• Title/Summary/Keyword: lead(II)

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Therapeutic Effects of (+)-Afzelechin on Particulate Matter-Induced Pulmonary Injury

  • Sanghee Cho;Yun Jin Park;Jong-Sup Bae
    • Biomolecules & Therapeutics
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    • v.32 no.1
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    • pp.162-169
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    • 2024
  • Particulate matter (PM) constitutes a hazardous blend of organic and inorganic particles that poses health risks. Inhalation of fine airborne PM with a diameter of ≤ 2.5 ㎛ (PM2.5) can lead to significant lung impairments. (+)-afzelechin (AZC), a natural compound sourced from Bergenia ligulata, boasts a range of attributes, including antioxidant, antimicrobial, anticancer, and cardiovascular effects. However, knowledge about the therapeutic potential of AZC for patients with PM2.5-induced lung injuries remains limited. Thus, in this study, we investigated the protective attributes of AZC against lung damage caused by PM2.5 exposure. AZC was administered to the mice 30 min after intratracheal instillation of PM2.5. Various parameters, such as changes in lung tissue wet/dry (W/D) weight ratio, total protein/total cell ratio, lymphocyte counts, levels of inflammatory cytokines in bronchoalveolar lavage fluid (BALF), vascular permeability, and histology, were evaluated in mice exposed to PM2.5. Data demonstrated that AZC mitigated lung damage, reduced W/D weight ratio, and curbed hyperpermeability induced by PM2.5 exposure. Furthermore, AZC effectively lowered plasma levels of inflammatory cytokines produced by PM2.5 exposure. It reduced the total protein concentration in BALF and successfully alleviated PM2.5-induced lymphocytosis. Additionally, AZC substantially diminished the expression levels of Toll-like receptors 4 (TLR4), MyD88, and autophagy-related proteins LC3 II and Beclin 1. In contrast, it elevated the protein phosphorylation of the mammalian target of rapamycin (mTOR). Consequently, the anti-inflammatory attribute of AZC positions it as a promising therapeutic agent for mitigating PM2.5-induced lung injuries by modulating the TLR4-MyD88 and mTOR-autophagy pathways.

Analysis of a Cross-cutting Issue, 'Access to Genetic Resources and Benefit-sharing' of the Conference of the Parties to the Convention on Biological Diversity (생물다양성협약 당사국회의의 핵심논제인 '유전자원에 대한 접근과 이익의 공유'에 관한 고찰)

  • Park, Yong-Ha
    • Journal of Environmental Policy
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    • v.6 no.1
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    • pp.41-60
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    • 2007
  • Attempts were made to define the elements of debates, impact of decisions of the Access to Genetic Resources and Benefit-sharing(ABS) of the Conference of the Parties(COP) to the Convention on Biological Diversity(CBD) In Korea. Providing policy suggestions to cope with ABS, a cross-cutting issue of the meetings of the COP, was also undertaken. Meetings concerning ABS deal with several key matters such as an international regime, which is a legally binding implementation tool of the Bonn Guidelines, an international certificate of genetic resources' origin/source/legal provenance, and disclosure of origin of genetic resources, compliance measures with prior informed consent of the Contracting Parties providing such resources and with mutually agreed terms on which access was granted. Developing countries, rich in biodiversity and genetic resources, use the CBD as a major tool to maximize their national profits. They demand for national sovereign rights for the genetic resources and indigenous communities providing associated traditional knowledge. At the meetings of the COP, in addition, they requested that developed countries should transfer technologies and provide a financial mechanism for resource conservation to them. On the contrary, the developed countries argue that facilitating access to genetic resources is essential for scientific research and development, and that both Intellectual Property Rights and biotechnology using genetic resources should be protected to maximize their national benefits. Decisions of the COP concerning the Bonn Guidelines and compliance measures with ABS will affect on various socioeconomic fields of Korea, a country which is short of genetic resources. Especially, the importation of genetic resources and land development which might damage genetic resources will be limited seriously. Consequently, overall expenses will increase for the securing genetic resources from the foreign countries and developing biotechnology for conservation and sustainable uses of genetic resources. To minimize the adverse impacts, we endeavor to establish our clear standpoint and to lead the international trends, which are favorable for us. In order to achieve these objectives, government needs i) to proceed researches to lead the international ABS debates actively and to prepare the expected decisions of the future meetings of the COP, ii) to establish a national implementation plan to cope with the ABS and its related decisions, iii) to examine and improve the efficiencies of the national implementation plan with a proper monitoring system, and iv) cope with the other international meetings including the meetings of Trade Related Intellectual Properly Rights and International Treaty on Plant Genetic Resources for Food and Agriculture actively.

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Studies on electrocardiogram of the normal Korean native cattle II. Wave forms and amplitudes of the unipolar precordial chest leads (정상적(正常的)인 한우(韓牛)의 심전도(心電圖)에 관(關)한 연구(硏究) II. 흉부단극유도(胸部單極誘導)의 파형(波形)과 전위(電位))

  • Choi, In-hyuk;Kim, Soo-young;Kim, Nam-soo;Suh, Doo-seok
    • Korean Journal of Veterinary Research
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    • v.33 no.4
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    • pp.735-746
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    • 1993
  • Electrocardiographic parameters of amplitude and the shape of waves on the unipolar precordial chest leads in the normal Korean native cattles have been measured with a 3 channel electrocardiograph built in a computed and analysis. The study was conducted on 98 heads of mean age of 17.6 months. The wave forms of P, T and QRS complex wave in all leads showed various types. The parameters of the amplitude in the wave types showed the most frequency in each lead that were analyzed as follow : 1. In P wave, amplitudes of positive type showed a frequency of 92.9% and 93.9% in leads $CV_6LU$ and $CV_6LL$ that were $83.8{\pm}31.0{\mu}V$ and $76.0{\pm}30.7{\mu}V$, and negative type showed a frequency of 97.9% in lead V 10 that were $-80.2{\pm}29.4{\mu}V$, respectively. But the plate type in leads $CV_6RU$ and $CV_6RL$ showed frequency of 48% and 58.3%, respectively. 2. Average amplitude of the QRS complex were in a range of $277.0{\pm}154.0{\mu}V$ to $648.2{\pm}146.2{\mu}V$(mean of $418.8{\pm}139.4{\mu}V$) in all leads that were manifested the Low-Voltage QRS complex(below 1 mV in unipolar precordial leads). Average amplitudes of each wave type in the QRS complex were $-250.0{\pm}139.8{\mu}V$ and $-399.2{\pm}226.8{\mu}V$ in the QS group types that showed a frequency of 50.0% and 82.5% in the leads $CV_6LU$ and $CV_6LL$, respectively. And average amplitudes of the R group types showed a frequency of 85.6%, 56.1% and 75.8% in the $CV_6RU$, $CV_6RL$ and $V_{10}$ that were $321.5{\pm}142.1{\mu}V$, $271.6{\pm}139.9{\mu}V$ and $552.4{\pm}132.7{\mu}V$, respectively. 3. In T waves, Amplitudes of the positive type showed a frequency of 60.2%, 46.9% and 83.7% in leads of $CV_6LL$, $CV_6RU$ and $CV_6RL$ that were respectively $184.7{\pm}93.7{\mu}V$ $103.7{\pm}64.43{\mu}V$ and $111.8{\pm}39.3{\mu}V$, the negative type showed a frequency of 62.2% and 93.7% in leads $CV_6LU$ and $V_{10}$ that were $142.2{\pm}82.1{\mu}V$ and $-280.3{\pm}107.2{\mu}V$, respectively. 4. Average amplitude of ST segment were $3.7{\pm}33.1{\mu}V$, $0.9{\pm}23.1{\mu}V$, $10.9{\pm}28.6{\mu}V$, $5.8{\pm}28.3{\mu}V$ and $-34.7{\pm}48.4{\mu}V$ in leads $CV_6LL$, $CV_6RU$, $CV_6RL$, $CV_6LU$ and $V_{10}$ respectively.

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A Review on Treasure No.1167, Unified Silla Buddhist Bell from Uncheon-dong, Cheongju, about Its Form and Conservational Scientific Features (보물 제1167호 청주 운천동 출토 통일신라 범종의 형태와 보존과학적 특성 고찰)

  • Kim, Hyun-jeong;Kim, Su-gi
    • Korean Journal of Heritage: History & Science
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    • v.40
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    • pp.357-386
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    • 2007
  • At present, thirteen Buddhist bells of Unified Silla are known to the world: Six in Korea, five in Japan and two other bells, and three out of them are impossible to make out its original form. Therefore, we divided the form of Unified Silla Buddhist bells based on the ten other bells, and we tried out to prove the manufacturing technology by the comparison of the research material of Uncheon-dong bell and existing research materials of other bells, in other to find their linkage based on the alloy elemental composition. We divided Unified Silla Buddhist bell into two types: Type I has symmetric apsaras and regular patterns on its face and it was made in early Silla period; type II has asymmetric apsaras and irregular pattern arrangement and made in late Silla period. In particular, Uncheon-dong Buddhist bells is very similar to Komyoji[光明寺] temple bell from ninth century in Japan. It is peculiar that the apsaras on Uncheon-dong bell play vertical music instruments that are never seen in Unified Silla Buddhist bell. Most of Unified Silla Buddhist bell are compounded with Cu-Sn or Cu-Sn-Pb system. From eighth and ninth century, bells were cast with even composition of copper, tin and lead, and the bronze alloy ratio was similar to the record in Gogonggi[考工記], Jurye[周禮], a book from ancient China. Particularly, Uncheon-dong bell is in a rare case of Cu-Sn-Pb-As system. As had been rarely used in Unified Silla Buddhist bells, so we presented the relative research materials. As has the same nature as Pb. Because As easily volatilize at high temperature, it is hard to use. But it has its merit of solidity and durability. Pb enhances fluidity and thereby expresses the patterns more distinct; As makes the bell stronger. The result of lead isotope ratio could not exactly reveal a concrete producing center. However, over the analysis of our samples, hereby we suggest Uncheon-dong bell was made of materials from just one ore deposit.

Shielding for Critical Organs and Radiation Exposure Dose Distribution in Patients with High Energy Radiotherapy (고 에너지 방사선치료에서 환자의 피폭선량 분포와 생식선의 차폐)

  • Chu, Sung-Sil;Suh, Chang-Ok;Kim, Gwi-Eon
    • Journal of Radiation Protection and Research
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    • v.27 no.1
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    • pp.1-10
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    • 2002
  • High energy photon beams from medical linear accelerators produce large scattered radiation by various components of the treatment head, collimator and walls or objects in the treatment room including the patient. These scattered radiation do not provide therapeutic dose and are considered a hazard from the radiation safety perspective. Scattered dose of therapeutic high energy radiation beams are contributed significant unwanted dose to the patient. ICRP take the position that a dose of 500mGy may cause abortion at any stage of pregnancy and that radiation detriment to the fetus includes risk of mental retardation with a possible threshold in the dose response relationship around 100 mGy for the gestational period. The ICRP principle of as low as reasonably achievable (ALARA) was recommended for protection of occupation upon the linear no-threshold dose response hypothesis for cancer induction. We suggest this ALARA principle be applied to the fetus and testicle in therapeutic treatment. Radiation dose outside a photon treatment filed is mostly due to scattered photons. This scattered dose is a function of the distance from the beam edge, treatment geometry, primary photon energy, and depth in the patient. The need for effective shielding of the fetus and testicle is reinforced when young patients ate treated with external beam radiation therapy and then shielding designed to reduce the scattered photon dose to normal organs have to considered. Irradiation was performed in phantom using high energy photon beams produced by a Varian 2100C/D medical linear accelerator (Varian Oncology Systems, Palo Alto, CA) located at the Yonsei Cancer Center. The composite phantom used was comprised of a commercially available anthropomorphic Rando phantom (Phantom Laboratory Inc., Salem, YN) and a rectangular solid polystyrene phantom of dimensions $30cm{\times}30cm{\times}20cm$. the anthropomorphic Rando phantom represents an average man made from tissue equivalent materials that is transected into transverse 36 slices of 2.5cm thickness. Photon dose was measured using a Capintec PR-06C ionization chamber with Capintec 192 electrometer (Capintec Inc., Ramsey, NJ), TLD( VICTOREEN 5000. LiF) and film dosimetry V-Omat, Kodak). In case of fetus, the dosimeter was placed at a depth of loom in this phantom at 100cm source to axis distance and located centrally 15cm from the inferior edge of the $30cm{\times}30cm^2$ x-ray beam irradiating the Rando phantom chest wall. A acryl bridge of size $40cm{\times}40cm^2$ and a clear space of about 20 cm was fabricated and placed on top of the rectangular polystyrene phantom representing the abdomen of the patient. The leaf pot for testicle shielding was made as various shape, sizes, thickness and supporting stand. The scattered photon with and without shielding were measured at the representative position of the fetus and testicle. Measurement of radiation scattered dose outside fields and critical organs, like fetus position and testicle region, from chest or pelvic irradiation by large fie]d of high energy radiation beam was performed using an ionization chamber and film dosimetry. The scattered doses outside field were measured 5 - 10% of maximum doses in fields and exponentially decrease from field margins. The scattered photon dose received the fetus and testicle from thorax field irradiation was measured about 1 mGy/Gy of photon treatment dose. Shielding construction to reduce this scattered dose was investigated using lead sheet and blocks. Lead pot shield for testicle reduced the scatter dose under 10 mGy when photon beam of 60 Gy was irradiated in abdomen region. The scattered photon dose is reduced when the lead shield was used while the no significant reduction of scattered photon dose was observed and 2-3 mm lead sheets refuted the skin dose under 80% and almost electron contamination. The results indicate that it was possible to improve shielding to reduce scattered photon for fetus and testicle when a young patients were treated with a high energy photon beam.

The Relation between Obesity and Glomerular Filtration Rate in Children and Adolescents (소아 및 청소년에서 비만과 사구체여과율과의 관계)

  • Jung, Youngsu;Kim, Dongwoon;Lim, Inseok
    • Clinical and Experimental Pediatrics
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    • v.48 no.11
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    • pp.1219-1224
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    • 2005
  • Purpose : The prevalence of obesity in children and adolescents has been rising rapidly in Korea because of changes of diet and lifestyle. As with adults, obesity in children and adolescents can cause diabetes mellitus, hyperlipidemia, cardiovascular diseases and renal diseases. The aim of the present study is to examine the relation of obesity, glomerular filtration rate(GFR) and serum cystatin C concentration in children and adolescents. Methods : Data of 115 children and adolescents aged between 6 years and 20 years without clinical evidence of renal diseases were included in the study. From May 2004 to December 2004, blood samples were collected from children and adolescents who were seen at the Department of Pediatrics at Chungang University Yongsan Hospital. Obesity degrees and body mass indices(BMI) were measured, and GFRs were estimated from Schwartz's formula. Serum cystatin C was measured by particle enhanced nephelometric immunoassay using Behring Nephelometer II. Results : GFRs were significantly different between the obese group(BMI >95 percentile, $145.79{\pm}23.10mL/min$) and the non-obese group(BMI <95 percentile, $134.61{\pm}26.19mL/min$) divided by BMI (P=0.031). GFRs were not significantly different between the obese group(obesity degree >120 percent, $144.29{\pm}23.08mL/min$) and the non-obese group(obesity degree <120 percent, $134.54{\pm}26.57mL/min$) divided by obesity degree(P=0.051), but were significantly different between severe obese group (obesity degree >150 percent, $155.55{\pm}20.40mL/min$) and the non-obese group(P=0.004). GFRs were correlated positively with BMI($r^2=0.037$, P=0.039), but were not correlated significantly with obesity degree($r^2=0.030$, P=0.066). Serum cystatin C concentrations were not significantly different between the obese group and the non-obese group, divided by BMI as well as by obesity degree(P>0.05). Conclusion : Obesity may lead to an alteration of renal hemodynamics such as hyperfiltration, appropriate control and management for obesity is necessary.

A Survey on the Hazardous Substances in Agricultural Products of Baggage by Incheon Port (인천항으로 반입되는 휴대농산물에 대한 유해물질 조사)

  • Kim, Ji-Hyeung;Cho, Nam-Gue;Lee, Gue-Sung;Joo, Gwang-Sig;Lee, Han-Jung;Hwang, Eui-Hwa;Go, Jong-Myoung;Kim, Yong-Hee
    • Journal of environmental and Sanitary engineering
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    • v.22 no.3
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    • pp.1-12
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    • 2007
  • This study was investigated hazardous substances in agricultural products of baggage by Incheon Port from chinese. We tested 293 kinds of dried red pepper, cereal, sesame, bean, nut, herbal medicine and sesame oil for pesticides residue, mold, tar color, sudan I, II, III, IV, aflatoxin, Pb, Cd, Hg, As and sulfur dioxide residues. Violated samples over standard limits by Korean Food and Drug Administration (KFDA) were 76 dried red pepper over the number of mold and 1 dried red pepper detected red 102 tar color and 1 dried red pepper over the number of mold and detected red 102 tar color simultaneously. And 2 rice, 1 sticky rice, 1 adlay and 1 millet were over lead. Violated herbal medicine were 2 Zizyphi Furctus and 2 Zingiberis Rhizoma over sulfur dioxide residue and 1 Zingiberis Rhizoma over sulfur dioxide residue and cadmium simultaneously. The contents of heavy metals in cereal were as follow; $Pb\;0.000{\sim}0.740mg/kg(0.191{\pm}0.209),\;Cd\;0.000{\sim}0.108mg/kg(0.007{\pm}0.020),\;Hg\;0.000{\sim}4.201mg/kg(0.162{\pm}0.319)$. The contents of heavy metals in herbal medicine were as follow; $Pb\;0.000{\sim}2.480mg/kg(1.130{\pm}0.730),\;Cd\;0.000{\sim}0.761mg/kg(0.044{\pm}0.122),\;Hg\;0.000{\sim}0.157mg/kg(0.022{\pm}0.033),\;As\;0.000{\sim}0.560mg/kg(0.040{\pm}0.082)$. Contents of $SO_2$ ranged $2.0{\sim}1459.4ppm(303.1{\pm}324.2)$.

Biodiversity and Characteristic Communities Structure of Freshwater Ecosystems in the Western Area of DMZ, Korea (민통선이북지역(DMZ) 서부평야 일대의 수생태계 생물다양성 및 군집 특성)

  • Jung, Sang-Woo;Kim, Yoon-Ho;Kim, Hyun-Mac;Kim, Su-Hwan
    • Korean Journal of Environment and Ecology
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    • v.32 no.6
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    • pp.603-617
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    • 2018
  • This study surveyed the diversity and community characteristics of benthic macroinvertebrates and freshwater fish, which are the main animal classifications in a hydro ecosystem, from May to September 2017 in the western plains of the Demilitarized Zone (DMZ). The results showed a total of 125 species of benthic macroinvertebrates belonging to 66 families, 19 orders, and four phyla in the streams and wetlands. Among benthic macroinvertebrates, Coleoptera (27 spp.: 21.60%) was the largest group in terms of species richness followed by Odonata (26 spp.: 20.80%), non-Insecta (22 spp.: 17.60%), and Hemiptera (11 spp.: 8.80%) occupying in the lentic area. Of the feeding function groups (FFGs), predators (51 spp.: 56.67%) showed a relatively larger presence, indicating the dominance of hygrophilous invertebrates that usually inhabit the freshwater wetlands or ponds. Of the habitat oriented groups (HOGs), climbers (33 spp.: 24.44%) and burrowers (17 spp.: 12.59%) were the dominant groups. This observation is typical in a slow flowing habitat and can lead to the disturbance of the ecosystem due to cannibalism among predators. Cannibalism can be caused by stress induced by various population and environmental factors. For the ecosystem services benchmark (ESB) value, site 13 appeared to be the highest with 82 marks while other sites showed relatively lower rates and indices (III water quality class with ${\alpha}$-mesosaprobic). The analysis result of stability factors showed that almost all sites were evaluated to be the I characteristic group with high resilience and resistance or the III characteristic group that was sensitive to environmental disturbance and formed uneven and unstable communities. Of the freshwater fishes, 46 species (3,405 individuals) belonging to 39 families and 18 orders were identified in all the investigated sites. Among them, Cyprinidae (30 spp.: 65.2%) was the largest group, and Zacco koreanus was identified as the dominant species (728 individuals, 21.4%). The survey of freshwater fish communities found both stable communities (sites 7 and 13) with low dominant index (0.39) and high diversity index (2.29) and unstable communities (sites 2, 3, 8, and 10) in opposite tendency. This survey found five Korean endemic species, 17 species belonging to the export controlled species, two endangered species level II (Lethocerus deyrollei and Cybister chinensis), and rare species (Dytiscus marginalis czerskii) among benthic macroinvertebrates. The survey also found an invasive species, Ampullarius insularus, which was distributed throughout the whole area and thus can continuously disturb the ecosystem in the western plain area in the DMZ. Of freshwater fish, one natural monument (Hemibarbus mylodon) and three endangered species level II (Acheilognathus signifer, Gobiobotia macrocephalus, and G. brevibarba) were observed. The survey also found four introduced species (Pomacea canaliculate, Carassius cuvieri, Lepomis macrochirus, Micropterus salmoides) in the western DMZ area, indicating the need for the protection and conservation measures.

A cohort study on blood zinc protoporphyrin concentration of workers in storage battery factory (축전지 공장 근로자들의 혈중 Zinc Protoporphyrin에 대한 코호트 연구)

  • Jeon, Man-Joong;Lee, Joong-Jeong;SaKong, Joon;Kim, Chang-Yoon;Kim, Jung-Man;Chung, Jong-Hak
    • Journal of Preventive Medicine and Public Health
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    • v.31 no.1 s.60
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    • pp.112-126
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    • 1998
  • To investigate the effectiveness of the interventions in working environment and personal hygiene for the occupational exposure to the lead, the blood zinc protoporphyrin (ZPP) concentrations of 131 workers (100 exposed subjects and 31 controls) of a newly established battery factory were analyzed. They were measured in every 3 months up to 18 months. Ai. lead concentration (Pb-A) of the workplaces was also checked for 3 times in 6 months interval from August 1987. Environmental intervention included the local exhaust ventilation and vacuum cleaning of the floor. Intervention of the personal hygiene included the daily change of clothes, compulsory shower after work and hand washing before meal, prohibition of cigarette smoking and food consumption at the work site and wearing mask. Mean blood ZPP concentration of the controls was $16.45{\pm}4.83{\mu}g/d\ell$ at the preemployment examination and slightly increased to $17.77{\pm}5.59{\mu}g/d\ell$ after 6 months. Mean blood ZPP concentration of the exposed subjects who were employed before the factory was in operation (Group A) was $17.36{\pm}5.20{\mu}g/d\ell$ on employment and it was increased to $23.00{\pm}13.06{\mu}g/d\ell$ after 3 months. The blood ZPP concentration was increased to $27.25{\pm}6.40{\mu}g/d\ell$ on 6 months (p<0.01) after the employment which was 1 month after the initiation of intervention program. It did not increase thereafter and ranged between $25.48{\mu}g/d\ell$ and $26.61{\mu}g/d\ell$ in the subsequent 4 results. Mean blood ZPP concentration of the exposed subjects who were employed after the factory had been in operation but before the intervention program was initiated (Group B) was $14.34{\pm}6.10{\mu}g/d\ell$ on employment and it was increased to $28.97{\pm}7.14{\mu}g/d\ell$ (p<0.01) in 3 months later(1 month after the intervention). The values of subsequent 4 tests were maintained between $26.96{\mu}g/d\ell$and $27.96{\mu}g/d\ell$. Mean blood ZPP concentration of the exposed subjects who were employed after intervention program had been started (Group C) was$21.34{\pm}5.25{\mu}g/d\ell$ on employment and it was gradually increased to $23.37{\pm}3.86{\mu}g/d\ell$ (p<0.01) after 3 months, $23.93{\pm}3.64{\mu}g/d\ell$ after 6 months, $25.50{\pm}3.01{\mu}g/d\ell$ after 9 months, and $25.50{\pm}3.10{\mu}g/d\ell$ after 12 months. Workplaces were classified into 4 parts according to Pb-A. The Pb-A of part I, the highest areas, were $0.365mg/m^3$, and after the intervention the levels were decreased to $0.216mg/m^3$ and$0.208mg/m^3$ in follow-up test. The Pb-A of part II which was resulted in lowe. value than part I was decreased from $0.232mg/m^3$ to $0.148mg/m^3$, and $0.120mg/m^3$ after the intervention. The Pb-A of part III was tested after the intervention and resulted in $0.124mg/m^3$ in January 1988 and $0.181mg/m^3$ in August 1988. The Pb-A of part IV was also tested after the intervention and resulted in $0.110mg/m^3$ in August 1988. There was no consistent relationship between Pb-A and blood ZPP concentration. The blood ZPP concentration of the group A and B workers in the part of the highest Pb-A were lower than those of the workers in the parts of lower Pb-A. The blood ZPP concentration of the workers in the part of the lowest Pb-A increased more rapidly. The blood ZPP concentration of the group C workers was the highest in part III. These findings suggest that the intervention in personal hygiene is more effective than environmental intervention, and it should be carried out from the first day of employment and to both the exposed subjects, blue color workers and the controls, white color workers.

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The embryological studies on the interspecific hybrid of ginseng plant (Panax ginseng x P. Quiuquefolium) with special references to the seed abortion (인삼의 종간잡종 Panax ginseng x P Quinquefoilium의 발생학적 연구 특히 결실불능의 원인에 관하여)

  • Jong-Kyu Hwang
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.5 no.1
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    • pp.69-86
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    • 1969
  • On the growing of the interspecific hybrid ginseng plant, the phenomena of hybrid vigoures are observed in the root, stem, and leaf, but it can not produce seeds favorably since the ovary is abortive in most cases in interspecific hybrid plants. The present investigation was undertaken in an attempt to elucidate the embryological dses of the seed failure in the interspecific hybrid of ginseng (Panax Ginseng ${\times}$ P. Quinque folium). And the results obtained may be summarized as follows. 1). The vegetative growth of the interspecific hybrid ginseng plant is normal or rather vigorous, but the generative growth is extremely obstructed. 2). Even though the generative growth is interrupted the normal development of ovary tissue of flower can be shown until the stage prior to meiosis. 3). The division of the male gameto-genetic cell and the female gameto-genetic cell are exceedingly irregular and some of them are constricted prior to meiosis. 4). At meiosis in the microspore mother cell of the interspecific hybrid, abnormal division is observed in that the univalent chromosome and chromosome bridge occure. And in most cases, metaphasic configuration is principally presented as 23 II+2I, though rarely 22II+4I is also found. 5). Through the process of microspore and pollen formation of F1, the various developmental phases occur even in an anther loclus. 6). Macro, micro and empty pollen grains occur and the functional pollen is very rare. 7). After the megaspore mother cell stage, the rate of ovule development is, on the whole, delayed but the ovary wall enlargement is nearly normal. 8). Degenerating phenomena of ovules occur from the megaspore mother cell stage to 8-nucleate embryo sac stage, and their beginning time of constricting shape is variously different. 9). The megaspore arrangement in the parent is principally of the linear type, though rarely the intermediate type is also observed, whereas various types, viz, linear, intermediate, Tshape, and I shape can be observed in hybrid. 10). After meiosis, three or five megaspore are some times counted. 11). Charazal end megaspore is generally functional in the parents, whereas, in F1, very rarely one of the center megaspores (the second of the third megaspore) grows as an embryo sac mother cell. 12). In accordance with the extent of irregularity or abnormality in meiosis, division of embryo sac nuclei and embryo sac formation cause more nucellus tissue to remain within th, embryo sac. 13). Even if one reached the stage of embryo sac formation, the embryo sac nuclei are always precarious and they can not be disposed to theil proper, respective position. 14). Within the embryo sac, which is lacking the endospermcell, the 4-celled proembryo, linear arrangement, is observed. 15). Through the above respects, the cause of sterile or seed failure of interspecific hybrid would be presumably as follows, By interspecific crossing gene reassortments takes place and the gene system influences the metabolism by the interference of certain enzyme as media. In the F1 plant, the quantity and quality of chemicals produced by the enzyme system and reaction system are entirely different from the case of the parents. Generally, in order to grow, form, and develop naw parts it is necessary to change the materials and energy with reasonable balance, whereas in the F1 plant the metabolic process becomes abnormal or irregular because of the breakdown of the balancing. Thus the changing of the gene-reaction system causes the alteration of the environmental condition of the gameto-genetic cells in the anther and ovule; the produced chemicals cause changes of oxidatio-reduction potential, PH value, protein denaturation and the polarity, etc. Then, the abnormal tissue growing in the ovule and emdryo sac, inhibition of normal development and storage of some chemicals, especially inhibitor, finally lead to sterility or seed failure. Inconclusion, we may presume that the first cause of sterile or seed abortion in interspecific hybrids is the gene reassortment, and the second is the irregularity of the metabolic system, storage of chemicals, especially inhibitor, the growth of abnormal tissue and the change of the polarity etc, and they finally lead to sexual defect, sterility and seed failure.

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