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Transcranial magnetic stimulation entrains alpha oscillatory activity in occipital cortex.

Sci Rep 2021 Sep 17;11(1):18562. Epub 2021 Sep 17.

Department of Psychology, New York University, New York, NY, 10003, USA.

Parieto-occipital alpha rhythms (8-12 Hz) underlie cortical excitability and influence visual performance. Whether the synchrony of intrinsic alpha rhythms in the occipital cortex can be entrained by transcranial magnetic stimulation (TMS) is an open question. We applied 4-pulse, 10-Hz rhythmic TMS to entrain intrinsic alpha oscillators targeting right V1/V2, and tested four predictions with concurrent electroencephalogram (EEG): (1) progressive enhancement of entrainment across time windows, (2) output frequency specificity, (3) dependence on the intrinsic oscillation phase, and (4) input frequency specificity to individual alpha frequency (IAF) in the neural signatures. Read More

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September 2021

Reinterpreting the human ABR binaural interaction component: isolating attention from stimulus effects.

Hear Res 2021 Sep 4;410:108350. Epub 2021 Sep 4.

Faculty of Information Technology and Communication Sciences, Tampere University, 33720 Tampere, Finland.

Subtracting the sum of left and right monaural auditory brainstem responses (ABRs) from the corresponding binaural ABR isolates the binaural interaction component (ABR-BIC). In a previous investigation (Ikeda, 2015), during auditory yet not visual tasks, tone-pips elicited a significant difference in amplitude between summed monaural and binaural ABRs. With click stimulation, this amplitude difference was task-independent. Read More

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September 2021

Towards a unifying basis of auditory thresholds: Thresholds for multicomponent stimuli.

Hear Res 2021 Sep 4;410:108349. Epub 2021 Sep 4.

Research Group Comparative Neuroscience, Leibniz Institute for Neurobiology, Magdeburg, Germany.

Sounds consisting of multiple simultaneous or consecutive components can be detected by listeners when the stimulus levels of the components are lower than those needed to detect the individual components alone. The mechanisms underlying such spectral, spectrotemporal, temporal, or across-ear integration are not completely understood. Here, we report threshold measurements from human subjects for multicomponent stimuli (tone complexes, tone sequences, diotic or dichotic tones) and for their individual sinusoidal components in quiet. Read More

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September 2021

Phase and power modulations on the amplitude of TMS-induced motor evoked potentials.

PLoS One 2021 16;16(9):e0255815. Epub 2021 Sep 16.

Section Brain Stimulation and Cognition, Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands.

The evaluation of transcranial magnetic stimulation (TMS)-induced motor evoked potentials (MEPs) promises valuable information about fundamental brain related mechanisms and may serve as a diagnostic tool for clinical monitoring of therapeutic progress or surgery procedures. However, reports about spontaneous fluctuations of MEP amplitudes causing high intra-individual variability have led to increased concerns about the reliability of this measure. One possible cause for high variability of MEPs could be neuronal oscillatory activity, which reflects fluctuations of membrane potentials that systematically increase and decrease the excitability of neuronal networks. Read More

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September 2021

Comparison Between Conventional Flash and Off-Response Intraoperative Visual Evoked Potential Monitoring for Endoscopic Endonasal Surgery.

Oper Neurosurg (Hagerstown) 2021 Sep 15. Epub 2021 Sep 15.

Department of Neurosurgery, Shinshu University School of Medicine, Matsumoto, Japan.

Background: Intraoperative flash stimulation visual evoked potential (VEP) monitoring has been used for endoscopic endonasal approach (EEA). Recently, off-response VEP, which is recorded when the light stimulus is turned off, was introduced to monitor visual function intraoperatively.

Objective: To evaluate off-response VEP monitoring in comparison with the conventional flash stimulation VEP monitoring for EEA. Read More

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September 2021

Applications of optimal nonlinear control to a whole-brain network of FitzHugh-Nagumo oscillators.

Phys Rev E 2021 Aug;104(2-1):024213

Institut für Softwaretechnik und Theoretische Informatik, Technische Universität Berlin, Marchstraße 23, 10587 Berlin, Germany.

We apply the framework of optimal nonlinear control to steer the dynamics of a whole-brain network of FitzHugh-Nagumo oscillators. Its nodes correspond to the cortical areas of an atlas-based segmentation of the human cerebral cortex, and the internode coupling strengths are derived from diffusion tensor imaging data of the connectome of the human brain. Nodes are coupled using an additive scheme without delays and are driven by background inputs with fixed mean and additive Gaussian noise. Read More

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Relationship Between Anesthesia Depth and Quality of Seizures in Patients Undergoing Electroconvulsive Therapy: A Prospective Observational Study.

J ECT 2021 Sep 13. Epub 2021 Sep 13.

From the Departments of Anesthesiology and Intensive Care Medicine Psychiatry, Psychotherapy and Psychosomatics, Medical University of Innsbruck, Innsbruck, Austria.

Objectives: Electroconvulsive therapy under general anesthesia is an established treatment for mood disorders, such as therapy-resistant depression. As most anesthetic drugs used for induction of anesthesia increase the seizure threshold, adequate depth of anesthesia without diminishing the therapeutic efficacy of interventions is crucial. The aim of this study was to investigate whether anesthesia depth as assessed by Narcotrend (NCT) monitoring correlates with maximum seizure quality. Read More

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September 2021

Evidence for tetrodotoxin-resistant spontaneous myogenic contractions of mouse isolated stomach that are dependent on acetylcholine.

Br J Pharmacol 2021 Sep 14. Epub 2021 Sep 14.

Blizard Institute and the National Centre for Bowel Research, Barts The London School of Medicine and Dentistry, Queen Mary University of London, London, UK.

Background And Purpose: Gastric pacemaker cells (interstitial cells of Cajal; ICC) are believed to initiate myogenic (non-neuronal) contractions. These become damaged in gastroparesis, associated with dysrhythmic electrical activity and nausea. We utilised mouse isolated stomach to model myogenic contractions, investigate their origin and actions of ICC modulators. Read More

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September 2021

Combination of Matching Responsive Stimulations of Hippocampus and Subiculum for Effective Seizure Suppression in Temporal Lobe Epilepsy.

Front Neurol 2021 26;12:638795. Epub 2021 Aug 26.

Qiushi Academy for Advanced Studies, Zhejiang University, Hangzhou, China.

Responsive neural stimulation (RNS) is considered a promising neural modulation therapy for refractory epilepsy. Combined stimulation on different targets may hold great promise for improving the efficacy of seizure control since neural activity changed dynamically within associated brain targets in the epileptic network. Three major issues need to be further explored to achieve better efficacy of combined stimulation: (1) which nodes within the epileptogenic network should be chosen as stimulation targets? (2) What stimulus frequency should be delivered to different targets? and (3) Could the efficacy of RNS for seizure control be optimized by combined different stimulation targets together? In our current study, Granger causality (GC) method was applied to analyze epileptogenic networks for finding key targets of RNS. Read More

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Acute Detubulation of Ventricular Myocytes Amplifies the Inhibitory Effect of Cholinergic Agonist on Intracellular Ca Transients.

Front Physiol 2021 26;12:725798. Epub 2021 Aug 26.

Department of Physiology and Cell Biology, The Ohio State University, Columbus, OH, United States.

Muscarinic receptors expressed in cardiac myocytes play a critical role in the regulation of heart function by the parasympathetic nervous system. How the structural organization of cardiac myocytes affects the regulation of Ca handling by muscarinic receptors is not well-defined. Using confocal Ca imaging, patch-clamp techniques, and immunocytochemistry, the relationship between t-tubule density and cholinergic regulation of intracellular Ca in normal murine ventricular myocytes and myocytes with acute disruption of the t-tubule system caused by formamide treatment was studied. Read More

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Tongue acceleration in humans evoked with intramuscular electrical stimulation of genioglossus.

Respir Physiol Neurobiol 2021 Sep 8:103786. Epub 2021 Sep 8.

Neuroscience Research Australia, Barker St, Randwick, NSW, Australia; University of New South Wales, Sydney, NSW, Australia. Electronic address:

Genioglossus was stimulated intramuscularly to determine the effect of regional activation of the muscle on tongue movement in eight healthy adults. Stimulation at motor threshold was delivered with a needle electrode inserted to different depths in the anterior and posterior regions of genioglossus. The current amplitude that induced muscle contraction was ∼80% higher for anterior than posterior sites. Read More

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September 2021

Real-time estimation of phase and amplitude with application to neural data.

Sci Rep 2021 Sep 10;11(1):18037. Epub 2021 Sep 10.

Movement Disorders and Neuromodulation Unit, Department of Neurology, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Germany.

Computation of the instantaneous phase and amplitude via the Hilbert Transform is a powerful tool of data analysis. This approach finds many applications in various science and engineering branches but is not proper for causal estimation because it requires knowledge of the signal's past and future. However, several problems require real-time estimation of phase and amplitude; an illustrative example is phase-locked or amplitude-dependent stimulation in neuroscience. Read More

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September 2021

CHIR99021 Promotes hiPSC-Derived Cardiomyocyte Proliferation in Engineered 3D Microtissues.

Adv Healthc Mater 2021 Sep 9:e2100926. Epub 2021 Sep 9.

Experimental Renal and Cardiovascular Research, Department of Nephropathology, Institute of Pathology, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Muscle Research Center Erlangen (MURCE), Erlangen, 91054, Germany.

Cardiac tissue engineering is a promising strategy to generate human cardiac tissues for modeling cardiac diseases, screening for therapeutic drugs, and repairing the injured heart. Yet, several issues remain to be resolved including the generation of tissues with high cardiomyocyte density. Here, it is shown that the integration of the glycogen synthase kinase-3β inhibitor CHIR99021 in collagen I hydrogels promotes proliferation of human-induced pluripotent stem cell-derived (hiPSC) cardiomyocytes post-fabrication improving contractility of and calcium flow in engineered 3D cardiac microtissues. Read More

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September 2021

Changes in Cortical Excitability and Parkinson Tremor After Botulinum Toxin Therapy.

Neurology 2021 Sep 8. Epub 2021 Sep 8.

London Health Sciences Centre - Lawson Health Research Institute, Department of Clinical Neurological Sciences, London, ON, Canada.

Objectives: This study investigated the relationship between botulinum toxin type A (BoNT-A) administration, tremor amplitude, and modulation of intracortical excitability and sensorimotor processing using paired-pulse transcranial magnetic stimulation (pp-TMS) in early, tremor-dominant Parkinson's disease (PD) patients.

Methods: Twelve "De-novo" (naïve to anti-PD medications) and seven "L-dopa" (optimized on levodopa) PD participants with tremor affecting one arm were recruited. All participants received 4 serial BoNT-A treatments for tremor every 12-weeks and peak effect was assessed 6-weeks post-treatment, totaling 8 visits over 42-weeks. Read More

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September 2021

Vibration decreases the responsiveness of Ia afferents and spinal motoneurons in humans.

J Neurophysiol 2021 09 8. Epub 2021 Sep 8.

Department of Anatomy and Structural Science, School of Medicine, Yamagata University, Yamagata, Japan.

Following vibration, Hoffmann reflex (H-reflex) amplitude is depressed; however, the mechanisms underlying these phenomena remain unknown. This study investigated the influence of frequency and duration of vibration on the H-reflex amplitude, heteronymous facilitation of the tendon jerk (T-wave) mediated by group Ia afferents, and cervicomedullary motor evoked potential (CMEP) amplitude in 18 healthy human subjects. The H-reflex of the flexor carpi radialis (FCR) was induced by median nerve stimulation at the elbow, and the conditioning FCR stimulation enhanced the T-wave of the biceps brachii (BB). Read More

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September 2021

Effect of posture and body weight loading on spinal posterior root reflex responses.

Eur J Neurosci 2021 Sep 8. Epub 2021 Sep 8.

Toledo Physiotherapy Research Group (GIFTO), Faculty of Physiotherapy and Nursing, Castilla La Mancha University, Toledo, Spain.

The posterior root muscle response (PRM) is a monosynaptic reflex that is evoked by single pulse transcutaneous spinal cord stimulation (tSCS). The main aim of this work was to analyse how body weight loading influences PRM reflex threshold measured from several lower limb muscles in healthy participants. PRM reflex responses were evoked with 1ms rectangular monophasic pulses applied at an interval of 6 s via a self-adhesive electrode (9x5 cm) at the T11-T12 vertebral level. Read More

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September 2021

Waveform feature extraction and signal recovery in single-channel TVEP based on Fitzhugh-Nagumo stochastic resonance.

J Neural Eng 2021 Sep 17;18(5). Epub 2021 Sep 17.

School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China.

. Transient visual evoked potential (TVEP) can reflect the condition of the visual pathway and has been widely used in brain-computer interface. TVEP signals are typically obtained by averaging the time-locked brain responses across dozens or even hundreds of stimulations, in order to remove different kinds of interferences. Read More

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September 2021

Fatigability of the knee extensor muscles during high-load fast and low-load slow resistance exercise in young and older adults.

Exp Gerontol 2021 Sep 5;154:111546. Epub 2021 Sep 5.

Exercise Science Program, Department of Physical Therapy, Marquette University, Milwaukee, WI, USA; Athletic and Human Performance Research Center, Marquette University, Milwaukee, WI, USA. Electronic address:

Resistance exercise training is a cornerstone in preventing age-related declines in muscle mass and strength, and fatigability of limb muscle is important to this adaptive response. It is unknown, however, whether fatigability and the underlying mechanisms differ between different resistance exercise protocols in young and older adults. The purpose of this study was to quantify the fatigability of the knee extensors and identify the mechanisms in 20 young (22. Read More

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September 2021

The Effect of Sound and Stimulus Expectation on Transcranial Magnetic Stimulation-Elicited Motor Evoked Potentials.

Brain Topogr 2021 Sep 6. Epub 2021 Sep 6.

School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, UK.

The amplitude of motor-evoked potentials (MEPs) elicited by transcranial magnetic stimulation (TMS) over the motor cortex is influenced by multiple factors. TMS delivery is accompanied by an abrupt clicking noise which can induce a startle response. This study investigated how masking/attenuating the sound produced by the TMS system discharging influences MEP amplitudes. Read More

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September 2021

Stabilizing breathing pattern using local mechanical vibrations: comparison of deterministic and stochastic stimulations in rodent models of apnea of prematurity.

Biomed Eng Lett 2021 Sep 1:1-10. Epub 2021 Sep 1.

Department of Biomedical Engineering, Boston University, 44 Cummington Mall, Boston, MA 02215 USA.

Mechanical stimulation has been shown to reduce apnea of prematurity (AOP), a major concern in preterm infants. Previous work suggested that the underlying mechanism is stochastic resonance, amplification of a subthreshold signal by stochastic stimulation. We hypothesized that the mechanism behind the reduction of apnea length may not be a solely stochastic phenomenon, and suggest that a purely deterministic, non-random mechanical stimulation could be equally as effective. Read More

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September 2021

Essential tremor amplitude modulation by median nerve stimulation.

Sci Rep 2021 Sep 6;11(1):17720. Epub 2021 Sep 6.

Medical Research Council Brain Network Dynamics Unit, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, OX1 3TH, UK.

Essential tremor is a common neurological disorder, characterised by involuntary shaking of a limb. Patients are usually treated using medications which have limited effects on tremor and may cause side-effects. Surgical therapies are effective in reducing essential tremor, however, the invasive nature of these therapies together with the high cost, greatly limit the number of patients benefiting from them. Read More

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September 2021

Pain expectation and avoidance in the social context: an electrophysiological study.

J Physiol Sci 2021 Sep 6;71(1):29. Epub 2021 Sep 6.

Department of Neuroscience "Rita Levi Montalcini", University of Turin, 10125, Turin, TO, Italy.

Contingent negative variation (CNV) is an informative electrophysiological measure of pain anticipation showing higher amplitudes when highly painful stimulation is expected while presenting lower amplitudes when low painful stimulation is expected. Two groups of participants were recruited: one group expected and received an electrical stimulation of different intensities while being alone in the room (i.e. Read More

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September 2021

Low pressure voiding induced by stimulation and 1 kHz post-stimulation block of the Pudendal nerves in cats.

Exp Neurol 2021 Sep 3:113860. Epub 2021 Sep 3.

Department of Urology, University of Pittsburgh, Pittsburgh, PA, USA; Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA, USA; Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA. Electronic address:

The goal of this study is to induce low-pressure voiding by stimulation and bilateral 1 kHz post-stimulation block of the pudendal nerves. In anesthetized cats, wire hook electrodes were placed on the left and/or right pudendal nerves. Stimulus pulses (30 Hz, 0. Read More

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September 2021

Regulation of Dual Specificity Phosphatases by Fibroblast Growth Factor signaling pathways in bovine granulosa cells.

Reproduction 2021 Sep 1. Epub 2021 Sep 1.

C Price, CRRA, University of Montreal, St-Hyacinthe, Canada.

Controling the duration and amplitude of mitogen activated protein kinase (MAPK) signaling is an important element in deciding cell fate. One group of intracellular negative regulators of MAPK activity is a subfamily of the dual specificity phosphatase (DUSP) superfamily, of which up to 16 members have been described in ovarian granulosa cells. Growth factors stimulate proliferation of granulosa cells through MAPK, PKC and AKT pathways, although it is not known which pathways control DUSP expression in these cells. Read More

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September 2021

Botulinum toxin in the masseter muscle: Lingering effects of denervation.

Anat Rec (Hoboken) 2021 Sep 5. Epub 2021 Sep 5.

Department of Orthodontics, University of Washington, Seattle, Washington, USA.

Botulinum neurotoxins (BoNTs) are paralytic agents used to treat a variety of conditions in jaw muscles. Although their effect is considered temporary, there are reports of persistent functional changes. Using rabbits that received BoNT injection in one masseter muscle, the recovery of neuromuscular connection was investigated using nerve stimulation to evoke an electromyographic (EMG) response, and the recovery of muscle fibers was investigated using histological morphometry and bromodeoxyuridine (BrdU) immunohistochemistry. Read More

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September 2021

Using Fractional Amplitude of Low-Frequency Fluctuations and Functional Connectivity in Patients With Post-stroke Cognitive Impairment for a Simulated Stimulation Program.

Front Aging Neurosci 2021 13;13:724267. Epub 2021 Aug 13.

Department of Rehabilitation Medicine, Zhongnan Hospital of Wuhan University, Wuhan, China.

Stroke causes alterations in local spontaneous neuronal activity and related networks functional connectivity. We hypothesized that these changes occur in patients with post-stroke cognitive impairment (PSCI). Fractional amplitude of low-frequency fluctuations (fALFF) was calculated in 36 patients with cognitive impairment, including 16 patients with hemorrhagic stroke (hPSCI group), 20 patients with ischemic stroke (iPSCI group). Read More

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Age-Related Differences in Corticospinal Excitability and Anticipatory Postural Adjustments of the Trunk.

Front Aging Neurosci 2021 17;13:718784. Epub 2021 Aug 17.

School of Sport, Exercise, and Rehabilitation Sciences, University of Birmingham, Birmingham, United Kingdom.

Anticipatory postural adjustments (APAs) are a feedforward mechanism for the maintenance of postural stability and are delayed in old adults. We previously showed in young adults that APAs of the trunk induced by a fast shoulder movement were mediated, at least in part, by a cortical mechanism. However, it remains unclear the relationship between delayed APAs and motor cortical excitability in ageing. Read More

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Optoacoustically induced auditory brainstem responses in the mouse model enhanced through an absorbing film.

J Biomed Opt 2021 Sep;26(9)

Univ. des Saarlandes, Germany.

Significance: Optoacoustic stimulation offers an alternative stimulation strategy for the hearing organ. To serve as the base for a novel auditory prosthesis, the optoacoustic stimulation must be biocompatible and energy-saving.

Aim: Enhancing the efficiency of optoacoustic stimulation while reducing the energy input in a suited animal model. Read More

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September 2021

Impaired Hippocampal Neurovascular Coupling in a Mouse Model of Alzheimer's Disease.

Front Physiol 2021 12;12:715446. Epub 2021 Aug 12.

Department of Pharmacology and Physiology, Faculty of Medicine, Université de Montréal, Montréal, QC, Canada.

Alzheimer's disease (AD), the most common form of dementia, is characterized by neuronal degeneration and cerebrovascular dysfunction. Increasing evidence indicates that cerebrovascular dysfunction may be a key or an aggravating pathogenic factor in AD. This emphasizes the importance to investigate the tight coupling between neuronal activity and cerebral blood flow (CBF) termed neurovascular coupling (NVC). Read More

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Ocular direct current stimulation affects retinal ganglion cells.

Sci Rep 2021 Sep 2;11(1):17573. Epub 2021 Sep 2.

Institute for Biomedical Engineering and Informatics, Technische Universität Ilmenau, Ilmenau, Germany.

Ocular current stimulation (oCS) with weak current intensities (a few mA) has shown positive effects on retinal nerve cells, which indicates that neurodegenerative ocular diseases could be treated with current stimulation of the eye. During oCS, a significant polarity-independent reduction in the characteristic P50 amplitude of a pattern-reversal electroretinogram was found, while no current stimulation effect was found for a full field electroretinogram (ffERG). The ffERG data indicated a trend for a polarity-dependent influence during oCS on the photopic negative response (PhNR) wave, which represents the sum activity of the retinal ganglion cells. Read More

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September 2021