Initial Experience of NIR-II Fluorescence Imaging-Guided Surgery in Foot and Ankle Surgery

Optical imaging in the second near-infrared(NIR-II;900-1880 nm)window is currently a popular research topic in the field of biomedical imaging.This study aimed to explore the application value of NIR-II fluorescence imaging in foot and ankle surgeries.A lab-established NIR-II fluorescence surgical navigation system was developed and used to navigate foot and ankle surgeries which enabled obtaining more high-spatial-frequency information and a higher signal-to-background ratio(SBR)in NIR-II fluorescence images compared to NIR-I fluorescence images;our result demonstrates that NIR-II imaging could provide higher-contrast and larger-depth images to surgeons.Three types of clinical application scenarios(diabetic foot,calcaneal fracture,and lower extremity trauma)were included in this study.Using the NIR-II fluorescence imaging technique,we observed the ischemic region in the diabetic foot before morphological alterations,accurately determined the boundary of the ischemic region in the surgical incision,and fully assessed the blood supply condition of the flap.NIR-II fluorescence imaging can help surgeons precisely judge surgical margins,detect ischemic lesions early,and dynamically trace the perfusion process.We believe that portable and reliable NIR-II fluorescence imaging equipment and additional functional fluorescent probes can play crucial roles in precision surgery.

Interplay between the glymphatic system and neurotoxic proteins in Parkinson’s disease and related disorders:current knowledge and future directions

Parkinson’s disease is a common neurodegenerative disorder that is associated with abnormal aggregation and accumulation of neurotoxic proteins,includingα-synuclein,amyloid-β,and tau,in addition to the impaired elimination of these neurotoxic protein.Atypical parkinsonism,which has the same clinical presentation and neuropathology as Parkinson’s disease,expands the disease landscape within the continuum of Parkinson’s disease and related disorders.The glymphatic system is a waste clearance system in the brain,which is responsible for eliminating the neurotoxic proteins from the interstitial fluid.Impairment of the glymphatic system has been proposed as a significant contributor to the development and progression of neurodegenerative disease,as it exacerbates the aggregation of neurotoxic proteins and deteriorates neuronal damage.Therefore,impairment of the glymphatic system could be considered as the final common pathway to neurodegeneration.Previous evidence has provided initial insights into the potential effect of the impaired glymphatic system on Parkinson’s disease and related disorders;however,many unanswered questions remain.This review aims to provide a comprehensive summary of the growing literature on the glymphatic system in Parkinson’s disease and related disorders.The focus of this review is on identifying the manifestations and mechanisms of interplay between the glymphatic system and neurotoxic proteins,including loss of polarization of aquaporin-4 in astrocytic endfeet,sleep and circadian rhythms,neuroinflammation,astrogliosis,and gliosis.This review further delves into the underlying pathophysiology of the glymphatic system in Parkinson’s disease and related disorders,and the potential implications of targeting the glymphatic system as a novel and promising therapeutic strategy.

Magnetic field distribution in the cross section of Terfenol-D rod and its application

Whether the Terfenol-D rod should be laminated is of concern at the beginning of designing a magnetostrictive actuator for dynamic applications. Lamination can reduce the eddy current loss, but also decrease the stiffness of the GMM rod. The conventional way by is complicated FEM （Finite-Element Method） or one＇s experience. In this article an analytical approach of magnetic field distribution in the cross-section of the rod was described, and it was introduced as a reference method to judge if the Terfenol-D rod should be laminated. Numerical evaluation and experimental results proved the rationality and availability of the approach.

Impact of cognition-related single nucleotide polymorphisms on brain imaging phenotype in Parkinson’s disease

Multiple single nucleotide polymorphisms may contribute to cognitive decline in Parkinson’s disease. However, the mechanism by which these single nucleotide polymorphisms modify brain imaging phenotype remains unclear. The aim of this study was to investigate the potential effects of multiple single nucleotide polymorphisms on brain imaging phenotype in Parkinson’s disease. Forty-eight Parkinson’s disease patients and 39 matched healthy controls underwent genotyping and 7 T magnetic resonance imaging. A cognitive-weighted polygenic risk score model was designed, in which the effect sizes were determined individually for 36 single nucleotide polymorphisms. The correlations between polygenic risk score, neuroimaging features, and clinical data were analyzed. Furthermore, individual single nucleotide polymorphism analysis was performed to explore the main effects of genotypes and their interactive effects with Parkinson’s disease diagnosis. We found that, in Parkinson’s disease, the polygenic risk score was correlated with the neural activity of the hippocampus, parahippocampus, and fusiform gyrus, and with hippocampal-prefrontal and fusiform-temporal connectivity, as well as with gray matter alterations in the orbitofrontal cortex. In addition, we found that single nucleotide polymorphisms in α-synuclein(SNCA) were associated with white matter microstructural changes in the superior corona radiata, corpus callosum, and external capsule. A single nucleotide polymorphism in catechol-O-methyltransferase was associated with the neural activities of the lingual, fusiform, and occipital gyri, which are involved in visual cognitive dysfunction. Furthermore, DRD3 was associated with frontal and temporal lobe function and structure. In conclusion, imaging genetics is useful for providing a better understanding of the genetic pathways involved in the pathophysiologic processes underlying Parkinson’s disease. This study provides evidence of an association between genetic factors, cognitive functions, and multi-modality neuroimaging biomarkers in Parkinson’s disease.

Recentprogress in thebiomedical application of PEDOT:PSS hydrogels

Bioelectronics have gained substantial research attention owing to their potential applications in health monitoring and diagnose,and greatly promoted the development of biomedicine.Recently,poly(3,4-ethylenedioxythiophene):polystyrene sulfonate(PEDOT:PSS)hydrogels have arose as a promising candi-date for the next-generation bioelectronic interface due to its high-conductivity,versatility,flexibility and biocompatibility.In this review,we highlight the recent advances of PEDOT:PSS hydrogels,including the gelation methods and modification strategies,and summarize their wide applications in different type of sensors and tissue engineering in detail.We expect that this work will provide valuable information regarding the functionalizations and applications of PEDOT:PSS hydrogels.

Self-confocal NIR-II fluorescence microscopy for multifunctional in vivo imaging

Fluorescence imaging in the second near-infrared window(NIR-II,900–1880 nm)with less scattering background in biological tissues has been combined with the confocal microscopic system for achieving deep in vivo imaging with high spatial resolution.However,the traditional NIR-IIfluorescence confocal microscope with separate excitation focus and detection pinhole makes it possess low confocal e±ciency,as well as di±cultly to adjust.Two types of upgraded NIR-IIfluorescence confocal microscopes,sharing the same pinhole by excitation and emission focus,leading to higher confocal e±ciency,are built in this work.One type is-ber-pinhole-based confocal microscope applicable to CW laser excitation.It is constructed forfluorescence intensity imaging with large depth,high stabilization and low cost,which could replace multiphotonfluorescence microscopy in some applications(e.g.,cerebrovascular and hepatocellular imaging).The other type is air-pinhole-based confocal microscope applicable to femtosecond(fs)laser excitation.It can be employed not only for NIR-IIfluorescence intensity imaging,but also for multi-channelfluorescence lifetime imaging to recognize different structures with similarfluorescence spectrum.Moreover,it can be facilely combined with multiphotonfluorescence microscopy.A single fs pulsed laser is utilized to achieve up-conversion(visible multiphotonfluorescence)and down-conversion(NIR-II one-photonfluorescence)excitation simultaneously,extending imaging spectral channels,and thus facilitates multi-structure and multi-functional observation.

Dynamic Supercritical Fluid Devolatilization of Polymers

A number of studies have been reported on the applications of supercritical fluids to polymeric processes. The presence of volatiles can affect the end-use properties of polymer materials. Therefore, these volatiles must be reduced to a level below the maximum permissible limit. Conventional heat-relevant techniques for polymer devolatilization sometimes have limited effectiveness. Devolatilization with supercritical fluids, however, can enhance removal of volatiles from polymers. A model for diffusion-limited extraction is used to characterize dynamic supercritical fluid devolatilization of spherical polymer particles. The rate of supercritical fluid devolailization for styrene/polystyrene system is measured at 343 K and 18 MPa and at CO2 flow rate of 1.93, 3.27 and 5.62 L·min^-1, respectively. The model analysis, which is consistent with experimental results, indicates that the supercritical fluid devolatilization is not solubility-limited but diffusion-limited when CO2 flow rate is above 4.00 L·min^-1.

Review of 4Pi Fluorescence Nanoscopy

Since the 1990s,continuous technical and scientific advances have defied the diffraction limit in microscopy and enabled three-dimensional(3D)super-resolution imaging.An important milestone in this pursuit is the coherent utilization of two opposing objectives(4Pi geometry)and its combination with superresolution microscopy.Herein,we review the recent progress in 4Pi nanoscopy,which provides a 3D,non-invasive,diffraction-unlimited,and isotropic resolution in transparent samples.This review includes both the targeted and stochastic switching modalities of 4Pi nanoscopy.The schematics,principles,applications,and future potential of 4Pi nanoscopy are discussed in detail.

Room-Temperature Processed Amorphous ZnRhCuO Thin Films with p-Type Transistor and Gas-Sensor Behaviors

We examine an amorphous oxide semiconductor(AOS)of ZnRhCuO.The a-ZnRhCuO films are deposited at room temperature,having a high amorphous quality with smooth surface,uniform thickness and evenly distributed elements,as well as a high visible transmittance above 87%with a wide bandgap of 3.12 eV.Using a-ZnRhCuO films as active layers,thin-film transistors(TFTs)and gas sensors are fabricated.The TFT behaviors demonstrate the p-type nature of a-ZnRhCuO channel,with an on-to-off current ratio of^1×10^3 and field-effect mobility of0.079 cm^2 V^-1s^-1.The behaviors of gas sensors also prove that the a-ZnRhCuO films are of p-type conductivity.Our achievements relating to p-type a-ZnRhCuO films at room temperature with TFT devices may pave the way to practical applications of AOSs in transparent flexible electronics.

Contextual Fear Learning and Extinction in the Primary Visual Cortex of Mice

Fear memory contextualization is critical for selecting adaptive behavior to survive.Contextual fear conditioning(CFC)is a classical model for elucidating related underlying neuronal circuits.The primary visual cortex(V1)is the primary cortical region for contextual visual inputs,but its role in CFC is poorly understood.Here,our experiments demonstrated that bilateral inactivation of V1 in mice impaired CFC retrieval,and both CFC learning and extinction increased the turnover rate of axonal boutons in V1.The frequency of neuronal Ca^(2+)activity decreased after CFC learning,while CFC extinction reversed the decrease and raised it to the naïve level.Contrary to control mice,the frequency of neuronal Ca^(2+)activity increased after CFC learning in microglia-depleted mice and was maintained after CFC extinction,indicating that microglial depletion alters CFC learning and the frequency response pattern of extinction-induced Ca^(2+)activity.These findings reveal a critical role of microglia in neocortical information processing in V1,and suggest potential approaches for cellular-based manipulation of acquired fear memory.

Non-invasive photoacoustic computed tomography of rat heart anatomy and function

Complementary to mainstream cardiac imaging modalities for preclinical research,photoacoustic computed tomography(PACT)can provide functional optical contrast with high imaging speed and resolution.However,PACT has not been demonstrated to reveal the dynamics of whole cardiac anatomy or vascular system without surgical procedure(thoracotomy)for tissue penetration.Here,we achieved non-invasive imaging of rat hearts using the recently developed three-dimensional PACT(3D-PACT)platform,demonstrating the regulated illumination and detection schemes to reduce the effects of optical attenuation and acoustic distortion through the chest wall;thereby,enabling unimpeded visualization of the cardiac anatomy and intracardiac hemodynamics following rapidly scanning the heart within 10 s.We further applied 3D-PACT to reveal distinct cardiac structural and functional changes among the healthy,hypertensive,and obese rats,with optical contrast to uncover differences in cardiac chamber size,wall thickness,and hemodynamics.Accordingly,3D-PACT provides high imaging speed and nonionizing penetration to capture the whole heart for diagnosing the animal models,holding promises for clinical translation to cardiac imaging of human neonates.

Transcranial Acoustic Metamaterial Parameters Inverse Designed by Neural Networks

Objective:The objective of this work is to investigate the mapping relationship between transcranial ultrasound image quality and transcranial acoustic metamaterial parameters using inverse design methods.Impact Statement:Our study provides insights into inverse design methods and opens the route to guide the preparation of transcranial acoustic metamaterials.Introduction:The development of acoustic metamaterials has enabled the exploration of cranial ultrasound,and it has been found that the influence of the skull distortion layer on acoustic waves can be effectively eliminated by adjusting the parameters of the acoustic metamaterial.However,the interaction mechanism between transcranial ultrasound images and transcranial acoustic metamaterial parameters is unknown.Methods:In this study,1,456 transcranial ultrasound image datasets were used to explore the mapping relationship between the quality of transcranial ultrasound images and the parameters of transcranial acoustic metamaterials.Results:The multioutput parameter prediction model of transcranial metamaterials based on deep back-propagation neural network was built,and metamaterial parameters under transcranial image evaluation indices are predicted using the prediction model.Conclusion:This inverse big data design approach paves the way for guiding the preparation of transcranial metamaterials.

The Dynamic Mortise-and-Tenon Interlock Assists Hydrated Soft Robots Toward Off-Road Locomotion

Natural locomotion such as walking,crawling,and swimming relies on spatially controlled deformation of soft tissues,which could allow efficient interaction with the external environment.As one of the ideal candidates for biomimetic materials,hydrogels can exhibit versatile bionic morphings.However,it remains an enormous challenge to transfer these insitu deformations to locomotion,particularly above complex terrains.Herein,inspired by the crawling mode of inchworms,an isotropic hydrogel with thermoresponsiveness could evolve to an anisotropic hydrogel actuator via interfacial diffusion polymerization,further evolving to multisection structure and exhibiting adaptive deformation with diverse degrees of freedom.Therefore,a dynamic mortise-and-tenon interlock could be generated through the interaction between the self-deformation of the hydrogel actuator and rough terrains,inducing continual multidimensional locomotion on various artificial rough substrates and natural sandy terrain.Interestingly,benefiting from the powerful mechanical energy transfer capability,the crawlable hydrogel actuators could also be utilized as hydrogel motors to activate static cargos to overstep complex terrains,which exhibit the potential application of a biomimetic mechanical discoloration device.Therefore,we believe that this design principle and control strategy may be of potential interest to the field of deformable materials,soft robots,and biomimetic devices.

Perivascular spaces relate to the course and cognition of Huntington’s disease

Huntington’s disease(HD)is an autosomal dominant neurodegenerative disease that is caused by a cytosine-adenine-guanine(CAG)expansion in the first exon of the huntingtin(HTT)gene,which codes for the hun-tingtin protein.It typically manifests with a triad of symptoms,including motor disorders,cognitive impair-ment and psychiatric disturbances[1].HD primar-ily affects the basal ganglia(BG),especially the caudate and putamen,after which it extends to more widespread gray and white matter[2].Perivascular spaces(PVSs)are fluid-filled extensions of the subarachnoid spaces that enclose cerebral blood vessels and extend from the cer-ebral cortex through the brain parenchyma.The physi-ological role of PVSs is the drainage of brain interstitial fluid into perivascular pathways for the elimination of waste products through the glymphatic drainage sys-tem.An increasing number of studies have demonstrated that enlarged PVSs indicate glymphatic dysfunction and are associated with many neurological diseases,such as Alzheimer’s disease,Parkinson’s disease and small vessel disease[3].With the advantage of strong field strengths,7.0 T images show superior resolution and signal-to-noise ratios than 3.0 T,which facilitate the visualization of PVS.And automated segmentation methods could accurately identify PVS in a short time with no inter-rater variability.In the current study,we used U-shaped networks(U-net),a class of deep learning methods,to explore the PVS distribution in HD and controls.To date,PVS distribution in HD is still unclear.Only two studies have investigated PVSs in HD,and both dem-onstrated increased visible PVS burden in manifest HD compared to controls[4,5].However,whether PVS bur-den increases in premanifest HD(pre-HD)individuals remains unknown,and the relationship of PVS with cog-nitive decline has never been studied.

Computed tomography-based delta radiomics of tumor core_edge combination for systemic treatment response evaluation in pancreatic cancer

Background:As a systemic disease,pancreatic cancer(PC)can be treated systemically to raise the R0 resection rate and enhance patient prognosis.The best ways to assess the treatment response to systemic treatment of patients with PC are still lacking.Methods:A total of 122 PC patients were enrolled;25 of these patients were used as an independent testing set.According to the pathologic response,PC patients were classified into the responder and nonresponder groups.The whole tumor,core,edge,and peritumoral were segmented from the enhanced computed tomography(CT)images.Machine-learning models were created by extracting the variations in radionics features before and after therapy(delta radiomics features).Finally,we compared the performance of models based on radiomics features,changes in tumor markers,and radiologic evaluation.Results:The model based on the core(area under curve[AUC]=0.864)and edge features(AUC=0.853)showed better performance than that based on the whole tumor(AUC=0.847)or peritumoral area(AUC=0.846).Moreover,the tumor core_edge combination model(AUC=0.899)could better increase confidence in treatment response than using either of them alone.The accuracies of models based on changes in tumor markers and radiologic evaluation were relatively poorer than of the radiomics model.Moreover,Patients predicted to respond to therapy using the radiomics model showed a relatively longer overall survival(43 vs 27 months),although there were no significant differences(P=.063).Conclusions:The tumor core_edge combination delta radiomics model is an effective approach to evaluate pathologic response in PC patients with systemic treatment.

A remote control training system for rat navigation in complicated environment

A remote control system has been developed to deliver stimuli into the rat brain through a wireless micro-stimulator for animal behavior training. The system consists of the following main components： an integrated PC control program, a transmitter and a receiver based on Bluetooth （BT） modules, a stimulator controlled by C8051 microprocessor, as well as an operant chamber and an eight-arm radial maze. The micro-stimulator is featured with its changeable amplitude of pulse output for both constant-voltage and constant-current mode, which provides an easy way to set the proper suitable stimulation intensity for different training. The system has been used in behavior experiments for monitoring and recording bar-pressing in the operant chamber, controlling rat roaming in the eight-arm maze, as well as navigating rats through a 3D obstacle route. The results indicated that the system worked stably and that the stimulation was effective for different types of rat behavior controls. In addition, the results showed that stimulation in the whisker barrel region of rat primary somatosensory cortex （SI） acted like a cue. The animals can be trained to take different desired turns upon the association between the SI cue stimulation and the reward stimulation in the medial forehrain bundle （MFB）.

Structural,Functional,and Molecular Imaging of Autism Spectrum Disorder

Autism spectrum disorder(ASD)is a heterogeneous neurodevelopmental disorder associated with both genetic and environmental risks.Neuroimaging approaches have been widely employed to parse the neurophysiological mechanisms underlying ASD,and provide critical insights into the anatomical,functional,and neurochemical changes.We reviewed recent advances in neuroimaging studies that focused on ASD by using magnetic resonance imaging(MRI),positron emission tomography(PET),or single-positron emission tomography(SPECT).Longitudinal structural MRI has delineated an abnormal developmental trajectory of ASD that is associated with cascading neurobiological processes,and functional MRI has pointed to disrupted functional neural networks.Meanwhile,PET and SPECT imaging have revealed that metabolic and neurotransmitter abnormalities may contribute to shaping the aberrant neural circuits of ASD.Future large-scale,multi-center,multimodal investigations are essential to elucidate the neurophysiological underpinnings of ASD,and facilitate the development of novel diagnostic biomarkers and better-targeted therapy.

Resveratrol promotes the survival and neuronal differentiation of hypoxia-conditioned neuronal progenitor cells in rats with cerebral ischemia

Hypoxia conditioning could increase the survival of transplanted neuronal progenitor cells(NPCs)in rats with cerebral ischemia but could also hinder neuronal differentiation partly by suppressing mitochondrial metabolism.In this work,the mitochondrial metabolism of hypoxia-conditioned NPCs(hcNPCs)was upregulated via the additional administration of resveratrol,an herbal compound,to resolve the limitation of hypoxia conditioning on neuronal differentiation.Resveratrol was first applied during the in vitro neuronal differentiation of hcNPCs and concurrently promoted the differentiation,synaptogenesis,and functional development of neurons derived from hcNPCs and restored the mitochondrial metabolism.Furthermore,this herbal compound was used as an adjuvant during hcNPC transplantation in a photothrombotic stroke rat model.Resveratrol promoted neuronal differentiation and increased the long-term survival of transplanted hcNPCs.18-fluorine fluorodeoxyglucose positron emission tomography and rotarod test showed that resveratrol and hcNPC transplantation synergistically improved the neurological and metabolic recovery of stroke rats.In conclusion,resveratrol promoted the neuronal differentiation and therapeutic efficiency of hcNPCs in stroke rats via restoring mitochondrial metabolism.This work suggested a novel approach to promote the clinical translation of NPC transplantation therapy.

Design of hierarchical and mesoporous FeF_(3)/rGO hybrids as cathodes for superior lithium-ion batteries

Iron fluoride(FeF_(3)) is considered as a promising cathode material for Li-ion batteries(LIBs)due to its high theoretical capacity(712 mAh/g)with a 3 e-transfer.Herein,we have designed a strategy of hierarchical and mesoporous FeF_(3)/rG O hybrids for LIBs,where the hollow Fe F_(3) nanospheres are the main contributor to the specific capacity and the 2 D r GO nanosheets are the matrix elevating the electronic conductivity and buffering the volume expansion.The unique FeF_(3)/rGO hybrid can be rationally synthesized by a nonaqueous in-situ precipitation method,offering the merits of large specific surface area with rich active sites,fast transport channels for lithium ions,effective alleviation of volume expansion during cycles,and accelerating the electrochemical reaction kinetics.The Fe F_(3)/r GO hybrid electrode possesses a high initial discharge capacity of 553.9 m Ah/g at a rate of 0.5 C with 378 m Ah/g after 100 cycles,acceptable rate capability with 168 m Ah/g at 2 C,and feasible high-temperature operation(320 m Ah/g at 70℃).The superior electrochemical behaviors presented here demonstrates that the FeF_(3)/rGO hybrid is a potential electrode for LIBs,which may open up a new vision to design high-efficiency energy-storage devices such as LIBs based on transition metal fluorides.

Hot-band absorption of indocyanine green for advanced anti-stokes fluorescence bioimaging

Bright anti-Stokes fluorescence(ASF)in the first near-infrared spectral region(NIR-I,800 nm–900 nm)under the excitation of a 915 nm continuous wave(CW)laser,is observed in Indocyanine Green(ICG),a dye approved by the Food and Drug Administration for clinical use.The dependence of fluorescence intensity on excitation light power and temperature,together with fluorescence lifetime measurement,establish this ASF to be originated from absorption from a thermally excited vibrational level(hot-band absorption),as shown in our experiments,which is stronger than the upconversion fluorescence from widely-used rare-earth ion doped nanoparticles.To test the utility of this ASF NIR-I probe for advanced bioimaging,we successively apply it for biothermal sensing,cerebral blood vessel tomography and blood stream velocimetry.Moreover,in combination with L1057 nanoparticles,which absorb the ASF of ICG and emit beyond 1100 nm,these two probes generate multi-mode images in two fluorescent channels under the excitation of a single 915 nm CW laser.One channel is used to monitor two overlapping organs,urinary system&blood vessel of a live mouse,while the other shows urinary system only.Using in intraoperative real-time monitoring,such multi-mode imaging method can be beneficial for visual guiding in anatomy of the urinary system to avoid any accidental injury to the surrounding blood vessels during surgery.