查找使用阿拉丁产品的科研文献

Forchlorfenuron detection based on its inhibitory effect towards catalase immobilized on boron nitride substrate

Qin Xu,Lijuan Cai,Huijie Zhao,Jiaqian Tang,Yuanyuan Shen,Xiaoya Hu,Haibo Zeng

An enzymatic procedure based on a catalase biosensor for the detection of forchlorfenuron (CPPU) has been reported in this work. Catalase was immobilized on boron nitride (BN) sheets dispersed in chitosan by adsorption. The immobilized catalase exhibited direct electron transfer character and excellent electrocatalytic activity towards H 2 O 2 reduction. After introducing CPPU into the H 2 O 2 containing phosphate buffer solution , the catalase-catalyzed H 2 O 2 reduction current decreased. By measuring the current decrease, CPPU can be determined in the range of 0.5–10.0   µM with the detection limit of 0.07   μM. The non-competitive inhibition behavior of CPPU towards catalase was verified by the Lineweaver–Burk plots. Long stability character has been ascribed to this biosensor. Possible use of this biosensor in flow systems is illustrated. The proposed biosensor has been successfully applied to CPPU determination in fruits samples with satisfactory results.

New insights into clopyralid degradation by sulfate radical: Pyridine ring cleavage pathways

Xuerui Yang,Xi Ding,Lei Zhou,Huan-huan Fan,Xingbao Wang,Corinne Ferronato,Jean-Marc Chovelon,Guangli Xiu

Contamination by herbicides such as clopyralid (CLP) poses a significant threat to human health and ecological systems. In the present study, efficient removal of CLP was achieved by thermo activated persulfate, among which sulfate radical was identified as the predominant oxidizing species responsible for the decontamination . Based on high resolution LC-MS, derivatization method and density functional theory (DFT) computation, the detailed oxidation pathways and mechanisms were proposed. The primary oxidation pathways included dechlorination-hydroxylation, decarboxylation and the formation of quinone-like moieties. Afterwards, numerous intermediate byproducts ranging from high molecular to very small ones were identified, suggesting the pyridine ring was damaged during the thermo activated persulfate process. The detected products containing six and five carbons indicated the pyridine ring cleavage would take place on the quinone-structure intermediate. Further oxidation could continue by breaking each bond on the ring-cleavage product, yielding a series of short-chain carbonyl chemicals, carboxylic acids and inorganic ions. In addition, the presence of dissolved oxygen (DO) was favorable to CLP degradation, indicating DO played an important role in applying such technology . The degradation rate constants of CLP increased appreciably with increasing temperature, and acidic pH facilitated the CLP degradation. The results obtained in this work would increase our understanding on the environmental fates of nitrogen heterocyclic compounds during sulfate radical (SO 4 •− )-based advanced oxidation processes (SR-AOPs).

Dissipation behavior, residue dynamics, and dietary risk assessment of forchlorfenuron in postharvest kiwifruits during simulated cold chain logistics and store shelf life

Zhu Difeng,Ping Li,Qian Renyun,Chen Chao,Hong Yawen,Tong Zhenxuan,Yang Xiaochun

Forchlorfenuron (CPPU) is often applied during the cultivation of kiwifruit to produce larger fruit. To address degradation patterns of CPPU during simulated cold chain logistics and simulated shelf life of the fruit after harvest, appropriate storage methods and safe consumption behavior can be investigated. In this study, an ultra-high-performance liquid chromatography-tandem mass spectrometry method was adopted to detect CPPU residues under different conditions. CPPU in kiwifruit stored at 6 °C had a half-life of 40.8–77.0 days. However, when kiwifruit was stored at 0 °C under simulated cold chain storage conditions, the half-life of CPPU was 63.0–115.5 days, implying that lower storage temperatures can reduce the degradation rate of CPPU. The residues of CPPU in kiwifruit pulp declined with time, and the reduction followed the first-order kinetics equation. More CPPU residues were present in the pulp of postharvest kiwifruit treated with exogenous ethylene than in the pulp of untreated kiwifruit. Thus, using exogenous ethylene for artificial ripening after harvest is not recommended. We determined that the appropriate cold chain storage temperature is 6 °C. It is recommended that the public select kiwifruit stored for at least 2 weeks. The estimated chronic and acute dietary risk quotients of CPPU are ≤ 0.79% and ≤ 0.11%, respectively. Therefore, it is highly unlikely that consumers will be poisoned by CPPU due to kiwifruit consumption. Our results provide scientific evidence regarding the adoption of appropriate kiwifruit storage methods and consumption behavior to enhance consumption safety.

Regenerating Saffron (Crocus sativus L.) from Corm Lateral Buds via Indirect Somatic Embryogenesis

Yangyang Ma,Yiyu Pan,Bizeng Mao

Saffron (Crocus sativusL.), being one of the distinguished commercial spice crops in the world, is in demand for its culinary, colorant, and pharmaceutical benefits. In this study, a novel indirect somatic embryogenesis (SE) system was, thus, established for the study of this plant. To this end, firstly, the lateral buds were cultured. Then, the cultures were transformed using Murashige and Skoog (MS) medium supplemented with either 6-benzyladenine (BA: 5 and 10 mg/L), naphthalene acetic acid (NAA: 0, 1, and 2 mg/L), or trans-zeatin (tZ: 0, 0.5, and 1.0 mg/L), before being classified into four structures: white globular (WG), yellow compact nodular (YCN), yellow-brown fragile (YBF), and dark-brown porous (DBP). As soon as BA (10 mg/L) and NAA (2 mg/L) were added, elevated percentages of white globular calli (56.8%) and white globular calli (31.5%) structures were induced. Additionally, 6-benzyladenine (5 mg/L) and naphthalene acetic acid (1 mg/L) allowed the formation of yellow-brown fragile structures, and the combination of 6-benzyladenine (10 mg/L) with trans-zeatin (1 mg/L) formed the DBP structures. After three months, the white globular calli were incubated using the MS basal medium, before being augmented with thidiazuron (TDZ: 1 mg/L) and picloram (PIC: 2 mg/L), from which 60% of the cases matured into shoots and, ultimately, cormlets. Morphoanatomical analyses also showed that the white globular calli cells were closely arranged, as they had a dense cytoplasm, a significant vascular differentiation, and embryoids. Furthermore, the yellow compact nodular structures were characterized by a strong differentiation capacity and contained many meristematic cells with high caryomitosis centers. We observed that the yellow-brown fragile calli had looser cell arrangements, with a vascular structure located on the protoderm edge, while there was no obvious cellular arrangement in the dark-brown porous structures. The induction of the adventitious buds in vivo on the MS medium that was supplemented with thidiazuron and picloram accordingly demonstrated the highest rates (60%) of white globular calli.Keywords:Crocus sativus;differentiation;morpho-histological;somatic embryogenesis

Mesoporous Poly (Melamine–Formaldehyde) Resin as an Efficient Adsorbent for the Removal of Forchlorfenuron Pesticide from Water

Wang Tong,Yang AiGuo,Zhang JiuBing,Gan WeiJiang,Zhou Fan,Ran ZhaoJin,Wang ZhongMin

Pesticide residues in water can cause varying degrees of damage to the ecological system and human health, attracting widespread attention. During this research, a cost-effective, easily synthesized, and high surface area mesoporous poly (melamine–formaldehyde) (mPMF) was employed as an adsorbent to effectively absorb forchlorfenuron (CPPU) pesticide from water. The maximum adsorption capacity and maximum adsorption effectiveness were found to be 231.43 mg/g and 81%, respectively. The study of adsorption kinetics revealed that the adsorption mechanism conforms to a quasi-second-order kinetic model, indicating that chemical adsorption predominates, and the overall adsorption process is influenced by two or more factors. The adsorption isotherm experiment demonstrated that the adsorption mechanism is better described by the Freundlich model, suggesting that mPMF exhibits multi-layer heterogeneous adsorption of CPPU, involving both physical and chemical adsorption mechanisms. Additionally, mPMF showed the potential for cyclic regeneration through desorption after adsorbing CPPU from water, as its adsorption capacity remained largely unaffected even after four consecutive cycles.

Solid-liquid equilibrium of forchlorfenuron in four binary solvents: Experiments, hansen solubility parameter and molecular simulation

Yueru Wang,Hansong Wang,Jiaxuan Chen,Bolun Mei,Yu Li,Tao Li,Baozeng Ren

In this research, the solubility of forchlorfenuron in 4 binary solvent systems {(methanol, ethanol, n-propanol and acetone) + water} was determined at certain experimental conditions (pressure of 101.3 kPa, temperature of 278.15 K-323.15 K) using laser dynamic monitoring method. Five thermodynamic models were applied to correlate and analyze the experimentally measured data. The modified Apelblat model has the lowest value of ARD (100 ARD  = 2.046 %) indicates that it fits best. The apparent thermodynamic properties during the dissolution process of forchlorfenuron in the four mixed solvent systems were explored using Van't Hoff equation. The effect of solvent properties on the dissolution was explored by calculating Hansen solubility parameters. For further understanding the solubility behavior on the molecular scale, molecular electrostatic potential analysis and Hirshfeld surface analysis were conducted to visualize the molecular surface charge distribution and predict the contact behavior between forchlorfenuron and solvent. Finally, the influence of intermolecular interactions between solute and solvent on solubility behavior was explored using radial distribution function analysis based on molecular dynamics simulations. And the results show the stronger intermolecular force corresponds to the larger solubility.

Hypoxia exposure impairs male fertility via inhibiting Septin2-mediated spermatogonial proliferation

Li Zhibin,Li Shuying,Xiao Yufeng,Guo Junfeng,Zhou Jianchun,Chen Yang,Yang Juan,Gong Chunli,He Bing,Wu Yuyun,Gao Nannan,Yang Huan,Gao Limin,Hu Hua,Zhang Yunfang,Yang Shiming

What are the molecular mechanisms underlying hypoxia-induced male reproductive impairment?Hypoxia compromises Septin2 (Sept2) transcription in spermatogonia, which impedes spermatogonial proliferation through protein phosphatase 2A (PP2A)-dependent AKT dephosphorylation.Hypoxia is associated with impaired spermatogenesis and poor sperm parameters in men. Spermatogonia proliferation, a crucial early step in spermatogenesis, is essential for maintaining the spermatogenic cell population and ensuring sperm quality. However, the connection between hypoxia and spermatogonial proliferation remains poorly understood, and treatment options for hypoxia-related reproductive disorders are limited.A cross-sectional study analyzed semen samples from 24 high-altitude (HA) residents, 6 pathological hypoxia (PH) patients, and 19 healthy controls to evaluate hypoxia-associated sperm parameter alterations. Complementary animal studies employing a hypobaric chamber-induced hypoxic mouse model (n = 5) confirmed reproductive impairments through assessment of birth rates, sperm quality, and testicular histopathology. Transcriptomic profiling of hypoxic versus normoxic mouse testes (n = 3/group) identified spermatogonial proliferation defects as a predominant pathological feature and pinpointed Sept2 as a candidate mediator. Subsequent mechanistic investigations employed in vitro hypoxic culture of spermatogonial cell lines under hypoxic conditions coupled with pharmacological modulation of PP2A activity in mice (n = 3-5 per intervention group) to delineate the underlying molecular pathways.Semen parameters were evaluated using computer-assisted sperm analysis (CASA; for sperm concentration, count, and motility), morphological staining (Pap staining for sperm deformity), and eosin-nigrosin staining (for sperm viability). In hypoxic mouse model, fertility outcomes were assessed through fertility assessment (mating experiments), sperm parameters (CASA), testicular histology (H&E staining), and spermatogonia proliferation (immunohistochemistry and qPCR). In hypoxic spermatogonial cell models, cell proliferation was detected using CCK-8, EdU incorporation, flow cytometry, and western blotting. Sept2 manipulation (knockdown/overexpression), followed by mechanistic analyses (dual-luciferase reporter assay, DNA pulldown/mass spectrometry, TMT-based quantitative proteomics, co-immunoprecipitation, etc), was performed to investigate the mechanism underlying hypoxia-regulated spermatogonia proliferation. The SEPT2 inhibitor forchlorfenuron (FCF), the PP2A agonists celastrol, erlotinib, and FTY720, as well as PP2A inhibitor okadaic acid (OA) were used to investigate the role of the SEPT2-PP2A-AKT axis in male fertility regulation.Both human populations (HA residents and PH patients) and mouse model consistently demonstrated hypoxia-related reproductive dysfunction. Mechanistic analyses revealed that hypoxia significantly downregulated Sept2 expression in spermatogonia, concomitant with impaired proliferative capacity. Sept2 knockdown in normoxic mice the hypoxia-induced defects in spermatogenesis. Complementary in vitro studies confirmed that Sept2 depletion impaired spermatogonial proliferation by inducing G1-S phase arrest, while its overexpression mitigated hypoxia-related proliferative defects. Further investigation revealed that hypoxia disrupts Sept2 transcription by interfering with the binding of RNA polymerase II subunit A (POLR2A) to the Sept2 promoter. The consequent reduction in Sept2 expression led to stabilization of the B56γ regulatory subunit of PP2A, resulting in enhanced AKT dephosphorylation and subsequent suppressed proliferation. Pharmacological intervention with the PP2A inhibitor OA restored reproductive competence and sperm quality in hypoxic mice, whereas PP2A agonists exacerbated these deficits.RNA-seq data are deposited in China National Center for Bioinformation (CNCB) under accession number PRJCA035733.This study focused on the effects of hypoxia on sperm parameters. Additional factors such as alterations in reproductive hormones and sexual function may contribute to hypoxia-induced infertility and warrant further research.This study identifies the SEPT2-PP2A/B56γ-AKT axis as a key regulator in hypoxia-related spermatogonia proliferation impairment. PP2A inhibitors such as OA may offer a therapeutic strategy to protect male fertility under hypoxic conditions.This work was supported by the National Natural Science Foundation of China (No. 82101688) and Natural Science Foundation of Chongqing (No. CSTB2022NSCQ-MSX0943). The authors have no conflicts of interest to declare.

Imidazolium ionic-liquid-modified phenolic resin for solid-phase extraction of thidiazuron and forchlorfenuron from cucumbers

Pengfei Li,Yanke Lu,Jiangxue Cao,Mengyuan Li,Chunliu Yang,Hongyuan Yan

An imidazolium ionic-liquid-modified phenolic resin (ILPR) was synthesized using 3-aminophenol as a functional monomer, glyoxylic acid as a green cross-linker, and polyethylene glycol 6000 as a porogen. The obtained ILPR showed better extraction of benzoylurea plant hormones thidiazuron and forchlorfenuron than the unmodified phenolic resin because the imidazolium IL provides more interaction modes with the analytes. ILPR, as a tailored adsorbent for solid-phase extraction, was coupled with high-performance liquid chromatography (ILPR‒SPE‒HPLC) for the simultaneous determination of thidiazuron and forchlorfenuron in cucumbers. Good linearity of the ILPR‒SPE‒HPLC method was obtained, ranging from 0.0100 to 5.00 μg g −1 with a correlation coefficient ( r ) ≥ 0.9999. The recoveries of spiked samples ranged from 91.4% to 100.7% with a relative standard deviation of ≤ 6.0%.

A simplified dispersive solid-phase extraction using a shaped zirconium-based metal–organic framework: Constructing a novel, facile and efficient method for detecting plant growth regulators in citrus fruits

Qingqing Zhang,Xuejin Mao,Changrong Yuan,Jiexue Zhao,Hui Hu,Aiping Yan,Yuanxing Wang,Weiming Xiao

A facile, efficient and reliable method was designed and established to analyze the plant growth regulators (PGRs) in citrus fruit, based on a simplified dispersive solid-phase extraction (d-SPE) using a shaped zirconium-based metal–organic framework (UiO-66-PDMS bead) as the sorbent. In this method, UiO-66-PDMS beads directly extracted the targets from the homogenized and could be easily separated with a tweezer. It avoided the centrifugation or filtration operation required in normal d-SPE, greatly simplifying the d-SPE process. Moreover, the matrix substances were efficiently removed by this d-SPE process. The method showed good linearities (R 2  ≥ 0.9995) and limits of detection (0.09–0.17 ng/g). The recoveries were in the range of 80.7–97.5 %. The intra-day and inter-day precisions were 1.5–6.3 % and 4.6–11.7 %, respectively. Additionally, the adsorption interactions between UiO-66-PDMS bead and PGRs were studied by ATR-FTIR and UV–vis DRS. Furthermore, the method was employed to screen the PGRs in ten different citrus fruits.

Rapid analysis of forchlorfenuron in fruits using molecular complex-based dispersive liquid–liquid microextraction

Yanmei Ren,Ping Xiang,Qilong Xie,Haixiu Yang,Shuhui Liu

Chemiluminescence method based on the KIO4−K2CO3−Mn2+ reaction for rapid and sensitive determination of forchlorfenuron in dried fruit

Baisen Chen,Rongxia Tan,Yufei Hu,Gongke Li

Forchlorfenuron is a low-toxic phenylurea plant growth regulator. Excessive intake of forchlorfenuron can lead to metabolic disorders of the matrix and be harmful to human health. The chemiluminescence intensity of the KIO 4 –K 2 CO 3 –Mn 2+ reaction decreased in the presence of forchlorfenuron. Based on this result, a rapid and sensitive chemiluminescence method was established to determine forchlorfenuron by combining it with a batch injection static device. The injection speed, injection volume and reagent concentration of the forchlorfenuron–KIO 4 –K 2 CO 3 –Mn 2+ chemiluminescence reaction were optimized. Under these optimized conditions, the linear range of the method was 1.0–200.0 μg/L, and the limit of detection was 0.29 μg/L (S/N = 3). The chemiluminescence method for the determination of forchlorfenuron could be completed in 10 s. The method was applied to detect the residual forchlorfenuron in dried fruit samples, and the results are consistent with high-performance liquid chromatography-mass spectrometry. This method has the advantages of high sensitivity, rapid response, less reagent consumption, and convenient operation. It will provide a new perspective for chemiluminescence for the rapid and sensitive determination of forchlorfenuron in various complex samples.