bluuebunny/crossref_metadata_2025 huggingface dataset:
Hepatitis C virus screening and clinical monitoring of biomarkers in patients undergoing hemodialysis
Authors: Maia Laura Patrícia Viana , Martins‐Filho Olindo Assis , Teixeira‐Carvalho Andréa , Speziali Elaine , Vermhren Rolandro , Lira Edson Fonseca , Lima Tatiane Amabile , Braga Wornei Silva , Torres Kátia Luz , Malheiro Adriana
Published: May 2009

In this study, 395 volunteers were enrolled to investigate the seroprevalence of hepatitis C virus, the immunological and the alanine aminotransferase (ALT) biomarkers amongst hemodialysis patients, living in Manaus, Brazil. An overall seroprevalence of 13.9% was found in the hemodialysis patients. Analysis of seroconversion patterns demonstrated that most patients with HCV seroconverted up to 10 years following the first hemodialysis session. Anti‐NS5 antibody was detectable in 60.4% of patients with HCV. A lower percentage of circulating CD3+ and CD4+ T‐cells was found in patients seronegative for HCV, whereas a higher frequency of CD8+ T‐cells was the hallmark of patients with HCV. An overall low activation state of monocytes and eosinophils were observed in hemodialysis patients. In contrast, a higher frequency of activated neutrophils was observed in patients with HCV, selectively in the NS5+ subgroup. All hemodialysis patients had a higher percentage of activated lymphocytes, with the higher activation state in patients with NS5− reactivity. Higher ALT levels were observed in patients with HCV, especially in the NS5+ subgroup. Interestingly, the ALT levels were correlated negatively with the lymphocyte activation state, selectively in the NS5− subgroup, suggesting a protective role of these activated lymphocytes in patients with HCV. These findings reinforce the importance of the transmission of HCV among hemodialysis patients, suggesting that apart from the HCV screening, the serological and ALT biomarkers may represent important predictors of morbidity and/or mortality among patients undergoing hemodialysis. J. Med. Virol. 81:1220–1231, 2009. © 2009 Wiley‐Liss, Inc.
Aberrant expression of synaptic plasticity‐related genes in the NF1+/− mouse hippocampus
Authors: Park Chang Sin , Zhong Ling , Tang Shao‐Jun
Published: May 2009

Neurofibromatosis 1 (NF1) is a common single‐gene disorder that causes learning impairments in patients. Neurofibromin encoded by the NF1 causal gene regulates Ras/MAPK and cAMP signaling pathways. These signaling pathways play critical roles in controlling gene transcription during synaptic plasticity and memory formation. We hypothesized that NF1 mutations disturb the expression of genes important for memory formation. To test this hypothesis, we performed DNA microarray analysis on the hippocampus of NF1+/− mice, the mouse model for NF1 learning disabilities. Our results indicated that genes involved in a wide spectrum of biological processes are dysregulated in the NF1+/− hippocampus. Many of the NF1‐affected genes play critical roles in synaptic plasticity, such as Rabs, synaptotagmins, NMDAR1, CaMKII, and CREB1. Because NF1‐associated learning disabilities can be reversed by lovastatin, we also determined the effect of lovastatin treatment on genome‐wide expression patterns of the NF1+/− hippocampus. We found that lovastatin altered the expression of a large number of genes, including those disturbed by NF1 mutations. Our results reveal a genome‐wide overview of the molecular abnormalities in the NF1+/− hippocampus and should be useful for further identifying the novel molecular pathways that cause NF1 learning deficits. © 2009 Wiley‐Liss, Inc.
Cytokines decrease expression of interleukin‐6 signal transducer and leptin receptor in central nervous system glia
Authors: Rose Jason J. , Bealmear Beverly , Nedelkoska Liljana , Studzinski Diane , Lisak Robert P. , Benjamins Joyce A.
Published: May 2009

Multiple sclerosis (MS) lesion formation is modulated by cytokines secreted within the central nervous system (CNS). Th1 lymphocytes and monocyte/macrophages (MM) likely induce lesion formation, whereas Th2 lymphocytes may inhibit formation. To explore the role of cytokines in MS lesions, we used gene arrays to investigate effects of cytokines representative of Th1 and Th2 cells and M/M on gene expression in cultured CNS glia; at 6 hr, all three increased expression of the interleukin‐6 (IL‐6) gene and decreased expression of the leptin receptor gene (obr), which mediates IL‐6 production and other inflammatory responses. However, expression of a closely related gene, the interleukin‐6 signal transducer or gp130 (IL‐6st), showed no changes at 6 hr. IL‐6st is an essential component of receptor complexes for IL‐6 and other cytokines and growth factors that play critical roles in CNS inflammation, protection, and/or regeneration. To analyze expression of IL‐6st and leptin receptor over time, we incubated rat CNS glial cultures for 6 hr to 5 days with the cytokines. All three cytokine mixtures down‐regulated both IL‐6st and leptin receptor mRNA and protein for up to 5 days. Immunocytochemical staining showed expression of both IL‐6st and leptin receptor in all three types of glia, with lower IL‐6st expression by 3 days. Down‐regulation of IL‐6st and leptin receptor in glia by cytokines could lead to decreased signaling by the proinflammatory IL‐6 and reduced responses to regenerative/protective growth factors such as leukemia inhibitory factor and ciliary neurotrophic factor, potentially affecting the disease course in MS. © 2009 Wiley‐Liss, Inc.
Oxidative stress disrupts oligodendrocyte maturation
Authors: French Heather Morein , Reid Mary , Mamontov Polina , Simmons Rebecca A. , Grinspan Judith B.
Published: May 2009

Periventricular white matter injury (PWMI) is the leading cause of chronic neurologic injury among survivors of preterm birth. The hallmark of PWMI is hypomyelination and a lack of mature, myelinating oligodendrocytes. Oligodendrocytes undergo a well‐characterized lineage progression from neural stem cell to mature oligodendrocyte. Oligodendrocyte precursors have increased susceptibility to oxidative and free radical‐mediated injury compared with mature oligodendrocytes as a result of lower levels of antioxidant enzymes and free radical scavengers. In this study, we show that oxidative stress disrupts oligodendrocyte differentiation by two mechanisms. First, oxidizing agents decrease the expression of key genes that promote oligodendrocyte differentiation from neural stem cells and increase the expression of genes known to inhibit differentiation. Second, global histone acetylation persists under conditions of oxidative stress, further contributing to the prevention of oligodendrocyte differentiation. Both of these mechanisms result in the arrest of oligodendrocyte differentiation without an increase in cell death. © 2009 Wiley‐Liss, Inc.
Toward culture‐sensitive theories of the work–family interface
Authors: Powell Gary N. , Francesco Anne Marie , Ling Yan
Published: May 2009

Due to societal trends, managing the work–family interface has become an increasingly challenging task for employees in virtually every nation. However, prior studies of this interface have mostly tested U.S.‐based theories using U.S. samples. The construct of societal or national culture, which seems likely to shape individuals' experiences of the work–family interface, has been generally unacknowledged in theories and research in the work–family literature. In this paper, we offer guidelines for the development of culture‐sensitive theories of work–family phenomena and for research to test such theories as they are developed. First, we review the few prior research attempts that have incorporated cultural considerations in some manner and identify cultural dimensions that are likely to influence the work–family interface. Second, we demonstrate how selected cultural dimensions may be incorporated into theories of work–family conflict and enrichment, two constructs that represent the negative and positive side of the work–family interface respectively, to make these theories more culture‐sensitive. Finally, we offer an ambitious agenda for future theory and research to increase understanding of cultural influences on the work–family interface. Copyright © 2009 John Wiley & Sons, Ltd.
The influence of organizational democracy on employees' socio‐moral climate and prosocial behavioral orientations
Authors: Weber Wolfgang G. , Unterrainer Christine , Schmid Birgit E.
Published: May 2009

This study investigates the effects of workers' perceived participation in democratic decision‐making on their prosocial behavioral orientations, democratic values, commitment to the firm, and perceptions of socio‐moral climate. The sample consists of 325 German‐speaking employees from 22 companies in Austria, North Italy, and Southern Germany that vary in their level of organizational democracy (social partnership enterprises, workers' co‐operatives, democratic reform enterprises, and employee‐owned self‐governed firms). The findings suggest that the extent employees participate in democratic forms of organizational decision‐making is positively related to the firm's socio‐moral climate as well as to their own organizational commitment and prosocial and community‐related behavioral orientations. The results also indicate that socio‐moral climate is positively related to employees' organizational commitment. The effect of participation in decision‐making on organizational commitment is partially mediated by socio‐moral climate. Implications for promoting societal and organizational civic virtues among individuals are described. Copyright © 2009 John Wiley & Sons, Ltd.
Regional variation in perceptions about climate change
Authors: Hamilton Lawrence C. , Keim Barry D.
Published: May 2009

A 2007 survey covering rural areas in nine US states provides data on perceived local impacts of climate change. Perceptions vary from region to region, with a pattern suggesting links to real climate—specifically to winter warming in snow country. A multivariate analysis using mixed‐effects ordered logit regression confirms a significant perception‐temperature relationship, net of individual background and ideological characteristics, and of regional variations. These findings invite more detailed research. Copyright © 2009 Royal Meteorological Society
The sea‐level conundrum: case studies from palaeo‐archives
Authors:   PALSEA,   (PALeo SEA level working group)
Published: May 2009

Uncertainties in sea‐level projections for the 21st century have focused ice sheet modelling efforts to include the processes that are thought to be contributing to the recently observed rapid changes at ice sheet margins. This effort is still in its infancy, however, leaving us unable to make reliable predictions of ice sheet responses to a warming climate if such glacier accelerations were to increase in size and frequency. The geological record, however, has long identified examples of nonlinear ice sheet response to climate forcing (Shackleton NJ, Opdyke ND. 1973. Oxygen isotope and paleomagnetic stratigraphy of equatorial Pacific core V28–239, late Pliocene to latest Pleistocene. Geological Society of America Memoirs 145: 449–464; Fairbanks RG. 1989. A 17,000 year glacio‐eustatic sea level record: influence of glacial melting rates on the Younger Dryas event and deep ocean circulation. Nature 342: 637–642; Bard E, Hamelin B, Arnold M, Montaggioni L, Cabioch G, Faure G, Rougerie F. 1996. Sea level record from Tahiti corals and the timing of deglacial meltwater discharge. Nature 382: 241–244), thus suggesting an alternative strategy for constraining the rate and magnitude of sea‐level change that we might expect by the end of this century. Copyright © 2009 John Wiley & Sons, Ltd.
Vibrational spectroscopic studies of the structure of di‐amino acid peptides. Part II: cyclo(L‐Asp‐L‐Asp) in the solid state and in aqueous solution
Authors: Mendham Andrew P. , Dines Trevor J. , Withnall Robert , Mitchell John C. , Chowdhry Babur Z.
Published: May 2009

Solid‐state protonated and N,O‐deuterated Fourier transform infrared (IR) and Raman scattering spectra together with the protonated and deuterated Raman spectra in aqueous solution of the cyclic di‐amino acid peptide cyclo(L‐Asp‐L‐Asp) are reported. Vibrational band assignments have been made on the basis of comparisons with previously cited literature values for diketopiperazine (DKP) derivatives and normal coordinate analyses for both the protonated and deuterated species based upon DFT calculations at the B3‐LYP/cc‐pVDZ level of the isolated molecule in the gas phase. The calculated minimum energy structure for cyclo(L‐Asp‐L‐Asp), assuming C2 symmetry, predicts a boat conformation for the DKP ring with both the two L‐aspartyl side chains being folded slightly above the ring. The CO stretching vibrations have been assigned for the side‐chain carboxylic acid group (e.g. at 1693 and 1670 cm−1 in the Raman spectrum) and the cis amide I bands (e.g. at 1660 cm−1 in the Raman spectrum). The presence of two bands for the carboxylic acid CO stretching modes in the solid‐state Raman spectrum can be accounted for by factor group splitting of the two nonequivalent molecules in a crystallographic unit cell. The cis amide II band is observed at 1489 cm−1 in the solid‐state Raman spectrum, which is in agreement with results for cyclic di‐amino acid peptide molecules examined previously in the solid state, where the DKP ring adopts a boat conformation. Additionally, it also appears that as the molecular mass of the substituent on the Cα atom is increased, the amide II band wavenumber decreases to below 1500 cm−1; this may be a consequence of increased strain on the DKP ring. The cis amide II Raman band is characterized by its relatively small deuterium shift (29 cm−1), which indicates that this band has a smaller NH bending contribution than the trans amide II vibrational band observed for linear peptides. Copyright © 2009 John Wiley & Sons, Ltd.
Raman scattering investigation of selenomethionine replacement in protein SOUL crystals
Authors: Rossi B. , Mariotto G. , Ambrosi E. , Monaco H. L.
Published: May 2009

The vibrational properties of both wild‐type and selenomethionine (SeMet)‐substituted protein SOUL crystals have been investigated here by Raman spectroscopy. Several Raman peaks observed in the spectra of methionine and SeMet were identified as specific markers. The unambiguous assignment of these peaks has been inferred by comparing the experimental Raman spectra of the pure amino acids, recorded in solid state and in aqueous solution, and the Raman intensities computed using quantum chemical calculations. Moreover, a quantitative evaluation of the relative amount of SeMet replacement in the crystals of protein SOUL labelled with SeMet has been estimated through the ratio between the Raman intensities of marker peaks. These results offer evidence of the potential of Raman microscopy as a reliable and non‐invasive tool for novel in‐depth structural investigations in biocrystallography. Copyright © 2009 John Wiley & Sons, Ltd.
Appropriate selection of patients for combined organ resection in cases of gastric carcinoma invading adjacent organs
Authors: Jeong Oh , Choi Won Yong , Park Young Kyu
Published: May 2009

Background and Objectives

Proper patient selection for multi‐organ resection in T4 gastric carcinoma remains controversial. Our aim was to investigate which patients might benefit from multi‐organ resection.

Methods

Among 1,775 consecutive patients receiving gastric cancer surgery, 71 had adjacent organ invasion. Short‐ and long‐term surgical outcomes and associations between clinicopathological factors and overall survival were investigated.

Results

Forty‐seven patients underwent curative surgery with multi‐organ resection, and 24 underwent non‐curative surgery, with or without multi‐organ resection. Postoperative morbidity and mortality rates were 31.7% and 3.3%, respectively. Patients receiving curative surgery via multi‐organ resection survived longer than those without (MST, 31.5 months vs. 19.1 months, P = 0.046). Multi‐organ resection did not affect survival when performed in non‐curative surgery. N3 lymph node metastasis was an independent prognostic factor for poor outcome (HR = 3.89, 95% CI = 1.40–10.83) in curatively resected patients; patients with N3 lymph node metastasis showed similar survival to patients receiving non‐curative surgery.

Conclusion

Multi‐organ resection should be performed only when no incurable factors are present, and R0 resection is most likely. Multi‐organ organ resection does not, however, seem to be effective in patients with N3 lymph node metastasis, even when curative resection is performed. J. Surg. Oncol. 2009;100:115–120. © 2009 Wiley‐Liss, Inc.
Prognostic impact of lymphatic invasion in patients with node‐negative gastric cancer
Authors: Ichikawa Daisuke , Kubota Takeshi , Kikuchi Shojiro , Fujiwara Hitoshi , Konishi Hirotaka , Tsujiura Masahiro , Ikoma Hisashi , Nakanishi Masayoshi , Okamoto Kazuma , Sakakura Chohei , Ochiai Toshiya , Kokuba Yukihito , Otsuji Eigo
Published: May 2009

Background and Objectives

This study investigated the prognostic impact of lymphatic invasion on the outcome of patients with node‐negative gastric cancer.

Methods

A total of 828 patients with node‐negative gastric cancer who underwent curative gastretomy were reviewed retrospectively. The clinicopathological features and prognoses of patients with lymphatic invasion were compared to those of patients without such invasion.

Results

The total rate of lymphatic invasion was 18.2% in node‐negative gastric cancers, with a significant difference between early gastric cancers (9.8%) and advanced gastric cancers (49.2%). The presence of lymphatic invasion correlated significantly with tumor location, size and depth of tumor (P < 0.01). Lymphatic invasion was significantly associated with a poorer overall survival in node‐negative gastric cancer patients on univariate analysis (P < 0.001) as well as multivariate analysis (P < 0.01).

Conclusions

Lymphatic invasion provides additional useful information that could be applied to identify patients at high risk for recurrence who might be candidates for adjuvant therapies in patients with node‐negative gastric cancers. J. Surg. Oncol. 2009;100:111–114. © 2009 Wiley‐Liss, Inc.
Polymer monolith microextraction online coupled to hydrophilic interaction chromatography/mass spectrometry for analysis of β2‐agonist in human urine
Authors: Zheng Ming‐Ming , Zhang Man‐Yu , Feng Yu‐Qi
Published: May 2009

An analytical method based on online combination of polymer monolith microextraction (PMME) technique with hydrophilic interaction LC (HILIC)/MS is presented. The extraction was performed with a poly(methacrylic acid‐co‐ethylene glycol dimethacrylate) monolithic column while the subsequent separation was carried out on a Luna silica column by HILIC. After 1:1 v/v dilution with 20 mM phosphate solution at pH 7.0 and centrifugation, urine sample was directly used for extraction. After optimization, 85% ACN (containing 0.3% formic acid v/v) was used for rapid online elution, which was also the mobile phase in HILIC to avoid band broadening during separation or carry‐over that was usually observed in PMME‐RP LC system. Online automation of extraction and separation procedures was realized under the control of a program in this study. The developed method was applied to rapid and sensitive monitoring of three β2‐agonist traces in human urine. The LODs (S/N = 3) of the method were found to be 0.05–0.09 ng/mL of β2‐agonists in urine. The recoveries of three β2‐agonists spiked in five different urine samples ranged from 79.8 to 119.8%, with RSDs less than 18.0%.
Pilot‐scale ion‐exchange centrifugal partition chromatography: Purification of sinalbin from white mustard seeds
Authors: Toribio Alix , Nuzillard Jean‐Marc , Pinel Benoît , Boudesocque Leslie , Lafosse Michel , De La Poype François , Renault Jean‐Hugues
Published: May 2009

The purification of p‐hydroxybenzylglucosinolate (sinalbin) on a multigram scale from a crude aqueous extract of white mustard seeds (Sinapis alba var. concerta) was successfully achieved by scaling up a strong ion‐exchange centrifugal partition chromatography (SIXCPC) laboratory procedure. Thus, the one‐step sinalbin purification was performed with 2.35 g of crude extract in ˜170 min (830 mg/h) up to 70.3 g in ˜160 min (26.3 g/h) by switching from a 200 mL laboratory scale column to a 5.7 L pilot‐scale column. The required biphasic solvent system contained ethyl acetate, n‐butanol, and water in 3:2:5 v/v/v proportions, Aliquat 336® (trioctylmethyl ammonium chloride) was added to the organic stationary phase (80 mM) and acted as ion‐exchanger. Potassium iodide in the aqueous mobile phase (80 mM) was used as sinalbin displacer. The 28.5 mass scale factor arose from the increase in mobile phase flow‐rate (from 2 to 50 mL/min), from the higher mass of injected white mustard seed extract (from 12 to 350 g), and from the calculated productivity (from 830 mg to 26.3 g). These results demonstrate that industry scale production of glucosinolates is easily performed by SIXCPC, thus providing pure reference standards for pharmacology studies.
Two‐dimensional RPLC‐RPLC system with different pH in two dimensions for separation of alkaloids from Corydalis yanhusuo W. T. Wang
Authors: Zhang Jing , Jin Yu , Liu Yanfang , Xiao Yuansheng , Feng Jiatao , Xue Xingya , Zhang Xiuli , Liang Xinmiao
Published: May 2009

An effective method utilizing the same RP chromatographic column with different pH in first and second LC dimensions has been developed for separation of the basic compounds from traditional Chinese medicines (TCMs). In this work, the alkaloids in Corydalis yanhusuo which is an important TCM were selected as a model to develop the method. The additives and pH values of the mobile phase were optimized in this work. To investigate the feasibility of this method, off‐line mode separation was performed in the experiments. According to the UV‐absorption intensity, there were eight fractions collected in acidic conditions. All the fractions were analyzed in basic conditions. The results showed that the chromatographic selectivities were significantly different in the separations performed with acidic and alkaline elution systems. Complementary separation was achieved in this work. It is demonstrated that this method would be an effective tool for alkaloids research. Based on the different pH of the mobile phase in this method, it could also be suitable to analyze compounds which were sensible to the pH of the solution.
Multivariate approach for the enantioselective analysis in MEKC‐MS: II. Optimization of 1,1′‐binaphthyl‐2,2′‐diamine in positive ion mode
Authors: He Jun , Shamsi Shahab A.
Published: May 2009

Enantiomeric separation and detection of 1,1′‐binaphthyl‐2,2′‐diamine (BNA) has been successfully optimized by MEKC‐ESI‐MS using a polymeric surfactant polysodium N‐undecenoxycarbonyl‐L‐leucinate (poly‐L‐SUCL) as a pseudostationary phase. In the first step, MEKC conditions were optimized by a five‐factor three‐level central composite design (CCD) of experiment. All five MEKC factors (buffer pH, percentage of ACN in the running buffer, concentration of surfactant, concentration of ammonium acetate (NH4OAc), and voltage) were found significant to the responses (measured as the chiral resolution and analysis time). The interactions between MEKC factors were further evaluated using a quadratic model equation which allowed the generation of 3‐D response surface image to reach the optimum conditions. To obtain the best S/N, sheath liquid composition and spray chamber parameters were successfully optimized using the same strategy. Baseline enantiomeric resolution in less than 20 min and optimum MS signal of BNA enantiomers (S/N = 45 at 0.4 mg/mL) were ultimately achieved at the optimized conditions. The adequacy of the model was validated by experimental runs at the optimal predicted conditions. The predicted results were found to be in good agreement with the experimental data.
Enantioseparation of chiral benzimidazole derivatives by electrokinetic chromatography using sulfated cyclodextrins
Authors: Lipka Emmanuelle , Charton Julie , Vaccher Marie‐Pierre , Folly‐Klan Marcia , Bonte Jean‐Paul , Vaccher Claude
Published: May 2009

Baseline separation of 18 new substituted benzimidazole derivatives, potent AMP‐activated protein kinase (AMPK) activators, with one chiral center, was achieved by CD‐EKC using sulfated and highly sulfated CDs (SCDs and HS‐CDs) as chiral selectors. The influence of the type and concentration of the chiral selectors on the enantioseparations was investigated. The SCDs exhibit a very high enantioselectivity power since they allow excellent enantiomeric resolutions compared to those obtained with the neutral CDs. The enantiomers were resolved with analysis times around 6 min using 25 mM phosphate buffer at pH 2.5 containing either β‐S‐CD, HS‐β‐CD, HS‐γ‐CD (3 or 4% w/v) at 25°C, with a voltage of 20 kV. The apparent association constants of the inclusion complexes were calculated. The study of the solute structure‐enantioseparation relationships seems to show the high contribution of the interactions between the solutes phenyl ring and the CDs to the enantiorecognition process. The optimized method was briefly validated (LOD less than 1%) and the purity of enantiomers of compound 3 was determined. The enantiomer migration shows reversal order depending on the kind of CD.
Separation of structural, geometrical and optical isomers of epoxycarotenoids using triacontyl‐bonded stationary phases
Authors: Meléndez‐Martínez Antonio J. , Escudero‐Gilete Maria L. , Vicario Isabel M. , Heredia Francisco J.
Published: May 2009

The efficiency of C30 stationary phases in the separation of carotenes and diverse hydroxycarotenoids has been the subject of several studies. However, little is known concerning their ability to resolve epoxycarotenoids isomers, whose study is of great importance due to the functions they serve and the information they can reveal concerning the processing of foods. We have concluded that C30 columns provide an excellent separation of structural, geometrical and optical isomers of epoxycarotenoids and that the presence of 5,8‐epoxide groups leads to a better shape recognition, to the extent that over 10 geometrical–optical isomers of 5,8‐epoxycarotenoids have been separated. Additionally, it was observed that these carotenoids elute later than their 5,6‐epoxide counterparts, albeit the latter have a longer chromophore.
Peptide inhibitor modified magnetic particles for pepsin separation
Authors: Filuszová Michaela , Kučerová Zdenka , Tichá Marie
Published: May 2009

Synthetic heptapeptide containing D‐amino acid residues (Val‐D‐Leu‐Pro‐Phe‐Phe‐Val‐D‐Leu) was coupled to glyoxal‐activated magnetic agarose particles via the free peptide amino group. The peptide‐modified magnetic particles were used for the separation of pepsins. Porcine pepsin A and human pepsin A were adsorbed to the magnetic peptide‐modified affinity carrier, while the rat pepsin C and human pepsin C did not interact with the immobilized ligand. Conditions of pepsin adsorption to peptide‐modified magnetic particles, as well as elution buffers were optimized. Porcine pepsin A did not interact with the immobilized peptide in the presence of pepsin inhibitor pepstatin A, indicating that the enzyme binding site is involved in the studied interaction. The elaborated method represents a rapid and simple technique not only for the separation of pepsins but also, in combination with MS, for the enzyme detection and determination.
Quantification of fenfluramine with a molecularly imprinted chemiluminescence sensor and sulfonophenylazo rhodanine
Authors: Yu Jinghua , Dai Ping , Wan Fuwei , Li Bo , Ge Shenguang
Published: May 2009

Fenfluramine‐imprinted polymer was prepared by self assembly with acrylic amide as functional monomer and ethylene glycol dimethacrylate as crosslinker. The binding characteristics of the imprinted polymer to fenfluramine were evaluated by equilibrium binding experiments and the morphology was studied by SEM. Taking the imprinted polymer as recognition material, using the new 3‐p‐nitrylphenyl‐5‐(4′‐methyl‐2′‐sulfonophenylazo)rhodanine (M4NRASP) synthesized by the authors as chemiluminescence reagent, a new highly selective flow injection chemiluminescence sensor for trace fenfluramine with good sensitivity was established which utilized the chemiluminescence reaction between fenfluramine, M4NRASP, and potassium permanganate in hydrochloric acid. The traditional flow‐through cell was replaced with a polymethyl methacrylate module, with Y‐shaped flow path, through which the above three reactants were injected simultaneously. Under optimum conditions the relative chemiluminescence intensity shows a linear relationship with the concentration of fenfluramine over the range of 5×10–7 to 8×10–6 g/mL with a lower detection limit of 3.4×10–8 g/mL. The relative standard deviation for the determination of 1.0×10–6 g/mL fenfluramine solution was 2.4% (n = 11). This proposed sensor could be satisfactorily applied to the determination of fenfluramine in weight‐reducing capsules.
Theoretical and experimental investigations on relationship between Kohlrausch regulating function/inequality and moving reaction boundary in electrophoresis
Authors: Zhang Wei , Jin Jie , Fan Liu‐Yin , Li Si , Shao Jing , Cao Cheng‐Xi
Published: May 2009

Kohlrausch regulating function (KRF) has been well defined from a moving boundary system for over 50 years. Recently, a series of theoretical and experimental studies were carried out on the concept of moving reaction boundary (MRB), including moving precipitate boundary, moving neutralization boundary and moving chelation boundaries (MCB). However, there has not been any direct evidence to show whether the KRF has validity for a MRB or not. In this paper, the KRF is derived from the equation of MRB under condition of nonzero boundary velocity. The result directly shows the relation between the KRF and a MRB. The relation is verified by some experimental and simulation results on MCB and moving neutralization boundary as well as Svensson's classic IEF. Furthermore, a Kohlrausch inequality was defined from the equation of MRB and was further proved by numerous data. The results show that we can use the KRF for the investigation on a MRB under the condition of nonzero boundary velocity, whereas we ought to notice with great attention that the KRF does possibly have invalidity under some special cases, such as stationary electrolysis and IEF. The findings hold an evident significance to the study of a MRB with the KRF.
Homogeneous liquid–liquid extraction combined with high performance liquid chromatography–fluorescence detection for determination of polycyclic aromatic hydrocarbons in vegetables
Authors: Zhao Xinna , Liu Xiujuan , Zhao Zhixu , Huang Changjiang , Zhang Minghua , Wang Huili , Wang Xuedong
Published: May 2009

In this article, homogeneous liquid–liquid extraction (HOLLE), combined with HPLC‐fluorescence detector (HPLC‐FLD), has been developed for the extraction and determination of polycyclic aromatic hydrocarbons (PAHs) in vegetables. ACN was used as extraction solvent for the extraction of target analytes from vegetables. When the previous extraction process was over, the ACN extract was transferred to the water‐immiscible organic phase, tetrachloroethane, used as extraction solvent in HOLLE procedures. Under the optimum conditions, repeatability was carried out by spiking PAHs at concentration level of 12.5 μg/kg, the RSDs varied between 1.1 and 8.5% (n = 3). The LODs, based on S/N of 3, ranged from 0.025 to 0.25 μg/kg. Relative recoveries of PAHs from cucumber and long crooked squash samples were in the range of 72.4–104.9% and 65.5–119.3%, respectively. Compared with the conventional extraction method, the proposed method has the advantage of being quick, easy to operate, and having low consumption of organic solvent.
Quantitative analysis of ezetimibe in human plasma by gas chromatography‐mass spectrometry
Authors: Uçaktürk Ebru , Özaltin Nuran , Kaya Baris
Published: May 2009

A new, specific and sensitive GC‐MS method with electron impact ionization technique was developed for quantitative analysis of ezetimibe (EZE) in human plasma. Prior to GC analysis, EZE was derivatized with N‐methyl‐N‐trimethylsilyl‐trifluoroacetamide (MSTFA), which is a trimethyl silylating reagent. The derivatization reaction was optimized and parameters such as catalyst, derivatization time, temperature, solvent and the volume of silylating reagent were investigated. Trimethylsilyl ether derivative of EZE was determined in selected ion monitoring (SIM, mass‐to‐charge ratio (m/z): 326) mode. The method was validated with respect to LOD and LOQ, precision, accuracy, linearity, specificity, stability, and recovery. The LOQ and LOD were found as 15 and 10 ng/mL, respectively. The linearity of the method ranged from 15 to 250 ng/mL. The correlation coefficient of the calibration curve was 0.9977 ± 0.0004 (± S.E.M.). The intra‐ and inter‐day precisions (RSD) were less than 6% and accuracies (bias) for intra‐ and inter‐day accuracy were found between –4.04 and 9.71% at four different concentration levels (15, 40, 100, 250 ng/mL). The proposed method was successfully applied to real human plasma samples for determination of total EZE.
The acetonitrile shortage: Is reversed HILIC with water an alternative for the analysis of highly polar ionizable solutes?
Authors: dos Santos Pereira Alberto , David Frank , Vanhoenacker Gerd , Sandra Pat
Published: May 2009

In hydrophilic interaction chromatography (HILIC), best results are obtained with high concentrations of ACN. In the framework of green chromatography and the present shortage and very high price of this hazardous solvent, reversing the stationary phase to apolar and the mobile phase to aqueous can be of interest for several applications. The features of the aqueous RP technique called per aqueous LC (PALC) are illustrated with the analysis of catecholamines, nucleobases, acids, and amino acids. The ca. three‐fold higher viscosity of water compared to ACN has consequences on the shape of the Van Deemter plot. For dopamine (N = 26.450 on a 25 cm×4.6 mm id, 5 μm bare silica column), a reduced plate height of 1.9 at an uopt of 0.3 mm/s was calculated. The plate number, however, strongly depends on pH and ionic strength. As in RP separations, retention is shortened by adding an organic modifier. In the framework of green chromatography, the biodegradable ethanol was used. On the other hand, retention increased by lengthening the carbon chain of ion‐pair reagents supporting the RP mechanism as well.
Behavioral predictors of acute stress symptoms during intense military training
Authors: Taylor Marcus K. , Mujica‐Parodi Lilianne R. , Padilla Genieleah A. , Markham Amanda E. , Potterat Eric G. , Momen Nausheen , Sander Todd C. , Larson Gerald E.
Published: May 2009

A better understanding of factors influencing human responses to acute stress is needed to enhance prevention and treatment of stress‐related disorders. In the current study, the authors examined predictors of acute stress symptoms during intense military training in 35 men. In univariate and multivariate models, perceived stress, passive coping, and emotion‐focused coping during daily living predicted acute stress symptoms in response to realistic survival training, whereas active coping and problem‐focused coping did not. Baseline stress levels and coping styles, both of which may be modifiable, appear to play a fundamental role in the human response to acute uncontrollable stress. Additional research is needed to better elucidate the relative and interactive contributions of behavioral predictors of acute stress.
CO2 Laser – Workhorse for Industrial Manufacturing
Authors: Rath Wolfram
Published: May 2009

For more than 30 years lasers are used for industrial production with high success. Modern efficient production would not be imaginable without lasers and laser processes. Since the beginning days CO2 lasers were dominating the market of continuous cutting and welding applications (referred here as “Macro” applications) because of their high power and electrical efficiency, reliability and cost efficiency.
High Power Diode Lasers and Current Applications
Authors: Wolff Detlev , Stolberg Klaus , Zühlke Hans‐Ulrich
Published: May 2009

In the recent years diode lasers have been established in many areas of industry and research. Especially the pumping of solid state lasers (DPSSL) is major field of application for high power diode lasers enabling solutions in many laser micro processes like cutting, sintering, structuring as well as drilling. This article reports progresses in the past as well as state of the art of high power diode lasers and describes their major applications.
Fiber Lasers Conquer the Industrial Mainstream Market
Authors: Norman Steve , Appleyard Andrew
Published: May 2009

Fiber lasers have been extensively deployed in advanced manufacturing applications such as precision cutting, marking, micromachining, rapid prototyping and high‐quality printing; their advantanges in terms of beam quality, dynamic range, wall‐plug efficiency, reliability and cost are well recognised. New degrees of operational freedom can often be achieved enabling major improvements in capability and/or competitiveness for end users. In some sectors (e.g. marking), fiber lasers have become the solution of choice and already take the predominant market share for new equipment investments. Their performance and operational advantages have led to widespread deployment, both geographically and in diverse applications. This market acceptance has led to several of the major industrial laser manufacturers entering the market with their own fiber laser products.
Economic Downturn Hits Laser Market at Record High
Authors: Mayer Arnold
Published: May 2009

The world market for laser materials processing systems grew by 1 % in 2008 and reached a new all time high of 6.4 billion Euro. The increase was due to a strong first half of the year, which overcompensated a decrease in the second half. The economic downturn in the wake of the financial crisis started to impact orders for laser systems in spring 2008, and hit sales in the third and fourth quarter. The decrease of sales continued in the first quarter of 2009. Based on the data for the first quarter, the 2009 the market is expected to be substantially below its 2008 level.
Wear rate testing in relation to airborne particles generated in a wheel–rail contact
Authors: Sundh Jon , Olofsson Ulf , Olander Lars , Jansson Anders
Published: May 2009

This study examines the relationship between generated airborne particles and wear rate in the wheel–rail contact. The wheel–rail contact is experimentally simulated by using pin‐on‐disc testing to determine the difference in wear rate between selected contact conditions.

Wear is discussed both in tribological terms and by using the wear categories prevalent in the railway industry, namely, mild, severe and catastrophic wear. The discussion is based on wear depth, the coefficient of friction, topographical measurements and measurements of airborne particles generated in the contact.

The tests were performed under selected loading conditions representative of different contact conditions in a real wheel–rail contact. The results indicate that wear rates vary with the contact conditions arising from different types of triggered wear transitions. This is emphasised by the number and size of the airborne particles generated. Copyright © 2009 John Wiley & Sons, Ltd.
The Utilization of Liver Transplantation in the Management of Acute Liver Failure: Comparison Between Acetaminophen and Non-Acetaminophen Etiologies
Authors: Simpson Kenneth J. , Bates Caroline M. , Henderson Neil C. , Wigmore Stephen J. , Garden James O. , Lee Alistair , Pollok Antony , Masterton George , Hayes Peter C.
Published: May 2009

Abstract

Liver transplantation (LT) may be life-saving in severe acute liver failure (ALF). The aim of this study was to compare the utilization of LT in acetaminophen and non-acetaminophen ALF. Between 1992 and 2006, 469 patients with ALF were admitted, and 104 underwent LT. Acetaminophen was the most common etiology, but LT proceeded more frequently in the non-acetaminophen cohort (acetaminophen: 45/326 patients received LT, 13.8%; non-acetaminophen: 59/143 patients received LT, 41.3%; P < 0.01). A retrospective analysis of the individual steps in the management of patients revealed more ALF patients in the non-acetaminophen cohort fulfilled the King's College Hospital poor prognostic criteria (non-acetaminophen: 91/143, 63.6%; acetaminophen: 165/326, 50.6%; P < 0.01), more patients had contraindications to LT in the acetaminophen cohort (acetaminophen: 99/165, 60%; non-acetaminophen: 21/91, 23.1%; P < 0.01), and survival on the LT waiting list was reduced in the acetaminophen cohort (acetaminophen: 45/66, 68.2%; non-acetaminophen: 59/70, 84.3%; P < 0.05). Post-LT survival was similar in the 2 groups. An analysis of cohorts admitted in 1993-1996 and 2002-2005 revealed that LT proceeded less commonly in acetaminophen ALF in the later cohort (1993-1996: 16/99 LT, 16.2%; 2002-2005: 4/81 LT, 5%; P < 0.01) in comparison with the non-acetaminophen cohort, in which transplantation proceeded more commonly in the later cohort (1993-1996: 11/34 LT, 32.4%; 2002-2005: 24/49 patients, 49.0%; P < 0.01). This was due to an increase in the number of patients with psychiatric contraindications to transplantation (predominantly resistant and severe alcohol dependence). In conclusion, at all decision steps between admission and emergency LT, LT is favored in non-acetaminophen patients, and nonoperative management is favored in acetaminophen ALF patients. Liver Transpl 15:600–609, 2009. © 2009 AASLD.
Changes in the Serum Levels of Interleukin-17/Interleukin-23 During Acute Rejection in Liver Transplantation
Authors: Fábrega Emilio , López-Hoyos Marcos , San Segundo David , Casafont Fernando , Pons-Romero Fernando
Published: May 2009

Abstract

Interleukin-23 (IL-23) and T helper 17 (Th17) cells have been cast as major players in autoimmunity, but their role in transplantation immunity remains to be specified. The aim of our study was to investigate the time course of serum levels of IL-23 and IL-17 during hepatic allograft rejection. Serum levels of IL-23 and IL-17 were determined in 20 healthy subjects and 50 hepatic transplant recipients. These patients were divided into 2 groups: group I was composed of 15 patients with acute rejection, and group II was composed of 35 patients without acute rejection. Samples were collected on days 1 and 7 after liver transplantation and on the day of liver biopsy. The concentrations of IL-23 were similar for the rejection group and nonrejection group at early postoperative times. We observed a significant increase in serum IL-23 levels in the rejection group when a diagnosis of acute rejection had been established. Similarly to IL-23, at the diagnosis of acute rejection, the concentration of IL-17 was significantly higher in the rejection group versus the nonrejection group. The whole transplant group, including those with stable graft function, had higher serum levels of IL-23 and IL-17 than the controls during the entire postoperative period. In conclusion, IL-23 and IL-17 are up-regulated during acute hepatic rejection. These findings suggest a role for Th17 cells in human liver allograft rejection. Liver Transpl 15:629–633, 2009. © 2009 AASLD.
Graft Rejection Occurring in Post–Liver Transplant Patients Receiving Cytotoxic Chemotherapy: A Case Series
Authors: Tan Hui-Hui , Fiel Isabel M. , del Rio Martin Juan , Schiano Thomas D.
Published: May 2009

Abstract

Liver transplant recipients are known to be at increased risk for the development of de novo neoplasms or the recurrence of preexisting malignancies, and this is possibly related to the use of immunosuppressive medication. Little is known about the effects of cytotoxic chemotherapy on graft function after transplantation. A retrospective chart and pathology database review was undertaken to identify post–liver transplant patients developing rejection during chemotherapy. All liver biopsies were reviewed by a hepatopathologist. Three patients were identified. All patients were diagnosed with cancer within 7 years of liver transplantation; two-thirds died soon after the diagnosis of malignancy. Rejection occurred soon after chemotherapy was started. All patients were receiving prednisone and tacrolimus (trough levels: 2.1-4.8 ng/mL). One patient developed plasma cell hepatitis (de novo autoimmune hepatitis). There was no histologic evidence of hepatotoxicity due to the chemotherapeutic agents. Cytotoxic chemotherapy should be used in liver transplant recipients with caution, and immunosuppressant doses should be maintained at therapeutic levels, as patients may be at risk for allograft rejection. Treatment of rejection or plasma cell hepatitis in this setting should be undertaken in a timely and aggressive fashion to prevent chronic ductopenic rejection. Liver Transpl 15:634–639, 2009. © 2009 AASLD.
Long-Term Follow-Up of Donor Chimerism and Tolerance After Human Liver Transplantation
Authors: Ayala Rosa , Grande Silvia , Albizua Enriqueta , Crooke Almudena , Meneu Juan Carlos , Moreno Almudena , Pérez Baltasar , Gilsanz Florinda , Moreno Enrique , Martínez-Lopez Joaquín
Published: May 2009

Abstract

We aimed to quantify peripheral donor chimerism (DC) and to analyze its association with graft and recipient outcome. Forty-two liver transplant recipients and their respective donors were studied, providing a total of 148 posttransplantation serum samples. DC was assessed with real-time quantitative polymerase chain reaction (qPCR) to detect polymorphic markers. DC did not decrease with time post-transplantation and was higher in child recipients versus adults and in recipients of deceased donor liver transplants versus recipients of live donor liver transplants. Higher levels of DC were detected in Rh-positive blood group donors, in O blood group recipients versus A blood group recipients, and in recipients with hepatitis C virus versus recipients with alcoholic cirrhosis. High DC was associated with patients with organ damage due to recurrent disease and rejection. Stable, high levels of DC, in the absence of other major clinical events, may thus be a marker of transplantation tolerance, and this knowledge may help to tailor immunosuppressive treatment. In conclusion, qPCR is a useful technique for DC follow-up in liver transplantation, although the evolution of DC levels should be analyzed in accordance with the clinical outcome of the patient. Liver Transpl 15:581–591, 2009. © 2009 AASLD.
Critical chloride content for reinforced concrete and its relationship to concrete resistivity
Authors: Polder R. B.
Published: May 2009

The critical chloride content for initiation of reinforcement corrosion is an essential element in service life design and modelling of concrete structures. The critical content is laden with questions regarding its definition, experimental assessment and practical aspects. It should be addressed by a statistical approach. The paper discusses such issues, presents experimental evidence and considers its relationship to the electrical resistivity of concrete. A low concrete resistivity can be theoretically argued to relate to a low critical chloride content. However, only part of the experimental data supports this. The resolution of available data does not allow distinction with regard to the critical content between cement types.