Observations and modelling of the travel time delay and leading negative phase of the 16 September 2015 Illapel,Chile tsunami

The systematic discrepancies in both tsunami arrival time and leading negative phase(LNP)were identified for the recent transoceanic tsunami on 16 September 2015 in Illapel,Chile by examining the wave characteristics from the tsunami records at 21 Deep-ocean Assessment and Reporting of Tsunami(DART)sites and 29 coastal tide gauge stations.The results revealed systematic travel time delay of as much as 22 min(approximately 1.7%of the total travel time)relative to the simulated long waves from the 2015 Chilean tsunami.The delay discrepancy was found to increase with travel time.It was difficult to identify the LNP from the near-shore observation system due to the strong background noise,but the initial negative phase feature became more obvious as the tsunami propagated away from the source area in the deep ocean.We determined that the LNP for the Chilean tsunami had an average duration of 33 min,which was close to the dominant period of the tsunami source.Most of the amplitude ratios to the first elevation phase were approximately 40%,with the largest equivalent to the first positive phase amplitude.We performed numerical analyses by applying the corrected long wave model,which accounted for the effects of seawater density stratification due to compressibility,self-attraction and loading(SAL)of the earth,and wave dispersion compared with observed tsunami waveforms.We attempted to accurately calculate the arrival time and LNP,and to understand how much of a role the physical mechanism played in the discrepancies for the moderate transoceanic tsunami event.The mainly focus of the study is to quantitatively evaluate the contribution of each secondary physical effect to the systematic discrepancies using the corrected shallow water model.Taking all of these effects into consideration,our results demonstrated good agreement between the observed and simulated waveforms.We can conclude that the corrected shallow water model can reduce the tsunami propagation speed and reproduce the LNP,which is observed for tsunamis that have propagated over long distances frequently.The travel time delay between the observed and corrected simulated waveforms is reduced to<8 min and the amplitude discrepancy between them was also markedly diminished.The incorporated effects amounted to approximately 78%of the travel time delay correction,with seawater density stratification,SAL,and Boussinesq dispersion contributing approximately 39%,21%,and 18%,respectively.The simulated results showed that the elastic loading and Boussinesq dispersion not only affected travel time but also changed the simulated waveforms for this event.In contrast,the seawater stratification only reduced the tsunami speed,whereas the earth’s elasticity loading was responsible for LNP due to the depression of the seafloor surrounding additional tsunami loading at far-field stations.This study revealed that the traditional shallow water model has inherent defects in estimating tsunami arrival,and the leading negative phase of a tsunami is a typical recognizable feature of a moderately strong transoceanic tsunami.These results also support previous theory and can help to explain the observed discrepancies.

Squeezing More Past Knowledge for Online Class-Incremental Continual Learning

Continual learning(CL)studies the problem of learning to accumulate knowledge over time from a stream of data.A crucial challenge is that neural networks suffer from performance degradation on previously seen data,known as catastrophic forgetting,due to allowing parameter sharing.In this work,we consider a more practical online class-incremental CL setting,where the model learns new samples in an online manner and may continuously experience new classes.Moreover,prior knowledge is unavailable during training and evaluation.Existing works usually explore sample usages from a single dimension,which ignores a lot of valuable supervisory information.To better tackle the setting,we propose a novel replay-based CL method,which leverages multi-level representations produced by the intermediate process of training samples for replay and strengthens supervision to consolidate previous knowledge.Specifically,besides the previous raw samples,we store the corresponding logits and features in the memory.Furthermore,to imitate the prediction of the past model,we construct extra constraints by leveraging multi-level information stored in the memory.With the same number of samples for replay,our method can use more past knowledge to prevent interference.We conduct extensive evaluations on several popular CL datasets,and experiments show that our method consistently outperforms state-of-the-art methods with various sizes of episodic memory.We further provide a detailed analysis of these results and demonstrate that our method is more viable in practical scenarios.

Water-responsive gel extends drug retention and facilitates skin penetration for curcumin topical delivery against psoriasis

Psoriasis is a chronic inflammatory skin disease characterized by erythema,scaling,and skin thickening.Topical drug application is recommended as the first-line treatment.Many formulation strategies have been developed and explored for enhanced topical psoriasis treatment.However,these preparations usually have low viscosity and limited retention on the skin surface,resulting in low drug delivery efficiency and poor patient satisfaction.In this study,we developed the first water-responsive gel(WRG),which has a distinct water-triggered liquid-to-gel phase transition property.Specifically,WRG was kept in a solution state in the absence of water,and the addition of water induced an immediate phase transition and resulted in a high viscosity gel.Curcumin was used as a model drug to investigate the potential of WRG in topical drug delivery against psoriasis.In vitro and in vivo data showed that WRG formulation could not only extend skin retention but also facilitate the drug permeating across the skin.In a mouse model of psoriasis,curcumin loaded WRG(CUR-WRG)effectively ameliorated the symptoms of psoriasis and exerted a potent anti-psoriasis effect by extending drug retention and facilitating drug penetration.Further mechanism study demonstrated that the anti-hyperplasia,anti-inflammation,anti-angiogenesis,anti-oxidation,and immunomodulation properties of curcumin were amplified by enhanced topical drug delivery efficiency.Notably,neglectable local or systemic toxicity was observed for CUR-WRG application.This study suggests that WRG is a promising formulation for topically psoriasis treatment.

Key Problems in Microforming Processes of Microparts

From the viewpoint of production engineering, microforming is considered as an effective process to fabricate various microparts. Several key problems in microforming processes were investigated. A new microforming apparatus with a high stiffness piezoelectric actuator as the punch driver was developed to produce microparts.To improve the forming abilities and locate the billets, a floating microdie was designed. The size effects of the billets and die cavities on the microforming abilities were studied with upsetting and coining tests, respectively.And the isothermal microforming process of microgears was performed with the developed microforming apparatus. Several analysis methods were used to evaluate the forming quality of the microparts.

Alantolactone-loaded chitosan/hyaluronic acid nanoparticles suppress psoriasis by deactivating STAT3 pathway and restricting immune cell recruitment

Psoriasis is a common chronic immune-mediated skin disease characterized by hyperproliferation and aberrant differentiation of keratinocytes and massive infiltration of inflammatory immune cells.Recent studies showed that Signal Transducer and Activator of Transcription 3(STAT3),which plays an important role in cell survival,proliferation,differentiation,angiogenesis,and immune responses,is constitutively activated in epidermal keratinocytes of human psoriatic skin lesions.In addition,STAT3 promotes the differentiation and expansion of T cells and facilitates cytokine production,thereby exacerbating the condition of psoriasis.Alantolactone(ALT)is a sesquiterpene lactone compound that could selectively suppress STAT3 activation,but its effectiveness and application in psoriasis treatment have not been determined.In this study,we developed ALT loaded chitosan/hyaluronic acid nanoparticles(CHALT),and investigated its therapeutic potential for psoriasis therapy.CHALT effectively abrogated the hyperproliferation by inducing ROS-mediated apoptosis with loss of mitochondrialmembrane potential,and also inhibited IL-6-induced STAT3 signaling activation and inflammatory reaction in HaCaT cell line.In an Imiquimod(IMQ)-induced psoriasis model,the topical treatment of psoriasis lesions with CHALT effectively attenuated the STAT3 hyperactivation within keratinocytes and ameliorated the symptoms of psoriasis.In addition,it was found that CHALT restricted the recruitment of immune cells.These results indicated that ALT-based nanoformulation CHALT holds great potential for psoriasis therapy.

How did the Tonga volcanic tsunami on January 15,2022,affect Chinese coasts?

At 12:15 on January 15,2022(Beijing time),a massive eruption of the Hunga Tonga-Hunga Ha'apai volcano produced violent atmospheric fluctuations,which in turn generated a global tsunami through an abrupt air pressure shock upon the sea surface.Two main components of tsunami waves,phase-locked waves and free gravity waves,were identified by significant differences in propagating speeds across the deep ocean.The phase-locked wave propagated through the ocean basin synchronously with the atmospheric Lamb wave at an average speed of approximately 306 m/s,followed by the free gravity wave at a slower speed.The locked wave reached the coast of eastern Taiwan Island at about 20:00 on January 15,in coincidence with the Lamb wave arrival.However,on the coast of Chinese mainland,tidal gauges did not record tsunami signals until at least 2 h after the Lamb wave arrivals.Theoretical analyses and numerical experiments both suggested that as a result of the incoming wave shoaling above the vast continental shelf of Chinese mainland,the locked wave was no longer trapped by the air pressure shock and gradually transformed into freely-propagating shallow water waves by slowing down its propagation.Due to the longlasting planetary atmospheric fluctuations circling the earth many times,the sea level oscillations continuously propagated onto the Chinese shelf,which resulted in the tsunami waves excited along the Chinese coasts for at least 36 h.The maximum wave amplitude recorded on the coast of eastern Taiwan Island was 44 cm at Wushi,while on the coasts of eastern and southern Chinese mainland,the maximum amplitudes were 22 cm at Shipu and 13 cm at Zhuhai.Fourier and wavelet analyses were performed to identify the major components of the tsunami waves on the Chinese coasts.The results indicated that eastern Taiwan Island was impacted mainly by the waves with periods of approximately 10-40 min.Chinese mainland was hit by the evolved shallow water waves and subsequent free waves,with periods of approximately 40-100 and 16-20 min,respectively.

Exploring luminescence quenching on lanthanide-doped nanoparticles through changing the spatial distribution of sensitizer and activator

Luminescence quench is common in overdoped upconversion nanoparticles.Various methods have been proposed to counteract the adverse effects of concentration quenching on luminescence,but in upconversion nanoparticles that are highly doped with both sensitizers and activators,the factors that contribute to the diminishing of the emission cannot be summarized by a single cause.Herein,a core-shell design is used to spatially separate the sensitizer(Yb^(3+))and activator(Er^(3+))and to modulate the emission by changes in the distribution position as well as the concentration of the dopant ions in order to probe the factors affecting the luminescence.When the sensitizer ions are located in the core,the luminescence intensity of the nanoparticles is significantly weaker than that of the other distribution,which implies that the effect of sensitizer and activator on luminescence in the highly doped state has a different and more complex mechanism.The intensity of the emission is more affected by Yb^(3+)than Er^(3+),which includes not only the self-quenching of Yb^(3+),but also the dominance in the Yb^(3+)-Er^(3+)cross-relaxation.In this finding may provide new ideas for revealing the reasons for the diminished luminescence of highly doped upconversion nanoparticles and thus for enhancing luminescence.

Reinforcement Learning Navigation for Robots Based on Hippocampus Episode Cognition

Artificial intelligence is currently achieving impressive success in all fields.However,autonomous navigation remains a major challenge for AI.Reinforcement learning is used for target navigation to simulate the interaction between the brain and the environment at the behavioral level,but the Artificial Neural Network trained by reinforcement learning cannot match the autonomous mobility of humans and animals.The hippocampus–striatum circuits are considered as key circuits for target navigation planning and decision-making.This paper aims to construct a bionic navigation model of reinforcement learning corresponding to the nervous system to improve the autonomous navigation performance of the robot.The ventral striatum is considered to be the behavioral evaluation region,and the hippocampal–striatum circuit constitutes the position–reward association.In this paper,a set of episode cognition and reinforcement learning system simulating the mechanism of hippocampus and ventral striatum is constructed,which is used to provide target guidance for the robot to perform autonomous tasks.Compared with traditional methods,this system reflects the high efficiency of learning and better Environmental Adaptability.Our research is an exploration of the intersection and fusion of artificial intelligence and neuroscience,which is conducive to the development of artificial intelligence and the understanding of the nervous system.

玉屏风散治疗慢性肾小球肾炎的临床疗效评价及作用机制研究

本研究通过meta分析评价玉屏风散(YPF)治疗慢性肾小球肾炎(CGN)的临床疗效,并利用网络药理学和分子对接探讨其作用机制。检索国内外数据库CNKI、维普、中国生物医学、万方、PubMed和Cochrane建库至2023年5月YPF治疗CGN临床随机对照试验,根据纳入和排除标准,纳入研究。运用RevMan5.4软件进行质量评估和meta分析,使用TSABeta软件对主要结局指标进行序贯分析。通过TCMSP、GeneC ards、OMIM、TTD数据库检索YPF的有效成分及CGN靶点,利用Venny2.1.0获取两者交集靶点,运用DAVID数据库进行GO和KEGG富集分析。通过AutoDockVina1.5.6软件进行分子对接。共纳入14项研究,1072名患者。meta分析结果显示,YPF在治疗CGN的临床总有效率[OR=6.99,95%CI(4.68,10.44)],证候改善率[OR=3.16,95%CI(1.43,6.98)],降低24小时尿蛋白[SMD=–1.90,95%CI(–2.54,–1.25)]、血清肌酐[SMD=–0.38,95%CI(–0.57,–0.19)],尿素氮[SMD=–0.46,95%CI(–0.63,–0.30)],均具有统计学意义(P<0.05)。序贯分析结果表明,本次meta结果是可靠的,YPF治疗CGN的总有效率优于单纯西药治疗。网络药理学共筛选出槲皮素、山奈酚、汉黄芩素等45种有效成分,关键靶点有TNF、AKT1、IL-6和VEGF等,涉及AGE-RAGE、TNF、PI3K-AKT等信号通路。分子对接显示,槲皮素、山奈酚、汉黄芩素等与关键靶点可稳定结合,结合能均≤–6.0 kJ/mol。结果发现,YPF对CGN是一种积极的治疗措施,其作用机制可能与多种成分、多个靶点、多条信号通路产生的免疫调节、抗炎、抗氧化和抗纤维化有关。

Robot Navigation Strategy in Complex Environment Based on Episode Cognition

The hippocampal formation of the brain contains a series of nerve cells related to environmental cognition and navigation.These cells can integrate their moment information and external perceptual information and acquire episodic cognitive memory.Through episodic cognition and memory,organisms can achieve autonomous navigation in complex environments.This paper mainly studies the strategy of robot episode navigation in complex environments.After exploring the environment,the robot obtains subjective environmental cognition and forms a cognition map.The grid cells information contained in the cognitive map can obtain the direction and distance of the target through vector calculation,which can get a shortcut through the inexperienced area.The synaptic connection of place cells in the cognitive map can be used as the topological relationship between episode nodes.When the target-oriented vector navigation encounters obstacles,the obstacles can be realized by setting closer sub-targets.Based on the known obstacle information obtained from boundary cells in the cognitive map,topological paths can be divided into multi-segment vector navigation to avoid encountering obstacles.This paper combines vector and topological navigation to achieve goal-oriented and robust navigation capability in a complex environment.

Control of a Quadruped Robot with Bionic Springy Legs in Trotting Gait

Legged robots have better performance on discontinuous terrain than that of wheeled robots. However, the dynamic trotting and balance control of a quadruped robot is still a challenging problem, especially when the robot has multi-joint legs. This paper presents a three-dimensional model of a quadruped robot which has 6 Degrees of Freedom （DOF） on torso and 5 DOF on each leg. On the basis of the Spring-Loaded Inverted Pendulum （SLIP） model, body control algorithm is discussed in the first place to figure out how legs work in 3D trotting. Then, motivated by the principle of joint function separation and introducing certain biological characteristics, two joint coordination approaches are developed to produce the trot and provide balance. The robot reaches the highest speed of 2.0 m.s-1, and keeps balance under 250 Kg.m.s-1 lateral disturbance in the simulations. The effectiveness of these approaches is also verified on a prototype robot which runs to 0.83 m.s-1 on the treadmill, The simulations and experiments show that legged robots have good biological properties, such as the ground reaction force, and spring-like leg behavior.

Bio-Inspired Controller for a Robot Cheetah with a Neural Mechanism Controlling Leg Muscles

The realization of a high-speed running robot is one of the most challenging problems in developing legged robots. The excellent performance of cheetahs provides inspiration for the control and mechanical design of such robots. This paper presents a three-dimensional model of a cheetah that predicts the locomotory behaviors of a running cheetah. Applying biological knowledge of the neural mechanism, we control the muscle flexion and extension during the stance phase, and control the positions of the joints in the flight phase via a PD controller to minimize complexity. The proposed control strategy is shown to achieve similar locomotion of a real cheetah. The simulation realizes good biological properties, such as the leg retraction, ground reaction force, and spring-like leg behavior. The stable bounding results show the promise of the controller in high-speed locomotion. The model can reach 2.7 m-s^-1 as the highest speed, and can accelerate from 0 to 1.5 m-s^-1 in one stride cycle. A mechanical structure based on this simulation is designed to demonstrate the control approach, and the most recently developed hindlimb controlled by the proposed controller is presented in swinging-leg experiments and jump-force experiments.

CPG Control for Biped Hopping Robot in Unpredictable Environment

A CPG control mechanism is proposed for hopping motion control of biped robot in unpredictable environment. Based on analysis of robot motion and biological observation of animal＇s control mechanism, the motion control task is divided into two simple parts： motion sequence control and output force control. Inspired by a two-level CPG model, a two-level CPG control mechanism is constructed to coordinate the drivers of robot joint, while various feedback information are introduced into the control mechanism. Interneurons within the control mechanism are modeled to generate motion rhythm and pattern promptly for motion sequence control; motoneurons are modeled to control output forces of joint drivers in real time according to feedbacks. The control system can perceive changes caused by unknown perturbations and environment changes according to feedback information, and adapt to unpredictable environment by adjusting outputs of neurons. The control mechanism is applied to a biped hopping robot in unpredictable environment on simulation platform, and stable adaptive motions are obtained.

Recent progress of energy transfer and luminescence intensity boosting mechanism in Nd3+-sensitized upconversion nanoparticles

Rare earth doped upconversion nanoparticles can be considered as the spice of research in the field of luminescence nanomaterials due to their unique optical properties such as near-infrared excitation.Enormous works have been reported about biomedical applications of 980 nm excited and Yb^3+-sensitized upconversion nanoparticles.However,980 nm excitation wavelength overlaps with the absorption band of water molecules in the biological environment,leading to overheating effect that can induce thermal damages of normal cells and tissues.Recently,Nd^3+-sensitized upconversion nanoparticles which can be excited with 808 nm has been widely investigated as alternative nanoparticles that can surmount this issue of overheating effect.Even though Nd^3+-sensitized upconversion nanoparticles can reduce the overheating effect by 20 fold as compared to Yb^3+-sensitized counterpart,there are several factors that reduce the upconversion luminescence intensity.In this review article,photon energy harvesting and transferring mechanisms in Nd^3+,Yb^3+and emitter ions co-doped upconversion nanoparticles under 808 nm excitation are briefly discussed.Factors that affect upconversion luminescence intensity and quantum yield of Nd^3+-sensitized upconversion nanoparticles are also addressed.Besides,some of the important strategies that have been recently utilized to boost upconversion luminescence intensity of Nd^3+sensitized upco nversion nanoparticles are tho roughly summarized.Lastly,the future challenges in the area and our perspectives are in sight.

Facile synthesis of Er^(3+)/Tm^(3+)co-doped magnetic/luminescent nanosystems for possible bioimaging and therapy applications

Manganese-zinc ferrite is a kind of very important magnetic ferrite material.The properties of wide absorption band,sensitivity to ultraviolet(UV)light and tumor H_(2)O_(2) promise it to be possibly used as a photothermal therapy(PTT),photodynamic therapy(PDT)and chemodynamic therapy(CDT)agent.Based on the unique advantages of rare-earth doped nanoparticles,an Er^(3+),Tm^(3+)co-doped upconversion-mediated nanosystem with manganese-zinc ferrite shell(named as UCNPS@M)was developed through a facile thermal co-decomposition method.The final nanosystems were surface-modified by using dopamine hydrochloride(DA)in order to warrant good biocompatibility(named as UCNPS@M@DA).Under irradiation of near-infrared(NIR)light,UCNPS emit both ultraviolet and visible light.The UV light is mostly abso rbed by manga nese-zinc ferrite shell to produce reactive oxygen species(ROS),which is essential to the potential PDT and CDT effect of nanosystems,and at the same time,Mn_(0.5)Zn_(0.5)Fe2O_(4) can further react with H_(2)O_(2) to promote the efficiency of OH-generation.It is expected that UCNPS@M@DA can act as upconversion luminescence imaging guidance due to the visible emission from UCNPS.In addition,the energy absorbed by the nanosystems can be transferred to heat to realize photothermal effect.Moreover,UCNPS@M@DA was successfully applied as a T_(1)/T_(2)-weighted magnetic resonance imaging(MRI)contrast agent due to the existence of Gd,Mn,and Fe elements.In light of the upconversion luminescence(UCL)imaging from the UCNPS as well as potential PTT,PDT,CDT effect mentioned above,this work provides a possibility to realize cancer multi-model bioimaging guided treatment by using an all-in-one diagnosis and therapy nanosystem through a simple yet powerful strategy.

An epidermal sEMG tattoo-like patch as a new human–machine interface for patients with loss of voice

Throat cancer treatment involves surgical removal of the tumor,leaving patients with facial disfigurement as well as temporary or permanent loss of voice.Surface electromyography(sEMG)generated from the jaw contains lots of voice information.However,it is difficult to record because of not only the weakness of the signals but also the steep skin curvature.This paper demonstrates the design of an imperceptible,flexible epidermal sEMG tattoo-like patch with the thickness of less than 10μm and peeling strength of larger than 1N cm−1 that exhibits large adhesiveness to complex biological surfaces and is thus capable of sEMG recording for silent speech recognition.When a tester speaks silently,the patch shows excellent performance in recording the sEMG signals from three muscle channels and recognizing those frequently used instructions with high accuracy by using the wavelet decomposition and pattern recognization.The average accuracy of action instructions can reach up to 89.04%,and the average accuracy of emotion instructions is as high as 92.33%.To demonstrate the functionality of tattoo-like patches as a new human–machine interface(HMI)for patients with loss of voice,the intelligent silent speech recognition,voice synthesis,and virtual interaction have been implemented,which are of great importance in helping these patients communicate with people and make life more enjoyable.

Velocity Control of a Bounding Quadruped via Energy Control and Vestibular Reflexes

In this paper a bio-inspired approach of velocity control for a quadruped robot running with a bounding gait on compliant legs is set up. The dynamic properties ofa sagittal plane model of the robot are investigated. By analyzing the stable fixed points based on Poincare map, we find that the energy change of the system is the main source for forward velocity adjustment. Based on the analysis of the dynamics model of the robot, a new simple linear running controller is proposed using the energy control idea, which requires minimal task level feedback and only controls both the leg torque and ending impact angle. On the other hand, the functions of mammalian vestibular reflexes are discussed, and a reflex map between forward velocity and the pitch movement is built through statistical regression analysis. Finally, a velocity controller based on energy control and vestibular reflexes is built, which has the same structure as the mammalian nervous mechanism for body posture control. The new con- troller allows the robot to run autonomously without any other auxiliary equipment and exhibits good speed adjustment capa- bility. A series simulations and experiments were set to show the good movement agility, and the feasibility and validity of the robot system.

Lanthanide-doped heterostructured nanocomposites toward advanced optical anti-counterfeiting and information storage

The continuously growing importance of information storage,transmission,and authentication impose many new demands and challenges for modern nano-photonic materials and information storage technologies,both in security and storage capacity.Recently,luminescent lanthanide-doped nanomaterials have drawn much attention in this field because of their photostability,multimodal/multicolor/narrowband emissions,and long luminescence lifetime.Here,we report a multimodal nanocomposite composed of lanthanide-doped upconverting nanoparticle and EuSe semiconductor,which was constructed by utilizing a cation exchange strategy.The nanocomposite can emit blue and white light under 365 and 394 nm excitation,respectively.Meanwhile,the nanocomposites show different colors under 980 nm laser excitation when the content of Tb3+ions is changed in the upconversion nanoparticles.Moreover,the time-gating technology is used to filter the upconversion emission of a long lifetime from Tb3+or Eu3+,and the possibilities for modulating the emission color of the nanocomposites are further expanded.Based on the advantage of multiple tunable luminescence,the nanocomposites are designed as optical modules to load optical information.This work enables multi-dimensional storage of information and provides new insights into the design and fabrication of next-generation storage materials.

Nd^(3+)-sensitized upconversion nanoparticle coated with antimony shell for bioimaging and photothermal therapy in vitro using single laser irradiation

Combining treatment and diagnosis,called theranostics,which is achieved within single nanoparticle is an ultimate goal of many studies.Herein,we developed a new nanotheranostic agent-Nd^(3+)-sensitized upconversion nanoparticles core for dual modal imaging(i.e.,upconversion luminescence imaging and magnetic resonance imaging) and antimony nanoshell for photothermal therapy(PTT).The core-shellshell upconversion nanoparticles(NaYF_(4):Yb,Er@NaYF_(4):Yb,Nd@NaGdF_(4):Nd,named as UCNP) were firstly synthesized using thermal decomposition method and then were coated by antimony shell over the surface of UCNP using simple cost and time effective new method.Furthermore,the surface of UCNP@Sb nanostructures was modified with DSPE-PEG in order to enhance the water solubility and biocompatibility.The final nanotheranostic agent,named as UCNP@Sb-PEG,exhibits very low toxicity,good biocompatibility,very good photothermal therapeutic effect,and efficient upconversion luminescence(UCL) imaging of HeLa cells under only one laser(808 nm) irradiation.The antimony shell is quenching the upconversion emission in pristine nanotheranostic agent,but interestingly,the UCL intensity of the agent recovers progressively under 808 nm laser irradiation due to light induced degradability of antimony shell.Besides,high longitudinal relaxivity(r_(1)) obtained from the experiment approves excellent potential of the nanotheranostic agent for T_(1)-weighted magnetic resonance imaging application.

Lanthanide complexes-functionalized ordered mesoporous TiO_2:Multicolor emission(visible and near-infrared luminescence) based on visible-light sensitization

Recently,much attention has been paid to the lanthanide luminescent materials based on the visiblelight sensitization for their potential applications in the fields of bio-imaging and optical devices.In this work,the lanthanide complexes have been covalently bonded to the ordered mesoporous titania（OMT） matrix,and the resulting titania-based hybrid ordered mesoporous materials（named as LnDBOMT,Ln = Eu,Sm,Yb,Nd） were characterized by using Fourier-transform infrared（FT-IR） spectroscopy,small-angle X-ray powder diffraction（SAXD）,N2 adsorption-desorption isotherms,transmission electron microscopy（TEM）,fluorescence spectroscopy,and thermogravimetric analysis.Generally,exciting with visible light is advantageous over UV excitation.Of importance here is that,under excitation with visible light,the LnDB-OMT all show characteristic visible（Eu3＋,Sm3＋） as well as nearinfrared（Sm3＋,Yb3＋,Nd3＋） luminescence of the corresponding Ln3＋ ions（multicolor emission covered from 500 to 1400 nm spectral region）,which is attributed to the energy transfer from the ligands to the Ln3＋ ions via an antenna effect.