Banana mechanical crown cutting tool which is a critical component of banana crown cutting machine is designed and studied in this paper. Experiments were designed to optimize parameters of the cutting tool. Indexes are cut surface quality grade of banana crown, maximum cutting force and useful power consumption. For banana preservation, get high grade of cut surface quality is more significant than consume less energy. Results of experiments show that the optimum parameters are as follows: cutting speed is about 50–60 mm/s, number of cut sets are about 4–6, angle between thick cutter and axis of banana rachis is about 5°, width of thick cutter is about 8–14 mm, thickness of thick cutter is about 2–3 mm, edge angle of thick cutter is between 20° and 30°, width of thin cutter is about 10–14 mm and thickness of thin cutter is about 0.2–0.4mm. This study helps to make the completely mechanical postharvest treatments for banana postharvest treatments. According to FAO data, the global banana production was 66.0 million tons in 2000, 106.0 million tons in 2013, 106.2 million tons in 2014, and 117 million tons in 2019.Among the banana growing countries / regions in the world, India ranks first in annual output, accounting for about 26.08% of the world’s banana output; China ranks second, accounting for about 10.27% of the world’s banana production [Bananas are the food for people to survive, so bananas are also recognized as the fourth largest food crop in the world. At this stage, banana harvesting is dominated by manual labor, with a low degree of mechanization, especially in the banana combing link, there is no mechanical processing equipment, relying on manual processing, the mechanical chain of harvesting and processing is incomplete, and it is impossible to achieve full automation. Therefore, it is of practical significance and theoretical value to carry out research on key technologies and devices of banana mechanical combing.The authors have studied non-destructive transportation of banana harvest –5, and tBanana mechanical combing device refers to a comprehensive banana combing machine that includes a clamping mechanism, a lifting mechanism, a combing mechanism and a transporting mechanism, prototype model of the banana crown cutting tool is designed for both efficiency and cost effectiveness.It is mainly composed of 17 devices such as rough cutter, guide rod cylinder, cylinder bracket and so on.The mechanical structure of banana crown cutting tool by combined cutters way is shown in The cutters can move up and down along the axis controlled by the stepper motor controller. The combined cutters encircles the banana rachis controlled by the guide rod cylinder.The importance parameters of the cutters consist of cutting speed, number of cut sets, angle between thick cutter and axis of banana rachis, width of thick cutter, thickness of thick cutter, edge angle of thick cutter, width of thin cutter and thickness of thin cutter.Free-body diagram of cutter cutting banana crown is shown in Fx is cutting force in x direction, Fy is cutting force in y direction, P is the cutter edge resistance, Na and Nb are Normal loads, Fa and Fb are frictional forces, f is friction coefficient.The equations are expressed by:Forty bunches of mature green bananas  from Machong Farm, Dongguan City, Guangdong province, China, were harvested on July, from 2014 to 2021. The farm is at 23°2’24" degrees north latitude and 113°34’48" degrees east longitude. The ripening stage of banana is green . ApproprAn test device was designed to optimize the main parameters of the banana crown cutting tool. The main characteristics of the device are detailed in The experiments took place in laboratory of the South China Agricultural University . The banThe indexes are maximum cutting force, useful power consumption and cut surface quality.Typical curve of cutting force performed by factors on level 3 is shown in During the cutting process, if the banana peel is damaged, the banana finger separated from banana hand by the cutter, the cut surface quality grade will be very bad for banana preservation, so these cut surface of banana crown is very bad and be graded 60–69 .If there is no skin from the rachis be cut off and banana fingers not separated from banana hand by the cutter, but the cut surface have some rough edges and very nearer to banana stalk, the cut surface quality grade is also bad for banana preservation, so these cut surface of banana crown is bad and be graded 70–79 .If there is no skin from the rachis be cut off and banana fingers not separated from banana hand by the tool, and the cut surface have little rough edges and not very nearer to banana stalk, the cut surface quality grade is good for banana preservation, so these cut surface of banana crown is good and be graded 80–89 .If there is no skin from the rachis be cut off and banana fingers not separated from banana hand by the tool and the cut surface have no rough edge and not nearer to banana stalk, the cut surface is very good for banana preservation, so the quality of these cut surface of banana crown is very good and be graded 90–100 .The indexes on number of cut sets are shown in The indexes on diameter of banana rachis are shown in The indexes on cutting speed are shown in The indexes on angle between thick cutter and axis of banana rachis are shown in The indexes on edge angle of thick cutter are shown in The indexes on width of thick cutter are shown in The indexes on thickness of thick cutter are shown in The indexes on width of thin cutter are shown in The indexes on thickness of thin cutter are shown in The banana mechanical crown cutting tool by combined cutters way is a critical component of banana crown cutting machine which requires less energy consumption and get high grade of cut surface quality. For banana fresh preservation, get high grade of cut surface quality is more significant than consume less energy. Results of experiments show that the optimum parameters are as follows: cutting speed is about50-60 mm/s, number of cut sets are about 4–6, angle between thick cutter and axis of banana rachis is about 5°, width of thick cutter is about 8–14 mm, thickness of thick cutter is about 2–3 mm, edge angle of thick cutter is between 20° and 30°, width of thin cutter is about 10–14 mm and thickness of thin cutter is about 0.2–0.4mm.


Dynamic regulation of nanoparticles in a controllable manner has great potential in various areas. Compared to the individual nanoparticles, the assembled nanoparticles exhibit superior properties and functions, which can be applied to achieve desirable performances. Here, a pH‐responsive i‐motif DNA‐mediated strategy to tailor the programmable behaviors of erbium‐based rare‐earth nanoparticles (ErNPs) decorated copper doped metal‐organic framework (CPM) nanohybrids (ECPM) under physiological conditions is reported. Within the acidic tumor microenvironment, the i‐motif DNA strands are able to form quadruplex structures, resulting in the assembly of nanohybrids and selective tumor accumulation, which further amplify the ErNPs downconversion emission (1550 nm) signal for imaging. Meanwhile, the ECPM matrix acts as a near‐infrared (NIR) photon‐activated reactive oxygen species (ROS) amplifier through the singlet oxygen generation of the matrix in combination with its ability of intracellular glutathione depletion upon irradiation. In short, this work displays a classical example of engineering of nanoparticles, which will manifest the importance of developing nanohybrids with structural programmability in biomedical applications. “Unity makes strength,” the smart use of MOF‐based nanohybrid (ECPM) for depleting the intracellular GSH and thus increasing the delivery efficiency of the ECPM is reported. The unique acidity‐responsive assembly of ECPM enables in situ clustering of the nanohybrid in the acidic tumor microenvironment (TME), which can achieve NIR‐activated tumor‐specific cancer theranostics with negligible side effects. In particular, spatial regulation  in a programmable manner provides the opportunity to explore their superior properties and functions, which holds great potential in the area of nanophotonics, nanoelectronics, and nanomedicine. Among the developed strategies, DNA nanotechnology stands out to organize nanomaterials in a controllable way. The rigid double helix could be formed according to the specific Watson–Crick base pairing rules, which has been widely used as a fascinating template for positioning of nanoparticles with nanoscale precision. Intercalated motif (i‐motif) DNAs are four stranded quadruplex structure folded by the complementary cytosine rich sequences. By virtue of their pH‐sensitive feature, i‐motif DNAs can achieve the transformation from random coil to folded quadruplex structures under acidic pH conditions, which has been employed to construct pH sensors, pH‐responsive hydrogels and DNA motors, etc.The past decades have witnessed the explosive growth in the control of size, shape, composition, and physical and chemical properties of nanoparticles (NPs).1 More In contrast, larger nanomaterials are able to reduce the clearance and prolong retention in the tumor, yet the inability of biodegradation limits their further applications. One promising proposed approach to improve the delivery efficiency is using the strategy of in situ self‐assembly. During the process of blood circulation, once smaller nanoparticles extravasate into the tumor region, nanoparticles surface changes in response to certain stimuli allow them to self‐assemble into larger particles. Such “size expansion” effect could easily trap nanoparticles within the local areas, hence increasing the tumor tissue uptake and minimizing the intravasation. To date, the responsive self‐assembly strategies for delivering imaging contrasts or therapeutic agents into the tumor site are still in their infancy, more efforts are needed to explore new ways of in situ assembly and how such assembled nanostructures can mediate their biological performances should be further investigated.In the field of nanomedicine, tailored nanostructures for efficient cellular uptake are critical for achieving various biological functions. It is generally accepted that relatively small particles within the size range of 5–100 nm easily penetrate into tumor area, while issues on the rapid clearance from the body also exist.5 In cm) in cancer cells might be one of the challenges for enhancing reactive oxygen species (ROS)‐mediated therapy efficacy. Moreover, the elevated level of GSH in cancer cells was revealed to increase resistance to photodynamic, chemo‐, and radiotherapies. Particularly, the intracellular GSH exhibits significant scavenging effect on reactive singlet oxygen produced by photo‐/sono‐sensitizers, increasing tumor resistance to oxidative stress and further diminishing the photo‐/sono‐dynamic efficacy. Therefore, it's highly desirable to develop strategy for circumventing the tumor resistance and thus improving the efficacy.Conceivably, glutathione (GSH) plays a very important role in maintaining various cellular processes including cellular metabolism and antioxidant defense. The highly expressed GSH  decorated copper doped metal‐organic framework (CPM) nanohybrids (ECPM) at the tumor site for amplifying the imaging signal and boosting the therapeutic efficacy. The virus‐like ECPM was composed of inner CPM and outer ErNPs, and the surface was further modified with pH‐responsive i‐motif DNA strands via the metal–phosphate coordination interactions Figure 1. Such 22.13+), in this work we used the Er3+ as the active dopant ion in our design, which could offer multiple excitation and emission pathways ranging from visible to NIR wavelengths. For this, the oleic acid capped core–shell NaGd0.9F4,Er0.1@NaGdF4 NPs (ErNPs) were firstly synthesized using a thermal decomposition method. As shown in Figure 0.9F4,Er0.1 core with a diameter around 5.4 nm and an inert layer of NaGdF4 shell, which could minimize surface and environmental quenching effect, thus improving visible light emission efficiency. The powder X‐ray diffraction (XRD) patterns confirmed the β‐phase structures , which demonstrated spherical shape structure with a diameter of ≈80 nm , Zr 3d3/2 (183.6 eV), and Zr–O (528.7 eV) mainly corresponded to the Zr‐containing secondary building unit nodes  in Figure 2+ with the nitrogen in ligand.To further explore the chemical structures of the CPM, the X‐ray photoelectron spectroscopy (XPS) measurement for CPM and high‐resolution analysis for Zr 3d, Cu 2p, and N 1s were carried out. As shown in Figure s Figure . The majs Figure . In addi While, the commonly used photosensitizer molecules encapsulation or loading strategies were largely held back by the low yield as well as leaching during the delivery process. The emergence of the structurally rigid porphyrin MOFs tends to address the above issues, as the chemical and physical properties of the active porphyrin ligands are well preserved in the MOFs matrix. Additionally, the advantages of MOFs matrix such as regular pores and channels are also beneficial for efficient diffusion of the reactant and products in confined microenvironment. Inspired by the outstanding performances of MOFs, the CPM was rationally integrated with luminescent ErNPs to form virus‐like ECPM nanohybrid structures, where the CPM acted as a NIR light photon harvester. For this, the ECPM nanohybrids were prepared by directly mixing CPM with PVP‐stabilized ErNPs at fixed ratio in N, N‐dimethylformamide (DMF) solution under stirring for overnight. The obtained ECPM nanohybrids demonstrated a virus‐like structure and there was almost no free ErNPs around  emission centered around 1550 nm, which was ascribed to the transition from 4I13/2 to 4I15/2  and red (657 nm) light, which could be absorbed by the inter CPM through fluorescence resonance energy transfer (FRET) . The results revealed that the energy transfer efficiency from the ErNPs to inter CPM could be calculated (1−τDA/τD) to be ≈46.6%. Excitingly, the DCL emission of ECPM was independent of the integration of CPM, indicating that the ECPM could be acted as a stable NIR‐II image probe  generation from CPM  was calculated to be 0.40 for ECPM by using methylene blue (MB) as the standard  Figure . The FRE) Figure . Time‐ree Figure . Due to M Figure . In the 2.2 The extracellular tumor area has lower pH value (pH ≈ 6.5), compared to the normal blood or healthy tissues (pH ≈ 7.4). Also, the pH value continues to drop in the intracellular organelles, such as endosome or lysosome (pH ≈ 5.5 or less). In order to achieve stimuli‐responsive ECPM within the acidic tumor microenvironment, pH‐responsive DNA linkers, which contain cytosine‐rich “i‐motif” domains  were applied to conjugate with ECPM  in neutral buffer (pH 7.4) was ≈167.3 nm, which was increased to ≈509.2 nm when exposed to solutions at pH 6.5   under a short time irradiation (5 min), verifying the combination of GSH scavenging effect and NIR‐induced photodynamic therapy , which reflected ongoing apoptosis of tumor cells ‐2,5‐diphenyltetrazolium bromide (MTT) assay, the ETPM had negligible cytotoxicity. The results showed low but detectable cytotoxicity on U87MG cells with ≈73.8% cell viability when the cells were treated with ECPM nanohybrids at higher concentration  imaging. The tumor, liver and spleen uptakes of ECPM were calculated by region of interest (ROI) analysis of the PET images. As shown in Figure −1 at 24 h postinjection (p. i.)  under 808 nm laser irradiation , we believed that this property could be used for tracking the ECPM in vivo. As shown in Figure  In addition, the ECPM could be easily cleared from the major organs over time  Figure . Such EC . The mice were treated with 980 laser irradiation (0.5 W cm−2) for 20 min at 24 h p.i. As shown in Figure NIR and ECPMD2NIR increased from 1.01 to 7.02 and 1.01 to 6.58, respectively . The significant differences in the experimental data were evaluated using one‐way ANOVA with Tukey's significant difference post hoc test (using Graphpad software). The calculated probability (p) was distinguished as *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001. Detailed processing of data for each analysis is described in each figure legend.Unless otherwise noted, all data are represented as the mean value ± standard deviation (SD) from at least 3 independent experiments (The authors declare no conflict of interest.L.H. and N.Z. contributed equally to this work. L.H., J.M., S.L., and X.C. designed this project. L.H., N.Z., S.W., and J.M. conducted the in vitro and in vivo experiments. Q.W., J.D., and G.C. run the optical experiments and interpreted the results. Z.W. carried out the PET study. Z.C. did the western blot experiments. The manuscript was written through contributions of all authors. All authors have given approval to the final version of the manuscript.Supporting InformationClick here for additional data file.


The objective of this study was to gain a deeper understanding of the morphoanatomical and histochemical structures that compose the nectary of pistillate flowers , which are involved in the female fertility of banana plants belonging to the ‘Cavendish’ subgroup. The diploid Calcutta 4 and the Grand Naine cultivar were used for the assessment. Five stages of floral development were proposed. Pistillate flower nectaries were subjected to morphological characterization, morphoanatomy, and histochemical tests . Morphoanatomical analysis revealed a greater presence of narrow nectariferous ducts and more developed pluristratified papillae in Calcutta 4. In contrast, Grand Naine displayed cell disintegration in nectariferous ducts and pluristratified papillae, absent transmitting tissue, and greater amounts of vascular bundles at anthesis. However, Calcutta 4 displayed no changes in the nectariferous duct at any of the stages. An association was found between phenolic compounds and lipids in vacuoles adjacent to the vascular bundles, with greater amounts found in Grand Naine. The localization of phenolic compounds may suggest that these compounds play a role in nectar secretion or the oxidation of the nectary region, ultimately limiting the growth and passage of the pollen tube and preventing ovule fertilization. Banana produces one of the most consumed tropical fruit in the world. As a result, banana trees are cultivated in extensive areas in the tropics and subtropics . In 2019Mycosphaerella fijiensis Morelet (anamorph: Pseudocercospora fijiensis (Morelet) Deighton) and Fusarium wilt (Fusarium oxysporum f. sp. cubense) [Triploid banana varieties are the most commercialized variety on the world market, owing to their favorable agronomic characteristics, such as nutritional quality and palatability. However, the diploid genotypes are important for breeding, as they are resistant to pests and diseases and are tolerant to abiotic factors, such as water deficit and extreme temperatures ,4. Bioticubense) ,6,7.Fusarium wilt is one of the main biotic stress factors affecting banana plantations and one of the most destructive diseases, with emphasis on the tropical race 4 variant in cultivars of the ‘Cavendish’ subgroup, characterized by yellowing of young leaves, splitting of the pseudostem and, eventually, plant death [nt death ,9,10,11.nt death .Banana production is also affected by black Sigatoka, characterized by streaks that lead to leaf necrosis at more advanced stages, in addition to interfering with photosynthesis and reducing the quantity and quality of fruits ,14. AgroFusarium wilt, the development of resistant cultivars through hybridization is fundamental for mitigating the effects of these diseases on farms [As the chemical control of black Sigatoka increases cost production and may impact human health and the environment, and control has not been generated for on farms ,15.One of the most serious limitations to the genetic improvement of bananas is the low fertility of some commercial cultivars, which restricts hybridization to the formation of few seeds and small progenies or causes the complete absence of seeds. Although the ‘Cavendish’ subgroup has very low fertility, the ability of this cultivar to obtain seed is not limited, as already reported by the Fundación Hondureña de Investigación Agrícola (Fhia) ,16,17,18Female sterility in banana plants is caused by several complex factors, which may act alone or together, such as the low germination rate of pollen grains, the slow and irregular growth of the pollen tube and the non-fertilization of ovules, and inhibition or failure of embryo sac development in pistillate flowers ,20,21,22Information regarding the reproductive barriers in pistillate flowers that limit genetic improvement and induce fertility issues in banana plants is scarce. Some studies have revealed that the pistillate flower nectary of the Grand Naine cultivar undergoes oxidation/necrosis that prevents female fertility ,24,25,26Understanding the structure and characterizing the chemical compounds in the septal nectary of pistillate flowers, as well as their relationship with sterility, may enable a better understanding of female fertility, in addition to providing subsidies for the development of new cultivars. Accordingly, the causes and the exact location of this barrier must be elucidated to enable the subsequent use of appropriate techniques to alleviate this barrier.Considering the lack of information regarding reproductive barriers in banana plants, the objective of the present study was to gain a deeper understanding of the morphoanatomical and histochemical structures that compose the septal nectary of pistillate flowers of cultivars belonging to the ‘Cavendish’ subgroup.Longitudinal sections of female banana flowers at different development stages and exposure to the nectary revealed that the Grand Naine cultivar had a region of oxidation in the nectary at S5, which was not observed in Calcutta 4 at the same floral development stage . HistochMusa spp. Was reported previously in M. textilis Nee [M. errans Teodoro var. botoan Teodoro [M. acuminata Colla cv. Dwarf ‘Cavendish’ [Septal nectaries located in the distal region of the ovary are formed by septa that together form a cavity. The location of the septal nectary in the distal region of the ovary in ilis Nee , M. erra Teodoro , and M. vendish’ ,30, corrCalcutta 4 was found to have smaller pistillate flowers than Grand Naine, according to the length and diameter of the septal nectaries presented in These findings indicate that S1 and S2 were significantly different between the genotypes in terms of the length of the septal nectaries in the Grand Naine cultivar. However, only S5 had a significant difference in diameter in this cultivar. S5 corresponds to the time when the inflorescence is in a pendulous position on the pseudostem, with flowers open and ready to be pollinated (anthesis).According to Waniale et al. , the lenMorphoanatomical sections of the floral developmental stages of the septal nectaries of pistillate flowers are presented in A cross-section of the septal nectaries displayed the presence of tubular canals or nectariferous ducts with ramifications, forming a complex and highly proliferated labyrinthine structure in both genotypes analyzed. Variations were observed in the nectariferous ducts, which formed a radiate pattern in a three-to-four-arm shape in Calcutta 4 B and GraDense cells were formed near the nectar ducts, which constitute the nectariferous tissue in Calcutta 4 C,G,H andThe epithelium that constitutes the nectariferous duct in the genotypes was formed by columnar cells and numerous pluristratified papillae, which lined the parenchyma D. CalcutThese observations suggest that further studies should be carried out to identify possible substances released from multi-stratified papillae and that they are related to the transmittal of the pollen tube in banana trees. In Calcutta 4, these papillae possibly favor female fertility, as they are larger than those in Grand Naine, which appear to be damaged. Accordingly, Calcutta 4 facilitates the orientation and passage of the tube and the consequent fertilization of the ovules.Fundamental parenchymal tissue was found to line the septal nectary in Calcutta 4 and Grand Naine, with a large number of parenchymal cells observed A. HoweveThe fundamental or filling parenchyma is characterized by cells with thin primary walls, large vacuoles, and characteristic intercellular spaces , which wAccording to Ren and Wang , the parThe size of the intercellular spaces observed in Calcutta 4 and Grand Naine increased toward the vascular zone, where the vascular bundles are located E. These The presence of numerous vascular bundles near the septal nectaries may increase nectar production, which is secreted directly from the epidermis of the carpel external wall and contributes to the vascularization of the nectary ,33.Substances, such as amino acids, proteins, mucilage, lipids, alkaloids, phenolic compounds (PCs), terpenoids, glycosides, organic acids, mineral ions, vitamins, antibiotics, and antioxidants, are reported to be an integral part of the nectar composition of different species ,34,35.M. velutina, M. ornata, and M. cv. Go Sai Yung) and reported a similar septal nectary anatomical structure in the investigated species, such as the presence of epithelium in the duct formed by columnar and papillary cells.The results obtained in the present study corroborate those of Kirchoff , who anaM. basjoo, Ensete glaucum, and Musella lasicarpa. These researchers observed epithelial cells, vascular tissue, and nectary opening similarities. However, the differences involved the shape of the longitudinal and cross-sectional sections, the arrangement of secretory cuticles, and the presence of fibrillar material.Similar results were reported by Ren and Wang , who desM. acuminata cv. Dwarf ‘Cavendish’ by Fahn and Benouaiche [The same nectary morphology was found in male and female flowers of nouaiche . AccordiHerein, transmitting tissue could only be observed in Calcutta 4 and was parallel to the nectary region J. HoweveAccording to some authors, the transmitting tissue nourishes the pollen tube, as it is composed of, among other substances, polysaccharides and proteins, which are responsible for pollen growth ,37,38. TBarbosa  used fluThe transmitting tissue divides into three channels toward each ovary loculus near the base of the stipe . In thisGrand Naine exhibited cell disintegration in septal nectary ducts at S5 J. Such dFahn and Benouaiche  reportedAccording to Soares et al. , the GraBarbosa  observedAs shown in Total PCs were evident in fundamental parenchyma cells near the vascular bundles and adjacent to the nectary in Calcutta 4 and Grand Naine A–C,J–L. −1, respectively. This study showed that in the septal nectaries of the pistillate flowers, phenolic compounds can be indicators of female fertility since they show similar effects in the diploid Calcutta 4 when compared with the cultivar Grand Naine.This microscopic observation of visualization made it possible to verify the presence of PC in the nectaries, which corroborates the study carried out by Silva et al. , who evaThe location of PC adjacent to the septal nectaries may suggest that it plays a role in nectar secretion or the oxidation of the nectary region, limiting the growth and passage of the pollen tube and preventing ovule fertilization in cultivars of the ‘Cavendish’ subgroup. This last supposition may be reinforced by the lower levels of these compounds in septal nectaries of fertile diploids, as mentioned also by Silva et al. .According to Rocha , total PPCs are secondary metabolites associated with different biological activities in plants . SeveralThe test used to verify total proteins (TP) revealed the presence of this chemical component with reddish coloration in the cytoplasm of the nectary cells, and a greater amount in the pluristratified papillae of Calcutta 4 D–F and GProteins are naturally present in plant cells, and their activities are related to the amount of substrates present . Based o−1 g−1, peroxidase (0.89 and 0.78 µMoles min−1 g−1), and polyphenoloxidase (3.75 and 2.76 µMoles min−1 g−1). This study showed that enzymatic activities can be indicators of female fertility, suggesting the performance of crosses from the E3 stage, in cultivars of the ‘Cavendish’ subgroup, to verify the formation of fruits with seeds. The test for lipids revealed that these biomolecules are located in cells containing the total PC and adjacent to the vascular bundles in Calcutta 4  .Musa acuminata (AA) is assumed to contribute to female infertility in ancestral banana genomes, leading to parthenocarpy. However, due to its inherent properties, such as male and/or female sterility and unreduced gamete formation, genetic factors conditioning parthenocarpy have not been fully elucidated [The absence of seeds and, consequently, sterility in banana plants may result from intense agronomic selection and a reflection of the domestication process of the species over the years. According to some researchers, chromosomal translocations and abnormal meiosis, such as embryo sac abortion, are causes of infertility that have no direct genetic origin but are instead dependent on specific conditions ,20,21. Fucidated ,50.Two banana genotypes were selected according to the degree of female fertility: diploid Calcutta 4 (considered fertile) and the Grand Naine cultivar of the ‘Cavendish’ subgroup (considered to have a high degree of sterility) ,17,24,48Five stages of floral development were proposed for the genotypes used in the study .This proposal was based on the classification established by Fortescue and Turner , which r®, Wetzlar, Germany), and measurements were determined using the ImageJ software. All analyses were performed using three nectaries per stage, with three repetitions (replicates) for each genotype.Pistillate flowers were collected from the bunches to remove the septal floral nectaries and carry out subsequent morphological characterization. Fresh samples were employed to measure the length and diameter of the septal nectary; photographs were obtained using a stereoscopic microscope  , subjecttorresin  for solitorresin , and moutorresin .In order to analyze the main groups of secondary metabolites, subsequent longitudinal and transverse sections were performed on a rotating microtome , with a thickness of 8 µm, and subjected to the following histochemical tests: 10% ferric chloride  to detecIn triploid banana cultivars (AAA), sterility hinders the genetic improvement of the crop. Therefore, it is very important to understand the morphoanatomy of the flower, the pollen–pistil interaction, and the dynamics of pollen tube growth, as only a few studies have been conducted on the sterility process. Furthermore, information on the structure and composition of the septal nectaries of banana flowers is scarce. Nonetheless, the hypotheses proposed in this study may help future research. The knowledge acquired will also serve as a basis for the formulation of strategies to overcome the fertility issue in banana plants, ultimately assisting with the development of new cultivars of the ‘Cavendish’ subgroup. The use of new techniques, such as fluorescence microscopy, is recommended to verify the dynamics of the pollen tube in the stages analyzed, in addition to histochemical tests to identify substances and the chemical composition of the nectar to verify its influence on pollen tube development and fertilization in cultivars of the ‘Cavendish’ subgroup.


Xenopus, but it was unclear if these mechanisms are conserved in mammals. Here, we report that mammalian ADAM9 cleaves ephrin-B1 and ephrin-B2 and can substitute for Xenopus ADAM13 to induce the neural crest. We found that ADAM9 expression is elevated in human colorectal cancer (CRC) tissues and that knockdown (KD) of ADAM9 inhibits the migration and invasion of SW620 and HCT116 CRC cells by reducing the activity of Akt kinase, which is antagonized by ephrin-Bs. Akt is a signaling node that activates multiple downstream pathways, including the Wnt and mTOR pathways, both of which can promote CRC cell migration/invasion. Surprisingly, we also found that KD of ADAM9 downregulates Wnt signaling but has negligible effects on mTOR signaling in SW620 cells; in contrast, mTOR activity is suppressed while Wnt signaling remains unaffected by ADAM9 KD in HCT116 cells. These results suggest that mammalian ADAM9 cleaves ephrin-Bs to derepress Akt and promote CRC migration and invasion; however, the signaling pathways downstream of Akt are differentially regulated by ADAM9 in different CRC cell lines, reflecting the heterogeneity of CRC cells in responding to manipulations of upstream Akt regulators.Ephrin-B signaling has been implicated in many normal and pathological processes, including neural crest development and tumor metastasis. We showed previously that proteolysis of ephrin-B ligands by the disintegrin metalloprotease ADAM13 is necessary for canonical Wnt signal activation and neural crest induction in  The Eph receptors are the largest class of receptor tyrosine kinases (RTKs) and key regulators of cell adhesion, migration, and sorting. These receptors can be divided into two subclasses based on their cognate ligands: EphA receptors, which preferentially bind the glycosylphosphatidylinositol-anchored ephrin-A ligands, and EphB receptors, which preferentially bind the transmembrane ephrin-B ligands , 2. UnliProtein ectodomain shedding, often mediated by members of A Disintegrin and Metalloprotease (ADAM) family, is a key mechanism for regulating cell signaling . ADAMs aXenopus embryos  in different CRC cell lines, likely due to the presence of different mutations in these cells.In the present study, we found that mammalian ADAM9 cleaves ephrin-B1 and -B2 and can substitute for et al., unpublished data). Since there is no good antibody for the ectodomain of either ephrin, we overexpressed both ephrins with an N-terminal HA tag. Western blotting detected a fragment of HA-tagged ephrin-B1 ectodomain shed into the conditioned media, which was enhanced when myc-tagged WT mouse ADAM9 but not the protease-dead E348A mutant was coexpressed (A). A similar cleavage product was detected for ephrin-B2, although coexpression of WT ADAM9 and longer exposure were needed (B). The shed ectodomain of both ephrins are ∼22 kDa, similar to the size of Xenopus ephrin-B2 shed by ADAM13  results show that both siRNAs, AD9-1 and AD9-2, caused 70 to 80% reduction in ADAM9 mRNA, and Western blotting confirms that the endogenous ADAM9 protein was also markedly reduced (C and D). Transfection with either siRNA decreased the ephrin-B1 ectodomain shed into the conditioned media and increased the full-length ephrin-B1 in the cell lysate (E and F). It has been shown that ephrin-B1 and EphB3 are the only ephrin-B ligand and functional EphB receptor, respectively, detectable in HCT116 cells (G), indicating an upregulation of forward ephrin-B signaling, possibly by blocking ligand cleavage. We further tested if mouse ADAM9 is the mammalian functional equivalent of Xenopus ADAM13. Like Xenopus ADAM13 . Thus, mammalian ADAM9 can functionally substitute for Xenopus ADAM13 to cleave ephrin-Bs and induce the neural crest.In a candidate screen to search for mammalian metalloproteases responsible for shedding key cell-surface proteins involved in Wnt signaling, we identified ADAM9 as a main sheddase for mouse ephrin-B1 and -B2 when coexpressed in HEK293T cells . Similar inhibition was obtained in both cell lines using the siRNA AD9-2 . A similar reduction was observed in SW620 cells (B). Because Wnt signaling can facilitate CRC migration and invasion (C). The cellular levels of β-catenin are usually kept in check by the kinase GSK3, which forms a complex with the scaffold proteins adenomatous polyposis coli (APC) and Axin to phosphorylate β-catenin at Thr41, Ser37, and Ser33 residues, leading to the ubiquitination and degradation of β-catenin. Binding of Wnt ligands to cell-surface Frizzled receptors and coreceptors causes inhibition and dissociation of the β-catenin destruction complex, and the stabilized β-catenin can translocate into the nucleus, where it functions as a transcriptional coactivator (D and S3A). In stark contrast, no reduction in active β-catenin was detected in HCT116 cells, despite a decrease of total β-catenin (E and S3B). The lack of reduction in active β-catenin provides an explanation for the lack of response of Wnt-mediated transcriptional activity to ADAM9 KD in HCT116 cells.We previously attributed the ability of al crest , 19. KD  induced , 21. Lik induced A. A simi20 cells B. Becausinvasion , this reinvasion C. The cectivator , 29. Howctivator . Our Wesctivator D and S3A-catenin E and S3BCHAC1, DDIT4, and SLC1A4, three of the genes positively regulated by mTOR signaling (A–C). In line with this, KD of ADAM9 in HCT116 cells drastically reduced phospho-S6K, a signature mTOR target that facilitates tumor invasion including CRC invasion (D and S4A). A main upstream regulator of mTOR signaling is Akt, which activates mTOR primarily by phosphorylating and inhibiting tuberous sclerosis complex 2 (TSC2), a well-characterized mTOR inhibitor . The inhibition of Akt activation by ADAM9 KD was confirmed using siAD9-2 (E and S4C). Thus, while ADAM9 is indispensable for Akt activation in both cell lines, it appears to regulate the downstream Wnt and mTOR signaling differently in these cells. This phenomenon could be attributed to the underlying genetic mutations in these cell lines . Together, these results suggest that ADAM9 promotes CRC cell migration and invasion by modulating ephrin-B signaling and Akt activity.We next tested if ADAM9 regulates CRC migration/invasion m of Akt  rescued m of Akt Fig. S6)via ephrim of Akt . Transfem of Akt , C and DE–G and via EphB3 can promote Akt dephosphorylation through protein phosphatase 2A (PP2A), leading to inhibition of lung cancer invasion (E and F and A and B). Of note, the inhibition of Wnt signaling by ephrin-B1ΔC in HEK293T cells can be partially rescued by the PP2A inhibitor okadaic acid (F), suggesting that forward ephrin-B signaling antagonizes Wnt signaling through PP2A.Finally, we asked how ADAM9 activates Akt. Akt is usually activated by PI3K, which can in turn be induced by growth factor–activated RTKs such as the epidermal growth factor receptor (EGFR) . A previinvasion . We theraic acid F, suggesADAM9 mRNA is also elevated in CRC tissues and identified Akt and downstream Wnt and mTOR signaling as the main targets for ADAM9 in CRC cells. Two published works have linked ADAM9 to Akt activity in esophageal squamous cell carcinoma and triple-negative breast cancer, respectively (D and E). Moreover, although an earlier report implicated overexpressed ADAM9 in shedding of pro-HB-EGF , we propose that ADAM9-mediated ephrin-B shedding activates Akt, as well as downstream Wnt and mTOR signaling in SW620 and HCT116 cells, respectively, to promote migration and invasion (G). In CRC, forward ephrin-B signaling is a tumor suppressor pathway, whereas Wnt and mTOR are two oncogenic pathways . In contrast, HCT116 cells harbor a heterozygous 3-bp deletion in CTNNB1 that eliminates Ser45 of the encoded β-catenin protein (E and S3B), suggesting that ADAM9-regulated Akt fails to affect β-catenin localization in this cell line. One possible explanation is that, in the absence of Ser45 phosphorylation, β-catenin cannot localize to the plasma membrane due to the low affinity for E-cadherin and probably other classical cadherins, even when Akt activity and Ser552 phosphorylation are reduced by ADAM9 KD. Since LEF/TCF-mediated transcriptional activity correlates with active but not total β-catenin (C).Perhaps the most puzzling result of this study is the differential regulation of Wnt and mTOR signaling, two signaling pathways downstream of Akt, by ADAM9 in SW620 and HCT116 cells  and 4. As in CRC , 59. SW6s in CRC  , a  protein . This mu protein . However protein . Interes protein E and S3B-catenin , the dec-catenin C.D and E). Besides elevated Wnt signaling, oncogenic APC inactivation also leads to hyperactivation of mTORC1, and inhibition of mTORC1 protects from intestinal tumorigenesis and certain other defects caused by APC inactivation , as, asD andion  were subcloned into pCS2+ (see Xenopus laevis EphB1ΔK construct was a gift from Dr Ira Daar. MK-2206 was purchased from Selleckchem (Cat. #: S1078). Antibodies used in this study include rabbit anti-HA  3724, 1:1000), mouse anti-myc , rabbit anti-ADAM9 , rabbit anti-phospho-EphB3(Y608) , rabbit anti-active-β-catenin , rabbit anti-β-catenin , rabbit anti-phospho-p70 S6 kinase , rabbit anti-p70 S6 kinase , rabbit anti-phospho-AKT(S473) , and rabbit anti-AKT1/2/3 . Secondary antibodies that were used include horseradish peroxidase (HRP)-conjugated rabbit anti-mouse  and goat anti-rabbit . HRP-conjugated mouse anti-β-actin  was used as a loading control. The following siRNAs were used in this study: control (CST 6568), AD9-1 (CST 11968), AD9-2 (Ambion 4390826), and ephrin-B1 (Dharmacon L-003658-00-0010).The expression construct for caAKT was a gift from Dr Richard Roth (Addgene #10841) . The com2. SW620 cells (ATCC) were cultured in Leibovitz's L-15 (ATCC) and supplemented with 10% FBS at 37 °C with 0% CO2. Cells were transfected with plasmids (400 ng/ml) or siRNA (100 nM) at 70% confluency, using Lipofectamine 3000 (Invitrogen). For experiments that used both siRNA and plasmid, siRNA was transfected first, and the medium was replaced with fresh before the plasmid was transfected on the following day. For TOP/FOPFLASH assays, cells were transfected with TOPFLASH or FOPFLASH construct for 24 h and luciferase assays were carried out as described previously (HCT116 cells (ATCC) were cultured in McCoy’s 5A (ATCC) supplemented with 10% fetal bovine serum  at 37 °C with 5% COeviously . For cleeviously , and Wesg for 10 min at 4 °C to remove any debris. The amount of protein in each sample was measured by bicinchoninic acid assay (Millipore Sigma), and 30 μg protein extract was loaded per lane for Western blot analyses. For cleavage assays, the conditioned media were concentrated by centrifugation at 6000g for 30 min at 4 °C using centrifugal filters with 3 kDa molecular weight cutoff (Millipore UFC500396), and 40 μl of the supernatant was loaded per lane for Western blot analyses. SDS-PAGE was run on precast acrylamide gels (Bio-Rad) until the desired separation was achieved, and gels were transferred onto 0.2 um pore PVDF membranes (Bio-Rad) using the Trans-Blot Turbo transfer system (Bio-Rad). Western blot detection was conducted with HRP-conjugated secondary antibodies and chemiluminescence substrates (Bio-Rad) using a Bio-Rad ChemiDoc imager, as described previously  supplemented with protease and phosphatase inhibitor cocktails (Invitrogen) and o-phenanthroline (Millipore Sigma) at 10 mM final concentration for 30 min on ice and centrifuged at 18,000eviously . For RT-4 cells were plated in the top chamber of 8.0 μm inserts . For invasion assays, wells were coated with Matrigel according to manufacturer’s protocol (Corning 354234). Cells in serum-free medium were plated in the upper chamber, and the medium containing 10% FBS was added in the lower chamber. After 22 h of incubation at 37 °C, the cells were fixed in 4% formaldehyde and stained with 0.1% crystal violet, and cells that invaded through the pores were counted under a Zeiss Axio V16 microscope. Three chambers were used per condition. The values obtained were calculated by averaging the total number of cells from three filters.For transwell migration assays, 5 × 10X. tropicalis adults were purchased from NASCO. Live animal manipulation was performed in accordance with the guidelines and regulations set and enforced by the Institutional Animal Care and Use Committees at West Virginia University and the University of Delaware. Morpholino oligo targeting ADAM13 (13-3) was designed and generated by Gene Tools . cDNA was obtained from 2 μg of total RNA using Revertra Ace qPCR RT master mix (TOYOBO). Quantitative real-time PCR was performed using Faststart universal SYBR green master (Roche), and relative quantification was calculated by normalizing to the amount of β-actin mRNA. See All data are contained within this article.This article contains The authors declare that they have no conflicts of interest with the contents of this article.


Degeneracy in biological systems refers to a many-to-one mapping between physical structures and their functional  outcomes. Despite the ubiquity of the phenomenon, traditional analytical tools for modeling degeneracy in neuroscience are extremely limited. In this study, we generated synthetic datasets to describe three situations of degeneracy in fMRI data to demonstrate the limitations of the current univariate approach. We describe a novel computational approach for the analysis referred to as neural topographic factor analysis (NTFA). NTFA is designed to capture variations in neural activity across task conditions and participants. The advantage of this discovery-oriented approach is to reveal whether and how experimental trials and participants cluster into task conditions and participant groups. We applied NTFA on simulated data, revealing the appropriate degeneracy assumption in all three situations and demonstrating NTFA’s utility in uncovering degeneracy. Lastly, we discussed the importance of testing degeneracy in fMRI data and the implications of applying NTFA to do so.The online version of this article (10.1007/s12021-022-09580-9) contains supplementary material, which is available to authorized users. Degeneracy refers to the capability of different structures to produce the same effects , to examine degeneracy in functional neuroanatomy. Our model is built off of earlier topographic factor analysis approaches  in ways that are unbeknownst to investigators. Thus, it is important to develop an analytical approach that can identify sources of structure in signal with minimal supervision - that is, without relying on strong In this paper, our goal is to validate NTFA using a simulation approach. Computational simulations are critical to test whether novel computational models are capable of performing as expected in principle, that is, under conditions with a known ground truth. In practice, the data generating mechanisms for functional neuroanatomy are rarely, if ever, known. That is why it is of particular importance in cognitive neuroscience to develop modeling approaches that are capable of providing insight as to whether there is likely to be degeneracy in functional neuroanatomy from the data alone and with minimal supervision. Using computational simulations, we first demonstrate the considerable shortcomings of applying the most commonly used “univariate” activation-based analytical approach in fMRI data analysis when there is degeneracy. In the typical form of this analysis, a general linear model is used to determine whether functional activity in a given voxel or brain region (i.e. set of voxels) is greater during trials from one experimental condition relative to a baseline condition. We then implement NTFA on simulated datasets with minimal assumptions about whether trials ought to be nested into particular task conditions, or participants into particular groups. Our deliverable is a demonstration of the ability of NTFA to recover embeddings that reveal degeneracy, and non-degeneracy, in simulated 4D timeseries data with topological structure (e.g. as in fMRI data).Rather than extensively review the various forms of degeneracy that can occur in the brain, we generated a synthetic dataset to demonstrate two aspects of degeneracy that could occur in fMRI data. There could be many reasons for degeneracy, as noted in the introduction and as we speculate upon in the discussion. The focus of this paper is to illustrate how well certain models would perform when the assumption of degeneracy by condition holds. We opt to use simulation data for two reasons: 1) the synthetic data allows us to mathematically specify the assumption of degeneracy, and 2) the synthetic data also provides a known ground truth to validate NTFA’s performance.The synthetic dataset reflects a generic experimental framework in which participants undergo a baseline condition and an experimental condition. In this simulated experiment, participant completed eight trials total. The baseline condition has two trials and the experimental condition has six trials. Each trial contains 20 TRs. The synthetic dataset used a downsampled MNI template with a 8x8x8mm voxel size.To offer a concrete example, in a study on fear, the baseline condition may consist of multiple trials that maintain a neutral affective state in the baseline condition and multiple trials that induce fear in the experimental condition and. In a study on working memory, there may be trials that involve low capacity demand in the baseline condition, and trials that involve high capacity demand in the experimental condition. We used the term, trial, to broadly represent trials in sequence , or the specific contents of a trial in a task . Degeneracy may occur in either case. In the simulated data, there are three trials of type A, B, C in the experimental condition and a baseline trial type in for each scenario. We varied the underlying distribution for the trial types to reflect the assumption of degeneracy.We simulated multivariate patterns of neural activity throughout the brain by sampling from a prespecified underlying distribution. We assumed a single baseline state such that the neural activity of the baseline condition is generated from one distribution. We then modeled three hypothetical situations to reflect different assumptions of degeneracy, which are described in more detail in the subsequent section Fig. . For simSince this paper is interested in variations in the task-related signal, the synthetic dataset is meant to resemble a denoised dataset in real life. The simulation did not include a hemodaynamic function or any nuisance related signal  that might be present in the real data. We simulated the data under varying additive noise conditions to show reliability.The non-degenerate functional neuroarchitecture stipulates that experimental trials evoking a common psychological state or process share a common underlying pattern of activation. We generated simulated data to fit this assumption. We started by selecting three brain areas randomly to create a pattern of activation during experimental condition trials Fig. A. We choDegeneracy by condition refers to the existence of multiple distinct patterns of neural activation that occur across trials of the same experimental condition. Using fear as our running example, different fear induction trials may involve different patterns of brain activation Fig. B. To simFor our third situation, we examined degeneracy with respect to both condition and participant. Similar to the example in the degeneracy by condition scenario, a participant would have different patterns of activation during different trials of the same experimental condition. In addition, however, the participant would also have a different pattern of neural activation than other participants, even during the same trial. For example, both participants may report experiencing the same level of fear when shown the same fear-inducing stimulus, but nevertheless show differential activation patterns.This situation is illustrated in Fig. We applied a standard univariate General Linear Model (GLM) to calculate a contrast between the experimental conditions and the baseline condition. We implemented the GLM in which each trial was modeled as a separate regressor, such that the model estimated a statistical map for each trial. The model then calculated a contrast on trials in the experimental condition and on trials in the baseline condition to assess which voxels showed greater activity in the experiment conditions than in the baseline condition. The average betas over two participants was presented. The model did not include nuisance regressors and were not convolved with a hemodynamic response function since the synthetic data did not include nuisance related signal and was not convolved with hemodynamic function since they were not included in the simulated dataset.NTFA is a class of generative models built off of earlier topographic factor analysis (TFA) approaches for fMRI data  and trial dependent (s) activity is estimated across the spatial factors  and how multiple individuals might respond to a the same trial in a task condition . By combining estimates of these sources of variation, we are able to detect whether neural activity in response to the same trial varies systematically across individuals, which we refer to as participant task combinations. Similar to the approach used for the spatial embeddings, participant dependent  embeddings. We achieve this goal by formalizing three assumptions:Taken together, these spatial and activation embeddings respectively provide a low-dimensional summary of where and how individuals’ brains respond to an experiment. Critically, the activation embeddings also summarize whether such responses are shared or diverge across individuals, hereby revealing potential degeneracy. In the following subsections, we first discuss NTFA generative model in detail "". We theFirst is to assume that a segment of fMRI data consisting of T time points and V voxels Second, the model assumes that for a given participant “p” in a segment, the parameters that define matrix F can be generated from a lower dimensional vector F for participants across the experiment. Third, the model also assumes that given a participant-trial combination “W for this segment are generated by another lower dimensional vector The crux of NTFA’s generative model can be explained in three parts. n consists of a participant P participants Below is the link to the electronic supplementary material.


The collection and analysis of biological samples are an effective means of disease diagnosis and treatment. Blood sampling is a traditional approach in biological analysis. However, the blood sampling approach inevitably relies on invasive techniques and is usually performed by a professional. The microneedle (MN)-based devices have gained increasing attention due to their noninvasive manner compared to the traditional blood-based analysis method. In the present review, we introduce the materials for fabrication of MNs. We categorize MN-based devices based on four classes: MNs for transdermal sampling, biomarker capture, detecting or monitoring analytes, and bio-signal recording. Their design strategies and corresponding application are highlighted and discussed in detail. Finally, future perspectives of MN-based devices are discussed. Blood sampling has become a common method in modern medical diagnosis due to its high efficiency and low cost. Many biometric tests are based on blood samples. However, the invasive sampling methods always accompanied subcutaneous acupuncture or finger pricks that usually lead to a decrease in patient compliance . MeanwhiDermal interstitial fluid (ISF) is a portion of the fluid that seeps into the interstitial tissues from the arterial ends of capillaries. ISF acts as an intermediary between cancer cells and the circulatory system. Previous studies have proved that the composition and concentration of electrolytes, small molecules, and proteins in ISF are similar to those in plasma . FurtherThe skin, the body’s largest organ, is a rich resource supply of ISF. However, the extraction of this fluid is restricted by a skin barrier. The stratum corneum, which is 15–20 μm thick, effectively prevents foreign substances from penetrating the skin . MicroneIn general, MN-based devices can be classified into four categories according to their functional purposes : 1) MNs In the present review, we focus on the recent advances of microneedle-based devices. The four categories of MN-based devices and their applications are highlighted and discussed in detail. Finally, the future perspectives of MN-based devices are summarized.Four types of MNs  have been used for transdermal sampling . The proin vivo. Solid MNs and hollow MNs, made by silicon, glass, and stainless steel, are usually used for transdermal sampling . NormallSolid MNs and hollow MNs have greatly facilitated transdermal sampling. Nonetheless, instrumental assistance and multi-step operations are usually required to maintain a negative pressure during the preparation of MNs, which limits their application. Additionally, glass- or silicon-based MNs often suffer from brittleness, which poses a potential safety risk to patients and causes environmental hazards . One solin vitro and in vivo biocompatibility was demonstrated. The collection of dermal ISF in vivo is also studied for subsequent proteomic applications. in vitro.Another emerging good candidate for transdermal sampling is swelling MNs, which generally consist of cross-linked polymer networks and enable one-step ISF extraction without the aid of extra devices. Hydrogels are biocompatible and biodegradable. They are able to cause minimal tissue damage and little environmental threat after disposal . Chang eThe MN array designed for biomarker capture is an emerging approach in modern medical diagnosis. As shown in in vitro E2 detection tests and in vivo skin tests of experimental animals with response signals obtained within 1 min.As shown in Apart from immunoaffinity, Watson–Crick base pairing has also been applied in MN systems for biomarker capture. Al Sulaiman developed alginate–peptide nucleic acid-coated MNs that are capable of sequence-specific capture of target miRNAs by Watson–Crick base pairing  Al Sula. Attachiin situ capture of Epstein–Barr virus cell-free DNA (EBV Cf DNA) from ISF in 15 min with a capture efficiency as high as 93.6% . Since the MN array combines advantages of aptamers and porous structures, its surface area is remarkably increased to 6.694 m2/g, so a large amount of aptamer probes (0.9459 μM) can be fixed. Furthermore, due to capillary forces, the MN array can extract ISF into its porous structure. Subsequently, biomarkers are captured and detected without sample post-processing.It is worth noticing that aptamers can be potentially applied in MN arrays for biomarker capture. Aptamers are recognized as single-stranded oligonucleotides in 25–80 base length that exhibit specific binding affinity toward targets including amino acids, drugs, and protein biomolecules. In comparison with protein antibodies, aptamers have several advantages such as small size, strong binding affinity, high specificity, desirable biocompatibility, good stability, and lesser immunogenicity, making them widely used in the field of biomedicine . AptamerMN-based sensors have been employed widely for detecting or monitoring a diverse range of analytes as listed in As displayed in in vitro and in vivo detection of lactate in different biological samples  nanostructures that serve as an active H2O2 sensing modulus hexanethiol/highly porous gold (FAD-GDH/FcSH/h-PG) MN-based biosensor was fabricated for minimally invasive sensing of glucose in artificial interstitial fluid   was commal fluid . In addial fluid . Functioal fluid . Mohan ein vitro) in the ISF with high accuracy, high reproducibility, and excellent linearity (0–630 mg/dl) in real time. Hollow MN-based sensors were also prepared by traditional electrochemical sensing element embedment in the hollow MNs. Compared to aforementioned MNs, this approach provides additional protection for the sensing elements. For example, MN-based organophosphorus hydrolase (OPH) sensors were reported for minimal-invasive measurement of transdermal threat compounds, organophosphate (OP)  . The senate (OP) . The devIn addition to solid and hollow MNs, some groups attempt to employ porous MNs for electrochemical sensors. By combining a sponge-like porous PDMS matrix with a hyaluronic acid (HA) coating, the prepared MNs exhibited desirable mechanical properties, and the MNs were able to penetrate the skin and are flexible after insertion into the skin . It was in situ SERS measurements in skin phantoms first. They fabricated Ag-coated MNs as SERS probes for sensitive detection of target molecules at depths beneath 700 μm, simulating the absorption and scattering of light by human skin. in vivo quantitative study of glucose in type I diabetes (Surface-enhanced Raman scattering (SERS) is noninvasive spectral technology, which is the result of enhanced sensitivity of Raman spectral fingerprint and local surface plasmon resonance . The quadiabetes . The resin situ. In addition to Ag NPs, Au NPs have also been employed for enhancement of the Raman signal in MN-based sensors. The colorimetric sensors possess advantages including being easy to operate and not needing expensive or complex equipment . EspeciaSome groups reported a MN-based colorimetric sensor for glucose detection. P. falciparum. The device was able to detect a target protein concentration as low as 8 ng/ml. Each test could be completed within 20 min and did not require additional equipment. MN-based colorimetric sensors for detection of multiple health-related biomarkers have also been reported by in vitro, ex vivo, and in vivo, and to monitor changes in the concentration of biomarkers over a long period of time (at least 4 days). Such capacity shows great potential for long-term health monitoring.In addition to glucose, MN-based colorimetric sensors have been successfully used for rapidly detecting protein bio-markers in dermal ISF . Sample Both humans and animals produce regular electrical signals in static and active states. Monitoring these biological signals, for example, electromyogram (EMG), electrocardiogram (ECG), and electroencephalogram (EEG), can help to understand human pathology and physiology . Conventw is the half-cell potential. The interface between the wet electrode Ag/AgCl and the electrolytic gel could be simulated by the parallel connection of capacitor Cd and resistor Rd. Rg represents the electrical resistance of the gel used in the experiment. Ese represents the potential difference between the gel and the stratum corneum. The stratum corneum can also be modeled by a capacitor Ce and a resistor Re in parallel. Ru represents the resistance of the dermis and subcutaneous tissue. The equivalent circuit of MAE is relatively simple. Since the MNs are in direct contact with the epidermis, there is only coupling between the electrodes and the conductive layers within the skin, except for the conductive resistance of the dermis and underlying tissue, described by the half-cell potential Em and connected in parallel with the resistance Rm and the capacitance Cm.As a kind of dry electrode, the MN array electrode (MAE) was first proposed by 2 @10 Hz was attained. Flexibility of P-MNEA contributes to recording stability, and P-MNEA realizes credible EEG acquisition.To date, MN-based devices have been successfully used in ECG, EMG, and EEG recording . The proMetal materials are also good candidate materials for MEA fabrication. For example, MEA with MNs with a length of 550 μm could be constructed with a magnetization-induced self-assembly approach . The MNsin situ practicability and long-term stability to realize real-time biosignal recording of ECG and EMGs.Apart from silicon and metal, polymers could also be considered for MN electrodes. A novel MN array–based dry electrode modified with a ring-shaped flexible polyimide substrate matrix was fabricated by in vivo detection and in vitro detection. Pig skin is usually employed as a model for in vitro detection because of its similar histological and biochemical properties to human skin (in vivo model is not ideal due to economic, moral, and legal reasons (In the last decades, the advanced properties of MNs have driven the development of MN biomedical applications. However, most of the commercial MNs have focused on delivery of drugs and vaccines . Nowadayman skin . Howeverman skin . The in  reasons .in situ skin tools for MN assessment. For example, multifunctional animal-free 3D tools have proven their great potential for rapidly and economically evaluating MN devices (Simpler and more economical micromachining techniques are needed to be developed to achieve a mass production of high-precision MNs. The 3D printing technique holds great potential for scalable MN production. MNs must be made of materials that are harmless and nonirritating. Meanwhile, the MN-based devices must be rigorously disinfected before clinical application to get rid of the microorganisms’ contaminations under the skin surface. Although metal or silicon MNs can usually be easily hyperpyrexia sterilized, polymer MNs can be rendered to deformation under such conditions, and alternative sterilization methods are required. Additionally, due to the complex composition of body fluid, the stability of the MN-based sensors after contact with body fluid should also be assessed. Therefore, further development of materials for the preparation of microneedles is needed in the future. It is necessary to develop easy-to-adjust and versatile  devices . More an


Migration and invasion transwell assays were performed in β-catenin/vector overexpressed A375 and MV3 cells treated with 100 μM DHC. Scale bar, 100 μm.  The protein expression of β-catenin, MMP2 and MMP7 in β-catenin/vector overexpressed A375 and MV3 cells treated with 100 μM DHC for 48 h.  The mRNA expression of MMP2 and MMP7 in β-catenin/vector overexpressed A375 and MV3 cells treated with 100 μM DHC for 48 h. *P < 0.05; **P < 0.01; ***P < 0.001” and “Overexpression of β-catenin retrieves DHC-induced inhibition of tumor growth and pulmonary metastasis of melanoma cells. (A) Colonies generated by β-catenin/vector overexpressed A375 and MV3 cells after treatment with 100 μM DHC for 3 weeks. Scale bar, 1 mm. (B) Tumor volume of β-catenin/vector overexpressed A375 xenograft tumors in mice after treatment with DHC (20 mg/kg/day for 28 days) and DMSO.  The tumors in mice were excised and weighed. (E) IHC of β-catenin and Ki67 in the xenograft tumors. Scale bar, 100 μm. (F) H&E staining of the lungs from β-catenin/vector overexpressed A375 metastasis mice model after treatment with DHC (20 mg/kg/day for 45 days) and DMSO. *P < 0.05; **P < 0.01; ***P < 0.001” appear below.In the original article, there were mistakes in The authors apologize for these errors and state that this does not change the scientific conclusions of the article in any way. The original article has been updated.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.