In this report, we demonstrate that sodium hydrosulfide （NariS）, a hydrogen sulfide （H2S） donor, promoted adventitious root formation mediated by auxin and nitric oxide （NO）. Application of the HzS ...donor to seedling cuttings of sweet potato （Ipomoea batatas L.） promoted the number and length of adventitious roots in a dose-dependent manner. It was also verified that H2S or HS- rather than other sulfur-containing components derived from NariS could be attributed to the stimulation of adventitious root formation. A rapid increase in endogenous H2S, indole acetic acid （IAA） and NO were sequentially observed in shoot tips of sweet potato seedlings treated with HallS. Further investigation showed that H2S-mediated root formation was alleviated by N-1-naphthylphthalamic acid （NPA）, an IAA transport inhibitor, and 2-（4-carboxyphenyl）. 4,4,5,5-tetramethylimidazoline-1-oxyl-3-0xide （cPTIO）, an NO scavenger. Similar phenomena in H2S donor-dependent root organogenesis were observed in both excised willow （Salix matsudana var. tortuosa Vilm） shoots and soybean （Glycine max L.） seedlings. These results indicated that the process of H2S-induced adventitious root formation was likely mediated by IAA and NO, and that H2S acts upstream of IAA and NO signal transduction pathways.
Lysophosphatidic acid receptor 5 (LPAR5) is involved in mediating thyroid cancer progression, but the underlying mechanism needs to be further revealed. In this study, we confirmed that LPAR5 is ...upregulated in papillary thyroid carcinoma (PTC), especially in BRAF‐like PTC, by analyzing The Cancer Genome Atlas (TCGA) database and performing immunohistochemistry assay in human thyroid cancer tissues. LPAR5‐specific antagonist TC LPA5 4 treatment inhibited CGTH‐W3, TPC‐1, B‐CPAP, and BHT‐101 cell proliferation, CGTH‐W3 and TPC‐1 cell migration significantly. In vivo, TC LPA5 4 treatment could delay CGTH‐W3 xenograft growth in nude mice. We also found that LPAR5‐specific antagonist TC LPA5 4, PI3K inhibitor wortmannin, or mTOR inhibitor rapamycin pretreatment abrogated phosphorylation of Akt and p70S6K1 stimulated by LPA in CGTH‐W3 and TPC‐1 cells. Stimulating CGTH‐W3 cells transfected with pEGFPC1‐Grp1‐PH fusion protein with LPA resulted in the generation of phosphatidylinositol (3,4,5)‐triphosphate, which indicates that PI3K was activated by LPA directly. The p110β‐siRNA instead of p110α‐siRNA transfection abrogated the increase of levels of phosphorylated Akt and S6K1 stimulated by LPA. Furthermore, immunoprecipitation assay confirmed an interaction between LPAR5 and p110β. Overall, we provide new insights that the downregulation of LPAR5 decreased the proliferation and migration phenotype via the PI3K/Akt pathway. Inhibition of LPAR5 or the PI3K/Akt signal may be a novel therapeutic strategy for treating thyroid cancer.
Lysophosphatidic acid receptor 5 (LPAR5) is upregulated in thyroid cancer and plays important roles in thyroid cancer proliferation and migration through activating PI3K kinase directly. Inhibition of LPAR5 or the PI3K/Akt pathway may be used for the therapy of metastatic and recurrent thyroid cancer expressing high levels of LPAR5.
The lithium–sulfur (Li–S) battery is regarded as a promising high‐energy‐density battery system, in which the dissolution–precipitation redox reactions of the S cathode are critical. However, soluble ...Li polysulfides (LiPSs), as the indispensable intermediates, easily diffuse to the Li anode and react with the Li metal severely, thus depleting the active materials and inducing the rapid failure of the battery, especially under practical conditions. Herein, an organosulfur‐containing solid electrolyte interphase (SEI) is tailored for the stabilizaiton of the Li anode in Li–S batteries by employing 3,5‐bis(trifluoromethyl)thiophenol as an electrolyte additive. The organosulfur‐containing SEI protects the Li anode from the detrimental reactions with LiPSs and decreases its corrosion. Under practical conditions with a high‐loading S cathode (4.5 mgS cm−2), a low electrolyte/S ratio (5.0 µL mgS−1), and an ultrathin Li anode (50 µm), a Li–S battery delivers 82 cycles with an organosulfur‐containing SEI in comparison to 42 cycles with a routine SEI. This work provokes the vital insights into the role of the organic components of SEI in the protection of the Li anode in practical Li–S batteries.
An organosulfur‐containing solid electrolyte interphase (SEI) is tailored for the stabilization of the Li anode in Li–S batteries by employing 3,5‐bis(trifluoromethyl)thiophenol as an electrolyte additive. The organosulfur‐containing SEI protects the Li anode from the detrimental reactions with Li polysulfides (LiPSs). A Li–S battery delivers 82 cycles with an organosulfur‐containing SEI in comparison to 42 cycles with a routine SEI under practical conditions.
ABSTRACT
Lorentz invariance violations (LIV) can yield vacuum birefringence, which results in an energy-dependent rotation of the polarization vector of linearly polarized emission from astrophysical ...sources. It is believed that if the relative rotation angle (ΔΘ) of the polarization vector of high-energy photons with respect to that of low-energy photons is larger than π/2, then the net polarization of the signal would be significantly depleted and could not be as high as the observed level. Hence, the measurement of high polarization implies that ΔΘ should not be too large. In this work, we assemble recent detections of prompt emission polarization in gamma-ray bursts (GRBs), all of whom have high detection significance. Following the method shown in Lin, Li & Chang (2016), we give a detailed calculation on the polarization evolution arising from the LIV effect for each GRB, and confirm that, even if ΔΘ is approaching to π/2, the net polarization is not severely suppressed, and more than 60 per cent of the initial polarization can be conserved. Applying this method to our GRB polarimetric data, we improve existing sensitivities to LIV involving photons by factors ranging from 2 to 10. In addition, we prove that our constraints are not greatly affected by uncertainties in the spectral parameters of GRBs.
This technical note investigates the problem of fault estimation for a class of nonlinear systems with Lipschitzian nonlinearities. In most of the existing fault estimation approaches, the observer ...matching condition should be satisfied. However, this condition is hard to meet for many systems. To overcome this restriction, a new fault estimation method is proposed, where an intermediate variable is introduced and a specially designed intermediate estimator is proposed to estimate the state and the faults simultaneously by exploiting the properties of fault distribution matrix. It is proved that the states of the error system are uniformly ultimately bounded. Simulation examples verify the effectiveness of the proposed method.
Perovskite solar cells (PSCs) may offer huge potential in photovoltaic conversion, yet their practical applications face one major obstacle: their low stability, or quick degradation of their initial ...efficiencies. Here, a new design scheme is presented to enhance the PSC stability by using low‐temperature hydrothermally grown hierarchical nano‐SnO2 electron transport layers (ETLs). The ETL contains a thin compact SnO2 layer underneath a mesoporous layer of SnO2 nanosheets. The mesoporous layer plays multiple roles of enhancing photon collection, preventing moisture penetration and improving the long‐term stability. Through such simple approaches, PSCs with power conversion efficiencies of ≈13% can be readily obtained, with the highest efficiency to be 16.17%. A prototypical PSC preserves 90% of its initial efficiency even after storage in air at room temperature for 130 d without encapsulation. This study demonstrates that hierarchical SnO2 is a potential ETL for fabricating low‐cost and efficient PSCs with long‐term stability.
Low‐temperature hydrothermally grown hierarchical SnO2
, a mesoporous layer of nanosheet arrays on a compact nanoparticle layer, is used as the electron transporting layer to enhance the long‐term stability of perovskite solar cells. A mesoporous device preserves 90% of its initial efficiency, even after storage in air for 130 d without encapsulation.
All‐inorganic bismuth‐halide perovskites are promising alternatives for lead halide perovskites due to their admirable chemical stability and optoelectronic properties; however, these materials ...deliver inferior photoluminescence (PL) properties, severely hindering their prospects in lighting applications. Here, a novel air‐stable but non‐emissive perovskite Rb3BiCl6 is synthesized, and the material is used as a prototype to uncover origin of the poor optical performance in bismuth‐halide perovskite. It is found that the extremely strong exciton–phonon interactions with a large coupling constant up to 693 meV leads to the seriously nonradiative recombination, which, however, can be effectively suppressed to 347 meV by introducing Sb3+ ions. As a result, Sb3+‐doped Rb3BiCl6 exhibits a stable yellow emission with unprecedented PL quantum yield up to 33.6% from self‐trapped excitons. Systematic spectroscopic characterizations and theoretical calculations are carried out to unveil the intriguing photophysical mechanisms. This work reveals the effect of exciton–phonon interaction, that is often underemphasized, on a material's photophysical properties.
All‐inorganic lead‐free bismuth‐halide perovskite with excellent structural stability shows inferior photoluminescence performance due to the extremely strong exciton–phonon interaction, which however can be effectively suppressed by an ion doping strategy. This work provides a new avenue for the development of high‐performance luminous perovskites (or metal halides) by manipulating the exciton–phonon interaction.
High‐entropy alloy nanoparticles (HEA NPs) have aroused great interest globally with their unique electrochemical, catalytic, and mechanical properties, as well as diverse activity and multielement ...tunability for multi‐step reactions. Herein, a facile low‐temperature synthesis method at atmospheric pressure is employed to synthesize Pd‐enriched‐HEA‐core and Pt‐enriched‐HEA‐shell NPs with a single phase of face‐centred cubic structure. Interestingly, the lattice of both Pd‐enriched‐HEA‐core and Pt‐enriched‐HEA‐shell enlarge during the formation process of HEA, with tensile strains included in the core and shell of HEA. The as‐obtained PdAgSn/PtBi HEA NPs show excellent electrocatalytic activity and durability for methanol oxidation reaction (MOR) and ethanol oxidation reaction (EOR). The specific (mass) activity of PdAgSn/PtBi HEA NPs for MOR is 4.7 mA cm−2 (2874 mA mg(Pd+Pt)−1), about 1.7 (5.9) and 1.5 (4.8) times higher than that of commercial Pd/C and Pt/C catalysts, respectively. Additional to high‐entropy effect, Pt sites and Pd sites on the interface of the HEA act synergistically to facilitate the multi‐step process towards EOR. This study offers a promising way to find a feasible route for scalable HEA manufacturing with promising applications.
A facile low‐temperature synthesis method at atmospheric pressure is employed to synthesize nanoparticles (NPs) with Pd‐enriched high‐entropy alloy (HEA) core and Pt‐enriched HEA shell in a pure phase of face‐centred cubic structure. The obtained PdAgSn/PtBi HEA NPs exhibit 2874 and 3386 mA mg(Pd+Pt)−1 for methanol oxidation reaction (MOR) and ethanol oxidation reaction (EOR), respectively.
Background： Sacroiliac （SI） screw fixation is a demanding technique, with a high rate of screw malposition due to the complex pelvic anatomy. TiRobot- is an orthopedic surgery robot which can be used ...for SI screw fixation. This study aimed to evaluate the accuracy of robot-assisted placement of SI screws compared with a freehand technique. Methods：Thirty patients requiring posterior pelvic ring stabilization were randomized to receive freehand or robot-assisted SI screw fixation, between January 2016 and June 2016 at Beijing Jishuitan Hospital. Forty-five screws were placed at levels S1 and S2. In both methods, the primary end point screw position was assessed and classified using postoperative computed tomography. Fisher＇s exact probability test was used to analyze the screws＇positions. Secondary end points, such as duration of trajectory planning, surgical time after reduction of the pelvis, insertion time for guide wire, number of guide wire attempts, and radiation exposure without pelvic reduction, were also assessed. Results： Twenty-three screws were placed in the robot-assisted group and 22 screws in the freehand group; no postoperative complications or revisions were reported. The excellent and good rate of screw placement was 100% in the robot-assisted group and 95% in the freehand group. The P value （0.009） showed the same superiority in screw distribution. The fluoroscopy time after pelvic reduction in the robot-assisted group was significantly shorter than that in the freehand group （median Q1, Q3： 6.0 6.0, 9.0 s vs. median Q1, Q3： 36.0 21.5, 48.0 s; χ2 = 13.590, respectively, P 〈 0.001）; no difference in operation time after reduction of the pelvis was noted （χ2 = 1.990, P = 0.158）. Time for guide wire insertion was significantly shorter for the robot-assisted group than that for the freehand group （median Q1, Q3： 2.0 2.0, 2.7 min vs. median Q1, Q3： 19.0 15.5, 45.0 min; χ2 = 20.952, respectively, P 〈 0.001）. The number of guide wire attempts in the robot-assisted group was significantly less than that in the freehand group （median Q1, Q3： 1.0 1.0,1.0 time vs. median Q1, Q3： 7.0 1.0, 9.0 times; χ2 = 15.771, respectively, P 〈 0.001）. The instrumented SI levels did not differ between both groups （from S1 to S2, χ2 = 4.760, P = 0.093）. Conclusions： Accuracy of the robot-assisted technique was superior to that of the freehand technique. Robot-assisted navigation is safe for unstable posterior pelvic ring stabilization, especially in S1, but also in S2. SI screw insertion with robot-assisted navigation is clinically feasible.
In this paper, we propose an adaptive fault-tolerant control strategy for flexible string systems and extend the result to Euler-Bernoulli beam systems under deferred and asymmetric boundary partial ...output constraints. The designed control strategies consist of a boundary control law and two adaptive parameter update laws. A hyperbolic tangent function is applied to realize rejection to disturbance. With the adaptive technique, the unknown actuator faults are compensated. The deferred partial output constraints are addressed by utilizing a shifting function to remove the initial limitation on the boundary output and constructing a novel asymmetric barrier Lyapunov function. Furthermore, it is proven that both the controlled string and Euler-Bernoulli beam systems are well-posed and meet the deferred constraint conditions. Finally, extensive simulation examples are presented to demonstrate the performance of the proposed control methods.
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