Functional near-infrared spectroscopy in non-invasive neuromodulation

Non-invasive cerebral neuromodulation technologies are essential for the reorganization of cerebral neural networks,which have been widely applied in the field of central neurological diseases,such as stroke,Parkinson’s disease,and mental disorders.Although significant advances have been made in neuromodulation technologies,the identification of optimal neurostimulation paramete rs including the co rtical target,duration,and inhibition or excitation pattern is still limited due to the lack of guidance for neural circuits.Moreove r,the neural mechanism unde rlying neuromodulation for improved behavioral performance remains poorly understood.Recently,advancements in neuroimaging have provided insight into neuromodulation techniques.Functional near-infrared spectroscopy,as a novel non-invasive optical brain imaging method,can detect brain activity by measuring cerebral hemodynamics with the advantages of portability,high motion tole rance,and anti-electromagnetic interference.Coupling functional near-infra red spectroscopy with neuromodulation technologies offe rs an opportunity to monitor the cortical response,provide realtime feedbac k,and establish a closed-loop strategy integrating evaluation,feedbac k,and intervention for neurostimulation,which provides a theoretical basis for development of individualized precise neuro rehabilitation.We aimed to summarize the advantages of functional near-infra red spectroscopy and provide an ove rview of the current research on functional near-infrared spectroscopy in transcranial magnetic stimulation,transcranial electrical stimulation,neurofeedback,and braincomputer interfaces.Furthermore,the future perspectives and directions for the application of functional near-infrared spectroscopy in neuromodulation are summarized.In conclusion,functional near-infrared spectroscopy combined with neuromodulation may promote the optimization of central pellral reorganization to achieve better functional recovery form central nervous system diseases.

Biomass-based N doped carbon as metal-free catalyst for selective oxidation of D-xylose into D-xylonic acid

Rational design and facile preparation of low-cost and efficient catalysts for the selective converting of biomass-derived monosaccharides into high value-added chemicals is highly demanded,yet challenging.Herein,we first demonstrate a N doped defect-rich carbon(NC-800-5)as metal-free catalyst for the selective oxidation of D-xylose into D-xylonic acid in alkaline aqueous solution at 100℃ for 30 min,with 57.4%yield.The doped graphitic N is found to be the active site and hydroxyl ion participating in the oxidation of D-xylose.Hydroxyl ion and D-xylose first adsorb on NC-800-5 surface,and the aldehyde group of D-xylose is catalyzed to form germinal diols ion.Then,C–H bond break to yield carboxylic group.Furthermore,NC-800-5 catalyst shows high stability in recycled test.

Base-free selective oxidation of monosaccharide into sugar acid by surface-functionalized carbon nanotube composites

Selective oxidation of biomass-derived monosaccharide into high value-added chemicals is highly desirable from sustainability perspectives.Herein,we demonstrate a surface-functionalized carbon nanotubesupported gold(Au/CNT-O and Au/CNT-N)catalyst for base-free oxidation of monosaccharide into sugar acid.Au/CNT-O and Au/CNT-N surfaces successfully introduced oxygen-and nitrogen-containing functional groups,respectively.The highest yields of gluconic acid and xylonic acid were 93.3%and 94.3%,respectively,using Au/CNT-N at 90℃ for 240 min,which is higher than that of using Au/CNT-O.The rate constants for monosaccharide decomposition and sugar acid formation in Au/CNT-N system were higher,while the corresponding activation energy was lower than in Au/CNT-O system.DFT calculation revealed that the mechanism of glucose oxidation to gluconic acid involves the adsorption and activation of O_(2),adsorption of glucose,dissociation of the formyl C-H bond and formation of O-H bond,and formation and desorption of gluconic acid.The activation energy barrier for the glucose oxidation over Au/CNT-N is lower than that of Au/CNT-O.The nitrogen-containing functional groups are more beneficial for accelerating monosaccharide oxidation and enhancing sugar acid selectivity than oxygen-containing functional groups.This work presents a useful guidance for designing and developing highly active catalysts for producing high-value-added chemicals from biomass.

Management of post-stroke depression(PSD)by electroencephalography for effective rehabilitation

Post-stroke depression(PSD)has negative impacts on the daily life of stroke survivors and delays their neuro-logical recovery.However,traditional post-stroke rehabilitation mainly focused on motor restoration,whereas little attention was given to the affective deficits.Effective management of PSD,including diagnosis,intervention,and follow-ups,is essential for post-stroke rehabilitation.As an objective measurement of the nervous system,electroencephalography(EEG)has been applied to the diagnosis and evaluation of PSD.In this paper,we re-viewed the literature most related to the clinical applications of EEG for PSD and offered a cross-section that is useful for selecting appropriate approaches in practice.This study aimed to gather EEG-based empirical ev-idence for PSD diagnosis,review interventions for managing PSD,and analyze the evaluation approaches.In total,33 diagnostic studies and 19 intervention studies related to PSD and depression were selected from the literature.It was found that the EEG features analyzed by both band-based and nonlinear dynamic approaches were capable of quantifying the abnormal neural responses on the cortical level for PSD diagnosis and interven-tion evaluation/prediction.Meanwhile,EEG-based machine learning has also been applied to the diagnosis and evaluation of depression to automate and speed up the process,and the results have been promising.Although brain-computer interface(BCI)interventions have been widely applied to post-stroke motor rehabilitation and cognitive training,BCI emotional training has not been directly used in PSD yet.This review showed the need for understanding the cortical responses of PSD to improve its diagnosis and precision treatment.It also revealed that future post-stroke rehabilitation plans should include training sessions for motor,affect,and cognitive functions and closely monitor their improvements.

Design of a virtual reality rehabilitation system for upper limbs that inhibits compensatory movement

Stroke is currently the main cause of death and disability among the elderly in our country.According to medical research,a considerable number of patients with physical disabilities can be recovered through rehabilitation training.However,traditional motor rehabilitation is a continuous,repeated and slow process,and patients tend to feel bored and lose motivation for training.In this paper,we developed a virtual reality rehabilitation system based on Kinect,which is a vision capture sensor,for patients with movement disorders who are at or above Brunnstrom Stage III and have certain motor ability.Through the management platform of the system,physician can obtain the patient's personal information,formulate and adjust the training plan.Patients can control the role in the virtual scene through Kinect sensor,and complete the training action according to the guidance.The system collects the user's motion data in real time and detect the compensation.The system will adaptively evolve to guide the patient to self-correct the compensatory patterns.After the training,the system will evaluate the patients based on the their training performance.Two experiments are also carried out to verify the accuracy of the range of motion and the effectiveness of virtual guidance.It is proved that the virtual reality upper limb rehabilitation training system studied in this paper is reliable,stable,and can guide users to complete the training action and improve the rehabilitation effect.

A review on functional near-infrared spectroscopy and application in stroke rehabilitation

Functional near-infrared spectroscopy(fNIRS)has gained great interest as a noninvasive modality to study the changes in cerebral hemodynamics related to brain activity.The unique and beneficial characteristics of fNIRS allow ecologically effective investigations of all ages and conditions in more realistic and clinical environments.In this review,we provide a comprehensive description of fNIRS basics,analytical method developments and applications in stroke rehabilitation.We first review various new methods for the time-series processing and functional analysis of fNIRS data.Then,we review the fNIRS-based application in clinical research for stroke rehabilitation and highlight the exciting developments based on fNIRS.Finally,we discuss the possible technical limitations of the implementation of fNIRS and provide suggestions from different aspects for practical application.

Effects of acupuncture on the relationship between cerebral hemodynamics and arterial blood pressure in patients with hypertension

The present study aimed to investigate the effect of an auricular acupuncture intervention on the relationship between changes in oxyhemoglobin concentration(Δ[O2Hb])and arterial blood pressure(ABP).The cerebral oxygenation signals in the bilateral prefrontal cortex(PFC),sensorimotor cortex(SMC),and temporal lobe cortex(TLC)of 15 patients with hypertension were measured by a 24-channel functional near-infrared spectroscopy(fNIRS)device before(State_R)and after(State_AT)the auricular acupuncture intervention.Coupling strength was used to quantitatively evaluate the strength of the couplings between ABP andΔ[O2Hb]in low-frequency oscillations(LF,0.07–0.2 Hz)and very-low-frequency oscillations(VLF,0.02–0.07 Hz).Results showed that the changes in wavelet amplitudes in the LF and VLF intervals did not exhibit significant differences after auricular acupuncture.The coupling strength from ABP toΔ[O2Hb]was significantly lower in the LF range after auricular acupuncture in the bilateral PFC,SMC,and TLC(p<0.0083).Additionally,the coupling strength from ABP toΔ[O2Hb]in the VLF range was significantly lower in the bilateral PFC in State_AT than in State_R(p<0.0083).These results indicated that fNIRS together with ABP can effectively evaluate cerebral hemodynamic responses to interventions and is therefore capable of guiding more individualized acupuncture strategies.The auricular acupuncture intervention improved hemodynamic responses in patients suffering from hypertension.

Effects of different concentrations of TiAl6V4 particles on MC3T3-E1 cells and bone in rats

Three-dimensional(3D)-printed porous Ti6Al4V implants have good mechanical properties and excellent biocompatibility.As such,these implants are widely used in orthopedics.Particles adhere between the sintered and nonsintered interfaces of the porous samples during 3D printing.These excess particles can be cleaned by blowing the particles and via ultrasound,but the excess internal particles of complex structural parts are difficult to remove.During long-term cyclic loading,stress and strain can cause residual Ti6Al4V particles in the pores of the implant to shed.These detached Ti6Al4V particles are in extensive contact with osteoblasts and scattered around the implant.In this study,we examined the effects of different concentrations of Ti6Al4V particles on osteoblasts and bones.MC3T3-E1 cells were used to evaluate the effects of different concentrations of Ti6Al4V particles on cells after 72 h on the basis of the expression levels of genes,involving osteopontin,alkaline phosphatase,bone morphogenetic protein-2 and runt-related transcription factor-2.Microtubule-associated protein 1 light chain 3 was used to detect the autophagy of MC3T3-E1 with different concentrations of Ti6Al4V particles.The distal femoral defects of rats were examined to examine bone growth with different concentrations of Ti6Al4V particles.All rats were accepted by micro-CT and biochemical analyses after 12 weeks.The results indicated that 10 and 100μg/ml of Ti6Al4V particles may improve osteogenic differentiation.Micro-CT revealed that low concentrations of Ti6Al4V particles may improve the osteogenesis of the rats.However,the(cortical and trabecular)BMD of middle and high dose groups was no significant change compared with control group.In conclusion,low-dose residual particles do not inhibit osteoblast differentiation and do not decrease the bone mineral density of rats.