Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 50
Filtrar
1.
Langmuir ; 39(48): 17427-17435, 2023 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-37975860

RESUMO

Although the self-transport of liquid droplets by a gradient-textured substrate can break away from the energy input, the long distance and even continuous spontaneous motion of droplets will be limited by the length in the surface-gradient direction. This article introduces a novel design with a monolayer graphene-covered multibranch gradient groove surface (GMGGS). The design aims to achieve long-distance, continuous self-transport of a mercury (Hg) droplet by merging with other mercury droplets, and the process is carried out using molecular dynamics (MD) simulation. This method achieves the merging of mercury droplets through the structure of multibranch gradient grooves, and we have observed that the merged mercury droplet can be reaccelerated in the gradient groove. The results demonstrate that droplet merging allows for control over the surface morphology variations of mercury droplets within the gradient groove. This creates a forward pressure difference, which leads to reacceleration of the mercury droplets. In light of this mechanism, the trunk droplet can achieve long-distance continuous self-transport on the GMGGS by continuously merging with branch droplets. These findings will broaden our comprehension of droplet merging and self-transport behavior, offering corresponding theoretical support for the long-distance continuous self-transport of droplets.

2.
Langmuir ; 39(24): 8379-8389, 2023 06 20.
Artigo em Inglês | MEDLINE | ID: mdl-37282616

RESUMO

The presence of microorganisms on biomedical devices and food packaging surfaces poses an important threat to human health. Superhydrophobic surfaces, a powerful tool to combat pathogenic bacterial adhesion, are threatened by their poor robustness. As a supplement, photothermal bactericidal surfaces may be expected to kill adhered bacteria. Using copper mesh as a mask, we prepared a superhydrophobic surface with a homogeneous conical array. The surface shows synergistic antibacterial properties, including a superhydrophobic character against bacterial adhesion and photothermal bactericidal activity. As a result of the excellent liquid repellency, the surface could highly repel the adherence of bacteria after immersing in a bacterial suspension for 10 s (95%) and 1 h (57%). Photothermal graphene can easily eliminate most adhered bacteria during the subsequent treatment of near-infrared (NIR) radiation. After a self-cleaning wash, the deactivated bacteria were easily rinsed off the surface. Furthermore, this antibacterial surface exhibited an approximately 99.9% resisted bacterial adhesion rate regardless of planar and various uneven surfaces. The results offer promising advancement of an antibacterial surface combining both adhesion resistance and photothermal bactericidal activity in fighting microbial infections.


Assuntos
Antibacterianos , Aderência Bacteriana , Humanos , Antibacterianos/farmacologia , Antibacterianos/química , Bactérias
3.
Appl Microbiol Biotechnol ; 106(5-6): 2017-2027, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35171339

RESUMO

A hyperthermostable xylanase XYN10B from Thermotoga maritima (PDB code 1VBR, GenBank accession number KR078269) was subjected to site-directed and error-prone PCR mutagenesis. From the selected five mutants, the two site-directed mutants (F806H and F806V) showed a 3.3-3.5-fold improved enzyme half-life at 100 °C. The mutant XYNA generated by error-prone PCR showed slightly improved stability at 100 °C and a lower Km. In XYNB and XYNC, the additional mutations over XYNA decreased the thermostability and temperature optimum, while elevating the Km. In XYNC, two large side-chains were introduced into the protein's interior. Micro-differential scanning calorimetry (DSC) showed that the melting temperature (Tm) dropped in XYNB and XYNC from 104.9 °C to 93.7 °C and 78.6 °C, respectively. The detrimental mutations showed that extremely thermostable enzymes can tolerate quite radical mutations in the protein's interior and still retain high thermostability. The analysis of mutations (F806H and F806V) in a hydrophobic area lining the substrate-binding region indicated that active site hydrophobicity is important for high activity at extreme temperatures. Although polar His at 806 provided higher stability, the hydrophobic Phe at 806 provided higher activity than His. This study generates an understanding of how extreme thermostability and high activity are formed in GH10 xylanases. KEY POINTS: • Characterization and molecular dynamics simulations of TmXYN10B and its mutants • Explanation of structural stability of GH10 xylanase.


Assuntos
Endo-1,4-beta-Xilanases , Thermotoga maritima , Endo-1,4-beta-Xilanases/metabolismo , Estabilidade Enzimática , Modelos Moleculares , Mutação , Temperatura , Thermotoga maritima/genética
4.
Am J Physiol Cell Physiol ; 316(3): C299-C311, 2019 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-30462539

RESUMO

Hepatocellular carcinoma (HCC) is known for its high mortality rate worldwide. Based on intensive studies, microRNA (miRNA) expression functions in tumor suppression. Therefore, we aimed to evaluate the contribution of miR-146a-5p to radiosensitivity in HCC through the activation of the DNA damage repair pathway by binding to replication protein A3 (RPA3). First, the limma package of R was performed to differentially analyze HCC expression chip, and regulative miRNA of RPA3 was predicted. Expression of miR-146a-5p, RPA3, and DNA damage repair pathway-related factors in tissues and cells was determined. The effects of radiotherapy on the expression of miR-146a-5p and RPA3 as well as on cell radiosensitivity, proliferation, cell cycle, and apoptosis were also assessed. The results showed that there exists a close correlation between miR-146a and the radiotherapy effect on HCC progression through regulation of RPA3 and the DNA repair pathway. The positive rate of ATM, pCHK2, and Rad51 in HCC tissues was higher when compared with that of the paracancerous tissues. SMMC-7721 and HepG2 cell proliferation were significantly inhibited following 8 Gy 6Mv dose. MiR-146a-5p restrained the expression of RPA3 and promoted the expression of relative genes associated with the DNA repair pathway. In addition, miR-146a-5p overexpression suppresses cell proliferation and enhances radiosensitivity and cell apoptosis in HCC cells. In conclusion, the present study revealed that miR-146a-5p could lead to the restriction of proliferation and the promotion of radiosensitivity and apoptosis in HCC cells through activation of DNA repair pathway and inhibition of RPA3.


Assuntos
Carcinoma Hepatocelular/genética , Reparo do DNA/genética , Proteínas de Ligação a DNA/genética , Neoplasias Hepáticas/genética , MicroRNAs/genética , Tolerância a Radiação/genética , Adulto , Idoso , Apoptose/genética , Linhagem Celular , Linhagem Celular Tumoral , Proliferação de Células/genética , Feminino , Regulação Neoplásica da Expressão Gênica/genética , Células HEK293 , Células Hep G2 , Humanos , Masculino , Pessoa de Meia-Idade , Transdução de Sinais/genética
5.
Xenotransplantation ; 26(3): e12498, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30770572

RESUMO

BACKGROUND: Old World non-human primates (OWNHPs) are used for preclinical pig-to-NHP studies. However, like pigs, OWNHPs express Neu5Gc, and therefore do not develop natural anti-Neu5Gc antibodies. New World NHPs (NWNHPs) have been reported not to express Neu5Gc. We investigated the potential of NWNHPs in xenotransplantation research. METHODS: We investigated expression of Gal, Neu5Gc, and Sda antigens on RBCs and PBMCs from humans, selected OWNHPs, and capuchin monkeys (a NWNHP). Serum anti-Gal and anti-Neu5Gc IgM and IgG levels were measured by ELISA. Binding of primate serum IgM and IgG to pig RBCs was measured by flow cytometry. RESULTS: (a) Neither humans, OWNHPs, or capuchin monkeys expressed Gal on their RBCs, but capuchins expressed Gal on PBMCs. Humans and capuchins did not express Neu5Gc on either RBCs or PBMCs, but OWNHPs expressed Neu5Gc on both cells. Sda was not expressed on any RBCs or PBMCs. (b) By ELISA, human and OWNHP, but not capuchin, sera showed IgM and IgG binding to Gal. Human and capuchin, but not OWNHP, sera demonstrated some binding to Neu5Gc. (c) Anti-Sda IgM/IgG antibodies were detected in OWNHP sera. Knockout of Sda on pig RBCs did not significantly reduce human and capuchin antibody binding. CONCLUSION: Capuchin monkeys could be surrogates for humans in experiments using RBCs, islets, neuronal cells, etc, from triple-knockout pigs (but may be too small to be used as recipients of pig organ grafts).


Assuntos
Carboidratos/imunologia , Galactosiltransferases/imunologia , Xenoenxertos/imunologia , Transplante Heterólogo , Animais , Animais Geneticamente Modificados , Carboidratos/genética , Cebus , Galactosiltransferases/genética , Técnicas de Inativação de Genes , Rejeição de Enxerto/imunologia , Humanos , Platirrinos , Suínos
6.
Sensors (Basel) ; 19(11)2019 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-31167471

RESUMO

The existing compressive sensing (CS) reconstruction algorithms require enormous computation and reconstruction quality that is not satisfying. In this paper, we propose a novel Dual-Channel Reconstruction Network (DC-Net) module to build two CS reconstruction networks: the first one recovers an image from its traditional random under-sampling measurements (RDC-Net); the second one recovers an image from its CS measurements acquired by a fully connected measurement matrix (FDC-Net). Especially, the fully connected under-sampling method makes CS measurements represent original images more effectively. For the two proposed networks, we use a fully connected layer to recover a preliminary reconstructed image, which is a linear mapping from CS measurements to the preliminary reconstructed image. The DC-Net module is used to further improve the preliminary reconstructed image quality. In the DC-Net module, a residual block channel can improve reconstruction quality and dense block channel can expedite calculation, whose fusion can improve the reconstruction performance and reduce runtime simultaneously. Extensive experiments manifest that the two proposed networks outperform state-of-the-art CS reconstruction methods in PSNR and have excellent visual reconstruction effects.

7.
Stat Med ; 37(28): 4216-4233, 2018 12 10.
Artigo em Inglês | MEDLINE | ID: mdl-30039588

RESUMO

Due to the low signal-to-noise ratio and high-dimensional structure, spatiotemporal data analysis is challenging. In outbreak detection, the assumptions for control charts, including independence, normality, and stationarity, are often violated in syndromic surveillance data. We develop a novel hybrid hierarchical Bayesian model through the combination of the Dirichlet process and particle filters to resolve these issues. We use a modified adjacency matrix as the observation matrix in the Markovian state-space model. This methodology achieves dimension reduction and computational efficiency and enjoys a superior detection performance with the ability to incorporate online updating for data streaming applications. Our data set is derived from the Indiana Public Health Emergency Surveillance System. It consists of surveillance data on emergency room visits for influenza-like and respiratory illness from 2008 to 2010. We are able to detect the 2009 H1N1 outbreak as well as the seasonal influenza outbreaks. Numerical results show that our Dirichlet process/particle filter models improve the outbreak detection performance in both simulation and real data analysis.


Assuntos
Teorema de Bayes , Análise Espaço-Temporal , Análise por Conglomerados , Interpretação Estatística de Dados , Surtos de Doenças/estatística & dados numéricos , Humanos , Cadeias de Markov , Modelos Estatísticos , Vigilância da População/métodos , Razão Sinal-Ruído
8.
Xenotransplantation ; 25(3): e12393, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29655276

RESUMO

An important question in xenotransplantation is whether an allotransplant can safely be carried out in a patient who has become sensitized to a pig xenograft. To answer this question, we have searched the literature. We primarily limited our review to the clinically relevant pig-to-non-human primate (NHP) model and found five studies that explored this topic. No NHP that had received a pig graft developed antibodies to alloantigens, and in vitro studies indicated no increased humoral and/or cellular alloreactivity. We carried out a small in vitro study ourselves that confirmed this conclusion. There have been three experiments in which patients undergoing dialysis were exposed to wild-type pig kidneys and three clinical studies related to bridging a patient in hepatic failure to liver allotransplantation. Despite the development of anti-pig antibodies, all subsequent organ (kidney or liver) allografts were successful (except possibly in one case). In addition, pig fetal islets were transplanted into patients with kidney allografts; there was no increase in panel-reactive alloantibodies and the kidney grafts continued to function satisfactorily. In conclusion, the limited data suggest that, after sensitization to pig antigens, there is no evidence of antibody-mediated or accelerated cellular rejection of a subsequent allograft.


Assuntos
Antígenos/imunologia , Rejeição de Enxerto/imunologia , Sobrevivência de Enxerto/imunologia , Transplante Heterólogo , Animais , Humanos , Transplante de Rim/métodos , Suínos , Transplante Heterólogo/métodos , Transplante Homólogo/métodos
9.
Small ; 13(33)2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28692766

RESUMO

Vertically oriented highly crystalline 2D layered (BA)2 (MA)n-1 Pbn I3n+1 (BA = CH3 (CH2 )3 NH3 , MA = CH3 NH3 , n = 3, 4) perovskite thin-films are fabricated with the aid of ammonium thiocyanate (NH4 SCN) additive through one-step spin-coating process. The humidity-stability of the film is certified by the almost unchanged X-ray diffraction patterns after exposed to humid atmosphere (Hr = 55 ± 5%) for 40 d. The photovoltaic devices with the structure of indium tin oxide(ITO)/poly(3,4-ethylenedioxythiophene):poly(styrene-sulfonate)/(BA)2 (MA)n-1 Pbn I3n+1 (n = 3,4)/[6,6]-phenyl-C61 -butyric acid methyl ester/Bathocuproine/Ag are fabricated. The devices based on (BA)2 (MA)2 Pb3 I10 perovskite (n = 3) with the precursor composition of BAI:methylammonium iodide:PbI2 :NH4 SCN = 2:2:3:1 (by molar ratio) show an averaged power conversion efficiency (PCE) of 6.82%. In the case of (BA)2 (MA)3 Pb4 I13 (n = 4), a higher PCE of 8.79% is achieved. Both of the unsealed devices perform unique stability with almost unchanged PCE during the period of storage in purified N2 glove box. This work provides a simple and effective method to enhance the efficiency of the 2D perovskite solar cell.

10.
Xenotransplantation ; 24(4)2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28547819

RESUMO

The results of the assay for measuring anti-non-Gal antibodies (which affect pig xenograft survival) in recipients are important. Serum incubation time and concentration may be important factors in the extent of antibody binding to the graft. The aim of this in vitro study was to determine the optimal incubation time and serum concentration for measuring anti-non-Gal antibody binding to porcine aortic endothelial cells (pAECs). Pooled human, naive, and sensitized baboon sera were incubated with wild-type, α1,3-galactosyltransferase gene-knockout (GTKO), and GTKO/human CD55 pAECs. IgM/IgG binding to pAECs after varying serum incubation times (0.5, 1, 2, and 3 hour) and concentrations (5, 10, 20, and 40 µL) was determined by flow cytometry. An increase in incubation time from 30 minutes to 2 hour was associated with increases in anti-non-Gal IgM/IgG binding to GTKO and GTKO/hCD55 pAECs of pooled human, naive and sensitized baboon sera (P<.05). Pooled human serum showed a significant increase in anti-non-Gal IgM (1.5 times) and a minimal increase in anti-non-Gal IgG antibody binding. IgM/IgG binding of sensitized baboon serum to GTKO pAECs after 2-hour incubation was 1.5 times and 2 times greater than after 30-minutes incubation, respectively, whereas naïve baboon sera showed minimal (non-significant) increase in anti-non-Gal IgM/IgG antibody binding. With 2-hour incubation, increasing the serum concentration from 5 µL to 20 µL significantly increased antibody binding to non-Gal antigens in pooled human and sensitized baboon serum. With naïve baboon serum, only IgG was significantly increased. Increasing the serum incubation time contributed to improve the sensitivity of detecting anti-non-Gal antibodies, without affecting cell viability in vitro.


Assuntos
Células Endoteliais/metabolismo , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Animais , Animais Geneticamente Modificados/imunologia , Anticorpos Heterófilos/sangue , Células Endoteliais/imunologia , Técnicas de Inativação de Genes , Rejeição de Enxerto/imunologia , Sobrevivência de Enxerto/imunologia , Xenoenxertos/imunologia , Humanos , Imunoglobulina G/imunologia , Imunoglobulina M/imunologia , Suínos , Fatores de Tempo , Transplante Heterólogo/métodos
11.
Xenotransplantation ; 24(2)2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-28303661

RESUMO

BACKGROUND: Genetically engineered pigs could provide a source of kidneys for clinical transplantation. The two longest kidney graft survivals reported to date have been 136 and 310 days, but graft survival >30 days has been unusual until recently. METHODS: Donor pigs (n=4) were on an α1,3-galactosyltransferase gene-knockout (GTKO)/human complement regulatory protein (CD46) background (GTKO/CD46). In addition, the pigs were transgenic for at least one human coagulation regulatory protein. Two baboons received a kidney from a six-gene pig (GroupA) and two from a three-gene pig (GroupB). Immunosuppressive therapy was identical in all four cases and consisted of anti-thymoglobulin (ATG)+anti-CD20mAb (induction) and anti-CD40mAb+rapamycin+corticosteroids (maintenance). Anti-TNF-α and anti-IL-6R mAbs were administered to reduce the inflammatory response. Baboons were followed by clinical/laboratory monitoring of immune/coagulation/inflammatory/physiological parameters. At biopsy or euthanasia, the grafts were examined by microscopy. RESULTS: The two GroupA baboons remained healthy with normal renal function >7 and >8 months, respectively, but then developed infectious complications. However, no features of a consumptive coagulopathy, eg, thrombocytopenia and reduction of fibrinogen, or of a protein-losing nephropathy were observed. There was no evidence of an elicited anti-pig antibody response, and histology of biopsies taken at approximately 4, 6, and 7 months and at necropsy showed no significant abnormalities. In contrast, both GroupB baboons developed features of a consumptive coagulopathy and required euthanasia on day 12. CONCLUSIONS: The combination of (i) a graft from a specific six-gene genetically modified pig, (ii) an effective immunosuppressive regimen, and (iii) anti-inflammatory therapy prevented immune injury, a protein-losing nephropathy, and coagulation dysfunction for >7 months. Although the number of experiments is very limited, our impression is that expression of human endothelial protein C receptor (±CD55) in the graft is important if coagulation dysregulation is to be avoided.


Assuntos
Rejeição de Enxerto/imunologia , Sobrevivência de Enxerto/imunologia , Transplante de Rim , Rim/cirurgia , Transplante Heterólogo , Animais , Animais Geneticamente Modificados , Rejeição de Enxerto/genética , Sobrevivência de Enxerto/genética , Humanos , Imunossupressores/administração & dosagem , Rim/imunologia , Transplante de Rim/métodos , Papio , Suínos , Transplante Heterólogo/métodos , Transplantes/efeitos dos fármacos , Transplantes/imunologia , Fator de Necrose Tumoral alfa/imunologia
12.
Phys Chem Chem Phys ; 19(5): 3440-3458, 2017 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-28094830

RESUMO

Nowadays, organic solar cells (OSCs) with efficiencies over 10% have been achieved through the elaborate design of electron donors and fullerene acceptors. However, the drawbacks of fullerene acceptors, like poor absorption, limited chemical and energetic tunabilities, high-cost purification and morphological instability, have become the bottlenecks for the further improvement of OSCs. To overcome the mentioned shortages from fullerene, research studies on non-fullerene electron acceptors have boomed. To date, the highest efficiency of fullerene-free OSCs has been pushed to be 12%, which surpasses that of fullerene-based OSCs. In this perspective, we focus on summarizing the development of small molecule electron acceptors designed to replace the fullerene derivatives. Since it has been revealed that the search for matched donor:acceptor pairs is important for accomplishing high efficiencies, we therefore divide electron acceptors into several categories according to the donors used in fullerene-free OSCs. After the introduction of these acceptors, we outline the designing rules as well as perspectives for the development of non-fullerene acceptors. We believe that the development of non-fullerene electron acceptors will make organic photovoltaics closer to practical applications.

13.
J Am Chem Soc ; 138(8): 2528-31, 2016 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-26876042

RESUMO

Herein we present a new structural design of hole-transporting material, Trux-OMeTAD, which consists of a C3h Truxene-core with arylamine terminals and hexyl side-chains. This planar, rigid, and fully conjugated molecule exhibits excellent hole mobility and desired surface energy to the perovskite uplayer. Perovskite solar cells fabricated using the p-i-n architecture with Trux-OMeTAD as the p-layer, show a high PCE of 18.6% with minimal hysteresis.

14.
Nanotechnology ; 27(31): 315702, 2016 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-27335235

RESUMO

Precisely controlling the deformation of carbon nanotubes (CNTs) has practical application in the development of nanoscale functional devices, although it is a challenging task. Here, we propose a novel method to guide the deformation of CNTs through filling them with salt water and applying an electric field. With the electric field along the axial direction, the height of CNTs is enlarged by the axial electric force due to the internal ions and polar water molecules. Under an electric field with two mutually orthogonal components, the transverse electric force could further induce the bending deformation of CNTs. Based on the classical rod and beam theories, two mechanical models are constructed to verify and quantitatively describe the relationships between the tension and bending deformations of CNTs and the electric field intensity. Moreover, by means of the electric field-driven tension behavior of CNTs, we design a stretchable molecular sieve to control the flow rate of mixed gas and collect a single high-purity gas. The present work opens up new avenues in the design and fabrication of nanoscale controlling units.

15.
Zhong Yao Cai ; 38(1): 160-2, 2015 Jan.
Artigo em Zh | MEDLINE | ID: mdl-26214885

RESUMO

OBJECTIVE: To study the glycosides from Guangdong Liangcha Granules. METHODS: The chemical constituents were isolated by various chromatographic techniques and the structures of chemical constituents were identified by spectroscopic analysis and literature. RESULTS: Six compounds were isolated and identified as ilexoside B (1), asprellanosides B (2), asprellanoside A (3), 4', 5 ,7 -tri- hydroxyflavone-6-O-ß3-D-glucopyranosyl ester(4), isoviolanthin (5),3-O-methy-lellagic acid 4'-O-rhamnopyranoside (6). CONCLUSION: Compounds 1 - 5 are firstly obtained from Guangdong Liangcha Granules.


Assuntos
Medicamentos de Ervas Chinesas/química , Glicosídeos/análise , Saponinas , Triterpenos
16.
ACS Sens ; 9(6): 2907-2914, 2024 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-38759108

RESUMO

Flexible self-powered tactile sensors, with applications spanning wearable electronics, human-machine interaction, prosthetics, and soft robotics, offer real-time feedback on tactile interactions in diverse environments. Despite advances in their structural development, challenges persist in sensitivity and robustness, particularly when additional functionalities, such as high transparency and stretchability. In this study, we present a novel approach integrating a bionic fingerprint ring structure with a PVDF-HFP/AgNWs composite fiber electrode membrane, fabricated via 3D printing technology and electrospinning, respectively, yielding a triboelectric nanogenerator (TENG)-based self-powered tactile sensor. The sensor demonstrates high sensitivity (5.84 V/kPa in the 0-10 kPa range) and rapid response time (10 ms), attributed to the microring texture on its surface, and exhibits exceptional robustness, maintaining electrical output integrity even after 24,000 cycles of loading. These findings highlight the potential of the microring structures in addressing critical challenges in flexible sensor technology.


Assuntos
Biônica , Tato , Dispositivos Eletrônicos Vestíveis , Humanos , Eletrodos , Fontes de Energia Elétrica , Impressão Tridimensional , Polivinil/química
17.
Cancer Lett ; 558: 216060, 2023 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-36813648

RESUMO

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). .

18.
ACS Appl Mater Interfaces ; 15(46): 54119-54128, 2023 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-37942537

RESUMO

The capture and utilization of underwater fuel bubbles such as methane can alleviate the greenhouse effect, solve the global energy crisis, and possibly improve the endurance of underwater equipment. However, previous research routinely failed to achieve the integrated process of continuous adsorption, transportation, and collection of bubbles limited by the trade-off between the bubble adhesion and transport efficiency dependent on interfacial pinning, tremendously hindering the direct capture and utilization of underwater fuel bubbles. To break through this bottleneck, a magnetic-guided conical arrayed surface (CAS) associated with a laser etching technique is fabricated conveniently to realize superhydrophobicity. The bubbles on laser-etched CAS have higher adhesiveness and low-pinning transport compared with those on the nonlaser-etched surface. Intriguingly, the gas film adsorbed within the CAS seems to be a gas channel, which accelerates the bubble coalescence and fast spreading to eventually realize the integration of transport, coalescence, and collection. The dynamic behaviors of bubble adsorption, transportation, and coalescence on CAS are probed to reveal the mechanism of the gas film-generating process within conical arrays. Furthermore, a novel underwater bubble-collecting device with multiangled CAS is proposed to achieve multidirectional capture, highly efficient transportation, and collection of rising bubbles. The results advance our understanding of dynamic behaviors of bubbles at solid-liquid interfaces and facilitate design and manufacturing of an apparatus for bubble collection.

19.
Microsyst Nanoeng ; 9: 119, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37780811

RESUMO

The manipulation of fast, unidirectional motion for large droplets shows important applications in the fields of fog collection and biochemical reactions. However, driving large droplets (>5 µL) to move directionally and quickly remains challenging due to the nonnegligible volume force. Herein, we fabricated a scalable, bionic peristome substrate with a microcavity width of 180 µm using a 3D printing method, which could unidirectionally drive a large water droplet (~8 µL) at a speed reaching 12.5 mm/s by temperature-responsive wettability. The substrate surface was grafted with PNIPAAm, which could reversibly change its wettability in response to temperature, thereby enabling a temperature-responsive smart surface that could regulate droplet movement in real-time by changing the temperature. A series of temperature-responsive smart patterns were designed to induce water transport along specific paths to further realize controllable droplet motion with the antibacterial treatment of predesignated areas. The ability to achieve temperature-responsive unidirectional motion and dynamic control of droplet movement could allow programmable fluidic biosensors and precision medical devices. A temperature-responsive smart surface was produced to control the unidirectional motion of large droplets between spreading and pinning movement by changing the surface wettability.

20.
RSC Adv ; 13(40): 27839-27864, 2023 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-37731827

RESUMO

With the increasing shortage of water resources, people are seeking more innovative ways to collect fog to meet the growing need for production and the demand for livelihood. It has been proven that fog collection is efficient for collecting water in dry but foggy areas. As a hot research topic in recent years, bionic surfaces with fog collection functions have attracted widespread attention in practical applications and basic research. By studying natural organisms and bionic surfaces, more avenues are provided for the development of fog collection devices. Firstly, starting from biological prototypes, this article explored the structural characteristics and fog collection mechanisms of natural organisms such as spider silk, desert beetles, cactus, Nepenthes and other animals and plants (Sarracenia, shorebird and wheat awn), revealing the fog collection mechanism of the natural organisms based on microstructures. Secondly, based on the theory of interfacial tension, we would delve into the fog collection function's theoretical basis and wetting model, expounding the fog collection mechanism from a theoretical perspective. Thirdly, a detailed introduction was given to prepare bionic surfaces and recently explore fog collection devices. For bionic surfaces of a single biological prototype, the fog collection efficiency is about 2000-4000 mg cm-2 h-1. For bionic surfaces of multiple biological prototypes, the fog collection efficiency reaches 7000 mg cm-2 h-1. Finally, a critical analysis was conducted on the current challenges and future developments, aiming to promote the next generation of fog collection devices from a scientific perspective from research to practical applications.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA