bluuebunny/crossref_metadata_2025_split huggingface dataset:
Engineering cartilage‐like tissue using human mesenchymal stem cells and silk protein scaffolds
Authors: Meinel Lorenz , Hofmann Sandra , Karageorgiou Vassilis , Zichner Ludwig , Langer Robert , Kaplan David , Vunjak‐Novakovic Gordana 
Published: October 2004

AbstractHuman mesenchymal stem cells (hMSC) derived from bone marrow aspirates can form the basis for the in vitro cultivation of autologous tissue grafts and help alleviate the problems of immunorejection and disease transmission associated with the use of allografts. We explored the utility of hMSC cultured on protein scaffolds for tissue engineering of cartilage. hMSC were isolated, expanded in culture, characterized with respect to the expression of surface markers and ability for chondrogenic and osteogenic differentiation, and seeded on scaffolds. Four different scaffolds were tested, formed as a highly porous sponge made of: 1) collagen, 2) cross‐linked collagen, 3) silk, and 4) RGD‐coupled silk. Cell‐seeded scaffolds were cultured for up to 4 weeks in either control medium (DMEM supplemented with 10% fetal bovine serum) or chondrogenic medium (control medium supplemented with chondrogenic factors). hMSC attachment, proliferation, and metabolic activity were markedly better on slowly degrading silk than on fast‐degrading collagen scaffolds. In chondrogenic medium, hMSC formed cartilaginous tissues on all scaffolds, but the extent of chondrogenesis was substantially higher for hMSC cultured on silk as compared to collagen scaffolds. The deposition of glycosaminoglycan (GAG) and type II collagen and the expression of type II collagen mRNA were all higher for hMSC cultured on silk than on collagen scaffolds. Taken together, these results suggest that silk scaffolds are particularly suitable for tissue engineering of cartilage starting from hMSC, presumably due to their high porosity, slow biodegradation, and structural integrity. © 2004 Wiley Periodicals, Inc.
Quartz crystal microbalance‐based measurements of shear‐induced senescence in human embryonic kidney cells
Authors: Jenkins M. S. , Wong K. C. Y. , Chhit O. , Bertram J. F. , Young R. J. , Subaschandar N. 
Published: October 2004

AbstractFluid shear and other mechanical forces play an important role in the normal biophysical, biochemical, and gene regulatory responses of vertebrate tissue that are reflected in the expression of normal cell differentiation, growth, and function. Despite some promising work reported on the application of the quartz crystal microbalance (QCM) to both prokaryote and eukaryote cells over the last decade, QCM has yet to be successfully applied to cells in culture under conditions of flow‐induced shear. In this study, high sensitivity QCM in conjunction with fluid modelling was used to monitor the onset of senescence in immortalised human embryonic kidney cells under laminar shear stresses of between 0.04 and 335 dyne/cm2. The feasibility of this approach as a means of quantification and characterisation of cell physiological response and adhesion are explored and discussed. © 2004 Wiley Periodicals, Inc.
Movements at the low back during normal walking
Authors: Rice J. , Kaliszer M. , Walsh M. , Jenkinson A. , O'Brien T. 
Published: October 2004

AbstractWe present a technique for measuring the kinematics of the functional low back during normal gait. We have used a similar technique previously to measure low back movement simultaneously with hip, knee, and ankle movement during the toe‐touching manoeuvre. We noted that movements at the low back were biphasic. The greatest low back movements were found to occur in the transverse plane (mean = 23°), whereas a mean of 17° movement occurred in the coronal plane and only 5° movement in the sagittal plane. These findings confirm, using a non‐invasive technique, that there are significant ranges of movement at the low back during walking and lend some support to the theory that rotational movement at the low back is a major component of human locomotion. Clin. Anat. 17:662–666, 2004. © 2004 Wiley‐Liss, Inc.
Imaging microscopy of the middle and inner ear: Part I: CT microscopy
Authors: Lane John I. , Witte Robert J. , Driscoll Colin L.W. , Camp John J. , Robb Richard A. 
Published: October 2004

AbstractAnatomic definition of the middle ear and bony labyrinth in the clinical setting remains limited despite significant technological advances in computed tomography (CT). Recent developments in ultra‐high resolution imaging for use in the research laboratory on small animals and pathologic specimens have given rise to the field of imaging microscopy. We have taken advantage of this technique to image a human temporal bone cadaver specimen to delineate middle ear and labyrinthine structures, only seen previously using standard light microscopy. This approach to the study of the inner ear avoids tissue destruction inherent in histological preparations. We present high‐resolution MicroCT images of the middle ear and bony labyrinth to highlight the utility of this technique in teaching radiologists and otolaryngologists clinically relevant temporal bone anatomy. This study is not meant to function as a complete anatomic atlas of the temporal bone. We have selected several structures that are routinely delineated on clinical scanners to highlight the utility of imaging microscopy in displaying critical anatomic relationships in three orthogonal planes. These anatomic relationships can be further enhanced using 3D volume rendering. Clin. Anat. 17:607–612, 2004. © 2004 Wiley‐Liss, Inc.
Design and operational aspects of airlift bioreactors for petroleum biodesulfurization
Authors: Mehrnia Mohammad Reza , Bonakdarpour Babak , Towfighi Jafar , Akbarnejad Mohammad Mehdi 
Published: October 2004

AbstractThe effects of important design and operating parameters on the hydrodynamics and oxygen transfer characteristics of draft‐tube airlift bioreactors (DTABs) were investigated. A water‐in‐kerosene microemulsion system was used inside the DTAB to simulate the physicochemical properties of the fermentation broths used in petroleum biodesulfurization (BDS) processes. For this system, the churn‐turbulent regime occurred at higher air flow rates compared to those of water‐based systems. An increase in draft‐tube surface area was found to be a more effective means for enhancement of both mixing and oxygen transfer than an increase in top‐section surface area expansion. An increase in the draft‐tube height and liquid level had a similar effect on the performance of DTABs containing the microemulsion or water‐based media. Correlations were developed that predicted overall and local gas holdups, liquid velocity, mixing time, and overall volumetric oxygen transfer coefficient as a function of aeration rate, bioreactor geometry, and liquid level inside the DTAB containing water‐in‐oil microemulsion for all experimental conditions examined. © 2004 American Institute of Chemical Engineers Environ Prog, 23: 206–214, 2004
Waste minimization techniques and options for the wet and pretreatment sections of coil coating plants
Authors: Brown Nicola J. , Dempster Heather J. 
Published: October 2004

AbstractWaste minimization has proven successful in recent years for many companies in reducing their raw material and utility consumption and costs as well as their waste‐treatment and disposal costs. Although waste minimization opportunities can be identified through observation of plant operation practices and through application of generalized heuristic principles, many opportunities are determined only through analysis of plant data. In this study, two preassessment techniques (scoping audit and true cost of waste assessment) and two techniques for a more detailed assessment (mass balances and monitoring and targeting) were evaluated to determine whether they identified similar waste minimization opportunities on two coil coating lines. All techniques identified similar waste minimization opportunities, although the true cost of waste assessment and the monitoring and targeting analysis were found to be the most accurate in prioritizing the waste minimization opportunities. The raw material “scope to save” percentage in the scoping audit requires modification for application to South African industry. General waste minimization options for the wet and pretreatment sections of the coil coating industry are also presented. © 2004 American Institute of Chemical Engineers Environ Prog, 23: 185–193, 2004
Discrete breakpoint mapping and shortest region of overlap of chromosome arm 1q gain and 1p loss in human hepatocellular carcinoma detected by semiquantitative microsatellite analysis
Authors: Nishimura Takafumi , Nishida Naoshi , Itoh Teruaki , Komeda Toshiki , Fukuda Yoshihiro , Ikai Iwao , Yamaoka Yoshio , Nakao Kazuwa 
Published: October 2004

AbstractRecurrent chromosomal gain at 1q is one of the most common features of human hepatocellular carcinoma (HCC), but how the gain at 1q contributes to hepatocarcinogenesis is still unclear. To identify the target genes, precise determination of the shortest region of overlap (SRO) and of breakpoints is necessary. Similarly, the role of loss at 1p, which is also a major cytogenetic aberration in HCC, needs to be determined. Fifty HCCs were examined with the aid of 59 microsatellite markers distributed throughout both arms of chromosome 1. To detect allelic gain effectively, the cutoff value of the allelic imbalance index was set at 0.70. Alleles showing imbalance were subjected to multiplex PCR, using a retained allele as an internal control, to determine whether the imbalance was the result of chromosomal gain or loss. The SRO of the gains was defined as D1S2878–D1S2619 (1q23.–q25.3, 16.9 Mb), which involved 36 cases (72%). Gains in the number of copies of certain oncogenes within this region seemed to be critical for the pathogenesis of HCC. In contrast, the centromeric breakpoints of these gains varied, but they tended to occur mainly in the pericentromeric region (26 of 50 cases, 52%). Rearrangement of specific genes associated with the gains is unlikely. On the other hand, the SRO of deletion was defined as D1S2893–D1S450 (1p36.32–p36.22, 5.1 Mb). Four known putative tumor‐suppressor genes (TP73, RIZ1, NBL1/DAN, and CDKN2C) were outside the SRO, suggesting the presence of other candidate genes with critical roles in hepatocarcinogenesis. © 2004 Wiley‐Liss, Inc.
On a policy of transferring public patients to private practice
Authors: González Paula 
Published: October 2004

AbstractWe consider an economy where public hospitals are capacity‐constrained, and we analyse the willingness of health authorities to reach agreements with private hospitals to have some of their patients treated there. When physicians are dual suppliers, we show that a problem of cream‐skimming arises and reduces the incentives of the health authority to undertake such a policy. We argue that the more dispersed are the severities of the patients, the greater the reduction in the incentives will be. We also show that, despite the patient selection problem, when the policy is implemented it is often the case that health authorities decide a more intensive transfer of patients to private practice. Copyright © 2004 John Wiley & Sons, Ltd.
Effects of socio‐economic status on mortality: separating the nearby from the farther away
Authors: Smits Jeroen , Keij‐Deerenberg Ingeborg , Westert Gert 
Published: October 2004

AbstractSocio‐economic status effects on total and cause‐specific mortality are studied using data on all 15.8 million inhabitants of the Netherlands in 1999. Two problems are addressed that often hamper this kind of research: the lack of reliable social status information at the individual level and the intermingling of individual and neighbourhood status effects. The first problem is dealt with by using socio‐economic status information of the very close environment of the detailed postcode areas (average 41 inhabitants) in which one is living and the second one by combining this information with such area information at the much larger level of neighbourhoods (1500 inhabitants) or boroughs (6600 inhabitants). Clear and independent effects of socio‐economic status at all three levels of aggregation are found on total mortality and for a majority of causes of death. In almost all cases, the effects are to the disadvantage of people living in the lowest status areas. The effects are generally strongest at the detailed postcode level and weakest at the borough level, suggesting greater importance of factors at the nearby or individual level than at the farther away level(s). Copyright © 2004 John Wiley & Sons, Ltd.
Outcome versus service based payments in health care: lessons from African traditional healers
Authors: Leonard Kenneth L. , Zivin Joshua Graff 
Published: October 2004

AbstractWe compare the more common physician compensation method of fee‐for‐service to the less common payment‐for‐outcomes method. This paper combines an investigation of the theoretical properties of both of these payment regimes with a unique data set from rural Cameroon in which patients can choose between outcome and service based payments. We show that consideration of the role of patient effort in the production of health leads to important differences in the performance of these contracts. Theory and empirical evidence show that when illnesses require (or are responsive to) large amounts of both patient and practitioner effort, outcome based payment schemes are superior to effort based schemes. The traditional healer – a practitioner who offers health services on an outcome‐contingent basis – is advanced as an important example of how patient effort can be better understood and tapped in health care. Copyright © 2004 John Wiley & Sons, Ltd.
The impact of glucose ingestion and gluco‐regulatory control on cognitive performance: a comparison of younger and middle aged adults
Authors: Meikle Andrew , Riby Leigh M. , Stollery Brian 
Published: October 2004

AbstractA great deal of research has been devoted to the issue of whether the ingestion of a glucose containing drink facilitates cognitive performance. However, it remains unclear exactly how age and individual differences in gluco‐regulatory control mediate a boost in cognitive functioning. The present study investigates these issues further. A repeated measures (25 g vs 50 g glucose vs placebo) counterbalanced, double‐blind design was used with 25 younger and middle‐aged adults. A battery of memory and non‐memory tasks was administered; including tests of episodic and semantic memory, attention and visuospatial functioning. Glucose ingestion largely facilitated performance on tasks with a memory component. Notably, task demands and age (young vs middle‐aged) contributed to the magnitude of memory enhancement. This finding suggests an age‐ and load‐specific benefit of glucose intake. In addition, evidence suggests greater facilitation in individuals with good glucose regulation. These data are discussed in relation to the idea that glucose specifically affects neural mechanisms supporting memory functioning (i.e. the hippocampus), which are known to decline in ageing. Importantly, the present investigation adds to the growing body of literature showing the utility of glucose supplementation as memory enhancers. Copyright © 2004 John Wiley & Sons, Ltd.
Enzymatic stabilization of gelatin‐based scaffolds
Authors: Broderick Emmett P. , O'Halloran Damien M. , Rochev Yury A. , Griffin Martin , Collighan Russell J. , Pandit Abhay S. 
Published: October 2004

AbstractThe definitive goal of this research is to develop protein‐based scaffolds for use in soft tissue regeneration, particularly in the field of dermal healing. The premise of this investigation was to characterize the mechanical properties of gelatin cross‐linked with microbial transglutaminase (mTGase) and to investigate the cytocompatibility of mTGase cross‐linked gelatin. Dynamic rheological analysis revealed a significant increase in the storage modulus and thermal stability of gelatin after cross‐linking with mTGase. Static, unconfined compression tests showed an increase in Young's modulus of gelatin gels after mTGase cross‐linking. A comparable increase in gel strength was observed with 0.03% mTGase and 0.25% glutaraldehyde cross‐linked gelatin gels. In vitro studies using 3T3 fibroblasts indicated cytotoxicity at a concentration of 0.05% mTGase after 72 h. However, no significant inhibition of cell proliferation was seen with cells grown on lower concentrations of mTGase cross‐linked gelatin substrates. The mechanical improvement and cytocompatibility of mTGase cross‐linked gelatin suggests mTGase has potential for use in stabilizing gelatin gels for tissue‐engineering applications. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 72B: 37–42, 2005
Mechanical resistance of a new biomaterial, ostrich pericardium, and a new method of joining tissues combining suturing and a biological adhesive
Authors: Páez José M. García , Sanmartin Antonio Carrera , Herrero Eduardo Jorge , Millán Isabel , Cordón Angeles , Rocha Aurora , Maestro María A. , Burgos Raul , Téllez Gabriel , Castillo‐Olivares José L. 
Published: October 2004

AbstractWe studied the mechanical behavior in response to tensile stress of samples of ostrich pericardium bonded with a cyanoacrylate glue or sewn with a rectangular, overlapping suture that was subsequently sealed with the same bioadhesive. Seventy‐two trials were performed in three series of 24 samples each: series AG, glued with an overlap of 1 cm2; series ASG, sewn with a rectangular, overlapping suture and sealed; and series AC, control samples that were left intact. The mean stress at rupture in series AG (glued) was 0.1 MPa, much lower than the working stress of a human valve leaflet, which is approximately 0.25 MPa. In the control series, this stress was 26.28 MPa. At rupture in series ASG (sutured/glued), the suture material was being subjected to a stress of 64.91 MPa, thus confirming the existence of an interaction between the suture and the shear stress exerted by the suture on the samples of pericardium. In series ASG, the mean value for the resistance to rupture when measured in machine kg was 8.83 kg, lower than but similar to that recorded in the control series AC (10.26 kg). The percentages of reversible deformation, or elongation, once the samples were torn were similar in series AC (19.15%) and ASG (21.93%). This phenomenon can only be explained by the damage to the collagen fibers in the area around the rupture, while other more distant regions work at a lower load within the elastic limit. We conclude that cyanocrylate adhesives alone are not suitable as bonding materials in cardiac bioprostheses. The results with the rectangular, overlapping suture, when subsequently sealed with an adhesive, can be considered good because, although this approach does not impede shear stress, it does maintain an excellent degree of resistance to rupture of the samples thus joined. We stress the need to take into account the concentration of the load in the design of bioprostheses. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 72B: 9–16, 2005
Effect of growth factors on proliferation and phenotypic differentiation of human fetal neural stem cells
Authors: Tarasenko Yevgeniya I. , Yu Yongjia , Jordan Paivi M. , Bottenstein Jane , Wu Ping 
Published: October 2004

AbstractHuman fetal neural stem cells (hNSCs) can be expanded in vitro by mitogens or growth factors, such as basic fibroblast growth factor (bFGF), epidermal growth factor (EGF), and/or leukemia inhibitory factor (LIF). Their effects on proliferation rate and differentiation pattern of hNSCs, however, have not been fully characterized. In this study, we cultured hNSCs in seven regimens, including bFGF, EGF, and LIF, either alone or in combinations. Cells were maintained as neurospheres in treatment media for various periods, up to six passages. A combination of bFGF, EGF, and LIF expanded hNSCs more efficiently than any other treatment as determined by counting total cell numbers using a trypan blue exclusion assay, a WST‐1 cell viability assay, and a bromodeoxyuridine incorporation flow cytometric analysis. Differentiation patterns of hNSCs expanded under different conditions were also analyzed. We reported previously that hNSCs primed in vitro with a combination of bFGF, heparin, and laminin (FHL) induced neuronal differentiation toward a cholinergic phenotype. In this study, we show that the FHL priming increases neuronal differentiation while decreasing astroglial generation in all treatment groups as determined by immunostaining. However, cells proliferated under different growth factor conditions do vary in their phenotypic differentiation patterns. Particularly, significant generation of cholinergic cells was observed only in hNSCs expanded with EGF/bFGF or EGF/bFGF/LIF, but not with other treatment regimens, even when they are exposed to the same priming procedure. Our results indicate that hNSCs are highly plastic, with their proliferation and differentiation potential dependent on different growth factor treatments. © 2004 Wiley‐Liss, Inc.
Kinetic model of sugar diffusion from sugar beet tissue treated by pulsed electric field
Authors: El‐Belghiti Kamal , Rabhi Zied , Vorobiev Eugene 
Published: October 2004

AbstractExtraction of sugar from sugar beet slices was studied following various pulsed electric field (PEF) treatments (intensities from 300 to 800 V cm−1 and number of pulses varying between 50 and 1000). Slices treated by PEF were immersed in water at ambient temperature at a liquid/solid ratio of 3. A significant increase in extraction yield was observed. This enhancement was due to permeabilisation of the cellular membrane and to the additional quantity of juice appearing on the surface of slices after PEF treatment being extracted rapidly by convection. The optimal conditions of PEF treatment were an intensity of 670 V cm−1 and 250 pulses. The extraction kinetics was studied on the basis of two approaches: Fick's diffusion equation and a two‐exponential kinetic model. The coefficient of diffusion was only slightly influenced by the conditions of PEF treatment. The two‐exponential model successfully described both the rapid and prolonged stages of extraction. By heating the solution at mild temperatures of 30–50 °C, the coefficient of diffusion was increased and the kinetics of extraction was enhanced. The quality of cellular juice obtained after PEF treatment was higher than that of juice obtained after thermal pretreatment at 75 °C. Copyright © 2004 Society of Chemical Industry
Monitoring oxidative quality of pork scratchings, peanuts, oatmeal and muesli by sensor array
Authors: Jensen Pernille N , Bertelsen Grete , van den Berg Frans 
Published: October 2004

AbstractA sensor array (electronic nose) was successfully applied for predicting the content of hexanal and other volatiles in different dry fat‐containing products, showing the potential of replacing time‐consuming traditional laboratory analysis by faster in‐process monitoring methods. Unfortunately, prediction of free radical content was not successful, making early prediction of oxidation by sensor array infeasible. Owing to the non‐specificity of the sensors, a generic model could not be generated even though a series of standards was shown to have a high correlation between hexanal concentration and individual or multiple sensor responses. PCA models of sensor array responses of eg pork scratchings revealed a clear separation of samples stored in the experimental factor light versus darkness. Copyright © 2004 Society of Chemical Industry