bluuebunny/crossref_metadata_2025_split huggingface dataset:
Metal‐polymer nanocomposites for integrated microfluidic separations and surface enhanced Raman spectroscopic detection
Authors: Connatser R. Maggie , Riddle Lance A. , Sepaniak Michael J. 
Published: November 2004

AbstractThe widespread development of microfluidics (μfluidics) has allowed the extension of efficient separations, fluid handling, and hyphenation with many detection modes to a small, portable, highly controllable physico‐chemical platform. Surface enhanced Raman spectroscopy (SERS) offers the powerful advantage of obtaining vibrational spectroscopic information about analytes in an aqueous matrix with negligible background. The mating of electrophoretic separations with vibrational spectroscopy on a μfluidic device will allow the chromatographic efficiency of capillary electrophoresis (CE) with the unequivocal analyte “fingerprinting” capability of detailed structural information. By utilizing SERS as a means of detection, this work promises to yield redress for the hindrances of electrophoretic separations, including uncertainty in analyte band identification due to changing migration times as well as compromised detection sensitivity for non‐fluorescent analytes. Our work represents the first steps toward developing CE‐SERS on a μfluidic platform with a region of novel metal‐pliable polymer nanocomposite SERS substrate fabricated directly into the device. The device fabrication material has been extensively employed by the μfluidics community for over five years. SERS detection can be achieved in real time or after the separations, with on‐column laser‐induced fluorescence employed as a secondary detection mode used for confirmation of efficiencies and band locations.
Regulation of lung cancer cell growth and invasiveness by β‐TRCP
Authors: He Nonggao , Li Chengxin , Zhang Xiaoli , Sheng Tao , Chi Sumin , Chen Kai , Wang Qian , Vertrees Roger , Logrono Roberto , Xie Jingwu 
Published: November 2004

AbstractBeta‐transducin‐repeat‐containing protein (β‐TRCP) serves as a substrate‐recognition subunit of Skp1/Cullin/F‐box (SCF)β‐TRCPE3 ligases, involved in regulation of several important signaling molecules. SCFβ‐TRCPE3 ligases play a critical role in cell mitosis as well as in various signaling pathways. Here, we provide evidence to support that β‐TRCP negatively regulates cell growth and motility of lung cancer cells. With specific antibodies, we detect loss of β‐TRCP1 protein in several lung cancer cell lines. One cell line contains an inactivated mutation of theβ‐TRCP1gene. Loss of β‐TRCP1 protein is also found in subsets of lung cancer specimens. We observe that retrovirus‐mediated stable expression of β‐TRCP1 in β‐TRCP1 negative cells inhibits cell growth in soft‐agar and tumor formation in nude mice. Furthermore, expression of β‐TRCP1 alters cell motility, as indicated by morphological changes and a reduced level of active matrix metalloproteinase (MMP)11. Conversely, inactivation of β‐TRCP1 by specific siRNA accelerates cell invasion. Of the 10 known substrates of SCFβ‐TRCPE3 ligases, the protein level of cell division cycle 25 (CDC25)A is clearly affected in these lung cancer cells. Cells treated with CDC25A inhibitors become less invasive. Thus, loss of β‐TRCP1 may promote both growth and cell motility of lung cancer cells, possibly through regulation of CDC25A and the MMP11 level. © 2004 Wiley‐Liss, Inc.
Mutations and elevated transcriptional activity of conductin (AXIN2) in hepatoblastomas
Authors: Koch Arend , Weber Nina , Waha Andreas , Hartmann Wolfgang , Denkhaus Dorota , Behrens Jürgen , Birchmeier Walter , Schweinitz Dietrich von , Pietsch Torsten 
Published: November 2004

AbstractHepatoblastoma (HB) is the most frequent malignant liver tumour of childhood. Most HBs develop sporadically but their incidence is highly elevated in patients with familial adenomatous polyposis coli (FAP). These patients carry germline mutations in the adenomatous polyposis coli (APC) tumour suppressor gene. APC forms a multi‐protein complex involved in the WNT signalling pathway that controls the stability of β‐catenin, the central effector in this cascade. Whereas APC mutations are rare in sporadic HBs, a high frequency of β‐catenin mutations leading to overactivation of WNT signalling was previously found in these tumours. This pathway is negatively controlled by conductin (axin2), representing a further partner in this signalling complex. To investigate whether alterations in conductin may also be involved in the pathogenesis of sporadic HBs, 37 HBs and five HB cell lines were screened for mutations using single‐strand conformation polymorphism (SSCP) analysis, reverse transcription‐polymerase chain reaction (RT‐PCR), and direct sequencing. In two cases, larger deletions (52 and 1624 bp) leading to frameshifts were found. In addition, one HB carried a somatic point mutation. Expression analysis by competitive RT‐PCR in HBs revealed up‐regulation of conductin mRNA compared with adjacent liver samples. This mRNA overexpression resulted in increased conductin protein levels demonstrated by western blot analysis. Tumours with activating β‐catenin mutations revealed higher levels of conductin mRNA transcripts. This finding indicates that conductin is a direct target gene of WNT signalling in HBs, as has been demonstrated in other tissues. In summary, conductin mutations may represent an alternative mechanism leading to activation of WNT signalling in HBs. The overexpression of conductin mRNA in HBs reflects activation of the WNT pathway because conductin represents a target gene of WNT signalling in liver tissue. Copyright © 2004 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Design of a polymer‐based phase modulator: validation of the various processes
Authors: Cornic Charles , Lucas Bruno , Moliton André 
Published: November 2004

AbstractThis work is devoted to the development of technology processes with the aim of realizing a phase modulator based on organic materials. At first, a semiconductor technology is adapted to polymers to elaborate waveguides, and to realize the stacking of layers of passive and active polymers compatible with processes on a silicon substrate. By using the reactive ion‐beam etching process, we obtained waveguides with good vertical walls and propagation losses of around 0.5 dB cm−1. For realization of the ‘whole‐polymer’ phase modulator, as a guiding layer we used the fluorinated polyimide, 6FDA/MPDA (Figure1), mixed with a colorant, Disperse Red One (DR1); this layer is sandwiched between two organic layers with lower indices. The lower cladding layer was realized with the 6FDA/MPDA polyimide, and the upper cladding layer with poly(methyl methacrylate) (PMMA) deposited on a thin anhydride‐(6 FDA) and diamine‐(ODA) based polyimide layer obtained by vapor deposition polymerization (VDP): this layer leads to a good adherence between the active layers, while the PMMA layer can also be covered with 6FDA/ODA which then acts as a protective layer. With an infrared camera, we have shown propagation of the guided wave in a configuration‐phase modulator, and thus validated a whole technological process. Copyright © 2004 Society of Chemical Industry1. Molecular structure of the 6FDA/MPDA monomer.magnified image1. Molecular structure of the 6FDA/MPDA monomer.
Determining Contact Angles of Powders by Liquid Penetration
Authors: Teipel Ulrich , Mikonsaari Irma 
Published: November 2004

AbstractThe wettability of a powder is important, especially in chemical and pharmaceutical technologies when considering the manufacturing process and the properties of the final product. However, contact angle methods for powders are problematic. The common measurement techniques are the sessile drop method and the liquid penetration method. In this work the determination of contact angles of powders by liquid penetration is considered. In particular, we investigated the influence of the sample preparation and sampling device on the wetting process. A bulk with constant properties during the measurement must be guaranteed. We postulate a packing procedure to obtain reproducible measurements by ensuring constant powder properties.
Bulk Mechanical Behavior of Rootzone Sand Mixtures as Influenced by Particle Shape, Moisture and Peat
Authors: Mittal Bhavishya , Yi HoJae , Puri Virendra M. , McNitt Andrew S. , Mancino Charles F. 
Published: November 2004

AbstractMechanical properties such as bulk modulus, shear modulus, and failure stress of rootzone sand mixtures are some of the key parameters in understanding the load‐response of sands used in professional golf courses. According to the United States Golf Association (USGA) specifications, appropriate particle size distributions and their shape are important for preparing putting greens and bunker sands. Despite being an important parameter, the influence of sand particle shape on the bulk mechanical properties of the rootzone mixtures has not been studied systematically using a fundamental tester. Toward this end, bulk mechanical properties were measured using a low‐pressure cubical (true) triaxial tester. In this study, four of the commonly used basic shapes, i.e., round, subround, subangular, and angular sand particles comprising rootzone mixtures with sphagnum peat (organics) were tested at two different moisture levels, air‐dried and 30 cm moisture tension conditions. For all rootzone sand mixtures, an increase in bulk modulus was observed with increasing isotropic pressure. The failure stress values increased with the increase in mean pressure for air dried samples. In general, moisture increased compressibility of sands and decreased failure strength and shear modulus values. Peat had a dominant influence on the mechanical response of all four sand shapes. When peat and moisture were added, the rootzone mixture became most compressible and easier to fail, with noticeable changes in bulk mechanical properties.
The Influence of Air Counter‐Flow Through Powder Materials as a Means of Reducing Cohesive Flow Problems
Authors: Johanson Kerry , Barletta Diego 
Published: November 2004

AbstractThe cohesive behavior of aerated solids controls fluidization behavior of bulk materials. Very cohesive materials cannot be easily fluidized. However, aeration is often used in contact bed situations to help maintain some cohesive materials in flowable conditions. The cohesive properties of aerated materials are not well understood. This paper presents a new test method to measure the effect of aeration on cohesive flow properties. These measurements could be used along with new design equations to predict arching and stable rathole formation of cohesive materials in aerated process equipment. Experimental results on fine silica powder and fluid catalytic cracking (FCC) catalyst show the evolution of the yield locus shape and the effective yield locus shape as a function of the degree of aeration. It was found that both the cohesion intercept and the yield locus slope are functions of the degree of aeration.
Stress Inhomogeneity in Powder Specimens Tested in the Jenike Shear Cell: Myth or Fact?
Authors: Bilgili Ecevit , Yepes Juan , Stephenson Luke , Johanson Kerry , Scarlett Brian 
Published: November 2004

AbstractIn the mechanical characterization of powders using the direct shear testers such as the Jenike shear cell, the existence of a uniform or well‐defined stress field in a powder specimen is assumed. This assumption has not been subjected to any serious scrutiny in the literature. In this study, the normal stress variation in a silica powder was locally determined by locating a pressure‐sensitive TekScan pad at the bottom section of a Jenike shear cell. A computer simulation of the consolidation and pre‐shearing stages of the Jenike test procedure was performed using the Discrete Element Method (DEM). The paper presents both experimental and computational evidence for the existence of a complex stress field in the powder specimen, thus clearly invalidating the long‐standing stress homogeneity assumption in the direct shear testing of powders. The implications of the stress inhomogeneity in terms of the accuracy of the material properties extracted from the Jenike test are also presented.
Identification of hypoxia‐inducible factor‐1α (HIF‐1α) polymorphism as a mutation in prostate cancer that prevents normoxia‐induced degradation
Authors: Fu Xinyu S. , Choi Eunis , Bubley Glenn J. , Balk Steven P. 
Published: November 2004

AbstractBACKGROUNDHypoxia‐inducible factor‐1α (HIF‐1α) regulates cellular responses to hypoxia and is rapidly degraded under normoxia through von Hippel‐Lindau (VHL) mediated ubiquitination. Although HIF‐1α stabilization appears to be the molecular basis for VHL‐associated cancers, stabilizing mutations in HIF‐1α have not been reported.METHODSA series of 15 metastatic androgen independent prostate cancers were examined for mutations in the oxygen‐dependent domain (ODD) of HIF‐1α by PCR amplification and DNA sequencing.RESULTSA somatic proline to serine mutation in codon 582 (P582S) was identified in one sample. Transfection studies with a HIF‐1α regulated reporter gene showed increased transcriptional activity that correlated with higher mutant HIF‐1α protein expression. Increased expression of the P582S mutant induced by iron chelation, which blocks proline hydroxylation of wild‐type HIF‐1α, was markedly attenuated. The mutant also showed increased stability under normoxic versus hypoxic conditions.CONCLUSIONThe P582S HIF‐1α is a stable variant and HIF‐1α mutation is a mechanism for enhancing HIF‐1α activity in human cancer. The recent identification of the identical P582S HIF‐1α as a polymorphism suggests that this variant may increase tumor susceptibility or cause more aggressive biological behavior. © 2004 Wiley‐Liss, Inc.
Characterization and PCR‐based detection of benzimidazole‐resistant isolates of Monilinia laxa in California
Authors: Ma Zhonghua , Yoshimura Michael A , Holtz Brent A , Michailides Themis J 
Published: November 2004

AbstractMonilinia laxa is a pathogen of brown rot of stone fruit and almond in California, causing blossom blights and fruit rots. In this study, low‐level resistance to the benzimidazole fungicides benomyl and thiophanate‐methyl was detected in field isolates of M laxa collected from stone fruits and almonds in California. Low‐resistant (LR) isolates grew in potato dextrose agar (PDA) plates amended with benomyl and thiophanate‐methyl at 1 and 5 µg ml−1, respectively, but not in plates amended with benomyl at 5 µg ml−1 or thiophanate‐methyl at 50 µg ml−1. The benzimidazole LR isolates were characterized by temperature sensitivity and the DNA sequence of the β‐tubulin gene. The LR isolates showed high‐temperature sensitivity, being sensitive to 1 µg ml−1 of benomyl at 28 °C but resistant at 8–24 °C. Analysis of the DNA sequence of the β‐tubulin gene showed that the LR isolates had a point mutation at the amino‐acid position 240, causing substitution of leucine by phenylalanine. Based on the point mutation, a pair of allele‐specific PCR primers was developed for rapid detection of LR isolates of M laxa. In addition, a pair of PCR primers specific to M laxa was developed on the basis of the differences in the DNA sequence of the intron 6 of β‐tubulin gene from M laxa, M fructicola and other fungal species. The primer pair amplified the expected 376‐bp DNA fragment from all M laxa isolates tested, but not from 14 other fungal species isolated from stone fruit and almond crops. The restriction endonuclease BsmA I recognized the sequence GTCTCC in the PCR products from sensitive (S) isolates only, but not the GTTTCC sequence in the PCR products from LR isolates. The endonuclease digested the 376‐bp PCR products from S isolates to produce two bands (111 and 265 bp) on agarose gels. Thus, both allele‐specific PCR and the PCR‐restriction fragment length polymorphism (PCR‐RFLP) methods could be useful for rapidly detecting benzimidazole‐resistant isolates of M laxa from stone fruit and almond crops in California. Copyright © 2004 Society of Chemical Industry
Highly accurate relativistic universal Gaussian basis set for Dirac–Fock–Breit calculations
Authors: De Macedo L. G. M. , Barbosa R. C. , da Silva A. B. F. 
Published: November 2004

AbstractA universal Gaussian basis set is presented to perform highly accurate Dirac–Fock–Breit calculations. The Gaussian‐type functions of our universal basis set satisfy the relativistic boundary conditions associated with the finite nucleus model, for a finite velocity of light, and conform to the so‐called kinetic balance at the nonrelativistic limit. The high accuracy obtained in our Dirac–Fock–Breit calculations is attributed to the fact that with our universal Gaussian basis set we are able to better represent the relativistic kinematics of an electron inside the nucleus. Results for the Dirac–Fock–Breit energies for a number of neutral atoms up to nobelium and some of their negative ions are presented and compared with the results of Parpia et al., obtained by employing a geometrical Gaussian basis set and a more accurate value for the velocity of light. The Dirac–Fock–Breit energy results presented in this work, using our universal Gaussian basis set, are among the best obtained with Gaussian‐type functions in the literature. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Maintaining the quality focus in the business‐to‐business auction model
Authors: Yasin Mahmoud M. , Czuchry Andrew J. , Bayes Paul E. 
Published: November 2004

AbstractThe growth of business‐to‐business auctions presents the quality‐focused business organization with many opportunities and some serious challenges. In this context, the absence of a well‐designed organizational e‐business auction‐based strategy has the potential to promote business practices which may erode organizational quality gains. This article presents a conceptual open system approach designed to improve the quality focus of business‐to‐business auctions practices. The open system approach advocated in this article is quality focused and supply‐chain sensitive. Copyright © 2004 John Wiley & Sons, Ltd.
The Three Gorges Dam Project from a systems viewpoint
Authors: Alberts Henry C. , Alberts Renée M. , Bloom Mitchel F. , LaFlamme A. Diane , Teerikangas Satu 
Published: November 2004

AbstractThe Three Gorges Dam on the Yangtze River is currently the largest construction project in the world. Because of its complexity, integration of social, environmental and technological systems, and tight coupling required by the schedule, the project should be managed using a systems approach. To find out if this was the case, the authors formed a research team, sponsored by the International Society of Systems Sciences, to tour the dam sight, interview managers and engineers, travel up the Yangtze to Chongqing, analyze problems posed by the critics of the dam and, finally, report back to the ISSS annual meeting in Shanghai following the trip. This paper reports on the team's observations, the results of the interviews and a systems model that analyzes the problems facing the dam builders. Finally, the paper concludes that the engineers and managers are aware of the interrelated problems and have planned for their solution. Copyright © 2004 John Wiley & Sons, Ltd.
Effects of in vitro exposure to low levels of organotin and carbamate pesticides on human natural killer cell cytotoxic function
Authors: Wilson Sharnise , Dzon Leticia , Reed Adrian , Pruitt Marilyn , Whalen Margaret M. 
Published: November 2004

AbstractHuman natural killer (NK) lymphocytes play a central role in immune system defense against viral infection and against the formation of primary tumors. Organotin (OT) pesticides have been used in industrial and agricultural applications, and OT contamination has been reported in water, sediment, and fish. Carbamate pesticides are currently used in agricultural chemicals. Two specific carbamates used in agriculture are ziram and maneb; ziram also is used as an additive in rubber products including latex gloves. In previous studies we demonstrated that at concentrations in the 150–200 nM range, the OTs tributyltin (TBT) and triphenyltin (TPT) were capable of disrupting the function of human NK cells after incubations to as short as 24 h. Previously, we also examined the effects of ziram and maneb at higher concentrations on the cytotoxic function of human NK cells. The current study examined the effects of exposure of up to 6 days to lower concentrations of each of these compounds on the cytotoxic function of NK cells. The OTs were studied at concentrations ranging from 200 to 10 nM; ziram was studied at concentrations of 2.5 μM–125 nM and maneb at concentrations of 10–1 μM. These conditions were studied both in highly purified NK cells and in a mixture of lymphocytes containing both T and NK cells. As little as 25 nM TBT decreased the function of purified NK cells after 24 and 48 h, whereas 10 nM TBT was effective after 6 days. The lowest level of TPT that was effective at 24 h was 50 nM whereas the results after 48 h and 6 days were similar to those seen with TBT. The presence of T lymphocytes diminished the effects of both TBT and TPT on NK cytotoxic function. A concentration of ziram as low as 125 nM produced significant loss of cytotoxic function in highly purified NK cells (65% decrease in function after 6 days). The toxicity of each of the compounds studied increased very significantly with length of exposure. © 2004 Wiley Periodicals, Inc. Environ Toxicol 19: 554–563, 2004
Inflammatory activity in river‐water samples
Authors: Wichmann G. , Daegelmann C. , Herbarth O. , Strauch G. , Schirmer K. , Wöstemeyer J. , Lehmann I. 
Published: November 2004

AbstractContamination of the urban aquatic environment with chemical and biological substances could have a long‐term impact on human health because these substances threaten the integrity of the urban ecosystem and the availability of high‐quality water for recreation and consumption. In light of this, the aim of the present study was to assess the potential immunological effects of water sampled at various sites along the River Saale near the city of Halle (in the state of Sachsen‐Anhalt, Germany). For the control, Ficoll‐separated peripheral blood mononuclear cells (PBMC) of healthy donors were cultured for 24 h in either filter‐sterilized river water or drinking‐water samples. Cell vitality was assessed using the MTT bioassay. Cytokines in culture supernatants were measured by ELISA. Endotoxin concentrations in the water samples were assessed by the limulus amoebocyte lysate (LAL) test. River water and drinking water showed comparably weak cytotoxic effects on PBMC. Drinking water did not exert any effect on cytokine secretion. In contrast, all river‐water samples triggered secretion of proinflammatory cytokines, as shown for TNF‐α, IL‐1β, and IL‐6. Free endotoxin was detected in all river‐water samples. However, the highest inflammatory activity regarding induction of all three cytokines, as well as the highest endotoxin content as determined by LAL, was found in a water sample taken immediately downstream of a wastewater treatment plant. Inhibition studies using the monoclonal anti‐CD14 antibody biG14, which is known to suppress binding of lipopolysaccharide (LPS) to CD14 via binding CD14 itself, revealed that free endotoxin was indeed the major inducer of proinflammatory cytokines in the river‐water samples. Taken together, the results suggest that the microorganism‐derived endotoxin is a widely distributed contaminant in the urban aquatic environment that should be considered in routine monitoring and in assessing ecosystem and human health. © 2004 Wiley Periodicals, Inc. Environ Toxicol 19: 594–602, 2004.