bluuebunny/crossref_metadata_2025_split huggingface dataset:
Subset threshold autoregression
Authors: So Mike K. P. , Chen Cathy W. S. 
Published: March 2003

AbstractWe develop in this paper an efficient way to select the best subset threshold autoregressive model. The proposed method uses a stochastic search idea. Differing from most conventional approaches, our method does not require us to fix the delay or the threshold parameters in advance. By adopting the Markov chain Monte Carlo techniques, we can identify the best subset model from a very large of number of possible models, and at the same time estimate the unknown parameters. A simulation experiment shows that the method is very effective. In its application to the US unemployment rate, the stochastic search method successfully selects lag one as the time delay and five best models from more than 4000 choices. Copyright © 2003 John Wiley & Sons, Ltd.
Strategic bias, herding behaviour and economic forecasts
Authors: Pons‐Novell Jordi 
Published: March 2003

AbstractProfessional forecasters can have other objectives as well as minimizing expected squared forecast errors. This paper studies whether the people or companies which make forecasts behave strategically with the aim of maximizing aspects such as publicity, salary or their prestige, or more generally to minimize some loss function; or whether, on the contrary, they make forecasts which resemble consensus forecasts (herding behaviour). This study also analyses whether, as forecasters gain more reputation and experience, they make more radical forecasts, that is, they deviate further from the consensus. For this the Livingston Survey is used, a panel of experts who make forecasts on the future evolution of the United States economy. Copyright © 2003 John Wiley & Sons, Ltd.
5‐AZA‐2′‐deoxycytidine (5‐AZA‐CdR): a demethylating agent affecting development and reproductive capacity
Authors: Cisneros F. Javier , Branch Stacy 
Published: March 2003

AbstractThe objective was to evaluate the effects of 5‐AZA‐2′‐deoxycytidine (5‐AZA‐CdR) on postnatal development and reproductive capacity. Pregnant mice were administered 1 mg kg−1 5‐AZA‐CdR at gestation day 10. The body weights of F1 control and treated (in uterine‐exposed) pups were recorded. To evaluate the reproductive capacity, 5‐AZA‐CdR F1 males and females were mated with control mice. The presence of plugs and the number of pregnancies were recorded. The 5‐AZA‐CdR F1 male mice were killed. Total body, testes and epididymis weights were recorded. Spermatid head counting, histological analyses and serum testosterone levels were performed. Body weights of 5‐AZA‐CdR F1 mice were statistically lower than controls (P < 0.01), with the females more strongly affected (P < 0.05). Male mating capacity appeared to be more adversely affected. Mating of 5‐AZA‐CdR F1 males with control females resulted in a lower pregnancy rate compared with control mating groups (P < 0.01). Gross testicular and epididymis weights were lower in 5‐AZA‐CdR F1 mice (P < 0.01). However, testicular and epididymis weights in these mice were higher than controls when correlated to body weight (P < 0.01). In 5‐AZA‐CdR F1 male mice, all measured reproductive parameters, including total number of spermatid heads per testis, are signiﬁcantly lower (P < 0.01) than the controls except for the number of spermatid heads per milligram of testis. Published in 2003 by John Wiley & Sons, Ltd.
Effects of ethylene glycol on the synthesis of ampicillin using immobilized penicillin G acylase
Authors: Wei Dong‐Zhi , Yang Liu 
Published: March 2003

AbstractThe effects of organic cosolvents on the synthesis of ampicillin from phenylglycine methyl ester (PGME) and 6‐amino penicillanic acid (6‐APA) using immobilized Bacillus megaterium penicillin G acylase have been examined. Several cosolvents were tested for their influence on the enzyme in terms of enzyme stability and hydrophobicity. Among the cosolvents tested, ethylene glycol was found to increase the yield of ampicillin by 39–50%. The effects of ethylene glycol on the pKa of PGME, the hydrolysis of ampicillin and PGME, and synthetase/amidase and esterase/amidase ratios were also studied. Experimental data indicated that ethylene glycol inhibited more the hydrolysis of the ampicillin than the hydrolysis of the PGME and the synthetase/amidase ratio varied from 0.2 to 0.88 when the concentration (v/v) of the cosolvent increased from 0 to 40%. The enhancement of the synthesis yield was mainly caused by the reduction in the hydrolysis of acyl donor (PGME) and product (ampicillin) in the water–cosolvent system.© 2003 Society of Chemical Industry
Biodegradability of slaughterhouse wastewater with high blood content under anaerobic and aerobic conditions
Authors: Pozo Rodrigo del , Taş Didem Okutman , Dulkadiroğlu Hakan , Orhon Derin , Diez Victorino 
Published: March 2003

AbstractIn this work, the biodegradability of wastewater from a slaughterhouse located in Keşan, Turkey, was studied under aerobic and anaerobic conditions. A very high total COD content of 7230 mg dm−3 was found, due to an inefficient blood recovery system. Low BOD5/COD ratio, high organic nitrogen and soluble COD contents, were in accordance with a high blood content. A respirometry test for COD fractionation showed a very low readily biodegradable fraction (SS) of 2%, a rapidly hydrolysable fraction (SH) of 51%, a slowly hydrolysable fraction (XS) of 33% and an inert fraction of 6%. Kinetic analysis revealed that hydrolysis rates were much slower than these of domestic sewage. The results underlined the need for an anaerobic stage prior to aerobic treatment. Tests with an anaerobic batch reactor indicated efficient COD degradation, up to around 80% removal. Further anaerobic degradation of the remaining COD was much slower and resulted in the build up of inert COD compounds generated as part of the metabolic activities in the anaerobic reactor. Accordingly, it is suggested that an appropriate combination of anaerobic and aerobic reactors would have to limit anaerobic degradation to around 80% of the tCOD and an effluent concentration above 1000 mg dm−3, for the optimum operation of the following aerobic stage.© 2003 Society of Chemical Industry
Valorisation of waste fractions from autohydrolysis of selected lignocellulosic materials
Authors: Garrote G , Cruz J M , Domínguez H , Parajó J C 
Published: March 2003

AbstractNon‐isothermal processing of lignocellulosic materials in aqueous media (autohydrolysis reaction) under mild conditions leads to solutions containing valuable chemicals (oligosaccharides, sugars and acetic acid) and other, undesired, compounds (belonging to the extractive and acid‐soluble lignin fractions) which have to be removed in further purification treatments. Liquors obtained by non‐isothermal autohydrolysis of Eucalyptus globulus wood and corncobs under a variety of operational conditions were extracted with ethyl acetate in order to remove non‐saccharide components, and the suitability of the fraction dissolved in the organic phase was assayed for possible utilisation as an antioxidant. The yield and antioxidant activity of ethyl acetate extracts (measured by the α,α‐diphenyl‐β‐picrylhydrazyl (DPPH) radical scavenging capacity) showed a strong dependence on the autohydrolysis conditions. The antioxidant activity of extracts obtained under selected operational conditions compared well with synthetic antioxidants.© 2003 Society of Chemical Industry
Thiol‐mediated degradation of DNA adsorbed on a colloidal gold surface
Authors: Mittal Shalu , Bushman Frederic , Orgel Leslie E 
Published: March 2003

AbstractWhen [32P]‐labeled DNA is adsorbed on colloidal gold from a 130 mmol dm−3 solution of KH2PO4, it can subsequently be eluted with cold DNA without undergoing detectable degradation. Similarly, DNA can be incubated in solution in the presence or absence of colloidal gold with high concentrations of β‐mercaptoethanol or hexane‐1‐thiol without significant degradation. However, when adsorbed DNA is eluted from gold with solutions of one of the thiols, it is recovered as a mixture of mononucleotides and short oligomers. The extent of degradation increases with increasing concentration of the thiol and with increasing elution temperature. Our results emphasize that in designing protocols involving DNA adsorbed on gold surfaces, it is important to avoid allowing the DNA to come into contact with even moderate concentrations of thiols.© 2003 Society of Chemical Industry
Kinetics of lipase‐catalysed interesterification of triolein and caprylic acid to produce structured lipids
Authors: Camacho Paez B , Robles Medina A , Camacho Rubio F , Esteban Cerdán L , Molina Grima E 
Published: March 2003

AbstractThe influence of the molar ratio caprylic acid/triolein, enzyme concentration and water content on the kinetics of the interesterification reaction of triolein (TO) and caprylic acid (CA) were studied. The enzyme used was the 1,3‐specific Rhizomucor miehei lipase. Data modelling was based on a simple scheme in which the acid was only incorporated in positions 1 and 3 of the glyceride backbone. In addition, it was assumed that positions 1 and 3 of the triglycerides were equivalent and that the events at position 1 did not depend on the nature of the fatty acid in position 3 and vice versa. Monoglycerides and diglycerides were not detected during the experiments. This was attributed to the low water content of the immobilised enzyme particles. The value of the equilibrium constant, K, for the exchange of caprylic and oleic acids was 2.7, which indicated that the incorporation of caprylic acid into triglycerides was favoured compared with the incorporation of oleic acid. Simple first order kinetics could describe the interesterification reaction. Using this model and the calculated equilibrium constant, the apparent kinetic constants were calculated. The model fitted all the experimental data except for the CA/TO molar ratios larger than 6. Moreover, the interesterification reaction rate had a maximum value at CA/TO molar ratios of 4–6 mol mol−1.Copyright © 2003 Society of Chemical Industry
Highly suppressible expression of single‐chain interleukin‐12 by doxycycline following adenoviral infection with a single‐vector Tet‐regulatory system
Authors: Block Andreas , Puls Florian , Müller Jürgen , Milasinovic Dragan , Igelmann Dana , Schäfer Peter , Kupfermann Nikolai , Schmoldt Achim , Ameis Detlev , Greten Heiner 
Published: March 2003

AbstractBackgroundAdenoviral vectors have been shown to efficiently transfer DNA into a wide variety of eukaryotic cells in vitro and in vivo. However, the therapeutic benefit of this approach is limited by severe side effects as a result of uncontrolled transgene expression.MethodsA bi‐directional promoter that controls the desired transgene as well as a tetracycline‐suppressible transactivator (tTA) was cloned into the E1‐region of E1‐deleted recombinant adenoviral vectors. Autoregulation within this construct was obtained by tTA expression under control of the operator, to which tTA binds in the absence of tetracycline. Consequently, binding of tetracycline to tTA results in downregulation of tTA as well as the co‐expressed transgene in the infected cell.ResultsWe were able to suppress luciferase‐reporter gene expression by up to 16 000‐fold in the presence of doxycycline (dox, 2 µg/ml). Under control of this tetracycline‐regulated system, single‐chain interleukin‐12 (scIL12) was expressed. Adenovirally mediated expression of this potentially lethal cytokine with strong activation of antitumoral immune response was downregulated by up to 6000‐fold in the presence of dox. Subsequently, this downregulation also resulted in a highly significant reduction of interferon‐γ secretion by stimulated splenocytes. These mainly contribute to the toxicity of this immunotherapeutic approach.ConclusionsWith expression levels exceeding those of the cytomegalovirus (CMV) promoter in almost all cell lines tested, these new vectors will also contribute to the safety of adenoviral approaches by controlled expression without compromising on maximum expression levels. Copyright © 2002 John Wiley & Sons, Ltd.
Genotyping single nucleotide polymorphisms by mass spectrometry
Authors: Tost Jörg , Gut Ivo G. 
Published: March 2003

Abstract

I.
Introduction
389

A. A Brief History of DNA Analysis by Mass Spectrometry
389

B. What Exactly Are SNPs
390

C. Why Use MALDI for DNA Analysis?
391

II.
Methods for Allele‐Discrimination
391

A. Hybridization
391

B. Oligonucleotide Ligation
394

C. Cleavage
394

D. Primer Extension
395

1. Purification Procedures and Sample Preparation
395

2. The PinPoint Assay
396

3. The PROBE Assay
398

4. The VSET Assay
398

5. The GenoLINK and GenoSNIP Assay
400

6. The GOOD Assay
400

E. High‐Throughput SNP Genotyping by Mass Spectrometry
401

F. Other Applications
403

1. Quantitation
403

2. Haplotyping
404

3. Epigenotyping
404

4. Analysis of Larger DNA Segments/Complete PCR Products
405

III.
Strategies for the Discovery of Unknown Mutations
406

A. Sequencing by Mass Spectrometry
406

B. Transcription into RNA
407

C. Base‐Specific Fragmentation of Amplified DNA
408

IV.
ESI for DNA Analysis
409

A. Whole PCR Products
409

B. Liquid Chromatography‐ESI
409

C. Cleavage
410

D. The Survivor Assay
410

V.
Use of Other Kinds of Mass Spectrometers for DNA Analysis
410

VI.
Conclusions
411

Acknowledgments
411

Abbreviations
411

References
412

In the last decade, the demand for high‐throughput DNA analysis methods has dramatically increased, mainly due to the advent of the human genome sequencing project that is now nearing completion. Even though mass spectrometry did not contribute to that project, it is clear that it will have an important role in the post‐genome sequencing era, in genomics and proteomics. In genomics, mainly matrix‐assisted laser desorption/ionization (MALDI) mass spectrometry will contribute to large‐scale single nucleotide polymorphism (SNP) genotyping projects. Here, the development and history of DNA analysis by mass spectrometry is reviewed and put into the context with the requirements of genomics. All major contributions to the field and their status and limitations are described in detail. © 2003 Wiley Periodicals, Inc., Mass Spec Rev 21:388–418, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mas.1009
p53 is a regulator of the metastasis suppressor gene Nm23‐H1
Authors: Chen Shen‐Liang , Wu Yi‐Shin , Shieh Hsin‐Ying , Yen Chun‐Che , Shen Jiann‐Jong , Lin Kwang‐Huei 
Published: March 2003

Abstractp53, a tumor suppressor gene involved in the G1 cell cycle checkpoint, is also the most frequently mutated gene in human cancer. In addition, p53 modifies the ability of tumor cells to metastasize. The metastasis‐associated gene Nm23‐H1, which encodes an 18‐kDa nucleoside diphosphate kinase, was previously identified in cells with low metastatic potential. Although p53 and Nm23‐H1 proteins play an important part in regulating the progression of cancer, any functional relationship between these two proteins is currently unknown. Here we report an association between p53 levels and expression of the Nm23‐H1 gene. Our data indicate that wild‐type (wt) p53 upregulated the expression of Nm23‐H1 at protein and mRNA levels in MCF‐7 and J7B cells. This capacity of wt p53 to regulate expression of Nm23‐H1 was not only dependent on the endogenous but also the exogenous origin of p53, and could not be reproduced with mutant p53. Subsequently, the invasive ability of MCF‐7 and J7B cells was suppressed upon induction of the Nm23‐H1 protein by p53. In contrast, increased levels of p53 downregulated the expression of Nm23‐H1 at the protein and mRNA levels in RKO and H1299 cells and, as a consequence, increased the invasive ability of both cell types. Thus, our results implicated the differential regulation of Nm23‐H1 by p53 in different cell types as an important component in the molecular mechanisms of tumor metastasis. © 2003 Wiley‐Liss, Inc.
Skin tumor–promoting potential and systemic effects of pentachlorophenol and its major metabolite tetrachlorohydroquinone in CD‐1 Mice
Authors: Chang Wen‐Ching , Jeng Jiiang‐Huei , Shieh Chi‐Chang , Tsai Yi‐Chang , Ho Yuan‐Soon , Guo How‐Ran , Liu Hsin‐I , Lee Ching‐Chang , Ho Sheng‐Yow , Wang Ying‐Jan 
Published: March 2003

AbstractThe mouse skin carcinogenesis model provides a conceptual framework to study the carcinogenesis process. It has been used extensively to assess whether a chemical or physical agent carries a carcinogenic hazard to humans and to define the mechanism involved with the carcinogenic effects. We conducted a study to evaluate whether the tumor‐promoting activity of pentachlorophenol (PCP) is mainly from its major metabolite tetrachlorohydroquinone (TCHQ). We applied the mouse skin model to CD‐1 mice and the results showed that PCP and TCHQ are much weaker promoters than 12‐O‐tetradecanoylphorbol‐13‐acetate (TPA) in mouse skin during a 25‐wk experiment. Both PCP and TCHQ could induce mice skin epidermal hyperplasia and proliferating cell nuclear antigen (PCNA) labeling index in the epidermis. However, TCHQ caused a more significant induction of epidermal hyperplasia and PCNA positive cells than PCP. Topical application of PCP, but not TCHQ, induced significant organ enlargement and lymphoma in mice, whereas short‐term treatment of TCHQ increased tumor necrosis factor‐α (TNF‐α) gene expression in mouse skin. We did not observe a significant association between the carcinogenic process and serum TNF‐α or interleukin‐1β (IL‐1β) levels in mice. © 2003 Wiley‐Liss, Inc.
Alsterpaullone, a novel cyclin‐dependent kinase inhibitor, induces apoptosis by activation of caspase‐9 due to perturbation in mitochondrial membrane potential
Authors: Lahusen Tyler , De Siervi Adriana , Kunick Conrad , Senderowicz Adrian M. 
Published: March 2003

AbstractThe majority of human neoplasms have aberrations in the retinoblastoma pathway due to hyperactivation of cyclin‐dependent kinases (CDK). Based on this observation, novel small molecules, such as flavopiridol and UCN‐01, are being developed and are currently being tested in the clinic. Efforts to develop CDK modulators led us to the discovery of a novel class of CDK inhibitors, the paullones [Cancer Res 1999;59:2566]. Initial studies demonstrated that paullones inhibit CDKs in vitro, thereby blocking cell‐cycle progression. However, the exact mechanism for the antiproliferative effects of paullones was never explored. In this report, we demonstrate for the first time that the most potent paullone, alsterpaullone (Alp), induced apoptosis and promoted loss in clonogenicity in the Jurkat cell line. Alp caused early activation of both caspase‐8 and ‐9, leading to cleavage of caspase‐3 and poly(ADP‐ribose) polymerase (PARP). Moreover, apoptosis by Alp was not associated with loss in anti‐apoptotic proteins such as XIAP or BCL‐XL. Pre‐incubation with cell‐permeable inhibitors z‐Asp(OMe)‐Glu(OMe)‐Val‐Asp(Ome)‐fluoromethylketone and benzyloxycarbonyl‐Val‐Ala‐Asp (OMe)‐fluoromethylketone (ZVAD) blocked Alp‐induced apoptosis. Moreover, the general caspase inhibitor ZVAD blocked the cleavage and activation of most caspases tested except caspase‐9. Studies of mitochondrial membrane potential also demonstrated that Alp is able to disrupt mitochondrial potential in the presence of ZVAD, suggesting that the activation of caspase‐9 by Alp follows mitochondrial perturbation. Pre‐incubation of Jurkat cells with ZVAD did not prevent the depletion of cyclin D3, loss of CDK, or cell‐cycle arrest by Alp. In summary, these experiments suggest that Alp activates caspase‐9 via mitochondrial perturbation. Active caspase‐9 cleaves and activates caspase‐8 and caspase‐3, leading to apoptosis. In the presence of the general caspase inhibitor ZVAD, the cell‐cycle effects of Alp are unaltered while apoptosis is blocked, suggesting that the CDK effects of Alp are not sufficient for Alp‐induced apoptosis. Additional studies with paullones are warranted to further characterize their preclinical effects and to explore their potential use in the clinical setting. Published 2003 Wiley‐Liss, Inc.
High‐speed countercurrent chromatography as a valuable tool to isolate C‐glycosylflavones from Cecropia lyratiloba Miquel.
Authors: Oliveira R. R. , Moraes M. C. C. , Castilho R. O. , Valente A. P. , Carauta J. P. P. , Lopes D. , Kaplan M. A. C. 
Published: March 2003

AbstractA new apigeninglycoside, apigenin 6‐C‐galactosyl‐6″‐O‐β‐galactopyranoside (1), isoorientin, and a mixture of orientin and isovitexin were isolated from leaves of Cecropia lyratiloba by high‐speed countercurrent chromatography using a solvent system containing ethyl acetate, butanol, methanol and water. The structural elucidation of 1 was based on NMR spectroscopy. Copyright © 2003 John Wiley & Sons, Ltd.
Investigation of the reaction of magnesium with p‐Nitro‐o‐carboxylazochromotropic acid and the determination of magnesium in plants and in water
Authors: Gao Hong‐Wen , Yang Jia‐Xiang , Zhou Zhong‐Ze , Zhao Jian‐Fu 
Published: March 2003

AbstractThe formation of a novel complex between magnesium and p‐nitro‐o‐carboxylazochromotropic acid (NCBAC) has been observed which is sensitive and selective at pH 10.4 in the presence of ethylenediamine and fluoride. The constants of formation of this complex have been determined by a spectral correction technique, and the complexation reaction has been applied to the spectrophotometric determination of trace magnesium in plants and in water with satisfactory results. Copyright © 2003 John Wiley & Sons, Ltd.
Complexation of tetrapropoxycalix[4]arene with uracil and adenine derivatives in water‐containing solution
Authors: Kalchenko Olga , Poznański Jarek , Marcinowicz Agnieszka , Cherenok Sergey , Solovyov Andrew , Zielenkiewicz Wojciech , Kalchenko Vitaly 
Published: March 2003

AbstractThe host–guest complexation of tetrapropoxycalix[4]arene with uracil, 5‐amino‐, 5‐methyl‐, 5‐ethyl‐, 5‐chloro‐, 5‐nitro‐, 6‐methyl‐, 1,3‐dimethyl‐, 6‐amino‐1‐methyl‐ and 6‐amino‐1,3‐dimethyluracil, adenine and 9‐methyladenine in methanol–acetonitrile–tetrahydrofuran–water (15:10:5:70, v/v) solution was investigated by reversed‐phase high‐performance liquid chromatography. The association constants of the 1:1 host–guest complexes of the guests with the calixarene host within the range 3250–54300 M
−1 were determined from the capacity factor of the guest and concentration of the calixarene host in the mobile phase. Molecular dynamic (MD) simulation of the host–guest interaction was performed. Basing on the MD trajectories atomic partition to the net molecular solvent‐exposed surface was analyzed for the separated guest and host molecules and for the complex. Copyright © 2003 John Wiley & Sons, Ltd.
An analysis of bifurcated H‐bonds: crystal and molecular structures of O,O‐diphenyl 1‐(3‐phenylthioureido)­pentanephosphonate and O,O‐diphenyl 1‐(3‐phenylthioureido)butanephosphonate
Authors: Chęcińska Lilianna , Grabowski Sławomir J. , Małecka Magdalena 
Published: March 2003

AbstractIn the crystal structures of O,O‐diphenyl 1‐(3‐phenylthioureido)pentanephosphonate (1) and O,O‐diphenyl 1‐(3‐phenylthioureido)butanephosphonate (2) analysed here, bifurcated H‐bonds within R21(6) motifs are formed. It seems that such interactions play a crucial role in the crystal architecture. This is supported by ab initio MP2/6–311 ++ G** calculations on simple, modelled complexes of urea, thiourea and their derivatives with water, where the oxygen atom of water molecule is the bifurcated proton‐accepting centre. The calculations show that single H‐bonds within bifurcated systems are of medium strength (2.7–3.6 kcal mol−1). The topological parameters obtained from the Bader theory are applied for the analysis of these bifurcated H‐bonds. Copyright © 2003 John Wiley & Sons, Ltd.