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We consider the quasinormal modes, quasibound states and superradiant instability of a rotating hairy black hole, which possesses a Horndeski hair as deviation from Kerr black hole, under the perturbation of massive scalar field. With the use of the matrix method, we mainly calculate the eigenfrequencies related to those modes of the perturbation. Under the perturbation of the massless scalar field, the Horndeski hair and spin parameter have significant influences on the quasinormal frequency, but its imaginary part is always finite negative and no unstable mode is found. Under the perturbation of the massive scalar field, we focus on the eigenfrequencies of quasibound states and find the modes of which the imaginary part of eigenfrequencies is positive, indicating that the black hole undergoes superradiant instability. Then we scan the parameters and figure out a diagram in the space of Horndeski hair and spin parameters to distinguish the rotating hairy black hole with superradiant instability from the stable one. [ABSTRACT FROM AUTHOR]

In this paper, we study the propagations of external fields in a specific black hole solution in Horndeski theory, including the scalar field, electromagnetic field and Dirac field. We extensively explore the quasinormal frequencies, time evolution, greybody factors and emission rates of those massless perturbing fields by solving the corresponding master equations in the specific Horndeski hairy black hole. With the use of both numerical and analytical methods, we disclose the competitive/promotional influences of the Horndeski hair, spin and quantum momentum number of the external fields on those phenomenal physics. Our results show that this specific Horndeski hairy black hole is stable under those perturbations. Moreover, a larger Horndeski hair could enhance the intensity of energy emission rate for Hawking radiation of various particles, indicating that comparing to the Schwarzschild black hole, this specific Horndeski hariy black hole could have longer or shorter lifetime depending on the sign of the Horndeski hair. [ABSTRACT FROM AUTHOR]

Background: To investigate the efficacy and safety of lymph nodes (LNs) dissection guided by carbon nanoparticles (CNs) in gastric cancer (GC) surgery. Materials and methods: We searched electronic databases such as PubMed, Web of Science, Embase, Cochrane Library, and Scopus for relevant articles up to September 2022 and collected all studies comparing the CNs group with blank controls group on the efficacy and safety of LN dissection in gastrectomy. A pooled analysis of the collected data was performed, including the number of retrieved LNs, the staining rate of LNs, the number of metastatic LNs dissection, various intraoperative outcomes, and postoperative complications. Results: A total of 9 studies including 1770 participants (502 in the CNs group and 1268 in the control group) were included. As compared to the blank control group, the CNs group detected 10.46 more LNs in each patient (WMD = 10.46, 95% CI: 6.63 ~ 14.28, p < 0.00001, I2 = 91%), and also significantly more metastatic LNs (WMD = 2.63, 95% CI: 1.43 ~ 3.83, p < 0.0001, I2 = 41%). However, there was no significant difference in the rate of metastatic LNs between the CNs and control groups (OR = 1.37, 95% CI: 0.94 ~ 2.00, P = 0.1, I2 = 89%). In addition, there was no increase in operative time, intraoperative blood loss, and postoperative complications associated with CNs-guided gastrectomy. Conclusion: CNs-guided gastrectomy is safe and effective, and can increase the efficiency of LN dissection without increasing the risk of surgery. [ABSTRACT FROM AUTHOR]

The long-term administration of acyclovir (ACV) for therapy against herpes simplex virus type 1 (HSV-1) infections can result in the emergence of ACV-resistant HSV strains. It is therefore urgent to develop new anti-herpetic compounds with mechanisms that differ from that of ACV. Cyanovirin-N (CV-N) is an antiviral agent that has an inhibitory effect on HSV-1 infections, and PEGylation of CV-N is potentially useful for pharmaceutical applications. Here, a (Gly4Ser)3 linker molecule was attached to the N-terminus of CV-N, and the resulting compound, linker-CV-N (LCV-N), was produced on a pilot scale with purity up to 95%. Then, PEG10k-LCV-N was synthesized by modifying at the α-amine group of the N-terminus of LCV-N with 10-kDa polyethylene glycol propionaldehyde (mPEG-ALD). CV-N, LCV-N and PEG10k-LCV-N were all found to have potent inhibitory activity against ACV-resistant HSV strains with IC50 values in the nM range. LCV-N was the most potent of these three compounds against both normal and ACV-resistant HSV strains. Although PEG10k-LCV-N showed less antiviral activity than CV-N and LCV-N, it still exhibited significant and universal virucidal activity against drug-resistant viruses. The toxicity and immunogenicity of PEG10k-LCV-N were dramatically lower than those of CV-N and LCV-N. In conclusion, we suggest that LCV-N and PEG10k-LCV-N are promising and safe microbicides for the control and/or treatment of ACV-resistant HSV infection. [ABSTRACT FROM AUTHOR]

A novel electrochemical method for the sequence-specific detection of double-stranded polymerase chain reaction (PCR) products of PML/RARα fusion gene in acute promyelocytic leukemia (APL) was described in detail. Based on a 'sandwich' sensing mode involving a pair of locked nucleic acids probes (capture probe and reporter probe), this DNA sensor exhibited excellent selectivity and specificity. The direct and quantitative analysis of double-stranded complementary was firstly performed by our sensor without the use of alkali, helicase enzymes, or denaturants. Finally, combining PCR technique with electrochemical detection scheme, PCR amplicons (191 bp) of the PML/RARα fusion gene were obtained and rapidly identified with a low detection limit of 79 fmol in the 100-μL hybridization system. The results clearly showed the power of sensor as a promising tool for the sensitive, specific, and portable detection of APL and other diseases. [ABSTRACT FROM AUTHOR]

Turbidities and isobaric heat capacities per unit volume, in a wide temperature range, have been measured for critical binary solutions of {nitrobenzene + n-undecane} and {nitrobenzene + n-dodecane}. The critical exponents and the system-dependent critical amplitudes were deduced. The non-critical and the critical-fluctuation induced contributions to the background heat capacities were determined. We also obtained the coupling constant $$ \bar{u} $$ by analyzing the coexistence curve data with crossover theory. These parameters were used to test some universal amplitude ratios and together with the coexistence-curve data to test the complete scaling theory. It is shown that the contribution from heat capacity plays an important role in describing the asymmetric criticality of the coexistence curve. [ABSTRACT FROM AUTHOR]

In this study, 60 crushed samples comprising four groups of particles of different sizes were used to simulate the porous and crushed conditions of a gob area in an underground mine. Size distribution, porosity range, and the ratio of wavelength to the particle size of the crushed samples were taken into account with reference to the field observations in the actual gob. The ultrasonic wave velocity and attenuation were measured at an expected porosity under a loading pressure. Meanwhile, the permeability of the samples in the same conditions as the wave measurement was measured using the steady-state method. The results showed that the P-wave velocity of the crushed material was in the range of 400–1000 m/s, which was similar to the velocity of the fractured rock in the actual gob. The model for estimating the seismic attenuation of the crushed rock was confirmed to be a function of the porosity (φ), the density of discontinuity (δ), transmission coefficient (ζ), wave frequency (f), and the scatter factor (κ) proposed in the empirical formula based on the equipment results. The estimated seismic attenuation was consistent with the measurements in the experiment as well as the actual value based on previous study. In particular, the estimation was quite accurate, while the ratio of wavelength (λ) to particle size (dm) was between 35 and 65. The estimated permeability of the crushed rock mass fell into a magnitude range of 10−12 to 10−13 m2. The permeability showed consistency with the Kozney–Carman equation but with a larger tortuosity coefficient. The field gob permeability estimated by the laboratory correlation was from 1225 to 15,866 10−12 m2, showing good agreement with the previous research. The relationship between the permeability and the seismic attenuation of the crushed rock was established based on the measurements. [ABSTRACT FROM AUTHOR]

Gold nanostructures and a Nafion modified screen-printed carbon electrode (Nafion/AuNS/SPCE) were developed to assess the cell viability of Parkinson's disease (PD) cell models. The electrochemical measurement of cell viability was reflected by catecholamine neurotransmitter (represented by dopamine) secretion capacity, followed by a traditional tetrazolium-based colorimetric assay for confirmation. Due to the capacity to synthesize, store, and release catecholamines as well as their unlimited homogeneous proliferation, and ease of manipulation, pheochromocytoma (PC12) cells were used for PD cell modeling. Commercial low-differentiated and highly-differentiated PC12 cells, and home-made nerve growth factor (NGF) induced low-differentiated PC12 cells (NGF-differentiated PC12 cells) were included in the modeling. This approach achieved sensitive and rapid determination of cellular modeling and intervention states. Notably, among the three cell lines, NGF-differentiated PC12 cells displayed the enhanced neurotransmitter secretion level accompanied with attenuated growth rate, incremental dendrites in number and length that were highly resemble with neurons. Therefore, it was selected as the PD-tailorable modeling cell line. In short, the electrochemical sensor can be used to sensitively determine the biological function of neuron-like PC12 cells with negligible destruction and to explore the protective and regenerative impact of various substances on nerve cell model. [ABSTRACT FROM AUTHOR]

This study investigates the correlation between previous coal mine safety policies and accidents in China. Data on coal mine accidents and government regulatory information from 2008 to 2021 are collected. The characteristics of coal mine accidents are analyzed, and safety policy indexes are identified. An ordinary least squares (OLS) regression model is established to quantitatively analyze the correlation between accidents and safety policy. The study finds that safety policies have some impact on accident occurrence in coal mines. Although there has been a decrease in accidents and deaths over time, higher mortality rates are observed during periods of increased production intensity and on weekends. Gas accidents are the most common, followed by roof and flood accidents. The study concludes that national safety policies with wider coverage and a stronger system are effective in preventing accidents, but caution should be exercised to avoid reduced vigilance with decreasing death rates. [ABSTRACT FROM AUTHOR]

In recent years, electrochemiluminescence resonance energy transfer (ECL-RET) with low background signal and high specificity has attracted much attention among researchers. Herein, we established a novel ECL-RET biosensor for PML/RARα fusion gene detection. In this ECL-RET system, carbon dots (CDs) with low toxicity and prominent electrochemical activity were used as donor and Au@Ag2S core–shell nanoparticles (Au@Ag2S NPs) were employed as ECL acceptor. The Au@Ag2S NPs possessed a wide ultraviolet-visible (UV-vis) absorption spectrum between 500 nm and 700 nm, which completely overlapped with the ECL spectrum of CDs. Furthermore, the CDs-decorated poly-amidoamine/reduced graphene oxide (CDs/PAMAM/rGO) nanocomposites were prepared to improve the ECL signals and served as a substrate to stably load capture probe deoxyribonucleic acid (DNA). Based on the ECL-RET biosensing strategy, the Au@Ag2S NPs-labeled assistant probes and target DNA could pair with capture probes to form the sandwich-type DNA structure and the distance between donor and accepter was closed, leading to quenching of the ECL signal of CDs. The ECL-RET biosensor represented eminent analytical performance for PML/RARα fusion gene detection with a wide linear relationship from 5 fM to 500 pM and a low detection limit of 0.72 fM, which provided a novel technical means and theoretical basis for detection and diagnosis of acute promyelocytic leukemia. [ABSTRACT FROM AUTHOR]

To comprehensively understand the mechanical response of a rock-coal combination structure containing a weak layer, a series of laboratory static loading and impact loading experiments were conducted. The results showed that under static load, the sliding process of the rock coal structure was relatively slow, and fragments can be observed. Under the action of horizontal impact loading, the whole coal stratum slipped out rapidly, and the process lasted only 0.05 s. Under the horizontal and axial impact loads, the coal stratum remained stable first, and then it slipped out as a whole under the action of static load. Additionally, a sliding instability criterion of a rock coal structure containing a weak layer was established based on theoretical analysis. The key parameter P value was checked through a numerical simulation experiment. It was found that the value was linearly related to the mechanical properties of the weak layer and overburden stress, and the experimental results coincided with the theoretical results. Finally, the relationship between sliding rockburst and strain rockburst was discussed, and these results can provide an important scientific basis for the prevention and control of dynamic disasters in deep mining. [ABSTRACT FROM AUTHOR]

In the present study, numerical and experimental methods were used to investigate the effects of the process parameters on the enrichment of primary Si by separation of hypereutectic Ti-89 wt.% Si alloy melts during directional solidification. The results indicated that the separation of the primary Si from Ti-89 wt% Si alloy melts significantly depends on the pull-down rate of the melts, and the flow velocity of the melts decreases as the pull-down rate increases, which reduces the separation and enrichment effects of the primary Si during the electromagnetic directional solidification process. Conversely, with the increase in power, the convection and heat transfer of the melt are enhanced, which promotes the separation and enrichment of primary Si. Furthermore, the enrichment of silicon was analyzed by ICP (Inductive coupled plasma emission spectrometer), and it was found that with the power increasing from 3.8 to 5.4 kW, the content of Ti in the silicon enrichment layer decreased from 4.16 to 2.08%. [ABSTRACT FROM AUTHOR]

For the outside cabin heat exchanger of wind power generation, the overall numerical simulation plays an important role in its design and optimization. The periodic iterative simulation method proposed in this paper makes up for the deficiency of analogy research using the local model in the previous research of plate-fin heat exchanger so that the research conclusions can be directly applied to practical engineering. The effectiveness of this method is verified by comparing 10 groups of simulation results with experimental results. It is concluded that the maximum relative error of the periodic iterative simulation method is 0.9%, which meets the requirements of engineering calculation. The number of iterations can be reduced to two when only the outlet average temperature is involved, which is more convenient than the dozens of iterations. Furthermore, the effects of altitude, air velocity, air temperature, wave fin structure parameters, and generator power on the performance of heat exchanger are comprehensively analyzed. The results show that larger naturally captured air volume, lower ambient temperature, and lower altitude can effectively reduce the outlet temperature of ethylene glycol solution. When the amplitude and wavelength of the corrugated fin on the airside of the heat exchanger are 0.6 mm and 20 mm respectively, the naturally captured air volume is effectively increased, the overall heat exchange performance of the heat exchanger is further improved. [ABSTRACT FROM AUTHOR]

We report on the proof-of-principle of an amperometric method to monitor the progress of a polymerase chain reaction (PCR) in real-time. It is based on the finding that the intercalating redox probe Methylene Blue (MB) becomes less easily electrochemically detectable once intercalated into double-stranded DNA (ds-DNA) compared to its free form. This was studied by cyclic voltammetry before and after addition of salmon sperm ds-DNA. Under optimized conditions, the products of the PCR of mitochondrial DNA fragments were quantitatively detected at different stages of amplification cycles. This strategy is potentially cheaper and easier to integrate into a hand-held miniaturized device than fluorescence-based real-time PCR. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

The mechanisms of the rhodium-catalyzed cycloaddition of 2-vinylphenol with diphenylacetylene and carbon monoxide have been studied using density functional theory calculations at the B3LYP/6-31G (d, p) (Lanl2dz for Rh) level of theory. The SMD solvation model was used in MeCN solvents at M06-2X/6-311 ++ G (d, p) (Lanl2dz (f) for Rh) levels using a single-point calculation to consider the solvent effect. The calculation results show that there are two competitive reaction pathways for the cycloaddition reaction of rhodium-catalyzed synthesis of benzohexine and coumarin. Starting from the precursor reaction complex, the reaction channel is more favorable for the carbon atoms of diphenylacetylene and carbon monoxide to attack the Rh–C bond (the barriers of 9.88 and 10.01 kcal/mol) rather than attack the Rh–O bond (the barriers of 15.37 and 30.17 kcal/mol), and carbon monoxide in two different reaction channels has a greater energy difference than diphenylacetylene. The results show that the computational study of the rhodium-catalyzed cycloaddition reaction has a high catalytic activity consistent with the high yield of the experiment of Gulías et al. [ABSTRACT FROM AUTHOR]

DFT calculations at the M06-2X level were performed to explore the reaction mechanism for the synthesis of the new cyclometalated iridium(III) complexes with acyclic diaminocarbene ancillary ligands. The solvent effects of the reaction systems have been considered by a single-point energy calculation using the SMD model in the experimental conditions of CH2Cl2 solvent. The calculated results show that the reaction consists of two main steps: the first step is the hydrogen transfer between the two N atoms, and the next step is the closed-loop process of the Ir atom and the aromatic ring ortho to release the HCl molecule. The reaction has a relatively low activation free energy of 17.1–23.2 kcal mol−1, indicating that it is easy to occur under the experimental conditions of Na et al. At the same time, it was found that the aryl para-CF3 substituent has higher reactivity than the corresponding reactant of the NO2 substituent. [ABSTRACT FROM AUTHOR]

A neotype electrochemical sensor based on a three-dimensional nanoporous gold (3D-NPG) electrode decorated with ultra-thin platinum nanoparticles (Pt NPs) was fabricated for high-performance electrocatalysis and sensitive determination of hydrogen peroxide (H2O2) released from pheochromocytoma (PC12) cells. The monodisperse Pt–Au bimetallic nanoporous (Pt–Au–BNP) electrode prepared by cyclic voltammetry electrodepositing monolayer Pt NPs on the surface of the 3D-NPG electrode was characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and energy-dispersive spectroscopy (EDS). Amperometric response for H2O2 measurement was chosen at an applied potential of − 0.4 V. Upon optimal conditions, the wide linear range for the amperometric determination of H2O2 was from 0.05 μM to 7.37 mM, with a limit of detection (S/N = 3) of 1.5 × 10−8 mol/L and a high sensitivity of 1.125 μA μM−1 cm−2, certifying the large electrocatalytic action of the Pt–Au–BNP electrode. The proposed sensor has been successfully applied to the dynamic determination of H2O2 released from PC12 cells (from which the H2O2 generated by each cell was about 52.5 amol) with negligible interference. Thus, the proposed new electrochemical sensor displays potential applications for the dynamic, real-time monitoring of key small molecules secreted by living cells, further deepening the understanding of cell behavior stimulated by foreign materials. [ABSTRACT FROM AUTHOR]

The reaction mechanism of Ru-catalyzed cycloisomerization of 2-alkynylanilides to 3-substituted indole or 2-substituted indole was analyzed at the B3LYP level of density functional theory. The solvation effect of the system was also considered by SMD model. The calculation results show that the reaction system first forms a ruthenium π-alkyne complex. On the one hand, the cyclization reaction of the amino group and the alkyne carbon in the reaction precursor complex directly forms the 2-substituted indole product. On the other hand, the benzene ring in the reaction complex undergoes 1,2-carbon migration on the C≡C triple bond to form the vinylidene complex. After cyclization and hydrogen transfer, the catalyst is regenerated to obtain 3-substituted indole product. The latter reaction process has relatively lower activation free energy and is also the main reaction channel for this reaction, which is consistent with published experimental results. This study provides a reasonable reaction mechanism and effective experimental supplement. [ABSTRACT FROM AUTHOR]