Rationale The development of analytical screening techniques for pesticides is crucial for preventing and mitigating environmental contamination. Mass spectrometry‐based screening methods differ based on the complexity of the sample matrix and the diversity of the target compounds. One of the major challenges is balancing cost reduction in the extraction process with the optimization of analytical results. This protocol introduces a universal and efficient scheme for the qualitative and quantitative schemes for 45 pesticides within a single analytical run. Methods Water samples were extracted using an SPE column, with the pH adjusted to 7. Soil samples were processed using a modified QuEChERS method. The pretreatment for water samples emphasized selecting appropriate SPE columns and optimizing pH, while for soil samples, the focus was on choosing suitable extraction solvents and extraction salt packages. The enriched samples were then analyzed using liquid chromatography–tandem mass spectrometry (LC–MS/MS). The method was evaluated for accuracy, precision, detection limits, and matrix effects. Results The method enabled the simultaneous detection of 45 pesticides within a 15‐minute analysis period. SPE recoveries ranged from 56.1% to 118.8%. Instrumental detection limits varied between 0.02 and 1 pg, while method detection limits extended from 0.05 to 18.47 ng/l in soil and water matrices. The approach was successfully applied to water and soil samples, with the pesticide concentration ranging from 0.1 ng/L to 38 μg/L. Conclusions The protocol substantially enhances the characterization and quantification of 45 pesticides in environmental samples, achieving a remarkable reduction in detection limits by an order of magnitude compared to previous research. This method enables the simultaneous detection of pesticides in both water and soil matrices using a single system, addressing the challenges of using separate systems for different environmental media. Furthermore, this protocol provides a crucial theoretical foundation for managing and safeguarding against pesticide pollution.
Firstly, the teaching purpose and requirements of the graduation design course of visual communication design specialty are clarified. In the course teaching, the whole course is constructed by selecting topics of regional cultural design of Jingdezhen in the aspects of intangible cultural heritage related projects, Jingdezhen's corporate brand, tourist attraction image design, and college visual image design. Secondly, we pay attention to the sense of form and systematization of the overall design in the design goal of the course, and complete the design and production part of the course through logo design, poster design, packaging design, book design and so on.
Abstract Plants allocate a substantial amount of C belowground for root exudates and for the construction and adjustment of root morphological and architectural traits. What relationships exist between root exudates and other root traits and these relationships change with growing season, however, remain unclear. We quantified the root exudation rate and root morphological traits, including total root length (RL), total root surface area (RS), root diameter (RD), specific root length (SRL), specific root area (SRA) and root tissue density (RTD), and architectural traits, such as branching intensity (BI), and investigated their associations during the rapidly growing season (April and August) and the slowly growing season (December) of three common native tree species, Liquidambar formosana, Michelia maudiae and Schima superba, in subtropical China. We found that the linkages of RD, SRL, SRA, RTD and BI did not change with the growing season, reflecting their highly conservative relationships. The root exudation rate varied significantly with growing season (P < 0.05) and produced various associations with other root traits at different growing seasons. During the rapidly growing season (i.e., April), the exudation rate was the highest and was positively correlated with RL. The exudation rate was the lowest during the slowly growing season (i.e., December) and was negatively associated with RL, RS and RTD. Our findings demonstrate the seasonality of the linkages of root exudation rate with other root traits, which highlights the highly plastic and complex associations of belowground root traits. These findings help to deepen our understanding of plant nutrient acquisition strategies.
To analyze the clinical and genetic characteristics of a boy featuring unexplained developmental delay, malnutrition and distinct facial appearance.Physical examination was carried out for the child. Peripheral blood samples were collected from the child and his parents for the extraction of genomic DNA and trio-whole exome sequencing. Candidate variants were verified by Sanger sequencing.The patient had facial dysmorphism including nasal alae aplasia, scalp defect and teeth deformities, in addition with recurrent diarrhea due to pancreatic exocrine insufficiency. DNA sequencing revealed that he has harbored compound heterozygous variants of the UBR1 gene, namely c.3167C>G (p.S1056X) and c.1911+14C>G, which were inherited from his father and mother, respectively. Database search has suggested the c.3167C>G to be a novel nonsense variant and c.1911+14C>G a known splicing variant. Based on the guidelines of the American College of Medical Genetics and Genomics, the two variants were predicted to be pathogenic and likely pathogenic, respectively.The child was diagnosed with Johanson-Blizzard syndrome due to the compound heterozygous variants of the UBR1 gene. Above finding has enriched the mutational spectrum of the UBR1 gene and provided a basis for genetic counseling for this family.
Thinning forest stands changes biotic and abiotic conditions, subsequently altering understory communities including their photosynthetic characteristics. We investigated the effects of thinning (25% basal area decrease) in a subtropical Pinus massoniana Lamb. plantation at two post-thinning times: 0.5 years (PT 0.5 ) and 2.5 years (PT 2.5 ). Thinning (PT 0.5 and PT 2.5 ) significantly increased understory density (+104.9% and +142.4%, respectively), aboveground biomass (+191.1% and +239.2%, respectively), the Shannon–Wiener index, and the Pielou index and decreased the Simpson index (p < 0.05). Species richness significantly increased at PT 0.5 and decreased at PT 2.5 (p < 0.05). Photosynthetic characteristics of new and old leaves of three dominant species (Woodwardia japonica (Linn. f.) Sm., Dryopteris championii (Benth.) C. Chr., and Dicranopteris dichotoma (Thunb.) Bernh.) showed different variations at 0.5 and 2.5 years after thinning, depending on their various adaptive strategies. Generally, thinning improved leaf carbon fixation capacity of these dominant plants (except W. japonica old leaves). Leaf photosynthetic characteristics of these species exhibited some common changes with respect to leaf morphological attributes and chlorophyll content. Thinning increased new-leaf length (or width) and reduced old-leaf chlorophyll b concentration at PT 0.5 but reduced new-leaf length, specific leaf area, and all-leaf chlorophyll concentration at PT 2.5 . In conclusion, thinning is a useful tool for increasing understory abundance and carbon fixation capacity of some fern species.
CO preferential oxidation (CO-PROX) in H2-rich streams has garnered considerable attention because of the emerging hydrogen economy, including advanced fuel cell technology. Particularly, mass transfer and diffusion at low CO concentrations (1 vol %) are critical factors influencing CO-PROX performance of structured catalyst. In this study, Pt/Fe3O4 catalysts were uniformly coated on honeycomb ceramics, and the stacked arrangement of rotating channels with varying angles (0°, 15°, 30°, and 45°) was proposed to enhance CO diffusion in channels. By employing computational fluid dynamics (CFD), the velocity, CO mole fraction, and pressure were systematically analyzed, and the underlying angle–performance relationship was then elucidated. Through this cost-effective rotation strategy, flow perturbations were induced as gas transitions between monoliths, which prompted a shift from laminar to turbulent flow and altered velocity and reactant distribution. At a rotation angle of 45°, the CO conversion was boosted by 5–13%. This work underscores the pivotal role of our innovative catalyst design in revolutionizing the CO-PROX reactions to pave the way for enhanced efficiency and practical implementation in various industrial applications.
Forest restoration was regarded as a main measure to improve the carbon sequestration ability of forest ecosystems. In this study, we compared the ecosystem carbon stock in wood plantations with naturally regenerated broadleaf forests in Jiulianshan National Nature Reserve. In 1978, the original vegetation was clear cut. Now, the ecosystem carbon stock (vegetation + litter + soil) were about 257.59 t hm-2 in broadleaved secondary forest, 230.93 t hm-2 in Cunninghamia lanceolata plantation, and 163.49 t hm-2 in Nyssa sinensis plantation. The carbon stocks in these relatively new forests were significantly lower than that in the subtropical zonal evergreen broadleaved forests (299.13 t hm-2). We primarily conclude that the carbon stock in secondary forest by natural regeneration was higher than that in plantations by managements. Carbon storages in these restored forests were significantly lower than that zonal vegetation, it means that they still have a certain carbon sink potential. The natural forest regenerations with low investments and labor, which had a slightly disturbance for soil carbon pools, could acquire relatively substantial vegetation carbon stocks compared with plantations. Under favorate environment conditions of water and temperature in subtropical China, the natural restoration was a promising way to achieve high carbon benefits in the forest area with enough seeds sources.
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