bluuebunny/crossref_metadata_2025 huggingface dataset:
Detection of single analyte and environmental samples with silicon nitride nanopores: Antarctic dirt particulates and DNA in artificial seawater
Authors: Niedzwiecki David J. , Chou Yung-Chien , Xia Zehui , Thei Federico , Drndić Marija
Published: March 2020

Nanopore sensing is a powerful tool for the detection of biomolecules. Solid-state nanopores act as single-molecule sensors that can function in harsh conditions. Their resilient nature makes them attractive candidates for taking this technology into the field to measure environmental samples for life detection in space and water quality monitoring. Here, we discuss the fabrication of silicon nitride pores from ∼1.6 to 20 nm in diameter in 20-nm-thick silicon nitride membranes suspended on glass chips and their performance. We detect pure laboratory samples containing a single analyte including DNA, BSA, microRNA, TAT, and poly-D-lys-hydrobromide. We also measured an environmental (mixed-analyte) sample, containing Antarctic dirt provided by NASA Ames. For DNA measurements, in addition to using KCl and NaCl solutions, we used the artificial (synthetic) seawater, which is a mixture of different salts mimicking the composition of natural seawater. These samples were spiked with double-stranded DNA (dsDNA) fragments at different concentrations to establish the limits of nanopore sensitivity in candidate environment conditions. Nanopore chips were cleaned and reused for successive measurements. A stand-alone, 1-MHz-bandwidth Chimera amplifier was used to determine the DNA concentration in artificial seawater that we can detect in a practical time scale of a few minutes. We also designed and developed a new compact nanopore reader, a portable read-out device with miniaturized fluidic cells, which can obtain translocation data at bandwidths up to 100 kHz. Using this new instrument, we record translocations of 400 bp, 1000 bp, and 15000 bp dsDNA fragments and show discrimination by analysis of current amplitude and event duration histograms.
Effect of thermal annealing on the optical and structural properties of (311)B and (001) GaAsBi/GaAs single quantum wells grown by MBE
Authors: Alghamdi Haifa , Gordo Vanessa Orsi , Schmidbauer Martin , Felix Jorlandio F. , Alhassan Sultan , Alhassni Amra , Prando Gabriela Augusta , Coelho-Júnior Horácio , Gunes Mustafa , Galeti Helder Vinicius Avanço , Gobato Yara Galvão , Henini Mohamed
Published: March 2020

The effect of Furnace Annealing (FA) and Rapid Thermal annealing (RTA) on the structural and optical properties of GaAs1 − xBix/GaAs single quantum wells grown on (001) and (311)B substrates by molecular beam epitaxy was investigated. The structural properties were investigated by high-resolution x-ray diffraction (HR-XRD) and Transmission Electron Microscopy. The Bi concentration profiles were determined by simulating the HR-XRD 2θ−ω scans using dynamical scattering theory to estimate the Bi content, lattice coherence, and quality of the interfaces. The Bi composition was found to be similar for both samples grown on (001) and (311)B GaAs substrates. However, the simulations indicate that the Bi composition is not only limited in the GaAsBi quantum well (QW) layer but also extends out of the GaAsBi QW toward the GaAs barrier. Photoluminescence (PL) measurements were performed as a function of temperature and laser power for samples with a nominal Bi composition of 3%. PL spectra showed that (001) and (311)B samples have different peak energies at 1.23 eV and 1.26 eV, respectively, at 10 K. After RTA at 300 °C for 2 min, the PL intensity of (311)B and (001) samples was enhanced by factors of ∼2.5 and 1.75, respectively. However, for the (001) and (311)B FA samples, an enhancement of the PL intensity by a factor of only 1.5 times could be achieved. The enhancement of PL intensity in annealed samples was interpreted in terms of PL activation energies, with a reduction in the alloy disorder and an increase in the Bi cluster.
Finding acceptable parameter regions of stochastic Hill functions for multisite phosphorylation mechanism
Authors: Chen M. , Ahmadian M. , Watson L. T. , Cao Y.
Published: March 2020

Multisite phosphorylation plays an important role in regulating switch-like protein activity and has been used widely in mathematical models. With the development of new experimental techniques and more molecular data, molecular phosphorylation processes emerge in many systems with increasing complexity and sizes. These developments call for simple yet valid stochastic models to describe various multisite phosphorylation processes, especially in large and complex biochemical networks. To reduce model complexity, this work aims at simplifying the multisite phosphorylation mechanism by a stochastic Hill function model. Furthermore, this work optimizes regions of parameter space to match simulation results from the stochastic Hill function with the distributive multisite phosphorylation process. While traditional parameter optimization methods have been focusing on finding the best parameter vector, in most circumstances, modelers would like to find a set of parameter vectors that generate similar system dynamics and results. This paper proposes a general α–β–γ rule to return an acceptable parameter region of the stochastic Hill function based on a quasi-Newton stochastic optimization algorithm. Different objective functions are investigated characterizing different features of the simulation-based empirical data, among which the approximate maximum log-likelihood method is recommended for general applications. Numerical results demonstrate that with an appropriate parameter vector value, the stochastic Hill function model depicts the multisite phosphorylation process well except the initial (transient) period.
Comments on the rotating magnetocaloric effect: Application to PrSi and HoMn2O5
Authors: de Oliveira N. A. , Caro Patiño J.
Published: March 2020

The rotating magnetocaloric effect, which is an alternative way to cooldown or heat up magnetic materials, is characterized by the isothermal entropy change (ΔSisorot) and adiabatic temperature change (ΔTadrot) in thermodynamic processes upon rotation of the magnetic field. In this paper, we make some comments on the determination of the rotating magnetocaloric quantity ΔSisorot with an application in the real compounds PrSi and HoMn2O5.
Real-space imaging of atomic-scale spin textures at nanometer distances
Authors: Schlenhoff A. , Kovarik S. , Krause S. , Wiesendanger R.
Published: March 2020

Spin-polarized scanning tunneling microscopy (SP-STM) experiments on ultrathin films with non-collinear spin textures demonstrate that resonant tunneling allows for atomic-scale spin-sensitive imaging in real space at tip-sample distances of up to 8 nm. Spin-polarized resonance states evolving between the foremost atom of a magnetic probe tip and the opposed magnetic surface atom are found to provide a loophole from the hitherto existing dilemma of losing spatial resolution when increasing the tip-sample distance in a scanning probe setup. Bias-dependent series of SP-STM images recorded via resonant tunneling reveal spin sensitivity at resonance conditions, indicating that the spin-polarized resonance states act as mediators for the spin contrast across the nm-spaced vacuum gap. With technically feasible distances in the nm regime, resonant tunneling in SP-STM qualifies for a spin-sensitive read-write technique with ultimate lateral resolution in future spintronic applications.
A localized surface acoustic wave applied spatiotemporally controllable chemical gradient generator
Authors: Liang Jingxuan , Chen Keke , Xia Yu , Gui Jinzheng , Wu Zhuhao , Cui Heng , Wu Zezheng , Liu Wei , Zhao Xingzhong , Guo Shishang
Published: March 2020

In many research studies and applications about microscale biochemical analysis, the generation of stable, spatiotemporally controllable concentration gradients is critical and challenging. However, precise adjustment of concentration gradients in microchannels is still a huge challenge. Because of its precise controllability, non-harmfulness, and immediacy, sound waves perfectly meet the needs of this type of problem. Utilizing the acoustofluidic platform to manipulate liquids in the microchannel accurately makes it an excellent solution to this problem. In this work, we present a tunable and reliable acoustofluidic gradient generator, which can trigger a change of medium based on acoustic streaming induced by C-shaped interdigital transducers (IDTs). By locally generating streaming via two C-shaped IDTs in the same direction but at different horizontal positions, concentration generators can produce two streams of liquids step by step, forming a stable and controllable concentration gradient within short response times (approximately second response time). Along with this gradient generator's advantages in size, tunability, and reliability, it could be widely used for micro-biological and micro-chemical applications requiring a precise concentration gradient.
Kinetic features for nucleation-growth process of magnetic phase transition in La(Fe0.88Si0.12)13 compounds
Authors: Fujita A.
Published: March 2020

Non-equilibrium transient features of the nucleation-growth phenomenon were investigated to identify the hysteresis characteristics of a first-order phase transition in La(Fe0.88Si0.12)13 compound. The kinetics in the boundary of the nucleated domains in the matrix of the original phase was investigated in the magnetostatically arrested state at which the domain motion was temporarily arrested by the demagnetizing fields. The response to relatively slow magnetic field changes has a time scale characterized by the dissipation of the locally generated latent heat at the phase boundaries. Applying a faster oscillating field to the arrested boundary results in the appearance of unique responses in which the characteristic time scales are close to the atomic nuclear spin-lattice relaxation time for magnetic elements.
Constructing an Interpenetrated NiII-Based Coordination Polymer Based on a Flexible Dicarboxylate Ligand and an N-Donor Ligand: Preparation, Topological Diversity, and Catalytic Properties
Authors: Guo Feng , Su Changhua , Fan Yuhang , Shi Wenbing
Published: March 2020

A novel coordination polymer (CP) was constructed using 1,3-bis(4-carboxyphenoxy) propane (H2bcp), 1,4-bis(1-imidazol-yl)-2,5-dimethyl benzene (bimb), and NiII ions. [Ni(bcp)(bimb)]·H2O]n (1) shows an interesting 2D+2D → 3D inclined polyrotaxane topology. The structure was characterised by many methods. This work indicates that the flexible and neutral pyridine ligand plays a significant role in constructing CPs. Furthermore, 1 is a highly efficient catalyst for the reaction of CO2 and epoxides.
The potential impact of bacterial communities exposed to crude oil and light on the growth of the harmful algal blooming species Karenia brevis (Dinophyceae)
Authors: Park Bum Soo , Buskey Edward J.
Published: March 2020

Phytoplankton blooms have been occasionally observed to occur after oil spills, and changes in bacterial communities (BC) associated with phytoplankton are known to affect phytoplankton growth. In the present study, to examine the effects of BC exposed to crude oil on phytoplankton blooms, established free-living (FL) BC in Karenia brevis (Dinophyceae) culture were collected and then exposed to crude oil under light or dark conditions. These exposed FL BC were then added to K. brevis culture to investigate the effects on growth rate of this dinoflagellate. Enhanced growth of K. brevis was observed following addition of FL (24.7%) BC exposed to crude oil and light. Whereas BC grown with crude oil in the dark did not enhance growth, and BC without treatment showed a slight growth inhibition (13–15%) of K. brevis. In addition, the growth-promoting effect had a positive correlation with the inoculated bacterial density; the treatment with a higher (~1.5 times) density of FL (42.9%) BC that were exposed to crude oil and light showed an increase in the growth-promoting effect. Taken together, BC exposed to crude oil and light may play an important role in enhancement of K. brevis growth.
Theory of Mind, pragmatics and the brain
Authors: Enrici Ivan , Bara Bruno G. , Adenzato Mauro
Published: March 2020

Theory of Mind(ToM) is a neurocognitive system that allows the perceiver to attribute mental states, such as intentions, beliefs, or feelings, to others’ actions. The aim of the present work is to analyse the engagement of the ToM system in communication, in particular, in communicative intention processing. To this aim, we propose anIntention Processing Network(IPN) with its own principles and mechanisms, that is, a brain network differentially engaged according to the complex intertwining of the context, goal, and action involved. According to our IPN model, a set of brain regions of the ToM system (i.e. left and right temporoparietal junction, precuneus, and medial prefrontal cortex) are differentially involved in comprehending different types of intention, such as private or social intentions. We provide independent and convergent evidence on the role of the IPN model in communicative intention processing and we show that the engagement of the IPN does not depend upon the communicative means used, that is, written language, auditory language, or gesture. Evidence deriving from different experimental paradigms, including neuroimaging, lesion, neurodegenerative, and brain stimulation studies are discussed. In our view, this evidence establishes a link between ToM and pragmatics studies and suggests the role of intention processing as a core feature of human communication.
Effects of hot rolling and homogenisation treatment on low alloy steel ingot
Authors: Baharvand Mahdiyeh , Zanganeh Amir , Mirzadeh Hamed , Habibi Parsa Mohammad
Published: March 2020

The effects of hot rolling and homogenisation treatment on the microstructure and mechanical properties of low-alloy transformation-induced plasticity (TRIP) steel were studied. With increasing the reduction in thickness during rolling, the band spacing and the average ferrite grain size decreased with the consequent enhancement of mechanical properties. Homogenisation treatment resulted in the gradual fading of the banded morphology, more homogeneous microhardness profile, and twice total elongation compared to the as-cast counterpart. The experimentally observed homogenisation time judged by the disappearance of the banded structure was in agreement with the obtained values based on the band spacing and elemental analysis. This work provided scientific evidence for the assumptions used to derive the homogenisation formulae.
Microstructural and mechanical properties of ultra-high-strength dual-phase steel produced by ultra-fast cooling
Authors: Wu Teng , Wu Run , Liu Bin , Liang Wen , Ke Deqing
Published: March 2020

In the present study, grain refinement of Fe–Si–Mn–Nb–B steel was achieved by high reduction hot rolling. Through the following ultra-fast cooling (UFC) and relaxation process, martensite-ferrite complexes with soft phase embedded in the hard phase were prepared. Extremely tiny ferrite grains significantly increased the toughness of the test steel, a large number of big-angle grain boundaries existing in fine martensite lath bundles effectively improved the strength and the strain hardening ability of the investigated material. The test steel with a relaxation time of 6 s shows the best comprehensive performance with a tensile strength of 1473 MPa, an elongation of 15.0%, a low yield ratio of 0.72 and a product of strength and elongation (PSE) of 22.10 GPa%.
Multivalent weak interactions between assembly units drive synaptonemal complex formation
Authors: Zhang Zhenguo , Xie Songbo , Wang Ruoxi , Guo Shuqun , Zhao Qiuchen , Nie Hui , Liu Yuanyuan , Zhang Fengguo , Chen Miao , Liu Libo , Meng Xiaoqian , Liu Min , Zhao Li , Colaiácovo Monica P. , Zhou Jun , Gao Jinmin
Published: March 2020

The synaptonemal complex (SC) is an ordered but highly dynamic structure assembled between homologous chromosomes to control interhomologous crossover formation, ensuring accurate meiotic chromosome segregation. However, the mechanisms regulating SC assembly and dynamics remain unclear. Here, we identified two new SC components, SYP-5 and SYP-6, in Caenorhabditis elegans that have distinct expression patterns and form distinct SC assembly units with other SYPs through stable interactions. SYP-5 and SYP-6 exhibit diverse in vivo SC regulatory functions and distinct phase separation properties in cells. Charge-interacting elements (CIEs) are enriched in SC intrinsically disordered regions (IDRs), and IDR deletion or CIE removal confirmed a requirement for these elements in SC regulation. Our data support the theory that multivalent weak interactions between the SC units drive SC formation and that CIEs confer multivalency to the assembly units.
Electric field strength-dependent accuracy of TiAlN thin film composition measurements by laser-assisted atom probe tomography
Authors: Hans Marcus , Schneider Jochen M
Published: March 2020

Accurate quantification of absolute concentrations represents a major challenge for atom probe tomography (APT) since the field evaporation process is affected significantly by the measurement parameters. In the present work we investigate systematically the effect of laser pulse parameters on the accuracy of laser-assisted APT for a TiAlN thin film previously quantified by ion beam analysis, combining Rutherford backscattering spectrometry and time-of-flight elastic recoil detection analysis. The electric field strength is estimated from the Al2+/Al+ charge state ratio for all systematically varied measurement parameters. Subsequently, the absolute concentrations from laser-assisted APT are compared to ion beam analysis data. An increase of the electric field strength from approximately 25–28 V nm−1 improves the accuracy of absolute concentrations measured by laser-assisted APT from 11.4 to 4.1 at% for N, from 8.8 to 3.0 at% for Al and from 2.8 to 0.9 at% for Ti. Our data emphasize that the measurement accuracy of laser-assisted APT for TiAlN is governed by the electric field strength. It is shown that the smallest compositional discrepancies between ion beam analysis and APT are obtained for the maximum electric field strength of approximately 28 V nm−1 at 10 pJ laser pulse energy. This can be rationalized by considering the enhanced ionization of neutral fragments caused by the increased electric field strength.
Emulating climate extreme indices
Authors: Tebaldi C , Armbruster A , Engler H P , Link R
Published: March 2020

We use simple pattern scaling and time-shift to emulate changes in a set of climate extreme indices under future scenarios, and we evaluate the emulators’ accuracy. We propose an error metric that separates systematic emulation errors from discrepancies between emulated and target values due to internal variability, taking advantage of the availability of climate model simulations in the form of initial condition ensembles. We compute the error metric at grid-point scale, and we show geographically resolved results, or aggregate them as global averages. We use a range of scenarios spanning global temperature increases by the end of the century of 1.5 C and 2.0 C compared to a pre-industrial baseline, and two higher trajectories, RCP4.5 and RCP8.5. With this suite of scenarios we can test the effects on the error of the size of the temperature gap between emulation origin and target scenarios.

We find that in the emulation of most indices the dominant source of discrepancy is internal variability. For at least one index, however, counting exceedances of a high temperature threshold, significant portions of the globally aggregated discrepancy and its regional pattern originate from the systematic emulation error. The metric also highlights a fundamental difference in the two methods related to the simulation of internal variability, which is significantly resized by simple pattern scaling. This aspect needs to be considered when using these methods in applications where preserving variability for uncertainty quantification is important.

We propose our metric as a diagnostic tool, facilitating the formulation of scientific hypotheses on the reasons for the error. In the meantime, we show that for many impact relevant indices these two well established emulation techniques perform accurately when measured against internal variability, establishing the fundamental condition for using them to represent climate drivers in impact modeling.
Analysis of Soil Stability on Steep Slope of Shrub Greening
Authors: Ma Dongliang , Mei Yong , Liu Guoquan
Published: March 2020

The stability of soil sprayed on a steep rock slope is one of the key problems in greening. This paper analyses the stability of soil after shrub greening on a 70 degree steep slope in Luoyang. The calculation results show that the stability of soil will increases with the growth of root system after shrub greening. Field tests show that the soil stability of steep slope has been good after shrub growth for 2 years, which provides a reference of shrub greening design on steep rock slope.
Numerical Simulation of the Effect of Double Hole Dip Angle on Tensile Strength and Failure Characteristics of Red Sandstone
Authors: Dong Hao , Rong Huren , Gu Jingyu
Published: March 2020

In order to study the effect of dip angle on the tensile strength and failure characteristics of red sandstone, based on the results of the Brazilian splitting test for indoor double-hole red sandstone samples, using the PFC2D particle flow numerical simulation technique to simulate the Brazilian splitting test of precast double-hole red sandstone samples, the effect of dip angle on the tensile strength and failure characteristics of red sandstone samples is studied, further, the evolution characteristics of the surface stress field of the double-hole red sandstone specimen during the tension process are analyzed, and the failure mechanism of the red sandstone in the double-hole red sandstone is revealed. The results show: (1) Increasing the inclination angle of the double hole from 0°to 60°the tensile strength of the sample is stepped down, the maximum drop is when the double hole is inclined at 45°;(2)When the double hole inclination angle is 0°-30°, the crack extends through a single hole; when the double hole inclination angle is 45°-60°, the crack propagates through the double hole.(3)The tensile stress concentration zone near the double hole is the main factor affecting the tensile strength and crack propagation of the sample: ① When the tensile stress concentration region at the edge of the hole A and the hole B is not penetrated (0°, 15°, 30°), the tensile strength of the sample is large, when the crack propagates, only a single hole is penetrated; ② When the tensile stress concentration region at the edge of the hole A and the hole B is penetrated (45°, 60°), the tensile strength of the sample is greatly reduced, the double hole is penetrated when the crack propagates.
Stress Evolution Law of Coal and Rock Mass Affected by Mining before and after Dydraulic Fracturing
Authors: Chen Weizhong , Zhong Kun , Zhao Wusheng , Xiao Ziyi , Gao Hou
Published: March 2020

Stress concentration of coal and rock mass is the intrinsic cause of rock burst, the dynamic evolution law of coal seam stress and roof rock stress during the advancing process of mining face is obtained by using the coal seam stress monitoring system and the developed surrounding rock stress monitoring system, In this paper, the stress variation law of coal and rock mass during mining and the correlation between them are analyzed in detail. In order to reduce the danger of rock burst caused by stress concentration, hydraulic fracturing measures of roof strata were adopted in the field, and the stress changes of coal and rock mass before and after hydraulic fracturing were compared and analyzed. The results of the inspection show: The vertical stress gradient is linearly correlated with the trend of coal seam stress. The influence of mining on the stress of rock seam is earlier than that of coal seam, but the influence of mining disturbance on the stress of coal seam is higher than that of rock seam; The increase amplitude of vertical normal stress of roof strata under mining disturbance is obviously higher than that of two horizontal stresses; the stress value of coal and rock strata decreases after hydraulic fracturing, and the decrease amplitude of stress in coal seam is larger than that of rock strata after hydraulic fracturing. The peak stress of coal seam moves toward stopping line than that before hydraulic fracturing. Field application shows that the stress evolution information of coal seam can provide the corresponding basis for anti-scouring measures and ensure the safe and efficient production of working face.
The Comparative Study of Single Pile Bearing Characteristics in Calcareous Sands Foundation and Quartz Sands Foundation Based on Model Experiment
Authors: Yang Chao , Jiang Hao
Published: March 2020

The bearing characteristics of single steel pipe pile in calcareous sands foundation and quartz sands foundation with different relative compactness are compared and analyzed by the model tests of single steel pipe pile in two kinds of soil media in laboratory. The test results show that the bearing behavior of single steel pipe pile is quite different between calcareous sands and quartz sands. Pile end forms of single steel pipe pile have little influence on the bearing capacity, especially in the sands foundation with high relative compactness. Increasing the relative compactness of foundation soil has obvious effect on improving the bearing capacity of single steel pipe pile. But the bearing capacity of single steel pipe pile in calcareous sands is much lower than that in quartz sands in the same relative compactness. The lateral friction resistance of single steel pipe pile in quartz sands is much larger than that of calcareous sands. The lateral friction resistance of single steel pipe pile in calcareous sands does not increase significantly with the increase of relative compactness; But the lateral friction resistance of single steel pipe pile in quartz sands increases significantly with the increase of relative compactness. In calcareous sands foundation, the ratio of load sharing on the side of single steel pipe pile is small, and the load on the pile top is mainly borne by the soil at the pile end, and it is manifested as friction end bearing pile. In the quartz sands foundation, the axial force of the pile decreases rapidly along the pile. And the faster the axial force of the single pile of the steel pipe is decayed with the smaller compactness of the quartz sands..
Study on Application of Manganese Zinc Soft Magnetic Concrete Composite Materials
Authors: Chen Yingjie , Dong Jingbo , Cui Peng , Wang Chao
Published: March 2020

The high heat problem caused by the ferromagnetic effect of traditional large transformer is urgently needed to be solved. Therefore, we need to develop new material large transformers to solve this problem. In the experiment, we measured hysteresis curve and temperature rise rate of the cement base manganese zinc composite materials. In addition, the application performance and transformer ratio of the composite transformer are studied experimentally, and the output voltage of the composite transformer is calculated. By analyzing the experimental data, the manganese zinc soft magnetic concrete composite material can be used in the transformer completely, and can effectively improve the transformer high temperature problem, which extends the new ideas for development of new type transformer.
The Strength and Microstructure Properties of Oil Well Cement with Halloysite Nanotube
Authors: Liu Huiting , Xu Ming , Zhang Zhengrong , Liu Shuoqiong , Zhang Hua , Zhang Chi , Fu Jiawen , Cong Mi , Li Zhifang
Published: March 2020

Halloysite nanotube has attracted more and more attention to reinforce cement for its excellent physical properties and chemical composition. In this study, effects of halloysite nanotube on compressive strength, flexural strength, micro-structure and hydration products of oil well cement were investigated. The results show that the compressive and flexural strength of cement with 3% halloysite nanotube was increased by 35.2% and 38.5%, and the porosity decreased by 14.95%, respectively. Based on the results of SEM and MIP, the following conclusions can be obtained. Halloysite nanotube promoted the hydration process because of its high surface area, filled in the pores of hardened cement paste for the nano size and expansion process, and formed cross-linking structure for the tube-like appearance, all of which lead to denser micro-structure and better strength performance of oil well cement eventually.
Study on Evacuation Safety Rate of Emergency Exits in Railway Tunnel Fire Mode
Authors: Li Qi , Shi Huan , Yang Chang
Published: March 2020

Emergency exit is the most common form of engineering structure in railway tunnel disaster prevention and rescue facilities. In order to clarify the safety guarantee rate of personnel evacuation through emergency exit after fire in railway tunnel, with the help of fire dynamics simulation (FDS) and building-EXODUS, this paper has established the fire combustion model and personnel evacuation model of the 25-type passenger trains in the 3D tunnel. Simultaneously, combined with the personnel safety evacuation criteria, the safety probability of evacuation of personnel in different scenarios at the emergency exit of the railway tunnel fire mode is obtained. The conclusion shows that the larger the width of the running surface, the smaller the total number of evacuation, the higher the evacuation safety rate. The evacuation person number is 2145 (the hard seat is overloaded 60%), and the width of the running surface is increased from 1.5m (standardized value) to 3.5m, the evacuation safety rate increased from 86.4% to 87.7%. The width of the running surface was 1.5m, and the number of evacuation person was 1531 (not overloaded), the evacuation safety rate reached 100%. Therefore, for the 25-type passenger train, if the personnel are not overloaded, they can choose to evacuate the fire at the emergency exit.
Research on Vibration Propagation Characteristics of Tunnel-Stratum System Based on Vibration Exciter Test in Tunnel
Authors: Wu Zongzhen , Zhang Shenglong , Wang Wenbin , Ma Meng
Published: March 2020

The pulse vibration excitation experiment is carried out in the tunnel with a depth of 18m by using the automatic drop-weight excitation device. The vertical vibration acceleration is measured at 15 measuring points with equal spacing on the ground surface. The time history, the frequency spectrum of the tunnel-stratigraphic system under pulse excitation and the propagation law and attenuation characteristics in the octave is studied. The results show that: (1) the transmission loss of vibration acceleration at the measurement point from the tunnel wall to the surface at 0m is above 35dB, and the soil has a strong attenuation effect on the vibration wave propagation; (2) there is an obvious ground vibration amplification area at the 20∼ 25m on the ground, and the amplification area appears at the place where the horizontal distance between the surface measurement point and the tunnel is almost the same as the buried depth. (3) With the increase of frequency, the vibration spectrum and frequency response function curve show “fluctuation reduction” form; (4) As the horizontal distance increases, the vibration energy attenuation of the frequency band below 10 Hz decreases, and the frequency band above 10 Hz exhibits obvious vibration energy attenuation.
Key Technology of Reverse Excavation at Tunnel Portal
Authors: Wang Yuwen , Hu Zhao , Xie Yongli , Wang Chao , Hua Kaicheng , Lai Jinxing , Lai Hongpeng , Wang Yaqiong , Yue Xiabing
Published: March 2020

Tunnel portal construction is often from the outside to the inside of the mountain. Under special conditions and requirements, it is necessary to construct from the inside to the outside of the mountain. The method is called reverse excavation in tunnel portal. To ensure the construction safety in reverse excavation, the stress and deformation characteristics of both forward excavation methods and reverse excavation methods were studied by numerical analysis. The results show that reverse excavation could not significantly increase the deformation and stress of surrounding rock, and even reduced the influence range of tunnel excavation on the stress and deformation of slope. Reverse excavation could also reduce the damage to the portal environment. When the tunnel was about to be cut through, in order to reduce the stress concentration on the slope, the final excavation length was recommended to being greater than 2.5 m. Reverse excavation was a kind of green construction.
Shortening binary complexes and commutativity of K-theory with infinite products
Authors: Kasprowski Daniel , Winges Christoph
Published: March 2020

We show that in Grayson’s model of higher algebraic K-theory using binary acyclic complexes, the complexes of length two suffice to generate the whole group. Moreover, we prove that the comparison map from Nenashev’s model for

K
1

K_1

to Grayson’s model for

K
1

K_1

is an isomorphism. It follows that algebraic

K
K

-theory of exact categories commutes with infinite products.
Implicitization of tensor product surfaces via virtual projective resolutions
Authors: Duarte Eliana , Seceleanu Alexandra
Published: March 2020

We derive the implicit equations for certain parametric surfaces in three-dimensional projective space termed tensor product surfaces. Our method computes the implicit equation for such a surface based on the knowledge of the syzygies of the base point locus of the parametrization by means of constructing an explicit virtual projective resolution.
Involution on pseudoisotopy spaces and the space of nonnegatively curved metrics
Authors: Bustamante Mauricio , Farrell Francis , Jiang Yi
Published: March 2020

We prove that certain involutions defined by Vogell and Burghelea-Fiedorowicz on the rational algebraic

K
K

-theory of spaces coincide. This gives a way to compute the positive and negative eigenspaces of the involution on rational homotopy groups of pseudoisotopy spaces from the involution on rational

S

1

S^{1}

-equivariant homology groups of the free loop space of a simply-connected manifold. As an application, we give explicit dimensions of the open manifolds

V
V

that appear in Belegradek-Farrell-Kapovitch’s work for which the spaces of complete nonnegatively curved metrics on

V
V

have nontrivial rational homotopy groups.
VII—Spinoza’s Unquiet Acquiescentia
Authors: Douglas Alexander X
Published: March 2020

For Spinoza, the highest thing we can hope for is acquiescentia in se ipso—acquiescence in oneself. As an ethical ideal, this might appear as a complacent quietism, a licence to accept the way you are and give up hope of improving either yourself or the world. I argue that the opposite is the case. Self-acquiescence in Spinoza’s sense is a very challenging goal: it requires a form of self-understanding that is extremely difficult to attain. It also involves occupying a daring and radical political position, one that obstructs the psychological mechanisms by which political power is typically maintained.
Disease characterization using a partial correlation-based sample-specific network
Authors: Huang Yanhong , Chang Xiao , Zhang Yu , Chen Luonan , Liu Xiaoping
Published: March 2020

A single-sample network (SSN) is a biological molecular network constructed from single-sample data given a reference dataset and can provide insights into the mechanisms of individual diseases and aid in the development of personalized medicine. In this study, we proposed a computational method, a partial correlation-based single-sample network (P-SSN), which not only infers a network from each single-sample data given a reference dataset but also retains the direct interactions by excluding indirect interactions (https://github.com/hyhRise/P-SSN). By applying P-SSN to analyze tumor data from the Cancer Genome Atlas and single cell data, we validated the effectiveness of P-SSN in predicting driver mutation genes (DMGs), producing network distance, identifying subtypes and further classifying single cells. In particular, P-SSN is highly effective in predicting DMGs based on single-sample data. P-SSN is also efficient for subtyping complex diseases and for clustering single cells by introducing network distance between any two samples.
Increased perception-action binding in Tourette syndrome
Authors: Kleimaker Maximilian , Takacs Adam , Conte Giulia , Onken Rebecca , Verrel Julius , Bäumer Tobias , Münchau Alexander , Beste Christian
Published: March 2020

Gilles de la Tourette syndrome is a multifaceted neurodevelopmental disorder characterized by multiple motor and vocal tics. Research in Tourette syndrome has traditionally focused on the motor system. However, there is increasing evidence that perceptual and cognitive processes play a crucial role as well. Against this background it has been reasoned that processes linking perception and action might be particularly affected in these patients with the strength of perception-action binding being increased. However, this has not yet been studied experimentally. Here, we investigated adult Tourette patients within the framework of the ‘Theory of Event Coding’ using an experimental approach allowing us to directly test the strength of perception-action binding. We included 24 adult patients with Tourette syndrome and n = 24 healthy control subjects using a previously established visual-motor event file task with four levels of feature overlap requiring repeating or alternating responses. Concomitant to behavioural testing, EEG was recorded and analysed using temporal signal decomposition and source localization methods. On a behavioural level, perception-action binding was increased in Tourette patients. Tic frequency correlated with performance in conditions where unbinding processes of previously established perception-action bindings were required with higher tic frequency being associated with stronger perception-action binding. This suggests that perception-action binding is intimately related to the occurrence of tics. Analysis of EEG data showed that behavioural changes cannot be explained based on simple perceptual or motor processes. Instead, cognitive processes linking perception to action in inferior parietal cortices are crucial. Our findings suggest that motor or sensory processes alone are less relevant for the understanding of Tourette syndrome than cognitive processes engaged in linking and restructuring of perception-action association. A broader cognitive framework encompassing perception and action appears well suited to opening new routes for the understanding of Tourette syndrome.
Acute Schistosomiasis With a Schistosoma mattheei × Schistosoma haematobium Hybrid Species in a Cluster of 34 Travelers Infected in South Africa
Authors: Cnops Lieselotte , Huyse Tine , Maniewski Ula , Soentjens Patrick , Bottieau Emmanuel , Van Esbroeck Marjan , Clerinx Joannes
Published: March 2020

Background

Diagnosis of schistosomiasis remains elusive soon after infection. We evaluated several diagnostic methods in a cluster of travelers with simultaneous freshwater exposure in South Africa.

Methods

Eosinophil count, schistosome antibody tests, stool and urine microscopy, and serum Dra1 PCR assays were performed at weeks 4–5 (early symptomatic phase), 7–8 (praziquantel treatment), and 13–14 (after treatment). Sequencing was done on serum samples from 3 patients to identify the species.

Results

Of the 34 travelers (16 adults and 18 children), 32 developed symptoms 2–6 weeks after exposure. A raised eosinophil count (>750/µL) was seen in 12 of 33 at weeks 4–5, and in 22 of 34 at weeks 7–8. Schistosoma antibodies were detected in 3 of 33 at weeks 4–5 and in 12 of 34 at weeks 7–8 and weeks 13–14. The Dra1 PCR result was positive in 24 of 33 travelers at weeks 4–5, in 31 of 34 at weeks 7–8, in 25 of 34 at weeks 13–14, and at least once in all. Ova were absent in all urine and stool samples obtained. Sequencing identified Schistosoma mattheei nuclear and Schistosoma haematobium mitochondrial DNA, indicative of a hybrid species.

Conclusions

The Dra1 PCR confirmed the diagnosis in all exposed travelers at a much earlier stage than conventional tests. The causative species is probably an S. mattheei × S. haematobium hybrid.
Outcome of cardiac tamponades in interventional electrophysiology
Authors: Fink Thomas , Sciacca Vanessa , Feickert Sebastian , Metzner Andreas , Lin Tina , Schlüter Michael , Tilz Roland Richard , Heeger Christian-Hendrik , Maurer Tilman , Reissmann Bruno , Rottner Laura , Mathew Shibu , Wohlmuth Peter , Ouyang Feifan , Kuck Karl-Heinz , Rillig Andreas
Published: March 2020

Aims

The aim of this study was to analyse tamponades following electrophysiological procedures regarding frequency and mortality in a high-volume centre and to identify independent predictors for severe tamponades.

Methods and results

We performed a retrospective study on 34 982 consecutive patients undergoing diagnostic electrophysiological studies or catheter ablation of cardiac arrhythmias. The combined endpoint was defined as severe tamponade. Criteria for severe tamponade included surgical repair, repeat pericardiocentesis, cardiopulmonary resuscitation, intrahospital death or death during follow-up, and thrombo-embolic events or complications due to therapeutic management. Multivariate analysis was performed to identify independent predictors for severe tamponade. A total of 226 tamponades were identified. Overall frequency of tamponades was 0.6%. Procedures requiring epicardial approach had the highest rate of tamponades (9.4%). Twenty-nine patients with tamponade underwent surgery (12.8% of all tamponades and 21.4% of tamponades during epicardial procedures). Overall tamponade-related mortality was 0.03% (9 deaths). Fifty-six patients (24.8%) experienced severe tamponade. Independent risk factors for severe tamponades were endocardial ablation of ventricular tachycardia, epicardial approach, balloon device ablation, high aspiration volume during pericardiocentesis and structural heart disease.

Conclusion

The frequency of tamponades is strongly dependent on the type of procedure performed. Overall tamponade-related mortality was low but significantly higher in patients undergoing epicardial procedures. Surgical backup should be considered for patients undergoing complex ventricular tachycardia ablation and left atrial ablation procedures.
Academic spill-ins or spill-outs? Examining knowledge spillovers of university patents
Authors: Moreira Solon , Soares Thiago J
Published: March 2020

In this article, we investigate whether academic technology-based knowledge crosses university boundaries or remains trapped inside the ivory tower. To do so, we rely on a matched sample approach to compare the spillovers generated by academic and firm patents using measures that take into account knowledge spilling-in and knowledge spilling-out of academia. Although it is true that knowledge exchanges among universities may inflate the overall spillovers of university patents vis-à-vis firm patents, our results indicate that university patents generate more spillovers than a comparable sample of matched corporate patents, even when knowledge flows among universities are not regarded as spillovers. This suggests that, in our sample, firm technologies more frequently rely on academic patents than on technologies from other corporations. In addition, we find that the gap between university and industry spillovers differs across industries, with industries where patents are important for appropriating returns from R&D (i.e. more economically valuable), such as drugs, presenting a smaller gap than in industries with complex technologies (where firms have strong incentives to patent aggressively), such as computers. Finally, we show that industry patents generate more spillovers locally and that academic knowledge spillovers are less geographically localized than those of corporate research.
Mathematically modelling inflammation as a promoter of tumour growth
Authors: Wilkie Kathleen P , Aktar Farjana
Published: March 2020

Inflammation is now known to play a significant role in tumour growth and progression. It is also difficult to adequately quantify systemic inflammation and the resulting localized effects in cancer. Here, we use experimental data to infer the possible contributions of inflammation in a mouse model of cancer. The model is validated by predicting tumour growth under anti-inflammatory treatments, and combination cancer therapies are explored. We then extend the model to consider simultaneous tumour implants at two distinct sites, which experimentally was shown to result in one large and one small tumour. We use this model to examine the role inflammation may play in the growth rate separation. Finally, we use this predictive two-tumour model to explore implications of inflammation on metastases, surgical removal of the primary and adjuvant anti-inflammatory treatments. This work suggests that improved tumour control can be obtained by targeting both the cancer and host, through anti-inflammatory treatments, including reduced metastatic burden post-surgical removal of primary tumours.
Evaluation of faba beans as an ingredient in dog diets: apparent total tract digestibility of extruded diets with graded levels of dehulled faba beans (Vicia faba L.) by dogs
Authors: Corsato Alvarenga Isabella , Holt Dalton , Aldrich Charles G
Published: March 2020

The growing pet food market is continuously in search for novel ingredients. Legumes such as faba beans (FB) are increasing in popularity and are known to benefit human health, but little is known about their use in pet foods. The objective of this study was to determine the effect of dehulled FB utilization by dogs. Experimental diets were extruded with 0%, 10%, 20%, and 30% FB inclusion (FB0, FB10, FB20, and FB30, respectively). Beagle dogs (n = 12) were fed the diets for 9-d adaptation with 5-d total fecal collection in a replicated 4 × 4 Latin square design. Apparent total tract digestibility (ATTD) was determined by external marker Cr2O3. At the culmination of each period, blood samples were collected from brachial venipuncture for complete blood count and blood chemistry. Palatability was determined with a 2-bowl test (n = 20). Means of blood parameters were separated by multivariate analysis of variance (MANOVA) with the aid of statistical software (SAS v9.4). Contrasts and least square means of fecal parameters and ATTD were computed. Significance level was considered to be α = 0.05. Dogs ate all food on offer and maintained body weight. There was no difference (P > 0.05) among treatments (FB10, FB20, and FB30) and the control (FB0) relative to food intake, fecal output (“as is” basis), and fecal score, but feces were softer when dogs were fed the treatments (P = 0.031) and there was a linear increase (P = 0.011) in defecation frequency (stools/day) when FB increased in the diets. Dry matter, organic matter, and crude protein digestibilities were slightly higher when dogs were fed the control diet (P < 0.05) compared with the FB diets. All blood and serum chemistry parameters were similar among treatments and within the reference ranges. Dogs preferred the control diet relative to the 10% and 30% FB diets, but the 20% FB preference was similar to the control. Dogs remained healthy, maintained body weight and no adverse health events were observed during the study. Dehulled FB are a suitable ingredient for dog foods, but concentrations should not exceed 20% to avoid reduction in palatability and stool quality.