bluuebunny/crossref_metadata_2025_split huggingface dataset:
Lipid factor (bVLF) from bovine vitreous body evokes in EGFR‐T17 cells a Ca2+‐dependent K+ current associated with inositol 1,4,5‐trisphosphate‐independent Ca2+ mobilization
Authors: Camiña Jesus P. , Diaz‐Rodriguez Esther , Harks Erik G.A. , Theuvenet Alexander P.R. , Ypey Dirk L. , Casanueva Felipe F. 
Published: February 2003

AbstractBovine vitreous lipid factor (bVLF) is a complex phospholipid isolated from bovine vitreous body with strong Ca2+‐mobilizing activity. In this study, the effects of bVLF on membrane potential were investigated in EGFR‐T17 fibroblasts with the whole‐cell patch clamp technique on monolayer cells, as well as with the fluorescent dye bis‐oxonol as membrane potential‐sensitive probe on monolayer and suspension cells. bVLF induced a transient hyperpolarization characterized by an initial peak and subsequent return to resting membrane potential levels within 1–2 min. The increase of [Ca2+]i was concomitant with an outward current responsible for the hyperpolarizing response. Results with: (a) high [K+]o media; (b) the monovalent cation ionophore gramicidin; and (c) substitution of K+ with Cs+ in the intracellular solution were consistent with the involvement of K+ channels. The bVLF‐induced hyperpolarization was blocked by the K+ channel blockers, quinine and tetraethylamonium chloride, and partially affected by 4‐aminopyridine. The calcium ionophore ionomycin caused a similar hyperpolarization as bVLF. When intracellular calcium was buffered by adding BAPTA to the pipette solution, bVLF‐activated outward current was prevented. Moreover, the hyperpolarization response was strongly reduced at low doses (3 nM) of specific Ca2+‐activated K+ channel blockers, charybdotoxin and iberiotoxin. Based on these observations we conclude that bVLF hyperpolarizes the cells via the activation of a Ca2+‐dependent K+ current. In addition, it was observed that bVLF did not have a significant effect on intercellular communication measured by a single patch‐electrode technique. Thus, membrane potential changes appeared to belong to the earliest cellular responses triggered by bVLF, and are closely associated with phosphatidic acid‐dependent [Ca2+]i mobilization. © 2003 Wiley‐Liss, Inc.
Mast cell‐mediated apoptosis of endothelial cells in vitro: A paracrine mechanism involving TNF‐α‐mediated down‐regulation of bcl‐2 expression
Authors: Lätti Soili , Leskinen Markus , Shiota Naotaka , Wang Yenfeng , Kovanen Petri T. , Lindstedt Ken A. 
Published: February 2003

AbstractDegranulated mast cells are present in the subendothelial space of eroded (de‐endothelialized) coronary atheromas. Upon degranulation, mast cells secrete into the surrounding tissue an array of preformed and newly synthesized mediators, including proapoptotic molecules, such as chymase and TNF‐α. In a co‐culture system involving rat serosal mast cells and rat cardiac (microvascular) endothelial cells, we could show, by means of competitive RT‐PCR, immunoblotting, immunocytochemistry, annexin staining, flow cytometry, and DNA‐laddering, that stimulation of mast cells with ensuing degranulation rapidly (within 30 min) down‐regulated the expression of both bcl‐2 mRNA and protein, with subsequent induction of apoptosis in the endothelial cells. The major effect of bcl‐2 down‐regulation resided in the exocytosed granule remnants, a minor effect also being present in the granule remnant‐free supernatant. No significant changes were observed in the expression levels of the pro‐apoptotic protein, bax. The mast cell‐mediated apoptotic effect was partially (70%) dependent on the presence of TNF‐α and involved the translocation of cytochrome C from mitochondria into cytoplasm. These results are the first to show that one of the cell types present in the atherosclerotic plaques, namely the mast cell, by releasing both granule‐remnant‐bound and soluble TNF‐α, may contribute to the erosion of atherosclerotic plaques by inducing apoptosis in adjacent endothelial cells. Published 2003 Wiley‐Liss, Inc.
Critical role of both p27KIP1and p21CIP1/WAF1 in the antiproliferative effect of ZD1839 (‘Iressa’), an epidermal growth factor receptor tyrosine kinase inhibitor, in head and neck squamous carcinoma cells
Authors: Di Gennaro Elena , Barbarino Marcella , Bruzzese Francesca , De Lorenzo Sonya , Caraglia Michele , Abbruzzese Alberto , Avallone Antonio , Comella Pasquale , Caponigro Francesco , Pepe Stefano , Budillon Alfredo 
Published: February 2003

AbstractHigh expression of the epidermal growth factor receptor (EGFR) has been implicated in the development of squamous‐cell carcinomas of head and neck (SCCHN). ZD1839 (‘Iressa’) is an orally active, selective EGFR‐TKI (EGFR‐tyrosine kinase inhibitor) that blocks signal transduction pathways implicated in proliferation and survival of cancer cells, and other host‐dependent processes promoting cancer growth. We have demonstrated that ZD1839 induces growth arrest in SCCHN cell lines by inhibiting EGFR‐mediated signaling. Cell cycle kinetic analysis demonstrated that ZD1839 induces a delay in cell cycle progression and a G1 arrest together with a partial G2/M block; this was associated with increased expression of both p27KIP1 and p21CIP1/WAF1 cyclin‐dependent kinase (CDK) inhibitors. The activity of CDK2, the main target of CIP/KIP CDK inhibitors, was reduced in a dose‐dependent fashion after 24 h of ZD1839 treatment and this effect correlated to the increased amount of p27KIP1 and p21CIP1/WAF1 proteins associated with CDK2‐cyclin‐E and CDK2‐cyclin‐A complexes. In addition, ZD1839‐induced growth inhibition was significantly reduced in cell transfectants expressing p27KIP1 or p21CIP1/WAF1 antisense constructs. Overall, these results as well as the timing of the effect of ZD1839 on G1 arrest and p27KIP1 and p21CIP1/WAF1 upregulation, suggest a mechanistic connection between these events. © 2003 Wiley‐Liss, Inc.
Induction of globin mRNA expression by interleukin‐3 in a stem cell factor‐dependent SV‐40 T‐antigen‐immortalized multipotent hematopoietic cell line
Authors: Cairns Linda , Cirò Marco , Minuzzo Mario , Morlé François , Starck Joëlle , Ottolenghi Sergio , Ronchi Antonella 
Published: February 2003

AbstractErythropoiesis requires the stepwise action on immature progenitors of several growth factors, including stem cell factor (SCF), interleukin 3 (IL‐3), and erythropoietin (Epo). Epo is required to sustain proliferation and survival of committed progenitors and might further modulate the level of expression of several erythroid genes, including globin genes. Here we report a new SCF‐dependent immortalized mouse progenitor cell line (GATA‐1 ts SCF) that can also grow in either Epo or IL‐3 as the sole growth factor. When grown in SCF, these cells show an “open” chromatin structure of the β‐globin LCR, but do not significantly express globin. However, Epo or IL‐3 induce globin expression and are required for its maintainance. This effect of IL‐3 is unexpected as IL‐3 was previously reported either to be unable to induce hemoglobinization, or even to antagonize it. This suggests that GATA‐1 ts SCF cells may have progressed to a stage in which globin genes are already poised for expression and only require signal(s) that can be elicited by either Epo or IL‐3. Through the use of inhibitors, we suggest that p38 may be one of the molecules modulating induction and maintenance of globin expression. © 2003 Wiley‐Liss, Inc.
Non‐selective membranes for separations
Authors: Cussler Edward L 
Published: February 2003

AbstractMembranes which give high fluxes without selectivities provide a large interfacial area between fluid phases which is independent of the normal constraints of loading and flooding. These membranes offer a largely unexplored route to separation process intensification. Three examples are given in the paper. First, studies of hollow fiber blood oxygenators show that flows which are only a few percent from uniform can reduce overall mass transfer by an order of magnitude. Second, flat sheet membrane evaporators promise the performance of a centrifugal evaporator at a fraction of that unit's cost. Third, distillation in hollow fibers means that the height of the transfer units can be smaller than 0.1 cm, indeed as small as desired.© 2003 Society of Chemical Industry
New internals for urea production reactors
Authors: Bozzano G , Dente M , Zardi F 
Published: February 2003

AbstractFluid dynamics and its influence on heat and mass transport rates in gas–liquid reactors is, in general, an important starting point for development of a process design. Improvements in the understanding of these aspects can be particularly fruitful in the case of urea reactors where the fluid‐dynamic patterns are complicated by the co‐current flow of two phases and the bubbling mode of the vapors. The analysis of such systems highlighted the non‐optimal design of existing reactors and led to the conception of new reactor internals. Several industrial applications demonstrate the ability of the new configuration to improve reactor efficiency. Both energy‐saving and production increases were obtained. This is a further demonstration that even mature technologies can be improved, leading not only to economic advantages, but also to a reduction in their environmental impact.© 2003 Society of Chemical Industry
Gas–liquid mass transfer in a 15 cm diameter reciprocating plate column
Authors: Rama Rao N V , Baird M H I 
Published: February 2003

AbstractData are reported on the absorption of oxygen by water under countercurrent flow conditions, in a 15 cm diameter reciprocating plate bubble column. Amplitude (half stroke) is set at 12.7 mm and reciprocation frequencies up to 5 Hz have been employed. Five different types of plate have been compared; two of the types are multiperforated and three of the types are ‘donut’ plates with a single central hole. When the comparison is made in terms of the volumetric mass transfer coefficient (kla) and power input per unit mass, the best of the five types of plate is a multiperforated plate with small holes of diameter 6.35 mm.© 2003 Society of Chemical Industry
Ozone oxidation in a rotating packed bed
Authors: Lin Chia‐Chang , Liu Wen‐Tzong 
Published: February 2003

AbstractThe feasibility of applying a novel rotating packed bed to the ozone oxidation process is investigated. Ozone oxidation experiments were conducted to examine how various operating variables affect the decolorization of dyes in aqueous solutions system. Rotor speeds ranged from 380 to 1748 rpm, providing 10∼202 equivalent gravitational force. Experimental results indicate that the centrifugal force positively affects the decolorization efficiency. Furthermore, it is shown that owing to its low ozone mass transfer resistance, a rotating packed bed can be used to increase the efficiency of the ozone oxidation process. Our results further demonstrate that the decolorization efficiency increases with either an decreasing initial dye concentration or liquid flow rate.© 2003 Society of Chemical Industry
Intensification of random packing via CFD simulation, PIV measurement and traditional experiments
Authors: Fei W Y , Wang Y D , Song X Y , Yin Y D , Sun L Y 
Published: February 2003

AbstractIt is shown from CFD simulation and particle image velocimetry (PIV) measurements that the flow field around ring packing is impacted by their height/diameter ratio and inclination. The results indicate that it is better to decrease the height/diameter ratio of ring packing to intensify the separation processes in the packing bed. Based on a systematic study, a new Plum Flower Mini Ring (PFMR) was developed to meet the demands of separation column intensification.A comparison of the PFMR, Pall Ring and Intalox Saddle in a 600 mm diameter column with an air–oxygen–water system over a wide range of liquid loads is presented. It was shown from the experiments that the PFMR had a much lower pressure drop, much larger throughput and better mass transfer efficiency than Pall Rings and Intalox Saddles.© 2003 Society of Chemical Industry
Physical modelling for airlift loop tanks
Authors: Trilleros J A , Díaz R , Redondo P 
Published: February 2003

AbstractAirlift loop tanks (ALT) are used in a many industrial applications where close contact among the different phases is essential. We can find such examples in the chemical, petrochemical, biochemical and minerals processing industries. The ALT principle is based on creating a zone within the tank through which gas rises. In this way a difference in density is obtained between the gas–liquid–solid riser zone and the liquid–solid downcomer zone; this density difference induces circulation of the liquid and solid phases through both zones. When the gas velocity is increased, gas bubbles inside the liquid phase are also transported into the downcomer. This circulation creates a good mixture of all three phases and efficient suspension of solid in the liquid. A main parameter that characterizes ALT operation is the circulation velocity, which can be quantified by the riser superficial liquid velocity. This parameter is a function of the operational adjustable variables such as gas flow‐rate, liquid and solid densities, fractional holdup, solid size and tank geometry. The following variables were determined by experimental work: pressure losses in ALT, superficial solid velocity in riser and downcomer, superficial liquid velocity in riser and solid holup in riser. Finally the relationship between these variables was established.© 2003 Society of Chemical Industry
Modelling of film flow over a spinning disk
Authors: Sisoev Grigori M , Matar Omar K , Lawrence Christopher J 
Published: February 2003

AbstractFilm flows over a spinning disk are applied to intensify heat and mass transfer processes, which need large contact surfaces between a liquid and surrounding gas. An inherent property of this flow is the formation of waves, whose amplitude may have the same scale as the film thickness. Experimental observations indicate a strong dependence of heat and mass transfer processes on these surface structures, especially in the case of large amplitude waves. This paper reports mathematical modelling of this flow.© 2003 Society of Chemical Industry
Generating innovative process designs using limited data
Authors: Sharratt Paul N , Wall Kevin , Borland John N 
Published: February 2003

AbstractKey constraints in process innovation are the time and cost spent obtaining data to identify and verify novel processes. Businesses are under increasing pressure to deliver products in shorter times; pressure which restricts and often prevents access to innovative and intensive processing options. The Britest project has identified key decisions in process design and the associated minimum data requirements. These involve identification and manipulation of the relevant rate processes and consideration of the phases of matter that are (or could be) present. By use of qualitative and semi‐quantitative reasoning it is possible to produce a range of possible process options very early in design. This is particularly useful in the low‐tonnage chemicals sectors (fine and effect chemicals) where process design is primarily an empirical activity. It also helps to deal rationally with the complex chemistry prevalent in those industries. The early identification of options allows timely development of experimental programmes to evaluate the options. An illustrative example based on a diazotisation and the associated decomposition reaction is presented.© 2003 Society of Chemical Industry
Study of the preparation and composition of the metallic function for the selective hydrogenation of CO2 to gasoline over bifunctional catalysts
Authors: Ereña Javier , Arandes José M , Garoña Raúl , Gayubo Ana G , Bilbao Javier 
Published: February 2003

AbstractBifunctional catalysts for the transformation of carbon dioxide and hydrogen into gasoline have been prepared by conventional and novel processes and characterized by measurement of BET surface area and volume and distribution of pores, and by X‐ray diffraction, FTIR spectroscopy and X‐ray fluorescence. The effects of the preparation conditions and of the atomic ratios between the metals on the structure and on the properties of the catalysts were studied.© 2003 Society of Chemical Industry
Combustion of chlorinated hydrocarbons in catalyst‐coated sintered metal fleece reactors
Authors: Everaert K , Mathieu M , Baeyens J , Vansant E 
Published: February 2003

AbstractIncinerators emit chlorinated hydrocarbons, such as polychlorinated benzenes (PCBz) and phenols (PCPh), polychlorinated biphenyls (PCB) and polychlorinated dibenzodioxins and furans (PCDD/F), as very dilute streams. High temperatures (>1000 °C) are required in traditional oxidizers. From an energy‐saving perspective and to avoid de novo synthesis of PCDD/F, exhaust gas clean‐up must be performed at low temperatures (250–350 °C). Catalytic combustion can be applied in this temperature range and different reactor layouts are used (eg monoliths, honeycomb). The present investigation uses a novel catalyst‐coated sintered metal fleece. Thin metal fibers are sintered (non‐woven) to fleece of various thickness, structure and porosity. V–Ti–W catalysts are examined. The paper will briefly review the catalyst coating method suitable to provide a structured fleece reactor with adequate characteristics. Experiments were carried out in the temperature range of 260–340 °C with various hydrocarbons injected in a carrier air stream. The experimental investigations demonstrated: (i) that the conversion of the hydrocarbons (volatile organic compounds, VOC) is independent of the oxygen concentration, corresponding to a zero‐order dependence of the reaction rate; (ii) that the conversion of the hydrocarbons is a first‐order reaction in the VOC; (iii) that the oxidation of the VOC proceeds to a greater extent with increasing temperature, with chlorine substitution enhancing the reactivity, and (iv) that the reaction rate constant follows an Arrhenius‐dependence with activation energies between 37.3 and 58.4 kJ mol−1. An assessment of the results leads to a model expression with kinetic reaction control. This model can be used in a scale‐up strategy.© 2003 Society of Chemical Industry
A novel separation technique – gas carrying evaporation: theory and application
Authors: Ma Feng , Yu Zhijia , Wang Jun , Ding Jie , Xu Weiqin , Shen Ziqiu 
Published: February 2003

AbstractTo avoid or mitigate scaling or thermal deterioration in the process of evaporation a novel process – Gas Carrying Evaporation (GCE) has been developed with the concept of an ‘interfacial vaporization heat sink’. In the GCE process, an inert gas was introduced at the bottom of vertical heating tubes. Due to the effect of the ‘heat sink’, the temperature of the heating wall is lowered, nucleate boiling on the heating wall is suppressed, and solvent vaporization mainly takes place at the gas–liquid interface in the two‐phase flow bulk. Therefore, both thermal deterioration and scaling on the heating wall are avoided or mitigated, and the heat transfer is greatly enhanced. The process of GCE has been used in several industries for the evaporation of thermally sensitive and easily depositing solutions. In this paper, the development of GCE, the theory of heat transfer augmentation by the interfacial vaporization heat sink, and the characteristics and applications of GCE are described and discussed.© 2003 Society of Chemical Industry
Modeling of electrostatic spray in a venturi scrubber
Authors: Yang H T , Viswanathan S , Balachandran W , Ray M B 
Published: February 2003

AbstractThis paper summarizes the results of an investigation into the distribution of the droplets produced by electrostatic nozzles inside a Pease–Anthony venturi scrubber. The model simulates the flux distribution of charged droplets injected from an electrostatic nozzle in the scrubber under the combined influence of hydrodynamic and electric fields. The effects of operating parameters, such as gas velocity, diameter of the scrubbing droplets, charge‐to‐mass ratio and liquid‐to‐gas ratio, on the flux distribution of the water droplets in the throat of the scrubber are also investigated. The model takes into account initial liquid momentum, electric, hydrodynamic and gravitational forces, and eddy diffusion. The flux distribution of the scrubbing liquid in the presence of an electric field is much improved over a conventional scrubber, and the effect increases with the increase in charge‐to‐mass ratio. However, the effect of an electric field on the droplet flow pattern for small drops in a strong hydrodynamic field is negligible. Simulated results are in good agreement with the experimental data obtained in the laboratory.© 2003 Society of Chemical Industry
Segregation of binary mixture of particles in a bladed mixer
Authors: Zhou Y C , Yu A B , Bridgwater J 
Published: February 2003

AbstractThis paper presents a numerical study of the flow and segregation of particles over flat blades in a vertical cylindrical mixer by means of a modified discrete element method. Simulations are conducted using a binary mixture of spheres, where the blade's rotating speed, particle size, volume fraction and particle density are the variables considered. Similar flow features are found for all the cases considered: particles rise to form a heap in front of a blade and then either flow downward on the bed surface over the blade or to the base of the heap to rejoin the flow toward the blade, and there is a recirculating zone in front of the blade. However, different types of mixing behaviour can be observed. Particles with large size or light density are mainly in the top layer of the mixing bed, while small and heavy particles remain in the bottom of the mixing bed and in front of the blades. The segregation pattern resulting from size difference is not the same as that resulting from density difference. The force evolution in these two binary systems also differs, although at the initial stage large/light particles always receive a relatively larger vertical force than small/heavy particles, leading to segregation that can be maintained at the later stage. Decreasing the size or density difference promotes the mixing performance. Changing the blade speed affects the mixing kinetics but not the mixing quality.© 2003 Society of Chemical Industry
Modelling the kinetics of lipase‐catalysed oil hydrolysis in an electrically enhanced liquid–liquid system
Authors: Jones E , Weatherley L R 
Published: February 2003

AbstractThis study focussed on the use of high voltage electrostatic fields to spray solutions of the non‐specific lipase Candida rugosa into high oleate sunflower oil and to determine rates of hydrolysis. Significant increases in reaction rate are reported. The kinetics were analysed using a modified reaction model for enzymatic reactions at free liquid interfaces. Similar data for hydrolysis rate within dispersions formed by mechanical agitation in a recycle reactor were similarly measured and interpreted. In both cases good agreement was obtained between the experimental measurements and the predicted results.© 2003 Society of Chemical Industry