• Title/Summary/Keyword: Generation After Generation

Search Result 2,927, Processing Time 0.034 seconds

Fate of Heavy Metals in Activated Sludge: Sorption of Heavy Metal ions by Nocardia amarae

  • Kim, Dong-wook
    • Proceedings of the Korean Environmental Sciences Society Conference
    • /
    • 1998.10a
    • /
    • pp.2-4
    • /
    • 1998
  • Proliferation of Nocardia amarae cells in activated sludge has often been associated with the generation of nuisance foams. Despite intense research activities in recent years to examine the causes and control of Nocardia foaming in activated sludge, the foaming continued to persist throughout the activated sludge treatment plants in United States. In addition to causing various operational problems to treatment processes, the presence of Nocardia may have secondary effects on the fate of heavy metals that are not well known. For example, for treatment plants facing more stringent metal removal requirements, potential metal removal by Nocardia cells in foaming activated sludge would be a welcome secondary effect. In contrast, with new viosolid disposal regulations in place (Code o( Federal Regulation No. 503), higher concentration of metals in biosolids from foaming activated sludge could create management problems. The goal of this research was to investigate the metal sorption property of Nocardia amarae cells grown in batch reactors and in chemostat reactors. Specific surface area and metal sorption characteristics of N. amarae cells harvested at various growth stages were compared. Three metals examined in this study were copper, cadmium and nickel. Nocardia amarae strain (SRWTP isolate) used in this study was obtained from the University of California at Berkeley. The pure culture was grown in 4L batch reactor containing mineral salt medium with sodium acetate as the sole carbon source. In order to quantify the sorption of heavy metal ions to N amarae cell surfaces, cells from the batch reactor were harvested, washed, and suspended in 30mL centrifuge tubes. Metal sorption studies were conducted at pH 7.0 and ionlc strength of 10-2M. The sorption Isotherm showed that the cells harvested from the stationary and endogenous growth phase exhibited significantly higher metal sorption capacity than the cells from the exponential phase. The sequence of preferential uptake of metals by N. amarae cells was Cu>Cd>Ni. The specific surFace area of Nocardia cells was determined by a dye adsorption method. N.amarae cells growing at ewponential phase had significantly less specific surface area than that of stationary phase, indicating that the lower metal sorption capacity of Nocardia cells growing at exponential phase may be due to the lower specific surface area. The growth conditions of Nocardia cells in continuous culture affect their cell surface properties, thereby governing the adsorption capacity of heavy metal. The comparison of dye sorption isotherms for Nocardia cells growing at various growth rates revealed that the cell surface area increased with increasing sludge age, indicating that the cell surface area is highly dependent on the steady-state growth rate. The highest specific surface area of 199m21g was obtained from N.amarae cell harvested at 0.33 day-1 of growth rate. This result suggests that growth condition not only alters the structure of Nocardia cell wall but also affects the surface area, thus yielding more binding sites of metal removal. After reaching the steady-state condition at dilution rate, metal adsorption isotherms were used to determine the equilibrium distributions of metals between aqueous and Nocardia cell surfaces. The metal sorption capacity of Nocardia biomass harvested from 0.33 day-1 of growth rate was significantly higher than that of cells harvested from 0.5- and 1-day-1 operation, indicatng that N.amarae cells with a lower growth rate have higher sorpion capacity. This result was in close agreement with the trend observed from the batch study. To evaluate the effect of Nocardia cells on the metal binding capacity of activated sludge, specific surface area and metal sorption capacity of the mixture of Nocardia pure cultures and activated sludge biomass were determined by a series of batch experiments. The higher levels of Nocardia cells in the Nocardia-activated sludge samples resulted in the higher specific surface area, explaining the higher metal sorption sites by the mixed luquor samples containing greater amounts on Nocardia cells. The effect of Nocardia cells on the metal sorption capacity of activated sludge was evaluated by spiking an activated sludge sample with various amounts of pre culture Nocardia cells. The results of the Langmuir isotherm model fitted to the metal sorption by various mixtures of Nocardia and activated sludge indicated that the mixture containing higher Nocardia levels had higher metal adsorption capacity than the mixture containing lower Nocardia levels. At Nocardia levels above 100mg/g VSS, the metal sorption capacity of activate sludge increased proportionally with the amount of Noeardia cells present in the mixed liquor, indicating that the presence of Nocardia may increase the viosorption capacity of activated sludge.

  • PDF

The Effect of $OPB-K^{(R)}$ on the Osseointegration and Stability of Implant ($OPB-K^{(R)}$가 임플랜트의 골유착 및 안정성에 미치는 영향에 관한 연구)

  • Kang, Sung-Jin;Cho, In-Ho;Shin, Soo-Yeon
    • The Journal of Korean Academy of Prosthodontics
    • /
    • v.46 no.1
    • /
    • pp.31-41
    • /
    • 2008
  • Statement of problem: It has been proved that Pleurotus eryngii Quel and Eleutherococcus senticosus have antiinflammatory action and not only stimulates the proliferation and activity of osteoblast but inhibits the generation and activity of osteoclast in vitro. Pleurotus eryngii Quel and Eleutherococcus senticosus are the main component of $OPB-K^{(R)}$. Purpose: The purpose of this study was to evaluate $OPB-K^{(R)}$ which enhances the healing rate of peri-implant bone and the bone mineral density. Materials and methods: Thirty six specially designed implants were installed in the tibia of rats. The group medicated with $OPB-K^{(R)}$ was the experimental group, and that without was the control group. hen the implant stability was measured by $Periotest^{(R)}$. Bone mineral density and histological measurement were conducted at the 2nd, 4th and 6th week $Periotest^{(R)}$ and bone mineral density values were analyzed statistically with independent t-test at 95% confidence level(p<0.05). Results: The results of this study were as follows : 1. There was no statistically significant difference in $Periotest^{(R)}$. values between the experimental group and control group at the 2nd week, however, on the 4th and 6th week there was significant difference(p<0.05). 2. There was no statistically significant difference in bone mineral density between the experimental group and control group at the 2nd and 4th week, however on the 6th week there was significant difference(p<0.05). 3. Histological analysis showed difference in osseointegration on the 4th and 6th week between the groups. Conclusion: From the results, it is concluded that the $OPB-K^{(R)}$ medicated group showed statistically better results in bone density and stability than the control group. Clinically it would be better to medicate $OPB-K^{(R)}$ to patients for a long period of time after implantation to get superior results.

Analysis on Family Value of the Family with Cancer Children (암환아 가족의 가족 가치관 분석)

  • Park In-Sook;Kim Dal-Sook
    • Child Health Nursing Research
    • /
    • v.7 no.3
    • /
    • pp.322-341
    • /
    • 2001
  • The family value is expected to play a crucial role in adjusting a new environment for the family, especially in the critical situation as having a child with cancer in the family. The purpose of the study was to analyze the family values of the family with cancer children in order to offer descriptive data, which will facilitate family adjustment with cancer children. The survey was conducted from July 18, 2000 to August 30, 2000 and the analysis included 309 parents of the children who have been diagnosed as cancer, 18 years of age or less, and treated either hospitalized or at the outpatient clinics. Two instruments were used to measure family value. The modified form of General family value scale was 18 items with a 5 points of Likert response format (Cronbach alpha= .78) and Family value scale was developed for the study with 12 items on a 5 points of Likert response format(Cronbach alpha= .73). The data analysis utilized SAS 6.12 for percentage, frequency, Mean, and t-test of demographic characteristics and mean, F score, ANOVA, and Duncan follow-up test of variable relationships. The study findings were as follows. 1) In General family value, the fathers gave the higher scores to 'The children should live with their parents'(M=4.01), and 'A parents and their children are like one body' (M=3.91). The item with lowest score was 'Its not impossible for man to have extramarital relationship'(M=1.92). The mothers thought the most important items were 'A parents and their children are like one body'(M=3.79), and 'A wife needs to be patient to keep harmony of the family' (M=3.56), and the item with lowest score was 'Its not impossible for man to have extramarital relationship'(M=1.44). 2) The mean scores of the mothers were higher than the fathers for all items in family value with cancer children, while fathers gave more points for items in general family value. Both of parents gave the highest score to 'The health of the family is most important to me'(M=4.85 for fathers, M=4.97 for mothers), and followed by 'The husband and wife need to be patient and understand each other to overcome the difficulties'. The item with lowest scores was 'The parents can have conflicts in making decisions since their child was sick'(M=3.34 for fathers, M=3.37 for mothers). 3) There were significant differences between fathers and mothers in items of General family value; fathers gave more points to the items of 'The children should live with their parents', 'Its essential to hold the ceremony to respect their forefathers', 'Its not impossible for man to have extramarital relationship', 'A woman with two daughters should have one more baby to succeed the generation', 'The husbands are responsible for the household economy', and 'When his mother and wife dont get along, the man should be on his mothers side'. However, there was no significant difference between fathers and mothers in items of Family value with cancer children. 4) The general family value was significantly different by the birth order of cancer children, mothers age, mothers education level, and types of payment. On the other hand, the family value with cancer children was significantly different by the age of cancer children, period of illness, period after completing treatment, family type, the number of family members, and the number of total children.

  • PDF

Evaluation of Renal Oxygenation in Normal Korean Volunteers Using 3.0 T Blood Oxygen Level-Dependent MRI (3.0 T 혈중산소치의존 자기공명영상을 이용한 정상한국인에서의 신장 산소공급의 평가)

  • Hwang, Sung Il;Lee, Hak Jong;Chin, Ho Jun;Chae, Dong-Wan;Na, Ki Young
    • Investigative Magnetic Resonance Imaging
    • /
    • v.17 no.1
    • /
    • pp.19-25
    • /
    • 2013
  • Purpose : Renal blood oxygen level-dependent (BOLD) MRI has been used in the evaluation of renal oxygenation. We tried to provide the normal $R2^*$ value of the human kidney with 3.0 T, and evaluated the differences in $R2^*$ values according to gender and location. Materials and Methods: Twenty-four healthy volunteers underwent BOLD MRI at 3.0 T. Multi gradient echo-echo planar imaging sequence with seventeen echoes was used. After generation of the $T2^*$ map, the $R2^*$ was calculated. The statistical differences in $R2^*$ values between the cortex and medulla, males and females, and the right and left kidney were analyzed. The regional differences of $R2^*$ within the both kidneys were evaluated respectively. Results: BOLD MRI was successful in all participants. No gross artifact interfered with $R2^*$ measurement. The mean $R2^*$ at 3.0 T was $17.1{\pm}2.60s^{-1}$ in the cortex and $27.7{\pm}4.83s^{-1}$ in the medulla (p < 0.001). The $R2^*$ value in the medulla was significantly higher in the male than female volunteers (p = 0.025). There were no statistical differences of $R2^*$ according to the side and location in the kidney (p = 0.197). Conclusion: Renal BOLD MRI can be efficiently performed with 3.0 T MRI. Renal medullary hypoxia is present in normal volunteers. Our results may be used as reference values in the evaluation of pathologic conditions using BOLD MRI.

3-Dimensional Micro-Computed Tomography Study on Bone Regeneration with Silk Fibroin, rh-Bone Morphogenetic Protein Loaded-Silk Fibroin and Tricalcium Phosphate Coated-Silk Fibroin in Rat Calvaria Defect

  • Pang, Eun-O;Park, Young-Ju;Park, Su-Hyun;Kang, Eung-Sun;Kweon, Hae-Yong;Kim, Soeng-Gon;Ko, Chang-Yong;Kim, Han-Sung;Nam, Jeong-Hun;Ahn, Jang-Hun;Chun, Ji-Hyun;Lee, Byeong-Min
    • Maxillofacial Plastic and Reconstructive Surgery
    • /
    • v.34 no.1
    • /
    • pp.1-11
    • /
    • 2012
  • Purpose: The purpose of this study was to evaluate the bone regeneration capacity of silk fibroin (SF) when combined with beta tricalcium phosphate (${\beta}$-tricalcium phosphate [TCP]) and rh-bone morphogenetic protein (BMP) in vivo by micro-computed tomography (CT), soft x-ray, and histological analysis. Methods: A total of 56 critical size defects formed by a trephine bur made on 28 adult female Spague-Dawley rats were used for this study and the defect size was 5.0 mm in diameter. The defects were transplanted with (1) no graft material (raw defect), (2) autogenous bone, (3) SF ($10{\mu}g$), (4) SF-BMP ($10{\mu}g$, $0.8{\mu}g$ each), and (5) SF+${\beta}$-TCP ($10{\mu}g$). At 4 and 8 weeks after operation, the experimental animals were sacrificed. Samples were evaluated with soft x-ray, histological examinations and 3-dimensional micro-CT analysis. Results: In the 3-dimensional micro-CT evaluation, bone volume and bone surface data were higher in the SF-BMP ($12.8{\pm}1.5$, $138.6{\pm}45.0$ each) (P<0.05) and SF-TCP ($12.3{\pm}1.5$, $144.9{\pm}30.9$ each) group than in the SF group ($6.1{\pm}3.3$, $77.2{\pm}37.3$ each) (P<0.05), except for the autogenous group ($15.0{\pm}3.0$, $190.7{\pm}41.4$ each) at 4 weeks. At 8 weeks, SF-BMP ($16.8{\pm}3.5$, $173.9{\pm}34.2$ each) still revealed higher (P<0.05) bone volum and surface, but SF-TCP ($11.3{\pm}1.5$, $1132.9{\pm}52.1$ each) (P=0.5, P=0.2) revealed the same or lower amount compared with the SF group ($13.8{\pm}2.7$, $127.5{\pm}44.8$ each). The % of bone area determined by radiodensity was higher in the SF-TCP ($31.4{\pm}9.1%$) and SF-BMP ($36.2{\pm}16.2%$) groups than in the SF ($19.0{\pm}10.4$) group at the period of 4 weeks. Also, in the histological evaluation, the SF-BMP group revealed lower inflammation reaction, lower foreign body reaction and higher bone healing than the SF group at postoperative 4 weeks and 8 weeks. The SF-TCP group revealed lower inflammation at 4 weeks, but accordingly, as the TCP membrane was absorbed, inflammatory and foreign body reaction are increased at 8 weeks. Conclusion: The current study provides evidence that the silk fibrin can be used as an effective grafted material for tissue engineering bone generation through a combination of growth factor or surface treatment.

Effect of Boric Acid on In Vitro Pollen Germination in Transgenic Plants Expressing Monoclonal Antibodies (단일항체를 발현하는 형질전환 식물체의 In Vitro 화분발아에 대한 Boric Acid의 영향)

  • Ahn, Mi-Hyun;Lee, Kyung-Jin;Ko, Ki-Sung
    • Journal of Plant Biotechnology
    • /
    • v.34 no.4
    • /
    • pp.339-346
    • /
    • 2007
  • Pollen germination viability is an essential factor to produce seeds from pollination and fertilization, which are required to maintain plant generation. In this study, we tried to identify the effect of boric acid on pollen germination and tube grouch in non-transgenic and transgenic plants expressing monoclonal antibodies (anti-colorectal cancer mAb CO17-1A, anti-breast cancer mAb BR55, and anti-rabies virus mAb57). The pollen of non-transgenic plant was treated with different concentration of boric acid (0, 5, 10, 15, 20, $40{\mu}g/mL$) in germination buffer to investigate its effect on in vitro pollen germination. At $20{\mu}g/mL$ of boric acid, tile pollen germination rate was the highest (49.5%) compared to other concentrations. In general, the germination rate significantly increased 3-10 folds in boric acid ($20{\mu}g/mL$) treated group in non-transgenic and transgenic plants. Also, the pollen tube length increased in boric acid ($20{\mu}g/mL$) treated groups. In the treated group, the pollen tube length increased until 3 h boric acid treatment and decreased after the 3 h, indicating that the 3 h is the most appropriate incubation time period. Western blot analysis showed that the mAb transgene expression was more stable in leaf than pollen in transgenic plants. This study suggested that $20{\mu}g/mL$ of boric acid is ideal concentration to induce in vitro pollen germination of transgenic plants expressing therapeutic monoclonal antibodies, indicating stable pollination and fertilization in transgenic plants.

Prototypes of Panaxadiol and Panaxatriol Saponins Suppress LPS-mediated iNOS/NO Production in RAW264.7 Murine Macrophage Cells (RAW264.7 대식세포에서 LPS 매개 iNOS/NO 생성에 대한 protopanaxadiol saponin 및 protopanaxatriol saponin의 억제효과)

  • Kim, Jin-Ik;Narantuya, Nandintsetseg;Choi, Yong-Won;Kang, Dae-Ook;Kim, Dong-Wan;Lee, Kyoung;Ko, Sung-Ryong;Moon, Ja-Young
    • Journal of Life Science
    • /
    • v.26 no.12
    • /
    • pp.1422-1430
    • /
    • 2016
  • This study was performed to investigate the modulatory effects of two prototypes of Panax ginseng saponin fractions, 20(S)-protopanaxadiol saponins (PDS) and 20(S)-protopanaxatriol saponins (PTS), on the induction of inflammatory mediators in lipopolysaccharide (LPS)-treated RAW264.7 murine macrophage cells. For this purpose, RAW264.7 cells were treated with LPS ($10{\mu}g/ml$) before, after, or simultaneously with PDS or PTS ($150{\mu}g/ml$), and the released level of nitric oxide (NO) and expression levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) were evaluated. When RAW264.7 cells were treated with LPS and ginseng saponin fractions simultaneously for 24 hr, PTS, compared to PDS, more strongly attenuated the NO production induced by LPS treatment. When the cells were pretreated with LPS for 2 hr followed by PDS or PTS treatment for 24 hr, both ginseng saponins strongly reduced NO release. The pretreatment of RAW264.7 cells with PDS or PTS for 2 hr followed by LPS treatment for 24 hr significantly attenuated the LPS-induced production of NO. PTS showed stronger inhibitory potency to NO generation than PDS. Our western blot experiment showed that both PDS and PTS ($150{\mu}g/ml$) also significantly down-regulated the expressions of iNOS and COX-2 induced by LPS treatment. Our results suggest that both PDS and PTS possess strong protective effects against LPS-stimulated inflammation and that their protective effects are mediated by the suppression of NO synthesis via down-regulation of pro-inflammatory enzymes, iNOS, and COX-2 in the RAW264.7 cells.

Breakthrough Urinary Tract Infection: A Clinical Study of Experience of a Single Center (예방적 항생제 사용중에 발생한 요로감염: 단일 병원에서 경험한 임상연구)

  • Bae, Sang-In;Cheon, Chong-Kun;Kim, Su-Young
    • Childhood Kidney Diseases
    • /
    • v.14 no.2
    • /
    • pp.203-209
    • /
    • 2010
  • Purpose : It has been a common medical practice to use prophylactic antibiotics to prevent recurrent urinary tract infections (UTI) in high risk situations such as urinary tract obstruction, vesicoureteral reflux, neurogenic bladder, or urinary stones. But sometimes, we meet difficult situation of breakthrough infections (BI) which might cause new or progressive renal scarring. The clinical characteristics of children contracting breakthrough UTI experienced in a single center were studied. Methods : The study was done retrospectively through medical records of 150 pediatric patients who had been cared in pediatric and urologic clinics of Pusan National University Hospital from Jan. 2001 till June 2006 and had prophylactic antibiotics to prevent recurrent UTI. Results : The starting age of prophylactic antibiotics of 150 patient was 1-76 months, and median age was 5 months. The BI developed 61 times in 43 patients (28.7%), 1.5 times per 100 patient-months. The BI occurred more frequently in patients with higher grade of VUR, and in the cases with abnormal DMSA scan. Co-trimoxazole was more effective than 2nd and 3rd generation cephalosporins to prevent UTI. The distribution of causative organisms was more diverse than usual UTI. The causative organisms were sensitive to the antibiotics used for prophylaxis in 29.5%, and resistant in 59.1%. After experience of BI, 40 percents of patients went to the surgical treatment including endoscopic injection of Deflux, 35% to new antibiotics for prophylaxis, 26% remain on the same antibiotics as the previous one. Conclusion : Based on our study results, preexisting renal scar might be one of the factors which should be considered in favor of early surgical interventions of VUR. Poor compliance and wrong selection of antibiotics such as cephalosporins are important underlying causes of breakthrough UTIs.

Effects of Inorganic Nutrients and Heavy Metals on Germination of the Green Alga, Ulva pertusa Kjellman (녹조 구멍갈파래 (Ulva pertusa Kjellman)의 발아에 미치는 무기영양염류 및 중금속의 영향)

  • 김장균;한태준
    • Korean Journal of Environmental Biology
    • /
    • v.19 no.1
    • /
    • pp.7-17
    • /
    • 2001
  • Growth optima and tolerance ranges of marine algae species nay vary greatly during the developmental stage. The establishment stage is clearly of great importance for each generation, affecting the performance of the adult population. The present study was aimed to determine the effect of various concentrations of inorganic nutrients and heavy metals on germination and germlings of Ulva pertusa Kjellman (Chlorophyta). Percent germination increased rapidly as irradiance level increased, reaching the maximum at 100 ${\mu}$mol m$\^$-2/s$\^$-1/ in both east and west seawater. Percent germination in the east seawater was higher than that in the west seawater at irradiances lower than 30 ${\mu}$mol m$\^$-2/s$\^$-1/, and there was no difference in percent germination between the two different seawaters at irradiances higher than 60 ${\mu}$mol m$\^$-2/s$\^$-1/. Germling growth increased in the both cases with increasing irradiances but no growth was found in the dark. Overall germling area was larger in the east seawater than in the west seawater. Number of cell increased with increasing irradiance and became light-saturated at 100 ${\mu}$mol m$\^$-2/s$\^$-1/ in the both cases. Germlings grown in the east seawater had more cells than those cultivated in the west seawater at irradiances lower than 60 ${\mu}$mol m$\^$-2/s$\^$-1/. In various combinations of nitrate and phosphate, percent germination increased with increasing nitrate concentrations irrespective of phosphate concentrations. At 3 days after inoculation, nitrate concentration of 2.5 ppm with all phosphate concentrations promoted germination. Area and number of cell of germlings increased with increasing nitrate concentrations in all phosphate concentrations. In various combinations of copper and lead, germination was delayed as copper concentrations increased in all lead concentrations. Percent germination was severely reduced at 1 ppm Cu$\^$2+/. Area and number of cell of germlings decreased with increasing copper concentrations in all lead concentrations. The highest copper concentration (1 ppm) clearly suppressed the germling growth in U. pertusa.

  • PDF

Evaluation of Agronomic Characteristics, Nutritional Contents, and Insect Response of the Transgenic Potato Resistant to Glufosinate Ammonium (제초제 저항성 형질전환 감자의 농업적 특성, 영양 성분 및 해충 반응성 평가)

  • Ahn, Soon-Young;Cho, Kwang-Soo;Seo, Hyeo-Won;Yi, Jeong-Yoon;Bae, Shin-Cheol;Cho, Ji-Hong;Park, Young-Eun;Kim, Ju-Il;Kim, Hyun-Jun;Cho, Hyun-Mook
    • Horticultural Science & Technology
    • /
    • v.29 no.3
    • /
    • pp.247-254
    • /
    • 2011
  • The agronomic characteristics, nutritional contents, and insect response of the potato clones transformed with a glufosinate ammonium resistance gene were evaluated. Among the 4 transgenic potato clones, the Bar 3 clone was selected as a promising one for commercialization. The Bar 3 clone showed similar tuber yield capacity but higher herbicide resistance as compared with the non-transgenic potato cv. Dejima. The herbicide resistance of the Bar 3 clone was more than 5 times higher when tested with the herbicide concentration recommended by the producer. The major agronomic characteristics of the Bar 3 clone were not different from those of the non-transgenic Dejima. The annual variation in yields and agronomic characteristics showed similar tendency for 2 years from the third to fourth generation after transformation. The tubers of the Bar 3 clone also showed low occurrence in common scab and physiological disorders such as cracking and secondary growth. But the reasons for such results are yet to be studied. Also, it was considered that the Bar 3 clone have a potential of reducing not only common scab occurrence but also soil erosion during potato cultivation in field. The nutritional contents (mineral compound, vitamin C and amino acid) and response to Spodoptera exigua of the transgenic potato clones were not significantly different.