bluuebunny/crossref_metadata_2025_split huggingface dataset:
Improved reactor performance and operability in the biotransformation of carveol to carvone using a solid–liquid two‐phase partitioning bioreactor
Authors: Morrish Jenna L.E. , Daugulis Andrew J. 
Published: May 2008

AbstractIn an effort to improve reactor performance and process operability, the microbial biotransformation of (−)‐trans‐carveol to (R)‐(−)‐carvone by hydrophobic Rhodococcus erythropolis DCL14 was carried out in a two phase partitioning bioreactor (TPPB) with solid polymer beads acting as the partitioning phase. Previous work had demonstrated that the substrate and product become inhibitory to the organism at elevated aqueous concentrations and the use of an immiscible second phase in the bioreactor was intended to provide a reservoir for substrates to be delivered to the aqueous phase based on the metabolic rate of the cells, while also acting as a sink to uptake the product as it is produced. The biotransformation was previously undertaken in a two liquid phase TPPB with 1‐dodecene and with silicone oil as the immiscible second phase and, although improvement in the reactor performance was obtained relative to a single phase system, the hydrophobic nature of the organism caused the formation of severe emulsions leading to significant operational challenges. In the present work, eight types of polymer beads were screened for their suitability for use in a solid–liquid TPPB for this biotransformation. The use of selected solid polymer beads as the second phase completely prevented emulsion formation and therefore improved overall operability of the reactor. Three modes of solid–liquid TPPB operation were considered: the use of a single polymer bead type (styrene/butadiene copolymer) in the reactor, the use of a mixture of polymer beads in the reactor (styrene/butadiene copolymer plus Hytrel® 8206), and the use of one type of polymer beads in the reactor (styrene/butadiene copolymer), and another bead type (Hytrel® 8206) in an external column through which fermentation medium was recirculated. This last configuration achieved the best reactor performance with 7 times more substrate being added throughout the biotransformation relative to a single aqueous phase benchmark reactor and 2.7 times more substrate being added relative to the best two liquid TPPB case. Carvone was quantitatively recovered from the polymer beads via single stage extraction into methanol, allowing for bead re‐use. Biotechnol. Bioeng. © 2008 Wiley Periodicals, Inc.
A model predicting delivery of saquinavir in nanoparticles to human monocyte/macrophage (Mo/Mac) cells
Authors: Ece Gamsiz D. , Shah Lipa K. , Devalapally Harikrishna , Amiji Mansoor M. , Carrier Rebecca L. 
Published: May 2008

AbstractModeling the influence of a technology such as nanoparticle systems on drug delivery is beneficial in rational formulation design. While there are many studies showing drug delivery enhancement by nanoparticles, the literature provides little guidance regarding when nanoparticles are useful for delivery of a given drug. A model was developed predicting intracellular drug concentration in cultured cells dosed with nanoparticles. The model considered drug release from nanoparticles as well as drug and nanoparticle uptake by the cells as the key system processes. Mathematical expressions for these key processes were determined using experiments in which each process occurred in isolation. In these experiments, intracellular delivery of saquinavir, a low solubility drug dosed as a formulation of poly(ethylene oxide)‐modified poly(epsilon‐ caprolactone) (PEO–PCL) nanoparticles, was studied in THP‐1 human monocyte/macrophage (Mo/Mac) cells. The model accurately predicted the enhancement in intracellular concentration when drug was administered in nanoparticles compared to aqueous solution. This simple model highlights the importance of relative kinetics of nanoparticle uptake and drug release in determining overall enhancement of intracellular drug concentration when dosing with nanoparticles. Biotechnol. Bioeng. © 2008 Wiley Periodicals, Inc.
Synthesis and Transfection Activity of New Cationic Phosphoramidate Lipids: High Efficiency of an Imidazolium Derivative
Authors: Mével Mathieu , Breuzard Gilles , Yaouanc Jean‐Jacques , Clément Jean‐Claude , Lehn Pierre , Pichon Chantal , Jaffrès Paul‐Alain , Midoux Patrick 
Published: May 2008

AbstractIn an effort to enhance the gene‐transfer efficiencies of cationic lipids and to decrease their toxicities, a series of new phosphoramidate lipids with chemical similarity to cell membrane phospholipids was synthesised. These lipids contained various cationic headgroups, such as arginine methyl ester, lysine methyl ester, homoarginine methyl ester, ethylenediamine, diaminopropane, guanidinium and imidazolium. Their transfection abilities, either alone or with the co‐lipid DOPE, were evaluated in HEK293–T7 cells. We found that imidazolium lipophosphoramidate7 a/DOPE lipoplexes gave the most efficient transfection with low toxicity (15 %). The luciferase activity was 100 times higher than that obtained with DOTAP/DOPE lipoplexes. The size,ζpotential, pDNA–liposome interactions and cellular uptakes of the lipoplexes were determined. No definitive correlation between theζpotential values and the transfection efficiencies could be established, but the uptake of lipoplexes by the cells was correlated with their final transfection efficiencies. Our results show that imidazolium phosphoramidate lipids constitute a potential new class of cationic lipids for gene transfer.
13C Direct‐detection biomolecular NMR
Authors: Bermel Wolfgang , Felli Isabella C. , Kümmerle Rainer , Pierattelli Roberta 
Published: May 2008

AbstractCarbon‐13 direct‐detection NMR is becoming increasingly used to complement 1H‐detected experiments in biomolecular applications. Here we describe the novel aspects that were addressed to convert 13C direct‐detection into a useful routinely applicable tool, a selection of the most useful 13C direct‐detection protonless NMR experiments and how they can be exploited for the study of proteins. © 2008 Wiley Periodicals, Inc. Concepts Magn Reson Part A 32A: 183–200, 2008.
Determination of Some Heavy Metal Ions with a Carbon Paste Electrode Modified by Poly(glycidylmethacrylate‐methylmethacrylate‐divinylbenzene) Microspheres Functionalized by 2‐Aminothiazole
Authors: Şar Erdem , Berber Hale , Aşçı Bürge , Cankurtaran Hüsnü 
Published: May 2008

AbstractA carbon paste electrode modified with 2‐aminothiazole functionalized poly(glycidylmethacrylate‐methylmethacrylate‐divinylbenzene) microspheres was used for trace determination of mercury, copper and lead ions. After the open‐circuit accumulation of the heavy metal ions onto the electrode, the sensitive anodic stripping peaks were obtained by square wave anodic stripping voltammetry (SWASV)). Many parameters such as the composition of the paste, pH, preconcentration time, effective potential scan rate and stirring rate influence the response of the measurement. The procedures were optimized for most sensitive and reliable determinations of the desired species. For a 10‐min preconcentration time in synthetic solutions at optimum instrumental and experimental conditions, the detection limit (LOD) was 12.3, 2.8 and 4.5 μg L−1 for mercury, copper and lead, respectively. The limits of detection may be enhanced by increasing the preconcentration time. For example, LOD of mercury and copper was 4.9 and 1.0 μg L−1 for fifteen minutes preconcentration time. The sensitivity may also considered to be increased by using a more suitable electrode composition targeting the more conductive electrode with lesser amount of modified polymer for sub‐μg L−1 levels of heavy metal ions. The optimized method was successfully applied to the determination of copper in tap water and waste water samples by means of standard addition procedure. The copper content found was comparable with the certified concentration of the waste water sample. The calibration plots for mercury and lead spiked real samples were also drawn.
Resting in peace or noise: Scanner background noise suppresses default‐mode network
Authors: Gaab Nadine , Gabrieli John D.E. , Glover Gary H. 
Published: May 2008

AbstractStudies have identified specific brain regions that increase activation during rest relative to attention‐demanding tasks; these regions subserve the “default mode of brain function”. Most of these studies have been conducted in the presence of scanner background noise (SBN). This noise has been shown to lead to altered attentional demands, and thus may modulate the default‐mode network. Twelve subjects were examined during a rest condition that was contrasted with an auditory task. Words were presented either with SBN employing a conventional acquisition or without SBN using a sparse sampling approach. The number of experimental and resting trials was equated between the designs. Selecting the images in the condition with SBN that corresponded in time with the images in the condition without SBN made a direct comparison of the default‐mode network (rest contrasted with active task) possible. There was typical activation of the default‐mode network during rest versus task for both designs. However, SBN suppressed major components of the default‐mode network, including medial prefrontal cortex, posterior cingulate, and precuneus. Our results suggest that the default mode of brain function differs when assessed in the presence compared to the absence of scanner noise, with the presence of scanner noise perhaps adding attentional demands that diminish activation changes between rest and task in a nonlinear way within the default network. Further studies are needed to clarify whether the use of a sparse sampling technique might enhance clinical utilities that have been proposed for analysis of the default‐mode network. Hum Brain Mapp 2008. © 2008 Wiley‐Liss, Inc.
Murine cirrhosis induces hepatocyte epithelial mesenchymal transition and alterations in survival signaling pathways
Authors: Nitta Takashi , Kim Jae-Sung , Mohuczy Dagmara , Behrns Kevin E. 
Published: May 2008

Abstract

Hepatocytes that reside in a chronically-injured liver have altered growth responses compared to hepatocytes in normal liver. Transforming growth factor beta (TGFβ) is upregulated in the cirrhotic liver, and cirrhotic hepatocytes, unlike normal hepatocytes exposed to this cytokine, exhibit decreased apoptosis. In fetal hepatocytes, TGFβ also induces epithelial-mesenchymal transition (EMT) and signaling changes in cell survival pathways. Here, chronic murine liver injury was induced by twice-weekly carbon tetrachloride administration for 8 weeks. Normal liver-derived hepatocytes (NLDH) and cirrhotic liver-derived hepatocytes (CLDH) were examined for EMT and the small mothers against decapentaplegic homolog (Smad), phosphatidylinositol-3-kinase (PI3K/Akt), and mitogen activated protein kinase (MAPK) pathways were investigated. Immunofluorescence imaging of cirrhotic livers demonstrated increased vimentin expression, which was confirmed by immunoblot analysis.

In vitro

, CLDH exhibited increased vimentin and type 1 collagen expression within cellular extensions consistent with EMT. Treatment with TGFβ augmented the EMT response in CLDH. In contrast, untreated NLDH did not display features of EMT but responded to TGFβ with increased vimentin expression and EMT characteristics. In response to PI3K/Akt inhibition, CLDH had decreased basal and insulin-stimulated p-Akt expression and decreased apoptosis compared to NLDH. In both NLDH and CLDH, vimentin expression was dependent on PI3K/Akt activity. CLDH demonstrated increased basal p-extracellular signal-regulated kinase expression that was independent of Smad and PI3K/Akt signaling. Inhibition of the MAPK pathway produced a marked increase in CLDH apoptosis.

Conclusion:

CLDH have increased vimentin and type 1 collagen expression and morphologic features consistent with EMT. In addition, compared to NLDH, the cellular signaling phenotype of CLDH changes from a MAPK-independent pathway to a MAPK-dependent cell survival pathway. These findings may have clinical implications for chemoprevention of hepatocellular carcinoma in the cirrhotic liver. (Hepatology 2008.)
Integrated water assessment model for water budgeting under future development scenarios in Qiantang River basin of China
Authors: Mu Jianxin , Khan Shahbaz , Gao Zhanyi 
Published: May 2008

AbstractSince conjunctive water use for agriculture is turning out to be a major environmental challenge in some river basins, there is an urgent need to quantify future water availability and water demand to identify whether there is a surplus or deficit of water. This is of great importance in developing water management plans for a basin or a state. In this paper, the Basin‐wide Holistic Integrated Water Assessment (BHIWA) model developed at the International Commission on Irrigation and Drainage (ICID) was used in an attempt to simulate the water balance of the study basin, the Qiantang River basin in China, as well as to analyse the impacts of land and water use on return flows of this basin. The model was run on a monthly basis, and was calibrated by comparing the calculated and observed data. Furthermore, the BHIWA model was applied to simulate historic conditions of the basin dating back to 1980 and for future scenarios to analyse the effects of water policies and multiple demands on water resources. The results calculated from this model indicated how the model could be a useful tool for basin‐level integrated water assessment, particularly in small river basins. Copyright © 2008 John Wiley & Sons, Ltd.
Placenta accreta in the first trimester of pregnancy: Sonographic findings
Authors: Wong Hong Soo , Zuccollo Jane , Tait John , Pringle, Kevin Craig 
Published: May 2008

AbstractIn a case of histologically confirmed placenta increta, decidual protrusion into the myometrium was observed sonographically at 6 weeks' gestation, corresponding to placental protrusion from a disrupted placental–uterine wall interface seen in the later part of the first and second trimester. It is hypothesized that the histologic finding of decidual scarcity in placenta accreta is not a cause but rather an end result of the recruitment of trophoblasts across the decidual–placental interface in a maternal attempt at healing and/or repair in the presence of uterine injury, disease, or malformation that accounts for the associated factors and course of the condition. © 2008 Wiley Periodicals, Inc. J Clin Ultrasound, 2009
Interactive compact device modelling using Qucs equation‐defined devices
Authors: Jahn S. , Brinson M. E. 
Published: May 2008

AbstractRecent trends in compact device modelling and circuit simulation suggest a growing movement towards standardization of Verilog‐A as a vehicle for semiconductor device specification and model interchange among commercial and open source simulators. This paper introduces a nonlinear equation‐defined device (EDD) characterized by current, voltage and charge equations with a similar syntax to Verilog‐A. The EDD has been implemented in Qucs and used extensively as a central feature in an interactive modelling system that allows straightforward prototyping of compact device models prior to translation into Verilog‐A. To illustrate the properties and the use of the Qucs EDD a number of examples centred on well‐known SPICE models are described. Copyright © 2008 John Wiley & Sons, Ltd.
Synchronous and metachronous cancers in patients with gastric cancer
Authors: Eom Bang Wool , Lee Hyuk‐Joon , Yoo Moon‐Won , Cho Jae Jin , Kim Woo Ho , Yang Han‐Kwang , Lee Kuhn Uk 
Published: May 2008

AbstractBackground and ObjectivesThe purpose of this study is to investigate characteristics of synchronous and metachronous cancer in gastric cancer and to suggest appropriate methods of treatment management.MethodsWe reviewed 4,593 patients who underwent operations for gastric cancer at Seoul National University Hospital from 1999 to 2005. We selected those patients who had also been diagnosed with another primary cancer and classified patients into three groups according to the date of detection of another primary cancer. We analyzed their clinicopathological features.ResultsThe incidence of synchronous or metachronous cancer in addition to gastric cancer was 3.4%. The most common another primary cancer was colorectal cancer (20.1%), followed by lung cancer and liver cancer. The majority of synchronous cancers were operated on at the same time as gastric cancer. Eighty‐five percent of the synchronous group and 45% of the post‐metachronous group were detected by a routine checkup, without prior symptoms. There was no postoperative mortality and the overall 5‐year survival rate was 69.4%.ConclusionSynchronous cancer should be considered in the preoperative workup and combined resection should be applied whenever possible. Periodic examination for metachronous cancer is necessary during the postoperative period. J. Surg. Oncol. 2008;98:106–110. © 2008 Wiley‐Liss, Inc.
Polyacrylamide‐based material for electrospun humidity‐resistant, water‐soluble nanofilters
Authors: Vetcher Alexandre A. , Gearheart Ryan , Morozov Victor N. 
Published: May 2008

AbstractA new approach for the collection of aerosol particles is described in which the particles are first collected on a water‐soluble filter and then liberated into an aqueous solution. The filter was manufactured by electrospinning a polyacrylamide (PAA) gel solution containing 2,2′‐(bisacrylamino) diethyl disulfide (BAC) cross‐links after gel dissolution in a water solution of β‐mercaptoethanol. The morphology of the P(AA–BAC) nanofibers was characterized using atomic force microscopy (AFM) and optical microscopy. The filters were characterized for their ability to capture aerosol particles, their stability at high humidity, and their ability to release captured particles. Copyright © 2008 John Wiley & Sons, Ltd.
Measurement of cerebrospinal fluid protein is unnecessary in children with leukemia
Authors: Barber Ashley , Lovato James , Hill Garick , McLean Thomas W. 
Published: May 2008

AbstractTo determine the incidence and importance of abnormal cerebrospinal fluid (CSF) protein in children with acute leukemia, we performed a retrospective chart review. On 160 pediatric patients a total of 2,172 LPs were performed (median per patient = 15; range 1–38). Overall, 314 (14%) of CSF protein measurements were abnormal: 141 (7%) were abnormally low (<15 mg/dL) and 158 (7%) were abnormally high (>45 mg/dL). In no case did an abnormal CSF protein impact patient management. We conclude that routine measurement of CSF protein is not indicated in children with acute leukemia. Pediatr Blood Cancer 2008;51:428–430. © 2008 Wiley‐Liss, Inc.
Proteomic analysis of proteins associated with body mass and length in yellow perch, Perca flavescens
Authors: Reddish John Mark , St‐Pierre Normand , Nichols Andy , Green‐Church Kari , Wick Macdonald 
Published: May 2008

AbstractThe goal of commercial yellow perch aquaculture is to increase muscle mass which leads to increased profitability. The accumulation and degradation of muscle‐specific gene products underlies the variability in body mass (BM) and length observed in pond‐cultured yellow perch. Our objective was to apply a combination of statistical and proteomic technologies to identify intact and/or proteolytic fragments of muscle specific gene products involved in muscle growth in yellow perch. Seventy yellow perch randomly selected at 10, 12, 16, 20, and 26 wk of age were euthanized; BM and length were measured and a muscle sample taken. Muscle proteins were resolved using 5–20% gradient SDS‐PAGE, stained with SYPRO® Ruby and analyzed using TotalLab™ software. Data were analyzed using stepwise multiple regression with the dependent variables, BM and length and proportional OD of each band in a sample as a potential regressor. Eight bands associated with BM (R2 = 0.84) and nine bands with length (R2 = 0.85) were detected. Protein sequencing by nano‐LC/MS/MS identified 20 proteins/peptides associated with BM and length. These results contribute the identification of gene products and/or proteolytic fragments associated with muscle growth in yellow perch.
Proteomic analyses of Fusarium graminearum grown under mycotoxin‐inducing conditions
Authors: Taylor Rebecca D. , Saparno Audrey , Blackwell Barbara , Anoop Valar , Gleddie Steve , Tinker Nicholas A. , Harris Linda J. 
Published: May 2008

AbstractNon‐gel‐based quantitative proteomics technology was used to profile protein expression differences when Fusarium graminearum was induced to produce trichothecenes in vitro. As F. graminearum synthesizes and secretes trichothecenes early in the cereal host invasion process, we hypothesized that proteins contributing to infection would also be induced under conditions favouring mycotoxin synthesis. Protein samples were extracted from three biological replicates of a time course study and subjected to iTRAQ (isobaric tags for relative and absolute quantification) analysis. Statistical analysis of a filtered dataset of 435 proteins revealed 130 F. graminearum proteins that exhibited significant changes in expression, of which 72 were upregulated relative to their level at the initial phase of the time course. There was good agreement between upregulated proteins identified by 2‐D PAGE/MS/MS and iTRAQ. RT‐PCR and northern hybridization confirmed that genes encoding proteins which were upregulated based on iTRAQ were also transcriptionally active under mycotoxin producing conditions. Numerous candidate pathogenicity proteins were identified using this technique. These will provide leads in the search for mechanisms and markers of host invasion and novel antifungal targets.
Overhauser field‐induced electron transport through weakly coupled double quantum dots
Authors: Iñarrea Jesús , MacDonald Allan H. , Lopez‐Monis Carlos , Platero Gloria 
Published: May 2008

AbstractIn this work the tunneling current through a weakly coupled double quantum dot in an external magnetic field is analyzed. We propose a model which includes Hyperfine interaction. The time evolution for electronic charge occupations and for the nuclei polarizations in each dot is obtained by means of rate equations which are self‐consistently solved.We analyze the current in the spin blockade region as a function of magnetic field and observe hysteretic behavior for magnetic fields corresponding to the crossings between triplet and singlet states. Bistability is also produced for the induced nuclei spin polarizations within each quantum dot. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Testing monotonicity over graph products
Authors: Halevy Shirley , Kushilevitz Eyal 
Published: May 2008

AbstractWe consider the problem of monotonicity testing over graph products. Monotonicity testing is one of the central problems studied in the field of property testing. We present a testing approach that enables us to use known monotonicity testers for given graphs G1, G2, to test monotonicity over their product G1 × G2. Such an approach of reducing monotonicity testing over a graph product to monotonicity testing over the original graphs, has been previously used in the special case of monotonicity testing over [n]d for a limited type of testers; in this article, we show that this approach can be applied to allow modular design of testers in many interesting cases: this approach works whenever the functions are boolean, and also in certain cases for functions with a general range. We demonstrate the usefulness of our results by showing how a careful use of this approach improves the query complexity of known testers. Specifically, based on our results, we provide a new analysis for the known tester for [n]d which significantly improves its query complexity analysis in the low‐dimensional case. For example, when d = O(1), we reduce the best known query complexity from O(log 2n/ε) to O(log n/ε). © 2008 Wiley Periodicals, Inc. Random Struct. Alg., 2008