bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fire Model Analysis and Experimental Validation on Smoke Compartments
Authors: Kee-Chiang Chung , Yu-Lieh Wu , Hsien-Sheng Tung 
Published: July 2003

Referring to fire accidental data, more than half the deaths from accidental fires are due to smoke rather than fire. In addition to using smoke curtain to accumulate smoke, it is necessary to consider appropriate smoke compartmentation effects for practical smoke control design. Otherwise evacuation and extinguishing systems would not be operated adequately. However, under the existing fire code of Taiwan, there are many constraints applied to construct smoke compartments inside buildings. Sometimes, it cannot work out for practical design purposes, such as the area of smoke compartments were limited without exception of performance consideration. Therefore, the purpose of this paper is to investigate the phenomena related to fire, heat, and smoke during some postulated fire scenarios occurring in a multicompartment enclosure and the distribution of smoke flow field. Two different fundamental fire models, CFAST and SMARTFIRE, are used for analyzing and predicting the experimental results from a full-scale test. The comparison results show quite reasonable variations between numerical simulation and experimental data. Although the temperature data are higher than experimental data, the predicted smoke layer heights are lower than experimental data. However, the fire models present correct trend of accumulated smoke layer height and temperature distributions in a multi-compartment structure.
The Development of Porous Alginate/Elastin/PEG Composite Matrix for Cardiovascular Engineering
Authors: Chandy Thomas , Rao Gundu H. R. , Wilson Robert F. , Das Gladwin S. 
Published: July 2003

The development of suitable three-dimensional matrices for the maintenance of cellular viability and differentiation is critical for applications in tissue engineering and cell biology. To this end, gel matrices of different proportions of alginate/elastin/polythylene glycol (Alg/Ela/PEG) were prepared and examined. The composite matrix membranes were evaluated for their porous scaffold using SEM, enzymatic degradation and water content. An equal blend of Alg/Ela with a ratio of Alg/Ela: PEG (7: 3) was selected for fabricating Alg/Ela/PEG scaffolds for this study. The Alg/Ela/PEG membranes fabricated at 20°C and -20°C had a mean surface pore size of 35-45 μm. However, their ultrastructures had shown bigger pore structures (60-75 μm) compared to their surface. It is interesting to note that the membranes of Alg/Ela/PEG prepared at 20°C had larger ultrastructural pores than that of membranes prepared at -20°C. Further, the SEM studies revealed that in the absence of PEG the composite membranes of Alg/Ela formed with less porous structures. The water content of membranes prepared at 20°C was higher with Alg/Ela/PEG (61.6 ± 4.8%), compared to Alg/Ela (49.9 ± 0.3%). The enzymatic degradation and water content studies also revealed that the membranes fabricated at -20°C had high water uptake and low enzymatic degradation, as that of the membranes prepared at 20°C. In other words the larger pore structured membranes had less water content and high degradation profile. This study proposes that this novel composite matrix produces a hierarchical structure that is useful for generating tissue scaffolds for repairing the failing cardiac muscles. However, more detailed investigations with cytocompatibility studies are needed to find applications.
Water Sorption, Solubility and Dimensional Changes of Denture Base Polymers Reinforced with Short Glass Fibers
Authors: Polat Tülin N. , Karacaer Özgül , Tezvergil Arzu , Lassila Lippo V. J. , Vallittu Pekka K. 
Published: July 2003

The aim of this study was to determine water sorption, solubility and dimensional stability of injection and compression-molded polymethyl methacrylate based denture base polymer that was reinforced with various concentrations and lengths of E-glass fibers. For water sorption and solubility, 20 test groups with different fiber contents and lengths of fibers were prepared. Test specimens without fibers were used as a control. The water sorption and solubility was measured after 90 days water storage. For dimensional stability, rhombic test specimens were prepared and the dimensional changes were measured after processing, drying and storing in water for 4 days and 30 days and were compared with those on the brass model. The water sorption and solubility of injection-molded denture base polymer was lower compared to compression-molded specimens ( p<0.05). The dimensional accuracy of denture base polymer was not affected with fiber reinforcement ( p>0.05).
Surface Reactivity of Calcium Phosphate Based Ceramics in a Cell Culture System
Authors: John Annie , Varma H. K. , Kumari T. V. 
Published: July 2003

Surface reactivity of Calcium Phosphate materials - Hydroxyapatite (HA), Tricalcium Phosphate (β-TCP), Hydroxyapatite-Tricalcium Phosphate (HA-TCP) were elucidated in a cell culture system. MG-63 osteoblast-like cells were seeded onto the ceramic discs to evaluate changes in the cell morphology and functionality with respect to the different substrates. The dissolution and re-precipitation of calcium phosphate phases on the surface of the discs in the culture medium was found to be prominent on β-TCP when compared with HA. Low calcium (Ca), magnesium (Mg) and alkaline phosphatase (ALP) levels and high phosphorous (P) levels in the medium of β-TCP were observed. This indicated that P must have leached out into the medium from β-TCP and Ca in turn deposited from the medium onto β-TCP resulting in the apatite phase transformation. The low ALP activity in β-TCP medium is however an indication of low osteoblastic activity. Under the phase contrast microscope, the osteoblast cells around HA material were found to be confluent and viable, while in the vicinity of β-TCP only cellular debris was observed. In the case of HA-TCP, only a few viable cells surrounded the material amidst the debris. Scanning electron microscopy revealed numerous cells on the surface of HA showing different cell behaviour like anchorage, attachment, adhesion and spreading in the early time period as the surface was only slightly disturbed with re-crystallisation. But with time the entire surface of HA had changed due to precipitation and re-crystallization which did not support cell behaviour while the cells surrounding the material showed normal growth. On the contrary, cells were scarcely observed on the entirely changed surface of β-TCP and HA-TCP even from the earlier days of the culture and the morphology of cells surrounding the material too started changing. These results establish that HA promoted the activity of osteoblast cells. HA surface remained unaltered for some time, while the surface of β-TCP underwent dissolution of surface ions and resulted in the re-crystallization of apatite over the surface. The resulting changes in the surrounding milieu of β-TCP with high phosphate and low Ca levels probably was responsible for the death of the cells.
Damage Evolution in Elasto-Plastic Materials - Material Response Due to Different Concepts
Authors: Olsson Mattias , Ristinmaa Matti 
Published: July 2003

The purpose of this paper is to show that shortcomings exist in the plasticity induced damage theories. Existing phenomenological thermodynamic approaches used for describing elasto-plasticity coupled with damage are therefore evaluated. Within the concept of effective stress both the postulate of strain equivalence and the postulate of (complementary) energy equivalence, as well as extensions of the postulates, are considered. As a prototype model the von Mises plasticity model coupled with isotropic damage is considered. Simulations of a strain-controlled uniaxial model are also performed. The results reveal that a mapping, similar to that of the stress, of both the kinematic and isotropic hardening variables is to be preferred. More interesting is that, irrespective of the postulate employed, the elastic strain will not equal zero when failure takes place, i.e. the interpretation of elastic strain is lost. From the results it is also concluded that (complementary) energy equivalence have some undesirable properties.
Increased Concurrency between Industrial and Engineering Design Using CAT Technology Combined with Virtual Reality
Authors: Wickman Casper , Söderberg Rikard 
Published: July 2003

These days, when an industrial design concept is evaluated in an aesthetic manner, all models used are nominal. If the design is evaluated with nominal models, variation aspects and design solutions that would greatly influence the overall quality appearance might not be discovered until the first test series are made. By using nonnominal models during the design process, important geometric aspects can be issued, and the need for physical test series can be reduced. In the automotive industry, especially in body design, the relationships between doors, hoods, fenders and other panels are critical for quality appearance. This article suggests how combining traditional Computer Aided Tolerance (CAT) tools with modern Virtual Reality (VR) tools has the potential to enhance concurrency between industrial and engineering design and provide support for the geometry process in early phases. Traditional nonnominal verification can then already be conducted in the concept phase using digital models instead of physical. A VR-CAT tool supported geometry design process is proposed from a holistic point of view. Results and indications from a case study, where prescribed VR-CAT tool has been tried out in an on going project at Volvo Cars is presented.
The Provision of Information by Health Promotion Units to People of Asian Origin Living in the UK
Authors: Phul A. , Bath P. A. , Jackson M. G. 
Published: July 2003

Studies suggest that people with a limited command of English find it difficult to obtain adequate access to healthcare and health information. Language barriers mean that they have insufficient knowledge about the range of health services available, and very little health-related information meets their individual language needs. The aim of the study discussed in this paper was to examine the potential for new technology to provide better access to health information for Asian people who cannot communicate in English. A questionnaire was sent to a purposive sample of 90 HPUs (health promotion units) to gain some knowledge from health promotion specialists concerning this issue. The results of this study revealed that there are gaps in information provision for non-English speaking Asian people. Videos and verbal presentations were considered to be the two most effective formats of information for use with this target group. Respondents valued interactivity, as they said that people should be able to ask questions about the health information they see. HPUs are beginning to attempt to use new technology to provide health information in Asian languages, although many respondents are aware of potential problems associated with this. The study concludes that new technology can be useful if simple, user-friendly systems such as touch-screens are used. New technologies can also be made more interactive than leaflets and videos.
Promoting higher‐order learning benefits by building lower‐order mnemonic connections
Authors: Carney Russell N. , Levin Joel R. 
Published: June 2003

AbstractTwo experiments were conducted in an effort to combine a mnemonic strategy for remembering individual items with a mnemonic procedure for remembering, and reasoning about, inter‐item relationships. In Experiment 1, students using the combined mnemonic approach were able to identify more individual items (fish names from their pictures) and were subsequently able to remember more components of six studied hierarchies (order, family, and species names of the fish) than did students in an ‘own best method’ control condition. Additionally, and importantly, mnemonic students outperformed control students on an analogy task requiring inferences about superordinate, subordinate, and coordinate relationships. In Experiment 2, the initial number of to‐be‐learned fish was reduced so that the performance of both mnemonic and control students was comparable with respect to fish identification. Despite such item‐level comparability, an advantage for mnemonically instructed students was observed on both immediate and two‐day‐delayed hierarchy tests. We suggest that by cementing lower‐order connections, mnemonic strategies facilitate students' learning of higher‐order information. Copyright © 2003 John Wiley & Sons, Ltd.
Creating a histology–embryology free digital image database using high‐end microscopy and computer techniques for on‐line biomedical education
Authors: Silva‐Lopes Victor W. , Monteiro‐Leal Luiz H. 
Published: June 2003

AbstractThe development of new technology and the possibility of fast information delivery by either Internet or Intranet connections are changing education. Microanatomy education depends basically on the correct interpretation of microscopy images by students. Modern microscopes coupled to computers enable the presentation of these images in a digital form by creating image databases. However, the access to this new technology is restricted entirely to those living in cities and towns with an Information Technology (IT) infrastructure. This study describes the creation of a free Internet histology database composed by high‐quality images and also presents an inexpensive way to supply it to a greater number of students through Internet/Intranet connections. By using state‐of‐the‐art scientific instruments, we developed a Web page (http://www2.uerj.br/∼micron/atlas/atlasenglish/index.htm) that, in association with a multimedia microscopy laboratory, intends to help in the reduction of the IT educational gap between developed and underdeveloped regions. Anat Rec (Part B: New Anat) 273B:126–131, 2003. © 2003 Wiley‐Liss, Inc.
Electronic removal of encrustations inside the Steinheim cranium reveals paranasal sinus features and deformations, and provides a revised endocranial volume estimate
Authors: Prossinger Hermann , Seidler Horst , Wicke Lothar , Weaver Dave , Recheis Wolfgang , Stringer Chris , Müller Gerd B. 
Published: June 2003

AbstractFeatures in the endocranium, as revealed by computed tomography (CT) scans of largely complete mid‐Pleistocene crania, have helped elucidate unexpected affinities in the genus Homo. Because of its extensive encrustations and deformations, it has been difficult to repeat such analyses with the Steinheim cranium. Here, we present several advances in the analysis of this Homo heidelbergensis cranium by applying filter algorithms and image editing techniques to its CT scan. First, we show how the encrustations have been removed electronically, revealing interesting peculiarities, particularly the many directions of the deformations. Second, we point out similarities and differences between the frontal and sphenoidal sinuses of the Steinheim, Petralona, and Broken Hill (Kabwe) crania. Third, we assess the extent of the endocranial deformations and, fourth, their implications for our estimation of the braincase volume. Anat Rec (Part B: New Anat) 273B:132–142, 2003. © 2003 Wiley‐Liss, Inc.
The four‐state model of a linear lattice: Application to ligand‐controlled hybridization of short duplex DNAs
Authors: Benight Albert S. 
Published: June 2003

AbstractAn algorithm for calculating the order–disorder transition of a four‐state linear lattice is presented. Recursion schemes for the probabilities of each site along the lattice occupying one of the four possible states were derived following the work of D. Poland (Biopolymers, 1974, Vol. 13, pp. 1859–1871) and H. Tachibana and A. Wada (Biopolymers, 1982, Vol. 21, pp. 1873–1885). The algorithm was parameterized to consider melting of short duplex DNA in the presence of duplex and single‐strand binding ligands. Model calculations were performed for two 31 base‐pair duplex DNAs with very different percent guanine–cytosine base pairs, and thus very different thermodynamic stabilities. In the absence of ligands, calculated melting curves of the two DNAs under identical solvent conditions and identical concentrations were separated by over 15°C. In the presence of either duplex or single‐strand binding ligands, if a sequence dependence to ligand binding is assumed, the melting curves of the two DNAs can be made to coalesce, i.e., stability of the two DNAs can be normalized! This example demonstrates the feasibility of controlling hybridization of short DNAs by sequence specific ligand binding. © 2003 Wiley Periodicals, Inc. Biopolymers 69: 405–420, 2003
A simple lattice model that exhibits a protein‐like cooperative all‐or‐none folding transition
Authors: Kolinski Andrzej , Gront Dominik , Pokarowski Piotr , Skolnick Jeffrey 
Published: June 2003

AbstractIn a recent paper (D. Gront et al.,Journal of Chemical Physics, Vol. 115, pp. 1569, 2001) we applied a simple combination of the Replica Exchange Monte Carlo and the Histogram methods in the computational studies of a simplified protein lattice model containing hydrophobic and polar units and sequence‐dependent local stiffness. A well‐defined, relatively complex Greek‐key topology, ground (native) conformations was found; however, the cooperativity of the folding transition was very low. Here we describe a modified minimal model of the same Greek‐key motif for which the folding transition is very cooperative and has all the features of the “all‐or‐none” transition typical of real globular proteins. It is demonstrated that the all‐or‐none transition arises from the interplay between local stiffness and properly defined tertiary interactions. The tertiary interactions are directional, mimicking the packing preferences seen in proteins. The model properties are compared with other minimal protein‐like models, and we argue that the model presented here captures essential physics of protein folding (structurally well‐defined protein‐like native conformation and cooperative all‐or‐none folding transition). © 2003 Wiley Periodicals, Inc. Biopolymers 69: 399–405, 2003
Biophysical and structural property of the putative DNA‐binding protein, BldB, from Streptomyces lividans
Authors: Mishig‐Ochiriin Tsogbadrakh , Won Hyung‐Sik , Lee Chang‐Jin , Kang Sa‐Ouk , Lee Bong‐Jin 
Published: June 2003

AbstractThe bldB gene from Streptomyces lividans was cloned, and its product was overexpressed in Escherichia coli using a T7 expression system. Gel mobility shift assays showed that the BldB protein was functionally expressed in the E. coli system and may negatively regulate its own expression. The comparative analyses by mass spectrometry, Tris‐Tricine sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS‐PAGE), and analytical ultracentrifuge established that BldB is a dimeric protein with 24 kDa molecular mass, of which monomers do not covalently interact with each other. Gel filtration result implied that the protein shape would not be globular. More detailed structural investigations by CD and NMR spectroscopy confirmed that the majority of the BldB structure is not only disordered but also highly flexible. The highly reversible, but hardly cooperative, property of the thermal denaturation also supported the idea that the protein structure is not compact. However, the existence of a structural nucleus, of which the ordered conformation remains stabilized even at more than 80°C, was evidenced. The overall structure and the thermal stability of BldB were sensitive to pH, suggesting a proton‐induced conformation change. Altogether, the results provide the first detailed characterization on the biophysical and structural property of the putative DNA‐binding protein, BldB. © 2003 Wiley Periodicals, Inc. Biopolymers 69: 343–350, 2003
Anchorage of oligonucleotide hybridization by tethered phenazine nucleoside analogue
Authors: Zozulya V. , Blagoi Yu. , Dubey I. , Fedoryak D. , Makitruk V. , Ryazanova O. , Shcherbakova A. 
Published: June 2003

AbstractUV absorption and fluorescence techniques with a thermal denaturation procedure were used in studies of the anchorage of an oligonucleotide hybridization by a covalently tethered nucleoside analogue of an intercalating imidazophenazine derivative (Pzn). The formation by the (dT)10Pzn conjugate of the duplex complex with (dA)15 and the triplex complex with (dA)15 or poly(dA)·poly(dT) was studied in buffered solutions with 0.11 and/or 1M sodium ions at the oligomer strand concentration of 10 μM. Because of the Pzn emission sensitivity to the interaction with adenine bases, a fluorescence technique was found to be effective in the detection of melting transitions. The attached Pzn substantially enhanced the thermal stability of complexes formed by (dT)10 because of the intercalation mechanism, which increased the temperature of half‐dissociation of the duplex by 10–12°C and of the triplexes by ∼13°C. With the assumption of a two‐state model of transition, the thermodynamic parameters for duplex formations were derived. The investigated variant of conjugation has a certain advantage over the widely used attachment via a flexible linker, consisting of a predetermined location of the Pzn chromophore in target sequences that makes it useful as a fluorescent reporter of the hybridization correctness. Molecular modeling was used to construct the geometries of the intercalation sites that turned out to be in conformity with the behavior of the Pzn fluorescence. © 2003 Wiley Periodicals, Inc. Biopolymers (Biospectroscopy), 2003
Direct determination of estriol 3‐ and 16‐glucuronides in pregnancy urine by column‐switching liquid chromatography with electrospray tandem mass spectrometry
Authors: Yang Yoon Jung , Lee Jeongae , Choi Man Ho , Chung Bong Chul 
Published: June 2003

AbstractUsing column‐switching liquid chromatography/tandem mass spectrometry (LC‐MS/MS), we developed an improved analytical method of urinary estriol glucuronides. This new method is derived predominantly from maternal and fetal precursors in pregnancy. We used in the following procedure: first, we filtered urine samples with a membrane filter. Next, we directly injected the 50 µL aliquot of urine samples onto a pre‐column. Then, after activating the column‐switching valve, we backflushed the loaded samples onto the C18 analytical column. Urine samples can be assayed within 20 min without any sample preparation steps. We monitored separated estriol glucuronides by negative electrospray ionization (ESI) and selected‐reaction monitoring (SRM). The calibration range of estriol‐3‐glucuronide (E3‐3G) and estriol‐16‐glucuronide (E3‐16G) was 0.1–20 µg/mL and the linearity of the method was 0.9984 for E3‐3G and 0.9987 for E3‐16G. The limits of detection at a signal‐to‐noise (S/N) ratio of 3 were 10 ng/mL (E3‐3G) and 5 ng/mL (E3‐16G). The analytical recovery was over 85% and, in general, inter‐day and intra‐day variability for precision and accuracy were less than 10%. When applied to a pregnancy urine sample to biomedical monitoring of the function of the maternal/fetal unit, the proposed method allowed rapid and sensitive screening for the detection of E3‐3G and E3‐16G. Copyright­© 2003 John Wiley & Sons, Ltd.