bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis of oligo‐ortho‐azomethinephenol and its oligomer–metal complexes: Characterization and application as anti‐microbial agents
Authors: Kaya Ismet , Vilayetoğlu Adalet R. , Topak Hasan
Published: October 2002

The oxidative polycondensation reaction conditions and optimum parameters of o‐phenylazomethinephenol (PAP) with oxygen (air) and NaOCl were determined in an aqueous alkaline solution at 60–98°C. The properties of oligo‐o‐phenylazomethinephenol (OPAP) were studied by chemical and spectra analyses. PAP was converted to dimers and trimers (25–60%) by oxidation in an aqueous alkaline medium. The number average molecular weight (Mn), mass average molecular weight (Mw), and polydispersity index (PDI) values were 1180 g mol−1, 1930 g mol−1, and 1.64, respectively. According to these values, 20–33% of PAP turned into OPAP. During the polycondensation reaction, a part of the azomethine (CHN) groups oxidized to carboxylic (COOH) group. Thus, a water‐soluble fraction of OPAP was incorporated in the carboxylic (COOH); (2–20%) group. Also, the structure and properties of oligomer–metal complexes of OPAP with Cu(II), Ni(II), Zn(II), and Co(II) were studied. Antimicrobial activites of the oligomer and its oligomer–metal complexes were tested against B. cereus, L. monocytogenes, B. megaterium, B. subtilis, E. coli, Str. thermophilus, M. smegmatis, B. brevis, E. aeroginesa, P. vulgaris, M. luteus, S. aureus, and B. jeoreseens. Also, according to differential thermal analysis and thermogravimetric analysis, OPAP and its oligomer–metal complexes were stable throughout to temperature and thermo‐oxidative decomposition. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2004–2013, 2002
High styrene–rubber ionomers, an alternative to thermoplastic elastomers
Authors: Samuel Jacob , Xavier Thommachan , Kurian Thomas
Published: October 2002

High styrene rubber ionomers were prepared by sulfonating styrene–butadiene rubber of high styrene content (high styrene rubber) in 1,2‐dichloroethane using acetyl sulfate reagent, followed by neutralization of the precursor acids using methanolic zinc acetate. The ionomers were characterized using X‐ray fluorescence spectroscopy, Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance spectroscopy (NMR), dynamic mechanical analysis (DMA), and also by the evaluation of mechanical properties. The FTIR studies of the ionomer reveal that the sulfonate groups are attached to the benzene ring. The NMR spectra give credence to this observation. Results of DMA show an ionic transition (Ti) in addition to glass–rubber transition (Tg). Incorporation of ionic groups results in improved mechanical properties as well as retention of properties after three cycles of processing. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2294–2300, 2002
Synthesis and characterization of alternating copolymer from carbon dioxide and propylene oxide
Authors: Wang S. J. , Du L. C. , Zhao X. S. , Meng Y. Z. , Tjong S. C.
Published: October 2002

High yield and pure zinc glutarate catalysts used for copolymerization of carbon dioxide and propylene oxide have been synthesized in different solvents by ultrasonic methodology. For the purposes of comparison, low‐yield zinc glutarates were also synthesized via mechanical stirring method with other synthetic conditions remaining unchanged. Fourier Transform Infrared Spectroscopy and wide‐angle X‐ray diffraction techniques confirmed the presence of high‐quality zinc glutarate catalysts. Accordingly, poly(propylene carbonate) (PPC) can be synthesized from carbon dioxide and propylene oxide using the zinc glutarate catalysts. It was confirmed that the as‐prepared PPC had an alternating copolymer structure together with high molecular weight. The thermal and mechanical properties of the obtained PPC copolymer were determined by means of differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and tensile test. DSC and TGA results showed that the PPC copolymer exhibited high glass transition temperature (39.39°C) and decomposition temperature (278°C) when compared to their corresponding values reported in the literature. Tensile test showed that the PPC film exhibited superior mechanical strength. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2327–2334, 2002
Surface modification of PET films by pulsed argon plasma
Authors: Inagaki N. , Tasaka S. , Narushima K. , Kobayashi H.
Published: October 2002

The rf power was modulated (discharge on‐time of 10 μs and discharge off‐time of 50–500 μs), for pulsed argon (Ar) and oxygen (O2) plasmas used to irradiate PET film surfaces to modify the film surfaces. From data regarding the contact angle for the modified PET film surfaces and chemical analyses with XPS, effects of the rf power modulation on the surface modification are discussed. The pulsed Ar and O2 plasmas are effective in modification of the PET film surface. There is no difference in the contact angle between the pulsed plasma and the continuous plasma. Furthermore, the pulsed Ar plasma is advantageous in formation of hydroxyl groups on the PET film surfaces. The rf power modulation has a possibility to modify into peculiar surfaces. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2845–2852, 2002
A comprehensive investigation of the origins of surface roughness and haze in polyethylene blown films
Authors: Sukhadia Ashish M. , Rohlfing David C. , Johnson Matthew B. , Wilkes Garth L.
Published: October 2002

In an earlier publication we showed that the optical haze properties of blown and cast polyethylene (PE) films were adversely affected (i.e., haze increased) as a result of enhanced surface roughness caused by the formation of distinct optically anisotropic “spherulitic‐like” superstructures. In this report we have found that for a very wide variety of PE blown films, the total haze percent exhibited a complex parabolic relationship with the logarithm of the recoverable shear strain parameter, γ∞. At low values of γ∞, superstructures were developed (as discussed in our previous report) that increased surface roughness and hence total haze. As γ∞ increased, such superstructures were either significantly diminished in size or altogether absent, giving rise instead to an oriented, row‐nucleated, stacked lamella texture that decreased surface roughness and hence total haze. However, at even higher γ∞ values, representing highly melt elastic behavior, fine‐scale surface roughness due to high melt elastic instabilities was induced, thereby increasing surface roughness and consequently total haze as well. It was demonstrated in this work that two PE resins could exhibit the same level of total haze as a consequence of two completely different mechanisms or origins. Furthermore, we believe that this is the first time that both very low and very high melt elasticity have been shown as primary causative factors in yielding high haze in PE blown films, albeit for fundamentally very different reasons. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2396–2411, 2002
Effects of chemical structure changes on curing reactions and thermal properties of cyanate ester‐cured rigid‐rod epoxy resins
Authors: Su W‐F. A. , Chuang Chih‐Min
Published: October 2002

How chemical structure changes affect the curing reactions and thermal properties of 2,2′‐bis(4‐cyanatophenyl) propane (cyanate ester) cured rigid‐rod epoxy resins has been studied for biphenol and tetramethyl biphenol epoxies. The formation of an oxazolidinone ring is the dominant curing reaction for biphenol epoxy, whereas the formation of a cyanurate ring is the dominant curing reaction for tetramethyl biphenol epoxy, due to the bulky methyl substitutions on the biphenol chain. The crosslinkable cyanurate structure has a higher thermal stability than that of the linear oxazolidinone structure, giving the cyanate ester cured tetramethyl biphenol epoxy resin (molar equivalent) a higher glass transition temperature (260 vs. 218°C) and thermal decomposition temperature (366 vs. 312°C) than that of cyanate ester cured biphenol epoxy resin. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2419–2422, 2002
Gas diffusion and dielectric studies of polystyrene‐fullerene compositions
Authors: Polotskaya G. A. , Gladchenko S. V. , Zgonnik V. N.
Published: October 2002

Polystyrene‐fullerene compositions containing up to 0.45 mol % (3 wt %) fullerene C60 were investigated. It was established that the addition of fullerene to polystyrene (PS) leads to an increase of molecular packing density and so influences the transport of small molecules through the polymer films. Gas diffusion through films of PS‐fullerene compositions is slower than through PS films, and gas separating properties of compositions are higher. Dielectric studies showed that the fullerene is distributed as clusters in the polymer matrix of solid composition prepared from a toluene solution of PS and fullerene. Heating without air to the temperature higher than PS glass transition leads to increasing relaxation time of α‐transition in PS of compositions containing >0.15 mol % (1 wt %) fullerene. This effect is caused by rather strong interaction of PS chains via fullerene molecules entered into the PS‐fullerene complex. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2946–2951, 2002
Thermogravimetric analysis of methyl methacrylate‐graft‐natural rubber
Authors: Peng Zheng , Li Si‐Dong , Huang Mao‐Fang , Xu Kui , Wang Chen , Li Pu‐Wang , Chen Xiao‐Guang
Published: October 2002

The thermal degradations of methyl methacrylate‐graft‐natural rubber (MG) at different heating rates (B) in nitrogen were studied by thermogravimetric analysis. The results indicate that the thermal degradation of MG in nitrogen is a one‐step reaction. The degradation temperatures increase along with the increment of heating rates. The temperature of initial degradation (T0) is 0.448B + 362.4°C, the temperature at maximum degradation rate, that is, the peak temperature on a differential thermogravimetric curve (Tp) is 0.545B + 380.7°C, and the temperature of final degradation (Tf) is 0.476B + 409.4°C. The degradation rate at Tp is not affected by B, and its average value is 48.9%; the degradation rate at Tf is not affected by B either, and its average value is 99.3%. The reaction order (n) is 2.1 and is not affected by B. The reaction activation energy (E) and the frequency factor (A) increase along with B, and the apparent reaction activation energy (E0) is 254.6 kJ/mol. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2952–2955, 2002
Suppression of the melanogenic potential of migrating neural crest‐derived cells by the branchial arches
Authors: Jacobs‐Cohen Rae J. , Wade Paul R. , Gershon Michael D.
Published: October 2002

The development of melanocytes from neural crest‐derived precursors that migrate along the dorsolateral pathway has been attributed to the selection of this route by cells that are fate‐restricted to the melanocyte lineage. Alternatively, melanocytes could arise from nonspecified cells that develop in response to signals encountered while these cells migrate, or at their final destinations. In most animals, the bowel, which is colonized by crest‐derived cells that migrate through the caudal branchial arches, contains no melanocytes; however, the enteric microenvironment does not prevent melanocytes from developing from crest‐derived precursors placed experimentally into the bowel wall. To test the hypothesis that the branchial arches remove the melanogenic potential from the crest‐derived population that colonizes the gut, the Silky fowl (in which the viscera are pigmented) was studied. Sources of crest included Silky fowl and quail vagal and truncal neural folds/tubes, which were cultured or explanted to chorioallantoic membranes alone or together with branchial arches or limb buds from Silky fowl, White Leghorn, or quail embryos. Crest and mesenchyme‐derived cells were distinguished by using the quail nuclear marker. Melanocytes developed from Silky fowl and quail crest‐derived cells. Melanocyte development from both sources was inhibited by quail and White Leghorn branchial arches (and limb buds), but melanocyte development was unaffected by branchial arch (and limb buds) from Silky fowl. These observations suggest that a factor(s) that is normally expressed in the branchial arches, and is lacking in animals with the Silky mutation, prevents cells with a melanogenic potential from colonizing the bowel. Anat Rec 268:16–26, 2002. © 2002 Wiley‐Liss, Inc.
Heterogeneity of chondroitin sulfate glycosaminoglycan localization during early development of the striped bass (Morone saxatilis)
Authors: Capehart Anthony A. , Scemama Jean‐Luc , Singhas Charles A. , Cox Sarah
Published: October 2002

Recent studies have suggested important functions for proteoglycan‐associated chondroitin sulfate glycosaminoglycans (GAGs) during embryonic and larval development in numerous organisms, including the teleost. Little is known, however, about the specific distribution of different chondroitin sulfate GAGs during early development. The present study utilized immunohistochemistry to localize chondroitin sulfate GAG antigens during development of the striped bass (Morone saxatilis). Immunoreagents utilized were monoclonal antibodies (MAbs) TC2, d1C4, and CS‐56, which recognize, respectively, native epitopes on glycosaminoglycan chains enriched in chondroitin‐4‐, chondroitin‐6‐, and both chondroitin‐4‐ and ‐6‐sulfate. Little or no immunoreactivity was observed in gastrulating embryos at 18 hr postfertilization with any MAb tested. By 24 hr (8 somites), the CS‐56 epitope was localized around the notochord. At hatching (48 hr) and early larval (72 hr) stages, d1C4 and CS‐56 antigens codistributed in some sites (e.g., the notochord and myosepta), but a striking heterogeneity of chondroitin sulfate GAG localization was observed in other developing tissues, including the eye and specific subsets of basement membrane. At these latter time points, TC2 reacted primarily with the extracellular matrix of the developing heart, particularly the ventricular and conotruncal segments. Heterogeneous patterning of these chondroitin sulfate GAG epitopes suggests dynamic regulation of proteoglycan function during critical morphogenetic events in early development of the striped bass. Anat Rec 268:47–58, 2002. © 2002 Wiley‐Liss, Inc.
Satellite remote sensing and archaeology: a comparative study of satellite imagery of the environs of Figsbury Ring, Wiltshire
Authors: Fowler Martin J. F.
Published: October 2002

The abilities of three satellite remote sensed image products (low spatial resolution LANDSAT Thematic Mapper (TM); medium resolution SPOT Panchromatic; high resolution KVR‐1000) to detect archaeological features in the environs of the Iron Age hillfort at Figsbury Ring, Wiltshire, have been evaluated. Given prior knowledge of their locations, relatively large features together and those possessing a strong linear nature could be detected on the LANDSAT TM multispectral and SPOT Panchromatic image products. Near‐infrared TM imagery showed promise for the detection of smaller features as a result of differences in vegetation cover, but was constrained by its low spatial resolution. High resolution Russian KVR‐1000 imagery was found to be capable of detecting both upstanding and ploughed‐out archaeological features without the need for prior knowledge of ground truth.

It is concluded that satellite imagery, although not a substitute for conventional aerial photography, represents a complementary source of information when prospecting for archaeological features. In a regional context, low resolution multispectral imagery can be used for the prospection for areas of high archaeological potential through the use of image processing and modelling techniques and, together with medium resolution imagery can be used to prepare base maps of regions for which up to date mapping is not available. High‐resolution imagery, together with conventional aerial photographs, can be used subsequently to detect and map archaeological features. Copyright © 2002 John Wiley & Sons, Ltd.
T cell autoimmunity to histones and nucleosomes is a latent property of the normal immune system
Authors: Andreassen Kristin , Bendiksen Signy , Kjeldsen Elisabeth , Van Ghelue Marijke , Moens Ugo , Arnesen Egil , Rekvig Ole Petter
Published: October 2002

Objective

Investigators in this study undertook to determine whether in vitro antigen‐responsive immune (polyomavirus T antigen [T‐ag]– specific) and autoimmune (histone‐specific) T cells from normal individuals share structural and genetic characteristics with those from patients with systemic lupus erythematosus (SLE).

Methods

Histone‐specific T cells were generated by stimulation of peripheral blood mononuclear cells (PBMCs) with nucleosome–T‐ag complexes and were subsequently maintained by pure histones. T‐ag–specific T cell clones were initiated and maintained by T‐ag. The frequencies of circulating histone‐ and T‐ag–specific T cells were determined in healthy individuals and in SLE patients by limiting dilution of PBMCs. T cell receptor (TCR) gene usage and variable‐region structures were determined by complementary DNA sequencing. These sequences were compared between T‐ag– and histone‐specific T cells and between normal individuals and SLE patients for each specificity.

Results

Individual in vitro–expanded histone‐ and T‐ag–specific T cells from normal individuals displayed identical TCR Vα and/or Vβ chain third complementarity‐determining region (CDR3) sequences, indicating that they were clonally expanded in vivo. The frequencies of in vitro antigen‐responsive T‐ag– or histone‐specific T cells from normal individuals were similar to those from SLE patients. Although heterogeneous for variable‐region structure and gene usage, histone‐specific T cells from healthy individuals and SLE patients selected aspartic and/or glutamic acids at positions 99 and/or 100 of the Vβ CDR3 sequence.

Conclusion

Autoimmune T cells from healthy individuals can be activated by nucleosome– T‐ag complexes and maintained by histones in vitro. Such T cells possessed TCR structures similar to those from SLE patients, demonstrating that T cell autoimmunity to nucleosomes may be a latent property of the normal immune system.
Hydroxychloroquine concentration–response relationships in patients with rheumatoid arthritis
Authors: Munster Tino , Gibbs John P. , Shen Danny , Baethge Bruce A. , Botstein Gary R. , Caldwell Jacques , Dietz Fredrick , Ettlinger Robert , Golden Harvey E. , Lindsley Herbert , McLaughlin George E. , Moreland Larry W. , Roberts W. Neal , Rooney Theodore W. , Rothschild Bruce , Sack Marshall , Sebba Anthony I. , Weisman Michael , Welch Kathryn E. , Yocum David , Furst Daniel E.
Published: October 2002

Objective

A dose–response relationship for hydroxychloroquine (HCQ), in terms of the proportion of patients achieving the Paulus 20% criteria for improvement, had previously been observed in patients with rheumatoid arthritis (RA) receiving a 6‐week loading regimen of 400, 800, or 1,200 mg HCQ daily. This present retrospective analysis was performed to investigate possible relationships between the blood HCQ and HCQ‐metabolite concentrations and measures of efficacy and toxicity. In addition, we sought to ascertain whether further investigation of HCQ/HCQ‐metabolite levels might lead to testing of one of these substances as a new antirheumatic drug.

Methods

Patients with active RA (n = 212) began a 6‐week, double‐blind trial comparing 3 different doses of HCQ at 400, 800, or 1,200 mg/day, followed by 18 weeks of open‐label HCQ treatment at 400 mg/day. Patients were repeatedly evaluated for treatment efficacy and toxicity. Blood samples were available from 123 patients for analysis of HCQ, desethylhydroxychloroquine (DHCQ), desethylchloroquine (DCQ), and bisdesethylchloroquine (BDCQ) levels using high‐performance liquid chromatography. Achievement of the modified Paulus 20% improvement criteria for response in RA was used as the primary efficacy parameter. Spontaneously reported adverse events were categorized and analyzed as toxicity outcome variables. The relationship between response (efficacy and toxicity) and drug levels was evaluated using logistic regression analysis.

Results

The subset of patients with blood concentration data was equivalent to the larger study population in all demographic and outcome characteristics. The mean HCQ, DHCQ, and DCQ elimination half‐lives were 123, 161, and 180 hours, respectively. There was a positive correlation between the Paulus 20% improvement criteria response and blood DHCQ concentrations during weeks 1–6 (P < 0.001). A potential relationship between ocular adverse events and BDCQ levels was found (P = 0.036). Logistic regression analysis of adverse events data showed that adverse gastrointestinal events were associated with higher HCQ levels (P = 0.001–0.021) during weeks 1, 2, and 3.

Conclusion

There is a weak, but predictable, relationship between blood DHCQ concentrations and efficacy of treatment with HCQ. In addition, there is an association between gastrointestinal adverse events and elevated blood HCQ concentrations. Further investigation of these relationships is warranted to see if DHCQ may be introduced as a new antirheumatic drug.
Necessary role of phosphatidylinositol 3‐kinase in transforming growth factor β–mediated activation of Akt in normal and rheumatoid arthritis synovial fibroblasts
Authors: Kim Giok , Jun Jae‐Bum , Elkon Keith B.
Published: October 2002

Objective

Rheumatoid arthritis is a disease that, pathologically, is characterized by the progressive growth and invasion of the synovial pannus into the surrounding cartilage and bone. Many cytokines, including transforming growth factor β1 (TGFβ1), have been implicated in this process, but their mode of action is incompletely understood. The goal of the present study was to better understand the downstream signaling pathways of TGFβ in fibroblasts.

Methods

The role of phosphatidylinositol 3‐kinase (PI 3‐kinase) was determined by chemical inhibition with LY294002 or wortmannin. Activation of protein kinase B (Akt), c‐Jun N‐terminal kinases (JNKs), and extracellular signal–regulated kinases (ERKs) was evaluated by Western blot analysis using phospho‐specific antibodies.

Results

Exposure of fibroblasts to TGFβ rapidly induced activation of a kinase, Akt, that is known to inhibit apoptosis by a variety of pathways. Activation of Akt was blocked by the specific PI 3‐kinase inhibitor, LY294002, indicating that TGFβ‐mediated phosphorylation of Akt was dependent on PI 3‐kinase activation. This activation pathway was relatively selective for Akt, since inhibition of PI 3‐kinase failed to substantially modify activation of ERKs or JNKs in synovial fibroblasts. Inhibition of the PI 3‐kinase/Akt pathway resulted in impaired proliferation of synovial fibroblasts and partial attenuation of the protective effect of TGFβ on Fas‐mediated apoptosis.

Conclusion

TGFβ exerts its growth and antiapoptotic effects on fibroblasts, at least in part, by activation of the PI 3‐kinase/Akt pathway.
Medication toxicity among patients with ankylosing spondylitis
Authors: Ward Michael M. , Kuzis Susana
Published: October 2002

Objective

To determine the role of medication toxicity in the discontinuation of antirheumatic treatment among patients with ankylosing spondylitis (AS), and to compare the toxicity of different medications.

Methods

In a prospective longitudinal study of 241 patients with AS, we examined the duration of treatment and discontinuations due to side effects of new courses of sulfasalazine, methotrexate, ibuprofen, naproxen, indomethacin, diclofenac, piroxicam, nabumetone, and celecoxib.

Results

Of the 241 patients, 167 reported having a new treatment course of either sulfasalazine (n = 49), methotrexate (n = 19), ibuprofen (n = 105), naproxen (n = 57), indomethacin (n = 50), diclofenac (n = 38), piroxicam (n = 34), nabumetone (n = 27), or celecoxib (n = 25), for a total of 404 new treatment courses. Side effects were reported in 6.7% (ibuprofen) to 47.3% (methotrexate) of the courses. Between 2% (ibuprofen) and 23.5% (piroxicam) of courses were discontinued due to toxicity. For each medication, the duration of treatment was most often limited by factors other than toxicity. The time to drug discontinuation for any reason and the time to discontinuation due to toxicity did not differ between sulfasalazine and methotrexate. The time to drug discontinuation for any reason did not differ among nonsteroidal antiinflammatory drugs (NSAIDs), but discontinuations due to toxicity occurred earlier with piroxicam than with other NSAIDs.

Conclusion

Although medication toxicity is common among patients with AS, it is an uncommon cause of discontinuation of antirheumatic treatment.
Effects of video information on preoperative anxiety level and tolerability of joint lavage in knee osteoarthritis
Authors: Ayral Xavier , Gicquere Claudine , Duhalde Annie , Boucheny Denis , Dougados Maxime
Published: October 2002

Objective

To investigate the impact of video information on preoperative anxiety of patients scheduled to undergo joint lavage for knee osteoarthritis, and tolerability of the lavage.

Methods

A video film on joint lavage (duration 4 minutes, 20 seconds) was made by medical communication professionals, based on recommendations of the medical and paramedical staff of the Institute of Rheumatology. Patients diagnosed with knee osteoarthritis and scheduled for lavage were assigned, using a preestablished list of randomization, to either the video group or the no‐video group. In the operating room, preoperative anxiety level was measured on a 100‐mm visual analog scale (VAS), and tolerability was assessed using a 4‐grade scale.

Results

One hundred twelve patients (56 patients in each group) were included and completed the trial. Preoperative anxiety was lower by half for patients who had viewed the video (VAS 13 ± 20 versus 26 ± 27; P = 0.0056). Tolerability of knee lavage was also significantly better in the video group (very tolerable 91% versus 48%; P < 0.0001).

Conclusion

This prospective, controlled, randomized study confirms the usefulness of video information prior to an invasive rheumatology procedure.
A comparison of foreign authorship distribution in JASIST and the Journal of Documentation
Authors: He Shaoyi , Spink Amanda
Published: October 2002

This article reports findings from a study of the geographic distribution of foreign authors in the Journal of American Society for Information Science & Technology (JASIST) and Journal of Documentation (JDoc). Bibliographic data about foreign authors and their geographic locations from a 50‐year publication period (1950–1999) are analyzed per 5‐year period for both JASIST and JDoc. The distribution of foreign authors by geographic locations was analyzed for the overall trends in JASIST and JDoc. UK and Canadian authors are the most frequent foreign authors in JASIST. Authors from the United States and Canada are the most frequent foreign authors in JDoc. The top 10 geographic locations with highest number of foreign authors and the top 10 most productive foreign authors were also identified and compared for their characteristics and trends.
Pharmacoepidemiologic detection of calcium channel blocker‐induced change on digoxin clearance using multiple trough screen analysis
Authors: Suematsu Fumihiro , Yukawa Eiji , Yukawa Miho , Minemoto Masao , Ohdo Shigehiro , Higuchi Shun , Goto Yoshinobu
Published: October 2002

Nonlinear mixed effects modeling was used to estimate the effects of digoxin–calcium channel blockers (verapamil, diltiazem, nifedipine) in 336 serum levels gathered from 172 patients (104 male and 68 female) receiving oral digoxin as hospital in‐patients. The final model describing digoxin clearance (CL) was CL (l/day)=(87.9+2.71Ccr)0.872CCB0.880CHF0.937SPI0.854DFAC, where Ccr is the estimated creatinine clearance (ml/min); CCB=1 for concomitant administration of calcium channel blockers and CCB=zero otherwise; CHF=1 for the patients with congestive heart failure and CHF=zero otherwise; SPI=1 for concomitant administration of spironolactone and SPI=zero otherwise; DFAC=1 for administration of a half‐tablet of digoxin and DFAC=zero otherwise. Concomitant administration of calcium channel blockers resulted in a 13% decrease in digoxin relative clearance. Copyright © 2002 John Wiley & Sons, Ltd.
ELF magnetic fields increase amino acid uptake into Vicia faba L. Roots and Alter Ion movement across the plasma membrane
Authors: Stange B.C. , Rowland R.E. , Rapley B.I. , Podd J.V.
Published: October 2002

Vicia faba seedlings, subjected to a 10 µT 50 Hz square wave magnetic field for 40 min together with a radioactive pulse, showed a marked increase in amino acid uptake into intact roots. A more modest increase was observed with a 100 µT 50 Hz square wave. An increase in media conductivity at low field intensities from 10 µT 50 Hz square wave, 100 µT 50 Hz sine wave, and 100 µT 60 Hz square wave fields, indicated an alteration in the movement of ions across the plasma membrane, most likely due to an increase in net outflow of ions from the root cells. Similarly, marked elevation in media pH, indicating increased alkalinity, was observed at 10 and 100µT for both square and sine waves at both 50 and 60 Hz. Our data would indicate that low magnetic field intensities of 10 and 100 µT at 50 or 60 Hz can alter membrane transport processes in root tips. Bioelectromagnetics 23:347–354, 2002. © 2002 Wiley‐Liss, Inc.
Catabolic enzyme levels in bacteria grown on binary and ternary substrate mixtures in continuous culture
Authors: Rudolph John M. , Grady C. P. Leslie
Published: October 2002

Bacteria grow on multicomponent substrates in most natural and engineered environments. To advance our ability to model bacterial growth on such substrates, axenic cultures were grown in chemostats at a low specific growth rate and a constant total energy flux on binary and ternary substrate mixtures and were assayed for key catabolic enzymes for each substrate. The substrates were benzoate, salicylate, and glucose, and the enzymes were catechol 1,2‐dioxygenase, gentisate 1,2‐dioxygenase, and glucose‐6‐phosphate dehydrogenase, respectively. The binary mixtures were salicylate with benzoate and salicylate with glucose. Measurements were also made of oxygen uptake rate by whole cells in response to each substrate. The effects of the substrate mixture on the oxygen uptake rate paralleled the effects on the measured enzymes. Catechol 1,2‐dioxygenase exhibited a threshold response before synthesis occurred. Below the threshold flux of benzoate through the chemostat, either basal enzyme levels or nonspecific enzymes kept reactor concentrations too low for enzyme synthesis. Above the threshold, enzyme levels were linearly related to the fraction of the total energy flux through the chemostat due to benzoate. Gentisate 1,2‐dioxygenase exhibited a linear response to the salicylate flux when mixed with benzoate, but a threshold response when mixed with glucose. Glucose‐6‐phosphate dehydrogenase activity increased in direct proportion to the glucose flux through the chemostat over the entire range studied. The results from two ternary mixtures were consistent with those from the binary mixtures. © 2002 Wiley Periodicals, Inc. Biotechnol Bioeng 79: 188–199, 2002.
Conversion and toxicity characteristics of formaldehyde in acetoclastic methanogenic sludge
Authors: Gonzalez‐Gil G. , Kleerebezem R. , Lettinga G.
Published: October 2002

An unadapted mixed methanogenic sludge transformed formaldehyde into methanol and formate. The methanol to formate ratio obtained was 1:1. Formaldehyde conversion proceeded without any lag phase, suggesting the constitutive character of the formaldehyde conversion enzymes involved. Because the rate of formaldehyde conversion declined at increased formaldehyde additions, we hypothesized that some enzymes and/or cofactors might become denatured as a result of the excess of formaldehyde. Furthermore, formaldehyde was found to be toxic to acetoclastic methanogenesis in a dual character. Formaldehyde toxicity was partly reversible because once the formaldehyde concentration was extremely low or virtually removed from the system, the methane production rate was partially recovered. Because the degree of this recovery was not complete, we conclude that formaldehyde toxicity was partly irreversible as well. The irreversible toxicity likely can be attributed to biomass formaldehyde‐related decay. Independent of the mode of formaldehyde addition (i.e., slug or continuous), the irreversible toxicity was dependent on the total amount of formaldehyde added to the system. This finding suggests that to treat formaldehyde‐containing waste streams, a balance between formaldehyde‐related decay and biomass growth should be attained. © 2002 Wiley Periodicals, Inc. Biotechnol Bioeng 79: 314–322, 2002.
Enhancement of a two‐phase partitioning bioreactor system by modification of the microbial catalyst: Demonstration of concept
Authors: Vrionis H. A. , Kropinski A. M. , Daugulis A. J.
Published: October 2002

Application of two‐phase partitioning bioreactors (TPPB) to the degradation of phenol and xenobiotics has been limited by the fact that many organic compounds that would otherwise be desirable delivery solvents can be utilized by the microorganisms employed. The ability to metabolize the solvent itself could interfere with xenobiotic degradation, limiting remediation efficiency, and hence represents a microbial characteristic incompatible with process goals. To avoid the issue of bioavailability, previous TPPB applications have relied on complex and often expensive delivery solvents or suboptimal catalyst–solvent pairings. In an effort to enhance TPPB activity and applicability, a genetically engineered derivative of Pseudomonas putida ATCC 11172 mutated in its ability to utilize medium‐chain‐length alcohols was generated (AVP2) and applied as the catalyst within a TPPB system with decanol as the delivery solvent. Kinetic analysis verified that the genetic alteration had not negatively affected phenol degradation. The volumetric productivity of AVP2 (0.48 g/L h−1) was equivalent to that seen for wild‐type ATCC 11172 (0.51 g/L h−1), but a comparison of initial cell concentrations and yields revealed an improved phenol‐degrading efficiency for the mutant under process conditions. Yield coefficients, cell dry weight, and viable count determinations all confirmed the stability of the modified phenotype. This work illustrates the possibilities for TPPB process enhancement through a careful combination of genetic modification and solvent selection. © 2002 Wiley Periodicals, Inc. Biotechnol Bioeng 79: 587–594, 2002.
Metabolic behavior of immobilized Candida guilliermondii cells during batch xylitol production from sugarcane bagasse acid hydrolyzate
Authors: Carvalho Walter , Silva Silvio S. , Converti Attilio , Vitolo Michele
Published: October 2002

Candida guilliermondii cells, immobilized in Ca‐alginate beads, were used for batch xylitol production from concentrated sugarcane bagasse hydrolyzate. Maximum xylitol concentration (20.6 g/L), volumetric productivity (0.43 g/L · h), and yield (0.47 g/g) obtained after 48 h of fermentation were higher than similar immobilized‐cell systems but lower than free‐cell cultivation systems. Substrates, products, and biomass concentrations were used in material balances to study the ways in which the different carbon sources were utilized by the yeast cells under microaerobic conditions. The fraction of xylose consumed to produce xylitol reached a maximum value (0.70) after glucose and oxygen depletion while alternative metabolic routes were favored by sub‐optimal conditions. © 2002 Wiley Periodicals, Inc. Biotechnol Bioeng 79: 165–169, 2002.
Mathematical analysis of solid–liquid mass transfer in a batch reactor for the enzymatic transformation of testosterone to 4AD
Authors: Patel Shwetal , Mehra Anurag
Published: October 2002

A previous mathematical analysis of mass transfer in a two‐phase (solid–liquid) batch reactor for enzymatic transformation of testosterone to 4AD (Pereira et al., 1987) is extended to incorporate the effect of convective mixing. The results of the analysis showed that for a given enzyme loading, the mass transfer resistance in the solid (a function of the bead size) and the intensity of convective mixing (as embodied in the mass transfer coefficient) are two parameters that can be varied such that the overall mass transfer rate from the solid to the liquid phase ensures optimal reactor performance. © 2002 Wiley Periodicals, Inc. Biotechnol Bioeng 79: 647–652, 2002.
Screening for peptide affinity ligands on CIM monoliths
Authors: Pflegerl K. , Podgornik A. , Berger E. , Jungbauer A.
Published: October 2002

Screening of peptide ligands for affinity chromatography usually involves incubation with the target protein in a batch system. In an additional step, peptides with fast binding kinetics have to be selected in respect to satisfactory performance under flow conditions on a support ensuring optimal three‐dimensional presentation of the peptide. We have developed a rapid screening system based on peptide synthesis and screening on CIM® disks. The disk size was minimized to fit into microplates usually applied for solid‐phase extraction. In combination with a vacuum manifold, semi‐automated peptide synthesis and screening for binding to a target protein under simulated chromatography conditions are possible. Various analytical methods can be applied for parallel and automated determination of the quantity, integrity, or activity of the target protein in the flow through or bound to the affinity support. This system also allows parallel screening for suitable chromatographic conditions like running buffer, washing, and elution conditions. © 2002 Wiley Periodicals, Inc. Biotechnol Bioeng 79: 733–740, 2002.
Hydrolysis of wheat starch and its effect on the Falling Number procedure: Mathematical model
Authors: Chang Shih‐Ying , Delwiche Stephen R. , Wang Nam Sun
Published: October 2002

A population balance model was developed for wheat starch hydrolysis to simulate the performance parameters of a viscosity‐based device, known as the Falling Number instrument. The instrument is widely used as an indirect means to gauge the level of preharvest sprout activity in cereal grains such as wheat and barley. The model consists of three competing kinetics: starch gelatinization, enzymatic hydrolysis, and enzyme thermal deactivation. Using established principles of starch rheology and fluid mechanics, the model simulates the velocity profiles of the falling stirrer, starch gel viscosity, and the Falling Number readings at various levels of α‐amylase. Model predictions for the velocity of the stirrer at any time during the downward fall, as well as the prediction of the total time needed for the fall, defined as the Falling Number, were in fair agreement with experimental measurements. There was better agreement between the modeled viscosity and the final viscosity of the starch gel as measured by a precision rheometer than there was with the measured Falling Number. © 2002 Wiley Periodicals, Inc. Biotechnol Bioeng 79: 768–775, 2002
Engineering of coordinated up‐ and down‐regulation of two glycosyltransferases of the O‐glycosylation pathway in Chinese hamster ovary (CHO) cells
Authors: Prati Elisabetta G. P. , Matasci Mattia , Suter Tobias B. , Dinter Andre , Sburlati Adriana R. , Bailey James E.
Published: October 2002

Production of O‐linked oligosaccharides that interact with selectins to mediate cell–cell adhesion occurs in one segment of a branched glycan biosynthesis network. Prior efforts to direct the branched pathway towards selectin‐binding oligosaccharides by amplifying enzymes in this branch of the network have had limited success, suggesting that metabolic engineering to simultaneously inhibit the competing pathway may also be required.

We report here the partial cloning of the CMP‐sialic, acid:Galβ1,3GalNAcα2,3‐sialyltransferase (ST3Gal I) gene from Chinese hamster ovary (CHO) cells and the simultaneous inhibition of expression of CHO cell ST3Gal I gene and overexpression of the human UDP‐GlcNAc:Galβ1,3GalNAc‐R β1,6‐N‐acetylglucosaminyltransferase (C2GnT) gene. A tetracycline‐regulated system adjoined to tricistronic expression technology allowed “one‐step” transient manipulation of multiple enzyme activities in the O‐glycosylation pathway of a previously established CHO cell line already engineered to express α1,3‐fucosyltransferase VI (α1,3‐Fuc‐TVI). Tetracycline‐regulated co‐expression of a ST3Gal I fragment, cloned in the antisense orientation, and of C2GnT cDNA resulted in inhibition of the ST3Gal I enzymatic activity and increase in C2GnT activity which varied depending on the extent of tetracycline reduction in the cell culture medium. This simultaneous regulated inhibition and activation of the two key enzyme activities in the O‐glycosylation pathway of mammalian cells is an important addition to the metabolic engineering field. © 2002 Wiley Periodicals, Inc. Biotechnol Bioeng 79: 580–585, 2002.
Anatomical variations of the sural nerve
Authors: Mahakkanukrauh Pasuk , Chomsung Ranida
Published: October 2002

An anatomical study of the formation of the sural nerve (SN) was carried out on 76 Thai cadavers. The results revealed that 67.1% of the SNs were formed by the union of the medial sural cutaneous nerve (MSCN) and the lateral sural cutaneous nerve (LSCN); the MSCN and LSCN are branches of the tibial and the common fibular (peroneal) nerves, respectively. The site of union was variable: 5.9% in the popliteal fossa, 1.9% in the middle third of the leg, 66.7% in the lower third of the leg, and 25.5% at or just below the ankle. One SN (0.7%) was formed by the union of the MSCN and a different branch of the common fibular nerve, running parallel and medial to but not connecting with the LSCN, which joined the MSCN in the lower third of the leg. The remaining 32.2% of the SNs were a direct continuation of the MSCN. The SNs ranged from 6–30 cm (mean = 14.41 cm) in length with a range in diameter of 3.5–3.8 mm (mean = 3.61 mm), and were easily located 1–1.5 cm posterior to the posterior border of the lateral malleolus. The LSCNs were 15–32 cm long (mean = 22.48 cm) with a diameter between 2.7–3.4 mm (mean = 3.22 mm); the MSCNs were 17–31 cm long (mean = 20.42 cm) with a diameter between 2.3–2.5 mm (mean = 2.41 mm). Clinically, the SN is widely used for both diagnostic (biopsy and nerve conduction velocity studies) and therapeutic purposes (nerve grafting) and the LSCN is used for a sensate free flap; thus, a detailed knowledge of the anatomy of the SN and its contributing nerves are important in carrying out these and other procedures. Clin. Anat. 15:263–266, 2002. © 2002 Wiley‐Liss, Inc.
Virtual reality simulations in Web‐based science education
Authors: Shin Young‐Suk
Published: October 2002

This article presents the educational possibilities of Web‐based science education using a desktop virtual reality (VR) system. A Web site devoted to science education for middle school students has been designed and developed in the areas of earth sciences: meteorology, geophysics, geology, oceanography, and astronomy. Learners can establish by themselves the pace of their lessons using learning contents considered learner level and they can experiment in real time with the concepts they have learned, interacting with VR environments that we provide. A VR simulation program developed has been evaluated with a questionnaire from learners after learning freely on the Web. This study shows that Web‐based science education using VR can be effectively used as a virtual class. When we consider the rapid development of VR technology and lowering of cost, the study can construct more immersive environments for the education in the near future. © 2002 Wiley Periodicals, Inc. Comput Appl Eng Educ 10: 18–25, 2002; Published online in Wiley InterScience (www.interscience.wiley.com.); DOI 10.1002/cae.10014
Impact of various intravascular ultrasound criteria for stent optimization on the six‐month angiographic restenosis
Authors: Hong Myeong‐Ki , Lee Cheol Whan , Kim June‐Hong , Kim Young‐Hak , Song Jong‐Min , Kang Duk‐Hyun , Song Jae‐Kwan , Kim Jae‐Joong , Park Seong‐Wook , Park Seung‐Jung
Published: October 2002

We evaluated the impact of different intravascular ultrasound (IVUS) criteria on 6‐month angiographic restenosis in 511 patients with 560 lesions. Seven IVUS criteria were evaluated in this study; stent area at lesion segment 1) ≥ 100% of distal reference lumen area, 2) ≥ 90% of distal reference lumen area, 3) ≥ 80% of average reference lumen area, 4) ≥ 90% of average reference lumen area, 5) ≥ 55% of average reference vessel area, 6) ≥ 7 mm2, and 7) ≥ 9 mm2. Using the relative measurement (criteria 1–5), the angiographic restenosis rate was not statistically different. However, absolute measurement of stent area ≥ 7 or 9 mm2 (criteria 6 and 7) were associated with significantly lower restenosis rate (14.8% vs. 30.9%, P = 0.001, and 13.5% vs. 24.6%, P = 0.006, respectively). In conclusions, using the relative measurement of IVUS criteria, the occurrence of angiographic restenosis might not be predicted. The absolute measurement of IVUS stent area was the predictor of angiographic restenosis. Cathet Cardiovasc Intervent 2002;56:178–183. © 2002 Wiley‐Liss, Inc.
Meeting Review: 2002 O'Reilly Bioinformatics Technology Conference
Authors: Counsell Damian
Published: October 2002

At the end of January I travelled to the States to speak at and attend
the first O'Reilly Bioinformatics Technology Conference .
It was a large, well‐organized and diverse meeting with an interesting history.
Although the meeting was not a typical academic conference, its style will,
I am sure, become more typical of meetings in both biological and computational
sciences.

Speakers at the event included prominent bioinformatics researchers such
as Ewan Birney, Terry Gaasterland and Lincoln Stein; authors and leaders in
the open source programming community like Damian Conway and Nat Torkington;
and representatives from several publishing companies including the Nature
Publishing Group, Current Science Group and the President of O'Reilly
himself, Tim O'Reilly. There were presentations, tutorials, debates,
quizzes and even a ‘jam session’ for musical bioinformaticists.
Copyright ©2002 John Wiley & Sons, Ltd.
Innovations in parenting support: an evaluation of the YMCA's ‘Parenting Teenagers’ initiative
Authors: Roker Debi , Richardson Helen
Published: October 2002

This paper describes the evaluation of a three year Initiative run by the YMCA. The aim of the Initiative was to set up 30 different projects in YMCA centres in England, to provide help and support to the parents of teenagers. The Initiative was evaluated by the Trust for the Study of Adolescence. Funding was agreed for 29 projects, which included group‐based courses, ‘Dads and Lads’ projects, mediation schemes, transition evenings, and families and computing courses. A variety of outcomes from these projects are identified, both for parents, young people, project workers, and the YMCA as an organisation. Key issues and learning points from the Initiative are also identified. Finally, some general comments are made about strategies to provide support to the parents of teenagers. Copyright © 2002 John Wiley & Sons, Ltd.