bluuebunny/crossref_metadata_2025 huggingface dataset:
Enantiomeric separation of new cathinone derivatives designer drugs by capillary electrochromatography using a chiral stationary phase, based on amylose tris(5‐chloro‐2‐methylphenylcarbamate)
Authors: Aturki Zeineb , Schmid Martin G. , Chankvetadze Bezhan , Fanali Salvatore
Published: May 2014

In this study, a chiral CEC method for the enantiomeric separation of ten cathinone derivatives, by means of a polysaccharide‐based chiral stationary phase, has been developed. Capillary columns of 100 μm id packed with amylose tris(5‐chloro‐2‐methylphenylcarbamate) coated on silica, also called Sepapak 3 or Lux Amylose‐2, were used to achieve the enantioseparation of the studied designer drugs. Enantioresolution, chromatographic retention, and separation efficiency were evaluated in dependence of mobile‐phase composition in terms of the content of the organic modifier, nature, and pH buffer. To obtain a sensitivity improvement, a field‐amplified sample injection was evaluated optimizing the sample solvent composition and injection time. The LODs and LOQs values were in the range 25–100 and 50–150 ng/mL, respectively, for all the racemic compounds. Good results in terms of resolution (Rs), separation efficiency (N/m), and short analysis times were obtained using a mixture of ACN/methanol/sodium acetate pH 9 (89/10/1, v/v/v). Applying a voltage of 10 kV and a temperature of 20°C, the analyzed cathinone derivatives were separated in their enantiomers in less than 10 min. A study, concerning the method precision, in terms of intra‐ and interday repeatability and column‐to‐column reproducibility was carried out in accordance with the analytical procedures for method validation. Intra‐ and interday repeatability provided RSD values in the ranges 1.1–1.7, 1.3–2.3% for retention time and 1.3–2.6, 2.1–3.4% for peak area, respectively.
Antagonists of the P2X7 receptor: Mechanism of enantioselective recognition using highly sulfated and sulfobutylether cyclodextrins by capillary electrokinetic chromatography
Authors: Baudelet Davy , Ghinet Alina , Furman Christophe , Dezitter Xavier , Gautret Philippe , Rigo Benoit , Millet Régis , Vaccher Claude , Lipka Emmanuelle
Published: May 2014

This work concerns the successful enantiomeric separation of pyroglutamic acid derivatives, known to be P2X7 receptor antagonists, achieved by electrokinetic chromatography. After a broad screening, two negatively charged cyclodextrins, sulfobutylether‐β‐cyclodextrin (SBE‐β‐CD), and highly sulfated‐γ‐cyclodextrin (HS‐γ‐CD) were chosen as stereoselective agents to cooperate with the BGE for complexation. A fused silica capillary coated with polyethylene oxide, filled with a phosphate buffer (25 mM, pH 2.5) containing various concentrations of CD, was used. Assuming a 1:1 stoichiometry, calculations of the binding constants, employing the three different linearization plots, were performed from the corrected electrophoretic mobilities values of the enantiomers, at different concentrations of SBE‐β‐CD and HS‐γ‐CD in the BGE. The highest complexation was found with the SBE‐β‐CD. Among the three equations, results showed better linearity (R2 > 0.99) using the y‐reciprocal fit. This plotting method was then performed to determine the binding constants of each enantiomer at different temperature for compounds 1 and 2 with SBE‐β‐CD and HS‐γ‐CD in order to access to the thermodynamic parameters of the eight complexes. The linearity of the Van't Hoff plot, in the range of 288–303 K leading to negative enthalpy values, showed that the complexation phenomenon is enthalpically controlled and thermodynamically favored.
Evaluation of amino acid ester‐based ionic liquids as buffer additives in CE for the separation of 2‐arylpropionic acids nonsteroidal anti‐inflammatory drugs
Authors: Mavroudi Maria C. , Kapnissi‐Christodoulou Constantina P.
Published: May 2014

The aim of the present study is the CE performance evaluation for the separation of 2‐arylpropionic acid nonsteroidal anti‐inflammatory drugs. In particular, the separation of indoprofen, carprofen, ketoprofen, ibuprofen, and flurbiprofen was obtained by supporting the BGE either with SDS or an amino acid ester‐based ionic liquid (AAIL). The performance of these additives was evaluated by comparing migration times, efficiencies and %RSD values. The addition of the AAIL into the BGE provided baseline separation within 10 min, while in the case of SDS, the analytes eluted within 23 min. The optimum conditions involve a BGE of 100 mM Tris/10 mM sodium tetraboratedecahydrate (pH 8) and 40 mM l‐alanine tert butyl ester lactate or 10 mM SDS and a temperature of 35°C for AAIL and 20°C for SDS. The run‐to‐run reproducibility was evaluated by computing the %RSD values of the EOF and the analyte peaks. When the AAIL was used, an excellent reproducibility was obtained, since all %RSD values were below 1.3%. On the contrary, the addition of SDS resulted in much higher RSD values (2.1–11.7%). The efficiency values of all analyte peaks were above 102 000 for l‐AlaC4Lac, in comparison to SDS, which provided efficiency values between 47000 and 76000. Finally, in an attempt to study the synergistic effect of SDS and AAIL, both additives were added into the BGE at concentrations of 10 and 40 mM, respectively. The results were similar to the ones obtained when SDS was used as the sole additive.
The Forecasting Performance of a Finite Mixture Regime‐Switching Model for Daily Electricity Prices
Authors: Chen Dipeng , Bunn Derek
Published: May 2014

Forecasting prices in electricity markets is a crucial activity for both risk management and asset optimization. Intra‐day power prices have a fine structure and are driven by an interaction of fundamental, behavioural and stochastic factors. Furthermore, there are reasons to expect the functional forms of price formation to be nonlinear in these factors and therefore specifying forecasting models that perform well out‐of‐sample is methodologically challenging. Markov regime switching has been widely advocated to capture some aspects of the nonlinearity, but it may suffer from overfitting and unobservability in the underlying states. In this paper we compare several extensions and alternative regime‐switching formulations, including logistic specifications of the underlying states, logistic smooth transition and finite mixture regression. The finite mixture approach to regime switching performs well in an extensive, out‐of‐sample forecasting comparison. Copyright © 2014 John Wiley & Sons, Ltd.
Atomic dynamic functional interaction patterns for characterization of ADHD
Authors: Ou Jinli , Lian Zhichao , Xie Li , Li Xiang , Wang Peng , Hao Yun , Zhu Dajiang , Jiang Rongxin , Wang Yufeng , Chen Yaowu , Zhang Jing , Liu Tianming
Published: May 2014

Modeling abnormal temporal dynamics of functional interactions in psychiatric disorders has been of great interest in the neuroimaging field, and thus a variety of methods have been proposed so far. However, the temporal dynamics and disease‐related abnormalities of functional interactions within specific data‐driven discovered subnetworks have been rarely explored yet. In this work, we propose a novel computational framework composed of an effective Bayesian connectivity change point model for modeling functional brain interactions and their dynamics simultaneously and an effective variant of nonnegative matrix factorization for assessing the functional interaction abnormalities within subnetworks. This framework has been applied on the resting state fmagnetic resonance imaging (fMRI) datasets of 23 children with attention‐deficit/hyperactivity disorder (ADHD) and 45 normal control (NC) children, and has revealed two atomic functional interaction patterns (AFIPs) discovered for ADHD and another two AFIPs derived for NC. Together, these four AFIPs could be grouped into two pairs, one common pair representing the common AFIPs in ADHD and NC, and the other abnormal pair representing the abnormal AFIPs in ADHD. Interestingly, by comparing the abnormal AFIP pair, two data‐driven abnormal functional subnetworks are derived. Strikingly, by evaluating the approximation based on the four AFIPs, all of the ADHD children were successfully differentiated from NCs without any false positive. Hum Brain Mapp 35:5262–5278, 2014. © 2014 Wiley Periodicals, Inc.
Functionally connected brain regions in the network activated during capsaicin inhalation
Authors: Farrell Michael J. , Koch Saskia , Ando Ayaka , Cole Leonie J. , Egan Gary F. , Mazzone Stuart B.
Published: May 2014

Coughing and the urge‐to‐cough are important mechanisms that protect the patency of the airways, and are coordinated by the brain. Inhaling a noxious substance leads to a widely distributed network of responses in the brain that are likely to reflect multiple functional processes requisite for perceiving, appraising, and behaviorally responding to airway challenge. The broader brain network responding to airway challenge likely contains subnetworks that are involved in the component functions required for coordinated protective behaviors. Functional connectivity analyses were used to determine whether brain responses to airway challenge could be differentiated regionally during inhalation of the tussive substance capsaicin. Seed regions were defined according to outcomes of previous activation studies that identified regional brain responses consistent with cough suppression, stimulus intensity coding, and perception of urge‐to‐cough. The subnetworks during continuous inhalation of capsaicin recapitulated the distributed regions previously implicated in discrete functional components of airway challenge. The outcomes of this study highlight the central representation of airways defence as a distributed network. Hum Brain Mapp 35:5341–5355, 2014. © 2014 Wiley Periodicals, Inc.
Serotonin transporter gene methylation is associated with hippocampal gray matter volume
Authors: Dannlowski Udo , Kugel Harald , Redlich Ronny , Halik Adriane , Schneider Ilona , Opel Nils , Grotegerd Dominik , Schwarte Kathrin , Schettler Christiane , Ambrée Oliver , Rust Stephan , Domschke Katharina , Arolt Volker , Heindel Walter , Baune Bernhard T. , Suslow Thomas , Zhang Weiqi , Hohoff Christa
Published: May 2014

Background

The serotonin transporter (5‐HTT) and the 5‐HTTLPR/rs25531 polymorphisms in its gene (SLC6A4) have been associated with depression, increased stress‐response, and brain structural alterations such as reduced hippocampal volumes. Recently, epigenetic processes including SLC6A4 promoter methylation were shown to be affected by stress, trauma, or maltreatment and are regarded to be involved in the etiology of affective disorders. However, neurobiological correlates of SLC6A4 promoter methylation have never been studied or compared to genotype effects by means of human neuroimaging hitherto

Methods

Healthy subjects were recruited in two independent samples (N = 94, N = 95) to obtain structural gray matter images processed by voxel‐based morphometry (VBM8), focusing on hippocampal, amygdala, and anterior cingulate gyrus gray matter structure. SLC6A4 promoter methylation within an AluJb element and 5‐HTTLPR/rs25531 genotypes were analyzed in view of a possible impact on local gray matter volume

Results

Strong associations of AluJb methylation and hippocampal gray matter volumes emerged within each sample separately, which in the combined sample withstood most conservative alpha‐corrections for the entire brain. The amygdala, insula, and caudate nucleus showed similar associations. The 5‐HTTLPR/rs25531 showed no main effect on gray matter, and the effect of methylation rates on hippocampal structure was comparable among the genotype groups

Conclusions

Methylation within the AluJb appears to have strong effects on hippocampal gray matter volumes, indicating that epigenetic processes can alter brain structures crucially involved in stress‐related disorders. Different ways of regulating SLC6A4 expression might involve exonization or transcription factor binding as potentially underlying mechanisms, which, however, is speculative and warrants further investigation. Hum Brain Mapp 35:5356–5367, 2014. © 2014 Wiley Periodicals, Inc.
A New Multifunctional TriazineCarbazole Compound with High Triplet Energy for High‐Performance Blue Fluorescence, Green and Red Phosphorescent Host, and Hybrid White Organic Light‐Emitting Diodes
Authors: Liu Xiao‐Ke , Zheng Cai‐Jun , Xiao Jing , Lo Ming‐Fai , Chen Zhan , Lee Chun‐Sing , Liu Chuan‐Lin , Ou Xue‐Mei , Li Fan , Zhang Xiao‐Hong
Published: May 2014

A blue fluorescent compound, 9‐[4‐(4,6‐diphenoxy‐1,3,5‐triazin‐2‐yl)phenyl]‐9H‐carbazole (POTC), the triplet energy level of which reaches 2.76 eV, has been designed and synthesized. POTC is an excellent blue emitter as well as host for green and red phosphors, and therefore, matches the requirements of the host for single‐emitting‐layer fluorescence and phosphorescence hybrid white organic light‐emitting diodes (OLEDs). The blue, green, red, and white devices based on POTC show maximum external quantum efficiencies (EQEs) of 2.4, 22.4, 13.0, and 8.1 %, respectively. Even at a high brightness of 1000 cd m−2, these values maintain EQEs of 2.3, 22.1, 11.1, and 7.0 %, respectively, indicating less than 15 % roll‐offs from the maxima.
Carcinoid abdominal crisis: A case report
Authors: Jacobs Ramon E.A. , Bai Shuting , Hindman Nicole , Shah Paresh C.
Published: May 2014

Over the past 40 years, the incidence of neuroendocrine tumors (NETs) has been increasing. Distal small bowel (i.e., midgut) NETs most often cause carcinoid syndrome manifested as cutaneous flushing, diarrhea, bronchial constriction, and cardiac involvement. Carcinoid abdominal crisis occurs when submucosal tumors impede the vascular supply to the gut leading to mesenteric ischemia and worsening abdominal pain. Here, we report the case of a young woman with progressively worsening abdominal pain. J. Surg. Oncol. 2014 110:348–351. © 2014 Wiley Periodicals, Inc.
Recent Trends in U.S. Income and Expenditure Poverty
Authors: Bavier Richard
Published: May 2014

After many years of following similar trends, U.S. poverty rates measured by household spending in data from the U.S. Consumer Expenditure Survey (CE) fell between 2000 and 2008, while poverty measured by income rose. Comparisons of spending and income poverty in the CE with income poverty in other surveys, spending data from the Panel Study of Income Dynamics, and a time series of employment levels, find the CE to be the outlier. The findings do not bear directly on the primary use of CE data in providing category weights for calculation of the Consumer Price Index, but do require explanation not available in CE public‐use files.
Visualization of the distribution of anatase and rutile TiO2 crystals in Au/TiO2 powder catalysts by STEM–EELS spectrum imaging
Authors: Akita Tomoki , Kohyama Masanori
Published: May 2014

Gold nanoparticles deposited on TiO2 supports exhibit high catalytic activity for various chemical reactions such as low‐temperature CO oxidation. The catalytic performance is sensitive to the structure of the TiO2 supports, as reported in the epoxidation of propylene. TiO2 powder (P‐25), widely used as the support for metal catalysts, contains both anatase and rutile TiO2 phases. It is important to distinguish these two crystalline phases at the nanoscale in order to understand the effect of the support structure in Au/TiO2 catalysis. In this study, the two‐phase distribution is analyzed using scanning transmission microscopy–electron energy‐loss spectroscopy (STEM–EELS). The distribution is revealed through multilinear least‐squares fitting on the basis of the difference in the energy‐loss near‐edge structure. The results obtained indicate that Au particles are preferentially deposited on rutile TiO2 in the deposition/precipitation process. The STEM–EELS spectrum imaging method, with its high energy and spatial resolutions, can be employed to determine the distribution of crystal phases, components, and valence states. Copyright © 2014 John Wiley & Sons, Ltd.
Correlation between histological signs of placental underperfusion and perinatal morbidity in late‐onset small‐for‐gestational‐age fetuses
Authors: Parra‐Saavedra M. , Simeone S. , Triunfo S. , Crovetto F. , Botet F. , Nadal A. , Gratacos E. , Figueras F.
Published: May 2014

Objective

To investigate whether signs of placental underperfusion (PUP), defined as any maternal and/or fetal vascular pathology, confer an increased risk of neonatal morbidity in late‐onset small‐for‐gestational‐age (SGA) fetuses with normal umbilical artery (UA) Doppler indices.

Methods

A cohort of 126 SGA singleton fetuses with normal UA Doppler indices that were delivered after 34 weeks' gestation was studied. For each case, the placenta was evaluated histologically for signs of PUP using a hierarchical and standardized classification system. Neonatal morbidity was assessed according to the score calculated from the morbidity assessment index for newborns (MAIN), a validated outcome scale. The independent association between PUP and neonatal morbidity was evaluated using multivariable median regression analysis.

Results

In 84 (66.7%) placentae, 97 placental histological findings that qualified as signs of PUP were observed. These PUP cases had a significantly higher incidence of emergency Cesarean section for non‐reassuring fetal status (44.1% vs 21.4%, respectively; P = 0.013) and neonatal metabolic acidosis at birth (33.3% vs 14.3%, respectively; P = 0.023), than did those without PUP. The median MAIN score differed significantly between those with PUP and those without (89 vs 0, respectively; P = 0.025). This difference remained significant after adjustment for potential confounders. The proportion of cases with scores indicative of mild to severe morbidity was also significantly higher in the PUP group (31% vs 14.3%, respectively; P = 0.043).

Conclusion

In late‐onset SGA fetuses with normal UA Doppler indices, signs of PUP imply a higher neonatal morbidity. These findings allow the phenotypic profiling of fetal growth restriction among the general population of late‐onset SGA. Copyright © 2014 ISUOG. Published by John Wiley & Sons Ltd.
Mechanochemically activated waste‐derived cellulose as a novel functional additive to enhance melt processability and mechanical properties of poly(vinyl alcohol)
Authors: He Xu , Zhang Xinxing , Zhang Wei , Tian Dong , Lu Canhui
Published: May 2014

We have developed a solvent‐free mechanochemical technology to activate cellulose derived effectively from waste cotton fabrics. A self‐designed (pan‐mill)‐type mechanochemical reactor was adopted to break up the hydrogen bonds and decrease the crystallinity of cellulose through the fairly strong shearing and squeezing forces. The mechanochemically activated waste‐derived cellulose (WC) can be used as a cost‐effective functional additive to enhance the melt‐processability and mechanical properties of poly(vinyl alcohol) (PVA). With the addition of 20 phr pretreated cellulose, the melting temperature of PVA decreased sharply from its original 212.2oC to 198.1oC, whereas the maximum decomposition temperature of PVA increased from 243.8oC to 266.3oC. As a result, the melt‐processing window was remarkably expanded, which favored the performance of the melt‐processed PVA/WC composites. The tensile strength and elongation at break of the PVA/WC (100/20) composites were remarkably enhanced by 32.2% and 197.1% compared with those of untreated WC‐filled PVA composites. J. VINYL ADDIT. TECHNOL., 20:177–184, 2014. © 2014 Society of Plastics Engineers
Effects of chemical modification of epoxy‐(ethylene diamine) on water hyacinth fibers (Eichhornia crassiper)‐filled (low‐density polyethylene)/(natural rubber) blends
Authors: Supri A.G. , Tan S.J. , Teh P.L.
Published: May 2014

The effects of modification by epoxy‐(ethylene diamine) (EED) on (water hyacinth fiber)‐filled (low‐density polyethylene)/(natural rubber) (LDPE/NR/WHF‐EED) composites were studied. The LDPE/NR/WHF and LDPE/NR/WHF‐EED composites were prepared by using a Brabender Plasticorder. LDPE/NR/WHF‐EED showed higher tensile strength, Young's modulus, and elongation at break but lower molar sorption of toluene compared with LDPE/NR/WHF composites. The Fourier‐transform infrared radiation analysis indicated that the absorption peak at 1,648 cm−1 exhibited the CN band. This CN band was formed from the bond of the epoxy group and the amine group in the WHF‐g‐epoxy‐(ethylene diamine) (WHF‐EED). The scanning electron microscopic morphology of LDPE/NR/WHF‐EED composites displayed rougher surfaces and less fiber pull, which improved the interfacial adhesion among the fiber/matrix. J. VINYL ADDIT. TECHNOL., 20:201–209, 2014. © 2014 Society of Plastics Engineers
Oxygen Plasma Effects on Zero Resistance Behavior of Yb,Er‐doped YBCO (123) Based Superconductors
Authors: Schäfer Helmut , Banko Franziska , Nordmann Jörg , Voss Benjamin , Steinhart Martin , Walder Lorenz , Rathmann Dirk
Published: May 2014

Rare‐earth doped YBa2Cu3O7–δ samples were synthesized starting from the corresponding oxides Y2O3, Yb2O3, Er2O3, CuO as well as Ba(OH)2 by heating to 950 °C under air. The doping concentrations were adjusted to 15 % Yb, 7 % Er and 20 % Yb, 15 % Er, respectively, with respect to the yttrium content. The orthogonal phased (123) YBCO ceramics were exposed to an oxygen plasma for 140 and 380 min. Zero resistance temperature (Tc,0) was determined by measuring the resistivity‐temperature dependence using a classical four point measurement approach. Under optimal conditions with respect to the material composition and the oxygen treatment an unusual high zero resistance temperature of 97.5 K (Tc,onset ≈ 101 K) was achieved. This represents an increase of Tc,0 by 7.5 K. The oxygen treatment could not be monitored by IR spectroscopy, X‐ray fluorescence spectroscopy, and X‐ray powder diffraction. The results showed good reproducibility.
Frontale Hirnvolumenminderung durch Antipsychotika?
Authors: Aderhold V. , Weinmann S. , Hägele C. , Heinz A.
Published: May 2014

In dieser Übersicht werden die Ergebnisse longitudinaler Studien zur frontalen Hirnvolumenminderung bei Menschen mit einer Erkrankung aus dem Spektrum schizophrener Psychosen dargestellt und zur Behandlung mit Antipsychotika in Beziehung gesetzt. Nach einer systematischen Literaturrecherche wurden alle Studien ausgewertet, in denen an einer größeren Population Ergebnisse bildgebender Diagnostik zur Veränderung der Hirnstruktur im Langzeitverlauf mit Daten zur antipsychotischen Behandlung und zur Schwere der Erkrankung korreliert wurden. Die Ergebnisse zeigen, dass es eine Evidenz für eine Volumenminderung grauer und weißer Substanz des Frontalhirns gibt, die sich nicht alleine durch die Erkrankung selbst und ihre Krankheitsschwere erklären lässt, sondern mit hoher Wahrscheinlichkeit auch Ausdruck einer langfristigen Antipsychotikawirkung auf das Gehirn ist. Ob sog. „Second-generation“-Antipsychotika hier einen mittel- bis längerfristigen Vorteil gegenüber „First-generation“-Antipsychotika besitzen, ist derzeit unklar. Angesichts des Beitrags von Antipsychotika zu den hirnstrukturellen Veränderungen, die offenbar kumulativ dosisabhängig sind und negative Auswirkungen für die Neurokognition, die Positiv- und Negativsymptomatik und das soziale Anpassungsniveau mit sich bringen können, sollten die Empfehlungen zur antipsychotischen Langzeitbehandlung neu überdacht werden. Vor dem Hintergrund der neurobiologischen Befunde empfehlen wir und andere, möglichst niedrige antipsychotische Dosierungen zur Symptomkontrolle einzusetzen. Bei psychiatrischen Störungen außerhalb des Schizophreniespektrums sollten Antipsychotika ebenfalls nur mit Vorsicht und nach sorgfältiger Abwägung von Risiken und Nutzen angewandt werden. In diesem Kontext werden zunehmend auch Behandlungsansätze relevant, welche die antipsychotische Medikation minimieren oder sogar einen nur selektiven Einsatz erlauben.
Prevalence, Morbidity, and Mortality Patterns of Typhoid Ileal Perforation as Seen at the University of Nigeria Teaching Hospital Enugu Nigeria: An 8‐year Review
Authors: Agu Kenneth , Nzegwu Martin , Obi Emmanuel
Published: May 2014

Background

Some recent studies have reported a decrease in mortality from typhoid ileal perforation. The present report aims to determine the prevalence, morbidity, and mortality of this disease in patients mostly drawn from a rural area.

Methods

This is a retrospective study of 50 patients treated between January 1999 and December 2007 at the University of Nigeria Teaching Hospital, Enugu, Nigeria. The variables studied included patient demographics, clinical features, intraoperative findings, complications, and mortality. Statistical analysis was done with SPSS version 13.

Results

Of the 50 patients included in the study, 22 were males with the highest rate in patients aged 20 years and younger. Fever was the commonest symptom and at initial presentation, the mean pulse and respiratory rates were significantly higher in the patients who subsequently died than in those who survived (P < 0.05). All the perforations occurred in the ileum; 62 % of the patients had solitary perforations, 28 % had double perforations, and 10 % had three or more. Fifty‐eight perforations were treated by simple closure in two layers, 4 patients had ileal resection and anastomosis, and 2 underwent right hemicolectomy. The mean interval between operation and death was 1.7 days. The overall mortality rate was 30 %, but among those with three or more perforations, mortality was 100 %.

Conclusions

Typhoid ileal perforation still carries a high mortality especially in rural areas. Those with tachycardia and tachypnea at presentation and those with three or more perforations are at a higher risk of dying from the disease.
Roman Politics in the 70sb.c.: a Story of Realignments?
Authors: Santangelo Federico
Published: May 2014

This paper revisits the political history of the Roman Republic in the third decade of the first centuryb.c.Its central contention is that the dominant feature of the period was neither a reshuffle of alliances within the ‘Sullan’ senatorial nobility nor the swift demise of Sulla's legacy. Attention should be focused instead on some crucial policy issues which attracted debate and controversy in that period: the powers of the tribunes, the corn supply of Rome, the rôle of the Senate, the revival of the census, and the full inclusion of the Allies into the citizen body. The political strategy of M. Aemilius Lepidus (cos. 78b.c.) and its medium-term repercussions also deserve close scrutiny in this connection.
LEY DE ZIPF Y DE GIBRAT PARA COLOMBIA Y SUS REGIONES: 1835-2005
Authors: Pérez Valbuena Gerson Javier , Meisel Roca Adolfo
Published: May 2014

En este documento se analiza la jerarquía urbana de Colombia y sus regiones utilizando información censal de entre 1835 y 2005. Se estudian tres aspectos: 1) la distribución del tamaño poblacional a través de las regularidades empíricas de Zipf y de Gibrat; 2) el cambio en el modelo de crecimiento poblacional, y 3) la validación empírica sobre la coincidencia de la dinámica poblacional para un país y sus regiones. Haciendo uso de la relación rango-tamaño y de técnicas no paramétricas, se encuentra coincidencia nacional y regional desde 1964 del cumplimiento de la ley de Zipf y parcialmente de la ley de Gibrat, lo cual evidencia un cambio en el modelo de crecimiento poblacional desde mediados del siglo XX en los ámbitos nacional y regional.
Comparison of fatty acid composition of oil from original and regenerated populations of wildHelianthusspecies
Authors: Seiler Gerald J.
Published: May 2014

Monitoring and protecting germplasm in genebanks usingin situcollections while preserving its original genetic integrity is a priority of germplasm curation. Many germplasm accessions need to be regenerated due to their demand and/or seed condition. The regeneration of wildHelianthus(sunflower) species poses several challenges due to the diversity of 53 wild species. Fatty acid composition of sunflower oil is an important quality factor for the crop. Since oil quality is environmentally influenced, and evaluation of this trait is usually performed on oil from achenes from the original accessions of wild sunflower species, we conducted a study on 72 accessions of eight annual and four perennial taxa of wild sunflower species to compare the oil quality of the original accessions and those regenerated for genebank maintenance. The results showed that the fatty acid composition profiles of achenes from the original and regenerated accessions are not the same. It seems that selection for specific fatty acids in several species will require the analysis of both populations to identify germplasm accessions for use in breeding programmes. It should be borne in mind that accessions of wild species are open-pollinated segregating populations, so one would expect some variability in each succeeding generation. While there may be differences between the original and regenerated accessions, the interrelationships of fatty acids are generally similar in wild and cultivated sunflower species, so there should be no detrimental effects on oil quality when using the wild species for other traits. As more regenerated accessions become available, a more precise relationship between the original and regenerated accessions should emerge.
A ‘most imperial’ contribution: New Zealand and the old age pensions debate in Britain, 1898–1912
Authors: Rogers Edmund
Published: May 2014

The extent of imperial influences upon nineteenth- and early twentieth-century British life, including in the development of social policy, has attracted significant scholarly interest in the past decade. The bearing of New Zealand's 1898 Old-Age Pensions Act upon the British debate over elderly poverty exemplifies the contested transfer of social policy ideas from settler colony to ‘Mother Country’. Reformers in Britain hailed a model non-contributory pension system with an imperial pedigree. However, the widely acknowledged distinction between ‘old’ countries such as Britain, and ‘new’ countries of English-speaking settlement, characterized the New Zealand example's reception. While progressives identified the colony as a ‘clean slate’ lacking the obstructive historical inheritance of the Poor Law, critics of state-funded pensions warned against drawing policy-making lessons from New Zealand. Yet when a reformist Liberal government introduced an Old Age Pensions Bill in 1908, it used Britain's age to justify the legislation's relative conservatism.
The economics of social reform across borders: Fukuda's welfare economic studies in international perspective
Authors: Nishizawa Tamotsu
Published: May 2014

This article examines how, in the course of modernization, Japan learned from Germany and Britain about ideas and institutions concerning social reform, and attempted to implement and develop them at home. It focuses on Fukuda Tokuzo, a pioneering liberal economist and social reformer, who studied under the German historical economist Lujo Brentano, and who was also inspired by the British scholars Alfred Marshall, A. C. Pigou, and J. A. Hobson. By examining how Fukuda's ideas and work were developed and assimilated in Japan, this article shows how Japanese social reformers navigated the two key strands of economic thinking that witnessed a process of globalization during this period: neoclassical welfare economics, on the one hand, and an ethical-historical style of economics, on the other. It shows how the latter was stronger in a latecomer country to modernization such as Japan.
PHF8 and REST/NRSF co-occupy gene promoters to regulate proximal gene expression
Authors: Wang Juan , Lin Xueqiu , Wang Su , Wang Chenfei , Wang Qixuan , Duan Xikun , Lu Peng , Wang Qian , Wang Chengyang , Liu X. Shirley , Huang Jinyan
Published: May 2014

Chromatin regulators play an important role in the development of human diseases. In this study, we focused on Plant Homeo Domain Finger protein 8 (PHF8), a chromatin regulator that has attracted special concern recently. PHF8 is a histone lysine demethylase ubiquitously expressed in nuclei. Mutations of PHF8 are associated with X-linked mental retardation. It usually functions as a transcriptional co-activator by associating with H3K4me3 and RNA polymerase II. We found that PHF8 may associate with another regulator, REST/NRSF, predominately at promoter regions via studying several published PHF8 chromatin immunoprecipitation-sequencing (ChIP-Seq) datasets. Our analysis suggested that PHF8 not only activates but may also repress gene expression.
A rapid and simple method to assess the changes of human VEGF mRNA based on dual molecular beacons
Authors: Liu Bin , Wang Wei , Li Chen , Tong Chunyi , Long Ying
Published: May 2014

A fluorescence method with wide promising applications was developed for VEGF mRNA assay with high accuracy and specificity by applying dual molecular beacons as probes.
The role of site-directed point mutations in protein misfolding
Authors: Baruah Anupaul , Biswas Parbati
Published: May 2014

Mutations inducing higher clashing and lower matching residue pairs lead to misfolding.
Evolution of epitaxial semiconductor nanodots and nanowires from supersaturated wetting layers
Authors: Zhang Jianjun , Brehm Moritz , Grydlik Martyna , Schmidt Oliver G.
Published: May 2014

We highlight the key role of supersaturated, planar epitaxial layers in the formation of highly homogeneously-sized nanodots, perfectly ordered nanodots and nanodot-molecules, and nanowires.
Marine natural products-inspired phenylmethylene hydantoins with potent in vitro and in vivo antitumor activities via suppression of Brk and FAK signaling
Authors: Sallam Asmaa A. , Mohyeldin Mohamed M. , Foudah Ahmed I. , Akl Mohamed R. , Nazzal Sami , Meyer Sharon A. , Liu Yong-Yu , El Sayed Khalid A.
Published: May 2014

The synthetic marine-inspired PMH analog7showed promisingin vitroandin vivoantitumor effects against breast cancerviatargeting Brk and FAK signaling pathways.
Novel metallo-dendrimers containing various Ru core ligands and dendritic thiophene arms for photovoltaic applications
Authors: Satapathy Rudrakanta , Ramesh Mohan , Padhy Harihara , Chiang I.-Hung , Chu Chih-Wei , Wei Kung-Hwa , Lin Hong-Cheu
Published: May 2014

A polymer solar cell device containing an active layer of BTRu2G3 : PC70BM = 1 : 3 (by wt), i.e., the third generation of the bis-Ru-based dendritic complex BTRu2G3 showed the highest PCE value of 0.77%.
Design, characterization and application of a novel mono-layer pin-microvalve for microfluidic devices
Authors: Nasabi Mahyar , Tehranirokh Masoomeh , Tovar-Lopez Francisco Javier , Kouzani Abbas , Khoshmanesh Khashayar , Mitchell Arnan
Published: May 2014

We introduce a novel manual pin-valve which can operate in both analogue (partially close) and digital (on/off) states. We also demonstrate implementation of this pin-valve in a hydrodynamic flow focusing (HFF) device.
Penicillium expansum lipase-coated magnetic Fe3O4–polymer hybrid hollow nanoparticles: a highly recoverable and magnetically separable catalyst for the synthesis of 1,3-dibutylurea
Authors: Liu Jun , Wang Wenjing , Liu Huiwen , Zhou Yaoliang , Zhang Haibo , Zhou Xiaohai
Published: May 2014

Amino-epoxy supports were innovatively imported onto magnetic nanoparticles for immobilizing enzyme which represents a novel class of heterogeneous catalyst for the synthesis of 1,3-dibutylurea from ethylene carbonate and butylamine.
IrOx core-shell nanocatalysts for cost- and energy-efficient electrochemical water splitting
Authors: Nong Hong Nhan , Gan Lin , Willinger Elena , Teschner Detre , Strasser Peter
Published: May 2014

A family of dealloyed metal–oxide hybrid (M1M2@M1Ox) core@shell nanoparticle catalysts is demonstrated to provide substantial advances toward more efficient and less expensive electrolytic water splitting.
Hydrodynamic interactions slow down crystallization of soft colloids
Authors: Roehm Dominic , Kesselheim Stefan , Arnold Axel
Published: May 2014

We performed MD simulations of heterogeneous crystallization of soft colloids focusing on the effect of hydrodynamic interactions. We found that particle attachment is not purely diffusive as commonly assumed.
The role of Helicobacter pylori urease in the pathogenesis of gastritis and peptic ulceration.
Authors: Mobley HL
Published: May 2014

Helicobacter pylori produces a 550 kDa, multimeric, nickel‐containing urease that catalyses the hydrolysis of urea to yield ammonia and carbonic acid. The ure gene cluster, comprised of seven genes, encodes the two structural subunits UreA (26.5 kDa) and UreB (60.3 kDa), and five accessory proteins: UreI, UreE, UreF, UreG and UreH. Accessory proteins are required for nickel ion insertion into the apoenzyme. The native protein consists of six copies each of UreA and UreB; two nickel ions are coordinated into each UreB active site. Urease is found in the cytosol, but may also localize on the surface (although this may be an artefact) and elicits a strong serum immunoglobulin response. Urease aids in colonization of the host by neutralizing gastric acid and providing ammonia for bacterial protein synthesis. Host defences are avoided by urease by continuing to neutralize acid locally and by shedding urease, which may be bound by immunoglobulin, from the surface of the bacterium. Host tissues can be damaged directly by the urease‐ mediated generation of ammonia and indirectly by urease‐induced stimulation of the inflammatory response, including recruitment of leukocytes and triggering of the oxidative burst in neutrophils.
Gastrin and acid in relation to Helicobacter pylori.
Authors: Peterson WL
Published: May 2014

H. pylori infection, both in normal healthy subjects and patients with duodenal ulcer, results in modest elevations of serum gastrin concentrations in the fasting state and quite substantial elevations after a meal or gastrin releasing peptide (GRP) stimulation. Cure of the infection leads to normalization of gastrin homeostasis. Acid secretion in response to a submaximal infusion of GRP is three‐fold higher in H. pylori‐infected normal subjects and six‐fold higher in DU patients than in non‐infected controls. These changes also normalize after cure of the infection. H. pylori infection appears to lead to increased basal acid output in some patients with duodenal ulcer while effects on peak acid output to pentagastrin remain under debate. With the possible exception of peak acid output, the abnormalities of gastrin and acid secretion reported for patients with duodenal ulcer are largely a result of infection with H. pylori.
Impact ionization of excitons in Ge/Si structures with Ge quantum dots grown on the oxidized Si(100) surfaces
Authors: Shklyaev A. A. , Shegai O. A. , Nakamura Y. , Ichikawa M.
Published: May 2014

Photoconductivity (PC) of Si/Ge structures with Ge quantum dots (QDs) grown on the Si(100) surfaces covered with the ultrathin, about 0.3–0.5 nm thick, SiO2 films is studied as a function of the interband light intensity under various lateral voltages. The structures exhibit PC with steps and a step with a peak at the step edge for low- and high-temperature grown structures, respectively. These PC features are associated with the impact ionization of QD-related excitons. The PC at step edges increases by several orders of magnitude for a certain value which is governed by the balance between rates of photo-generation, recombination, and impact ionization of excitons. The electron localization deeper in Si from the Ge QD layer in conjunction with a narrow binding-energy distribution of excitons is suggested to be the main reason that provides the sharpness of PC steps. The PC appears to be very sensitive to the impact ionization and QD preparation conditions. This allows revealing the specific characteristics of QD structures, related to their electronic and structural properties.
Analytic energy gradient for the projected Hartree–Fock method
Authors: Schutski Roman , Jiménez-Hoyos Carlos A. , Scuseria Gustavo E.
Published: May 2014

We derive and implement the analytic energy gradient for the symmetry Projected Hartree–Fock (PHF) method avoiding the solution of coupled-perturbed HF-like equations, as in the regular unprojected method. Our formalism therefore has mean-field computational scaling and cost, despite the elaborate multi-reference character of the PHF wave function. As benchmark examples, we here apply our gradient implementation to the ortho-, meta-, and para-benzyne biradicals, and discuss their equilibrium geometries and vibrational frequencies.
On the solvability of the generalized hyperbolic double-well models
Authors: Agboola Davids
Published: May 2014

We present exact solutions for the Schrödinger equation with the hyperbolic double-well potential \documentclass[12pt]{minimal}\begin{document}$V_{q}^p(x)=-V_0{\sinh ^p(\alpha x)}/{\cosh ^{q}(\alpha x)}$\end{document}Vqp(x)=−V0sinhp(αx)/coshq(αx). We show that the model preserves a finite dimensional polynomial space for some p and q. Thus using the Bethe ansatz method, we obtain closed form expressions for the spectrum and wavefunction, as well as the allowed parameter for the class \documentclass[12pt]{minimal}\begin{document}$V^p_6(x)$\end{document}V6p(x), which is contrary to a report in a recent article [C. A. Downing, J. Math. Phys. 54, 072101 (2013)]. We also discuss the hidden sl2 algebraic structure of the class.
Maximal Cherenkov γ-radiation on Fermi-surface of compact stars
Authors: Akbari-Moghanjoughi M.
Published: May 2014

The quantum magnetohydrodynamic model is employed in this paper to study the extraordinary (XO) elliptically polarized electromagnetic wave dispersion in quantum plasmas with spin-1/2 magnetization and relativistic degeneracy effects, considering also the electron-exchange and quantum diffraction of electrons. From the lower and upper calculated XO-modes, it is observed that, for electrons on the surface of the Fermi-sphere, the lower XO-mode can excite the Cherenkov radiation by crossing the Fermi-line, with some proper conditions depending on the values of independent plasma parameters, such as the relativistic-degeneracy, the atomic-number of constituent ions, and the magnetic field strength. Particularly, a lower electron number-density and Cherenkov radiation frequency limits are found to exist, for instance, for given values of the plasma ions atomic-number and the magnetic field strength below which the radiation can not be excited by the electrons on the Fermi-surface. This lower density limit increases by decrease in the atomic-number but decreases with decrease in the strength of the ambient magnetic field. It is remarkable that in this research it is discovered that the maximal Cherenkov-radiation per unit-length (the energy radiated by superluminal electrons traveling through the dielectric medium) coincides with the plasma number-densities, which is present in compact stars with the maximal radiation frequency lying in the gamma-ray spectrum. Current study can provide an important plasma diagnostic tool for a wide plasma density range, be it the solid density, the warm dense matter, the inertial confined or the astrophysical compact plasmas and may reveal an important cooling mechanism for white dwarfs. Current findings may also answer the fundamental astrophysical question on the mysterious origin of intense cosmic gamma-ray emissions.
The Hubble expansion is isotropic in the epoch of dark energy
Authors: Darling Jeremy
Published: May 2014

The isotropy of the universal Hubble expansion is a fundamental tenet of physical cosmology, but it has not been precisely tested during the current epoch, when dark energy is dominant. Anisotropic expansion will produce a shearing velocity field, causing objects to stream towards directions of faster expansion and away from directions of slower expansion. This work tests the basic cosmological assumption of isotropic expansion and thus the isotropy of dark energy. The simplest anisotropy will manifest as a quadrupolar curl-free proper motion vector field. We derive this theoretical signature using a triaxial expanding metric with a flat geometry (Bianchi I model), generalizing and correcting previous work. We then employ the best current data, the Titov & Lambert proper motion catalogue of 429 objects, to measure the isotropy of universal expansion. We demonstrate that the Hubble expansion is isotropic to 7 per cent (1σ), corresponding to streaming motions of 1 μas yr−1, in the best-constrained directions (−19 and +17 per cent in the least-constrained directions) and does not significantly deviate from isotropy in any direction. The Gaia mission, which is expected to obtain proper motions for 500 000 quasars, will likely constrain the anisotropy below 1 per cent.
Structural elements in the Gag polyprotein of feline immunodeficiency virus involved in Gag self-association and assembly
Authors: Abdusetir Cerfoglio Juan C. , González Silvia A. , Affranchino José L.
Published: May 2014

The Gag polyprotein of feline immunodeficiency virus (FIV) assembles at the plasma membrane of the infected cells. We aimed to identify the FIV Gag domains that interact and promote Gag multimerization. To do this we generated a series of Gag subdomains and tested their ability to associate with full-length Gag and be recruited into extracellular virus-like particles (VLPs). Removal of 37 residues from the C-terminus of FIV Gag and deletion of the N-terminal and central regions of the nucleocapsid (NC) domain attenuated but did not abrogate association with wild-type Gag, whereas a Gag mutant protein encompassing the matrix (MA) and capsid (CA) domains interacted poorly with full-length Gag. Association with wild-type Gag was abolished by deleting most of the NC together with the N-terminal 40 residues of the MA, which most likely reflects the inability of this Gag mutant to bind RNA. Notably, the CA–NC Gag subdomain both associated with wild-type Gag and was recruited into particles in a proportion close to 50 % of the total Gag-related protein mass of VLPs. Moreover, both a Gag protein lacking the C-terminal p2 peptide and a nonmyristoylated version of the polyprotein exhibited a transdominant-negative effect on the assembly of wild-type Gag. Analysis of Gag mutants carrying internal deletions within the CA revealed that the N-terminal and the C-terminal domains of the CA are necessary for Gag assembly. Our results demonstrate that the FIV CA–NC region constitutes the principal self-interaction domain of Gag and that the RNA-binding capacity of Gag is necessary for its multimerization.
The robustness of seismic moment and magnitudes estimated using spectral analysis
Authors: Stork A.L. , Verdon J.P. , Kendall J.‐M.
Published: May 2014

We present an assessment of how microseismic moment magnitude, , estimates vary with the method and parameters used to calculate seismic moment. This is an important topic for operators and regulators who require good magnitude estimates when monitoring induced seismicity. It is therefore imperative that these parties know and understand what errors exist in given magnitude values, something that is poorly reported. This study concentrates on spectral analysis techniques and compares computed in the time and frequency domains. Using recordings of events at Cotton Valley, east Texas, the maximum discrepancy between estimated using the different methods is 0.6 units, a significant variation. By adjusting parameters in the calculation we find that the radiation pattern correction term can have the most significant effect on , generally up to 0.8 units. Following this investigation we make a series of recommendations for estimating microseismic using spectral methods. Noise should be estimated and removed from recordings and an attenuation correction should be applied. The spectral level can be measured by spectral fitting or taken from the low frequency level. Significant factors in obtaining reliable microseismic estimates include using at least four receivers recording at ⩾1000 Hz and making radiation pattern corrections based on focal mechanism solutions, not average values.