bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reaction of (COCl)2 with AgN3: Evidence for the Formation of Oxalyl Diazide O2C2(N3)2
Authors: Fengyi Liu , Xiaoqing Zeng , Qiao Sun , Lingpeng Meng , Shijun Zheng , Xicheng Ai , Jianping Zhang , Maofa Ge , Dianxun Wang 
Published: July 2005

Abstract
Oxalyl diazide O2C2(N3)2 has been generated in the heterogeneous reaction of (COCl)2 vapor with AgN3 at room temperature. Evidence for the formation of O2C2(N3)2 is based on on-line photoelectron spectroscopy (PES) characterization combined with the density functional B3LYP and outer valence Green’s function (OVGF) calculations. The good agreement between the experimental spectra and theoretical calculation shows that O2C2(N3)2 has adiabatic ionization energy of 10.11 eV. Our results also suggest that O2C2(N3)2 has high conformational flexibilities and that the planar conformers are energy-favorable in gas phase.
On Infrared Intensities of Spinel, MgAl2O4
Authors: Kanesaka Isao , Hayashi Yuichi , Morioka Yoshiyuki 
Published: July 2005

Abstract
In spinel (MgAl2O4), the strongest infrared band at 485 cm−1 shows less LO–TO splitting than the medium band at 670 cm−1. This unexpected relationship is explained in terms of the vibrational coupling of these TO modes. A new manner for evaluating the LO mode is proposed.
Growth of Hexagonal Bipyramidal Ruby Crystals by the Evaporation of a Li2O–MoO3 Flux
Authors: Teshima Katsuya , Kondo Hitoshi , Oishi Shuji 
Published: July 2005

Abstract
The growth of hexagonal bipyramidal ruby crystals by the flux evaporation method in the Li2O–MoO3 flux system has been reported. Ruby crystals were grown by heating a mixture of a solute (Al2O3 + 0.5 wt % Cr2O3) and a flux (Li2O–MoO3) at 1050, 1100, or 1200 °C, followed by holding the solution at these temperatures for 5 h. The crystal size was dependent on the evaporation loss of the flux. The evaporation loss of the flux gradually decreased with increasing amount of Li2O added to MoO3, and increased with the holding temperature. The obtained ruby crystals had lengths of up to 2.6 mm and widths of up to 2.1 mm, and had a transparent-red color. Their form was a bipyramid, bounded by well-developed faces. The most suitable flux composition for high-quality and large ruby crystal growth was found to be 2 mol % Li2O–98 mol % MoO3.
Observation of a Large Current on the Cyclic Voltammetry of Acylaminoferrocenes in the Solid State: An Efficient Electron-Transfer Pathway through Continuous NH···O=C Hydrogen-Bond Chains and π-Conjugation
Authors: Okamura Taka-aki , Sakauye Keiko , Doi Mototsugu , Yamamoto Hitoshi , Ueyama Norikazu , Nakamura Akira 
Published: July 2005

Abstract
A series of crystal structures of acylaminoferrocenes, [(C5H5)Fe(C5H4NHCOR)] (R = CH3 (1), CH2CH3 (2), t-Bu (3), and CF3 (4)) revealed an unusually delicate dependence of the alkyl substituent structure on electron transfer through NH···O=C bonding and π-conjugation. The presence of strong intermolecular NH···O=C hydrogen bonds in the crystal was established by X-ray, IR, and CRAMPS. Compounds 1 and 2 are without steric or electrostatic hindrance, and both exhibit continuous and strong hydrogen-bond chains, or an effective π-electrons system. However, the hydrogen-bond chains in 3 and 4 are weak, or broken, by the bulkiness of t-Bu or the electrostatic repulsion of CF3. Solid-state cyclic voltammograms of 1–4 have revealed the electrochemical processes, which are critically dependent on the array and the strength of the hydrogen bonds. Although both 3 and 4 show typical reversible cyclic voltammograms, 1 and 2 exhibit irreversible redox behaviors and remarkably large current values, which indicate the presence of an effective electron transfer through the continuous hydrogen-bond chains.
Infinite Chain Structure and Steep Spin Crossover of a FeIII Complex with a N3O2 Pentadentate Schiff-Base Ligand and 4-Aminopyridine
Authors: Tanimura Kyoichi , Kitashima Ryoko , Bréfuel Nicolas , Nakamura Masaaki , Matsumoto Naohide , Shova Sergiu , Tuchagues Jean-Pierre 
Published: July 2005

Abstract
A spin crossover (SC) FeIII complex, [FeIII(4-NH2py)L]BPh4, was synthesized and characterized, where 4-NH2py = 4-aminopyridine, H2L = pentadentate N3O2 Schiff-base ligand of the 2:1 condensation product of 3-methoxysalicylaldehyde and bis(3-aminopropyl)methylamine, and BPh4− = tetraphenylborate. Cryomagnetic susceptibility measurements revealed a steep spin transition between FeIII low-spin (S = 1/2) and high-spin (S = 5/2) states at T1/2 = 120 K, but showed no hysteresis. Crystal-structural analyses were performed at 293 and 90 K in order to investigate the origin of the steep spin crossover, and to determine the structures of the high-spin and low-spin states. The crystal structure consisted of a one-dimensional chain constructed by hydrogen bonds between the amino group of 4-NH2py of a molecule and the methoxy group of the adjacent molecule.
A Solvothermal Synthesis and the Structure of (NH4)2Ag6Sn3S10
Authors: BaiYin Menghe , Ye Ling , An Yonglin , Liu Xin , Jia Cuiying , Ning Guiling 
Published: July 2005

Abstract
A novel framework, (NH4)2Ag6Sn3S10, was synthesized solvothermally and characterized by single-crystal X-ray diffraction. The framework comprises silver-rich cationic layers, [Ag6SnS4]2+, pillared by [SnS3]2− zigzag chains formed by vertex-sharing SnS4 tetrahedra; NH4+ ions are located in 1D channels.
Zn(II) Complexes with Aliphatic Thiolates. (Et4N)[Zn(SAd)3] and (Et4N)2[{Zn(ScHex)2}2(μ-ScHex)2]
Authors: Matsunaga Yuki , Fujisawa Kiyoshi , Ibi Naoko , Amir Nagina , Miyashita Yoshitaro , Okamoto Ken-ichi 
Published: July 2005

Abstract
New homoleptic aliphatic thiolato complexes with Zn(II), (Et4N)[Zn(SAd)3] (1) (HSAd = 1-adamantanethiol), and (Et4N)2[{Zn(ScHex)2}2(μ-ScHex)2] (2) (HScHex = 1-cyclohexanethiol), have a novel three-coordinate geometry for monomeric 1 and a tetrahedral geometry for dimeric 2, respectively. The complexes have been fully characterized by far-IR, Raman, and UV–vis absorption spectroscopy.
Dinuclear Pt(II) and Pd(I) Complexes with Bridging PPh2 Ligands from the Reaction of PPh2H with Zero-Valent Complexes of These Metals
Authors: Tanabe Makoto , Itazaki Masumi , Kitami Osamu , Nishihara Yasushi , Osakada Kohtaro 
Published: July 2005

Abstract
Reactions of PPh2H with [M(PCy3)2] (M = Pt, Pd) produce the dinuclear complexes with bridging PPh2 ligands of these metals, [{Pt(H)(PCy3)}2(μ-PPh2)2] and [{Pd(PCy3)}2(μ-PPh2)2], respectively.
Metal Ion-Induced Hetero-Block α-Helical Coiled Coil
Authors: Kashiwada Ayumi , Nakamura Yohei , Matsuda Kiyomi 
Published: July 2005

Abstract
To construct polypeptides that undergo a hetero-block α-helical coiled coil structure change due to metal ion-induced self-assembly formation, we designed two kinds of 18-residue polypeptides, Pep3 and Pep4, each with a metal binding site. Pep3 and Pep4 were designed based on the sequence of the isoleucine zipper polypeptide forming the triple-stranded α-helical coiled coils. While Pep3 and Pep4 are too short to form a parallel triple stranded α-helical coiled coil individually, they form the hetero-block α-helical coiled coil structure, (Pep3)3–Ni2+–(Pep4)3 in the presence of the Ni2+ ions. Circular dichroism spectroscopy and size-exclusion gel-filtration chromatography analyses revealed the formation of the (Pep3)3–Mn+–(Pep4)3 hetero-block α-helical coiled coil complex.
Chemical and Genetic Study of Ligularia tongolensis, Ligularia cymbulifera, and Ligularia atroviolacea in the Hengduan Mountains of China
Authors: Hanai Ryo , Gong Xun , Tori Motoo , Kondo Satomi , Otose Kanako , Okamoto Yasuko , Nishihama Tadaaki , Murota Akihiko , Shen Yuemao , Wu Sugong , Kuroda Chiaki 
Published: July 2005

Abstract
Three Ligularia species (L. tongolensis, L. cymbulifera, and L. atroviolacea) were examined with respect to the chemical composition and nucleotide sequence. Furanoeremophilanes were found to be produced in the root of all samples of the three species collected in northwest Yunnan and southwest Sichuan. Eight furanoeremophilanes were identified, two of which were new. Most of the identified furanoeremophilanes were oxygenated at 3, 6, and 15-positions. The nucleotide sequence of the atpB-rbcL intergenic region was found to be essentially the same in the three species. These similarities imply that the three Ligularia species, all belonging to the section Corymbosae, are close to one another. The intra-specific diversity in the two widely distributed species in the Hengduan Mountains area, L. tongolensis and L. cymbulifera, were in contrast. Four out of 19 L. tongolensis samples contained a strongly Ehrlich-positive compound besides a number of positive compounds, and five variants of the atpB-rbcL sequence were found in these samples. In contrast, no variation was observed in 13 L. cymbulifera samples with respect to the furanoeremophilane composition or the atpB-rbcL sequence. The lack of diversity in L. cymbulifera probably resulted from the uniformity of its habitat.
Highly Stereoselective Samarium(II) Iodide-Mediated Aldol Reactions of Acylaziridines with Aldehydes
Authors: Ogawa Yasuyuki , Kuroda Kiichi , Mukaiyama Teruaki 
Published: July 2005

Abstract
The samarium(II) iodide-mediated stereoselective aldol reactions of acylaziridines with aldehydes are described. β-Amino–β′-hydroxy ketones were synthesized in high yields by the aldol reaction of aldehydes with samarium enolates generated by aziridine-fragmentation of aziridinyl ketones with two moles of samarium(II) iodide. By the choice of an appropriate nitrogen protecting group, depending on the substituent at C-3 position of aziridinyl ketone, anti,anti-β-amino–β′-hydroxy ketones were diastereoselectively obtained among the four possible diastereomers. Further, enantiomerically pure anti,anti-β-amino–β′-hydroxy ketones were successfully obtained by this aldol reaction when chiral aziridinyl ketones were used. In addition, δ-amino–β′-hydroxy–β,γ-unsaturated esters were also synthesized in high yields by the aldol reaction of aldehydes with samarium enolates generated by aziridine-fragmentation and olefin-migration of γ,δ-aziridinyl–α,β-unsaturated esters using two moles of samarium(II) iodide. This aldol reaction proceeded with complete α-regioselectivity and formed (E)-olefin selectively. By introducing chiral oxazolidin-2-one auxiliary to γ,δ-aziridinyl–α,β-unsaturated carbonyl system, this reaction was extended successfully to the asymmetric reaction and enantiomerically pure syn-δ-amino–β′-hydroxy-β,γ-unsaturated esters were obtained in high yields.
Conformation Dependence of Photophysical Properties of σ–π Conjugation as Demonstrated by cis- and trans-1,2-Diaryl-1,2-disilacyclohexane Cyclic Systems
Authors: Tsuji Hayato , Shibano Yuki , Takahashi Tohru , Kumada Makoto , Tamao Kohei 
Published: July 2005

Abstract
Several configurationally constrained cis- and trans-1,2-diaryl-1,2-dimethyl-1,2-disilacyclohexanes (3a–e) have been synthesized in order to measure their photophysical properties, such as UV absorption, magnetic circular dichroism (MCD), and photoluminescence. As has been well established, the UV absorption maximum (1La band) occurs at 230–270 nm, due to the effective σ–π conjugation between the aryl groups and the disilane moiety. The absorption maximum wavelength of the trans isomer is slightly longer than that of the cis isomer for all the diaryldisilanes employed in the present study. Although the MCD spectra of the cis- and trans-1,2-diphenyl-1,2-dimethyl-1,2-disilacyclohexanes (3a) show only a slight configuration dependence, this method is helpful to detect a weak 1Lb band. The disilanes 3a and 5a show a charge-transfer (CT) emission band. The quantum yields are dependent on the disilane configuration and the solvent polarity; the order of the quantum yield is cis-3a &lt; 5a &lt; trans-3a in 3-methylpentane, while the order is 5a &lt; cis-3a &lt; trans-3a in acetonitrile. These results demonstrate that the conformation constraint is effective for controlling the photophysical properties of the diaryldisilanes.
Isolation of Two 13-epi-Neoverrucosane-Type Diterpenoids from a Marine Sponge Axinyssa tethyoides
Authors: Shimogawa Hiroki , Teruya Toshiaki , Suenaga Kiyotake , Kigoshi Hideo 
Published: July 2005

Abstract
New 13-epi-neoverrucosane-type diterpenes 1 and 2 were isolated from the marine sponge Axinyssa tethyoides. Their structures were elucidated by 2D-NMR spectroscopy, the modified Mosher’s method, and fluorescent X-ray analysis. 1 and 2 are the first 13-epi-neoverrucosane-type diterpenes that possess a sulfate group.
Multivariate Analysis and Experimental Design in the Screening of Combinatorial Libraries of Molecular Imprinted Polymers
Authors: Navarro Villoslada Fernando , Takeuchi Toshifumi 
Published: July 2005

Abstract
The combination of an experimental design/multivariate analysis method and a high-throughput technique was developed in the screening and evaluation of molecular imprinted polymers (MIPs). Combinatorial libraries of MIPs were prepared automatically at a reduced scale and screened for high affinity with regard to six experimental factors with a large impact in the MIP synthesis: the amounts of the functional monomer, cross-linker and template; the volume of the porogen, the amount of the initiator and the types of initiation. With the objective of optimizing a polymer imprinted with the non-steroidal anti-inflammatory drug piroxicam, different polymer libraries were prepared by varying the six factors according to a two-level fractional factorial design of resolution VI. This optimization resulted in polymers showing high affinity as a result, mainly, of reduced binding to the non-imprinted polymers. The type of cross-linker showed a strong influence on the specific binding of the template when assessed by equilibrium rebinding experiments. The cross-linking monomer divinylbenzene gave rise to an enhancement in the binding capacity of the MIP that may be attributed to its similar structure with the functional monomer considered (4-vinylpyridine). The binding capacity of the MIP and blank polymers was related to the six experimental factors using a partial least squares regression (PLS) method. The regression models of the polymer libraries showed the same trend in the MIP and blank polymers, suggesting a higher specific binding capacity when the polymerization was photoinitiated at low temperature; the amounts of the functional monomer and the cross-linker were similar. The proposed procedure is time and cost effective and can be used as a general tool for preparing MIPs for different analytes. The proposed method provides new insight into the influence and interaction of the main factors that affect the MIP performance that could facilitate improvements in the MIP process design in the future.
Specific Acceleration of the Hydrogenation of Methyl Acetoacetate on Enantio-Differentiating Sites of a Tartaric Acid-Modified Nickel Catalyst by the Addition of Acetic Acid to the Reaction Media
Authors: Osawa Tsutomu , Ando Masashi , Harada Tadao , Takayasu Osamu 
Published: July 2005

Abstract
The hydrogenation of methyl acetoacetate on enantio-differentiating sites of a tartaric acid-modified nickel catalyst was specifically accelerated by the addition of acetic acid to the reaction media to increase the enantio-differentiating ability of the catalyst.
Influence of gender, age and renal function on plasma adiponectin level: the Tanno and Sobetsu study
Authors: Isobe Takeshi , Saitoh Shigeyuki , Takagi Satoru , Takeuchi Hiroshi , Chiba Yu , Katoh Nobuo , Shimamoto Kazuaki 
Published: July 2005

Design: The aim of this study was to determine the association between aging and adiponectin level from the aspect of the influence of renal function and sex hormones in humans.Methods: Serum adiponectin and blood urea nitrogen (BUN) levels were measured in 964 subjects (372 males) aged 60.3±12.5 years. Testosterone and free testosterone levels were measured in 123 males, and estrone and estradiol levels were measured in 114 females. The subjects were divided into two age groups; 65 years of age or older (Age ≥65 group) and less than 65 years of age (Age <65 group).Results: Adiponectin level increased linearly with aging in males, whereas it increased dramatically in females until their 50s. The patterns of changes in adiponectin were similar to those in BUN. In multiple- regression analysis using adiponectin as a dependent variable BUN was selected as a significant independent variable in all subjects and in subjects in the Age ≥65 group, whereas bioactive sex hormones were not selected.Conclusions: A decrease in adiponectin clearance in the kidney may be the cause of high levels of adiponectin in the elderly. Adiponectin level seems to be influenced more strongly by BUN than by sex hormones and to be increased by a decline in renal function with aging.
Hip bone mineral density, bone turnover and risk of fracture in patients on long-term suppressive L-thyroxine therapy for differentiated thyroid carcinoma
Authors: Heijckmann A Caroline , Huijberts Maya S P , Geusens Piet , de Vries Jolanda , Menheere Paul P C A , Wolffenbuttel Bruce H R 
Published: July 2005

Objective: Untreated hyperthyroidism and treatment with high doses of thyroid hormone are associated with osteoporosis. However, their effect on bone turnover, their contribution to bone mineral density (BMD) in the context of other clinical risk factors for osteoporosis and the prevalence of vertebral fractures is not well documented.
Design: Cross-sectional study.
Methods: We studied 59 patients receiving L-thyroxine suppressive therapy for differentiated thyroid carcinoma (DTC). BMD of the hip was measured by dual X-ray absorptiometry (DXA) and lateral DXA pictures of the lumbar and thoracic vertebrae were performed. Bone resorption was measured by C-telopeptides of type I collagen (ICTP) and bone formation by procollagen type I N-propeptide (PINP). Clinical risk factors for osteoporosis were evaluated using a questionnaire.
Results: Z-scores of BMD were similar as the NHANES (National Health and Nutrition Examination Survey) III reference group in women and men, also after long-term (>10 years) suppression therapy. Patients in the lowest and highest quartile of BMD showed significant differences in the presence of clinical risk factors. ICTP levels were significantly higher than in age-matched controls, PINP levels were not different. We found four patients with a prevalent vertebral fracture.
Conclusions: We conclude that patients with well-differentiated thyroid carcinoma are not at increased risk of developing low bone mass nor have a higher prevalence of vertebral fracture at least when treated with relatively low doses of l-thyroxine.
Limited predictive value of an acute test with subcutaneous octreotide for long-term IGF-I normalization with Sandostatin LAR in acromegaly
Authors: de Herder Wouter W , Taal H Rob , Uitterlinden Piet , Feelders Richard A , Janssen Joop A M J L , van der Lely Aart-Jan 
Published: July 2005

Objectives: To study whether the growth hormone (GH) response after the subcutaneous administration 50 μg of octreotide (acute octreotide test) has any predictive value for long-term IGF-I normalization with Sandostatin LAR.
Design: Twenty four therapy-naive patients with active acromegaly were studied.
Results: >75% GH decrease in the acute octreotide test predicted long-term IGF-I normalization with Sandostatin LAR in 8/11 (73%) of patients. 3/13 (23%) patients with <75% GH decrease in the acute octreotide test were long-term biochemically controlled with Sandostatin LAR. Using the >75% GH reduction criterion, the sensitivity and specificity of this test for predicting long-term normalization of serum IGF-I with Sandostatin LAR treatment were 73% and 77%, respectively (positive and negative predictive values: 73% and 77%, respectively). 6/8 (75%) patients with GH suppression to levels <1.1 μg/l and 9/16 (56%) patients with GH suppression to levels <2 μg/l in the acute octreotide test showed normalization of serum IGF-I with long-term Sandostatin LAR treatment. The sensitivity and specificity of GH suppression <1.1 μg/l for predicting of the long-term normalization of serum IGF-I with Sandostatin LAR therapy were 55% and 85%, respectively (positive and negative predictive values: 75% and 69%, respectively). The sensitivity and specificity of GH suppression <2 μg/l for predicting of the long-term normalization of serum IGF-I with Sandostatin LAR therapy were 82% and 46%, respectively (positive and negative predictive values: 56% and 75%, respectively).
Conclusion: The acute octreotide is not recommended for clinical decision making with regard to long-term treatment using the long-acting somatostatin analog Sandostatin LAR in acromegaly.
Differential gene expression in pituitary adenomas by oligonucleotide array analysis
Authors: Morris Damian G , Muşat Mädälina , Czirják Sándor , Hanzély Zoltán , Lillington Debra M , Korbonits Márta , Grossman Ashley B 
Published: July 2005

Objectives: Microarray technology allows for the expression profile of many thousands of genes to be quantified at the same time, and has resulted in novel discoveries about the tumour biology of a number of cancers. We sought to do this in pituitary adenomas, the most common intracranial neoplasm.
Methods: Affymetrix GeneChip HG-U133A oligonucleotide arrays covering 14 500 well-characterised genes from the human genome were used to study pooled RNA for each of the four major pituitary adenoma subtypes. Individual gene-expression levels in the tumours were compared relative to the expression profile in normal pooled pituitary RNA. Three differentially expressed genes with potential importance in tumourigenesis were chosen for validation by real-time quantitative PCR on the original tumours and on an additional 26 adenomas.
Results: Bioinformatic analysis showed that 3906 genes and 351 expressed sequence tags were differentially expressed among all pituitary tumour subtypes. Lysosomal-associated protein transmembrane- 4-β (LAPTM4B), a novel gene upregulated in hepatocellular carcinoma, was significantly over-expressed in adrenocorticotrophin (ACTH)-secreting adenomas and non-functioning pituitary adenomas (NFPAs). Bcl-2-associated athanogene (BAG1), an anti-apoptotic protein found at high levels in a number of human cancers, was significantly over-expressed in growth hormone-secreting and prolactin-secreting adenomas and NFPAs. The cyclin-dependent kinase inhibitor p18, in which murine gene deletion has been shown to produce pituitary ACTH cell hyperplasia and adenomas, was significantly under-expressed in ACTH-secreting adenomas.
Conclusions: Expression array analysis of pituitary adenomas using the Affymetrix GeneChip HG-U133A arrays appears to be a valid method of identifying genes that may be important in tumour pathogenesis.