Virtual reality and motor imagery for early post-stroke rehabilitation.

BACKGROUND: Motor impairment is a common consequence of stroke causing difficulty in independent movement. The first month of post-stroke rehabilitation is the most effective period for recovery. Movement imagination, known as motor imagery, in combination with virtual reality may provide a way for stroke patients with severe motor disabilities to begin rehabilitation. METHODS: The aim of this study is to verify whether motor imagery and virtual reality help to activate stroke patients' motor cortex. 16 acute/subacute (< 6 months) stroke patients participated in this study. All participants performed motor imagery of basketball shooting which involved the following tasks: listening to audio instruction only, watching a basketball shooting animation in 3D with audio, and also performing motor imagery afterwards. Electroencephalogram (EEG) was recorded for analysis of motor-related features of the brain such as power spectral analysis in the [Formula: see text] and [Formula: see text] frequency bands and spectral entropy. 18 EEG channels over the motor cortex were used for all stroke patients. RESULTS: All results are normalised relative to all tasks for each participant. The power spectral densities peak near the [Formula: see text] band for all participants and also the [Formula: see text] band for some participants. Tasks with instructions during motor imagery generally show greater power spectral peaks. The p-values of the Wilcoxon signed-rank test for band power comparison from the 18 EEG channels between different pairs of tasks show a 0.01 significance of rejecting the band powers being the same for most tasks done by stroke subjects. The motor cortex of most stroke patients is more active when virtual reality is involved during motor imagery as indicated by their respective scalp maps of band power and spectral entropy. CONCLUSION: The resulting activation of stroke patient's motor cortices in this study reveals evidence that it is induced by imagination of movement and virtual reality supports motor imagery. The framework of the current study also provides an efficient way to investigate motor imagery and virtual reality during post-stroke rehabilitation.

The Effect of Swallowing Action Observation Therapy on Resting fMRI in Stroke Patients with Dysphagia.

Objective: Many stroke victims have severe swallowing problems. Previous neuroimaging studies have found that several brain regions scattered in the frontal, temporal, and parietal lobes, such as Brodmann's areas (BA) 6, 21, and 40, are associated with swallowing function. This study sought to investigate changes in swallowing function and resting-state functional magnetic resonance imaging (rs-fMRI) in stroke patients with dysphagia following action observation treatment. It also sought to detect changes in brain regions associated with swallowing in stroke patients. Methods: In this study, 12 healthy controls (HCs) and 12 stroke patients were recruited. Stroke patients were given 4 weeks of action observation therapy. In order to assess the differences in mfALFF values between patients before treatment and HCs, the fractional amplitude of low-frequency fluctuations (fALFF) in three frequency bands (conventional frequency band, slow-4, and slow-5) were calculated for fMRI data. The significant brain regions were selected as regions of interest (ROIs) for subsequent analysis. The mfALFF values were extracted from ROIs of the three groups (patients before and after treatment and HCs) and compared to assess the therapeutic efficacy. Results: In the conventional band, stroke patients before treatment had higher mfALFF in the inferior temporal gyrus and lower mfALFF in the calcarine fissure and surrounding cortex and thalamus compared to HCs. In the slow-4 band, there was no significant difference in related brain regions between stroke patients before treatment and HCs. In the slow-5 band, stroke patients before treatment had higher mfALFF in inferior cerebellum, inferior temporal gyrus, middle frontal gyrus, and lower mfALFF in calcarine fissure and surrounding cortex compared to HCs. We also assessed changes in aberrant brain activity that occurred both before and after action observation therapy. The mfALFF between stroke patients after therapy was closed to HCs in comparison to the patients before treatment. Conclusion: Action observation therapy can affect the excitability of certain brain regions. The changes in brain function brought about by this treatment may help to further understand the potential mechanism of network remodeling of swallowing function.

Contactless treatment for scoliosis by electromagnetically controlled shape-memory alloy rods: a preliminary study in rabbits.

PURPOSE: To evaluate the safety and efficacy of a system aiming to correct scoliosis called "electromagnetically controlled shape-memory alloy rods" (EC-SMAR) used in a rabbit model. METHODS: We heat-treated shape-memory alloy (SMA) rods to achieve a transition temperature between 34 and 47 °C and a C-shape austenite phase. We then developed a water-cooled generator capable of generating an alternating magnetic field (100 kHz) for induction heating. We next studied the efficacy of this system in vitro and determined some parameters prior to proceeding with animal experiments. We then employed a rabbit model, in which we fixed a straight rod along the spinous processes intraoperatively, and conducted induction heating postoperatively every 4 days for 1 month, while performing periodic X-ray assessments. RESULTS: Significant kyphotic deformations with Cobb angles of about 45° (p < 0.01) were created in five rabbits, and no complications occurred throughout the experiment. The rabbits are still very much alive and do not show any signs of discomfort. CONCLUSIONS: This is the first system that can modulate spinal deformation in a gradual, contactless, noninvasive manner through electromagnetic induction heating applied to SMA alloy rods. Although this study dealt with healthy spines, it provides promising evidence that this device also has the capacity to correct human kyphosis and even scoliosis in the future. These slides can be retrieved under Electronic Supplementary Material.

Additional effects of acupuncture on early comprehensive rehabilitation in patients with mild to moderate acute ischemic stroke: a multicenter randomized controlled trial.

BACKGROUND: Acupuncture is not considered a conventional therapy for post-stroke sequelae but it might have some additional positive effects on early rehabilitation. We conducted this trial to determine whether acupuncture has additional effects in early comprehensive rehabilitation for acute ischemic stroke and dysfunctions secondary to stroke. METHODS: Two hundred fifty patients were randomized into two groups: acupuncture (AG) or no acupuncture (NAG). Eighteen acupuncture treatment sessions were performed over a 3-week period. The primary outcome was blindly measured with National Institutes of Health Stroke Scale (NIHSS) at week 1, week 3, and week 7. Secondary outcomes included: Fugl-Meyer Assessment (FMA) for motor function, bedside swallowing assessment (BSA) and videofluoroscopic swallowing study (VFSS) for swallowing function, the Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA) for cognitive function, and the adverse reaction of acupuncture for safety assessment. RESULTS: Significant improvements from acupuncture treatment were observed in NIHSS (p < 0.001), VFSS (p < 0.001), MMSE (p < 0.001), MoCA (p = 0.001), but not obtained from FMA (p = 0.228). Changes from baseline of all above variables (except FMA) also had the same favorable results. A significant improvement in FMA lower extremity subscale appeared in AG (p = 0.020), but no significant difference was found for the upper extremity subscale (p = 0.707). More patients with swallowing disorder recovered in AG (p = 0.037). Low incidence of mild reaction of acupuncture indicated its safety. CONCLUSIONS: This trial showed acupuncture is safe and has additional multi-effect in improving neurologic deficits, swallowing disorder, cognitive impairment, and lower extremity function, but has no significant improvement for upper extremity function during this short-term study period. TRIAL REGISTRATION: Chictr.org ChiCTR-TRC -12001971 (March 2012).

A pilot study of post-total knee replacement gait rehabilitation using lower limbs robot-assisted training system.

The aim of this study was to explore the application value of the lower limbs robot-assisted training system for post-total knee replacement (TKR) gait rehabilitation. A total of 60 patients with osteoarthritis of the knee were equally randomized into the traditional and robot-assisted rehabilitation training groups within 1 week after TKR. All patients received 2-week training. Scores of hospital for special surgery (HSS), knee kinesthesia grades, knee proprioception grades, functional ambulation (FAC) scores, Berg balance scores, 10-m sitting-standing time, and 6-min walking distances were compared between the groups. The HSS score, Berg score, 10-m sitting-standing time, and 6-min walking distance of the robot-assisted training group were significantly higher than the control group (P < 0.05). Its knee kinesthesia grade, knee proprioception grade, and FAC score were better than the control group but not significantly (P > 0.05). Lower limbs robot-assisted rehabilitation training improves post-TKR patients' knee proprioception and stability more effectively compared with the traditional method. It improves patients' gait and symptoms, increases their walking speed, and prolongs their walking distances, which benefit their return to family and society.

Application of a Dual Upper Limb Task-Oriented Robotic System for the Functional Recovery of the Upper Limb in Stroke Patients.

Highly repetitive and task-oriented training has been shown to promote the recovery of limb function in stroke patients. Additionally, bilateral arm training can help stroke survivors regain their upper limb function and improve their daily activities. The dual upper limb task-oriented robotic system is designed to assist the healthy side of the stroke patient in driving the affected side to perform bilateral arm training through the use of a robotic device. It can also guide the patient in carrying out dual upper limb coordinated movements and engage them in a task-oriented virtual game using force feedback and human-computer interaction technology. This study aimed to assess the efficacy of the system in enhancing upper limb function and activities of daily living in stroke patients. The assessment methods used included motor evoked potential (MEP), functional test for the hemiplegic upper extremity-Hong Kong (FTHUE-HK), Fugl-Meyer Assessment Upper Extremity Scale (FMA-UE), and modified Barthel index (MBI). The results of the study indicate that the dual upper limb task-oriented robotic system can significantly improve the corticospinal pathway, upper limb function, and activities of daily living in stroke patients after 6 weeks of treatment. This system can serve as an effective adjunct to upper limb functional rehabilitation in stroke survivors, reducing the dependence on rehabilitation therapists. In conclusion, the dual upper limb task-oriented robotic system provides a new strategy for post-stroke limb functional rehabilitation and holds great potential for application, as it offers certain social and financial benefits.

Experimental Evidence for the Role of Dynamics in pH-Dependent Enzymatic Activity.

Enzymatic activity is heavily influenced by pH, but the rationale for the dynamical mechanism of pH-dependent enzymatic activity has not been fully understood. In this work, combined neutron scattering techniques, including quasielastic neutron scattering (QENS) and small angle neutron scattering (SANS), are used to study the structural and dynamic changes of a model enzyme, xylanase, under different pH and temperature environments. The QENS results reveal that xylanase at optimal pH exhibits faster relaxational dynamics and a lower energy barrier between conformational substates. The SANS results demonstrate that pH affects both xylanase's stability and monodispersity. Our findings indicate that enzymes have optimized stability and function under their optimal pH conditions, with both structure and dynamics being affected. The current study offers valuable insights into enzymatic functionality mechanisms, allowing for broad industrial applications.

Identification of ring current proton precipitation driven by scattering of electromagnetic ion cyclotron waves.

Among the most intense emissions in the Earth's magnetosphere, electromagnetic ion cyclotron (EMIC) waves are regarded as a critical candidate contributing to the precipitation losses of ring current protons, which however lacks direct multi-point observations to establish the underlying physical connection. Based upon a robust conjunction between the satellite pair of Van Allen Probe B and NOAA-19, we perform a detailed analysis to capture simultaneous enhancements of EMIC waves and ring current proton precipitation. By assuming that the ring current proton precipitation is mainly caused by EMIC wave scattering, we establish a physical model between the wave-driven proton diffusion and the ratio of precipitated-to-trapped proton count rates, which is subsequently applied to infer the intensity of EMIC waves required to cause the observed proton precipitation. Our simulations indicate that the model results of EMIC wave intensity, obtained using either the observed or empirical Gaussian wave frequency spectrum, are consistent with the wave observations, within a factor of 1.5. Our study therefore strongly supports the dominant contribution of EMIC waves to the ring current proton precipitation, and offers a valuable means to construct the global profile of EMIC wave intensity using low-altitude NOAA POES proton measurements, which generally have a broad L-shell coverage and high time resolution in favor of near-real-time conversion of the global EMIC wave distribution.

Effects of N and P addition on nutrient and stoichiometry of rhizosphere and non-rhizosphere soils of alfalfa in alkaline soil.

Nitrogen (N) and phosphorus (P) are important nutrients for plant growth and development. Soil alkalization is one of the main obstacles limiting the sustainable development of agriculture. Northern Ningxia is located in the arid and semi-arid region, with serious soil alkalinization. Alfalfa has the advantages of strong saline-alkali tolerance, high yield, high quality, and wide adaptability. It is an important forage for the comprehensive improvement and rational utilization of saline-alkali land and has great significance for solving land resource shortages, improving the ecological environment, and ensuring food security. It is important to study soil organic carbon (SOC), total N (TN), total P (TP), and stoichiometry of the rhizosphere and non-rhizosphere of alfalfa in alkaline soils. Therefore, N and P were added to the alkaline alfalfa field in the Yinchuan Plain of Hetao Basin in our experiment. Six treatments were set up, i.e., N-free (WN), medium N (MN) for 90 kg/hm2, high N (HN) for 180 kg/hm2, P-free (WP), medium P (MP) for 135 kg/hm2, and high P (HP) for 270 kg/hm2. The results are as follows: The N addition promotes SOC and TN but inhibits TP, and P addition promotes SOC and TP but inhibits TN of three soil layers. The N addition decreases C/N but increases C/P and N/P, while the P addition increases C/N but decreases C/P and N/P of three soil layers. The SOC, TN, TP, C/N, C/P, and N/P under HN and HP treatment reach the significance level (P < 0.05). Appropriate additions of N and P can improve rhizosphere and non-rhizosphere nutrients and stoichiometric structure, facilitating absorption and utilization by alfalfa and improve the production potential of alfalfa in alkaline soil.

Virtual reality-induced motor function of the upper extremity and brain activation in stroke: study protocol for a randomized controlled trial.

Background: The benefits of virtual reality (VR)-based rehabilitation were reported in patients after stroke, but there is insufficient evidence about how VR promotes brain activation in the central nervous system. Hence, we designed this study to explore the effects of VR-based intervention on upper extremity motor function and associated brain activation in stroke patients. Methods/design: In this single-center, randomized, parallel-group clinical trial with a blinded assessment of outcomes, a total of 78 stroke patients will be assigned randomly to either the VR group or the control group. All stroke patients who have upper extremity motor deficits will be tested with functional magnetic resonance imaging (fMRI), electroencephalography (EEG), and clinical evaluation. Clinical assessment and fMRI will be performed three times on each subject. The primary outcome is the change in performance on the Fugl-Meyer Assessment Upper Extremity Scale (FMA-UE). Secondary outcomes are functional independence measure (FIM), Barthel Index (BI), grip strength, and changes in the blood oxygenation level-dependent (BOLD) effect in the ipsilesional and contralesional primary motor cortex (M1) on the left and right hemispheres assessed with resting-state fMRI (rs-fMRI), task-state fMRI (ts-fMRI), and changes in EEG at the baseline and weeks 4 and 8. Discussion: This study aims to provide high-quality evidence for the relationship between upper extremity motor function and brain activation in stroke. In addition, this is the first multimodal neuroimaging study that explores the evidence for neuroplasticity and associated upper motor function recovery after VR in stroke patients. Clinical trial registration: Chinese Clinical Trial Registry, identifier: ChiCTR2200063425.

The effects of dynamic motion instability system training on motor function and balance after stroke: A randomized trial.

BACKGROUND: The balance and postural control of humans is related to the coordination of dynamic perception and movement. Multiple senses, such as vision, vestibular sense, proprioception, and/or a single sensory disorder, would lead to its integration disorder and induce imbalance and abnormal gait. OBJECTIVE: The present study aimed to determine the effects of dynamic motion instability system training (DMIST) on the balance and motor function of hemiplegic patients after stroke. METHODS: In this assessor-blinded, randomized controlled trial, the participants allocated to the intervention group (n = 20) received 30 minutes of conventional treatment and 20 minutes of DMIST training. Participants randomized to the control group (n = 20) received the same dose of conventional therapy and 20 minutes of general balance training. Rehabilitation was performed 5 times per week for 8 weeks. The primary outcome was the Fugl-Meyer assessment for the lower extremity (FMA-LE), and the secondary outcomes were the Berg balance scale (BBS) and gait function. Data were collected at baseline and immediately after the intervention. RESULTS: After 8 weeks (t1), both groups showed significant post-intervention improvements in BBS, FMA-LE, gait speed and stride length (P < 0.05); there were significant positive correlations between the increase in FMA-LE and gait speed and stride length. Compared with the control group, the DMIST group showed significant post-intervention improvements in FMA-LE, gait speed and stride length (P < 0.05). However, no significant differences between the groups were found over time with respect to BBS (P > 0.05). The experiences of patients with DMIST were positive, and no serious adverse events were related to the interventions. CONCLUSION: Supervised DMIST could be highly effective in treating lower-limb motor function in patients with stroke. Frequent (weekly) and medium-term (8 weeks) dynamic motion instability-guided interventions might be highly effective in enhancing motor function, and subsequently improving gait in stroke patients.

Aquatic strength training improves postural stability and walking function in stroke patients.

OBJECTIVE: This study aims to explore the effects of aquatic strength training on the postural balance and walking function of stroke patients. METHODS: A total of 56 chronic stroke patients more than 6 months post-stroke with walking and balance impairments were included in this study. After baseline evaluations, patients were randomly assigned to either the experiment group (n = 29) or control group (n = 27). Patients in the control group underwent conventional hydrotherapy, whereas patients in the experiment group received conventional hydrotherapy combined with aquatic lower extremity strength training. After six weeks of rehabilitation, all patients were evaluated by a blinded assessor, and the functional assessments including: Berg Balance Scale (BBS); Timed Up and Go Test (TUG and mTUG); 2 Minute Walk Test (2MWMT); and Gait analysis. RESULTS: There were no significant differences (P > .05) between the two groups in all evaluation indexes before rehabilitation. Six weeks after treatments, the results from both groups showed significant improvements compared with those in the baseline evaluations (P < .05). Notably, compared with the control group, BBS, TUG and mTUG, 2MWMT, and Gait analysis including stride length in the non-hemiplegic side, stride length, as well as walking speed and stride frequency in the hemiplegic side in experiment group were markedly improved (P < .05). CONCLUSION: Aquatic strength training can improve postural balance and lower extremity motor functions in chronic stroke patients.

Effects of Virtual Reality-Based Exercise on Balance in Patients With Stroke: A Systematic Review and Meta-analysis.

OBJECTIVE: The aim of the study is to quantify the effects of virtual reality-based exercise on balance after stroke. DESIGN: The PubMed, Embase, Cochrane Library, Cumulative Index of Nursing and Allied Health Literature, and Web of Science databases were searched until December 31, 2021. Independent investigators abstracted data, assessed the quality of the evidence, and rated the certainty of the evidence. The intergroup differences were determined by calculating mean difference and 95% confidence interval by RevMan 5.3 software. RESULTS: Fourteen randomized controlled trials involving 423 stroke patients were included. Patients who received virtual reality-based exercise illustrated marked improvements in the Berg Balance Scale (mean difference, 1.35; 95% confidence interval, 0.58 to 1.86; P < 0.00001; I2 = 44%), Timed Up and Go test (mean difference, -0.81; 95% confidence interval, -1.18 to -0.44; P < 0.0001; I2 = 0%), Functional Reach Test (mean difference, 3.06; 95% confidence interval, 1.31-4.80; P = 0.0006; I2 = 0%), 10-Meters Walking Test (mean difference, -1.53; 95% confidence interval, -2.92 to -0.13; P = 0.03; I2 = 33%), and Modified Barthel Index (mean difference, 5.26; 95% confidence interval, 1.70 to 8.82; P = 0.004; I2 = 0%) compared with the control group. CONCLUSIONS: Existing low-evidence analyses showed that virtual reality-based exercise could effectively and safely improve balance in chronic stroke. Longer-term virtual reality-based exercise was more effective on functional ability of stroke.

[Effects of rehabilitation robot for lower-limb on motor function in hemiplegic patients after stroke].

OBJECTIVE: To explore the effects of rehabilitation robot for lower-limb on motor function in hemiplegic patients after stroke. METHODS: Forty-eight hemiplegic patients were divided randomly into treatment (n = 24) and control (n = 24) group. The neuro-facilitation technique was applied for both groups. But the treatment group had also rehabilitation robot for lower-limb training of 10 - 20 min/d, 6 d/week for 8 weeks. All patients were assessed with the Fugl-Meyer lower limb (FMA), 10 m maximum walking speed (MWS), function ambulation category (FAC) classification and the modified Barthel index (MBI)at the time of beginning and 8 weeks later. RESULTS: Prior to intervention, no significant differences in any parameter existed between two groups. Eight weeks later, all assessment scores of FMA (25.7 ± 3.5), MWS (52 ± 16), FAC (4.3 ± 1.4) and MBI (82 + 17) were significantly better in the treatment group than those FMA (22.8 ± 3.7), MWS (40 ± 17), FAC (3.4 ± 1.3) and MBI (72 ± 14) in the control group. CONCLUSION: The application of rehabilitation robot for lower-limb may markedly improve the motor function of lower limb, walking ability and activity of daily living.

Error-Related Negativity-Based Robot-Assisted Stroke Rehabilitation System: Design and Proof-of-Concept.

Conventional rehabilitation systems typically execute a fixed set of programs that most motor-impaired stroke patients undergo. In these systems, the brain, which is embodied in the body, is often left out. Including the brains of stroke patients in the control loop of a rehabilitation system can be worthwhile as the system can be tailored to each participant and, thus, be more effective. Here, we propose a novel brain-computer interface (BCI)-based robot-assisted stroke rehabilitation system (RASRS), which takes inputs from the patient's intrinsic feedback mechanism to adapt the assistance level of the RASRS. The proposed system will utilize the patients' consciousness about their performance decoded through their error-related negativity signals. As a proof-of-concept, we experimented on 12 healthy people in which we recorded their electroencephalogram (EEG) signals while performing a standard rehabilitation exercise. We set the performance requirements beforehand and observed participants' neural responses when they failed/met the set requirements and found a statistically significant (p < 0.05) difference in their neural responses in the two conditions. The feasibility of the proposed BCI-based RASRS was demonstrated through a use-case description with a timing diagram and meeting the crucial requirements for developing the proposed rehabilitation system. The use of a patient's intrinsic feedback mechanism will have significant implications for the development of human-in-the-loop stroke rehabilitation systems.

Occupational Therapy Assessment for Upper Limb Rehabilitation: A Multisensor-Based Approach.

Most post-stroke patients experience varying degrees of impairment in upper limb function and fine motor skills. Occupational therapy (OT) with other rehabilitation trainings is beneficial in improving the strength and dexterity of the impaired upper limb. An accurate upper limb assessment should be conducted before prescribing upper limb OT programs. In this paper, we present a novel multisensor method for the assessment of upper limb movements that uses kinematics and physiological sensors to capture the movement of the limbs and the surface electromyogram (sEMG). These sensors are Kinect, inertial measurement unit (IMU), Xsens, and sEMG. The key assessment features of the proposed model are as follows: (1) classification of OT exercises into four classes, (2) evaluation of the quality and completion of the OT exercises, and (3) evaluation of the relationship between upper limb mobility and muscle strength in patients. According to experimental results, the overall accuracy for OT-based motion classification is 82.2%. In addition, the fusing of Kinect and Xsens data reveals that muscle strength is highly correlated with the data with a correlation coefficient (CC) of 0.88. As a result of this research, occupational therapy specialists will be able to provide early support discharge, which could alleviate the problem of the great stress that the healthcare system is experiencing today.

A comparison of machine learning classifiers for smartphone-based gait analysis.

This paper proposes a reliable monitoring scheme that can assist medical specialists in watching over the patient's condition. Although several technologies are traditionally used to acquire motion data of patients, the high costs as well as the large spaces they require make them difficult to be applied in a home context for rehabilitation. A reliable patient monitoring technique, which can automatically record and classify patient movements, is mandatory for a telemedicine protocol. In this paper, a comparison of several state-of-the-art machine learning classifiers is proposed, where stride data are collected by using a smartphone. The main goal is to identify a robust methodology able to assure a suited classification of gait movements, in order to allow the monitoring of patients in time as well as to discriminate among a pathological and physiological gait. Additionally, the advantages of smartphones of being compact, cost-effective and relatively easy to operate make these devices particularly suited for home-based rehabilitation programs. Graphical Abstract. This paper proposes a reliable monitoring scheme that can assist medical specialists in watching over the patient's condition. Although several technologies are traditionally used to acquire motion data of patients, the high costs as well as the large spaces they require make them difficult to be applied in a home context for rehabilitation. A reliable patient monitoring technique, which can automatically record and classify patient movements, is mandatory for a telemedicine protocol. In this paper, a comparison of several state-of-the-art machine learning classifiers is proposed, where stride data are collected and processed by using a smartphone(see figure). The main goal is to identify a robust methodology able to assure a suited classification of gait movements, in order to allow the monitoring of patients in time as well as to discriminate among a pathological and physiological gait. Additionally, the advantages of smartphones of being compact, cost-effective and relatively easy to operate make these devices particularly suited for home-based rehabilitation programs.

Investigations of structural and dynamical mechanisms of ice formation regulated by graphene oxide nanosheets.

Recent research indicates that graphene oxide (GO) nanosheets can be used to regulate ice formation by controlling critical ice nucleus growth in water at supercooling temperatures. In addition, the study of ice formation mechanisms regulated by GO nanosheets, a good model system for antifreeze proteins (AFPs), will shed light on how AFPs regulate ice formation in nature. In this work, time-resolved small-angle x-ray scattering (TR-SAXS) and quasi-elastic neutron scattering (QENS) experiments were carried out to investigate the structural and dynamical mechanisms of ice formation regulated by GO nanosheets. Strikingly, a transient intermediate state was observed in TR-SAXS experiments that only exists in the aqueous dispersions with a larger GO size (11 nm). This serves as evidence that the size of GO is critical for regulating ice formation. Elastic neutron scattering results indicate that ice is formed in all samples and thermal hysteresis occurs in GO aqueous dispersions in both H2O and D2O. The structural and dynamics information about water molecules in GO, extracted from QENS, reveals different dynamical behaviors of water molecules in GO aqueous dispersions when approaching the ice formation temperature.

Visual feedback therapy for restoration of upper limb function of stroke patients.

OBJECTIVE: To investigate the effects of mirror neuron theory-based visual feedback therapy (VFT) on restoration of upper limb function of stroke patients and motor-related cortical function using functional magnetic resonance imaging (fMRI). METHODS: Hemiplegic stroke patients were randomly divided into two groups: a VFT group and a control (CTL) group. Sixteen patients in the VFT group received conventional rehabilitation (CR) and VFT for 8 weeks, while 15 patients in the CTL group received only CR. The Barthel Index (BI) was used to assess the activities of daily living at baseline and the 8th week of the recovery training period. The Fugl-Meyer assessment (FMA) scale, somatosensory evoked potential (SEP), and fMRI were used to evaluate the recovery effect of the training therapies. The latencies and amplitudes of N9 and N20 were measured. Before recovery training, fMRI was performed for all patients in the VFT and CTL groups. In addition, 17 patients (9 in the VFT group and 8 in the CTL group) underwent fMRI for follow-up 2 months after treatment. Qualitative data were analyzed using the χ 2 test. The independent sample t-test was used to compare normally distributed data among different groups, the paired sample t-test was used to compare data between groups, and the non-parametric test was used to comparing data without normal distribution among groups. RESULTS: There were no significant differences between the VFT and CTL group in all indexes. However, after 8 weeks of recovery training, these indexes were all significantly improved (P < 0.05). As compared with the CTL group, the FMA scores, BI, and N9/N20 latencies and amplitudes of SEP in the VFT group were significantly improved (P < 0.05). Two months after recovery training, fMRI showed that the degree of activation of the bilateral central anterior gyrus, parietal lobe, and auxiliary motor areas was significantly higher in the VFT group than the CTL group (P < 0.05). CONCLUSIONS: VFT based on mirror neuron theory is an effective approach to improve upper extremity motor function and daily activity performance of stroke patients. The therapeutic mechanism promotes motor relearning by activating the mirror neuron system and motor cortex. SEP amplitudes increased only for patients who participated in visual feedback. VFT promotes sensory-motor plasticity and behavioral changes in both the motor and sensory domains.

An Efficient Deep Learning Based Method for Speech Assessment of Mandarin-Speaking Aphasic Patients.

Speech assessment is an important part of the rehabilitation process for patients with aphasia (PWA). Mandarin speech lucidity features such as articulation, fluency, and tone influence the meaning of the spoken utterance and overall speech clarity. Automatic assessment of these features is important for an efficient assessment of the aphasic speech. Hence, in this paper, a standardized automatic speech lucidity assessment method for Mandarin-speaking aphasic patients using a machine learning based technique is presented. The proposed assessment method adopts the Chinese Rehabilitation Research Center Aphasia Examination (CRRCAE) standard as a guideline. Quadrature based high-resolution time-frequency images with a convolutional neural network (CNN) are utilized to develop a method that can map the relationship between the severity level of aphasic patients' speech and the three speech lucidity features. The results show a linear relationship with statistically significant correlations between the normalized true-class output activations (TCOA) of the CNN model and patients' articulation, fluency, and tone scores, i.e., 0.71 (p < 0.001), 0.60 (p < 0.001) and 0.58 (p < 0.001), respectively. The linearity of the proposed Mandarin aphasic speech assessment method and its significant correlation with the speech severity levels show the efficacy of the method in predicting the severity of impaired Mandarin speech. The outcome of this research envisages assisting speech-language pathologists in Mandarin-speech impairment assessment and promoting early support discharge; hence could alleviate the stress that the healthcare system is currently experiencing in China nationwide. The framework of the proposed Mandarin aphasic speech assessment method can be readily extended to other languages.