bluuebunny/crossref_metadata_2025_split huggingface dataset:
Photoinduced Formation of Peroxide Ions on La2O3 and Nd2O3 under O2: Effects of Excitation Wavelength and Crystal Structure
Authors: Jing Xiao‐Lian , She Wen‐Yu , Li Jian‐Mei , Chen Qing‐Chuan , Weng Wei‐Zheng , An Dong‐Li , Wan Hui‐Lin 
Published: May 2015

AbstractPhotoinduced formation of peroxide ions on La2O3 and Nd2O3 under O2 was studied by in‐situ microprobe Raman spectroscopy with attention focused on the effect of excitation wavelength and crystal structure on the O22− formation. It was found that photoexcitations at 633, 532, 514, and 325 nm can induce O22− formation over La2O3 at 450 °C. By contrast, photoexcitation at 785 nm does not cause formation of O22− up to 500 °C. Photoexcitation at 325 nm can induce O22− formation on cubic Nd2O3 at 25 °C, but cannot induce O22− formation on hexagonal Nd2O3 up to 200 °C. The significant difference in the behavior of O22− formation over the Nd2O3 samples of the two structures can be related to the difference in the capacity to adsorb O2. Since the number of oxygen vacancies in cubic Nd2O3 is larger than that in the hexagonal one, the former has a higher capacity than the latter to adsorb O2. As a result, cubic Nd2O3 is more favorable to the reaction of O2 with O2− to generate O22−. The structural similarity between cubic Nd2O3 and Nd2O2(O2) may be another factor in favor of peroxide formation.
Investigation on the Surface‐Confined Self‐Assembly Stabilized by Hydrogen Bonds of Urea and Amide Groups: Quantitative Analysis of Concentration Dependence of Surface Coverage
Authors: Nishitani Nobuhiko , Hirose Takashi , Matsuda Kenji 
Published: May 2015

AbstractFormation of a hydrogen‐bond network via an amide group is a key driving force for the nucleation–elongation‐type self‐assembly that is often seen in biomolecules and artificial supramolecular assemblies. In this work, rod‐coil‐like aromatic compounds bearing an amide (1 a–3 a) or urea group (1 u–3 u) were synthesized, and their self‐assemblies on a 2‐D surface were investigated by scanning tunneling microscopy (STM). According to the quantitative analysis of the concentration dependence of the surface coverage, it was revealed that the strength of the hydrogen bond (i.e., amide or urea) and the number of non‐hydrogen atoms in a molecular component (i.e., size of core and length of alkyl side chain) play a primary role in determining the stabilization energy during nucleation and elongation processes of molecular ordering on the HOPG surface.
Three‐Component Supramolecular System with Multistimuli‐Responsive Properties in Water
Authors: Wang Bin , Liu Hua‐Ji , Fu Xiao‐Bin , Yao Yefeng , Chen Yu 
Published: May 2015

AbstractHyperbranched polyethylenimine terminated with isobutyramide groups (HPEI‐IBAm), 4‐(phenylazo)benzoic acid (PABA), and α‐cyclodextrin (α‐CD) were assembled together at pH≈7 to form the three‐component supramolecular complexes that were verified by 1H and 2D ROESY 1H NMR spectroscopy. UV/Vis spectrometric titration experiments showed that the content of α‐CD in the three‐component complexes was less than the feed amount and it was difficult for all the PABA units in the complexes to further form complexes with α‐CD. The obtained three‐component supramolecular complexes exhibited thermoresponsive properties in water. Increasing the α‐CD concentration led to a sharp increase in the cloud point temperature (Tcp) at the beginning, but after the [α‐CD]/[PABA] ratio was in the region of 1.3–1.6, the Tcp increased gradually When the concentration of α‐CD was low, a higher concentration of PABA led to a lower Tcp, however, the opposite was observed when the concentration of α‐CD was high. For the three‐component complex, increasing the α‐CD concentration at pH≈7 or at pH≈9 led to different Tcp temperatures. In the low α‐CD concentration range, adjusting the pH from ≈7–≈9 resulted in an increase in the Tcp, similar but not so pronounced as that of the two‐component system of HPEI‐IBAm/[PABA]. When the concentration of α‐CD was high, adjusting the pH from ≈7–≈9 decreased the Tcp; this observation is different to that of the two‐component system of HPEI‐IBAm/[PABA]. Reversible trans‐to‐cis photoisomerization of azobenzene units in the complexes occurred, following irradiation with UV or visible light. Trans‐to‐cis isomerization of azobenzene units decreased the Tcp. However, this result differed to that of the two‐component system of HPEI‐IBAm/PABA.
A simple method for expression and purification of Shiga toxin 1 (Stx1) with biological activities by using a single‐promoter vector and native signal peptide
Authors: Tu Wei , Li Tao , Wang Qin , Cai Kun , Gao Xiang , Wang Hui 
Published: May 2015

AbstractThe entire stx1 region from Escherichia coli O157:H7, containing two open reading frames (stx1a and stx1b), was cloned into pET‐32a with a single promoter. This region was transformed into E. coli TransB (DE3), which is a trxB and gor mutation strain. After expression in the E. coli periplasm in a completely soluble form, the rStx1 was purified and verified by sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS‐PAGE), ELISA, and Western blot analysis. Our rStx1 have Vero cell median cytotoxic dose (CD50) and median lethal dose (LD50) values of approximately 30 ng and 1.5 µg, respectively. The final yield of the purified rStx1 ranged from 2 to 3 mg/L by one‐step nickel affinity gel column chromatography. This method is an easy approach to the large‐scale preparation of Stx1 at a reasonable cost.
Isoniazid‐induced polyneuropathy in a tuberculosis patient – implication for individual risk stratification with genotyping?
Authors: Stettner Mark , Steinberger Daniela , Hartmann Christian J. , Pabst Tatjana , Konta Lidija , Hartung Hans Peter , Kieseier Bernd C. 
Published: May 2015

AbstractBackgroundDevelopment of polyneuropathy (PNP) under treatment for tuberculosis (TB), including isoniazid (INH), is a highly relevant adverse drug effect. The NAT2 acetylation status is a predictor of potential toxic effects of INH. The question as to whether individual risk stratification by genotyping is useful to avoid suffering of patients and to lower costs for the health care system is of considerable clinical importance.Case PresentationAfter drug treatment for TB, including INH, a 23‐year‐old man developed severe PNP. During the treatment, laboratory results have been indicating incipient liver and renal injury. Later, molecular genetic analyses were performed and revealed a variation in the NAT2 gene and the c1/c2 genotype of the CYP2E1 gene, both described to contribute to an elevated risk for anti‐tuberculostatic‐induced liver damages (ATIL).ConclusionThe combination of metabolizer genotypes should be taken into account as a cause for toxic effects and the development of PNP. Individual genotyping, performed before medication or at least if an elevation of liver parameters is observed, may reduce the risk of severe cases of PNP by early adjustment of treatment. Our case study indicates that evaluation of individual risk stratification with systematic pharmacogenetic genotyping of metabolizer gene combinations in the context of TB treatment should be addressed in clinical studies with larger cohorts.
C35 Hopanoid Side Chain Biosynthesis: Reduction of Ribosylhopane into Bacteriohopanetetrol by a Cell‐Free System Derived from Methylobacterium organophilum
Authors: Bodlenner Anne , Liu Wenjun , Hirsch Guillaume , Schaeffer Philippe , Blumenberg Martin , Lendt Ralf , Tritsch Denis , Michaelis Walter , Rohmer Michel 
Published: May 2015

AbstractThe major bacterial triterpenoids of the hopane series each consist of a C30 triterpene hopane moiety and an additional nonterpene C5 side chain derived from D‐ribose and linked through its C‐5 carbon atom to the hopane side chain. Bacteriohopanetetrol and aminobacteriohopanetriol are the most common representatives of this natural product series, adenosylhopane and ribosylhopane being putative precursors. Deuterium‐labelled ribosylhopane was obtained by hemisynthesis and converted into deuterium‐labelled bacteriohopanetetrol in the presence of NADPH, thus giving evidence of this as yet unknown precursor‐to‐product relationship in the bacterial hopanoid metabolic pathway.
Diversified Structural Basis of a Conserved Molecular Mechanism for pH‐Dependent Dimerization in Spider Silk N‐Terminal Domains
Authors: Otikovs Martins , Chen Gefei , Nordling Kerstin , Landreh Michael , Meng Qing , Jörnvall Hans , Kronqvist Nina , Rising Anna , Johansson Jan , Jaudzems Kristaps 
Published: May 2015

AbstractConversion of spider silk proteins from soluble dope to insoluble fibers involves pH‐dependent dimerization of the N‐terminal domain (NT). This conversion is tightly regulated to prevent premature precipitation and enable rapid silk formation at the end of the duct. Three glutamic acid residues that mediate this process in the NT from Euprosthenops australis major ampullate spidroin 1 are well conserved among spidroins. However, NTs of minor ampullate spidroins from several species, including Araneus ventricosus (AvMiSp NT), lack one of the glutamic acids. Here we investigate the pH‐dependent structural changes of AvMiSp NT, revealing that it uses the same mechanism but involves a non‐conserved glutamic acid residue instead. Homology modeling of the structures of other MiSp NTs suggests that these harbor different compensatory residues. This indicates that, despite sequence variations, the molecular mechanism underlying pH‐dependent dimerization of NT is conserved among different silk types.
An over‐nonlocal implicit gradient‐enhanced damage‐plastic model for trabecular bone under large compressive strains
Authors: Hosseini Hadi S. , Horák Martin , Zysset Philippe K. , Jirásek Milan 
Published: May 2015

SummaryPurpose: Investigation of trabecular bone strength and compaction is important for fracture risk prediction. At 1–2% compressive strain, trabecular bone undergoes strain softening, which may lead to numerical instabilities and mesh dependency in classical local damage‐plastic models. The aim of this work is to improve our continuum damage‐plastic model of bone by reducing the influence of finite element mesh size under large compression.Methodology: This spurious numerical phenomenon may be circumvented by incorporating the nonlocal effect of cumulated plastic strain into the constitutive law. To this end, an over‐nonlocal implicit gradient model of bone is developed and implemented into the finite element software ABAQUS using a user element subroutine. The ability of the model to detect the regions of bone failure is tested against experimental stepwise loading data of 16 human trabecular bone biopsies.Findings: The numerical outcomes of the nonlocal model revealed reduction of finite element mesh dependency compared with the local damage‐plastic model. Furthermore, it helped reduce the computational costs of large‐strain compression simulations.Originality: To the best of our knowledge, the proposed model is the first to predict the failure and densification of trabecular bone up to large compression independently of finite element mesh size. The current development enables the analysis of trabecular bone compaction as in osteoporotic fractures and implant migration, where large deformation of bone plays a key role. Copyright © 2015 John Wiley & Sons, Ltd.
Dynamic flow characteristics in normal and asthmatic lungs
Authors: Kim Minsuok , Bordas Rafel , Vos Wim , Hartley Ruth A. , Brightling Chris E. , Kay David , Grau Vicente , Burrowes Kelly S. 
Published: May 2015

SummaryComplex flow patterns exist within the asymmetric branching airway network in the lungs. These flow patterns are known to become increasingly heterogeneous during disease as a result of various mechanisms such as bronchoconstriction or alterations in lung tissue compliance. Here, we present a coupled model of tissue deformation and network airflow enabling predictions of dynamic flow properties, including temporal flow rate, pressure distribution, and the occurrence of reverse flows. We created two patient‐specific airway geometries, one for a healthy subject and one for a severe asthmatic subject, derived using a combination of high‐resolution CT data and a volume‐filling branching algorithm. In addition, we created virtually constricted airway geometry by reducing the airway radii of the healthy subject model. The flow model was applied to these three different geometries to solve the pressure and flow distribution over a breathing cycle. The differences in wave phase of the flows in parallel airways induced by asymmetric airway geometry and bidirectional interaction between intra‐acinar and airway network pressures were small in central airways but were more evident in peripheral airways. The asthmatic model showed elevated ventilation heterogeneity and significant flow disturbance. The reverse flows in the asthmatic model not only altered the local flow characteristics but also affected total lung resistance. The clinical significance of temporal flow disturbance on lung ventilation in normal airway model is obscure. However, increased flow disturbance and ventilation heterogeneity observed in the asthmatic model suggests that reverse flow may be an important factor for asthmatic lung function. Copyright © 2015 John Wiley & Sons, Ltd.
Shore platform lowering due to frost shattering during the 2009 winter at mesnil Val, English channel coast, NW France
Authors: Dewez T. J. B. , Regard V. , Duperret A. , Lasseur E. 
Published: May 2015

AbstractIn 2008–2009, a severe cold snap affected the otherwise temperate mid‐latitude coasts of the English Channel of France. In March 2009, we gathered rock spalling observations at Mesnil Val, NW France, to document the effect of frost on platform lowering in macro‐tidal environments. Six epochs of frost were recorded in 2 months, the two longest lasted 16 and 8 days, with minimum air temperature dropping to –9.5°C. Semi‐diurnal tides flood the entire platform, imposing up to 25 freeze–thaw cycles below –2.5°C, the freezing temperature of seawater. 19 cycles occurred at neap tidal elevation lasting at most 3.5 h. Our integrated observations indicate that these frost cycles were responsible for a platform lowering of about 0.8±0.5 mm during a single winter. No clear spatial trend appears, nor do macroscopic chalk types clearly stand out as being more susceptible to erosion. Assuming that the long‐term platform retreat model preserves a constant slope, frost shattering would then account for 10 to 20% of the expected annual platform erosion rate. Under more contrasted climates, frost is thus likely to be a prominent shaping process for rocky coastal platforms. Copyright © 2015 John Wiley & Sons, Ltd.
Assessing the transport of total phosphorus from a prairie river basin using SPARROW
Authors: Morales‐Marín Luis , Wheater Howard , Lindenschmidt Karl‐Erich 
Published: May 2015

AbstractRecent changes in land use and new industrial developments in river basins around the world have raised serious concerns regarding future water quality. Assessment of regional nutrient export from river basins are needed in order to identify main nutrient sources and hydrological variables involved. The Red Deer River catchment in Alberta, Canada has been chosen as a test case to assess total phosphorus export regionally. Agricultural and livestock activities in the catchment have increased manure production and the supply of fertilizer to crops. Oil and gas exploitation has also increased the risk of surface water and groundwater contamination. The rapid population growth has not only lead to increases in water consumption and wastewater discharges but also to further construction of transportation infrastructure and the expansion of new urban developments. This has imposed hydraulic controls on waterways, affecting the catchment hydrology and changing the dynamics of sediment and nutrient transport. River ecosystems are not exempt from the negative effects of water quality deterioration. Downstream from the city of Red Deer, the physiology and reproduction habits of native fish species have changed because of high riverine productivity. Although improvements have been made to surface water quality standards by Alberta Environment, further research is needed in order to identify major nutrient sources and quantify nutrient export. The SPAtially Referenced Regression On Watershed model has therefore been used in this study of the Red Deer River catchment to assess regional water quality, in order to describe the spatial and temporal patterns of the processes that affect water quality. The model is suitable for interpreting monitoring data sets that suffer from network sparseness, bias and basin heterogeneity. Ultimately, the model could provide improved information to environmental agencies to guide future water quality management practices and policies. Copyright © 2015 John Wiley & Sons, Ltd.
In vivo quantitative whole‐brain T1 rho MRI of multiple sclerosis
Authors: Gonyea Jay V. , Watts Richard , Applebee Angela , Andrews Trevor , Hipko Scott , Nickerson Joshua P. , Thornton Lindsay , Filippi Christopher G. 
Published: May 2015

BackgroundTo apply quantitative whole‐brain T1‐rho (T1ρ) and T2 imaging to the detection and quantification of brain changes resulting from multiple sclerosis (MS).MethodsTwenty‐three MS patients with clinically isolated syndrome (10) and relapsing remitting MS (13) phenotypes, compared with 24 age‐matched healthy controls were imaged at 3 Tesla. An axial T1ρ‐weighted three‐dimensional turbo spin echo sequence with a variable flip angle and fluid suppression was used. Spin‐lock times of 0, 20, 40, 60, 80, and 100 ms were used. Corresponding T2 maps were also acquired.ResultsWhole brain white matter (WM) T1ρ maps were elevated compared with controls (P = 0.002). WM lesion T1ρ and T2 values were highly correlated (r = 0.83), but T1ρ demonstrated 25% better contrast to noise ratio (P < 0.001). WM lesion T1ρ correlated with disease duration. Gray matter T1ρ was negatively correlated with the Expanded Disability Status Scale, r = −0.45, P = 0.03. Normal appearing gray matter and cortical gray matter lesions were negatively correlated on T1ρ, but not on T2 (rT1ρ = −0.63, pT1ρ = 0.03; rT2 = −0.17, pT2 = 0.6).ConclusionT1ρ MRI demonstrates enhanced lesion contrast compared with T2, and in some cases may provide complementary information. T1ρ may provide a useful measure of demyelinating processes in MS. J. MAGN. RESON. IMAGING 2015;42:1623–1630.
Effects of Shrub Islands Created by Rhodomyrtus tomentosa (Aiton) Hassk. on the Growth, Chlorophyll Fluorescence, and Chloroplast ultrastructure of Pine Seedlings in Degraded Land of South China
Authors: Yang Long , Chen Yanqiao , Huang Yuhui , Li Yu , Wen Meili , Liu Nan , Wang Jun 
Published: May 2015

AbstractIn degraded land of South China, the shrub Rhodomyrtus tomentosa (Aiton) Hassk. grows in aggregations and creates “shrub islands” with increased soil porosity and soil moisture but reduced soil nutrient content and light penetration. Previous researches indicated that these shrub islands can facilitate establishment of broad‐leaved tree seedlings. Because conifers are commonly used in reforestation projects, we determined whether shrub islands created by R. tomentosa also facilitate coniferous seedlings. Two common conifers, the native Pinus massoniana and the exotic Pinus elliottii, were transplanted on shrub islands and in open spaces (controls) between islands, and their growth, chlorophyll fluorescence, and chloroplast ultrastructure were investigated. Neither of the pine species was facilitated by the shrub islands. P. elliottii grew obviously higher in the open than under the R. tomentosa canopy, while P. massoniana was not facilitated by shrub islands, but it was not hindered either. The reduced growth of P. elliottii on shrub islands was associated with dilation of thylakoids in chloroplasts of mesophyll cells, lowered chlorophyll content, and reduced electron transport rate values. The results of this study indicate that P. elliottii should be transplanted in open spaces, and P.  massoniana can be transplanted in open spaces or on shrub islands as part of restoration efforts, and the restoration technology of shrub island should be carefully used in degraded land of South China according to the species identity. Copyright © 2015 John Wiley & Sons, Ltd.
Perinatal exposure to androgen excess and the effects on the rat uterine estradiol responsiveness
Authors: Guerra Marina T. , Sanabria Marciana , Petrusz Peter , De Grava Kempinas Wilma 
Published: May 2015

ABSTRACTAndrogen exposure during sexual development induces alterations in steroidal target tissues. The objective of this study was to evaluate the uterine responsiveness to estradiol after perinatal androgenization. Pregnant Wistar rats were exposed to corn oil or testosterone propionate at 0.05, 0.1, or 0.2 mg/kg from gestational day 12 until postnatal day 21. Female offspring was challenged with estradiol (E2) after weaning (0.4 mg/kg) and at adulthood (10 or 100 µg/day), when the pituitary response was also evaluated. At adulthood, control and 0.05 mg/kg groups presented a uterine weight increment when exposed to 100 µg/day of E2, 0.1 mg/kg group only responded to 10 µg/day of E2, and the 0.2 mg/kg group showed increased uterine weight at both doses. The pituitary weight was similarly increased after estradiol stimulation in all experimental groups. In conclusion, testosterone propionate exposure induced an abnormal stimulation of uterine tissue growth by estrogen stimulus without affecting pituitary response. More studies are needed to clarify whether these alterations are capable of impairing the reproductive capacity of the female tract. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1460–1468, 2016.
Review: Morphofunctional and biochemical markers of stress in sea urchin life stages exposed to engineered nanoparticles
Authors: Gambardella Chiara , Ferrando Sara , Gatti Antonietta M. , Cataldi Edoardo , Ramoino Paola , Aluigi Maria Grazia , Faimali Marco , Diaspro Alberto , Falugi Carla 
Published: May 2015

ABSTRACTWe describe the use of different life stages of the Mediterranean sea urchin Paracentrotus lividus for the assessment of the possible risk posed by nanoparticles (NPs) in the coastal water. A first screening for the presence of NPs in sea water may be obtained by checking their presence inside tissues of organisms taken from the wild. The ability of NPs to pass from gut to the coelomic fluid is demonstrated by accumulation in sea urchin coelomocytes; the toxicity on sperms can be measured by embryotoxicity markers after sperm exposure, whereas the transfer through the food chain can be observed by developmental anomalies in larvae fed with microalgae exposed to NPs. The most used spermiotoxicity and embryotoxicity tests are described, as well as the biochemical and histochemical analyses of cholinesterase (ChE) activities, which are used to verify toxicity parameters such as inflammation, neurotoxicity, and interference in cell‐to‐cell communication. Morphological markers of toxicity, in particular skeletal anomalies, are described and classified. In addition, NPs may impair viability of the immune cells of adult specimens. Molecular similarity between echinoderm and human immune cells is shown and discussed. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1552–1562, 2016.