bluuebunny/crossref_metadata_2025 huggingface dataset:
A multi‐access method for BPL based on orthogonal pulse division multiplexing, barker‐code‐based spectrum spreading and orthogonal frequency division multiplexing
Authors: Zhang Hong Xin , Lu Ying Hua , Nie Rong
Published: July 2009

A highly efficient multi‐access scheme of broadband power line (BPL) communication, named as OFDM‐BPS‐OPDMA, is proposed based on the Orthogonal Pulse Division Multiplexing Access (OPDMA), Barker‐code‐based Spectrum Spreading (BSS) and Orthogonal Frequency Division Multiplexing (OFDM) method. The orthogonal pulses are generated by using the eigenvectors of Hermitian matrix. At the same time, a specific pulse will be allocated to every user of the communication system. The transmitting data are first modulated by OFDM. Then, it is processed with OPDMA and BSS. Finally, the data is sent to the power line channel. On the receiving side, the data is processed with BSS demodulation, OPDMA demodulation and OFDM demodulation, and the receiving data for each user is acquired. Because of the orthogonality between these pulses, the multi‐user interference could be eliminated; when BSS is used, the waveform restoration is enhanced. Meanwhile, with the help of OFDM, the multi‐path interference is mitigated. Particularly, all users can share the resources of time and spectrum without interfering with others, and get excellent reliability in the concerned scheme. When OFDM is used, the sub‐carriers may be allocated dynamically, and the legal radio frequency band could be shunned by sharing the common bandwidth with other communication systems. Copyright © 2009 John Wiley & Sons, Ltd.
Stress‐induced laboratory eating behavior in obese women with binge eating disorder
Authors: Laessle Reinhold G. , Schulz Simone
Published: July 2009

Objective:

To compare the microstructural eating behavior of obese patients with and without binge eating disorder (BED) after stress induction in laboratory.

Method:

Forty‐eight obese women were investigated. Seventeen were assigned to the group of BED. Group (BED vs. non‐BED) by condition (stress vs. no stress) interaction effect on feeding variables, measured by a universal eating monitor, was tested. Stress was induced by the trier social stress test (TSST) and chocolate pudding served as laboratory food.

Results:

From the nonstress to the stress condition, patients with BED, when compared with non‐BED had a greater increase in average eating rate (p < .01) and a corresponding greater increase in the frequency of spoonfuls (p < .02). The BED group also showed a different change in acceleration/deceleration from the nonstress to the stress condition compared to the non‐BED group (p < .04).

Discussion:

Obese individuals with BED appear to exhibit a different response to stress than obese non‐BED individuals and individuals with bulimia nervosa. © 2009 by Wiley Periodicals, Inc. Int J Eat Disord 2009
Bis(terdentate) Pyrazole/Pyridine Ligands: Synthesis, Crystal Structures and Magnetic Properties of Bridged Binuclear and Tetranuclear Copper(II) Complexes
Authors: Kumar Singh Akhilesh , van der Vlugt Jarl Ivar , Demeshko Serhiy , Dechert Sebastian , Meyer Franc
Published: July 2009

A new binucleating bis(terdentate) ligand, 3,5‐[3‐bis(2‐pyridyl)pyrazole‐1‐ylmethyl]pyrazole (HL2), was synthesized. Reaction of the deprotonated ligand L2 with hydrated CuII salts gives (μ‐pyrazolato)(μ‐hydroxido)‐bridged binuclear and tetranuclear complexes [L2Cu2(μ‐OH)(ClO4)(MeCN)](ClO4) (2), [L2Cu2(dmf)2(μ3‐OH)]2(ClO4)4·4dmf (3·4dmf) and [L2L′Cu2](ClO4)2 [4; HL′ = 3‐(2‐pyridyl)pyrazole]. In these complexes, both μ‐OH and μ3‐OH bridges were observed. This contrasts the situation for a dicopper(II) complex of the related bis(terdentate) ligand 3,5‐bis[6(2,2′‐dipyridyl)]pyrazole (HL1), {L1Cu2(OMe)(MeOH)[κ1‐O‐(NO3)]}{[Cu2(NO3)2(μ‐OMe)2]}0.5·MeOH (1·MeOH), where the shorter and more rigid ligand side arms enforce a larger Cu···Cu separation and the formation of a MeO–HOMe moiety within the bimetallic pocket. Molecular structures of all complexes were elucidated by X‐ray crystallography. Variable‐temperature magnetic susceptibility measurements (295–2 K) for powdered samples of complexes 2–4 reveal strong antiferromagnetic coupling between two copper centres. The magnitude of the coupling is discussed in view of the structural features. During the preparation of complex 4, partial ligand hydrolysis was also observed, but this strongly depends on the reaction conditions.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Role of Coordinated Water and Hydrogen‐Bonding Interactions in Stabilizing Monophenoxido‐Bridged Triangular CuIIMII­CuII Compounds (M = Cu, Co, Ni, or Fe) Derived from N,N′‐Ethylenebis(3‐meth­oxysalicylaldimine): Syntheses, Structures, and Magnetic Properties
Authors: Majumder Samit , Koner Rajesh , Lemoine Pascale , Nayak Malabika , Ghosh Meenakshi , Hazra Susanta , Lucas C. Robert , Mohanta Sasankasekhar
Published: July 2009

The syntheses, structures, and magnetic properties of the trinuclear triangular compounds [{CuIIL1}2CuII(H2O)2](ClO4)2·H2O (1) and [{CuIIL1}2MII(H2O)2](ClO4)2 {M = Ni (2), Co (3), Fe (4)} derived from N,N′‐ethylenebis(3‐methoxysalicylaldimine) (H2L1) are described. Compound 1 crystallizes in the monoclinic P21/n space group, while the crystal system for the isomorphous compounds 2–4 is monoclinic P21/c. In the cations of these compounds, two copper(II) ions occupy the salen type N2O2 cavity of two [L1]2– ligands, while one phenoxido and one methoxy oxygen atom of each of these two [CuIIL1] moieties coordinate to a central metal ion, which results in the formation of the trinuclear CuII2MII systems in which the two pairs of central···terminal metal ions are monophenoxido‐bridged. In addition, to the two phenoxido bridges, the central metal ion is coordinated to two methoxy and two water oxygen atoms. The coordinated water molecules are strongly hydrogen bonded to the phenoxido and methoxy oxygen atoms. The presence of the coordinated water molecules and the interaction of these water molecules with the phenoxido and methoxy oxygen atoms are proposed to be the governing factors for the stabilization of the rare example of the monophenoxido‐bridged CuII3 compound 1 and of the first examples of the monophenoxido‐bridged CuII2MII compounds 2–4. The three metal ions define an isosceles triangle. The phenoxido bridge angles in these compounds are significantly obtuse and vary between 121.10(12)° and 129.84(13)°. On the other hand, the trinuclear cores are highly twisted as evidenced from the range of the dihedral angles (58.5–143.7°) between the basal planes of the terminal and the central metal ions. The variable‐temperature (2–300 K) magnetic susceptibilities of compounds 1–4 have been measured. The magnetic data for 1 have been analyzed by using a model of two exchange integrals for the two pairs of adjacent metal ions, while one J value is considered for the other three complexes. The exchange integrals obtained are: CuII3 compound 1: J1 = –97.6 cm–1, J2 = –89.5 cm–1; CuII2NiII compound 2: J = –25.4 cm–1; CuII2CoII compound 3: J = –9.0 cm–1; CuII2FeII compound 4: J = –6.5 cm–1. These moderate to weak antiferromagnetic interactions in 1–4 are related to the twisting of the trinuclear cores. The relative order of the exchange integrals can been understood from the nature of the magnetic orbitals. The structural and magnetic results have been compared with previously reported related compounds.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Syntheses, Structures and Magnetic Properties of Heterobridged Dinuclear and Cubane‐Type Tetranuclear Complexes of Nickel(II) Derived from a Schiff Base Ligand
Authors: Hazra Susanta , Koner Rajesh , Lemoine Pascale , Sañudo E. Carolina , Mohanta Sasankasekhar
Published: July 2009

Syntheses, structures and magnetic properties of a heterobridged μ‐phenoxido‐μ1,1‐NCO dinickel(II) compound [NiII2(HL)3(μ‐NCO)]·2H2O (1) and a heterobridged bis(μ3‐phenoxido)bis(μ3‐alkoxido)tetranickel(II) system, [NiII4(L)2(HL)2(SeCN)2(H2O)2]·C3H7NO·4H2O (2), containing a cubane‐type NiII4O4 core, derived from the tetradentate Schiff base compartmental ligand N‐(2‐hydroxyethyl)‐3‐methoxysalicylaldimine (H2L) were described. Compounds 1 and 2 crystallize in triclinic P$\bar {1}$ and monoclinic P21/c systems, respectively. Compound 2, in which the Ni4O4 cubane core is composed of two μ3‐phenoxido and two μ3‐alkoxido moieties, represents the sole example of this type. The variable‐temperature (2–300 K) magnetic susceptibilities and magnetizations of these two compounds were measured. The interaction between the metal centres in dinuclear compound 1 is weak ferromagnetic, resulting in an ST = 2 ground state at 2 K. The overall interaction observed in 2 is weak ferromagnetic, leading to an unusual ST = 3 ground state. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Scale‐up of Oldenlandia affinis suspension cultures in photobioreactors for cyclotide production
Authors: Seydel Peter , Walter Christian , Dörnenburg Heike
Published: July 2009

Cyclotides are a family of backbone‐cyclized cystine‐knot‐containing macrocyclic peptides from plants that possess extremely interesting biological activities. Suspension cultures of Oldenlandia affinis, a model plant containing cyclotides, were scaled‐up from shake flask to photobioreactor operation in order to produce these plant peptides under controlled conditions. Cell growth was highly dependent on inoculation culture; cell density as well as culture age had an effect on the growth rates and thus affected the kalata B1 productivity of the bioprocess.

In a 25 l scale bioreactor the maximum doubling time was about 1.12 days compared to 2.24 days in shake flasks. The accumulation of kalata B1 of 0.09 mg g−1 DW and 0.07–0.10 mg g−1 DW respectively, however, was on a similar level during the corresponding stationary growth phases in both bioreactor and flask processes.

An adjustment of cell culture growth via culture preparation and inoculum density to high cyclotide accumulation results in an estimated output during the most productive retardation phase of about 21 mg kalata B1 per day in the 25 l system. This makes the biotechnological cyclotide synthesis under GMP conditions a competitive production tool compared to field cultivation, chemical, and recombinant synthesis in drug discovery for structure analysis and bioactivity assays.
Photobioreactor for cultivation and real‐time, in‐situ measurement of O2 and CO2 exchange rates, growth dynamics, and of chlorophyll fluorescence emission of photoautotrophic microorganisms
Authors: Červený Jan , Šetlík Ivan , Trtílek Martin , Nedbal Ladislav
Published: July 2009

A detailed knowledge about the dynamics of phytoplanktonic photosynthesis and respiration is crucial for the determination of primary productivity in open oceans as well as for biotechnological applications. The dynamics are best studied in photobioreactors that are able to simulate natural conditions in such, that light can be modulated not only diurnally but also mimicking effects of solar elevation angle from sunrise to sunset, variable cloudiness, light modulation in refractory sun flecks due to water waves, or light intermittence due to turbulent flow in dense suspensions. In addition, high performance photobioreactors ought to be able to monitor in real time photosynthetic and respiratory activities as well as culture growth. Here, we demonstrate performance of a newly designed bench‐top laboratory photobioreactor that meets these needs, with a study of green alga Scenedesmus quadricauda. The algal suspension was exposed to simulated daily variations of total photosynthetic active irradiance and spectral profile, with a larger proportion of red photons in the morning and evening hours. The instrument monitored automatically the culture growth by measuring the optical densities at 735 nm and 680 nm and by measuring steady state and maximal chlorophyll fluorescence emission yields. The photochemical yields were estimated from chlorophyll fluorescence data. These widely used but rather indirect yield estimates were confronted with direct measurements of oxygen evolution and consumption quantum yields. The CO2 fluxes in and out of the culture media as well as the dissolved CO2 in algal suspension were also recorded. The experiments demonstrated potential of the new photobioreactor to reveal minute modulations in gas exchange rates as well as to yield data for calculation of photon requirement of oxygen evolution in the suspension volume that is key technological parameter for planning of large scale photobioreactors as well as key optimization parameter for strain selection.
Damping analysis of primary and auxiliary control of HVDC systems
Authors: Yu Tao , Tong Jia‐peng , Chan Ka Wing
Published: July 2009

It is well documented that an inappropriate HVDC controller will cause dynamic instability in an AC/DC system. In order to have a better analysis on the mechanism of this phenomenon, this paper proposes a generic theoretical equation of electric damping coefficient of a HVDC link using the complex torque coefficient (CTC) method for quantitatively analysis of the damping characteristics of different types of HVDC control systems. Furthermore, a theoretical design methodology will also be established to improve the performances of the HVDC primary and auxiliary control systems with an application example. Copyright © 2009 John Wiley & Sons, Ltd.
Evaluation of clinical biomaterial surface effects on T lymphocyte activation
Authors: Rodriguez Analiz , Anderson James M.
Published: July 2009

Previous in vitro studies in our laboratory have shown that lymphocytes can influence macrophage adhesion and fusion on biomaterial surfaces. However, few studies have evaluated how material adherent macrophages can influence lymphocyte behavior, specifically T cells. In this study, we cultured human peripheral blood mononuclear cells from healthy donors on three synthetic nonbiodegradable biomedical polymers: elasthane 80A (PEU), silicone rubber (SR), or polyethylene terephthalate (PET) and tissue culture polystyrene (TCPS). Upregulation of T cell surface activation markers (CD69 and CD25), lymphocyte proliferation, and interleukin‐2 (IL‐2) and interferon‐γ (IFNγ) concentrations were evaluated by flow cytometry, carboxy‐fluorescein diacetate, succinimydyl ester (CFSE) incorporation, and multiplex cytokine immunoassay, respectively, to assess T cell activation. Following 3 and 7 days of culture, CD4+ helper T cells from cultures of any of the material groups did not express the activation markers CD69 and CD25 and lymphocyte proliferation was not present. IL‐2 and IFNγ levels were produced, but dependent on donor. These data indicate that T cells are not activated in response to clinically relevant synthetic biomaterials. The data also suggest that lymphocyte subsets exclusive of T cells are the source of the lymphokines, IL‐2 and IFN‐γ, in certain donors. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res, 2010
Response of rat osteoblasts to polycaprolactone/chitosan blend porous scaffolds
Authors: Wu Hua , Wan Ying , Dalai Siqin , Zhang Rui
Published: July 2009

Novel porous polycaprolactone/chitosan blend scaffolds were fabricated via a particle‐leaching technique using hexafluoro‐2‐propanol as a shared solvent and salt particles as porogen. By selecting optimized processing conditions, numerous blend scaffolds were already built with well‐controlled porous structures and approximately similar pore parameters. The interactions between these scaffolds and the rat osteoblasts were further investigated by measuring the adhesion, proliferation, and morphologies of cells as well as the corresponding alkaline phosphatase activity during various culture periods in vitro. Data collected from different measurements reflected that by incorporating an appropriate amount of chitosan component, the resultant blend scaffolds could improve the adhesion and growth of osteoblasts and exert a significant impact on the osteoblastic phenotype. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res, 2010
[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

The 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

Recognition 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

Brain 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

A 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

In 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

On‐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

A 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

The 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

Surface‐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.

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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

The 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.

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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

The 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.

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Quantification of climate for tourism in the northwest of Iran
Authors: Farajzadeh Hassan , Matzarakis Andreas
Published: July 2009

Tourism 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

This 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

Isothiocyanate 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

Hydroxytyrosol [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

The 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.

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Repression of MAL tumour suppressor activity by promoter methylation during cervical carcinogenesis
Authors: Overmeer Renée M , Henken Florianne E , Bierkens Mariska , Wilting Saskia M , Timmerman Ilse , Meijer Chris JLM , Snijders Peter JF , Steenbergen Renske DM
Published: July 2009

We recently identified MAL (T‐lymphocyte maturation associated protein) as the most down‐regulated gene in cervical oncogenesis. Here, we examined the mechanism underlying MAL silencing, its functional role in cervical carcinogenesis, and the relevance of detecting MAL alterations for risk assessment of hrHPV‐positive women. MAL mRNA expression and promoter methylation were analysed in primary keratinocytes, hrHPV‐immortalized keratinocytes, cervical cancer cell lines, biopsies, and scrapings by quantitative (methylation‐specific) PCR. SiHa cells were transfected with MAL cDNA and assayed for proliferation, migration, and anchorage‐independent growth. MAL mRNA was (nearly) undetectable in all HPV‐immortalized and cervical cancer cells, but could be up‐regulated upon methylation inhibition. MAL promoter methylation at two promoter regions (M1 and M2) was detected in all HPV‐immortalized cells and cancer cells. Ectopic expression of MAL in SiHa cells suppressed proliferation, migration, and anchorage‐independent growth. None (0/22) of normal cervical biopsies, 9% (6/66) of CIN1 lesions, 53% (34/64) of CIN3 lesions, 90% (85/94) of cervical squamous cell carcinomas (SCCs), and 93% (26/28) of cervical adenocarcinomas (AdCAs) demonstrated MAL promoter methylation at both promoter regions. Moreover, detection of MAL promoter methylation in cervical scrapings was predictive for underlying high‐grade lesions. Both in biopsies and in scrapings, MAL promoter methylation was significantly correlated with reduced mRNA expression. MAL gene silencing by promoter methylation is a frequent and biologically essential event in HPV‐induced cervical carcinogenesis. Hence, MAL promoter methylation and/or mRNA expression analysis on cervical scrapings may provide a valuable diagnostic tool to improve the detection of CIN3, SCC, and AdCA. Copyright © 2009 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Conditional deletion of the Lkb1 gene in the mouse mammary gland induces tumour formation
Authors: McCarthy Afshan , Lord Christopher J , Savage Kay , Grigoriadis Anita , Smith Darrin P , Weigelt Britta , Reis‐Filho Jorge S , Ashworth Alan
Published: July 2009

Heterozygous germline mutations in the LKB1 (STK11) gene cause Peutz‐Jeghers syndrome (PJS), an autosomal dominant disorder characterized by hamartomatous polyposis of the gastrointestinal tract and an increased risk of colorectal, breast, and other cancers. To model the role of LKB1 mutation in mammary tumourigenesis, we have used a conditional gene targeting strategy to generate a mouse in which exons encoding the kinase domain of Lkb1 were deleted specifically in the mammary gland. Mammary gland tumours developed in these mice with a latency of 46–85 weeks and occurred in the thoracic or inguinal glands. These tumours were grade 2 invasive ductal carcinomas or solid papillary carcinomas with histological features similar to those described in breast cancers arising in patients with PJS. This mouse model of Lkb1 deficiency provides a potentially useful tool to investigate the role of Lkb1 in tumourigenesis and to guide the development of therapeutic approaches. Copyright © 2009 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
The transcriptional regulatory function of p53 is essential for suppression of mouse skin carcinogenesis and can be dissociated from effects on TGF‐β‐mediated growth regulation
Authors: Ponnamperuma Roshini M , King Kathryn E , Elsir Tamador , Glick Adam B , Wahl Geoffrey M , Nister Monica , Weinberg Wendy C
Published: July 2009

Transcriptional regulation by p53 is critical for p53‐mediated tumour suppression; however, p53‐mediated transactivation has been dissociated from p53‐mediated biological processes including apoptosis, DNA repair, and differentiation. We compared the effects of a mutant allele, p53QS − val135, containing a double mutation in the amino‐terminus abrogating transactivation activity and a modification at amino acid 135 partially affecting DNA binding, to complete loss of p53. We applied in vitro endpoints correlated with epithelial tumourigenesis and an in vivo assay of tumour phenotype to assess whether loss of p53‐mediated transcriptional regulation underlies the malignant phenotype of p53−/−/v‐rasHa‐overexpressing keratinocytes. Transactivation deficiency of p53QS‐val135 was confirmed by reporter gene assays in fibroblasts and differentiating keratinocytes. Ras oncogene‐induced senescence was lost in both p53QS − val135/QS − val135 and p53−/− keratinocytes. Similarly, p53QS − val135/QS − val135, like p53−/−, cooperated with v‐rasHa to enhance malignant conversion. The tumours arising in p53QS − val135/QS − val135 keratinocytes displayed strong nuclear p53 expression; thus, the p53QS − val135 allele was maintained and the deficient transactivation function of the expressed p53QS mutant protein was supported by absence of p21waf1 in these tumours. The p53QS − val135 allele did not confer a dominant‐negative phenotype, as p53+/QS − val135 keratinocytes senesced normally in response to v‐rasHa expression and formed benign tumours. While p53−/− keratinocytes displayed diminished response to TGF‐β, p53QS − val135/QS − val135 and p53+/+ keratinocytes responded equivalently, indicating that the requirement for p53 in maximizing TGF‐β‐mediated growth regulation is independent of its transactivation domain and that the ability of keratinocytes to respond to TGF‐β is insufficient to suppress the malignant phenotype in this model. Furthermore, TGF‐β enhances p53QS‐induced activation of a dual p53‐TGF‐β responsive reporter in a keratinocyte cell line. These findings support an essential role for p53‐mediated transcriptional regulation in suppressing malignancies arising from ras‐induced skin tumours, consistent with previous findings in spontaneous carcinogenesis in other organs, and highlight the potential importance of senescence for tumour suppression in vivo. Copyright © 2009 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.