bluuebunny/crossref_metadata_2025 huggingface dataset:
Association of ambulatory use of statins and beta‐blockers with long‐term mortality after vascular surgery
Authors: Barrett Thomas W. , Mori Motomi , De Boer David
Published: August 2007

BACKGROUND

The use of drugs to improve postoperative outcomes has focused on short‐term end points and centered on beta‐blockers. Emerging evidence suggests statins may also improve postoperative outcomes.

OBJECTIVE

We sought to ascertain if the ambulatory use of statins and/or beta‐blockers was associated with a reduction in long‐term mortality after vascular surgery.

DESIGN

Retrospective cohort study with a median follow‐up of 2.7 years.

SETTING

Regional multicenter study at Veterans Affairs medical centers.

PATIENTS

Three thousand and sixty‐two patients presenting for vascular surgery.

MEASUREMENTS

Patients were categorized as using statins or beta‐blockers if they filled a prescription for the study drug within 30 days of surgery. Survival analyses, propensity score methods, and stratifications by the revised cardiac risk index (RCRI) were performed.

RESULTS

Propensity‐adjusted ambulatory use of statins and beta‐blockers was associated with a reduction in mortality over the study period compared with nonuse of these medications hazard ratio [HR] = 0.78 [95% CI: 0.67–0.92], P = .0021, and number needed to treat (NNT) = 22 for statins; HR = 0.84 [95% CI: 0.73–0.96], P = .0106, and NNT = 30 for beta‐blockers. In addition, for propensity‐adjusted use of both statins and beta‐blockers compared with neither the HR was 0.56 [95% CI: 0.42–0.74] P < .0001, and NNT was 9. The RCRI confirmed combination statin and beta‐blocker use was beneficial at all levels of risk. Use of the combination study drugs by the highest‐risk patients was associated with a 33% decrease in mortality after 2 years (P = .0106).

CONCLUSIONS

The use of ambulatory statins alone or in combination with beta‐blockers is associated with a reduction in long‐term mortality after vascular surgery, and combination use benefits patients at all levels of risk. Journal of Hospital Medicine 2007;2:241–252. © 2007 Society of Hospital Medicine.
Synthesis of tritium‐labeled puerarin—a potential antidipsotropic agent
Authors: Lee D. Y. W. , Ji X. S. , Zhang X.
Published: August 2007

Puerarin 1 (8‐β‐D‐Glucopyranosyl‐4′‐7‐dihydroxyisoflavone, NPI‐031G) is the major isoflavone C‐glycoside isolated from Pueraria lobata, a traditional Chinese medicine widely used for the treatment of alcohol intoxication. In order to understand the mode of action of puerarin in the reward pathway of the central nervous system and to study its bioavailability and pharmacokinetics, we developed a synthetic route for the preparation of tritium‐labeled puerarin. The key intermediate 4 was obtained by trimethylsilyl protection of all hydroxyl groups followed by selective deprotection. The corresponding aldehyde 5 was obtained through the subsequent oxidation of the primary alcohol. Standard NaB[3H]4 reduction and hydrolysis produced the tritium‐labeled puerarin 6. Copyright © 2007 John Wiley & Sons, Ltd.
Synthesis of [2,3,4,5,6‐2H5]phenyl glucosinolate
Authors: Bialecki Jason B. , Ruzicka Josef , Attygalle Athula B.
Published: August 2007

Starting from commercially available [2,3,4,5,6‐2H5]benzoic acid, [2,3,4,5,6‐2H5]phenyl glucosinolate was synthesized. Under negative‐ion electrospray‐ionization mass spectrometric conditions, this compound affords a peak at m/z 399. Since this m/z value is not known from the ions derived from natural glucosinolates, the [2,3,4,5,6‐2H5]phenyl glucosinolate reported here is useful as an internal standard for the quantification of glucosinolates by negative‐ion mass spectrometry (MS) and liquid chromatography (LC)/MS techniques. Copyright © 2007 John Wiley & Sons, Ltd.
One‐step radiosynthesis of [18F]LBT‐999: a selective radioligand for the visualization of the dopamine transporter with PET
Authors: Dollé Frédéric , Helfenbein Julie , Hinnen Françoise , Mavel Sylvie , Mincheva Zoïa , Saba Wadad , Schöllhorn‐Peyronneau Marie‐Anne , Valette Heric , Garreau Lucette , Chalon Sylvie , Halldin Christer , Madelmont Jean‐Claude , Deloye Jean‐Bernard , Bottlaender Michel , Le Gailliard Joël , Guilloteau Denis , Emond Patrick
Published: August 2007

LBT‐999 (8‐((E)‐4‐fluoro‐but‐2‐enyl)‐3‐beta‐p‐tolyl‐8‐aza‐bicyclo[3.2.1]octane‐2‐beta‐carboxylicacid methyl ester) is a recently developed cocaine derivative belonging to a new generation of highly selective dopamine transporter (DAT) ligands (KD: 9 nM for the DAT and IC50 > 1000 nM for the serotonin and norepinephrine transporter). Initial fluorine‐18‐labelling of LBT‐999 was based on the robust and reliable two‐step radiochemical pathway often reported for such tropane derivatives, involving first the preparation of (E)‐1‐[18F]fluoro‐4‐tosyloxybut‐2‐ene followed by a N‐alkylation reaction with the appropriate nor‐tropane moiety. In the present work, a simple one‐step fluorine‐18‐labelling of LBT‐999 is reported, based on a chlorine‐for‐fluorine nucleophilic aliphatic substitution, facilitating as expected both automation and final high‐performance liquid chromatography (HPLC) purification. The process involves: (A) reaction of K[18F]F–Kryptofix®222 with the chlorinated precursor (3.5–4.5 mg) at 165°C for 10 min in DMSO (0.6 mL) followed by (B) C‐18 PrepSep cartridge pre‐purification and finally (C) semi‐preparative HPLC purification on a Waters Symmetry® C‐18. Typically, 3.70–5.92 GBq of [18F]LBT‐999 (> 95% chemically and radiochemically pure) could be obtained with specific radioactivities ranging from 37 to 111 GBq/µmol within 85–90 min (HPLC purification and Sep‐Pak‐based formulation included), starting from a 37.0 GBq [18F]fluoride batch (overall radiochemical yields: 10–16%, non‐decay‐corrected). Copyright © 2007 John Wiley & Sons, Ltd.
Differential EI fragmentation pathways for peracetylated C‐glycoside ketones as a consequence of bicyclic ketal ring structures
Authors: Price Neil P. J. , Momany Frank A. , Adeuya Anthony
Published: August 2007

Several C‐glycoside ketones and peracetylated C‐glycoside ketones have been synthesized from 13 structurally‐diverse aldoses sugars (including isotope labeled [1‐13C]Glc, [U‐13C]Glc, and [6, 6′‐2H2]Glc) via an aqueous‐based Knoevanagel condensation with aliphatic 1,3‐diketones. Sodium adduct molecular ions observed by MALDI‐TOF MS confirmed that the reactions are essentially quantitative, and that the acetylation products are the expected peracetylated C‐glycoside ketones, rather than cyclized ketofurans. Analysis of the peracetylated C‐glycoside ketones by gas chromatography‐EI‐MS show characteristic fragment ions that have been assigned to four distinct fragmentation pathways. Peracetylated aldohexose‐, aldopentose‐, and 6‐deoxyaldohexose‐C‐glycoside ketones fragment via gas phase furanoid intermediates. These data, and DFT calculations, indicate that the furanoid intermediates arise because the peracetylated C‐glycoside ketones adopt a bicyclic structure containing a 5‐member ketal ring. This ketal ring is the precursor of the furanoid rings in the gas phase. The 2‐deoxyhexose‐C‐glycoside ketones are unable to form an intramolecular 2‐ketal bond, and therefore undergo ion fragmentations via nonfuranoid pathways. Published in 2007 by John Wiley & Sons, Ltd.
The effects of weather and air pollution on cardiovascular and respiratory mortality in Santiago, Chile, during the winters of 1988–1996
Authors: Grass David , Cane Mark
Published: August 2007

This study quantifies the effects of stressful weather and elevated air pollution levels on cause‐specific mortality in Santiago, Chile, during the austral winters from 1988 to 1996. A temporal synoptic index (TSI) is used to form weather classes and air pollution classes. Prior applications of the TSI have formed classes solely on the basis of weather and may have systematically underestimated the impact of air pollution levels on daily mortality. In Santiago, the attribution of increased mortality risk was found to be largely dependent on the type of class formed (weather or pollution). High‐mortality weather classes were associated with cold, dry and high‐pressure conditions, while high‐mortality pollution classes were associated with elevated NO2 and PM10–2.5 concentrations. Cardiovascular disease mortality was more sensitive to weather conditions, and respiratory mortality was more sensitive to pollution levels. Respiratory mortality was most sensitive to stressful conditions at longer lag times (3–6 days), while cardiovascular mortality was most sensitive at shorter lag times (0–2 days). By understanding the relative magnitudes of health risks associated with stressful weather and air pollution conditions we can improve existing air pollution/weather watch systems and better anticipate future risks associated with global climate change. Copyright © 2007 Royal Meteorological Society
On ENSO impacts on European wintertime rainfalls and their modulation by the NAO and the Pacific multi‐decadal variability described through the PDO index
Authors: Zanchettin Davide , Franks Stewart W. , Traverso Pietro , Tomasino Mario
Published: August 2007

While strong relationships have previously been established between the El Niño/Southern Oscillation (ENSO) and climate variability in many parts of the world, previous analyses of ENSO impacts on European rainfalls have been variable and inconclusive. In this paper, the role and apparent interactions of a range of known teleconnections are assessed. It is shown that ENSO events do indeed appear to impact European rainfalls and that these impacts are likely to also depend on the concurrent state of the North Atlantic Oscillation (NAO) and the Pacific Decadal Oscillation (PDO). In particular, it is demonstrated that ENSO impacts most significantly on European wintertime rainfalls during positive (warm) phases of the PDO. Copyright © 2007 Royal Meteorological Society
Genetic relationships based on discrete dental traits: Basketmaker II and Mimbres
Authors: LeBlanc S. A. , Turner C. G. , Morgan M. E.
Published: August 2007

Investigations of the relationships between culture and biology among prehistoric populations of the southwestern United States can enhance our reconstruction of social interactions. The present study analyses the permanent dentition of Basketmaker II and Mimbres individuals from multiple sites using the Arizona State University dental anthropology system, and compares them with a regional sample. Discrete dental trait analysis provides a useful means for assessing the degree of genetic relatedness between populations when large comparative samples are available. Both in situ cultural change and population replacement have been posited as the dominant mechanism acting on Basketmaker and early Puebloan groups. We examine the relationship of these populations to probable Uto‐Aztecan speakers in light of the Uto‐Aztecan farmer migration hypothesis. The Basketmaker II complex, traditionally recognised as a distinct cultural unit, exhibits considerable population heterogeneity. Western Basketmakers appear to share biological ties with Uto‐Aztecan speakers, while Eastern Basketmakers do not, as predicted by the model. The relationship of the Mimbres to probable Uto‐Aztecan speakers is less clear because the Mimbres show only weak affinities to northern Mexican populations. Copyright © 2007 John Wiley & Sons, Ltd.
Advanced nucleating agents for polypropylene
Authors: Libster Dima , Aserin Abraham , Garti Nissim
Published: August 2007

The present short review aims to summarize advanced nucleating agents for polypropylene (PP). Reviewing the relevant literature, we focused on powerful nucleators that are capable of significantly increasing the crystallization temperature of the polymer at very low working concentrations and also serving as clarifying agents. The nucleation mechanism and efficiency of these compounds are discussed in detail. The nucleating agents were divided into groups according to their tendency to induce monoclinic (α), hexagonal (β), or orthorhombic (γ) PP cell geometries. The major α‐nucleators and clarifiers are sorbitol‐based compounds that speed‐up the polymer crystallization due to gelation phenomena and induction of epitaxial crystallization by the metal salts of substituted aromatic heterocyclic phosphate. Among β‐nucleators, N,N′‐dicyclohexyl‐2,6‐naphthalene dicarboxamide was found to be very efficient and its nucleation ability was highly concentration dependent. In addition, it was shown that nucleation efficiency of a nucleator can be significantly increased by a new dispersion method comprising its solubilization in a microemulsion. Moreover, the nucleator (HPN‐68) increased the γ‐modification present in the polymer. Copyright © 2007 John Wiley & Sons, Ltd.
Risk of recurrence in major central nervous system malformations between 1976 and 2005
Authors: Joó József Gábor , Beke Artúr , Papp Zoltán , Csaba Ákos , Rab Attila , Papp Csaba
Published: August 2007

Objective

The goal of the current publication is to review isolated central nervous system malformations (CSMs) using a database in excess of 75 000 cases, with special regard to the risk of recurrence of these malformations alone or in combination.

Methods

In the period between 1 January 1976 and 31 December 2005, among the 75 320 documented cases, consultations were requested due to earlier isolated CSMs in the patients' histories in 3030 cases (4.2%). Processing the data we only considered disorders of genetic origin, and that was why we excluded the cases due to intrauterine infection. Monogenically inherited malformations were also excluded from the analysis. The diagnosis of the malformations was based on the prenatal diagnosis of ultrasonography as well as the findings of the foetopathological examination.

Results

In 65% of the cases, the couples sought counselling because of malformation in a previous pregnancy. In these cases, the risk of recurrence was thought to be 5.2%, while in the case of two affected children this figure stood at 21.9%. Analysing the values for the risk of recurrence in 5‐year periods, neural tube defects (NTDs) (particularly anencephaly and spina bifida) showed a detectable decrease, which could be attributed to a growing use of folic acid supplementation around the time of conception and during pregnancy.

Conclusion

There is a clear decrease of risk of recurrence of NTDs, while in the case of the other CSMs in this study, there is no noteworthy chronological change in their risk of recurrence. Copyright © 2007 John Wiley & Sons, Ltd.
Synthesis of ω‐functionalized poly(1,3‐cyclohexadiene): addition of fluorescent functional group to the polymer chain end
Authors: Natori Itaru , Sato Hisaya , Natori Shizue
Published: August 2007

BACKGROUND: Poly(1,3‐cyclohexadiene) (PCHD) is of interest as a precursor for the synthesis of a new class of high‐performance hydrocarbon polymers. ω‐Functionalization of PCHD offers a new opportunity for the preparation of a variety of multifunctional PCHD derivatives.

RESULTS: ω‐Functionalized PCHD containing a fluorenyl (or anthracenyl) group at the polymer chain end was successfully synthesized by post‐polymerization reaction of poly(1,3‐cyclohexadienyl)lithium (PCHDLi) with alkyl halides containing a fluorescent functional group. The degree of nucleophilicity of PCHDLi and the control of side reactions were very important factors to achieve a high conversion for the post‐polymerization reactions of PCHDLi. The ω‐functionalized PCHDs obtained exhibited strong photoluminescence and the wavelength of the fluorescence was adjustable by changing the structure of the ω‐functional group.

CONCLUSION: ω‐Functionalized PCHD is a preferable precursor that can be utilized to obtain a new class of multifunctional hydrocarbon polymers containing six‐membered rings in the main chain. Copyright © 2007 Society of Chemical Industry
Methoxy poly(ethylene glycol)‐block‐poly(D,L‐lactic acid) copolymer nanoparticles as carriers for transdermal drug delivery
Authors: Li Jun , Zhai Yinglei , Zhang Bin , Deng Liandong , Xu Yongshen , Dong Anjie
Published: August 2007

This work evaluates the transdermal drug delivery properties of amphiphilic copolymer self‐assembled nanoparticles by skin penetration experiments in vitro. Paclitaxel‐loaded methoxy poly(ethylene glycol)‐block‐poly(D,L‐lactic acid) diblock copolymer nanoparticles (PNPs) were prepared by a solid dispersion technique and were applied to the surface of excised full‐thickness rat skin in Franz diffusion cells. HPLC, transmission electron microscopy, Fourier transform infrared spectroscopy and 1H NMR were used to assay the receptor fluid. The results show that the amphiphilic copolymer nanoparticles with the entrapped paclitaxel are able to penetrate rat skin. Ethanol can improve the delivery of PNPs and increase the cumulative amount of paclitaxel in the receptor fluid by 3 times. Fluorescence microscopy measurements indicate that the PNPs can penetrate the skin not only via appendage routes including sweat ducts and hair follicles but also via epidermal routes. Copyright © 2007 Society of Chemical Industry
New organic semiconductor materials: electrical conductivity, thermal properties and application of voltage‐controlled negative resistance device of poly[(2‐acrylamido‐2‐methyl‐1‐propanesulfonic acid)‐co‐(maleic acid)]
Authors: Yakuphanoglu Fahrettin , Soykan Cengiz , Coşkun Ramazan
Published: August 2007

BACKGROUND: Electrical conductivity, photoconductivity, voltage‐controlled negative resistance and thermal properties of copolymers of 2‐acrylamido‐2‐methyl‐1‐propanesulfonic acid and maleic acid were investigated in order to obtain new organic semiconductors.

RESULTS: The room temperature conductivity of three different copolymers was found to be in the range 1.28 × 10−8 − 1.20 × 10−7 S cm−1. The dark‐ and photo‐current‐voltage characteristics indicate that the copolymers exhibit voltage‐controlled differential negative resistance behaviour. The electrical conductivity of the polymers increases by photo‐illumination, suggesting that the polymers exhibit photoconductivity. The width of the exponential tail in the forbidden band gap of the three polymers was determined via the transient photocurrent technique and E0 values were in the range 34.4–36.49 meV.

CONCLUSION: The results suggest that the copolymers could be used as organic semiconductor materials. Copyright © 2007 Society of Chemical Industry
Development of a robust hydrogel system based on agar and sodium alginate blend
Authors: Meena Ramavatar , Chhatbar Mahesh , Prasad Kamalesh , Siddhanta Arup K
Published: August 2007

BACKGROUND: As part of an ongoing research and development programme of our laboratory on functional modification of seaweed polysaccharides for preparing hydrogels with improved properties, we report herein the preparation of a robust hydrogel system based on grafting of agar and sodium alginate blend (Agar/Na‐Alg) with acrylamide (AAm) to obtain the copolymer Agar/Na‐Alg‐graft‐PAAm.

RESULTS: A robust hydrogel system with superior absorbency and pH resistance has been developed based on a PAAm‐grafted seaweed polysaccharide blend of Agar/Na‐Alg. The blend (Agar/Na‐Alg) and grafted product (Agar/Na‐Alg‐graft‐PAAm) were evaluated using Fourier transform infrared spectroscopy, X‐ray diffraction, thermogravimetric analysis, swelling capacity, rheology and scanning electron microscopy. The swelling capacity of the grafted copolymer exhibited an enhancement over that of the blend from 14 to 24 g g−1 in acidic medium. The blend and grafted copolymer produced hydrogels with lower gelling points of 31 and 29 °C and gel strengths were 170 and 120 g cm−2, respectively.

CONCLUSION: This study constitutes an example of value addition of seaweed polysaccharides targeting new applications. The copolymer hydrogel may be useful in health, personal care and agricultural applications. Copyright © 2007 Society of Chemical Industry
Spot arrays on modified glass surfaces for efficient SPOT synthesis and on‐chip bioassay of peptides
Authors: Kim Do‐Hyun , Shin Dong‐Sik , Lee Yoon‐Sik
Published: August 2007

To make SPOT synthesis of peptides and their assays on glass surfaces more convenient, a simple method for making spot arrays on a slide glass was designed through patterning with a photoresist and perfluorination followed by amination with various silane compounds and polymers. With these spot‐arrayed glass surfaces, we could measure the coupling completion of each Fmoc amino acid on the glass surface by direct fluorescence analysis after fluorescence‐labeling the amino groups on the surface of each spot. Then we synthesized several types of decapeptides and HPQ‐pentapeptides on the spot‐arrayed glasses and identified the optimal surface condition for stepwise peptide coupling and on‐chip bioassay. After optimizing the surface conditions, we synthesized a model library of biotin‐Gly‐Ala‐P1‐Gly (P1: one of 19 amino acids) and successfully replicated the well‐known α‐chymotrypsin subsite specificities through Cy5‐streptavidin binding to the remaining biotin on the surface after the enzymatic digestion. Copyright © 2007 European Peptide Society and John Wiley & Sons, Ltd.
Applicability of the MCNPX particle transport code for determination of the source correction effect in positron lifetime measurements on thin polymer films
Authors: Urban‐Klaehn J. M. , Spaulding R. , Hunt A. W. , Peterson E. S.
Published: August 2007

The method presented herein uses the MCNPX Monte Carlo particle transport code to track individual positrons and other particles through geometry that accounts for the detectors, backing foils, samples and sources with their actual sizes, positions and material characteristics. Polymer material, polydimethylsiloxane (PDMS), with different thickness of films served as samples. The excellent agreement between the experimental results and the MCNPX simulation of source correction effects for varied positron sources and different film thicknesses validates the applicability of the MCNPX code. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Characterization of ion beam‐induced SiC‐OI structures by positron annihilation spectroscopy
Authors: Maekawa M. , Yu R. S. , Kawasuso A.
Published: August 2007

Effect of oxygen ion implantation to SiC at 600 °C has been studied by positron annihilation spectroscopy using energy‐variable slow positron beams. The Doppler broadening of annihilation radiation and positron lifetime measurements showed that vacancy defects survive and no SiO2 layer is formed in the as‐implanted state. Following post‐implantation annealing at 1400 °C, vacancy clusters were removed. Furthermore, a SiO2‐like layer is formed in the oxygen‐implanted region. An interface layer, which resembles that of the SiO2/SiC produced by conventional oxidation, was also found. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
High moderation efficiency positron beamline
Authors: Wu Y. C. , Chen Y. Q. , Wu S. L. , Chen Z. Q. , Wang S. J. , Greaves R. G.
Published: August 2007

A new positron beam system, which has high moderation efficiency and can measure positron lifetime spectra, has been constructed at Wuhan university. A solid neon moderator with about 1% moderation effeciency is used. Secondary electron time‐tagging can be used to measure the positron annihilation lifetime. A target chamber has been designed for positron annihilation lifetime spectroscopy (PALS), Doppler broadening (DB) and coincidence Doppler broadening (CDB). The preliminary beam parameters are: a slow positron flux of 5 million per second for 40 mCi 22Na radioactive isotope, a positron energy spread as narrow as 2.0eV, and a moderator decay rate of 4% per day. Variable energy Doppler broadening annihilation radiation data for stainless steel samples are shown, which demonstrate the capabilities of the system. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Hydrogen‐damaged defects near the surface in heavily deformed iron and steels investigated by slow positron annihilation spectroscopy
Authors: Wu Y. C. , Jean Y. C.
Published: August 2007

Hydrogen‐damaged defects of heavily deformed iron, AISI 304‐, and 316‐stainless steels were investigated by measuring Doppler broadening energy spectra (DBES) of positron annihilation radiation. It is interestingly found that S‐parameter as a function of energy on three kinds of deformed samples falls into the similar variation, independent of chemical elements and impurities. A larger S value near the surface in deformed and hydrogen‐damaged samples than in samples without hydrogen‐damaged samples is because of the additional larger‐sized defects (e.g. voids) induced due to hydrogen damage. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Positron lifetime study on the degradation of LaNi5 and LaNi4.8Sn0.2 during hydrogen absorption‐desorption cycling
Authors: Araki Hideki , Date Ryousuke , Sakaki Kouji , Mizuno Masataka , Shirai Yasuharu
Published: August 2007

LaNi5 and LaNi4.8Sn0.2 alloys have been subjected to pressure‐induced cycling tests at 248 K under a hydriding condition at a hydrogen pressure of 3 MPa and under a dehydriding condition of evacuating by a rotary pump. At the beginning of cycling the hydrogen absorbing capacity of LaNi5 was larger than that of LaNi4.8Sn0.2. However, the capacity of LaNi5 was markedly decreased by the cycling, whereas the capacity of LaNi4.8Sn0.2 was hardly changed. After 100 cycles, the capacity of LaNi5 became smaller than that of LaNi4.8Sn0.2. On the other hand, it was also found that the increase in the positron mean lifetime by the cycling for LaNi4.8Sn0.2 was smaller than that for LaNi5, revealing that substitution of Sn suppresses the formation of vacancy during the cycling. This result suggests that the degradation in hydrogen absorbing capacity should be attributed at least partly to trapping of hydrogen at excess vacancy formed by hydriding. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On the precipitation sequence in a Ni‐based superalloy: A Coincidence Doppler Broadening study
Authors: Macchi C. E. , Somoza A. , Santos G. , Petkov M. , Lynn K. G.
Published: August 2007

The precipitation sequence at 700 °C of the Ni3(Ti,Al)‐type ordered γ' phase in the commercial nickel‐based superalloy Inconel X‐750 was investigated using Coincidence Doppler Broadening (CDB) technique. The results obtained are discussed in terms of positron annihilation in two well‐defined states: one corresponding to the matrix (γ phase) and a second related to the γ' precipitates. Between these two aging stages, CDB distributions corresponding to selected intermediate aging treatments could be presented exactly, within the experimental scatter, as a linear combination of the γ and γ' signatures. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Positron diffusion in the liquid metal phase
Authors: Matsushita Y. , Kitahata H. , Kanazawa I.
Published: August 2007

We have analyzed the positron diffusion length date in the liquid phase of In metal from the view point of the restoration of the spontaneously broken density around the positron. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Study of defects and phase transformation in a Fe‐Mn‐Si‐Cr‐Ni alloy by positron annihilation method
Authors: Mostafa Khaled M. , Van Caenegem N. , De Baerdemaeker J. , Segers D. , Houbaert Y.
Published: August 2007

Defects in Fe‐Mn‐Si‐Cr‐Ni samples were studied at room temperature. Steel samples were deformed during a tensile experiment up to a strain of 17%. The evolution of the defect structure was followed by Doppler broadening measurements. Before and after the deformation the samples were also characterised by positron lifetime measurements. Light optical microscopy (OM) gave information about the different microstructural phases that exist in the deformed and the undeformed alloys. During deformation a martensitic ε phase is induced. The size of the martensite plates increases with increasing deformation. The S‐W plot during the deformation is not linear. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Atomic structure and positron lifetime in the metallic glass Zr55Cu30Ni5Al10
Authors: Sugita K. , Matsumoto M. , Mizuno M. , Araki H. , Shirai Y.
Published: August 2007

Zr‐based metallic glasses have superior characteristics such as mechanical strength, corrosion resistance and precision casting ability. From positron lifetime measurements, a negative temperature dependence of the mean positron lifetime above room temperature was reported and ascribed to the presence of shallow traps. However, the trapping sites remain unknown under the present circumstances. To get a further understanding of the experimental positron lifetime value, the positron density distribution and the lifetime in the Zr‐based metallic glass Zr55Cu30Ni5Al10 have been calculated. The calculation shows that the positrons are annihilated inhomogeneously and most positrons are annihilated preferentially around Cu/Al. These results indicate that the positron lifetime not exactly reflects the total free volume. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Temperature dependence of Cu precipitation in neutron irradiated Fe‐Cu alloys
Authors: Xu Qiu , Yoshiie Toshimasa , Sato Koichi
Published: August 2007

The formation of Cu precipitates was investigated in two Fe‐Cu binary model alloys irradiated with fission neutrons at doses from 1.6×10–4 to 6×10–3 dpa (displacement per atom) at temperatures from 473 to 723 K. The results of coincidence Doppler broadening (CDB) measurements indicated that Cu precipitates formed in all cases. Microvoids formed at low temperatures of 473 and 573 K, but they were not identified at high temperatures of 673 and 723 K. At low temperatures (≤573 K), although Cu precipitates formed by vacancy migration, the growth of precipitates was mainly dominated by the formation of microvoids. At high temperatures (≥673 K), however, Cu precipitates formed directly by vacancy migration. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Positron microscopic analysis of crack failure in stainless steels
Authors: Yu R. S. , Maekawa M. , Miwa Y. , Hirade T. , Nishimura A. , Kawasuso A.
Published: August 2007

Employing a focused positron beam with a lateral resolution of approximately 30 μm, we performed two dimensional scanning studies of stainless steels with stress corrosion cracking (SCC). A stainless steel with fatigued crack was also measured for comparison. Results suggest a quite unique failure mechanism for the specimen with SCC. In contrast to normal crack propagation effect associated with vacancies and dislocations, smaller Doppler broadening line shape (S) parameters were observed around the SCC crack tip than those corresponding to the undamaged area. It could be ascribed to some chemical influences, like oxidation, took place at grain boundaries. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The dynamics of the North Atlantic Oscillation during the summer season
Authors: Feldstein Steven B.
Published: August 2007

This study examines the dynamical characteristics of the North Atlantic Oscillation (NAO) life cycle for the summer season. The diagnostic techniques, which use NCEP/NCAR Reanalysis data, include composites of the 300 hPa stream function, a projection analysis with each term in the stream‐function tendency equation, and composites of potential temperature on the 2 PVU potential‐vorticity surface.

For both phases, the NAO life cycles take about two weeks to complete. The NAO anomalies are found to be driven by both high‐frequency (period < 10 days) and low‐frequency (period > 10 days) transient eddy vorticity fluxes. The decay of the NAO is accomplished by both low‐frequency transient eddy vorticity fluxes and horizontal divergence. The breaking of synoptic‐scale waves is found to play a crucial role during the summer NAO life cycle. For the positive NAO phase, the southern centre of action of the dipole arises from anticyclonic wave‐breaking, and the northern centre of action from anticyclonic wave‐breaking followed by trough intensification. For the negative NAO phase, both centres of action develop from cyclonic wave‐breaking. These characteristics are very similar to those for the NAO life cycle during the winter season, the primary differences being the weaker anomalies, shorter zonal and meridional scales, and less intense wave‐breaking of the summer NAO. Copyright © 2007 Royal Meteorological Society
Bias estimation of Doppler‐radar radial‐wind observations
Authors: Salonen K. , Järvinen H. , Eresmaa R. , Niemelä S.
Published: August 2007

Doppler radars provide measurements of the radar radial wind component at high spatial and temporal resolution. The variational data‐assimilation framework enables direct use of these measurements in numerical weather prediction models. Bias estimation of Doppler‐radar radial winds requires special attention because of the azimuthal scanning strategy. Calculation of the bias statistic over all azimuthal directions results in a near‐zero value even in the presence of systematic differences between the measured and modelled wind speed and direction. This paper describes a method for bias estimation of Doppler‐radar radial‐wind observations. Intercomparison between the estimated biases of Doppler‐radar and radiosonde wind observations reveals that the wind speed and direction biases are of comparable magnitude. Copyright © 2007 Royal Meteorological Society
Photoactivated excited states of DNA repair photolyase: Dynamical and semiempircal identification
Authors: Zheng Xuehe , Ly Ngan M. , Stuchebrukhov Alexei A.
Published: August 2007

DNA damage caused by UV light radiation is often naturally repaired in a process initiated by excited state electron transfer from the photoactivated photolyase enzyme to the DNA cyclobutane pyrimidine dimer lesion. The active cofactor in the excited state electron transfer in the photolyase is the two‐electron fully reduced form of the flavin adenine dinucleotide (FADH−). To calculate electron tunneling matrix element and model the DNA binding with photolyase, the LUMO of the FADH− calculated using extended Huckel method was previously chosen from the SCF wavefunctions. Recently, the DNA–photolyase complex was crystallized in its bound form, in good agreement with our previous model in even minute details at the active site. Here we carry out molecular dynamics simulation of the entire complex using the new experimental structure of Anacystis nidulans and identify the low‐lying photoactivated states of the enzyme for the dynamical confirmations. Our results from ZINDO/S CIS calculations are compared with experimental UV spectra, and their implications for excited state electron transfer and energy transfer are discussed. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2007
A reduction paradigm for output regulation
Authors: Celani F. , Isidori A. , Marconi L.
Published: August 2007

The goal of this paper is to provide a reduction paradigm for the design of output regulators which can be of interest for nonlinear as well as linear uncertain systems. The main motivation of the work is to provide a systematic design tool to deal with non‐minimum‐phase uncertain systems for which conventional high‐gain stabilization methods are not effective. The contribution of the work is two‐fold. First, this work extends a previous reduction paradigm for output regulation of nonlinear systems. Furthermore, in the case of the uncertain controlled dynamics being linear, we show how the proposed framework leads to a number of systematic design tools of interest for non‐minimum‐phase linear systems affected by severe uncertainties. A numerical control example of a linearized model of an inverted pendulum on a cart is presented. Copyright © 2007 John Wiley & Sons, Ltd.
Improved algorithms for the random cluster graph model
Authors: Shamir Ron , Tsur Dekal
Published: August 2007

We model noisy clustering data using random graphs: Clusters correspond to disjoint sets of vertices. Two vertices from the same set (resp., different sets) share an edge with probability p (resp., r < p). We give algorithms that reconstruct the clusters from the graph with high probability. Compared to previous studies, our algorithms have lower time complexity and apply under wider parameter range. © 2007 Wiley Periodicals, Inc. Random Struct. Alg., 2007
Microfabrication and imaging XPS analysis of ITO thin films
Authors: Li Ying , Zhao Gaoyang , Zhi Xiao , Zhu Tao
Published: August 2007

In this paper the microfabrication of ITO (tin‐doped indium oxide) films by the sol–gel process combined with chemical modification is presented. The microfabricated ITO thin film could be obtained through a one‐step process that combines film patterning with film leaching. The morphology and chemical components of the patterned ITO thin films were assessed by microscopy and XPS, respectively. Imaging XPS analysis is an effective way to evaluate the quality of the fine patterning. Copyright © 2007 John Wiley & Sons, Ltd.
A Bayesian analysis of doubly censored data using a hierarchical Cox model
Authors: Zhang Wei , Chaloner Kathryn , Cowles Mary Kathryn , Zhang Ying , Stapleton Jack T.
Published: August 2007

Two common statistical problems in pooling survival data from several studies are addressed. The first problem is that the data are doubly censored in that the origin is interval censored and the endpoint event may be right censored. Two approaches to incorporate the uncertainty of interval‐censored origins are developed, and then compared with more usual analyses using imputation of a single fixed value for each origin. The second problem is that the data are collected from multiple studies and it is likely that heterogeneity exists among the study populations. A random‐effects hierarchical Cox proportional hazards model is therefore used.

The scientific problem motivating this work is a pooled survival analysis of data sets from three studies to examine the effect of GB virus type C (GBV‐C) coinfection on survival of HIV‐infected individuals. The time of HIV infection is the origin and for each subject this time is unknown, but is known to lie later than the last time at which the subject was known to be HIV negative, and earlier than the first time the subject was known to be HIV positive. The use of an approximate Bayesian approach using the partial likelihood as the likelihood is recommended because it more appropriately incorporates the uncertainty of interval‐censored HIV infection times. Copyright © 2007 John Wiley & Sons, Ltd.
Synergistic Antiproliferative Effects of γ‐Tocotrienol and Statin Treatment on Mammary Tumor Cells
Authors: Wali Vikram B. , Sylvester Paul W.
Published: August 2007

Statins are potent inhibitors of 3‐hydroxy‐3‐methylglutaryl‐coenzyme A (HMGCoA) reductase and display anticancer activity, but their clinical use is limited by their high‐dose toxicity. Similarly, γ‐tocotrienol, an isoform of vitamin E, also reduces HMGCoA reductase activity and displays potent anticancer activity. Studies were conducted to determine if combined low dose treatment of γ‐tocotrienol with individual statins resulted in a synergistic antiproliferative effect on neoplastic mouse +SA mammary epithelial cells. Treatment with 3–4 μM γ‐tocotrienol or 2–8 μM simvastatin, lovastatin or mevastatin alone resulted in a significant decrease, whereas treatment with 10–100 μM pravastatin had no effect on +SA cell growth. However, combined treatment of subeffective doses (0.25 or 10 μM) of individual statins with 0.25–2.0 μM γ‐tocotrienol resulted in a dose‐responsive synergistic inhibition in +SA cell proliferation. Additional studies showed that treatment with subeffective doses of individual statins or γ‐tocotrienol alone had no effect, whereas combined treatment of these compounds resulted in a relatively large decrease in intracellular levels of phosphorylated (activated) MAPK, JNK, p38, and Akt. These findings strongly suggest that combined low dose treatment of γ‐tocotrienol with individual statins may have potential value in the treatment of breast cancer without causing myotoxicity that is associated with high dose statin treatment.
Characterization and In‐vitro Permeation Study of Stearic Acid Nanoparticles containing Hinokitiol
Authors: Cho Seong Min , Lee Hyeon Yong , Kim Jin‐Chul
Published: August 2007

Lipid nanoparticles containing hinokitiol (HKL) were prepared by a melt–emulsification method. Stearic acid was used as a lipid for the matrix material of the nanoparticles. According to results from transmission electron microscopy (TEM) and dynamic light scattering (DLS), most of the nanoparticles were less than 100 nm. When nanoparticles containing HKL were scanned on a differential scanning calorimeter, no endothermic peak of HKL was observed. This means that HKL in the lipid matrix of the nanoparticles is in a dissolved state. In an 18‐h permeation study using hairless mouse skin mounted on a diffusion cell, the amount of HKL encapsulated in the nanoparticles transported to the receptor cell was five to ten times more than for HKL dissolved either ethanol or propylene glycol. Therefore, stearic acid nanoparticles strongly enhanced permeation of the skin by HKL.
Effect of exogenous vitamin E on proliferation and cytokine production in peripheral blood mononuclear cells from patients with tuberculosis
Authors: Hernández Jesús , Garibay-Escobar Adriana , Mendoza-Mendoza Andrés , Pinelli-Saavedra Araceli , Valenzuela Olivia
Published: August 2007

Micronutrient deficiencies are frequently associated with tuberculosis (TB) worldwide. We tested the effect of exogenous vitamin E on proliferation and cytokine production of peripheral blood mononuclear cells (PBMC) from TB patients and healthy purified protein derivative (PPD)+ volunteers. Proliferation was stimulated with mycobacterial antigen (PPD) and evaluated by the incorporation of tritiated thymidine in PBMC cultured with or without 50 μm-vitamin E for 6 d. Cytokine production (IL-2 and interferon (IFN)-γ) was determined by intracellular cytokine staining and by ELISA in the supernatant of PBMC stimulated for 24 h with phytohaemagglutinin or PPD. Our results show that culture with vitamin E increased (P ≤ 0·05) the antigen-induced proliferation of PBMC in TB patients but not in healthy PPD+ volunteers. No significant changes in the number of cytokine-producing cells or in the production of IFN-γ were observed with vitamin E treatment. These results indicate that vitamin E may enhance the antigen-specificin vitroresponse of PBMC from TB patients.
The effects of regular consumption of short-chain fructo-oligosaccharides on digestive comfort of subjects with minor functional bowel disorders
Authors: Paineau Damien , Payen Flore , Panserieu Suzanne , Coulombier Geneviève , Sobaszek Annie , Lartigau Isabelle , Brabet Marylène , Galmiche Jean-Paul , Tripodi Dominique , Sacher-Huvelin Sylvie , Chapalain Véronique , Zourabichvili Othar , Respondek Frédérique , Wagner Anne , Bornet Francis R. J.
Published: August 2007

A comparative, randomised, double-blind trial was performed in the medical departments of five hospitals to study the effects of regular consumption of short-chain fructo-oligosaccharides (sc-FOS) on the digestive comfort of subjects with minor functional bowel disorders (FBD). In step 1, 2235 subjects were questioned to assess the incidence and intensity of digestive disorders. In step 2, 105 of these patients diagnosed with minor FBD were randomised into two groups to receive either 5 g sc-FOS or 5 g placebo (sucrose and maltodextrins) per d over a 6-week period. The incidence and intensity of digestive disorders were assessed at the end of the treatment period (day 43) using the step 1 questionnaires. A quality-of-life questionnaire was also completed at the start and end of the treatment period to assess potential effects on well-being and social performance. In step 1, 44 % of the subjects questioned presented FBD, of whom 57·1 % suffered from minor FBD. In step 2, on day 43, the intensity of digestive disorders decreased by 43·6 % in the sc-FOS group v. a 13·8 % increase in the placebo group (P = 0·026). Symptoms were experienced less frequently by 75·0 % of subjects in the sc-FOS group, while 53·8 % of controls experienced no change (P = 0·064). Using the functional digestive disorders quality of life questionnaire, the discomfort item scores increased in the sc-FOS group (P = 0·031). However, expressed as change in quality of life (improvement, worsening or unchanged), daily activities were significantly improved in the sc-FOS group (P = 0.022). Regular consumption of sc-FOS may improve digestive comfort in a working population not undergoing medical treatment.
Disruption of lipid metabolism in the liver of the pregnant rat fed folate-deficient and methyl donor-deficient diets
Authors: McNeil Christopher J. , Hay Susan M. , Rucklidge Garry J. , Reid Martin , Duncan Gary , Maloney Christopher A. , Rees William D.
Published: August 2007

The importance of folic acid and the methionine cycle in fetal development is well recognised even though the mechanism has not been established. Since the cycle is active in the maternal liver, poor folate status may modify hepatic metabolism. Pregnant rats were fed diets deficient in folic acid (–F) or in three key methyl donors, folic acid, choline and methionine (–FLMLC) and the maternal liver was analysed on day 21 of gestation. Two-dimensional gel electrophoresis of soluble proteins identified differentially abundant proteins, which could be allocated into nine functional groups. Five involved in metabolic processes, namely, folate/methionine cycle, tyrosine metabolism, protein metabolism, energy metabolism and lipid metabolism, and three in cellular processes, namely, endoplasmic reticulum function, bile production and antioxidant defence. The mRNA for sterol regulatory element-binding protein-1c and acetyl-CoA carboxylase-1 (fatty acid synthesis) were decreased by both –F and –FLMLC diets. The mRNA for PPARα and PPARγ and carnitine palmitoyl transferase (fatty acid oxidation) were increased in the animals fed the –FLMLC diets. Changes in the abundance of proteins associated with intracellular lipid transport suggest that folate deficiency interferes with lipid export. Reduced fatty acid synthesis appeared to prevent steatosis in animals fed the –F diet. Even with increased oxidation, TAG concentrations were approximately three-fold higher in animals fed the –FLMLC diet and were associated with an increase in the relative abundance of proteins associated with oxidative stress. Fetal development may be indirectly affected by these changes in hepatic lipid metabolism.
Docosahexaenoic acid is associated with endosteal circumference in long bones in young males with cystic fibrosis
Authors: Gronowitz Eva , Lorentzon Mattias , Ohlsson Claes , Mellström Dan , Strandvik Birgitta
Published: August 2007

In children, but not adults with cystic fibrosis (CF), associations between essential fatty acids (FA) and bone mass have been reported. Low bone mineral density (BMD) is common in these patients. Previously we found a normal annual increase of BMD, suggesting a potential for attaining normal bone mass. The aim of the present study was to investigate phospholipid FA pattern in relation to bone in young adult men with CF compared with healthy controls. Fourteen male patients with CF were compared with forty-two healthy controls, using dual-energy X-ray absorptiometry for total bone, lumbar spine and femur and peripheral quantitative computerised tomography for tibia and radius. A questionnaire concerning physical activity and nutrition was used. FA in serum phospholipids were measured using capillary GLC. CF patients did not differ in physical activity and anthropometry from controls. There were no differences in bone parameters between the two groups, but patients chronically colonised withPseudomonas aeruginosahad lower BMD than non-colonised patients. The trabecular BMD in the tibia differed between patients and controls, but not after adjustment for age and weight. The endosteal circumference of the radius was significantly associated with serum phospholipid concentration of DHA and inversely with then-6:n-3 FA ratio in CF patients but not in controls. The present study showed that young physically active adult males with classical CF obtained similar bone mass as controls, although influenced by pseudomonas colonisation. The association between DHA and long bone endosteal circumference suggested a later peak bone mass in those with CF compared with controls.