Due to the small size,active mobility,and intrinsic softness,miniature soft robots hold promising po-tentials in reaching the deep region inside living bodies otherwise inaccessible with compelling agility,adaptabilit...Due to the small size,active mobility,and intrinsic softness,miniature soft robots hold promising po-tentials in reaching the deep region inside living bodies otherwise inaccessible with compelling agility,adaptability and safety.Various materials and actuation strategies have been developed for creating soft robots,among which,ferromagnetic soft materials that self-actuate in response to external magnetic fields have attracted worldwide attention due to their remote controllability and excellent compatibil-ity with biological tissues.This review presents comprehensive and systematic research advancements in the design,fabrication,and applications of ferromagnetic soft materials for miniature robots,providing in-sights into their potential use in biomedical fields and beyond.The programming strategies of ferromag-netic soft materials are summarized and classified,including mold-assisted programming,3D printing-assisted programming,microassembly-assisted programming,and magnetization reprogramming.Each approach possesses unique advantages in manipulating the magnetic responsiveness of ferromagnetic soft materials to achieve outstanding actuation and deformation performances.We then discuss the biomedi-cal applications of ferromagnetic soft material-based soft robots(e.g.,minimally invasive surgery,targeted delivery,and tissue engineering),highlighting their potentials in revolutionizing biomedical technologies.This review also points out the current challenges and provides insights into future research directions,which we hope can serve as a useful reference for the development of next-generation adaptive miniature robots.展开更多
Underwater robots have emerged as key tools for marine exploration because of their unique ability to traverse and navigate underwater regions,which pose challenges or dangers to human expeditions.Miniature underwater...Underwater robots have emerged as key tools for marine exploration because of their unique ability to traverse and navigate underwater regions,which pose challenges or dangers to human expeditions.Miniature underwater robots are widely employed in marine science,resource surveys,seabed geological investigations,and marine life observations,owing to their compact size,minimal noise,and agile move-ment.In recent years,researchers have developed diverse miniature underwater robots inspired by bion-ics and other disciplines,leading to many landmark achievements such as centimeter-level wireless control,movement speeds up to hundreds of millimeters per second,underwater three-dimensional motion capabilities,robot swarms,and underwater operation robots.This article offers an overview of the actuation methods and locomotion patterns utilized by miniature underwater robots and assesses the advantages and disadvantages of each method.Furthermore,the challenges confronting currently available miniature underwater robots are summarized,and future development trends are explored.展开更多
Inspired by bacterial motility mechanisms,Magnetic Helical Miniature Robots(MHMRs)exhibit promising applications in biomedical fields due to their efficient locomotion and compatibility with biological tissues.In this...Inspired by bacterial motility mechanisms,Magnetic Helical Miniature Robots(MHMRs)exhibit promising applications in biomedical fields due to their efficient locomotion and compatibility with biological tissues.In this review,we systematically survey the basics of MHMRs,from propulsion mechanism,magnetization and control methods to biomedical applications,aiming to provide readers with an easily understandable overview and fundamental knowledge on implementing MHMRs.The MHMRs are actuated by rotating magnetic fields,achieving steering and rotation through magnetic torque,and converting rotation into forward motion through the helical structure.Magnetization methods for MHMRs are reviewed into three types:attaching magnets,magnetic coatings,and magnetic powder doping.Additionally,this review discusses the control methods for MHMRs,covering imaging techniques,path tracking control—including classical control algorithms and increasingly popular learning-based methods,and swarm control.Subsequently,a comprehensive survey is conducted on the biomedical applications of MHMRs in the treatment of vascular diseases,drug delivery,cell delivery,and their integration with catheters.We finally provide a perspective about future challenges in MHMR research,including enhancing functional design capabilities,developing swarm-assisted independent control mechanisms,refining in vivo imaging techniques,and ensuring robust biocompatibility for safe medical use.展开更多
In industrial applications,climbing robots are widely used for climbing and detection of rough or smooth pipe surfaces.Inspired by the special claws of longicorn is that can crawl on rough surfaces and the array of ti...In industrial applications,climbing robots are widely used for climbing and detection of rough or smooth pipe surfaces.Inspired by the special claws of longicorn is that can crawl on rough surfaces and the array of tiny bristles of geckos that can crawl on smooth surfaces,a new type of wall-climbing robot for rough or smooth surfaces is proposed in this paper.The bionic palms of the robot are suggested with special bionic hooks inspired by the longicorn and bionic adhesive materials inspired by the gecko with a good performance on adhering on the surfaces.The special bionic hooks are manufactured by the 3D printing method and the bionic adhesive materials are made by the polymer print lithography technology.These two different bionic adhere accessory are used on the robot’s palm to achieve climbing on the different surfaces.This foldable climbing robot can not only bend its own body to accommodate the cylindrical contact surfaces of different diameters,but also crawl on vertical rough and smooth surfaces using their bionic palms.展开更多
This overview firstly introduces the state-of-the-art research progress in length scale-related fatigue performance of conventionally-fabricated metals evaluated by miniature specimens. Some key factors for size effec...This overview firstly introduces the state-of-the-art research progress in length scale-related fatigue performance of conventionally-fabricated metals evaluated by miniature specimens. Some key factors for size effects sensitive to microstructures including the specimen thickness, grain size and a ratio between them are highlighted to summarize some general rules for size effects. Then, ongoing research progress and new challenges in evaluating the fatigue performance of additive manufactured parts controlled by location-specific defects, microstructure heterogeneities as well as mechanical anisotropy using miniature specimen testing technique are discussed and addressed. Finally, a potential roadmap to establish a data-driven evaluation platform based on a large number of miniature specimen-based experiment data,theoretical computations and the ’big data’ analysis with machine learning is proposed. It is expected that this overview would provide a novel strategy for the realistic evaluation and fast qualification of fatigue properties of additive manufactured parts we have been facing to.展开更多
Alternative splicing is a cellular mechanism in eukaryotes that results in considerable diversity ofgene products. It plays an important role in several diseases and cellular signal regulation. Heat stress is a major ...Alternative splicing is a cellular mechanism in eukaryotes that results in considerable diversity ofgene products. It plays an important role in several diseases and cellular signal regulation. Heat stress is a major factor that induces immunosuppression in pigs. Little is known about the correlation between alternative splicing and heat stress in pigs. Therefore, this study aimed to clone, sequence and quantify the alternative splicing variant of toll-like receptor 4 （TLR4） in Bama miniature pigs （Sus scrofa domestica） following exposure to heat stress. The results showed that the second exon of TLR4 was spliced and 167 bp shorter in the alternative splicing variant, and the protein was putatively identified as a type of truncated membrane protein consisting of extramembrane, transmembrane and intramembrane regions lacking a signal peptide. Further, it was not a non- classical secretory protein. Five potential reference genes were screened for their potential as reliable standards to quantify the expression of TLR4 alternative spliced variants by real-time quantitative reverse-transcriptase polymerase chain reaction （qRT-PCR）. The stability of these reference genes was ranked using the geNorm and NormFinder programs, and ribosomal protein L4 （RPL4） and TATA box-binding protein （TBP） were found to be the two genes showing the most stable expression in the in vitro cultured peripheral blood mononuclear ceils （PBMCs） during heat shock. The mRNA level of the TLR4 gene （both classical and spliced） in stressed pigs increased significantly （P〈0.05）. Further, the expression levels of the alternative spliced variant of TLR4 （TLR4-ASV） showed a 2-3 folds increase in heat-stressed PBMCs as compared to control pigs. The results of the present study suggested that heat shock might modulate the host immune response by regulating the expressions of TLR4 and its alternative splicing variant.展开更多
An ultimate goal of neuroscience is to decipher the principles underlying neuronal information processing at the molecular,cellular,circuit,and system levels.The advent of miniature fluorescence microscopy has further...An ultimate goal of neuroscience is to decipher the principles underlying neuronal information processing at the molecular,cellular,circuit,and system levels.The advent of miniature fluorescence microscopy has furthered the quest by visualizing brain activities and structural dynamics in animals engaged in self-determined behaviors.In this brief review,we summarize recent advances in miniature fluorescence microscopy for neuroscience,focusing mostly on two mainstream solutions-miniature single-photon microscopy,and miniature two-photon microscopy.We discuss their technical advantages and limitations as well as unmet challenges for future improvement.Examples of preliminary applications are also presented to reflect on a new trend of brain imaging in experimental paradigms involving body movements,long and complex protocols,and even disease progression and aging.展开更多
With outstanding analytical performance and portability, miniature mass spectrometer is one of the most powerful tools for in-situ analysis. The miniaturization of mass spectrometers has lasted for more than ten years...With outstanding analytical performance and portability, miniature mass spectrometer is one of the most powerful tools for in-situ analysis. The miniaturization of mass spectrometers has lasted for more than ten years, during which a number of miniature mass spectrometers employing different techniques have been developed. Small-in-size, working at relatively high pressure region and capable of performing tandem mass spectrometry, ion trap is the most widely used mass analyzer in miniature mass spectrometer systems. The recent development of miniature ion trap mass spectrometer systems in the last ten years was reviewed in this paper. These instruments adopt different atmospheric pressure interfaces （APIs）, which are membrane inlets （MIs）, discontinuous atmospheric pressure interface （DAPI） and continuous atmospheric pressure interface （CAPI）. This review emphasizes on the mini mass spectrometry （MS） system that can be handheld by one person, but not the field-able ones that are too large to be hand-portable.展开更多
Kernel development plays an important role in determining kernel size in maize.Here we present the cloning and characterization of a maize gene,nitrate transporter1.5(NRT1.5),which controls small kernel phenotype by p...Kernel development plays an important role in determining kernel size in maize.Here we present the cloning and characterization of a maize gene,nitrate transporter1.5(NRT1.5),which controls small kernel phenotype by playing an important role in kernel development.A novel recessive small kernel mutant miniature2-m1(mn2-m1)was isolated from self-pollinated progenies of breeding materials.The mutant spontaneously showed small kernel character arresting both embryo and endosperm development at an early stage after pollination.Utilizing 21 polymorphic SSR markers,the mn2-m1 locus was limited to a 209.9-kb interval using 9176 recessive individuals of a BC1 segregating population from mn2-m1/B73.Only one annotated gene was located in this 209.9 kb region,Zm00001 d019294,which was predicted to encode nitrate transporter1.5(NRT1.5).Allelism tests confirmed that mn2-m1 was allelic to miniature2-m2(mn2-m2)and miniature2-710 B(mn2-710 B).The mn2-m1 and mn2-m2 alleles both had nucleotide deletions in the coding region resulting in premature termination,and the mn2-710 B allele had some missence mutations.Subcellular localization showed that Miniature 2(MN2)is localized in the plasma membrane.Quantitative real-time PCR(qRT-PCR)analysis revealed that the expression of MN2 and some genes involved in the basal endosperm transfer layer(BETL)and embryo surrounding region(ESR)development were affected in mn2-m1 seeds.These results suggested that MN2 plays an important role in maize seed development.展开更多
The automation of traditional Chinese medicine(TCM)pharmaceuticals has driven the development of process analysis from offline to online.Most of common online process analytical technologies are based on spectroscopy,...The automation of traditional Chinese medicine(TCM)pharmaceuticals has driven the development of process analysis from offline to online.Most of common online process analytical technologies are based on spectroscopy,making the identification and quantification of specific ingredients still a challenge.Herein,we developed a quality control(QC)system for monitoring TCM pharmaceuticals based on paper spray ionization miniature mass spectrometry(mini-MS).It enabled real-time online qualitative and quantitative detection of target ingredients in herbal extracts using mini-MS without chromatographic separation for the first time.Dynamic changes of alkaloids in Aconiti Lateralis Radix Praeparata(Fuzi)during decoction were used as examples,and the scientific principle of Fuzi compatibility was also investigated.Finally,the system was verified to work stably at the hourly level for pilot-scale extraction.This mini-MS based online analytical system is expected to be further developed for QC applications in a wider range of pharmaceutical processes.展开更多
The miniature design technology is an important trend in space exploration.Mass spectrometer is used extensively in the space environment detection.The miniature ion mass spectrometer utilizes a 127° cylindrical ...The miniature design technology is an important trend in space exploration.Mass spectrometer is used extensively in the space environment detection.The miniature ion mass spectrometer utilizes a 127° cylindrical electrostatic analyzer accompanied with a Time of Flight(TOF)unit based on ultrathin carbon foil to measure the energy spectra and composition of space plasma.The Time of Flight technique has been used broadly in space plasma measurement.A new type of miniature method for the ion mass spectrometer is introduced.The total mass of the instrument is1.8 kg and the total power consumption is 2.0 W.The calibration results show that the energy measurement range is 8.71~43550eV,the energy resolution is 1.86%and the ion mass from 1 amu(1 amu= 1.67 × 10^(-27)kg) to 58 amu can be resolved by the miniature mass spectrometer.The miniature ion mass spectrometer also has a potential to be increased in the field of view by an electrostatic deflecting system to extend its application in space plasma detection.The miniature ion mass spectrometer has been selected for pre-study of Chinese Strategic Priority Research Program on Space Science.展开更多
Objective:To report the outcomes and complications of open dismembered Anderson-Hynes pyeloplasty with miniature incision in treating children’s ureteropelvic junction obstruction.Methods:Between March 2007 and April...Objective:To report the outcomes and complications of open dismembered Anderson-Hynes pyeloplasty with miniature incision in treating children’s ureteropelvic junction obstruction.Methods:Between March 2007 and April 2011,109 children with a mean age of 2 years and 8 months old with ureteropelvic junction obstruction underwent open dismembered pyeloplasty.Clinical manifestations,radiographic assessments,incision size,surgery time,hospital stay,and complication rate were recorded.All patients had a documented ureteropelvic junction obstruction(having T1/2 more than 20 min in diethylenetriaminepentaacetic acid[DTPA]scan)with symptomatic stenosis or decreased kidney function(differential function<40%).Pyeloplasty was done by a retroperitoneal flank approach with miniature incision without pelvis reduction.One surgeon did all the surgeries.Success rate and complications were assessed in a 3-year follow-up.Results:Mean surgery time was 52 min(47e60 min).Incision size was 18e28 mm.Mean hospital stay was 3 days(2e8 days).The surgery was successful in 98.2%of patients with a mean follow-up time of 36 months(success was defined as disappearance of symptoms,if present,with improved ultrasound imaging results or Reno graphic parameters).The complication rate was 7.33%,including urinary leakage,double-J urethral stent dislocation and infection.Conclusion:Open dismembered pyeloplasty is a safe,technically feasible and effective therapy in treatment of children’s ureteropelvic junction obstruction.It takes a short time to do,requires a small incision and has few complications and a short recovery period.展开更多
Combined with the topology optimization,additive manufacturing can be used to fabricate metal parts with complex shapes.However,due to the geometrical variations and microstructure heterogeneities of the additively ma...Combined with the topology optimization,additive manufacturing can be used to fabricate metal parts with complex shapes.However,due to the geometrical variations and microstructure heterogeneities of the additively manufactured metal parts,new standards with the use of miniature specimens are required for the evalutation of the spatial distribution of mechanical properties throughout the parts.Here,we conduct a systematic investigation on tensile and fatigue properties of selective laser melted Inconel718 specimens with different thicknesses ranging from 0.1 mm to 1 mm.A“microstructure unit”that can well reflect the microstructure characteristic of selective laser melted materials is defined.The results reveal that premature necking with a dramatic drop in uniform elongation occurs if the ratio(t/d)of specimen thickness(t)to the"microstructure unit"size(d)is less than one.Premature necking is mainly attributed to the transition of strain localization behavior.We also propose a probabilistic statistical model for fatigue limit prediction based on the available fatigue data.It is recommended that the criterion of t/d≥4 should be satisfied to ensure that the yield strength,the uniform elongation,and the fatigue limit determined by the miniature specimens are comparable with those determined by standard specimens.The findings may provdie a guide to the establishment of miniature specimen-based standards toward the qualification of additively manufactured metal parts.展开更多
In this study, we developed a computer program for automatic prediction of watering time point by considering the environmental factors such as solar radiation, air temperature and relative humidity based on the multi...In this study, we developed a computer program for automatic prediction of watering time point by considering the environmental factors such as solar radiation, air temperature and relative humidity based on the multiple linear regression equation of leaf area and Penman Method. The experiments were carried out for a year in two watering experimental plots, one of which was controlled by pF value, and the other by the computer program. After comparing the results of the two plots, the following findings were obtained. In the computer program plot, the observed and predicted values of both leaf area and evapotranspiration indicated significant correlation at the 1% level, which suggested that the computer program had high prediction accuracy. In addition, no significant difference was observed between the two experimental plots with respects to the plant height, plant diameter, leaf area, leaf number, fresh weight, and dry weight, which demonstrated that the plants in the computer program plot had normal growth. On the other hand, although the number of flower buds and flowering shoots showed higher values at the end of certain cultivations in the computer program plot than those in pF value plot, we proposed that it was due to the effect of cumulative daily solar radiation in the greenhouse, rather than the watering. Thus, we have reached the conclusion that the computer program for automatic prediction of watering time point developed by this study has high applicability in miniature pot rose production.展开更多
Summary： Somatic cell nucleus transfer （SCNT） has been considered the most effective method for conserving endangered animals and expanding the quantity of adult animal models. Bama miniature pigs are genetically s...Summary： Somatic cell nucleus transfer （SCNT） has been considered the most effective method for conserving endangered animals and expanding the quantity of adult animal models. Bama miniature pigs are genetically stable and share similar biological features to humans. These pigs have been used to establish animal models for human diseases, and for many other applications. However, there is a pan- city of studies on the effect of ear fibroblasts derived from different age of adult Bama miniature pigs on nucleus transfer （NT）. The present study examined the NT efficiency of ear fibroblasts from fetal, new- born, 1-, 2-, 4-, 6-, 12-month-old miniature pigs by using trypan blue staining, flow cytometry and NT technique, etc., and the cell biological function and SCNT efficiency were compared between groups. The results showed that ear fibroblasts grew well after passage in each group. Spindle-shaped cells ini- tially predominated, and gradually declined with increase of culture time and replaced by polygonal cells. Irregular cell growth occurred in the 2-month-old group and the elder groups. The growth curves of the ear fibroblasts were ＂S-shaped＂ in different age groups. The cell proliferation of postnatal ear fi- broblasts, especially those from 2-, 4-, 6-, 12-month-old miniature pigs was significantly different from that of fetus ear fibroblasts （P〈0.05 or P〈0.01）. Two-month- and 4-month-old ear fibroblasts had a sig- nificantly higher proportion of G1 stage cells （85% to 91%） than those at 6 and 12 months （66% to 74%, P〈0.01）. The blastocyst rate of reconstructed embryos originating from newborn, 1-, 2-, 4-month-old donor pigs was 6.06% to 7.69% with no significant difference from that in fetus fibroblast group （8.06%）. It was concluded that 〈4-month-old adult Bama miniature pigs represent a better donor cell resource than elder pigs.展开更多
Following the current rapid development of the Internet of Things(IoT)and wireless condition monitoring systems,energy harvesters which use ambient energy have become a key part of achieving an energy-autonomous syste...Following the current rapid development of the Internet of Things(IoT)and wireless condition monitoring systems,energy harvesters which use ambient energy have become a key part of achieving an energy-autonomous system.Miniature wind energy harvesters have attracted widespread attention because of their great potential of power density as well as the rich availability of wind energy in many possible areas of application.This article provides readers with a glimpse into the state-of-the-art of miniature wind energy harvesters.The crucial factors for them to achieve high working efficiency under lower operational wind speed excitation are analyzed.Various potential energy coupling mechanisms are discussed in detail.Design approaches for broadening operational wind-speed-range given a variety of energy coupling mechanisms are also presented,as observed in the literature.Performance enhancement mechanisms including hydrodynamic configuration optimization,and non-linear vibration pick-up structure are reviewed.Conclusions are drawn and the outlook for each coupling mechanisms is presented.展开更多
The miniature pig is an optimal animal model for studying nervous system disease because of its physiologic and pathologic features. However, the rete mirabile composed of arteries and veins at the skull base limits t...The miniature pig is an optimal animal model for studying nervous system disease because of its physiologic and pathologic features. However, the rete mirabile composed of arteries and veins at the skull base limits their application as a model of ischemic stroke by middle cerebral artery occlusion. The present study investigated the possibility of establishing an ischemic stroke model in the miniature pig by blocking the skull base retia with sodium alginate microspheres. Three Bama miniature pigs were used. Using the monitor of C-arm X-ray machine, sodium aiginate microspheres （100-300 pm）, a novel embolic material, were injected through the femoral artery, aortic arch, common carotid artery, ascending pharyngeal artery and the retia. Results were evaluated using carotid arteriography, MRI, behavior observation and histology. The unilateral rete mirabile was completely blocked, resulting in disturbance in blood supply to the basal ganglia, astasia of the dght hind limb and salivation. MRI and hematoxylin-eosin staining showed an evident infarction focus in the basal ganglia. These findings indicate that sodium alginate microspheres are a suitable embolic material for blocking the skull base retia in miniature pigs to establish an ischemic stroke models.展开更多
基金the National Key R&D Program of China(No.2023YFE0208700)National Natural Sci-ence Foundation of China(No.92163109 and 52072095)+7 种基金Shenzhen Science and Technology Program(No.RCJC20231211090000001,GXWD20231129101105001)the National Natural Science Foundation of China(No.52205590)the Natural Science Foundation of Jiangsu Province(No.BK20220834)the Start-up Research Fund of Southeast University(No.RF1028623098)the State Key Laboratory of Robotics and Systems(HIT)(No.SKLRS-2024-KF-11)National Natural Science Foundation of China(No.52202348)Guangdong Basic and Applied Basic Research Foundation(No.2023A1515011491)Shenzhen Science and Technology Program(Nos.GXWD20220818224716001,KJZD20231023100302006).
文摘Due to the small size,active mobility,and intrinsic softness,miniature soft robots hold promising po-tentials in reaching the deep region inside living bodies otherwise inaccessible with compelling agility,adaptability and safety.Various materials and actuation strategies have been developed for creating soft robots,among which,ferromagnetic soft materials that self-actuate in response to external magnetic fields have attracted worldwide attention due to their remote controllability and excellent compatibil-ity with biological tissues.This review presents comprehensive and systematic research advancements in the design,fabrication,and applications of ferromagnetic soft materials for miniature robots,providing in-sights into their potential use in biomedical fields and beyond.The programming strategies of ferromag-netic soft materials are summarized and classified,including mold-assisted programming,3D printing-assisted programming,microassembly-assisted programming,and magnetization reprogramming.Each approach possesses unique advantages in manipulating the magnetic responsiveness of ferromagnetic soft materials to achieve outstanding actuation and deformation performances.We then discuss the biomedi-cal applications of ferromagnetic soft material-based soft robots(e.g.,minimally invasive surgery,targeted delivery,and tissue engineering),highlighting their potentials in revolutionizing biomedical technologies.This review also points out the current challenges and provides insights into future research directions,which we hope can serve as a useful reference for the development of next-generation adaptive miniature robots.
基金supported by the Natural Science Foundation of Jiangsu Province,China(BK20220813)the Fundamental Research Funds for the Central Universities(2242023K40014).
文摘Underwater robots have emerged as key tools for marine exploration because of their unique ability to traverse and navigate underwater regions,which pose challenges or dangers to human expeditions.Miniature underwater robots are widely employed in marine science,resource surveys,seabed geological investigations,and marine life observations,owing to their compact size,minimal noise,and agile move-ment.In recent years,researchers have developed diverse miniature underwater robots inspired by bion-ics and other disciplines,leading to many landmark achievements such as centimeter-level wireless control,movement speeds up to hundreds of millimeters per second,underwater three-dimensional motion capabilities,robot swarms,and underwater operation robots.This article offers an overview of the actuation methods and locomotion patterns utilized by miniature underwater robots and assesses the advantages and disadvantages of each method.Furthermore,the challenges confronting currently available miniature underwater robots are summarized,and future development trends are explored.
基金the financial support from the Research Institute for Advanced Manufacturing(RIAM)of The Hong Kong Polytechnic University(project Nos.1-CD9F and 1-CDK3)the Research Grants Council(RGC)of Hong Kong(project Nos.25200424 and 15206223)+2 种基金the GuangDong Basic and Applied Basic Research Foundation(project No.2023A1515110709)the Startup fund(project No.1-BE9L)of the Hong Kong Polytechnic Universitysupported by grant from the Research Committee of the Hong Kong Polytechnic University under student account code RN5Y.
文摘Inspired by bacterial motility mechanisms,Magnetic Helical Miniature Robots(MHMRs)exhibit promising applications in biomedical fields due to their efficient locomotion and compatibility with biological tissues.In this review,we systematically survey the basics of MHMRs,from propulsion mechanism,magnetization and control methods to biomedical applications,aiming to provide readers with an easily understandable overview and fundamental knowledge on implementing MHMRs.The MHMRs are actuated by rotating magnetic fields,achieving steering and rotation through magnetic torque,and converting rotation into forward motion through the helical structure.Magnetization methods for MHMRs are reviewed into three types:attaching magnets,magnetic coatings,and magnetic powder doping.Additionally,this review discusses the control methods for MHMRs,covering imaging techniques,path tracking control—including classical control algorithms and increasingly popular learning-based methods,and swarm control.Subsequently,a comprehensive survey is conducted on the biomedical applications of MHMRs in the treatment of vascular diseases,drug delivery,cell delivery,and their integration with catheters.We finally provide a perspective about future challenges in MHMR research,including enhancing functional design capabilities,developing swarm-assisted independent control mechanisms,refining in vivo imaging techniques,and ensuring robust biocompatibility for safe medical use.
基金This research was supported by the National Natural Science Foundation of China(No.11774355).
文摘In industrial applications,climbing robots are widely used for climbing and detection of rough or smooth pipe surfaces.Inspired by the special claws of longicorn is that can crawl on rough surfaces and the array of tiny bristles of geckos that can crawl on smooth surfaces,a new type of wall-climbing robot for rough or smooth surfaces is proposed in this paper.The bionic palms of the robot are suggested with special bionic hooks inspired by the longicorn and bionic adhesive materials inspired by the gecko with a good performance on adhering on the surfaces.The special bionic hooks are manufactured by the 3D printing method and the bionic adhesive materials are made by the polymer print lithography technology.These two different bionic adhere accessory are used on the robot’s palm to achieve climbing on the different surfaces.This foldable climbing robot can not only bend its own body to accommodate the cylindrical contact surfaces of different diameters,but also crawl on vertical rough and smooth surfaces using their bionic palms.
基金supported by the National Natural Science Foundation of China(NSFC,Grant Nos.51771207 and 51571199)
文摘This overview firstly introduces the state-of-the-art research progress in length scale-related fatigue performance of conventionally-fabricated metals evaluated by miniature specimens. Some key factors for size effects sensitive to microstructures including the specimen thickness, grain size and a ratio between them are highlighted to summarize some general rules for size effects. Then, ongoing research progress and new challenges in evaluating the fatigue performance of additive manufactured parts controlled by location-specific defects, microstructure heterogeneities as well as mechanical anisotropy using miniature specimen testing technique are discussed and addressed. Finally, a potential roadmap to establish a data-driven evaluation platform based on a large number of miniature specimen-based experiment data,theoretical computations and the ’big data’ analysis with machine learning is proposed. It is expected that this overview would provide a novel strategy for the realistic evaluation and fast qualification of fatigue properties of additive manufactured parts we have been facing to.
基金supported by grants from the National Natural Science Foundation of China (31101862)the China Postdoctor Science Foundation and Guangdong Ocean University Doctor Seed Grant, China (0712107)
文摘Alternative splicing is a cellular mechanism in eukaryotes that results in considerable diversity ofgene products. It plays an important role in several diseases and cellular signal regulation. Heat stress is a major factor that induces immunosuppression in pigs. Little is known about the correlation between alternative splicing and heat stress in pigs. Therefore, this study aimed to clone, sequence and quantify the alternative splicing variant of toll-like receptor 4 （TLR4） in Bama miniature pigs （Sus scrofa domestica） following exposure to heat stress. The results showed that the second exon of TLR4 was spliced and 167 bp shorter in the alternative splicing variant, and the protein was putatively identified as a type of truncated membrane protein consisting of extramembrane, transmembrane and intramembrane regions lacking a signal peptide. Further, it was not a non- classical secretory protein. Five potential reference genes were screened for their potential as reliable standards to quantify the expression of TLR4 alternative spliced variants by real-time quantitative reverse-transcriptase polymerase chain reaction （qRT-PCR）. The stability of these reference genes was ranked using the geNorm and NormFinder programs, and ribosomal protein L4 （RPL4） and TATA box-binding protein （TBP） were found to be the two genes showing the most stable expression in the in vitro cultured peripheral blood mononuclear ceils （PBMCs） during heat shock. The mRNA level of the TLR4 gene （both classical and spliced） in stressed pigs increased significantly （P〈0.05）. Further, the expression levels of the alternative spliced variant of TLR4 （TLR4-ASV） showed a 2-3 folds increase in heat-stressed PBMCs as compared to control pigs. The results of the present study suggested that heat shock might modulate the host immune response by regulating the expressions of TLR4 and its alternative splicing variant.
基金We thank Dr.Zhe Zhao and Dr.Haitao Wu for helping with the experiments for Fig.2D,and Dr.Weijian Zong for discussion.This work was supported by grants from the National Natural Science Foundation of China(31327901,31570839,61975002,31830036,31821091,and 8182780030)the Major State Basic Research Program of China(2016 YFA0500400 and 2016YFA0500403)and the National Postdoctoral Program for Innovative Talents of China(BX20190011).
文摘An ultimate goal of neuroscience is to decipher the principles underlying neuronal information processing at the molecular,cellular,circuit,and system levels.The advent of miniature fluorescence microscopy has furthered the quest by visualizing brain activities and structural dynamics in animals engaged in self-determined behaviors.In this brief review,we summarize recent advances in miniature fluorescence microscopy for neuroscience,focusing mostly on two mainstream solutions-miniature single-photon microscopy,and miniature two-photon microscopy.We discuss their technical advantages and limitations as well as unmet challenges for future improvement.Examples of preliminary applications are also presented to reflect on a new trend of brain imaging in experimental paradigms involving body movements,long and complex protocols,and even disease progression and aging.
基金supported by the National Natural Science Foundation of China (Nos. 21475010, 61635003)Beijing Natural Science Foundation (No. 16L00065)State Key Laboratory Explosion Science and Technology (No. YBKT16-17)
文摘With outstanding analytical performance and portability, miniature mass spectrometer is one of the most powerful tools for in-situ analysis. The miniaturization of mass spectrometers has lasted for more than ten years, during which a number of miniature mass spectrometers employing different techniques have been developed. Small-in-size, working at relatively high pressure region and capable of performing tandem mass spectrometry, ion trap is the most widely used mass analyzer in miniature mass spectrometer systems. The recent development of miniature ion trap mass spectrometer systems in the last ten years was reviewed in this paper. These instruments adopt different atmospheric pressure interfaces （APIs）, which are membrane inlets （MIs）, discontinuous atmospheric pressure interface （DAPI） and continuous atmospheric pressure interface （CAPI）. This review emphasizes on the mini mass spectrometry （MS） system that can be handheld by one person, but not the field-able ones that are too large to be hand-portable.
基金supported by the National Key Research and Development Program of China(2017YFD0101204)the National Natural Science Foundation of China(31701443)+1 种基金the Agricultural Science and Technology Innovation Project of the Shandong Academy of Agricultural Sciences,China(CXGC2017B01)the Natural Science Foundation of Shandong Province,China(ZR2016CB52)。
文摘Kernel development plays an important role in determining kernel size in maize.Here we present the cloning and characterization of a maize gene,nitrate transporter1.5(NRT1.5),which controls small kernel phenotype by playing an important role in kernel development.A novel recessive small kernel mutant miniature2-m1(mn2-m1)was isolated from self-pollinated progenies of breeding materials.The mutant spontaneously showed small kernel character arresting both embryo and endosperm development at an early stage after pollination.Utilizing 21 polymorphic SSR markers,the mn2-m1 locus was limited to a 209.9-kb interval using 9176 recessive individuals of a BC1 segregating population from mn2-m1/B73.Only one annotated gene was located in this 209.9 kb region,Zm00001 d019294,which was predicted to encode nitrate transporter1.5(NRT1.5).Allelism tests confirmed that mn2-m1 was allelic to miniature2-m2(mn2-m2)and miniature2-710 B(mn2-710 B).The mn2-m1 and mn2-m2 alleles both had nucleotide deletions in the coding region resulting in premature termination,and the mn2-710 B allele had some missence mutations.Subcellular localization showed that Miniature 2(MN2)is localized in the plasma membrane.Quantitative real-time PCR(qRT-PCR)analysis revealed that the expression of MN2 and some genes involved in the basal endosperm transfer layer(BETL)and embryo surrounding region(ESR)development were affected in mn2-m1 seeds.These results suggested that MN2 plays an important role in maize seed development.
基金supported by Ministry of Science and Technology of the People's Republic of China(Grant No.:2022YFC3502300)Beijing Natural Science Foundation(Grant No.:L222150)+2 种基金the National Natural Science Foundation of China(Grant No.:82072247)the second batch of“Ten thousand plan”National High Level Talents Special Support Plan(Grant No.:W02020052)Beijing University of Chinese Medicine(Grant Nos.:XJYS21005,JY21024,MSGZF-202001,2022-syjs-05,and 2022-syjs-10).
文摘The automation of traditional Chinese medicine(TCM)pharmaceuticals has driven the development of process analysis from offline to online.Most of common online process analytical technologies are based on spectroscopy,making the identification and quantification of specific ingredients still a challenge.Herein,we developed a quality control(QC)system for monitoring TCM pharmaceuticals based on paper spray ionization miniature mass spectrometry(mini-MS).It enabled real-time online qualitative and quantitative detection of target ingredients in herbal extracts using mini-MS without chromatographic separation for the first time.Dynamic changes of alkaloids in Aconiti Lateralis Radix Praeparata(Fuzi)during decoction were used as examples,and the scientific principle of Fuzi compatibility was also investigated.Finally,the system was verified to work stably at the hourly level for pilot-scale extraction.This mini-MS based online analytical system is expected to be further developed for QC applications in a wider range of pharmaceutical processes.
基金Supported by the Strategic Priority Research Program on Space Science,the Chinese Academy of Sciences(XDA04071700,XDA04060202)
文摘The miniature design technology is an important trend in space exploration.Mass spectrometer is used extensively in the space environment detection.The miniature ion mass spectrometer utilizes a 127° cylindrical electrostatic analyzer accompanied with a Time of Flight(TOF)unit based on ultrathin carbon foil to measure the energy spectra and composition of space plasma.The Time of Flight technique has been used broadly in space plasma measurement.A new type of miniature method for the ion mass spectrometer is introduced.The total mass of the instrument is1.8 kg and the total power consumption is 2.0 W.The calibration results show that the energy measurement range is 8.71~43550eV,the energy resolution is 1.86%and the ion mass from 1 amu(1 amu= 1.67 × 10^(-27)kg) to 58 amu can be resolved by the miniature mass spectrometer.The miniature ion mass spectrometer also has a potential to be increased in the field of view by an electrostatic deflecting system to extend its application in space plasma detection.The miniature ion mass spectrometer has been selected for pre-study of Chinese Strategic Priority Research Program on Space Science.
文摘Objective:To report the outcomes and complications of open dismembered Anderson-Hynes pyeloplasty with miniature incision in treating children’s ureteropelvic junction obstruction.Methods:Between March 2007 and April 2011,109 children with a mean age of 2 years and 8 months old with ureteropelvic junction obstruction underwent open dismembered pyeloplasty.Clinical manifestations,radiographic assessments,incision size,surgery time,hospital stay,and complication rate were recorded.All patients had a documented ureteropelvic junction obstruction(having T1/2 more than 20 min in diethylenetriaminepentaacetic acid[DTPA]scan)with symptomatic stenosis or decreased kidney function(differential function<40%).Pyeloplasty was done by a retroperitoneal flank approach with miniature incision without pelvis reduction.One surgeon did all the surgeries.Success rate and complications were assessed in a 3-year follow-up.Results:Mean surgery time was 52 min(47e60 min).Incision size was 18e28 mm.Mean hospital stay was 3 days(2e8 days).The surgery was successful in 98.2%of patients with a mean follow-up time of 36 months(success was defined as disappearance of symptoms,if present,with improved ultrasound imaging results or Reno graphic parameters).The complication rate was 7.33%,including urinary leakage,double-J urethral stent dislocation and infection.Conclusion:Open dismembered pyeloplasty is a safe,technically feasible and effective therapy in treatment of children’s ureteropelvic junction obstruction.It takes a short time to do,requires a small incision and has few complications and a short recovery period.
基金supported by the National Natural Science Foundation of China(NSFC,Grant No.51771207)the project of‘Manufacturing the swirl nozzles of the high-pressure turbine by selective laser melting’the Fundamental Research Project of Shenyang National Laboratory for Materials Science(No.L2019R18)。
文摘Combined with the topology optimization,additive manufacturing can be used to fabricate metal parts with complex shapes.However,due to the geometrical variations and microstructure heterogeneities of the additively manufactured metal parts,new standards with the use of miniature specimens are required for the evalutation of the spatial distribution of mechanical properties throughout the parts.Here,we conduct a systematic investigation on tensile and fatigue properties of selective laser melted Inconel718 specimens with different thicknesses ranging from 0.1 mm to 1 mm.A“microstructure unit”that can well reflect the microstructure characteristic of selective laser melted materials is defined.The results reveal that premature necking with a dramatic drop in uniform elongation occurs if the ratio(t/d)of specimen thickness(t)to the"microstructure unit"size(d)is less than one.Premature necking is mainly attributed to the transition of strain localization behavior.We also propose a probabilistic statistical model for fatigue limit prediction based on the available fatigue data.It is recommended that the criterion of t/d≥4 should be satisfied to ensure that the yield strength,the uniform elongation,and the fatigue limit determined by the miniature specimens are comparable with those determined by standard specimens.The findings may provdie a guide to the establishment of miniature specimen-based standards toward the qualification of additively manufactured metal parts.
基金supported by the Science Founda-tion of Guangxi Zhuang Autonomous Region, China(0832002)
文摘In this study, we developed a computer program for automatic prediction of watering time point by considering the environmental factors such as solar radiation, air temperature and relative humidity based on the multiple linear regression equation of leaf area and Penman Method. The experiments were carried out for a year in two watering experimental plots, one of which was controlled by pF value, and the other by the computer program. After comparing the results of the two plots, the following findings were obtained. In the computer program plot, the observed and predicted values of both leaf area and evapotranspiration indicated significant correlation at the 1% level, which suggested that the computer program had high prediction accuracy. In addition, no significant difference was observed between the two experimental plots with respects to the plant height, plant diameter, leaf area, leaf number, fresh weight, and dry weight, which demonstrated that the plants in the computer program plot had normal growth. On the other hand, although the number of flower buds and flowering shoots showed higher values at the end of certain cultivations in the computer program plot than those in pF value plot, we proposed that it was due to the effect of cumulative daily solar radiation in the greenhouse, rather than the watering. Thus, we have reached the conclusion that the computer program for automatic prediction of watering time point developed by this study has high applicability in miniature pot rose production.
基金supported by the grants from the National Natural Science Foundation of China(No.31000546)National High-tech Research & Development Program of China(863 Program)(No.2012AA020603)+1 种基金National Science and Technology Major Project of China(No.2014zx08009-003-006)Rongchang Youth Foundation and Fundamental Research Funds of Southwest University(No.XDJK2012C097)
文摘Summary： Somatic cell nucleus transfer （SCNT） has been considered the most effective method for conserving endangered animals and expanding the quantity of adult animal models. Bama miniature pigs are genetically stable and share similar biological features to humans. These pigs have been used to establish animal models for human diseases, and for many other applications. However, there is a pan- city of studies on the effect of ear fibroblasts derived from different age of adult Bama miniature pigs on nucleus transfer （NT）. The present study examined the NT efficiency of ear fibroblasts from fetal, new- born, 1-, 2-, 4-, 6-, 12-month-old miniature pigs by using trypan blue staining, flow cytometry and NT technique, etc., and the cell biological function and SCNT efficiency were compared between groups. The results showed that ear fibroblasts grew well after passage in each group. Spindle-shaped cells ini- tially predominated, and gradually declined with increase of culture time and replaced by polygonal cells. Irregular cell growth occurred in the 2-month-old group and the elder groups. The growth curves of the ear fibroblasts were ＂S-shaped＂ in different age groups. The cell proliferation of postnatal ear fi- broblasts, especially those from 2-, 4-, 6-, 12-month-old miniature pigs was significantly different from that of fetus ear fibroblasts （P〈0.05 or P〈0.01）. Two-month- and 4-month-old ear fibroblasts had a sig- nificantly higher proportion of G1 stage cells （85% to 91%） than those at 6 and 12 months （66% to 74%, P〈0.01）. The blastocyst rate of reconstructed embryos originating from newborn, 1-, 2-, 4-month-old donor pigs was 6.06% to 7.69% with no significant difference from that in fetus fibroblast group （8.06%）. It was concluded that 〈4-month-old adult Bama miniature pigs represent a better donor cell resource than elder pigs.
基金the financial support from National Natural Science Foundation of China Grant No.61604023National Natural Science Foundation of China(Grant No.61804016)。
文摘Following the current rapid development of the Internet of Things(IoT)and wireless condition monitoring systems,energy harvesters which use ambient energy have become a key part of achieving an energy-autonomous system.Miniature wind energy harvesters have attracted widespread attention because of their great potential of power density as well as the rich availability of wind energy in many possible areas of application.This article provides readers with a glimpse into the state-of-the-art of miniature wind energy harvesters.The crucial factors for them to achieve high working efficiency under lower operational wind speed excitation are analyzed.Various potential energy coupling mechanisms are discussed in detail.Design approaches for broadening operational wind-speed-range given a variety of energy coupling mechanisms are also presented,as observed in the literature.Performance enhancement mechanisms including hydrodynamic configuration optimization,and non-linear vibration pick-up structure are reviewed.Conclusions are drawn and the outlook for each coupling mechanisms is presented.
基金supported by the Science and Technology Support Program of Beijing Science and Technology Committee,No.Z101107052210004
文摘The miniature pig is an optimal animal model for studying nervous system disease because of its physiologic and pathologic features. However, the rete mirabile composed of arteries and veins at the skull base limits their application as a model of ischemic stroke by middle cerebral artery occlusion. The present study investigated the possibility of establishing an ischemic stroke model in the miniature pig by blocking the skull base retia with sodium alginate microspheres. Three Bama miniature pigs were used. Using the monitor of C-arm X-ray machine, sodium aiginate microspheres （100-300 pm）, a novel embolic material, were injected through the femoral artery, aortic arch, common carotid artery, ascending pharyngeal artery and the retia. Results were evaluated using carotid arteriography, MRI, behavior observation and histology. The unilateral rete mirabile was completely blocked, resulting in disturbance in blood supply to the basal ganglia, astasia of the dght hind limb and salivation. MRI and hematoxylin-eosin staining showed an evident infarction focus in the basal ganglia. These findings indicate that sodium alginate microspheres are a suitable embolic material for blocking the skull base retia in miniature pigs to establish an ischemic stroke models.
