In-situ synthesis of magnetic iron-chitosan-derived biochar as an efficient persulfate activator for phenol degradation.

Persulfate activation is a forceful method for eliminating organic pollutants from coal chemical wastewater. In this study, an in-situ synthesis method was used to fabricate an iron-chitosan-derived biochar (Fe-CS@BC) nanocomposite catalyst using chitosan as a template. Fe was successfully imprinted into the newly synthesized catalyst. The Fe-CS@BC can activate persulfate to effectively degrade phenol. This point was confirmed by scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. The impact of various parameters on the removal rate was investigated in a single factor experiment. In Fe-CS@BC/PDS system, 95.96% of phenol (significantly higher than the original biochar of 34.33%) was removed within 45 min and 54.39% TOC within 2 h. The system showed superior efficiency over a broad pH value band from 3 to 9 and has a high degradation rate at ambient temperature. Free radical quenching experiment, EPR experiment and LSV experiment confirmed that multiple free radicals (including 1O2, SO4•-, O2•- and •OH) and electron transfer pathway combined to enhance phenol decomposition. Finally, the activation mechanism of persulfate by Fe-CS@BC was proposed to provide logical guidance on the treatment of organic pollutants in coal chemical wastewater.

The Transcriptional Repressor PerR Senses Sulfane Sulfur by Cysteine Persulfidation at the Structural Zn2+ Site in Synechococcus sp. PCC7002.

Cyanobacteria can perform both anoxygenic and oxygenic photosynthesis, a characteristic which ensured that these organisms were crucial in the evolution of the early Earth and the biosphere. Reactive oxygen species (ROS) produced in oxygenic photosynthesis and reactive sulfur species (RSS) produced in anoxygenic photosynthesis are closely related to intracellular redox equilibrium. ROS comprise superoxide anion (O2●-), hydrogen peroxide (H2O2), and hydroxyl radicals (●OH). RSS comprise H2S and sulfane sulfur (persulfide, polysulfide, and S8). Although the sensing mechanism for ROS in cyanobacteria has been explored, that of RSS has not been elucidated. Here, we studied the function of the transcriptional repressor PerR in RSS sensing in Synechococcus sp. PCC7002 (PCC7002). PerR was previously reported to sense ROS; however, our results revealed that it also participated in RSS sensing. PerR repressed the expression of prxI and downregulated the tolerance of PCC7002 to polysulfide (H2Sn). The reporter system indicated that PerR sensed H2Sn. Cys121 of the Cys4:Zn2+ site, which contains four cysteines (Cys121, Cys124, Cys160, and Cys163) bound to one zinc atom, could be modified by H2Sn to Cys121-SSH, as a result of which the zinc atom was released from the site. Moreover, Cys19 could also be modified by polysulfide to Cys19-SSH. Thus, our results reveal that PerR, a representative of the Cys4 zinc finger proteins, senses H2Sn. Our findings provide a new perspective to explore the adaptation strategy of cyanobacteria in Proterozoic and contemporary sulfurization oceans.

Metabolic Reconfiguration Activates Stemness and Immunomodulation of PDLSCs.

Periodontal ligament derived stem cells (PDLSC) are adult multipotent mesenchymal-like stem cells (MSCs) that can induce a promising immunomodulation to interact with immune cells for disease treatment. Metabolic reconfiguration has been shown to be involved in the immunomodulatory activity of MSCs. However, the underlying mechanisms are largely unknown, and it remains a challenging to establish a therapeutic avenue to enhance immunomodulation of endogenous stem cells for disease management. In the present study, RNA-sequencing (RNA-seq) analysis explores that curcumin significantly promotes PDLSC function through activation of MSC-related markers and metabolic pathways. In vitro stem cell characterization further confirms that self-renewal and multipotent differentiation capabilities are largely elevated in curcumin treated PDLSCs. Mechanistically, RNA-seq reveals that curcumin activates ERK and mTOR cascades through upregulating growth factor pathways for metabolic reconfiguration toward glycolysis. Interestingly, PDLSCs immunomodulation is significantly increased after curcumin treatment through activation of prostaglandin E2-Indoleamine 2,3 dioxygenase (PGE2-IDO) signaling, whereas inhibition of glycolysis activity by 2-deoxyglucose (2-DG) largely blocked immunomodulatory capacity of PDLSCs. Taken together, this study provides a novel pharmacological approach to activate endogenous stem cells through metabolic reprogramming for immunomodulation and tissue regeneration.

Efficacy of artificial intelligence-based screening for diabetic retinopathy in type 2 diabetes mellitus patients.

AIM: To explore the efficacy of artificial intelligence (AI)-based screening for diabetic retinopathy (DR) in type 2 diabetes mellitus (T2DM) patients. METHODS: Data were obtained from 549 T2DM patients who visited the Fundus Disease Center at Henan Provincial People's Hospital from 2018/10-2020/09. DR identification and grading were conducted by two retina specialists, EyeWisdom®DSS and EyeWisdom®MCS, with ophthalmologist grading as reference standard, efficacy of EyeWisdom was evaluated according to sensitivity, specificity, positive predictive value, and negative predictive value. RESULTS: Ophthalmologists detected 324 DR cases. Among them, there were 43 of mild non-proliferative DR (NPDR), 79 of moderate NPDR, 61 of severe NPDR, and 141 of proliferative DR (PDR). EyeWisdom®DSS detected 337 DR and EyeWisdom®MCS detected 264 DR. Sensitivity and specificity of EyeWisdom®DSS were 91.0%(95 %CI: 87.3%-93.8%) and 81.3% (95 %CI: 75.5%-86.1%), while EyeWisdom®MCS correctly identified 76.2%(95 %CI: 71.1%-80.7%) of patients with DR and 92.4%(95 %CI: 87.9%-95.4%) of patients without DR. EyeWisdom®DSS showed 76.5%(95 %CI: 69.6%-82.3%) sensitivity and 78.4%(95 %CI: 73.7%-82.5%) specificity for detecting NPDR and 64.5%(95 %CI: 56.0%-72.3%) sensitivity and 93.1%(95 %CI: 90.1%-95.3%) specificity for diagnosing PDR. CONCLUSION: EyeWisdom®DSS is effective in screening for DR, and the accuracy of EyeWisdom®MCS was higher for identifying patients without DR. It is valuable to carry out AI-based DR screening in poorer regions.

Stem cells cardiac patch from decellularized umbilical artery improved heart function after myocardium infarction.

The construction of the high biocompatible biomaterials pretreated with MSC offers a promising strategy to improve the effects of stem cell therapy for the myocardial infarction (MI). However, assembling vascularized three-dimensional (3-D) myocardial tissues remains an enormous challenge. In this study, we optimized the decellularization protocol with the umbilical artery to construct microporous 3-D scaffold which is suitable for the stem cells (SC) proliferation. The SD rats underwent proximal left coronary ligation and a 5-mm diameter microporous SC patch was implanted directly on the infarct area (SC patch group). The LV contractile function, regional myocardial wall compliance, and tissue histology were assessed 4 weeks after patch implantation. The MSC patch integrated to the local heart tissue and the neo-vessels have been observed in the MSC patch. The vessels in the MSC patch were positive for the CD31 (marker for the mature endothelial cells). The left ventricle wall was thicker in the MSC patch group than the control group (p<0.05 vs. empty patch group). And the LVEF has been improved in the MSC patch group than empty patch group (59±6.7% vs. 31±4.5%, p<0.05). CONCLUSIONS: Our results showed that the implantation of the MSC patch improved cardiac contractile function in heart infarction rat model. The construction of artificial tissue from the decellularized umbilical artery and the MSC may open a promising perspective for the tissue therapy for MI.

[Marginal bone loss around tissue level implants in the posterior part of the mandible].

OBJECTIVE: To clarify the related factors of marginal bone loss (MBL) around tissue level implants in the posterior part of the mandible. METHODS: A total of 116 tissue level implants were implanted in the mandibular posterior region of 76 patients. Patients' information, including general characteristics, implant characteristics, implant site characteristics, and prosthesis characteristics, was recorded. Their cone beam computed tomography data were measured immediately after implant placement, 3 months later, and 3 and 12 months after prosthesis loading. The measurement of MBL was conducted by One Volume Viewer software. SPSS 20.0 was used for statistic analysis. RESULTS: Smoking, cortical bone thickness (CBT), collum angle (CA), and implant local sanitation showed significant differences with body mass loss (P<0.05). No significant differences were found among sex, age, length of implant, diameter of implants, implant systems, bone height, prosthesis type, and MBL (P>0.05). CONCLUSION: The risk factors that caused MBL were smoking, thicker CBT, larger CA, and poor implant local sanitation. Among them, poor implant local sanitation had the highest correlation with MBL.