Therapeutic effect of ZnO NPs-polyhexanide-hydrogel on Staphylococcus aureus-induced skin wound infection in mice.

Nanometer zinc oxide (ZnONPs) offers strong antibacterial, wound healing, hemostatic benefits, and UV protection. Additionally, poly(hexamethylene biguanide)hydrochloride (PHMB) is an environmentally friendly polymer with strong bactericidal properties. However, the synergistic effect of the combination of ZnONPs and PHMB has not been previously explored. The purpose of this study is to explore the synergies of ZnONPs and PHMB and the healing efficacy of ZnO NPs-PHMB-hydrogel on skin wounds in mice infected with Staphylococcus aureus. Therefore, the mice were subjected to skin trauma to create a wound model and were subsequently infected with S. aureus, and then divided into various experimental groups. The repair effect was evaluated by assessing the healing rate, as well as measuring the levels of TNF-α, IL-2, EGF, and TGF-ß1 contents in the tissue. On the 4th and 9th days post-modeling, the Z-P group exhibited notably higher healing rates compared to the control group. However, on the 15th day, both the Z-P and AC groups achieved healing rates exceeding 99%. ZnO NPs-PHMB-hydrogel promoted the formation of a fully restored epithelium, increased new hair follicles and sebaceous glands beneath the epidermis, and markedly reduced inflammatory cell infiltration, which was markedly distinct from the control group. On the 7th day, the Z-P group exhibited significantly higher levels of EGF and TGF-ß1, along with a considerable reduction in the TNF-α levels as compared with the control group. These results affirmed that ZnO NPs-PHMB-hydrogel effectively inhibits S. aureus infection and accelerates skin wound healing.

The circadian clock gene, BMAL1, promotes radiosensitization in nasopharyngeal carcinoma by inhibiting the epithelial-to-mesenchymal transition via the TGF-ß1/Smads/Snail1 axis.

Acquired radio-resistance is thought to be one of the main causes of recurrent metastasis after failure of nasopharyngeal carcinoma (NPC) radiotherapy, which may be related to X-ray-induced epithelial-mesenchymal transition (EMT) activation. The circadian clock gene, BMAL1, has been shown to correlate with the sensitivity of NPCs to radiotherapy, but the specific mechanism has not been reported. NPC cells were irradiated by conventional fractionation to generate radiotherapy-resistant cells. NPC cells with BMAL1 gene stabilization/overexpression and interference were obtained by lentiviral transfection. Western blotting, colony formation analysis, cell counting kit-8 assays, wound-healing tests, Transwell assays, flow cytometry, the EDU method, nuclear plasma separation experiments, HE staining, immunohistochemical staining and TUNEL staining were performed to explore the influence and molecular mechanism of the circadian clock gene, BMAL1, on NPC-acquired radio-resistance and EMT through in vitro and in vivo experiments. The results indicated that there was a gradual downregulation of BMAL1 gene protein expression during the routine dose induction of radio-resistance in NPC cells. EMT activation was present in the radiation-resistant cell line 5-8FR, and was accompanied by the significant enhancement of proliferation, migration and invasion. The BMAL1 gene significantly increased the radiosensitivity of the radiation-resistant cell line 5-8FR and reversed the acquired radio-resistance of NPCs, which was accomplished by inhibiting the TGF-ß1/Smads/Snail1 axis-mediated EMT.

Spinal cord and brain atrophy patterns in neuromyelitis optica spectrum disorder and multiple sclerosis.

BACKGROUND: Spinal cord and brain atrophy are common in neuromyelitis optica spectrum disorder (NMOSD) and relapsing-remitting multiple sclerosis (RRMS) but harbor distinct patterns accounting for disability and cognitive impairment. METHODS: This study included 209 NMOSD and 304 RRMS patients and 436 healthy controls. Non-negative matrix factorization was used to parse differences in spinal cord and brain atrophy at subject level into distinct patterns based on structural MRI. The weights of patterns were obtained using a linear regression model and associated with Expanded Disability Status Scale (EDSS) and cognitive scores. Additionally, patients were divided into cognitive impairment (CI) and cognitive preservation (CP) groups. RESULTS: Three patterns were observed in NMOSD: (1) Spinal Cord-Deep Grey Matter (SC-DGM) pattern was associated with high EDSS scores and decline of visuospatial memory function; (2) Frontal-Temporal pattern was associated with decline of language learning function; and (3) Cerebellum-Brainstem pattern had no observed association. Patients with CI had higher weights of SC-DGM pattern than CP group. Three patterns were observed in RRMS: (1) DGM pattern was associated with high EDSS scores, decreased information processing speed, and decreased language learning and visuospatial memory functions; (2) Frontal-Temporal pattern was associated with overall cognitive decline; and (3) Occipital pattern had no observed association. Patients with CI trended to have higher weights of DGM and Frontal-Temporal patterns than CP group. CONCLUSION: This study estimated the heterogeneity of spinal cord and brain atrophy patterns in NMOSD and RRMS patients at individual level, and evaluated the clinical relevance of these patterns, which may contribute to stratifying participants for targeted therapy.

Distinguishing nitroimidazoles from nitrofurans via luminescence sensing.

Similarity of nitroimidazole and nitrofuran antibiotics in molecular structure and photophysical properties makes them difficult to distinguish via luminescence sensing technology. Herein, this is solved by a dye-encapsulated lanthanide metal-organic framework luminescent sensor.

Real-world experience of teriflunomide in relapsing multiple sclerosis: paramagnetic rim lesions may play a role.

Objectives: The aims of this study were to report the effectiveness and safety of teriflunomide in Chinese patients with relapsing-remitting multiple sclerosis (RRMS) and to explore the association of paramagnetic rim lesion (PRL) burden with patient outcome in the context of teriflunomide treatment and the impact of teriflunomide on PRL burden. Methods: This is a prospective observational study. A total of 100 RRMS patients treated with teriflunomide ≥3 months were included in analyzing drug persistence and safety. Among them, 96 patients treated ≥6 months were included in assessing drug effectiveness in aspects of no evidence of disease activity (NEDA) 3. The number and total volume of PRL were calculated in 76 patients with baseline susceptibility-weighted imaging (SWI), and their association with NEDA3 failure during teriflunomide treatment was investigated. Results: Over a treatment period of 19.7 (3.1-51.7) months, teriflunomide reduced annualized relapse rate (ARR) from 1.1 ± 0.8 to 0.3 ± 0.5, and Expanded Disability Status Scale (EDSS) scores remained stable. At month 24, the NEDA3% and drug persistence rate were 43.8% and 65.1%, respectively. In patients with a baseline SWI, 81.6% had at least 1 PRL, and 42.1% had ≥4 PRLs. The total volume of PRL per patient was 0.3 (0.0-11.5) mL, accounting for 2.3% (0.0%-49.0%) of the total T2 lesion volume. Baseline PRL number ≥ 4 (OR = 4.24, p = 0.009), younger onset age (OR = 0.94, p = 0.039), and frequent relapses in initial 2 years of disease (OR = 13.40, p = 0.026) were associated with NEDA3 failure. The PRL number and volume were not reduced (p = 0.343 and 0.051) after teriflunomide treatment for more than 24 months. No new safety concerns were identified in this study. Conclusion: Teriflunomide is effective in reducing ARR in Chinese patients with RRMS. Patients with less PRL burden, less frequent relapses, and relatively older age are likely to benefit more from teriflunomide, indicating that PRL might be a valuable measurement to inform clinical treatment decision.

Efficient Escorting Strategy for Aggregation-Prone Notch EGF Repeats with Sparcl1.

Epidermal growth factor (EGF) repeats are present in various proteins and form well-defined structures with three disulfide bonds. One representative protein is the Notch receptor. Each EGF repeat contains unique atypical O-linked glycans, such as O-linked N-acetylglucosamine (O-GlcNAc). To generate a monoclonal antibody against the O-GlcNAc moiety in mouse Notch1, we expressed the recombinant C-terminal His6-tagged Notch1 EGF14-15 protein in HEK293T cells to prepare the immunogen. Most of the proteins were not secreted and showed higher molecular weight ladders in the cell lysate, suggesting protein aggregation. To overcome this issue, we fused Sparcl1 as an extracellular escorting tag to the N-terminus of Notch1 EGF14-15. The fusion protein was efficiently secreted extracellularly without protein aggregates in the lysates. Following PreScission protease treatment, Notch1 EGF14-15 was efficiently released from the escorting tag. Notch1 EGF14-15 prepared using this method was indeed O-GlcNAcylated. The optimal length of the escorting tag was determined by generating deletion mutants to improve the extracellular secretion of EGF14-15. Hence, a large amount of EGF14-15 was successfully prepared from the culture supernatant of HEK293T cells, which were otherwise prone to aggregation.

Precise reconstruction of the entire mouse kidney at cellular resolution.

The kidney is an important organ for excreting metabolic waste and maintaining the stability of the body's internal environment. The renal function involves multiple complex and fine structures in the whole kidney, and any change in these structures may cause impaired nephric function. Consequently, achieving three-dimensional (3D) reconstruction of the entire kidney at a single-cell resolution is of significant importance for understanding the kidney's structural characteristics and exploring the pathogenesis of kidney diseases. In this paper, we propose a pipeline from sample preparation to optical microscopic imaging of the entire kidney, followed by data processing for 3D reconstruction of the whole mouse kidney. We employed transgenic fluorescent labeling and propidium iodide (PI) labeling to obtain detailed information about the vascular structure and cytoarchitecture of the kidney. Subsequently, the entire mouse kidney was imaged at submicron-resolution using high-definition fluorescent micro-optical sectioning tomography (HD-fMOST). Finally, we reconstructed the structures of interest through various data processing methods on the original images. This included detecting glomeruli throughout the entire kidney, as well as the segmentation and visualization of the renal arteries, veins, and three different types of nephrons. Our method provides a powerful tool for studying the renal microstructure and its spatial relationships throughout the entire kidney.

Dual Function of Naphthalenediimide Supramolecular Photocatalyst with Giant Internal Electric Field for Efficient Hydrogen and Oxygen Evolution.

Organic supramolecular photocatalysts have garnered widespread attention due to their adjustable structure and exceptional photocatalytic activity. Herein, a novel bis-dicarboxyphenyl-substituent naphthalenediimide self-assembly supramolecular photocatalyst (SA-NDI-BCOOH) with efficient dual-functional photocatalytic performance is successfully constructed. The large molecular dipole moment and short-range ordered stacking structure of SA-NDI-BCOOH synergistically create a giant internal electric field (IEF), resulting in a remarkable 6.7-fold increase in its charge separation efficiency. Additionally, the tetracarboxylic structure of SA-NDI-BCOOH greatly enhances its hydrophilicity. Thus, SA-NDI-BCOOH demonstrates efficient dual-functional activity for photocatalytic hydrogen and oxygen evolution, with rates of 372.8 and 3.8 µmol h-1 , respectively. Meanwhile, a notable apparent quantum efficiency of 10.86% at 400 nm for hydrogen evolution is achieved, prominently surpassing many reported supramolecular photocatalysts. More importantly, with the help of dual co-catalysts, it exhibits photocatalytic overall water splitting activity with H2 and O2 evolution rates of 3.2 and 1.6 µmol h-1 . Briefly, this work sheds light on enhancing the IEF by controlling the molecular polarity and stacking structure to dramatically improve the photocatalytic performance of supramolecular materials.

An oncolytic vaccinia virus encoding hyaluronidase reshapes the extracellular matrix to enhance cancer chemotherapy and immunotherapy.

BACKGROUND: The redundant extracellular matrix (ECM) within tumor microenvironment (TME) such as hyaluronic acid (HA) often impairs intratumoral dissemination of antitumor drugs. Oncolytic viruses (OVs) are being studied extensively for cancer therapy either alone or in conjunction with chemotherapy and immunotherapy. Here, we designed a novel recombinant vaccinia virus encoding a soluble version of hyaluronidase Hyal1 (OVV-Hyal1) to degrade the HA and investigated its antitumor effects in combination with chemo drugs, polypeptide, immune cells, and antibodies. METHODS: We constructed a recombinant oncolytic vaccinia virus encoding the hyaluronidase, and investigated its function in remodeling the ECM of the TME, the antitumor efficacy both in vitro and in several murine solid tumors either alone, or in combination with chemo drugs including doxorubicin and gemcitabine, with polypeptide liraglutide, with immune therapeutics such as PD-L1/PD-1 blockade, CD47 antibody, and with CAR-T cells. RESULTS: Compared with control OVV, intratumoral injection of OVV-Hyal1 showed superior antitumor efficacies in a series of mouse subcutaneous tumor models. Moreover, HA degradation by OVV-Hyal1 resulted in increased intratumoral dissemination of chemo drugs, infiltration of T cells, NK cells, macrophages, and activation of CD8+ T cells. When OVV-Hyal1 was combined with some antitumor therapeutics, for example, doxorubicin, gemcitabine, liraglutide, anti-PD-1, anti-CD47 blockade, or CAR-T cells, more profound therapeutic outcomes were obtained. CONCLUSIONS: OVV-Hyal1 effectively degrades HA to reshape the TME, therefore overcoming some major hurdles in current cancer therapy, such as limited OVs spread, unfavored dissemination of chemo drugs, polypeptides, antibodies, and insufficient infiltration of effector immune cells. OVV-Hyal1 holds the promise to improve the antitumor outcomes of current cancer therapeutics.

Interpretable and Intuitive Machine Learning Approaches for Predicting Disability Progression in Relapsing-Remitting Multiple Sclerosis Based on Clinical and Gray Matter Atrophy Indicators.

RATIONALE AND OBJECTIVES: To investigate whether clinical and gray matter (GM) atrophy indicators can predict disability in relapsing-remitting multiple sclerosis (RRMS) and to enhance the interpretability and intuitiveness of a predictive machine learning model. MATERIALS AND METHODS: 145 and 50 RRMS patients with structural MRI and at least 1-year follow-up Expanded Disability Status Scale (EDSS) results were retrospectively enrolled and placed in the discovery and external test cohorts, respectively. Six clinical and radiomics feature-based machine learning classifiers were trained and tested to predict disability progression in the discovery cohort and validated in the external test set. Partial dependence plot (PDP) analysis and a Shiny web application were conducted to enhance the interpretability and intuitiveness. RESULTS: In the discovery cohort, 98 patients had disability stability, and 47 patients were classified as having disability progression. In the external test set, 35 patients were disability stable, and 15 patients had disability progression. Models trained with both clinical and radiomics features (area under the curve (AUC), 0.725-0.950) outperformed those trained with clinical (AUC, 0.600-0.740) or radiomics features only (AUC, 0.615-0.945). Among clinical+ radiomics feature models, the logistic regression (LR) classifier-based model performed best, with an AUC of 0.950. Only the radiomics feature-only models were applied in the external test set due to the data collection problem and showed fair performance, with AUCs ranging from 0.617 to 0.753. PDP analysis showed that female patients and those with lower volume, surface area, and symbol digit modalities test (SDMT) scores; greater mean curvature and age; and no disease modifying therapy (DMT) had increased probabilities of disease progression. Finally, a Shiny web application (https://lauralin1104.shinyapps.io/LRshiny/) was developed to calculate the risk of disability progression. CONCLUSION: Interpretable and intuitive machine learning approaches based on clinical and GM atrophy indicators can help physicians predict disability progression in RRMS patients for clinical decision-making and patient management.

From "resistance genes expression" to "horizontal migration" as well as over secretion of Extracellular Polymeric Substances: Sludge microorganism's response to the increasing of long-term disinfectant stress.

Glutaraldehyde-Didecyldimethylammonium bromides (GDs) has been frequently and widely employed in livestock and poultry breeding farms to avoid epidemics such as African swine fever, but its long-term effect on the active sludge microorganisms of the receiving wastewater treatment plant was keep unclear. Four simulation systems were built here to explore the performance of aerobic activated sludge with the long-term exposure of GDs and its mechanism by analyzing water qualities, resistance genes, extracellular polymeric substances and microbial community structure. The results showed that the removal rates of CODCr and ammonia nitrogen decreased with the exposure concentration of GDs increasing. It is worth noting that long-term exposure to GDs can induce the horizontal transfer and coordinated expression of a large number of resistance genes, such as qacE, sul1, tetx, and int1, in drug-resistant microorganisms. Additionally, it promotes the secretion of more extracellular proteins, including arginine, forming a "barrier-like" protection. Therefore, long-term exposure to disinfectants can alter the treatment capacity of activated sludge receiving systems, and the abundance of resistance genes generated through horizontal transfer and coordinated expression by drug-resistant microorganisms does pose a significant threat to ecosystems and health. It is recommended to develop effective pretreatment methods to eliminate disinfectants.

Knittable Electrochemical Yarn Muscle for Morphing Textiles.

Morphing textiles, crafted using electrochemical artificial muscle yarns, boast features such as adaptive structural flexibility, programmable control, low operating voltage, and minimal thermal effect. However, the progression of these textiles is still impeded by the challenges in the continuous production of these yarn muscles and the necessity for proper structure designs that bypass operation in extensive electrolyte environments. Herein, a meters-long sheath-core structured carbon nanotube (CNT)/nylon composite yarn muscle is continuously prepared. The nylon core not only reduces the consumption of CNTs but also amplifies the surface area for interaction between the CNT yarn and the electrolyte, leading to an enhanced effective actuation volume. When driven electrochemically, the CNT@nylon yarn muscle demonstrates a maximum contractile stroke of 26.4%, a maximum contractile rate of 15.8% s-1, and a maximum power density of 0.37 W g-1, surpassing pure CNT yarn muscles by 1.59, 1.82, and 5.5 times, respectively. By knitting the electrochemical CNT@nylon artificial muscle yarns into a soft fabric that serves as both a soft scaffold and an electrolyte container, we achieved a morphing textile is achieved. This textile can perform programmable multiple motion modes in air such as contraction and sectional bending.

Research progress on ethnobotany, phytochemistry, pharmacological action, and applications of Engelhardia roxburghiana Wall: a review.

OBJECTIVES: Engelhardia roxburghiana Wall is a plant of the Juglandaceae family, and its leaves is the main part used as a medicine. It is used to relieve heat and pain, gasification, and dampness. The purpose of this review is to provide a systematic review about the botany, traditional uses, phytochemistry, pharmacology, and toxicology of this plant. KEY FINDINGS: Many compounds have been isolated and identified from the plant, including flavonoids, triterpenoids, steroids, quinones, essential oils, and other types of chemical constituents. Extensive pharmacological activities of the extracts or compounds of E. roxburghiana Wall in vivo and in vitro were mainly confirmed, including anti-cancer, anti-diabetic, anti-inflammatory, and anti-allergic effects. SUMMARY: In this paper, the botany, traditional uses, phytochemistry, and pharmacology of E. roxburghiana Wall were reviewed. In the future, E. roxburghiana Wall needs further study, such as paying more attention to quality control and the utilization on agriculture. In addition, discussing the medicinal components of decoction as well as the toxicity will also contribute to the progress of clinical trial studies.

Genome-wide identification of the expansin gene family in netted melon and their transcriptional responses to fruit peel cracking.

Introduction: Fruit cracking not only affects the appearance of netted melons (Cucumis melo L. var. reticulatus Naud.) but also decreases their marketability. Methods: Herein, to comprehensively understand the role of expansin (EXP) proteins in netted melon, bioinformatics methods were employed to discover the EXP gene family in the melon genome and analyze its characteristic features. Furthermore, transcriptomics analysis was performed to determine the expression patterns of melon EXP (CmEXP) genes in crack-tolerant and crack-susceptible netted melon varieties. Discussion: Thirty-three CmEXP genes were identified. Chromosomal location analysis revealed that CmEXP gene distribution was uneven on 12 chromosomes. In addition, phylogenetic tree analysis revealed that CmEXP genes could be categorized into four subgroups, among which the EXPA subgroup had the most members. The same subgroup members shared similar protein motifs and gene structures. Thirteen duplicate events were identified in the 33 CmEXP genes. Collinearity analysis revealed that the CmEXP genes had 50, 50, and 44 orthologous genes with EXP genes in cucumber, watermelon, and Arabidopsis, respectively. However, only nine orthologous EXP genes were observed in rice. Promoter cis-acting element analysis demonstrated that numerous cis-acting elements in the upstream promoter region of CmEXP genes participate in plant growth, development, and environmental stress responses. Transcriptomics analysis revealed 14 differentially expressed genes (DEGs) in the non-cracked fruit peels between the crack-tolerant variety 'Xizhoumi 17' (N17) and the crack-susceptible variety 'Xizhoumi 25' (N25). Among the 14 genes, 11 were upregulated, whereas the remaining three were downregulated in N17. In the non-cracked (N25) and cracked (C25) fruit peels of 'Xizhoumi 25', 24 DEGs were identified, and 4 of them were upregulated, whereas the remaining 20 were downregulated in N25. In the two datasets, only CmEXPB1 exhibited consistently upregulated expression, indicating its importance in the fruit peel crack resistance of netted melon. Transcription factor prediction revealed 56 potential transcription factors that regulate CmEXPB1 expression. Results: Our study findings enrich the understanding of the CmEXP gene family and present candidate genes for the molecular breeding of fruit peel crack resistance of netted melon.

Dickkopf-1 is an immune infiltration-related prognostic biomarker of head and neck squamous cell carcinoma.

Immunotherapy is currently one of the most viable therapies for head and neck squamous cell carcinoma (HNSCC), characterized by high immune cell infiltration. The Wnt-signaling inhibitor and immune activation mediator, Dickkopf-1 (DKK1), has a strong correlation with tumor growth, tumor microenvironment, and, consequently, disease prognosis. Nevertheless, it is still unclear how DKK1 expression, HNSCC prognosis, and tumor-infiltrating lymphocytes are related. To better understand these associations, we examined how DKK1 expression varies across different tumor and normal tissues. In our study, we investigated the association between DKK1 mRNA expression and clinical outcomes. Next, we assessed the link between DKK1 expression and tumor immune cell infiltration. Additionally, using immunohistochemistry, we evaluated the expression of DKK1 in 15 healthy head and neck tissue samples, and the expression of CD3, CD4, and DKK1 in 27 HNSCC samples. We also explored aberrant DKK1 expression during tumorigenesis. DKK1 expression was remarkably higher in HNSCC tissues than in healthy tissues, and was shown to be associated with tumor stage, grade, lymph node metastasis, histology, and a dismal clinical prognosis in HNSCC. DKK1 expression in HNSCC tissues was inversely correlated with CD3+ (P < 0.0001) and CD4+ (P < 0.0001) immune cell infiltration, while that in immune cells was inversely associated with HNSCC prognosis. These findings offer a bioinformatics perspective on the function of DKK1 in HNSCC immunotherapy and provide justification for clinical research on DKK1-targeted HNSCC treatments. DKK1 is a central target for improving the efficacy of HNSCC immunotherapy.

High-purity monoclinic pyrrhotite derived from natural pyrite with excellent removal performance for Cr (VI) and its mechanism.

Pyrrhotite, especially the monoclinic type, is a promising material for removing Cr (VI) from wastewater and groundwater due to its high reactivity. However, the purity of the preparation monoclinic pyrrhotite from heated natural pyrite is not high enough, and the role of possible sulfur vacancies in pyrrhotite's crystal structure has been largely ignored in the removal mechanism of Cr (VI). In this work, we characterized the phase composition changes of annealed pyrite in inert gas and prepared high-purity (~ 96%) monoclinic pyrrhotite at the optimal condition. We found that it could remove 18.6 mg/g of Cr (VI) by redox reaction, which is the best value reported of natural pyrite-derived materials so far. As the reactive media material of simulated permeable reactive barrier, the service life of the high-purity monoclinic pyrrhotite column is 297 PV, which is much longer than that of the pyrite column (50 PV). A new founding is that S2- and S vacancy play the essential role during the redox reaction of pyrrhotite and Cr (VI). Monoclinic pyrrhotite had more S vacancy than hexagonal pyrrhotite and pyrite, which explained its superior Cr (VI) removal performance.

Micro-aeration and low influent C/N are key environmental factors for achieving ANAMMOX in livestock farming wastewater treatment plants.

Anaerobic ammonium oxidation (ANAMMOX)-mediated system is a cost-effective green nitrogen removal process. However, there are few examples of successful application of this advanced wastewater denitrification process in wastewater treatment plants, and the understanding of how to implement anaerobic ammonia oxidation process in full-scale is still limited. In this study, it was found that the abundance of anaerobic ammonia-oxidizing bacteria (AnAOB) in the two livestock wastewater plants named J1 and J2, respectively, showed diametrically opposed trends of waxing and waning with time. The microbial communities of the activated sludge in the two plants at different time were sampled and analyzed by high-throughput sequencing of 16S rRNA genes. Structural equation models (SEMs) were used to reveal the key factors affecting the realization of the ANAMMOX. Changes in the concentration of dissolved oxygen and C/N had a significant effect on the relative abundance of anaerobic ammonia oxidation bacteria (AnAOB). The low concentration of DO (0.2∼0.5 mg/L) could inhibit the activity of nitrifying bacteria (NOB) to achieve partial oxidation of ammonia nitrogen and provide sufficient substrate for the growth of AnAOB, similar to the CANON (Completely Autotrophic Nitrogen removal Over Nitrite). Unlike CANON, heterotrophic denitrification is also a particularly critical part of the livestock wastewater treatment, and a suitable C/N of about 0.6 could reduce the competition risk of heterotrophic microorganisms to AnAOB and ensure a good ecological niche for AnAOB. Based on the results of 16S rRNA and microbial co-occurrence networks, it was discovered that microorganisms in the sludge not only had a richer network interaction, but also achieved a mutually beneficial symbiotic interaction network among denitrifying bacteria (Pseudomonas sp., Terrimonas sp., Dokdonella sp.), AnAOB (Candidatus Brocadia sp.) at DO of 0.2∼0.5 mg/L and C/N of 0.6. Among the top 20 in abundance of genus level, AnAOB had a high relative abundance of 27.66%, followed by denitrifying bacteria of 3.67%, AOB of 0.64% and NOB of 0.26%, which is an essential indicator for the emergence of an AnAOB-dominated nitrogen removal cycle. In conclusion, this study highlights the importance of dissolved oxygen and C/N regulation by analyzing the mechanism of ANAMMOX sludge extinction and growth in two plants under anthropogenic regulation of AnAOB in full-scale wastewater treatment systems.

Can digital transformation change a firm's green innovation strategy? Evidence from China's heavily polluting industries.

Enterprises are facing the superimposed challenges of digitalization and greening. The shift from reactive green technology innovation (RGT) to proactive green technology innovation (PGT) has special significance for sustainable economic development. Which strategies will companies choose? Can digital transformation (DT) motivate companies to transform their green innovation strategies? Enterprises' green innovation strategy choices must be explained with regard to digitalization. The purpose of this paper is to reveal how digitalization affects the choice of green innovation strategies and to provide a realistic basis for the sustainable development of heavily polluting enterprises. We formulated a "DT-capability-strategy" theoretical framework incorporating external constraints and internal attitudes to empirically test the microdata of 505 heavily polluting enterprises. The results show that: (1) DT can shift the heavily polluting enterprises' green innovation strategies from RGT to PGT. Endogenous tests and robustness tests support this conclusion. (2) A mechanism test shows that environmental regulations cannot significantly regulate a green innovation strategy. Only a company's capabilities and attitudes can influence PGT but their effects on RGT are not statistically significant. (3) The influence of DT on green innovation strategies shows multi-dimensional heterogeneity in the digital infrastructure, scale, and innovation level of the enterprise. The conclusions provide implications for enterprises to integrate their digital and green behaviors.