Bioaerosols, airborne particles of biological origin, are omnipresent in the common surroundings of humans. In antimicrobial filter system, as particles or organic materials are deposited on the filter surface, the bacteria come into contact with the antimicrobial material less, and thus they can easily grow on particles or organic materials. We selected a carbon fiber ionizer which generated air ions as antimicrobial agent. Antimicrobial effect of carbon fiber ionizer on the outlet air and condensate water was tested using application of carbon fiber ionizer in a small-scale commercial air conditioner. In conclusion, the application of carbon fiber ionizer in the air conditioner showed more increasing antimicrobial efficiency.

The aim of the present study was to investigate the cleavage pattern, its developmental ability and apoptosis of porcine embryo in vitro. Morphology data on a total of 919 embryos were analyzed retrospectively. Forty-eight hours after insemination, embryos were classified into five groups based on the cleavage state as follows; 1 cell, 2 cell, 4 cell, 5 to 8 cell and fragmentation. These groups were cultured another 120 hours and then evaluated for blastocyst formation. Blastocyst formation rates were significantly higher in 4 cell (42.5%) and 5 to 8 cell (48.6%) cleaving groups than in other groups (p<0.05). On the other hand, 2 cell and fragmentation groups produced 4.9% and 3,9% blastocysts, respectively. And we could verify that in the event of 2 cell block and fragmentation of embryo. To analyze the apoptotic frequency in preimplantation development of porcine IVF embryos, all cells of each blastocyst were performed by TUNEL assay. There were no significantly differences in the total cell numbers of embryos and apoptotic cell rate in blastocysts among the each classified groups. Data suggest that 4 cell and 5 to 8 cell cleaving embryos at 48 hour after insemination have high developmental competence, and may be an useful parameter to predict the development of preimplantation embryos and to study using preimplanation embryonic research.

Characteristics of commercial antimicrobial filter media for bioaerosol removal were estimated. A chitoasn/ medium filter, a catechin/HEPA filter, a silver/HEPA filter, a copper/pre filter, a electret cabin filter and a non-electret cabin filter were used for estimation. Filtration efficiency and antimicrobial efficiency was tested using Escherichia coli and Staphylococcus epidermidis. The electret cabin filter and the chitosan/medium filter showed the highest filtration and antimicrobial efficiency, respectively.

Bioaerosols are airborne particles of biological origins including viruses, bacteria, fungi, and all varieties of living materials. In suitable hosts, bioaerosols are capable of causing acute or chornic diseases that may be infectious, allergenic, or toxigenic. Bioaerosols from outdoor air accumulate on filters of heating, ventilating and air conditioning (HVAC) system in large quantities and are able to multiply there under certain conditions. In this study, silver was coated on activated carbon fiber (ACF) filters by an electroless plating method, and their efficacy for bioaerosols removal was tested. Physical filtration and biological antimicrobial test were performed. SEM and XRD analyses were used to characterize the morphology and components of ACF filters. Electroless silver-plated ACF filters showed antimicrobial efficiency, whereas pure ACF filters did not. It was found that electroless silver plating did not influence the physical filtration efficiency of ACF filters.

본 연구는 소 형질 전환 체세포 핵이식에서 용이한 탈핵을 위해 demecolcine을 이용할 시 탈핵율과 핵이식란의 발육능을 높이기 위한 최적의 조건을 알아보고자 실시되었다. 도축장 유래 미성숙 난자를 18시간 체외성숙 후 제1극체가 확인된 성숙 난자를 0.1, 0.2, 0.4 및 0.8 ug/ml의 demecolcine이 첨가된 배지에서 1시간 더 처리한 다음 세포막이 돌출되어 있는 난자를 체세포 핵이식에 공여하여 각 군간 배반포로의 발육능을 비교하였

본 연구는 개 동결 정액 융해 시 straw 크기 및 융해 속도가 융해 정자의 질(quality)에 미치는 영향을 조사하고 최적의 융해 조건을 조사하는데 그 목적이 있다. 정상적인 번식능을 가진 비글 수컷 5마리에서 정액을 채취하여 원심 분리하여 정장을 버리고 남은 정자에 동결보호제인 glycerol이 첨가된 tris-glucose-egg yolk extender를 첨가하여 동결하고 액체질소에 보관한 후 융해하였다. 동결 융해 조건에 따른 효과를 알아보

본 연구는 정상 및 저수태 한우에 rbST를 투여하였을 때 수태 및 분만율에 미치는 영향을 조사하기 위하여 수행하였다. 시험축은 성빈 한우 383두와 임상적으로는 정상이나 3회 이상 수정시켜도 수태가 되지 않는 저수태 한우 79두, 총 462두를 시험에 공시하였다. 실험을 수행하기 위한 시험구 배치는 5개의 처리구, 즉 T1(무처리, 2ml의 생리 식염수), T2(rbST 250mg 수정시 1회 미근부에 투여), T3(rbST 250mg: 수정시 및 수

The antimicrobial activity of metallic nanoparticles against bacteria was investigated. Silver, copper, and titania nanoparticles were tested. The bacteria species E. coli and B. subtilis were selected as models for Gram-negative and Gram-positive bacteria, respectively. Bacteriological tests were performed in Luria-Bertani (LB) medium or Nutrient (NT) medium on solid agar plates containing different concentrations of nanoparticles in the range of 0 to 150 μg/mL. Silver and copper nanoparticles were shown to be an effective bactericide. However, titania nanoparticles were found to be ineffective as an antimicrobial agent. It appears that E. coli cells are more sensitive to the copper nanoparticles than to silver nanoparticles and B. subtilis cells have similar sensitivity against both copper and silver nanoparticles.

A ventilation system comprising a dielectric barrier discharger and UV‐TiO2 photocatalyst filters was designed and tested for simultaneous removal of gaseous and particulate contaminants in a test chamber. The DBD was used as the 1st stage of ESP for particle charging and gas decomposition. Charged particles were collected in the 2nd stage of ESP by an applied DC electric field. The UV‐TiO2 photocatalyst filters were used for decomposing gaseous species including O3 which was inherently produced by the DBD. Particle removal efficiencies based on mass and number were approximately 83.0% and 88.8%, respectively, after the ventilation system was operating for 5 hours. HCHO removal efficiency was approximately 100% for 1∼5ppm of upstream concentration condition. TVOC removal efficiency was 99.0% and 99.6% for 1 ppm and 5 ppm of upstream concentration conditions, respectively.

Abstract Dielectric barrier discharge (DBD) in air, which has been established for the production of large quantities of ozone, is more recently being applied to a wider range of aftertreatment processes for HAPs (hazardous air pollutants). Although DBD has high electron density and energy, its potential use as precharging nano and submicron sized particles, is not known. In this work, we measured V‐I (voltage‐current) characteristics of DBD and estimated the collection efficiency of particles with bimodal distribution by DBD type 2‐stage ESP (electrostatic precipitator). To examine the particle collection with various applied voltage waveforms of DBD, nano size particles of NaCl (20∼100 nm) and DOS (50∼800 nm) were generated by an electrical tube furnace and an atomizer, respectively. Particle collection efficiencies of all the cases increased with increase of DBD electric power that the results corresponded to product of V by I whose magnitudes were the largest in triangular voltage waveform.

From September 1993 to August 1997, we treated ovarian disorders in 1,782 repeat breeder cows after diagnosis by ultrasound on 35 farms in Kyeong-ki do. The rates of ovarian appearance were 59.8% of CL group, 16.7% of ovarian atrophy or hypofunction, 15.4% of luteal cyst, 4.3% of follicular cyst and 3.7% of follicle group in diagnosis with rectal palpation and ultrasound. The results of treatment for ovarian disorders were 1,316 cows(73.8%) in estrus, 348 cows(19.5%) in non-detected and 118 cows(6.6%) in unidentified. The rates of PGF, GnRH and mineral vitamin complex treatment to estrus were 79.6, 69.2 and 50.3%. Two groups were treated with 5 ml PGF intramuscular injection(I.M.) and 1.5 ml PGF intraovarian injection(I.O.), and the results of 1.5ml PGF I.0. were significantly higher than that of 5ml PGF I.M. in inductiom estrus(p<0.05). The pregnant rates were 29.8% in total repeat breeder cows with ovarian disorders following diagnosis and treatment. In summary, rectal palpation and ultrasonography were proven to be useful tools of diagnosis and treatment in ovarian disorders, and it was also suggested that the response to treatment with PGF I.0. was better than PGF I.M.

Real time B-mode ultrasound was used to detect the early conceptus in 187 Korean native cattles between days 10 and 60 after last insemination. The ultrasound diagnostic findings were systemically confirmed by palpation per rectum after the 60th day of last insemination. The embryonic vesicle and the embryo proper within the veside were first visible on mean day fl and 23, respectively. The heartbeat of the embryo proper could be detected on day 26, and the limb buds, placentomes, amnion, fetal movement, umbilical cord, optic area and split hooves were first visible on day 33, 34, 34, 44.5, 45, 32 and 48, respectively. The mean length of embryo proper was 3.8mm on day 23 which later increased to 56. 6rnrn on day 60. When ultrasound was used to detect the conceptus between days 20 and 30 after insemination and palpation per rectum after the 60th day of insemination, the accuracy rates of pregnancy detection by ultrasound scanning at days 20, 22, 24, 26, 28, 30 were 44.4, 69.2, 78.6, 87.5, 90.0, 93.3%. In summary, the early pregnancy diagnosis of Korean native cattle with ultrasound appears high accuracy rates. It is considered that ultrasound can be used in veterinary practice well.