bluuebunny/crossref_metadata_2025 huggingface dataset:
Fungal–bacterial interaction selects for quorum sensing mutants with increased production of natural antifungal compounds
Authors: Albarracín Orio Andrea G. , Petras Daniel , Tobares Romina A. , Aksenov Alexander A. , Wang Mingxun , Juncosa Florencia , Sayago Pamela , Moyano Alejandro J. , Dorrestein Pieter C. , Smania Andrea M.
Published: November 2020

Soil microorganisms coexist and interact showing antagonistic or mutualistic behaviors. Here, we show that an environmental strain of Bacillus subtilis undergoes heritable phenotypic variation upon interaction with the soil fungal pathogen Setophoma terrestris (ST). Metabolomics analysis revealed differential profiles in B. subtilis before (pre-ST) and after (post-ST) interacting with the fungus, which paradoxically involved the absence of lipopeptides surfactin and plipastatin and yet acquisition of antifungal activity in post-ST variants. The profile of volatile compounds showed that 2-heptanone and 2-octanone were the most discriminating metabolites present at higher concentrations in post-ST during the interaction process. Both ketones showed strong antifungal activity, which was lost with the addition of exogenous surfactin. Whole-genome analyses indicate that mutations in ComQPXA quorum-sensing system, constituted the genetic bases of post-ST conversion, which rewired B. subtilis metabolism towards the depletion of surfactins and the production of antifungal compounds during its antagonistic interaction with S. terrestris.
Adaptation by copy number variation increases insecticide resistance in the fall armyworm
Authors: Gimenez Sylvie , Abdelgaffar Heba , Goff Gaelle Le , Hilliou Frédérique , Blanco Carlos A. , Hänniger Sabine , Bretaudeau Anthony , Legeai Fabrice , Nègre Nicolas , Jurat-Fuentes Juan Luis , d’Alençon Emmanuelle , Nam Kiwoong
Published: November 2020

Understanding the genetic basis of insecticide resistance is a key topic in agricultural ecology. The adaptive evolution of multi-copy detoxification genes has been interpreted as a cause of insecticide resistance, yet the same pattern can also be generated by the adaptation to host-plant defense toxins. In this study, we tested in the fall armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae), if adaptation by copy number variation caused insecticide resistance in two geographically distinct populations with different levels of resistance and the two host-plant strains. We observed a significant allelic differentiation of genomic copy number variations between the two geographic populations, but not between host-plant strains. A locus with positively selected copy number variation included a CYP gene cluster. Toxicological tests supported a central role for CYP enzymes in deltamethrin resistance. Our results indicate that copy number variation of detoxification genes might be responsible for insecticide resistance in fall armyworm and that evolutionary forces causing insecticide resistance could be independent of host-plant adaptation.
Using anion photoelectron spectroscopy of cluster models to gain insights into mechanisms of catalyst-mediated H2 production from water
Authors: McMahon Abbey J. , Jarrold Caroline Chick
Published: November 2020

Anion PE spectroscopy and DFT calculations reveal molecular and electronic structural features of cluster models for catalysis.
Slow magnetization relaxation in a tetrahedrally coordinated mononuclear Co(ii) complex exclusively ligated with phenanthroline ligands
Authors: Wu Chen-Ming , Tsai Jae-En , Lee Gene-Hsiang , Yang En-Che
Published: November 2020

Clear frequency-dependent out-of-phase signals as well as a series of careful experiments indicate that the purely nitrogen coordinated mononuclear Co(ii) complex reported here is a SIM.
Femtomolar detection of thiram via SERS using silver nanocubes as an efficient substrate
Authors: Bhavya M. B. , Prabhu B. Ramya , Shenoy Bhamy Maithry , Bhol Prangya , Swain Swarnalata , Saxena Manav , John Neena S. , Hegde Gopalkrishna , Samal Akshaya K.
Published: November 2020

Silver nanocubes are demonstrated to be an efficient substrate for the detection of the fungicide thiram, at ultra-low concentrations.
Simple method to quantify extraneous water and organic matter degradation in sewer networks
Authors: Yang Fengle , Zhang Xianzhi , Li Jinhua , Jin Fangming , Zhou Baoxue
Published: November 2020

Extraneous water and COD degradation along sewer networks were quantified by using the balance model of water flow and pollutant loads.
AGLPM and QMDDQ peptides exert a synergistic action on memory improvement against scopolamine-induced amnesiac mice
Authors: Wu Dan , Xu Xiaomeng , Sun Na , Li Dongmei , Zhu Beiwei , Lin Songyi
Published: November 2020

This study aimed to explore the synergistic action of pentapeptides Gln-Met-Asp-Asp-Gln (QMDDQ) and Ala-Gly-Leu-Pro-Met (AGLPM) on memory improvement against scopolamine-induced impairment in mice compared to those of either of the peptides alone.
Cu(i) diimine complexes as immobilised antibacterial photosensitisers operating in water under visible light
Authors: Appleby Martin V. , Walker Peter G. , Pritchard Dylan , van Meurs Sandra , Booth Carly M. , Robertson Craig , Ward Michael D. , Kelly David J. , Weinstein Julia A.
Published: November 2020

A simple complex of copper immobilised on silica exemplifies how lighter transition metal complexes can efficiently kill both Gram-positive and Gram-negative bacteria in water – in some cases in only 15 min – under visible light.
Identification of 3-hydroxy-1,2-dimethylpyridine-4(1H)-thione as a metal-binding motif for the inhibition of botulinum neurotoxin A
Authors: Lin Lucy , Turner Lewis D. , Šilhár Peter , Pellett Sabine , Johnson Eric A. , Janda Kim D.
Published: November 2020

The 3,4-HOPTO pharmacophore was identified as an inhibitor of botulinum neurotoxin A light chain. Structure-activity relationships were explored, resulting in a compound that protects SNAP-25 cleavage in motor neurons.
Interfacial engineering with carbon–graphite–CuδNi1−δO for ambient-air stable composite-based hole-conductor-free perovskite solar cells
Authors: Wang Yousheng , Yang Yuzhao , Wu Shaohang , Zhang Cuiling , Wang Zhen , Hu Jinlong , Liu Chong , Guo Fei , Mai Yaohua
Published: November 2020

Fully-ambient-air processed HCF-PSCs based on carbon–graphite–CuδNi1−δO composites show not only efficient performance but also remarkably improved photo-, thermal-stability and long-term air stability.
Distribution in the brain and possible neuroprotective effects of intranasally delivered multi-walled carbon nanotubes
Authors: Soligo Marzia , Felsani Fausto Maria , Da Ros Tatiana , Bosi Susanna , Pellizzoni Elena , Bruni Stefano , Isopi Jacopo , Marcaccio Massimo , Manni Luigi , Fiorito Silvana
Published: November 2020

Carbon nanotubes (CNTs) are currently under active investigation for their use in several biomedical applications, especially in neurological diseases and nervous system injury due to their electrochemical properties.
Facile synthesis of graphene oxide from graphite rods of recycled batteries by solution plasma exfoliation for removing Pb from water
Authors: Van Hao Nguyen , Van Dang Nguyen , Tung Do Hoang , Tan Pham The , Van Tu Nguyen , Van Trinh Pham
Published: November 2020

Facile synthesis of graphene oxide from graphite rods of recycled batteries by solution plasma exfoliation for removing Pb from water.
Ionic conductivity enhancement in solid polymer electrolytes by electrochemicalin situformation of an interpenetrating network
Authors: Leš Kristian , Jordan Carmen-Simona
Published: November 2020

Conductive polymers were encapsulated and subsequently overoxidized in an acrylate polymer matrix as potential separator materialsviathe combination of UV-induced and electrochemical polymerization.
Design of a new multi-functional catalytic system Ni/SO3H@zeolite-Y for three-component synthesis ofN-benzo-imidazo- or -thiazole-1,3-thiazolidinones
Authors: Kalhor Mehdi , Banibairami Soodabeh
Published: November 2020

In this investigation, a nanoporous zeolite-NaY supported sulfonic acid was synthesized and Ni(ii) ions were successfully stabilized on its (Ni/SO3H@zeolite-Y) and was used as a multi-functional catalyst for green synthesis of 1,3-thiazolidinones.
Structural insight into [Fe–S2–Mo] motif in electrochemical reduction of N2 over Fe1-supported molecular MoS2
Authors: Zheng Jianwei , Wu Simson , Lu Lilin , Huang Chen , Ho Ping-Luen , Kirkland Angus , Sudmeier Tim , Arrigo Rosa , Gianolio Diego , Edman Tsang Shik Chi
Published: November 2020

A nitrogenase-inspired inorganic-based chalcogenide system containing [Fe–S2–Mo] motif is developed for the efficient electrochemical conversion of N2 to NH3.
An ultrathin TiO2 interfacial layer enhancing the performance of an FeVO4 photoanode for water splitting
Authors: Wu Jiancong , Guo Wenya , Ding Zhengxin , Zhang Jinshui , Hou Yidong
Published: November 2020

The introduction of an ultrathin TiO2 interfacial layer efficiently enhanced the performance of an FeVO4 photoanode for water splitting.
Ethical Considerations on Pediatric Genetic Testing Results in Electronic Health Records
Authors: Kanungo Shibani , Barr Jayne , Crutchfield Parker , Fealko Casey , Soares Neelkamal
Published: November 2020

Background Advances in technology and access to expanded genetic testing have resulted in more children and adolescents receiving genetic testing for diagnostic and prognostic purposes. With increased adoption of the electronic health record (EHR), genetic testing is increasingly resulted in the EHR. However, this leads to challenges in both storage and disclosure of genetic results, particularly when parental results are combined with child genetic results.

Privacy and Ethical Considerations Accidental disclosure and erroneous documentation of genetic results can occur due to the nature of their presentation in the EHR and documentation processes by clinicians. Genetic information is both sensitive and identifying, and requires a considered approach to both timing and extent of disclosure to families and access to clinicians.

Methods This article uses an interdisciplinary approach to explore ethical issues surrounding privacy, confidentiality of genetic data, and access to genetic results by health care providers and family members, and provides suggestions in a stakeholder format for best practices on this topic for clinicians and informaticians. Suggestions are made for clinicians on documenting and accessing genetic information in the EHR, and on collaborating with genetics specialists and disclosure of genetic results to families. Additional considerations for families including ethics around results of adolescents and special scenarios for blended families and foster minors are also provided. Finally, administrators and informaticians are provided best practices on both institutional processes and EHR architecture, including security and access control, with emphasis on the minimum necessary paradigm and parent/patient engagement and control of the use and disclosure of data.

Conclusion The authors hope that these best practices energize specialty societies to craft practice guidelines on genetic information management in the EHR with interdisciplinary input that addresses all stakeholder needs.
Game theoretic analysis of persons, the pharmaceutical industry, and donors in disease contraction and recovery
Authors: Hausken Kjell , Ncube Mthuli
Published: November 2020

Disease contraction and recovery depend on complex interaction between persons potentially contracting and recovering from the disease, the pharmaceutical industry potentially developing drugs, and donors potentially subsidizing drug development and drug purchases. Instead of analyzing each of these three kinds of players separately, assuming the behavior of the other two kinds of players to be given, this article analyzes the three kinds of players holistically and how they mutually interact and react to each other. A five-period game between N persons and a pharmaceutical company is developed. Each person chooses safe or risky behavior, and whether or not to buy a drug. The objectives are to determine which strategies the N persons and the pharmaceutical company choose depending on the model parameters. The pharmaceutical company develops the drug if sufficiently many persons contract the disease and buy the drug. A donor chooses parametrically whether to subsidize drug development and drug purchases. Nature chooses probabilistically disease contraction, and recovery versus death with and without applying the drug. The methodological procedure is to solve the game with backward induction specifying the conditions for each of five outcomes ranging from safe behavior to risky behavior and buying the drug. The results in the form of five outcomes for a person are safe behavior, risky behavior and no disease contraction, disease contraction without drug availability, disease contraction with drug availability but without buying the drug, and disease contraction and buying the drug. These five outcomes are spread across two outcomes for the pharmaceutical company which are not to develop versus to develop the drug. The utility for the donor is specified for these two outcomes. A procedure for estimating the parameters is presented based on HIV/AIDS data. The results are discussed in terms of how various parameter combinations cause the five outcomes. An example illustrates the players’ strategic choices.
Crystal growth and flat-band effects on thermoelectric properties of Fe2TiAl-based full-Heusler thin films
Authors: Kurosaki Y. , Yabuuchi S. , Nishide A. , Fukatani N. , Hayakawa J.
Published: November 2020

In this study, various Fe-based thermoelectric full-Heusler thin films were fabricated on MgO substrates by a post-annealing process. It is clarified that crystal growth through the post-annealing process is prevented by both an initial crystallization and a lattice mismatch between the thin films and the substrate. One of the thermoelectric materials, namely, Fe2TiAl, was almost epitaxially grown on the substrate from an initial amorphous state owing to a small mismatch of less than 3%. The thermoelectric properties of Fe2TiAl-based thin films were modulated by changing the material composition. We found that they strongly depend on not only the valence electron concentration and the Fe amount as was observed in typical thermoelectric full-Heusler, Fe2VAl, but also the electronic band structures. The flat band in the conduction band strongly affects not only the n-type thermoelectric performance but also the p-type ones; the large density of states in the conduction band prevents the p-type Seebeck coefficient from increasing. The Seebeck coefficient of a V-added Fe2TiAl thin film with a composition of Fe2.01Ti0.56V0.67Al0.76 was increased to 99 µV/K by controlling the flat band in the conduction band away from the valence band to reduce the effects of the flat band, resulting in a dimensionless figure of merit of 0.12 at room temperature.
Dissipative instability of converging cylindrical shock wave
Authors: Chefranov Sergey G.
Published: November 2020

The condition of linear instability for a converging cylindrical strong shock wave (SW) in an arbitrary viscous medium is obtained in the limit of a large stationary SW radius when it is possible to consider the same Rankine–Hugoniot jump relations as for the plane SW. This condition of instability is substantially different from the condition of instability for the plane SW because a cylindrical SW does not have a chiral symmetry in the direction of the SW velocity (from left to right or vice versa) as in the case of a plane SW. The exponential growth rate of perturbations for the converging cylindrical SW is positive only for nonzero viscosity in the limit of high, but finite, Reynolds numbers as well as for the instability of a plane SW.
Threshold photodetachment spectroscopy of the astrochemical anion CN−
Authors: Simpson Malcolm , Nötzold Markus , Schmidt-May Alice , Michaelsen Tim , Bastian Björn , Meyer Jennifer , Wild Robert , Gianturco Franco A. , Milovanović Milan , Kokoouline Viatcheslav , Wester Roland
Published: November 2020

Threshold photodetachment spectroscopy has been performed on the molecular anion CN− at both 16(1) K and 295(2) K in a 22-pole ion trap and at 295(2) K from a pulsed ion beam. The spectra show a typical energy dependence of the detachment cross section yielding a determination of the electron affinity of CN to greater precision than has previously been known at 31 163(16) cm−1 [3.864(2) eV]. Allowed s-wave detachment is observed for CN−, but the dependence of the photodetachment cross section near the threshold is perturbed by the long-range interaction between the permanent dipole moment of CN and the outgoing electron. Furthermore, we observe a temperature dependence of the cross section near the threshold, which we attribute to a reduction of the effective permanent dipole due to higher rotational excitation at higher temperatures.
Financial contributions made by patients towards dispensed medicines prescribed by Australian dentists from 2006 to 2018: a cost-analysis study
Authors: Park Joon Soo , Kruger Estie , Tennant Marc
Published: November 2020

Objective This cost-analysis study explored Pharmaceutical Benefits Scheme (PBS) data to determine the financial patient contribution (PC) towards dispensed medications prescribed by dentists and temporal trends in cost contributions. Methods For this study we used the PBS online dataset and only included concessional data in the analysis. Data on dental medications dispensed under the PBS from 2006 to 2018 were accessed. For all medicines aggregated to different pharmacological categories (antibiotics, analgesics and opiates, anti-inflammatories, antifungals, benzodiazepines, anticonvulsants and anti-emetics, and emergency medications), a temporal trend was generated using annual PC data. Cumulative patient and mean annual PC data were also generated in a similar manner. Results Cumulative PC over the study period for dental PBS prescriptions was A$28 783 361 (A$5.55 per dispensing). The mean annual PC for dental PBS was A$2 214 105 (for the entire concessional population from 2006 to 2018), with a statistically significant and strong correlation between year and PC (Dental PBS, A$59 756 per year; r = 0.98: P < 0.0001). Antibiotics represented the highest proportion of PC (87.8%), whereas the lowest proportion of PC was for emergency medications (e.g. adrenaline, atropine, glucagon, naloxone), which amounted to 0.003%. Conclusions This study highlights the increasing contributions made by patients towards antibiotic prescriptions. What is known about the topic? Australian dentists can independently prescribe subsidised medications as per a set scope for general and specialist dentists, regulated under the PBS with requisite adherence to specific legal requirements. What does this paper add? This is the first study highlighting the increased level of patient financial contributions towards dental medicines, according to different pharmacological categories, dispensed by pharmacists in Australia. What are the implications for practitioners? This study creates a base for future research assessing the appropriateness of the PBS subsidy and the PBS Safety Net threshold, possibly reassessing the out-of-pocket pricing on brand substitution and appropriately reassessing the current dental PBS schedule.
Decoding transcreation in corporate website localization into Arabic
Authors: Kassawat Madiha
Published: November 2020

As adaptation is often associated with localization, and with the promotion of transcreation as an extra service
in the industry, there is a need to analyze how and to what extent transcreation is used in localization as a type of
target-culture-focused translation. This paper looks into adaptation and analyzes transcreation as a translation strategy. It
investigates online promotional texts localized into Arabic (for Saudi Arabia) as an under-researched language in website
localization. The analysis follows a functionalist approach and examines 15 international corporate websites. The results
illustrate components of transcreated texts and shed light on the use of different procedures to achieve the creative persuasive
purpose.
French-language COVID-19 terminology
Authors: Bowker Lynne
Published: November 2020

The COVID-19 pandemic situation developed very quickly, driving an urgent and global need to communicate public health information that left relatively little time for traditional and formal language planning activities. This article investigates and compares French-language COVID-19-related terms appearing in linguistic resources developed in Canada and Europe to determine whether this terminology appears to be international or localized. Findings reveal that regional variation exists and that one contributing factor is that de-terminologization is being accelerated by the popular media. Another key factor leading to linguistic differences is the language situation (i.e., majority vs minority situation). Overall, while there is considerable overlap in the terminology used in the two resources, there are enough differences to warrant underlining the importance of localizing terminological content in a situation such as a pandemic in order to ensure that communication of critical information is as effective as possible.
Gradability across grammatical domains
Authors: Bowler Margit , Gluckman John
Published: November 2020

This paper argues that ordered abstract scales are applicable to analyses of a range of grammatical domains. We argue this based on data from a number of unrelated languages, primarily Logoori (Bantu, JE 41; Kenya). The Logoori verbkudokacan be translated into English as ‘to arrive’/‘to reach,’ ‘to be enough,’ and ‘must,’ depending on its linguistic context. We propose that these meanings arise from a single semantic denotation that is sensitive to a shared gradable component in the semantics of linguistic expressions referring to spatial paths, gradable predicates, measures of plural count nouns/mass nouns, and modals. The central theoretical issue addressed in this paper is the application of ordered, abstract scales in a model of grammar. This data and proposal is an important contribution to the literature arguing for a gradable model of modality (Lassiter 2014,2017b, among others).
Solidification dynamics in metal additive manufacturing: analysis of model assumptions
*
Authors: Stump B , Plotkowski A , Coleman J
Published: November 2020

Solidification characteristics in the meltpool drive the process-microstructure relationship which helps dictate the material properties of as-built parts in additive manufacturing; therefore, being able to accurately and quickly simulate the size, shape, and solidification characteristics in the melt pool is of great interest to the field. This study investigates various important physical phenomena (dynamic material properties, fluid-flow, radiation and vaporization) which can either be included or neglected in a continuum finite volume model (FVM) and their effect on the solidification conditions. Additionally, since the simplest form of such a model (conduction only) has an analytic solution which is much faster, its viability is also considered. Since the inclusion of some of these physical phenomena will inherently change the net energy input as well as the amount of energy needed to achieve melting of a control volume, each set of included phenomena had an effective absorption efficiency which was calibrated to closely match the dimensions of the melt pool to that of the ground truth data. The ground truth data for this study was defined to be the output of the FVM which included all the physical phenomena (OF). This study then goes on to compare the effects on solidification conditions each of these calibrated models has. It was found that most of the change in solidification conditions comes from the inclusion of latent heat. A posterior correlation factor (PCF) is then introduced to enable an analytic model to predict similar solidification conditions to OF model.
Phase separated bi-metallic PtNi nanoparticles formed by pulsed laser dewetting
Authors: Ahn Kangwoo , Lee Su Yong , Cho In Hwa , Kim Yoonhee , Kang Hyon Chol , Noh Do Young
Published: November 2020

We present morphological and compositional analysis of phase-separated Pt–Ni alloy nanoparticles (NPs) formed by ns pulsed laser dewetting. The PtNi NPs obtained by the pulsed laser dewetting consist of phase-separated multiple domains including Pt3Ni, PtNi and PtNi3 phases with various crystal orientations as revealed by transmission electron microscopy, which is in contrast to thermal dewetting resulting NPs of a uniform composition. A three-dimensional (3D) electron density map of a dewetted PtNi NP obtained using the coherent x-ray diffraction microscopy elucidates the 3D morphology of Pt- and Ni-rich regions together with a nano-cavity formed during the pulsed laser irradiation.
Synergy between alkali activation and a salt template in superactive carbon production from lignin
Authors: Ponomarev Nikolai P , Kallioinen Mari
Published: November 2020

Due to growing demand, the performance of traditional active carbon is insufficient. An innovative solution is superactive carbon with an ultra-high surface area as high as 3000 m2 g−1. However, this material is very costly due to the considerable amount of alkali used in its manufacturing. To obtain superactive carbon from lignin, KOH and KCl were used simultaneously. The method was thoroughly studied to describe the mechanism of pore origin and control the pore size. Because of synergy between KOH and KCl, superactive carbon with an ultra-high surface area (2938 ± 42 m2 g−1) was obtained at essentially diminished KOH consumption (1 g g−1) in contrast to previously reported methods. The process was optimised using the response surface method. The pore size can be tuned by varying the amount of KOH and temperature. Observed synergy enabled reduced alkali consumption, overcoming the barrier to widespread implementation of superactive carbon.
Recursion and Hamiltonian operators for integrable nonabelian difference equations
Authors: Casati Matteo , Wang Jing Ping
Published: November 2020

In this paper, we carry out the algebraic study of integrable differential-difference equations whose field variables take values in an associative (but not commutative) algebra. We adapt the Hamiltonian formalism to nonabelian difference Laurent polynomials and describe how to obtain a recursion operator from the Lax representation of an integrable nonabelian differential-difference system. As an application, we study a family of integrable equations: the nonabelian Narita–Itoh–Bogoyavlensky lattice, for which we construct their recursion operators and Hamiltonian operators and prove the locality of infinitely many commuting symmetries generated from their highly nonlocal recursion operators. Finally, we discuss the nonabelian version of several integrable difference systems, including the relativistic Toda chain and Ablowitz–Ladik lattice.
DeepMC: a deep learning method for efficient Monte Carlo beamlet dose calculation by predictive denoising in magnetic resonance-guided radiotherapy
Authors: Neph Ryan , Lyu Qihui , Huang Yangsibo , Yang You Ming , Sheng Ke
Published: November 2020

Emerging magnetic resonance (MR) guided radiotherapy affords significantly improved anatomy visualization and, subsequently, more effective personalized treatment. The new therapy paradigm imposes significant demands on radiation dose calculation quality and speed, creating an unmet need for the acceleration of Monte Carlo (MC) dose calculation. Existing deep learning approaches to denoise the final plan MC dose fail to achieve the accuracy and speed requirements of large-scale beamlet dose calculation in the presence of a strong magnetic field for online adaptive radiotherapy planning. Our deep learning dose calculation method, DeepMC, addresses these needs by predicting low-noise dose from extremely noisy (but fast) MC-simulated dose and anatomical inputs, thus enabling significant acceleration. DeepMC simultaneously reduces MC sampling noise and predicts corrupted dose buildup at tissue-air material interfaces resulting from MR-field induced electron return effects. Here we demonstrate our model’s ability to accelerate dose calculation for daily treatment planning by a factor of 38 over traditional low-noise MC simulation with clinically meaningful accuracy in deliverable dose and treatment delivery parameters. As a post-processing approach, DeepMC provides compounded acceleration of large-scale dose calculation when used alongside established MC acceleration techniques in variance reduction and graphics processing unit-based MC simulation.
Helium radiography with a digital tracking calorimeter—a Monte Carlo study for secondary track rejection
Authors: Pettersen Helge Egil Seime , Volz Lennart , Sølie Jarle Rambo , Alme Johan , Barnaföldi Gergely Gábor , Barthel Rene , van den Brink Anthony , Borshchov Vyacheslav , Chaar Mamdouh , Eikeland Viljar , Genov Georgi , Grøttvik Ola , Helstrup Håvard , Keidel Ralf , Kobdaj Chinorat , van der Kolk Naomi , Mehendale Shruti , Meric Ilker , Harald Odland Odd , Papp Gábor , Peitzmann Thomas , Piersimoni Pierluigi , Protsenko Maksym , Ur Rehman Attiq , Richter Matthias , Tefre Samnøy Andreas , Seco Joao , Shafiee Hesam , Songmoolnak Arnon , Tambave Ganesh , Tymchuk Ihor , Ullaland Kjetil , Varga-Kofarago Monika , Wagner Boris , Xiao RenZheng , Yang Shiming , Yokoyama Hiroki , Röhrich Dieter
Published: November 2020

Radiation therapy using protons and heavier ions is a fast-growing therapeutic option for cancer patients. A clinical system for particle imaging in particle therapy would enable online patient position verification, estimation of the dose deposition through range monitoring and a reduction of uncertainties in the calculation of the relative stopping power of the patient.

Several prototype imaging modalities offer radiography and computed tomography using protons and heavy ions. A Digital Tracking Calorimeter (DTC), currently under development, has been proposed as one such detector. In the DTC 43 longitudinal layers of laterally stacked ALPIDE CMOS monolithic active pixel sensor chips are able to reconstruct a large number of simultaneously recorded proton tracks.

In this study, we explored the capability of the DTC for helium imaging which offers favorable spatial resolution over proton imaging. Helium ions exhibit a larger cross section for inelastic nuclear interactions, increasing the number of produced secondaries in the imaged object and in the detector itself. To that end, a filtering process able to remove a large fraction of the secondaries was identified, and the track reconstruction process was adapted for helium ions.

By filtering on the energy loss along the tracks, on the incoming angle and on the particle ranges, 97.5% of the secondaries were removed. After passing through 16 cm water, 50.0% of the primary helium ions survived; after the proposed filtering 42.4% of the primaries remained; finally after subsequent image reconstruction 31% of the primaries remained. Helium track reconstruction leads to more track matching errors compared to protons due to the increased available focus strength of the helium beam. In a head phantom radiograph, the Water Equivalent Path Length error envelope was 1.0 mm for helium and 1.1 mm for protons. This accuracy is expected to be sufficient for helium imaging for pre-treatment verification purposes.
Data-driven dose calculation algorithm based on deep U-Net
Authors: Fan Jiawei , Xing Lei , Dong Peng , Wang Jiazhou , Hu Weigang , Yang Yong
Published: November 2020

Accurate and efficient dose calculation is an important prerequisite to ensure the success of radiation therapy. However, all the dose calculation algorithms commonly used in current clinical practice have to compromise between calculation accuracy and efficiency, which may result in unsatisfactory dose accuracy or highly intensive computation time in many clinical situations. The purpose of this work is to develop a novel dose calculation algorithm based on the deep learning method for radiation therapy. In this study we performed a feasibility investigation on implementing a fast and accurate dose calculation based on a deep learning technique. A two-dimensional (2D) fluence map was first converted into a three-dimensional (3D) volume using ray traversal algorithm. 3D U-Net like deep residual network was then established to learn a mapping between this converted 3D volume, CT and 3D dose distribution. Therefore an indirect relationship was built between a fluence map and its corresponding 3D dose distribution without using significantly complex neural networks. Two hundred patients, including nasopharyngeal, lung, rectum and breast cancer cases, were collected and applied to train the proposed network. Additional 47 patients were randomly selected to evaluate the accuracy of the proposed method through comparing dose distributions, dose volume histograms and clinical indices with the results from a treatment planning system (TPS), which was used as the ground truth in this study. The proposed deep learning based dose calculation algorithm achieved good predictive performance. For 47 tested patients, the average per-voxel bias of the deep learning calculated value and standard deviation (normalized to the prescription), relative to the TPS calculation, is 0.17%±2.28%. The average deep learning calculated values and standard deviations for relevant clinical indices were compared with the TPS calculated results and the t-test p-values demonstrated the consistency between them. In this study we developed a new deep learning based dose calculation method. This approach was evaluated by the clinical cases with different sites. Our results demonstrated its feasibility and reliability and indicated its great potential to improve the efficiency and accuracy of radiation dose calculation for different treatment modalities.
Piezoelectric energy enhancement strategy for active fuzzy harvester with time-varying and intermittent switching
Authors: Hara Yushin , Zhou Meng , Li An , Otsuka Keisuke , Makihara Kanjuro
Published: November 2020

This study aims to increase the amount of electrical energy harvested from a piezoelectric vibration energy harvester under unloaded and high-load resistance conditions. Although increased piezoelectric charge due to the synchronized switch harvesting on inductor (SSHI) strategy damps mechanical vibrations, the mechanical vibration amplitude of a mechanical element in a harvester is assumed to be constant for most discussions regarding the active harvester with SSHI strategy. However, this assumption is not valid under excessive switching actions, in which case the performance of the harvester deteriorates. This problem is known as the vibration suppression effect. To address this problem, in this study, two switching strategies for the charge inversion circuit—namely, switching considering vibration suppression-threshold (SCVS-t) and adaptive SCVS-t (ASCVS-t)—are proposed through intermittent switching actions. During the harvesting process, intermittent switching using these strategies is performed based on the output voltage threshold, thus maintaining high mechanical vibration amplitude and excellent harvesting performance by avoiding excess switching. The ASCVS-t adopts a tuning algorithm for the time-varying threshold and can achieve appropriate intermittent switching and effective harvesting under various vibration conditions without pre-tuning. Experimental comparisons with conventional strategies confirm that the proposed strategies achieve 2.9 times and 2.0 times greater harvested energy storages than a standard harvester and conventional switching strategy, respectively.
Receptor-mediated endocytosis of nanoparticle based on the co-rotational grid method
Authors: Xu Wu , Jia Kangyu , Liu Xiaohu
Published: November 2020

Endocytosis is a cellular process in which the nanoparticle can be internalized to form a vesicle. Receptor-mediated transport is a mainly endocytic pathway, and many theoretical models have been proposed to study the physiochemical mechanism underlying this specific endocytic pathway. Traditional methods mainly focus on the interactions between the nanoparticles and the plasma membrane. The role that actin force plays during endocytosis of nanoparticle is neglected. However, recent extraordinary studies show that the actin force is the main driving force in endocytosis. Based on previous instructive models and configurations of the actin network observed in literature, there mainly exist oblique push and pull forces generated by the growth of actin network at the endocytic site and the lateral contraction force produced by proteins such as myosin at the concave neck of membrane. Considering these two different actin force-generation mechanisms, a new actin force model is proposed in this paper. Then, a numerical analysis is performed based on the co-rotational grid method. Besides, and the influence of osmotic pressure, the plasma membrane stiffness, actin force containing growth process and asymmetry of the actin network have been investigated. Meanwhile, the relative importance of the two actin force-generation mechanism is obtained, which is consistent with the theoretical and experimental results in literature. Our model can obtain the critical nanoparticle radius that can be absorbed most efficiently by considering the force that actin filaments could provide. And our results show that there exist a critical size for nanoparticle which could only be absorbed by tumor cell. In addition, the effects of growth process and asymmetry of the actin network are discussed. This method has the potential to reveal the underlying mechanisms of the complex dynamic behaviors of the endocytosis process.
Influence of formation activation induced by fracturing fluid on casing deformation during hydraulic fracturing operation in shale gas wells
Authors: Zeng Y J , Du J L , Zhou S M , Qian Q Tao , Liu K
Published: November 2020

Sichuan Basin in China is rich in shale gas resources and has great exploration and development capacity. It is the main area of shale gas exploration and production in China. The proved shale gas reserves discovered by Sinopec in Weirong area exceed 100 billion m3, and they play an important role in the development of shale gas in China. In Sichuan Basin, the use of traditional shale gas production methods such as multi-stage hydraulic fracturing is hampered by serious casing deformation. By December 2019, Sinopec performed hydraulic fracturing operations in 20 wells in this area, where casing deformation was encountered in 10 wells, resulting in an increase of up to 5.69% in the proportion of invalid fracture sections. In order to explain the mechanism of casing deformation during hydraulic fracturing, the geological structures of a shale gas production site in Sichuan Basin with frequent casing deformation were examined, and the geological reasons for this deformation were revealed. In addition, a geological model was established to calculate the influence of formation activation induced by fracturing fluid on the casing load, and formation activation during hydraulic fracturing was studied. The results reported in this paper are of great significance for optimizing hydraulic fracturing parameters and reducing the influence of formation activities on the casing of horizontal wells.
DEM analysis on the triaxial behaviour of mudstone considering water disintegration
Authors: Cao Zhensheng , Jia Tong , Zhang Shaoqiang , Ouyang Xun , Jiang Chuanbin , Huang Xin
Published: November 2020

Mudstone is a typical type of soft rocks. It is stable and has high strength in its natural state. However, in presence of water the constituent minerals dissolve and the inter-grain bonds are weakened, which thereby greatly reduces the strength of mudstone. As one of the most prevailing geological formations in the southwestern China, understanding the mechanical behaviour of mudstone at different degrees of disintegration is of great importance to practical engineering. This paper presents a micro-mechanical analysis on the mechanical behaviour of mudstone at different degrees of disintegration using the discrete element method (DEM). The laboratory triaxial tests carried out on mudstone samples that have been merged in water for different time periods are simulated. The dissolution of minerals and weakening of bonds between grains are considered by reducing the selected input parameters of parallel bonds at random locations. Different degrees of disintegration are obtained by multiplying the selected input parameters of parallel bonds with different reducing factors. The stress-strain curves obtained using the proposed approach are in good agreements with the experimental data. The progressive failure mechanism of mudstone at different degrees of disintegration is investigated considering the characteristics of particle motion, contact variation and bond breakage. Micro-scale analysis shows that with the increasing of confining pressure, the fraction of shear breakage of parallel bonds increases but the declining rate of coordination number post peak decreases. These underlie the fundamental mechanism of the change of failure mode of mudstone from brittleness to ductileness. Regardless of its spatial locations, the majority of broken bonds for the disintegrated specimens are those bonds with reduced input parameters. And the fraction of altered bonds within the broken bonds increases with the increasing degree of disintegration. The current research provides insightful understanding of the fundamental behaviour of mudstone in the presence of water.
Regulation functions in the Beilun estuary by tidal numerical simulation
Authors: Guo Y Q , Ma J R , Huang L Y , Zou G L
Published: November 2020

It is a relatively short distance from mountains to the sea for the Beilun river. Its runoff seasonally varies with strong flooding and less sand. The mangroves are unique and spread wildly in the estuary to maintain a stable riverbed by scouring the waves and currents. However, the regulation structures built along the estuary by both China and Vietnam were not well-designed according to the laws of flow and sediment movement. A numerical model has been developed to simulate the functions of the regulations in this paper. Today, the shape of the estuary is mostly formed by the regulation structures. The discharge ratio and velocity changes are displayed to reveal the effects of the regulations. Coriolis force is intended to drive the flooding and ebbing flow in different ways, so the south passage usually becomes deeper and larger while the river island usually connects to the north shore in the northern portion of the earth. However, this phenomenon has not properly worked in this region, likely due to other manmade activities and the mangroves defending the shallows from scouring while the regulations are directing the flow currents.
A Simulation Study of the Emergency Double-Row Micropile Reinforcement of the Xituo Landslide
Authors: Liu ZhongShuai , Zou Wukun , Deng Sangen , Fu Yu , Tang Shengchuan , Gou Dongyuan , Xu Feng
Published: November 2020

This paper studies the suitability of a double-row anti-slide micropile solution for the emergency reinforcement project of the Xituo landslide. The FLAC3D program was used to simulate the stability of the landslide before and after micropile installation. Several key parameters were monitored in the simulation such as the landslide displacement, the shear strain rate at the slip surface, as well as the bending moments and the shear forces exerted on the piles. Both the displacement graph and the shear strain rate cloud map of the landslide before reinforcement indicate that the Xituo landslide is in an unstable state and tends toward accelerated collapse. After the double-row anti-slide micropiles were installed, the displacement of the slope toe gradually stabilized, and the displacement on the river side of the highway was significantly reduced. Moreover, the shear strain rate cloud diagram at the location of the micropiles developed upward, and the shear strain rate was small. These changes indicate that the double-row anti-slide micropiles could effectively restrain further deformation and damage because of the Xituo landslide. Furthermore, the simulated maximum shear forces exerted on the piles, 115.5 and 75.8 kN, are much lower than the maximum micropile design value of 260 kN. The simulated maximum pile body bending moments, 3173.8 and 1170.0 kNm, also fall below the recommended maximum value of 4500 kNm. Therefore, double-row anti-slide micropiles are an effective and practical solution for stabilizing the Xituo landslide.
Seismic stability of an underground cavern in jointed rock mass based on the discrete fracture network
Authors: Cun Chu , Peishuai Chen , Qing Yuan , Hong Jiang , Deding Feng
Published: November 2020

In the construction of underground structures in high seismic intensity areas, it is inevitable that a fault fracture zone will pass through the construction site. Therefore, it is very important to evaluate and analyze the stability of the unstable block, which is cut by the fault and the dominant joint group. In this study, the discrete element method was used to simulate the seismic response of an underground powerhouse of a hydropower station near a high seismic zone. The discrete fracture network (DFN) model was introduced to simulate the joint group. Moreover, to optimize the number of joints and improve computational efficiency under dynamic conditions, the joints in the DFN with little influence on the stability of the cavity, were deleted by the algorithm, and a nonlinear time-history response analysis method was used for dynamic calculation. Based on the simulation results obtained, it was possible to classify the instability of the unstable block, and corresponding suggestions for construction were provided. Additionally, these results can be used as a reference for the seismic design of similar underground structures.
Modeling investigation of the impacts of dead-end fracture on heat transfer of water flowing through rough fractured rocks
Authors: Chen Yuedu
Published: November 2020

A clear understanding of the convective heat transfer characteristics of fluid in three-dimensional (3D) rock fractures affected by dead-end fractures is important in evaluating heat recovery in fractured geothermal reservoirs. Two 3D cubic fractured rock models with and without rough dead-end fractures are built to conduct flow and heat transfer simulations by solving hydrothermal coupling equations. The rough fractures are upscaled from lab-measured small-scale rock fractures. Injection velocities of 0.002 m/s and 0.02 m/s were imposed to examine how dead-end fractures affect the heat transfer processes within hot fractured rocks. Several characteristic parameters, including outlet water temperature, total heat extraction, and overall permeability, are presented to quantitatively describe the effects of dead-end fractures. Results show that dead-end fractures retard fluid flow through the fractured model and significantly decrease the overall permeability. A low-temperature zone grows rapidly under the effect of dead-end fractures, and the outlet water temperature is lower in this case than in the model without dead-end fractures. Moreover, the total heat extraction is higher in the model without dead-end fractures than in the model with dead-end fractures. This result is mainly ascribed to the former model’s large overall permeability. Results reveal that dead-end fractures cannot be ignored in the evaluation of flow and heat transfer in the modeling of heat extraction from subsurface fractured geothermal reservoirs.