• Title/Summary/Keyword: NMPs

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Potential degradation of methylene blue (MB) by nano-metallic particles: A kinetic study and possible mechanism of MB degradation

  • Singh, Jiwan;Chang, Yoon-Young;Koduru, Janardhan Reddy;Yang, Jae-Kyu
    • Environmental Engineering Research
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    • v.23 no.1
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    • pp.1-9
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    • 2018
  • The degradation of methylene blue (MB) in an aqueous solution by nano-metallic particles (NMPs) was studied to evaluate the possibility of applying NMPs to remove MB from the wastewater. Scanning electron microscopy (SEM), Fourier-transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS) were used to characterize the synthesized NMPs before and after the reaction. The effects of the NMP dosage, the initial pH, the initial concentration of MB and the amount of $H_2O_2$ on the MB degradation outcomes were studied. The highest removal rate of MB was achieved to be 100% with an initial MB concentration of 5 mg/L, followed by 99.6% with an initial concentration of 10 mg/L under the following treatment conditions: dose of NMP of 0.15 g/L, concentration of $H_2O_2-100mM$ and a temperature of $25^{\circ}C$. The SEM analysis revealed that the nano particles were not spherical in shape. FTIR spectra shows occurrence of metal oxides on the surfaces of the NMPs. The XPS analyses results represent that Fe, Zn, N, Ca, C and O were occurred on the surfaces of the NMPs. The degradation of MB was suitable for the pseudo-first-order kinetics.

Embryonal Neuromesodermal Progenitors for Caudal Central Nervous System and Tissue Development

  • Shaker, Mohammed R.;Lee, Ju-Hyun;Sun, Woong
    • Journal of Korean Neurosurgical Society
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    • v.64 no.3
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    • pp.359-366
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    • 2021
  • Neuromesodermal progenitors (NMPs) constitute a bipotent cell population that generates a wide variety of trunk cell and tissue types during embryonic development. Derivatives of NMPs include both mesodermal lineage cells such as muscles and vertebral bones, and neural lineage cells such as neural crests and central nervous system neurons. Such diverse lineage potential combined with a limited capacity for self-renewal, which persists during axial elongation, demonstrates that NMPs are a major source of trunk tissues. This review describes the identification and characterization of NMPs across multiple species. We also discuss key cellular and molecular steps for generating neural and mesodermal cells for building up the elongating trunk tissue.

Rapid Fenton-like degradation of methyl orange by ultrasonically dispersed nano-metallic particles

  • Singh, Jiwan;Chang, Yoon-Young;Koduru, Janardhan Reddy;Yang, Jae-Kyu;Singh, Devendra Pratap
    • Environmental Engineering Research
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    • v.22 no.3
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    • pp.245-254
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    • 2017
  • This study investigates methyl orange (MO) degradation by an ultrasonically dispersed nano-metallic particle (NMP) assisted advanced Fenton process. The NMPs were synthesized from the leachate of automobile-shredder residue. X-ray photoelectron spectroscopy and Fourier-transform infrared spectroscopy were performed for the prepared NMPs. Various parameters, such as the effects of the NMP dosage, the pH value of the solution, the initial concentration of MO, and the amount of $H_2O_2$ on the degradation efficiency of MO were studied. The MO degradation efficiency could be increased by approximately 100% by increasing the dosages of the NMPs and $H_2O_2$ to certain limits, after which in both cases the degradation efficiency was reduced when an excess amount was added. The MO degradation efficiency was found to be 100% at pH 2.0 and 2.5 with the 10 mg/L of initial concentration of the MO. The degradation of MO by ultrasonically dispersed NMPs was appropriate with the pseudo-first-order kinetics.

Design and Implementation of Network Management System Based on Mobile Sink Networks (모바일 싱크 네트워크를 적용한 망 관리 시스템의 설계 및 구현)

  • Kim, Dong-Ok
    • Journal of The Institute of Information and Telecommunication Facilities Engineering
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    • v.8 no.4
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    • pp.216-222
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    • 2009
  • This paper proposes an integrated mobile sink networks management system which can monitor and control various kinds of wireless lan access points, located in many different areas divided by their managing groups, from multi-vendors, and their operations in networks. The proposed system has the center-local interoperability structure cooperating with local-center servers which can perform the same operations as the central servers for wireless lan access points from multi-vendors and wireless lan centric management features. For this purpose, we propose a new way of data design, messaging policy, and hierarchical system structure such that we can achieve stable and consistent management methods for various wireless access points on distributed networks.

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DNA·RNA Heteroduplex Containing 8-Oxo-7,8-dihydroguanosine: Base Pairing, Structures, and Thermodynamic Stability

  • Kim, Sang-Kook;Lee, Sung-Hwa;Kwon, Oh-Shin;Moon, Byung-Jo
    • BMB Reports
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    • v.37 no.6
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    • pp.657-662
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    • 2004
  • Oligoribonucleotides containing 8-oxo-7,8-dihydroguanosine (8-oxoG) and 8-oxo-7,8-dihydro-2'-O-methylguanosine (8-oxoG-Me) were synthesized. The base pairing properties of 8-oxoG and 8-oxoG-Me in oligoribonucleotide in cDNA synthesis by reverse transcriptases were studied. dCMP was preferentially incorporated into the site opposite 8-oxoG or 8-oxoG-Me than into other dNMPs. TMP and dCMP were inserted preferentially into sites opposite 8-oxoG or 8-oxoG by reverse transcriptases. HIV-RT did not incorporate TMP, but RAV2-RT incorporated 50% more TMP than dCMP into the site opposite 8-oxoG. In the site opposite 8-oxoG-Me TMP was substantially incorporated by HIV-RT or RAV2-RT. Thermodynamic analysis of the DNA. RNA heteroduplex containing 8-oxoG revealed that 8-oxoG and 8-oxoG-Me formed base pairs with cytidine and thymidine with similar stability. The thermodynamic parameter (${\Delta}G^{\circ}$) demonstrated that the formation of duplexes between 8-oxoG or 8-oxoG-Me and cytidine or thymidine is more thermodynamically favorable than with adenosine and guanosine. However, differences in the melting temperature and ${\Delta}G^{\circ}$'s of 8-oxoG/dC and 8-oxoG/T were much smaller than between G/dC and G/T. CD spectra showed that DNA . RNA containing 8-oxoG or 8-oxoG-Me duplexes showed similarities between the A-type RNA and B-type DNA conformations.

Design and Implementation of IP-based Network Management System Supporting WLAN Integrated Management System (IP 네트워크를 기반으로 하는 무선망 통합 관리 시스템 설계 및 구현)

  • Shin, Myung-Sik;Yang, Hae-Sool;Lee, Kee-Hee
    • Journal of the Korea Society of Computer and Information
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    • v.15 no.7
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    • pp.33-40
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    • 2010
  • The hand over between different radio access networks, especially where their coverage overlaps, suffers various complications since the different access networks provide different service characteristics. In this paper, it is about the system which can control the wireless LAN network management system and the wireless LAN access point of variety vendor which is in different areas. Successful development of mobile sink wireless LAN network management system which supports multi-vendor devices and have center-local interoperability structure. In proposed system, speed of the mobile station give about 10% improvement when the map domain size is 5 than the existing system. Through a data plane and management system of message way, it give a stability system and consistency network.

Determination of Soil Nitrogen Supplying Capacity Using Pepsin Digestibility (Pepsin 분해방법을 이용한 토양의 질소 공급력 결정)

  • Kim, Yoo-Hak;Kim, Sun-Kwan;Zhang, Yong-Sun
    • Korean Journal of Soil Science and Fertilizer
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    • v.38 no.5
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    • pp.253-258
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    • 2005
  • It is necessary to determine a nitrogen supplying capacity (NSC) of soil for sustainable agriculture. NSC has been decided by directly detecting N mineralization potential (NMP) and inorganic nitrogen or by indirectly approximating from organic matter and chemical properties of soil. NMP is best method for NSC but it takes long period. A study was conducted to find a short-term incubation method using pepsin through 1) determining NMP of 3 upland and 3 paddy soils, 2) establishing analytical condition of pepsin digestion by comparing to NMP, 3) validating with relations to N requirements for maximum yield of rice. NMPs of 6 soils were ranges from $63mg\;N\;kg^{-1}$ to $156mg\;N\;kg^{-1}$. The pepsin digestion method of soil nitrogen was established by determining amino nitrogen from digesting 5 g of soil for 30 minutes by 0.02% pepsin. This method was so highly correlated with a maximum rate of nitrogen fertilizer that it could be used for determining NSC in paddy soil.

Potential Contamination Sources on Fresh Produce Associated with Food Safety

  • Choi, Jungmin;Lee, Sang In;Rackerby, Bryna;Moppert, Ian;McGorrin, Robert;Ha, Sang-Do;Park, Si Hong
    • Journal of Food Hygiene and Safety
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    • v.34 no.1
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    • pp.1-12
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    • 2019
  • The health benefits associated with consumption of fresh produce have been clearly demonstrated and encouraged by international nutrition and health authorities. However, since fresh produce is usually minimally processed, increased consumption of fresh fruits and vegetables has also led to a simultaneous escalation of foodborne illness cases. According to the report by the World Health Organization (WHO), 1 in 10 people suffer from foodborne diseases and 420,000 die every year globally. In comparison to other processed foods, fresh produce can be easily contaminated by various routes at different points in the supply chain from farm to fork. This review is focused on the identification and characterization of possible sources of foodborne illnesses from chemical, biological, and physical hazards and the applicable methodologies to detect potential contaminants. Agro-chemicals (pesticides, fungicides and herbicides), natural toxins (mycotoxins and plant toxins), and heavy metals (mercury and cadmium) are the main sources of chemical hazards, which can be detected by several methods including chromatography and nano-techniques based on nanostructured materials such as noble metal nanoparticles (NMPs), quantum dots (QDs) and magnetic nanoparticles or nanotube. However, the diversity of chemical structures complicates the establishment of one standard method to differentiate the variety of chemical compounds. In addition, fresh fruits and vegetables contain high nutrient contents and moisture, which promote the growth of unwanted microorganisms including bacterial pathogens (Salmonella, E. coli O157: H7, Shigella, Listeria monocytogenes, and Bacillus cereus) and non-bacterial pathogens (norovirus and parasites). In order to detect specific pathogens in fresh produce, methods based on molecular biology such as PCR and immunology are commonly used. Finally, physical hazards including contamination by glass, metal, and gravel in food can cause serious injuries to customers. In order to decrease physical hazards, vision systems such as X-ray inspection have been adopted to detect physical contaminants in food, while exceptional handling skills by food production employees are required to prevent additional contamination.