Research progress on transcranial electrical stimulation for deep brain stimulation / 生物医学工程学杂志

Transcranial electric stimulation (TES) is a non-invasive, economical, and well-tolerated neuromodulation technique. However, traditional TES is a whole-brain stimulation with a small current, which cannot satisfy the need for effectively focused stimulation of deep brain areas in clinical treatment. With the deepening of the clinical application of TES, researchers have constantly investigated new methods for deeper, more intense, and more focused stimulation, especially multi-electrode stimulation represented by high-precision TES and temporal interference stimulation. This paper reviews the stimulation optimization schemes of TES in recent years and further analyzes the characteristics and limitations of existing stimulation methods, aiming to provide a reference for related clinical applications and guide the following research on TES. In addition, this paper proposes the viewpoint of the development direction of TES, especially the direction of optimizing TES for deep brain stimulation, aiming to provide new ideas for subsequent research and application.

Microneedle-based devices for point-of-care infectious disease diagnostics

Recent infectious disease outbreaks, such as COVID-19 and Ebola, have highlighted the need for rapid and accurate diagnosis to initiate treatment and curb transmission. Successful diagnostic strategies critically depend on the efficiency of biological sampling and timely analysis. However, current diagnostic techniques are invasive/intrusive and present a severe bottleneck by requiring specialist equipment and trained personnel. Moreover, centralised test facilities are poorly accessible and the requirement to travel may increase disease transmission. Self-administrable, point-of-care (PoC) microneedle diagnostic devices could provide a viable solution to these problems. These miniature needle arrays can detect biomarkers in/from the skin in a minimally invasive manner to provide (near-) real-time diagnosis. Few microneedle devices have been developed specifically for infectious disease diagnosis, though similar technologies are well established in other fields and generally adaptable for infectious disease diagnosis. These include microneedles for biofluid extraction, microneedle sensors and analyte-capturing microneedles, or combinations thereof. Analyte sampling/detection from both blood and dermal interstitial fluid is possible. These technologies are in their early stages of development for infectious disease diagnostics, and there is a vast scope for further development. In this review, we discuss the utility and future outlook of these microneedle technologies in infectious disease diagnosis.

Effects of Transcranial Alternating Current Stimulation on Serial Reaction Time Task / 中国康复理论与实践

Objective:To investigate the effects of transcranial alternating current stimulation (tACS) on electroencephalography (EEG) rhythm and cognitive function. Methods:In December, 2017, 60 healthy young volunteers were divided into four groups equally, who accepted 20 Hz real or sham tACS on left C3 or right C4. They were asked to complete four types of finger sequence key pressing tasks (left/right hand random/regular key pressing) before and after stimulation, while the EEG signals were collected and the reaction time and accuracy were observed. EEG signals were analyzed with multiple difference analysis of event-related spectral perturbation. Results:The reaction time of contralateral hand reduced after C4 real stimulation. Conclusion:Right 20 Hz tACS can improve the learning of contralateral limb sequential movement.

The Application of Brain Stimulation in Psychiatric Disorders: An Overview

Based on advances in biotechnology and neuroscience, neuromodulation is poised to gain clinical importance as a treatment modality for psychiatric disorders. In addition to old-established electroconvulsive therapy (ECT), clinicians are expected to understand newer forms of neurostimulation, such as deep brain stimulation (DBS), vagus nerve stimulation (VNS), repetitive transcranial magnetic stimulation (rTMS), transcranial direct current stimulation (tDCS) and transcranial alternating current stimulation (tACS). Given the growing interest in non-invasive neuromodulation technologies, clinicians may seek sufficient information about neuromodulation to inform their clinical practice. A growing literature suggests that applications of non-invasive neuromodulation have evidence particularly for indications where treatments are currently insufficient, such as drug-resistant depression. However, positive neuromodulation studies require replication, and the precise interactions among stimulation, antidepressant medication, and psychotherapy are unknown. Further studies of long-term safety and the impact on the developing brain are needed. Non-invasive neuromodulatory devices could enable more individualized treatment. However, do-it-yourself (DIY) stimulation kits require a better understanding of the effects of more frequent patterns of stimulation and raise concerns about clinical supervision, regulation, and reimbursement. Wide spread enthusiasm for therapeutic potential of neuromodulation in clinical practice settings should be mitigated by the fact that there are still research gaps and challenges associated with non-invasive neuromodulatory devices.

Immunosensor construction of label free detection of CD4+T lymphocytes / 国际检验医学杂志

Objective To construct an immunosensor for detecting CD4+ T lymphocytes without labeling .Methods The staphy-lococcus protein A(SPA) method was adopted to conduct the oriented immobilization of CD4 monoclonal antibodies on the gold in-terdigitated microelectrode surface for capturing CD4+ T lymphocytes .Then cyclic voltammetry(CV) method was used to conduct the representation of modification situation on the gold interdigitated microelectrode surface .Finally the electrochemical impedance spectroscopy(EIS) was used to detect the impedance of CD4+ T lymphocytes captured by the immunosensor .The standard curve was drawn by the impedance values change obtained by the equivalent electric circuit fitting .Results The linear range of this im-munosensor for detecting CD4+ T lymphocytes was (5 × 103 -5 .0 × 106 )/mL ,with lower detection limit of 5 .0 × 102/mL .Conclu-sion The constructed immunosensor has accurate and reliable detection results uhidn is simple to operate accurate ,convenient and cheap ,which might be expected to be used in the real-time detection system ,and offers help for realizing rapid ,accurate and inex-pensive CD4+ T lymphocyte count .

Investigating Effects of Nano- to Micro-Ampere Alternating Current Stimulation on Trichophyton rubrum Growth

BACKGROUND: Fungi are eukaryotic microorganisms including yeast and molds. Many studies have focused on modifying bacterial growth, but few on fungal growth. Microcurrent electricity may stimulate fungal growth. OBJECTIVE: This study aims to investigate effects of microcurrent electric stimulation on Trichophyton rubrum growth. METHODS: Standard-sized inoculums of T. rubrum derived from a spore suspension were applied to potato dextrose cornmeal agar (PDACC) plates, gently withdrawn with a sterile pipette, and were applied to twelve PDACC plates with a sterile spreader. Twelve Petri dishes were divided into four groups. The given amperage of electric current was 500 nA, 2 µA, and 4 µA in groups A, B, and C, respectively. No electric current was given in group D. RESULTS: In the first 48 hours, colonies only appeared in groups A and B (500 nA and 2 µA exposure). Colonies in group A (500 nA) were denser. Group C (4 µA) plates showed a barely visible film of fungus after 96 hours of incubation. Fungal growth became visible after 144 hours in the control group. CONCLUSION: Lower intensities of electric current caused faster fungal growth within the amperage range used in this study. Based on these results, further studies with a larger sample size, various fungal species, and various intensities of electric stimulation should be conducted.

Effect of Exposure to a High-Voltage Alternating Current Electric Field on Muscle Extensibility / 日本温泉気候物理医学会雑誌

<b>Background:</b> To investigate the effect of high-voltage alternating current (AC) electric field exposure on muscle extensibility. <BR><b>Methods:</b> The study design was a crossover comparison. Fifteen healthy men were randomly divided into two groups. The interventions were exposure and no exposure to a high-voltage AC electric field (18 kV, 30 min). Subjects then performed bilateral self-stretching of the trapezius, hamstrings, and rectus femoris. Skin temperature, blood flow rate, blood pressure, heart rate, muscle rigidity, and muscle extensibility were measured before and after the intervention, and muscle rigidity and muscle extensibility were measured again after stretching. Skin temperature was measured bilaterally on the palms, shoulder girdle, anterior thigh, and dorsum of foot. Blood flow rate was measured in the right radial artery and dorsal artery of the foot. Muscle rigidity was measured bilaterally in the trapezius, rectus femoris, and biceps femoris. Muscle extensibility indices were determined for the left and right angle of lateral neck flexion, heel-buttock distance, straight leg raise angle, and sit-and-reach distance. Skin temperature, blood flow rate, blood pressure, and heart rate were compared between before and after the intervention, and muscle rigidity and muscle extensibility were compared before and after the intervention and after stretching.<BR><b>Results:</b> A significant improvement was found in muscle extensibility in the intervention group but not in the controls. Muscle extensibility improvements due to stretching were noted regardless of electric field exposure, but the degree and percentage of change in muscle extensibility was significantly higher after stretching following electric field exposure. Electric field exposure had no effect on muscle rigidity or circulatory dynamics.<BR><b>Conclusions:</b> Exposure to the high-voltage AC electric field appeared to increase muscle extensibility and heighten the effect of stretching. However, as the mechanism for improved muscle extensibility due to high-voltage AC electric field exposure was not clear, further study is necessary.

Effect of Exposure to a High-Voltage Alternating Current Electric Field on Muscle Extensibility / 日本温泉気候物理医学会雑誌

Background: To investigate the effect of high-voltage alternating current (AC) electric field exposure on muscle extensibility. Methods: The study design was a crossover comparison. Fifteen healthy men were randomly divided into two groups. The interventions were exposure and no exposure to a high-voltage AC electric field (18 kV, 30 min). Subjects then performed bilateral self-stretching of the trapezius, hamstrings, and rectus femoris. Skin temperature, blood flow rate, blood pressure, heart rate, muscle rigidity, and muscle extensibility were measured before and after the intervention, and muscle rigidity and muscle extensibility were measured again after stretching. Skin temperature was measured bilaterally on the palms, shoulder girdle, anterior thigh, and dorsum of foot. Blood flow rate was measured in the right radial artery and dorsal artery of the foot. Muscle rigidity was measured bilaterally in the trapezius, rectus femoris, and biceps femoris. Muscle extensibility indices were determined for the left and right angle of lateral neck flexion, heel-buttock distance, straight leg raise angle, and sit-and-reach distance. Skin temperature, blood flow rate, blood pressure, and heart rate were compared between before and after the intervention, and muscle rigidity and muscle extensibility were compared before and after the intervention and after stretching. Results: A significant improvement was found in muscle extensibility in the intervention group but not in the controls. Muscle extensibility improvements due to stretching were noted regardless of electric field exposure, but the degree and percentage of change in muscle extensibility was significantly higher after stretching following electric field exposure. Electric field exposure had no effect on muscle rigidity or circulatory dynamics. Conclusions: Exposure to the high-voltage AC electric field appeared to increase muscle extensibility and heighten the effect of stretching. However, as the mechanism for improved muscle extensibility due to high-voltage AC electric field exposure was not clear, further study is necessary.

New improvement of iontophoresis / 医疗卫生装备

Iontophoresis possesses the unique superiority as an effective way for promoting the permeability in a therapy system which gives medicine through human' skin directly.It has been developing very quickly in recent years.The application of DC,pulse DC and the electroporation causes the flux greatly enhanced,especially the application of electroporation which can fast reduced the skin resistance and enhance the flux for its reversible function to the skin.What's more,there has been an improved way for iontophoresis now,which uses the AC with an offset of DC.This method can stabilize the skin resistance so as to stabilize the human epidermis membrane parameters,including the pore area,the pore distribution,the pore surface charge density,thus keeping the flux constant.