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1.
PLoS One ; 19(6): e0302939, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38843237

RESUMO

OBJECTIVE: To explore the relationship among nap time, night sleep time, and depression among the elderly and to determine the recommended sleep time to provide a scientific and reasonable basis for the prevention and control of depression in residents. METHODS: Based on the 2020 China Health and Elderly Care Longitudinal Survey (CHARLS) database, the demographic data and the health and lifestyle information of the study subjects were obtained. A total of 2,959 valid samples were included, and the relationship between sleep and depression was explored by logistic regression, restricted cubic spline, and isotemporal substitution model. RESULTS: In the cross-sectional analysis, no statistical relationship was observed between napping time and depression in the elderly. The optimal sleep interval for the elderly at night is 6-7.5 hours, and the health benefits are the largest. A sleep duration of < 6 hours at night (OR = 2.25, 95% CI: 1.90 to 2.65) was associated with a high likelihood of depression. The probability of depression in the elderly continues to decrease with the increase of time after the nighttime sleep duration reaches 6 hours and is at the lowest level of about 7.5 hours. Moreover, the probability of depression will increase after the sleep duration exceeds 9.5 hours. In the range of 6-7.5 hours of recommended sleep duration, the likelihood of depression in the elderly will be reduced by 0.311 for every 30-minute increase in nighttime sleep time instead of noon sleep time. CONCLUSION: The duration of nighttime sleep and the probability of depression have a U-shaped relationship. The likelihood of depression was lowest in the elderly who slept for 6-8 hours at night, and the likelihood of depression could be reduced by increasing the nighttime sleep time instead of napping time within the optimal nighttime sleep range.


Assuntos
Depressão , Sono , Humanos , Masculino , Depressão/epidemiologia , Estudos Transversais , Feminino , Idoso , Sono/fisiologia , China/epidemiologia , Fatores de Tempo , Idoso de 80 Anos ou mais , Pessoa de Meia-Idade , População do Leste Asiático
2.
Sci Data ; 11(1): 519, 2024 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-38778070

RESUMO

Endosymbionts regulate the behavior of pest species, which could provide insights into their control. The citrus leafminer (Phyllocnistis citrella Stainton) is a widely distributed pest associated with diseases of citrus, especially of young trees. Here, we determined the endosymbiont composition of P. citrella in citrus orchards across China. The resulting dataset comprised average 50,430 high-quality reads for bacterial 16S rRNA V3-V4 regions of endosymbionts from 36 P. citrella larvae sampled from 12 citrus orchards across China. The sequencing depth and sampling size of this dataset were sufficient to reveal most of the endosymbionts of P. citrella. In total, 2,875 bacterial amplicon sequence variants were obtained; taxonomic analysis revealed a total of 372 bacterial genera, most of which were Proteobacteria phylum with Undibacterium being the most abundant genus. This dataset provides the first evidence of P. citrella endosymbionts that could support the development of pest management approaches in citrus orchards.


Assuntos
Bactérias , Citrus , Mariposas , Simbiose , Animais , Bactérias/classificação , Bactérias/genética , China , Larva/microbiologia , Mariposas/microbiologia , RNA Ribossômico 16S/genética
3.
Int J Biol Macromol ; 265(Pt 2): 130824, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38492708

RESUMO

Polysaccharide-functionalized gold nanoparticles (Polysaccharide-Au NPs) with high stability were successfully prepared by a straightforward method. Notably, the Au (III) ion acts as a strong Lewis acid to facilitate glycosidic bond breaking. Subsequently, the polysaccharide conformation was transformed to an open-chain form, exposing highly reduced aldehyde or ketone groups that reduce Au (III) to Au (0) crystal species, further growing into Au NPs. As-prepared Au NPs displayed excellent stability over a longer storage period (more than 70 days), a wide range of temperatures (25-60 °C), and pH range (3-11), varying concentrations (0-200 mM) and types of salt ions (Na+, K+, Ca2+, Mg2+), and glutathione solutions (5 mM). More interestingly, polysaccharide-Au NPs retained the antioxidant activity of polysaccharides and reduced oxidative damage at the cellular level through decreased reactive oxygen species (ROS) production. The intracellular levels of ROS pretreated with polysaccharide and polysaccharide-Au NPs were decreased 53.12-75.85 % compared to the H2O2 group, respectively. Therefore, the green synthesized Au NPs from natural active polysaccharides exhibit potential applications in biomedical fields.


Assuntos
Antioxidantes , Nanopartículas Metálicas , Antioxidantes/farmacologia , Espécies Reativas de Oxigênio , Peróxido de Hidrogênio , Ouro/química , Nanopartículas Metálicas/química , Polissacarídeos/farmacologia
4.
J Agric Food Chem ; 72(13): 7010-7020, 2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38529524

RESUMO

Cyetpyrafen is a recently developed acaricide. The citrus red mite, Panonychus citri (McGregor), has developed significant resistance to cyetpyrafen. However, the molecular mechanism underlying the cyetpyrafen resistance in P. citri remains unclear. Glutathione S-transferases (GSTs) play a critical role in arthropod pesticide resistance. This study showed that GSTs were potentially related to the resistance of P. citri to cyetpyrafen through synergistic experiments and enzyme activity analysis. An omega-family GST gene, PcGSTO1, was significantly up-regulated in the egg, nymph, and adult stages of the cyetpyrafen-resistant strain. Additionally, silencing of PcGSTO1 significantly increased the mortality of P. citri to cyetpyrafen and recombinant PcGSTO1 demonstrated the ability to metabolize cyetpyrafen. Our results indicated that the overexpression of PcGSTO1 is associated with cyetpyrafen resistance in P. citri, and they also provided valuable information for managing resistance in P. citri.


Assuntos
Acaricidas , Tetranychidae , Animais , Glutationa Transferase/genética , Glutationa Transferase/metabolismo , Tetranychidae/genética , Tetranychidae/metabolismo , Acaricidas/farmacologia , Acaricidas/metabolismo
5.
Insect Sci ; 31(1): 13-27, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37231527

RESUMO

Diaphorina citri is a global citrus pest. As a vector insect, it can transmit the causative agents of citrus huanglongbing, causing irreversible losses to the citrus industry. The acquisition of genomic information can provide a molecular genetic basis for effective control of D. citri. Here, the DNBSEQ™ , Oxford Nanopore Technologies, and Hi-C technologies are applied to generate a high-quality chromosome-level genome of D. citri. The genome size of D. citri was 523.78 Mb with a scaffold N50 of 47.05 Mb distributed on 13 chromosomes. A total of 250.64 Mb (47.85%) repeat sequences and 24 048 protein-coding genes were predicted. Genome resequencing of female and male individuals indicated that the sex chromosome system of D. citri is XO. Phylogenetic analysis demonstrated that D. citri and Pachypsylla venusta, which separated from their most recent common ancestor about 336.62 million years ago, were the most closely related. Additionally, we identified genes potentially involved in detoxification metabolism, pathogen transmission, and honeydew secretion for further investigation. The high-quality genome provides an important reference for developing effective management strategies of D. citri.


Assuntos
Citrus , Hemípteros , Humanos , Animais , Feminino , Masculino , Hemípteros/genética , Filogenia , Análise de Sequência de DNA , Cromossomos , Citrus/genética
6.
Carbohydr Polym ; 321: 121284, 2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-37739497

RESUMO

Polysaccharide-based gold nanomaterials have attracted great interest in biomedical fields such as cancer therapy and immunomodulation due to their prolonged residence time in vivo and enhanced immune response. This review aims to provide an up-to-date and comprehensive summary of polysaccharide-based Au NMs synthesis, including mechanisms, polysaccharide structure-effects, and anticancer activity. Firstly, research progress on the synthesis mechanism of polysaccharide-based Au NMs was addressed, which included three types based on the variety of polysaccharides and reaction environment: breaking of glycosidic bonds via Au (III) or base-mediated production of highly reduced intermediates, reduction of free hydroxyl groups in polysaccharide molecules, and reduction of free amino groups in polysaccharide molecules. Then, the potential effects of polysaccharide structure characteristics (molecular weight, composition of monosaccharides, functional groups, glycosidic bonds, and chain conformation) and reaction conditions (the reaction temperature, reaction time, pH, concentration of gold precursor and polysaccharides) on the size and shape of Au NMs were explored. Finally, the current status of polysaccharide-based Au NMs cancer therapy was summarized before reaching our conclusions and perspectives.


Assuntos
Glicosídeos , Neoplasias , Humanos , Ouro/farmacologia , Imunomodulação , Polissacarídeos/farmacologia , Neoplasias/tratamento farmacológico
7.
Sci Data ; 10(1): 478, 2023 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-37479750

RESUMO

Asian citrus psyllid (Diaphorina citri, D. citri) is the important vector of "Candidatus Liberibacter asiaticus" (CLas), associated with Huanglongbing, the most devastating citrus disease worldwide. CLas can affect endosymbiont abundance of D. citri. Here, we generated the high-quality gut endosymbiont metagenomes of Diaphorina citri on the condition of CLas infected and uninfected. The dataset comprised 6616.74 M and 6586.04 M raw reads, on overage, from CLas uninfected and infected psyllid strains, respectively. Taxonomic analysis revealed that a total of 1046 species were annotated with 10 Archaea, 733 Bacteria, 234 Eukaryota, and 69 Viruses. 80 unique genera in CLas infected D. citri were identified. DIAMOND software was used for complement function research against various functional databases, including Nr, KEGG, eggNOG, and CAZy, which annotated 84543 protein-coding genes. These datasets provided an avenue for further study of the interaction mechanism between CLas and D. citri.


Assuntos
Hemípteros , Rhizobiaceae , Animais , Hemípteros/genética , Hemípteros/microbiologia , Metagenoma , Rhizobiaceae/genética
8.
Front Plant Sci ; 14: 1129508, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37313258

RESUMO

Huanglongbing (HLB), the most prevalent citrus disease worldwide, is responsible for substantial yield and economic losses. Phytobiomes, which have critical effects on plant health, are associated with HLB outcomes. The development of a refined model for predicting HLB outbreaks based on phytobiome markers may facilitate early disease detection, thus enabling growers to minimize damages. Although some investigations have focused on differences in the phytobiomes of HLB-infected citrus plants and healthy ones, individual studies are inappropriate for generating common biomarkers useful for detecting HLB on a global scale. In this study, we therefore obtained bacterial information from several independent datasets representing hundreds of citrus samples from six continents and used these data to construct HLB prediction models based on 10 machine learning algorithms. We detected clear differences in the phyllosphere and rhizosphere microbiomes of HLB-infected and healthy citrus samples. Moreover, phytobiome alpha diversity indices were consistently higher for healthy samples. Furthermore, the contribution of stochastic processes to citrus rhizosphere and phyllosphere microbiome assemblies decreased in response to HLB. Comparison of all constructed models indicated that a random forest model based on 28 bacterial genera in the rhizosphere and a bagging model based on 17 bacterial species in the phyllosphere predicted the health status of citrus plants with almost 100% accuracy. Our results thus demonstrate that machine learning models and phytobiome biomarkers may be applied to evaluate the health status of citrus plants.

10.
Crit Rev Food Sci Nutr ; 63(28): 9330-9348, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-35452320

RESUMO

Nanozymes with excellent broad-spectrum antibacterial properties offers an alternative strategy for food preservation. This review comprehensively summarized the antibacterial mechanisms of nanozymes, including the generation of reactive oxygen species (ROS) and the destruction of biofilms. Besides, the primary factors (size, morphology, hybridization, light, etc.) regulating the antibacterial activity of different types of nanozymes were highlighted in detail, which provided effective guidance on how to design highly efficient antibacterial nanozymes. Moreover, this review presented elaborated viewpoints on the unique applications of nanozymes in food preservation, including the selection of nanozymes loading matrix, fabrication techniques of nanozymes-based antibacterial films/coatings, and the recent advances in the application of nanozymes-based antibacterial films/coatings in food preservation. In the end, the safety issues of nanozymes have also been mentioned. Overall, this review provided new avenues in the field of food preservation and displayed great prospects.


Assuntos
Nanoestruturas , Conservação de Alimentos , Antibacterianos/farmacologia , Espécies Reativas de Oxigênio
11.
Chemosphere ; 311(Pt 2): 137051, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36334733

RESUMO

Graphene quantum dots (GQDs), a novel broad-spectrum antibacterial agent, are considered potential candidates in the field of biomedical and food safety due to their outstanding antimicrobial properties and excellent biocompatibility. To uncover the molecular regulatory mechanisms underlying the phenotypes, the overall regulation of genes and metabolites in Escherichia coli (E. coli) after GQDs stimulation was investigated by RNA-sequencing and LC-MS. Gene transcription and metabolite expression related to a series of crucial biomolecular processes were influenced by the GQDs stimulation, including biofilm formation, bacterial secretion system, sulfur metabolism and nitrogen metabolism, etc. This study could provide profound insights into the GQDs stress response in E. coli, which would be useful for the development and application of GQDs in food safety.

12.
Insects ; 13(11)2022 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-36354837

RESUMO

Spirodiclofen is one of the most widely used acaricides in China. The citrus red mite, Panonychus citri (McGregor) (Acari: Tetranychidae), is one of the most destructive citrus pests worldwide and has developed a high resistance to spirodiclofen. However, the molecular mechanism of spirodiclofen resistance in P. citri is still unknown. In this study, we identified a field spirodiclofen-resistant strain (DL-SC) that showed 712-fold resistance to spirodiclofen by egg bioassay compared to the susceptible strain. Target-site resistance was not detected as non-synonymous mutations were not found by amplification and sequencing of the ACCase gene of resistant and susceptible strains; in addition, the mRNA expression levels of ACCase were similar in both resistant and susceptible strains. The activity of detoxifying enzymes P450s and CCEs in the resistant strain was significantly higher than in the susceptible strain. The transcriptome expression data showed 19 xenobiotic metabolisms genes that were upregulated. Stage-specific expression profiling revealed that the most prominent upregulated gene, CYP385C10, in transcriptome data was significantly higher in resistant strains in all stages. Furthermore, functional analysis by RNAi indicated that the mortality caused by spirodiclofen was significantly increased by silencing the P450 gene CYP385C10. The current results suggest that overexpression of the P450 gene, CYP385C10, may be involved in spirodiclofen resistance in P. citri.

13.
Biochem Biophys Res Commun ; 635: 291-298, 2022 12 20.
Artigo em Inglês | MEDLINE | ID: mdl-36327916

RESUMO

Colorectal cancer is one of the most common malignancies causing the majority of cancer-related deaths. There is an urgent need to develop new anticancer modalities. Recently, efforts have been made to turn clinically approved drugs into anticancer agents in specific tumor microenvironments via NPs. Disulfiram (DSF) as an effective copper (Cu2+)-dependent anti-tumour drug, which has been more widely used in antitumor research. Here, we constructed a novel therapeutic nanoplatforms, DSF@CuS, by encapsulating DSF in hollow CuS NPs to enable in situ chemoselective activation of DSF and hyperthermal amplified chemotherapy. The anticancer effect of DSF was enhanced by the thermal energy generated under NIR irradiation through the intrinsic photothermal conversion of CuS. As a result, significant apoptosis was induced in vitro, and tumor elimination was achieved in vivo. Collectively, DSF@CuS combined with photothermal therapy can significantly promote the apoptosis of CT26 colorectal cancer cells both in vitro and in vivo, providing a potential theoretical agent for the treatment of colorectal cancer.


Assuntos
Antineoplásicos , Neoplasias Colorretais , Nanopartículas , Humanos , Dissulfiram/farmacologia , Cobre/farmacologia , Linhagem Celular Tumoral , Nanopartículas/uso terapêutico , Sulfetos/farmacologia , Antineoplásicos/farmacologia , Neoplasias Colorretais/tratamento farmacológico , Microambiente Tumoral
14.
Int J Nanomedicine ; 17: 2647-2659, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35730051

RESUMO

Background: Natural bioactive substances have been widely studied for their superior anti-tumor activity and low toxicity. However, natural bioactive substances suffer from poor water-solubility and poor stability in the physiological environment. Therefore, to overcome the drawbacks of natural bioactive substances in tumor therapy, there is an urgent need for an ideal nanocarrier to achieve high bioactive substance loading with low toxicity. Materials and Methods: Face-centered cubic hollow mesoporous Prussian Blue (HMPB) NPs were prepared by stepwise hydrothermal method. Among them, PVP served as a protective agent and HCl served as an etching agent. Firstly, MPB NPs were obtained by 0.01 M HCl etching. Then, the highly uniform dispersed HMPB NPs were obtained by further etching with 1 M HCl. Results: In this work, we report a pH-responsive therapeutic nanoplatform based on HMPB NPs. Surprisingly, as-prepared HMPB NPs with ultra-high bioactive substances loading capacity of 329 µg mg-1 owing to the large surface area (131.67 m2 g-1) and wide internal pore size distribution (1.8-96.2 nm). Moreover, with the outstanding photothermal conversion efficiency of HMPB NPs (30.13%), natural bioactive substances were released in the tumor microenvironment (TME). HMPB@PC B2 achieved excellent synergistic therapeutic effects of photothermal therapy (PTT) and chemotherapy (CT) in vivo and in vitro without causing any extraneous side effects. Conclusion: A biocompatible HMPB@PC B2 nanoplatform was constructed by simple physical adsorption. The in vitro and in vivo experiment results demonstrated that the synergy of PTT/CT provided excellent therapeutic efficiency for cervical cancer without toxicity. Altogether, as-designed nanomedicines based on natural bioactive substances may be provide a promising strategy for cancer therapy.


Assuntos
Antineoplásicos , Nanopartículas , Neoplasias , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Linhagem Celular Tumoral , Humanos , Neoplasias/tratamento farmacológico , Fototerapia/métodos , Microambiente Tumoral
15.
Complement Ther Clin Pract ; 47: 101565, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35259569

RESUMO

BACKGROUND: Autism spectrum disorder (ASD) is a neurodevelopment disorder, marked by deficits in social communication and social interaction as well as by a restricted, repetitive patterns of behaviors, interests and activities. There is an increasing interest in the use of dance as part of rehabilitation for individuals with ASD. However, it is not clear how dance can influence on ASD symptoms. And few studies have measured and compared the outcomes of multiple studies. This study was aimed to provide a more comprehensive perspective of the efficacy of dance practice on ASD symptoms by conducting a systematic review with meta-analysis. METHODS: The electronic databases PubMed, EBSCO, MEDLINE, Cochrane and PsycINFO were searched for relevant studies reporting on the effects of dance on ASD symptoms. Only randomized controlled trials (RCTs) and non-randomized controlled studies were included in this review. Two review authors independently performed literature search, data extraction, and study quality assessment. Effect sizes for ASD symptoms were expressed as standardized mean differences (SMD) with 95% confidence intervals. RESULTS: Seven eligible studies were included for meta-analysis. Dance interventions varied in frequency (1-2 sessions/week), time (40 - 90 min), duration (7 - 17 weeks) and type. As compared to control groups, dance practice showed significant alleviation of overall symptoms of ASD (-1.48 points, CI -2.55 to - 0.42 points, p = 0.006, I2 = 75%) and improvement in social interaction (0.88, CI 0.46 to 1.30, p < 0.0001, I2 = 0%), but no significant effect on empathy (0.09, CI - 0.25 to 0.42, p = 0.61, I2 = 2%). CONCLUSIONS: Dance probably alleviate the negative symptoms and social deficits of individuals with ASD. However, little difference is found in empathy. Further research and studies are needed to determine the optimal dose and if dance results in greater benefits than other types of physical activity.


Assuntos
Transtorno do Espectro Autista , Transtorno do Espectro Autista/terapia , Comunicação , Empatia , Humanos
16.
Brain Behav ; 12(1): e2444, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34859605

RESUMO

INTRODUCTION: Previous findings have demonstrated that several Gestalt principles do facilitate VSTM performance in change detection tasks. However, few studies have investigated the role of and time-course of global-local consistency in motion perception. METHODS: Participants were required to track a moving target surrounded by three different backgrounds: blank, inconsistent, or consistent. Global-local objects were be bound to move together (covariation). During the PMT, participants had to follow the moving target with their eyes and react as fast as possible when the target had just vanished behind the obstruction or would arrive at a predetermined point of interception. Variable error (VE) and constant error (CE) of estimated time-to-contact (TTC) and gain of smooth pursuit eye movements were calculated in various conditions and analyzed qualitatively. RESULTS: Experiment 1 established the basic finding that VSTM performance could benefit from global-local consistency. Experiment 2 extended this finding by eye-tracking device. Both in visible phase and in occluded phase, CEs were smaller for the target in a consistent background than for the target in an inconsistent background and for the target in a blank background, with both differences significant (ps < .05). However, the difference in VE among three conditions was not significant. At early stage (100-250 ms), later stage (2750-3000 ms), and termination stage (5750-6000 ms) of smooth pursuit, the velocity gains were higher in the trials with consistent backgrounds than in the trials with inconsistent backgrounds and blank backgrounds (ps < .001). With the exception of 100-250 ms phase, the means did not differ between the inconsistent background and the blank background trials (ps > .1). CONCLUSIONS: Global-local consistency could be activated within the first few hundred milliseconds to prioritize the deployment of attention and eye movement to component target. Meanwhile, it also removes ambiguity from motion tracking and TTC estimation under some unpredictable conditions, leading to the consistency advantage during smooth-pursuit termination phase. Global-local consistency may act as an important information source to TTC estimation and oculomotor response in PMT.


Assuntos
Percepção de Movimento , Acompanhamento Ocular Uniforme , Atenção/fisiologia , Movimentos Oculares , Humanos , Percepção de Movimento/fisiologia , Estimulação Luminosa
17.
Nanomaterials (Basel) ; 11(11)2021 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-34835597

RESUMO

Presently, antibiotic resistant bacteria (ARB) have been commonly found in environment, such as air, soil and lakes. Therefore, it is urgent and necessary to prepare antimicrobial agents with excellent anti-antibiotic resistant bacteria. In our research, poly-ethylene glycol functionalized molybdenum disulfide nanoflowers (PEG-MoS2 NFs) were synthesized via a one-step hydrothermal method. As-prepared PEG-MoS2 NFs displayed excellent photothermal conversion efficiency (30.6%) and photothermal stability. Under 808 nm NIR laser irradiation for 10 min, the inhibition rate of tetracycline-resistant Bacillus tropicalis and Stenotrophomonas malphilia reached more than 95% at the concentration of 50 µg/mL. More interestingly, the photothermal effect of PEG-MoS2 NFs could accelerate the oxidation of glutathione, resulting in the rapid death of bacteria. A functionalized PEG-MoS2 NFs photothermal anti-antibiotic resistant system was constructed successfully.

18.
Pest Manag Sci ; 77(11): 5032-5048, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34223705

RESUMO

BACKGROUND: Amitraz is a broad-spectrum insecticide/acaricide for the control of aphids, psyllids, ticks and mites. Current evidence suggests that ticks and phytophagous mites have developed strong resistance to amitraz. Previous studies have shown that multiple mechanisms are associated with amitraz resistance in ticks, but very few reports have involved Panonychus citri. We therefore used whole genome sequencing and bulked segregant analysis (BSA) to identify the mechanism underlying P. citri's resistance to amitraz. RESULTS: High-quality assembly of the whole P. citri genome was completed, resulting in a genome of approximately 83.97 Mb and a contig N50 of approximately 1.81 Mb. Gene structure predictions revealed 11 577 genes, of which 10 940 genes were annotated. Trait-associated regions in the genome were mapped with bulked segregant analysis and 38 candidate SNPs were obtained, of which T752C had the strongest correlation with the resistant trait, located at the 5' untranslated region (UTR) of the ß-2R adrenergic-like octopamine receptor gene. The mutation resulted in the formation of a short hairpin loop structure in mRNA and gene expression was down-regulated by more than 50% in the amitraz-resistant strain. Validation of the T752C mutation in field populations of P. citri found that the correlation between the resistance ratio and the base mutation was 94.40%. CONCLUSION: Our results suggest that this 5' UTR mutation of the ß-2R octopamine receptor gene, confers amitraz resistance in P. citri. This discovery provides a new explanation for the mechanism of pest resistance: base mutations in the 5' untranslated region of target gene may regulate the susceptibility of pests to pesticides.


Assuntos
Acaricidas , Ácaros , Toluidinas , Animais , Ácaros/genética , Sequenciamento Completo do Genoma
19.
PLoS One ; 16(5): e0250930, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33956886

RESUMO

Modern navigation satellite communication has the characteristic of high transmitting rate. To avoid bit errors in data transmission, low density parity check (LDPC) codes are widely recognized as efficient ways for navigation communication. Conventionally, the LDPC decoding is applied for additive white Gaussian noise (AWGN) channel and degrades severely while facing the impulsive noise. However, navigation communication often suffers from impulsive interference due to the occurrence of high amplitude "spikes". At this time, the conventional Gaussian noise assumption is inadequate. The impulsive component of interference has been found to be significant which influences the reliability of transmitted information. Therefore the LDPC decoding algorithms for AWGN channel are not suitable for impulsive noise environments. Consider that LDPC codes over GF(q) perform better than binary LDPC in resisting burst errors for current navigation system, it is necessary to conduct research on LDPC codes over GF(q). In this paper, an optimized initialization by calculating posterior probabilities of received symbols is proposed for non-binary LDPC decoding on additive white Class A noise (AWAN) channel. To verify the performance of the proposed initialization, extensive experiments are performed in terms of convergence, validity, and robustness. Preliminary results demonstrate that the decoding algorithm with the optimized initialization for non-binary LDPC codes performs better than the competing methods and that of binary LDPC codes on AWAN channel.

20.
Bull Entomol Res ; 110(6): 743-755, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32419680

RESUMO

Panonychus citri (McGregor) is the most common pest in citrus-producing regions. Special low-toxicity acaricides, such as spirocyclic tetronic acids and mite growth inhibitors, have been used for a long time in China. However, pesticide resistance in mites is a growing problem due to the lack of new acaricide development. Wide-spectrum insecticides, such as amitraz have gained acceptance among fruit growers. An amitraz-resistant strain of P. citri was obtained by indoor screening to examine field resistance monitoring of mites to acaricides and to explore the resistant mechanism of mites against amitraz. The amitraz-resistant strain of P. citri had an LC50 value of 2361.45 mg l-1. The resistance ratio was 81.35 times higher in the resistant strain of P. citri compared with the sensitive strain. Crossing experiments between the sensitive and resistant strains of P. citri were conducted, resulting in a D value of 0.11 for F1 SS♀×RS♂ and 0.06 for F1 RS♀×SS♂. Reciprocal cross experiments showed that the dose-mortality curves for the F1 generations coincided, indicating that the resistance trait was not affected by cytoplasmic inheritance. The dose-expected response relationship was evaluated in the backcross generation and a significant difference was observed compared with the actual value. The above results indicate that the inheritance of resistance trait was incompletely dominant, governed by polygenes on the chromosome. Synergism studies demonstrated that cytochrome P450s and esterase may play important roles in the detoxification of amitraz. Based on differential gene analysis, 23 metabolism-related genes of P. citri were identified, consistent with the results of synergism studies. Real-time PCR verification implied that P450s, ABC transporters, and acetylcholinesterase might influence the detoxification of amitraz by P. citri. These results provide the genetic and molecular foundation for the management of pest mite resistance.


Assuntos
Inativação Metabólica/genética , Tetranychidae/genética , Tetranychidae/metabolismo , Toluidinas , Acaricidas , Animais , Sistema Enzimático do Citocromo P-450 , Esterases , Tetranychidae/enzimologia
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