bluuebunny/crossref_metadata_2025_split huggingface dataset:
Critical Analysis of Lysozyme Refolding Kinetics
Authors: Buswell A. Mark , Middelberg Anton P. J. 
Published: July 2002

AbstractThe kinetics of lysozyme refolding and aggregation is studied using an existing competing first‐ and third‐order reaction scheme. The existing model overestimates yield at high refolding concentrations (>1 mg/mL), thus limiting its use for reactor design at industrially relevant refolding concentrations. This study demonstrates that a pathway exists for the incorporation of refolded native protein into aggregates. Specifically, native lysozyme labeled with fluorescein isothiocyanate was added to the refolding buffer prior to dilution refolding of denatured and reduced lysozyme. Aggregates collected from these experiments showed significant fluorescence, indicating that labeled lysozyme had been incorporated into the aggregates during refolding. Although the precise pathway of incorporation has not been elucidated, it is clear from this work that the existing model for lysozyme refolding is not globally applicable. In particular, previous work has analytically demonstrated that neglect of a pathway from native to aggregate can result in the design of a grossly suboptimal reactor strategy. This study demonstrates that such a pathway can exist experimentally and emphasizes the need to critically assess refolding kinetic models before their use in reactor design equations.
Enhanced‐Rate Biodegradation of Organophosphate Neurotoxins by Immobilized Nongrowing Bacteria
Authors: Kim Jin‐Woo , Rainina Evguenia I. , Mulbry Walter W. , Engler Cady R. , Wild James R. 
Published: July 2002

AbstractPesticide wastes generated from livestock dipping operations containing the organophosphate (OP) insecticide coumaphos (CP) are well suited for disposal by biodegradation since they are highly concentrated (∼1 g/L), generally contained, and lack additional toxic components. In this study, a significantly enhanced efficiency of degrading CP in cattle dip waste (CDW) is reported using a dense, nongrowing cell population that functions without the addition of nutrients required for growing cell cultures. A recombinant strain of Escherichia coli containing the opd gene for organophosphate hydrolase (OPH), which is capable of active hydrolysis of OP neurotoxins including CP, was cultivated in a rich medium containing all essential nutrients. Cells were harvested and utilized in lab scale experiments in the form of either freely suspended cells or cells immobilized within a macroporous gel matrix, poly(vinyl alcohol) (PVA) cryogel. Significantly higher degradation rates were achieved with either suspended or immobilized OPH+ cells compared to rates with the microbial consortium naturally present in CDW. Of the two nongrowing cell systems, the detoxification rate with immobilized cells was approximately twice that of freely suspended cells, and kinetic studies demonstrated that a higher maximum reaction rate was achieved with the immobilized cell system. A comparative study using both the CDW and pure CP substrates with free cells indicated that the CDW contained one or more factors that reduced the bioavailability of CP. The immobilized cells retained their activity over a 4‐month period of use and storage, demonstrating both sustained catalytic activity and long‐term mechanical stability.
Problems of Translating Heterologous Genes in Expression Systems: The Role of tRNA
Authors: Smith David W. E. 
Published: July 2002

AbstracttRNA can have large effects on the expression and overexpression of heterologous genes in microbial expression systems through reduced translation and errors in amino acid sequences of protein products. Examples are given of large effects on gene expression related to tRNA content and to tRNA base modifications, both of which differ in heterologous expression systems compared to the cells from which the genes originally came. tRNA should be of greater concern in the expression of heterologous genes.
Adsorption Kinetics of Microbial Cells onto a Novel Brush‐Type Polymeric Material Prepared by Radiation‐Induced Graft Polymerization
Authors: Lee William , Furusaki Shintaro , Saito Kyoichi , Sugo Takanobu , Makuuchi Keizo 
Published: July 2002

AbstractA novel brush‐type microbial‐cell‐adsorbing material was prepared by radiation‐induced graft polymerization. A vinyl monomer containing an epoxy group, glycidyl methacrylate (GMA), was first grafted onto a polyethylene‐based fiber before the introduction of a tertiary amino group, i.e., diethylamine (DEA). The grafted‐type DEA fibers prepared were then tested for their microbial‐cell‐adsorbing activity by contacting the fibers with a Staphylococcus aureus suspension. The DEA fibers showed adsorption ability of S. aureus, and the adsorption rate increased with increasing density of the DEA group. On the other hand, DEA was also introduced onto cross‐linked‐type GMA beads and its adsorption rate of S. aureus cells was compared with that of the grafted‐type DEA fibers. The grafted‐type DEA fibers exhibited an adsorption rate constant 1000‐fold greater than that of the cross‐linked‐type DEA beads. Observation by scanning electron microscopy showed that the shape of S. aureus cells adsorbed on the grafted‐type DEA fibers was intact whereas the shape of those adsorbed on the cross‐linked‐type DEA beads was difficult to identify.
Method for Construction of a Simple Laboratory‐Scale Nonwoven Filament Biocatalytic Filter
Authors: Flickinger Michael C. , Mullick Ashim , Ollis David F. 
Published: July 2002

AbstractA method is described for constructing a simple laboratory‐scale nonwoven filament biocatalytic filter (FBF) from multilayer acrylic vinyl acetate copolymer coated thread (yarn) potentially useful for investigation of biotransformations using entrapped enzymes or viable microorganisms. The porous structure of a commercial 128 μm, 279 denier, 100% polyester thread was sealed with a latex coat (precoat), then coated with a latex + sulfanilamide‐azocasein mixture, and finally coated with a latex top coat to generate the multilayer coated thread. The FBF was constructed by drawing the thread across a 4 cm diameter rubber O‐ring in the form of multiple layers and sealing the layers with silicone sealer. The FBF is combatible with a commercially available filter housing containing a flow distrtibutor. A method for characterizing the permeability of the sealant (top) coat of the FBF using azocasein release was also developed.
Catalytic and Structural Properties of Surfactant‐Horseradish Peroxidase Complex in Organic Media
Authors: Kamiya Noriho , Inoue Masahito , Goto Masahiro , Nakamura Nobuhumi , Naruta Yoshinori 
Published: July 2002

AbstractA surfactant‐horseradish peroxidase (HRP) complex that is catalytically active in organic media has been successfully prepared by a method utilizing water‐in‐oil (W/O) emulsions. To optimize conditions for preparation of the HRP complex, the effects of some key parameters in the aqueous phase of W/O emulsions were investigated. The surfactant‐HRP complex prepared with a nonionic surfactant exhibited a high catalytic activity compared to those with a cationic or anionic surfactant in anhydrous benzene. At the preparation step, the pH of the aqueous solution had a prominent effect on the enzymatic activity of the HRP complex in organic media. Several kinds of salts present in the HRP complex could be employed to enhance the catalytic performance in organic media. However, anionic ions present in the preparation process appeared to lower the catalytic activity owing to the complexation with heme iron. UV‐visible absorption spectra of the HRP complex in benzene, which were prepared from a KCN solution (pH 7.0) or an alkaline solution (pH 12), were comparable with those of native HRP in aqueous solution under the same conditions. Resonance Raman spectroscopic studies also revealed that no significant change in the coordination state of the heme iron occurred even after coating the enzyme with surfactant molecules, lyophilization, and solubilization in nonaqueous media.
Human Chymotrypsinogen B Production from Pichia pastoris by Integrated Development of Fermentation and Downstream Processing. Part 2. Protein Recovery
Authors: Thömmes Jörg , Halfar Markus , Gieren Holger , Curvers Simon , Takors Ralf , Brunschier Rainer , Kula Maria‐Regina 
Published: July 2002

AbstractThe purification of human chymotrypsinogen B (hCTRB) after expression and secretion by the yeast Pichia pastoris is described based on two different approaches using integrated initial recovery. Extraction employing aqueous two‐phase systems (ATPS) from poly(ethylene glycol) and sodium sulfate allows direct processing of cell containing yeast suspensions of 50% wet weight. The target protein is obtained partially purified in the top phase while cells and cell debris are partitioned to the bottom phase of the system. hCTRB is further purified by adsorption from the top phase to the cation exchanger SP Sepharose Big Beads and elution in a salt step. The single step isolation of hCTRB is possible by expanded bed adsorption (EBA) using a fluidized cation exchanger (Streamline SP XL). A design strategy is shown taking both target protein binding and stable fluidization of the stationary phase in cell containing suspensions into consideration. For the example of hCTRB isolation from cell containing P. pastoris suspensions, a successful use of this strategy is demonstrated. Both initial recovery strategies deliver a product that can be further purified and formulated by ultrafiltration/diafiltration followed by lyophilization, resulting in a homogeneous product. Scale‐up to 30−90 L of culture suspension was shown for both methods, resulting in a product of similar quality. Comparing both strategies reveals that the two‐step ATPS route is better suited for high cell density cultures, while the single step EBA method is preferred for cultures of moderate cell density. This is due to the fact that application of EBA is restricted to suspensions of 10−12.5% wet weight cell concentration, thus necessitating dilution of the original broth prior to sample application. The data presented show that integrated recovery operations are a valuable alternative to traditional processing for systems that are problematic during initial solid‐liquid separation.
Assisting demented patients with feeding: problems in a ward environment. A review of the literature
Authors: McGillivray Tom , Marland Glenn R. 
Published: July 2002

Assisting demented patients with feeding: problems in a ward environment. A review of the literatureA critical review of the literature on assisting demented patients with feeding difficulties identifies that care at mealtimes is often task‐centred, causing stress in both patients and staff and inadequate patient care. Nurses may even be inducing dependency in this vulnerable patient group. The staff to whom this care is most often delegated do not receive sufficient education or training to enable them to achieve a sufficient degree of empathy with the patient although there is evidence in the literature to suggest that this is a necessary requirement. It is also apparent that nurses use inadequate assessment criteria, perhaps due to the fact that there is an element of commonality in the feeding behaviour of demented patients which nurses feel they have seen many times and are able to deal with. The introduction of primary nursing, increased education of nursing assistants and improved assessment procedures to combat these problems are recommended. The process of change is briefly outlined and in conclusion some areas for future research are stated.
A novel mutation in the hepatocyte nuclear factor‐1α/MODY3 gene in Chinese subjects with early‐onset Type 2 diabetes mellitus in Taiwan
Authors: Jap T. ‐S. , Wu Y. ‐C. , Chiou J. Y. , Kwok C. ‐F. 
Published: July 2002

Summary Aims The goal of this study was to determine the frequency of mutation in hepatic nuclear factor (HNF)‐1α, a gene recently implicated as causing maturity‐onset diabetes of the young (MODY) and to analyse the respective clinical presentations in an ethnically Chinese population. Methods Fifteen unrelated subjects (nine females and six males) aged less than 35 years who had early‐onset diabetes were analysed to test the possibility that mutation of the HNF‐1α gene was responsible for this disorder. Genomic DNA extraction, polymerase chain reaction and DNA sequence analysis were performed accordingly. Results One patient with MODY had a novel missense mutation in exon 3 of the HNF‐1α gene (Y218C) in a region of the protein that corresponds to a predicted DNA binding domain.Conclusions A Y218C mutation in HNF‐1α gene was identified in one family in Taiwan.
New Phytologist in North America
Authors: Ayres Peter 
Published: July 2002

The number of papers submitted to New Phytologist by authors working in North America has increased significantly in recent years. We are now able to offer those authors a better service because, from this month, they will be able to submit their papers direct to our new USA Office – this is being supervised by one of our Editors, Richard Norby, and is located at Oak Ridge, Tennessee: New Phytologist USA Office, Oak Ridge National Laboratory, Bldg 1059, PO Box 2008, Oak Ridge, TN 37831‐6422, USA. Tel: +1 423 576 5261. Fax: +1 423 576 9939. E‐mail: newphytol@ornl.gov.
The new ARIA guidelines: putting science into practice
Authors: Bousquet J. 
Published: July 2002

SummaryAllergic rhinitis is a worldwide health problem, which can greatly interfere with the quality of life of affected patients. Allergic conjunctivitis and asthma often accompany rhinitis. Unlike asthma, allergic rhinitis does not affect the physical activities of sufferers. However, rhinitis does impair the mental and social activities as much as any associated asthma. In view of the considerable adverse impact of allergic rhinitis on the life of affected individuals, treatment must be optimal. The efficacy of the range of available medications has been evaluated on the basis of scientific evidence, especially that derived from randomized controlled trials. From the collated information, guidelines have been formulated – the Allergic Rhinitis and its Impact on Asthma (ARIA) guidelines. Drugs with confirmed efficacy (antihistamines, topical cromones and steroids) have been used to treat patients with intermittent or persistent allergic rhinitis. Patients should be treated with a stepwise approach, using increasingly powerful therapy for symptoms of increasing severity. It is necessary to emphasize that patients must be treated as an entity, so that not only the allergic rhinitis but also any accompanying conjunctivitis or asthma are treated.
A Long‐term Open‐Label Study of Oral Almotriptan 12.5 mg for the Treatment of Acute Migraine
Authors: Mathew Ninan T. , For The Oral Almotriptan Study Group  
Published: July 2002

Objective.—Evaluate the long‐term tolerability of almotriptan 12.5 mg for the treatment of acute migraine attacks occurring over a 6‐month period.Background.—Almotriptan is a second‐generation 5‐HT1B/1D agonist that exhibits vascular selectivity for meningeal arteries and has demonstrated efficacy for the treatment of acute migraine in short‐term controlled trials.Methods.—This was a 6‐month open‐label study. Adults (18 years of age or older) were required to have a diagnosis of acute migraine with or without aura (according to the diagnostic criteria of the International Headache Society), a history of at least 1 year of moderate‐to‐severe migraine pain with at least two and a maximum of six migraines per month, and at least 24 hours of freedom from head pain between attacks. Patients were instructed to take a single 12.5‐mg dose of almotriptan at the onset of a migraine attack. If migraine pain did not disappear in 2 hours, escape medication could be taken; if relapse occurred in less than 24 hours, a second 12.5‐mg dose could be taken. Tolerability was assessed from the nature and incidence of all adverse events, and efficacy was assessed according to the end point of pain relief 2 hours following almotriptan administration.Results.—Of 585 patients treated, 582 were included in the intent‐to‐treat population. The most frequent drug‐related adverse events were nausea (3.1%) and dizziness (2.4%). No serious drug‐related adverse events were reported, and no deaths occurred. Adverse events led to discontinuation of treatment in 36 patients (6.2%). Drug‐related chest pain was reported in 9 patients (1.5%). Seventy‐six percent of patients achieved pain relief at 2 hours for all attacks treated, and 49% were pain‐free at 2 hours. After a second dose of almotriptan 12.5 mg, pain relief was achieved in 87% of attacks, and 59% were pain‐free. Pain relief and pain‐free rates were higher among those with moderate baseline pain.Conclusions.—When taken at attack onset, almotriptan 12.5 mg is well tolerated, safe, and effective for the long‐term treatment of acute migraine.
Determination of cytokine mRNA-expression in term human placenta of patients with gestational hypertension, intrauterine growth retardation and gestational diabetes mellitus using polymerase chain reaction
Authors: Wilhelm S. , Müller H. , Briese V. , Bittorf T. , Brock J. , Heinig J. 
Published: July 2002

Summary
Objective: Our objective was to test the hypothesis, that pregnancy-related diseases are going along with changes in cytokine mRNA-expression at the placental site, either as a part of a pathological process or in connection with regulatory mechanisms induced by disturbances at the feto-maternal interface resulting from previous pathological changes – in the sense of counterregulation. Material and methods: The cytokines chosen for this investigation are known to 1.) be expressed in the human placental tissue, 2.) to be involved in immunological processes and 3.) the regulation of growth and differentiation processes of different cell types of the placenta or decidua, 4.) to play a role in the angiogenesis at the feto-placental interface and 5.) to be involved in pathological processes in other human diseases. 32 samples derived from term human placentas were examined for messenger RNA levels of interleukin 1 alpha (Il-1α), tumor necrosis factor-alpha (TNF-α), platelet derived growth factor-A chain (PDGF-A), platelet derived growth factor-B chain (PDGF-B), and platelet derived growth factor receptor (PDGF-R) using a semiquantitative reverse transcriptase (RT) polymerase chain reaction (PCR) protocol. To calibrate samples in our procedure, β-actin mRNA (messanger ribonucleid acid) known as a “house keeping” gene was proven to be constantly expressed. The sample-groups consisted of normal pregnancies (n = 8), gestational hypertension (GH, n = 7), intrauterine growth retardation (IUGR, n = 6), gestational diabetes mellitus (GDM, n = 5), and gemini (n = 3 × 2). Results: Throughout the 32 samples, a significant correlation between PDGF-A and PDGF-R expression, PDGF-A and TNF-alpha expression was stated (p = 0.007). Compared with the pattern of expression in normal placentas, placentas of growth retarded pregnancies had higher Il-1α mRNA (p = 0.016), PDGF-A (p = 0.029) and PDGF-B (p = 0.001) levels. The samples of the gestational hypertension group and placentas of patients with gestational diabetes displayed a significantly stronger PDGF-R mRNA signal (p = 0.0029 and p = 0.008). Conclusions: Though these marked differences in cytokine mRNA levels between clinical groups were statistically proven, clear correlation of these differences with clinical data was not found.
Heteroepitaxial wurtzite and zinc-blende structure GaN grown by reactive-ion molecular-beam epitaxy: Growth kinetics, microstructure, and properties
Authors: Powell R. C. , Lee N.-E. , Kim Y.-W. , Greene J. E. 
Published: July 2002

Reactive-ion molecular-beam epitaxy has been used to grow epitaxial hexagonal-structure α-GaN on Al2O3(0001) and Al2O3(011̄2) substrates and metastable zinc-blende-structure β-GaN on MgO(001) under the following conditions: growth temperature Ts=450–800 °C; incident N+2/Ga flux ratio JN+2/JGa=1–5; and N+2 kinetic energy EN+2=35–90 eV. The surface structure of the α-GaN films was (1×1), with an ≊3% contraction in the in-plane lattice constant for films grown on Al2O3(0001), while the β-GaN films exhibited a 90°-rotated two-domain (4×1) reconstruction. Using a combination of in situ reflection high-energy electron diffraction, double-crystal x-ray diffraction, and cross-sectional transmission electron microscopy, the film/substrate epitaxial relationships were determined to be: (0001)GaN∥ (0001)Al2O3 with [21̄1̄0]GaN∥[11̄00]Al2O3 and [11̄00]GaN∥[12̄10]Al2O3, (21̄1̄0)GaN∥(011̄2)Al2O3 with [0001]GaN∥[01̄11]Al2O3 and [01̄10]GaN∥[21̄1̄0]Al2O3, and (001)GaN∥(001)MgO with [001]GaN∥[001]MgO.
Films with the lowest extended defect number densities (nd≂1010 cm−2 threading dislocations with Burgers vector a0/3&lt;112̄0≳) and the smallest x-ray-diffraction ω rocking curve widths (5 min) were obtained using Al2O3(0001) substrates, Ts≥650 °C, JN+2/JGa≥3.5, and EN+2=35 eV. Higher N+2 acceleration energies during deposition resulted in increased residual defect densities. In addition, EN+2 and JN+2/JGa were found to have a strong effect on film growth kinetics through a competition between collisionally induced dissociative chemisorption of N2 and stimulated desorption of Ga as described by a simple kinetic growth model. The room-temperature resistivity of as-deposited GaN films grown at Ts=600–700 °C with EN+2=35 eV increased by seven orders of magnitude, from 10−1 to 106 Ω cm, with an increase in JN+2/JGa from 1.7 to 5.0. Hall measurements on the more conductive samples yielded typical electron carrier concentrations of 2×1018 cm−3 with mobilities of 30–40 cm2 V−1 s−1. The room-temperature optical band gaps of α-GaN and β-GaN were 3.41 and 3.21 eV, respectively.
Uncertain identities and health‐risking behaviour: the case of young people and smoking in late modernity
Authors: Denscombe Martyn 
Published: July 2002

ABSTRACTThis paper argues that ‘uncertain identities’ are a distinct contributing factor to the residual and intractable level of smoking among young people. Further, it argues that the significance of this factor is increased by the specific social/historical context of late modernity. Findings from research with 15 to 16 year olds in the East Midlands of England are used to explore the role that smoking is perceived to play in constructing a self identity. A voluntaristic perspective is adopted on the use of tobacco, reflecting both the focus on young people's motivation to smoke and the tendency for many young people to perceive smoking as a matter of personal choice. Smoking was found to have a symbolic significance not only in terms of the presentation of self to others but also in terms of the reflexive construction of the self by those involved. The paper analyses the role of smoking in relation to self‐image, self‐empowerment and self‐affirmation and it is concluded that for many young people smoking has certain benefits in terms of coping with uncertain identities.