Dietary antioxidant indices (DAI) may be potentially associated with relative telomere length (RTL) of leucocytes. This study aimed to investigate the relationship between DAI and RTL. A cross-sectional study involving 1656 participants was conducted. A generalised linear regression model and a restricted cubic spline model were used to assess the correlation of DAI and its components with RTL. Generalised linear regression analysis revealed that DAI (β = 0·005, P = 0·002) and the intake of its constituents vitamin C (β = 0·043, P = 0·027), vitamin E (β = 0·088, P < 0·001), Se (β = 0·075, P = 0·003), and Zn (β = 0·075, P = 0·023) were significantly and positively correlated with RTL. Sex-stratified analysis showed that DAI (β = 0·006, P = 0·005) and its constituents vitamin E (β = 0·083, P = 0·012), Se (β = 0·093, P = 0·006), and Zn (β = 0·092, P = 0·034) were significantly and positively correlated with RTL among females. Meanwhile, among males, only vitamin E intake (β = 0·089, P = 0·013) was significantly and positively associated with RTL. Restricted cubic spline analysis revealed linear positive associations between DAI and its constituents’ (vitamin E, Se and Zn) intake and RTL in the total population. Sex-stratified analysis revealed a linear positive correlation between DAI and its constituents’ (vitamin E, Se and Zn) intake and RTL in females. Our study found a significant positive correlation between DAI and RTL, with sex differences.

Instrument delivery is critical part in vascular intervention surgery. Due to the soft-body structure of instruments, the relationship between manipulation commands and instrument motion is non-linear, making instrument delivery challenging and time-consuming. Reinforcement learning has the potential to learn manipulation skills and automate instrument delivery with enhanced success rates and reduced workload of physicians. However, due to the sample inefficiency when using high-dimensional images, existing reinforcement learning algorithms are limited on realistic vascular robotic systems. To alleviate this problem, this paper proposes discrete soft actor-critic with auto-encoder (DSAC-AE) that augments SAC-discrete with an auxiliary reconstruction task. The algorithm is applied with distributed sample collection and parameter update in a robot-assisted preclinical environment. Experimental results indicate that guidewire delivery can be automatically implemented after 50k sampling steps in less than 15 h, demonstrating the proposed algorithm has the great potential to learn manipulation skill for vascular robotic systems.

Chronic inflammation exerts pleiotropic effects in the aetiology and progression of chronic obstructive pulmonary disease (COPD). Glucosamine is widely used in many countries and may have anti-inflammatory properties. We aimed to prospectively evaluate the association of regular glucosamine use with incident COPD risk and explore whether such association could be modified by smoking in the UK Biobank cohort, which recruited more than half a million participants aged 40–69 years from across the UK between 2006 and 2010. Cox proportional hazards models with adjustment for potential confounding factors were used to calculate hazard ratios (HR) as well as 95 % CI for the risk of incident COPD. During a median follow-up of 8·96 years (interquartile range 8·29–9·53 years), 9016 new-onset events of COPD were documented. We found that the regular use of glucosamine was associated with a significantly lower risk of incident COPD with multivariable adjusted HR of 0·80 (95 % CI, 0·75, 0·85; P < 0·001). When subgroup analyses were performed by smoking status, the adjusted HR for the association of regular glucosamine use with incident COPD were 0·84 (0·73, 0·96), 0·84 (0·77, 0·92) and 0·71 (0·62, 0·80) among never smokers, former smokers and current smokers, respectively. No significant interaction was observed between glucosamine use and smoking status (P for interaction = 0·078). Incident COPD could be reduced by 14 % to 84 % through a combination of regular glucosamine use and smoking cessation.

A novel solid-clad-by-liquid method was developed to form a 10-m long by 10-mm wide by 80-μm thick Ni–5 at.% W/Ni–9.3 at.% W/Ni–5 at.% W composite tape. Three deformation routes (cold rolling, cold rolling with intermediate annealing, and cold rolling combined with warm rolling) have been investigated in short Ni–5 at.% W/Ni–9.3 at.% W/Ni–5 at.% W composite substrate. To optimize the dynamic continuous annealing parameters for the long composite substrates, air-cooled and furnace-cooled annealing procedures were compared in short Ni–5 at.% W/Ni–9.3 at.% W/Ni–5 at.% W composite substrates. Improved cube texture of 98.7% in a 10-m long by 10-mm wide by 80-μm thick Ni–5 at.% W/Ni–9.3 at.% W/Ni–5 at.% W composite substrate was achieved via warm rolling deformation at 550 °C and two-step dynamic continuous annealing (750 °C for 1 h followed by 1200 °C for 1 h). The yield strength, Curie temperature, and saturation magnetization of 176 MPa, 324 K, and 18 emu/g, respectively, were obtained.

Gradual fault detection is always an important issue in integrated navigation systems, and the gradual fault is the most difficult fault to detect. To detect gradual faults in a timely and precise manner in integrated navigation systems, the statistical concepts of the normalised residual mean and the sum of absolute residuals are introduced according to the characteristics of gradual system failure in this paper. The applicability of the improved residual χ2 detection method is discussed. Then, the gradual fault detection program based on the improved residual χ2 detection method is designed with the criterion of normalised residual mean and the sum of absolute residual. The simulation results and vehicle tests show that: 1) The residual of the failed sub-system can be calculated accurately with the improved residual χ2 detection method, which has strong applicability in gradual fault detection; 2) The gradual fault can be detected in a short time by using the normalised residual mean and the sum of absolute residual.

High speed framing camera (HSFC) could be used to capture the image of the electron beams generated by the intense electron-beam accelerator (IEBA), and it is useful to visualize the evolution of discharging and plasma generation phenomenon. So an overview of the application of HSFC on the IEBA is presented. First, we introduce the synchronization problem of HSFC and IEBA, and a synchronization trigger system which could provide a trigger signal with rise time of 17 ns and amplitude of about 5 V is presented. Second, an imaging system based on IEBA, HSFC, and the synchronization trigger system is developed, and it can be used to image the developmental process of plasma in the output vacuum chamber of IEBA and to measure the electrical parameter of IEBA and electrical trigger signal in real time. Furthermore, the imaging system is used to investigate the developmental process of the electron beam of the A-K gap in vacuum under 180 nanosecond quasi-square pulses. It is obtained that the short A-K gap is closed prematurely under long pulse operation with plasma expansion velocity of about 6.25 cm/µs and the light emission in the A-K gap region has the characteristics of “re-ignition” with light duration time about 3800 ns. At last, the discharging process of surface flashover channel of poly-methyl methacrylate (PMMA) insulator with gap spacing of 170 mm in vacuum under nanosecond quasi-square pulses is studied by the imaging system, and the change of luminosity is analyzed during the surface flashover process.

As the development of the pulsed power technology, high voltage pulse transformer (HVPT) is usually used instead of Marx generator as a charging device for the pulse forming line (PFL) of intense electron-beam accelerator (IEBA), and which make the IEBA compact. However, during the operation of the IEBA, the HVPT may be destroyed for the failure of electrical insulation and the over-voltage. So in this paper, the output voltage characteristics of IEBA, characteristics of the voltage at the output terminal of HVPT at four kinds of load conditions are analyzed, including load matching, load short, load open, and surface flashover in the vacuum chamber. It is found that load short, load open, and surface flashover in vacuum chamber will affect the voltage at the output terminal of HVPT, and an oscillation wave could be formed, which affect the electrical insulation of HVPT and decrease the lifetime of HVPT. Meanwhile, the waveform of the load voltage is also modified, especially at the conditions of load open and surface flashover in vacuum chamber. When the load is open, the amplitude of the output main pulse of IEBA is twice the charging voltage of BPFL. However, the amplitude of the output pulse of IEBA is modified by the voltage at the output terminal of HVPT, and the resistance of main switch channel has a great effect on the amplitude of the load voltage. When surface flashover occurs in the vacuum chamber, the pulse duration of the output voltage will be decreased. So, during the operation of IEBA, load short, load open and surface flashover in vacuum chamber should be avoided.

The Blumlein pulse forming line (BPFL) consisting of an inner coaxial pulse forming line (PFL) and an outer coaxial PFL is widely used in the field of pulsed power, especially for intense electron-beam accelerators (IEBA). The output voltage waveform determines the quality and characteristics of the output beam current of the IEBA. Comparing with the conventional BPFL, an IEBA based on a strip spiral type BPFL can increase the duration of the output voltage in the same geometrical volume. However, for the spiral type BPFL, the voltage waveform on a matched load may be distorted, which influences the electron-beam quality. In this paper, the output waveform of an IEBA based on strip spiral BPFL is analyzed. It is found that there is fluctuation on the flattop of the main pulse, and the flatness is increased with the increment of the output voltage. According to the time integrated pictures of the cathode holder during the operation of the IEBA, the electron emission of the cathode holder is one of the reasons to cause the variance of the flatness. Furthermore, the distribution of the current density of spiral middle cylinder of the BPFL is calculated by using electromagnetic simulation software, and it is obtained that the current density is not uniform, and which leads to the nonuniformity of the impedance of BPFL. Meanwhile, when the nonuniformity of the BPFL is taken into account, the operation of the whole accelerator is simulated using a circuit-simulation code called PSpice. It is obtained that the nonuniformity of the BPFL influences the flatness of the output voltage waveform. In order to get an ideal square pulse voltage waveform and to improve the electron beam quality of such an accelerator, the uniformity of the spiral middle cylinder should be improved and the electron emission of the cathode holder should be avoided. The theoretical analysis and simulated output voltage waveform shows reasonable agreement with that of the experimental results.

We conduct first-principles total-energy density functional calculations to study the interaction of H2 on ZnO surfaces. Four surface models of Zn-terminated (0001)-, O-terminated (0001)-, , and oriented ZnO planes in the presence of H2 are evaluated. The relative stability of four different surface models is examined as a function of the chemical potentials of oxygen and hydrogen. We find that only surfaces of O-terminated (0001)-oriented ZnO models exhibit active sites for the dissociation of H2, which in turn enables the formation of water from dissociative chemisorption of 2H on the O-terminated ZnO(0001) surface. The surface energy of O-terminated ZnO(0001) surface in the presence of water was found to be negative under the O-rich and H-rich condition. The findings agree with the experimental observations that ZnO epitaxial layers are easily etched by hydrogen at typical growth temperatures.

A pair of degenerate primers was designed based on a conserved domain of GA 20-oxidase reported in other plants. The full-length (1179 bp) carnation (Dianthus caryophyllus L. cv. Master) GA 20-oxidase cDNA (named Dc20ox) was cloned by reverse transcriptase-polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends (RACE). BLAST analysis revealed that the deduced amino acid sequence had high homology (66–75%) with the GA 20-oxidase sequences from other plants. An RNAi vector (pART400) was constructed from a 400 bp fragment representing a highly conserved region of GA 20-oxidase.

The manipulator with a large degree of redundancy is useful for realizing multiple tasks such as maneuvering the robotic arms in the constrained workspace, e.g. the task of maneuvering the end-effector of the manipulator along a pre-specified path into a window. This paper presents an on-line technique based on a posture generation rule to compute a null-space joint velocity vector in a singularity-robust redundancy resolution method. This rule suggests that the end of each link has to track an implicit trajectory that is indirectly resulted from the constraint imposed on tracking motion of the end-effector. A proper posture can be determined by sequentially optimizing an objective function integrating multiple criteria of the orientation of each link from the end-effector toward the base link as the secondary task for redundancy resolution, by assuming one end of the link is clamped. The criteria flexibly incorporate obstacle avoidance, joint limits, preference of posture in tracking, and connection of posture to realize a compromise between the primary and secondary tasks. Furthermore, computational demanding of the posture is reduced due to the sequential link-by-link computation feature. Simulations show the effectiveness and flexibility of the proposed method in generating proper postures for the collision avoidance and the joint limits as a singularity-robust null-space projection vector in maneuvering redundant robots within constrained workspaces.

We studied the intraspecific interactions among oophagous Chirixalus eiffingeri tadpoles that occupied the same water-filled bamboo stumps at Chitou, Taiwan. We monitored the growth of newly-hatched tadpoles in unoccupied and occupied bamboo stumps in the field where the latter contained large tadpoles that hatched from earlier clutches. The growth of the small, late-hatching tadpoles in occupied nests was suppressed by the presence of large, early-hatching tadpoles. However, small tadpoles that were physically separated from large tadpoles in a perforated container grew at about the same rate as small tadpoles living in pools without large tadpoles. Thus, the slower growth of the late-hatching tadpoles was probably caused by behavioural interference competition with the early-hatching tadpoles. In the laboratory, we kept large and small tadpoles together in containers and did not feed them for 6 days. The large tadpoles did not cannibalize the small tadpoles. Although large tadpoles may scavenge dead tadpoles, the effects of scavenging on growth were negligible. Interactions among cohabiting C. eiffingeri tadpoles are similar to those among the oophagous tadpoles of several hylid species that use phytotelmata. Results suggest that behavioural interference competition is the principal type of intraspecific interactions among the oophagous, non-predatory tadpoles of hylid and rhacophorid frogs.