bluuebunny/crossref_metadata_2025_split huggingface dataset:
Formation of Ethyl 1‐Thiomannopyranosides from 2‐O‐Chloroacetylated and 2‐O‐Levulinoylated Synthons
Authors: Adamo Roberto , Kováč Pavol 
Published: April 2006

AbstractWith the aim to prepare key glycosyl donors for the synthesis of fragments of the O‐specific polysaccharides of Vibrio cholerae O:1, 1‐O‐acetyl derivatives of perosamine bearing participating 2‐O‐chloroacetyl or 2‐O‐levulinoyl groups were treated with EtSH and BF3·Et2O. While poor stereoselectivity of the formation of ethyl 1‐thioglycosides (α:β = 3:2) was observed with 2‐O‐chloroacetylated intermediates, the same products can be obtained with good stereoselectivity (α:β = 7:1) from 2‐O‐levulinoylated intermediates. Selective regeneration of the carbonyl group from dithioketals in the presence of S,O‐acetals by treatment with AgNO3 and Ag2O in MeCN/H2O is also described. The conversion allows direct preparation of 1‐thioglycosides from carbohydrates protected with the levulinic ester group. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Optimal two‐stage genotyping designs for genome‐wide association scans
Authors: Wang Hansong , Thomas Duncan C. , Pe'er Itsik , Stram Daniel O. 
Published: April 2006

AbstractThe much‐anticipated fixed‐array, genome‐wide SNP genotyping technologies make large‐scale genome‐wide association scans now possible for large numbers of subjects. In this paper we reconsider the problem (Satagopan and Elston [2003] Genet Epidemiol 25:149–157) of optimizing a two‐stage genotyping design to deal with important new issues that are relevant when studies are expanded from candidate gene size to a genome‐wide scale. We investigate how the basic two‐stage genotyping approach, in which all markers are genotyped in an initial group of subjects (stage I) and only the promising markers are genotyped in additional subjects (stage II), can be used to reduce genotyping cost in a genome‐wide case‐control association study even after allowing for much higher per genotype costs using specially designed assays in stage II, compared to the fixed array of SNPs used in stage I. In addition, we consider the problem of using measured SNPs to make (imperfect) prediction of unmeasured SNPs for association tests of all SNPs (measured or unmeasured) genome wide and the utility of expanding genotyping densities in stage II in the regions where significant associations were detected in stage I. Under a set of reasonable but conservative assumptions, we derive optimal two‐stage design configurations (sample sizes and the thresholds of significance in both stages) with these optimal designs depending both on the total number of markers tested and upon the ratios of cost in stage II versus stage I. In addition we show how existing software for power and sample size calculations can be used for the purpose of designing two‐stage studies, for a wide range of assumptions about the number of markers genotyped and the costs of genotyping in each stage of the study. Genet. Epidemiol. 2006. © 2006 Wiley‐Liss, Inc.
Improved survival and chemotherapy response among patients with AIDS‐related non‐Hodgkin's lymphoma receiving highly active antiretroviral therapy
Authors: Diamond Catherine , Taylor Thomas H , Im Theresa , Miradi Mohammed , Anton‐Culver Hoda 
Published: April 2006

AbstractHighly active antiretroviral therapy (HAART) became available in the US in 1996. Using the population‐based cancer registry, we identified 233 patients with AIDS‐related systemic NHL diagnosed in San Diego or Orange County in 1994–1999, of whom 137 were diagnosed 1996–1999. We performed Kaplan‐Meier analyses to compare survival between patients who received HAART at NHL diagnosis or thereafter versus untreated patients and Cox proportional hazard models for adjusted survival. We used logistic regression to determine if concomitant HAART changed the probability of complete response to chemotherapy and the Mann–Whitney U‐test to compare the median number of chemotherapy cycles between patients who received HAART during chemotherapy versus those who did not. Among patients diagnosed with NHL in 1996–1999, 40 (29%) were taking HAART at NHL diagnosis. The median survival was three months among patients who did not receive HAART versus 16 months among HAART‐treated patients. HAART, chemotherapy, high performance status, and NHL stage < IV were associated with improved survival. Concomitant HAART, completion of ≥ 6 chemotherapy cycles, and NHL stage < IV were associated with complete response to chemotherapy. The median number of chemotherapy cycles was five among patients who received HAART concomitant with chemotherapy versus three among untreated patients. We conclude that HAART should be initiated or continued after NHL diagnosis, including during the period of chemotherapy administration. Copyright © 2006 John Wiley & Sons, Ltd.
The ultrastructure of MCF‐10A acini
Authors: Underwood Jean M. , Imbalzano Karen M. , Weaver Valerie M. , Fischer Andrew H. , Imbalzano Anthony N. , Nickerson Jeffrey A. 
Published: April 2006

AbstractMCF‐10A human mammary epithelial cells cultured inside reconstituted basement membrane form acini that resemble the acinar structures of mammary lobules. This three‐dimensional culture system has been used for identifying and characterizing the signal transduction pathways controlling cell proliferation and death, and for studying their disregulation in malignant progression. We have compared the ultrastructure of MCF‐10A acini, MCF‐10A cells grown in monolayer, and the acinar structures of human breast lobules. The tissue architecture of MCF‐10A acini was formed by hemidesmosomes connected to a basement membrane and by abundant desmosomes between acinar cells. Intermediate filaments that joined into large and abundant filament bundles connected hemidesmosomes and desmosomes to sites at the nuclear surface. Fewer and thinner bundles of filaments were observed in monolayer MCF‐10A cells and even fewer in breast tissue. Tight junctions were observed between cells in breast tissue but missing in MCF‐10A acini. The cytoplasm of MCF‐10A acinar cells had a polar organization similar to that observed in breast tissue, with centrosomes and the Golgi apparatus on the apical side of the nucleus. MCF‐10A acinar nuclei had an irregular, frequently invaginated surface and had a single nucleolus. The distribution of heterochromatin was similar to that in the epithelial cells of breast tissue. The nuclei of monolayer MCF‐10A cells had multiple nucleoli, a more regular profile, and less heterochromatin. Electron microscopy has the resolution required to survey features of MCF‐10A cell and acinus architecture that may change with manipulations designed to induce malignant phenotypes. J. Cell. Physiol. © 2006 Wiley‐Liss, Inc.
Aid, social policies and pro‐poor growth
Authors: Verschoor Arjan , Kalwij Adriaan 
Published: April 2006

AbstractRecent literature reports that foreign aid contributes to economic growth when economic policies are good. This paper claims that aid can contribute not just to growth but also to pro‐poor growth, through increasing the responsiveness of social indicators to economic growth. The empirical evidence we present is in favour of this claim, suggesting that both aid itself and a recipient government's budget share allocated to social services tend to increase the (absolute) size of the income elasticity of poverty and infant mortality, and that, moreover, aid tends to increase this budget share. Copyright © 2006 John Wiley & Sons, Ltd.
Radical cation formation in characterization of novel C3‐symmetric disks and their precursors by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry
Authors: Lou Xianwen , van den Hout Kelly P. , van Houtem Michel H. C. J. , van Dongen Joost L. J. , Vekemans Jef A. J. M. , Meijer E. W. 
Published: April 2006

AbstractFour C3‐symmetrical tris(dipeptide) disks and their precursors were characterized using matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI TOF MS). The C3‐symmetrical disks were based on a benzene‐1,3,5‐triscarboxamide core extended by oligopeptides with trialkoxyanilide tails. The results indicate that MALDI TOF MS is a powerful and straightforward analytical technique for characterizing C3‐symmetrical disks and their precursors. Clear (pseudo)‐molecular ion peaks could readily be identified. It is remarkable that strong radical ion signals were observed for all the compounds, including the anilines that were expected to be protonated prior to laser irradiation using acidic MALDI matrixes. Possible mechanisms for radical ion formation were investigated with the employment of radical scavengers, with various matrixes and with direct laser desorption/ionization (LDI). Most likely the radicals are formed by losing one electron from the aniline nitrogen and stabilized by conjugation through the phenyl ring. It appears that direct photo/thermal ionization of analytes is an important route for the radical ion formation of the compounds with trialkoxy aniline/anilide groups. Copyright © 2006 John Wiley & Sons, Ltd.
Immuno‐Raman microspectroscopy: In situ detection of antigens in tissue specimens by surface‐enhanced Raman scattering
Authors: Schlücker S. , Küstner B. , Punge A. , Bonfig R. , Marx A. , Ströbel P. 
Published: April 2006

AbstractWe demonstrate the first realization of immuno‐Raman microspectroscopy, a novel methodology in immunohistochemistry. The in situ detection of antigens in tissue specimens is achieved by surface‐enhanced Raman scattering (SERS) from aromatic Raman labels covalently linked to the corresponding antibody. As an example of applications of this new Raman technique, we present the localization of prostate‐specific antigen (PSA) in epithelial tissue from patients with prostate carcinoma (PCA). Copyright © 2006 John Wiley & Sons, Ltd.
Effect of germination and dehulling on functional properties of legume flours
Authors: Ghavidel Reihaneh Ahmadzadeh , Prakash Jamuna 
Published: April 2006

AbstractThe functional properties of flours derived from selected legumes were studied before and after dehulling of the germinated seeds. Ungerminated seeds were used as the control. The chosen legumes were green gram (Phaseolus aureus), cowpea (Vigna catjang), lentil (Lens culinaris) and bengal gram (Cicer arietinum). Dehulled samples had a higher protein solubility compared with germinated and control samples. The bulk densities of germinated and dehulled legume flours were lower compared to control. Germination increased water absorption capacities of legume flours from 1226, 1285, 974 and 1362 g kg−1 to 1481, 1433, 1448 and 1517 g kg−1 in green gram, cowpea, lentil and bengal gram, respectively. Fat absorption capacities increased in germinated samples (1130, 1242, 920 and 837 g kg−1) as against 900, 993, 857 and 788 g kg−1 at ambient conditions for green gram, cowpea, lentil and bengal gram, respectively. On dehulling, the fat absorption capacities of samples were reduced and the differences were statistically significant. The emulsification capacities of control samples ranged from 55 to 193 ml oil emulsified per gram of sample. On germination and dehulling, the emulsification capacities, activities and stabilities of samples increased significantly. There were increases in foaming capacities and reduction in foam stabilities of all the samples investigated on germination and dehulling. Thus, the study indicated that germination and dehulling improved the functional properties of legumes. Copyright © 2006 Society of Chemical Industry
Supplementing fresh pasture with maize, lotus, sulla and pasture silages for dairy cows in summer
Authors: Woodward Sharon L , Chaves Alexandre V , Waghorn Garry C , Brookes Ian M , Burke Jennifer L 
Published: April 2006

AbstractA trial was conducted to compare benefits obtained from feeding four types of silage. There were two silages that contained condensed tannins (CT)—lotus (Lotus corniculatus) and sulla (Hedysarum coronarium)—maize silage or traditional ryegrass pasture silage, all fed at 5 kg dry matter (DM) cow−1 day−1 with restricted pasture (RP). Cows on the RP (control) treatment and those fed the silage treatments were offered an allowance of 25 kg pasture DM cow−1 day−1, while the full pasture (FP) cows were offered 50 kg pasture DM cow−1 day−1. Silage supplementation increased both DM intake and milk yield compared with cows given RP only. Cows on the lotus silage supplement and the FP treatment had significantly higher milk production than the other silage supplemented cows (P < 0.001). For cows given lotus silage, the high milk yield was probably due to a combination of the higher nutritive value of the silage and possibly to the protein‐sparing effects of the lotus condensed tannins because the total DM intake of cows fed the lotus silage was the same as that of cows given the pasture and maize silages (P > 0.25). The high milk yield of the FP treatment was mainly a result of the cows having a higher intake of pasture than cows on all the other treatments. This study demonstrated the potential benefit of silage supplementation, particularly with lotus silage, for increased milksolids yield in summer when low pasture growth rates and quality may otherwise limit production. Copyright © 2006 Society of Chemical Industry
Immunoaffinity carrier prepared by immobilization of antibody via Co3+‐chelate
Authors: Zatloukalová Eva , Kucerová Zdenka 
Published: April 2006

AbstractA method for the immobilization of antibodies to inert matrix represents an important factor that affects results of immunoaffinity chromatography. Binding antibodies to immobilized metal ions is an example of oriented immobilization that avoids a random coupling of a protein. Preparation of a stable immunoaffinity sorbent using immobilized metal ions was described. Antibodies were bound to chelated Co3+ ions that were prepared by oxidation of Co2+‐iminodiacetic acid agarose using hydrogen peroxide. The formation of a stable complex of the antibody with immobilized Co3+ ions was proved. Antibodies bound by this way were not released with solutions of 50 mM EDTA, 6 M urea, 3 M NaCl, 20% v/v dioxane, 0.1 M imidazole and buffers of pH 2.5 and pH 11.0. If needed, antibody could be released from the carrier by the reduction of Co3+ ions with a reducing agent (e. g. dithiotreitol or 2‐mercaptoethanol). Antibody released from the carrier could be then replaced by another antibody. The method described in this paper was used for the immobilization of polyclonal rabbit anti‐ovalbumin antibody or egg yolk antibody (IgY) produced in chicken. In a model experiment, immobilized polyclonal rabbit antibodies were used for the separation of ovalbumin from egg white and conditions of chromatography were described.
Synthesis and Characterization of a Novel Degradable Aliphatic Polyester that Contains Monomeric Lactate Sequences
Authors: Xiao Congming , He Yueying , Jin Hongmei 
Published: April 2006

AbstractSummary: A novel degradable aliphatic polyester that contains monomeric lactate sequences is synthesized via melt‐polycondensation of ethylene glycol lactate diol (EGLD) with succinic anhydride without the use of catalyst. The structure of the EGLD precursor and the polyester are verified with FT‐IR and 1H NMR spectra. Gel permeation chromatography reveals that the weight‐average molecular weight of the polyester is 5.5 × 104 with a polydispersity index (PDI) of 1.7. Differential scanning calorimetry profiles reveal that the polyester is a semicrystalline polymer with a glass transition temperature of −12 °C and melting temperature of 101 °C. The weight loss percentage of the polyester after immersing for 208 d in active sludge is 2.7%, which suggests degradation has occurred.The synthesis route of the polyester synthesized here (see inset for structure).magnified imageThe synthesis route of the polyester synthesized here (see inset for structure).
Macromonomer Purification Strategy for Well‐Defined Polymer Amphiphiles Incorporating Poly(ethylene glycol) Monomethacrylate
Authors: Taniguchi Ikuo , Kuhlman William A. , Griffith Linda G. , Mayes Anne M. 
Published: April 2006

AbstractSummary: Commercial hydroxy‐terminated poly(ethylene glycol) monomethacrylates (PEG‐MAs) contain poly(ethylene glycol) dimethacrylate, which leads to unfavorable gel formation on polymerization. Here, hydroxy‐terminated PEG‐MA is readily isolated using a dimethylsilyl resin chlorinated with 1,3‐dichloro‐5,5‐dimethylhydantoin. Solution polymerization of the isolated PEG‐MA by free radical routes gives a high‐molecular‐weight amphiphilic graft copolymer without cross‐linking. The resulting polymer is stable for long periods in ambient conditions with preservation of the hydroxy end groups of PEG.Commercial hydroxy‐terminated PEG‐MA can be separated readily and completely from PEG dimethacrylate contaminant with chlorinated dimethylsilyl resin.magnified imageCommercial hydroxy‐terminated PEG‐MA can be separated readily and completely from PEG dimethacrylate contaminant with chlorinated dimethylsilyl resin.
Synthesis of Conjugated Polymer Nanoparticles in Non‐Aqueous Emulsions
Authors: Müller Kevin , Klapper Markus , Müllen Klaus 
Published: April 2006

AbstractSummary: A novel non‐aqueous emulsion system, consisting of cyclohexane as the continuous and acetonitrile as the dispersed phase, is described. Stabilization of the system can be achieved by using polyisoprene‐block‐poly(methyl methacrylate) copolymers as emulsifiers. The suitability of this system for performing water‐sensitive, catalytic, and oxidative polymerizations and polycondensations is demonstrated by the synthesis of poly(3,4‐ethylenedioxythiophene), poly(thiophene‐3‐yl‐acetic acid), and polyacetylene. In all cases spherical nanoparticles with diameters as small as 23 nm can be obtained.
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Film Growth and Surface Roughness with Effective Fluctuating Covalent Bonds in Evaporating Aqueous Solution of Reactive Hydrophobic and Polar Groups: A Computer Simulation Model
Authors: Yang Shihai , Seyfarth Adam , Bateman Samuel P. , Pandey Ras B. 
Published: April 2006

AbstractSummary: A computer simulation model is proposed to study film growth and surface roughness in aqueous (A) solution of hydrophobic (H) and hydrophilic (P) groups on a simple three dimensional lattice of size $L_x \times L_y \times L_z$ with an adsorbing substrate. Each group is represented by a particle with appropriate characteristics occupying a unit cube (i.e., eight sites). The Metropolis algorithm is used to move each particle stochastically. The aqueous constituents are allowed to evaporate while the concentration of H and P is constant. Reactions proceed from the substrate and bonded particles can hop within a fluctuating bond length. The film thickness ($h$) and its interface width ($W$) are examined for hardcore and interacting particles for a range of temperature ($T$). Simulation data show a rapid increase in $h$ and $W$ followed by its non‐monotonic growth and decay before reaching steady‐state and near equilibrium ($h_{\rm s}, W_{\rm s}$) in asymptotic time step limit. The growth can be described by power laws, e.g., $h \propto t^{\gamma}, W \propto t^{\beta}$ with a typical value of $\gamma \approx 2, \beta \approx 1$ in initial time regime followed by $\gamma \approx 1.5, \beta \approx 0.8$ at $T = 0.5$. For hardcore system, the equilibrium film thickness ($h_{\rm s}$) and surface roughness ($w_{\rm s}$) seem to scale linearly with the temperature, i.e., $h_{\rm s} = 6.206 + 0.302 T, W_{\rm s} = 1\,255 + 0.425 T$ at low $T$ and $h_{\rm s} = 6.54 + 0.198 T, W_{\rm s} = 1.808 + 0.202 T$ at higher $T$. For interacting functional groups in contrast, the long time (unsaturated) film thickness and surface roughness, $h_{\rm s}$ and $W_{\rm s}$ decay rapidly followed by a slow increase on raising the temperature.Growth of the average film thickness at a temperature $T=5$.magnified imageGrowth of the average film thickness at a temperature $T=5$.
Mathematical Modeling of Atom‐Transfer Radical Polymerization Using Bifunctional Initiators
Authors: Al‐Harthi Mamdouh , Soares João B. P. , Simon Leonardo C. 
Published: April 2006

AbstractSummary: Bifunctional initiators can produce polymers with higher molecular weight at higher initiator concentrations than monofunctional initiators. In this study, we developed a mathematical model for ATRP with bifunctional initiators. The most important reactions in ATRP were included in the model. The method of moments was used to predict monomer conversion, average molecular weights and polydispersity index as a function of polymerization time in batch reactors. The model was used to understand the mechanism of ATRP and to quantify how polymerization conditions affect monomer conversion and polymer properties by examining the effect of several rate constants (activation, deactivation, propagation and chain termination) and of catalyst and initiator concentration on polymerization kinetics and polymer properties. When compared to monofunctional initiators, bifunctional initiators not only produce polymers with higher molecular weight averages at higher polymerization rates, but also control their molecular weight distributions more effectively.Effect of initial catalyst concentration on polydispersity index as a function of time.magnified imageEffect of initial catalyst concentration on polydispersity index as a function of time.
Correlations and Fluctuations of Charged Colloids as Determined by Anomalous Small‐Angle X‐Ray Scattering
Authors: Jusufi Arben , Ballauff Matthias 
Published: April 2006

AbstractSummary: We performed molecular dynamics simulation of a charged colloidal particle with explicit counterions. Our work provides a direct comparison between simulations and ASAXS‐experiments, offering insight into the counterion distribution of charged colloidal suspensions. We give a detailed constitution of the appearing scattering terms with their physical meaning. It is shown that the cross‐correlation between a macroion and its counterions gives the meanfield approximation of the counterion density even if the counterion system is highly fluctuating. Furthermore, it is shown that cross‐correlations can be negative due to oscillations of the density amplitudes of the macroion and counterions and, therefore, must be distinguished from other scattering contributions. These oscillations become more pronounced if the counterions exhibit a fixed shape and if the size of the macroion and that of the counterion system are different.Simulation sanpshot of a charged colloid (big central sphere) with counterions (small spheres).magnified imageSimulation sanpshot of a charged colloid (big central sphere) with counterions (small spheres).
An absolute approximation algorithm for scheduling unrelated machines
Authors: Shchepin Evgeny , Vakhania Nodari 
Published: April 2006

AbstractNon‐preemptive scheduling of n independent jobs on m unrelated machines so as to minimize the maximal job completion time is considered. A polynomial algorithm with the worst‐case absolute error of min{(1 − 1/m)pmax, p} is presented, where pmax is the largest job processing time and p is the mth element from the non‐increasing list of job processing times. This is better than the earlier known best absolute error of pmax. The algorithm is based on the rounding of acyclic multiprocessor distributions. An O(nm2) algorithm for the construction of an acyclic multiprocessor distribution is also presented. © 2006 Wiley Periodicals, Inc. Naval Research Logistics, 2006