Design and simulation of an accelerometer based on NV center spin–strain coupling

The nitrogen-vacancy (NV) center quantum systems have emerged as versatile tools in the field of precision measurement because of their high sensitivity in spin state detection and miniaturization potential as solid-state platforms.In this paper,an acceleration sensing scheme based on NV spin–strain coupling is proposed,which can effectively eliminate the influence of the stray noise field introduced by traditional mechanical schemes.Through the finite element simulation,it is found that the measurement bandwidth of this ensemble NV spin system ranges from 3 kHz to hundreds of kHz with structure√optimization.The required power is at the sub-μW level,corresponding to a noise-limited sensitivity of 6.7×10^(-5) /√Hz.Compared with other types of accelerometers,this micro-sized diamond sensor proposed here has low power consumption,exquisite sensitivity,and integration potential.This research opens a fresh perspective to realize an accelerometer with appealing comprehensive performance applied in biomechanics and inertial measurement fields.

Human natural killer cells for targeting delivery of gold nanostars and bimodal imaging directed photothermal/photodynamic therapy and immunotherapy

Objective:To construct a novel nanoplatform GNS@CaCO3/Ce6-NK by loading the CaCO3-coated gold nanostars(GNSs)with Chlorin e6 molecules(Ce6)into human peripheral blood mononuclear cells(PBMCs)-derived NK cells for tumor targeted therapy.Methods:GNS@CaCO3/Ce6 nanoparticles were prepared and characterized by TEM and UV-vis.The cell surface markers and cytokines secretion of NK cells before and after loading the GNS@CaCO3/Ce6 nanoparticles were detected by Flow Cytometry(FCM)and ELISA.Effects of the GNS@CaCO3/Ce6-NK cells on A549 cancer cells was determined by FCM and CCK-8.Intracellular fluorescent signals of GNS@CaCO3/Ce6-NK cells were detected via Confocal laser scanning microscopic(CLSM)and FCM at different time points.Intracellular ROS generation of GNS@CaCO3/Ce6-NK cells under laser irradiation were examined by FCM.The distribution of GNS@CaCO3/Ce6-NK in A549 tumor-bearing mice were observed by fluorescence imaging and PA imaging.The combination therapy of GNS@CaCO3/Ce6-NK under laser irradiation were investigated on tumor-bearing mice.Results:The coated CaC03 shell on the surface of GNSs exhibited prominent delivery and protection effect of Ce6 during the cellular uptake process.The as-prepared multifunctional GNS@CaCO3/Ce6-NK cells possessed bimodal functions of fluorescence imaging and photoacoustic imaging.The as-prepared multifunctional GNS@CaCO3/Ce6-NK cells could actively target tumor tissues with the enhanced photothermal/photodynamic therapy and immunotherapy.Conclusions:The GNS@CaCO3/Ce6-NK shows effective tumor-targeting ability and prominent therapeutic efficacy toward lung cancer A549 tumor-bearing mice.Through fully utilizing the features of GNSs and NK cells,this new nanoplatform provides a new synergistic strategy for enhanced photothermal/photodynamic therapy and immunotherapy in the field of anticancer development in the near future.

Boosting of reversible capacity delivered at a low voltage below 0.5 V in mildly expanded graphitized needle coke anode for a high-energy lithium ion battery

The rate performance and cycle stability of graphitized needle coke(GNC)as anode are still limited by the sluggish kinetics and volume expansion during the Li ions intercalation and de-intercalation process.Especially,the output of energy density for lithium ion batteries(LIBs)is directly affected by the delithiation capacity below 0.5 V.Here,the mildly expanded graphitized needle coke(MEGNC)with the enlarged interlayer spacing from 0.346 to 0.352 nm is obtained by the two-step mild oxidation intercalation modification.The voltage plateau of MEGNC anode below 0.5 V is obviously broadened as compared to the initial GNC anode,contributing to the enhancement of Li storage below the low voltage plateau.Moreover,the coin full cell and pouch full cell configured with MEGNC anode exhibit much enhanced Li storage ability,energy density and better cycling stability than those full cells configured with GNC and commercial graphite anodes,demonstrating the practical application value of MEGNC.The superior anode behaviors of MEGNC including the increased effective capacity at low voltage and superior cyclic stability are mainly benefited from the enlarged interlayer spacing,which not only accelerates the Li ions diffusion rate,but also effectively alleviates the volume expansion and fragmentation during the Li ions intercalation process.In addition,the above result is further confirmed by the density functional theory simulation.This work provides an effective modification strategy for the NC-based graphite to enhance the delithiation capacity at a low voltage plateau,dedicated to improving the energy density and durability of LIBs.

A Review on Metal-and Metal Oxide-Based Nanozymes:Properties,Mechanisms,and Applications

Since the ferromagnetic(Fe_(3)O_(4))nanoparticles were firstly reported to exert enzyme-like activity in 2007,extensive research progress in nanozymes has been made with deep investigation of diverse nanozymes and rapid development of related nanotechnologies.As promising alterna-tives for natural enzymes,nanozymes have broadened the way toward clinical medicine,food safety,environmental monitoring,and chemical production.The past decade has witnessed the rapid development of metal-and metal oxide-based nanozymes owing to their remarkable physicochemical proper-ties in parallel with low cost,high stability,and easy storage.It is widely known that the deep study of catalytic activities and mechanism sheds sig-nificant influence on the applications of nanozymes.This review digs into the characteristics and intrinsic properties of metal-and metal oxide-based nanozymes,especially emphasizing their catalytic mechanism and recent applications in biological analysis,relieving inflammation,antibacterial,and cancer therapy.We also conclude the present challenges and provide insights into the future research of nanozymes constituted of metal and metal oxide nanomaterials.

Ultrasound Imaging of Pipeline Crack Based on Composite Transducer Array

Cracks, especially small cracks are di cult to be detected in oil and gas transportation pipelines buried underground or covered with layers of material by using the traditional ultrasonic inspection techniques. Therefore, a new com?posite ultrasonic transducer array with three acoustic beam incidence modes is developed. The space model of the array is also established to obtain the defect reflection point location. And the crack ultrasound image is thus formed through a series of small cubical elements expanded around the point locations by using the projection of binariza?tion values extracted from the received ultrasonic echo signals. Laboratory experiments are performed on a pipeline sample with di erent types of cracks to verify the e ectiveness and performance of the proposed technique. From the image, the presence of small cracks can be clearly observed, in addition to the sizes and orientations of the cracks. The proposed technique can not only inspect common flaws, but also detect cracks with various orientations, which is helpful for defect evaluation in pipeline testing.

Machine Learning Approach to Enhance the Performance of MNP?Labeled Lateral Flow Immunoassay

The use of magnetic nanoparticle(MNP)-labeled immunochromatography test strips(ICTSs) is very important for point-ofcare testing(POCT). However, common diagnostic methods cannot accurately analyze the weak magnetic signal from ICTSs, limiting the applications of POCT. In this study, an ultrasensitive multiplex biosensor was designed to overcome the limitations of capturing and normalization of the weak magnetic signal from MNPs on ICTSs. A machine learning model for sandwich assays was constructed and used to classify weakly positive and negative samples, which significantly enhanced the specificity and sensitivity. The potential clinical application was evaluated by detecting 50 human chorionic gonadotropin(HCG) samples and 59 myocardial infarction serum samples. The quantitative range for HCG was 1–1000 mIU mL^(-1) and the ideal detection limit was 0.014 mIU mL^(-1), which was well below the clinical threshold. Quantitative detection results of multiplex cardiac markers showed good linear correlations with standard values. The proposed multiplex assay can be readily adapted for identifying other biomolecules and also be used in other applications such as environmental monitoring, food analysis, and national security.

N-doped coaxial CNTs@a-Fe_2O_3@C nanofibers as anode material for high performance lithium ion battery

N-doped coaxial CNTs@α-Fe_2O_3@C nanofibers have been successfully synthesized according to a facile solvothermal/hydrothermal method. The obtained CNTs@α-Fe_2O_3@C nanofibers composites exhibited spe- cial three-dimensional （3-D） network structure, which endows they promising candidate for anode ma- terials of lithium ion battery. The coaxial property of CNTs@α-Fe_2O_3@C nanofibers could significantly improve the cycling and rate performance owing to the acceleration of charge/electron transfer, improve- ment of conductivity, maintaining of structural integrity and inhibiting the aggregation. The α-Fe_2O_3 nanoparticles with small size and high percentage of N-doped amount could further improve the elec- trochemical performance. As for the CNTs@α-Fe_2O_3@C nanofibers, the capacity presented a high value of 1255.4 mAh/g at 0.1 C, and retained at 1213.4 mAh/g after 60 cycles. Even at high rate of 5 C, the ca- pacity still exhibited as high as 319 mAh/g. The results indicated that the synthesized N-doped coaxial CNTs@α-Fe_2O_3@C nanofibers exhibited high cvcling and rate oerformance.

Human iPS Cells Loaded with MnO2-Based Nanoprobes for Photodynamic and Simultaneous Enhanced Immunotherapy Against Cancer

How to trigger strong anti-tumor immune responses has become a focus for tumor therapy.Here,we report the human-induced pluripotent stem cells(iPSs)to deliver MnO2@Ce6 nanoprobes into tumors for simultaneous photodynamic therapy(PDT)and enhanced immunotherapy.Ce6 photosensitizer was attached on manganese dioxide(MnO2)nanoparticles,and resultant MnO2@Ce6 nanoprobes were delivered into mitomycin-treated iPSs to form iPS-MnO2@Ce6 nanoprobes.The iPS-MnO2@Ce6 actively targeted in vivo tumors,the acidic microenvironment triggered interaction between MnO2 and H2O2,released large quantities of oxygen,alleviated hypoxia in tumor.Upon PDT,singlet oxygen formed,broken iPSs released tumor-shared antigens,which evoked an intensive innate and adaptive immune response against the tumor,improving dendritic cells matured,effector T cells,and natural killer cells were activated.Meanwhile,regulatory T cells were reduced,and then the immune response induced by iPS-MnO2@Ce6 was markedly stronger than the immune reaction induced by MnO2@Ce6(P<0.05).The iPS-MnO2@Ce6 markedly inhibited tumor growth and metastasis and reduced mortality in mice models with tumor.Human iPS s loaded with MnO2-based nanoprobes are a promising strategy for simultaneous PDT and enhanced immunotherapy against tumor and own clinical translational prospect.

Analysis of heart rate variability based on singular value decomposition entropy

Assessing the dynamics of heart rate fluctuations can provide valuable information about heart status. In this study, regularity of heart rate variability （HRV） of heart failure patients and healthy persons using the concept of singular value decomposition entropy （SvdEn） is analyzed. SvdEn is calculated from the time series using normalized singular values. The advantage of this method is its simplicity and fast computation. It enables analysis of very short and non-stationary data sets. The results show that SvdEn of patients with congestive heart failure （CHF） shows a low value （SvdEn： 0.056±0.006, p 〈 0.01） which can be completely separated from healthy subjects. In addition, differences of SvdEn values between day and night are found for the healthy groups. SvdEn decreases with age. The lower the SvdEn values, the higher the risk of heart disease. Moreover, SvdEn is associated with the energy of heart rhythm. The results show that using SvdEn for discriminating HRV in different physiological states for clinical applications is feasible and simple.

Controlling the Reconstruction of Ni/CeO_(2) Catalyst during Reduction for Enhanced CO Methanation

Reductive pretreatment is an important step for activating supported metal catalysts but has received little attention.In this study,reconstruction of the supported nickel catalyst was found to be sensitive to pretreatment conditions.In contrast to the traditional activation procedure in hydrogen,activating the catalyst in syngas created supported Ni nanoparticles with a polycrystalline structure containing an abundance of grain boundaries.The unique post-activation catalyst structure offered enhanced CO adsorption and an improved CO methanation rate.The current strategy to tune the catalyst structure via manipulating the activation conditions can potentially guide the rational design of other supported metal catalysts.

Human induced pluripotent stem cells labeled with fluorescent magnetic nanoparticles for targeted imaging and hyperthermia therapy for gastric cancer

Objective: Human induced pluripotent stem(i PS) cells exhibit great potential for generating functional human cells for medical therapies. In this paper, we report for use of human i PS cells labeled with fluorescent magnetic nanoparticles(FMNPs) for targeted imaging and synergistic therapy of gastric cancer cells in vivo. Methods: Human i PS cells were prepared and cultured for 72 h. The culture medium was collected, and then was coincubated with MGC803 cells. Cell viability was analyzed by the MTT method. FMNP-labeled human i PS cells were prepared and injected into gastric cancer-bearing nude mice. The mouse model was observed using a small-animal imaging system. The nude mice were irradiated under an external alternating magnetic field and evaluated using an infrared thermal mapping instrument. Tumor sizes were measured weekly. Results: iP S cells and the collected culture medium inhibited the growth of MGC803 cells. FMNP-labeled human iP S cells targeted and imaged gastric cancer cells in vivo, as well as inhibited cancer growth in vivo through the external magnetic field. Conclusion: FMNP-labeled human i PS cells exhibit considerable potential in applications such as targeted dual-mode imaging and synergistic therapy for early gastric cancer.

Parameters optimization and nonlinearity analysis of grating eddy current displacement sensor using neural network and genetic algorithm

A grating eddy current displacement sensor(GECDS) can be used in a watertight electronic transducer to realize long range displacement or position measurement with high accuracy in difficult industry conditions.The parameters optimization of the sensor is essential for economic and efficient production.This paper proposes a method to combine an artificial neural network(ANN) and a genetic algorithm(GA) for the sensor parameters optimization.A neural network model is developed to map the complex relationship between design parameters and the nonlinearity error of the GECDS,and then a GA is used in the optimization process to determine the design parameter values,resulting in a desired minimal nonlinearity error of about 0.11%.The calculated nonlinearity error is 0.25%.These results show that the proposed method performs well for the parameters optimization of the GECDS.

The updated landscape of tumor microenvironment and drug repurposing

Accumulating evidence shows that cellular and acellular components in tumor microenvironment(TME)can reprogram tumor initiation,growth,invasion,metastasis,and response to therapies.Cancer research and treatment have switched from a cancercentric model to a TME-centric one,considering the increasing significance of TME in cancer biology.Nonetheless,the clinical efficacy of therapeutic strategies targeting TME,especially the specific cells or pathways of TME,remains unsatisfactory.Classifying the chemopathological characteristics of TME and crosstalk among one another can greatly benefit further studies exploring effective treating methods.Herein,we present an updated image of TME with emphasis on hypoxic niche,immune microenvironment,metabolism microenvironment,acidic niche,innervated niche,and mechanical microenvironment.We then summarize conventional drugs including aspirin,celecoxib,β-adrenergic antagonist,metformin,and statin in new antitumor application.These drugs are considered as viable candidates for combination therapy due to their antitumor activity and extensive use in clinical practice.We also provide our outlook on directions and potential applications of TME theory.This review depicts a comprehensive and vivid landscape of TME from biology to treatment.

Microglia in neurodegenerative diseases

A major feature of neurodegeneration is disruption of central nervous system homeostasis,during which microglia play diverse roles.In the central nervous system,microglia serve as the first line of immune defense and function in synapse pruning,injury repair,homeostasis maintenance,and regulation of brain development through scavenging and phagocytosis.Under pathological conditions or various stimulations,microglia proliferate,aggregate,and undergo a variety of changes in cell morphology,immunophenotype,and function.This review presents the features of microglia,especially their diversity and ability to change dynamically,and reinterprets their role as sensors for multiple stimulations and as effectors for brain aging and neurodegeneration.This review also summarizes some therapeutic approaches for neurodegenerative diseases that target microglia.

Rapid classification of copper concentrate by portable laser-induced breakdown spectroscopy combined with transfer learning and deep convolutional neural network

This paper investigates the combination of laser-induced breakdown spectroscopy〔LIBS〕and deep convolutional neural networks〔CNNs〕to classify copper concentrate samples using pretrained CNN models through transfer learning.Four pretrained CNN models were compared.The LIBS profiles were augmented into 2D matrices.Three transfer learning methods were tried.All the models got a high classification accuracy of>92%,with the highest at 96.2%for VGG16.These results suggested that the knowledge learned from machine vision by the CNN models can accelerate the training process and reduce the risk of overfitting.The results showed that deep CNN and transfer learning have great potential for the classification of copper concentrates by portable LIBS.

In vivo and in situ real-time fluorescence imaging of peripheral nerves in the NIR-II window

The peripheral nervous system(PNS)is essential for performing and maintaining various motor and sensory functions.Abnormalities can lead to a series of peripheral neurological conditions,such as paraesthesia,pain,or spasms,which are debilitating and lowering the quality of life.Thecurrent guidelines for diagnosis rely predominantly on clinical symptoms resulting from PNS dysfunction,which occur already at an advancedstage.There are currently no effective methods that visually reflect the extent of peripheral neuropathy.In our study,we present a novel in vivoand in situ real-time imaging of peripheral nerves based on the second near-infrared window(NIR-II)fluoresce nee.In NIR-II system,lead sulfidequa ntum dots(PbS Qds)with NIR-II fluoresce nee specifically bound to motor neuro rvspecific protein agrin,acting as image con trast.In micemodel,peripheral nerves were visible as soon as after 2 h post injection.We provide evidenee for the efficacy of this approach,which allows todirectly dem on strate peripheral nerves,their structure,and pote ntial damagesites and degree.Furthermore,our products were of goodbiocompatibility,while the n eural fluoresce nee signal was solid,bright and stable for 4 h in vivo.Thus,overall,our results suggest that NIR-II isan effective new method for direct imaging of peripheral nerves in vivo,opening new horizons on early,improved and more precise,targeteddiag no sis.A resulti ng more rapid installatio n of perso nalized therapy facilitates a better prognosis of clinical peripheral neuropathy.

C60 Fullerenes Suppress Reactive Oxygen Species Toxicity Damage in Boar Sperm

We report the carboxylated C60 improved the survival and quality of boar sperm during liquid storage at 4°C and thus propose the use of carboxylated C60 as a novel antioxidant semen extender supplement.Our results demonstrated that the sperm treated with 2μg mL?1 carboxylated C60 had higher motility than the control group(58.6%and 35.4%,respectively;P?0.05).Moreover,after incubation with carboxylated C60 for 10 days,acrosome integrity and mitochondrial activity of sperm increased by 18.1%and 34%,respectively,compared with that in the control group.Similarly,the antioxidation abilities and adenosine triphosphate levels in boar sperm treated with carboxylated C60 significantly increased(P?0.05)compared with those in the control group.The presence of carboxylated C60 in semen extender increases sperm motility probably by suppressing reactive oxygen species(ROS)toxicity damage.Interestingly,carboxylated C60 could protect boar sperm from oxidative stress and energy deficiency by inhibiting the ROS-induced protein dephosphorylation via the cAMP-PKA signaling pathway.In addition,the safety of carboxylated C60 as an alternative antioxidant was also comprehensively evaluated by assessing the mean litter size and number of live offspring in the carboxylated C60 treatment group.Our findings confirm carboxylated C60 as a novel antioxidant agent and suggest its use as a semen extender supplement for assisted reproductive technology in domestic animals.

Fluorescence detection of phosphate in an aqueous environment by an aluminum-based metal-organic framework with amido functionalized ligands

The on-site monitoring of phosphate is important for environmental management.Conventional phosphate detection methods are not appropriate to on-site monitoring owing to the use of complicated detection procedures,and the consequent high cost and maintenance requirements of the detection apparatus.Here,a highly sensitive fluorescence-based method for phosphate detection with a wide detection range was developed based on a luminescent aluminum-based metal-organic framework(Al-MOF).The Al-MOF was prepared by introducing amine functional groups to conventional MIL to enhance phosphate binding,and exhibited excellent fluorescence properties that originated from the ligand-to-metal charge transfer(LMCT).The detection limit was as low as 3.25µmol/L(0.10 mg/L)and the detection range was as wide as 3–350µmol/L(0.10–10.85 mg/L).Moreover,Al-MOF displayed specific recognition toward phosphate over most anions and metal cations,even for a high concentration of the co-existent ions.The mechanism of phosphate detection was analyzed through the characterization of the combination of Al-MOF and phosphate,and the results indicated the high affinity between Al-O and phosphate inhibited that the LMCT process and recovered the intrinsic fluorescence of NH2−H2BDC.The recovery of the developed detection method reached a satisfactory range of 85.1%–111.0%,and the feasibility of on-site phosphate detection was verified using a prototype sensor for tap water and lake water samples.It was demonstrated that the prepared Al-MOF is highly promising for on-site detection of phosphate in an aqueous environment.

Safety Protection Method of Rehabilitation Robot Based on fNIRS and RGB-D Information Fusion

In order to improve the safety protection performance of the rehabilitation robot,an active safety protection method is proposed in the rehabilitation scene.The oxyhemoglobin concentration information and RGB-D information are combined in this method,which aims to realize the comprehensive monitoring of the invasion target,the patient’s brain function movement state,and the joint angle in the rehabilitation scene.The main focus is to study the fusion method of the oxyhemoglobin concentration information and RGB-D information in the rehabilitation scene.Frequency analysis of brain functional connectivity coefficient was used to distinguish the basic motion states.The human skeleton recognition algorithm was used to realize the angle monitoring of the upper limb joint combined with the depth information.Compared with speed and separation monitoring,the protection method of multi-information fusion is safer and more comprehensive for stroke patients.By building the active safety protection platform of the upper limb rehabilitation robot,the performance of the system in different safety states is tested,and the safety protection performance of the method in the upper limb rehabilitation scene is verified.

Insulation condition forewarning of form-wound winding for electric aircraft propulsion based on partial discharge and deep learning neural network

Form-wound windings in electric machines designed for electric aircraft propulsion face reliability challenges due to the severe operating environment,such as high temperature and low pressure.This study proposes a forewarning method for insulation condition monitoring of form-wound windings based on partial discharge(PD)and deep learning neural network.Three PD features are extracted from the PD profile,which provides information about physics-of-failure and reflects the degree of insulation degradation.An algorithm fusion extracted from auto-encoder and long short-term recurrent neural network is proposed to synthesize one failure precursor from these three features and make multi-time-step prediction through historical data to provide forewarning.An electrical and thermal accelerated ageing test is performed on the form-wound windings at 0.2 atm to simulate working environment of electric aircraft.The proposed method is validated on the accelerated ageing dataset and shows better prediction accuracy than some existing time-series prediction methods,indicating the advantages of the proposed method.Moreover,an on-line hardware setup using a deep learning processor is rec-ommended to implement the forewarning method.The proposed approach has the potential to be widely applied to other insulation systems and contribute to work on condition monitoring.