bluuebunny/crossref_metadata_2025_split huggingface dataset:
A new quantitative method for circulating DNA level in human serum by capillary zone electrophoresis with laser‐induced fluorescence detection
Authors: Zhang Peng , Ren Jicun , Shen Zuojun 
Published: June 2004

AbstractWe present a method for the quantification of circulating DNA in serum by capillary zone electrophoresis (CZE) with laser‐induced fluorescence detection (LIF). The serum was digested by proteinase to release free DNA. SYBR Gold was utilized as DNA intercalating dye, fluorescein as internal standard (ISTD). CZE‐LIF was applied for the separation and quantification of total circulating DNA. Good linearity (R = 0.9992) in the low range of DNA concentrations (0.5–40 ng/mL) and a detection limit of 0.5 ng/mL for DNA (S/N = 3) were obtained. Our data demonstrated that CZE‐LIF system has a good linearity with excellent sensitivity and satisfactory reproducibility in the quantification of circulating DNA in serum. This method was successfully used for the quantification of circulating DNA levels in serum. We observed that the circulating DNA levels in certain cancer patients were significantly higher than that in healthy individuals. Compared to current methods, our protocol does not need the extraction of DNA from serum. Our preliminary results have illustrated that CZE‐LIF system is simple, rapid, and sensitive, and it is well suitable for large‐scale quantification of circulating DNA levels in clinical diagnosis.
Improved separation of palladium species in biological matrices by using a combination of gel permeation chromatography and isotachophoresis
Authors: Weber Günther , Messerschmidt Jürgen , von Bohlen Alex , Kastenholz Bernd , Günther Klaus 
Published: June 2004

AbstractThe binding of palladium to high‐molecular‐mass compounds in palladium‐treated lettuce is investigated as an example for a biological matrix. The total palladium concentration in lettuce leaves is 10.3 ng/g wet weight. After homogenization, high‐molecular‐mass compounds (> 10 kDa) are isolated by ultrafiltration. For separation of these palladium species a combination of preparative gel permeation chromatography (GPC) and preparative isotachophoresis (ITP) is used. Palladium is determined in separated fractions by using a highly sensitive total reflection X‐ray fluorescence (TXRF) method after preconcentration. After GPC separation, four main fractions of palladium species are collected, each containing palladium in ng quantities (3–10 ng). Two of these fractions are further separated by ITP, yielding at least three main peaks per GPC fraction, each containing palladium in the range of 0.3–3 ng. These palladium containing peaks are characterized by high‐performance size exclusion chromatography (HPSEC) and capillary isotachophoresis (cITP) in parallel. HPSEC enables the estimation of the molecular mass of six main palladium peaks, covering a molecular mass range of 69–200 kDa. It is also shown that the estimation of molecular mass after separation is more reliable than the respective estimation directly in the first GPC run. However, cITP reveals that each of the separated peaks is still a mixture of at least five different compounds.
Efficient separation and analysis of peroxisomal membrane proteins using free‐flow isoelectric focusing
Authors: Weber Gerhard , Islinger Markus , Weber Peter , Eckerskorn Christoph , Völkl Alfred 
Published: June 2004

AbstractWe have elaborated a protocol for the fractionation of both hydrophilic and hydrophobic proteins using as a model the matrix and membrane compartments of highly purified rat liver peroxisomes because of their distinct proteomes and characteristic composition with a high quota of basic proteins. To keep highly hydrophobic proteins in solution, an urea/thiourea/detergent mixture, as used in traditional gel‐based isoelectric focusing (IEF), was added to the electrophoresis buffer. Electrophoresis was conducted in the ProTeam free‐flow electrophoresis (FFE) apparatus of TECAN separating proteins into 96 fractions on a pH 3–12 gradient. Consecutive sodium dodecyl sulfate‐polyacrylamide gel electrophoresis (SDS‐PAGE) analysis demonstrated that both matrix and the integral membrane proteins of peroxisomes could be successfully fractionated and then identified by mass spectrometry. This is documented by the detection of PMP22, which is the most hydrophobic and basic protein of the peroxisomal membrane with a pI > 10. The identification of 96 prominent spots corresponding to polypeptides with different physical and chemical properties, e.g., the most abundant integral membrane polypeptides of peroxisomes and specific ones of the mitochondrial and microsomal membrane, reflects the fractionation potential of free‐flow (FF)‐IEF, accentuating its value in proteomic research as an alternative perhaps superior to gel‐based IEF.
Fast speciation analysis of iodophenol compounds in river waters by capillary electrophoresis‐inductively coupled plasma‐mass spectrometry with off‐line solid‐phase microextraction
Authors: Kannamkumarath Sasi S. , Wuilloud Rodolfo G. , Jayasinghe Sarath , Caruso Joseph A. 
Published: June 2004

AbstractAn analytical methodology for the fast separation and determination of iodophenol species in natural water samples was developed using capillary electrophoresis (CE) coupled to inductively coupled plasma‐mass spectrometry (ICP‐MS). Based on the element‐specific and highly sensitive detection provided by ICP‐MS, the methodology has been applied to the analysis of 2‐iodophenol, 4‐iodophenol, and 2,4,6‐triiodophenol. The use of solid‐phase microextraction (SPME), after proper optimization, improved the signal by a factor of 100 leading to detection limits in the sub μg·L−1. Different desorption conditions of iodophenol compounds from the SPME microfiber were studied to achieve the optimum preconcentration factor and best analytical performance. Different CE conditions were studied to achieve complete baseline separation of iodophenols in short migration times. Three different CE buffer systems were evaluated using ICP‐MS detection. A buffer solution containing 20 mmol·L−1 3‐(cyclohexylamino)‐1‐propanesulfonic acid (CAPS) and an applied potential of +22 kV were finally selected leading to a maximum separation time of 6.6 min. A relative standard deviation (%RSD) of about 5.0% for ten consecutive determinations was obtained. Finally, the speciation methodology developed was utilized for the determination of iodophenol compounds in natural water samples.
Effect of pressure on electrophoretic mobility of polystyrene latex particles
Authors: Sakakibara Akira , Kitagawa Shinya , Tsuda Takao 
Published: June 2004

AbstractA capillary electrophoresis system that can apply arbitrary helium gas pressures at both inlet and outlet reservoirs was constructed. The system was used to investigate the effect of pressure on electrophoretic behavior of polystyrene latex particles. The electrophoretic mobility of latex particles was increased with the application of pressure (< 3.0 kgf/cm2). The shrinkage of particle diameter under pressurization was observed using a microscope, however, the magnitude of shrinkage was not enough to explain the increase in electrophoretic mobility. Therefore, the application of pressure might increase the electric charge of the latex particle. Since methanol inhibited the enhancement in the electrophoretic mobility of the latex particles, water might play an important role in increasing mobility.
On‐line preconcentration for capillary electrophoresis‐atomic fluorescence spectrometric determination of arsenic compounds
Authors: Yin Xue‐Bo 
Published: June 2004

AbstractAn on‐line preconcentration method was developed for capillary electrophoresis (CE) with hydride generation‐atomic fluorescence spectrometric (HG‐AFS) detection of arsenite, arsenate, dimethylarsenic acid, and monomethylarsenic acid. These arsenic species were negatively charged in the sample solution with high pH. When the potential was applied to the electrophoretic capillary, the negatively charged analyte ions moved faster and stacked at the boundary of sample and CE buffer with low pH. So, high sample pH in combination with low buffer pH allowed the injection of large sample volumes (∼ 1100 nL). Comparison of the preconcentration of analyte solution, prepared with doubly deionized water and that prepared with lake or river water, indicated that preconcentration was independent on the original matrix. With injection of ∼1100 nL sample, an enrichment factor of 37–50‐fold was achieved for the four species. Detection limits for the four arsenic species ranged from 5.0 to 9.3 μg·L−1. Precisions (RSDs, n = 5) were in the range of 4.9–6.7% for migration time, 4.7–11% for peak area, and 4.3–7.1% for peak height, respectively. The recoveries of the four species in locally collected water solution spiked with 0.1 μg·mL−1 (as As) ranged from 83 to 109%.
Removal of phenolic compounds in pomegranate juices using ultrafiltration and laccase‐ultrafiltration combinations
Authors: Alper Neslihan , Acar Jale 
Published: June 2004

AbstractPhenolic compounds of fruit juices are responsible for haze and sediment formation as well as for color, bitterness and astringency. The influence of ultrafiltration (UF) and laccase‐UF combination was investigated on phenolic contents of pomegranate juices and on filtration output. Laccase‐treated and then ultrafiltered pomegranate juices have shown a rapid increase in their color, when compared to only ultrafiltered (control) samples. Kinetic parameters of laccase were also determined. During the oxidation period, the changes occurring in pomegranate juices were estimated from phenolic contents, color and anthocyanin measurements. Results have shown that laccase oxidation produced a significant decrease in phenolic content of pomegranate juices while juice color the increased. However, in recent literatures, the possibility to remove polyphenols in apple juices was reported. We decided in this study that laccase treatment can not be applied due to the loss of natural red color and unwanted dark brownish color formation in pomegranate juice.
Effect of γ‐radiation and microwave heating of wheat grain on some starch properties in irradiated grain as well as in grain of the next generation crops
Authors: Dolińska Romualda , Warchalewski Jerzy R. , Gralik Justyna , Jankowski Tomasz 
Published: June 2004

AbstractGrains of the Polish winter wheat variety Begra were subjected to γ‐radiation (grain harvested in 1996) within the dose range of 0.05–10 kGy and microwave heating (grain harvested in 1997) from 28°C to 98°C. Later the grains were divided into two parts, the first was used for direct analyses after treatment. The second part was sown on the experimental fields. The obtained crop was described as the first generation and divided into two parts. One part was destined to determination of starch properties and the second part was sown in order to obtain the second generation crop. The same pattern was conducted in order to achieve the third generation crop. γ‐Irradiation directly applied on the wheat grain reduced statistically significant falling number values and gelatinisation enthalpy (ΔH) of the grain treated by 5 and 10 kGy. Calculated linear regression correlation coefficient between the falling number values and the gelatinisation enthalpy was equal to 0.94 (p ⪇ 0.001) and showed that these two starch characteristics are well correlated in the case of directly irradiated wheat grain. The falling number values, peak temperatures (Tp) and gelatinisation enthalpy (ΔH), in three generations of wheat grain crop studied, did not show any statistically significant differences as a result of indirect effect of γ‐irradiation. Microwave direct heating of wheat grain to 98°C caused a statistically significant increase in the falling number value and decrease in starch gelatinisation power expressed by the enthalpy of gelatinisation (ΔH). The statistically significant changes in the falling number values, slight changes in the peak temperatures (Tp) and enthalpy of gelatinisation (ΔH) were found in all three generation crops as an indirect effect of microwave heating.
Antioxidant and angiotension‐converting enzyme inhibition capacities of various parts of Benincasa hispida (wax gourd)
Authors: Huang Hui‐Yu , Huang Ju‐Jen , Tso Tim K. , Tsai Ying‐Chieh , Chang Chen‐Kang 
Published: June 2004

AbstractVegetables and fruits have been shown to be good sources of antioxidants. Benincasa hispida (wax gourd) has been used in traditional Chinese medicine to treat hypertension and inflammation. The aims of this study were to investigate the abilities of antioxidation and inhibition of angiotensin‐converting enzyme (ACE) activity of wax gourd pulp, core, seed, and peel prepared by different extraction methods. The fresh weights required to reach 50% inhibition of linoleic acid oxidation were higher in fresh extracts, compared to other extraction methods. Fresh weights required to reach 50% inhibition were the lowest in seed. The seed had the lowest Cu2+‐induced low‐density lipoprotein (LDL) oxidation percentage and inhibition level of ACE activity among all parts. The higher antioxidant capacity of the seed may result from the higher total phenolics contents and superoxide dismutase activity. The abilities of antioxidation and ACE activity inhibition may provide protective effects against cardiovascular diseases and cancers.
Effect of γ‐irradiation on aflatoxin B1 production by Aspergillus flavus and chemical composition of three crop seeds
Authors: Aziz Nagy H. , Mahrous Souzan R. 
Published: June 2004

AbstractThe effect of γ‐irradiation on aflatoxin B1 production by Aspergillus flavus, and the chemical composition of some different crop seeds were investigated. A. flavus infected seeds behaved differently according to their principal constituents. A. flavus caused an increase in protein and decrease in lipids and carbohydrate contents of wheat, soyabean and fababean seeds. Growth of A. flavus and production of aflatoxin B1 was inhibited at a dose level of 5 kGy. A. flavus utilizes carbohydrates of seeds for its growth and aflatoxin production. Crops were arranged, in descending order, according to aflatoxin produced in seeds as wheat > soyabean > fababean. There were no changes in chemical constituents of irradiated seeds, such as protein, lipids, and carbohydrates.
Casein gelation under simultaneous action of transglutaminase and glucono‐δ‐lactone
Authors: Menéndez Orquídea , Schwarzenbolz Uwe , Rohm Harald , Henle Thomas 
Published: June 2004

AbstractCasein solutions (5% w/v) were treated with microbial transglutaminase (MTG) and glucono‐δ‐lactone (GDL) under varying conditions in order to obtain gels. Storage modulus (G ′) and gelation time of the gels were measured by oscillation rheometry, while protein cross‐linking was determined by gel permeation chromatography. The addition of only GDL to milk resulted in very weak gels, while MTG on its own was not able to create gel networks. Simultaneous action of both ingredients led to gels, the firmness of which was linearly related to the added amount of MTG, but passed through a maximum with rising GDL concentrations. Using chromatographical analysis, increasing G ′ values were interrelated with the formation of MTG‐induced oligomers. The gelation time was directly proportional to the GDL concentration but not influenced by the addition of MTG within the studied range of concentration.
Loss of chromosome arm 18q with tumor progression in head and neck squamous cancer
Authors: Takebayashi Satoru , Hickson Arthur , Ogawa Tetsuya , Jung Kwang‐Yoon , Mineta Hiroyuki , Ueda Yo , Grénman Reidar , Fisher Susan G. , Carey Thomas E. 
Published: June 2004

AbstractLoss of 18q was analyzed in 21 sets of head and neck squamous cell carcinoma (HNSCC) cell lines derived from primary and secondary tumors in the same patients. Only 3 of the 21 cell line pairs had no loss of 18q. In the remaining 18 sets, loss of heterozygosity (LOH) affecting 18q was found in either the primary or the secondary lines or both. In every case but one, the same chromosome was affected in both the primary and secondary cell lines. In 8 sets, the 18q loss occurred in the primary tumor and remained stable through the subsequent tumor progression. The primary and secondary lines differed in 18q loss in 10 of 18 (56%) cases with 18q LOH. In 3 of the 10 pairs that differed, 18q LOH was found in only the primary line, indicating that the loss developed after the metastatic or recurrent tumor population had diverged from the primary tumor population. In the other 7 pairs, 18q LOH developed or progressed with tumor recurrence or metastasis. Of these, 3 of 7 had 18q LOH in only the secondary lines, and 4 of 7 had 18q LOH in both the primary and secondary lines, but the extent of LOH was greater in the secondary lines than in the primary lines, indicating that additional rearrangements of the same chromosome occurred with progression. These cases showed that interstitial loss often progresses to consolidated loss in vivo. However, in vitro, the cell lines from the primary tumors with interstitial loss maintain those chromosomes over long‐term culture. LOH on 18q in cell lines from previously untreated primary tumors was significantly associated with advanced tumor stage (P = 0.0242) and decreased survival (P = 0.0453). The findings are consistent with the concept that 18q LOH is an event associated with tumor progression and suggest that inactivation and loss of one or more genes on 18q contributes to aggressive tumor behavior. © 2004 Wiley‐Liss, Inc.
The effect of fouling on nucleate pool boiling of small wires
Authors: Fukada Yusuke , Haze Ikuya , Osakabe Masahiro 
Published: June 2004

AbstractPool boiling experiments with small diameter wires were conducted in earth gravity and microgravity conditions. Bare wire and fouled wire with a scale deposition of calcium carbonate was used. The wettability on the scale wire was higher than that on the bare wire. Though more vigorous bubbling was observed on the scale wire when compared to that on the bare wire at the same heat flux, the boiling curve for the scale wire was approximately the same as that on the bare wire. However, the critical heat flux (CHF) on the scale wire was higher than that of the bare wire. On the scale wire, the departure diameter of bubbles was relatively smaller than that on the bare wire. The smaller diameter of bubbles detaching from the scale wire is considered to be due to the high wettability and high nucleation site density. As the result, the coalescence of bubbles near the wire was prevented, and the CHF was delayed and increased on the scale wire when compared to that on the bare wire. © 2004 Wiley Periodicals, Inc. Heat Trans Asian Res, 33(5): 316–329, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.20016
An experimental study of heat transfer enhancement with a pulsating flow
Authors: Jun Zheng , Danling Zeng , Ping Wang , Hong Gao 
Published: June 2004

AbstractA pulsating flow in a pipe was experimentally investigated to determine the effect of pulsation on the rate of heat transfer. The influence of hydrodynamic parameters and characteristics of the pulsation on heat transfer was carefully studied. In order to adjust the pulsating parameters, a self‐oscillator was designed so the length of the resonator and the length of the outlet nozzle could be adjusted. The results show that the heat transfer rate is strongly affected by both the hydrodynamic parameters and the configuration of the resonator. With the increase of the flow rate of the liquid and the length of the chamber, heat transfer is enhanced. There is an optimal length at which the heat transfer enhancement attends to the best. © 2004 Wiley Periodicals, Inc. Heat Trans Asian Res, 33(5): 279–286, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.20020
Lysophospholipid receptor‐dependent and ‐independent calcium signaling
Authors: Meyer zu Heringdorf Dagmar 
Published: June 2004

AbstractChanges in cellular Ca2+ concentrations form a ubiquitous signal regulating numerous processes such as fertilization, differentiation, proliferation, contraction, and secretion. The Ca2+ signal, highly organized in space and time, is generated by the cellular Ca2+ signaling toolkit. Lysophospholipids, such as sphingosine‐1‐phosphate (S1P), sphingosylphosphorylcholine (SPC), or lysophosphatidic acid (LPA) use this toolkit in a specific manner to initiate their cellular responses. Acting as agonists at G protein‐coupled receptors, S1P, SPC, and LPA increase the intracellular free Ca2+ concentration ([Ca2+]i) by using the classical, phospholipase C (PLC)‐dependent pathway as well as PLC‐independent pathways such as sphingosine kinase (SphK)/S1P. The S1P1 receptor, via protein kinase C, inhibits the [Ca2+]i transients caused by other receptors. Both S1P and SPC also act intracellularly to regulate [Ca2+]i. Intracellular S1P mobilizes Ca2+ in intact cells independently of G protein‐coupled S1P receptors, and Ca2+ signaling by many agonists requires SphK‐mediated S1P production. As shown for the FcεRI receptor, PLC and SphK may contribute specific components to the overall [Ca2+]i transient. Of the many open questions, identification of the intracellular S1P target site(s) appears to be of particular importance.
Thrombogenic and atherogenic activities of lysophosphatidic acid
Authors: Siess Wolfgang , Tigyi Gabor 
Published: June 2004

AbstractLysophosphatidic acid (LPA) has been identified as a biologically active lipid in mildly‐oxidized LDL, human atherosclerotic lesions, and the supernatant of activated platelets. The evidence that LPA has thrombogenic and atherogenic activities has increased substantially in recent years. Supporting the thrombogenic activity of LPA, analysis of the core region of human carotid plaques revealed recently the presence of alkyl‐ and acyl‐molecular species from LPA with high platelet‐activating potency (16:0 alkyl‐LPA, 20:4 acyl‐LPA). LPA, lipid extracts of atherosclerotic plaques, and the lipid‐rich core elicited shape change and, in synergy with other platelet stimuli, aggregation of isolated platelets. This effect was completely abrogated by prior incubation of platelets with LPA receptor antagonists. Furthermore, LPA at concentrations approaching those found in vivo, induced platelet shape change, aggregation, and platelet‐monocyte aggregate formation in blood. LPA‐stimulated platelet aggregation was mediated by the ADP‐stimulated activation of the P2Y1 and P2Y12 receptors. Supporting its atherogenic activity, LPA is a mitogen and motogen to vascular smooth muscle cells (VSMCs) and an activator of endothelial cells and macrophages. Recently, LPA has been identified as an agonist of the peroxisome proliferator activating receptor γ (PPARγ), which is a key regulator of atherogenesis. LPA elicits progressive neointima formation, which is fully abolished by GW9662, an antagonist of PPARγ. We propose that LPA plays a central role in eliciting vascular remodeling and atherogenesis. Furthermore, upon rupture of lipid‐rich atherosclerotic plaques, LPA may trigger platelet aggregation and intra‐arterial thrombus formation. Antagonists of LPA receptors might be useful in preventing LPA‐elicited thrombus formation and neointima formation in patients with cardiovascular diseases. © 2004 Wiley‐Liss, Inc.