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1.
Pestic Biochem Physiol ; 202: 105958, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38879340

RESUMEN

The wheat aphid Sitobion miscanthi is a dominant and destructive pest in agricultural production. Insecticides are the main substances used for effective control of wheat aphids. However, their extensive application has caused severe resistance of wheat aphids to some insecticides; therefore, exploring resistance mechanisms is essential for wheat aphid management. In the present study, CYP6CY2, a new P450 gene, was isolated and overexpressed in the imidacloprid-resistant strain (SM-R) compared to the imidacloprid-susceptible strain (SM-S). The increased sensitivity of S. miscanthi to imidacloprid after knockdown of CYP6CY2 indicates that it could be associated with imidacloprid resistance. Subsequently, the posttranscriptional regulation of CYP6CY2 in the 3' UTR by miR-3037 was confirmed, and CYP6CY2 participated in imidacloprid resistance. This finding is critical for determining the role of P450 in relation to the resistance of S. miscanthi to imidacloprid. It is of great significance to understand this regulatory mechanism of P450 expression in the resistance of S. miscanthi to neonicotinoids.


Asunto(s)
Áfidos , Sistema Enzimático del Citocromo P-450 , Resistencia a los Insecticidas , Insecticidas , MicroARNs , Neonicotinoides , Nitrocompuestos , Neonicotinoides/farmacología , Nitrocompuestos/farmacología , Animales , Insecticidas/farmacología , Resistencia a los Insecticidas/genética , Áfidos/genética , Áfidos/efectos de los fármacos , MicroARNs/genética , MicroARNs/metabolismo , Sistema Enzimático del Citocromo P-450/genética , Sistema Enzimático del Citocromo P-450/metabolismo , Proteínas de Insectos/genética , Proteínas de Insectos/metabolismo , Imidazoles/farmacología
2.
Phys Rev Lett ; 132(19): 193602, 2024 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-38804940

RESUMEN

We demonstrate the emergence of nonreciprocal superradiant phase transitions and novel multicriticality in a cavity quantum electrodynamics system, where a two-level atom interacts with two counterpropagating modes of a whispering-gallery-mode microcavity. The cavity rotates at a certain angular velocity and is directionally squeezed by a unidirectional parametric pumping χ^{(2)} nonlinearity. The combination of cavity rotation and directional squeezing leads to nonreciprocal first- and second-order superradiant phase transitions. These transitions do not require ultrastrong atom-field couplings and can be easily controlled by the external pump field. Through a full quantum description of the system Hamiltonian, we identify two types of multicritical points in the phase diagram, both of which exhibit controllable nonreciprocity. These results open a new door for all-optical manipulation of superradiant transitions and multicritical behaviors in light-matter systems, with potential applications in engineering various integrated nonreciprocal quantum devices.

3.
Nanoscale ; 16(21): 10333-10339, 2024 May 30.
Artículo en Inglés | MEDLINE | ID: mdl-38738596

RESUMEN

We report an experimental study of quantum point contacts defined in a high-quality strained germanium quantum well with layered electric gates. At a zero magnetic field, we observed quantized conductance plateaus in units of 2e2/h. Bias-spectroscopy measurements reveal that the energy spacing between successive one-dimensional subbands ranges from 1.5 to 5 meV as a consequence of the small effective mass of the holes and the narrow gate constrictions. At finite magnetic fields perpendicular to the device plane, the edges of the conductance plateaus get split due to the Zeeman effect and Landé g factors were estimated to be ∼6.6 for the holes in the germanium quantum well. We demonstrate that all quantum point contacts in the same device have comparable performances, indicating a reliable and reproducible device fabrication process. Thus, our work lays a foundation for investigating multiple forefronts of physics in germanium-based quantum devices that require quantum point contacts as building blocks.

4.
Environ Sci Pollut Res Int ; 31(5): 7872-7888, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38170358

RESUMEN

In order to meet the needs of refined landslide risk management, the extended correlation framework of dynamic susceptibility modeling desiderates to be further explored. This work considered the Wanzhou channel of the Three Gorges Reservoir Area as the experimental site, with a transportation channel with significant economic value to carry out innovative research in two stages. (i) Five machine learning models logistic regression (LR), multilayer perceptron neural network (MLPNN), support vector machine (SVM), random forest (RF), and decision tree (DT) were used to explore landslide susceptibility distribution based on detailed landslide boundaries. (ii) Based on the PS-InSAR technology, the dynamic factor of deformation intensity was obtained. Subsequently, the dynamic factor was combined with proposed static factors (topography conditions, geological conditions, hydrological conditions, and human activities) to generate dynamic landslide susceptibility mapping (DLSM). The receiver operating characteristic (ROC) curve, accuracy, precision, recall, and F1 score were proposed as evaluation metrics. Compared with ignoring the dynamic factor, the predictive accuracy of some models was further improved when considering the dynamic factor. Especially the DT model, the area under the curve of ROC (AUC) value increased by 2%, and obtained the highest AUC value (93.1%). The susceptibility results of introducing the dynamic factor are more in line with the spatial distribution of actual landslides. The research framework proposed in this study has important reference significance for the dynamic management and prevention of landslide disasters in the study area.


Asunto(s)
Desastres , Deslizamientos de Tierra , Humanos , Deslizamientos de Tierra/prevención & control , Sistemas de Información Geográfica , Redes Neurales de la Computación , Máquina de Vectores de Soporte
5.
Fundam Res ; 3(1): 63-74, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38933568

RESUMEN

Cavity optomechanics provides a powerful platform for observing many interesting classical and quantum nonlinear phenomena due to the radiation-pressure coupling between its optical and mechanical modes. In particular, the chaos induced by optomechanical nonlinearity has been of great concern because of its importance both in fundamental physics and potential applications ranging from secret information processing to optical communications. This review focuses on the chaotic dynamics in optomechanical systems. The basic theory of general nonlinear dynamics and the fundamental properties of chaos are introduced. Several nonlinear dynamical effects in optomechanical systems are demonstrated. Moreover, recent remarkable theoretical and experimental efforts in manipulating optomechanical chaotic motions are addressed. Future perspectives of chaos in hybrid systems are also discussed.

6.
Opt Express ; 30(15): 26941-26954, 2022 Jul 18.
Artículo en Inglés | MEDLINE | ID: mdl-36236876

RESUMEN

In the reference interferometer demodulation scheme, it's difficult to guarantee in practice that both interferometers have the same optical path length difference (OPD), which makes the phase modulation depth different in different interferometers with the same laser modulation. The random shift of phase modulation depth also affects the demodulation results. An improved phase-generated carrier (PGC) technique is proposed based on an auxiliary reference interferometer and the ellipse fitting algorithm (EFA). The technique ensures the correct fitting of the EFA for small amplitude signals by introducing a sinusoidal signal as an additional phase modulation. The combination of the reference interferometer and EFA can eliminate the effect of different phase modulation depths of the two interferometers caused by different OPDs, the non-linear distortion caused by phase modulation depth shifts, and improve the accuracy of the demodulation results. The experiment results are consistent with the theoretical analysis, and the method extends the application of the EFA in the reference interferometer phase demodulation technique.

7.
Pestic Biochem Physiol ; 187: 105218, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-36127060

RESUMEN

The Chinese wheat aphid Sitobion miscanthi (CWA) is an important harmful pest in wheat fields. Imidacloprid plays a critical role in controlling pests with sucking mouthparts. However, imidacloprid-resistant pests have been observed after insecticide overuse. Point mutations and low expression levels of the nicotinic acetylcholine receptor ß1 (nAchRß1) subunit are the main imidacloprid-resistant mechanisms. However, the regulatory mechanism underlying nAChRß1 subunit expression is poorly understood. In this study, a target of miR-263b was isolated from the 5'UTR of the nAchRß1 subunit in the CWA. Low expression levels were found in the imidacloprid-resistant strain CWA. Luciferase reporter assays showed that miR-263b could combine with the 5'UTR of the nAChRß1 subunit and suppress its expression by binding to a site in the CWA. Aphids treated with the miR-263b agomir exhibited a significantly reduced abundance of the nAchRß1 subunit and increased imidacloprid resistance. In contrast, aphids treated with the miR-263b antagomir exhibited significantly increased nAchRß1 subunit abundance and decreased imidacloprid resistance. These results provide a basis for an improved understanding of the posttranscriptional regulatory mechanism of the nAChRß1 subunit and further elucidate the function of miRNAs in regulating susceptibility to imidacloprid in the CWA. These results provide a better understanding of the mechanisms of posttranscriptional regulation of nAChRß1 and will be helpful for further studies on the role of miRNAs in the regulation of nAChRß1 subunit resistance in homopteran pests.


Asunto(s)
Áfidos , Insecticidas , MicroARNs , Receptores Nicotínicos , Regiones no Traducidas 5' , Animales , Antagomirs , Áfidos/genética , Áfidos/metabolismo , Resistencia a los Insecticidas/genética , Insecticidas/farmacología , MicroARNs/genética , Neonicotinoides , Nitrocompuestos , Receptores Nicotínicos/genética , Receptores Nicotínicos/metabolismo
8.
Drug Dev Ind Pharm ; 48(4): 140-145, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-35822245

RESUMEN

Establishing documented evidence that provides a high degree of assurance that a specific wet granulation process for manufacturing rosuvastatin calcium tablets 40 mg will consistently produce a product meeting its pre-determined specifications and quality attributes. It mainly involves the steps to be followed to evaluate and qualify the acceptability of the wet granulation manufacturing process of rosuvastatin calcium tablets 40 mg. The process is limited to the three batches manufactured of specific batch size with specified equipment and control parameters for rosuvastatin calcium tablets 40 mg. The results suggest providing documentary evidence that all the manufactured rosuvastatin calcium tablets were evaluated as per specifications. The steps involved such as Blend uniformity results between 90% and 110%, compression assay results between 90% and 110% were found within acceptable limits. Other tests related to compression such as hardness, thickness, disintegration, dissolution and for coatings such as weight gain, dissolution was found within acceptable limit. The design was chosen for fasting and fed study and showed bioequivalence with RLD (Codine®), with 90% CI values found to be between 80% and 125%.


Asunto(s)
Calcio , Excipientes , Rosuvastatina Cálcica , Solubilidad , Comprimidos
9.
Bull Entomol Res ; 112(5): 646-655, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-35172917

RESUMEN

The wheat aphid Sitobion miscanthi (CWA) is an important harmful pest in wheat fields. Insecticide application is the main method to effectively control wheat aphids. However, CWA has developed resistance to some insecticides due to its extensive application, and understanding resistance mechanisms is crucial for the management of CWA. In our study, a new P450 gene, CYP4CJ6, was identified from CWA and showed a positive response to imidacloprid and thiamethoxam. Transcription of CYP4CJ6 was significantly induced by both imidacloprid and thiamethoxam, and overexpression of CYP4CJ6 in the imidacloprid-resistant strain was also observed. The sensitivity of CWA to these two insecticides was increased after the knockdown of CYP4CJ6. These results indicated that CYP4CJ6 could be associated with CWA resistance to imidacloprid and thiamethoxam. Subsequently, the posttranscriptional regulatory mechanism was assessed, and miR-316 was confirmed to participate in the posttranscriptional regulation of CYP4CJ6. These results are crucial for clarifying the roles of P450 in the resistance of CWA to insecticides.


Asunto(s)
Áfidos , Insecticidas , Animales , Insecticidas/farmacología , Áfidos/fisiología , Tiametoxam/farmacología , Resistencia a los Insecticidas/genética , Neonicotinoides/farmacología , Nitrocompuestos/farmacología
10.
Bull Entomol Res ; 112(2): 171-178, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-34365981

RESUMEN

Cytochrome P450 monooxygenases play a key role in pest resistance to insecticides by detoxification. Four new P450 genes, CYP6AS160, CYP6AS161, CYP4AB73 and CYP4G232 were identified from Solenopsis invicta. CYP6AS160 was highly expressed in the abdomen and its expression could be induced significantly with exposure to fipronil, whereas CYP4AB73 was not highly expressed in the abdomen and its expression could not be significantly induced following exposure to fipronil. Expression levels of CYP6AS160 and CYP4AB73 in workers were significantly higher than that in queens. RNA interference-mediated gene silencing by feeding on double-stranded RNA (dsRNA) found that the levels of this transcript decreased (by maximum to 64.6%) when they fed on CYP6AS160-specific dsRNA. Workers fed dsCYP6AS160 had significantly higher mortality after 24 h of exposure to fipronil compared to controls. Workers fed dsCYP6AS160 had reduced total P450 activity of microsomal preparations toward model substrates p-nitroanisole. However, the knockdown of a non-overexpressed P450 gene, CYP4AB73 did not lead to an increase of mortality or a decrease of total P450 activity. The knockdown effects of CYP6AS160 on worker susceptibility to fipronil, combined with our other findings, indicate that CYP6AS160 is responsible for detoxification of fipronil. Feeding insects dsRNA may be a general strategy to trigger RNA interference and may find applications in entomological research and in the control of insect pests in the field.


Asunto(s)
Hormigas , Insecticidas , Animales , Hormigas/genética , Insecticidas/farmacología , Pirazoles , Interferencia de ARN , ARN Bicatenario
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