bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis and biological evaluation of novel ursolic acid analogues as potential α-glucosidase inhibitors
Authors: Wu Pan-Pan , Zhang Bing-Jie , Cui Xi-Ping , Yang Yang , Jiang Zheng-Yun , Zhou Zhi-Hong , Zhong Ying-Ying , Mai Yu-Ying , Ouyang Zhong , Chen Hui-Sheng , Zheng Jie , Zhao Su-Qing , Zhang Kun
Published: March 2017

Ursolic acid (UA) is a major pentacyclic triterpenoid in plants, vegetables and fruits, which has been reported to have a potential anti-diabetic activity. Despite various semi-synthetic ursolic acid derivatives already described, new derivatives still need to be designed and synthesized to further improve the anti-diabetic activity. In the present study, two series of novel UA derivatives, were synthesized and their structures were confirmed. The enzyme inhibition activities of semi-synthesized analogues against α-glucosidase were screened in vitro. The results indicated that most of UA derivatives showed a significant inhibitory activity, especially analogues UA-O-i with the IC50 values of 0.71 ± 0.27 μM, which was more potential than other analogues and the positive control. Furthermore, molecular docking studies were also investigated to verify the in vitro study. Structure modification at the C-3 and C-2 positions of UA was an effective approach to obtain the desired ligand from UA, whose structure was in accordance with the active pocket. Besides, suitable hydrophobic group at the position of C-2 might play an important role for the docking selectivity and binding affinity between the ligand and the homology modelling protein. These results could be helpful for designing more potential α-glucosidase inhibitors from UA in the future.
Molecular Therapy for Degenerative Disc Disease: Clues from Secretome Analysis of the Notochordal Cell-Rich Nucleus Pulposus
Authors: Matta Ajay , Karim M. Zia , Isenman David E. , Erwin W. Mark
Published: March 2017

Degenerative disc disease (DDD) is associated with spinal pain often leading to long-term disability. However, the non-chondrodystrophic canine intervertebral disc is protected from the development of DDD, ostensibly due to its retention of notochordal cells (NC) in the nucleus pulposus (NP). In this study, we hypothesized that secretome analysis of the NC-rich NP will lead to the identification of key proteins that delay the onset of DDD. Using mass-spectrometry, we identified 303 proteins including components of TGFβ- and Wnt-signaling, anti-angiogeneic factors and proteins that inhibit axonal ingrowth in the bioactive fractions of serum free, notochordal cell derived conditioned medium (NCCM). Ingenuity Pathway Analysis revealed TGFβ1 and CTGF as major hubs in protein interaction networks.In vitrotreatment with TGFβ1 and CTGF promoted the synthesis of healthy extra-cellular matrix proteins, increased cell proliferation and reduced cell death in human degenerative disc NP cells. A single intra-discal injection of recombinant TGFβ1 and CTGF proteins in a pre-clinical rat-tail disc injury model restored the NC and stem cell rich NP. In conclusion, we demonstrate the potential of TGFβ1 and CTGF to mitigate the progression of disc degeneration and the potential use of these molecules in a molecular therapy to treat the degenerative disc.
Fluorescence based real time monitoring of fouling in process chromatography
Authors: Pathak Mili , Lintern Katherine , Chopda Viki , Bracewell Daniel G. , Rathore Anurag S.
Published: March 2017

A real time monitoring of fouling in liquid chromatography has been presented. The versatility of the approach has been proven by successful implementation in three case studies with an error <1%. The first application demonstrates the monitoring of protein A ligand density and foulant concentration for assessing performance of protein A chromatography resin during purification of monoclonal antibodies. The observations have been supported from LC-MS/MS studies that were independently performed. The second application involves monitoring of foulant deposition during multimode cation exchange chromatography based purification of human serum albumin. Finally, in the third application, monitoring of foulants during multimodal hydrophobic interaction chromatography of recombinant human granulocyte colony stimulating factor is demonstrated. In all three cases, it is observed that the fluorescence intensity consistently increases with resin reuse as more foulants are deposited over time. The proposed approach can be readily used for real time monitoring of fouling and process control.
Influence of human population movements on urban climate of Beijing during the Chinese New Year holiday
Authors: Zhang Jingyong , Wu Lingyun
Published: March 2017

The population movements for the Chinese New Year (CNY) celebrations, known as the world’s largest yearly migration of human beings, have grown rapidly in the past several decades. The massive population outflows from urban areas largely reduce anthropogenic heat release and modify some other processes, and may thus have noticeable impacts on urban climate of large cities in China. Here, we use Beijing as an example to present observational evidence for such impacts over the period of 1990–2014. Our results show a significant cooling trend of up to 0.55 °C per decade, particularly at the nighttime during the CNY holiday relative to the background period. The average nighttime cooling effect during 2005–2014 reaches 0.94 °C relative to the 1990s, significant at the 99% confidence level. The further analysis supports that the cooling during the CNY holiday is attributable primarily to the population outflow of Beijing. These findings illustrate the importance of population movements in influencing urban climate despite certain limitations. As the world is becoming more mobile and increasingly urban, more efforts are called for to understand the role of human mobility at various spatial and temporal scales.
Cilia distribution and polarity in the epithelial lining of the mouse middle ear cavity
Authors: Luo Wenwei , Yi Hong , Taylor Jeannette , Li Jian-dong , Chi Fanglu , Todd N. Wendell , Lin Xi , Ren Dongdong , Chen Ping
Published: March 2017

The middle ear conducts sound to the cochlea for hearing. Otitis media (OM) is the most common illness in childhood. Moreover, chronic OM with effusion (COME) is the leading cause of conductive hearing loss. Clinically, COME is highly associated with Primary Ciliary Dyskinesia, implicating significant contributions of cilia dysfunction to COME. The understanding of middle ear cilia properties that are critical to OM susceptibility, however, is limited. Here, we confirmed the presence of a ciliated region near the Eustachian tube orifice at the ventral region of the middle ear cavity, consisting mostly of a lumen layer of multi-ciliated and a layer of Keratin-5-positive basal cells. We also found that the motile cilia are polarized coordinately and display a planar cell polarity. Surprisingly, we also found a region of multi-ciliated cells that line the posterior dorsal pole of the middle ear cavity which was previously thought to contain only non-ciliated cells. Our study provided a more complete understanding of cilia distribution and revealed for the first time coordinated polarity of cilia in the epithelium of the mammalian middle ear, thus illustrating novel structural features that are likely critical for middle ear functions and related to OM susceptibility.
Molecular imaging probes for multi-spectral optoacoustic tomography
Authors: Gujrati Vipul , Mishra Anurag , Ntziachristos Vasilis
Published: March 2017

In this review, we discuss recent progress in emerging optoacoustic probes, their mechanisms, applications and challenges for biological imaging using MSOT.
The effects of structural changes on the anti-microbial and anti-proliferative activities of diimidazolium salts
Authors: Cancemi Patrizia , Buttacavoli Miriam , D'Anna Francesca , Feo Salvatore , Fontana Rosa Maria , Noto Renato , Sutera Alberto , Vitale Paola , Gallo Giuseppe
Published: March 2017

Anti-microbial and anti-proliferative activities of diimidazolium salts have been analyzed as a function of the main changes in their structural features.
A synthetic route towards 3,4-disubstituted pyrrolidin-2-ones via a Michael addition and reductive ring closing strategy
Authors: Dawange Monali , Parekh Nikita , Kumbhar Avinash , Dehaen Wim , Kusurkar Radhika
Published: March 2017

2-Pyrrolidinone scaffolds with a wide range of substituents were synthesized with good yield and diastereoselectivity.
Stimuli-responsive multifunctional glyconanoparticle platforms for targeted drug delivery and cancer cell imaging
Authors: Wu Xumeng , Tan Yu Jia , Toh Hui Ting , Nguyen Lan Huong , Kho Shu Hui , Chew Sing Yian , Yoon Ho Sup , Liu Xue-Wei
Published: March 2017

A targeting system with excellent targeting ability is constructed by incorporating carbohydrate-modified gold nanoparticles as vehicles and GSH-responsive species as the payload.
Rapid simultaneous extraction and magnetic particle-based enzyme immunoassay for the parallel determination of ochratoxin A, fumonisin B1 and deoxynivalenol mycotoxins in cereal samples
Authors: Vidal J. C. , Bertolín J. R. , Ezquerra A. , Hernández S. , Castillo J. R.
Published: March 2017

This work describes the development of a rapid method for the extraction and the immunochemical determination of three mycotoxins, deoxynivalenol, fumonisin B1, and ochratoxin A, from cereal samples (wheat and corn flours).
Layer-independent and layer-dependent nonlinear optical properties of two-dimensional GaX (X = S, Se, Te) nanosheets
Authors: Hu Lei , Huang Xuri , Wei Dongshan
Published: March 2017

The magnitude of SHG coefficients for monolayers and AAA gets very close, while it becomes about 1/3 for ABA.
Transformation of PbI2, PbBr2 and PbCl2 salts into MAPbBr3 perovskite by halide exchange as an effective method for recombination reduction
Authors: Belarbi Eya , Vallés-Pelarda Marta , Clasen Hames Bruno , Sanchez Rafael S. , Barea Eva M. , Maghraoui-Meherzi Hager , Mora-Seró Iván
Published: March 2017

Properties of MAPbBr3 layers and devices prepared using halide exchange strongly depend on the precursor PbX2 halide salts.
Selectivity of quantum dot sensitized ZnO nanotube arrays for improved photocatalytic activity
Authors: Gao Ge , Xi Qiaoyue , Zhou Hua , Zhao Yongxia , Wu Cunqi , Wang Lidan , Guo Pengran , Xu Jingwei
Published: March 2017

QD-sensitized ZnO heterostructures with different kinds and cycles of QDs exhibit different photocatalytic activity and the selectivity of the best QDs sensitizing ZnO for high photocatalytic activity is realized.
Synthesis of copper hydride (CuH) from CuCO3·Cu(OH)2 – a path to electrically conductive thin films of Cu
Authors: Lousada Cláudio M. , Fernandes Ricardo M. F. , Tarakina Nadezda V. , Soroka Inna L.
Published: March 2017

High purity CuH nano-sized particles have been synthesized in aqueous media and then converted to electrically conductive thin films.
Achieving yellow emission by varying the donor/acceptor units in rod-shaped fluorenyl-alkynyl based π-conjugated oligomers and their binuclear gold(i) alkynyl complexes
Authors: Islam Sk Najmul , Sil Amit , Patra Sanjib K.
Published: March 2017

Yellow light emitting fluorenyl-alkynyl based D–π-A–π-D rod-shaped oligomers with alkynyl termini and the corresponding binuclear Au(i) organometallic wires are achieved by fine-tuning the bandgap through the systematic modulation of the π-conjugated spacers.
Differential α-amylase/α-glucosidase inhibitory activities of plant-derived phenolic compounds: a virtual screening perspective for the treatment of obesity and diabetes
Authors: Rasouli Hassan , Hosseini-Ghazvini Seyed Mohammad-Bagher , Adibi Hadi , Khodarahmi Reza
Published: March 2017

The present study aims to evaluate the α-amylase and α-glucosidase inhibitory activity of 26 polyphenols using molecular docking and virtual screening studies.
Blue light mediated C–H arylation of heteroarenes using TiO2as an immobilized photocatalyst in a continuous-flow microreactor
Authors: Fabry David C. , Ho Yee Ann , Zapf Ralf , Tremel Wolfgang , Panthöfer Martin , Rueping Magnus , Rehm Thomas H.
Published: March 2017

Improved contacting of TiO2catalyst, substrate and light results in an impressive boost in reactor performance for blue light mediated C–H arylation of heteroarenes in continuous-flow mode.
Mechanistic model for the firefly luciferin regeneration in biomimetic conditions: a model for the in vivo process?
Authors: Salatino Carla T. , Melo Diêgo U. , Yoshitake Ariane M. , Sgarbi Lucas S. , Homem-de-Mello Paula , Bartoloni Fernando H. , Ciscato Luiz F. M. L.
Published: March 2017

Firefly luciferin is recycled backin vivoby 2-cyano-6-hydroxybenzothiazole coupling with cysteine in a complex multi-step process involving specific base catalysis.
Tf2NH-catalyzed formal [3 + 2] cycloaddition of oxadiazolones with ynamides: a simple access to aminoimidazoles
Authors: Zhao Yingying , Hu Yancheng , Li Xincheng , Wan Boshun
Published: March 2017

We herein develop a formal [3 + 2] approach to access aminoimidazoles through the Tf2NH-catalyzed cycloaddition of oxadiazolones with ynamides, in which oxadiazolones are first employed as the three-atom building units.
A comprehensive kinetic study of the conventional free-radical polymerization of seven-membered cyclic ketene acetals
Authors: Tardy Antoine , Honoré Jean-Claude , Siri Didier , Nicolas Julien , Gigmes Didier , Lefay Catherine , Guillaneuf Yohann
Published: March 2017

The current study reports on the kinetic analysis of the free-radical polymerization of several seven-membered cyclic ketene acetal monomers.
A comparative study of the effect of functional groups on C2H2 adsorption in NbO-type metal–organic frameworks
Authors: Chen Fengli , Bai Dongjie , Wang Xia , He Yabing
Published: March 2017

A comparative study of the effect of functional groups on C2H2 adsorption was performed in NbO-type metal–organic frameworks.
Releasable and traceless PEGylation of arginine-rich antimicrobial peptides
Authors: Gong Y. , Andina D. , Nahar S. , Leroux J.-C. , Gauthier M. A.
Published: March 2017

This study reports a strategy to temporarily mask arginine residues within antimicrobial peptides (AMPs) with methoxy poly(ethylene glycol) (mPEG). PEGylation protects AMPs from serum proteases, and can be released at a pharmaceutically-relevant rate. Fully active and unmodified (i.e., native) AMPs are released with time.
A randomized placebo-controlled clinical study of nab-paclitaxel as second-line chemotherapy for patients with advanced non-small cell lung cancer in China
Authors: Wu Yueming , Feng Jiang , Hu Weiwei , Luo Qingquan
Published: March 2017

We performed a randomized and placebo-controlled clinical study to investigate whether nab-paclitaxel can improve survival in patients with advanced non-small cell lung cancer (NSCLC) after unsuccessful first-line chemotherapy. Patients with stages III to IV advanced NSCLC after first-line platinum-based chemotherapy failure were randomly assigned in a 1:1 ratio to receive second-line treatment of nab-paclitaxel or placebo. Ninety two eligible patients were enrolled in the study. The median progression-free survival (PFS) was 4.6 months (95% confidence interval (CI): 3.4–6.7 months) for nab-paclitaxel, compared with 2.0 months (95% CI: 0.9–4.3 months) for placebo, representing a 56% reduction in disease progression (hazard ratio: 0.62; 95% CI: 0.33–0.81; P<0.001). The median overall survival (OS) was 6.3 months (95% CI: 3.9–8.2 months) for nab-paclitaxel, compared with 4.9 months (95% CI: 2.1–5.9 months) for placebo, representing a 22% reduction in disease progression (hazard ratio: 0.71; 95% CI: 0.33–0.85; P<0.001). Adverse events (AEs) were also observed for nab-paclitaxel. Nab-paclitaxel can improve survival in patients with advanced NSCLC after unsuccessful first-line chemotherapy.
Influence of partial substitution for carbon black with graphene oxide on dynamic properties of natural rubber composites
Authors: Zhang Huan , Wei Yintao , Kang Zhenran , Zhao Guizhe , Liu Yaqing
Published: March 2017

Nanosheets of graphene oxide (GO) were incorporated into natural rubber (NR) to investigate the influence of the partial substitution for carbon black (CB) with GO on the crosslink structure and properties of NR composites. The results show that the dispersion of the fillers was improved by a few GO nanosheets instead of CB. The dynamic and static mechanical properties were improved by using a few GO nanosheets worth of substitution content. The NR/CB/GO (NG) composites show the lowest heat buildup value when the load of nanosheets is 1 phr, which corresponds to only 9°C. However, the comprehensive performance of the composites was poor, or even deteriorated, as the GO tended to aggregate due to the high concentrations.
PL of low‐density InAs/GaAs quantum dots with different bimodal populations
Authors: Wang Ying , Sheng Xinzhi , Liu Yao , Liang Baolai , Li Xiaoli , Guo Qinglin , Mazur Yuriy I. , Ware Morgan E. , Salamo Gregory J.
Published: March 2017

Optical response of the indium arsenide (InAs)/gallium arsenide (GaAs) quantum dots (QDs) with a bimodal distribution is investigated through varying an initial GaAs capping layer between 35 and 18 monolayers. Photoluminescence (PL) measurements confirm that a thinner initial capping layer can reduce the QD dimensions and also modify the population ratio between the large QDs and the small QDs. Therefore, PL quenching related to QD dimension and carrier transfer between the bimodal QD populations has been affected. Manipulation of the initial GaAs capping layer provides a feasible approach to tailor the formation and optical performance of InAs QDs for optoelectronic device applications.
Spinal Intramedullary Tuberculosis
Authors: Varghese Prithvi , Abdul Jalal Muhammed , Kandathil Julio , Mathew Iona
Published: March 2017

Tuberculosis of the central nervous system accounts for approximately 1% of all cases of tuberculosis and 50% of these involve the spine. Intramedullary involvement is rare in tuberculosis. Clinical presentation of spinal intramedullary tuberculosis (SIMT) is similar to intramedullary spinal cord tumor. Here, we report the case of a 49-year-old female with dull aching pain of both upper limbs of 1-week duration. On examination, she had no motor deficits. All the deep tendon reflexes were normal. The plantar responses were flexor bilaterally. Cervical spine imaging favored intramedullary tumor. She had partial relief of symptoms with steroid treatment. Repeat imaging done 1 month later revealed mild interval enlargement of the intramedullary lesions and multiple enlarged mediastinal and hilar nodes. Endoscopic ultrasound-guided fine-needle aspiration cytology of mediastinal nodes was suggestive of granulomatous inflammation. Hence, SIMT was considered as the probable diagnosis. The patient was started on antituberculosis therapy.
Die medizinische Rehabilitation als attraktives Arbeitsfeld für Ärztinnen und Ärzte? – Eine qualitative Befragung
Authors: Lederle Mareike , Kotzjan Priscilla , Niehues Christiane , Brüggemann Silke , Bitzer Eva-Maria
Published: March 2017

Im deutschen Gesundheitssystem gibt es einen zunehmenden Wettbewerb bei der Rekrutierung von Fachpersonal, insbesondere für die medizinische Rehabilitation, die als weniger attraktiv angesehen wird. Die vorliegende Studie untersucht daher die Attraktivität des Arbeitsfeldes der medizinischen Rehabilitation aus der Sicht des ärztlichen Personals.

Wir haben 16 leitfadengestützte Interviews mit Ärztinnen und Ärzten aus 7 Reha-Einrichtungen unterschiedlicher fachlicher Ausrichtung geführt. Die Interviews wurden digitalisiert, transkribiert und nach der strukturierenden Inhaltsanalyse mithilfe der Analysesoftware MAXQDA 11 ausgewertet.

Identifiziert wurden 745 Codes mit den übergeordneten Kategorien „Attraktivität“, „Ungünstige Aspekte“ und „Besonderheiten“ der Rehabilitation. Die Befragten schätzten im Vergleich zur Akutmedizin vor allem das planbare, flexible und mit weniger Zeitdruck verbundene Arbeiten in der medizinischen Rehabilitation. Neben der Arbeit mit den Rehabilitandinnen und Rehabilitanden erwies sich die Zusammenarbeit in einem interdisziplinären Team als bedeutsamer Faktor. Zu den Besonderheiten der Rehabilitation gehört die im Vergleich zur Akutmedizin höhere Relevanz des bio-psycho-sozialen Modells von Gesundheit und Krankheit sowie der höhere Kommunikations- und Organisationsbedarf.

Die medizinische Rehabilitation ist ein attraktives Arbeitsfeld für Ärztinnen und Ärzte, ein Merkmal, das in der Außendarstellung stärker als bisher genutzt werden sollte.
Parameter-free driven Liouville-von Neumann approach for time-dependent electronic transport simulations in open quantum systems
Authors: Zelovich Tamar , Hansen Thorsten , Liu Zhen-Fei , Neaton Jeffrey B. , Kronik Leeor , Hod Oded
Published: March 2017

A parameter-free version of the recently developed driven Liouville-von Neumann equation [T. Zelovich et al., J. Chem. Theory Comput. 10(8), 2927–2941 (2014)] for electronic transport calculations in molecular junctions is presented. The single driving rate, appearing as a fitting parameter in the original methodology, is replaced by a set of state-dependent broadening factors applied to the different single-particle lead levels. These broadening factors are extracted explicitly from the self-energy of the corresponding electronic reservoir and are fully transferable to any junction incorporating the same lead model. The performance of the method is demonstrated via tight-binding and extended Hückel calculations of simple junction models. Our analytic considerations and numerical results indicate that the developed methodology constitutes a rigorous framework for the design of “black-box” algorithms to simulate electron dynamics in open quantum systems out of equilibrium.
Predicting solvation free energies and thermodynamics in polar solvents and mixtures using a solvation-layer interface condition
Authors: Molavi Tabrizi Amirhossein , Goossens Spencer , Mehdizadeh Rahimi Ali , Knepley Matthew , Bardhan Jaydeep P.
Published: March 2017

We demonstrate that with two small modifications, the popular dielectric continuum model is capable of predicting, with high accuracy, ion solvation thermodynamics (Gibbs free energies, entropies, and heat capacities) in numerous polar solvents. We are also able to predict ion solvation free energies in water–co-solvent mixtures over available concentration series. The first modification to the classical dielectric Poisson model is a perturbation of the macroscopic dielectric-flux interface condition at the solute–solvent interface: we add a nonlinear function of the local electric field, giving what we have called a solvation-layer interface condition (SLIC). The second modification is including the microscopic interface potential (static potential) in our model. We show that the resulting model exhibits high accuracy without the need for fitting solute atom radii in a state-dependent fashion. Compared to experimental results in nine water–co-solvent mixtures, SLIC predicts transfer free energies to within 2.5 kJ/mol. The co-solvents include both protic and aprotic species, as well as biologically relevant denaturants such as urea and dimethylformamide. Furthermore, our results indicate that the interface potential is essential to reproduce entropies and heat capacities. These and previous tests of the SLIC model indicate that it is a promising dielectric continuum model for accurate predictions in a wide range of conditions.
Pressure-induced structural transitions of a room temperature ionic liquid—1-ethyl-3-methylimidazolium chloride
Authors: Chen Fengjiao , You Tingting , Yuan Ye , Pei Cuiying , Ren Xiangting , Huang Yanwei , Yu Zhenhai , Li Xiaodong , Zheng Haiyan , Pan Yuexiao , Yang Ke , Wang Lin
Published: March 2017

In this paper, structural evaluations of a room temperature ionic liquid, 1-ethyl-3-methylimidazolium chloride ([EMIM]Cl), were systematically investigated at high pressures. Our Raman spectra, infrared spectra, and synchrotron X-ray diffraction investigations show that crystalline [EMIM]Cl experienced structural instabilities at high pressures and underwent at least four successive structural transitions at around 5.8, 9.3, 15.8, and 19.1 GPa, respectively. Notably, the abrupt emergence of photoluminescence from the sample at around 19.3 GPa, originated from the pressure-induced polymerization of the [EMIM]+ cations, as confirmed by the mass spectrometry experiments. Our results also indicate that high pressure significantly affected the conformational equilibrium of the [EMIM]+ cations. The structural transitions are influenced by the ion stacking modes determined by the hydrogen bonds and possibly by some chemical reactions in addition to the cation conformational isomers.
Enhanced nonlinear spectroscopy for monolayers and thin films in near-Brewster’s angle reflection pump-probe geometry
Authors: Nishida Jun , Yan Chang , Fayer Michael D.
Published: March 2017

We experimentally demonstrate and theoretically explicate a method that greatly enhances the detection of third-order nonlinear signals from monolayers and thin films on dielectric substrates. Nonlinear infrared signals, including two dimensional infrared (2D IR) vibrational echo signals, were detected from a functionalized alkyl chain monolayer on a dielectric SiO2 surface in a near-Brewster’s angle reflection pump-probe geometry. We observed a tremendous enhancement of the signal-to-noise (S/N) ratio in this geometry compared with a conventional transmission pump-probe geometry signal. The S/N enhancement is achieved by the greatly increased modulation of the local oscillator (LO) field that is induced by the nonlinear signal field. By reducing the LO field without loss of the signal field, the modulation amplitude acquired in this geometry was enhanced by more than a factor of 50. The incident angle dependence of the enhancement was measured and the result agreed remarkably well with theoretical calculations. We combined this geometry with a germanium acousto-optic modulator pulse shaping system to apply 2D IR spectroscopy to the monolayer. The enhanced and phase-stable 2D IR spectra gave detailed dynamical information for the functionalized alkyl chain monolayer. The application of the method to films with finite thickness was described theoretically. The range of film thicknesses over which the method is applicable is delineated, and we demonstrate that accurate dynamical information from thin films can be obtained in spite of dispersive contributions that increase with the film thickness. While we focus on infrared experiments in this article, the method and the theory are applicable to visible and ultraviolet experiments as well.
Direct orientation sampling of diatomic molecules for path integral Monte Carlo calculation of fully quantum virial coefficients
Authors: Subramanian Ramachandran , Schultz Andrew J. , Kofke David A.
Published: March 2017

We develop an orientation sampling algorithm for rigid diatomic molecules, which allows direct generation of rings of images used for path-integral calculation of nuclear quantum effects. The algorithm treats the diatomic molecule as two independent atoms as opposed to one (quantum) rigid rotor. Configurations are generated according to a solvable approximate distribution that is corrected via the acceptance decision of the Monte Carlo trial. Unlike alternative methods that treat the systems as a quantum rotor, this atom-based approach is better suited for generalization to multi-atomic (more than two atoms) and flexible molecules. We have applied this algorithm in combination with some of the latest ab initio potentials of rigid H2 to compute fully quantum second virial coefficients, for which we observe excellent agreement with both experimental and simulation data from the literature.
Photoabsorption and photoionization cross sections for formaldehyde in the vacuum-ultraviolet energy range
Authors: Tanaka H. K. , Prudente F. V. , Medina A. , Marinho R. R. T. , Homem M. G. P. , Machado L. E. , Fujimoto M. M.
Published: March 2017

We report a theoretical-experimental investigation on the interaction of vacuum-ultraviolet radiation with formaldehyde (H2CO) in the gas phase. Experimentally, the absolute photoabsorption cross sections and the photoionization quantum yields were measured in the (11.0–21.5) eV range using the double-ion chamber technique. Also, the absolute photoionization and neutral-decay cross sections were derived from these data. In addition, in the same energy region, the dissociation pattern was obtained with a time-of-flight mass spectrometer using the photoelectron-photoion coincidence technique, and the absolute photoionization cross sections were derived for each ionic fragment observed. Moreover, theoretical photoionization cross sections were calculated for the ionization of the four outermost molecular valence orbitals (2b2, 1b1, 5a1, and 1b2) from the threshold to 35 eV. The calculations were performed using the iterative Schwinger variational method to solve the Lippmann-Schwinger equation in the exact static-exchange level of approximation. In general, there is a good agreement between our experimental and previous data reported in the literature. Our theoretical results show a fair qualitative agreement with the experimental data and with previous theoretical results. Above 20 eV, a better quantitative agreement with the experimental data is also observed.
Lanthanide Ionization Energies and the Sub-Shell Break. Part 1. The Second Ionization Energies
Authors: Johnson David A. , Nelson Peter G.
Published: March 2017

By interpolating a 4fq6s → 4fq7s transition within the sequence f1 → f14 rather than between f0 and f14, revised second ionization energies of the lanthanides have been obtained. In the early part of the series, between cerium and samarium, the revisions are significantly higher than currently accepted values. The revised values have been used to calculate the energy variation for the conversion of Ln(g, 4fq6s2) to Ln2+(g, 4fq) across the series Ba → Yb. The variation is smooth between lanthanum and ytterbium but the barium point at q = 0 is displaced downwards by more than 0.3 eV, thereby representing a significant sub-shell break. A case is also made for a substantial change to the second ionization energy of lutetium, the revised value being 14.13 ± 0.10 eV.
Atomic bonding and electrical potential at metal/oxide interfaces, a first principle study
Authors: Tea Eric , Huang Jianqiu , Li Guanchen , Hin Celine
Published: March 2017

A number of electronic devices involve metal/oxide interfaces in their structure where the oxide layer plays the role of electrical insulator. As the downscaling of devices continues, the oxide thickness can spread over only a few atomic layers, making the role of interfaces prominent on its insulating properties. The prototypical Al/SiO2 metal/oxide interface is investigated using first principle calculations, and the effect of the interfacial atomic bonding is evidenced. It is shown that the interface bonding configuration critically dictates the mechanical and electronic properties of the interface. Oxygen atoms are found to better delimit the oxide boundaries than cations. Interfacial cation-metal bonds allow the metal potential to leak inside the oxide layer, without atomic diffusion, leading to a virtual oxide thinning.
On the propagation and multiple reflections of a blast wave travelling through a dusty gas in a closed box
Authors: Lappa Marcello , Drikakis Dimitris , Kokkinakis Ioannis
Published: March 2017

This paper concerns the propagation of shock waves in an enclosure filled with dusty gas. The main motivation for this problem is to probe the effect on such dynamics of solid particles dispersed in the fluid medium. This subject, which has attracted so much attention over recent years given its important implications in the study of the structural stability of systems exposed to high-energy internal detonations, is approached here in the framework of a hybrid numerical two-way coupled Eulerian-Lagrangian methodology. In particular, insights are sought by considering a relatively simple archetypal setting corresponding to a shock wave originating from a small spherical region initialized on the basis of available analytic solutions. The response of the system is explored numerically with respect to several parameters, including the blast intensity (via the related value of the initial shock Mach number), the solid mass fraction (mass load), and the particle size (Stokes number). Results are presented in terms of pressure-load diagrams. Beyond practical applications, it is shown that a kaleidoscope of fascinating patterns is produced by the “triadic” relationships among multiple shock reflection events and particle-fluid and particle-wall interaction dynamics. These would be of great interest to researchers and scientists interested in fundamental problems relating to the general theory of pattern formation in complex nonlinear multiphase systems.
Improved accuracy of hybrid atomistic/coarse-grained simulations using reparametrised interactions
Authors: Renevey Annick , Riniker Sereina
Published: March 2017

Reducing the number of degrees of freedom in molecular models—so-called coarse-graining—is a popular approach to increase the accessible time scales and system sizes in molecular dynamics simulations. It involves, however, per se a loss of information. In order to retain a high accuracy in the region of interest, hybrid methods that combine two levels of resolution in a single system are an attractive trade-off. Hybrid atomistic (AT)/coarse-grained (CG) simulations have previously been shown to preserve the secondary structure elements of AT proteins in CG water but to cause an artificial increase in intramolecular hydrogen bonds, resulting in a reduced flexibility of the proteins. Recently, it was found that the AT-CG interactions employed in these simulations were too favourable for apolar solutes and not favourable enough for polar solutes. Here, the AT-CG interactions are reparametrised to reproduce the solvation free energy of a series of AT alkanes and side-chain analogues in CG water, while retaining the good mixing behaviour of AT water with CG water. The new AT-CG parameters are tested in hybrid simulations of four proteins in CG water. Structural and dynamic properties are compared to those obtained in fully AT simulations and, if applicable, to experimental data. The results show that the artificial increase of intramolecular hydrogen bonds is drastically reduced, leading to a better reproduction of the structural properties and flexibility of the proteins in atomistic water, without the need for an atomistic solvent layer.
Linear stability study of the resistive ballooning and ion temperature gradient modes using a hybrid formalism in L-mode edge-like plasmas
Authors: Kim J. Y. , Han H. S.
Published: March 2017

Motivated by several recent works suggesting the importance of resistive ballooning mode (RBM) in L-mode edge plasmas, a modeling study is presented on the linear stability of the RBM and its interaction with the ion temperature gradient mode (ITG). A hybrid code is developed and utilized for the study, which solves the gyrokinetic and fluid equations for ions and electrons, respectively. It is shown that the RBM stability has a substantial difference, depending on whether it is driven by the density gradient, electron temperature gradient (ηe), or ion temperature gradient (ηi). The interaction with the ITG also occurs quite differently, depending on the driving force type. The strongest interaction is observed between the density-gradient driven RBM and the ITG, with the RBM being completely stabilized or smoothly transited to the ITG when ηi increases. In contrast, the ηe driven RBM is not connected to the ITG, with a significant difference in their real frequencies. In the relatively large ηi and ηe regime, the ITG and the ηe or ηi driven RBMs can co-exist, with their relative role varying, mainly depending on electron temperature and the ratio between ηe and ηi.
Fatigue mechanism verified using photovoltaic properties of Pb(Zr0.52Ti0.48)O3 thin films
Authors: Wu Ming , Li Wei , Li Junning , Wang Shaolan , Li Yaqi , Peng Biaolin , Huang Haitao , Lou Xiaojie
Published: March 2017

The photovoltaic effect and its evolution during electrical fatigue in Pb(Zr0.52Ti0.48)O3 (PZT) thin films have been investigated. It is found that the photovoltaic effect of the as-grown PZT thin film is highly affected by the asymmetric Schottky barriers, which can be tuned by applying an external electric field. During fatigue processes, both open-circuit voltage (Voc) and short-circuit current (Jsc) decrease considerably with the increase of the number of electrical cycles. This phenomenon could be ascribed to the degradation of the interfacial layer between the thin film and the electrode induced by highly energetic charge carriers injected from the electrode during bipolar cycling. Our work sheds light on the physical mechanism of both ferroelectric photovoltaics and polarization fatigue in thin-film ferroelectrics.
In situ direct observation of photocorrosion in ZnO crystals in ionic liquid using a laser-equipped high-voltage electron microscope
Authors: Ishioka J. , Kogure K. , Ofuji K. , Kawaguchi K. , Jeem M. , Kato T. , Shibayama T. , Watanabe S.
Published: March 2017

ZnO photocatalysts in water react with environmental water molecules and corrode under illumination. ZnO nanorods in water can also grow because of water splitting induced by UV irradiation. To investigate their morphological behavior caused by crystal growth and corrosion, here we developed a new laser-equipped high-voltage electron microscope and observed crystal ZnO nanorods immersed in ionic liquid. Exposing the specimen holder to a laser with a wavelength of 325 nm, we observed the photocorrosion in situ at the atomic scale for the first time. This experiment revealed that Zn and O atoms near the interface between the ZnO nanorods and the ionic liquid tended to dissolve into the liquid. The polarity and facet of the nanorods were strongly related to photocorrosion and crystal growth.
Environmental impacts and resource use from Australian pork production determined using life cycle assessment. 2. Energy, water and land occupation
Authors: Wiedemann Stephen G. , McGahan Eugene J. , Murphy Caoilinn M.
Published: March 2017

Utilisation of water, energy and land resources is under pressure globally because of increased demand for food, fibre and fuel production. Australian pork production utilises these resources both directly to grow and process pigs, and indirectly via the consumption of feed and other inputs. With increasing demand and higher costs associated with these resources, supply chain efficiency is a growing priority for the industry. This study aimed to quantify fresh water consumption, stress-weighted water use, fossil fuel energy use and land occupation from six case study supply chains and the national herd using a life cycle assessment approach. Two functional units were used: 1 kg of pork liveweight (LW) at the farm-gate, and 1 kg of wholesale pork (chilled, bone-in). At the farm-gate, fresh water consumption from the case study supply chains ranged from 22.2 to 156.7 L/kg LW, with a national average value of 107.5 L/kg LW. Stress-weighted water use ranged from 6.6 to 167.5 L H2O-e /kg LW, with a national average value of 103.2 L H2O-e /kg LW. Fossil fuel energy demand ranged from 12.9 to 17.4 MJ/kg LW, with a national average value of 14.5 MJ/kg LW, and land occupation ranged from 10.9 to 16.1 m2/kg LW, with a national average value of 16.1 m2/kg LW and with arable land representing 97% to 99% of total land occupation. National average impacts associated with production of wholesale pork, including impacts from meat processing, were 184 ± 43 L fresh water consumption, 172 ± 53 L H2O-e stress-weighted water, 27 ± 2.6 MJ fossil fuel energy demand and 25.9 ± 5.5 m2 land/kg wholesale pork. Across all categories through to the wholesale product, resource use was highest from the production of feed inputs, indicating that improving feed conversion ratio is the most important production metric for reducing the resource use. Housing type and energy generation from manure management also influence resource use requirements and may offer improvement opportunities.
Herbage dry-matter yield and nitrogen concentration of grass, legume and herb species grown at different nitrogen-fertiliser rates under irrigation
Authors: Martin Kirsty , Edwards Grant , Bryant Rachael , Hodge Miriam , Moir Jim , Chapman David , Cameron Keith
Published: March 2017

An important goal in dairy systems is to increase production while achieving environmental targets associated with lower nitrate leaching from soils. One approach is to identify forages that grow more at a given level of nitrogen (N) input and result in a lower N intake per kilogram dry matter (DM) consumed. However, while N responses have been well described for perennial ryegrasses, less information is available for alternative grasses, legumes and herbs. In the present study, conducted on the Canterbury Plains, New Zealand, six species (perennial ryegrass, Italian ryegrass, white clover, lucerne, chicory and plantain) were grown at six N-fertiliser rates ranging from 0 to 450 kg N/ha.year and managed under irrigation and cutting management. Herbage DM yield and N concentration were measured over 12 months. As N-fertiliser rate increased from 0 to 450 kg N/ha, annual herbage yield increased linearly (from 4794 to 14 329 kg DM/ha.year in grasses and from 7146 to 13 177 kg DM/ha.year in herbs). In contrast, annual herbage yield for legumes was unaffected by N-fertiliser rate and ranged from 11 874 to 13 112 kg DM/ha. Additionally, there were contrasting responses in herbage N concentration between species. At all N-fertiliser rates, herbage N concentration was highest in legumes (43.4 g N/kg DM), then herbs (30.7 g N/kg DM), and lowest in grasses (25.8 g N/kg DM). The N concentration of legume DM was unaffected by increasing N-fertiliser rate, whereas in grasses and herbs it increased. Results suggested that there were no benefits in using herbs instead of grasses for reducing N intake in livestock in an irrigated Canterbury environment.
Using ultrasound to derive new reproductive traits in tropical beef breeds: implications for genetic evaluation
Authors: Corbet N. J. , Allen J. M. , Laing A. R. , Fordyce G. , McGowan M. R. , Burns B. M.
Published: March 2017

Key components of female fertility in tropically adapted beef breeds are age at puberty and interval from calving to conception. Presence of an ovarian corpus luteum or stage of pregnancy were recorded using trans-rectal ultrasonography in 4649 heifers and 2925 first-lactation cows in seven herds of either Brahman, Droughtmaster or Santa Gertrudis tropical beef cattle breeds in northern Australia. The traits derived from a single ultrasonographic examination were incidence of corpus luteum at ~600 days of age in heifers, and weeks pregnant 5 weeks post-mating in heifers at ~2.5 years of age and in first-lactation cows at either 2.5 or 3.5 years of age. At 600 days of age, the bodyweight of heifers averaged 340 kg and 40% had a corpus luteum. At 2.5 years of age bodyweight of heifers averaged 452 kg and 80% were pregnant. First-lactation cows averaged 473 kg and 64% were pregnant. Considerable between-herd variation in traits reflected differences in climate and management at each site. However, estimates of heritability of incidence of corpus luteum at 600 days (0.18–0.32) and weeks pregnant in lactating cows (0.11–0.20) suggested that a significant proportion of the variation was due to additive gene action. Small to moderate genetic correlations with other economically important traits and the range in estimated breeding values indicate substantial opportunity for genetic improvement of the traits. The study provided evidence to accept the hypothesis that strategically timed ultrasound examinations can be adopted to derive useful traits for genetic evaluation.
Diurnal variation in urine nitrogen and creatinine concentrations from lactating cows grazing ryegrass-dominant pasture in autumn and late spring–summer
Authors: Cosgrove G. P. , Jonker A. , Lowe K. A. , Taylor P. S. , Pacheco D.
Published: March 2017

In dairy production systems based on grazed pasture, urine patches are the main source of nitrogen (N) losses via leaching and gaseous emission pathways. The volume and N concentration of urine influences the amount of N in a urine patch. We conducted systematic urine sampling to determine the diurnal variation in concentrations of N and creatinine (a proxy for urine volume), and the N : creatinine ratio, to identify the sampling required for accurately estimating the daily mean concentrations of N and creatinine. Nine groups (n = 6) of multiparous Friesian and Friesian × Jersey cows in autumn (220 ± 26 days-in-milk, milked twice daily) and nine groups (n = 6) in late spring–summer (228 ± 24 days-in-milk, milked once daily) were sequentially withdrawn from the farm herd at approximately weekly intervals and each group was offered a fresh allocation of ryegrass-dominant pasture twice daily after milking for 3 days (including at the equivalent time in the afternoon in late spring–summer when they were milked once daily). For each of the 18 different groups of cows, individual urine samples were collected on Day 3 at 1100 hours, 1500 hours (afternoon milking), 1800 hours and 0700 hours (the following morning milking), and, subsequently, analysed for total N and creatinine concentrations. In autumn, urine-N concentrations were higher (P = 0.0002) at 1800 hours (5.8 g N/L) than they were at 1500 hours or 0700 hours (mean of 4.2 g N/L). In late spring–summer, the concentrations were higher (P < 0.001) at 1100 hours (8.0 g N/L) than they were at 1500 hours, 1800 hours or 0700 hours (mean of 6.3 g N/L). The urine N : creatinine ratio was 214 mol/mol in autumn and 148 mol/mol in late spring–summer, but did not vary among sampling times during the day. The highest concentrations of N were in urine samples collected ~3 h post-allocation of fresh feed when cows had grazed actively and consumed the majority of the herbage available. For accurate estimates of the daily mean urine N concentration, sample collections should be timed to encompass this diurnal variation. For the N : creatinine ratio, which was more stable through the day, the timing of sample collection is less important for estimating a daily mean.
Nitrogen nutrients in a subtropical river: temporal variation and analysis at different spatial scales
Authors: Moncayo-Estrada Rodrigo , Escalera-Gallardo Carlos , Arroyo-Damián Miriam , Campos-Campos Oswaldo , Silva-García José T.
Published: March 2017

Herein we provide a framework for evaluating the spatiotemporal variation of nitrate and ammonium and their relationships with environmental and anthropogenic variables at different scales. Bimonthly samples were collected from 28 sites in the Duero River, Mexico, from May to December 2013. The river flow changed and lost connectivity during the dry season because more water was diverted for irrigation. Four sites had the highest nitrate and ammonium values (7.6 and 22.1mgL–1 respectively), which were related to direct waste water discharge. The remaining 24 sites were analysed using a multivariate approach. Using hierarchical cluster analysis, seasonal trends were identified with two groupings during July and five in December. Sites were grouped into those with constant discharge and nitrates affected by springs and those with poor water quality (high concentrations of ammonium). Non-metric multidimensional scaling simultaneously revealed the variation in time and space, organised sites into an environmental ammonium gradient and differentiated between seasons according to nitrate levels. Regression tree analysis established a relationship between nutrients and independent variables. At the landscape level, the agricultural area affected nitrate (75%) and urban area affected ammonium (45%); at the basin level, road density influenced both parameters (10.68km per 25km2).