A dual-arm space robot has large potentials in on-orbit servicing. However, there exist multiple dynamic coupling effects between the two arms, each arm, and the base, bringing great challenges to the trajectory planning and dynamic control of the dual-arm space robotic system. In this paper, we propose a dynamic coupling modeling and analysis method for a dual-arm space robot. Firstly, according to the conservation principle of the linear and angular momentum, the dynamic coupling between the base and each manipulator is deduced. The dynamic coupling factor is then defined to evaluate the dynamic coupling degree. Secondly, the dynamic coupling equations between the two arms, each arm, and the base are deduced, respectively. The dynamic coupling factor is suitable not only for single-arm space robots but also for multi-arm space robot systems. Finally, the multiple coupling effects of the dual-arm space robotic system are analyzed in detail through typical cases. Simulation results verified the proposed method.

The experimental study on thermocapillary convection in liquid bridges of large Prandtl number has been carried out on Tiangong-2 in space. The purpose of these experiments is to study the oscillation instability of thermocapillary convection, and to discover and recognize the mechanism of destabilization of thermocapillary convection in the microgravity environment in space. In this paper, the geometry of a half-floating-zone liquid bridge is featured by the aspect ratio Ar and volume ratio Vr, and its influence on critical conditions of oscillatory thermocapillary convection is studied. More than 700 sets of space experiments have been finished. The critical conditions and oscillation characteristics of thermocapillary convection instability in the Ar–Vr parameter space have been fully obtained under microgravity conditions for the first time. It is found that the Ar–Vr parameter space can be divided into two regions of different critical conditions and oscillation characteristics: the region of low frequency oscillation, and the region of high frequency oscillation. More importantly, we obtain the complete configuration of these two stability neutral curves, and find that the low frequency mode is a ‘’ type curve. Based on this, we discuss the influence of heating rate on the oscillation mode. It is found that the heating rate affects the selection of critical mode, which results in a jump change of critical temperature difference. The findings of this study are helpful to better understand the critical modes and transition processes of thermocapillary convection in liquid bridges with different configurations.

Androgenetic embryonic stem (AgES) cells offer a possible tool for patient-specific pluripotent stem cells that will benefit genomic imprinting studies and clinic applications. However, the difficulty in producing androgenetic embryos and the unbalanced expression of imprinted genes make the therapeutic applicability of AgES cells uncertain. In this study, we produced androgenetic embryos by injecting two sperm into an enucleated metaphase II (MII) oocyte. By this method, 88.48% of oocytes survived after injection, and 20.24% of these developed to the blastocyst stage. We successfully generated AgES cell lines from the androgenetic embryos and assayed the expression of imprinted genes in the cell lines. We found that the morphological characteristics of AgES cells were similar to that of fertilized embryonic stem cells (fES), such as expression of key pluripotent markers, and generation of cell derivatives representing all three germ layers following in vivo and in vitro differentiation. Furthermore, activation of paternal imprinted genes was detected, H19, ASC12 and Tss3 in AgES cell activation levels were lower while other examined genes showed no significant difference to that of fES cells. Interestingly, among examined maternal imprinted genes, only Mest and Igf2 were significantly increased, while levels of other detected genes were no different to that of fES cells. These results demonstrated that activation of some paternal imprinted genes, as well as recovery of maternal imprinted genes, was present in AgES cells. We differentiated AgES cells into a beating embryoid body in vitro, and discovered that the AgES cells did not show significant higher efficiency in myocardial differentiation potential.

To determine the prevalence of Cryptosporidium in dairy cattle in Guangdong Province, South China, 1440 fecal samples were collected from 10 farms and screened for Cryptosporidium with PCR. The overall prevalence of Cryptosporidium was 4.38% (63/1440), and the infection rates in preweaned calves, postweaned calves, heifers and adults were 6.4% (19/297), 6.19% (33/533), 1.48% (4/271) and 2.06% (7/339), respectively. Three Cryptosporidium species, Cryptosporidium andersoni (n = 33), Cryptosporidium bovis (n = 22) and Cryptosporidium ryanae (n = 8) were detected by DNA sequence analysis of the 63 positive samples, and C. andersoni was identified as the most common species on the dairy cattle farms. In preweaned calves, C. bovis was the most prevalent species (9/19, 47.4%). In contrast, C. andersoni was the predominant species (19/33, 57.6%) in postweaned calves and the only species found in heifers and adults. The zoonotic species Cryptosporidium parvum was not detected in this study. Twenty-four C. andersoni isolates were successfully classified into three multilocus sequence typing (MLST) subtypes. MLST subtype A4,A4,A4,A1 was the predominant subtype, and MLST subtype A2,A5,A2,A1, previously found in sheep, was detected in cattle for the first time. A linkage disequilibrium analysis showed that the C. andersoni isolates had a clonal genetic population structure. However, further molecular studies are required to better understand the epidemiology of Cryptosporidium in Guangdong.

This study analyzed and assessed publication trends in articles on “disaster medicine,” using scientometric analysis. Data were obtained from the Web of Science Core Collection (WoSCC) of Thomson Reuters on March 27, 2017. A total of 564 publications on disaster medicine were identified. There was a mild increase in the number of articles on disaster medicine from 2008 (n=55) to 2016 (n=83). Disaster Medicine and Public Health Preparedness published the most articles, the majority of articles were published in the United States, and the leading institute was Tohoku University. F. Della Corte, M. D. Christian, and P. L. Ingrassia were the top authors on the topic, and the field of public health generated the most publications. Terms analysis indicated that emergency medicine, public health, disaster preparedness, natural disasters, medicine, and management were the research hotspots, whereas Hurricane Katrina, mechanical ventilation, occupational medicine, intensive care, and European journals represented the frontiers of disaster medicine research. Overall, our analysis revealed that disaster medicine studies are closely related to other medical fields and provides researchers and policy-makers in this area with new insight into the hotspots and dynamic directions. (Disaster Med Public Health Preparedness. 2019;13:165–172)

The discovery of the first electromagnetic counterpart to a gravitational wave signal has generated follow-up observations by over 50 facilities world-wide, ushering in the new era of multi-messenger astronomy. In this paper, we present follow-up observations of the gravitational wave event GW170817 and its electromagnetic counterpart SSS17a/DLT17ck (IAU label AT2017gfo) by 14 Australian telescopes and partner observatories as part of Australian-based and Australian-led research programs. We report early- to late-time multi-wavelength observations, including optical imaging and spectroscopy, mid-infrared imaging, radio imaging, and searches for fast radio bursts. Our optical spectra reveal that the transient source emission cooled from approximately 6 400 K to 2 100 K over a 7-d period and produced no significant optical emission lines. The spectral profiles, cooling rate, and photometric light curves are consistent with the expected outburst and subsequent processes of a binary neutron star merger. Star formation in the host galaxy probably ceased at least a Gyr ago, although there is evidence for a galaxy merger. Binary pulsars with short (100 Myr) decay times are therefore unlikely progenitors, but pulsars like PSR B1534+12 with its 2.7 Gyr coalescence time could produce such a merger. The displacement (~2.2 kpc) of the binary star system from the centre of the main galaxy is not unusual for stars in the host galaxy or stars originating in the merging galaxy, and therefore any constraints on the kick velocity imparted to the progenitor are poor.

This paper provides sufficient conditions for the nonparametric identification of the regression function $m\left( \cdot \right)$ in a regression model with an endogenous regressor x and an instrumental variable z. It has been shown that the identification of the regression function from the conditional expectation of the dependent variable on the instrument relies on the completeness of the distribution of the endogenous regressor conditional on the instrument, i.e., $f\left( {x|z} \right)$ . We show that (1) if the deviation of the conditional density $f\left( {x|{z_k}} \right)$ from a known complete sequence of functions is less than a sequence of values determined by the complete sequence in some distinct sequence $\left\{ {{z_k}:k = 1,2,3, \ldots } \right\}$ converging to ${z_0}$ , then $f\left( {x|z} \right)$ itself is complete, and (2) if the conditional density $f\left( {x|z} \right)$ can form a linearly independent sequence $\{ f( \cdot |{z_k}):k = 1,2, \ldots \}$ in some distinct sequence $\left\{ {{z_k}:k = 1,2,3, \ldots } \right\}$ converging to ${z_0}$ and its relative deviation from a known complete sequence of functions under some norm is finite then $f\left( {x|z} \right)$ itself is complete. We use these general results to provide specific sufficient conditions for completeness in three different specifications of the relationship between the endogenous regressor x and the instrumental variable $z.$

The new ternary compound of Al2Cu3Gd was prepared by melting with stoichiometric composition in an electric arc furnace. The X-ray powder diffraction data of Al2Cu3Gd have been collected by the Rigaku Smart Lab X-ray powder diffractometer. The Rietveld refinement method had been used to study the crystal structure of Al2Cu3Gd. The results showed that the Al2Cu3Gd, new compound have the hexagonal structure, space group P6/mmm (No. 191) with a = 5.1822 (1) Å, c = 4.1566 (1) Å, V = 96.67 Å3, Z = 1, and the density is 6.62 g cm−3, and the intensity ratio reference intensity ratio is 1.29.

The late Quaternary sedimentary sequence in the northwestern part of the Sichuan Basin consists of five lithological units and with increasing depth include the: Chengdu Clay; Brown Clay; Red Clay; Sandy Silt; and basal Muddy Gravel. The genesis, provenance and age of the sediments, as well as the possible presence of hiatuses within this sequence are debated. Measurements of grain-size, magnetic susceptibility, quartz content, quartz δ18O values, element composition, and Sr–Nd isotopic concentrations of samples from a typical sedimentary sequence in the area provides new insights into the genesis and history of the sequence. The new data confirm that the sediments in study site are alluvial–aeolian in origin, with basal alluvial deposits overlain by aeolian deposits. Like the uppermost Chengdu Clay, the underlying Brown Clay and Red Clay are aeolian in origin. In contrast, the Silty Sand, like the basal Muddy Gravel, is an alluvial deposit and not an aeolian deposit as previously thought. Moreover, the succession of the aeolian deposits very likely contains two significant sedimentary hiatuses. Sedimentological analysis demonstrates that the source materials for the aeolian deposits in the northwestern part of the Sichuan Basin and those on the eastern Tibetan Plateau are different. Furthermore, the loess deposits on the eastern Tibetan Plateau are derived from heterogeneous local sources.

Capacitive power transfer (CPT) technology can achieve wireless power transfer based on electric field coupling. However, practical CPT systems often have cross-coupling between coupling plates of the capacitive-coupling interface, which makes accurate system analysis and compensation design tedious and complicated. In this paper, an accurate steady-state equivalent circuit model of the capacitive-coupling interface with cross-coupling is established. The model includes a parallel input capacitor linked with a series output capacitor by an ideal transformer whose turns ratio reflects the extent of cross-coupling between the plates. Effects of coupling variation on the model are analyzed in detail. The model is used for primary and secondary tuning design to achieve the maximum power transfer of a CPT system with cross-coupling. The effectiveness of the proposed model is demonstrated by both simulations and experimental results.

Intra-uterine growth restriction (IUGR) impairs postnatal growth and skeletal muscle development in neonatal infants. This study evaluated whether dietary β-hydroxy-β-methylbutyrate Ca (HMB-Ca) supplementation during the early postnatal period could improve muscle growth in IUGR neonates using piglets as a model. A total of twelve pairs of IUGR and normal-birth-weight (NBW) male piglets with average initial weights (1·85 (sem 0·36) and 2·51 (sem 0·39) kg, respectively) were randomly allotted to groups that received milk-based diets (CON) or milk-based diets supplemented with 800 mg/kg HMB-Ca (HMB) during days 7–28 after birth. Blood and longissimus dorsi (LD) samples were collected and analysed for plasma amino acid content, fibre morphology and the expression of genes related to muscle development. The results indicate that, regardless of diet, IUGR piglets had a significantly decreased average daily weight gain (ADG) compared with that of NBW piglets (P<0·05). However, IUGR piglets fed HMB-Ca had a net weight and ADG similar to that of NBW piglets fed the CON diet. Irrespective of body weight (BW), HMB-Ca supplementation markedly increased the type II fibre cross-sectional area and the mRNA expression of mammalian target of rapamycin (mTOR), insulin-like growth factor-1 and myosin heavy-chain isoform IIb in the LD of piglets (P<0·05). Moreover, there was a significant interaction between the effects of BW and HMB on mTOR expression in the LD (P<0·05). In conclusion, HMB-Ca supplementation during the early postnatal period could improve skeletal muscle growth and maturity by accelerating fast-twitch glycolytic fibre development in piglets.

The evolution behavior of Ni2(Cr, Mo) phase with Pt2Mo-type structure in the Ni–Cr–Mo alloy with a low atomic Mo/Cr ratio subjected to a long-term thermal exposure of 100–340 h at 600 °C was investigated using transmission electron microscopy and microhardness. Results demonstrate that there is a linear relationship between major axis cube (L 3) of ordered domain and thermal exposure time (t) followed by a coarsening regime described by the Lifshitz–Slyozov–Wagner model, as well as between the aspect ratio (D) of ordered domain and thermal exposure time. The volume fraction of ordered domain increases with increasing thermal exposure time, whereas the hardening of samples decreases due to growth-coarsening of ordered domain. Prolonged thermal exposure time led to the coarsening of ordered domain by rate of (3.39 ± 0.02) × 10−30 m3/s without changing their crystallography and ordering characteristics during thermal exposure. Plastic deformation before thermal exposure do not lead to decomposition of initial Ni2(Cr, Mo) phase, but both plastic deformation and thermal exposure affect their morphology and distribution.

The ternary compound of AlCu4Y was synthesized by melting under argon atmosphere in the arc furnace. High-quality X-ray powder diffraction data of AlCu4Y have been collected using a Rigaku SmartLab X-ray powder diffractometer. The Rietveld refinement results of the X-ray diffraction pattern for the AlCu4Y compound showed that the AlCu4Y is the hexagonal structure, space-group P6/mmm (No. 191) with a = 5.0658(1) Å, c = 4.1569(1) Å, V = 92.38 Å3, Z = 1, and the density is 6.66 g cm−3, and the intensity ratio RIR is 1.96.

Alpha-lipoic acid (ALA) is known to be a natural antioxidant. The aim of the present study was to evaluate the cryoprotective effect of ALA on the motility of boar spermatozoa and its antioxidant effect on boar spermatozoa during freezing–thawing. Different concentrations (2.0, 4.0, 6.0, 8.0 or 10.0 mg/ml) of ALA were added to the extender used to freeze boar semen, and the effects on the quality and endogenous antioxidant enzyme activities of frozen–thawed spermatozoa were assessed. The results indicated that the addition of ALA to the extender resulted in a higher percentage of motile spermatozoa post-thaw (P < 0.05). The activities of superoxide dismutase, lactate dehydrogenase, glutamic-oxaloacetic transaminase and catalase improved after adding ALA to the extender (P < 0.05). Artificial insemination results showed that pregnancy rate and litter size were significantly higher at 6.0 mg/ml in the ALA group than in the control group (P < 0.05). In conclusion, ALA conferred a cryoprotective capacity to the extender used for boar semen during the process of freezing–thawing, and the optimal concentration of ALA for the frozen extender was 6.0 mg/ml.

Postnatal rapid growth by excess intake of nutrients has been associated with an increased susceptibility to diseases in neonates with intra-uterine growth restricted (IUGR). The aim of the present study was to determine whether postnatal nutritional restriction could improve intestinal development and immune function of neonates with IUGR using piglets as model. A total of twelve pairs of normal-birth weight (NBW) and IUGR piglets (7 d old) were randomly assigned to receive adequate nutrient intake or restricted nutrient intake (RNI) by artificially liquid feeding for a period of 21 d. Blood samples and intestinal tissues were collected at necropsy and were analysed for morphology, digestive enzyme activities, immune cells and expression of innate immunity-related genes. The results indicated that both IUGR and postnatal nutritional restriction delayed the growth rate during the sucking period. Irrespective of nutrient intake, piglets with IUGR had a significantly lower villous height and crypt depth in the ileum than the NBW piglets. Moreover, IUGR decreased alkaline phosphatase activity while enhanced lactase activity in the jejunum and mRNA expressions of Toll-like receptor 9 (TLR-9) and DNA methyltransferase 1 (DNMT1) in the ileum of piglets. Irrespective of body weight, RNI significantly decreased the number and/or percentage of peripheral leucocytes, lymphocytes and monocytes of piglets, whereas the percentage of neutrophils and the ratio of CD4+ to CD8+ were increased. Furthermore, RNI markedly enhanced the mRNA expression of TLR-9 and DNMT1, but decreased the expression of NOD2 and TRAF-6 in the ileum of piglets. In summary, postnatal nutritional restriction led to abnormal cellular and innate immune response, as well as delayed the growth and intestinal development of IUGR piglets.