Recent progress in organic-inorganic hybrid materials as absorbents in sample pretreatment for pesticide detection.

Sample pretreatment is essential for trace analysis of pesticides in complex food and environment matrices. Recently, organic-inorganic hybrid materials have gained increasing attention in pesticide extraction and preconcentration. This review highlighted the common organic-inorganic hybrid materials used as absorbents in sample pretreatment for pesticide detection. Furthermore, the preparation and characterization of organic-inorganic hybrid materials were summarized. To obtain a deep understanding of adsorption toward target analytes, the adsorption mechanism and absorption evaluation were discussed. Finally, the applications of organic-inorganic hybrid materials in sample pretreatment techniques and perspectives in the future are also discussed.

Recognition elements based on the molecular biological techniques for detecting pesticides in food: A review.

Excessive use of pesticides can cause contamination of the environment and agricultural products that are directly threatening human life and health. Therefore, in the process of food safety supervision, it is crucial to conduct sensitive and rapid detection of pesticide residues. The recognition element is the vital component of sensors and methods for fast testing pesticide residues in food. Improper recognition elements may lead to defects of testing methods, such as poor stability, low sensitivity, high economic costs, and waste of time. We can use the molecular biological technique to address these challenges as a good strategy for recognition element production and modification. Herein, we review the molecular biological methods of five specific recognition elements, including aptamers, genetic engineering antibodies, DNAzymes, genetically engineered enzymes, and whole-cell-based biosensors. In addition, the application of these identification elements combined with biosensor and immunoassay methods in actual detection was also discussed. The purpose of this review was to provide a valuable reference for further development of rapid detection methods for pesticide residues.

Tumor necrosis factor-α upregulates polymeric immunoglobulin receptor expression by NF-κB signaling pathways in grass carp (Ctenopharyngodon idellus) liver cells.

The polymeric immunoglobulin receptor (pIgR) is essential for controlling polymeric immunoglobulin to defend species from invading pathogens. However, the modulation pathway of pIgR expression in teleosts remains unclear. In this paper, to define that the cytokine TNF-α impacted the expression of pIgR, the recombinant proteins of TNF-α of grass carp were first prepared after approving that natural pIgR was expressed in liver cells of grass carp (Ctenopharyngodon idellus) (L8824). L8824 cells were incubated with variable amounts of recombinant TNF-α at various times, the results revealed that pIgR expressions showed a significant dose-dependent elevation at the gene and proteins, and a similar alteration trend was detected for the pIgR protein (secretory component: SC) secreted by L8824 cells into the culture supernatant. Moreover, nuclear factor kappa-B (NF-κB) inhibitors PDTC was used to study whether TNF-α regulated pIgR expressions through the NF-κB signaling pathways. L8824 cells were treated with TNF-α, inhibitor PDTC, and TNF-α + PDTC mixtures, respectively, and the levels of pIgR genes and pIgR protein in cells and SC in the culture supernatant decreased in cells treated with PDTC contrasted to the control, and subjected to reduced expression of PDTC + TNF-α reduced expression contrasted to that treated just with TNF-α, demonstrating that suppression of NF-κB obstructed the ability of TNF-α to elevate pIgR gene and pIgR protein in cells and SC in the culture supernatant. These outcomes indicated that TNF-α raised pIgR gene expression, pIgR protein, and SC creation, and this pIgR expression induced by TNF-α was modulated by complicated pathways that included NF-κB signaling mechanism, confirming TNF-α as a pIgR expression modulator and enhancing a deeper insight of the regulatory pathway for pIgR expression in teleosts.

Engineering Semi-Reversed Quantum Well Photocatalysts for Highly-Efficient Solar-to-Fuels Conversion.

Semiconductor quantum wells (QWs) exhibit high charge-utilization efficiency for light-emitting applications due to their strong charge confinement effect. Inspired by this effect, herein, this work proposes a new idea to significantly improve the photo-generated charge separation for attaining a highly-efficient solar-to-fuels conversion process through "semi-reversing" the conventional QWs to confine only the photo-generated electrons. This electron confinement-improved charge separation is implemented in the well-designed model of the CdS/TiO2/CdS semi-reversed QW (SRQW) structure. The latter is fabricated by selectively assembling CdS quantum dots (QDs) onto the {101} facets (ultra-thin edge regions) of the TiO2 nanosheets (NSs). Upon light excitation, the photo-generated electrons of SRQW can be confined on the TiO2-{101} facets in the vicinity of the CdS/TiO2 hetero-interface. Thereby, the continuous multi-electron injection to the adsorbed reactants on the interfacial active-sites is significantly accelerated. Thus, the CdS/TiO2/CdS SRQW exhibits ≈35.7 and ≈56.0-fold enhancements on the photocatalytic activities for water and CO2 reduction, respectively, compared to those of pure TiO2. Correspondingly, its CH4-product selectivity is increased by ≈180%. This work provides a novel charge separation mechanism, which is of great importance for the design of the next-generation quantum-sized photocatalysts for solar-to-fuels conversion.

The tricarboxylic acid cycle is inhibited under acute stress from carbonate alkalinity in the gills of Eriocheir sinensis.

Owing to population growth and environmental pollution, freshwater aquaculture has been rapidly shrinking in recent years. Aquaculture in saline-alkaline waters is a crucial strategy to meet the increasing demand for aquatic products. The Chinese mitten crab is an important economic food in China, but the molecular mechanism by which it tolerates carbonate alkalinity (CA) in water remains unclear. Here, we found that enzyme activities of the tricarboxylic acid (TCA) cycle in the gills, such as citrate synthase, isocitrate dehydrogenase, α-ketoglutarate dehydrogenase, and malate dehydrogenase, were markedly reduced under CA stress induced by 40 mM NaHCO3. Secondly, the TCA cycle in the gills is inhibited under acute CA stress, according to proteomic and metabolomic analyses. The expressions of six enzymes, namely aconitate hydratase, isocitrate dehydrogenase, 2-oxoglutarate dehydrogenase, dihydrolipoyl dehydrogenase, succinate-CoA ligase, and malate dehydrogenase, were downregulated, resulting in the accumulation of phosphoenolpyruvic acid, citric acid, cis-aconitate, and α-ketoglutaric acid. Finally, we testified that if the TCA cycle is disturbed by malonate, the survival rate increases in CA water. To our knowledge, this is the first study to show that the TCA cycle in the gills is inhibited under CA stress. Overall, the results provide new insights into the molecular mechanism of tolerance to saline-alkaline water in crabs, which helped us expand the area for freshwater aquaculture and comprehensively understand the physiological characteristics of crab migration.

Plasmonic Active "Hot Spots"-Confined Photocatalytic CO2 Reduction with High Selectivity for CH4 Production.

Plasmonic nanostructures have tremendous potential to be applied in photocatalytic CO2 reduction, since their localized surface plasmon resonance can collect low-energy-photons to derive energetic "hot electrons" for reducing the CO2 activation-barrier. However, the hot electron-driven CO2 reduction is usually limited by poor efficiency and low selectivity for producing kinetically unfavorable hydrocarbons. Here, a new idea of plasmonic active "hot spot"-confined photocatalysis is proposed to overcome this drawback. W18 O49 nanowires on the outer surface of Au nanoparticles-embedded TiO2 electrospun nanofibers are assembled to obtain lots of Au/TiO2 /W18 O49 sandwich-like substructures in the formed plasmonic heterostructure. The short distance (< 10 nm) between Au and adjacent W18 O49 can induce an intense plasmon-coupling to form the active "hot spots" in the substructures. These active "hot spots" are capable of not only gathering the incident light to enhance "hot electrons" generation and migration, but also capturing protons and CO through the dual-hetero-active-sites (Au-O-Ti and W-O-Ti) at the Au/TiO2 /W18 O49 interface, as evidenced by systematic experiments and simulation analyses. Thus, during photocatalytic CO2 reduction at 43± 2 °C, these active "hot spots" enriched in the well-designed Au/TiO2 /W18 O49 plasmonic heterostructure can synergistically confine the hot-electron, proton, and CO intermediates for resulting in the CH4 and CO production-rates at ≈35.55 and ≈2.57 µmol g-1 h-1 , respectively, and the CH4 -product selectivity at ≈93.3%.

[Analysis of food sources of Eriocheir sinensis in rice-crab integrated ecosystem based on stable isotopes in saline-alkali land of the Yellow River Delta]. / åŸºäºŽç¨³å®šåŒä½ç´ çš„é»„æ²³ä¸‰è§’æ´²ç›ç¢±åœ°ç¨»èŸ¹ç§å »ç³»ç»Ÿä¸­åŽç»’èž¯èŸ¹é£Ÿç‰©æºåˆ†æž.

To explore food composition of Chinese mitten crab (Eriocheir sinensis) in rice-crab integrated ecosystem in saline-alkali land of the Yellow River Delta, we analyzed carbon and nitrogen stable isotope ratios (δ13C and δ15N) in the crab and that in food sources, including plants (Elodea, Potamogeton crispus, Ceratophyllum demersum, Lemna minor, Oryza sativa stem and leaf, rice grain), animals (benthos, zooplankton), organic debris and artificial feed (compound feed, corn meal) in Kenli District, Dongying, Shandong Province in June to October of 2020. Substantial differences in δ13C and δ15N were found among food sources. The δ13C and δ15N values of different food sources were in a range of -30.09‰--11.24‰ and 0.03‰-12.78‰, respectively, while those of the crab muscle were in range of -24.61‰--20.08‰ and 4.74‰-9.21‰, respectively, indicating diverse food sources for the crab. During the experiment, the contribution rate of different food sources followed the order: plant (46.7%-57.1%)>animal (21.5%-24.5%)>artificial feed (10.9%-21.3%)>organic detritus (7.1%-7.9%). It suggested that the natural bait of the paddy field could meet the feeding needs of Chinese mitten crabs in saline-alkali land. Even the crabs were fed with non-animal artificial feed, the contribution rates of the main food sources were not altered.

Dual-mode detection of organophosphate pesticides in pear and Chinese cabbage based on fluorescence and AuNPs colorimetric assays.

Herein, a dual-mode method based on fluorescent and colorimetric sensor was developed for determination of organophosphate pesticides (OPs). In this study, indoxyl acetate (IDA) was hydrolyzed by esterase into indophenol. Indophenol leads to changes in fluorescence signal and aggregation of gold nanoparticles (AuNPs); ultimately changing the color from red to blue. When OPs exist, the formation of indophenol was inhibited. With increasing the concentrations of OPs, the enhancement rate of fluorescence signal decreases, and the color change of AuNPs weakened gradually. The assay was applied for determination of dichlorvos, trichlorfon, and paraoxon, and the limits of detection (LODs) were 0.0032 mg/kg, 0.0096 mg/kg, and 0.0074 mg/kg (fluorometric assay), and 0.0120 mg/kg, 0.0224 mg/kg, and 0.0106 mg/kg (colorimetric assay), respectively. Finally, such a convenient and sensitive sensing assay was successfully applied for quantification of OPs in pear and Chinese cabbage with good recoveries ranged between 80.19 and 116.93%.

The complete mitochondrial genome of two different colour Luciobarbus capito (Cypriniformes, Cyprinidae).

We sequenced and characterized the complete mitochondrial genome from normal colour (grey black) and mutant colour (orangey red) of Luciobarbus capito. Both mitogenomes contained the typical complement of 13 protein-coding genes, 22 transfer RNAs (tRNAs), two ribosomal RNAs (rRNAs), and a non-coding control region. They share the same gene arrangement pattern that was identical with most vertebrates. The entire mitochondrial DNA molecule of grey black L. capito was 16603-bp long, while the complete mtDNA molecule of orangey red L. capito was 16607-bp long.

The complete mitochondrial genome of golden yellow snakehead fish, Channa argus.

We sequenced and characterized the complete mitochondrial genome of golden yellow snakehead fish, Channa argus. The mitogenomes contained the typical complement of 13 protein-coding genes, 22 transfer RNAs (tRNAs), 2 ribosomal RNAs (rRNAs), and a non-coding control region. They share the same gene arrangement pattern that was identical with most vertebrates. The entire mitochondrial DNA molecule of golden yellow snakehead fish was 16,558 bp long. All information reported in this article will be a useful source of sequence information for general molecular and evolutionary studies of the family Channidae.

[The effect of rhodiola and acetazolamide on the sleep architecture and blood oxygen saturation in men living at high altitude].

OBJECTIVE: To study the changes of sleep architecture and blood oxygen saturation (SaO(2)) during sleep in men living at high altitude, and to investigate the effect of rhodiola and acetazolamide on these sleep indexes. METHODS: Twenty-four men aged 18 to 21 years who had stayed at high altitude (5 380 m above sea level) for 1 year were randomly divided into groups A (treated with oral rhodiola), B (treated with oral acetazolamide) and C (treated with rhodiola + acetazolamide). Their sleep architecture and SaO(2) were recorded for 24 days before and after taking the medicines. RESULTS: Compared with baseline, the waking SaO(2) (WSaO(2)), the lowest SaO(2) (LSaO(2)) and the mean SaO(2) (MSaO(2)) were increased significantly after treatment for 24 days (P < 0.01), and the times of oxygen desaturation >/= 4% per hour (DI4) and the percentage of time spent at SaO(2) below 80% (SIT(80)) were decreased significantly (P < 0.01). After treatment, the NREM I and II was shortened, and III + IV and REM sleep were prolonged (P < 0.01): the total waking time (TWT) was shortened, and the sleep efficiency index (SEI) was markedly increased (P < 0.01). Compared with group A's, groups B's and C's SIT(80) were increased (P < 0.05). CONCLUSION: Both rhodiola and acetazolamide were effective in modulating the sleep architecture and improving the sleep quality in young men living at high altitude, but there was no synergistic effect between rhodiola and acetazolamide.