bluuebunny/crossref_metadata_2025_split huggingface dataset:
Enantioselective toxicological response of the green alga Scenedesmus obliquus to isocarbophos
Authors: Lu Dahai , Huang Ledan , Diao Jinling , Zhou Zhiqiang 
Published: April 2012

ABSTRACTChiral compounds usually behave enantioselectively in phyto‐biochemical processes. Isocarbophos (ICP) is a chiral pesticide that is widely used. To evaluate the toxicological response of ICP and its enantiomers to Scenedesmus obliquus, algal growth, total chlorophyll, total soluble protein, and the superoxide anion radicals (O2•‐) were investigated. The microalgae were treated with ICP and its enantiomers at 0.01–10 mg/l for 96 h. The growth of S. obliquus was stimulated at low levels of ICP and its enantiomers (0.01–1 mg/l), but all were inhibited at high concentrations (10 mg/l). The total soluble protein content and total chlorophyll content of the tested green alga S. obliquus gradually increased, depending on the growth of algal cells in the medium. Meanwhile, the content of O2•‐ was decreased. Interestingly, the cell number and content of the chlorophylls and protein decreased with increasing levels of concentration, whereas O2•‐ increased. Our results indicated that enantioselectivity was observed in the dose–response of ICP and its enantiomers in S. obliquus. The high O2•‐ level might lead to the death of S. obliquus. The stimulation of growth suggests a regulatory mechanism that is related to the capability of the algae to adapt to the O2•‐. Chirality 24:481–485, 2012. © 2012 Wiley Periodicals, Inc.
Analysis of Chirality by Femtosecond Laser Ionization Mass Spectrometry
Authors: Horsch Philipp , Urbasch Gunter , Weitzel Karl‐Michael 
Published: April 2012

ABSTRACTRecent progress in the field of chirality analysis employing laser ionization mass spectrometry is reviewed. Emphasis is given to femtosecond (fs) laser ionization work from the author's group. We begin by reviewing fundamental aspects of determining circular dichroism (CD) in fs‐laser ionization mass spectrometry (fs‐LIMS) discussing an example from the literature (resonant fs‐LIMS of 3‐methylcyclopentanone). Second, we present new data indicating CD in non‐resonant fs‐LIMS of propylene oxide.Chirality 24:684–690, 2012. © 2012 Wiley Periodicals, Inc.
Conformational Flexibility and Absolute Stereochemistry of (3R)‐3‐hydroxy‐4‐aryl‐β‐lactams Investigated by Chiroptical Properties and TD‐DFT Calculations
Authors: Tedesco Daniele , Zanasi Riccardo , Guerrini Andrea , Bertucci Carlo 
Published: April 2012

ABSTRACTThe effect of conformational flexibility on the chiroptical properties of a series of synthetic (3R)‐3‐hydroxy‐4‐aryl‐β‐lactams of known stereochemistry (1–6) was investigated by means of electronic circular dichroism (ECD) measurements and time‐dependent density functional theory (TD‐DFT) calculations. The application of the β‐lactam sector rules allowed a correct stereochemical characterization of these compounds, with the exception of a thienyl‐substituted derivative (cis‐6). TD‐DFT calculations yielded accurate predictions of experimental ECD spectra and [α]D values, allowing us to assign the correct absolute configuration to all the investigated compounds. A detailed analysis of the β‐lactam ring equilibrium geometry on optimized conformers identified regular patterns for the arrangement of atoms around the amide chromophore, confirming the validity of the β‐lactam sector rules. However, relevant variations in theoretical chiroptical properties were found for compounds bearing a heterocyclic substituent at C4 or a phenyl substituent at C3, whose conformers deviate from these regular geometric patterns. This behavior explains the failure of the β‐lactam sector rules in cis‐6. This study showed the importance of conformational flexibility for the determination of chiroptical properties and highlighted the strengths and weaknesses of the different methods for the stereochemical characterization of chiral molecules in solution. Chirality 24:741‐750, 2012. © 2012 Wiley Periodicals, Inc.
Fine‐scale parallel patterns in diversity of small benthic Arctic charr (Salvelinus alpinus) in relation to the ecology of lava/groundwater habitats
Authors: Kristjánsson Bjarni K. , Skúlason Skúli , Snorrason Sigurður S. , Noakes David L.G. 
Published: April 2012

AbstractIt is critical to study factors that are important for origin and maintenance of biological diversity. A comparative approach involving a large number of populations is particularly useful. We use this approach to study the relationship between ecological factors and phenotypic diversity in Icelandic Arctic charr (Salvelinus alpinus). Numerous populations of small benthic charr have evolved in lava springs in Iceland. These charr appear morphologically similar, but differ in important morphological features related to feeding. We found a clear relationship between diversity in morphology, diet, and ecological factors among populations. In particular, there were clear differences in morphology and diet between fish coming from habitats where the lava spring flowed on as a stream compared to habitats where the lava spring flowed into a pond. Our study shows that ecological factors are important for the origin and maintenance of biological diversity. The relationship between phenotype and ecological factors are observed on a fine scale, when comparing numerous populations that are phenotypically similar. This strongly suggests that for understanding, managing, and conserving biological diversity important ecological variables have to be taken into the account.
HOW MANY INFANTS LIKELY DIED IN AFRICA AS A RESULT OF THE 2008–2009 GLOBAL FINANCIAL CRISIS?
Authors: Friedman Jed , Schady Norbert 
Published: April 2012

ABSTRACTThe human consequences of the recent global financial crisis for the developing world are presumed to be severe, but few studies have quantified them. This letter estimates the human cost of the 2008–2009 global financial crisis in one critical dimension—infant mortality—for countries in sub‐Saharan Africa. The analysis pools birth‐level data, as reported in female adult retrospective birth histories from all Demographic and Health Surveys collected in sub‐Saharan Africa. This results in a data set of 639,000 births to 264,000 women in 30 countries. We use regression models with flexible controls for temporal trends to assess an infant's likelihood of death as a function of fluctuations in national income. We then calculate the expected number of excess deaths by combining these estimates with growth shortfalls as a result of the crisis. The results suggest 28,000–50,000 excess infant deaths in sub‐Saharan Africa in the crisis‐affected year of 2009. Notably, most of these additional deaths were concentrated among girls. Policies that protect the income of poor households and that maintain critical health services during times of economic contraction may reduce the expected increase in mortality. Interventions targeted at female infants and young girls can be particularly beneficial. Copyright © 2012 John Wiley & Sons, Ltd.
ON THE ROLE OF THE TROPICS IN THE GENERAL CIRCULATION OF THE ATMOSPHERE
Authors: Riehl Herbert 
Published: April 2012

ABSTRACTPresent knowledge on the role of the tropics in the general circulation is reviewed in comparison with our knowledge twenty years ago. Increasing amounts of upper‐air data in the tropics since that time plus the advent of rawin measurements have placed many calculations of the mean seasonal exchange of heat, moisture and angular momentum between the tropics and the extratropical regions on a fairly firm basis. The large troughs seen extending from higher latitudes to the heart of the tropics even with late World War II observations have been confirmed in their role as the principal exchange mechanism. On the other hand, the mean meridional circulation can account for the upward transport of angular momentum which is generated with easterlies within the tropics and also for the net generation of kinetic energy south of 30°N. About 50 per cent of the kinetic energy required north of 30°N in winter to maintain the circulation against frictional dissipation, is imported from the tropics by means of the standing waves of the subtropical jet‐stream. Hence it is clear that the tropics help to sustain the kinetic energy of the westerlies and that the tropical circulation is not driven from higher latitudes as often claimed.The sense of total energy transport by the mean meridional circulation inside the tropics is not easily calculated and may even reverse sign. Complications on total energy export also have arisen through the nimbus ii albedo observations which have shown lower albedo (less cloudiness), hence also a larger energy source, for the tropics than previously estimated. It appears certain, merely, that the equatorial trough migrates seasonally so that energy very likely does not pass through it, hence that it constitutes a true “meteorological equator”. No evidence concerning important coupling between the hemispheres across the equator has come to light; however, the new data systems of the next decade may well alter this conclusion.Because of the sensitive computational situation concerning energy transport by the mean meridional circulation, it may be that successful operational application of cloud seeding techniques, such as demonstrated in Project Stormfury in the Caribbean, could exert a subtle influence on the general circulation. This apart, the present status of observational networks is judged to be so far advanced that fluctuations of quantities such as the mean meridional circulation within a season, and in the same month from year to year, can shortly be calculated, possibly shedding light on the variability of the general circulation and precipitation excesses and deficits in tropical regions.
Direct Electrochemistry of Glucose Oxidase Immobilized on Titanium Carbide‐Au Nanoparticles‐Fullerene C60 Composite Film and Its Biosensing for Glucose
Authors: Wang Minzhi , Zheng Jianbin , Wang Lu , Dong Sheying 
Published: April 2012

AbstractThe direct electrochemistry of glucose oxidase (GOD) immobilized on the designed titanium carbide‐Au nanoparticles‐fullerene C60 composite film modified glassy carbon electrode (TiC‐AuNPs‐C60/GCE) and its biosensing for glucose were investigated. UV‐visible and Fourier‐transform infrared spectra of the resulting GOD/TiC‐AuNPs‐C60 composite film suggested that the immobilized GOD retained its original structure. The direct electron transfer behaviors of immobilized GOD at the GOD/TiC‐AuNPs‐C60/GCE were investigated by cyclic voltammetry in which a pair of well‐defined, quasi‐reversible redox peaks with the formal potential (E0′) of ‐0.484 V (vs. SCE) in phosphate buffer solution (0.05 M, pH 7.0) at the scan rate of 100 mV·s−1 were obtained. The proposed GOD modified electrode exhibited an excellent electrocatalytic activity to the reduction of glucose, and the currents of glucose reduction peak were linearly related to glucose concentration in a wider linearity range from 5.0 × 10−6 to 1.6 × 10−4 M with a correlation coefficient of 0.9965 and a detection limit of 2.0 × 10−6 M (S/N = 3). The sensitivity and the apparent Michaelis‐Menten constant (KMapp) were determined to be 149.3 μA·mM−1·cm−2 and 6.2 × 10−5 M, respectively. Thus, the protocol will have potential application in studying the electron transfer of enzyme and the design of novel electrochemical biosensors.
Direct Nanopatterning Into Conjugated Polymers Using Interference Crosslinking
Authors: Zhang Xinping , Liu Hongmei , Li Hongwei , Zhai Tianrui 
Published: April 2012

AbstractNanoscale photonic structures are patterned directly by exposing a thin film of conjugated polymer to the interference pattern of UV laser beams, thus inducing crosslinking between the polymer molecules in the bright fringes. The crosslinked polymer molecules become indissolvable in organic solvent due to the localized photochemical modification, enabling successful lift‐off of the soft grating structures. The resultant nanodevice exhibits excellent chemical and physical stability. This demonstrates the high spatial resolution of the crosslinking process and introduces a direct nanofabrication technique, which may be utilized in the design of optoelectronic and laser devices.
Temperature dependency of human muscle velocity recovery cycles
Authors: Bostock Hugh , Baumann Corina , Humm Andrea M. , Z'Graggen Werner J. 
Published: April 2012

AbstractIntroduction: Velocity recovery cycles (VRCs) of human muscle action potentials have been proposed as a new technique for studying muscle membrane function. This study was undertaken to determine the temperature dependency of VRC parameters. Methods: VRCs with 1 conditioning stimulus were recorded repeatedly from brachioradialis muscle during cooling, and intramuscular temperature was recorded. VRCs in 6 normal volunteers were measured at 1°C intervals from 34°C to 28°C. The effects of temperature on relative refractory period and early and late supernormality were quantified. Results: Muscle VRC curves shift progressively upward and to the right with cooler temperatures. The most sensitive parameter to temperature changes was relative refractory period, whereas early supernormality was rather insensitive. Late supernormality was unaffected by temperature changes. Conclusions: Knowledge of temperature‐induced changes of muscle VRC parameters is essential for future studies. Thus, the results of this study provide a firm basis for clinical studies with this technique. Muscle Nerve 46: 264–266, 2012
Validation of an adjustment equation for the burst superimposition technique in subjects post‐stroke
Authors: Knarr Brian A. , Higginson Jill S. , Binder‐MacLeod Stuart A. 
Published: April 2012

AbstractIntroduction: Deficits in voluntary force generation may be due to incomplete activation or decreased maximum force‐generating ability (MFGA) of the targeted muscle. The validity of techniques used to measure MFGA in individuals post‐stroke has not been assessed. The objective of this study was to determine the reliability of the MFGA predicted using an adjusted burst superimposition method within a post‐stroke population. Methods: Differences in paretic‐side plantar flexor muscle MFGA between 2 trials was calculated using the standard and adjusted burst superimposition technique for 17 individuals post‐stroke (15 men, 58.7 ± 10 years of age, ≥6 months post‐stroke) to assess reliability of the techniques. Results: The adjusted measurement was shown to be more reliable (P = 0.03), especially when volitional effort differed by >40 N. Conclusions: Reliable measurement of the MFGA in individuals who have sustained a stroke is of clinical importance. These results suggest that the adjusted burst superimposition method may be useful when performing multiple measurements of muscle performance. Muscle Nerve 46: 267–269, 2012
Outcome of prenatally detected bilateral higher urinary tract obstruction or megacystis: sex‐related study on a series of 709 cases
Authors: Al‐Hazmi Hamdan , Dreux Sophie , Delezoide Anne‐Lise , Dommergues Marc , Lortat‐Jacob Stephen , Oury Jean‐François , El‐Ghoneimi Alaa , Muller Françoise 
Published: April 2012

ABSTRACTObjectiveTo compare the sex specific outcome of fetuses with prenatally detected urinary tract dilatation, with the exclusion of pyelectasia.MethodIncluded in the study were 709 cases of major dilatation of the fetal urinary tract, diagnosed at routine ultrasound scan. For each sex group, cases were divided into two subgroups depending on the level of dilatation. Final diagnosis was based on postnatal evaluation or on fetal autopsy. Postnatal renal function was evaluated using serum creatinine at two years of age.ResultsBilateral higher urinary tract dilatation was prenatally observed in 148 (20.8%) and lower urinary tract obstruction or bladder dilatation in 561 (79.1%) of the 709 cases (121 female and 588 male fetuses) (P <0.001). Bladder dilatation was less frequent in female fetuses (62%) than in males (82.6%) (P <0.001). At final diagnosis, associated malformations were observed in 53.7% of female fetuses versus 11% in males (P <0.001). The survival rate was 42.7%. Postnatal renal function, evaluated in 289/303 live infants, was impaired in 29.7% of cases and depended on the level of obstruction, but not on the sex.ConclusionPrenatally detected urinary tract dilatation has a poor prognosis both in male and female fetuses. Associated malformations are observed more frequently in female than in male fetuses. © 2012 John Wiley & Sons, Ltd.
Thymic volume in healthy, small for gestational age and growth restricted fetuses
Authors: Olearo Elena , Oberto Manuela , Oggè Giovanna , Botta Giovanni , Pace Carlotta , Gaglioti Pietro , Todros Tullia 
Published: April 2012

ABSTRACTObjectiveThe aim of this study was to verify the hypothesis that a difference in thymic size exists between small for gestational age (SGA) fetuses, likely constitutional, and intrauterine growth restricted (IUGR) fetuses because of placental causes.MethodsWe studied 27 SGA and 36 control fetuses. SGA was defined as fetal abdominal circumference (AC) and birthweight <10th percentile for gestational age. We defined as constitutional SGA those with normal uterine and umbilical artery Doppler flow velocity waveforms (FVW), and as IUGR those with abnormal uterine FVW. IUGR were further divided based on normal or abnormal umbilical FVW. Fetal thymic volume (TV) was acquired by three‐dimensional ultrasound and reconstructed with virtual organ computer‐aided analysis. To correct for the influence of fetal size on thymic dimension, TV/AC ratio was calculated.ResultsControls presented a higher TV/AC compared with each group of SGA (p < 0.001). TV/AC was significantly lower in IUGR with abnormal umbilical FVW compared with both constitutional SGA (p = 0.01) and IUGR with normal umbilical FVW (p = 0.01).ConclusionsThe differences in TV/AC between constitutional SGA and IUGR with abnormal umbilical FVW suggest that, in the latter, a specific ‘trigger’ might compromise trophoblastic invasion and thymic development; however, some kind of alteration of the immune system might occur in all SGA fetuses. © 2012 John Wiley & Sons, Ltd.
Long‐term outcomes of the FRESH START trial: exploring the role of self‐efficacy in cancer survivors' maintenance of dietary practices and physical activity
Authors: Mosher Catherine E. , Lipkus Isaac , Sloane Richard , Snyder Denise C. , Lobach David F. , Demark‐Wahnefried Wendy 
Published: April 2012

AbstractBackgroundThis study examined whether changes in self‐efficacy explain the effects of a mailed print intervention on long‐term dietary practices of breast and prostate cancer survivors. The relationship between change in self‐efficacy and long‐term physical activity (PA) also was examined.MethodsBreast and prostate cancer survivors (N = 543) from 39 US states and two Canadian provinces participated in the FRESH START intervention trial. Participants were randomly assigned to receive a 10‐month program of mailed print materials on diet and PA available in the public domain or a 10‐month program of tailored materials designed to increase fruit and vegetable (F&V) intake, decrease fat intake, and/or increase PA. Changes in self‐efficacy for F&V intake and fat restriction were analyzed as potential mediators of the intervention's effects on diet at 2‐year follow‐up. Because we previously found that change in self‐efficacy for PA did not vary by group assignment, the relationship between change in self‐efficacy and PA at 2‐year follow‐up was examined across study conditions.ResultsResults suggest that change in self‐efficacy for fat restriction partially explained the intervention's effect on fat intake (mean indirect effect = −0.28), and change in self‐efficacy for F&V consumption partially explained the intervention's effect on daily F&V intake (mean indirect effect = .11). Change in self‐efficacy for fat restriction partially accounted for the intervention's impact on overall diet quality among men only (mean indirect effect = 0.60). Finally, change in self‐efficacy for PA predicted PA at 2‐year follow‐up.ConclusionsFindings suggest that self‐efficacy may influence long‐term maintenance of healthy lifestyle practices among cancer survivors. Copyright © 2012 John Wiley & Sons, Ltd.
Effect of in situ ultraviolet irradiation on the formation of nanostructural carbon nitride films
Authors: Shalaev R. V. , Prudnikov A. M. , Ulyanov A. N. , Shin G. M. , Yoo S. I. , Linnik A. I. , Linnik T. A. , Burkhovetskii V. V. , Varyukhin V. N. 
Published: April 2012

AbstractWe report the effect of in situ ultraviolet (UV) irradiation on the formation of carbon nitride CNx films. The nanocolumnar films were produced under UV irradiation without a metal catalyst by dc magnetron sputtering of a graphite target in an N2 atmosphere with 3% of O2 on a quartz glass substrate. It was shown that films have dense nanostructure with columns of 60–80 nm in diameter and with nitrogen concentration of ∼4%. Scanning electron microscopy (SEM) and X‐ray photoemission spectroscopy (XPS) data show the coexistence of amorphous and columnar phases. In situ UV irradiation was found to be effective for growing the pure nanocolumnar structure of carbon nitride by etching the amorphous phase.
Differentiation of enantiomeric drugs by iodo‐substituted L‐amino acid references under electrospray ionization mass spectrometric conditions
Authors: Karthikraj R. , Prabhakar S. , Vairamani M. 
Published: April 2012

RATIONALEIn chiral differentiation by mass spectrometry, use of a single reference that differentiates various classes of compounds including drugs is ideal, but so far there are no such reports in the literature. We have successfully used iodo‐substituted amino acids for the chiral differentiation of ten enantiomeric pairs of drugs.METHODSTo achieve the chiral differentiation, the trimeric Cu complex ion consisting of two chiral reference molecules and an analyte molecule was generated under positive ion electrospray ionization (ESI) conditions and subsequently subjected for collision‐ induced dissociation (CID) experiments using an LCQ ion trap mass spectrometer. The spectra were recorded under identical experimental conditions for both the enantiomers, and were averages of 30 scans. Cooks' kinetic method and chiral recognition ratio method (CR method) were used to arrive at the Rchiral/CR values, respectively.RESULTSThe Rchiralor CR values of the studied drugs are higher for 3,5‐diiodo‐L‐tyrosine as the reference, than for 4‐iodo‐L‐phenylalanine, except for isoproterenol and atenolol. Both the references show the same selectivity (R‐ or S‐selectivity) towards all the studied drugs. With 3,5‐diiodo‐L‐tyrosine as the reference, an Rchiralvalue of 12.75 is obtained for DOPA and this is the highest reported value in the literature till now. The suitability of the current method in measuring enantiomeric excess is also demonstrated for DOPA.CONCLUSIONSThe use of 4‐iodo‐L‐phenylalanine or 3,5‐diiodo‐L‐tyrosine as a chiral reference for the chiral differentiation of ten enantiomeric pairs of pharmaceutically important drugs has been demonstrated. The chiral differentiation of pregabalin, tenofovir and pramipexole is reported for the first time. This study shows that it is possible to develop a single chiral reference compound for the differentiation of a group of chiral drugs having some similarities. Copyright © 2012 John Wiley & Sons, Ltd.