bluuebunny/crossref_metadata_2025_split huggingface dataset:
Enhancement of cellulose saccharification kinetics using an ionic liquid pretreatment step
Authors: Dadi Anantharam P. , Varanasi Sasidhar , Schall Constance A. 
Published: August 2006

AbstractHydrolysis of cellulose to glucose in aqueous media catalyzed by the cellulase enzyme system suffers from slow reaction rates due in large part to the highly crystalline structure of cellulose and inaccessibility of enzyme adsorption sites. In this study, an attempt was made to disrupt the cellulose structure using the ionic liquid (IL), 1‐n‐butyl‐3‐methylimidazolium chloride, in a cellulose regeneration strategy which accelerated the subsequent hydrolysis reaction. ILs are a new class of non‐volatile solvents that exhibit unique solvating properties. They can be tuned to dissolve a wide variety of compounds including cellulose. Because of their extremely low volatility, ILs are expected to have minimal environmental impact on air quality compared to most other volatile solvent systems. The initial enzymatic hydrolysis rates were approximately 50‐fold higher for regenerated cellulose as compared to untreated cellulose (Avicel PH‐101) as measured by a soluble reducing sugar assay. © 2006 Wiley Periodicals, Inc.
Integrated non‐invasive system for quantifying secreted human therapeutic hIL2
Authors: Yung Chong Wing , Barbari Timothy A. , Bentley William E. 
Published: August 2006

AbstractCell encapsulation has been used to treat diabetes, amyotrophic lateral sclerosis, and other chronic ailments by the secretion of therapeutic proteins in vivo. Detection of these proteins typically requires invasive procedures such as blood sampling or device extraction, however. In this article, a non‐invasive means of measuring secreted protein concentration using a co‐expressed red fluorescent protein marker is developed. A bicistronic expression vector was constructed for the intracellular production of a red fluorescent protein marker and the secreted production of human interleukin‐2 (hIL2). The destabilized red fluorescent protein, DsExDR, was selected for its rapid turnover, as well as its ability to emit red light, which is readily transmitted through mammalian tissue. Transfections of this bicistronic vector into three cell lines C2C12, HEK293, and Jurkat showed linear correlations between the expressed proteins, DsExDR (intracellular) and hIL2 (secreted), with transfection DNA concentration. Correspondingly, there was a linear correlation between secreted product (hIL2) and intracellular marker (DsExDR). As transfection DNA was increased, Jurkat cells were found to increase secreted hIL2 in direct proportion to the accumulated DsExDR. HEK293 and C2C12 cells expressed and secreted significantly more hIL2 than the Jurkat cells, while still maintaining a linear relationship. Thus, all three cell lines were suitable hosts for the bicistronic expression of DsExDR and expression and secretion of therapeutic hIL2. This reporting strategy may find the greatest use in cell encapsulation therapy. © 2006 Wiley Periodicals, Inc.
A new approach for the recovery of precious metals from solution and from leachates derived from electronic scrap
Authors: Macaskie L.E. , Creamer N.J. , Essa A.M.M. , Brown N.L. 
Published: August 2006

AbstractA new approach is described for the recovery of precious metals (PMs: Au, Pd and Ag) with >99% efficiency from aqueous solution utilising biogas produced during the aerobic growth of Klebsiella pneumoniae. Gold was recovered from electronic scrap leachate (∼95%) by this method, with some selectivity against Cu. The recovered PM solids all contained metal and sulphur as determined by energy dispersive X‐ray microanalysis (EDX). X‐ray powder diffraction analysis (XRD) showed no crystalline metal sulphur compounds but a crystalline palladium amine was recorded. Silver was recovered as a sulphide (found by EDX), carbonate and oxide (found by XRD). EDX analysis of the Au‐precipitate showed mainly gold and sulphur, with some metallic Au(0) detected by XRD. The gold compound was shock‐sensitive; upon grinding it detonated to leave a sooty black deposit. Biotechnol. Bioeng. 2007;96:631–639. © 2006 Wiley Periodicals, Inc.
Cost‐effective engineering of a small‐scale bioreactor
Authors: Bartholomew Sadie R. , Tansey John T. 
Published: August 2006

AbstractSeveral methods exist for increasing the scale of cell culture in the laboratory. While these methods provide significant increases in biomass, they are often prohibitively expensive for many laboratories. We have engineered a small‐scale bioreactor with a novel means of introducing oxygen through the catalytic breakdown of hydrogen peroxide using a manganese oxide catalyst. We have also adapted and modified an existing assay for dissolved oxygen to be compatible with culture conditions. In this system we have been able to culture CHO cells at densities of up to 107 cells/mL without the use of automated feedback systems. Biotechnol. Bioeng. 2007;96: 401–407. © 2006 Wiley Periodicals, Inc.
Scale‐up criteria of square tank surface aerator
Authors: Rao Achanta Ramakrishna , Kumar Bimlesh 
Published: August 2006

AbstractOxygen transfer rate and the corresponding power requirement to operate the rotor are vital for design and scale‐up of surface aerators. Present study develops simulation or scale‐up criterion correlating the oxygen transfer coefficient and power number along with a parameter governing theoretical power per unit volume (X, which is defined as equal to F4/3R1/3, where F and R are impellers' Froude and Reynolds number, respectively). Based on such scale‐up criteria, design considerations are developed to save energy requirements while designing square tank surface aerators. It has been demonstrated that energy can be saved substantially if the aeration tanks are run at relatively higher input powers. It is also demonstrated that smaller sized tanks are more energy conservative and economical when compared to big sized tanks, while aerating the same volume of water, and at the same time by maintaining a constant input power in all the tanks irrespective of their size. An example illustrating how energy can be reduced while designing different sized aerators is given. The results presented have a wide application in biotechnology and bioengineering areas with a particular emphasis on the design of appropriate surface aeration systems. Biotechnol. Bioeng. 2007;96: 464–470. © 2006 Wiley Periodicals, Inc.
Enhancing oxygen tension and cellular function in alginate cell encapsulation devices through the use of perfluorocarbons
Authors: Khattak Sarwat F. , Chin Kyuong‐sik , Bhatia Surita R. , Roberts Susan C. 
Published: August 2006

AbstractEncapsulation devices are often hindered by the inability to achieve sufficient oxygen levels for sustaining long‐term cell survival both in vivo and in vitro. We have investigated the use of synthetic oxygen carriers in alginate gels to improve metabolic activity and viability of HepG2 cells over time. Perfluorocarbons (PFCs), specifically perfluorotributylamine (PFTBA) and perfluorooctylbromide (PFOB), were emulsified with alginate and used to encapsulate HepG2 cells in a spherical geometry. Cellular state was assessed using the MTT assay and Live/Dead® stain as well as through analysis of both lactate and lactate dehydrogenase (LDH) levels which are indirect indicators of oxygen availability. Addition of 1% surfactant resulted in stable emulsions with evenly dispersed PFC droplets of the order of 1–2 µm in diameter, with no influence on cell viability. Both PFCs evaluated were effective in increasing cellular metabolic activity over alginate‐only gels. The presence of 10% PFOB significantly increased cellular growth rate by 10% and reduced both intracellular LDH and extracellular lactate levels by 20–40%, improving glucose utilization efficiency. The characteristic drop in cellular metabolic activity upon encapsulation was eliminated with addition of 10% PFC and viability was better maintained throughout the bead, with a significant decrease in necrotic core size. Results were consistent under a physiologically relevant 5% oxygen environment. The incorporation of PFC synthetic oxygen carriers into encapsulation matrices has been successfully applied to improve cell function and viability with implication for a variety of tissue engineering applications. Biotechnol. Bioeng. 2007;96: 156–166. © 2006 Wiley Periodicals, Inc.
Effect of ferrous ion on the biological activity in a UASB reactor: Mathematical modeling and verification
Authors: Vlyssides Apostolos , Barampouti Elli Maria , Mai Sofia 
Published: August 2006

AbstractThe effect of ferrous ion on the biological activity in a upflow anaerobic sludge blanket (UASB) reactor was studied. A mathematical model was developed and validated in order to simulate the dynamic behavior of a UASB reactor. This model took into consideration of all the biological and physicochemical reactions. The model was able to simulate the accumulation of iron in the sludge bed and its effect on the biological activity of the anaerobic sludge. A significant increase in the maximum uptake rate of methanogens and acidogens was revealed when iron was supplemented to the UASB reactor. The addition of ferrous iron induced a stable and excellent COD conversion rate. The model can be a useful tool for the prediction of process performance in the future and can be used to assist in the operation of biogas plants. The ferrous ion addition proved to enhance the biological activity of UASB sludge. Thus, the model can be used for the design of treatment plants that will take advantage of the benefits of iron addition. Biotechnol. Bioeng. 2007;96:853–861. © 2006 Wiley Periodicals, Inc.
Aziridide‐Based Inhibitors of Cathepsin L: Synthesis, Inhibition Activity, and Docking Studies
Authors: Vicik Radim , Busemann Matthias , Gelhaus Christoph , Stiefl Nikolaus , Scheiber Josef , Schmitz Werner , Schulz Franziska , Mladenovic Milena , Engels Bernd , Leippe Matthias , Baumann Knut , Schirmeister Tanja 
Published: August 2006

AbstractA comprehensive screening of N‐acylated aziridine (aziridide) based cysteine protease inhibitors containing either Boc‐Leu‐Caa (Caa=cyclic amino acid), Boc‐Gly‐Caa, or Boc‐Phe‐Ala attached to the aziridine nitrogen atom revealed Boc‐(S)‐Leu‐(S)‐Azy‐(S,S)‐Azi(OBn)2 (18 a) as a highly potent cathepsin L (CL) inhibitor (Ki=13 nM) (Azy=aziridine‐2‐carboxylate, Azi=aziridine‐2,3‐dicarboxylate). Docking studies, which also accounted for the unusual bonding situations (the flexibility and hybridization of the aziridides) predict that the inhibitor adopts a Y shape and spans across the entire active site cleft, binding into both the nonprimed and primed sites of CL.
An association between glutathione S‐transferase P1 gene polymorphism and younger age at onset of lung carcinoma
Authors: Miller David P. , Asomaning Kofi , Liu Geoffrey , Wain John C. , Lynch Thomas J. , Neuberg Donna , Su Li , Christiani David C. 
Published: August 2006

AbstractBACKGROUND.Among the genes that encode the glutathione S‐transferase (GST) superfamily of Phase 2 metabolizing enzymes, GSTP1 has the highest expression in the lung. The polymorphic GSTP1 gene encodes glutathione S‐transferase π, which is an enzyme that detoxifies cigarette carcinogens, such as benzo‐[a]‐pyrene. The variant GSTP1 GG genotype is associated with lower enzymatic activity and higher DNA adduct levels in human lymphocytes compared with the AA genotype.METHODS.The authors evaluated the association of GSTP1 genotypes with lung cancer in 1921 cases and 1343 controls of Caucasian descent by using polymerase chain reaction‐restriction fragment length polymorphism techniques. The results were analyzed with multiple logistic regression adjusting for age, gender, smoking status, and pack‐years. To investigate specifically the subset of younger lung cancer patients and controls, the effect of age (either as a dichotomous or continuous variable in separate models) was analyzed as a modifying factor of the association between the GSTP1 polymorphism and lung cancer.RESULTS.The GSTP1 GG genotype was not associated with an overall increased risk of lung cancer (adjusted odds ratio, 1.02; 95% confidence interval [95% CI], 0.78–1.34) compared with the GSTP1 AA genotype. In both models that evaluated the gene‐age interaction, an overall statistically significant interaction (P < .01) was observed between age and the GG genotype. However, for the model that included age as a dichotomous variable, the odds ratio of lung cancer risk with the GG genotype compared with the AA among individuals age ≤50 years was 2.67 (95% CI, 1.36–5.22); in older individuals, the risk was 0.87 (95% CI, 0.65–1.2).RESULTS.The GSTP1 GG genotype was associated with increased lung cancer susceptibility among younger study participants. Cancer 2006. © 2006 American Cancer Society.
Neuropathic pain: symptoms, models, and mechanisms
Authors: Beggs Simon , Salter Michael W. 
Published: August 2006

AbstractPeripheral neuropathic pain is the most debilitating of all clinical pain syndromes and affects a large and growing number of people worldwide. There are diverse causes for peripheral neuropathic pain, which may be experienced after traumatic nerve injury or from diseases that affect peripheral nerves, such as diabetes, HIV/AIDS, and cancer, and it can also result from toxic chemicals, such as cancer chemotherapy agents. Despite these varying causes, it is clear that neuropathic pain is due to persistent pathological alterations resulting in hyperexcitability in the peripheral and central nervous systems, and it is the neuropathology that must be targeted for effective therapy of which there is none presently available. Mechanistically, neuropathic pain is distinct from acute pain and inflammatory pain, for which many effective therapies are known. In this review, we describe the relationships between clinical symptoms and experimental models of peripheral neuropathic pain, and we provide a framework for understanding the potential mechanisms that involve primary neuronal dysfunction as well as pathological changes in neuron‐glial signaling. Drug Dev. Res. 67:289–301, 2006. © 2006 Wiley‐Liss, Inc.
Transcriptional profiling of dorsal root ganglia in a neuropathic pain model using microarray and laser capture microdissection
Authors: Davis‐Taber Rachel A. , Scott Victoria E.S. 
Published: August 2006

AbstractChronic neuropathic pain arises following nerve injury and persists long after the initial damage has recovered. To enhance understanding of the molecular mechanisms that underlie this pain state, the gene expression profiles of the dorsal root ganglia (DRG) from spinal nerve ligation (SNL; L5/L6 region) were examined using microarray techniques 14 days post‐insult and compared with gene expression patterns in DRG of sham‐operated animals. There were 350 dysregulated gene products with a majority of those transcripts changing ≥2‐fold. Genes that had an altered expression pattern were classified into the following groups: cellular homeostasis and remodeling, ion channels and receptors, enzymes, immune response, neuronal markers, synaptic plasticity, and a transcription factors category. Several genes involved in synaptic plasticity (e.g., Narp and synaptobrevin) were downregulated, whereas genes involved in the immune response (e.g., MHCII) and cell regeneration/proliferation (e.g., Reg‐2 and GADD45) were upregulated. To obtain a more in‐depth profile of genes that exhibited altered expression in the SNL model, subpopulations of the small nociceptive (diameter <25 µm) and the large mechanosensitive (diameter >40 µm) neurons from the L5/L6 DRG were isolated by laser capture microdissection (LCM). Microarray analysis revealed a greater number of dysregulated genes in the large diameter neurons than in the small neurons. While some genes (e.g., 5HT3A, synaptotagmin 4, GFRα1) showed similar changes in expression in both small and large neurons in the SNL model, several genes were dysregulated in only one neuronal subtype. Altered expression of NPYR5, P2X3, and Nell I occurred only in small neurons whereas altered expression of P2X5, PKCε, and Nav1.1 occurred only in large neurons. For the first time, expression changes that occur in specific subpopulations of neurons isolated by LCM are given and provide a detailed view of the molecular landscape of neuropathic pain in the DRG. The utilization of LCM may help to pinpoint the underlying components that play a role in this complex pathophysiology. Drug Dev. Res. 67:308–330, 2006. © 2006 Wiley‐Liss, Inc.
Expression of the protein related to Dan and Cerberus gene—prdc—During eye, pharyngeal arch, somite, and swim bladder development in zebrafish
Authors: Müller Iris I. , Knapik Ela W. , Hatzopoulos Antonis K. 
Published: August 2006

AbstractThe protein related to Dan and Cerberus, or PRDC, is a secreted glycoprotein, which belongs to the DAN subfamily of bone morphogenetic protein (BMP) antagonists. In zebrafish, prdc is expressed initially around 17 hours postfertilization in the developing eyes and the first two pharyngeal arches. Expression in the eye starts in the outer layers of the optic cup. Later, prdc expression domains are juxtaposed at the edges of the optic cup surrounding the choroid fissure, then gradually becoming restricted to a small site in the ventral marginal zone. Prdc expression in the arch mesenchyme expands stepwise to the remaining posterior arches. Prdc is also detectable in the ventral part of the somites and the mesenchyme of the swim bladder. The relatively late appearance during development is a unique feature of Prdc among BMP antagonists. Moreover, the complexity of the prdc expression pattern suggests possible roles in eye development, pharyngeal arch remodeling, somitogenesis, and swim bladder organogenesis. Developmental Dynamics 235:2881–2888, 2006. © 2006 Wiley‐Liss, Inc.
Distinct sources and targets of IL‐10 during dendritic cell‐driven Th1 and Th2 responses in vivo
Authors: Perona‐Wright Georgia , Jenkins Stephen J. , Crawford Alison , Gray David , Pearce Edward J. , MacDonald Andrew S. 
Published: August 2006

AbstractDendritic cells (DC) can both initiate an immune response and dictate its character. Cytokines are critically involved in this process and, although interleukin (IL)‐10 is known as a potent immunosuppressant, the impact of its release from DC remains unclear. Here, we transfer pathogen‐conditioned murine DC in vivo and show that, while DC‐derived IL‐10 can act to limit Th1 development, it is not required for Th2 induction. In both Th2 and Th1 settings, however, IL‐10 from cells other than the initiating DC dominates the regulation of the emerging effector cell populations. Surprisingly, the critical source of IL‐10 in this process is neither T nor B cells. These data illustrate the distinct actions of IL‐10 during differently polarised, pathogen‐focussed, DC‐driven immune responses in vivo.
Drug Self‐Templated Synthesis of Ibuprofen/Mesoporous Silica for Sustained Release
Authors: Qu Fengyu , Zhu Guangshan , Lin Huiming , Sun Jinyu , Zhang Daliang , Li Shougui , Qiu Shilun 
Published: August 2006

AbstractThe synthesis of Ibuprofen/mesoporous silica has been achieved by a drug self‐templated one‐step co‐condensation process. The drug template of Ibuprofen, a co‐template of 3‐aminopropyltriethoxysilane (APTES), and tetraethoxysiliane (TEOS) were self‐assembled into Ibuprofen/mesoporous silica in a neutral aqueous reaction system. This drug/mesoporous silica was characterized by powder XRD diffraction, FTIR spectroscopy, N2 adsorption/desorption, TEM, and 29Si/MAS and 13C/MAS NMR spectroscopy. The Ibuprofen/mesoporous silica system gives a well‐sustained release profile. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Zinc Hydrazide and Zinc Alkoxide Hydrazide Cages with Zn4N8 and Zn4N6O Cores – Cluster Isomerism as a Result of Subtle Changes in Ligand Size
Authors: Jana Surajit , Fröhlich Roland , Mitzel Norbert W. 
Published: August 2006

AbstractThe hydrazide cluster [(iPrZn)4(NHNMe2)4] (1) was synthesised by the reaction of diisopropylzinc with N,N‐dimethylhydrazine and was characterised by 1H‐ and 13C NMR and IR spectroscopy, mass spectrometry, elemental analysis and X‐ray crystallography. This compound forms asymmetric aggregates containing Zn4N8 cores. The Zn atoms in these aggregates are arranged in topological tetrahedra in which the triangular faces are bridged by NHNMe2 substituents. Each NH group is connected to two Zn atoms and each NMe2 group to one Zn atom. Alkoxide clusters were prepared in one‐pot syntheses by treating diisopropylzinc solutions with mixtures of N,N‐dimethylhydrazine and ROH (R = Et, iPr). The resulting compounds have the formula [(iPrZn)4(NHNMe2)3(OR)] [R = Et (3), iPr(4)] and contain Zn4N6O cages, such that one NHNMe2 in 1 is replaced by one alkoxide group. Two different aggregation modes were found for these Zn4N6O cages. In compound 3, one Zn atom is bound to two NMe2 groups and one NH group. The other three Zn atoms each have three bonds to NH groups and one dative bond to an NMe2 group. The cage consists of one four‐membered and one six‐membered ring as well as four five‐membered rings. In compound 4, the fourth zinc atom is exclusively bonded to three anionic NH functions in such a way that the rings in the cage are all five‐membered. Compounds 3 and 4 were characterised by NMR spectroscopy and single‐crystal X‐ray diffraction. Hydrazide hydroxide clusters were also obtained through the reaction of a diisopropylzinc solution with N,N‐dimethylhydrazine and a small amount of water. The structure of the resulting cocrystalline material, [(iPrZn)4(NHNMe2)4]·[(iPrZn)4(NHNMe2)3(OH)] (2), was also confirmed by X‐ray diffraction. The hydroxide cluster in 2 contains a Zn4N6O cage, with a similar aggregation mode to that of 4. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Lithium Oligophosphanediides in the Li/PhPCl2 System
Authors: Stein Daniel , Dransfeld Alk , Flock Michaela , Rüegger Heinz , Grützmacher Hansjörg 
Published: August 2006

AbstractOptimized conditions for the selective synthesis of [Li2(PnPhn)(tmeda)x] (n = 2, 3, 4) have been developed. X‐ray diffraction with single crystals show [Li2(P2Ph2)(tmeda)2] and [Li2(P4Ph4)(tmeda)2] to be ion triples, while for n = 3 the ion pair [Li(tmeda)2]+[Li(P3Ph3)(tmeda)]– is observed. NMR experiments support the assumption that these structures are retained in solution. Structural differences between the lithium and the corresponding sodium compounds, [Na2(PnPhn)(tmeda)x], can be partially rationalized using the electrostatic stabilization parameters, ESP = Σ(1/r) + Σ(1/r) – Σ(1/r); M = Li, Na. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Uranium(IV) Complexes of Calix[5]arene
Authors: Salmon Lionel , Thuéry Pierre , Ephritikhine Michel 
Published: August 2006

AbstractThe μ‐oxo uranium(V) compound [Hpy]2[{U(calix[5]arene–5H)}2(μ2‐O)]·4py (1·4py) was the sole product isolated from the reaction of UCl4 and calix[5]arene unless the last traces of water were eliminated by thoroughly drying the macrocyclic molecule; under such strictly anhydrous conditions, thebinuclear UIV complex [Hpy]3[U2(calix[5]arene–5H)Cl6]·4py (2·4py) was obtained. Treatment of U(OTf)3 or U(OTf)4 (OTf = OSO2CF3) with calix[5]arene gave the dimeric UIV complex [U(calix[5]arene–4H)(py)]2·4py (3·4py); compound 3 was also formed when no precautions were taken to avoid the presence of traces of water, together with compound 1. The crystal structures of the complexes were determined. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)