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1.
Animals (Basel) ; 14(9)2024 May 04.
Artículo en Inglés | MEDLINE | ID: mdl-38731386

RESUMEN

The utilization of chicken embryonic-derived pluripotent stem cell (PSC) lines is crucial in various fields, including growth and development, vaccine and protein production, and germplasm resource protection. However, the research foundation for chicken PSCs is relatively weak, and there are still challenges in establishing a stable and efficient PSC culture system. Therefore, this study aims to investigate the effects of the FGF2/ERK and WNT/ß-catenin signaling pathways, as well as different feeder layers, on the derivation and maintenance of chicken embryonic-derived PSCs. The results of this study demonstrate that the use of STO cells as feeder layers, along with the addition of FGF2, IWR-1, and XAV-939 (FIX), allows for the efficient derivation of chicken PSC-like cells. Under the FIX culture conditions, chicken PSCs express key pluripotency genes, such as POUV, SOX2, and NANOG, as well as specific proteins SSEA-1, C-KIT, and SOX2, indicating their pluripotent nature. Additionally, the embryoid body experiment confirms that these PSC-like cells can differentiate into cells of three germ layers in vitro, highlighting their potential for multilineage differentiation. Furthermore, this study reveals that chicken Eyal-Giladi and Kochav stage X blastodermal cells express genes related to the primed state of PSCs, and the FIX culture system established in this research maintains the expression of these genes in vitro. These findings contribute significantly to the understanding and optimization of chicken PSC culture conditions and provide a foundation for further exploration of the biomedical research and biotechnological applications of chicken PSCs.

2.
Ann Gen Psychiatry ; 23(1): 17, 2024 May 09.
Artículo en Inglés | MEDLINE | ID: mdl-38724998

RESUMEN

BACKGROUND: While depression is increasing worldwide, some patients are diagnosed as having Major Depressive Disorder (MDD), but others are diagnosed with minor depression, however, the potential neuro mechanism is unknown. METHODS: Sixty-two patients with minor depression, 44 adolescents with MDD and 54 healthy adolescents participated in this study. Functional near-infrared spectroscopy (fNIRS), both HAMD and HAMA data were collected from all of the participants. RESULTS: The result indicates the pervasively decreased activation of BA, 11, 21, 45 and 46 were observed in the MDD group and reduced activation of BA 45 was observed in the minor depression group. However, cortical activation was not observed between the minor depression or MDD groups. Cortical activation was also not correlated with the depressive/anxious score in the minor and MDD groups separately. CONCLUSIONS: Cortical activation was pervasively decreased in the MDD group and slightly reduced in the minor depression group, which may be a potential neural mechanism. As reduced cortical activation in minor depression, interventions in the early stages of minor depression may help slow or even modify the development of the illness.

3.
Med Phys ; 2024 May 02.
Artículo en Inglés | MEDLINE | ID: mdl-38695760

RESUMEN

BACKGROUND: The newly available ZAP-X stereotactic radiosurgical system is designed for the treatment of intracranial lesions, with several unique features that include a self-shielding, gyroscopic gantry, wheel collimation, non-orthogonal kV imaging, short source-axis distance, and low-energy megavoltage beam. Systematic characterization of its radiation as well as other properties is imperative to ensure its safe and effective clinical application. PURPOSE: To accurately determine the radiation output of the ZAP-X with a special focus on the smaller diameter cones and an aim to provide useful recommendations on quantification of small field dosimetry. METHODS: Six different types of detectors were used to measure relative output factors at field sizes ranging from 4 to 25 mm, including the PTW microSilicon and microdiamond diodes, Exradin W2 plastic scintillator, Exradin A16 and A1SL ionization chambers, and the alanine dosimeter. The 25 mm cone served as the reference field size. Absolute dose was determined with both TG-51-based dosimetry using a calibrated PTW Semiflex ion chamber and measurements using alanine dosimeters. RESULTS: The average radiation output factors (maximum deviation from the average) measured with the microDiamond, microSilicon, and W2 detectors were: for the 4 mm cone, 0.741 (1.0%); for the 5 mm cone: 0.817 (1.0%); for the 7.5 mm cone: 0.908 (1.0%); for the 10 mm cone: 0.946 (0.4%); for the 12.5 mm cone: 0.964 (0.2%); for the 15 mm cone: 0.976 (0.1%); for the 20 mm cone: 0.990 (0.1%). For field sizes larger than 10 mm, the A1SL and A16 micro-chambers also yielded consistent output factors within 1.5% of those obtained using the microSilicon, microdiamond, and W2 detectors. The absolute dose measurement obtained with alanine was within 1.2%, consistent with combined uncertainties, compared to the PTW Semiflex chamber for the 25 mm reference cone. CONCLUSION: For field sizes less than 10 mm, the microSilicon diode, microDiamond detector, and W2 scintillator are suitable devices for accurate small field dosimetry of the ZAP-X system. For larger fields, the A1SL and A16 micro-chambers can also be used. Furthermore, alanine dosimetry can be an accurate verification of reference and absolute dose typically measured with ion chambers. Use of multiple suitable detectors and uncertainty analyses were recommended for reliable determination of small field radiation outputs.

4.
Phytochemistry ; 222: 114098, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38648960

RESUMEN

Nine undescribed compounds, along with eight known compounds, were isolated from the stipes of Lentinus edodes. Their structures were established by extensive spectroscopic and circular dichroism analyses. The protective effects against Aß25-35-induced N9 microglia cells injury of these compounds were tested by MTT method, and the levels of apoptosis and ROS were detected by flow cytometry. In addition, the binding sites and interactions of compound with amyloid precursor protein were revealed using molecular docking simulations. These findings further establish the structural diversity and bioactivity of stipes of L. edodes, and provide an experimental basis for targeting Alzheimer's disease as a potential strategy.


Asunto(s)
Péptidos beta-Amiloides , Apoptosis , Microglía , Simulación del Acoplamiento Molecular , Fragmentos de Péptidos , Microglía/efectos de los fármacos , Microglía/metabolismo , Péptidos beta-Amiloides/antagonistas & inhibidores , Péptidos beta-Amiloides/metabolismo , Fragmentos de Péptidos/farmacología , Animales , Apoptosis/efectos de los fármacos , Ratones , Estructura Molecular , Fármacos Neuroprotectores/farmacología , Fármacos Neuroprotectores/química , Fármacos Neuroprotectores/aislamiento & purificación , Especies Reactivas de Oxígeno/metabolismo , Relación Estructura-Actividad , Relación Dosis-Respuesta a Droga , Lentinula/química , Línea Celular
5.
J Pharm Pharmacol ; 2024 Apr 11.
Artículo en Inglés | MEDLINE | ID: mdl-38600792

RESUMEN

OBJECTIVES: Achyranthes bidentata Blume (A. bidentata) is a plant of Amaranthaceae family, and its root is the main medicinal part, named "Huai-Niu-Xi." It is used to expel blood stasis through menstruation, tonify liver and kidney, strengthen muscles and bones, and induce diuresis. This review aimed to provide a systematic summary of botany, traditional uses, phytochemistry, pharmacology, and toxicology of A. bidentata. METHODS: The present review covers the literature survey. The data have been collected from various journals, books, and some of the electronic search via Internet-based information such as Web of Science, PubMed, Google Scholar, Google patents, CNKI, SpringerLink, online electronic journals, and ScienceDirect. KEY FINDINGS: So far, more than 270 metabolites have been isolated from A. bidentata, including terpenoids, steroids, alkaloids, flavonoids, and so on. Among them, terpenoids and steroids are the main metabolites. The extract and metabolites exert multiple pharmacological activities such as alleviating osteoarthritis effect, antiosteoporosis activity, neuroprotective effect, antidiabetic activity-associated complications, immunoregulatory activity, and so on. SUMMARY: Some traditional uses of A. bidentata need further in-depth studies to confirm. Similarly, the separation and screening of active compounds, as well as the corresponding molecular mechanisms of action of compounds, are also needed to be studied.

6.
Huan Jing Ke Xue ; 45(5): 3059-3068, 2024 May 08.
Artículo en Chino | MEDLINE | ID: mdl-38629566

RESUMEN

Research on microplastics (MPs) is gaining more attention in the soil environment, but their impact on soil microbiota and related nitrogen processes remains poorly understood. Nitrous oxide (N2O) is one of the important greenhouse gases of the nitrogen cycle in agricultural soil, which mainly originates from microbial-mediated nitrogen (N) transformation processes. Microplastics can influence soil nitrogen transformation, as well as nitrogen-related functional enzymes and genes, and its enrichment may profoundly affect the N2O emissions in soil. However, because of the complexity of the properties of MPs, variations in experimental conditions, and spatial-temporal scales, the results on the effects of MPs on soil N2O emissions, nitrogen content, enzymes activities, and nitrogen functional genes remain inconsistent. Additionally, there is a lack of research conducted at broader experimental scales (e.g., pot scale), from diverse perspectives (e.g., denitrification or DNRA), and using advanced techniques (e.g., stable isotope approaches) to elucidate the underlying mechanisms. Therefore, to comprehend the environmental risk of MPs on soil from multiple perspectives, this review summarized the impact of MPs on soil N cycling from previous published research to provide a knowledge basis and gain holistic insights into the potential impact of soil microplastic enrichment on N2O emission patterns in agricultural soils under climate change conditions.

7.
Sci Rep ; 14(1): 7033, 2024 Mar 25.
Artículo en Inglés | MEDLINE | ID: mdl-38528145

RESUMEN

To enhance the security of image data transmission, and address the weaknesses of existing image encryption schemes based on chaotic systems, particularly concerning resistance to differential attacks and the unstable performance of chaotic systems, this article introduces an improved four-dimensional chaotic system and integrates evolutionary operators to propose an image encryption scheme. Firstly, a method for generating pseudo-random sequences associated with the plaintext is designed. The change rate of the ciphertext pixel value exceeds 0.9967 after a slight modification of the plaintext pixel value, significantly improving the plaintext sensitivity and the scheme's ability to resist selected plaintext attacks. Secondly, an individual rearrangement operation is introduced to achieve bit-level scrambling, and pixel-level scrambling is achieved by selection strategy. Subsequently, crossover and mutation operations are incorporated into image encryption. To reflect the randomness of the pairing, we adopt the pseudo-random sequence generated by the chaotic system to control the crossover and mutation operators, and a diffusion operation is performed on selected pixel pairs. Finally, ciphertext feedback is applied. Experimental results and performance analysis demonstrate that the proposed scheme not only enhances the security of encrypted images but also effectively resists noise and cropping attacks. This method effectively meets the high-security requirements of images in network transmission and provides new ideas for further research in the field of image encryption.

8.
Artículo en Inglés | MEDLINE | ID: mdl-38450723

RESUMEN

BACKGROUND: The effect of a healthy lifestyle on dementia associated with multimorbidity is not well understood. Our objective is to examine whether the adoption of a healthy lifestyle could potentially reduce the elevated risk of dementia in individuals with and without multimorbidity. METHODS: We utilized data from the UK Biobank cohort. A comprehensive healthy lifestyle score, ranging from 0 to 6, was generated. Cox proportional hazards models were used to examine the associations between multimorbidity, the healthy lifestyle score, and the incidence risk of dementia. RESULTS: Over a median follow-up period of 12.5 years, 5 852 all-cause dementia were recorded. Multimorbidity including cardiovascular, metabolic, neuropsychiatric, and inflammation-related diseases was associated with a higher risk of subsequent dementia. Each additional chronic disease was associated with a hazard ratio (HR) of 1.38 (95% CI: 1.33, 1.44). Compared to individuals without multimorbidity and a healthy lifestyle score of 5-6, patients with multimorbidity and a lifestyle score of 0-1 had a significantly higher risk of dementia (HR: 3.13; 95% CI: 2.64, 3.72), but the risk was markedly attenuated among those with multimorbidity and a lifestyle score of 5-6. Among patients with 3 or more diseases, the HR for dementia was 0.53 (95%CI: 0.42, 0.68) when comparing a lifestyle score of 5-6 to 0-1. And we observed more pronounced association between them among people younger than 60 years old. CONCLUSIONS: Adherence to a combination of healthy lifestyle factors, especially at a young age, was associated with a significantly lower risk of dementia among participants with multimorbidity.


Asunto(s)
Demencia , Multimorbilidad , Humanos , Estudios Prospectivos , Factores de Riesgo , Estilo de Vida , Estilo de Vida Saludable , Demencia/epidemiología , Demencia/etiología
9.
Ultrason Sonochem ; 103: 106783, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38364480

RESUMEN

The oxide film on the surface of the grinding wheel plays a very important role in ultrasonic-assisted electrolytic in-process dressing (UA-ELID) grinding. In order to investigate the influence of ultrasonic vibration on the characteristics of oxide film on the surface of grinding wheel in compound grinding, the formation mechanism of oxide film on the surface of grinding wheel under ultrasonic action was analyzed theoretically from two aspects: the change of single grain trajectory caused by ultrasonic vibration and the effect of ultrasonic cavitation. The pre-dressing tests were conducted with different pre-dressing times to observe the oxide layer properties at different pre-dressing stages. The grinding tests were conducted after pre-dressing to verify the grinding performance of oxide layer under different pre-dressing methods. The results show that after the ultrasonic vibration of the grinding wheel is added during electrolytic in-process dressing (ELID) process, the holes and cracks of the oxide film on the surface of the grinding wheel are greatly reduced during the whole pre-dressing process. In addition, the pre-dressing current decreases more stably and the current is smaller when it reaches stability. After the pre-dressing, the thickness of the oxide film is reduced by about 35 % and the hardness is increased by about 70 % compared with the ordinary pre-dressing process. The grinding test results show that the oxide film obtained by ultrasonic vibration of the additional grinding wheel is more conducive to improving the surface quality of the grinding process. Therefore, compared with the ordinary pre-dressing process, the density and uniformity of oxide film on the surface of grinding wheel is better and the hardness is higher after the additional ultrasonic vibration of grinding wheel. It is beneficial to improve the surface quality of workpiece.

10.
Bioinformatics ; 40(3)2024 Mar 04.
Artículo en Inglés | MEDLINE | ID: mdl-38419588

RESUMEN

MOTIVATION: DNA as a novel storage medium is considered an effective solution to the world's growing demand for information due to its high density and long-lasting reliability. However, early coding schemes ignored the biologically constrained nature of DNA sequences in pursuit of high density, leading to DNA synthesis and sequencing difficulties. This article proposes a novel DNA storage coding scheme. The system encodes half of the binary data using each of the two GC-content complementary encoding rules to obtain a DNA sequence. RESULTS: After simulating the encoding of representative document and image file formats, a DNA sequence strictly conforming to biological constraints was obtained, reaching a coding potential of 1.66 bit/nt. In the decoding process, a mechanism to prevent error propagation was introduced. The simulation results demonstrate that by adding Reed-Solomon code, 90% of the data can still be recovered after introducing a 2% error, proving that the proposed DNA storage scheme has high robustness and reliability. Availability and implementation: The source code for the codec scheme of this paper is available at https://github.com/Mooreniah/DNA-dual-rule-rotary-encoding-storage-system-DRRC.


Asunto(s)
ADN , Programas Informáticos , Composición de Base , Reproducibilidad de los Resultados , ADN/genética , Replicación del ADN
11.
Theriogenology ; 215: 67-77, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38011785

RESUMEN

Chicken primordial germ cells (PGCs) are important cells with significant implications in preserving genetic resources, chicken breeding and production, and basic research on genetics and development. Currently, chicken PGCs can be cultured long-term in vitro to produce single-cell clones. However, systematic exploration of the cellular characteristics of these single-cell clonal lines has yet to be conducted. In this study, single-cell clonal lines were established from male and female PGCs of Rugao Yellow Chicken and Shouguang Black Chicken, respectively, using a micropipette-based method for single-cell isolation and culture. Analysis of glycogen granule staining, mRNA expression of pluripotency marker genes (POUV, SOX2, NANOG), germ cell marker genes (DAZL, CVH), and SSEA-1, EMA-1, SOX2, C-KIT, and CVH protein expression showed positive results, indicating that PGCs maintain normal cellular properties after single-cell cloning. Furthermore, tests on proliferation ability and gene expression levels in PGC single-cell clonal lines showed high expression of the pluripotency-related genes and TERT compared to control PGCs, and PGC single-cell clonal lines demonstrated higher proliferation ability. Finally, green fluorescent protein (GFP)-PGC single-cell clonal lines were established, and it was found that these single-cell clonal lines could still migrate into the gonads of recipients, suggesting their potential for germ-line transmission. This study systematically validated the normal cellular characteristics of PGC single-cell clonal lines, indicating that they could be applied in genetic modification research on chickens.


Asunto(s)
Pollos , Células Germinativas , Animales , Masculino , Femenino , Pollos/genética , Línea Celular , Células Cultivadas , Células Germinativas/metabolismo , Proteínas Proto-Oncogénicas c-kit/metabolismo
12.
BMC Psychiatry ; 23(1): 898, 2023 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-38041012

RESUMEN

BACKGROUND: This study aims to explore the psychological characteristics, related emotional problems and potential NIR brain function mechanism of adolescents who refuse to attend school. METHODS: The study included 38 adolescents (12-18 years old) who were not attending school and 35 healthy controls (12-18 years old) who are attending school regularly. Participants completed (1) general demographics, (2) Eysenck Personality Questionnaire (EPQ), (3) Zung Self-Rating Depression Scale (SDS), (4) Zung Self-Rating Anxiety Scale (SAS), and (5) Symptom Checklist-90 (SCL-90). In addition to the clinical tests, participants completed functional near-infrared spectroscopy (fNIRS). Mental health, personality, and emotional state were evaluated in both groups to explore the differences and to understand the underlying mechanisms of school refusal during adolescence. RESULTS: Adolescents who did not attend school had higher neuroticism scores on the Eysenck Personality Questionnaire than healthy controls (p(FDR) < 0.001), introversion and concealment scores were lower than those of healthy controls (p(FDR) < 0.001), there was no significant difference in psychoticism scores between groups. SDS, SAS, SCL-90 scores and factor scores were higher than those of healthy control group (p(FDR) < 0.001), NIR functional brain imaging was different from healthy control group in the 12 and 27 channels (p(FDR) = 0.030, p(FDR) = 0.018), and no difference was found in the remaining channels (p(FDR) > 0.05). There were statistically significant differences in age and gender between the adolescents who refused school and the control group (p(FDR) < 0.001). CONCLUSION: School refusal adolescents are relatively introverted and sensitive and need more attention in daily life. Although the adolescents' emotional problems did not reach the diagnostic criteria of depressive disorder and anxiety disorder, their scores were still higher than those of the control group, suggesting that we should pay more attention to their emotional problems in order to better help them return to school. Using fNIRS, it was found that abnormalities in frontal lobe regions in adolescents with school refusal behaviors, which would contribute to early diagnosis and timely intervention of school refusal behaviors.


Asunto(s)
Emociones , Espectroscopía Infrarroja Corta , Humanos , Adolescente , Niño , Depresión/diagnóstico , Depresión/psicología , Trastornos de Ansiedad , Instituciones Académicas
13.
Micromachines (Basel) ; 14(11)2023 Nov 02.
Artículo en Inglés | MEDLINE | ID: mdl-38004913

RESUMEN

Longitudinal-torsional composite ultrasonic vibration has been widely used in grinding. This paper aims to solve the problem that the resonance frequency deviates greatly from the theoretical design frequency and the vibration mode is poor when the horn is matched with a larger tool head. This paper presents how the longitudinal-torsional composite ultrasonic conical transition horn was designed and optimized by the transfer matrix theory and finite element simulation. For this purpose, the spiral groove parameters were optimized and selected by finite element simulation. Then, the modal analysis and transient dynamic analysis of the horn with grinding wheel were carried out to verify the correctness of the theoretical calculation. The impedance analysis and amplitude test of the horn with grinding wheel were carried out. The test results were in very good agreement with the theoretical and simulation results. Finally, the grinding experiment was carried out. The surface roughness of the workpiece in longitudinal-torsional ultrasonic vibration grinding was obviously reduced compared to that of ordinary grinding. All these obtained results demonstrate that the designed longitudinal-torsional composite ultrasonic horn has very good operational performance for practical applications.

14.
Phytochemistry ; 216: 113865, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37743005

RESUMEN

Three pairs of undescribed diarylpentanoid enantiomers (1-3) and five undescribed phenylpropanoids (4-8), along with seven known compounds, were isolated from the roots of Anthriscus sylvestris. The structures of compounds (1-8) were determined by analysis of their 1D and 2D NMR spectra, HRESIMS, and electronic circular dichroism. In addition, the inhibitory activities against hypoxia-stimulated pulmonary arterial smooth muscle cells abnormal proliferation were evaluated by MTT assay. The mRNA expression levels of Bcl-2, BAX, Caspase3, and IL-6 were detected by quantitative real-time PCR. The results showed that compounds (-)-1, (+)-1, (-)-2, (+)-3, 4, 8-10, 14, and 15 inhibited the abnormal proliferation of PASMCs by regulating the levels of apoptosis and inflammatory factors.


Asunto(s)
Apiaceae , Extractos Vegetales , Extractos Vegetales/química , Arteria Pulmonar , Proliferación Celular
15.
Front Microbiol ; 14: 1153188, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37533828

RESUMEN

Background: Mycophenolic acid (MPA)-induced colitis was still a severe side effect and challenge faced by solid transplant recipients. We aimed to explore the function and mechanism of probiotics in the treatment of MPA-induced colitis. Methods: In this study, 15 mice (C57BL/6) were randomly assigned into three groups: control (CNTL) group (n = 5), MPA group (n = 5) and the MPA + Probiotic group (n = 5). Bifid Triple Viable capsules, which were drugs for clinical use and consisted of Bifidobacterium longum, Lactobacillus acidophilus, and Enterococcus faecalis, were used in Probiotic group. Body weight change, stool scores, colon histopathology and morphology were used to evaluate the disease severity. The intestinal mucosal barrier function was assessed by measuring the expression level of secretory immunoglobulin A (sIgA), Zonula occludens-1 (ZO-1) and Occludin. Finally, 16S rDNA sequencing and bioinformatics analysis were performed on mice feces to compare the different intestinal microbial composition and diversity among three groups. Results: Compared with the CNTL group, the mice in MPA group showed a significantly decreased body weight, increased stool scores, shortened colon length and severe colon inflammation. However, probiotics treated MPA mice reversed the disease severity, indicating that probiotics ameliorated MPA-induced colitis in mice. Mechanistically, probiotics improved the intestinal barrier function by up-regulating the expression of sIgA, ZO-1 and Occludin. Moreover, MPA-induced colitis led to intestinal microbiota dysbiosis, including the change of Firmicutes/Bacteroidetes ratio, α- and ß-diversity. But probiotic treated group showed mild change in these microbial features. Additionally, we found that Clostridiales was the most significantly different microbiota flora in MPA group. Conclusion: Probiotics treatment ameliorated MPA-induced colitis by enhancing intestinal barrier function and improving intestinal microbiota dysbiosis. Clostridiales might be the dominant functional intestinal microflora and serve as the potential therapy target in MPA-induced colitis.

16.
Micromachines (Basel) ; 14(8)2023 Aug 17.
Artículo en Inglés | MEDLINE | ID: mdl-37630163

RESUMEN

The common material of bearing rings is GCr15 bearing steel which is a typical difficult-to-machine material. As an important working surface of the bearing, the inner surface of the raceway plays a vital role in the performance of the bearing. As an important means to solve the high-performance manufacturing of difficult-to-machine materials, longitudinal-torsional ultrasonic processing is widely used in various types of processing. In the presented work, the basic size of the horn is obtained from the wave equation of the forced vibration, and the modal analysis and amplitude test are carried out to verify the rationality of the LUTG structure. Then, according to the probability density function of cutting thickness and the overlapping effect of adjacent abrasive trajectories, the LUTG surface topography prediction model is established by using the height formula of the surface residual material, and the model reliability is verified by using the orthogonal test. The error between the test results and the prediction model is within 13.2%. Finally, based on the response surface method, the optimal process parameters that can meet the requirements of low roughness (Ra) and high material removal rate (MRR) are screened, and the optimal combination of process parameters is obtained as follows: A = 4.5 µm, n = 6493.3 r/min, ap = 28.4 µm, and vf = 21.1 mm/min.

17.
Toxins (Basel) ; 15(7)2023 07 22.
Artículo en Inglés | MEDLINE | ID: mdl-37505743

RESUMEN

The wide occurrence of resistance to Cry1A and Cry2A insecticidal toxins from Bacillus thuringiensis (Bt) in the corn earworm/bollworm Helicoverpa zea (Boddie) leaves the Vip3A toxin produced during the vegetative stage of Bt as the only fully active toxin expressed in transgenic crops to control H. zea in the U.S.A. During 2021, the first unexpected survival of H. zea and injury (UXI) on a maize hybrid expressing Cry1A.105, Cry2Ab2, and Vip3Aa in Louisiana, U.S.A. were observed in two sentinel plots used for resistance monitoring. A follow-up intensive investigation was conducted with two H. zea populations established from larvae collected from the two UXI plots. The main goal of this study was to reveal if the unexpected damage was due to resistance development in the insect to the Bt toxins expressed in the maize hybrid. Diet-overlay bioassays showed that the two populations were highly resistant to Cry1A.105, moderately resistant to Cry2Ab2, but still highly susceptible to Vip3Aa when compared to a reference susceptible strain. In 10 d assays with detached ears, the larvae of the two UXI populations exhibited survival on ears expressing only Cry toxins but presented near 100% mortality on maize hybrids containing both cry and vip3A transgenes. Multiple field trials over three years demonstrated that natural H. zea populations in Louisiana were highly resistant to maize expressing only Cry toxins but remained susceptible to all tested hybrids containing cry and vip3A genes. Altogether, the results of this study suggest that the observed UXIs in Louisiana were associated with a resistance to Cry toxins but were not due to a resistance to Vip3A. The possible causes of the UXIs are discussed. The results generated and procedures adopted in this study help in determining thresholds for defining UXIs, assessing resistance risks, and documenting field resistance.


Asunto(s)
Bacillus thuringiensis , Mariposas Nocturnas , Animales , Zea mays/genética , Plantas Modificadas Genéticamente/genética , Proteínas Bacterianas/farmacología , Proteínas Bacterianas/toxicidad , Mariposas Nocturnas/genética , Endotoxinas/genética , Larva , Animales Modificados Genéticamente , Bacillus thuringiensis/genética , Proteínas Hemolisinas/genética , Proteínas Hemolisinas/farmacología , Resistencia a los Insecticidas/genética
18.
Brain Lang ; 241: 105267, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-37121022

RESUMEN

The present study examined the effect of both morphological complexity and semantic transparency in Chinese compound word recognition. Using a visual lexical decision task, our electrophysiological results showed that transparent and opaque compounds induced stronger Left Anterior Negativity (LAN) than monomorphemic words. This result suggests that Chinese compounds might be decomposed into their constituent morphemes at the lemma level, whereas monomorphemic words are accessed as a whole-word lemma directly from the form level. In addition, transparent and opaque compounds produced a similar N400 as each other, suggesting that transparency did not show an effect on the involvement of constituent morphemes during access to the whole-word lemma. Two behavioral experiments additionally showed similar patterns to the EEG results. These findings support morphological decomposition for compounds at the lemma level as proposed by the full-parsing model, and no evidence is found to support the role of transparency during Chinese compound word recognition.


Asunto(s)
Electroencefalografía , Lenguaje , Vocabulario , Humanos , Potenciales Evocados/fisiología , Semántica
19.
Heliyon ; 9(3): e14273, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36938464

RESUMEN

Bearings are the core basic components that determine the stable operation of high-end equipment. The traditional processing technology of the raceway surface has been unable to meet the current processing requirements of high precision and high surface quality under the premise of certain efficiency. As one of the ultra-precision grinding technologies, electrochemical grinding (ECG) combines the advantages of electrochemical machining, makes up for the shortcomings of traditional grinding, and provides an effective way to solve this problem. In this paper, the ECG is successfully applied to the internal grinding process of the bearing raceway in combination with the plunge machining. The machining principle of the plunge ECG is described in detail. Based on this, the material removal speed model of the workpiece in the equilibrium state is established. Finally, the effects of main processing parameters such as processing voltage and feed rate on the surface roughness, microhardness, and residual stress of the workpiece after processing are explored through experiments.

20.
Micromachines (Basel) ; 14(1)2023 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-36677283

RESUMEN

During the process of internal cylindrical ultrasonic-assisted electrochemical grinding (ICUAECG), both the workpiece and the conductive grinding wheel are rotating, the machining space is closed and narrow, the electrolyte is difficult to spray into the machining area, and the insulation between the workpiece and the machine bed is challenging. According to the machining characteristics of ICUAECG, the structure of a special machine tool was designed to mitigate these problems. In particular, the rotation, electrolyte supply, electric connection, and insulation modes of the workpiece clamping parts were studied, yielding a novel workpiece clamping- and rotating-device design. This structure can fully use the internal space of the hollow spindle of the machine tool, effectively reduce the external moving parts, and achieve the appropriate liquid injection angle of the electrolyte. The ultrasonic vibration system and its installation mechanism, the dressing device of the conductive grinding wheel, and the electric grinding spindle-mounting and -fixing device were analyzed in detail. Then, a special machine tool for ICUAECG was designed, the operability and feasibility of which were verified by experiments involving conductive grinding wheel dressing and ICUAECG.

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