bluuebunny/crossref_metadata_2025_split huggingface dataset:
Molecular and Supramolecular Synthesis with Dibenzofuran‐Containing Systems
Authors: Asakawa Masumi , Ashton Peter R. , Brown Christopher L. , Fyfe Matthew C. T. , Menzer Stephan , Pasini Dario , Scheuer Cecile , Spencer Neil , Stoddart J. Fraser , White Andrew J. P. , Williams David J. 
Published: July 2007

AbstractThe template‐directed syntheses of two new tetracationic cyclophanes, cyclobis(paraquat‐2,8‐dibenzofuran) and cyclobis(paraquat‐3,7‐dibenzofuran), incorporating dibenzofuran subunits has been accomplished. Initially, the cyclophanes were self‐assembled around a macrocyclic polyether template, bis‐p‐phenylene[34]crown‐10 (BPP34C10), to form catenanes: the mechanical bond order of the catenane formed determined the requisite “amacrocyclic” templates for synthesis of the free cyclophane. X‐ray crystallography shows that both of the cyclophanes possess rectangular covalent frameworks. Furthermore, these cyclophanes form self‐assembled tapes in the solid state, since the dibenzofuran moieties have a tendency to associate with each other through crossed ∞–∞ stacks. The dibenzofuran‐containing catenanes also form two‐dimensional supramolecular arrays in the solid state on account of extended ∞–∞ stacking interactions. In addition, the serendipitous discovery of a plerotopic tecton (consisting of a dibenzofuran nucleus covalently linked from the 2‐ and 8‐positions by methylene groups to 4,4′‐pyridylpyridinium (hydrogen bond acceptor) and protonated bipyridinium (hydrogen bond donor) units) has been made. The tecton dimerizes in the solid state to form a supramolecular macrocycle, since its complementary hydrogen bonding sites are oriented in a horseshoelike fashion by the 2,8‐disubstituted dibenzofuran unit. However, this superstructure is not retained in the 1:1 complex of the tecton with BPP34C10: cocrystallization of the tecton with this crown ether opens the macrocyclic two‐component supermolecule to afford a hydrogen‐bonded pseudopolyrotaxane.
Intermetallic s̀ and ∞ Communication in Heterodinuclear μ‐Cyclooctatetraene Complexes
Authors: Bögels Gerdjan , Brussaard Hugo C. , Hagenau Ute , Heck Jürgen , Kopf Jürgen , van der Linden Johannes G. M. , Roelofsen Annie 
Published: July 2007

AbstractThe reaction of [(C5R5)Cr(∞6‐Cot)] (R = H, Me; Cot = cyclooctatetraene) with [(CO)3Fe(∞‐cis‐cyclooctene)2] affords the heterodinuclear complexes [(C5R5)Cr{μ‐∞5(Cr):∞3(Fe)‐Cot}Fe(CO)3] (R = H: 1, R = Me: 2) in quite good yields. One of the CO ligands in 1 and 2 can be easily substituted by a phosphane ligand, PR3 (R = Me, Ph, OEt, F) to obtain [(C5R5)Cr{μ‐∞5(Cr):∞3(Fe)‐Cot}Fe‐(CO)2PR3] (R = H, R = Me: 3a; R = H, R = Ph: 3b; R = Me, R = Me: 4a; R = Me, R = Ph: 4b; R = Me, R = OEt: 4c; R = Me, R = F: 4d). The X‐ray structure determinations of 2, 3a, and 4c showed exclusively synfacial coordination of the two metal ligand moieties, despite the bulky C5Me5 (Cp*) ligand in 2 and 4c. However, the steric demand of Cp* gives rise to structural distortions in 2 and 4c, compared to the Cp‐containing products 1 and 3a, and an elongation of the Cr–Fe distance from 293 pm to 303 and 304 pm, respectively. The heterodinuclear complexes were investigated by cyclic voltammetry and ESR spectroscopy in order to elucidate the role of the permethylation of the cyclopentadienyl ligand and the influence of phosphane ligands with different π‐accepting abilities. The ESR spectroscopic results reveal surprisingly large 31P hyperfine coupling constants (hfcc). These can be explained by a superposition of two different electron spin transfer mechanisms, which include a s̀‐ and a π‐bonding mode between the Cr and Fe centers.
Reaction Paths for the Conversion of Methane to Methanol Catalyzed by FeO+
Authors: Yoshizawa Kazunari , Shiota Yoshihito , Yamabe Tokio 
Published: July 2007

AbstractWe propose possible theoretical reaction paths for the conversion of methane to methanol catalyzed by FeO+. The geometric and electronic structures for the reactant, product, intermediates, and transition states were calculated and analyzed in detail by means of a hybrid Hartree–Fock/density functional method. Sextet and quartet spin states were taken into consideration in the analysis of the reaction paths. The conversion of methane to methanol was shown to proceed through basic concerted hydrogen‐ and methyl‐shift reactions. A fragment molecular orbital analysis for the formation of the reactant complex, OFe+–CH4, which plays an important role in the initial stage of methane activation, was carried out in order to understand the nature of the interesting Fe–C bond. The five‐coordinate methane in the reactant complex was calculated to have a C3v‐type geometry. Each reaction path presented in this paper includes an important insertion species, HO–Fe+–CH3 or H–Fe+–OCH3, and two transition states. Thus, there are several kinds of reaction paths, if the high‐spin sextet and low‐spin quartet states are taken into consideration. A reaction towards the hydroxy intermediate, HO–Fe+–CH3, was found to be more favorable in both the sextet and quartet spin states from the viewpoint of activation energy, and this intermediate is extremely stable. It was found from intrinsic reaction coordinate (IRC) analyses that two basic reactions coexist, namely, hydrogen or methyl migration between the reactant and the methoxy intermediate, H–Fe+–OCH3. This transition state is interesting, because the two transition states resulting from C–H bond cleavage and methyl migration are located in the same region of space on the potential energy surfaces. IRCs are partially shown for the complicated first halves of the total reaction paths.
The impact of new chemotherapeutic and hormone agents on survival in a population‐based cohort of women with metastatic breast cancer
Authors: Chia Stephen K. , Speers Caroline H. , D'yachkova Yulia , Kang Anna , Malfair‐Taylor Suzanne , Barnett Jeff , Coldman Andy , Gelmon Karen A. , O'Reilly Susan E. , Olivotto Ivo A. 
Published: July 2007

AbstractBACKGROUND.Over the past decade, a number of new therapeutic agents have become available in the treatment of metastatic breast cancer (MBC). This study characterized the use and assessed the impact on survival of population‐based access to new agents for the treatment of MBC.METHODS.The dates of release in British Columbia of 7 new systemic agents for MBC during the 1990s were used to construct 4 time cohorts. All patients with a first diagnosis of distant metastases in each of the time cohorts were identified and characterized, and their survival was compared. Cox proportional regression modeling was used to assess for predictors of survival.RESULTS.In total, 2150 patients with a first distant metastases diagnosed during 1 of the 4 cohort intervals were identified. Baseline characteristics between cohorts were similar, except a greater proportion of the later cohorts received adjuvant chemotherapy (P < .001), had positive estrogen receptor status (P = .01), and had a longer median time from initial diagnosis to MBC (P < .001). Survival in Cohort 1 (1991–1992) and Cohort 2 (1994–1995; median, 438 days and 450 days, respectively) was similar. Survival was longer in Cohort 3 (1997–1998; median, 564 days; P = .002) and improved further in Cohort 4 (1999–2001; median, 667 days; P = .05). In multivariate analysis, the later cohorts were associated independently with improved survival (P = .01 and P < .001, respectively).CONCLUSIONS.Population‐based access to new therapeutic agents for MBC appeared to be associated with improved survival. To the authors' knowledge, this is the first study to date that demonstrates, from a population‐based perspective, improving survival over the past decade for women with MBC. Cancer 2007. © 2007 American Cancer Society.
Expression of erythropoietin and its receptor in neuroblastomas
Authors: Sartelet Hervé , Fabre Monique , Castaing Marine , Bosq Jacques , Racu Ivan , Lagonotte Emeryc , Scott Véronique , Lecluse Yann , Barette Stephane , Michiels Stefan , Vassal Gilles 
Published: July 2007

AbstractBACKGROUND.Children with high‐risk neuroblastomas (NB) potentially may benefit from treatment with recombinant human erythropoietin (Epo). Epo is a stimulator of erythropoiesis, acting through its receptor (EpoR). The objective of the current study was to evaluate expression levels of Epo and EpoR in NB and in normal tissues and their effects on the proliferation of tumor cells.METHODS.A tissue microarray study was performed with 101 primary tumors, 39 paired metastases, 56 paired control tissues, and 6 human NB cell lines. Immunohistochemical staining was performed using antibodies against Epo and EpoR. Immunostaining intensity was evaluated by using a semiquantitative score based on the percentage of positive cells. An in vitro analysis of cell proliferation and cell cycle in the presence of recombinant Epo was performed in the 6 cell lines.RESULTS.The expression of EpoR was found to be significantly higher in tumors than in paired control tissues (P < .0001) compared with the expression of Epo (P = .06), and the expression of EpoR was significantly higher in lymph node metastases than in paired primary tumors (P = .02) compared with Epo (P = .99). Survival analysis demonstrated that the patients who had tumors with the highest expression of EpoR had a significantly better overall survival (P = .03). In the in vitro study, recombinant Epo did not modify proliferation and cell cycle in the cell lines regardless of the EpoR expression level.CONCLUSIONS.Epo and EpoR were expressed in NB but did not modify tumor cell proliferation. The results of the current study suggested that Epo may be used safely for supportive care in children with NB. Cancer 2007. © 2007 American Cancer Society.
Garlic compounds generate reactive oxygen species leading to activation of stress kinases and cysteine proteases for apoptosis in human glioblastoma T98G and U87MG cells
Authors: Das Arabinda , Banik Naren L. , Ray Swapan K. 
Published: July 2007

AbstractBACKGROUND.Garlic‐derived organosulfur compounds such as diallyl sulfide (DAS), diallyl disulfide (DADS), and diallyl trisulfide (DATS) provide significant protection against carcinogenesis.METHODS.Dose‐dependent cytotoxic effects of the garlic compounds (DAS, DADS, and DATS) were tested in human glioblastoma T98G and U87MG cells. Wright staining and ApopTag assay confirmed induction of apoptosis. Measurements showed that production of reactive oxygen species (ROS) and an increase in intracellular free [Ca2+] promoted apoptosis. Western blot analysis indicated that increased expression and activities of the stress kinases and cysteine proteases caused apoptosis. Use of JC‐1 showed changes in mitochondrial membrane potential (Δψm) for mediation of apoptosis. Use of the specific inhibitors monitored the activation of different kinases and proteases in apoptosis.RESULTS.Treatment of glioblastoma cells with garlic compounds triggered production of ROS that induced apoptosis with the phosphorylation of p38 MAPK and activation of the redox‐sensitive JNK1 pathway. Pretreatment of cells with ascorbic acid attenuated ROS production, p38 MAPK phosphorylation, and JNK1 activation. Pretreatment with JNK1 inhibitor I also significantly reduced cell death. Increases in intracellular free [Ca2+], expression of calreticulin, and activation of caspase‐4 indicated involvement of endoplasmic reticulum (ER) stress in apoptosis. Other events in apoptosis included overexpression of Bax, down‐regulation of Bcl‐2 and some BIRC proteins, mitochondrial release of cytochrome c and Smac into the cytosol, and activation of calpain, caspase‐9, and caspase‐3.CONCLUSIONS.Garlic compounds induced apoptosis in glioblastoma cells due toproduction of ROS, increase in ER stress, decrease in Δψm, and activation of stress kinases and cysteine proteases. Cancer 2007. © 2007 American Cancer Society.
Effectiveness of sperm banking in adolescents and young adults with cancer
Authors: Neal Michael S. , Nagel Kim , Duckworth JoAnn , Bissessar Haimant , Fischer Marc A. , Portwine Carol , Tozer Richard , Barr Ronald D. 
Published: July 2007

AbstractBACKGROUND.Improving success in the treatment of cancer has resulted in an increasing number of survivors. An important quality of life issue among younger survivors is the ability to have a family. Current gonadotoxic treatments for cancer pose a challenge to future fertility. Preservation of fertility after gonadotoxic therapy is an important consideration for these patients. In a regional center, the authors evaluated efficacy and utilization of sperm banking for preservation of male fertility in adolescents and young adults (AYA) with cancer.METHODS.A retrospective chart review was conducted to obtain data on clinical features, andrology, and fertility from patients (ages < 30 years) who cryopreserved samples of semen from 1995–2005.RESULTS.Of 821 newly diagnosed male AYA cancer patients, aged 14–30 years, only 146 (17.8%) used sperm cryopreservation technology. Patients who used their cryopreserved semen for attempted conception had a 36.4% success rate with intrauterine insemination (IUI) and a 50.0% clinical pregnancy rate with in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI).CONCLUSIONS.Sperm cryopreservation by AYA males with cancer is an efficacious method for preserving future fertility. Awareness and employment of assisted reproductive technologies needs to be implemented by an interdisciplinary team of experts caring for these patients and can result in successful paternity in males after treatment for cancer. Cancer 2007. © 2007 American Cancer Society.
Effects of supportive‐expressive group therapy on survival of patients with metastatic breast cancer
Authors: Spiegel David , Butler Lisa D. , Giese‐Davis Janine , Koopman Cheryl , Miller Elaine , DiMiceli Sue , Classen Catherine C. , Fobair Patricia , Carlson Robert W. , Kraemer Helena C. 
Published: July 2007

AbstractBACKGROUND.This study was designed to replicate our earlier finding that intensive group therapy extended survival time of women with metastatic breast cancer. Subsequent findings concerning the question of whether such psychosocial support affects survival have been mixed.METHODS.One hundred twenty‐five women with confirmed metastatic (n = 122) or locally recurrent (n = 3) breast cancer were randomly assigned either to the supportive‐expressive group therapy condition (n = 64), where they received educational materials plus weekly supportive‐expressive group therapy, or to the control condition (n = 61), where they received only educational materials for a minimum of 1 year. The treatment, 90 minutes once a week, was designed to build new bonds of social support, encourage expression of emotion, deal with fears of dying and death, help restructure life priorities, improve communication with family members and healthcare professionals, and enhance control of pain and anxiety.RESULTS.Overall mortality after 14 years was 86%; median survival time was 32.8 months. No overall statistically significant effect of treatment on survival was found for treatment (median, 30.7 months) compared with control (median, 33.3 months) patients, but there was a statistically significant intervention site‐by‐condition interaction. Exploratory moderator analysis to explain that interaction revealed a significant overall interaction between estrogen‐receptor (ER) status and treatment condition (P= .002) such that among the 25 ER‐negative participants, those randomized to treatment survived longer (median, 29.8 months) than ER‐negative controls (median, 9.3 months), whereas the ER‐positive participants showed no treatment effect.CONCLUSIONS.The earlier finding that longer survival was associated with supportive‐expressive group therapy was not replicated. Although it is possible that psychosocial effects on survival are relevant to a small subsample of women who are more refractory to current hormonal treatments, further research is required to investigate subgroup differences. Cancer 2007. © 2007 American Cancer Society.
Quenching and Recoupling of Echo Modulations in NMR Spectroscopy
Authors: Gopalakrishnan Karthik , Aeby Nicolas , Bodenhausen Geoffrey 
Published: July 2007

AbstractTrains of spin echoes are normally modulated by homonuclear scalar couplings. It has long been known that echo modulations are quenched when the pulse‐repetition rates are much larger than the offsets of the coupling partners, because the spin systems behave as if they consisted of magnetically equivalent spins when the offsets are suppressed. This type of quenching of the echo modulations can occur when the radio‐frequency (RF) pulses are ideal, that is, when they are perfectly homogeneous, properly calibrated to induce rotations through an angle,π, and have an RF amplitude,ω1=−γB1, that is strong compared to the largest offset,ΩS=ω0S−ωRF, with respect to the carrier frequency. Recently, it was discovered that echo modulations can also be quenched when the RF pulses are nonideal, that is, when they are too weak to bring about an ideal rotation of the magnetization of the coupling partners, so that the effective fields associated with the RF pulses are tilted in the rotating frame. This phenomenon typically occurs when the pulse‐repetition rates are much slower than the offset of the coupling partner. Under such conditions, it turns out, however, that for certain offsets, when the phase,ΦS(which arises from a free precession of the magnetization of the coupling partner,S, in the pulse interval, 2τ, and the pulse length,τπ),approaches a multiple of 2π, the echo modulations are restored. However, the frequencies of these echo modulations are not simply determined by the homonuclear scalar coupling,JIS. The Fourier transforms of the echo trains (the so‐called “Jspectra”) reveal surprising multiplet patterns, and the amplitudes of the echo modulations depend on the offsets of the coupling partners. Herein, we present a unified theory, based on an average‐Hamiltonian approach, to describe these effects for two‐spin systems. Experimental evidence of echo modulations in a system of two spins is presented. Experiments with three and more spins, backed up by extensive numerical simulations, will be presented elsewhere.
Dichotic listening deficits in children with dyslexia
Authors: Moncrieff Deborah W. , Black Jeffrey R. 
Published: July 2007

AbstractSeveral auditory processing deficits have been reported in children with dyslexia. In order to assess for the presence of a binaural integration type of auditory processing deficit, dichotic listening tests with digits, words and consonant–vowel (CV) pairs were administered to two groups of right‐handed 11‐year‐old children, one group diagnosed with developmental dyslexia and an age‐matched control group. Dyslexic children performed more poorly than controls from their left ears when listening to digits and words and from their right ears when listening to CVs. Direction of ear advantage varied across individuals in both groups when tested with digits and CVs, but ear advantage was stable with words. Several factors that may have contributed to inconsistencies in direction of ear advantage are discussed. When the children were tested in a directed response mode, degree of ear advantage differed significantly between groups with both words and digits. More dyslexic than control children demonstrated clinically significant reductions in dichotic listening performance, but no uniform pattern of deficit emerged. Only the double correct score and the left ear score with CV pairs were predictive of word recognition performance in dyslexic children. Binaural integration deficits are present in some children with dyslexia. Auditory processing disorder assessment may help delineate factors that underlie or are associated with reading impairment in this population. Copyright © 2007 John Wiley & Sons, Ltd.
Baclofen for binge eating: An open‐label trial
Authors: Broft Allegra I. , Spanos Alexia , Corwin Rebecca L. , Mayer Laurel , Steinglass Joanna , Devlin Michael J. , Attia Evelyn , Walsh B. Timothy 
Published: July 2007

AbstractObjective:Baclofen is a GABA‐B agonist that may be useful in the treatment of substance use disorders, and also reduces ‘binge‐like’ eating in rodents. We hypothesized that baclofen might be effective in reducing binge eating episodes in binge eating disorder (BED) and bulimia nervosa (BN).Method:Seven women with BED (n = 4) or BN (n = 3) took baclofen (60 mg/day) for 10 weeks.Results:Six out of seven patients completed the full 10‐week trial. Five out of seven participants (3 BED; 2 BN) demonstrated 50% or greater reduction of frequency of binge eating from beginning to end of the study. Three out of seven participants (2 BED; 1 BN) were free of binge eating at study end. Four out of seven participants elected to continue baclofen at study end. Baclofen was well tolerated by the participants.Conclusion:In this open‐label trial, baclofen was associated with decreased binge eating frequency in patients with BED and BN. © 2007 by Wiley Periodicals, Inc. Int J Eat Disord 2007
System simulator for structural description and error analysis of multimodal 3D data integration systems
Authors: Sakuragi Futoshi , Nakamoto Masahiko , Sasama Toshihiko , Nakajima Yoshikazu , Sato Yoshinobu , Tamura Shinichi 
Published: July 2007

AbstractIn surgical navigation systems, system error analysis is performed because of the need for correct superposition of three‐dimensional data obtained with three‐dimensional position sensors and different coordinate systems for the images. Lea and colleagues proposed a registration graph for providing a systematic description with a graph of the geometrical position of the system and performing error analysis. However, the registration graph requires the explicit input of errors for each 3D data item. The authors expanded this system to automatically calculate individually occurring errors from system design information through a simulation, and to perform direct error analysis from the system design information. As a result, a user without specialized knowledge of error analysis can automatically perform error analysis by virtually designing a 3D data integration system on a computer. In this paper, the authors constructed a system simulator for modeling point‐to‐point registration and 3D position sensors, performing automatic error calculation with the simulation based thereon, and designing a system easily using a GUI. Furthermore, as a demonstration of the simulator, the simulator was applied to error analysis for a system including point‐to‐point registration and 3D position sensors, and its effectiveness and reliability were confirmed. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 90(8): 45–59, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.20377
Design and Synthesis of a Tag‐Free Chemical Probe for Photoaffinity Labeling
Authors: Mayer Timo , Maier Martin E. 
Published: July 2007

AbstractThe novel aromatic diazirine‐containing benzoic acid 22 was prepared via the diazirine 11 as the key intermediate. After formylation of the aryl ring and cleavage of the methyl ether function of aldehyde 12, the phenolic hydroxy group was converted into the ether 21 terminating in an alkyne function. Oxidation of the aldehyde to the carboxylic acid provided the chemical probe 22 designed for tag‐free photoaffinity labeling. In a proof‐of‐concept study it could be shown that irradiation of the simple ester 23 indeed yields the methanol insertion product 24. A subsequent click reaction with benzyl azide 20 led to the triazole 25. A more complicated example was realized with the esterification of bafilomycin A1 (27) with acid 22. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)