• Korean Journal of Soil Science and Fertilizer
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• v.49 no.2
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• pp.168-180
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• 2016

Various researches on the effects of fertilization levels on functional metabolites in crop have been conducted. This review summarizes the previous studies on the relation between fertilization supply and accumulation of metabolites (phenolics, carotenoids, ascorbic acid and glucosinolates) which function as antioxidants in crop. The accumulation of phenolic compounds is related to the activation of phenylalanine ammonia lyase (PAL) in phenylpropanoid pathway. Most of the previous studies discuss that low nitrogen (N) supply activates PAL, thereby increasing the synthesis of phenolics. Similarly, high N supply leads to a decrease in ascorbic acid because of the shading effect derived from the accelerated vegetative growth under high N level. Unlike the phenolics and ascorbic acid, carotenoids are accumulated with increasing N supply. In this regard, the previous studies explain that N is a main element closely associated with formation of key enzyme for the synthesis of carotenoids. Glucosinolates are generally increased under decreasing N supply and increasing S supply. Although the previous studies show similar trends about the accumulation of metabolites by nutrient level, they also suggest that many other factors including crop types, cultivars, cultural environment (water, temperature, light, etc.) influence the accumulation of functional metabolites in crop.

• Journal of Embryo Transfer
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• v.25 no.2
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• pp.97-101
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• 2010

Intracytoplasmic sperm injection (ICSI) is one of the artificial fertilization methods when only a few sperm are available for insemination, and an important tool for the preservation of genetic materials of endangered animal species, especially the male is infertile. Different from other species such as mice and pigs, the conventional ICSI method which uses spiked pipette for injection (Spike-ICSI) is exhibited low success rates in cattle because the bovinesperm head membrane is hard to break during injection procedure. We chose piezo-assisted ICSI (Piezo-ICSI) for the improvement of the injection procedure including sperm head membrane rupture and efficient puncture of the plasma membrane of the oocytes. In this experiment, we compared the efficacy of the bovine ICSI embryo production between the Piezo-ICSI and Spike-ICSI. The second polar body extrusion, pronuclear formation, cleavage and blastocyst formation were evaluated after implementation of two different ICSI techniques. The Piezo-ICSI tended to show comparably higher rates of the second polar body extrusion (41.7%), the pronuclei formation (42.9%) and the two-cell cleavage (41.4%) than Spike-ICSI does (33.3%, 28.6% and 23.5%, respectively) although there is no statistic significance between two groups. In addition, the blastocysts were only obtained from the Piezo-ICSI group (10.3%). Our finding shows that the Piezo-ICSI may be used as an artificial fertilization method in cattle when in vitro fertilization is not applicable.

• Clinical and Experimental Reproductive Medicine
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• v.38 no.3
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• pp.148-152
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• 2011

Objective: Laser-assisted intracytoplasmic sperm injection (LA-ICSI), also known as micro-opening or thinning of the zona pellucida (ZP) prior to ICSI, may help to reduce mechanical damage to the oocyte during the procedure. The aim of the present study was to evaluate and analyze the efficacy of our institutional LA-ICSI program, which features laser-assisted ZP thinning prior to ICSI, in comparison with conventional ICSI (C-ICSI), performed on patients with different clinical characteristics. Methods: Patients undergoing a total of 212 ICSI cycles were randomly divided into an LA-ICSI group (106 cycles) and a conventional ICSI group (106 cycles). To reduce tissue damage, we thinned the ZP by approximately 70%, using a laser, before ICSI. Patients thus treated formed the LAICSI group. Comparisons included the morphological quality of transferred embryos, blastocyst development of the remaining embryos, and clinical pregnancy, in terms of ICSI method and patient characteristics. Results: Fertilization, development of remaining embryos, and pregnancy rate were significantly higher in the LA-ICSI group compared with the C-ICSI group. Fertilization, embryonic development, and the pregnancy rate were all improved in younger patients (<38 years of age) and in those who underwent a low number of IVF-ET attempts (<3 trials). In addition, the pregnancy rate was increased in older patients. Conclusion: LA-ICSI may be useful in improving the chance of pregnancy in all ICSI patients.

• Clinical and Experimental Reproductive Medicine
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• v.49 no.3
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• pp.210-214
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• 2022

Objective: Platelet-rich plasma (PRP) therapy has received a considerable attention as an adjunct to fertility treatments, especially in women with very low ovarian reserve and premature ovarian insufficiency. Although recent studies have demonstrated that PRP led to improvements in folliculogenesis and biomarkers of ovarian reserve, the effect of intraovarian PRP administration on embryo genetics has not been studied. Methods: We report a pilot study of patients who had preimplantation genetic testing for aneuploidy (PGT-A) before and then within 3 months following PRP administration. Twelve infertile women with at least one prior failed in vitro fertilization (IVF) cycle underwent ovarian stimulation (cycle 1) with a gentle stimulation protocol and PGT-A performed at the blastocyst stage. Following cycle 1, autologous intraovarian PRP administration was performed. Within 3 months following PRP administration, the patients underwent cycle 2 and produced blastocysts for PGT-A. The percentage of euploid embryos between both cycles was compared. Results: The mean age of all participants was 40.08±1.46 years, and their mean body mass index was 26.18±1.18 kg/m². The number of good-quality embryos formed at the blastocyst stage was similar between cycle 1 and cycle 2 (3.08±0.88 vs. 2.17±0.49, respectively; p=0.11). Among all patients in cycle 1, 3 of 37 embryos were euploid (8.11%) while in cycle 2, 11 out of 28 embryos were euploid (39.28%, p=0.002). Three clinical pregnancies were noted among this patient group. Conclusion: This novel study is the first to present an improvement in the embryo euploidy rate following intraovarian PRP application in infertile women with prior failed IVF cycles. The growth factors present in PRP may exhibit a local paracrine effect that could improve meiotic aberrations in human oocytes and thus improve euploidy rates. Whether PRP improves live birth rates and lowers miscarriage rates remains to be determined in large trials.

• Journal of Applied Biological Chemistry
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• v.65 no.1
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• pp.1-6
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• 2022

Urea is one of the most common nitrogen fertilizer, but nitrogen use efficiency by crop is low because of rapid hydrolysis of urea and loss of nitrogen in environments. Therefore, it is important to control the nitrogen release from nitrogen fertilizers. In this study, pyroligneous acid (PA) was used as a mean to inhibit urease in soil and prevent excessive nitrogen release from urea. Active ingredient in PA (AI) inhibited ammonification of urea in soil by reducing extracted ammonium nitrogen at 79.7% compared to the soil without PA. In order to evaluate the effect of PA on fertilization efficiency of urea, Chinese cabbage (Brassica campestris var. Pekinensis) was cultivated in soil treated with urea and PA both in pot and field. For PA treatment, half amount of urea was used compared to the amount of urea conventionally applied to Chinese cabbage. The PA treatment with half amount of urea resulted in similar Chinese cabbage biomass to the conventional urea application. Nitrogen concentration in Chinese cabbage was less in PA treatment indicating that Chinse cabbage effectively used nitrogen. Consequently, fertilization of urea with PA will reduce amount of fertilizer and frequency of application.

• Clinical and Experimental Reproductive Medicine
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• v.51 no.2
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• pp.158-162
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• 2024

Objective: The aim of this study was to compare the outcomes of in vitro fertilization (IVF) in patients with a poor ovarian response who used methyltestosterone, versus those using a placebo, in an infertility clinic setting. Methods: This clinical trial included 120 women who had undergone IVF with intracytoplasmic sperm injection due to poor ovarian reserve and infertility. The study took place at the Yas Infertility Center in Tehran, Iran, between January 1, 2018 and January 1, 2019. In the intervention group, 25 mg of methyltestosterone was administered daily for 2 months prior to the initiation of assisted reproductive treatment. The control group was given placebo tablets for the same duration before starting their cycle. Each group was randomly assigned 60 patients. All analyses were performed using SPSS ver. 23 (IBM Corp.). Results: The endometrial thickness in the intervention group was 7.57±1.22 mm, whereas in the control group, it was 7.11±1.02 (p=0.028). The gonadotropin number was significantly higher in the control group (64.7±13.48 vs. 57.9±9.25, p=0.001). However, there was no significant difference between the two groups in the antral follicular count. The chemical and clinical pregnancy rates in the intervention group were 18.33% and 15% respectively, compared to 8.33% and 6.67% in the control group. The rate of definitive pregnancy was marginally higher in the intervention group (13.3% vs. 3.3%, p=0.05). Conclusion: The findings of this study suggest that pretreatment with methyltestosterone significantly increases endometrium thickness and is associated with an increase in the definitive pregnancy rate.

• Korean Journal of Soil Science and Fertilizer
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• v.15 no.3
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• pp.178-187
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• 1982

This pot experiment was undertaken to find out the optimum fertilization ratios of total anions to total cations, ${\Sigma}A/{\Sigma}C$, and the optimum application rates of total macro-nutrients in various soil conditions. Soil samples were collected from uncultivated mountains and hills where grassland development was under consideration. 1. The optimum application ratios of ${\Sigma}A/{\Sigma}C$ and the optimum application rates of total macro-nutrients for the high yields of mixed grass-clover sward in various grassland soils were computed by the Hom$\acute{e}$s systematic variation techniqu.e. 2. With respect to the optimum application ratios of ${\Sigma}A/{\Sigma}C$ in fertilization in a mixed grass-clover sward, the grass yield and botanical composition were distinctly proportional to ${\Sigma}A$ wheras the regume yield and botanical composition were proportional to ${\Sigma}C$. 3. The optimum fertilization rates of total macro-nutrients for the high legume yields were depended upon ${\Sigma}A/{\Sigma}C$ ratios. These optimum rates were in proportional to ${\Sigma}C$ ratios and were inversely proportional to ${\Sigma}A$ ratios. 4. The efficiencies of ${\Sigma}A$ and ${\Sigma}C$ in relation to the grass and grass plus legume yields were highest with the low ratios of each other and the low fertilization rates of total macronutrients. The ${\Sigma}A$ effieiency in the legume yield tended to be similar to that of ${\Sigma}A$ related to the grass yield noted above except Daegu soil. The ${\Sigma}C$ efficiency, however, was proportional to the ${\Sigma}C$ ratio, although that was varied with the fertilization rates of total macro-nutrients and with the kinds of soils. 5. The yield of mixed forages, yield component, and botanical composition in a mixed sward were greatly influenced by the ${\Sigma}A/{\Sigma}C$ ratios, the fertilization rates of total macronutrients, and the interactions of ratio and rate noted above. In addition, these effects were generally different and opposite according to grass and legume.

• Asian-Australasian Journal of Animal Sciences
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• v.9 no.6
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• pp.737-741
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• 1996

Dry matter yield of reed canarygrass was investigated in uncultivated rice paddy in Korea, and an attempt was made to estimate the most economic and efficient cutting frequency and rates of nitrogen (N) fertilization, for increased production of reed canarygrass. Total dry matter yields of reed canarygrass per year were 7.4-15.7, 8.5-16.1, and 7.5-13.4 tons/ha in 3, 4, and 5 cutting frequencies, respectively, and over the N treatments of 0-120 kg N/ha/cut. When cut 3 or 5 times annually, the 2nd cut produced the highest proportion of total yield at 38.4 and 33.0%, respectively, when cut 4 times the 3rd cut was highest (38.3%). The ranges of economic N level, limiting N level and efficiency of dry matter production were 243.3-293.0, 387.2, and 14.6 kg DM/kg N, respectively. These indicators were particularly low for the 5 cutting frequency possibly because of the unusually high temperature in the summer season. The best cutting frequency for the dry matter production of reed canarygrass in 1994 was 3 per year because of the higher efficiency of dry matter production.

• Korean Journal of Animal Reproduction
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• v.21 no.4
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• pp.355-362
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• 1997

This study was undertaken in an effort to product embryos through in vitro maturation(IVM), in vitro fertilization(IVF) and in vitro culture(IVC) after cryopreservation of immature and mature porcine oocytes. The experiments were conducted to investigate IVM rate of oocytes frozen with 3 different cryoprotectants and to examine IVF and IVC of frozen-thawed oocytes. The CEI(cumulus cells expansion index) after IVM of frozen-thawed immature oocytes was higher in oocytes frozen with PG＋PEG(propylene glycol plus polyethylene glycol) than those frozen with single cryoprotectant and this index was almost 90% of unfrozen oocyte's index(2.39 vs. 2.66). The IVF rate of all frozen oocytes was very low(68% of unfrozen oocytes) and the IVF rate of frozen immature oocytes was slightly higher than that of frozen mature oocytes(39.0% vs. 34.4%), but polyspermic penetration was higher in frozen immature oocytes(21.9% vs. 19.1%). The cleavage rate after IVF of frozen-thawed oocytes was 9.3% for frozen mature oocytes and 11.3% for frozen immature oocytes and this rate was significantly lower(P<0.05) than that of control(60.7%). The development to 8-cell stage was greatly lower in frozen mature oocytes than in frozen immature oocytes. The results indicate that the use of PG plus PEG as cryoprotectant may be very effective for vitrification of porcine oocytes and the frozen-thawed immature porcine oocytes can be used fro in vitro embryo production based on IVM, IVF and IVC system.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.118-118
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• 2003

The occurrence of Fusarium wilt in strawberry fields in Korea was assessed from 2001 to 2003. Fusarium wilt was found from June to August in nursery beds, from September to October after planting in production beds, and from January to March during harvest. The symptoms seen were root rots, discolored vascular tissue in the crown and deformation and yellowing of central leaflets. The disease occurred in up to 30％ of plants in 37 of 214 fields surveyed. Fusarium of sporum Schlecht. ex Fr. f. sp. fragariae was frequently isolated from cvs. Dochiodome, Maehyang, Redpearl, Samaberry and Akihime. Factors affecting the occurrence of Fusarium wilt were investigated; infested soils had high salt concentrations, low pH, OM, average P2O5 and exchangeable. Fusarium wilt was more frequent following conventional basal fertilization than after non-nitrogen basal fertilization and more frequent following the use of NH4-N than after NO3-N.