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Nickel-catalyzed C–H bond functionalization reactions provide an impressive alternative to those with noble metal catalysts due to their unique reactivity and low cost. However, the regioselective C(sp2)–H borylation reaction of arenes accomplished by nickel catalyst remains limited. We herein disclose a silyl-directed ortho C(sp2)–H borylation of substituted arenes with a Ni(cod)2/PMe3/KHMDS catalyst system. Using readily available starting materials, this protocol provides easy access to ortho-borylated benzylic hydrosilanes bearing flexible substitution patterns. These products can serve as versatile building blocks for the synthesis of sila or sila/borine heterocycles under mild conditions. Control experiments and DFT calculations suggest that a catalytic amount of base prompts the formation of Ni(II)-Bpin-ate complex, likely related to the C(sp2)–H bond activation. This borylation reaction might follow an unusual Ni(II)/Ni(IV) catalytic cycle. Nickel-catalyzed C–H bond functionalization reactions provide an impressive alternative to those with noble metal catalysts but the regioselective C(sp2)−H borylation reaction of arenes accomplished by nickel catalyst remains challenging. Here the authors disclose a silyl-directed ortho C(sp2)−H borylation of substituted arenes with a Ni(cod)2/PMe3/KHMDS catalyst system. [ABSTRACT FROM AUTHOR]

Weather forecasting for the Zhangjiakou competition zone of the Beijing 2022 Winter Olympic Games is a challenging task due to its complex terrain. Numerical weather prediction models generally perform poorly for cold air pools and winds over complex terrains, due to their low spatiotemporal resolution and limitations in the description of dynamics, thermodynamics, and microphysics in mountainous areas. This study proposes an ensemble-learning model, named ENSL, for surface temperature and wind forecasts at the venues of the Zhangjiakou competition zone, by integrating five individual models—linear regression, random forest, gradient boosting decision tree, support vector machine, and artificial neural network (ANN), with a ridge regression as meta model. The ENSL employs predictors from the high-resolution ECMWF model forecast (ECMWF-HRES) data and topography data, and targets from automatic weather station observations. Four categories of predictors (synoptic-pattern related fields, surface element fields, terrain, and temporal features) are fed into ENSL. The results demonstrate that ENSL achieves better performance and generalization than individual models. The root-mean-square error (RMSE) for the temperature and wind speed predictions is reduced by 48.2% and 28.5%, respectively, relative to ECMWF-HRES. For the gust speed, the performance of ENSL is consistent with ANN (best individual model) in the whole dataset, whereas ENSL outperforms on extreme gust samples (42.7% compared with 38.7% obtained by ECMWF-HRES in terms of RMSE reduction). Sensitivity analysis of predictors in the four categories shows that ENSL fits their feature importance rankings and physical explanations effectively. [ABSTRACT FROM AUTHOR]

Dual emission NaLaMgWO6:Mn4+, Tb3+ phosphor has been synthesized via high temperature solid state reaction method. The phosphor shows both red Mn4+ emission and green Tb3+ emission and its emission color can change from red to green by adjusting the ratio of Mn4+/Tb3+ doping concentration. Moreover, the luminescence intensity ratio of Tb3+/Mn4+ exhibits a monotonic relationship with both temperature and excitation wavelength within certain range, meaning its possible application in optical temperature sensing and wavelength detection. [ABSTRACT FROM AUTHOR]

Thermo-responsive lysozyme/calcium alginate-g-poly-N-isopropylacrylamide nanohydrogels (Lys/CA-g-PNIPAAm NHs) were prepared from the self-assembly of Lys and sodium alginate-g-poly-N-isopropylacrylamide (SA-g-PNIPAAm) and the ionic cross-linking of CaCl2 in aqueous solution. The Lys/CA-g-PNIPAAm NHs were immobilized on the cleaned surface of a transducer to fabricate a Lys molecularly imprinted sensor (Lys@MIP NHs sensor), which can selectively rebind to Lys in a mixture of closely related compounds. The effects of temperature on the size and the morphology of the Lys/CA-g-PNIPAAm NHs, the removal of Lys templates, the rebinding of Lys targets, and the detection performance of the Lys@MIP NHs sensor were investigated by dynamic light scattering, transmission electron microscope, and differential pulse voltammetry measurements. Compared with other Lys sensors, the fabricated Lys@MIP NHs sensor exhibited the wide linear range from 1 × 10−9 to 1 × 10−3 mg·mL−1 at 30 °C and showed short analysis times, high accuracy, satisfactory selectivity, stability, repeatability, reproducibility, and practical application for Lys detection in urine sample. [ABSTRACT FROM AUTHOR]

The results of treatment for early stage recurrent hepatocellular carcinoma (HCC) remain controversial. This study aimed to analyze the clinical outcomes of recurrent HCC within the Milan criteria following different treatment modalities except liver transplantation. From January 2006 to December 2016, 272 consecutive HCC patients who developed intrahepatic recurrence after hepatectomy that satisfied the Milan criteria and Child–Pugh class A or B liver function were retrospectively enrolled. The outcomes of repeat resection (RR), local ablative therapy (LAT), or transarterial chemoembolization (TACE) were reported, and the prognostic factors of survival were investigated. Among the 272 patients, 136 (50.0%), 71 (26.1%), and 65 (23.9%) received TACE, LAT, and RR treatments, respectively. Treatment-related complications were 9.5%, 11.3%, and 10.7%, respectively, in the three groups. No patient died of treatment-related complication. The 1-, 3-, and 5-year overall survival rates after recurrence were 95.0%, 54.2%, and 45.8%, respectively, in the RR group; 86.6%, 51.7%, and 42.4%, respectively, in the LAT group; and 77.2%, 46.5%, and 38.4%, respectively, in the TACE group. On multivariate analysis, three independent factors related to survival after recurrences were identified. A single tumor nodule and AFP < 200 ng/mL predicted better survival, while a disease-free interval ≤ 1 year was associated with poor outcomes. RR and LAT could achieve good survival outcomes in well-selected patients with recurrent HCC within the Milan criteria, while TACE was the main form of treatment when curative therapy was not considered feasible and the clinical outcomes were satisfactory. [ABSTRACT FROM AUTHOR]

Plant 14–3-3 proteins play key roles in regulating growth, development, and stress responses. However, little is known about this gene family in papaya (Carica papaya L.). We characterized eight 14–3-3 genes from the papaya genome and designed them as CpGRF1–8. Based on phylogenetic, conserved motif, and gene structure analyses, papaya CpGRFs were divided into ε and non-ε groups. Expression analysis showed differential and class-specific transcription patterns in different organs. Quantitative real-time polymerase chain reaction analysis showed that most CpGRFs had large changes in expression during fruit development and ripening. This indicated that the CpGRFs were involved in regulating fruit development and ripening. Significant expression changes occurred after cold, salt, and drought treatments in papaya seedlings, indicating that CpGRFs were also involved in signaling responses to abiotic stress. These results provide a transcription profile of 14–3-3 genes in organs, during fruit development and ripening and in response to stress. Some highly expressed, fruit-specific, and stress-responsive candidate CpGRFs will be identified for further genetic improvement of papayas. [ABSTRACT FROM AUTHOR]

Traditional Chinese Medicine uses plant-based ingredients, many of which have proven to have therapeutic effects through modern pharmacological studies. Such plant metabolites are also found in important cash crops such as tobacco (Nicotiana tabacum L.), the cultivation and processing of which produces waste leaves. We hypothesized that these waste leaves contained active compounds and when extracted could be converted into a useful resource. We, therefore, investigated the constitution of two tobacco cultivars (Basma and K326) using ultra-high-performance liquid chromatography tandem quadrupole time of flight mass spectrometry combined with non-targeted metabolomics. A total of 107 known Traditional Chinese Medicine active ingredients were detected, some of which are widely used in medicine, chemical synthesis, perfumes, and pesticide production. A total of 70 ingredients were present in the two cultivars, at significantly different levels (P < 0.05, variable projection importance > 1). Among them, nicotine, shikimic acid, caffeic acid, scopoletin, quinic acid, 3-caffeoylquinic acid, and isoferulic acid were potentially valuable metabolites. Waste leaves generated in the production of Basma and K326 cultivars have potential as resources for production of these metabolites, but special attention should be paid to the varietal influence. [ABSTRACT FROM AUTHOR]

A novel enhanced oil recovery (EOR) method based on polymer gel-assisted carbon dioxide (CO2) huff and puff was developed aiming to improve the development effect of heavy oil reservoirs with high water cut. The polymer gel prepared using partially hydrolyzed polyacrylamide (HPAM), hexamethylenetetramine, phenol, resorcinol, oxalic acid, and thiocarbamide as raw materials had a special network structure to overcome the challenge of significant heterogeneity in heavy oil reservoirs. The strength of polymer gel reached the maximum value 20,000 mPa·s within 22 h. The temperature resistance and salt resistance of polymer gel directly determined the plugging effect. The polymer gel was placed for 190 days at 85 ℃, and its apparent viscosity retention rate was 66.4%. The salt resistance experiments showed that the apparent viscosity retention rate of this polymer gel at 1.8 wt % NaCl, 0.045 wt % CaCl2, 0.045 wt % MgCl2 was 71.3%, 78.5%, 71.4%, respectively. Huff and puff experiments confirmed that this method could be used to increase the sweep volume and improve the oil displacement efficiency of heavy oil reservoirs with high water cut. Furthermore, the EOR of this method was better than that of water huff and puff, polymer gel huff and puff or CO2 huff and puff. [ABSTRACT FROM AUTHOR]

This paper analyses the effect of wealth inequality on UK economic growth in recent decades with a heterogeneous-agent growth model where agents can enhance individual productivity growth by undertaking entrepreneurship. The model assumes wealthy people are more able to afford the costs of entrepreneurship. Wealth concentration therefore stimulates entrepreneurship among the rich and so aggregate growth, whose fruits in turn are largely captured by the rich. This process creates a mechanism by which inequality and growth are correlated. The model is estimated and tested by Indirect Inference and is not rejected. Policy-makers face a trade-off between redistribution and growth. [ABSTRACT FROM AUTHOR]

Shear experiments were conducted on the cement mortar–sandstone bonding interface and the materials themselves to investigate their loss of shear strength and the deterioration mechanism caused by freezing and thawing cycles. The experimental results show that the shear strength of the bonding interface is much lower than that of the original materials themselves under the same normal stress. The shear strength of this interface decreases linearly with increasing number of freeze–thaw cycles, but it linearly increases with increasing normal stress. The cohesion and internal friction angle also decrease as the number of freeze–thaw cycles increases. In addition, obvious freeze–thaw debonding of this interface is observed and it is first caused by the difference in frost-heaving deformation between the cement mortar and the red sandstone, followed by the frost-heaving pressure in the crack formed in the interface. Finally, the shear damage of this interface has been quantified by reconstitution of the interface morphology. As a result, almost all the shear breakage occurs on the red sandstone side, and a concave rough face arises. With the absence of normal stress, the shear abscission area in the red sandstone increases quickly with increasing number of freeze–thaw cycles. However, with increasing normal stress, this shear abscission area decreases, and the layered composite specimens were prone to shear failure straightly along the bonding interface, because the shear dilatancy deformation is constrained. This study provides the shear failure characteristics of cement mortar–rock interfaces under freeze–thaw cycles and contributes to a better understanding of the freeze–thaw debonding mechanism of protective cement mortar layers on rock surfaces. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to introduce a novel method of percutaneous achievement and maintenance of reduction for acute displaced scaphoid fractures and evaluate the feasibility of this method in treating acute displaced scaphoid fractures as well as explore its indications.Methods: From February 2012 to March 2014, 15 patients with acute displaced scaphoid fractures were treated with our technique. Two Kirschner wires were used to achieve and maintain the reduction of the scaphoid fractures throughout the entire process of the traditional percutaneous screw fixation process. The following parameters including function scores according to modified Mayo wrist scoring system, range of motion (ROM) of the wrist, grip strength, pinch strength, healing time, time to return to work, and final outcomes were recorded.Result: All patients were followed up with a mean period of 2.5 years (range, 2-3.5 years). All fractures healed with a mean of 9.3 weeks (range, 7-11.5 weeks). All patients returned to pre-injury level of activity within six weeks. The functional scores averaged 90.3 (range, 80-100). ROM of the wrist was equal to that of the contralateral side at three months postoperatively. Grip strength and pinch strength compared with contralateral were 98% and 92%, respectively. All were satisfied with the final outcomes.Conclusions: Our technique is successfully performed in acute displaced scaphoid fractures resulting in shortened immobilization and prompt functional recovery. It broadens the indications of the percutaneous method, which means the advantages of the percutaneous method are maximally reserved whilst the drawbacks of open reduction were avoided. [ABSTRACT FROM AUTHOR]

The paper is concerned with the problem of the robust stabilization for a class of fractional order linear systems with positive real uncertainty under Riemann-Liouville (RL) derivatives. Firstly, by utilizing the continuous frequency distributed model of the fractional integrator, the fractional order system is expressed as an infinite dimensional integral order system. And via using indirect Lyapunov approach and linear matrix inequality techniques, sufficient condition for robust asymptotic stability of the fractional order systems and design methods of the state feedback controller are presented. Secondly, by using matrixs singular value decomposition technique the static output feedback controller and observer-based controller for asymptotically stabilizing the fractional order systems are derived. Finally, the validity of the proposed methods are demonstrated by numerical examples. [ABSTRACT FROM AUTHOR]

Carbon-coated olivine-structured LiFePO/C composites are synthesized via an efficient and low-cost carbothermal reduction method using FeO as iron source at a relative low temperature (600 °C). The effects of two kinds of carbon sources, inorganic (acetylene black) and organic (sucrose), on the structures, morphologies, and lithium storage properties of LiFePO/C are evaluated in details. The particle size and distribution of the carbon-coated LiFePO from sucrose (LiFePO/SUC) are more uniform than that obtained from acetylene black (LiFePO/AB). Moreover, the LiFePO/SUC nanocomposite shows superior electrochemical properties such as high discharge capacity of 156 mAh g at 0.1 C, excellent cyclic stability, and rate capability (78 mAh g at 20 C), as compared to LiFePO/AB. Cyclic voltammetric test discloses that the Li-ion diffusion, the reversibility of lithium extraction/insertion, and electrical conductivity are significantly improved in LiFePO/SUC composite. It is believed that olivine-structured LiFePO decorated with carbon from organic carbon source (sucrose) using FeO is a promising cathode for high-power lithium-ion batteries. [ABSTRACT FROM AUTHOR]

A superconducting solenoid magnet has been fabricated and tested for the Accelerator Driven System (ADS), which is a dedicated burner reactor in a double strata fuel cycle to incinerate nuclear waste, at the Institute of Modern Physics of Chinese Academy of Science (IMPCAS). The magnetic field of the superconducting solenoid was measured with hall probes during the magnet excitation and spontaneous quench test. The strains in the superconducting solenoid magnet and its cryogenic support structures were measured by using a compensation bridge of low-temperature strain gauges and a wireless strain acquisition system. The transient strains and their abrupt changes were recorded and compared with the collected signals of the transport current and temperature of the superconducting solenoid during a spontaneous quench test. It indicates that, not only the mechanical behaviors of the superconducting solenoid and the support structures during the excitation can be captured effectively, but also the quench feature can be detected with observations of abrupt strain variations as a quench occurs. The predictions of the magnetic and strain field by means of a coupled finite element analysis were also performed and compared with the experimental measurements resulting in a good agreement. [ABSTRACT FROM AUTHOR]

Yellow-emitting long afterglow phosphors Sr3−xSiO5, xMF2: Eu2+, Dy3+ (0 ≤ x ≤ 0.15, M: Ba, Sr, Ca) have been prepared by high-temperature solid-state reaction method followed with rapid cooling process. Photoluminescence measurement reveals that the main emission of the phosphors locates at 575 nm, corresponding to the 4f65d1–4f7 transition of Eu2+. The introduction of alkaline earth metal fluoride effectively enhances the luminescence intensity and prolongs the afterglow time. Especially, the afterglow of the Sr2.95SiO5, 0.05BaF2: Eu2+, Dy3+ phosphor can last for 12 h. Thermal luminescence measurement shows that the trap density of Sr3SiO5: Eu2+, Dy3+ phosphor can be adjusted by adding different alkaline earth metal fluorides, which offers a feasible way to improve the afterglow properties of silicate phosphors. [ABSTRACT FROM AUTHOR]

14-3-3 protein has emerged as critical regulators of diverse cellular responses. Previous studies found that strong 14-3-3 protein expression was observed and associated with tumor genesis and progression in glioma. Here, we further elucidated the role of 14-3-3 protein in apoptosis of human glioma U251 and U87 cells by global inhibition of 14-3-3 functions with a general 14-3-3 antagonist, difopein. In vitro, morphological observation and DNA laddering assay showed that difopein-treated glioma cells displayed outstanding apoptosis characteristics, such as nuclear fragmentation, appearance of membrane-enclosed apoptotic bodies and DNA laddering fragment. Moreover, flow cytometric detection of phosphatidylserine externalization indicated that difopein-induced apoptosis occurred in a time-dependent manner. Interestingly, inhibiting 14-3-3 with small interfere RNA also induce apoptosis of human glioma U251 cells. Furthermore, RT-PCR and western blot assay further substantiated that difopein had strong effects to induce glioma cell apoptosis through down-regulating Bcl-2, up-regulating Bax and activating caspase-9 and caspase-3. In vivo, retroviral vector was constructed and retroviral-mediated transfer of difopein to glioma was implanted in nude mice. Difopein effectively hindered proliferation and triggered apoptosis of tumor cells implanted into nude mice. This work not only reveals a critical role of 14-3-3 in apoptosis suppression in glioma cells, but also identifies and validates 14-3-3 as a potential molecular target for anticancer therapeutic development. [ABSTRACT FROM AUTHOR]