Current immunohistochemical techniques have made the identification of microglia possible in routinely processed tissue sections from human brains. Previous studies have indicated that almost no ...neurological diseases exist without microglial activation. Activated microglia often secrete inflammatory cytokines in various diseases, including Alzheimer's disease, but microglial activation is not always associated with inflammation. The equation microglial activation means “neuroinflammation” is absurd and misleading. Neuropathologists are in the best position to provide clarity to end the existing confusion. The functions of microglia in the non‐diseased brain probably include a role in synaptic maintenance, but defects in the expression of specific molecules on microglia can also cause leukoencephalopathy, such as Nasu‐Hakola disease (NHD) and hereditary leukoencephalopathy with spheroids (HDLS). “Microgliopathies” is a new term used to designate conditions where microglial dysfunction is primary and at the center of the disease process. The molecules responsible are DAP12 or TREM2 in NHD and CSF1R in HDLS, respectively, but further studies are needed to clarify how exactly these microglial molecules influence the pathogenesis of axonal and myelin loss. Diffusely infiltrating glial tumors showing microglial differentiation (true microglioma) are exceedingly rare but recent evidence suggests that they indeed exist, although their molecular genetic characterization is still lacking. Participation of the expert neuropathology community will be required to identify additional cases and provide the latter. A large number of tumor‐associated macrophages (TAMs), which are partly derived from microglia, have been observed in glioblastomas. In TAMs, the expression of M2‐like molecules is higher than that of M1‐like molecules, but the number and differentiation state of TAMs vary in the intratumoral area and with the type of macrophage markers used. In future studies, we should focus on the morphological and molecular alterations of the microglia that are specific to the disease where they are observed.
A high-efficiency CMOS rectifier circuit for UHF RFIDs was developed. The rectifier has a cross-coupled bridge configuration and is driven by a differential RF input. A differential-drive active gate ...bias mechanism simultaneously enables both low ON-resistance and small reverse leakage of diode-connected MOS transistors, resulting in large power conversion efficiency (PCE), especially under small RF input power conditions. A test circuit of the proposed differential-drive rectifier was fabricated with 0.18 mu m CMOS technology, and the measured performance was compared with those of other types of rectifiers. Dependence of the PCE on the input RF signal frequency, output loading conditions and transistor sizing was also evaluated. At the single-stage configuration, 67.5% of PCE was achieved under conditions of 953 MHz, - 12.5 dBm RF input and 10 KOmega output load. This is twice as large as that of the state-of-the-art rectifier circuit. The peak PCE increases with a decrease in operation frequency and with an increase in output load resistance. In addition, experimental results show the existence of an optimum transistor size in accordance with the output loading conditions. The multi-stage configuration for larger output DC voltage is also presented.
As a common hazardous waste in metallurgical industry, arsenic-bearing gypsum (ABG) is a great threat to ecological safety. However, the recycle of ABG has rarely been conducted due to its high ...arsenic mobility and worthless constituents. In this study, an ABG was successfully reclaimed as a soil conditioner via acid treatment and Fe(II)As stabilization. Firstly, the arsenic content of ABG was decreased below Japan standard (150 mg/kg) regarding safe materials by acid treatment (H2SO4H3PO4). Then upon heating oxidation, Fe2+ was used to stabilize the arsenic remaining in gypsum sludge at weakly acidic condition (pH 4) via forming insoluble FeAs compounds. In toxicity characteristic leaching procedure (TCLP), the arsenic leaching (0.125 mg/L) from reclaimed gypsum was much lower than TCLP limitation (5 mg/L). And in Japan standard leaching test (JSLT), it was suppressed below the Japan environmental criteria (<10 μg/L), remaining stable for three months upon air exposure. Furthermore, the possible influence factors regarding Fe-ABG stabilization including the destabilizing effects of acid treatment were examined. It showed that the oxidation was necessary for Fe(II)As immobilization. While keeping the weakly acidic condition was crucial important for that of Fe(III). Additionally, acid treatment would make troubles for subsequent FeAs fixation (mainly for Fe 3+). Especially, the introduction of free PO43− or Cl− ions would weaken the stability of insoluble FeAs compounds via forming iron phosphates or iron chloride hydrates and lead to the formation of soluble lollingite (FeAs2), causing arsenic leaching and compromising FeAs stabilization.
•A reclamation method for an arsenic-bearing gypsum (ABG) was proposed.•Treated ABG satisfied the Japan environmental criterion (As leaching < 10 μg/L).•The possible influence factors on Fe-ABG stabilization were examined.•ABG was successfully reused as a soil conditioner without arsenic contamination.
In humans, peripheral sensory stimulation inhibits subsequent motor evoked potentials (MEPs) induced by transcranial magnetic stimulation; this process is referred to as short- or long-latency ...afferent inhibition (SAI or LAI, respectively), depending on the inter-stimulus interval (ISI) length. Although upper limb SAI and LAI have been well studied, lower limb SAI and LAI remain under-investigated. Here, we examined the time course of the soleus (SOL) muscle MEP following electrical tibial nerve (TN) stimulation at the popliteal fossa at ISIs of 20–220 ms. When the conditioning stimulus intensity was three-fold the perceptual threshold, MEP amplitudes were inhibited at an ISI of 220 ms, but not at shorter ISIs. TN stimulation just below the Hoffman (H)-reflex threshold intensity inhibited MEP amplitudes at ISIs of 30, 35, 100, 180 and 200 ms. However, the relationship between MEP inhibition and the P30 latency of somatosensory evoked potentials (SEPs) did not show corresponding ISIs at the SEP P30 latency that maximizes MEP inhibition. To clarify whether the site of afferent-induced MEP inhibition occurs at the cortical or spinal level, we examined the time course of SOL H-reflex following TN stimulation. H-reflex amplitudes were not significantly inhibited at ISIs where MEP inhibition occurred but at an ISI of 120 ms. Our findings indicate that stronger peripheral sensory stimulation is required for lower limb than for upper limb SAI and LAI and that lower limb SAI and LAI are of cortical origin. Moreover, the direct pathway from the periphery to the primary motor cortex may contribute to lower limb SAI.
Emotion affects postural control during quiet standing. Emotional states can be defined as two-dimensional models comprising valence (pleasant/unpleasant) and arousal (aroused/calm). Most previous ...studies have investigated the effects of valence on postural control without considering arousal. In addition, studies have focused on the center of pressure (COP) trajectory to examine emotional effects on the quiet standing control; however, the relationship between neuromuscular mechanisms and the emotionally affected quiet standing control is largely unknown. This study aimed to investigate the effects of arousal and valence on the COP trajectory and ankle muscle activity during quiet standing. Twenty-two participants were instructed to stand on a force platform and look at affective pictures for 72 seconds. The tasks were repeated six times, according to the picture conditions composed of arousal (High and Low) and valence (Pleasant, Neutral, and Unpleasant). During the task, the COP, electromyogram (EMG) of the tibialis anterior and soleus muscles, and electrocardiogram (ECG) were recorded. The heart rate calculated from the ECG was significantly affected by valence; the value was lower in Unpleasant than that in Neutral and Pleasant. The 95% confidence ellipse area and standard deviation of COP in the anterior-posterior direction were lower, and the mean power frequency of COP in the anterior-posterior direction was higher in Unpleasant than in Pleasant. Although the mean velocity of the COP in the medio-lateral direction was significantly lower in Unpleasant than in Pleasant, the effect was observed only when arousal was low. Although the EMG variables were not significantly affected by emotional conditions, some EMG variables were significantly correlated with the COP variables that were affected by emotional conditions. Therefore, ankle muscle activity may be partially associated with postural changes triggered by emotional intervention. In conclusion, both valence and arousal affect the COP variables, and ankle muscle activity may be partially associated with these COP changes.
Pain is caused by tissue injury, inflammatory disease, pathogen invasion, or neuropathy. The perception of pain is attributed to the neuronal activity in the brain. However, the dynamics of neuronal ...activity underlying pain perception are not fully known. Herein, we examined theta-oscillation dynamics of local field potentials in the primary somatosensory cortex of a mouse model of formalin-induced pain, which usually shows a bimodal behavioral response interposed between pain-free periods. We found that formalin injection exerted a reversible shift in the theta-peak frequency toward a slower frequency. This shift was observed during nociceptive phases but not during the pain-free period and was inversely correlated with instantaneous pain intensity. Furthermore, instantaneous oscillatory analysis indicated that the probability of slow theta oscillations increased during nociceptive phases with an association of augmented slow theta power. Finally, cross-frequency coupling between theta and gamma oscillations indicated that the coupling peak frequency of theta oscillations was also shifted toward slower oscillations without affecting coupling strength or gamma power. Together, these results suggest that the dynamic changes in theta oscillations in the mouse primary somatosensory cortex represent the ongoing status of pain sensation.
As one of the biggest hazardous solid waste in the metallurgical industry, arsenic-bearing gypsum (ABG) is a great threat to environmental safety owing to possible leakage and diffusion ...contamination. However, the reclamation of ABG suffers great challenges due to its worthless constituents and high arsenic leaching. In this study, an ABG was reclaimed as more valuable bassanite (CaSO4∙0.5H2O) and anhydrite (CaSO4). Firstly, the overmuch arsenic in ABG was removed to below 150 mg/kg (Japan standard value) using acid extraction. Then, the sludge was mixed with a small amount of CaO and heated at 150 °C and 900 °C to produce bassanite and anhydrite, respectively. In this calcination, gypsum dehydration and arsenic stabilization were combined. In Japan standard leaching test (JSLT), the arsenic leaching concentrations from bassanite (5.1 μg/L) and anhydrite (1.3 μg/L) satisfied the environmental criteria (<10 μg/L) set by Japan government and remained stable for three months. In toxicity characteristic leaching procedure (TCLP), arsenic leaching concentrations remained at 1.61 and 0.61 mg/L, much lower than the limitation (<5 mg/L). Moreover, the arsenic leaching behavior implied that higher temperature was benefited to arsenic stability, which indicated that the arsenic stabilization process was temperature dependent. By XRD analyses, it was found that heating (over 100 °C) could effectively promote arsenic immobilization through reducing the carbonation influence. And the temperature dependence was attributed to the formation of insoluble svabite (Ca5(AsO4)3OH) at high temperature (300–900 °C).
•An As-bearing gypsum was disposed by acid washing and CaO-As stabilization.•As stabilization and gypsum dehydration were combined in thermal treatment.•CaO-As fixation was temperature dependent owing to the formation of svabite.•The As-bearing gypsum was reclaimed as bassanite and anhydrite.•Final products satisfied the Japan environmental criterion (As leaching < 10 μg/L).
Transcutaneous and epidural electrical spinal cord stimulation techniques are becoming more valuable as electrophysiological and clinical tools. Recently, remarkable recovery of the upper limb ...sensorimotor function during cervical spinal stimulation was demonstrated. In the present study, we sought to elucidate the neural mechanisms underlying the effects of transcutaneous spinal cord stimulation (tSCS) of the cervical spine. We hypothesized that cervical tSCS can be used to selectively activate the sensory route entering the spinal cord and transsynaptically converge on upper limb motor pools. To test this hypothesis, we applied cervical tSCS using paired stimuli (homosynaptic depression) and during passive muscle stretching of the wrist flexor (presynaptic inhibition via Ia afferents), voluntary hand muscle contraction (descending facilitation of motoneuron pool), and muscle-tendon vibration of the wrist (presynaptic inhibition via afferent occlusion). Our results demonstrate significant inhibition of the second evoked response during paired stimulus delivery, inhibition of responses during passive muscle stretching and muscle-tendon vibration, and facilitation during voluntary muscle contraction, which share similarities with responses evoked during lumbosacral tSCS. These results indicate that the route of the stimulation current transmission passes via afferents in the dorsal roots through the spinal cord to activate the motor pools and potentially interneuronal networks projecting to upper limb muscles. Using a novel stimulation paradigm, our study is the first to present evidence of the sensory neuronal pathway of the cervical tSCS propagation. Overall, our work demonstrates the utility and sensitivity of cervical tSCS to engage the sensory pathway projecting to the upper limbs.
Despite therapeutic effects that have been demonstrated previously using noninvasive cervical spinal stimulation, it has been unclear whether, and to what degree, the stimulation can activate the sensory afferent system. Our study presents evidence that cervical transcutaneous spinal cord stimulation can engage the sensory pathways and transsynaptically converge on motor pools projecting to upper limb muscles, demonstrating the utility and sensitivity of cervical spinal stimulation for electrophysiological assessments and neurorehabilitation.
•Upper-limb muscle contractions facilitated corticospinal, but not subcortical neural circuits of the remote trunk muscles.•Trunk muscle contractions facilitated both corticospinal and subcortical ...neural circuits of the remote upper-limb muscles.•Corticospinal neurons may have complex outputs to multiple muscles which interact within cortical and spinal circuits.
Activities of daily living require simultaneous and coordinated activation of trunk and upper-limb segments, which involves complex interlimb interaction within the central nervous system. Although many studies have reported associations between activity of trunk and limb muscles during functional tasks, evidence on cortical and subcortical contributions to trunk-limb neural interactions is still not fully clear. Therefore, the aim of this study was to examine interactions between trunk and upper-limb muscles in the: (i) corticospinal circuits by using motor evoked potential (MEP) elicited through transcranial magnetic stimulation; and (ii) subcortical circuits by using cervicomedullary motor evoked potential (CMEP) elicited through cervicomedullary junction magnetic stimulation. Responses were evoked in the erector spinae (trunk) and flexor carpi radialis (upper-limb) muscles in twelve able-bodied individuals: (1) while participants were relaxed; (2) during trunk muscle contractions while arms were at rest; and (3) during upper-limb muscle contractions while the trunk was at rest. Our results showed that trunk muscle CMEP responses were not affected by upper-limb muscle contractions, while MEP responses were modulated. This indicates that at least the subcortical circuits may not attribute to facilitation of the trunk muscles during upper-limb contractions. On the other hand, in the upper-limb muscles, both CMEP and MEP responses were modulated during trunk contractions. These results indicate that cortical and subcortical mechanisms attributed to facilitation of upper-limb muscles during trunk contractions. In conclusion, our study demonstrated evidence that trunk-limb neural interactions may be attributed to cortical and/or subcortical mechanisms depending on the contracted muscle.
Muscle synergy analysis is useful for investigating trunk coordination patterns based on the assumption that the central nervous system reduces the dimensionality of muscle activation to simplify ...movement. This study aimed to quantify the variability in trunk muscle synergy during various trunk motor tasks in healthy participants to provide reference data for evaluating trunk control strategies in patients and athletes. Sixteen healthy individuals performed 11 trunk movement and stability tasks with electromyography (EMG) recording of their spinal and abdominal muscles (6 bilaterally). Non-negative matrix factorization applied to the concatenated EMG of all tasks identified the five trunk muscle synergies (W) with their corresponding temporal patterns (C). The medians of within-cluster similarity defined by scalar products in W and r
coefficient using the cross-correlation function in C were 0.73-0.86 and 0.64-0.75, respectively, while the inter-session similarities were 0.81-0.96 and 0.74-0.84, respectively. However, the lowest and highest values of both similarity indices were broad, reflecting the musculoskeletal system's redundancy within and between participants. Furthermore, the significant differences in the degree of variability between the trunk synergies may represent the different neural features of synergy organization and strategies to overcome the various mechanical demands of a motor task.
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