperatures, however, metal‐rich halides form which use the excess of Ln centered electrons for metal‐metal bonding. An overview of the extended d metal chemistry of lanthanides in binary, ternary and quaternary halides is presented. Consequences of the mutual interaction of d and f electrons are illustrated for selected magnetic and electrical properties.
A Mononuclear η2‐Bonded Phosphaalkyne Nickel(0) Complex
Authors: Schaub Thomas , Radius Udo
Published: May 2006

The synthesis and characterization of the new complex [Ni(ImiPr)2(η2‐P≡C‐tBu)] (1) is reported. Compound 1 represents the first structurally characterized example of a mononuclear nickel(0) complex with a side on coordinated phophaalkyne ligand.
High‐valent Molybdenum Imido Complexes with Tethered Olefins
Authors: Siewert Inke , Limberg Christian , Ziemer Burkhard
Published: May 2006

Against the background of the (propene)Mo(=O)(=NH) and (allyl)Mo(=O)(=NH) surface species suggested as intermediates of the SOHIO process the potential of H2N–C6H4–CH2– CH=CH–CH3, (I), for the introduction of chelating imido/olefin or imido/allyl ligands at highvalent Mo centres was tested. Reaction of I with Na2[MoO4] and trimethylchlorosilane yielded [Cl2Mo(=N–C6H4–CH2–CH=CH–CH3)2(dme)] (1), containing pendant olefinic arms. All attempts to introduce the olefin into the coordination sphere of the Mo centre failed. The same observation was made with [Cl2Mo(=O)(=N–C6H4–CH2–CH=CH–CH3)(dme)] (2), synthesised via a commutation reaction from 1 and[(dme)Cl2Mo(=O)2]. Reaction of three equivalents of I with [CpMoCl4′] yields [CpCl2Mo(=N–C6H4–CH2–CH=CH–CH3)], (3), again with a pendant olefin arm; the products of experiments aiming at coordinating it to the Mo atom eluded isolation. I thus does not seem suitable for the synthesis of complexes with imido/olefin or imido/allyl ligands. However, products 1–3, (two of which (1, 3) were also characterised by single crystal X‐ray diffraction) are nevertheless interesting, e.g., with respect to the grafting of molybdenum complexes on the surfaces of solid supports to obtain heterogeneous oxidation catalysts.
Synthesis and Characterization of the Monomeric Sterically Encumbered Diaryls E{C6H3‐2,6‐(C6H3‐2,6‐Pri2)2}2 (E = Ge, Sn, or Pb)
Authors: Spikes Geoffrey H. , Peng Yang , Fettinger James C. , Power Philip P.
Published: May 2006

The reaction of two equivalents of LiC6H3‐2,6‐(C6H3‐2,6‐Pri2)2 with GeCl2·dioxane, SnCl2 or PbBr2 in a diethyl ether solution resulted in the isolation of the monomeric σ‐bonded diaryl tetrylene series E{C6H3‐2,6‐(C6H3‐2,6‐Pri2)2}2 (E = Ge (1), Sn (2), or Pb(3)). Compounds 1‐3 are highly sterically congested blue crystalline solids, which possess V‐shaped structures and wide interligand bond angles. The solid state structures of 1‐3 were determined by single‐crystal X‐ray methods while their solution structures were investigated by UV spectroscopy and in the cases of 2 and 3, respectively, by 119Sn and 207Pb NMR spectroscopy. The series 1‐3 constitutes the most sterically crowded examples of σ‐bonded diorgano group 14 derivatives yet isolated and, in contrast to previously reported: ER2 species, the C‐E‐C angles increase with increasing atomic number.
Nitridorhenium(V) Complexes with 1,3‐Dialkyl‐4,5‐dimethylimidazole‐2‐ylidenes
Authors: Braband Henrik , Oehlke Elisabeth , Abram Ulrich
Published: May 2006

The nitridorhenium(V) complexes [ReNCl2(PR2Ph)3] (R = Me, Et) react with the N‐heterocyclic carbenes (NHC) 1,3‐diethyl‐4,5‐dimethylimidazole‐5‐ylidene (LEt) or 1,3,4,5‐tetramethylimidazole‐2‐ylidene (LMe) in absolutely dry THF under complete replacement of the equatorial coordination sphere. The resulting [ReNCl(LR)4]+ complexes (LR = LMe, LEt) are moderately stable as solids and in solution, but decompose in hot methanol under formation of [ReO2(LR)4]+ complexes. With 1,3‐diisopropyl‐4,5‐dimethylimidazole‐5‐ylidene (Li‐Pr), the loss of the nitrido ligand and the formation of a dioxo species is more rapid and no nitridorhenium intermediate could be isolated.

The Re‐C bond lengths in [ReNCl(LEt)4]Cl of approximately 2.195Å are relatively long and indicate mainly σ‐bonding in the electron‐deficient d2 system under study.

The hydrolysis of the nitrido complexes proceeds via the formation of [ReO3N]2− anions as could be verified by the isolation and structural characterization of the intermediates [{ReN(PMe2Ph)3}{ReO3N}]2 and [{ReN(OH2)(LEt)2}2O][ReO3N].
Reactions of Silicon Atoms with Methanol: A Combined Matrix‐Spectroscopic and Density Functional Theory Study
Authors: Maier Günther , Glatthaar Jörg
Published: May 2006

The reaction of silicon atoms with methanol (4) has been studied in an argon matrix at 10 K. In the initial step a triplet n‐adduct T‐5 between a silicon atom and 4 is formed. It cannot be detected directly as long as a low concentration of 4 is used. But T‐5 must be generated since upon simultaneous irradiation during cocondensation methylsilanone (15) is found. Without irradiation T‐5 undergoes immediately O,H insertion and methoxysilylene (S‐7‐c) is isolated, which establishes a photoequilibrium between the s,trans (S‐7‐t) and s,cis form (S‐7‐c). If a high concentration of 4 is applied the silylenes exist as complexes S‐17. The next step needs photochemical activation. Products are dimethoxysilane (3) and (hydroxy)(methoxy)methylsilane (19). The picture becomes even more complicated when deuteromethanol ([D]4) is treated with silicon atoms. In this case the primarily formed n‐adduct ([D]T‐5) is stable under matrix conditions. As long as a low concentration is applied, the subsequent step has to be induced by long wavelength irradiation and leads – different from the undeuterated case – to O,CH3 insertion, giving (hydroxy)methylsilylenes ([D]S‐11‐c) and ([D]S‐11‐t). If a high concentration is used O,D insertion is preferred instead and even without irradiation the first observable products are methanol‐solvated methoxysilylenes ([D2]S‐17‐c) and ([D2]S‐17‐t). Subsequent irradiation of complexes [D2]S‐17 gives in accordance with the protonated series a mixture of [D2]3 and [D2]19. Our goal, to find a way to dimethylsilanediol ([D2]2), was finally reached by preparing silylenes [D]S‐11 in a diluted matrix, its specific solvation with [D]4 and final irradiation of complexes [D2]S‐18. The structural elucidation of all new species is based on the comparison of the experimental observations with density functional theory calculations. Upon cocondensation of silicon atoms with pure methanol at 77 K dimethoxysilane (3) and 1,1,2‐trimethoxydisilane (25) are produced. The also present methoxysilanes 22‐24 have to be regarded as secondary products of 3.
Germanium(II)‐, Zinn(II)‐ und Blei(II)‐Derivate des polycyclischen Alumosiloxans [Ph2SiO]8[Al(O)OH]4
Authors: Veith Michael , Hreleva Hinka , Gasthauer Matthias , Rammo Andreas , Huch Volker
Published: May 2006

Germanium(II)‐, Tin(II)‐ and Lead(II)‐Derivatives of the polycyclic Alumosiloxane [Ph2SiO]8[Al(O)OH]4

Five new derivatives of the polycyclic alumosiloxane [Ph2SiO]8[Al(O)OH]4 have been synthesized by replacement of the protic hydrogen atoms on the hydroxy‐groups attached to the aluminium atoms by the divalent group 14 elements germanium, tin and lead. The compounds can be divided in those with one metal atom per alumosiloxane moiety, [Ph2SiO]8[Al(O)OH]2[AlO2]M (M=Ge, Sn), and those with complete substitution of the protic hydrogen atoms by metal atoms like [Ph2SiO]8[AlO2]4M2 (M= Sn, Pb). Always one element of the series Ge, Sn, Pb is missing in the two types of compounds. Crystal structure analyses of [Ph2SiO]8[Al(O)OH]2[AlO2]2M · 2 C4H8O2 (M= Ge (1), Sn (2a)), [Ph2SiO]8[Al(O)OH]2[AlO2]2Sn · 2 THF (2b) and [Ph2SiO]8[AlO2]4M2 (M= Sn (3), Pb (4)) have been performed elucidating either polycyclic basket‐type (1, 2a, 2b) or closed polyhedral structures (3, 4).
Efficient Synthesis and Properties of Single‐Crystalline [SnTe4]4− Salts
Authors: Ruzin Eugen , Kracke Andreas , Dehnen Stefanie
Published: May 2006

Single‐crystalline K+, Rb+, and Cs+ salts of the ortho‐tellurostannate anion have been prepared by a very efficient fusing/extraction/evaporation method. The resulting compounds with the general composition [A4(H2O)n][SnTe4] can be transferred into mixed H2O/en solvates by solving the hydrates in 1,2‐diaminoethane (en) and ensuing layering by toluene. A mixed Rb+/Ba2+ salt results from a partial cation exchange of the Rb+ hydrate phase in solution. All hydrates react to polytellurides when exposed to air and represent useful starting materials for the synthesis of transition metal complexes with [SnTe4]4− groups as binary main group elemental ligands. [K4(H2O)0.5][SnTe4] (1), [Rb4(H2O)2][SnTe4] (2), [Cs4(H2O)2][SnTe4] (3), [K4(H2O)(en)][SnTe4] (4), [Rb4(H2O)0.67(en)0.33][SnTe4] (5), [Cs4(H2O)0.5(en)0.5][SnTe4] (6), and [Rb2Ba(H2O)11][SnTe4] (7) were characterized by means of X‐ray diffractometry and optical absorption spectroscopy.
Lens‐anomalies and other ophthalmic findings in a group of closely‐related angola lions (Panthera leo bleyenberghi)
Authors: Steinmetz Andrea , Eulenberger Klaus , Thielebein Jens , Buschatz Sarah , Bernhard Andreas , Wilsdorf Albrecht , Ofri Ron
Published: May 2006

After the diagnosis of bilateral, immature, nuclear, and posterior cortical cataracts in one Angola lioness, and because of the possible implications of the cataracts for a breeding program, complete ophthalmic examinations on a group of related adult Angola lions and their offspring were carried out. Five adult lions, ranging in age from 1.5–5.5 years, and five lion cubs were studied clinically. The examination included slit‐lamp biomicroscopy, indirect ophthalmoscopy, and photography. The eyes of three of the offspring were submitted for histopathologic examination and examined by light microscopy. The most significant findings were cataracts of various stages, which were observed in four adult lions and one male cub. Mild lenticular abnormalities were noted in the histopathologic examination of the lion cubs' eyes. Additional ophthalmic findings, of lesser clinical consequence, were also noted. This breeding program would benefit from further investigation by animal nutritionists and geneticists, and the animals in this group should undergo periodic ophthalmologic examinations. Zoo Biol 0:1–7, 2006. © 2006 Wiley‐Liss, Inc.
Interaction of a small heat shock protein with light‐harvesting cyanobacterial phycocyanins under stress conditions
Authors: Nakamoto Hitoshi , Honma Daisuke
Published: May 2006

Phycobiliproteins such as phycocyanins are the most abundant proteins found in cyanobacteria which are assembled to form the phycobilisome. Here, we showed that a small heat shock protein, HspA, interacts directly with phycocyanins from the cyanobacterium Synechococcus sp. strain PCC 7942 in vitro and suppresses inactivation of their light‐harvesting functions due to heat denaturation in the presence of hydrogen peroxide. Under the denaturing conditions, phycobilisomes were de‐assembled to lighter complexes and then aggregated. HspA associated with phycocyanins in the dissociated complexes, and suppressed the aggregation. The specific interaction between a small heat shock protein and phycocyanins was further supported by the fact that HspA and α‐crystallin protected isolated phycocyanins from denaturation, while HtpG and lysozyme did not. The maximum protection was observed at a molar ratio of four HspA monomer per one phycocyanin (αβ) monomer.
Macrophage activation increases the invasive properties of hepatoma cells by destabilization of the adherens junction
Authors: Lin Chieh-Yu , Lin Chien-Jung , Chen Kuo-Hsing , Wu Jiann-Chun , Huang Shih-Horng , Wang Seu-Mei
Published: May 2006

Tumor‐associated macrophages play an important role in tumor progression, but whether they exert a tumor‐progressive effect remains controversial. Here, we demonstrated that activated macrophage‐conditioned medium (AMCM) obtained from RAW macrophages (RAW/AMCM) induced epithelial‐mesenchymal transition (EMT) and stimulated the migratory and invasive activities of HepG2 cells, whereas control conditioned media had no effect. Epithelial‐cadherin (E‐cadherin) and β‐catenin staining patterns were altered at the adherens junctions by RAW/AMCM treatment, with an approximately 50% decrease in E‐cadherin and β‐catenin in the cell membrane. Importantly, levels of β‐catenin‐associated E‐cadherin were also decreased. Following RAW/AMCM treatment, enhanced activation of c‐Src was seen prior to increased tyrosine phosphorylation of β‐catenin, and this led to the destabilization of adherens junctions. Pretreatment of HepG2 cells with the Src kinase inhibitor, PP2, completely abolished the effects of RAW/AMCM on the EMT, migration, invasion, and expression and association of E‐cadherin and β‐catenin. AMCMs obtained from human THP‐1 monocytes and mouse peritoneal macrophages also caused disassembly of the adherens junctions and migration of HepG2 cells. Furthermore, inhibition of the epidermal growth factor receptor (EGFR) with gefitinib partially prevented the downregulation of E‐cadherin and β‐catenin at the adherens junctions and migration behavior induced by RAW/AMCM. Our results suggest that activated macrophages have a tumor‐progressive effect on HepG2 cells which involves the c‐Src‐ and EGFR‐dependent signaling cascades.
Pigment epithelium‐derived factor (PEDF) inhibits advanced glycation end product (AGE)‐induced C‐reactive protein expression in hepatoma cells by suppressing Rac‐1 activation
Authors: Yoshida Takafumi , Yamagishi Sho-ichi , Nakamura Kazuo , Matsui Takanori , Imaizumi Tsutomu , Takeuchi Masayoshi , Ueno Takato , Sata Michio
Published: May 2006

Serum levels of advanced glycation end products (AGEs) are associated with an acute phase reactant, C‐reactive proteins (CRP) in diabetic patients. However, whether AGEs could directly stimulate hepatic CRP production remains to be elucidated. We found here that AGEs upregulated CRP mRNA levels in cultured Hep3B cells via Rac‐1 activation, which was blocked by pigment epithelium‐derived factor (PEDF). Our present study suggests that AGEs are one of the potent inducers of CRP and that PEDF may work as an anti‐inflammatory agent against AGEs in the liver.
Engrailed: Complexity and economy of a multi‐functional transcription factor
Authors: Morgan Richard
Published: May 2006

Engrailed is a homeodomain‐containing transcription factor with numerous, overlapping roles in neural development. Its multifunctional nature depends upon an extremely diverse group of molecular functions including the ability to regulate both transcription and translation, and to be released from and internalized by cells. Recent findings have shown how some of these functions relate to specific roles in development and disease.
Thermodynamics and stability of the PAAD/DAPIN/PYRIN domain of IFI‐16
Authors: Dalal Kush , Pio Frederic
Published: May 2006

The PAAD domain is a conserved domain recently identified in more than 35 human proteins that are involved in apoptosis and inflammatory signaling pathways. Structural studies have confirmed that this domain belongs to the death domain superfamily which includes PAAD/CARD/DED/DD families. Recently, the 3D structures determined by NMR of NALP1 and ASC PAAD domain, members of the PAAD family, have shown that it is composed of a 6 helix bundle as with other death domain family members. However, helix‐3 in the solved structures is unordered in solution. In this study we compare the thermodynamic, folding and stability properties of different members of the PAAD and CARD families and investigate structural conformational changes induced by the helix inducers trifluoroethanol and SDS on the PAAD domain of IFI16 and on the CARD domain of RAIDD. We show that inside the PAAD and CARD families, members have similar thermodynamic properties, however, the ΔG of folding for PAAD and CARD members are, respectively, −1.4 and −5.5 kcal mol−1. This difference is attributed to less alpha helical content for PAAD due to the unfolding of helix‐3 that lowers bonded energy and increases disorder when compared to CARD members. Despite identical fold between PAAD and CARD families but limited sequence identity, there are striking differences in the thermodynamics of both families.
Transcription regulation of the α‐glucanase gene agn1 by cell separation transcription factor Ace2p in fission yeast
Authors: Dekker Nick , de Haan Annett , Hochstenbach Frans
Published: May 2006

During the final stage of the cell division cycle in the fission yeast Schizosaccharomyces pombe, transcription factor Ace2p activates expression of genes involved in the separation of newly formed daughter cells, such as agn1
+, which encodes the α‐glucanase Agn1p. The agn1 promoter contains three copies of the nucleotide sequence motif CCAGCC, whose presence seems to correlate with Ace2p‐mediated transcription activation. Here, we describe a simple plate‐based assay utilizing as a reporter the secreted glucoamylase of Arxula adeninivorans to investigate the function of this motif. We show that not all three repeats, but only the two most proximal to the transcription start point, act as an upstream activating sequence (UAS). Finally, we demonstrate that this UAS is essential for agn1 promoter activity in vivo.
Common Problems of Urination in Nonpregnant Women: Causes, Current Management, and Prevention Strategies
Authors: O'Dell Katharine K. , Labin Lisa C.
Published: May 2006

This article uses a case‐based approach to review common problems of urination in nonpregnant women, including overactive bladder; stress, urge, and mixed incontinence; and retention and prolapse. Up‐to‐date clinical issues related to assessment, diagnosis, treatment, and follow‐up are reviewed, with a discussion of underlying pathophysiology and prevention strategies. Suggestions are made for relevant curriculum content at both the basic and advanced levels of advanced practice education.
Metabolic Syndrome: Screening, Diagnosis, and Management
Authors: Miller Elissa Lane , Mitchell Angela
Published: May 2006

Metabolic syndrome, a growing issue in women's health, is a cluster of health findings that increase the risk of cardiovascular events. The prevalence of metabolic syndrome is higher in women and is linked to several conditions unique to women's health, including polycystic ovary syndrome, gestational diabetes, pregnancy‐induced hypertension, and female sexual dysfunction. Risk factors, screening strategies, and therapeutic management of metabolic syndrome in women are discussed.
MANIFESTATIONS OF FUTURE HEALTH RISKS DURING PREGNANCY
Authors: Snapp Carol , Snapp Carol A.
Published: May 2006

Kaaja RJ, Greer IA. Manifestations of chronic disease during pregnancy. JAMA 2005;294:2751–7.
Assessment and Management of the Obese Adult Female: A Clinical Update for Providers
Authors: Salazar Susan S.
Published: May 2006

Obesity is epidemic in the United States, affecting 61% of adults and 14% of children. Today's health care providers should recognize obesity as a chronic disease and offer up‐to‐date information and management. Treatment options currently available are diet and behavior modification, medications, and surgical procedures. Implications for clinical practice include recognition of the problems associated with obesity, education of current patients as well as young women who may become patients, and appropriate diagnosis and management or referral.
Coblation Adenotonsillectomy: An Improvement Over Electrocautery Technique?
Authors: Glade Robert S. , Pearson Susan E. , Zalzal George H. , Choi Sukgi S.
Published: May 2006

OBJECTIVES

To compare postoperative complication rates of coblation and electrocautery adenotonsillectomies.

STUDY DESIGN

Retrospective chart review.

RESULTS

From January 2000 to June 2004, 1997 pediatric patients underwent adenotonsillectomy. 745 coblation, and 1252 electrocautery tonsillectomies were performed. Primary bleed, secondary bleed, and dehydration were seen in 3, 35, and 23 coblation, and 9, 41, and 64 electrocautery tonsillectomies, respectively. Data analysis revealed no significant difference in primary and secondary hemorrhage rate, but a higher dehydration rate in the electrocautery group (P = 0.0423). A total of 602 coblation, 763 curette/cautery, and 632 electrocautery adenoidectomies were performed. Neck pain was seen in 0, 17, and 3 patients, respectively. Data analysis showed a higher incidence of neck pain with the curette/cautery technique compared with coblator and cautery techniques (P = 0.0006 and P = 0.0119, respectively).

CONCLUSIONS

Coblation tonsillectomy had similar rates of primary and secondary hemorrhage when compared with electrocautery tonsillectomy but a lower incidence of postoperative dehydration. Coblation adenoidectomy caused less postoperative neck pain than curette/cautery adenoidectomy without significant advantage over cautery adenoidectomy.

EBM rating: B‐3b
Sudden Sensorineural Hearing Loss: Long‐term Follow‐up Results
Authors: Psifidis Anestis D. , Psillas George K. , Daniilidis Jiannis Ch.
Published: May 2006

OBJECTIVE

This study describes the long‐term outcome of patients suffering from sudden sensorineural hearing loss (SSHL) after an initial combined therapy of steroids with vasodilators.

STUDY DESIGN AND SETTING

Eighty cases were retrospectively reviewed to evaluate the long‐term audiometric data and to statistically assess the value of specific clinical parameters. The persistent long‐term otoneurologic manifestations associated with SSHL were also reported.

RESULTS

In the long‐term period, hearing level remained stable 2 months after the onset of SSHL. Patients complained of persistent tinnitus (36%), fluctuant hearing loss (8.7%), dizziness (8.7%), and classical Meniere's triad in 2.5% of cases. Profound and total SSHL associated with vertigo are poor prognostic indicators.

CONCLUSIONS

In terms of cost‐effectiveness, a steroid‐vasodilator therapy for SSHL for >2 months is not recommended because no additional effect was evidenced. Persistent otoneurologic manifestations, mainly tinnitus or dizziness are relatively common, particularly in patients with severe to total SSHL.

EBM rating: C‐4
Evaluation of Super‐High‐Dose Steroid Therapy for Sudden Sensorineural Hearing Loss
Authors: Aoki Daisuke , Takegoshi Hideki , Kikuchi Shigeru
Published: May 2006

OBJECTIVE

To determine the efficacy of a high‐dose steroid regimen for patients with sudden sensorineural hearing loss (SSNHL) and to evaluate the relationship between outcome and initial steroid dose.

STUDY DESIGN AND SETTING

We conducted a retrospective study of 112 patients presenting to Saitama Medical Center. Patients received tapering courses of hydrocortisone (HC) with an initial dose of either 1200 mg or 600 mg.

RESULTS

More than 87% of patients had recovery of hearing. When hearing stabilized, there were no significant differences between the 1200 mg and 600 mg groups in terms of hearing outcome (P > 0.05). However, at completion of treatment, the 1200 mg group exhibited significantly superior complete recovery rate and improvement rate (P < 0.05).

CONCLUSION

Application of our treatment protocol of a tapered course of 1200 mg HC significantly and rapidly improves recovery outcomes in patients of SSNHL.

EBM rating: C‐4
Nasal health in Down syndrome: A cross‐sectional study
Authors: Chen Margaret A. , Lander Timothy R. , Murphy Claire
Published: May 2006

OBJECTIVE

To investigate peripheral nasal pathology as a contributor to olfactory impairment in DS.

STUDY DESIGN

Twenty DS and 16 non‐DS subjects were recruited. Nasal history and symptoms were assessed by self‐report or informant. Olfactory threshold, odor identification, and nasal endoscopy were assessed on each subject.

RESULTS

DS subjects were impaired on olfactory threshold (P < 0.0001) and odor identification (P < 0.001). Although DS subjects trended toward upper‐respiratory infections, sleep‐disordered breathing, and nasal itching, differences were not significant (P = 0.07, 0.06, and 0.058, respectively). There were no significant differences on self‐reported nasal history or symptoms. Endoscopy showed equivalent health in DS and control subjects.

CONCLUSION

This DS population shows olfactory impairment. However, nasal health is comparable in DS subjects and controls. Nasal dysfunction is unlikely to contribute to olfactory impairment in DS.

SIGNIFICANCE

Olfactory deficits in DS appear to be secondary to central, rather than rhinologic, pathology.

EBM rating: B‐2b
Adult Spontaneous CSF Otorrhea: Correlation with Radiographic Empty Sella
Authors: Prichard Christopher N. , Isaacson Brandon , Oghalai John S. , Coker Newton J. , Vrabec Jeffrey T.
Published: May 2006

OBJECTIVE

To determine the prevalence of radiographic empty sella in patients with spontaneous cerebrospinal fluid (CSF) otorrhea.

STUDY DESIGN AND SETTING

Retrospective case series of adult patients with CSF otorhinorrhea at an academic tertiary medical center. Patients with history of skull base surgery, trauma, tumor, or chronic ear disease were excluded. Available imaging studies were reviewed with attention to the sella turcica.

RESULTS

Eight patients were diagnosed with spontaneous CSF otorrhea. Five of seven patients with adequate imaging studies (71%) had a radiographic empty sella. Seven of eight patients were clinically obese, with a body mass index BMI >30 kg/m2.

CONCLUSIONS

Empty sella is a common radiologic finding in patients with spontaneous CSF otorrhea. This supports the theory that increased intracranial pressure contributes to development of spontaneous CSF otorrhea.

SIGNIFICANCE

Radiographic empty sella predicts elevated intracranial pressure, which may require further evaluation and treatment in patients with spontaneous CSF otorrhea.

EBM rating: C‐4
A Survey of Parental Views Regarding their Child's Hearing Loss: A Pilot Study
Authors: Park Albert H. , Warner Jonathan , Sturgill Nanette , Alder Stephen C.
Published: May 2006

OBJECTIVE

Assess parental perceptions of their child's sensorineural hearing loss care.

METHODS

Families of pediatric patients diagnosed with a sensorineural hearing loss from 2000 to 2004 were sent a survey asking about their experiences with their child's hearing loss.

RESULTS

One hundred eight of 389 families surveyed were studied. Thirteen percent did not know the results of the newborn screening. Twenty‐two percent of the primary care physicians were not involved in the child's hearing evaluation. Forty percent of the patients underwent 4 or more audiologic tests before a diagnosis. The most common reason for delayed diagnosis was difficulty in obtaining an appointment with an audiologist. Sixty‐two percent of families had difficulties obtaining hearing aids, and 58% noted difficulties obtaining cochlear implants.

CONCLUSIONS

Families reported multiple obstacles to obtain timely diagnosis and treatment. Otolaryngologists may need to be more involved in the evaluation and treatment of these patients.

EBM rating: C‐4
Snoring Significance in Patients Undergoing Home Sleep Studies
Authors: Hunsaker Darrell H. , Riffenburgh Robert H.
Published: May 2006

OBJECTIVE

To analyze the impact of snoring, independent of obstructive sleep apnea syndrome on patients referred for home sleep studies and to report a new technology for the reporting of snoring, using sophisticated sound collection and noise‐canceling technology.

STUDY DESIGN AND SETTING

A retrospective statistical review of consecutive anonymous data compiled from questionnaires and digital data of snoring loudness and duration measured at the upper lip during unattended home sleep studies in 4,860 patients referred for snoring and sleep‐disturbed breathing.

RESULTS

A strong relationship exists between a history of snoring and complaints of daytime sleepiness (80%), obesity (73%), and chronic fatigue (78%) (all yield P < 0.001). By contrast, only 42% to 48% of patients without these symptoms complain of snoring. In 3 multiple‐regression analyses, the percent of time snoring, average loudness, and peak loudness are all significantly predicted by the apnea hypopnea index (all P < 0.003), body mass index (all P < 0.001), and age (P = 0.014). Daytime sleepiness was strongly predicted by percent time snoring (P = 0.014), weakly by average loudness (P = 0.046), and not at all by peak loudness (P = 0.303).

CONCLUSION

By using a pair of microphones placed at the upper lip, one that samples breath sounds and the other ambient sound and artifact noise, the NovaSOM QSG measures snoring while canceling ambient noise. The clinical impact of snoring on the patient as well as the bed partner, independent of obstructive sleep apnea syndrome, is an unrecognized factor in sleep‐disturbed breathing.

SIGNIFICANCE

Measurable criteria to define snoring are suggested. Snoring loudness is not measured in most laboratory Polysomnograms.

EBM rating: B‐3b
Who chooses whom? Syndication, skills and reputation
Authors: Tykvová Tereza
Published: May 2006

We develop a model focusing on the dynamic aspect of syndication, namely, the know‐how transfer between syndication partners and their ability to learn. The core of the analysis checks whether reputational concerns outweigh the temptation to renege on a given contract. Throughout the paper, we investigate two key topics. The first consists of the conditions under which investors syndicate their deals. The second focuses on who chooses whom. Sometimes, the syndication is impeded because the financier believes that his partner has strong incentives to either renege on a contract (hold‐up problem) or to shirk (moral hazard problem).
BLAZING A TRAIL: THE AFRICAN PROTOCOL ON WOMEN'S RIGHTS COMES INTO FORCE
Authors: BANDA FAREDA
Published: May 2006

The entry into force of the Protocol to the African Charter on Human and Peoples' Rights on the Rights of Women in Africa, 2003 on 25 November, 2005, marked the culmination of years of lobbying for a document which would promote and protect the human rights of the continent's women by African women's rights advocates. This commentary provides a brief historical overview of the process leading up to the adoption of the Protocol by the African Union in Maputo in July 2003 before moving on to consider its substantive provisions.
Maintenance of continental boundary-layer shear through counter-gradient vorticity flux in a barotropic model
Authors: Bidlot Jean-Raymond , Stern Melvin E.
Published: May 2006

The use of a classical eddy parametrization in the analysis of continental boundary currents leads to the diffusion of momentum and relative vorticity and fails to recognize that the relevant eddies are dominated by the conservation of potential vorticity, which in turn may produce an increase in the mean relative vorticity. To illustrate this effect, we examine a non-inflected barotropic shear flow destabilized by the cross-steam variation in the bottom topògraphy of a continental slope. The finiteamplitude evolution of the waves is analysed in a simple model with a step-like bottom topography and with a piecewise-uniform potential vorticity distribution. The increase in maximum mean vorticity is computed for various values of the Rossby number and the topographic elevation, and it is suggested that a similar effect, taking into account the isopycnal topography as well as the isobaths, could maintain the large inshore shear of the Gulf Stream. Cross-shelf transport of different water ‘types’ (i.e. potential vorticity and passive tracers) are also computed and suggested to be pertinent to the more realistic oceanic problem involving baroclinic effects. The numerical calculation employs the well-known method of contour dynamics, and the Green's function appropriate for the step-like topography is derived.
Tectonics at the axis of the very slow spreading Southwest Indian Ridge: Insights from TOBI side‐scan sonar imagery
Authors: Gomez Olga , Briais Anne , Sauter Daniel , Mendel Véronique
Published: May 2006

We present the analysis of the deformation in the axial valley of two contrasted regions of the very slow spreading Southwest Indian Ridge based on side‐scan sonar images. Our objective is to investigate how the obliquity is accommodated along the system. We show that the robust magmatic segments have axial valleys and major faults subperpendicular to spreading. The other sections show fault populations with various degrees of obliquity, often arranged in left‐stepping echelons, accommodating part of the strike‐slip deformation. Side‐scan sonar reveals the presence of a corrugated surface near 59°E interpreted to be an incipient detachment fault. We show that the large width of the SWIR oblique sections, and the difference in tectonic style between the robust volcanic segments and the magma‐starved sections, is accounted for by large variations in the thickness of the brittle lithosphere. We suggest that the emplacement of mantle rocks in the surveyed amagmatic ridge sections can occur by alternating conjugate faults. Serpentinization of outcropping peridotites might also play a significant role in the development of faults in thin crust regions and the distribution of deformation in space and time.
Dst model for 1995–2002
Authors: Temerin M. , Li Xinlin
Published: May 2006

The Dst index is predicted on the basis of the solar wind for the years 1995–2002 using an update of the previous Temerin and Li [2002] prediction model for Dst. The updated model is based on additional data from the years 2000–2002 corresponding to the maximum of the solar cycle and includes several large magnetic storms. For this 8‐year period, the linear correlation between the model and the Dst index is 0.956, the prediction efficiency is 0.914, and the RMS error of the prediction is 6.65 nT (nanoTesla). An analysis of some of the error in the model indicates that at least 25% of the remaining error is due to the effect on the Dst index of a portion of the Sq ionospheric current system and that close to 99% of the variance of Dst index due to magnetospheric currents is predictable. An examination of 10‐day intervals around the six largest magnetic storms for which there is good solar wind data shows prediction efficiencies between 0.93 and 0.98 and linear correlation coefficients between 0.96 and 0.99. It is suggested that the annual variation in the Dst index is mainly due to magnetopause and ring currents and the location of the magnetometer stations used to calculate the Dst index. The dependence of the model on the solar wind implies that magnetospheric activity depends on the solar wind approximately in proportion to the square root of the density, square of the velocity, and linearly with the interplanetary magnetic field (IMF). In addition, there is strong dependence on the direction of IMF such that magnetic activity depends approximately on the sixth power of the sine of half the IMF clock angle, where the IMF clock angle is angle of the IMF in the plane perpendicular to the solar wind velocity measured from the northward direction. The model has also strong dependence on the angle between the dipole axis and the solar wind velocity which explains, in part, the seasonal dependence of magnetospheric activity. Overall, the updated model further demonstrates that the large‐scale currents that affect the Dst index are well controlled by solar wind variations.
Evaluation of the air‐sea bulk formula and sea‐surface temperature variability from observations
Authors: Vickers Dean , Mahrt L.
Published: May 2006

Eddy‐correlation fluxes are compared to air‐sea fluxes predicted by a widely used bulk flux formulation without wave‐state effects. Systematic discrepancies are found. For example, the model approximately equates the roughness lengths for heat and moisture; however, the observed roughness length for heat (zoh) exceeds that for moisture (zoq) by an order of magnitude or more, except in the strongest wind‐speed conditions. This is apparently due to the dynamic nature of temperature, which dominates buoyancy generation of turbulence in these data sets. The observed correlation between temperature and vertical velocity fluctuations generally exceeds that for moisture. For 10‐m wind speeds above a threshold value of 12 m s−1, zoq exceeds zoh apparently owing to enhanced moisture flux associated with the onset of wave breaking coupled with advection of cold dry air from land. In near‐collapsed turbulence, the observed momentum flux is smaller than predicted, and there is no clear indication of a smooth flow viscous regime. The scatter between observed and bulk fluxes generally decreases with averaging the observed fluxes over greater length scales even with variations in sea‐surface temperature (SST). The reduction in random flux sampling errors more than compensates for capturing increased surface heterogeneity with increasing averaging scale. Since similarity theory does not apply to heterogeneous surfaces, the bulk model does break down in the extreme case where the averaging window includes a sharp SST front. The response of the flow to changes in SST is presented for different amplitudes of SST variability. The change in vertical structure and acceleration of the low‐level wind over warm pools is discussed.
Determination of local surface properties using Mars Express bistatic radar
Authors: Simpson Richard A. , Tyler G. Leonard , Pätzold Martin , Häusler Bernd
Published: May 2006

Dual‐frequency bistatic radar experiments were conducted with Mars Express at a rate of one to two per month during 2005. Each observation provided power measurements of orthogonally polarized surface echoes at one specular point; the ratio of these components yielded values of the dielectric constant in the range 2.0 < ɛ < 4.0. Doppler sorting of X‐band (wavelength λ = 3.6 cm) echoes was used to achieve one‐dimensional surface resolutions of about 20 km. Although much weaker, simultaneous S‐band (13‐cm) echoes yielded dielectric constants that are 10–50% higher than 3.6 cm echoes, consistent with deeper surface penetration.
Missing organic carbon in Eocene marine sediments: Is metabolism the biological feedback that maintains end‐member climates?
Authors: Olivarez Lyle Annette , Lyle Mitchell W.
Published: May 2006

Ocean chemistry is affected by pCO2 in the atmosphere by increasing the dissolution of solid calcium carbonate and elevating the dissolved inorganic carbon concentrations in seawater. Positive feedbacks between the ocean and atmosphere can maintain high atmospheric pCO2 and affect global climate. We report evidence for changes in the oceanic carbon cycle from the first high‐quality organic carbon (Corg) data set of Eocene sediments beneath the equatorial Pacific upwelling region (Leg 199 of the Ocean Drilling Program). Eocene Corg mass accumulation rates (MARs) are 10 times lower than Holocene rates, even though expected Corg MARs estimated from biogenic‐barium MARs (an indicator of biological production) equal or exceed modern fluxes. What happened to the missing Corg? Recent advances in ecology and biochemical kinetics show that the metabolism of nearly all animals, marine and terrestrial, is positively correlated by first principles to environmental temperatures. The approximately 10°C abyssal temperature difference from Eocene to Holocene should have radically reduced pelagic Corg burial, as we observe. We propose that higher basal metabolism and nutrient utilization/recycling rates in the Eocene water column and surface sediments precluded Corg sediment burial in the pelagic ocean. Increased rates of metabolism, nutrient utilization, and lowered Corg sedimentation caused by increased temperature may have acted as a biological feedback to maintain high atmospheric pCO2 and hothouse climates. Conversely, these same parameters would reverse sign to maintain low pCO2 when temperatures decrease, thereby maintaining “icehouse” conditions during cold climate regimes.
Understanding parameter sensitivity and its management implications in watershed‐scale water quality modeling
Authors: Zheng Yi , Keller Arturo A.
Published: May 2006

Because of uncertainty and variability in input parameter values, watershed‐scale water quality modeling can result in significant output uncertainty. Quantifying this uncertainty is very important for policy makers and stakeholders who rely on the output of these models for watershed management. Given the large number of parameters in these complex models, a preliminary sensitivity analysis is needed before the uncertainty analysis. A few sensitivity studies have been conducted for watershed models, but efficiently selecting critical parameters for the uncertainty analysis remains an issue. This study aimed to (1) develop a framework for systematically conducting a preliminary sensitivity analysis for complex watershed models using generalized sensitivity analysis (GSA) as a global technique and (2) evaluate the relevance of incorporating management concerns in the preliminary sensitivity analysis and its impact on parameter selection. Although the proposed approach is valid for any complex watershed model, for this study the Watershed Analysis Risk Management Framework (WARMF) model was implemented using data from the Santa Clara River in southern California. To simulate hydrology, sediment, and pesticide transport, 121 parameters are needed for a single catchment/reach combination; an efficient selection method is paramount for an uncertainty analysis. The results show that GSA can be implemented efficiently, yielding insights into model and parameter behavior. The sensitivity analysis must consider management concerns early on in the process to identify parameters and parameter values that can influence management decisions. The number of parameters that must be considered in a subsequent uncertainty analysis was significantly reduced. This study also provides guidance for future research on parameter sensitivity and uncertainty in complex watershed models.