bluuebunny/crossref_metadata_2025_split huggingface dataset:
Self‐assembled structures in d8‐polystyrene‐block‐polyisoprene/polystyrene blends in the weak segregation regime: SAXS and TEM study
Authors: Holoubek Jaroslav , Baldrian Josef , Hromádková Jiřina , Steinhart Miloš 
Published: May 2009

AbstractBACKGROUND: This paper reports an investigation of the microphase‐separated morphology and phase behaviour in blends of d‐polystyrene‐block‐polyisoprene with homopolystyrene in the weak segregation regime, using small‐angle X‐ray scattering and transmission electron microscopy, as a function of composition, weight‐average molecular weight and temperature. The chain length ratio parameter rM = MH/MC (where MH and MC are the weight‐average molecular weights of the homopolymer and corresponding block copolymer chain) was selected to encompass all possible types of mutual homopolymer/block copolymer sizes.RESULTS: In the weak segregation regime the polystyrene block chains behave as a ‘wet brush’ for rM < 1 similarly to the intermediate and strong segregation regimes. For rM > 1 a macroscopic phase separation occurs. The domain spacing D increases systematically in the range 0 < rM ≤ 1 with increasing concentration of homopolymer wP and increasing rM regardless of the implemented specific morphology, but the slope of the periodicity D versus wP relation is smaller than in the intermediate and strong segregation regimes.CONCLUSION: The criterion for ‘wet and dry brush’ morphologies has been applied to explain the changes in microdomain morphology during the self‐assembly process. It has been shown that the parameters rM and χ3/2N (where χ is the Flory–Huggins parameter and N the number of segments per chain) characterize the slope of the D versus wP relation in the weak and intermediate segregation regimes. Copyright © 2009 Society of Chemical Industry
Monomeric structure of the cardioprotective chemokine SDF‐1/CXCL12
Authors: Veldkamp Christopher T. , Ziarek Joshua J. , Su Jidong , Basnet Harihar , Lennertz Richard , Weiner Joshua J. , Peterson Francis C. , Baker John E. , Volkman Brian F. 
Published: May 2009

AbstractThe chemokine stromal cell‐derived factor‐1 (SDF‐1/CXCL12) directs leukocyte migration, stem cell homing, and cancer metastasis through activation of CXCR4, which is also a coreceptor for T‐tropic HIV‐1. Recently, SDF‐1 was shown to play a protective role after myocardial infarction, and the protein is a candidate for development of new anti‐ischemic compounds. SDF‐1 is monomeric at nanomolar concentrations but binding partners promote self‐association at higher concentrations to form a typical CXC chemokine homodimer. Two NMR structures have been reported for the SDF‐1 monomer, but only one matches the conformation observed in a series of dimeric crystal structures. In the other model, the C‐terminal helix is tilted at an angle incompatible with SDF‐1 dimerization. Using a rat heart explant model for ischemia/reperfusion injury, we found that dimeric SDF‐1 exerts no cardioprotective effect, suggesting that the active species is monomeric. To resolve the discrepancy between existing models, we solved the NMR structure of the SDF‐1 monomer in different solution conditions. Irrespective of pH and buffer composition, the C‐terminal helix remains tilted at an angle with no evidence for the perpendicular arrangement. Furthermore, we find that phospholipid bicelles promote dimerization that necessarily shifts the helix to the perpendicular orientation, yielding dipolar couplings that are incompatible with the NOE distance constraints. We conclude that interactions with the alignment medium biased the previous structure, masking flexibility in the helix position that may be essential for the distinct functional properties of the SDF‐1 monomer.
Solution structure of the phytotoxic protein PcF: The first characterized member of the Phytophthora PcF toxin family
Authors: Nicastro Giuseppe , Orsomando Giuseppe , Ferrari Elena , Manconi Lucia , Desario Filomena , Amici Adolfo , Naso Alessia , Carpaneto Armando , Pertinhez Thelma A. , Ruggieri Silverio , Spisni Alberto 
Published: May 2009

AbstractThe PcF protein from Phytophthora cactorum is the first member of the “PcF toxin family” from the plant pathogens Phytophthora spp. It is able to induce withering in tomato and strawberry leaves. The lack of sequence similarity with other proteins hampers the identification of the molecular mechanisms responsible for its toxicity. Here, we show that the six cysteines form a disulphide pattern that is exclusive for PcF and essential for the protein withering activity. The NMR solution structure identifies a novel fold among protein effectors: a helix‐loop‐helix motif. The presence of a negatively charged surface suggests that it might act as a site of electrostatic interaction. Interestingly, a good fold match with Ole e 6, a plant protein with allergenic activity, highlighted the spatial superimposition of a stretch of identical residues. This finding suggests a possible biological activity based on molecular mimicry.
DNA methylation biomarkers of prostate cancer: Confirmation of candidates and evidence urine is the most sensitive body fluid for non‐invasive detection
Authors: Payne Shannon R. , Serth Jűrgen , Schostak Martin , Kamradt Jőrn , Strauss Arne , Thelen Paul , Model Fabian , Day J. Kevin , Liebenberg Volker , Morotti Andrew , Yamamura Su , Lograsso Joe , Sledziewski Andrew , Semjonow Axel 
Published: May 2009

AbstractBACKGROUNDA prostate cancer (PCa) biomarker with improved specificity relative to PSA is a public health priority. Hypermethylated DNA can be detected in body fluids from PCa patients and may be a useful biomarker, although clinical performance varies between studies. We investigated the performance of candidate PCa DNA methylation biomarkers identified through a genome‐wide search.METHODSReal‐time PCR was used to measure four DNA methylation biomarkers: GSTP1 and three previously unreported candidates associated with the genes RASSF2, HIST1H4K, and TFAP2E in sodium bisulfite‐modified DNA. Matched plasma and urine collected prospectively from 142 patients referred for prostate biopsy and 50 young asymptomatic males were analyzed.RESULTSAnalysis of all biomarkers in urine DNA significantly discriminated PCa from biopsy negative patients. The biomarkers discriminated PCa from biopsy negative patients with AUCs ranging from 0.64 for HIST1H4K (95% CI 0.55–0.72, P < 0.00001) to 0.69 for GSTP1 (95% CI 0.60–0.77, P < 0.00001). All biomarkers showed minimal correlation with PSA. Multivariate analysis did not yield a panel that significantly improved performance over that of single biomarkers. All biomarkers showed greater sensitivity for PCa in urine than in plasma DNA.CONCLUSIONSAnalysis of the biomarkers in urine DNA significantly discriminated PCa from biopsy negative patients. The biomarkers provided information independent of PSA and may warrant inclusion in nomograms for predicting prostate biopsy outcome. The biomarkers' PCa sensitivity was greater for urine than plasma DNA. The biomarker performances in urine DNA should next be validated in formal training and test studies. Prostate 69:1257–1269, 2009. © 2009 Wiley‐Liss, Inc.
Inheritance, fitness cost and mechanism of resistance to tebufenozide in Spodoptera exigua (Hübner) (Lepidoptera: Noctuidae)
Authors: Jia Biantao , Liu Yongjie , Zhu Yu Cheng , Liu Xugan , Gao Congfen , Shen Jinliang 
Published: May 2009

AbstractBACKGROUND: Tebufenozide has been used as a key insecticide for controlling beet armyworm, Spodoptera exigua (Hübner). To evaluate the risk of resistance evolution and to develop a better resistance management strategy, a field‐collected population was selected with tebufenozide in the laboratory. Thereafter, the inheritance and fitness cost of tebufenozide resistance in S. exigua were investigated.RESULTS: After being selected with tebufenozide for 61 generations, S. exigua developed a 92‐fold resistance to the chemical. The degrees of dominance for the reciprocal cross progeny were − 0.2698 and − 0.2785. The resistant strain had a relative fitness of 0.71, with substantially lower rates of larval survival, pupal weight, pupation and oviposition per female, and prolonged larval and pupal duration. PBO significantly increased the toxicity of tebufenozide (SR = 2) against resistant insects, and DEM and DEF also showed synergism with tebufenozide.CONCLUSION: Tebufenozide resistance in S. exigua was inherited as autosomal, incompletely recessive and controlled by more than one gene. Development of the resistance may cost significant fitness for the resistant population. Mixed‐function oxidases might play an important role in tebufenozide resistance in S. exigua. This study provided valuable information for further understanding tebufenozide resistance and for facilitating the development of resistance management strategies. Copyright © 2009 Society of Chemical Industry
Diffusion of platinum adatoms and dimers on Pt(111) surface by molecular‐dynamics simulation
Authors: Panagiotides Nicolas , Papanicolaou Nicolas I. 
Published: May 2009

AbstractWe present an interatomic potential for Pt within the second‐moment approximation of the tight‐binding theory. The potential was obtained by fitting to the total energy of the metal, computed by first‐principles augmented‐plane‐wave calculations as a function of the volume. This was used, in tandem with molecular‐dynamics simulations, to study the diffusion of Pt adatoms and dimers on Pt(111) surface. The diffusion coefficient of the adatoms and dimers was computed and was found to present Arrhenius behavior. The migration energies and preexponential factors for hopping diffusion mechanism were determined as well and compared with experimental data obtained by scanning tunnelling microscopy and field ion microscopy methods. Both quantities were found to be in good agreement with measurements. Moreover, a concerted adatom exchange diffusion mechanism was investigated at high temperatures, where there is an involvement of more than one surface atom. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2010
Performance analysis of APSK modulation for DVB‐S2 transmission over nonlinear channels
Authors: Sung Wonjin , Kang Seokheon , Kim Pansoo , Chang Dae‐Ig , Shin Dong‐Joon 
Published: May 2009

AbstractFor increased bandwidth efficiency and receiver performance, standards for satellite broadcasting systems are evolving by utilizing efficient transmission techniques. The second‐generation digital video broadcasting for satellites (DVB‐S2) adopts the amplitude phase shift keying (APSK) modulation for enhanced performance over nonlinear channels. In this paper, we derive error rate bounds for APSK modulated symbols and generalize the bounds to the case of distorted constellation, which occurs when the maximum transmission amplitude is saturated by the soft‐limiter type channel. The derived bound is shown to significantly improve the previously known result, to accurately predict both the symbol error rate and bit error rate in the entire signal‐to‐noise ratio (SNR) region of interest. Using the derived formula, the optimal input power level for the soft‐limiter channel is determined, and the corresponding minimal error rates for 16‐ and 32‐APSK are quantified. The result is also interpreted in terms of optimal input back‐off (IBO) for nonlinear power amplifiers by evaluating the performance degradation as a function of IBO. Copyright © 2009 John Wiley & Sons, Ltd.
Numerical variations and spontaneous malformations in the early embryos of the Korean salamander, Hynobius leechii, in the farmlands of Korea
Authors: Park Yong‐Uk , Yoon Chun‐Sik , Kim Jong‐Hyang , Park Joo‐Hung , Cheong Seon‐Woo 
Published: May 2009

AbstractEmbryo sacs of the Korean salamander, Hynobius leechii, were collected from nine farmlands in Gyeongsangnam‐Do, Korea, in early spring of 2002 and 2004. The variations in the number of embryos within each embryo sac and the mortality and abnormality rates among the embryos were investigated. We also analyzed the patterns of spontaneous embryonic malformations and the residual chemicals in the soil of the habitats using multiple‐residue GC/MS. A total of 79,195 embryos were obtained from 1933 embryo sacs. There were regional variations in the length of individual embryo sacs and the number of embryos in each. The longest embryo sac averaged by region measured 20.67 (cm) ± 3.51 and was obtained from 2‐Banseong in 2002. Of the embryos collected, 13.71% either died or stopped developing, and 3.54% of the hatched embryos developed abnormally; the latter were classified according to the patterns of malformation. External gill dysplasia was the most frequent malformation, and caudal dysplasia, abdominal blisters, and dysplasia of the fin were also observed frequently. Histopathological analysis showed neural tube abnormalities, acrania, curved notochords, thyroid teratoma, and various other kinds of endodermal developmental abnormalities. In the analysis of the residual pesticides in the soil, carbofuran, endosulfan‐sulfate, and endosulfan‐β were detected in the regions with high mortality and malformation rates. These results indicate that various agricultural chemicals and other unknown factors may cause the aforementioned forms of spontaneous malformations in the embryos of Hynobius leechii. © 2009 Wiley Periodicals, Inc. Environ Toxicol 25: 533–544, 2010.
PIXE analysis of a painting by Giorgio Vasari
Authors: Grassi N. , Bonanni P. , Mazzotta C. , Migliori A. , Mandò P. A. 
Published: May 2009

AbstractAmong ion beam analysis (IBA) techniques, particle induced x‐ray emission (PIXE) is the most widely used in the field of cultural heritage, providing the elemental composition of materials in a non‐invasive and non‐destructive way. This paper reports on the analysis by PIXE performed at one of the external beamlines of the 3 MV Tandetron accelerator of the LABEC laboratory (Istituto Nazionale di Fisica Nucleare (INFN)—Florence) on a wood painting by Giorgio Vasari, belonging to the altar‐piece ‘Pala Albergotti’ (church of Sts Flora and Lucilla, Arezzo). The measurements were taken in the framework of a campaign of scientific investigations, promoted by the Soprintendenza of Arezzo, preliminary to the restoration of the whole altar‐piece. PIXE was used to identify the elemental composition of the original materials and to characterise the alteration layer visible on the surface of the painting. Measurements on the same spot with proton beams of different energies (differential PIXE) also allowed us to get information on the depth distribution of elements and on the structure of layers without the need of picking up samples. Copyright © 2009 John Wiley & Sons, Ltd.
The Effectiveness of Family History Questionnaires in Cancer Genetic Counseling
Authors: Randall Armel Susan , McCuaig Jeanna , Finch Amy , Demsky Rochelle , Panzarella Tony , Murphy Joan , Rosen Barry 
Published: May 2009

AbstractThe number of individuals receiving genetic counseling for hereditary breast and ovarian cancer syndrome has steadily risen. To triage patients for genetic counseling and to help reduce the amount of time needed by a genetic counselor in direct patient contact, many clinics have implemented the use of family history questionnaires. Although such questionnaires are widely used, scant literature exists evaluating their effectiveness. This article explores the extent to which family history questionnaires are being used in Ontario and addresses the utility of such questionnaires in one familial cancer clinic. By comparing the pedigrees created from questionnaires to those updated during genetic counseling, the accuracy and effectiveness of the questionnaires was explored. Of 121 families recruited into the study, 12% acquired changes to their pedigree that led to a revised probability estimate for having a BRCA1 or BRCA2 mutation and 5% acquired changes that altered their eligibility for genetic testing. No statistically significant difference existed between the eligibility for genetic testing prior to and post counseling. This suggests that family history questionnaires can be effective at obtaining a family history and accurately assessing eligibility for genetic testing. Based on the variables that were significantly associated with a change in probability estimate, we further present recommendations for improving the clarity of such questionnaires and therefore the ease of use by patients.
Preparation and Characterization of Cationic PLA-PEG Nanoparticles for Delivery of Plasmid DNA
Authors: Zou Weiwei , Liu Chunxi , Chen Zhijin , Zhang Na 
Published: May 2009

Abstract
The purpose of the present work was to formulate and evaluate cationic poly(lactic acid)-poly(ethylene glycol) (PLA-PEG) nanoparticles as novel non-viral gene delivery nano-device. Cationic PLA-PEG nanoparticles were prepared by nanoprecipitation method. The gene loaded nanoparticles were obtained by incubating the report gene pEGFP with cationic PLA-PEG nanoparticles. The physicochemical properties (e.g., morphology, particle size, surface charge, DNA binding efficiency) and biological properties (e.g., integrity of the released DNA, protection from nuclease degradation, plasma stability, in vitro cytotoxicity, and in vitro transfection ability in Hela cells) of the gene loaded PLA-PEG nanoparticles were evaluated, respectively. The obtained cationic PLA-PEG nanoparticles and gene loaded nanoparticles were both spherical in shape with average particle size of 89.7 and 128.9 nm, polydispersity index of 0.185 and 0.161, zeta potentials of +28.9 and +16.8 mV, respectively. The obtained cationic PLA-PEG nanoparticles with high binding efficiency (>95%) could protect the loaded DNA from the degradation by nuclease and plasma. The nanoparticles displayed sustained-release properties in vitro and the released DNA maintained its structural and functional integrity. It also showed lower cytotoxicity than Lipofectamine 2000 and could successfully transfect gene into Hela cells even in presence of serum. It could be concluded that the established gene loaded cationic PLA-PEG nanoparticles with excellent properties were promising non-viral nano-device, which had potential to make cancer gene therapy achievable.
Last glacial climate instability documented by coarse-grained sediments within the loess sequence, at Fanjiaping, Lanzhou, China
Authors: Jiang Hanchao , Wang Ping , Thompson Jessica , Ding Zhongli , Lu Yanchou 
Published: May 2009

AbstractOptically Stimulated Luminescence dating, grain-size analysis and magnetic susceptibility measurements were conducted on the Fanjiaping loess section, from the western Chinese Loess Plateau. The results confirm that last glacial high-frequency climatic shifts were documented in mid-latitude continental archives. The grain-size record indicated that coarse-grained sediments with horizontal bedding and channel-fill structures were only deposited in several short intervals, equivalent to the beginning of marine oxygen isotope stage (MIS) 4 and the early to middle MIS 3. This probably implies brief rainfall intensification of the Asian summer monsoon, and its disappearance since the late MIS 3 to MIS 2 may have been a response to significant glacial cooling in the Northern Hemisphere. Previous investigations revealed high sea-surface temperatures at high latitudes at the start of MIS 4, and the early to middle MIS 3 intensification of summer insolation in the Northern Hemisphere, implying evident climate amelioration. Climate improvement favors boreal forest recovery, enhancing both winter and summer air temperatures. The resultant smaller equator-polar temperature gradient probably helped the moisture-laden summer monsoon to penetrate northward. This study thus provides new significant information about the response of terrestrial loessic palaeoenvironments to millennial-timescale climatic fluctuations during the last glacial period.
Influence of coexisting myringosclerosis on myringoplasty outcomes in children
Authors: Migirov L , Volkov A 
Published: May 2009

AbstractObjective:To obtain information on the success rate of tympanoplasty with concomitant myringosclerosis.Methods:The medical records of 40 children with myringosclerosis (23 girls, 17 boys; age range six to 16 years, mean age 9.85 years) who had undergone primary tympanoplasty were retrospectively studied. Surgical success was defined as the perforation remaining closed 12 months post-operatively.Results:Sclerotic plaques occupied whole remnant eardrums in 17 patients, and were located in various parts of the eardrum in 23. Tympanosclerosis associated with myringosclerosis was present in six patients. The success rate of primary tympanoplasty was 92.5 per cent. All three surgical failures were observed in girls with marginal perforations. These children underwent successful revision procedures for their residual perforations, variously at four, eight and 10 months after the initial surgery.Conclusion:Appropriate freshening of the perforation edges, with removal of sclerotic plaques, can result in a high rate of successful closure of perforated tympanic membrane with coexisting myringosclerosis.
Wildlife disease and conservation in Hawaii: Pathogenicity of avian malaria (Plasmodium relictum) in experimentally infected Iiwi (Vestiaria coccinea)
Authors: Atkinson C. T. , Woods K. L. , Dusek R. J. , Sileo L. S. , Iko W. M. 
Published: May 2009

SUMMARYNative Hawaiian forest birds are facing a major extinction crisis with more than 75% of species recorded in historical times either extinct or endangered. Reasons for this catastrophe include habitat destruction, competition with non-native species, and introduction of predators and avian diseases. We tested susceptibility of Iiwi (Vestiaria coccinea), a declining native species, and Nutmeg Mannikins (Lonchura punctulata), a common non-native species, to an isolate ofPlasmodium relictumfrom the island of Hawaii. Food consumption, weight, and parasitaemia were monitored in juvenile Iiwi that were infected by either single (low-dose) or multiple (high-dose) mosquito bites. Mortality in both groups was significantly higher than in uninfected controls, reaching 100% of high-dose birds and 90% of low-dose birds. Significant declines in food consumption and a corresponding loss of body weight occurred in malaria-infected birds. Both sex and body weight had significant effects on survival time, with males more susceptible than females and birds with low initial weights more susceptible than those with higher initial weights. Gross and microscopic lesions in malaria fatalities included massive enlargement of the spleen and liver, hyperplasia of the reticuloendothelial system with extensive deposition of malarial pigment, and overwhelming anaemia in which over 30% of the circulating erythrocytes were parasitized. Nutmeg Mannikins, by contrast, were completely refractory to infection. Our findings support previous studies documenting high susceptibility of native Hawaiian forest birds to avian malaria. This disease continues to threaten remaining high elevation populations of endangered native birds.