bluuebunny/crossref_metadata_2025 huggingface dataset:
A study of curative interactions in the presence of cobalt(II) stearate
Authors: Jóna E. , Ondrušová D. , Pajtášová M. , P. Šimon  , Michálek J.
Published: August 2002

The curative interactions with the participation of dicyclohexylbenzothiazole‐2‐sulfenamide (DCBS), stearic acid (SA), ZnO, S, and Co(II) stearate (octadecanoate‐CoC18) as adhesive promoter have been investigated by means of DSC calorimetry, EPR, and IR spectroscopy in the absence of rubber. It has been found that in the presence of CoC18, DCBS, and S, structural changes have been observed on the action of heat, which are connected with the formation of polysulfide complexes between Co2+ ions, DCBS fragments, and sulphur. In the presence of SA and ZnO in the five‐component system, zinc(II) octadecanoate is formed. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2936–2943, 2001
Poly(N‐vinylcaprolactam) gel/organic dye complexes as sensors for metal ions in aqueous salt solutions
Authors: Nasimova I. R. , Makhaeva E. E. , Khokhlov A. R.
Published: August 2002

The complex formation of organogels based on poly(N‐vinylcaprolactam) (PVCa) and organic dyes [5‐(4‐dimethylaminobenzylidene) rhodanine, α‐nitroso‐β‐naftol, and dithizone] and the properties of the complexes in salt aqueous solutions were studied. PVCa gels absorbed these dyes in organic media (ethanol and chloroform). Our main focus was the behavior of the gel/dye complex immersed in a salt aqueous solution if the dye was the chelating ligand for metal ions. The behavior of the PVCa/dithizone (Dz)/chloroform system was studied in AgNO3 aqueous solutions. The absorption spectra of gel/dye and gel/dye/metal ion systems were investigated. The results obtained indicate that Ag+ ions penetrate the gel phase and that the Dz/silver complexes are indeed formed inside the gel. The dependence of the optical density of the gel/dye/metal ion systems on the AgNO3 concentration was observed. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 3238–3243, 2001
Opto‐thermal properties of fibers XVIII—Skin‐core structures variations in nylon 6 fibers due to different annealing conditions
Authors: Fouda I. M.
Published: August 2002

Nylon 6 fibers (Amilan) were annealed at constant temperature 140 ± 1°C for different time durations (1–10 h). Refractive indices have been previously measured interferometerically. Two independent techniques were used to study the optical anisotropy and density in these fibers. The first was the application of a multiple‐beam to determine the skin and core “mean” refractive indices and birefringence of the samples. The technique used multiple‐beam Fizeau fringes in transmission. The second technique was an acoustic method for measuring the density of the investigated fibers. The optical results were used to calculate the optical orientation factors for skin and core. The values of (Δα/3α0), which depend upon the molecular structure of the polymer, remain constant and in agreement with the previous published data. The density results were used to calculate the degree of crystallinity of nylon 6 fibers. In addition, the results were used to calculate the mean square density fluctuation, the harmonic mean polarizability of the dielectric, specific refractivity of the isotropic dielectric and the virtual refractive index. Also, the number of monomer units per unit volume, and n1 and n2, which are the refractive indices of fully oriented fiber, were calculated and found to be (1.606 and 1.534). Hermans optical orientation functions have been compared with the generalized Lorentz‐Lorenz equation given by de Vries. Microinterferograms and curves are given for illustration. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 3349–3360, 2001
Grafted stock synthesis of ABS at the ultimate high ratio of polybutadiene to poly(styrene‐co‐acrylonitrile)
Authors: Okaniwa Motoki , Suzuki Masanori
Published: August 2002

This study describes the emulsion grafting of styrene and acrylonitrile onto 60–70% polybutadiene (PB), in the presence or absence of tert‐dodecanetiol as a chain transfer reagent with a radical initiator, and the properties of the obtained grafted stock. There was no significant difference in terms of effect of the initiation mode on the grafting efficiency resulting from the high grafting reactivity of PB. However, the grafted stock with 70% PB prepared in the presence of tert‐dodecanetiol and the adequate selection of an initiation system gave a homogeneous dispersion of the PB particles into poly(styrene‐co‐acrylonitrile) (SAN) matrix. The initiation system involves tert‐butyl peroxylaurate, tert‐butyl peroxyacetate, and tert‐butyl peroxyisopropylcarbonate coupled with ferrous sulfate. The efficient coverage of the SAN grafted layer around 70% PB particles was observed by TEM to eventually give excellent impact resistance, high surface gloss, and good thermal resistance. The absence of tert‐dodecanetiol resulted in a toughness reduction of ABS. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 3462–3470, 2001
Therapeutic affinity adsorption of iron(III) with dye‐ and ferritin‐immobilized pHEMA adsorbent
Authors: Yavuz Handan , Arica Yakup , Deni̇zli̇ Adil
Published: August 2002

Microporous poly(2‐hydroxyethylmethacrylate) (pHEMA) films carrying cibacron blue F3GA, Congo red, and ferritin were prepared and used for iron(III) removal from human plasma. pHEMA films were produced by a photopolymerization of 2‐hydroxyethylmethacrylate in the presence of azobisisobutyronitrile. The reactive dye ligands cibacron blue F3GA, Congo red, and bioligand ferritin were then covalently attached to the pHEMA films. The maximum dye loadings were 1.07 and 0.80 μmol/cm2 for cibacron blue and Congo red, respectively. The maximum amount of ferritin attached was 1.04 × 10−3 μmol/cm2. Characterizations of the films were achieved by contact‐angle, water‐uptake, and scanning electron microscopy studies as well as atomic force microscopy images. The aqueous water‐uptake properties and contact angles (air underwater) of the pHEMA films did not change after derivatization with cibacron blue F3GA, Congo red, and ferritin. These hydrophilic films (contact angle = 45.3°), having a swelling ratio of 58% (w/w) and carrying cibacron blue F3GA, Congo red, and ferritin, were used in Fe(III) removal studies. The maximum amounts of Fe(III) removed from human plasma by cibacron blue F3GA‐, Congo red‐, and ferritin‐attached pHEMA films were 3.80 μg/cm2 for cibacron blue F3GA, 4.41 μg/cm2 for Congo red, and 8.1 μg/cm2 for ferritin‐attached films. Fe(III) ions could be repeatedly adsorbed and desorbed with these affinity pHEMA films without a noticeable loss in their Fe(III) adsorption capacity. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 186–194, 2001
Castor‐acrylated monomer 1H‐ and 13C‐nuclear magnetic resonance spectral assignments
Authors: Brister E. H. , Jarrett W. , Thames S. F.
Published: August 2002

Castor‐acrylated monomer (CAM) NMR spectral assignments were made utilizing one‐ and two‐dimensional NMR techniques. The unique structure of CAM resulted in several novel chemical environments which were observed in the NMR spectra. Previously published vegetable oil and fatty acid ester NMR peak assignments were insufficient for complete identification of NMR peaks. Definitive peak assignments, particularly in the alkyl and alkene regions, are required for evaluation of CAM as a specialty comonomer in the synthesis of latex polymers for use as waterborne‐coating binders. The NMR peak assignments for CAM will allow the subsequent evaluation of the copolymerizability of CAM as well as the determination as to whether unsaturation is preserved during latex polymer synthesis. 1H‐ and 13C‐NMR spectra of CAM are provided with supporting evidence for the peak assignments and discussion of their relevance. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 1850–1854, 2001
New type of lithium poly(polyfluoroalkoxy)sulfonylimides as salts for PEO‐based solvent‐free electrolytes
Authors: Liu Da‐Fan , Nie Jin , Zhuo Lian‐Meng , Liu Lie‐Wei , Sonoda Takaaki
Published: August 2002

A new type of lithium salts, —SO2NLiSO2OCH2(CF2)nCH2Om— (LiPPFASI, where n = 2, 3, 4, 6, and 7), was used as salts in poly(ethylene oxide) (PEO)‐based solvent‐free electrolytes. The conductivity and electrochemical stability behaviors were studied. The results showed the electrolytes almost have a similar conductivity and the PEO–LiPPFASI (n = 3, EO/Li = 10) was the relatively better system under the experiment conditions. Moreover, most systems were found to be oxidatively stable up to 5.5 V versus Li/Li+ and the lithium deposition‐stripping process on the electrode was reversible for all the polymer electrolytes. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 1882–1885, 2001
Preparation of amphiphilic PS‐b‐PMAA diblock copolymer by means of atom transfer radical polymerization
Authors: Wang Guojian , Yan Deyue
Published: August 2002

Amphiphilic diblock copolymers of polystyrene‐b‐poly(methacrylic acid) were synthesized by means of atom transfer radical polymerization. First, the polystyrene with a bromine atom at the chain end (PS‐Br) was prepared using styrene as the monomer, 1‐bromoethyl benzene as the initiator, and CuCl/2,2′‐bipyridyl (bpy) as the catalyst ([1‐bromoethyl benzene]/[CuCl]/[bpy] = 1:1:3). The polymerization was well controlled. Second, the diblock copolymer of polystyrene‐b‐poly(tert‐butyl methacrylate) was synthesized also by atom transfer radical polymerization using PS‐Br as the macro‐initiator, CuCl/bpy as the catalyst, and tert‐butyl methacrylate (tBMA) as the monomer. Finally, the amphiphilic diblock copolymer, PS‐b‐PMAA, was obtained by hydrolysis of PS‐b‐PtBMA under the acid condition. The molecular weight and the structure of aforementioned copolymers were characterized with gel permeation chromatography, infrared, and nuclear magnetic resonance. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 2381–2386, 2001
SEM study of a polystyrene/clay nanocomposite
Authors: Fan Jiaqi , Liu Suhuai , Chen Guangming , Qi Zongneng
Published: August 2002

We carried out a scanning electron microscopy study to investigate the morphology of a polystyrene (PS)/montmorillonite nanocomposite. Monodispersed spherical particles, about 200 nm in diameter, were observed when PS/montmorillonite powder was dispersed in water, whereas planar silicate sheets were found for cetyltrimethylammonium bromide‐exchange montmorillonite. The fracture surface of a PS/clay nanocomposite pellet sample showed a lot of fibrils rather than the smooth surface of a pure PS pellet. After the PS/clay nanocomposite pellet was chemically etched, flaky montmorillonite particles were homogeneously dispersed in the PS matrix. A film sample, prepared by the pressing of the PS/clay nanocomposite melt, revealed that the montmorillonite primary particles oriented parallel to the surface, and the corresponding X‐ray diffraction distribution map of silicon atoms confirmed that the dispersed particles were montmorillonite primary particles. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 66–69, 2002
Interpolyelectrolyte complex of poly(2‐vinylpyridinium chloride) and poly(sodium phosphate)
Authors: Acar Nermin
Published: August 2002

A polyelectrolyte complex (PEC) was formed by mixing aqueous solutions of the polyanion poly(sodium phosphate) with the polycation poly(2‐vinylpyridinium chloride). Conductometric and potentiometric titrations indicated the electrochemical end point of each titration. In all cases the end point occurred at a unit molar ratio of polyanionic to polycationic groups that was approximately one. The stoichiometry was also confirmed by analysis of the supernatant liquid in conjunction with the weights of the initial components and complex. An analysis showed that the starting materials were regenerated after dissolution of the complex with a 2M HCl solution. The interaction of the bivalent cupric ions with PEC were also investigated. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 3022–3028, 2002; DOI 10.1002/app.2332
Mechanical and thermal properties of acrylic fibers crosslinked with disulfonyl azides
Authors: Baker D. A. , East G. C. , Mukhopadhyay S. K.
Published: August 2002

A novel method for the crosslinking of acrylic fibers was devised, which uses disulfonyl azides as crosslinking agents. This is a fiber‐finishing process in which 1,6‐hexanedisulfonyl azide, 1,3‐benzenedisulfonyl azide, 4,4‐biphenyldisulfonyl azide, 1,5‐naphthalenedisulfonyl azide, and 2,6‐naphthalenedisulfonyl azide were applied to an acrylic fiber (Courtelle) and thermally treated to bring about crosslinking. A study was made of the mechanical and thermal properties of the crosslinked fibers and of the abrasion and pilling performance of the associated fabrics. Crosslinking brought about significant improvements in the initial modulus, resistance to abrasion, pilling performance, and thermal stability of the fibers. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 1309–1319, 2002; DOI 10.1002/app.2349
Changes in population parameters and behaviour of blue cod (Parapercis colias; Pinguipedidae) in Long Island—Kokomohua Marine Reserve, Marlborough Sounds, New Zealand
Authors: Davidson R.J.
Published: August 2002

With the establishment of the 619‐ha Long Island—Kokomohua Marine Reserve in April 1993, a biological monitoring programme designed to investigate changes due to the total no‐take legislation applied to the reserve was initiated.

Size, distribution and behaviour of blue cod (Parapercis colias; Pinguipedidae) were investigated using baited hooks at reserve and control rubble bottom habitats annually from 1993 to 2000. Blue cod abundance was estimated using visual diver strip transects annually for a period of 9 years from 1992 to 2001.

A total of 5628 blue cod (2436 reserve and 3192 control specimens) were captured, measured and released. Two years after the reserve was established, the average size of blue cod was 22.4 mm larger inside the reserve compared with control sites outside it.

Over the duration of the study, the mean length of blue cod captured using baited hooks increased in the no‐take reserve, but declined at the control sites. By the end of the study, in April 2000, the proportion of large blue cod >330 mm in length in the reserve was 35% compared with <1% at the control sites, where recreational fishing activities occurred.

Blue cod catch rates from experimental fishing in the reserve increased within 11 months of removal of recreational fishing activities and continued to increase up to 47 months, in contrast to the control areas where recreational fishing was permitted, catch rates remained consistently low. Increased catch rates in the reserve were not due to increased blue cod abundance, rather an increase in the proportion of naïve fish in the population.

From March 1998 to the end of the study, the density of blue cod in the reserve was significantly higher compared with the control sites. This increase was primarily due to an increase in the density of larger blue cod >300 mm length in the reserve and a corresponding small decline in the density of these larger fish at the control sites.

It is concluded that the cessation of recreational fishing in the reserve had resulted in an increase in blue cod size, catch rate and abundance and also in a change to blue cod behaviour.

Copyright © 2001 John Wiley & Sons, Ltd.
Cellular origin of endochondral ossification from grafted periosteum
Authors: Ueno Takaaki , Kagawa Toshimasa , Mizukawa Nobuyoshi , Nakamura Hiroaki , Sugahara Toshio , Yamamoto Toshio
Published: August 2002

Grafted periosteum is known to have potential for heterotopic bone formation by endochondral ossification. Although osteochondrogenic cells have been thought to originate from the osteogenic layer in grafted periosteum, no histological report has yet demonstrated this. The present study was designed to elucidate the origin of chondrogenesis preceding bone formation in grafted periosteum. Periostea harvested from young Japanese white rabbits' tibiae were grafted into suprahyoid muscles and examined radiographically and histologically at postoperative days 1, 7, 9, 14, 21, and 35. Normal periostea and tibial graft site were also examined. Surgical harvesting of the periosteum split and damaged its osteogenic layer but retained the fibrous layer intact. Most of the osteoblasts remained on the tibial bone surface, and only few cells of the osteogenic layer were present in grafted tissue. By the seventh day after grafting, the fibrous layer had thickened. The fibroblastic cells in the fibrous layer had significantly increased in number (P < 0.01) and were positively stained for proliferating cell nuclear antigen. These cells exhibited alkaline phosphatase activity at day 9. The differentiated chondrocytes had formed cartilage at postoperative day 14. Cells in the osteogenic layer appeared necrotic and subsequently disappeared. Following postoperative day 21, cartilage was replaced by trabecular bone. Bone formation was completed by 35 days. An X‐ray analysis at this time also revealed new bone formation. These findings indicate that grafted periosteum forms bone by endochondral ossification and that the cells of the fibrous layer play essential roles in chondrogenesis that precedes such bone formation. Anat Rec 264:348–357, 2001. © 2001 Wiley‐Liss, Inc.
GABA‐, glycine‐, and glutamate‐immunoreactive bouton profiles in apposition to neurons of the central cervical nucleus in the rat
Authors: Ragnarson Birger , Yi Seong Joon , Ulfhake Brun , Grant Gunnar
Published: August 2002

The neurons of the central cervical nucleus (CCN) convey information about the position and movements of the head, and receive excitatory input from dorsal neck muscles and the labyrinth. Both of these afferent sources form glutamatergic synaptic contacts with CCN neurons. However, these sensory afferent sources can also inhibit CCN neurons. To further elucidate the synaptic organization, we made an electron microscopic investigation, identifying and evaluating the relative frequency of bouton profiles containing the inhibitory transmitters GABA and glycine in apposition to identified CCN neurons. In addition, labeling for glutamate was performed. The identification of the CCN neurons was made possible by injections of retrograde tracer substances into the cerebellum. These substances were made visible by preembedding immunocytochemistry or postembedding immunogold staining. Such staining was also used to detect the three amino acids that were found in boutons apposed to the identified neurons (cf. Örnung et al., J. Comp. Neurol. 1996;365:413–426; Lindå et al., J. Comp. Neurol. 2000;425:10–23). Due to the relatively poor transport of the tracer substances into dendrites of the CCN neurons, the analysis was restricted to the cell body and included bouton profiles in direct apposition to the soma membrane. Data from 10 CCN neurons revealed that about 50% of the apposing bouton profiles were immunoreactive for GABA, and about 34% for glycine. In four neurons, the degree of colocalization of GABA and glycine was determined to be close to 30%. Thus, the vast majority of glycine‐labeled profiles also contained GABA, while a considerable fraction of the profiles were immunoreactive for only GABA. The values for glycine immunoreactive bouton profiles presented here may represent somewhat low estimates, depending on the method used. Data from four neurons showed that about 18% of the profiles were labeled for glutamate. The large fraction of purely GABA immunoreactive profiles, or at least a substantial group of them, is suggestive of their derivation from axons descending from the brainstem. Anat Rec 266:226–233, 2002. © 2002 Wiley‐Liss, Inc.
Horizontally oriented clusters of multiple chondrons in the superficial zone of ankle, but not knee articular cartilage
Authors: Schumacher Barbara L. , Su Jui‐Lan , Lindley Kathy M. , Kuettner Klaus E. , Cole Ada A.
Published: August 2002

Osteoarthritis is a progressive disease that is initiated at the surface of articular cartilage and proceeds to destroy the entire depth of the cartilage. The prevalence of osteoarthritis varies in different joints; e.g., the ankle joint has a very low prevalence of the disease compared to the knee joint. To better understand any inherent differences between the articular cartilage of the ankle and that of the knee that would account for the difference in occurrence of osteoarthritis, studies were undertaken to examine differences between the superficial zones in these two joint cartilages obtained from human donors. Chondrocytes in the superficial zones of the normal ankle (talocrural) and the normal knee (tibiofemoral) joints were identified with a monoclonal antibody specific for the superficial zone protein (SZP). When the chondrocytes from both joints were compared in serial horizontal sections, the chondrocytes in the superficial zone of the knee cartilage were seen either as isolated single cells or as doublets. However, the chondrocytes within the superficial zone of normal ankle cartilage were arranged in planar clusters containing multiple chondrons composed of 2–13 cells. There were no detectable differences in the chondrocyte clusters in the superficial zone of the ankle with respect to age, gender, or site on the cartilage surface. Adjacent to a lesion in an ankle joint with degenerative changes, the clusters were larger, containing up to 22 chondrocytes. This is the first report documenting the presence of multiple chondrons in the superficial zone of normal human adult articular cartilage. Anat Rec 266:241–248, 2002. © 2002 Wiley‐Liss, Inc.
Prenatal development of the human mandible
Authors: Lee Suk Keun , Kim Yeon Sook , Oh Hee Soo , Yang Kyu Ho , Kim Eun Cheol , Chi Je Geun
Published: August 2002

In an effort to better understand the interrelationship of the growth and development pattern of the mandible and condyle, a sequential growth pattern of human mandibles in 38 embryos and 111 fetuses were examined by serial histological sections and soft X‐ray views. The basic growth pattern of the mandibular body and condyle appeared in week 7 of fertilization. Histologically, the embryonal mandible originated from primary intramembranous ossification in the fibrous mesenchymal tissue around the Meckel cartilage. From this initial ossification, the ramifying trabecular bones developed forward, backward and upward, to form the symphysis, mandibular body, and coronoid process, respectively. We named this initial ossification site of embryonal mandible as the mandibular primary growth center (MdPGC). During week 8 of fertilization, the trabecular bone of the mandibular body grew rapidly to form muscular attachments to the masseter, temporalis, and pterygoid muscles. The mandible was then rapidly separated from the Meckel cartilage and formed a condyle blastema at the posterior end of linear mandibular trabeculae. The condyle blastema, attached to the upper part of pterygoid muscle, grew backward and upward and concurrent endochondral ossification resulted in the formation of the condyle. From week 14 of fertilization, the growth of conical structure of condyle became apparent on histological and radiological examinations. The mandibular body showed a conspicuous radiating trabecular growth pattern centered at the MdPGC, located around the apical area of deciduous first molar. The condyle growth showed characteristic conical structure and abundant hematopoietic tissue in the marrow. The growth of the proximal end of condyle was also approximated to the MdPGC on radiograms. Taken together, we hypothesized that the MdPGC has an important morphogenetic affect for the development of the human mandible, providing a growth center for the trabecular bone of mandibular body and also indicating the initial growth of endochondral ossification of the condyle. Anat Rec 263:314–325, 2001. © 2001 Wiley‐Liss, Inc.
Molecular structure of the peritrophic membrane (PM): Identification of potential PM target sites for insect control
Authors: Wang Ping , Granados Robert R.
Published: August 2002

Peritrophic membranes (PMs) are an invertebrate‐unique structure that lines the digestive tract, playing important roles in facilitating food digestion and providing protection to the gut epithelium. The importance of PMs in insects has been recognized ever since its presence was identified 200 years ago. In the last 5 years, significant progress towards understanding the PM molecular structure and the mechanism for PM formation has been made. Recent studies on Type 1 PMs from lepidopteran larvae have suggested a model for the PM molecular structure and formation. The important physiological functions of the PM suggest that PMs can be a significant structural target for insect control and the current understanding of the structure of lepidopteran larval PMs has provided us with potential opportunities for targeting the PM by various mechanisms. Arch. Insect Biochem. Physiol. 47:110–118, 2001. © 2001 Wiley‐Liss, Inc.
Pharmacological characterization of STKR, an insect G protein‐coupled receptor for tachykinin‐like peptides
Authors: Torfs Herbert , Oonk Hendrica B. , Broeck Jozef Vanden , Poels Jeroen , Van Poyer Wendy , De Loof Arnold , Guerrero Felix , Meloen Robbert H. , Åkerman Karl , Nachman Ronald J.
Published: August 2002

STKR is a G protein–coupled receptor that was cloned from the stable fly, Stomoxys calcitrans. Multiple sequence comparisons show that the amino acid sequence of this insect receptor displays several features that are typical for tachykinin (or neurokinin, NK) receptors. Insect tachykinin‐related peptides, also referred to as “insectatachykinins,” produce dose‐dependent calcium responses in Drosophila melanogaster Schneider 2 cells, which are stably transfected with this receptor (S2‐STKR). These responses do not depend on the presence of extracellular Ca2+‐ions. A rapid agonist‐induced increase of inositol 1,4,5‐trisphosphate (IP3) is observed. This indicates that the agonist‐induced cytosolic Ca2+‐rise is caused by a release of Ca2+ ions from intracellular calcium stores. The pharmacology of STKR is analyzed by studying the effects of the most important antagonists for mammalian NK‐receptors on STKR‐expressing insect cells. The results show that spantide II, a potent substance P antagonist, is a real antagonist of insectatachykinins on STKR. We have also tested the activity of a variety of natural insectatachykinin analogs by microscopic image analysis of calcium responses in S2‐STKR cells. At a concentration of 1 μM, almost all natural analogs produce a significant calcium rise in stable S2‐STKR cells. Interestingly, Stc‐TK, an insectatachykinin that was recently discovered in the stable fly (S. calcitrans), also proved to be an STKR‐agonist. Stc‐TK, a potential physiological ligand for STKR, contains an Ala‐residue (or A) instead of a highly conserved Gly‐residue (or G). Arch. Insect Biochem. Physiol. 48:39–49, 2001. © 2001 Wiley‐Liss, Inc.
Increased prevalence of renal disease in systemic lupus erythematosus families with affected male relatives
Authors: Stein Catherine M. , Olson Jane M. , Gray‐McGuire Courtney , Bruner Gail R. , Harley John B. , Moser Kathy L.
Published: August 2002

Objective

To distinguish familial differences from sex‐related differences in the clinical manifestations of systemic lupus erythematosus (SLE).

Methods

A total of 372 affected individuals from 160 multiplex SLE pedigrees were analyzed. Twenty‐five of these pedigrees contained at least 1 affected male relative. Comparisons of the presence of each of the 11 1982 American College of Rheumatology criteria for SLE were made between female family members with affected male relatives and those without affected male relatives, using Fisher's exact tests.

Results

The presence of renal disease was significantly increased in female family members with an affected male relative when compared with those with no affected male relative (68% and 43%, respectively; P = 0.002). This trend remained after stratifying by race and was most pronounced in European Americans. A familial basis for differences in hematologic and immunologic manifestations was also suggested, while arthritis and dermatologic features appeared to be most influenced by sex.

Conclusios

Our results demonstrate that the increased prevalence of renal disease previously reported in men with SLE is, in large part, a familial rather than sex‐based difference, at least in multiplex SLE families. Distinguishing familial from sex‐related differences may facilitate efforts to understand the genetic and hormonal factors that underlie this complex autoimmune disease.
Genome scan for quantity of hand osteoarthritis: The Framingham study
Authors: Demissie S. , Cupples L. A. , Myers R. , Aliabadi P. , Levy D. , Felson D. T.
Published: August 2002

Objective

To search for markers linked to quantity of radiographic hand osteoarthritis (OA) in the Framingham Heart Study.

Methods

The sample included 684 original cohort members and 793 offspring in 296 pedigrees. Radiographic OA features evaluated included the Kellgren/Lawrence (K/L) score, osteophytes, and joint space narrowing (0–3 scale). Four quantitative phenotypes were computed from these measurements: sum of K/L scores across hand joints, sum of osteophyte scores, sum of joint space narrowing scores, and proportion of affected joints. Prior to linkage analysis, these phenotypes were adjusted for age using a linear regression analysis from which standardized residuals were computed. The regression analysis was performed separately for each sex and each generation. The variance component model (SOLAR) was then applied to the normalized scores of the residuals.

Results

The average age was 62 years for the original cohort and 54 years for the offspring. Fifty percent of the original cohort and 30% of their offspring had at least 1 affected joint (K/L score ≥2). Heritability ranged from 28% (proportion of joints affected with OA) to 34% (sum of K/L scores). Eight chromosomal regions indicated suggestive linkage (multipoint logarithm of odds [LOD] score >1.5) for at least 1 phenotype; LOD scores were highest for joint space narrowing, with a multipoint LOD score = 2.96 on chromosome 1p at D1S1665. Chromosomes 7, 9, 13, and 19 indicated consistent LOD score elevation for multiple OA phenotypes.

Conclusion

There are several chromosomes that may harbor OA susceptibility genes. Further investigation of these regions using larger studies and finer maps will be important to confirm linkage.
Cognitive space and information space
Authors: Newby Gregory B.
Published: August 2002

This article works towards realization of exosomatic memory for information systems. In exosomatic memory systems, the information spaces of systems will be consistent with the cognitive spaces of their human users. A method for measuring concept relations in human cognitive space is presented: the paired comparison survey with Principal Components Analysis. A study to measure the cognitive spaces of 16 research participants is presented. Items measured include relations among seven TREC topic statements as well as 17 concepts from the topic statements. A method for automatically generating information spaces from document collections is presented that uses term cooccurrence, eigensystems analysis, and Principal Components Analysis. The extent of similarity between the cognitive spaces and the information spaces, which were derived independently from each other, is measured. A strong similarity between the information spaces and the cognitive spaces are found, indicating that the methods described may have good utility for working towards information systems that operate as exosomatic memories.
The self‐organization of the European Information Society: The case of “biotechnology”
Authors: Leydesdorff Loet , Heimeriks Gaston
Published: August 2002

Fields of technoscience like biotechnology develop in a network mode: disciplinary insights from different backgrounds are recombined as competing innovation systems are continuously reshaped. The ongoing process of integration at the European level generates an additional network of transnational collaborations. Using the title words of scientific publications in five core journals of biotechnology, multivariate analysis is used to distinguish between the intellectual organization of the publications in terms of title words and the institutional network in terms of addresses of documents. The interaction among the representation of intellectual space in terms of words and co‐words, and the potentially European network system is compared with the document sets with American and Japanese addresses. The European system can also be decomposed in terms of the contributions of member states. Whereas a European vocabulary can be made visible at the global level, this communality disappears by this decomposition. The network effect at the European level can be considered as institutional more than cognitive.
A reliability semi‐Markov model involving geometric processes
Authors: Pérez‐Ocón Rafael , Torres‐Castro Inmaculada
Published: August 2002

We consider a semi‐Markov process that models the repair and maintenance of a repairable system in steady state. The operating and repair times are independent random variables with general distributions. Failures can be caused by an external source or by an internal source. Some failures are repairable and others are not. After a repairable failure, the system is not as good as new and our model reflects that. At a non‐repairable failure, the system is replaced by a new one. We assume that external failures occur according to a Poisson process. Moreover, there is an upper limit N of repairs, it is replaced by a new system at the next failure, regardless of its type. Operational and repair times are affected by multiplicative rates, so they follow geometric processes. For this system, the stationary distribution and performance measures as well as the availability and the rate of occurrence of different types of failures in stationary state are calculated. Copyright © 2002 John Wiley & Sons, Ltd.
Absence of pharmacokinetic interaction between orally co‐administered naproxen sodium and diphenhydramine hydrochloride
Authors: Toothaker R.D. , Barker S.H. , Gillen M.V. , Helsinger S.A. , Kindberg C.G. , Hunt T.L. , Powell J.H.
Published: August 2002

The potential for a pharmacokinetic interaction between naproxen and diphenhydramine was examined in a randomized three‐way crossover design with a 1‐week washout between dosing. Single oral doses of 220 mg of naproxen sodium and 50 mg of diphenhydramine hydrochloride were given separately and together to 30 healthy male and female subjects. Heparinized blood samples obtained for 48 h postdose were assayed for plasma naproxen and diphenhydramine concentrations using validated high‐performance liquid chromatography (HPLC) and gas chromatography (GC) assay methods, respectively. The area under the plasma concentration–time curve (AUC), maximum plasma concentrations (Cmax), time of Cmax (Tmax) and terminal exponential half‐life (t1/2,z), were analysed for significant treatment differences by analysis of variance (ANOVA). Based on absence of significant treatment effects on AUC and Cmax, single‐dose oral co‐administration of 220 mg of naproxen sodium with 50 mg of diphenhydramine hydrochloride does not alter the pharmacokinetics of either naproxen or diphenhydramine. Significant treatment differences seen for naproxen Tmax (0.3 h, males only) and diphenhydramine t1/2,z (0.8 h, females only) were minor and are unlikely to have therapeutic consequences. Thus, efficacy and safety of concomitant naproxen and diphenhydramine should not be altered due to a pharmacokinetic interaction. Copyright © 2000 John Wiley & Sons, Ltd.
Linezolid absolute bioavailability and the effect of food on oral bioavailability
Authors: Welshman Ian R. , Sisson Theresa A. , Jungbluth Gail L. , Stalker Dennis J. , Hopkins Nancy K.
Published: August 2002

Linezolid is a novel oxazolidinone antibiotic that has a spectrum of activity encompassing a variety of Gram‐positive bacteria. The objectives of this study were twofold: (1) to compare the absorption of linezolid tablets given immediately following a high‐fat meal with the absorption of tablets administered while fasting, and (2) to assess the bioavailability of a 375‐mg oral dose given while fasting relative to a 375‐mg dose of linezolid sterile solution given intravenously. Venous blood samples were taken over the 48 h following the single dose administration of both the oral and intravenous (IV) treatment. Samples were subsequently frozen for the determination of linezolid concentrations by HPLC. The only statistically significant difference between the fasted and the fed treatment was in peak plasma concentration, with the mean Cmax for fasted subjects being 23% greater than that for subjects after consumption of a high‐fat meal. Comparable AUC0–∞ values were measured under both conditions, indicating that the overall extent of absorption is the same. Therefore, the difference in Cmax, while statistically significant, should not affect the therapeutic efficacy of linezolid when it is administered with food. There were no statistically significant differences in AUC0–∞, CL or half‐life between the fasted oral treatment and the intravenous treatment. As expected, Cmax was statistically different between the two treatments. However, the mean absolute bioavailability (F) of the tablet, using the IV sterile solution as the reference treatment, was 103% (±20%). Copyright © 2001 John Wiley & Sons, Ltd.
The same but different: an empirical investigation of the reducibility principle
Authors: Budescu David V. , Fischer Ilan
Published: August 2002

According to classical utility theory the valuation of any lottery should depend only on its outcomes and their respective probabilities, and should not be affected by the nature, complexity and structure of the chance mechanism. Previous research has documented systematic violations of this principle. For example, most subjects prefer lotteries in which the payoffs are contingent on the joint occurrence of multiple (high probability) events to simple lotteries, and lotteries in which the earlier stages offer higher probabilities than the later stages. We review the various violations of this principle and suggest a classification into two major types associated with misunderstanding of chance mechanisms and attitude towards the chance mechanism and process. In the present study 40 subjects were presented with 30 pairs of binary gambles. In any given pair the lotteries had identical outcomes and equal ‘reduced’ probabilities (and thus equal expected values). However, the chance mechanisms varied along a variety of factors such as the size of the sample space, the number of stages, temporal ordering, order of probabilities, their transparency and time constraints. Half the subjects saw lotteries involving gains and the other half considered only losses. After choosing one lottery in each pair, the subjects were asked to explain and justify their choices. The findings revealed systematic violations of the reducibility principle: subjects displayed a preference for lotteries with larger sample spaces, and for lotteries that allow quicker resolutions in the earlier stages. A clear distinction between some patterns of preferences in the gains and loss domains was revealed. In gambles involvinggainssubjects preferred to have the highest probability on the first stage (and the lowest probability on the last stage), but displayed the opposite preferences forlosses. A content analysis of the subjects' stated reasons for their choices identified eight major categories. The most frequently invoked were hope, fun, simplicity, stress and time. Copyright © 2001 John Wiley & Sons, Ltd.
Effects of exposure to low level radiofrequency fields on acetylcholine release in hippocampus of freely moving rats
Authors: Testylier G. , Tonduli L. , Malabiau R. , Debouzy J.C.
Published: August 2002

Some central cholinergic effects have been reported in animals after acute exposure to radiofrequency electromagnetic field at low intensity. We studied acetylcholine (ACh) release in the brain of freely moving rats exposed for 1 h during the day to a 2.45 GHz continuous wave radiofrequency field (RF) (2 or 4 mW/cm2) or exposed for 1 or 14 h during the night to a 800 MHz field modulated at 32 Hz (AM 200 mW/cm2). Measurements were performed by microdialysis using a membrane implanted through the upper CA1 region of the hippocampus. After irradiation with the 2.45 GHz RF, rats exposed at 2 mW/cm2 did not show a significant modification of Ach release, whereas those exposed at 4 mW/cm2 showed a significant 40% decrease in mean ACh release from hippocampus. This decrease was maximal at 5 h post exposure. Exposure to the 800 MHz RF for 1 h did not cause any significant effect, but exposure for 14 hrs induced a significant 43% decrease in ACh release during the period 11 p.m.–4 a.m. compared to control rats. In the control group we observed an increase of ACh release at the beginning of the night, which was linked to the waking period of rats. This normal increase was disturbed in rats exposed overnight to the 800 MHz RF. This work indicates that neurochemical modification of the hippocampal cholinergic system can be observed during and after an exposure to low intensity RF. Bioelectromagnetics 23:249–255, 2002. © 2002 Wiley‐Liss, Inc.
Modulatory effects of static magnetic fields on blood pressure in rabbits
Authors: Okano Hideyuki , Ohkubo Chiyoji
Published: August 2002

Acute effects of locally applied static magnetic fields (SMF) on pharmacologically altered blood pressure (BP) in a central artery of the ear lobe of a conscious rabbit were evaluated. Hypotensive and vasodilator actions were induced by a Ca2+ channel blocker, nicardipine (NIC). Hypertensive and vasoconstrictive actions were induced by a nitric oxide synthase (NOS) inhibitor, Nω‐nitro‐L‐arginine methyl ester (L‐NAME). The hemodynamic changes in the artery exposed to SMF were measured continuously and analyzed by penetrating microphotoelectric plethysmography (MPPG). Concurrently, BP changes in a central artery contralateral to that of the exposed ear lobe were monitored. SMF intensity was 1 mT and the duration of exposure was 30 min. A total of 180 experimental trials were carried out in 34 healthy adult male rabbits weighing 2.6–3.8 kg. Six experimental procedures were chosen at random: (1) sham exposure without pharmacological treatment; (2) SMF exposure alone; (3) decreased BP induced by a single intravenous (iv) bolus injection of NIC (100 μM/kg) without SMF exposure; (4) decreased BP induced by injection of NIC with SMF exposure; (5) increased BP induced by a constant iv infusion of L‐NAME (10 mM/kg/h) without SMF exposure; (6) increased BP induced by infusion of L‐NAME with SMF exposure. The results demonstrated that SMF significantly reduced the vasodilatation with enhanced vasomotion and antagonized the reduction of BP via NIC‐blocked Ca2+ channels in vascular smooth muscle cells. In addition, SMF significantly attenuated the vasoconstriction and suppressed the elevation of BP via NOS inhibition in vascular endothelial cells and/or central nervous system neurons. These results suggest that these modulatory effects of SMF on BP might, in part, involve a feedback control system for alteration in NOS activity in conjunction with modulation of Ca2+ dynamics. Bioelectromagnetics 22:408–418, 2001. © 2001 Wiley‐Liss, Inc.
Cytogenetic damage in human lymphocytes following GMSK phase modulated microwave exposure
Authors: d'Ambrosio Guglielmo , Massa Rita , Scarfi Maria Rosaria , Zeni Olga
Published: August 2002

The present study investigated, using in vitro experiments on human lymphocytes, whether exposure to a microwave frequency used for mobile communication, either unmodulated or in presence of phase only modulation, can cause modification of cell proliferation kinetics and/or genotoxic effects, by evaluating the cytokinesis block proliferation index and the micronucleus frequency. In the GSM 1800 mobile communication systems the field is both phase (Gaussian minimum shift keying, GMSK) and amplitude (time domain multiple access, TDMA) modulated. The present study investigated only the effects of phase modulation, and no amplitude modulation was applied. Human peripheral blood cultures were exposed to 1.748 GHz, either continuous wave (CW) or phase only modulated wave (GMSK), for 15 min. The maximum specific absorption rate (∼5 W/kg) was higher than that occurring in the head of mobile phone users; however, no changes were found in cell proliferation kinetics after exposure to either CW or GMSK fields. As far as genotoxicity is concerned, the micronucleus frequency result was not affected by CW exposure; however, a statistically significant micronucleus effect was found following exposure to phase modulated field. These results would suggest a genotoxic power of the phase modulation per se. Bioelectromagnetics 23:7–13, 2002. © 2002 Wiley‐Liss, Inc.
The “tale” of UmuD and its role in SOS mutagenesis†
Authors: Gonzalez Martín , Woodgate Roger
Published: August 2002

Recently, the Escherichia coli umuD and umuC genes have been shown to encode E. coli's fifth DNA polymerase, pol V (consisting of a heterotrimer of UmuD′2C). The main function of pol V appears to be the bypass of DNA lesions that would otherwise block replication by pols I–IV. This process is error‐prone and leads to a striking increase in mutations at sites of DNA damage. While the enzymatic properties of pol V are now only beginning to be fully appreciated, a great deal is known about how E. coli regulates the intracellular levels of the Umu proteins so that the lesion‐bypassing activity of pol V is available to help cells survive the deleterious consequences of DNA damage, yet keeps any unwarranted activity on undamaged templates to a minimum. Our review summarizes the multiple restrictions imposed upon pol V, so as to limit its activity in vivo and, in particular, highlights the pivotal role that the N‐terminal tail of UmuD plays in regulating SOS mutagenesis. BioEssays 24:141–148, 2002. Published 2002 Wiley Periodicals, Inc.
Intrinsic DNA bends: an organizer of local chromatin structure for transcription
Authors: Ohyama Takashi
Published: August 2002

DNA with a curved trajectory of its helix axis is called bent DNA, or curved DNA. Interestingly, biologically important DNA regions often contain this structure, irrespective of the origin of DNA. In the last decade, considerable progress has been made in clarifying one role of bent DNA in prokaryotic transcription and its mechanism of action. However, the role of bent DNA in eukaryotic transcription remains unclear. Our recent study raises the possibility that bent DNA is implicated in the “functional packaging” of transcriptional regulatory regions into chromatin. In this article, I review recent progress in bent DNA research in eukaryotic transcription, and summarize the history of bent DNA research and several subjects relevant to this theme. Finally, I propose a hypothesis that bent DNA structures that mimic a negative supercoil, or have a right‐handed superhelical writhe, organize local chromatin infrastructure to help the very first interaction between cis‐acting DNA elements and activators that trigger transcription. BioEssays 23:708–715, 2001. © 2001 John Wiley & Sons, Inc.