bluuebunny/crossref_metadata_2025_split huggingface dataset:
Phytochemical Diversity of the Essential Oils of Mexican Oregano (Lippia graveolensKunth) Populations along an Edapho‐Climatic Gradient
Authors: Calvo‐Irabién Luz María , Parra‐Tabla Victor , Acosta‐Arriola Violeta , Escalante‐Erosa Fabiola , Díaz‐Vera Luciana , Dzib Gabriel R. , Peña‐Rodríguez Luis Manuel 
Published: July 2014

AbstractMexican oregano (Lippia graveolens) is an important aromatic plant, mainly used as flavoring and usually harvested from non‐cultivated populations. Mexican oregano essential oil showed important variation in the essential‐oil yield and composition. The composition of the essential oils extracted by hydrodistillation from 14 wild populations of L. graveolens growing along an edaphoclimatic gradient was evaluated. Characterization of the oils by GC‐FID and GC/MS analyses allowed the identification of 70 components, which accounted for 89–99% of the total oil composition. Principal component and hierarchical cluster analyses divided the essential oils into three distinct groups with contrasting oil compositions, viz., two phenolic chemotypes, with either carvacrol (C) or thymol (T) as dominant compounds (contents >75% of the total oil composition), and a non‐phenolic chemotype (S) dominated by oxygenated sesquiterpenes. While Chemotype C was associated with semi‐arid climate and shallower and rockier soils, Chemotype T was found for plants growing under less arid conditions and in deeper soils. The plants showing Chemotype S were more abundant in subhumid climate. High‐oil‐yield individuals (>3%) were identified, which additionally presented high percentages of either carvacrol or thymol; these individuals are of interest, as they could be used as parental material for scientific and commercial breeding programs.
Pseudomonas aeruginosa Biofilm Growth Inhibition on Medical Plastic Materials by Immobilized Esterases and Acylase
Authors: Kisch Johannes Martin , Utpatel Christian , Hilterhaus Lutz , Streit Wolfgang R. , Liese Andreas 
Published: July 2014

AbstractBiofilms are matrix‐encapsulated cell aggregates that cause problems in technical and health‐related areas; for example, 65 % of all human infections are biofilm associated. This is mainly due to their ameliorated resistance against antimicrobials and immune systems. Pseudomonas aeruginosa, a biofilm‐forming organism, is commonly responsible for nosocomial infections. Biofilm development is partly mediated by signal molecules, such as acyl‐homoserine lactones (AHLs) in Gram‐negative bacteria. We applied horse liver esterase, porcine kidney acylase, and porcine liver esterase; these can hydrolyze AHLs, thereby inhibiting biofilm formation. As biofilm infections are often related to foreign material introduced into the human body, we immobilized the enzymes on medical plastic materials. Biofilm formation was quantified by Crystal Violet staining and confocal laser scanning microscopy, revealing up to 97 % (on silicone), 54 % (on polyvinyl chloride), and 77 % (on polyurethane) reduced biomass after 68 h growth.
Drug Encapsulation and Release by Mesoporous Silica Nanoparticles: The Effect of Surface Functional Groups
Authors: Tan Si Yu , Ang Chung Yen , Li Peizhou , Yap Qi Ming , Zhao Yanli 
Published: July 2014

AbstractMesoporous silica nanoparticles (MSNPs) have been widely used as drug carriers for stimuli‐responsive drug delivery. Herein, a catalysis screening technique was adopted for analyzing the effects of chain length, terminal group, and density of disulfide‐appended functional ligands on the surface of MSNPs on drug‐loading capacity and glutathione‐triggered drug‐release kinetics. The ligand with an intermediate length (5 carbon atoms) and a bulky terminal group (cyclohexyl) that complexes with theβ‐cyclodextrin ring showed the highest drug loading capacity as well as good release kinetics. In addition, decreasing the surface coverage of the functional ligands led to an enhancement in drug release. In vitro drug‐delivery experiments on a melanoma cell line (B16‐F10) by using the functionalized MSNPs further supported the conclusion. The results obtained may serve as a general guide for developing more effective MSNP systems for drug delivery.
Thermodynamic Properties of the Isomers of [HNOS], [HNO2S], and [HNOS2] and the Role of the Central Sulfur
Authors: Méndez Mariano , Francisco Joseph S. , Dixon David A. 
Published: July 2014

AbstractSimple hydrides of compounds containing N, S, and O are of significant interest due to the role that they play in atmospheric chemistry and in biological pathways. There is a lack of quantitative thermodynamic data on these compounds. We have used a reliable computational chemistry approach based on valence CCSD(T) calculations extrapolated to the complete basis set limit with additional corrections to predict the heats of formation and bond dissociation energies of such compounds. The results show that compounds with the ability of the central S atom to effectively expand its valency leads to more stable isomers and, as a consequence, that those with the NSO structural motif are thermochemically more stable than those with the SNO motif. In addition, SO bonds are preferred over NO bonds.
Kinetics and Thermodynamic Studies of Oxytetracycline Mineralization Using UV/H2O2
Authors: Rahmah Anisa Ur , Harimurti Sabtanti , Omar Abdul Aziz , Murugesan Thanapalan 
Published: July 2014

AbstractOxytetracycline (OTC), a widely used antibiotic, was taken as the model contaminant to study the kinetic and thermodynamic parameters of mineralization using a UV/H2O2 system. Mineralization experiments were carried out at different initial OTC concentrations of 0.0156–0.0531 M, initial H2O2 concentrations of 0.043–0.116 M and at a temperature range of 20 − 50°C. The OTC mineralization process was monitored by measuring the total organic carbon as well as H2O2 consumption. The analysis of mineralization data showed two phases of mineralization: phase I: 0 ≤ t ≤ 30 min and phase II: 30 ≤ t ≤ 180 min. Based on this, the kinetic and thermodynamic parameters were established. The order of reaction obtained for organic C and H2O2 is 0.624 and 0.599 (phase I) and 0.954 and 0.062 (phase II), respectively. Based on this kinetic model, the OTC degradation rate constants were 0.0069 min−1 (phase I) and 0.0051 min−1 (phase II). The activation energy for phase I and phase II oxidation was 10.236 and 9.913 kJ mol−1, respectively. The estimated Δ#G and Δ#H values are positive, whereas negative Δ#S values were obtained.
Effects of Nitrogen Pollution on Periphyton Distribution, Elemental Composition and Assemblage Shifts in River Ecosystems
Authors: Tang Wenzhong , Shan Baoqing , Cui Jingguo , Zhao Yu , Zhang Wenqiang 
Published: July 2014

AbstractEcological stoichiometry (ES) can provide a good insight and predictive power for environmental research. For some years, it has been suggested that ES should be used in river ecosystem studies. This study applied this method to a river system of Hai River Basin (HRB), to identify which pollutants affect periphyton distribution and how pollutants affect periphyton stoichiometry. In rivers with different levels of nitrogen (N) pollution, periphyton could be classified into three groups based on typologies as follows: attached diatoms (AD), filamentous algae (FA), and filamentous algae with epiphyte (FE). AD represented clean ambient water, FE indicated slight pollution, and FA showed that water had been contaminated by N. Ammonium nitrogen (NH4+‐N) was the main factor of periphyton distribution and assemblage shifts. The carbon/N ratio differed significantly between the groups, and values were 14 for AD, 12 for FE, and ten for FA. The N/phosphorus (P) ratios for AD, FE, and FA were 47, 24, and 19, respectively. NH4+‐N and total P (TP) controlled the N/P ratio of AD, NOx–‐N (nitrite and nitrate–nitrogen) controlled the N/P ratio of FE and TP controlled the N/P ratio of FA. Based on the changes observed in periphyton assemblages in the HRB, managing and controlling N pollution in freshwater, especially from NH4+‐N, should be prioritized.
Synthesis of Potassium‐Modified Graphitic Carbon Nitride with High Photocatalytic Activity for Hydrogen Evolution
Authors: Wu Ming , Yan Jun‐Min , Tang Xian‐nian , Zhao Ming , Jiang Qing 
Published: July 2014

AbstractPotassium‐modified graphitic carbon nitride (K‐g‐C3N4) nanosheets are synthesized by a facile KCl‐template method that holds the advantage of easy removal of residual template. A combination of XRD, X‐ray photoelectron spectroscopy, and inductively coupled plasma analyses are utilized to characterize the obtained resultant K‐g‐C3N4 architectures, which are composed of nanosheets of variable thickness (<10 nm). Photocatalytic hydrogen evolution experiments under visible light irradiation showed that K‐g‐C3N4 nanosheets have high photocatalytic activities (up to about thirteen times higher than that of pure g‐C3N4) as well as good stability (no reduction in activity within 16 h); both features emanate from their unique structural characteristics. These results illustrate the viability of this methodology for the facile synthesis of efficient heterogeneous photocatalysts for potential commercial applications.
Characterization of missense alleles of the glial cells missing Gene of Drosophila
Authors: Jones Bradley W. 
Published: July 2014

SummaryGlial cells missing (Gcm) is the primary regulator of glial cell fate in Drosophila. Gcm belongs to a small family of transcriptional regulators involved in fundamental developmental processes found in diverse animal phyla including vertebrates. Gcm proteins contain the highly conserved DNA‐binding GCM domain, which recognizes an octamer DNA sequence. To date, studies in Drosophila have primarily relied on gcm alleles caused by P‐element induced DNA deletions at the gcm locus, as well as a null allele caused by a single base pair substitution in the GCM domain that completely abolishes DNA binding. Here I characterize two hypomorphic missense alleles of gcm with intermediate glial cells missing phenotypes. In embryos homozygous for either of these gcm alleles the number of glial cells in the central nervous cystem (CNS) is reduced approximately in half. Both alleles have single amino acid changes in the GCM domain. These results suggest that Gcm protein activities in these mutant alleles have been attenuated such that they are operating at threshold levels, and trigger glial cell differentiation in neural precursors in the CNS in a stochastic fashion. These hypomorphic alleles provide additional genetic resources for understanding Gcm functions and structure in Drosophila and other species. genesis 52:864–869, 2014. © 2014 Wiley Periodicals, Inc.
Survival relative to new and ancestral host plants, phytoplasma infection, and genetic constitution in host races of a polyphagous insect disease vector
Authors: Maixner Michael , Albert Andreas , Johannesen Jes 
Published: July 2014

AbstractDissemination of vectorborne diseases depends strongly on the vector's host range and the pathogen's reservoir range. Because vectors interact with pathogens, the direction and strength of a vector's host shift is vital for understanding epidemiology and is embedded in the framework of ecological specialization. This study investigates survival in host‐race evolution of a polyphagous insect disease vector, Hyalesthes obsoletus, whether survival is related to the direction of the host shift (from field bindweed to stinging nettle), the interaction with plant‐specific strains of obligate vectored pathogens/symbionts (stolbur phytoplasma), and whether survival is related to genetic differentiation between the host races. We used a twice repeated, identical nested experimental design to study survival of the vector on alternative hosts and relative to infection status. Survival was tested with Kaplan–Meier analyses, while genetic differentiation between vector populations was quantified with microsatellite allele frequencies. We found significant direct effects of host plant (reduced survival on wrong hosts) and sex (males survive longer than females) in both host races and relative effects of host (nettle animals more affected than bindweed animals) and sex (males more affected than females). Survival of bindweed animals was significantly higher on symptomatic than nonsymptomatic field bindweed, but in the second experiment only. Infection potentially had a positive effect on survival in nettle animals but due to low infection rates the results remain suggestive. Genetic differentiation was not related to survival. Greater negative plant‐transfer effect but no negative effect of stolbur in the derived host race suggests preadaptation to the new pathogen/symbiont strain before strong diversifying selection during the specialization process. Physiological maladaptation or failure to accept the ancestral plant will have similar consequences, namely positive assortative mating within host races and a reduction in the likelihood of oviposition on the alternative plant and thus the acquisition of alternative stolbur strains.
High‐Efficiency Motors Using Soft Magnetic Cores
Authors: Tokoi Hirooki , Kawamata Shoichi , Enomoto Yuji 
Published: July 2014

SUMMARYWe have developed a small and highly efficient axial gap motor whose stator core consists of a soft magnetic core. First, the loss sensitivities to various motor design parameters were evaluated by magnetic field analysis. Low sensitivity to the pole number and core dimensions ( ⩽ 2.2 dB) was found for the total loss, which is the sum of the copper loss and the iron losses in the stator core and the rotor yoke. From this we concluded that to improve the motor efficiency, it is essential to reduce the iron loss in the rotor yoke and to minimize the other losses. With this in mind, a prototype axial gap motor was manufactured and tested. The motor has four poles and six slots. The motor is 123 mm in diameter and the axial length is 47 mm. The rotor has parallel magnetized magnets and a rotor yoke with magnetic steel sheets. The maximum measured rotor efficiency is 93%. This value roughly agrees with the maximum calculated efficiency of 95%.
Synthesis, Characterization, Magnetic and Catalytic Properties of a Ladder‐Shaped MnII Coordination Polymer
Authors: Lymperopoulou Smaragda , Papastergiou Maria , Louloudi Maria , Raptopoulou Catherine P. , Psycharis Vassilis , Milios Constantinos J. , Plakatouras John C. 
Published: July 2014

Abstract[Mn(LH)(H2O)]n {1, where LH2– is the dianion of N‐(4‐carboxybenzyl)iminodiacetic acid} has been synthesized and its crystal structure has been determined. The crystal of 1 is built from 1D polymeric ladder‐shaped chains that extend to a 3D supramolecular architecture through H‐bonds. The compound was characterized with spectroscopic and physicochemical techniques. Variable‐temperature magnetic data suggest that there are weak antiferromagnetic interactions. Compound 1 has been evaluated as a heterogeneous oxidation catalyst. It catalyzes alkene epoxidation selectively in relatively high yields.
Elucidating the Origin of Enhanced Phosphorescence Emission in the Solid State (EPESS) in Cyclometallated Iridium Complexes
Authors: Howarth Ashlee J. , Patia Raissa , Davies David L. , Lelj Francesco , Wolf Michael O. , Singh Kuldip 
Published: July 2014

AbstractA new mechanism for enhanced phosphorescence emission in the solid state (EPESS) in cyclometallated Ir complexes with the general formula [Ir(CN)2(NO)] involving distortion of the six‐membered chelate ring of the ancillary ligand is proposed. Photophysical and computational studies show that neither π‐stacking nor restricted rotation cause the observed EPESS in these complexes and that ligand distortions in the triplet excited state are responsible for EPESS
Antinociceptive activity of the new triple reuptake inhibitor NS18283 in a mouse model of chemotherapy‐induced neuropathic pain
Authors: Hache G. , Guiard B.P. , Nguyen T.H. , Quesseveur G. , Gardier A.M. , Peters D. , Munro G. , Coudoré F. 
Published: July 2014

AbstractBackgroundChronic neuropathic pain can lead to anxiety and depression. Drugs that block reuptake of serotonin, norepinephrine and/or dopamine are widely used to treat depression, and have emerged as useful drugs in the treatment of neuropathic pain. This study compared the acute antinociceptive effects of NS18283, a novel triple monoamine reuptake inhibitor (MRI) with indatraline, venlafaxine and escitalopram in a mouse model of neuropathic pain.MethodNeuropathic pain‐like behaviours were induced in mice by repeated injections of oxaliplatin (OXA), and assessed using the von Frey hair test, the cold plate test and the thermal preference plate test. Anxio/depressive phenotype and antidepressant‐like properties of compounds were assessed by the novelty suppressed feeding test and the tail suspension test, respectively.ResultsIn vivo microdialysis experiments showed that each MRI increased extracellular serotonin, norepinephrine and/or dopamine levels in the cingulate cortex, in agreement with their in vitro reuptake inhibitory properties. Indatraline (3 mg/kg) reversed the full repertoire of OXA‐induced neuropathic hypersensitivity. NS18283 (10 mg/kg) reversed OXA‐induced mechano‐hypersensitivity and cold allodynia. Venlafaxine (16 mg/kg) and escitalopram (4 mg/kg) only reversed cold allodynia and mechano‐hypersensitivity, respectively. All MRIs produced antidepressant‐like activity in anxio/depressive phenotype of OXA mice.ConclusionsAcute administration of drugs that enhance the activity of serotonin, norepinephrine and dopamine neurotransmission within nociceptive pathways may provide a broader spectrum of antinociception than dual or selective reuptake inhibitors in animal models of neuropathic pain. Whether similar observations would occur after repeated administration of such compounds in an attempt to simulate dosing in humans, or be compromised by dopaminergic‐mediated adverse effects warrants further investigation.
Displacement amplification factors for steel eccentrically braced frames
Authors: Kuşy𝚤lmaz Ahmet , Topkaya Cem 
Published: July 2014

SummaryInelastic deformation capacity of links is a factor that significantly influences design of steel eccentrically braced frames (EBFs). The link rotation angle is used to describe inelastic link deformation. The link rotation angle is generally calculated by making use of design story drifts that in turn are calculated by modifying the elastic displacements by a displacement amplification factor. This paper presents a numerical study undertaken to evaluate the displacement amplification factor given in ASCE7‐10 for EBFs and the rigid‐plastic mechanism used for calculating link rotation angles. A total of 72 EBFs were designed by considering the number of stories, the bay width, the link length to bay width ratio, and the seismic hazard level as the prime variables. All structures were analyzed using elastic and inelastic time history analyses. The results indicated that the displacement amplification factor given in ASCE7‐10 provides unconservative estimates of the story drifts. On the other hand, the rigid‐plastic mechanism provides conservative estimates of link rotations. Based on the results of the numerical study, a new set of displacement amplification factors that vary along the height of the structure and modifications to the rigid‐plastic mechanism were developed. In light of the proposed modifications, the EBFs were redesigned and analyzed using inelastic time history analysis. The results indicated that the proposed modifications provide improvements for the displacement amplification factor and link rotation angle calculation procedures. Copyright © 2014 John Wiley & Sons, Ltd.
Acute sensitivity of white sturgeon (Acipenser transmontanus) and rainbow trout (Oncorhynchus mykiss) to copper, cadmium, or zinc in water-only laboratory exposures
Authors: Calfee Robin D. , Little Edward E. , Puglis Holly J. , Scott Erinn , Brumbaugh William G. , Mebane Christopher A. 
Published: July 2014

Abstract

The acute toxicity of cadmium, copper, and zinc to white sturgeon (Acipenser transmontanus) and rainbow trout (Oncorhynchus mykiss) were determined for 7 developmental life stages in flow-through water-only exposures. Metal toxicity varied by species and by life stage. Rainbow trout were more sensitive to cadmium than white sturgeon across all life stages, with median effect concentrations (hardness-normalized EC50s) ranging from 1.47 µg Cd/L to 2.62 µg Cd/L with sensitivity remaining consistent during later stages of development. Rainbow trout at 46 d posthatch (dph) ranked at the 2nd percentile of a compiled database for Cd species sensitivity distribution with an EC50 of 1.46 µg Cd/L and 72 dph sturgeon ranked at the 19th percentile (EC50 of 3.02 µg Cd/L). White sturgeon were more sensitive to copper than rainbow trout in 5 of the 7 life stages tested with biotic ligand model (BLM)-normalized EC50s ranging from 1.51 µg Cu/L to 21.9 µg Cu/L. In turn, rainbow trout at 74 dph and 95 dph were more sensitive to copper than white sturgeon at 72 dph and 89 dph, indicating sturgeon become more tolerant in older life stages, whereas older trout become more sensitive to copper exposure. White sturgeon at 2 dph, 16 dph, and 30 dph ranked in the lower percentiles of a compiled database for copper species sensitivity distribution, ranking at the 3rd (2 dph), 5th (16 dph), and 10th (30 dph) percentiles. White sturgeon were more sensitive to zinc than rainbow trout for 1 out of 7 life stages tested (2 dph with an biotic ligand model–normalized EC50 of 209 µg Zn/L) and ranked in the 1st percentile of a compiled database for zinc species sensitivity distribution. Environ Toxicol Chem 2014;33:2259–2272. © 2014. The Authors. This article is a US government work and, as such, is in the public domain in the United States of America. Environmental Toxicology and Chemistry published byWiley Periodicals, Inc. on behalf of SETAC. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.
A New Procedure for the Synthesis of Optically Active t‐Butylphenylphosphinothioic Acid
Authors: Drabowicz Józef , Pokora‐Sobczak Patrycja , Zając Adrian , Wach‐Panfiłow Paulina 
Published: July 2014

ABSTRACTA new procedure for the synthesis of optically active t‐butylophenylphosphinothioic acid as an enantiomerically pure dextrorotatory enantiomer having the absolute configuration (R), by a reaction of the racemate of secondary t‐butylphenylphosphine oxide with elemental sulfur in the presence of a molar equivalent of the levorotatory enantiomer of enantiomerically pure (S)‐α‐phenylethylamine, is reported. It is obvious that with the use of the dextrorotatory enantiomer of α‐phenylethylamine, the levorotatory enantiomer of this thioacid will be isolated.
Three New Pentacyclic Triterpenoids from Centella asiatica
Authors: Shao Yan , Ou‐Yang Dan‐Wei , Gao Wen , Cheng Liang , Weng Xiao‐Xiang , Kong De‐Yun 
Published: July 2014

AbstractThree new pentacyclic triterpenoids, named centellasaponin I (1), centellasaponin J (2), and centellasaponin E (3), together with three known compounds, were isolated from the whole plants of Centella asiatica. Their structures were elucidated on the basis of chemical and spectral analysis, including 1D‐ and 2D‐NMR and HR‐MS experiments, and by comparison with literature data.