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Recent Progress in Air-Conditioning and Refrigeration Research : A Review of Papers Published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2012 (설비공학 분야의 최근 연구 동향 : 2012년 학회지 논문에 대한 종합적 고찰)

  • Han, Hwataik;Lee, Dae-Young;Kim, Sa Ryang;Kim, Hyun-Jung;Choi, Jong Min;Park, Jun-Seok;Kim, Sumin
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.25 no.6
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    • pp.346-361
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    • 2013
  • This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2012. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. The conclusions are as follows : (1) The research works on thermal and fluid engineering have been reviewed as groups of fluid machinery, pipes and valves, fuel cells and power plants, ground-coupled heat pumps, and general heat and mass transfer systems. Research issues are mainly focused on new and renewable energy systems, such as fuel cells, ocean thermal energy conversion power plants, and ground-coupled heat pump systems. (2) Research works on the heat transfer area have been reviewed in the categories of heat transfer characteristics, pool boiling and condensing heat transfer, and industrial heat exchangers. Researches on heat transfer characteristics included the results for natural convection in a square enclosure with two hot circular cylinders, non-uniform grooved tube considering tube expansion, single-tube annular baffle system, broadcasting LED light with ion wind generator, mechanical property and microstructure of SA213 P92 boiler pipe steel, and flat plate using multiple tripping wires. In the area of pool boiling and condensing heat transfer, researches on the design of a micro-channel heat exchanger for a heat pump, numerical simulation of a heat pump evaporator considering the pressure drop in the distributor and capillary tubes, critical heat flux on a thermoexcel-E enhanced surface, and the performance of a fin-and-tube condenser with non-uniform air distribution and different tube types were actively carried out. In the area of industrial heat exchangers, researches on a plate heat exchanger type dehumidifier, fin-tube heat exchanger, an electric circuit transient analogy model in a vertical closed loop ground heat exchanger, heat transfer characteristics of a double skin window for plant factory, a regenerative heat exchanger depending on its porous structure, and various types of plate heat exchangers were performed. (3) In the field of refrigeration, various studies were executed to improve refrigeration system performance, and to evaluate the applicability of alternative refrigerants and new components. Various topics were presented in the area of refrigeration cycle. Research issues mainly focused on the enhancement of the system performance. In the alternative refrigerant area, studies on CO2, R32/R152a mixture, and R1234yf were performed. Studies on the design and performance analysis of various compressors and evaporator were executed. (4) In building mechanical system research fields, twenty-nine studies were conducted to achieve effective design of mechanical systems, and also to maximize the energy efficiency of buildings. The topics of the studies included heating and cooling, HVAC system, ventilation, renewable energy systems, and lighting systems in buildings. New designs and performance tests using numerical methods and experiments provide useful information and key data, which can improve the energy efficiency of buildings. (5) In the fields of the architectural environment, studies for various purposes, such as indoor environment, building energy, and renewable energy were performed. In particular, building energy-related researches and renewable energy systems have been mainly studied, reflecting interests in global climate change, and efforts to reduce building energy consumption by government and architectural specialists. In addition, many researches have been conducted regarding indoor environments.

Microbiological, physicochemical, and organoleptic evaluation of fresh-cut vegetables irradiated using X-rays (엑스선 조사처리된 신선편의 채소류의 미생물학적, 이화학적, 관능적 품질 평가)

  • Moon, Byeong-Geum;Song, Beom-Seok;Park, Jong-Heum;Kim, Jae-Kyung;Park, Ha-Young;Kim, Dong-Ho;Son, Eun-Joo;Im, Don-Sun;Eun, Jong-Bang
    • Food Science and Preservation
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    • v.24 no.1
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    • pp.27-35
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    • 2017
  • Microbiological, physicochemical, and organoleptic properties of fresh-cut vegetables (FVs), carrots, green peppers, cherry tomatoes, and paprika after X-ray irradiation were evaluated to verify food quality suitable for the immune-depressed patients. Total concentrations of aerobic bacteria in non-irradiated samples, except for cherry tomatoes, were 1.63-3.34 log CFU/g. Irradiation dose exceed 0.4 kGy was used for carrots and green peppers whereas the sterilization dose of 0.2 kGy was used for both cherry tomatoes and paprika. A dose of 0.4 kGy was tentatively determined as the minimum allowable dose for sterilization of the FVs, based on $D_{10}$-values of X-ray irradiation (0.11-0.32 kGy) for Escherichia coli, Listeria monocytogenes, and Salmonella Typhimurium inoculated on the samples. With respect to the physiological properties, only hardness was significantly decreased as the absorbed dose increased; however, there were no significant differences in hardness of the sterilized samples using X-rays at 0.4 kGy compared with those of non-irradiated samples (p<0.05). Moreover, overall acceptance scores of the sterilized FVs were higher than 5.0 points on a 7-point scale, indicating a good organoleptic quality. In a survey on preference of hospitalized patients with cancer (n=50), the average scores for the sterilized FVs, except for carrots, were higher than 4.0 points. In conclusion, it is considered that the FVs, except for carrots, sterilized using X-rays at 0.4 kGy could be served to immune-depressed patients as hygienically safe foods with acceptable organoleptic properties.

Association of β-Catenin with Fat Accumulation in 3T3-L1 Adipocytes and Human Population (β-catenin 유전자의 3T3-L1 지방세포 및 인체에서의 지방축적 연관성 연구)

  • Bae, Sung-Min;Lee, Hae-Yong;Chae, Soo-Ahn;Oh, Dong-Jin;Park, Suk-Won;Yoon, Yoo-Sik
    • Journal of Life Science
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    • v.21 no.9
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    • pp.1301-1309
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    • 2011
  • The major function of adipocytes is to store fat in the form of triglycerides. One of the signaling pathways known to affect adipogenesis, i.e. fat formation, is the WNT/${\beta}$-catenin pathway which inhibits the expression and activity of key regulators of adipogenesis. The purpose of this research is to find genes among the WNT/${\beta}$-catenin pathway which regulate adipogenesis by using small interfering (si) RNA and to find the association of single nucleotide polymorphisms (SNPs) of the gene with serum triglyceride levels in the human population. To elucidate the effects of ${\beta}$-catenin siRNA on adipogenesis key factors, PPAR${\gamma}$ and C/EBP${\alpha}$, we performed real-time PCR and western blotting experiments for the analyses of mRNA and protein levels. It was found that the siRNA-mediated knockdown of ${\beta}$-catenin upregulates adipogenesis key factors. However, upstream regulators of the WNT/${\beta}$-catenin pathway, such as DVL2 and LRP6, had no significant effects compared to ${\beta}$-catenin. These results indicate that ${\beta}$-catenin is a candidate gene for human fat accumulation. In general, serum triglyceride level is a good indicator of fat accumulation in humans. According to statistical analyses of the association between serum triglyceride level and SNPs of ${\beta}$-catenin, -10,288 C>T SNP (rs7630377) in the promoter region was significantly associated with serum triglyceride levels (p<0.05) in 290 Korean subjects. On the other hand, serum cholesterol levels were not significantly associated with SNPs of the ${\beta}$-catenin gene. The results of this study showed that ${\beta}$-catenin is associated with fat accumulation both in vitro and in the human population.

Framework on Soil Quality Indicator Selection and Assessment for the Sustainable Soil Management (지속가능한 토양환경 관리를 위한 토양질 지표의 선정과 평가체계)

  • Ok, Yong-Sik;Yang, Jae-E.;Park, Yong-Ha;Jung, Yeong-Sang;Yoo, Kyung-Yoal;Park, Chol-Soo
    • Journal of Environmental Policy
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    • v.4 no.1
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    • pp.93-111
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    • 2005
  • Defining soil quality in scopes and applications is one of the prerequisite for the sustainable management of soil environment to orient researches, strategies and policies. However, definition of soil quality is controversial depending upon a viewpoint of soil science or soil environment. Soil quality can be, irrespective of the disciplines, defined as the capacity of a soil to function within ecosystem boundaries to sustain biological productivity, maintain environmental quality and promote plant and animal health. Common to all of the soil quality concepts can be summarized as the capacity of soil to function effectively at present and in the future. The OECD includes soil quality as one of the agri-environment indicators. This article intends to i) summarize the current soil quality research, and ii) provide information on protocol of soil quality assessment. A framework for soil quality was divided into three steps: indicator selection as minimum data set (MDS), scoring of the selected indicators, and integration of scores into soil quality index. Korean government suggested possible physical and chemical indicators such as bulk density and organic matter for paddy and upland soils to OECD. The framework of soil quality assessment is not yet implemented in Korea. Countries such as USA, Canada and New Zealand have constructed the framework on soil quality assessment and developed a user-friendly version of soil quality assessment tools to evaluate the integrated effects of various soil management practices. The protocol provided in this review might help policymakers, scientists, and administrators improve awareness about soil quality and understand the way of soil environment management.

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Comparison of Liver, Kidney, Bone Metal Concentration in OhJeokSan-Treated Rats (오적산(五積散)을 투여한 흰쥐의 간장, 신장, 골중 금속농도 비교에 관한 연구)

  • Park Chul-Soo;Lee Sun-Dong;Park Hae-Mo;Park Yeong-Chul
    • Journal of Society of Preventive Korean Medicine
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    • v.6 no.2
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    • pp.66-85
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    • 2002
  • Traditional herbal medicine is used extensively among the Korean populations, and other Asian countries employ similar therapies as well In recent years, extensive focus was laid on adulteration of the herbal medicine with heavy metals. This may be mainly due to a soil contamination by an environmental pollution. The objective of this study is to identify the contents of various heavy metals in the blood from OhJeokSan-Decoction (OD) treated-rats. For this study, 13 kinds of metals including essential and heavy metals, i.e. Al, As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se and Zn were analyzed by a slight modification of EPA methods and the following results are obtained. ; 1. There is no significant difference between the OD-treated groups and control group in liver, kidney, bone, brain, weight, food intake. 2. The amount of each metal analyzed in the liver are as follows; Al ; $0.235{\sim}4.215mg/kg$, As ; $0.103{\sim}0.461mg/kg$, Cd ; $0.005{\sim}0.010mg/kg$, Co ; $0.017{\sim}0.046mg/kg$, Cr ; $0.137{\sim}0.403mg/kg$, Cu ; $1.736{\sim}4.827mg/kg$, Fe ; $54.472{\sim}381.447mg/kg$, Hg ; not detected, Mn ; $1.159{\sim}2.803mg/kg$, Ni ; $0.007{\sim}0.095mg/kg$, Pb ; not detected, Se ; $0.682{\sim}1.887mg/kg$, Zn ; $10.213{\sim}26.119mg/kg$, by groups, respectively. In control and other experimental group, several metal (Co, Cu, Mn, Zn, As, Cr) has a significant difference, but in experimental I and other experimental II, III, IV, V groups, there are no significant difference. 3. The amount of each metal analyzed in the kidney are as follows; Al ; $1.712{\sim}31.230mg/kg$, As ; $0.062{\sim}0.439mg/kg$, Cd ; $0.010{\sim}0.062mg/kg$, Co ; $0.000{\sim}0.101mg/kg$, Cr ; $0.125{\sim}0.636mg/kg$, Cu ; $3.385{\sim}12.502mg/kg$, Fe ; $41.148{\sim}99.709mg/kg$, Hg ; $0.000{\sim}0.270mg/kg$, Mn ; $0.433{\sim}2.301mg/kg$, Ni ; $0.000{\sim}0.221mg/kg$, Pb ; $0.000{\sim}0.584mg/kg$, Se ; $0.540{\sim}1.600mg/kg$, Zn ; $8.775{\sim}17.060mg/kg$, by groups, respectively. The concentration of Cu, Se, Cr, and Hg are variated significantly in control and other experimental group, and Cu, Se, Cd, Cr are variated significantly in experimental I and other experimental II, III, IV, V groups. 4. The amount of each metal analyzed in the bone(tibia and fibula) are as follows; Al ; $9.557{\sim}119.464mg/kg$, As ; $0.139{\sim}12.250mg/kg$, Cd ; $0.000{\sim}0.295mg/kg$, Co ; $0.022{\sim}0.243mg/kg$, Cr ; $0.239{\sim}1.999mg/kg$, Cu ; $0.000{\sim}2.291mg/kg$, Fe ; $240.249{\sim}841.956mg/kg$, Hg ; $0.000{\sim}0.983mg/kg$, Mn ; $0.214{\sim}7.353mg/kg$, Ni ; $5.473{\sim}11.453mg/kg$, Pb ; $0.000{\sim}8.502mg/kg$, Se ; $0.000{\sim}3.005mg/kg$, Zn ; $61.158{\sim}195.038mg/kg$, by groups, respectively. The concentration of Se, Cd are variated significantly in control and other experimental groups, and Se is variated significantly in experimental I and other experimental II, III, IV, V groups. 5. Exceptionally several metal concentration is increased or decreased. but there is no significant harmful difference of metal concentration in the liver, kidney and bone, from the OD-treated-rats compared to those of the control group even if higher dosage($1{\sim}8$ times dosage of person) of OD was administered. Thus, it is expected that the herbal decoction in the traditional herbal medicine would not lay any burden on the body and the heavy metal toxins would not affect our physiological system. However, other kinds of herbal treatment, such as i.v. and i.p. should be considered in terms of metal toxicity in the body since the level of certain metal.

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Principle and Recent Advances of Neuroactivation Study (신경 활성화 연구의 원리와 최근 동향)

  • Kang, Eun-Joo
    • Nuclear Medicine and Molecular Imaging
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    • v.41 no.2
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    • pp.172-180
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    • 2007
  • Among the nuclear medicine imaging methods available today, $H_2^{15}O-PET$ is most widely used by cognitive neuroscientists to examine regional brain function via the measurement of regional cerebral blood flow (rCBF). The short half-life of the radioactively labeled probe, $^{15}O$, often allows repeated measures from the same subjects in many different task conditions. $H_2^{15}O-$ PET, however, has technical limitations relative to other methods of functional neuroimaging, e.g., fMRI, including relatively poor time and spatial resolutions, and, frequently, insufficient statistical power for analysis of individual subjects. However, recent technical developments, such as the 3-D acquisition method provide relatively good image quality with a smaller radioactive dosage, which in turn results in more PET scans from each individual, thus providing sufficient statistical power for the analysis of individual subject's data. Furthermore, the noise free scanner environment $H_2^{15}O$ PET, along with discrete acquisition of data for each task condition, are important advantages of PET over other functional imaging methods regarding studying state-dependent changes in brain activity. This review presents both the limitations and advantages of $^{15}O-PET$, and outlines the design of efficient PET protocols, using examples of recent PET studies both in the normal healthy population, and in the clinical population.

Antimicrobial and Hemolytic Activity of Oriental Medicinal Herbs (한약재의 항균 활성 및 인간 적혈구 용혈 활성)

  • Ryu, Hee-Young;Ahn, Seon-Mi;Shin, Yong-Kyu;Sohn, Ho-Yong
    • Microbiology and Biotechnology Letters
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    • v.38 no.2
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    • pp.190-197
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    • 2010
  • To develop the safe and natural antimicrobial agents, the 68 ethanol extracts from the 61 different kinds of oriental herbal medicine were prepared and their antimicrobial activities were evaluated. The herbal medicine used were from China (46 kinds), South Korea (14 kinds), North Korea (5 kinds) and Vietnam (3 kinds), respectively, and the root (27 species) was popular part in this study. The average water content and extraction ratio for ethanol were 7.10% and 6.75%, respectively. Determination of antimicrobial activity by disc-diffusion assay at 0.5 mg/disc concentration showed that the extract of Angelica tenuissima Nakai (china), Illicium verum, Junci medulla, Rhus javanica L., Salvia miltiorrhiza Bunge and Syzygium aromaticum has strong antimicrobial activities against different food spoilage and pathogenic bacteria and fungi. Determination of MIC and MBC/MFC further showed that the extract of Syzygium aromaticum has MIC of 1.25 mg/mL and MBC/MFC of 1.25~5.00 mg/mL against Listeria monocytogenes, Bacillus subtilis, Staphylococcus epidermidis, Staphylococcus aureus, Salmonella typhimurium, Proteus vulgaris, Escherichia coli, Pseudomonas aeruginosa, Candida albicans and Saccharomyces cerevisiae. And, the extract of Junci medulla, Rhus javanica L. and Salvia miltiorrhiza Bunge showed strong antibacterial activities with MIC of 0.08~0.63 mg/mL and MBC/MFC of 0.08~2.50 mg/mL against the tested bacteria except E. coli and P. aeruginosa. In a while, the results of hemolytic activity of 68 different herbal extracts against human red blood cells showed that the extract of Angelica tenuissima Nakai has hemolytic activity at 0.5 mg/mL concentration. Therefore, Illicium verum, Junci medulla, Rhus javanica L., Salvia miltiorrhiza Bunge and Syzygium aromaticum were finally selected for natural antimicrobial resources. Further research on active substances and the mode of action of the selected herbal medicine is necessary.

Community Structure of Macrobenthic Fauna in the Hallyeohaesang National Park from Korea Strait, Korea (한려해상국립공원 조하대 해역 대형저서동물의 군집구조)

  • Yoon, Kon-Tak;Seo, In-Soo;Kim, Kwang-Bong;Cho, Byoung-Mi;Son, Min-Ho
    • Korean Journal of Environmental Biology
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    • v.27 no.1
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    • pp.124-133
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    • 2009
  • The study was performed to investigate the community structure of macrobenthic fauna during June 2005, in Hallyeohaesang National Park from Korea Strait. A total of 284 macrobenthic fauna were collected. The overall average macrobenthic density and biomass were 2,002 individuals m$^{-2}$ and 154.92 gWWt m$^{-2}$, respectively. Based on the Lebris (1988) index, there were 20 species accounting for approximately 47.64% of total individuals. And the highest densities were found in the polychaetes Scoletoma longifolia, Isolda pulchella, Mediomastus californiensis, Minuspio multibranchia, Tharyx sp. 1 and the bivalve Theora fragilis. On the other hand, the top twenty species made up 70.47% of the total biomass while the three most abundant, the echinoderms Schizaster lacunosus, Amphiura vadicola and the bivalve Fulvia mutica. The conventional multivariate statistics (cluster analysis and non-metric Multi-Dimensional Scaling) applied to assess spatial variation in macrobenthic assemblages. As a result of cluster analysis and nMDS ordination, this study area was divided into two different groups of stations and species. In case of station, there are two groups: one is a mud dominated station group and the other is dead shell and sand dominated group. And the 2 faunistic groups were established as follows: 1) a group of relatively higher abundances in mud dominated sediment. There were numerically dominated by the polychaetes Magelona japonica, Sternaspis scutata, Paraprionospio pinnata, Tharyx sp. 1 and the amphipods Monocorophium sinense and Eriopisella sechellensis. 2) a group of relatively higher densities dead shell and sand dominated sediment. These groups were characterized by the polychaetes I. pulchella, M. multibranchiata, the amphipods M. acherusicum, Gammaropsis japonicus and the echinoderm A. vadicola.

Intraluminal High-Dose-Rate Brachytherapy for the Tumors of Gastrointestinal Tract (위장관 종양의 고선량율 강내 방사선치료)

  • Choi Byung Ock;Choi Ihl Bhong;Chung Su Mi;Kim In Ah;Choi Myoung Gyu;Chang Suk Kyun;Shinn Kyeong Sub
    • Radiation Oncology Journal
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    • v.13 no.3
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    • pp.243-252
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    • 1995
  • Purpose : Intraluminal high dose rate brachytherapy is an accepted treatment for the tumors of GI tract. However, there is only some limited clinical data for intraluminal high dose rate brachytherapy for the tumors of GI tract. Materials and Methods : Between February 1991 and July 1993, 18 Patients who have the tumors of GI tract (esophageal cancer-8 cases, rectal cancer-10 cases) were treated with high dose rate Iridium-192 afterloading system (Microselectron-HDR, Nucletron CO, Netherland) at the department of therapeutic radiology, St. Mary's hospital, Catholic university medical college. Age range was 47-87 years with a mean a9e 71 years. All patients were treated with intraluminal high dose rate brachytherapy within two weeks after conventional external radiation therapy and received 3-5 Gy/fraction 3-4 times per week to a total dose 12-20 Gy (mean 17 Gy). Standard fractionation and conventional dose were delivered for external radiation therapy. Total dose of external radiation therapy ranged 41.4-59.4 Gy (mean 49.6 Gy). Median follow up was 19 months Results : The analysis was based on 18 patients, The complete response and partial response in esophageal cancer was similar (38%). Two year rates for survival and median survival were 13% and 10 months, respectively. Among 10 patients of rectal cancers, partial response was obtained in 6 patients (60%). There was no complete response in the patients with rectal cancer, but good palliative results were achieved in all patients. Conclusion : Although the number of patients was not large and the follow-up period was relatively short, these findings suggested that intraluminal high dose rate brachytherapy could be useful in the treatment of the patients with advanced tumors of GI tract.

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An Epidemiologic Study on Death Caused by Cancer in Pusan (부산지역의 암 사망에 관한 역학적 연구)

  • Kim, Hwi-Dong;Koo, Hye-Won;Kwak, Moon-Suk;Kim, Jong-Ryul;Son, Byung-Chul;Moon, Deog-Hwan;Lee, Jong-Tae;Cho, Kyu-Il;Ohm, Sang-Hwa;Jung, Kui-Oak;Chun, Jin-Ho;Lee, Chae-Un
    • Journal of Preventive Medicine and Public Health
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    • v.29 no.4 s.55
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    • pp.765-783
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    • 1996
  • This study surveyed and measured the level and structure of cancer deaths and their trends over time for offering the fundamental data of e cancer prevention and control in Pusan city in the future. Authors conducted the study of descriptive epidemiology using materials derived from the computerized data of total 3,722 certified cancer deaths in Pusan city from January 1 to December 31, 1993 registered on the National Statistical Once, the Republic of Korea. The obtained results were as follows: 1. According to the total registered cases of deaths(16,331 cases) in Pusan city during 1993, cancer(3,722 cases) and cerebrovascular disease(2,118 cases) were the first and second cause of deaths as 23.1% and 16.9%, respectively. These pattern showed the change between cancer (14.7%) and cerebrovascular disease(18.5%) in order of frequency in comparison to 1982. Also, the total number of cancer deaths was increased in comparison to 1982. The rate of death certification by physicians was 87.1% of all registered deaths, which was increased to 6.8% in comparison to 1982(80.3%). 2. Crude death rate and cancer specific death rate was 4.06 per 1,000 populations and 93.8 per 100,000 populations(male:117.8, female:70.0), respectively. The former was similar to that of 1982, but the latter was increased to 1.6 times as that of 1982. 3. Age-adjusted cancer specific death rate by standardization with whole country population was 111.9(male:141.5, female:106.7) per 100,000 populations, higher than not age-adjusted cancer specific death rate(93.8), and the sex difference was statistically significant with male predominance (p<0.05). 4. Cancer specific death rate by age was generally increased with age and most of cancer deaths(male:91.8%, female:88.5%) occurred since 40 years old. 5. The major cancer(cancer specific death rate per 100,000 populations) in male was liver(30.6) followed by stomach(25.6), lung(21.9), and GB and EHBD(5.7), in female stomach(15.7), liver(9.9), lung(7.3), and uterus(6.9). The relative frequency of the leading three cancer among total cancer deaths marked 66.3% in male and 47.l% in female, and decreased in comparison to 1982(male:72.2%, female:54.5%). 6. The total ratio of male to female cancer specific death rate showed 1.68 to 1 with male predominance. And the ratio was above 2.0 in larynx, oral cavity & pharynx, esophagus, liver, lung, bladder cancer and the ratio was $1.0\sim1.9$ in stomach, pancreas, gall bladder and EHBD, brain, rectum and anus cancer, leukemia, but the ratio was reversed in thyroid and colon cancer. In conclusion, cancer was the first cause of deaths. The proportion of lung cancer was increased, that of stomach & uterine cancer was decreased relatively, and liver cancer was constantly higher proportion. In the future, it is necessary to conduct the further investigations on the cancer risk factors considering areal specificity.

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