bluuebunny/crossref_metadata_2025_split huggingface dataset:
[76Br]BMK‐I‐152, a non‐peptide analogue for PET imaging of corticotropin‐releasing hormone type 1 receptor (CRHR1)
Authors: Lang L. , Ma Y. , Kim B. M. , Jagoda E. M. , Rice K. C. , Szajek L. P. , Contoreggi C. , Gold P. W. , Chrousos G. P. , Eckelman W. C. , Kiesewetter D. O. 
Published: July 2009

AbstractThe study of corticotropin‐releasing hormone is of significant interest in mental health. We have developed a radiobromination procedure for the preparation of [76Br]BMK‐I‐152, a high‐affinity corticotropin‐releasing hormone type 1 receptor antagonist. The radiobromination procedure resulted in the formation of two radiobrominated products from the same trialkyltin precursor. Utilizing the results of several reaction conditions and the chromatographic and mass spectral data obtained from Waters Acquity and Q‐TOF, we determined that both 3‐bromo and 4‐bromo isomers could be obtained. The authentic sample of the 3‐bromo isomer was prepared to confirm the identity of a previously unknown radioactive side product; affinity assays revealed that the 4‐bromo isomer had ∼70 times higher affinity than that of the 3‐bromo compound. By manipulation of reaction conditions, the individual products could be selected. Under no‐carrier‐added conditions at room temperature in aqueous acetonitrile, the major radioactive product (>80%) was identified as the 3‐[76Br]bromo‐4‐tributylstannyl analogue of BMK‐I‐152. The 4‐[76Br]bromo isomer accounted for less than 1% of the total activity. The 3‐[76Br]bromo BMK‐I‐152 could be obtained by treating this intermediate with trifluoroacetic acid to effect removal of the trialkyltin. If the radiobromination was conducted after first evaporating the water from the aqueous ammonium hydroxide solution of [76Br]bromide, the desired 4‐[76Br]bromo isomer was obtained with a 58% radiochemical yield. Copyright © 2009 John Wiley & Sons, Ltd.
Protein dynamics and conformational disorder in molecular recognition
Authors: Mittag Tanja , Kay Lewis E. , Forman‐Kay Julie D. 
Published: July 2009

AbstractRecognition requires protein flexibility because it facilitates conformational rearrangements and induced‐fit mechanisms upon target binding. Intrinsic disorder is an extreme on the continuous spectrum of possible protein dynamics and its role in recognition may seem counterintuitive. However, conformational disorder is widely found in many eukaryotic regulatory proteins involved in processes such as signal transduction and transcription. Disordered protein regions may in fact confer advantages over folded proteins in binding. Rapidly interconverting and diverse conformers may create mean electrostatic fields instead of presenting discrete charges. The resultant “polyelectrostatic” interactions allow for the utilization of post‐translational modifications as a means to change the net charge and thereby modify the electrostatic interaction of a disordered region. Plasticity of disordered protein states enables steric advantages over folded proteins and allows for unique binding configurations. Disorder may also have evolutionary advantages, as it facilitates alternative splicing, domain shuffling and protein modularity. As proteins exist in a continuous spectrum of disorder, so do their complexes. Indeed, disordered regions in complexes may control the degree of motion between domains, mask binding sites, be targets of post‐translational modifications, permit overlapping binding motifs, and enable transient binding of different binding partners, making them excellent candidates for signal integrators and explaining their prevalence in eukaryotic signaling pathways. “Dynamic” complexes arise if more than two transient protein interfaces are involved in complex formation of two binding partners in a dynamic equilibrium. “Disordered” complexes, in contrast, do not involve significant ordering of interacting protein segments but rely exclusively on transient contacts. The nature of these interactions is not well understood yet but advancements in the structural characterization of disordered states will help us gain insights into their function and their implications for health and disease. Copyright © 2009 John Wiley & Sons, Ltd.
Atomic force microscopy analysis of central nervous system cell morphology on silicon carbide and diamond substrates
Authors: Frewin C. L. , Jaroszeski M. , Weeber E. , Muffly K. E. , Kumar A. , Peters M. , Oliveros A. , Saddow S. E. 
Published: July 2009

AbstractBrain machine interface (BMI) devices offer a platform that can be used to assist people with extreme disabilities, such as amyotrophic lateral sclerosis (ALS) and Parkinson's disease. Silicon (Si) has been the material of choice used for the manufacture of BMI devices due to its mechanical strength, its electrical properties and multiple fabrication techniques; however, chronically implanted BMI devices have usually failed within months of implantation due to biocompatibility issues and the fact that Si does not withstand the harsh environment of the body. Single crystal cubic silicon carbide (3C‐SiC) and nanocrystalline diamond (NCD) are semiconductor materials that have previously shown good biocompatibility with skin and bone cells. Like Si, these materials have excellent physical characteristics, good electrical properties, but unlike Si, they are chemically inert. We have performed a study to evaluate the general biocompatibility levels of all of these materials through the use of in vitro techniques. H4 human neuroglioma and PC12 rat pheochromocytoma cell lines were used for the study, and polystyrene (PSt) and amorphous glass were used as controls or for morphological comparison. MTT [3‐(4,5‐Dimethylthiazol‐2‐Yl)‐2,5‐Diphenyltetrazolium Bromide] assays were performed to determine general cell viability with each substrate and atomic force microscopy (AFM) was used to quantify the general cell morphology on the substrate surface along with the substrate permissiveness to lamellipodia extension. 3C‐SiC was the only substrate tested to have good viability and superior lamellipodia permissiveness with both cell lines, while NCD showed a good level of viability with the neural H4 line but a poor viability with the PC12 line and lower permissiveness than 3C‐SiC. Explanations pertaining to the performance of each substrate with both cell lines are presented and discussed along with future work that must be performed to further evaluate specific cell reactions on these substrates. Copyright © 2009 John Wiley & Sons, Ltd.
Rainfall regime in Three Gorges area in China and the control factors
Authors: Fang Zhao , Hang Deng , Xinyi Zhao 
Published: July 2009

AbstractA set of daily precipitation data from 1958 to 2007 was analysed for the area in and around the Three Gorges Reservoir Region. Annual and monthly precipitation, number of rainy days (NRDs), precipitation intensity (INT), and seven indices of extreme precipitation and drought were examined. Correlation between circulation indices and climate parameters was analysed. Significant decreases were detected in spring, fall, winter and annual NRDs, while significant increases were found in precipitation INT. Inter‐decadal changes are obvious, it was wettest in the early 1980s, and dry in the first few years and after 1990. No significant changes are found in extreme precipitation/drought events, but a closer examination suggested they might become more frequent after 1980. Precipitation totals and days of extreme precipitation in a specific period were found to be negatively correlated with western North Pacific Monsoon Index (WNPMI); positively correlated with summer average of index of the ridge of western Pacific subtropical high; and positively correlated with summer average of index of INT of western Pacific subtropical high and the winter–summer difference of Tibetan Plateau (TP) index. These links were significant but not strong, which might manifest the characteristics of Three Gorges Area as a transition zone, where precipitation is influenced by multiple systems. Regional management should be more careful to adjust to these changes. Copyright © 2009 Royal Meteorological Society
Hierarchical Bayesian modelling of wind and sea surface temperature from the Portuguese coast
Authors: Lemos Ricardo T. , Sansó Bruno , Santos F. D. 
Published: July 2009

AbstractIn this work, we revisit a recent analysis that pointed to an overall relaxation of the Portuguese coastal upwelling system, between 1941 and 2000, and apply more elaborate statistical techniques to assess that evidence. Our goal is to fit a model for environmental variables that accommodate seasonal cycles, long‐term trends, short‐term fluctuations with some degree of autocorrelation, and cross‐correlations between measuring sites and variables. Reference cell coding is used to investigate similarities in behaviour among sites. Parameter estimation is performed in a single modelling step, thereby producing more reliable credibility intervals than previous studies. This is of special importance in the assessment of trend significance. We employ a Bayesian approach with a purposely developed Markov chain Monte Carlo method to explore the posterior distribution of the parameters. Our results substantiate most previous findings and provide new insight on the relationship between wind and sea surface temperature off the Portuguese coast. Copyright © 2009 Royal Meteorological Society
Hybrid silica polymeric monolith‐based in‐tube microextraction and CE for determination of bisphenol A in beverages
Authors: Hu Jiwei , Li Xuegang , Cai Yawen , Han Heyou 
Published: July 2009

AbstractOn‐line concentration techniques in capillary electrophoresis, including stacking and sweeping, have a weak tolerance towards complex real samples. A phenyl‐functionalized hybrid silica monolithic polymeric capillary column (id 530 μm) was prepared by in‐situ co‐condensation of phenyltriethoxysilane (PTES) and tetraethoxysilane (TEOS). In order to enhance the stability of a monolithic column within a wide‐bore capillary, a novel and simple frit‐preparation method for wide‐bore capillaries was first introduced by immobilizing a short length of capillary of suitable outer diameter at the end of the monolithic capillary column during condensation of the sol‐gel solution. The monolithic column was used for the extraction of bisphenol A (BPA) from cola samples, and the interfering compounds can be removed from the samples with 40% ACN solution (v/v) as eluent. The pretreated samples were further concentrated and separated using large‐volume stacking and sweeping micellar electrokinetic chromatography. The method was successfully applied to the determination of bisphenol A spiked in cola, yielding a detection limit of 1.8 ng/mL. Close correlation coefficients and acceptable method reproducibility were obtained for bisphenol A over a linear range of 0.005–0.200 μg/mL.
Extraction of genomic DNA using a new amino silica monolithic column
Authors: Liu Lijia , Yu Shengbing , Yang Shuixian , Zhou Ping , Hu Jiming , Zhang Yibing 
Published: July 2009

AbstractA new amino silica monolithic column was developed for DNA extraction in a miniaturized format. The monolithic column was prepared in situ by polymerization of tetraethoxysilane (TEOS) and N‐(β‐aminoethyl)‐γ‐aminopropylmethyldimethoxysilane (AEAPMDMS). DNA was loaded in 50 mM tris(hydroxylmethyl)aminomethane–EDTA buffer at pH 7.0 and eluted with 300 mM potassium phosphate solution at pH 10.0. Under optimal condition, a 6.0‐cm monolithic column provided a capacity of 56 ng DNA with an extraction efficiency of 71 ± 5.2% (X ± RSD). When the amino silica monolithic column was applied to extract genomic DNA from the whole blood of crucian carp, an extraction efficiency of 52 ± 5.6% (X ± RSD) was obtained by three extractions. Since the chaotropic‐based sample loading and organic solvent wash steps were avoided in this procedure, the purified DNA was suitable for downstream processes such as PCR. This amino silica monolithic column was demonstrated to allow rapid and efficient DNA purification in microscale.
On‐column titration and investigation of metal complex formation for aminopolycarboxylate functionalised monoliths using scanning contactless conductivity detection
Authors: Gillespie Eoin , Connolly Damian , Nesterenko Pavel N. , Paull Brett 
Published: July 2009

AbstractThe application of scanning capacitively coupled contactless conductivity detection (SC4D) for the determination of pH dependant behaviour of two aminopolycarboxylates immobilised onto the surface of a monolithic capillary column is described. The use of SC4D to visualise changes in conductivity of the discrete zones of functional groups within monolithic capillary columns allows for the effects of immobilisation on the physicochemical properties of zones to be compared to that of the functional group in solution. The perturbation of the pKa values of the functional groups can be attributed to the change in chemical environment experienced by the functional group through the presence of local hydrogen bonding and surface induced effects. These bonds, both between adjacent functional groups and with the monolithic polymethacrylate scaffold, result in a modification of the electron density on the functional group and therefore a change in pKa. Changes in the pKa of N‐(2‐acetamido)iminodiacetic acid (ADA) from 2.48 to 5.2 for one of the acidic protons, with little change in the pKa of the amine group, were observed, which correlates to similar changes in aggregated systems of aminopolycarboxylates. Similar results were obtained for the iminodiacetic acid (IDA) once immobilised onto the surface of the monolith. Furthermore, the ability to measure changes in the charge of such discrete zones of functional groups allows for the visualisation of complexation events occurring directly on‐column, where such complexes result in a change in charge of the functional group. This potentially useful technique is illustrated within for the formation of aminopolycarboxylate complexes with a selection of metal ions.
Tailored “Grafting‐From” Functionalization of Microfiltration Membrane Surface Photo‐Initiated by Immobilized Iniferter
Authors: He Dongming , Ulbricht Mathias 
Published: July 2009

AbstractSurface‐selective graft functionalization of hydrophilized poly(propylene) microfiltration membrane has been realized by two steps: (i) immobilization of dithiocarbamate group as iniferter and (ii) heterogeneous photo‐graft copolymerization controlled by this iniferter. Investigations regarding controllability of photo‐grafting were carried out with varied monomer concentration and UV‐irradiation time as well as cross‐linker monomer content by using ATR‐FTIR spectroscopy, scanning electron microscopy, water permeability, and measurements of pore size distribution. The developed grafting method exhibits high surface‐grafting selectivity and efficiency, uniform modification and high controllability over grafted layer thickness and (cross‐linked) architecture.magnified image
Free Radical Graft Copolymerization of Methyl Methacrylate onto Polyolefin Backbone: Kinetics Modeling through Model Compounds Approach
Authors: Badel Thierry , Beyou Emmanuel , Bounor‐Legaré Véronique , Chaumont Philippe , Flat Jean‐Jacques , Michel Alain 
Published: July 2009

AbstractThe grafting of poly(methyl methacrylate) (PMMA) from poly[ethylene‐co‐(1‐octene)] in the molten state by in situ radical polymerization of methyl methacrylate (MMA) was investigated through a kinetic modeling using a model compound approach. We resorted to pentadecane (C15H32) and 2,6,10,15,19,23‐hexamethyltetracosane (Squalane, C30H62) as models for both the copolymer ethylene and octene moieties. The attention was focused on the simulation of MMA conversion and PMMA average polymerization degree according to temperature, reaction time, and initiator ratio required for the polymerization of MMA in the presence of alkoxyl radicals and alkanes.magnified image
Use of Pristine Clay Platelets as a Suspension Stabilizer for the Synthesis of Poly(methyl methacrylate)/Clay Nanocomposites
Authors: Khatana Shyam , Dhibar Anup Kumar , Sinha Ray Suprakas , Khatua Bhanu Bhusan 
Published: July 2009

AbstractThe role of Na+‐mmt platelets as a stabilizer during the suspension polymerization of MMA is described. The addition of a small amount of Na+‐mmt into the system without suspension stabilizer results in the formation of spherical beads of PMMA/Na+‐mmt nanocomposites with uniform sizes, whereas in the presence of o‐mmt, it resulted in the formation of PMMA/o‐mmt composite clusters. FT‐IR spectroscopy reveals a strong interaction between the PMMA carbonyl groups with the clay surface in the PMMA/Na+‐mmt nanocomposite. DSC results indicate a significant increase in the glass transition temperature of PMMA in the PMMA/Na+‐mmt nanocomposite as compared to that of the PMMA/o‐mmt nanocomposite. The thermal stability of PMMA is also increased in the case of the PMMA/Na+‐mmt nanocomposite.magnified image
Quantification of climate for tourism in the northwest of Iran
Authors: Farajzadeh Hassan , Matzarakis Andreas 
Published: July 2009

AbstractTourism as a major sector of the global economy is influenced by weather and climate. At several travel destinations, climate represents a natural resource on which the tourism industry is predicated. Data covering the period 1985–2005 and from a dense network of 15 meteorological stations was used to compute the Physiologically Equivalent Temperature (PET) and ‘tourism climate index’ (TCI) in Northwest of Iran. The cities Maku, Ahar, Ardabil, Takab, Khoy, Ourimeh and Sarab have a summer peak distribution. Each of these locations has at least 1 month with a TCI score above 80: this level can be classified to be an ‘excellent’ tourism climate. The cities Maku, Ardabli and Takab have TCI above 90, an ‘ideal’ tourism climate for the summer months. Among these cities, Ardabil has the most favourable climatic conditions for tourist attractiveness in the summer. The cities Mahabad, Jolfa, Marageh, Sagez and Parsabad have a bimodal‐shoulder peak distribution.In addition, based on calculations of PET in Ourmieh Lake coast it is shown that the months June, July and August are lying in the comfortable class representing the most suitable months for tourism and tourist activities. Copyright © 2009 Royal Meteorological Society
Shallot and licorice constituent isoliquiritigenin arrests cell cycle progression and induces apoptosis through the induction of ATM/p53 and initiation of the mitochondrial system in human cervical carcinoma HeLa cells
Authors: Hsu Ya‐Ling , Chia Chun‐Chieh , Chen Ping‐Jye , Huang Su‐Er , Huang Soon‐Cen , Kuo Po‐Lin 
Published: July 2009

AbstractThis study is the first to investigate the anticancer effect of isoliquiritigenin (ISL) in human cervical carcinoma HeLa cells. The results reveal that ISL inhibits HeLa cells by blocking cell cycle progression in the G2/M phase and inducing apoptosis. Blockade of cell cycle is associated with increased activation of ataxia telangiectasia‐mutated (ATM). Activation of ATM by ISL phosphorylated p53 at Serine15, resulting in increased stability of p53 by decreasing p53 and murine double minute‐2 (MDM2) interaction. In addition, ISL‐mediated G2/M phase arrest was also associated with decreases in the amounts of cyclin B, cyclin A, cdc2, and cdc25C, and increases in the phosphorylation of Chk2, cdc25C, and cdc2. The specific ATM inhibitor caffeine significantly decreased ISL‐mediated G2/M arrest by inhibiting the phosphorylation of p53 (Serine15) and Chk2. ISL induced apoptotic cell death is associated with changes in the expression of Bax and Bak, decreasing levels of Bcl‐2 and Bcl‐XL, and subsequently triggering mitochondrial apoptotic pathway. In addition, pretreatment of cells with caspase‐9 inhibitor blocked ISL‐induced apoptosis, indicating that caspase‐9 activation is involved in ISL‐mediated HeLa cell apoptosis. These findings suggest that ISL may be a promising chemopreventive agent against human uterine cervical cancer.
The aliphatic isothiocyanates erucin and sulforaphane do not effectively up‐regulate NAD(P)H:quinone oxidoreductase (NQO1) in human liver compared with rat
Authors: Hanlon Natalya , Poynton Charlotte L. , Coldham Nick , Sauer Maurice J. , Ioannides Costas 
Published: July 2009

AbstractIsothiocyanate up‐regulation of hepatic NAD(P)H:quinone oxidoreductase (NQO1) and glutathione S‐transferases (GSTs) is an integral mechanism of their chemoprevention. In this paper, for the first time, the potential of the isothiocyanates erucin and sulforaphane to modulate these enzymes was investigated in two human livers and compared to rat liver. Precision‐cut liver slices were incubated with erucin or sulforaphane (1–50 μM). Both isothiocyanates elevated NQO1 activity in rat slices that was paralleled by a fourfold rise in protein levels. No change in activity was noted in human slices, and only a weak rise in protein levels, < 10% of that in rat, was observed in only one of the human livers, whereas the other was refractive. GST activity, assessed with three substrates, was elevated in rat slices treated with either isothiocyanate, and was accompanied by a rise in GSTα and GSTμ, but not GSTπ, protein levels. A rise in activity and in GSTα and GSTμ protein levels was also noted in one of the human livers. It appears that erucin and sulforaphane elevate GST expression in isoform‐specific manner in both rat and human liver, whereas NQO1 is inducible by these compounds only in rat liver and very poorly in human liver.
Production of hydrogen peroxide is responsible for the induction of apoptosis by hydroxytyrosol on HL60 cells
Authors: Fabiani Roberto , Fuccelli Raffaela , Pieravanti Federica , De Bartolomeo Angelo , Morozzi Guido 
Published: July 2009

AbstractHydroxytyrosol [3,4‐dihydroxyphenylethanol (3,4‐DHPEA)], a phenolic compound found exclusively in olive oil, exerts growth‐suppressive and pro‐apoptotic effects on different cancer cells. Although some molecular mechanisms involved in the pro‐apoptotic activity of 3,4‐DHPEA have been proposed, the initial stress signals responsible of this phenomenon are not known. Our aim was to assess the involvement of reactive oxygen species as mediators of apoptosis induced by 3,4‐DHPEA on HL60 cells. Apoptosis was determined by analyzing the nuclear fragmentation by both fluorescence microscopy and flow cytometry. The externalization of phosphatidylserine was evidenced using an Annexin V‐FITC kit. The concentration of H2O2 in the culture medium was measured by the ferrous ion oxidation‐xylenol orange method. The pro‐apoptotic effect of 3,4‐DHPEA (100 μM) was prevented by N‐acetyl‐cysteine, ascorbate, and α‐tocopherol. Catalase suppressed the 3,4‐DHPEA‐induced apoptosis, while the Fe(II)‐chelating reagent o‐phenantroline showed no effect, suggesting the involvement of H2O2 but not of OH•. Indeed, 3,4‐DHPEA caused accumulation of H2O2 in the culture medium. Tyrosol (p‐hydroxyphenylethanol) and caffeic acid, compounds structurally similar to 3,4‐DHPEA but not able to generate H2O2, did not induce an appreciable apoptotic effect. This is the first study demonstrating that apoptosis induction by 3,4‐DHPEA is mediated by the extracellular production of H2O2.
Production of Widely Different Dispersed Polymers in a Continuous Taylor–Couette Reactor
Authors: González Gemma , Colmenar Eduardo , Diaconu Gabriela , Alarcia Felipe , Manea Mihaela , Paulis María , Barandiaran Maria J. , Leiza José R. , de la Cal José C. , Asua José M. 
Published: July 2009

AbstractThe suitability of a continuous Taylor–Couette reactor to produce widely different dispersed polymers was investigated. It was found that it is possible to synthesize high solids acrylic pressure sensitive adhesives prepared by conventional emulsion polymerization, with higher conversion and narrower particle size distribution than the one produced with a CSTR. Coagulum free acrylic–alkyd and acrylic–clay hybrid latexes synthesized by miniemulsion polymerization, with final particle size similar to the initial droplet size, were also obtained. The suitability of this reactor to synthesize flocculants obtained by inverse microemulsion polymerization was also demonstrated.magnified image