High-performance activation of ozone by sonocavitation for BTEX degradation in water.

This work presents a novel advanced oxidation process (AOP) for degradation of emerging organic pollutants - benzene, toluene, ethylbenzene and xylenes (BTEXs) in water. A comparative study was performed for sonocavitation assisted ozonation under 40-120 kHz and 80-200 kHz dual frequency ultrasounds (DFUS). Based on the obtained results, the combination of 40-120 kHz i.e., low-frequency US (LFDUS) with O3 exhibited excellent oxidation capacity degrading 99.37-99.69% of BTEXs in 40 min, while 86.09-91.76% of BTEX degradation was achieved after 60 min in 80-200 kHz i.e., high-frequency US (HFDUS) combined with O3. The synergistic indexes determined using degradation rate constants were found as 7.86 and 2.9 for LFDUS/O3 and HFDUS/O3 processes, respectively. The higher extend of BTEX degradation in both processes was observed at pH 6.5 and 10. Among the reactive oxygen species (ROSs), hydroxyl radicals (HO•) were found predominant according to scavenging tests, singlet oxygen also importantly contributed in degradation, while O2•- radicals had a minor contribution. Sulfate (SO42-) ions demonstrated higher inhibitory effect compared to chloride (Cl-) and carbonate (CO32-) ions in both processes. Degradation pathways of BTEX was proposed based on the intermediates identified using GC-MS technique.

A Bioinspired Atomically Thin Nanodot Supported Single-Atom Nanozyme for Antibacterial Textile Coating.

Surface antibacterial coatings with outstanding antibacterial efficiency have attracted increasing attention in medical protective clothing and cotton surgical clothing. Although nanozymes, as a new generation of antibiotics, are used to combat bacteria, their catalytic performance remains far from satisfactory as alternatives to natural enzymes. Single-atom nanodots provide a solution to the low catalytic activity bottleneck of nanozymes. Here, atomically thin C3 N4 nanodots supported single Cu atom nanozymes (Cu-CNNDs) are developed by a self-tailoring approach, which exhibits catalytic efficiency of 8.09 × 105 M-1 s-1 , similar to that of natural enzyme. Experimental and theoretical calculations show that excellent peroxidase-like activity stems from the size effect of carrier optimizing the coordination structure, leading to full exposure of Cu-N3 active site, which improves the ability of H2 O2 to generate hydroxyl radicals (•OH). Notably, Cu-CNNDs exhibit over 99% superior antibacterial efficacy and are successfully grafted onto cotton fabrics. Thus, Cu-CNNDs blaze an avenue for exquisite biomimetic nanozyme design and have great potential applications in antibacterial textiles.

A methane-cGMP module positively influences adventitious rooting.

KEY MESSAGE: Endogenous cGMP operates downstream of CH4 control of adventitious rooting, following by the regulation in the expression of cell cycle regulatory and auxin signaling-related genes. Methane (CH4) is a natural product from plants and microorganisms. Although exogenously applied CH4 and cyclic guanosine monophosphate (cGMP) are separately confirmed to be involved in the control of adventitious root (AR) formation, the possible interaction still remains elusive. Here, we observed that exogenous CH4 not only rapidly promoted cGMP synthesis through increasing the activity of guanosine cyclase (GC), but also induced cucumber AR development. These responses were obviously impaired by the removal of endogenous cGMP with two GC inhibitors. Anatomical evidence showed that the emerged stage (V) among AR primordia development might be the main target of CH4-cGMP module. Genetic evidence revealed that the transgenic Arabidopsis that overexpressed the methyl-coenzyme M reductase gene (MtMCR) from Methanobacterium thermoautotrophicum not only increased-cGMP production, but also resulted in a pronounced AR development compared to wild-type (WT), especially with the addition of CH4 or the cell-permeable cGMP derivative 8-Br-cGMP. qPCR analysis confirmed that some marker genes associated with cell cycle regulatory and auxin signaling were closely related to the brand-new CH4-cGMP module in AR development. Overall, our results clearly revealed an important function of cGMP in CH4 governing AR formation by modulating auxin-dependent pathway and cell cycle regulation.

Cobalt and nitrogen co-doped monolithic carbon foam for ultrafast degradation of emerging organic pollutants via peroxymonosulfate activation.

Cobalt-based catalysts are expected as one of the most promising peroxymonosulfate (PMS) activators for the removal of organic pollutants from industrial wastewater. However, the easy agglomeration, difficult separation, and secondary pollution of cobalt ions limit their practical application. In this study, a novel, highly efficient, reusable cobalt and nitrogen co-doped monolithic carbon foam (Co-N-CMF) was utilized to activate PMS for ultrafast pollutant degradation. Co-N-CMF (0.2 g/L) showed ultrafast catalytic kinetics and higher total organic carbon (TOC) removal efficiency. Bisphenol A, ciprofloxacin, 2,4-dichlorophenoxyacetic acid, and 2,4-dichlorophenol could be completely degraded after 2, 4, 5, and 5 min, and the TOC removal efficiencies were 77.4 %, 68.9 %, 72.8 %, and 79.8 %, respectively, corresponding to the above pollution. The sulfate radical (SO4•-) was the main reactive oxygen species in Co-N-CMF/PMS based on electron paramagnetic resonance. The ecological structure-activity relationship program analysis via the quantitative structure activity relationship analysis and phytotoxicity assessment revealed that the Co-N-CMF/PMS system demonstrates good ecological safety and ecological compatibility. The Co-N-CMF catalyst has good catalytic activity and facile recycling, which provides a fine method with excellent PMS activation capacity for 2,4-dichlorophenol elimination from simulated industrial wastewater. This study provides new insights into the development of monolithic catalysts for ultrafast wastewater treatment via PMS activation.

Molecular Hydrogen Increases Quantitative and Qualitative Traits of Rice Grain in Field Trials.

How to use environmentally friendly technology to enhance rice field and grain quality is a challenge for the scientific community. Here, we showed that the application of molecular hydrogen in the form of hydrogen nanobubble water could increase the length, width, and thickness of brown/rough rice and white rice, as well as 1000-grain weight, compared to the irrigation with ditch water. The above results were well matched with the transcriptional profiles of representative genes related to high yield, including up-regulation of heterotrimeric G protein ß-subunit gene (RGB1) for cellular proliferation, Grain size 5 (GS5) for grain width, Small grain 1 (SMG1) for grain length and width, Grain weight 8 (GW8) for grain width and weight, and down-regulation of negatively correlated gene Grain size 3 (GS3) for grain length. Meanwhile, although total starch content in white rice is not altered by HNW, the content of amylose was decreased by 31.6%, which was parallel to the changes in the transcripts of the amylose metabolism genes. In particular, cadmium accumulation in white rice was significantly reduced, reaching 52% of the control group. This phenomenon was correlated well with the differential expression of transporter genes responsible for Cd entering plants, including down-regulated Natural resistance-associated macrophage protein (Nramp5), Heavy metal transporting ATPase (HMA2 and HMA3), and Iron-regulated transporters (IRT1), and for decreasing Cd accumulation in grain, including down-regulated Low cadmium (LCD). This study clearly showed that the application of molecular hydrogen might be used as an effective approach to increase field and grain quality of rice.

Carbon aerogel from forestry biomass as a peroxymonosulfate activator for organic contaminants degradation.

The carbon catalyst has been widely used as a peroxymonosulfate (PMS) activator to degrade organic contaminants. The biomass carbon aerogel (CA) derived from poplar powder was synthesized in this study. CA with three-dimensional structure exhibited an excellent degradation performance of PMS activation for different types of organic contaminants including bisphenol A (BPA), rhodamine 6 G, phenol, and p-chlorophenol with the removal efficiencies up to 91%, 100%, 100%, and 60% within 60 min, respectively. It was found that singlet oxygen (1O2) dominated the non-radical pathway worked for BPA removal in CA/PMS system. The possible mechanism for PMS activation was discussed. A portion of 1O2 was produced through the transformation of superoxide radical (O2•-) in CA/PMS system. Electronic impedance spectroscopy (EIS) proved that the hierarchical structure of CA contributed to the electron transfer process for PMS activation. The ketonic/carbonyl groups (CË­O) on the surface of CA could serve as a possible active site to facilitate the generation of 1O2. In addition, CA showed superior degradation performance in actual water bodies and reusability with high-temperature regeneration treatment. This study developed an efficient and environmentally benign catalyst for water remediation of organic pollutants.

Methane control of cadmium tolerance in alfalfa roots requires hydrogen sulfide.

Hydrogen sulfide (H2S) is well known as a gaseous signal in response to heavy metal stress, while methane (CH4), the most prevalent greenhouse gas, confers cadmium (Cd) tolerance. In this report, the causal link between CH4 and H2S controlling Cd tolerance in alfalfa (Medicago sativa) plants was assessed. Our results observed that the administration of CH4 not only intensifies H2S metabolism, but also attenuates Cd-triggered growth inhibition in alfalfa seedlings, which were parallel to the alleviated roles in the redox imbalance and cell death in root tissues. Above results were not observed in roots after the removal of endogenous H2S, either in the presence of either hypotaurine (HT; a H2S scavenger) or DL-propargylglycine (PAG; a H2S biosynthesis inhibitor). Using in situ noninvasive microtest technology (NMT) and inductively coupled plasma mass spectroscopy (ICP-MS), subsequent results confirmed the participation of H2S in CH4-inhibited Cd influx and accumulation in roots, which could be explained by reestablishing glutathione (GSH) pool (reduced/oxidized GSH and homoglutathione) homeostasis and promoting antioxidant defence. Overall, our results clearly revealed that H2S operates downstream of CH4 enhancing tolerance against Cd stress, which are significant for both fundamental and applied plant biology.

Hydrogen Commonly Applicable from Medicine to Agriculture: From Molecular Mechanisms to the Field.

The emerging field of hydrogen biology has to date mainly been applied in medicine. However, hydrogen biology can also enable positive outcomes in agriculture. Agriculture faces significant challenges resulting from a growing population, climate change, natural disasters, environmental pollution, and food safety issues. In fact, hydrogen agriculture is a practical application of hydrogen biology, which may assist in addressing many of these challenges. It has been demonstrated that hydrogen gas (H2) may enhance plant tolerance towards abiotic and biotic stresses, regulate plant growth and development, increase nutritional values, prolong the shelf life, and decrease the nitrite accumulation during the storage of vegetables, as well as increase the resilience of livestock to pathogens. Our field trials show that H2 may have a promising potential to increase yield and improve the quality of agricultural products. This review aims to elucidate mechanisms for a novel agricultural application of H2 in China. Future development of hydrogen agriculture is proposed as well. Obviously, hydrogen agriculture belongs to a low carbon economy, and has great potential to provide "safe, tasty, healthy, and high-yield" agricultural products so that it may improve the sustainability of agriculture.

Facile synthesis of superparamagnetic ß-CD-MnFe2O4 as a peroxymonosulfate activator for efficient removal of 2,4- dichlorophenol: structure, performance, and mechanism.

In this study, superparamagnetic ß-CD-MnFe2O4 with a large surface area was synthesized via a facile co-precipitation method, with ß-cyclodextrin (ß-CD) acting as a coating agent. The as-prepared ß-CD-MnFe2O4 exhibited better catalytic performance than bare MnFe2O4 in terms of activating peroxymonosulfate (PMS) to degrade 2,4-dichlorophenol (2,4-DCP) over a broad pH range of 5-11. Electron spin resonance spectroscopy (ESR) and free radical quenching experiments indicate that various active species (SO4-/OH/O2-/1O2) are generated in the ß-CD-MnFe2O4/PMS system and that pollutants trapped in the cyclodextrin cavity are quickly degraded. Various reaction parameters of the ß-CD-MnFe2O4/PMS system and the stability of ß-CD-MnFe2O4 were also investigated. The results indicate that ß-CD-MnFe2O4 is promising for use in water purification owing to its excellent magnetic separation and recovery properties and good resistance to humic acid (HA).

A Novel Mechanism Underlying Multi-walled Carbon Nanotube-Triggered Tomato Lateral Root Formation: the Involvement of Nitric Oxide.

Abundant studies revealed that multi-walled carbon nanotubes (MWCNTs) are toxic to plants. However, whether or how MWCNTs influence lateral root (LR) formation, which is an important component of the adaptability of the root system to various environmental cues, remains controversial. In this report, we found that MWCNTs could enter into tomato seedling roots. The administration with MWCNTs promoted tomato LR formation in an approximately dose-dependent fashion. Endogenous nitric oxide (NO) production was triggered by MWCNTs, confirmed by Greiss reagent method, electron paramagnetic resonance (EPR), and laser scanning confocal microscopy (LSCM), together with the scavenger of NO. A cause-effect relationship exists between MWCNTs and NO in the induction of LR development, since MWCNT-triggered NO synthesis and LR formation were obviously blocked by the removal of endogenous NO with its scavenger. The activity of NO generating enzyme nitrate reductase (NR) was increased in response to MWCNTs. Tungstate inhibition of NR not only impaired NO production, but also abolished LR formation triggered by MWCNTs. The addition of NG-nitro-L-arginine methyl ester (L-NAME), an inhibitor of mammalian nitric oxide synthase (NOS)-like enzyme, failed to influence LR formation. Collectively, we proposed that NO might act as a downstream signaling molecule in MWCNT control of LR development, at least partially via NR.

Mn3O4 nanodots loaded g-C3N4 nanosheets for catalytic membrane degradation of organic contaminants.

Peroxymonosulfate (PMS) activation by heterogeneous catalysts has been widely investigated to remove organic contaminants. Nevertheless, the technology is restricted to the bench-scale batch system. For practical applications, a supported catalyst design based on a reactor configuration with catalyst recovery is the need for future development. In this study, Mn3O4 nanodots-g-C3N4 nanosheets (Mn3O4/CNNS) composites were prepared via a facile hydrothermal method. The micro-structures and compositions of composites were investigated by a series of characterization methods. It was found that the Mn3O4 nanodots (5-10 nm) were distributed uniformly over the CNNS. When the added amount of CNNS was 150 mg during the synthesis process, a composite named as Mn3O4/CNNS-150 was obtained, which exhibited the best performance on PMS activation for 4-chlorophenol (4-CP) removal. The Mn3O4/CNNS-150@PTFE membrane was synthesized by facile vacuum filtration. The catalytic membrane was applied in filtration experiments for the degradation of different contaminants. The stability tests revealed excellent stability of the catalytic membrane. The redox circles of Mn(IV)/Mn(III)/Mn(II) on the Mn3O4 surface were the main source of activated PMS and a possible activation mechanism in the reaction system was provided. This study is of great significance for the development of novel catalytic membranes with PMS activation.

Biomass Schiff base polymer-derived N-doped porous carbon embedded with CoO nanodots for adsorption and catalytic degradation of chlorophenol by peroxymonosulfate.

The development of highly active and multifunctional carbocatalysts modified with heteroatoms or metal species is crucial for practical environmental remediation applications. In this study, nitrogen-doped porous carbon embedded with highly dispersed CoO nanodots (CoO-N-C) was successfully prepared from a biomass-derived Schiff base polymer for the first time. The morphology analysis shows that CoO nanodots were embedded in the N doped carbon layer with size of ∼6.5 nm. CoO-N-C catalyst exhibited excellent 4-CP adsorption efficiency as well as excellent catalytic performance in the activation of peroxymonosulfate (PMS) for 4-CP degradation. Total organic carbon (TOC) removal was close to 99.7% and involved a combination of adsorption and degradation processes. Singlet oxygen (1O2) was found to be the dominant oxidative species for 4-CP degradation. The underlying mechanism of these processes were elucidated, and it was found that the introduction of CoO nanodots in CoO-N-C not only enhanced radical catalytic processes, but also significantly enhanced the non-radical catalytic processes of PMS activation. This derived from the synergistic effect between the embedded CoO nanodots and doped nitrogen for the increase of electron density on carbon surface of catalyst, thereby accelerating the electron transfer process for PMS activation and improving the catalytic performance.

Cu2O@ß-cyclodextrin as a synergistic catalyst for hydroxyl radical generation and molecular recognitive destruction of aromatic pollutants at neutral pH.

Wastewater systems contain a large number of compounds, such as anthropogenic aromatic pollutants and natural organic matter (NOM), and usually have pH higher than 4. Fenton-like reaction is the most widespread method for removal of organic pollutants, but their reactivity with H2O2 may be inhibited by NOM due to the competition of hydroxyl radicals and chelating agents. In this work, Cu2O@ß-cyclodextrin was developed to achieve the collaboration between molecular recognition and Fenton-like catalysis to destruct aromatic pollutants at neutral pH. In Cu2O@ß-CD, covalent CuOC bond was topotaxially converted from CuCl assisted by ß-CD at room temperature. Covalently linked ß-CD could keep humic acid from interfering catalytic performance of Cu2O surfaces and inhibit the leaching of copper. A higher catalytic ability was observed for Cu2O@ß-CD with rate constant 0.0331 min-1 than Cu2O (0.0064 min-1) at neutral pH. A mechanism of synergistic catalysis was proposed on the basis of Cu+, ß-CD and phenoxo-Cu2+ complexes in the Cu2O@ß-CD/BPA/H2O2 system. The strategy of coupling molecular recognition into Fenton-like reaction provides an efficient and promising approach to the destruction of aromatic pollutants at neutral pH.

Efficient activation of persulfate by Fe3O4@ß-cyclodextrin nanocomposite for removal of bisphenol A.

Experimental studies were conducted to investigate the degradation of bisphenol A (BPA) by using persulfate (PS) as the oxidant and Fe3O4@ß-cyclodextrin (ß-CD) nanocomposite as a heterogeneous activator. The catalytic activity was evaluated in consideration of the effect of various parameters, such as pH value, PS concentration and Fe3O4@ß-CD load. The results showed that 100% removal of BPA was gained at pH 3.0 with 5 mM PS, 1.0 g L-1 Fe3O4@ß-CD, and 0.1 mM BPA in 120 min. Further, the catalytic activity of Fe3O4@ß-CD nanocomposite was observed as much higher when compared with Fe3O4 nanoparticles alone. The sulfate and hydroxyl radicals referred to in the Fe3O4@ß-CD/PS system were determined as the reactive species responsible for the degradation of BPA by radical quenching and electron spin resonance (ESR) tests. In addition, the catalyst also possessed with accepted reusability and stability. On the basis of the results of the effect of chloride ions (Cl-), ß-CD was found to play a crucial role in reducing interference from Cl- ions, and lead to achieve higher removal efficiency for BPA in Fe3O4@ß-CD/PS system. A possible mechanistic process of BPA degradation was proposed according to the identified intermediates by gas chromatography-mass spectroscopy (GC-MS).

The Dynamic Mechanical Analysis of Highly Filled Rice Husk Biochar/High-Density Polyethylene Composites.

In this study, rice husk biochar/high-density polyethylene (HDPE) composites were prepared via melt mixing followed by extrusion. Effects of biochar content and testing temperature on the dynamic mechanical analysis (DMA) of the composites were studied. Morphological analysis of the rice husk biochar and composites were evaluated by scanning electron microscopy (SEM). The results showed that biochar had a positive effect on dynamic viscoelasticity, creep resistance and stress relaxation properties of the composites, but the creep resistance and stress relaxation of the composites decreased with the increase of temperature. SEM analysis showed that HDPE components were embedded in the holes of the rice husk biochar, and it is believed that strong interaction was achieved.

[Surgical treatment for primary papillary thyroid cancer: a Meta-analysis].

OBJECTIVE: To assess and compare the two procedures, total thyroidectomy (TT) and partial thyroidectomy (PT), for papillary thyroid cancer in terms of associated injuries, postoperative complication, recurrence rate and survival, so as to provide a reference and basis for surgical procedure option of this disease. METHOD: Strictly specified into the exclusion criteria, the combination of computer retrieval and manual retrieval and retrieval systems such as CNKI, Wang Fan, PubMed, central, CBM database. Total thyroidectomy and partial thyroidectomy for the treatment of patients with thyroid papillary cancer related literature were compared, with the retrieval time until December 31, 2013. RESULT: According to the retrieval strategy 4630 literatures were found, and 20 witch matched the exclusion criteria were left, all were retrospective study. TT and PT group of recurrent laryngeal nerve injury rate are 5.9%, 2.0% respectively [OR = 0.39, 95% CI (0.17 - 0.90), P < 0.05], TT and PT group of parathyroid injury rate are respectively 4.9%, 0.8% respectively [OR = 0.23, 95% CI (0.08 - 0.68), P < 0.01]. The TT group of 10 years survival rate is 95.24% - 100%, and the PT group is 96.8% - 99.2% [OR = 0.03, 95% CI (0 - 0.34), P < 0.01]. Unstaged, unstaged TT group' postoperative recurrence rate is 4.7%, while PT group is 12.6% [OR = 3.21, 95% CI (1.57 - 6.57), P < 0. 01]. Postoperative recurrence of stage I TT group and PT group are 4.9%, 7.8% respectively [OR = 3.82, 95% CI (1. 07-13.66) P < 0.05]; The rate of stage II TT group is 0.5%, while the rate of PT group is 15.9% [OR = 17.23, 95% CI (4.03 - 73.73), P < 0.01]. CONCLUSION: Different methods of primary thyroid papillary carcinoma surgical treatment can all obtaina good survival, but the rate of laryngeal recurrent nerve injury and parathyroid injury caused by partal throidectomy is relatively lower. As a result, partial thyroidectomy can be a good choice for early stage thyroid papillary carcinoma.

[Expression of cancer stem cell marker USP22 in laryngeal squamous cell carcinoma].

OBJECTIVE: To investigate the expression of cancer stem cell marker USP22 in laryngeal squamous cell carcinoma (LSCC) and clinical implications. METHODS: The expression of USP22 was detected by immunohistochemistry in LSCC tissues of 64 cases and squamous epithelium tissues beside carcinoma of 26 cases (control). The correlation of USP22 expression with various clinicopathologic factors was evaluated with the single factor analysis. RESULTS: The expression levels of USP22 in LSCC and control were 57.8% and 19.2% (P < 0.05). Clinicopathological analysis showed that USP22 expression level had a relationship with clinical stage, T stage, and lymph node metastasis (P < 0.05), but not with gender, age, smoking and differentiation (P > 0.05). Survival analysis showed that patients with high USP22 expression had significantly poorer outcome compared with patients with low USP22 expression. The survival was related to clinical stage, T stage, and lymph node metastasis, but not with age, sex, and smoking (P > 0.05). CONCLUSIONS: The expression of USP22 is significantly increased in LSCC, which correlates with the malignant degree, invasion, metastasis and prognosis of LSCC. USP22 may be served as a new candidate molecular marker and therapeutic target of LSCC.