bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Gastric Bypass and Gastric Banding on Proneurotensin Levels in Morbidly Obese Patients
Authors: Christ-Crain Mirjam , Stoeckli Rolf , Ernst Andrea , Morgenthaler Nils G. , Bilz Stefan , Korbonits Márta , Struck Joachim , Bergmann Andreas , Müller Beat , Keller Ulrich 
Published: June 2006

Abstract
Context: Neurotensin is produced mainly in the N cells of the ileum and has a role in appetite regulation; levels are decreased in obese subjects and increase after bariatric surgery. Mature neurotensin is very unstable, with a short half-life.
Objective: The objective of this study was to compare baseline and postoperative levels of the more stable neurotensin precursor, proneurotensin/neuromedin (pro-NT/NMN), in patients after gastric banding, gastric bypass, and nonoperated controls, respectively, during long-term follow-up.
Design and Setting: This was a prospective observational study in a university hospital.
Participants and Main Outcome Measures: Overnight fasting plasma pro-NT/NMN concentrations were measured with a new sandwich immunoassay in morbidly obese subjects at baseline and 6, 12, and 24 months after gastric banding (n = 8), Roux-en-Y gastric bypass (n = 5), and in nonoperated controls (n = 7).
Results: After gastric bypass and banding, body weight decreased by (mean ± sd) 29.5 ± 5.5 and 22.8 ± 5.9 kg, respectively. The decrease after 3 and 6 months was more pronounced after gastric bypass compared with gastric banding (P &lt; 0.05). Plasma pro-NT/NMN levels in patients after gastric bypass increased from 246.3 ± 174.3 pmol/liter on admission to 748.3 ± 429.6 pmol/liter after 24 months (P &lt; 0.01). In contrast, in patients with gastric banding, pro-NT/NMN concentrations remained stable (207.3 ± 60.5 pmol/liter at admission, 226.6 ± 116.8 pmol/liter after 24 months). Neither body weight nor plasma pro-NT/NMN levels changed in nonoperated controls.
Conclusion: Plasma pro-NT/NMN levels show a more pronounced increase after gastric bypass compared with gastric banding, suggesting that specific bariatric surgical procedures result in distinct alterations of gastrointestinal hormone metabolism. The more stable precursor pro-NT/NMN provides a new tool to quantify neurotensin levels in clinical practice.
Molecular Model of Human CYP21 Based on Mammalian CYP2C5: Structural Features Correlate with Clinical Severity of Mutations Causing Congenital Adrenal Hyperplasia
Authors: Robins Tiina , Carlsson Jonas , Sunnerhagen Maria , Wedell Anna , Persson Bengt 
Published: June 2006

AbstractEnhanced understanding of structure-function relationships of human 21-hydroxylase, CYP21, is required to better understand the molecular causes of congenital adrenal hyperplasia. To this end, a structural model of human CYP21 was calculated based on the crystal structure of rabbit CYP2C5. All but two known allelic variants of missense type, a total of 60 disease-causing mutations and six normal variants, were analyzed using this model. A structural explanation for the corresponding phenotype was found for all but two mutants for which available clinical data are also discrepant with in vitro enzyme activity. Calculations of protein stability of modeled mutants were found to correlate inversely with the corresponding clinical severity. Putative structurally important residues were identified to be involved in heme and substrate binding, redox partner interaction, and enzyme catalysis using docking calculations and analysis of structurally determined homologous cytochrome P450s (CYPs). Functional and structural consequences of seven novel mutations, V139E, C147R, R233G, T295N, L308F, R366C, and M473I, detected in Scandinavian patients with suspected congenital adrenal hyperplasia of different severity, were predicted using molecular modeling. Structural features deduced from the models are in good correlation with clinical severity of CYP21 mutants, which shows the applicability of a modeling approach in assessment of new CYP21 mutations.
Pharmacological characterization of the ergot alkaloid receptor in the salivary gland of the ixodid tickAmblyomma hebraeum
Authors: Kaufman W. Reuben , Minion Jessi L. 
Published: June 2006

SUMMARYFemale ticks of the family Ixodidae osmoregulate by secreting the excess fluid of the blood meal back into the host's circulation via the salivary glands. At least three receptors control salivary fluid secretion in the tick Amblyomma hebraeum: (1) dopamine (DA) stimulates fluid secretion via a DA receptor, (2) ergot alkaloids (ErAs) stimulate fluid secretion via an ErA-sensitive receptor (the natural ligand of which has not been identified), and (3) a GABA receptor potentiates the action of DA and ErAs. Here we present some pharmacological properties of the ErA-sensitive receptor. Of the 11 ErAs we tested, (i) four were complete agonists (approximate concentration eliciting 50% maximum response is given in parentheses): dihydroergotamine (0.02 μmol l–1),ergonovine (ErN; 0.06 μmol l–1), methylergonovine (0.1μmol l–1) and α-ergocriptine (0.9 μmol l–1); (ii) three were `incomplete agonists' (approximate concentration eliciting 20% maximum response is given in parentheses):ergocorninine (3.5 μmol l–1), ergocristinine (7.5 μmol l–1) and ergocristine (10 μmol l–1); (C)three were partial agonists (approximate concentration eliciting the respective maximum response in parentheses): ergocornine (50% maximum by 1μmol l–1), methysergide (28% maximum by 10 μmol l–1) and bromocriptine (22% maximum by 10 μmol l–1); and (D) one had no activity up to 1 mmol l–1: ergothioneine. Bromocriptine and methysergide did not antagonize the action of DA, but were effective competitive antagonists of ErN, with Kis of ∼0.3 μmol l–1 and 11 μmol l–1, respectively. Ergothioneine was not an antagonist at either the DA- or ErA-sensitive receptor. The putative protein kinase C activators, 1-oleoyl-2-acetyl-sn-glycerol (OAG) and 1,2-dioctanoyl-sn-glycerol (DiC8), neither stimulated salivary fluid secretion nor potentiated the action of DA or ErN. The putative protein kinase C inhibitors, bisindolymaleimide (BIM) and calphostin C did not inhibit the action of DA or ErN, although low concentrations of calphostin C(10 nmol l–1) appeared to potentiate the action of DA but not ErN. The ion transport inhibitors, furosemide and amiloride (both up to 1 mmol l–1), had no significant effect on DA-stimulated or ErN-stimulated fluid secretion.
Water vapour absorption in the penicillate millipedePolyxenus lagurus(Diplopoda: Penicillata: Polyxenida): microcalorimetric analysis of uptake kinetics
Authors: Wright Jonathan C. , Westh Peter 
Published: June 2006

SUMMARYThe aberrant millipedes of the order Polyxenida are minute animals that inhabit xeric microclimates of bark and rock faces. The lichens and algae that provide their main food substrates tolerate extensive dehydration, effectively eliminating a liquid water source during periods of drought. In this study, we used microcalorimetry to test whether Polyxenus lagurus (L.) exploits active water vapour absorption (WVA) for water replenishment. Individual animals were pre-desiccated to 10–20% mass-loss and heat fluxes then monitored using a TAM 2277 microcalorimeter. The calorimetric cell was exposed to an air stream increasing progressively in humidity from 84% to 96%. WVA was distinguishable as large exothermic fluxes seen in ≥86% RH. Owing to very small and opposing heat fluxes from metabolism and passive water loss, the measured flux provided a good measure of water uptake. WVA showed an uptake threshold of 85% RH and linear sorption kinetics until &gt;94% RH, when uptake became asymptotic. Uptake was rapid, and would allow recovery from 20%dehydration (by mass) in little over 5 h. The uptake flux scales ∝mass0.61, suggesting an area-limited mechanism. Polyxenuspossesses a cryptonephric system, analogous to that of tenebrionid beetle larvae. Measurements of water absorption and desorption from faecal pellets voided in different humidities gave an estimated rectal humidity of 85.5%. The close congruence between this value and the WVA threshold provides evidence for a cryptonephric uptake mechanism derived independently from that of tenebrionids. Polyxenus represents the first documented example of WVA in the myriapod classes.
Polyorganosilicon Compounds in Strained Carbocyclic Systems
Authors: Ando Wataru 
Published: June 2006

Abstract
Organosilicon chemistry has been highlighted by the successful construction and thorough characterization of strain carbocyclic systems: 1) silabenzene, silafulvene, and polycyclic polysilane via a silylcarbene rearrangement to silene, 2) a ring-expansion reaction of disilacyclobutene with exo-methylene, and 3) cyclic polysilanes containing unsaturated carbon systems, such as acetylene, allene, and fullerene. Some of these numerous compounds, which are now available, are fully substituted with bulky ligands. These compounds permit examinations of: 1) the variation in the physical and chemical properties of a system with polysilane, and 2) how the systems are related thermally and photochemically with carbon analogues. Some cyclic polysilanes may constitute a stepping stone on the way to super-molecules.
Selective Adsorption of Lipopolysaccharide from Protein Solutions by Porous Supports Bearing Cationic Lipid Membranes
Authors: Wakita Masa-aki , Adachi Tsuneyasu , Ida Jun-ichi , Hashimoto Masanori 
Published: June 2006

Abstract
Cationic lipid membranes of N-octadecylchitosan consisting of 2-deoxy-2-octadecylamino-d-glucopyranose, 2-amino-2-deoxy-d-glucopyranose, and 2-acetamido-2-deoxy-d-glucopyranose were covalently immobilized to carboxylated porous supports and used for the adsorption of pyrogenic lipopolysaccharide (LPS). When bovine serum albumin (BSA) solution, including 5 mg mL−1 of BSA and 100—148 ng mL−1 of LPS, was passed through a column packed with the porous supports bearing the cationic lipid membranes, LPS was selectively adsorbed and removed to as low as 0.1 ng mL−1 with quantitative recovery of BSA. LPS seemed to be dissociated from molecular complexes with BSA, and adsorbed selectively to the cationic lipid membranes by both an ionic interaction and a hydrophobic one.
Syntheses of Highly Ordered Mesoporous Materials, FSM-16, Derived from Kanemite
Authors: Inagaki Shinji , Koiwai Akihiko , Suzuki Noritomo , Fukushima Yoshiaki , Kuroda Kazuyuki 
Published: June 2006

Abstract
The synthetic conditions of highly ordered and thermally stable mesoporous molecular sieves from a layered silicate kanemite are established. We divided the formation process of the mesoporous materials from kanemite into two elemental processes: i) exchange of Na+ in the interlayer of kanemite for alkyltrimethylammonium cations and ii) condensation of silicates and formation of a three dimensional silicate framework. Higher pH (over 11.5) at the cation-exchange process and the subsequent pH adjustment at 8.5 at the condensation process were best suited for the formation of mesoporous products with high regularity and thermal stability. Removal of partially dissolved kanemite during the cation-exchange process avoided the formation of amorphous materials as a by-product. Structures of some intermediate silicate/surfactant complexes supported the proposed folded sheets mechanism for the formation of the mesoporous molecular sieves. Syntheses by using alkyltrimethylammonium with different alkyl-chain lengths are also reported.
Inter-Peptide Hydrogen Bonding in Monolayers of Oligoglycine Amphiphiles
Authors: Cha Xiao , Ariga Katsuhiko , Kunitake Toyoki 
Published: June 2006

Abstract
N-Octadecanoyl oligoglycine (monomer to pentamer) ethyl esters were synthesized. The structures of their monolayers and LB films transferred from pure water were investigated by π–A isotherms and FT-IR reflection absorption spectroscopy (FT-IR, RAS). All the glycine residues were involved in intermolecular hydrogen bonding as indicated by shifts of the NH stretching band and other IR features. The strength of the hydrogen bonds was increased with increasing numbers of the glycine residues in a molecule. The FT-IR characteristics of these monolayers are close to those of polyglycine II, despite the fact that these oligopeptides are not long enough for conformational fixation in bulk water.
Reversible Electrochromism of Copper Phthalocyanine Thin Film
Authors: Toshima Naoki , Tominaga Tsuyoshi , Kawamura Shin-ichi 
Published: June 2006

Abstract
The electrochromism of copper phthalocyanine thin films was examined in detail under various conditions. The application of a positive voltage to copper phthalocyanine thin film exhibited two oxidation peaks in the range from 0 to 1.4 V. Although the color of the film changed from sky blue to pale gray upon scanning the voltage in this region, irreversible electrochromism was observed, leading to a deterioration of the film. The two oxidation peaks were concluded to represent two types of appearances of one reaction with different overpotentials caused by the structure of the crystal grains of the film. Control of the scan range to admit only the first oxidation peak provided a reversible electrochromism between sky blue and bluish purple. Electrolyte anions are also of great importance to accomplish reversible electrochromism. Thus, the anions should be stable for the application of a positive voltage, and their Stokes radii should be neither too large nor too small in order to achieve reversible electrochromism. Rather small anions provide almost Nernstian cyclic voltammograms and the quick color change.
Study of the Electronic Structure of GaAs(100) Single Crystal Electrode/Electrolyte Interfaces by Electrochemical Tunneling Spectroscopy
Authors: Uosaki Kohei , Ye Shen , Sekine Namiki 
Published: June 2006

Abstract
An electrochemical tunneling spectroscopy (ETS) system is constructed to study the electronic structure of semiconductor/electrolyte interfaces. By using this system, the tunneling current of GaAs (100) single crystal electrodes in solution was measured as a function of electrode potential at a constant sample-tip distance. Tunneling current flowed in the forward bias region; the current depended on the bias, i.e., the potential with respect to the flat band potential. It decreased by decreasing the bias and became zero near the flat band potential. This behavior can be explained by considering the potential dependence of the surface concentration of the majority carriers. The space charge layer within the semiconductor formed in the reverse bias region worked as an extra barrier for the tunneling process; therefore, no tunneling current was observed in this potential region. Current in the direction opposite to that in the forward bias region flowed as the reverse bias became very large, although this current was very small. In this potential region, the thickness of the space charge layer near the Fermi level of the tip became thinner and electrons were able to tunnel through the barrier. Effects of the doping density, the tip potential, the pre-set tunneling current and the initial sample potential as well as the surface treatment on the tunneling current–electrode potential relation were investigated in detail at n-GaAs(100) single crystal electrodes. The tunneling behaviors in the forward and reverse bias regions were discussed semi-quantitatively based on the calculation of surface electron concentration and the transmission coefficient through the space charge barrier, respectively.
Reactions of Si–Si σ-Bonds with Bis(t-alkyl isocyanide)palladium(0) Complexes. Synthesis and Reactions of Cyclic Bis(organosilyl)palladium Complexes
Authors: Suginome Michinori , Oike Hideaki , Park Sang-Soo , Ito Yoshihiko 
Published: June 2006

Abstract
Four- to seven-membered cyclic bis(organosilyl)palladium(II) complexes were synthesized by oxidative addition of cyclic disilanes onto bis(t-butyl isocyanide)palladium(0) as well as by intramolecular metathesis of the two Si–Si bonds of bis(disilane)s with the palladium(0) complex. The 4-membered bis(organosilyl)bis(t-butyl isocyanide)palladium complex prepared from 2,2-bis(1,1,2,2-tetramethyl-2-phenyldisilanyl)-1,3-dithiane was characterized by a single-crystal X-ray method, which showed an unusually short cross-ring Si–Si distance in the 4-membered ring. The reactivities of the cyclic bis(organosilyl)bis(t-butyl isocyanide)palladium complexes toward phosphines, cyclic disilanes, and alkynes were also examined. Cyclic organosilicon compounds were synthesized by bis-silylation of alkynes with cyclic bis(organosilyl)palladium intermediates generated by the intramolecular metathesis. The bis-silylation was also applicable for electron-deficient alkenes: α,β-unsaturated ketones gave 7-membered 1,4-bis-silylation adducts, whereas the corresponding ester and nitrile gave 5-membered 1,2-adducts in high yields.
Thermal Decomposition and Mass Spectra of the N-Phenyl-, N,N′-Diphenyl-, and N,N′,N″-Triphenylphosphoric Triamides
Authors: Fukushima Kazuhiko , Kanayama Atsushi , Matsumoto Yoshihiro , Ono Shin , Yoshimura Toshiaki , Morita Hiroyuki , Tsukurimichi Eiichi , Shimasaki Choichiro 
Published: June 2006

Abstract
The thermal decomposition and mass spectra of the N-phenyl- (1), N,N′-diphenyl- (2), and N,N′,N′-triphenylphosphoric triamides (3) were investigated. DTA-TG/DTG, TG-TRAP-GC/MS measurements, IR spectroscopic analyses, mass spectrometric analyses, HPLC analyses, and a kinetic study were carried out to investigate the thermal decomposition. From the analytical results, it was suggested that 1 decomposed while liberating ammonia and aniline, and condensed in several stages; its thermal products at about 160 °C contained 2. Compound 2 decomposed and condensed to form some condensed products at about 200 °C; its thermal products also contained 3. Compound 3 decomposed while liberating aniline to form a cyclic dimer, while the existence of other thermal products was also observed; the cyclic dimer further pyrolyzed in several stages, and 1 and 2 formed a similar condensed product in the 400 to 500 °C temperature range, though that for 3 was different. In addition, the apparent activation energy of the thermal decomposition was estimated and the thermal decomposition process was investigated based on this variation. In the mass spectra using electron impact, 1, 2, and 3 were cleaved along with an elimination of ammonia and/or aniline to form a three-coordinate phosphenimidic amide.
Rearrangement of Bicyclo[2.2.2]octa-2,5-diene and Bicyclo[3.2.2]nona-6,8-diene under the Conditions of Bromination
Authors: Satake Kyosuke , Hikasa Kazuyuki , Itoh Hajime , Okamoto Hideki , Kimura Masaru , Morosawa Shiro 
Published: June 2006

Abstract
A reaction of electrophilic bromination of norbornadiene homologs such as bicyclo[2.2.2]octa-2,5-diene (4) and bicyclo[3.2.2]nona-6,8-diene (7) with bromine gave hitherto unknown skeleton rearranged dibromides. The rearrangement may proceed via a bromonium cation of starting diene to give bicyclo[3.2.1]octene or bicyclo[3.3.1]nonene skeleton in respective cases. The observed rearrangement reactions are also confirmed in 6,7-bis(methoxycarbonyl) derivatives of bicyclodiene 7 under similar conditions.
Diethyl Ether–Boron Trifluoride (1/1) Induced Transannular Cyclization Reaction of Humulene 2,3-Epoxide
Authors: Hayano Kiyoharu , Shirahama Haruhisa 
Published: June 2006

Abstract
The treatment of (6E, 9E)-2,3-epoxy-3,7,11,11-tetramethylcycloundeca-6,9-diene with Et2O·BF3 produced four novel transannular cyclized compounds of (4E)-(1S*, 8S*, 9S*)-8-acetoxy-6,6,9-trimethyl-2-methylenebicyclo[7.2.0]undec-4-ene (13), (2Z, 4E)-(1S*, 8S*, 9S*)-8-acetoxy-2,6,6,9-tetramethylbicyclo[7.2.0]undeca-2,4-diene (14), (6E)-(1R*, 2R*, 3S*, 10R*)-3-acetoxy-2,5,5-trimethyl-9-methylenebicyclo[8.1.0]undec-6-ene (15), and (4E)-(1S*, 2S*, 8S*, 9S*)-2,8-diacetoxy-2,6,6,9-tetramethylbicyclo[7.2.0]undec-4-ene (16) together with three new acetates: (2E, 5E, 8E)-1-acetoxy-2,6,10,10-tetramethylcycloundeca-2,5,8-triene, (1E, 6E)-3,9-diacetoxy-2,5,5,9-tetramethylcycloundeca-1,6-diene, and (4E, 7E)-1-acetoxy-3,3,7-trimethyl-11-methylenecycloundeca-4,7-diene. The configurations of the bicyclo[7.2.0]undecane skeletons (13, 14, and 16) and 15 maintained the shape of TC and CT conformers of the original epoxide, respectively.
Effects of Solvent Fluctuations on the Rate of Thermal Z/E Isomerization of Azobenzenes and N-Benzylideneanilines
Authors: Asano Tsutomu , Cosstick Kevin , Furuta Hiroyuki , Matsuo Kohei , Sumi Hitoshi 
Published: June 2006

Abstract
Effects of pressure on thermal Z/E isomerization of substituted N-benzylideneanilines and azobenzenes were studied in 2-methyl-2,4-pentanediol. Pressure dependence of the Z/E isomerization of a substituted azonaphthalene was also studied in glycerol triacetate. From the results in this and earlier papers, the following conclusions were reached. 1) It is possible to cast slow thermal reactions into the state of fluctuation control in highly viscous liquid phase realized by a combination of a viscous liquid and high pressure. 2) The viscosity dependence of the rate constant can be rationalized by the two-dimensional reaction-coordinate model developed by Sumi but not by the Grote–Hynes’ theory of frequency-dependent friction. Namely, the energy-barrier crossing takes place after the solvent molecules are rearranged to accommodate the transition state. 3) Whether the solvent rearrangement involves chemical transformations with appreciable energy increases depends on the nature of the reaction and the solvent.
Isomer Compositions of Trimethyl- or Trichlorobenzenes in α-Cyclodextrin Precipitates Formed in an Aqueous Medium
Authors: Sanemasa Isao , Wu Yue , Sato Takayuki , Samejima Kaoru , Koide Yuuki , Takaki Noriyuki , Toda Kei , Deguchi Toshio 
Published: June 2006

Abstract
Upon introducing the vapor of binary mixtures of trimethylbenzene (TMB) or trichlorobenzene (TCB) isomers into an α-cyclodextrin (α-CyD) aqueous solution, and circulating it in a closed system, CyD was precipitated with the isomers. In (1,3,5–1,2,3 or 1,2,4,)-TMB systems of various mixing ratios, the mole fraction of 1,3,5-TMB in the total TMBs precipitated was considerably lower than that of 1,2,3- or 1,2,4-TMB: selective precipitation of 1,2,3- or 1,2,4-TMB occurred in the presence of 1,3,5-TMB. The concentration of α-CyD in the supernatant aqueous solution was determined as a function of the isomer mixing ratio. The selectivity was rather poor in the cases of TCB systems. Ternary mixtures of TMB isomers were also studied to a less extent. The solubility product constants at 25 °C were proposed for TMB and TCB precipitates with α-CyD.
Syntheses, Structures, and Molecular-Orbital Calculations of Chromium Chevrel-Type Cluster Complexes [Cr6E8(PR3)6] (E = S, PR3 = PEt3, PMe3; E = Se, PR3 = PEt3, PMe3, PMe2Ph)
Authors: Tsuge Kiyoshi , Imoto Hideo , Saito Taro 
Published: June 2006

Abstract
Hexanuclear chromium cluster complexes [Cr6E8(PR3)6] (E = S, PR3 = PEt3, PMe3; E = Se, PR3 = PEt3, PMe3, PMe2Ph) were prepared by the reaction of anhydrous chromium dichloride, a trialkylphosphine, and either NaSH or Na2Se in methanol. The complexes comprised the Cr6 octahedra with eight face-bridging chalcogen atoms and six terminal phosphine ligands. Though the overall ligand arrangements were the same, the symmetry of the central Cr6 octahedra was Oh in PEt3 complexes, but distorted to D3d and D2h in PMe3 and PMe2Ph complexes, respectively. Because of a weakness of the metal–metal interaction, the steric and electronic effect complementarily caused a variation in the chromium octahedra. The electronic effect was analyzed by molecular-orbital calculations using the DV-Xα method.