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The sea urchin is a very important aquatic economic organism in many countries and has high food value. However, it has recently been heavily fished, and it would be of great importance to the sustainable development of coral reefs to develop large-scale aquaculture of sea urchins. Sea urchins are prone to death during larval development. Therefore, in this study, three kinds of microalgae were used as the initial food for sea urchins to evaluate whether different kinds of microalgae can improve their survival and growth rates. Chaetoceros muelleri (C), Isochrysis galbana tml (I), and Dunaliella salina (D) were fed to A. crassipina at concentrations of 5000, 10,000, 20,000, and 30,000 cell mL−1. A fasted group was used as control (N). The final body length, final body width, final stomach length, rudiment length, survival rate and morphology were measured to evaluate development and growth. The results showed that feeding with C. muelleri resulted in better growth and survival. After 9 days of feeding with C(20,000 cells mL−1), the rudiment length reached 203.33 ± 12.47 µm. The onset of metamorphosis was observed 12 days post-feeding. The survival rate after feeding C was also significantly higher than that after feeding I and D. In summary, when sea urchins are breeding, it is recommended to choose C(20,000 cells mL−1) or C(30,000 cells mL−1) as the initial feed for larvae to increase the growth and survival of sea urchin seedlings.

In recent years, climate change has often caused fluctuations in seawater salinity and temperature, which threaten the survival and growth of corals. Effectively improving the stress response to temperature and salinity changes in corals to prevent bleaching is one of the important issues. This study initially explored the use of artificial polyunsaturated fatty acids to assess the ability of Briareum violacea to slow bleaching, enhance growth, stabilize larval development and reduce antistress factors (superoxide dismutase and catalase) when they were exposed to temperature and salinity stress. The salinities used in the experiment were 25, 30, 35 and 40 psu, and the temperatures were 20, 25 and 30 °C. It was divided into two parts: Experiment 1—Effects of temperature and salinity and feeding on digestive enzymes, reproduction and stress response of B. violacea; Experiment 2—Effects of temperature and salinity and feeding on the settlement and survival of larvae. The results showed that the feeding treatment group reduced the superoxide dismutase, catalase and mortality of corals under stress and significantly improved larval development and larval settlement.

In recent years, ciliate infections have caused serious casualties to corals in the ocean. Infected corals die within a short period of time, which not only poses a threat to wild coral reefs, but also has a major impact on large scale aquaculture of coral. Clove is a kind of Chinese medicine with antifungal, antibacterial, antiviral, insecticidal, and other functions. Clove is a natural product. If it can be used in the treatment of coral ciliates, it will reduce this threat to the environment. The clove extract was diluted with sterile seawater to 500 ppm, 1500 ppm, 2500 ppm, 5000 ppm, 7500 ppm, and 10,000 ppm to carry out virulence test on ciliates. The results show that the LC50 value is 1500 ppm, which can cause the death of ciliates in 10 min without causing significant changes in G. columna SOD, CAT, chlorophyll a, and zooxanthellae. In addition, observation of tissue slices revealed that no ciliates and vacuum were found in the G. columna tissue after 10 min of medicated bathing. In summary, 1500 ppm of clove extract can be used for the treatment of coral ciliates.

Goniopora columna is a stony coral valued for its reef-building potential and its unique appearance. Thus, identifying the optimal culture conditions for G. columna would enable efficient cultivation and prevent the illegal exploitation of marine resources. Light sources are crucial for the growth of corals because zooxanthellae provide them with basic nutrients through photosynthesis. Different corals and zooxanthellae have different photoacclimation characteristics; therefore, selecting a suitable light wavelength remains the key inhibitor of coral maintenance in marine aquariums. Accordingly, this study investigated the effects of different light wavelengths on G. columna. It was illuminated for 6 or 12 h a day under white light, yellow light, red light (LR), green light (LG), blue light (LB), or purple light (LP) for 8 weeks. During the experiment, R(R; i.e., a formula feed that combines sodium alginate, protein and probiotics) of 5% (w/v) of G. columna tissue and skeletal dry weight was fed every day. Coral polyps were counted, zooxanthellae density, chlorophyll a concentration, specific growth rates, and survival rates were calculated; polyp stretching and contractile behaviors were observed; and body composition and digestive enzyme activity were analyzed. LB or LP (but not LG or LR) illumination for at least 6 h per day significantly promoted the growth, survival, protein content, and protease activity of the G. columna specimens. Furthermore, coral polyp extension reached 100% after 30 min of LP and LB light irradiation. Although no significant differences in the zooxanthellae density or chlorophyll a concentration were noted under various light wavelengths, significant reductions were detected in the absence of light. To achieve energy-efficient coral aquaculture with regard to G. columna cultivation, 6 h of LB or LP illumination per day can improve the growth.

In this paper, we discover an operation method that can effectively decrease the forming voltage in resistance random access memory (RRAM). Forming voltage can be reduced by either increasing the rising time of the forming-waveform or by increasing the temperature in the forming process. However, the resulting electronic RRAM characteristics after each of these methods differ. While increasing the rising time causes greater damage to the switching layer due to longer accumulation of charge, increasing temperature in the forming process does not. The high temperature-formed RRAM excels in retention and endurance tests, proving an effective means to decrease forming voltage.

Ciliate infection is a serious parasitic disease of coral. Infected coral rots and dies in a short time. In addition to killing corals by infecting them in the oceans, ciliate infection also poses a threat to corals farmed on a large scale. In this study, two antioxidant enzymes (SOD and CAT) were used to judge the stress response in Goniopora columna after infection, and KCl and H2O2 were used to evaluate the therapeutic effect. The results showed that SOD and CAT increased during the early stage of infection but decreased with the extension of infection time. In terms of drug therapy, it was found that the treatment of ciliate infection with 1.5% of KCl had no significant effect on SOD and CAT of G. columna. The morphological changes of zooxanthellae, chlorophyll a, and coral were not significant. H2O2 leads to a stress response and polyp contraction. In conclusion, 1.5% of KCl can be used in the selection of drugs to treat ciliate infection.

Nutritional requirements are critical in the process of coral aquaculture. In addition to energy from symbiotic algae, corals obtain sufficient nutrition through heterotrophic feeding. Microalgae and yeast are commonly used as nutritional supplements for many aquaculture organisms. In addition, if artificial feed can match or improve upon the nutritional supplementation provided by microalgae and yeast in the case of G. columna, then feeding this coral would be markedly easier. Hence, this article preliminarily discusses feeds suitable for G. columna. In this study, artificial PUFA rich in animal protein (R), Saccharomyces cerevisiae, Isochrysis galbana tml, and Nannochloropsis oculate were fed to G. columna at quantities of 5% and 10% of body weight. Growth, survival, body composition, and digestive enzymes were assessed. Regarding body composition, the coral’s protein content is higher than that of carbohydrate or fat; thus, evaluating the heterotrophic nutrition of G. columna by using protein absorption is appropriate. The protease content is also high in digestive enzymes. Protein content, protease activity, and specific growth rate were significantly higher in the R group than in other groups. The number of polyps in the groups fed R at 5% and 10% of body weight increased by 40.00 ± 2.43 and 47.33 ± 0.89 number, respectively, significantly greater increases than those achieved in the other groups (p < 0.05). Changes in body composition and digestive enzymes over a 24-h period were compared to determine the optimal feeding time. Protein content and protease activity increased markedly between 6:00 and 12:00. The experimental results suggest that R can improve the activity of G. columna digestive enzymes and their protein and lipid content in body tissue, shorten the cultivation time, and enhance the profitability of coral aquaculture.

The study aimed to examine whether urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) could serve as a biomarker for assessing sperm DNA integrity. Urine and semen samples were collected from 124 coke-oven workers, who had chronically been exposed to polycyclic aromatic hydrocarbons (PAHs), from a steel plant in Kaohsiung, Taiwan. The coke-oven workers were divided into two subgroups: topside-oven workers and side-oven workers. Sperm DNA integrity was assessed in terms of DNA fragmentation and 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodGuo). Urine samples were used to detect 1-hydroxypyrene (1-OHP) and urinary 8-OHdG, which served to assess exposure to PAHs and the whole body oxidative stress, respectively. Urinary 1-OHP concentrations were significantly higher in the topside-oven workers than the side-oven workers (p = 0.02). Sperm 8-oxodGuo concentrations were correlated with percentages of sperm fragmentation (p = 0.044), but urinary 8-OHdG levels failed to correlate with sperm 8-oxodGuo levels and with percentages of fragmentation. In conclusion, exposure to PAHs was linked to increased oxidative stress on sperm. However, urinary 8-OHdG may not be a suitable biomarker for examining sperm DNA damage associated with oxidative stress.

In this paper, an ITO/Ga2O3:ITO/TiN structured resistance random access memory is introduced. Either interface or filament conduction mechanism can be induced depending on the forming compliance current, which has not been investigated before. Material analyses and electrical I-V measurements on this ITO/Ga2O3:ITO/TiN have also been carried out. The interface conduction mechanism was confirmed by a size-effect experiment, where resistance varied inversely to via size. In addition, the current fitting results show that Schottky emission dominates the on- and off-state currents. All physical mechanisms of device resistive switching behaviors are explained by our models and also confirmed by I-V characteristics. [ABSTRACT FROM AUTHOR]

In this letter, we demonstrate completely different characteristics with different operating modes and analyze the electrical field effect to confirm the filament dissolution behavior. The device exhibited a larger memory window when using a single voltage sweep method during reset process rather than the traditional double sweep method. The phenomenon was verified by using fast I–V measurement to simulate the two operating methods. A better high resistance state (HRS) will be obtained with a very short rising time pulse, but quite notably, lower power consumption was needed. We proposed the electrical field effect to explain the phenomenon and demonstrate distribution by COMSOL simulation. [ABSTRACT FROM AUTHOR]

This study presents the dual bipolar resistive switching characteristics induced by oxygen-ion accumulation. By introducing nitrogen to the interface between the resistive switching region and active switching electrode, filament-type and interface-type resistive switching behaviors can both exist under different operation conditions. This particular oxygen-ion accumulation-induced switching behavior suggests an extraordinary potential for resistive random access memory applications because the operating power can be significantly decreased (about 100 times). The physical mechanism of this oxygen-ion accumulation-induced interface-type resistive switching behavior is explained by our model and clarified by current conduction mechanism and material analysis. [ABSTRACT FROM AUTHOR]

This study aimed to determine whether dietary carotenoid (CD) supplements could affect the antioxidant capacity of characins Hyphessobrycon callistus upon hypoxia stress at live transportation. Two types of CD [astaxanthin (AX), β-carotene (BC)] and their 1:1 combination (MX) at three concentrations (10, 20 and 40 mg kg−1) were supplemented, resulting in nine CD diets. After 8 weeks' rearing, the resulting fish were divided into two subgroups and exposed to hypoxia or normoxia. Hypoxia involved a gradual decrease in dissolved oxygen (DO) from 6.5 to <1.0 mg L−1. Normoxia was DO kept in saturation. Hypoxia led to an increase in the total antioxidant status (TAS), superoxide dismutase (SOD), glutathione peroxidases (GPx) and aspartate aminotransferase (AST) activity of blood serum in fish, but had no effect on alanine aminotransferase (ALT). Under hypoxia, fish fed CD diets had lower SOD, GPx and ALT activity than control fish, showing that dietary CD could increase the antioxidant capacity and protection of the liver. Dietary AX was more effective for antioxidant capacity than BC and MX when under hypoxia stress, because GPx, ALT and AST were lower in AX-fed fish. Except TAS, the other four enzyme activities showed decreasing trends with increasing dietary CD concentrations. [ABSTRACT FROM AUTHOR]

Investigating dynamic resistance switching behaviors is important for real applications for resistance random access memory (RRAM). In this study, we demonstrate a voltage induced positive-feedback effect which occurs during the reset process under specific conditions, and propose an explanatory mechanism. Since instantaneous change of current always appears with the self-compliance characteristic, research was carried out to clarify the mechanism. We found that the cause is a positive-feedback effect which induces a sudden change in the voltage allocation to the RRAM. A mathematical proof was also carried out to confirm this mechanism, and was used to predict reset behavior when under a specific condition. These experimental and simulation results can help provide a better understanding of the RRAM dynamic reset mechanism. [ABSTRACT FROM AUTHOR]

In this study, we demonstrate a forming technique that enables us to control whether the switching layer of a Pt/In2O3/TiN device is near the Pt electrode or the TiN electrode. This means that In2O3-based resistive random access memory (RRAM) can be switched at either the active or inert electrode. The resistive switching current–voltage (I–V) curves for both electrodes exhibit stable memory windows. Through material and electrical analyses, we found that the reason for switching at the inert electrode is the oxygen-vacancy-rich characteristic of In2O3. Finally, a physical model is proposed to explain this phenomenon. [ABSTRACT FROM AUTHOR]

The successful recovery of resistive switching random access memory (RRAM) devices that have undergone switching failure is achieved by introducing a low-temperature supercritical-fluid process that passivates the switching layer. These failed RRAM devices, which are incapable of switching between high- and low-resistance states, were treated with supercritical carbon dioxide with pure water at 120 °C for 1 h. After the treatment, the devices became operational again and showed excellent current–voltage (I–V) characteristics and reliability as before. On the basis of the current conduction mechanism fitting results, we propose a model to explain the phenomenon. [ABSTRACT FROM AUTHOR]

The forming process is a necessary and irreversible process to activate the resistance switching behavior in a resistance random access memory (RRAM) device. However, during the forming process, an overshoot current leads to device damage and causes inferior resistance switching characteristics; consequently, the process is considered to be a key factor in device degradation. In this paper, we find that a discontinuous conduction path can be formed by a pulse forming process such that the operation current can be reduced. We further investigate how the charge quantity during the forming process affects the carrier conduction mechanism of HRS, with all experiments and results demonstrated on one-transistor–one-resistor (1T1R) devices. [ABSTRACT FROM AUTHOR]

In this study, an adjustable built-in resistor was observed on an indium–tin oxide (ITO)-capped resistance random access memory (RRAM) device, which has the potential to reduce operating power. Quite notably, the high-resistance state (HRS) current of the device decreased with decreasing current compliance, and a special situation, that is, a gradual change in current always appears and climbs slowly to reach the compliance current in the set process even when the compliance current decreases, was observed. Owing to this observed phenomenon, the device is regarded to be equipped with an adjustable built-in resistor, which has the potential for low-power device application. [ABSTRACT FROM AUTHOR]

In this letter, we inserted a low dielectric constant (low-k) or high dielectric constant (high-k) material as a switching layer in indium–tin-oxide-based resistive random-access memory. After measuring the two samples, we found that the low-k material device has very low operating voltages (−80 and 110 mV for SET and RESET operations, respectively). Current fitting results were then used with the COMSOL software package to simulate electric field distribution in the layers. After combining the electrical measurement results with simulations, a conduction model was proposed to explain resistance switching behaviors in the two structures. [ABSTRACT FROM AUTHOR]

Identical insulators and bottom electrodes were fabricated and capped by an indium tin oxide (ITO) film, either undoped or doped with erbium (Er), as a top electrode. This distinctive top electrode dramatically altered the resistive random access memory (RRAM) characteristics, for example, lowering the operation current and enlarging the memory window. In addition, the RESET voltage increased, whereas the SET voltage remained almost the same. A conduction model of Er-doped ITO is proposed through current–voltage (I–V) measurement and current fitting to explain the resistance switching mechanism of Er-doped ITO RRAM and is confirmed by material analysis and reliability tests. [ABSTRACT FROM AUTHOR]