A multimodal framework based on deep belief network for human locomotion intent prediction.

Accurate prediction of human locomotion intent benefits the seamless switching of lower limb exoskeleton controllers in different terrains to assist humans in walking safely. In this paper, a deep belief network (DBN) was developed to construct a multimodal framework for recognizing various locomotion modes and predicting transition tasks. Three fusion strategies (data level, feature level, and decision level) were explored, and optimal network performance was obtained. This method could be tested on public datasets. For the continuous performance of steady state, the best prediction accuracy achieved was 97.64% in user-dependent testing and 96.80% in user-independent testing. During the transition state, the system accurately predicted all transitions (user-dependent: 96.37%, user-independent: 95.01%). The multimodal framework based on DBN can accurately predict the human locomotion intent. The experimental results demonstrate the potential of the proposed model in the volition control of the lower limb exoskeleton.

Core-shell structure DA-CDs/AuNPs for the recognition of fenamidone by surface-enhanced Raman scattering.

In this work, a facile synthesis method for dopamine carbon dots-based Au nanoparticles (DA-CDs/AuNPs) by seed gold method was reported as the surface enhanced Raman scattering (SERS) booster. DA-CDs with rich in surface functional groups was synthesized using dopamine, citric acid and ethylenediamine as precursors by a facile hydrothermal method, and can be used as the capping agents and reducing agents for the synthesis of DA-CDs/AuNPs. Due to the electromagnetic "hot spots" effect, DA-CDs/AuNPs with core-shell structure exhibited strong SERS activity. Based on the specific interaction of DA-CDs/AuNPs and fenamidone, a detection method of fenamidone was established with a low detection limit of 0.05 µg/mL. Finally, the SERS sensor was successfully applied to the detection of fenamidone in fruit with recoveries between 90.6 % and 98.7 %. The method here proposed can be reliably applied for fenamidone detection on fruits.

Comprehensive Gas Prevention and Control Technique for Mining the First Seam in Short-Distance Outburst Coal Seam Groups.

Coal and gas outbursts are a phenomenon whereby broken coal and gas suddenly erupt from the coal body into the mining space under pressure. The Diandong mining area is a group of close-range outburst coal seams in which the gas content is up to 20 m3/t and gas pressure can reach 3 MPa. Research has been conducted on engineering challenges such as advanced detection and prevention of interlayer excavation in close-range coal seam groups, improvement of gas extraction quality and efficiency in low-permeability coal seam groups, and traceability and evaluation of joint extraction of coal seam groups. Through this study, advanced detection technology with full coverage in front of the excavation working face has been constructed as well as advanced pre-extraction technology for adjacent coal seams and this coal seam in ultraclose layers. We have developed a method for achieving the standard of cross-layer fixed-point hole expansion and permeability enhancement for the first mining of coal seams in a coal seam group. A combined process of graded enhanced pre-extraction and segmented regulation and extraction was proposed, which included "fixed-point control section sealing pre-extraction of coal seam groups and secondary sealing and extraction of mining pressure relief orifice."

Continuous Motion Estimation of Knee Joint Based on a Parameter Self-Updating Mechanism Model.

Estimation of continuous motion of human joints using surface electromyography (sEMG) signals has a critical part to play in intelligent rehabilitation. Traditional methods always use sEMG signals as inputs to build regression or biomechanical models to estimate continuous joint motion variables. However, it is challenging to accurately estimate continuous joint motion in new subjects due to the non-stationarity and individual differences in sEMG signals, which greatly limits the generalisability of the method. In this paper, a continuous motion estimation model for the human knee joint with a parameter self-updating mechanism based on the fusion of particle swarm optimization (PSO) and deep belief network (DBN) is proposed. According to the original sEMG signals of different subjects, the method adaptively optimized the parameters of the DBN model and completed the optimal reconstruction of signal feature structure in high-dimensional space to achieve the optimal estimation of continuous joint motion. Extensive experiments were conducted on knee joint motions. The results suggested that the average root mean square errors (RMSEs) of the proposed method were 9.42° and 7.36°, respectively, which was better than the results obtained by common neural networks. This finding lays a foundation for the human-robot interaction (HRI) of the exoskeleton robots based on the sEMG signals.

Specific colorimetric detection of methylmercury based on peroxidase-like activity regulation of carbon dots/Au NPs nanozyme.

Methylmercury (MeHg+) is one of the common organic species of mercury, and has much higher toxicity than inorganic mercury. Based on the selective enhancement of the activity of nanozyme (NA-CDs/AuNPs) by MeHg+, a novel colorimetric nanoprobe for MeHg+ assay is proposed. The noradrenaline-based carbon dots (NA-CDs) as the reducing agent was applied to prepare the NA-CDs/AuNPs. The formation of gold amalgamation (Au@HgNPs) between nanozyme and MeHg+ allows to simultaneously accelerate the electron transfer from Au and Hg to NA-CDs and the generation of radicals (i.e. ∙OH, ∙O2- and ∙CH3). The NA-CDs/AuNPs has an outstanding anti-interference performance even in the presence of different mercury. Further density functionality theory (DFT) calculations revealed that the formation of Au@HgNPs via MeHg+ contributes to the significantly lowered activation energy, resulting in the peroxidase-like activity generation and acceleration. This leads to rapid (10 min) and specific colorimetric detection of MeHg+ with the detection limit of 0.06 µg L-1. This introduces a novel method for simple and sensitive detection of MeHg+, giving a new horizon for the assay of organometallic compounds.

Fluorescence-SERS dual-mode for sensing histamine on specific binding histamine-derivative and gold nanoparticles.

Histamine (His) is used as an indicator of seafood quality, but it can be toxic at high intakes. A fluorescence (FL)-surface-enhanced Raman scattering (SERS) dual-mode assay system has been developed for His detection. The His detection method was established based on the specific binding capacity of gold nanoparticles (AuNPs) for the FL derivative of His and o-phthalaldehyde (OPA). In this strategy, His reacted with the OPA to form a Schiff base product (O-His) along with a change in FL and SERS activities. The usual nature of AuNPs could display a significant role both enhancement of SERS and quenching of FL signals. The current investigation displayed a good selectivity toward His over all other biogenic amines. Under the optimized analytical conditions, the SERS and FL intensity of the system were linearly proportional to the His concentration in the range of 0.05-4.5 mg/L and 1-20 mg/L with a detection limit of 0.04 mg/L and 0.32 mg/L, respectively. Moreover, the proposed method was successfully applied for His determination in seafood with promising results.

Estimation of continuous elbow joint movement based on human physiological structure.

OBJECTIVE: Human intention recognition technology plays a vital role in the application of robotic exoskeletons and powered exoskeletons. However, the precise estimation of the continuous motion of each joint represents a major challenge. In the current study, we present a method for estimating continuous elbow joint movement. METHODS: We developed a novel approach for estimating the elbow joint angle based on human physiological structure. We used surface electromyography signals to analyze the biomechanical properties of the muscle and combined it with physiological structure to achieve a model for estimating continuous motion. And a genetic algorithm was used to optimize unknown parameters. RESULTS: We performed extensive trials to verify the generalizability and effectiveness of this method. The trial types included elbow joint motion with single cycle trials, typical cycle trials, gradually increasing amplitude trials, and random movement trials for handheld loads of 1.25 and 2.5 kg. The results revealed that the average root-mean-square errors ranged from 0.12 to 0.26 rad, reflecting an appropriate level of estimation accuracy. CONCLUSION: Establishing a reasonable physiological model and applying an efficient optimization algorithm enabled more accurate estimation of the joint angle. The proposed method provides a theoretical foundation for robotic exoskeletons and powered exoskeletons to understand the intentions of human continuous motion.

Mitochondria-targeted reaction-based two-photon fluorescent probe for imaging of superoxide anion in live cells and in vivo.

A newly synthesized reaction-based two-photon (TP) fluorescence imaging probe, 9-butyltriphenylphosphoniumacylamino-2,7-dibenzothiazolineflurene (MF-DBZH), composed of a superoxide anion (O2(•-)) responsive group and a mitochondria-targeted site, has been shown to have high selectivity toward mitochondrial O2(•-) fluxes. The fluorescence intensity of MF-DBZH responds proportionally to changes in O2(•-) concentrations. Moreover, MF-DBZH was proved to be insensitive toward pH changes and has high photostability. Favorable features of this probe also include convenient cell loading, easy staining of both cells and small animals, and excellent biocompibility. Most importantly, MF-DBZH gives reliable TP fluorescent signal to changes of O2(•-) levels in vivo.

Ratiometric fluorescence imaging for distinguishing chloride concentration between normal and ischemic ventricular myocytes.

We devised a new ratiometric fluorescent probe for the detection of chloride ions. This synthesized probe was applied to the ventricular myocytes to successfully realize dynamic imaging of Cl(-) concentration fluctuations during the myocardial ischemia course.

Study on the fluorescence enhancement in Lanthanum(III)-carminic acid-cetyltrimethylammonium bromide system and its analytical application.

A fluorescent enhancement system carminic acid (CA)-La3+-CTAB is found and based on this finding a new fluorimetric method for the determination of CA is developed. Under optimized conditions, the enhanced intensities of fluorescence are quantitatively in proportion to the concentrations of CA in the range of 0.01231-12.31 µg mL(-1). The detection limit is 10.92 ng mL(-1). Compared with other methods that have been reported to determine CA, this method has high sensitivity, stability and wide linear range. In addition, the luminescence mechanism indicates that the complex of La3+-CA (1:2) forms and solubilizes in CTAB micelle.

Enhancing fluorescence intensity of Ellagic acid in Borax-HCl-CTAB micelles.

Ellagic acid (C(14)H(6)O(8)), a naturally occurring phytochemical, found mainly in berries and some nuts, has anticarcinogenic and antioxidant properties. It is found that fluorescence of Ellagic acid (EA) is greatly enhanced by micelle of cetyltrimethylammonium bromide (CTAB) surfactant. Based on this effect, a sensitive proposed fluorimetric method was applied for the determination of Ellagic acid in aqueous solution. In the Borax-HCl buffer, the fluorescence intensity of Ellagic acid in the presence of CTAB is proportional to the concentration of Ellagic acid in range from 8.0×10(-10) to 4.0×10(-5) mol L(-1); and the detection limits are 3.2×10(-10) mol L(-1) and 5.9×10(-10) mol L(-1) excited at 266 nm and 388 nm, respectively. The actual samples of pomegranate rinds are simply manipulated and satisfactorily determined. The interaction mechanism studies argue that the negative EA-Borax complex is formed and solubilized in the cationic surfactant CTAB micelle in this system. The fluorescence intensity of EA enhances because the CTAB micelle provides a hydrophobic microenvironment for EA-Borax complex, which can prevent collision with water molecules and decrease the energy loss of EA-Borax complex.

[Investigation of birth state and disease spectrum in 1,434 hospitalized neonates].

OBJECTIVE: To investigate the birth state of neonates and the disease spectrum of hospitalized neonates from a primary hospital, and compare with the national data of the same period. METHODS: A retrospective investigation was carried out in 1,434 neonates born or hospitalized in this hospital from January 2005 to December 2005. RESULTS: During the investigation period, there were 1,100 neonates born in the department of obstetrics. The incidence of premature birth was 2.3%. The caesarean birth accounted for 54.2%, significantly higher than the national average (49.2%, p<0.01). The neonatal mortality was 0.2%. The incidences of antepartum hemorrhage, threatened abortion, and pregnancy infection in preterm infant' s mothers were significantly higher than those in full-term infant' s mothers. A total of 344 neonates were admitted to the department of pediatrics during the investigation period. Preterm infants accounted for 38.0% which was higher than the national average (26.2%; p<0.01). Beside preterm infants, asphyxia, respiratory distress syndrome (RDS), sepsis and intracranial hemorrhage were shown to have a significantly higher proportion than the national averages. The mortality of hospitalized neonates was 0.9%. CONCLUSIONS: The higher cesarean section rate should be controlled in our hospital. Prenatal health care and fetal monitoring should be strengthened to decrease the incidence of premature birth, RDS, sepsis and intracranial hemorrhage, thus reducing the mortality of neonates.