Search

This study takes the mine wall of the isolated mine pillar in the Dongguashan Copper Mine as the research object. Based on the mechanical model of the mine wall under the trapezoidal loading of the backfill, the expressions for calculating the safety factor of the mine wall were derived by considering the load-bearing conditions of the backfill–mine-wall system under different roof-contacted filling rates. On this basis, the variation law of the safety factor of the mine wall with the roof-contacted filling rate was obtained, and the calculation result was verified by a numerical simulation and a field test. The research shows that for the same mine wall width, when the roof-contacted filling rate exceeds 9.53%, the safety factor of the mine wall exhibits a "trapezoidal" variation pattern with the increase in the roof-contacted filling rate. Moreover, the comprehensive benefits of isolated pillar recovery are made more credible by maintaining a wall width of 3 m and a filler jointing rate between 30% and 74.49%. This study analyzes the effect of the roof-contacted filling rate on the stability of the mine wall, which can provide a theoretical basis for mining isolated pillars by the filler method in deep mines. [ABSTRACT FROM AUTHOR]

L-leucine is an essential amino acid widely used in food and pharmaceutical industries. However, the relatively low production efficiency limits its large-scale application. In this study, we rationally developed an efficient L-leucine-producing Escherichia coli strain. Initially, the L-leucine synthesis pathway was enhanced by overexpressing feedback-resistant 2-isopropylmalate synthase and acetohydroxy acid synthase both derived from Corynebacterium glutamicum , along with two other native enzymes. Next, the pyruvate and acetyl-CoA pools were enriched by deleting competitive pathways, employing the nonoxidative glycolysis pathway, and dynamically modulating the citrate synthase activity, which significantly promoted the L-leucine production and yield to 40.69 g/L and 0.30 g/g glucose, respectively. Then, the redox flux was improved by substituting the native NADPH-dependent acetohydroxy acid isomeroreductase, branched chain amino acid transaminase, and glutamate dehydrogenase with their NADH-dependent equivalents. Finally, L-leucine efflux was accelerated by precise overexpression of the exporter and deletion of the transporter. Under fed-batch conditions, the final strain LXH-21 produced 63.29 g/L of L-leucine, with a yield and productivity of 0.37 g/g glucose and 2.64 g/(L h), respectively. To our knowledge, this study achieved the highest production efficiency of L-leucine to date. The strategies presented here will be useful for engineering E. coli strains for producing L-leucine and related products on an industrial scale. [Display omitted] • Systems metabolic engineering for L-leucine was applied in Escherichia coli. • High-level and -yield production of L-leucine was achieved. • The nonoxidative glycolysis pathway improved the acetyl-CoA pool and L-leucine yield. • TCA cycle was dynamically modulated to redistribute flux toward L-leucine synthesis. • The redox flux was improved by substituting the NADPH-dependent enzymes. [ABSTRACT FROM AUTHOR]

Effective assessment of catalytic performance is the foundation for the rational design and development of new catalysts with superior performance. The ubiquitous screening/optimization studies use reaction yields as the sole performance metric in an approach that often neglects the complexity of the catalytic system and intrinsic reactivities of the catalysts. Using an example of hydrogenation catalysis, we examine the transient behavior of catalysts that are often encountered in activation, deactivation and catalytic turnover processes. Each of these processes and the reaction environment in which they take place are gradually shown to determine the real-time catalyst speciation and the resulting kinetics of the overall catalytic reaction. As a result, the catalyst performance becomes a complex and time-dependent metric defined by multiple descriptors apart from the reaction yield. This behaviour is not limited to hydrogenation catalysis and affects various catalytic transformations. In this feature article, we discuss these catalytically relevant descriptors in an attempt to arrive at a comprehensive depiction of catalytic performance. [ABSTRACT FROM AUTHOR]

Beams, plates, and shells, as the fundamental mechanical structures, are widely used in microelectromechanical systems (MEMS) and nanoelectromechanical systems (NEMS) as sensors, actuators, energy harvesters, and among others. Deeply understand the electromechanical coupling of these dielectric structures is of crucial for designing, fabricating, and optimizing practice devices in these systems. Herein we demonstrate the electromechanical coupling in flexoelectric circular plate, in which higher-order strain gradients were considered to extend the classical electromechanical properties to isotropic materials, in which the non-uniform distribution of the electric potential along the radial direction was considered. Analytical solutions for the vibration modes of the flexoelectric circular plates showed that the dynamic modes were totally different from the piezoelectric circular plates owing to the inversion symmetry breaking by the strain gradient. The electromechanical coupling dynamic modes are sensitive to bending, twisting modes owing to the sensitivity of the flexoelectric effect to bending. This work provides a fundamental understanding of the electromechanical coupling in flexoelectric circular plate, which is helpful in designing novel flexoelectric circular plate-based devices, such as flexoelectric mirrors. [ABSTRACT FROM AUTHOR]

In this study, the dynamics and stability of a flexible rotor containing liquid in a constant thermal environment are investigated. According to thermoelastic theory, the thermal axial force exerted on the rotor is calculated by using the analytical method. A spinning Rayleigh beam is used as a simplified model of the rotor. Applying the Hamilton principle, the governing equation of motion for the flexible liquid-filled rotor system is derived. Using the obtained model, the stability prediction model and the critical spinning speed for the rotor system are formulated. To demonstrate the validity of the developed model, the present analysis is compared with the results reported in the previous study, and good agreement is observed from the comparison results. Finally, numerical results based on the obtained model are performed for a better understanding of the parameters including filling parameters, mode number, rotatory inertia and thermal effect on the stability, and critical spinning speed of the rotor system. [ABSTRACT FROM AUTHOR]

Metal elements are present in the human body, and their levels in the blood have important impacts on health. In this study, 2488 Chinese individuals were included in a genome-wide association study of 21 serum metal levels, with approximately 179,000 East Asian individuals in a bidirectional two-sample Mendelian randomization (MR) analysis, and 628,000 Europeans in a two-sample MR analysis. We identified two single nucleotide polymorphisms (SNPs) rs35691438 and rs671 that were significantly associated with serum copper levels (SCLs). The bidirectional two-sample MR analysis in the East Asian population showed that gamma-glutamyl transpeptidase levels have a causal effect on SCLs. SCLs have causal effects on six outcomes, namely risks of esophageal varix, glaucoma, sleep apnea syndrome, and systemic lupus erythematosus, white blood cell count, and usage of drugs affecting bone structure and mineralization. The two-sample MR analyses in the European population showed causal effects of erythrocyte copper levels on risks of carpal tunnel syndrome and compression fracture. Our results provide original insights into the causal relationship between blood metal levels and multiple human phenotypes. A genome-wide association study in a Chinese population identifies SNPs associated with serum copper levels. Mendelian randomization analysis reveals causal effects on multiple human phenotypes in East Asian and European populations. [ABSTRACT FROM AUTHOR]

• The combined amendment decreased soil cd availability and guaranteed the clean production of rice in three consecutive seasons. • The supplementary application of LS further decreased soil cd availability and cd accumulation in rice. • Health risk of consumption of rice was significantly decreased after combined amendment application. The scientific application of stabilized materials has been considered an effective method for the in situ remediation of Cd-contaminated soil. This study aimed to investigate the persistence of the effect of a combined amendment of limestone and sepiolite (LS) on soil Cd availability and accumulation in rice grown in a mildly Cd-contaminated paddy field (0.45 mg/kg of Cd) over three consecutive rice seasons. 1125–4500 kg/ha of LS was applied to the soil before the first rice planting season and 562.5–2250 kg/ha of LS was supplemented before the third rice planting season. The application of LS (1125–4500 kg/ha) increased the soil pH by 0.44–1.09, 0.18–0.53, and 0.42–0.68 in the first, second, and third season, respectively, and decreased the soil acid-extractable Cd content by 18.2–36.4%, 17.7–33.5%, and 9.6–17.6%. LS application significantly decreased the Cd contents in the rice tissues. The application of 4500 kg/ha of LS decreased the Cd content in brown rice to below the National Food Limit Standard of 0.2 mg/kg (GB 2762-2017) in the three consecutive rice seasons. However, the effect of LS on the soil-rice system was significantly weakened in the third season. The supplementary application of 562.5–2250 kg/ha of LS further decreased the Cd content in brown rice by 26.1–56.5% and decreased the health risk index by 23.7–43.8%. Therefore, it was recommended to apply 4500 kg/ha of LS in the first season and to supplement 2250 kg/ha of LS in the third season to effectively guarantee the clean production of rice in three consecutive rice seasons. [Display omitted] [ABSTRACT FROM AUTHOR]

Homogeneous hydrogenation catalysts based on metal complexes provide a diverse and highly tunable tool for the fine chemical industry. To fully unleash their potential, fast and effective methods for the evaluation of catalytic properties are needed. In turn, this requires changes in the experimental approaches to test and evaluate the performance of the catalytic processes. Design of experiment combined with statistical analysis can enable time‐ and resource‐efficient experimentation. In this work, we employ a set of different statistical models to obtain the detailed kinetic description of a highly active homogeneous Mn (I) ketone hydrogenation catalyst as a representative model system. The reaction kinetics were analyzed using a full second order polynomial regression model, two models with eliminated parameters and finally a model which implements "chemical logic". The coefficients obtained are compared with the corresponding high‐quality kinetic parameters acquired using conventional kinetic experiments. We demonstrate that various kinetic effects can be well captured using different statistical models, providing important insights into the reaction kinetics and mechanism of a complex catalytic reaction. [ABSTRACT FROM AUTHOR]

• Velocity data series with no temporal averaging process are attainted. • High-performance circuit system contributes to accurate velocity measurements. • Temporal averaging process is realized by splicing pulses sampled at various times. • Turbulence intensities show an almost linear decrease with temporal averaging. • Data quality affects the reduce rate of turbulence intensity after averaging process. The temporal averaging process (TAP) in Acoustic Doppler Velocimeters (ADVs) and its impact on turbulence measurement have been extensively studied. However, few studies have successfully replicated TAP. This paper utilizes a self-developed ultrasonic velocimeter recording raw acoustic signals, achieving TAP through pulse signal concatenation. Results from open-channel flow velocity measurements demonstrate measurement accuracy. Exploring TAP's effects on turbulence measurement, three velocity sequences with varying data qualities are analyzed. Proportion of valid data increases after TAP, with similar growth rates across different sampling volumes. Turbulence intensity decreases linearly with TAP, correlating with data quality. Employing an enhanced denoising method, a comparison suggests potential gradual reduction in Doppler noise with TAP implementation. This study offers valuable insights into turbulence measurement in ADV. [ABSTRACT FROM AUTHOR]

Atomic force microscope (AFM) is widely applied to the measurement of the micro-nano structures due to its three-dimensional spatial resolution of sub-nanometer. However, the height measurement traceability in the z-axis is complex to be implemented in conventional AFMs. In this paper, a traceable AFM is developed based on the monochromatic light interference (MLI) principle without probe calibration. The height change of the AFM's probe is directly detected by extracting the phase change of the MLI fringes on the probe tip with the Hilbert transform based phase extraction algorithm, and the three-dimensional surface topography is reconstructed with a surface recovery algorithm. The configuration of tracing to the wavelength of the monochromatic light in real-time further improves the measurement accuracy of the MLI-AFM. A prototype MLI-AFM is established to demonstrate its measurement accuracy enhancement. • A traceable atomic force microscope (AFM) is developed without probe calibration. • The probe height is traced to the monochromatic wavelength in real-time. • A prototype AFM is established to demonstrate its measurement performance. [ABSTRACT FROM AUTHOR]

An umpolung 1,4‐addition of aryl iodides to enals promoted by cooperative (terpy)Pd/NHC catalysis was developed that generates various bioactive β,β‐diaryl propanoate derivatives. This system is not only the first reported palladium‐catalyzed arylation of NHC‐bound homoenolates but also expands the scope of NHC‐induced umpolung transformations. A diverse array of functional groups such as esters, nitriles, alcohols, and heterocycles are tolerated under the mild conditions. This method also circumvents the use of moisture‐sensitive organometallic reagents. [ABSTRACT FROM AUTHOR]

An umpolung 1,4‐addition of aryl iodides to enals promoted by cooperative (terpy)Pd/NHC catalysis was developed that generates various bioactive β,β‐diaryl propanoate derivatives. This system is not only the first reported palladium‐catalyzed arylation of NHC‐bound homoenolates but also expands the scope of NHC‐induced umpolung transformations. A diverse array of functional groups such as esters, nitriles, alcohols, and heterocycles are tolerated under the mild conditions. This method also circumvents the use of moisture‐sensitive organometallic reagents. [ABSTRACT FROM AUTHOR]

Abstract Commonly used diagonal pivoting strategies for general symmetric matrix would bring about triangular factorization PAP'=LDL', in which D is block diagonal matrix with either 1 × 1 or 2 × 2 diagonal blocks. This paper proposed a modified add–sub pivoting strategy resulting in D with no 2 × 2 diagonal block and a corresponding symmetric triangular factorization algorithm for solving symmetric linear system Ax=b. The factorization algorithm is based on symmetric Gaussian elimination; The pivoting strategy involves searching two suitable columns in the trailing submatrix A k by rook method, interchanging the first one of them with column k, and then adding the second one multiplied by a scalar γ to column k. This strategy is similar to an earlier one proposed by Dax; Its comparisons required are still O(n2) ∼ O(n3), but the bound on elements of L is lower, and especially the growth factor is bounded by 3. The results from numerical experiments with both ill-conditioned and good-conditioned symmetric indefinite linear systems show that the new algorithm is competitive with the B–K algorithm, the BBK algorithm, and the LU factorization with partial pivoting. [ABSTRACT FROM AUTHOR]

A DMAP-catalyzed [4 + 2] annulation of α-substituted allenoates with unsaturated pyrazolones has been achieved in dichloromethane at 40 °C, providing multisubstituted tetrahydropyrano [2,3-c]pyrazoles in good to excellent yields with moderate to good Z/E ratios. The allenoates worked as two-carbon synthons in the reaction. To create your abstract, type over the instructions in the template box below. Fonts or abstract dimensions should not be changed or altered. Image 1 [ABSTRACT FROM AUTHOR]

Abstract Accurate and efficient peak extraction algorithm is essential in real-time chromatic confocal measurement. However, current state-of-art algorithms cannot simultaneously satisfy the requirement of high extraction accuracy and computational efficiency. In this paper, we propose a corrected fitting differential algorithm (CFDA) with good-accuracy and high computational efficiency. Firstly, the CFDA is conducted to extract the initial peak wavelength with the conventional linear fitting of the differential signal, which is derived from the spectral axial intensity signal. Secondly, the fitting error is characterized via a generalized differential equation. Finally, the error is estimated and corrected by solving this equation with a first-order approximation. Compared to the high-accuracy Gaussian fitting algorithm, our simulations and experiments demonstrate that the CFDA can achieve approximately a hundred times improvement in computing efficiency while maintaining a comparable peak extraction accuracy. Highlights • An accurate and efficient peak extraction algorithm is proposed. • A differential equation based systematic error analysis method of generality is proposed. • An approximate solution of this differential equation is provided with generality. • Simulations demonstrated high computational efficiency and good peak extraction accuracy of the algorithm. • Experimental results indicated the potential of the method for the real-time measuring CCM. [ABSTRACT FROM AUTHOR]

Background: The association of ABO blood groups with gastric cancer risk was proposed decades ago, but the results have been inconsistent.Methods: We used two single nucleotide polymorphisms to determine ABO genotype in 4932 gastric cancer cases and 6158 controls of Chinese descent, and evaluated the associations of ABO blood groups and genotypes with risk of gastric cancer using multivariable logistic regression models. We also systematically reviewed published literature and performed a meta-analysis of all relevant studies.Results: In the case-control study, compared with blood group O, both blood group A and AB were associated with increased gastric cancer risk (for group A, odds ratio (OR) = 1.13, 95% confidence interval (CI): 1.02-1.24; for group AB, OR = 1.18, 95% CI: 1.02-1.36, respectively). Analyses of ABO genotypes revealed associations of AO and AB with risk of gastric cancer compared with OO genotype. Consistent with the case-control study, meta-analysis of 40 studies including 33,613 cases and 2,431,327 controls demonstrated that blood group A (OR = 1.19, 95% CI: 1.13-1.25) and AB (OR = 1.09, 95% CI: 1.03-1.16) were associated with increased risk of gastric cancer.Conclusions: Our analyses validated the association of blood group A with risk of gastric cancer, and suggested that blood group AB was also associated with gastric cancer risk. Functional investigations are warranted to elucidate the exact mechanism of ABO blood groups in gastric carcinogenesis. [ABSTRACT FROM AUTHOR]

Taken the flexible shaft and elastic disk rotor system as the research object, vibration differential equations are established by the modal synthesis method. Based on the Runge–Kutta method of direct integration, dynamic equations are solved successfully. Then, the effects of Alford force caused by the airflow excitation are researched on the stability and dynamic response. The results show modal vibration of the disk takes a great effect on the coupled natural frequency of shaft transverse vibration in the high rotational speed region. The effect of shaft-disk coupling makes rotor frequency to decrease, and different rotational speeds have little effect on rotor frequency. Eccentric distance is sensitive to the amplitude of rotor response, but it has little effect on rotor stability, motion law, and relative relationship of two response frequencies. The proportion of rotor responses caused by aerodynamic excitation force becomes larger with the increase of rotational speed and disk radius. However, the proportion decreases with the second support moving to the right, and it is helpful for the stable operation of the rotor system. [ABSTRACT FROM AUTHOR]

Background: Idiopathic pulmonary fibrosis (IPF) is a progressive disease with a five-year survival rate of less than 40%. There is significant variability in survival time among IPF patients, but the underlying mechanisms for this are not clear yet. Methods and results: We collected single-cell RNA sequence data of 13,223 epithelial cells taken from 32 IPF patients and bulk RNA sequence data from 456 IPF patients in GEO. Based on unsupervised clustering analysis at the single-cell level and deconvolution algorithm at bulk RNA sequence data, we discovered a special alveolar type 2 cell subtype characterized by high expression of CCL20 (referred to as ATII-CCL20), and found that IPF patients with a higher proportion of ATII-CCL20 had worse prognoses. Furthermore, we uncovered the upregulation of immune cell infiltration and metabolic functions in IPF patients with a higher proportion of ATII-CCL20. Finally, the comprehensive decision tree and nomogram were constructed to optimize the risk stratification of IPF patients and provide a reference for accurate prognosis evaluation. Conclusions: Our study by integrating single-cell and bulk RNA sequence data from IPF patients identified a special subtype of ATII cells, ATII-CCL20, which was found to be a risk cell subtype associated with poor prognosis in IPF patients. More importantly, the ATII-CCL20 cell subtype was linked with metabolic functions and immune infiltration. [ABSTRACT FROM AUTHOR]

Patterns of spatial and temporal variability of algal bloom in the Three Gorges Reservoir (TGR) of China were investigated using Semi-implicit Eulerian-Lagrangian Finite Element (SELFE) model, an unstructured grid, 3-dimensional, hydrodynamic model fully coupled with an extended version of Water Quality Analysis Program (WASP) and the Carbon and Nutrients DIagenesis (CANDI) model. The coupled model was driven by the discharge, operational water level of the TGR, nutrients and phytoplankton from the upstream, climate condition included the solar radiation, heat fluxes and precipitation observed in the hydrometric and meteorological stations. The simulations were conducted to study the dynamic process of the algal blooms occurred in September 2007 and June 2008, and the modeling results agreed well with the field data included nutrients, chlorophyll-a concentrations in the TGR. The results indicated that the nutrients and chlorophyll-a concentrations showed obvious difference in the mainstream and the tributaries affected by the diurnal evolution of the phytoplankton during the algal bloom period. The location of algal bloom in the tributary Xiangxi River where the maximum chlorophyll-a concentration was greater than 30 μg/L was about 20 km from the river mouth, which coincided with the position of backwater tail controlled by the operation of the TGR. Meanwhile, the nutrients concentration near the river bed reached nearly 10 times of the concentration near the water surface after considering the nutrients released from the re-suspended sediment and the biogeochemical process in the river bed sediment. Finally, the climate change affected the aquatic ecosystem in the TGR was investigated and the countermeasure to inhibit the algal bloom in the tributary was suggested through the scenario modeling. [ABSTRACT FROM AUTHOR]

Flexoelectricity becomes remarkable in nanoscale dielectrics where strong strain gradients are expected. The effect of flexoelectricity on elastic plane waves propagating in nanoscale layered phononic crystals is discussed in the current work. The fundamental governing equations and boundary conditions are derived from the virtual work principle. Detailed calculations are performed for nanoscale two-layered and three-layered phononic crystals using the transfer matrix method. Numerical results indicate that phononic crystals possess frequency pass bands and stop bands. For nanoscale layered phononic crystals, flexoelectricity increases the middle frequency regardless of the thickness ratio, whereas the flexoelectric effect on the bandwidth depends on the thickness ratio, which implies that there is an optimal thickness ratio to maximize the bandwidth. In addition, the middle frequency and bandwidth decrease with an increase in the unit cell thickness if the thickness ratio is fixed. Hence, considering the flexoelectric effect on band structures of nanoscale phononic crystals may provide guidance in manipulating elastic wave propagation and facilitate potential applications in phononic crystal devices. [ABSTRACT FROM AUTHOR]

The muscle regeneration is a complicated bioprocess that involved in many cell types, including necrotic muscle cells, satellite cells, mesenchymal cells, pericytes, immune cells, and other cell types present at the injury site. Immune cells involved in both innate and adaptive immune responses regulate the progress of muscle regeneration. In this review, we discussed the roles of different immune cells in muscle regeneration. The immune cells regulate muscle regeneration through cytokine production, cell-cell contacts, and general immune environment regulation. We also describe the current known mechanism of how immune cells regulating muscle regeneration. [ABSTRACT FROM AUTHOR]

Probe calibration is the basis of accurate atomic force microscope (AFM) measurement. In white light interference based AFM (WLI-AFM), the relationship between the vertical displacement of probe and the position of the interference fringes on probe cantilever should be calibrated for accurate measurement. In this paper, a traceable probe calibration method for WLI-AFM is proposed. A high resolution displacement measurement system based on laser interference is constructed to obtain the vertical displacement of probe with high accuracy. This system is used for standard displacement input for calibration and makes the measurement result traceable to optical wavelength. A zero-order fringe positioning algorithm is presented to determine the position of the interference fringes on probe cantilever. A probe deflection model is established for the calibration relationship which is continuous and can be used for measurement. While calibration is conducted, series of zero-order fringe positions are obtained corresponding to the probe displacement inputs. The data are processed by the probe deflection model to obtain the calibration relationship. The proposed method is applied in a self-developed WLI-AFM. It is verified that the accuracy of the method is higher than the previous methods by certain experiments on this WLI-AFM. [ABSTRACT FROM AUTHOR]

The dynamic characteristics of an atomic force probe are important for rapid and accurate measurement in white light interference (WLI) based atomic force microscope (AFM). The tip of the probe will fly from the surface when its dynamic characteristics are poor, which will cause measurement error. Generally such tip flight can be avoided by reducing the scanning speed, which will decrease the error at the cost of measurement efficiency. In this paper, a dynamical model of atomic force probe is presented to analyze the causes of tip flight in the measurement process. A numerical simulation is performed on a typical sample surface to investigate the influence of profile, preloading and probe parameters on scanning speed. Experimental testing is conducted on a self-developed WLI based AFM, and the experimental results agree well with that of the theory. The maximum scanning speeds of the probe for a sample are tested under certain conditions. It is shown that for a certain probe, the tip flight occurs at the upwards points of the measured sample when the scanning speed exceeds the critical speed, which is constrained by the preloading. [ABSTRACT FROM AUTHOR]

Background/Aims: The increasing prevalence of ionizing radiation exposure has inevitably raised public concern over the potential detrimental effects of ionizing radiation on male reproductive system function. The detection of drug candidates to prevent reproductive system from damage caused by ionizing radiation is urgent. We aimed to investigate the protective role of taurine on the injury of mouse spermatocyte-derived cells (GC-2) subjected to ionizing radiation. Methods: mouse spermatocytes (GC-2 cells) were exposed to ionizing radiation with or without treatment of Taurine. The effect of ionizing radiation and Taurine treatment on GC-2 cells were evaluated by cell viability assay (CCK8), cell cycle and apoptosis. The relative protein abundance change was determined by Western blotting. The siRNA was used to explore whether Nrf2 signaling was involved in the cytoprotection of Taurine. Results: Taurine significantly inhibited the decrease of cell viability, percentage of apoptotic cells and cell cycle arrest induced by ionizing radiation. Western blot analysis showed that taurine significantly limited the ionizing radiation-induced down-regulation of CyclinB1 and CDK1, and suppressed activation of Fas/FasL system pathway. In addition, taurine treatment significantly increased the expression of Nrf2 and HO-1 in GC-2 cells exposed to ionizing radiation, two components in antioxidant pathway. The above cytoprotection of Taurine was blocked by siNrf2. Conclusion: Our results demonstrate that taurine has the potential to effectively protect GC-2 cells from ionizing radiation-triggered damage via upregulation of Nrf2/HO-1 signaling. [ABSTRACT FROM AUTHOR]

In this paper, the flexoelectric effect on Love waves propagating in a structure with a nanoscale piezoelectric guiding layer deposited on an isotropic elastic substrate is analytically investigated. Transcendental complex dispersion equations are obtained and solved numerically which are corresponding to the electrically open and short conditions at the free surface. A detailed discussion about the dispersion relations of the fundamental mode is subsequently presented. The results indicate that flexoelectricity has a substantial effect on Love wave propagation. The presence of flexoelectricity leads to a complex phase velocity with a negative/positive imaginary part, which means Love waves attenuate/grow over time. In addition, the phase velocity dispersion relations depend greatly on the thickness and flexoelectric coefficients of the guiding layer. The current work is the first attempt to explore the flexoelectric effect on the propagation characteristics of surface acoustic waves (SAWs). And the results would be beneficial to achieve a better performance of SAW devices. [ABSTRACT FROM PUBLISHER]

In this paper, phosphine-catalyzed [3 + 3] annulation of Morita-Baylis-Hillman carbonates with C, N-cyclic azomethine imines has been achieved. The reaction worked smoothly under mild conditions to afford 4,6,7,11b-tetrahydro-1 H-pyridazino[6,1- a]isoquinoline derivatives in high yields with good to excellent diastereoselectivities. [ABSTRACT FROM AUTHOR]

We compared a quasi-static ultrasound elastography technique, referred to as electrode displacement elastography (EDE), with acoustic radiation force impulse imaging (ARFI) for monitoring microwave ablation (MWA) procedures on patients diagnosed with liver neoplasms. Forty-nine patients recruited to this study underwent EDE and ARFI with a Siemens Acuson S2000 system after an MWA procedure. On the basis of visualization results from two observers, the ablated region in ARFI images was recognizable on 20 patients on average in conjunction with B-mode imaging, whereas delineable ablation boundaries could be generated on 4 patients on average. With EDE, the ablated region was delineable on 40 patients on average, with less imaging depth dependence. Study of tissue-mimicking phantoms revealed that the ablation region dimensions measured on EDE and ARFI images were within 8%, whereas the image contrast and contrast-to-noise ratio with EDE was two to three times higher than that obtained with ARFI. This study indicated that EDE provided improved monitoring results for minimally invasive MWA in clinical procedures for liver cancer and metastases. [ABSTRACT FROM AUTHOR]

Aims: This study is aimed to investigate the efficiency of plant growth-promoting (PGP) strategies of Enterobacter sp. strain EG16 under metal stress and its potential application in phytoremediation. Methods: Production of siderophores and indole-3-acetic acid (IAA) by EG16 were assessed in a hydroponic system in which Hibiscus cannabinus was grown with different concentrations of Cd and Fe. A pot experiment was also carried out to evaluate the practical effect of EG16 on H. cannabinus growth and remediation efficiency. Results: Inoculation with EG16 significantly improved plant growth, probably as a result of increased plant uptake of Fe and immobilization of Cd, which resulted in decreased plant accumulation of Cd. Increased production of siderophores by EG16 in response to Cd exposure appeared to be the PGP strategy functioning in the EG16- H. cannabinus association. The bacterial Cd response system promoted plant and bacterial uptake of Fe, alleviated Cd-induced inhibition of bacterial IAA production, and potentially assisted in metal immobilization in the rhizosphere. Conclusions: The EG16- H. cannabinus association may be useful for phytostabilization, as it exhibits good plant growth, low plant accumulation of metals, and reduced metal bioavailability in soil. [ABSTRACT FROM AUTHOR]

The Chinese Fusion Engineering Test Reactor (CFETR) is under design. It aims to fill the gaps between ITER and DEMO. In the reactor, the deuterium-tritium fusion reaction and the auxiliary heating will generate a lot of energetic particles. It is possible that these energetic particles will drive toroidal Alfvén eigenmode (TAE) instabilities under the conditions of CFETR plasma parameters. These instabilities can result in energetic particles redistribution or loss, so it’s vital to study TAE instabilities in CFETR. The aim of this paper is to study the possibility of reducing TAE instabilities by changing safety factor profiles in CFETR. NOVA and NOVA-K codes are used to study TAE stability. The equilibria are constructed using the CORSICA code. Safety factor profiles are selected as the three typical profiles of ITER scenarios. For the three different safety factor profiles, we use NOVA to scan and calculate their continuum spectrum and eigenmode structures, then use NOVA-K to calculate the different damping and driving mechanisms for different toroidal mode numbers. The numerical calculations show that if the safety factor profiles are chosen appropriately, then all the TAEs can be stable. Thus, it’s possible to reduce the TAE instabilities by changing safety factor profiles in CFETR. We also scan the temperature and density profiles to see their effects on the TAE instabilities. It shows that the TAE instabilities keep unchanged for a wide range of profiles. [ABSTRACT FROM AUTHOR]

• A set of data processing methods for measuring suspended sediment concentration based on self-developed ultrasonic measuring instrument. • Deriving a formula of sediment concentration measurement based on multi-frequency ultrasound. • Verifying the correlation to 1/2 powers between the intensity of the ultrasonic echo signal and the concentration of the suspended sediment. • Quantitatively analyzing the conversion errors of ultrasonic echo intensity and concentration in mixed particle size liquid. Suspended sediment concentration is one of the basic data requirements in hydraulic engineering, environment, ocean, and other related fields. Based on the response relationship of ultrasonic waves to sediment particles, this study investigated the multi-frequency ultrasonic measurement and derived the theory formula. In the formula, the relationship between concentration and intensity existed only in theory, and there was no experimental data to verify it. The multi-frequency ultrasonic measurement experiment of suspended sediment was carried out by a self-developed ultrasonic measuring instrument, which verified the corresponding relation between concentration and scattering intensity is proportional to the power of half. In a single group of experiments, it was verified the concentration conversion can be carried out as the concentration bases are 0.1 and 0.3 kg/m3. In the multi-frequency concentration conversion of mixed particle size, and the error between theory and measurement was 6 %, proving that it has feasibility for sediment concentration measurement. [ABSTRACT FROM AUTHOR]

The oxidation of neat NH 3 and co-oxidation of NH 3 with H 2 /CO/CH 4 are investigated both experimentally and numerically. Experiments were carried out in a fused silica jet-stirred reactor with a fixed residence time of 1.5 s. Oxidation products of NH 3 /O 2 /Ar, NH 3 /H 2 /O 2 /Ar, NH 3 /CO/O 2 /Ar, and NH 3 /CH 4 /O 2 /Ar mixtures were measured at various temperatures from 950 K to 1400 K, and equivalence ratios of 0.5∼2.0. A detailed kinetic model was developed and validated by the present experimental data and literature data. The experimental results indicate that NH 3 reactivity is promoted by H 2 addition below 950 K and by CO/CH 4 addition below 1175 K. Kinetic analysis shows that HO 2 radical is an important intermediate to trigger the oxidation of NH 3. HO 2 radicals can be converted into OH radicals through the catalytic cycle reactions of NO+HO 2 NO 2 +OH and NO 2 +H NO+OH, realizing the consumption of NH 3. Then NH 2 is oxidized by HO 2 radicals and NO 2 through the pathway of NH 2 →H 2 NO→HNO→NO→NO 2 for producing more active radicals. H 2 can provide a large amount of HO 2 and H radicals, and CO relies on the interaction of NH 2 and CO (NH 2 +CO HNCO+H) to provide H radicals for achieving the catalytic cycle, while CH 4 faces the competition between CH 3 and H radicals for NO 2 (CH 3 +NO 2 CH 3 O+NO and NO 2 +H NO+OH), resulting in the ability of H 2 to lower the NH 3 reactivity onset much stronger than that of CO and CH 4. With the increase in temperature, the HO 2 radicals tend to inhibit the oxidation of NH 3 by the chain-termination reaction of NH 2 +HO 2 NH 3 +O 2. The oxidation of NH 3 is gradually dominated by the independent interaction of fuels and H/OH/O radicals. H/OH/O radicals promote the conversion of NH i (i = 0, 1, 2) to NO. As a result of the stronger ability to carry H atoms, the most active NO chemistry is found in the co-oxidation of NH 3 /CH 4 , while the least active NO chemistry is discovered in the oxidation of neat NH 3 for the strong reduction effect of NH i. In stoichiometric conditions, the formation of NO mainly depends on NH radicals, and the formation and reduction of NO by N and NH 2 radicals are almost equivalent. In lean conditions, as the importance of NH radicals decrease, the production of NO is mainly dependent on the conversion of NH 2 to NO through HNO intermediate. [ABSTRACT FROM AUTHOR]

Microwave ablation has been used clinically as an alternative to surgical resection. However, lack of real-time imaging to assess treated regions may compromise treatment outcomes. We previously introduced electrode displacement elastography (EDE) for strain imaging and verified its feasibility in vivo on porcine animal models. In this study, we evaluated EDE on 44 patients diagnosed with hepatocellular carcinoma, treated using microwave ablation. The ablated region was identified on EDE images for 40 of the 44 patients. Ablation areas averaged 13.38 ± 4.99 cm 2 on EDE, compared with 7.61 ± 3.21 cm 2 on B-mode imaging. Contrast and contrast-to-noise ratios obtained with EDE were 232% and 98%, respectively, significantly higher than values measured on B-mode images ( p < 0.001). This study indicates that EDE is feasible in patients and provides improved visualization of the ablation zone compared with B-mode ultrasound. [ABSTRACT FROM AUTHOR]

• Distribution characteristics are useful in de-spiking velocity data. • The proposed filtering method preserves valid data to the greatest extend. • Power spectra calculated from altered fluctuating velocity signals changes subtly. • Consideration should be taken in choosing the suitable spike-replacement strategy. Acoustic doppler velocimeter (ADV) has attracted significant attention, especially the research on its data post-processing, which is a vitial step before calculating turbulence statistics. This work processes the acoustic correlation velocimeter (ACV) time series, which have an identical characteristics with ADV data, sampled in open-channel flows utilizing current algorithms combined with a proposed modified kernel density-based algorithm (mkde) that preserves valid data to a larger extent. Trials investigating several interpolation strategies among various velocity series with different data quality demonstrate that without any replacement, the power spectrum density of data series with up to 22% spikes satisfies the Kolmogorov −5/3 law in an inertial subrange. Moreover, in highly contaminated velocity series presenting more consecutive spikes, linear and the last valid data interpolation turned out to be more robust. This paper shed light on dealing with outliers in acoustic Doppler velocimeter data. [ABSTRACT FROM AUTHOR]

For vibration analysis of aeroengine blisk structure, a prestressed component modal synthesis (CMS) super-element method is put forward with the fixed interface prestressing and free interface super-element approach. Based on this method, natural vibration characteristics of blisk structure are calculated at different modal truncation numbers. Comparing with the accurate result of global method, the selection principle of modal truncation number is obtained which affects the accuracy of prestressed CMS super-element method. Vibration response of two-stage blisk structure is calculated by this method, and the effects of different blade aspect ratios have been discussed on vibration characteristics. The results show that prestressed CMS super-element method is in the high accuracy and efficiency on blisk vibration analysis. Resonant frequencies in vibration response are nearly the same between the first-stage blisk and the second-stage blisk, and they are both approximately located in the range 588 Hz–599 Hz. The maximum displacement and dynamic stress are at blade tip and root of the first-stage blisk, respectively. Blade aspect ratio is a key factor of blisk vibration; the effects of blade aspect ratio on natural frequencies are different in the conditions of fixed width and fixed length. This research provides the theoretical basis for dynamic design of aeroengine compressor rotor system. [ABSTRACT FROM AUTHOR]

A multifunctional chiral phosphine-catalyzed enantioselective [3+2] annulation of Morita-Baylis-Hillman carbonates with barbiturate-derived alkenes has been achieved under mild conditions, providing a variety of chiral spirobarbiturate-cyclopentenes in moderate to excellent yields with moderate to excellent diastereo- and enantioselectivities. [ABSTRACT FROM AUTHOR]

Purpose: Ultrasound strain imaging is a relatively low cost and portable modality for monitoring percutaneous thermal ablation of liver neoplasms. However, a 3D strain volume reconstruction from existing 2D strain images is necessary to fully delineate the thermal dose distribution. Tissue mimicking (TM) phantom experiments were performed to validate a novel volume reconstruction algorithm referred to as sheaf of ultrasound planes reconstruction (SOUPR), based on a series of 2D rotational imaging planes. Methods: Reconstruction using SOUPR was formulated as an optimization problem with constraints on data consistency with 2D strain images and data smoothness of the volume data. Reconstructed ablation inclusion dimensions, volume, and elastographic signal to noise ratio (SNRe) and contrast to noise ratio (CNRe) were compared with conventional 3D ultrasound strain imaging based on interpolating a series of quasiparallel 2D strain images with a wobbler transducer. Results: Volume estimates of the phantom inclusion were in a similar range for both acquisition approaches. SNRe and CNRe obtained with SOUPR were significantly higher on the order of 250% and 166%, respectively. The mean error of the inclusion dimension reconstructed with a wobbler transducer was on the order of 10.4%, 3.5%, and 19.0% along the X, Y, and Z axes, respectively, while the error with SOUPR was on the order of 2.6%, 2.8%, and 9.6%. A qualitative comparison of SOUPR and wobbler reconstruction was also performed using a thermally ablated region created in ex vivo bovine liver tissue. Conclusions: The authors have demonstrated using experimental evaluations with a TM phantom that the reconstruction results obtained with SOUPR were superior when compared with a conventional wobbler transducer in terms of inclusion shape preservation and detectability. [ABSTRACT FROM AUTHOR]

Constructed reed wetland microcosms (CRWs) in a lab of east China have been irrigated with bleaching wastewater per month for a reed growth season. The soil physicochemical properties, enzyme activities (i.e. urease, invertase, polyphenol oxidase, alkaline phosphatase and cellulase) and soil microbial diversity were assayed before and after the exposure experiment. Compared to the river water irrigated controls (CKs), bleaching wastewater application has no marked influence on soil pH, but significantly increased soil Na+, total halogen and absorbable organic halogen (AOX) contents, which induced the increasing of soil electrical conductivity. Furthermore, soil enzyme activities displayed significant variation (except for polyphenol oxidase). Bleaching wastewater irrigation decreased Sorenson's pairwise similarity coefficient (Cs), which indicated the changes of the structure of bacterial and fungal communities. However, only the diversity of bacterial community was inhibited and has no effect on the diversity of fungal community, as evidenced by the calculated Shannon-Wiener index (H). [ABSTRACT FROM AUTHOR]

This study explores the factors that affect healthcare personnel' safety culture in "Chinese Tertiary Traditional Chinese Medicine (TCM)" facilities to enhance the safety of patients and health care. The Chinese version of the "Safety Attitudes Questionnaire (CSAQ)", a survey tool was used to assess physicians' and nurses' patient safety attitudes was used to investigate this issue. This study employed the CSAQ, and 1377 questionnaires were distributed to three tertiary traditional Chinese Medicine hospitals. Respondents were medical personnel who submitted the survey through WeChat application. 461 surveys were deemed valid for analysis, resulting in a 33.48% response rate. Demographic characteristics were used as control variables in a "one-way ANOVA". The data structure was validated by utilizing confirmatory factor analysis (CFA). Subsequently, a linear regression analysis employing forward selection methodology was utilized to ascertain the predominant safety culture dimensions, also known as safety climate, that exerted the greatest influence. According to the CFA, 26 items in the CSAQ were assessed using six criteria about safety. The linear regression study showed that "working environment, teamwork climate, and job satisfaction" affect safety culture, particularly safety climate. [ABSTRACT FROM AUTHOR]

Flexoelectricity, representing the coupling between electrical polarizations and strain gradients, should be taken into account in the analysis of electromechanical responses of nanostructures where large strain gradients are expected. In this paper, we will explore the influence of flexoelectricity on the electromechanical coupling behavior of a simply supported piezoelectric nanoplate by using the Kirchhoff plate theory. The governing equations and corresponding boundary conditions are deduced from Hamilton's principle, and the analytical solutions are obtained for the deflection and natural frequency. The results indicate that the deflections predicted by the present model are smaller than those calculated by the classical one which only considers piezoelectricity, while the frequencies exhibit the opposite trend. In addition, the flexoelectric effect is more prominent for thinner plates; the differences of the deflections or frequencies between the two models are gradually diminishing with an increase in the plate thickness. The current work may contribute to the understanding of the higher-order electromechanical coupling mechanism. Moreover, the modified plate model can be utilized to accurately design novel piezoelectric nanoplate-based sensors in nanoelectromechanical systems. [ABSTRACT FROM AUTHOR]

Interleukin-1 beta (IL-1β) is a potent pro-inflammatory and pro-fibrotic cytokine that plays an important role in renal fibrosis. Fluorofenidone (AKF-PD) is a novel pyridone agent that exerts a strong renal anti-fibrotic effect. We previously found that administration of AKF-PD could significantly attenuate IL-1β production in vitro and in vivo. However, the underlying mechanism is not fully understood. Here we show that AKF-PD has no effect on the expression of pro-IL-1β in activated mouse macrophages in vitro. Instead, AKF-PD inhibits the inflammasome, lowering caspase-1 levels and thereby decreasing cleavage of pro-IL-1β into IL-1β. AKF-PD was found to block inflammasome activity induced by various signals, including ATP, alum crystals, and Salmonella typhimurium . These results provide a novel mechanistic insight into how AKF-PD exerts its anti-inflammatory and anti-fibrotic activities, and suggest that AKF-PD might block IL-1β production via suppression of inflammasomes in renal fibrosis. In addition, the results suggest that AKF-PD may be of therapeutic potential in other inflammasome-related diseases. [ABSTRACT FROM AUTHOR]

Background: Human nasopharyngeal carcinoma (NPC) is a malignant type of cancer with an increasing incidence. As yet, however, molecular biomarkers with a strong diagnostic impact and a major therapeutic promise have remained elusive. Here, we identified the esophageal carcinoma related gene 4 ( ECRG4) as a novel candidate tumor suppressor gene and a promising therapeutic target for NPC. Methods: RT-PCR, Western blotting, methylation-specific PCR and bisulfite sequencing were performed to assess the expression and methylation status of the ECRG4 gene in primary NPC samples, NPC-derived cell lines and patient-derived peripheral blood samples. The NPC-derived cell line CNE1 was selected for treatment with a methylation inhibitor to restore ECRG4 expression. In addition, cell proliferation, invasion and colony formation assays were performed to assess the inhibitory effects of exogenous ECRG4 expression in CNE1 cells. Results: Down-regulated ECRG4 expression was found to occur in 82.5 % (33/40) of the primary NPC biopsies tested. This down-regulation was significantly correlated with its tumor-specific promoter methylation status (72.5 %, 29/40) and was also observed in the matching peripheral blood samples from the NPC patients (57.5 %, 23/40). Pharmacologic demethylation through 5-aza-dC treatment led to gene reactivation in ECRG4 methylated and silenced NPC cell lines. Moreover, exogenous expression of ECRG4 in the CNE1 cell line strongly inhibited its growth and invasive capacities, as well as its enhanced chemosensitivity to cisplatin through autophagy induction. Conclusion: Our data suggest that methylation-mediated suppression of the ECRG4 gene occurs frequently in NPC and that restoration of its expression may have therapeutic benefits. [ABSTRACT FROM AUTHOR]

• Simulated component of cylinder head is established based on the equivalent model of flame deck. • The simulation method of thermo-mechanical fatigue is developed by the Sehitoglu theory and loading spectrums. • Damage characteristics at typical working condition are predicted from three damage types. As the vulnerable component of diesel engine, cylinder head is subjected to the thermo-mechanical coupling loads more and more heavily. For establishing a simple and effective technology to evaluate the damage degree, a prediction method based on simulated component is developed in the present work. By the comparison of temperature and stress at measured points, it shows that the simulation and testing results have a good agreement, verifying the effectiveness of simulated component. Applying Sehitoglu theory and loading spectrums, the failure locations are predicted successfully. Then damage characteristics of thermo-mechanical fatigue are analyzed at failure locations. It indicates that mechanical damage takes a leading role compared with oxidative damage and creep damage, and thermal load is more sensitive to mechanical damage in three damage types. This study may provide an effective way to estimate the service life of cylinder head. [ABSTRACT FROM AUTHOR]

microRNAs constitute a novel class of small, non-coding RNAs that negatively regulate gene expression via translational inhibition or mRNA degradation. Aberrant miRNA expression has been implicated in the initiation, progression, and metastasis of hepatocellular carcinoma (HCC). It is well-documented that miRNAs function as either tumor suppressor genes or oncogenes in the development and progression of HCC. Additionally, substantial evidence suggests that unique miRNA signatures can serve as valuable diagnostic and prognostic biomarkers for HCC. Interestingly, certain subsets of miRNAs have also been identified as potential therapeutic targets for HCC. [ABSTRACT FROM AUTHOR]

Redox condition and pH are the two most important factors affecting the arsenic (As) form. With changes of arsenic forms, desorption and migration of the soil As are likely to occur. In arid regions, the irrigation can result in the low soil gas permeability. It coupled with large amount of organic matter deposited in sediments can facilitate the formation of the reduction environment, in which iron and manganese oxides are easy to dissolve, and As can be converted into the dissolved forms that move with groundwater. The Qaidam Basin is located in the Qinghai-Tibet Plateau with the highest elevation in China. In the basin, there is little rain, the soil pH is 8, and it belongs to a typical arid region with sparse vegetation and high soil pH. The irrigation makes the agricultural cultivation possible here, but also changes the soil redox conditions, creating a good condition for soil As desorption and migration. It is necessary to clarify the influence of irrigation agriculture on soil As distribution and migration. This study aimed to investigate the soil As distribution and its influential factors. A 13.2 hm2 unreclaimed field was selected from the basin for the study. It was reclaimed for wolfberry cultivation. In the field, soil samples (0-20 cm) were collected from 22 points for soil As content detection before the cultivation, and in 1, 2, and 3 years of cultivation. Meanwhile, the factors related with agricultural activities were investigated and the soil As content in these factors were determined. The results showed that the soil As content was 0-26.4 mg/kg with the coefficient of variation (CV) of 0.47 before the cultivation, and about 45.5% of soil samples had soil As content exceeding the Green Food production standard of China (20 mg/kg). After 1-3 years of cultivation, the soil As content was clustered about an average of 15.50-15.88 mg/kg, and the numbers of soil samples points exceeding the standard decreased greatly. The Geographic Information Systems (GIS) spatial distribution map of soil As content revealed that the soil As content before the cultivation was high in the northwest and low in the southeast in the plot, an obvious decreasing trend from the northwest to the southeast. With the increase of farming years, the trend was still maintained but not obvious any more. It indicated that the soil arsenic content at depth of 20 cm was in a dynamic equilibrium with the increase of farming years. By calculating the soil As input from pesticides, fertilizers, and irrigation water and output from wolfberry fruits and stalk, the study showed that the soil As net input per year was 250 g/hm2. However, the measured soil As did not increased after 3 years of cultivation. Therefore, soil As may have the other output ways other than fruits collection and stalk. Downward migration of soil As was likely an output way, which was needed for validation in future. [ABSTRACT FROM AUTHOR]

Abstract: The kinetics of Se(IV) removal by zero valent iron (ZVI) open to the air as a function of pH and the involved mechanisms were investigated in this study. The specific rate constants of Se(IV) removal by ZVI decreased from 92.87 to 6.87 L h−1 m−2 as pH increased from 4.0 to 7.0. The positive correlation between the removal rate of Se(IV) and the generation rate of Fe(II) and the depression of Se(IV) removal in the presence of 1,10-phenanthroline indicated that both ZVI and adsorbed Fe(II) on ZVI surface contributed to the reductive removal of Se(IV). The soft X-ray STXM measurement confirmed the adsorption of Fe(II) on the surface of ZVI and freshly formed ferric (hydr)oxides. Se(IV) was removed by adsorption followed by reduction to Se(0) on ZVI surface at pH 4.0–7.0, as revealed by XANES spectra. A core-shell structure was observed when ZVI reacted with Se(IV)-containing solution for 3 h at pH 6.0. Se(IV) was reduced to Se(0) and co-precipitated with the freshly formed Fe(III), forming the shell surrounding the iron core. After reaction for 24 h, the generated Se(0) was surrounded by multiple layers of Fe(III) oxides/hydroxides. SEM images and XRD patterns revealed that the corrosion products of ZVI at pH 6.0 transformed from amorphous iron hydroxides to lepidocrocite (γ-FeOOH) as reaction proceeded. The final corrosion products of ZVI contained both lepidocrocite and goethite at pH 5.0 while they were X-ray amorphous at pH 4.0 and 7.0. [Copyright &y& Elsevier]

Background: Previous studies have shown a down-regulation of the gene encoding cyclin-dependent kinase 10 (CDK10) in hepatocellular carcinomas. Here we provide evidence that down-regulation of the CDK10 gene is mediated by promoter hypermethylation in primary human nasopharyngeal carcinomas (NPC) and NPC-derived cell lines. Methods: RT-PCR, Western blotting, methylation-specific PCR and bisulfite sequencing were performed to assess the expression and methylation status of the CDK10 gene in primary NPC samples, NPC-derived cell lines and patient-derived peripheral blood samples. The NPC-derived cell line CNE-2 was selected for treatment with a methylation inhibitor to restore CDK10 expression. In addition, cell proliferation, invasion and colony formation assays were performed to assess the inhibitory effects of ectopic CDK10 expression in CNE-2 cells. Results: Down-regulation of CDK10 expression in primary NPC samples (23/40, 57.5 %) was found to be significantly correlated with the methylation status of its promoter CpG island (21/40, 52.5 %). Demethylation by 5-aza-dC treatment led to reactivation of the CDK10 gene in the CNE-2 cell line. Additionally, exogenous expression of CDK10 in CNE-2 cells strongly suppressed its growth, invasion and colony formation capacities. The high sensitivity (15/40, 37.5 %) and specificity (0 % false positives) of detecting CDK10 promoter hypermethylation in NPC patient-derived peripheral blood samples suggest that it could be employed as an epigenetic marker for noninvasive cancer diagnosis and recurrence screening. Conclusion: Our findings implicate that aberrant methylation of the CDK10 gene promoter occurs frequently in NPC, and that reactivation of CDK10 might be utilized as a novel epigenetic strategy for the treatment of NPC patients. [ABSTRACT FROM AUTHOR]

Smooth pursuit is a physiological phenomenon of human eyes, which can be used as eye-control interaction to avoid the "Midas" problem. This article describes the smooth pursuit properties of continuous variable tasks under Euclid's algorithm. Two experiments were conducted to investigate the effects of slider speed, initial position of "plus," and variable value position on smooth pursuit interactions. The initial position and slider speed are combined in 12 combination forms, and the variable value positions are divided into 7 cases. Then, the optimal combination forms and variable value position case are derived. Experiment 1 divided the initial position into four levels of up, down, left and right and divided the slider speed into three levels of 1 deg/s, 2 deg/s, and 3 deg/s, concluding that the optimal combination of initial position and slider speed is that the speed is 2 deg/s and initial position is up. Experiment 2 was conducted on the basis of the conclusion obtained in experiment 1. The position of the variable value was divided into seven cases according to whether the left, center, and right of the smooth pursuit track the variable value appeared. The result showed that the position of the variable value in the center had the greatest influence on the pursuit efficiency. This research has an important value for the parameter set of smooth pursuit in the case of the Euclidean algorithm, it has great guiding significance for building smooth pursuit interaction in the context of the eye-control system. [ABSTRACT FROM AUTHOR]

Abstract: Star-burst dendrimers represent a superior carrier platform for targeted drug delivery. Partially acetylated generation 5 (G5) polyamidoamine (PAMAM) dendrimer was conjugated with the targeting moiety (biotin) and the imaging moiety (fluoresceinisothiocyanate, FITC), and the resulting dendrimer–biotin conjugate was characterized by 1H NMR, UV–vis spectrum. As revealed by flow cytometry and confocal microscopy, the bifunctional conjugate (dendrimer–biotin–FITC) exhibited much higher cellular uptake into HeLa cells than the conjugate without biotin. The uptake was energy-dependent, dose-dependent, and could be effectively blocked by dendrimer-conjugated biotin. Our results indicated that the biocompatible biotin–dendrimer conjugate might be a promising nano-platform for cancer therapy and cancer diagnosis. [Copyright &y& Elsevier]