bluuebunny/crossref_metadata_2025 huggingface dataset:
Improved variance estimation of classification performance via reduction of bias caused by small sample size
Authors: Wickenberg-Bolin Ulrika , Göransson Hanna , Fryknäs Mårten , Gustafsson Mats G , Isaksson Anders
Published: March 2006

Background

Supervised learning for classification of cancer employs a set of design examples to learn how to discriminate between tumors. In practice it is crucial to confirm that the classifier is robust with good generalization performance to new examples, or at least that it performs better than random guessing. A suggested alternative is to obtain a confidence interval of the error rate using repeated design and test sets selected from available examples. However, it is known that even in the ideal situation of repeated designs and tests with completely novel samples in each cycle, a small test set size leads to a large bias in the estimate of the true variance between design sets. Therefore different methods for small sample performance estimation such as a recently proposed procedure called Repeated Random Sampling (RSS) is also expected to result in heavily biased estimates, which in turn translates into biased confidence intervals. Here we explore such biases and develop a refined algorithm called Repeated Independent Design and Test (RIDT).

Results

Our simulations reveal that repeated designs and tests based on resampling in a fixed bag of samples yield a biased variance estimate. We also demonstrate that it is possible to obtain an improved variance estimate by means of a procedure that explicitly models how this bias depends on the number of samples used for testing. For the special case of repeated designs and tests using new samples for each design and test, we present an exact analytical expression for how the expected value of the bias decreases with the size of the test set.

Conclusion

We show that via modeling and subsequent reduction of the small sample bias, it is possible to obtain an improved estimate of the variance of classifier performance between design sets. However, the uncertainty of the variance estimate is large in the simulations performed indicating that the method in its present form cannot be directly applied to small data sets.
Network-level analysis of metabolic regulation in the human red blood cell using random sampling and singular value decomposition
Authors: Barrett Christian L , Price Nathan D , Palsson Bernhard O
Published: March 2006

Background

Extreme pathways (ExPas) have been shown to be valuable for studying the functions and capabilities of metabolic networks through characterization of the null space of the stoichiometric matrix (S). Singular value decomposition (SVD) of the ExPa matrix P has previously been used to characterize the metabolic regulatory problem in the human red blood cell (hRBC) from a network perspective. The calculation of ExPas is NP-hard, and for genome-scale networks the computation of ExPas has proven to be infeasible. Therefore an alternative approach is needed to reveal regulatory properties of steady state solution spaces of genome-scale stoichiometric matrices.

Results

We show that the SVD of a matrix (W) formed of random samples from the steady-state solution space of the hRBC metabolic network gives similar insights into the regulatory properties of the network as was obtained with SVD of P. This new approach has two main advantages. First, it works with a direct representation of the shape of the metabolic solution space without the confounding factor of a non-uniform distribution of the extreme pathways and second, the SVD procedure can be applied to a very large number of samples, such as will be produced from genome-scale networks.

Conclusion

These results show that we are now in a position to study the network aspects of the regulatory problem in genome-scale metabolic networks through the use of random sampling.

Contact: palsson@ucsd.edu
Identification of rat lung – prominent genes by a parallel DNA microarray hybridization
Authors: Chen Zhongming , Chen Jiwang , Weng Tingting , Jin Nili , Liu Lin
Published: March 2006

Background

The comparison of organ transcriptomes is an important strategy for understanding gene functions. In the present study, we attempted to identify lung-prominent genes by comparing the normal transcriptomes of rat lung, heart, kidney, liver, spleen, and brain. To increase the efficiency and reproducibility, we first developed a novel parallel hybridization system, in which 6 samples could be hybridized onto a single slide at the same time.

Results

We identified the genes prominently expressed in the lung (147) or co-expressed in lung-heart (23), lung-liver (37), lung-spleen (203), and lung-kidney (98). The known functions of the lung-prominent genes mainly fell into 5 categories: ligand binding, signal transducer, cell communication, development, and metabolism. Real-time PCR confirmed 13 lung-prominent genes, including 5 genes that have not been investigated in the lung, vitamin D-dependent calcium binding protein (Calb3), mitogen activated protein kinase 13 (Mapk13), solute carrier family 29 transporters, member 1 (Slc29a1), corticotropin releasing hormone receptor (Crhr1), and lipocalin 2 (Lcn2).

Conclusion

The lung-prominent genes identified in this study may provide an important clue for further investigation of pulmonary functions.
NovelFam3000 – Uncharacterized human protein domains conserved across model organisms
Authors: Kemmer Danielle , Podowski Raf M , Arenillas David , Lim Jonathan , Hodges Emily , Roth Peggy , Sonnhammer Erik LL , Höög Christer , Wasserman Wyeth W
Published: March 2006

Background

Despite significant efforts from the research community, an extensive portion of the proteins encoded by human genes lack an assigned cellular function. Most metazoan proteins are composed of structural and/or functional domains, of which many appear in multiple proteins. Once a domain is characterized in one protein, the presence of a similar sequence in an uncharacterized protein serves as a basis for inference of function. Thus knowledge of a domain's function, or the protein within which it arises, can facilitate the analysis of an entire set of proteins.

Description

From the Pfam domain database, we extracted uncharacterized protein domains represented in proteins from humans, worms, and flies. A data centre was created to facilitate the analysis of the uncharacterized domain-containing proteins. The centre both provides researchers with links to dispersed internet resources containing gene-specific experimental data and enables them to post relevant experimental results or comments. For each human gene in the system, a characterization score is posted, allowing users to track the progress of characterization over time or to identify for study uncharacterized domains in well-characterized genes. As a test of the system, a subset of 39 domains was selected for analysis and the experimental results posted to the NovelFam3000 system. For 25 human protein members of these 39 domain families, detailed sub-cellular localizations were determined. Specific observations are presented based on the analysis of the integrated information provided through the online NovelFam3000 system.

Conclusion

Consistent experimental results between multiple members of a domain family allow for inferences of the domain's functional role. We unite bioinformatics resources and experimental data in order to accelerate the functional characterization of scarcely annotated domain families.
Injuries in Aleppo, Syria; first population-based estimates and characterization of predominant types
Authors: Maziak Wasim , Ward Kenneth D , Rastam Samer
Published: March 2006

Background

Despite the growing burden of injuries worldwide, Syria and many other Arab countries still lack population-based estimates of different types of injuries. This study aims toprovide first population-based estimates of major injuries in Syria and characterize groups at increased risk.

Methods

An interviewer-administered population-based survey of adults 18–65 years residing in Aleppo, Syria was conducted in 2004. The study sample involved 2038 household representatives in Aleppo (45.2% men, mean age 35.3 ± 12.1, response rate 86%). We inquired about participants self-reported injuries in the past year that required medical attention as well as injuries among their household members. When reported, injuries were further assessed according to type, place, and outcome.

Results

Overall, there was 153 self-reported injuries in the past year (77.3 per 1000 adult respondents, 93.1 per 1000 in men and 64.4 per 1000 in women, p = 0.02). Other than gender, injuries differed by age (the older age group being least affected), and place of occurrence, as men were more likely to sustain traffic injuries and be injured outside the home. Injuries were reported among 236 household members (21.0 per 1000), and were slightly more frequent in children than adults (22.0 per 1000 for children, and 19.7 per 1000 for adults, p = 0.2). Traffic injuries, falls, and poisoning (food) were by far the most common types of injury experienced by participants as well as their household members. Falls and traffic injuries seem to have caused most morbidity for the injured, while burns, although not frequently reported, were associated with an unfavorable outcome in the majority of cases.

Conclusion

This information provides baseline information about the burden of different injuries in Syria, and the sociodemographic factors related to them.
A heart failure self-management program for patients of all literacy levels: A randomized, controlled trial [ISRCTN11535170]
Authors: DeWalt Darren A , Malone Robert M , Bryant Mary E , Kosnar Margaret C , Corr Kelly E , Rothman Russell L , Sueta Carla A , Pignone Michael P
Published: March 2006

Background

Self-management programs for patients with heart failure can reduce hospitalizations and mortality. However, no programs have analyzed their usefulness for patients with low literacy. We compared the efficacy of a heart failure self-management program designed for patients with low literacy versus usual care.

Methods

We performed a 12-month randomized controlled trial. From November 2001 to April 2003, we enrolled participants aged 30–80, who had heart failure and took furosemide. Intervention patients received education on self-care emphasizing daily weight measurement, diuretic dose self-adjustment, and symptom recognition and response. Picture-based educational materials, a digital scale, and scheduled telephone follow-up were provided to reinforce adherence. Control patients received a generic heart failure brochure and usual care. Primary outcomes were combined hospitalization or death, and heart failure-related quality of life.

Results

123 patients (64 control, 59 intervention) participated; 41% had inadequate literacy. Patients in the intervention group had a lower rate of hospitalization or death (crude incidence rate ratio (IRR) = 0.69; CI 0.4, 1.2; adjusted IRR = 0.53; CI 0.32, 0.89). This difference was larger for patients with low literacy (IRR = 0.39; CI 0.16, 0.91) than for higher literacy (IRR = 0.56; CI 0.3, 1.04), but the interaction was not statistically significant. At 12 months, more patients in the intervention group reported monitoring weights daily (79% vs. 29%, p < 0.0001). After adjusting for baseline demographic and treatment differences, we found no difference in heart failure-related quality of life at 12 months (difference = -2; CI -5, +9).

Conclusion

A primary care-based heart failure self-management program designed for patients with low literacy reduces the risk of hospitalizations or death.
Identifying patients at risk of nursing home admission: The Leeds Elderly Assessment Dependency Screening tool (LEADS)
Authors: Slade Anita , Fear Jon , Tennant Alan
Published: March 2006

Background

Discharge from hospital to a nursing home represents a major event in the life of an older person and should only follow a comprehensive functional and medical assessment. A previous study identified 3 dependency scales able to discriminate across outcomes for older people admitted to an acute setting. We wished to determine if a single dependency scale derived from the 3 scales could be created. In addition could this new scale with other predictors be used as a comprehensive tool to identify patients at risk of nursing home admission.

Methods

Items from the 3 scales were combined and analysed using Rasch Analysis. Sensitivity and specificity analysis and ROC curves were applied to identify the most appropriate cut score. Binary logistic regression using this cut-off, and other predictive variables, were used to create a predictive algorithm score. Sensitivity, specificity and likelihood ratio scores of the algorithm scores were used to identify the best predictive score for risk of nursing home placement.

Results

A 17-item (LEADS) scale was derived, which together with four other indicators, had a sensitivity of 88% for patients at risk of nursing home placement, and a specificity of 85% for not needing a nursing home placement, within 2 weeks of admission.

Conclusion

A combined short 17-item scale of dependency plus other predictive variables can assess the risk of nursing home placement for older people in an acute care setting within 2 weeks of admission. This gives an opportunity for either early discharge planning, or therapeutic intervention to offset the risk of placement.
Prevalence of self-reported hypercholesterolaemia and its relation to dietary habits, in Greek adults; a national nutrition & health survey
Authors: Milias George A , Panagiotakos Demosthenes B , Pitsavos Christos , Xenaki Dimitra , Panagopoulos George , Stefanadis Christodoulos
Published: March 2006

Background

The strong causal role of hypercholesterolaemia on the progression of atherosclerosis and subsequently on the development of cardiovascular disease is well described. Main aim of this study was to evaluate the prevalence of self-reported hypercholesterolaemia and its relation to nutritional habits, in a representative nationwide sample of adult Greek population.

Methods

Cross sectional survey. Based on a multistage sampling, 5003 adults (18 – 74 yr) were enrolled (men: 48.8%, women: 51.2%). All participants were interviewed by trained personnel who used a standard questionnaire. The questionnaire included demographic and socioeconomic characteristics, medical history, lifestyle habits and nutritional assessment.

Results

The prevalence of self-reported hypercholesterolaemia was 16.4% in men and 21.8% in women (P < 0.001). Hypercholesterolaemic status was positively associated with the prevalence of hypertension, diabetes mellitus, renal failure, obesity and physical inactivity, and inversely with the prevalence of smoking. The analysis of reported food consumption patterns showed that consumption of fish, fruits and juices, cereals, and low fat milk and yogurt was significantly higher among hypercholesterolaemic participants while the opposite was observed for food items as red meat, pork, egg, full fat dairy products and desserts.

Conclusion

Hypercholesterolaemia seems to affect a large part of Greek population. It is hopeful that hypercholesterolaemics may have started adopting some more healthy nutritional behaviour compared to normocholesterolaemic ones.
Sib-recruitment for studying migration and its impact on obesity and diabetes
Authors: Lyngdoh Tanica , Kinra Sanjay , Shlomo Yoav Ben , Reddy Srinath , Prabhakaran Dorairaj , Smith George Davey , Ebrahim Shah ,   the Indian migration study group
Published: March 2006

Background

Urban-rural comparisons are of limited relevance in examining the effects of urban migration in developing countries where urbanisation is due to growth of existing urban populations, expansion of urban boundaries, and rural in-migration. Cultural, genetic and life-style backgrounds of migrants and host populations further limit the value of rural-urban comparisons. Therefore we evaluated a sib-comparison design intended to overcome the limitations of urban-rural comparisons.

Methods

Using the framework of a current cardiovascular risk factor screening study conducted in Indian factories, we recruited the non-migrant rural sibs of migrant urban factory workers and the urban sibs of non-migrant factory workers. The response rate, completed interviews and examinations conducted were assessed. Adequacy of generic food frequency questionnaires and WHO quality of life questionnaire were assessed.

Results

All the urban factory workers and spouses approached agreed to be interviewed. Of the 697 participants interviewed, 293 (42%) had at least one rural dwelling sibling. Twenty (22%) siblings lived further than 100 km from the study site. An additional 21 urban siblings of non-migrant factory workers were also investigated to test the logistics of this element of the study. Obesity (BMI >25 kg/m2) was more common in rural sibs than urban factory workers (age adjusted prevalence: 21.1% (17.1 to 25.0) vs. 16.1% (11.9, 20.3). Diabetes prevalence (fasting plasma glucose greater than 126 mg/dl) was higher than expected (age-adjusted prevalence: 12.5% (22 out of 93) in urban migrants and 4.5% (8 out of 90) in rural non-migrant sibs.

Conclusion

The sib-comparison design is robust and has been adopted in the main study. It is possible that simple urban-rural study designs under-estimate the true differences in diabetes risk between migrants and non-migrants.
Docetaxel, Cisplatin, and Trastuzumab As Primary Systemic Therapy for Human Epidermal Growth Factor Receptor 2–Positive Locally Advanced Breast Cancer
Authors: Hurley Judith , Doliny Philomena , Reis Isildinha , Silva Orlando , Gomez-Fernandez Carmen , Velez Pedro , Pauletti Giovanni , Powell Jodeen E. , Pegram Mark D. , Slamon Dennis J.
Published: March 2006

Purpose

To evaluate the efficacy and safety of docetaxel, cisplatin, and trastuzumab as primary systemic therapy for human epidermal growth factor receptor 2 (HER2) –positive, locally advanced breast cancer (LABC).

Patients and Methods

Forty-eight patients with immunohistochemistry-confirmed HER2-positive LABC or inflammatory breast cancer received 12 weeks of docetaxel, cisplatin, and trastuzumab with filgrastim, followed by surgery, adjuvant doxorubicin and cyclophosphamide, and locoregional radiotherapy with or without tamoxifen. The primary end point was pathologic complete response (pCR) in breast.

Results

Baseline mean tumor size was 9.2 cm (range, 4 to 32 cm). pCR occurred in breast in 11 patients (23%; 95% CI, 12% to 37%) and breast and axilla in eight patients (17%; 95% CI, 8% to 30%). pCR rates in breast (HER2 positive, seven of 30 patients, 23% v HER2 negative, four of 18 patients, 22%; P > .05) and breast and axilla (four of 30 patients, 13% v four of 18 patients, 22%, respectively; P > .05) were similar regardless of HER2 status by fluorescence in situ hybridization (FISH). At a median follow-up time of 43 months, 4-year progression-free survival (PFS) rate was 81% (95% CI, 64% to 90%); overall survival (OS) rate was 86% (95% CI, 71% to 94%). In patients with pCR in breast and axilla, PFS and OS rates were 100% (95% CI, inestimable). In patients without pCR, PFS rate was 76% (95% CI, 57% to 88%; P = .15, log-rank test), and OS rate was 83% (95% CI, 66% to 92%; P = .21). Survival rates were similar regardless of FISH status. There were only two grade 4 adverse events.

Conclusion

Twelve weeks of docetaxel, cisplatin, and trastuzumab is clinically active and leads to excellent survival in patients with large, HER2-positive tumors.
Tumor Transcriptome Reveals the Predictive and Prognostic Impact of Lysosomal Protease Inhibitors in Non–Small-Cell Lung Cancer
Authors: Petty Russell D. , Kerr Keith M. , Murray Graeme I. , Nicolson Marianne C. , Rooney Patrick H. , Bissett Donald , Collie-Duguid Elaina S.R.
Published: March 2006

Purpose

Insight into clinical response to platinum-based chemotherapy (PBC) in non–small-cell lung cancer (NSCLC).

Methods

Matched tumor and nontumor lung tissues from PBC-treated NSCLC patients (four nonresponders and four responders) and tumor tissue from an independent test set (four nonresponders and four responders), were profiled using microarrays. Lysosomal protease inhibitors SerpinB3 and cystatin C were highly correlated with clinical response and were further evaluated by immunohistochemistry in PBC-treated patients (36 prechemotherapy and 13 postchemotherapy). Investigation of the pathogenic and prognostic significance of SerpinB3 was performed in 251 primary tumors, with 64 regional lymph node pairs, from chemotherapy-naïve NSCLC patients using immunohistochemistry.

Results

Bioinformatic analyses of gene expression in the training set identified a gene set (n = 17) that separated all patients in the training and test sets (n = 16) according to response in hierarchical clustering. Transcriptome profiling revealed that SerpinB3 mRNA was highly correlated with degree of response (r = −0.978; P < .0001) and was a clear outlier (nonresponders:responders > 50-fold). SerpinB3 protein expression was correlated with clinical response in PBC-treated NSCLC patients (P = .045). Expression of SerpinB3 and cystatin C, relative to the target, protease cathepsin B, was independently predictive of response (odds ratio, 17.8; 95% CI, 2.0 to 162.4; P = .01), with an accuracy of 72%. High SerpinB3 expression levels, invariably associated with chemoresistance, had contrasting prognostic impact in untreated squamous cell carcinomas (hazard ratio [HR], 0.43; 95% CI, 0.18 to 0.93) or adenocarcinomas (HR, 2.09; 95% CI, 1.03 to 4.72).

Conclusion

This provides the first comprehensive molecular characterization of clinical responsiveness to PBC in NSCLC and reveals the predictive and prognostic impact of two lysosomal protease inhibitors, potentially representing novel targets for NSCLC therapeutics.
Influence of Oxygen on Detection of Nitrogen Oxides with Solid Electrolyte Sensor Using NaNO3
Authors: Yao Sheng , Shimizu Youichi , Miura Norio , Yamazoe Noboru
Published: March 2006

The solid electrolyte sensor device using a sodium ionic conductor and NaNO3 (auxiliary phase) was found to exhibit a remarkable feature that its EMF response to NO2 is totally independent of the concentration of coexisting oxygen. The response to NO, however, was seriously affected by the presence and absence of O2, suggesting the oxidation of NO to NO2 prior to being sensed. In the absence of NOx, the sensor EMF changed with changing oxygen concentration following the Nernst’s equation for a 2-electron reaction of O2.
Catalysis by Rhodium and Iridium Complexes in the Nucleophilic Addition of Allylic Stannanes to Carbonyl Compounds
Authors: Nuss John M , Rennels Roger A
Published: March 2006

The catalysis of the nucleophilic addition of an allylic stannane to aromatic aldehydes by cationic rhodium and iridium complexes is described. The scope, generality, and several mechanistic speculations concerning this process are discussed. Initial attempts at utilizing optically active catalysts for the enantioselective addition of allyltributyltin to benzaldehyde are also outlined.
Synthesis of Oligoribonucleotides Bearing Morpholino-Nucleosides with Carbamate Internucleoside Linkages at the 3′-Terminus
Authors: Sakatsume Osamu , Tanaka Hiroaki , Takaku Hiroshi
Published: March 2006

Oligoribonucleotides containing morpholino-nucleosides with carbamate internucleoside linkages at the 3′-terminus were synthesized by the solid phase method. These analogues were examined for stability in a prokaryotic cell-free system.
Cation-π Interactions in Calix[4]arene-based Host Molecules. What Kind of Cavity-shape ls Favored for the Cation-binding?
Authors: Araki Koji , Shimizu Hiroyasu , Shinkai Seiji
Published: March 2006

The cation-π interaction was studied using 9 calix[n]arenes with the different cavity size and the different cavity shape: the efficient binding of N-methylpyridinium iodide was observed for calix[6]arenes among calix[n]arenes and for cone isomers among calix[4]arene conformers, indicating the importance of the host-guest-type cation inclusion in the π-base cavities.
An Unusual Suppression of Trimethylamine Formation in the High Temperature Alkylation of Ammonia with Methanol over (NH4)3PW12O40
Authors: Nasikin Mohammad , Nakamura Ryuichi , Niiyama Hiroo
Published: March 2006

A synthesis of methylamines from ammonia and methanol was studied by using mainly the title heteropoly catalyst. Although at low temperatures below ca. 750 K the three methylamines (MMA, DMA, and TMA) were formed as usual, at higher temperatures the formation of TMA was completely suppressed. This unusual product selectivity was explained by the strong adsoption of TMA to the catalyst.
Regulation of Diastereofacial Selection in the Allylation Reaction of N-Acyliminium Ion Utilizing Lewis Acids
Authors: Ukaji Yutaka , Tsukamoto Kouji , Nasada Yasunori , Shimizu Makoto , Fujisawa Tamotsu
Published: March 2006

Diastereofacial selectivity in the α-allylation reaction of chiral cyclic α-acyloxy amide, derived from succinic anhydride and (R)-2-methoxy-1-phenylethylamine could be regulated using appropriately selected Lewis acids; i.e., the reaction using Lewis acids such as TiCl4 gave (R,S)-α-allylated amides, while allylation promoted by SnCl4 afforded (R,R)-isomers stereoselectively. The similar result was obtained in the reaction of chiral amide prepared from phthalic anhydride.
Selective Reduction of Nitrogen Monoxide with Methane or Ethane on Gallium Ion-exchanged ZSM-5 in Oxygen-rich Atmosphere
Authors: Yogo Katsunori , Ihara Michito , Terasaki Ikue , Kikuchi Eiichi
Published: March 2006

Selective reduction of nitric oxide with methane or ethane in the presence of excess oxygen was investigated using a gallium ion-exchanged ZSM-5 zeolite catalyst(Ga-ZSM-5). Ga-ZSM-5 was highly active and selective for NO reduction above 400 °C. The limiting molar ratios of reacted NO to consumed carbon in C2H6 and CH4 at 500 °C were found to be 1.5 and 2, respectively.
Acyclic 1,2-Asymmetric Induction in Addition Reactions of Alkyl Radicals to Chiral Olefins
Authors: Morikawa Tsutomu , Washio Yoshiaki , Shiro Motoo , Taguchi Takeo
Published: March 2006

Addition reactions of alkyl radicals to chiral (Z)-α,β-unsaturated ester derivatives obtained from (R)-2,3-O-isopropylidene glyceraldehyde proceeded with high stereoselectivity (1,2-asymmetric induction).
Enantioselective Production of (S)-3-Hydroxybutyric Acid, (S)-1,3-Butanediol and (R)-1,3-Butanediol Using Methanol Yeast
Authors: Matsumura Shuichi , Imafuku Hiroshi , Takahashi Yoshinori , Toshima Kazunobu
Published: March 2006

(S)-3-Hydroxybutyric acid and (S)-1,3-butanediol were obtained by the treatment of 1,3-butanediol with the resting cells of methanol yeast, Candida boidinii (IFO 10574). (R)-1,3-Butanediol was also obtained in high optical purity by the enantioselective reduction of 4-hydroxy-2-butanone in the presence of methanol using the same methanol yeast.
Fe(CO)5/Sulfur-Catalyzed Liquefaction of Yallourn Coal in Syngas-Water Systems
Authors: Watanabe Yoshihisa , Yamada Hiro-aki , Kawasaki Nori-aki , Wada Kenji , Hata Kazu-aki , Mitsudo Take-aki
Published: March 2006

Pentacarbonyliron with sulfur was found to be an excellent catalyst precursor for liquefaction of Yallourn coal using syngas-water as a hydrogen source. Both the high coal conversion and well-balanced consumption of syngas were achieved by controlling the amount of water. The two-staged reaction at 375 °C for 1 h and then at 425 °C for 1 h showed high coal conversion of 96.7% with high oil yield.
Properties of Alkali-Ion-Exchanged Glass Optical Waveguides. Optical Sensitivity of Monitoring Chemical Species at Surface
Authors: Itoh Kiminori , Murabayashi Masayuki , Yamazaki Kazuki , Fujishima Akira
Published: March 2006

Glass optical waveguides (OWGs) doped with alkali ions were examined mainly in terms of optical sensitivity of monitoring surface chemical species located at surfaces. The maximum sensitivity (per 1 cm optical path length) for K+-doped glass OWGs was ca. 50 times as large as that of conventional optical measurements with normal incidence of monitoring light. Rb+-doped and Cs+-doped OWGs had higher sensitivities, but they showed rather large attenuation of the guided light.
3-Benzyl-5-(4-hydroxyphenyl)-2-[4-(1-azi-2,2,2-trifluoroethyl)phenylacetamido]pyrazine, a Photoreactive Analogue of Coelenteramide. Synthesis and Photolysis
Authors: Chen Feng Qi , Hirano Takashi , Ohashi Mamoru , Nakayama Hitoshi , Oda Kazuaki , Machida Minoru
Published: March 2006

A photoreactive analogue of coelenteramide (light emitting species in aequorin bioluminescence) has been synthesized for photoaffinity labeling studies of aequorin. Photolysis of this compound in methanol gave a formal OH insertion product in 62% yield without damage of the main skeleton of coelenteramide, indicating a potential use for mapping the coelenterazine binding site in aequorin.
Preparation of a Multilayered Film of Ultrathin Poly(tetraallylammonium bromide) Network
Authors: Marek Miroslav , Fukuta Kenji , Kunitake Toyoki
Published: March 2006

A multilayered film of two-dimensionally cross linked poly(tetraallylammonium bromide) was prepared using a cast film of bilayers of a double-chain ammonium amphiphile as template. This film displayed unique electrochemical properties.
Heat-Induced Structural Changes of Multibilayer Films of Benzylideneaniline- and Salicylideneaniline-Containing Ammonium Amphiphiles
Authors: Nishimi Taisei , Ishikawa Yuichi , Kunitake Toyoki , Sekita Mari , Xu Guiqint , Okuyama Kenji
Published: March 2006

Cast films prepared from benzylideneaniline- and salicylideneaniline-containing ammonium amphiphiles at room temperature possess interdigitated bilayer structures. These molecular assemblies show various types of crystalline modifications above their transition temperatures.
Synthesis of a New Rigid Quinone-Amino Acid and Diels-Alder Extension to Higher Quinones
Authors: Kotha Sambasivarao , Kuki Atsuo
Published: March 2006

Electron deficient cyclic α-amino acid derivatives bearing 1,4-benzoquinone and 1,4-anthraquinone side chains were synthesized by a novel route. The common precursor, 2-amino-4,7-dimethoxy-indan-2-carboxylic acid, may be incorporated into a peptide prior to the final oxidation and annelation reactions.
Selective Preparation of Substituted Maltooligosaccharides through Enzymatic Hydrolysis of Substituted β-Cyclodextrins by Bacterial α-Amylase (Saccharifying Type). A Novel Method for Determining Regiochemical Structure of Disubstituted β-Cyclodextrin
Authors: Fujtta Kahee , Ohta Kazuko , Okabe Yuji , Ishizu Takashi , Yamamoto Takehiko , Minamiura Noshi , Pitha Josef
Published: March 2006

Specifically substituted maltooligosaccharides were prepared through the enzymatic hydrolysis of β-cyclodextrin derivatives by bacterial α-amylase (saccharifying type).
On-line HPLC Determination of Enzymatic Activity of Alkaline Phosphatase in Natural Water Using Spectrofluorometric Detection
Authors: Hirose Akio , Esaka Yukihiro , Ohta Michiru , Haraguchi Hiroki
Published: March 2006

Fundamental studies on the on-line HPLC detection of enzymatic activity of alkaline phosphatase (APase) has been examined, where 4-methylumbelliferyl phosphate was used as a substrate. The technique developed was applied to detection of APase in natural water.
Observation of the Infrared and Raman Spectra of p-Benzoquinodimethane in Low-Temperature Ar Matrices
Authors: Yamakita Yoshihiro , Furukawa Yukio , Tasumi Mitsuo
Published: March 2006

The infrared and Raman spectra of p-benzoquinodimethane have been observed in low-temperature Ar matrices. The infrared spectrum obtained has proved to be more reliable and useful than the existing numerical data on the absorption wavenumbers and qualitative intensities. The Raman spectrum has been observed for the first time. Vibrational assignments of bands characteristic of this quinoid molecule are discussed on an experimental basis.
Effects of Potassium Hexacyanoferrate(II) on Electroless Copper Plating in the Presence of Excess 2,2′,2″-Nitrilotriethanol
Authors: Kondo Koji , Kojima Katsuaki , Ishida Nobumasa , Irie Masahiro
Published: March 2006

With the addition of potassium hexacyanoferrate(II) to the 2,2′2″-nitrilotriethanol (TEA) electroless copper bath, the effects of the plating rate and the deposit quality were examined. The required concentration to improve the quality of the TEA bath was 10 times higher than that in the ethylenediaminetetraacetic acid (EDTA) bath.
Novel Catalysts for Oxidative Dehydrogenation of Iso-Butane to Iso-Butene
Authors: Takita Yusaku , Kurosaki Kazuo , Mizuhara Yukako , Ishihara Tatsumi
Published: March 2006

Oxidation of iso-butane was studied using metal pyrophosphate catalysts and it was found that iso-butene was formed with 82% selectivity over Ni2P2O7 at 550 °C. Zn2P2O7, Cr4(P2O7)3, and Mg2P2O7 showed 60–70% iso-butene selectivity. and 9–22% selectivity to CO and CO2. Deep oxidation into CO and CO2 was promoted over Cu2P2O7 and Sn2P2O7 Only small amounts of oxygenated products such as alcohols, aldehydes, ketones, and carboxylic acids were formed over every catalyst.
1,2-cis-β-Mannopyranoside Formation by the Dimethylphosphinothioate Method
Authors: Yamanoi Takashi , Nakamura Kazumi , Takeyama Hiroshi , Yanagihara Kenji , Inazu Toshiyuki
Published: March 2006

1,2-cis-β-Mannopyranosides were obtained predominantly by reactions of mannopyranosyl dimethylphosphinothioate derivatives with several alcohols in the presence of iodine and a catalytic amount of triphenylmethyl perchlorate as the activator in benzene.
Dehydrogenative Silylation of Ketones with a Bifunctional Organosilane by Rhodium-Pybox Catalysts
Authors: Nagashima Hideo , Ueda Takanori , Nishiyama Hisao , Itoh Kenji
Published: March 2006

Dehydrogenative silylation of ketones with 1,2-bis(dimethylsilyl)ethane is catalyzed by a mixture of RhCl3(pybox) and AgOTf to form the corresponding silylenol ether in high yields. Only one Si-H group of 1,2-bis(dimethylsilyl)ethane is converted to the corresponding silyl enol ether.
Facile Preparation and Charge-Transfer Complexes of Naphtho[1,8-bc:4,5-b′c′]dithiophene and 2,5-Dimethyl and Bis(methylthio) Derivatives
Authors: Takimiya Kazuo , Yashiki Fumihiko , Aso Yoshio , Otsubo Tetsuo , Ogura Fumio
Published: March 2006

Naphtho[1,8-bc:4,5-b′c′]dithiophene was conveniently prepared via annulation of benzo[1,2-b:4,3-b′]dithiophene and converted to 2,5-dimethyl and bis(methylthio) derivatives. The parent and methylthio compounds have a herringbone type of crystal structures, and formed conductive charge-transfer complexes with iodine and with DDQ.
Separation of Rare Earth Metals by the Chelating Resin Functionalized with Lysine-Nα,Nα-diacetic Acid
Authors: Yokoyama Toshiro , Asami Sigeko , Kanesato Masatoshi , Suzuki Toshishige M
Published: March 2006

Adsorption properties of rare earth elements toward a cross-linked polystyrene resin having functional groups structurally similar to nitrilotriacetic acid (NTA) have been studied. The selectivity sequence of the resin for a series of rare earth metals was in good accordance with that of the corresponding stability constants of NTA complexes. The chromatographic separation of Pr(III) and Nd(III) has been achieved merely by elution with 0.1 mol dm−3 hydrochloric acid.
A Novel Method in Preparation of Pt/KL Catalyst for Aromatization of Hexane
Authors: Dai Lian-Xin , Sakashita Haru , Tatsumi Takasni
Published: March 2006

It has been found that the addition of KCl to the Pt/KL catalyst prepared by ion exchange greatly improves the catalytic activity and selectivity for benzene formation. At the Cl/Pt molar ratio of 3.3, 99.8% conversion of hexane is obtained with an 88.3% yield of benzene.
Electrocatalytic C-C Double Bond Cleavage Reaction of Styrene with Molecular Oxygen Mediated by CuCl2
Authors: Koyama Toshihiro , Kitani Akira , Ito Sotaro , Sasaki Kazuo
Published: March 2006

The electrocatalytic oxidation of styrene with molecular oxygen in the presence of CuCl2 in an acetonitrile solution promotes C-C double bond cleavage reaction to form benzaldehyde. Continuous supply of Cl− is required to keep the catalytic activity.
Chemical Modification of Hectorite by Interlayer-Polymerization of (3-Aminopropyl)trimethoxysilane
Authors: Iwai Makoto , Shoji Hiroshi , Shimazu Shogo , Uematsu Takayoshi
Published: March 2006

Interlayer-polymerization of (3-aminopropyl)trimethoxysilane (APMS) was carried out in the interlayer of lithium hectorite(LHT), and hectorites modified by “tuning guest” such as alkylammonium hectorite(CnNHT) and pyridinium hectorite (PyHT). XRD measurements revealed that the polymer-LHT complex showed no d001 diffraction peaks, while the polymer-CnNHT and -PyHT complexes had definite basal spacings depending on the guest or the amount of APMS. The polymer-clay complexes were characterized by means of 29Si CP/MAS NMR and FT-IR spectra.
Effects of Additives on the Activity of Palladium Catalysts for Methane Combustion
Authors: Ishihara Tatsumi , Shigematsu Hiroyoshi , Abe Yumi , Takita Yusaku
Published: March 2006

Effects of metal oxide additions on the activity of Pd catalysts for CH4 combustion were examined in this study. Since a high concentration of oxygen on Pd surface can be attained, the addition of metal oxide is useful for enhancing the oxidation activity of Pd. In particular, NiO added Pd catalysts are highly active for CH4 combustion, and complete oxidation of CH4 can be attained below 823 K.
High Catalytic Activity of trans-[FeCl2(cyclam)]+ for Peroxidation of Linolenic Acid
Authors: Nishida Yuzo , Tanaka Noriko , Takahashi Shigeyuki
Published: March 2006

The reaction mixture of trans-[FeCl2(cyclam)]+ and linolenic acid exhibited high ability for degradation of tetraphenylcyclopentadienone, one of the famous singlet oxygen(1Δg) quenchers, and the peroxidation of linolenic acid was found to proceed in this solution.
Voltammetric Study on CO2 Reduction Electrocatalyzed by Cobalt Tetraphenylporphine in DMF Solution
Authors: Tezuka Meguru , Iwasaki Masakazu
Published: March 2006

The homogeneous catalysis of cobalt tetraphenylporphine (CoTPP) in the electroreduction of CO2 was investigated by means of cyclic voltammetry (CV). Based on the kinetical treatment of the data, the rate constant for the electron transfer to CO2 from CoTPP dianion could be determined and the activation energy of the step was estimated as 34.5 kJ/mol.
Novel Dinuclear d10-Metallophosphazenes with Unusual Solution Fluxionalities. Synthesis and Structures of [ICu(μ,η3,η3-L)CuI] and [Cl2Zn(μ,η2,η3-L)ZnCl2] (L = Hexakis(3,5-dimethylpyrazolyl)cyclotriphosphazene)
Authors: Min Dongwon , Do Youngkyu
Published: March 2006

Reaction of hexakis(3,5-dimethylpyrazolyl)cyclotriphosphazene(L) with three fold excess amount of MXn in CH2Cl2 gave unprecedented dinuclear metallophosphazenes [XnM(μ-L)MXn] (MXn = CuI, ZnCl2) which show not only novel coordination behaviour of L but also unusual solution fluxionalities involving two metal centers.
Temperature Dependence of Reflectivity in MnSr0.7Ca0.3O3
Authors: Kuroda Masanori , Yokogawa Kiyoshi
Published: March 2006

We measured the temperature dependence of the optical reflection spectrum of MnSr0.7Ca0.3O3, which was prepared by the solid reaction method. It was found that the compound showed distinct optical spectrum change in the cryogenic temperature.
Novel Electro-responsive Property of Polyether-polycarbamate Solution
Authors: Uemura Takashi , Minagawa Keiji , Koyama Kiyohito
Published: March 2006

A polyether-polycarbamate copolymer was prepared by condensation of polypropylene glycol and 4,4′-diphenylmethane diisocyanate. Shear viscosity and dynamic viscoelasticity measurements under an external electric field elucidated that both the viscosity and storage modulus of the copolymer solution reversibly decrease responding to an electric field. This unique response is opposite to the characteristics of so-called electrorheological fluids.
Synthesis of N-terminal Truncated Peptides of Human Epidermal Growth Factor (h-EGF)
Authors: Shin Song Yub , Shimizu Midori , Munekata Eisuke
Published: March 2006

The N-terminal truncated derivatives of h-EGF showed the correct three disulfide linkages in oxidative refolding process and equipotent activity in both the EGF-receptor binding and mitogenesis assay, as compared with authentic h-EGF. This results suggested that the N-terminus of h-EGF have no significant effect on the formation of the correct disulfide linkages and its biological activity.
Enhanced Quantum Yield in Porphyrin Solar Cell with Redox Chain for Electron Transfer
Authors: Takahashi Kohshin , Nakatani Sei-ichiro , Matsuda Tsutomu , Nanbu Hideki , Komura Teruhisa , Murata Kazuhiko
Published: March 2006

The Al/HD/MC/Au sandwich-type photovoltaic cell exhibits a relatively large photocurrent quantum yield of 39% at 445 nm when illuminated with the light of 21.5 μWcm−2 intensity at the Al/HD interface, where MC and HD represent 3-carboxymethyl-5-[(3-ethyl-2(3H)-benzothiazolylidine)ethylidene]-2-thioxo-4-thiazolidinone and a heterodimer consisting of 5,10,15-tri(4-chlorophenyl)-20-(3-pyridyl)porphyrin (H2pyp3p(Cl)) and 5,10,15,20-tetra(2,5-dimethoxyphenyl)porphyrinatozinc (Zntpp(OMe)2), respectively.
A Novel Cyclic Pentapeptide with a β-Hydroxy-γ-chloroproline from Aster tataricus
Authors: Morita Hiroshi , Nagashima Shinji , Takeya Koichi , Itokawa Hideji
Published: March 2006

A novel cyclic pentapeptide with a β-hydroxy-γ-chloroproline residue, named astin I was isolated from the roots of Aster tataricus and the structure was elucidated by the spectroscopic methods.
An Efficient Synthesis of cis-Hydroindan-5-ones by Novel Modified de Mayo Reaction Using 2,3-Dihydro-4-pyrones as the Enone Chromophore
Authors: Sato Masayuki , Sunami Satoshi , Kogawa Tomoyuki , Kaneko Chikara
Published: March 2006

A de Mayo type cyclobutane ring opening of the photo[2 + 2]cycloadduct derived from 2,3-dihydro-4-pyrones and cyclopentene was effected by heating the adduct under an acid catalysis. The 1,2-disubstituted cyclopentanes thus formed spontaneously underwent intramolecular Michael addition to afford cis-hydroindan-5-ones in satisfactory yields.
Novel Imidazolium Benzimidazolate Inner Salts Containing Pentamethylene and Polyether Interannular Spacers. Synthesis and Structural Aspects
Authors: Alcalde Ermitas , Dinarés Immaculada , Pons Josep-María , Roca Tomás
Published: March 2006

For several analogues of heterocyclic betaines 2 and 3, the high dipolar character, due to terminal rings with extreme characteristics within heteroaromatic systems, and the nature of the linkers, had a dominant influence upon their physico-chemical properties in solution. Their structural features enhanced non-covalent interactions inducing coiled conformations.
Effect of a Lithocholic Acid Derivative on the Molecular Packing and Stability of Phospholipid Vesicles
Authors: Li Zi-Chen , Li Fu-Mian , Arase Shinya , Takeoka Shinji , Tsuchida Eishun
Published: March 2006

A lithocholic acid derivative having high compatibility with phospholipid was synthesized and incorporated to the phospholipid bilayer membrane. A significant influence of it on the molecular packing and the stability enhancement of the vesicle suspension were clarified by a fluorescence depolarization method and a turbidity measurement, respectively.
Catalytic Combustion of Carbon Monoxide over YBa2Cu3Ox Electroconductive Catalyst
Authors: Kikuchi Eiichi , Ishihara Tatsuya , Hondoh Masaki
Published: March 2006

Yittrium barium copper oxide (YBa2Cu3Ox), known as high-Tc superconductor was used as an electroconductive catalyst and its characteristics in carbon monoxide oxidation were investigated. When direct current of 3 V was charged, YBa2Cu3Ox was heated to about 450 °C, at which it catalyzed CO oxidation.
Internet Exchanges for Used Books: An Empirical Analysis of Product Cannibalization and Welfare Impact
Authors: Ghose Anindya , Smith Michael D. , Telang Rahul
Published: March 2006

Information systems and the Internet have facilitated the creation of used-product markets that feature a dramatically wider selection, lower search costs, and lower prices than their brick-and-mortar counterparts do. The increased viability of these used-product markets has caused concern among content creators and distributors, notably the Association of American Publishers and Author’s Guild, who believe that used-product markets will significantly cannibalize new product sales.

This proposition, while theoretically possible, is based on speculation as opposed to empirical evidence. In this paper, we empirically analyze the degree to which used products cannibalize new-product sales for books—one of the most prominent used-product categories sold online. To do this, we use a unique data set collected from Amazon.com’s new and used book marketplaces to measure the degree to which used products cannibalize new-product sales. We then use these estimates to measure the resulting first-order changes in publisher welfare and consumer surplus.

Our analysis suggests that used books are poor substitutes for new books for most of Amazon’s customers. The cross-price elasticity of new-book demand with respect to used-book prices is only 0.088. As a result, only 16% of used-book sales at Amazon cannibalize new-book purchases. The remaining 84% of used-book sales apparently would not have occurred at Amazon’s new-book prices. Further, our estimates suggest that this increase in book readership from Amazon’s used-book marketplace increases consumer surplus by approximately $67.21 million annually. This increase in consumer surplus, together with an estimated $45.05 million loss in publisher welfare and a $65.76 million increase in Amazon’s profits, leads to an increase in total welfare to society of approximately $87.92 million annually from the introduction of used-book markets at Amazon.com.
An Extended Privacy Calculus Model for E-Commerce Transactions
Authors: Dinev Tamara , Hart Paul
Published: March 2006

While privacy is a highly cherished value, few would argue with the notion that absolute privacy is unattainable. Individuals make choices in which they surrender a certain degree of privacy in exchange for outcomes that are perceived to be worth the risk of information disclosure. This research attempts to better understand the delicate balance between privacy risk beliefs and confidence and enticement beliefs that influence the intention to provide personal information necessary to conduct transactions on the Internet. A theoretical model that incorporated contrary factors representing elements of a privacy calculus was tested using data gathered from 369 respondents. Structural equations modeling (SEM) using LISREL validated the instrument and the proposed model. The results suggest that although Internet privacy concerns inhibit e-commerce transactions, the cumulative influence of Internet trust and personal Internet interest are important factors that can outweigh privacy risk perceptions in the decision to disclose personal information when an individual uses the Internet. These findings provide empirical support for an extended privacy calculus model.