The evaluation of the fracture toughness of tungsten is required for the design of plasma-facing components in order to ensure safe and durable operation in ITER reactor, being under construction in ...France. During operation, plasma facing materials will be exposed to cyclic thermo-mechanical loads combined with high energy neutron flux, which, in general, reduce the fracture toughness. Characterization of the degradation of the mechanical properties after exposure to the neutron flux involves time consuming and expensive procedures due to nuclear activation and special handling. Subsequently, development of sample miniaturization and protocols to reduce the volume of material under inspection is critical to speed up the progress in R&D. In this work, we propose a combined approach for the reconstruction of the fracture toughness – temperature curve, which is applied in the ductile to brittle transition temperature range. The approach consists of two steps: (i) application of the three point bending tests using miniaturized samples to reveal the transition temperature range on the basis of flexural strain data; (ii) execution of standardized fracture toughness tests at the upper temperature of the transition regime. The results allow the determination of the fracture toughness as a function of temperature with a reasonable accuracy. The validity of the approach has been demonstrated on two commercial tungsten grades produced according to ITER specification and tested in the as-fabricated state. The conclusions are supported by microstructural analysis performed on both standardized and miniaturized samples.
The maintenance of cellular phosphate (Pi) homeostasis is of great importance in living organisms. The SPX domain-containing protein 1 (SPX1) proteins from both Arabidopsis and rice have been ...proposed to act as sensors of Pi status. The molecular signal indicating the cellular Pi status and regulating Pi homeostasis in plants, however, remains to be identified, as Pi itself does not bind to the SPX domain. Here, we report the identification of the inositol pyrophosphate InsP8 as a signaling molecule that regulates Pi homeostasis in Arabidopsis. Polyacrylamide gel electrophoresis profiling of InsPs revealed that InsP8 level positively correlates with cellular Pi concentration. We demonstrated that the homologs of diphosphoinositol pentakisphosphate kinase (PPIP5K), VIH1 and VIH2, function redundantly to synthesize InsP8, and that the vih1 vih2 double mutant overaccumulates Pi. SPX1 directly interacts with PHR1, the central regulator of Pi starvation responses, to inhibit its function under Pi-replete conditions. However, this interaction is compromised in the vih1 vih2 double mutant, resulting in the constitutive induction of Pi starvation-induced genes, indicating that plant cells cannot sense cellular Pi status without InsP8. Furthermore, we showed that InsP8 could directly bind to the SPX domain of SPX1 and is essential for the interaction between SPX1 and PHR1. Collectively, our study suggests that InsP8 is the intracellular Pi signaling molecule serving as the ligand of SPX1 for controlling Pi homeostasis in plants.
The SPX domain-containing protein SPX1 has been proposed as a Pi sensor; however, Pi itself does not bind to SPX1 as a ligand. The Pi signal in plants was hitherto unknown. This study reports that the inositol pyrophosphate InsP8 directly binds to SPX1and is essential for SPX1-mediated inhibition of PHR1, the central regulator of phosphate starvation responses, highlighting the signaling role of InsP8 in regulating Pi homeostasis in plants.
The development of drug-resistance in the opportunistic pathogen
has become a global public health concern. Due to the share of similar flora between pets and their owners, the detection of ...pet-origin antibiotic-resistant
is necessary. This study aimed to detect the prevalence of feline-origin ESBL
in China and to explore the resistance elimination effect of garlic oil to cefquinome on ESBL
. Cat fecal samples were collected from animal hospitals. The
isolates were separated and purified by indicator media and polymerase chain reaction (PCR). ESBL genes were detected by PCR and Sanger sequencing. The MICs were determined. The synergistic effect of garlic oil and cefquinome against ESBL
was investigated by checkerboard assays, time-kill and growth curves, drug-resistance curves, PI and NPN staining, and a scanning electronic microscope. A total of 80
strains were isolated from 101 fecal samples. The rate of ESBL
was 52.5% (42/80). The prevailing ESBL genotypes in China were
,
, and
. In ESBL
, garlic oil increased the susceptibility to cefquinome with FICIs from 0.2 to 0.7 and enhanced the killing effect of cefquinome with membrane destruction. Resistance to cefquinome decreased with treatment of garlic oil after 15 generations. Our study indicates that ESBL
has been detected in cats kept as pets. The sensitivity of ESBL
to cefquinome was enhanced by garlic oil, indicating that garlic oil may be a potential antibiotic enhancer.
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•The ore-forming fugacities are first discussed in the middle belt of Xiaoqinling gold field.•The mineral paragenesis is used to constrain physicochemical conditions of ...mineralization.•The ore-forming environment is relative oxidation in the early of main mineralization stage.
The Jinqu Au deposit, located in central Xiaoqinling gold field along the North China Craton’s southern margin, has total reserve of 21 t of Au with 4.23 g/t Au on average. It consists cccmainly of ore-bearing auriferous quartz veins in amphibolite facies metamorphic rocks of the Archean Taihua Group. The deposit’s mineral paragenesis and ore-forming processes have never been studied. This paper reports its mineral paragenesis, which includes sulfides (pyrite, galena, chalcopyrite, pyrrhotite, sphalerite, molybdenite and bornite), oxides (rutile, scheelite, hematite, magnetite), tellurides (sylvanite (Au, Ag)2Te4, hessite Ag2Te, petzite Ag3AuTe2, krennerite Au3AgTe8, calaverite AuTe2, stützite Ag5−xTe3, empressite AgTe, rucklidgeite (Pb, Bi)3Te4, altaite PbTe, volynskite AgBiTe2, tetradymite Bi2Te2S, lingbaoite (AgTe3) and melonite NiTe2) and native elements (tellurium and gold). Based on our data, the associated ore-forming processes can be deduced as: iron oxides → (CO2(g) and H2S(g) loss, ƒTe2/ƒS2 ratio increase) sulfides, Au-Ag-tellurides → (condensation of H2Te vapor) Pb-Bi-tellurides → (mixing with meteoric water) carbonate. It has been indicated by thermodynamic modelling that formation of Au-Ag-Te-bearing minerals occurred under physico-chemical conditions of logƒTe2 values from −7.28 to −3.21, logƒO2 values from −26.67 to −26.44, logƒH2S values from −1.34 to 0.34, logƒS2 values from −9.53 to −5.64, logαAu+(aq)/αAg+(aq) values from −4.72 to −4.55 and pH values from 3.33 to 4.20 at 365 ℃ and logƒTe2 values from −10.53 to −6.62, logƒO2 values from −31.99 to −30.98, logƒH2S values from −0.65 to −0.36, logƒS2 values from −13.62 to −7.20, logαAu+(aq)/αAg+(aq) values from −6.42 to −6.21 at 335 ℃. The changes in physico-chemical conditions and in precipitation of Au-Ag-Te-bearing minerals were due to boiling or to condensation of Te-rich magmatic gas into ore-forming fluids. These reflect evolution from an early oxidizing to a later relatively reducing mineralization environment. Therefore, compared with the Dahu Au-Mo deposit and with the Yangzhaiyu Au deposit, which exist in the southern and northern parts of the Xiaoqinling region, respectively, the ore paragenesis and ore-forming physico-chemical conditions of the Jinqu Au deposit were different such that its characteristics are similar to low-sulfidation Au deposits.
Potassium-ion hybrid capacitors (PIHCs) reconcile the advantages of batteries and supercapacitors, exhibiting both good energy density and high-power density. However, the low-rate performance and ...poor cycle stability of battery-type anodes hinder their practical application. Herein, phosphorus/nitrogen co-doped hollow carbon fibers (P-HCNFs) are prepared by a facile template method. The stable grape-like structure with continuous and interconnected cavity structure is an ideal scaffold for shortening the ion transport and relieving volume expansion, while the introduction of P atoms and intrinsic N atoms can create abundant extrinsic/intrinsic defects and additional active sites, reducing the K
+
diffusion barrier and improving the capacitive-controlled capacity. The P-HCNFs delivers a high specific capacity of 310 mAh·g
−1
at 0.1 A·g
−1
with remarkable ultra-high-rate performance (140 mAh·g
−1
at 50 A·g
−1
) and retains an impressive capacity retention of 87% after 10,000 cycles at 10 A·g
−1
. As expected, the as-assembled PIHCs present a high energy density (115.8 Wh·kg
−1
at 378.0 W·kg
−1
) and excellent capacity retention of 91% after 20,000 cycles. This work not only shows great potential for utilizing heteroatom-doping and structural design strategies to boost potassium storage, but also paves the way for advancing the practicality of high-energy PIHCs devices.
Graphical abstract
The corona discharge techniques, which are employed to orient dipoles and built up charges inside functional polymers, can develop important commercial applications of electroactive polymers (EAPs) ...and electrets for energy storage devices, air filters, electroacoustic and electromechanical transducers. We propose hereby an elective hybrid approach to the point-plane corona modeling in order to obtain more accurate electron flow in unipolar corona discharge system. A coupled system of partial differential equations (PDEs) w.r.t. Navier-stokes equations and hydrodynamic drift diffusion equations described the nature of photo-ionization, where the secondary avalanche in the discharge process was demonstrated. The simulation was verified by comparison with Surface Potential (SP) measurement of the nano-composites after corona polarization. Consequently, the spacial electric potential distribution and initial surface potential could be obtained by the means of finite elements method (FEM), which provided a good numerical approach for the experimental data of electrostatic surface potential. In addition, the influence of nano particle on the charge retain ability of the insulating polymers was also investigated, which could be a guideline for designing an effective poling method on the functional polymers applied in electrical energy storage devices sensors, actuators and transducer etc.
•Upper Cretaceous paleomagnetic data was obtained from the East Qiangtang Block (EQB).•No inclination shallowing exists in the Late Cretaceous red-beds in southeastern EQB.•Southward motion is ...consistent with escape of the QB during the India–Asia collision.
High-temperature magnetization component was isolated between 600°C and 680°C from Upper Cretaceous red-beds in the Mangkang area, in the eastern end of the Qiangtang Block, Tibetan Plateau. The tilt-corrected site-mean direction is Ds/Is=51.3°/56.1°, with k=31.0 and α95=6.5°, corresponding to a paleolatitude of 36.7±6.7°N. Positive fold and reversal tests indicate a primary magnetization. Inclination shallowing tests show that inclination bias is not present in the Upper Cretaceous red-beds of the Qiangtang Block that might induce through depositional and/or compaction process. However, previous paleomagnetic data obtained from Cretaceous and Paleocene–Eocene volcanic rocks show that the paleolatitudes of the Lhasa Block were 17.1±3.3°N and 22.3±4.4°N, respectively, and 28.7±3.7°N for the central Qiangtang Block yielded from Eocene volcanic rocks. These results show that there was a ∼10° latitudinal discrepancy between the Lhasa Block and Qiangtang relative to Eurasia. However, the Mangkang area of the southeastern Qiangtang Block experienced ∼3.2±7.8° to 7.3±5.2° southward extrusion and ∼40° clockwise rotational movement relative to Eurasia since the Cretaceous, which coincided with the Early Cenozoic rotational extrusion of the Indochina and Shan-Thai Blocks. The crustal deformation in the eastern Qiangtang Block should have been caused by the Indian Plate penetrating into Eurasia in the eastern end of Tibetan Plateau and the formation of the Eastern Himalaya Syntaxis since the Oligocene/Miocene.
The development of antimicrobial resistance in the opportunistic pathogen
has become a global public health concern. Due to daily close contact, dogs kept as pets share the same
with their owners. ...Therefore, the detection of antimicrobial resistance in canine
is important, as the results could provide guidance for the future use of antibiotics. This study aimed to detect the prevalence of antibiotic-resistance of canine origin
in Shaanxi province and to explore the inhibition effect of magnolol combined with cefquinome on MDR E. coli, so as to provide evidence for the use of antibiotics.
Canine fecal samples were collected from animal hospitals. The
isolates were separated and purified using various indicator media and polymerase chain reaction (PCR). Drug-resistance genes
were also detected by PCR. The minimum inhibitory concentration (MIC) was determined for 10 antibiotics using the broth-microdilution method. Synergistic activity of magnolol and cefquinome against multidrug-resistant (MDR)
strains was investigated using checkerboard assays, time-kill curves, and drug-resistance curves.
A total of 101
strains were isolated from 158 fecal samples collected from animal hospitals. MIC determinations showed that 75.25% (76/101) of the
strains were MDR. A total of 22 drug-resistance genes were detected among the 101 strains. The
gene exhibited the highest detection rate (89.77%). The TetA and Sul gene also exhibited high detection rate (66.34 and 53.47%, respectively). Carbapenem-resistant
strains were found in Shangluo and Yan'an. Additionally, in MDR
initially resistant to cefquinome, magnolol increased the susceptibility to cefquinome, with an FICI (Fractional Inhibitory Concentration Index) between 0.125 and 0.5, indicating stable synergy. Furthermore, magnolol enhanced the killing effect of cefquinome against MDR
. Resistance of MDR
to cefquinome decreased markedly after treatment with magnolol for 15 generations.
Our study indicates that antibiotic-resistance
has been found in domestic dogs. After treatment with magnolol extracted from the Chinese herb Houpo (
), the sensitivity of MDR
to cefquinome was enhanced, indicating that magnolol reverses the resistance of MDR
. The results of this study thus provide reference for the control of
resistance.
Abstract
Shape memory materials can be utilized to realize fast shape customization for personalized comfort fitting experiences. In this paper, a series of body-temperature programmable shape memory ...elastomers are developed for comfort fitting. Unlike the reported ones, in which the shape switch is realized due to body-temperature phase transition (around 37 °C), these newly developed ones are fabricated with silicone rubber (as elastic component) and a kind of polycaprolactone (PCL, as transition component) that has melting point of about 56 °C and much lower crystallization temperature. The thermal properties, shape memory performances, mechanical behaviors under uni-axial tension at room temperature and at human body temperature (37 °C) are investigated. The specialty of these shape memory elastomers is that the programming is not carried out at around melting point of the transition component. Instead, it could be done upon cooling to 37 °C. The temporary shape is fixed only after completion of PCL crystallization. As the melting point of PCL is much higher (56 °C), the mechanical properties of these shape memory elastomers are ensured rather stable near 37 °C, which eliminates the concern of shaping/fitting failure when ambient temperature fluctuates. Besides, ultra-softness and high stretchability at room temperature are revealed as well. Excellent shape memory performance of these elastomers at 37 °C is also confirmed. The shape fixity ratio is over 90% when PCL content reaches wt% of 35%. In such a way, these elastomers are able to well duplicate the local shapes of human body in actual fitting. Upon reheating to 80 °C, they also can completely recover to their original shapes. The fitting time window at 37 °C is revealed around 5 min, which is rather appropriate in practice. The yielding behaviors during tension and long-term shaping/fitting performance of these elastomers are also discussed. A simple wearable orthotic device for hallux valgus is developed for proof-of-concept. It is concluded that these newly developed shape memory elastomers are well suited candidates for comfort fitting.
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