bluuebunny/crossref_metadata_2025 huggingface dataset:
MoS2/pentacene hybrid complementary inverter based photodetector with amplified voltage–output
Authors: Liu Fengjing , Zhang Yiwei , Wang Jiawei , Chen Yiyi , Wang Liang , Wang Gongtang , Dong Ji , Jiang Chao
Published: September 2020

A sensitive photodetection based on a novel hybrid CMOS inverter has been demonstrated. Unlike common photo-current type photodetectors, which convert optical signals to current, the CMOS inverter realizes voltage–output, overcoming the difficulty to monitor current signal in the range of nA. The hybrid CMOS logic inverter employs n-channel MoS2 nanosheet/perovskite heterojunction FET and p-channel organic pentacene FET in a planar architecture. In order to obtain high performance, we adopt the interdigital electrodes for the pentacene FET to enhance the current density of the p-channel, and stack perovskite on the MoS2 channel to modify the threshold voltage of the n-channel. As a result, a CMOS inverter with a voltage gain of more than ten is obtained. When VIN is around the transition voltage (−38 V), the inverter can obtain stable optical detection signal, the VOUT changes from 6 V in dark to 1 V under 633 nm light exposure. This finding indicates the potential to fabricate visible light detecting devices with voltage–output based on the inverter and may be further applicable for a photo-logic circuit.
Bayesian non-linear regression with spatial priors for noise reduction and error estimation in quantitative MRI with an application in T1 estimation
Authors: Löfstedt Tommy , Hellström Max , Bylund Mikael , Garpebring Anders
Published: September 2020

Purpose. To develop a method that can reduce and estimate uncertainty in quantitative MR parameter maps without the need for hand-tuning of any hyperparameters. Methods. We present an estimation method where uncertainties are reduced by incorporating information on spatial correlations between neighbouring voxels. The method is based on a Bayesian hierarchical non-linear regression model, where the parameters of interest are sampled, using Markov chain Monte Carlo (MCMC), from a high-dimensional posterior distribution with a spatial prior. The degree to which the prior affects the model is determined by an automatic hyperparameter search using an information criterion and is, therefore, free from manual user-dependent tuning. The samples obtained further provide a convenient means to obtain uncertainties in both voxels and regions. The developed method was evaluated on T
1 estimations based on the variable flip angle method. Results. The proposed method delivers noise-reduced T
1 parameter maps with associated error estimates by combining MCMC sampling, the widely applicable information criterion, and total variation-based denoising. The proposed method results in an overall decrease in estimation error when compared to conventional voxel-wise maximum likelihood estimation. However, this comes with an increased bias in some regions, predominately at tissue interfaces, as well as an increase in computational time. Conclusions. This study provides a method that generates more precise estimates compared to the conventional method, without incorporating user subjectivity, and with the added benefit of uncertainty estimation.
Towards real-time 4D radiation dosimetry on an MRI-Linac
Authors: De Deene Y , Wheatley M , Dong B , Roberts N , Jelen U , Waddington D , Liney G
Published: September 2020

4D radiation dosimetry using a highly radiation-sensitive polymer gel dosimeter with real-time quantitative magnetic resonance imaging (MRI) readout is presented as a technique to acquire the accumulated radiation dose distribution during image-guided radiotherapy on an MRI-Linac. Optimized T
2-weighted Turbo-Spin-Echo (TSE) scans are converted into quantitative ΔR
2 maps and subsequently to radiation dose maps.

The concept of temporal uncertainty is introduced as a metric of effective temporal resolution. A mathematical framework is presented to optimize the echo time of the TSE sequence in terms of dose resolution, and the trade-off between temporal resolution and dose resolution is discussed. The current temporal uncertainty achieved with the MAGAT gel dosimeter on a 1 T MRI-Linac is 3.8 s which is an order of magnitude better than what has been achieved until now.

The potential of real-time 4D radiation dosimetry in a theragnostic MRI-Linac is demonstrated for two scenarios: an irradiation with three coplanar beams on a head phantom and a dynamic arc treatment on a cylindrical gel phantom using a rotating couch. The dose maps acquired on the MRI-Linac are compared with a treatment plan and with dose maps acquired on a clinical 3 T MRI scanner. 3D gamma map evaluations for the different modalities are provided. While the presented method demonstrates the potential of gel dosimetry for tracking the dose delivery during radiotherapy in 4D, a shortcoming of the MAGAT gel dosimeter is a retarded dose response.

The effect of non-ideal radiofrequency pulses resulting from limitations in the specific absorption rate or B1-field inhomogeneity on the TSE acquired ΔR
2 values is analysed experimentally and by use of computational modelling with a Bloch simulator.
Effect of ferroelectric parameters variation on the characteristics of polarity controllable–ferroelectric–field-effect transistors at elevated temperatures
Authors: Pandey Priyanka , Kaur Harsupreet
Published: September 2020

In the present work, detailed analyses are carried out to study the impact of temperature on the device performance of a single-gated polarity-controllable–ferroelectric–field-effect transistor (PC–FE–FET). Further, the impact of unintentional variations (≤±5%) in ferroelectric (FE) material parameters are extensively investigated. Various device characteristics are studied by implementing the baseline approach. Due to the integration of an FE layer, the proposed device shows remarkable improvements in current drivability, transconductance and transconductance generation factor, and even at elevated temperatures, sub-60 subthreshold swing values are achieved in comparison to the conventional polarity-controllable–FET (PC-FET) for both n- and p-modes of operation. It is demonstrated that the PC–FE–FET shows remarkable stability towards variations in FE parameters.
Mitigating decoherence in hot electron interferometry
Authors: Clark Lewis A , Kataoka Masaya , Emary Clive
Published: September 2020

Due to their high energy, hot electrons in quantum Hall edge (QHE) states can be considered as single particles that have the potential to be used for quantum optics-like experiments. Unlike photons, however, electrons typically undergo scattering processes in transport, which results in a loss of coherence and limits their ability to show quantum-coherent behaviour. Here we study theoretically the decoherence mechanisms of hot electrons in a Mach–Zehnder interferometer (MZI), and highlight the role played by both acoustic and optical phonon emission. We discuss optimal choices of experimental parameters and show that high visibilities of ≳ 85% are achievable in hot-electron devices over relatively long distances of 10 μm. We also discuss energy filtration techniques to remove decoherent electrons and show that this can increase visibilities to over 95%. This represents an improvement over Fermi-level electron quantum optics, and suggests hot-electron charge pumps as a platform for realising quantum-coherent nanoelectronic devices.
Influence of field of view in visual prostheses design: Analysis with a VR system
Authors: Sanchez-Garcia Melani , Martinez-Cantin Ruben , Bermudez-Cameo Jesus , Guerrero Jose J
Published: September 2020

Objective. Visual prostheses are designed to restore partial functional vision in patients with total vision loss. Retinal visual prostheses provide limited capabilities as a result of low resolution, limited field of view and poor dynamic range. Understanding the influence of these parameters in the perception results can guide prostheses research and design. Approach. In this work, we evaluate the influence of field of view with respect to spatial resolution in visual prostheses, measuring the accuracy and response time in a search and recognition task. Twenty-four normally sighted participants were asked to find and recognize usual objects, such as furniture and home appliance in indoor room scenes. For the experiment, we use a new simulated prosthetic vision system that allows simple and effective experimentation. Our system uses a virtual-reality environment based on panoramic scenes. The simulator employs a head-mounted display which allows users to feel immersed in the scene by perceiving the entire scene all around. Our experiments use public image datasets and a commercial head-mounted display. We have also released the virtual-reality software for replicating and extending the experimentation. Main results. Results show that the accuracy and response time decrease when the field of view is increased. Furthermore, performance appears to be correlated with the angular resolution, but showing a diminishing return even with a resolution of less than 2.3 phosphenes per degree. Significance. Our results seem to indicate that, for the design of retinal prostheses, it is better to concentrate the phosphenes in a small area, to maximize the angular resolution, even if that implies sacrificing field of view.
Assessing energy dependence of the transport of relativistic electrons in perturbed magnetic fields with orbit-following simulations
Authors: Särkimäki Konsta , Embreus Ola , Nardon Eric , Fülöp Tünde , contributors JET
Published: September 2020

Experimental observations, as well as theoretical predictions, indicate that the transport of energetic electrons decreases with energy. This reduction in transport is attributed to finite orbit width (FOW) effects. Using orbit-following simulations in perturbed tokamak magnetic fields that have an ideal homogeneous stochastic layer at the edge, we quantify the energy dependence of energetic electrons transport and confirm previous theoretical estimates. However, using magnetic configurations characteristic of JET disruptions, we find no reduction in runaway electron transport at higher energies, which we attribute to the mode widths being comparable to the minor radius, making the FOW effects negligible. Instead, the presence of islands and non-uniform magnetic perturbations are found to be more important. The diffusive-advective transport coefficients calculated in this work, based on simulations for electron energies 10 keV–100 MeV, can be used in integrated disruption modelling to account for the transport due to the magnetic field perturbations.
The cost-effectiveness of energy savings through water conservation: a utility-scale assessment
Authors: Spang Edward S , Manzor Soraya , Loge Frank J
Published: September 2020

It is well-established that water infrastructure systems require energy to treat and deliver water to end-users. This fundamental relationship presents an opportunity to secure energy savings through water conservation. In a previous study, the energy savings linked to a statewide water conservation mandate in California were found comparable in both resource savings as well as cost-effectiveness to the energy savings achieved directly through energy efficiency programs. This study pursues a similar line of inquiry, but at the scale of an individual city as opposed to a statewide assessment. Los Angeles, California, serves as the case study for estimating the energy savings secured through water conservation programs relative to energy efficiency (EE) programs enacted in the study region. We apply three different estimates of energy intensity (EI) for the conversion of water savings to energy savings. These applied EI scenarios are differentiated by scale and system boundary, including: a direct assessment of EI within the water utility service territory, an expanded boundary that includes imported water infrastructure systems, and a broader, top-down estimate for the regional hydrologic zone. Across all scenarios, the estimated energy savings secured through water conservation programs prove to be cost-competitive with the energy efficiency programs enacted by the utility. When using estimates of EI with expanded system boundaries that include the upstream energy embedded in imported water supplies, water conservation becomes a significantly more attractive pathway for saving energy. This outcome underlines the importance of clearly defining the water-energy system boundary of interest, both to determine an accurate EI value, and subsequently, to design and implement cost-effective programs that jointly conserve both water and energy resources.
Boundedness of meta-conformal two-point functions in one and two spatial dimensions
Authors: Henkel Malte , Kuczynski Michal Dariusz , Stoimenov Stoimen
Published: September 2020

Meta-conformal invariance is a novel class of dynamical symmetries, with dynamical exponent z = 1, and distinct from the standard ortho-conformal invariance. The meta-conformal Ward identities can be directly read off from the Lie algebra generators, but this procedure implicitly assumes that the co-variant correlators should depend holomorphically on time- and space coordinates. Furthermore, this assumption implies un-physical singularities in the co-variant correlators. A careful reformulation of the global meta-conformal Ward identities in a dualised space, combined with a regularity postulate, leads to bounded and regular expressions for the co-variant two-point functions, both in d = 1 and d = 2 spatial dimensions.
Pore colmatation in case of liquid corrosion of concrete
Authors: Fedosov S V , Rumyantseva V Eu , Konovalova V S , Evsyakov A S
Published: September 2020

Pore colmatation plays a positive role, since a decrease in the permeability of cement concrete due to the deposition of insoluble corrosion products in the pores leads to a slowdown in corrosion processes. To test a mathematical model of pore colmatation of cement concretes under liquid corrosion, a study of mass transfer processes occurring when samples from Portland cement are exposed to a liquid aggressive medium was conducted. The article presents equations that allow us to determine the rate of pore colmatation and the thickness of the layer of colmatant formed in the pores during liquid corrosion of cement concretes. Based on the results of experimental studies of liquid corrosion of cement stone, the mass transfer parameters were determined in the investigated system «cement concrete – 2 % MgCl2 solution». Based on the obtained data, the values of the colmatation rate and the thickness of the layer of colmatant of cement concrete were calculated during liquid corrosion in a 2 % MgCl2 solution. It has been established that over time, the rate of mass transfer processes occurring in concrete decreases due to the difficulty of penetration of aggressive medium deep into concrete due to the deposition of corrosion products in the pores.
Cement based foam concrete with hardening accelerators
Authors: Steshenko A B , Kudyakov A I , Ryabtseva N E
Published: September 2020

The results of studies of the effect of hardening accelerators on the properties of cement based foam concrete mix and foam concrete of natural hardening are given in this article. The study was conducted in the Laboratory of Tomsk State University of Architecture and Building which is accredited in accordance with the national standards requirements. It has been proposed to decrease the shrinkage deformations of the concrete mix and increase compressive strength of hardened foam concrete by affecting the cement matrix with the calcium chloride and calcium oxalate in the amount of 2 and 0.5% of the cement mass, respectively. This increases the aggregative stability and reduces the plastic shrinkage of the foam concrete mix by 47-65%. In foam concrete with the hardening accelerators the compressive strength rises from 0.31 to 0.47 MPa and from 0.96 to 1.44 MPa at the age of 28 days while maintaining the average density of D400 and D600 respectively. The developed composition of cement based foam concrete is recommended for constructing monolithic walls at a construction site or wall blocks in factory conditions for individual housing construction.
Optical properties of sol-gel coatings containing silver nanoparticles
Authors: Stepin S N , Xolmurodov T A , Mirzaev O O , Katnov V E
Published: September 2020

The technology of receiving the antireflective coating increasing efficiency of use of sunlight in various service conditions is described. Suspensions of nanodimensional silicon dioxide with tetraethoxysilane as a precursor were synthesized to solve the assigned task. The received suspensions were applied by a dipping method on glass samples followed by the coating formation on a surface of the substrates at various temperatures. As a result of a cure of the received samples under natural conditions transparent film of about 500 nanometers thick having very low strength properties on the surface of glass were formed. Heat treatment led to the improvement of strength of coatings in process with increase of temperature up to 600 °C. Exceeding of this temperature resulted in cracking of coatings. In the course of heat treatment higher than 300 °C formation of a coating was accompanied by the thermolysis of silver nitrate that was introduced into silicon dioxide suspension with a formation of silver particles which size was in the nanoscale distance limits according to the results of Auger electron spectroscopy. Presence of evenly distributed silver nanoparticles provided an antireflective effect to coatings which at visual observation found expression in the form of the interference phenomenon. The obtained data confirmed prospects of use of nanosilver as a component of coatings on the basis of silicon dioxide in order to confer the antireflective properties.
Insitu determination of continuous evolution in space and during the strain fields on steel plate with the stress concentrator
Authors: Vlasov V A , Plyaskin A S , Klopotov A A , Potekayev A I , Ustinov A M , Abzayev Yu A , Kurgan A , Bunkov V E , Matskevich N A
Published: September 2020

The article represents the results of the experimental research of the evolution of strain fields of a steel plate with a stress concentrator by the correlation method of digital images. The obtained results reflect elaborately the evolution of the distribution of isofields towards the strains on the surface of the steel plate and the behavior of their distributions, which corresponds to each stage of the stress-strain curve under uniaxial tension.
Role of temperature factor in the work of a cellular reinforced concrete ice-resistant platform
Authors: Zimnyukov V A , Zborovskaya M I
Published: September 2020

The article presents materials reflecting the results of calculations by the finite element method on a computer (according to a special program) of the thermal state of the cellular fragment of the reinforced concrete support block LSP taking into account the influence of seasonal and decadal outdoor temperatures, as well as the effect of changes in the thermal characteristics of the backfill soil on the thermal state of the ice-resistant stationary platform. This made it possible for the first time to evaluate the joint work of a thin reinforced concrete frame and a massive body of backfill soil under temperature effects. In the case of the operation of the cellular structure without the backfill soil, seasonal and ten-day temperature fluctuations create a more unfavourable temperature regime in comparison with the cellular structure with the backfill soil. In the absence of backfill soil, negative temperatures penetrate most deeply into the thickness of the structure. The presented data can also serve as the basis for a preliminary assessment of the thermal state of LSP in the form of a fully cellular reinforced concrete structure and in the future to determine its thermally stressed state. Only considering the combined effect of ice, wave and temperature loads can we really evaluate the operation of such a complex structure in terms of its reliability and safety.
Formation of a comfortable urban environment, taking into account the reconstruction, restoration of buildings and structures (on the example of the Kaliningrad region)
Authors: Pustovgarov V I
Published: September 2020

The issues of reconstruction of the historical environment of cities are one of the most acute when considering the problems of development of urbanized territories. A significant number of examples of the loss of historical monuments make it especially careful to the preserved architectural heritage. The process of revitalizing the planning of the territory in the area of the South (Yuzhniy) Station in the city of Kaliningrad is due to the incompleteness of the town-planning ensemble, which began to form at the end of the 19th century. Urban planning reconstruction of the territory is a complex of necessary scientific research and the preparation of a historical and cultural reference plan, which is defined by the Federal Law “On cultural heritage sites (historical and cultural monuments) of the peoples of the Russian Federation” [1]. As a result of studying the stages of urban development of the historical territory of the city and analyzing its architectural and spatial organization, conceptual proposals for its development were developed.
The process and project approach as the basis for harmonization of development management system of a construction company
Authors: Dorofeeva V V , Kaverzina L A , Nuzhina I P
Published: September 2020

The article is devoted to development of theoretical positions as well as methodical and practical base for increasing the efficiency of cost management of construction project realization. The modernized organization and economic mechanism of formation and cost management of the construction project realization is proposed. This mechanism is determined as integrated system of planning and control for the cost of construction project realization. The main directions of harmonization of components of company’s development due management system due to the process and project approach that combines advantages of value-oriented management and methodology of project management are indicated.
Polyatomic molecules as quantum sensors for fundamental physics
Authors: Hutzler Nicholas R
Published: September 2020

Precision measurements in molecules have advanced rapidly in recent years through developments in techniques to cool, trap, and control. The complexity of molecules makes them a challenge to study, but also offers opportunities for enhanced sensitivity to many interesting effects. Polyatomic molecules offer additional complexity compared to diatomic molecules, yet are still ‘simple’ enough to be laser-cooled and controlled. While laser cooling molecules is still a research frontier itself, there are many proposed and ongoing experiments seeking to combine the advanced control enabled by ultracold temperatures with the intrinsic sensitivity of molecules. In this perspective, we discuss some applications where laser-cooled polyatomic molecules may offer advantages for precision measurements of fundamental physics, both within and beyond the Standard Model.
The average value of the spin squared operator as an order parameter for spin phase transitions without spontaneous lowering of symmetry
Authors: Kalita V M , Levchenko G G
Published: September 2020

Phase transitions from the low-spin to the high-spin state are a unique physical phenomenon without lowering of symmetry. In contrast to magnetic phase transitions, for which vector or tensor of physical quantities are used as order parameters, we have shown that for spin phase transitions the order parameter is a scalar quantity—the thermodynamic mean of spin square operator, which was not previously used at all in the theory of phase transitions. The free energy in the form of a functional of this order parameter is determined, and the phase diagrams for spin transitions are constructed. The influence of the pressure on spin transition is analyzed also. It is shown that the spin Hamiltonian with this order parameter allows one to obtain all possible spin transformations in compounds. At the same time, this order parameter correctly reflects the physical nature of the spin transition phenomena.
Solution plasma: new synthesis method of N-doped carbon dots as ultra-sensitive fluorescence detector for 2,4,6-trinitrophenol
Authors: Kim Kyusung , Chokradjaroen Chayanaphat , Saito Nagahiro
Published: September 2020

Herein, we report the synthesis of nitrogen-doped carbon dots (NCDs) through solution plasma (SP) for the first time. The SP method occurs a rapid dissociation of molecules, such as organic compounds, caused by an electrical discharge between electrodes immersed in a solution. The dissociation can result in the creation of various radicals such as ·C2, ·CN, and ·H which enable the rapid synthesis of carbon dots (CDs). The unique reaction of radicals allowed the formation of CDs with high N concentration and functionalization of the surface in a short time. In this study, by using the SP method, a very fine NCDs with size of 6 nm were synthesized from a pyridine/water mixture in just 10 min. Bright blue fluorescence (410 nm) with a high quantum yield (61%) was observed due to the high N concentration and the surface passivation. From the potential application point of view, the synthesized NCDs showed an excellent detection property for 2,4,6-trinitrophenol (TNP) by fluorescence quenching effect. It was due to rich amino-functional groups which act as a reaction pathway to TNP. This phenomenon was caused by the synergetic effect of a photo-induced electron transfer with the assistance of proton transfer-assisted electron transfer.
Perivascular Epithelioid Cell Tumor of Urinary Bladder
Authors: Wu You-li , Lang Lang , Ma Qiang , Wu Feng , Zhang Yu , Chen Wei , Yan Xiao-chu , Duan Guang-jie
Published: September 2020

Objectives

To review the clinicopathologic features of perivascular epithelioid cell tumor (PEComa) of the urinary bladder.

Methods

Seven cases of bladder PEComa were studied by light microscopy, immunohistochemistry, and fluorescence in situ hybridization (FISH).

Results

In our 7 cases, 5 patients were female and 2 were male, with ages between 26 and 78 years. Patients presented with hematuria and recurrent abdominal discomfort as the main clinical symptoms. Microscopically, the epithelioid and spindle-shaped tumor cells with clear to granular eosinophilic cytoplasm were arranged in fascicular, acinar, or nested patterns. The tumor cells were positive for HMB45, melan-A, and SMA, but no TFE3 gene rearrangement was detected in any of the 7 samples by FISH. The analysis of all 35 cases from the literature and ours showed a patient age range from 16 to 78 years (mean age, 39 years), a male-to-female ratio of 1:1.3, maximal tumor diameters from 0.6 to 18.8 cm (mean, 4.5 cm). With a mean follow-up of 27 months, the recurrence, metastasis, and mortality rates were 10.7%, 10.7%, and 7.1%, respectively.

Conclusions

Bladder PEComa is extremely rare, remains a diagnostic challenge, and needs more attention. Strengthening the understanding of this tumor will improve diagnostic accuracy.
Reprinting the Past/Re-Ordering Black Social Life
Authors: Womack Autumn
Published: September 2020

This essay recovers the cultural and political history of Arno Press’s landmark republication project, The American Negro: His History and Literature. Within the context of the “reprint revolution,” the period when large publishing houses clamored to publish African American texts, many of which had long been out of print, and with the backing of The New York Times, Arno Press reissued hundreds of titles by and about Black life. While these titles have come to shape the contours of African American literary scholarship, the project was immediately ensnared within debates about the future of Black political life. Knitting together personal correspondence, advertisements, and reviews, this essay situates the Arno Press endeavor with a longer history of Black print culture in which the past was harnessed in the name of imagining new political futures. Yet, within the context of the late 1960s “reprint revolution,” I show how the Black past was summoned in the service of a liberal fantasy of assimilation, social management, and racial reform. Drawing a line of connection between the technology of reprinting and its ideological workings, this essay calls for a critical consideration of the labor that we invite Black texts to undertake in the service of particular, and often limited, political visions.
Sample-specific perturbation of gene interactions identifies breast cancer subtypes
Authors: Chen Yuanyuan , Gu Yu , Hu Zixi , Sun Xiao
Published: September 2020

Breast cancer is a highly heterogeneous disease, and there are many forms of categorization for breast cancer based on gene expression profiles. Gene expression profiles are variables and may show differences if measured at different time points or under different conditions. In contrast, biological networks are relatively stable over time and under different conditions. In this study, we used a gene interaction network from a new point of view to explore the subtypes of breast cancer based on individual-specific edge perturbations measured by relative gene expression value. Our study reveals that there are four breast cancer subtypes based on gene interaction perturbations at the individual level. The new network-based subtypes of breast cancer show strong heterogeneity in prognosis, somatic mutations, phenotypic changes and enriched pathways. The network-based subtypes are closely related to the PAM50 subtypes and immunohistochemistry index. This work helps us to better understand the heterogeneity and mechanisms of breast cancer from a network perspective.
CellTalkDB: a manually curated database of ligand–receptor interactions in humans and mice
Authors: Shao Xin , Liao Jie , Li Chengyu , Lu Xiaoyan , Cheng Junyun , Fan Xiaohui
Published: September 2020

Cell–cell communications in multicellular organisms generally involve secreted ligand–receptor (LR) interactions, which is vital for various biological phenomena. Recent advancements in single-cell RNA sequencing (scRNA-seq) have effectively resolved cellular phenotypic heterogeneity and the cell-type composition of complex tissues, facilitating the systematic investigation of cell–cell communications at single-cell resolution. However, assessment of chemical-signal-dependent cell–cell communication through scRNA-seq relies heavily on prior knowledge of LR interaction pairs. We constructed CellTalkDB (http://tcm.zju.edu.cn/celltalkdb), a manually curated comprehensive database of LR interaction pairs in humans and mice comprising 3398 human LR pairs and 2033 mouse LR pairs, through text mining and manual verification of known protein–protein interactions using the STRING database, with literature-supported evidence for each pair. Compared with SingleCellSignalR, the largest LR-pair resource, CellTalkDB includes not only 2033 mouse LR pairs but also 377 additional human LR pairs. In conclusion, the data on human and mouse LR pairs contained in CellTalkDB could help to further the inference and understanding of the LR-interaction-based cell–cell communications, which might provide new insights into the mechanism underlying biological processes.
Low-frequency transcranial stimulation of pre-supplementary motor area alleviates levodopa-induced dyskinesia in Parkinson’s disease: a randomized cross-over trial
Authors: Lohse Allan , Meder David , Nielsen Silas , Lund Anders Elkjær , Herz Damian M , Løkkegaard Annemette , Siebner Hartwig R
Published: September 2020

Levodopa-induced dyskinesia gradually emerges during long-term dopamine therapy, causing major disability in patients with Parkinson disease. Using pharmacodynamic functional MRI, we have previously shown that the intake of levodopa triggers an excessive activation of the pre-supplementary motor area in Parkinson disease patients with peak-of-dose dyskinesia. In this pre-registered, interventional study, we tested whether the abnormal responsiveness of the pre-supplementary motor area to levodopa may constitute a ‘stimulation target’ for treating dyskinesia. A gender-balanced group of 17 Parkinson disease patients with peak-of-dose dyskinesia received 30 min of robot-assisted repetitive transcranial magnetic stimulation, after they had paused their anti-Parkinson medication. Real-repetitive transcranial magnetic stimulation at 100% or sham-repetitive transcranial magnetic stimulation at 30% of individual resting corticomotor threshold of left first dorsal interosseous muscle was applied on separate days in counterbalanced order. Following repetitive transcranial magnetic stimulation, patients took 200 mg of oral levodopa and underwent functional MRI to map brain activity, while they performed the same go/no-go task as in our previous study. Blinded video assessment revealed that real-repetitive transcranial magnetic stimulation delayed the onset of dyskinesia and reduced its severity relative to sham-repetitive transcranial magnetic stimulation. Individual improvement in dyskinesia severity scaled linearly with the modulatory effect of real-repetitive transcranial magnetic stimulation on task-related activation in the pre-supplementary motor area. Stimulation-induced delay in dyskinesia onset correlated positively with the induced electrical field strength in the pre-supplementary motor area. Our results provide converging evidence that the levodopa-triggered increase in pre-supplementary motor area activity plays a causal role in the pathophysiology of peak-of-dose dyskinesia and constitutes a promising cortical target for brain stimulation therapy.
Creatinine and C-reactive protein in amyotrophic lateral sclerosis, multiple sclerosis and Parkinson’s disease
Authors: Cui Can , Sun Jiangwei , Pawitan Yudi , Piehl Fredrik , Chen Honglei , Ingre Caroline , Wirdefeldt Karin , Evans Marie , Andersson John , Carrero Juan-Jesus , Fang Fang
Published: September 2020

Serum creatinine and C-reactive protein have been proposed as potential biomarkers for neurodegenerative diseases, including amyotrophic lateral sclerosis, multiple sclerosis and Parkinson’s disease. However, longitudinal studies investigating temporal patterns of these biomarkers, including the phase before diagnosis, are rare. We performed a case–control study including all newly diagnosed patients with amyotrophic lateral sclerosis (N = 525), multiple sclerosis (N = 1815) or Parkinson’s disease (N = 3797) during 2006–2013 in Stockholm, Sweden, who participated in the Stockholm CREAtinine Measurements (SCREAM) project. For each case, we randomly selected up to five controls from SCREAM that were individually matched to the case by age, sex and county of residence (N = 2625 for amyotrophic lateral sclerosis, N = 9063 for multiple sclerosis and 18 960 for Parkinson’s disease). We collected for both the cases and the controls testing results of serum creatinine and C-reactive protein performed by healthcare providers in Stockholm during the study period. Median levels of creatinine and C-reactive protein were visualized using locally weighted smoothing curves among cases and controls. A linear mixed model was also applied to explore temporal changes within an individual. Compared to controls, patients with amyotrophic lateral sclerosis had lower levels of creatinine from 2 years before diagnosis onwards. In contrast, patients with amyotrophic lateral sclerosis had lower levels of C-reactive protein before diagnosis but higher levels after diagnosis, compared to controls. Focusing the 2 years before to 2 years after diagnosis, patients with amyotrophic lateral sclerosis displayed statistically significantly decreasing level of creatinine from 1 year before diagnosis until 2 years after diagnosis, whereas increasing level of C-reactive protein from diagnosis until 2 years after diagnosis. There were no similar patterns noted among patients with multiple sclerosis or Parkinson’s disease, or the controls of the three patient groups. Patients with amyotrophic lateral sclerosis display distinct temporal patterns of creatinine and C-reactive protein before and after diagnosis, compared to amyotrophic lateral sclerosis-free controls or patients with multiple sclerosis and Parkinson’s disease.
Choline Metabolism and Risk of Atrial Fibrillation and Heart Failure in the PREDIMED Study
Authors: Papandreou Christopher , Bulló Mònica , Hernández-Alonso Pablo , Ruiz-Canela Miguel , Li Jun , Guasch-Ferré Marta , Toledo Estefanía , Clish Clary , Corella Dolores , Estruch Ramon , Ros Emilio , Fitó Montserrat , Alonso-Gómez Angel , Fiol Miquel , Santos-Lozano José M , Serra-Majem Lluís , Liang Liming , Martínez-González Miguel A , Hu Frank B , Salas-Salvadó Jordi
Published: September 2020

Background

Few studies have examined the associations of trimethylamine-N-oxide (TMAO) and its precursors (choline, betaine, dimethylglycine, and L-carnitine) with the risk of atrial fibrillation (AF) and heart failure (HF). This study sought to investigate these associations.

Methods

Prospective associations of these metabolites with incident AF and HF were examined among participants at high cardiovascular risk in the PREDIMED study (PREvención con DIeta MEDiterránea) after follow-up for about 10 years. Two nested case-control studies were conducted, including 509 AF incident cases matched to 618 controls and 326 HF incident cases matched to 426 controls. Plasma levels of TMAO and its precursors were semi-quantitatively profiled with liquid chromatography tandem mass spectrometry. Odds ratios were estimated with multivariable conditional logistic regression models.

Results

After adjustment for classical risk factors and accounting for multiple testing, participants in the highest quartile vs. the lowest quartile of baseline choline and betaine levels had a higher risk of AF [OR (95% CI): 1.85 (1.30–2.63) and 1.57 (1.09–2.24), respectively]. The corresponding OR for AF for extreme quartiles of dimethylglycine was 1.39 (0.99–1.96). One SD increase in log-transformed dimethylglycine was positively associated with AF risk (OR, 1.17; 1.03–1.33). The corresponding ORs for HF for extreme quartiles of choline, betaine, and dimethylglycine were 2.51 (1.57–4.03), 1.65 (1.00–2.71) and 1.65 (1.04–2.61), respectively. TMAO and L-carnitine levels were not associated with AF or HF.

Conclusions

Our findings support the role of the choline metabolic pathway in the pathogenesis of AF and HF.
The effects of cold shock on freshwater fish larvae and early-stage juveniles: implications for river management
Authors: Michie Laura E , Thiem Jason D , Boys Craig A , Mitrovic Simon M
Published: September 2020

Temperature is essential to the maintenance of optimal physiological functioning in aquatic organisms. Fish can manage natural fluctuations in temperature; however, in freshwater ecosystems acute and rapid temperature changes can originate from sources such as large dams and industrial effluents. These rapid temperature changes may induce several physiological and behavioural responses that can result in lethal and sub-lethal consequences. The present study assessed immediate sub-lethal and short-term (10 days) lethal responses of three species of Australian freshwater fish larvae and early-stage juveniles to a range of different ‘field-relevant’ cold shocks (−4, −6, −8 and −10°C). Murray cod (Maccullochella peelii), silver perch (Bidyanus bidyanus) and golden perch (Macquaria ambigua) were tested at two age groups to elucidate the interaction between ontogeny and sensitivity to cold shock. Cold shock caused mortality and reductions in swimming ability (time to exhaustion and lines crossed) in all species of fish at both age groups. Sensitivity was correlated to the magnitude of cold shock; a 10°C drop in temperature caused the highest mortalities. Ontogeny interacted with the severity of cold shock; the younger fish experienced higher mortalities and greater impairment to swimming ability. This study demonstrates the potential lethal and sub-lethal impacts of cold shock on freshwater fish at a critical life-history stage. Understanding the impacts of cold shock will aid management of freshwater ecosystems for the benefit of fish populations, with the current study identifying critical life stages to be considered in remediation and guiding thresholds necessary to reduce the impact of cold shock on native fish populations.
Diversity and genetic lineages of environmental staphylococci: a surface water overview
Authors: Silva Vanessa , Caniça Manuela , Capelo José L , Igrejas Gilberto , Poeta Patrícia
Published: September 2020

Antimicrobial resistance in the environmental dimension is one of the greatest challenges and emerging threats. The presence of resistant bacteria and resistance genes in the environment, especially in aquatic systems, has been a matter of growing concern in the past decade. Monitoring the presence of antimicrobial resistance species, in this particular case, Staphylococcus spp., in natural water environments could lead to a better understanding of the epidemiology of staphylococci infections. Thus, the investigation of natural waters as a potential reservoir and vehicle for transmission of these bacteria is imperative. Only a few studies have investigated the prevalence, antimicrobial resistance and genetic lineages of staphylococci in natural waters. Those studies reported a high diversity of staphylococci species and lineages in surface waters. Methicillin-resistant S. aureus were relatively prevalent in surface waters and, as expected, often presented a multidrug-resistant profile. There was a high diversity of S. aureus lineages in surface waters. The presence of S. aureus CC8 and CC5 suggests a human origin. Among the coagulase-negative staphylococci, the most frequently found in natural waters was S. warneri and S. epidermidis. These studies are extremely important to estimate the contribution of the aquatic environment in the spread of pathogenic bacteria.
Soil fungal community composition and functional similarity shift across distinct climatic conditions
Authors: Bui An , Orr Devyn , Lepori-Bui Michelle , Konicek Kelli , Young Hillary S , Moeller Holly V
Published: September 2020

A large part of ecosystem function in woodland systems depends on soil fungal communities. However, global climate change has the potential to fundamentally alter these communities as fungal species are filtered with changing environmental conditions. In this study, we examined the potential effects of climate on host-associated (i.e. tree-associated) soil fungal communities at climatically distinct sites in the Tehachapi Mountains in California, where more arid conditions represent likely regional climate futures. We found that soil fungal community composition changes strongly across sites, with species richness and diversity being highest at the most arid site. However, host association may buffer the effects of climate on community composition, as host-associated fungal communities are more similar to each other across climatically distinct sites than the whole fungal community. Lastly, an examination of functional traits for ectomycorrhizal fungi, a well-studied guild of fungal mutualist species, showed that stress-tolerant traits were more abundant at arid sites than mesic sites, providing a mechanistic understanding of these community patterns. Taken together, our results indicate that fungal community composition will likely shift with future climate change but that host association may buffer these effects, with shifts in functional traits having implications for future ecosystem function.
Galleria mellonella as an infection model: an in-depth look at why it works and practical considerations for successful application
Authors: Pereira Monalessa Fábia , Rossi Ciro César , da Silva Giarlã Cunha , Rosa Jéssica Nogueira , Bazzolli Denise Mara Soares
Published: September 2020

The larva of the greater wax moth Galleria mellonella is an increasingly popular model for assessing the virulence of bacterial pathogens and the effectiveness of antimicrobial agents. In this review, we discuss details of the components of the G. mellonella larval immune system that underpin its use as an alternative infection model, and provide an updated overview of the state of the art of research with G. mellonella infection models to study bacterial virulence, and in the evaluation of antimicrobial efficacy. Emphasis is given to virulence studies with relevant human and veterinary pathogens, especially Escherichia coli and bacteria of the ESKAPE group. In addition, we make practical recommendations for larval rearing and testing, and overcoming potential limitations of the use of the model, which facilitate intra- and interlaboratory reproducibility.
The Impact of Distal Influences and Proximal Resources on the Mental Health of African American Older Adults: Findings From the Georgia Centenarian Study
Authors: Johnson Nicholson Meneka C , Martin Peter , Gilligan Megan , Cutrona Carolyn E , Russell Daniel W , Schofield Tom J , Poon Leonard W
Published: September 2020

Background and Objectives

Over the years, a large amount of research has been devoted to the investigation of factors that led to mental health outcomes in older adults. For African American older adults, their lived experiences place them at high risk for mental health problems. The purpose of this study was to examine the impact of early life influences (i.e., education, childhood life events, and childhood financial well-being) and present psychosocial resources (i.e., individual, financial, and social) on current mental health outcomes in a sample of African American older adults in their 60s, 80s, and 100s.

Research Design and Methods

Using data from the Georgia Centenarian Study, 125 participants were interviewed about their mental health, resources, and early life influences.

Results

A structural equation model was tested and resulted in a good fit. Results indicated that the more social resources African American older adults had available, the lower the number of depressive symptoms they reported. African Americans with higher levels of financial well-being during childhood reported higher self-rated mental health. Older adults had higher levels of financial resources. Level of education showed a positive relationship with financial resources. Indirect effects of distal influences on health outcomes via current resources were not found.

Discussion and Implications

The findings are of direct practical relevance and can be used to more readily identify older African Americans who may be susceptible to poorer mental health outcomes based upon the impact of their unique distal and proximal psychosocial resources.