A 1-bit electronically controlled metasurface reflectarray is presented to achieve beam steering with multiple polarization manipulations. A metsurface unit cell loaded by two PIN diodes is designed. By switching the ...A 1-bit electronically controlled metasurface reflectarray is presented to achieve beam steering with multiple polarization manipulations. A metsurface unit cell loaded by two PIN diodes is designed. By switching the two PIN diodes between ON and OFF states, the isotropic and anisotropic reflections can be flexibly achieved. For either the isotropic reflection or the anisotropic reflection, the two operation states achieve the reflection coefficients with approximately equal magnitude and 180°out of phase, thus giving rise to the isotropic/anisotropic 1-bit metasurface unit cells. With the 1-bit unit cells, a 12-by-12 metasurface reflectarray is optimally designed and fabricated. Under either y-or x-polarized incident wave illumination, the reflectarray can achieve the co-polarized and cross-polarized beam scanning, respectively, with the peak gains of 20.08 d Bi and 17.26 d Bi within the scan range of about ±50°. With the right-handed circular polarization(RHCP) excitation, the left-handed circular polarization(LHCP) radiation with the peak gain of 16.98 d Bic can be achieved within the scan range of ±50°. Good agreement between the experimental results and the simulation results are observed for 2D beam steering and polarization manipulation capabilities.展开更多
Plant regeneration is the first step to cotton biotechnology.We screened over 100 genotypes and found two genotypes,YZ-1 and Y668,which are very easy to regenerate.It takes about 5 to 6
Transmission line manipulations in a power system are necessary for the execution of preventative or corrective main- tenance in a network, thus ensuring the stability of the system. In this study, primal-dual interio...Transmission line manipulations in a power system are necessary for the execution of preventative or corrective main- tenance in a network, thus ensuring the stability of the system. In this study, primal-dual interior-point methods are used to minimize costs and losses in the generation and transmission of the predispatch active power flow in a hydroelectric system with previously scheduled line manipulations for preventative maintenance, over a period of twenty-four hours. The matrix structure of this problem and the modification that it imposes on the system is also broached in this study. From the computational standpoint, the effort required to solve a problem with or without line manipulations is similar, and the reasons for this are also discussed in this study. Computational results sustain our findings.展开更多
The degree and characteristics of physical degradation of macro-DNA molecules by common laboratory manipulations are reported. With linearized lambda-phage viral DNA as the model DNA, fragmentation of macro-DNA by var...The degree and characteristics of physical degradation of macro-DNA molecules by common laboratory manipulations are reported. With linearized lambda-phage viral DNA as the model DNA, fragmentation of macro-DNA by various indispensable laboratory manipulations were investigated using a high sensitivity flow cytometric setup. Investigated manipulations included pipetting, vortexing, rocking, freeze-thawing, ultrasonication and ultrafiltration. “Exhaustive counting” of the intact lambda DNA molecules following such manipulations enabled a quantitative assessment of the resulting fragmentation, which also revealed the type of degradation reflected in the fragmentation patterns. The use of high sensitivity flow cytometry was especially suited to investigate the degradation of dilute DNA solutions that may not be suitable for analysis using traditional methods. Notable findings of this study included: the boarderline-size of DNA chains in terms of susceptibility to shear stresses by such manipulations;discernable instability of nicked DNAs;shattering-fragmentation of DNAs by freeze-thawing or ultrasonication;effectiveness of some protection media;marked “self-protection effect” of concentrated DNA solutions. These findings support and refine our traditional knowledge on how to maintain the physical integrity of macro-DNA molecules against inevitable laboratory manipulations.展开更多
The corpus of this research was selected from the novel White Deer Plain,focusing on the inter-characteristics of various sign text modalities(fiction,TV lines and TV series),involving the interaction between sign tex...The corpus of this research was selected from the novel White Deer Plain,focusing on the inter-characteristics of various sign text modalities(fiction,TV lines and TV series),involving the interaction between sign text interpreters such as authors,scriptwriters,directors,actors,censors,post-producers,audiences,etc.Sign manipulations were adopted in these processes.It can be said that these sign processes from linguistic signs to TV drama cross-media and multimedia composite signs are typical sign text.Therefore,the research about complexity of the sign process attracts authors’interest.There are relatively few studies on the analysis of Bai Jiaxuan and Lu Zilin in White Deer Plain from the perspective of semiotics.This paper will analyze the differences in the characterizing process between novels and TV series from the perspective of sign manipulations.展开更多
Objective: To analyze the effects of twirling reinforcing and reducing manipulations on protein expression in parietal cortex of spontaneously hypertensive rats(SHRs), and elucidate the main mechanisms and differences...Objective: To analyze the effects of twirling reinforcing and reducing manipulations on protein expression in parietal cortex of spontaneously hypertensive rats(SHRs), and elucidate the main mechanisms and differences between two manipulations in hypertension treatment.Methods: Rats were randomly divided into the control, model, twirling reinforcing manipulation(TRFM),and twirling reducing manipulation(TRDM) groups. The control and model groups received catch and fixation stimulations once a day for 14 days. The TRFM and TRDM groups were intervened once a day for 20 min for 14 days. On days 0, 2, 6, 10, and 14 after acupuncture, rat systolic blood pressures(SBPs) were measured. Differential protein(DP) expression in the rat parietal cortices was detected. Thereafter, GO functional significance and KEGG pathway enrichment analyses were performed.Results: Compared with the model group, SBP of rats in the TRDM and TRFM groups decreased on days 6 and 10 of acupuncture, respectively(P=.009;P <.001). Moreover, SBP of the TRDM group was significantly lower than that of the TRFM group on days 10 and 14 of acupuncture(P=.015;P=.013).Compared with control group, 601 and 1040 DPs were up-and downregulated, respectively, in the model group. Compared with model group, 44 and 28 up-and downregulated DPs were expressed, respectively,in the TRFM group. Compared with model group, expression of 616 and 427 up-and downregulated DPs,respectively, was found in the TRDM group. After combining the results of GO and KEGG enrichment analyses, five and one pathways were found to be related to the central antihypertensive mechanism of the parietal cortex during twirling reducing and reinforcing manipulations, respectively.Conclusion: TRDM showed a more effective antihypertensive effect on SHRs than TRFM;this antihypertensive effect was related to the regulation of different proteins and their biological functions.展开更多
The source-sink ratio during grain filling is a critical factor that affects crop yield in wheat,and the main objective of this study was to determine the source-sink relations at both the canopy scale and the individ...The source-sink ratio during grain filling is a critical factor that affects crop yield in wheat,and the main objective of this study was to determine the source-sink relations at both the canopy scale and the individual culm level under two nitrogen(N)levels at the post-jointing stage.Nine widely-used cultivars were chosen for analyzing source-sink relations in southwestern China;and three typical cultivars of different plant types were subjected to artificial manipulation of the grain-filling source-sink ratio to supplement crop growth measurements.A field experiment was conducted over two consecutive seasons under two N rates(N+,150 kg ha^(-1);N-,60 kg ha^(-1)),and three manipulations were imposed after anthesis:control(Ct),removal of flag and penultimate leaves(Lr)and removal of spikelets on one side of each spike(Sr).The results showed that the single grain weights in the three cultivars were significantly decreased by Lr and increased by Sr,which demonstrated that wheat grain yield potential seems more source-limited than sink-limited during grain filling,but the source-sink balance was obviously changed by climatic variations and N deficient environments.Grain yield was highly associated with sink capacity(SICA),grain number,biomass,SPAD values,and leaf area index during grain filling,indicating a higher degree of source limitation with an increase in sink capacity.Therefore,source limitation should be taken into account by breeders when SICA is increased,especially under non-limiting conditions.Chuanmai 104,a half-compact type with a mid-sized spike and a long narrow upper leaf,showed relatively better performance in source-sink relations.Since this cultivar showed the characteristics of a lower reduction in grain weight after Lr,a larger increase after Sr,and a lower reduction in post-anthesis dry matter accumulation,then the greater current photosynthesis during grain filling contributed to the grain after source and sink manipulation.展开更多
Contactless acoustic manipulation of micro/nanoscale particles has attracted considerable attention owing to its near independence of the physical and chemical properties of the targets,making it universally applicabl...Contactless acoustic manipulation of micro/nanoscale particles has attracted considerable attention owing to its near independence of the physical and chemical properties of the targets,making it universally applicable to almost all biological systems.Thin-film bulk acoustic wave(BAW)resonators operating at gigahertz(GHz)frequencies have been demonstrated to generate localized high-speed microvortices through acoustic streaming effects.Benefitting from the strong drag forces of the high-speed vortices,BAW-enabled GHz acoustic streaming tweezers(AST)have been applied to the trapping and enrichment of particles ranging in size from micrometers to less than 100 nm.However,the behavior of particles in such 3D microvortex systems is still largely unknown.In this work,the particle behavior(trapping,enrichment,and separation)in GHz AST is studied by theoretical analyses,3D simulations,and microparticle tracking experiments.It is found that the particle motion in the vortices is determined mainly by the balance between the acoustic streaming drag force and the acoustic radiation force.This work can provide basic design principles for AST-based lab-on-a-chip systems for a variety of applications.展开更多
Acupuncture and moxibustion therapy non-specifically raises the pain threshold, relieves regional muscular tension, improves local blood circulation, accelerates elimination of algogenic substances such as acid metabo...Acupuncture and moxibustion therapy non-specifically raises the pain threshold, relieves regional muscular tension, improves local blood circulation, accelerates elimination of algogenic substances such as acid metabolites, and promotes neural regeneration and functional rehabilitation. However, the effects of acupuncture are synthetically influenced by multiple factors, which vary with acu-puncture point, intensity, and manipulation. The present study explored the analgesic effects and mechanisms of specific Sancai acupuncture manipulation for sciatica. Results revealed that Sancai acupuncture manipulation significantly reduced inflammatory factor interleukin-6 expression in the blood serum of rats with sciatica, exhibited anti-inflammatory effects and promoted rehabilitation of injured nerves. In addition, Sancai acupuncture manipulation exhibited superior curative effects over conventional acupuncture manipulation.展开更多
The life sciences field has experienced profound impacts from genome editing,a technology that enables precise genetic sequence modifications in living cells.Developments in genome editing have significantly propelled...The life sciences field has experienced profound impacts from genome editing,a technology that enables precise genetic sequence modifications in living cells.Developments in genome editing have significantly propelled advances in biomedicine and agricultural breeding.With the introduction of CRISPR as a genome editing tool in 2012[1],rapid progress has paved the way for emerging technologies such as base editing and prime editing[2,3].These sophisticated editing methods facilitate more accurate genome modifications and promise to profoundly impact the future of precision medicine,crop improvement,and even the de novo design of organisms.展开更多
Micro-LEDs(μLEDs)have advantages in terms of brightness,power consumption,and response speed.In addition,they can also be used as micro-sensors implanted in the body via flexible electronic skin.One of the key techni...Micro-LEDs(μLEDs)have advantages in terms of brightness,power consumption,and response speed.In addition,they can also be used as micro-sensors implanted in the body via flexible electronic skin.One of the key techniques involved in the fabrication ofμLED-based devices is transfer printing.Although numerous methods have been proposed for transfer printing,improving the yield ofμLED arrays is still a formidable task.In this paper,we propose a novel method for improving the yield ofμLED arrays transferred by the stamping method,using an innovative design of piezoelectrically driven asymmetric micro-gripper.Traditional grippers are too large to manipulateμLEDs,and therefore two micro-sized cantilevers are added at the gripper tips.AμLED manipulation system is constructed based on the micro-gripper together with a three-dimensional positioning system.Experimental results using this system show that it can be used successfully to manipulateμLED arrays.展开更多
Background High environmental temperatures induce heat stress in broiler chickens,affecting their health and pro-duction performance.Several dietary,managerial,and genetics strategies have been tested with some succes...Background High environmental temperatures induce heat stress in broiler chickens,affecting their health and pro-duction performance.Several dietary,managerial,and genetics strategies have been tested with some success in mitigating heat stress(HS)in broilers.Developing novel HS mitigation strategies for sustaining broiler production is critically needed.This study investigated the effects of pre-hatch thermal manipulation(TM)and post-hatch baica-lein supplementation on growth performance and health parameters in heat-stressed broilers.Results Six hundred fertile Cobb 500 eggs were incubated for 21 d.After candling on embryonic day(ED)10,238 eggs were thermally manipulated at 38.5℃ with 55%relative humidity(RH)from ED 12 to 18,then transferred to the hatcher(ED 19 to 21,standard temperature)and 236 eggs were incubated at a controlled temperature(37.5℃)till hatch.After hatch,180-day-old chicks from both groups were raised in 36 pens(n=10 birds/pen,6 replicates per treatment).The treatments were:1)Control,2)TM,3)control heat stress(CHS),4)thermal manipulation heat stress(TMHS),5)control heat stress supplement(CHSS),and 6)thermal manipulation heat stress supplement(TMHSS).All birds were raised under the standard environment for 21 d,followed by chronic heat stress from d 22 to 35(32–33℃ for 8 h)in the CHS,TMHS,CHSS,and TMHSS groups.A thermoneutral(22–24℃)environment was maintained in the Control and TM groups.RH was constant(50%±5%)throughout the trial.All the data were analyzed using one-way ANOVA in R and GraphPad software at P<0.05 and are presented as mean±SEM.Heat stress significantly decreased(P<0.05)the final body weight and ADG in CHS and TMHS groups compared to the other groups.Embryonic TM significantly increased(P<0.05)the expression of heat shock protein-related genes(HSP70,HSP90,and HSPH1)and antioxidant-related genes(GPX1 and TXN).TMHS birds showed a significant increment(P<0.05)in total cecal volatile fatty acid(VFA)concentration compared to the CHS birds.The cecal microbial analysis showed significant enrichment(P<0.05)in alpha and beta diversity and Coprococcus in the TMHSS group.Conclusions Pre-hatch TM and post-hatch baicalein supplementation in heat-stressed birds mitigate the detrimental effects of heat stress on chickens’growth performance,upregulate favorable gene expression,increase VFA produc-tion,and promote gut health by increasing beneficial microbial communities.展开更多
Bio-inspired macrostructure array(MAA,size:submillimeter to millimeter scale)materials with special wettability(MAAMs-SW)have attracted significant research attention due to their outstanding performance in many appli...Bio-inspired macrostructure array(MAA,size:submillimeter to millimeter scale)materials with special wettability(MAAMs-SW)have attracted significant research attention due to their outstanding performance in many applications,including oil repellency,liquid/droplet manipulation,anti-icing,heat transfer,water collection,and oil–water separation.In this review,we focus on recent developments in the theory,design,fabrication,and application of bio-inspired MAAMs-SW.We first review the history of the basic theory of special wettability and discuss representative structures and corresponding functions of some biological surfaces,thus setting the stage for the design and fabrication of bio-inspired MAAMs-SW.We then summarize the fabrication methods of special wetting MAAs in terms of three categories:additive manufacturing,subtractive manufacturing,and formative manufacturing,as well as their diverse functional applications,providing insights into the development of these MAAMs-SW.Finally,the challenges and directions of future research on bio-inspired MAAMs-SW are briefy addressed.Worldwide efforts,progress,and breakthroughs from surface engineering to functional applications elaborated herein will promote the practical application of bio-inspired MAAMs-SW.展开更多
The remarkable capabilities of 2D plasmonic surfaces in controlling optical waves havegarnered significant attention.However,the challenge of large-scale manufacturing of uniform,well-aligned,and tunable plasmonic sur...The remarkable capabilities of 2D plasmonic surfaces in controlling optical waves havegarnered significant attention.However,the challenge of large-scale manufacturing of uniform,well-aligned,and tunable plasmonic surfaces has hindered their industrialization.To address this,we present a groundbreaking tunable plasmonic platform design achieved throughmagnetic field(MF)assisted ultrafast laser direct deposition in air.Through precise control of metal nanoparticles(NPs),with cobalt(Co)serving as the model material,employing an MF,and fine-tuning ultrafast laser parameters,we have effectively converted coarse and non-uniform NPs into densely packed,uniform,and ultrafine NPs(~3 nm).This revolutionary advancement results in the creation of customizable plasmonic‘hot spots,’which play a pivotal role insurface-enhanced Raman spectroscopy(SERS)sensors.The profound impact of this designable plasmonic platform lies in its close association with plasmonic resonance and energyenhancement.When the plasmonic nanostructures resonate with incident light,they generate intense local electromagnetic fields,thus vastly increasing the Raman scattering signal.This enhancement leads to an outstanding 2–18 fold boost in SERS performance and unparalleled sensing sensitivity down to 10^(-10)M.Notably,the plasmonic platform also demonstratesrobustness,retaining its sensing capability even after undergoing 50 cycles of rinsing andre-loading of chemicals.Moreover,this work adheres to green manufacturing standards,making it an efficient and environmentally friendly method for customizing plasmonic‘hot spots’inSERS devices.Our study not only achieves the formation of high-density,uniform,and ultrafine NP arrays on a tunable plasmonic platform but also showcases the profound relation betweenplasmonic resonance and energy enhancement.The outstanding results observed in SERS sensors further emphasize the immense potential of this technology for energy-relatedapplications,including photocatalysis,photovoltaics,and clean water,propelling us closer to a sustainable and cleaner future.展开更多
The United Nations(UN)’s call for a decade of“ecosystem restoration”was prompted by the need to address the extensive impact of anthropogenic activities on natural ecosystems.Marine ecosystem restoration is increas...The United Nations(UN)’s call for a decade of“ecosystem restoration”was prompted by the need to address the extensive impact of anthropogenic activities on natural ecosystems.Marine ecosystem restoration is increasingly necessary due to increasing habitat degredation in deep waters(>200 m depth).At these depths,which are far beyond those accessible by divers,only established and emerging robotic platforms such as remotely operated vehicles(ROVs),autonomous underwater vehicles(AUVs),landers,and crawlers can operate through manipulators and multiparametric sensor arrays(e.g.,optoacoustic imaging,omics,and environmental probes).The use of advanced technologies for deep-sea ecosystem restoration can provide:①high-resolution three-dimensional(3D)imaging and acoustic mapping of substrates and key taxa,②physical manipulation of substrates and key taxa,③real-time supervision of remote operations and long-term ecological monitoring,and④the potential to work autonomously.Here,we describe how robotic platforms with in situ manipulation capabilities and payloads of innovative sensors could autonomously conduct active restoration and monitoring across large spatial scales.We expect that these devices will be particularly useful in deep-sea habitats,such as①reef-building cold-water corals,②soft-bottom bamboo corals,and③soft-bottom fishery resources that have already been damaged by offshore industries(i.e.,fishing and oil/gas).展开更多
Acoustic streaming enabled by a Lamb wave resonator(LWR)is efficient for particle trapping and enrichment in microfluidic channels.However,because Lamb waves combine the features of bulk acoustic waves and surface aco...Acoustic streaming enabled by a Lamb wave resonator(LWR)is efficient for particle trapping and enrichment in microfluidic channels.However,because Lamb waves combine the features of bulk acoustic waves and surface acoustic waves,the resulting acoustic streaming in the LWR occurs in multiple planes,and the particle flow behavior in this acoustofluidic system is largely unknown.Reported here are numerical simulations and laboratory experiments conducted to investigate the boundary conditions for particle motion inside a microvortex induced by an LWR.Upon dynamic capture,the particles’trajectories become orbital paths within an acoustic vortex.The suspended particles encounter two distinct acoustic phenomena,i.e.,the drag force resulting from acoustic streaming and the acoustic radiation force,which exert forces in various directions on the particles.When the acoustic radiation force and the fluid drag force are dominant for large and small particles in a mixed solution,respectively,the large particles reside within the vortex while the small particles remain at its periphery.Conversely,when the acoustic radiation force is dominant for both types of particles,the distribution pattern is reversed.展开更多
The use of‘Electrostatic tweezers'is a promising tool for droplet manipulation,but it faces many limitations in manipulating droplets on superhydrophobic surfaces.Here,we achieve noncontact and multifunctional dr...The use of‘Electrostatic tweezers'is a promising tool for droplet manipulation,but it faces many limitations in manipulating droplets on superhydrophobic surfaces.Here,we achieve noncontact and multifunctional droplet manipulation on Nepenthes-inspired lubricated slippery surfaces via triboelectric electrostatic tweezers(TETs).The TET manipulation of droplets on a slippery surface has many advantages over electrostatic droplet manipulation on a superhydrophobic surface.The electrostatic field induces the redistribution of the charges inside the neutral droplet,which causes the triboelectric charged rod to drive the droplet to move forward under the electrostatic force.Positively or negatively charged droplets can also be driven by TET based on electrostatic attraction and repulsion.TET enables us to manipulate droplets under diverse conditions,including anti-gravity climb,suspended droplets,corrosive liquids,low-surface-tension liquids(e.g.ethanol with a surface tension of 22.3 mN·m^(-1)),different droplet volumes(from 100 nl to 0.5 ml),passing through narrow slits,sliding over damaged areas,on various solid substrates,and even droplets in an enclosed system.Various droplet-related applications,such as motion guidance,motion switching,droplet-based microreactions,surface cleaning,surface defogging,liquid sorting,and cell labeling,can be easily achieved with TETs.展开更多
This paper proposes a new global fixed-time sliding mode control strategy for the trajectory tracking control of uncertain robotic manipulators.First,a fixed-time disturbance observer(FTDO) is designed to deal with th...This paper proposes a new global fixed-time sliding mode control strategy for the trajectory tracking control of uncertain robotic manipulators.First,a fixed-time disturbance observer(FTDO) is designed to deal with the adverse effects of model uncertainties and external disturbances in the manipulator systems.Then an adaptive scheme is used and the adaptive FTDO(AFTDO) is developed,so that the priori knowledge of the lumped disturbance is not required.Further,a new non-singular fast terminal sliding mode(NFTSM) surface is designed by using an arctan function,which helps to overcome the singularity problem and enhance the robustness of the system.Based on the estimation of the lumped disturbance by the AFTDO,a fixed-time non-singular fast terminal sliding mode controller(FTNFTSMC)is developed to guarantee the trajectory tracking errors converge to zero within a fixed time.The settling time is independent of the initial state of the system.In addition,the stability of the AFTDO and FTNFTSMC is strictly proved by using Lyapunov method.Finally,the fixed-time NFESM(FTNFTSM) algorithm is validated on a 2-link manipulator and comparisons with other existing sliding mode controllers(SMCs) are performed.The comparative results confirm that the FTNFTSMC has superior control performance.展开更多
基金Project supported by the National Key Research and Development Program of China (Grant No.2021YFA1401001)the National Natural Science Foundation of China (Grant No.62371355)。
文摘A 1-bit electronically controlled metasurface reflectarray is presented to achieve beam steering with multiple polarization manipulations. A metsurface unit cell loaded by two PIN diodes is designed. By switching the two PIN diodes between ON and OFF states, the isotropic and anisotropic reflections can be flexibly achieved. For either the isotropic reflection or the anisotropic reflection, the two operation states achieve the reflection coefficients with approximately equal magnitude and 180°out of phase, thus giving rise to the isotropic/anisotropic 1-bit metasurface unit cells. With the 1-bit unit cells, a 12-by-12 metasurface reflectarray is optimally designed and fabricated. Under either y-or x-polarized incident wave illumination, the reflectarray can achieve the co-polarized and cross-polarized beam scanning, respectively, with the peak gains of 20.08 d Bi and 17.26 d Bi within the scan range of about ±50°. With the right-handed circular polarization(RHCP) excitation, the left-handed circular polarization(LHCP) radiation with the peak gain of 16.98 d Bic can be achieved within the scan range of ±50°. Good agreement between the experimental results and the simulation results are observed for 2D beam steering and polarization manipulation capabilities.
文摘Plant regeneration is the first step to cotton biotechnology.We screened over 100 genotypes and found two genotypes,YZ-1 and Y668,which are very easy to regenerate.It takes about 5 to 6
文摘Transmission line manipulations in a power system are necessary for the execution of preventative or corrective main- tenance in a network, thus ensuring the stability of the system. In this study, primal-dual interior-point methods are used to minimize costs and losses in the generation and transmission of the predispatch active power flow in a hydroelectric system with previously scheduled line manipulations for preventative maintenance, over a period of twenty-four hours. The matrix structure of this problem and the modification that it imposes on the system is also broached in this study. From the computational standpoint, the effort required to solve a problem with or without line manipulations is similar, and the reasons for this are also discussed in this study. Computational results sustain our findings.
文摘The degree and characteristics of physical degradation of macro-DNA molecules by common laboratory manipulations are reported. With linearized lambda-phage viral DNA as the model DNA, fragmentation of macro-DNA by various indispensable laboratory manipulations were investigated using a high sensitivity flow cytometric setup. Investigated manipulations included pipetting, vortexing, rocking, freeze-thawing, ultrasonication and ultrafiltration. “Exhaustive counting” of the intact lambda DNA molecules following such manipulations enabled a quantitative assessment of the resulting fragmentation, which also revealed the type of degradation reflected in the fragmentation patterns. The use of high sensitivity flow cytometry was especially suited to investigate the degradation of dilute DNA solutions that may not be suitable for analysis using traditional methods. Notable findings of this study included: the boarderline-size of DNA chains in terms of susceptibility to shear stresses by such manipulations;discernable instability of nicked DNAs;shattering-fragmentation of DNAs by freeze-thawing or ultrasonication;effectiveness of some protection media;marked “self-protection effect” of concentrated DNA solutions. These findings support and refine our traditional knowledge on how to maintain the physical integrity of macro-DNA molecules against inevitable laboratory manipulations.
文摘The corpus of this research was selected from the novel White Deer Plain,focusing on the inter-characteristics of various sign text modalities(fiction,TV lines and TV series),involving the interaction between sign text interpreters such as authors,scriptwriters,directors,actors,censors,post-producers,audiences,etc.Sign manipulations were adopted in these processes.It can be said that these sign processes from linguistic signs to TV drama cross-media and multimedia composite signs are typical sign text.Therefore,the research about complexity of the sign process attracts authors’interest.There are relatively few studies on the analysis of Bai Jiaxuan and Lu Zilin in White Deer Plain from the perspective of semiotics.This paper will analyze the differences in the characterizing process between novels and TV series from the perspective of sign manipulations.
基金supported by the National Natural Science Foundation of China (81774413 and 82074553)。
文摘Objective: To analyze the effects of twirling reinforcing and reducing manipulations on protein expression in parietal cortex of spontaneously hypertensive rats(SHRs), and elucidate the main mechanisms and differences between two manipulations in hypertension treatment.Methods: Rats were randomly divided into the control, model, twirling reinforcing manipulation(TRFM),and twirling reducing manipulation(TRDM) groups. The control and model groups received catch and fixation stimulations once a day for 14 days. The TRFM and TRDM groups were intervened once a day for 20 min for 14 days. On days 0, 2, 6, 10, and 14 after acupuncture, rat systolic blood pressures(SBPs) were measured. Differential protein(DP) expression in the rat parietal cortices was detected. Thereafter, GO functional significance and KEGG pathway enrichment analyses were performed.Results: Compared with the model group, SBP of rats in the TRDM and TRFM groups decreased on days 6 and 10 of acupuncture, respectively(P=.009;P <.001). Moreover, SBP of the TRDM group was significantly lower than that of the TRFM group on days 10 and 14 of acupuncture(P=.015;P=.013).Compared with control group, 601 and 1040 DPs were up-and downregulated, respectively, in the model group. Compared with model group, 44 and 28 up-and downregulated DPs were expressed, respectively,in the TRFM group. Compared with model group, expression of 616 and 427 up-and downregulated DPs,respectively, was found in the TRDM group. After combining the results of GO and KEGG enrichment analyses, five and one pathways were found to be related to the central antihypertensive mechanism of the parietal cortex during twirling reducing and reinforcing manipulations, respectively.Conclusion: TRDM showed a more effective antihypertensive effect on SHRs than TRFM;this antihypertensive effect was related to the regulation of different proteins and their biological functions.
基金supported by the National Natural Science Foundation of China (31571590, 31972960)the earmarked fund for China Agriculture Research System of MOF and MARA (CARS-3-22)the Key Project of Crop Breeding of Sichuan Province, China (2021YFYZ0005)
文摘The source-sink ratio during grain filling is a critical factor that affects crop yield in wheat,and the main objective of this study was to determine the source-sink relations at both the canopy scale and the individual culm level under two nitrogen(N)levels at the post-jointing stage.Nine widely-used cultivars were chosen for analyzing source-sink relations in southwestern China;and three typical cultivars of different plant types were subjected to artificial manipulation of the grain-filling source-sink ratio to supplement crop growth measurements.A field experiment was conducted over two consecutive seasons under two N rates(N+,150 kg ha^(-1);N-,60 kg ha^(-1)),and three manipulations were imposed after anthesis:control(Ct),removal of flag and penultimate leaves(Lr)and removal of spikelets on one side of each spike(Sr).The results showed that the single grain weights in the three cultivars were significantly decreased by Lr and increased by Sr,which demonstrated that wheat grain yield potential seems more source-limited than sink-limited during grain filling,but the source-sink balance was obviously changed by climatic variations and N deficient environments.Grain yield was highly associated with sink capacity(SICA),grain number,biomass,SPAD values,and leaf area index during grain filling,indicating a higher degree of source limitation with an increase in sink capacity.Therefore,source limitation should be taken into account by breeders when SICA is increased,especially under non-limiting conditions.Chuanmai 104,a half-compact type with a mid-sized spike and a long narrow upper leaf,showed relatively better performance in source-sink relations.Since this cultivar showed the characteristics of a lower reduction in grain weight after Lr,a larger increase after Sr,and a lower reduction in post-anthesis dry matter accumulation,then the greater current photosynthesis during grain filling contributed to the grain after source and sink manipulation.
基金The authors gratefully acknowledge financial support from the National Key R&D Program of China(2018YFE0118700)the Natural Science Foundation of China(NSFC No.62174119)+1 种基金Tianjin Applied Basic Research and Advanced Technology(17JCJQJC43600)the 111 Project(B07014).
文摘Contactless acoustic manipulation of micro/nanoscale particles has attracted considerable attention owing to its near independence of the physical and chemical properties of the targets,making it universally applicable to almost all biological systems.Thin-film bulk acoustic wave(BAW)resonators operating at gigahertz(GHz)frequencies have been demonstrated to generate localized high-speed microvortices through acoustic streaming effects.Benefitting from the strong drag forces of the high-speed vortices,BAW-enabled GHz acoustic streaming tweezers(AST)have been applied to the trapping and enrichment of particles ranging in size from micrometers to less than 100 nm.However,the behavior of particles in such 3D microvortex systems is still largely unknown.In this work,the particle behavior(trapping,enrichment,and separation)in GHz AST is studied by theoretical analyses,3D simulations,and microparticle tracking experiments.It is found that the particle motion in the vortices is determined mainly by the balance between the acoustic streaming drag force and the acoustic radiation force.This work can provide basic design principles for AST-based lab-on-a-chip systems for a variety of applications.
基金the Science and Technology Development Program of High Institutes of Liaoning Provincial Educational Department,No.2007T118
文摘Acupuncture and moxibustion therapy non-specifically raises the pain threshold, relieves regional muscular tension, improves local blood circulation, accelerates elimination of algogenic substances such as acid metabolites, and promotes neural regeneration and functional rehabilitation. However, the effects of acupuncture are synthetically influenced by multiple factors, which vary with acu-puncture point, intensity, and manipulation. The present study explored the analgesic effects and mechanisms of specific Sancai acupuncture manipulation for sciatica. Results revealed that Sancai acupuncture manipulation significantly reduced inflammatory factor interleukin-6 expression in the blood serum of rats with sciatica, exhibited anti-inflammatory effects and promoted rehabilitation of injured nerves. In addition, Sancai acupuncture manipulation exhibited superior curative effects over conventional acupuncture manipulation.
文摘The life sciences field has experienced profound impacts from genome editing,a technology that enables precise genetic sequence modifications in living cells.Developments in genome editing have significantly propelled advances in biomedicine and agricultural breeding.With the introduction of CRISPR as a genome editing tool in 2012[1],rapid progress has paved the way for emerging technologies such as base editing and prime editing[2,3].These sophisticated editing methods facilitate more accurate genome modifications and promise to profoundly impact the future of precision medicine,crop improvement,and even the de novo design of organisms.
基金support from the Scientific Research Program of the Tianjin Education Commission(No.2019ZD08).
文摘Micro-LEDs(μLEDs)have advantages in terms of brightness,power consumption,and response speed.In addition,they can also be used as micro-sensors implanted in the body via flexible electronic skin.One of the key techniques involved in the fabrication ofμLED-based devices is transfer printing.Although numerous methods have been proposed for transfer printing,improving the yield ofμLED arrays is still a formidable task.In this paper,we propose a novel method for improving the yield ofμLED arrays transferred by the stamping method,using an innovative design of piezoelectrically driven asymmetric micro-gripper.Traditional grippers are too large to manipulateμLEDs,and therefore two micro-sized cantilevers are added at the gripper tips.AμLED manipulation system is constructed based on the micro-gripper together with a three-dimensional positioning system.Experimental results using this system show that it can be used successfully to manipulateμLED arrays.
基金The research was funded by a USDA Multistate(2052R)grant from the CTAHR University of Hawaii at Manoa to B.M.
文摘Background High environmental temperatures induce heat stress in broiler chickens,affecting their health and pro-duction performance.Several dietary,managerial,and genetics strategies have been tested with some success in mitigating heat stress(HS)in broilers.Developing novel HS mitigation strategies for sustaining broiler production is critically needed.This study investigated the effects of pre-hatch thermal manipulation(TM)and post-hatch baica-lein supplementation on growth performance and health parameters in heat-stressed broilers.Results Six hundred fertile Cobb 500 eggs were incubated for 21 d.After candling on embryonic day(ED)10,238 eggs were thermally manipulated at 38.5℃ with 55%relative humidity(RH)from ED 12 to 18,then transferred to the hatcher(ED 19 to 21,standard temperature)and 236 eggs were incubated at a controlled temperature(37.5℃)till hatch.After hatch,180-day-old chicks from both groups were raised in 36 pens(n=10 birds/pen,6 replicates per treatment).The treatments were:1)Control,2)TM,3)control heat stress(CHS),4)thermal manipulation heat stress(TMHS),5)control heat stress supplement(CHSS),and 6)thermal manipulation heat stress supplement(TMHSS).All birds were raised under the standard environment for 21 d,followed by chronic heat stress from d 22 to 35(32–33℃ for 8 h)in the CHS,TMHS,CHSS,and TMHSS groups.A thermoneutral(22–24℃)environment was maintained in the Control and TM groups.RH was constant(50%±5%)throughout the trial.All the data were analyzed using one-way ANOVA in R and GraphPad software at P<0.05 and are presented as mean±SEM.Heat stress significantly decreased(P<0.05)the final body weight and ADG in CHS and TMHS groups compared to the other groups.Embryonic TM significantly increased(P<0.05)the expression of heat shock protein-related genes(HSP70,HSP90,and HSPH1)and antioxidant-related genes(GPX1 and TXN).TMHS birds showed a significant increment(P<0.05)in total cecal volatile fatty acid(VFA)concentration compared to the CHS birds.The cecal microbial analysis showed significant enrichment(P<0.05)in alpha and beta diversity and Coprococcus in the TMHSS group.Conclusions Pre-hatch TM and post-hatch baicalein supplementation in heat-stressed birds mitigate the detrimental effects of heat stress on chickens’growth performance,upregulate favorable gene expression,increase VFA produc-tion,and promote gut health by increasing beneficial microbial communities.
基金supported by the National Defense Basic Scientific Research Project(No.JCKY2020210B001)the National Natural Science Foundation of China(No.U19A20103),the China Postdoctoral Science Foundation(No.2019M661184)+2 种基金the Jilin Province Scientific and Technological Development Program(No.YDZJ202101ZYTS025)the Jilin Province Young Science and Technology Talent Lift Project(No.QT202030)the Science and Technology Innovation Fund of CUST(No.XJJLG-2019-05)。
文摘Bio-inspired macrostructure array(MAA,size:submillimeter to millimeter scale)materials with special wettability(MAAMs-SW)have attracted significant research attention due to their outstanding performance in many applications,including oil repellency,liquid/droplet manipulation,anti-icing,heat transfer,water collection,and oil–water separation.In this review,we focus on recent developments in the theory,design,fabrication,and application of bio-inspired MAAMs-SW.We first review the history of the basic theory of special wettability and discuss representative structures and corresponding functions of some biological surfaces,thus setting the stage for the design and fabrication of bio-inspired MAAMs-SW.We then summarize the fabrication methods of special wetting MAAs in terms of three categories:additive manufacturing,subtractive manufacturing,and formative manufacturing,as well as their diverse functional applications,providing insights into the development of these MAAMs-SW.Finally,the challenges and directions of future research on bio-inspired MAAMs-SW are briefy addressed.Worldwide efforts,progress,and breakthroughs from surface engineering to functional applications elaborated herein will promote the practical application of bio-inspired MAAMs-SW.
基金the support by the Office of Naval Research’s NEPTUNE Program under the Grant Number N00014-16-1-3109the National Science Foundation CMMI NanoManufacturing Program。
文摘The remarkable capabilities of 2D plasmonic surfaces in controlling optical waves havegarnered significant attention.However,the challenge of large-scale manufacturing of uniform,well-aligned,and tunable plasmonic surfaces has hindered their industrialization.To address this,we present a groundbreaking tunable plasmonic platform design achieved throughmagnetic field(MF)assisted ultrafast laser direct deposition in air.Through precise control of metal nanoparticles(NPs),with cobalt(Co)serving as the model material,employing an MF,and fine-tuning ultrafast laser parameters,we have effectively converted coarse and non-uniform NPs into densely packed,uniform,and ultrafine NPs(~3 nm).This revolutionary advancement results in the creation of customizable plasmonic‘hot spots,’which play a pivotal role insurface-enhanced Raman spectroscopy(SERS)sensors.The profound impact of this designable plasmonic platform lies in its close association with plasmonic resonance and energyenhancement.When the plasmonic nanostructures resonate with incident light,they generate intense local electromagnetic fields,thus vastly increasing the Raman scattering signal.This enhancement leads to an outstanding 2–18 fold boost in SERS performance and unparalleled sensing sensitivity down to 10^(-10)M.Notably,the plasmonic platform also demonstratesrobustness,retaining its sensing capability even after undergoing 50 cycles of rinsing andre-loading of chemicals.Moreover,this work adheres to green manufacturing standards,making it an efficient and environmentally friendly method for customizing plasmonic‘hot spots’inSERS devices.Our study not only achieves the formation of high-density,uniform,and ultrafine NP arrays on a tunable plasmonic platform but also showcases the profound relation betweenplasmonic resonance and energy enhancement.The outstanding results observed in SERS sensors further emphasize the immense potential of this technology for energy-relatedapplications,including photocatalysis,photovoltaics,and clean water,propelling us closer to a sustainable and cleaner future.
基金conceived within the preparation of the Project Restoration of Deep-sea habitats to Rebuild European Seas (REDRESS):HORIZON CL6-2023-BIODIV-Restoration of deepsea habitats carried out within the framework of the activities of the Spanish Government through the"Severo Ochoa Centre Excellence"granted to ICM-CSIC (CEX2019-000928-S)and the Research Unit Tecnoterra (ICM-CSIC/UPC)supported the work were those of the Plan Estatal de Investigación Científica y Técnica y de Innovación 2017-2020 of the Spanish government:BITER-LANDER (PID2020-114732RB-C32),BITER-ECO (PID2020-114732RB-C31),BITER-AUV (PID2020-114732RB-C33),PLOME (PLEC2021-007525/AEI/10.13039/501100011033)+3 种基金the conceptual development,falls within the framework of EU LIFE Project ECOREST (LIFE20 NAT/ES/001270)funded by a Juan de la Cierva Formación Post-doctoral Fellowship (FJC2021-047734-Ifinanced by Ministerio de Cuyltura e Innovación/Agencia Española de Investigación and European Union NextGeneration EU/PRTR funds)funded by the Spanish Government (Agencia Española de Investigación-AEI)through the‘Severo Ochoa Centre of Excellence’accreditation (CEX2019-000928-S).
文摘The United Nations(UN)’s call for a decade of“ecosystem restoration”was prompted by the need to address the extensive impact of anthropogenic activities on natural ecosystems.Marine ecosystem restoration is increasingly necessary due to increasing habitat degredation in deep waters(>200 m depth).At these depths,which are far beyond those accessible by divers,only established and emerging robotic platforms such as remotely operated vehicles(ROVs),autonomous underwater vehicles(AUVs),landers,and crawlers can operate through manipulators and multiparametric sensor arrays(e.g.,optoacoustic imaging,omics,and environmental probes).The use of advanced technologies for deep-sea ecosystem restoration can provide:①high-resolution three-dimensional(3D)imaging and acoustic mapping of substrates and key taxa,②physical manipulation of substrates and key taxa,③real-time supervision of remote operations and long-term ecological monitoring,and④the potential to work autonomously.Here,we describe how robotic platforms with in situ manipulation capabilities and payloads of innovative sensors could autonomously conduct active restoration and monitoring across large spatial scales.We expect that these devices will be particularly useful in deep-sea habitats,such as①reef-building cold-water corals,②soft-bottom bamboo corals,and③soft-bottom fishery resources that have already been damaged by offshore industries(i.e.,fishing and oil/gas).
基金support of the National Natural Science Foundation of China (Grant No.62174119)the 111 Project (Grant No.B07014)the Foundation for Talent Scientists of Nanchang Institute for Microtechnology of Tianjin University.
文摘Acoustic streaming enabled by a Lamb wave resonator(LWR)is efficient for particle trapping and enrichment in microfluidic channels.However,because Lamb waves combine the features of bulk acoustic waves and surface acoustic waves,the resulting acoustic streaming in the LWR occurs in multiple planes,and the particle flow behavior in this acoustofluidic system is largely unknown.Reported here are numerical simulations and laboratory experiments conducted to investigate the boundary conditions for particle motion inside a microvortex induced by an LWR.Upon dynamic capture,the particles’trajectories become orbital paths within an acoustic vortex.The suspended particles encounter two distinct acoustic phenomena,i.e.,the drag force resulting from acoustic streaming and the acoustic radiation force,which exert forces in various directions on the particles.When the acoustic radiation force and the fluid drag force are dominant for large and small particles in a mixed solution,respectively,the large particles reside within the vortex while the small particles remain at its periphery.Conversely,when the acoustic radiation force is dominant for both types of particles,the distribution pattern is reversed.
基金supported by the USTC Research Funds of the Double First-Class Initiative(Nos.YD2090002013,YD234000009)the National Natural Science Foundation of China(Nos.61927814,62325507,52122511,U20A20290,62005262)。
文摘The use of‘Electrostatic tweezers'is a promising tool for droplet manipulation,but it faces many limitations in manipulating droplets on superhydrophobic surfaces.Here,we achieve noncontact and multifunctional droplet manipulation on Nepenthes-inspired lubricated slippery surfaces via triboelectric electrostatic tweezers(TETs).The TET manipulation of droplets on a slippery surface has many advantages over electrostatic droplet manipulation on a superhydrophobic surface.The electrostatic field induces the redistribution of the charges inside the neutral droplet,which causes the triboelectric charged rod to drive the droplet to move forward under the electrostatic force.Positively or negatively charged droplets can also be driven by TET based on electrostatic attraction and repulsion.TET enables us to manipulate droplets under diverse conditions,including anti-gravity climb,suspended droplets,corrosive liquids,low-surface-tension liquids(e.g.ethanol with a surface tension of 22.3 mN·m^(-1)),different droplet volumes(from 100 nl to 0.5 ml),passing through narrow slits,sliding over damaged areas,on various solid substrates,and even droplets in an enclosed system.Various droplet-related applications,such as motion guidance,motion switching,droplet-based microreactions,surface cleaning,surface defogging,liquid sorting,and cell labeling,can be easily achieved with TETs.
基金partially supported by the National Natural Science Foundation of China (62322315,61873237)Zhejiang Provincial Natural Science Foundation of China for Distinguished Young Scholars(LR22F030003)+2 种基金the National Key Rearch and Development Funding(2018YFB1403702)the Key Rearch and Development Programs of Zhejiang Province (2023C01224)Major Project of Science and Technology Innovation in Ningbo City (2019B1003)。
文摘This paper proposes a new global fixed-time sliding mode control strategy for the trajectory tracking control of uncertain robotic manipulators.First,a fixed-time disturbance observer(FTDO) is designed to deal with the adverse effects of model uncertainties and external disturbances in the manipulator systems.Then an adaptive scheme is used and the adaptive FTDO(AFTDO) is developed,so that the priori knowledge of the lumped disturbance is not required.Further,a new non-singular fast terminal sliding mode(NFTSM) surface is designed by using an arctan function,which helps to overcome the singularity problem and enhance the robustness of the system.Based on the estimation of the lumped disturbance by the AFTDO,a fixed-time non-singular fast terminal sliding mode controller(FTNFTSMC)is developed to guarantee the trajectory tracking errors converge to zero within a fixed time.The settling time is independent of the initial state of the system.In addition,the stability of the AFTDO and FTNFTSMC is strictly proved by using Lyapunov method.Finally,the fixed-time NFESM(FTNFTSM) algorithm is validated on a 2-link manipulator and comparisons with other existing sliding mode controllers(SMCs) are performed.The comparative results confirm that the FTNFTSMC has superior control performance.