bluuebunny/crossref_metadata_2025 huggingface dataset:
High‐throughput tissue microarray analysis of 11q13 gene amplification (CCND1, FGF3, FGF4, EMS1) in urinary bladder cancer
Authors: Zaharieva Boriana M , Simon Ronald , Diener Pierre‐Andre , Ackermann Daniel , Maurer Robert , Alund Göran , Knönagel Hartmut , Rist Marcus , Wilber Kim , Hering Franz , Schönenberger Andreas , Flury Renata , Jäger Peter , Fehr Jean Luc , Mihatsch Michael J , Gasser Thomas , Sauter Guido , Toncheva Draga I
Published: December 2003

Gene amplification is a common mechanism for oncogene overexpression. High‐level amplifications at 11q13 have been repeatedly found in bladder cancer by comparative genomic hybridization (CGH) and other techniques. Putitative candidate oncogenes located in this region are CCND1 (PRAD1, bcl‐1), EMS1, FGF3 (Int‐2), and FGF4 (hst1, hstf1). To evaluate the involvement of these genes in bladder cancer, a tissue microarray (TMA) containing 2317 samples was screened by fluorescence in situ hybridization (FISH). The frequency of gains and amplifications of all genes increased significantly from stage pTa to pT1–4 and from low to high grade. In addition, amplification was associated with patient survival and progression of pT1 tumours. Among 123 tumours with amplifications, 68.3% showed amplification of all four genes; 19.5% amplification of CCND1, FGF4, and FGF3; and 0.8% co‐amplification of FGF4, FGF3, and EMS1. Amplification of CCND1 alone was found in 9% of the tumours, while EMS1 alone was amplified in 1.6% and FGF4 in 0.8%. Overall, the amplification frequency decreased with increasing genomic distance from CCND1, suggesting that, among the genes examined, CCND1 is the major target gene in the 11q13 amplicon in bladder cancer. Copyright © 2003 John Wiley & Sons, Ltd.
Productive infection of dendritic cells by simian immunodeficiency virus in macaque intestinal tissues
Authors: Choi Yang Kyu , Whelton Kelly M , Mlechick Brandy , Murphey‐Corb Michael A , Reinhart Todd A
Published: December 2003

Dendritic cells (DCs) are potent antigen‐presenting cells that likely play multiple roles in human immunodeficiency virus‐1 (HIV‐1) and simian immunodeficiency virus (SIV) pathogenesis. This paper describes the effects of pathogenic SIV infection on the networks of DCs in rhesus macaque (Macaca mulatta) intestinal tissues. Intestinal tissues were obtained from macaques at different stages of disease following infection with the pathogenic SIV/DeltaB670 isolate. The patterns and levels of expression of SIV and DC‐associated mRNAs were examined and quantitated directly in intestinal tissue sections. In situ hybridization was performed for SIV, DC‐specific ICAM3‐grabbing non‐integrin (DC‐SIGN), DC‐specific lysosome‐associated membrane glycoprotein (DC‐LAMP), DC‐specific C‐type lectin 1 (DECTIN‐1), CC chemokine receptor 6 (CCR6), CCR7, and macrophage inflammatory protein 3α (MIP‐3α/CCL20) mRNAs and quantitative image analysis was performed to measure mRNA expression levels. To identify the cell types productively infected by SIV, simultaneous in situ hybridization and immunohistochemical staining were performed. The DC networks in macaque intestinal tissues were found to be extensive and although they generally remained intact during the course of SIV infection, there were alterations in the expression of markers for immature DCs. One alteration was an increase in the expression in intestinal submucosa of DC‐SIGN, a molecule that binds to HIV‐1/SIV and increases its infectivity. Concomitant with this increase, it was found that during AIDS, the population of productively infected cells included DCs, based on co‐expression of DC‐SIGN and DECTIN‐1 mRNAs. These data indicate that SIV infection affects subpopulations of macaque intestinal DCs, including productive infection of DC‐SIGN+ DCs, the consequences of which are likely to be ongoing viral propagation and decreased immunostimulatory function. Copyright © 2003 John Wiley & Sons, Ltd.
Primary breast myoepithelial cells exert an invasion‐suppressor effect on breast cancer cells via paracrine down‐regulation of MMP expression in fibroblasts and tumour cells
Authors: Jones JL , Shaw JA , Pringle JH , Walker RA
Published: December 2003

In normal breast and ductal carcinoma in situ, myoepithelial cells form an incomplete layer separating the epithelial compartment from the stromal environment. Transition to invasive disease is marked by penetration of the myoepithelial–basement membrane (BM) interface. One mechanism involved in tumour invasion is breakdown of extracellular matrices by matrix metalloproteinases (MMPs). It was hypothesized that myoepithelial cells may modulate tumour invasion by controlling MMP gene expression, both in tumour cells and in peri‐ductal fibroblasts. To investigate this, myoepithelial cells from normal breast were purified and characterized and their effect on tumour cell invasive potential was assessed. The effect on MMP gene expression of breast cancer cells cultured alone or in combination with primary normal breast fibroblasts was also analysed using RT‐PCR with ELISA quantitation, with zymographic analysis to measure enzyme activity. Normal breast myoepithelial cells significantly reduced invasion by the breast cancer cell lines MCF‐7, T47D, MDA‐MB 231, and MDA‐MB 468 when they were cultured alone or in the presence of a fibroblast population. Reduced invasion was associated with changes in MMP gene expression. In those tumour cells expressing MMP, there was a significant down‐regulation of MMP‐2 (MDA‐MB 468, p < 0.001), MMP‐9 (MDA‐MB 231, p = 0.05; MDA‐MB 468, p < 0.001), and MT1‐MMP (p < 0.001 for both MDA‐MB 231 and MDA‐MB 468). Myoepithelial cells also caused a significant decrease in MMP gene expression in co‐cultured fibroblasts. Furthermore, this was associated with reduced gelatinolytic activity as identified by zymography. This study demonstrates for the first time that primary myoepithelial cells from normal breast reduce breast cancer cell invasion and that this is mediated via modulation of both tumour cell and fibroblast function. This emphasizes the importance of the myoepithelial cell in controlling the breast microenvironment and focuses on the potential significance of the loss of this population with disease progression. Copyright © 2003 John Wiley & Sons, Ltd.
Altered expression of the septin gene, SEPT9, in ovarian neoplasia
Authors: Burrows James F , Chanduloy Severine , McIlhatton Michael A , Nagar Hans , Yeates Karen , Donaghy Paul , Price John , Godwin Andrew K , Johnston Patrick G , Russell SE Hilary
Published: December 2003

The septin family of genes has been implicated in a variety of cellular processes including cytokinesis, membrane transport and fusion, exocytosis, and apoptosis. One member of the septin family maps to chromosome 17q25.3, a region commonly deleted in sporadic ovarian and breast tumours, and has also been identified as a fusion partner of MLL in acute myeloid leukaemias. The present study demonstrates that the pattern of expression of multiple splice variants of this septin gene is altered in ovarian tumours and cell lines. In particular, expression of the zeta transcript is detectable in the majority of tumours and cell lines, but not in a range of non‐malignant adult and fetal tissues. Zeta expression is accompanied by loss of the ubiquitous beta transcript. Somatic mutations of the gene were not detected in ovarian tumours, but it was demonstrated that beta expression in tumour cell lines can be reactivated by 5‐azacytidine treatment, suggesting a role for methylation in the control of expression of this gene. Copyright © 2003 John Wiley & Sons, Ltd.
Expression of the cell death genes BNip3 and NIX in ductal carcinoma in situ of the breast; correlation of BNip3 levels with necrosis and grade
Authors: Sowter Heidi Michelle , Ferguson Mary , Pym Caroline , Watson Peter , Fox Stephen B , Han Cheng , Harris Adrian L
Published: December 2003

Ductal carcinoma in situ (DCIS) of the breast is an early, non‐invasive lesion and the prognosis is associated with the extent of necrosis and cell death within the tumour. Two cell death genes, BNip3 and NIX, are up‐regulated in response to hypoxia in breast carcinoma cells, although any involvement of either gene in disease progression is currently unknown. This study has analysed the expression of BNip3 and NIX in 56 samples of breast DCIS, as well as in adjacent benign and invasive breast tissue. Both genes are strongly expressed in the epithelial component of a subset of DCIS and invasive disease. The data show a correlation between high expression of BNip3 in the DCIS cells and a high‐grade, necrotic lesion that is likely to be associated with invasive tumour. BNip3 was present in tumour‐associated macrophages and in apocrine metaplastic lesions. Expression of NIX did not correlate with any of the parameters investigated Copyright © 2003 John Wiley & Sons, Ltd.
Long‐term infection with Helicobacter felis and inactivation of the tumour suppressor gene p53 cumulatively enhance the gastric mutation frequency in Big Blue® transgenic mice
Authors: Jenks Peter J , Jeremy Anthony HT , Robinson Philip A , Walker Marjorie M , Crabtree Jean E
Published: December 2003

The aims of this study were to determine whether colonization with Helicobacter felis resulted in the accumulation of mutations within murine gastric tissue and whether the degree of genetic damage was increased by p53 deficiency. Female C57BL/6 mice carrying either the lambda/lacI transgene (Big Blue® transgenic mice) or the lambda/lacI transgene and deficient in one allele of the p53 tumour suppressor gene (TSG‐p53®/Big Blue®) were inoculated with H felis. Seven months after inoculation, mutations in the target lacI gene were assessed using the Big Blue® transgenic mutagenesis assay system in these animals and in controls. There was an approximately two‐fold increase in lacI mutations in gastric mucosa harvested from mice infected with H felis and also from non‐infected mice heterozygous for the p53 allele relative to wild‐type mice. The mutation frequency in mice infected with H felis and deficient in one allele of p53 was increased approximately three‐fold. Active gastric inflammation was significantly greater in H felis‐infected p53 hemizygous mice compared with H felis p53 wild‐type mice. Gastric epithelial proliferation was similarly increased with infection in both of these latter groups of mice. In infected mice, there was a significant correlation between the mutation frequency and the degree of active gastric inflammation. These data suggest a synergistic action between infection with H felis and p53 deficiency in the accumulation of mutations within gastric tissue. Active neutrophil infiltration in gastric Helicobacter infection may contribute to the increased levels of mutation observed. Copyright © 2003 John Wiley & Sons, Ltd.
The patterns of relapse in osteosarcoma: The memorial Sloan‐Kettering experience
Authors: Chi Susan N. , Conklin Laurie S. , Qin Jing , Meyers Paul A. , Huvos Andrew G. , Healey John H. , Gorlick Richard
Published: December 2003

Background

With the introduction of intensive high‐dose chemotherapy for the treatment of osteosarcoma, changes in the pattern of metastases observed at relapse have been reported. To further investigate this hypothesis, the relapse patterns among groups receiving chemotherapy regimens of variable intensity at Memorial Sloan‐Kettering Cancer Center were analyzed.

Procedure

All patients treated with the protocols T4, T5, T7, T10, and T12 were included. Patients were divided into two groups, one including those patients treated with less intense therapy (T4, T5, and T7) and the other, those treated with current regimens (T10 and T12).

Results

Of the 25 patients who relapsed on the earlier protocols, 76% relapsed to the lungs, 8% had local recurrences, and 16% distant metastases to the bone. The median time to first relapse was 12 months. Of the 69 patients who relapsed on the T10 and T12 protocols, 75% relapsed in the lungs, 9% had local recurrences, and 16% distant bone metastases. The median time to first relapse was 17 months. There was no statistically significant difference in the timing of relapse between the two groups studied, although a longer median time to relapse was observed for patients treated on the later protocols. The range of time to relapse was also wider in the later protocols.

Conclusions

These data do not support the hypothesis that patterns of relapse are changing with alterations in osteosarcoma treatment. This limited single institutional experience can be explored further in the context of a multi‐institutional effort. © 2003 Wiley‐Liss, Inc.
Stature of young people with malignant bone tumors
Authors: Cotterill Simon J. , Wright Charlotte M. , Pearce Mark S. , Craft Alan W.
Published: December 2003

Background

Little is known about the aetiology of primary bone tumours. There have been conflicting reports relating to stature in young people with bone cancer.

Patients

We analysed height data at diagnosis for 364 patients with osteosarcoma and 356 patients with Ewing sarcoma registered on clinical trials run by the Medical Research Council (MRC) and the United Kingdom Children's Cancer Study Group (UKCCSG).

Main Outcome Measures

Height at diagnosis for each patient was standardised for age and sex compared to national reference data with a standard deviation score (SDS) calculated for each subject.

Results

Those with osteosarcoma were significantly taller than the general population (mean height SDS 0.2, P = 0.001). Patients with osteosarcoma of the femur were significantly taller than patients with other primary sites (mean height SDS 0.45 vs. −0.06, P = 0.0001). Overall those with Ewing sarcoma were not significantly taller than the general population (mean height SDS 0.09, P = 0.1), but children presenting under 15 years were taller (SDS 0.2, P = 0.004) whilst older patients were not (SDS −0.07, P = 0.4). In both osteosarcoma and Ewing sarcoma the mean age at diagnosis for females was significantly younger than for males.

Conclusions

This study suggests that tall stature and an earlier pubertal growth spurt may be important factors in the aetiology of both osteosarcoma and Ewing sarcoma. © 2003 Wiley‐Liss, Inc.
Phase I study of oral cyclophosphamide and oral topotecan for children with recurrent or refractory solid tumors
Authors: Bowers Daniel C. , Aquino Victor M. , Leavey Patrick J. , Bash Robert O. , Journeycake Janna M. , Tomlinson Gail , Mulne Arlynn F. , Haynes Heidi J. , Winick Naomi J.
Published: December 2003

Background

To determine the maximum‐tolerated duration and dose‐limiting toxicity of a daily schedule of orally administered cyclophosphamide and topotecan in pediatric patients with recurrent or refractory malignant solid tumors.

Methods

Patients received oral cyclophosphamide (50 mg/m2/dose) in the morning followed by topotecan (0.8 mg/m2/dose) 8–12 hr later for an escalating number of consecutive days (10, 14, and 17 days).

Results

Seventeen pediatric patients were treated with oral cyclophosphamide and topotecan for durations of 10–17 days for a total of 58 treatment courses. Reversible hematologic toxicity (neutropenia and thrombocytopenia) was the dose‐limiting toxicity. Nonhematologic toxicities of greater than grade 3 were not observed. A partial response (neuroblastoma following myeloablative chemotherapy and stem cell rescue) and prolonged stable disease (medulloblastoma) were each observed in one patient.

Conclusions

The recommended duration of therapy with a daily schedule of both oral cyclophosphamide (50 mg/m2/day) and topotecan (0.8 mg/m2/day) for previously treated pediatric patients with recurrent or refractory solid tumors is 14 consecutive days. The observed dose limiting toxicity (DLT) was reversible neutropenia. This regimen was well tolerated in heavily pretreated patients and demonstrated activity against recurrent pediatric solid tumors. © 2003 Wiley‐Liss, Inc.
Outcome of children with high‐risk acute lymphoblastic leukemia (HR‐ALL): Nordic results on an intensive regimen with restricted central nervous system irradiation
Authors: Saarinen‐Pihkala Ulla M. , Gustafsson G. , Carlsen N. , Flaegstad T. , Forestier E. , Glomstein A. , Kristinsson J. , Lanning M. , Schroeder H. , Mellander L.
Published: December 2003

Background

Improvement in outcome of childhood high‐risk (HR) ALL was sought with a very intensive Nordic protocol leaving most patients without CNS‐RT.

Methods

A total of 426 consecutive children entered the NOPHO‐92 HR‐ALL program. HR criteria included WBC ≥ 50 × 109/L, CNS or testicular involvement, T‐cell, lymphomatous features, t(9;22), t(4;11), or slow response. Of these, 152 children had very high risk (VHR) with special definitions. CNS consolidation was based on high‐dose MTX (8 g/m2) and ARA‐C (12 g/m2) alternating. VHR patients also received cranial RT.

Results

The 9‐year EFS was 61 ± 3%, OS 74 ± 2%, and EFS for T‐ALL 62 ± 4%. Cumulative incidence of isolated CNS relapse was 4.7 ± 1%, and CNS relapse in total 9.9 ± 2%. Poor prognostic factors were WBC ≥ 200 × 109/L and a very slow response.

Conclusions

HR‐ALL was successfully treated on the NOPHO‐92 regimen, with a relatively low CNS relapse rate for non‐irradiated children. WBC ≥ 200 × 109/L and very slow response emerged as strong poor prognostic factors. © 2003 Wiley‐Liss, Inc.
Investigation on Brill transition of nylons 6/16, 4/16 and 2/16 by variable‐temperature WAXD and FTIR
Authors: Li Weihua , Huang Yue , Zhang Guosheng , Yan Deyue
Published: December 2003

Brill transition behaviour of nylons 6/16, 4/16 and 2/16 has been studied systematically by variable‐temperature wide‐angle X‐ray diffraction (WAXD) and real‐time FTIR. It is shown that all nylons investigated undergo Brill transitions before melting on heating. Brill temperatures detected by real‐time FTIR are consistent with the results of variable‐temperature WAXD measurements. In addition, Brill bands were identified based on real‐time IR spectra and further consideration of —NH— groups provided additional information for discussing the mechanism of the crystalline transition. Copyright © 2003 Society of Chemical Industry
Bistability of propagating front with spin‐mode in a frontal polymerization of trimethylopropane triacrylate
Authors: Huh Do Sung , Kim Hye Sook
Published: December 2003

We have studied a nonlinear dynamic behaviour in a frontal polymerization process. Frontal polymerization is a mode of converting a monomer into a polymer via a localized reaction zone that propagates as a front. Interest in studying the dynamic behaviour of such propagating fronts is growing. Many studies focus on the spin‐mode front propagation characterized by a nonplanar front having one or more high temperature regions which move in a helical path along the axis of the reaction vessel. In this study, the bistable character of the spin‐mode induced by reaction vessel diameter has been analyzed. First, a reactor with a discontinuously varying diameter for preliminary tests, and second, a conical reactor with a continuously varying diameter have been used. We have obtained evidence of bistability of the spin‐mode front in the frontal polymerization of trimethylopropane triacrylate under certain reaction conditions. Copyright © 2003 Society of Chemical Industry
Evaporation behaviour of water and its plasticizing effect in modified poly(vinyl alcohol) systems
Authors: Wang Ru , Wang Qi , Li Li
Published: December 2003

Several modified poly(vinyl alcohol) (PVA) systems with various plasticizers were prepared and their melt‐processing was successfully realized. This paper focuses on the study of the evaporation behaviour of water in these modified PVA systems, exploring its plasticizing mechanism by using differential scanning calorimetry. The evaporation characteristics of bulk water, water in aqueous solutions of the plasticizers, and the thermal properties of PVA were also studied. The experimental results show that water in aqueous solutions of glycerol and/or caprolactam evaporates at a lower temperature than bulk water, but water in the PVA/water system evaporates at a higher temperature, with a wider DSC peak due to the interaction between water and PVA. Incorporation of glycerol, caprolactam or their mixtures further strengthens the interactions between water and the other components, retarding water evaporation. During the processing, the less closely associated water has the plasticizing effect through molecule movement, while the strongly bound water, which breaks the intermolecular hydrogen bonding of PVA and decreases its intermolecular interaction, is more beneficial to the melt‐processing of PVA. Copyright © 2003 Society of Chemical Industry
Dielectric relaxation analysis of starch oligomers and polymers with respect to their chain length
Authors: Meißner Dana , Einfeldt Jürgen
Published: December 2003

Starch belongs to the polyglucan group. This type of polysaccharide shows a broad β‐relaxation process in dielectric spectra at low temperatures, which has its molecular origin in orientational motions of sugar rings via glucosidic linkages. This chain dynamic was investigated for α(1,4)‐linked starch oligomers with well‐defined chain lengths of 2, 3, 4, 6, and 7 anhydroglucose units (AGUs) and for α(1,4)‐polyglucans with average degrees of polymerization of 5, 10, 56, 70, and so forth (up to 3000; calculated from the mean molecular weight). The activation energy (Ea) of the segmental chain motion was lowest for dimeric maltose (Ea = 49.4 ± 1.3 kJ/mol), and this was followed by passage through a maximum at a degree of polymerization of 6 (Ea = 60.8 ± 1.8 kJ/mol). Subsequently, Ea leveled off at a value of about 52 ± 1.5 kJ/mol for chains containing more than 100 repeating units. The results were compared with the values of cellulose‐like oligomers and polymers bearing a β(1,4)‐linkage. Interestingly, the shape of the Ea dependency on the chain length of the molecules was qualitatively the same for both systems, whereas quantitatively the starch‐like substances generally showed higher Ea values. Additionally, and for comparison, three cyclodextrins were measured by dielectric relaxation spectroscopy. The ringlike molecules, with 6, 7, and 8 α(1,4)‐linked AGUs, showed moderately different types of dielectric spectra. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 188–197, 2004
Electrospinning of ultrafine cellulose acetate fibers: Studies of a new solvent system and deacetylation of ultrafine cellulose acetate fibers
Authors: Son Won Keun , Youk Ji Ho , Lee Taek Seung , Park Won Ho
Published: December 2003

Electrospinning of cellulose acetate (CA) in a new solvent system and the deacetylation of the resulting ultrafine CA fibers were investigated. Ultrafine CA fibers (∼2.3 μm) were successfully prepared via electrospinning of CA in a mixed solvent of acetone/water at water contents of 10–15 wt %, and more ultrafine CA fibers (0.46 μm) were produced under basic pH conditions. Ultrafine cellulose fibers were regenerated from the homogeneous deacetylation of ultrafine CA fibers in KOH/ethanol. It was very rapid and completed within 20 min. The crystal structure, thermal properties, and morphology of ultrafine CA fibers were changed according to the degree of deacetylation, finally to those of pure cellulose, but the nonwoven fibrous mat structure was maintained. The activation energy for the deacetylation of ultrafine CA fibers was 10.3 kcal/mol. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 5–11, 2004
Determination of the degree of cure under dynamic and isothermal curing conditions with electrical impedance spectroscopy
Authors: Skordos Alexandros A. , Partridge Ivana K.
Published: December 2003

This article presents a new methodology for the quantitative determination of the progress of the curing reaction of a thermosetting resin, using the results of electrical impedance spectroscopy. The method is an extension of the use of the imaginary impedance maximum as a reaction progress indicator and is based on the demonstration of a close correlation between the reaction rate, as measured by conventional differential scanning calorimetry, and the rate of change of the value of the imaginary impedance spectrum maximum. Tests on a commercial aerospace epoxy resin under both isothermal and dynamic heating conditions with calorimetry and impedance spectroscopy have demonstrated the validity of the method and set the accuracy limits involved. This technique can be used as a real‐time online control tool for thermoset composite manufacturing. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 146–154, 2004
Phase transitions in ultraoriented polyethylene fibers under moderate pressures: A synchrotron X‐ray study
Authors: Rein Dmitry M. , Shavit Liron , Khalfin Rafail L. , Cohen Yachin , Terry Ann , Rastogi Sanjay
Published: December 2003

The effect of pressure on phase transformations of ultradrawn ultra‐high‐molecular‐weight polyethylene (UHMWPE) fibers was examined by in situ X‐ray diffraction measurements with synchrotron radiation. The mesomorphic hexagonal phase was metastable even at a relatively low pressure of about 100 bar. The effect of pressure on the melting transitions was larger than in chain‐folded structures. The existence and metastability of the hexagonal phase is the basis of compaction technology of UHMWPE fibers in composite materials. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 53–59, 2004
Structure and electrical properties of undoped oriented poly(phenylene vinylene) films
Authors: Ou Runqing , Gerhardt Rosario A. , Samuels Robert J.
Published: December 2003

The influence of anisotropic structure on the electrical properties of undoped oriented poly(phenylene vinylene) (PPV) films was investigated with impedance spectroscopy and structural characterization. The oriented structure of the stretched PPV films was studied with wave‐guide coupling and infrared dichroism. It was found that the unstretched PPV film had a highly planar structure, and one‐way stretching converted the planar structure into a uniaxial structure. The impedance of undoped PPV thin films was measured along three different directions: through the film thickness direction, parallel to the stretch direction in the film plane, and perpendicular to the stretch direction in the film plane. Two relaxations were observed, one corresponding to the bulk behavior in the high‐frequency range and the other to an interfacial contact polarization in the low‐frequency range. From equivalent circuit modeling, it was found that the bulk conductivity through the film thickness direction decreased with increasing orientation, whereas the high‐frequency dielectric constant through the film direction remained constant. In addition, the conductivities measured in the film plane were at least two orders of magnitude higher than the conductivity in the direction normal to the film surface. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 98–116, 2004
Characterizing Particle Characterization†
Authors: Scott David M.
Published: December 2003

The field of Particle Characterization is important to a broad range of commercial and academic activities, and it includes an extensive array of techniques, instruments, and applications. An attempt is made here to provide a framework for describing and assessing this complex field. This brief overview touches on three topics: the motivation for Characterization, a proposed system for categorizing work within the field, and examples of recent technological advances. The examples include photonic, ultrasonic and electrosonic measurement of particle size, tomographic determination of concentration and multiphase flow, optical trapping and AFM techniques for measuring interparticle forces, and in‐line imaging techniques combined with image analysis to measure shape factors. Some of these techniques have been implemented in on‐line and in‐line applications. These highlights, together with the descriptive framework, provide a broad overview of the current state of the art.
Standardization of Methods for Characterizing the Surface Geometry of Solids
Authors: Da̧browski Andrzej , Robens Erich , Klobes Peter , Meyer Klaus , Podkościelny Przemyslaw
Published: December 2003

Since a comprehensive survey published in 1999 [1] much work was done in standardizing measuring methods to characterize the surface geometry of dispersed and/or porous solids and to certify reference materials. The present paper is an extension of a short communication [2]. It gives a survey on existing standards and reports on new drafts and proposals.
Analysis of Single Particle Attrition during Impact Experiments†
Authors: Pitchumani Ramanan , Gupta Nishant , Meesters Gabriel M. H. , Scarlett Brian
Published: December 2003

Particle breakage can be characterised as attrition, chipping, fracture, abrasion and wear. All these types of breakage mechanisms are the effect of the damage caused to these particles. These mechanisms can be differentiated not just on the basis of magnitude and direction of the force but also by the damage caused to the particles. The damage is measured by change in the size distribution and the change in shape of the particles. In the current research, experiments were performed on the newly developed Repeated Impact Test. The unique feature of this test is that about hundred particles can be subjected simultaneously to a monitored number of impacts, without particle‐particle interactions at regulated velocities. The preliminary experiments were performed with single crystalline particles of different shapes and sizes. After fixed number of impacts, the images of the particles were taken. The volume and shape of the particles were determined by image analysis. It was observed that the rate of attrition was very high when the particles are irregular. The rate decreased as the particles became more spherical.
Coordination Number of Ternary Mixtures of Spheres†
Authors: Zou R. P. , Bian X. , Pinson D. , Yang R. Y. , Yu A. B. , Zulli P.
Published: December 2003

This paper presents an experimental study of the coordination number of ternary mixtures of particles of sizes 24.4 : 11.6 : 6.4 (mm) by the use of the liquid bridge technique. It generates detailed information about the distributed coordination numbers corresponding to different types of contacts between small, medium and large components. The analysis is focused on the mean coordination numbers corresponding to these contacts. The results indicate that these partial mean coordination numbers vary with the volume fractions of the components while the overall mean coordination number is essentially a constant and independent of particle size distribution.
Effects of Polymer Bridging and Electrostatics on the Rheological Behavior of Aqueous Colloidal Dispersions†
Authors: Zaman Abbas A.
Published: December 2003

Effects of a low molecular weight physically adsorbed polyethylene oxide (PEO) and the range of the electrostatic repulsion on the rheological behavior of silica dispersions (as a model system) has been investigated. Particular attention is given to the evolution of the rheological behavior with increasing the polymer concentration in the system and also effectiveness of the polymer as a dispersant under extreme conditions (high ionic strength). Results indicate that at small separation distances and low polymer coverage, the polymer chains are long enough to adsorb on the surface of two particles simultaneously causing bridging flocculation in the system and hence increasing the viscosity and linear viscoelastic functions of the dispersion.
A significant increase was observed in the viscosity of the dispersion at salt concentrations high enough to eliminate electrostatics between the particles. Under these conditions,the viscosity of the system increased significantly when PEO was added to the dispersion showing that at high electrolyte concentrations, a neutral polymer such as PEO is not able to stabilize the system.
Scalable Chi‐Square Distance versus Conventional Statistical Distance for Process Monitoring with Uncorrelated Data Variables
Authors: Ye Nong , Borror Connie M. , Parmar Darshit
Published: December 2003

Multivariate statistical process control charts are often used for process monitoring to detect out‐of‐control anomalies. However, multivariate control charts based on conventional statistical distance measures, such as the one used in the Hotelling's ${T}^{{2}}$ control chart, cannot scale up to large amounts of complex process data, e.g. data with a large number of variables and a high rate of data sampling. In our previous work we developed a multivariate statistical process monitoring procedure based on a more scalable chi‐square distance measure and tested this procedure for detecting out‐of control anomalies—intrusions—in a computer process using computer audit data. The testing results demonstrated the comparable performance of the scalable chi‐square procedure to that of Hotelling's ${T}^{{2}}$ control chart. To establish the chi‐square procedure as a generic, viable multivariate statistical processing monitoring procedure, we conduct a series of further studies to understand the detection power and limitations of the chi‐square procedure for processes with various kinds of data and various types of out‐of‐control anomalies in addition to the scalability and demonstrated performance of the chi‐square procedure for computer intrusion detection. This paper reports on one of these studies that investigates the effectiveness of the scalable chi‐square procedure in detecting out‐of‐control anomalies in processes with uncorrelated data variables, each of which has a normal probability distribution. The results of this study indicate that the chi‐square procedure is at least as effective as Hotelling's ${T}^{{2}}$ control chart for monitoring processes with uncorrelated data variables. Copyright © 2003 John Wiley & Sons, Ltd.
Quantification of priming and CO2 respiration sources following slurry‐C incorporation into two grassland soils with different C content
Authors: Bol R. , Moering J. , Kuzyakov Y. , Amelung W.
Published: December 2003

The fate of incorporated slurry‐C was examined in a laboratory experiment using two UK grassland soils, i.e. a Pelostagnogley (5.1 %C) and a Brown Earth (2.3 %C). C3 and C4 slurries were incorporated into these two wet‐sieved (C3) soils (from 4–10 cm depth). Gas samples were collected 0.2, 1, 2, 3, 4, 6, 9, 20, 30 and 40 days after slurry application and analyzed for CO2 concentration and δ13C content. Slurry incorporation into the soil strongly increased soil CO2 respiration compared with the unamended soil. Total (40 day) cumulative CO2 flux was higher for the Pelostagnogley than the Brown Earth. The 13C natural abundance tracer technique enabled quantification of the sources of respired CO2 and priming effects (days 0–9). Proportionally more slurry‐derived C was respired from the Pelostagnogley (46%) than the Brown Earth (36%). The incorporated slurry‐C was lost twice as fast as the native soil C in both soils. Slurry incorporation induced a priming effect, i.e. additional release of soil‐derived C, most pronounced in the Pelostagnogley (highest C content). The majority of respired soil‐derived C (>70%) was primed C. The study indicated that potential reductions in ammonia volatilisation following slurry injection to grasslands might be negated by enhanced loss of primed soil C (i.e. pollution swapping). Copyright © 2003 John Wiley & Sons, Ltd.
Relationship between soil organic C degradability and the evolution of the δ13C signature in profiles under permanent grassland
Authors: Accoe Frederik , Boeckx Pascal , Cleemput Oswald Van , Hofman Georges
Published: December 2003

The main objective of this research was to investigate to what extent the potential C dynamics of soil organic matter (SOM) are related to the degree of 13C enrichment with increasing depth in soil profiles under permanent grassland. The evolution of the C content and the 13C natural abundance (δ13C value) of SOM were investigated in three soil profiles (0–40 cm depth) under permanent grassland of varying texture (a loamy sand, a loam and a clay loam soil). The δ13C value of the SOM showed a gradual increase with increasing depth and decreasing C content in the profiles, ranging from 1.9‰ (loamy sand soil), 2.9‰ (clay loam soil) and 4‰ (loam soil) in relation to the δ13C value of SOM at the surface. The relationship between the 13C enrichment and total organic C content at different depths in the profiles (down to 40 cm depth in the loam and clay loam soil, down to 25 cm depth in the loamy sand soil) could be well described by the Rayleigh equation. The enrichment factors ε, associated with the Rayleigh approximation of the data, ranged from −1.57‰ (clay loam soil) to −1.64‰ (loamy sand soil) and −1.91‰ (loam soil). The potential C dynamics in four depth intervals from the profiles (0–10, 10–20, 20–30 and 30–40 cm depth) were determined by means of an incubation experiment. The C decomposition rate constants from the four sampling depths in the profiles showed a significant, positive correlation (y = 0.21x + 0.018, R2 = 0.66, p < 0.005) with the corresponding Δδ13C values (change of the δ13C value per depth increment). A better correlation was obtained when only the data from the upper 20 cm in the profiles (y = 0.21x + 0.019, R2 = 0.78, p < 0.05) were considered. These results suggest that the Δδ13C values in the surface layers of profiles under permanent grassland may serve as an indicator of the potential degradability or the stability of the SOM (in terms of C decomposition rate constants). Copyright © 2003 John Wiley & Sons, Ltd.
High‐throughput screening of pKa values of pharmaceuticals by pressure‐assisted capillary electrophoresis and mass spectrometry
Authors: Wan Hong , Holmén Anders G. , Wang Yudong , Lindberg Walter , Englund Marie , Någård Mats B. , Thompson Richard A.
Published: December 2003

A high‐throughput pKa screening method based on pressure‐assisted capillary electrophoresis (CE) and mass spectrometry (MS) is presented. Effects of buffer type and ionic strength on sensitivity and pKa values were investigated. Influence of dimethyl sulfoxide (DMSO) concentration present in the sample on effective mobility measurement was examined. A series of ten volatile buffers, covering a pH range from 2.5 to 10.5 with the same ionic strength, was employed. The application of volatile background electrolytes resulted in significant signal increase as compared with commonly used non‐volatile phosphate buffers. In general, the CE/MS system provided a ten‐fold higher sensitivity than conventional UV detection. The newly developed CE/MS method offers high‐throughput capacity by pooling a number of compounds into a single sample. Simultaneous measurement of more than 50 compounds was readily achieved in less than 150 min. The measured pKa values are consistent with the published data obtained from the CE/UV method and are also in good agreement with data generated by other methods. Other advantages of using CE/MS for pKa screening are illustrated with typical examples, including poorly soluble compounds and non‐UV‐absorbing compounds. Copyright © 2003 John Wiley & Sons, Ltd.
Practical considerations in the gas chromatography/combustion/isotope ratio monitoring mass spectrometry of 13C‐enriched compounds: detection limits and carryover effects
Authors: Mottram Hazel R. , Evershed Richard P.
Published: December 2003

This paper describes a methodological investigation of the use of gas chromatography/combustion/isotope ratio monitoring mass spectrometry (GC/C/IRMS) for the compound‐specific stable isotope analysis of 13C‐enriched compounds. Analysis of two 13C‐enriched fatty acid methyl esters, possessing δ13C values of ∼500‰, at a range of concentrations, demonstrated that detectable responses, i.e. chromatographic peaks, could be observed in the 45/44 output even when the compound was present in such low abundance that no peak was observed in the m/z 44 ion chromatogram. A limit of detection, defined as the point at which the signal‐to‐background ratio was equal to 3, was calculated for two compounds and for both ion chromatograms. The limit of detection in the 45/44 chromatogram was found to be ca. 30 pg injected for methyl 13C‐hexadecanoate and ca. 20 pg injected for methyl 13C‐octadecanoate, whilst, in the m/z 44 ion chromatogram, detection limits were ∼180 and ∼200 pg, respectively. The δ13C value recorded for the analytes was found to be both inaccurate and imprecise below 5 ng of each component injected, although this would not represent a significant drawback in qualitative tracer‐type experiments. In a further study of co‐injected mixtures of labelled (∼500‰) and unlabelled (natural abundance, −20 to −30‰) fatty acid methyl esters a significant within‐run carryover effect was observed, where the isotope values recorded for compounds eluting immediately after enriched components were significantly affected. Whilst this would not affect qualitative results, quantitative data for mixtures containing enriched compounds should be considered with caution. The standards employed in this investigation were enriched to ∼500‰ in 13C; however, these effects would probably be accentuated at higher levels of labelling and with other elements. The limit of detection work demonstrated the potential of GC/C/IRMS as a highly sensitive and selective detector with many possible applications. Copyright © 2003 John Wiley & Sons, Ltd.
Discrimination against 13C during degradation of simple and complex substrates by two white rot fungi
Authors: Fernandez Irene , Cadisch Georg
Published: December 2003

Changes in isotopic 13C signatures of CO2‐C evolved during decomposition of a sugar (glucose), a fatty acid (palmitic acid), a protein (albumin), a structural biopolymer (lignin) and bulk plant tissue (aerial shoots from Lolium perenne) were monitored over a period of 76 days. All materials were sterilized and inoculated with either of two different species of white rot fungi, Phanerochaete chrysosporium or Coriolus versicolor, and incubated in sealed bottles at 28°C. The CO2 concentration in the jars was periodically determined using an infrared gas analyzer and its isotopic (13C) signature was assessed using a trace gas (ANCA TGII) module coupled to an isotope ratio mass spectrometer (IRMS, Europa 20‐20). L. perenne material inoculated with C. versicolor showed the highest C mineralization activity with approximately 70% of total C evolved as CO2 after 76 days of incubation, followed by glucose. Substrates inoculated with C. versicolor generally decomposed faster than when degraded by P. chrysosporium, except for lignin, where no significant differences between the two fungi types were found and CO2‐C released was less than 2% of the initial C. Considerable 13C isotopic fractionation during the degradation of plant tissue and of pure biochemical compounds was revealed as well as progressive shifts in cumulative CO2‐13C isotopic signatures over time. During the first stages of decomposition, the CO2‐C released was usually depleted in 13C as compared with the initial solid substrate, but with ongoing decomposition the CO2‐C evolved became progressively more enriched in 13C. P. chrysosporium usually showed a slightly higher 13C fractionation than C. versicolor during the first decomposition phase. At posterior decomposition stages isotopic discrimination was often stronger by C. versicolor. These findings on isotopic 13C discrimination during microbial degradation both of simple biochemical compounds and of complex vegetal tissue confirmed not only the existence of significant 13C isotopic fractionation during plant residue decomposition, but also the existence of non‐random isotopic distribution within substrates. They also demonstrated the ability of microorganisms to selectively discriminate against 13C even when degrading an isolated simple substrate. Copyright © 2003 John Wiley & Sons, Ltd.
Automated analysis of 13C/12C ratios in CO2 and dissolved inorganic carbon for ecological and environmental applications
Authors: Torn Margaret S. , Davis Simon , Bird Jeffrey A. , Shaw M. Rebecca , Conrad Mark E.
Published: December 2003

Stable carbon isotope ratios (13C/12C) are a valuable tool for studying a wide range of environmental processes, including carbon cycling and subsurface microbial activity. Recent advances in automated analysis provide the opportunity to increase greatly the ease and consistency of isotopic analysis. This study evaluated an automated headspace sampler linked to a commercially available CO2 preconcentration system and continuous flow isotope ratio mass spectrometer. Field sampling and analysis methods are illustrated for δ13C of soil respired CO2, from both tracer and natural abundance experiments, and dissolved inorganic carbon from contaminated groundwater. The automated system demonstrated accuracy, precision, and linearity, with standard errors below 0.1‰ for replicate gas standards run at concentrations varying five‐fold. It measured 40 samples per 10‐hour run, with concentrations ranging from ppb to percentage levels. In the field, gas samples were injected into nitrogen‐filled autosampler vials, thereby allowing use of small sample volumes, control of analyte concentration, and direct analysis by the automated system with no further preparation. A significant linear relationship between standard concentrations and peak area allows for accurate estimates of sample CO2 concentration from the mass spectrometric data. The ability to analyze multiple small‐volume samples with minimal off‐line preparation should enhance the application of isotopes to well‐replicated field experiments for process‐level studies and spatial and temporal scaling. Copyright © 2003 John Wiley & Sons, Ltd.
Use of liquid chromatography/time‐of‐flight mass spectrometry and multivariate statistical analysis shows promise for the detection of drug metabolites in biological fluids
Authors: Plumb Robert S. , Stumpf Chris L. , Granger Jennifer H. , Castro‐Perez Jose , Haselden John N. , Dear Gordon J.
Published: December 2003

The process of metabolite identification is essential to the drug discovery and development process; this is usually achieved by liquid chromatography/tandem mass spectrometry (LC/MS/MS) or a combination of liquid chromatography/mass spectrometry (LC/MS) and nuclear magnetic resonance (NMR) spectroscopy. Metabolite identification is, however, a time‐consuming process requiring an experienced skilled scientist. Multivariate statistical analysis has been used in the field of metabonomics to elucidate differences in endogenous biological profiling due to a toxic effect or a disease state. In this paper we show how a combination of liquid chromatography/time‐of‐flight mass spectrometry (LC/TOFMS) and multivariate statistical analysis can be used to detect drug metabolites in a biological fluid with no prior knowledge of the compound administered. Copyright © 2003 John Wiley & Sons, Ltd.