bluuebunny/crossref_metadata_2025 huggingface dataset:
Methacrylate monolithic columns for capillary liquid chromatography polymerized using ammonium peroxodisulfate as initiator
Authors: Holdšvendová Petra , Coufal Pavel , Suchánková Jana , Tesařová Eva , Bosáková Zuzana
Published: December 2003

Four methacrylate ester‐based monolithic columns for capillary liquid chromatography (CLC) were prepared by radical polymerization with ammonium peroxodisulfate (3 columns) and by thermal initiation (1 column). The polymerization mixture consisted of butyl methacrylate (BMA) and ethylene glycol dimethacrylate (EDMA), propan‐1‐ol, butane‐1,4‐diol, water, and ammonium peroxodisulfate as initiator. It was necessary to add N,N,N′,N ′‐tetramethylethylenediamine (TEMED) to the polymerization mixture to activate the reaction. The amount of initiator and activator was optimized to attain quantitative polymerization. The reproducibility of three columns prepared at ambient temperature was studied. The most efficient column with HETP of 29 μm for uracil was compared to the monolithic column prepared by thermal initiation with α,α′‐azobisisobutyronitrile (AIBN). The efficiencies of all the test columns were characterized by van Deemter curves. Their total porosities were calculated from the retention time of uracil. Walters indices of hydrophobicity (HI) were calculated from the retention factors of anthracene and benzene. The columns prepared by both methods are comparable in their selectivities and efficiencies. They show the same characteristics because their total porosities and Walters indices of hydrophobicity are consistent. However, the preparation of monoliths using ammonium peroxodisulfate was less demanding, because polymerization was possible at ambient temperature.
Effect of analyte lipophilicity on the resolution of α‐ and β‐amino acids on liquid chromatographic ligand exchange chiral stationary phases
Authors: Hyun Myung Ho , Whangbo Sung Hee , Cho Yoon Jae
Published: December 2003

Separation of the two enantiomers of racemic α‐ and β‐amino acids on two ligand exchange chiral stationary phases (CSPs) prepared previously by covalently bonding sodium N‐((S)‐1‐hydroxymethy‐3‐methylbutyl)‐N‐undecylaminoacetate or sodium N‐((R)‐2‐hydroxy‐1‐phenylethyl)‐N‐undecylaminoacetate on silica gel was studied with variation of the organic modifier (methanol) concentration in the aqueous mobile phase. In particular, the variation of retention factors with changing organic modifier concentration in the aqueous mobile phase was found to be strongly dependent on both the analyte lipophilicity and the stationary phase lipophilicity. In general, the retention factors of relatively lipophilic analytes on relatively lipophilic CSPs tend to increase with increasing organic modifier concentration in the aqueous mobile phases while those of less lipophilic or hydrophilic analytes tend to increase. However, only highly lipophilic analytes show decreasing retention factors with increasing organic modifier concentration in the aqueous mobile phase on less lipophilic CSPs. The contrasting retention behaviors on the two CSPs were rationalized by the balance of the two competing interactions, viz. hydrophilic interaction of analytes with polar aqueous mobile phase and the lipophilic interaction of analytes with the stationary phase.
Analysis of levofloxacin in pharmaceutical preparations by high performance thin layer chromatography
Authors: Meyyanathan S. N. , Ramasarma G. V. S. , Suresh B.
Published: December 2003

A new simple, precise, rapid, and selective high‐performance thin layer chromatography (HPTLC) method has been developed for the analysis of levofloxacin in pharmaceutical formulations. The method uses lamotrigine as an internal standard. The stationary phase was silica gel 60F254 prewashed with methanol; water‐methanol‐n‐butanol‐ammonia solution 5 + 5 + 5 + 0.4 (v/v) was used as mobile phase. Detection and quantification were performed densitometrically at λ = 298 nm. The linear range of the analysis was 0.8–3.0 μg and the percentage recovery was 99.90%.
Treatment of cervical dentin hypersensitivity using neodymium: Yttrium–aluminum–garnet laser. Clinical evaluation
Authors: Ciaramicoli Márcia T. , Carvalho Rubens C. R. , Eduardo Carlos P.
Published: December 2003

Background and Objective

The incidence of cervical dentinal hypersensitivity is related to the high number of non‐carious cervical lesions. This clinical research was developed in order to evaluate the Nd:YAG laser treatment of cervical dentin hypersensitivity after attempting the removal and control of etiologic factor after two different stimuli.

Study Design/Materials and Methods

Twenty patients participated in this study in a total of 145 teeth, where 104 received the Nd:YAG laser treatment and 41 remained as control.

Results

The results showed that there was statistically significant reduction of hypersensitivity as for the groups that received the treatment with Nd:YAG laser, as for the control teeth. However, the reduction of cervical dentinal hypersensitivity was statistically greater when there was the association of the removal of etiologic factors with the application of Nd:YAG laser.

Conclusions

We concluded that the laser irradiation was effective in the treatment of cervical dentin hypersensitivity after 6 months. Lasers Surg. Med. 33:358–362, 2003. © 2003 Wiley‐Liss, Inc.
Treatment of resistant port wine stains with the V Beam® pulsed dye laser
Authors: Laube Simone , Taibjee Saleem , Lanigan Sean W.
Published: December 2003

Background and Objectives

Pulsed dye lasers (PDL; 585 nm, 0.45 millisecond) are the treatment of choice for port wine stains (PWS). However, clearance rates vary widely and are in many patients incomplete. The objective of this prospective pilot study was to investigate the effects of a long pulse‐duration 595 nm PDL (V Beam®, Candela Laser Corporation, Wayland, MA) on previously treated PWS to ascertain whether further lightening can be obtained. Treatment response was assessed subjectively (photographs) and objectively with noninvasive techniques (reflectance spectrophotometer and spectrophotometric intracutaneous analysis scope (SIAscope)).

Study Design/Materials and Methods

Twelve adult patients with congenital PWS each had four test patches with different spot sizes, fluences, and pulse widths carried out. The test area with the best response was selected and two laser treatments were performed at weeks 8 and 16. Photographs and measurements with a reflectance spectrophotometer and SIAscope (Astron Clinica, Cambridge, UK) were performed at baseline, before each treatment and at final review at week 24.

Results

Of the nine patients who completed the study three patients showed a good response (51–75% lightening), which was supported by measurements with the reflectance spectrophotometer and the SIAscope. A further three patients had fair improvement (26–50% lightening) and three patients had a minor or no response (0–25% lightening). In two patients a discrepancy between the degree of clinical response and some of the objective measurements was noticed.

Conclusions

The 595 nm V Beam® PDL appears to achieve further lightening of therapy‐resistant PWS in the majority of patients (67%). Both reflectance spectrophotometer and SIAscope appear to permit assessment of objective treatment responses. Results require confirmation in larger studies. Lasers Surg. Med. 33:282–287, 2003. © 2003 Wiley‐Liss, Inc.
Efficacy of different therapy regimes of low‐power laser in painful osteoarthritis of the knee: A double‐blind and randomized‐controlled trial
Authors: Gur Ali , Cosut Abdulkadir , Jale Sarac Aysegul , Cevik Remzi , Nas Kemal , Uyar Asur
Published: December 2003

Background and Objectives

A prospective, double‐blind, randomized, and controlled trial was conducted in patients with knee osteoarthritis (OA) to evaluate the efficacy of infrared low‐power Gallium‐Arsenide (Ga‐As) laser therapy (LPLT) and compared two different laser therapy regimes.

Study Design/Materials and Methods

Ninety patients were randomly assigned to three treatment groups by one of the nontreating authors by drawing 1 of 90 envelopes labeled ‘A’ (Group I: actual LPLT consisted of 5 minutes, 3 J total dose + exercise; 30 patients), ‘B’ (Group II: actual LPLT consisted of 3 minutes, 2 J total dose + exercise; 30 patients), and ‘C’ (Group III: placebo laser group + exercise; 30 patients). All patients received a total of 10 treatments, and exercise therapy program was continued during study (14 weeks). Subjects, physician, and data analysts were unaware of the code for active or placebo laser until the data analysis was complete. All patients were evaluated with respect to pain, degree of active knee flexion, duration of morning stiffness, painless walking distance and duration, and the Western Ontario and Mc Master Universities Osteoarthritis Index (WOMAC) at week 0, 6, 10, and 14.

Results

Statistically significant improvements were indicated in respect to all parameters such as pain, function, and quality of life (QoL) measures in the post‐therapy period compared to pre‐therapy in both active laser groups (P < 0.01). Improvements in all parameters of the Group I and in parameters, such as pain and WOMAC of the Group II, were more statistically significant when compared with placebo laser group (P < 0.05).

Conclusions

Our study demonstrated that applications of LPLT in different dose and duration have not affected results and both therapy regimes were a safe and effective method in treatment of knee OA. Lasers Surg. Med. 33:330–338, 2003. © 2003 Wiley‐Liss, Inc.
Photothermal detection of laser‐induced damage in single intact cells
Authors: Lapotko Dmitri O. , Lukianova Ekaterina Y. , Shnip Alexander I.
Published: December 2003

Background and Objective

Most of the studies of laser‐induced damage do not analyze individual cells. Objective of this work was to evaluate local photo‐induced thermal phenomena in single cells at theoretical and experimental levels for developing the method for real‐time detection of laser damage in intact cells.

Study Design/Materials and Methods

Theoretical model of cell–laser interaction assumes local nature of photo‐induced thermal effects and describes photodamage through bubble formation. Photothermal (PT) method was suggested for damage detection. Laser‐induced damage was verified for individual cells with two techniques through detection of Trypan blue penetration into damaged cell.

Results

Specific PT responses from blast‐transformed lymphocytes were identified independently as result of bubble formation and cell damage. Probability of cell damage was obtained for cells as function of laser pulse energy.

Conclusions

The Laser load test (LLT) was suggested for real‐time detection of damage, damage threshold measurement, and investigation of intact single cells. Lasers Surg. Med. 33:320–329, 2003. © 2003 Wiley‐Liss, Inc.
A new method for assessment of corrosion around a scribe in the coating on a metal sheet
Authors: Oelßner W. , Berthold F. , Werner H.
Published: December 2003

Scratches or any other defects in the polymer coating on metallic materials are preferred sites of increased corrosion attack. The undermining of coatings originating from such a damage is of great practical relevance and thus now as before also subject of scientific studies. In the paper a new method for in situ measurements of corrosion processes under coatings by using a sensor array will be presented. The progress of undermining originating from a scribe was determined by resistance and impedance measurements between individual sensor elements and the metallic substrate in dependency on the substrate material and other parameters.
Polythiophenylene synthesis through multi‐electron transfer process
Authors: Oyaizu Kenichi , Tsuchida Eishun
Published: December 2003

Superacidification of aromatic sulfoxides effects the electrophilic substitution reaction of the resulting hydroxysulfonium ions onto aromatic rings with the elimination of H2O at room temperature. The product, the alkyldiarylsulfonium ion, allows the synthesis of alkylsulfonio‐bridged (λ4‐alkylsulfanyliumdiyl) aromatic polymers. High molecular‐weight poly(alkylsulfonioarylene) salts have been made accessible by the regioselective condensation of aryl sulfoxides. Polymers having a wide variety of structural dimensionalities such as linear, hyper‐branched and ladder‐type structures can be prepared by this method, which possess interesting properties such as good solubility in polar organic solvents and sometimes even in H2O, susceptibility to nucleophiles to provide thioarylene derivatives, photo‐degradability, and electric semiconductivity based on a 3d‐2p interaction in aryl sulfonium ion.
Synthesis of poly(ethynylplatinumporphyrin) and its application as an oxygen pressure‐sensitive paint
Authors: Hah Hyundae , Sakai Tomoyuki , Asai Keisuke , Nishide Hiroyuki
Published: December 2003

5‐(4‐Trimethylsilyethynylphenyl)‐10,15,20‐triphenylplatinumporphyrin was synthesized and copolymerized with trimethylsilylpropyne to give a new high‐molecular‐weight porphyrin polymer. The polymer formed a smooth and tough coating on many types of surfaces. The coating showed a strong blue luminescence from the platinumporphyrin residue which was quenched in the presence of oxygen. The relationship of the luminescence intensity vs oxygen pressure displayed a remarkably high pressure sensitivity in the low oxygen pressure area, which was ascribed to the high oxygen permeability of the polymer.
Polysaccharides based hydrogels for biological applications
Authors: Barbucci R. , Consumi M. , Lamponi S. , Leone G.
Published: December 2003

Polysaccharides based hydrogels show several peculiar properties which can be so reassumed:

• Capability to absorb a great amount of water once immersed in biological fluids, assuming, consequently, a structure similar to extracellular matrix or biological tissue

• Tissotropic property, i.e. possibility to be injected through a needle without lose of their rheological properties.

These fundamental properties make them ideal materials for several biomedical applications, such as cellular scaffold, coatings for biomedical disposals, treatments for different diseases, controlled release of drugs, etc.

Hyaluronane, Carboxymethyl cellulose and Alginic acid based 50% hydrogels (i.e. 50% of the carboxylate groups present in the macromolecule chain were involved in the cross‐linking reaction) are synthesised. Their effectiveness in promoting cells adhesion and proliferation was verified. Furthermore the possibility of injecting and sterilising hydrogels permitted to test the effect of Hyal 50% in the osteoarthritis therapy. It was found that the in vivo effect of Hyal 50% in the treatment of surgically created chondral defect in the rabbit knee was positive.

These materials can be both chemically and morphologically modified. In fact, the insertion of sulphate groups increase their hemocompatibility as demonstred by the increase of TT (time necessary to turn the fibrinogen to thrombin). Furthermore microporous hydrogels were obtained and tested as drug controlled release systems.
Specific electron transfer mechanism from the photoexcited tetrasulfonated Zn(II)‐tetraphenylporphyrin to methylviologen via self‐assembled ionic complex
Authors: Kaneko M. , Suzuki K. , Ebel Esther , Wöhrle Dieter
Published: December 2003

Electron transfer from photoexcited tetrasulfonated Zn(II)‐tetraphenylporphyrin (ZnTSTPP) to methyviologen (MV2+) was studied. From the investigation of relative fluorescence intensity and emission lifetime against the MV2+ concentration, it was concluded that the electron transfer takes place by a static mechanism. Based on the analysis of the quenching behavior, it was concluded that the static reaction did not follow an ordinary Perrin model, but interaction of the donor (photoexcited Zn‐TSTPP) and the acceptor (MV2+) molecules, ionic interaction in the present case, is responsible. The analysis of the quenching gave the equilibrium constant for the interaction to be K = 6.5 × 104 M−1. A two‐dimensional selfassembled macromolecular ionic complex between ZnTSTPP and MV2+ is proposed.
Dimensionally oriented redox‐active π‐conjugated systems
Authors: Hirao Toshikazu , Saito Kaori
Published: December 2003

Porphyrins bearing the redox‐active phenylenediamine pendant groups are synthesized to afford dimensionally oriented π‐conjugated systems. The structural and electronic characteristics depend on the atropisomers. In the fluorescence emission spectra, the emission from the porphyrin moiety is almost completely quenched. Zinc complexation of the αααα isomers gives the corresponding zinc porphyrins bearing four phenylenediamine strands. Treatment with a bidentate ligand, DABCO, leads to the sandwich dimer complex, in which the porphyrin moieties are surrounded by π‐conjugated pendant groups. p‐t‐Butylcalix[4]arenes bearing four redox‐active phenylenediamine pendant groups on the lower rim are synthesized and characterized both spectroscopically and electrochemically. The interconversion of the oxidation states of the pendant groups is demonstrated both chemically and electrochemically.
Soluble polymeric ligands for metal complexation and catalyst recovery
Authors: Bergbreiter David E. , Frels Jonathon D. , Li Chunmei
Published: December 2003

Soluble polymers that bind metals and that in turn can be separated from other components of a reaction mixture are described. The polymers used include derivatives of acrylamides, acrylates, polystyrene and other polymers. Both sequestration of trace metals and recovery of homogeneous catalysts is discussed. Separation methods using liquid/liquid mixtures that are monophasic during a reaction but biphasic during a separation are emphasized.
Comparative study of Cu(II) catalytic sites immobilized onto different polymeric supports
Authors: Kucherov A. , Finashina E. , Kramareva N. , Rogacheva V. , Zezin A. , Said‐Galiyev E. , Kustov L.
Published: December 2003

The catalysts with copper(II) ions stabilized onto different polymeric matrixes are prepared on either bulk (Cu/chitosan, Cu/polyethyleneimine‐polyacrylic acid (PPA), and Cu‐diiminate‐impregnated polystyrene, polyarylate, or polymethylmethacrylate) or composite supports (egg‐shell type Cu/chitosan/SiO2 and Cu/PPA/SiO2). The morphology of the samples and peculiarities of Cu(II) cationic sites are studied by SEM and ESR methods, and the catalyst activities are compared in oxidation of o‐ and p‐dihydroxybenzenes by air in water. The catalytic activity of Cu(II) centers is governed by the coordination of isolated copper ions: for the most active catalysts, i.e., Cu/chitosan and Cu/PPA, the symmetry of isolated Cu2+‐sites approximates a coordinatively unsaturated square‐planar structure. At the same time, accessibility of active sites to water differs for different polymers, so the contribution of hydrophilicity to the reaction pattern cannot be excluded. Redox transformations of the active sites in the course of catalytic tests do not cause copper leaching from the polymer matrix. The binary composite systems with a film of low‐loaded hydrofilic Cu‐polymer supported on macroporous SiO2 demonstrate substantially higher activity in oxidation of hydroquinone and 3,4‐dihydroxyphenylalanine, as compared with the bulk Cu/polymer samples. In turn, the specific activity of Cu/chitosan/SiO2 exceeds significantly that of Cu/PPA/SiO2 due to stabilization of a thinner and more uniform film of chitosan at the surface of silica.
Synthesis and properties in solution of ruthenium(II) coordination polymers
Authors: Knapp Ralf , Knapp Ralf , Kelch Steffen , Schmelz Oliver , Rehahn Matthias
Published: December 2003

Synthetic strategies are presented for the preparation of readily soluble ruthenium(II) coordination polymers of high molecular weight. The constitutional homogeneity of the polymers is proved using high‐resolution NMR spectroscopy, and their molar masses are estimated from 1H NMR spectra, viscosity data and SAXS investigations. The polymers are shown to be conformationally rigid, and to form either densely packed coils or rods. It is mainly this difference in shape which causes the very specific properties of the respective polyelectrolytes in the solid state as well as in dilute solution. Finally, the UV‐vis absorption spectra of some of these materials are presented.
An investigation of the role of scale values in the DS/AHP method of multi‐criteria decision making
Authors: Beynon Malcolm J.
Published: December 2003

DS/AHP is a method of multi‐criteria decision making based on the Dempster–Shafer theory of evidence and the analytic hierarchy process. Central to the utilization of DS/AHP is the composing of preference judgements on identified groups of decision alternatives (DA) across a number of criteria against all the DA present in the problem in question. This paper exposits a series of results whose objectives are to aid in the development of an effective set of preference scale values for use within DS/AHP. These results relate directly to the concomitant level of ignorance (uncertainty) with the judgements made on a single criterion. Two particular directions of investigation are undertaken, firstly in determining the necessary number of scale values available and secondly finding the necessary differences between scale values, dependent on whether an arithmetic or geometric progression is the basis for the scale values. Through an example, the implications and utilization of these results within DS/AHP are illustrated. Copyright © 2003 John Wiley & Sons, Ltd.
Proteome profiling and its use in metabolic and cellular engineering
Authors: Han Mee‐Jung , Lee Sang Yup
Published: December 2003

Proteome profiling of microorganisms makes it possible to generate valuable knowledge that can be used for the development of metabolic and cellular engineering strategies, which consequently are used to enhance the yield and productivity of native or foreign bioproducts and to modify cellular properties to improve mid‐stream and down‐stream processes. Advances in two‐dimensional gel electrophoresis technology combined with mass spectrometry allow the creation of global scale proteome contents which can be used to elucidate valuable information on the dynamics of the metabolic, signaling and regulatory networks apart from understanding the physiological changes. In this paper, we review the approaches of exploiting the proteome profiling results to the development of the strategies for the metabolic and cellular engineering of microorganisms.
Proteome analysis of the responses of Panax ginseng C. A. Meyer leaves to high light: Use of electrospray ionization quadrupole‐time of flight mass spectrometry and expressed sequence tag data
Authors: Nam Myung Hee , Heo Eun Joo , Kim Jin Young , Kim Seung Il , Kwon Kyung‐Hoon , Seo Jong Bok , Kwon Ohoak , Yoo Jong Shin , Park Young Mok
Published: December 2003

We performed comparative proteomic analyses in order to understand the physiological responses of ginseng (Panax ginseng C. A. Meyer) to high light (HL). As a first step, we analyzed the proteins expressed in ginseng leaves. Proteins extracted from leaves were separated by two‐dimensional polyacrylamide gel electrophoresis. Protein spots were identified by tandem mass spectra analysis using electrospray ionization quadrupole‐time of flight mass spectrometry (ESI Q‐TOF MS). We used a ginseng expressed sequence tag (EST) database as well as a nonredundant protein database from NCBI to identify proteins. Eighty‐one proteins were identified using the nr protein database, 51 of which were also verified from the ginseng EST database. An additional 66 proteins were identified only from the ginseng EST database. Proteins that function in energy metabolism, protein stabilization, and protection against oxidative stress were abundant. To understand the light responses of ginseng leaves, we studied time dependent changes in expressed proteins produced by 0–4 h of HL exposure. Six HL‐responsive proteins were identified: three proteins were up‐regulated (cytosolic small heat‐shock protein, cytosolic ascorbate peroxidase, and putative major latex‐like protein) and three proteins were down‐regulated (Rieske Fe/S protein, putative 3‐beta hydroxysteroid dehydrogenase/isomerase‐like protein, and oxygen‐evolving enhancer‐like protein). Our results show that the ginseng EST database combined with ESI Q‐TOF MS analysis can be used to identify ginseng proteins and to elucidate the protective mechanism of ginseng against HL induced damage.
Improvement of the two‐dimensional gel electrophoresis analysis for the proteome study of Halobacterium salinarum
Authors: Cho Chang‐Won , Lee So‐Hee , Choi Jiyeon , Park Soo‐Jin , Ha Dong‐Jin , Kim Hyo‐Jeong , Kim Chan‐Wha
Published: December 2003

Inherent problems exist in the use of two‐dimensional gel electrophoresis (2‐DE) for sample preparation and separation of proteins from Halobacterium salinarum. In particular, proteins from cells grown in 25% NaCl are difficult to resolve by 2‐DE due to the abundance of salt. To remove salts, a 3 kDa molecular weight cut‐off column was used. When soluble proteins were separated by 2‐DE, most of the proteins were concentrated in the acidic range. For separation of proteins in the pH 3–6 range, ultrazoom immobilized pH gradient strips were used. In addition, sample separation using a IPGphor/Multiphor combined system was a more effective method for the proteome analysis of acidic proteins than using IPGphor for the isoelectric focusing step.
ProteoChip: A highly sensitive protein microarray prepared by a novel method of protein immobilization for application of protein‐protein interaction studies
Authors: Lee Yoonsuk , Lee Eun Kyoung , Cho Yong Wan , Matsui Takuya , Kang In‐Cheol , Kim Tai‐Sun , Han Moon Hi
Published: December 2003

We have developed a highly sensitive microarray protein chip, ProteoChip, coated with ProLinker™, novel calixcrown derivatives with a bifunctional coupling property that permits efficient immobilization of capture proteins on solid matrixes and makes high‐throughput analysis of protein‐protein interactions possible. The analysis of quartz crystal microbalance showed that both monoclonal antibody (mAb) and antigen (Ag) bound to the gold film of the sensor surface coated with ProLinker™ B and that it is useful for studies of Ab‐Ag interactions. ProteoChip, aminated glass slide coated with ProLinker™ A, was also demonstrated to be useful for preparation of high‐density array spots by using a microarrayer and for analysis of analyte Ags either by direct or sandwich methods of fluorescence immunoassay. The detection sensitivity of ProteoChip was as low as 1–10 femtogram/mL of analyte protein, useful for detection of tumor markers. ProteoChip was also useful for studies of direct protein‐protein interactions as demonstrated by analysis of integrin‐extracellular matrix protein interaction. These experimental results suggest that ProteoChip is a powerful tool for development of chip‐based lead screening microarrays to monitor protein‐protein interactions (i.e. drug target) as well as for biomarker assays which require high detection sensitivity.
Proteomic analysis of Candida magnoliae strains by two‐dimensional gel electrophoresis and mass spectrometry
Authors: Lee Do‐Yup , Park Yong‐Cheol , Kim Hyo‐Jin , Ryu Yeon‐Woo , Seo Jin‐Ho
Published: December 2003

Candida magnoliae which has been newly isolated from honey comb is an osmotolerant yeast to produce erythritol as a major product. Erythritol is a noncariogenic, low calorie sweetener and safe for diabetics. Strain development by chemical mutation to obtain the improved erythritol yield and productivity relative to the parental strain made it necessary to elucidate the physiological differences between the wild and mutant strains. Proteomic analyses of C. magnoliae wild and mutant strains with two‐dimensional gel electrophoresis and nanoelectrospray mass spectrometry were carried out to identify intracellular proteins and to estimate the effects of newly characterized metabolic enzymes on the yeast cell growth and erythritol production. Most of the molecular mass of intracellular proteins were distributed in the range of pI 4–8 and molecular mass of ∼ 130 kDa. Six out of nine protein spots expressed at different levels between the wild and mutant strains were analyzed with nanoelectrospray tandem mass spectrometry and identified by comparing amino acid sequences with the National Center for Biotechnology Information and Saccharomyces Genome Databases. Except for Ygr086cp, these proteins were believed to be the metabolic enzymes involved in the citric acid cycle (citrate synthase, succinyl‐CoA ligase and fumarase) and the glycolysis pathway (pyruvate decarboxylase and enolase). Up‐regulated enzymes in the citric acid cycle could explain high growth of the C. magnoliae mutant strain owing to the increased NADH and ATP formation. Down‐regulated enolase and up‐regulated fumarase in the mutant strain seemed to play a role in the improved bioconversion of erythrose‐4‐phosphate to erythritol compared with the wild strain.
Comparative analysis of nuclear proteins of B cells in different developmental stages
Authors: Jin Sun Hee , Cho Eun Hye , Ko Jung Eun , Jung Eun Hee , Ahn Byungchan , Hahm Jong Ryeal , Kim Jae Won , Kim Choong Won , Kim Deok Ryong
Published: December 2003

The developmental stage‐specific regulation of V(D)J recombination, a gene rearrangement process of antigen receptor gene segments, is tightly controlled in cells. Here we screened proteins uniquely or differentially expressed among three developmentally distinguishable B cells (pro‐B, pre‐B and mature B cells) using two‐dimensional gel electrophoresis and mass spectrometry. Chromatin assembly factor 1 was uniquely expressed in pro‐B cells. Purine nucleotide phosphorylase, LCK, E2A and many other unidentified proteins were dominantly present in the nucleus at the early stage of B cell development where the V(D)J recombination process occurs. Also, few proteins including guanidine nucleotide binding proteins were exclusively expressed in pre‐B cell. Such findings can provide some information to help understand the developmental regulation of gene rearrangement occurring during B cell development.
Proteomic analysis of differentially expressed proteins induced by rice blast fungus and elicitor in suspension‐cultured rice cells
Authors: Kim Sun Tae , Cho Kyu Seong , Yu Seok , Kim Sang Gon , Hong Jong Chan , Han Chang‐deok , Bae Dong Won , Nam Myung Hee , Kang Kyu Young
Published: December 2003

We used two‐dimensional electrophoresis (2‐DE) and other proteomic approaches to identify proteins expressed in suspension‐cultured rice cells in response to the rice blast fungus, Magnaporthe grisea. Proteins were extracted from suspension‐cultured cells at 24 and 48 h after rice blast fungus inoculation or treatment with elicitor or other signal molecules such as jasmonic acid (JA), salicylic acid, and H2O2. The proteins were then polyethylene glycol fractionated before separation by 2‐DE. Fourteen protein spots were induced or increased by the treatments, which we analyzed by N‐terminal or internal amino acid sequencing. Twelve proteins from six different genes were identified. Rice pathogen‐related protein class 10 (OsPR‐10), isoflavone reductase like protein, β‐glucosidase, and putative receptor‐like protein kinase were among those induced by rice blast fungus; these have not previously been reported in suspension‐cultured rice cells. Six isoforms of probenazole‐inducible protein (PBZ1) and two isoforms of salt‐induced protein (SalT) that responded to blast fungus, elicitor, and JA were also resolved on a 2‐DE gel and identified by proteome analysis. The expression level of these induced proteins both in suspension‐cultured cells and in leaves of whole plants was analyzed by Western blot. PBZ1, OsPR‐10, and SalT proteins from incompatible reactions were induced earlier and to a greater extent than those in compatible reactions. Proteome analysis can thus distinguish differences in the timing and amount of protein expression induced by pathogens and other signal molecules in incompatible and compatible interactions.
A fluorescent natural product for ultra sensitive detection of proteins in one‐dimensional and two‐dimensional gel electrophoresis
Authors: Mackintosh James A. , Choi Hung‐Yoon , Bae Soo‐Han , Veal Duncan A. , Bell Philip J. , Ferrari Belinda C. , Van Dyk Derek D. , Verrills Nicole M. , Paik Young‐Ki , Karuso Peter
Published: December 2003

Lightning Fast is a sensitive fluorescence‐based stain for detecting proteins in one‐dimensional and two‐dimensional polyacrylamide electrophoresis gels. It contains the fluorophore epicocconone from the fungus Epicoccum nigrum that interacts noncovalently with sodium dodecyl sulfate and protein. Stained proteins can be excited optimally by near‐ultraviolet light of about 395 nm or with visible light of about 520 nm. The stain can be excited using a range of sources used in image analysis systems including UVA (ca. 365 nm) and UVB (ca. 302 nm) transilluminators; Xenon‐arc lamps; 488 nm and 457 nm Argon‐ion lasers; 473 nm and 532 nm neodymium: yttrium aluminum garnet (Nd:YAG) solid‐state lasers; 543 nm helium‐neon lasers, and emerging violet, blue and green diode lasers. Maximum fluorescence emission of the dye is at approximately 610 nm. The limit of detection in one‐dimensional gels stained with Lightning Fast protein gel stain is less than 100 pg of protein, rivaling the current limits of matrix‐assisted laser desorption/ionization‐mass spectrometry (MALDI‐MS). Lightning Fast was found to be considerably more sensitive than SYPRO Ruby, SYPRO Orange, silver and Coomassie Brilliant Blue G‐250 in matched experiments. Staining takes as little as 3.5 h and stained proteins displayed quantitative linearity over more than four orders of magnitude, thereby allowing visualization of entire proteomes. Lightning Fast protein gel staining is compatible with subsequent peptide mass fingerprinting using MALDI‐MS and Edman‐based sequencing chemistry.
Strategic shotgun proteomics approach for efficient construction of an expression map of targeted protein families in hepatoma cell lines
Authors: Lee Chih‐Lei , Hsiao He‐Hsuan , Lin Chia‐Wei , Wu Szu‐Pei , Huang Shiuan‐Yi , Wu Chi‐Yue , Wang Andrew H.‐J. , Khoo Kay‐Hooi
Published: December 2003

An expression map of the most abundant proteins in human hepatoma HepG2 cells was established by a combination of complementary shotgun proteomics approaches. Two‐dimensional liquid chromatography (LC)‐nano electrospray ionization (ESI) tandem mass spectrometry (MS/MS) as well as one‐dimensional LC‐matrix‐assisted laser desorption/ionization MS/MS were evaluated and shown that additional separation introduced at the peptide level was not as efficient as simple prefractionation of protein extracts in extending the range and total number of proteins identified. Direct LC‐nanoESI MS/MS analyses of peptides from total solubilized fraction and the excised gel bands from one‐dimensional sodium dodecyl sulfate‐polyacrylamide gel electrophoresis fractionated insolubilized fraction afforded the best combination in efficient construction of a nonredundant cell map. Compiling data from multiple variations of rapid shotgun proteomics analyses is nonetheless useful to increase sequence coverage and confidence of hits especially for those proteins identified primarily by a single or two peptide matches. While the returned hit score in general reflects the abundance of the respective proteins, it is not a reliable index for differential expression. Using another closely related hepatoma Hep3B as a comparative basis, 16 proteins with more than two‐fold difference in expression level as defined by spot intensity in two‐dimensional gel electrophoresis analysis were identified which notably include members of the heat shock protein (Hsp) and heterogeneous nuclear ribonucleoprotein (hnRPN) families. The observed higher expression level of hnRNP A2/B1 and Hsp90 in Hep3B led to a search for reported functional roles mediated in concert by both these multifunctional cellular chaperones. In agreement with the proposed model for telomerase and telomere bound proteins in promoting their interactions, data was obtained which demonstrated that the expression proteomics data could be correlated with longer telomeric length in tumorigenic Hep3B. This biological significance constitutes the basis for further delineation of the dynamic interactions and modifications of the two protein families and demonstrated how proteomic and biological investigation could be mutually substantiated in a productive cycle of hypothesis and pattern driven research.
Analysis of proteins expressed in rat plasma exposed to dioxin using 2‐dimensional gel electrophoresis
Authors: Son Won‐Kyu , Lee Do‐Youn , Lee Sung‐Han , Joo Won‐A. , Kim Chan‐Wha
Published: December 2003

Dioxins are a class of polyhalogenated aromatic hydrocarbons that induces a wide spectrum of toxic responses in animals. In this study, two groups of Sprague‐Dawley rats were exposed to 2,3,7,8‐tetrachlorobenzo‐p‐dioxin (TCDD); one group received short‐term exposure at a single dose of 1, 10, 20 or 50 μg/kg body weight and the other received long‐term exposure to a daily low dose of 0.01, 0.1, 1 or 2.5 μg/kg body weight for one month. Two‐dimensional electrophoresis was utilized to resolve the protein profile of rat plasma exposed to TCDD at different doses. One novel and three volume‐increased spots were identified and characterized by matrix‐assisted laser desorption/ionization‐time of flight mass spectrometry and electrospray‐ionization on quadropole‐TOF2 mass spectrometry. The novel protein was identified as plasma glutathione peroxidase precursor and the volume‐increased proteins were cytokeratin 8 polypeptide, Ig lambda‐1 chain C region and Ig lambda‐2 chain C region. These proteins may be used as biomarkers to diagnose dioxin exposure and may help in understanding the toxic effects of dioxins.
Efficiency improvement of peptide identification for an organism without complete genome sequence, using expressed sequence tag database and tandem mass spectral data
Authors: Kwon Kyung‐Hoon , Kim Mioak , Kim Jin Young , Kim Kyung Wook , Kim Seung Il , Park Young Mok , Yoo Jong Shin
Published: December 2003

We compared peptide identification by database (DB) search methods with de novo sequencing results for proteomics study in an organism without genome sequence information. When the former was done by searching the Expressed Sequence Tag (EST) DB of the sample organism or the NCBI nonredundant (nr) protein DB of green plants using either the MASCOT or SEQUEST software program, it was confirmed that the former is as accurate as the latter. Peptides identified from EST DB were twice as many as those from the nr protein DB, in spite of the fact that the EST DB has less data (26 222 EST) than the NCBI nr protein DB (224 238). This study demonstrates that EST DB with tandem mass spectra can be used reliably for high‐throughput proteomics studies in an organism without genome information.
Proteomic profiling of heat shock protein 70 family members as biomarkers for hepatitis C virus‐related hepatocellular carcinoma
Authors: Takashima Motonari , Kuramitsu Yasuhiro , Yokoyama Yuuichiro , Iizuka Norio , Toda Toshifusa , Sakaida Isao , Okita Kiwamu , Oka Masaaki , Nakamura Kazuyuki
Published: December 2003

To identify proteins linked to the pathogenesis of hepatocellular carcinoma (HCC) associated with hepatitis C virus (HCV), we profiled protein expression levels in samples of HCC. To identify essential proteins, ten samples of HCV‐related HCC were analyzed by two‐dimensional gel electrophoresis and matrix‐assisted laser desorption/ionization‐time of flight mass spectrometry. These experiments revealed increased levels of nine proteins in cancerous tissues compared to levels in corresponding noncancerous liver tissues. We focused on four members of the heat shock protein 70 family: 78 kDa glucose‐regulated protein (GRP78), heat shock cognate 71 kDa protein (HSC70), 75 kDa glucose‐regulated protein (GRP75), and heat shock 70 kDa protein 1 (HSP70.1). These results were confirmed by immunoblot analysis. In an additional 11 samples, the same expression patterns of these four proteins were observed. In total, 21 samples showed statistically significant up‐regulation of GRP78, GRP75 and HSP70.1 in cancerous tissues. HSC70 showed a tendency toward overexpression. There has been no report describing overexpression of these four proteins simultaneously in HBV‐related HCC as well as nonviral HCC. Our results suggest that these four proteins play important roles in the pathogenesis of HCV‐related HCC and could be molecular targets for diagnosis and treatment of this disease.
Proteomic and transcriptomic analysis of interleukin‐1ß treated lung carcinoma cell line
Authors: Kim Chang‐Hoon , Kim Do Kyun , Choi Seung Jin , Choi Kun Ho , Song Kyoung Seob , Chi Janghoon , Koo Ja Seok , Hwang Seung Yong , Yoon Joo‐Heon , Seong Je Kyung
Published: December 2003

Mucin hypersecretion is one of the main symptoms of inflammatory disease in the respiratory tract. We previously reported that the pleiotypic pro‐inflammatory cytokine, interleukin (IL)‐1β, plays a significant role in respiratory tract inflammation by inducing mucins. However, the molecular mechanism for mucin hypersecretion in the respiratory tract remains still unclear. In order to understand the mechanisms of mucin hypersecretion in the airway epithelium, the differentially expressed proteins and genes in the lung mucoepidermoid carcinoma cell line (NCI‐H292 cells), which were treated for 6 and 24 hours with IL‐1β (10 ng/mL) were identified using two‐dimensional polyacrylamide gel electrophoresis (2‐D PAGE) proteomics and cDNA microarray analysis (8.6K). In the 2‐D PAGE, eight differentially expressed proteins and 14 post‐translational modification proteins were identified at 6 and 24 hours after the IL‐1β‐treatment. Four hundred and thirteen genes (6.6%) and 115 genes (2.0%) were differentially expressed, respectively, at 6 and 24 hours after the IL‐1β‐treatment by microarray analysis. The differentially expressed genes and proteins that were regulated by the IL‐1β‐treatment were mostly in the metabolic pathway rather than in the regulatory pathway. These results clearly show that the transcript levels have little value in predicting the extent of protein expression.
Shape transition of medium‐sized neutral silicon clusters
Authors: Sieck A. , Frauenheim Th. , Jackson K. A.
Published: December 2003

Addressing the shape transition of silicon clusters, indicated by mobility experiments on silicon cluster cations with 24 to 30 atoms, we investigate the structure of low energy neutral silicon clusters with 25, 29, and 35 atoms within a density‐functional based tight‐binding approach. Since there is strong evidence for several nearly degenerate low‐energy isomers for clusters of this size, we perform an extensive, but limited global search with Simulated Annealing and statistically analyze for each cluster size the 100 clusters with the lowest energy. We find different dominant shapes in the set of low energy clusters for each size. For neutral silicon clusters with 25 atoms, both prolate and spherical structures with low cohesive energies exist. For clusters containing 29 or 35 atoms, the low‐energy isomers exhibit a spherical shape. For each cluster size several stable isomers with similar shapes, and hence similar mobilities, but different bonding patterns exist. The most stable 25 atom cluster resulting from our global search has the lowest energy within DFT‐GGA known so far. Finally, we investigate the transition to diamond‐like bonding patterns expected for larger silicon clusters. Clusters with up to 239 atoms resemble amorphous silicon rather than the diamond structure and contain several highly coordinated atoms. (© 2003 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Metallic magnetoconductivity in copper gallium telluride
Authors: Essaleh L. , Galibert J. , Wasim S. M. , Marin G.
Published: December 2003

Low‐temperature magnetoresistance measurements, in the metallic regime, on p‐type CuGaTe2 were performed. The magnetoresistance results were analyzed using localization and electron–electron theories taking into account the effect of strong spin–orbit coupling. The results were compared to those related to CuInSe2. Good agreement of the experimental data with theory was found over a wide range of magnetic fields up to 20 T. From the theoretical fit, both the inelastic and spin–orbit relaxation times were estimated. (© 2003 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Structural, thermodynamic and other associated properties of partially ordered Ag‐In alloy
Authors: Venkatesh R. , Mishra Raj Kumar , Gopala Rao R. V.
Published: December 2003

Extensive computations have been performed using the Lebowitz solution of hard sphere mixtures as a reference system, and perturbed the hard sphere direct correlation function,COij(r), with square well attractive tail. We used mean spherical model to compute the total and partial direct correlation functions in the attractive and repulsive regions of the interacting potential of Ag–In alloy at different compositions. The potential parameters were those obtained for pure metals. With these potential parameters (the partial and total) structure factors were evaluated, and then Fourier transformed to get the partial and total radial distribution functions. Further the well‐known Bhatia–Thornton correlation functions namely the number‐number, concentration‐concentration, and number‐concentration correlation functions have been computed. We also obtained total and partial coordination numbers from partial and total pair correlation functions respectively. With the help of these pair correlation functions we give the distances between atoms namely Ag–Ag, In–In and Ag–In at different compositions of In in Ag–In alloy. It is found that these distances practically remain constant and are independent of composition, which has been attributed to the formation of segregated clusters of atomic dimensions. Using Kirkwood–Buff's equation, compressibillities have been calculated as a function of composition. The temperature derivative of diffusion coefficient for pure constituents has been formulated and the computed results were compared with the available experimental values. With this model the diffusion coefficients and the friction coefficients of the constituents have been obtained through the use of Helfand's trajectory principle with a reasonable success in the alloy as well. It is found that these metals of the alloy tend to segregate. The ratio of diffusion coefficients of the metals in the alloy is almost a constant and is equal to 0.9. This shows that the alloy forms a regular solution in spite of their tendency to segregate. (© 2003 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Many‐body and overlayer effects on surface optical properties
Authors: Bechstedt F. , Del Sole R. , Glutsch S. , Hahn P. H. , Pulci O. , Schmidt W. G.
Published: December 2003

We demonstrate the potential of recently developed total‐energy and electronic‐structure methods for the calculation of the optical properties of real surfaces. The many‐body effects are fully taken into account by a solution of the combined Dyson and Bethe‐Salpeter equations. We show that an initial‐value formulation of the polarization function allows an efficient numerical calculation of the optical susceptibility for large slabs consisting of many atoms. As examples we investigate GaP(001) and Si(001) surfaces covered by hydrogen. In the case of P‐rich GaP(001)2 × 2–H surfaces the low‐energy region of the reflectance anisotropy (RA) is dominated by electron–hole pair excitations in surface states. Surface‐induced modifications of bulk excitons near the E1 and E2 transitions are responsible for the RA of the monohydride Si(001)2 × 1–H surface. (© 2003 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)