Modulating the activation state and degree of macrophages still remains as a challenge for the topographical design of Ti-based implants.In this work,micro/nano-structured coatings were prepared on Ti substrates by mi...Modulating the activation state and degree of macrophages still remains as a challenge for the topographical design of Ti-based implants.In this work,micro/nano-structured coatings were prepared on Ti substrates by micro-arc oxidation(MAO)and subsequent hydrothermal(HT)treatment.By varying the HT conditions,plate-like nano-structures with an average length of 80,440 or 780 nm were obtained on MAO-prepared micro-topographical surfaces.Depending on the dimensional features of nano-plates,the specimens were noted as Micro,Micro/Nano-180,Micro/Nano-440 and Micro/Nano-780,respectively.The in vitro results showed that the activation state and degree of macrophages could be effectively modulated by the micro/nano-structured surfaces with various dimensional features.Compared to the Micro surface,the Micro/Nano-180 surface activated both M1 and M2 phenotype in macrophages,while the Micro/Nano-440 and Micro/Nano-780 surfaces polarized macrophages to their M1 phenotype.The activation degree of M1 macrophages followed the trend:Micro<Micro/Nano-180<Micro/Nano-440<Micro/Nano-780.However,the osteogenic potential of the activated macrophages in response to various surfaces were in the order:Micro≈Micro/Nano-780<Micro/Nano-180<Micro/Nano-440.Together,the findings presented in this work indicate that engineering nano-structures with controllable dimensional features is a promising strategy to modulate macrophage activation state and degree.In addition,it is essential to determine the appropriate activation degree of M1 macrophages for enhanced osteogenesis.展开更多
A novel micro heat pipe array was used in solar panel cooling. Both of air-cooling and water-cooling conditions under nature convection condition were investigated in this paper. Compared with the ordinary solar panel...A novel micro heat pipe array was used in solar panel cooling. Both of air-cooling and water-cooling conditions under nature convection condition were investigated in this paper. Compared with the ordinary solar panel, the maximum difference of the photoelectric conversion efficiency is 2.6%, the temperature reduces maximally by 4.7℃, the output power increases maximally by 8.4% for the solar panel with heat pipe using air-cooling, when the daily radiation value is 26.3 MJ. Compared with the solar panel with heat pipe using air-cooling, the maximum difference of the photoelectric conversion efficiency is 3%, the temperature reduces maximally by 8℃, the output power increases maximally by 13.9% for the solar panel with heat pipe using water-cooling, when the daily radiation value is 21.9 MJ.展开更多
Digital micro-thruster arrays can be used for special missions of micro/nano-satellites with the requirements of high precision and small impulse.This paper presents a novel control allocation algorithm for the digita...Digital micro-thruster arrays can be used for special missions of micro/nano-satellites with the requirements of high precision and small impulse.This paper presents a novel control allocation algorithm for the digital micro-thruster array,namely status graph based control allocation(SGBCA)algorithm,which aims at finding the optimal micro thrusters combination scheme to realize the sequential control synthesis for micro/nano-satellite during real-time orbit control tasks.A mathematical model is set up for the control allocation of this multivariate over-actuated system.Through dividing thrusters into disjoint segments by offline calculation and combining segments dynamically online to provide a sequence of the required impulse for the micro/nano-satellite,the time complexity of the control allocation algorithm decreases significantly.All levels of impulse can be generated by the digital micro thruster arrays and the service life of the arrays can be extended using the segment converting strategy proposed in this paper.The simulation indicates that the algorithm can satisfy the requirements of real-time orbit control for micro/nano-satellites.展开更多
Recently,the possibility of a disaster due to the improper use of highly toxic gases which are known as agents throughout the world has been increased.Therefore,the development of technology for countermeasure against...Recently,the possibility of a disaster due to the improper use of highly toxic gases which are known as agents throughout the world has been increased.Therefore,the development of technology for countermeasure against CWA has been highly demanded.In this study,thick film SnO_2-based gas sensing devices were prepared and the sensing properties for the four different kinds of simulants such as dimethyl methyl phosphonate (DMMP),acetonitrile,dichloromethane and dipropylene glycol methyl ether have been investigated.And a micro sensor array consists of six devices was prepared using MEMS technology to provide high selective and reliable sensing system for the detection of chemical warfare agents.The micro gas sensor array prepared showed good sensitivity and selectivity to CWA.展开更多
An uncommon fractal construction method is applied in the microwave element design. A novel fractal defected ground structure （DGS） based on micro electro-mechanical system （MEMS） is proposed. The size of this nov...An uncommon fractal construction method is applied in the microwave element design. A novel fractal defected ground structure （DGS） based on micro electro-mechanical system （MEMS） is proposed. The size of this novel fractal DGS can achieve 86% size reduction compared with the conventional dumbbell type DGS. This novel fractal DGS is used in the miniaturization design of L-band microstrip antenna array. The simulation result shows that this novel fractal DGS can effectively reduce the mutual coupling between the antenna elements, so it is helpful to the miniaturization of microstrip array, namely the approximately same gain value can be achieved with the shorter distance between elements.展开更多
Aim of the study: Immunohistochemical evaluation of hormone receptors, Her2/neu, CK5/6, E-cadherin, beta-catenin, p53 and PTEN on Tissue Micro Array (TMA) of 46 Moroccan invasive breast carcinomas. Materials and Metho...Aim of the study: Immunohistochemical evaluation of hormone receptors, Her2/neu, CK5/6, E-cadherin, beta-catenin, p53 and PTEN on Tissue Micro Array (TMA) of 46 Moroccan invasive breast carcinomas. Materials and Methods: The cases comprised 40 invasive ductal carcinomas, 4 invasive lobular carcinomas, 1 mixed carcinoma and 1 invasive colloid carcinoma. TMA paraffin blocs were prepared with the Beecher manual arrayer and immunostaining was performed using standard immunoperoxidase techniques. Results: 58.69% of the cases were ER positive. 43.18% (19/44) were triple negative breast cancers (TNBC) of which 15.78% (3/19) were of the basal phenotype expressing CK5/6. On the other hand, 72.22% (13/18) of the TNBC cases were IDC grade 3. Of the 18 IDC grade 3, 22.22% (4/18) were CK5/6 positive. 41.30% and 10.86% of the cases showed reduced expression of E-cadherin and beta-catenin respectively. Beta-catenin nuclear and cytoplasmic staining was noted in 20% and 97.82% respectively. p53 was overexpressed in 10.86% of the cases whereas PTEN loss or reduced expression was noted in 86.95% of the cases. Conclusion: The aim of our study was to introduce TMA technique in our hospital which is considered a reference institution for cancer in Morocco. Although no statistical study was performed to look for any significance of the results obtained, we found good correlation with some of the data in the literature. To determine the molecular characteristics, if any, of the Moroccan patient, larger multidisciplinary and prospective studies would be interesting in the aim to personalize therapeutic decisions.展开更多
Multifunctional photodetectors boost the development of traditional optical communication technology and emerging artificial intelligence fields, such as robotics and autonomous driving. However, the current implement...Multifunctional photodetectors boost the development of traditional optical communication technology and emerging artificial intelligence fields, such as robotics and autonomous driving. However, the current implementation of multifunctional detectors is based on the physical combination of optical lenses, gratings, and multiple photodetectors, the large size and its complex structure hinder the miniaturization, lightweight, and integration of devices. In contrast, perovskite materials have achieved remarkable progress in the field of multifunctional photodetectors due to their diverse crystal structures, simple morphology manipulation, and excellent optoelectronic properties. In this review, we first overview the crystal structures and morphology manipulation techniques of perovskite materials and then summarize the working mechanism and performance parameters of multifunctional photodetectors. Furthermore, the fabrication strategies of multifunctional perovskite photodetectors and their advancements are highlighted, including polarized light detection, spectral detection, angle-sensing detection, and selfpowered detection. Finally, the existing problems of multifunctional detectors and the perspectives of their future development are presented.展开更多
Metal superhydrophobic surfaces with anisotropic wettability and adhesion have become more and more important due to their promising applications. Herein, we report a new fabrication strategy through a combination of ...Metal superhydrophobic surfaces with anisotropic wettability and adhesion have become more and more important due to their promising applications. Herein, we report a new fabrication strategy through a combination of pulsed laser ablation and low-temperature annealing post-processing. An inclined cone structure array is made on stainless steel surfaces, and then 120 °C low-temperature annealing is applied. Such surface displays excellent mechanical durability and anisotropic superhydrophobicity. It is demonstrated experimentally that the contact angle of water droplets on the surface is different along the parallel(167° ±2°) and perpendicular directions(157° ±2°) of the inclined cone structure. The sliding behaviors of water droplets and mechanical durability of the inclined cone structures are studied. These surfaces obtained in a short time with environmentally friendly fabrication can be applied in industries for water harvesting, droplet manipulation, and pipeline transportation.展开更多
Titanium(Ti)and its alloys have been extensively explored for treating load-bearing bone defects.How-ever,high-stress shielding,weak osteogenic activity,and insufficient vascularization remain key chal-lenges for the ...Titanium(Ti)and its alloys have been extensively explored for treating load-bearing bone defects.How-ever,high-stress shielding,weak osteogenic activity,and insufficient vascularization remain key chal-lenges for the long-term clinical outcomes of Ti-based implants.Herein,inspired by structural and func-tional cues of bone regeneration,a silicon-doped nano-hydroxyapatite(nSiHA)/titanium dioxide(TiO_(2))composite coating with a hierarchical micro/nano-network structure is constructed on the surface of a 3D-printed porous Ti scaffold via a combined strategy of acid-alkali(AA)treatment and electrochemi-cal deposition technique,which not only endows the scaffold with excellent osteoinduction ability but can also effectively immobilize and release vascular endothelial growth factor(VEGF).The results of the in vitro cell experiments show that the functionalized Ti scaffold significantly promotes osteogenesis in bone marrow mesenchymal stem cells(BMSCs)and angiogenesis in human umbilical vein endothelial cells(HUVECs)by activating the extracellular signal-regulated protein kinase(ERK)and HIF-1αsignaling pathways.After being implanted into a rat femoral condyle defect model,the functionalized Ti scaffold can induce in situ vascularized bone regeneration by orchestrating the two coupled processes of angio-genesis and osteogenesis.These findings indicate that the functionalized Ti scaffold has great potential in bone tissue regeneration and is a promising candidate for load-bearing bone defect repair.展开更多
Transdermal delivery is an attractive alternative, but it is limited by the extremely low permeability of skin. To solve this problem, a novel means--micro needle array based on micro electro-mechanical system （MEMS...Transdermal delivery is an attractive alternative, but it is limited by the extremely low permeability of skin. To solve this problem, a novel means--micro needle array based on micro electro-mechanical system （MEMS） technology, is provided to increase permeability of human skin with efficiency, safety and painless delivery. The fabrication method consists of a sequence of deep-reactive ion etching （DRIE）, anisotropic wet etching and conformal thin film deposition. The novel technology can enable the realization of micro fabricated micro needle array on a flexible silicon substrate. The micro needle array can be mounted on non-planar surface or even on flexible objects such as a human fingers and arms. The fabricated hollow wall straight micro needles are 200 μm in length, 30 μm inner diameter, and 50 μm outer diameter with 250 μm center-to-center spacing. Flow rate test proves that the polymeric base construction is important to function of micro needles array in package. Glucose solvent tests show that surface tension is the dominant force to affect the characters of flow in micro needles channel.展开更多
Micro channel of T2 copper were molding through electronic-magnetic forming experiments.Laser scanning confocal microscope and contourgraph were used to measure the section profile and sheet thickness.The effects of v...Micro channel of T2 copper were molding through electronic-magnetic forming experiments.Laser scanning confocal microscope and contourgraph were used to measure the section profile and sheet thickness.The effects of voltage,shape of channel and discharge cycles on laws of metal flow were studied.Results showed that forming depth of micro channel and thinning of sheet thickness increased as the increasing of the voltage.Mold-filling capacity of components formed by two molds with different structures had been increased when the voltage was increased.Mold with semicircle structure facilitate the material flow and the forming depth of parts was relative large.Semicircle structure was better than taper structure in mold-filling capacity.A number of small pulse discharges can improve the forming quality and deformation,but local thinning in sheet metal leads to non-uniform distribution of thickness.展开更多
This paper presents a probe-based force-controlled nanoindentation method to fabricate ordered micro/nanostructures.Both the experimental and finite element simulation approaches are employed to investigate the influe...This paper presents a probe-based force-controlled nanoindentation method to fabricate ordered micro/nanostructures.Both the experimental and finite element simulation approaches are employed to investigate the influence of the interval between the adjacent indentations and the rotation angle of the probe on the formed micro/nanostructures.The non-contacting part between indenter and the sample material and the height of the material pile-up are two competing factors to determine the depth relationship between the adjacent indentations.For the one array indentations,nanostructures with good depth consistency and periodicity can be formed after the depth of the indentation becoming stable,and the variation of the rotation angle results in the large difference between the morphology of the formed nanostructures at the bottom of the one array indentation.In addition,for the indentation arrays,the nanostructures with good consistency and periodicity of the shape and depth can be generated with the spacing greater than 1μm.Finally,Raman tests are also carried out based on the obtained ordered micro/nanostructures with Rhodamine probe molecule.The indentation arrays with a smaller spacing lead to better the enhancement effect of the substrate,which has the potential applications in the fields of biological or chemical molecular detection.展开更多
Most broadband microstrip antennae are implemented in the form of slot structure or laminate structure,which provide a broad impedance bandwidth and meanwhile bring large sidelobes and backlobes. A novel uni-planar co...Most broadband microstrip antennae are implemented in the form of slot structure or laminate structure,which provide a broad impedance bandwidth and meanwhile bring large sidelobes and backlobes. A novel uni-planar compact electromagnetic band-gap( EBG) structure is proposed, which shows excellent performance when applied to broadband stacked or aperture coupled microstrip array antennae. The test results indicate that,the directivity is effectively improved,and the front-to-back ratio is increased,and the thickness of the antenna is reduced. These improvements make this structure better used in airborne antennae.展开更多
In this study,the possibility of obtaining micro and nano-scaled Co/Ni bi-layered films by use of the electrochemical method was investigated.The electrodeposition process was performed with presence and absence of a ...In this study,the possibility of obtaining micro and nano-scaled Co/Ni bi-layered films by use of the electrochemical method was investigated.The electrodeposition process was performed with presence and absence of a uniform external magnetic field up to 1T to examine its influence on structure and morphology of the obtained thin films. Afterwards,each sample was annealed under high magnetic field with strength up to 12 T at 623 K,what allowed compare and determine the changes in morphology and structure,before and after heat treatment.The Co/Ni bi-layered thin films were deposited onto an indium-doped tin oxide(ITO)-coated conducting glass substrate from sulfate baths with boric acid as an additive.The results show drastic changes in the morphology between macro and nano-scaled films which were strongly affected by an introduction of the magnetic field to the electrodeposition process.The annealing process allowed to determine the nucleus transition and showed that under the high temperature treatment it is possible to control the growth mode as well as the phase composition changes.展开更多
We report the synthesis and electrochemical sodium storage of cobalt disulfide （COS2） with various micro/nano-structures. CoS2 with microscale sizes are either assembled by nanoparticles （P-CoS2） via a facile solv...We report the synthesis and electrochemical sodium storage of cobalt disulfide （COS2） with various micro/nano-structures. CoS2 with microscale sizes are either assembled by nanoparticles （P-CoS2） via a facile solvothermal route or nano- octahedrons constructed solid （O-COS2） and hollow microstructures （H-CoS2） fabricated by hydrothermal methods. Among three morphologies, H-CoS2 exhibits the largest discharge capacities and best rate performance as anode of sodium-ion batteries （SIBs）. Furthermore, H-CoS2 delivers a capacity of 690 mA.h.g 1 at 1 A·g 1 after 100 cycles in a potential range of 0.1-3.0 V, and N240 mA.h.g-1 over 800 cycles in the potential window of 1.0-3.0 V. This cycling difference mainly lies in the two discharge plateaus observed in 0.1-3.0 V and one discharge plateau in 1.0-3.0 V. To interpret the reactions, X-ray diffraction （XRD） and transmission electron microscopy （TEM） are applied. The results show that at the first plateau around 1.4 V, the insertion reaction （COS2 ＋ xNa＊ ＋ xe NaxCoS2） Occurs; while at the second plateau around 0.6 V, the conversion reaction （NaxCoS2 ＋ （4 - x） Na＋ ＋ （4 - x）e -~ Co ＋ 2Na2S） takes place. This provides insights for electrochemical sodium storage of CoS2 as the anode of SIBs.展开更多
Implant-associated infections are generally difficult to cure owing to the bacterial antibiotic resistance which is attributed to the widespread usage of antibiotics.Given the global threat and increasing influence of...Implant-associated infections are generally difficult to cure owing to the bacterial antibiotic resistance which is attributed to the widespread usage of antibiotics.Given the global threat and increasing influence of antibiotic resistance,there is an urgent demand to explore novel antibacterial strategies other than using antibiotics.Recently,using a certain surface topography to provide a more persistent antibacterial solution attracts more and more attention.However,the clinical application of biomimetic nano-pillar array is not satisfactory,mainly because its antibacterial ability against Gram-positive strain is not good enough.Thus,the pillar array should be equipped with other antibacterial agents to fulfill the bacteriostatic and bactericidal requirements of clinical application.Here,we designed a novel model substrate which was a combination of periodic micro/nano-pillar array and TiO2 for basically understanding the topographical bacteriostatic effects of periodic micro/nano-pillar array and the photocatalytic bactericidal activity of TiO2.Such innovation may potentially exert the synergistic effects by integrating the persistent topographical antibacterial activity and the non-invasive X-ray induced photocatalytic antibacterial property of TiO2 to combat against antibiotic-resistant implant-associated infections.First,to separately verify the topographical antibacterial activity of TiO2 periodic micro/nano-pillar array,we systematically investigated its effects on bacterial adhesion,growth,proliferation,and viability in the dark without involving the photocatalysis of TiO2.The pillar array with sub-micron motif size can significantly inhibit the adhesion,growth,and proliferation of Staphylococcus aureus(S.aureus)and Escherichia coli(E.coli).Such antibacterial ability is mainly attributed to a spatial confinement size-effect and limited contact area availability generated by the special topography of pillar array.Moreover,the pillar array is not lethal to S.aureus and E.coli in 24 h.Then,the X-ray induced photocatalytic antibacterial property of TiO2 periodic micro/nano-pillar array in vitro and in vivo will be systematically studied in a future work.This study could shed light on the direction of surface topography design for future medical implants to combat against antibiotic-resistant implant-associated infections without using antibiotics.展开更多
Electrohydrodynamicjet （E-Jet） is an approach to the fabrication of micro/nano-structures by the use of electrical forces. In this process, the liquid is subjected to electrical and mechanical forces to form a liqui...Electrohydrodynamicjet （E-Jet） is an approach to the fabrication of micro/nano-structures by the use of electrical forces. In this process, the liquid is subjected to electrical and mechanical forces to form a liquid jet, which is further disintegrated into droplets. The major advantage of the E-Jet technique is that the sizes of the jet formed can be at the nanoscale far smaller than the nozzle size, which can realize high printing resolution with less risk of nozzle blockage. The E-Jet technique, which mainly includes E-Jet deposition and E-Jet printing, has a wide range of applications in the fabrication ofmicro/nano-structures for micro/nano-electromechanical system devices. This tech- nique is also considered a micro/nano-fabrication method with a great potential for commercial use. This study mainly reviews the E-Jet deposition/printing fundamentals, fabrication process, and applications.展开更多
Hydrogels, composed mainly of water trapped in three dimensional cross-linked polymer networks, have been widely utilized to construct underwater superoleophobic surfaces. However, the swelling nature and instability ...Hydrogels, composed mainly of water trapped in three dimensional cross-linked polymer networks, have been widely utilized to construct underwater superoleophobic surfaces. However, the swelling nature and instability of hydrogels under complex marine environment will weaken their underwater superoleophobicity. Herein, we synthesize structured poly （2-hydroxyethylmethacrylate） （PHEMA） hydrogels by using sandpaper as templates. The robust non-swelling of PHEMA hydrogel ensures that micro/nano-structures on the surface of PHEMA hydrogels can be well maintained. Moreover, when roughness Ra of about 3-4 bun, the surface has superior oil-repellency. Additionally, even after immersing in seawater for one-month, their breaking strength and toughness can be well kept. The non-swellable hydrogels with long-term stable under seawater superoleophobicity will promote the development of robust superoleophobic materials in marine antifouling coatings, biomedical devices and oil/water separation.展开更多
Timely monitoring of anesthesia status during surgery is important to prevent an overdose of isoflurane anesthesia.Therefore,in-depth studies of the neural mechanisms of anesthetics are warranted.Hippocampal CA1 plays...Timely monitoring of anesthesia status during surgery is important to prevent an overdose of isoflurane anesthesia.Therefore,in-depth studies of the neural mechanisms of anesthetics are warranted.Hippocampal CA1 plays an important role during anesthesia.Currently,a high spatiotemporal resolution microdevice technology for the accurate detection of deep brain nuclei is lacking.In this research,four-shank 32-channel implantable microelectrode arrays(MEAs)were developed for the real-time recording of single-cell level neural information in rat hippocampal CA1.Platinum nanoparticles were modified onto the microelectrodes to substantially enhance the electrical properties of the microelectrode arrays.The modified MEAs exhibited low impedance(11.5±1 kΩ)and small phase delay(-18.5°±2.54°),which enabled the MEAs to record single-cell level neural information with a high signal-to-noise ratio.The MEAs were implanted into the CA1 nuclei of the anesthetized rats,and the electrophysiological signals were recorded under different degrees of anesthesia mediated by low-dose concentrations of isoflurane.The recorded signals were analyzed in depth.Isoflurane caused an inhibition of spike firing rate in hippocampal CA1 neurons,while inducing low-frequency oscillations in CA1,thus enhancing the low-frequency power of local field potentials.In this manner,the spike firing rate and the power of local field potentials in CA1 could characterize the degree of isoflurane anesthesia.The present study provides a technical tool to study the neural mechanisms of isoflurane anesthesia and a research method for monitoring the depth of isoflurane anesthesia in clinical practice.展开更多
Owing to its unique ability to capture volumetric tomographic information with a single light flash,optoacoustic(OA)tomography has recently demonstrated ultrafast imaging speeds ultimately limited by the ultrasound ti...Owing to its unique ability to capture volumetric tomographic information with a single light flash,optoacoustic(OA)tomography has recently demonstrated ultrafast imaging speeds ultimately limited by the ultrasound time-of-flight.The method's scalability and the achievable spatial resolution are yet limited by the narrow bandwidth of piezo-composite arrays currently employed for OA signal detection.Here we report on the first implementation of high-density spherical array technology based on flexible polyvinylidene difluoride films featuring ultrawideband(0.3-40 MHz)sub mm^(2)area elements,thus enabling real-time multi-scale volumetric imaging with 22-35μm spatial resolution,superior image fidelity and over an order of magnitude signal-to-noise enhancement compared to piezo-composite equivalents.We further demonstrate five-dimensional(spectroscopic,time-resolved,volumetric)imaging capabilities by visualizing fast stimulus-evoked cerebral oxygenation changes in mice and performing real-time functional angiography of deep human micro-vasculature.The new technology thus leverages the true potential of OA for quantitative high-resolution visualization of rapid bio-dynamics across scales.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.51771233,52071346 and 51604104)China Postdoctoral Science Foundation(Grant No.2018M633164)+1 种基金Innovation-oriented Advanced Technology and Industrial Technology Program Project of Hunan Province(Grant No.2020SK2017)Guangdong Basic and Applied Basic Research Foundation(Grant No.2019A1515110736)。
文摘Modulating the activation state and degree of macrophages still remains as a challenge for the topographical design of Ti-based implants.In this work,micro/nano-structured coatings were prepared on Ti substrates by micro-arc oxidation(MAO)and subsequent hydrothermal(HT)treatment.By varying the HT conditions,plate-like nano-structures with an average length of 80,440 or 780 nm were obtained on MAO-prepared micro-topographical surfaces.Depending on the dimensional features of nano-plates,the specimens were noted as Micro,Micro/Nano-180,Micro/Nano-440 and Micro/Nano-780,respectively.The in vitro results showed that the activation state and degree of macrophages could be effectively modulated by the micro/nano-structured surfaces with various dimensional features.Compared to the Micro surface,the Micro/Nano-180 surface activated both M1 and M2 phenotype in macrophages,while the Micro/Nano-440 and Micro/Nano-780 surfaces polarized macrophages to their M1 phenotype.The activation degree of M1 macrophages followed the trend:Micro<Micro/Nano-180<Micro/Nano-440<Micro/Nano-780.However,the osteogenic potential of the activated macrophages in response to various surfaces were in the order:Micro≈Micro/Nano-780<Micro/Nano-180<Micro/Nano-440.Together,the findings presented in this work indicate that engineering nano-structures with controllable dimensional features is a promising strategy to modulate macrophage activation state and degree.In addition,it is essential to determine the appropriate activation degree of M1 macrophages for enhanced osteogenesis.
文摘A novel micro heat pipe array was used in solar panel cooling. Both of air-cooling and water-cooling conditions under nature convection condition were investigated in this paper. Compared with the ordinary solar panel, the maximum difference of the photoelectric conversion efficiency is 2.6%, the temperature reduces maximally by 4.7℃, the output power increases maximally by 8.4% for the solar panel with heat pipe using air-cooling, when the daily radiation value is 26.3 MJ. Compared with the solar panel with heat pipe using air-cooling, the maximum difference of the photoelectric conversion efficiency is 3%, the temperature reduces maximally by 8℃, the output power increases maximally by 13.9% for the solar panel with heat pipe using water-cooling, when the daily radiation value is 21.9 MJ.
文摘Digital micro-thruster arrays can be used for special missions of micro/nano-satellites with the requirements of high precision and small impulse.This paper presents a novel control allocation algorithm for the digital micro-thruster array,namely status graph based control allocation(SGBCA)algorithm,which aims at finding the optimal micro thrusters combination scheme to realize the sequential control synthesis for micro/nano-satellite during real-time orbit control tasks.A mathematical model is set up for the control allocation of this multivariate over-actuated system.Through dividing thrusters into disjoint segments by offline calculation and combining segments dynamically online to provide a sequence of the required impulse for the micro/nano-satellite,the time complexity of the control allocation algorithm decreases significantly.All levels of impulse can be generated by the digital micro thruster arrays and the service life of the arrays can be extended using the segment converting strategy proposed in this paper.The simulation indicates that the algorithm can satisfy the requirements of real-time orbit control for micro/nano-satellites.
文摘Recently,the possibility of a disaster due to the improper use of highly toxic gases which are known as agents throughout the world has been increased.Therefore,the development of technology for countermeasure against CWA has been highly demanded.In this study,thick film SnO_2-based gas sensing devices were prepared and the sensing properties for the four different kinds of simulants such as dimethyl methyl phosphonate (DMMP),acetonitrile,dichloromethane and dipropylene glycol methyl ether have been investigated.And a micro sensor array consists of six devices was prepared using MEMS technology to provide high selective and reliable sensing system for the detection of chemical warfare agents.The micro gas sensor array prepared showed good sensitivity and selectivity to CWA.
基金supported by the 11th Five-Year Plan under Grant No. 11001030203
文摘An uncommon fractal construction method is applied in the microwave element design. A novel fractal defected ground structure （DGS） based on micro electro-mechanical system （MEMS） is proposed. The size of this novel fractal DGS can achieve 86% size reduction compared with the conventional dumbbell type DGS. This novel fractal DGS is used in the miniaturization design of L-band microstrip antenna array. The simulation result shows that this novel fractal DGS can effectively reduce the mutual coupling between the antenna elements, so it is helpful to the miniaturization of microstrip array, namely the approximately same gain value can be achieved with the shorter distance between elements.
文摘Aim of the study: Immunohistochemical evaluation of hormone receptors, Her2/neu, CK5/6, E-cadherin, beta-catenin, p53 and PTEN on Tissue Micro Array (TMA) of 46 Moroccan invasive breast carcinomas. Materials and Methods: The cases comprised 40 invasive ductal carcinomas, 4 invasive lobular carcinomas, 1 mixed carcinoma and 1 invasive colloid carcinoma. TMA paraffin blocs were prepared with the Beecher manual arrayer and immunostaining was performed using standard immunoperoxidase techniques. Results: 58.69% of the cases were ER positive. 43.18% (19/44) were triple negative breast cancers (TNBC) of which 15.78% (3/19) were of the basal phenotype expressing CK5/6. On the other hand, 72.22% (13/18) of the TNBC cases were IDC grade 3. Of the 18 IDC grade 3, 22.22% (4/18) were CK5/6 positive. 41.30% and 10.86% of the cases showed reduced expression of E-cadherin and beta-catenin respectively. Beta-catenin nuclear and cytoplasmic staining was noted in 20% and 97.82% respectively. p53 was overexpressed in 10.86% of the cases whereas PTEN loss or reduced expression was noted in 86.95% of the cases. Conclusion: The aim of our study was to introduce TMA technique in our hospital which is considered a reference institution for cancer in Morocco. Although no statistical study was performed to look for any significance of the results obtained, we found good correlation with some of the data in the literature. To determine the molecular characteristics, if any, of the Moroccan patient, larger multidisciplinary and prospective studies would be interesting in the aim to personalize therapeutic decisions.
基金supported financially by the National Key R&D Program of China (Nos. 2018YFA0208501 and 2018YFA0703200)the National Natural Science Foundation of China (NSFC, Nos. 52103236, 91963212, 21875260)Beijing National Laboratory for Molecular Sciences (No. BNLMSCXXM-202005)。
文摘Multifunctional photodetectors boost the development of traditional optical communication technology and emerging artificial intelligence fields, such as robotics and autonomous driving. However, the current implementation of multifunctional detectors is based on the physical combination of optical lenses, gratings, and multiple photodetectors, the large size and its complex structure hinder the miniaturization, lightweight, and integration of devices. In contrast, perovskite materials have achieved remarkable progress in the field of multifunctional photodetectors due to their diverse crystal structures, simple morphology manipulation, and excellent optoelectronic properties. In this review, we first overview the crystal structures and morphology manipulation techniques of perovskite materials and then summarize the working mechanism and performance parameters of multifunctional photodetectors. Furthermore, the fabrication strategies of multifunctional perovskite photodetectors and their advancements are highlighted, including polarized light detection, spectral detection, angle-sensing detection, and selfpowered detection. Finally, the existing problems of multifunctional detectors and the perspectives of their future development are presented.
基金Project(A19C2a0019) supported by the Advanced Remanufacturing and Technology Centre (ARTC) under its RIE2020 Advanced Manufacturing and Engineering (AME) IAF PP,Singapore。
文摘Metal superhydrophobic surfaces with anisotropic wettability and adhesion have become more and more important due to their promising applications. Herein, we report a new fabrication strategy through a combination of pulsed laser ablation and low-temperature annealing post-processing. An inclined cone structure array is made on stainless steel surfaces, and then 120 °C low-temperature annealing is applied. Such surface displays excellent mechanical durability and anisotropic superhydrophobicity. It is demonstrated experimentally that the contact angle of water droplets on the surface is different along the parallel(167° ±2°) and perpendicular directions(157° ±2°) of the inclined cone structure. The sliding behaviors of water droplets and mechanical durability of the inclined cone structures are studied. These surfaces obtained in a short time with environmentally friendly fabrication can be applied in industries for water harvesting, droplet manipulation, and pipeline transportation.
基金supported by the Sichuan Science and Technology Program (Nos.2019JDTD0008 and 2022YFG0109)the China Postdoctoral Science Foundation (Nos.2021M692316 and 2020TQ0218).
文摘Titanium(Ti)and its alloys have been extensively explored for treating load-bearing bone defects.How-ever,high-stress shielding,weak osteogenic activity,and insufficient vascularization remain key chal-lenges for the long-term clinical outcomes of Ti-based implants.Herein,inspired by structural and func-tional cues of bone regeneration,a silicon-doped nano-hydroxyapatite(nSiHA)/titanium dioxide(TiO_(2))composite coating with a hierarchical micro/nano-network structure is constructed on the surface of a 3D-printed porous Ti scaffold via a combined strategy of acid-alkali(AA)treatment and electrochemi-cal deposition technique,which not only endows the scaffold with excellent osteoinduction ability but can also effectively immobilize and release vascular endothelial growth factor(VEGF).The results of the in vitro cell experiments show that the functionalized Ti scaffold significantly promotes osteogenesis in bone marrow mesenchymal stem cells(BMSCs)and angiogenesis in human umbilical vein endothelial cells(HUVECs)by activating the extracellular signal-regulated protein kinase(ERK)and HIF-1αsignaling pathways.After being implanted into a rat femoral condyle defect model,the functionalized Ti scaffold can induce in situ vascularized bone regeneration by orchestrating the two coupled processes of angio-genesis and osteogenesis.These findings indicate that the functionalized Ti scaffold has great potential in bone tissue regeneration and is a promising candidate for load-bearing bone defect repair.
基金This project is supported by National Hi-tech Research and Development Program of China(863 Program, No.2005AA404220).
文摘Transdermal delivery is an attractive alternative, but it is limited by the extremely low permeability of skin. To solve this problem, a novel means--micro needle array based on micro electro-mechanical system （MEMS） technology, is provided to increase permeability of human skin with efficiency, safety and painless delivery. The fabrication method consists of a sequence of deep-reactive ion etching （DRIE）, anisotropic wet etching and conformal thin film deposition. The novel technology can enable the realization of micro fabricated micro needle array on a flexible silicon substrate. The micro needle array can be mounted on non-planar surface or even on flexible objects such as a human fingers and arms. The fabricated hollow wall straight micro needles are 200 μm in length, 30 μm inner diameter, and 50 μm outer diameter with 250 μm center-to-center spacing. Flow rate test proves that the polymeric base construction is important to function of micro needles array in package. Glucose solvent tests show that surface tension is the dominant force to affect the characters of flow in micro needles channel.
基金Item Sponsored by the National Natural Science Foundation of China[No.5083500250805035]
文摘Micro channel of T2 copper were molding through electronic-magnetic forming experiments.Laser scanning confocal microscope and contourgraph were used to measure the section profile and sheet thickness.The effects of voltage,shape of channel and discharge cycles on laws of metal flow were studied.Results showed that forming depth of micro channel and thinning of sheet thickness increased as the increasing of the voltage.Mold-filling capacity of components formed by two molds with different structures had been increased when the voltage was increased.Mold with semicircle structure facilitate the material flow and the forming depth of parts was relative large.Semicircle structure was better than taper structure in mold-filling capacity.A number of small pulse discharges can improve the forming quality and deformation,but local thinning in sheet metal leads to non-uniform distribution of thickness.
基金National Natural Science Foundation of China(Grant Nos.52035004,51911530206,51905047)Heilongjiang Provincial Natural Science Foundation of China(Grant No.YQ2020E015)+1 种基金Self-Planned Task of State Key Laboratory of Robotics and System(HIT)(Grant No.SKLRS202001C)Young Elite Scientist Sponsorship Program by CAST(Grant No.YESS20200155).
文摘This paper presents a probe-based force-controlled nanoindentation method to fabricate ordered micro/nanostructures.Both the experimental and finite element simulation approaches are employed to investigate the influence of the interval between the adjacent indentations and the rotation angle of the probe on the formed micro/nanostructures.The non-contacting part between indenter and the sample material and the height of the material pile-up are two competing factors to determine the depth relationship between the adjacent indentations.For the one array indentations,nanostructures with good depth consistency and periodicity can be formed after the depth of the indentation becoming stable,and the variation of the rotation angle results in the large difference between the morphology of the formed nanostructures at the bottom of the one array indentation.In addition,for the indentation arrays,the nanostructures with good consistency and periodicity of the shape and depth can be generated with the spacing greater than 1μm.Finally,Raman tests are also carried out based on the obtained ordered micro/nanostructures with Rhodamine probe molecule.The indentation arrays with a smaller spacing lead to better the enhancement effect of the substrate,which has the potential applications in the fields of biological or chemical molecular detection.
基金Sponsored by the Fujian Education Department(Grant No.JA13183)the Fujian Provincial Department of Science and Technology(Grant No.2013H0035)
文摘Most broadband microstrip antennae are implemented in the form of slot structure or laminate structure,which provide a broad impedance bandwidth and meanwhile bring large sidelobes and backlobes. A novel uni-planar compact electromagnetic band-gap( EBG) structure is proposed, which shows excellent performance when applied to broadband stacked or aperture coupled microstrip array antennae. The test results indicate that,the directivity is effectively improved,and the front-to-back ratio is increased,and the thickness of the antenna is reduced. These improvements make this structure better used in airborne antennae.
基金Item Sponsored by National Natural Science Foundation of China(51061130557,51101032)French ANR,Champagne-Ardenne Region Council and Pole MATERALIA(Programme COMAGNET,Grant No.2010-INTB-903-01)
文摘In this study,the possibility of obtaining micro and nano-scaled Co/Ni bi-layered films by use of the electrochemical method was investigated.The electrodeposition process was performed with presence and absence of a uniform external magnetic field up to 1T to examine its influence on structure and morphology of the obtained thin films. Afterwards,each sample was annealed under high magnetic field with strength up to 12 T at 623 K,what allowed compare and determine the changes in morphology and structure,before and after heat treatment.The Co/Ni bi-layered thin films were deposited onto an indium-doped tin oxide(ITO)-coated conducting glass substrate from sulfate baths with boric acid as an additive.The results show drastic changes in the morphology between macro and nano-scaled films which were strongly affected by an introduction of the magnetic field to the electrodeposition process.The annealing process allowed to determine the nucleus transition and showed that under the high temperature treatment it is possible to control the growth mode as well as the phase composition changes.
基金This work was supported by the National Natural Science Foundation of China （No. 51231003） and MOE （Nos. B12015 and IRT13R30）.
文摘We report the synthesis and electrochemical sodium storage of cobalt disulfide （COS2） with various micro/nano-structures. CoS2 with microscale sizes are either assembled by nanoparticles （P-CoS2） via a facile solvothermal route or nano- octahedrons constructed solid （O-COS2） and hollow microstructures （H-CoS2） fabricated by hydrothermal methods. Among three morphologies, H-CoS2 exhibits the largest discharge capacities and best rate performance as anode of sodium-ion batteries （SIBs）. Furthermore, H-CoS2 delivers a capacity of 690 mA.h.g 1 at 1 A·g 1 after 100 cycles in a potential range of 0.1-3.0 V, and N240 mA.h.g-1 over 800 cycles in the potential window of 1.0-3.0 V. This cycling difference mainly lies in the two discharge plateaus observed in 0.1-3.0 V and one discharge plateau in 1.0-3.0 V. To interpret the reactions, X-ray diffraction （XRD） and transmission electron microscopy （TEM） are applied. The results show that at the first plateau around 1.4 V, the insertion reaction （COS2 ＋ xNa＊ ＋ xe NaxCoS2） Occurs; while at the second plateau around 0.6 V, the conversion reaction （NaxCoS2 ＋ （4 - x） Na＋ ＋ （4 - x）e -~ Co ＋ 2Na2S） takes place. This provides insights for electrochemical sodium storage of CoS2 as the anode of SIBs.
基金supported by the Natural Science Foundation of Tianjin(General Program,No.18JCYBJC19500)the Independent Innovation Fund of Tianjin University(No.2019XZS-0014)the Research Grants Council of Hong Kong(No.HKUST615408).
文摘Implant-associated infections are generally difficult to cure owing to the bacterial antibiotic resistance which is attributed to the widespread usage of antibiotics.Given the global threat and increasing influence of antibiotic resistance,there is an urgent demand to explore novel antibacterial strategies other than using antibiotics.Recently,using a certain surface topography to provide a more persistent antibacterial solution attracts more and more attention.However,the clinical application of biomimetic nano-pillar array is not satisfactory,mainly because its antibacterial ability against Gram-positive strain is not good enough.Thus,the pillar array should be equipped with other antibacterial agents to fulfill the bacteriostatic and bactericidal requirements of clinical application.Here,we designed a novel model substrate which was a combination of periodic micro/nano-pillar array and TiO2 for basically understanding the topographical bacteriostatic effects of periodic micro/nano-pillar array and the photocatalytic bactericidal activity of TiO2.Such innovation may potentially exert the synergistic effects by integrating the persistent topographical antibacterial activity and the non-invasive X-ray induced photocatalytic antibacterial property of TiO2 to combat against antibiotic-resistant implant-associated infections.First,to separately verify the topographical antibacterial activity of TiO2 periodic micro/nano-pillar array,we systematically investigated its effects on bacterial adhesion,growth,proliferation,and viability in the dark without involving the photocatalysis of TiO2.The pillar array with sub-micron motif size can significantly inhibit the adhesion,growth,and proliferation of Staphylococcus aureus(S.aureus)and Escherichia coli(E.coli).Such antibacterial ability is mainly attributed to a spatial confinement size-effect and limited contact area availability generated by the special topography of pillar array.Moreover,the pillar array is not lethal to S.aureus and E.coli in 24 h.Then,the X-ray induced photocatalytic antibacterial property of TiO2 periodic micro/nano-pillar array in vitro and in vivo will be systematically studied in a future work.This study could shed light on the direction of surface topography design for future medical implants to combat against antibiotic-resistant implant-associated infections without using antibiotics.
文摘Electrohydrodynamicjet （E-Jet） is an approach to the fabrication of micro/nano-structures by the use of electrical forces. In this process, the liquid is subjected to electrical and mechanical forces to form a liquid jet, which is further disintegrated into droplets. The major advantage of the E-Jet technique is that the sizes of the jet formed can be at the nanoscale far smaller than the nozzle size, which can realize high printing resolution with less risk of nozzle blockage. The E-Jet technique, which mainly includes E-Jet deposition and E-Jet printing, has a wide range of applications in the fabrication ofmicro/nano-structures for micro/nano-electromechanical system devices. This tech- nique is also considered a micro/nano-fabrication method with a great potential for commercial use. This study mainly reviews the E-Jet deposition/printing fundamentals, fabrication process, and applications.
基金supported by the National Natural Science Foundation (21574004, 21421061, 21434009, 21301036)the National Research Fund for Fundamental Key Projects (2012CB933800)+4 种基金the Fundamental Research Funds for the Central Universitiesthe National “Young Thousand Talents Program”Xiamen Southern Oceanographic Center (14GQT61HJ31)the Key Research Program of the Chinese Academy of Sciences (KJZD-EW-M01, KJZD-EW-M03)the Program of Introducing Talents of Discipline to Universities of China (B14009)
文摘Hydrogels, composed mainly of water trapped in three dimensional cross-linked polymer networks, have been widely utilized to construct underwater superoleophobic surfaces. However, the swelling nature and instability of hydrogels under complex marine environment will weaken their underwater superoleophobicity. Herein, we synthesize structured poly （2-hydroxyethylmethacrylate） （PHEMA） hydrogels by using sandpaper as templates. The robust non-swelling of PHEMA hydrogel ensures that micro/nano-structures on the surface of PHEMA hydrogels can be well maintained. Moreover, when roughness Ra of about 3-4 bun, the surface has superior oil-repellency. Additionally, even after immersing in seawater for one-month, their breaking strength and toughness can be well kept. The non-swellable hydrogels with long-term stable under seawater superoleophobicity will promote the development of robust superoleophobic materials in marine antifouling coatings, biomedical devices and oil/water separation.
基金sponsored by the National Natural Science Foundation of China(T2293731,61960206012,62121003,62171434,61971400,61975206,and 61973292)the Scientific Instrument Developing Project of the Chinese Academy of Sciences(GJJSTD20210004)+1 种基金the National Key Research and Development Program(2022YFC2402501,2022YFB3205602)Major Program of Scientific and Technical Innovation 2030(2021ZD0201603).
文摘Timely monitoring of anesthesia status during surgery is important to prevent an overdose of isoflurane anesthesia.Therefore,in-depth studies of the neural mechanisms of anesthetics are warranted.Hippocampal CA1 plays an important role during anesthesia.Currently,a high spatiotemporal resolution microdevice technology for the accurate detection of deep brain nuclei is lacking.In this research,four-shank 32-channel implantable microelectrode arrays(MEAs)were developed for the real-time recording of single-cell level neural information in rat hippocampal CA1.Platinum nanoparticles were modified onto the microelectrodes to substantially enhance the electrical properties of the microelectrode arrays.The modified MEAs exhibited low impedance(11.5±1 kΩ)and small phase delay(-18.5°±2.54°),which enabled the MEAs to record single-cell level neural information with a high signal-to-noise ratio.The MEAs were implanted into the CA1 nuclei of the anesthetized rats,and the electrophysiological signals were recorded under different degrees of anesthesia mediated by low-dose concentrations of isoflurane.The recorded signals were analyzed in depth.Isoflurane caused an inhibition of spike firing rate in hippocampal CA1 neurons,while inducing low-frequency oscillations in CA1,thus enhancing the low-frequency power of local field potentials.In this manner,the spike firing rate and the power of local field potentials in CA1 could characterize the degree of isoflurane anesthesia.The present study provides a technical tool to study the neural mechanisms of isoflurane anesthesia and a research method for monitoring the depth of isoflurane anesthesia in clinical practice.
基金supported by the Swiss National Science Foundation(310030_192757)the European Research Council(ERC-2015-CoG-682379)+2 种基金The development of the ultra-wideband ultrasonic antenna and the in vivo optoacoustic experiments were supported by the grants from the Russian Science Foundation(18-45-06006)the Helmholtz Association(HRSF-0020)The development of numerical algorithms for enhancement of angiographic optoacoustic images was partially supported by the grant from the Russian Science Foundation(19-75-10055)。
文摘Owing to its unique ability to capture volumetric tomographic information with a single light flash,optoacoustic(OA)tomography has recently demonstrated ultrafast imaging speeds ultimately limited by the ultrasound time-of-flight.The method's scalability and the achievable spatial resolution are yet limited by the narrow bandwidth of piezo-composite arrays currently employed for OA signal detection.Here we report on the first implementation of high-density spherical array technology based on flexible polyvinylidene difluoride films featuring ultrawideband(0.3-40 MHz)sub mm^(2)area elements,thus enabling real-time multi-scale volumetric imaging with 22-35μm spatial resolution,superior image fidelity and over an order of magnitude signal-to-noise enhancement compared to piezo-composite equivalents.We further demonstrate five-dimensional(spectroscopic,time-resolved,volumetric)imaging capabilities by visualizing fast stimulus-evoked cerebral oxygenation changes in mice and performing real-time functional angiography of deep human micro-vasculature.The new technology thus leverages the true potential of OA for quantitative high-resolution visualization of rapid bio-dynamics across scales.
