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1.
Development ; 150(2)2023 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-36628974

RESUMO

Src kinases are important regulators of cell adhesion. Here, we have explored the function of Src42A in junction remodelling during Drosophila gastrulation. Src42A is required for tyrosine phosphorylation at bicellular (bAJ) and tricellular (tAJ) junctions in germband cells, and localizes to hotspots of mechanical tension. The role of Src42A was investigated using maternal RNAi and CRISPR-Cas9-induced germline mosaics. We find that, during cell intercalations, Src42A is required for the contraction of junctions at anterior-posterior cell interfaces. The planar polarity of E-cadherin is compromised and E-cadherin accumulates at tricellular junctions after Src42A knockdown. Furthermore, we show that Src42A acts in concert with Abl kinase, which has also been implicated in cell intercalations. Our data suggest that Src42A is involved in two related processes: in addition to establishing tension generated by the planar polarity of MyoII, it may also act as a signalling factor at tAJs to control E-cadherin residence time.


Assuntos
Proteínas de Drosophila , Drosophila , Animais , Junções Aderentes/metabolismo , Caderinas/genética , Caderinas/metabolismo , Drosophila/metabolismo , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Junções Intercelulares/metabolismo , Proteínas Proto-Oncogênicas pp60(c-src)/genética , Proteínas Proto-Oncogênicas pp60(c-src)/metabolismo , Quinases da Família src/genética , Quinases da Família src/metabolismo
2.
Opt Express ; 31(14): 23040-23055, 2023 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-37475398

RESUMO

Metal cylindrical shaft parts are critical components in industrial manufacturing that require high standards for roundness error and surface roughness. When using the self-developed multi-beam angle sensor (MBAS) to detect metal cylindrical shaft parts, the distorted multi-spots degrade the measurement accuracy due to the nonlinear distortion caused by the metal material's reflective properties and surface roughness. In this study, we propose a spot coordinate prediction network (SCPNet), which is a deep-learning neural network designed to predict spot coordinates, in combination with Hough circle detection for localization. The singular value decomposition (SVD) model is employed to eliminate the tilt error to achieve high-precision, three-dimensional (3D) surface reconstruction of metal cylindrical shaft parts. The experimental results demonstrate that SCPNet can effectively correct distorted multi-spots, with an average error of the spot center of 0.0612 pixels for ten points. The proposed method was employed to measure metal cylindrical shaft parts with radii of 10 mm, 20 mm, 35 mm, and 50 mm, with resulting standard deviation (STD) values of 0.0022 µm, 0.0026 µm, 0.0028 µm, and 0.0036 µm, respectively.

3.
Opt Express ; 31(4): 5593-5608, 2023 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-36823835

RESUMO

To solve limited efficiency and reliability issues caused by current manual quality control processes in optical lens (OL) production environments, we propose an automatic micro vision-based inspection system named MVIS used to capture the surface defect images and make the OL dataset and predictive inference. Because of low resolution and recognition, OL defects are weak, due to their ambiguous morphology and micro size, making a poor detection effect for the existing method. A deep-learning algorithm for a weak micro-defect detector named ISE-YOLO is proposed, making the best for deep layers, utilizing the ISE attention mechanism module in the neck, and introducing a novel class loss function to extract richer semantics from convolution layers and learning more information. Experimental results on the OL dataset show that ISE-YOLO demonstrates a better performance, with the mean average precision, recall, and F1 score increasing by 3.62%, 6.12% and 3.07% respectively, compared to the YOLOv5. In addition, compared with YOLOv7, which is the latest version of YOLO serials, the mean average precision of ISE-YOLO is improved by 2.58%, the weight size is decreased by more than 30% and the speed is increased by 16%.

4.
Chemistry ; 29(33): e202300552, 2023 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-36995358

RESUMO

Inspired by alkene addition to the Ru and Re tris(thiolate) complexes via carbon-sulfur bond formation/cleavage reactions along with a periodic extension catalysis notion, a comparative study of the electronic structures, mechanisms, and reactivities for ethylene addition to the Os and Tc tris(thiolate) complexes was performed by DFT and high-level ab initio quantum calculations. The oxidized Os and Tc complexes were revealed to exhibit sufficient radical characters on the ligands to support their reaction with ethylene, whereas neutral Tc tris(thiolate) complex featuring little thiyl radical character renders no reactivity toward ethylene. Differential reactivities of these tris(thiolate) complexes was deemed to derive from the synergy of the thiyl radical character, the electronegativity, the row, and the charge. Extending from Ru and Re tris(thiolate) complexes to their Os and Tc counterparts can help us to get insightful rationales that would promote further research on alkene addition to metal-stabilized thiyl radicals.


Assuntos
Alcenos , Metais , Ligantes , Etilenos
5.
Sensors (Basel) ; 22(10)2022 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-35632084

RESUMO

It is important to monitor the take-off and landing of civil aircraft using passive detection methods. Due to the strict aircraft safety requirements and the electromagnetic environment around an airport, using too many active detection methods should be avoided. Using an aircraft's microwave radiation signal detection is very advantageous because it does not actively emit signals and has a strong cloud penetration, suitable for all-weather observation. This paper introduces a synthetic aperture microwave radiation system for monitoring the take-off and landing of civil aircraft, which is characterized by real-time two-dimensional imaging, and the image refresh rate can reach 10 ms, which meets the high refresh rate requirements for aircraft imaging. Applicable system parameters and antenna array distribution scheme and imaging algorithm are given. Then the paper focuses on the error analysis and correction method of the system. The correction method is simple and fast, which avoids the disadvantage that the error needs to be corrected regularly in the laboratory environment, and is suitable for airport application. Finally, the simulation and experimental results show that this technology can be used for real-time monitoring of civil aircraft during take-off and landing, and it is a practical means to assisting landing.

6.
Opt Express ; 29(22): 36720-36733, 2021 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-34809076

RESUMO

Designing diffractive waveguides for head-mounted displays requires wide-angle conical diffraction analysis of multiple gratings. In this work, diffractive waveguide design using the relative direction cosine space, which extends the direction cosine space to a relative space involving refractive indices and can describe grating diffraction through various media, is demonstrated. A diffractive waveguide was fabricated with grating periods of 382 and 270 nm, which generated a monochromatic virtual image image in green light (520 nm). The maximum field of view was measured as 39° with 0.5° deviation from the center of view.

7.
EMBO Rep ; 20(12): e47755, 2019 12 05.
Artigo em Inglês | MEDLINE | ID: mdl-31663248

RESUMO

The spatial and temporal dynamics of cell contractility plays a key role in tissue morphogenesis, wound healing, and cancer invasion. Here, we report a simple optochemical method to induce cell contractions in vivo during Drosophila morphogenesis at single-cell resolution. We employed the photolabile Ca2+ chelator o-nitrophenyl EGTA to induce bursts of intracellular free Ca2+ by laser photolysis in the epithelial tissue. Ca2+ bursts appear within seconds and are restricted to individual target cells. Cell contraction reliably followed within a minute, causing an approximately 50% drop in the cross-sectional area. Increased Ca2+ levels are reversible, and the target cells further participated in tissue morphogenesis. Depending on Rho kinase (ROCK) activity but not RhoGEF2, cell contractions are paralleled with non-muscle myosin II accumulation in the apico-medial cortex, indicating that Ca2+ bursts trigger non-muscle myosin II activation. Our approach can be, in principle, adapted to many experimental systems and species, as no specific genetic elements are required.


Assuntos
Drosophila melanogaster/citologia , Células Epiteliais/fisiologia , Animais , Animais Geneticamente Modificados , Fenômenos Biomecânicos , Quelantes de Cálcio/farmacologia , Sinalização do Cálcio/efeitos dos fármacos , Sinalização do Cálcio/fisiologia , Forma Celular/efeitos dos fármacos , Forma Celular/fisiologia , Proteínas de Drosophila/fisiologia , Drosophila melanogaster/genética , Drosophila melanogaster/fisiologia , Ácido Egtázico/análogos & derivados , Ácido Egtázico/farmacologia , Células Epiteliais/citologia , Células Epiteliais/efeitos dos fármacos , Feminino , Miosina Tipo II/fisiologia , Processos Fotoquímicos , Análise de Célula Única , Análise Espaço-Temporal
8.
J Acoust Soc Am ; 150(2): 1157, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34470274

RESUMO

Acoustic underwater propulsion systems based on bulk acoustic waves and surface acoustic waves have been studied. In this study, an acoustic propulsion system that consists of a 2.065-MHz thickness-vibration-mode lead-zirconate-titanate ultrasonic transducer is evaluated. A prototype swimmer is designed and fabricated. The admittance difference of the transducer in water and air is investigated. The vibration amplitude of the transducer is measured to evaluate transducer performance. The acoustic radiation force is calculated to describe acoustic propulsion. The zero-speed propulsion (ZSP) force and no-load speed (NLS) are measured in water. Swimmer movement starts at a NLS of 6.1 mm/s and a ZSP force of 0.2 mN for an input voltage and input power of 12.4 V peak to peak and 0.4 W, respectively. Although the average efficiency of the acoustic propulsion system is 69% in water, the overall movement efficiency of the swimmer is less than 1% because of fluid resistance and wire traction. Based on admittance, acoustic propulsion calculations, ZSP force, NLS measurements, and efficiency analysis, an evaluation method is proposed for optimizing swimmers with an acoustic underwater propulsion system. Small size, high power density, and simple structure of an acoustic propulsion system with an ultrasonic transducer make such systems suitable for applications such as pipeline inspection and repair.

9.
Biophys J ; 113(12): 2601-2608, 2017 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-29129266

RESUMO

Epithelial cells are responsible for tissue homeostasis and form a barrier to maintain chemical gradients and mechanical integrity. Therefore, rapid wound closure is crucial for proper tissue function and restoring homeostasis. In this study, the mechanical properties of cells surrounding a single-cell wound are investigated during closure of the defect. The single-cell wound is induced in an intact layer using micropipette action and responses in neighboring cells are monitored with atomic force microscopy. Direct neighbors reveal a rise in the apparent pretension, which is dominated by cortical tension. The same effect was observed for a single-cell wound induced by laser ablation and during closure of a not fully confluent layer. Moreover, changes in the apparent pretension are far reaching and persist even in cells separated by three cell widths from the defect. This shows that epithelial cells respond to minimal wounds in a collective fashion by increased contractility with substantial reach.


Assuntos
Células Epiteliais/citologia , Fenômenos Mecânicos , Análise de Célula Única , Animais , Fenômenos Biomecânicos , Cães , Células Madin Darby de Rim Canino
10.
Biophys J ; 113(12): 2796-2804, 2017 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-29262372

RESUMO

Proprioception is an integral part of the feedback circuit that is essential for locomotion control in all animals. Chordotonal organs perform proprioceptive and other mechanosensory functions in insects and crustaceans. The mechanical properties of these organs are believed to be adapted to the sensory functions, but had not been probed directly. We measured mechanical properties of a particular chordotonal organ-the lateral pentascolopidial (lch5) organ of Drosophila larvae-which plays a key role in proprioceptive locomotion control. We applied tension to the whole organ in situ by transverse deflection. Upon release of force, the organ displayed overdamped relaxation with two widely separated time constants, tens of milliseconds and seconds, respectively. When the muscles covering the lch5 organ were excised, the slow relaxation was absent, and the fast relaxation became faster. Interestingly, most of the strain in the stretched organ is localized in the cap cells, which account for two-thirds of the length of the entire organ, and could be stretched by ∼10% without apparent damage. In laser ablation experiments we found that cap cells retracted by ∼100 µm after being severed from the neurons, indicating considerable steady-state stress and strain in these cells. Given the fact that actin as well as myosin motors are abundant in cap cells, the results point to a mechanical regulatory role of the cap cells in the lch5 organ.


Assuntos
Drosophila melanogaster , Larva , Fenômenos Mecânicos , Animais , Fenômenos Biomecânicos , Elasticidade , Lasers
11.
Dev Biol ; 390(2): 208-20, 2014 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-24681004

RESUMO

The majority of membrane and secreted proteins, including many developmentally important signalling proteins, receptors and adhesion molecules, are cotranslationally N-glycosylated in the endoplasmic reticulum. The structure of the N-glycan is invariant for all substrates and conserved in eukaryotes. Correspondingly, the enzymes are conserved, which successively assemble the glycan precursor from activated monosaccharides prior to transfer to nascent proteins. Despite the well-defined biochemistry, the physiological and developmental role of N-glycosylation and of the responsible enzymes has not been much investigated in metazoa. We identified a mutation in the Drosophila gene, xiantuan (xit, CG4542), which encodes one of the conserved enzymes involved in addition of the terminal glucose residues to the glycan precursor. xit is required for timely apical constriction of mesoderm precursor cells and ventral furrow formation in early embryogenesis. Furthermore, cell intercalation in the lateral epidermis during germband extension is impaired in xit mutants. xit affects glycosylation and intracellular distribution of E-Cadherin, albeit not the total amount of E-Cadherin protein. As depletion of E-Cadherin by RNAi induces a similar cell intercalation defect, E-Cadherin may be the major xit target that is functionally relevant for germband extension.


Assuntos
Caderinas/metabolismo , Proteínas de Drosophila/metabolismo , Drosophila/embriologia , Retículo Endoplasmático/metabolismo , Gastrulação/fisiologia , Regulação da Expressão Gênica/fisiologia , Glucosiltransferases/metabolismo , Movimento/fisiologia , Junções Aderentes/fisiologia , Animais , Sequência de Bases , Western Blotting , Drosophila/enzimologia , Proteínas de Drosophila/genética , Fluorescência , Componentes do Gene , Regulação da Expressão Gênica/genética , Glucosiltransferases/genética , Microscopia Confocal , Dados de Sequência Molecular , Interferência de RNA , Análise de Sequência de DNA
12.
Opt Express ; 23(15): 19082-91, 2015 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-26367571

RESUMO

We numerically analyzed the power-coupling characteristics between a high-index-contrast dielectric slot waveguide and a metal-insulator-metal (MIM) plasmonic slot waveguide as functions of structural parameters. Couplings due mainly to the transfer of evanescent components in two waveguides generated high transmission efficiencies of 62% when the slot widths of the two waveguides were the same and 73% when the waveguides were optimized by slightly different widths. The maximum transmission efficiency in the slot-to-slot coupling was about 10% higher than that in the coupling between a normal slab waveguide and an MIM waveguide. Large alignment tolerance of the slot-to-slot coupling was also proved. Moreover, a small gap inserted into the interface between two waveguides effectively enhances the transmission efficiency, as in the case of couplings between a normal slab waveguide and an MIM waveguide. In addition, couplings with very wideband transmissions over a wavelength region of a few hundred nanometers were validated.

13.
Opt Express ; 23(3): 1981-91, 2015 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-25836069

RESUMO

In this study, we present a new design for an optical near-field probe with a slot-waveguide structure and evaluate it using a finite-difference time-domain simulation. Our model, with a 50-nm slot core, enables illumination around the tip of the probe using a small optical spot 50-250 nm wide with 20%-30% transmission efficiency. Based on the high-index-contrast structure in a slot waveguide, a nanosized optical spot is easily generated, which is impossible with a normal slab waveguide. Similar properties of optical spot and transmission efficiency are obtained for different geometric configurations of flat-faced and tapered dielectric slot waveguides in illumination mode. The transmission efficiency of our models is the same or higher than that in conventional metallic tapered optical probes. When operating in illumination and collection modes, a near-field light reflected at 50-200-nm-wide measured objects is clearly observed, and a spatial resolution of ~50 nm is obtained. These findings suggest the potential for slot-waveguide structures to expand the versatility of nanosized optical probes.

14.
Front Vet Sci ; 11: 1382897, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38756519

RESUMO

Sheep body size can directly reflect the growth rates and fattening rates of sheep and is also an important index for measuring the growth performance of meat sheep. In this study, high-resolution resequencing data from four sheep breeds (Dorper sheep, Suffolk sheep, Ouessant sheep, and Shetland sheep) were analyzed. The nonsynonymous single nucleotide polymorphisms of three candidate genes (KIAA1217, SNTA1, and LTBP1) were also genotyped in 642 healthy Ujumqin sheep using MALDI-TOFMS and the genotyping results were associated with growth traits. The results showed that different genotypes of the KIAA1217 g.24429511T>C locus had significant effects on the chest circumferences of Ujumqin sheep. The SNTA1 g.62222626C>A locus had different effects on the chest depths, shoulder widths and rump widths of Ujumqin sheep. This study showed that these two sites can be used for marker-assisted selection, which will be beneficial for future precision molecular breeding.

15.
Ultrasonics ; 129: 106910, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36512990

RESUMO

Ultrasonic motors (USMs) are expected to be used in special environments: high magnetic field environments and space environments, which require lightweight and multiple degrees of freedom. However, when used as linear ultrasonic motors (LUSMs), a linear guide and a preload mechanism are required, complicating the structure. In the present paper, a hollow cylindrical linear stator without an extra linear guide has been considered. The stator consists of a metal pipe and two piezoelectric (PZT) tubes installed at both ends of the metal pipe. Their connected parts are tapered for the first longitudinal axisymmetric vibration mode of the cylinder, namely L(0,1) mode excitation, and the metal pipe is subjected to radial strain. The vibration of the stator is assumed to be one-dimensional and is modeled by an electromechanical equivalent circuit. The principle that the traveling wave is formed on the metal pipe by dual-PZT-tube phase difference excitation was clarified. Finite element analysis and some measurements were conducted to confirm that the theory was consistent. The analyses and measurements were in good agreement. Therefore, the operating principle was confirmed. The results of the transport experiment showed that the average speed of the 8.5-g slider was 7.9 mm/s.


Assuntos
Transdutores , Vibração , Desenho de Equipamento , Ultrassom , Análise de Elementos Finitos
16.
Curr Biol ; 33(16): R873-R875, 2023 08 21.
Artigo em Inglês | MEDLINE | ID: mdl-37607486

RESUMO

Rods under mechanical stress are a classic example of dynamic instability. Axis elongation in Drosophila usually leads to a U-shaped axis, but folded or twisted axes are observed in certain mutants. Analysis of these mutants now reveals the source of the instability and the mechanism for maintaining left-right symmetry.


Assuntos
Drosophila , Células Fotorreceptoras Retinianas Bastonetes , Animais , Drosophila/genética , Morfogênese/genética , Estresse Mecânico
17.
Mar Life Sci Technol ; 5(4): 585-601, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-38045551

RESUMO

Cell-cell adhesion is at the center of structure and dynamics of epithelial tissue. E-cadherin-catenin complexes mediate Ca2+-dependent trans-homodimerization and constitute the kernel of adherens junctions. Beyond the basic function of cell-cell adhesion, recent progress sheds light the dynamics and interwind interactions of individual E-cadherin-catenin complex with E-cadherin superclusters, contractile actomyosin and mechanics of the cortex and adhesion. The nanoscale architecture of E-cadherin complexes together with cis-interactions and interactions with cortical actomyosin adjust to junctional tension and mechano-transduction by reinforcement or weakening of specific features of the interactions. Although post-translational modifications such as phosphorylation and glycosylation have been implicated, their role for specific aspects of in E-cadherin function has remained unclear. Here, we provide an overview of the E-cadherin complex in epithelial cell and tissue morphogenesis focusing on nanoscale architectures by super-resolution approaches and post-translational modifications from recent, in particular in vivo, studies. Furthermore, we review the computational modelling in E-cadherin complexes and highlight how computational modelling has contributed to a deeper understanding of the E-cadherin complexes.

18.
bioRxiv ; 2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36909597

RESUMO

During embryonic development dramatic cell shape changes and movements re-shape the embryonic body plan. These require robust but dynamic linkage between the cell-cell adherens junctions and the force-generating actomyosin cytoskeleton. Our view of this linkage has evolved, and we now realize linkage is mediated by a mechanosensitive multiprotein complex assembled via multivalent connections. Here we combine genetic, cell biological and modeling approaches to define the mechanism of action and functions of an important player, Drosophila Polychaetoid, homolog of mammalian ZO-1. Our data reveal that Pyd reinforces cell junctions under elevated tension, and facilitates cell rearrangements. Pyd is important to maintain junctional contractility and in its absence cell rearrangements stall. We next use structured illumination microscopy to define the molecular architecture of cell-cell junctions during these events. The cadherin-catenin complex and Cno both localize to puncta along the junctional membrane, but are differentially enriched in different puncta. Pyd, in contrast, exhibits a distinct localization to strands that extend out from the region occupied by core junction proteins. We then discuss the implications for the protein network at the junction-cytoskeletal interface, suggesting different proteins localize and function in distinct ways but combine to produce robust connections.

19.
Mol Biol Cell ; 34(8): ar81, 2023 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-37163320

RESUMO

During embryonic development, dramatic cell shape changes and movements reshape the embryonic body plan. These require robust but dynamic linkage between the cell-cell adherens junctions and the force-generating actomyosin cytoskeleton. Our view of this linkage has evolved, and we now realize linkage is mediated by mechanosensitive multiprotein complexes assembled via multivalent connections. Here we combine genetic, cell biological, and modeling approaches to define the mechanism of action and functions of an important player, Drosophila polychaetoid, homologue of mammalian ZO-1. Our data reveal that Pyd reinforces cell junctions under elevated tension, and facilitates cell rearrangements. Pyd is important to maintain junctional contractility and in its absence cell rearrangements stall. We next use structured illumination microscopy to define the molecular architecture of cell-cell junctions during these events. The cadherin-catenin complex and Cno both localize to puncta along the junctional membrane, but are differentially enriched in different puncta. Pyd, in contrast, exhibits a distinct localization to strands that extend out from the region occupied by core junction proteins. We then discuss the implications for the protein network at the junction-cytoskeletal interface, suggesting different proteins localize and function in distinct ways, perhaps in distinct subcomplexes, but combine to produce robust connections.


Assuntos
Junções Aderentes , Proteínas de Drosophila , Animais , Citoesqueleto de Actina/metabolismo , Junções Aderentes/metabolismo , Caderinas/metabolismo , Citoesqueleto/metabolismo , Drosophila/metabolismo , Drosophila melanogaster/metabolismo , Proteínas de Drosophila/metabolismo , Mamíferos/metabolismo , Junções Íntimas/metabolismo
20.
Methods Mol Biol ; 2540: 285-299, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35980584

RESUMO

Cell shape changes based on actomyosin contractility provide a driving force in tissue morphogenesis. The temporally and spatially coordinated constrictions of many cells result in changes in tissue morphology. Given the networks of complex and mutual cellular interactions, the mechanisms underlying the emergence in tissue behavior are challenging to pinpoint. Important in the analysis of such interactions are novel methods for noninvasive interference with single-cell resolution and sub-minute timescale temporal control. Here we characterize an optochemical approach of Ca2+ uncaging to control cell contractility in Drosophila embryos. We describe in detail the method of sample preparation, microinjection, Ca2+ uncaging, and data analysis.


Assuntos
Proteínas de Drosophila , Drosophila , Actomiosina , Animais , Forma Celular , Morfogênese
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