Publications by authors named "Mingming Guo"

77 Publications

Prognostic value of gamma-interferon-inducible lysosomal thiol reductase expression in female patients diagnosed with breast cancer.

Int J Cancer 2021 Oct 14. Epub 2021 Oct 14.

Department of Breast Surgery, The Second Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China.

Because of the high heterogeneity of breast cancer outcome, identification of novel prognostic biomarkers is critical to improve patient stratification and guide precise treatment. We examined the prognostic value of gamma-interferon-inducible lysosomal thiol reductase (GILT) expression in a training set of 416 breast cancer patients and a validation set of 210 patients, and performed functional studies to investigate the functions and underlying mechanisms of GILT on breast cancer prognosis. Our results indicated that high GILT expression in breast cancer cells was associated with improved disease-free survival (DFS; hazard ratio [HR] = 0.189, 95% confidence interval [CI]: 0.099-0.361) and breast cancer-specific survival (BCSS; HR = 0.187, 95% CI: 0.080-0.437) of breast cancer patients both in the training set and the external validation set (HR = 0.453, 95% CI: 0.235-0.873 for DFS, HR = 0.488, 95% CI: 0.245-0.970 for BCSS). In vitro and in vivo studies showed that GILT overexpression inhibited breast cancer cells proliferation, invasion, migration and tumor formation in nude mice and increased sensitivity of breast cancer cells to standard treatment. Proteomics analysis indicated that GILT inhibited reactive oxygen species (ROS) and autophagy activation in breast cancer cells, and GILT overexpression-mediated tumor growth was further enhanced in the presence of autophagy or ROS inhibitors. Our results demonstrate that GILT expression can be effectively used to predict the prognosis and guide treatment strategies of breast cancer patients.
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http://dx.doi.org/10.1002/ijc.33843DOI Listing
October 2021

Emerging chitosan-essential oil films and coatings for food preservation - A review of advances and applications.

Carbohydr Polym 2021 Dec 28;273:118616. Epub 2021 Aug 28.

College of Biosystems Engineering and Food Science, National-Local Joint Engineering Laboratory of Intelligent Food Technology and Equipment, Zhejiang Key Laboratory for Agro-Food Processing, Zhejiang R & D Center for Food Technology and Equipment, Fuli Institute of Food Science, Ningbo Research Institute, Zhejiang University, Hangzhou 310058, China. Electronic address:

With the rising demand for fresh and ready-to-eat foods, antimicrobial packaging has been developed to control or prevent microbial growth as well as maintain food quality and safety. Chitosan is an advanced biomaterial for antimicrobial packaging to meet the growing needs of safe and biodegradable packaging. The application of natural essential oils as antimicrobial agents effectively controls the growth of spoilage and pathogenic microbes. Thus, chitosan edible coatings and films incorporated with essential oils have expanded the general applications of antimicrobial packaging in food products. This review summarized the effect of essential oils on modifying the physicochemical characteristics of chitosan-based films. Notably, the antimicrobial efficacy of the developed composite films or coatings was highlighted. The advances in the preparation methods and application of chitosan films were also discussed. Broadly, this review will promote the potential applications of chitosan-essential oils composite films or coatings in antimicrobial packaging for food preservation.
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http://dx.doi.org/10.1016/j.carbpol.2021.118616DOI Listing
December 2021

Effect of combination therapy with neural stem cell transplantation and teramethylpyrazine in rats following acute spinal cord injury.

Neuroreport 2021 11;32(16):1311-1319

Department of Orthopaedics, The General Hospital of Northern Theater Command, Shenyang.

Objectives: This study was to explore the effects of teramethylpyrazine (TMP) administered in conjunction with neural stem cell transplantation on motor function, pathological lesions and the Janus kinase (JAK)2/signal transducer and activator of transcription 3 signal transduction pathway in rats following acute spinal cord injury (SCI).

Methods: Female Sprague-Dawley rats were randomly divided into sham, model, neural stem cells (NSCs) and NSCs+TMP groups. Motor function was evaluated using the Basso, Beattie, Bresnahan scale. Spinal cord neuropathies and neuron apoptosis were observed by HE and TUNEL staining. The brain-derived neurotrophic factor (BDNF), Nogo-A, JAK2 and p-JAK2 protein levels were measured by western blot analysis.

Results: NSCs+TMP significantly improved rat motor function, attenuated impaired spinal cords, and decreased cellular apoptosis, compared with NSCs therapy alone (P < 0.05). In addition, expression of BDNF protein was significantly higher in NSCs+TMP rats compared with other groups regardless of time postinjury (P < 0.05). The highest expression levels of Nogo-A protein were observed in the model group. The expression of p-JAK2 in the NSCs+TMP group was relatively lower than the model and NSCs groups (P < 0.05).

Conclusions: In rats with SCI, NSCs+TMP effectively improved motor function and offered spinal cord protection by increasing BDNF and decreasing Nogo-A levels, as well as inhibiting the JAK2/STAT3 signal transduction pathway, suggesting that TMP could be a useful agent in NSCs transplantation in the treatment of SCI.
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http://dx.doi.org/10.1097/WNR.0000000000001725DOI Listing
November 2021

Nanoarmour-shielded single-cell factory for bacteriotherapy of Parkinson's disease.

J Control Release 2021 10 10;338:742-753. Epub 2021 Sep 10.

Academy of Medical Engineering and Translational Medicine, Tianjin Key Laboratory of Brain Science and Neural Engineering, Xincheng Hospital of Tianjin University, Tianjin University, Tianjin 300072, China; Healthina Academy of Cellular Intelligence Manufacturing & Neurotrauma Repair, Beijing Tangyi Huikang Biomedical Technology Co., Ltd, Beijing 100010, China. Electronic address:

Cell-based therapy for Parkinson's disease (PD) is a novel and promising approach in recent years. However, exogenous cells are easy to be captured and destroyed by the harsh environment in vivo, so their application prospects have been severely limited. Here, a facile yet versatile approach for decorating individual living cells with nano-armor coatings is reported. By simply self-assembly with liposome under a cyto-compatible condition, the lipid bimolecular coating on the surface of each cell acts as armor to effectively protect it from the attack and destruction of strong acids and digestive enzymes during the oral treatment of PD. Our results demonstrated that the liposome coated B. adolescentis (LCB) could significantly improve the colonization rate in the intestinal tract. LCB, as a living cell factory, can self-regulate to produce a constant concentration of γ-aminobutyric acid and maintain a longer half-life for the treatment of PD. Then, we also explored the specific mechanism of LCB to improve the behavior of murine models of PD, including abating inflammatory effects, reducing neuronal apoptosis, regulating the activity of dopaminergic neurons and microglia. The simple nano-armor shielded single-cell factory can produce neurotransmitters-like drugs on demand in vivo, introducing novel strategies of integration of producing and using to the research of drug delivery field.
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http://dx.doi.org/10.1016/j.jconrel.2021.09.009DOI Listing
October 2021

CRISPR/Cas9 nanoeditor of double knockout large fragments of E6 and E7 oncogenes for reversing drugs resistance in cervical cancer.

J Nanobiotechnology 2021 Aug 5;19(1):231. Epub 2021 Aug 5.

School of Life Sciences, Tianjin University, 92 Weijin Road, Nankai, 300072, Tianjin, China.

Drug resistance of tumor cells is always a headache problem in clinical treatment. In order to combat chemotherapy-resistance in cervical cancer and improve treatment effect, we design a CRISPR/Cas9 nanoeditor to knock out two key oncogenes E6 and E7 that lead to drug tolerance. Meanwhile, the deletion of these two oncogenes can effectively reactivate p53 and pRB signaling pathways that inhibit the growth of tumor cells. Our results demonstrated the nanoeditor could simultaneously delete two oncogenes, and the size of DNA fragments knocked out reaches an unprecedented 563 bp. After the preparation of cationic liposomes combined with chemotherapy drug docetaxel (DOC), this nanosystem can significantly inhibit the drug tolerance of cancer cells and improve the therapeutic effect of cervical cancer. Therefore, this study provides a promising strategy for the treatment of cervical cancer by combining chemotherapy and double-target gene therapy. This strategy can also be applied in other disease models to customize personalized anti-tumor strategies by simply changing chemotherapy drugs and targeted genes.
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http://dx.doi.org/10.1186/s12951-021-00970-wDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8340365PMC
August 2021

Informative and corrective responsive packaging: Advances in farm-to-fork monitoring and remediation of food quality and safety.

Compr Rev Food Sci Food Saf 2021 09 27;20(5):5258-5282. Epub 2021 Jul 27.

College of Biosystems Engineering and Food Science, National-Local Joint Engineering Laboratory of Intelligent Food Technology and Equipment, Zhejiang Key Laboratory for Agro-Food Processing, Integrated Research Base of Southern Fruit and Vegetable Preservation Technology, Zhejiang International Scientific and Technological Cooperation Base of Health Food Manufacturing and Quality Control, Zhejiang University, Hangzhou, China.

Microbial growth and fluctuations in environmental conditions have been shown to cause microbial contamination and deterioration of food. Thus, it is paramount to develop reliable strategies to effectively prevent the sale and consumption of contaminated or spoiled food. Responsive packaging systems are designed to react to specific stimuli in the food or environment, such as microorganisms or temperature, then implement an informational or corrective response. Informative responsive packaging is aimed at continuously monitoring the changes in food or environmental conditions and conveys this information to the users in real time. Meanwhile, packaging systems with the capacity to control contamination or deterioration are also of great interest. Encouragingly, corrective responsive packaging attempting to mitigate the adverse effects of condition fluctuations on food has been investigated. This packaging exerts its effects through the triggered release of active agents by environmental stimuli. In this review, informative and corrective responsive packaging is conceptualized clearly and concisely. The mechanism and characteristics of each type of packaging are discussed in depth. This review also summarized the latest research progress of responsive packaging and objectively appraised their advantages. Evidently, the mechanism through which packaging systems respond to microbial contamination and associated environmental factors was also highlighted. Moreover, risk concerns, related legislation, and consumer perspective in the application of responsive packaging are discussed as well. Broadly, this comprehensive review covering the latest information on responsive packaging aims to provide a timely reference for scientific research and offer guidance for presenting their applications in food industry.
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http://dx.doi.org/10.1111/1541-4337.12807DOI Listing
September 2021

Integration of transcriptomic and proteomic approaches unveils the molecular mechanism of membrane disintegration in Escherichia coli O157:H7 with ultrasonic treatment.

Sci Total Environ 2021 Oct 9;791:148366. Epub 2021 Jun 9.

College of Biosystems Engineering and Food Science, National-Local Joint Engineering Laboratory of Intelligent Food Technology and Equipment, Zhejiang Key Laboratory for Agro-Food Processing, Integrated Research Base of Southern Fruit and Vegetable Preservation Technology, Zhejiang International Scientific and Technological Cooperation Base of Health Food Manufacturing and Quality Control, Fuli Institute of Food Science, Zhejiang University, Hangzhou 310058, China; Ningbo Research Institute, Zhejiang University, Ningbo 315100, China. Electronic address:

Ultrasonic disinfection in wastewater treatment has been studied for years at the phenotypic level, while the understanding of the molecular inactivation mechanism is still not clear. Here, the responses of Escherichia coli O157:H7 to ultrasound treatment were investigated using RNA sequencing (RNA-Seq) and tandem mass tags (TMT) based quantitative proteomics methods. The analyses revealed that 770 genes and 201 proteins were significantly changed upon ultrasound treatment. Moreover, the integrated transcriptomic and proteomic analyses uncovered a set of 59 genes or proteins were differentially expressed in ultrasound-treated cells, providing an overview of the cellular responses to ultrasonic field. According to the bioinformatic analyses, genes and proteins that may be involved in lipid asymmetry preservation and outer membrane homeostasis maintenance (including phospholipid metabolism, lipopolysaccharide biosynthesis and transport, and fatty acid metabolism) were specifically up-regulated. Therefore, we proposed that the metabolism disorder of cellular membrane lipids (lipopolysaccharide, phospholipid, and fatty acid included) was one of the main challenges for the bacteria upon ultrasonic stress. In this study, we initially proposed a novel mechanism regarding the ultrasound-induced membrane disintegration from a multi-omics perspective, which may present an important step toward deciphering the molecular inactivation mechanism of ultrasonic field and provide a theoretical foundation for the application of ultrasound technology for the control of waterborne pathogens.
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http://dx.doi.org/10.1016/j.scitotenv.2021.148366DOI Listing
October 2021

High-intensity ultrasound processing of baobab fruit pulp: Effect on quality, bioactive compounds, and inhibitory potential on the activity of α-amylase and α-glucosidase.

Food Chem 2021 Nov 18;361:130144. Epub 2021 May 18.

Department of Food Science and Nutrition, Zhejiang Key Laboratory for Agro-Food Processing, Zhejiang University, Hangzhou, Zhejiang, China; Fuli Institute of Food Science, Ningbo Research Institute, Zhejiang University, China. Electronic address:

Effect of high-intensity ultrasound (HIU) compared with thermal treatments on baobab fruit pulp (BFP) quality and bioactive properties were investigated. HIU treatments, particularly at intensities of 687.5 W/cm for 5 min, and 344 W/cm for 15 min significantly (p < 0.05) increased the cloudiness index, ascorbic acid (AA) retention, total phenolic and flavonoid contents, and antioxidant capacity besides a more potent α-amylase and α-glucosidase inhibition relative to thermally treated samples. Moreover, the physicochemical parameters, colour index, and browning index were maintained with HIU besides lower 5-hydroxymethylfurfural values than thermal processing. HPLC analysis revealed that the content of most phenolic compounds was the highest in HIU treatments besides a 235-256% increase in procyanidin C compared with control samples. The AA retention following HIU treatments was 87.62-102.86% compared to 30.47-61.90% in thermally treated samples. Our analyses portrayed ultrasound as a feasible alternative to conventional thermal processing of BFP.
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http://dx.doi.org/10.1016/j.foodchem.2021.130144DOI Listing
November 2021

Significantly Red-Shifted Emissions of Nonconventional AIE Polymers Containing Zwitterionic Components.

Macromol Rapid Commun 2021 Jul 5;42(14):e2100174. Epub 2021 May 5.

School of Chemistry and Chemical Engineering, Southwest University, Chongqing, 400715, China.

Nonconventional luminescence polymers without any aromatic structures have attracted great interest from researchers due to their special structure and excellent biocompatibility. However, these materials mostly emit in the blue or green region, in which preparation of materials with long-wavelength (especially near-infrared) emission is still a great challenge. In this work, it is found that 2-(dimethyl amino) ethyl methacrylate (DMA) and itaconic anhydride (ITA) undergo a ring-opening reaction at room temperature, and subsequently generate zwitterionic compound (IDMA). Based on the clustering-triggered emission (CTE) mechanism, ionic bond can effectively promote the isolated electron-rich chromophores to form new emissive clusters with extended electron delocalization. Herein, two oligomers (P1 and P2) with different fluorescence emissions by controlling the concentration of zwitterionic monomers before polymerization are synthesized. It is worth noting that the maximum emission wavelength of P2 at high concentration is up to 712 nm, which is very rare in previous reports. In addition, the resulting oligomer (P2) shows typical aggregation-enhanced emission (AEE), excitation-dependent fluorescence, temperature-sensitive emission, and solvatochromism. The cytotoxicity assay demonstrates that P2 was low toxic to Huh7 and LM3 cells, and suitable for cell imaging. This research provides the possibility for rational molecular design and the feasibility of luminescence regulation.
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http://dx.doi.org/10.1002/marc.202100174DOI Listing
July 2021

Sendai virus-based immunoadjuvant in hydrogel vaccine intensity-modulated dendritic cells activation for suppressing tumorigenesis.

Bioact Mater 2021 Nov 13;6(11):3879-3891. Epub 2021 Apr 13.

Academy of Medical Engineering and Translational Medicine, Tianjin Key Laboratory of Brain Science and Neural Engineering, Tianjin University, 92 Weijin Road, Nankai District, Tianjin, 300072, China.

The conventional immunoadjuvants in vaccine have weak effect on stimulating antigen presentation and activating anti-tumor immunity. Unexpectedly, we discovered that non-pathogenic Sendai virus (SeV) could activate antigen-presenting cells (APCs) represented by dendritic cells (DCs). Here, we designed an injectable SeV-based hydrogel vaccine (SHV) to execute multi-channel recruitment and stimulation of DCs for boosting the specific immune response against tumors. After the release of the NIR-triggered antigens from tumor cells, dendritic cells around the vaccine efficiently transport the antigens to lymph nodes and present them to T lymphocytes, thereby inducing systemic anti-tumor immune memory. Our findings demonstrated that the SHV with excellent universality, convenience and flexibility has achieved better immune protection effects in inhibiting the occurrence of melanoma and breast cancer. In conclusion, the SHV system might serve as the next generation of personalized anti-tumor vaccines with enhanced features over standard vaccination regimens, and represented an alternative way to suppress tumorigenesis.
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http://dx.doi.org/10.1016/j.bioactmat.2021.04.002DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8076650PMC
November 2021

Apple Juice Preservation Using Combined Nonthermal Processing and Antimicrobial Packaging.

J Food Prot 2021 09;84(9):1528-1538

Fuli Institute of Food Science, Zhejiang University, Hangzhou 310058, People's Republic of China.

Abstract: This study was conducted to investigate the effectiveness of pulsed electric fields (PEFs), pulsed UV light (PL), and antimicrobial packaging (AP), either individually or combined, for inactivating bacteria and maintaining the quality of fruit juices. Apple juice samples were inoculated with Escherichia coli K-12 or native molds and yeasts (M&Y), treated with bench-scale PEF and/or PL processing systems, and stored in glass jars with antimicrobial caps containing 10 μL of carvacrol. The reductions in microbial populations and the physicochemical properties of juice samples were determined after treatments and during storage at 10°C. The treatments were PL (5 to 50 s at 1.04 J/cm2/s), PEF (19, 23, and 30 kV/cm), PEF followed by PL (PEF+PL), PL followed by PEF (PL+PEF), and PEF+PL+AP. PEF treatments at 19 to 30 kV/cm (PEF19, PEF23, and PEF30) resulted in 2.0-, 2.6-, and 4.0-log reductions of E. coli, respectively, and PL treatments for 10 to 50 s (PL10, PL20, PL30, PL40, and PL50) resulted in 0.45-, 0.67-, 0.76-, 2.3-, and 4.0-log reductions, respectively. No significant differences (P > 0.05) were found between the combined PL20+PEF19 and PEF19+PL20 treatments; both treatments reduced E. coli K-12 populations to nondetectable levels (>5-log reductions) after 7 days. Both PEF+PL and PEF+PL+AP treatments achieved >5-log reductions of M&Y; however, juice samples subjected to PEF+PL+AP treatment had lower M&Y counts (2.9 log units) than did samples subjected to PEF+PL treatment (3.9 log units) after 7 days. No significant differences (P > 0.05) in pH, acidity, and total soluble solids were found among all samples after treatments. Increased PL treatment times reduced color a* and b* values, total phenolics, and carotenoids. This study provides information valuable to juice processors for consideration and design of nonthermal pasteurization of juice products.

Highlights:
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http://dx.doi.org/10.4315/JFP-21-035DOI Listing
September 2021

Uptake, Accumulation, Translocation, and Subcellular Distribution of Perchlorate in Tea ( L.) Plants.

J Agric Food Chem 2021 Apr 15;69(16):4655-4662. Epub 2021 Apr 15.

Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou 310008, China.

Perchlorate, emerging pollution with thyroid toxicity, has a high detection rate in fresh tea leaves. What needs attention is that the uptake characteristic is insufficiently understood. Herein, the uptake, accumulation, and translocation of perchlorate in a tea plant-hydroponic solution system were investigated, of which the mechanism was further lucubrated by subcellular distribution. The perchlorate concentration in tea tissues is ramped up along with the increase in the exposure level and time. The bioaccumulation factor of tea tissues followed the rank: mature leaves > tender leaves > roots. After the seedlings have been transplanted to a perchlorate-free solution, the perchlorate in mature leaves is reduced significantly, accompanied by a progressive increase in perchlorate in new shoots and solutions. The cell-soluble fractions are the major reservoir of perchlorate both for roots (>59%) and leaves (>76%), which precisely explained the translocation within the tea plant-hydroponic solution system. These results not only illuminate the uptake characteristic in tea plants but also improve the understanding of the behavior of perchlorate in higher plants.
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http://dx.doi.org/10.1021/acs.jafc.1c01270DOI Listing
April 2021

NIR-Responsive Spatiotemporally Controlled Cyanobacteria Micro-Nanodevice for Intensity-Modulated Chemotherapeutics in Rheumatoid Arthritis.

ACS Appl Mater Interfaces 2021 Apr 13;13(16):18423-18431. Epub 2021 Apr 13.

Academy of Medical Engineering and Translational Medicine, Tianjin University, 92 Weijin Road, Nankai District, Tianjin 300072, P. R. China.

The expression of hypoxia-inducible factor-1α (HIF-1α) is upregulated in hypoxic environments at the lesions of rheumatoid arthritis (RA), which promoted the polarization of proinflammatory M1 macrophages and inhibited the differentiation of anti-inflammatory M2 to deteriorate synovial inflammation. Since oxygen scarcity at the joints causes an imbalance of macrophages M1 and M2, herein, we designed a cyanobacteria micro-nanodevice that can be spatiotemporally controlled in vivo to continuously producing oxygen in the RA joints for the downregulation of the expression of HIF-1α, thereby reducing the amounts of M1 macrophages and inducing the polarization of M2 macrophages for chemically sensitized RA treatment. The forthputting of temperature-sensitive hydrogel guaranteed the safety of cyanobacteria micro-nanodevice in vivo. Furthermore, the oxygen produced by cyanobacteria micro-nanodevice in a sustained manner enhanced the therapeutic effect of the antirheumatic drug methotrexate (MTX) and discouraged inflammation and bone erosion at RA. This study provided a new approach for the RA treatment of spatiotemporal-controlled release of oxygen in vitro.
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http://dx.doi.org/10.1021/acsami.0c20514DOI Listing
April 2021

Revegetation induced change in soil erodibility as influenced by slope situation on the Loess Plateau.

Sci Total Environ 2021 Jun 3;772:145540. Epub 2021 Feb 3.

State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Water and Soil Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Yangling, Shaanxi 712100, PR China.

Soil erodibility is an indispensable parameter for predicting soil erosion and evaluating the benefits of soil and water conservation. Slope situation can alter revegetation and its effects on soil properties and root traits, and thus may affect soil erodibility. However, whether slope situation will change the effect of revegetation on soil erodibility through improving soil properties and root traits has rarely been evaluated. Therefore, this study was conducted to detect the response of soil erodibility to slope situations (loess-tableland, hill-slope and gully-slope) in a typical watershed of the Loess Plateau. Five soil erodibility parameters (saturated soil hydraulic conductivity, SHC; mean weight diameter of aggregates, MWD; clay ratio, CR; soil disintegration rate, SDR; soil erodibility factor, K) and a comprehensive soil erodibility index (CSEI) are selected to clarify the study targets. The results revealed that soil properties, root traits, soil erodibility parameters and CSEI were affected by slope situation significantly. Soil and root can explain 79.7%, 79.1% and 69.8% of total variance in soil erodibility of loess-tableland, hill-slope and gully-slope, respectively. Slope situation influenced soil erodibility by changing the effects of revegetation on soil properties and root traits. Evidently, the slope situation greatly changed the relations between CSEI and soil and root parameters, whereafter a model considering slope situation (slope steepness), sand, organic matter content and root surface area density was reliable to estimate soil erodibility (CSEI). Our study suggested that the Armeniaca sibirica, the combination of Bothriochloa ischcemum and Robinia pseudoacacia and the combination of Armeniaca sibirica and Lespedeza bicolor can be used as the optimal selection for mitigating soil erodibility of loess-tableland, hill-slope and gully-slope, respectively. This study is of great significance in optimizing the spatial layout of soil and water conservation measures for different slope situations of the Loess Plateau.
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http://dx.doi.org/10.1016/j.scitotenv.2021.145540DOI Listing
June 2021

Inhalable nanovaccine with biomimetic coronavirus structure to trigger mucosal immunity of respiratory tract against COVID-19.

Chem Eng J 2021 Aug 19;418:129392. Epub 2021 Mar 19.

Academy of Medical Engineering and Translational Medicine, Tianjin Key Laboratory of Brain Science and Neural Engineering, Tianjin University, 92 Weijin Road, Nankai District, Tianjin 300072, PR China.

The COVID-19 pandemic caused by SARS-CoV-2 seriously threatens global public health. It has previously been confirmed that SARS-CoV-2 is mainly transmitted between people through "respiratory droplets". Therefore, the respiratory tract mucosa is the first barrier to prevent virus invasion. It is very important to stimulate mucosal immunity to protect the body from respiratory virus infection. Inspired by this, we designed a bionic-virus nanovaccine, which can induce mucosal immunity by nasal delivery to prevent virus infection from respiratory tract. The nanovaccine that mimic virosome is composed of poly(I:C) mimicking viral genetic material as immune adjuvant, biomimetic pulmonary surfactant (bio-PS) liposomes as capsid structure of virus and the receptor binding domains (RBDs) of SARS-CoV-2 as "spike" to completely simulate the structure of the coronavirus. The nanovaccine can be administered by inhaling to imitate the process of SARS-CoV-2 infection through the respiratory tract. Our results demonstrated that the inhalable nanovaccine with bionic virus-like structure has a stronger mucosal protective effect than routine muscle and subcutaneous inoculation. In particular, high titer of secretory immunoglobulin A (sIgA) was detected in respiratory secretions, which effectively neutralize the virus and prevent it from entering the body through the respiratory tract. Through imitating the structure and route of infection, this inhalable nanovaccine strategy might inspire a new approach to the precaution of respiratory viruses.
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http://dx.doi.org/10.1016/j.cej.2021.129392DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7972832PMC
August 2021

Improved catalytic oxidation of propylene glycol methyl ether over Sm-Mn and Sm-Co perovskite-based catalysts prepared by the recycling of spent ternary lithium-ion battery.

Environ Sci Pollut Res Int 2021 Aug 20;28(29):38829-38838. Epub 2021 Mar 20.

School of Chemistry and Chemical Engineering, Nantong University, 9, Seyuan Road, Jiangsu Province, Nantong, 226019, China.

The spent ternary lithium-ion batteries were utilized as the precursors to prepare Sm-Mn and Sm-Co perovskite oxides (SmMnO-spent ternary lithium-ion battery [STLIB] and SmCoO-STLIB) for the first time. Their catalytic activities were evaluated by catalytic oxidation of propylene glycol methyl ether. Compared with that of the catalysts synthesized by analytical reagents, the catalytic activities of SmMnO-STLIB and SmCoO-STLIB had been significantly enhanced. The analysis of X-ray photoelectron spectroscopy (XPS) showed that the molar ratios of Mn/Mn and O/O of SmMnO-STLIB were higher than that of pure SmMnO and the Co/Co ratios of SmCoO-STLIB was much larger than that of pure SmCoO. The hydrogen temperature-programmed reduction (H-TPR) and N adsorption-desorption tests determined that the reducibilities and specific surface areas of SmMnO-STLIB and SmCoO-STLIB were also superior to pure catalysts. Ultimately, the by-products of the catalytic oxidation of propylene glycol methyl ether over SmMnO-STLIB were also detected by gas chromatography-mass spectrometry (GC-MS). This work will provide a demonstration for the resource utilization of spent lithium ions batteries and the analysis of the increased activity obtained by using spent lithium ions batteries as the precursors to prepare catalysts.
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http://dx.doi.org/10.1007/s11356-021-13497-2DOI Listing
August 2021

Antibacterial mechanism of ultrasound against Escherichia coli: Alterations in membrane microstructures and properties.

Ultrason Sonochem 2021 May 2;73:105509. Epub 2021 Mar 2.

College of Biosystems Engineering and Food Science, National-Local Joint Engineering Laboratory of Intelligent Food Technology and Equipment, Zhejiang Key Laboratory for Agro-Food Processing, Integrated Research Base of Southern Fruit and Vegetable Preservation Technology, Zhejiang International Scientific and Technological Cooperation Base of Health Food Manufacturing and Quality Control, Zhejiang University, Hangzhou 310058, China; Fuli Institute of Food Science, Zhejiang University, Hangzhou 310058, China; Ningbo Research Institute, Zhejiang University, Ningbo 315100, China. Electronic address:

This study was aimed at providing new insights on the response of bacterial cell membranes to ultrasound exposure. Escherichia coli (E. coli) O157:H7 cells were exposed to different ultrasound treatments (power intensities of 64, 191, 372, and 573 W/cm, frequency of 20 kHz, pulsed mode of 2 sec: 2 sec) and the dynamic changes in cell viability within 27 min were assessed. With an increase in ultrasonic intensity and prolonged duration, a 0.76-3.52 log CFU/mL reduction in E. coli populations was attained. The alterations in the sensitivity of ultrasound-treated cells to antimicrobial compounds were evaluated by exposure to thyme essential oil nanoemulsion (TEON). The treatment reduced the E. coli population by 2.16-7.10 log CFU/mL, indicating the effects of ultrasonic field on facilitating the antibacterial efficacy of TEON. Ultrasonic-treated E. coli cells also displayed remarkable morphological and ultrastructural damages with destroyed membrane integrity and misshaped cell structures, which was observed by electron microscopy analysis. Significant increase in outer and inner membrane permeability, along with the cytoplasmic leakage and membrane depolarization were assessed utilizing spectrophotometry. For the first time, significant reduction in the membrane fluidity in response to ultrasound exposure were investigated. Additional efforts in exploring the effect of ultrasonic field on some bacterial membrane compositions were performed with infrared spectroscopy. In this study, multiple lines of evidence effectively served to elucidate the alterations on cellular membrane structure and property during exposure to sonication that could extend our understanding of the antimicrobial molecular mechanisms of ultrasound.
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http://dx.doi.org/10.1016/j.ultsonch.2021.105509DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7941012PMC
May 2021

Spent lithium-ion battery materials recycling for catalytic pyrolysis or gasification of biomass.

Bioresour Technol 2021 Mar 28;323:124584. Epub 2020 Dec 28.

School of Environmental Science and Engineering, Shanghai Jiao Tong University (SJTU), 800 Dongchuan Rd., Shanghai 200240, China; Shanghai Engineering Research Center of Solid Waste Treatment and Resource Recovery, Shanghai 200240, China.

This research work studied the pyrolysis characteristics of main biomass components (i.e. cellulose, lignin) in the presence of the spent Li-ion battery cathode (BC) enriched in transition-metals (e.g., Ni, Co). The BC with a good thermostability even at > 700 °C could be used as a catalyst for biomass conversion. The addition methods of BC to biomass such as one-step (directly mixing) and two-step (impregnation-drying) were comparatively studied. The two-step method had a better catalytic effect in biomass pyrolysis, contributing to the reduction of decomposition temperature and activation energy. Significantly, the two-step method had a strong catalytic effect in reducing the content of cellulose-derived sugars and increasing the content of ketones via dehydration and decarboxylation. In addition, the BC used by the two-step method had a high potential for biomass pyrolysis or gasification in promoting the catalytic cracking (i.e. H-transfer) of lignin-derived phenols (tar surrogates) to hydrocarbons and aliphatics (e.g., ketones).
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http://dx.doi.org/10.1016/j.biortech.2020.124584DOI Listing
March 2021

Residue behavior and safety evaluation of pymetrozine in tea.

J Sci Food Agric 2021 Aug 3;101(10):4118-4124. Epub 2021 Feb 3.

Center of Agricultural Product Safety, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, China.

Background: Pymetrozine is a widely used pesticide. It is challenging to analyze and difficult to manage due to the large gap in its global maximum residue limits (MRLs) in tea. The development of a high-efficiency detection method for the evaluation of the transfer of residual pymetrozine from tea plantations to tea cups is therefore of prime significance.

Results: An analytical method for the determination of pymetrozine residues in tea was established based on Cleanert PCX solid-phase extraction. The average recoveries were 72.2-93.7%, with relative standard deviations (RSDs) of less than 12%. The limits of quantification (LOQs) were 0.005 mg·kg in fresh tea leaves and dry tea, and 0.00025 mg·L in tea brew. Pymetrozine degraded rapidly in tea plants with a half-life (t ) of 1.9 days in open tea plantations, and decreased by 9.4-23.7% in the green tea-processing procedure, which was concentration dependent. The residual pymetrozine levels in green tea collected at 6 and 21 days were below the MRLs in China and EU at a dosage of 30 g a.i. ha , respectively. The leaching rates of pymetrozine from dry tea to tea brew were 58.7-96.3%. Hazard quotient (HQ) values of pymetrozine were significantly <100% when tea shoots were plucked in 6 days, which indicated a negligible risk to humans.

Conclusion: This work allows the determination of residual pymetrozine in tea and illustrates a low intake risk with the use of pymetrozine in tea plantations. It could serve as reference for further regulation consideration for maximum residue limits (MRLs). © 2020 Society of Chemical Industry.
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http://dx.doi.org/10.1002/jsfa.11047DOI Listing
August 2021

Synthesis of MnO derived from spent lithium-ion batteries via advanced oxidation and its application in VOCs oxidation.

J Hazard Mater 2021 Mar 2;406:124743. Epub 2020 Dec 2.

School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dong Chuan Road, Shanghai 200240, PR China; Shanghai Engineering Research Center of Solid Waste Treatment and Resource Recovery, Shanghai 200240, PR China. Electronic address:

In this work, manganese is selectively and efficiently recovered from spent lithium-ion batteries via advanced oxidation by using potassium permanganate and ozone, and the transition metal-doped α-MnO and β-MnO are one-step prepared for catalytic oxidation of VOCs. The recovery rate of manganese can be approximately 100% while the recovery efficiency of cobalt, nickel, and lithium is less than 15%, 2%, and 1%, respectively. Compared with pure α-MnO and β-MnO, transition metal-doped α-MnO and β-MnO exhibit better catalytic performance in toluene and formaldehyde removal attributed to their lower crystallinity, more defects, larger specific surface area, more oxygen vacancies, and better low-temperature redox ability. Besides, the introduction of the appropriate proportion of cobalt or nickel into MnO can significantly improve its catalytic activity. Furthermore, the TD/GC-MS result indicates that toluene may be oxidized in the sequence of toluene - benzyl alcohol - benzaldehyde-benzoic acid - acetic acid, 2-cyclohexen-1-one, 4-hydroxy-, cyclopent-4-ene-1,3-dione - carbon dioxide. This method provides a route for the resource utilization of spent LIBs and the synthesis of MnO.
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http://dx.doi.org/10.1016/j.jhazmat.2020.124743DOI Listing
March 2021

Recovery of cathode materials from spent lithium-ion batteries and their application in preparing multi-metal oxides for the removal of oxygenated VOCs: Effect of synthetic methods.

Environ Res 2021 02 2;193:110563. Epub 2020 Dec 2.

School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dong Chuan Road, Shanghai, 200240, PR China; Shanghai Institute of Pollution Control and Ecology Security, Shanghai, 200092, PR China. Electronic address:

Due to the sustainable use of wastes, cathode materials of spent lithium-ion batteries are recovered and used as transition metal precursors to prepare metal oxides catalysts for the oxidation of VOCs. In this work, a series of manganese-based and cobalt-based metal oxides are synthesized via different preparation methods. Catalytic activities of the catalysts prepared are investigated through complete oxidation of oxygenated VOCs and the physicochemical properties of optimum samples are characterized. Evaluation results indicate that MnOx (SY) (HT) sample prepared via hydrothermal method and CoOx (GS) (CP) synthesized via co-precipitation method had better performance, because they have higher specific surface area, higher concentration of active oxygen species and high-valence metal ion, as well as better low-temperature reducibility compared to the other multi-metal oxides used in the study. In addition, TD/GC-MS results imply that further oxidation of by-products requires high reaction temperature during VOCs oxidation.
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http://dx.doi.org/10.1016/j.envres.2020.110563DOI Listing
February 2021

MicroRNA-211-5p attenuates spinal cord injury via targeting of activating transcription factor 6.

Tissue Cell 2021 Feb 9;68:101459. Epub 2020 Nov 9.

Department of Orthopaedics, The General Hospital of Northern Theater Command, Shenyang, Liaoning, 110016, China. Electronic address:

The recovery of spinal cord injury (SCI) involves multiple factors, of which miRNAs take an important part. In this study, we evaluated the function of microRNA-211-5p (miR-211-5p) on SCI in a rat model. SCI model was established using modified Allen's weight-drop method and Basso-Bcattie-Bresnahan score was applied to assess the locomotor function. MiR-211-5p agomir was utilized to increase miR-211-5p expression and endoplasmic reticulum (ER) stress inhibitor, 4-PBA (4-phenylbutyric acid), was utilized to suppress ER stress. Neuron apoptosis and the expressions of miR-211-5p, activating transcription factor 6 (ATF6), apoptosis-related proteins, pro-inflammatory cytokines and endoplasmic reticulum stress-related proteins were detected. Dual luciferase reporter gene assay was performed to verify the binding between miR-211-5p and ATF6. The results showed that miR-211-5p directly targeted ATF6. MiR-211-5p was down-regulated and ATF6 was up-regulated in SCI rats. Both interferences with miR-211-5p agomir and 4-PBA effectively attenuated neuron apoptosis and reversed the expressions of apoptosis, inflammation and endoplasmic reticulum stress-related molecules post SCI in rats. These findings demonstrated that miR-211-5p could effectively alleviate SCI-induced neuron apoptosis and inflammation via directly targeting ATF-6 and regulating ER stress.
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http://dx.doi.org/10.1016/j.tice.2020.101459DOI Listing
February 2021

Ultrasound improves the decontamination effect of thyme essential oil nanoemulsions against Escherichia coli O157: H7 on cherry tomatoes.

Int J Food Microbiol 2021 Jan 30;337:108936. Epub 2020 Oct 30.

College of Biosystems Engineering and Food Science, National-Local Joint Engineering Laboratory of Intelligent Food Technology and Equipment, Zhejiang Key Laboratory for Agro-Food Processing, Integrated Research Base of Southern Fruit and Vegetable Preservation Technology, Zhejiang International Scientific and Technological Cooperation Base of Health Food Manufacturing and Quality Control, Zhejiang University, Hangzhou 310058, China; Fuli Institute of Food Science, Zhejiang University, Hangzhou 310058, China; Ningbo Research Institute, Zhejiang University, Ningbo 315100, China. Electronic address:

Development of novel and effective decontamination technologies to ensure the microbiological safety of fresh produce has gained considerable attention, mainly driven by numerous outbreaks. This work presented the first approach regarding to the application of the previously reported hurdle technologies on the sanitization of artificially contaminated cherry tomatoes. Thyme (Thymus daenensis) essential oil nanoemulsion (TEON, 8.28 nm in diameter with a narrow size distribution) was formulated via ultrasonic nanoemulsification, showing remarkably improved antimicrobial activity against Escherichia coli (E. coli) O157:H7, compared to the coarse emulsion. The antimicrobial effect of ultrasound (US), thyme essential oil nanoemulsion (TEON) and the combination of both treatments was assessed against E. coli O157:H7. The remarkable synergistic effects of the combined treatments were achieved, which decontaminated the E. coli populations by 4.49-6.72 log CFU/g on the surface of cherry tomatoes, and led to a reduction of 4.48-6.94 log CFU/sample of the total inactivation. TEON combined with US were effective in reducing the presence of bacteria in wastewater, which averted the potential detrimental effect of cross-contamination resulted from washing wastewater in fresh produce industry. Moreover, the treatments did not noticeably alter the surface color and firmness of cherry tomatoes. Therefore, ultrasound combined with TEON is a promising and feasible alternative for the reduction of microbiological contaminants, as well as retaining the quality characteristics of cherry tomatoes.
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http://dx.doi.org/10.1016/j.ijfoodmicro.2020.108936DOI Listing
January 2021

Nitrogen, Sulfur Co-Doped Hierarchically Porous Carbon as a Metal-Free Electrocatalyst for Oxygen Reduction and Carbon Dioxide Reduction Reaction.

ACS Appl Mater Interfaces 2020 Oct 22;12(40):44578-44587. Epub 2020 Sep 22.

College of Chemical Engineering, College of Chemistry, Beijing University of Chemical Technology, Beijing 100029, China.

High-cost and low-efficiency electrocatalysts have hindered oxygen reduction reaction (ORR) in fuel cells and CO reduction reaction (CORR) for producing fuels and value-added chemicals. Here, a low-cost metal-free electrocatalyst of a N, S co-doped hierarchically porous carbon (NSHPC) for efficient ORR and CORR is reported. The NSHPC is prepared by pyrolysis of glucosamine hydrochloride and thiocyanuric acid precursors using SiO as hard templates. The N, S co-doping effectively enhances catalytic activity and selectivity, and the hierarchically porous structure largely exposes abundant active sites to reaction species and facilitates electrolyte transport, thereby leading to significantly increased catalytic activities for the NSHPC. The resultant NSHPC exhibits excellent electrocatalytic activities toward ORR in both acidic and alkaline electrolytes and also shows application in proton exchange membrane fuel cells (PEMFCs). More importantly, the NSHPC enables CO reduction to CO with 87.8% maximum Faraday efficiency (FE) in aqueous electrolytes. This work offers a novel insight into the development of multifunctional electrocatalysts for producing electricity, fuels, and value-added chemicals.
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http://dx.doi.org/10.1021/acsami.0c06506DOI Listing
October 2020

Synthesis, Characterization, and Charge-Transport Properties of Halogenated Dibenzo[,]perylenes.

J Org Chem 2020 Oct 16;85(19):12243-12251. Epub 2020 Sep 16.

Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing 100029, P. R. China.

In designing organic semiconductors for organic devices, halogenation is a very popular strategy for tuning the electronic properties and packing arrangement in the solid state. Herein, we report the synthesis and characterization of halogenated dibenzo[,]perylene (DBP) with triethylsilyl (TES)-ethynyl substituents at the 8- and 16-positions (TES-DBP). The resulting compounds are characterized by optical, electrochemical, crystallographic, and computational studies to clarify the effect of halogenation on the optoelectronic properties and charge-carrier transport. It is found that the halogen atoms, the degree of halogenation, and their positional locations can alter the electronic properties and crystal packing of the compounds. In contrast to fluorinated TES-DBP, the chlorinated counterpart has red-shifted maximum absorption and lower electron affinity owing to the electron delocalization between DBP core and the unoccupied 3d orbitals of Cl atom. Organic field-effect transistor measurements demonstrate that TES-2ClDBP shows a hole mobility of 0.25 cm V s, which is higher than TES-2FDBP and TES-DBP. On the other hand, TES-4ClDBP exhibits ambipolar transport characteristics with electron and hole mobilities up to 0.02 and 0.07 cm V s, respectively.
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http://dx.doi.org/10.1021/acs.joc.0c01445DOI Listing
October 2020

A study of the desulfurization selectivity of a reductive and extractive desulfurization process with sodium borohydride in polyethylene glycol.

Sci Rep 2020 Jun 26;10(1):10450. Epub 2020 Jun 26.

School of Environmental Science and Engineering, Shanghai Jiao Tong University, Dongchuan Road 800, Shanghai, 200240, China.

The selectivity of a facile reductive and extractive desulfurization process was studied. In this desulfurization method, polyethylene glycol was used as the extractant, and sodium borohydride was used as the reductant. Several different simulated fuels were prepared by dissolving thiophenic sulfides, methylbenzene and hexylene in octane. The results showed that methylbenzene and olefins had different effects on different sulfur compounds during this desulfurization process. The extraction and reduction mechanisms were also explained. Four factors could affect the desulfurization performance: (1) intermolecular hydrogen bonding: (a) active O bonding with aromatic H or (b) S bonding with H atoms in hydroxide radicals, (2) "like-dissolves-like" interactions between polyethylene glycol and thiophenic sulfides, (3) the methyl steric hindrance effect and the electron density of sulfur atoms, and (4) the combination of S atoms with produced nickel boride to form active desulfurization centres. The desulfurization reaction path was also deduced according to the GC/MS results.
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http://dx.doi.org/10.1038/s41598-020-67235-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7320169PMC
June 2020

Autonomous Search of Radioactive Sources through Mobile Robots.

Sensors (Basel) 2020 Jun 19;20(12). Epub 2020 Jun 19.

Robot Technology Used for Special Environment Key Laboratory of Sichuan Province, Southwest University of Science and Technology, Mianyang 621010, China.

The research of robotic autonomous radioactivity detection or radioactive source search plays an important role in the monitoring and disposal of nuclear safety and biological safety. In this paper, a method for autonomously searching for radioactive sources through mobile robots was proposed. In the method, by using a partially observable Markov decision process (POMDP), the search of autonomous unknown radioactive sources was realized according to a series of radiation information measured by mobile robot. First, the factors affecting the accuracy of radiation measurement during the robot's movement were analyzed. Based on these factors, the behavior set of POMDP was designed. Secondly, the parameters of the radioactive source were estimated in the Bayesian framework. In addition, through the reward strategy, autonomous navigation of the robot to the position of the radiation source was achieved. The search algorithm was simulated and tested, and the TurtleBot robot platform was used to conduct a real search experiment on the radio source Cs-137 with an activity of 37 MBq indoors. The experimental results showed the effectiveness of the method. Additionally, from the experiments, it could been seen that the robot was affected by the linear velocity, angular velocity, positioning accuracy and the number of measurements in the process of autonomous search for the radioactive source. The proposed mobile robot autonomous search method can be applied to the search for lost radioactive sources, as well as for the leakage of substances (nuclear or chemical) in nuclear power plants and chemical plants.
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http://dx.doi.org/10.3390/s20123461DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7349192PMC
June 2020

Promotional removal of oxygenated VOC over manganese-based multi oxides from spent lithium-ions manganate batteries: Modification with Fe, Bi and Ce dopants.

Sci Total Environ 2020 Oct 11;740:139951. Epub 2020 Jun 11.

School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dong Chuan Road, Shanghai 200240, PR China; Shanghai Engineering Research Center of Solid Waste Treatment and Resource Recovery, Shanghai 200240, PR China. Electronic address:

In this work, cathode materials of spent lithium-ions manganate batteries are recovered as the precursor of manganese-based oxides catalysts and furthermore, different amount of Fe, Bi, Ce are introduced to modify their properties. A series of MnOx(MS)-X Fe, MnOx(MS)-X Bi and MnOx(MS)-X Ce samples with crystal phase of MnO are synthesized using combustion method and then the catalytic behavior and physicochemical properties of prepared catalysts are investigated. Compared to binary MnOx-5% Fe, MnOx-15% Bi and MnOx-10% Ce samples, multi MnOx(MS)-5% Fe, MnOx(MS)-15 Bi and MnOx(MS)-10% Ce catalysts display enhanced catalytic performance significantly in the removal of oxygenated VOC, which could be attributed to larger specific surface area, higher concentration of surface active oxygen species and Mn ions and better reducibility at low temperature. In-situ DRIFTS results imply that main oxygen-containing functional groups such as carbonyl (-C=O), carboxyl (-COO), hydroxyl (-OH) can be observed during VOC oxidation and by comparison, it can be found that gas-phase O plays a crucial role in facilitating the further oxidation of by-products into CO. In addition, TD/GC-MS results point out that the main by-products are formaldehyde; 2-propanol, 1-methoxy-; ethanol, 2-methoxy-, acetate; 2-ethoxyethyl acetate; acetic acid during VOC oxidation.
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http://dx.doi.org/10.1016/j.scitotenv.2020.139951DOI Listing
October 2020

Enhanced catalytic activity of oxygenated VOC deep oxidation on highly active in-situ generated GdMnO/GdMnO catalysts.

J Colloid Interface Sci 2020 Oct 2;578:229-241. Epub 2020 Jun 2.

School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dong Chuan Road, Shanghai 200240, PR China; Shanghai Engineering Research Center of Solid Waste Treatment and Resource Recovery, Shanghai 200240, PR China. Electronic address:

In this work, GdMnO material is successfully prepared using sol-gel method and GdMnO/GdMnO materials are in-situ generated by acid treatment. These materials are investigated and applied as catalysts for oxygenated VOC complete oxidation. The evaluation results show that GdMnO/GdMnO-1.00 exhibits a remarkable increase in catalytic activity (T = 198 °C and T = 225 °C) of 2-ethoxyethanol oxidation when compared with the initial sample GdMnO (T = 223 °C and T = none). Characterization analyses show that acid treatment can result in the significant improvement of specific surface area from 20.502 m·g to 67.952 m·g, abundant surface Mn content and active oxygen, excellent reducibility at low temperature in GdMnO/GdMnO-1.00 sample. In-situ DRIFTS results point out that the main functional groups such as ν(OCO), ν(COO), ν(CO) are formed in the process of 2-ethoxyethanol oxidation over GdMnO/GdMnO-1.00 sample and some by-products including ethanol, 2-ethoxyethyl acetate, acetic acid, carbonic acid, 2-ethoxyethyl 2-methoxyethyl ester, ethane and 1,1'-oxybis[2-methoxy-] can be produced at a reaction temperature of 200 °C. Additionally, in-situ DRIFTS studies indicate the presence of gas-phase O plays a vital role in facilitating 2-ethoxyethanol deep oxidation to final products.
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http://dx.doi.org/10.1016/j.jcis.2020.05.095DOI Listing
October 2020

Using Epoxidized Solution Polymerized Styrene-Butadiene Rubbers (ESSBRs) as Coupling Agents to Modify Silica without Volatile Organic Compounds.

Polymers (Basel) 2020 May 30;12(6). Epub 2020 May 30.

State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, P.O. Box 57, Beisanhuan East Road, Beijing 100029, China.

Rubber used in tire is usually strengthened by nanofiller, and the most popular nanofiller for tire tread rubber is nano silica, which can not only strengthen rubber but also lower the tire rolling resistance to reduce fuel consumption. However, silica particles are difficult to disperse in the rubber matrix because of the abundant silicon hydroxyl on their surface. Silane coupling agents are always used to modify silica and improve their dispersion, but a large number of volatile organic compounds (VOCs) are emitted during the manufacturing of the nanosilica/rubber composites because of the condensation reaction between silane coupling agents and silicon hydroxyl on the surface of silica. Those VOCs will do great harm to the environment and the workers' health. In this work, epoxidized solution polymerized styrene-butadiene rubbers (ESSBR) with different epoxy degrees were prepared and used as macromolecular coupling agents aimed at fully eliminating VOCs. Fourier transform infrared (FTIR) spectroscopy and nuclear magnetic resonance (NMR) analyses verified that the different ESSBRs were successfully synthesized from solution polymerized styrene-butadiene rubbers (SSBR). With the help of the reaction between epoxy groups and silicon hydroxyl without any VOC emission, nanosilica can be well dispersed in the rubber matrix when SSBR partially replaced by ESSBR which was proved by Payne effect and TEM analysis. Dynamic and static mechanical testing demonstrated that silica/ESSBR/SSBR/BR nanocomposites have better performance and no VOC emission compared with Bis-(γ-triethoxysilylpropyl)-disulfide (TESPD) modified silica/rubber nanocomposites. ESSBR is very hopeful to replace traditional coupling agent TESPD to get high properties silica/rubber nanocomposites with no VOCs emission.
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http://dx.doi.org/10.3390/polym12061257DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7361802PMC
May 2020
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