How to form shared objects to enhance university-school collaboration? A cultural-historical activity theory perspective.

Introduction: University-school (U-S) collaboration has proven to be an effective approach for teacher professional development, but it could be hampered by the lack of shared objects. To understand how shared objects are formed in U-S collaboration, this research established a university-school collaborated Change Laboratory in W primary school based on cultural-historical activity theory, which is under the background of Chinese teaching research activity. Methods: Recordings of meetings throughout the year were transcribed into texts and coded, and then analyzed via the method of grounded theory and contradiction analysis. Results: The findings reveal that, in comparison to previous studies regarding shared object formation process, this study identified an special phase named "experimental object," which highlights the significance of experimentation in U-S collaboration. Also, multiple contradictions are recognized as the driving force for shared object formation which would gradually transform into fundamental conflicts between tools. The main contradictions identified include those between scientific and daily concepts, university culture and school culture, as well as new experiment and old routine. Discussion: The current study implicates that U-S collaboration is an expansive learning process to acquire unknown knowledge, which necessitates both parties engaging in exploration and experimentation together. Furthermore, shared object formation within U-S collaboration requires participants to focus on developing teaching tools while consciously undergoing changes in aspects such as logic of thinking, culture and routine.

Progress in the study of molecular mechanisms of intervertebral disc degeneration.

Degenerative intervertebral disc disease (IVDD) is one of the main spinal surgery, conditions, which markedly increases the incidence of low back pain and deteriorates the patient's quality of life, and it imposes significant social and economic burdens. The molecular pathology of IVDD is highly complex and multilateral however still not ompletely understood. New findings indicate that IVDD is closely associated with inflammation, oxidative stress, cell injury and extracellular matrix metabolismdysregulation. Symptomatic management is the main therapeutic approach adopted for IVDD, but it fails to address the basic pathological changes and the causes of the disease. However, research is still focusing on molecular aspects in terms of gene expression, growth factors and cell signaling pathways in an attempt to identify specific molecular targets for IVDD treatment. The paper summarizes the most recent achievements in molecularunderstanding of the pathogenesis of IVDD and gives evidence-based recommendations for clinical practice.

A new strategy for intervertebral disc regeneration: The synergistic potential of mesenchymal stem cells and their extracellular vesicles with hydrogel scaffolds.

Intervertebral disc degeneration (IDD) is a disease that severely affects spinal health and is prevalent worldwide. Mesenchymal stem cells (MSCs) and their derived extracellular vesicles (EVs) have regenerative potential and have emerged as promising therapeutic tools for treating degenerative discs. However, challenges such as the harsh microenvironment of degenerated intervertebral discs and EVs' limited stability and efficacy have hindered their clinical application. In recent years, hydrogels have attracted much attention in the field of IDD therapy because they can mimic the physiologic microenvironment of the disc and provide a potential solution by providing a suitable growth environment for MSCs and EVs. This review introduced the biological properties of MSCs and their derived EVs, summarized the research on the application of MSCs and EVs in IDD, summarized the current clinical trial studies of MSCs and EVs, and also explored the mechanism of action of MSCs and EVs in intervertebral discs. In addition, plenty of research elaborated on the mechanism of action of different classified hydrogels in tissue engineering, the synergistic effect of MSCs and EVs in promoting intervertebral disc regeneration, and their wide application in treating IDD. Finally, the challenges and problems still faced by hydrogel-loaded MSCs and EVs in the treatment of IDD are summarized, and potential solutions are proposed. This paper outlines the synergistic effects of MSCs and EVs in treating IDD in combination with hydrogels and aims to provide theoretical references for future related studies.

Bibliometric and visual analysis of spinal cord injury-associated macrophages from 2002 to 2023.

Background: Spinal cord injury (SCI) triggers motor, sensory, and autonomic impairments that adversely damage patients' quality of life. Its pathophysiological processes include inflammation, oxidative stress, and apoptosis, although existing treatment options have little success. Macrophages have a vital function in controlling inflammation in SCI, with their M1-type and M2-type macrophages dominating early inflammatory effects and late brain tissue repair and regeneration, respectively. However, there is a dearth of rigorous bibliometric study in this sector to explore its dynamics and trends. This study intends to examine the current status and trends of macrophage usage in SCI using bibliometric methodologies, which may drive novel therapeutic options. Methods: In this study, the Web of Science Core Collection (WOSCC) was utilized to collect publications and reviews on macrophages in SCI from 2002 to 2023. Bibliometrics and visualization analyses were performed by VOSviewer, CiteSpace, the R package "bibliometrix", and online analytic platforms. These analyses covered a variety of aspects, including countries and institutions, authors and co-cited authors, journals and co-cited journals, subject categories, co-cited references, and keyword co-occurrences, in order to provide insights into the research trends and hotspots in this field. Results: 1,775 papers were included in the study, comprising 1,528 articles and 247 reviews. Our research analysis demonstrates that the number of relevant studies in this sector is expanding, specifically the number of publications in the United States and China has risen dramatically. However, there are fewer collaborations between institutions in different nations, and international cooperation needs to be reinforced. Among them, Popovich PG became the leader in the field, and significant journals include Experimental Neurology, Journal of Neurotrauma, and Journal of Neuroscience. Research hotspots involve macrophage polarization, microglia, astrocytes, signaling, cytokines, inflammation, and neuroprotection. Conclusions: This analysis gives, for the first time, a comprehensive overview of bibliometric studies on macrophages in SCI over the past 20 years. This study not only gives an extensive picture of the knowledge structure but also indicates trends in the subject. The systematic summarization gives a complete and intuitive understanding of the link between spinal cord damage and macrophages and provides a great reference for future related studies.

Removal of Heavy Metals from Acid Mine Drainage by Red Mud-Based Geopolymer Pervious Concrete: Batch and Long-Term Column Studies.

Various metal ions in acid mine drainage (AMD) cause environmental pollution. Due to the unique advantages of heavy metal treatment and gelling properties, previous concretes incorporating red mud have attracted extensive attention in AMD passive treatment, which utilises naturally occurring chemicals to cleanse contaminated mine waters with low operating costs. This study aims to develop red mud-based geopolymer pervious concrete as an eco-friendly method to remove heavy metals in AMD. Compared with raw pervious concrete, red mud-based geopolymer pervious concrete improves the purification efficiency of heavy metals. The high rate of acid reduction and metal removal by the geopolymer is attributed to the dissolution of portlandite in red mud. Precipitation of metal hydroxides seems to be the dominant metal removal mechanism. Under optimal conditions (influent pH = 4.0 and the hydraulic retention time = 24 h), red mud-based geopolymer pervious concrete could completely remove Cu(II), Mn(II), Cd(II) and Zn(II) by up to 10 mg/L, 10 mg/L, 1.6 mg/L and 16 mg/L, respectively. When the influent pH is 2.5, the hydrolysis of Fe(III) released from red mud increases the consumption of OH-. Moreover, when the influent pH is 4.0, the precipitation of CaSO4 promotes the dissolution of portlandite and metal removal. Therefore, red mud has demonstrated feasibility in the manufacturing of geopolymer-based pervious concrete for purification AMD.

The Development of Transformative Agency of Teachers in Teaching Research Activities in China.

Teaching research activities (TRA) in China are practical and reflective research of teachers on teaching. These required activities are meant to ensure quality education and facilitate the professional development of teachers. However, in TRA, teachers encounter many challenges such as low efficiency and weak team collaboration. These problems make it hard to achieve the expected outcomes. W Primary School reformed its activities using Change Laboratory, a formative intervention approach to workplace learning and development based on activity theory. The data collected included seven recorded meetings in the Change Laboratory. The conversations in the meetings were then transcribed into texts. A deductive method of content analysis was used to code the data, focusing on categorizing comments of teachers about the transformative agency. The findings showed the following: (1) There were five types of transformative agencies, namely, resisting, criticizing, explicating, envisioning, and committing to actions. Resisting and criticizing were represented less frequently, and taking action did not emerge as a type of transformative agency. (2) The comments about transformative agency about tools were more frequent than comments about other elements in the activity system. (3) There were some differences in the expression of transformative agency across participants. At the end of this study, the implications for the development of TRA are discussed.

Effect of RM-based-passivator for the remediation of two kinds of Cd polluted paddy soils and mechanism of Cd(II) adsorption.

This study aimed to investigate the effects of red mud-based-passivator (RM-based-passivator) on rice yield, cadmium (Cd) in brown rice, pH and available Cd in Cd-polluted soil by pot experiments, and to explore the adsorption mechanism of the passivator by scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDX), fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) analysis. The results showed that this passivator obviously improved the pH, reduced the available Cd in soil and the Cd content in brown rice in Changsha Cd polluted soil (CS soil), while had little effect on Hengyang Cd polluted soil (HY soil). Compared with the control, the soil pH increased in the range from 0.31 to 1.37, the available Cd in soil decreased in the range from 13.25% to 52.34%, and the total Cd in brown rice decreased in the range from 46.44% to 84.98% in CS soil. Considering the impacts of RM-based-passivator on the growth of rice, the Cd content in brown rice, and the pH and available Cd in soil, 0.10-0.30% (w/w) of the passivator is recommended to apply in CS soil but not in HY soil. Based on the analysis of SEM, EDX, FTIR and XRD, the mechanism of Cd(II) adsorption by RM-based-passivator included physical adsorption, surface complexation and ion exchange. The present results indicated that the appropriate addition of RM-based-passivator could be an effective strategy for the remediation of acidic Cd-polluted soils.

Experimental and theoretical insights into kinetics and mechanisms of hydroxyl and sulfate radicals-mediated degradation of sulfamethoxazole: Similarities and differences.

Hydroxyl radical (•OH)- and sulfate radical ()-based advanced oxidation technologies (AOTs) have been proven an effective method to remove antibiotics in wastewater treatment plants (WWTPs). This study aims to gain insights into kinetics and mechanisms of neutral sulfamethoxazole (SMX) degradation, a representative antibiotic, by •OH and using an experimental and theoretical approach. First, the second-order rate constants (k) of SMX with •OH and were determined to be (7.27 ± 0.43) × 109 and (2.98 ± 0.32) × 109 M-1 s-1 in UV/H2O2 and UV/persulfate (UV/PS) systems, respectively. The following theoretical calculations at the M06-2X level of theory revealed that addition of radicals to the benzene ring is the most favorable first-step reaction for both •OH and , but that exhibits higher energy barriers and selectivity than •OH due to steric hindrance. We further analyzed subsequent reactions and, interestingly, our findings closely corroborated HOMO/LUMO distributions of SMX to the oxidation pathways. Finally, the estimation of energy consumption for UV alone, •OH-, and -mediated oxidation processes was compared. These comparative results, for the first time, provide insights into the similarities and differences of degradation of SMX by •OH/ at the molecular level and can help improve antibiotics removal using radical based AOTs in WWTPs.

Spatial variation of sediment bacterial community in an acid mine drainage contaminated area and surrounding river basin.

Microbial community is sensitive to the variations of environment, and it plays an important role in biogeochemical cycling in acid mine drainage (AMD). In this study, an integrated high-throughput absolute abundance quantification (iHAAQ) method was applied to study the dynamics of microbial community and the characteristics of microorganism. The results showed a significant difference in bacterial community with diversity being higher in watershed area. The main influential factors for bacterial communities in watershed were physicochemical properties (e.g., pH and potassium), while in mining areas the main driving factors were metals/metalloids (e.g., As, Zn, and Pb). Notably, the major functions of microbial community were transporter and ABC transporter in mining area, while two-component system was more abundant in watershed by the Kyoto Encyclopedia of Genes and Genomes (KEGG) annotation analysis (level 3). In particular, Phyllobacterium, Bacteroides, and Sulfurovum were demonstrated to be potentially useful bacterial species for bioremediation, which should be a good choice for future studies. These results could facilitate our understanding of microbial diversity in different sediments of mining areas and identify microbial communities for bioremediation projects.

Experimental and theoretical aspects of biochar-supported nanoscale zero-valent iron activating H2O2 for ciprofloxacin removal from aqueous solution.

Ciprofloxacin has been frequently detected in water environment, and its removal has become a significant public concern. Biochar-supported nanoscale zero-valent iron (BC/nZVI) to activate hydrogen peroxide (H2O2) has many advantages on promoting the removal of organic contaminants. In this paper, the BC/nZVI activating H2O2 degradation of ciprofloxacin was systematically investigated by experimental and theoretical approaches. The morphologies and property analysis showed that nZVI particles distributed uniformly on the biochar surface, which mainly include -OH, >CO and COC and CO groups. Different reaction conditions were compared to define the optimal conditions for ciprofloxacin removal in BC/nZVI/H2O2 system. More than 70% of ciprofloxacin was removed in the optimal conditions: acidic condition (pH 3∼4), low doses of H2O2 (20 mM), and temperature of 298 K. The hydroxyl radical (•OH) oxidation was the primary pathway in BC/nZVI/H2O2 degradation of ciprofloxacin process. The theoretical calculation indicated that hydrogen atom abstraction (HAA) pathways were the dominant oxidation pathways contributing 92.3% in overall second‒order rate constants (k) of •OH and ciprofloxacin. The current results are valuable to evaluate the application of BC/nZVI activating H2O2 degradation of ciprofloxacin and other fluoroquinolone antibiotics in water treatment plants.

The Internal Relation between Quantum Chemical Descriptors and Empirical Constants of Polychlorinated Compounds.

Quantum chemical descriptors and empirical parameters are two different types of chemical parameters that play the fundamental roles in chemical reactivity and model development. However, previous studies have lacked detail regarding the relationship between quantum chemical descriptors and empirical constants. We selected polychlorinated biphenyls (PCBs) as an object to investigate the intrinsic correlation between 16 quantum chemical descriptors and Hammett constants. The results exhibited extremely high linearity for ∑ with Qxx/yy/zz, α and EHOMO based on the meta-position grouping. Polychlorinated dibenzodioxins (PCDDs) and polychlorinated naphthalenes (PCNs) congeners, as two independent compounds, validated the reliability of the relationship. The meta-substituent grouping method between ∑ and α was successfully used to predict the rate constant (k) for •OH oxidation of PCBs, as well as the octanol/water partition coefficient (logKOW) and aqueous solubility (-logSW) of PCDDs, and exhibited excellent agreement with experimental measurements. Revealing the intrinsic correlation underlying the empirical constant and quantum chemical descriptors can develop simpler and higher efficient model application in predicting the environmental behavior and chemical properties of compounds.

Effects of red mud based passivator on the transformation of Cd fraction in acidic Cd-polluted paddy soil and Cd absorption in rice.

Highly effective, economical, and replicable ways of Cd-polluted paddy field remediation (in situ) are urgently needed. In this work, a yearlong field experiment (both early and late rice) was conducted to investigate the effects of red mud based passivator [red mud, diatomite, and lime (5:3:2)] on remediation of an acidic Cd-polluted paddy field in Hunan Province. Compared with the control, the addition of red mud based passivator in the early and late rice reduced Cd concentration in each part of the rice plant (with the most significant decrease rate of 59.18% and 72.11% for brown rice in the early rice and late rice seasons respectively). The effect of Cd reduction in the rice plant was persistent in the next growing season. The addition of red mud based passivator also reduced the exchangeable fraction of Cd in the soil and converted the exchangeable fraction into other unavailable fractions. This study demonstrated that the pH in acidic soil increased after the application of red mud based passivator. Furthermore, red mud based passivator had no effect on the concentrations of Olsen-K, Alkaline-N, Olsen-P in the soil, but increased rice grain yield. Overall, the results of this study indicated that the red mud based passivator at 0.6 kg m-2 could be a recommendation for Cd-polluted acidic paddy soil stabilization, and it would be a suitable method for remediation of Cd-polluted acidic paddy soil.

Response of soil microbial communities to red mud-based stabilizer remediation of cadmium-contaminated farmland.

In this work, a field test was conducted to investigate the effects of heavy metal stabilizer addition on brown rice and microbial variables in a cadmium (Cd)-contaminated farmland from April to October in 2016. Compared with the control, red mud-based stabilizer (RMDL) effectively reduced the concentration of Cd in brown rice (with the removal rate of 48.14% in early rice, 20.24 and 47.62% in late rice). The results showed that adding 0.3 kg m-2 RDML in early rice soil or soil for both early and late rice increased the microbial biomass carbon (MBC), the number of culturable heterotrophic bacteria and fungi, and the catalase activity in soil at different stages of paddy rice growth. Furthermore, there was no notable difference in the diversity of the bacterial species, community composition, and relative abundance at phylum (or class) or operational taxonomic unit (OTU) levels between the control and treatment (RMDL addition) groups. In a word, RMDL could be highly recommended as an effective remediation stabilizer for Cd-contaminated farmland, since its continuous application in paddy soil cultivating two seasons rice soil could effectively decrease the Cd content in brown rice and had no negative impact on soil microorganisms.

The study of a pilot-scale aerobic/Fenton/anoxic/aerobic process system for the treatment of landfill leachate.

In this study, a combined aerobic-Fenton-anoxic/aerobic system was designed for the remediation of raw landfill leachate in a pilot-scale experiment. This system included (i) a granular sludge biological oxidation procedure that achieves the accumulation of nitrite nitrogen ([Formula: see text]) under aerobic conditions; (ii) a Fenton process that improves the biodegradability of the biotreated leachate and (iii) an activated sludge biological oxidation component under anoxic and aerobic conditions. Additionally, a shortcut nitrification and denitrification pathway was achieved. The effects of free ammonia, temperature and pH on nitrite accumulation were discussed. The change in the biochemical oxygen demand/chemical oxygen demand ratio of the effluent after shortcut nitrification was also analysed. The microbial community in the reactor were also investigated. The problem of the lack of carbon source in the denitrification process can be solved by the Fenton reagent method. Moreover, it was beneficial to achieving nitrogen removal as well as the more extensive removal of organic matter. The treatment strategy employed in this study exhibited good results and provided the potential practical application for treating landfill leachate.

Metal-free carbon materials-catalyzed sulfate radical-based advanced oxidation processes: A review on heterogeneous catalysts and applications.

In recent years, advanced oxidation processes (AOPs), especially sulfate radical based AOPs have been widely used in various fields of wastewater treatment due to their capability and adaptability in decontamination. Recently, metal-free carbon materials catalysts in sulfate radical production has been more and more concerned because these materials have been demonstrated to be promising alternatives to conventional metal-based catalysts, but the review of metal-free catalysts is rare. The present review outlines the current state of knowledge on the generation of sulfate radical using metal-free catalysts including carbon nanotubes, graphene, mesoporous carbon, activated carbon, activated carbon fiber, nanodiamond. The mechanism such as the radical pathway and non-radical pathway, and factors influencing of the activation of sulfate radical was also be revealed. Knowledge gaps and research needs have been identified, which include the perspectives on challenges related to metal-free catalyst, heterogeneous metal-free catalyst/persulfate systems and their potential in practical environmental remediation.