• Korean Journal of Environmental Biology
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• v.40 no.3
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• pp.267-274
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• 2022

Excess nitrogen (N) flowing from livestock manure to water systems poses a serious threat to the natural environment. Thus, livestock wastewater management has recently drawn attention to this related field. This study first attempted to obtain the optimal conditions for the further volatilization of NH₃ gas generated from pig wastewater by adjusting the amount of injected magnesia (MgO). At 0.8 wt.% of MgO (by pig wastewater weight), the volatility rate of NH₃ increased to 75.5% after a day of aeration compared to untreated samples (pig wastewater itself). This phenomenon was attributed to increases in the pH of pig wastewater as MgO dissolved in it, increasing the volatilization efficiency of NH₃. The initial pH of pig wastewater was 8.4, and the pH was 9.2 when MgO was added up to 0.8 wt.%. Second, the residual ammonia nitrogen (NH₄⁺-N) in pig wastewater was removed by precipitation in the form of struvite (NH₄MgPO₄·6H₂O) by adjusting the pH after adding MgO and H₃PO₄. Struvite produced in the pig wastewater was identified by field emission scanning electron microscopy (FE-SEM) and X-ray diffraction (XRD) analysis. White precipitates began to form at pH 6, and the higher the pH, the lower the concentration of NH₄⁺-N in pig wastewater. Of the total 86.1% of NH₄⁺-N removed, 62.4% was achieved at pH 6, which was the highest removal rate. Furthermore, how struvite changes with pH was investigated. Under conditions of pH 11 or higher, the synthesized struvite was completely decomposed. The yield of struvite in the precipitate was determined to be between 68% and 84% through a variety of analyses.

• Korean Journal of Breeding Science
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• v.51 no.3
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• pp.190-200
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• 2019

It is reported that the absence of lipoxygenase-3 (LOX-3) may contribute to a reduction in stale flavor after the storage of rice. To improve the quality of stored rice of the Korean japonica rice cultivar, we conducted a breeding program to develop near-isogenic rice without LOX-3 in the genetic background of Saenuri, a mega variety of Korea. In the first step of the breeding program, we used a donor parent of LOX-3 null, Daw Dam, and a recurrent japonica parent, Sindongjin, to develop HR27873-AC12 by backcross (BC₁), color test for introgression of lox-3, and anther culture for rapid fixation. In the second step, we used the donor parent, HR27873-AC12, and the recurrent parent, Saenuri, to develop HR28896-31-3-1-1 by backcross (BC₁), marker-assisted selection (MAS) for lox-3, and phenotypic selection (PS) for agronomic traits. Finally, in the third step, we developed HR30960-186-2-1-2-1 (Jeonju624), derived from a cross between Saenuri and HR28896-31-3-1-1, by MAS for lox-3 and PS with high selection pressure for agronomic characteristics. Jeonju624 was confirmed with the introgression of lox-3 by molecular marker. Jeonju624 was a mid-late maturing rice with similar agronomic characteristics to Saenuri, lodging tolerance with short culm, erect plant architecture, and resistance to bacterial blight and rice stripe virus. The yield components of Jeonju624 were mostly similar to Saenuri, except for the 1,000-grain weight of brown rice. The appearance of the grain of Jeonju624 was better than that of Saenuri, and the characteristics of cooked rice were similar to those of Saenuri. In the genetic background analysis using 406 KASP (Kompetitive Allele-Specific PCR) markers, Jeonju624 was confirmed to be the near-isogenic line (NIL) of Saenuri with a 95.8% recovery rate. Jeonju624 is the NIL of Saenuri without LOX-3, and overcomes the linkage drag of Daw Dam with similar agronomic characteristics and genetic background to Saenuri. Jeonju624 can be utilized as a practical cultivar to improve the quality of stored rice, breeding material for the introgression of lox-3, and genetic material to elucidate the effect of introgressed genes.

• Korean Journal of Agricultural and Forest Meteorology
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• v.25 no.4
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• pp.346-358
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• 2023

Due to the acceleration of climate change or global warming, it is important to predict rice productivity in the future and investigate physiological changes in rice plants. The research aimed to explore how rice adapts to climate change by examining the response of nitrogen absorption and nitrogen use efficiency in rice under elevated levels of carbon dioxide and temperature, utilizing the SPAR system for analysis. The temperature increased by +4.7 ℃ in comparison to the period from 2001 to 2010, while the carbon dioxide concentration was held steady at 800 ppm, aligning with South Korea's late 21st-century RCP8.5 scenario. Nitrogen was applied as fertilizer at rates of 0, 9, and 18 kg 10a^-1, respectively. Under conditions of climate change, there was an 81% increase in the number of panicles compared to the present situation. However, grain weight decreased by 38% as a result of reduction in the grain filling rate. BNUE, indicative of the nitrogen use efficiency in plant biomass, exhibited a high value under climate change conditions. However, both NUEg and ANUE, associated with grain production, experienced a notable and significant decrease. In comparison to the current conditions, nitrogen uptake in leaves and stems increased by 100% and 151%, respectively. However, there was a 25% decrease in nitrogen uptake in the panicle. Likewise, the nitrogen content and NDFF (Nitrogen Derived from Fertilizer) in the sink organs, namely leaves and roots, were elevated in comparison to current levels. Therefore, it is imperative to ensure resources by mitigating the decrease in ripening rates under climate change conditions. Moreover, there seems to be a requirement for follow-up research to enhance the flow of photosynthetic products under climate change conditions.

• Clean Technology
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• v.30 no.2
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• pp.123-133
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• 2024

Zeolite template carbon (ZTC) was synthesized as an adsorbent to remove low-concentration CH₄ from the atmosphere. The synthesis of ZTC was performed using CH₄ and C₂H₂ as carbon precursors and their impact on adsorption was investigated. ZTC was also synthesized using Y zeolite ion-exchanged with CaCl₂ and LiCl as templates to investigate the effect of using metals in ion exchange. The comparison of the carbon precursors revealed that C₂H₂ had a higher carbon yield than CH₄. The synthesized ZTC exhibited developed micropores due to carbon deposition deep inside the micropores of the zeolite template. The kinetic diameter of C₂H₂ (0.33 nm) is smaller than that of CH₄ (0.38 nm), which allowed for its deposition. The study compared metal precursors used for ion exchange and confirmed that the CaCl₂-based ZTC developed more micropores compared to the LiCl-based ZTC. The ion-exchanged Ca inhibited pore blocking by the carbon precursor, allowing it to enter the pores. The ability of synthesized ZTC to adsorb N₂ and CH₄ at 298 K was investigated. The results showed that CH₄ had a higher overall adsorption amount than N₂. The sample synthesized using C₂H₂ and CaY exhibited the highest N₂ and CH₄ adsorption capacity. However, the sample synthesized with CH₄ had the highest CH₄/N₂ gas uptake ratio, which is a crucial factor in designing an adsorption process. The observed difference was likely caused by the underdevelopment of ultrafine pores that are associated with N₂ adsorption. This resulted in a reduction of N₂ adsorption, leading to an increase in CH₄/N₂ separation.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.26 no.1
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• pp.1-31
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• 1981

Experiments were conducted to investigate rice varietal response to low water and air temperatures at different growth stages from 1975 to 1980 in a phytotron in Suweon and in a cold water nursery in Chooncheon. Germination ability, seedling growth, sterility of laspikelets, panicle exertion, discoloration of leaves, and delay of heading of recently developed indica/japonica cross(I/J), japonica, and indica varieties at low air temperature or cold water were compared to those at normal temperature or natural conditions. The results are summarized as follows: 1. Practically acceptable germination rate of 70% was obtained in 10 days after initiation of germination test at 15\circ_C for japonica varieties, but 15 days for IxJ varieties. Varietal differences in germination ability at suboptimal temperature was greatest at 16\circ_C for 6 days. 2. Cold injury of rice seedlings was most severe at the 3.0-and 3.5-leaf stage and it was reduced as growth stage advanced. A significant positive correlation was observed between cold injury at 3-leaf stage and 6-leaf stage. 3. At day/night temperatures of 15/10\circ_C seedlings of both japonica and I/J varieties were dead in 42 days. At 20/15\circ_C japonica varieties produced tillers actively, but tillering of I/J varieties was retarded a little. At 25/15\circ_C, both japonica and I/J varieties produced tillers most actively. Increase in plant height was proportional to the increase in all varieties. 4. In I/J varieties the number of differentiated panicle rachis branches and spikelets was reduced at a day-night temperature of 20-15\circ_C compared to 25-20 or 30-25\circ_C, but not in japonica varieties although panicle exertion was retarded at 20-15\circ_C. The number of spikelets was not correlated with the number of primary rachis branches, but positively correlated with that of secondary rachis branches. 5. Heading of rice varieties treated with 15\circ_C air temperature at meiotic stage was delayed compared to that at tillering stage by 1-3 days and heading was delayed as duration of low temperature treatment increased. 6. At cold water treatment of 17\circ_C from tillering to heading stage, heading of japonica, I/J, and cold tolerant indica varieties was delayed 2-6, 3-9, and 4-5 days, respectively, Growth stage sensitive to delay of heading delay at water treatment were tillering stage, meiotic stage, and booting tage in that order, delay of heading was greater in indica corssed japonica(Suweon 264), japonica(Suweon 235), and cold tolerant indica(Lengkwang) varieties in that order. Delay of heading due to cold water treatment was positively correlated with culm length reduction and spikelet sterility. 7. Elongation of culms and exertion of panicles of rice varieties treated with low air temperature 17\circ_C. Culm length reduction rate of tall varieties was lower than that of short statured varieties at low temperature. Panicle exertion was most severaly retarded with low temperature treatment at heading stage. Generally, retardation of panicle exertion of 1/1 varieties was more severe than that of japonica varieties at low temperature. There was a positive correlation between panicle exertion and culm length at low temperature. 8. The number of panicles was increased with cold water treatment at tillering stage, but reduced at meiotic stage. As time of cold water treatment was conducted at earlier growth stage, culm length was shorter and panicle exertion poorer. 9. Sterility of all rice varieties was negligible at 17\circ_C for three days but 30.3-85.2% of strility was observed for nine-day treatment at 17\circ_C. Among the tested varieties, sterility of Suweon 264 and Milyang 42 was highest and that of Suweon 290 and Suweon 287 was lowest. The most sensitive growth stage to low temperature induced sterility was from 15 to 5 days before heading. There was positive correlation between sterility of rice plants treated with low temperature at meiotic and heading stage. 10. Percentage of spikelet sterility was greatest at cold water treatment at meiotic stage (auricle distance -15～-10cm) and it was higher in 1/1 (Suweon 264, Joseng tongil), japonica (Nongbaek, Towada), and cold tolerance indica(Lengkwang) varieties in the order. Level of cold water and position of young-ear affected on the sterility of varieties at meiotic stage; percentage of spikelet sterility of variety, Lengkwang, of which young-ear was located above the cold water level was high, but that of short statured variety, Suweon 264, of which young-ear was located in the cold water was lower. 11. Percentage of ripened grains was not reducted at 15\circ_C air temperature for three days at full heading stage in all varieties. However, at six-day low temperature treatment Suweon 287, Suweon 264 showed percentage of ripended grains lower than 60%, but at nine-day low temperature treatment all varieties showed percentage of ripened grains lower than 60%. Low temperature treatment of 17\circ_C from 10 days after heading for 20 days did not affect on the ripening of all varieties. 12. Uptake of nitrogen, phosphorous, potassium, calcium, and magnesium in whole plants was higher at average air temperature of 25\circ_C, but concentration of the elements was lower compared to those at 19\circ_C. However, both total uptake and concentration of manganese were higher at 19\circ_C compared to 25\circ_C. 13. Higher application of nitrogen, phosphorus, silicate, and compost increased yield of rice due to increased number of panicles and spike let fertility in cold water irrigated paddy.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.17
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• pp.1-44
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• 1974

These studies were made at Suwon in 1972 and at Suwon, Iri, and Kwangju in 1973 to investigate grain filling process and variation of grain quality of NB 68513 and Caprock as hard red winter wheat, Suke ＃169 as soft red winter wheat variety and Yungkwang as semi-hard winter variety, grown under-three different fertilizer levels and seeding dates. Other experiments were conducted to find the effects of temperature, humidity and light intensity on the grain filling process and grain quality of Yungkwang and NB 68513 wheat varieties. These, experiments were conducted at Suwon in 1973 and 1974. 1. Grain filling process of wheat cultivars: 1) The frequency distribution of a grain weight shows that wider distribution of grain weight was associated with large grain groups rather than small grain group. In the large grain groups, the frequency was mostly concentrated near mean value, while the frequency was dispersed over the values in the small grain group. 2) The grain weight was more affected by the grain thickness and width than by grain length. 3) The grain weight during the ripening period was rapidly increased from 14 days after flowering to 35 days in Yungkwang and from 14 days after flowering to 28 days in NB 68513. The large grain group, Yungkwang was rather slowly increased and took a longer period in increase of endosperm ratio of grain than the small grain group, NB 68513. 4) In general, the 1, 000 grain weight was reduced under high temperature, low humidity, while it was increased under low temperature and high humidity condition, and under high temperature and humidity condition. The effect of shading on grain weight was greater in high temperature than in low temperature condition and no definite tendency was found in high humidity condition. 5) The effects of temperature, humidity and shading on 1, 000 grain weight were greater in large-grain group, Yungkwang than in small grain group, NB 68513. Highly significant positive correlation was found between 1, 000 grain weight and days to ripening. 6) The 1, 000 grain weight and test weight were increased more or less as the fertilizer levels applied were increased. However, the rate of increasing 1, 000 grain weight was low when fertilizer levels were increased from standard to double. The 1, 000 grain weight was high when planted early. Such tendency was greater in Suwon than in Kwangju or Iri area. 2. Milling quality: 7) The milling rate in a same group of varieties was higher under the condition of low temperature, high humidity and early maturing culture which were responsible for increasing 1, 000 grain weight. No definite relations were found along with locations. 8) In the varieties tested, the higher milling rate was found in large grain variety, Yungkwang, and the lowest milling rate was obtained from Suke ＃ 169, the small grain variety. But the small grained hard wheat variety such as Caprock and NB 68513 showed higher milling rate compared with the soft wheat variety, Suke ＃ 169. 9) There were no great differences of ash content due to location, fertilizer level and seeding date while remarkable differences due to variety were found. The ash content was high in the hard wheat varieties such as NB 68513, Caprock and low in soft wheat varieties such as Yungkwang and Suke ＃ 169. 3. Protein content: 10) The protein content was increased under the condition of high temperature, low humidity and shading, which were responsible for reduction of 1, 000 grain weight. The varietal differences of protein content due to high temperature, low humidity and shading conditions were greater in Yungkwang than in NB 68513. 11) The high content of protein in grain within one to two weeks after flowering might be due to the high ratio of pericarp and embryo to endosperm. As grains ripen, the effects of embryo and pericarp on protein content were decreased, reducing protein content. However, the protein content was getting increased from three or four weeks after flowering, and maximized at seven weeks after flowering. The protein content of grain at three to four weeks after flowering increased as the increase of 1, 000 grain weight. But the protein content of matured grain appeared to be affected by daily temperature on calender rather than by duration of ripening period. 12) Highly significant positive correlation value was found between the grain protein content and flour protein content. 13) The protein content was increased under the high level of fertilizers and late seeding. The local differences of protein content were greater in Suwon than in Kwangju and Iri. 14) Protein content in the varieties tested were high in Yungkwang, NB 68513 and Caprock, and low in Suke ＃ 169. However, variation in protein content due to the cultural methods was low in Suke ＃ 169. 15) Protein yield per unit area was increased in accordance with increase of fertilizer levels and early maturing culture. However, nitrogen fertilizer was utilized rather effectively in early maturing culture and Yungkwang was the highest in protein yield per unit area. 4. Physio-chemical properties of wheat flour: 16) Sedimentation value was higher under the conditions of high temperature, low humidity and high levels of fertilizers than under the conditions of low temperature, high moisture and low levels of fertilizers. Such differences of sedimentation values were more apparent in NB 68513 and Caprock than Yungkwang and Suke ＃ 169. The local difference of sedimentation value was greater in Suwon than in Kwangju and Iri. Even though the sedimentation value was highly correlated with protein content of grain, the high humidity was considered one of the factors affecting sedimentation value. 17) Changes of Pelshenke values due to the differences of cultural practices and locations were generally coincident with sedimentation values. 18) The mixing time required for mixogram was four to six minutes in NB 68513, five to seven minutes in Cap rock. The great variation of mixing time for Yungkwang and Suke ＃ 169 due to location and planting conditions was found. The mixing height and area were high in hard wheat than in soft wheat. Variation of protein content due to cultural methods were inconsistent. However, the pattern of mixogram were very much same regardless the treatments applied. With this regard, it could be concluded that the mixogram is a kind of method expressing the specific character of the variety. 19) Even though the milling property of NB 68513 and Caprock was deteriorated under either high temperature and low humidity of high fertilizer levels and late seeding conditions, baking quality was better due to improved physio-chemical properties of flour. In contrast, early maturing culture deteriorated physio-chemical properties, milling property of grain and grain protein yield per unit area was increased. However, it might be concluded that the hard wheat production of NB 68513 and Caprock for baking purpose could be done better in Suwon than in Iri or Kwangju area. 5. Interrelationships between the physio-chemical characters of wheat flour: 20) Physio-chemical properties of flour didn't have direct relationship with milling rate and ash content. Low grain weight produced high protein content and better physio-chemical flour properties. 21) In hard wheat varieties like NB 68513 and Caprock, protein content was significantly correlated with sedimentation value, Pelshenke value and mixing height. However, gluten strength and baking quality were improved by the increased protein content. In Yungkwang and Suk ＃ 169, protein content was correlated with sedimentation value, but no correlations were found with Pelshenke value and mixing height. Consequently, increase of protein content didn't improve the gluten strength in soft wheat. 22) The highly significant relationships between protein content and gluten strength and sedimentation . value, and between Pelshenke value, mixogram and gluten strength indicated that the determination of mixogram and Pelshenke value are useful for de terming soft and hard type of varieties. Determination of sedimentation value is considered useful method for quality evaluation of wheat grain under different cultural practices.

• Korean Journal of Weed Science
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• v.3 no.1
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• pp.75-99
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• 1983

The herbicidal properties of perfluidone [1,1,1-trifluoro-N-2-methyl-4-(phenylsulponyl) phenyl methanesulfonamide] were investigated in pots and paddy fields. At the rate of 2.0kg prod./10a, perfluidone did not cause any injury to the 4 leaf stage (LS) rice seedlings. Although the crop injury increased with increasing the application rate, the injury caused by 16kg prod. perfluidone/10a gave rise to only 30% yield reduction. The crop injury was greatest when perfluidone was applied 2 days before transplanting and decreased as the application time delayed. Perfluidone showed greater crop injury to the 3 LS seedlings, at more than 7cm water depth, and at high temperature than to the 4 LS seedlings, at 3-5cm water depth, and at low temperature. Indica and indica ${\times}$ japonica rice varieties were generally more sensitive to perfluidone than japonica rice variety. Perfluidone effectively controlled most of annual weeds and such perennial weeds as Sagittaria pygmaea MIQ., Potamogeton distinctus A. BENN, Cyperus serotinus ROTTB, Scirpus maritimus L., Eleocharis kuroguwai OHWL, and Scirpus hotarui OHWL, whereas Sagittaria trifolia L. and Polygonum hydropiper SPACH. were tolerent to perfluidone. The weeding effect decreased with increasing the leaching amount of water and the overflowing of irrigated water within 24 hours after the herbicide application. When the application time was done later than 8 days after transplanting, the perennial weeds were shown at deeper soil layers, and the standing water was deeper than 7cm, the effect tended to decrease. However, there was no difference in the weeding effect between soil types. Downward movement of perfluidone in flooded soil ranged from 2 to 8cm deep. The movement increased with increasing the leaching amount of water and the application rate and at a sandy loam soil which possessed less adsorptive capacity. Residual effect of perfluidone was found at 35 to 80 days after application, which varied such factors as Soil types. Increase in the leaching amount of water resulted in decrease in the period of the residual effect. The period was shorter at non-sterilized soil than at sterilized soil. The 0.75kg ai perfluidone + 1.5kg ai SL-49 (1,3-dimethyl-6-(2,4-dichlor-benzoyl)-5-phenacyloxy-pyrazole)/ha and 1.5kg ai perfluidone + 1.05kg ai bifenox (2,4-dichlorophenyl-3-methoxy carbonyl-4-nitro phenyl ether)/ha showed less crop injury than 1.5kg ai/ha perfluidone alone. However, the weeding effect of the former was similar to that of the later.

• Radiation Oncology Journal
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• v.22 no.3
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• pp.225-233
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• 2004

Purpose: The Ideal breast irradiation method should provide an optimal dose distribution In the treated breast volume and a minimum scatter dose to the nearby normal tissue. Physical wedges have been used to Improve the dose distribution In the treated breast, but unfortunately Introduce an Increased scatter dose outside the treatment yield, pavllculariy to the contralateral breast. The typical physical wedge (FW) was compared with 4he virtual wedge (VW) to do)ermine the difference In the dose distribution affecting on the treated breast and the contralateral breast, lung, heart and surrounding perlpheral soft tissue. Methods and Materials: The data collected consisted of a measurement taken with solid water, a Humanoid Alderson Rando phantom and patients. The radiation doses at the ipsllateral breast and skin, contralateral breast and skin, surrounding peripheral soft tissue, and Ipsllateral lung and heart were compared using the physical wedge and virtual wedge and the radiation dose distribution and DVH of the treated breast were compared. The beam-on time of each treatment technique was also compared Furthermore, the doses at treated breast skin, contralateral breast skin and skin 1.5 cm away from 4he field margin were also measured using TLD in 7 patients of tangential breast Irradiation and compared the results with phantom measurements. Results: The virtual wedge showed a decreased peripheral dose than those of a typical physical wedge at 15$^{\circ}$, 30$^{\circ}$, 45$^{\circ}$, and 60$^{\circ}$. According to the TLD measurements with 15$^{\circ}$ and 30$^{\circ}$ virtual wedge, the Irradiation dose decreased by 1.35$\%$ and 2.55$\%$ In the contralateral breast and by 0.87$\%$ and 1.9$\%$ In the skin of the contralateral breast respectively. Furthermore, the Irradiation dose decreased by 2.7$\%$ and 6.0$\%$ in the Ipsllateral lung and by 0.96$\%$ and 2.5$\%$ in the heart. The VW fields had lower peripheral doses than those of the PW fields by 1.8$\%$ and 2.33$\%$. However the skin dose Increased by 2.4$\%$ and 4.58$\%$ In the Ipsliateral breast. VW fields, In general, use less monitor units than PW fields and shoriened beam-on time about half of PW. The DVH analysis showed that each delivery technique results In comparable dose distribution in treated breast. Conclusion: A modest dose reduction to the surrounding normal tissue and uniform target homogeneity were observed using the VW technique compare to the PW beam in tangential breast Irradiation The VW field is dosmetrically superlor to the PW beam and can be an efficient method for minimizing acute, late radiation morbidity and reduce 4he linear accelerator loading bV decreasing the radiation delivery time.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.17 no.5
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• pp.353-360
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• 1984

As an effort to expand the utilization of mackerel which has been thought disadvantageous to processors due to the defects in bloody dark color of meat, high content of lipid, and low stability of protein, and to develope a new type of product, so called, preservative fish meat paste, the processing method was studied in which dielectric heating was applied by means of cooking, pasteurization, dehydration, and control of water activity. The principle of this method is based on that dielectric heating can initiate a rapid dispersion or displacement of moisture in the meat tissue so that the level of water acivity can be controlled by dehydration with hot air meanwhile the product is cooked, pasteurized, and texturized. And the product is finally heated with electric heaters and vacuum sealed to stabilize water activity and storage stability. In present paper, a formula for preparing the fish meat-stach paste, the conditions of dielectric heating and dehydration, shape and size of the product, and other parameters were tested to optimize the process operation. A formula of the fish meat-starch paste to provide proper textural properties and water activity was $10\%$ starch, $1.5\%$ salt, $3\%$ soybean, $0.6\%$ MSG, $2\%$ sucrose, and $3\%$ sorbitol against the weight of fish meat. A proper shape and size of the product to avoid foaming and case hardening during heating was sliced disc of 8 cm $diameter{\times}0.8$ cm thickness or $10{\times}10$ cm square plate with 1.0 cm thickness. The disc shape was recommended because it resulted more uniform heating, minimum foaming and case hardening. And it was also advantageous that disc was simply provided when the fish meat disc was stuffed in the same, solidified in boiling water for 2 to 3 minutes, and sliced. Condition of dielectric heating was critical to decide the levels of sterility, water activity, and textural property of the product. The temperature at the center of the meat disc slices was raised up to $95^{\circ}C$ in 1.5 minutes so that continuous exposure to microwave caused expanded tissue and hardening ending up with a higher water content. Heating for 5 to 6 minutes was adequate to yield the final water activity of 0.86 to 0.83(35 to $40\%$ moisture). It is important, however, that heating had to be done periodically, for instance, in the manner of 2.0, 1.5, 1.5, and 1.0 minute to give enough time to displace or evaporate moisture from the meat tissue. The product was dehydrated for 2 to 3 minutes by hot air of $60^{\circ}C$, 3 to 5m/sec and finally exposed to electric heaters for 5 to 6 minutes until the surface was roasted deep brown. These conditions of heating and dehydration resulted in a complete reduction of total plate count from an initial count of $5.3{\times}10^6/g$ to less than $3{\times}10^2/g$. General composition of the product was $40.1\%$ moisture, $20.8\%$ protein, $17.4\%$ lipid, $16.2\%$ carbohydrate, and $5.5\%$ ash. Textural properties revealed folding test AA, hardness 42, cohesiveness 0.53, toughness 4.6, and elasticity 0.8.

• The Korean Journal of Pharmacology
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• v.25 no.1
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• pp.115-134
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• 1989

Combined effects of ganciclovir (GCV) and vidarabine (ara-A) on the replication, DNA synthesis, and gene expression of wild type-1 herpes simplex virus (HSV-1) and three acyclovir (ACV)-resistant HSV-1 mutants were studied. These mutants include a virus expressing no thymidine kinase $(ACV^r)$, a virus expressing thymidine kinase with altered substrate specificity $(IUdR^r)$, and a mutant expressing altered DNA polymerase $(PAA^r5)$. GCV, an agent activated by herpesvirus specific thymidine kinase, showed potent antiviral activity against the wild type HSV-1(KOS) and DNA polymerase mutant $(PAA^r5)$. The ACV-resistant mutants with thymidine kinase gene $(ACV^r\;and\;IUdR^r)$ were resistant to GCV. All tested wild type HSV-1 or ACV-resistant HSV-1 mutants did not display resistance to vidarabine (are-A). Combined GCV and ara-A showed potentiating synergistic antiviral activity against wild type KOS and $PAA^r5$, and showed subadditive combnined ativiral activity against thymidine kinase mutants. Combined GCV and ara-A more significantly inhibited the viral DNA synthesis in wild type KOS and $PAA^r5-infected$ cells to a greater extent than either agent alone, but the synergism was not determined in $ACV^r$ or $IUdR^r-infected$ cells. These data clearly indicate that combined GCV and ara-A therapy might be useful for the treatment of infections caused by wild type HSV-1 or ACV-resistant HSV-1 with DNA polymerase mutation. ACV-resistant viruses with the mutation in thymidine kinase gene are also, resistant to GCV, but susecptible to ara-A, indicating that ara-A would the drug of choice for the treatment of ACV-resistant HSV-1 which does not express thymidine kinase or expresses thymidine kinase with altered substrate specificity. While the synthesis of viral ${\alpha}-proteins$ of wild type HSV-1 was not affected by ACV, GCV, ara-A, or combined GCV and ara-A, the synthesis of ${\beta}-proteins$ was slightly but significantly increased at the later stage of viral infection by the antiviral agents. The synthesis of ${\gamma}-proteins$ of wild type HSV- 1 was significantly inhibited by ACV, GCV, ara-A, and combined GCV and ara-A. Combined GCV $(5-{\mu}M)$ and ara-A $(100-{\mu}M)$ also significantly altered the expression of viral ${\beta}-and$ ${\gamma}-proteins$, of which efffct was similar to that of GCV $(10-{\mu}M)$ alone. Although ACV at the concentration of $10-{\mu}M$ did not alter the expression of ${\alpha}-$, ${\beta}-$, and ${\gamma}-proteins$ of ACV-resistant $PAA^r5$, GCV and ara-A significantly alter the epression of ${\beta}-and$ ${\gamma}-proteins$, not ${\alpha}-protein$, as same manner as they altered the expression of those proteins in cells inffcted with wild type HSV-1. Combined GCV $(5-{\mu}M)$ and ara-A $(100-{\mu}M)$ altered the expression ${\beta}-and$ ${\gamma}-proteins$ in $PAA^r5$ infected cells, and the effect of combined regimen was comparable of that of GCV $(10-{\mu}M)$. These data indicate that the alteration in the expression of ${\beta}-and$ ${\gamma}-proteins$ in wild type HSV-1 or $PAA^r5$ infected cells could be more significantly affected by combined GCV and are-A than individual GCV or ara-A. In view of the fact that (a) viral ${\alpha}-$, ${\beta}-$, and ${\gamma}-proteins$ are synthesized in a cascade manner; (b) ${\beta}-proteins$ are essential for the synthesis of viral DNA; (c) the synthesis of ${\beta}-proteins$ are inhibited by ${\gamma}-proteins$; and (d) most ${\gamma}-proteins$ are made from the newly synthesized progeny virus, it is suggested that GCV and ara-A, alone or in combination, primarily inhibit the synthesis of viral DNA, and by doing so might exhibit their antiherpetic activity. The alteration in viral protein synthesis in the presence of tested antiviral agents could result from the alteration in viral DNA synthesis. From the present study, it can be concluded that (a) combined GCV and ara-A therapy would be beneficial for the control of inffctions caused by wild type HSV-1 or ACV-resistant DNA polymerase mutants; (b) the combined synergistic activity of GCV and ara-A is due to further decrease in the viral DNA by the combined regimen; (c) ara-A is the drug of choice for the infection caused by ACV-resistant HSV-1 with thymidine kinase mutation; and (d) the alteration in viral protein synthesis by GCV and ars-A, alone or in combination, is mostly due to the decreased synthesis of viral DAN.