Synergistic defect and doping engineering building strong bonded S-scheme heterojunction for photocatalysis.

Photocatalytic degradation of pollutants is considered a promising approach for wastewater treatment, but is hampered by low efficiency and limited understanding of degradation pathways. A novel oxygen-doped porous g-C3N4/oxygen vacancies-rich BiOCl (OCN/OVBOC) heterostructure was prepared for photocatalytic degradation of bisphenol A (BPA). The synergistic defect and doping engineering favor the formation of strong bonded interface for S-scheme mechanism. Among them, 0.3 OCN/OVBOC showed the most excellent degradation rate, which was 8 times and 4 times higher than that of pure g-C3N4 and BiOCl, respectively. This excellent performance is mainly attributed to the significantly enhanced charge separation via strong bonded interface and redox capability of the S-scheme heterojunction structure, by tuning the coordination excitation and electron localization of the catalyst via O doping and vacancies. This work provides important insights into the role of synergistic defect and doping engineering in facilitating the formation of strong bonded S-scheme heterojunction and ultimately sheds new light on the design of efficient photocatalysts.

[Effects of electroacupuncture on NLRP3/Caspase-1/GSDMD axis and neurological function in rats with cerebral ischemic reperfusion].

OBJECTIVE: To investigate the neuroprotective effect of electroacupuncture (EA) at "Quchi" (LI 11) and "Zusanli" (ST 36) in the rats with cerebral ischemic reperfusion and the potential mechanism of microglia pyroptosis. METHODS: Sixty SD rats were randomly divided into a sham-operation group, a model group and an EA group, with 20 rats in each group. The Zea Longa method was employed to establish the rat model of the middle cerebral artery occlusion and reperfusion (MACO/R) in the left brain. In the EA group, since the 2nd day of modeling, EA was given at "Quchi" (LI 11) and "Zusanli" (ST 36) of right side with disperse-dense wave, 4 Hz/20 Hz in frequency and 0.2 mA in current intensity, 30 min each time, once a day for lasting 7 consecutive days. The reduction rate of cerebral blood flow was measured with laser Doppler flowmetry during operation. The neurological function of rats was observed using Zea Longa neurobehavioral score. The cerebral infarction volume was detected by TTC staining method. The microglia positive expression in the ischemic side of the cortex was detected with the immunofluorescence method. Under transmission electron microscope, the ultrastructure of cell in the ischemic cortex was observed. The mRNA expression levels of nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3), apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC), cysteinyl aspartate specific proteinase-1 (Caspase-1) and gasdermin D (GSDMD) in the ischemic cortex were detected using real-time PCR. RESULTS: Compared with the sham-operation group, in the model group, the reduction rate of cerebral blood flow was increased during operation (P<0.001); Zea Longa neurobehavional score and the percentage of cerebral infarction volume were increased (P<0.001), the numbers of M1-type microglia marked by CD68+ and M2-type microglia marked by TMEM119+ were elevated in the ischemic cortex (P<0.001), the mRNA expression of NLRP3, ASC, Caspase-1 and GSDMD was increased (P<0.001, P<0.01); the cytomembrane structure was destroyed, with more cell membrane pores formed in the ischemic cortex. Compared with the model group, after intervention, Zea Longa neurobehavioral score and the percentage of cerebral infarction volume were reduced (P<0.05), the number of M1-type microglia marked by CD68+ was reduced (P<0.05) and the number of M2-type microglia marked by TMEM119+ was increased (P<0.05); and the mRNA expression of NLRP3, ASC, Caspase-1 and GSDMD was decreased (P<0.01, P<0.05) in the EA group. Even though the cytomembrane structure was incomplete, there were less membrane pores presented in the ischemic cortex in the EA group after intervention. CONCLUSION: The intervention with EA attenuates the neurological dysfunction and reduces the volume of cerebral infarction in the rats with cerebral ischemic reperfusion. The underlying mechanism is related to the inhibition of microglia pyroptosis through modulating NLRP3/Caspase-1/GSDMD axis.

Chromosome-level genome assembly and resequencing of camphor tree (Cinnamomum camphora) provides insight into phylogeny and diversification of terpenoid and triglyceride biosynthesis of Cinnamomum.

Cinnamomum species attract attentions owing to their scents, medicinal properties, and ambiguous relationship in the phylogenetic tree. Here, we report a high-quality genome assembly of Cinnamomum camphora, based on which two whole-genome duplication (WGD) events were detected in the C. camphora genome: one was shared with Magnoliales, and the other was unique to Lauraceae. Phylogenetic analyses illustrated that Lauraceae species formed a compact sister clade to the eudicots. We then performed whole-genome resequencing on 24 Cinnamomum species native to China, and the results showed that the topology of Cinnamomum species was not entirely consistent with morphological classification. The rise and molecular basis of chemodiversity in Cinnamomum were also fascinating issues. In this study, six chemotypes were classified and six main terpenoids were identified as major contributors of chemodiversity in C. camphora by the principal component analysis. Through in vitro assays and subcellular localization analyses, we identified two key terpene synthase (TPS) genes (CcTPS16 and CcTPS54), the products of which were characterized to catalyze the biosynthesis of two uppermost volatiles (i.e. 1,8-cineole and (iso)nerolidol), respectively, and meditate the generation of two chemotypes by transcriptional regulation and compartmentalization. Additionally, the pathway of medium-chain triglyceride (MCT) biosynthesis in Lauraceae was investigated for the first time. Synteny analysis suggested that the divergent synthesis of MCT and long-chain triglyceride (LCT) in Lauraceae kernels was probably controlled by specific medium-chain fatty acyl-ACP thioesterase (FatB), type-B lysophosphatidic acid acyltransferase (type-B LPAAT), and diacylglycerol acyltransferase 2b (DGAT 2b) isoforms during co-evolution with retentions or deletions in the genome.

Preparation of TiO2/porous glass-H with the coupling of photocatalysis oxidation-adsorption system in the initial position and its desulfurization performance on model fuel.

TiO2/porous glass-H as composite catalysts were synthesized hydrothermally in the presence of H2O2 using porous glass microspheres as carriers. The photocatalytic-adsorptive desulfurization of model fuel by composite catalysts was investigated under UV irradiation. The structure and morphology of the composite catalysts were characterized via scanning electron microscopy (SEM), N2 adsorption, X-ray diffraction (XRD) and ultraviolet-visible spectroscopy (UV-vis). The results showed that TiO2/porous glass-H exhibited a significantly enhanced photocatalytic-adsorption desulfurization performance due to its enhanced surface area, highly enhanced light absorption, and reduced recombination of photogenerated electron pairs compared with TiO2/porous glass synthesized in the absence of H2O2. The optimized TiO2 loading was 20% and the reaction temperature was 303.15 K, which could achieve almost 100% sulfur removal when 0.1 g catalyst was applied to a sulfide concentration of 300 mg L-1. Based on the kinetic fitting of the obtained data, it was found that the rate-controlling step of sulfide adsorption on the catalyst was a molecular diffusion process and the adsorption intensity and adsorption capacity of the composite catalyst were significantly improved compared with the porous glass-H in the adsorption thermodynamic curve, and ΔS, ΔH and ΔG of the adsorption process were calculated. In addition, TiO2/porous glass-H could be regenerated via simple heat treatment, exhibiting similar efficiency as the original TiO2/porous glass-H after three regeneration cycles.

Secondary ion mass spectrometry: The application in the analysis of atmospheric particulate matter.

Currently, considerable attention has been paid to atmospheric particulate matter (PM) investigation due to its importance in human health and global climate change. Surface characterization, single particle analysis and depth profiling of PM is important for a better understanding of its formation processes and predicting its impact on the environment and human being. Secondary ion mass spectrometry (SIMS) is a surface technique with high surface sensitivity, high spatial resolution chemical imaging and unique depth profiling capabilities. Recent research shows that SIMS has great potential in analyzing both surface and bulk chemical information of PM. In this review, we give a brief introduction of SIMS working principle and survey recent applications of SIMS in PM characterization. Particularly, analyses from different types of PM sources by various SIMS techniques were discussed concerning their advantages and limitations. The future development and needs of SIMS in atmospheric aerosol measurement are proposed with a perspective in broader environmental sciences.

A precise pointing nanopipette for single-cell imaging via electroosmotic injection.

The precise transportation of fluorescent probes to the designated location in living cells is still a challenge. Here, we present a new addition to nanopipettes as a powerful tool to deliver fluorescent molecules to a given place in a single cell by electroosmotic flow, indicating favorable potential for further application in single-cell imaging.

Effect of hydrolysis time on the physicochemical and functional properties of corn glutelin by Protamex hydrolysis.

The physicochemical and functional properties, such as surface hydrophobicity, disulphide bond content, thermal properties, molecular weight distribution, antioxidant properties, of corn glutelin hydrolysates catalysed by Protamex at different hydrolysis times were evaluated. The hydrolysis influenced the properties of corn glutelin significantly, and not only decreased its molecular weight and disulphide bond content, but also eventually transformed its insoluble native aggregates to soluble aggregates during the hydrolysis process. Corn glutelin hydrolysates were found to have a higher solubility, which was associated with their relatively higher foaming and emulsifying properties compared to the original glutelin. Corn glutelin and its hydrolysates maintained a high thermal stability. In addition, the hydrolysates exhibited excellent antioxidant properties measured through in vitro assays, namely DPPH and OH radical scavenging activity, Fe(2+)-chelating capacity and reducing power; the values were 58.86%, 82.64%, 29.92% and 0.236% at 2.0mg/mL, respectively.

[Kinetics and mechanism of aniline oxidation with chlorine dioxide in water].

Reaction kinetics of aniline oxidation with chlorine dioxide in water were investigated systematically by detecting concentrations of aniline with HPLC at regular intervals. Results showed that the reaction was first-order with respect to both chlorine dioxide and aniline, and the entire reaction was of second-order. Under condition of pH 6.86 and water temperature (Tw) 287 K, the second-order reaction rate constant k was 0.11 L x (mol x s)(-1). Reaction activation energy was 73.11 kJ x mol(-1), revealing that the reaction could take place under usual water treatment conditions. The reaction rate constants in acidic and alkali media were greater than that in neutral medium. Effect of chlorite ion on the reaction rate was insignificant. P-aminophenol and azobenzene were detected by GC MS as intermediates. Oxidation pathways were proposed and discussed elementarily.

Kinetics of aniline oxidation with chlorine dioxide.

For the first time, kinetics of aniline oxidation with chlorine dioxide (ClO2) were investigated systematically by detecting concentration of aniline with HPLC at regular intervals. Results showed that the reaction was first-order both in ClO2 and in aniline, and the oxidation reaction could be described as second-order reaction. Stoichiometric factor eta was experimentally determined to be 2.44. The second-order-reaction rate constant k was 0.11 L/(mol x s) under condition of pH 6.86 and water temperature (Tw) 287K. Reaction activation energy was 72.31 kJ/mol, indicating that the reaction could take place under usual water treatment conditions. The reaction rate constants in acidic and alkali media were greater than that in neutral medium. Chlorite ion could slightly increase reaction rate in acidic medium. p-aminophenol and azobenzene were detected by GC-MS as intermediates.