bluuebunny/crossref_metadata_2025 huggingface dataset:
Solvent‐based pressure‐sensitive adhesives for PVC sign and marking films
Authors: Czech Zbigniew
Published: August 2002

This article shows the influence of parameters such as acrylic acid, initiator content, molecular mass, viscosity, content of methyl acrylate, content of ethyl acrylate, and content of N‐vinyl caprolactam on such important parameters of pressure‐sensitive adhesives as shrinkage, plasticity, adhesion to the steel, and deformation. Pressure‐sensitive adhesives based on acrylic polymers and containing 2‐ethylhexyl acrylate, methyl acrylate, acrylic acid, and N‐vinyl caprolactam are used for production of self‐adhesives containing polyvinyl chloride carrier. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 3212–3219, 2001
Water–alcohol separation by pervaporation through zeolite‐modified poly(amidesulfonamide)
Authors: He Xumin , Chan Wing‐Hong , Ng Ching‐Fai
Published: August 2002

Pervaporation membranes were fabricated by blending different amount of zeolite NaA or NaX with three types of poly(amidesulfonamide) (PASA). The zeolite‐filled membranes were characterized by IR spectroscopy, SEM, sorption measurements, and wide‐angle X‐ray diffraction. By adding the proper amount of NaA into the polymer casting solutions, the resultant zeolite‐filled membranes exhibited improvement in both selectivity and permeability in the separation of 10% aqueous solutions of ethanol and propan‐1‐ol, as compared with the zeolite free membrane. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 1323–1329, 2001
Rheology, morphology, and mechanical and thermal properties of recycled PVC pipes
Authors: Sombatsompop N. , Thongsang S.
Published: August 2002

This article demonstrated the possibility of recycling PVC pipes by investigating the effect of adding PVC pipes (varying from 0 to 80 % wt) into two commercial PVC virgin grades on the rheological, morphological, mechanical, and thermal properties of the PVC blends. The results obtained showed an increase in the melt viscosity and no change in the die swell ratio as the concentration of the recycled PVC was increased. The die swell ratio was observed to increase with temperature, this being associated with the presence of gelation that occurred at high temperature. The optimum tensile and impact strengths were detected, the impact strength being explained by use of SEM micrographs of the fracture surface. The hardness result corresponded well to the density of the compounds. The glass transition, degradation, and heat‐deflection temperatures were also found to shift with the recycled PVC loading. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 2478–2486, 2001
Preparation and separation properties of polyamide nanofiltration membrane
Authors: Chen Shih‐Hsiung , Chang Dong‐Jang , Liou Rey‐May , Hsu Ching‐Shan , Lin Shiow‐Shyung
Published: August 2002

Utilizing an interfacial polymerization technique for the preparation of a polymeric composite nanofiltration membrane, both high permeation flux of water and high salt rejection can be achieved. Synthesis conditions, such as concentration of monomer, reaction time, and swelling agent, significantly affected the separation performance of composite membranes. The composite polyamide membrane had a permeation rate of ∼2–5 gallon/ft2/day (gfd) and a salt rejection rate of ∼94–99% when 2000 ppm aqueous salt solution was fed at 200 psi and 25°C. Also, a higher performance nanofiltration membrane could be prepared by suitably swelling the support matrix in the period of polymerization. The results of various feed concentrations showed that permeate flux decreased with increasing salt concentration in the feed solution. This result may be due to concentration polarization on the surface of polyamide membranes. The separation performance of polyamide membranes showed an almost independent relationship with operation pressure until it was up to 200 psi. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 1112–1118, 2002
In situ pultrusion of urea–formaldehyde matrix composites. I. Processability, kinetic analysis, and dynamic mechanical properties
Authors: Chen Chin‐Hsing , Lue Jun‐Yi , Yen Chih‐Chao
Published: August 2002

We conducted a feasibility study on the pultrusion of a glass‐fiber‐reinforced urea–formaldehyde (UF) composite using a proprietary method. The UF prepolymer synthesized in this study was prepared from blends of UF monomer and a curing agent (NH4Cl).The process feasibility, kinetic analysis, and dynamic mechanical properties of the glass‐fiber‐reinforced UF composites by pultrusion were investigated. From investigations of the long pot life of the UF prepolymer, the high reactivity of the UF prepolymer, and excellent fiber wet‐out, we found that the UF resin showed excellent process feasibility for pultrusion. A kinetic model, dα/dt = A exp(−E/RT)αm(1 − α)n, is proposed to describe the curing behavior of a UF resin. Kinetic parameters for the model were obtained from dynamic differential scanning calorimetry scans with a multiple‐regression technique. The dynamic storage modulus of the pultruded‐glass‐fiber‐reinforced UF composites increased with increasing die temperature, filler content and glass‐fiber content and with decreasing pulling rate. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 1242–1251, 2002
Immobilization of invertase onto crosslinked poly(p‐chloromethylstyrene) beads
Authors: Bahar T. , Tuncel A.
Published: August 2002

Invertase was immobilized onto poly(p‐chloromethylstyrene) (PCMS) beads that were produced by a suspension polymerization with an average size of 186 μm. The beads had a nonporous but reasonably rough surface. Because of this, a reasonably large external surface area (i.e., 14.1 m2/g) could be achieved with the proposed carrier. A two‐step functionalization protocol was followed for the covalent attachment of invertase onto the bead surface. For this purpose, a polymeric ligand that carried amine groups, polyethylenimine (PEI), was covalently attached onto the bead surface by a direct chemical reaction. Next, the free amine groups of PEI were activated by glutaraldehyde. Invertase was covalently attached onto the bead surface via the direct chemical reaction between aldehyde and amine groups. The appropriate enzyme binding conditions and the batch‐reactor performance of the immobilized enzyme system were investigated. Under optimum immobilization conditions, 19 mg of invertase was immobilized onto each gram of beads with 80% retained activity after immobilization. The effects of pH and temperature on the immobilized invertase activity were determined and compared with the free enzyme. The kinetic parameters KM and VM were determined with the Michealis–Menten model. KM of immobilized invertase was 1.75 folds higher than that of the free invertase. The immobilization caused a significant improvement in the thermal stability of invertase, especially in the range of 55–65°C. No significant internal diffusion limitation was detected in the immobilized enzyme system, probably due to the surface morphology of the selected carrier. This result was confirmed by the determination of the activation energies of both free and immobilized invertases. The activity half‐life of the immobilized invertase was approximately 5 times longer than that of the free enzyme. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 1268–1279, 2002
Changing distribution of monoaminergic markers in the developing human cerebral cortex with special emphasis on the serotonin transporter
Authors: Verney Catherine , Lebrand Cécile , Gaspar Patricia
Published: August 2002

This article reviews the current knowledge of the early onset of the monoaminergic innervation in the developing cerebral cortex in humans and of changes in the distribution of tyrosine hydroxylase (TH) immunoreactivity in different neuronal populations of the developing telencephalon. The early genesis of the central monoaminergic neurons in mammals has led to postulations of a trophic role of monoamines in brain morphogenesis—especially in the cerebral cortex. The developmental effects of amines can be linked to the transient expression of different molecules linked to dopamine or serotonin neurotransmission. We present novel data on the immunocytochemistry of the vesicular monoamine transporter (VMAT2) and of the high‐affinity serotonin transporter (SERT) in human fetuses. SERT is a marker of the serotoninergic axons and allows visualization of the serotonin afferents of the raphe in the human telencephalon. In addition, during a restricted time period corresponding to 12–14 postovulatory weeks, we found SERT‐immunolabeled fibers in the rostral and caudal limbs of the internal capsule that do not correspond to serotoninergic fibers, but do coincide with the calbindin D28k‐labeled thalamocortical fiber tracts. The present observations are correlated with findings in rodents, in which a transient expression of SERT is visible in the thalamocortical axons during early postnatal life. The function of this transporter has been shown to be important for the fine‐tuning of cortical sensory maps during the critical period of development of these maps. Although the present observation does not allow ascertainment of which neurons transiently express SERT, it lends support to the notion that serotonin and serotonin uptake could have important developmental roles, during the formation of brain connections in humans, as they have in rodents. Anat Rec 267:87–93, 2002. © 2002 Wiley‐Liss, Inc.
Pancreatic lymphatic system in rodents
Authors: Regoli Marì , Bertelli Eugenio , Orazioli Daniela , Fonzi Luciano , Bastianini Arnaldo
Published: August 2002

The lymphatic network of the pancreas has been little investigated and recent studies have provided contrasting data. This research is aimed to supply the morphologic basis to outline the involvement of the lymphatic system in pancreatic pathology. Guinea pigs, rats, and mice were anesthetized with ether and sacrificed with the same anesthetic. Pieces of pancreas were processed for transmission electron microscopy. Semithin sections were observed by light microscopy and, after positive identification by transmission electron microscopy, lymphatics were followed with long series of consecutive sections to define their distribution. Lymphatics were detected in the pancreas of all the animals both in the inter and the intralobular sites. Closer relations with the exocrine parenchyma (ducts and acini) were observed in guinea pig pancreas. Remarkably, interesting relationships between lymphatics and endocrine tissue were observed in all the animals. Overall, however, the lymphatic network of rat pancreas was less develop and preferentially associated with blood vessels. The distribution of the pancreatic lymphatic network appears consistent with an active role in pancreatic pathology. Anat Rec 263:155–160, 2001. © 2001 Wiley‐Liss, Inc.
Injectable gels for tissue engineering
Authors: Gutowska Anna , Jeong Byeongmoon , Jasionowski Marek
Published: August 2002

Recently, tissue engineering approaches using injectable, in situ gel forming systems have been reported. In this review, the gelation processes and several injectable systems that exhibit in situ gel formation at physiological conditions are discussed. Applications of selected injectable systems (alginate, chitosan, hyaluronan, polyethylene oxide/polypropylene oxide) in tissue engineering are also described. Injectable polymer formulation can gel in vivo in response to temperature change (thermal gelation), pH change, ionic cross‐linking, or solvent exchange. Kinetics of gelation is directly affected by its mechanism. Injectable formulations offer specific advantages over preformed scaffolds such as: possibility of a minimally invasive implantation, an ability to fill a desired shape, and easy incorporation of various therapeutic agents. Several factors need to be considered before an injectable gel can be selected as a candidate for tissue engineering applications. Apart from tissue‐specific cell–matrix interactions, the following gel properties need to be considered: gelation kinetics, matrix resorption rate, possible toxicity of degradation products and their elimination routes, and finally possible interference of the gel matrix with histogenesis. Anat Rec 263:342–349, 2001. © 2001 Wiley‐Liss, Inc.
Tissue engineering in the cardiovascular system: Progress toward a tissue engineered heart
Authors: Mann Brenda K. , West Jennifer L.
Published: August 2002

Achieving the lofty goal of developing a tissue engineered heart will likely rely on progress in engineering the various components: blood vessels, heart valves, and cardiac muscle. Advances in tissue engineered vascular grafts have shown the most progress to date. Research in tissue‐engineered vascular grafts has focused on improving scaffold design, including mechanical properties and bioactivity; genetically engineering cells to improve graft performance; and optimizing tissue formation through in vitro mechanical conditioning. Some of these same approaches have been used in developing tissue engineering heart valves and cardiac muscle as well. Continued advances in scaffold technology and a greater understanding of vascular cell biology along with collaboration among engineers, scientists, and physicians will lead to further progress in the field of cardiovascular tissue engineering and ultimately the development of a tissue‐engineered heart. Anat Rec 263:367–371, 2001. © 2001 Wiley‐Liss, Inc.
Peripheral nerve injury: A review and approach to tissue engineered constructs
Authors: Evans Gregory R.D.
Published: August 2002

Eleven thousand Americans each year are affected by paralysis, a devastating injury that possesses associated annual costs of $7 billion (American Paralysis Association, 1997). Currently, there is no effective treatment for damage to the central nervous system (CNS), and acute spinal cord injury has been extraordinarily resistant to treatment. Compared to spinal cord injury, damage to peripheral nerves is considerably more common. In 1995, there were in excess of 50,000 peripheral nerve repair procedures performed. (National Center for Health Statistics based on Classification of Diseases, 9th Revision, Clinical Modification for the following categories: ICD‐9 CM Code: 04.3, 04.5, 04.6, 04.7). These data, however, probably underestimate the number of nerve injuries appreciated, as not all surgical or traumatic lesions can be repaired. Further, intraabodominal procedures may add to the number of neurologic injuries by damage to the autonomic system through tumor resection. For example, studies assessing the outcome of impotency following radical prostatectomy demonstrated 212 of 503 previously potent men (42%) suffered impotency when partial or complete resection of one or both cavernosal nerve(s). This impotency rate decreased to 24% when the nerves were left intact (Quinlan et al., J. Urol. 1991;145:380–383; J. Urol. 1991;145:998–1002). Anat Rec 263:396–404, 2001. © 2001 Wiley‐Liss, Inc.
Effect of the synergist, piperonyl butoxide, on the development of deltamethrin resistance in yellow fever mosquito, Aedes aegypti L. (Diptera: Culicidae)
Authors: Kumar Sarita , Thomas Anita , Sahgal Arunima , Verma Anita , Samuel Thomas , Pillai M.K.K.
Published: August 2002

The larvae and adults of Aedes aegypti were tested for the potential to develop resistance to the synthetic pyrethroid, deltamethrin, alone or a combination of deltamethrin with the synergist, piperonyl butoxide (PBO). Although continuous larval selection for 40 generations resulted in 703‐fold resistance, the resistance ratio in the adults was only 1.3. Similarly, adult selections with deltamethrin showed a resistance ratio of less than four after 40 generations, indicating differential response to deltamethrin selection in the two developmental stages of the insect. When the susceptible larvae were subjected to selection pressure of deltamethrin and PBO in the ratio of 1:5 for 20 generations, the speed of selection for deltamethrin resistance slowed down by 60%. The F24 larvae obtained from the strain selected with deltamethrin alone were further subjected to selection pressure with synergized deltamethrin, which resulted in 89% reversal in deltamethrin resistance in just one generation. However, long‐term selection with the insecticide‐synergist combination returned resistance close to original levels in 15 generations. The data indicate the involvement of cytochrome P450‐dependent detoxification as the primary mechanism of development of resistance to deltamethrin in the larvae. Implications of the results on the management of larval and adult stages of Ae. aegypti are discussed.Arch. Insect Biochem. Physiol. 50:1–8, 2002. © 2002 Wiley‐Liss, Inc.
The Schlumberger array—potential and pitfalls in archaeological prospection
Authors: Aspinall A. , Gaffney C. F.
Published: August 2002

The orientation‐sensitive performance of the Schlumberger array, when used to survey narrow, linear features, has long been recognized in geophysical prospecting for geology. However, in spite of frequent use of the array for archaeological survey, particularly in eastern Europe and the Far East, this directional effect is not apparent in the survey of walls and ditches. In order to examine the array's performance some experiments were carried out in a shallow electrolytic tank using insulating and conducting cylinders. Broadside and longitudinal traverses with systematic expansion of the current electrode spacing facilitated the production of pseudosections. The results confirmed the high selectivity of the Schlumberger response to the orientation of the feature. Broadside traverse of the conductor and longitudinal traverse of the insulator produced very large changes: much smaller signals were recorded for the alternative orientations. A subsequent experiment, however, on a simulated ditch in bedrock revealed no signal. The directional effect for a linear insulator was confirmed in field studies of a simple stone‐walled structure. Implications for survey of low‐contrast linear archaeological features are discussed. Copyright © 2001 John Wiley & Sons, Ltd.
Antiphospholipid antibodies induced in mice by immunization with a cytomegalovirus‐derived peptide cause thrombosis and activation of endothelial cells in vivo
Authors: Gharavi Azzudin E. , Pierangeli Silvia S. , Espinola Ricardo G. , Liu Xiaowei , Colden‐Stanfield Margaret , Harris E. Nigel
Published: August 2002

Objective

To characterize the binding and functional properties of antiphospholipid antibodies (aPL) induced by immunization with a viral peptide and to determine whether aPL are pathogenic in vivo.

Methods

Ten murine monoclonal aPL were generated from spleen cells of PL/J mice immunized with TIFI, a phospholipid‐binding peptide spanning Thr101–Thr120 of ULB0‐HCMVA from human cytomegalovirus (CMV), which shares structural similarity with the phospholipid‐binding site of β2‐glycoprotein I (β2GPI).

Results

The antibodies generated had aPL activity that was inhibited by cardiolipin liposomes, and this inhibition was enhanced in the presence of β2GPI. Some of the antibodies exhibited binding to cultured endothelial cells in vitro, and some had lupus anticoagulant activity. Injection with 2 of the monoclonal aPL in mice resulted in a significant increase in the number of leukocytes adhering to endothelial cells and enhanced thrombus formation in vivo.

Conclusion

These results indicate that aPL induced by immunization with a phospholipid‐binding CMV peptide are pathogenic in vivo. The results also suggest a mechanism (molecular mimicry) by which pathogenic aPL may be generated in patients with antiphospholipid syndrome.
Experience with etanercept in an academic medical center: Are infection rates increased?
Authors: Phillips Kristine , Husni M. Elaine , Karlson Elizabeth W. , Coblyn Jonathan S.
Published: August 2002

Objectives

There is little established information regarding the safety of antitumor necrosis factor therapies used outside the setting of clinical trials. This study evaluated the long‐term safety and tolerability of open‐label use of etanercept when used to treat patients with a variety of systemic rheumatic diseases. Reduction of concomitant corticosteroid and disease‐modifying antirheumatic drug was also assessed.

Methods

Retrospective medical record review of 180 patients who were started on etanercept between December 1998 and April 2000 at an academic medical center.

Results

Most patients (81%) remained on therapy for longer than 6 months, and a significant number (43%) of patients for longer than 12 months. Etanercept was prescribed for rheumatoid arthritis (RA) in 144 patients and for diseases other than RA, including ankylosing spondylitis, psoriatic arthritis, and polymyositis, in 36 patients. Fifty‐six percent of patients taking corticosteroids were able to reduce their dose and 51% of patients were able to taper their methotrexate dosages. Forty‐three patients (26%) discontinued etanercept. Reasons for discontinuing therapy included serious adverse events (2.9%), of which infection was most common. These included a psoas abscess secondary to Mycobacterium avium‐intracellulare, septic wrist, bacteremia, and septic total hip replacement. Two deaths associated with infection were seen.

Conclusions

The majority of the studied patients tolerated etanercept for longer than 6 months. Many of these patients were able to subsequently taper or even discontinue corticosteroid and methotrexate therapy. Serious infections occurred in this patient population. Our results underscore the value of long‐term observation under the conditions of clinical practice beyond controlled clinical trials.
A comparison of the use of text summaries, plain thumbnails, and enhanced thumbnails for Web search tasks
Authors: Woodruff Allison , Rosenholtz Ruth , Morrison Julie B. , Faulring Andrew , Pirolli Peter
Published: August 2002

We introduce a technique for creating novel, enhanced thumbnails of Web pages. These thumbnails combine the advantages of plain thumbnails and text summaries to provide consistent performance on a variety of tasks. We conducted a study in which participants used three different types of summaries (enhanced thumbnails, plain thumbnails, and text summaries) to search Web pages to find several different types of information. Participants took an average of 67, 86, and 95 seconds to find the answer with enhanced thumbnails, plain thumbnails, and text summaries, respectively. As expected, there was a strong effect of question category. For some questions, text summaries outperformed plain thumbnails, while for other questions, plain thumbnails outperformed text summaries. Enhanced thumbnails (which combine the features of text summaries and plain thumbnails) had more consistent performance than either text summaries or plain thumbnails, having for all categories the best performance or performance that was statistically indistinguishable from the best.
Epistemology and the socio‐cognitive perspective in information science
Authors: Hjørland Birger
Published: August 2002

This article presents a socio‐cognitive perspective in relation to information science (IS) and information retrieval (IR). The differences between traditional cognitive views and the socio‐cognitive or domain‐analytic view are outlined. It is claimed that, given elementary skills in computer‐based retrieval, people are basically interacting with representations of subject literatures in IR. The kind of knowledge needed to interact with representations of subject literatures is discussed. It is shown how different approaches or “paradigms” in the represented literature imply different information needs and relevance criteria (which users typically cannot express very well, which is why IS cannot primarily rely on user studies). These principles are exemplified by comparing behaviorism, cognitivism, psychoanalysis, and neuroscience as approaches in psychology. The relevance criteria implicit in each position are outlined, and empirical data are provided to prove the theoretical claims. It is further shown that the most general level of relevance criteria is implied by epistemological theories. The article concludes that the fundamental problems of IS and IR are based in epistemology, which therefore becomes the most important allied field for IS.
Effects of extremely low frequency magnetic field on fertility of adult male and female rats
Authors: Al‐Akhras Moh'd‐Ali , Elbetieha Ahmed , Hasan Mohammed‐Khair , Al‐Omari Imaddin , Darmani Homa , Albiss Borhan
Published: August 2002

To investigate the effects of an extremely low‐frequency (ELF) magnetic field on their fertility, adult male and female Sprague‐Dawley rats were exposed to a 50 Hz sinusoidal magnetic field of approximately 25 μT (rms) for 90 days before they were mated with unexposed counterparts. Exposure to a 50 Hz field reduced male rat fertility. The number of pregnant females was reduced when mated with exposed males, and the number of resorptions increased. The effects of magnetic field on male fertility were shown to be partly reversible, when the same exposed group of males were remated 45 and 90 days after being removed from the fields. Exposure of adult female rats to 50 Hz magnetic fields for 90 days before mating significantly reduced their fertility. The mean numbers of implantations and living fetuses per litter were statistically significantly decreased in the 50 Hz group. These results suggest that low frequency magnetic fields have some adverse effects on fertility of male and female rats. Bioelectromagnetics 22:340–344, 2001. © 2001 Wiley‐Liss, Inc.
Influence of alternating extremely low frequency ELF magnetic field on structure and function of pancreas in rats
Authors: Laitl‐Kobierska Anna , Cieślar Grzegorz , Sieroń Aleksander , Grzybek Henryk
Published: August 2002

The aim of this study was to estimate the influence on ultrastructure and function of endocrine and excretoric part of pancreas in rats of extremely low frequency alternating magnetic fields with parameters used in therapy in humans. The animals from the two experimental groups were exposed to a rectangular magnetic field waveform at a frequency of 10 Hz and induction of 1.8–3.8 mT—(group P) or a sinusoidal magnetic field at a frequency of 40 Hz and induction of 1.3–2.7 mT—(group S), respectively. The control rats were subjected to sham exposure. The cycle of 1, 3, 6, 9, and 14 daily exposure sessions lasting 30 min was made in all groups. Some of rats after finishing the cycle of 14 exposures were left in the same conditions except for the magnetic field for 3 or 10 days. In both groups of rats exposed to magnetic field, a distinct tendency to decrease glucose concentration, compared to control group, was observed during the exposure cycle. Serum glucose became normal after the end of exposure sessions. The concentrations of insulin in both groups of rats exposed to magnetic field were significantly higher, compared to the controls, during the exposure cycle. After the end of exposure cycle the concentration of insulin in group S became normal. In contrast, in group P the concentration of insulin decreased significantly on the last day of exposure, with a subsequent increase in the following days. The activity of α‐lamylase and lipase in the serum of experimental and control rats was not affected. In both groups of exposed rats, reversible changes of ultrastructure of the pancreatic islets, including expansion of the Golgi apparatus, extension of rough endoplasmatic reticulum, mitochondrial swelling, expansion of β‐granules and increase in number of empty vesicles in β cells, occurred during the exposure. In acinar cells of exposed animals, a slight extension of rough endoplasmatic reticulum and mitochondrial swelling as transitory changes were observed. The structural and functional changes in pancreas are probably adaptative ones. Bioelectromagnetics 23:49–58, 2002. © 2002 Wiley‐Liss, Inc.
Is there a code for protein–DNA recognition? Probab(ilistical)ly…
Authors: Benos Panayiotis V. , Lapedes Alan S. , Stormo Gary D.
Published: August 2002

Transcriptional regulation of all genes is initiated by the specific binding of regulatory proteins called transcription factors to specific sites on DNA called promoter regions. Transcription factors employ a variety of mechanisms to recognise their DNA target sites. In the last few decades, attempts have been made to describe these mechanisms by general sets of rules and associated models. We give an overview of these models, starting with a historical review of the somewhat controversial issue of a “recognition code” governing protein–DNA interaction. We then present a probabilistic framework in which advantages and disadvantages of various models can be discussed. Finally, we conclude that simplifying assumptions about additivity of interactions are sufficiently justified in many situations (and can be suitably extended in other situations) to allow a unifying concept of a “probabilistic code” for protein–DNA recognition to be defined. BioEssays 24:466–475, 2002. © 2002 Wiley Periodicals, Inc.
The CtBP family: enigmatic and enzymatic transcriptional co‐repressors
Authors: Turner Jeremy , Crossley Merlin
Published: August 2002

Transcription factors that associate with DNA sequences in promoters and enhancers often recruit co‐regulators that modulate their activity. Many of these co‐regulators have intrinsic enzymatic activity and influence gene expression by modifying chromatin and altering its structure. Recently, a new family of co‐repressors, the C‐terminal binding proteins, has been described. These proteins recognize Pro‐X‐Asp‐Leu‐Ser (PXDLS) motifs in DNA‐binding proteins and function as transcriptional co‐repressors in Drosophila, Xenopus and mammals. The precise mechanisms by which they influence transcription are still under investigation. CtBP proteins dimerize and can contact histone deacetylases; hence they may operate by linking deacetylases to DNA‐bound factors. But it appears that CtBP proteins also have intrinsic enzymatic activity. They have significant homology to D‐isomer‐specific 2‐hydroxy acid dehydrogenases, and remarkably one family member, rat CtBP, has been shown to have a second role, functioning as an acyl transferase in Golgi maintenance. These observations raise the possibility that CtBP proteins might regulate gene expression directly by means of their enzymatic activities, in addition to serving as simple bridging proteins. Supplementary material for this article can be found on the BioEssays homepage at http://www.interscience.wiley.com/jpages/0265‐9247/suppmat/v23_8.684. BioEssays 23:683–690, 2001. © 2001 John Wiley & Sons, Inc.
Physiology and pathophysiology of poly(ADP‐ribosyl)ation *
Authors: Bürkle Alexander
Published: August 2002

One of the immediate eukaryotic cellular responses to DNA breakage is the covalent post‐translational modification of nuclear proteins with poly(ADP‐ribose) from NAD+ as precursor, mostly catalysed by poly(ADP‐ribose) polymerase‐1 (PARP‐1). Recently several other polypeptides have been shown to catalyse poly(ADP‐ribose) formation. Poly(ADP‐ribosyl)ation is involved in a variety of physiological and pathophysiological phenomena. Physiological functions include its participation in DNA‐base excision repair, DNA‐damage signalling, regulation of genomic stability, and regulation of transcription and proteasomal function, supporting the previously observed correlation of cellular poly(ADP‐ribosyl)ation capacity with mammalian life. The pathophysiology effects are mediated through PARP‐1 overactivity, which can cause cell suicide by NAD+ depletion. It is apparent that the latter effect underlies the pathogenesis of a wide range of disease states including type‐1 diabetes, ischaemic infarcts in various organs, and septic or haemorrhagic shock. Therefore pharmacological modulation of poly(ADP‐ribosyl)ation may prove to be an exciting option for various highly prevalent, disabling and even lethal diseases. BioEssays 23:795–806, 2001. © 2001 John Wiley & Sons, Inc.
Parent voices: difficulty in accessing behavioral intervention for autism; working toward solutions
Authors: Maurice Catherine , Mannion Kathy , Letso Suzanne , Perry Lora
Published: August 2002

The history of autism treatment has been dominated by a series of failed treatments, passing fads, and misinformed theories of etiology. With the advances in teaching methods derived from the science of Applied Behavior Analysis however, significant remediation of the disorder is now possible. Yet at present parents or caregivers still face serious challenges in identifying scientifically‐validated treatment models, and in securing competent and well‐trained therapists. Four parents report on these challenges, on the steps they have taken to mitigate these difficulties in their own families, and on the long‐term solutions they are attempting to implement in the wider community. Copyright © 2001 John Wiley & Sons, Ltd.
Analytical applications of flow injection with chemiluminescence detection—a review
Authors: Fletcher Philip , Andrew Kevin N. , Calokerinos Anthony C. , Forbes Stuart , Worsfold Paul J.
Published: August 2002

This paper reviews the literature on analytical applications of flow injection (FI) techniques with chemiluminescence (CL) detection from 1995–1999. The focus is on the application of FI–CL to the quantitative determination of specific analytes in real sample matrices. Therefore, entries have been tabulated under the most appropriate application area, ie pharmaceutical, environmental, foods and beverages and biomedical, as defined by the matrix that has been analysed. Each table lists analytes alphabetically and gives details of the exact sample matrix, the limit of detection (as reported in the original paper) and comments on the CL reaction used. Copyright © 2001 John Wiley & Sons, Ltd.
Maximization of acetic acid production in partial acidogenesis of swine wastewater
Authors: Hwang Seokhwan , Lee Yongse , Yang Keunyoung
Published: August 2002

Swine wastewater was biologically treated to produce short‐chain volatile organic acids (VOAs) in laboratory‐scale continuously stirred tank reactors. The maximum production rates of acetic and butyric acids associated with simultaneous changes in pH and hydraulic retention time (HRT) were investigated, in which the degree of acidification of swine wastewater to the short‐chain VOAs was <25% of influent chemical oxygen demand (COD) concentration. A constant inoculum system was used to minimize the experimental error due to the use of inconsistent inoculum. The inoculum system was operated with synthetic wastewater at 6000 mg soluble chemical oxygen demand per liter (pH 6.0) and 35°C at 0.5 day hydraulic retention time. Response surface methodology was applied successfully to determine the optimum physiological condition for which the maximum rate of acetic acid production occurred, which was pH 5.90 and 0.88 day hydraulic retention time at 35°C. The partial acidification process to manage swine waste should be operated in the optimum condition for acetic acid production because the optimum operating condition for butyric acid production approached the washout point. © 2001 John Wiley & Sons, Inc. Biotechnol Bioeng 75: 521–529, 2001.
Engineering hepatocyte functional fate through growth factor dynamics: The role of cell morphologic priming
Authors: Semler Eric J. , Moghe Prabhas V.
Published: August 2002

We have reported previously that cellular stimulation induced by variable mechanochemical properties of the extracellular microenvironment can significantly alter liver‐specific function in cultured hepatocytes (Semler et al., Biotech Bioeng 69:359–369, 2000). Cell activation via time‐invariant presentation of biochemical growth factors was found to either enhance or repress cellular differentiation of cultured hepatocytes depending on the mechanical properties of the underlying substrate. In this work, we investigated the effects of dynamic growth factor stimulation on the cell growth and differentiation behavior of hepatocytes cultured on either compliant or rigid substrates. Specifically, hepatotrophic growth factors (epidermal and hepatocyte) were either temporally added or withdrawn from hepatocyte cultures on Matrigel that was crosslinked to yield differential degrees of mechanical compliance. We determined that the functional responsiveness of hepatocytes to fluctuations in GF stimulation is substrate specific but only in conditions in which the initial mechanochemical environment induced significant cell morphogenesis. Our studies indicate that in conditions under which hepatocytes adopted a “rounded” phenotype, they exhibited increased levels of differentiated function upon soluble stimulation and markedly decreased function upon the depletion of GF stimulation. In contrast, hepatocytes that assumed a “spread” phenotype exhibited slightly increased function upon the depletion of GF stimulation. By examining the functional responsiveness of hepatocytes of differential morphology to varied fluctuations in GF activation, insights into the ability of cell shape to “prime” hepatocyte behavior in dynamic microenvironments were elucidated. We report on the possibility of uncoupling and, thus, selectively manipulating, the concerted contributions of GF‐induced cellular activation and substrate‐ and GF‐induced cell morphogenesis toward induction of cell function. © 2001 John Wiley & Sons, Inc. Biotechnol Bioeng 75: 510–520, 2001.
Isolation of a recombinant antibody from cell culture supernatant: Continuous annular versus batch and expanded‐bed chromatography
Authors: Giovannini Roberto , Freitag Ruth
Published: August 2002

Annular chromatography represents a crossflow approach to chromatographic separations, that allows the continuous separation of multicomponent mixtures. The potential of the method for continuous bioseparation has been discussed for some time, however, we demonstrate for the first time the processing of a complex feed (cell culture supernatant) taken from an actual (bio)process. Moreover, while previously published applications of annular chromatography concentrated on noninteractive (gel filtration) or nonspecific (ion exchange) chromatography, we show the possibility of continuous annular affinity chromatography. In particular, a commercially available preparative continuous annular chromatography (P‐CAC) system was used to purify a recombinant antibody (human IgG1‐κ) from CHO cell culture supernatants by (pseudo)affinity chromatography on hydroxyapatite (HA) and rProtein A. Methods developed using small (2 mL) batch columns could be directly transferred to the P‐CAC, where they yielded similar results in terms of final product quality. Yields were between 87% and 92% in the case of HA and between 77% and 82% in the case of rProtein A chromatography. DNA removal was nearly quantitative in all cases. Concomitantly, the antibody fraction of the total protein content was raised by one order of magnitude in HA and by a factor of 50 by rProtein A chromatography. In addition, a novel HA material (particle diameter −120 μm) was investigated, which was compatible with expanded‐bed applications. However, the final purity of the antibody thus obtained and also the yields (<70%) were less than satisfactory. © 2001 John Wiley & Sons, Inc. Biotechnol Bioeng 73: 522–529, 2001.
Mechanistic study of microbial control of hydrogen sulfide production in oil reservoirs
Authors: Nemati M. , Jenneman G. E. , Voordouw G.
Published: August 2002

Microbial control of biogenic production of hydrogen sulfide in oil fields was studied in a model system consisting of pure cultures of the nitrate‐reducing, sulfide‐oxidizing bacterium (NR‐SOB) Thiomicrospira sp. strain CVO and the sulfate‐reducing bacterium (SRB) Desulfovibrio sp. strain Lac6, as well as in microbial cultures enriched from produced water of a Canadian oil reservoir. The presence of nitrate at concentrations up to 20 mM had little effect on the rate of sulfate reduction by a pure culture of Lac6. Addition of CVO imposed a strong inhibition effect on production of sulfide. In the absence of added nitrate SRB we were able to overcome this effect after an extended lag phase. Simultaneous addition of CVO and nitrate stopped the production of H2S immediately. The concentration of sulfide decreased to a negligible level due to nitrate‐dependent sulfide oxidation activity of CVO. This was not prevented by raising the concentration of Na‐lactate, the electron donor for sulfate reduction. Similar results were obtained with enrichment cultures. Enrichments of produced water with sulfide and nitrate were dominated by CVO, whereas enrichments with sulfate and Na‐lactate were dominated by SRB. Addition of an NR‐SOB enrichment to an SRB enrichment inhibited the production of sulfide. Subsequent addition of sufficient nitrate caused the sulfide concentration to drop to zero. A similar response was seen in the presence of nitrate alone, although after a pronounced lag time, it was needed for emergence of a sizable CVO population. The results of the present study show that two mechanisms are involved in microbial control of biogenic sulfide production. First, addition of NR‐SOB imposes an inhibition effect, possibly by increasing the environmental redox potential to levels which are inhibitory for SRB. Second, in the presence of sufficient nitrate, NR‐SOB oxidize sulfide, leading to its complete removal from the environment. Successful microbial control of H2S in an oil reservoir is crucially dependent on the simultaneous presence of NR‐SOB (either indigenous population or injected) and nitrate in the environment. © 2001 John Wiley & Sons, Inc. Biotechnol Bioeng 74: 424–434, 2001.
Simultaneous analysis of oxidized and reduced glutathione in cell extracts by capillary zone electrophoresis
Authors: Yang Qing , Krautmacher Carsten , Schilling David , Pittelkow Mark R. , Naylor Stephen
Published: August 2002

Glutathione (GSH) and glutathione disulfide (GSSG) levels in cells constitute a thiol redox system. They can be used as an indicator of oxidative stress of the cell. In this study, a capillary zone electrophoresis (CZE) method is described that enables quantitation of GSH and GSSG from cellular extracts. The CZE buffer used was 20 mM ammonium acetate containing 5% (v/v) acetic acid at pH 3.1 in conjunction with a polybrene coated capillary operated in reverse polarity mode. Effects of different acids used to prepare cell samples were investigated on CZE performance. The acids include meta phosphoric acid (MPA), trichloroacetic acid (TCA), phosphoric acid (PA) and sulfosalicylic acid (SSA) and are used to stabilize GSH and GSSG before performing CZE analysis. The method features a limit of detection of 4 µM and a limit of quantitation of 12 µM for both GSSG and GSH and recoveries of 94% for GSH and 100% for GSSG. Quantitative analysis of GSSG and GSH in HaCaT cell extracts (5% SSA, w/v) was performed with this method and changes in the ratio of GSH to GSSG in N‐ethylmaleimide treated cell sample was observed by comparing with control cell samples. Copyright © 2002 John Wiley & Sons, Ltd.
Integrating environmental and stakeholder management
Authors: Madsen Henning , Ulhøi John P.
Published: August 2002

Regulation has been an important instrument in pushing the business community towards improved environmental performance. However, there has also been increasing pressure from a growing number of stakeholders, including employees, customers, neighbours, NGOs etc. In order to improve corporate relationships with various stakeholders, companies need to be able to identify these stakeholders and assess their influence. The first part of this paper will discuss the relevant theory and introduce a model to analyse and identify the most significant stakeholder groups and their influence on corporate behaviour. Based on a recent survey of Danish companies, the second part of the paper will report on the success of a variety of stakeholders in forcing companies to introduce environment‐related initiatives. The results will then be discussed in light of the theory and other reported results. The paper closes with a discussion of research implications. Copyright © 2001 John Wiley & Sons, Ltd and ERP Environment
Corporate environmental performance evaluation: evidence from the MEPI project
Authors: Tyteca Daniel , Carlens Jérôme , Berkhout Frans , Hertin Julia , Wehrmeyer Walter , Wagner Marcus
Published: August 2002

In recent years research has been rapidly and actively emerging on indicators of environmental performance in industry. Crucial issues are the kind of information that must be taken into account, is available and is relevant, as well as standardization and aggregation of such information. This paper reports on the experience gained in these matters, in the scope of a European Commission funded project involving seven research partners across Europe. Practical applications of the project cover six industrial sectors within six European countries. Exploiting the adopted indicators allows us to draw conclusions about the influence of various factors, including the national context, on environmental performance, and to provide both managers and decision makers with information that is useful for the overall improvement of environmental strategies and environmental regulation. Copyright © 2002 John Wiley & Sons, Ltd. and ERP Environment
Neonaticide: an appropriate application for therapeutic jurisprudence?
Authors: Schwartz Lita Linzer , Isser Natalie K.
Published: August 2002

Might therapeutic jurisprudence, a perspective that attempts to study interaction between the legal and mental health disciplines, be brought to bear effectively with respect to neonaticide, the murder of a newborn infant in the first 24 hours of its life? This is a crime that leads to sentencing that is now rarely therapeutic, rehabilitative, or corrective. An examination of the crime, its motives, and its perpetrators precedes a discussion of ways in which the mental health viewpoint in this matter might be brought to the active attention of the courts in order to promote sentencing that is appropriate to both the crime and the transgressor. Copyright © 2001 John Wiley & Sons, Ltd.
Fractional factorial designs for legal psychology
Authors: Stolle Dennis P. , Robbennolt Jennifer K. , Patry Marc , Penrod Steven D.
Published: August 2002

Researchers considering novel or exploratory psycholegal research are often able to easily generate a sizable list of independent variables (IVs) that might influence a measure of interest. Where the research question is novel and the literature is not developed, however, choosing from among a long list of potential variables those worthy of empirical investigation often presents a formidable task. Many researchers may feel compelled by legal psychology's heavy reliance on full‐factorial designs to narrow the IVs under investigation to two or three in order to avoid an expensive and unwieldy design involving numerous high‐order interactions. This article suggests that fractional factorial designs provide a reasonable alternative to full‐factorial designs in such circumstances because they allow the psycholegal researcher to examine the main effects of a large number of factors while disregarding high‐order interactions. An introduction to the logic of fractional factorial designs is provided and several examples from the social sciences are presented. Copyright © 2002 John Wiley & Sons, Ltd.