bluuebunny/crossref_metadata_2025_split huggingface dataset:
Error propagation from prime variables into specific rates and metabolic fluxes for mammalian cells in perfusion culture
Authors: Goudar Chetan T. , Biener Richard , Konstantinov Konstantin B. , Piret James M. 
Published: June 2009

AbstractError propagation from prime variables into specific rates and metabolic fluxes was quantified for high‐concentration CHO cell perfusion cultivation. Prime variable errors were first determined from repeated measurements and ranged from 4.8 to 12.2%. Errors in nutrient uptake and metabolite/product formation rates for 5–15% error in prime variables ranged from 8–22%. The specific growth rate, however, was characterized by higher uncertainty as 15% errors in the bioreactor and harvest cell concentration resulted in 37.8% error. Metabolic fluxes were estimated for 12 experimental conditions, each of 10 day duration, during 120‐day perfusion cultivation and were used to determine error propagation from specific rates into metabolic fluxes. Errors of the greater metabolic fluxes (those related to glycolysis, lactate production, TCA cycle and oxidative phosphorylation) were similar in magnitude to those of the related greater specific rates (glucose, lactate, oxygen and CO2 rates) and were insensitive to errors of the lesser specific rates (amino acid catabolism and biosynthesis rates). Errors of the lesser metabolic fluxes (those related to amino acid metabolism), however, were extremely sensitive to errors of the greater specific rates to the extent that they were no longer representative of cellular metabolism and were much less affected by errors in the lesser specific rates. We show that the relationship between specific rate and metabolic flux error could be accurately described by normalized sensitivity coefficients, which were readily calculated once metabolic fluxes were estimated. Their ease of calculation, along with their ability to accurately describe the specific rate‐metabolic flux error relationship, makes them a necessary component of metabolic flux analysis. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009
Synergistic coordination of polyethylene glycol with ClpB/DnaKJE bichaperone for refolding of heat‐denatured malate dehydrogenase
Authors: Nian Rui , Kim Duck Sang , Tan Lihan , Kim Chan‐Wha , Choe Woo‐Seok 
Published: June 2009

AbstractThe use of polyethylene glycol (PEG) as a refolding additive to a refolding cocktail comprising the molecular bichaperone ClpB and DnaKJE significantly enhances chaperone‐mediated refolding of heat‐denatured malate dehydrogenase (MDH). The critical factor to affect the refolding yield is the time point of introducing PEG to the refolding cocktail. The refolding efficiency reached approximately 90% only when PEG was added at the beginning of refolding reaction. The synergistic coordination of an inexpensive refolding additive PEG with the ClpB/DnaKJE bichaperone system may provide an economical route to further enhance the efficacy of ClpB/DnaKJE refolding cocktail approach, facilitating its implementation in large‐scale refolding processes. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009
Emergent percutaneous coronary intervention for resuscitated victims of out‐of‐hospital cardiac arrest
Authors: Kern Karl B. , Rahman Ossama 
Published: June 2009

AbstractLong‐term survival rates even after successful resuscitation from out‐of‐hospital cardiac arrest are dismal. Most of those initially resuscitated expired during their hospitalization. Recent reports have suggested that a more aggressive approach to postresuscitation care is the key to better outcome. Waiting for the evidence of neurological recovery before acting can result in missed opportunity to improve such recovery. Immediate induction of mild therapeutic hypothermia for all resuscitated victims who remain comatose offers the best hope for neurological recovery. Numerous reports suggest that early coronary angiography and PCI also improve outcome among those resuscitated from cardiac arrest whose postresuscitation ECG show evidence of ST elevation myocardial infarctions. Most promising is combining these two postresuscitation therapies, namely immediate induction of hypothermia and early coronary angiography and PCI. Combining these therapies has resulted in long‐term survival rates of 70% with more than 80% of all such survivors neurologically functional. Even those without ST elevation on their postresuscitation ECG can greatly benefit from timely induction of hypothermia and early angiography/PCI. © 2009 Wiley‐Liss, Inc.
Transhepatic closure of patent foramen ovale
Authors: Jolly Neeraj , Dhar Gaurav , Amin Zahid 
Published: June 2009

AbstractTranshepatic right heart catheterization is an uncommon procedure for adult interventional cardiologists. We report its successful use for closure of a patent foramen ovale in an elderly patient without femoral vein access. Also described is a novel method of using a vascular plug to achieve hemostasis of the hepatic venous access site. © 2009 Wiley‐Liss, Inc.
Framework Breathing in the Vapour‐Phase Adsorption and Separation of Xylene Isomers with the Metal–Organic Framework MIL‐53
Authors: Finsy Vincent , Kirschhock Christine E. A. , Vedts Gill , Maes Michael , Alaerts Luc , De Vos Dirk E. , Baron Gino V. , Denayer Joeri F. M. 
Published: June 2009

AbstractVapour‐phase adsorption and separation of the C8 alkyl aromatic compounds p‐xylene, m‐xylene, o‐xylene, and ethylbenzene has been studied on the metal–organic framework MIL‐53. Adsorption and desorption isotherms of the pure components at 110 °C were determined using the gravimetric technique. The adsorption isotherms show two well‐defined steps and hysteresis, corresponding to the opening or breathing of the framework, as induced by the presence of the adsorbing molecules. In the first isotherm plateau, an adsorption capacity of about 18 wt % is observed. After the breathing phenomenon, the adsorption capacity increases to about 40 wt %. Breakthrough separation experiments with equimolar o‐xylene/ethylbenzene mixtures were performed at 110 °C with varying hydrocarbon pressures. The separation mechanism is related to the state of the pore structure, as dictated by framework breathing. At low pressure, below the “pore‐opening” pressure, MIL‐53 shows no preference for any isomer. At pressures high enough to induce pore opening, separation of the C8 alkyl aromatic isomers becomes possible and separation factors as high as 6.5 are observed. The separation at a high degree of pore filling in the open form is a result of differences in the packing modes of the C8 alkyl aromatic components in the pores of MIL‐53.
Synthesis of Amphiphilic [60]Fullerene [3:3]Hexakisadducts with Four Spherically Defined Addend Zones
Authors: Beuerle Florian , Hirsch Andreas 
Published: June 2009

AbstractNew [3:3]hexakisadducts 3, 6, and 7 have been synthesized by a stepwise addition of two tripodal malonate tethers to pristine [60]fullerene. For the first time, [3:3]hexakisadducts of two sets of asymmetrically substituted malonate addends could be prepared as single in/out isomers by following this synthetic protocol. Thereby, four spherically defined addend zones I–IV were created with various similar degrees of latitude on the fullerene sphere. Four amphiphilic [3:3]hexakisadducts 12, 14, 18, and 19 were prepared with different relative arrangements of both the hydrophilic and lipophilic moieties in the addend zones I/II and III/IV, respectively.
Selective Triplet‐State Formation during Charge Recombination in a Fullerene/Bodipy Molecular Dyad (Bodipy=Borondipyrromethene)
Authors: Ziessel Raymond , Allen Ben D. , Rewinska Dorota B. , Harriman Anthony 
Published: June 2009

AbstractA conformationally restricted molecular dyad has been synthesized and subjected to detailed photophysical examination. The dyad comprises a borondipyrromethene (Bodipy) dye covalently linked to a buckminsterfullerene C60 residue, and is equipped with hexadecyne units at the boron centre in order to assist solubility. The linkage consists of a diphenyltolane, attached at the meso position of the Bodipy core and through an N‐methylpyrrolidine ring at the C60 surface. Triplet states localised on the two terminals are essentially isoenergetic. Cyclic voltammetry indicates that light‐induced electron transfer from Bodipy to C60 is thermodynamically favourable and could compete with intramolecular energy transfer in the same direction. The driving force for light‐induced electron abstraction from Bodipy by the singlet excited state of C60 depends critically on the solvent polarity. Thus, in non‐polar solvents, light‐induced electron transfer is thermodynamically uphill, but fast excitation energy transfer occurs from Bodipy to C60 and is followed by intersystem crossing and subsequent equilibration of the two triplet excited states. Moving to a polar solvent switches on light‐induced electron transfer. Now, in benzonitrile, the charge‐transfer state (CTS) is positioned slightly below the triplet levels, such that charge recombination restores the ground state. However, in CH2Cl2 or methyltetrahydrofuran, the CTS is slightly higher in energy than the triplet levels, and decays, in part, to form the triplet state localized on the C60 residue. This step is highly specific and does not result in direct formation of the triplet excited state localized on the Bodipy unit. Subsequent equilibration of the two triplets takes place on a relatively slow timescale.
New Blue‐Light‐Emitting Ultralong [Cd(L)(TeO3)] (L=polyamine) Organic–Inorganic Hybrid Nanofibre Bundles: Their Thermal Stability and Acidic Sensitivity
Authors: Yao Hong‐Bin , Li Xiao‐Bo , Yu Shu‐Hong 
Published: June 2009

AbstractA new type of blue‐light‐emitting ultralong [Cd(L)(TeO3)] (L=ethylenediamine, diethylenetriamine) nanofibre bundle has been synthesised under reflux in a mixed solvent media. Inorganic Cd(TeO3) layers are assumed to exist in the structures and are connected by the organic amine molecules through the coordination between nitrogen atoms and cadmium ions. The composition and formulae of these hybrid materials, based on the proposed structures, have been identified through element analysis (EA), thermal gravity analysis (TGA) and energy dispersive spectra (EDS). The thermal stabilities and optical properties of these nanofibre bundles have been investigated. Thermal decomposition of [Cd(en)(TeO3)] (en=ethylenediamine) and [Cd(DETA)(TeO3)] (DETA=diethylenetriamine) at 450 °C allowed the formation of a mixture of CdTe and Cd(TeO3) phases, and a pure CdTe phase, respectively. In addition, this new kind of hybrid bundle, which demonstrates blue emission, was found to be sensitive to acids, and the emission intensity is strongly dependent on the acidity of the solutions, implying that these hybrid nanofibre bundles could be potentially applied as acid sensors.
Synthesis and Structure–Activity Correlation Studies of Secondary‐ and Tertiary‐Amine‐Based Glutathione Peroxidase Mimics
Authors: Bhabak Krishna P. , Mugesh Govindasamy 
Published: June 2009

AbstractIn this study, a series of secondary‐ and tertiary‐amino‐substituted diaryl diselenides were synthesized and studied for their glutathione peroxidase (GPx) like antioxidant activities with H2O2, cumene hydroperoxide, or tBuOOH as substrates and with PhSH or glutathione (GSH) as thiol cosubstrates. This study reveals that replacement of the tert‐amino groups in benzylamine‐based diselenides by sec‐amino moieties drastically enhances the catalytic activities in both the aromatic thiol (PhSH) and GSH assay systems. Particularly, the N‐propyl‐ and N‐isopropylamino‐substituted diselenides are 8–18 times more active than the corresponding N,N‐dipropyl‐ and N,N‐diisopropylamine‐based compounds in all three peroxide systems when GSH is used as the thiol cosubstrate. Although the catalytic mechanism of sec‐amino‐substituted diselenides is similar to that of the tert‐amine‐based compounds, differences in the stability and reactivity of some of the key intermediates account for the differences in the GPx‐like activities. It is observed that the sec‐amino groups are better than the tert‐amino moieties for generating the catalytically active selenols. This is due to the absence of any significant thiol‐exchange reactions in the selenenyl sulfides derived from sec‐amine‐based diselenides. Furthermore, the seleninic acids (RSeO2H) derived from the sec‐amine‐based compounds are more stable toward further reactions with peroxides than their tert‐amine‐based analogues.
Structural Adaptability of Zinc Binding Sites: Different Structures in Partially, Fully, and Heavy‐Metal Loaded States
Authors: Heinz Uwe , Hemmingsen Lars , Kiefer Martin , Adolph Hans‐Werner 
Published: June 2009

AbstractThe present study demonstrates that both the nature (ZnII, CdII or HgII) and supply of metal ions determine whether zinc fingers fold into the well‐known, fully loaded structures or alternatively populate a variety of structural states under substoichiometric conditions. Metal‐bridged species are observed by perturbed angular correlation (PAC), EXAFS, UV spectroscopy, and stopped‐flow kinetics. Transitions between structural states as adaptive reactions to changed metal‐ion supply might represent intelligent system changes in zinc homeostasis, trafficking and signalling, and reflect features of heavy‐metal toxicity at the molecular level. Because the zinc fingers exist in structural states that are different from the metal‐free and fully loaded species, the prevailing view on metal‐mediated molecular regulation in terms of “on and off control” might be oversimplified.
N‐Heteroacenes
Authors: Bunz Uwe H. F. 
Published: June 2009

AbstractThe synthesis and the property evaluation of several large N‐heteroacenes are discussed. Issues of stability and aromaticity are compared and investigated and a historical perspective of the field is given. Some of the larger heterocyclic materials that are evaluated in this concept article have been around for more than one hundred years, yet their chemistry and properties are not well known/understood.
Chiral separation of phospine‐containing α‐amino acid derivatives using two complementary cellulosic stationary phases in supercritical fluid chromatography
Authors: West Caroline , Bouet Alexis , Gillaizeau Isabelle , Coudert Gerard , Lafosse Michel , Lesellier Eric 
Published: June 2009

AbstractEnantiomeric separations of six amino‐acid derivatives have been studied using packed‐column supercritical fluid chromatography with two polysaccharide‐based enantioselective stationary phases: cellulose tris(3,5‐dimethylphenylcarbamate) and cellulose tris(3‐chloro‐4‐methylphenylcarbamate) (Lux Cellulose‐1 and ‐2). The effect of analyte structure on retention and separation was studied. Varied mobile phase compositions were investigated: alcohol modifier percentage was increased from 3 to 40% but smaller amounts were most effective in separating these compounds. Besides, ethanol was preferred to methanol or isopropanol as it proved to be a good compromise to achieve sufficient resolution in a reasonable analysis time. Moreover, a carbon dioxide‐ethanol mixture allows performing analyses in safe and green conditions. The effect of temperature at constant mobile phase composition was explored between 10 and 40°C. In most cases, increasing the temperature improved the chiral separation, up to an optimum temperature. The results are discussed in line with the structure variation of the racemic derivatives analyzed and the two columns are compared. The two columns were shown to provide complementary selectivities for the investigated solutes: whereas Lux 1 provided separation for five of the six racemates, Lux 2 could resolve the last racemic mixture. Finally, optimized conditions of separation are defined. Chirality, 2010. © 2009 Wiley‐Liss, Inc.
Bayesian robust transformation and variable selection: A unified approach
Authors: Gottardo Raphael , Raftery Adrian 
Published: June 2009

AbstractThe authors consider the problem of simultaneous transformation and variable selection for linear regression. They propose a fully Bayesian solution to the problem, which allows averaging over all models considered including transformations of the response and predictors. The authors use the Box‐Cox family of transformations to transform the response and each predictor. To deal with the change of scale induced by the transformations, the authors propose to focus on new quantities rather than the estimated regression coefficients. These quantities, referred to as generalized regression coefficients, have a similar interpretation to the usual regression coefficients on the original scale of the data, but do not depend on the transformations. This allows probabilistic statements about the size of the effect associated with each variable, on the original scale of the data. In addition to variable and transformation selection, there is also uncertainty involved in the identification of outliers in regression. Thus, the authors also propose a more robust model to account for such outliers based on at‐distribution with unknown degrees of freedom. Parameter estimation is carried out using an efficient Markov chain Monte Carlo algorithm, which permits moves around the space of all possible models. Using three real data sets and a simulated study, the authors show that there is considerable uncertainty about variable selection, choice of transformation, and outlier identification, and that there is advantage in dealing with all three simultaneously. The Canadian Journal of Statistics 37: 361–380; 2009 © 2009 Statistical Society of Canada
Pathway sensitivity analysis for detecting pro‐proliferation activities of oncogenes and tumor suppressors of epidermal growth factor receptor‐extracellular signal‐regulated protein kinase pathway at altered protein levels
Authors: Li Hu , Ung Choong Yong , Ma Xiao Hua , Liu Xiang Hui , Li Bao Wen , Low Boon Chuan , Chen Yu Zong 
Published: June 2009

AbstractBACKGROUND:Mathematic models and sensitivity analyses of biologic pathways have been used for exploring the dynamics and for detecting the key components of signaling pathways.METHODS:The authors previously developed a mathematic model of the epidermal growth factor receptor‐extracellular signal‐regulated protein kinase (EGFR‐ERK) pathway using ordinary differential equations from existing EGFR‐ERK pathway models. By using prolonged ERK activation as an indicator that may lead to cell proliferation under certain circumstances, in the current study, a pathway sensitivity analysis was performed to test its capability of detecting pro‐proliferative activities through altered protein levels to examine the effects on ERK activation.RESULTS:The analysis revealed that 12 of 20 oncoproteins and 4 of 5 tumor suppressors were detected, consistent with reported experimental works. Because pathway dynamics depend on many factors, some of which were not included in the current models, failure to detect all known oncogenes and tumor suppressors can be because of the failure to include relevant crosstalk to other pathway components.CONCLUSIONS:Overall, the current results indicated that pathway sensitivity analysis is a useful approach for detecting and distinguishing pro‐proliferation activities of oncoproteins and suppressed proliferative activities of tumor suppressors at altered protein levels at least in the EGFR‐ERK model. Cancer 2009. © 2009 American Cancer Society.
Yes‐associated protein is an independent prognostic marker in hepatocellular carcinoma
Authors: Xu Michelle Z. , Yao Tzy‐Jyun , Lee Nikki P. Y. , Ng Irene O. L. , Chan Yuk‐Tat , Zender Lars , Lowe Scott W. , Poon Ronnie T. P. , Luk John M. 
Published: June 2009

AbstractBACKGROUND:Yes‐associated protein (YAP), a downstream target of the Hippo signaling pathway, was recently linked to hepatocarcinogenesis in a mouse hepatocellular carcinoma (HCC) model. The objective of the current study was to investigate the clinical significance of YAP in HCC and its prognostic values in predicting survival and tumor recurrence.METHODS:The authors collected 177 pairs of tumor and adjacent nontumor tissue from HCC patients with definitive clinicopathologic and follow‐up data. YAP expression was determined by immunohistochemistry, Western blot analysis, and quantitative polymerase chain reaction. Association of YAP with each clinicopathologic feature was analyzed by Pearson chi‐square test, and HCC‐specific disease‐free survival and overall survival by Kaplan‐Meier curves and log‐rank test. Multivariate Cox regression analyses of YAP in HCC were also performed.RESULTS:YAP was expressed in the majority of HCC cases (approximately 62%) and mainly accumulated in the tumor nucleus. Overexpression of YAP in HCC was significantly associated with poorer tumor differentiation (Edmonson grade; P = .021) and high serum α‐fetoprotein (AFP) level (P < .001). Kaplan‐Meier and Cox regression data indicated that YAP was an independent predictor for HCC‐specific disease‐free survival (hazards ratio [HR], 1.653; 95% confidence interval [95% CI], 1.081‐2.528 [P = .02]) and overall survival (HR, 2.148; 95% CI, 1.255‐3.677 [P = .005]).CONCLUSIONS:YAP is an independent prognostic marker for overall survival and disease‐free survival times of HCC patients and clinicopathologically associated with tumor differentiation and serum AFP level. It is a potential therapeutic target for this aggressive malignancy. Cancer 2009. © 2009 American Cancer Society.
Cancer treatment adherence among low‐income women with breast or gynecologic cancer
Authors: Ell Kathleen , Vourlekis Betsy , Xie Bin , Nedjat‐Haiem Frances R. , Lee Pey‐Jiuan , Muderspach Laila , Russell Christy , Palinkas Lawrence A. 
Published: June 2009

AbstractBACKGROUND:The authors implemented a controlled, randomized trial that compared 2 interventions: the provision of written resource navigation information (enhanced usual care [EUC]) versus written information plus patient navigation (TPN) aimed at improving adjuvant treatment adherence and follow‐up among 487 low‐income, predominantly Hispanic women with breast cancer or gynecologic cancer.METHODS:Women were randomized to receive either TPN or EUC; and chemotherapy, radiation therapy, hormone therapy, and follow‐up were assessed over 12 months. Patients with breast cancer were analyzed separately from patients with gynecologic cancer.RESULTS:Overall adherence rates ranged from 87% to 94%, and there were no significant differences between the TPN group and the EUC group. Among women with breast cancer, 90% of the EUC group and 88% of the TPN group completed chemotherapy (14% of the EUC group and 26% of the TPN group delayed the completion of chemotherapy), 2% of the EUC group and 4% of the TPN group failed to complete chemotherapy, and 8% of the EUC group and 7% of the TPN group refused chemotherapy. Radiation treatment adherence was similar between the groups: Ninety percent of patients completed radiation (40% of the EUC group and 42% of the TPN group delayed the completion of radiation); in both groups, 2% failed to complete radiation, and 8% refused radiation. Among gynecologic patients, 87% of the EUC group and 94% of the TPN group completed chemotherapy (41% of the EUC group and 31% of the TPN group completed it with delays), 7% of the EUC group and 6% of the TPN group failed to complete chemotherapy, 6% of the EUC refused chemotherapy, 87% of the EUC group and 84% of the TPN group completed radiation (51% of the EUC group and 42% of the TPN with delays), 5% of the EUC group and 8% of the TPN group failed to complete radiation, and 8% of the EUC group and 5% of the TPN group refused radiation.CONCLUSIONS:Treatment adherence across randomized groups was notably higher than reported in previous studies, suggesting that active telephone patient navigation or written resource informational materials may facilitate adherence among low‐income, predominantly Hispanic women. Adherence also may have be facilitated by federal‐state breast and cervical cancer treatment funding. Cancer 2009. © 2009 American Cancer Society.