bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modeling the role of working memory and episodic memory in behavioral tasks
Authors: Zilli Eric A. , Hasselmo Michael E. 
Published: November 2007

AbstractThe mechanisms of goal‐directed behavior have been studied using reinforcement learning theory, but these theoretical techniques have not often been used to address the role of memory systems in performing behavioral tasks. This work addresses this shortcoming by providing a way in which working memory (WM) and episodic memory may be included in the reinforcement learning framework, then simulating the successful acquisition and performance of six behavioral tasks, drawn from or inspired by the rat experimental literature, that require WM or episodic memory for correct performance. With no delay imposed during the tasks, simulations with WM can solve all of the tasks at above the chance level. When a delay is imposed, simulations with both episodic memory and WM can solve all of the tasks except a disambiguation of odor sequences task. © 2007 Wiley‐Liss, Inc.
The potential of different ANN techniques in evapotranspiration modelling
Authors: Kisi Ozgur 
Published: November 2007

AbstractThe potential of three different artificial neural network (ANN) techniques, the multi‐layer perceptrons (MLPs), radial basis neural networks (RBNNs) and generalized regression neural networks (GRNNs), in modelling of reference evapotranspiration (ET0) is investigated in this paper. Various daily climatic data, that is, solar radiation, air temperature, relative humidity and wind speed from two stations, Pomona and Santa Monica, in Los Angeles, USA, are used as inputs to the ANN techniques so as to estimate ET0 obtained using the FAO‐56 Penman–Monteith (PM) equation. In the first part of the study, a comparison is made between the estimates provided by the MLP, RBNN and GRNN and those of the following empirical models: The California Irrigation Management Information System (CIMIS) Penman (1985), Hargreaves (1985) and Ritchie (1990). In this part of the study, the empirical models are calibrated using the standard FAO‐56 PM ET0 values. The estimates of the ANN techniques are also compared with those of the calibrated empirical models. Mean square errors, mean absolute errors and determination coefficient statistics are used as comparing criteria for the evaluation of the models' performances. Based on the comparisons, it is found that the MLP and RBNN techniques could be employed successfully in modelling the ET0 process. In the second part of the study, the potential of ANN techniques and the empirical methods in ET0 estimation using nearby station data is investigated. Among the models, the calibrated Hargreaves model is found to perform better than the others. Copyright © 2007 John Wiley & Sons, Ltd.
Identification and determination of coumateralyl and coumafuryl in animal tissues by high‐performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry
Authors: Jin Mi‐cong , Xu Guo‐zhang , Ren Yi‐ping , Chen Xiao‐hong , Xu Xiao‐ming 
Published: November 2007

AbstractA high‐performance liquid chromatographic–tandem mass spectrometric (HPLC‐MS‐MS) method was developed and validated to determine simultaneously coumafuryl and coumateralyl in animal tissues using warfarin as an internal standard (IS). Animal tissue samples were extracted with ethyl acetate and cleaned by Oasis HLB solid‐phase extraction (SPE) cartridges. After pretreatment, the separation was performed on a XDB C18 column with an isocratic mobile phase of acetic acid–ammonium acetate (5 mmol l−1, pH = 4.5)/methanol (30:70, v/v). Detection was carried out on a mass spectrometer by negative electrospray ionization (ESI) in multiple reaction monitoring (MRM) mode. The calibration curves were linear (r2 > 0.998) in the concentration range 0.75–100.0 ng g−1 with a lower limit of quantification of 0.75 ng g−1 for coumafuryl, and 0.5 ng g−1 for coumateralyl in liver and kidney samples. Intra‐day and inter‐day relative standard deviations (RSDs) were less than 8.6% and 10.9%, respectively. Recoveries of coumafuryl and coumateralyl were in the range 81.5–89.5%. The developed assay has been applied to the determination of trace residues of coumafuryl and coumateralyl in animal tissues to investigate suspected poisoning of human and animals. Copyright © 2007 John Wiley & Sons, Ltd.
Characterization of the physicochemical, antimicrobial, and drug release properties of thermoresponsive hydrogel copolymers designed for medical device applications
Authors: Jones David S. , Lorimer Colin P. , McCoy Colin P. , Gorman Sean P. 
Published: November 2007

AbstractIn this study, a series of hydrogels was synthesized by free radical polymerization, namely poly(2‐(hydroxyethyl)methacrylate) (pHEMA), poly(4‐(hydroxybutyl)methacrylate) (pHBMA), poly(6‐(hydroxyhexyl)methacrylate) (pHHMA), and copolymers composed of N‐isopropylacrylamide (NIPAA), methacrylic acid (MA), NIPAA, and the above monomers. The surface, mechanical, and swelling properties (at 20 and 37°C, pH 6) of the polymers were determined using dynamic contact angle analysis, tensile analysis, and thermogravimetry, respectively. The Tg and lower critical solution temperatures (LCST) were determined using modulated DSC and oscillatory rheometry, respectively. Drug loading of the hydrogels with chlorhexidine diacetate was performed by immersion in a drug solution at 20°C (<LCST) and subsequent characterization of the drug release and antimicrobial properties performed at 20 and 37°C. The composition of the hydrogels directly affected the advancing contact angle, mechanical properties, and swelling. Thermoresponsive behavior was only observed with hydrogels composed of HEMA, NIPAA, MA, and NIPAA in which pulsatile drug release was obtained by elevating the temperature from below to above the LCST. A greater mass and enhanced pulsatile release of drug, with the associated greater antimicrobial properties (an 108 reduction in viability of Staphylococcus epidermidis in 15 min), was associated with poly(NIPAA‐co‐HEMA, 1:1). It is suggested that the pulsatile drug release and favorable antimicrobial and mechanical properties of candidate hydrogels, particularly poly(HEMA‐co‐NIPAA), offer promise as thermoresponsive, antimicrobial biomaterials that may be used as wound dressings, medical implants, or coatings of medical devices. Furthermore, it is suggested that drug loading may be effectively performed in situ by lowering the temperature of the device/dressing. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008
N‐acetylcysteine stimulates osteoblastic differentiation of mouse calvarial cells
Authors: Jun Ji Hae , Lee Sun‐Hwan , Kwak Han Bok , Lee Zang Hee , Seo Sang‐Beum , Woo Kyung Mi , Ryoo Hyun‐Mo , Kim Gwan‐Shik , Baek Jeong‐Hwa 
Published: November 2007

AbstractEstrogen deficiency causes osteoporosis via increased generation of reactive oxygen species (ROS), and thus, antioxidants may prove to be the effective therapeutic candidates. We examined the effects of the antioxidant N‐acetylcysteine (NAC) on osteoblastic differentiation in mouse calvarial cells. NAC (10–30 mM) enhanced alkaline phosphatase activity, mRNA expression of osteoblast differentiation‐associated genes and mineralized nodule formation. It also increased expression of bone morphogenetic proteins‐2, ‐4, and ‐7. The osteogenic activity of NAC was partially reduced by inhibition of glutathione synthesis. Since caffeic acid phenethyl ester did not stimulate osteoblast differentiation, it is unlikely that ROS scavenging activity of NAC is sufficient for osteogenic activity. We observed that NAC suppressed small GTPase RhoA activity and activation of RhoA by Pasteurella multocida toxin suppressed the osteogenic activity of NAC. These results suggest that NAC might exert its osteogenic activity via increased glutathione synthesis and inhibition of RhoA activation. J. Cell. Biochem. 103: 1246–1255, 2008. © 2007 Wiley‐Liss, Inc.
B‐Myb regulates the A2B adenosine receptor in vascular smooth muscle cells
Authors: St. Hilaire Cynthia , Yang Dan , Schreiber Barbara M. , Ravid Katya 
Published: November 2007

AbstractThe A2B adenosine receptor (A2BAR) has been described to control various vascular functions, including inhibition of smooth muscle cell proliferation. Here, we sought to understand the regulation of A2BAR gene expression in aortic vascular smooth muscle cells (VSMCs), with a focus on the proliferation phase. Assays with A2BAR‐β‐gal aortic VSMCs, in which the endogenous A2BAR gene promoter drives the expression of prokaryotic β‐galactosidase (β‐gal) instead of the endogenous A2BAR gene, show that β‐gal expression is upregulated when the cells are induced to exit from cell cycle arrest. Similarly, the level of A2BAR mRNA is upregulated in proliferating primary aortic VSMCs. In search of related mechanisms, it was noted that the A2BAR gene promoter contains several putative binding sites for the proliferation‐inducing transcription factor, B‐Myb. Using a clone of the 5′ region upstream of the mouse A2BAR gene linked to a reporter gene, B‐Myb site deletion mutants were generated. It was determined that B‐Myb upregulates the A2BAR gene promoter, and specific promoter binding sites were identified as functional. In accordance, B‐Myb also elevates endogenous A2BAR mRNA and receptor activity, and this activity decreases cell proliferation. Our data are novel in that they show that this proliferation‐inhibiting A2BAR is itself an inducible receptor regulated by B‐Myb. J. Cell. Biochem. 103: 1962–1974, 2007. © 2007 Wiley‐Liss, Inc.
Hesperetin, a bioflavonoid, inhibits rat aortic vascular smooth muscle cells proliferation by arresting cell cycle
Authors: Jin Yong‐Ri , Han Xiang‐Hua , Zhang Yong‐He , Lee Jung‐Jin , Lim Yong , Kim Tack‐Joong , Yoo Hwan‐Soo , Yun Yeo‐Pyo 
Published: November 2007

AbstractDiet can be one of the most important factors that influence risks for cardiovascular diseases. Hesperetin, a flavonoid present in grapefruits and oranges, is one candidate that may benefit the cardiovascular system. In this study, we have investigated the effect of hesperetin on the platelet‐derived growth factor (PDGF)‐BB‐induced proliferation of primary cultured rat aortic vascular smooth muscle cells (VSMCs). Hesperetin significantly inhibited 50 ng/ml PDGF‐BB‐induced rat aortic VSMCs proliferation and [3H]‐thymidine incorporation into DNA at concentrations of 5, 25, 50, and 100 µM. In accordance with these findings, hesperetin revealed blocking of the PDGF‐BB‐inducible progression through G0/G1 to S phase of the cell cycle in synchronized cells. Western blot showed that hesperetin inhibited not only phosphorylation of retinoblastoma protein (pRb) and expressions of cyclin A, cyclin D, cyclin E, cyclin‐dependent kinase 2 (CDK2) as well as proliferating cell nuclear antigen (PCNA) protein, but also downregulation of cyclin‐dependent kinase inhibitor (CKI) p27kip1, while did not affect CKI p21cip1, p16INK4, p53, and CDK4 expressions as well as early signaling transductions such as PDGF beta‐receptor, extracellular signal‐regulated kinase (ERK) 1/2, Akt, p38, and JNK phosphorylation. These results suggest that hesperetin inhibits PDGF‐BB‐induced rat aortic VSMCs proliferation via G0/G1 arrest in association with modulation of the expression or activation of cell‐cycle regulatory proteins, which may contribute to the beneficial effect of grapefruits and oranges on cardiovascular system. J. Cell. Biochem. 104: 1–14, 2008. © 2007 Wiley‐Liss, Inc.
β‐catenin mediates alteration in cell proliferation, motility and invasion of prostate cancer cells by differential expression of E‐cadherin and protein kinase D1
Authors: Syed Viqar , Mak Paul , Du Cheng , Balaji K.C. 
Published: November 2007

AbstractWe have previously demonstrated that Protein Kinase D1 (PKD1) interacts with E‐cadherin and is associated with altered cell aggregation and motility in prostate cancer (PC). Because both PKD1 and E‐cadherin are known to be dysregulated in PC, in this study we investigated the functional consequences of combined dysregulation of PKD1 and E‐cadherin using a panel of human PC cell lines. Gain and loss of function studies were carried out by either transfecting PC cells with full‐length E‐cadherin and/or PKD1 cDNA or by protein silencing by siRNAs, respectively. We studied major malignant phenotypic characteristics including cell proliferation, motility, and invasion at the cellular level, which were corroborated with appropriate changes in representative molecular markers. Down regulation or ectopic expression of either E‐cadherin or PKD1 significantly increased or decreased cell proliferation, motility, and invasion, respectively, and combined down regulation cumulatively influenced the effects. Loss of PKD1 or E‐cadherin expression was associated with increased expression of the pro‐survival molecular markers survivin, β‐catenin, cyclin‐D, and c‐myc, whereas overexpression of PKD1 and/or E‐cadherin resulted in an increase of caspases. The inhibitory effect of PKD1 and E‐cadherin on cell proliferation was rescued by coexpression with β‐catenin, suggesting that β‐catenin mediates the effect of proliferation by PKD1 and E‐cadherin. This study establishes the functional significance of combined dysregulation of PKD1 and E‐cadherin in PC and that their effect on cell growth is mediated by β‐catenin. J. Cell. Biochem. 104: 82–95, 2008. © 2007 Wiley‐Liss, Inc.
Extrinsic regulation of cardiomyocyte differentiation of embryonic stem cells
Authors: Chen Kang , Wu Liqun , Wang Zack Z. 
Published: November 2007

AbstractCardiovascular disease is one of leading causes of death throughout the U.S. and the world. The damage of cardiomyocytes resulting from ischemic injury is irreversible and leads to the development of progressive heart failure, which is characterized by the loss of functional cardiomyocytes. Because cardiomyocytes are unable to regenerate in the adult heart, cell‐based therapy of transplantation provides a potential alternative approach to replace damaged myocardial tissue and restore cardiac function. A major roadblock toward this goal is the lack of donor cells; therefore, it is urgent to identify the cardiovascular cells that are necessary for achieving cardiac muscle regeneration. Pluripotent embryonic stem (ES) cells have enormous potential as a source of therapeutic tissues, including cardiovascular cells; however, the regulatory elements mediating ES cell differentiation to cardiomyocytes are largely unknown. In this review, we will focus on extrinsic factors that play a role in regulating different stages of cardiomyocyte differentiation of ES cells. J. Cell. Biochem. 104: 119–128, 2008. © 2007 Wiley‐Liss, Inc.
From G0 to S phase: A view of the roles played by the retinoblastoma (Rb) family members in the Rb‐E2F pathway
Authors: Sun Ang , Bagella Luigi , Tutton Steven , Romano Gaetano , Giordano Antonio 
Published: November 2007

AbstractTumor suppressor pRb/p105, pRb/p107, and pRb2/p130 genes belong to the retinoblastoma (Rb) gene family. The members of the Rb gene family and the transcription factor E2F play an essential role in regulating cell cycle and, consequently, cell proliferation. This mini‐review describes the mechanisms by which Rb family members and E2F regulate cell cycle progression. J. Cell. Biochem. 102: 1400–1404, 2007. © 2007 Wiley‐Liss, Inc.
Zinc depletion efficiently inhibits pancreatic cancer cell growth by increasing the ratio of antiproliferative/proliferative genes
Authors: Donadelli M. , Dalla Pozza E. , Costanzo C. , Scupoli M.T. , Scarpa A. , Palmieri M. 
Published: November 2007

AbstractWe investigated the ability of the zinc chelator N,N,N′,N′‐tetrakis(2‐pyridylmethyl)ethylenediamine (TPEN) to reduce pancreatic cancer cell viability. TPEN was much more efficient to inhibit pancreatic adenocarcinoma cell growth than a panel of anti‐cancer drugs, including 5‐fluorouracil, irinotecan, cisplatin, edelfosine, trichostatin A, mitomycin C, and gemcitabine, the gold standard chemotherapeutic agent for pancreatic cancer. Moreover, TPEN showed a dose‐ and time‐dependent anti‐proliferative effect significantly higher on pancreatic cancer cells than on normal primary fibroblasts. This effect may be explained by a significantly higher zinc depletion by TPEN in pancreatic cancer cells as compared to fibroblasts. Cell viability reduction by TPEN was associated to both G1‐phase cell cycle arrest and apoptosis, and to the increased ratio of the expression level of cyclin‐Cdk inhibitor versus cyclin genes and apoptotic versus anti‐apoptotic genes. Finally, we show that apoptotic cell death induced by TPEN involved mitochondrial injury and caspase 3 and caspase 8 activation. In this study, we suggest that zinc depletion may be an efficient strategy in the treatment of pancreatic cancer because of its reduced antiproliferative effect on normal cells. J. Cell. Biochem. 104: 202–212, 2008. © 2007 Wiley‐Liss, Inc.
A survey on the existence ofG‐Designs
Authors: Adams Peter , Bryant Darryn , Buchanan Melinda 
Published: November 2007

AbstractAG‐design of ordernis a decomposition of the complete graph onnvertices into edge‐disjoint subgraphs isomorphic toG. We survey the current state of knowledge on the existence problem forG‐designs. This includes references to all the necessary designs and constructions, as well as a few new designs. © 2007 Wiley Periodicals, Inc. J Combin Designs 16: 373–410, 2008
Aqueous two‐phase extraction using thermoseparating copolymer: a new system for phenolic compounds removal from hemicelullosic hydrolysate
Authors: Hasmann Francislene A , Santos Valéria C , Gurpilhares Daniela B , Pessoa‐Junior Adalberto , Roberto Inês C 
Published: November 2007

AbstractBACKGROUND: The hydrolysis of hemicellulosic material can provide liquor with high xylose concentration (which can be used as a fermentation medium) and phenolic compounds (Phs), potentially immunostimulating compounds. However, these hydrolysates must be detoxified in order to remove the Phs that can act as inhibitors in bioconversions.RESULTS: Aqueous two‐phase systems composed of thermoseparating copolymers were used for rice straw hydrolysate detoxification. The hydrolysis process was able to promote chemical breakdown of 85% of the total hemicellulose content, 14% of the cellulose, and 2% of the lignin. The hydrolysate obtained contained 19.7 g L−1 of xylose and several phenolic compounds, such as vanillin, vanillic acid, ferullic acid, etc. The phenolics extraction was studied as a function of copolymer molar mass (1100 g mol−1, 2000 g mol−1 and 2800 g mol−1), their percentages (from 5% to 50%) and Phs initial concentration. Phenolic compounds extraction of around 80% was obtained under the following conditions: 20% (w/w) and 35% (w/w) copolymer 1100 g mol−1, 35% (w/w) copolymer 2000 g mol−1 and 35% (w/w) copolymer 2800 g mol−1 at 25 °C.CONCLUSIONS: The results demonstrated the viability of this method for the removal of Phs from rice straw hydrolysate, which has potential uses in bioconversion processes. Copyright © 2007 Society of Chemical Industry
A temperature‐gradient sensor for determining the activity of activated sludge
Authors: Park Soon‐Ung , Hur Won 
Published: November 2007

AbstractEfficient wastewater treatment requires monitoring of the biological activity of activated sludge. Its metabolic heat can be a critical indicator. Thus, a new method, measuring the temperature gradient between sludge sediment and the supernatant, is proposed for analyzing sludge. A prototype of the device was developed using an insulated cylinder with a series of thermistor sensors attached in parallel. Sedimentation of sludge in the lower part of the cylinder concentrated microorganisms, which produced more metabolic heat than the supernatant. The heat produced correlated well with the sludge concentration. The temperature profiles of each probe also enable real‐time monitoring of sludge settling. Extended operation of the sensor evaluates the sludge quality, such as metabolic sustainability and the time required for the sludge to float under anaerobic conditions. A temperature‐gradient sensor was implemented and its utility was confirmed by measuring the heat produced in sludge from a local wastewater plant. Copyright © 2007 Society of Chemical Industry
Oxidation of a laccase mediator ABTS as studied by ESI‐FTICR mass spectrometry
Authors: Marjasvaara Asse , Jänis Janne , Vainiotalo Pirjo 
Published: November 2007

AbstractThe oxidation reaction of a laccase mediator ABTS (2,2′‐azino‐bis(3‐ethylbenzothiazoline‐6‐sulfonic acid) was studied by electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI‐FTICRMS). Oxidation products of ABTS were measured after reaction times that varied from a few minutes up to several days and both positive and negative ionization modes were employed. Exact mass measurements and collision‐induced dissociation (CID) experiments were used to characterize the structures of the ions formed. After reacting with Trametes versicolor laccase (TvL), the radical cation form of ABTS was the main product observed by the positive ionization mode. Negative ionization mode experiments revealed that a degradation product from ABTS was formed. Copyright © 2007 John Wiley & Sons, Ltd.
Prognostic significance of the ratio between metastatic and dissected lymph nodes (n ratio) in patients with advanced gastric cancer
Authors: Saito Hiroaki , Fukumoto Yoji , Osaki Tomohiro , Yamada Yoshinori , Fukuda Kenji , Tatebe Shigeru , Tsujitani Shunichi , Ikeguchi Masahide 
Published: November 2007

AbstractBackground and ObjectivesTo determine the prognostic significance of the ratio between metastatic and dissected lymph nodes (n ratio) in gastric cancer patients.MethodsWe retrospectively reviewed 777 advanced gastric cancer patients who had undergone curative gastrectomy at our hospital.ResultsThe n ratio was significantly greater in cases with a large tumor, undifferentiated tumor, lymphatic vessel invasion, or blood vessel invasion. Furthermore, the n ratio was significantly correlated with the depth of invasion, level of lymph node metastasis, and number of lymph node metastases. The prognosis for gastric cancer patients correlated well with the n ratio. Multivariate analysis indicated that the n ratio, but not the number of lymph node metastases, was an independent prognostic indicator. Moreover, the n ratio was an independent prognostic factor in N1, N2, and N3 patients defined by the Japanese Classification of Gastric Cancer (JCGC).ConclusionsThe n ratio is useful for evaluating the status of lymph node metastasis in gastric cancer. Therefore, the addition of the n ratio to the N (nodal) category defined by the JCGC may be a useful strategy in the N‐staging classification of gastric cancer. J. Surg. Oncol. 2008;97:132–135. © 2007 Wiley‐Liss, Inc.