bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of grafted maleic anhydride content and recyclability of dynamically cured maleated natural rubber/polypropylene blends
Authors: Nakason Charoen , Saiwari Sitisaiyidah 
Published: September 2008

AbstractMaleated natural rubbers (MNRs) were prepared using various levels of maleic anhydride (MA) at 4, 6, 8, 10, and 12 phr. Dynamically cured 60/40 MNR/PP blends with phenolic‐modified polypropylene (Ph‐PP) compatibilizer at a loading level of 5 wt % of PP were prepared by melt mixing process using sulfur vulcanization system. The influence of the level of MA on properties of the thermoplastic vulcanizates (TPVs) was studied. It was found that the mixing torque, apparent shear stress, shear viscosity, tensile strength, and hardness properties increased with increasing levels of the MA or grafted succinic anhydride groups in the MNR molecules. This is attributed to an increase in chemical interaction and reaction between methylol groups in the Ph‐PP molecules and polar functional groups in the MNR molecules upon increasing levels of the grafted succinic anhydride groups. As a consequence, compatibilizing block copolymers of MNR and PP blocks were formed. The block copolymers were capable of compatibilizing with MNR and PP blend components via the respective blocks. Recyclability of the MNR/PP TPVs was also studied. It was found that, after processing through a number of cycles by injection molding and extrusion processing, the TPV exhibited marginal decreases in mechanical properties. This corresponded to slightly increasing size of the dispersed vulcanized rubber domains. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
A multi‐attribute trade‐off approach for advancing the management of marine wildlife tourism: a quantitative assessment of heterogeneous visitor preferences
Authors: Semeniuk Christina A.D. , Haider Wolfgang , Beardmore Ben , Rothley Kristina D. 
Published: September 2008

Abstract
Wildlife tourism can be prone to unmitigated development to promote visitor satisfaction that is all too often progressed at the cost of ecological integrity. A manager is thus faced with the dual task of enhancing the tourist experience and protecting the wildlife species. Accordingly, this mandate requires research into how tourists would respond to proposed wildlife‐management plans.
This study examines the heterogeneity of tourist preferences for wildlife management at a stingray‐feeding attraction in the Cayman Islands, using a latent class stated preference choice model. A sample of visitors to Stingray City Sandbar (SCS) evaluated hypothetical wildlife viewing experiences in a discrete choice experiment. Its scenarios were characterized by seven attributes such as animal‐feeding and handling rules, ecological outcomes, social crowding, and management cost (defined as a conservation access fee).
The latent class segmentation identified two groups in the population: approximately 68% preferred the implementation of fairly strict management rules, while the other 32% valued more the maintenance of status quo with its intensive human — wildlife interactions. Despite the differences between the ‘pro‐management’ and the ‘pro‐current’ segments, both exhibited a preference for the continuation of feeding and handling the stingrays (albeit at different levels of intensity) suggesting that one effective way to implement any management actions is to alter the promotional and marketing strategies for SCS. Other survey questions on trip experience, conservation values, and socio‐demographics were used to define these classes further, with the main distinguishing trait being the level of concern for potential impacts occurring at SCS. The discrepancies between the two segments became most obvious when calculating their respective market shares of support for alternative management strategies.
This approach to determining visitor preferences can help explain how the various segments will be affected by management options, and therefore can provide the basis for developing feasible strategies that will assist wildlife managers in maximizing tourist satisfaction while achieving wildlife‐protection goals.
Copyright © 2008 John Wiley & Sons, Ltd.
New Amides of 5‐(4‐Chlorobenzoyl)aminoorotic Acid: Their Synthesis and Biological Activity
Authors: Regiec Andrzej , Śpiewak Magdalena , Jasztold‐Howorko Ryszard , Miedzybrodzki Ryszard 
Published: September 2008

AbstractThe synthesis and in‐vitro biological evaluation of the amide series 4 of 5‐(4‐chlorobenzoyl)aminoorotic acid 2 are presented. The biological properties of a few 5‐(4‐chlorobenzoyl)amino‐2,6‐dihydroxy‐N‐substituted‐4‐pyrimidinecarboxamide derivatives 4 tested here were compared with those of the isosteric isothiazole derivative MR‐2/94 (5‐(4‐chlorobenzoyl)amino‐N‐(4‐chlorophenyl)‐3‐methyl‐4‐isothiazolecarboxamide), which possesses a strong immunosuppressive and anti‐inflammatory activity [1, 2], It must be suggested that replacement of the isothiazole by a pyrimidine core ring system resulted in considerable lowering of the anti‐inflammatory and immunotropic actions of the obtained amides. Physicochemical properties of 2‐(4‐chlorophenyl)‐6,8‐dihydroxy‐4H‐pyrimido[5,4‐d]‐1,3‐oxazin‐4‐on 3 are also briefly described.
Refined Docking as a Valuable Tool for Lead Optimization: Application to Histamine H3 Receptor Antagonists
Authors: Levoin Nicolas , Calmels Thierry , Poupardin‐Olivier Olivia , Labeeuw Olivier , Danvy Denis , Robert Philippe , Berrebi‐Bertrand Isabelle , Ganellin C. Robin , Schunack Walter , Stark Holger , Capet Marc 
Published: September 2008

AbstractDrug‐discovery projects frequently employ structure‐based information through protein modeling and ligand docking, and there is a plethora of reports relating successful use of them in virtual screening. Hit / lead optimization, which represents the next step and the longest for the medicinal chemist, is very rarely considered. This is not surprising because lead optimization is a much more complex task. Here, a homology model of the histamine H3 receptor was built and tested for its ability to discriminate ligands above a defined threshold of affinity. In addition, drug safety is also evaluated during lead optimization, and “antitargets” are studied. So, we have used the same benchmarking procedure with the HERG channel and CYP2D6 enzyme, for which a minimal affinity is strongly desired. For targets and antitargets, we report here an accuracy as high as at least 70%, for ligands being classified above or below the chosen threshold. Such a good result is beyond what could have been predicted, especially, since our test conditions were particularly stringent. First, we measured the accuracy by means of AUC of ROC plots, i. e. considering both false positive and false negatives. Second, we used as datasets extensive chemical libraries (nearly a thousand ligands for H3). All molecules considered were true H3 receptor ligands with moderate to high affinity (from μM to nM range). Third, the database is issued from concrete SAR (Bioprojet H3 BF2.649 library) and is not simply constituted by few active ligands buried in a chemical catalogue.
Synthesis and SAR Study of T‐Type Calcium Channel Blockers. Part II
Authors: Choe Yun Jeong , Seo Han Na , Jung Soo Yeon , Rhim Hyewhon , Kim Jungahn , Choo Dong Joon , Lee Jae Yeol 
Published: September 2008

Abstract3,4‐Dihydroquinazoline derivatives have been known to be the novel and potent T‐type calcium channel blockers. From a systematic variation of 3,4‐dihydroquinazoline derivative 5c (KYS05043), plausible SAR results were established. It was revealed that a 5‐(dimethylamino)pentylamino group at R1, a biphenyl group at R2, and a benzyl amido group at R3 in the 3,4‐dihydroquinazoline backbone are closely related with the channel selectivity (T/N‐type) as well as the potency based on the discovery of 6k (KYS05090).
Synthesis and Biochemical Characterization of New Phenothiazines and Related Drugs as MDR Reversal Agents
Authors: Schmidt Matthias , Teitge Marlen , Castillo Marianela E. , Brandt Tobias , Dobner Bodo , Langner Andreas 
Published: September 2008

AbstractChemotherapy is one of the most important methods in the treatment of cancer. However, development of drug resistance during chemotherapy is the leading cause of treatment failure and decreased survival in cancer patients. Multidrug resistance (MDR) is one of the extensively studied forms of drug resistance for more than 30 years. The members of ATP‐binding cassette protein family are responsible for multidrug resistance with P‐glycoprotein as most representative transporter. To overcome multidrug resistance, pharmacological modulation of the transporters by efflux pump inhibitors seem to be the first choice, but preclinical studies did not lead to clinical applications. Therefore, a systematical research for pharmacophor structures is a promising strategy to increase the efficacy of those drugs still influencing multidrug resistance. In this study a range of phenothiazine derivatives was synthesizied with systematical variation of three molecule domains. The biochemical determination of multidrug resistance reversal activity was achieved with the crystalviolet assay on LLC‐PK1/MDR1 cells. The results will be discussed considering of hypotheses in the literature directed to new structure‐acitivity relationships to overcome drug resistance in the future.
Further studies of the heat island associated with a small midwestern city
Authors: Buckley Patrick I. , Market Patrick S. , Lupo Anthony R. , Fox Neil 
Published: September 2008

AbstractRecently, the University of Missouri (UM) moved its SuomiNet station from the roof of a building near downtown Columbia, Missouri, USA, to the University's rural South Farm. Comparisons of Columbia Regional Airport (KCOU) data and SuomiNet data are presented both prior to and after the latter's relocation. Analysis reveals an elevation of mean temperature by ∼1.5 °C at the downtown location, but no difference between the more rural station and KCOU. These results show that the influence of the Columbia heat island does not extend to 7 km from the city center and that the present SuomiNet location is now more representative. Copyright © 2008 Royal Meteorological Society
Photo‐immobilization of biological components on gold‐coated chips for measurements using surface plasmon resonance (SPR) and a quartz crystal microbalance (QCM)
Authors: Tsuzuki Saki , Wada Akira , Ito Yoshihiro 
Published: September 2008

AbstractThe photo‐immobilization technique is useful for immobilization of various biomolecules on assorted material surfaces, independent of the organic functional groups that may be present. Here, we report a convenient new photo‐immobilization technique that was developed by combining a nonbiofouling polymer containing polyethylene glycol and a photoreactive crosslinker for surface plasmon resonance (SPR) and quartz crystal microbalance (QCM) measurements. By this method, nonspecific interactions were reduced and various types of molecules, bovine serum albumin, heparin, dsDNA, phosphatidylserine, Tobacco Mosaic Virus, and norfloxacine, were immobilized on an alkane thiol‐modified gold surface by a single method. The interactions of photo‐immobilized biomolecules and their corresponding antibodies were investigated by SPR and QCM. In addition, SPR imaging was possible using the present method. Biotechnol. Bioeng. 2009; 102: 700–707. © 2008 Wiley Periodicals, Inc.
Development of a denaturation/renaturation‐based production process for ferritin nanoparticles
Authors: Jääskeläinen Anu , Soukka Tero , Lamminmäki Urpo , Korpimäki Teemu , Virta Marko 
Published: September 2008

AbstractRecently, we presented a simple method for generating biological functional protein‐based nanoparticles that are ready for use as label agents in bioaffinity assays (Jääskeläinen et al., 2007 Small 3:1362–1367). In this process, the particle shell (ferritin protein) and binding molecules are conjugated via genetic fusion, and particles with binding capacity are produced in a single bacterial cultivation. Production is combined with simple, non‐chromatographic purification during which Europium ions are introduced into particles to serve as marker agents. Denaturation‐refolding has previously performed by means of pH changes. Here, we test urea as an alternative agent for denaturation, and examine techniques to improve refolding of the functional particles. Three different types of binding molecules were employed in our experiments: biotin carboxyl carrier protein (a small protein with 87 amino acids), single chain antibody fragment (a complex binding protein) and calmodulin‐binding peptide (27 amino acids). Urea was successfully utilized to generate functional particles with inherent binding activity and label function. Additionally, particle yield was effectively optimized by analyzing various refolding and bacterial production conditions. Our results clearly demonstrate that this simple biological method of producing functional ferritin‐based particles is flexible, and different types of binding moieties can be applied by adjusting the production conditions. Biotechnol. Bioeng. 2009;102: 1012–1024. © 2008 Wiley Periodicals, Inc.
Simultaneous determination of main taxoids in Taxus needles extracts by solid‐phase extraction‐high‐performance liquid chromatography with pentafluorophenyl column
Authors: Fu Yu‐Jie , Sun Rui , Zu Yuan‐Gang , Li Shuang‐Ming , Liu Wei , Efferth Thomas , Gu Cheng‐Bo , Zhang Lin , Luo Hao 
Published: September 2008

AbstractA simple and accurate RP‐HPLC method with pentafluorophenyl (PFP) column was developed for the simultaneous determination of six taxoids, i.e. paclitaxel, 10‐deacetylbaccatin III (10‐DAB III), 7‐xylosyl‐10‐deacetyltaxol (7‐xyl‐10‐DAT), 10‐deacetyltaxol (10‐DAT), cephalomannine and 7‐epi‐10‐deacetyltaxol (7‐epi‐10‐DAT), in the extracts from the needles of three Taxus species. The mobile phase consisted of acetonitrile (A) and water (B), and the extracts were separated using gradient elution program: 30% A at the first 7 min, and then ramped to 42% A at 8 min, held until 38 min. The developed method was validated with satisfactory precision (RSD < 2.61%), repeatability (RSD < 2.92%) and recovery (95.19–104.47%). The above taxoids in the extracts of Taxus cuspidata, T. chinensis and T. media were analyzed with the developed RP‐HPLC method, and the results showed that the contents of different taxoids in three mentioned species were distinct. Maximal amounts of 10‐DAB III, 7‐xyl‐10‐DAT and 7‐epi‐10‐DAT appeared in T. chinensis, while T. media possessed the highest content of 10‐DAT, cephalomannine and paclitaxel. The developed method is accurate and efficient. It can be reliably used in the improved determination of taxoids for the quality control of Taxus species. Copyright © 2008 John Wiley & Sons, Ltd.
Simultaneous determination of mifepristone and monodemethyl‐mifepristone in human plasma by liquid chromatography–tandem mass spectrometry method using levonorgestrel as an internal standard: application to a pharmacokinetic study
Authors: Tang Cheng , Bi Hui‐chang , Zhong Guo‐ping , Chen Xiao , Huang Zhi‐ying , Huang Min 
Published: September 2008

AbstractA rapid and sensitive liquid chromatography/tandem mass spectrometry (LC‐MS/MS) method was developed and validated to simultaneously determine mifepristone and monodemethyl‐mifepristone in human plasma using levonorgestrel as the internal standard (IS). After solid‐phase extraction of the plasma samples, mifepristone, monodemethyl‐mifepristone and the IS were subjected to LC‐MS/MS analysis using electro‐spray ionization (ESI) in the multiple reaction monitoring (MRM) mode. Chromatographic separation was performed on an XTERRA MS C18column (150 × 2.1 mm i.d., 5 µm). The method had a chromatographic run time of 4.5 min and linear calibration curves over the concentration ranges of 5–2000 ng/mL for mifepristone and monodemethyl‐mifepristone. The recoveries of the method were found to be 94.5–103.7% for mifepristone and 70.7–77.3% for monodemethyl‐mifepristone. The method had a lower limit of quantification (LLOQ) of 5.0 ng/mL and a lower limit of detection (LOD) of 1.0 ng/mL for both mifepristone and monodemethyl‐mifepristone. The intra‐ and inter‐batch precision was less than 15% for all quality control samples at concentrations of 10, 100 and 1000 ng/mL. These results indicate that the method was efficient with a short run time (4.5 min) and acceptable accuracy, precision and sensitivity. The validated LC‐MS/MS method was successfully used in a pharmacokinetic study in healthy female volunteers after oral administration of 25 mg mifepristone tablet. Copyright © 2008 John Wiley & Sons, Ltd.
Lipophilicity of some guaianolides isolated from two endemic subspecies of Amphoricarpos neumayeri (Asteraceae) from Montenegro
Authors: Atrrog Abubaker A. B. , Natić Maja , Tosti Tomislav , Milojković‐Opsenica Dušanka , Đorđević Iris , Tešević Vele , Jadranin Milka , Milosavljević Slobodan , Lazić Milan , Radulović Siniša , Tešić Živoslav 
Published: September 2008

AbstractIn this study 10 guaianolide‐type sesquiterpene γ‐lactones named amphoricarpolides, isolated from the aerial parts of two endemic subspecies of Amphoricarpos neumayeri (ssp. neumayeri and ssp. murbeckii Bošnjak), were investigated by means of reversed‐phase thin‐layer chromatography. Methanol–water and tetrahydrofuran–water binary mixtures were used as mobile phase in order to determine lipophilicity parameters R
and C0. Some of the investigated compounds were screened for their cytotoxic activity against HeLa and B16 cells. Chromatographically obtained lipophilicity parameters were correlated with calculated logP values and IC50 values. Principal component analysis identified the dominant pattern in the chromatographically obtained data. Copyright © 2008 John Wiley & Sons, Ltd.
High‐performance liquid chromatographic determination of creatine kinase activity influenced by methylglyoxal
Authors: Peng Xiaofang , Ma Jinyu , Cheng Ka‐Wing , Chen Bo , Chen Feng , Wang Mingfu 
Published: September 2008

AbstractProtein glycation has been implicated in the development of diabetic complications and other health disorders, which mainly arise from accumulation of advanced glycation endproducts (AGEs) in vivo. Methylglyoxal (MGO), a typical reactive intermediate carbonyl formed in early glycation process, can react non‐enzymatically with N‐terminal amino groups on proteins, leading to their inactivation and generation of detrimental AGEs. Recently, it was reported that activity of creatine kinase (CK, EC 2.7.3.2) could be reduced or even eliminated completely after incubation with MGO in vitro. CK activity is usually determined by conventional colorimetric assays. However, these methods are not appropriate for monitoring the influence of MGO on CK activity since MGO can also directly react with creatine, a substrate of CK. In this study, an efficient and much more accurate HPLC approach was established to investigate the effect of MGO on CK activity. Aminoguanidine was utilized to eliminate interference from the undesirable reaction between residual MGO and creatine. It was found that higher concentrations of MGO and longer incubation time for CK and MGO caused more pronounced reduction in CK activity. This HPLC method greatly facilitates acquisition of kinetic data about CK reaction and through further improvement it may be adopted to rapidly screen potential inhibitors of MGO‐induced glycation. Copyright © 2008 John Wiley & Sons, Ltd.
Measurement of xenobiotics in saliva: is saliva an attractive alternative matrix? Case studies and analytical perspectives
Authors: Mullangi Ramesh , Agrawal Shrutidevi , Srinivas Nuggehally R. 
Published: September 2008

AbstractThe use of saliva for measuring xenobiotic concentrations has been practiced for a number of years. While the use of saliva has been generally reserved for the analysis of diagnostic and forensic/toxicology samples, attempts have been made to further enhance the value of saliva as an alternate matrix to those of plasma and serum. It is understood that saliva represents a handy tool for therapeutic drug monitoring (TDM) as it offers certain distinctive advantages. This scope of this review encompasses the following: (a) a comprehensive view of saliva as an alternate matrix for either plasma or serum to understand the pharmacokinetic/pharmacodynamic (PK/PD) characteristics; (b) an account of the factors contributing to the observed variability in salivary monitoring; (c) a tabular compilation of diverse case studies of xenobitoics belonging to different therapeutic classes with emphasis on assay methodology and applicable analytical/biopharmaceutical/pharmacokinetic findings; (d) relevant thoughts on assay procedures as they relate to salivary monitoring; and (e) some representative case studies highlighting the new thinking on the use of saliva outside of traditional TDM. Overall, based on the review, saliva represents a valuable TDM tool for a number of xenobiotics. While parent compound and phase I metabolite(s) for many xenobiotics have been generally quantifiable in saliva, phase II metabolites have not generally been detected in saliva. Therefore saliva samples could also be used to answer some specific PK/PD questions during the drug development process, if applicable. However, the development and validation of the assay in saliva needs to be carried out carefully with particular focus on proper sample collection, processing and storage to ensure the stability of the xenobiotics and with the same rigor as applied to plasma, serum and urine matrices. Copyright © 2008 John Wiley & Sons, Ltd.
Determination of bergenin in human plasma after oral administration by HPLC‐MS/MS method and its pharmacokinetic study
Authors: Wang Jin , Wang Ben‐jie , Wei Chun‐min , Yuan Gui‐yan , Zhang Rui , Liu Hui , Zhang Xiu‐mei , Guo Rui‐chen 
Published: September 2008

AbstractA highly sensitive, simple and selective high‐performance liquid chromatography–tandem mass spectrometry (HPLC‐MS/MS) method was developed and applied to the determination of bergenin concentration in human plasma. Bergenin and the internal standard (IS) thiamphenicol in plasma were extracted with ethyl acetate, separated on a C18 reversed‐phase column, eluted with mobile phase of acetonitrile–water, ionized by negative ion pneumatically assisted electrospray and detected in the multi‐reaction monitoring mode using precursor → product ions of m/z 327.1 → 192 for bergenin and 354 → 185.1 for the IS, respectively. The linear range of the calibration curve for bergenin was 0.25–60 ng mL−1, with the lowest limit of quantification of 0.25 ng mL−1, and the intra/inter‐day relative standard deviation (RSD) was less than 10%. The method is suitable for the determination of low bergenin concentration in human plasma after therapeutic oral doses, and has been first and successfully used for its pharmacokinetic studies in healthy Chinese volunteers. Copyright © 2008 John Wiley & Sons, Ltd.