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A method based on kernel extreme learning machine is proposed for accurate localization and recognition of human bones. In this method, the human skeleton is divided into 16 key nodes based on physiology, and the human skeleton model is formed by connecting lines between the nodes. The sequence images of human actions are taken as input and fed into the input and hidden layers of the extreme learning machine. During the learning and training process, a kernel function is used to construct a kernel matrix to complete weight allocation. The experimental study was conducted on the action sequences of figure skaters, and the results showed that our method achieved an accuracy rate of over 90% in recognizing human bones, with individual sequences achieving an accuracy rate of over 95%, which is superior to convolutional neural network (CNN) and long short-term memory (LSTM) methods. [ABSTRACT FROM AUTHOR]

Background: To explore the pharmacological mechanism of the anti-hepatitis B virus of Phyllanthus urinaria L. through network pharmacological analysis and experimental validation. Method: The active ingredient, target of action and target of action related to hepatitis B were clarified by searching the herb group identification, GeneCards and OMIM databases, and the protein interaction relationship was obtained by using the String database, and the protein interaction network map was constructed by using Cytoscape software. We also performed gene ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analysis of key targets of the anti-hepatitis B action of Phyllanthus urinaria L. and predicted the core targets and pathways of Phyllanthus urinaria L. anti-hepatitis B. The main targets predicted by network pharmacology were then validated by HepG2.2.15 cell experiments. Results: By searching active ingredient targets and hepatitis B disease targets, a total of 19 active ingredients and 64 related targets of action were retrieved from Phyllanthus urinaria L., and a total of 51 common targets were obtained by mapping the obtained hepatitis B disease targets and drug targets. protein protein interaction network analysis indicated that targets including TNF, JUN, AKT1, IL-10, IL-1B, CAT, HMOX1, NFE2L2, and CASP3 and other targets may be the core targets.gene ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analysis showed that the treatment of hepatitis B by Phyllanthus urinaria L. mainly included inflammation and oxidation-related processes, and the signaling pathways mainly included fluid shear stress and atherosclerosis, VEGF, and hepatocellular carcinoma. The results of the in vitro test showed that after the action of different concentrations of the extracts of the Phyllanthus urinaria L.in the safe concentration range on cells HepG2.2.15, HBsAg, HBeAg and hepatitis B virus DNA levels were significantly inhibited, and NFE2L2 and HMOX1 were affecting hepatitis B virus transcription and replication by regulating the oxidative stress response. Conclusion: Using an integrated network pharmacology approach, this study revealed the active components and potential targets of Phyllanthus urinaria L. for the treatment of the hepatitis B virus, providing a theoretical basis for the research and clinical application of Phyllanthus urinaria L.. [ABSTRACT FROM AUTHOR]

The pores and coarse lamellar Mg17Al12 that inevitably occur in the weld zone are the major challenge for laser-welded magnesium (Mg) alloys including AZ31B. In order to improve microstructure uniformity and eliminate welding defects, a new process assisted with combination of heat and cryogenic treatment was applied in this study. The results showed that after solution treatment, the number and size of precipitates decreased and the uniformity of the microstructure improved. After cryogenic treatment, the lamellar Mg17Al12 was cracked into particles, and the grain size was refined. After solution + cryogenic treatment, Al8Mn5 substituted the lamellar Mg17Al12. Through studying the changes in microhardness, precipitates, and microstructure under different treatments, it was found that the conversation of Mg17Al12 from lamellar state into particle-like state as well as the appearance of dispersed Al8Mn5 particles played a second-phase strengthening role in improving the mechanical properties of Mg alloy laser-welded joint, and the tensile strength (258.60 MPa) and elongation (10.90%) of the sample were 4.4% and 32.6% higher than those of the as-welded joint. [ABSTRACT FROM AUTHOR]

An electrochemical method for the C(sp2)−H thiocyanation of pyrazol‐5‐amines and enamines were developed in an undivided cell. A variety of thiocyanated pyrazol‐5‐amine and enamine derivatives were accessed in 36–91% yields, employing thiocyanate salts as electrolyte and thiocyanating reagent. Moreover, this electrochemical protocol can be extended to the synthesis of various iodinated and brominated pyrazol‐5‐amine derivatives in 51–95% yields. This electrochemical protocol does not require a metal or external chemical oxidants and tolerates unprotected amino groups. [ABSTRACT FROM AUTHOR]

Background: In the wake of the severe impact of COVID-19 on the food security of the vulnerable groups in rural areas, the issue of how to achieve the Sustainable Development Goals 2 aims to "Zero Hunger" (SDG 2) and ensure the food safety of farmers has drawn unprecedented attention. Nutritional intake is generally used as an important indicator to reflect family food security. Under the background that Chinese farmers have gradually changed from the traditional diversified production mode to the specialized production of crops, the main purpose of this article is to explore what are the impact of crop specialization on farmers' nutritional intake? Could the specialization of crop production be taken as an important measure to ensure the food safety of farmers and achieve the SDG 2? Methods: Based on the micro-survey data from 866 farmer households in China, this paper using Seemingly Unrelated Regressions model, Group Regression model and Mediating Effect model to analyze the average and heterogeneous effects of crop specialization on the nutritional intake of farmers, as well as the mediating effect of income. In addition, robustness test and endogenous treatment were performed by using alternative explanatory variables and IV-2SLS method was used to estimate the results. Results: After correcting for endogenous bias, crop specialization had a significant negative impact on energy intake and fat intake of farmers at the statistical level of 5% and 1% respectively, especially for farmers in mountainous areas. Household income played a mediating effect on the effect of crop specialization on farmers' energy and fat intake, and the proportion of the masking effect was 8.43% and 8.96% respectively. In addition, household financial capital and social capital have a significant positive impact on farmers' nutritional intake. Conclusions: Crop specialization cannot guarantee the food safety of farmers in terms of nutritional intake. However, when the development trend of crop specialization is irreversible, more attention should be paid to improving the level of various livelihood capital of farmers, especially those in mountainous areas, and to continuously increasing their income to ease and ultimately eliminate the negative impact of crop specialization on farmers' nutritional intake, which finally make everyone realize the SDG 2. [ABSTRACT FROM AUTHOR]

[Display omitted] • Carbonate weathering is enhanced by anthropogenic H 2 SO 4. • Distinct impacts of acid precipitation on carbonate and silicate catchments. • Soil buffering effect leads to a limited effect of acid precipitation on chemical weathering in silicate catchments. • Considerable reduction of carbon sink flux by H 2 SO 4 affects carbon cycle and climate change. Accurately quantifying the carbon sink effect resulting from chemical weathering caused by anthropogenic H 2 SO 4 is imperative to improve the assessment of the global carbon budget. Nevertheless, there is still a lack of precise understanding regarding the impact of anthropogenic H 2 SO 4 on CO 2 consumption during chemical weathering. Here, spring water samples were collected monthly from three catchments with distinct bedrock lithologies affected by severe acid precipitation in Southwest China for analyses of hydrogeochemistry and δ13C DIC to quantitatively estimate the effect of anthropogenic H 2 SO 4 on the weathering carbon sink budget. The results show that carbonates contribute 97.4 %, 95.0 % and 88.8 % of the total cationic load using a straightforward method in the Beidiping carbonate catchment, as well as in the Shegengyan and Bianyan silicate catchments, respectively. The [Ca2++Mg2+]/[HCO 3 −] (0.98–1.19) and [Ca2++Mg2+]/[HCO 3 −+SO 4 2−] (approximately 1) equivalent ratios, and δ13C DIC values (−16.8 to −8.0 ‰) of the samples suggest that besides H 2 CO 3 , H 2 SO 4 is involved in carbonate weathering. The stoichiometry of the chemical compositions of spring water indicates that the presence of H 2 SO 4 enhances carbonate weathering rates by 14.8 %, 8.1 % and 7.5 % while decreasing the CO 2 consumption by 8.2 %, 4.3 % and 4.0 % in Beidiping, Shegengyan and Bianyan, respectively. Thus the reduced proportion of karst carbon sink in the carbonate catchment is approximately 2 times that in the silicate catchment, suggesting that carbonate weathering in the karst catchment is more sensitive to acid precipitation. The impact of acid precipitation on rock weathering in the silicate catchment is constrained by the soil buffering effect. Our study highlights the important role of anthropogenic H 2 SO 4 in carbonate weathering, which should be critically evaluated in regional and global carbon cycles in future studies. [ABSTRACT FROM AUTHOR]

The rapid development of the Internet of Things has promoted the application of wearable devices in human's daily life and industrialization. Strain sensors play an indispensable role as a member of wearable devices. Here, a strain film sensor with multi‐walled carbon nanotubes (MWCNTs) and Ti3C2TX MXene, which is obtained by vacuum‐assisted filtration and integrated onto a thermoplastic polyurethane substrate, is developed. Since the MWCNTs and Ti3C2TX MXene composite sensor has a characteristic 'mud‐brick' microstructure. The sensor has the ability to detect various human movements, such as, bending of finger joints, wrists, elbow joints, and shoulder. The sensors show excellent mechanical property and can be folded more than 2000 times without failure. It also exhibits short response time, low detection limit, and wide range of use. In addition, the sensor shows excellent electrical heating performance. The temperature of the composite film can rise to 96.6 °C in a short period of time even under low voltage power supply (25 V). It likewise proves its excellent performance in terms of cyclability and long‐time heating capability. The film has low production cost, easy preparation method, and simple operation. The MWCNT/Ti3C2TX MXene film can be integrated into wearable devices and shows great potential for future applications. [ABSTRACT FROM AUTHOR]

Holographic Teleportation is an emerging media application allowing people or objects to be teleported in a real-time and immersive fashion into the virtual space of the audience side. Compared to the traditional video content, the network requirements for supporting such applications will be much more challenging. In this paper, we present a 5G edge computing framework for enabling remote production functions for live holographic Teleportation applications. The key idea is to offload complex holographic content production functions from end user premises to the 5G mobile edge in order to substantially reduce the cost of running such applications on the user side. We comprehensively evaluated how specific network-oriented and application-oriented factors may affect the performances of remote production operations based on 5G systems. Specifically, we tested the application performance from the following four dimensions: (1) different data rate requirements with multiple content resolution levels, (2) different transport-layer mechanisms over 5G uplink radio, (3) different indoor/outdoor location environments with imperfect 5G connections and (4) different object capturing scenarios including the number of teleported objects and the number of sensor cameras required. Based on these evaluations we derive useful guidelines and policies for future remote production operation for holographic Teleportation through 5G systems. [ABSTRACT FROM AUTHOR]

The heat-storage strategy is effective to reduce the impact of essential solar radiation fluctuations on solar-driven thermochemical hydrogen production systems. However, synergy strategies and regulation methods for heat-storage processes and endothermic reaction processes are still needed. In this paper, novel heat-storage structures of different encapsulated phase change material (EPCM) and catalyst multi-zone filling methods are proposed, to improve dynamic performance of parabolic trough solar receiver-reactors (PTSRRs) with methanol steam reforming reactions. A three-dimensional dynamic model was developed for the corresponding optical-thermal-chemical and heat-storage mixing process, with realistic porosity distributions of both catalyst particle and EPCM capsule packed bed zones. After validation, this model was applied to investigate the corresponding synergy and regulation between endothermic reaction zones and heat storage zones under different fluctuating solar conditions. Comprehensive comparisons were made on impacts of EPCM capsule size, material and cascading method on dynamic performance of PTSRRs. Under the optimal strategy from comparisons, the delay response time is increased by 3.4 times under the step disappeared solar radiation fluctuation, while the relative vibration amplitude of the methanol conversion rate is reduced by 68 % under the periodic solar radiation fluctuation. It could provide guidance for similar solar-driven thermochemical systems under fluctuating solar radiations. [ABSTRACT FROM AUTHOR]

In marine environments, tidal currents exhibit periodic changes in both direction and velocity. Consequently, tidal turbines often operate under yawed conditions. While conventional horizontal-axis turbines show decreased performance and undergo periodic load fluctuations due to blade rotation when yawed, research on the effects of yaw on ducted turbines has been sparse, leaving the underlying impact mechanisms poorly understood. This paper presents a three-dimensional hydrodynamic model of a ducted turbine, developed using the computational fluid dynamics method and validated through flume experiments. The hydrodynamic characteristics of the ducted turbine when operating under yawed conditions are analyzed using large eddy simulation. The findings indicate that yaw does not alter the optimal rotational speed of the ducted turbine. The turbine performance remains superior to non-yawed conditions up to a yaw angle of approximately 7°, peaking with a 1% improvement at 5°, but deteriorates beyond this point, declining by 1.5% at a yaw angle of 10°. In addition, yaw causes a deflection in the wake of the ducted turbine. This deflection increases with the yaw angle, reaching its maximum at a yaw angle of 10° with an angle of about 3.4°, before diminishing. The duct structure significantly influences this deflection, while rotor rotation has a minimal impact on wake deflection. [ABSTRACT FROM AUTHOR]

C8H8N6·C5H9O2, monoclinic, I2/a (no. 15), a = 13.2666(17) Å, b = 11.0435(15) Å, c = 19.778(3) Å, β = 92.707(10)°, V = 2894.4(7) Å3, Z = 8, Rgt(F) = 0.0528, wRref(F2) = 0.1511, T = 293(2) K. [ABSTRACT FROM AUTHOR]

Machine learning is a powerful tool in finding hidden data patterns for quantum information processing. Here, we introduce this method into the optical readout of electron-spin states in diamond via single-photon collection and demonstrate improved readout precision at room temperature. The traditional method of summing photon counts in a time gate loses all the timing information crudely. We find that changing the gate width can only optimize the contrast or the state variance, not both. In comparison, machine learning adaptively learns from time-resolved fluorescence data and offers the optimal data processing model that elaborately weights each time bin to maximize the extracted information. It is shown that our method can repair the processing result from imperfect data, reducing 7% in spin readout error while optimizing the contrast. Note that these improvements only involve recording photon time traces and consume no additional experimental time, and they are, thus, robust and free. Our machine learning method implies a wide range of applications in the precision measurement and optical detection of states. [ABSTRACT FROM AUTHOR]

Over the past two decades, the development and application of ynamide chemistry have received more and more attention. Ynamides have proven to be versatile reagents for organic synthesis, and have been widely applied to the rapid assembly of a diverse range of structurally complex N-containing molecules, especially the valuable N-heterocycles. In comparison with the well-established transition metal-catalyzed reactions of ynamides, metal-free ynamide transformations have relatively seldom been exploited. Recently, Brønsted acid-mediated reactions of ynamides represent significant advances in ynamide chemistry. This review summarizes the latest trends and developments of Brønsted acid-mediated reactions of ynamides, including cycloaddition, cyclization, intramolecular alkoxylation-initiated rearrangement, oxygen atom transfer reactions and hydro-heteroatom addition reactions. [ABSTRACT FROM AUTHOR]

The sedimentologic fingerprinting in detrital deposit is vital to reconstruct sedimentary environments and discriminate sources. In this study, grain size and microtextural characteristics of quartz from the late Pleistocene hard clay in the Yangtze River delta (YRD) were analyzed by using a laser particle size analyzer and a scanning electron microscope. Subaqueous quartz from the Yangtze River and Yellow River sediments and eolian quartz from the Chinese Loess Plateau loess were also analyzed by scanning electron microscopy to obtain the microtextural characteristics. Quartz grains of the hard clay were characterized by poor sorting, fine skew, bimodal grain-size distributions, and numerous eolian microtextures. The comparison of the quartz grain characteristics of the hard clay with these in eolian loess indicated that the hard clay belonged to an eolian deposition. Moreover, the fine quartz grains of the hard clay were dominated by eolian microtextural characteristics, representing long-distance transportation. The coarse quartz grains of the hard clay exhibited more subaqueous microtextural characteristics, which indicated that the coarse fraction of the hard clay was derived from the proximal source regions in the YRD. The determination of buried eolian deposition with multiple sources in the YRD implies a southward westerly jet stream, strengthened eolian dust transportation, and extensive aridification in the YRD due to the increased Northern Hemisphere ice sheets in Marine Oxygen Isotope Stage 2. [ABSTRACT FROM AUTHOR]

Background: Cytochrome P450 (CYPs) participate in the mechanisms of cardiovascular disease. The purpose of this research was to evaluate the contributions of CYP24A1 variants to coronary heart disease (CHD) among the Chinese Han population. Methods: This study included 505 CHD cases and 508 controls. Four variants of CYP24A1 (rs2762934, rs1570669, rs6068816 and rs2296241) were chosen and genotyped by the Agena MassARRAY system among the Chinese population. The linkage between CYP24A1 variants and CHD risk were assessed by logistic regression to compute the odds ratio (OR) and 95% confidence interval (CI). Then, multifactor dimensionality reduction (MDR) was applied to analyze the interactions of CYP24A1 variants. Results: The results of this study showed that CYP24A1 rs6068816 significantly enhanced CHD risk in multiple genetic models (allele: P = 0.014; codominant: P = 0.015; dominant: P = 0.043; recessive: P = 0.040; additive: P = 0.013), whereas rs2296241 was likely to protect individuals from CHD (codominant: P = 0.019; recessive: P = 0.013; additive: P = 0.033). Stratification analysis revealed that CYP24A1 polymorphisms had strong relationships with CHD risk that were dependent on age, sex, Gensini grade and smoking status (P < 0.05). Moreover, a four-locus model (rs2762934, rs1570669, rs6068816 and rs2296241) had significant impact on CHD risk in MDR analysis. Conclusion: It revealed that CYP24A1 variants were significantly linked with CHD susceptibility in the Chinese population. [ABSTRACT FROM AUTHOR]

An effective method via tensor decomposition is proposed to deal with the joint direction-of-departure (DOD) and direction-of-arrival (DOA) estimation of noncircular sources in colocated coprime MIMO radar. By decomposing the transmitter and receiver into two sparse subarrays, noncircular property of source can be used to construct new extended received signal model for two sparse subarrays. The new received model can double the virtual array aperture due to the elliptic covariance of imping sources is nonzero. To further exploit the multidimensional structure of the noncircular received model, we stack the subarray output and its conjugation according to mode-1 unfolding and mode-2 unfolding of a third-order tensor, respectively. Thus, the corresponding extended tensor model consisted of noncircular information for DOA and DOD can be obtained. Then, the higher-order singular value decomposition technique is utilized to estimate the accurate signal subspace and angular parameter can be automatically paired via the rotational invariance relationship. Specifically, the ambiguous angle can be eliminated and the true targets can be achieved with the aid of the coprime property. Furthermore, a closed-form expression for the deterministic CRB under the NC sources scenario is also derived. Simulation results verify the superiority of the proposed estimator. [ABSTRACT FROM AUTHOR]

The relationship between the long noncoding RNA (lncRNA) expression and oesophageal cancer prognosis has been widely studied, but less consensus has been reached. We conducted this study to evaluate the relationship between the expression of lncRNAs and the prognosis and clinical pathology of oesophageal cancer. We conducted a systematic search of PubMed, EMBASE and Cochrane Library until 25 January 2019. Studies that evaluated the associations of a specific lncRNA with survival and/or clinicopathology of oesophageal cancer were included. Pooled hazard ratios (HRs), odds ratios (ORs), and corresponding 95% confidence intervals (CIs) were calculated using fixed or random-effect models. Sensitivity analysis was used to verify the stability of results. Publication bias was detected using Begg tests and adjusted utilizing the trim-and-fill method if a bias existed. A total of 51 studies comprising 6510 patients and regarding 41 lncRNAs were included in the present systematic review and meta-analysis. The results showed that dysregulation of lncRNAs was associated with overall survival, disease-free survival, and progression-free survival. The expression of lncRNAs was related to some certain clinicopathological parameters of oesophageal cancer, including tumour size, T classification, lymph node metastasis, tumour node metastasis (TNM) stage and differentiation. Among these findings, lncRNA AK001796, CASC9, HOTAIR, MALAT1 and UCA1 were identified and were expected to be ideal biomarkers for the prognosis and clinicopathology of oesophageal cancer. Although significant publication bias was observed in some studies, the results were not changed after adjustment using the trim-and-fill method. Abnormal lncRNA-expression profiles could serve as a promising indicator for prognostic evaluation of patients with oesophageal cancer. The combination of these lncRNAs will contribute to clinical decision-making in the future. [ABSTRACT FROM AUTHOR]

To improve flammability and radiation efficiency, a divergent porous media combustor is proposed and numerically studied. The local thermal non-equilibrium model is used to consider the temperature difference between gas and solid matrix. Effects of equivalence ratio, the wall thermal conductivity, solid matrix thermal conductivity, and divergent ratio on combustion characteristics, radiation efficiency, and flammability limits are studied. The results show that the divergent channel extends the blowout limit by 186% and obtains a maximum radiation efficiency of 29.3%, increased by 70% compared with the straight channel. A smaller wall thermal conductivity is recommended considering the flammability range and radiation efficiency. A careful choice of solid matrix thermal conductivity and the divergent ratio is suggested to balance their opposing effects on the radiation efficiency and the flammability. • A divergent channel is proposed to improve the performance of the MTPV system. • The divergent channel promotes the blowout limit by 186%. • A smaller wall thermal conductivity is recommended. [ABSTRACT FROM AUTHOR]

In the study, magnesium oxide (MgO) was used to catalyze peroxymonosulfate (PMS) for the degradation of organic pollutants for the first time. According to the single-factor experiment results, it was determined that MgO could efficiently catalyze PMS to degrade organic matters in a wide range of pH values. Based on radical quenching experiments and electron spinning resonance spectra, singlet oxygen was identified to be the crucial reactive species. Importantly, the oxygen vacancy on the surface of MgO was determined as the key active site, which accelerated the decomposition of PMS to produce singlet oxygen. This study provides an interesting insight into the novel and ignored catalyst of MgO for the highly efficient activation of PMS, which will greatly benefit the Fenton-like catalytic degradation of organic wastewater. [ABSTRACT FROM AUTHOR]

This paper presents data-driven approaches to improve the active power output of wind turbines based on estimating their health condition. The main procedure includes estimations of fault degree and health condition level, and optimal power dispatch control. The proposed method can adjust the active power output of individual turbines according to their health condition and can thus optimize the total energy output of a wind farm. In the paper, extreme learning machine algorithm and Bonferroni interval are applied to estimate fault degree, while an analytic hierarchy process is used to estimate the health condition level. A scheme for power dispatch control is formulated based on the estimated health condition. Models have been identified from supervisory control and data acquisition data acquired from an operational wind farm, which contains temperature data of gearbox bearing and generator winding. The results show that the proposed method can maximize the operation efficiency of the wind farm while significantly reducing the fatigue loading on the faulty wind turbines. [ABSTRACT FROM AUTHOR]

Duschinsky rotation effect is a simple and effective way to characterize the difference between the ground state and excited state potential energy surfaces. For complex molecules, harmonic oscillator model is still the practical way to describe the dynamics of excited states. Based on the first-order perturbation theory à la Fermi golden rule, the authors have applied the path integral of Gaussian type for the correlation function to derive an analytic formalism to calculate the internal conversion rate process with Duschinsky rotation effect being taken into account. The validity of their formalism is verified through comparison with previous work, both analytically for the case of neglecting Duschinsky rotation and numerically for the ethylene molecules with two-mode mixing. Their expression is derived for multimode mixing. [ABSTRACT FROM AUTHOR]

• A feature-compressed multi-task learning U-Net with CBAM (MTL-UNET-CBAM) for shallow-water source localization with the presence of internal waves is constructed. • CBAM improves range localization performance of MTL-UNET, but has no significant improvement on depth estimation. • MTL-UNET-CBAM has higher localization robustness and computation speed then CMFP. • Applying DTL to MTL-UNET-CBAM significantly improve the localization performance of MTL-UNET-CBAM on both range and depth estimation. The spatiotemporal variation of sound speed profile caused by internal waves usually causes the mismatch in the Matched-Field Processing (MFP) source localization. A feature-compressed multi-task learning U-Net with Convolutional Block Attention Module (MTL-UNET-CBAM) is proposed to estimate the range and depth of underwater sources in the South China Sea environment with the presence of internal waves. To handle the mismatch caused by internal waves, the temperature sensor chain data are used to reconstruct the two-dimensional sound speed profiles (2D-SSPs) based on the 2D advection model. Then, 2D-SSPs are used to generate the training set with the parabolic equation method. Sensitivity analysis is investigated to examine the effects of sound speed profile mismatch on the source localization performance. The simulation result shows the higher robustness of MTL-UNET-CBAM to the sound speed profile mismatch compared with the conventional Matched-Field Processing (CMFP) method. Experiment data in the South China Sea also used to validate the source localization performance of MTL-UNET-CBAM. [ABSTRACT FROM AUTHOR]

The potential energy surfaces have been constructed for the 1A′, 3A′, and 3A″ states of HBO by using the multireference perturbation theory with the basis set cc-pVTZ (6d,10f ). Two stationary points and a transition state have been characterized on all the three surfaces, which are in good agreement with available experiments and previous calculations. The interconversion pathways from metastable boron hydroxide BOH to the considerably more stable HBO are expounded based on the nature of the surfaces. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Abstract Tidal current turbine, as an effective technical means to contribute to all around the world achieving targets for reducing greenhouse gas emissions and the production of renewable energy, has obtained great concern. It was established that more than 94 TWh per year could be generated in the developable sea area. Many types of tidal current turbine structures and control methods have been proposed, however, the possible increase in power generation must consider parameters such as reliability, cost, and complexity of the control system. The paper presents a review on configuration and control methods of tidal current turbines. The configuration and control methods of tidal current turbines are classified, described and compared, especially for horizontal axis tidal current turbines. Horizontal axis tidal current turbine is more widely used, due to high energy conversion efficiency. Different configuration and corresponding control methods have their advantages and disadvantages, which affect efficiency, maintenance requirements, and the cost of electricity from tidal current. Highlights • The configuration of the main tidal current turbines is detailed. • The structure of horizontal axis tidal current turbine is described. • The control methods of horizontal axis tidal current turbine are illustrated. [ABSTRACT FROM AUTHOR]

Pyruvic acid is an important chemical in the carboxylate platform. Obstacles for its implementation are the need for high energy in chemical synthesis and additives in fermentation leading to increased production costs. Here, pyruvic acid generation from direct conversion of lactic acid in fermentation broth by electrolysis method is presented. It was found that lactic acid could be converted to pyruvic acid in the electrolysis cell under alkaline conditions. Using 12.53 g/L lactic acid fermentation broth as anolyte, 7.01 g/L pyruvic acid could be produced and productivity to lactic acid was 57.66% at initial pH 11.74 and 5.0 V applied a voltage in the electrolysis cell. Meanwhile, 0.472 mol hydrogen was produced at the cathode. The electric energy efficiency was 76.18%. Lactic acid fermentation is relatively cheap and can be performed on many kinds of wastes and biomasses. The results suggest that pyruvic acid production from direct electrolysis of lactic acid fermentation broth can be economically feasible. [ABSTRACT FROM AUTHOR]

The integration and permeability of the interface between concrete layers of a dam considerably affect its structural functionality and safety. To understand the interface properties, several tests were conducted to examine the various characteristics of specimens with different layer interfaces. The mechanical property in terms of bond strength was assessed using the splitting tensile test, which was affected by interval time. On the other hand, the ultrasonic pulse test was used to confirm the influence of the interface on ultrasonic attenuation. The chloride and water permeability were also investigated by means of the rapid chloride permeability, alternating current resistance, and water permeability tests. The results of these tests proved that longer interval times lead to a weaker bond strength and higher permeability, which are harmful to layer structures. The change rules of mechanical and permeability properties were confirmed by the optical micrograph and hardness distribution of the overlay transition zone. Finally, the relationships among these tests were analyzed, and strong correlations demonstrated that the non-destructive ultrasonic pulse test and rapid electrical test could be employed to predict and evaluate the bond strength and permeability of a layered interface. [ABSTRACT FROM AUTHOR]

Shunt active power filters (SAPFs) have been widely used to improve power quality of the grid by mitigating harmonics injected from nonlinear loads. This paper presents a new method for improving the performance of SAPFs using neutral-point-clamped (NPC) three-level inverters. NPC three-level inverters often suffer excessive voltage fluctuations at the neutral-point of DC-link capacitors, which may damage switching devices and cause additional high harmonic distortion of the output voltage. In order to solve the problem, two compensating schemes are proposed to restrict voltage fluctuation in the inverters. The first is voltage dependent, adopting a voltage compensation method, while the second is current dependent, using a current compensation method. The paper describes the respective circuit architectures and principles of operation. Corresponding models are mathematically formulated and evaluated under typical balanced and unbalanced working load conditions. The results show that both schemes are able to alleviate considerably voltage oscillations and hence harmonic distortions, and the current-compensated NPC inverter outperforms the voltage-compensated NPC inverter. Consequently, it is shown that the proposed approaches are effective and feasible for improving power quality of the grid when connected to nonlinear loads. [ABSTRACT FROM AUTHOR]

The discharge of heavy metal ions such as Cu 2 + and Pb 2 + poses a severe threat to public health and the environment owing to their extreme toxicity and bioaccumulation through food chains. Herein, we report a novel organic–inorganic hybrid adsorbent, Al(OH) 3 -poly(acrylamide-dimethyldiallylammonium chloride)-graft-dithiocarbamate (APD), for rapid and effective removal of Cu 2 + and Pb 2 + . In this adsorbent, the “star-like” structure of Al(OH) 3 -poly(acrylamide-dimethyldiallylammonium chloride) served as the support of dithiocarbamate (DTC) functional groups for easy access of heavy metal ions and assisted development of large and compact floccules. The synthesized adsorbent was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). APD was demonstrated to have rapid adsorption kinetics with an initial rate of 267.379 and 2569.373 mg/(g·min) as well as superior adsorption capacities of 317.777 and 586.699 mg/g for Cu 2 + and Pb 2 + respectively. The adsorption process was spontaneous and endothermic, involving intraparticle diffusion and chemical interaction between heavy metal ions and the functional groups of APD. To assess its versatility and wide applicability, APD was also used in turbid heavy metal wastewater, and performed well in removing suspended particles and heavy metal ions simultaneously through flocculation and chelation. The rapid, convenient and effective adsorption of Cu 2 + and Pb 2 + gives APD great potential for heavy metal decontamination in industrial applications. [ABSTRACT FROM AUTHOR]

Objective: To explore the effect and mechanism of artesunate on γδ T cell-mediated antitumor immune responses against hepatoma carcinoma cells (HepG2) in vitro. Methods: Human γδ T cells or HepG2 were respectively treated with artesunate, subjected to co-culture as appropriate, and the following assays were subsequently conducted: CCK8 to examine cell viability; LDH release assay to detect the killing effect of γδ T cells on HepG2 cells; flow cytometry to examine the expression of perforin (PFP) and granzyme B (GraB) of γδ T cells; ELISA to evaluate the levels of TGF-β1 and IL-10 in the collected supernatant of HepG2 cells pretreated with artesunate; and Western blot analysis to examine Fas, FasL, STAT3, p-STAT3 expression of HepG2 cells induced by artesunate.  Results: The results showed that the cytotoxicity effect of γδ T cells pretreated with artesunate on HepG2 cells was augmented via elevating the expression of GraB in γδ T cells. Furthermore, treatment with artesunate reversed the inhibition of HepG2 cells on γδ T cells by reducing the secretion of TGF-β1 in HepG2 cells supernatant and enhanced the antitumor effect of γδ T cells against HepG2 cells through increasing the expression of Fas on HepG2 cells, which may be attributed to the inhibition of STAT3 signaling protein. Conclusion: Artesunate has several mechanisms for augmenting the antitumor immune responses mediated by γδ T cells. These results suggested artesunate may be an efficacious agent in the treatment of hepatocellular carcinoma. [ABSTRACT FROM AUTHOR]

The article offers information on a study which examined asymmetric photon transport and directional light propagation in single-crystal organic semiconductor nanowires using electrically controlled exciton diffusion. A physical vapor transport technique was used to obtain 9,10-bis(phenylethynyl)anthracene (BPEA) nanowire crystals. It shows that electrotunable asymmetric optical outcoupling was accomplished by modifying direction and field strength.

Oxidative stress and apoptosis serve an essential role in cisplatin-induced cardiotoxicity, which limits its clinical use, and increases the risk of cardiovascular disease. As a natural drug, the antioxidant and antitumor effects of cyanidin have been recognized, but its protective effect on cisplatin-induced cardiomyocyte cytotoxicity remains unclear. H9c2 cells were treated with cisplatin (1-40 µM) in the presence or absence of cyanidin (40-80 µM), subsequently; oxidative stress, apoptosis and mitochondrial function were assessed using several techniques. The results demonstrated that cyanidin was able to dose-dependently reverse cisplatin-induced cell damage and apoptosis, attenuate the accumulation of reactive oxygen species (ROS), and mitochondrial membrane potential depolarization, downregulate the expression of Bcl-2 homologous antagonist/killer, upregulate the expression of apoptosis regulator Bcl-2, and reduce the activation of caspase 3, caspase 9, but not caspase 8. Furthermore, the results revealed that the translocation of apoptosis regulator Bax (Bax) from the cytoplasm to the mitochondrial membrane serves an essential role in cisplatin-induced apoptosis. Cyanidin was able to block the translocation of Bax and reduce the release of cytochrome c from cytoplasm. These data indicate that cyanidin attenuates cisplatin-induced cardiotoxicity by inhibiting ROS-mediated apoptosis, while the mitochondrial and extracellular regulated kinase signaling pathways may also serve important roles. [ABSTRACT FROM AUTHOR]

A facile and efficient approach to phosphinic amides was developed from diarylphosphine oxides and amines via electrosynthesis. A variety of phosphinic amides were obtained in one step with good to excellent yields under mild and metal-free conditions. The corresponding mechanism was investigated. [ABSTRACT FROM AUTHOR]

The widely used approach of mesoscale finite element modeling for permeability analysis is to simulate the matrix and cracks with continuum elements (CE), whereas this process brings technical difficulties in generating a satisfying mesh conformity at the interface. In this work, an alternative method based on embedded element (EE) technique is developed for the prediction of water pressure field and effective permeability in the numerical simulation. Based on the mathematical similarity between elasticity and seepage problems, water pressure can derive from the corresponding displacement through “elastic analogy.” To assess the capability of the EE technique, different cases are simulated and compared with the CE model. The results show that there is a satisfactory agreement in water pressures and velocities between the CE and EE modeling. In the CE model, different factors, such as permeability contrast between matrix and cracks (Kcrack/Kmatrix) and mesh size, are considered. It is obvious to find that results will become stable when Kcrack/Kmatrix reaches 104, and the mesh size has little impact. The effective permeability of 3D porous media with random cracks is evaluated and the results show that the differential method is accurate for 3D permeability analysis when the crack density is not large. [ABSTRACT FROM AUTHOR]

Theoretical understanding of organic light-emitting diodes started from the quest to the nature of the primary excitation in organic molecular and polymeric materials. We found the electron correlation strength, bond-length alternation as well as the conjugation extent have strong influences on the orderings of the lowest lying excited states through the first application of density matrix renormalization group theory to quantum chemistry. The electro-injected free carriers (with spin 1/2) can form both singlet and triplet bound states. We found that the singlet exciton formation ratio can exceed the conventional 25% spin statistics limit. We proposed a vibration correlation function formalism to evaluate the excited-state decay rates, which is shown to not only give reasonable estimations for the quantum efficiency but also a quantitative account for the aggregation-induced emission (AIE). It is suggested to unravel the AIE mechanism through resonance Raman spectroscopy. [ABSTRACT FROM AUTHOR]

It is of vital importance to theoretically understand unique nanoparticle size-tunable and excitation wavelength-dependent multiple optical properties in organic nanoparticles. In this work, we proposed a theoretical protocol to calculate the optical spectrum of the organic nanoparticles, which combines molecular dynamics (MD) simulation, the quantum mechanics/molecular mechanics (QM/MM) approach, and vibronic-coupled Frenkel exciton spectrum theory. By using the protocol, we explored the relationship between intramolecular structure distortion, irregular intermolecular packing, and optical spectra in α-sexithiophene nanoparticles. Two representative clusters cutting from the simulated amorphous nanoparticle were investigated and found to exhibit a blue shift for absorption and emission spectra compared to the solution, which is totally different from the blue-shifted absorption and red-shifted emission in crystal. For the cluster with distorted monomer and disordered packing, the blue shift results from the higher excitation energy and larger vibronic coupling of low-frequency vibration modes, while for the cluster with planar monomer and ordered packing, the blue shift is induced by the synergism of vibronic coupling and excitonic coupling. Strikingly, the superposition of the spectra of two clusters reproduces the experimental spectra and well explains the unusual blue-shifted emission observed for α-sexithiophene nanoparticles. Our theoretical protocol is general and applicable to other organic nanoparticles, thus aiding the rational design of high-quality organic nanoparticles. [ABSTRACT FROM AUTHOR]

C31H42Br2N4Pd, monoclinic, P21/ c, a = 12.3093(14)Å, b = 15.2805(18) Å, c = 20.3205(17) Å, β = 112.213(5)°, V = 3538.5(7) Å3, Z = 4, Rgt( F) = 0.0540, wRref( F2) = 0.1528, T = 298(2)K. [ABSTRACT FROM AUTHOR]

In order to overcome the shortcoming of high resistance of liquid metal flow, three new types of microchannel heat sinks, namely top-slotted microchannel, bottom-extension microchannel and composite microchannel are proposed, and the flow and heat transfer characteristics of liquid metal galinstan are numerically studied. It is found that all three new microchannel heat sinks can reduce the flow resistance effectively. The optimized geometric structure is obtained by analyzing the effect of geometry parameters on total thermal resistance and pump power, including the slot height, the length of extension area, the distance from the entrance to the extension point and the extension height. The lowest flow resistance is obtained in the composite microchannel and the pump power is 54.9% lower than that of the traditional channel with only 0.7% increase of total thermal resistance. Based on the geometry parameter of the slot height, the distance from the entrance to the extension point and the extension height, two factors are proposed to revise the empirical correlation of friction factor f for the top-slotted and bottom-extension channel. The corrected results are in good agreement with the numerical results. • Three new types of microchannel heat sinks are studied for liquid metal coolant. • Optimized geometric structure is obtained and the pump power reduced 54.9%. • The empirical correlation of friction factor f is corrected. [ABSTRACT FROM AUTHOR]

A silver-mediated cascade trifluoromethylthiolation and cyclization has been developed for the synthesis of 2-(trifluoromethylthio)-indenones. A variety of arylpropynones underwent this radical oxidative cyclization with AgSCF 3 to afford trifluoromethylthiolated indenones in moderate to excellent yields. [ABSTRACT FROM AUTHOR]

Objective: The study aimed to assess the clinical efficacy of breathing training combined with core stability training in chronic nonspecific low back pain (CNLBP). Methods: This was a retrospective study. Of 60 included patients with CNLBP admitted by the Sichuan Province Orthopedic Hospital between December 2020 and February 2022. Random number table method was used to divide thirty patients to a control group, and the rest 30 to an observation group. The control group received core stability training, while the observation group underwent breathing training in addition to the exact treatment provided for the control group. To assess the utility of breathing and core stability training for CNLBP treatment, intergroup comparisons were made for clinical outcomes, the VAS, SF-36, and SCODI scores before treatment and at three and seven weeks post-treatment, and static and dynamic low-back muscular endurance before and after treatment. Results: The observation group had an overall response rate (ORR) of 96.67%, significantly higher than that (73.33%) of the control group (p< 0.05). Following the intervention, the VAS and SCODI scores declined in both groups; The SF-36 score was elevated in both groups, and likewise. At the end of treatment, both groups exhibited improved static and dynamic muscular endurance of the low back, and the improvement was significantly more distinct in the observation group (p< 0.05). Conclusion: Compared with core stability training as a sole treatment, breathing training combined with core stability training can yield better outcomes, ameliorate lumbar spine function, relieve pain and enhance low-back muscular endurance in patients with CNLBP. [ABSTRACT FROM AUTHOR]

Accurate and reliable tidal current forecasting plays a key role in application of grid-connected tidal current power generation systems. Hence, a novel tidal current prediction method based on a hybrid machine learning method is proposed in this paper. Compared with previous tidal current prediction method, the proposed tidal current prediction method considers the influence of turbulence on multi-layer tidal velocity difference. A hybrid machine learning method based on hierarchical extreme learning machine(H-ELM) and long short-term memory (LSTM) is adopted to reduce effect of the turbulent flow, which enables to increase the accuracy of the prediction result. The tidal data that collected by using acoustic doppler current profiler (ADCP) in Zhejiang province China is used to validate the effectiveness of the proposed method. The results of the case study show that the proposed method has higher accuracy than results from standard harmonic analysis using UTide (a freely available academic research product). • A novel tidal current prediction model considering the multilayer difference caused by the turbulent flow is proposed. • A hybrid machine learning method is adopted to reduce effect of the turbulent flow and increase the prediction accuracy. • Both H-ELM and LSTM methods are applied in the short-term tidal current velocity prediction. [ABSTRACT FROM AUTHOR]

The sailing performance of an S-type small waterplane area twin hull (S-SWATH) vehicle, which has comparable total resistance at low and high speeds, in waves is investigated. A flapping foil stabiliser is proposed to enhance the seakeeping advantages of the vehicle in rough waves. The unsteady hydrodynamic characteristics of the flapping foil stabiliser are investigated, and its working mechanism is modelled based on the data generated using the computational fluid dynamics method with fixed-grid technology. Compared with a conventional fin, the results show the benefits of the flapping foil with relatively higher lift coefficients and lower drag coefficients. The vertical plane motion control model coupled with the mathematical force model of flapping foils is built. A controller combining the model predictive control scheme with input disturbance measurement is designed to compare the performance of the conventional fins and flapping foils in stabilising the heave–pitch motions of the vehicle. For the simulations, the hydrodynamic coefficients of the vehicle and the wave force–moment on S-SWATH are updated based on Salvesen, Tuck and Faltinsen strip theory, which is equivalent to measuring the approaching wave elevation directly. The flapping foil stabilisers show significant improvements in damping the heave–pitch motions of the vehicle in rough seas. [ABSTRACT FROM AUTHOR]

Conspectus: This Account describes the use of quantum-chemical calculations to elucidate mechanisms and develop catalysts to accomplish highly selective cyclization reactions. Chemistry is awash with cyclic molecules, and the creation of rings is central to organic synthesis. Cyclization reactions, the formation of rings by the reaction of two ends of a linear precursor, have been instrumental in the development of predictive models for chemical reactivity, from Baldwin's classification and rules for ring closure to the Woodward and Hoffmann rules based on the conservation of orbital symmetry and beyond. Ring formation provides a productive and fertile testing ground for the exploration of catalytic mechanisms and chemo-, regio-, diastereo-, and enantioselectivity using computational and experimental approaches. This Account is organized around case studies from our laboratory and illustrates the ways in which computations provide a deeper understanding of the mechanisms of catalysis in 5-endo cyclizations and how computational predictions can lead to the development of new catalysts for enhanced stereoselectivities in asymmetric cycloisomerizations. [ABSTRACT FROM AUTHOR]

The concentration distribution of droplets in liquid-liquid hydrocyclones was studied using a phase Doppler particle analyzer. The effect of cone angle and inlet flow flux on the concentration distribution of droplets was determined. The cone angle of the hydrocyclone obviously influenced the maximum droplet concentration, especially that in the cone section. The hydrocyclone with a cone angle of 6° presented the best separation result. A higher inlet flow rate enhanced the separation of droplets from the water. The concentration profiles at five different axial heights presented a parabola law pattern in the radial direction. The optimized hydrocyclone was applied for the dewatering of vinyl chloride monomer (VCM). The amount of residual water could be greatly reduced. [ABSTRACT FROM AUTHOR]

The increasing incidence of male reproductive impairments has been associated with di-(2-ethylhexyl)-phthalate (DEHP) exposure. However, mechanisms involved are lacking. We exposed 4-week-old male C57BL/6j mice to DEHP by gavage at 0, 125, 250 or 500 mg/kg body weight/day for 28 consecutive days. Our data showed that pubertal exposure to DEHP induces sperm count reduction as well as histological abnormalities in seminiferous epithelium and apoptosis of post-meiotic germ cells, and these effects are concomitant with reduction of testosterone levels and its steroidogenic gene expression. Moreover, the expressions of estrogen receptor ERβ and nuclear receptors Nr0b1, Nr0b2 are increased. The expression of Nr5a2 which is the inducer of steroidogenesis is significantly reduced. Furthermore, spermatogonial stem cell (SSC) self-renewal, differentiation and meiosis were significantly impaired, and the epigenetic regulator G9a-mediated histone methylation was decreased following DEHP exposure. Our results suggest that the DEHP-induced male reproductive impairments may depend on its estrogenic action on estrogen receptor and nuclear receptor, and involve inhibition of steroidogenesis, SSC self-renewal and meiosis, which may be attributed to the down-regulation of G9a-mediated histone methylation. [ABSTRACT FROM AUTHOR]

The experimental results of three full-scale two-story, two-bay, composite steel frames under furnace loading are described briefly. During tests, the composite beams and steel columns were exposed to fire, and only the beam-to-column connections of the tested frames were protected. The furnace temperature, composite steel beam temperature, steel column temperature, horizontal displacements of the columns, and vertical deflections of the composite beams as well as the complete deformation process of the test frames observed during the heating phase and the cooling phase are given. By introducing the slope-deflection equations and joint equilibrium conditions at each joint, the critical temperatures of the buckling of two-story, two-bay, composite steel frames are determined for different furnace scenarios; therefore, this method can consider the effect of the axial force at different levels. The calculated critical temperatures agree well with the experimental results. [ABSTRACT FROM AUTHOR]

BACKGROUND: The Hedgehog (Hh) signaling pathway has recently been reported to be associated with the prognosis of digestive system cancers. However, the results are inconsistent. OBJECTIVE: This study aimed to investigate the association between Hh pathway components and survival outcomes in patients with digestive system cancers. METHODS: We conducted a comprehensive retrieval in PubMed, EMBASE and Cochrane library for relevant literatures until May 1st, 2015. The pooled hazard ratios (HRs) for overall survival (OS) and disease-free survival (DFS) with 95% confidence intervals (CIs) were calculated to clarify the prognostic value of Hh pathway components, including Shh, Gli1, Gli2, Smo and Ptch1. RESULTS: A total of 16 eligible articles with 3222 patients were included in the meta-analysis. Pooled HR suggested that over-expression of Shh and Gli1 were both associated with poor OS (HR = 1.87, 95% CI: 1.14-3.07 and HR = 1.96, 95% CI: 1.66-2.32, respectively) and DFS (HR = 2.37, 95% CI: 1.19-4.72 and HR = 2.18, 95% CI: 1.61-2.96, respectively). In addition, over-expression of Smo was associated with poor DFS (HR = 1.38, 95% CI: 1.08-1.75). CONCLUSIONS: This study reveals that over-expressed Hh pathway components, including Shh, Gli1 and Smo, are associated with poor prognosis in digestive system cancer patients. Hh signaling pathway may become a potential therapeutic target in digestive system cancers. [ABSTRACT FROM AUTHOR]

Increasingly, urban and high speed trains are incorporating tables (workstations) as common railway vehicle interior furniture because passengers prefer seating by bay tables. Among table design characteristics, the most challenging is meeting crashworthiness requirements. Past accident data and sled test results have shown that in the event of railway vehicle frontal impact, occupants located in the bay seating are exposed to chest and abdominal injuries upon contact with tables resulting from secondary collision. In some cases tables have tended to be structurally weak; they easily detach from the side walls and/or floor mounting. Subsequently these become unguided missiles that strike occupants, resulting in injuries. This paper presents an analysis of the crash performance of a typical bay table. The results provide some understanding of the table’s crash safety, giving an indication of its impact aggression. Table materials are characterised using quasi-static compressive tests. In addition, experimental dynamic (impact) tests are conducted using a pendulum representing a body block (mass). The results provide information about the possible loading of the table on the occupant in the event of a crash. Contact forces are compared with chest and abdominal injury tolerance thresholds to infer the collision injury potential. Recommendations are then made on design of bay tables to meet the “functional-strength-and-safety balance”. [ABSTRACT FROM AUTHOR]

A mild and efficient method to selectively cleave p -methoxybenzyl (PMB) ether with a catalytic amount of Co 2 (CO) 8 , hydrosilane and CO (1 atm) is presented. The cleavage reaction shows regioselectivity to primary O -PMB of a variety of permethoxybenzylated saccharides and chemoselectivity to O -Bn, sulfur-containing group and common ester protecting groups. [ABSTRACT FROM AUTHOR]

A new, metal-free method for the formation of C(sp3)-O bonds was established by PhI(OAc)2-mediated oxygenation of benzylic C(sp3)-H bonds with N-hydroxyamides at room temperature, in which the C(sp3)-H oxidation is activated by a polyflurophenylamide group. [ABSTRACT FROM AUTHOR]