bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electrochemical Study of Chitosan‐SiO2‐MWNT Composite Electrodes for the Fabrication of Cholesterol Biosensors
Authors: Tiwari Ashutosh , Gong Shaoqin 
Published: September 2008

AbstractWe report a novel composite electrode made of chitosan‐SiO2‐multiwall carbon nanotube (CHIT‐SiO2‐MWNT) composite coated on the indium‐tin oxide (ITO) glass substrate. Cholesterol oxidase (ChOx) was covalently immobilized on the CHIT‐SiO2‐MWNT/ITO electrode that resulted in a ChOx/CHIT‐SiO2‐MWNT/ITO cholesterolactive bioelectrode. The CHIT‐SiO2‐MWNT/ITO and ChOx/CHIT‐SiO2‐MWNT/ITO electrodes were characterized with Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The influence of various parameters was investigated, including the applied potential, pH of the medium, and the concentration of the enzyme on the performance of the biosensor. The cholesterol bioelectrode exhibited a sensitivity of 3.4 nA/ mgdL−1 with a response time of five seconds. The biosensor using ChOx/CHIT‐SiO2‐MWNT/ITO as the working electrode retained its original response after being stored for six months. The biosensor using ChOx/CHIT‐SiO2‐MWNT/ITO as the working electrode showed a linear current response to the cholesterol concentration in the range of 50–650 mg/dL.
Electrochemical and Electrocatalytic Properties of Imidazole Analogues of the Redox Cofactor Pyrroloquinoline Quinone
Authors: Lumibao Claudine Y. , Tillekeratne L. M. Viranga , Kirchhoff Jon R. , Fouchard David M. D. , Hudson Richard A. 
Published: September 2008

AbstractThe electrochemical and electrocatalytic properties of two synthetic imidazole analogues of the redox cofactor pyrroloquinoline quinone (PQQ) were evaluated. Cyclic voltammetry measurements as a function of pH indicated that both 4,5‐dihydro‐4,5‐dioxo‐1H‐imidazolo[5,4‐f]quinoline‐7,9‐dicarboxylic acid (1) and 4,5‐dihydro‐4,5‐dioxo‐2‐methyl‐1H‐imidazolo[5,4‐f]quinoline‐7,9‐dicarboxylic acid (2) undergo a reversible reduction of theo‐quinone moiety below pH 8 with potentials slightly more positive than those observed for PQQ. Upon incorporation into a polypyrrole membrane on the tip of a glassy carbon electrode,1and2exhibited electrocatalytic properties sufficient for the indirect amperometric detection of cysteine. The response for cysteine was linear up to 1 mM over a wide pH range. Detection limits (S/N=3) were in the μM range and dependent on the solution pH. Interference from redox active species such as dopamine and uric acid were minimized by the pH‐dependent redox potentials of1and2and thus the ability to tune the detection potential.
Amperometric Detection and Quantification of 8‐Hydroxy‐2′‐deoxyguanosine (8‐OHdG) Using Dendrimer Modified Electrodes
Authors: Gutiérrez Alejandro , Osegueda Soraya , Gutiérrez‐Granados Silvia , Alatorre Alejandro , García Ma. Guadalupe , Godínez Luis A. 
Published: September 2008

Abstract8‐Hydroxy‐2′‐deoxyguanosine (8‐OHdG) detection by high performance liquid chromatography (HPLC) with amperometric detection was studied using a Au electrode modified with different dendrimer based thin films. Gold electrode is thiol‐modified, forming self‐assembled monolayers on which different generation PAMAM dendrimers with terminal functional groups COOH and NH2 have been attached using peptidic bonds. Results obtained in synthetic samples show low limits of detection and quantification for 8‐OHdG (1.2×10−9 and 3.7×10−9 M respectively), with matrix interference elimination, thus avoiding sample pretreatment. Best results are obtained with electrodes modified with aliphatic amino thiols and 3.5 and 4.5 generation carboxylated dendrimers (Au/AET/DG3.5 and Au/AET/DG4.5), demonstrating that these materials constitute a good alternative for 8‐OHdG determination in biological fluids.
Incorporating spatially variable bottom stress and Coriolis force into 2D, a posteriori, unstructured mesh generation for shallow water models
Authors: Parrish D. Michael , Hagen Scott C. 
Published: September 2008

AbstractAn enhanced version of our localized truncation error analysis with complex derivatives (LTEA−CD ) a posteriori approach to computing target element sizes for tidal, shallow water flow, LTEA+CD , is applied to the Western North Atlantic Tidal model domain. The LTEA + CD method utilizes localized truncation error estimates of the shallow water momentum equations and builds upon LTEA and LTEA−CD‐based techniques by including: (1) velocity fields from a nonlinear simulation with complete constituent forcing; (2) spatially variable bottom stress; and (3) Coriolis force. Use of complex derivatives in this case results in a simple truncation error expression, and the ability to compute localized truncation errors using difference equations that employ only seven to eight computational points. The compact difference molecules allow the computation of truncation error estimates and target element sizes throughout the domain, including along the boundary; this fact, along with inclusion of locally variable bottom stress and Coriolis force, constitute significant advancements beyond the capabilities of LTEA. The goal of LTEA + CD is to drive the truncation error to a more uniform, domain‐wide value by adjusting element sizes (we apply LTEA + CD by re‐meshing the entire domain, not by moving nodes). We find that LTEA + CD can produce a mesh that is comprised of fewer nodes and elements than an initial high‐resolution mesh while performing as well as the initial mesh when considering the resynthesized tidal signals (elevations). Copyright © 2008 John Wiley & Sons, Ltd.
Performance of a Glucose/O2 Enzymatic Biofuel Cell Containing a Mediated Melanocarpus albomyces Laccase Cathode in a Physiological Buffer
Authors: Kavanagh P. , Boland S. , Jenkins P. , Leech D. 
Published: September 2008

AbstractWe report on the performance of a prototype glucose/O2 biofuel cell in a physiological buffer. The cell consists of cathode based on Melanocarpus albomyces laccase (with a reported T1 copper redox potential of + 0.26 V vs. Ag/AgCl) co‐immobilised with an osmium redox polymer mediating film on glassy carbon (GC) separated by a Nafion 117 membrane from a GC anode in anolyte of glucose oxidase, N,N,N′,N′‐tetramethyl‐p‐phenylenediamine (TMPD) as a mediator, all immersed in pH 7.4 phosphate buffer solution containing 0.15 M NaCl and dissolved oxygen, thermostated at 37 °C, mimicking physiological conditions. Two osmium redox polymers are employed for cathodic mediation: [Os(2,2′‐bipyridine)2(polyvinylimidazole)10Cl]+/2+ (E°′ 0.22 V vs. Ag/AgCl) and [Os(4,4′‐dichloro‐2,2′‐bipyridine)2(polyvinylimidazole)10Cl]+/2+ (E°′ 0.35 V vs. Ag/AgCl). Power outputs of 52 μW cm–2 at 0.21 V and 17 μW cm–2 at 0.34 V were obtained for assembled fuel cells containing the respective redox polymer‐mediated laccase cathodes, illustrating the increased power obtained as a result of higher biocatalytic efficiency using a redox polymer with redox potential tailored for the enzyme.
Kinetics of Anode Reactions for a Yeast‐Catalysed Microbial Fuel Cell
Authors: Ganguli R. , Dunn B. S. 
Published: September 2008

AbstractChronoamperometric investigations with rotating disc electrodes (RDEs) were used to characterise the anodic half‐cell of yeast powered microbial fuel cells using methylene blue (MB) as a mediator. Both convection and mediator adsorption were shown to affect the anodic current. A microbe–mediator limited reaction model was developed and shown to agree well with the experimental data. A power density of ∼150 μW cm–2 was achieved in a full cell, which represented a significant increase from prior reports on yeast‐catalysed fuel cells. The increased power density was enabled by using high mediator concentrations and by controlling the mediator adsorption.
Palliative radiation therapy for head and neck cancer: Toward an optimal fractionation scheme
Authors: Chen Allen M. , Vaughan Andrew , Narayan Samir , Vijayakumar Srinivasan 
Published: September 2008

AbstractBackground.To analyze the efficacy of various fractionation schedules for the palliation of head and neck cancer with radiation therapy.Methods.Sixty patients completed palliative irradiation to primary head and neck sites. The most commonly used fractionation regimen was the one previously described by the Radiation Therapy Oncology Group (RTOG) protocol 85‐02 and was designed to deliver 440 cGy using 370 cGy fractionation, administered twice a day for 2 consecutive days at 2‐ to 3‐week intervals for 3 total cycles.Results.The rates of palliative response were 83%, 77%, 67%, 86%, and 60% among those treated using the RTOG regimen, 7000 cGy/35 fractions, 3000 cGy/10 fractions, 3750 cGy/15 fractions, and 2000 cGy/5 fractions, respectively (p = .42). Nine percent (2/23) of those treated with the RTOG regimen developed grade 3+ toxicity compared with 37% among those treated with other schedules (p = .01).Conclusion.Although all of the analyzed schedules were effective at providing palliation, the RTOG 85‐02 regimen was associated with less toxicity. © 2008 Wiley Periodicals, Inc. Head Neck, 2008
Regulation of IAPs gene family by interleukin‐1α and Epstein‐Barr virus in nasopharyngeal carcinoma
Authors: Chua Huey‐Huey , Yeh Te‐Huei , Wang Ying‐Piao , Sheen Tzung‐Shiahn , Shew Jin‐Yuh , Huang Yu‐Tzu , Tsai Ching‐Hwa 
Published: September 2008

AbstractBackground.Inhibitors of apoptosis proteins (IAPs), which counteract apoptosis by potently inhibiting caspase activation, are promising targets of new anti‐tumor therapy. However, their roles in the pathogenesis of nasopharyngeal carcinoma (NPC), an Epstein‐Barr virus (EBV)‐associated carcinoma, are not fully understood. Herein, we investigated the expression and regulation of IAPs in NPC.Methods and Results.Using real‐time quantitative polymerase chain reaction (PCR) analysis, we found that among the IAPs family only the transcription of survivin, HIAP‐1, and HIAP‐2 was consistently up‐regulated in NPC and metastatic NPC tissues. Immunohistochemical staining showed that their proteins were more predominantly expressed in tumor cells nests. Noteworthy, these IAPs were upregulated by interleukin‐1α stimulation or EBV infection, and subsequently resulted in triggering rapid proliferation of NPC verified by strong Ki‐67 staining.Conclusion.Survivin, HIAP‐1, and HIAP‐2 were distinctly upregulated in NPC, suggesting they may play significant roles in NPC tumorigenesis and serve as tumor markers with prognostic and therapeutic implications. © 2008 Wiley Periodicals, Inc. Head Neck, 2008
Biochemotherapy in patients with advanced head and neck mucosal melanoma
Authors: Bartell Holly L. , Bedikian Agop Y. , Papadopoulos Nicholas E. , Dett Tina K. , Ballo Matthew T. , Myers Jeffrey N. , Hwu Patrick , Kim Kevin B. 
Published: September 2008

AbstractBackground.No systemic therapy regimen has been recognized as effective for metastatic mucosal melanoma of the head and neck. We retrospectively analyzed the effectiveness of biochemotherapy in patients with advanced head and neck mucosal melanoma.Methods.We evaluated the medical records of 15 patients at our institution who had received various biochemotherapy regimens for advanced head and neck mucosal melanoma.Results.After a median follow‐up duration of 13 months, 3 patients (20%) had partial response, and 4 patients (27%) had complete response. The median time to disease progression for all 15 patients was 10 months. The median overall survival duration for all patients was 22 months.Conclusions.Although this was a small study, our results, especially the high complete response and overall response rates, indicate that biochemotherapy for advanced head and neck mucosal melanoma should be considered as a systemic treatment option for patients with this aggressive malignancy. © 2008 Wiley Periodicals, Inc. Head Neck, 2008
Esthesioneuroblastoma: The Princess Margaret Hospital experience
Authors: Bachar Gideon , Goldstein David P. , Shah Manish , Tandon Asheesh , Ringash Jolie , Pond Gregory , Gullane Patrick J. , Perez‐Ordonez Bayardo , Gilbert Ralph W. , Brown Dale H. , Gentili Fred , O'Sullivan Brian , Irish Jonathan C. 
Published: September 2008

AbstractBackground.Esthesioneuroblastoma is rare. The aim of the study was to review our experience and to evaluate the staging system and treatment that best correlates with the patient outcome.Methods.Thirty‐nine patients were identified between 1972 and 2006.Results.At presentation 10% had cervical metastases. None had distant metastasis. Five were treated with surgery, 2 with chemotherapy, 1 with radiotherapy, and 30 with surgery and radiation. Local disease control was 82.6% at 5 years. Recurrence was seen in 33% with local and regional disease recurrence at 15% and 18%, respectively. The 5‐ and 10‐year overall survival rates were 87.9% and 69.2%, respectively. Dulguerov classification correlated most closely to survival and recurrence.Conclusions.Dulguerov classification best correlates with the patient's outcome. A combined approach is the preferred treatment. It makes no difference whether radiotherapy is given pre or postsurgical resection. Recurrence can occur even 15 years after treatment. Therefore, long‐term follow‐up is essential. © 2008 Wiley Periodicals, Inc. Head Neck, 2008
Distant metastases after transoral laser microsurgery for laryngeal and hypopharyngeal squamous cell carcinoma
Authors: Caballero Miguel , Vilaseca Isabel , Bernal‐Sprekelsen Manuel , Guilemany Jose M. , Moragas Miguel , Blanch Jose Luís 
Published: September 2008

AbstractBackground.Transoral CO2 laser microsurgery (TLM) resection of laryngeal–hypopharyngeal squamous cell carcinomas has become a standard procedure. The objective was to evaluate whether there is a relationship between TLM and a higher incidence of distant metastases.Methods.We conducted a retrospective analysis of 340 consecutive patients with laryngeal or hypopharyngeal squamous cell carcinoma treated with TLM.Results.Distant metastases occurred in 24 of 340 (7.1%) patients. The mean time of distant metastases diagnosis was 19.1 months (range, 1–41) postsurgery. Univariate study demonstrated an association with alcoholism (p = .008), tumor site (p<.001), grade of differentiation (p = .032), stage (p<.001), tumor classification (T; p = .001), node involvement (N; p<.001), extracapsular node spread (p<.001), and positive surgical margin (p = .004). In multivariate logistic regression analysis, location (sinus piriform: OR = 15.37, p = .025), node involvement (N2: OR = 7.36, p = .003; N3: OR = 19.28, p = .027), and the affected surgical margin (OR 5.32; p = .005) predicted an increased likelihood of distant metastases.Conclusions.Development of distant metastases after TLM in patients with squamous cell carcinoma depends mainly on the tumor site, the presence of metastatic lymph node disease, and the margin status after resection. © 2008 Wiley Periodicals, Inc. Head Neck, 2008
The impact of land use change and check‐dams on catchment sediment yield
Authors: Boix‐Fayos Carolina , de Vente Joris , Martínez‐Mena María , Barberá Gonzalo G. , Castillo Víctor 
Published: September 2008

AbstractExtensive land use changes have occurred in many areas of SE Spain as a result of reforestation and the abandonment of agricultural activities. Parallel to this the Spanish Administration spends large funds on hydrological control works to reduce erosion and sediment transport. However, it remains untested how these large land use changes affect the erosion processes at the catchment scale and if the hydrological control works efficiently reduce sediment export. A combination of field work, mapping and modelling was used to test the influence of land use scenarios with and without sediment control structures (check‐dams) on sediment yield at the catchment scale. The study catchment is located in SE Spain and suffered important land use changes, increasing the forest cover 3‐fold and decreasing the agricultural land 2·5‐fold from 1956 to 1997. In addition 58 check‐dams were constructed in the catchment in the 1970s accompanying reforestation works.The erosion model WATEM‐SEDEM was applied using six land use scenarios: land use in 1956, 1981 and 1997, each with and without check‐dams. Calibration of the model provided a model efficiency of 0·84 for absolute sediment yield. Model application showed that in a scenario without check dams, the land use changes between 1956 and 1997 caused a progressive decrease in sediment yield of 54%. In a scenario without land use changes but with check‐dams, about 77% of the sediment yield was retained behind the dams. Check‐dams can be efficient sediment control measures, but with a short‐lived effect. They have important side‐effects, such as inducing channel erosion downstream. While also having side‐effects, land use changes can have important long‐term effects on sediment yield. The application of either land use changes (i.e. reforestation) or check‐dams to control sediment yield depends on the objective of the management and the specific environmental conditions of each area. Copyright © 2008 John Wiley & Sons, Ltd.
Effects of 2003 wildfires on stream chemistry in Glacier National Park, Montana
Authors: Mast M. Alisa , Clow David W. 
Published: September 2008

AbstractChanges in stream chemistry were studied for 4 years following large wildfires that burned in Glacier National Park during the summer of 2003. Burned and unburned drainages were monitored from December 2003 through August 2007 for streamflow, major constituents, nutrients, and suspended sediment following the fires. Stream‐water nitrate concentrations showed the greatest response to fire, increasing up to tenfold above those in the unburned drainage just prior to the first post‐fire snowmelt season. Concentrations in winter base flow remained elevated during the entire study period, whereas concentrations during the growing season returned to background levels after two snowmelt seasons. Annual export of total nitrogen from the burned drainage ranged from 1·53 to 3·23 kg ha−1 yr−1 compared with 1·01 to 1·39 kg ha−1 yr−1 from the unburned drainage and exceeded atmospheric inputs for the first two post‐fire water years. Fire appeared to have minimal long‐term effects on other nutrients, dissolved organic carbon, and major constituents with the exception of sulfate and chloride, which showed increased concentrations for 2 years following the fire. There was little evidence that fire affected suspended‐sediment concentrations in the burned drainage. Sediment yields in subalpine streams may be less affected by fire than in lower elevation streams because of the slow release rate of water during spring snowmelt. Published in 2008 by John Wiley & Sons, Ltd.
Analysis of the water content in an unconfined aquifer with a partially penetrated pumping well
Authors: Chen Jiann‐Mou 
Published: September 2008

AbstractMost methods developed to represent water flow phenomena in an unconfined aquifer with a fully penetrated pumping well are either numerical, such as the well‐known FEMWTER model, or experimental; analytical models of a partially penetrated pumping well are rare. This study employs the linearized Richards equation as the governing equation, with the aid of Fourier Integral Transformation, to obtain an analytical solution of the water content distribution in an unconfined aquifer with a partially penetrated pumping well. The results from this study could serve to substantiate in some sense results from numerical models. In addition, the theory developed herein can be modified to simulate a vacuum‐pressured pumping well since it is derived by considering, among others, the location and length of a well screen with fluxes. Copyright © 2008 John Wiley & Sons, Ltd.
Bone marrow stroma cells regulate TIEG1 expression in acute lymphoblastic leukemia cells: Role of TGFβ/BMP‐6 and TIEG1 in chemotherapy escape
Authors: Døsen‐Dahl Guri , Munthe Else , Nygren Marit Kveine , Stubberud Heidi , Hystad Marit E. , Rian Edith 
Published: September 2008

AbstractThe bone marrow microenvironment regulates early B lymphopoiesis and protects leukemia cells against chemotherapy treatment, thus the microenvironment may serve as a sanctuary site for these cells. Yet, few factors that contribute to this process are known. We have explored the role of transforming growth factor β (TGFβ) and bone morphogenetic protein‐6 (BMP‐6) and one target gene, TGFβ inducible early gene 1 (TIEG1), in the communication between stroma cells and acute lymphoblastic leukemia (ALL) cell lines and their escape from chemotherapy. Here, we have demonstrated TIEG1 expression in both normal B progenitor cells and ALL cells, which increased rapidly upon TGFβ and BMP‐6 treatment. Stimulation with TGFβ or BMP‐6, as well as overexpression of TIEG1 inhibited proliferation. Furthermore, interaction with stroma cells induced TIEG1 expression in ALL cells, inhibited their proliferation and protected the cells against chemotherapeutic treatment. Similarly, treatment with TGFβ or BMP‐6, as well as overexpression of TIEG1, protected ALL cells against chemotherapy‐induced cell death. These data suggest that TGFβ and BMP‐6 in the bone marrow microenvironment allow leukemia cells to escape therapy. Further, the data indicate that TIEG1 might be involved in mediating this effect from the microenvironment onto the leukemia cells. © 2008 Wiley‐Liss, Inc.
Genetic polymorphisms in the MMP‐7 gene and breast cancer survival
Authors: Beeghly‐Fadiel Alicia , Shu Xiao‐ou , Long Jirong , Li Chun , Cai Qiuyin , Cai Hui , Gao Yu‐Tang , Zheng Wei 
Published: September 2008

AbstractMatrix metalloproteinase‐7 (MMP‐7) is a small secreted proteolytic enzyme with broad substrate specificity. Its expression has been shown to be associated with tumor invasion, metastasis and survival for a variety of cancers. We systematically evaluated single nucleotide polymorphisms (SNPs) in MMP‐7 in relation to breast cancer survival in a large follow‐up study. Included were 1,079 breast cancer cases that were recruited from 1996 to 1998 and followed for a median of 7.1 years as part of the Shanghai Breast Cancer Study (SBCS). Eleven SNPs, including 2 known functional promoter SNPs, were analyzed using the Affymetrix Targeted Genotyping System. Associations with survival were evaluated by Cox proportional hazards regression and Kaplan‐Meier functions. Statistically significant associations with disease‐free and/or overall survival (OS) were found for 5 polymorphisms; these associations were explained primarily by 2 SNPs (rs11568818 and rs11225297) that were in high linkage disequilibrium (LD) with the others. Patients homozygous for the rs11568818 rare allele (G) had a significantly worse prognosis (OS HR: 6.7, 95% CI: 2.4–18.6) than patients homozygous for the common allele (A). Significantly improved survival was seen for patients with the rs11225297 T allele, and this association occurred in a dose‐response manner; patients with AT (OS HR: 0.7, 95% CI: 0.5–0.9) and TT (OS HR: 0.3, 95% CI: 0.1–0.8) fared better than patients with AA (p‐value for trend: 0.001). Thus, common MMP‐7 genetic polymorphisms were found to be significant determinants of survival among Chinese women with breast cancer. © 2008 Wiley‐Liss, Inc.