bluuebunny/crossref_metadata_2025 huggingface dataset:
Resorbable defect analog PLGA scaffolds using CO2 as solvent: Structural characterization
Authors: Maspero F. A. , Ruffieux K. , Müller B. , Wintermantel E.
Published: September 2002

After tooth extraction, the immediate wound treatment by implanting an exact copy of the root could prevent alveolar bone atrophy. The implant should have an interconnected porosity in order to promote tissue in‐growth. This communication reports a novel method to realize such net‐shaped porous scaffolds fabricated within a few minutes. Porosity and micro‐architecture are evaluated by Hg‐porosimetry and by image analysis of electron and light microscopy as well as by computed micro‐tomography. The total porosity of the scaffold corresponds to (63 ± 3)%, mainly related to open interconnected porosity. Micro‐tomography, as a noninvasive 3D method, is best suited to uncover pores of about 100 μm, a diameter especially important for tissue in‐growth. The differentiation between open and closed porosity, however, depends on the method chosen. This effect is attributed to the spherical pores with an orifice only detected in the 3D analysis. Consequently, the closed porosity is overestimated by 8% evaluating 2D images. Finally, the mean pore diameter is found to be 106 and 100 μm for 2D and 3D analysis, respectively. Although the porosity of the scaffold needs to be further optimized for clinical applications, the procedure proposed is a promising route in manufacturing open porous implants without the use of any organic solvent. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 62: 89–98, 2002
Synthesis of functionally graded MgCO3 apatite accelerating osteoblast adhesion
Authors: Yamasaki Y. , Yoshida Y. , Okazaki M. , Shimazu A. , Uchida T. , Kubo T. , Akagawa Y. , Hamada Y. , Takahashi J. , Matsuura N.
Published: September 2002

As a means of improving the biological properties of materials for use as bone substitutes, functionally graded carbonate apatite containing Mg, FGMgCO3Ap, was synthesized at 60°C and pH 7.4 using a gradient magnesium supply system. X‐ray diffraction analysis of FGMgCO3Ap showed a poorly crystallized apatitic pattern, similar to that of human bone. ESCA analysis clearly showed the negative gradient distribution in Mg1s intensity (atomic concentration) of magnesium from the crystal surface toward the inner core. When the FGMgCO3Ap crystals were mixed with collagen, the resulting FGMgCO3Ap‐collagen composite, irradiated with UV light for 4 h, retained their features in the saline solution. After washing away the nonadhesive cells, a cell adhesion assay showed that the optical density of the FGMgCO3Ap‐collagen composite was higher than that of the CO3Ap‐collagen composite. SEM observation showed that the osteoblast‐like cells adhered well to the surface of the FGMgCO3Ap‐collagen composite. Staining with hematoxylin‐eosin and alizarin red confirmed the existence of a great many more cells and a thicker extracellular matrix layer on the FGMgCO3Ap‐collagen composite than on the CO3Ap‐collagen composite. This result demonstrated the acceleration effect of magnesium ions on osteoblast adhesion on the FGMgCO3Ap‐collagen composite. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 62: 99–105, 2002
Interactions between MC3T3‐E1 cells and textured Ti6Al4V surfaces
Authors: Soboyejo W. O. , Nemetski B. , Allameh S. , Marcantonio N. , Mercer C. , Ricci J.
Published: September 2002

This paper presents the results of an experimental study of the interactions between MC3T3‐E1 (mouse calvarian) cells and textured Ti6Al4V surfaces, including surfaces produced by laser microgrooving; blasting with alumina particles; and polishing. The multiscale interactions between MC3T3‐E1 cells and these textured surfaces are studied using a combination of optical scanning transmission electron microscopy and atomic force microscopy. The potential cytotoxic effects of microchemistry on cell–surface interactions also are considered in studies of cell spreading and orientation over 9‐day periods. These studies show that cells on microgrooved Ti6Al4V geometries that are 8 or 12 μm deep undergo contact guidance and limited cell spreading. Similar contact guidance is observed on the surfaces of diamond‐polished surfaces on which nanoscale grooves are formed due to the scratching that occurs during polishing. In contrast, random cell orientations are observed on alumina‐blasted Ti6Al4V surfaces. The possible effects of surface topography are discussed for scar‐tissue formation and improved cell–surface integration. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 62: 56–72, 2002
Analyses of rampant corrosion in stainless‐steel retainers of orthodontic patients
Authors: Kusy R. P. , Ambrose W. W. , LaVanier L. A. , Newman J. G. , Whitley J. Q.
Published: September 2002

Retainers were collected from private, university, and dental labs. After viewing these corroded and control appliances using scanning electron microscopy, corroded maxillary and mandibular retainers were selected along with a control stainless‐steel retainer for in‐depth chemical analysis. Using electron spectroscopy for chemical analysis, monochromated Al x‐rays were rastered over areas 1.5 × 0.3 mm. After survey spectra were acquired, high‐resolution multiplex scans were obtained and binding energy shifts were noted. Using Auger electron spectroscopy, a spot size of approximately 30 nm was analyzed. Photos, survey scans, and depth profiles were acquired using a 3.5kV Ar+ ion beam that was calibrated using a SiO2 standard. Via electron spectroscopy for chemical analysis, the brown stains contained Fe and Cr decomposition products in which three carbon species were present. Proteinaceous N was found as amines or amides. No Ni was present because it had solubilized. The Cr:Fe ratio indicated severe Cr depletion in the stained regions (0.2) versus the control regions (1.3). The stained regions appeared mottled, having both dark and light areas. Via AES, the dark versus light areas of the stained regions indicated that there was an absence versus a presence of both Cr and Ni. In the dark areas corrosion penetrated 700 nm; in the light areas the depth equaled 30 nm. By comparison, the passivated layer of the control retainer was 10‐nm thick. After sputtering away the affected areas, all specimens had similar spectra as the control regions. The bacterial environment created the mottled appearance and induced electrochemical potential differences so that, upon reducing the passivated layer, an otherwise corrosion‐resistant alloy became susceptible to rampant corrosion. An integrated biological‐biomaterial model is presented for the classic case of an orthodontic acrylic‐based stainless steel retainer subject to crevice corrosion. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 62: 106–118, 2002
Hyaluronate‐heparin conjugate gels for the delivery of basic fibroblast growth factor (FGF‐2)
Authors: Liu Lin‐Shu , Ng Chee‐Keng , Thompson Andrea Y. , Poser James W. , Spiro Robert C.
Published: September 2002

The stability and activity of recombinant growth factors administered locally for the repair of damaged tissue can be directly influenced by the physical structure and chemical composition of the delivery matrix. This study describes a novel basic fibroblast growth factor‐2 (FGF‐2) delivery system synthesized by the conjugation of a structure‐stabilizing polymer, hyaluronate (HA), with a sulfated glycosaminoglycan, heparin (HP), that has inherent specific binding sites for members of the FGF family. The biopolymers were formed via stable amine or labile imine bonds by coupling amine‐modified HA with oxidized heparin. The addition of recombinant human FGF‐2 resulted in the rapid binding of FGF‐2 to the heparin segment of the hyaluronate‐heparin (HAHP) conjugate. The FGF‐2 was released in vitro from the imine‐bonded (HAHPi) gels in the form of FGF‐2‐heparin complexes through the hydrolysis of the imine bonds. In contrast, the release of growth factor from the more stable amine‐bonded (HAHPa) gels required treatment with free heparin or enzymatic digestion of the hyaluronate segment. Functional analysis of the released FGF‐2 showed that the HAHP conjugate gels increased both the stability and activity of the growth factor. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 62: 128–135, 2002
A reporter‐cell assay for the detection of BMP‐2 immobilized on porous and nonporous materials
Authors: Wiemann M. , Jennissen H. P. , Rumpf H. , Winkler L. , Chatzinikolaidou M. , Schmitz I. , Bingmann D.
Published: September 2002

Human recombinant bone morphogenetic protein‐2 (rhBMP‐2) immobilized on the surface of metal implants can facilitate osseointegration. Here, we describe a cell reporter assay useful for quantifying small amounts of immobilized rhBMP‐2 on various materials. The peptide was dotted and heat‐fixed on titanium, 316L stainless steel, nitrocellulose, or glass, and its distribution was monitored by in situ biotinylation followed by detection with the avidin–biotin method. Bioactivity of rhBMP‐2 was demonstrated by means of a confluent layer of osteoblastic MC3T3‐E1 cells that evenly covered rhBMP‐2–free and rhBMP‐2–loaded surface areas, as shown with epifluorescence microscopy of calcein acetoxymethyl (AM)‐loaded cells. Expression of osteocalcin, fibronectin, actin, and vimentin increased where cells were located on rhBMP‐2 dotted areas, but the signal:noise ratio was too low to bioassay the peptide. However, local pronounced expression of alkaline phosphatase was used to quantify BMP‐2 in the range of 5–80 ng/dot by means of a cytochemical color reaction for alkaline phosphatase and image analysis of resulting dots. The lower detection limit was in the order nitrocellulose > glass > titanium > 316L steel. We conclude that the cell reporter assay is useful to assess biological activity of rhBMP‐2 even after immobilization on three‐dimensional implant materials. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 62: 119–127, 2002
Study of a hydraulic dicalcium phosphate dihydrate/calcium oxide‐based cement for dental applications
Authors: El Briak Hasna , Durand Denis , Nurit Josiane , Munier Sylvie , Pauvert Bernard , Boudeville Phillipe
Published: September 2002

By mixing CaHPO4 · 2H2O (DCPD) and CaO with water or sodium phosphate buffers as liquid phase, a calcium phosphate cement was obtained. Its physical and mechanical properties, such as compressive strength, initial and final setting times, cohesion time, dough time, swelling time, dimensional and thermal behavior, and injectability were investigated by varying different parameters such as liquid to powder (L/P) ratio (0.35–0.7 ml g−1), molar calcium to phosphate (Ca/P) ratio (1.67–2.5) and the pH (4, 7, and 9) and the concentration (0–1 M) of the sodium phosphate buffer. The best results were obtained with the pH 7 sodium phosphate buffer at the concentration of 0.75 M. With this liquid phase, physical and mechanical properties depended on the Ca/P and L/P ratios, varying from 3 to 11 MPa (compressive strength), 6 to 10 min (initial setting time), 11 to 15 min (final setting time), 15 to 30 min (swelling time), 7 to 20 min (time of 100% injectability). The dough or working time was over 16 min. This cement expanded during its setting (1.2–5 % according to Ca/P and L/P ratios); this would allow a tight filling. Given the mechanical and rheological properties of this new DCPD/CaO‐based cement, its use as root canal sealing material can be considered as classical calcium hydroxide or ZnO/eugenol‐based pastes, without or with a gutta‐percha point. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res (Appl Biomater) 63: 447–453, 2002
Osteogenic stem cells and orthopedic engineering: Summary and update
Authors: Triffitt James T.
Published: September 2002

The use of osteogenic stem cells or osteoprogenitors to reconstruct skeletal tissues is a popular area of research investigation with high potential for successful use of tissue‐engineering principles in orthopedics. Recent studies demonstrate the migration of marrow‐derived stem cells to skeletal sites and the proliferation and differentiation at local tissue sites and support possibilities for assessing the successful uses of human osteoprogenitors in the treatment of bone deficiency diseases. In addition, the development of gene therapy procedures in these and other conditions is now considered an achievable goal with the use of these primitive marrow cells. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res (Appl Biomater) 63: 384–389, 2002
In situ study of partially crystallized Bioglass® and hydroxylapatite in vitro bioactivity using atomic force microscopy
Authors: Leonor I. B. , Ito A. , Onuma K. , Kanzaki N. , Zhong Z. P. , Greenspan D. , Reis R. L.
Published: September 2002

The present work investigates, in situ, the in vitro bioactivity of partially crystallized 45S5 Bioglass® (BG) as a function of immersion time in a simulated body fluid (SBF) using atomic force microscopy (AFM). The results obtained for the crystallized BG® were compared to those of hydroxyapatite c‐ and a‐faces. The calcium phosphate layer grows on the crystallized 45S5 B® by multiple two‐dimensional nucleation and fusion of these two‐dimensional islands, which is essentially the same mode as for the hydroxyapatite c‐face. The surface of the crystallized 45S5 BG® was almost fully covered with a dense and compact calcium phosphate layer after 24 h. The calcium phosphate formation on the crystallized BG® arises from a low surface energy of the surface layer and/or an effect of the layer to lower the resistance when the growth units of calcium phosphate incorporate into the growing island. These results indicate that the crystallized 45S5 BG® is suitable to be used as a filler for polymeric matrix bioactive composites, as it maintains a high bioactivity associated with a stiffer behavior (as compared to standard BG®). © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 62: 82–88, 2002
Parallelization of multireference perturbation calculations with GAMESS
Authors: Umeda Hiroaki , Koseki Shiro , Nagashima Umpei , Schmidt Michael W.
Published: September 2002

The quasi‐degenerate multireference second‐order perturbation theory (MRMP2) routines in the GAMESS suite of program codes have been parallelized using a distributed data interface (DDI). Two typical kinds of molecules were chosen for examination of parallelization speedup using one to eight PCs gathered as a cluster and connected by Fast Ethernet. The first example, in which total energies of several low‐lying electronic states have been obtained for niobium monohydride, give parallelization speedup of 7.15 when eight PCs were used as a cluster. The second example is the ground‐state total energy for a medium sized molecule, 4a,4b,8a,9a‐tetrahydro‐pyridino[1′,2′‐4,3]imidazo‐lidino[1,5‐a]pyridine. When distributed memory is employed, the parallelization speedup improves to 6.84 for the MRMP2 calculations when an eight‐PC cluster is used. These results demonstrate that our efforts to achieve the parallelization of MRMP2 routines have been successful. © 2001 John Wiley & Sons, Inc. J Comput Chem 22: 1243–1251, 2001
Application of an improved biuret method to the determination of total protein in urine and cerebrospinal fluid without concentration step by use of Hitachi 7170 auto‐analyzer
Authors: Guobing Xu , Lili Jiao , Lihua Zhu , Tiean Xia
Published: September 2002

A biuret automated colorimetric assay for total protein in urine and cerebrospinal fluids was established. The procedures were as follows. Acidify all urine sample before analysis. Add precipitant Na2WO4 to urine samples. After 10 min, centrifuge, decant the supernatant fluid, drain the inverted tubes on absorbent tissue, dissolve the precipitation with 0.1 mol/L NaOH, and finally adapt the reconstituted urine to the Hitachi 7170 analyzer. A cell‐free cerebrospinal fluid sample produced by centrifugation can be inserted in an auto‐analyzer for protein measurement directly. The program: mix 35 μl sample (CSF or reconstituted urine) and standard with 0.2 mol/L NaOH; incurable at 37°C for 5 min, and real A1. Add concentrated biuret reagent, and 10 min later measure absorbance A2 at 546 nm vs. reagent blank. Secondary wavelength was 700 nm. The test results were calculated against a one‐point standard. This biuret colorimetric method was relatively simple, fast, and accurate for the determination of protein in urine and cerebrospinal fluid, with a wide linearity extending from 0.125 g/L up to 6 g/L, had a good correlation with Benzethonium chloride turbidimetry technique, and was a practical routine method. J. Clin. Lab. Anal. 15:161–164, 2001. © 2001 Wiley‐Liss, Inc.
Sensitive and rapid immunoassays for Salmonella enteritidis
Authors: Liu J.‐L. , Benson C.E. , Munro D.S. , Wolf B.
Published: September 2002

In order to develop more sensitive, specific, and rapid immunoassays to detect Salmonella enteritidis in food supplies, we have applied various approaches by using several different antibody preparations. Utilizing ELISA in both a plate and immunodot assay, we employed (i) a polycolonal rabbit antiserum to a boiled suspension of the organism; (ii) a monoclonal antibody to the cell surface of the bacterium; and (iii) mouse antisera to two oligosaccharides each containing the rare sugar tyvelose, and exhibited by S. enteritidis, a member of the group D salmonellae. We showed that the polyclonal antiserum and monoclonal antibody IG‐10 to the cell surface could specifically detect from 102 to 103 organisms in a 10‐μl sample in the plate and immunodot assay. Both assays are read in 4–5 hr. Further, in the mice immunized to the trisaccharide, (α‐D‐galactose‐α‐tyvelose‐α‐D‐mannose), as well as those mice immunized to the tetrasaccharide, (α‐D‐galactose‐α‐tyvelose‐α‐D‐mannose‐α‐L‐rhamnose), specificity to tyvelose was determined by inhibition studies. The inhibitors of the antisera to the trisaccharide included the single sugar tyvelose conjugated to bovine serum albumin (BSA), a tetrasaccharide in which tyvelose is excluded, but contains α‐D‐galactose, α‐ascarose, α‐D‐mannose, and α‐L‐rhamnose (conjugated to BSA), and others. The inhibition studies suggest that the mouse antisera are specific for tyvelose and also contain antibodies for mannose and rhamnose. The antibodies that have been made to the unique sugar tyvelose should improve the specificity in assays for S. enteritidis. J. Clin. Lab. Anal. 15:165–170, 2001. © 2001 Wiley‐Liss, Inc.
Asian multicenter trials on urinary type IV collagen in patients with diabetic nephropathy
Authors: Tomino Yasuhiko , Suzuki Shigenobu , Azushima Chieko , Shou Ichiyu , Iijima Toshihiko , Yagame Mitsunori , Wang Li Ning , Chen Hung‐Chun , Lai Kar‐Neng , Tan Si Yen , Kim Myung Jae
Published: September 2002

To investigate the changes of renal type IV collagen turnover in diabetic nephropathy, urinary type IV collagen was measured by a highly sensitive one‐step sandwich enzyme immunoassay (EIA). Urinary samples were obtained from 698 diabetic patients and 191 healthy adults. Among the patients, 264 had urinary albumin levels of less than 29 mg/g·creatine (Cr) (Stage I: normoalbuminuric stage), 169 had microalbuminuria from 30 to 299 mg/g·Cr (Stage II: microalbuminuric stage), 84 patients had macroalbuminuria of more than 300 mg/g·Cr and serum Cr of less than 1.1 mg/dl (Stage IIIA: macroalbuminuric stage without renal dysfunction), 97 had macroalbuminuria of more than 300 mg/g·Cr and serum Cr of more than 1.2 mg/dl (Stage IIIB: macroalbuminuric stage with renal dysfunction), and 84 had renal failure (Stage IV). The levels of urinary type IV collagen in Stages II, IIIA, IIIB, and IV were significantly higher than those in Stage I (P < 0.0001). The level of urinary type IV collagen in Stage I (5.00 ± 0.23 μg/g·Cr; mean ± SE) was also higher than that in normal adults (3.44 ± 0.11 μg/g·Cr; mean ± SE). These levels increased gradually due to progression of the clinical stage of diabetic nephropathy. It appears that the levels of urinary type IV collagen can be a useful marker for detecting renal injuries in diabetes according to our Asian multicenter trials. J. Clin. Lab. Anal. 15:188–192, 2001. © 2001 Wiley‐Liss, Inc.
Characterization of serum and urinary chromogranin A by size exclusion chromatography: Impact on calibrator selection and urinary assay
Authors: Tsao K.‐C. , Liu G.H. , Chang P.‐Y. , Lin C.‐N. , Wu T.‐L. , Sun C.‐F. , Wu J.T.
Published: September 2002

Serum chromogranin A (CgA) is a useful marker for neuroendocrine tumors and is detectable in carcinomas at advanced stages. Elevated serum CgA is also an indicator of poor prognosis in prostate cancer and is useful for predicting the failure of hormonal therapy for prostate cancer patients. We found that CgA molecules with three different sizes could be detected in normal human serum. However, only the largest CgA molecule appears in patients with liver disease. Serum taken from cancer patients is composed predominantly of the middle‐sized molecule, whereas the smallest CgA molecule was elevated in serum drawn from renal patients. Moreover, only the smallest CgA molecule was found in urine. We believe that the largest CgA molecule is metabolized by the liver, whereas the smallest CgA molecule is removed from the blood circulation via the kidney. Because the medium‐sized CgA is the dominant molecule in both the cell medium of the tumor cell line SK‐N‐AS and sera from patients with malignant diseases, CgA from the cell medium was selected as the calibrator for the CgA ELISA assay. Our findings also suggest that it would not be possible to measure the urinary CgA to reflect the serum CgA concentration in order to detect pheochromocytoma among patients with hypertension. J. Clin. Lab. Anal. 15:193–198, 2001. © 2001 Wiley‐Liss, Inc.
Research on posttraumatic stress disorder: Epidemiology, pathophysiology, and assessment
Authors: Schnurr Paula P. , Friedman Matthew J. , Bernardy Nancy C.
Published: September 2002

Posttraumatic stress disorder (PTSD) is a highly prevalent disorder in both clinical and community populations. This article reviews current knowledge about PTSD in order to assist clinicians in the diagnosis and treatment of reactions to traumatic life events. First, research findings are presented, followed by guidelines for the assessment of trauma and PTSD. Topics discussed include epidemiology, course, and comorbidity, as well as information processing and psychobiology. The review is limited to information about PTSD in adults, although some of the material may generalize to child and adolescent populations. © 2002 Wiley Periodicals, Inc. J Clin Psychol/In Session 58: 877–889, 2002.
On mental events, disciplinary boundaries, and reductionism: A reply to Plaud
Authors: Ilardi Stephen S. , Feldman David
Published: September 2002

Plaud's (2001) radical behavioral manifesto suggests that a psychological science based exclusively upon the study of environment‐behavior functional contingencies would yield a discipline unencumbered by mentalism, vaguely delineated disciplinary boundaries, or inappropriate reductionism. In reply, we note that: (a) mental events—e.g., thoughts and feelings—are increasingly accessible to objective investigation, and provide an observable proximal causal mechanism for the environmental selection of behavior; (b) the call for pristine disciplinary boundaries is anachronistic, inasmuch as progress in the natural sciences has engendered disciplinary boundaries that are increasingly porous; (c) cognitive neuroscience facilitates a comprehensive understanding of complex human behavior by mapping out the relationship between such behavior and underlying brain events, thereby engaging in an appropriate form of reductionism (constitutive reductionism) that has become a hallmark of the natural sciences; and (d) ironically, it is radical behaviorism, in its disavowal of the informational level of complexity instantiated in brain events, that engages in inappropriate eliminative reductionism (i.e., reducing neural information to “nothing but” its underlying bring states). © 2001 John Wiley & Sons, Inc. J Clin Psychol 57: 1103–1107, 2001.
Paradigms, promises, and the potential of clinical psychology
Authors: Strauman Timothy J.
Published: September 2002

Both Plaud's and Ilardi and Feldman's articles call for clinical psychology to redefine itself according to a particular paradigm or “unifying framework.” This commentary focuses on the nature of clinical psychology as an applied discipline, whether clinical psychology in fact has an urgent need for a unifying framework, and whether radical behaviorism or cognitive neuroscience could provide such a framework. It is concluded that, as an applied field that draws both theory and method from a number of natural and social sciences, clinical psychology is served best by continued development and appropriation of competing scientific viewpoints rather than by fealty to a single perspective or paradigm. © 2001 John Wiley & Sons, Inc. J Clin Psychol 57: 1125–1132, 2001.
Solvent extraction of Zn(II) by Cyanex 923 and its application to a solid‐supported liquid membrane system
Authors: Alguacil Francisco José , Martínez Susana
Published: September 2002

The extraction of zinc(II) by Cyanex 923 (phosphine oxides mixture) in Solvesso 100 from hydrochloric acid solution has been investigated. The extraction reaction is exothermic. The numerical analysis of metal distribution data suggests the formation of ZnCl2·L2,HZnCl3·2L and H2ZnCl4·2L(L = ligand) in the organic phase with formation constants Kext = 4.1,5.6 × 109 and 6.7 × 109, respectively. The results obtained for zinc(II) distribution have been implemented in a solid‐supported liquid membrane system. The influence of source phase stirring speed, membrane composition and metal concentration on zinc transport have been investigated.

© 2001 Society of Chemical Industry
Ozonation of activated sludge in the recycle stream
Authors: Huysmans A , Weemaes M , Fonseca P A , Verstraete W
Published: September 2002

Intermittent ozonation of a part of the recycle sludge was performed two times a week for a laboratory‐scale reactor at an average ozone dose of 0.019 g O3(gSSozonated)−1. Under these conditions a decrease of about 50% in sludge growth was obtained for the ozone‐treated system, in comparison with the control. As a consequence less sludge had to be removed from the test reactor. Only a slight decrease in quality of effluent was noticed. A comparative cost calculation was made, based on these results, between an ozone‐treated activated sludge system and a traditional activated sludge system.

© 2001 Society of Chemical Industry
Oxidative degradation of 4‐nitrophenol in UV‐illuminated titania suspension
Authors: Lea Jimmy , Adesina Adesoji A
Published: September 2002

An internally‐irradiated annular photoreactor has been used to investigate the oxidative degradation of aqueous 4‐nitrophenol with titania as the photocatalyst. Reaction runs were performed over a 3‐h period and in practically all cases, complete degradation was possible within about 2 h. The kinetics was determined as a function of nitrophenol concentration, oxygen partial pressure, catalyst loading, pH, temperature and light intensity. The reaction was characterised by a relatively low activation energy of 7.83 kJ mol−1 although transport intrusions were negligible. Rate decreased almost exponentially with pH while a quadratic (maximum) behaviour with respect to both oxygen pressure and nitrophenol concentration is symptomatic of self‐inhibition possibly due to the formation of intermediates which competitively adsorb on similar sites to the reactants. Increased catalyst dosage also improved the reaction rate although the possible effects of light scattering and solution opacity caused a drop at loadings higher than about 1.20 g dm−3. Rate, however, has a linear dependency on light intensity, suggesting that hole–electron recombination processes were negligible at the conditions investigated.

© 2001 Society of Chemical Industry
Comparison of filter media, plant communities and microbiology within constructed wetlands treating wastewater containing heavy metals
Authors: Scholz Miklas , Xu Jing , Dodson Hilary I
Published: September 2002

The aim of this study was to investigate the treatment efficiency of passive vertical‐flow wetland filters containing Phragmites australis and/or Typha latifolia and granular media of different adsorption capacities. A cost–benefit analysis was performed on the characteristics of constructed wetlands. Cheap gravel and sand as well as expensive granular activated carbon, charcoal and Filtralite (light expanded clay) were used as filter media. Different concentrations of lead and copper sulfate were added to polluted urban beck inflow water in order to simulate pre‐treated mine wastewater, landfill leachate or highway runoff. The relationships between growth media, microbial and plant communities as well as the reduction of lead, copper, five‐day biochemical oxygen demand (BOD) in particular, and potentially pathogenic bacteria were investigated. A breakthrough of copper within the first 9 weeks was only recorded for filters containing media with limited adsorption capacities. The breakthrough was independent of the presence of plants. However, after maturation of the biomass, which dominated the schmutzdecke and litter zone, lead and copper concentrations were reduced by 97–99% and BOD by 41–60% in all wetlands. There appears to be no additional benefit in using macrophytes and expensive adsorption media in constructed wetlands to enhance metal reduction during the set‐up period of 5 months.

© 2001 Society of Chemical Industry
Fly ash quality, past, present and future, and the effect of ash on the development of novel products
Authors: Hall Martin L , Livingston William R
Published: September 2002

A number of the more important environmental impacts of the operation of large coal‐fired power plants are associated with the very large quantities of solid materials resulting from these processes. These are, principally: coal ash residues, and solid residues of flue gas desulfurisation processes. By far the greater proportion of these materials, generally around 80% of the total solid discards from the electricity supply industry, comprise fly ash from the particulate collection equipment and bottom ash from the hoppers under the economisers and air preheaters of large pulverised coal boilers. The utilisation and disposal of the fly ash residues has been the subject of a great deal of development activity over many decades. In the main, the emphasis has been on the increased use of fly ash materials in high volumes, as constituents of cements and mortars, or for the manufacture of concrete and aggregate materials. The unsold ashes are used for land reclamation and for beneficial landfill, wherever possible. In recent years, there has been increasing interest in the processing of boiler fly ashes to improve ash quality and consistency, and in the manufacture of high‐value secondary products. The utilisation of power station fly ashes depends on their physical and chemical properties, and there have been a number of recent developments in power plant design and operation, which have resulted in significant changes in the characteristics of fly ashes, eg the progressive introduction of NOx emission control technologies and in‐furnace NOx reduction technologies. The increasing interest in the co‐firing of non‐conventional fuels such as petroleum coke and biomass/waste materials has resulted in the production of mixed and more complex materials. The paper will present a review of the major developments, which can affect coal fly ash quality and discuss the impact of these issues on the utilisation of fly ashes as feed materials for the manufacture of high‐value secondary products.

© 2002 Society of Chemical Industry
Glass fibres from waste: production of continuous glass fibres from waste and their application in reinforced plastic material
Authors: Hreglich Sandro , Profilo Bruno , Vallotto Marta , Cioffi Flavio
Published: September 2002

Glass fibres are well‐known reinforcing agents for different kinds of materials. For example, plastics, polyesters and epoxy resins can be reinforced using glass fibres originally developed for electrical applications; the resistance of bituminous materials is increased with the addition of chemically resistant glass fibres, and alkali resistant fibres are used in reinforced concrete. The price of conventional glass fibres is high because of the cost of the raw materials and of the high energy cost involved in the melting process. Therefore, a process which would allow the substitution of the natural raw materials with secondary products such as certain inorganic industrial wastes which have a lower melting temperature, would be of interest because it could increase the saving of energy and natural resources. Moreover, the disposal of industrial wastes in landfill would be reduced.

© 2002 Society of Chemical Industry
Metallic ion removal from aqueous solutions by fly ashes: multicomponent studies
Authors: Rio Sébastien , Delebarre Arnaud , Héquet Valérie , Cloirec Pierre Le , Blondin Jacques
Published: September 2002

Fly ashes from two fluidised bed power plants were tested to remove Pb2+, Cu2+, Cr(III), Ni2+, Zn2+ and Cr(VI) from aqueous solutions. Experimental design methodology was used to study the removal and the leaching as a function of (i) the water pollutant content, (ii) the metal concentration in water, (iii) the pH of the solution and (iv) the addition of lime to fly ashes. The results show that the percentage of adsorbed ions was greater when they were in contact with silico‐aluminous fly ashes than sulfo‐calcic fly ashes, except in the case of the ion Ni2+. The removal of metallic ions increases with increasing pH. A comparison of the adsorption capacity with similar tests carried out with activated carbon or low‐cost sorbents shows that adsorption onto fly ash is an interesting alternative.

© 2002 Society of Chemical Industry
Long term mechanical strength behaviour in fly ash/Portland cement mortars prepared using processed ashes
Authors: Payá J , Borrachero M V , Monzó J , Peris‐Mora E , Bonilla M
Published: September 2002

It is well‐known that some treatments of fly ash may improve its reactivity and consequently the strength of mortars containing these processed ashes. In this paper the effects of treatments on fly ashes are compared: sieving, grinding, and magnetic extractions from aqueous suspensions. The influence of these processed ashes on compressive strength development of mortars containing processed fly ashes for long curing periods was studied. The gain or loss of compressive strength with respect to mortar that contains original ash has been calculated; most mortars present positive values, although for the longest curing times (more than 90 weeks), these values tend towards unity except for ground fly ash mortars. The grinding treatment has proved to be an effective treatment for improving the compressive strength of mortars containing fly ashes over long curing times. The high activity index values versus curing time for mortars containing 60% replacement demonstrate that for high fly ash volume mortars the processing of original ash has very favourable effect on the strength. Moreover, the morphology of the cement/fly ash hydrated matrix of old mortars was analysed by SEM and also thermogravimetric methods have been applied for evaluation of lime content and hydrates. For old mortars containing a high volume of ground fly ashes (60% replacement) residual lime due to hydration of Portland cement has not been detected, suggesting that the optimum replacement in order to produce the maximum quantity of pozzolanic reaction products would be lower than 60%.

© 2002 Society of Chemical Industry
Thermal analysis of fly ashes sourced from European non‐blended coals
Authors: Stanton Kenneth T , Towler Mark R , Mooney Patrick , Hill Robert G , Querol Xavier
Published: September 2002

Fly ashes exist as a mixture of major amorphous phases and minor crystalline phases. For commercial applications, such as in concretes and for the production of zeolites, it would be desirable to be able to predict the reactivity of fly ashes. The amorphous phase dominates degradation behaviour, because glasses have a higher potential energy than the equivalent crystal structure and the variation of bond angles and distances in a glass make the bond breakage easier. Despite the large quantities of fly ash produced annually by coal‐burning power plants, there have been very few studies investigating the microstructure and composition of the amorphous component. In particular, there has been little research undertaken in measuring the glass transition temperature (Tg), which can be directly correlated to the chemical reactivity of the glass phase. Thirteen European fly ashes were used for the present study. Differential scanning calorimetry (DSC) was employed to determine the presence of transition temperatures and any other thermal events (exotherms or endotherms) in the glassy phase of the fly ashes. Several different but distinct behaviours were evident in the DSC traces with Tg values visible for six of the ashes. The results suggest that thermal analysis has potential as a technique for fly ash characterisation.

© 2002 Society of Chemical Industry
Encouraging prospects for recycling incinerated sewage sludge ash (ISSA) into clay‐based building products
Authors: Anderson Michael
Published: September 2002

Staffordshire University has recently completed a laboratory investigation into the potential utilisation of incinerated sewage sludge ash (ISSA) which has now become a serious disposal problem in the United Kingdom. This study involved a physical, chemical and ceramic evaluation of a source of ISSA produced at a newly commissioned sewage sludge incinerator sited near Manchester, initially to establish its level of variability on a day‐to‐day basis. Subsequently, feedstocks from two commercial brick factories both using raw materials of contrasting ceramic properties were obtained to examine the effect of their partial replacement by this source of ISSA. This work programme involved fabricating and firing experimental test‐samples (containing 5% dry w/w ISSA substitution) by the plastic‐extrusion forming method which is employed at both brickworks to manufacture their respective products. Standard ceramic testing procedures were subsequently carried out on the products containing ISSA and compared with those of the normal brick products fabricated in parallel. From the positive results obtained it is believed that the introduction of this source of ISSA as a new raw material for use in brick manufacture potentially offers attractive prospects. Moreover, its application in this identified role would provide an innovative alternative to its current landfill disposal, while also offering a direct contribution towards maximising the conservation of traditional brickmaking raw material reserves.

© 2002 Society of Chemical Industry
Zeolite synthesis from a high Si–Al fly ash from East China
Authors: Zeng R , Umaña J C , Querol X , Lopez‐Soler A , Plana F , Zhuang X
Published: September 2002

A high Al–Si Chinese fly ash from Dou He power plant (Tangshan city, Hebei Province, Eastern China) was selected as starting material of the zeolitisation process. Zeolitic material was obtained by conventional alkaline activation using NaOH and KOH solutions. The process of synthesis was optimised by applying a wide range of reaction temperature, time and activation reagent concentrations. A high solution/fly ash ratio was used in order to dissolve highly resistant Al–Si phases such as mullite. High yields were obtained with both KOH and NaOH solutions. Final products reached a cation exchange capacity (CEC) of up to 2.3 meq g−1. Major zeolites obtained with a high CEC were: NaP1, KM and F‐linde zeolite. The low contents of major impurities of this fly ash enhance the potential application for the synthesis of zeolites for waste‐water treatment.

© 2002 Society of Chemical Industry
Effect of precursors on surface and catalytic properties of Fe/TiO2 catalysts
Authors: Pecchi Gina , Reyes P , López T , Gómez R , Moreno A , Fierro J L G
Published: September 2002

Titania‐supported iron (5 wt%) catalysts were prepared by a sol–gel method using different gelation pH and metal precursors (Fe(II) and Fe(III)). Characterization data of calcined catalysts revealed that, irrespective of the nature of the metal precursor, iron is present in all cases as ferric oxide. However, the crystalline phase exhibited by titania does depend on the metal precursor used. The catalytic activity of the catalysts, tested in the combustion of methane at atmospheric pressure, is not related to the dispersion of iron oxide. Thus, Fe3+ ions may be obtained in two extreme situations; one highly dispersed in which Fe3+ ions are placed in the titania network and another in which large Fe2O3 crystals are located on the surface of the catalyst. The former exhibits the best performance in the combustion of methane.

© 2002 Society of Chemical Industry
Preparation of dry powder dispersions for non‐viral gene delivery by freeze‐drying and spray‐drying
Authors: Seville P. C. , Kellaway I. W. , Birchall J. C.
Published: September 2002

Background

Dry powder dispersion devices offer potential for delivering therapeutic macromolecules to the pulmonary epithelia. Previously, freeze‐drying (lyophilisation) has been the accepted method for preparing dried formulations of proteins and non‐viral gene vectors despite the respirability of such powders being inadequate without further processing. In this study we compare the utility of freeze‐drying and spray‐drying, a one‐step process for producing dry and respirable powders, as methods for preparing non‐viral respiratory gene delivery systems.

Methods

Lipid:polycation:pDNA (LPD) vectors comprising 1,2‐dioleoyl‐3‐trimethylammoniumpropane (DOTAP), protamine sulphate and pEGFP‐N1 in 3% lactose solution were either snap‐frozen and lyophilised or spray‐dried. Lyophilised powder was used as recovered or following coarse grinding. Structural integrity of dehydrated pDNA was assessed by agarose gel electrophoresis and powder particle size determined by laser diffraction. The apparent structure of the systems was visualised by scanning and transmission electron microscopy with the biological functionality quantified in vitro (A549 human lung epithelial cell line) by Green Fluorescent Protein (GFP) associated fluorescence.

Results

Lyophilisation produced large, irregularly shaped particles prior to (mean diameter ∼21 µm) and following (mean diameter ∼18 µm) coarse grinding. Spray‐drying produced uniformly shaped spherical particles (mean diameter ∼4 µm). All dehydrated formulations mediated reporter gene expression in A549 cells with the spray‐dried formulation generally proving superior even when compared with freshly prepared LPD complexes. Biological functionality of the LPD dry powders was not adversely affected following 3 months storage.

Conclusions

Spray‐drying has utility for producing stable, efficient and potentially respirable non‐viral dry powder systems for respiratory gene delivery. Copyright © 2002 John Wiley & Sons, Ltd.
Human cell lines engineered for tetracycline‐regulated expression of tumor suppressor candidate genes from a frequently affected chromosomal region, 3p21
Authors: Protopopov Alexei I. , Li Jinfeng , Winberg Gösta , Gizatullin Rinat Z. , Kashuba Vladimir I. , Klein George , Zabarovsky Eugene R.
Published: September 2002

Background

We modified a tetracycline‐regulated system that can control the activity of individual genes quantitatively and reversibly in transgenic mammals. Despite these advances, there remained one problem in the intensive use of the tet‐system: the limited range of acceptor cell lines, expressing a tetracycline‐controlled transcriptional activator (tTA). This study describes in detail new vectors and a unifying strategy to generate tTA‐expressing cell lines.

Method

Two retroviral vectors pLNCtTA‐hCMV and pLNCtTA‐EF1α coding for the tTA were used to engineer cell lines to constitutively express tTA. New expression vectors pETE‐Hyg and pETE‐Bsd were also created that replicate in episomal form in human cells and facilitate tetracycline‐regulated expression of targeted genes.

Results

The primate‐tropic retroviruses efficiently delivered the regulatory tTA gene into 12 selected human cancer cell lines. Two candidate tumor suppressor genes from the human 3p21–p22 region MAPKAPK3 (3pK) and MLH1 were cloned into the episomal vector and transfected into engineered A9 and KRC/Y cells. The transfectants were subcutaneously grown in SCID mice, and the expression of the transgene was successfully controlled in vivo by tetracycline administered ad libitum in drinking water. The experiments demonstrated that both transgenes did not antagonize the tumorous growth of these cells.

Conclusions

New retroviral and episomal vectors appear particularly suited for tight regulation of genes that cause suppression of cell growth. The generated cell lines can be used in various applications to study the effect of an inducible transgene in human cancer cells. Copyright © 2002 John Wiley & Sons, Ltd.
The depoliticization of Karl Lashley: A response to Dewsbury
Authors: Weidman Nadine
Published: September 2002

In this response to Donald Dewsbury's article, I address Dewsbury's criticisms of my interpretation of Karl Lashley by, first, disputing Dewsbury's characterization of my historiographic stance. I then go on to address Dewsbury's specific points, particularly regarding Lashley's racism and hereditarianism, which I argue are central to an understanding of the context of his science. I conclude by criticizing Dewsbury's proposed personality theory of Lashley on the grounds that it depoliticizes Lashley by psychologizing him. © 2002 Wiley Periodicals, Inc.
Freud's “bad conscience”: The case of Nietzsche's Genealogy
Authors: Greer Scott
Published: September 2002

This article develops the argument that Friedrich Nietzsche influenced several aspects of Freud's later writings by illustrating, in particular, the impact of Nietzsche's On the Genealogy of Morals on Freud's Civilization and its Discontents. The theoretical and conceptual schemes represented in Freud's Discontents are found to bear a remarkable similarity to Nietzsche's Genealogy on a number of highly specific points. It is suggested that “das Es,” “Uber‐ich,” and “bad conscience,” concepts central to Freud's moral theory of mind, are at least partly derived from Nietzsche. Moreover, Freud's phylogenetic theory of guilt is based upon premises found in Nietzsche, as are specific details relating to ideas on human prehistory and the ancestral family. Based on this evidence, a re‐examination of the moral and social dimensions of Freud's “structural” model may be in order. © 2002 Wiley Periodicals, Inc.
Commentary on ‘The economics of landmine clearance: case study of Cambodia’
Authors: Paterson Ted
Published: September 2002

A recent cost‐benefit analysis of landmine clearance in Cambodia (Harris, JID 12(2), 2000) reported a net present value (NPV) of minus $3,434 million, and concluded landmine clearance using existing technologies is not economically justified for Cambodia. Professor Harris suggested higher returns would accrue to investments in de‐mining technology, while aid funds for landmine clearance should be reallocated to meet other development objectives. However, the methodology used massively overstates the present value of de‐mining costs while the estimated benefits are far too low. More fundamentally, the specification of the model makes it suitable only for an ‘all‐or‐nothing’ decision whether to rid Cambodia entirely of landmine contamination, and does not allow the analysis of targeted clearance of priority land. With appropriate adjustments, the economics of landmine clearance in Cambodia are not bleak, and may well yield positive rates of return in NPV terms. Copyright © 2001 John Wiley & Sons, Ltd.