bluuebunny/crossref_metadata_2025 huggingface dataset:
The evolution of 17O-excess in surface water of the arid environment during recharge and evaporation
Authors: Surma J. , Assonov S. , Herwartz D. , Voigt C. , Staubwasser M.
Published: March 2018

This study demonstrates the potential of triple O-isotopes to quantify evaporation with recharge on a salt lake from the Atacama Desert, Chile. An evaporative gradient was found in shallow ponds along a subsurface flow-path from a groundwater source. Total dissolved solids (TDS) increased by 177 g/l along with an increase in δ18O by 16.2‰ and in δD by 65‰. 17O-excess decreased by 79 per meg, d-excess by 55‰. Relative humidity (h), evaporation over inflow (E/I), the isotopic composition of vapor (*RV) and of inflowing water (*RWI) determine the isotope distribution in 17O-excess over δ18O along a well-defined evaporation curve as the classic Craig-Gordon model predicts. A complementary on-site simple (pan) evaporation experiment over a change in TDS, δ18O, and 17O-excess by 392 g/l, 25.0‰, and −130 per meg, respectively, was used to determine the effects of sluggish brine evaporation and of wind turbulence. These effects translate to uncertainty in E/I rather than h. The local composition of *RV relative to *RWI pre-determines the general ability to resolve changes in h. The triple O-isotope system is useful for quantitative hydrological balancing of lakes and for paleo-humidity reconstruction, particularly if complemented by D/H analysis.
Cardiogenic Airflow in the Lung Revealed Using Synchrotron-Based Dynamic Lung Imaging
Authors: Dubsky Stephen , Thurgood Jordan , Fouras Andreas , R. Thompson Bruce , Sheard Gregory J.
Published: March 2018

The beating heart is known to produce pressure and airflow oscillations in the lungs of mammals. This phenomenon is often disregarded as detailed measurement of its effects in the lung have hitherto not been possible. Previous studies have attempted to measure the effect of these oscillations on gas mixing. However, the results have proven inconclusive, due to the lack of a direct measurement tool capable of flow measurement throughout the entire bronchial tree. Here we present the first detailed measurement of cardiogenic oscillations, using synchrotron-based dynamic lung imaging of live mechanically ventilated mice. The results demonstrate large flow oscillations and pendelluft in the airways due to the mechanical action of the beating heart. Using a virtual tracer modelling analysis we show that cardiogenic oscillations produced up to 4 times increased gas mixing, but only in the absence of tidal ventilation. The results highlight the importance of considering this often-disregarded phenomenon when investigating lung function, particularly in situations where tidal ventilation is reduced or absent.
Photobiont switching causes changes in the reproduction strategy and phenotypic dimorphism in the Arthoniomycetes
Authors: Ertz Damien , Guzow-Krzemińska Beata , Thor Göran , Łubek Anna , Kukwa Martin
Published: March 2018

Phylogenetic analyses using mtSSU and nuITS sequences of Buellia violaceofusca (previously placed in Lecanoromycetes), a sterile, sorediate lichen having a trebouxioid photobiont, surprisingly prove that the species is conspecific with Lecanographa amylacea (Arthoniomycetes), a fertile, esorediate species with a trentepohlioid photobiont. These results suggest that L. amylacea and B. violaceofusca are photomorphs of the same mycobiont species, which, depending on the photobiont type, changes the morphology and the reproduction strategy. This is the first example of a lichenized fungus that can select between Trebouxia (Trebouxiophyceae) and trentepohlioid (Ulvophyceae) photobionts. Trebouxia photobionts from the sorediate morphotype belong to at least three different phylogenetic clades, and the results suggest that Lecanographa amylacea can capture the photobiont of other lichens such as Chrysothrix candelaris to form the sorediate morphotype. Phylogenetic analyses based on rbcL DNA data suggest that the trentepohlioid photobiont of L. amylacea is closely related to Trentepohlia isolated from fruticose lichens. The flexibility in the photobiont choice enables L. amylacea to use a larger range of tree hosts. This strategy helps the lichen to withstand changes of environmental conditions, to widen its distribution range and to increase its population size, which is particularly important for the survival of this rare species.
Probing variable range hopping lengths by magneto conductance in carbonized polymer nanofibers
Authors: Kim Kyung Ho , Lara-Avila Samuel , He Hans , Kang Hojin , Hong Sung Ju , Park Min , Eklöf Johnas , Moth-Poulsen Kasper , Matsushita Satoshi , Akagi Kazuo , Kubatkin Sergey , Park Yung Woo
Published: March 2018

Using magneto transport, we probe hopping length scales in the variable range hopping conduction of carbonized polyacetylene and polyaniline nanofibers. In contrast to pristine polyacetylene nanofibers that show vanishing magneto conductance at large electric fields, carbonized polymer nanofibers display a negative magneto conductance that decreases in magnitude but remains finite with respect to the electric field. We show that this behavior of magneto conductance is an indicator of the electric field and temperature dependence of hopping length in the gradual transition from the thermally activated to the activation-less electric field driven variable range hopping transport. This reveals magneto transport as a useful tool to probe hopping lengths in the non-linear hopping regime.
CISNE: An accurate description of dose-effect and synergism in combination therapies
Authors: García-Fuente Amador , Vázquez Fernando , Viéitez José M. , García Alonso Francisco J. , Martín José I. , Ferrer Jaime
Published: March 2018

The precise determination of dose-effect curves and the combination effect of drugs is of crucial importance in the development of new therapies for the most dreadful diseases. We have found that the current implementations of the theory of Chouet al. are not accurate enough in some circumstances and might lead to erroneous predictions of synergistic or antagonistic behaviour. We have identified the source of inaccuracies and fixed it thereby improving the accuracy of those methods. Here we explain the main features of our approach and demonstrate its higher accuracy as compared to the standard methods. Therefore, this new implementation might have a huge impact in the reliability of future research on new Combination Therapies.
Comorbidities and treatment outcomes in multidrug resistant tuberculosis: a systematic review and meta-analysis
Authors: Samuels Joel Philip , Sood Aashna , Campbell Jonathon R. , Ahmad Khan Faiz , Johnston James Cameron
Published: March 2018

Little is known about the impact of comorbidities on multidrug resistant (MDR) and extensively drug resistant (XDR) tuberculosis (TB) treatment outcomes. We aimed to examine the effect of human immunodeficiency virus (HIV), diabetes, chronic kidney disease (CKD), alcohol misuse, and smoking on MDR/XDRTB treatment outcomes. We searched MEDLINE, EMBASE, Cochrane Central Registrar and Cochrane Database of Systematic Reviews as per PRISMA guidelines. Eligible studies were identified and treatment outcome data were extracted. We performed a meta-analysis to generate a pooled relative risk (RR) for unsuccessful outcome in MDR/XDRTB treatment by co-morbidity. From 2457 studies identified, 48 reported on 18,257 participants, which were included in the final analysis. Median study population was 235 (range 60–1768). Pooled RR of unsuccessful outcome was higher in people living with HIV (RR = 1.41 [95%CI: 1.15–1.73]) and in people with alcohol misuse (RR = 1.45 [95%CI: 1.21–1.74]). Outcomes were similar in people with diabetes or in people that smoked. Data was insufficient to examine outcomes in exclusive XDRTB or CKD cohorts. In this systematic review and meta-analysis, alcohol misuse and HIV were associated with higher pooled OR of an unsuccessful outcome in MDR/XDRTB treatment. Further research is required to understand the role of comorbidities in driving unsuccessful treatment outcomes.
Analysis of Long Term Study Indicates Both Agronomic Optimal Plant Density and Increase Maize Yield per Plant Contributed to Yield Gain
Authors: Assefa Yared , Carter Paul , Hinds Mark , Bhalla Gaurav , Schon Ryan , Jeschke Mark , Paszkiewicz Steve , Smith Stephen , Ciampitti Ignacio A.
Published: March 2018

Concurrent to yield, maize (Zea Mays L.) plant density has significantly increased over the years. Unlike yield, however, the rate of change in plant density and its contribution to maize yield gain are rarely reported. The main objectives of this study were to examine the trend in the agronomic optimum plant density (AOPD) and quantify the contribution of plant density to yield gain. Maize hybrid by seeding rate trials were conducted from 1987–2016 across North America (187,662 data points). Mixed model, response surface, and simple linear regression analyses were applied on the meta-data. New outcomes from this analysis are: (i) an increase in the AOPD at rate of 700 plant ha−1 yr−1, (ii) increase in the AOPD of 1386, 580 and 404 plants ha−1 yr−1 for very high yielding (VHY, > 13 Mg ha−1), high yielding (HY, 10–13 Mg ha−1) and medium yielding (MY, 7–10 Mg ha−1), respectively, with a lack of change for the low yielding (LY, < 7 Mg ha−1) environment; (iii) plant density contribution to maize yield gain ranged from 8.5% to 17%, and (iv) yield improvement was partially explained by changes in the AOPD but we also identified positive impacts on yield components as other sources for yield gain.
Tobacco-Free Cigarette Smoke Exposure Induces Anxiety and Panic-Related Behaviours in Male Wistar Rats
Authors: Chírico Máira Tereza Talma , Bezerra Frank Silva , Guedes Mariana Reis , Souza Ana Beatriz , Silva Fernanda Cacilda , Campos Glenda , de Noronha Sylvana Rendeiro , Mesquita Laura Batista Tavares , Reis Thayane Oliveira , Cangussú Silvia Dantas , Chianca-Jr Deoclécio Alves , de Menezes Rodrigo Cunha
Published: March 2018

Smokers, who generally present with lung damage, are more anxious than non-smokers and have an associated augmented risk of panic. Considering that lung damage signals specific neural pathways that are related to affective responses, the aim of the present study was to evaluate the influence of pulmonary injury on anxiety and panic-like behaviours in animals exposed to cigarette smoke with and without tobacco. Male Wistar rats were divided into the following groups: a control group (CG); a regular cigarette group (RC); and a tobacco-free cigarette (TFC) group. Animals were exposed to twelve cigarettes per day for eight consecutive days. The animals were then exposed to an elevated T-maze and an open field. The RC and TFC groups presented increases in inflammatory cell inflow, antioxidant enzyme activity, and TBARS levels, and a decrease in the GSH/GSSG ratio was observed in the TFC group. Exposure to RC smoke reduced anxiety and panic-related behaviours. On the other hand, TFC induced anxiety and panic-related behaviours. Thus, our results contradict the concept that nicotine is solely accountable for shifted behavioural patterns caused by smoking, in that exposure to TFC smoke causes anxiety and panic-related behaviours.
A narrow open tubular column for high efficiency liquid chromatographic separation
Authors: Chen Huang , Yang Yu , Qiao Zhenzhen , Xiang Piliang , Ren Jiangtao , Meng Yunzhu , Zhang Kaiqi , Juan Lu Joann , Liu Shaorong
Published: March 2018

We report a great feature of open tubular liquid chromatography when it is run using an extremely narrow (e.g., 2 μm inner diameter) open tubular column: more than 10 million plates per meter can be achieved in less than 10 min and under an elution pressure of ca. 20 bar.
Neutron diffraction and gravimetric study of the manganese nitriding reaction under ammonia decomposition conditions
Authors: Wood Thomas J. , Makepeace Joshua W. , David William I. F.
Published: March 2018

In situ neutron diffraction of ammonia decomposition over manganese reveals the structures of different nitrides and kinetic information about their formation.
Local structure and hydrogen bond characteristics of imidazole molecules for proton conduction in acid and base proton-conducting composite materials
Authors: Hori Yuta , Chikai Takuma , Ida Tomonori , Mizuno Motohiro
Published: March 2018

Protons in composite materials of acidic polymers and imidazole molecules transport with rotational motion of imidazole in hydrogen bonds.
Degradation of thin-film lithium batteries characterised by improved potentiometric measurement of entropy change
Authors: Zhang Xiao-Feng , Zhao Yan , Liu Hong-Yan , Zhang Teng , Liu Wei-Ming , Chen Mu , Patel Yatish , Offer Gregory J. , Yan Yue
Published: March 2018

Entropy profiling is sensitive to structural changes in the electrodes during cycling, and complementary to other techniques for studying degradation.
Quercetin-3-O-α-l-arabinopyranoside protects against retinal cell death via blue light-induced damage in human RPE cells and Balb-c mice
Authors: Kim Jun , Jin Hong Lan , Jang Dae Sik , Jeong Kwang Won , Choung Se-Young
Published: March 2018

Age-related macular degeneration (AMD) is a chronic degenerative disease that can lead to visual loss and blindness in the elderly.
Enantiopure Schiff bases of amino acid phenylhydrazides: impact of the hydrazide function on their structures and properties
Authors: Bouzayani Nadia , Marque Sylvain , Djelassi Brahim , Kacem Yakdhane , Marrot Jérôme , Ben Hassine Béchir
Published: March 2018

New chiral Schiff bases have been synthesized and characterized with an important contribution from quantum chemical calculations at the DFT level of theory. They have been evaluated for their physical and biological properties.
Triflic acid-catalyzed metal-free synthesis of (E)-2-cyanoacrylamides and 3-substituted azetidine-2,4-diones
Authors: Rupanwar Bapurao D. , Chavan Santosh S. , Shelke Anil M. , Suryavanshi Gurunath M.
Published: March 2018

A TfOH-catalyzed highly efficient synthesis of biologically active (E)-2-cyanoacrylamides and 3-substituted azetidine-2,4-diones has been reported with 64–94% yields under metal-free conditions.
Nanoparticle wrapping at small non-spherical vesicles: curvatures at play
Authors: Yu Qingfen , Othman Sameh , Dasgupta Sabyasachi , Auth Thorsten , Gompper Gerhard
Published: March 2018

Wrapping of nanoparticles that enter and exit vesicles depends on several important parameters, such as particle size and shape, vesicle size and reduced volume, and membrane spontaneous curvature. This implies complex wrapping behavior where particle wrapping transitions and vesicle shape transitions are intimately coupled.
Synthetic glycan-based TLR4 agonists targeting caspase-4/11 for the development of adjuvants and immunotherapeutics
Authors: Adanitsch Florian , Shi Jianjin , Shao Feng , Beyaert Rudi , Heine Holger , Zamyatina Alla
Published: March 2018

The skewed molecular shape of the rigid α,α-(1↔1′)-linked disaccharide core of novel synthetic anionic glycan-based immunostimulants is accountable for potent and adjustable TLR4-mediated signaling which is dissociable from the induction of caspase-11 protease activity.
Microscale mapping of extracellular matrix elasticity of mouse joint cartilage: an approach to extracting bulk elasticity of soft matter with surface roughness
Authors: Chandran Preethi L. , Dimitriadis Emilios K. , Mertz Edward L. , Horkay Ferenc
Published: March 2018

Novel analysis and experimental methodology for extracting bulk elasticity from cartilage sections and other soft materials with surface roughness.
In situ electrochemical electron paramagnetic resonance spectroscopy as a tool to probe electrical double layer capacitance
Authors: Wang Bin , Fielding Alistair J. , Dryfe Robert A. W.
Published: March 2018

In situ electrochemical electron paramagnetic resonance (EPR) spectroscopy is presented as a means to distinguish between purely capacitive and pseudo-capacitive processes in supercapacitors.
Serum amyloid A sequesters diverse phospholipids and their hydrolytic products, hampering fibril formation and proteolysis in a lipid-dependent manner
Authors: Jayaraman Shobini , Gantz Donald L. , Haupt Christian , Fändrich Marcus , Gursky Olga
Published: March 2018

Serum amyloid A can solubilize diverse phospholipids and their hydrolytic products to form lipoprotein nanoparticles, which hampers amyloid fibril formation.
A highly sensitive and selective fluorescent probe for fast sensing of endogenous HClO in living cells
Authors: Zhang Changyu , Nie Qichang , Ismail Ismail , Xi Zhen , Yi Long
Published: March 2018

A highly sensitive and fast-response fluorescent probe for HClO detection was developed and employed to reveal the H2S-induced HClO biogenesis in living cells.
Effective electronic-only Kohn–Sham equations for the muonic molecules
Authors: Rayka Milad , Goli Mohammad , Shahbazian Shant
Published: March 2018

A set of novel effective electronic-only Kohn–Sham equations is derived for the muonic moleulces and implemented computationally on munoiated ferrocene.
Correction: The nanoscale structure of the electrolyte–metal oxide interface
Authors: Steinrück Hans-Georg , Cao Chuntian , Tsao Yuchi , Takacs Christopher J. , Konovalov Oleg , Vatamanu Jenel , Borodin Oleg , Toney Michael F.
Published: March 2018

Correction for ‘The nanoscale structure of the electrolyte–metal oxide interface’ by Hans-Georg Steinrück et al., Energy Environ. Sci., 2018, DOI: 10.1039/c7ee02724a.
The inhibitory effect of Manuka honey on human colon cancer HCT-116 and LoVo cell growth. Part 2: Induction of oxidative stress, alteration of mitochondrial respiration and glycolysis, and suppression of metastatic ability
Authors: Afrin Sadia , Giampieri Francesca , Gasparrini Massimiliano , Forbes-Hernández Tamara Y. , Cianciosi Danila , Reboredo-Rodriguez Patricia , Manna Piera Pia , Zhang Jiaojiao , Quiles Josè L. , Battino Maurizio
Published: March 2018

Manuka honey induces chemopreventive effects.
Stereospecific radiosynthesis of 3-fluoro amino acids: access to enantiomerically pure radioligands for positron emission tomography
Authors: Alluri Santosh R. , Riss Patrick J.
Published: March 2018

A variety of substituted non-racemic aziridine-2-carboxylates equivalent to amino acids were prepared and subjected to ring opening reaction by [18F/19F]fluoride.
Disentanglement of excited-state dynamics with implications for FRET measurements: two-dimensional electronic spectroscopy of a BODIPY-functionalized cavitand
Authors: Otto John P. , Wang Lili , Pochorovski Igor , Blau Samuel M. , Aspuru-Guzik Alán , Bao Zhenan , Engel Gregory S. , Chiu Melanie
Published: March 2018

Two-dimensional electronic spectroscopy of energy transfer and competing dynamics highlights how conformational changes create issues with lifetime-based FRET measurements.
Complex long-term activity of the post-nova X Serpentis
Authors: Šimon V.
Published: March 2018

Aims. X Ser is a cataclysmic variable (CV) which erupted as a classical nova in 1903. In this work we use over 100 years of photometry to characterize the long-term light curve of X Ser, with the aim of interpreting the post-nova activity in X Ser in the context of behaviors in other old novae.

Methods. This analysis of its long-term optical activity uses the data from the Digital Access to a Sky Century @ Harvard (DASCH), AAVSO, and Catalina Real-time Transient Survey databases, supplemented by the data of other authors.

Results. We show that X Ser displays a strong complex activity with the characteristics of various CV types after the return to quiescence from its classical nova outburst. Both nova-like and dwarf nova (DN) features are present. The decaying branches of the individual post-nova outbursts display large mutual similarities and obey the Bailey law for outbursts of DNe. These outbursts of X Ser constitute a uniform group (inside-out outbursts), and their decaying branches can be explained by propagation of cooling front through the accretion disk. In the interpretation, X Ser rapidly transitioned to a thermal-viscous instability regime of the disk, initially only intermittently. The occurrence of the DN outbursts shortly after the end of the nova outburst suggests that the mass transfer rate into the disk was usually not sufficiently high to prevent a thermal-viscous instability of this post-nova. The very long orbital period, and hence large accretion disk of X Ser can contribute to this.
A Virgo Environmental Survey Tracing Ionised Gas Emission (VESTIGE)
Authors: Boselli A. , Fossati M. , Cuillandre J. C. , Boissier S. , Boquien M. , Buat V. , Burgarella D. , Consolandi G. , Cortese L. , Côté P. , Côté S. , Durrell P. , Ferrarese L. , Fumagalli M. , Gavazzi G. , Gwyn S. , Hensler G. , Koribalski B. , Roediger J. , Roehlly Y. , Russeil D. , Sun M. , Toloba E. , Vollmer B. , Zavagno A.
Published: March 2018

During pilot observations of the Virgo Environmental Survey Tracing Galaxy Evolution (VESTIGE), a blind narrow-band Hα + [NII] imaging survey of the Virgo cluster carried out with MegaCam at the CFHT, we have observed the spiral galaxy NGC 4254 (M99). Deep Hα + [NII] narrow-band and GALEX UV images reveal the presence of 60 compact (70–500 pc radius) star-forming regions up to ≃20 kpc outside the optical disc of the galaxy. These regions are located along a tail of HI gas stripped from the disc of the galaxy after a rapid gravitational encounter with another Virgo cluster member that simulations indicate occurred 280–750 Myr ago. We have combined the VESTIGE data with multifrequency data from the UV to the far-infrared to characterise the stellar populations of these regions and study the star formation process in an extreme environment such as the tails of stripped gas embedded in the hot intracluster medium. The colour, spectral energy distribution (SED), and linear size consistently indicate that these regions are coeval and have been formed after a single burst of star formation that occurred ≲100 Myr ago. These regions might become free floating objects within the cluster potential well, and be the local analogues of compact sources produced after the interaction of gas-rich systems that occurred during the early formation of clusters.
Tödliche Blutung aus einer tracheo-aortalen Fistel – seltene iatrogene Komplikation
Authors: Lang Juliane , Birngruber Christoph , Dettmeyer Reinhard
Published: March 2018

Berichtet wird über eine weder vorhersehbare noch beherrschbare letale Komplikation bei liegender Trachealkanüle. Nach Anlage eines Tracheostoma entwickelte sich eine nekrotisierend-fistelnde Entzündung zwischen der Trachea und der Aorta. Als Folge einer Arrosion der Aortenwand kam es zu einer tödlichen Blutung in die Lichtung der Trachea und des Bronchialbaums mit tiefer Blutaspiration.
Reizdarmsyndrom – eine Krankheit
Authors: Andresen Viola , Layer Peter
Published: March 2018

The irritable bowel syndrome (IBS) counts among the most prevalent chronic diseases. Clinically, the IBS is characterized by abdominal symptoms combined with irregular defecation, which are not explained by routine diagnostic tests. IBS is often triggered by enteric bacterial infections, and its pathogenesis involves disturbed enteric, gut-brain, and cerebral mechanisms. Diagnostic work-up must aim to establish a positive IBS diagnosis, and to exclude serious underlying differential diagnoses (such as neoplasia, inflammatory bowel disease, celiac disease and others). On the other hand, it is important to avoid diagnostic “overkill” including repetitive testing. Successful treatment of IBS usually combines unspecific basic (nutritional, psychological, lifestyle etc.) measures with specific, symptom-oriented medical therapy. Therapeutic efficacy is greatly enhanced by ruling out worrying diagnostic uncertainties (reassurance), and by initiating positive patient guidance.
Seltener klinischer Fall eines Dünndarm-Ileus in Folge eines invaginierten Meckel’schen Divertikels
Authors: Schadow Claudia , Schmidt Hanna , Schorcht Alexander , Meyer Frank
Published: March 2018

Anamnese und klinischer Befund Aufnahme eines 43-jährigen Patienten mit seit 2 Tagen bestehenden diffusen abdominellen Beschwerden anamnestisch (epigastrischer Beginn; keine abdominellen Voroperationen).

Untersuchungen Gastroskopie und Abdomensonografie erbrachten nur eine geringgradige Gastritis, laborchemisch lediglich leichtgradige Leukozytose (10 610/µl). Nach 24 h klinischer Beobachtung bereits zunehmende Ileus-Symptomatik mit progredient geblähtem Abdomen, klingenden Darmgeräuschen und rezidivierendem, teils stuhligem Erbrechen. CT: intraluminaler Ileumtumor. Chirurgisch wurde die OP-Indikation gestellt.

Diagnose Dringender Verdacht auf mechanischen Ileus aufgrund eines obstruierenden Dünndarmtumors mit geplanter frühelektiver Operation.

Therapie In der Unterbauchlaparotomie Invagination im terminalen Ileum – nach Devagination wurde ein invaginiertes Meckel’sches Divertikel eruiert. Dieses wurde „wandbündig“ reseziert und das Ileum quer vernäht.

Verlauf Postoperativ unauffällig.

Folgerung Ein invaginiertes Meckel’sches Divertikel gehört zu den seltenen Ursachen für einen Dünndarm-Ileus bzw. ein unklares/akutes Abdomen beim Erwachsenen. Diese Ileus-Ursache sollte jedoch bei nicht voroperierten erwachsenen Patienten mit – wenn auch selten – in Betracht gezogen werden.
Non-covalent interactions across organic and biological subsets of chemical space: Physics-based potentials parametrized from machine learning
Authors: Bereau Tristan , DiStasio Robert A. , Tkatchenko Alexandre , von Lilienfeld O. Anatole
Published: March 2018

Classical intermolecular potentials typically require an extensive parametrization procedure for any new compound considered. To do away with prior parametrization, we propose a combination of physics-based potentials with machine learning (ML), coined IPML, which is transferable across small neutral organic and biologically relevant molecules. ML models provide on-the-fly predictions for environment-dependent local atomic properties: electrostatic multipole coefficients (significant error reduction compared to previously reported), the population and decay rate of valence atomic densities, and polarizabilities across conformations and chemical compositions of H, C, N, and O atoms. These parameters enable accurate calculations of intermolecular contributions—electrostatics, charge penetration, repulsion, induction/polarization, and many-body dispersion. Unlike other potentials, this model is transferable in its ability to handle new molecules and conformations without explicit prior parametrization: All local atomic properties are predicted from ML, leaving only eight global parameters—optimized once and for all across compounds. We validate IPML on various gas-phase dimers at and away from equilibrium separation, where we obtain mean absolute errors between 0.4 and 0.7 kcal/mol for several chemically and conformationally diverse datasets representative of non-covalent interactions in biologically relevant molecules. We further focus on hydrogen-bonded complexes—essential but challenging due to their directional nature—where datasets of DNA base pairs and amino acids yield an extremely encouraging 1.4 kcal/mol error. Finally, and as a first look, we consider IPML for denser systems: water clusters, supramolecular host-guest complexes, and the benzene crystal.
Genarris: Random generation of molecular crystal structures and fast screening with a Harris approximation
Authors: Li Xiayue , Curtis Farren S. , Rose Timothy , Schober Christoph , Vazquez-Mayagoitia Alvaro , Reuter Karsten , Oberhofer Harald , Marom Noa
Published: March 2018

We present Genarris, a Python package that performs configuration space screening for molecular crystals of rigid molecules by random sampling with physical constraints. For fast energy evaluations, Genarris employs a Harris approximation, whereby the total density of a molecular crystal is constructed via superposition of single molecule densities. Dispersion-inclusive density functional theory is then used for the Harris density without performing a self-consistency cycle. Genarris uses machine learning for clustering, based on a relative coordinate descriptor developed specifically for molecular crystals, which is shown to be robust in identifying packing motif similarity. In addition to random structure generation, Genarris offers three workflows based on different sequences of successive clustering and selection steps: the “Rigorous” workflow is an exhaustive exploration of the potential energy landscape, the “Energy” workflow produces a set of low energy structures, and the “Diverse” workflow produces a maximally diverse set of structures. The latter is recommended for generating initial populations for genetic algorithms. Here, the implementation of Genarris is reported and its application is demonstrated for three test cases.
Probabilistic performance estimators for computational chemistry methods: The empirical cumulative distribution function of absolute errors
Authors: Pernot Pascal , Savin Andreas
Published: March 2018

Benchmarking studies in computational chemistry use reference datasets to assess the accuracy of a method through error statistics. The commonly used error statistics, such as the mean signed and mean unsigned errors, do not inform end-users on the expected amplitude of prediction errors attached to these methods. We show that, the distributions of model errors being neither normal nor zero-centered, these error statistics cannot be used to infer prediction error probabilities. To overcome this limitation, we advocate for the use of more informative statistics, based on the empirical cumulative distribution function of unsigned errors, namely, (1) the probability for a new calculation to have an absolute error below a chosen threshold and (2) the maximal amplitude of errors one can expect with a chosen high confidence level. Those statistics are also shown to be well suited for benchmarking and ranking studies. Moreover, the standard error on all benchmarking statistics depends on the size of the reference dataset. Systematic publication of these standard errors would be very helpful to assess the statistical reliability of benchmarking conclusions.
Electronic states of Ca/PC61BM: Mechanism of low work function metal as interfacial material
Authors: Du Ying-Ying , Chen Guang-Hua , Li Wen-Jie , Bai Xin-Yuan , Lin De-Qu , Ju Huanxin , Hu Shanwei , Xu Qian , Wang Yan , Li Xiong , Zhu Junfa , Li Hong-Nian
Published: March 2018

We have studied the electronic states at Ca/PC61BM interface using photoemission spectroscopy. It is found that the state of unoccupied molecular orbitals of the top molecular layer (TML) becomes occupied by the electrons transferred from the Ca atoms. The work function of the heavily doped TML of PC61BM film is smaller than that of metal Ca, and thus the contact between the TML and metal Ca is Ohmic. A transition layer (TL) of several molecular layers forms beneath the TML due to the diffusion of the Ca atoms. The TL is conductive and aligns its Fermi level with the negative integer charge transfer level of the interior PC61BM. The built-in electric field in the TL facilitates the electron transport from the interior of the PC61BM film to the TML.
Nucleation study for an undercooled melt of intermetallic NiZr
Authors: Kobold R. , Kolbe M. , Hornfeck W. , Herlach D. M.
Published: March 2018

Electrostatic levitation is applied in order to undercool liquid glass forming NiZr significantly below its melting temperature. For NiZr large undercoolings are found to be highly reproducible with this experimental method. One single NiZr sample of high purity is undercooled 200 consecutive times which leads to a distribution function of undercooling temperatures. Within a statistical approach of classical nucleation theory, the undercooling distribution is analyzed yielding parameters, e.g., a pre-exponential factor of KV ≈ 1035 m−3 s−1, which indicates homogeneous nucleation. This result is consistent with the crystallization behavior of NiZr at high undercooling and with the corresponding microstructural analysis. Since NiZr is a representative of the very common CrB structure type, with 132 isostructural phases existing, understanding its nucleation behavior adds important knowledge to the nucleation of binary alloys in general.
Blind system identification of two-thermocouple sensor based on cross-relation method
Authors: Li Yanfeng , Zhang Zhijie , Hao Xiaojian
Published: March 2018

In dynamic temperature measurement, the dynamic characteristics of the sensor affect the accuracy of the measurement results. Thermocouples are widely used for temperature measurement in harsh conditions due to their low cost, robustness, and reliability, but because of the presence of the thermal inertia, there is a dynamic error in the dynamic temperature measurement. In order to eliminate the dynamic error, two-thermocouple sensor was used to measure dynamic gas temperature in constant velocity flow environments in this paper. Blind system identification of two-thermocouple sensor based on a cross-relation method was carried out. Particle swarm optimization algorithm was used to estimate time constants of two thermocouples and compared with the grid based search method. The method was validated on the experimental equipment built by using high temperature furnace, and the input dynamic temperature was reconstructed by using the output data of the thermocouple with small time constant.
Enhancement of slope efficiency and output power in GaN-based vertical-cavity surface-emitting lasers with a SiO2-buried lateral index guide
Authors: Kuramoto Masaru , Kobayashi Seiichiro , Akagi Takanobu , Tazawa Komei , Tanaka Kazufumi , Saito Tatsuma , Takeuchi Tetsuya
Published: March 2018

We have achieved a high output power of 6 mW from a 441 nm GaN-based vertical-cavity surface-emitting laser (VCSEL) under continuous wave (CW) operation, by reducing both the internal loss and the reflectivity of the front cavity mirror. A preliminary analysis of the internal loss revealed an enormously high transverse radiation loss in a conventional GaN-based VCSEL without lateral optical confinement (LOC). Introducing an LOC structure enhanced the slope efficiency by a factor of 4.7, with a further improvement to a factor of 6.7 upon reducing the front mirror reflectivity. The result was a slope efficiency of 0.87 W/A and an external differential quantum efficiency of 32% under pulsed operation. A flip-chip-bonded VCSEL also exhibited a high slope efficiency of 0.64 W/A and an external differential quantum efficiency of 23% for the front-side output under CW operation. The reflectivity of the cavity mirror was adjusted by varying the number of AlInN/GaN distributed Bragg reflector pairs from 46 to 42, corresponding to reflectivity values from 99.8% to 99.5%. These results demonstrate that a combination of internal loss reduction and cavity mirror control is a very effective way of obtaining a high output GaN-based VCSEL.
Thickness driven spin reorientation transition of epitaxial LaCrO3 films
Authors: Park Junho , Kim Dong-Hwan , Lee Doopyo , Ko Kyung-Tae , Hyun Song Jong , Kim Jae-Young , Koo Tae-Yeong , Lee Seung Ran , Park Jae-Hoon
Published: March 2018

We grew fully strained epitaxial LaCrO3 (LCO) films on SrTiO3(001) under layer-by-layer control up to the film thickness of t = 130 nm using a pulsed laser deposition method. The spin axis of the antiferromagnetic LCO film was systematically examined as a function of t by using Cr L2,3-edge x-ray magnetic linear dichroism (XMLD). The XMLD results manifest a spin reorientation transition (SRT) across a transition thickness of tT ∼ 60 nm. This SRT is well explained in terms of two competing magnetic anisotropy energies of the surface/interface (KS) and the LCO film itself (KV).
Independence of surface morphology and reconstruction during the thermal preparation of perovskite oxide surfaces
Authors: Jäger Maren , Teker Ali , Mannhart Jochen , Braun Wolfgang
Published: March 2018

Using a CO2 laser to directly heat the crystals from the back side, SrTiO3 substrates may be thermally prepared in situ for epitaxy without the need for ex-situ etching and annealing. We find that the formation of large terraces with straight steps at 900–1100 °C is independent of the formation of the ideal surface reconstruction for epitaxy, which requires temperatures in excess of 1200 °C to complete. The process may be universal, at least for perovskite oxide surfaces, as it also works, at different temperatures, for LaAlO3 and NdGaO3, two other widely used oxide substrate materials.
Substituent Effects on 13C NMR and 1H NMR Chemical Shifts of CH=N in Multi-substituted Benzylideneanilines
Authors: Cao Chao-tun , Wang Lin-yan , Cao Chen-zhong
Published: March 2018

Fifty-three samples of multi-substituted benzylideneanilines XArCH=NArYs (abbreviated XBAYs) were synthesized and their NMR spectra were determined. An extensional study of substituent effects on the 1H NMR chemical shifts (δH(CH=N)) and 13C NMR chemical shifts (δC(CH=N)) of the CH=N bridging group from di-substituted to multi-substituted XBAYs was made based on a total of 182 samples of XBAYs, together with the NMR data of other 129 samples of di-substituted XBAYs quoted from literatures. The results show that the substituent specific cross-interaction effect parameter (Δ(∑σ)2) plays an important role in quantifying the δC(CH=N) values of XBAYs, but it is negligible for quantifying the δH(CH=N) values; the other substituent parameters also present different influences on the δC(CH=N) and δH(CH=N). On the whole, the contributions of X and Y to the δC(CH=N) of XBAYs are balanced, but the δH(CH=N) values of XBAYs mainly rely on the contributions of X.
Electronic Transport Properties of Spin-Crossover Magnet Fe(II)-N4S2 Complexes
Authors: Du Ming-li , Hu Yu-jie , Huang Jing , Li Qun-xiang
Published: March 2018

Spin-crossover (SCO) magnets can act as one of the most possible building blocks in molecular spintronics due to their magnetic bistability between the high-spin (HS) and low-spin (LS) states. Here, the electronic structures and transport properties through SCO magnet Fe(II)-N4S2 complexes sandwiched between gold electrodes are explored by performing extensive density functional theory calculations combined with non-equilibrium Green's function formalism. The optimized Fe-N and Fe-S distances and predicted magnetic moment of the SCO magnet Fe(II)-N4S2 complexes agree well with the experimental results. The reversed spin transition between the HS and LS states can be realized by visible light irradiation according to the estimated SCO energy barriers. Based on the obtained transport results, we observe nearly perfect spin-filtering effect in this SCO magnet Fe(II)-N4S2 junction with the HS state, and the corresponding current under small bias voltage is mainly contributed by the spin-down electrons, which is obviously larger than that of the LS case. Clearly, these theoretical findings suggest that SCO magnet Fe(II)-N4S2 complexes hold potential applications in molecular spintronics.
Enhanced Viscosity of Poly(acrylamide) Solution in the Presence of Chromium Citrate Triggered by Release of CO2
Authors: Mo Ai-guo , Wang Yu-pu , Liu Yi-kun , Zhou Wan-fu , Zhou Quan , Yasin Akram , Yang Hai-yang
Published: March 2018

Partially hydrolyzed polyacrylamide (HPAM) has been widely used for water shut-off and profile control to enhance oil recovery. Herein, we reported a novel technique by which the crosslinking between HPAM and Cr3+ in aqueous solutions at 60 °C can be delayed effectively. Citric acid was selected as an organic complexing agent of Cr3+ so that the crosslinking between HPAM and Cr3+ can be prevented completely. Due to the decomposition of the bicarbonate (HCO3−) embedded in solution, CO2 released from solution and the pH value of solution increased gradually. The degree of ionization of HPAM and its ability to complex with Cr3+ increased accordingly. When the complexation of Cr3+ with HPAM is stronger than that with citric acid, the viscosity of the HPAM solution increased significantly. Under the closed condition, together with the existence of potassium dihydrogen phosphate (KH2PO4), the release of CO2 was very slow and the condition was highly controlled so that the ionization of HPAM was prevented initially. Furthermore, the hydrogen bonding interactions between HPAM and melamine embedded in solution previously also postponed the ionization of HPAM. As a result, the crosslinking between HPAM and Cr3+ can be delayed for almost one month, completely meeting the requirements for deep water shut-off and profile control to enhance oil recovery.
Bimetallic RuM (M=Co, Ni) Alloy NPs Supported on MIL-110(Al): Synergetic Catalysis in Hydrolytic Dehydrogenation of Ammonia Borane
Authors: Ning Hong-hui , Lu Di , Zhou Li-qun , Chen Meng-huan , Li Yue , Zhou Gao-jian , Peng Wei-wei , Wang Zheng
Published: March 2018

By adjusting various Ru/M (M=Co, Ni) molar ratios, a series of highly dispersed bimetallic RuM alloy nanoparticles (NPs) anchored on MIL-110(Al) have been successfully prepared via a conventional impregnation-reduction method. And they are first used as heterogeneous catalysts for the dehydrogenation reaction of AB at room temperature. The results reveal that the as-prepared Ru1Co1@MIL-110 and Ru1Ni1@MIL-110 exhibit the highest catalytic activities in different RuCo and RuNi molar ratios, respectively. It is worthy of note that the turnover frequency (TOF) values of Ru1 Co1@MIL-110 and Ru1Ni1@MIL-110 catalysts reached 488.1 and 417.1 mol H2 min−1 (mol Ru)−1 and the activation energies (Ea) are 31.7 and 36.0 kJ/mol, respectively. The superior catalytic performance is attributed to the bimetallic synergistic action between Ru and M, uniform distribution of metal NPs as well as bi-functional effect between RuM alloy NPs and MIL-110. Moreover, these catalysts exhibit favorable stability after 5 consecutive cycles for the hydrolysis of AB.
Theories and Applications of Mixed Quantum-Classical Non-adiabatic Dynamics
Authors: Gao Liang-hui , Xie Bin-bin , Fang Wei-hai
Published: March 2018

Electronically non-adiabatic processes are essential parts of photochemical process, collisions of excited species, electron transfer processes, and quantum information processing. Various non-adiabatic dynamics methods and their numerical implementation have been developed in the last decades. This review summarizes the most significant development of mixed quantum-classical methods and their applications which mainly include the Liouville equation, Ehrenfest mean-field, trajectory surface hopping, and multiple spawning methods. The recently developed quantum trajectory mean-field method that accounts for the decoherence corrections in a parameter-free fashion is discussed in more detail.
Fragment questions in Mandarin Chinese
Authors: Wei Ting-Chi
Published: March 2018

This paper argues that fragment question (FQ) in Mandarin Chinese is derived from topic movement and TP deletion, contributing to the growing body of evidence that sentence fragments are syntactically full clauses (Merchant 2004). Structurally, an FQ consists of a topic-like constituent followed by a particlene, which functions as a topic marker and as a constituent question particle simultaneously. The fragment is argued to move to the SpecTopP rather than SpecFocP (Wei 2013), because FQ exhibits topic properties and respects island effects such as the complex NP island and the adjunct island. However, it is insensitive to islands such as the sentential subject island and left branch condition. We propose that the absence of island effect can be attributed to the pied-piping of the entire topic-like island to the SpecTopP. In addition, the proposed analysis not only captures the ineligible FQs caused by intervention effect within the passive structures but also the eligible FQs induced by preposition drop in the language.
Revisiting form typicality of nouns and verbs
Authors: Sharpe Victoria , Marantz Alec
Published: March 2018

Research has shown that, in English, the mapping between a word’s form and its syntactic category is not entirely arbitrary. Though formal differences between lexical categories are subtle, adults are sensitive to them and access this knowledge when retrieving or manipulating grammatical category information. Studies of form typicality have so far exclusively investigated unambiguous (or disambiguated) wordforms. We test the prediction that form typicality also affects visual processing of ambiguous wordforms, with formal features correlating, not with a form’s designation as a particular category, but with a form’s probability of being used as a particular category. Our results indicate that “form discrepancy”, a measure of how well a form’s category usage matches up with its form (i.e. typically nouny forms associated with high probability of usage as a noun), is a significant predictor of lexical decision response time. These data are in line with models in which category is not specified for roots in the lexicon but rather assigned within syntactic or semantic context, and show that distributional information about grammatical category usage is automatically accessed in visual word processing.
Transculturation and Bourdieu’s habitus theory
Authors: Sayols Jesús
Published: March 2018

In the last two decades, Bourdieu’s sociology has provided appropriate tools for examining the work of literary translators through history. However, Bourdieusian approaches to literary translation seem to reproduce a major problem underlying Bourdieu’s theory; namely, a deterministic view of human behaviour. This article, against the alleged incompatibility between sociological approaches and culturalist paradigms, proposes to combine Bourdieu’s sociology with the notion of transculturation borrowed from Latin American cultural studies. The article demonstrates how transculturation helps elucidating the divided and contradictory nature of the habitus, as it was originally formulated by Bourdieu in his early writings on Kabylian society. Data from my previous study on the translational activity of Dai Wangshu in Republican China are used to illustrate how transculturation reveals itself as a valid model for the study of literary translators through history beyond the limitations of a sociologically-informed approach based exclusively on a Bourdieusian perspective.
Microstructure and mechanical properties of a novel refractory AlNbTiZr high-entropy alloy
Authors: Chen W. , Tang Q. H. , Wang H. , Xie Y. C. , Yan X. H. , Dai P. Q.
Published: March 2018

The microstructure and mechanical properties of a novel refractory AlNbTiZr high-entropy alloy (HEA) with a low density of ∼5.85 g cm−3 were investigated after arc melting and homogenisation at 1473 K for 5 h. The as-cast HEA exhibits a single-phase ordered body-centred cubic (B2) structure. A hexagonal Zr5Al3-type second phase is introduced into the HEA through homogenisation treatment, resulting in increase of the yield strength, ultimate compressive strength and fracture strain by 70 MPa, 308 MPa and 9.2%, respectively. These results indicate that the introduction of the hexagonal Zr5Al3-type second phase into the B2 matrix can simultaneously improve the HEA strength and ductility, showing a strength–ductility combination superior to those of most reported refractory HEAs.