6,423 results match your criteria experiments systematically


Cutaneous Sensation of Electrical Stimulation Waveforms.

Brain Stimul 2021 Apr 10. Epub 2021 Apr 10.

Department of Biomedical Engineering, The City College of New York, CUNY, 160 Convent Avenue, New York, NY, USA.

Background: Skin sensation is the primary factor limiting the intensity of transcranial electrical stimulation (tES). It is well established that different waveforms generate different sensations, yet transcranial stimulation has been limited to a relatively small number of prototypical waveforms.

Objective: We explore whether alternative stimulation waveforms could substantially reduce skin sensation and thus allow for stronger intensities in tES. Read More

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Coupling between the phase of a neural oscillation or bodily rhythm with behavior: evaluation of different statistical procedures.

Neuroimage 2021 Apr 10:118050. Epub 2021 Apr 10.

Laboratoire de Neurosciences Cognitives et Computationnelles, Ecole Normale Supérieure, Inserm u960, PSL University, Paris, France.

Growing experimental evidence points at relationships between the phase of a cortical or bodily oscillation and behavior, using various circular statistical tests. Here, we systematically compare the performance (sensitivity, False Positive rate) of four circular statistical tests (some commonly used, i.e. Read More

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Impact of chromatin context on Cas9-induced DNA double-strand break repair pathway balance.

Mol Cell 2021 Apr 6. Epub 2021 Apr 6.

Oncode Institute, Netherlands Cancer Institute, 1066 CX, Amsterdam, the Netherlands; Division of Gene Regulation, Netherlands Cancer Institute, 1066 CX, Amsterdam, the Netherlands; Department of Cell Biology, Erasmus University Medical Centre, 3015 CN, Rotterdam, the Netherlands. Electronic address:

DNA double-strand break (DSB) repair is mediated by multiple pathways. It is thought that the local chromatin context affects the pathway choice, but the underlying principles are poorly understood. Using a multiplexed reporter assay in combination with Cas9 cutting, we systematically measure the relative activities of three DSB repair pathways as a function of chromatin context in >1,000 genomic locations. Read More

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Abundance and size of hyaluronan in naked mole-rat tissues and plasma.

Sci Rep 2021 Apr 12;11(1):7951. Epub 2021 Apr 12.

Molecular Physiology Research Unit (URPhyM), NARILIS, University of Namur, Namur, Belgium.

Large amounts of ultra-high molecular weight hyaluronan (HA) have been described as the main cause of cancer resistance in naked mole-rats (Heterocephalus glaber, NMR). Our work examined HA metabolism in these rodents more closely. HA was localized and quantified using HA binding proteins. Read More

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Analysis of astaxanthin molecular targets based on network pharmacological strategies.

J Food Biochem 2021 Apr 12:e13717. Epub 2021 Apr 12.

College of Chemistry & Environmental Science, Guangdong Ocean University, Zhanjiang, China.

In order to further explore the potential pharmacological activity of astaxanthin (AST), network pharmacological approaches were employed in this work to systematically investigate its affinity targets, perturbed signaling pathways, and related disease applications. First, potential targets were captured based on AST chemical structure information. Enrichment analysis was then performed using bioinformatics tools to predict the biological processes and diseases in which AST targets are involved. Read More

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The "Missing 6 dB" Revisited: Influence of Room Acoustics and Binaural Parameters on the Loudness Mismatch Between Headphones and Loudspeakers.

Front Psychol 2021 26;12:623670. Epub 2021 Mar 26.

Medizinische Physik and Cluster of Excellence "Hearing4all", Universität Oldenburg, Oldenburg, Germany.

Generations of researchers observed a mismatch between headphone and loudspeaker presentation: the sound pressure level at the eardrum generated by a headphone has to be about 6 dB higher compared to the level created by a loudspeaker that elicits the same loudness. While it has been shown that this effect vanishes if the same waveforms are generated at the eardrum in a blind comparison, the origin of the mismatch is still unclear. We present new data on the issue that systematically characterize this mismatch under variation of the stimulus frequency, presentation room, and binaural parameters of the headphone presentation. Read More

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Explosion behaviors of hybrid CH/CaC dust in a confined space.

J Hazard Mater 2021 Apr 5;416:125783. Epub 2021 Apr 5.

School of Chemical Engineering, Anhui University of Science and Technology, Huainan 232001, PR China; Engineering Laboratory of Explosive Materials and Technology of Anhui Province, Huainan 232001, PR China.

In order to investigate the explosion process of calcium carbide (CaC) dust in the acetylene (CH) atmosphere, the explosion characteristics of CH gas and CH/CaC dust gas-solid two-phase mixture were studied using a 20-L spherical vessel, and the chemical composition of solid residues after explosion were also analyzed. Experimental results showed that the P values of CH gas explosion rose first and then remained stable with the increasing stoichiometric ratio values (φ) of CH/air, while the (dP/dt) values tended to increase at early stage and then decrease, the inflection point of (dP/dt) values was φ = 1.78. Read More

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Force-Sensitive Mat for Vertical Jump Measurement to Assess Lower Limb Strength: Validity and Reliability Study.

JMIR Mhealth Uhealth 2021 Apr 9;9(4):e27336. Epub 2021 Apr 9.

Electrical/Electronics Engineering and Communications Department, EUP Teruel, Universidad de Zaragoza, Teruel, Spain.

Background: Vertical jump height is widely used in health care and sports fields to assess muscle strength and power from lower limb muscle groups. Different approaches have been proposed for vertical jump height measurement. Some commonly used approaches need no sensor at all; however, these methods tend to overestimate the height reached by the subjects. Read More

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Towards Heteroleptic Dicoordinate Cu(II) Complexes.

Chemistry 2021 Apr 8. Epub 2021 Apr 8.

Karlsruher Institut fur Technologie, Institut fur Anorganische Chemie, Engesserstr. 15, Gebaude 30.45, 76131, Karlsruhe, GERMANY.

In this work we detail our efforts to systematically generate stable dicoordinate Cu(II) complexes. Initial experiments via metathesis reactions of a bulky potassium carbazolide (RK) with copper(II) salts indeed yielded a stable product, RCuOTf ( 1 ). However, subsequent attempts to grasp systematic synthetic access to complexes of the type RCuX (X = monoanionic ligand) proved difficult as many of the complexes rapidly decomposed in solution. Read More

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A surface charge governed nanofluidic diode based on a single polydimethylsiloxane (PDMS) nanochannel.

Authors:
Jun Li Dongqing Li

J Colloid Interface Sci 2021 Mar 24;596:54-63. Epub 2021 Mar 24.

Department of Mechanical and Mechatronics Engineering, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada. Electronic address:

Hypothesis: Nanofluidic diodes have attracted intense attention recently. Commonly used materials to design these devices are membrane-based short nanopores and aligned Carbon nanotube bundles. It is highly desirable and very challenging to develop a nanofluidic diode based on a single PDMS nanochannel which is easier to be introduced into an integrated electronic system on a chip. Read More

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Surface charged amino acid-based strategy for rational engineering of kinetic stability and specific activity of enzymes: Linking experiments with computational modeling.

Int J Biol Macromol 2021 Apr 5;182:228-236. Epub 2021 Apr 5.

College of Food Science and Engineering, Ocean University of China, Qingdao 266003, China. Electronic address:

A rational workflow for engineering kinetically stable enzymes with good specific activity by surface charged amino acids engineering was proposed based on systematically analyzing the results of mutating 44 negatively charged surface amino acids of a thermophilic β-mannanase (ManAK). Computational data, combined with experimental results indicated that percentage side-chain solvent accessibility (PSSA), changes in Gibbs free energy of unfolding (∆∆G) and root-mean-square fluctuations (RMSF) could be suitable for screening kinetically stable mutants. A combinational standard (∆∆G < -0. Read More

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Dynamic negativity effects in emotional responding: Onsets, peaks, and influences from repetition.

Emotion 2021 Apr 8. Epub 2021 Apr 8.

Center for Technology and Behavioral Health.

Emotional responses to aversive stimuli may be more mandatory than emotional responses to appetitive stimuli, and extant theorizing suggests that negative reactions may be more peaked at maximum intensity. Parameters of this type were investigated within two experiments (total = 198) in which emotional images were presented and re-presented as participants indicated their moment-to-moment feeling changes in response to both appetitive and aversive images. Negative emotional reactions were more detectable, with more definitive onsets and peaks, and peak amplitudes were systematically higher in the context of aversive stimuli. Read More

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People systematically overlook subtractive changes.

Nature 2021 Apr 7;592(7853):258-261. Epub 2021 Apr 7.

Engineering Systems and Environment, School of Engineering and Applied Science, University of Virginia, Charlottesville, VA, USA.

Improving objects, ideas or situations-whether a designer seeks to advance technology, a writer seeks to strengthen an argument or a manager seeks to encourage desired behaviour-requires a mental search for possible changes. We investigated whether people are as likely to consider changes that subtract components from an object, idea or situation as they are to consider changes that add new components. People typically consider a limited number of promising ideas in order to manage the cognitive burden of searching through all possible ideas, but this can lead them to accept adequate solutions without considering potentially superior alternatives. Read More

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Brain Dynamics and Structure-Function Relationships via Spectral Factorization and the Transfer Function.

Neuroimage 2021 Apr 2:117989. Epub 2021 Apr 2.

School of Physics, University of Sydney, New South Wales 2006, Australia; ARC Center for Integrative Brain Function, University of Sydney, New South Wales 2006, Australia. Electronic address:

It is shown how the brain's linear transfer function provides a means to systematically analyze brain connectivity and dynamics, and to infer connectivity, eigenmodes, and activity measures such as spectra, evoked responses, coherence, and causality, all of which are widely used in brain monitoring. In particular, the Wilson spectral factorization algorithm is outlined and used to efficiently obtain linear transfer functions from experimental two-point correlation functions. The algorithm is tested on a series of brain-like structures of increasing complexity which include time delays, asymmetry, two-dimensionality, and complex network connectivity. Read More

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Controlled aggregation enhances immunomodulatory potential of mesenchymal stromal cell aggregates.

Stem Cells Transl Med 2021 Apr 5. Epub 2021 Apr 5.

Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, Wisconsin, USA.

Human mesenchymal stromal cells (MSCs) are promising candidates for cell therapy due to their ease of isolation and expansion and their ability to secrete antiapoptotic, pro-angiogenic, and immunomodulatory factors. Three-dimensional (3D) aggregation "self-activates" MSCs to augment their pro-angiogenic and immunomodulatory potential, but the microenvironmental features and culture parameters that promote optimal MSC immunomodulatory function in 3D aggregates are poorly understood. Here, we generated MSC aggregates via three distinct methods and compared them with regard to their (a) aggregate structure and (b) immunomodulatory phenotype under resting conditions and in response to inflammatory stimulus. Read More

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Comprehensive Analysis of the Functions and Prognostic Value of RNA-Binding Proteins in Thyroid Cancer.

Front Oncol 2021 17;11:625007. Epub 2021 Mar 17.

The First Department of Breast Cancer, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Tianjin, China.

RNA binding proteins (RBPs) have been proved to play pivotal roles in a variety types of tumors. However, there is no convincible evidence disclosing the functions of RBPs in thyroid cancer (THCA) thoroughly and systematically. Integrated analysis of the functional and prognostic effect of RBPs help better understanding tumorigenesis and development in thyroid and may provide a novel therapeutic method for THCA. Read More

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Sub-nano to nanometer wear and tribocorrosion of titanium oxide-metal surfaces by in situ atomic force microscopy.

Acta Biomater 2021 Mar 31. Epub 2021 Mar 31.

Clemson - MUSC Bioengineering Program, Department of Bioengineering, Clemson University and the Medical University of South Carolina, 68 Presidents Street, Charleston, SC 20425, United States. Electronic address:

Wear and tribocorrosion of passive oxide film covered metals have been studied at the micro and macroscopic scales. Recent advances in nanotechnology have contributed to breakthroughs in understanding of fundamental friction and wear mechanisms of atomically thin 2D materials at the nanoscale. However, for metals and materials without ultra-flat surfaces, a gap in knowledge exists at or below a few nanometers, which is too small for continuum mechanics theories and experiments including conventional atomic force microscopy (AFM) methods, due to resolution limits arising from surface roughness. Read More

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Sulfur amino acids status controls selenium methylation in : Identification of a novel metabolite from promiscuous enzyme reactions.

Appl Environ Microbiol 2021 Apr 2. Epub 2021 Apr 2.

Institute for Ecopreneurship, School of Life Sciences, University of Applied Sciences and Arts Northwestern Switzerland, Hofackerstrasse 30, 4132 Muttenz, Switzerland.

Selenium (Se) deficiency affects many millions of people worldwide, and the volatilization of methylated Se species to the atmosphere may prevent Se from entering the food chain. Despite the extent of Se deficiency, little is known about fluxes in volatile Se species and their temporal and spatial variation in the environment, giving rise to uncertainty in atmospheric transport models. To systematically determine fluxes, one can rely on laboratory microcosm experiments to quantify Se volatilization in different conditions. Read More

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Modeling of a Rope-Driven Piezoelectric Vibration Energy Harvester for Low-Frequency and Wideband Energy Harvesting.

Micromachines (Basel) 2021 Mar 15;12(3). Epub 2021 Mar 15.

Department of Mechanical and Electrical Engineering, Xiamen University, Xiamen 361005, China.

In this work, a mechanical model of a rope-driven piezoelectric vibration energy harvester (PVEH) for low-frequency and wideband energy harvesting was presented. The rope-driven PVEH consisting of one low-frequency driving beam (LFDB) and one high-frequency generating beam (HFGB) connected with a rope was modeled as two mass-spring-damper suspension systems and a massless spring, which can be used to predict the dynamic motion of the LFDB and HFGB. Using this model, the effects of multiple parameters including excitation acceleration, rope margin and rope stiffness in the performance of the PVEH have been investigated systematically by numerical simulation and experiments. Read More

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Secondary Structure Libraries for Artificial Evolution Experiments.

Molecules 2021 Mar 17;26(6). Epub 2021 Mar 17.

The Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, 166 10 Prague, Czech Republic.

Methods of artificial evolution such as SELEX and in vitro selection have made it possible to isolate RNA and DNA motifs with a wide range of functions from large random sequence libraries. Once the primary sequence of a functional motif is known, the sequence space around it can be comprehensively explored using a combination of random mutagenesis and selection. However, methods to explore the sequence space of a secondary structure are not as well characterized. Read More

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Semi-supervised learning for an improved diagnosis of COVID-19 in CT images.

PLoS One 2021 1;16(4):e0249450. Epub 2021 Apr 1.

School of Electrical Engineering, Korea University, Seoul, Korea.

Coronavirus disease 2019 (COVID-19) has been spread out all over the world. Although a real-time reverse-transcription polymerase chain reaction (RT-PCR) test has been used as a primary diagnostic tool for COVID-19, the utility of CT based diagnostic tools have been suggested to improve the diagnostic accuracy and reliability. Herein we propose a semi-supervised deep neural network for an improved detection of COVID-19. Read More

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Effects of sheared chromatin length on ChIP-seq quality and sensitivity.

G3 (Bethesda) 2021 Mar 31. Epub 2021 Mar 31.

Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA.

Chromatin immunoprecipitation followed by massively parallel, high throughput sequencing (ChIP-seq) is the method of choice for genome-wide identification of DNA segments bound by specific transcription factors or in chromatin with particular histone modifications. However, the quality of ChIP-seq datasets varies widely, with a substantial fraction being of intermediate to poor quality. Thus, it is important to discern and control the factors that contribute to variation in ChIP-seq. Read More

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Uptake, Translocation, and Biotransformation of Neonicotinoid Imidaclothiz in Hydroponic Vegetables: Implications for Potential Intake Risks.

J Agric Food Chem 2021 Mar 31. Epub 2021 Mar 31.

Institute of Plant and Environment Protection, Beijing Academy of Agriculture and Forestry Sciences, Beijing 100097, P. R. China.

Imidaclothiz is a novel and systemic neonicotinoid pesticide with excellent insecticidal efficacy. However, knowledge of its uptake, translocation, and biotransformation within plants is still largely unknown, restricting work on its accurate and comprehensive risk assessment. Here, we systematically investigated the behavior of imidaclothiz in three plant-water systems via hydroponic experiments. Read More

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Removal of N,N-dimethylformamide by dielectric barrier discharge plasma combine with manganese activated carbon.

Environ Sci Pollut Res Int 2021 Mar 31. Epub 2021 Mar 31.

Wuhan Water Science Research Institute, Wuhan, 430014, China.

Manganese activated carbon (Mn-AC) was successfully prepared by the incipient wetness method and characterized by SEM, XRD, and FTIR. This study chose N,N-dimethylformamide (DMF) as the target pollutant, and the removal rate of DMF and removal mechanism were systematically studied by dielectric barrier discharge (DBD) plasma combined with Mn-AC. This study indicated that DBD plasma combined with Mn-AC could effectively remove DMF. Read More

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BAIT: A New Medical Decision Support Technology Based on Discrete Choice Theory.

Med Decis Making 2021 Mar 30:272989X211001320. Epub 2021 Mar 30.

Councyl, Delft, Netherlands.

We present a novel way to codify medical expertise and to make it available to support medical decision making. Our approach is based on econometric techniques (known as conjoint analysis or discrete choice theory) developed to analyze and forecast consumer or patient behavior; we reconceptualize these techniques and put them to use to generate an explainable, tractable decision support system for medical experts. The approach works as follows: using choice experiments containing systematically composed hypothetical choice scenarios, we collect a set of expert decisions. Read More

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Tactile temporal offset cues reduce visual representational momentum.

Atten Percept Psychophys 2021 Mar 29. Epub 2021 Mar 29.

Department of Experimental Psychology, University of Oxford, Oxford, UK.

The perception of dynamic objects is sometimes biased. For example, localizing a moving object after it has disappeared results in a perceptual shift in the direction of motion, a bias known as representational momentum. We investigated whether the temporal characteristics of an irrelevant, spatially uninformative vibrotactile stimulus bias the perceived location of a visual target. Read More

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