Under the stressed condition, a complex feedback mechanism for stress is activated to maintain homeostasis of the body and secretes several stress hormones. But these stress hormones impair synthesis and secretion of the reproductive hormones, followed by suppression of ovarian function. Cytochrome P450 1A2 (CYP1A2) plays a major role in metabolizing exogenous substances and endogenous hormones, and its expression is recently identified at not only the liver but also several organs with respect to the pancreas, lung and ovary. Although the expression of CYP1A2 can be also affected by several factors, understanding for the changed pattern of the ovarian CYP1A2 expression upon stress induction is still limited. Therefore, CYP1A2 expression in the ovaries from immobilization stress-induced rats were assessed in the present study. The stress-induced rats in the present study exhibited the physiological changes in terms of increased stress hormone level and decreased body weight gains. Under immunohistological observation, the ovarian CYP1A2 expression in both control and the stressed ovary was localized in the antral to pre-ovulatory follicles. However, its expression level was significantly (p < 0.01) higher in the stress-induced group than control group. In addition, stress-induced group presented more abundant CYP1A2-positive follicles (%) than control group. Since expression of the ovarian CYP1A2 was highly related with follicle atresia, increased expression of CYP1A2 in the stressed ovary might be associated with changes of the ovarian follicular dynamics due to stress induction. We hope that these findings have important implications in the fields of the reproductive biology.

Zinc oxide (ZnO) based transparent conducting oxides (TCO) thin films, are used in many applications such as solar cells, flat panel displays, and LEDs due to their wide bandgap nature and excellent electrical properties. In the present work, fluorine and aluminium-doped ZnO targets are prepared and thin films are deposited on soda-lime glass substrate using a RF magnetron sputtering unit. The aluminium concentration is fixed at 2 wt%, and the fluorine concentration is adjusted between 0 to 2.0 wt% with five different concentrations, namely, Al2ZnO98(AZO), F0.5AZO97.5(FAZO1), F1AZO97(FAZO2), F1.5AZO96.5(FAZO3), and F2AZO96(FAZO4). Thin films are deposited with an RF power of 40 W and working pressure of 5 m Torr at 270 oC. The morphological analysis performed for the thin film reveals that surface roughness decreases in FAZO1 and FAZO2 samples when doped with a small amount of fluorine. Further, optical and electrical properties measured for FAZO1 sample show average optical transmissions of over 89 % in the visible region and 82.5 % in the infrared region, followed by low resistivity and sheet resistance of 3.59 × 10−4 Ωcm and 5.52 Ω/sq, respectively. In future, these thin films with excellent optoelectronic properties can be used for thin-film solar cell and other optoelectronics applications.

The article summarises the status and competence of UJV Rez, a. s. (up to 2012, the Nuclear Research Institute Rez, Czech Republic) in the field of radioactive waste (RAW) management as a company managing of 95% of institutional radioactive wastes in Czech Republic. UJV Rez a. s. has been one of the Czech Republic’s key research and engineering institutions in the field of nuclear energy production since 1955. The company processes and conditions prior to storage 95% of so-called institutional RAW and is the principal partner of the state with respect to the research support of the Czech deep geological repository development project. UJV Rez a. s. boasts its own accredited radiochemical analytical test laboratory, unique of its kind in the Czech Republic. Of equal importance is UJV Rez’s active participation in a range of international organisations and associations and its involvement in wide range of international projects, and so as European projects. One of them is EU funded project PREDIS: Pre-disposal management of radioactive wastes, that has started at September 2020, focused on the field of low level radioactive waste (LLW) and intermediate level radioactive waste (ILW) pre-disposal.

We report on the one-step synthesis of luminescent carbon nanodots (C-dots) via an electrical discharge between two graphite electrodes submerged into organic solvent (octane). This is a simple approach for the fabrication of C-dots with tunable photoluminescence (PL) that differs from the other preparation methods, as no post-passivation step is required. The synthesized carbon nanoparticles are of spherical shape and their size is distributed in the range of 2–5 nm and exhibit luminescence sensitive to excitation wavelength.

Abstract Activated carbon from the shell of the cashew of Para (SCP) was produced by chemical activation with ZnCl using the ratio of SCP: ZnCl2 1.0:1.5 at 700 °C. The prepared activated carbon (SCP700) was used for the removal of two emerging contaminants, 4-bromophenol (4-BrPhOH) and 4-chloroaniline (4-ClPhNH2) that are primarily employed in the industry. Different analytical techniques were used to characterize the activated carbon. From the N2 adsorption–desorption isotherms were obtained the specific surface area of 1520 m2 g− 1 and total pore volume of 0.492 cm3 g−1. The functional groups were identified by the FTIR technique and quantified by modified Boehm titration. The results revealed the bearing of several functional groups on the SCP700 surface, which may utterly influence the removal of the emerging contaminants. The equilibrium experiments showed that the maximum uptaken capacities (Qmax) achieved at 45 °C were 488.2 (4-BrPhOH) and 552.5 mg g−1 (4-ClPhNH2). The thermodynamic parameters demonstrated that the processes of 4-BrPhOH and 4-ClPhNH2 adsorption are exothermic, spontaneous, energetically suitable, and the magnitude of ΔH° is compatible with physisorption. The mechanism of the adsorption of the emerging contaminants onto the carbon surface is dominated by microporous filling, hydrogen bonds, π-stacking interactions, and other Van der Waals interactions. The use of activated carbon for the treatment of industrial synthetic wastewater with several inorganic and organic molecules commonly found in industrial effluents showed a very high percentage of uptaking (up to 98.64%).

The Ozone Dynamics Investigation Nano-Satellite (ODIN) is a CubeSat design proposed by Chungnam National University as contribution to the CubeSat Competition 2019 sponsored by the Korean Aerospace Research Institute (KARI). The main objectives of ODIN are (1) to observe the polar ozone column density (latitude range of 60 to 80 in both hemispheres) and (2) to investigate the chemical dynamics between stratospheric ozone and ozone depleting substances (ODSs) through spectroscopy of the terrestrial atmosphere. For the operation of ODIN, a highly ecient power system designed for the specic orbit is required. We present the conceptual structural design of ODIN and an analysis of power generation in a sun synchronous orbit (SSO) using two dierent congurations of 3U solar panels (a deployed model and a non-deployed model). The deployed solar panel model generates 189.7 W through one day which consists of 14 orbit cycles, while the non-deployed solar panel model generates 152.6 W. Both models generate enough power for ODIN and the calculation suggests that the deployed solar panel model can generate slightly more power than the non-deployed solar panel model in a single orbit cycle. We eventually selected the non-deployed solar panel model for our design because of its robustness against vibration during the launch sequence and the capability of stable power generation through a whole day cycle.

Background/Aim: Endoscopic retrograde cholangiopancreatography (ERCP) training requires varying degrees of staff assistance regarding operation of the fluoroscopy machine via a foot pedal. Efficiency is important to acquire during this training due to radiation risks. In this study, we evaluate the effect of controlling endoscopy and fluoroscopy unit on duct cannulation rates (CRs) and total fluoroscopy time (FT) for fellows in training. Methods: 204 patients undergoing ERCP were randomized to one of two groups: 1) “Endoscopist Driven” group in which the endoscopist controlled the foot pedal for fluoroscopy, and 2) “Assistant Driven” group in which attending or fellow controlled the foot pedal while the other team member controlled the endoscope. Various measures including selective duct CR and total FT were recorded. Results: There was no significant difference in mean procedure duration between the two groups (32 minutes vs. 33 minutes, p=0.70). There was also no statistically significant difference in CR (83.7% vs. 77.4%, p=0.25) or FT (3.27 minutes vs. 3.54 minutes, p=0.48). Conclusions: ERCP is a technically challenging procedure which requires extensive supervision. This study demonstrates that CR and FT are not affected by who controls the fluoroscopy.

In order to improve the thermal shock and ablation resistance of high thermal conductivity carbon/carbon composites, carbon nanotubes (CNTs) were introduced by electrophoretic deposition. After modification, the flexural strength of the composites increases by 53.0% due to the greatly strengthened interfaces. During thermal shock between 1100 °C and room temperature for 30 times, the strength continues to increase, attributed to the weakened interfaces in favor of fiber and CNT pull-out. By introducing CNTs at interfaces, thermal conductivity of the composites along the fiber axial direction decreases and that along the fiber radial direction increases. As the thermal shock process prolongs, since the carbon structure integrity of CNT and matrix in the modified composites is improved, the conductivity increases whatever the orientation is, until the thermal stress causes too many defects. As for the anti-ablation performance, the mass ablation rates of the CNT-modified composites with fibers parallel to and vertical to the flame decrease by 69.6% and 43.9% respectively, and the difference in the mass ablation rate related with fiber orientations becomes much less. Such performance improvement could be ascribed to the reduced oxidative damage and the enhanced interfaces.

To meet the increased performance and cost requirements of commercial supercapacitor, a N and O self-doped hierarchical porous carbon is fabricated via a green and simple self-activation route utilizing leaves of wild hollyhock as raw materials. Comparing to commercial activated carbon, the reported material exhibits some marked merits, such as simple and green fabrication process, low cost, and superior capacitance performance. The specific surface area of the obtained N and O codoped hierarchical porous carbon arrives 954 m2 g−1, and the content of the self-doped nitrogen and oxygen reaches 2.64 at.% and 7.38 at.%, respectively. The specific capacitance of the obtained material reaches 226 F g− 1 while the specific capacitance of the symmetric supercapacitor arrives 47.3 F g− 1. Meanwhile, more than 90.3% of initial specific capacitance is kept under a current density of 20 A g− 1, and no arresting degradation is observed for capacitance after 5000 times cycle, perfectly demonstrating the excellent cycle and rate capability of the obtained material. The obtained N and O co-doped hierarchical porous carbon are expected to be an ideal substitution for commercial activated carbon.

The structural transformationss of oriented poly(vinyl alcohol) (PVA) fibers impregnated with potassium bisulfate (PBS) were studied in detail on the way from PVA precursor fibers till carbonized at a temperature of 1000 °C fibers. It has been shown that the impregnation of PVA fibers with a sulfur-containing compound (PBS) is an efficient technique to decrease the thermoplasticity of PVA fibers during heat treatment at high temperatures in air and argon and contributes to a high yield of coke residue after heat treatment up to 1000 °C. TMA, TGA, DSC, mass spectrometry, FTIR, Raman spectroscopy, SEM, WAXS and SAXS were used to study the structural transformations of oriented PVA fibers impregnated with PBS at the stages of their preliminary thermal stabilization (215 °C), thermal stabilization (215–400 °C) and carbonization (400–1000 °C). A reaction scheme has been proposed that fully describes carbonization chemistry in the entire studied temperature range. The processing temperature of 215 °C was found to be optimal for preliminary thermal stabilization of PVA fibers impregnated with PBS. The heat treatment in an inert medium can be recommended as the optimal for thermal stabilization of fibers impregnated with PBS. The characteristics of the carbonized PVA fibers, such as strength, modulus and electrical conductivity, were close to the characteristics of commercial cellulose-based carbon fibers yarns.

Nickel nanopowders are obtained by the spark discharge method, which is based on the evaporation of the electrode surface under the action of the discharge current, followed by vapor condensation and the formation of nanoparticles. Nickel electrodes with a purity of 99.99% are used to synthesize the nickel nanoparticles in the setup. Nitrogen is used as the carrier gas with a purity of 99.998%. XRD, TEM, and EDX analyses of the nanopowders are performed. Moreover, HRTEM images with measured interplanar spacings are obtained. In the nickel nanopowder samples, a phase of approximately 90 wt% with an expanded crystal lattice of 6.5% on average is found. The results indicate an unusual process of nickel nanoparticle formation when the spark discharge method is employed.

Gangliosides are glycolipids in which oligosaccharide is combined with sialic acids. Our previous studies have suggested an interplay between ganglioside GD1a/GT1b and meiotic maturation capacity in porcine oocyte maturation. Furthermore, ganglioside GD1a and GT1b are known for its antioxidant activity, but it is still unclear whether possible antioxidant role of GD1a and GT1b is involved in porcine embryos development competence during in vitro culture (IVC). Here, the effects of ganglioside GD1a and GT1b on the embryonic developmental competence during in vitro culture of porcine were investigated. The effects of ganglioside GD1a and GT1b on the expression of ST3GAL2 were confirmed during embryos development (2-cell, 4-cell, 8-cell and blastocyst) using immunofluorescent staining (IF). As a result, the fluorescent expression of ST3GAl2 was higher in embryos at 4-8 cells stage than blastocysts. Blastocyst development rate significantly increased in only 0.1 μM GD1a and GT1b treated groups compared with control group. To investigate the cellular apoptosis, we analyzed TUNEL assay. In case of only 0.1 μM GD1a and GT1b treated groups, the total number of cells in blastocyst compared with control group, but there was no significant difference in the rate of apoptotic cells. We identified the intracellular ROS levels using DCF-DA staining. According to the result, ROS production significantly decreased in blastocysts derived from the 0.1 μM GD1a and GT1b treated groups. These results suggest that ganglioside GD1a and GT1b improve the developmental competence of porcine embryos via reduction of intracellular ROS during preimplantation stage.

Cytochrome P450 1A2 (CYP1A2) is a member of the cytochrome P450 superfamily enzymes in mammals and plays a major role in metabolizing endogenous hormones in the liver. In recent days, CYP1A2 expression has been found in not only the liver but also other tissues including the pancreas and lung. However, little information is available regarding the expression of CYP1A2 in the ovary, in spite of the facts that the ovarian follicle growth and atresia are tightly associated with controls of endocrine hormonal networks. Therefore, the expression of CYP1A2 in the ovaries of prepubertal and pubertal rats was investigated to assess its expression pattern and puberty-related alteration. It was demonstrated that the expression level of CYP1A2 was significantly (p < 0.01) higher in the pubertal ovaries than prepubertal counterparts. At the ovarian follicle level in both groups, whereas CYP1A2 expression was less detectable in the primordial, primary and secondary follicles, the strongly positive expression of CYP1A2 was localized in the granulosa cell layers in the antral and pre-ovulatory follicles. However, the ratio of CYP1A2-positive ovarian follicle was significantly (p < 0.01) higher in the ovary of pubertal group (73.1 ± 3.1%) than prepubertal one (41.0 ± 10.5%). During the Immunofluorescence, expression of CYP1A2 was mainly localized in Fas-positive follicles, indicating the atretic follicles. In conclusion, these results suggested that CYP1A2 expression was mainly localized at the atretic follicular cells and affected by the onset of puberty. Further study is still necessary but we hypothesize that CYP1A2 expresses in the atretic follicles to metabolize residue of the reproductive hormones. These findings may have important implications for the fields of reproductive biology of animals.

The nutritional value and yield of mushrooms depend on the substrate on which it is grown. This study sought to biofortify Pleurotus floridanus with calcium supplements and assess its effect on the yield and calcium levels. The experiment was set up in a 2 × 5 factorial and replicated thrice in a completely randomized design. Two calcium supplements, OML and OMW, were added to two growth media. The examination of total dry weight yield showed that calcium supplements OML and OMW in the sawdust medium containing wheatbran in the ratio 1:10 had a mean value of 4.37 g, which was significantly higher (P < 0.05) than that in the control (1.29 g). However, in the sawdust-only medium, there was no significant difference (p > 0.05) in the application of treatments. No significant difference (p > 0.05) was observed between the calcium types in both growth media. The mineral analysis showed that calcium levels were increased in harvested mushrooms with the addition of calcium OML and OMW to the growth media.

We report the discovery of a giant exoplanet in the microlensing event OGLE-2017-BLG-1049, with a planet―host star mass ratio of q = 9.53 ± 0.39 × 10-3 and a caustic crossing feature in Korea Microlensing Telescope Network (KMTNet) observations. The caustic crossing feature yields an angular Einstein radius of θE = 0.52 ± 0.11 mas. However, the microlens parallax is not measured because the time scale of the event, tE ≃ 29 days, is too short. Thus, we perform a Bayesian analysis to estimate physical quantities of the lens system. We find that the lens system has a star with mass Mh = 0.55+0.36 -0.29 M⊙ hosting a giant planet with Mp = 5.53+3.62 -2.87 MJup, at a distance of DL = 5.67+1.11 -1.52 kpc. The projected star{planet separation is aㅗ = 3.92+1.10 -1.32 au. This means that the planet is located beyond the snow line of the host. The relative lens{source proper motion is μrel ~ 7 mas yr-1, thus the lens and source will be separated from each other within 10 years. After this, it will be possible to measure the flux of the host star with 30 meter class telescopes and to determine its mass.

The effects of supplementing ESP-FM (Erythrobactor sp.), freshwater Chlorella (Chlorella sp.), and baker’s yeast (Saccharomyces cerevisiae) on the nutritional value and mass production of Moina macrocopa, which is used as a live feed for fish fry production, was investigated. Consequently, the effects of feeding the enriched M. macrocopa to the nutritional composition of larval rockfish (Sebastes schlegel) and carp (Cyprinus carpio) was also investigated. Maximum density of M. macrocopa was reached within 15-21 days after inoculation (0.5 to 22 individual/mL), at various temperatures, and either decreased or remained almost constantly thereafter. Protein content and amino acids composition of M. macrocopa were found to be influenced by their respective diets while lipid and ash contents did not considerably change. M. macrocopa fed with baker’s yeast were low in n-3 HUFA content, and those fed on the freshwater chlorella were high in the 18:2n-6 and 18:3n-3 HUFA content, and in cultures treated with ESP-FM were high content in n-3 HUFA. The utilization of M. macrocopa as a substitute fish feed for carp and rockfish showed the enrichment nutritional content.

This essay analyzes the impact of COVID-19 in higher education based on national policies implemented during the current outbreak. Additionally, it enlists and discusses the proposed strategies developed to support higher education in a post-pandemic scenario based on educational and political perspectives.

이전의 스트레스 및 대처 문헌은 효과적인 스트레스 대처 전략이 개인의 복지에 대한 스트레스의 부정적인 영향을 감소시킬 뿐만 아니라 대처가 조직에도 도움이 될 수 있다고 제안한다. 본 연구에서는 노력-보상 불균형이 직원의 잡 크래프팅에 어떠한 영향을 미치는지 알아보고 이 관계에서 직원의 지각이 고용가능성과 조직몰입이 조절역할을 하는지 알아보고자 하였다. 또한, 노력-보상 불균형과 반생산적 과업행동 간 관계를 잡 크래프팅이 매개하는지 알아보고였다. 이를 위하여 본 논문에서는 한국에 종사하는 203명의 직원들을 대상으로 설문조사를 실시하였으며 회귀분석법으로 자료를 분석하였는데, 그 결과는 다음과 같다. 첫째, 노력-보상 불균형이 높을수록 잡 크래프팅이 높아지는 것으로 나타났다. 특히, 노력-보상 불균형과 구조적 직무자원을 증가시키는 행동, 사회적 직무자원을 증가시키는 행동, 그리고 도전적인 직무요구를 증가시키는 행동에 정 (+)의 관계가 있는 것으로 밝혀졌다. 그런데, 노력-보상 불균형과 방해되는 직무요구를 감소시키는 행동에 관계가 없는 것으로 밝혀졌다. 또한 과도위임과 사회적 직무자원을 증가시키는 행동, 도전적인 직무요구를 증가시키는 행동에 정 (+)의 관계가 있는 것으로 밝혀졌다. 둘째, 노력-보상 불균형과 잡 크래프팅 간의 정적 관계는 지각이 고용가능성이 낮을 때보다 높을 때 더 강하게 나타났다. 셋째, 노력-보상 불균형과 잡 크래프팅 간의 정적 관계는 조직몰입이 낮을 때보다 높을 때 더 강하게 나타났다. 넷째, 잡 크래프팅은 노력-보상 불균형과 반생산적 과업행동 간의 관계에서 매개역할을 하는 것으로 나타났다. 추가적으로 해당 연구를 통해 얻어진 결과들을 토대로 연구의 의의 및 한계 점, 향후 연구를 위한 제언 등을 통합적으로 논의하였다.