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1.
Nano Lett ; 24(14): 4209-4216, 2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38557205

RESUMO

Optical nonlinear processes are indispensable in a wide range of applications, including ultrafast lasers, microscopy, and quantum information technologies. Among the diverse nonlinear processes, second-order effects usually overwhelm the higher-order ones, except in centrosymmetric systems, where the second-order susceptibility vanishes to allow the use of the third-order nonlinearity. Here we demonstrate a hybrid photonic platform whereby the balance between second- and third-order susceptibilities can be tuned flexibly. By decorating ultra-high-Q silica microcavities with atomically thin tungsten diselenide, we observe cavity-enhanced second-harmonic generation and sum-frequency generation with continuous-wave excitation at a power level of only a few hundred microwatts. We show that the coexistence of second- and third-order nonlinearities in a single device can be achieved by carefully choosing the size and location of the two-dimensional material. Our approach can be generalized to other types of cavities, unlocking the potential of hybrid systems with controlled nonlinear susceptibilities for novel applications.

2.
Mol Cancer Ther ; 2024 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-38647536

RESUMO

Hepatocellular carcinoma (HCC) has a pathogenesis that remains elusive with restricted therapeutic strategies and efficacy. This study aimed to investigate the role of SMG5, a crucial component in nonsense-mediated mRNA decay (NMD) that degrades mRNA containing a premature termination codon (PTC), in HCC pathogenesis and therapeutic resistance. We demonstrated an elevated expression of SMG5 in HCC and scrutinized its potential as a therapeutic target. Our findings revealed that SMG5 knockdown not only inhibited the migration, invasion, and proliferation of HCC cells but also influenced sorafenib resistance. Differential gene expression analysis between the control and SMG5 knockdown groups showed an upregulation of MAT1A in the latter. High expression of MAT1A, a catalyst for S-adenosylmethionine (SAM) production, as suggested by TCGA data, was indicative of a better prognosis for HCC. Further, an enzyme-linked immunosorbent assay showed a higher concentration of SAM in SMG5 knockdown cell supernatants. Furthermore, we found that exogenous SAM supplementation enhanced the sensitivity of HCC cells to sorafenib alongside changes in the expression of Bax and Bcl 2, apoptosis-related proteins. Our findings underscore the important role of SMG5 in HCC development and its involvement in sorafenib resistance, highlighting it as a potential target for HCC treatment.

3.
Chem Sci ; 15(11): 3928-3935, 2024 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-38487225

RESUMO

Anion exchange membrane fuel cells are a potentially cost-effective energy conversion technology, however, the electrocatalyst for the anodic hydrogen oxidation reaction (HOR) suffers from sluggish kinetics under alkaline conditions. Herein, we report that Ru-based nanosheets with amorphous-crystalline heterointerfaces of Ru and Ti-doped RuO2 (a/c-Ru/Ti-RuO2) can serve as a highly efficient HOR catalyst with a mass activity of 4.16 A mgRu-1, which is 19.8-fold higher than that of commercial Pt/C. Detailed characterization studies show that abundant amorphous-crystalline heterointerfaces of a/c-Ru/Ti-RuO2 nanosheets provide oxygen vacancies and unsaturated coordination bonds for balancing adsorption of hydrogen and hydroxyl species on Ru active sites to elevate HOR activity. Moreover, Ti doping can facilitate CO oxidation, leading to enhanced strength to CO poisoning. This work provides a strategy for enhancing alkaline HOR performance over Ru-based catalysts with heteroatom and heterointerface dual-engineering, which will attract immediate interest in chemistry, materials science and beyond.

4.
Se Pu ; 42(3): 256-263, 2024 Mar 08.
Artigo em Chinês | MEDLINE | ID: mdl-38503702

RESUMO

Herbicides play an important role in preventing and controlling weeds and harmful plants and are increasingly used in agriculture, forestry, landscaping, and other fields. However, the effective utilization rate of herbicides is only 20%-30%, and most herbicides enter the atmosphere, soil, sediment, and water environments through drift, leaching, and runoff after field application. Herbicide residues in the environment pose potential risks to ecological safety and human health. Therefore, establishing analytical methods to determine herbicide residues in environmental samples is of great importance. In this study, an analytical method based on liquid chromatography-tandem mass spectrometry (LC-MS/MS) in positive electrospray ionization mode (ESI+) was developed for the determination of isoxaflutole, metazachlor, and saflufenacil residues in soil, sediment, and water. The instrumental detection parameters, including electrospray ionization mode, mobile phase, and chromatographic column, were optimized. The mobile phases were methanol (A) and 0.1% formic acid aqueous solution (B). Gradient elution was performed as follows: 0-1.0 min, 60%A; 1.0-2.0 min, 60%A-90%A; 2.0-3.0 min, 90%A; 3.0-4.0 min, 90%A-60%A; 4.0-5.0 min, 60%A. The samples were salted after extraction with acetonitrile and cleaned using a C18 solid-phase extraction column. Different solid-phase extraction columns and leaching conditions were investigated during sample pretreatment. Working curves in the neat solvent and matrix were constructed by plotting the measured peak areas as a function of the concentrations of the analytes in the neat solvent and matrix. Good linearities were found for isoxaflutole, metazachlor, and saflufenacil in the solvent and matrix-matched standards in the range of 0.0005-0.02 mg/L, with r≥0.9961. The matrix effects of the three herbicides in soil, sediment, and water ranged from -10.1% to 16.5%. The limits of detection (LODs, S/N=3) for isoxaflutole, metazachlor, and saflufenacil were 0.05, 0.01, and 0.02 µg/kg, respectively. The limits of quantification (LOQs, S/N=10) for isoxaflutole, metazachlor, and saflufenacil were 0.2, 0.05, and 0.05 µg/kg, respectively. The herbicides were applied to soil, sediment, and water at spiked levels of 0.005, 0.1, and 2.0 mg/kg, respectively. The average recoveries for isoxaflutole, metazachlor, and saflufenacil in soil, sediment, and water were in the ranges of 77.2%-101.9%, 77.9%-105.1%, and 80.8%-107.1%, respectively. The RSDs for isoxaflutole, metazachlor, and saflufenacil were in the ranges of 1.4%-12.8%, 1.2%-7.7%, and 1.5%-11.5%, respectively. The established method was used to analyze actual samples collected from four different sites in Zhejiang Province (Xiaoshan, Taizhou, Dongyang, and Yuhang) and one site in Heilongjiang (Jiamusi). The proposed method is simple, rapid, accurate, stable, and highly practical. It can be used to detect isoxaflutole, metazachlor, and saflufenacil residues in soil, sediment, and water and provides a reference for monitoring the residual pollution and environmental behavior of herbicides.


Assuntos
Acetamidas , Herbicidas , Pirimidinonas , Sulfonamidas , Humanos , Cromatografia Líquida , Herbicidas/análise , Cromatografia Líquida de Alta Pressão , Espectrometria de Massas em Tandem/métodos , Água/análise , Solo/química , Solventes/análise , Extração em Fase Sólida
5.
Mol Plant Pathol ; 25(2): e13438, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38393695

RESUMO

Pectin has been extensively studied in animal immunity, and exogenous pectin as a food additive can provide protection against inflammatory bowel disease. However, the utility of pectin to improve immunity in plants is still unstudied. Here, we found exogenous application of pectin triggered stomatal closure in Arabidopsis in a dose- and time-dependent manner. Additionally, pectin activated peroxidase and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase to produce reactive oxygen species (ROS), which subsequently increased cytoplasmic Ca2+ concentration ([Ca2+ ]cyt ) and was followed by nitric oxide (NO) production, leading to stomatal closure in an abscisic acid (ABA) and salicylic acid (SA) signalling-dependent mechanism. Furthermore, pectin enhanced the disease resistance to Pseudomonas syringae pv. tomato DC3000 (Pst DC3000) with mitogen-activated protein kinases (MPKs) MPK3/6 activated and upregulated expression of defence-responsive genes in Arabidopsis. These results suggested that exogenous pectin-induced stomatal closure was associated with ROS and NO production regulated by ABA and SA signalling, contributing to defence against Pst DC3000 in Arabidopsis.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Pectinas/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Estômatos de Plantas/genética , Ácido Abscísico/farmacologia , Ácido Abscísico/metabolismo
6.
J Environ Sci Health B ; 59(4): 152-159, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38347689

RESUMO

Picoxystrobin is a systemic fungicide widely used on potato, citrus fruit, and Dendrobium officinale. To provide information for the risk assessment of potato, citrus, and Dendrobium officinale, field experiments combined with QuEChERS and HPLC-MS/MS were performed to detect picoxystrobin. Picoxystrobin had good linearity (R2 > 0.99), the average recovery rate was 75 - 102%, and the relative standard deviation was 1 - 11%. Picoxystrobin was utilized as the test agent in field experiments, and samples were evaluated and analyzed at various times after the final application utilizing random sampling. The results showed that picoxystrobin residuals in potato and citrus (orange meat) were ˂ 0.01 mg kg-1, whereas those in citrus whole fruit, D. officinale (fresh), and D. officinale (dried) were < 0.05 - 0.084, 0.16 - 3.82, and 0.34 - 9.05 mg kg-1, respectively. Based on these results, both the acute risk quotient (2.77%) and chronic risk quotient (8.7%) were ˂100%, and the dietary risk assessment indicated that the intake of picoxystrobin residues in potato, citrus fruit, and D. officinale did not pose a health risk. This study can guide the reasonable use of picoxystrobin in potato, citrus fruit, and D. officinale.


Assuntos
Citrus , Dendrobium , Solanum tuberosum , Estrobilurinas , Espectrometria de Massas em Tandem/métodos , Medição de Risco
7.
Environ Pollut ; 346: 123601, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38373624

RESUMO

The pesticide application method is one of the important factors affecting its effectiveness and residues, and the risk of pesticides to non-target organisms. To elucidate the effect of application methods on the efficacy and residue of cyenopyrafen, and the toxic effects on pollinators honeybees in strawberry cultivation, the efficacy and residual behavior of cyenopyrafen were investigated using foliar spray and backward leaf spray in field trials. The results showed that the initial deposition of cyenopyrafen using backward leaf spray on target leaves reached 5.06-9.81 mg/kg at the dose of 67.5-101.25 g a.i./ha, which was higher than that using foliar spray (2.62-3.71 mg/kg). The half-lives of cyenopyrafen in leaves for foliar and backward leaf spray was 2.3-3.3 and 5.3-5.9 d, respectively. The residues (10 d) of cyenopyrafen in leaves after backward leaf spray was 1.41-3.02 mg/kg, which was higher than that after foliar spraying (0.25-0.37 mg/kg). It is the main reason for the better efficacy after backward leaf spray. However, the residues (10 d) in strawberry after backward leaf spray and foliar spray was 0.04-0.10 and < 0.01 mg/kg, which were well below the established maximum residue levels of cyenopyrafen in Japan and South Korea for food safety. To further investigate the effects of cyenopyrafen residues after backward leaf spray application on pollinator honeybees, sublethal effects of cyenopyrafen on honeybees were studied. The results indicated a significant inhibition in the detoxification metabolic enzymes of honeybees under continuous exposure of cyenopyrafen (0.54 and 5.4 mg/L) over 8 d. The cyenopyrafen exposure also alters the composition of honeybee gut microbiota, such as increasing the relative abundance of Rhizobiales and decreasing the relative abundance of Acetobacterales. The comprehensive data on cyenopyrafen provide basic theoretical for environmental and ecological risk assessment, while backward leaf spray proved to be effective and safe for strawberry cultivation.


Assuntos
Acrilonitrila/análogos & derivados , Fragaria , Praguicidas , Abelhas , Animais , Pirazóis
8.
J Clin Med ; 13(1)2024 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-38202262

RESUMO

Immune-related adverse events (irAEs) of immunotherapy would lead to the temporary or permanent discontinuation of immune checkpoint inhibitors (ICIs). Among them, checkpoint inhibitor pneumonitis (CIP) is a potentially life-threatening irAE. This study aimed to identify the differences between patients with low-grade CIPs (grades 1-2) and high-grade CIPs (grades 3-5) and to explore the prognostic factors. We retrospectively reviewed the medical records of 916 lung cancer patients who were treated with ICIs. Patients with CIPs were identified after multidisciplinary discussion, and their clinical, laboratory, radiological, and follow-up data were analyzed. Among the 74 enrolled CIP patients, there were 31 low-grade CIPs and 43 high-grade CIPs. Compared with low-grade CIP patients, patients with high-grade CIPs were older (65.8 years vs. 61.5 years) and had lower serum albumin (35.2 g/L vs. 37.9 g/L), higher D-dimer (5.1 mg/L vs. 1.7 mg/L), and more pulmonary infectious diseases (32.6% vs. 6.5%) during follow-up. In addition, complication with pulmonary infectious diseases, management with intravenous immunoglobulin, tocilizumab, and longer duration of large dosage corticosteroids might be associated with worse outcomes for patients with CIPs. This study highlights potential risk factors for high-grade CIP and poor prognosis among lung cancer patients who were treated with anti-cancer ICIs.

9.
BMC Pediatr ; 24(1): 5, 2024 01 03.
Artigo em Inglês | MEDLINE | ID: mdl-38172693

RESUMO

OBJECTIVE: In this study, we aimed to enhance the treatment protocols and help understand the harm caused by the accidental ingestion of magnetic beads by children. METHODS: Data were collected from 72 children with multiple gastrointestinal perforations or gastrointestinal obstructions. The 72 pediatric patients were divided into a perforation and a non-perforation group. The data collected for the analysis included the gender, age, medical history, place of residence (rural or urban), and symptoms along with the educational background of the caregiver, the location and quantity of any foreign bodies discovered during the procedure, whether perforation was confirmed during the procedure, and the number of times magnetic beads had been accidentally ingested. RESULTS: The accuracy rate of preoperative gastrointestinal perforation diagnosis via ultrasound was 71%, while that of the upright abdominal X-ray method was only 46%. In terms of symptoms, the risk of perforation was 13.844 and 12.703 times greater in pediatric patients who experienced vomiting and abdominal pain with vomiting and abdominal distension, respectively, compared to patients in an asymptomatic state. There were no statistical differences between the perforation and the non-perforation groups in terms of age, gender, medical history, and the number of magnetic beads ingested (P > 0.05); however, there were statistical differences in terms of white blood cell count (P = 0.048) and c-reactive protein levels (P = 0.033). A total of 56% of cases underwent a laparotomy along with perforation repair and 19% underwent gastroscopy along with laparotomy. All pediatric patients recovered without complications following surgery. CONCLUSION: Abdominal ultrasonography and/or upright abdominal X-ray analyses should be carried out as soon as possible in case of suspicion of accidental ingestion of magnetic beads by children. In most cases, immediate surgical intervention is required. Given the serious consequences of ingesting this type of foreign body, it is essential to inform parents and/or caregivers about the importance of preventing young children from using such products.


Assuntos
Corpos Estranhos , Trato Gastrointestinal , Humanos , Criança , Pré-Escolar , Trato Gastrointestinal/cirurgia , Corpos Estranhos/diagnóstico por imagem , Corpos Estranhos/cirurgia , Corpos Estranhos/complicações , Vômito/etiologia , Ingestão de Alimentos , Fenômenos Magnéticos
10.
Comput Methods Programs Biomed ; 244: 107996, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38176328

RESUMO

BACKGROUND: Interfragmentary motion (IFM) is a complex state that significantly impacts the healing process of fractures following implant placement. It is crucial to fully consider the IFM state after implantation in the design and biomechanical testing of implants. However, current finite element analysis software lacks direct tools for calculating IFM, and existing IFM tools do not offer a comprehensive solution in terms of accuracy, functionality, and visualization. METHODS: In our study, we developed a Python-based algorithm for calculating IFM that addresses limitations. Our algorithm automatically calculated IFM distances, sliding distances, gaps, as well as the angles and rotation of the two fracture surfaces using all nodes on both sides of the fracture ends. Researchers could input data and selected desired parameters in the interface. The algorithm then performed the necessary calculations and presented the results in a clear and concise manner. The algorithm also provided comprehensive data export capabilities, allowing researchers to customize analyses based on specific needs.To provide a more intuitive demonstration of the calculation process and usage of IFM-Cal, we conducted simulations in Ansys using two rectangular blocks to compare the accuracy and function of three different methods (Point based method, contact tool and IFM-Cal). RESULTS: The point-based method and the contact tool could not accurately calculate IFA, while IFM-Cal could provide a comprehensive evaluation of IFA. In simulation 1, the IFM distances calculated using the point sampling method, contact tool, and IFM-Cal were 2.00 mm, 3.15 mm, and 2.00 mm, respectively. In simulation 2, both the point sampling method and contact tool failed to calculate the interfragmentary angle (IFA), while the IFM-Cal algorithm estimated an angle of -7.87°, which had a small error compared to the ground-truth value of 7.9°. CONCLUSION: We have developed an algorithm for computing IFM which can be utilized in finite element analysis and biomechanical experiments. By conducting comparative simulations with other existing algorithms, we have demonstrated the superior accuracy and expanded evaluation capabilities of our algorithm.


Assuntos
Fraturas Ósseas , Humanos , Análise de Elementos Finitos , Cicatrização , Rotação , Algoritmos , Fenômenos Biomecânicos
11.
Biomed Chromatogr ; 38(2): e5779, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38050189

RESUMO

To clarify the residue behavior and possible dietary risk of abamectin in fresh corn, bitter melon, and Fritillaria, a method was developed for the simultaneous determination of abamectin residues in fresh corn, bitter melon, and Fritillaria by QuEChERS (quick, easy, cheap, effective, rugged, safe) ultra-performance liquid chromatography-tandem mass spectrometry. The mean recovery of abamectin in fresh corn, bitter melon, and Fritillaria was 86.48%-107.80%, and the relative standard deviation was 2.07%-10.12%. The detection rates of abamectin residues in fresh corn, bitter melon, and Fritillaria were 62.50%, 87.50%, and 80.00%, respectively. The residues of abamectin in fresh corn, bitter melon, and Fritillaria were not more than 0.020, 0.019, and 0.087 mg/kg, respectively. Based on these results, dietary risk assessment showed that the risk content of abamectin residues in long- and short-term dietary exposure for Chinese consumers was 61.57% and 0.41%-1.11%, respectively, indicating that abamectin in fresh corn, bitter melon, and Fritillaria in the market would not pose a significant risk to consumers.


Assuntos
Fritillaria , Ivermectina/análogos & derivados , Momordica charantia , Resíduos de Praguicidas , Momordica charantia/química , Zea mays , Medição de Risco , Resíduos de Praguicidas/análise
12.
Chemosphere ; 349: 140747, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38000556

RESUMO

The environmental risks of trifloxystrobin (TR) have drawn attention because of its multiplex toxicity on aquatic organisms, but few studies have paid close attention to its chronic toxicity at environmental concentrations. In present study, histopathology, metabolomics and transcriptomics were comprehensively performed to investigate the toxic effects and biological responses on adult zebrafish after exposure to 0.1, 1 and 10 µg/L TR for 21 d. Results demonstrated long-term exposure of TR affected zebrafish liver, ovary and heart development. Metabolomics revealed 0.1, 1 and 10 µg/L TR simultaneously decreased the carbohydrates enriched in glucose metabolism and ABC transporters pathways, such as glycogen, lactose, lactulose, maltose, maltotriose, d-trehalose, while 1 µg/L and 10 µg/L TR significantly increased many metabolites related to glycerophospholipid and sphingolipid metabolism in zebrafish liver. Transcriptomics showed TR activated the transcription of the Abcb4, Abcb5 and Abcb11 involved in ABC transporters, Pck1, Pfk, Hk, Gyg1a and Pygma related to glucose metabolism, as well as the Lpcat1, Lpcat4, Gpat2, Cers and Sgms in glycerophospholipid and sphingolipid metabolism. Results further demonstrated high concentration of TR strongly affected the DNA repair system, while low dose of TR caused pronounced effects on cardiomyocytes and oocyte regulation pathways at transcriptional levels. The results indicated the abnormal liver, gonad and heart development caused by TR might be ascribed to the disturbance of carbohydrates and lipid metabolism mediating by the Abcb4, Abcb5 and Abcb11 ABC transporters, and long-term exposure of environmental concentration of TR was sufficient to affect zebrafish normal metabolism and development.


Assuntos
Transportadores de Cassetes de Ligação de ATP , Peixe-Zebra , Animais , Feminino , Transportadores de Cassetes de Ligação de ATP/metabolismo , Peixe-Zebra/metabolismo , Metabolismo dos Lipídeos , Glicerofosfolipídeos/metabolismo , Glucose/metabolismo , Esfingolipídeos/metabolismo
13.
Plants (Basel) ; 12(22)2023 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-38005801

RESUMO

Pymetrozine is used on potato (S. tuberosum) and Chrysanthemum morifolium (C. morifolium) to obtain greater yield and quality. However, pesticide use carries the potential for residues to remain and be detected on harvested crops. Therefore, the aim of this study was to estimate pesticide residues in S. tuberosum and C. morifolium products that are commercially available for human consumption and to assess the associated dietary risks. For this study, a total of 340 samples (200 S. tuberosum samples and 140 C. morifolium samples) were collected randomly from supermarkets and farmer's markets. Residues of pymetrozine in S. tuberosum and C. morifolium were detected by using an established and validated QuECHERS-HPLC-MS / MS method, while a dietary risk assessment of pymetrozine in S. tuberosum and C. morifolium was performed using these data. The detection rates of pymetrozine in S. tuberosum and C. morifolium samples were 92.31% and 98.17%, respectively, with residues not more than 0.036 and 0.024 mg/kg, respectively. Based on these results, the dietary risk assessment indicated that the intake of pymetrozine residues in S. tuberosum and C. morifolium does not pose a health risk. This work improved our understanding of the potential exposure risk of pymetrozine in S. tuberosum and C. morifolium.

14.
Chem Commun (Camb) ; 59(79): 11843-11846, 2023 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-37718672

RESUMO

Herein, we demonstrate that the vulcanization of copper nanosheets (Cu2S NSs) can realize selective electrochemical carbon dioxide reduction (CO2RR) to formate (HCOOH). Results from experiments and in situ infrared spectroscopy reveal that Cu2S NSs favor CO2 reduction along the HCOO* pathway, leading to the selective formation of HCOOH. Impressively, the Faraday efficiency (FE) of HCOOH surpasses 70% in a broad potential range from -0.84 to -1.21 V versus (vs.) reversible hydrogen electrode (RHE), with a maximum value of 82%.

15.
Foods ; 12(18)2023 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-37761046

RESUMO

In this study, the fate of two pesticides commonly used on cowpeas, thiamethoxam and pyraclostrobin, during the preparation of home-made pickled cowpeas was investigated using an improved QuEChERS method combined with UHPLC-MS/MS. Although pesticide residues were primarily distributed on cowpea samples, some were transferred to brine. The dissipation half-life of thiamethoxam on cowpea samples was significantly shorter than that of pyraclostrobin due to thiamethoxam's higher water solubility. Thiamethoxam demonstrated a half-life of 5.12 ± 0.66 days, whereas pyraclostrobin exhibited a longer half-life of 71.46 ± 7.87 days. In addition, the degradation half-lives of these two pesticides in the whole system (cowpea and brine) were 45.01 ± 4.99 and 70.51 ± 5.91 days, respectively. This result indicates that the pickling did not effectively promote the degradation of thiamethoxam and pyraclostrobin. The metabolite clothianidin of thiamethoxam was not produced throughout the pickling process, but the metabolite BF 500-3 of pyraclostrobin was detected in cowpea samples. The detection rates for thiamethoxam, pyraclostrobin, and BF 500-3 in the 20 market samples were 10%, 70%, and 45%, respectively. However, the risk quotient analysis indicated that the risk of dietary intake of thiamethoxam and pyraclostrobin in pickled cowpeas by Chinese consumers was negligible.

16.
Ecotoxicol Environ Saf ; 263: 115272, 2023 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-37473704

RESUMO

Pyriclobenzuron 1(PBU) is a novel molluscicide developed to control Pomacea canaliculate, and little information on its environmental fate has been published. In this study, the photolysis of PBU in an aqueous environment was simulated using a xenon lamp. Results showed that the photolysis of PBU in water followed first-order kinetics, exhibiting a t0.5 of 95.1 h and 83.6 h in Milli-Q water and river water, respectively. Two main photolysis products 2(PPs) were detected by HPLC-UV and identified by UPLC-Q/TOF MS, which were formed via the hydroxylation and photocatalytic hydro-dehalogenation of PBU, respectively. The initial relative abundance of photolysis product 1 3(PP-1) in Milli-Q water was 1.55 times higher than that in river water. PP-1 was detected at 26.5 % and 76.8 % of the maximum relative abundance in the river water and Milli-Q water after 720 h, respectively. Photolysis product 2 4(PP-2) was stable in water because of its weak hydrophilicity. The PP-2 detected after 720 h in Milli-Q water and river water was 93.7 % and 93.5 % of the maximum relative abundance, respectively. Finally, ECOSAR software was used to evaluate the acute aquatic toxicity of PBU and its PPs, revealing that the PPs had lower toxicity levels to non-target aquatic organisms.


Assuntos
Luz Solar , Poluentes Químicos da Água , Cinética , Água , Fotólise , Poluentes Químicos da Água/toxicidade
17.
J Hazard Mater ; 452: 131381, 2023 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-37030221

RESUMO

Novel pesticides broflanilide (BFI), afidopyropen (ADP), and flupyradifurone (FPO) have been widely used and become the new organic pollutants. However, uptake, translocation and residual distribution of BFI, ADP, and FPO in plants remain unclear. Therefore, residues distribution, uptake, and translocation of BFI, ADP, and FPO were investigated in mustard field trials and hydroponic experiments. The field results indicated that the residues of BFI, ADP, and FPO were 0.001-1.87 mg/kg at 0-21 d and dissipated fast in mustard (half-lives=5.2-11.3 d). More than 66.5 % of FPO residues were distributed in the cell-soluble fractions because of their high hydrophilicity, while hydrophobic BFI and ADP were primarily stored in the cell walls and organelles. The hydroponic data showed that the foliar uptake rates of BFI, ADP, and FPO were weak (bioconcentration factors<1), but the root uptake rate was strong (bioconcentration factors>1). The upward and downward translations of BFI, ADP, and FPO were limited (translation factor<1). BFI and ADP are uptake by roots via apoplast pathway, and FPO is uptake via symplastic pathway. This study contributes to the understanding of the formation of pesticide residues in plants and provides a reference for safe application and risk assessment of BFI, ADP, and FPO.


Assuntos
Mostardeira , Praguicidas , Mostardeira/metabolismo , Praguicidas/química , Raízes de Plantas/metabolismo
18.
Zhongguo Zhong Yao Za Zhi ; 48(5): 1137-1144, 2023 Mar.
Artigo em Chinês | MEDLINE | ID: mdl-37005799

RESUMO

In order to judge the future development trend of science and technology, plan ahead and lay out the frontier technology fields and directions, China Association of Chinese Medicine(CACM) has launched consultation projects for collecting "major scienti-fic issues and engineering technology difficulties in traditional Chinese medicine(TCM)" for the industry for three consecutive years since 2019. Up to now, 18 projects have been selected as major issues for research, and some experience and achievements have been made. These projects have been applied in important scientific and technological work such as scientific and technological planning and deployment at all levels of national, local, and scientific research institutions, the selection and cultivation of major national scientific and technological projects, and the construction of innovation bases, giving full play to the role of the think tank advisory committee of CACM. This study reviewed the selection of major issues for the first time, systematically combed its application in the national layout of science and technology, and put forward the existing problems and improvement suggestions, aiming to provide new ideas for further improving the selection of major issues and research direction, providing a theoretical basis and decision support for the national scientific and technological layout in the field of TCM, and promoting scientific and technological innovation to facilitate the high quality development of TCM.


Assuntos
Medicamentos de Ervas Chinesas , Medicina Tradicional Chinesa , Invenções , China
19.
Phys Chem Chem Phys ; 25(17): 12220-12230, 2023 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-37073883

RESUMO

The catalytic performance of titanosilicates involving hydrogen peroxide (H2O2) as the oxidant is strongly influenced by the solvents. Until now, there is still a lack of a universal principle that can guide the choice of a solvent. Herein, the kinetics of H2O2 activation catalyzed by various titanosilicates in different solvents is investigated, and an isokinetic compensation effect is concluded. This indicates that the solvent participates in the H2O2 activation process for the formation of a Ti-OOH species. Additionally, the results of isotopically labeled infrared spectra preliminarily confirm that the solvent acts as the mediator to promote the proton transfer during the H2O2 activation process. The catalytic activities of a series of TS-1 catalysts toward 1-hexene epoxidation are compared, which include Ti(OSi)3OH species with a range of densities but a constant total Ti content. This reveals that the solvent effect is closely related to the Ti active sites of these TS-1 catalysts. Based on these results, a principle for the rational choice of solvent for this catalytic process is proposed. ROH is found to be the mediator for Ti(OSi)4 sites, and methanol, which has a strong proton-donating ability, is the best solvent for these sites. However, for the Ti(OSi)3OH sites, water (H2O) is the mediator, and a weaker hydrogen bonding between H2O molecules promotes proton transfer more effectively. The solvent influences the catalytic performance by perturbing the hydrogen bonds between the H2O molecules, and aprotic acetonitrile, which has a strong ability to break the hydrogen bonding network between H2O molecules, is the best solvent for Ti(OSi)3OH sites. This study provides experimental evidence that the solvent promotes the catalytic performance of titanosilicates by assisting the proton transfer during the catalytic H2O2 activation process, which will pave the way toward the rational choice of solvent for the titanosilicate-catalyzed oxidation systems.

20.
Artigo em Inglês | MEDLINE | ID: mdl-36981841

RESUMO

As a new mode of mining development, green mine optimizes the development and utilization of mineral resources with a minimum of the environmental impact, and how to objectively evaluate the construction level of the green mine has become the key to promote green mine construction and it has also been an important path to achieve sustainable development of mineral resources. The evaluation system and methods of green mine construction, however, are not perfect at present as the existing green mine evaluation mostly adopts the index scoring accumulation method, with which the internal relations between the indicators are ignored, and the subjective influence it causes is too large. Based on the framework model of driving forces, pressure, state, impact and response, an indicator system is constructed in this paper to express the internal relationship between indicators more intuitively. Combined with subjective and objective combination weighting method to determine the index weight, TOPSIS and coupling coordination degree models are introduced to quantitatively evaluate the spatio-temporal evolution process of green mine construction and the coupling coordination between subsystems, analyze and obtain the main obstacle factors affecting the green mine construction of enterprises, and provide suggestions and countermeasures for the improvement of green mine construction of enterprises. The applicability of the model is verified by an actual case study of a mine in China. The model enriches the connotation of green mines, making the evaluation process and results fairer and more reliable, thus providing an effective way to promote the sustainable development of mines.


Assuntos
Mineração , Desenvolvimento Sustentável , China
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