Conventional blood sampling for glucose detection is prone to cause pain and fails to continuously record glucose fluctuations in vivo.Continuous glucose monitoring based on implantable electrodes could induce pain an...Conventional blood sampling for glucose detection is prone to cause pain and fails to continuously record glucose fluctuations in vivo.Continuous glucose monitoring based on implantable electrodes could induce pain and potential tissue inflammation,and the presence of reactive oxygen species(ROS)due to inflammationmay affect glucose detection.Microneedle technology is less invasive,yet microneedle adhesion with skin tissue is limited.In this work,we developed a microarrow sensor array(MASA),which provided enhanced skin surface adhesion and enabled simultaneous detection of glucose and H_(2)O_(2)(representative of ROS)in interstitial fluid in vivo.The microarrows fabricated via laser micromachining were modified with functional coating and integrated into a patch of a three-dimensional(3D)microneedle array.Due to the arrow tip mechanically interlocking with the tissue,the microarrow array could better adhere to the skin surface after penetration into skin.The MASA was demonstrated to provide continuous in vivo monitoring of glucose and H_(2)O_(2) concentrations,with the detection of H_(2)O_(2) providing a valuable reference for assessing the inflammation state.Finally,the MASA was integrated into a monitoring system using custom circuitry.This work provides a promising tool for the stable and reliable monitoring of blood glucose in diabetic patients.展开更多
Modern medicine is increasingly interested in advanced sensors to detect and analyze biochemical indicators.Ion sensors based on potentiometric methods are a promising platform for monitoring physiological ions in bio...Modern medicine is increasingly interested in advanced sensors to detect and analyze biochemical indicators.Ion sensors based on potentiometric methods are a promising platform for monitoring physiological ions in biological subjects.Current semi-implantable devices are mainly based on single-parameter detection.Miniaturized semi-implantable electrodes for multiparameter sensing have more restrictions on the electrode size due to biocompatibility considerations,but reducing the electrode surface area could potentially limit electrode sensitivity.This study developed a semi-implantable device system comprising a multiplexed microfilament electrode cluster(MMEC)and a printed circuit board for real-time monitoring of intra-tissue K^(+),Ca^(2+),and Na^(+)concentrations.The electrode surface area was less important for the potentiometric sensing mechanism,suggesting the feasibility of using a tiny fiber-like electrode for potentiometric sensing.The MMEC device exhibited a broad linear response(K^(+):2–32 mmol/L;Ca^(2+):0.5–4 mmol/L;Na^(+):10–160 mmol/L),high sensitivity(about 20–45 mV/decade),temporal stability(>2weeks),and good selectivity(>80%)for the above ions.In vitro detection and in vivo subcutaneous and brain experiment results showed that the MMEC system exhibits good multi-ion monitoring performance in several complex environments.This work provides a platform for the continuous real-time monitoring of ion fluctuations in different situations and has implications for developing smart sensors to monitor human health.展开更多
With the advent of the 5G era and the rise of the Internet of Things,various sensors have received unprecedented attention,especially wearable and stretchable sensors in the healthcare field.Here,a stretchable,self-he...With the advent of the 5G era and the rise of the Internet of Things,various sensors have received unprecedented attention,especially wearable and stretchable sensors in the healthcare field.Here,a stretchable,self-healable,self-adhesive,and room-temperature oxygen sensor with excellent repeatability,a full concentration detection range(0-100%),low theoretical limit of detection(5.7 ppm),high sensitivity(0.2%/ppm),good linearity,excellent temperature,and humidity tolerances is fabricated by using polyacrylamide-chitosan(PAM-CS)double network(DN)organohydrogel as a novel transducing material.The PAM-CS DN organohydrogel is transformed from the PAM-CS composite hydrogel using a facile soaking and solvent replacement strategy.Compared with the pristine hydrogel,the DN organohydrogel displays greatly enhanced mechanical strength,moisture retention,freezing resistance,and sensitivity to oxygen.Notably,applying the tensile strain improves both the sensitivity and response speed of the organohydrogel-based oxygen sensor.Furthermore,the response to the same concentration of oxygen before and after self-healing is basically the same.Importantly,we propose an electrochemical reaction mechanism to explain the positive current shift of the oxygen sensor and corroborate this sensing mechanism through rationally designed experiments.The organohydrogel oxygen sensor is used to monitor human respiration in real-time,verifying the feasibility of its practical application.This work provides ideas for fabricating more stretchable,self-healable,self-adhesive,and high-performance gas sensors using ion-conducting organohydrogels.展开更多
Existing experimental results have shown that four types of physical mechanisms, namely, martensite transformation, martensite reorientation, magnetic domain wall motion and magnetization vector rotation, can be activ...Existing experimental results have shown that four types of physical mechanisms, namely, martensite transformation, martensite reorientation, magnetic domain wall motion and magnetization vector rotation, can be activated during the magneto-mechanical deformation of NiMnGa ferromagnetic shape memory alloy (FSMA) single crystals. In this work, based on irreversible thermodynamics, a three-dimensional (3D) single crystal constitutive model is constructed by considering the aforementioned four mechanisms simultaneously. Three types of internal variables, i.e., the volume fraction of each martensite variant, the volume fraction of magnetic domain in each variant and the deviation angle between the magnetization vector, and easy axis are introduced to characterize the magneto-mechanical state of the single crystals. The thermodynamic driving force of each mechanism and the thermodynamic constraints on the constitutive model are obtained from Clausius's dissipative inequality and constructed Gibbs free energy. Then, thermodynamically consistent kinetic equations for the four mechanisms are proposed, respectively. Finally, the ability of the proposed model to describe the magneto-mechanical deformation of NiMnGa FSMA single crystals is verified by comparing the predictions with corresponding experimental results. It is shown that the proposed model can quantitatively capture the main experimental phenomena. Further, the proposed model is used to predict the deformations of the single crystals under the non-proportional mechanical loading conditions.展开更多
The traditional "brain-derived neurotrophic factor(BDNF) hypothesis of depression" proposes that impairment of the BDNF signaling pathway in the hippocampus and prefrontal cortex participates in the pathophy...The traditional "brain-derived neurotrophic factor(BDNF) hypothesis of depression" proposes that impairment of the BDNF signaling pathway in the hippocampus and prefrontal cortex participates in the pathophysiology of depression,and antidepressants act by recovering/enhancing BDNF signal transduction.Recent studies have suggested that BDNF signaling pathways exert more diverse and complex effects on depression onset and antidepressant therapy than originally thought,which include:(1) inhibition of the BDNF-TrkB signaling pathway in the hippocampus and/or prefrontal cortex does not induce the depression-like behavioral phenotype,but significantly diminishes therapeutic effects,which suggests that the BDNF-TrkB signaling pathway lacks direct or key effects on occurrence of emotional disorders,whereas an intact and normal BDNF-TrkB signaling pathway is necessary for antidepressant therapy.(2) The BDNF-TrkB signaling pathway exhibits opposite regulatory effects on depressive behavior in the hippocampus-prefrontal cortex network and mesolimbic system,which suggests that BDNF regulates emotion by affecting the emotion-related neural network,but not a single brain region.(3) The BDNF-TrkB and proBDNF-p75NTR signaling pathways in the brain,respectively,enhance and suppress hippocampal neural plasticity,which demonstrated that different BDNF signaling pathways interact and restrict each other in the regulation of neural plasticity and emotional behaviors.(4) BDNF gene polymorphism might be associated with susceptibility to depression.These new findings extend our understanding of neuronal pathways and mechanisms of action of BDNF signaling and contribute to improved views to traditional "neurotrophic factor hypothesis of depression".展开更多
Developing techniques to effectively and real-time monitor and regulate the interior environment of biological objects is significantly important for many biomedical engineering and scientific applications, including ...Developing techniques to effectively and real-time monitor and regulate the interior environment of biological objects is significantly important for many biomedical engineering and scientific applications, including drug delivery, electrophysiological recording and regulation of intracellular activities. Semi-implantable bioelectronics is currently a hot spot in biomedical engineering research area, because it not only meets the increasing technical demands for precise detection or regulation of biological activities, but also provides a desirable platform for externally incorporating complex functionalities and electronic integration. Although there is less definition and summary to distinguish it from the well-reviewed non-invasive bioelectronics and fully implantable bioelectronics, semi-implantable bioelectronics have emerged as highly unique technology to boost the development of biochips and smart wearable device. Here, we reviewed the recent progress in this field and raised the concept of “Semi-implantable bioelectronics”, summarizing the principle and strategies of semi-implantable device for cell applications and in vivo applications, discussing the typical methodologies to access to intracellular environment or in vivo environment, biosafety aspects and typical applications. This review is meaningful for understanding in-depth the design principles, materials fabrication techniques, device integration processes, cell/tissue penetration methodologies, biosafety aspects, and applications strategies that are essential to the development of future minimally invasive bioelectronics.展开更多
Introduction Despite the numerous breakthroughs made in medical and biomedical technologies,biosensing underneath the skin without any associated pain still sounds like a dream yet to be realized.Minimally invasive bi...Introduction Despite the numerous breakthroughs made in medical and biomedical technologies,biosensing underneath the skin without any associated pain still sounds like a dream yet to be realized.Minimally invasive biosensors refer to functional or electronic sensors that can contact the interior environment of living organisms and their biological tissues,while the connected bulk devices remain on the surface of the biological objects[1].Minimally invasive biosensors are currently a key research area because they can not only meet the increasing technical demands to precisely detect biological activities inside biological objects,but also provide an ideal platform to externally incorporate complicated functionalities and electronic integration[2].The current development level of minimally invasive sensing still necessitates solving the constraints and bottlenecks in the three aspects of functionalities,sensitivity and biocompatibility[3].In this perspective,we select minimally invasive sensors as a representative research object with the aim to solve the limitations of current diabetes diagnosis and treatment approaches.展开更多
Establishing a reliable electrophysiological recording platform is crucial for cardiology and neuroscience research.Noninvasive and label-free planar multitransistors and multielectrode arrays are conducive to perform...Establishing a reliable electrophysiological recording platform is crucial for cardiology and neuroscience research.Noninvasive and label-free planar multitransistors and multielectrode arrays are conducive to perform the large-scale cellular electrical activity recordings,but the signal attenua-tion limits these extracellular devices to record subthreshold activities.In recent decade,in-cell nanoelectronics have been rapidly developed to open the door to intracellular electrophysi-ology.With the unique three-dimensional nanotopography and advanced penetration strategies,high-throughput and high-fidelity action potential like signal recordings is expected to be realized.This review summarizes in-cell nanoelectronics from versatile nano-biointerfaces,penetration strategies,active/pas-sive nanodevices,systematically analyses the applications in electrogenic cells and especially evaluates the influence of nanodevices on the high-quality intracellular electrophysiological signals.Further,the opportunities,challenges and broad prospects of in-cell nanoelectronics are prospected,expecting to promote the development of in-cell electrophysiological platforms to meet the demand of theoretical investigation and clinical application.展开更多
Facing the contradiction of water scarcity and water wastage in most cities of China, this study aims at probing into the factors influencing water-use efficiency and assessing water-saving potential by adopting press...Facing the contradiction of water scarcity and water wastage in most cities of China, this study aims at probing into the factors influencing water-use efficiency and assessing water-saving potential by adopting pressure control measures based on field survey conducted in 23 high-rise buildings in Suqian, China and laboratory tests. Results showed that per capita water consumption (PCWC) exceeding water consumption norms is common in these buildings. The hourly water consumption variation law is quite different among different types of buildings. These differences should be considered in designing building water supply systems to lower water and energy consumption. On the basis of correlation analysis, the order of factors influencing the PCWC follows average tap water pressure, percapita building area, and building age, suggesting pressure management in high-rise buildings is a key water-saving measure. Field tests of outflow characteristics under different water pressures indicated that over-pressure outflow (OPO) is a common cause of water wastage in buildings, however, no branch pipe pressure control measures were found in all the surveyed buildings. Laboratory tests showed that branch pipe pressure-reducing measures can lower water consumption and improve the comfortability of use as well. Therefore, in addition to applying high efficiency water-saving devices, we strongly recommend that branch pipe pressure-reducing measures should be strictly implemented in designing new building water supply systems and reconstruction of existing old building water supply systems, thereby, promoting water, energy saving and development of green building.展开更多
Electrical contact materials are generally Ag-or Cu-based composites and play a critical role in ensuring the reliability and efficiency of electrical equipments and electronic instruments.The MAX(M is an early transi...Electrical contact materials are generally Ag-or Cu-based composites and play a critical role in ensuring the reliability and efficiency of electrical equipments and electronic instruments.The MAX(M is an early transition metal,A is an element from III or IV main groups,and X is carbon or/and nitrogen)phase ceramics display a unique combination of properties and may serve as an ideal reinforcement phase for electrical contact materials.The biological materials evolved in nature generally exhibit three-dimensional(3D)interpenetrating-phase architectures,which may offer useful inspiration for the architectural design of electrical contact materials.Here,a series of bi-continuous Ag-Ti_(3)SiC_(2) MAX phase composites with high ceramic contents exceeding 50 vol.%and having micron-and ultrafine-scaled 3D interpenetrating-phase architectures,wherein both constituents were continuous and mutually interspersed,were exploited by pressureless infiltration of Ag melt into partially sintered Ti_(3)SiC_(2) scaffolds.The mechanical and electrical properties as well as the friction and wear performance of the composites were investigated and revealed to be closely dependent on the ceramic contents and characteristic structural dimensions.The composites exhibited a good combination of properties with high hardness over 2.3 GPa,high flexural strength exceeding 530 MPa,decent fracture toughness over 10 MPa·m^(1/2),and good wear resistance with low wear rate at an order of 10^(-5)mm^(3)/(N·m),which were much superior compared to the counterparts made by powder metallurgy methods.In particular,the hardness,electrical conductivity,strength,and fracture toughness of the composites demonstrated a simultaneous improvement as the structure was refined from micron-to ultrafine-scales at equivalent ceramic contents.The good combination of properties along with the facile processing route makes the Ag-Ti_(3)SiC_(2)3D interpenetrating-phase composites appealing for electrical contact applications.展开更多
Psoriatic arthritis(PsA) is a rheumatoid factor(RF)-seronegative systemic inflammatory disorder associated with psoriasis.Current treatment for PsA in China is still focused on disease modifying anti-rheumatic drugs(D...Psoriatic arthritis(PsA) is a rheumatoid factor(RF)-seronegative systemic inflammatory disorder associated with psoriasis.Current treatment for PsA in China is still focused on disease modifying anti-rheumatic drugs(DMARDs).In this paper,we report two Chinese patients with active longstanding PsA treated with infliximab,a human-mouse chimeric monoclonal antibody against tumor necrosis factor alpha(TNF-α).The results show that infliximab acted quickly and effectively in relieving peripheral and axial symptoms and refractory skin lesions,even in recombinant human TNF-α receptor(rhTNFR)-resistant case.The take-home message from our cases is that infliximab is a useful therapeutic option for refractory PsA,especially when a patient has a combination of psoriasis and psoriatic arthritis.Further local evidence and experience must be accumulated in order to make anti-TNF-α therapy more accessible to PsA patients in China.展开更多
The cyclic transformation behaviors of polycrystalline super-elastic NiTi shape memory alloys (SMAs)under multiaxial loading paths with different angles between axial and torsional loading orientations were experiment...The cyclic transformation behaviors of polycrystalline super-elastic NiTi shape memory alloys (SMAs)under multiaxial loading paths with different angles between axial and torsional loading orientations were experimentally investigated.The experimental results showed that the start stresses of forward and reverse transformations decreased with the increase'in the number of cycles and exhibit obvious anisotropic evolutions.The start stresses of forward and reverse transformations in the tensile and torsional directions did not satisfy the yon Mises criterion.The shape of transformation surface during the forward and reverse transformations evolved with the increase in the number of cycles.Then,new cyclic anisotropic transformation surfaces were established by introducing an anisotropic tensor into the von Mises equivalent stress based on a typical transformation criterion related to J2 and J3.Moreover,the evolution equations of material parameters used in the proposed transformation surfaces were established to describe the subsequent evolutions of transformation surfaces.Finally,the start stresses of forward and reverse transformations predicted using the proposed transformation surfaces were compared with the experimental results.It shows that the proposed transformation surfaces can reasonably describe the start stresses of forward and reverse transformations,which are helpful for establishing a three-dimensional cyclic constitutive model to describe the cyclic transformation behaviors of super-elastic NiTi SMAs.展开更多
Monitoring human health is of considerable significance in biomedicine.In particular,the ion concentrations in blood are important reference indicators related to many diseases.Microneedle array-based sensors have ena...Monitoring human health is of considerable significance in biomedicine.In particular,the ion concentrations in blood are important reference indicators related to many diseases.Microneedle array-based sensors have enabled promising breakthroughs in continuous health monitoring due to their minimally invasive nature.In this study,we developed a microneedle sensing-array integrated system to continuously detect subcutaneous ions to monitor human health status in real time based on a fabrication strategy for assembling planar microneedle sheets to form 3D microneedle arrays.The limitations of preparing 3D microneedle structures with multiple electrode channels were addressed by assembling planar microneedle sheets fabricated via laser micromachining;the challenges of modifying closely spaced microneedle tips into different functionalized types of electrodes were avoided.The microneedle sensing system was sufficiently sensitive for detecting real-time changes in Ca^(2+),K^(+),and Na^(+) concentrations,and it exhibited good detection performance.The in vivo results showed that the ion-sensing microneedle array successfully monitored the fluctuations in Ca^(2+),k^(+),and Na^(+) in the interstitial fluids of rats in real time.By using an integrated circuit design,we constructed the proposed microneedle sensor into a wearable integrated monitoring system.The integrated system could potentially provide information feedback for diseases related to physiological ion changes.展开更多
Crisp Nile tilapia(Oreochromis niloticus)is a kind of valuable fish product with high muscle firmness and crispiness texture.However,with the change of physicochemical in crisp Nile tilapia,the frozen storage paramete...Crisp Nile tilapia(Oreochromis niloticus)is a kind of valuable fish product with high muscle firmness and crispiness texture.However,with the change of physicochemical in crisp Nile tilapia,the frozen storage parameters and quality would be different comparing to normal Nile tilapia.Thus,the aim of this study was to analyze the changes in texture,chemical quality indices and volatile compounds of Nile tilapia fillets during frozen storage.The remaining storage time of the crisp Nile tilapia fillets could be estimated within 120 days.During frozen storage,fillets resulted in softer started at 90-day,and 36.75%,45.74%,48.81%and 20.37%reduction of hardness,springiness,gumminess and chewiness were observed at 120-day.Thiobarbituric acid reactive substances(TBARS)for frozen samples showed similar with fresh fillets within 60 days,while the TBARS was 1.97 folds higher than fresh one at 120-day.Low-field nuclear magnetic resonance(LF-NMR)indicated that the water loss of Nile tilapia fillets was significant changed at 120-day,which reduced more than 12.5%water out of weight.The volatile compound analysis showed that more free fatty acid will be detected at 120-day comparing to the fresh fillets.The combined results demonstrated that the crisp Nile tilapia fillets had the best quality before 60 days frozen storage then loss of some quality properties in longer freezing.Thus,these results identified the ideal storage strategy for the preservation of crisp Nile tilapia without affecting sensory appeal and commercial value.展开更多
COVID-19 has seriously threatened public health,and transdermal vaccination is an effective way to prevent pathogen infection.Microneedles(MNs)can damage the stratum corneum to allow passive diffusion of vaccine macro...COVID-19 has seriously threatened public health,and transdermal vaccination is an effective way to prevent pathogen infection.Microneedles(MNs)can damage the stratum corneum to allow passive diffusion of vaccine macromolecules,but the delivery effciency is low,while iontophoresis can actively promote transdermal delivery but fails to transport vaccine macromolecules due to the barrier of the stratum corneum.Herein,we developed a wearable iontophoresis-driven MN patch and its iontophoresis-driven device for active and effcient transdermal vaccine macromolecule delivery.Polyacrylamide/chitosan hydrogels with good biocompatibility,excellent conductivity,high elasticity,and a large loading capacity were prepared as the key component for vaccine storage and active iontophoresis.The transdermal vaccine delivery strategy of the iontophoresis-driven MN patch is“press and poke,iontophoresis-driven delivery,and immune response”.We demonstrated that the synergistic effect of MN puncture and iontophoresis significantly promoted transdermal vaccine delivery effciency.In vitro experiments showed that the amount of ovalbumin delivered transdermally using the iontophoresis-driven MN patch could be controlled by the iontophoresis current.In vivo immunization studies in BALB/c mice demonstrated that transdermal inoculation of ovalbumin using an iontophoresis-driven MN patch induced an effective immune response that was even stronger than that of traditional intramuscular injection.Moreover,there was little concern about the biosafety of the iontophoresis-driven MN patch.This delivery system has a low cost,is user-friendly,and displays active delivery,showing great potential for vaccine self-administration at home.展开更多
To date,development of high-performance,stretchable gas sensors operating at and below room temperature(RT)remains a challenge in terms of traditional sensing materials.Herein,we report on a high-performance NO_(2) ga...To date,development of high-performance,stretchable gas sensors operating at and below room temperature(RT)remains a challenge in terms of traditional sensing materials.Herein,we report on a high-performance NO_(2) gas sensor based on a self-healable,recyclable,ultrastretchable,and stable polyvinyl alcohol–cellulose nanofibril double-network organohydrogel,which features ultrahigh sensitivity(372%/ppm),low limit of detection(2.23 ppb),relatively fast response and recovery time(41/144 s for 250 ppb NO_(2)),good selectivity against interfering gases(NH3,CO_(2),ethanol,and acetone),excellent reversibility,repeatability,and long-term stability at RT or even at−20°C.In particular,this sensor shows outstanding stability against large deformations and mechanical damages so that it works normally after rapid self-healing or remolding after undergoing mechanical damage without significant performance degradation,which has major advantages compared to state-of-the-art gas sensors.The high NO_(2) sensitivity and selectivity are attributed to the selective redox reactions at the threephase interface of gas,gel,and electrode,which is even boosted by applying tensile strain.With a specific electrical circuit design,a wireless NO_(2) alarm system based on this sensor is created to enable continuous,real-time,and wireless NO_(2) detection to avoid the risk of exposure to NO_(2) higher than threshold concentrations.展开更多
Textured Ti2AlC lamellar composites have been successfully fabricated by a new method in the present work.The composites exhibit high compressive strength of ca 2 GPa,fracture toughness of 8.5 MPa m1/2(//c-axis),flexu...Textured Ti2AlC lamellar composites have been successfully fabricated by a new method in the present work.The composites exhibit high compressive strength of ca 2 GPa,fracture toughness of 8.5 MPa m1/2(//c-axis),flexural strength of 735 MPa(//c-axis)and high hardness of 7.9 GPa(//c-axis).The strengthening mechanisms were discussed.The sintering and densification process was investigated and crystal orientation and microstructure were studied by electron backscattered diffraction techniques.The synthesis temperature is reduced to 1200?C by using high surface-to-volume ratio Ti2AlC nano flakes.The Lotgering orientation factor of Ti2 AlC and Ti3 AlC2{00 l}planes in the textured top surface reaches 0.74 and 0.49,respectively.This new route may shed light on resolving the difficulties encountered in large scale fabrication of textured MAX phases.展开更多
Our previous study demonstrated that phosphodiesterase 8(PDE8)could work as a potential target for vascular dementia(Va D)using a chemical probe 3a.However,compound 3a is a chiral compound which was obtained by chiral...Our previous study demonstrated that phosphodiesterase 8(PDE8)could work as a potential target for vascular dementia(Va D)using a chemical probe 3a.However,compound 3a is a chiral compound which was obtained by chiral resolution on HPLC,restricting its usage in clinic.Herein,a series of non-chiral 9-benzyl-2-chloro-adenine derivatives were discovered as novel PDE8 inhibitors.Lead 15 exhibited potent inhibitory activity against PDE8A(IC_(50)=11 nmol/L),high selectivity over other PDEs,and remarkable drug-like properties(worthy to mention is that its bioavailability was up to 100%).Oral administration of 15 significantly improved the c AMP level of the right brain and exhibited dosedependent effects on cognitive improvement in a Va D mouse model.Notably,the X-ray crystal structure of the PDE8A—15 complex showed that the potent affinity and high selectivity of 15 might come from the distinctive interactions with H-pocket including T-shapedπ—πinteractions with Phe785 as well as a unique H-bond network,which have never been observed in other PDE-inhibitor complex before,providing new strategies for the further rational design of novel selective inhibitors against PDE8.展开更多
Optical surface waves have widely been used in optical tweezers systems for trapping particles sized from the nanoto microscale,with specific importance and needs in applications of super-resolved detection and imagin...Optical surface waves have widely been used in optical tweezers systems for trapping particles sized from the nanoto microscale,with specific importance and needs in applications of super-resolved detection and imaging if a single particle can be trapped and manipulated accurately.However,it is difficult to achieve such trapping with high precision in conventional optical surface-wave tweezers.Here,we propose and experimentally demonstrate a new method to accurately trap and dynamically manipulate a single particle or a desired number of particles in holographic optical surface-wave tweezers.By tailoring the optical potential wells formed by surface waves,we achieved trapping of the targeted single particle while pushing away all surrounding particles and further dynamically controlling the particle by a holographic tweezers beam.We also prove that different particle samples,including gold particles and biological cells,can be applied in our system.This method can be used for different-type optical surface-wave tweezers,with significant potential applications in single-particle spectroscopy,particle sorting,nano-assembly,and others.展开更多
基金This work was financially supported by the National Key R&D Program of China(Nos.2021YFF1200700 and 2021YFA0911100)the National Natural Science Foundation of China(Nos.32171399,32171456,and T2225010)+6 种基金the Guangdong Basic and Applied Basic Research Foundation(No.2021A1515012261)the Science and Technology Program of Guangzhou,China(No.202103000076)the Fundamental Research Funds for the Central Universities,Sun Yat-Sen University(No.22dfx02),and Pazhou Lab,Guangzhou(No.PZL2021KF0003)FML would like to thank the National Natural Science Foundation of China(Nos.32171335 and 31900954)JL would like to thank the National Natural Science Foundation of China(No.62105380)the China Postdoctoral Science Foundation(No.2021M693686)QQOY would like to thank the China Postdoctoral Science Foundation(No.2022M713645).
文摘Conventional blood sampling for glucose detection is prone to cause pain and fails to continuously record glucose fluctuations in vivo.Continuous glucose monitoring based on implantable electrodes could induce pain and potential tissue inflammation,and the presence of reactive oxygen species(ROS)due to inflammationmay affect glucose detection.Microneedle technology is less invasive,yet microneedle adhesion with skin tissue is limited.In this work,we developed a microarrow sensor array(MASA),which provided enhanced skin surface adhesion and enabled simultaneous detection of glucose and H_(2)O_(2)(representative of ROS)in interstitial fluid in vivo.The microarrows fabricated via laser micromachining were modified with functional coating and integrated into a patch of a three-dimensional(3D)microneedle array.Due to the arrow tip mechanically interlocking with the tissue,the microarrow array could better adhere to the skin surface after penetration into skin.The MASA was demonstrated to provide continuous in vivo monitoring of glucose and H_(2)O_(2) concentrations,with the detection of H_(2)O_(2) providing a valuable reference for assessing the inflammation state.Finally,the MASA was integrated into a monitoring system using custom circuitry.This work provides a promising tool for the stable and reliable monitoring of blood glucose in diabetic patients.
基金The authors would like to acknowledge financial support from the National Key R&D Program of China(Nos.2021YFF1200700 and 2021YFA0911100)the National Natural Science Foundation of China(Nos.T2225010,32171399,and 32171456)+4 种基金the Fundamental Research Funds for the Central Universities,Sun Yat-Sen University(No.22dfx02)Pazhou Lab,Guangzhou(No.PZL2021KF0003)The authors also would like to thank the funding support from the Opening Project of Key Laboratory of Microelectronic Devices&Integrated Technology,Institute of Microelectronics,Chinese Academy of Sciences,and State Key Laboratory of Precision Measuring Technology and Instruments(No.pilab2211)QQOY would like to thank the China Postdoctoral Science Foundation(No.2022M713645)JL would like to thank the National Natural Science Foundation of China(No.62105380)and the China Postdoctoral Science Foundation(No.2021M693686).
文摘Modern medicine is increasingly interested in advanced sensors to detect and analyze biochemical indicators.Ion sensors based on potentiometric methods are a promising platform for monitoring physiological ions in biological subjects.Current semi-implantable devices are mainly based on single-parameter detection.Miniaturized semi-implantable electrodes for multiparameter sensing have more restrictions on the electrode size due to biocompatibility considerations,but reducing the electrode surface area could potentially limit electrode sensitivity.This study developed a semi-implantable device system comprising a multiplexed microfilament electrode cluster(MMEC)and a printed circuit board for real-time monitoring of intra-tissue K^(+),Ca^(2+),and Na^(+)concentrations.The electrode surface area was less important for the potentiometric sensing mechanism,suggesting the feasibility of using a tiny fiber-like electrode for potentiometric sensing.The MMEC device exhibited a broad linear response(K^(+):2–32 mmol/L;Ca^(2+):0.5–4 mmol/L;Na^(+):10–160 mmol/L),high sensitivity(about 20–45 mV/decade),temporal stability(>2weeks),and good selectivity(>80%)for the above ions.In vitro detection and in vivo subcutaneous and brain experiment results showed that the MMEC system exhibits good multi-ion monitoring performance in several complex environments.This work provides a platform for the continuous real-time monitoring of ion fluctuations in different situations and has implications for developing smart sensors to monitor human health.
基金support from the National Natural Science Foundation of China(61801525)the Guangdong Basic and Applied Basic Research Foundation(2020A1515010693)+1 种基金the Guangdong Natural Science Funds Grant(2018A030313400),the Science and Technology Program of Guangzhou(201904010456)the Fundamental Research Funds for the Central Universities,Sun Yat-sen University(2021qntd09).
文摘With the advent of the 5G era and the rise of the Internet of Things,various sensors have received unprecedented attention,especially wearable and stretchable sensors in the healthcare field.Here,a stretchable,self-healable,self-adhesive,and room-temperature oxygen sensor with excellent repeatability,a full concentration detection range(0-100%),low theoretical limit of detection(5.7 ppm),high sensitivity(0.2%/ppm),good linearity,excellent temperature,and humidity tolerances is fabricated by using polyacrylamide-chitosan(PAM-CS)double network(DN)organohydrogel as a novel transducing material.The PAM-CS DN organohydrogel is transformed from the PAM-CS composite hydrogel using a facile soaking and solvent replacement strategy.Compared with the pristine hydrogel,the DN organohydrogel displays greatly enhanced mechanical strength,moisture retention,freezing resistance,and sensitivity to oxygen.Notably,applying the tensile strain improves both the sensitivity and response speed of the organohydrogel-based oxygen sensor.Furthermore,the response to the same concentration of oxygen before and after self-healing is basically the same.Importantly,we propose an electrochemical reaction mechanism to explain the positive current shift of the oxygen sensor and corroborate this sensing mechanism through rationally designed experiments.The organohydrogel oxygen sensor is used to monitor human respiration in real-time,verifying the feasibility of its practical application.This work provides ideas for fabricating more stretchable,self-healable,self-adhesive,and high-performance gas sensors using ion-conducting organohydrogels.
基金the National Natural Science Foundation of China (Grant 11602203)Young Elite Scientist Sponsorship Program by the China Association for Science and Technology (Grant 2016QNRC001)Fundamental Research Funds for the Central Universities (Grant 2682018CX43).
文摘Existing experimental results have shown that four types of physical mechanisms, namely, martensite transformation, martensite reorientation, magnetic domain wall motion and magnetization vector rotation, can be activated during the magneto-mechanical deformation of NiMnGa ferromagnetic shape memory alloy (FSMA) single crystals. In this work, based on irreversible thermodynamics, a three-dimensional (3D) single crystal constitutive model is constructed by considering the aforementioned four mechanisms simultaneously. Three types of internal variables, i.e., the volume fraction of each martensite variant, the volume fraction of magnetic domain in each variant and the deviation angle between the magnetization vector, and easy axis are introduced to characterize the magneto-mechanical state of the single crystals. The thermodynamic driving force of each mechanism and the thermodynamic constraints on the constitutive model are obtained from Clausius's dissipative inequality and constructed Gibbs free energy. Then, thermodynamically consistent kinetic equations for the four mechanisms are proposed, respectively. Finally, the ability of the proposed model to describe the magneto-mechanical deformation of NiMnGa FSMA single crystals is verified by comparing the predictions with corresponding experimental results. It is shown that the proposed model can quantitatively capture the main experimental phenomena. Further, the proposed model is used to predict the deformations of the single crystals under the non-proportional mechanical loading conditions.
基金the National Natural Science Foundation of China,No. 30500158,30670708the Major Direc-tion Program of Chinese Academy of Sciences,No. KSCX2-YW-R-131+1 种基金the National Basic Research Project (973 Program) of China,No. 2007CB512306the Development Foundation of Institute of Psychology,Chinese Academy of Sci-ences,No. O9KF013001
文摘The traditional "brain-derived neurotrophic factor(BDNF) hypothesis of depression" proposes that impairment of the BDNF signaling pathway in the hippocampus and prefrontal cortex participates in the pathophysiology of depression,and antidepressants act by recovering/enhancing BDNF signal transduction.Recent studies have suggested that BDNF signaling pathways exert more diverse and complex effects on depression onset and antidepressant therapy than originally thought,which include:(1) inhibition of the BDNF-TrkB signaling pathway in the hippocampus and/or prefrontal cortex does not induce the depression-like behavioral phenotype,but significantly diminishes therapeutic effects,which suggests that the BDNF-TrkB signaling pathway lacks direct or key effects on occurrence of emotional disorders,whereas an intact and normal BDNF-TrkB signaling pathway is necessary for antidepressant therapy.(2) The BDNF-TrkB signaling pathway exhibits opposite regulatory effects on depressive behavior in the hippocampus-prefrontal cortex network and mesolimbic system,which suggests that BDNF regulates emotion by affecting the emotion-related neural network,but not a single brain region.(3) The BDNF-TrkB and proBDNF-p75NTR signaling pathways in the brain,respectively,enhance and suppress hippocampal neural plasticity,which demonstrated that different BDNF signaling pathways interact and restrict each other in the regulation of neural plasticity and emotional behaviors.(4) BDNF gene polymorphism might be associated with susceptibility to depression.These new findings extend our understanding of neuronal pathways and mechanisms of action of BDNF signaling and contribute to improved views to traditional "neurotrophic factor hypothesis of depression".
基金financial support from the National Natural Science Foundation of China(Grant Nos.32171399)the National Key R&D Program of China(Grant Nos.2021YFF1200700,2021YFA0911100)+1 种基金the National Natural Science Foundation of China(Grant Nos.32171456,32171335,61901535,31900954,62104264)。
文摘Developing techniques to effectively and real-time monitor and regulate the interior environment of biological objects is significantly important for many biomedical engineering and scientific applications, including drug delivery, electrophysiological recording and regulation of intracellular activities. Semi-implantable bioelectronics is currently a hot spot in biomedical engineering research area, because it not only meets the increasing technical demands for precise detection or regulation of biological activities, but also provides a desirable platform for externally incorporating complex functionalities and electronic integration. Although there is less definition and summary to distinguish it from the well-reviewed non-invasive bioelectronics and fully implantable bioelectronics, semi-implantable bioelectronics have emerged as highly unique technology to boost the development of biochips and smart wearable device. Here, we reviewed the recent progress in this field and raised the concept of “Semi-implantable bioelectronics”, summarizing the principle and strategies of semi-implantable device for cell applications and in vivo applications, discussing the typical methodologies to access to intracellular environment or in vivo environment, biosafety aspects and typical applications. This review is meaningful for understanding in-depth the design principles, materials fabrication techniques, device integration processes, cell/tissue penetration methodologies, biosafety aspects, and applications strategies that are essential to the development of future minimally invasive bioelectronics.
基金the National Natural Science Foundation of China(Nos.61771498,61901535 and 81970778)Science and Technology Planning Project of Guangdong Province for Industrial Applications(No.2017B090917001)+3 种基金Guangdong Province Key Area R&D Program(No.2018B030332001)Science and Technology Program of GuangzhouChina(No.202102080192)Guangdong Basic and Applied Basic Research Foundation(Nos.2021A1515012261,2019A1515012087,2020A1515010987 and 2020A1515110424)and Key Program of Sun Yat-Sen University(No.20lgzd14).
文摘Introduction Despite the numerous breakthroughs made in medical and biomedical technologies,biosensing underneath the skin without any associated pain still sounds like a dream yet to be realized.Minimally invasive biosensors refer to functional or electronic sensors that can contact the interior environment of living organisms and their biological tissues,while the connected bulk devices remain on the surface of the biological objects[1].Minimally invasive biosensors are currently a key research area because they can not only meet the increasing technical demands to precisely detect biological activities inside biological objects,but also provide an ideal platform to externally incorporate complicated functionalities and electronic integration[2].The current development level of minimally invasive sensing still necessitates solving the constraints and bottlenecks in the three aspects of functionalities,sensitivity and biocompatibility[3].In this perspective,we select minimally invasive sensors as a representative research object with the aim to solve the limitations of current diabetes diagnosis and treatment approaches.
基金The work is supported in part by the National Natural Science Foundation of China(Grant Nos.82061148011,61771498)Guangdong Basic and Applied Basic Research Foundation(Grant No.2020A1515010665)+2 种基金Department of Science and Technology of Guangdong Province Project(Grant No.2020B1212060030)Foundation of Sun Yat-sen University(Grant Nos.76120-18821104,20lgpy47,20lgzd14)Open Project of Chinese Academy of Sciences(Grant No.SKT2006).
文摘Establishing a reliable electrophysiological recording platform is crucial for cardiology and neuroscience research.Noninvasive and label-free planar multitransistors and multielectrode arrays are conducive to perform the large-scale cellular electrical activity recordings,but the signal attenua-tion limits these extracellular devices to record subthreshold activities.In recent decade,in-cell nanoelectronics have been rapidly developed to open the door to intracellular electrophysi-ology.With the unique three-dimensional nanotopography and advanced penetration strategies,high-throughput and high-fidelity action potential like signal recordings is expected to be realized.This review summarizes in-cell nanoelectronics from versatile nano-biointerfaces,penetration strategies,active/pas-sive nanodevices,systematically analyses the applications in electrogenic cells and especially evaluates the influence of nanodevices on the high-quality intracellular electrophysiological signals.Further,the opportunities,challenges and broad prospects of in-cell nanoelectronics are prospected,expecting to promote the development of in-cell electrophysiological platforms to meet the demand of theoretical investigation and clinical application.
文摘Facing the contradiction of water scarcity and water wastage in most cities of China, this study aims at probing into the factors influencing water-use efficiency and assessing water-saving potential by adopting pressure control measures based on field survey conducted in 23 high-rise buildings in Suqian, China and laboratory tests. Results showed that per capita water consumption (PCWC) exceeding water consumption norms is common in these buildings. The hourly water consumption variation law is quite different among different types of buildings. These differences should be considered in designing building water supply systems to lower water and energy consumption. On the basis of correlation analysis, the order of factors influencing the PCWC follows average tap water pressure, percapita building area, and building age, suggesting pressure management in high-rise buildings is a key water-saving measure. Field tests of outflow characteristics under different water pressures indicated that over-pressure outflow (OPO) is a common cause of water wastage in buildings, however, no branch pipe pressure control measures were found in all the surveyed buildings. Laboratory tests showed that branch pipe pressure-reducing measures can lower water consumption and improve the comfortability of use as well. Therefore, in addition to applying high efficiency water-saving devices, we strongly recommend that branch pipe pressure-reducing measures should be strictly implemented in designing new building water supply systems and reconstruction of existing old building water supply systems, thereby, promoting water, energy saving and development of green building.
基金supports from the National Key R&D Program of China(No.2020YFA0710404)the National Natural Science Foundation of China(No.52173269),the KC Wong Education Foundation(No.GJTD-2020-09)the Liaoning Revitalization Talents Program,and the Youth Innovation Promotion Association CAS(No.2019191).
文摘Electrical contact materials are generally Ag-or Cu-based composites and play a critical role in ensuring the reliability and efficiency of electrical equipments and electronic instruments.The MAX(M is an early transition metal,A is an element from III or IV main groups,and X is carbon or/and nitrogen)phase ceramics display a unique combination of properties and may serve as an ideal reinforcement phase for electrical contact materials.The biological materials evolved in nature generally exhibit three-dimensional(3D)interpenetrating-phase architectures,which may offer useful inspiration for the architectural design of electrical contact materials.Here,a series of bi-continuous Ag-Ti_(3)SiC_(2) MAX phase composites with high ceramic contents exceeding 50 vol.%and having micron-and ultrafine-scaled 3D interpenetrating-phase architectures,wherein both constituents were continuous and mutually interspersed,were exploited by pressureless infiltration of Ag melt into partially sintered Ti_(3)SiC_(2) scaffolds.The mechanical and electrical properties as well as the friction and wear performance of the composites were investigated and revealed to be closely dependent on the ceramic contents and characteristic structural dimensions.The composites exhibited a good combination of properties with high hardness over 2.3 GPa,high flexural strength exceeding 530 MPa,decent fracture toughness over 10 MPa·m^(1/2),and good wear resistance with low wear rate at an order of 10^(-5)mm^(3)/(N·m),which were much superior compared to the counterparts made by powder metallurgy methods.In particular,the hardness,electrical conductivity,strength,and fracture toughness of the composites demonstrated a simultaneous improvement as the structure was refined from micron-to ultrafine-scales at equivalent ceramic contents.The good combination of properties along with the facile processing route makes the Ag-Ti_(3)SiC_(2)3D interpenetrating-phase composites appealing for electrical contact applications.
文摘Psoriatic arthritis(PsA) is a rheumatoid factor(RF)-seronegative systemic inflammatory disorder associated with psoriasis.Current treatment for PsA in China is still focused on disease modifying anti-rheumatic drugs(DMARDs).In this paper,we report two Chinese patients with active longstanding PsA treated with infliximab,a human-mouse chimeric monoclonal antibody against tumor necrosis factor alpha(TNF-α).The results show that infliximab acted quickly and effectively in relieving peripheral and axial symptoms and refractory skin lesions,even in recombinant human TNF-α receptor(rhTNFR)-resistant case.The take-home message from our cases is that infliximab is a useful therapeutic option for refractory PsA,especially when a patient has a combination of psoriasis and psoriatic arthritis.Further local evidence and experience must be accumulated in order to make anti-TNF-α therapy more accessible to PsA patients in China.
基金National Natural Science Foundation of China (1157226511532010),the Excellent Youth Found of Sichuan Province (2017JQ0019),the Open Project of Traction Power State Key Laboratory (TPL1606)and the Exploration Project of Traction Power State Key Laboratory (2017TPL_T04)are acknowledged.
文摘The cyclic transformation behaviors of polycrystalline super-elastic NiTi shape memory alloys (SMAs)under multiaxial loading paths with different angles between axial and torsional loading orientations were experimentally investigated.The experimental results showed that the start stresses of forward and reverse transformations decreased with the increase'in the number of cycles and exhibit obvious anisotropic evolutions.The start stresses of forward and reverse transformations in the tensile and torsional directions did not satisfy the yon Mises criterion.The shape of transformation surface during the forward and reverse transformations evolved with the increase in the number of cycles.Then,new cyclic anisotropic transformation surfaces were established by introducing an anisotropic tensor into the von Mises equivalent stress based on a typical transformation criterion related to J2 and J3.Moreover,the evolution equations of material parameters used in the proposed transformation surfaces were established to describe the subsequent evolutions of transformation surfaces.Finally,the start stresses of forward and reverse transformations predicted using the proposed transformation surfaces were compared with the experimental results.It shows that the proposed transformation surfaces can reasonably describe the start stresses of forward and reverse transformations,which are helpful for establishing a three-dimensional cyclic constitutive model to describe the cyclic transformation behaviors of super-elastic NiTi SMAs.
基金support from the National Key R&D Program of China(Grant No.2021YFF1200700,2021YFA0911100)National Natural Science Foundation of China(Grant No.32171399,32171456,T2225010)+6 种基金Guangdong Basic and Applied Basic Research Foundation(Grant No.2021A1515012261)Science and Technology Program of Guangzhou,China(Grant No.202103000076)Fundamental Research Funds for the Central Universities,Sun Yat-Sen University(Grant No.22dfx02)Pazhou Lab,Guangzhou(Grant No.PZL2021KF0003)Opening Project of Key Laboratory of Microelectronic Devices&Integrated Technology,Institute of Microelectronics,Chinese Academy of Sciences,Tianjin Key Laboratory of Imaging and Sensing Microelectronic Technology,Key Laboratory of The Diagnosis and Treatment of Severe Trauma and Burn of Zhejiang Province,Second Affliated Hospital of Zhejang University,School of Medicine(Grant.2022K02)State Key Laboratory Of Precision Measuring Technology And Instruments(Grant No.pilab2211)Open Funds of State Key Laboratory of Oncology in South China(Grant No.HN2022-01).
文摘Monitoring human health is of considerable significance in biomedicine.In particular,the ion concentrations in blood are important reference indicators related to many diseases.Microneedle array-based sensors have enabled promising breakthroughs in continuous health monitoring due to their minimally invasive nature.In this study,we developed a microneedle sensing-array integrated system to continuously detect subcutaneous ions to monitor human health status in real time based on a fabrication strategy for assembling planar microneedle sheets to form 3D microneedle arrays.The limitations of preparing 3D microneedle structures with multiple electrode channels were addressed by assembling planar microneedle sheets fabricated via laser micromachining;the challenges of modifying closely spaced microneedle tips into different functionalized types of electrodes were avoided.The microneedle sensing system was sufficiently sensitive for detecting real-time changes in Ca^(2+),K^(+),and Na^(+) concentrations,and it exhibited good detection performance.The in vivo results showed that the ion-sensing microneedle array successfully monitored the fluctuations in Ca^(2+),k^(+),and Na^(+) in the interstitial fluids of rats in real time.By using an integrated circuit design,we constructed the proposed microneedle sensor into a wearable integrated monitoring system.The integrated system could potentially provide information feedback for diseases related to physiological ion changes.
基金Key Research and Development Program of Guangzhou City(202103000067)Public science brand and standards establishment for Huadu Fishery Industrial Park(21302156)+1 种基金National Natural Science Foundation of China(42106130)Guangdong Basic and Applied Basic Research Foundation(2020A1515110237).
文摘Crisp Nile tilapia(Oreochromis niloticus)is a kind of valuable fish product with high muscle firmness and crispiness texture.However,with the change of physicochemical in crisp Nile tilapia,the frozen storage parameters and quality would be different comparing to normal Nile tilapia.Thus,the aim of this study was to analyze the changes in texture,chemical quality indices and volatile compounds of Nile tilapia fillets during frozen storage.The remaining storage time of the crisp Nile tilapia fillets could be estimated within 120 days.During frozen storage,fillets resulted in softer started at 90-day,and 36.75%,45.74%,48.81%and 20.37%reduction of hardness,springiness,gumminess and chewiness were observed at 120-day.Thiobarbituric acid reactive substances(TBARS)for frozen samples showed similar with fresh fillets within 60 days,while the TBARS was 1.97 folds higher than fresh one at 120-day.Low-field nuclear magnetic resonance(LF-NMR)indicated that the water loss of Nile tilapia fillets was significant changed at 120-day,which reduced more than 12.5%water out of weight.The volatile compound analysis showed that more free fatty acid will be detected at 120-day comparing to the fresh fillets.The combined results demonstrated that the crisp Nile tilapia fillets had the best quality before 60 days frozen storage then loss of some quality properties in longer freezing.Thus,these results identified the ideal storage strategy for the preservation of crisp Nile tilapia without affecting sensory appeal and commercial value.
基金supported by the National Natural Science Foundation of China(Project No.51975597 and 52175446)the Natural Science Foundation of Guangdong Province(Project Nos.2022B1515020011 and 2021A1515011740)+1 种基金the Shenzhen Science and Technology Program(Project No.JCYJ20220818102201003)the Foundation of Guangdong Provincial Key Laboratory of Sensor Technology and Biomedical Instrument(Project No.2020B1212060077).
文摘COVID-19 has seriously threatened public health,and transdermal vaccination is an effective way to prevent pathogen infection.Microneedles(MNs)can damage the stratum corneum to allow passive diffusion of vaccine macromolecules,but the delivery effciency is low,while iontophoresis can actively promote transdermal delivery but fails to transport vaccine macromolecules due to the barrier of the stratum corneum.Herein,we developed a wearable iontophoresis-driven MN patch and its iontophoresis-driven device for active and effcient transdermal vaccine macromolecule delivery.Polyacrylamide/chitosan hydrogels with good biocompatibility,excellent conductivity,high elasticity,and a large loading capacity were prepared as the key component for vaccine storage and active iontophoresis.The transdermal vaccine delivery strategy of the iontophoresis-driven MN patch is“press and poke,iontophoresis-driven delivery,and immune response”.We demonstrated that the synergistic effect of MN puncture and iontophoresis significantly promoted transdermal vaccine delivery effciency.In vitro experiments showed that the amount of ovalbumin delivered transdermally using the iontophoresis-driven MN patch could be controlled by the iontophoresis current.In vivo immunization studies in BALB/c mice demonstrated that transdermal inoculation of ovalbumin using an iontophoresis-driven MN patch induced an effective immune response that was even stronger than that of traditional intramuscular injection.Moreover,there was little concern about the biosafety of the iontophoresis-driven MN patch.This delivery system has a low cost,is user-friendly,and displays active delivery,showing great potential for vaccine self-administration at home.
基金Fundamental Research Funds for the Central Universities,Sun Yat-sen University,Grant/Award Number:22lgqb17National Natural Science Foundation of China,Grant/Award Number:61801525Guangdong Basic and Applied Basic Research Foundation,Grant/Award Number:2020A1515010693。
文摘To date,development of high-performance,stretchable gas sensors operating at and below room temperature(RT)remains a challenge in terms of traditional sensing materials.Herein,we report on a high-performance NO_(2) gas sensor based on a self-healable,recyclable,ultrastretchable,and stable polyvinyl alcohol–cellulose nanofibril double-network organohydrogel,which features ultrahigh sensitivity(372%/ppm),low limit of detection(2.23 ppb),relatively fast response and recovery time(41/144 s for 250 ppb NO_(2)),good selectivity against interfering gases(NH3,CO_(2),ethanol,and acetone),excellent reversibility,repeatability,and long-term stability at RT or even at−20°C.In particular,this sensor shows outstanding stability against large deformations and mechanical damages so that it works normally after rapid self-healing or remolding after undergoing mechanical damage without significant performance degradation,which has major advantages compared to state-of-the-art gas sensors.The high NO_(2) sensitivity and selectivity are attributed to the selective redox reactions at the threephase interface of gas,gel,and electrode,which is even boosted by applying tensile strain.With a specific electrical circuit design,a wireless NO_(2) alarm system based on this sensor is created to enable continuous,real-time,and wireless NO_(2) detection to avoid the risk of exposure to NO_(2) higher than threshold concentrations.
基金financially supported by the National Key R&D Program of China(Nos.2017YFB0306201 and 2016YFB0701303).
文摘Textured Ti2AlC lamellar composites have been successfully fabricated by a new method in the present work.The composites exhibit high compressive strength of ca 2 GPa,fracture toughness of 8.5 MPa m1/2(//c-axis),flexural strength of 735 MPa(//c-axis)and high hardness of 7.9 GPa(//c-axis).The strengthening mechanisms were discussed.The sintering and densification process was investigated and crystal orientation and microstructure were studied by electron backscattered diffraction techniques.The synthesis temperature is reduced to 1200?C by using high surface-to-volume ratio Ti2AlC nano flakes.The Lotgering orientation factor of Ti2 AlC and Ti3 AlC2{00 l}planes in the textured top surface reaches 0.74 and 0.49,respectively.This new route may shed light on resolving the difficulties encountered in large scale fabrication of textured MAX phases.
基金supported by the Natural Science Foundation of China(21877134,22077143,81903542,and 21977127)Science Foundation of Guangzhou City(201904020023,China)+3 种基金Fundamental Research Funds for Hainan University(KYQD(ZR)21031,China)Science Foundation of Guangdong Province(2019A1515011883,China)Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program(2017BT01Y093,China)Guangdong Province Higher Vocational Colleges&Schools Pearl River Scholar Funded Scheme(2016,China)。
文摘Our previous study demonstrated that phosphodiesterase 8(PDE8)could work as a potential target for vascular dementia(Va D)using a chemical probe 3a.However,compound 3a is a chiral compound which was obtained by chiral resolution on HPLC,restricting its usage in clinic.Herein,a series of non-chiral 9-benzyl-2-chloro-adenine derivatives were discovered as novel PDE8 inhibitors.Lead 15 exhibited potent inhibitory activity against PDE8A(IC_(50)=11 nmol/L),high selectivity over other PDEs,and remarkable drug-like properties(worthy to mention is that its bioavailability was up to 100%).Oral administration of 15 significantly improved the c AMP level of the right brain and exhibited dosedependent effects on cognitive improvement in a Va D mouse model.Notably,the X-ray crystal structure of the PDE8A—15 complex showed that the potent affinity and high selectivity of 15 might come from the distinctive interactions with H-pocket including T-shapedπ—πinteractions with Phe785 as well as a unique H-bond network,which have never been observed in other PDE-inhibitor complex before,providing new strategies for the further rational design of novel selective inhibitors against PDE8.
基金Guangdong Major Project of Basic and Applied Basic Research(2020B0301030009)National Natural Science Foundation of China(91750205,61935013,62175157,61975128,61975129)+3 种基金Leading Talents of Guangdong Province Program(00201505)Natural Science Foundation of Guangdong Province(2016A030312010,2019TQ05X750)Shenzhen Peacock Plan(KQTD20170330110444030)Science and Technology Innovation Commission of Shenzhen(JCYJ20180305125418079,JCYJ20180507182035270,JCYJ20210324120403011,ZDSYS201703031605029)。
文摘Optical surface waves have widely been used in optical tweezers systems for trapping particles sized from the nanoto microscale,with specific importance and needs in applications of super-resolved detection and imaging if a single particle can be trapped and manipulated accurately.However,it is difficult to achieve such trapping with high precision in conventional optical surface-wave tweezers.Here,we propose and experimentally demonstrate a new method to accurately trap and dynamically manipulate a single particle or a desired number of particles in holographic optical surface-wave tweezers.By tailoring the optical potential wells formed by surface waves,we achieved trapping of the targeted single particle while pushing away all surrounding particles and further dynamically controlling the particle by a holographic tweezers beam.We also prove that different particle samples,including gold particles and biological cells,can be applied in our system.This method can be used for different-type optical surface-wave tweezers,with significant potential applications in single-particle spectroscopy,particle sorting,nano-assembly,and others.
