bluuebunny/crossref_metadata_2025_split huggingface dataset:
Laser Surface Modification of Ti—6Al—4V: Wear and Corrosion Characterization in Simulated Biofluid
Authors: Singh Raghuvir , Kurella A. , Dahotre Narendra B. 
Published: July 2006

Laser surface melting (LSM) of Ti—6Al—4V is performed in argon to improve its properties, such as microstructure, corrosion, and wear for biomedical applications. Corrosion behavior is investigated by conducting electrochemical polarization experiments in simulated body fluid (Ringer's solution) at 37 C. Wear properties are evaluated in Ringer's solution using pin-on-disc apparatus at a slow speed. Untreated Ti—6Al—4V contains α+β phase. After laser surface melting, it transforms to acicular α embedded in the prior β matrix. Grain growth in the range of 65—89 µm with increase in laser power from 800 to 1500 W due to increase in associated temperature is observed. The hardness of as-laserprocessed Ti—6Al—4V alloy is more (275—297 HV) than that of the untreated alloy (254 HV). Passivation currents are significantly reduced to <4.3 µA/cm2 after laser treatment compared to untreated Ti—6Al—4V (≈12 µA/cm2). The wear resistance of laser-treated Ti—6Al—4V in simulated body fluid is enhanced compared to that of the untreated one. It is the highest for the one that is processed at a laser power of 800 W. Typical micro-cutting features of abrasive wear is the prominent mechanism of wear in both untreated and as-laser-treated Ti—6Al—4V. Fragmentation of wear debris assisted by microcracking was responsible for mass loss during the wear of untreated Ti—6Al—4V in Ringer's solution.
XIAP targeting sensitizes Hodgkin lymphoma cells for cytolytic T-cell attack
Authors: Kashkar Hamid , Seeger Jens-Michael , Hombach Andreas , Deggerich Anke , Yazdanpanah Benjamin , Utermöhlen Olaf , Heimlich Gerd , Abken Hinrich , Krönke Martin 
Published: July 2006

AbstractThe immunosurveillance of Hodgkin lymphoma (HL) by cytotoxic T lymphocytes (CTLs) is insufficient, and the clinical experience with adoptive transfer of CTLs is limited. We have previously reported that defects in mitochondrial apoptotic pathways and elevated XIAP expression confer resistance to different apoptotic stimuli in HL cells. Here, we aimed to develop molecular strategies to overcome the resistance of HL cells against CTL-mediated killing via granzyme B (grzB). In HL cells, grzB-induced mitochondrial release of proapoptotic Smac is blocked, which results in complete abrogation of cytotoxicity mediated by CTLs. Cytosolic expression of recombinant mature Smac enhanced caspase activity induced by grzB and restored the apoptotic response of HL cells. Similarly, down-regulation of XIAP by RNA interference markedly enhanced the susceptibility of HL cells for CTL-mediated cytotoxicity. XIAP gene knockdown sensitized HL cells for killing by antigen-specific CTLs redirected by grafting with a chimeric anti-CD30scFv-CD3zeta immunoreceptor. The results suggest that XIAP targeting by Smac agonists or XIAP-siRNA can be used as a synergistic strategy for cellular immunotherapy of Hodgkin lymphoma.
Type I interferons directly regulate lymphocyte recirculation and cause transient blood lymphopenia
Authors: Kamphuis Elisabeth , Junt Tobias , Waibler Zoe , Forster Reinhold , Kalinke Ulrich 
Published: July 2006

AbstractEarly viral infection is often associated with lymphopenia, a transient reduction of blood lymphocyte counts long before the onset of clinical symptoms. We have investigated lymphopenia in mice infected with vesicular stomatitis virus (VSV) or treated with the Toll-like receptor (TLR) agonists poly(I:C) and R-848. In all cases analyzed, lymphopenia was critically dependent on type I interferon receptor (IFNAR) signaling. With the use of bone marrow–chimeric mice, radioresistant cells, such as stroma and endothelium, could be excluded as type I interferon (IFN-α/β) targets for the induction of lymphopenia. Instead, adoptive transfer experiments and studies in conditionally gene-targeted mice with a B- or T-cell–specific IFNAR deletion demonstrated that IFN-α/β exerted a direct effect on lymphocytes that was necessary and largely sufficient to induce lymphopenia. Furthermore, after treatment with R-848, we found that other cytokines such as TNF-α also played a role in T-cell lymphopenia. Investigation of the molecular mechanism revealed that lymphopenia was mainly independent of G protein–coupled receptors (GPCRs) and chemokines. In an adhesion assay, B cells of poly(I:C)–treated mice showed moderately increased adhesion to ICAM-1 but not to VCAM-1. In conclusion, our data identify a new effect of direct IFN-α/β stimulation of lymphocytes that profoundly affects lymphocyte redistribution.
Heterogeneity of pneumococcal phase variants in invasive human infections
Authors: Serrano I , Melo-Cristino J , Ramirez M 
Published: July 2006

Abstract

Background

Streptococcus pneumoniae can be carried asymptomatically in the nasopharynx of its human host but can also cause a wide range of infections. A role for pneumococcal phase variants in the different lifestyles of this bacterium has been suggested but no systematic survey of the colony phenotypes of isolates associated with human infections has been undertaken.

Results
We report the colony opacity phenotypes of a genetically diverse set of 304 invasive isolates representing 10 serotypes. Over half of the isolates (52%) presented the opaque phenotype whereas transparent variants accounted for only 26% of the total. However, the frequency of recovery of each phase variant was not uniform, while serotypes 1, 4, 12B and 23F presented the opaque phenotype more frequently than expected by chance, serotypes 3 and 14 where less frequently associated with this phenotype.

Conclusion
The opaque phenotype was the most frequent phenotype found among invasive isolates. An unexpected and equally important finding is the variability of the dominant opacity phenotype found among serotypes. This observation highlights the heterogeneity of opacity phenotypes in invasive isolates and lends further support to the proposal that other factors, in addition to the site of isolation, determine the opacity phenotype of a given isolate. The association between serotype and colonial opacity could help explain epidemiological differences observed among pneumococcal serotypes such as a higher invasive disease potential.
Unexpected death after headache due to a colloid cyst of the third ventricle
Authors: Shaktawat Sameer S , Salman Walid D , Twaij Zuhair , Al-Dawoud Abdul 
Published: July 2006

Abstract

Background
Colloid cysts of the third ventricle are rare benign intracranial non-neoplastic cysts. Headache is the most common symptom. We present a case of sudden death due to colloid cyst in a 17 year old female who had symptoms of intermittent headaches.

Case presentation
A 17 year old female presented with intermittent mild headaches for a period of two years. She complained of severe headache in the night and was found unresponsive the next morning. Resuscitation team was called on site but the patient was already dead. At post mortem examination a dilated ventricular system was found with a colloid cyst of the third ventricle.

Conclusion
This report highlights the difficulty in the diagnosis and importance of recognizing colloid cyst of the third ventricle which should be in the differential diagnosis of headaches in children and young adults and of hydrocephalus at autopsy
Critical Phenomena in a Surfactant/Water/Oil System. Basic Study on the Correlation between Solubilization, Microemulsion, and Ultralow Interfacial Tensions
Authors: Kunieda Hironobu , Friberg Stig E 
Published: July 2006

Abstract
The phase equilibrium in C8H17(OCH2CH2)3OH/water/decane system was studied at 13.6, 15.8, 21.5, 26.0, and 30.0 °C. An upper critical solution point for the surfactant and oil phases, and a lower critical solution point for the surfactant and water phases were found. Strong critical opalescence was observed in the vicinity of the critical points. In a temperature range between two critical points, a three-phase region appeared due to the superposition of three miscibility gaps, i.e., 1) surfactant+water; 2) surfactant+oil, and 3) oil+water phases. The correlations between the phase equilibria and the ultralow interfacial tensions were straightforward. An ionic surfactant/cosurfactant/brine/oil system gave similar phase equilibria as the nonionic surfactant system, but the effect of temperature was the reverse.
Transport Number of Ions in Water/DMF Solvents and Reference Electrode for Electrochemical Measurements in Nonaqueous Media
Authors: Takaoka Kazunori , Bates Roger G 
Published: July 2006

Abstract
The transport number of the ions, t±, of (C2H5)4NClO4, NaClO4, NaCl, KCl, and HCl in N,N-dimethylformamide(DMF)–water solvents were determined by the agar–salt bridge method. In order to compare this method, t+(HCl)’s in DMF–water media were measured by both the Hittorf method and the concentration cell method. Good agreement among these methods leads to the conclusion that t+(KCl) and t−(KCl) are nearly equal in the whole range of DMF–water media. The results suggest that potentials obtained in nonaqueous polarography with the bridged SCE by correcting the bridge potential with a slow flowing type aqueous SCE are always referred to the ordinary aqueous SCE.
The Crystal Structure and Luminescence Properties of Europium(II) Haloborates
Authors: Machida Ken-ichi , Adachi Gin-ya , Moriwaki Yoshikazu , Shiokawa Jiro 
Published: July 2006

Abstract
The crystal structures of Eu2B5O9X (X=Cl and Br) were determined by the method of X-ray diffraction analysis and refined by the least-square method to give R=0.054 for 1967 observed reflections of Eu2B5O9Cl and R=0.047 for 1979 observed reflections of Eu2B5O9Br. These haloborates are isostructural and belong to the orthorhombic (pseudotetragonal) system, with the Pnn2 space group and with four formula units in a cell of those dimensions: a=11.364(3), b=11.301(3), and c=6.504(2) Å for Eu2B5O9Cl, and a=11.503(3), b=11.382(3), and c=6.484(2) Å for Eu2B5O9Br. The structure consists of a three-dimensional (B5O9)∞ network, the B5O12 groups of three BO4 tetrahedra and two BO3 triangles being linked together with one another. The Eu and X atoms are located alternately in tunnels of the (B5O9)∞ network extending along the c axis. Each Eu atom is surrounded by two X atoms and seven O atoms, and is isolated from the neighboring Eu atoms attributable to borate units and X atoms. This arrangement of anions around Eu atoms relates to the fact that the Eu2+-activated phosphors of alkaline earth analogs give emissions with a high quantum efficiency.
The Crystal Structure and Magnetic Property of Europium(II) Orthoborate
Authors: Machida Ken-ichi , Adachi Gin-ya , Hata Hajime , Shiokawa Jiro 
Published: July 2006

Abstract
The europium(II) orthoborate Eu3(BO3)2 is trigonal, space group R\bar3c, with a=9.069(1), c=12.542(2) Å and Z=6. The structure has been refined to R=0.082 for 259 observed reflections with isotropic thermal parameters. The borate contains isolated and planar triangle BO33− ions, the anions and Eu atoms being hexagonally packed along c. Each Eu atom is surrounded by 8 oxygens with Eu–O distances varying from 2.36 to 2.95 Å. The interatomic distances between Eu atoms are 3.509–4.200 Å for 8 nearest Eu neighbors and 4.831–5.450 Å for 6 second-nearest Eu neighbors. The 6 nearest Eu neighbors with the interatomic distances of 3.509 and 3.778 Å and the 4 second-nearest Eu neighbors with the Eu–O–Eu angle of 166.0° are effective for the magnetic exchange and superexchange interactions between Eu2+ ions, giving rise to ferromagnetism at low temperature.
Optical Resolution and Circular Dichroism Spectra of Mixed-diamine Palladium(II) Complexes with Configurational Chirality
Authors: Nakayama Kazuhiko , Komorita Takashi , Shimura Yoichi 
Published: July 2006

Abstract
Six square-planar complexes, [PdL(meso-stien)](ClO4)2 (meso-stien=meso-1,2-diphenyl-1,2-ethanediamine; L=N,N-diethylethylenediamine, N,N-dimethylethylenediamine, 2-methyl-1,2-propanediamine, N2,N2-dimethyl-2-methyl-1,2-propanediamine, N, N-dimethyl-1,3-propanediamine, and (2S)-N1,N1diethyl-1,2-propanediamine), were prepared and optically resolved (or separated in the case of the last named ligand) using diacetyl-d-tartaric anhydride as the resolving agent. Their electronic absorption and CD spectra were measured. A definite additivity has been confirmed between the configurational CD caused by the chiral configuration and the vicinal CD due to the asymmetric carbon atom in the (2S)-N1,N1-diethyl-1,2-propanediamine complex. Absolute configurations of this and the other five complexes have been assigned by examining molecular models and the CD spectra.
Binuclear Metal Complexes. XXXVII. Crystal and Molecular Structure of a Binuclear Manganese(III) Complex Bridged by Two Alkoxo Oxygens and Two Bidentate Acetate Ions
Authors: Mikuriya Masahiro , Torihara Naoyuki , Okawa Hisashi , Kida Sigeo 
Published: July 2006

Abstract
The crystal structure of binuclear manganese(III) complex, Mn(spa)(ac) (H2spa=3-salicylideneamino-1-propanol, ac=acetate), was determined by the single-crystal X-ray diffraction method. The crystals are triclinic, space group P\bar1, a=8.804(3), b=9.376(3), c=8.671(3) Å, α=111.24(3), β=101.34(3), γ=65.00(3)°, and Z=1. The structure was solved by the heavy atom method and refined by the block-diagonal least-squares method to an R factor of 0.034. The crystal structure consists of discrete binuclear clusters, where the two manganese atoms are bridged by two alkoxo oxygens of the spa ligands and two bidentate acetate ions. The structural detail is in conformity with the magnetic and spectral properties previously reported.
X-Ray Structures of Cu(II) Chelates of cis-1,3-Cyclohexanediamine
Authors: Kamisawa Keiko , Matsumoto Keiji , Ooi Shun’ichiro , Saito Reiko , Kidani Yoshinori 
Published: July 2006

Abstract
The crystal structures of wine-red [Cu(1,3-chxn)2]Br2 (1), [Cu(1,3-chxn)2](NO3)2 (2), and blue-violet [CuCl(1,3-chxn)2]ClO4 (3) (1,3-chxn=cis-1,3-cyclohexanediamine) have been determined from the diffractometer data measured by the use of Mo Kα radiation. The structures were solved by the Patterson–Fourier method and refined by the least-squares method to R=0.042 (1), 0.033 (2), and 0.057 (3) for 1309, 1210, and 776 nonzero reflections respectively. The Cu atoms in 1 and 2 have a square-planar coordination by 4 N atoms, while the complex ion in 3 has a 5-coordinate square-pyramidal geometry, with the Cl atom at the apical position. The 6-membered chelate rings in 1, 2, and 3 are of the chair, flattened-chair, and envelope conformations respectively. The complex ions in 1 and 2 have virtually a C2h symmetry, the two-fold axis of which lies on the CuN4 plane. The virtual symmetry for [CuCl(1,3-chxn)2]+ is C2v, the approximate two-fold axis being coincident with the Cu–Cl bond. The cyclohexane rings (chair conformation) in 2 and 3 are roughly perpendicular to the coordination plane, but that in 1 leans toward the central Cu(II) atom. The formation of such coordinatively unsaturated Cu(II) complexes as 1–3 is attributable to the steric hindrance of the bulky cyclohexane ring to the axial coordination site.
Reaction Paths of the Photochemical Electrocyclic Reaction of Acrylaldehyde. A Possible Path via a Zwitterion
Authors: Kikuchi Osamu , Kubota Hiroshi , Suzuki Keizo 
Published: July 2006

Abstract
The photochemical electrocyclic reaction paths of s-cis-acrylaldehyde to oxetene were examined on the basis of the potential surfaces obtained by the MINDO/3 CI calculation, and compared with those of the corresponding conjugated hydrocarbon system. The strong S0-S2 interaction, which appears in the disrotatory mode of the cyclization of butadiene, was not observed in the acrylaldehyde–oxetene system. There appears to be a step-by-step path, in which the π→π* induced rotation of the methylene group is followed by the ring-closing step. The zwitterion in which the positive charge is localized on the terminal carbon atom is involved in this step. Since the σ lone-pair electrons of the oxygen atom play a key role in the ring-closing step, this path is characteristic of the hetero-atom conjugated system and cannot be deduced by analogy or by a simple extension of the concepts established for the photoreactions of all-hydrocarbon conjugated systems. The possible decay paths from acrylaldehyde in the excited states were also discussed.
Dehydrooligopeptides. II. The Synthesis of Dehydrodehydrodipeptides by Direct Coupling and Base-catalyzed β-Elimination
Authors: Shin Chung-gi , Yonezawa Yasuchika , Takahashi Masatoshi , Yoshimura Juji 
Published: July 2006

Abstract
The direct coupling between N-protected α-dehydroamino acid (1) and N-free α-dehydroamino acid ester (2) by the acid-chloride method was carried out to give several dehydrodehydrodipeptides (7). Furthermore, the two kinds of dehydrodipeptides with a hydroxyl group, obtained by the coupling of 1 with a serine or threonine ester, and that of N-protected serine or threonine with 2, followed by mesylation and subsequent base-catalyzed β-elimination gave a number of 7 substances in good yields. The configurational structures of 7 obtained by both direct condensation and elimination were found to have (Z,Z)-geometry.
The Preparation of Optically Active β-Keto Sulfoxides by Means of an Enantiomer-differentiating Reaction of α-Lithio Aryl Methyl Sulfoxides with Chiral Carboxylates
Authors: Kunieda Norio , Suzuki Akira , Kinoshita Masayoshi 
Published: July 2006

Abstract
The reaction of α-lithio aryl methyl sulfoxides with a limited amount of chiral carboxylates (R2–CO–O–R*) was found to be an enantiomer-differentiating reaction, affording the corresponding optically active β-keto sulfoxides (3), together with optically active aryl methyl sulfoxides which have the opposite configuration. The optical purity and the predominant configuration of 3 obtained were assigned by means of a combination of polarimetric analysis and NMR. The degree of enantioselectivity of this reaction was affected by the nature of the ester moiety R2, indicating an increase in optical yields, from 1.3%, where R2 was ethyl (3b), to 70.3%, where R2 was t-butyl (3f). The stereochemical course of the reaction has been discussed by considering a six-membered cyclic transition state. Furthermore, the repeated recrystallizations of several β-keto sulfoxides thus obtained, such as (−)-3e, (−)-3f, (−)-3g, and (−)-3p, were found to give the corresponding highly optically pure β-keto sulfoxides.
Crystal Structure and Absolute Configuration of (−)589-Tris(2,2′-bipyridinecobalt(III) Hexacyanoferrate(III) Octahydrate
Authors: Yanagi Kazunori , Ohashi Yuji , Sasada Yoshio , Kaizu Youkoh , Kobayashi Hiroshi 
Published: July 2006

Abstract
The crystal structure and absolute configuration of the title compound, (−)589-[Co(bpy)3][Fe(CN)6]·8H2O, has been determined from single-crystal X-ray data. The yellow crystals are triclinic; unit-cell dimensions a=12.174(3), b=16.742(7), c=10.651(3) Å, α=103.25(3), β=104.09(2), γ=94.71(3)°, space group Pl, Z=2. The structure was solved by the heavy-atom method and refined to R=0.076. The (−)589-isomer of [Co(bpy)3]3+ has Δ configuration. The [Co(bpy)3]3+ and [Fe(CN)6]3− ions have an approximate D3 symmetry and nearly the same structure as those in other related complexes. All the N atoms in [Fe(CN)6]3− and the water molecules participate in a three-dimensional hydrogen-bond network.
The Electronic Absorption Spectra of Fatty Acid Mono-, Bi-, and Multilayers with Bivalent Metal Ions
Authors: Nagahira Yukio , Matsuki Kazunori , Fukutome Hideo 
Published: July 2006

Abstract
The electronic absorption spectra of fatty acid multilayers with bivalent metal ions were studied in the vacuum ultraviolet (VUV) to ultraviolet (UV) energy region below 8 eV; they are due to transitions in the carboxylic acid and metal carboxylate moieties. Infrared (IR) absorptions due to the C–O stretching vibration in the carboxylate moiety are also studied. Stearic acid multilayers without metal ions are shown to form hydrogen-bonded dimers. The spectra of multilayers with metal ions show a marked dependence on the subphase pH which is different for different kinds of adsorbed metal ions. Their VUV spectra are conspicuously dependent on the kind of metal ions adsorbed. All the multilayers with alkaline earth metals, metals of the 2B group, transition metals, Cu, and Pb have at least two bands in the VUV region, 7.3–6.3 eV. The polarization spectra of the Ba stearate multilayer suggest that the two transitions may be the intramolecular π-π* and n-π* transitions in the carboxylate anion moiety. The multilayers with Cu and Pb have another band in the UV region. The spectra of the UV bands of the Pb and Cu stearate mono-, bi-, and multilayers were studied. In the Pb stearate layers, the positions of the UV bands in the bi- and multilayers are the same, but those in the monolayers are at considerably shorter wavelengths. The positions of the UV band in the Cu stearate mono-, bi-, and multilayers are successively red shifted. The polarization spectra of the UV bands of the mono- and bilayers showed that they are charge-transfer bands between the Pb or Cu ion and the coordinated carboxylate moiety.
The Synthesis of Potassium Pentacyanohydroxochromate(III)
Authors: Sakabe Yuzuru , Matsumoto Yoshio 
Published: July 2006

Abstract
The crystals of K3[Cr(CN)5(OH)]·H2O have been obtained by making [CrCl(NH3)5]Cl2 react with KCN, followed by purification on a Sephadex gel column.
Ammonolysis of N-Acylpyroglutamic Acid. Permanganateoxidation of Peptides. II.
Authors: Torigoe Keisuke , Motoki Yoshiaki , Muramatsu Ichiro 
Published: July 2006

Abstract
The reaction of N-acylpyroglutamic acid with ammonia proceeds in two pathways. The one results in N-acylglutamine as a product, and the other in pyroglutamic acid and an amide formed from the N-acyl group. The ratio of the yields of the two reactions changes with the N-acyl group, being correlated with the acidity of the carboxylic acid from which the N-acyl group is derived, and also with the steric hindrance of the group.
A Simple Method for the Esterification of Carboxylic Acids Using Chlorosilanes
Authors: Nakao Ren , Oka Kunio , Fukumoto Tsugio 
Published: July 2006

Abstract
Various carboxylic esters, including some with bulky substituents, are prepared in good yields from carboxylic acids and alcohols under mild conditions by the use of trimethylchlorosilane, dimethyldichlorosilane, methyltrichlorosilane, or tetrachlorosilane.
Carbon-13 Chemical Shifts of Polychlorobicyclo[2.2.1]heptene Derivatives
Authors: Sera Akira , Takagi Kazuhiro , Nakamura Michiko , Seguchi Kazuyoshi 
Published: July 2006

Abstract
The 13C chemical shifts of 5-substituted polychlorobicyclo[2.2.1]heptene derivatives were determined. The chlorine, 5-endo and 5-exo substituent effects on the chemical shifts were discussed. The differences in the C3and C7 chemical shifts are shown to be helpful for the identification of the endo and exo isomers. A possible operation of the interaction of pi electrons with a carbon-chlorine dipole is also discussed.
Studies on Heterocyclic Analogs of Azulene. VIII. Reaction of 2-Alkoxycyclohepta[6]pyrroles with Dimethyl Acetylenedicarboxylate
Authors: Abe Noritaka , Nishiwaki Tarozaemon 
Published: July 2006

Abstract
2-Alkoxycyclohepta[b] pyrroles reacted with dimethyl acetylenedicarboxylate to give tetramethyl 2-alkoxy-3H-2a-azacyclopenta[ef]heptalene-3,4,5,6-tetracarboxylates in benzene and dialkyl 2-(2-alkoxycyclohepta[b]pyrrol-1-yl)fumarate in alcoholic solvents.
Ketone Synthesis from Acid Chloride by Means of Organometallic Reagent Derived from R3Al–Cu(acac)2-PPh3 System
Authors: Takai Kazuhiko , Oshima Koichiro , Nozaki Hitosi 
Published: July 2006

Abstract
Reaction of acid chlorides or thiocarboxylic S-esters with the title reagent in tetrahydrofuran provides ketones in good to excellent yields. The coupling reactions with ally lie halides to form alkene derivatives are also disclosed.