bluuebunny/crossref_metadata_2025 huggingface dataset:
Chemotherapy improves low performance status lung cancer patients
Authors: Sculier J. P. , Lafitte J. J. , Paesmans M. , Lecomte J. , Alexopoulos C. G. , Van Cutsem O. , Giner V. , Efremidis A. , Berchier M. C. , Collon T. , Meert A. P. , Scherpereel A. , Ninane V. , Koumakis G. , Vaslamatzis M. M. , Leclercq N. , Berghmans T.
Published: August 2007

The aim of the present study was to determine the potential benefit of conventional cisplatin-based chemotherapy on patients with advanced nonsmall cell lung cancer (NSCLC) and poor performance status (PS), defined as 60–70 on the Karnofsky scale.

Retrospective analysis was carried out of a randomised trial performed in advanced NSCLC where 485 patients received three courses of gemcitabine+ifosfamide+cisplatin induction chemotherapy.

Of the patients, 80% had good PS (Karnofsky 80–100) and 20% poor PS. Response rates were 38 and 28%, respectively. Clinical improvement, defined as achieving a good PS during chemotherapy, was observed overall in 25% of the poor PS patients, with rates of 38, 20 and 14%, respectively, in case of response, no change and progression. PS improved more quickly in the responders. Survival of patients with poor PS was significantly worse, but survival of responders was similar, irrespective of the initial poor or good PS. Although nonfatal toxicity was almost similar, there were more toxic deaths (including vascular and cardiac fatalities) in the poor PS patients (9.2versus2.1%).

In conclusion, combination chemotherapy is associated with clinical improvement in a substantial number of patients with advanced nonsmall cell lung cancer of poor performance status.
Long-term treatment with sildenafil in chronic thromboembolic pulmonary hypertension
Authors: Reichenberger F. , Voswinckel R. , Enke B. , Rutsch M. , El Fechtali E. , Schmehl T. , Olschewski H. , Schermuly R. , Weissmann N. , Ghofrani H. A. , Grimminger F. , Mayer E. , Seeger W.
Published: August 2007

For chronic thromboembolic pulmonary hypertension not amenable to pulmonary endarterectomy, effective medical therapy is desired.

In an open-label uncontrolled clinical trial, 104 patients (mean±semage 62±11 yrs) with inoperable chronic thromboembolic pulmonary hypertension were treated with 50 mg sildenafilt.i.d.At baseline, patients had severe pulmonary hypertension (pulmonary vascular resistance 863±38 dyn·s·cm−5) and a 6-min walking distance of 310±11 m. Eight patients were in World Health Organization functional class II, 76 in class III and 20 in class IV.

After 3 months’ treatment, there was significant haemodynamic improvement, with reduction of pulmonary vascular resistance to 759±62 dyn·s·cm−5. The 6-min walking distance increased significantly to 361±15 m after 3 months’ treatment, and to 366±18 m after 12 months’ treatment. A subset of 67 patients received a single dose of 50 mg sildenafil during initial right heart catheterisation. The acute haemodynamic effect of this was not predictive of long-term outcome.

In this large series of patients with inoperable chronic thromboembolic pulmonary hypertension, open-label treatment with sildenafil led to significant long-term functional improvement. The acute effect of sildenafil may not predict the long-term outcome of therapy.
Premature discontinuation of patients: a potential bias in COPD clinical trials
Authors: Kesten S. , Plautz M. , Piquette C. A. , Habib M. P. , Niewoehner D. E.
Published: August 2007

Premature discontinuation from clinical trials may bias results against effective therapies.

In the present study mortality rates were retrospectively reviewed in a 6-month, randomised, placebo-controlled trial in which tiotropium 18 μg daily was shown to decrease chronic obstructive pulmonary disease exacerbations. Patients participated for 6 months even if trial medication was prematurely discontinued. Exposure-adjusted incidence rates (IRs) were calculated for randomisation–end trial, randomisation–end trial drug (0–ED) and end trial drug–end trial (ED–ET).

Of 1,829 patients (forced expiratory volume in one second 1.04 L (36% predicted), mean age 68 yrs, 99% male), 16% tiotropium and 27% placebo patients prematurely stopped trial medication. The number of fatal events for the entire cohort was: 62 all cause, including 16 cardiac and 16 lower respiratory. IRs for fatal events per 100 patient-yrs were higher in the discontinued period: 1.9 (0–ED)versus23.0 (ED–ET) in the tiotropium group and 1.8versus19.0 in the placebo group. Respective IRs for fatal cardiac events were 0.7versus2.8 (tiotropium) and 0.5versus6.2 (placebo); for fatal lower respiratory events were 0.7versus2.8 (tiotropium) and 0.8versus5.4 (placebo). Rate ratios (tiotropium/placebo) for fatal events were lower in the discontinued period: 1.4versus0.5 for cardiac and 0.9versus0.5 for lower respiratory.

Higher incidence rates of fatal events occurred following premature discontinuation of study medication. Incomplete information from rate ratios occurs as a result of failure to consider outcomes of patients who discontinue early from clinical trials.
Analgesic and anti-inflammatory drug use and risk of bladder cancer: a population based case control study
Authors: Fortuny Joan , Kogevinas Manolis , Zens Michael S , Schned Alan , Andrew Angeline S , Heaney John , Kelsey Karl T , Karagas Margaret R
Published: August 2007

Background

Use of phenacetin and other analgesic and non-steroidal anti-inflammatory drugs (NSAIDs) potentially influences bladder cancer incidence, but epidemiologic evidence is limited.

Methods

We analyzed data from 376 incident bladder cancer cases and 463 controls from a population-based case-control study in New Hampshire on whom regular use of analgesic drugs and NSAIDs was obtained. Odds ratios and 95% confidence intervals were computed using logistic regression with adjustment for potentially confounding factors. Separate models by tumor stage, grade and TP53 status were conducted.

Results

We found an elevated odds ratio (OR) associated with reported use of phenacetin-containing medications, especially with longer duration of use (OR >8 years = 3.00, 95% confidence interval (CI) = 1.4–6.5). In contrast, use of paracetamol did not relate overall to risk of bladder cancer. We also found that regular use of any NSAID was associated with a statistically significant decrease in bladder cancer risk (OR = 0.6, 95% CI = 0.4–0.9), and specifically use of aspirin. Further, the association with NSAID use was largely among invasive, high grade and TP53 positive tumors.

Conclusion

While these agents have been investigated in several studies, a number of questions remain regarding the effects of analgesic and NSAID use on risk of bladder cancer.
Proteomic analysis of plasma membrane and secretory vesicles from human neutrophils
Authors: Jethwaney Deepa , Islam Md Rafiqul , Leidal Kevin G , de Bernabe Daniel Beltran-Valero , Campbell Kevin P , Nauseef William M , Gibson Bradford W
Published: August 2007

Background

Polymorphonuclear neutrophils (PMN) constitute an essential cellular component of innate host defense against microbial invasion and exhibit a wide array of responses both to particulate and soluble stimuli. As the cells recruited earliest during acute inflammation, PMN respond rapidly and release a variety of potent cytotoxic agents within minutes of exposure to microbes or their products. PMN rely on the redistribution of functionally important proteins, from intracellular compartments to the plasma membrane and phagosome, as the means by which to respond quickly. To determine the range of membrane proteins available for rapid recruitment during PMN activation, we analyzed the proteins in subcellular fractions enriched for plasma membrane and secretory vesicles recovered from the light membrane fraction of resting PMN after Percoll gradient centrifugation and free-flow electrophoresis purification using mass spectrometry-based proteomics methods.

Results

To identify the proteins light membrane fractions enriched for plasma membrane vesicles and secretory vesicles, we employed a proteomic approach, first using MALDI-TOF (peptide mass fingerprinting) and then by HPLC-MS/MS using a 3D ion trap mass spectrometer to analyze the two vesicle populations from resting PMN. We identified several proteins that are functionally important but had not previously been recovered in PMN secretory vesicles. Two such proteins, 5-lipoxygenase-activating protein (FLAP) and dysferlin were further validated by immunoblot analysis.

Conclusion

Our data demonstrate the broad array of proteins present in secretory vesicles that provides the PMN with the capacity for remarkable and rapid reorganization of its plasma membrane after exposure to proinflammatory agents or stimuli.
A continuum mathematical model of endothelial layer maintenance and senescence
Authors: Wang Ying , Aguda Baltazar D , Friedman Avner
Published: August 2007

Background

The monolayer of endothelial cells (ECs) lining the inner wall of blood vessels deteriorates as a person ages due to a complex interplay of a variety of causes including cell death arising from shear stress of blood flow and cellular oxidative stress, cellular senescence, and decreased rate of replacement of dead ECs by progenitor stem cells.

Results

A continuum mathematical model is developed to describe the dynamics of large EC populations of the endothelium using a system of differential equations for the number densities of cells of different generations starting from endothelial progenitors to senescent cells, as well as the densities of dead cells and the holes created upon clearing dead cells. Aging of cells is manifested in three ways, namely, losing the ability to divide when the Hayflick limit of 50 generations is reached, decreasing replication rate parameters and increasing death rate parameters as cells divide; due to the dependence of these rate parameters on cell generation, the model predicts a narrow distribution of cell densities peaking at a particular cell generation. As the chronological age of a person advances, the peak of the distribution – corresponding to the age of the endothelium – moves towards senescence correspondingly. However, computer simulations also demonstrate that sustained and enhanced stem cell homing can halt the aging process of the endothelium by maintaining a stationary cell density distribution that peaks well before the Hayflick limit. The healing rates of damaged endothelia for young, middle-aged, and old persons are compared and are found to be particularly sensitive to the stem cell homing parameter.

Conclusion

The proposed model describes the aging of the endothelium as being driven by cellular senescence, with a rate that does not necessarily correspond to the chronological aging of a person. It is shown that the age of the endothelium depends sensitively on the homing rates of EC progenitor cells.
Prostaglandin E2 Potentiation of P2X3 Receptor Mediated Currents in Dorsal Root Ganglion Neurons
Authors: Wang Congying , Li Guang-Wen , Huang Li-Yen Mae
Published: August 2007

Prostaglandin E2 (PGE2) is a well-known inflammatory mediator that enhances the excitability of DRG neurons. Homomeric P2X3 and heteromeric P2X2/3 receptors are abundantly expressed in dorsal root ganglia (DRG) neurons and participate in the transmission of nociceptive signals. The interaction between PGE2 and P2X3 receptors has not been well delineated. We studied the actions of PGE2 on ATP-activated currents in dissociated DRG neurons under voltage-clamp conditions. PGE2 had no effects on P2X2/3 receptor-mediated responses, but significantly potentiated fast-inactivating ATP currents mediated by homomeric P2X3 receptors. PGE2 exerted its action by activating EP3 receptors. To study the mechanism underlying the action of PGE2, we found that the adenylyl cyclase activator, forskolin and the membrane-permeable cAMP analogue, 8-Br-cAMP increased ATP currents, mimicking the effect of PGE2. In addition, forskolin occluded the enhancement produced by PGE2. The protein kinase A (PKA) inhibitors, H89 and PKA-I blocked the PGE2 effect. In contrast, the PKC inhibitor, bisindolymaleimide (Bis) did not change the potentiating action of PGE2. We further showed that PGE2 enhanced α,β-meATP-induced allodynia and hyperalgesia and the enhancement was blocked by H89. These observations suggest that PGE2 binds to EP3 receptors, resulting in the activation of cAMP/PKA signaling pathway and leading to an enhancement of P2X3 homomeric receptor-mediated ATP responses in DRG neurons.
GnRH and LHRgene variants predict adverse outcome in premenopausal breast cancer patients
Authors: Piersma Djura , Themmen Axel PN , Look Maxime P , Klijn Jan GM , Foekens John A , Uitterlinden André G , Pols Huibert AP , Berns Els MJJ
Published: August 2007

Background

Breast cancer development and progression are dependent on estrogen activity. In premenopausal women, estrogen production is mainly regulated through the hypothalamic-pituitary-gonadal (HPG) axis.

Methods

We have investigated the prognostic significance of two variants of genes involved in the HPG-axis, the GnRH (encoding gonadotropin-releasing hormone) 16Trp/Ser genotype and the LHR (encoding the luteinizing hormone receptor) insLQ variant, in retrospectively collected premenopausal breast cancer patients with a long follow-up (median follow-up of 11 years for living patients).

Results

Carriership was not related with breast cancer risk (the case control study encompassed 278 premenopausal cases and 1,758 premenopausal controls). A significant adverse relationship of the LHR insLQ and GnRH 16Ser genotype with disease free survival (DFS) was observed in premenopausal (hormone receptor positive) breast cancer patients. In particular, those patients carrying both the GnRH 16Ser and LHR insLQ allele (approximately 25%) showed a significant increased risk of relapse, which was independent of traditional prognostic factors (hazard ratio 2.14; 95% confidence interval 1.32 to 3.45; P = 0.002).

Conclusion

We conclude that the LHR insLQ and GnRH 16Ser alleles are independently associated with shorter DFS in premenopausal patients. When validated, these findings may provide a lead in the development of tailored treatment for breast cancer patients carrying both polymorphisms.
Coxsackievirus and Adenovirus Receptor Is Up-Regulated in Migratory Germ Cells during Passage of the Blood-Testis Barrier
Authors: Mirza Momina , Petersen Cecilia , Nordqvist Katarina , Sollerbrant Kerstin
Published: August 2007

The coxsackievirus and adenovirus receptor (CAR) is a cell adhesion molecule expressed in epithelial tight junctions and other cell-cell contacts. Using indirect immunofluorescence, quantitative RT-PCR, and Western blots, the expression and distribution of CAR in developing and adult testis are examined. CAR is highly expressed in both Sertoli and germ cells during perinatal and postnatal development, followed by a rapid down-regulation of both mRNA and protein levels. Interestingly, we find that CAR is a previously unknown downstream target for FSH because CAR mRNA levels were induced in primary cultures of FSH-stimulated Sertoli cells. In contrast to other epithelia, CAR is not a general component of tight junctions in the seminiferous epithelium, and Sertoli cells in the adult testis do not express CAR. Instead, CAR expression is stage dependent and specifically found in migratory germ cells. RT-PCR also demonstrated the presence of junctional adhesion molecule-like (JAML) in the testis. JAML was previously reported by others to form a functional complex with CAR regulating transepithelial migration of leukocytes. The expression of JAML in the testis suggests that a similar functional complex might be present during germ cell migration across the blood-testis barrier. Finally, an intermediate compartment occupied by CAR-positive, migrating germ cells and flanked by two occludin-containing junctions is identified. Together, these results implicate a function for CAR in testis morphogenesis and in migration of germ cells across the blood-testis barrier during spermatogenesis.
β-catenin/TCF/Lef controls a differentiation-associated transcriptional program in renal epithelial progenitors
Authors: Schmidt-Ott Kai M. , Masckauchan T. Nestor H. , Chen Xia , Hirsh Benjamin J. , Sarkar Abby , Yang Jun , Paragas Neal , Wallace Valerie A. , Dufort Daniel , Pavlidis Paul , Jagla Bernd , Kitajewski Jan , Barasch Jonathan
Published: August 2007

In the embryonic kidney, progenitors in the metanephric mesenchyme differentiate into specialized renal epithelia in a defined sequence characterized by the formation of cellular aggregates, conversion into polarized epithelia and segmentation along a proximal-distal axis. This sequence is reiterated throughout renal development to generate nephrons. Here, we identify global transcriptional programs associated with epithelial differentiation utilizing an organ culture model of rat metanephric mesenchymal differentiation, which recapitulates the hallmarks of epithelialization in vivo in a synchronized rather than reiterative fashion. We observe activation of multiple putative targets ofβ-catenin/TCF/Lef-dependent transcription coinciding with epithelial differentiation. We show in cultured explants that isolated activation ofβ-catenin signaling in epithelial progenitors induces, in a TCF/Lef-dependent manner, a subset of the transcripts associated with epithelialization, including Pax8, cyclin D1 (Ccnd1) and Emx2. This is associated with anti-apoptotic and proliferative effects in epithelial progenitors, whereas cells with impaired TCF/Lef-dependent transcription are progressively depleted from the epithelial lineage. In vivo,TCF/Lef-responsive genes comprise a conserved transcriptional program in differentiating renal epithelial progenitors and β-catenin-containing transcriptional complexes directly bind to their promoter regions. Thus,β-catenin/TCF/Lef-mediated transcriptional events control a subset of the differentiation-associated transcriptional program and thereby participate in maintenance, expansion and stage progression of the epithelial lineage.
Understanding Clusters toward the Design of Functional Molecules and Nanomaterials
Authors: Singh N Jiten , Lee Eun Cheol , Choi Young Cheol , Lee Han Myoung , Kim Kwang S
Published: August 2007

In this account, we highlight the theoretical investigations of various cluster systems comprising of water clusters, π-containing clusters, and metallic clusters. We illustrate how these investigations help us understand and design structures and properties of nanowires, novel functional ionophores/receptors, and nanomaterials. Many of these theoretically predicted systems have been experimentally realized and some of the predicted structures/properties are left for the future which of course could be promising challenges for experimentalists.
Chiral Glycolate Equivalents for the Asymmetric Synthesis of α-Hydroxycarbonyl Compounds
Authors: Ley Steven V , Sheppard Tom D , Myers Rebecca M , Chorghade Mukund S
Published: August 2007

Chiral glycolic acid equivalents are used extensively for the enantioselective synthesis of α-hydroxycarbonyl compounds. Their efficacy in enolate reactions and their utility in synthetic applications are discussed, highlighting the relevance of these methods to natural product synthesis.
Energy-Transfer Mechanism in Photoluminescent Terbium(III) Complexes Causing Their Temperature-Dependence
Authors: Katagiri Shinya , Tsukahara Yasunori , Hasegawa Yasuchika , Wada Yuji
Published: August 2007

Photoluminescence of Terbium(III) complexes was investigated as a function of temperatures in the range of 80–280 K for [Tb(bfa)3(H2O)2] (bfa: 4,4,4-trifluoro-1-phenyl-1,3-butanedionato), [Tb(hfa)3(H2O)3] (hfa: hexafluoroacetylacetonato), [Tb(tfa)3(H2O)2] (tfa: trifluoroacetylacetonato), [Tb(acac)3(H2O)3] (acac: acetylacetonato), and [Tb(hfa)3(tppo)2] (tppo: triphenylphosphine oxide). These complexes were classified into the two groups with different temperature-dependences. The first group consisting of [Tb(bfa)3(H2O)2], [Tb(tfa)3(H2O)2], and [Tb(acac)3(H2O)3] showed a dependence determined by the energy gap between the excited triplet state of the ligand and the emitting level of terbium(III) ion. In contrast, for [Tb(hfa)3(H2O)3] and [Tb(hfa)3(tppo)2] containing hfa as a ligand, not only the energy gap but also the energy barriers of the “Forward energy transfer” from the ligand to terbium(III) ion and “Back energy transfer” from terbium(III) ion to the ligand were taken into account for understanding their dependences. These results are discussed based on the re-orientation of the complexes accompanied by the forward and back energy transfer processes using DFT calculations.
Voltammetric Study of Two-Dimensional Phase-Transition Processes of Carboxylated Viologens at an HOPG Electrode as a Typical Organization Process of Molecules Possessing Multiple Interaction Sites
Authors: Tanaka Yasuhiko , Sagara Takamasa
Published: August 2007

Two-dimensional (2D) phase-transition behavior of three different viologens, heptyl viologen and its mono- and dicarboxylated derivatives, is described using the results of voltammetric measurements at an HOPG electrode. The transition was regarded as a typical 2D molecular organization process under oxidation state control. In an acidic medium, the width of the bi-stable potential region of the phase-transition was found to increase by approximately 55 mV with each addition of a carboxylate group. This fact points to a dominant contribution from intermolecular hydrogen bonding to the reductive formation of the 2D condensed phase. The occurrence of an incomplete transition process resulting in the formation of a metastable phase at lower temperatures, higher potential sweep rates, and higher concentrations was observed for dicarboxylated viologen, but not for monocarboxylated one. These results were used to discuss the advantages and disadvantages of multiple intermolecular interaction sites in a molecule in relation to the 2D molecular organization processes.
Ternary Inclusion Complexes of γ-Cyclodextrin with Resorufin and Organic Cations in Aqueous Solution
Authors: Hamai Sanyo
Published: August 2007

Molecular interactions of an organic anion, resorufin (Res), with γ-cyclodextrin (γ-CD) and several organic cations were investigated by means of absorption and fluorescence spectroscopy. A 1:1 inclusion complex is formed between γ-CD and Res. In addition, Res forms a 1:1 organic cation–organic anion complex with 1,1′-diheptyl-4,4′-bipyridyl dibromide (DHB) and 1,1′-dimethyl-4,4′-bipyridyl dibromide (DMB), although Res does not form an organic cation–organic anion complex with trimethyloctylammonium bromide (TMOA). The γ-CD–Res inclusion complex forms a ternary inclusion complex with TMOA, DHB, and DMB. The equilibrium constant for the formation of the 1:1:1 γ-CD–Res–TMOA inclusion complex is nearly the same as that of the 1:1:1 γ-CD–Res–DHB inclusion complex. On the other hand, the equilibrium constant for the formation of the 1:1:1 γ-CD–Res–DMB inclusion complex is significantly less than that of 1:1:1 γ-CD–Res–DHB inclusion complex. These findings suggest that the long alkyl-chain in the organic cations examined promotes the formation of a ternary inclusion complex of Res.
Synthesis and Electrochemical Properties of Tetranuclear Di-μ-oxo-bis[di-μ-phenolatodiiron(III)] Complexes
Authors: Miyazato Yuji , Ohba Masaaki , Sakiyama Hiroshi , Ōkawa Hisashi
Published: August 2007

A series of tetrairon(III) complexes of di-μ-oxo-bis[di-μ-phenolatodiiron(III)] core, [{Fe2(L)(L′)}2(μ-O)2](PF6)2 (1–11), where L2− is the phenol-based macrocyclic compartmental ligand and (L′)− is acetate, monochloroacetate, dichloroacetate, trifluoroacetate, pentafluoropropionate, benzoate, p-nitrobenzoate, pentafluorobenzoate, diethyl phosphate, diphenyl phosphate, or diethyldithiophosphate for 1–11, respectively, were synthesized. X-ray crystallographic studies for 4, 7, and 9 indicated that two {Fe2(L)(L′)} units were connected by two oxo bridges to afford a tetranuclear di-μ-oxo-bis[di-μ-phenolatodiiron(III)] core. Cyclic voltammograms of 1–11 in acetonitrile showed a quasi-reversible or irreversible reduction wave between −332 and −620 mV (vs. Ag/Ag+), which were attributed to a two-electron process involving the Fe4III,III,III,III/Fe4II,II,III,III. The Fe4III,III,III,III/Fe4II,II,III,III potential shifted positive with a decrease in the electron-donating ability of the end-cap ligand, and a good linear correlation was found between the potentials and the pKa values of HL′. The Fe4II,II,III,III species were generated in acetonitrile by electrochemical reduction and showed broad intervalence transition bands in the range of 900–1500 nm.
Synthesis and Characterization of a Novel Quinoxaline-Substituted vic-Dioxime and Its Complexes Containing Bis(12-Diazacrown-4) Derivatives
Authors: Bilgin Ahmet , Ertem Beytullah , Gök Yasar
Published: August 2007

A new quinoxaline-substituted vicinal dioxime ligand containing bis(12-diazacrown-4) units (H2L) was synthesized by the reaction of cyanogen di-N-oxide with compound 4. Mononuclear NiII and CuII complexes with a metal:ligand ratio of 1:2 for H2L and a trinuclear CuII complex were also synthesized. The mononuclear CuII species coordinated to two CuII ions through the deprotonated oximate oxygens to yield a trinuclear structure cis-bridged by the oximate groups, with 1,10-phenanthroline as an end-cap ligand. The mononuclear CoIII complex of H2L was isolated with pyridine and chlorine as axial ligands. In addition, a CoIII complex containing the BF2+ bridge macrocycle was synthesized using a precursor hydrogen-bridged CoIII complex via a template effect. The extraction abilities of 1, 3, and 11 were also evaluated in 1,2-dichloroethane by using several alkali (Li+, Na+, K+, and Cs+) and transition-metal picrates, such as Ag+, Pb2+, Cd2+, Cu2+, and Zn2+. Structures of the ligands and metal complexes were solved by elemental analyses, 1H and 13C NMR, FT-IR, UV–vis, and mass spectra.
Synthesis and Properties of 5-(3-Pyridyl)porphyrinatoruthenium(II) Tetramers
Authors: Funatsu Kenji , Yasuda Naomi , Ichimura Akio , Santo Ryoko , Sasaki Yoichi , Imamura Taira
Published: August 2007

5-(3-Pyridyl)porphyrinatoruthenium(II) tetramers, [{Ru(3-PyT3porph)(CO)}4] (1), [{Ru(3-PytB3porph)(CO)}4] (2), [{Ru(3-PyHex3porph)(CO)}4] (3), and [{Ru(3-PytB3porph)(py)}4] (4) were prepared. The structures of the isolated tetramers were determined to be rhombic shaped with two chemically nonequivalent porphyrinatoruthenium(II) subunits by 1H NMR, IR, and ESI-MS measurements. The tetramers were stable in benzene at 70 °C. However, the tetramers reacted with a large excess of pyridine to give two geometrical isomers of porphyrinatoruthenium(II) in dichloromethane at room temperature as observed by 1H NMR spectrometry. UV–vis spectra of the tetramers showed splitting or broadening of the Soret band due to excitonic interactions. Stepwise oxidations of the porphyrin rings or the ruthenium ions in the cyclic tetramer skeleton were observed in cyclic voltammograms.
Enantioselectivity in Electron-Transfer Reactions between Cytochrome c and (S)-/(R)-Ruthenium Complexes. Non-Polar Interaction in a Molecular Recognition Process
Authors: Kato Takashi , Takahashi Isao , Kumita Hideyuki , Ozawa Tomohiro , Funahashi Yasuhiro , Jitsukawa Koichiro , Masuda Hideki
Published: August 2007

Redox reactions between horse heart cytochrome c and optically active Ru complexes were kinetically studied. The kinetic parameters for the oxidation of ferrocytochrome c with RuIII complexes indicated an apparent enantioselectivity, which clearly shows that exact molecular recognition is achieved through non-polar interactions rather than electrostatic ones.
Studies on Ring-Closing Metathesis for the Formation of the 11-Membered Ring System of Daphnezomine C
Authors: Tanabe Kazuhisa , Fujie Ayako , Ohmori Naoki , Hiraga Yoshikazu , Kojima Satoshi , Ohkata Katsuo
Published: August 2007

For the purpose of synthesizing daphnezomine C, model systems were examined to see if the ring-closing metathesis (RCM) reaction could be applied to prepare an 11-membered ring system bearing a tri-substituted alkene. As a result, it was found that the connectivity pattern of the tethers bearing the reacting alkene moieties was crucial. Thus, whereas a system involving a single 1,3- or 1,4-disubstituted cyclohexane derivative did not give RCM products, a flexible system without any rings between the two terminal alkenes gave the cyclic product with a yield of up to 65% using the second generation Grubbs catalyst.
Synthesis of Perfluorinated Ketones by Utilizing Liquid-Phase Direct Fluorination
Authors: Okazoe Takashi , Watanabe Kunio , Itoh Masahiro , Shirakawa Daisuke , Takagi Hirokazu , Kawahara Kengo , Tatematsu Shin
Published: August 2007

A new synthetic procedure for the preparation of perfluorinated ketones from nonfluorinated sec-alcohols was developed. A key step in the synthetic route was a liquid-phase direct fluorination reaction with elemental fluorine. Direct fluorination of a partially fluorinated ester, which was prepared from a nonfluorinated sec-alcohols and a perfluorinated acyl fluoride, followed by thermal elimination, gave a perfluorinated ketone and the starting perfluorinated acyl fluoride, which could be recycled. Application to the synthesis of a precursor polyfluoroketone for fluoropolymer resists for 157 nm microlithography was also established.
Efficient Way to Attach Organosilyl Groups in the Interlayer Space of Layered Solids
Authors: Ide Yusuke , Ogawa Makoto
Published: August 2007

An efficient method to immobilize silane-coupling reagents on the interlayer space of a layered silicate, magadiite (Na2Si14O29·nH2O), is reported. The silylation was conducted by concentrating a mixture containing the pre-synthesized dodecyltrimethylammonium-exchanged magadiite and a stoichiometric amount (molar ratio of silane-coupling reagent/Si14O29 unit of magadiite = 2.0) of (3-mercaptopropyl)trimethoxysilane. The resulting silylated derivative possessed basal spacing and had a composition comparable to those of the silylated derivative, prepared by using a previous silylation method, which involves dodecyltrimethylammonium-exchanged form with a much larger amount (molar ratio of silane-coupling reagent/Si14O29 unit of magadiite = 57) of the silane-coupling reagent. When the present method was employed, the surface coverage with (3-mercaptopropyl)silyl groups on the layer surface directly correlated to the amount of the silane-coupling reagent.
Celiac Disease: Are Endomysial Antibody Test Results Being Used Appropriately?
Authors: McGowan Kelly E , Lyon Martha E , Loken Steven D , Butzner J Decker
Published: August 2007

Background: The aim of this study was to retrospectively examine how positive IgA-endomysial antibody (EMA) test results for celiac disease were being interpreted and acted on by physicians in the Calgary Health Region.

Methods: We reviewed consecutive EMA test results, with or without a serum IgA, obtained during a 17-month period. Seropositive tests were cross-referenced to the surgical database to determine the number of patients who underwent intestinal biopsy and the results of the biopsy. We sent questionnaires to the ordering physicians of positive tests with no record of intestinal biopsy.

Results: Among 11 716 EMA tests in 9533 patients, 349 results were positive in 313 patients (3%). Intestinal biopsies were performed in 218 (70%) of the seropositive patients; 194 of them were diagnostic of celiac disease. Celiac disease was also found in 10 EMA-negative patients. Of the 109 positive tests performed in 95 patients with no subsequent biopsy, 28 had appropriate indications to not perform a biopsy; the most common reason being that the test had been ordered to follow up on a previous biopsy-proven diagnosis of celiac disease (n = 21). For 33 other positive test results without a subsequent biopsy, management appeared to be inappropriate, most commonly (n = 21) because of a recommendation to follow a gluten-free diet despite lack of a tissue diagnosis of celiac disease. For the remaining 48 positive EMA results, administrative issues prevented evaluation (n = 19), the patients refused further evaluation (n = 11), or physician surveys were not returned (n = 18).

Conclusions: Celiac disease affected 2% of patients, with a similar prevalence in male and female patients. Most positive EMA tests (77%) were appropriately managed by physicians. Beginning a gluten-free diet without biopsy or failing to follow up on a positive EMA test remain common errors of management.
Market Entry and Priority of Small and Medium-Sized Enterprises in the Software Industry: An Empirical Analysis of Cultural Distance, Geographic Distance, and Market Size
Authors: Ojala Arto , Tyrväinen Pasi
Published: August 2007

This article investigates the influence of cultural distance, geographic distance, and three market size variables in the target country preference of small and medium-sized enterprises (SMEs) in the software industry. In addition, the authors examine the shift of SMEs’ priorities in country selection by analyzing how these factors affect the selection of the first, second, and third target countries. The empirical findings suggest that approximately 70% of country choices can be explained by software market size and geographic distance alone. The findings also show that SMEs’ entry priorities shift quickly from countries within a short geographic distance to countries with high purchasing power and at a greater geographic distance. The authors discuss relationships of these macrolevel factors and compare them with prior qualitative and conceptual studies in this field. They also note implications for managers.
Product Ethnicity: Revisiting the Match between Products and Countries
Authors: Usunier Jean-Claude , Cestre Ghislaine
Published: August 2007

Consumers make stereotypical associations between products and countries based on their perceptions of a country's know-how and reputation relative to the design, manufacturing, or branding of particular generic goods. When such associations are shared globally, they reflect product ethnicity, a concept that the authors empirically explore in this article. Operationalization of product ethnicity is based on country–product associations that consumers make with either a product or a country as the initial stimulus, resulting in a combined two-way measurement. The authors first investigate product ethnicity at an exploratory level across five survey countries for a large set of products and countries (Study 1). They identify what they term “context-centered association tendencies” because respondents tend to associate goods more closely with their own country. The authors then relate product ethnicity and context-centered association tendencies to the country-of-origin literature and test research hypotheses with a new set of countries (Study 2), comprising two collectivist cultures (China and Mexico) and two individualist cultures (Germany and the United States). Finally, Study 3 shows that consumers are more willing to buy product offerings that are congruent rather than noncongruent with product ethnicity.
When, How, and with what Success? The Joint Effect of Entry Timing and Entry Mode on Survival of Japanese Subsidiaries in China
Authors: Papyrina Veronika
Published: August 2007

This study examines the question whether joint ventures or wholly owned subsidiaries are more likely to survive in the context of Japanese subsidiaries in China. The author suggests that the answer to this question depends on the time the subsidiary was established. Specifically, it is argued that joint ventures founded during the early stage of institutional reforms are more likely to survive than wholly owned subsidiaries set up at that time, and vice versa for subsidiaries established in the late phase of institutional reforms. The rationale for these propositions is that at the beginning of market-oriented reforms, contributions provided by local partners make shared ownership an optimal entry mode strategy, whereas a relatively stable regulatory framework in the late stage of institutional reforms enables the firm to realize benefits associated with sole ownership more efficiently. Empirical evidence supports both propositions.
Internationalization Motives and Facilitating Factors: Qualitative Evidence from Smaller Specialist Retailers
Authors: Hutchinson Karise , Alexander Nicholas , Quinn Barry , Doherty Anne Marie
Published: August 2007

Drawing on case study evidence, this article explores the reasons small specialist retailers internationalize and the facilitating factors that help them overcome the obstacles to internationalization. The authors employ qualitative research techniques and, to build theory from an unexplored area of research, adopt a multiple-case approach. The findings suggest that though a strong company brand identity is the most significant motive for expansion, other internal and external factors facilitate the international decision-making process.
Seasonal variations in the composition and gel quality of agar fromGracilaria edulisin the Philippines
Authors: Romero Jumelita B. , Montaño Marco Nemesio E. , Merca Florinia E. , Villanueva Ronald D. , Liao Ming-Long , Bacic Antony
Published: August 2007

Agar fromGracilaria eduliscollected in the Philippines is composed primarily of a repeating disaccharide unit of 4-linked 3,6-anhydro-α-L-galactopyranose (LA) and 3-linked 6-O-methyl-β-D-galactopyranose (G6M). Chemical and spectroscopic analyses further revealed partial (19–27 mol %) methylation at O-2 of the LA residues. Sulfate was attached to O-4 of G6M and/or G,with approximately 20% of these residues bearing the substituent. No pyruvate substituent was detected. A seasonal assessment of the composition, rheological and physical properties ofGracilaria edulisagar was undertaken. Constituent sugar analysis revealed a variable degree of methylation (80–91 mol % on O-6 of the G and 19–27 mol % on O-2 of the LA residues); the highest amounts of mono-O-methylated residues (G6M and LA2M) were found in the samples collected in the dry season while the lowest was obtained during the rainy season. The sample collected during the onset of the rainy season contained the lowest amount of sulfate (2.3%) while the cold season sample contained the highest sulfate content (3.2%). Seaweed samples collected during the onset of the rainy season exhibited the highest agar yield, gel strength, deformation, cohesiveness, and melting temperature.Gracilaria edulisagar possesses gel characteristics useful in the food industry.
A New Numerical Analysis for Rectangular Tensile Sheet with Single Edge Crack by Boundary Elements
Authors: Yan Xiangqiao
Published: August 2007

By using the hybrid displacement discontinuity method (a boundary element method) proposed recently by the author, in this note a new numerical analysis is presented for the stress intensity factors (SIFs) of rectangular tensile sheet with single edge crack. The new numerical results can reveal the effect of the boundaries parallel to the crack on the SIFs.
Cation–cation interaction in crystal structures of Np(V) and Pu(V) benzoate complexes with 2,2′-bipyridine, [NpO2(C10H8N2)(OOCC6H5)]2 and [PuO2(C10H8N2)(OOCC6H5)]2
Authors: Charushnikova I. A. , Krot N. N. , Starikova Z. A.
Published: August 2007

Single crystals of the Np(V) and Pu(V) benzoate complexes with 2,2′-bipyridine were prepared. According to X-ray diffraction analysis data, they are isostructural neutral dimers with the [AnO2(C10H8N2)(OOCC6H5)]2 (An = Np or Pu) composition. In crystals of these compounds the AnO2
+ are linked to each other in pairs, acting simultaneously as ligands and coordinating centers. Due to the cation-cationic interaction the dimeric An2O4
2+ cations are formed with the very short An…An distance equal to 3.4281(5) and 3.4088(14)Å for Np and Pu, respectively. The [NpO2(C10H8N2)(OOCC6H5)]2 complex is a new representative of compounds containing a very rare system of cation–cation bonds in the structure. The cation–cation bonds and the Pu2O4
2+ dimeric cations in the [PuO2(C10H8N2)(OOCC6H5)]2 structure have been found for the first time.
Spent fuel UO2 matrix alteration in aqueous media under oxidizing conditions
Authors: Jegou Christophe , Muzeau B. , Broudic V. , Roudil Danièle , Deschanels X.
Published: August 2007

The effects of αβγ radiolysis of water on oxidation and dissolution of the UO2 matrix of spent fuel were investigated in aerated media. The prospect of long-term interim storage of spent fuel assemblies in pools requires prior examination of an incident scenario in which a cladding failure could eventually lead to contact between water and the fuel. Radiolytic oxidation of the matrix together with the formation of secondary phases subject to volume expansion could then no longer be disregarded, and could enhance the degradation of the failed rod.

To determine the amplitude of the alteration various spent fuel leaching experiments conducted at different degrees of oxidizing conditions and of accessibility of species at the reaction interface are discussed. This work is based on modeling the radiolysis processes and on various possible interpretations of leaching test results. Properly interpreting these results implies full knowledge of the fuel sample history, and the development of a rigorous experimental approach to eliminate any artifacts (problems due to the residual inventory at the grain boundaries, or to inaccurate estimates of the actual surface area). The results indicate that despite highly variable oxidizing conditions (presence of an external γ irradiation source, addition of H2O2, aerated water) the spent fuel matrix alteration determined from the release of tracer elements such as Cs and Sr is always the same. Conversely, allowing for the alteration conditions (no solution renewal and no complexants), the uranium concentrations in solution do indeed depend on the oxidizing conditions as does the nature of the secondary phases liable to precipitate.
Empore™ strontium rad disks: validation procedure for strontium-90 analysis in radioactive wastes
Authors: Heynen F. , Minne E. , Hallez Ir. S.
Published: August 2007

90Sr determination in radioactive waste is currently supported by Eichrom™ Sr-spec concentration columns. This research was aimed at finding a faster and easier technique, leading to identical results. It was chosen to make use of the 3M Empore™ membranes.

It was deliberatly decided not to follow RP515 procedure (US Department of Energy).90Y will be counted by liquid scintillation after EDTA elution. Official accreditation needs to verify every validation test.

Information concerning the specificity of the membranes has been reviewed. Uncertainty calculation of the activity, as well as the detection limit, are described. The enlarged uncertainty (k= 2) reaches to about 10% for a90Sr activity of 2Bq/L. The detection limit obtained with this procedure reaches to about 50mBq/L for a sample of 0.5L and a 10h counting time. A selectivity test detects the possibility of89Sr presence which could disturb the90Sr determination. Robustness of the method is mainly assured by the use of a tracer (85Sr as in RP515). The analysis of non aqueous biological samples has been carried out for accuracy. It required an adaptation of the preparation process. Linearity was tested on a range from 0 to 18.5Bq/L90Sr. The results of 38 routine samples obtained by the Empore™ Sr Rad Disks were compared with those obtained by the Eichrom Sr-spec columns protocol. This comparison showed a good correlation between the two techniques.
Extraction of medically interesting 188Re-perrhenate in methyl ethyl ketone for concentration purposes
Authors: Mushtaq A. , Bukhari Tanveer Hussain , Khan Islam Ullah
Published: August 2007

The high bolus volumes (20–40mL) of the generator-produced Rhenium-188 require post elution concentration of the eluate for the preparation of a dissolved β− source and radiopharmaceuticals labeled with Re-188 for radiotherapy. Solvent extraction of 188Re in methyl ethyl ketone was studied. With the increase of organic phase volume, extraction of 188Re was enhanced while mixing time of aqueous and organic phases did not show any significant effect on the extractability of 188Re in the organic phase. Almost 80% of 188Re was extracted in methyl ethyl ketone at a volume ratio of 1:2 for aqueous and organic phases. By evaporation/distillation of methyl ethyl ketone, 188Re was concentrated and dissolved in the desired volume of physiological saline.
Evaluation of selectivity and radiolysis behavior of some promising isonicotinamids and dipicolinamides as extractants
Authors: Mowafy E. A.
Published: August 2007

A series of long chain isonicotinamides (pyridine-4-carboxamides) and dipicolinamides (pyridine-2,6-dicarboxamides) have been prepared with different substituting groups and the extracting ability for Fe(III), Am(III), Eu(III), Sr(II), Co(II) and Cs(I) from nitric acid solutions has been studied. Distribution ratios of Fe(III) as function of nitric acid concentration, extractants concentration and salting-out agent have been measured by usingN,N′-dioctylisonicotinamide (DOINA) andN,N,N′,N′-tetraoctyldipicolinamide (TODPA) which were chosen for further studies. Irradiation of DOINA and TOBPA by different gamma doses showed a different extraction behavior for Fe(III). The radiolytic degradation of the investigated amides has been estimated by quantitive IR spectroscopy. The results indicated that the radiolytic stability is influenced by the structure of the investigated amides. Symmetrical isonicotinamides or dipicolinamide seems to be less affected by radiation compared with unsymmetrical isonicotiniamides or dipicolinamides. The extraction of iron from aqueous solutions with the investigated extractants is fast. Separation of iron(III) based on kinetic basis was carried out.
New data on transuranium elements in the ecosystem of the Yenisei river floodplain
Authors: Bolsunovsky A. , Ermakov A. , Sobolev A.
Published: August 2007

The aim of the study is to investigate levels of transuranium elements in the ecosystem of the Yenisei river floodplain in the vicinity of the Mining-and-Chemical Combine of Rosatom. For the first time, the transuranium isotopes 243,244Cm have been detected in sediment, floodplain soil, and a berry shrub (Ribes nigrum – the blackcurrant) in the floodplain of the Yenisei river. The highest level of curium isotopes registered in the sediment of the Yenisei river is 21.4Bq/kg (dry), which is more than twice higher than maximum curium levels reported for soils sampled not far from the Chernobyl Nuclear Plant. Blackcurrant plants growing on radioactively contaminated soils contain the same transuranium elements as the soil (plutonium isotopes, americium, and curium). The highest activity concentrations of all transuranic elements have been found in ashed roots of the blackcurrant plants: 239,240Pu – 9.3Bq/kg, 241Am – 6.9Bq/kg, and 243,244Cm – 1.8Bq/kg. The highest soil-plant transfer factor (TF) for 243,244Cm is determined for roots – 0.073; the TF of 243,244Cm in berries is 0.027. The TF for 239,240Pu in berries is 0.006, which is several times lower than the TF for 243,244Cm. Analysis of our results and the literature data suggests that TFs for 243,244Cm are higher than those for 239,240Pu and 241Am.