Plasma-activated hydrogel:fabrication,functionalization,and effective biological model

Hydrogels are biomaterials with 3D networks of hydrophilic polymers.The generation of hydrogels is turning to the development of hydrogels with the help of enabling technologies.Plasma can tailor the hydrogels’properties through simultaneous physical and chemical actions,resulting in an emerging technology of plasma-activated hydrogels(PAH).PAH can be divided into functional PAH and biological tissue model PAH.This review systematically introduces the plasma sources,plasma etching polymer surface,and plasma cross-linking involved in the fabrication of PAH.The‘diffusion-drift-reaction model’is used to study the microscopic physicochemical interaction between plasma and biological tissue PAH models.Finally,the main achievements of PAH,including wound treatment,sterilization,3D tumor model,etc,and their development trends are discussed.

On Dual-Mode Driving Control Method for a Novel Unmanned Tractor With High Safety and Reliability

Due to the non-standardization and complexity of the farmland environment,it is always a huge challenge for tractors to achieve fully autonomy(work at Self-driving mode)all the time in agricultural industry.Whereas,when tractors work in the Tele-driving(or Remote driving)mode,the operators are prone to fatigue because they need to concentrate for long periods of time.In response to these,a dual-mode control strategy was proposed to integrate the advantages of both approaches,i.e.,by combing Self-driving at most of the time with Tele-driving under special(complex and hazardous)conditions through switching control method.First,the state switcher was proposed,which is used for smooth switching the driving modes according to different working states of a tractor.Then,the state switching control law and the corresponding subsystem tracking controllers were designed.Finally,the effectiveness and superiority of the dualmode control method were evaluated via actual experimental testing of a tractor whose results show that the proposed control method can switch smoothly,stably,and efficiently between the two driving modes automatically.The average control accuracy has been improved by 20%and 15%respectively,compared to the conventional Tele-driving control and Self-driving control with low-precision navigation.In conclusion,the proposed dualmode control method can not only satisfy the operation in the complex and changeable farmland environment,but also free drivers from high-intensity and fatiguing work.This provides a perfect application solution and theoretical support for the intelligentization of unmanned farm agricultural machinery with high safety and reliability.

Isotope constraints on seasonal dynamics of nitrogen in Zhanjiang Bay, a typical mariculture bay in South China

Eutrophication in coastal waters has been increasing remarkably,severely impacting the water quality in mariculture bays.In this study,we conducted multiple isotopic measurements on suspended particulate nitrogen(δ^(15)N-PN) and dissolved nitrate(δ^(15)N-NO_(3)^(-)and δ^(18)O-NO_(3)^(-)) in Zhanjiang Bay,a typical mariculture bay with a high level of eutrophication in South China,to investigate the changes in nitrogen sources and their cycling between the rainy and dry seasons.During the rainy season,the study found no significant relation between δ^(15)NPN and δ^(15)N-NO_(3)^(-)due to the impact of heavy rainfall and terrestrial erosion.In the upper bay,a slight nitrate loss and slightly higher δ_(15)N-NO_(3)^(-)and δ^(18)O-NO_(3)^(-)values were observed,attributed to intense physical sedimentwater interactions.Despite some fluctuations,nitrate concentrations in the lower bay mainly aligned with the theoretical mixing line during the rainy season,suggesting that nitrate was primarily influenced by terrestrial erosion and that nitrate isotopes resembled the source.Consequently,the isotopic values of nitrate can be used for source apportionment in the rainy season.The results indicated that soil nitrogen(36%) and manure and sewage(33%) were the predominant nitrogen sources contributing to nitrogen loads during this period.In contrast,the dry season saw a deficient ammonium concentration(<0.2 μmol/L) in the bay,due to nearly complete consumption by phytoplankton during the red tide period.Additionally,the significant loss of nitrate and simultaneous increase in the stable isotopes of dissolved and particulate nitrogen suggest a strong coupling of assimilation and mineralization during the dry season.More active biogeochemical processes during the dry season may be related to decreased runoff and increased water retention time.Overall,our study illustrated the major seasonal nitrogen sources and their dynamics in Zhanjiang B ay,providing valuable insights for formulating effective policies to mitigate eutrophication in mariculture bays.

丙烯酸浓度对聚羧酸减水剂聚合速率的影响及反应级数

以异戊烯基聚氧乙烯醚(TPEG)为大单体、丙烯酸(AA)为小单体、过硫酸铵(APS)为引发剂、甲基丙烯磺酸钠(MAS)为链转移剂,采用一次投料水溶液自由基共聚法合成聚羧酸减水剂(PCE)。改变酸醚比即AA初始浓度合成PCE,分析了AA浓度对PCE聚合速率的影响,并进一步拟合了AA的反应级数。研究表明,随着PCE反应进程的推移,AA浓度减小、AA转化率增大。PCE聚合速率随着AA初始浓度的增大而增加,当AA初始浓度由0.2376 mol/L升至0.9008 mol/L时,聚合速率由1.3×10^(-4)mol/(L·s)升至4.8×10^(-4)mol/(L·s),AA的反应级数为0.9554。

Devitrification of TeO_2-doped Fluoroaluminate Glass

Crystallization behavior of the glass system AlF3-MgF2-CaF2-SrF2-BaF2-YFa-TeO2 （AMCSBY-TeO2） was studied by the nonisothermal method using differential thermal analysis. The activation energy E and Avrami exponent g were determined by nonisothermal method. It is found that the value of E varies with increasing TeO2 and reaches a minimum at 10 mol fraction TeO2, while g decreases from 3.65 to 1.78 with the addition of TeO2. X-ray diffraction shows that Ba2TeaOs, MgTe205, and SrTeOa phase formed when the glasses were reheated. The addition of TeO2 changes the crystallization mechanism and improves the stability of the fluoroaluminate glass.

The enhanced aerosol deposition by bipolar corona discharge arrays

The corona discharges provide an efficient way to induce precipitation or eliminate fog by increasing ion density in the open air.In this paper,one bipolar corona discharge array(positive and negative high voltage coupled simultaneously)which can generate high densities of positive and negative ions is developed.The comparison between bipolar corona discharge array and unipolar corona discharge array(positive or negative coupled only)indicates that bipolar corona discharge array can generate~3 times higher ion density than unipolar corona discharge array.More charged aerosols are produced through collisions between ions and aerosols.The collision rate between aerosols is increased substantially by the attractive forces between positively and negatively charged aerosols.The deposition of aerosols induced by bipolar discharges is 25.7%higher than that of unipolar discharges at the humidity super-saturation condition.Therefore,the bipolar corona discharge system is a new option for the large scale ion sources used for artificial weather modification.

腹部B超与阴道B超对异位妊娠的临床诊断价值比较

目的比较腹部B超、阴道B超对异位妊娠的临床诊断价值。方法选取2013年7月-2015年6月我院收治的异位妊娠患者70例,将其随机分为观察组与对照组,各35例。对照组患者采用腹部B超进行诊断,观察组采用阴道B超进行诊断,对比两组的诊断效果。结果观察组患者的诊断率为94.28%,显著高于对照组的74.29%(P<0.05)。结论阴道B超诊断异位妊娠的临床诊断价值显著,具有操作简单、受外界干扰少等诸多优点,在临床上值得广泛推广。

DNA damage-mediated cellular senescence promotes hand-foot syndrome that can be relieved by thymidine prodrug

Hand-foot syndrome(HFS)is a widely recognized dose-limiting cutaneous toxicity effect of fluoropyrimidine chemotherapy agents that impairs clinical benefits and treatment outcomes.Even though the cause and pathophysiology of HFS are relatively widely reported,how the toxicity of fluoropyrimidine translates into persistent inflammation has not been studied.Additionally,prevention and treatment strategies for HFS based on its mechanistic occurrence and development are scarce.In our study,we demonstrated that cGAS-STING signaling pathway-mediated cellular senescence played a critical role in the inflammatory reaction and provided a therapeutic solution for HFS.Mechanistically,DNA damage,as the primary cytotoxic cause,in keratinocytes induces cell cycle arrest,activates the cGAS-STING signaling pathway,and subsequently mediates cellular senescence,ultimately fueling a robust secondary inflammatory response that results in HFS.More importantly,the thymidine prodrug thymidine diacetate was proven to be effective in preventing HFS by compensating for thymidylate deficiency to facilitate the replication and repair of DNA and thus causing the escape from cellular senescence.These data highlight the importance of DNA damage-mediated cellular senescence in the etiology of HFS and provide a potential therapeutic anchor point for fluoropyrimidine-induced HFS.

Coupling of Epsilon-Near-Zero Mode to Mushroom-Type Metamaterial for Optimizing Infrared Suppression and Radiative Cooling

We report a complementary metal oxide semiconductor(CMOS)compatible metamaterial-based spectrally selective absorber/emitter(MBSSAE)for infrared(IR)stealth,which has the low absorption/emissivity in the IR atmospheric transmission window(3μm-5μm,8μm-14μm)and ultra-high and broadband absorption/emissivity in the IR non-atmospheric window(5μm-8μm).We propose a novel method for the broadband absorption/emissivity in 5μm-8μm with incorporation of an epsilon-near-zero(ENZ)material between the top patterned aluminum(Al)disks layer and the silicon oxide(SiO_(2))spacer layer.With an appropriate design,the peaks in the IR atmospheric transmission window can be suppressed while the peak intensity in the non-atmospheric window remains high.The optimized MBSSAE has an average absorption/emissivity less than 10%in 8μm-14μm and less than 6%in 3μm-5μm.And the average absorption/emissivity in 5μm-8μm is approximately over 64%.This proposed scheme may introduce the opportunities for the large-area and low-cost infrared stealth coating,as well as for the radiative cooling,spectral selective thermal detector,optical sensor,and thermophotovoltaic applications.

In-situ study of the hydrogen peroxide photoproduction in seawater on carbon dot-based metal-free catalyst under operation condition

Hydrogen peroxide(H_(2)O_(2))photoproduction in seawater with metal-free photocatalysts derived from biomass materials is a green,sustainable,and ultra environmentally friendly way.However,most photocatalysts are always corroded or poisoned in seawater,resulting in a significantly reduced catalytic performance.Here,we report the metal-free photocatalysts(RUT-1 to RUT-5)with in-situ generated carbon dots(CDs)from biomass materials(Rutin)by a simple microwave-assisted pyrolysis method.Under visible light(λ≥420 nm,81.6 mW/cm^(2)),the optimized catalyst of RUT-4 is stable and can achieve a high H_(2)O_(2)yield of 330.36μmol/L in seawater,1.78 times higher than that in normal water.New transient potential scanning(TPS)tests are developed and operated to in-situ study the H_(2)O_(2)photoproduction of RUT-4 under operation condition.RUT-4 has strong oxygen(O_(2))absorption capacity,and the O_(2)reduction rate in seawater is higher than that in water.Metal cations in seawater further promote the photo-charge separation and facilitate the photo-reduction reaction.For RUT-4,the conduction band level under operating conditions only satisfies the requirement of O_(2)reduction but not for hydrogen(H2)evolution.This work provides new insights for the in-situ study of photocatalyst under operation condition,and gives a green and sustainable path for the H_(2)O_(2)photoproduction with metal-free catalysts in seawater.

Direct reprogramming of fibroblasts into functional hepatocytes via CRISPRa activation of endogenous Gata4 and Foxa3

Background:The ability to generate functional hepatocytes without relying on donor liver organs holds significant therapeutic promise in the fields of regenerative medicine and potential liver disease treatments.Clustered regularly interspaced short palindromic repeats(CRISPR)activator(CRISPRa)is a powerful tool that can conveniently and efficiently activate the expression of multiple endogenous genes simultaneously,providing a new strategy for cell fate determination.The main purpose of this study is to explore the feasibility of applying CRISPRa for hepatocyte reprogramming and its application in the treatment of mouse liver fibrosis.Method:The differentiation of mouse embryonic fibroblasts(MEFs)into functional induced hepatocyte-like cells(iHeps)was achieved by utilizing the CRISPRa synergistic activation mediator(SAM)system,which drove the combined expression of three endogenous transcription factors-Gata4,Foxa3,and Hnf1a-or alternatively,the expression of two transcription factors,Gata4 and Foxa3.In vivo,we injected adeno-associated virus serotype 6(AAV6)carrying the CRISPRa SAM system into liver fibrotic Col1a1-Cre^(ER);Cas9^(fl/fl)mice,effectively activating the expression of endogenous Gata4 and Foxa3 in fibroblasts.The endogenous transcriptional activation of genes was confirmed using real-time quantitative polymerase chain reaction(RT-qPCR)and RNA-seq,and the morphology and characteristics of the induced hepatocytes were observed through microscopy.The level of hepatocyte reprogramming in vivo is detected by immunofluorescence staining,while the improvement of liver fibrosis is evaluated through Sirius red staining,alpha-smooth muscle actin(α-SMA)immunofluorescence staining,and blood alanine aminotransferase(ALT)examination.Results:Activation of only two factors,Gata4 and Foxa3,via CRISPRa was sufficient to successfully induce the transformation of MEFs into iHeps.These iHeps could be expanded in vitro and displayed functional characteristics similar to those of mature hepatocytes,such as drug metabolism and glycogen storage.Additionally,AAV6-based delivery of the CRISPRa SAM system effectively induced the hepatic reprogramming from fibroblasts in mice with live fibrosis.After 8 weeks of induction,the reprogrammed hepatocytes comprised 0.87%of the total hepatocyte population in the mice,significantly reducing liver fibrosis.Conclusion:CRISPRa-induced hepatocyte reprogramming may be a promising strategy for generating functional hepatocytes and treating liver fibrosis caused by hepatic diseases.

Analyzing the spatiotemporal evolution and driving forces of gross ecosystem product in the upper reaches of the Chaobai River Basin

The Chaobai River Basin,which is a crucial ecological barrier and primary water source area within the Beijing-Tianjin-Hebei region,possesses substantial ecological significance.The gross ecosystem product(GEP)in the Chaobai River Basin is a reflection of ecosystem conditions and quantifies nature’s contributions to humanity,which provides a basis for basin ecosystem service management and decision-making.This study investigated the spatiotemporal evolution of GEP in the upper Chaobai River Basin and explored the driving factors influencing GEP spatial differentiation.Ecosystem patterns from 2005 to 2020 were analyzed,and GEP was calculated for 2005,2010,2015,and 2020.The driving factors influencing GEP spatial differentiation were identified using the optimal parameter-based geographical detector(OPGD)model.The key findings are as follows:(1)From 2005 to 2020,the main ecosystem types were forest,grassland,and agriculture.Urban areas experienced significant changes,and conversions mainly occurred among urban,water,grassland and agricultural ecosystems.(2)Temporally,the GEP in the basin increased from 2005 to 2020,with regulation services dominating.At the county(district)scale,GEP exhibited a north-west-high and south-east-low pattern,showing spatial differences between per-unit-area GEP and county(district)GEP,while the spatial variations in per capita GEP and county(district)GEP were similar.(3)Differences in the spatial distribution of GEP were influenced by regional natural geographical and socioeconomic factors.Among these factors,gross domestic product,population density,and land-use degree density contributed significantly.Interactions among different driving forces noticeably impacted GEP spatial differentiation.These findings underscore the necessity of incorporating factors such as population density and the intensity of land-use development into ecosystem management decision-making processes in the upper reaches of the Chaobai River Basin.Future policies should be devised to regulate human activities,thereby ensuring the stability and enhancement of GEP.

Novel high-safety aeroengine performance predictive control method based on adaptive tracking weight

Increasing attention has been attracted to the dynamic performance and safety of advanced performance predictive control systems of the next-generation aeroengine.The latest research demonstrates that Subspace-based Improved Model Predictive Control(SIMPC)can overcome the difficulty in solving the predictive model in MPC/NMPC applications.However,applying constant design parameters cannot maintain consistent control effects in all states.Meanwhile,the designed system relies too much on sensor-measured data,and thus it is difficult to thoroughly validate the safety of the system because of its high complexity.This means that any potential hardware/software faults will endanger the engine.Therefore,this paper first presents a novel nonlinear mapping relationship to adaptively tune the tracking weight online with the change of Power Lever Angle(PLA)and real-time relative tracking error.Thus,without introducing additional design parameters,an Adaptive Tracking Weight-based SIMPC(ATW-SIMPC)controller is designed to improve the control performance in all operating states effectively.Then,a Primary/Backup Hybrid Control(PBHC)strategy with the ATW-SIMPC controller as the primary system and the traditional speed(Nf)controller as the backup system is proposed to ensure safety.The designed affiliated switching controller and the real-time monitor therein can be used to realize reasonable and smooth switching between primary/backup systems,so as to avoid bump transition.The PBHC system switches to the Nf controller when the ATW-SIMPC controller is wrong because of potential hardware/software faults;otherwise,the ATW-SIMPC controller keeps acting on the engine.The main results prove that the ATW-SIMPC controller with the optimal nonlinear mapping relationship,compared with the existing SIMPC controller,uplifts the dynamic control performance by 32%and reduces overshoots to an allowable limit,resulting in a better control effect in full state.The comparison results consistently indicate that the PBHC can guarantee engine safety in occurrence of hardware/software faults,such as sensor/onboard adaptive model faults.The approach proposed is applicable to the design of a model-based engine intelligent control system.

Effect of an eco-friendly o/w emulsion stabilized with amphiphilic sodium alginate derivatives on lambda-cyhalothrin adsorption-desorption on natural soil minerals

The effects of amphiphilic O/W emulsions,stabilized by the alkyl polyglycoside(APG)or cholesterol-grafted sodium alginate(CSAD)/APG systems,on lambda-cyhalothrin adsorption/desorption mechanisms on natural soil minerals(i.e.,illite and kaolinite)were investigated.Sorption and desorption of lambda-cyhalothrin onto soil minerals was studied via batch equilibration to give insight into the adsorption equilibrium,kinetics,and thermodynamics of lambda-cyhalothrin adsorption onto minerals.The results indicate the following:(i)The adsorption processes for the APG system and CSAD/APG system include:rapid adsorption,slow adsorption,and adsorption equilibrium.The adsorption kinetics of pesticide on illite and kaolinite are in accordance with the Ho and McKay model,and the adsorption isotherm conforms to the Freundlich model.In addition,the adsorption processes of pesticide for the two systems on minerals were spontaneous and feasible(ΔG^0<0),endothermic(ΔH^0>0),and mainly involved chemical bonding(ΔH^0>60).(ii)The equilibrium adsorption percentages of the pesticide on illite for the APG system and CSAD/APG system were 42.4%and 64.8%,and the corresponding equilibrium adsorption percentages on kaolinite were 40.8%and 61.8%,respectively.Moreover,the pesticide adsorption rate K_(2-CSAD/APG)was faster than K_(2-APG),and its adsorption capacity K_(f-CSAD/APG )was greater than K_(f-APG).Meanwhile,the pesticide desorption K_(fd)in the CSAD/APG system was smaller than that in the APG system.As a result,this eco-friendly O/W emulsion based on amphiphilic sodium alginate derivatives might provide a green pesticide formulation,since it could reduce the amount of lambda-cyhalothrin entering aquatic systems to threaten non-target fish and invertebrate species.

Application of next-generation sequencing to screen for pathogenic mutations in 123 unrelated Chinese patients with Marfan syndrome or a related disease

Marfan syndrome(MFS) is a systemic connective tissue disease principally affecting the ocular, skeletal and cardiovascular systems. This autosomal dominant disorder carries a prevalence of 1:3,000 to 1:5,000. This study aims to define the mutational spectrum of MFS related genes in Chinese patients and to establish genotype-phenotype correlations in MFS. Panel-based targeted next-generation sequencing was used to analyze the FBN1, TGFBR1 and TGFBR2 genes in 123 unrelated Chinese individuals with MFS or a related disease. Genotype-phenotype correlation analyses were performed in mutation-positive patients. The results showed that 97 cases/families(78.9%;97/123) harbor at least one(likely) pathogenic mutation, most of which were in FBN1;four patients had TGFBR1/2 mutations;and one patient harbored a SMAD3 mutation. Three patients had two FBN1 mutations, and all patients showed classical MFS phenotypes. Patients with a dominant negative-FBN1 mutation had a higher prevalence of ectopia lentis(EL). Patients carrying a haploinsufficiency-FBN1 mutation tended to have aortic dissection without EL. This study extends the spectrum of genetic backgrounds of MFS and enriches our knowledge of genotype-phenotype correlations.

Nanoscale engineering of conducting polymers for emerging applications in soft electronics

Soft electronics featuring exceptional mechanical compliance and excellent electrical performance hold great promise for applications in soft robotics,artificial intelligence,bio-integrated electronics,and wearable electronics.Intrinsically stretchable and conductive materials are crucial for soft electronics,enabling large-area and scalable fabrication,high device density,and good mechanical compliance.Conducting polymers are inherently stretchable and conductive.They can be precisely synthesized from vastly available building blocks,and thus they provide a fruitful platform for fabricating soft electronics.However,amorphous bulk-phase conducting polymers typically exhibit poor mechanical and electrical characteristics.Consequently,it is highly desirable to develop novel engineering approaches to overcome the intrinsic limitations of conducting polymers.In recent years,numerous engineering strategies have been developed to enhance their performances in soft electronic devices via constructing various nanostructures.In this review,we first summarize several unique methodologies to fabricate conducting polymer-based nanostructures.We then discuss how nanoscale engineering approaches can improve several crucial parameters,including electrical conductivity,stretchability,sensitivity,and self-healing property of conducting polymers.Moreover,we also discuss device-level integration of conducting polymer-based nanostructures with other materials for applications in skin-inspired electronics and bio-integrated electronics.Finally,we provide perspectives on challenges and future directions in engineering nanostructured conducting polymers for soft electronics.

Enhancing soil aggregation and acetamiprid adsorption by ecofriendly polysaccharides hydrogel based on Ca^(2+)-amphiphilic sodium alginate

Soil aggregation plays an important role in agricultural production activities.However,the structure of soil aggregation is destroyed by the natural environment and unreasonable farming management,resulting in the loss of water,fertilizers and pesticides in soil.At present,hydrogels have been widely reported to promote the formation of soil aggregation.In this paper,amphiphilic calcium alginate(ASA/Ca^(2+))was applied to promote the formation of soil aggregation and enhance pesticide retention.Initially,an ASA was obtained through the one-pot Ugi condensation(a four-component green chemical reaction).Then,ASA/Ca^(2+) hydrogel is prepared by Ca^(2+) cross-linking.The formation of soil aggregation was determined through the Turbiscan Lab Expert stability analyzer,Confocal Laser Scanning Microscope(CLSM),and Transmission Electron Microscope(TEM).And the effect of soil aggregation on acetamiprid environmental behavior was investigated by adsorption kinetics,adsorption isotherms,and leaching.The results shown that the three-dimensional network structure of ASA/Ca^(2+) hydrogel can promote the formation of soil aggregation.Aggregate durability index(ADI)was 0.55 in the presence of ASA/Ca^(2+) hydrogel,indicating that amphiphilic hydrogel can enhance the stability of soil aggregation.The adsorbing capacity of acetamiprid was 1.58 times higher than pure soil,and the release of acetamiprid only about 20%in the presence of ASA/Ca^(2+) hydrogel.These results would be helpful for the formation of soil aggregation and pesticides adsorption on soil aggregation.Thus,ASA/Ca^(2+) hydrogel is likely to improve soil quality,simultaneously it can minimize the mobility of pesticides in the agricultural system.

Expeditious and scalable preparation of a Li-Thiele reagent for amine-based bioconjugation

Chemoselective amine bioco njugation has long been a challenge for native protein modification.Inspired by Thiele’s seminal discovery,Li and co-workers recently developed an orto-phthalaldehyde(OPA)based reagent for labeling the amino group of a protein.Here we report an expeditious and scalable synthesis of a Li-Thiele reagent featuring an arene construction strategy.The reagent contains an alkyne side chain as a handle for secondary modification.

Synthesis of a glucose conjugate of pristimerin and evaluation of its anticancer activity

Taking advantage of the Warburg effect in cancer cells, glucose conjugation has emerged as a useful strategy for targeted delivery of anticancer agents. Pristimerin is a naturally occurring triterpenoid that displays potent but non-selective cytotoxicity. We developed a convergent and modular approach to construction of glucose-payload conjugates featuring copper-mediated azide-alkyne cycloaddition and prepared a glucose conjugate of pristimerin through this approach. The anticancer activity of this conjugate was evaluated in cancer cells and normal cells;however, the selectivity toward cancer cells was not significantly improved. We then examined the extracellular stability of the conjugate and found that its ester linkage was cleaved rapidly in Dulbecco’s Modified Eagle’s Medium at 37 °C, which resulted in the release of pristimerin. In fact, the inorganic components in this medium were sufficient to induce the cleavage.Given that the subtle difference between intrinsic stability and extracellular stability of the conjugate linker is often underappreciated, this work highlights the importance of the latter in the development of target-selective conjugates.

Contactless interaction recognition and interactor detection in multi-person scenes

Human interaction recognition is an essential task in video surveillance.The current works on human interaction recognition mainly focus on the scenarios only containing the close-contact interactive subjects without other people.In this paper,we handle more practical but more challenging scenarios where interactive subjects are contactless and other subjects not involved in the interactions of interest are also present in the scene.To address this problem,we propose an Interactive Relation Embedding Network(IRE-Net)to simultaneously identify the subjects involved in the interaction and recognize their interaction category.As a new problem,we also build a new dataset with annotations and metrics for performance evaluation.Experimental results on this datasesthow significant improvements of the proposed method when compared with current methodsdeveloped for human interaction recognition and group activity recognition.