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Abstract Spinal cord injury (SCI) leads to fibrotic scar formation at the lesion site, yet the heterogeneity of fibrotic scar remains elusive. Here we show the heterogeneity in distribution, origin, and function of fibroblasts within fibrotic scars after SCI in mice and female monkeys. Utilizing lineage tracing and single-cell RNA sequencing (scRNA-seq), we found that perivascular fibroblasts (PFs), and meningeal fibroblasts (MFs), rather than pericytes/vascular smooth cells (vSMCs), primarily contribute to fibrotic scar in both transection and crush SCI. Crabp2 + /Emb+ fibroblasts (CE-F) derived from meninges primarily localize in the central region of fibrotic scars, demonstrating enhanced cholesterol synthesis and secretion of type I collagen and fibronectin. In contrast, perivascular/pial Lama1 + /Lama2+ fibroblasts (LA-F) are predominantly found at the periphery of the lesion, expressing laminin and type IV collagen and functionally involved in angiogenesis and lipid transport. These findings may provide a comprehensive understanding for remodeling heterogeneous fibrotic scars after SCI.

Two-way FDI indicates that China's technological catch-up process has entered a new stage. Mechanisms and conditions through which two-way FDI affects technological innovation require urgent attention. Based on China's provincial panel data, by using 2SLS tests, negative binomial model, and GMM estimation, this study finds that two-way FDI has a significant promoting effect on technological innovation, absorptive capacity has a positive moderating effect on the relationship between two-way FDI and technological innovation, and IPR protection has a negative moderating effect on the relationship between two-way FDI and technological innovation. The heterogeneity test shows that the interaction effect of IFDI, OFDI, and the moderating effect of absorptive capacity increase with the regional economic development and the passage of time. In contrast, the negative moderating effect of IPR protection decreases. This study contributes to the understanding of the two-way FDI at play in the technological innovation of emerging markets. It emphasises the promoting and restricting factors of two-way FDI in this process.

Abstract Spinal cord injury (SCI) leads to severe sensory and motor dysfunction below the lesion. However, the cellular dynamic responses and heterogeneity across different regions below the lesion remain to be elusive. Here, we used single-cell transcriptomics to investigate the region-related cellular responses in female rhesus monkeys with complete thoracic SCI from acute to chronic phases. We found that distal lumbar tissue cells were severely impacted, leading to degenerative microenvironments characterized by disease-associated microglia and oligodendrocytes activation alongside increased inhibitory interneurons proportion following SCI. By implanting scaffold into the injury sites, we could improve the injury microenvironment through glial cells and fibroblast regulation while remodeling spared lumbar tissues via reduced inhibitory neurons proportion and improved phagocytosis and myelination. Our findings offer crucial pathological insights into the spared distal tissues and proximal tissues after SCI, emphasizing the importance of scaffold-based treatment approaches targeting heterogeneous microenvironments.

A 3D symmetric memristor-based chaotic system (SMCS) is constructed by introducing a smooth quadratic flux control memristor model into the jerk chaotic system (JCS). The dynamics of SMCS are investigated by means of Lyapunov exponents, bifurcation diagrams, multistability, transient behavior, and spectral entropy complexity. It is found that SMCS is sensitive to parameter b included in the normalized equation. Transition behaviors of coexisting attractors between the equilibrium points will be observed when parameter b changes in a specific interval. Its complexity is demonstrated by the types of three multi-stable behaviors and four types of transient behaviors and distinctly enhanced by the spectral entropy complexity as two parameters variations. Additionally, the physical realizability of SMCS is verified by the implementation of the analog circuit and digital hardware. Finally, the pseudo-random sequence based on JCS and SCMS is compared by NIST testing.

Neural stem progenitor cell (NSPC) transplantation has been regarded as a promising therapeutic method for spinal cord injury (SCI) repair. However, different NSPCs may have different therapeutic effects, and it is therefore important to identify the optimal NSPC type. In our study, we compared the transcriptomes of human fetal brain-derived NSPCs (BNSPCs), spinal cord-derived NSPCs (SCNSPCs) and H9 embryonic stem-cell derived NSPCs (H9–NSPCs) in vitro and subsequently we transplanted each NSPC type on a collagen scaffold into a T8-9 complete SCI rat model in vivo. In vitro data showed that SCNSPCs had more highly expressed genes involved in nerve-related functions than the other two cell types. In vivo, compared with BNSPCs and H9–NSPCs, SCNSPCs exhibited the best therapeutic effects; in fact, SCNSPCs facilitated electrophysiological and hindlimb functional recovery. This study demonstrates that SCNSPCs may be an appropriate candidate cell type for SCI repair, which is of great clinical significance.

This paper reports a new fractional-order Chua’s system with arctan function and an algorithm for determining the initial value of fractional-order hidden attractors. Firstly, dynamics of the system is investigated by employing the stability analysis, dissipativeness, phase diagrams, 0-1 test, bifurcation diagram and SampEn complexity measure. It shows rich dynamics in the proposed system. Secondly, using the proposed algorithm, the initial values of the new fractional-order Chua’s system are calculated. And according to two sets of initial conditions, hidden attractors are found and verified by the numerical simulation. Meanwhile, the basin attraction is analyzed to confirm that the hidden attractor is indeed not near the fixed point. Thirdly, the new fractional-order Chua’s system is implemented on the DSP platform, and the arctan function’s processing algorithm is proposed. The DSP experimental results show that the system can produce a pair of coexisting fractional-order hidden attractors, and the experimental results are consistent with the numerical simulation results. It verifies the effectiveness of the presented methods and shows the potential engineering application value of the proposed Chua’s system.

Summary: Syringomyelia is a common clinical lesion associated with cerebrospinal fluid flow abnormalities. By a reversible model with chronic extradural compression to mimic human canalicular syringomyelia, we explored the spatiotemporal pathological alterations during syrinx development. The most dynamic alterations were observed in ependymal cells (EPCs), oligodendrocyte lineage, and microglia, as a response to neuroinflammation. Among different cell types, EPC subtypes experienced obvious dynamic alterations, which were accompanied by ultrastructural changes involving the ependymal cytoskeleton, cilia, and dynamic injury in parenchyma primarily around the central canal, corresponding to the single-cell transcripts. After effective decompression, the syrinx resolved with the recovery of pathological damage and overall neurological function, implying that for syringomyelia in the early stage, there was still endogenous repair potential coexisting with immune microenvironment imbalance. Ependymal remodeling and cilia restoration might be important for better resolution of syringomyelia and parenchymal injury recovery.

Abstract Neural progenitor cell (NPC) transplantation is a promising approach for repairing spinal cord injury (SCI). However, cell survival, maturation and integration after transplantation are still major challenges. Here, we produced a novel centimeter‐scale human spinal cord neural tissue (hscNT) construct with human spinal cord neural progenitor cells (hscNPCs) and human spinal cord astrocytes (hscAS) on a linearly ordered collagen scaffold (LOCS). The hscAS promoted hscNPC adhesion, survival and neurite outgrowth on the LOCS, to form a linearly ordered spinal cord‐like structure consisting of mature neurons and glia cells. When transplanted into rats with SCI, the hscNT created a favorable microenvironment by inhibiting inflammation and glial scar formation, and promoted neural and vascular regeneration. Notably, the hscNT promoted neural circuit reconstruction and motor functional recovery. Engineered human spinal cord implants containing astrocytes and neurons assembled on axon guidance scaffolds may therefore have potential in the treatment of SCI.

Abstract Discrete chaotic system has complex dynamics and becomes to be a present hot topic, but its analogue circuit implementation is rarely discussed. In this paper, by simplifying the logistic map, a new Logistic‐like map is proposed. Its cobweb plots, bifurcations, Lyapunov exponents, and dynamic map are investigated theoretically and numerically. The results show that the Logistic‐like map has complex dynamical behaviours. And then Psim simulation model is proposed to verify the feasibility of analogue circuit implementation. Finally, an analogue circuit experiment is performed and its results are consistent with the simulation results. The circuit designed is very simple and has less components, which can further broaden the applications of discrete chaotic map in applications.

Introduction Carotid atherosclerosis (CAS) is a disease of the aorta caused by lipid metabolism disorders and local inflammation. Acupuncture combined with traditional western medicine (such as aspirin or atorvastatin) for the treatment of CAS has been widely applied in clinical practice, but there is still a lack of supporting evidence for its efficacy and safety on CAS. Therefore, this systematic review and network meta-analysis (NMA) will summarise the effects of different types of acupuncture treatments on CAS, and a ranking of the therapeutic classes will also be presented, aiming to provide evidence-based medicine for its extensive clinical application.Methods and analysis Systematic and NMA searches will be conducted in seven electronic databases: PubMed, EMBASE, Medline, Cochrane Library, Chinese National Knowledge Infrastructure, Wanfang Database and Chongqing VIP databases. The search time is from their inception to December 2020, regardless of language and publication type. Randomised controlled trials and controlled clinical trials that include patients with CAS receiving acupuncture therapy compared with a control group will be considered eligible. The primary outcomes include the carotid intima-media thickness and vessel plaque quantification; the secondary outcomes include the carotid plaque Crouse score, greyscale median, lipid levels, the incidence of cardiovascular events, safety and adverse events. The selection of studies, data extraction, quality assessment and risk of bias assessment will be conducted by two independent reviewers. The NMA will be analysed with Stata V.15.0, RevMan V.5.3 software and WinBUGS V.1.4.3.Ethics and dissemination Ethical approval will not be required for this study as it will be based on de-identified, aggregated published data. We will publish the findings in a peer-reviewed journal.PROSPERO registration number CRD42020207260.

A novel, simple Jerk chaotic circuit with three current feedback operational amplifiers included (CFOA-JCC) is proposed, which has a simpler circuit structure, fewer components, but higher frequency characteristics. The dynamic behaviors of CFOA-JCC are analyzed, including equilibrium, stability, Lyapunov exponent, bifurcation diagram, offset boosting, and phase diagram. Furthermore, the frequency spectrum characteristic of the ordinary op-amps Jerk chaotic circuit was compared with CFOA-JCC under the same circuit parameters, and the chaotic attractor frequency of CFOA-JCC can reach about 650 kHz, much better than that of ordinary op-amps (12 kHz). Numerical simulation shows that CFOA-JCC has coexisting attractors, verified by hardware circuit experiments.

Investigation of the classical self-excited and hidden attractors in the modified Chua’s circuit is a hot and interesting topic. In this article, a novel Chua’s circuit system with an absolute item is investigated. According to the mathematical model, dynamic characteristics are analyzed, including symmetry, equilibrium stability analysis, Hopf bifurcation analysis, Lyapunov exponents, bifurcation diagram, and the basin of attraction. The hidden attractors are located theoretically. Then, the coexistence of the hidden limit cycle and self-excited chaotic attractors are observed numerically and experimentally. The numerical simulation results are consistent with the FPGA implementation results. It shows that the hidden attractor can be localized in the digital circuit.

Summary: Recent studies have demonstrated that human astrocytes and fibroblasts can be directly converted into functional neurons by small molecules. However, fibroblasts, as a potentially better cell resource for transplantation, are not as easy to reprogram as astrocytes regarding their fate to neurons, and chemically induced neurons (iNs) with low efficiency from fibroblasts resulted in limited application for the treatment of neurological disorders, including depression. Here, we report that human fibroblasts can be efficiently and directly reprogrammed into glutamatergic neuron-like cells by serially exposing cells to a combination of small molecules. These iNs displayed neuronal transcriptional networks, and also exhibited mature firing patterns and formed functional synapses. Importantly, iNs could integrate into local circuits after transplantation into postnatal mouse brain. Our study provides a rapid and efficient transgene-free approach for chemically generating neuron-like cells from human fibroblasts. Furthermore, our approach offers strategies for disease modeling and drug discovery in central nervous system disorders. : In this article, Dai and colleagues show that human fibroblasts can be efficiently and directly reprogrammed into glutamatergic neuron-like cells by a combination of small molecules. These iNs displayed neuronal transcriptional networks, exhibited mature firing patterns and could also integrate into local circuits after transplantation. The study provides an efficient transgene-free approach for chemically generating neuron-like cells from human fibroblasts. Keywords: direct reprogramming, fibroblasts to neurons, small molecules, high efficiency, cell transplantation, glutamatergic neurons

Functional trait ecology demonstrates the significance of the leaf economics spectrum in understanding plants’ trade-off between acquisitive and conservative resource utilization. However, whether trait variations of different vegetative organs are coordinated and whether the plant economics spectrum is characterized by more than one vegetative organ remain controversial. To gain insights into these questions, within a tropical cloud forest in Hainan Island, a total of 13 functional traits of 84 tree species were analyzed here, including leaf, stem and root traits. By using standardized major axis (SMA) regression and principal components analysis, we examined the trait variations and correlations for deciphering plants’ trade-off pattern. We found decreases of leaf phosphorus content, leaf nitrogen content and specific leaf area and increases of leaf mass per unit area (LMA), wood density and leaf thickness along the first principal component, while there were decreases of specific root length and specific root area and increases of root tissue density along the second principal component. Root phosphorus and nitrogen contents were significantly positively associated with the phosphorus and nitrogen contents of both stem and leaf. Wood density was significantly positively associated with LMA and leaf thickness, but negatively associated with leaf thickness and specific leaf area. Our results indicate that, in the tropical cloud forest, there is a “fast–slow” economic spectrum characterized by leaf and stem. Changes of nutrient trait are coordinated, whereas the relationships of morphological traits varied independently between plant above- and below-ground parts, while root nutrient traits are decoupled from root morphological traits. Our findings can provide an insight into the species coexistence and community assembly in high-altitude tropical forests.

Escalating anthropogenic pressures now threaten ~60% of primate species across the world with extinction. Developing effective evidence-based conservation for threatened primate species requires accurate and precise information on their population abundance. However, standard ecological field techniques are costly in terms of time, resources and manpower, meaning that the effectiveness of alternative survey and monitoring methods must be investigated. Thermal infrared imaging using drones may be able to improve ability to detect individuals and accuracy of population abundance estimates for primate species at lower cost. Here we use a drone with a thermal infrared sensor to survey the largest social group (Group C) of the Hainan gibbon (Nomascus hainanus), the world’s rarest primate species, which survives as a remnant population in Bawangling National Nature Reserve, Hainan, China. Group C is known to currently contain nine Hainan gibbon individuals based on regular visual monitoring. Drone surveys conducted over two consecutive days and nights in April 2019 demonstrated that thermal infrared imaging can detect the presence of different gibbon individuals in this social group, with comparable group size estimates to regular visual monitoring, and provides the first information about Hainan gibbon sleeping behavior and the range of nocturnal body temperatures for the species. This method can therefore be used to monitor other Hainan gibbon groups in the future, and can also be used to survey individuals and study nocturnal behaviors in other threatened or cryptic primate species.

Abstract Background Long non-coding RNAs (lncRNAs) play an important role in tumorigenesis. Vocal cord leukoplakia is a precancerous lesion in otolaryngological practice. Till now, the expression patterns and functions of lncRNAs in vocal cord leukoplakia have not been well understood. In this study, we used microarrays to investigate the aberrantly expressed lncRNAs and mRNAs in vocal cord leukoplakia and adjacent non-neoplastic tissues. Methods Gene Ontology and pathway analyses were performed to determine the significant function and pathways of the differentially expressed mRNAs. qRT-PCR was performed to further validate the expression of selected lncRNAs and mRNAs in vocal cord leukoplakia. Results Our study identified 170 differentially expressed lncRNAs and 99 differentially expressed mRNAs, including 142 up-regulated lncRNAs and 28 down-regulated lncRNAs, and 54 up-regulated mRNAs and 45 down-regulated mRNAs. Among these, XLOC_000605 and DLX6-AS1 were the most aberrantly expressed lncRNAs. Furthermore, we identified an antisense lncRNA (LOC100506801), an enhancer-like lncRNA (AK057351) and three long intergenetic noncoding RNAs including XLOC_008001, XLOC_011989 and XLOC_007341. Conclusions Our results revealed that many lncRNAs were differentially expressed between vocal cord leukoplakia tissues and normal tissue, suggesting that they may play a key role in vocal cord leukoplakia tumorigenesis.

This paper reports a hidden chaotic system without equilibrium point. The proposed system is studied by the software of MATLAB R2018 through several numerical methods, including Largest Lyapunov exponent, bifurcation diagram, phase diagram, Poincaré map, time-domain waveform, attractive basin and Spectral Entropy. Seven types of attractors are found through altering the system parameters and some interesting characteristics such as coexistence attractors, controllability of chaotic attractor, hyperchaotic behavior and transition behavior are observed. Particularly, the Spectral Entropy algorithm is used to analyze the system and based on the normalized values of Spectral Entropy, the state of the studied system can be identified. Furthermore, the system has been implemented physically to verify the realizability.

Novel memristive hyperchaotic system designs and their engineering applications have received considerable critical attention. In this paper, a novel multistable 5D memristive hyperchaotic system and its application are introduced. The interesting aspect of this chaotic system is that it has different types of coexisting attractors, chaos, hyperchaos, periods, and limit cycles. First, a novel 5D memristive hyperchaotic system is proposed by introducing a flux-controlled memristor with quadratic nonlinearity into an existing 4D four-wing chaotic system as a feedback term. Then, the phase portraits, Lyapunov exponential spectrum, bifurcation diagram, and spectral entropy are used to analyze the basic dynamics of the 5D memristive hyperchaotic system. For a specific set of parameters, we find an unusual metastability, which shows the transition from chaotic to periodic (period-2 and period-3) dynamics. Moreover, its circuit implementation is also proposed. By using the chaoticity of the novel hyperchaotic system, we have developed a random number generator (RNG) for practical image encryption applications. Furthermore, security analyses are carried out with the RNG and image encryption designs.

In this work, a novel 6D four-wing hyperchaotic system with a line equilibrium based on a flux-controlled memristor model is proposed. The novel system is inspired from an existing 5D four-wing hyperchaotic system introduced by Zarei (2015). Fundamental properties of the novel system are discussed, and its complex behaviors are characterized using phase portraits, Lyapunov exponential spectrum, bifurcation diagram, and spectral entropy. When a suitable set of parameters are chosen, the system exhibits a rich repertoire of dynamic behaviors including double-period bifurcation of the quasiperiod, a single two-wing, and four-wing chaotic attractors. Further analysis of the novel system shows that the multiple coexisting attractors can be observed with different system parameter values and initial values. Moreover, the feasibility of the proposed mathematical model is also presented by using Multisim simulations based on an electronic analog of the model. Finally, the active control method is used to design the appropriate controller to realize the synchronization between the proposed 6D memristive hyperchaotic system and the 6D hyperchaotic Yang system with different structures. The Routh–Hurwitz criterion is used to prove the rationality of the controller, and the feasibility and effectiveness of the proposed synchronization method are proved by numerical simulations.

In this paper, a method for determining the initial value of the hidden attractors in the Chua system is studied. The initial value of the hidden attractors can be calculated quickly and accurately by the proposed method, and the hidden attractors can be found by numerical simulation. Then, the initial values of the hidden attractors are set accurately by digital signal processor (DSP), so as to the circuit realization of the chaotic system with hidden attractors is performed. The results show that the numerical simulation results of Matlab are consistent with the experimental results of DSP.

Aqueous battery has been gained much more interest for large-scale energy storage fields due to its excellent safety, high power density and low cost. Cryptomelane-type KMn8O16 confirmed by X-ray diffraction (XRD) was successfully synthesized by a modified hydrothermal method, followed by annealed at 400°C for 3 h. The morphology and microstructure of as-prepared KMn8O16 investigated by field-emission scanning electron microscopy (FE-SEM) with the energy spectrum analysis (EDS) and transmission electron microscopy (TEM) demonstrate that one-dimensional nano rods with the length of about 500 nm constitute the microspheres with the diameter about 0.5~2 μm. The cyclic voltammetry measurement displays that the abundant intercalation of zinc ions on the cathode takes place during the initial discharge process, indicating that cryptomelane-type KMn8O16 can be used as the potential cathode material for aqueous zinc ion batteries. The electrode shows a good cycling performance with a reversible capacity of up to 77.0 mAh/g even after 100 cycles and a small self-discharge phenomenon.

Large volume helicon plasma sources are of particular interest for large scale semiconductor processing, high power plasma propulsion and recently plasma-material interaction under fusion conditions. This work is devoted to studying the coupling of four typical RF antennas to helicon plasma with infinite length and diameter of 0.5 m, and exploring its frequency dependence in the range of 13.56-70 MHz for coupling optimization. It is found that loop antenna is more efficient than half helix, Boswell and Nagoya III antennas for power absorption; radially parabolic density profile overwhelms Gaussian density profile in terms of antenna coupling for low-density plasma, but the superiority reverses for high-density plasma. Increasing the driving frequency results in power absorption more near plasma edge, but the overall power absorption increases with frequency. Perpendicular stream plots of wave magnetic field, wave electric field and perturbed current are also presented. This work can serve as an important reference for the experimental design of large volume helicon plasma source with high RF power.

Recently, with the development of the space program there are growing concerns about the influence of spaceflight on tissue engineering. The purpose of this study was thus to determine the variations of neural stem cells (NSCs) during spaceflight. RNA-Sequencing (RNA-Seq) based transcriptomic profiling of NSCs identified many differentially expressed mRNAs and miRNAs between space and earth groups. Subsequently, those genes with differential expression were subjected to bioinformatic evaluation using gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes pathway (KEGG) and miRNA-mRNA network analyses. The results showed that NSCs maintain greater stemness ability during spaceflight although the growth rate of NSCs was slowed down. Furthermore, the results indicated that NSCs tended to differentiate into neuron in outer space conditions. Detailed genomic analyses of NSCs during spaceflight will help us to elucidate the molecular mechanisms behind their differentiation and proliferation when they are in outer space.

Various mature tissue-resident cells exhibit progenitor characteristics following injury. However, the existence of endogenous stem cells with multiple lineage potentials in the adult spinal cord remains a compelling area of research. In this study, we present a cross-species investigation that extends from development to injury. We used single-nucleus transcriptomic sequencing and genetic lineage tracing to characterize neural cells in the spinal cord. Our findings show that ciliated ependymal cells lose neural progenitor gene signatures and proliferation ability following the differentiation of NPCs within the ventricular zone. By combining single-nucleus transcriptome datasets from the rhesus macaque spinal cord injury (SCI) model with developmental human spinal cord datasets, we revealed that ciliated ependymal cells respond minimally to injury and cannot revert to a developmental progenitor state. Intriguingly, we observed astrocytes transdifferentiating into mature oligodendrocytes postinjury through lineage tracing experiments. Further analysis identifies an intermediate-state glial cell population expressing both astrocyte and oligodendrocyte feature genes in adult spinal cords. The transition ratio from astrocytes into oligodendrocytes increased after remodeling injury microenvironment by functional scaffolds. Overall, our results highlight the remarkable multilineage potential of astrocytes in the adult spinal cord. [ABSTRACT FROM AUTHOR]