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1.
BJU Int ; 2024 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-38837647

RESUMO

OBJECTIVE: To evaluate the safety and effectiveness of endoscopic treatments with Allium® metal ureteric stent (AMUS) for ureteric strictures after kidney transplantation (KT). PATIENTS AND METHODS: In a prospective manner, we gathered clinical data from 68 patients who underwent endoscopic treatments with AMUS for ureteric strictures after KT between January 2019 and March 2022. The definition of surgical success was the unobstructed drainage of the AMUS, or in cases where there was AMUS migration, occlusion or encrustation and subsequently removed, there is no worsening of renal hydronephrosis in the patient during the follow-up period. RESULTS: Based on the specific circumstances of the ureteric strictures, three distinct types of surgery were selected for treatment. The overall success rate of endoscopic treatments for ureteric strictures following KT was 90% (61/68) during a follow-up period of 1 year. Surgical complications included haematuria (18%), pain (10%), urinary tract infections (7.4%), and lower urinary tract symptoms (7.4%). The incidences of stent migration, occlusion, and encrustation were 10%, 2.9%, and 1.5%, respectively. Postoperatively, significant improvements were observed in various parameters. At 1 month after surgery, there was a notable decrease in blood creatinine levels (105.5 vs 90.4 mol/L), urea nitrogen levels (6.6 vs 5.4 mmol/L), and hydronephrosis volume (64.4 vs 43.9 mL). Additionally, the serum estimated glomerular filtration rate increased from 49.5 to 64.4 mL/min/1.73 m2. The follow-up results of patients at 1 year after surgery were similar to those observed at 1 month after surgery. CONCLUSIONS: Systemic endoscopic treatments with AMUS were found to be safe and effective for ureteric strictures after KT with short-term follow-ups. This technique offers a novel option for the treatment of post-KT strictures.

2.
Environ Geochem Health ; 46(7): 231, 2024 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-38849682

RESUMO

Nowadays, there is limited research focusing on the biosorption of Pb2+ through microbial process, particularly at the level of gene expression. To overcome this knowledge gap, we studied the adsorption capacity of Stenotrophomonas rhizophila JC1 to Pb2+, and investigated the physiological mechanism by means of SEM, EDS, FTIR, membrane permeability detection, and investigated the molecular mechanism through comparative transcriptomics. The results showed that after 16 h of cultivation, the biosorption capacity of JC1 for 100 mg/L of Pb2+ reached at 79.8%. The main mechanism of JC1 adsorb Pb2+ is via intracellular accumulation, accounting for more than 90% of the total adsorption. At the physiological level, Pb2+ can precipitate with anion functional groups (e.g., -OH, -NH) on the bacterial cell wall or undergo replacement reaction with cell component elements (e.g., Si, Ca) to adsorb Pb2+ outside of the cell wall, thus accomplishing extracellular adsorption of Pb2+ by strains. Furthermore, the cell membrane acts as a "switch" that inhibits the entry of metal ions into the cell from the plasma membrane. At the molecular level, the gene pbt specificity is responsible for the adsorption of Pb2+ by JC1. In addition, phosphate permease is a major member of the ABC transporter family involved in Pb2+, and czcA/cusA or Co2+/Mg2+ efflux protein plays an important role in the efflux of Pb2+ in JC1. Further, cellular macromolecule biosynthesis, inorganic cation transmembrane transport, citrate cycle (TCA) and carbon metabolism pathways all play crucial roles in the response of strain JC1 to Pb2+ stress.


Assuntos
Chumbo , Chumbo/metabolismo , Adsorção , Stenotrophomonas/metabolismo , Transcriptoma , Biodegradação Ambiental , Regulação Bacteriana da Expressão Gênica , Perfilação da Expressão Gênica , Poluentes Químicos da Água/metabolismo
3.
Insect Mol Biol ; 32(3): 263-276, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-36582185

RESUMO

Lufenuron (LUF) and Methoxyfenozide (MET) as Insect Growth Regulators (IGRs) contribute to the current control of the catastrophic crop pest, Spodoptera exigua (Lepidoptera, Noctuidae). Yet S. exigua has evolved resistance to LUF and MET, which is possibly mediated by cytochrome P450 monooxygenases (P450s), particularly from the CYP3 clade family, as it plays a key role in the detoxification of insecticides. However, a mixture of LUF and MET (MML) (optimal ratio: 6:4) remains highly insecticidal. Here, we analysed the response of S. exigua to sublethal concentrations of LUF, MET, and MML via transcriptomics. Twelve differentially expressed genes (DEGs) encoding CYP3 clade members were observed in transcriptomes and CYP9A9 was significantly upregulated after treatment with LUF, MET, and MML. Further, CYP9A9 was most highly expressed in the midgut of L4 S. exigua larvae. RNAi-mediated knockdown of CYP9A9 reduced the activity of CYP450 and increased the susceptibility of S. exigua larvae to LUF, MET, and MML. Thus, CYP9A9 plays a key role in the detoxification of LUF, MET, and MML in S. exigua. These findings provide new insights into insecticidal actions of IGRs, which can be applied to the establishment of novel pest management strategies.


Assuntos
Inseticidas , Animais , Spodoptera/genética , Inseticidas/farmacologia , Hormônios Juvenis/farmacologia , Larva/genética , Sistema Enzimático do Citocromo P-450/genética
4.
FASEB J ; 36(6): e22340, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35524736

RESUMO

The prevention role of Lactiplantibacillus plantarum against the formation of kidney stones has been increasingly recognized; its mechanism, however, has mainly been focused on inhibiting the inflammation in the colon in the gastrointestinal (GI) system, and the intestinal metabolites from microflora have not been revealed fully with regarding to the stone formation. In this study, we investigated the effect of L. plantarum J-15 on kidney stone formation in renal calcium oxalate (CaOx) rats induced by ethylene glycol and monitored the changes of intestinal microflora and their metabolites detected by 16S rRNA sequencing and widely targeted analysis, followed by the evaluation of the intestinal barrier function and inflammation levels in the colon, blood and kidney. The results showed that L. plantarum J-15 effectively reduced renal crystallization and urinary oxalic acid. Ten microbial genera, including anti-inflammatory and SCFAs-related Faecalibaculum, were enriched in the J-15 treatment group. There are 136 metabolites from 11 categories significantly different in the J-15 supplementation group compared with CaOx model rats, most of which were enriched in the amino acid metabolic and secondary bile acid pathways. The expression of intestinal tight junction protein Occludin and the concentration of pro-inflammatory cytokines and prostaglandin were decreased in the intestine, which further reduced the translocated lipopolysaccharide and inflammation levels in the blood upon J-15 treatment. Thus, the inflammation and injury in the kidney might be alleviated by downregulating TLR4/NF-κB/COX-2 signaling pathway. It suggested that L. plantarum J-15 might reduce kidney stone formation by restoring intestinal microflora and metabolic disorder, protecting intestinal barrier function, and alleviating inflammation. This finding provides new insights into the therapies for renal stones.


Assuntos
Microbioma Gastrointestinal , Cálculos Renais , Animais , Oxalato de Cálcio/metabolismo , Feminino , Humanos , Inflamação/metabolismo , Cálculos Renais/induzido quimicamente , Cálculos Renais/prevenção & controle , Lactobacillaceae/genética , Lactobacillaceae/metabolismo , Masculino , RNA Ribossômico 16S/genética , Ratos
5.
Analyst ; 148(13): 3028-3035, 2023 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-37265383

RESUMO

Low back pain (LBP) seriously endangers human health and quality of life, and the detection of thoracolumbar fasciitis (TLF) is vital for the prevention and treatment of LBP. Surface-enhanced Raman scattering (SERS) is considered as a powerful technique for fingerprint detection due to the inherent richness of the spectral data. In this work, a novel SERS strategy based on a three-dimensional substrate was developed for fingerprint analysis for early diagnosis of TLF. A rat TLF model was established and the model was evaluated from the immunological and behavioral perspectives. Vibrational fingerprints were obtained by SERS testing of isolated fascial tissue and were used to explore the material changes during fasciitis. SERS spectra were analyzed using principal component analysis (PCA) that allowed unambiguous distinction and monitoring of component changes during TLF. Furthermore, in order to further clarify the occurrence and development of TLF, we combined clinical samples for analysis, and investigated the inflammatory factor expression levels of CRP and SAA in TLF. Our results demonstrated that tryptophan, phenylalanine and glycogen could unambiguously distinguish TLF as confirmed by SERS analysis, a method that is capable of noninvasive characterization of and diagnosis of TLF during LBP. We have provided a new tool that may promote in-depth study of the mechanism and treatment of fasciitis.


Assuntos
Dor Lombar , Análise Espectral Raman/métodos , Dor Lombar/diagnóstico , Masculino , Animais , Ratos
6.
Mol Biol Rep ; 50(11): 9637-9647, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37819499

RESUMO

Type 2 diabetes mellitus (T2DM) is a complex metabolic disease characterized by hyperglycaemia. T2DM is a highly heterogeneous polygenic disease. Due to genetic variation, variations in lifestyle and other environmental exposures, there are certain variations in the phenotype of T2DM patients. Sodium glucose cotransporter 2 (SGLT2) inhibitors are novel hypoglycaemic agents that increase urinary glucose excretion by inhibiting glucose reabsorption in the proximal tubules of the kidney. For glucagon-like peptide-1 receptor agonists and dipeptidyl peptidase-4 inhibitors, studies have confirmed a variety of gene variants that may modify their effects. For SGLT2 inhibitors, research has focused on the SLC5A2 gene encoding SGLT2 and UGT1A9 gene polymorphisms affecting SGLT2 inhibitor metabolism. The SLC5A2 polymorphism rs9934336 have been associated with decreased HbA1c during the oral glucose tolerance test. Common variants of the SLC5A2 gene are related to blood glucose and insulin concentrations, but not glucagon concentrations. SLC5A2 rs9934336 and rs3116150 are related to a lower risk of heart failure. SGLT2 inhibitor exposure of UGT1A9*3 carriers is commonly higher than that of noncarriers, while these effects commonly have no obvious clinical significance on SGLT2 inhibitor pharmacokinetics. In terms of efficacy, general SLC5A2 variants show no significant effect on the response to the SGLT2 inhibitor empagliflozin. At present, research on the relationship between genetic polymorphisms and the efficacy of SGLT2 inhibitors is limited. The main purpose of this review is to elucidate the general effects of SGLT2 polymorphisms and the association between polymorphisms and the treatment response to SGLT2 inhibitors.


Assuntos
Diabetes Mellitus Tipo 2 , Inibidores do Transportador 2 de Sódio-Glicose , Humanos , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/genética , Inibidores do Transportador 2 de Sódio-Glicose/uso terapêutico , Transportador 2 de Glucose-Sódio/genética , Hipoglicemiantes/farmacologia , Hipoglicemiantes/uso terapêutico , Glicemia/metabolismo , Glucose , Polimorfismo Genético/genética
7.
Mol Divers ; 2023 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-36787084

RESUMO

To discover new succinate dehydrogenase inhibitors (SDHI) fungicides, a series of amide derivatives containing a pyrrolidine moiety were designed and synthesized, and their antifungal activities were evaluated against Monilinia fructicola (M. fructicola), Rhizoctonia solani (R. solani), Fusarium graminearum schw (F. graminearum), Fusarium oxysporum (F. oxysporum), and Phytophthora infestans (P. infestans). Some compounds showed excellent antifungal activities against the five fungi. Among them, compound 6 showed broad-spectrum inhibitory activities. The EC50 of compound 6 against M. fructicola, R. solani, F. graminearum, F. oxysporum, and P. infestans were 2.13, 14.42, 1.69, 27.79, and 27.12 mg/L, respectively. In addition, compound 6 can effectively inhibit the spore germination of M. fructicola and has moderate damage to the cell membrane. Compound 6 can effectively inhibit succinate dehydrogenase (SDH) of M. fructicola, and can significantly increase the expression levels of SDHC and SDHD. Compound 6 can be used as a lead structure for developing new SDH inhibitors.

8.
Gynecol Obstet Invest ; 88(4): 197-213, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36934719

RESUMO

OBJECTIVE: The objective of this study was to explore the inhibitory effect of total flavonoids of Polygala fallax Hemsl (PFHF) on human ectopic endometrial stromal cells (HEcESCs) and its mechanism. DESIGN: The apoptosis, cell cycle, migration, and invasion ability of HEcESCs (Fresh human ovarian endometriosis tissue was used for primary culture) after PFHF treatment were detected, and the mechanism of action was explored. MATERIALS: The Polygala fallax Hemsl (PFH), RPMI 1640 culture medium, Dulbecco's modified Eagle's medium (DMEM)/F-12, fetal bovine serum, penicillin/streptomycin, cell counting kit-8 (CCK-8) kit, trypsin, phenylmethylsulfonyl fluoride, radioimmunoprecipitation assay tissue/cell lysate, bicinchoninic acid protein concentration detection kits, protein loading buffer, the apoptosis and cell cycle extraction kits, the matrix glue, TRIzol Universal Reagent, the reverse transcription kit, AB HS Green qPCR Mix, the ECL chromogenic solution, enzyme labeling instrument, flow cytometry, automatic real-time fluorescence quantitative PCR instrument, Goat anti-rabbit, rabbit anti-ß-actin, vimentin, phosphatidylinositol 3 kinase (PI3K), protein kinase B (AKT), B-cell lymphoma-2 (Bcl-2), Bcl-extra long (Bcl-xl), Bcl-2 associated death promoter (Bad) antibody, Alexa Fluor 594-labeled secondary antibody, the inverted microscope, the constant temperature carbon dioxide cell incubator. SETTING: Five parts included introduction, materials and methods, results, discussion, and conclusion. METHODS: The potential targets and pathways of PFHF in the treatment of endometriosis were predicted by network pharmacology. The effect of PFHF on the proliferation, apoptosis and cell cycle, migration, and invasion of HEcESCs was detected by CCK-8 method, flow cytometry, and Transwell chamber experiment. Label-free quantitative proteomics based on mass spectrometry was used to analyze the protein mass spectrum of differential expression of HEcESCs before and after PFHF, and the biological information was analyzed. The effects of PFHF on the mRNA and protein expression of pathway-related genes predicted in HEcESCs were detected by reverse transcription-quantitative polymerase chain reaction and Western blotting. RESULTS: The network pharmacology predicts that PFHF treats endometriosis through PI3K/AKT signaling pathway. Compared with control group (DMEM/F-12 medium alone), the high dose PFHF can significantly reduce the viability, migration, and invasion of HEcESCs, increase the apoptosis rate of HEcESCs, and make the HEcESCs accumulated in G0/G1 phase in a time- and dose-dependent manner (p < 0.05). The analysis of label-free quantitative proteomics indicated that PFHF flavonoids may induce apoptosis of EESCs through PI3K/AKT signaling pathway. The results of RT-qPCR and Western blotting showed that the expressions of PI3K, AKT, Bcl-2, and Bcl-xl were significantly downregulated, while the bad expression was upregulated in HEcESCs treated with PFHF (p < 0.05). LIMITATIONS: This research investigated the effects of PFHF on the stromal endometriotic cells only. So it is unknown how PFHF can affect the entire endometriotic lesion. And the research is carried out in vitro, which gives no impression about the bioavailability of the flavonoids. CONCLUSION: PFHF reduces the expression of PI3K, AKT, Bcl-2, and Bcl-xl through the PI3K/AKT/Bcl-2 signaling pathway to inhibit HEcESCs proliferation, migration, and invasion and promote their apoptosis.


Assuntos
Endometriose , Polygala , Feminino , Animais , Humanos , Coelhos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Fosfatidilinositol 3-Quinase/metabolismo , Fosfatidilinositol 3-Quinase/farmacologia , Fosfatidilinositol 3-Quinases/metabolismo , Polygala/metabolismo , Flavonoides/farmacologia , Endometriose/tratamento farmacológico , Transdução de Sinais , Apoptose , Células Estromais/metabolismo , Proliferação de Células
9.
Pestic Biochem Physiol ; 189: 105310, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36549817

RESUMO

With the aim of discovering novel nematicidal scaffolds, the nematicidal activities of a series of quinazoline compounds were tested, with some compounds showing excellent results. Among them, the LC50 values of compound K11 against Bursaphelenchus xylophilus, Aphelenchoides besseyi, and Ditylenchus destructor were 7.33, 6.09, and 10.95 mg/L, respectively. In addition, the nematicidal activity of compound K11 against Meloidogyne incognita was 98.77% at 100 mg/L. Compound K11 not only increased the production of reactive oxygen species and the accumulation of lipofuscin and lipids in nematodes, but it also attenuated nematode pathogenicity by reducing the nematodes' antioxidant capacity. Transcriptomic analysis showed that compound K11 had significant effects on fatty acid degradation, metabolic pathways, and the differentially expressed genes related to redox processes in nematodes. Furthermore, the expression levels of the corresponding differentially expressed genes were verified using real-time quantitative polymerase chain reaction. Quinazoline can be used as a new nematicidal scaffold, and it is expected that more work will be done on the discovery of novel nematicides based on the lead compound K11 in the future.


Assuntos
Tylenchida , Tylenchoidea , Animais , Antinematódeos/farmacologia , Dose Letal Mediana , Espécies Reativas de Oxigênio
10.
Pestic Biochem Physiol ; 193: 105457, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37248023

RESUMO

Rice bacterial diseases seriously threaten the development of rice industry in the world, and chemical control is still one of the effective means to control it. To find novel antibacterial agents, 42 resveratrol derivatives were designed and synthesized based on natural product resveratrol as lead structure, and their antibacterial activities were evaluated. Most compounds have excellent antibacterial activities. Among them, the EC50 values of compound B1 against Xanthomonas oryzae pv. oryzae (Xoo) and Xanthomonas oryzae pv. oryzicola (Xoc) were 4.76 and 8.85 mg/L, respectively. The curative activities of compound B1 against bacterial leaf blight and bacterial leaf streak were 45.57 and 38.40%, and the protective activities were 49.41 and 35.93%, respectively. In addition, compound B1 could change bacterial cell surface morphology by inhibiting biofilm formation and exopolysaccharide production, and increasing membrane permeability, thereby affecting the normal growth of bacteria. Furthermore, transcriptome analysis showed that differential expressed genes were mainly enriched in plant-pathogen interaction pathway and MAPK signaling pathway-plant after compound B1 treated susceptible rice. We will further optimize the structure of compound B1 in future work to find more efficient antibacterial agents.


Assuntos
Oryza , Xanthomonas , Resveratrol/farmacologia , Testes de Sensibilidade Microbiana , Doenças das Plantas/prevenção & controle , Doenças das Plantas/microbiologia , Antibacterianos/química , Oryza/microbiologia
11.
Int J Mol Sci ; 24(13)2023 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-37445692

RESUMO

Citrus Huanglongbing (HLB) is one of the most destructive diseases in the citrus industry. At present, Candidatus Liberibacter asiaticus (CLas) cannot be cultured in vitro, and there is a lack of rapid methods to test antibacterial activity, which greatly hinders the discovery of new antibacterial agents against HLB. To establish a rapid screening method for antibacterial agents against HLB with simple operation, a short cycle, and a large number of tests, the CLas contents in leaves from different citrus branches, different leaves from the same citrus branch, and two halves of the same citrus leaf were detected. Compared with the leaves on different branches and different leaves on the same branch, the difference in CLas content of the left and right halves of the same leaf was small; the difference was basically between 0.7 and 1.3. A rapid and efficient method for primary screening agents against HLB termed the "half-leaf method" was established through our long-term optimization and improvement. To verify the stability and reliability of the activity data measured using this method, 6-chloropurine riboside, which is highly soluble in water, was used as the test agent, and its antibacterial activity against HLB was tested 45 times. The results of the antibacterial activity test showed little difference in the mean values of each data group, indicating that this method could be used as a rapid method for screening agents against HLB. We used this method to test the antibacterial activity of compounds synthesized by our research group against HLB and found that some of the compounds showed good activity.


Assuntos
Citrus , Rhizobiaceae , Citrus/microbiologia , Reprodutibilidade dos Testes , Doenças das Plantas/microbiologia , Antibacterianos/farmacologia
12.
Int J Mol Sci ; 24(13)2023 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-37445983

RESUMO

Benzoxazole and benzothiazole have a broad spectrum of agricultural biological activities, such as antibacterial, antiviral, and herbicidal activities, which are important fused heterocyclic scaffold structures in agrochemical discovery. In recent years, great progress has been made in the research of benzoxazoles and benzothiazoles, especially in the development of herbicides and insecticides. With the widespread use of benzoxazoles and benzothiazoles, there may be more new products containing benzoxazoles and benzothiazoles in the future. We systematically reviewed the application of benzoxazoles and benzothiazoles in discovering new agrochemicals in the past two decades and summarized the antibacterial, fungicidal, antiviral, herbicidal, and insecticidal activities of the active compounds. We also discussed the structural-activity relationship and mechanism of the active compounds. This work aims to provide inspiration and ideas for the discovery of new agrochemicals based on benzoxazole and benzothiazole.


Assuntos
Agroquímicos , Benzoxazóis , Benzoxazóis/farmacologia , Benzoxazóis/química , Benzotiazóis/química , Antibacterianos , Relação Estrutura-Atividade
13.
Appl Environ Microbiol ; 88(21): e0058722, 2022 11 08.
Artigo em Inglês | MEDLINE | ID: mdl-36255244

RESUMO

The molecular mechanism of the Ca2+-mediated formation of competent cells in Escherichia coli remains unclear. In this study, transcriptome and proteomics techniques were used to screen genes in response to Ca2+ treatment. A total of 333 differentially expressed genes (317 upregulated and 16 downregulated) and 145 differentially expressed proteins (54 upregulated and 91 downregulated) were obtained. These genes and proteins are mainly enriched in cell membrane components, transmembrane transport, and stress response-related functional terms. Fifteen genes with these functions, including yiaW, ygiZ, and osmB, are speculated to play a key role in the cellular response to Ca2+. Three single-gene deletion strains were constructed with the Red homologous recombination method to verify its function in genetic transformation. The transformation efficiencies of yiaW, ygiZ, and osmB deletion strains for different-size plasmids were significantly increased. None of the three gene deletion strains changed in size, which is one of the main elements of microscopic morphology, but they exhibited different membrane permeabilities and transformation efficiencies. This study demonstrates that Ca2+-mediated competence formation in E. coli is not a simple physicochemical process and may involve the regulation of genes in response to Ca2+. This study lays the foundation for further in-depth analyses of the molecular mechanism of Ca2+-mediated transformation. IMPORTANCE Using transcriptome and proteome techniques and association analysis, we identified several key genes involved in the formation of Ca2+-mediated E. coli DH5α competent cells. We used Red homologous recombination technology to construct three single-gene deletion strains and found that the transformation efficiencies of yiaW, ygiZ, and osmB deletion strains for different-size plasmids were significantly increased. These results proved that the genetic transformation process is not only a physicochemical process but also a reaction process involving multiple genes. These results suggest ways to improve the horizontal gene transfer mechanism of foodborne microorganisms and provide new ideas for ensuring the safety of food preservation and processing.


Assuntos
Escherichia coli , Transferência Genética Horizontal , Escherichia coli/genética , Técnicas de Inativação de Genes , Plasmídeos , Transformação Genética
14.
Opt Express ; 30(18): 32347-32354, 2022 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-36242298

RESUMO

The evolution of multiphoton microscopy is critically dependent on the development of ultrafast laser technologies. The ultrashort pulse laser source at 1.7 µm waveband is attractive for in-depth three-photon imaging owing to the reduced scattering and absorption effects in biological tissues. Herein, we report on a 1.7 µm passively mode-locked figure-9 Tm-doped fiber laser. The nonreciprocal phase shifter that consists of two quarter-wave plates and a Faraday rotator introduces phase bias between the counter-propagating beams in the nonlinear amplifying loop mirror. The cavity dispersion is compensated to be slightly positive, enabling the proposed 1.7 µm ultrafast fiber laser to deliver the dissipative soliton with a 3-dB bandwidth of 20 nm. Moreover, the mode-locked spectral bandwidth could be flexibly tuned with different phase biases by rotating the wave plates. The demonstration of figure-9 Tm-doped ultrafast fiber laser would pave the way to develop the robust 1.7 µm ultrashort pulse laser sources, which could find important application for three-photon deep-tissue imaging.

15.
Opt Lett ; 47(7): 1750-1753, 2022 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-35363726

RESUMO

We numerically investigate the pulsating dynamics of pure-quartic solitons (PQSs) in a passively mode-locked fiber laser. The bifurcation diagrams show that the PQS can alternate between the stable single soliton and pulsating regimes multiple times before transiting into the chaotic state. This multi-alternation behavior can be attributed to energy redistribution across the central part and the oscillating tails of the PQS, which is caused by an imperfect counterbalance between self-phase modulation (SPM)-induced and fourth-order dispersion (FOD)-induced phase shifts. Soliton creeping behavior can be observed during the pulsating process, accompanied by periodic asymmetric temporal profiles and central wavelength shifts of the PQS. These findings give new insights into the dynamics of PQSs in fiber lasers.

16.
Pestic Biochem Physiol ; 184: 105122, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35715060

RESUMO

The discovery of new scaffolds and targets for pesticides is still a huge challenge facing the sustainable development of modern agriculture. In recent years, quinazoline derivatives have achieved great progress in drug discovery and have attracted great attention. Quinazoline is a unique bicyclic scaffold with a variety of biological activities, which increases the possibilities and flexibility of structural modification, showing enormous appeal in the discovery of new pesticides. Therefore, the agricultural biological activities, structure-activity relationships (SAR), and mechanism of action of quinazoline derivatives in the past decade were reviewed systematically, with emphasis on SAR and mechanism. Then, we prospected the application of the quinazoline scaffold as a special structure in agricultural chemical discovery, hoping to provide new ideas for the rational design and mechanism of novel quinazoline agricultural chemicals in the future.


Assuntos
Praguicidas , Quinazolinas , Agroquímicos/farmacologia , Praguicidas/farmacologia , Quinazolinas/química , Quinazolinas/farmacologia , Relação Estrutura-Atividade
17.
Pestic Biochem Physiol ; 186: 105178, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35973767

RESUMO

Spodoptera exigua (Lepidoptera, Noctuidae) has been responsible for causing considerable and widespread agricultural losses worldwide. Owing to strong selective pressure, S. exigua showed increased resistance to Lufenuron (LUF). Consequently, RNA interference (RNAi)-based insecticides had more benefits than chemical insecticides. Therefore, to enhance the insecticidal activity of LUF to S. exigua, in the present study, we aimed to elucidate the impact of double-stranded RNAs (dsRNAs) on S. exigua larval susceptibility to LUF. First, the transcriptome of S. exigua was sequenced following the treatment with LUF. By comparing the upregulated and downregulated GO enrichment, chitin binding and chitin metabolic processes were the significantly enriched pathways. According to transcriptome sequencing, 8 genes associated with chitin biosynthesis, 8 chitin degradation genes, and 17 cuticle protein genes were obtained. UDP-N-acetylglucosamine pyrophosphorylase (UAP) and Chitin synthase A (CHSA) showed significantly downregulated expression after treatment with different sublethal doses of LUF. Downregulation of UAP increased mortality from 31.97% to 47.91% when the larvae were exposed to LUF. A significant increase in the mortality of S. exigua from 30.63% to 50.19% was observed following LUF administration after dsCHSA. In addition, the expression analysis of genes associated with chitin biosynthesis was significantly changed after LUF treatment, dsRNAs-RNAi, and their combination (LUF-dsRNAs). Significant differences were observed in the chitin content between the control group at 72 h after treatments. Results of the present study can help further elucidate the understanding of the combined effects of RNAi and LUF on S. exigua. Additionally, this research provides a suitable foundation for future studies with the aim to develop an efficient method of delivery for large-scale pest control in the fields.


Assuntos
Quitina Sintase , Inseticidas , Animais , Benzamidas , Quitina/farmacologia , Quitina Sintase/genética , Quitina Sintase/metabolismo , Fluorocarbonos , Inseticidas/metabolismo , Inseticidas/farmacologia , Larva/genética , Larva/metabolismo , Nucleotidiltransferases , RNA de Cadeia Dupla/farmacologia , Spodoptera
18.
Physiol Mol Biol Plants ; 28(7): 1421-1435, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36051231

RESUMO

Three species of Gentiana (Gentiana manshurica kitag., Gentiana scabra bunge., and Gentiana triflora pall.) were the main source for an important traditional Chinese medicine, "Longdan", which was first mentioned in " Shennong materia medica Sutra " 2000 years ago. Until recently, there were very few reports on taxonomic classification of these three traditional medicinal Gentiana species. In the current study, chloroplast genomes of the three Gentiana species were sequenced and the phylogenetic analyses were performed in combination with 31 NCBI downloaded Gentiana species sequences and two species of Swertia as outgroup. Based on the phylogenetic results, a new taxonomic classification for Gentiana was proposed, including 4 independent clades with 6 subdivisions (Group 1-Group 6). All the general features, SSR characteristics and gene composition of Gentiana chloroplast genomes strongly supported such a new classification system for Gentiana, which could lay a theoretical foundation for Gentiana in the molecular evolutionary research. Finally, phylogenetic analyisis also demonstrated that the three examined species from Gentiana could cluster together into one group (Group 6), which was far away from the evolutionary position of the medicinal species, Gentiana rigescens Franch, which was consistent with the traditional classification in traditional medicinal uses and taxonomy. Supplementary Information: The online version contains supplementary material available at 10.1007/s12298-022-01217-0.

19.
Opt Lett ; 46(23): 5922-5925, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34851924

RESUMO

We report on a 1.7 µm Tm-fiber chirped pulse amplification (CPA) system by virtue of a broadband dissipative soliton seed laser. The seed oscillator delivers the dissipative soliton with 10 dB spectral bandwidth of 23 nm and an average power of 4 mW. The duration of the seed pulse is directly stretched to ∼60ps by a segment of 50 m normal dispersion fiber. Using a two-stage fiber amplifier, the average power of the pulse is amplified to 1.95 W with a slope efficiency of 40.3%. The amplified pulse is then compressed to 348 fs by a pair of fused silica transmission gratings. The compressed average power of 1.3 W and peak power of 155 kW are achieved. These experimental results would pave the way to achieve a high-power femtosecond laser source at 1.7 µm, which could find important applications in fields such as three-photon deep-tissue imaging and material processing.

20.
Opt Lett ; 46(19): 4848-4851, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34598215

RESUMO

The bidirectional ultrafast fiber laser is a promising light source for dual-comb applications. The counter-propagating geometry could lead to soliton interaction through gain sharing, as well as the possible outcome of polarization instability. However, the polarization dynamics hidden behind the soliton interaction process in bidirectional fiber lasers were rarely investigated. Herein, we report on the polarization instability induced by the mutual soliton interactions through fiber gain in a bidirectional mode-locked fiber laser. Depending on the adjustment of the intracavity birefringence, the polarization states of two counter-propagating solitons can exhibit similar periodical polarization switching behaviors with a polarization-rotating transition state. The successive interactions of the bidirectional solitons mediated by the polarization cross-saturation effect of gain fiber could be responsible for the soliton polarization instability. These findings, in addition to the fundamental interest of the soliton nonlinear dynamics in dissipative optical systems, also open up new possibilities for creating dynamical control of the soliton polarization state and performance improvement in bidirectional ultrafast fiber lasers.

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