To conduct a large population-based survey on multiple sclerosis (MS) prevalence in Shanghai, China.
We established a network of physicians, mainly neurologists, for identifying prevalent patients ...with MS and systematically checked inpatient registers at each hospital in the study area for patients with a diagnosis of MS, neuromyelitis optica, or other demyelinating disorders. MS diagnosis in patients was validated by senior neurologists according to the McDonald criteria.
In total, 123 patients with a validated MS diagnosis from the study population, 8.86 million inhabitants with permanent residence in Shanghai, were alive on the prevalence day. The crude MS prevalence rate was 1.39 cases per 100,000 inhabitants (95% CI: 1.16 to 1.66 cases) in the study population in Shanghai. There were 79 female and 44 male patients with MS, a female-to-male ratio of 1.8. Nearly all (96%) of the patients with validated MS had been examined by MRI.
Multiple sclerosis prevalence in Shanghai is in line with that reported for other Asian populations.
This study mainly investigated the distribution characteristics and risk assessment of 14 antibiotics in typical marine aquaculture farms surrounding the Bohai Sea. The effects of various culture ...modes (outdoor pond culture, recirculating water culture, greenhouse pond culture, raft culture, cage culture and bottom sowing culture), and diverse cultured organism species such as fish (grouper, bass, pike and turbot), mollusk (oyster, scallop, conch and mussel) and sea cucumber on the distribution of antibiotics in different mariculture pond matrices (seawater, sediment/biofilm and organism) were studied. In addition, antibiotic pollution levels in various matrices (water, sediment, organism and feed) from different mariculture areas surrounding the Bohai Sea and the Yellow Sea were compared.
The biofilm on the inner wall of greenhouse pond was more capable of accumulating antibiotics than the biofilm attached to the rope for raft culture and net for cage culture, and other culture sediments. The antibiotic concentration level in the culture matrices (water, sediment/biofilm and organism) was the highest under greenhouse pond culture mode, and that under the industrial recirculating water culture mode was the lowest. Antibiotic concentration in culture matrices of fish ponds was higher than that of sea cucumber ponds and mollusk ponds.
The levels of antibiotics in water and sediment from marine aquaculture farms in Laizhou (Bohai Sea coast) were higher than those in Haiyang and Jimo (Yellow Sea coast). Enrofloxacin in turbot might cause considerable harm to human health, and the risk of antibiotics in other seafood could be ignored. Antibiotic ecological risks and resistance risks were generally low in water. Fluoroquinolones posed medium to high ecological risks in the natural receiving water around the mariculture farm. Trimethoprim and enrofloxacin showed relatively high antibiotic resistance risks in mariculture water and natural water, which might exert selective pressure on the bacterial community in the environment.
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•Antibiotic concentrations were the highest under greenhouse pond among all modes.•For recirculating water culture mode, the antibiotic concentration was the lowest.•More antibiotics were found in fish pond than in sea cucumber pond or mollusk pond.•Antibiotic concentrations were higher in culture matrices of Bohai than Yellow Sea.•Ecological risks and resistance risks of most antibiotics were low in water.
Mesoporous nanocrystalline N-doped SiO2/TiO2 visible-light photocatalysts were prepared by treating SiO2/TiO2 xerogels in a flow of nitrogen gas bubbled through concentrated ammonia solution. ...Structural characterization and performance analysis results revealed that the addition of SiO2 remarkably altered the phase composition, specific surface area, microstructure, as well as the photocatalytic activity of N-doped TiO2. The presence of SiO2 in N-doped TiO2 particles suppressed the formation of rutile phase and the crystal growth of N-doped TiO2 particles during thermal calcinations. When weight ratio of SiO2/TiO2 was in 0.05-0.20, the N-doped SiO2/TiO2 exhibited higher photocatalytic activity than the N-doped TiO2, and optimum ratio was found to be 0.05. The enhanced photocatalytic activity could be attributed to the higher specific area, larger pore volume, and more surface hydroxyl groups in the catalyst.
In order to improve hydrogen storage properties of Ti23V40Mn37 alloy with the two-phase mixture of BCC and C14 Laves, the alloys with different Zr (x = 0, 2, 4, 6, 8 and 10, at.%) partly substituting ...for Ti have been produced. The results show that the primary (dendrite) BCC phase decreases and C14 Laves phase increases with increasing Zr. The secondary (blocky) BCC phase appears when Zr content is more than 6 at.%. The hydrogen absorption rate increases after completely activated because the Zr improves the formation of C14 Laves phase. Meanwhile, the reversible hydrogen capacity of Zr-substituted alloys is higher than that of Zr-free alloy. The effective hydrogen storage capacity reaches the maximum when the composition is Ti21Zr2V40Mn37, with a value of 1.85 wt.% at 293 K. Two desorption plateaus appear when Zr content is more than 6 at.%, and the width of the higher plateau increases with increasing of Zr. The higher plateau results from the fast diffusion of H atom in the smaller secondary BCC phase. With increasing the Zr content, the hysteresis and plateau slope factor increase, which can be attributed to the increasing strain energy of interstitial sites and the affinity of interstitial sites with H.
•BCC phase decreases while C14 Laves phase increases with increasing Zr content.•The Zr-substituted alloys have the fast absorbing rate after activation.•The higher desorption plateau is appeared when the Zr content is more than 6 at.%.•The width of high desorption plateau increases with increasing the Zr content.
Topological materials with exotic quantum properties are promising candidates for quantum spin electronics. Different classes of topological materials, including Weyl semimetal, topological ...superconductor, topological insulator and Axion insulator, etc., can be connected to each other via quantum phase transition. For example, it is believed that a trivial band insulator can be twisted into topological phase by increasing spin-orbital coupling or changing the parameters of crystal lattice. With the results of LDA calculation and measurement by angle-resolved photoemission spectroscopy (ARPES), we demonstrate in this work that the electronic structure of SrSn2As2 single crystal has the texture of band inversion near the critical point. The results indicate the possibility of realizing topological quantum phase transition in SrSn2As2 single crystal and obtaining different exotic quantum states.
An intriguing aspect of unconventional superconductivity is that it always appears in the vicinity of other competing phases, whose suppression brings the full emergence of superconductivity. In the ...iron pnictides, these competing phases are marked by a tetragonal-to-orthorhombic structural transition and a collinear spin-density wave (SDW) transition. There has been macroscopic evidence for competition between these phases and superconductivity as the magnitude of both the orthorhombicity and magnetic moment are suppressed in the superconducting state. Here, using angle-resolved photoemission spectroscopy on detwinned underdoped Ba1-x Kx Fe2 As2 , we observe a coexistence of both the SDW gap and superconducting gap in the same electronic structure. Furthermore, our data reveal that following the onset of superconductivity, the SDW gap decreases in magnitude and shifts in a direction consistent with a reduction of the orbital anisotropy. This observation provides direct spectroscopic evidence for the dynamic competition between superconductivity and both SDW and electronic nematic orders in these materials.
In this paper, four kinds of hard coatings, TiN, CrN, TiAlN and CrAlN (with Al/Ti or Al/Cr atomic ratio around 1:1), were deposited on stainless steel substrates by a lateral rotating cathode arc ...technique. The as-deposited coatings were annealed in ambient atmosphere at different temperatures (500–1000 °C) for 1 h. The evolution of chemical composition, microstructure, and microhardness of these coatings after annealing at different temperatures was systematically analyzed by energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD) and nanoindentation experiments. The oxidation behaviour and its influence on overall hardness of these four coatings were compared. It was found that the ternary TiAlN and CrAlN coatings have better oxidation resistance than their binary counterparts, TiN and CrN coatings. The Cr-based coatings (CrN and CrAlN) exhibited evidently better oxidation resistance than the Ti-based coatings (TiN and TiAlN). TiN coating started to oxidize at 500 °C. After annealing at 700 °C no N could be detected by EDX, indicating that the coating was almost fully oxidized. After annealed at 800 °C, the coating completely delaminated from the substrate. TiAlN started to oxidize at 600 °C. It was nearly fully oxidized (with little residual nitrogen detected in the coating by EDX) and partially delaminated at 1000 °C. Both CrN and CrAlN started to oxidize at 700 °C. CrN was almost fully oxidized (with little residual nitrogen detected in the coating by EDX) and partially delaminated at 900 °C. The oxidation rate of the CrAlN coating is quite slow. After annealing at 1000 °C, only about 19 at.% oxygen was detected and the coating showed no delamination. The Ti-based (TiN and TiAlN) coatings were not able to retain their hardness at higher temperatures (≥
700 °C). On the other hand, the hardness of CrAlN was stable at a high level between 33 and 35 GPa up to an annealing temperature of 800 °C and still kept at a comparative high value of 18.7 GPa even after annealed at 1000 °C, indicating a very promising applicability of this coating for high speed dry machining and other applications under high temperature environments.
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