• Korean Journal of Weed Science
• /
• v.12 no.3
• /
• pp.261-270
• /
• 1992

Many herbicides that are applied at the soil before weed emergence inhibit plant growth soon after weed germination occurs. Plant growth has been known as an irreversible increase in size as a result of the processes of cell divison and cell enlargement. Herbicides can influence primary growth in which most new plant tissues emerges from meristmatic region by affecting either or both of these processes. Herbicides which have sites of action during interphase($G_1$, S, $G_2$) of cell cycle and cause a subsequent reduction in the observed frequency of mitotic figures can be classified as an inhibitor of mitotic entry. Those herbicides that affect the mitotic sequence(mitosis) by influencing the development of the spindle apparatus or by influencing new cell plate formation should be classified as causing disruption of the mitotic sequence. Sulfonylureas, imidazolinones, chloroacetamides and some others inhibit plant growth by inhibiting the entry of cell into mitosis. The carbamate herbicides asulam, carbetamide, chlorpropham and propham etc. reported to disrupt the mitotic sequence, especially affecting on spindle function, and the dinitroaniline herbicides trifluralin, nitralin, pendimethalin, dinitramine and oryzalin etc. reported to disrupt the mitotic sequence, particularly causing disappearence of microtubles from treated cells due to inhibition of polymerization process. An inhibition of cell enlargement can be made by membrane demage, metabolic changes within cells, or changes in processes necessary for cell yielding. Several herbicides such as diallate, triallate, alachlor, metolachlor and EPTC etc. reported to inhibit cell enlargement, while 2, 4-D has been known to disrupt cell enlargement. One potential danger inherent in the use of soil acting herbicides is that build-up of residues could occur from year to year. In practice, the sort of build-up that would be disastrous is unikely to occur for substances applied at the correct soil concentration. Crop injury caused by soil applied herbicides can be minimized by (1) following the guidance of safe use of herbicides, particularly correct dose at correct time in right crop, (2) by use of safeners which protect crops against injury without protecting any weed ; interactions between herbicides and safeners(antagonists) at target sites do occur probably from the following mechanisms (1) competition for binding site, (2) circumvention of the target site, and (3) compensation of target site, and another mechanism of safener action can be explained by enhancement of glutathione and glutathione related enzyme activity as shown in the protection of rice from pretilachlor injury by safener fenclorim, (3) development of herbicide resistant crops ; development of herbicide-resistant weed biotypes can be explained by either gene pool theory or selection theory which are two most accepted explanations, and on this basis it is likely to develop herbicide-resistant crops of commercial use. Carry-over problems do occur following repeated use of the same herbicide in an extended period of monocropping, and by errors in initial application which lead to accidental and irregular overdosing, and by climatic influence on rates of loss. These problems are usually related to the marked sensitivity of the particular crops to the specific herbicide residues, e.g. wheat/pronamide, barley/napropamid, sugarbeet/ chlorsulfuron, quinclorac/tomato. Relatively-short-residual product, succeeding culture of insensitive crop to specific herbicide, and greater reliance on postemergence herbicide treatments should be alternatives for farmer practices to prevent these problems.

• Journal of the Korean Chemical Society
• /
• v.39 no.3
• /
• pp.163-175
• /
• 1995

Metal free phthalocyanine($H_2Pc$) partially doped with iodine, $H_2Pc(I)x$, has been made to improve photosensitizing efficiency of ZnO/$H_2Pc$. The content of iodine dopant level(x) for $H_2Pc(I)x$ upon $H_2Pc$ polymorphs was characterized as ${\chi}-H_2Pc(I)_{0.92}$ and ${\beta}-H_2Pc(I)_{0.96}$ by elemental analysis. Characterization of iodine-oxidized $H_2Pc$ were investigated by TGA (thermogravimetric analysis), UV-Vis, FT-IR, Raman and ESR (electron spin resonance) spectrum, and the adsorption properties of $H_2Pc(I)x$ on ZnO were characterized by means of Raman and ESR studies. TGA for $H_2Pc(I)x$ showed a complete loss of iodine at approximately 265$^{\circ}C$ and the Raman spectrum of $H_2Pc(I)x$ and ZnO/$H_2Pc(I)x$ at 514.5 nm showed characteristic $I_3^-$ patterns in the frequency region 90∼550 $cm^{-1}$. ZnO/$H_2Pc(I)x$ exhibited a very intense and narrow ESR signal at $g=2.0025{\pm}0.0005$ compared to $H_2Pc$/ZnO. Iodine doped ZnO/$H_2Pc(I)x$ showed a better photosensitivity compared to iodine undoped ZnO/$H_2Pc$. That is, the surface photovoltage of ${\chi}-H_2Pc(I)_{0.92}$/ZnO was approximately 31 times greater than that of ZnO/${\chi}-H_2Pc$ and ZnO/${\beta}-H_2Pc(I)_{0.96}$ was 5 times more efficient than ZnO/${\beta}-H_2Pc$ at 670 nm. And the dependence of photosensitizing effect upon $H_2Pc$ polymorphs was exhibited that the surface photovoltage of ZnO/${\chi}-H_2Pc(I)_{0.92}$ was approximately 5 times greater than ZnO/${\beta}-H_2Pc(I)_{0.96}$ at 670 nm. Therefore Iodine doping of H_2Pc$ resulted in increase in photoconductivity of $H_2Pc$ and photovoltaic effect of ZnO/$H_2Pc$ in the visible region.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.33 no.1
• /
• pp.83-90
• /
• 2004

This study was conducted to examine the effects of $\beta$3-adrenergic receptor polymorphism on the blood glucose level and obesity in 530 volunteers, who attended a weight loss program in a local obesity clinic. The age differences in total subjects and the distribution of male and female were 26.55$\pm$0.31 yr, 9.1% (n=48), 90.9% (n=492). The genotype distribution of $\beta$3-AR gene polymorphism were WW type 75%, WR type 22% and RR type 3%. Among many parameters, fasting blood glucose was significantly higher in WR＋RR type (p=0.001) compared with WW type. When the subjects were divided into two groups by 6.105 mmol/L of the fasting blood glucose level, the frequency of hyperglycemia was 23.3% in WW type subjects, while there was a increase to 35.6% in WR＋RR type subjects (p=0.011, $\chi$$^2$-analysis). When hyperglycemia group was compared with normoglycemia group, obesity index (p=0.044), %body fat (p=0.046) and TG (p=0.000) were significantly higher, and HDL (p=0.006) was significantly lower in the hyperglycemia. When all of the above factors were included in stepwise logistic regression analysis to find risk factors of hyperglycemia, the results were that the odds ratio for hyperglycemia were 2.015 (p=0.011) for WR+RR type of $\beta$3-AR gene, 2.165 (p=0.000) for TG and 0.419 (p=0.059) for HDL cholesterol. There was a significantly positive correlation between the blood glucose vs BMI, WHR, body fat in the WW type (r=0.099, 0.119, 0.082) However, in the WR and RR type there were no significance between the blood glucose vs BMI, WHR, body fat. These data suggest that the WR＋RR genotype of $\beta$3-AR has a very strong association with increased blood glucose level and might be a significant risk factor for hyperglycemia among Korean subjects.

• Journal of Korean Academy of Nursing
• /
• v.22 no.4
• /
• pp.636-652
• /
• 1992

This study identified the impact of childhood cancer on the Korean family. The purpose was to contribute knowledge for family nursing and pediatric hospice care practice with sick children and their families. This descriptive study was conducted during a 6 month period with children who were being treated for cancer at six university hospitals in Seoul. The data were gathered from members of 68 families ; 24(Group A), with a child newly diagnosed with cancer : 27(Group B), with a child under treatment and without complications, and 17 (Group C), with a child in relapse. Medical records, structured questionnaires and interviews were used for data collection. The questionnaires and interview schedules had been used previously in Martinson's research in the USA and China. The findings, conclusions, and suggestions are as follows. 1. The impact of childhood cancer on the family. Members of the family experienced fear, helplessness, guilty feelings, and anger at the time of the initial diagnosis and at relapse. Mothers complained of headache, anorexia and poor appetite, weight loss, sleep disturbance, and bad dreams. Many of the fathers either lost or changed jobs, and all working mothers stopped working. Half the parents reported changes in their marital relationships such as frequent quarrels but also stronger unity. Family members perceived cancer as the most frightening disease. Change in their world view was expressed as living on faith understanding suffering, determining to live a better life, wanting to live an upright life and valuing health as the most important. Religious activities are found most helpful through this difficult experience. Financial debt due to the treatment and care of the sick child, burdened 22 families. The above mentioned impact was most evidant in Group B(those presently undergoing treatment) and Group C(those in relapse). Findings indicate that nursing care should embrace the family of a child who is being treated for cancer. 2. Characteristics of the child with cancer The majority of the children in this sample had a diagnosis of leukemia. Their mean age was 6.8 and the ratio of boys to girls was 1.12 ; 1. The mean hospitalization frequency was 13.5 times and the mean duration of illness was 16.8 months. Most of 1.he children perceived cancer as the most frightening disease ; 32.7% of the children described their sickness as serious. Children in Group C were hospitalized more frequently, stayed in hospital for longer periods, and expressed their sickness as quite serious more often than the other two groups. These findings indicate how much comprehensive pediatric hospice nursing care services are needed along with relevant research and nursing education. 3. Characteristics of the families. The mean age of the father was 39.5 and the mother, 36,6 ; they are in their most productive life period. Mothers especially expressed feelings of financial uneasiness and powerlessness about giving up their jobs, and guilty feelings for not providing enough care and concern to other children due to taking care of the sick one. The burden of caring for the sick child can bring negative changes in family dynamics which they think provoke potential health problems in members of the family These findings suggest a need for nursing support and counselling resources. Findings also suggest the need for ethical inquiry about such questions as who should give information to the child in regard to diagnosis and prognosis, when, and how. Other suggestions included : 1) Quality health care for childhood cancer such as home care and pediatric hospice programs should be established. 2) Special and practical consideration for long-term patients should be made in the present insurance coverage. The reimbursement period for long-term patients should be lengthened. 3) Further in-depth qualitative studies are needed. 4) Education programs including guided practice experience for pediatric hospice care practitioners are needed.

• Journal of Bio-Environment Control
• /
• v.25 no.1
• /
• pp.63-70
• /
• 2016

Water drainage from the open hydroponics often causes significant environmental pollution due to agrochemicals and loss of water and nutrients. The objectives of this study were to show the potential application of an irrigation schedule based on threshold values of volumetric substrate water content for tomato (Solanum lycopersicum L. 'Samsamgu') cultivation in a commercial hydroponic farm during spring to summer cultivation. This study was performed for minimizing effluent from coir substrate hydroponics using a frequency domain reflectometry (FDR) sensor-automated irrigation, as compared with an integrated solar-radiation (IR) and conventional timer-irrigation (TIMER) after transplanting. In results, no significant difference in daily irrigation volume was found among the treatments until 88 days after transplant (DAT). However, during the 88 to 107 DAT, the daily irrigation volume was in the order of IR (2125 mL) > TIMER (2063 mL) > FDR (1983 mL), and during the 108 to 120 DAT, it was in the order of IR (2000 mL) > TIMER (1664 mL) > FDR (1500 mL). The lowest drainage volume was observed in the FDR treatment with the order of IR (12~19%) > TIMER (4~12%) > FDR (0~7%) during the entire growing period. A lower irrigation volume in the FDR treatment after 88 DAT may be due to the sensor's detecting capacity for less water absorption by plant after completing fruit maturity with apical pruning and removal of lower leaves, while a higher irrigation volume in the IR treatment may be due to gradual increase in integrated solar-radiation amount as closer to summer season. There was no significant difference in plant growth and fruit yield among the treatments; however, a 11% and 18% of higher soluble sugar content was observed in the FDR than that of TIMER and IR treatment. respectively.

• Journal of Genetic Medicine
• /
• v.5 no.2
• /
• pp.119-124
• /
• 2008

Purpose: Aneuploidy is the cause of diseases such as Down syndrome or Edward syndrome and, more generally, is a major cause of mental retardation and fetal loss. The purpose of this study was to evaluate the association between MTHFR (C677T) or MTRR (A66G) polymorphisms and fetal aneuploidy. Materials and Methods: Data was collected from 37 women who had a fetus with aneuploidy (cases) and 78 women who had previously delivered at least two healthy children without aneuploidy and did not have a history of miscarriage or abnormal pregnancy (controls). The MTHFR (C677T) or MTRR (A66G) polymorphisms were analyzed by PCR-restriction fragment length polymorphism assay. Results: The frequencies of the MTHFR 677 CC, CT, and TT genotypes were 30.7%, 48.7%, and 20.6% in the control group and 37.8%, 48.6%, and 13.5% in the case group, respectively. There were no significant differences in genotype frequencies between the two groups. For the MTRR A66G polymorphism, the frequencies of the AA, AG and GG genotypes were 50%, 46.1%, and 3.9% in the control group and 13.5%, 81.1%, and 5.4% in case group, respectively. The frequency of the MTRR AG mutant was significantly increased in the case group, with an odds ratio of 6.5 (95% CI: 2.3-18.6, P<0.05). Conclusion: The results of this study suggest that mother carriers with the MTRR G allele have an increased risk of fetal aneuploidy, while the MTHFR T allele is not associated with increased risk of fetal aneuploidy. The MTRR A66G polymorphism may be a risk factor for producing a child with chromosomal aneuploidy.

• Journal of dental hygiene science
• /
• v.13 no.1
• /
• pp.13-19
• /
• 2013

This study evaluated the change of color and the microhardness according to time-out using the office bleaching with in vitro test after bleaching one time 1 day per week, total three times, for the control group and three times per 1day for the experimental group. $L^*$ was increased in both groups. Group 1 showed a significant increase statistically between before and after tooth whitening (p<0.05). Group 2 showed a significant increase statistically between before and after tooth whitening (p<0.05). ${\Delta}E^*$ was huge in both groups. In group 1, it was great in terms of statistical significance between 1 day and 7 days after tooth whitening (p<0.05). In group 2, it was the greatest between before and 1 day after tooth whitening and was significant statistically as well (p<0.05). Vickers hardness number (VHN) decreased in both groups. In group 1, VHN decreased over time and the difference was significant statistically (p<0.05). In group 2, VHN decreased over time and the difference was significant statistically (p<0.05). Percentage microhardness loss was great in both groups. In group 1, it was the greatest between 1 day and 7 days after the treatment, and it was significant statistically (p<0.05). In group 2, it was the greatest between before and 1 day after the treatment, and it was significant statistically (p<0.05). Put together, the more frequent tooth whitening a day is, the longer the period of tooth whitening when applying the same frequency, the greater color change was, however the microhardness decreased, in regard to the results over time using 15% hydrogen peroxide tooth whitening product for professionals.

• Journal of the Korean Vacuum Society
• /
• v.19 no.1
• /
• pp.36-44
• /
• 2010

The ambipolar diffusion equation has been solved in a fine-tube lamp of a few mm in diameter. In the diffusion of radial direction, the plasma diffuses and vanishes away at the glass wall by recombination with the characteristic time of plasma loss is given by $\tau_r\;=\;(r_0/2.4)^2/D_a$. With the radius $r_0{\sim}1\;mm$ and the ambipolar diffusion coefficient $D_a{\sim}0.01\;m^2/s$, the vanishing time is calculated $\tau_r{\sim}10\;{\mu}s$ which corresponds to the least value of frequency 30 kHz for the sustaining the plasma in the operation of high voltage AC-power. In the diffusion of longitudinal z-direction, a high density plasma generated at the area of a high voltage electrode, diffuses into the positive column with the characteristic time $\tau_z{\sim}0.1\;s$. The plasma diffusion velocity at the boundary of high density plasma is $u_D{\sim}10^2\;m/s$ at the time $t{\sim}10^{-6}$ s and the diffusion velocity becomes slow as $u_D{\sim}1\;m/s$ at $t{\sim}10^{-3}\;s$. Therefore, for the long lamp of 1 m, it takes about several seconds for the high density plasma at the area of electrode to diffuse through the whole positive column space.

• Clinical and Experimental Pediatrics
• /
• v.46 no.10
• /
• pp.966-971
• /
• 2003

Purpose : It is now well established that infection and inflammation play an important role in the pathogenesis of ischemic brain damage. The loss of neutrophils from systemic circulation is an associated finding in injury mediated by granulocyte. Periventricular leukomalacia(PVL) caused by ischemia is the principal form of brain injury in premature infants. This study was conducted to evaluate whether the low neutrophil count is associated with periventricular leukomalacia(PVL) in premature infants. Methods : Retrospective review of medical records was undertaken. Subjects were premature infants with a birth weight of less than 1,500 gm, admitted to the Neonatal Intensive Care Unit of Kyungpook University Hospital. A complete blood count of peripheral blood was done within the 1st hour of life. Neutropenia was defined as absolute neutrophil count < $1,500/mm^3$, PVL as increased periventricular echodensities followed by cyst formation on ultrasonography or corresponding signs on brain MRI. Results : Thirteen infants out of a total population of 37 revealed neutropenia. Respiratory distress syndrome and requirement for respiratory support were not different between infants with neutropenia( neutropenia group) and infants without neutropenia(control group). Intraventricular hemorrhage (IVH) and grade 3 and 4 IVH were more frequent in neutropenia group(P<0.05). There was no statistically significant increase of PVL in neutropenia group. The neutrophil count was $18,760.0{\pm}10,266.1/mm^3$, $7,272.0{\pm}7,435.0/mm^3$ infants with PVL and $11,131.7{\pm}3,386.5/mm^3$, $2,407.5{\pm}1,933.1/mm^3$ in infants without PVL, respectively. The frequency of mechanical ventilation and artificial surfactant therapy was higher in infants with PVL compared with infants without PVL, but statistical analysis was not performed due to small number of subjects. Conclusion : A low number of neutrophils in the systemic circulation was not associated with an increased risk of PVL in premature infants.

• Childhood Kidney Diseases
• /
• v.4 no.2
• /
• pp.102-110
• /
• 2000

Purpose : Intravenous infusion of albumin has been widely und to relieve severe nephrotic edema in spite of beneficial or harmful effects. The purpose of this study is to examine the harmful effect of albumin on the clinical course of steroid sensitive nephrotic syndrome(SSNS). Method : We prospectively randomized the patients with nephrotic syndrome(biopsy proven or clinically compatible to minimal change nephrotic syndrome) into the albumin group(20$\%$ albumin 1 g/kg) or control group(5$\%$ D/W) between March 1997 and September 1999 at Ewha University Mokdong Hospital. We compared the clinical course of the albumin group(n=13) with the control group(n=13). Results : 1. The duration of steroid therapy until complete remission in the albumin group was significantly longer than the control group($13.7{\pm}6.4\;days\;vs\;7.5{\pm}2.8\;days$)(P<0.05). 2. The remission duration to the first relapse was significantly shorter in the albumin group ($94{\pm}63.5$ days) than the control group($190{\pm}106.4$ days)(P< 0.05). There was no significant difference in the relapse rate within 1 year after complete remission[77$\%$ (10/13) vs 46$\%$ (6/13)](P>0.05) and the relapse frequency per year($1.9{\pm}0.8\;vs\;1.5{\pm}0.5$) between the albumin and control groups. 3. Spot urine protein/creatinine ratio significantly increased in the albumin group at post-albumin 2, 4 days(P<0.05). There was no significant difference in the change of the daily percent weight loss, blood pressure, serum Na, K concentration between the albumin and control groups. Conclusion : Albumin infusion in SSNS delayed the response to steroid and shortened the remission duration to the first relapse. Albumin should be carefully used in nephrotic edema.