“Flow” Transcranial Direct Current Stimulation (tDCS) for Depression Treatment in a Primary Healthcare General Practice—An Open-Label Cohort Study Measuring Montgomery-Åsberg Depression Rating Scale (MADRS-S) Outcomes

Background: Flow FL-100 is a transcranial direct current stimulation (tDCS) device self-administered by a patient at home in combination with a software application delivered wellbeing behaviour therapy training. tDCS has evidence of effectiveness in treating symptoms of depression. Purpose/Aim: This post marketing study evaluated the effect of Flow on depression for primary care general practice patients with depression symptoms. Methods: Open-label patient cohort design with no control group. Inclusion criteria were aged 18 years or over and reporting depression symptoms. Participants self-administered five 30 minute tDCS sessions per week for the first three weeks, and then 3 sessions per week following this. Three, six and ten week assessment with participant self-report measure: Montgomery- Åsberg Depression Rating Scale (MADRS-S). Results: MADRS-S remission rates were between 29% - 30% at three weeks, 33% - 34% at six-weeks and 50% at 10-weeks treatment. There was a significant improvement in MADRS-S with large effect sizes at all time points. Conclusions: Flow tDCS can be delivered through a primary healthcare general practice service and patients will choose to use. Flow tDCS provides an effective depression treatment in addition and as an alternative to antidepressants and psychotherapy. tDCS has evidence as an effective depression treatment, and the widespread availability of tDCS in primary care general practice should be considered.

Clinical Trial Demonstrates Efficacy of Transcranial Direct Current Stimulation (tDCS) in Improving Pain Management from Post-Laminectomy Syndrome

Chronic pain, a multidimensional experience affecting individuals’ sensory, cognitive, and emotional aspects, significantly impacts their quality of life. Post-laminectomy syndrome, a condition characterized by persistent back pain following spinal surgery, often leads to disability and increased healthcare utilization. Methods: This randomized, controlled, blind clinical trial aimed to investigate the efficacy of Transcranial Direct Current Stimulation (tDCS) in managing pain from post-laminectomy syndrome in patients. Twenty-four participants were assigned to three groups: sham stimulation, active stimulation over primary motor cortex (M1), or stimulation over dorsolateral prefrontal cortex (DLPFC). Stimulation was administered for five consecutive days, 20 minutes per session, using a current of 1.5 mA through 25 cm2 electrodes. Pain intensity was assessed using Visual Analog Scale (VAS) before, during, and after intervention. Results: An ANOVA model demonstrates significant reduction in pain intensity compared to baseline in VAS, (F(7, 285) = 12.292;p 0.001;Power = 1.000;η2p = 0.534), in tDCS applied to M1, after five days of intervention. After stimulation, a significant improvement was observed in WHOQoL-Bref Quality of life item 1 (p = 0.04), considering statistical significant difference p 0.05. Correlation between the variables: quality of life, depression, anxiety and pain also demonstrates reduction in depression and anxiety according to Beck’s Depression and Anxiety Inventories (BDI and BAI), p 0.05. This effect was not observed in DLPFC stimulation group. Patients who believed they received active stimulation, in sham group, demonstrated potential for effective blinding. Conclusion: The tDCS applied to primary motor cortex effectively improved pain management and psychiatry symptoms in post-laminectomy syndrome patients. The technique’s low cost, ease of use, and high tolerability make it a promising adjuvant therapy for chronic pain conditions like post-laminectomy syndrome.

Fluid-chemical modeling of the near-cathode sheath formation process in a high current broken in DC air circuit breaker

When the contacts of a medium-voltage DC air circuit breaker(DCCB) are separated, the energy distribution of the arc is determined by the formation process of the near-electrode sheath. Therefore, the voltage drop through the near-electrode sheath is an important means to build up the arc voltage, which directly determines the current-limiting performance of the DCCB. A numerical model to describe the near-electrode sheath formation process can provide insight into the physical mechanism of the arc formation, and thus provide a method for arc energy regulation. In this work, we establish a two-dimensional axisymmetric time-varying model of a medium-voltage DCCB arc when interrupted by high current based on a fluid-chemical model involving 16 kinds of species and 46 collision reactions. The transient distributions of electron number density, positive and negative ion number density, net space charge density, axial electric field, axial potential between electrodes, and near-cathode sheath are obtained from the numerical model. The computational results show that the electron density in the arc column increases, then decreases, and then stabilizes during the near-cathode sheath formation process, and the arc column's diameter gradually becomes wider. The 11.14 V–12.33 V drops along the17 μm space charge layer away from the cathode(65.5 k V/m–72.5 k V/m) when the current varies from 20 k A–80 k A.The homogeneous external magnetic field has little effect on the distribution of particles in the near-cathode sheath core,but the electron number density at the near-cathode sheath periphery can increase as the magnetic field increases and the homogeneous external magnetic field will lead to arc diffusion. The validity of the numerical model can be proven by comparison with the experiment.

Transcranial direct current stimulation efficacy in trigeminal neuralgia

Trigeminal neuralgia is a severe,disabling pain and its deafferentation remains a challenge for health providers.Transcranial direct current stimulation is a non-invasive stimulation technique which finds new utility in managing pain.There-fore,the introduction of alternative,non-invasive,safe,and effective methods should be considered in treating patients with trigeminal neuralgia unresponsive to conventional treatment.

The Effects of the Geometry of a Current Collector with an Equal Open Ratio on Output Power of a Direct Methanol Fuel Cell

The open ratio of a current collector has a great impact on direct methanol fuel cell(DMFC)performance.Although a number of studies have investigated the influence of the open ratio of DMFC current collectors,far too little attention has been given to how geometry(including the shape and feature size of the flow field)affects a current collector with an equal open ratio.In this paper,perforated and parallel current collectors with an equal open ratio of 50%and different feature sizes are designed,and the corresponding experimental results are shown to explain the geometry effects on the output power of the DMFC.The results indicate that the optimal feature sizes are between 2 and 2.5 mm for both perforated and parallel flow field in the current collectors with an equal open ratio of 50%.This means that for passive methanol fuel cells,to achieve the highest output power,the optimal feature size of the flow field in both anode and cathode current collectors is between 2 and 2.5 mm under the operating mode of this experiment.The effects of rib and channel position are also investigated,and the results indicate that the optimum pattern depends on the feature sizes of the flow field.

Effect of transcranial direct current stimulation on supernumerary phantom limb pain in spinal cord injured patient:A case report

BACKGROUND Supernumerary phantom limb(SPL)sensation is the experience of additional limbs,either single or a pair of limbs.Unique to traumatic spinal cord injuries,we report effect of transcranial direct current stimulation(tDCS)on SPL pain in a patient with cervical cord injury.CASE SUMMARY The subject was a 57-year-old man who was diagnosed with complete spinal cord injury(C6/C5,motor level;C5/C5,sensory level;AIS-A)approximately three months ago.After a period of 2 wk,we administered anodal tDCS over the motor cortex for 15 minutes at an intensity of 1.5 mA.Following that treatment,the patient experienced a decrease of SPL pain intensity and frequency,which lasted for 1 week after the end of treatment.CONCLUSION Targeting the motor cortex through neuromodulation appears to be a promising option for the management of SPL pain.

Research and exploration of direct current power supply and distribution systems for Antarctic research stations

The power supply and distribution systems for Antarctic research stations have special characteristics.In light of a worldwide trend toward a gradual increase in the application of renewable energy,an analysis was performed to assess the feasibility of achieving a direct current power supply and distribution at Antarctic research stations by comparing the characteristics of direct current and alternating current electricity.Research was also performed on the status quo and future trends in direct current power supply and distribution systems in Antarctica research stations in combination with case studies.

Transcranial Direct Current Stimulation: Effects on Motor and Non-Motor Symptoms of Parkinson’s Disease

Introduction: In the last thirty years, brain neuromodulation techniques have been used as an alternative to pharmacological treatment of neurological disorders. Parkinson’s disease (PD) is a neurodegenerative disorder leading to bradykinesia, rest tremor, postural changes, and non-motor symptoms such as depression, anxiety, sleep disorders, pain, and cognitive decline that compromises executive functions (EFs), responsible for the orderly execution of behaviors and tasks of daily life and intentional and directed actions. To this date, a few studies with transcranial direct current stimulation (tDCS) have shown beneficial effects in PD patients concerning specific motor and non-motor symptoms, targeting the motor cortex and/or prefrontal regions. Objective: The main objective of this study was to evaluate the effects of left prefrontal tDCS across a broad spectrum of motor and non-motor symptoms of PD using established validated scales. Method: Single-blind randomized clinical trial with 18 volunteers with PD, aged between 45 and 80 years (66.1 ± 9.65), who met inclusion and exclusion criteria. Participants were submitted to assessments of motor and non-motor functions employing psychometric scales and tests to evaluate EFs and were randomly divided into two groups: control (sham stimulation) and experimental (active stimulation). All participants were involved in three separate tDCS sessions. The anode was positioned over the left dorsolateral prefrontal cortex and the cathode over the right supraorbital region, with a direct current intensity of 2 mA, lasting 20 minutes. At the end of the three sessions, all participants were reassessed. Results: Significant effects of tDCS on non-motor functions were observed for cognition (verbal fluency of actions, clock copy test, appointment by visual confrontation, and verbal memory with immediate free recall) and subjective assessment of sleep quality (overall restlessness and discomfort in the arms and legs at night, leg and arm cramps at night and distressing dreams). There was also an improvement in the rate of errors and successes for congruent and incongruent stimuli of the Stroop Test. The beneficial effects on motor function were decreased rigidity, improved gait, and greater agility in the finger-tapping test. Conclusion: Three tDCS sessions showed positive results for participants with PD, producing significant improvements in various motor and non-motor functions, including sleep quality, cognition, and EFs. Additionally, the present results indicate that tDCS neuromodulation of the left dorsolateral prefrontal cortex region is feasible, safe, and provides significant objective benefits for PD patients.

Positive Effect of Transcranial Direct Current Stimulation on Visual Verbal Working Memory in Patients with Attention-Deficit/Hyperactivity Disorder

Background: Working memory is an executive function that plays an important role in many aspects of daily life, and its impairment in patients with attention-deficit/hyperactivity disorder (ADHD) affects quality of life. The dorsolateral prefrontal cortex (DLPFC) has been a good target site for transcranial direct current stimulation (tDCS) due to its intense involvement in working memory. In our 2018 study, tDCS improved visual-verbal working memory in healthy subjects. Objective: This study examines the effects of tDCS on ADHD patients, particularly on verbal working memory. Methods: We conducted an experiment involving verbal working memory of two modalities, visual and auditory, and a sustained attention task that could affect working memory in 9 ADHD patients. Active or sham tDCS was applied to the left DLPFC in a single-blind crossover design. Results: tDCS significantly improved the accuracy of visual-verbal working memory. In contrast, tDCS did not affect auditory-verbal working memory and sustained attention. Conclusion: tDCS to the left DLPFC improved visual-verbal working memory in ADHD patients, with important implications for potential ADHD treatments.

Transcranial direct current stimulation as early augmentation in adolescent obsessive compulsive disorder:A pilot proof-of-concept randomized control trial

BACKGROUND Transcranial direct current stimulation(tDCS)is proven to be safe in treating various neurological conditions in children and adolescents.It is also an effective method in the treatment of OCD in adults.AIM To assess the safety and efficacy of tDCS as an add-on therapy in drug-naive adolescents with OCD.METHODS We studied drug-naïve adolescents with OCD,using a Children’s Yale-Brown obsessive-compulsive scale(CY-BOCS)scale to assess their condition.Both active and sham groups were given fluoxetine,and we applied cathode and anode over the supplementary motor area and deltoid for 20 min in 10 sessions.Reassessment occurred at 2,6,and 12 wk using CY-BOCS.RESULTS Eighteen adolescents completed the study(10-active,8-sham group).CY-BOCS scores from baseline to 12 wk reduced significantly in both groups but change at baseline to 2 wk was significant in the active group only.The mean change at 2 wk was more in the active group(11.8±7.77 vs 5.25±2.22,P=0.056).Adverse effects between the groups were comparable.CONCLUSION tDCS is safe and well tolerated for the treatment of OCD in adolescents.However,there is a need for further studies with a larger sample population to confirm the effectiveness of tDCS as early augmentation in OCD in this population.

Harvesting Environment Mechanical Energy by Direct Current Triboelectric Nanogenerators

As hundreds of millions of distributed devices appear in every corner of our lives for information collection and transmission in big data era,the biggest challenge is the energy supply for these devices and the signal transmission of sensors.Triboelectric nanogenerator(TENG)as a new energy technology meets the increasing demand of today’s distributed energy supply due to its ability to convert the ambient mechanical energy into electric energy.Meanwhile,TENG can also be used as a sensing system.Direct current triboelectric nanogenerator(DC-TENG)can directly supply power to electronic devices without additional rectification.It has been one of the most important developments of TENG in recent years.Herein,we review recent progress in the novel structure designs,working mechanism and corresponding method to improve the output performance for DC-TENGs from the aspect of mechanical rectifier,tribovoltaic effect,phase control,mechanical delay switch and air-discharge.The basic theory of each mode,key merits and potential development are discussed in detail.At last,we provide a guideline for future challenges of DC-TENGs,and a strategy for improving the output performance for commercial applications.

Clay Minerals Channels Identification in the Tindikala-Boutou Area (Eastern-Cameroon) along the Kadey River Using Direct Current (DC) Method

To achieve the current study, geoelectrical surveys along six (06) profiles of 4 km long in a 100 m × 200 m grid defined according to the triangulation principle in the Tindikala-Boutou (Eastern-Cameroon) area along the Kadey River have been made through electrical sounding and profiling following Schlumberger array. The instrument is the resistive meter Syscal Junior 48 (IRIS Instrument). The data have been processed and modelled with Res2Dinv and Winsev softwares, and then interpolated with Surfer software. Investigation method used is the Direct Current (DC) method. Interpretations and analyses of results from the investigation method highlight weak zones or conductive discontinuities. The latter has been identified as shear zones within granitic structures of the Precambrian basement, according to the geologic and tectonic background of the area. The structural trend of these shear zones is E-W approximately. The mineralization characterized by conductive zones proves the presence of clay minerals disseminated in weathered quartz vein, which cross the shear zones. The intense activities of gold washers encountered in the studied area are able to attest the presence of clay minerals concentrations.

Highly Effective Brushless DC Motor in Which Unidirectional Current Flows in

Authors developed a highly effective brushless DC motor with a simple operation principle. If the operation principle of the motor is simple, a drive circuit will also become simple and its production cost will be lower. From the above fact, Minato motor was noticed. In this motor, a unidirectional current flows in the electromagnets. In other words, unidirectional windings are used. In this motor, only strong repulsive force is utilized when a permanent magnet of a rotor and an electromagnet of a stator are adjacent. Hence, torque constant becomes higher and the efficiency of the motor is high. However, an effective value of the electromagnetic current increases because a large current flows in a short period. Therefore, copper loss increases and the efficiency of the motor decreases. In order to solve above defects, a new motor is proposed. From the experiment, it is clarified that the efficiency of the proposed motor is higher than that of the commercial motors.

Effect of Transcranial Direct Current Stimulation of Motor Cortex versus Insula Cortex on Chronic Post-Mastectomy Pain: Randomized Sham-Controlled Trial

Background: Transcranial direct current stimulation (tDCS) across cortical brain areas appears to improve various forms of pain, yet evidence of tDCS efficiency and ideal stimulation target is lacking. This study aimed to compare the add-on analgesic efficacy of concentric electrode transcranial direct current stimulation (CE-tDCS) stimulation over the primary motor cortex versus the insular cortex on the management of chronic postmastectomy pain. Method: Prospective randomized double-blind sham-controlled study enrolled eighty patients with chronic postmastectomy pain that were randomly assigned to four groups: active motor (AM), sham motor (SM), active insula (AI) and sham insula (SI) group, each received 5 sessions for 20-minute duration with 2 mA tDCS over the targeted area of the contralateral side of pain. Our primary outcome was VAS score, the secondary outcomes were VDS score, LANSS score and depression symptoms by HAM-D scores, assessment was done at 4 time points (prestimulation, after 5th session, 15th day and one month after the last session). Results: Both active tDCS groups (motor and insula) showed reduction of VAS (P Conclusion: Active tDCS stimulation either targeting the primary motor cortex or the insula cortex has add-on analgesic effect for controlling neuropathic chronic post mastectomy pain and the maximum effect was at 15 days after the last session.

模块化高压大容量DC/DC变换器综述

随着新能源发电占比增加和电网规模的不断扩大,直流输电系统的容量不断提升,含有不同电压等级的直流电网是未来发展的必然趋势。在此背景下,DC/DC变换器作为直流电网关键设备,在多电压等级互联场景中发挥着重要作用。文中首先对已有的模块化高压大容量DC/DC变换器进行归纳、分类和比较,然后阐述了目前模块化高压大容量DC/DC变换器的拓扑结构、工作原理与特点,并针对其特点提出了不同变换器的适用场景,最后对未来的研究方向提出了建议。

基于双模式变频移相调制的单级式双有源桥型DC-AC变换器

针对单级式双有源桥(DAB)型DC-AC变换器关断电流较大和软开关范围有限的问题,该文提出一种双模式变频移相调制策略。首先,对DAB变换器的单移相(SPS)调制和扩展移相(EPS)调制进行时域分析,得到其功率传输特性;然后,分析变换器的关断电流与软开关条件,得到移相比和开关频率约束方程;在此基础上,分析双模式间的移相比边界条件,提出变换器运行模式的切换机制,从而在实现变换器单级功率变换的同时,保证全范围软开关并降低低压侧的关断电流;最后,通过仿真和实验验证了所提调制策略的有效性与可行性。

固态变压器中隔离双向DC/DC变换器扩展移相下虚拟电流控制策略

该文以固态变压器后级隔离双向DC/DC变换器为重点研究对象,提出一种扩展移相下虚拟电流控制策略。通过分析后级变换器在扩展移相传输功率下相移量关系以获得最小电流应力最优解来提高变换器的传输效率,减少器件损耗。同时通过虚拟电流控制思想在线估算传输功率来提高系统动态响应性能,减少电流传感器使用。最后,对该文所提出的扩展移相下虚拟电流控制与扩展移相控制进行实验对比分析,验证了扩展移相下虚拟电流控制策略具有降低电流应力,显著提高变换器的动态响应的优点。

一种交叉倍压型高增益DC/DC变换器

针对光伏发电、燃料电池发电等领域对高增益直流变换器的需求,以两相交错并联升压变换器为研究对象,由2个含有电感的倍压单元组合设计出实现电压提升的交叉倍压结构,据此提出了一种新颖的交叉倍压型高增益DC/DC变换器。该变换器可实现(3n+4)/(1-d)倍的高电压增益(1∶n为耦合电感匝数比,d为变换器占空比),且具有电路器件的低电压应力特性。对于漏感引起的开关管电压尖峰问题,引入了钳位电容构成释放漏感能量通道,同时提升了输出电压。介绍了新型交叉倍压型高增益变换器的拓扑结构,分析了变换器各模态的工作过程,推导了电压增益、输入电流纹波及各器件电压应力等稳态特性,并搭建样机进行实验研究,验证了该直流变换技术方案的可行性和先进性。

单级三相谐波电流注入可升降压AC/DC变换器

为适应电动车充电电压宽范围变化需求,本文针对传统充电桩前级整流器拓扑开展研究,提出一种新式单级三相AC/DC变换器。该变换器集成了三相桥式不控整流电路与Cuk模块,为降低输入侧电流谐波分量,选用双向开关管构建谐波电流回馈通路,整体构造成单级式拓扑结构。文章阐述了变换器的电路结构及工作模态,通过建立变换器的等效模型推导出电压增益。变换器通过简单的控制逻辑即可实现正弦输入电流并拥有高功率因数。最后通过搭建变换器数字控制实验平台验证了所提变换器的可行性。