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1.
Environ Sci Pollut Res Int ; 30(54): 115585-115599, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37882928

ABSTRACT

Small streams are essential parts of water ecosystems, such as rivers, lakes, and reservoirs, performing vital functions in the attenuation of nutrient pollution. As eutrophication becomes an increasingly severe problem in waters, it is necessary to investigate how to improve nutrient retention potential in streams. In this study, the effect of artificial manipulation was examined on transient storage and nutrient uptake in streams by setting up the stepping stone structures of flying-geese pattern (SG) and the combination mode of SG and bilaterally staggered spur dikes (SG+SD) in the channel. The tracer experiments were performed to confirm the effectiveness of SG and SG+SD in two headwater streams, which are tributaries of the Chaohu Lake basin. Additionally, the transient storage and nutrient uptake potential were assessed by the OTIS (one-dimensional transport with inflow and storage) model and the nutrient spiraling theory. Compared with the control, the implementation of SG in the Banqiao River increased the retention of ammonium (NH4+) and phosphate (PO43). Furthermore, the transient storage capacity and nutrient uptake potential in the Ershibu River were strengthened with the addition of bilaterally staggered spur dikes based on SG. These results highlight the importance of manipulating the geomorphology of the streambed to enhance the nutrient retention potential in streams.


Subject(s)
Ecosystem , Rivers , Animals , Rivers/chemistry , Geese , Environmental Monitoring/methods , Nitrogen/analysis , Nutrients , Phosphorus/analysis
2.
Sci Total Environ ; 905: 167166, 2023 Dec 20.
Article in English | MEDLINE | ID: mdl-37730034

ABSTRACT

Bisphenol S (BPS), being structurally similar to bisphenol A (BPA), has been widely used as an alternative to BPA in industrial applications. However, in-depth studies on the environmental behavior and fate of BPS in various soils have been rarely reported. Here, 14C-labeled BPS was used to investigate its mineralization, bound residues (BRs) formation and extractable residues (ERs) in three soils for 64 days. Significant differences were found in the dissipation rates of BPS in three soils with different pH values. The dissipation of BPS followed pseudo first-order kinetics with half-lives (T1/2) of 15.2 ± 0.1 d, 27.0 ± 0.2 d, 180.4 ± 5.3 d, and 280.5 ± 3.3 d in the alkaline soil (fluvo-aquic soil, FS), the neutral soil (cinnamon soil, CS), the acidic soil (red soil, RS), and sterilized cinnamon soil (CS-S), respectively. The mineralization and BRs formation contributed the most to the dissipation of BPS in soil. BPS was persistent in acidic soil, and may pose a significant threat to plants grown in acidic soils. Additionally, soil microorganisms played a key role in BPS degradation, and the organic matter content might be a major factor that promotes the adsorption and degradation of BPS in soils. Two transformed products, P-hydroxybenzenesulfonic acid and methylated BPS were identified in soils. This study provides new insights into the fate of BPS in various soils, which will be useful for risk assessments of BPS in soil.

3.
Entropy (Basel) ; 25(7)2023 Jun 25.
Article in English | MEDLINE | ID: mdl-37509926

ABSTRACT

Ciphertext-Policy Attribute-Based Encryption (CP-ABE) technology provides a new solution to address the security and fine-grained access control of traffic information in vehicular ad hoc networks (VANETs). However, in most CP-ABE schemes for VANETs, attribute revocation suffers from high system consumption and complex revocation operations, as well as from high computational overhead and low efficiency due to the use of bilinear pairwise operations. Based on this, this paper proposes a lightweight CP-ABE scheme that supports direct attribute revocation in VANETs. The scheme implements an agent-based direct attribute revocation mechanism by separating dynamic and static attributes of vehicle terminals, which reduces system consumption and simplifies the revocation operation process. The scheme uses scalar multiplication on elliptic curves instead of bilinear pairing operations and uses computational outsourcing techniques to reduce the terminal decryption cost and improve the efficiency of the scheme. The security and performance analysis shows that the overall efficiency of our scheme is better than the existing schemes under the premise of ensuring data confidentiality and integrity.

4.
Entropy (Basel) ; 25(5)2023 May 17.
Article in English | MEDLINE | ID: mdl-37238566

ABSTRACT

Blockchain technology affords data integrity protection and building trust mechanisms in transactions for distributed networks, and, therefore, is seen as a promising revolutionary information technology. At the same time, the ongoing breakthrough in quantum computation technology contributes toward large-scale quantum computers, which might attack classic cryptography, seriously threatening the classic cryptography security currently employed in the blockchain. As a better alternative, a quantum blockchain has high expectations of being immune to quantum computing attacks perpetrated by quantum adversaries. Although several works have been presented, the problems of impracticality and inefficiency in quantum blockchain systems remain prominent and need to be addressed. First, this paper develops a quantum-secure blockchain (QSB) scheme by introducing a consensus mechanism-quantum proof of authority (QPoA) and an identity-based quantum signature (IQS)-wherein QPoA is used for new block generation and IQS is used for transaction signing and verification. Second, QPoA is developed by adopting a quantum voting protocol to achieve secure and efficient decentralization for the blockchain system, and a quantum random number generator (QRNG) is deployed for randomized leader node election to protect the blockchain system from centralized attacks like distributed denial of service (DDoS). Compared to previous work, our scheme is more practical and efficient without sacrificing security, greatly contributing to better addressing the challenges in the quantum era. Extensive security analysis demonstrates that our scheme provides better protection against quantum computing attacks than classic blockchains. Overall, our scheme presents a feasible solution for blockchain systems against quantum computing attacks through a quantum strategy, contributing toward quantum-secured blockchain in the quantum era.

6.
Biosens Bioelectron ; 209: 114263, 2022 Aug 01.
Article in English | MEDLINE | ID: mdl-35483214

ABSTRACT

Clinical transplantation of human embryonic stem cells derived dopaminergic neurons (hESC-DDNs) is expected to be a potential therapy for treating neurodegenerative diseases. However, the assessment of the physiological functions, including electrophysiology and dopamine (DA) vesicular exocytosis of hESC-DDNs are not impeccable currently, which deeply limits the clinical application of hESC-DDNs. To overcome this challenge, we developed a multifunctional microelectrode array (MEA) which can detect both electrophysiological signals and DA vesicular exocytosis. The reduced oxidation graphene, poly(3,4-ethylenedioxythiophene) and poly (sodium-4-styrenesultanate) nanocomposites (rGO/PEDOT:PSS) were electrochemically deposited on the MEAs to improve their electrical characterizations with low impedance and small phase delay, and electrochemical characterizations with low oxidation potential, low detection limit, high sensitivity, wide linear range and high sensitivity. In the hESC-DDNs experiment, the modified MEA could detect electrophysiological signals with low noise (25 µV) and high signal-to-noise ratio (>5.4), and the weak current signals generated by DA vesicular exocytosis with high sensitivity (∼pA), high time resolution (sub-millisecond) and low noise (3 pA). Moreover, due to increased accuracy, the MEA could clearly distinguish two typical kinds of exocytosis spike events ("Spikes with foot" and "Spikes without foot") and found that the slow and low release through the fusion pore was an important mode of DA vesicular exocytosis in hESC-DDNs. Our work proved that the hESC-DDNs had the basic physiological functions as human dopaminergic neurons, which would be beneficial to the clinical application of the hESC-DDNs.


Subject(s)
Biosensing Techniques , Human Embryonic Stem Cells , Dopamine , Dopaminergic Neurons , Electrophysiology , Exocytosis , Humans , Microelectrodes
7.
ACS Appl Mater Interfaces ; 14(13): 15736-15746, 2022 Apr 06.
Article in English | MEDLINE | ID: mdl-35294190

ABSTRACT

When it comes to mechanisms of brain functions such as learning and memory mediated by neural networks, existing multichannel electrophysiological detection and regulation technology at the cellular level does not suffice. To address this challenge, a 128-channel microelectrode array (MEA) was fabricated for electrical stimulation (ES) training and electrophysiological recording of the hippocampal neurons in vitro. The PEDOT:PSS/PtNPs-coated microelectrodes dramatically promote the recording and electrical stimulation performance. The MEA exhibited low impedance (10.94 ± 0.49 kohm), small phase delay (-12.54 ± 0.51°), high charge storage capacity (14.84 ± 2.72 mC/cm2), and high maximum safe injection charge density (4.37 ± 0.22 mC/cm2), meeting the specific requirements for training neural networks in vitro. A series of ESs at various frequencies was applied to the neuronal cultures in vitro, seeking the optimum training mode that enables the neuron to display the most obvious plasticity, and 1 Hz ES was determined. The network learning process, including three consecutive trainings, affected the original random spontaneous activity. Along with that, the firing pattern gradually changed to burst and the correlation and synchrony of the neuronal activity in the network have progressively improved, increasing by 314% and 240%, respectively. The neurons remembered these changes for at least 4 h. Collectively, ES activates the learning and memory functions of neurons, which is manifested in transformations in the discharge pattern and the improvement of network correlation and synchrony. This study offers a high-performance MEA revealing the underlying learning and memory functions of the brain and therefore serves as a useful tool for the development of brain functions in the future.


Subject(s)
Bridged Bicyclo Compounds, Heterocyclic , Neurons , Hippocampus/physiology , Microelectrodes , Neurons/physiology , Polymers
8.
ACS Sens ; 7(2): 584-592, 2022 02 25.
Article in English | MEDLINE | ID: mdl-35060694

ABSTRACT

Both programmed death-1 (PD-1) and programmed death-ligand 1 (PD-L1) are important proteins in cancer immunotherapy. Soluble forms (sPD-1 and sPD-L1) have potential for determining treatment and prognosis monitoring. However, there is a lack of detection methods for point-of-care testing (POCT) of these two proteins, so a low-cost rapid detection platform is urgently needed. To solve this problem, a dual-channel electrochemical platform, including a folding paper-based immunosensor and a POCT system for rapid simultaneous detection of these two proteins was designed and fabricated. The immunosensor consists of a three-electrode system and a reaction cell. The surface of the working electrode was modified with nanocomposites synthesized from amine-functionalized single-walled carbon nanotubes, new methylene blue, and gold nanoparticles. Antibodies to sPD-1 and sPD-L1 were also immobilized on the working electrode surface. A differential pulse voltammetry electrochemical method was adopted. The immunosensor was able to detect sPD-1 and sPD-L1 in the ranges of 50 pg/mL to 50 ng/mL and 5 pg/mL to 5 ng/mL, respectively. The limits of detection were 10 and 5 pg/mL. Using this detection platform, sPD-1 and sPD-L1 in plasma were detected by both enzyme-linked immunosorbent assay and the immunosensor, which has good application potential.


Subject(s)
Biosensing Techniques , Metal Nanoparticles , Nanotubes, Carbon , B7-H1 Antigen , Gold , Immunoassay , Point-of-Care Testing
9.
IEEE Trans Image Process ; 31: 541-555, 2022.
Article in English | MEDLINE | ID: mdl-34890330

ABSTRACT

Copy-move forgery detection identifies a tampered image by detecting pasted and source regions in the same image. In this paper, we propose a novel two-stage framework specially for copy-move forgery detection. The first stage is a backbone self deep matching network, and the second stage is named as Proposal SuperGlue. In the first stage, atrous convolution and skip matching are incorporated to enrich spatial information and leverage hierarchical features. Spatial attention is built on self-correlation to reinforce the ability to find appearance similar regions. In the second stage, Proposal SuperGlue is proposed to remove false-alarmed regions and remedy incomplete regions. Specifically, a proposal selection strategy is designed to enclose highly suspected regions based on proposal generation and backbone score maps. Then, pairwise matching is conducted among candidate proposals by deep learning based keypoint extraction and matching, i.e., SuperPoint and SuperGlue. Integrated score map generation and refinement methods are designed to integrate results of both stages and obtain optimized results. Our two-stage framework unifies end-to-end deep matching and keypoint matching by obtaining highly suspected proposals, and opens a new gate for deep learning research in copy-move forgery detection. Experiments on publicly available datasets demonstrate the effectiveness of our two-stage framework.


Subject(s)
Attention
10.
Article in English | MEDLINE | ID: mdl-34653004

ABSTRACT

Acupoint specificity for diseases has consistently been the focus of acupuncture research owing to its excellent prospects for clinical diagnosis and treatment. However, the specificity of cardiovascular and sleep functions in terms of electrical signals at acupoints remains unclear. In this study, five volunteers were recruited and their electrophysiological signals of GV20 (baihui), RN17 (danzhong), PC6 (neiguan), and SP6 (sanyinjiao) and the corresponding sham points, Pittsburgh sleep quality index, blood pressure, and echocardiography were monitored over four periods of 90-day head-down bed rest (HDBR). The results demonstrated that the power and characteristic amplitude of the acupoints were more significant than those of the sham points under normal conditions. And along with the altered physiological condition of the body after HDBR, the differential signal characteristic amplitude (DSCA) and the power of the acupoints were decreased to a larger extent than those of the sham points. In addition, the difference between the power of acupuncture and sham points was also reduced. During the recovery period, except for GV20, the power and DSCA of other acupoints did not return to normal. In terms of DSCA, GV20 is related to human sleep function and other acupoints are related to cardiovascular function. The above results show that the electrophysiological signals of acupoints are disease-specific and more accurately reflect the changes of physiological homeostasis. The research conduces to the development of acupuncture-based disease diagnosis and treatment integrated methods, and the realization of the portable and accurate diagnosis and regulation of diseases in space medicine.


Subject(s)
Acupuncture Therapy , Weightlessness , Acupuncture Points , Electrophysiological Phenomena , Humans , Sleep
11.
ACS Sens ; 6(9): 3377-3386, 2021 09 24.
Article in English | MEDLINE | ID: mdl-34410704

ABSTRACT

Accurate detection of the degree of isoflurane anesthesia during a surgery is important to avoid the risk of overdose isoflurane anesthesia timely. To address this challenge, a four-shank implantable microelectrode array (MEA) was fabricated for the synchronous real-time detection of dual-mode signals [electrophysiological signal and dopamine (DA) concentration] in rat striatum. The SWCNTs/PEDOT:PSS nanocomposites were modified onto the MEAs, which significantly improved the electrical and electrochemical performances of the MEAs. The electrical performance of the modified MEAs with a low impedance (16.20 ± 1.68 kΩ) and a small phase delay (-27.76 ± 0.82°) enabled the MEAs to detect spike firing with a high signal-to-noise ratio (> 3). The electrochemical performance of the modified MEAs with a low oxidation potential (160 mV), a low detection limit (10 nM), high sensitivity (217 pA/µM), and a wide linear range (10 nM-72 µM) met the specific requirements for DA detection in vivo. The anesthetic effect of isoflurane was mediated by inhibiting the spike firing of D2_SPNs (spiny projection neurons expressing the D2-type DA receptor) and the broadband oscillation rhythm of the local field potential (LFP). Therefore, the spike firing rate of D2_SPNs and the power of LFP could reflect the degree of isoflurane anesthesia together. During the isoflurane anesthesia-induced death procedure, we found that electrophysiological activities and DA release were strongly inhibited, and changes in the DA concentration provided more details regarding this procedure. The dual-mode recording MEA provided a detection method for the degree of isoflurane anesthesia and a prediction method for fatal overdose isoflurane anesthesia.


Subject(s)
Anesthesia , Isoflurane , Animals , Bridged Bicyclo Compounds, Heterocyclic , Dopamine , Microelectrodes , Polymers , Rats
12.
Int Immunopharmacol ; 99: 107933, 2021 Oct.
Article in English | MEDLINE | ID: mdl-34224993

ABSTRACT

T cell immunoglobulin and mucin domain 3 (TIM-3) was originally found to be expressed on the surface of Th1 cells, acting as a negative regulator and binding to the ligand galectin-9 to mediate Th1 cell the apoptosis. Recent studies have shown that TIM-3 is also expressed on other immune cells, such as macrophages, dendritic cells, and monocytes. In addition, TIM-3 ligands also include Psdter, High Mobility Group Box 1 (HMGB1) and Carcinoembryonic antigen associated cell adhesion molecules (Ceacam-1), which have different effects upon biding to different ligands on immune cells. Studies have shown that TIM-3 plays an important role in autoimmune diseases, chronic viral infections and tumors. A large amount of experimental data supports TIM-3 as an immune checkpoint, and targeting TIM-3 is a promising treatment method in current immunotherapy, especially the new combination of other immune checkpoint blockers. In this review, we summarize the role of TIM-3 in different diseases and its possible signaling pathway mechanisms, providing new insights for better breakthrough immunotherapy.


Subject(s)
Autoimmune Diseases/metabolism , Biomarkers/metabolism , Hepatitis A Virus Cellular Receptor 2/metabolism , Immune Checkpoint Inhibitors/metabolism , Neoplasms/metabolism , Virus Diseases/metabolism , Animals , Antigens, CD/metabolism , Carcinoembryonic Antigen/metabolism , Cell Adhesion , Cell Adhesion Molecules/metabolism , Galectins/metabolism , Glycosylation , HMGB1 Protein/metabolism , Humans , Immune Tolerance , Immunotherapy , Ligands , Protein Binding , Signal Transduction , Th1 Cells
13.
Micromachines (Basel) ; 12(6)2021 Jun 03.
Article in English | MEDLINE | ID: mdl-34205055

ABSTRACT

Temporal lobe epilepsy (TLE) is a form of refractory focal epilepsy, which includes a latent period and a chronic period. Microelectrode arrays capable of multi-region detection of neural activities are important for accurately identifying the epileptic focus and pathogenesis mechanism in the latent period of TLE. Here, we fabricated multi-shank MEAs to detect neural activities in the DG, hilus, CA3, and CA1 in the TLE rat model. In the latent period in TLE rats, seizures were induced and changes in neural activities were detected. The results showed that induced seizures spread from the hilus and CA3 to other areas. Furthermore, interneurons in the hilus and CA3 were more excited than principal cells and exhibited rhythmic oscillations at approximately 15 Hz in grand mal seizures. In addition, the power spectral density (PSD) of neural spikes and local field potentials (LFPs) were synchronized in the frequency domain of the alpha band (9-15 Hz) after the induction of seizures. The results suggest that fabricated MEAs have the advantages of simultaneous and precise detection of neural activities in multiple subregions of the hippocampus. Our MEAs promote the study of cellular mechanisms of TLE during the latent period, which provides an important basis for the diagnosis of the lesion focus of TLE.

14.
IEEE Trans Biomed Eng ; 68(1): 19-25, 2021 01.
Article in English | MEDLINE | ID: mdl-32356734

ABSTRACT

OBJECTIVE: Epilepsy affects 50 million people worldwide and its pathogenesis is still unknown. In particular, the movement-related neural activities involving glutamate (Glu) and electrophysiological signals at cellular level remains unclear. METHODS: A cellular-scale implantable microelectrode array (MEA) was fabricated to detect the movement-related neural activities involving Glu concentration and electrophysiological signals. Platinum and reduced graphene oxide nanocomposites were deposited to enhance the surface area. Glu oxidase (Gluox) were coated to effectively recognize Glu molecule. RESULTS: Neural activities in the hippocampus of normal and epileptic mice is different, and the changes are closely connected with movement. Glu concentration and spike firing rate in the epileptic mice were much higher than those in the normal ones. And the neural activities with significant synchronization were detected in the epileptic mice even without seizure occurrence. Meanwhile, the spikes fire more intensively and Glu level became much higher during the movement of the mice compared to the stationary state. CONCLUSION: The existing abnormality of neural activities in the epileptic mice are potential factors to induce a seizure. Movement may impact the neural activities and the duration of seizure. SIGNIFICANCE: The MEA can monitor changes of movement, Glu and neuron discharges synchronously and provides us an effective technology to understand the neuronal disease.


Subject(s)
Epilepsy , Wakefulness , Animals , Hippocampus , Mice , Microelectrodes , Neurons
15.
ACS Appl Bio Mater ; 4(11): 8013-8022, 2021 11 15.
Article in English | MEDLINE | ID: mdl-35006782

ABSTRACT

Epilepsy detection and focus location are urgent issues that need to be solved in epilepsy research. A cortex conformable and fine spatial accuracy electrocorticogram (ECoG) sensor array, especially for real-time detection of multicortical functional regions and delineating epileptic focus remains a challenge. Here, we fabricated a polydimethylsiloxane (PDMS)-parylene hybrid, flexible micro-ECoG electrode array. The multiwalled carbon nanotubes (MWCNTs)/poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) nanocomposite-modified electrode interface significantly improved the sensing performance with low impedance (20.68 ± 6.65 kΩ), stable phase offset, and high sensitivity. The electrophysiological activities of multicortical brain regions (somatosensory cortex, parietal association cortex, and visual cortex) were simultaneously monitored during normal and epileptic statuses. The epileptic ECoG activities spread spatiotemporally from the starting point toward the adjacent cortex. Significant variations of the waveform, power, and frequency band were observed. The ECoG potential (123 ± 23 µV) at normal status was prominently up to 417 ± 87 µV at the spike wave stage. Besides, the power for epileptic activity (11.049 ± 4.513 µW) was 10 times higher than that (1.092 ± 0.369 µW) for normal activity. In addition, the theta frequency band was found to be a characteristic frequency band of epileptic signals. These joint analysis results of multicortical regions indicated that the active micron-scale region on the parietal association cortex was more likely to be the epileptogenic focus. Cortical mapping with high spatial detail provides the accurate delineation of lesions. The flexible micro-ECoG electrode array is a powerful tool for constructing a spatiotemporal map of the cortex. It provides a technical platform for epileptic focus location, biomedical diagnosis, and brain-computer interaction.


Subject(s)
Epilepsy , Nanotubes, Carbon , Brain/physiology , Dimethylpolysiloxanes , Electrodes , Epilepsy/diagnosis , Humans , Polymers , Xylenes
16.
ACS Appl Bio Mater ; 4(6): 4872-4884, 2021 06 21.
Article in English | MEDLINE | ID: mdl-35007036

ABSTRACT

In this study, a biosensor assembly based on microelectrode arrays (MEAs) modified with PtNPt/MWCNT-PEDOT:PSS nanocomposites is presented to synchronously detect the dopamine (DA) and electrophysiological activities in rat brains. Different morphological and electrochemical characterizations were conducted to show the excellent mechanical and electrical properties of the as-prepared probes. The developed biosensors realized the sensitive and selective detection of DA with the existence of significant interferences such as uric acid (UA), ascorbic acid (AA), glutamate (Glu), and 3,4-dihydroxyphenylacetic acid (DOPAC). Calibration curve for the DA response was linear with the concentration from 0.05 µM to 79 µM (R = 0.999), with a sensitivity of 30.561 pA/µM and detection limit as low as 50 nM. Finally, the proposed microelectrode was applied to be implanted into the cortex and caudate putamen (CPU) of rats, which was demonstrated to stably measure the synchronous neurochemical and neurophysiological changes caused by 72 h sleep deprivation. The in vivo measuring results showed that the sleep deprivation increased the DA release and neural spike activity in both cortex and CPU. The local field potential (LFP) power in the delta and theta band was significantly increased as well. These changes in brain may reflect the brain's adaptive reaction toward the side effects induced by sleep deprivation and may partially explain the mechanism of forced wakefulness in the presence of accumulated sleep pressure.


Subject(s)
Biosensing Techniques , Brain/metabolism , Brain/physiology , Dopamine/metabolism , Sleep Deprivation/metabolism , Sleep Deprivation/physiopathology , Animals , Bridged Bicyclo Compounds, Heterocyclic , Male , Metal Nanoparticles , Microelectrodes , Nanotubes, Carbon , Platinum , Polymers , Polystyrenes , Rats, Sprague-Dawley
17.
Biosensors (Basel) ; 10(10)2020 Sep 28.
Article in English | MEDLINE | ID: mdl-32998190

ABSTRACT

(1) Background: Deep brain stimulation (DBS) is considered as an efficient treatment method for alleviating motor symptoms in Parkinson's disease (PD), while different stimulation frequency effects on the specific neuron patterns at the cellular level remain unknown. (2) Methods: In this work, nanocomposites-modified implantable microelectrode arrays (MEAs) were fabricated to synchronously record changes of dopamine (DA) concentration and striatal neuron firing in the striatum during subthalamic nucleus DBS, and different responses of medium spiny projecting neurons (MSNs) and fast spiking interneurons (FSIs) to DBS were analyzed. (3) Results: DA concentration and striatal neuron spike firing rate showed a similar change as DBS frequency changed from 10 to 350 Hz. Note that the increases in DA concentration (3.11 ± 0.67 µM) and neural spike firing rate (15.24 ± 2.71 Hz) were maximal after the stimulation at 100 Hz. The MSNs firing response to DBS was significant, especially at 100 Hz, while the FSIs remained stable after various stimulations. (4) Conclusions: DBS shows the greatest regulatory effect on DA concentration and MSNs firing rate at 100 Hz stimulation. This implantable MEA in the recording of the neurotransmitter and neural spike pattern response to DBS provides a new insight to understand the mechanism of PD at the cellular level.


Subject(s)
Microelectrodes , Neurons , Parkinson Disease , Action Potentials , Animals , Corpus Striatum , Dopamine , Male , Monitoring, Physiologic , Rats
18.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 880-883, 2020 07.
Article in English | MEDLINE | ID: mdl-33018125

ABSTRACT

Parkinson's disease (PD) is characterized by excessively synchronized neural activity. In this paper, we recorded electrophysiological signals in Cortex of normal and PD mode monkey using homemade implantable microelectrode arrays (MEA), and analyzed the characteristics of action potentials (APs) and local field potentials (LFPs). Results showed that, comparing to normal monkey, the spike-firing activity of PD mode monkey could be divided into two stages: the continuous spike-firing stage and the burst spike-firing stage. The continuous spike-firing lasted for about 20s and oscillated at low frequency about 0.03Hz. APs fired in a burst mode between two continuous discharges. In the continuous spike-firing stage, the spike-firing activity was related to the ripple rhythm (100-200Hz) of LFPs with a coherence 0.86, while, in the burst spike-firing stage, it was related to the phase of theta rhythm (4-7 Hz). APs tended to discharge in the valley of theta rhythm (average peak phase is -10°).Clinical Relevance- This article can provide some references for the study of PD neuropathology.


Subject(s)
Parkinson Disease , Action Potentials , Animals , Cerebral Cortex , Haplorhini , Microelectrodes
19.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 5280-5283, 2020 07.
Article in English | MEDLINE | ID: mdl-33019175

ABSTRACT

Depression is a harmful disease with high incidence. However, no effective method based on physiological information detection has been published to diagnose depression. Electroencephalography (EEG) has been used as a tool to detect physiological information of depressed patients and the symmetry of EEG receives much attention. This research focused on the symmetry of EEG in left and right homologous brain regions. 22 healthy volunteers and 41 volunteers of major depression were tested and three methods, average power ratio, waveform correlation and power spectral correlation, were adopted to measure the symmetry in all frequency bands and all brain regions. After t-test, homologous site pairs in particular frequency bands with significant differences between major depressed patients and controls were found out. Then sample entropy analysis was adopted, trying to figure out further connections between EEG symmetry and major depression. The accuracy tests were also taken and the average accuracy of some tests could reach 93.7%. The result of this research can hopefully serve as a theoretical basis for pattern recognition in the diagnosis of depression. The accuracy of pattern recognition based on multiple processing methods and sites will increase dramatically.


Subject(s)
Depressive Disorder, Major , Attention , Brain , Depressive Disorder, Major/diagnosis , Electroencephalography , Entropy , Humans
20.
ACS Appl Mater Interfaces ; 12(37): 41148-41156, 2020 Sep 16.
Article in English | MEDLINE | ID: mdl-32809788

ABSTRACT

Temporal lobe epilepsy (TLE) is a focal, recurrent, and refractory neurological disorder. Therefore, precisely targeted treatments for TLE are greatly needed. We designed anti-CB1 liposomes that can bind to CB1 receptors in the hippocampus to deliver photocaged compounds (ruthenium bipyridine triphenylphosphine γ-aminobutyric acid, RuBi-GABA) in the TLE rats. A 16-channel silicon microelectrode array (MEA) was implanted for simultaneously monitoring electrophysiological signals of neurons. The results showed that anti-CB1 liposomes were larger in size and remained in the hippocampus longer than unmodified liposomes. Following the blue light stimulation, the neural firing rates and the local field potentials of hippocampal neurons were significantly reduced. It is indicated that RuBi-GABA was enriched near hippocampal neurons due to anti-CB1 liposome delivery and photolyzed by optical stimulation, resulting dissociation of GABA to exert inhibitory actions. Furthermore, K-means cluster analysis revealed that the firing rates of interneurons were decreased to a greater extent than those of pyramidal neurons, which may have been a result of the uneven diffusion of RuBi-GABA due to liposomes binding to CB1. In this study, we developed a novel, targeted method to regulate neural electrophysiology in the hippocampus of the TLE rat using antibody-modified nanoliposomes, implantable MEA, and photocaged compounds. This method effectively suppressed hippocampal activities during seizure ictus with high spatiotemporal resolution, which is a crucial exploration of targeted therapy for epilepsy.


Subject(s)
Antibodies/metabolism , Coordination Complexes/chemistry , Epilepsy, Temporal Lobe/metabolism , Liposomes/metabolism , Receptor, Cannabinoid, CB1/metabolism , gamma-Aminobutyric Acid/chemistry , Animals , Disease Models, Animal , Epilepsy, Temporal Lobe/diagnosis , Microelectrodes , Particle Size , Rats , Surface Properties
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