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The follow-up timing observations were carried out for 24 pulsars discovered with the Five-hundred-meter Aperture Spherical radio Telescope (FAST) in Commensal Radio Astronomy FAST Survey. We report their phase-connected timing ephemeris, polarization pulse profiles, and Faraday rotation measurements. With their spin periods spanning from 2.995 ms to 4.34 s, their period derivatives were determined to spread between 7.996(8) × 10−21 and 9.83(3) × 10−15 s s−1, which imply that they have characteristic ages from 1.97 × 106 to 5.93 × 109 yr. It is inferred that PSRs J0211+4235 and J0518+2431 are beyond the ‘traditional death line’. PSR J0211+4235 is beyond the ‘death valley’. The death line model of Zhang et al. also cannot explain the radio presence of PSR J0211+4235. This suggests that radiation theory needs to be improved. Besides, ten of the 22 canonical pulsars show nulling phenomena. Moreover, PSR J1617+1123 exhibits variation of emission and J0540+4542 shows subpulse drifting. The DM of five pulsars is larger than the estimated by the YMW16 electron density model, which could suggest that electron density models need updates for higher Galactic latitude regions. PSRs J0447+2447 and J1928−0548 are isolated millisecond pulsars. With their flux densities spanning from 5(1)–553(106) μJy, some of these new pulsars found by FAST are distant, dim, and low-$\dot{E}$ ones and are suitable for testing pulsar emission theories.

We report the phase-connected timing ephemeris, polarization pulse profiles, Faraday rotation measurements, and Rotating-Vector-Model (RVM) fitting results of 12 millisecond pulsars (MSPs) discovered with the Five-hundred-meter Aperture Spherical radio Telescope (FAST) in the Commensal Radio Astronomy FAST survey (CRAFTS). The timing campaigns were carried out with FAST and Arecibo over 3 yr. 11 of the 12 pulsars are in neutron star–white dwarf binary systems, with orbital periods between 2.4 and 100 d. 10 of them have spin periods, companion masses, and orbital eccentricities that are consistent with the theoretical expectations for MSP–Helium white dwarf (He WD) systems. The last binary pulsar (PSR J1912−0952) has a significantly smaller spin frequency and a smaller companion mass, the latter could be caused by a low orbital inclination for the system. Its orbital period of 29 d is well within the range of orbital periods where some MSP–He WD systems have shown anomalous eccentricities, however, the eccentricity of PSR J1912−0952 is typical of what one finds for the remaining MSP–He WD systems.

Scalable quantum computing can become a reality with error correction, provided coherent qubits can be constructed in large arrays. The key premise is that physical errors can remain both small and sufficiently uncorrelated as devices scale, so that logical error rates can be exponentially suppressed. However, energetic impacts from cosmic rays and latent radioactivity violate both of these assumptions. An impinging particle ionizes the substrate, radiating high energy phonons that induce a burst of quasiparticles, destroying qubit coherence throughout the device. High-energy radiation has been identified as a source of error in pilot superconducting quantum devices, but lacking a measurement technique able to resolve a single event in detail, the effect on large scale algorithms and error correction in particular remains an open question. Elucidating the physics involved requires operating large numbers of qubits at the same rapid timescales as in error correction, exposing the event's evolution in time and spread in space. Here, we directly observe high-energy rays impacting a large-scale quantum processor. We introduce a rapid space and time-multiplexed measurement method and identify large bursts of quasiparticles that simultaneously and severely limit the energy coherence of all qubits, causing chip-wide failure. We track the events from their initial localised impact to high error rates across the chip. Our results provide direct insights into the scale and dynamics of these damaging error bursts in large-scale devices, and highlight the necessity of mitigation to enable quantum computing to scale.

Quantum many-body systems display rich phase structure in their low-temperature equilibrium states1. However, much of nature is not in thermal equilibrium. Remarkably, it was recently predicted that out-of-equilibrium systems can exhibit novel dynamical phases2–8 that may otherwise be forbidden by equilibrium thermodynamics, a paradigmatic example being the discrete time crystal (DTC)7,9–15. Concretely, dynamical phases can be defined in periodically driven many-body-localized (MBL) systems via the concept of eigenstate order7,16,17. In eigenstate-ordered MBL phases, the entire many-body spectrum exhibits quantum correlations and long-range order, with characteristic signatures in late-time dynamics from all initial states. It is, however, challenging to experimentally distinguish such stable phases from transient phenomena, or from regimes in which the dynamics of a few select states can mask typical behaviour. Here we implement tunable controlled-phase (CPHASE) gates on an array of superconducting qubits to experimentally observe an MBL-DTC and demonstrate its characteristic spatiotemporal response for generic initial states7,9,10. Our work employs a time-reversal protocol to quantify the impact of external decoherence, and leverages quantum typicality to circumvent the exponential cost of densely sampling the eigenspectrum. Furthermore, we locate the phase transition out of the DTC with an experimental finite-size analysis. These results establish a scalable approach to studying non-equilibrium phases of matter on quantum processors., A study establishes a scalable approach to engineer and characterize a many-body-localized discrete time crystal phase on a superconducting quantum processor.

Nuclear spins in the solid state are both a cause of decoherence and a valuable resource for spin qubits. In this work, we demonstrate control of isolated 29Si nuclear spins in silicon carbide (SiC) to create an entangled state between an optically active divacancy spin and a strongly coupled nuclear register. We then show how isotopic engineering of SiC unlocks control of single weakly coupled nuclear spins and present an ab initio method to predict the optimal isotopic fraction that maximizes the number of usable nuclear memories. We bolster these results by reporting high-fidelity electron spin control (F = 99.984(1)%), alongside extended coherence times (Hahn-echo T2 = 2.3 ms, dynamical decoupling T2DD > 14.5 ms), and a >40-fold increase in Ramsey spin dephasing time (T2*) from isotopic purification. Overall, this work underlines the importance of controlling the nuclear environment in solid-state systems and links single photon emitters with nuclear registers in an industrially scalable material. Isotope engineering of silicon carbide leads to control of nuclear spins associated with single divacancy centres and extended electron spin coherence.

We present the first measurement of pulse scattering close to the eclipse region of PSR B1957+20, which is in a compact binary system with a low-mass star. We measured pulse scattering time-scales up to 0.2 ms close to the eclipse and showed that it scales with the dispersion measure (DM) excess roughly as $\tau\propto\Delta{\rm DM}^{2}$. Our observations provide the first evidence of strong scattering due to multi-path propagation effects in the eclipsing material. We show that Kolmogorov turbulence in the eclipsing material with an inner scale of $\sim100$ m and an outer scale of the size of the eclipse region can naturally explain the observation. Our results show that the eclipsing material in such systems can be highly turbulent and suggest that scattering is one of the main eclipsing mechanisms at around 1.4 GHz., Comment: 8 pages, 4 figures, MNRAS accepted

Inherent symmetry of a quantum system may protect its otherwise fragile states. Leveraging such protection requires testing its robustness against uncontrolled environmental interactions. Using 47 superconducting qubits, we implement the one-dimensional kicked Ising model, which exhibits nonlocal Majorana edge modes (MEMs) with ℤ 2 parity symmetry. We find that any multiqubit Pauli operator overlapping with the MEMs exhibits a uniform late-time decay rate comparable to single-qubit relaxation rates, irrespective of its size or composition. This characteristic allows us to accurately reconstruct the exponentially localized spatial profiles of the MEMs. Furthermore, the MEMs are found to be resilient against certain symmetry-breaking noise owing to a prethermalization mechanism. Our work elucidates the complex interplay between noise and symmetry-protected edge modes in a solid-state environment.

Spin defects in silicon carbide have exceptional electron spin coherence with a near-infrared spin-photon interface in a material amenable to modern semiconductor fabrication. Leveraging these advantages, we successfully integrate highly coherent single neutral divacancy spins in commercially available p-i-n structures and fabricate diodes to modulate the local electrical environment of the defects. These devices enable deterministic charge state control and broad Stark shift tuning exceeding 850 GHz. Surprisingly, we show that charge depletion results in a narrowing of the optical linewidths by over 50 fold, approaching the lifetime limit. These results demonstrate a method for mitigating the ubiquitous problem of spectral diffusion in solid-state emitters by engineering the electrical environment while utilizing classical semiconductor devices to control scalable spin-based quantum systems., 20 pages, 5 figures

Optically addressable paramagnetic defects in wide-band-gap semiconductors are promising platforms for quantum communications and sensing. The presence of avoided crossings between the electronic levels of these defects can substantially alter their quantum dynamics and be both detrimental and beneficial for quantum information applications. Avoided crossings give rise to clock transitions, which can significantly improve protection from magnetic noise and favorably increase coherence time. However, the reduced coupling between electronic and nuclear spins at an avoided crossing may be detrimental to applications where nuclear spins act as quantum memories. Here we present a combined theoretical and experimental study of the quantum dynamics of paramagnetic defects interacting with a nuclear spin bath at avoided crossings. We develop a computational approach based on a generalization of the cluster expansion technique, which can account for processes beyond pure dephasing and describe the dynamics of any solid-state spin-qubits near avoided crossings. Using this approach and experimental validation, we determine the change in nature and source of noise at avoided crossings for divacancies in SiC. We find that we can condition the clock transition of the divacancies in SiC on multiple adjacent nuclear spins states. In our experiments, we demonstrate that one can suppress the effects of fluctuating charge impurities with depletion techniques, leading to an increased coherence time at clock transition, limited purely by magnetic noise. Combined with ab-initio predictions of spin Hamiltonian parameters, the proposed theoretical approach paves the way to designing the coherence properties of spin qubits from first principles., Comment: 29 pages, 7 figures

This study investigated the effects of organic zinc (Zn) supplementation in early-lactation dairy cows on Zn content and distribution in raw milk and mozzarella cheese. Thirty-four multiparous dairy cows in early lactation were randomly assigned to 2 groups: basal diet (control; CON) and basal diet supplemented with a Zn AA complex (CZ). After feeding the diets for 8 wk, raw milk was collected for manufacturing mozzarella cheese. Total Zn content and Zn distribution in raw milk and cheese were determined by atomic absorption spectrophotometry. Results showed that milk fat content was significantly increased in the CZ group compared with the CON group. No significant differences in fat, protein, and moisture contents of cheese were observed between the 2 groups. Zinc contents in milk (4.25 vs. 3.85 mg/L) and cheese (38.65 vs. 27.20 mg/kg) were significantly higher in the CZ group than in the CON group. Little Zn was lost in stretch water (0.04 mg/L) and brine (0.01 mg/L) during the cheese-making process. Most of the Zn was detected in casein (87.3% vs. 88.4%) of the raw milk, and then in the whey (10.6% vs. 9.88%) and fat (2.07% vs. 1.77%). Organic Zn supplementation in early-lactation cows increased Zn content in raw milk and mozzarella cheese, and Zn remained stable during cheese making.

The study of the electrical properties of materials at cryogenic temperature is significant for the design of insulation structures of superconducting equipment. Here, epoxy resin was combined with a small amount of KH650 modified SiC nanoparticles. When the dosage of SiC nanoparticles increased from 0.1% to 0.3%, the DC breakdown strength of the composite increase from 83.93 kV/mm to 97.51 kV/mm at room temperature and from 90 kV/mm to 120 kV/mm at 77 K. Furthermore, we used differential scanning calorimeter (DSC) and dynamic thermomechanical analysis (DMA) to analyze the effect of low-content SiC nanoparticles on the thermal behavior of epoxy resin.

We report on the pulse-to-pulse energy distribution and longitude-resolved modulation properties of PSR J1631+1252 discovered by the Five-hundred-meter Aperture Spherical radio Telescope. Our analysis made use of the data acquired at 1250 MHz from the follow-up timing observations that lasted over a year. PSR J1631+1252 has a rotational period of ∼0.310 s, and a dispersion measure of ∼32.73 pc cm−3. The energy distribution is well described by a lognormal distribution, the parameters of which do not vary with time. We show that large modulation occurs across the bridge emission of the pulse profile, with sporadic bright bursts at the leading emission region. The fluctuation spectral analysis reveals the existence of subpulse drifting in the leading component with vertical spacing between the drift bands of 3.28 ± 0.08 pulse periods between consecutive drift bands. Possible physical mechanisms for subpulse drifting are discussed.

A promising approach to study condensed-matter systems is to simulate them on an engineered quantum platform

Background Many CpGs become hyper or hypo-methylated with age. Multiple methods have been developed by Horvath et al. to estimate DNA methylation (DNAm) age including Pan-tissue, Skin & Blood, PhenoAge, and GrimAge. Pan-tissue and Skin & Blood try to estimate chronological age in the normal population whereas PhenoAge and GrimAge use surrogate markers associated with mortality to estimate biological age and its departure from chronological age. Here, we applied Horvath’s four methods to calculate and compare DNAm age in 499 subjects with type 1 diabetes (T1D) from the Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications (DCCT/EDIC) study using DNAm data measured by Illumina EPIC array in the whole blood. Association of the four DNAm ages with development of diabetic complications including cardiovascular diseases (CVD), nephropathy, retinopathy, and neuropathy, and their risk factors were investigated. Results Pan-tissue and GrimAge were higher whereas Skin & Blood and PhenoAge were lower than chronological age (p < 0.0001). DNAm age was not associated with the risk of CVD or retinopathy over 18–20 years after DNAm measurement. However, higher PhenoAge (β = 0.023, p = 0.007) and GrimAge (β = 0.029, p = 0.002) were associated with higher albumin excretion rate (AER), an indicator of diabetic renal disease, measured over time. GrimAge was also associated with development of both diabetic peripheral neuropathy (OR = 1.07, p = 9.24E−3) and cardiovascular autonomic neuropathy (OR = 1.06, p = 0.011). Both HbA1c (β = 0.38, p = 0.026) and T1D duration (β = 0.01, p = 0.043) were associated with higher PhenoAge. Employment (β = − 1.99, p = 0.045) and leisure time (β = − 0.81, p = 0.022) physical activity were associated with lower Pan-tissue and Skin & Blood, respectively. BMI (β = 0.09, p = 0.048) and current smoking (β = 7.13, p = 9.03E−50) were positively associated with Skin & Blood and GrimAge, respectively. Blood pressure, lipid levels, pulse rate, and alcohol consumption were not associated with DNAm age regardless of the method used. Conclusions Various methods of measuring DNAm age are sub-optimal in detecting people at higher risk of developing diabetic complications although some work better than the others.

Decoherence largely limits the physical realization of qubits and its mitigation is critical to quantum science. Here, we construct a robust qubit embedded in a decoherence-protected subspace, obtained by hybridizing an applied microwave drive with the ground-state electron spin of a silicon carbide divacancy defect. The qubit is protected from magnetic, electric, and temperature fluctuations, which account for nearly all relevant decoherence channels in the solid state. This culminates in an increase of the qubit's inhomogeneous dephasing time by over four orders of magnitude (to > 22 milliseconds), while its Hahn-echo coherence time approaches 64 milliseconds. Requiring few key platform-independent components, this result suggests that substantial coherence improvements can be achieved in a wide selection of quantum architectures., 12 pages, 4 figures

Full list of authors: Lin, L.; Zhang, C. F.; Wang, P.; Gao, H.; Guan, X.; Han, J. L.; Jiang, J. C.; Jiang, P.; Lee, K. J.; Li, D.; Men, Y. P.; Miao, C. C.; Niu, C. H.; Niu, J. R.; Sun, C.; Wang, B. J.; Wang, Z. L.; Xu, H.; Xu, J. L.; Xu, J. W.; Yang, Y. H.; Yang, Y. P.; Yu, W.; Zhang, B.; Zhang, B. -B.; Zhou, D. J.; Zhu, W. W.; Castro-Tirado, A. J.; Dai, Z. G.; Ge, M. Y.; Hu, Y. D.; Li, C. K.; Li, Y.; Li, Z.; Liang, E. W.; Jia, S. M.; Querel, R.; Shao, L.; Wang, F. Y.; Wang, X. G.; Wu, X. F.; Xiong, S. L.; Xu, R. X.; Yang, Y. -S.; Zhang, G. Q.; Zhang, S. N.; Zheng, T. C.; Zou, J. -H., Fast radio bursts (FRBs) are millisecond-duration radio transients of unknown physical origin observed at extragalactic distances1–3. It has long been speculated that magnetars are the engine powering repeating bursts from FRB sources4–13, but no convincing evidence has been collected so far14. Recently, the Galactic magnetar SRG 1935+2154 entered an active phase by emitting intense soft γ-ray bursts15. One FRB-like event with two peaks (FRB 200428) and a luminosity slightly lower than the faintest extragalactic FRBs was detected from the source, in association with a soft γ-ray/hard-X-ray flare18–21. Here we report an eight-hour targeted radio observational campaign comprising four sessions and assisted by multi-wavelength (optical and hard-X-ray) data. During the third session, 29 soft-γ-ray repeater (SGR) bursts were detected in γ-ray energies. Throughout the observing period, we detected no single dispersed pulsed emission coincident with the arrivals of SGR bursts, but unfortunately we were not observing when the FRB was detected. The non-detection places a fluence upper limit that is eight orders of magnitude lower than the fluence of FRB 200428. Our results suggest that FRB–SGR burst associations are rare. FRBs may be highly relativistic and geometrically beamed, or FRB-like events associated with SGR bursts may have narrow spectra and characteristic frequencies outside the observed band. It is also possible that the physical conditions required to achieve coherent radiation in SGR bursts are difficult to satisfy, and that only under extreme conditions could an FRB be associated with an SGR burst. © 2020, The Author(s), under exclusive licence to Springer Nature Limited., This work is supported by the Natural Science Foundation of China (grants 11988101, 11673002, 11703002, 11543004, 11722324, 11690024, 11633001, 11920101003, 11833003, 11722324, 11633001, 11690024, 11573014, 11725314, 11690024, 11743002, 11873067, 11533003, 11673006, U1938201, 11725313, 11721303, 1172130, U15311243, U1831207, U1838201, U1838202, U1838113, U1938109), National Key Research and Development Programs of China (grants 2018YFA0404204, 2017YFA0402600), the Program for Innovative Talents and Entrepreneur in Jiangsu, the KIAA-CAS Fellowship, the China Postdoctoral Science Foundation (grants 2018M631242, 2016YFA0400800, 2018YFA0400802, E01S11BQ10, XDB23010200,XDB2304040, QYZDY-SSW-SLH008), the International Partnership Program of Chinese Academy of Sciences (grant number 114A11KYSB20160008), the Cultivation Project for FAST Scientific Payoff and Research Achievement of CAMS-CAS, the Max-Planck Partner Group, the Spanish Science Ministry “Centro de Excelencia Severo Ochoa” Program (grant SEV-2017-0709), the Junta de Andalucía (Project P07-TIC-03094) and the Spanish Ministry Projects AYA2012-39727-C03-01, AYA2015-71718R and PID2019-109974RB-I00. We thank E. Fernández-García (IAA-CSIC), I. M. Carrasco-García and C. Pérez del Pulgar (UMA) and the rest of the BOOTES Team for making the reported BOOTES Network observations possible. This work made use of data from FAST—a Chinese national mega-science facility, built and operated by the National Astronomical Observatories, Chinese Academy of Sciences. We also acknowledge the use of public data from the Fermi Science Support Center (FSSC).

Perylene diimide derivatives (PDIs) with different substituents in the bay positions (Un-PDI, DFPDI and THBPDI) were chosen in this report to investigate the effect of potential on the reduction of PDIs through base (hydrazine, 1,2-ethanediamine and triethylamine)-driven keto-enol anion tautomerism. The reduction potentials (PDI/PDI•–) of these compounds determined via cyclic voltammetry are –0.51, ‒0.34, and –0.098 V for Un-PDI, DFPDI, and THBPDI, respectively. The reduction of Un-PDI, DFPDI and THBPDI by hydrazine can produce corresponding radical anions and dianions, but the volume of hydrazine added at which the radicals started to appear is different and depends on their reduction potential. The similar phenomenon was observed using 1,2-ethylenediamine and triethylamine. However, only the radical anion was obtained even in a large excess of 1,2-ethanediamine or triethylamine. Moreover, the reduction of these PDIs with different bases added in the same amount was investigated, and the correlation with their basicity was shown.

We report on an unusually bright observation of PSR J1720−0533 using the Five-hundred-meter Aperture Spherical radio Telescope (FAST). The pulsar is in a black widow system that was discovered by the Commensal Radio Astronomy FAST Survey (CRAFTS). By coincidence, a bright scintillation maximum was simultaneous with the eclipse in our observation, which allowed for precise measurements of flux density variations, as well as dispersion measure (DM) and polarization. We found that there are quasi-periodic pulse emission variations with a modulation period of ∼22 s during the ingress of the eclipse, which could be caused by plasma lensing. No such periodic modulation was found during the egress of the eclipse. The linear polarization of the pulsar disappears before the eclipse, even before there is a visually obvious change in DM. We also found that the pulse scattering may play an important role in the eclipse of PSR J1720−0533.

Taxus yunnanensis,which is an endangered tree that is considered valuable because it contains the effective natural anticancer metabolite taxol and heteropolysaccharides, has long suffered from severe habitat fragmentation. In this study, the levels of genetic diversity in two populations of 136 individuals were analyzed based on eleven polymorphic microsatellite loci. Our results suggested that these two populations were characterized by low genetic diversity (NE= 2.303/2.557;HO= 0.168/0.142;HE= 0.453/0.517), a population bottleneck, a low effective population size (Ne = 7/9), a high level of inbreeding (FIS= 0.596/0.702), and a weak, but significant spatial genetic structure (Sp = 0.001,b= −0.001*). Habitat fragmentation, seed shadow overlap and limited seed and pollen dispersal and potential selfing may have contributed to the observed gene tic structure. The results of the present study will enable development of practical conservation measures to effectively conserve the valuable genetic resources of this endangered plant.

White bark pine (Pinus bungeana Zucc.) is popularly cultivated as a garden ornamental tree in China because of the high ornamental value. During July 2017, twig dieback symptoms were found on white bark pine trees in the campus of Henan Agricultural University, Zhenzhou, Henan Province, China. The rate of diseased plants was 25% (up to 40% in 2018) in this campus. Early symptoms appeared as round or oval, red-brown lesions on the twigs, which enlarged progressively, leading to dieback. Two representative Diaporthe strains (zm170130 and zm180920) were isolated and purified from two specimens collected in 2017 and 2018 on potato dextrose agar (PDA). Pycnidia scattered in PDA, dark brown to black, globose to subglobose. Conidiogenous cells phialidic, cylindrical, tapering toward the apex, with periclinal thickening. Two kinds of conidia were produced: α-conidia, unicellular, hyaline elliptical or fusiform, two-guttulate, 5.2 to 9.0 × 2 to 3 µm (n = 50); β-conidia hyaline, aseptate, without guttules, filiform, curved, with obtuse ends, 15.5 to 31 × 0.8 to 1.5 µm (n = 50). These morphological characteristics of the isolates agreed with those of Diaporthe eres (Dissanayake et al. 2015; Liu and Tang 1995; Udayanga et al. 2014). The identity of the two fungal isolates was confirmed by DNA sequencing of the ITS rDNA region (GenBank accession nos. MK265702 and MK265701), TUB gene (GenBank accession nos. MK265704 and MK265703), and histone H3 gene (GenBank accession nos. MK265700 and MK265699), which were over 99% homologous to those consensus sequences of the ex-epitype strain D. eres (KJ210529, KJ420799, KJ210550) (Guarnaccia et al. 2018). The pathogenicity of the isolate zm180920 was tested on 2-year-old healthy twigs of white bark pine in July 2018. Five 2-year-old healthy twigs (30 cm long) cut from 5-year-old trees were used for each treatment. Fifteen mycelial plugs harvested from the periphery of a 7-day-old colony were placed on the surface of the wounded twigs, after the twigs had been surface sterilized with 75% ethanol for 2 min; an equal number of noncolonized plugs of PDA served as the control treatment. All test twigs were kept in a clear plastic box with wet sterilized cotton to maintain high relative humidity at 26 to 30°C in the greenhouse. Symptoms similar to those originally observed on the naturally infected twigs were observed 10 days after inoculation, and the same fungus was reisolated from each of the symptomatic twigs; control twigs remained asymptomatic, and no fungus was isolated. The isolates from the symptomatic twigs were identified as D. eres on the basis of the morphology and the same gene sequences. Koch’s postulates were repeated three times with the same results. The fungus has been reported on peach, grapevine, jujube, Red Robin, and so on in China (Dissanayake et al. 2015; Liu and Tang 1995; Song et al. 2019; Yang et al. 2018; Zhang et al. 2018). To our knowledge, this is the first report of D. eres causing twig dieback of white bark pine in China. Disease control strategies in the region are being further studied.

Carbon nanotubes/carbon fabrics and their reinforced resin matrix composites were manufactured by chemical vapor deposition and molding method, respectively. Different catalytic reduction processes with different catalyst types and reduction temperatures had different effects on their morphology and properties. It was found by a series of characterization methods that the catalytic activity of the bimetallic catalyst was higher than that of the single metal, and the surface uniformity of CNTs catalyzed by Fe-Co was the best. When the reduction temperature reached the growth temperature, the uniformity of CNTs and the interlaminar shear strength of composites increased obviously. The influence mechanism of these parameters was discussed in depth, which provided a fundamental engineering basis for understanding of catalytic reduction process, optimizing of CNTs growth process and the application of high-performance composite materials.

AIM To determine the relationship of left ventricular mass (LVM) and coronary artery volume in diabetic patients and the controls. MATERIALS AND METHODS This work included 448 consecutive patients (206 patients with diabetes and 242 non-diabetic participants) who underwent coronary computed tomography angiography (CTA) for evaluation of coronary artery disease (CAD). The whole coronary artery tree and the LVM were analysed using a cardiac imaging workstation. Multivariable logistic regression analysis was used to determine the independent association with coronary artery lumen volume to LVM ratio (V/M). RESULTS The total coronary artery cumulative volume and the coronary cumulative length showed no differences between groups (p>0.05); however, the LVM in patients with diabetes was significantly greater than that in controls (132.46±45.04 versus 115.82±29.13, p=0.006), and the total epicardial coronary arterial lumen volume to LVM ratio (V/M) was significantly lower in the diabetic group than in the non-diabetic group (2.02 cm3/100±0.73 g versus 2.31 cm3/100±0.82 g, p=0.024). In multivariate logistic regression analysis, diabetes was associated with V/M (odds ratio [OR] 2.027, 95% confidence interval [CI]: 1.462–2.728, p=0.001), and hypertension was not associated with V/M (OR 1.191, 95% CI: 0.978–1.451, p=0.081). CONCLUSION Patients with diabetes demonstrated a significantly lower coronary CTA-derived coronary V/M than controls. V/M may have an important role as a global measure of coronary vasculature in diabetic patients.

The crystalline strain properties of nanoparticles have broad implications in a number of emerging fields, including quantum and biological sensing in which heterogeneous internal strain fields are detrimental to performance. Here we used synchrotron-based Bragg coherent x-ray diffraction imaging (BCDI) to measure three-dimensional lattice strain fields within individual 3C-SiC nanoparticles, a candidate host material for quantum sensing, as a function of temperature during and after annealing up to ${900}^{\phantom{\rule{0.16em}{0ex}}\ensuremath{\circ}}\mathrm{C}$. We observed pronounced homogenization of the initial strain field at temperatures above ${500}^{\phantom{\rule{0.16em}{0ex}}\ensuremath{\circ}}\mathrm{C}$, and we find that the surface layers and central volumes of the nanoparticles reduce strain at similar rates, suggesting a uniform healing mechanism. Thus, we attribute the observed strain homogenization to activation of mobile point defects that annihilate and improve the overall quality of the crystal lattice. This work also establishes the feasibility of performing BCDI at high temperatures (up to ${900}^{\phantom{\rule{0.16em}{0ex}}\ensuremath{\circ}}\mathrm{C}$) to map structural hystereses relevant to the processing of quantum nanomaterials.

To investigate the correlation of ankle-brachial index (ABI) and brachial-ankle pulse wave velocity (baPWV) with cardiac structures and functions changes in patients with essential hypertension (EH).A total of 202 patients with hypertension meeting the inclusion criteria were recruited in our hospital from June 2016 to August 2017. They were divided into 4 groups: the low ABI value group, the normal ABI value group, the increased baPWV value group and the normal baPWV group. Clinical data were collected, including medical histories and received physical examinations, blood pressure measurement, biochemical tests and other examinations through the automatic atherosclerosis tester (VP-l00) and echocardiography.Interventricular septal thickness (IVST) of the low ABI value group was significantly larger than that of the normal ABI value group (p0.05). Compared with those of the normal ABI value group, left ventricular ejection fraction (LVEF) and the ratio of peak velocity flow in the E wave to peak velocity flow in the A wave (E/A) of the low ABI value group were significantly decreased (p0.05). Left atrium diameter (LAD) and IVST of the increased baPWV group were significantly greater than those of the normal baPWV group (p0.05), and left ventricular ejection fraction (LVEF) of the former was smaller than that of the latter (p0.05). Correlation analyses showed that ABI was negatively correlated with IVST (r=-0.713, p0.05) but positively correlated with LVEF and E/A (r=0.685 and 0.572, respectively, p0.05); baPWV was positively related to LAD and LVST (r=0.413 and 0.527, respectively, p0.05) but negatively related to LVEF (r=-0.546, p0.05).ABI and baPWV are significantly associated with changes in cardiac structures and functions in patients with EH, which provide a basis for early intervention in clinical.

In consideration of the important influence of the season change on the temperature difference, the poor thermal inertia of non-thermal insulation walls and the inflammableness of organic thermal insulation walls, it is designed to prepare the phase-change material into the phase-change mortar applied to the exterior of the building walls so as to improve the thermal inertia of the wall in summer. The phase-change material, taking the lowest eutectic mixture mainly formed with lauric acid and myristic acid, hereinafter referred to as ‘fatty acid’, as the main of phase-change material, and the expanded perlite as the inorganic carrier, is prepared into a phase-change aggregate by way of absorption, through encapsulating the aggregate, the optimal process parameters are then determined. The phase-change mortar with the phase-change perlite aggregate is prepared, and simulation test on the thermal performance of the temperature control is conducted. Laboratory results indicate that, the expanded perl...

Ovarian cancer is the most common malignant tumor in female reproductive system. Metformin is an orally taken hypoglycemic agent, which is extensively applied in the clinic. Clinical trials find that there may be a certain degree of action of the metformin in inhibiting malignant tumors. This paper aims to investigate the inhibitory effect and mechanism of metformin on human ovarian cancer cells.Through in vitro cell experiment, the influences of metformin on the proliferation, colony formation and apoptosis of ovarian carcinoma cells were studied. Ovarian cancer cells SKOV-3 and A2780 in logarithmic growth phase were selected and cell proliferation was measured by MTT method. The metformin was processed for 48 h to calculate the survival rate of cells. Also, metformin was processed for 24 h and two weeks or stained with crystal violet, after which Quantity One (Bio-Rad, Hercules, CA, USA) method was used to quantitatively analyze the cell clone formation, meanwhile, the FCM (flow cytometry) was used for the detection and analysis.Intervened by metformin with different concentrations for 48 h, the cell viabilities of SKOV-3 and A2780 cells were respectively reduced by 19.49 ± 2.92%, 45.41 ± 7.95%, 53.84 ± 5.53%, 64.04 ± 4.36% and 11.45 ± 3.12%, 35.42 ± 7.55%, 43.77 ± 5.77%, 53.05 ± 5.55% as compared with that in the control group with statistical significances. After processed by metformin with different concentrations for two weeks, the cells clone numbers of SKOV-3 and A2780 were significantly reduced. Treatment of metformin on SKOV-3 and A2780 cells of human ovarian cancer showed significant apoptosis.The metformin has the inhibitory effect on the cells of human ovarian cancer, which may be through inducing ovarian cancer cell apoptosis.

Liver cancer is one of the most common cancers in the world. Macrothele raven venom, a complicated mixture of neurotoxic peptides, proteins and low molecular weight material, has antitumor properties, but its mechanism of action is unknown. Moderate exercise has been shown to shrink tumors and cause a remarkable reduction in the tumor growth rate. In this study, we examined the antitumor effect of Macrothele raven venom in combination with exercise on tumor-bearing mice. Our results demonstrate that aerobic exercise in combination with venom administered at different doses was much more effective in a mouse H22 hepatoma model compared to separate administration of the 2 treatments. The underlying mechanism of this effect may be related to the expression of various tumor suppressor factors.

Generally, liquid natural gas (LNG) needs to be regasfied by the heat from seawater in order to be supplied to users. In this process, LNG releases a huge mass of cold energy into cooling seawater, which causes economic inefficiency and environmental problems. This paper presents a new idea that is direct contact seawater freezing desalination by utilizing cold energy from LNG. In this new process, the refrigerant named HFE-7100 is used as second medium to exchange the heat between LNG and seawater. A lab scale experimental system is constructed to demonstrate the feasibility of the process. The performance of the ice generator is evaluated at different operating parameters. Some key parameters are discussed for further development of this technology. According to experimental results, the direct contact ice generation shoud be an effective way to combine seawater desalination and cold energy utilization of LNG.

The discrete-time G/D/1 queues with serially correlated batch arrivals and unit service times have wide applications in modern telecommunication systems. Despite the rich literature in their performance analysis, no simple formula on the relation between system size and sojourn time is known. We show that for this specific type of queues, the Little's law can be extended to higher moments. The benefit of this generalised result is that once the moments of either performance measure are available, those of the other will be obtained simultaneously. This result is applied to a particular example of OO-G/D/1 system, where the mean, variance, and skewness of the sojourn delay are derived in closed-form. Numerical examples are given to examine how the correlation influences these performance measures.

Long coherence times are key to the performance of quantum bits (qubits). Here, we experimentally and theoretically show that the Hahn-echo coherence time of electron spins associated with divacancy defects in 4H–SiC reaches 1.3 ms, one of the longest Hahn-echo coherence times of an electron spin in a naturally isotopic crystal. Using a first-principles microscopic quantum-bath model, we find that two factors determine the unusually robust coherence. First, in the presence of moderate magnetic fields (30 mT and above), the 29Si and 13C paramagnetic nuclear spin baths are decoupled. In addition, because SiC is a binary crystal, homo-nuclear spin pairs are both diluted and forbidden from forming strongly coupled, nearest-neighbour spin pairs. Longer neighbour distances result in fewer nuclear spin flip-flops, a less fluctuating intra-crystalline magnetic environment, and thus a longer coherence time. Our results point to polyatomic crystals as promising hosts for coherent qubits in the solid state., The length of time a qubit can store information is linked to its coherence time. Here, the authors demonstrate that industrially important crystals comprising more than one species can host qubits with unexpectedly long coherence times.

The DØ experiment enjoyed a very successful data-collection run at the Fermilab Tevatron collider between 1992 and 1996. Since then, the detector has been upgraded to take advantage of improvements to the Tevatron and to enhance its physics capabilities. We describe the new elements of the detector, including the silicon microstrip tracker, central fiber tracker, solenoidal magnet, preshower detectors, forward muon detector, and forward proton detector. The uranium/liquid-argon calorimeters and central muon detector, remaining from Run I, are discussed briefly. We also present the associated electronics, triggering, and data acquisition systems, along with the design and implementation of software specific to DØ. © 2006 Elsevier B.V. All rights reserved.

We present a measurement of the Drell-Yan cross section at high dielectron invariant mass using 120/pb of data collected in pbar-p collisions at sqrt(s) = 1.8 TeV by the D0 collaboration during 1992-96. No deviation from standard model expectations is observed. We use the data to set limits on the energy scale of quark-electron compositeness with common constituents. The 95% confidence level lower limits on the compositeness scale vary between 3.3 TeV and 6.1 TeV depending on the assumed form of the effective contact interaction., 6 pages, 2 figures, submitted to PRL

Microglia mediated neuroinflammation plays a crucial role in intracerebral hemorrhage (ICH). Raf kinase inhibitor protein (RKIP), a member of the phosphatidylethanolamine-binding protein (PEBP) family, is a negative regulator of inflammatory responses. However, the expression and anti-inflammatory effects of RKIP in microglia after ICH have not been reported. Therefore, in the current study, we investigated the effects of RKIP on inflammatory responses in erythrocyte lysate-treated BV2 microglia. Furthermore, we analyzed the detailed molecular mechanisms underlying the anti-inflammatory effects of RKIP in microglia. Our results showed that the expression level of RKIP was significantly decreased by erythrocyte lysate treatment in BV2 microglia. Overexpression of RKIP inhibited the production of pro-inflammatory molecules. In addition, overexpression of RKIP attenuated neuronal cell death induced by activated microglia. Moreover, RKIP suppressed the activation of NF-κB signaling pathway in erythrocyte lysis-treated BV2 cells. In conclusion, these data suggest that overexpression of RKIP attenuated microglia inflammation through inhibiting the NF-κB signaling pathway in erythrocyte lysis-treated BV2 cells. The present study provides evidence that RKIP may be used as an effective molecular target for the treatment of ICH.

Obstructive jaundice is a common surgical disease and a variety of end-stage severe liver injuries still lack effective treatments. Compared to traditional liver transplantation therapy, herbal treatment is noninvasive and has fewer side effects. Research results have shown that a modified major decoction of bupleurum can reduce the toxic reaction of obstructive jaundice, even though the mechanism is unclear. A period of chronic exercise training can significantly reduce TLR4 expression in mononuclear cells and the secretion of inflammatory cell factors. Our study administered a modified major decoction of bupleurum in combination with exercise in rats with obstructive jaundice and the results indicated that applying a major bupleurum decoction in combination with moderately intense aerobic exercise showed a beneficial effect on adjusting the expression of liver inflammatory cytokines, which thus improved immunity and finally reduced the liver injury of rats with obstructive jaundice.

We study quarkonium spectral functions at high temperatures using a potential model with complex potential. The real part of the potential is constrained by the lattice QCD data on static quark anti-quark correlation functions, while the imaginary part of the potential is taken from perturbative calculations. We find that the imaginary part of the potential has significant effect on quarkonium spectral functions, in particular, it leads to the dissolution of the 1S charmonium and excited bottomonium states at temperatures about 250 MeV and melting of the ground state bottomonium at temperatures slightly above 450 MeV.