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As a kind of microplasma sustained in air, solution electrode glow discharge (SEGD) ignited between the liquid electrode and metal electrode is attractive to the fields of optical emission spectrometry and mass spectrometry due to its unique advantages, such as low power consumption and low carrier gas consumption. Moreover, the complex and efficient reactions in the liquid phase and plasma phase of SEGD make it considerable research potential in the fields of biology and medicine, material synthesis, electrochemistry. Considering the close relationship between the various fields on SEGD, here we are devoted to provide an overview of the development of SEGD in various fields. More importantly, a systematic discussion on the discharge mechanism is conducted based on the research process in various fields for getting deeper insight into the SEGD.

In this paper, the first demonstration of direct ultratrace determination of lead in a single human hair by direct current-atmospheric pressure glow discharge-atomic emission spectrometry (DC-APGD-AES) coupled with electromagnetic heating vaporization (EMV) was described. Only the ultramicro mass of a human hair sample (about 0.15 mg, often a single human hair) was required during the analysis, and fast detection was implemented without tedious pretreatment processes, such as grinding and digestion. A limit of detection (LOD) of 30.8 μg kg-1 (4.8 pg) for Pb was obtained under optimized conditions, which was even equivalent to that of conventional LA-ICP-MS/ETV-ICP-MS/GFAAS. EMV-APGD-AES, meanwhile, can facilitate miniaturization and portability with low power and small size. The accuracy and practicality of the method were verified by the analysis of certified reference materials (CRMs) GBW09101b (human hair) and human hair samples from three volunteers. A simple, efficient, and low-cost method for detecting Pb in human hair has been developed.

With the advent of the information age, people have higher requirements for basic algorithms. Meta-heuristic algorithms have received wide attention as a high-level strategy to study and generate fully optimized solutions to data-driven optimization problems. Using the advantage of equilibrium optimizer (EO) with better balance mode, combined with the strategy of memetic algorithm, different proportion of temperature is introduced in different stages. That is, EO and thermal exchange optimization (TEO) are fused to obtain a new highly balanced optimizer (HEO). While keeping the guiding strategy and memory mode unchanged of EO, the accuracy of optimization is greatly improved. 14 well-known benchmark functions and 7 selective algorithms were used for HEO evaluation comparison experiments. On the basis of the fitness function curve, the optimal solution and other experimental data are tested statistically. The experimental results show that the improved algorithm has high accuracy and stability, but at the cost of running a little more time. Application testing of complex engineering problems is also one of the main purposes of algorithm design. In this paper, three typical engineering design problems (three truss, welded beam and rolling bearing design) are tested and the experimental results show that this algorithm has certain competitiveness and superiority in classical engineering design.

An innovative method for the ultrasensitive detection of mercury by solution anode glow discharge atomic emission spectroscopy (SAGD-AES) coupled with hydride generation (HG) was first investigated. In this method, the mercury vapor generated by the HG was transmitted to the SAGD through the miniature hollow tungsten tube for excitation and detected by a miniaturized spectrograph. A thorough parametric evaluation of the HG and SAGD system was performed, including the type and concentration of carrier acid, He flow rate, concentrations of NaBH4, discharge current and discharge gap. Under optimal operating conditions, the detection limit for Hg2+ achieved 0.03 μg/L, with a relative standard deviation of 1.1% at the Hg2+ concentration of 5 μg/L. Moreover, the correlation coefficient of the calibration curve was 0.9996 in the range between 0.1 and 10 μg/L. The accuracy and practicability of HG-SAGD-AES were verified by measuring GBW09101b (human hair), GBW10029 (fish), soil and rice samples. The results showed good agreement with the certified values and values from direct mercury analyzer (DMA).

Medical image segmentation is a hotspot in the field of image segmentation, and there are many segmentation methods. As a method of image segmentation, pulse coupled neural network (PCNN) has excellent segmentation effect. Of course, it also reduces the efficiency and effect of segmentation because of the complexity of parameter setting and the need for manual setting. This paper presents a method of searching simplified PCNN parameters by using Harris Hawks optimization (HHO) algorithm. For one thing the number of parameters of PCNN is reduced without affecting the segmentation effect, for another the corresponding parameters of PCNN are searched quickly and accurately by intelligent optimization algorithm. Then, image entropy (H) and mutual information entropy (MI) are introduced as fitness functions. The performance of HHO-PCNN is compared with WOA-PCNN, SCA-PCNN, SSA-PCNN, PSO-PCNN, GWO-PCNN, MVO-PCNN, Otsu and K-means by performance indicators (UM, CM, Precision, Recall, and Dice). The experimental results verify the superiority of this method in image segmentation.

An ultra-sensitive solution cathode glow discharge-optical emission spectrometry (SCGD-OES) method coupled with hydride generation (HG) for the determination of antimony valence is described. Through masking Sb(V) with citric acid in HCl medium, stibine from Sb(III) was selectively generated in a hydride generation system. Total antimony was determined after reducing Sb(V) to Sb(III) with 0.3% L-cysteine in 0.01 mol L−1 HCl. The Sb(V) concentration was calculated from the difference between total antimony and Sb(III). The main operational parameters and sources of potential interference that affect the determination were optimized with Sb(III) standard solution. The limits of detection (LODs) were 0.39 and 0.36 ng mL−1 for Sb(III) and total antimony, respectively, and the RSDs were 2.1 and 1.7% at the 10 ng mL−1 level, respectively. This method was applied for determining the valence of antimony in real water samples, and recovery experiments for different amounts of analytes were carried out. The recoveries were all in the range of 96.2–103.2% and were in good agreement with the corresponding ICP-MS values.

Multilevel thresholding is a simple and powerful image segmentation method that has received widespread attention in recent years. However, the accuracy and stability of thresholding techniques are still not ideal and cannot meet the needs of engineering problems. Therefore, this paper presents a memetic algorithm of dragonfly algorithm (DA) and differential evolution (DE) for color image segmentation, which is known as improved DA (IDA). On the one hand, DA algorithm has a satisfied capability of avoiding convergence to the local optimum, thus it is served as a global search technique. On the other hand, the DE algorithm is adopted as a local search technique, which can increase the precision of solutions. In this paper, two thresholding techniques, namely, Otsu and minimum cross entropy (MCE) methods are used to determine the optimal threshold values. In order to evaluate the performance of the proposed method, we conduct a series of experiments on color images from the Berkeley database and the results are compared with five state-of-the-art meta-heuristic algorithms. Besides, a non-parametric Wilcoxon's rank sum test is also included for statistical analysis. From the experimental results, it is found that IDA-based method outperforms other compared methods in terms of average fitness values, standard deviation, peak signal to noise ratio, structural similarity index, and feature similarity index. The promising results indicate that the application of IDA-based thresholding technique is potential and meaningful.

In this study, miniaturized optical emission spectrometry (OES) based on solution cathode glow discharge (SCGD) was developed for the determination of metal elements in samples. By redesigning and integrating the entire device, it can be controlled at the computer end to achieve automatic detection and analysis with battery power. The detection process does not require complex pretreatment of liquid samples, thereby enabling analysis in an environmentally friendly manner. A series of parameters affecting the analysis process were investigated. Without separation or enrichment of the analyte, the proposed SCGD-OES instrument could analyze Cd, Hg and Pb simultaneously, with detection limits (DLs) in the range of 33–253 μg L−1 (flow injection mode) and 7–92 μg L−1 (continuous flow mode). The calibration curves for Cd, Hg and Pb were linear in the concentration range of 2–50 μg mL−1. The instrument was successfully applied to certified reference materials (CRMs), and tap water, and seawater samples. The experimental results demonstrated the accuracy and practicality of the instrument.

Multithreshold segmentation is an indispensable part of modern image processing. Color images contain more information than gray images, therefore RGB multi-thresholding segmentation techniques have been drawn much attention during recent years. Multiverse optimization (MVO) algorithm has a strong advantage in finding the optimal solution of three channels for RGB. In this paper, an MVO algorithm based on Levy flight (LMVO) is proposed. Levy flight is an efficient strategy which can not only increase the population diversity to prevent premature convergence but also improve the ability to jump out of the local optimum. Therefore, LMVO conduces to achieve a better balance between exploration and exploitation of MVO, so that it is faster and more robust than MVO and avoids premature convergence. Further LMVO algorithm is compared with the other eight famous meta-heuristics algorithms, by maximizing the objective function of Kapur's entropy method or of Otsu method to determine the optimal threshold. The maximum objective function, peak signal-to-noise ratio (PSNR), feature similarity index (FSIM), structural similarity index (SSIM), CPU calculation time, optimal threshold value, and Wilcoxon's rank-sum test are used to evaluate the quality of the segmented image. The experimental results show that this method has obvious advantages in terms of objective function value, image quality measurement, convergence performance, and robustness.

Multithreshold segmentation of color images is an important part of modern image processing. Multithreshold segmentation techniques that use the ideas of optimization in mathematics to process the information contained in the three channels of RGB images have received much attention in recent years. In this paper, a hybrid algorithm of multiverse optimization algorithm with a gravitational search algorithm (GSMVO) is proposed. On the one hand, the gravitational mechanism among individuals in the universe enables particles to share information and move toward particles with large mass (the optimal solution), thus optimizing local optimization. On the other hand, the problem of a slow interpopulation update is improved. On the premise of improving the optimization precision, the convergence speed of the whole system is accelerated and the robustness can be improved. The time complexity of a proposed hybrid algorithm is analyzed. The quality of a segmented image is evaluated by using peak signal-to-noise ratio (PSNR), feature similarity index (FSIM), structural similarity index (SSIM), and Wilcoxon test. The experimental results illustrate that the proposed method has obvious advantages in objective function value, image quality measurement, convergence performance, and robustness.

Multilevel thresholding is an important approach for image segmentation which has drawn much attention during the past few years. The Tsallis entropy method is implemented for its effectiveness and simplicity. Although it is efficient and gives an excellent result in the case of bi-level thresholding, its evaluation becomes complexity when the number of thresholds increases. To overcome the problem, the metaheuristic algorithms are applied in this search area for searching the optimal thresholds. In this paper, a modified grasshopper optimization algorithm (GOA) is adopted to render multilevel Tsallis cross entropy more practical and reduce the complexity. The Levy flight algorithm is employed to modify the original GOA and balance the exploration and exploitation of the GOA. Experiments are conducted between five state-of-the-art metaheuristic algorithms and the proposed one. In addition, the proposed approach is compared with thresholding techniques depending on between-class variance (Otsu) method and the Renyi entropy function. Both real life images and plant stomata images are used in the experiments to test the performance of the algorithms involved. Qualitative experimental results show that the proposed segmentation approach has a fewer iterations and a higher segmentation accuracy.

The purpose of this paper is to propose a new hybrid metaheuristic to solve the problem of feature selection. Feature selection problem is the process of finding the most relevant subset based on some criteria. A hybrid metaheuristic is a new trend in the development of optimization algorithms. In this paper, two different hybrid models are designed based on spotted hyena optimization (SHO) for feature selection problem. The SHO algorithm can find the optimal or nearly optimal feature subset in the feature space to minimize the given fitness function. In the first model, the simulated annealing algorithm (SA) is embedded in the SHO algorithm (called SHOSA-1) to enhance the optimal solution found by the SHO algorithm after each iteration. In the second model, SA enhances the final solution obtained by the SHO algorithm (called SHOSA-2). The performance of these methods is evaluated in 20 datasets in the UCI repository. The experiments show that SHOSA-1 performs better than the native algorithm and SHOSA-2. And then, SHOSA-1 is compared with six state-of-the-art optimization algorithms. The experimental results confirm that SHOSA-1 improves the classification accuracy and reduces the number of selected features compared with other wrapper-based optimization algorithms. That proves the excellent performance of SHOSA-1 in spatial search and feature attribute selection.

The assembly of primordial follicles in mammals represents one of the most critical processes in ovarian biology. It directly affects the number of oocytes available to a female throughout her reproductive life. Premature depletion of primordial follicles contributes to the ovarian pathology primary ovarian insufficiency (POI). To delineate the developmental trajectory and regulatory mechanisms of oocytes during the process, we performed RNA‐seq on single germ cells from newborn (P0.5) ovaries. Three cell clusters were classified which corresponded to three cell states (germ cell cyst, cyst breakdown, and follicle) in the newborn ovary. By Monocle analysis, a uniform trajectory of oocyte development was built with a series of genes showed dynamic changes along the pseudo‐timeline. Gene Ontology term enrichment revealed a significant decrease in meiosis‐related genes and a dramatic increase in oocyte‐specific genes which marked the transition from a germ cell to a functional oocyte. We then established a network of regulons by using single‐cell regulatory network inference and clustering (SCENIC) algorithm and identified possible candidate transcription factors that may maintain transcription programs during follicle formation. Following functional studies further revealed the differential regulation of the identified regulon Id2 and its family member Id1, on the establishment of primordial follicle pool by using siRNA knockdown and genetic modified mouse models. In summary, our study systematically reconstructed molecular cascades in oocytes and identified a series of genes and molecular pathways in follicle formation and development., The assembly of primordial follicle determines the number of oocytes available to a female throughout her reproductive life. Premature depletion of primordial follicles contributes to the ovarian pathology primary ovarian insufficiency. We performed RNA‐seq on single germ cells from newborn mouse ovary and the data revealed dynamic gene expressions along with the transition of germ cells to a functional oocyte. Our study highlights the importance of transcriptional regulations on the process.

A device utilizing atmospheric pressure glow discharge as the second excitation source coupled with laser ablation (LA) for direct solid sampling was developed, with few operating costs and low gas consumption. This new device was first utilized for the highly sensitive determination of Zn, Pb, and Cd elements in complex matrix soil samples. It also provided a new method for monitoring these three trace elements in soil samples. Good linearity was observed in the quantitative results for Zn, Pb, and Cd detection, and the respective linear correlation coefficients (R2) were 0.9953, 0.9897, and 0.9961. Moreover, the limit of detection (LOD) of 0.68, 2.71, and 0.31 mg kg−1 were achieved for Zn, Pb, and Cd, respectively; the LOD of Zn reduced by more than one order of magnitude compared to that observed in laser-induced breakdown spectroscopy results. In addition, the quantitative analysis results showed good agreement with the certified values and those obtained of ICP optical emission spectrometry, proving the detection accuracy and practicability of the developed device.

A simple and ultra-sensitive method for the determination of inorganic arsenic valence was developed by solution cathode glow discharge atomic emission spectrometry (SCGD-AES) coupled with hydride generation (HG). Arsenic was converted into volatile hydrides by the reaction with NaBH4 and HCl, after which they were delivered and subsequently injected into the near-anode region of the SCGD, where they were detected directly by atomic emission spectrometry (AES). The detection limit (DL) for arsenic was improved by four orders of magnitude compared to the single SCGD-AES process. The main operational parameters and sources of potential interference that affect the determination of arsenic were thoroughly studied. Under optimal conditions, the DLs for As(III) and As(V) were both calculated to be 0.3 μg L−1. Repeatability, expressed as the relative standard deviation of the spectral peak height, was 2.5% (n = 11) for a 0.1 mg L−1 arsenic solution. The proposed method was validated by the determination of a certified reference material (NIST SRM 1568a) and was applied to the real rice samples, where the measurement results obtained by the HG-SCGD-AES method were in good agreement with the reference values or values from hydride generation atomic fluorescence spectrometry.

We herein report the development of a compact and robust optical emission spectrometry (OES)-based technique for the ultrasensitive determination of Se and As utilizing hydride generation (HG) as the sampling technique and direct-current atmospheric pressure glow discharge in He (APGD) as the radiation source. The emission sensitivities of 50 ng mL-1 Se and As in the newly designed HG-APGD were enhanced more than 3-fold by constraining the spatial volume between two hollow-tube APGD electrodes, and the stability was significantly improved. The developed technique achieved Se and As detection limits of 0.13 and 0.087 ng mL-1, respectively, with the corresponding relative standard deviations at analyte concentrations of 50 ng mL-1 being

An ultrasensitive method for the determination of Pb was developed by coupling solution anode glow discharge–optical emission spectrometry (SAGD-OES) with hydride generation (HG). Compared to solution cathode glow discharge, the introduction of analytes yielded via HG from the discharge cathode into the microplasma was demonstrated to be easily performed by SAGD in which the gas jet nozzle served as cathode and further enhanced sensitivity for Pb determination was achieved. The susceptibility of SAGD-OES to the matrix-induced interferences in the analysis of real samples was significantly improved owing to the coupling of HG. After a thorough optimization of the HG-SAGD-OES system parameters, the developed system achieved Pb detection limit of 0.061 ng mL−1, with the corresponding relative standard deviation being

A novel environment friendly adsorbent, magnetic calcinated cobalt ferrite/magnesium aluminum hydrotalcite composite (CoFe2O4/MgAl-LDO) was prepared through coprecipitation method and employed for methyl orange (MO) removal from aqueous solutions. The physicochemical properties of CoFe2O4/MgAl-LDO were characterized and its adsorption properties for MO removal under different conditions were investigated systematically. The results indicated that the adsorbent exhibited a high MO removal efficiency in a wide range of initial pH of 2.0–12.0 and high selectivity for MO versus common co-existing ions. The MO adsorption rate of the adsorbent was very fast, and the adsorption kinetics followed pseudo-first-order model. The adsorption isotherm could be well fitted in Langmuir model, while the maximum adsorption capacity was found to be 1219.5 mg/g at pH 6.0, which was much higher than the MO adsorption capacity of for most reported adsorbents. Thermodynamics data revealed the exothermic and spontaneous nature of the adsorption process. The regeneration of the adsorbent could be easily achieved through thermal treatment. After three cycles, the MO removal efficiency of CoFe2O4/MgAl-LDO still remained high. The efficient MO removal and easy magnetic separation makes CoFe2O4/MgAl-LDO be a promising adsorbent for effective removal of dyes from aqueous solutions.

Herein, we propose a simplified design for a solution anode glow discharge-atomic emission spectrometry (SAGD-AES) device for determination of Ag, Bi, Cd, Hg, Pb, Tl, and Zn concentrations in solutions with high sensitivity. Using a Ti rod as the cathode, the need for a cooling device and noble gas environment was eliminated, which would enable the miniaturization of the device in the future. Moreover, the quartz tube in the device was directly connected to the graphite rod to eliminate the need to maintain a constant sample solution level in the device during discharge. A thorough parametric evaluation of the proposed SAGD-AES for heavy metal determination was performed. Our proposed SAGD-AES device achieved detection limits of 0.03, 1.98, 0.07, 1.7, 1.35, 0.02, and 0.12 μg L−1 for Ag, Bi, Cd, Hg, Pb, Tl, and Zn, respectively, with the corresponding relative standard deviations for analyte concentrations of 10 μg L−1 (Ag, Cd, Tl, Zn) and 200 μg L−1 (Bi, Hg, Pb) being

Magnetic materials as adsorbents can provide effective removal and quickly separate pollutants in wastewater treatment. A magnetic CoFe2O4/MgAl-LDH composite was successfully synthesized through a low saturation coprecipitation method. The adsorption behaviors of Cr(VI) from an aqueous solution by CoFe2O4/MgAl-LDH were investigated. The adsorbents were characterized using scanning electron microscopy (SEM), N2 adsorption–desorption isotherms, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). Kinetic and equilibrium studies indicated that the experimental data of Cr(VI) adsorption were best described by pseudo-second-order kinetic and Langmuir models. The maximum adsorption capacity of CoFe2O4/MgAl-LDH for Cr(VI) was found to be 72.4 mg g−1 at an equilibrium time of 300 min and temperature of 283 K. Evaluation of the thermodynamics parameters (ΔH < 0, ΔS < 0 and ΔG < 0) revealed the adsorption process was exothermic and spontaneous. The mechanism study showed that the adsorption of Cr(VI) onto CoFe2O4/MgAl-LDH likely involved adsorption/surface complexation and an ion exchange interaction. This study demonstrated that the magnetic CoFe2O4/MgAl-LDH composite was an effective adsorbent for Cr(VI) removal with quick separation.

The rate-dependent hysteresis in giant magnetostrictive actuators(GMA) is a major impediment to the engineering application. In this paper, a rate-dependent modified Prandtl-Ishlinskii(RDMPI) model is proposed to characterize the rate-dependent hysteresis nonlinearity of GMA. The new model is based on the modified Prandtl-Ishlinskii(MPI) model combined with the dynamic weight and dynamic threshold. Simulation results show that the proposed model effectively represents the characterization of the GMA's rate-dependent hysteresis nonlinearity within a range of frequency.

Summary Although age-related ovarian failure in female mammals cannot be reversed, recent strategies have focused on improving reproductive capacity with age, and rapamycin is one such intervention that has shown a potential for preserving the ovarian follicle pool and preventing premature ovarian failure. However, the application is limited because of its detrimental effects on follicular development and ovulation during long-term treatment. Herein, we shortened the rapamycin administration to 2 weeks and applied the protocol to both young (8 weeks) and middle-aged (8 months) mouse models. Results showed disturbances in ovarian function during and shortly after treatment; however, all the treated animals returned to normal fertility 2 months later. Following natural mating, we observed prolongation of ovarian lifespan in both mouse models, with the most prominent effect occurring in mice older than 12 months. The effects of transient rapamycin treatment on ovarian lifespan were reflected in the preservation of primordial follicles, increases in oocyte quality, and improvement in the ovarian microenvironment. These data indicate that short-term rapamycin treatment exhibits persistent effects on prolonging ovarian lifespan no matter the age at initiation of treatment. In order not to disturb fertility in young adults, investigators should in the future consider applying the protocol later in life so as to delay menopause in women, and at the same time increase ovarian lifespan.

We examine the electrodeposition of antimony (Sb), tellurium (Te) and their alloys from molten mixtures of acetamide - antimony chloride and tellurium chloride. The binary mixtures of acetamide with SbCl3 and TeCl 4 exhibit eutectic formation with large depressions of freezing points to below room temperature. At temperatures up to 100 °C, these mixtures are highly conductive and can be used to deposit elementary Sb and Te films at current density up to 7 A dm-2. Antimony telluride alloy films with composition between 20 and 81 at.% Te are obtained from ternary mixtures containing up to 0.48MSbCl3 and up to 0.12MTeCl4. Composition of the antimony telluride films can be controlled by adjusting bath composition and current density. cop. 2012 The Electrochemical Society.

Liver serine/threonine kinase B1 (LKB1) is a tumor suppressor associated with the pathogenesis of Peutz-Jeghers syndrome. Affected males are at increased risk of developing Sertoli cell tumors and display defective spermatogenesis. Male mice lacking the short isoform (Lkb1S) of Lkb1 were sterile and exhibited abnormal spermiogenesis. In addition to the short isoform, the long isoform of Lkb1 (Lkb1L) is also expressed in testis; however, the requirement of the long isoform for fertility and the functional difference between the isoforms remain unknown. Herein, different from the spermiation failure reported in Lkb1S knockout mice, conditional deletion (cKO) of both isoforms of Lkb1 in germ cells resulted in male sterility stemming from defects in acrosome formation, as well as nuclear elongation and condensation during spermatid differentiation. Additionally, cKO mice showed a progressive germ cell loss that was never reported in mice with Lkb1S deletion. Further experiments revealed that the defect resulted from the failure of spermatogonial stem/progenitor cells (SPCs) maintenance. Although increased mTORC1 activity in postnatal cKO testes was consistent with a tendency toward germline stem cell differentiation, in vivo inhibition of the pathway by rapamycin treatment failed to rescue the phenotype. Concurrently, we detected a significant reduction of mitochondrial activity in Lkb1deficient SPCs. The results suggest that the regulation of LKB1 on SPCs’ maintenance is associated with mitochondrial functions but not through the mTOR signaling pathway. In summary, our study supports different roles of Lkb1 isoforms in spermatogenesis with Lkb1L directing SPCs maintenance, and Lkb1L and Lkb1S coordinately regulating spermatid differentiation.

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