bluuebunny/crossref_metadata_2025 huggingface dataset:
Novel synthetic route for 5‐substituted 6‐arylmethylluracils from 2,4,6‐trichloropyrimidines
Authors: Loksha Yasser M.
Published: November 2009

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Treatment of 2,4,6‐trichloropyrimidines (1a,1b) with the sodium salt of benzyl cyanide derivatives (2a,2b) afforded 5‐substituted 4‐aryl(cyanomethyl)‐2,6‐dichloropyrimidines (3a,3b,3c,3d,3e,3f). Compounds3a,3bwere alkylated with methyl iodide to furnish 4‐(1‐aryl‐1‐cyanoethyl)‐2,6‐dichloropyrimidines (4a,4b). Compounds3a,3b,3c,3d,3e,3fand4a,4bwere hydrolyzed with concentrated hydrochloric acid to afford 5‐substituted 6‐arylalkyluracils5a,5b,5c,5d,5e,5f,5g,5h. 5‐Bromo‐6‐arymethylluracils (6a,6b,6c,6d) were synthesized by bromination of 6‐arylmethylluracils (5a,5b,5c,5d) withN‐bromosuccinimide (NBS). Refluxing 2‐(2,6‐dichloro‐5‐ethylpyrimidin‐4‐yl)‐2‐(3,5‐dimethylphenyl)acetonitrile (3f) with sodium methoxide followed by oxidation afforded (3,5‐dimethylphenyl)(5‐ethyl‐2,6‐dimethoxypyrimidin‐4‐yl)methanone (7). Addition of methylmagnesium bromide to compound7gave the tertiary alcohol derivative8which was fluorinated by diethylaminosulfurtrifluoride and deprotected by trimethylsilyl iodide to furnish 6‐(1‐(3,5‐dimethylphenyl)‐1‐fluoroethyl)‐5‐ethylpyrimidine‐2,4(1H,3H)‐dione (12). J. Heterocyclic Chem., (2009).
Distributive impacts of the food price crisis in the Andean region
Authors: Cuesta José , Duryea Suzanne , Jaramillo Fidel , Robles Marcos
Published: November 2009

This study analyses the distributive consequences associated with the recent international food price crisis in the Andean region. The study explores the distributive repercussions of the crisis by means of a simple simulation exercise which isolates the direct and short‐term effects of actual increases in food prices across the Andean region. The paper finds substantive and heterogeneous poverty impacts, ranging from two to six per cent points in the incidence of poverty. Results are found very sensitive to the net consumer (or producer) position of the household, and less so across other characteristics of the household. Copyright © 2009 John Wiley & Sons, Ltd.
Introduction to the special issue on Bayesian journey‐to‐crime modelling
Authors: Levine Ned
Published: November 2009

In this special issue of the Journal of Investigative Psychology and Offender Profiling, we explore a Bayesian approach to journey‐to‐crime (JTC) estimation with an emphasis on the statistical models used. The approach conceptualises the probability that an offender lives at one location as the product of the probability distribution from a JTC estimate along with the probability distribution of other offenders who committed crimes in the same locations. The Bayesian approach is appropriate as the second part is conditional on the first part. The introduction gives the background behind the methodology and suggests how future improvements can be made by integrating new information. Finally, the papers in the special issue are introduced. Copyright © 2009 John Wiley & Sons, Ltd.
Protective effects of enzymatic digest fromEcklonia cavaagainst high glucose‐induced oxidative stress in human umbilical vein endothelial cells
Authors: Lee Seung‐Hong , Heo Soo‐Jin , Hwang Ji‐Young , Han Ji‐Sook , Jeon You‐Jin
Published: November 2009

BACKGROUND:Antioxidants can prevent pathological damage caused by hyperglycaemia‐induced oxidative stress associated with diabetes. In the present study, we investigated whether the brown algaEcklonia cavahas protective effects against high glucose‐induced oxidative stress in Human umbilical vein endothelial cells (HUVECs). For that purpose, we prepared an enzymatic digest fromE. cava(ECC) by using the carbohydrase, Celluclast.

RESULTS:High glucose treatment induced HUVECs cell death, but ECC, at a concentration of 10 or 100 µg mL−1, significantly inhibited the high glucose‐induced cytotoxicity. Furthermore, treatment with ECC dose‐dependently decreased thiobarbituric acid reactive substances (TBARS), intracellular generation of reactive oxygen species, and the nitric oxide level increased by high glucose. In addition, ECC treatment increased activities of antioxidant enzymes including catalase, superoxide dismutase and glutathione peroxidase in high‐glucose pretreated HUVECs. High glucose levels induced the overexpression of inducible nitric oxide synthase, cyclooxygenase‐2 and nuclear factor‐kappa B proteins in HUVECs, but ECC treatment reduced the overexpression of these proteins.

CONCLUSION:These results suggest that ECC is a potential therapeutic agent that will reduce the damage caused by hyperglycaemia‐induced oxidative stress associated with diabetes. Copyright © 2009 Society of Chemical Industry
Diabetes‐related changes in auditory brainstem responses
Authors: Konrad‐Martin Dawn , Austin Donald F. , Griest Susan , McMillan Garnett P. , McDermott Daniel , Fausti Stephen
Published: November 2009

Objectives/Hypothesis:

Determine effects on auditory brainstem response (ABR) of diabetes mellitus (DM) severity.

Study Design:

A cross‐sectional study investigating DM severity and ABR in military Veteran subjects with (166) and without (138) DM and with no more than moderate hearing loss.

Methods:

Subjects were classified by three age tertiles (<50, 50–56, and 57+). DM severity was classified as insulin‐dependent (IDDM), non–insulin‐dependent (NIDDM), or no DM. Other DM measures included serum glucose, HbA1c, and several DM‐related complications. ABR measures included wave I, III, and V latencies; I–III, III–V, and I–V latency intervals; and wave V amplitude; for each ear at three repetition rates (11, 51, and 71 clicks/second), and both polarities. Outcomes were stratified by age tertile and adjusted for pure tone threshold at 3 kHz. Repeated measures multivariate analysis of covariance modeled the ABR response at each repetition rate for DM severity (main effect) and hearing at 3 kHz (covariate). Modeled contrasts between ABR variables in subjects with and without DM were examined.

Results:

Significant differences existed between no DM and IDDM groups in the younger tertile only. Adjusting for threshold at 3 kHz had minimal effect. Self‐reported noise exposure was not related to ABR differences, but HbA1c and poor circulation were.

Conclusions:

IDDM is associated with an increased wave V latency, wave I–V interval, and reduced wave V amplitude among Veterans under 50 years. Results were related to several DM complications. Laryngoscope, 2010
Amphiphilic Block Copolymers Bearing Ortho Ester Side‐Chains: pH‐Dependent Hydrolysis and Self‐Assembly in Water
Authors: Tang Rupei , Ji Weihang , Wang Chun
Published: November 2009

A new type of pH‐responsive block copolymer nanoparticle has been synthesized and characterized. The amphiphilic diblock copolymer, PEG‐b‐PMYM, contains acid‐labile ortho ester side‐chains in the hydrophobic block and can self‐assemble into micelle‐like nanoparticles in water at neutral pH. Hydrolysis of the ortho ester side‐chains follows a distinct exocyclic mechanism and shows pH‐dependent kinetics, which triggers changes in nanoparticle size and morphology. The nanoparticles have been found to be non‐toxic to cells in vitro. The ability to tune the size and morphology of biocompatible block copolymer nanoparticles by controlling the pH‐sensitive side‐chain hydrolysis represents a unique approach that may be exploited to improve the efficacy of nanometer‐scale drug delivery.

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High‐temperature oxidation behaviour of model CoReCr alloys at low oxygen partial pressure
Authors: Gorr B. , Burk S. , Trindade V. B. , Christ H.‐J.
Published: November 2009

The oxidation behaviour of four model CoReCr alloys and a commercial Co‐based alloy was investigated at 1000 °C and a low‐oxygen partial pressure of p(O2) = 10−16 bar, in order to prove the feasibility of a pre‐oxidation treatment. Under suitable conditions of the pre‐oxidation treatment, the oxidation of the highly reactive alloying element Cr is possible. All the studied alloys form a continuous and dense Cr2O3 scale on the metal surface. The transport of chromium to the surface occurs mainly from the Cr‐rich σ‐phase, which becomes completely dissolved in the surrounding matrix after long exposure times. As a result of the Cr2O3 scale, growth depletion of Cr occurs in the near surface region, leading to internal oxidation.
Effect of grain refinement on corrosion of ferritic–martensitic steels in supercritical water environment
Authors: Ren X. , Sridharan K. , Allen T. R.
Published: November 2009

The effects of grain refinement on the corrosion behavior of three ferritic–martensitic (F/M) steels, HT9, T91, and NF616, and two binary model alloys Fe‐15%Cr and Fe‐18%Cr in supercritical water (SCW) have been investigated. Grain refinement down to a size of about one micron in the surface regions, was achieved by introducing severe plastic deformation by shot peening. After exposure to SCW with 25 ppb oxygen at 500 °C for up to 3000 h, an improvement in corrosion resistance was observed in grain‐refined samples because of the enhanced diffusion of chromium on the surface, through a high density of grain boundaries. The chromium content in the steels and the exposure durations in SCW were determined to be important factors influencing the efficacy of the grain refinement effects. These results are supported by both experimental evidence and theoretical predictions. Another approach for grain refinement, equal channel angular pressing (ECAP), was also investigated for T91 steel. ECAP resulted in lower weight gain due to corrosion compared to the untreated samples, but exhibited a slightly higher weight gain compared to the shot‐peened samples after long‐term exposures in SCW which is probably caused by different fractions of high‐angle grain boundaries in grain‐refined regions, introduced by different grain refinement techniques.
Effect of ethanol as gasoline additive on vehicle fuel delivery system corrosion
Authors: Jafari H. , Idris M. H. , Ourdjini A. , Rahimi H. , Ghobadian B.
Published: November 2009

In this research, the effect of ethanol as gasoline additive has been investigated into metal corrosion of a fuel delivery system. Corrosion tests have been performed in gasoline with different percentages of ethanol, using weight loss (immersion test) and electrochemical impedance stereoscopy (EIS) procedures. Surface of test specimens were checked by scanning electron microscopy (SEM) after 144 days of immersion in test solution. Also corroded components were analyzed using energy‐dispersive X‐ray analysis (EDAX) method. Test results, investigations, and analyses, altogether show more corrosion with the increase in ethanol percentage and water content in gasoline. Test results show that among different materials in fuel delivery system, aluminum alloys and hard soldering alloys have less corrosion than the others. Also chloride and sulfide were recognized as the main compound of corrosion products; therefore, the control of these two elements in fuel delivery system is a must in case of using ethanol as fuel additive in near future.
Dietary flaxseed lignan or oil combined with tamoxifen treatment affects MCF‐7 tumor growth through estrogen receptor‐ and growth factor‐signaling pathways
Authors: Saggar Jasdeep Kaur , Chen Jianmin , Corey Paul , Thompson Lilian U.
Published: November 2009

This study aimed to elucidate which component of flaxseed,i.e.secoisolariciresinol diglucoside (SDG) lignan or flaxseed oil (FO), makes tamoxifen (TAM) more effective in reducing growth of established estrogen receptor positive breast tumors (MCF‐7) at low circulating estrogen levels, and potential mechanisms of action. In a 2×2 factorial design, ovariectomized athymic mice with established tumors were treated for 8 wk with TAM together with basal diet (control), or basal diet supplemented with SDG (1 g/kg diet), FO (38.5 g/kg diet), or combined SDG and FO. SDG and FO were at levels in 10% flaxseed diet. Palpable tumors were monitored and after animal sacrifice, analyzed for cell proliferation, apoptosis, ER‐mediated (ER‐α, ER‐β, trefoil factor 1, cyclin D1, progesterone receptor, AIBI), growth factor‐mediated (epidermal growth factor receptor, human epidermal growth factor receptor‐2, insulin‐like growth factor receptor‐1, phosphorylated mitogen activated protein kinase, PAKT, BCL2) signaling pathways and angiogenesis (vascular endothelial growth factor). All treatments reduced the growth of TAM‐treated tumors by reducing cell proliferation, expression of genes, and proteins involved in the ER‐ and growth factor‐mediated signaling pathways with FO having the greatest effect in increasing apoptosis compared with TAM treatment alone. SDG and FO reduced the growth of TAM‐treated tumors but FO was more effective. The mechanisms involve both the ER‐ and growth factor‐signaling pathways.
Garlic components inhibit angiotensin II‐induced cell‐cycle progression and migration: Involvement of cell‐cycle inhibitor p27Kip1and mitogen‐activated protein kinase
Authors: Castro Claudia , Lorenzo Andrea Gil , González Adriana , Cruzado Montserrat
Published: November 2009

Garlic has been used for prevention and treatment of hypertension; however, the molecular mechanisms of garlic's effects remain to be elucidated. In this study, the mechanisms of thein vitroeffect of organosulphur compounds derived from garlic on growth and migration of cultured aortic smooth muscle cells isolated from spontaneously hypertensive rats were investigated. We demonstrated that allyl methyl sulphide (AMS) and diallyl sulphide (DAS) inhibited aortic smooth muscle cell angiotensin II‐stimulated cell‐cycle progression and migration. Neither cell viability nor annexin‐V‐binding analysis revealed cytotoxic effects of both organosulphur compounds at the used concentrations. Instead, their inhibitory effects were associated to the prevention of the cell‐cycle inhibitor p27Kip1(p27) downregulation and the reduction of extracellular signal‐regulated kinase 1/2 phosphorylation. When we assessed the antioxidant activity of AMS and DAS, we found that both organosulphur compounds inhibited angiotensin II‐reactive oxygen species generation. Our findings show that AMS and DAS, compounds derivate from garlic, could be effective antioxidants targeted at the arterial remodelling seen in hypertension.
Effect of sulforaphane on glutathione‐adduct formation and on glutathione_S_transferase‐dependent detoxification of acrylamide in Caco‐2 cells
Authors: Pernice Rita , Hauder Johanna , Koehler Peter , Vitaglione Paola , Fogliano Vincenzo , Somoza Veronika
Published: November 2009

The toxicity of dietary acrylamide (AA) depends on its biotransformation pathways, in which phase I cytochrome P‐450 enzymes transform AA into glycidamide. The phase II enzyme glutathione_S_transferase (GST) catalyses the conjugation of AA with glutathione (GSH). GST induction by phytochemicals like sulforaphane (SFN) plays a role in chemoprevention. Here, the effect of SFN on the detoxification of AA through GSH conjugation was studied in Caco‐2 cells. GSH adducts with AA and SFN were synthesized, identified by NMR and quantified by LC‐MS/MS. Caco‐2 cells were treated with either 2.5 mM AA, 10 μM SFN or the combination of both for 24 h. Concentrations of GSH conjugates (GSH‐AA, GSH‐SFN, SFN‐GSH‐AA), AA and SFN were analysed by LC‐MS/MS. GSH contents and GST activity were determined photometrically. GST activity was increased after treatment of the cells with SFN (38±6%, p≤0.05) or AA (25±4%, p≤0.05). GSH concentrations decreased after all treatments. Quantitative data of GSH adduct formation showed that the reaction between GSH and SFN is favoured over that between GSH and AA. The data suggest that SFN might impair the GSH‐dependent detoxification of AA by SFN‐GSH adduct formation and, thus, lower the GSH concentrations available for its reaction with AA.
Histological validation of ultrasound‐guided neurography in early nerve regeneration
Authors: van Neck Johan W. , de Kool B. Stefan , Hekking‐Weijma J. (Ineke) M. , Walbeehm Erik T. , Visser Gerhard H. , Blok Joleen H.
Published: November 2009

Ultrasound‐guided near‐nerve neurography is a new tool that can be used to assess nerve regeneration before reinnervation occurs. In this study, ultrasound‐guided near‐nerve measurements were validated against axon diameter counts in rabbits during a 15‐week regeneration period after a crush lesion of their peroneal nerve. The course of the nerve was determined ultrasonically, and the active near‐nerve needle electrode was maneuvered just next to the nerve under ultrasound guidance. Measured action potentials were compared with axon diameter counts from histological sections of these same nerves. A moderate to good positive correlation was found, which reached a maximum of 0.7 at a cut‐off of 3 μm, corresponding to the minimal size of the myelinated axons. Our results suggest that, following a similar validation study in humans, ultrasound‐guided near‐nerve neurography may be clinically useful when early evaluation of nerve activity is needed. Muscle Nerve, 2009
Adaptive change in electrically stimulated muscle: A framework for the design of clinical protocols
Authors: Salmons Stanley
Published: November 2009

Adult mammalian skeletal muscles have a remarkable capacity for adapting to increased use. Although this behavior is familiar from the changes brought about by endurance exercise, it is seen to a much greater extent in the response to long‐term neuromuscular stimulation. The associated phenomena include a markedly increased resistance to fatigue, and this is the key to several clinical applications. However, a more rational basis is needed for designing regimes of stimulation that are conducive to an optimal outcome. In this review I examine relevant factors, such as the amount, frequency, and duty cycle of stimulation, the influence of force generation, and the animal model. From these considerations a framework emerges for the design of protocols that yield an overall functional profile appropriate to the application. Three contrasting examples illustrate the issues that need to be addressed clinically. Muscle Nerve, 2009
Auf dem Weg zum 1‐Liter‐ICP
Authors: Engelhard Carsten , Buscher Wolfgang
Published: November 2009

Eine neue Anregungseinheit für die ICP‐OES senkt den Gesamtverbrauch des Betriebsgases Argon um 95 Prozent.
Für mehr Sicherheit in der Hochschullaufbahn
Authors: Domke Katrin , Hoster Harry , Bessler Wolfgang , Brockhinke Andreas , Grill Leonhard , Jacob Timo , Jung Gregor , Küpper Jochen , Risse Thomas , Zeuch Thomas
Published: November 2009

Die Wissenschaftskarriere an einer Hochschule ist einseitig auf das Ziel Professur ausgerichtet. Was aber passiert mit den Wissenschaftlern, die zwar hochqualifiziert sind, aber nicht berufen werden? Deren über fünf oder sechs Jahre aufgebaute Arbeitsgruppe im wissenschaftlichen Nichts endet? Ein Hochschulsystem, das unterschiedliche Berufswege zulässt, könnte verhindern, dass gute und sehr gute Wissenschaftler den Hochschulen verloren gehen. Aus einem Positionspapier.1)
Robust ℋ︁2static output feedback design starting from a parameter‐dependent state feedback controller for time‐invariant discrete‐time polytopic systems
Authors: Moreira Heber R. , Oliveira Ricardo C. L. F. , Peres Pedro L. D.
Published: November 2009

This paper investigates the problem of computing robust ℋ︁2static output feedback controllers for discrete‐time uncertain linear systems with time‐invariant parameters lying in polytopic domains. A two stages design procedure based on linear matrix inequalities is proposed as the main contribution. First, aparameter‐dependentstate feedback controller is synthesized and the resulting gains are used as an input condition for the second stage, which designs the desiredrobuststatic output feedback controller with an ℋ︁2guaranteed cost. The conditions are based on parameter‐dependent Lyapunov functions and, differently from most of existing approaches, can also cope with uncertainties in the output control matrix. Numerical examples, including a mass–spring system, illustrate the advantages of the proposed procedure when compared with other methods available in the literature. Copyright © 2009 John Wiley & Sons, Ltd.
Tropane alkaloid profiling of hydroponic Datura innoxia mill. Plants inoculated with Agrobacterium rhizogenes
Authors: Jousse Cyril , Vu Thi Dao , Le Minh Tran Thi , Al Balkhi Mohamad Houssam , Molinié Roland , Boitel‐Conti Michèle , Pilard Serge , Mathiron David , Hehn Alain , Bourgaud Frédéric , Gontier Eric
Published: November 2009

Introduction – Hydroponics has been shown as a possible way to produce high quality plant biomass with improved phytochemical levels. Nevertheless, effects of plant biotic and abiotic environment can lead to drastic changes and plant growth conditions must be optimised.

Objective – To evaluate how much microbes and Agrobacterium rhizogenes TR7 wild strain may affect the tropane alkaloid profile in Datura innoxia Mill. plants cultivated in hydroponic conditions.

Methodology – Datura innoxia Mill. plants were cultivated in hydroponic with sterile or non‐sterile conditions. For half of the non‐sterile plants, Agrobacterium rhizogenes TR7 strain was added to the nutrient solution for hydroponics. The tropane alkaloid content of leaves and roots was analysed by UFLC/ESI‐HRMS and MS/MS. The metabolite profiles were compared using partial least square‐discriminant analysis.

Results – In sterile conditions, aerial parts contained more scopolamine than the roots. However, the diversity of tropane alkaloids was greater in roots. Furthermore, 21 known compounds and four non‐elucidated tropane alkaloids were found. The tropane alkaloid profile was shown to be statistically different between sterile and non‐sterile hydroponic conditions. The levels of 3‐acetoxy‐6‐hydroxytropane and 3‐hydroxylittorine were higher in plants inoculated with A. rhizogenes. Five other tropane compounds were found in higher amounts in non‐axenic control plants. Hyoscyamine and scopolamine total contents were much higher in the whole plant co‐cultivated with A. rhizogenes TR7 than in controls. Furthermore, the leaves and roots of axenic plants contained more alkaloids than non‐sterile ones.

Conclusion – In hydroponic conditions, microbes induced variations of the phytochemical levels. Addition of A. rhizogenes TR7 into the nutrient solutions improved the total hyoscyamine and scopolamine production. Copyright © 2009 John Wiley & Sons, Ltd.
The photographer and the greenhouse: how to analyse plant metabolomics data
Authors: Jansen Jeroen J. , Smit Suzanne , Hoefsloot Huub C.J. , Smilde Age K.
Published: November 2009

Introduction – Plant metabolomics experiments yield large amounts of data, too much to be interpretable by eye. Multivariate data analyses are therefore essential to extract and visualise the information of interest.

Objective – Because multivariate statistical methods may be remote from the expertise of many scientists working in the metabolomics field, this overview provides a step‐by‐step description of a multivariate data analysis, starting from the experiment and ending with the figures appearing in scientific journals.

Methodology – We developed a thought experiment that explores the relationship between the differences in nutrient levels and three plant developmental descriptors through photography of the greenhouse they grow in. Through this, multivariate data analysis, data preprocessing and model validation are illustrated. Finally some of the presented methods are illustrated by the analysis of a plant metabolomics dataset.

Conclusion – This paper will familiarise non‐specialised researchers with the main concepts in multivariate data analysis and allow them to develop and evaluate metabolomic data analyses more critically. Copyright © 2009 John Wiley & Sons, Ltd.
Pre‐admission clinics in day surgery. The ‘one‐stop shop’: tools and methods for practice improvement and service development
Authors: Gilmartin Jo , Chin Helen , Leonard Pam
Published: November 2009

The improvement of services aligned to day surgery is a still prominent topic in government policy debates and an important development area for many NHS trusts. This article attempts to describe the emergence of the ‘one‐stop shop’ approach in surgical outpatients and preoperative assessment clinics. It portrays the ways in which one clinical team moved their ideas forward to develop an integrated, multidisciplinary service, and describes the tools and methods they adopted to cross the borderlands between practice development and service improvement, to enable success. Copyright © 2009 John Wiley & Sons, Ltd.
A new generation of cross‐linkers for selective detection by MALDI MS
Authors: Paramelle David , Cantel Sonia , Enjalbal Christine , Amblard Muriel , Forest Eric , Heymann Michaël , Geourjon Christophe , Martinez Jean , Subra Gilles
Published: November 2009

We designed a new cross‐linker bearing a CHCA moiety. The use of the CHCA‐tagged cross‐linker JMV 3378 in conjunction with a neutral MALDI matrix α‐cyano‐4‐hydroxycinnamic methyl ester enabled specific signal enhancement in MALDI‐TOF MS of cross‐link containing peptides. Discrimination between modified and non‐modified peptides can be achieved by comparison of two spectra, one using CHCA and the other using the α‐cyano‐4‐hydroxycinnamic methyl ester matrix. The methodology was validated using cytochrome c and apo‐myoglobine as model proteins.
Peptide block copolymers by N‐carboxyanhydride ring‐opening polymerization and atom transfer radical polymerization: The effect of amide macroinitiators
Authors: Habraken Gijs J. M. , Koning Cor E. , Heise Andreas
Published: November 2009

The synthesis of polypeptide‐containing block copolymers combining N‐carboxyanhydride (NCA) ring‐opening polymerization and atom transfer radical polymerization (ATRP) was investigated. An amide initiator comprising an amine function for the NCA polymerization and an activated bromide for ATRP was used. Well‐defined polypeptide macroinitiators were obtained from γ‐benzyl‐L‐glutamate NCA, O‐benzyl‐serine NCA, and N‐benzyloxy‐L‐lysine. Subsequent ATRP macroinitiation from the polypeptides resulted in higher than expected molecular weights. Analysis of the reaction products and model reactions confirmed that this is due to the high frequency of termination reactions by disproportionation in the initial phase of the ATRP, which is inherent in the amide initiator structure. In some cases selective precipitation could be applied to remove unreacted macroinitiator to yield well‐defined block copolymers. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2009
Intercalation of solvent and polymer in galleries of mobile clay platelets by a Monte Carlo simulation
Authors: Pandey R.B. , Farmer B.L.
Published: November 2009

The intercalation of solvent particles and polymer chains of concentration Cw = 0.2 and Cp = 0.2, respectively, in a layer of (4) clay platelets is studied by a Monte Carlo simulation on a cubic lattice. Polymer chains and platelets are modeled by bond fluctuations. Besides the excluded volume, a set of polymer‐clay (cs) and solvent‐clay (ws) interactions with (i) cs = 1, ws = −2, (ii) cs = −2, ws = 1 and (iii) cs = ws = −2 are considered. The global dynamics of platelets is constrained due to the presence of three components, i.e., solvent, polymer, and platelets, which retain their interstitial spacing with well‐defined galleries. Intercalation of solvent particles and polymer chains (low molecular weight) occurs with their attractive interaction with the platelets, which further reinforces the layered clay morphology. The density profiles of the solvent particles are similar to previous studies with platelets in a mobile solvent. The density profile of polymer chains differs considerably from the platelets in a polymer matrix alone, particularly with its attractive interaction (ii). For the same attractive interaction of solvent and polymer chains with the clay platelets (iii), the solvent particles (the smallest constituents) intercalate the fastest in the clay galleries, whereas the intercalation of polymer chains decreases with their molecular weight. The polymer density profiles, both longitudinal (x) and transverse (y), show maxima peaks around outer platelets (surface) of the layer and decay sharply both in the adjacent galleries and in the bulk. The amplitude of oscillation in the transverse density profiles, a measure of the degree of intercalation, decreases with increasing molecular weight of the polymer. The intercalation of the polymer is driven by its attractive interaction at the low molecular weight, but reduces considerably at high molecular weight because of both entanglement and larger radius of gyration. Variations of the gyration radius of the diffusing polymer chains with molecular weight and interaction with the clay are consistent with the results of their corresponding density profiles. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 2487–2500, 2009
Effect of crosslink density on the pressure relaxation response of polycyanurate networks
Authors: Guo Jiaxi , Simon Sindee L.
Published: November 2009

The effect of crosslink density on the pressure‐volume‐temperature (PVT) behavior and on the pressure relaxation response for two polycyanurate networks is investigated using a custom‐built pressurizable dilatometer. Isobaric cooling measurements were made to obtain the pressure‐dependent glass transition temperature (Tg). The pressure relaxation studies were carried out as a function of time after volume jumps at temperatures in the vicinity of the pressure‐dependent Tg, and the pressure relaxation curves obtained were shifted to construct master curves by time‐temperature superposition. The reduced pressure relaxation curves are found to be identical in shape and placement, independent of crosslink density, when Tg is used as the reference temperature. The horizontal shift factors used to create the master curves are plotted as a function of the temperature departure from Tg (T − Tg), and they agree well with their counterparts obtained from the shear response. Moreover, the retardation spectra are derived from bulk compliance and compared to those from the shear. The results, similar to our previous work on polystyrene, indicate that at short times, the bulk and shear responses have similar underlying molecular mechanisms; however, the long‐time mechanisms available to the shear response, which increase with decreasing crosslink density, are unavailable to the bulk response. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 2477–2486, 2009
Electrospinning of poly(ethylene‐co‐vinyl acetate)/clay nanocomposite fibers
Authors: Liu Ying , Li Chunhua , Chen Shuang , Wachtel Ellen , Koga Tadanori , Sokolov Jonathan C. , Rafailovich Miriam. H.
Published: November 2009

Poly(ethylene‐co‐vinyl acetate)/clay nanocomposite fibers were fabricated using electrospinning. The fiber diameters were controlled by varying the polymer/chloroform concentration, which resulted in fibers with diameters ranging from 1 to 15 μm. The clay concentration was varied from 0.35 to 6.6 wt %. Scanning electron microscopy revealed that the fiber diameter increased with increasing clay concentration, whereas beading decreased. Transmission electron microscopy revealed a disruption of the spherulite structures by clay, which is consistent with heterogeneous nucleation. Shear modulus force microscopy indicated a reduction in melting point (Tm) with decreasing diameter for fibers thinner than 15 μm, which was confirmed by temperature dependent X‐ray diffraction data. For fibers thinner than 8 μm, the presence of clay further enhanced the reduction of Tm. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 2501–2508, 2009
Twinkling fractal theory of the glass transition: Rate dependence and time–temperature superposition
Authors: Wool Richard P. , Campanella Alejandrina
Published: November 2009

The twinkling fractal theory (TFT) of the glass transition temperature Tg provides a new method of analyzing rate effects and time–temperature superposition in amorphous materials. The rate dependence of Tg was examined in the light of new experimental and theoretical evidence for the nature of the dynamic heterogeneity near Tg. As Tg is approached from above, dynamic solid fractal clusters begin to form and eventually percolate rigidity at Tg. The percolation cluster is a solid fractal and to the observer, appears to “twinkle” as solid and liquid clusters interchange in dynamic equilibrium with a vibrational density of states g(ω) ∼ ω. The solid‐to‐liquid twinkling frequencies ωTF are controlled by the Boltzmann population of intermolecular oscillators in excited energy levels of their anharmonic potential energy functions U(x) such that ωTF = ω exp −B(T*2 − T2)/kT in which T* ≈ 1.2Tg. An oscillator changes from a solid to a liquid when a thermal fluctuation causes it to expand beyond its inflection point in the anharmonic potential. This leads to a continuous solid fraction Ps near Tg given by PS ≈ 1−[(1 − pc) T/Tg] where pc ≈ 1/2 is the rigidity percolation threshold. Since g(ω) is continuous from very low to very high frequencies, the complex twinkling dynamics existing near Tg produces a continuous relaxation spectrum with many different length scales and times associated with the fractal clusters. The twinkling frequencies control the kinetics of Tg such that for a given observation time t when the rate γ > 1/t, only those parts of the twinkling spectrum with ω > γ can contribute to relaxation or percolation upto time t. The most important results in this article are as follows: The TFT describes the rate dependence of Tg, both for DSC thermal heating/cooling rates and DMA frequencies as the classic Tg − lnγ law as Tg(γ) = Tgo + (k/2B) ln γ/γo in which the constant B = 0.3 cal/mol K2. The constant B appears quite universal for the 17 thermoset polymers investigated in this study and 18 linear polymers investigated by others. Many other amorphous metal and ceramic glass materials exhibited the same rate law but required a new B value approximately half that for polymers. The same B = 0.3 value was also used to successfully describe the TTS shift factors using the twinkling fractal frequencies ωTF = ωexp −B(T*2 − T2)/kT, as ln aT(TFT) = exp B(TR2 − T2)/kT, which gave comparable results with the classical WLF equation, log aT = [−C1(T − TR)]/[C2 + (T − TR)]. The advantage of the TFT over the WLF is that C1 and C2 are not universal constants and must be determined for every material, whereas the TFT uses one known constant B which appears to be the same for all polymers. The TFT has also been found to describe the strong and fragile nature of the viscosity behavior of liquids and the rate and temperature dependence of the yield stress in polymers. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 2578–2590, 2009
Structural Investigations of Composites Produced from Copper and Polypyrrole with a Dual PVD/PE‐CVD Process
Authors: Walter Christian , Brüser Volker , Quade Antje , Weltmann Klaus‐Dieter
Published: November 2009

Copper–polypyrrole composites were successfully produced with a dual plasma process. X‐ray photoelectron spectroscopy (XPS), X‐ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT‐IR) were used to characterise the structural properties. Topological and electrochemical investigations were also performed using atomic force and scanning electron microscopy (AFM, SEM) as well as cyclic voltammetry (CV) respectively. The results show that different composites were produced. When a low power was used, copper atoms bound to aromatic polymer structures were formed. Indications for the formation of electroactive copper–polypyrrole complexes are presented. Using higher power values, copper(I)oxide (ca. 3 nm) and copper nanoparticles (5–40 nm) embedded in a polymeric matrix were produced. Pulsing of the magnetron resulted in a modification of the chemical bonds within the samples.

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Intrinsic subtype‐associated changes in the plasma proteome in breast cancer
Authors: Nakshatri Harikrishna , Qi Guihong , You Jinsam , Kerry Bemis , Schneider Bryan , Zon Robin , Buck Charles , Regnier Fred , Wang Mu
Published: November 2009

Breast cancers are classified into five intrinsic subtypes: Luminal subtype A, Luminal subtype B, HER2+, Basal, and Normal‐like. In this study, we compared the plasma proteome of patients with Luminal A, Luminal B, HER2+, and Basal subtype with plasma from healthy individuals. Protein changes were considered significant if q‐value (false discovery rate) was less than 5%. The highest number of changes in the plasma proteome was observed in patients with Luminal type B followed by Basal type breast cancers. The plasma proteome of Luminal A and HER2+ breast cancer patients did not differ significantly from healthy individuals. In Basal breast cancer, a significant number of plasma proteins were downregulated compared with healthy individuals. Acute phase‐response proteins α‐glycoprotein orosomucoid 1 and serum amyloid protein P were specifically upregulated in the plasma of Luminal B breast cancer patients, suggesting prevalence of low‐grade inflammation. Proteins involved in immune response and free radical scavenging were downregulated in the plasma of Luminal B patients, which is in agreement with defective immune system observed in cancer patients. These results reveal intrinsic subtype specific changes in the plasma proteome that may influence tumor progression as well as the systemic effects of cancer.
A glimpse into the clinical proteome of human malaria parasites Plasmodium falciparum and Plasmodium vivax
Authors: Acharya Pragyan , Pallavi Rani , Chandran Syama , Chakravarti Harshini , Middha Sheetal , Acharya Jyoti , Kochar Sanjay , Kochar Dhanpat , Subudhi Amit , Boopathi Arun P. , Garg Shilpi , Das Ashis , Tatu Utpal
Published: November 2009

Malaria causes a worldwide annual mortality of about a million people. Rapidly evolving drug‐resistant species of the parasite have created a pressing need for the identification of new drug targets and vaccine candidates. By developing fractionation protocols to enrich parasites from low‐parasitemia patient samples, we have carried out the first ever proteomics analysis of clinical isolates of early stages of Plasmodium falciparum (Pf) and P. vivax. Patient‐derived malarial parasites were directly processed and analyzed using shotgun proteomics approach using high‐sensitivity MS for protein identification. Our study revealed about 100 parasite‐coded gene products that included many known drug targets such as Pf hypoxanthine guanine phosphoribosyl transferase, Pf L‐lactate dehydrogenase, and Plasmepsins. In addition, our study reports the expression of several parasite proteins in clinical ring stages that have never been reported in the ring stages of the laboratory‐cultivated parasite strain. This proof‐of‐principle study represents a noteworthy step forward in our understanding of pathways elaborated by the parasite within the malaria patient and will pave the way towards identification of new drug and vaccine targets that can aid malaria therapy.
Heterogeneous expressions of hepcidin isoforms in hepatoma‐derived cells detected using simultaneous LC‐MS/MS
Authors: Hosoki Takaaki , Ikuta Katsuya , Shimonaka Yasushi , Sasaki Yusuke , Yasuno Hideyuki , Sato Kazuya , Ohtake Takaaki , Sasaki Katsunori , Torimoto Yoshihiro , Saito Keiji , Kohgo Yutaka
Published: November 2009

Hepcidin, a key regulator of iron homeostasis, is known to have three isoforms: hepcidin‐20, ‐22, and ‐25. Hepcidin‐25 is thought to be the major isoform and the only one known to be involved in iron metabolism; the physiological roles of other isoforms are poorly understood. Because of its involvement in the pathophysiology of hereditary hemochromatosis and the anemia of chronic disease, the regulatory mechanisms of hepcidin expression have been extensively investigated, but most studies have been performed only at the transcriptional level. Difficulty in detecting hepcidin has impeded in vitro research. In the present study, we developed a novel method for simultaneous quantification of hepcidin‐20, ‐22, and ‐25 in the media from hepatoma‐derived cell lines. Using this method, we determined the expression patterns of hepcidin isoforms and the patterns of responses to various stimuli in human hepatoma‐derived cultured cells. We found substantial differences among cell lines. In conclusion, a novel method for simultaneous quantification of hepcidin isoforms is presented. Heterogeneous expressions of hepcidin isoforms in human hepatoma‐derived cells were revealed by this method. We believe our method will facilitate quantitative investigation of the role hepcidin plays in iron homeostasis.
Establishment and characterization of an androgen receptor‐dependent, androgen‐independent human prostate cancer cell line, LNCaP‐CS10
Authors: Ishikura Nobuyuki , Kawata Hiromitsu , Nishimoto Ayako , Nakamura Ryo , Ishii Nobuya , Aoki Yuko
Published: November 2009

BACKGROUND

Hormone refractoriness is a lethal event for advanced prostate cancer patients, but the mechanisms of the disease are not well elucidated, especially for the so‐called “outlaw” pathways of androgen receptor (AR)‐dependent, androgen‐independent hormone‐refractory prostate cancer.

METHODS

Androgen‐dependent prostate cancer LNCaP cells were treated with bicalutamide under an androgen‐depleted condition to obtain refractory cells. In the obtained cell line, LNCaP‐CS10, we analyzed the effects of androgen and bicalutamide on cell growth and prostate‐specific antigen (PSA) production. In addition, AR gene mutation, AR expression levels, and AR subcellular localizations were analyzed.

RESULTS

In LNCaP‐CS10, cell growth and PSA production were found under an androgen‐depleted condition and were induced by both R1881 and bicalutamide. Knocking down AR by siRNAs did suppress the growth and PSA production of LNCaP‐CS10 cells in the androgen‐depleted condition. In comparison to LNCaP, amplification or additional new mutations were not found in the AR genes, but AR nuclear translocation induced by bicalutamide was identified in the LNCaP‐CS10 cells. The growth and PSA production of xenografted LNCaP‐CS10 tumors, which secrete PSA not only in non‐castrated SCID mice but also in castrated SCID mice, were not inhibited by bicalutamide.

CONCLUSIONS

We have generated a bicalutamide‐resistant and androgen‐independent prostate cancer cell line, LNCaP‐CS10, with outlaw activation both in vitro and in vivo. The LNCaP‐CS10 cell line is beneficial for elucidating outlaw pathway mechanisms and evaluating the efficacy of new therapeutics for hormone‐refractory prostate cancer. Prostate 70: 457–466, 2010. © 2009 Wiley‐Liss, Inc.
A functional polymorphism in Pre‐miR‐146a gene is associated with prostate cancer risk and mature miR‐146a expression in vivo
Authors: Xu Bin , Feng Ning‐Han , Li Peng‐Chao , Tao Jun , Wu Deyao , Zhang Zheng‐Dong , Tong Na , Wang Jin‐Feng , Song Ning‐Hong , Zhang Wei , Hua Li‐Xin , Wu Hong‐Fei
Published: November 2009

BACKGROUND

A G > C polymorphism (rs2910164) which is located in the sequence of miR‐146a precursor, results in a change from a G:U pair to a C:U mismatch in its stem region. To explore whether rs2910164 plays any role in prostate cancer (CaP), we analyzed the association between miR‐146a polymorphism and risk of CaP and the expression of miR‐146a with different genotypes in CaP tissues in southern Chinese Han population.

MATERIALS AND METHODS

Two hundred fifty‐one CaP and 280 control subjects were included in the cancer association study, and 15 CaP tissue samples were used to test the expression of the miRNA precursors by real‐time quantitative reverse transcription PCR.

RESULTS

We found that subjects carrying CC homozygotes had a 0.65‐fold reduced risk (95% CI = 0.43–0.99) than those carrying GG/GC genotypes (P = 0.03), and the C allele displayed a lower prevalence of CaP compared with the G allele (OR = 0.73, 95% CI = 0.57–0.94, P = 0.01). Moreover, hsa‐miR‐146a quantification showed that homozygous carriers of the C‐variant had significantly decreased miRNA levels compared to the carriers of the GG/GC genotype.

CONCLUSIONS

The natural genetic variation in pre‐miR‐146a affects the amount of mature miR‐146a, contributes to the genetic predisposition to CaP. Prostate 70: 467–472, 2010. © 2009 Wiley‐Liss, Inc.
Colostrum and bioactive, colostral peptides differentially modulate the innate immune response of intestinal epithelial cells
Authors: Jørgensen Ann Louise Worsøe , Juul‐Madsen Helle Risdahl , Stagsted Jan
Published: November 2009

Characterization and identification of peptides with bioactivity from food have received considerable interest recently since such bioactive components must be adequately documented if they are part of functional food claims. We have characterized peptides from colostrum or those generated by a simulated gastrointestinal digest (GI) and tested them for bioactivity using murine intestinal (mICc12) cells and compared with bioactivity of intact colostrum. The peptides were recovered in the permeate after dialysis. The presence of peptides in the permeate was confirmed by C18 RP‐HPLC, determination of free amino termini and MALDI MS. The bioactivity of the intact colostrum and colostral peptides in the permeate was tested using mICc12 cells stimulated in the absence or presence of different bacterial ligands that mediate cellular activation through stimulation of Toll‐like receptors (TLR). Whereas intact colostrum generally reduced TLR‐mediated signaling, the isolated peptides seemed to either stimulate or reduce the immune response depending on the bacterial ligand used for stimulation. Interestingly, the most potent bioactive peptides originated from nondigested colostrum, which had only been subject to endogenous protease activity. Identified peptides in the nondigested colostrum originated exclusively from the casein fraction of colostrum as shown by MALDI MS/MS identification. Thus, multiple components with different bioactivities towards the innate immune response appear in bovine colostrum. Copyright © 2009 European Peptide Society and John Wiley & Sons, Ltd.
Microwave‐assisted TFA cleavage of peptides from Merrifield resin
Authors: Kluczyk Alicja , Rudowska Magdalena , Stefanowicz Piotr , Szewczuk Zbigniew
Published: November 2009

Microwave‐assisted (MW) reactions are of special interest to the chemical community due to faster reaction times, cleaner reactions and higher product yields. The adaptation of MW to solid phase peptide synthesis resulted in spectacular syntheses of difficult peptides. In the case of Merrifield support, used frequently in synthesis of special peptides, the conditions used in product cleavage are not compatible with off‐resin monitoring of the reaction progress. The application of MW irradiation in product removal from Merrifield resin using trifluoroacetic acid (TFA) was investigated using model tetrapeptides and the effects were compared with standard trifluoromethanesulphonic acid (TFMSA) cleavage using elemental analysis as well as chromatographic (HPLC) and spectroscopic (IR) methods. The deprotection of benzyloxycarbonyl and benzyl groups in synthetic bioactive peptides was analyzed using LC‐MS and MS/MS experiments. In a 5 min microwave‐assisted TFA reaction at low temperature, the majority of product is released from the resin, making the analytical scale MW‐assisted procedure a method of choice in monitoring the reactions carried out on Merrifield resin due to the short reaction time and compatibility with HPLC and ESI‐MS conditions. Copyright © 2009 European Peptide Society and John Wiley & Sons, Ltd.