bluuebunny/crossref_metadata_2025_split huggingface dataset:
Functionalized Chiral Ionic Liquids: A New Type of Asymmetric Organocatalysts and Nonclassical Chiral Ligands
Authors: Luo Sanzhong , Zhang Long , Cheng Jin‐Pei 
Published: June 2009

AbstractBy judiciously anchoring functional groups onto chiral ionic liquids, functionalized chiral ionic liquids (FCILs) are emerging as a new type of asymmetric organocatalysts and nonclassical chiral ligands. This Focus Review highlights the applications of FCILs from the viewpoint of asymmetric catalysis. We focus mainly on the de novo designed and synthesized FCILs which likely still maintain the typical ionic liquids properties, and in a few cases relevant ionic liquid immobilized chiral catalysts are briefly discussed.
Isocyanate‐ and Isothiocyanate‐Derived RuIV‐Based Alkylidenes: Synthesis, Structure, and Activity
Authors: Kumar P. Santhosh , Wurst Klaus , Buchmeiser Michael R. 
Published: June 2009

AbstractThe synthesis and characterization of a series of isocyanate‐ and isothiocyanate‐derived second generation Grubbs–Hoveyda‐type ruthenium–alkylidene complexes, that is, [Ru(NCO)2(IMesH2)(CH‐2‐(2‐PrO)‐C6H4)] (1), [Ru(NCO)2(1,3‐dimesityl‐3,4,5,6‐tetrahydropyrimidin‐2‐ylidene)(=CH‐2‐(2‐PrO)‐C6H4)] (2), [Ru(NCS)2(IMesH2)(CH‐2‐(2‐PrO)‐C6H4)] (3), and [Ru(NCS)2(1,3‐dimesityl‐3,4,5,6‐tetrahydropyrimidin‐2‐ylidene)(CH‐2‐(2‐PrO)‐C6H4)] (4), and their activity in various metathesis reactions are described. Compounds 1–4 were prepared by reaction of the parent complexes [RuCl2(IMesH2)(CH‐2‐(2‐PrO)C6H4)] (5) (IMesH2=1,3‐bis‐(2,4,6‐trimethylphenyl)‐4,5‐dihydroimidazol‐2‐ylidene) and [RuCl2(1,3‐dimesityl‐3,4,5,6‐tetrahydropyrimidin‐2‐ylidene)(CH‐2‐(2‐PrO)‐C6H4)] (6) with silver cyanate and thiocyanate, respectively. The X‐ray structure of 1 was determined, confirming the isocyanate‐type bonding of the ligand. The isothiocyanate‐type bonding in 3 and 4 was unambiguously confirmed by IR and 13C NMR spectroscopy. The isocyanate‐derived complexes 1 and 2 were found to be excellent catalysts for the ring‐opening metathesis polymerization (ROMP) of cis‐cycloocta‐1,5‐diene (COD). Both 1 and 2 yielded poly(COD) with a trans‐content of about 80 %. First‐order kinetics with unprecedentedly high rate constants of polymerization (kp=0.068 and 0.26 s−1, respectively) were observed. Compounds 3 and 4 were also active initiators for the ROMP of COD, however, they generated poly(COD) with a cis‐content of 80 and 67 %, respectively. Complexes 1 and 2 also showed good catalytic activity in cross‐metathesis (CM) reactions. Finally, 1–4 were also found to be excellent catalysts for the regioselective cyclopolymerization of diethyl 2,2‐dipropargylmalonate (DEDPM), resulting in poly(DEDPM) almost entirely based on five‐membered repeat units, that is, cyclopent‐1‐ene‐1,2‐vinylenes.
Synthesis of Extremely π‐Extended Porphyrin Tapes from Hybrid meso‐meso Linked Porphyrin Arrays: An Approach Towards the Conjugation Length
Authors: Ikeda Toshiaki , Aratani Naoki , Osuka Atsuhiro 
Published: June 2009

AbstractDirectly meso‐meso, β‐β, β‐β triply linked porphyrin arrays are exceptional π‐conjugated molecules exhibiting remarkably red‐shifted absorption bands extending deeply in the IR region. In order to determine the effective conjugated length (ECL), we embarked on the synthesis of the porphyrin tapes far beyond the 12‐mer, which is the longest we have prepared so far. In this study, to find the compromise between the feasibility of the meso‐meso coupling reaction up to longer arrays and the sufficient solubility and chemical stability of the resultant porphyrin tapes, we prepared hybrid meso‐meso linked porphyrin arrays BOn up to 24‐mer, which have two different aryl groups, a 2,4,6‐tris(3,5‐di‐tert‐butylphenoxy) phenyl group (Ar1) and a 3,5‐dioctyloxy phenyl group (Ar2). All these arrays were effectively converted into the corresponding triply linked porphyrin tapes TBOn by oxidation with DDQ‐Sc(OTf)3. Importantly, the low energy Q‐band‐like absorption bands of TBOn are progressively red‐shifted with an increase in the number of porphyrins n until 16 but the red‐shift is saturated at n=16, indicating the ECL of the porphyrin tape to be around 14–16. The regularly introduced meso‐aryl bulky substituents impose facial encumbrance, hence leading to the effective suppression of π–π interactions as well as improvement of the chemical stabilities of TBOn.
Cover Picture: Reverse‐Selective Microporous Membrane for Gas Separation (Chem. Asian J. 7/2009)
Authors: Sawamura Ken‐ichi , Izumi Teruaki , Kawasaki Kiyotoshi , Daikohara Shintaro , Ohsuna Tetsu , Takada Mitsuko , Sekine Yasushi , Kikuchi Eiichi , Matsukata Masahiko 
Published: June 2009

AbstractReverse‐selective membranes, through which bigger molecules selectively permeate, are attractive for developing chemical processes utilizing hydrogen because they can maintain the high partial pressure of hydrogen required for further downstream utilization. Although several of these chemical processes are operated above 473 K, membranes with outstanding reverse‐selective separation performance at these temperatures are still to be reported. M. Matsukata et al. propose a new adsorption‐based reverse‐selective membrane that utilizes a Na cation occluded in a zeolitic framework. The membrane developed in this work enables selective permeation and separation of bigger polar molecules, such as methanol and water, from hydrogen above 473 K. For more information, see their Full Paper on page 1070 ff.magnified image
The big carrot: High‐stakes incentives revisited
Authors: Brañas‐Garza Pablo , García‐Muñoz Teresa , Neuman Shoshana 
Published: June 2009

AbstractUsing an international dataset of about 35 000 subjects, this paper provides an empirical example of high‐stakes incentives in relation to religious practice. First, we show that incentives (based on absolute belief) play a salient role in religious performance. Second, we find that when both positive (heaven) and negative (hell) incentives are available the former are more effective than the latter. Specifically, it is shown that beliefs in heaven are much more relevant than beliefs in hell when estimating the production of religious commodities (church‐attendance and praying equations). Copyright © 2009 John Wiley & Sons, Ltd.
Modulation of Zn‐induced hyperinsulinemia/insulin resistance in Wistar rat fed modified poultry eggΨ
Authors: Taneja Satish Kumar , Mandal Reshu 
Published: June 2009

AbstractExcessive bioavailability of Zn causes Cu and Mg deficiencies resulting in hyperglycemia and hyperinsulinemia/insulin resistance. These defects may ameliorate if the ionic imbalance in them is corrected. In view of this, three groups of rats were included in this study. Initially, they were fed on semi‐synthetic equicalories basal diet containing 20 mg Zn (control, group‐I), on 40 mg Zn (group‐II) and 80 mg Zn/kg diet (group‐III) respectively for 3 months. Thereafter, half of the rats in group‐II and III were shifted on Cu and Mg enriched modified poultry egg (MEΨ) mixed diets (groups‐IIME and IIIME) while the remaining were continued to feed on their respective diets for another 3 months completing a total of 6 months. Hyperglycemia, hyperinsulinemia, hypercortisolemia, hyperzincemia, hypercupremia and hypermagnesaemia with corresponding increase of lipid droplets in the zona fasciculate of adrenal cortex and reduction in liver glycogen content in rats of groups‐II and III were recorded. These changes were linked with a rise in Zn and fall in Cu and Mg in their liver. The addition of MEΨ in their diets led to fall of Zn and rise in liver Cu and Mg, and fall in serum Zn, Cu and Mg resulting in the improvement of glucose disposal, increase in insulin sensitivity, reduction in lipid droplets in zona fasciculate and increase in glycogen content in the liver approaching closer to the control group‐I. The data suggest that these MEΨ can serve as non‐pharmacological dietary supplement to prevent insulin resistance/hyperinsulinemia in populations who are at higher risk of diabetes mellitus either due to their genetic predisposition of excessive absorption and retention of Zn or due to higher Zn content in the food chain. © 2009 International Union of Biochemistry and Molecular Biology, Inc.
The ERK signaling cascade—Views from different subcellular compartments
Authors: Yao Zhong , Seger Rony 
Published: June 2009

AbstractThe extracellular signal‐regulated kinase cascade is a central signaling pathway that is stimulated by various extracellular stimuli. The signals of these stimuli are then transferred by the cascade's components to a large number of targets at distinct subcellular compartments, which in turn induce and regulate a large number of cellular processes. To achieve these functions, the cascade exhibits versatile and dynamic subcellular distribution that allows proper temporal and spatial modulation of the appropriate processes. In this review, we discuss the intracellular localizations of different components of the ERK cascade, and the impact of these localizations on their activation and specificity. © 2009 International Union of Biochemistry and Molecular Biology, Inc.
Good modeling practice for PAT applications: Propagation of input uncertainty and sensitivity analysis
Authors: Sin Gürkan , Gernaey Krist V. , Lantz Anna Eliasson 
Published: June 2009

AbstractThe uncertainty and sensitivity analysis are evaluated for their usefulness as part of the model‐building within Process Analytical Technology applications. A mechanistic model describing a batch cultivation of Streptomyces coelicolor for antibiotic production was used as case study. The input uncertainty resulting from assumptions of the model was propagated using the Monte Carlo procedure to estimate the output uncertainty. The results showed that significant uncertainty exists in the model outputs. Moreover the uncertainty in the biomass, glucose, ammonium and base‐consumption were found low compared to the large uncertainty observed in the antibiotic and off‐gas CO2 predictions. The output uncertainty was observed to be lower during the exponential growth phase, while higher in the stationary and death phases ‐ meaning the model describes some periods better than others. To understand which input parameters are responsible for the output uncertainty, three sensitivity methods (Standardized Regression Coefficients, Morris and differential analysis) were evaluated and compared. The results from these methods were mostly in agreement with each other and revealed that only few parameters (about 10) out of a total 56 were mainly responsible for the output uncertainty. Among these significant parameters, one finds parameters related to fermentation characteristics such as biomass metabolism, chemical equilibria and mass‐transfer. Overall the uncertainty and sensitivity analysis are found promising for helping to build reliable mechanistic models and to interpret the model outputs properly. These tools make part of good modeling practice, which can contribute to successful PAT applications for increased process understanding, operation and control purposes. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009
Theoretical analysis of excipient concentrations during the final ultrafiltration/diafiltration step of therapeutic antibody
Authors: Miao Fudu , Velayudhan Ajoy , DiBella Elsie , Shervin Jaclyn , Felo Michael , Teeters Mark , Alred Patricia 
Published: June 2009

AbstractDiafiltration of a protein solution into a new buffer is a common final step in biopharmaceutical manufacturing. However, the excipient concentrations in the retentate are not always equal to their corresponding concentrations in the new buffer (diafiltration buffer). This phenomenon was observed repeatedly during diafiltration of different therapeutic monoclonal antibodies in which the concentrations of histidine and either sorbitol or sucrose (depending on which was chosen for the diafiltration buffer) in the retentate were lower than in the diafiltration buffer. Experimental studies and theoretical analyses of the ultrafiltration/diafiltration (UF/DF) step were carried out to determine the primary causes of the phenomenon and to develop a mathematical model capable of predicting retentate excipient concentrations. The analyses showed that retentate histidine concentration was low primarily because of repulsive charge interactions between positively‐charged histidine molecules and positively‐charged protein molecules, and that volume exclusion effects were secondary for like‐charged molecules. The positively‐charged protein molecules generate an electrical potential that cause an uneven distribution of charged histidine molecules. This interaction was used to construct a mathematical model based on the Poisson‐Boltzmann equation. The model successfully predicted the final histidine concentration in the diafiltered product (retentate) from the UF/DF development and production runs, with good agreement across a wide range of protein and histidine concentrations for four therapeutic monoclonal antibodies. The concentrations of uncharged excipients (sorbitol or sucrose) were also successfully predicted using previously established models, with volume exclusion identified as the primary cause of differences in uncharged excipient concentrations in the retentate and diafiltration buffer. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009
Biocompatible nanoparticles trigger rapid bacteria clustering
Authors: Larsen Mona Utne , Seward Matthew , Tripathi Anubhav , Shapley Nina C. 
Published: June 2009

AbstractThis study reveals an exciting phenomenon of stimulated bacteria clustering. Rapid aggregation and microbial arrest are shown to occur in Escherichia coli solutions of neutral pH when chitosan nanoparticles with positive zeta potential are added. Because chitosan nanoparticles can easily be dispersed in aqueous buffers, the rapid clustering phenomenon requires only minuscule nanoparticle concentrations and will be critical in developing new methods for extricating bacterial pathogens. This work establishes the dominant role of electrostatic attraction in bacteria‐nanoparticle interactions by varying the nanoparticle zeta potential from highly positive to strongly negative values, and by exploring concentration effects. For strongly negative nanoparticles, no clusters form, while aggregates are small and loose at intermediate conditions. In addition, optical density measurements indicate that over 90% of the suspended bacteria flocculate within seconds of being mixed with chitosan nanoparticles of a highly positive surface charge. Finally, the nanoparticles are significantly more efficient as a clustering agent compared to an equal mass of molecular chitosan in solution, as the bacteria‐nanoparticle clusters formed are substantially larger. The bacteria‐nanoparticle aggregation effect demonstrated here promises a rapid separation method for aiding pathogen detection and for flocculation of bacteria in fermentation processes. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009
Selection and growth regulation of genetically modified cells with hapten‐specific antibody/receptor tyrosine kinase chimera
Authors: Tanaka Kento , Kawahara Masahiro , Ueda Hiroshi , Nagamune Teruyuki 
Published: June 2009

AbstractAlthough receptor tyrosine kinases (RTKs) play a pivotal role in the development and maintaining the homeostasis of the body, overexpression or mutation of RTKs often induces tumorigenesis or metastasis. To mimic the function of RTKs, we developed two fusion receptors consisting of anti‐fluorescein antibody single‐chain Fv, extracellular D2 domain of erythropoietin receptor and transmembrane/intracellular domains of epidermal growth factor receptor or c‐fms based on previously constructed antibody/cytokine receptor chimeras. The expression of these chimeric receptors in the hematopoietic cell line Ba/F3 and non‐hematopoietic cell line NIH/3T3 resulted in the activation of receptors themselves, downstream signaling molecules and cell proliferation in response to fluorescein‐conjugated BSA, leading to selective expansion of transduced cells up to almost 100%. These results indicate that the cognate antigen could activate the chimeric receptors even though the wild‐type extracellular domains were switched to the antibody fragment. This is the first study to show that our antigen‐mediated genetically modified cell amplification (AMEGA) system could be applied to non‐hematopoietic cells by utilizing antibody/RTK chimeras. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009
Perfluorocarbon facilitated O2 transport in a hepatic hollow fiber bioreactor
Authors: Chen Guo , Palmer Andre F. 
Published: June 2009

AbstractA mathematical model describing O2 transport in a hepatic hollow fiber (HF) bioreactor supplemented with perfluorocarbons (PFCs) in the circulating cell culture media was developed to explore the potential of PFCs in properly oxygenating a bioartificial liver assist device (BLAD). The 2‐dimensional model is based on the geometry of a commercial HF bioreactor operated under steady‐state conditions. The O2 transport model considers fluid motion of a homogeneous mixture of cell culture media and PFCs, and mass transport of dissolved O2 in a single HF. Each HF consists of three distinct regions: (1) the lumen (conducts the homogeneous mixture of cell culture media and PFCs), (2) the membrane (physically separates the lumen from the extracapillary space (ECS), and (3) the ECS (hepatic cells reside in this compartment). In a single HF, dissolved O2 is predominantly transported in the lumen via convection in the axial direction and via diffusion in the radial direction through the membrane and ECS. The resulting transport equations are solved using the finite element method. The calculated O2 transfer flux showed that supplementation of the cell culture media with PFCs can significantly enhance O2 transport to the ECS of the HF when compared with a control with no PFC supplementation. Moreover, the O2 distribution and subsequent analysis of ECS zonation demonstrate that limited in vivo‐like O2 gradients can be recapitulated with proper selection of the operational settings of the HF bioreactor. Taken together, this model can also be used to optimize the operating conditions for future BLAD development that aim to fully recapitulate the liver's varied functions. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009
Cationic Porphyrins and Analogues as New DNA Topoisomerase I and II Inhibitors
Authors: Shuai Li , Wang Shaoru , Zhang Lixia , Fu Boqiao , Zhou Xiang 
Published: June 2009

Abstractmagnified imageA series of cationic porphyrins, and analogues such as cationic corroles and phthalocyanines were found to have biological activities towards topoisomerases I and II in vitro. Cationic porphyrins and phthalocyanines do not induce Topo I–DNA covalent complexes but inhibit topoisomerase I by direct binding to DNA, which limits topoisomerase I access to the DNA substrate. The lowest concentration where an inhibition effect is clearly visible of some derivatives is between 0.1 and 0.6 μM. Furthermore, some complexes were found to inhibit the activity of the topoisomerase II.
Susceptibility of Aedes aegypti and Culex quinquefasciatus Larvae to Gedunin‐Related Limonoids
Authors: Gurulingappa Hallur , Tare Vrushali , Pawar Pushpa , Tungikar Vijay , Jorapur Yogesh R. , Madhavi Sriram , Bhat Sujata V. 
Published: June 2009

Abstractmagnified imageThe major non‐azadirachtin limonoids such as gedunin (1), epoxyazadiradione (3), nimbocinol (4), and nimolicinol (5) from Azadirachta indica A. Juss (‘neem’) and their derivatives were evaluated for their toxic action against fourth instar larvae of Aedes aegypti L. and Culex quinquefasciatus Say. Gedunin exhibited 100% toxic action against both the mosquito larvae at 50 and 10 ppm. Epoxyazadiradione and epoxynimolicinol also showed significant toxicities (≥50%) against larvae of both mosquito species at 50 ppm. These neem limonoids can have benefits in mosquito‐control programs.
Two New Unprecedented Acetonyl‐Bearing Sesquiterpenes from the Hainan Sponge Dysidea fragilis
Authors: Yu Zhi‐Guo , Li Jia , Li Zhen‐Yu , Guo Yue‐Wei 
Published: June 2009

Abstractmagnified imageTwo new acetonyl‐bearing sesquiterpenes, dysifragilisins A and B (1 and 2, resp.), have been isolated from the Hainan marine sponge Dysidea fragilis. The structures of the new compounds were elucidated on the basis of detailed spectroscopic analyses and by comparison of their NMR data with those of structurally related compounds. A plausible biogenetic pathway is proposed for the origin of compounds 1 and 2.
Phenolic Constituents from Balanophora laxiflora with DPPH Radical‐Scavenging Activity
Authors: She Gai‐Mei , Zhang Ying‐Jun , Yang Chong‐Ren 
Published: June 2009

Abstractmagnified imageBalanophora laxiflora Hemsl. (Balanophoraceae), a dioeciously parasitic plant, has been used as a tonic and for sobering up from drunk by the local people of Yunnan province, China. The 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) assay on the acetone extract of the fresh female plant of B. laxiflora displayed considerable radical‐scavenging activity (SC50=16.4 μg/ml). Further purification of the extract led to the isolation of two new phenolic glycosides, balaxiflorins A and B (1 and 2, resp.), together with 17 known phenolic compounds including 3‐phenylpropanoids, 3, 17–18, four lignans, 4–7, nine hydrolyzable tannins, 8–16, and gallic acid (19). Their structures were determined by detailed spectroscopic analysis. The free‐radical‐scavenging activity of the isolated compounds was examined by DPPH assay.
Flower and Root Oils of the Tunisian Daucus carota L. ssp. maritimus (Apiaceae): Integrated Analyses by GC, GC/MS, and 13C‐NMR Spectroscopy, and in vitro Antibacterial Activity
Authors: Jabrane Aymen , Jannet Hichem Ben , Harzallah‐Skhiri Féthia , Mastouri Maha , Casanova Joseph , Mighri Zine 
Published: June 2009

Abstractmagnified imageThe essential oils from flowers and roots of Daucus carota L. ssp. maritimus were obtained by hydrodistillation and analyzed by combination of GC, GC/MS, and 13C‐NMR. The chemical composition of the flower and root oils of this subspecies is reported here for the first time. Thirty‐two and six compounds were identified in flower and root oils, respectively. A remarkable difference was found between the constituent percentages of the two organs. The chemical composition of the essential oil from flowers was characterized by a high proportion of monoterpene hydrocarbons (68.4%) and belonged to the sabinene (4; 51.6%) chemotype. The oxygenated monoterpenes represented the second major fraction of the same oil among which terpinen‐4‐ol (11.0%) was the predominant compound. Root oil exhibited a surprisingly different composition. Phenolic derivatives (76.3%), myristicin (31; 29.7%), and dillapiole (32; 46.6%) constituted the main fraction. The antibacterial effect resulted in the inhibition of a series of common human pathogenic bacteria, and of some clinically and environmentally isolated strains with significant MIC and MBC values.