bluuebunny/crossref_metadata_2025_split huggingface dataset:
Integrated nonlinear optimization of bioprocesses via linear programming
Authors: Vera Julio , Torres Néstor V. , Moles Carmen G. , Banga Julio 
Published: April 2004

AbstractThe problem of integrated design and control of bioprocess plants is considered. A previously presented optimization approach for biochemical systems based on linear programming and modeling using the power law formalism (the Indirect Optimization Method, IOM) is extended. This method is enhanced in order to take into account both static and dynamic measures, and its use for the optimization of the integrated design of a bioprocess is illustrated. The chosen case study is a wastewater treatment plant, a bioprocess which typically presents controllability problems in real practice due to bad design methodologies. After defining an objective function reflecting both investment costs and “paracosts” (such as stability, flexibility, and controllability), a set of constraints determined by the system components and technical and economical factors is defined. A comparison of the results obtained with this new method and with a global optimization method reveals that, in both cases, significant improvements in both controllability and cost reduction are achieved, although the global method yields somewhat better improvements. The advantages and limitations of both methods are evaluated, concluding that the IOM, through its incorporation to a dynamic process simulator, can be successfully used to obtain, in a quick, inexpensive and interactive way, near‐optimal integrated designs for bioprocess plants.
Modeling of hydrogenation of maleic acid in a bubble‐column slurry reactor
Authors: Thakar Nakul N. , Jaganathan Rengaswamy , Chaudhari Raghunath V. , Mills Patrick L. 
Published: April 2004

AbstractA bubble‐column slurry‐reactor model has been developed for the hydrogenation of aqueous maleic acid (MAC) to tetrahydrofuran (THF). This particular reaction system has recent commercial relevance and represents a case where complex multistep catalytic hydrogenation reactions are conducted at high pressure (>15 MPa) and high temperature (>240°C). It also has additional complexities associated with the reaction chemistry, since the THF reaction product is volatile and the reaction is highly exothermic. The proposed model is derived using the mixing cell approach and incorporates the contributions of gas–liquid and liquid–solid mass transfer, intraparticle diffusion effects, product volatility, heat effects, and complex multistep reaction kinetics. The effect of gas and liquid velocities, catalyst loading, inlet maleic acid concentration, and temperature on the conversion, selectivity, temperature rise, and productivity of the desired products (THF and γ‐butyrolactone (GBL)) is also discussed. Since the reaction step involving the hydrogenation of GBL to THF is relatively slow, severe operating conditions are necessary to achieve high THF selectivity. The distribution pattern of THF in the gas and liquid phases is also discussed. The model proposed could be useful for simulation of existing pilot‐ or industrial‐scale reactors, as well as the design and scale‐up of new reactors for this particular reaction or one that has similar characteristics.
Beyond Thermodynamic Acidity: A Perspective on the Complex‐Induced Proximity Effect (CIPE) in Deprotonation Reactions
Authors: Whisler Marna C. , MacNeil Stephen , Snieckus Victor , Beak Peter 
Published: April 2004

AbstractThe concept of the complex‐induced proximity effect (CIPE) in deprotonations is helpful in elucidating the mechanisms involved in carbanion chemistry and in planning organic syntheses. In this Review, the consequences of complexation of organolithium bases to functional groups of the substrates before the proton‐transfer step are discussed. Experimental data from kinetic measurements and isotope‐labeling experiments as well as the results of calculations in many cases point to a prelithiation complex as a reaction intermediate. Some examples from natural products synthesis illustrate how this concept can be used to obtain intermediates in a regio‐ or stereoselective manner. Of particular interest is the functionalization of positions that are remote from the coordination group.
Compatibilization of polypropylene/nylon 6 blends with a polypropylene solid‐phase graft
Authors: Li Duxin , Jia Demin , Zhou Ping 
Published: April 2004

AbstractThe compatibilization of polypropylene (PP)/nylon 6 (PA6) blends with a new PP solid‐phase graft copolymer (gPP) was systematically studied. gPP improved the compatibility of PP/PA6 blends efficiently. Because of the reaction between the reactive groups of gPP and the NH2 end groups of PA6, a PP‐g‐PA6 copolymer was formed as a compatibilizer in the vicinity of the interfaces during the melting extrusion of gPP and PA6. The tensile strength and impact strength of the compatibilized PP/PA6 blends obviously increased in comparison with those of the PP/PA6 mechanical blends, and the amount of gPP and the content of the third monomer during the preparation of gPP affected the mechanical properties of the compatibilized blends. Scanning electron microscopy and transmission electron microscopy indicated that the particle sizes of the dispersed phases of the compatibilized PP/PA6 blends became smaller and that the interfaces became more indistinct in comparison with the mechanical blends. The microcrystal size of PA6 and the crystallinity of the two components of the PP/PA6 blends decreased after compatibilization with gPP. The compatibilized PP/PA6 blends possessed higher pseudoplasticity, melt viscosity, and flow activation energy. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 420–427, 2004
Factorial experimental design for grafting of vinyl monomers onto natural rubber latex
Authors: Arayapranee W. , Rempel G. L. 
Published: April 2004

AbstractGraft copolymerization of styrene (St) and methyl methacrylate (MMA) in the presence of natural rubber latex using cumene hydroperoxide/tetraethylenepentamine redox initiator system was prepared at various process variables. The synthesized graft copolymers were purified and then characterized by Fourier transformed infrared spectroscopy analysis. A full 24 factorial experimental design was applied to study the effect of various process variables on grafting efficiency. The following four independent variables considered to be mainly affecting the grafting efficiency were reaction temperature, rubber‐to‐monomer ratio, St‐to‐MMA ratio, and initiator amount used in the secondary polymerization. It was shown in this study that the reaction temperature significantly influenced the grafting efficiency, increasing as the temperature was increased. The amount of grafting increased with increasing rubber‐to‐monomer ratio and St‐to‐MMA ratio, whereas the amount of grafting decreased with increasing amount of initiator. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 455–463, 2004
Effect of polymer density on polyethylene hollow fiber membrane formation via thermally induced phase separation
Authors: Matsuyama Hideto , Hayashi Kentarou , Maki Taisuke , Teramoto Masaaki , Kubota Noboru 
Published: April 2004

AbstractMicroporous high‐density polyethylene (HDPE) and low‐density polyethylene (LDPE) hollow fiber membranes were prepared from polyethylene–diisodecyl phthalate solution via thermally induced phase separation. Effect of the polyethylene density on the membrane structure and performance was investigated. The HDPE membrane showed about five times higher water permeability than the LDPE membrane because it had the larger pore and the higher porosity at the outer membrane surface. The formation of the larger pore was owing to both the initial larger structure formed by spinodal decomposition and the suppression of the diluent evaporation from the outer membrane surface due to the higher solution viscosity. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 471–474, 2004
Metabolism of eupatilin in rats using liquid chromatography/electrospray mass spectrometry
Authors: Ji Hye Young , Lee Hye Won , Shim Hyun Joo , Kim Soon Hoe , Kim Won Bae , Lee Hye Suk 
Published: April 2004

AbstractEupatilin (5,7‐dihydroxy‐3′,4′,6‐trimethoxyﬂavone) is an active ingredient of an ethanol extract of Artemisia asiatica (DA‐9601) that is used in the treatment of gastritis. In vitro and in vivo metabolism of eupatilin in the rats has been studied by LC‐electrospray mass spectrometry. Rat liver microsomal incubation of eupatilin in the presence of NADPH and UDPGA resulted in the formation of four metabolites (M1–M4). M1, M2, M3 and M4 were tentatively identiﬁed as 3′‐ or 4′‐O‐demethyl‐eupatilin glucuronide, eupatilin glucuronide, 6‐O‐demethyleupatilin and 3′‐ or 4′‐O‐demethyl‐eupatilin, respectively. Those metabolites from in vitro study were also characterized in bile, plasma or urine samples after an intravenous administration of eupatilin to rats. In rat bile, plasma and urine samples, eupatilin glucuronide (M2) was a major metabolite, whereas M3, M4 and M4 glucuronide (M1) were the minor metabolites. Copyright © 2004 John Wiley & Sons, Ltd.
Simultaneous determination of matrine, sophoridine and oxymatrine in Sophora Flavescens Ait. by high performance liquid chromatography
Authors: Li Ke , Wang Huajuan 
Published: April 2004

AbstractFollowing a detailed study, a reversed‐phase high performance liquid chromatographic method (HPLC) has been developed and validated for analysis of three bioactive alkaloids, matrine, sophoridine and oxymatrine, in Sophora ﬂavescens Ait. HPLC separation of the alkaloids was performed on a Kromasil C18 column and detected by ultraviolet absorbance at 208 nm. The column temperature was maintained at 40°C. A mobile phase composed of 0.01 mol/L KH2PO4 buffer–methanol–triethylamine in the ratios 94:6:0.01 (v/v) was found to be the most suitable for this separation at a ﬂow‐rate of 1.0 mL/min and enabled the baseline separation of the three analytes free from interferences with isocratic elution. The analysis time was 24 min per injection. The calibration was linear in the range of 0.2–120.0 µg/mL for matrine, 0.2–115.2 µg/mL for sophoridine and 0.2–110.4 µg/mL for oxymatrine, respectively. For assaying Sophora Flavescens Ait. samples, the relative standard deviations were 2.0% for matrine, 2.8% for sophoridine and 1.8% for oxymatrine analysis. The average recoveries of matrine, sophoridine and oxymatrine were 93.9, 95.3 and 93.5% for the Sophora ﬂavescens Ait. samples, respectively. The method has been successfully applied to the simultaneous determination of matrine, sophoridine and oxymatrine in Sophora Flavescens Ait. samples collected in different habitats. Copyright © 2003 John Wiley & Sons, Ltd.
Effects of protein kinase C on M‐phase promoting factor in early development of fertilized mouse eggs
Authors: Yu Bing‐zhi , Zheng Jie , Yu Ai‐ming , Shi Xiu‐yan , Liu Ying , Wu Di‐di , Fu Wei , Yang Jianing 
Published: April 2004

AbstractThe mechanism of development of mouse fertilized eggs from the one‐cell stage to the two‐cell stage remains unclear to date. In the present study, we have evaluated protein kinase C (PKC) and M‐phase promoting factor (MPF) kinase activity in fertilized mouse eggs treated with a PKC modulator. PKC and MPF activity have similar activity. The two subunits of MPF, p34cdc2 and cyclin B, were shown to be included in the substrates phosphorylated by PKC in fertilized mouse eggs, while PKC modulator affected the electrophoretic mobility shift of cdc2 and cdc25C by dephosphorylation and phosphorylation. These results clearly indicate that PKC may affect the progression of the cell cycle through post‐translational modification of MPF activity. Copyright © 2004 John Wiley & Sons, Ltd.
Genetic instability of RBM5/LUCA‐15/H37 in MCF‐7 breast carcinoma sublines may affect susceptibility to apoptosis
Authors: Rintala‐Maki Nina D. , Abrasonis Virginia , Burd Maureen , Sutherland Leslie C. 
Published: April 2004

AbstractThe MCF‐7 human breast carcinoma cell line is widely used as a model system by breast cancer researchers and cell bio logists investigating apoptosis. Since its establishment 30 years ago, from a patient with metastatic breast cancer, the original MCF‐7 cell population has undergone genetic drift to such an extent that numerous genetically diverse sublines now exist. For instance, it has been reported that MCF‐7 cells have lost the region 3p21.3, to which the apoptosis regulatory protein and putative tumour suppressor LUCA‐15 (also called RBM5 and H37) maps; however, LUCA‐15 has been cloned from MCF‐7 cells, and LUCA‐15 expression analyses have been conducted using MCF‐7 cells. To address this discrepancy, we character ized three MCF‐7 sublines by Western blot, RT‐PCR and finally genomic PCR analysis, and determined that one of the three had lost the LUCA‐15 gene. Interestingly, loss of LUCA‐15 was positively correlated with decreased susceptibility to the death‐inducing ligand TNF‐α. Subsequent overexpression of exogenous LUCA‐15 was shown to enhance TNF‐α‐mediated apoptosis, suggesting that LUCA‐15 may play a role in regulating the susceptibility of breast cancer cells to drug‐induced apoptosis. These results not only reinforce the necessity of MCF‐7 subline characterization, but provide the first evidence of an apoptotic modulatory role for LUCA‐15 in a non‐T cell line. Copyright © 2004 John Wiley & Sons, Ltd.
Anion Complexation by Glycocluster Thioureamethyl Cavitands: Novel ESI‐MS‐Based Methods for the Determination of Ka Values
Authors: Oshovsky Gennady V. , Verboom Willem , Fokkens Roel H. , Reinhoudt David N. 
Published: April 2004

AbstractA series of saccharide‐thiourea functionalized cavitands was prepared in good yields (72–86 %) by reaction of a tetrakis(aminomethyl) cavitand with the thiocyanate derivatives of acetylated glucose, galactose, and cellobiose. The anion complexation behavior of the acetylated and deacetylated glycocluster thioureamethyl cavitands was studied with electrospray ionization mass spectrometry (ESI‐MS) in acetonitrile and in a 1:1 acetonitrile/water mixture, respectively. All compounds show a preference for Cl−. A linear relationship was found between the square root of the intensity and the concentration of the formed host–guest complex. Based on this relationship, novel methods have been developed to determine Ka values, by means of direct titration and competition experiments.
Psychological adjustment and sleep quality in a randomized trial of the effects of a Tibetan yoga intervention in patients with lymphoma
Authors: Cohen Lorenzo , Warneke Carla , Fouladi Rachel T. , Rodriguez M. Alma , Chaoul‐Reich Alejandro 
Published: April 2004

AbstractBACKGROUNDResearch suggests that stress‐reduction programs tailored to the cancer setting help patients cope with the effects of treatment and improve their quality of life. Yoga, an ancient Eastern science, incorporates stress‐reduction techniques that include regulated breathing, visual imagery, and meditation as well as various postures. The authors examined the effects of the Tibetan yoga (TY) practices of Tsa lung and Trul khor, which incorporate controlled breathing and visualization, mindfulness techniques, and low‐impact postures in patients with lymphoma.METHODSThirty‐nine patients with lymphoma who were undergoing treatment or who had concluded treatment within the past 12 months were assigned to a TY group or to a wait‐list control group. Patients in the TY group participated in 7 weekly yoga sessions, and patients in the wait‐list control group were free to participate in the TY program after the 3‐month follow‐up assessment.RESULTSEighty nine percent of TY participants completed at least 2–3 three yoga sessions, and 58% completed at least 5 sessions. Patients in the TY group reported significantly lower sleep disturbance scores during follow‐up compared with patients in the wait‐list control group (5.8 vs. 8.1; P < 0.004). This included better subjective sleep quality (P < 0.02), faster sleep latency (P < 0.01), longer sleep duration (P < 0.03), and less use of sleep medications (P < 0.02). There were no significant differences between groups in terms of intrusion or avoidance, state anxiety, depression, or fatigue.CONCLUSIONSThe participation rates suggested that a TY program is feasible for patients with cancer and that such a program significantly improves sleep‐related outcomes. However, there were no significant differences between groups for the other outcomes. Cancer 2004. © 2004 American Cancer Society.
Low‐dose weekly paclitaxel for recurrent or refractory aggressive non‐Hodgkin lymphoma
Authors: Rizzieri David A. , Sand Gregory J. , McGaughey Dean , Moore Joseph O. , DeCastro Carlos , Chao Nelson J. , Vredenburgh James J. , Gasparetto Cristina , Long Gwynn D. , Anderson Elizabeth , Foster Tracy , Toaso Bonnie , Adams Donna , Niedzwiecki Donna , Gockerman Jon P. 
Published: April 2004

AbstractBACKGROUNDMany patients with recurrent, intermediate or high‐grade non‐Hodgkin lymphoma (NHL) may not respond to or are not candidates for aggressive salvage chemotherapy. Effective, less toxic regimens are needed. Although high‐dose taxanes have not been reported to be very effective for the treatment of lymphoma, different delivery rates may allow for different mechanisms of action to be manifest and result in a different toxicity profile and response rate. The current study tested this hypothesis by using low‐dose, weekly paclitaxel in patients with recurrent or refractory NHL.METHODSAdults age > 18 years with refractory or recurrent, aggressive NHL who were not considered curable with standard high‐dose therapy received paclitaxel at a dose of 80 mg/m2 weekly for 5 weeks for 2 cycles.RESULTSThirty‐four patients with refractory NHL and 4 patients with recurrent disease were treated. Approximately 45% of the patients had achieved a prior disease remission. The median number of prior regimens received was 3, 74% of the patients had an International Prognostic Index of ≥ 3 at the time of study entry, and 29% had failed high‐dose therapy with autologous hematopoietic support. Only one patient encountered severe toxicity (sepsis). Myelosuppression was reported to occur in approximately 20% of patients. A total of 10 patients (26%) achieved a complete disease response and 4 patients (11%) achieved a partial response.CONCLUSIONSIn the current study, low‐dose, weekly paclitaxel therapy was found to provide a well tolerated and less toxic approach to the treatment of refractory NHL, with encouraging responses noted in heavily pretreated patients. However, evaluation in patients with an earlier stage of disease is warranted. Cancer 2004. © 2004 American Cancer Society.
High‐dose intravenous methotrexate followed by autologous stem cell transplantation as a potentially effective therapy for neurolymphomatosis
Authors: Ghobrial Irene M. , Buadi Francis , Spinner Robert J. , Colgan Joseph P. , Wolanskyj Alexandra P. , Dyck P. James , Witzig Thomas E. , Micallef Ivana N. , O'Neill Brian Patrick 
Published: April 2004

AbstractBACKGROUNDNeurolymphomatosis (NL) is a rare neurologic manifestation of systemic lymphoma characterized by lymphomatous infiltration of the peripheral nervous system. The diagnosis of NL is difficult and requires a multidisciplinary approach for obtaining an adequate biopsy specimen of the suspected nerve. The prognosis of patients with NL has been poor because adequate penetration of chemotherapy into the nervous system is difficult.METHODSThe authors presented the case of a 37‐year‐old man who was treated for Ann Arbor Stage IVB diffuse large B‐cell lymphoma. The patient developed disease recurrence in the sciatic nerve without systemic involvement.RESULTSThe patient achieved a clinical response after receipt of high‐dose intravenous methotrexate followed by high‐dose chemotherapy and autologous stem cell transplant.CONCLUSIONSThe authors reported this case to highlight the effectiveness of this regimen in a rare and fatal disorder. In the current study they also reviewed the literature regarding the diagnosis, prognosis, and treatment of NL. Cancer 2004. © 2004 American Cancer Society.
On semiclassical (zero dispersion limit) solutions of the focusing nonlinear Schrödinger equation
Authors: Tovbis Alexander , Venakides Stephanos , Zhou Xin 
Published: April 2004

AbstractWe calculate the leading‐order term of the solution of the focusing nonlinear (cubic) Schrödinger equation (NLS) in the semiclassical limit for a certain one‐parameter family of initial conditions. This family contains both solitons and pure radiation. In the pure radiation case, our result is valid for all times t ≥ 0. We utilize the Riemann‐Hilbert problem formulation of the inverse scattering problem to obtain the leading‐order term of the solution. Error estimates are provided. © 2004 Wiley Periodicals, Inc.
Facial wiping in the rat fetus: Variation of chemosensory stimulus parameters
Authors: Brumley Michele R. , Robinson Scott R. 
Published: April 2004

AbstractFetal rats reliably express a facial wiping response to novel chemosensory stimuli. Previous research has examined facial wiping as an early form of motor coordination and as a behavioral indicator of sensory responsiveness. The present study examined how variation in stimulus parameters of lemon odor infusion (concentration, volume, and infusion time) affected the wiping response of E20 rat fetuses. Infusions of higher concentration or greater volume generally elicited wiping responses of greater duration and more strokes. Most facial wipes involved strokes by single forelimbs; however, bilaterally synchronous wiping was expressed only in bouts of at least seven wipes, and was facilitated by stimuli of moderate intensity. These findings suggest that the total number of wiping strokes or bout duration are well suited as measures of overall sensory responsiveness in the fetus and that chemosensory stimulus parameters exert a permissive influence on interlimb coordination during a bout of facial wiping. © 2004 Wiley Periodicals, Inc. Dev Psychobiol 44: 219–229, 2004.
Environmental enrichment and development of cage stereotypy in Orange‐winged Amazon parrots (Amazona amazonica)
Authors: Meehan C. L. , Garner J. P. , Mench J. A. 
Published: April 2004

AbstractStereotypies are abnormal repetitive behaviors that often develop in animals housed in impoverished environments. Stereotypy represents the interaction of several complex developmental phenomena. To characterize the temporal nature of stereotypy increase (escalation) and decrease (attenuation), we monitored changes in stereotypy performance in young Orange‐winged Amazon parrots reared either in barren cages or cages provided with enrichments designed to facilitate foraging and locomotion. Unenriched parrots developed significantly more stereotypy than enriched parrots, and the mean time to stereotypy onset and the rate and magnitude of stereotypy increase also differed between the two groups. We then provided enrichment to the birds that had been reared in the barren cages. Following a 4‐week delay, stereotypy was significantly reduced. These results show that stereotypy can be both prevented and reversed with appropriate environmental modification and illustrate how studying this behavior at many points over time can provide insights into its ontogeny. © 2004 Wiley Periodicals, Inc. Dev Psychobiol 44: 209–218, 2004.