bluuebunny/crossref_metadata_2025_split huggingface dataset:
Structural characterization and identification of C19‐ and C20‐diterpenoid alkaloids in roots of Aconitum carmichaeli by rapid‐resolution liquid chromatography coupled with time‐of‐flight mass spectrometry
Authors: Hu Rong , Zhao Jing , Qi Lian‐Wen , Li Ping , Jing Shan‐Lin , Li Hui‐Jun 
Published: April 2009

AbstractAconite alkaloids from the roots of Aconitum carmichaeli (Fuzi, in Chinese) have been investigated by rapid‐resolution liquid chromatography coupled with time‐of‐flight mass spectrometry (TOFMS) in positive mode. With dynamic adjustment of the key role as fragmentor voltage in TOFMS, an efficient transmission of the ions was achieved to obtain the best sensitivity for providing the molecular formula for each analyte, and abundant fragment ions for structural information. Fifteen authentic standards isolated from Fuzi with various structures were first characterized by TOFMS, including diester‐diterpenoid alkaloids (DDAs), monoester‐diterpenoid alkaloids (MDAs), alkylol amine‐diterpenoid alkaloids (ADAs), veatchine‐type alkaloids and atisine‐type alkaloids. Fragmentation rules and key diagnostic fragment ions have been summarized, and possible pathways of fragmentation have been proposed. By accurate mass measurements within 5 ppm error for each ion, 30 C19‐diterpenoid alkaloids including 10 DDAs, 3 MDAs, 9 ADAs and 8 other type alkaloids, and 8 C20‐diterpenoid alkaloids including 4 veatchine‐type alkaloids and 4 atisine‐type alkaloids could be identified in a methanolic extract of Fuzi. Some isomers of aconite alkaloids were also differentiated. Based on the differences between their fragmentation pathways and special fragment ions, each type of aconite alkaloids was differentiated. Copyright © 2009 John Wiley & Sons, Ltd.
Glycerophospholipid profiling by high‐performance liquid chromatography/mass spectrometry using exact mass measurements and multi‐stage mass spectrometric fragmentation experiments in parallel
Authors: Hein Eva‐Maria , Blank Lars M. , Heyland Jan , Baumbach Jörg I. , Schmid Andreas , Hayen Heiko 
Published: April 2009

AbstractA profiling method for glycerophospholipids (GPs) in biological samples was developed using reversed‐phase high‐performance liquid chromatography (RP‐HPLC) coupled to hybrid linear ion trap‐Fourier transform ion cyclotron resonance mass spectrometry (LIT‐FTICRMS) with electrospray ionization (ESI) in the negative ionization mode. The method allowed qualitative (identification and structure elucidation) and relative quantitative determination of various classes of GPs including phosphatidylcholines, phosphatidylethanolamines, phosphatidylinositols, phosphatidylserines, phosphatidic acids, phosphatidylglycerols, and cardiolipins in a single experiment. Chromatographic separation was optimized by the examination of different buffer systems and special emphasis was paid on the detection by ESI‐MS. The hybrid LIT‐FTICRMS system was operated in the data‐dependent mode, switching automatically between FTICRMS survey scans and LIT‐MS/MS experiments. Thereby, exact masses for elemental composition determination and fragmentation data for identification and assignment of fatty acid residues are provided at the same time. The low absolute instrumental limits of detection (0.05 pmol for phosphatidylglycerol to 1 pmol for phosphatidic acid) complemented by a linear dynamic range of 1.5 to 2.5 orders of magnitude facilitated the relative quantification of GP species in a lipid extract from Saccharomyces cerevisiae. The developed method is a valuable tool for in‐depth GP profiling of biological systems. Copyright © 2009 John Wiley & Sons, Ltd.
Surface Modification of Electrospun Polycaprolactone Nanofiber Meshes by Plasma Treatment to Enhance Biological Performance
Authors: Martins Albino , Pinho Elisabete D. , Faria Susana , Pashkuleva Iva , Marques Alexandra P. , Reis Rui L. , Neves Nuno M. 
Published: April 2009

AbstractA critical aspect in the development of biomaterials is the optimization of their surface properties to achieve an adequate cell response. In the present work, electrospun polycaprolactone nanofiber meshes (NFMs) are treated by radio‐frequency (RF) plasma using different gases (Ar or O2), power (20 or 30 W), and exposure time (5 or 10 min). Morphological and roughness analysis show topographical changes on the plasma‐treated NFMs. X‐ray photoelectron spectroscopy (XPS) results indicate an increment of the oxygen‐containing groups, mainly OH and CO, at the plasma‐treated surfaces. Accordingly, the glycerol contact angle results demonstrate a decrease in the hydrophobicity of plasma‐treated meshes, particularly in the O2‐treated ones. Three model cell lines (fibroblasts, chondrocytes, and osteoblasts) are used to study the effect of plasma treatments over the morphology, cell adhesion, and proliferation. A plasma treatment with O2 and one with Ar are found to be the most successful for all the studied cell types. The influence of hydrophilicity and roughness of those NFMs on their biological performance is discussed. Despite the often claimed morphological similarity of NFMs to natural extracellular matrixes, their surface properties contribute substantially to the cellular performance and therefore those should be optimized.
Comparative Investigation on Acid Hydrolysis of Sweet Potato Starches with Different Amylopectin Chain‐Length
Authors: Genkina Natalia K. , Kiseleva Valentina I. , Noda Takahiro 
Published: April 2009

AbstractThe solubilization of starch from the new sweet potato cultivar “Quick Sweet” (QS) in 2.2 M aqueous HCl occurred at a much higher rate than that from normal sweet potato (NS). QS starch has an abnormal amylopectin chain‐length distribution with an unusually high percentage of short side‐chains. Two‐stage hydrolysis occurred in both cases. The apparent first‐order kinetic constants (k) were calculated for both stages of the hydrolytic process in both types of sweet potato starch. A more drastic difference between the investigated starches (k for QS and NS starches was 27.0×10‐2 d‐1 and 7.0×10‐2 d‐1, respectively) was observed for the first stage of the hydrolysis affecting the amorphous regions of starches whereas the rate for the second stage (the degradation of the crystalline part) for the starch from QS was only slightly higher. The role of the structural defectiveness of QS in decreasing the granular resistance to acid hydrolysis and increasing the absorptive properties of the granules for water molecules is discussed.
Effect of deviation of nuchal translucency measurements on the performance of screening for trisomy 21
Authors: Kagan K. O. , Wright D. , Etchegaray A. , Zhou Y. , Nicolaides K. H. 
Published: April 2009

AbstractObjectivesTo examine the effect of deviations in median nuchal translucency thickness (NT) and the spread in measurements on the performance of screening for trisomy 21 by maternal age and fetal NT, and by maternal age, fetal NT and maternal serum biochemistry.MethodsWe simulated the NT and multiples of the median values for pregnancy‐associated plasma protein‐A (PAPP‐A) and free β‐human chorionic gonadotropin (β‐hCG) for 500 000 euploid and 500 000 trisomy 21 pregnancies at 12 weeks of gestation. Detection rates for trisomy 21 and false‐positive rates were calculated without adjustments in NT and by adding or subtracting values ranging from 0.1 to 1.0 mm to each observed measurement. In addition, the effects of variation in the scatter of NT measurements were examined by applying a multiplicative factor ranging from 0.5 to 2 to the SD.ResultsThe detection rate of trisomy 21 for a fixed false‐positive rate of 3% in screening by maternal age and fetal NT was 72%, and in screening by maternal age, fetal NT and serum free β‐hCG and PAPP‐A it was 86%. A consistent underestimate or overestimate in the measured NT reduced the detection rate of trisomy 21 for a fixed‐false positive rate. At a fixed screen‐positive cut‐off an underestimate in fetal NT reduced the detection rate whereas an overestimate in NT increased the false‐positive rate. A widening in the scatter of measurements had only a small impact on the detection rate but it caused a major increase in the false‐positive rate.ConclusionsHigh performance of screening necessitates appropriate measurement of fetal NT. This paper demonstrates the effect of deviations in the median and SD of NT from the expected on the performance of screening and can form the basis of audit of results of individual sonographers. Copyright © 2009 ISUOG. Published by John Wiley & Sons, Ltd.
Effects of parameter changes on the structure and properties of low‐density polyethylene foam
Authors: Zakaria Z. , Ariff Z.M. , Sipaut C.S. 
Published: April 2009

AbstractSeveral parameters, such as crosslinking agent concentration, blowing agent concentration, and temperature, were varied to evaluate their effects on the structure and mechanical properties of low‐density polyethylene (LDPE) foams. Dicumyl peroxide (DCP) was used as crosslinking agent, while azodicarbonamide (ADC) was utilized as the blowing agent at different levels. The formulations were prepared by using a thermostatically controlled heated two‐roll mill and foamed by using a compression molding technique via a single‐stage foaming process at three foaming temperatures (165, 175, and 185°C). The resultant LDPE foams were characterized and found to have a closed cell structure. The density and gel content increased proportionally with crosslinking level, whereas density decreased when ADC level and foaming temperature were increased. Another characteristic evaluated was the foam cell size decreased when the crosslinking level and foaming temperature were increased. In contrast, increasing the ADC concentration only gave a maximum cell size increase up to 6 phr that decreased when 8 phr of ADC was used. Results also indicated that compression stress increased proportionally with DCP level and decreased when ADC concentration and foaming temperature were increased. Impact studies on the prepared foams showed that their ability to absorb impact energy decreased with increasing crosslinking level, foaming temperature, and blowing agent concentration. J. VINYL ADDIT. TECHNOL., 2009. © 2009 Society of Plastics Engineers
Improved properties of cotton by atmospheric pressure plasma polymerization deposition of sericin
Authors: Jiang X.‐M. , Rui Y.‐N. , Chen G.‐Q. 
Published: April 2009

AbstractCotton fabric was exposed to an atmospheric pressure glow discharge (APGD) ignited by high voltage and helium. Ultrasonic atomization of an aqueous sericin solution injected as an aerosol into the APGD zone gave rise to the rapid deposition of a functionalized plasma polymer film. Sericin coating onto the cotton surface was confirmed by scanning electron microscopy, and the chemical composition was analyzed by Fourier transform infrared spectrophotometry and X‐ray photoelectron spectroscopy. It was found that the plasma power could affect the chemistry of the coating. The treated fabrics were tested for UV resistance, crease recovery angle, and water uptake. Results showed that these properties had been improved. J. VINYL ADDIT. TECHNOL., 2009. © 2009 Society of Plastics Engineers
New insights into the compulsion to use tobacco from an adolescent case‐series
Authors: DiFranza Joseph R. , Ursprung W.W. Sanouri , Carson Alisha 
Published: April 2009

ABSTRACTNicotine addiction is the most common preventable cause of premature death presenting during adolescence. No prior study has described the onset of this condition based on case histories. We used trained personnel to conduct individual semi‐structured interviews to obtain case histories from 50 adolescent and young adult current and former smokers.Smokers experience a compulsion to use tobacco that spans a spectrum of severity from wanting, to craving, to needing. The compulsion is commonly experienced as originating foreign to the will of the smoker and recurs with a predictable periodicity that determines the latency from smoking one cigarette to wanting, craving or needing another. Novice smokers could experience latencies as lengthy as a few weeks, and more experienced smokers attributed their escalation in smoking frequency to the shortening of their latencies. Wanting, craving or needing tobacco, as described in this study, are pathognomonic for a compulsion to use tobacco.
Ist eine gesetzliche Impfpflicht ethisch zu rechtfertigen?
Authors: Marckmann Georg 
Published: April 2009

Einleitung
Trotz überzeugender Argumente für die Durchführung aktiver Schutzimpfungen liegen die Durchimpfungsraten immer noch unter den angestrebten Werten. Damit wird das Potenzial der verfügbaren effektiven und sicheren Impfstoffe, d.h. die Möglichkeit zur Senkung der infektionsbedingten Morbidität und Mortalität nicht ausgeschöpft. Angesichts der guten Effektivität und auch Kosteneffektivität von Impfmaßnahmen stellt sich deshalb die Frage, ob Impfungen nicht per Gesetz vorgeschrieben werden sollten.
Quaternary reactivation of a basement structure in the Barreirinhas Basin, Brazilian Equatorial Margin
Authors: Almeida-Filho Raimundo , Rossetti Dilce F. , Miranda Fernando P. , Ferreira Francisco J. , Silva Clauzionor , Beisl Carlos 
Published: April 2009

AbstractThe Pirapemas Lineament is a remarkable 200-km-long, NE–SW trending structure in the Barreirinhas Basin, one of the several Brazilian coastal basins. This lineament splits the study area in two sectors of distinctive morphology, drainage patterns, and sedimentary covers. Terrain northward of the lineament presents a smooth topography with sub-parallel to sub-dendritic drainage patterns, whereas a dissected plateau characterized by incised valleys and rectangular drainage pattern occurs southward, suggesting a structural control by joints and faults. Geological field data, crossed with thermal luminescence (TL) and optically stimulated luminescence (OSL) dating, revealed that the surface southward of the lineament consists mostly of Miocene and late Pleistocene sedimentary deposits, represented by the Barreiras Formation and the Post-Barreiras sediments, respectively. In contrast, relatively younger sands mantle most of the northward terrain, as indicated by well-preserved paleodune deposits that grade into active aeolian dunes of the Lençóis Maranhenses National Park. Geomorphological and geological data analysis suggests that the northern sector is under the effect of subsidence, proving that the Pirapemas Lineament is an active agent modeling the landscape in the region. Geophysical data (gravity and seismic) confirm that such a structural feature is the surface expression of an active deep-seated basement fault.
Age dependence of plasma phospholipid fatty acid levels: potential role of linoleic acid in the age-associated increase in docosahexaenoic acid and eicosapentaenoic acid concentrations
Authors: de Groot Renate H. M. , van Boxtel Martin P. J. , Schiepers Olga J. G. , Hornstra Gerard , Jolles Jelle 
Published: April 2009

Limited information is available with respect to the association between age and the plasma phospholipid fatty acid profile. Therefore we investigated the association between plasma phospholipid fatty acid status and age after correction for sex, smoking, alcohol use, BMI and fish intake. Plasma phospholipid fatty acid composition was measured and information on fish intake and other potential covariates was collected in 234 participants of the Maastricht Aging Study. The participants were healthy individuals of both sexes with an age range between 36 and 88 years. Hierarchical linear regression analyses were applied to study the relationship between age and fatty acid concentrations. After correction for fish consumption and other relevant covariates, a significant positive relationship was observed between age of the subjects and their plasma phospholipid concentrations of DHA (22 : 6n-3,P = 0·006) and EPA (20 : 5n-3;P = 0·001). Age contributed 2·3 and 3·9 % to the amount of explained variance, respectively. The highern-3 long-chain PUFA status at advanced age was confirmed by lower concentrations of their putative ‘shortage marker’ Osbond acid (ObA, 22 : 5n-6;P = 0·022 for the relationship with age after correction for covariates and fish intake,R20·022). Concentrations of linoleic acid (LA; 18 : 2n-6) were negatively associated with age (P < 0·001;R20·061). In conclusion, DHA and EPA concentrations appeared to be higher in older age groups, partly because of a higher fish intake and partly because of another age-associated mechanism, possibly involving the well-known competition with LA.
Self-organization in a driven dissipative plasma system
Authors: SHAIKH DASTGEER , DASGUPTA B. , HU Q. , ZANK G. P. 
Published: April 2009

AbstractWe perform a fully self-consistent three-dimensional numerical simulation for a compressible, dissipative magnetoplasma driven by large-scale perturbations, that contain a fairly broad spectrum of characteristic modes, ranging from largest scales to intermediate scales and down to the smallest scales, where the energy of the system is dissipated by collisional (ohmic) and viscous dissipations. Additionally, our simulation includes nonlinear interactions amongst a wide range of fluctuations that are initialized with random spectral amplitudes, leading to the cascade of spectral energy in the inertial range spectrum, and takes into account large-scale as well as small-scale perturbations that may have been induced by the background plasma fluctuations, as well as the non-adiabatic exchange of energy leading to the migration of energy from the energy-containing modes or randomly injected energy driven by perturbations and further dissipated by the smaller scales. Besides demonstrating the comparative decays of the total energy and the dissipation rate of the energy, our results show the existence of a perpendicular component of the current, thus clearly confirming that the self-organized state is non-force free.
Morphological and molecular characterization of renal ciliates infecting farmed snails in Spain
Authors: SEGADE P. , KHER C. P. , LYNN D. H. , IGLESIAS R. 
Published: April 2009

SUMMARYRenal infections by parasitic ciliates were studied in adult snails ofHelix aspersa aspersaandHelix aspersa maximacollected from 2 mixed rearing system-based heliciculture farms located in Galicia (NW Spain). The occurrence of ciliates was also examined in slugs (Deroceras reticulatum) invading the greenhouses where first growing and fattening of snails is carried out. Histological examinations revealed a severe destruction of the renal epithelium in heavily infected hosts. Three ciliate isolates, one from each host species, were obtained and grown in axenic cultures. Cultured and parasitic ciliates were characterized morphologically and morphometrically. In addition, the encystment behaviour, the occurrence of autogamy, and the sequences of the mitochondrial cytochrome-coxidase subunit 1 (cox1) and the small subunit ribosomal RNA (SSU rRNA) genes were also studied in the 3 isolates. A polymorphic life cycle involving resting and reproductive cysts, together with the morphological and morphometrical characteristics and the confirmation that autogamy occurs within cysts, demonstrate that our ciliates belong to the speciesTetrahymena rostrata(Kahl, 1926) Corliss, 1952. The 3 isolates formed a well-supported clade using both genetic markers, and were clearly separate from the strain ATCC® 30770™, which has been identified asTetrahymena rostrata. We argue that our Spanish isolates should be regarded asTetrahymena rostrata, and that the ATCC isolate should be regarded as a misidentification as neither cytological nor cytogenetical support for its identity has been presented.
Stage-specific expression of NcSAG4as a marker of chronicNeospora caninuminfection in a mouse model
Authors: AGUADO-MARTÍNEZ A. , ORTEGA-MORA L. M. , ÁLVAREZ-GARCÍA G. , RODRÍGUEZ-MARCO S. , RISCO-CASTILLO V. , MARUGÁN-HERNÁNDEZ V. , FERNÁNDEZ-GARCÍA A. 
Published: April 2009

SUMMARYNeospora caninuminfection persists throughout the life of its intermediate host due to the conversion of tachyzoites to slowly dividing bradyzoites that encyst in the brain. This event results in persistentN. caninuminfection in bovine herds and partially explains the poor efficacy of many chemotherapeutic agents and vaccine formulations. Thus, there is a need for greater understanding of the tachyzoite-to-bradyzoite conversion mechanisms. Here we studied for the first time the transcription kinetics of theN. caninumbradyzoite-specific gene NcSAG4in brain samples from chronically infected mice by means of real-time RT-PCR. NcSAG4-messenger RNA (mRNA) levels increased significantly during the chronic phase but followed 2 different expression patterns depending on the isolate used for murine inoculation. NcSAG4-mRNA levels in brains from Nc-1-inoculated mice peaked during late chronic infection (on day 64 post-infection, p.i.), whereas those from Nc-Liv-inoculated mice peaked earlier during the chronic infection (on day 32 p.i.). This difference could be a reflection of the different abilities of these isolates to replicate and form cysts in parasitized brains. These results are consistent with our observations of anti-rNcSAG4 antibody production; low levels were present at seroconversion and slowly increased during the chronic phase. In contrast, NcSAG1transcription levels, which mark the tachyzoite stage, were maintained without variation in both groups of mice. This suggests the presence of a significant amount of tachyzoites or intermediate zoites expressing NcSAG1in the brain, even during the late chronic infection.
Hatching behaviour of Nematodirus filicollis in a flock co-infected with Nematodirus battus
Authors: VAN DIJK J. , MORGAN E. R. 
Published: April 2009

SUMMARYThe development and survival of larvae of Nematodirus filicollis, an important nematode parasite of ruminants, were extensively investigated in the laboratory for the first time, using eggs harvested from sheep grazing in the UK in winter. Third-stage larvae (L3s) developed within the eggs between 12 and 25°C, with the proportion of eggs developing successfully being highest at the upper end of this range. Eggs required chilling below 10°C before being able to hatch at all, and maximum hatch was observed only following chilling to 4°C. Hatching occurred above 6°C, and peaked at 13°C, with the proportion of eggs hatching decreasing to 17–20°C, which appears to form an upper threshold temperature for hatching. When fully developed eggs were placed at 11–13°C, L3 emerged very rapidly with hatching being completed within 6 days. Mortality of emerged L3s increased with temperature, particularly above 20°C. For this parasite, given the low minimum hatching thresholds and the rapid emergence of L3, the existence of an upper hatching threshold is likely to have limited impact on patterns of larval availability on pasture. The strict requirement for chilling is surprising, being at odds with both previous observations and the wide geographical distribution of this species. It is possible that the proportion of eggs requiring chilling is an adaptable trait, enabling early infection of naïve hosts in the face of competition from N. battus, yet also persistence in regions that do not provide good conditions for the chilling of eggs. Further study of selectable variation in this trait could help us to understand the contrasting geographical ranges and disease patterns within the genus, and how different species might respond to climate change.
ORDER STATISTICS FROM DEPENDENT, COMPLETELY MONOTONE DISTRIBUTIONS
Authors: Brown Mark 
Published: April 2009

We consider order statistics corresponding to X1, …, Xn, where $X_{i} \sim \lambda_{i}^{-1} \cal{E}$, i = 1, …, n, ℰ1, …, ℰn are independent and identically distributed exponentials with mean 1, and λ1, …, λn are possibly dependent, possibly nonidentically distributed, positive random variables, with $E\lambda_{i}^{-1} < \infty$. Thus, λ1, …, λn, can be interpreted as random failure rates, and their dependency might be due to common environmental factors.