Background: Because oxidative stress can induce decreased quality of caprine semen during the storage, there has been limitation for the use of stored semen in the assisted reproductive technologies. The present study, therefore, assesses the potential of Annona muricata (A. muricata ) to reduce semen storage associateddamages. Methods: Semen was collected by electro-ejaculation from ten bucks, and extended with Tris-egg yolk (TEY) supplemented with A. muricata leaf aqueous extract (SAE) at 20 (SAE20), 40 (SAE40), and 80 (SAE80) μg/mL. Sperm variables including motility, motion characteristics, viability, membrane functionality, and DNA integrity were assessed at different storage periods (6, 24, 48, and 72 hr). In addition, oxidative stress indicators in the extender supplemted with SAE were also assessed for each group. Results: By adding SAE at 80 μg/mL in TEY, the storage of goat buck semen was improved, resulting in reduced loss of sperm motility, viability, DNA fragmentation, and membrane integrity during chilled storage at 4℃ for up to 72 hr. In addition, enrichment of TEY extender with SAE significantly (p < 0.05) reduced malondialdehyde, an indicator of oxidative stress, compared to the negative control. Conclusions: Supplementation of SAE in TEY extender can reduce buck spermatozoa liquid storage associated damages due to oxidative stress.
Today, the principles of green chemistry are being fundamentally applied in the chemical industry, such as the nitrobenzene industry, which is an essential intermediate for various commercial products. Research on the application of response surface methodology (RSM) to optimize nitrobenzene synthesis was conducted using a sulfated silica (SO4/SiO2) catalyst and batch microwave reactor. The nitrobenzene synthesis process was carried out according to RSM using a central composite design (CCD) design for three independent variables, consisting of sulfuric acid concentration on the silica (%), stirring time (min), and reaction temperature (°C), and the response variable of nitrobenzene yield (%). The results showed that a three-factorial design using the response surface method could determine the optimum conditions for obtaining nitrobenzene products in a batch microwave reactor. The optimum condition for a nitrobenzene yield of 63.38 % can be obtained at a sulfuric acid concentration on the silica of 91.20 %, stirring time of 140.45 min, and reaction temperature of 58.14 °C. From the 20 experiments conducted, the SO4/SiO2 catalyst showed a selectivity of 100 %, which means that this solid acid catalyst can potentially work well in converting benzene to nitrobenzene.
The Balloon-borne Investigation of Temperature and Speed of Electrons in the corona (BITSE) mission, performed by KASI and NASA, used a high-altitude scientific balloon. The purpose of BITSE was to investigate the scientific feasibility of electron temperature and velocity measurements in the solar corona using wavelength-dependent polarization brightness differences. KASI was responsible for developing the command and data handling (C&DH) system, including the main electronics unit and flight software (FSW). Here, we introduce the development of C&DH system of BITSE and describe the ground integration and test and flight operations. The main electronics unit was built using an industrial-grade modular system in customized enclosures that withstood the operating environment. The FSW was developed using the core Flight System (cFS), an open-source software framework developed by NASA and used in several successful space missions. BITSE was launched at Fort Sumner, New Mexico, USA, on September 18, 2019. It observed the solar corona for approximately 4 hours at an altitude of approximately 40 km and collected 16,000 solar corona images. This study could provide guidelines for developing the C&DH system for future balloon missions.
Helicobacter pylori are known as a causative agent of gastritis, gastric duodenum and peptic ulcer, and gastric cancer, and multiple drug use is associated with various side effects in patients. The discovery of antibacterial substances against H. pylori from Korean resource plants is an important substitute for antibiotics. 52 species of Korean resource plants were collected and extracted with 50% ethanol, and antibacterial activity against H. pylori was measured using the disk diffusion method. The toxicity of plant extracts to human gastric adenocarcinoma(AGS) cells was measured by MTT assay, and the level of IL-8 secreted when gastric epithelial cells were inoculated with H. pylori was measured. As a result of measuring the antibacterial activity of H. pylori, antibacterial activity was confirmed in 38 plant extracts. The plant species with the strongest antibacterial activity were Chrysanthemum indicum, Rheum rhabarbarum, Patrinia scabiosaefolia and Petasites japonicus. C. indicum was not cytotoxic to H. pyroli-infected AGS cells and showed anti-inflammatory effects. This study's results can be used to develop healthy, functional foods and medical materials.
Integration of noble metals on graphene is renowned for their catalytic and antioxidant prowess. However, utilization of toxic chemicals in the synthesis creates environmental pollution and poisonous nature of chemically synthesized materials. To address this, an economical and eco-friendly method for synthesizing graphene-gold (BRG-Au) nanocomposite by anchoring gold nanoparticles (Au NPs) onto reduced graphene oxide sheets using betel leaf extract as a reducing and stabilizing agent is presented. Comprehensive structural characterizations through UV–Visible, Raman, FT-IR, and XRD analyses confirm the successful formation of the BRG-Au nanocomposite. Morphological assessments utilizing FE-SEM and TEM techniques revealed the presence of transparent, twinkling graphene sheets embellished with 20 to 60 nm of Au NPs in various shapes, including spherical, triangular, pentagonal, circular, and trapezoids. The catalytic and antioxidant activities of the BRG-Au nanocomposite were thoroughly evaluated. In catalytic trials, the nanocomposite exhibited remarkable efficiency in the reduction of 4-nitrophenol to 4-aminophenol, accomplishing this transformation within a mere 30 min during the initial cycle and maintaining stable catalytic performance over three consecutive cycles. Additionally, antioxidant analyses employing Total Antioxidant Activity and 2,2-diphenyl-1-picrylhydrazyl methods demonstrated that BRG-Au nanocomposite possessed equal or superior antioxidant activity than the ascorbic acid standard. This research thus underscores the promising potential of environmentally benign synthesis method for graphene-gold nanocomposite with enhanced catalytic and antioxidant properties.
To fabricate intermetallic nanoparticles with high oxygen reduction reaction activity, a high-temperature heat treatment of 700 to 1,000 °C is required. This heat treatment provides energy sufficient to induce an atomic rearrangement inside the alloy nanoparticles, increasing the mobility of particles, making them structurally unstable and causing a sintering phenomenon where they agglomerate together naturally. These problems cannot be avoided using a typical heat treatment process that only controls the gas atmosphere and temperature. In this study, as a strategy to overcome the limitations of the existing heat treatment process for the fabrication of intermetallic nanoparticles, we propose an interesting approach, to design a catalyst material structure for heat treatment rather than the process itself. In particular, we introduce a technology that first creates an intermetallic compound structure through a primary high-temperature heat treatment using random alloy particles coated with a carbon shell, and then establishes catalytic active sites by etching the carbon shell using a secondary heat treatment process. By using a carbon shell as a template, nanoparticles with an intermetallic structure can be kept very small while effectively controlling the catalytically active area, thereby creating an optimal alloy catalyst structure for fuel cells.
The genus Hypsopygia was established by Hübner, 1825, with type species Phalaena costalis Fabricius, 1775. Hypsopygia is characterized by the elongated uncus and valva, and pointed saccus in the male genitalia. It consists of 105 described species (Nuss et al., 2003–2024) in the world, and 11 species have been recorded in Korea (Kim & Paek, 2020; Shin et al., 2023). In this study, we reported one newly recorded species in Korea. Illustrations of adults provided, with information of host plants of all examined species.
The genus Olethreutes, established by Hübner in 1822, is based on the type species Phalaena arcuella Clerk, 1759. Olethreutes is one of the largest group within the family Tortricidae, with more than 130 species worldwide. As of now, about 31 species of the genus Olethreutes have been reported in the Korean peninsula. The proposes of this study is to describe one new species, with three similar species form Korea.
Insect cuticular extracellular matrices (ECM) including the eggshell and exoskeleton play vital roles in protecting them from natural environmental stresses. However, these chitinous ECMs must be degraded at least in part during embryonic and post-embyonic molting periods to accommodate continuous growth all the way to the adult stage. In this study we investigated the functions of groups I and II chitinases, TcCHT5 and TcCHT10, in turnover of the eggshell and cuticle in Tribolium castaneum. RNAi and TEM analyses revealed that TcCHT10 is required for digestion of chitin in the serosal cuticle for embryo hatching as well as in the old cuticle during post-embryonic molts including larval-pupal and pupal-adult metamorphosis. However, although TcCHT5 is apparently involved in these vital physiological events, TcCHT10 could substitute for TcCHT5 except during the pupal-adult molting when both enzymes are indispensable to degrade chitin in the old pupal cuticle.
겨울과 같은 환경에서 곤충은 생존과 번성을 위해 생리학적, 생화학적 및 행동적 메커니즘을 이용하고 있다. 대부분의 곤충은 생리학적 적응가운데 급속내한성(Rapid cold hardiness, RCH) 유기를 통해 기온이 급격히 낮아 지는 외부 환경에 대해 빠르게 적응하고 저온조건에서 생존율을 높인다. 열대거세미나방의 경우 행동적 메커니 즘을 통해 따뜻한 곳을 찾아 장거리 비행을 하며, 생존에 유리한 환경으로 이동한다. 본 연구에서는 열대거세미나 방의 생리적 월동능력과 RCH 능력에 관해 조사하였다. 그 결과, RCH에 의해 혈중 글리세롤의 농도가 증가와 체내빙결점이 하강하는 것을 확인할 수 있었다. 또한, RCH(-10℃, 1h)에 노출된 2령 유충기를 대상으로 4령과 5령 유충기에 단기저온(5℃, 30min)에 노출 시 글리세롤 생합성에 관여하는 유전자(glycerol kinase 1, 2)의 발현이 RCH에 노출되지 않은 대조구와 비교하여 빠르게 발현되었다. 이는, 열대거세미나방의 유전자 수준에서 저온에 대한 단기기억이 존재하는 것을 제시한다.