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.

High-molecular-weight glutenin subunits (HMW-GS) contribute to dough elasticity and bread baking quality in wheat. In this study, wheat varieties were classified based on their HMW-GS composition into three groups: 1Dx5 (5 + 10, Gaoyou 8901, Xinmai 28, Xinmai 19, Xinmai 26 and Jinbaoyin), 1Dx2 (2 + 12, Zhoumai 24, Xinmai 9 and Yumai) and 1Dx4 (4 + 12, Aikang 58). Sequence analysis showed that 1Dx-GY8901, 1Dx-XM28, 1Dx-XM19 and 1Dx-XM26 were similar to the 1Dx5 gene and clustered on the same branch, while 1Dx-AK58, 1Dx-ZM24, 1Dx-JBY, 1Dx-YM, 1Dx-XM9 and 1Dx-JBY were more similar to the 1Dx2 gene and clustered on the same branch with 1Dx.2.2. There was a mutation of Ser to Cys at position S2, for an extra Cys in the repeat regions of 1Dx-XM19, 1Dx-XM26, 1Dx-XM28 and 1Dx-GY8901. The wheat HMW-GS genes exhibited similar percentages of α-helix, extended strand, β-turn and random coil structure, with ranges of 13.33–13.59, 4.77–5.78, 7.08–9.18 and 72.3–73.94%, respectively. Sequence conservation and the composition of HMW-GS subunits were also analysed for a series of strong gluten wheat varieties, Xinmai 9 (1, 7 + 8, 2 + 12), Xinmai 19 (1, 7 + 9, 5 + 10), Xinmai 26 (1, 7 + 8, 5 + 10) and Xinmai 28 (1, 7 + 9, 5 + 10). The results of this work should facilitate future breeding efforts and provide the theoretical basis for wheat quality improvement.

Few studies have been conducted to investigate the association of kidney function decline with the trajectories of homocysteine (Hcy) over time, using repeated measurements. We aimed to investigate the association of kidney function with changes in plasma Hcy levels over time. Data were collected from the Rugao Longevity and Ageing Study. In detail, plasma Hcy and creatinine levels were measured in both waves (waves 2, 3 and 4) during the 3·5-year follow-up (n 1135). Wave 2 was regarded as the baseline survey. The estimated glomerular filtration rate (eGFR) was calculated based on creatinine. Subjects were categorised into four groups according to quartiles of eGFR at baseline. Linear mixed-effect models were used to investigate the association of eGFR with subsequent plasma Hcy levels. The mean eGFR at baseline was 90·84 (sd 11·42) ml/min per 1·73 m2. The mean plasma Hcy level was 14·09 (sd 6·82) at baseline and increased to 16·28 (sd 8·27) and 17·36 (sd 10·39) μmol/l during follow-ups. In the crude model, the interaction between time and eGFR at baseline was significant (β = −0·02, 95 % CI −0·02, −0·01, P = 0·002). After adjusting for confounding factors, a significant relationship remained (β = −0·02, 95 % CI −0·02, −0·01, P = 0·003), suggesting that kidney function decline at baseline was associated with a faster increase in Hcy levels. Kidney function decline is associated with a more pronounced increase in plasma Hcy levels. Further studies with longer follow-up periods and larger sample sizes are needed to validate our findings.

Several epidemiological studies have investigated that Na or K intakes might be associated with the metabolic syndrome (MetS). However, little evidence has evaluated the association between Na:K ratio and the MetS. In this study, we assessed the association between the dietary Na:K ratio and the MetS. The cross-sectional study was conducted among adults aged 18 years and older in Nanjing, using a multi-stage random sampling method, which resulted in a sample size of 1993 participants. Dietary Na and K intakes were assessed by 3 consecutive days of dietary recollection combined with condiments weighing method. Health-related data were obtained by standardised questionnaires, as well as physical examinations and laboratory assessments. The prevalence rate of the MetS was 36·5 % (728/1993). After adjusting for various lifestyle and dietary factors of the MetS, participants in the highest quartile of dietary Na:K ratio were at a higher risk of developing MetS (OR=1·602; 95 % CI 1·090, 2·353) compared with those in the lowest quartile. Each 1-sd increase in dietary Na:K ratio was associated with a higher risk of prevalent MetS (OR=1·166; 95 % CI: 1·018, 1·336). Among the components of the MetS, dietary Na:K ratio was positively associated with high blood pressure (quartile 3 v. quartile 1: OR=1·656; 95 % CI 1·228, 2·256) and hypertriacylglycerolaemia (quartile 4 v. quartile1: OR=1·305; 95 % CI 1·029, 1·655) in multivariate analysis. These results revealed that higher dietary Na:K ratio significantly increased the risk of the MetS in Chinese adults. Further studies are needed to verify this association.

The low-Reynolds-number flow over a multi-element airfoil (30P30N) is investigated with time-resolved particle image velocimetry (TR-PIV) and flow visualization (FV). Dominant flow structures over the main element of the multi-element airfoil are explored with the variation of angle of attack ($\unicode[STIX]{x1D6FC}$). It is of great importance that Görtler vortices are first observed with this configuration at $\unicode[STIX]{x1D6FC}=2^{\circ }{-}12^{\circ }$, which is quite different from the high-Reynolds-number cases. The characteristics of the Görtler vortices are explored to determine the origin of these unexpected flow structures. It is found that these Görtler vortices travel in the spanwise direction. Secondary counter-rotating vortices are induced beneath the main Görtler vortices. The travelling property of the Görtler vortices is utilized to determine the positions of the main Görtler vortices and the secondary counter-rotating vortices. It is observed that Görtler vortices reside above the separated shear layer originating from the leading-edge separation of the main element. The secondary counter-rotating vortices are located within the separated shear layer, as a result of the interaction between the Görtler vortices and the separated shear layer. The relative positions of the Görtler vortices, the secondary counter-rotating vortices and the separated shear layer result in a special transition scenario within the separated shear layer. The position of Görtler vortices combined with the Rayleigh discriminant indicates the mechanism that the Görtler vortices are generated by a virtual curved boundary. The travelling property of the Görtler vortices, which is different from the classical stationary Görtler vortices, can also be interpreted by this mechanism. Ultimately, modified criteria for generating Görtler vortices with a virtual curved boundary are proposed to provide references for the follow-up works.

The ultrafast dynamic process in semiconductor Ge irradiated by the femtosecond laser pulses is numerically simulated on the basis of van Driel system. It is found that with the increase of depth, the carrier density and lattice temperature decrease, while the carrier temperature first increases and then drops. The laser fluence has a great influence on the ultrafast dynamical process in Ge. As the laser fluence remains a constant value, though the overall evolution of the carrier density and lattice temperature is almost independent of pulse duration and laser intensity, increasing the laser intensity will be more effective than increasing the pulse duration in the generation of carriers. Irradiating the Ge sample by the femtosecond double pulses, the ultrafast dynamical process of semiconductor can be affected by the temporal interval between the double pulses.

Legionnaires’ disease (LD) is a globally distributed systemic infectious disease. The burden of LD in many regions is still unclear, especially in Asian countries including China. A survey of Legionella infection using real-time PCR and nested sequence-based typing (SBT) was performed in two hospitals in Shanghai, China. A total of 265 bronchoalveolar lavage fluid (BALF) specimens were collected from hospital A between January 2012 and December 2013, and 359 sputum specimens were collected from hospital B throughout 2012. A total of 71 specimens were positive for Legionella according to real-time PCR focusing on the 5S rRNA gene. Seventy of these specimens were identified as Legionella pneumophila as a result of real-time PCR amplification of the dotA gene. Results of nested SBT revealed high genetic polymorphism in these L. pneumophila and ST1 was the predominant sequence type. These data revealed that the burden of LD in China is much greater than that recognized previously, and real-time PCR may be a suitable monitoring technology for LD in large sample surveys in regions lacking the economic and technical resources to perform other methods, such as urinary antigen tests and culture methods.

Round spermatid injection (ROSI) into mammalian oocytes can result in the development of viable embryos and offspring. One current limitation to this technique is the identification of suitable round spermatids. In the current paper, round spermatids were selected from testicular cells with phase contrast microscopy (PCM) and fluorescence-activated cell sorting (FACS), and ROSI was performed in two strains of mice. The rates of fertilization, embryonic development and offspring achieved were the same in all strains. Significantly, round spermatids selected by PCM and FACS were effectively used to rescue the infertile Pten-null mouse. The current results indicate that FACS selection of round spermatids can not only provide high-purity and viable round spermatids for use in ROSI, but also has no harmful effects on the developmental capacity of subsequently fertilized embryos. It was concluded that round spermatids selected by FACS are useful for mouse strain rederivation and rescue of infertile males; ROSI should be considered as a powerful addition to the armamentarium of assisted reproduction techniques applicable in the mouse.

In this paper, we present the use of the orthogonal spline collocation method for the semi-discretization scheme of the one-dimensional coupled nonlinear Schrödinger equations. This method uses the Hermite basis functions, by which physical quantities are approximated with their values and derivatives associated with Gaussian points. The convergence rate with order and the stability of the scheme are proved. Conservation properties are shown in both theory and practice. Extensive numerical experiments are presented to validate the numerical study under consideration.

The goal of this project was to determine whether the originating strain of mouse embryonic stem (ES) cells affects the maintenance of their pluripotency under uniform culture conditions. ES cells from two strains of mice, E14 and C2J, were tested. Both ES cell lines were cultured in KOSR + 2i medium and then injected into C57BL/6J blastocysts. Our results demonstrate that this medium could support both E14 and C2J ES cells to keep their pluripotency, though E14 ES cells were found to have a higher chimeric rate than C2J ES cells. However, analysis by backcrossing revealed that C2J and E14 ES cells have the same ability for germline transmission. Our results demonstrate that ES cells derived from E14 and C2J cells have the same capacity for germline transmission when injected into C57BL/6J blastocysts; however, due to the limitation of mixed genetic background between E14 cells and host C57BL/6J embryos, C2J ES cells are preferable to E14 ES cells for use in gene-targeting and should become the cell line of choice for the generation of genetically engineered mutant mouse lines.

The maintenance and preservation of strains of mice used in biomedical research presents a unique challenge to individual investigators and research institutions. The goal of this study was to assess a comprehensive system for mouse strain conservation through a combination of natural mating, sperm cryopreservation and assisted reproductive technology. Our strategy was based on the collection and cryopreservation of fresh epididymal sperm from male mice by semi-vasectomy; these mice were then naturally mated for breeding purposes. If no satisfactory results were obtained from natural breeding, then the cryopreserved sperm were used for in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI); resultant embryos were then transferred into pseudopregnant-recipient female mice. Our results show that some semi-vasectomized mouse strains can be conserved by natural breeding, and that sterile males can be compensated for through the use of IVF and ICSI technology. As such, we believe this system is suitable for the purpose of strain conservation, allowing the continuation of natural breeding with the safeguard of assisted reproduction available.

High-pressure in situ angular dispersive x-ray diffraction study on the wurtzite-type InN nanowires has been carried out by means of the image-plate technique and diamond-anvil cell (DAC) up to about 31.8 GPa. The pressure-induced structural transition from the wurtzite to a rocksalt-type phase occurs at about 14.6 GPa, which is slightly higher than the transition pressure of InN bulk materials (∼12.1 GPa). The relative volume reduction at the transition point is close to 17.88%, and the bulk modulus B0 is determined through fitting the relative volume-pressure experimental data related to the wurtzite and rocksalt phases to the Birch–Murnaghan equation of states. Moreover, high-pressure Raman scattering for InN nanowires were also investigated in DAC at room temperature. The corresponding structural transition was confirmed by assignment of phonon modes. We calculated the mode Grüneisen parameters for the wurtzite and rocksalt phases of InN nanowires.

In this study, the influence of T5 heat treatment on tensile and fatigue behavior of hot-extruded Mg–10Gd–3Y (wt%) magnesium alloy has been investigated. High cycle fatigue tests were carried out at a stress rate (R) of −1 and a frequency of 100 Hz using hour-glass-shaped round specimens with a gauge diameter of 5.8 mm. The results show that fatigue strength (at 107 cycles) of Mg–10Gd–3Y magnesium alloy increases from 150 to 165 MPa after T5 heat treatment, i.e., the improvement of 10% in fatigue strength has been achieved. However, the crack growth resistance is lowered by T5 heat treatment. Results of microstructure observation and scanning electron microscopy-energy dispersive x-ray (SEM-EDX) analysis suggest that the fatigue strength in the Mg–10Gd–3Y magnesium alloy is determined by the threshold stress of basal slip, which is induced by solid solution hardening and precipitation hardening.

A polymerase chain reaction–enzyme-linked immunosorbent assay (PCR-ELISA) method was set up to detect Mycoplasma in live vaccines and to establish the optimal experimental conditions. According to the 16S rRNA gene sequences published in GenBank, which include Mycoplasma gallisepticum of chicken and M. hyopneumoniae, M. hyosynoviae and M. flocculare of swine (submitted nos: Mg AY744942, Mhp AE017244, Mhs AY973563 and Mf X63377), PCR primers, labelled with digoxin (Dig), and probe, labelled with biotin, were designed using the software DNAstar and Primer Premier 5.0. The system and conditions of PCR–ELISA were optimized using purified genomic DNA extracted from Mycoplasma as a template. Samples of 30 batches of Newcastle disease live vaccines (I strain), 30 batches of Newcastle disease live vaccines (La Sota strain) and 30 batches of swine fever live vaccine were tested by PCR-ELISA. Results showed that the detection rate of Mycoplasma contamination from different vaccines was higher (36.5%) with this technique than with PCR (24.4%). The PCR–ELISA appeared to be a simple, fast and reliable method for qualitative and quantitative analysis of Mycoplasma. The practical use of PCR–ELISA as a kit to detect Mycoplasma contamination in live vaccine seems very promising.