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Abstract Background Nociception requires transduction and impulse electrogenesis in nerve fibers which innervate the body surface, including the skin. However, the molecular substrates for transduction and action potential initiation in nociceptors are incompletely understood. In this study, we examined the expression and distribution of Na+/Ca2+ exchanger (NCX) and voltage-gated sodium channel isoforms in intra-epidermal free nerve terminals. Results Small diameter DRG neurons exhibited robust NCX2, but not NCX1 or NCX3 immunolabeling, and virtually all PGP 9.5-positive intra-epidermal free nerve terminals displayed NCX2 immunoreactivity. Sodium channel NaV1.1 was not detectable in free nerve endings. In contrast, the majority of nerve terminals displayed detectable levels of expression of NaV1.6, NaV1.7, NaV1.8 and NaV1.9. Sodium channel immunoreactivity in the free nerve endings extended from the dermal boundary to the terminal tip. A similar pattern of NCX and sodium channel immunolabeling was observed in DRG neurons in vitro. Conclusions NCX2, as well as NaV1.6, NaV1.7, NaV1.8 and NaV1.9, are present in most intra-epidermal free nerve endings. The presence of NCX2, together with multiple sodium channel isoforms, in free nerve endings may have important functional implications.

Abstract Background Two groups of gain-of-function mutations in sodium channel NaV1.7, which are expressed in dorsal root ganglion (DRG) neurons, produce two clinically-distinct pain syndromes - inherited erythromelalgia (IEM) and paroxysmal extreme pain disorder (PEPD). IEM is characterized by intermittent burning pain and skin redness in the feet or hands, triggered by warmth or mild exercise, while PEPD is characterized by episodes of rectal, ocular and mandibular pain accompanied with skin flushing, triggered by bowel movement and perianal stimulation. Most of the IEM mutations are located within channel domains I and II, while most of the PEPD mutations are located within domains III and IV. The structural dichotomy parallels the biophysical effects of the two types of mutations, with IEM mutations shifting voltage-dependence of NaV1.7 activation in a hyperpolarized direction, and PEPD mutations shifting fast-inactivation of NaV1.7 in a depolarized direction. While four IEM and four PEPD mutations are located within cytoplasmic linkers joining segments 4 and 5 (S4-S5 linkers) in the different domains (IEM: domains I and II; PEPD: domains III and IV), no S4-S5 linker has been reported to house both IEM and PEPD mutations thus far. Results We have identified a new IEM mutation P1308L within the C-terminus of the DIII/S4-S5 linker of NaV1.7, ten amino acids from a known PEPD mutation V1298F which is located within the N-terminus of this linker. We used voltage-clamp to compare the biophysical properties of the two mutant channels and current-clamp to study their effects on DRG neuron excitability. We confirm that P1308L and V1298F behave as prototypical IEM and PEPD mutations, respectively. We also show that DRG neurons expressing either P1308L or V1298F become hyperexcitable, compared to DRG neurons expressing wild-type channels. Conclusions Our results provide evidence for differential roles of the DIII/S4-S5 linker N- and C-termini in channel inactivation and activation, and demonstrate the cellular basis for pain in patients carrying these mutations.

Abstract Background Primary erythromelalgia is an autosomal dominant pain disorder characterized by burning pain and skin redness in the extremities, with onset of symptoms during the first decade in the families whose mutations have been physiologically studied to date. Several mutations of voltage-gated Na+ channel NaV1.7 have been linked with primary erythromelalgia. Recently, a new substitution NaV1.7/I136V has been reported in a Taiwanese family, in which pain appeared at later ages (9–22 years, with onset at 17 years of age or later in 5 of 7 family members), with relatively slow progression (8–10 years) to involvement of the hands. The proband reported onset of symptoms first in his feet at the age of 11, which then progressed to his hands at the age of 19. The new mutation is located in transmembrane segment 1 (S1) of domain I (DI) in contrast to all NaV1.7 mutations reported to date, which have been localized in the voltage sensor S4, the linker joining segments S4 and S5 or pore-lining segments S5 and S6 in DI, II and III. Results In this study, we characterized the gating and kinetic properties of I136V mutant channels in HEK293 cells using whole-cell patch clamp. I136V shifts the voltage-dependence of activation by -5.7 mV, a smaller shift in activation than the other erythromelalgia mutations that have been characterized. I136V also decreases the deactivation rate, and generates larger ramp currents. Conclusion The I136V substitution in NaV1.7 alters channel gating and kinetic properties. Each of these changes may contribute to increased excitability of nociceptive dorsal root ganglion neurons, which underlies pain in erythromelalgia. The smaller shift in voltage-dependence of activation of NaV1.7, compared to the other reported cases of inherited erythromelalgia, may contribute to the later age of onset and slower progression of the symptoms reported in association with this mutation.

Biomass carbon has the advantages of wide source, low cost and environmental protection, and has been widely used in the field of electrochemical energy storage. In this work, N and S co‐doped carbon materials were prepared by using peanut shell as carbon source and thiourea as activator. When the peanut shell and activator were 2 g and 4 g, respectively, the prepared NSPC‐4 had the largest specific surface area and special pore structure. Elemental analysis showed that the activator introduced more N, S and O atoms to the carbon material, and more heteroatoms helped to improve the surface structure of the carbon material and provide additional pseudocapacitance. In addition, NSPC‐4 contains a short‐range ordered graphite structure, which can provide excellent electrical conductivity. The electrochemical test results show that NSPC‐4 has the largest specific capacitance. When the mass of the activator is higher than or below 4 g, the electrochemical performance of the carbon material will be reduced. The symmetric supercapacitor (SSC) assembled by NSPC‐4 has an energy density of 8.3 Wh kg−1 when the power density is 350 W kg−1. The synthesis method is not only simple, green and economical, but also has important application value. [ABSTRACT FROM AUTHOR]

In order to improve the electrochemical performance of NiCo‐based layered double hydroxide (NiCoLDH), the synthesis of low‐crystallinity NiCoLDH was induced by the adsorption of glucose and NiCoLDH. The results showed that glucose could not only effectively regulate the pore structure and morphology of NiCoLDH, but also had a regular effect on crystallinity. Pure phase NiCoLDH had higher crystallinity. When the mass of glucose is 0.05 g, the prepared NiCoLDH‐0.05 is a short‐range ordered structure embedded in the amorphous matrix. The crystallinity of the product decreases further with the further increase of glucose mass. Since the ordered structures have higher electrical conductivity, and amorphous structures have more defects and active sites, the structure of NiCoLDH‐0.05 is conducive to achieving the best electrochemical performance. Electrochemical test results show that NiCoLDH‐0.05 has a high specific capacitance, about 12 times that of the pure phase NiCoLDH, the mass of glucose is higher than or below 0.05 g, the specific capacitance will be further reduced. NiCoLDH‐0.05 and activated carbon assembled into an asymmetric supercapacitor have a power density of 400 W kg−1 at an energy density of 32.7 Wh kg−1. This study provides a new idea for obtaining excellent electrochemical properties by adjusting LDH crystallinity. [ABSTRACT FROM AUTHOR]

The composite α-Ni(OH)2@CNT of multi-walled carbon nanotubes (CNT) and sheet-like α-Ni(OH)2 was prepared by a one-step hydrothermal method. The structures and electrochemical properties of α-Ni(OH)2@CNT and α-Ni(OH)2 have been studied in detail. Since hydroxylated CNT was used in this study, CNT provides the dual role of dispersion and conductivity for α-Ni(OH)2@CNT. The structural characterization shows that the thickness of α-Ni(OH)2@CNT nanosheets is significantly lower than that of α-Ni(OH)2, and the specific surface area and pore volume are significantly higher than that of α-Ni(OH)2, which provides more active sites for the composites. The electrochemical test results show that the specific capacitance and rate performance of α-Ni(OH)2@CNT are much higher than that of α-Ni(OH)2. The asymmetric supercapacitor (ASC) assembled with α-Ni(OH)2@CNT and activated carbon (AC) can provide an energy density of 42.8 Wh kg−1 at a power density of 800 W kg−1, and the specific capacity can be maintained by 80% after 20,000 cycles, showing good application value. The theoretical calculation results further confirm that CNT increases the conductivity of α-Ni(OH)2@CNT. This work provides a low cost and effective modification method for the practical application of α-Ni(OH)2. [ABSTRACT FROM AUTHOR]

The similarities and differences between nervous systems of various species result from developmental constraints and specific adaptations.sup.1-4. Comparative analyses of the prefrontal cortex (PFC), a cerebral cortex region involved in higher-order cognition and complex social behaviours, have identified true and potential human-specific structural and molecular specializations.sup.4-8, such as an exaggerated PFC-enriched anterior-posterior dendritic spine density gradient.sup.5. These changes are probably mediated by divergence in spatiotemporal gene regulation.sup.9-17, which is particularly prominent in the midfetal human cortex.sup.15,18-20. Here we analysed human and macaque transcriptomic data.sup.15,20 and identified a transient PFC-enriched and laminar-specific upregulation of cerebellin 2 (CBLN2), a neurexin (NRXN) and glutamate receptor-[delta] GRID/GluD-associated synaptic organizer.sup.21-27, during midfetal development that coincided with the initiation of synaptogenesis. Moreover, we found that species differences in level of expression and laminar distribution of CBLN2 are, at least in part, due to Hominini-specific deletions containing SOX5-binding sites within a retinoic acid-responsive CBLN2 enhancer. In situ genetic humanization of the mouse Cbln2 enhancer drives increased and ectopic laminar Cbln2 expression and promotes PFC dendritic spine formation. These findings suggest a genetic and molecular basis for the anterior-posterior cortical gradient and disproportionate increase in the Hominini PFC of dendritic spines and a developmental mechanism that may link dysfunction of the NRXN-GRID-CBLN2 complex to the pathogenesis of neuropsychiatric disorders. The authors identify deletions in a retinoic acid signalling responsive genetic element that leads to disproportionate increase of dendritic spines on neurons of the human prefrontal cortex., Author(s): Mikihito Shibata [sup.1] , Kartik Pattabiraman [sup.1] [sup.2] , Sydney K. Muchnik [sup.1] [sup.3] , Navjot Kaur [sup.1] , Yury M. Morozov [sup.1] , Xiaoyang Cheng [sup.4] [sup.5] [sup.6] [...]

Vincristine-induced peripheral neuropathy is a common side effect of vincristine treatment, which is accompanied by pain and can be dose-limiting. The molecular mechanisms that underlie vincristine-induced pain are not well understood. We have established an animal model to investigate pathophysiological mechanisms of vincristine-induced pain. Our previous studies have shown that the tetrodotoxin-sensitive voltage-gated sodium channel Nav1.6 in medium-diameter dorsal root ganglion (DRG) neurons contributes to the maintenance of vincristine-induced allodynia. In this study, we investigated the effects of vincristine administration on excitability in small-diameter DRG neurons and whether the tetrodotoxin-resistant (TTX-R) Nav1.8 channels contribute to mechanical allodynia. Current-clamp recordings demonstrated that small DRG neurons become hyper-excitable following vincristine treatment, with both reduced current threshold and increased firing frequency. Using voltage-clamp recordings in small DRG neurons, we now show an increase in TTX-R current density and a −7.3 mV hyperpolarizing shift in the half-maximal potential (V1/2) of activation of Nav1.8 channels in vincristine-treated animals, which likely contributes to the hyperexcitability that we observed in these neurons. Notably, vincristine treatment did not enhance excitability of small DRG neurons from Nav1.8 knockout mice, and the development of mechanical allodynia was delayed but not abrogated in these mice. Together, our data suggest that sodium channel Nav1.8 in small DRG neurons contributes to the development of vincristine-induced mechanical allodynia. [ABSTRACT FROM AUTHOR]

Mine gas accidents have received widespread attention at home and abroad, because mine gas accidents often cause casualties and property losses once they occur. This study was conducted in order to have a more comprehensive understanding of the research status of and research hotspots in coal mine gas management at home and abroad, and to provide references for relevant researchers' studies and literature searches. Using the Web of Science (WOS) core database as the data source, this paper analyzed the data from the period of 2000–2023 under the headings of "gas governance", "Gas Control Technology", "Pre-mining gas methods in coal mines", "Methods of Gas Mining in Coal Mines", "Post-mining gas", and "Post-mining gas methods in coal mines". "Methods in Coal Mines", "Methods of Gas Mining in Coal Mines", and "Post-mining Gas Methods in Coal Mines" were searched, and the CiteSpace tool was utilized to provide a multi-dimensional visual presentation of the literature, including authors, the number of journals issued, countries of issue, keywords, etc., in order to explore the research hotspots in this field. The analysis results show the following: the development process in the field of gas prevention and control is mainly divided into the three stages of initial exploration, steady development, and explosive surge; China, Australia, and the United States are the top three countries in terms of the number of articles published, and they have a greater influence in the field, but there is a closer connection between the regions in Europe; a certain group size has been formed by the researchers and research institutes in this field, the China University of Mining and Technology is more active in this field, ranking as the first in terms of the number of articles issued, and it has a cooperative relationship with many universities; Kai Wang and Enyuan Wang are the core authors in this field, while C. Ozgen Karacan also has a large body of research in the field, and his research results are widely recognized; the main journals issued in this field are Fuel and Energy Policy, while other journals have been frequently cited, and these journals have an important role in the field. In these journals, "Coal mine methane: A review of capture and utilization practices with benefits to mining safety and to greenhouse gas reduction" is one of the most important articles in the field. Thin coal seams, coal mining workings, and coal and gas protrusion are current research hotspots. [ABSTRACT FROM AUTHOR]

This paper describes a study on speaker recognition using the ECAPA-TDNN architecture, which stands for Extended Context-Aware Parallel Aggregations Time-Delay Neural Network. It utilizes X-vectors, a method for extracting speaker features by converting speech into fixed-length vectors, and introduces a squeeze-and-excitation block to model dependencies between channels. In order to better explore temporal relationships in the context of speaker recognition and improve the algorithm's generalization performance in complex acoustic scenarios, this study adds input gates and forget gates to the ECAPA-TDNN architecture, combining them with CIFG (Convolutional LSTM with Input and Forget Gates) modules. These are embedded into a residual structure of multi-layer aggregated features. A sub-center Arcface, an improved loss function based on Arcface, is used for selecting sub-centers for subclass discrimination, retaining advantageous sub-centers to enhance intra-class compactness and strengthen the robustness of the network. Experimental results demonstrate that the improved ECAPA-TDNN-CIFG in this study outperforms the baseline model, yielding more accurate and efficient recognition results. [ABSTRACT FROM AUTHOR]

Proton exchange membrane fuel cells (PEMFCs) and alkaline membrane fuel cells (AEMFCs) have received great attention as energy devices of the next generation. Accelerating oxygen reduction reaction (ORR) kinetics is the key to improve PEMFC and AEMFC performance. Platinum‐based catalysts are the most widely used catalysts for the ORR, but their high price and low abundance limit the commercialization of fuel cells. Non‐noble metal‐nitrogen‐carbon (M−N−C) is considered to be the most likely material class to replace Pt‐based catalysts, among which Fe−N−C and Co−N−C have been widely studied due to their excellent intrinsic ORR performance and have made great progress in the past decades. With the improvement of synthesis technology and a deeper understanding of the ORR mechanism, some reported Fe−N−C and Co−N−C catalysts have shown excellent ORR activity close to that of commercial Pt/C catalysts. Inspired by the progress, regulation strategies for Fe−N−C and Co−N−C catalysts are summarized in this Review from 5 perspectives: (1) coordinated atoms, (2) environmental heteroatoms and defects, (3) dual‐metal active sites, (4) metal‐based particle promoters, and (5) curved carbon layers. We also make suggestions on some challenges facing Fe−N−C and Co−N−C research. [ABSTRACT FROM AUTHOR]

The single‐atom Fe−N−C is a prominent material with exceptional reactivity in areas of sustainable energy and catalysis research. It is challenging to obtain the dense Fe‐N4 site without the Fe nanoparticles (NPs) sintering during the Fe−N−C synthesis via high‐temperature pyrolysis. Thus, a novel approach is devised for the Fe−N−C synthesis at low temperatures. Taking FeCl2 as Fe source, a hydrogen environment can facilitate oxygen removal and dichlorination processes in the synthesis, efficiently favouring Fe‐N4 site formation without Fe NPs clustering at as low as 360 °C. We shed light on the reaction mechanism about hydrogen promoting Fe‐N4 formation in the synthesis. By adjusting the temperature and duration, the Fe‐N4 structural evolution and site density can be precisely tuned to directly influence the catalytic behaviour of the Fe−N−C material. The FeNC‐H2‐360 catalyst demonstrates a remarkable Fe dispersion (8.3 wt %) and superior acid ORR activity with a half‐wave potential of 0.85 V and a peak power density of 1.21 W cm−2 in fuel cell. This method also generally facilitates the synthesis of various high‐performance M−N−C materials (M=Fe, Co, Mn, Ni, Zn, Ru) with elevated single‐atom loadings. [ABSTRACT FROM AUTHOR]

Iron‐nitrogen‐carbon (Fe‐N‐C) catalysts for the oxygen reduction reaction (ORR) in proton exchange membrane fuel cells (PEMFCs) have seriously been hindered by their poor ORR performance of Fe‐N‐C due to the low active site density (SD) and site utilization. Herein, we reported a melamine‐assisted vapor deposition approach to overcome these hindrances. The melamine not only compensates for the loss of nitrogen caused by high‐temperature pyrolysis but also effectively etches the carbon substrate, increasing the external surface area and mesoporous porosity of the carbon substrate. These can provide more useful area for subsequent vapor deposition on active sites. The prepared 0.20Mela‐FeNC catalyst shows a fourfold higher SD value and site utilization than the FeNC without the treatment of melamine. As a result, 0.20Mela‐FeNC catalyst exhibits a high ORR activity with a half‐wave potential (E1/2) of 0.861 V and 12‐fold higher ORR mass activity than the FeNC in acidic media. As the cathode in a H2‐O2 PEMFCs, 0.20Mela‐FeNC catalyst demonstrates a high peak power density of 1.30 W cm−2, outstripping most of the reported Fe‐N‐C catalysts. The developed melamine‐assisted vapor deposition approach for boosting the SD and utilization of Fe‐N‐C catalysts offers a new insight into high‐performance ORR electrocatalysts. [ABSTRACT FROM AUTHOR]

Since the major of information security was established in 2001, the knowledge and ability system of cyber security talents to meet demands of the society and the corresponding talent cultivating mode have always been concerned. Based on the social requirements, the basic knowledge and ability requirements of cyber security talents were analyzed, and consequently regard inter-disciplinary talents as an important demand of cyber security industry. Taking as an example the double degree class of information security and law of Nankai university, the cultivating mode of inter-disciplinary talents of information security and law was introduced, in order to provide reference for the construction of China's cyber security talent cultivating mode.