• Korean Chemical Engineering Research
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• v.59 no.2
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• pp.153-158
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• 2021

In this study, we will determined the total phenolic content (TPC) and the antioxidant activity of the methanolic extract (ME) of date palm (Phoenix dactylifera. L) fruits (DPF) of four native cultivars from Algeria: Ghars (Gh), Chtaya (Cht), DeglaBeïda (DB) and Tinissine (Tns). The TPC of ME of DPF was measured by using Folin-Ciocalteu. Thereafter, the antioxidant capacity of various extracts was determined using DPPH test, reducing power and superoxide anion test. These results showed that dates had strongly scavenging activity on DPPH. The value of IC50 for DPPH radical test was 0.077 mg/ml in Cht. Also, Cht cultivar showed the best-reducing power, which was significantly higher than the other varieties. The less IC50 value in cyclic voltammetry method (CV), which meets the highest effective antioxidant, was 0.006 mg/ml in methanolic extract of Cht.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.375.1-375.1
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• 2016

Polymerase chain reaction (PCR) has revolutionized genetics and become one of the most popular techniques in modern biological and medical sciences. It can be used not only as an in vitro DNA amplification method but also used in many bioassay applications. The PCR can be used to exponentially produce a large number of DNA copies from a small quantity of DNA molecules in a few hours. However, as unwanted DNA fragments are also often manufactured, the amplification efficiency of PCR is decreased. To overcome this limitation, several nanomaterials have been employed to increase the specificity of the PCR reaction. Recently, graphene has attracted a great interest for its excellent electron transfer, thermal and biocompatibility. Especially, gold nanoparticle-coated graphene oxide (GO/AuNPs) led to enhance electron and thermal transfer rate and low-charge transfer resistance. Therefore, we report the development of a demonstration for the PCR efficiency using a large-scale production of the GO and combination of gold nanoparticles. Because a thermal conductivity is an important factor for improving the PCR efficiency in different DNA polymerases and different size samples. When PCR use GO/AuNPs, the result of transmission electron microscopy and real-time quantitative PCR (qPCR) showed an enhanced PCR efficiency. We have demonstrated that GO/AuNPs would be simply outperformed for enhancing the specificity and efficiency of DNA amplification procedure.

• YAKHAK HOEJI
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• v.16 no.3
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• pp.113-120
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• 1972

The last decade of this centry is now the accepted birth date of that sub-discipline of pharmacy that is now called 'biopharmceutics'. Wagner defines biopharmaceutics 'as the study of the influence of fomulation on the therapeutic activity of a drug product.' More specifically, he states that biopharmaceutics encompasses the study of the relationship between the nature and intensity of the biological effects observed in animals or man and the following factors: 1. The nature of the form of the drug (ester, salt, complex, etc). 2. The physical state, particle size, and surface area. 3. Presence or absence of adjuvants with the drug. 4. The type of dosage form in which the drug is administered. 5. The pharmaceutical process (es) used to make the dosage form. The philosophy inherent in this definition has revolutionized our thinking with respect to product development, quality control, and to the practice of pharmacy itself. Althoughthe the emphasis herein will be on quality control, the interrelationship between this and the other areas of pharmacy will be evident. The principles of quality control dictate that a wide variety of techniques be used to evaluate the quality of a dosage form. Since quality must be built into a dosage form, the pharmaceutical scientist begins the process at the research stage, continues it during the production stage, and ends it by applying the tests and procedures established by parmacopeial commissions. These stages are usually separate and distinct and, because of this, product quality has become synonymous with compliance with pharmacopeial specifications.

• Journal of the Korean Chemical Society
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• v.57 no.4
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• pp.439-446
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• 2013

Chitosan (CS) and hydroxypropylmethyl cellulose (HPMC) blend microspheres were prepared by water-in-oil emulsion technique and were loaded with an anti-cancer drug 5-fluorouracil (5-FU). CS-HPMC microspheres were characterized by Fourier transform infrared spectroscopy to confirm the cross-linking reaction. Scanning electron microscopy (SEM) was also used to assess the surface morphology of particles prepared. The quantity of release of 5-FU from the microspheres have been studied in terms of blend composition and amount of cross-linking agent. Differential scanning calorimetry and X-ray diffraction techniques indicated a uniform distribution of 5-FU particles in microspheres, whereas SEM suggested the spherical structure of the microspheres with slight rough surface. The in vitro drug release indicated that the particle size and release kinetics depend upon blend composition, amount of cross-linking agent used and amount of 5-FU present in the microspheres.

• Journal of Embryo Transfer
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• v.15 no.2
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• pp.175-180
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• 2000

The possible use of micromanipulative biopsy and PCR of the biopsied embryonic cells was tested to produce sexed bovine embryos in practical terms. By micromanipulation and PCR techniques, higher survival rate and accurate sexing of demi-embryos were btained. Bovine oocytes matured and fertilized in vitro were co-cultured with bovine oviductal epithelial cell (BOEC) monolayer in USU-6 medium supplemented with 15% FBS, and the embryos of 37% (327/885) were developed to blastocysts. Among 111 blastocysts produced by invitro, only 7 (6.3%) embryos were found unable to determine their sex, probably due to the loss of cells, since no PCR product was found from those cells. All the remaining 104 (93.7%) demi-embryos survived micromanipulation and demonstrated male-specific product or bovine-specific product alone suggesting that correct sexing of the sample. Forty-three point one percent(25/58) of manipulated and cryopreserved demi-embryos after thawing were survived. Final verification of the sexed embryos is necessary to make sure the same sex in fetus and newborn calf upon embryo transfer. The established sexing method on a large number of bovine embryos from previous and this study suggests that this a could be used practically in the field.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.11a
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• pp.195-195
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• 2003

Combustion generated fine particles, defined as those with aerodynamic diameters less than 2.5 m, have come under increased regulatory scrutiny because of suspected links to adverse human health effects. Transition metals are of particular interest due to the results of a number of studies that have shown cardiopulmonary damage associated with exposure to these elements and their presence in coal, residual fuel oils, sewage sludge, and other combusted fuels and wastes. This lecture will review results from multi-di sciplinary studies being conducted at EPA and elsewhere examining the physical, chemical, and toxicological characteristics of combustion generated particles. The research describes how collaborative work between combustion engineers and health scientists can provide insight on how combustion processes affect particle properties and subsequent health effects as measured by a combination of in-vitro and in-vivo studies using a variety of animal models. The focus of this lecture is on the interdisciplinary approach required to address the problem. Difficulties are discussed. Engineering aspects involved in this approach are described in detail. Physical and chemical characterizations are performed using a variety of analytical approaches including new techniques of x-ray absorption fine structure (XAFS) spectroscopy and x-ray absorption near-edge structure (XANES) deconvolution of these spectra to gather metal speciation information.

• Clinical and Experimental Reproductive Medicine
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• v.48 no.2
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• pp.184-187
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• 2021

Radical trachelectomy is a fertility-preserving alternative to radical hysterectomy in carefully selected young women with early-stage cervical cancer. However, in cases with subsequent severe cervical stenosis, assisted reproductive techniques can be difficult. This is a case report of a 34-year-old patient who underwent robot-assisted radical trachelectomy and cerclage for early-stage (IB2) adenosquamous carcinoma. Three months after surgery, the patient underwent ovarian stimulation using a gonadotropin-releasing hormone antagonist protocol. As it was impossible to perform transcervical embryo transfer due to the almost complete absence of the cervical opening, transmyometrial embryo transfer under ultrasound guidance was performed. This resulted in a successful singleton pregnancy. This is the first case of successful pregnancy conceived by in vitro fertilization with transmyometrial embryo transfer in a patient who had previously undergone robot-assisted radical trachelectomy.

• Development and Reproduction
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• v.21 no.3
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• pp.229-235
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• 2017

In the field of reproductive medicine, assessment of sperm motility is a key factor for achieving successful artificial insemination, in vitro fertilization, or intracellular sperm injection. In this study, the motility of boar sperms was estimated using real-time imaging via confocal microscopy. To confirm this confocal imaging method, flagellar beats and whiplash-like movement angles were compared between fresh and low-temperature-preserved ($17^{\circ}C$ for 24 h) porcine sperms. Low-temperature preservation reduced the number of flagellar beats from $11.0{\pm}2.3beats/s$ (fresh sperm) to $5.7{\pm}1.8beats/s$ and increased the flagellar bending angle from $19.8^{\circ}{\pm}13.8^{\circ}$ (fresh) to $30.6^{\circ}{\pm}15.6^{\circ}$. These data suggest that sperm activity can be assessed using confocal microscopy. The observed motility patterns could be used to develop a sperm evaluation index and automated confocal microscopic sperm motility analysis techniques.

• Journal of Plant Biotechnology
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• v.8 no.1
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• pp.43-50
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• 2006

The goal of this research was to develop an efficient cryopreservation protocol for germplasms of yam (Diosorea batatas), that were cultivated in Korea. Comparative studies with four other cryogenic techniques and subsequent experiments for shoot regrowth were conducted. in vitro-grown shoot-apices of the D. batatas were successfully cryopreserved by encapsulation-dehydration. The maximum survival of shoot-apices could be achieved when the precultured (with 0.3 M of sucrose for one day) and encapsulated (with a 3%(w/v) Na-alginate solution) apices were dehydrated for $3.5{\sim}4\;h$ prior to direct immersion in LN (liquid nitrogen). The frequency of regrowth rate of cryopreserved apices was not decreased during 3-month storage period. The thawing method markedly affected survival of the cryopreserved apices, and thawing at $40^{\circ}C$ for 3 min produced the best results. When cryopreserved apices were post-cultured on the post-culture medium (MS), supplemented with $0.2mgl^{-1}$ of BA ($N_6$-benzyladenine) and $0.2mgl^{-1}$ of kinetin, they showed direct shooting without callusing.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2017.05a
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• pp.3-23
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• 2017

The achievement of tissue engineering can be highly depending on the capability to generate complicated, cell seeded three dimensional (3D) micro/nano-structures. So, various fabrication techniques that can be used to precisely design the architecture and topography of scaffolding materials will signify a key aspect of multi-functional tissue engineering. Previous methods for obtaining scaffolds based on top-down are often not satisfactory to produce complex micro/nano-structures due to the lack of control on scaffold architecture, porosity, and cellular interactions. However, a bioprinting method can be used to design sophisticated 3D tissue scaffolds that can be engineered to mimic the tissue architecture using computer aided approach. Also, in recent, the method has been modified and optimized to fabricate scaffolds using various natural biopolymers (collagen, alginate, and chitosan etc.). Variation of the topological structure and polymer concentration allowed tailoring the physical and biological properties of the scaffolds. In this presentation, the 3D bioprinting supplemented with a newly designed plasma treatment for attaining highly bioactive and functional scaffolds for tissue engineering applications will be introduced. Moreover, various in vivo and in vitro results will show that the fabricated scaffolds can carry out their structural and biological functionality.