Efficient degradation of m-cresol during catalytic wet peroxide oxidation with biochar derived from the pyrolysis of persulfate-ZVI treated sludge.

Sludge dewatering is crucial for cutting the cost of sludge post-disposal in wastewater treatment plants. Response surface methodology (RSM) was used in this study to sufficiently investigate the interaction among persulfate, zero-valent iron (ZVI) and reaction time on the sludge dewatering. Under the experimental condition at the central point in RSM, the sludge moisture content was reduced to 54%. The sludge-based biochar obtained from the pyrolysis of persulfate-ZVI treated sludge at the central point in RSM was marked as SC-M and tested for catalytic activity. With the catalyst SC-M, the removal rates of m-cresol and total organic carbon (TOC) were 98.1% and 84.2%, respectively. The persulfate-ZVI treatment for sludge dewatering facilitated increasing the proportion of iron species in SC-M, which contributed to its high catalytic activity. M-cresol degradation with SC-M was a two-period reaction including an induction period and a rapid reaction with the apparent activation energy at a low level. This study integrates the sludge dewatering by persulfate-ZVI treatment and m-cresol degradation by catalytic oxidation with the biochar SC-M prepared from the dewatered iron-rich sludge, providing an effective, economic and environment-friendly approach for sewage sludge utilization and management.

Molecular insights into the catalytic oxidation of methanol-to-olefins wastewater with phosphoric acid modified sludge biochar.

With the development of methanol-to-olefin (MTO) process, the effective disposal of wastewater was one key factor for the long-period and benign development of this technology. Herein, a sludge-based biochar catalyst (GSC-P) was synthesized and used in photo-Fenton reaction for the degradation of MTO wastewater from the outlet of a biological aerated filter. More iron was distributed on the surface of GSC-P catalyst, facilitating the photo-Fenton oxidation of MTO wastewater, with chemical oxygen demand (COD) removal rate of 75.4% and total organic carbon (TOC) removal rate of 62.5%. The 2223 unique molecular formulas assigned by a Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) in the original MTO wastewater showed that CHO compounds shared the lowest peak numbers (20.2%) but the highest peak abundance (51.6%) among the four groups. Besides, lipids, unsaturated hydrocarbons, lignins and proteins were the main structural types. After photo-Fenton treatment of 60 min, there were 56.7%-74.0% of compounds removed by the analysis of van Krevelen diagram, indicating that the MTO wastewater was degraded efficiently. Three possible evolution processes of dissolved organic matters during the photo-Fenton reaction were disclosed at the molecular-level.

Silencing Gene-Engineered Injectable Hydrogel Microsphere for Regulation of Extracellular Matrix Metabolism Balance.

Extracellular matrix (ECM) metabolism balance is essential for maintaining tissue structure and function. However, the complex crosstalk between the ECM, resident cellular, and tissue microenvironment makes long-term maintenance of ECM metabolism balance in an abnormal microenvironment difficult to achieve. Herein, an injectable circRNA silencing-hydrogel microsphere (psh-circSTC2-lipo@MS) is constructed by grafting circSTC2 silencing genes-loaded 1,2-dioleoyl-3-trimethylammonium-propane/cholesterol/1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOTAP/Chol/DOPE) cationic liposomes on methacrylated hyaluronic acid (HAMA) microspheres via amide bonds, which could silence pathological genes in nucleus pulposus (NP) cells to regulate ECM metabolism balance in the nutrient-restricted microenvironment, thereby inhibiting intervertebral disc (IVD) degeneration. HAMA microspheres prepared by microfluidics displayed good degradability, swellability, and injectability. And lipoplexes can be efficiently loaded and released for 27 d through chemical grafting. Cocultured under nutrient-restricted conditions for 72 h, psh-circSTC2-lipo@MS significantly promotes the synthesis of ECM-related proteins and inhibits the secretion of ECM catabolism-related proteases in NP cells. In the rat IVD nutrient-restricted model, local injection of psh-circSTC2-lipo@MS promotes ECM synthesis and restored NP tissue after 8 weeks. In summary, this study confirms that psh-circSTC2-lipo@MS as a safe and controllable targeted gene delivery system has great potential in regulating the ECM metabolism balance under an abnormal microenvironment.

Comprehensive Profile Analysis of Differentially Expressed circRNAs in Glucose Deprivation-Induced Human Nucleus Pulposus Cell Degeneration.

Nucleus pulposus (NP) is the core substance to maintain the homeostasis of intervertebral disc and stability of biomechanics. The insufficient supply of nutrition (especially glucose) is an important factor that leads to the degeneration of NP cells. circRNAs play an important role in the process of intervertebral disc degeneration (IDD) by regulating the functions of NP cells. However, glucose deprivation-related circRNAs and their functions in IDD have not been reported. In this study, the differentially expressed circRNAs in NP cells after 0, 6, 12, and 24 h of glucose deprivation culture were detected by a microarray assay. Besides, time series clustering analysis by STEM software obtained the differentially up- and downregulated circRNAs during glucose deficiency. Then, the main functions and pathways of up- and downregulated circRNAs were predicted by the functional enrichment analysis. By constructing the circRNA-miRNA regulatory network, the potential mechanisms of the most differentially expressed circRNAs were predicted. In addition, according to in vitro validation, circ_0075062 was upregulated in degenerating NP tissues and glucose deprivation-induced NP cell degeneration. Based on Sanger sequencing and RNase tolerance assay, circ_0075062 was the circular transcript. Interfering with circ_0075062 expression could potentially alleviate the imbalance of extracellular matrix (ECM) synthesis and degradation in the NP cells induced by glucose deprivation. Together, these findings help us gain a comprehensive understanding of the underlying mechanisms of IDD, and circ_0075062 may be a promising therapeutic target of IDD.

Integrating multiple microarray dataset analysis and machine learning methods to reveal the key genes and regulatory mechanisms underlying human intervertebral disc degeneration.

Intervertebral disc degeneration (IDD), a major cause of lower back pain, has multiple contributing factors including genetics, environment, age, and loading history. Bioinformatics analysis has been extensively used to identify diagnostic biomarkers and therapeutic targets for IDD diagnosis and treatment. However, multiple microarray dataset analysis and machine learning methods have not been integrated. In this study, we downloaded the mRNA, microRNA (miRNA), long noncoding RNA (lncRNA), and circular RNA (circRNA) expression profiles (GSE34095, GSE15227, GSE63492 GSE116726, GSE56081 and GSE67566) associated with IDD from the GEO database. Using differential expression analysis and recursive feature elimination, we extracted four optimal feature genes. We then used the support vector machine (SVM) to make a classification model with the four optimal feature genes. The ROC curve was used to evaluate the model's performance, and the expression profiles (GSE63492, GSE116726, GSE56081, and GSE67566) were used to construct a competitive endogenous RNA (ceRNA) regulatory network and explore the underlying mechanisms of the feature genes. We found that three miRNAs (hsa-miR-4728-5p, hsa-miR-5196-5p, and hsa-miR-185-5p) and three circRNAs (hsa_circRNA_100723, hsa_circRNA_104471, and hsa_circRNA_100750) were important regulators with more interactions than the other RNAs across the whole network. The expression level analysis of the three datasets revealed that BCAS4 and SCRG1 were key genes involved in IDD development. Ultimately, our study proposes a novel approach to determining reliable and effective targets in IDD diagnosis and treatment.

The Therapeutic Evaluation of Spinal Canal Decompression by Using the TBEIS Technique in the Treatment of Lumbar Spinal Stenosis.

OBJECTIVE: To evaluate the clinical efficacy of the percutaneous endoscopic Transforaminal Broad Easy Immediate Surgery (TBEIS) technology in elderly patients with lumbar spinal stenosis (LSS). METHODS: From February 2016 to May 2018, 35 elderly patients with LSS were treated with the TBEIS technique. There were 23 males and 12 females, aged from 53 to 72 years with a median age of 63.1 years. Preoperative, 1 day, and 1 and 12 months postoperative visual analogue scale (VAS) scores and Oswestry Disability Index (ODI) were statistically analyzed. The modified MacNab criterion was used to assess the clinical effects. The radiological outcomes were evaluated by X-ray and computed tomography (CT). RESULTS: All of the operations were successful. The operative time ranged from 120 to 170 min with a median time of 148 min. All of the patients were followed up for 12 to 38 months with a median follow-up of 18 months. Preoperative, 1 day, and 1 and 12 months postoperative VAS leg scores were 6.91 ± 0.98, 1.69 ± 0.68, 1.23 ± 0.59, and 0.91 ± 0.61, respectively, and the VAS back scores improved from 4.51 ± 0.82 to 0.66 ± 0.68. The ODI scores were 63.82 ± 7.59, 38.79 ± 6.36, 24.79 ± 3.90, and 11.33 ± 3.92, respectively. Postoperative scores of VAS and ODI were obviously improved (P < 0.01). According to the modified MacNab criteria used to evaluate the clinical effects, 11 cases achieved excellent results, 18 cases achieved good results, 4 cases achieved fair results, and 2 cases achieved poor results. There were no neurovascular injury and other complications. CONCLUSIONS: Treatment of LSS in the elderly patients by the TBEIS technology has good clinical efficacy, and the technique is safe and minimally invasive.

Cell-seeded porous silk fibroin scaffolds promotes axonal regeneration and myelination in spinal cord injury rats.

Accumulating evidence indicates that a suitable scaffold designed for the spinal cord injury (SCI) was needed to enhance the survival of transplanted Bone mesenchymal stem cells (BMSCs) and to promote nerve regeneration. The current study was aimed to evaluate the effect of the porous silk fibroin scaffold (PSFSs) seeded with BMSCS on nerve regeneration, myelination and functional recovery after SCI. We previously demonstrated that the PSFSs could bridge defected nerve with nerve fibers when applied to the transected spinal cord. And we found that BMSCs were adhered to the scaffold closely and have good biological compatibility with PSFSs. PSFSs seeded with BMSCs exhibited significant improvement in complete transverse thoracic SCI rat models. Flow cytometric assay also indicated that BMSCs grew well and adhered closely to the surface of the scaffold. The Basso-Beattie-Bresnehan (BBB) scores at each time point showed that the hindlimb motor function of each transplant group was also significantly restored. Meanwhile, growth associated protein 43 (GAP-43)marker of damaged axons regeneration and myelin basic protein (MBP) marker of maintaining the myelin structural and functional integrity, all markedly increased in PSFSs seeded with BMSCs models. Together, these results demonstrated that transplantation of PSFSs seeded with BMSCS could promote the nerve regeneration, myelination and functional recovery after SCI.

Transfer RNA-derived fragments as potential exosome tRNA-derived fragment biomarkers for osteoporosis.

AIM: Osteoporosis is one of the common orthopedic diseases featured in low bone mineral density. Exosomes have been proven to be potential markers for many diseases and health problems. The roles of messenger RNAs and microRNAs in osteoporosis have been comprehensively studied; however, little research has focused on the function of plasma exosomal transfer RNA-derived fragments (tRFs) in osteoporosis. METHODS: We collected plasma samples from 40 healthy controls and 40 osteoporosis patients, and all exosomes were isolated with combined centrifugation and were characterized by electron microscopy. Small RNA sequence (Yingbio) was performed to detect the plasma exosomal tRFs and tRF markers were validated by real-time quantitative polymerase chain reaction (qPCR). Three exosome diagnostic tRFs were confirmed by receiver operating characteristic analyses. RESULTS: In this study, 11 upregulated tRFs and 18 downregulated tRFs were identified in osteoporosis compared with normal controls. Higher expression levels of plasma exosomal tRF-25-R9ODMJ6B26 (tRF-25), tRF-38-QB1MK8YUBS68BFD2 (tRF-38), tRF-18-BS68BFD2 (tRF-18) in osteoporosis were confirmed by qPCR. Plasma exosomal tRF-25, tRF-38 and tRF-18 showed better accuracy for osteoporosis diagnosis. CONCLUSION: Our results suggest that plasma exosomal tRF-25, tRF-38 and tRF-18 might be diagnostic biomarkers for osteoporosis detection.

Early-stage autophagy protects nucleus pulposus cells from glucose deprivation-induced degeneration via the p-eIF2α/ATF4 pathway.

Autophagy is a double-edged sword in cellular survival, but its effects on nucleus pulposus (NP) cells are yet to be clarified. This study explored the role and molecular mechanisms of autophagy in the survival of NP cells under nutrient deprivation. Glucose limitation induced time-dependent morphological changes, proteoglycan degradation, and apoptosis in NP cells. Glucose deprivation triggered the activation of early-stage autophagy, evident as increases in LC3-II and ATG12-ATG5 expression and the number of GFP-LC3 puncta. Importantly, at early time points, the autophagy inhibitor 3-MA significantly enhanced the apoptosis of NP cells, suggesting that early-stage autophagy protects cells against glucose deprivation. Interestingly, the p-eIF2α/ATF4 unfolded protein response pathway was activated in NP cells deprived of glucose, and a deficiency in ATF4 attenuated the activation of early-stage autophagy and increased apoptosis. ATF4 silencing also inhibited the late-stage accumulation of reactive oxygen species (ROS) and apoptosis. Together, our results demonstrate an interplay between endoplasmic reticulum stress, ROS production, and the early-stage autophagy induced by glucose deprivation in NP cells. These findings may provide a therapeutic strategy for the treatment of degenerative intervertebral disc disease.