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1.
Analyst ; 149(7): 1988-1997, 2024 Mar 25.
Artículo en Inglés | MEDLINE | ID: mdl-38420857

RESUMEN

Chromosomal instability (CIN) is a source of genetic variation and is highly linked to the malignance of cancer. Determining the degree of CIN is necessary for understanding the role that it plays in tumor development. There is currently a lack of research on high-resolution characterization of CIN and the relationship between CIN and cell mechanics. Here, a method to determine CIN of breast cancer cells by high resolution imaging with atomic force microscopy (AFM) is explored. The numerical and structural changes of chromosomes in human breast cells (MCF-10A), moderately malignant breast cells (MCF-7) and highly malignant breast cells (MDA-MB-231) were observed and analyzed by AFM. Meanwhile, the nuclei, cytoskeleton and cell mechanics of the three kinds of cells were also investigated. The results showed the differences in CIN between the benign and cancer cells. Also, the degree of structural CIN increased with enhanced malignancy of cancer cells. This was also demonstrated by calculating the probability of micronucleus formation in these three kinds of cells. Meanwhile, we found that the area of the nucleus was related to the number of chromosomes in the nucleus. In addition, reduced or even aggregated actin fibers led to decreased elasticities in MCF-7 and MDA-MB-231 cells. It was found that the rearrangement of actin fibers would affect the nucleus, and then lead to wrong mitosis and CIN. Using AFM to detect chromosomal changes in cells with different malignancy degrees provides a new detection method for the study of cell carcinogenesis with a perspective for targeted therapy of cancer.


Asunto(s)
Actinas , Neoplasias de la Mama , Humanos , Femenino , Microscopía de Fuerza Atómica/métodos , Neoplasias de la Mama/genética , Inestabilidad Cromosómica , Mama
2.
Sensors (Basel) ; 24(2)2024 Jan 20.
Artículo en Inglés | MEDLINE | ID: mdl-38276356

RESUMEN

This paper presents a novel design and control strategies for a parallel two degrees-of-freedom (DOF) flexure-based micropositioning stage for large-range manipulation applications. The motion-guiding beam utilizes a compound hybrid compliant prismatic joint (CHCPJ) composed of corrugated and leaf flexures, ensuring increased compliance in primary directions and optimal stress distribution with minimal longitudinal length. Additionally, a four-beam parallelogram compliant prismatic joint (4BPCPJ) is used to improve the motion decoupling performance by increasing the off-axis to primary stiffness ratio. The mechanism's output compliance and dynamic characteristics are analyzed using the compliance matrix method and Lagrange approach, respectively. The accuracy of the analysis is verified through finite element analysis (FEA) simulation. In order to examine the mechanism performance, a laser interferometer-based experimental setup is established. In addition, a linear active disturbance rejection control (LADRC) is developed to enhance the motion quality. Experimental results illustrate that the mechanism has the capability to provide a range of 2.5 mm and a resolution of 0.4 µm in both the X and Y axes. Furthermore, the developed stage has improved trajectory tracking and disturbance rejection capabilities.

3.
Mol Pharm ; 20(11): 5579-5592, 2023 11 06.
Artículo en Inglés | MEDLINE | ID: mdl-37844208

RESUMEN

Hypoxic tumor cell-derived exosomes play a key role in the occurrence, development, and metastasis of tumors. However, the mechanism of hypoxia-mediated metastasis remains unclear. In this study, hypoxic hepatocellular carcinoma cell (HCC-LM3)-derived exosomes (H-LM3-exos) were used to induce hepatocytes (HL-7702) over a long term (40 passages in 120 days). A nude mouse experiment further verified the effect of H-LM3-exos on tumor growth and metastasis. The process of cancer development in hepatocytes induced by H-LM3-exos was analyzed using both biological and physical techniques, and the results showed that the proliferation and soft agar growth abilities of the transformed cells were enhanced. The concentration of tumor markers secreted by transformed cells was increased, the cytoskeleton was disordered, and the migration ability was enhanced and was accompanied by epithelial-mesenchymal transition (EMT). Transcriptome results showed that differentially expressed genes between transformed cells and hepatocytes were enriched in cancer-related signaling pathways. The degree of cancer development in transformed cells was enhanced by an increase in H-LM3-exos-induced passages. Nude mice treated with different concentrations of H-LM3-exos showed different degrees of tumor growth and liver lesions. The physical properties of the cells were characterized by atomic force microscopy. Compared with the hepatocytes, the height and roughness of the transformed cells were increased, while the adhesion and elastic modulus were decreased. The changes in physical properties of primary tumor cells and hepatocytes in nude mice were consistent with this trend. Our study linking omics with the physical properties of cells provides a new direction for studying the mechanisms of cancer development and metastasis.


Asunto(s)
Carcinoma Hepatocelular , Exosomas , Neoplasias Hepáticas , Ratones , Animales , Carcinoma Hepatocelular/patología , Neoplasias Hepáticas/patología , Ratones Desnudos , Exosomas/metabolismo , Línea Celular Tumoral , Hepatocitos/metabolismo , Hipoxia/metabolismo
4.
Langmuir ; 39(37): 13212-13221, 2023 09 19.
Artículo en Inglés | MEDLINE | ID: mdl-37681704

RESUMEN

The chromosomal structure derived from UVB-stimulated HaCaT cells was detected by atomic force microscopy (AFM) to evaluate the effect of UVB irradiation. The results showed that the higher the UVB irradiation dose, the more the cells that had chromosome aberration. At the same time, different representative types of chromosome structural aberrations were investigated. We also revealed damage to both DNA and cells under the corresponding irradiation doses. It was found that the degree of DNA damage was directly proportional to the irradiation dose. The mechanical properties of cells were also changed after UVB irradiation, suggesting that cells experienced a series of chain reactions from inside to outside after irradiation. The high-resolution imaging of chromosome structures by AFM after UVB irradiation enables us to relate the damage between chromosomes, DNA, and cells caused by UVB irradiation and provides specific information on genetic effects.


Asunto(s)
Daño del ADN , Rayos Ultravioleta , Microscopía de Fuerza Atómica , Rayos Ultravioleta/efectos adversos , Cromosomas
5.
J Microsc ; 289(3): 187-197, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36565476

RESUMEN

Currently, silver nanoparticles (AgNPs) are the most produced nanoparticles in global market and have been widely utilized in the biomedical field. Here, we investigated the morphological and mechanical effects of AgNPs on cancerous cells of A549 cells and SMMC-7721 cells with atomic force microscope (AFM). The influence of AgNPs on the morphological properties and mechanical properties of cancerous cells were characterized utilizing the force-volume (FV) mode and force spectroscopy (FS) mode of AFM measurement. We mainly focus on the comparison of the effects of AgNPs on the two types of cancerous cells based on the fitting results of calculating the Young's moduli utilizing the Sneddon model. The results showed that the morphology changed little, but the mechanical properties of height, roughness, adhesion force and Young's moduli of two cancerous cells varied significantly with the stimulation of different concentrations of AgNPs. This research has provided insights into the classification and characterization of the effects of the various concentrations of AgNPs on the cancerous cells in vitro by utilizing AFM methodologies for disease therapy.


Asunto(s)
Nanopartículas del Metal , Nanopartículas del Metal/química , Plata/farmacología , Plata/química , Módulo de Elasticidad , Microscopía de Fuerza Atómica/métodos
6.
Chem Soc Rev ; 51(20): 8476-8583, 2022 Oct 17.
Artículo en Inglés | MEDLINE | ID: mdl-36189687

RESUMEN

Liquid-repellent surfaces, such as superhydrophobic surfaces, superoleophobic surfaces, and slippery liquid-infused surfaces, have drawn keen research interest from the communities engaged in chemical synthesis, interfacial chemistry, surface engineering, bionic manufacturing and micro-nano machining. This is due to their great potential applications in liquid-proofing, self-cleaning, chemical resistance, anti-icing, water/oil remediation, biomedicine, etc. However, poor robustness and durability that notably hinders the real-world applications of such surfaces remains their Achilles heel. The past few years have witnessed rapidly increasing publications that address the robustness and durability of liquid-repellent surfaces, and many breakthroughs have been achieved. This review provides an overview of the recent progress made towards robust and durable liquid-repellent surfaces. First, we discuss the wetting of solid surface and its generally-adopted characterisation methods, and introduce typical liquid-repellent surfaces. Second, we focus on various evaluation methods of the robustness and durability of liquid-repellent surfaces. Third, the recent advances in design and fabrication of robust and durable liquid-repellent surfaces are reviewed in detail. Fourth, we present the applications where these surfaces have been employed in fields like chemistry, engineering, biology and in daily life. Finally, we discuss the possible research perspectives in robust and durable liquid-repellent surfaces. By presenting such state-of-the-art of this significant and fast-developing area, we believe that this review will inspire multidisciplinary scientific communities and industrial circles to develop novel liquid-repellent surfaces that can meet the requirements of various real-world applications.


Asunto(s)
Agua , Interacciones Hidrofóbicas e Hidrofílicas , Propiedades de Superficie , Agua/química , Humectabilidad
7.
Sensors (Basel) ; 23(8)2023 Apr 18.
Artículo en Inglés | MEDLINE | ID: mdl-37112426

RESUMEN

AFM has a wide range of applications in nanostructure scanning imaging and fabrication. The wear of AFM probes has a significant impact on the accuracy of nanostructure measurement and fabrication, which is particularly significant in the process of nanomachining. Therefore, this paper focuses on the study of the wear state of monocrystalline silicon probes during nanomachination, in order to achieve rapid detection and accurate control of the probe wear state. In this paper, the wear tip radius, the wear volume, and the probe wear rate are used as the evaluation indexes of the probe wear state. The tip radius of the worn probe is detected by the nanoindentation Hertz model characterization method. The influence of single machining parameters, such as scratching distance, normal load, scratching speed, and initial tip radius, on probe wear is explored using the single factor experiment method, and the probe wear process is clearly divided according to the probe wear degree and the machining quality of the groove. Through response surface analysis, the comprehensive effect of various machining parameters on probe wear is determined, and the theoretical models of the probe wear state are established.

8.
J Microsc ; 287(1): 3-18, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-35411607

RESUMEN

Cancer is now responsible for the major leading cause of death worldwide. It is noteworthy that lung cancer has been recognised as the highest incidence (11.6%) and mortality (18.4%) for combined sexes among a variety of cancer diseases. Therefore, it is of great value to investigate the mechanical properties of lung cancerous cells for early diagnosis. This paper focus on the influence of measurement parameters on the measured central Young's moduli of single live A549 cell in vitro based on the force spectroscopy mode of atomic force microscopy (AFM). The effects of the measurement parameters on the measured central Young's moduli were analysed by fitting the force-depth curves utilising the Sneddon model. The results revealed that the Young's moduli of A549 cells increased with the larger indentation force, higher indentation speed, less retraction time, deeper Z length and lower purity percentage of serum. The Young's moduli of cells increased first and then decreased with the increasing dwell time. Hence, this research may have potential significance to provide reference for the standardised detection of a single cancerous cell in vitro using AFM methodologies.


Asunto(s)
Núcleo Celular , Módulo de Elasticidad , Microscopía de Fuerza Atómica/métodos
9.
Plant Cell Rep ; 41(8): 1631-1650, 2022 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-35575808

RESUMEN

Melatonin has attracted widespread attention after its discovery in higher plants. Tomato is a key model economic crop for studying fleshy fruits. Many studies have shown that melatonin plays important role in plant stress resistance, growth, and development. However, the research progress on the role of melatonin and related mechanisms in tomatoes have not been systematically summarized. This paper summarizes the detection methods and anabolism of melatonin in tomatoes, including (1) the role of melatonin in combating abiotic stresses, e.g., drought, heavy metals, pH, temperature, salt, salt and heat, cold and drought, peroxidation hydrogen and carbendazim, etc., (2) the role of melatonin in combating biotic stresses, such as tobacco mosaic virus and foodborne bacillus, and (3) the role of melatonin in tomato growth and development, such as fruit ripening, postharvest shelf life, leaf senescence and root development. In addition, the future research directions of melatonin in tomatoes are explored in combination with the role of melatonin in other plants. This review can provide a theoretical basis for enhancing the scientific understanding of the role of melatonin in tomatoes and the improved breeding of fruit crops.


Asunto(s)
Melatonina , Solanum lycopersicum , Sequías , Crecimiento y Desarrollo , Solanum lycopersicum/fisiología , Fitomejoramiento , Plantas , Estrés Fisiológico
10.
Soft Matter ; 17(19): 4989-4997, 2021 May 19.
Artículo en Inglés | MEDLINE | ID: mdl-33899836

RESUMEN

Micro-transfer printing is an effective method that enables the integration of micro-scale heterogeneous materials for flexible electronics. As the key component of micro-transfer printing equipment, the stamp is adopted to pick up and print microdevices due to its reversible and controllable adhesion. In this paper, we propose a novel microstructured stamp based on the bionic theory, which consists of a microchamber and four microchannels. A theoretical model about the pressure change of the gas in the microchamber is established and the effects of compression distance and pull-up velocity on the pull-off force of the stamp are investigated. The performance test results show that the pull-off force of the stamp can be controlled by both the compression distance and the pull-up velocity. Finally, micro-transfer printing operations of microdevices with different sizes, shapes and materials are realized based on the proposed microstructured stamp. The results show that the proposed microstructured stamp exhibits good performance in the transfer printing of microdevices, and provides a new way for the design of microstructured stamps for micro-transfer printing without an extra excitation system.

11.
Int J Mol Sci ; 22(21)2021 Oct 29.
Artículo en Inglés | MEDLINE | ID: mdl-34769214

RESUMEN

The tomato is a research model for fruit-ripening, however, its fruit-ripening mechanism still needs more extensive and in-depth exploration. Here, using TMT and LC-MS, the proteome and phosphoproteome of AC++ (wild type) and rin (ripening-inhibitor) mutant fruits were studied to investigate the translation and post-translational regulation mechanisms of tomato fruit-ripening. A total of 6141 proteins and 4011 phosphorylation sites contained quantitative information. One-hundred proteins were identified in both omics' profiles, which were mainly found in ethylene biosynthesis and signal transduction, photosynthesis regulation, carotenoid and flavonoid biosynthesis, chlorophyll degradation, ribosomal subunit expression changes, MAPK pathway, transcription factors and kinases. The affected protein levels were correlated with their corresponding gene transcript levels, such as NAC-NOR, MADS-RIN, IMA, TAGL1, MADS-MC and TDR4. Changes in the phosphorylation levels of NAC-NOR and IMA were involved in the regulation of tomato fruit-ripening. Although photosynthesis was inhibited, there were diverse primary and secondary metabolic pathways, such as glycolysis, fatty acid metabolism, vitamin metabolism and isoprenoid biosynthesis, regulated by phosphorylation. These data constitute a map of protein-protein phosphorylation in the regulation of tomato fruit-ripening, which lays the foundation for future in-depth study of the sophisticated molecular mechanisms of fruit-ripening and provide guidance for molecular breeding.


Asunto(s)
Frutas/metabolismo , Fosfoproteínas/metabolismo , Proteínas de Plantas/metabolismo , Solanum lycopersicum/metabolismo , Frutas/crecimiento & desarrollo , Solanum lycopersicum/crecimiento & desarrollo , Fosfoproteínas/análisis , Fosforilación , Proteínas de Plantas/análisis , Proteómica
12.
Langmuir ; 36(34): 10279-10292, 2020 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-32787017

RESUMEN

Stearic acid and fluoroalkylsilane are widely used in chemical modification to fabricate superhydrophobic surfaces in corrosion-resistant exploration. However, extensive works have just explored their anticorrosive performance in salt solution. Very rare work has focused on comparing their corrosion-resistant performance in corrosive solution (salt, alkali, and acid) systematically. In this study, two kinds of superhydrophobic surfaces were obtained on laser-processed rough IN304 surface after the stearic acid and FAS modification processes, respectively. The investigation and comparison of anticorrosion performance in salt, alkali, and acid electrolyte were carried out via potentiodynamic polarization and electrochemical impedance spectroscopy measurements. The promotion mechanism or impairing mechanism was further proposed based on the results of surface wettability, surface morphology, and X-ray photoelectron spectroscopy. Besides, the long-term anticorrosion performance and the stability of surface wettability were also investigated. It is hoped that these research findings could provide an explicit guidance of suitable anticorrosion methods selection for metals in different kinds of corrosive solution (salt, alkali, and acid), which will further raise the promising prospect of functional surfaces for practical applications in industry.

13.
Langmuir ; 35(52): 17027-17036, 2019 Dec 31.
Artículo en Inglés | MEDLINE | ID: mdl-31814410

RESUMEN

Extensive studies have been carried out to investigate the stability of superhydrophobic surfaces under acid, alkali, and salt solutions. It is noted that previous literature studies just demonstrated a variety of experimental phenomena. However, very few works have focused on the protection mechanism or failure mechanism of fluorinated superhydrophobic surfaces from the perspective of chemical aspects. Herein, this paper aims to investigate the effects of acid, alkali, and salt solutions on the stability of fluorinated superhydrophobic surfaces, and the anticorrosion/corrosion mechanism will be further proposed. The superhydrophobic coating was obtained on silicon substrates by laser surface texturing followed by fluoroalkyl silane modification. The resultant surfaces presented a water contact angle (WCA) of 157.6 ± 0.4° with a small water sliding angle (WSA) of 1.3 ± 0.3°. The newly fabricated superhydrophobic surfaces were then immersed in different concentrations of corrosive solutions (acid, alkali, and salt solutions). The revolution of surface wettability and surface morphology on treated silicon surfaces was evaluated through WCAs, scanning electron microscopy, and white light confocal microscopy. The results indicate that the hydrogen ions (H+) played a positive role in the retention of superhydrophobicity. However, the hydroxyl (OH-) and chloride ions (Cl-) presented the negative influence. The protection mechanism or corrosion mechanism under different solutions was proposed based on the X-ray photoelectron spectroscopy results. In addition, the potentiodynamic polarization and electrochemical impedance spectroscopy measurements provided strong support in data and were conducted to verify the rationality of the proposed mechanism.

14.
Int J Syst Evol Microbiol ; 69(1): 123-128, 2019 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-30431420

RESUMEN

A novel Gram-stain-negative, motile and rod-shaped bacterium, designated xg18T, was isolated from Lake XuguoCo on the Tibetan Plateau. The strain was able to grow optimally at 0-2 % NaCl and tolerate up to 6 % NaCl. Growth occurred at pH 7.0-11.0 (optimum, pH 9.0-10.0) and 15-40 °C (optimum, 37 °C). Vitamins were not required for growth. The major polar lipids of strain xg18T were phosphatidyl ethanolamine and phosphatidylglycerol. The predominant respiratory quinone was Q-8. The major fatty acids were summed feature 8 (C18 : 1ω6c and/or C18 : 1ω7c), summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) and C16 : 0. The G+C content of genomic DNA was 46.1 mol%. Analysis of 16S rRNA sequences showed that strain xg18T belongs to the genus Nitrincola, with Nitrincola alkalisediminis MEB087T (KC822363, 98.6 %) as its closest neighbour. The DNA-DNA relatedness value of strain xg18T with its closest phylogenetic neighbour, N. alkalisediminis JCM 19317T, was 43.1±3.2 %. Strain xg18T was clearly distinguishable from the type strain of the genus Nitrincola through phylogenetic analysis, fatty acid composition data and a range of physiological and biochemical characteristics comparisons. Based on its phenotypic and chemotaxonomic characteristics, strain xg18T could be classified as a representative of a novel species of the genus for which the name Nitrincola tibetensis sp. nov. is proposed. The type strain is xg18T (=CICC 24457T=KCTC 62401T).


Asunto(s)
Lagos/microbiología , Oceanospirillaceae/clasificación , Filogenia , Técnicas de Tipificación Bacteriana , Composición de Base , ADN Bacteriano/genética , Ácidos Grasos/química , Hibridación de Ácido Nucleico , Oceanospirillaceae/aislamiento & purificación , Fosfolípidos/química , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Tibet , Ubiquinona/química
15.
Int J Syst Evol Microbiol ; 69(1): 165-170, 2019 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-30457510

RESUMEN

A novel, Gram-stain-negative, non-motile and rod-shaped bacterium, designated YH5T, was isolated from the YonghuCo wetland on the Tibetan Plateau. The strain was able to grow optimally with 1 % (w/v) NaCl and tolerated up to 3 % NaCl. Growth occurred at pH 6-9 (optimum pH 7) and 10-37 °C (optimum 30 °C). Vitamins were not required for growth. The major polar lipid of strain YH5T was phosphatidylethanolamine. The predominant respiratory quinone was menaquinone 6 (MK-6). The major fatty acids were iso-C15 : 0, C16 : 0 10-methyl and/or iso-C17 : 1ω9c, iso-C17 : 0 3-OH, iso-C15 : 1 G and iso-C15 : 0 3-OH. Genome sequencing revealed a genome size of 2.74 Mbp and a G+C content of 33.3 mol%. Analysis of 16S rRNA gene sequences showed that strain YH5T belonged to the genus Flavobacterium, with the closest neighbours Flavobacterium luticocti xz20T (96.7 % similarity), Flavobacterium jejuense EC11T (96.4 %), Flavobacterium jumunjinense HME7102T (95.9 %) and Flavobacterium dongtanense LW30T (95.6 %). DNA-DNA relatedness between strain YH5T and the closest phylogenetically related strain F. luticocti xz20T was 27.0 %. Strain YH5T was clearly distinguished from the reference type strains based on phylogenetic analysis, DNA-DNA hybridization, fatty acid composition and a range of physiological and biochemical characteristics. Based on its phenotypic and chemotaxonomic characteristics, strain YH5T is classified as a representative of a novel species of the genus Flavobacterium, for which the name Flavobacterium tibetense sp. nov. is proposed. The type strain is YH5T (=CICC 24247T=KCTC 62174T).


Asunto(s)
Flavobacterium/clasificación , Filogenia , Humedales , Técnicas de Tipificación Bacteriana , Composición de Base , ADN Bacteriano/genética , Ácidos Grasos/química , Flavobacterium/aislamiento & purificación , Hibridación de Ácido Nucleico , Fosfatidiletanolaminas/química , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Tibet , Vitamina K 2/análogos & derivados , Vitamina K 2/química
16.
J Colloid Interface Sci ; 658: 61-73, 2024 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-38100977

RESUMEN

HYPOTHESIS: The solid fraction of the substrate is expected to influence the bouncing behavior of an impinging droplet, thereby affecting spreading and contact time. Hence, it should be possible to alter the velocity and pressure distribution of impacting droplet, and also affect the impact velocity for droplet penetration right upon impact. SIMULATIONS: We systematically investigate the impact dynamics of water droplets on pillared hydrophobic surfaces with different solid fractions using phase-field simulations. The velocity and pressure distributions of impacting droplets on pillared hydrophobic surfaces with varied Weber numbers and solid fractions are studied. In addition, the influences of the solid fraction on the bouncing behaviors of the impinging droplet, such as the maximum wetting spreading, the maximum impacting depth, and the contact time, are also investigated to further understand the impact event. FINDINGS: We show that a three-peak pressure profile appears on the top of the pillared hydrophobic surface during droplet impact by varying the solid fraction of the surface. The first peak is generated by the impact of the droplet itself, while the second peak arises from the droplet recoil impact associated with the dynamic properties of the jet. Moreover, we identify a hitherto unknown third pressure peak related to the hydrodynamic singularity that emerges due to the convergence of the fluid during the droplet rebound. This solid fraction-dependent impacting behavior reveals the intricate interplay between droplet dynamics and the underlying surface characteristics, providing valuable insights into the design and optimization of micro/nano structured hydrophobic surfaces for various applications.

17.
Front Plant Sci ; 15: 1336300, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38313806

RESUMEN

Introduction: Straw return has been widely recognized as an important carbon (C) enhancement measure in agroecosystems, but the C-phosphorus (P) interactions and their effects on plants in saline soils are still unclear. Methods: In this study, we investigated the effects of straw return and three P application levels, no P fertilizer (Non-P), a conventional application rate of P fertilizer (CP), and a high application rate of P fertilizer (HP), on maize growth and soil C and P fractions through a pot experiment. Results and discussion: The results revealed that the dry matter weight of maize plant was no difference between the two straw return levels and was 15.36% higher under HP treatments than under Non-P treatments. Plant nutrient accumulations were enhanced by straw addition and increased with increasing P application rate. Straw application reduced the activities of peroxidase (POD), superoxide dismutase (SOD), catalase, and the content of malondialdehyde (MDA) in maize plants by 31.69%, 38.99%, 45.96% and 27.04%, respectively. P application decreased SOD, POD activities and MDA content in the absence of straw. The contents of easily oxidized organic carbon (EOC), particulate organic carbon (POC) and the ratio of POC/SOC in straw-added soils were 10.23%, 17.00% and 7.27% higher, respectively, than those in straw-absent soils. Compared with Non-P treatments, HP treatments led to an increase of 12.05%, 23.04% in EOC, POC contents respectively, while a decrease of 18.12% in the contribution of MAOC to the SOC pool. Straw return improved the P status of the saline soil by increasing soil available P (14.80%), organic P (35.91%) and Ca2-P contents (4.68%). The structural equation model showed that straw and P applications could promote maize growth (indicated by dry matter weight, P accumulation, antioxidant enzyme activity and MDA content) through improving soil C and P availabilities. Conclusion: This study provides evidence that straw return together with adequate P supply in saline soil can promote crop nutrient accumulation, attenuate the oxidation damage on crop growth, and be beneficial for SOC turnover and soil P activation.

18.
Artículo en Inglés | MEDLINE | ID: mdl-38963398

RESUMEN

Here, we explored a new manufacturing strategy that uses the mask laser interference additive manufacturing (MLIAM) technique, which combines the respective strengths of laser interference lithography and mask lithography to efficiently fabricate across-scales three-dimensional bionic shark skin structures with superhydrophobicity and adhesive reduction. The phenomena and mechanisms of the MLIAM curing process were revealed and analyzed, showing the feasibility and flexibility. In terms of structural performance, the adhesive force on the surface can be tuned based on the growth direction of the bionic shark skin structures, where the maximum rate of the adhesive reduction reaches about 65%. Furthermore, the evolution of the directional diffusion for the water droplet, which is based on the change of the contact angle, was clearly observed, and the mechanism was also discussed by the models. Moreover, no-loss transportations were achieved successfully using the gradient adhesive force and superhydrophobicity on the surface by tuning the growth direction and modifying by fluorinated silane. Finally, this work gives a strategy for fabricating across-scale structures on micro- and nanometers, which have potential application in bioengineering, diversional targeting, and condenser surface.

19.
J Mech Behav Biomed Mater ; 128: 105097, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-35151180

RESUMEN

Although cellular elastic property (CEP, also known as cellular elastic modulus) has been frequently reported as a biomarker to distinguish some cancerous cells from their benign counterparts, it cannot be adopted as a universal hallmark to be applied to every kind cell. In the present study, we report that insignificant difference is observed between normal gastric cell and its cancer counterpart which is one of the common human malignancies, in terms of CEP statistical distribution. In this regard, we propose multiple cellular mechanical phenotypes (CMPs) to differentiate the above two cell types, which is realized by machine learning algorithm (MLA). The results show that the cellular classification effect proves better with more CMPs adopted, regardless of the exact MLA employed. Moreover, the MLA-based method remains effective if we add two more cell lines to the above two cell categories. Our study indicates that MLA-based cellular classification can potentially serve as an efficient and objective means to assist or even validate cancer prognostics.


Asunto(s)
Aprendizaje Automático , Neoplasias , Algoritmos , Humanos , Fenotipo , Pronóstico
20.
Anal Methods ; 13(28): 3136-3146, 2021 07 28.
Artículo en Inglés | MEDLINE | ID: mdl-34156056

RESUMEN

Cancer is currently drawing more and more attention as the leading factor in death worldwide. However, little research has been directed towards investigating the micro/nanoscale mechanical properties of cancer cells treated by targeted drugs to evaluate the model systems of targeted drugs using atomic force microscopy (AFM) nano-indentation, especially in light of the multiple drugs targeting various cancerous cells. This paper aims to compare the mechanical effects of sorafenib tosylate and osimertinib mesylate on hepatoma carcinoma cells and lung cancerous cells using atomic force microscopy from the perspective of a model system based on nano-indentation at the micro/nanoscale, which has rarely been investigated. The Sneddon model is applied to fit the force-distance curves, and the mechanical properties, i.e., Young's moduli, can then be calculated. For the SMMC-7721 cells, osimertinib mesylate is a more effective inhibitor than sorafenib tosylate. For the A549 cells, osimertinib mesylate and sorafenib tosylate both have an obvious inhibitory effect. The experimental results may make possible contributions to the diagnosis and treatment of early-stage cancers.


Asunto(s)
Fenómenos Mecánicos , Preparaciones Farmacéuticas , Línea Celular , Módulo de Elasticidad , Humanos , Microscopía de Fuerza Atómica
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