Schwann Cell-Derived Exosomes Induced Axon Growth after Spinal Cord Injury by Decreasing PTP-σ Activation on CSPGs via the Rho/ROCK Pathway.

Spinal cord injury (SCI) is a severe neurological condition that involves a lengthy pathological process. This process leads to the upregulation of chondroitin sulfate proteoglycans (CSPGs) by reactive glia, which impedes repair and regeneration in the spinal cord. The role of the CSPG-specific receptor protein tyrosine phosphatase-sigma (PTP-σ) in post-SCI remains largely unexplored. Exosomes have great potential in the diagnosis, prognosis, and treatment of SCI due to their ability to easily cross the blood‒brain barrier. Schwann cell-derived exosomes (SCDEs) promote functional recovery in mice post-SCI by decreasing CSPG deposition. However, the mechanism by which SCDEs decrease CSPGs after SCI remains unknown. Herein, we observed elevated levels of PTP-σ and increased CSPG deposition during glial scar formation after SCI in vivo. After SCDEs were injected into SCI mice, CSPG deposition decreased in scar tissue at the injury site, the expression of PTP-σ increased during axonal growth around the injury site, and motor function subsequently recovered. Additionally, we demonstrated that the use of both Rho/ROCK inhibitors and SCDEs inhibited the reparative effects of SCDEs on scar tissue after SCI. In conclusion, our study revealed that treatment with SCDEs targeting the Rho/ROCK signaling pathway reduced PTP-σ activation in the CSPG post-SCI, which inhibited scar tissue formation.

Exploring the Landscape of Hydrogel Therapy for Spinal Cord Injury: A Bibliometric and Visual Analysis (1991-2023).

BACKGROUND: This study aimed to conduct a bibliometric analysis of the literature on hydrogel therapy for spinal cord injury to visualize the research status, identify hotspots, and explore the development trends in this field. METHODS: Web of science Core Collection database was searched for relevant studies published between January 1991 and December 2023. Data such as journal title, author information, institutional affiliation, country, citation, and keywords were extracted. Bibliometrix, CiteSpace, and VOSviewer were used to perform bibliometric analysis of the retrieved data. RESULTS: A total of 1099 articles pertaining to hydrogel therapy for spinal cord injury were retrieved, revealing an upward trajectory in both annual publication volume and cumulative publication volume. Biomaterials emerged as the journal with the highest number of publications and the most rapid cumulative publication growth, contributing 84 articles. Among authors, Shoichet MS stood out with the highest number of publications and citations, totaling 66 articles. The University of Toronto led in institutional contributions with 65 publications, while China dominated in country-specific publications, accounting for 374 articles. However, to foster significant academic achievements, it is imperative for diverse authors, institutions, and countries to enhance collaboration. Current research in this field concentrates on scaffold architecture, nerve growth factor, the fibrotic microenvironment, and guidance channels. Simultaneously, upcoming research directions prioritize 3D bioprinting, injectable hydrogel, inflammation, and nanoparticles within the realm of hydrogel therapy for spinal cord injuries. CONCLUSIONS: In summary, this study provided a comprehensive analysis of the current research status and frontiers of hydrogel therapy for spinal cord injury. The findings provide a foundation for future research and clinical translation efforts of hydrogel therapy in this field.

Sarsasapogenin regulates the immune microenvironment through MAPK/NF-kB signaling pathway and promotes functional recovery after spinal cord injury.

Spinal cord injury (SCI) occurs as a result of traumatic events that damage the spinal cord, leading to motor, sensory, or autonomic function impairment. Sarsasapogenin (SA), a natural steroidal compound, has been reported to have various pharmacological applications, including the treatment of inflammation, diabetic nephropathy, and neuroprotection. However, the therapeutic efficacy and underlying mechanisms of SA in the context of SCI are still unclear. This research aimed to investigate the therapeutic effects and mechanisms of SA against SCI by integrating network pharmacology analysis and experimental verification. Network pharmacology results suggested that SA may effectively treat SCI by targeting key targets such as TNF, RELA, JUN, MAPK14, and MAPK8. The underlying mechanism of this treatment may involve the MAPK (JNK) signaling pathway and inflammation-related signaling pathways such as TNF and Toll-like receptor signaling pathways. These findings highlight the therapeutic potential of SA in SCI treatment and provide valuable insights into its molecular mechanisms of action. In vivo experiments confirmed the reparative effect of SA on SCI in rats and suggested that SA could repair SCI by modulating the immune microenvironment. In vitro experiments further investigated how SA regulates the immune microenvironment by inhibiting the MAPK/NF-kB pathways. Overall, this study successfully utilized a combination of network pharmacology and experimental verification to establish that SA can regulate the immune microenvironment via the MAPK/NF-kB signaling pathway, ultimately facilitating functional recovery from SCI. Furthermore, these findings emphasize the potential of natural compounds from traditional Chinese medicine as a viable therapy for SCI treatment.

Plastic Waste Conversion by Leveraging Renewable Photo/Electro-Catalytic Technologies.

Plastics have revolutionized our lives; however, the exponential growth of their usage has led to a global crisis. More sustainable strategies are needed to address this dilemma and transform the plastics economy from a linearity to a circular model. Herein, we systematically summarize the recent progress in renewable energy-driven plastic conversion strategies, including photocatalysis, electrocatalysis, and their integration. By introducing the significant works, the design principles, mechanisms, and system regulations, we decipher and compare the various aspects of plastic conversion. These approaches show high reactivity and selectivity under environmentally benign conditions and provide alternative reaction pathways for plastic conversion. Plastic upcycling as a chemical feedstock can yield value-added chemicals and fuels, contributing to the establishment of a sustainable and circular economy. Additionally, several innovations in reaction engineering and system designs are presented. Finally, the challenges and perspectives of sustainable energy-driven plastic conversion technologies are comprehensively discussed.

Coordination function index: A novel indicator for assessing hindlimb locomotor recovery in spinal cord injury rats based on catwalk gait parameters.

In preclinical studies of spinal cord injury (SCI), behavioral assessments are crucial for evaluating treatment effectiveness. Commonly used methods include Basso, Beattie, Bresnahan (BBB) score and the Louisville swim scale (LSS), relying on subjective observations. The CatWalk automated gait analysis system is also widely used in SCI studies, providing extensive gait parameters from footprints. However, these parameters are often used independently or combined simply without utilizing the vast amount of data provided by CatWalk. Therefore, it is necessary to develop a novel approach encompassing multiple CatWalk parameters for a comprehensive and objective assessment of locomotor function. In this work, we screened 208 CatWalk XT gait parameters and identified 38 suitable for assessing hindlimb motor function recovery in a rat thoracic contusion SCI model. Exploratory factor analysis was used to reveal structural relationships among these parameters. Weighted scores for Coordination effectively differentiated hindlimb motor function levels, termed as the Coordinated Function Index (CFI). CFI showed high reliability, exhibiting high correlations with BBB scores, LSS, and T2WI lesion area. Finally, we simplified CFI based on factor loadings and correlation analysis, obtaining a streamlined version with reliable assessment efficacy. In conclusion, we developed a systematic assessment indicator utilizing multiple CatWalk parameters to objectively evaluate hindlimb motor function recovery in rats after thoracic contusion SCI.

Alternating current stimulation promotes neurite outgrowth and plasticity in neurons through activation of the PI3K/AKT signaling pathway.

As a commonly used physical intervention, electrical stimulation (ES) has been demonstrated to be effective in the treatment of central nervous system disorders. Currently, researchers are studying the effects of electrical stimulation on individual neurons and neural networks, which are dependent on factors such as stimulation intensity, duration, location, and neuronal properties. However, the exact mechanism of action of electrical stimulation remains unclear. In some cases, repeated or prolonged electrical stimulation can lead to changes in the morphology or function of the neuron. In this study, immunofluorescence staining and Sholl analysis are used to assess changes in the neurite number and axon length to determine the optimal pattern and stimulation parameters of ES for neurons. Neuronal death and plasticity are detected by TUNEL staining and microelectrode array assays, respectively. mRNA sequencing and bioinformatics analysis are applied to predict the key targets of the action of ES on neurons, and the identified targets are validated by western blot analysis and qRT-PCR. The effects of alternating current stimulation (ACS) on neurons are more significant than those of direct current stimulation (DCS), and the optimal parameters are 3 µA and 20 min. ACS stimulation significantly increases the number of neurites, the length of axons and the spontaneous electrical activity of neurons, significantly elevates the expression of growth-associated protein-43 (GAP-43) without significant changes in the expression of neurotrophic factors. Furthermore, application of PI3K/AKT-specific inhibitors significantly abolishes the beneficial effects of ACS on neurons, confirming that the PI3K/AKT pathway is an important potential signaling pathway in the action of ACS.

Internal reuse of methanol-to-olefin wastewater based on micro-channel separation coupling hydrocyclone regeneration.

Methanol-to-olefin (MTO) is a typical new coal chemical industry example. Due to the large volume of generated wastewater, complex composition including catalysts, aromatics and various oxygen-containing compounds, and serious environmental hazard, wastewater recycling is critical for sustainable industrial development and ecological protection. Herein, a swirl regenerating micro-channel separation (SRMS) technology was proposed to integrate deep filtration and hydrocyclone-enhanced regeneration. A small-scale experimental investigation was first conducted to verify the feasibility of the MTO wastewater treatment. A pilot SRMS device with a treatment capacity of 20 m3/h was constructed, and the device's continuous operation effect and stability were comprehensively evaluated. The separation performance of the SRMS device at different solution pH values and the impact of the hydrocyclone-enhanced regeneration of separation media were discussed in detail. At low solution pH values (<7), the SRMS device exhibits an average separation efficiency of 92.0% for fine particulate matter in wastewater, and the median particle size, d50, decreases from 1.55 to 0.6 µm. As the solution pH increases, the repulsive energy barrier for the medium-contaminant and contaminant-contaminant increases, inhibiting the deposition behavior of particulate pollutants. In addition, hydrocyclone desorbs contaminants deposited on the separation media and the average contaminant residual rate decreases from 3.3 to 0.2 wt%. We propose an industrial application for treating and reusing MTO wastewater (200 m3/h) using the SRMS technology based on the experimental results. The costs of the wastewater treatment process are as low as 0.25 CNY/m3, and the wastewater reuse rate is over 97% without chemical consumption. This work can provide an environmentally friendly and economically sustainable approach to the source management of MTO wastewater.

Enhancement of the classification and recovery process of fine mineral particles via a newly developed volute feed hydrocyclone.

Ore resources in the mining process form a large number of unmanageable tailings, mostly inhalable fine mineral particles, into the environment will cause serious pollution, and recycling is a precious resource. The cyclone classification provides the possibility for the recovery and exploitation of fine particles, but the recovery and utilization rate of conventional cyclone separation is seriously low, and the performance urgently should be optimized. In the present study, a new type of volute feed was proposed to strengthen the classification and recovery process of fine mineral particles. Combined with numerical simulation and experimental research, the effects of various structural parameters and operating parameters on the flow field distribution, particle motion, and classification performance were systematically examined. The obtained results reveal that the new volute feed structure can effectively reduce the internal turbulence and improve the flow field stability and particle classification efficiency. Compared with the traditional hydrocyclone, the classification efficiency of fine particles with new feed structure increases by 10-18%. Increasing underflow diameter and feed pressure and reducing overflow diameter and feed concentration are also beneficial to lessening classification particle size and enhancing classification performance. The currently achieved outcomes can provide valuable guidelines for further development of novel hydrocyclones.

Comparison of clinical outcomes associated with spinal cord stimulation (SCS) or conventional medical management (CMM) for chronic pain: a systematic review and meta-analysis.

OBJECTIVE: This study aims to evaluate the efficacy and safety of spinal cord stimulation (SCS) compared to conventional medical management (CMM) for patients diagnosed with chronic pain. Furthermore, the study seeks to compare the utilization of analgesics, as well as the long-term outcomes in terms of quality of life and functional capacity. DATA SOURCES: We systematically searched Cochrane Library, Web of Science, PubMed, and EMBASE for randomized controlled trials from inception up to February 2022. REVIEW METHODS: Inclusion and exclusion criteria were set according to the PICOS criteria. We searched for studies in which SCS was compared with CMM alone for chronic pain. Two reviewers independently identified eligible studies and extracted data. Risk of bias assessments were performed according to Cochrane review criteria and Interventional Pain Management Techniques-quality Appraisal of Reliability and Risk of Bias Assessment (IPM-QRB) criteria. RESULTS: The present meta-analysis comprised eight studies and included a total of 893 patients. Our findings demonstrate that spinal cord stimulation (SCS) in combination with conventional medical management (CMM) is associated with a significant reduction in visual analogue scale (VAS) pain intensity (P = 0.0005) and decreased scores on the McGill Pain Questionnaire (MPQ) (P < 0.0001). Moreover, SCS plus CMM was found to improve patients' quality of life, as evidenced by improvements in SF-36 scores (P < 0.00001), EQ-5D utility index (P = 0.008), and Oswestry Disability Index (ODI) (P < 0.00001). Based on the results of four high-quality randomized controlled trials (RCTs), the level of evidence supporting the efficacy of SCS for the treatment of painful neuropathy is graded as level I to II. In contrast, there is currently only low-level evidence to support the use of high-frequency stimulation and other chronic pain conditions, which can be attributed to a lack of sufficient randomized controlled trials. LIMITATIONS: The principal limitation of our study is the significant heterogeneity observed among the cohorts investigated. The primary source of this heterogeneity is the fact that spinal cord stimulation is indicated for the treatment of multiple chronic pain conditions. Moreover, variations in the stimulation parameters, differences among manufacturers, and the specific surgical implantation settings contribute to the increased heterogeneity observed in our analyses. To address this issue, we conducted a subgroup analysis based on specific situations and performed evidence synthesis to mitigate the potential impact of heterogeneity. These approaches allow for a more precise interpretation of the results and a more accurate evaluation of the quality of the included studies. CONCLUSIONS: SCS is an effective treatment to relieve the pain level of chronic pain, decrease analgesic usage, and increase long-term quality of life and functional capacity.

Application of combined granular media with opposite wettability for demulsification of oily wastewater by microchannel filter.

Oil-water separation with high efficiency and low energy consumption is a tremendous challenge in the green treatment of oily wastewater. In this paper, a novel filtration method with combined granular media for collaborative removal emulsified oil and suspended solids (SS) was proposed, followed by the exploration of demulsification feasibility and oil removal mechanism. The effect of the operation and structural parameters of the filter bed on oil separation performance was thoroughly investigated, and its feasibility for raw oily wastewater treatment was also explored. A remarkable demulsification performance was observed with the combined granular media filter, and a balance of separation efficiency and pressure drop in the emulsified oily wastewater filtration was also achieved subsequently. Effective oil droplet capture and coalescence were observed with a high speed camera system, and pore clogging could be avoided in combined media. The optimal parameters of the combined media filter (CMF) were concluded to be a combined media ratio of 1:1, a superficial velocity of 0.20 m min-1, and a bed porosity of 58.1%. The average oil and suspended solids concentrations in raw oily wastewater was decreased to 8.4 mg/L and 23.3 mg/L during the pilot-scale operation, which indicated that the novel filter composed of combined media had better performance in collaboratively removing oil and SS, even in the period of fluctuating influent parameters. It is believed that a novel and efficient oil removal method, especially including of emulsified oil removal was provided, which also shows great potential and value for the green treatment of industrial oily wastewater.

Effect of plant tannin and glycerol on thermoplastic starch: Mechanical, structural, antimicrobial and biodegradable properties.

Thermoplastic starch is a good candidate for preparing biobased plastics. However, certain deficiencies in the ingredient, such as its poor mechanical strength and lack of antibacterial activity, need to be strengthened. In this work, a new method of producing TPS via extrusion and injection at a large scale was explored using tannin and glycerol simultaneously. The effect of the tannin content on the performance of TPS was investigated. The results showed that the synergistic effect of a small amount of tannin (2.5-7.5 wt%) and glycerol increased the tensile strength and maintained a stable elongation at break, and tannin aggregation occurred in TPS at higher tannin contents, which corresponded to increased tensile and flexural strengths. 15T-TPS has optimal mechanical performance with maximal relative crystallinity. The introduced tannin in TPS effectively enhanced the thermal stability but slightly reduced the biodegradability in soil and endowed TPS with antibacterial activity. Therefore, TPS containing tannins has the potential to be used in biomedical, food packaging and agricultural areas.

Cooperative physical separation of oil and suspended solids from methanol-to-olefin wastewater: A pilot study.

Methanol-to-olefin (MTO) is an important non-petroleum chemical process for the preparation of light olefins. However, the MTO process consumes copious amounts of water and produces large amounts of untreated effluent. Therefore, the realization of efficient wastewater treatment and recycling is key to the green low-carbon development of MTO. Here, a cooperative process combining swirl regenerating micro-channel separation (SRMS) and combined fibrous coalescence (CFC) technologies was proposed to separate high contents of oil and suspended matter in MTO wastewater. Using a pilot device with a treatment capacity of 1 m3/h, the average oil content in MTO wastewater decreased from 750 mg/L to <30 mg/L, while the average content of suspended matter decreased from 108 mg/L to <15 mg/L. Compared with a commercial MTO wastewater treatment process (olefin production capacity of 0.6 million tons per annum), the proposed method could reduce wastewater discharges and costs by 57% and US$ 0.23 million per annum respectively. Equipment costs and operational energy consumption were also reduced by 30% and >95% respectively. The combined process may provide the basis for the green and sustainable treatment of MTO wastewater and its recycling.

Toward an Orthogonal Protein Lysine Acylation and Deacylation System.

Lysine acetylation is one of the most basic molecular mechanisms to mediate protein functions in living organisms, and its abnormal regulation has been linked to many diseases. The drug development associated to this process is of great significance but severely hindered by the complex interplay of lysine acetylation and deacetylation in thousands of proteins, and we reasoned that targeting a specific protein acetylation or deacetylation event instead of the related enzymes should be a feasible solution to this issue. Toward this goal, we devised an orthogonal lysine acylation and deacylation (OKAD) system, which potentially could precisely dissect the biological consequence of an individual acetylation or deacetylation event in living cells. The system includes a genetically encoded acylated lysine (PhOAcK) that is not a substrate of endogenous deacetylases, and an evolved sirtuin (CobB2/CobB3) that displays PhOAcK deacylase activities as well as reduced deacetylase activities. We believe the strategy introduced here holds potential for future in-depth biological applications.

Interaction of Chlorella vulgaris and bacteria when co-cultivated in anaerobically digested swine manure.

Mono-culture and co-culture of algae (Chlorella vulgaris) and bacteria (activated sludge) on anaerobically digested swine manure (ADSM) were investigated in this research. The results showed that during the co-cultivation biomass growth was promoted (2.43 ± 0.11 g/L) compared with the algae-only culture (1.09 ± 0.03 g/L), and the aerobic bacteria growth was initially promoted, then inhibited. The SEM (Scanning Electron Microscope) observation indicated that the amount of the C. vulgaris increased while bacteria 'disappeared' over time. After 30 min settlement, 95.5% of the biomass in co-cultivation group precipitated, while only 40.4% of the biomass settled for the algae-only group was. It is believed that the presence of bacteria enhanced the settling rate through the formation of algal consortium flocs. Bacterial community diversity and composition were measured and the results indicated that the bacterial diversity dropped and the bacterial active classes changed in the co-cultivation group.

Surface cross-linked thermoplastic starch with different UV wavelengths: mechanical, wettability, hygroscopic and degradation properties.

Here, we report a method to improve the properties of thermoplastic starch (TPS) by surface ultraviolet (UV) cross-linking. TPS sheets were prepared by injection molding and coated with an ethanol solution of photo-initiator TPO (2,4,6-trimethyl benzoyl diphenyl phosphine oxide), then, irradiated by UV with different wavelengths for 15 min. Untreated and irradiated TPS sheets were characterized using tensile and bending tests, impact tests, dynamic mechanical thermal analysis (DMTA) and infrared spectroscopy (FTIR). FTIR spectra showed that UV irradiation can effectively trigger surface cross-linking of TPS sheets. The mechanical and dynamic mechanical properties of the TPS were improved and the optimized properties were obtained by 308 nm UV irradiation. A tensile strength of 4.1 MPa, a bending strength of 2.7 MPa, an impact strength of 96.8 kJ m-2, and the corresponding activation energy of 251.22 kJ mol-1 were obtained. The water contact angle and moisture absorption of the samples were also investigated and the 308 nm UV irradiated sheets have a contact angle of 74°. Moisture absorption rate as a function of the square root of time showed a sigmoid curve including a linear stage which conforms to Fick's second law. The samples irradiated by 308 nm UV had the lowest equilibrium moisture absorption rate M ∞ and the longest time T 0 to enter into the Fick's diffusion stage and the lowest slope K and diffusion coefficient D. All samples displayed biodegradable properties when buried in soil. This method has potential applications for agricultural mulch films, packing and medical film products.

Heterogeneous Suzuki-Miyaura coupling of heteroaryl ester via chemoselective C(acyl)-O bond activation.

A site-selective supported palladium nanoparticle catalyzed Suzuki-Miyaura cross-coupling reaction with heteroaryl esters and arylboronic acids as coupling partners was developed. This methodology provides a heterogeneous catalytic route for aryl ketone formation via C(acyl)-O bond activation of esters by successful suppression of the undesired decarbonylation phenomenon. The catalyst can be reused and shows high activity after eight cycles. The XPS analysis of the catalyst before and after the reaction suggested that the reaction might be performed via a Pd0/PdII catalytic cycle that began with Pd0.