• 제목/요약/키워드: $NO_2/NO_x$ ratio

검색결과 545건 처리시간 0.027초

A Study on the Provenance of an Opacifying Agent(PbSnO3) in Yellow and Green Glass Beads Excavated from the Korean Peninsula

  • Yu, Heisun;Ro, Jihyun
    • 보존과학회지
    • /
    • 제34권4호
    • /
    • pp.305-311
    • /
    • 2018
  • The yellow crystalline material present in yellow and green glass beads excavated from sites in the Baekje region of Korea was previously analyzed through scanning electron microscopy with energy dispersive spectroscopy and X-ray diffraction, revealing that the yellow crystalline material was $PbSnO_3$. This material is a pigment that is rarely seen in the Korean peninsula. Furthermore, some studies have been published on the provenance of lead in this material, which revealed no relationship to Korea, China, or Japan. In this study, we collected all accessible results of analyses on the lead isotope ratio of yellow and green glass beads excavated from the Korean peninsula, specifically from 7 sites in the Baekje region(located in the vicinity of Seoul, Wanju, Hwaseong, Osan, Gongju, Buyeo, and Iksan) and 2 sites in the Silla region(located in the vicinity of Gyeongju and Changnyeong). We subsequently investigated the lead provenance of the opacifying agents in the glass beads through comparison with the current extent of the galena data accumulated for the East Asian region, including Korea, China, and Japan, and for Thailand(Kanchanaburi Province), Southeast Asia. Our analysis determined that the lead provenance of the glass beads excavated from the Korean peninsula was Thailand(Kanchanaburi Province). Beyond our results, further studies should seek to determine the production sites of the glass beads. Obtaining and comparing the scientific analyses of glass beads from India and Southeast Asia would enable research on the glass beads trade through the maritime silk road.

Effects of Immune Stress on Performance Parameters, Intestinal Enzyme Activity and mRNA Expression of Intestinal Transporters in Broiler Chickens

  • Feng, Y.;Yang, X.J.;Wang, Y.B.;Li, W.L.;Liu, Y.;Yin, R.Q.;Yao, J.H.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • 제25권5호
    • /
    • pp.701-707
    • /
    • 2012
  • Immune stress is the loss of immune homeostasis caused by external forces. The purpose of this experiment was to investigate the effects of immune stress on the growth performance, small intestinal enzymes and peristalsis rate, and mRNA expression of nutrient transporters in broiler chickens. Four hundred and thirty-two 1-d-old broilers (Cobb500) were randomly assigned to four groups for treatment; each group included nine cages with 12 birds per cage. Group 1 = no vaccine (NV); Group 2 = conventional vaccine (CV); group 3 = lipopolysaccharide (LPS)+conventional vaccine (LPS); group 4 = cyclophosphamide (CYP)+conventional vaccine (CYP). The results demonstrated that immune stress by LPS and CYP reduced body weight gain (BWG), feed intake (FI), small intestine peristalsis rate and sIgA content in small intestinal digesta (p<0.05). However, the feed conversion ratio (FCR) remained unchanged during the feeding period. LPS and CYP increased intestinal enzyme activity, relative expression of SGLT-1, CaBP-D28k and L-FABP mRNAs (p<0.05). LPS and CYP injection had a negative effect on the growth performance of healthy broiler chickens. The present study demonstrated that NV and CV could improve growth performance while enzyme activity in small intestine and relative expression of nutrient transporter mRNA of NV and CV were decreased in the conditions of a controlled rational feeding environment. It is generally recommended that broilers only need to be vaccinated for the diseases to which they might be exposed.

Versatility of the pedicled buccal fat pad flap for the management of oroantral fistula: a retrospective study of 25 cases

  • Park, Jinyoung;Chun, Byung-do;Kim, Uk-Kyu;Choi, Na-Rae;Choi, Hong-Seok;Hwang, Dae-Seok
    • Maxillofacial Plastic and Reconstructive Surgery
    • /
    • 제41권
    • /
    • pp.50.1-50.6
    • /
    • 2019
  • Purpose: Maxillary bone grafts and implantations have increased over recent years despite a lack of maxillary bone quality and quantity. The number of patients referred for oroantral fistula (OAF) due to implant or bone graft failure has increased, and in patients with an oroantral fistula, the pedicled buccal fat pad is viewed as a robust, reliable option. This study was conducted to document the usefulness of buccal fat pad grafts for oroantral fistula closure. Materials and methods: We retrospectively studied 25 patients with OAF treated with a buccal fat pad graft from 2015 to 2018. Sex, age, OAF location, cause, duration, presence of systemic disease, smoking, previous dental surgery, and side effects were investigated. Results: A total of 25 patients were studied. Mean patient age was 54.8 years, and the male to female ratio was 19: 6. Causes of oroantral fistula were cyst enucleation, tumor resection, implant removal, bone graft failure, and extraction. Excellent results were obtained in 23 (92%) of the 25 patients. In the other two patients that both smoked, a small fistula was observed during follow-up. No recurrence of oroantral fistula was observed after 2 months to 1 year of follow-up. Conclusions: The incidence of oroantral fistula is increasing due to implant and bone graft failures. Oroantral fistula closure using a pedicled buccal fat pad was found to have a high success rate.

Comparisons of In vitro Nitrate Reduction, Methanogenesis, and Fermentation Acid Profile among Rumen Bacterial, Protozoal and Fungal Fractions

  • Lin, M.;Schaefer, D.M.;Guo, W.S.;Ren, L.P.;Meng, Q.X.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • 제24권4호
    • /
    • pp.471-478
    • /
    • 2011
  • The objectives were to compare the ability of various rumen microbial fractions to reduce nitrate and to assess the effect of nitrate on in vitro fermentation characteristics. Physical and chemical methods were used to differentiate the rumen microbial population into the following fractions: whole rumen fluid (WRF), protozoa (Pr), bacteria (Ba), and fungi (Fu). The three nitrogen substrate treatments were as follows: no supplemental nitrogen source, nitrate or urea, with the latter two being isonitrogenous additions. The results showed that during 24 h incubation, WRF, Pr and Ba fractions had an ability to reduce nitrate, and the rate of nitrate disappearance for the Pr fraction was similar to the WRF fraction, while the Ba fraction needed an adaptation period of 12 h before rapid nitrate disappearance. The WRF fraction had the greatest methane ($CH_4$) production and the Pr fraction had the greatest prevailing $H_2$ concentration (p<0.05). Compared to the urea treatment, nitrate diminished net gas and $CH_4$ production during incubation (p<0.05), and ammonia-N ($NH_3$-N) concentration (p<0.01). Nitrate also increased acetate, decreased propionate and decreased butyrate molar proportions (p<0.05). The Pr fraction had the highest acetate to propionate ratio (p<0.05). The Pr fraction as well as the Ba fraction appears to have an important role in nitrate reduction. Nitrate did not consistently alter total VFA concentration, but it did shift the VFA profile to higher acetate, lower propionate and lower butyrate molar proportions, consistent with less $CH_4$ production by all microbial fractions.

상악 분절골 후퇴술 후의 상순위치 변화 연구 (A STUDY OF UPPER LIP PROFILE CHANGE AFTER ANTERIOR SEGMENTAL SETBACK OSTEOTOMY)

  • 노광섭;홍종락;김창수
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
    • /
    • 제31권3호
    • /
    • pp.274-278
    • /
    • 2005
  • Purpose : Prediction for soft tissue change after orthognathic surgery is very important for the final esthetics. In this study, we have tried to get the amount of upper lip movement relative to bony segment movement after anterior segmental osteotomy by cephalmetric analysis to predict final upper lip position after surgery. Material and Methods : 20 patients was studied on whom anterior segmental osteotmy as performed by Cupar method during the years 2002 to 2003. Cephalometric radiograph were taken at 1month before surgery and 6 month after surgery. Change of upper lip was measured on landmark Ls and Sto relative to hard tissue (landmark Ia) setback on these X-rays and analyzed. Results : 1. Upper lip setback movement. Setback of upper lip showed proportional relation to the hard tissue setback and the ratio was about 84%(p=0.001). 2. Upper lip downward movement. Downward movement of upper lip showed no proportional relation to hard tissue setback And the amount was mean 1.38 mm and SD 1.21mm (p=0.922). Conclusion : The posterior movement of upper lip is affected by hard tissue movement and shows good proportional change whereas downward movement is not so much influenced by hard tissue movement. And we think slight downward movement shown in this study could be explained by the V-Y closure performed during surgery.

A comparison of different compressive forces on graft materials during alveolar ridge preservation

  • Cho, In-Woo;Park, Jung-Chul;Shin, Hyun-Seung
    • Journal of Periodontal and Implant Science
    • /
    • 제47권1호
    • /
    • pp.51-63
    • /
    • 2017
  • Purpose: Following tooth extraction, alveolar ridge preservation (ARP) can maintain the dimensions of ridge height and width. Although previous studies have demonstrated the effects of ARP, few if any studies have investigated the compressive force applied during grafting. The aim of this study was to determine the effects of different compressive forces on the graft materials during ARP. Methods: After tooth extraction, sockets were filled with deproteinized bovine bone mineral with 10% porcine collagen and covered by a resorbable collagen membrane in a double-layered fashion. The graft materials were compressed using a force of 5 N in the test group (n=12) and a force of 30 N in the control group (n=12). A hidden X suture was performed to secure the graft without primary closure. Cone-beam computed tomography (CBCT) was performed immediately after grafting and 4 months later, just before implant surgery. Tissue samples were retrieved using a trephine bur from the grafted sites during implant surgery for histologic and histomorphometric evaluations. Periotest values (PTVs) were measured to assess the initial stability of the dental implants. Results: Four patients dropped out from the control group and 20 patients finished the study. Both groups healed without any complications. The CBCT measurements showed that the ridge volume was comparably preserved vertically and horizontally in both groups (P>0.05). Histomorphometric analysis demonstrated that the ratio of new bone formation was significantly greater in the test group (P<0.05). The PTVs showed no significant differences between the 2 groups (P>0.05). Conclusions: The application of a greater compressive force on biomaterials during ARP significantly enhanced new bone formation while preserving the horizontal and vertical dimensions of the alveolar ridge. Further studies are required to identity the optimal compressive force for ARP.

Evaluation of calving interval and selection indices in Korean native cows

  • Choi, Inchul;Lee, Dooho;Lee, Jong-Gwan;Lee, Seung-Hwan;Ryoo, Seung-Heui
    • 농업과학연구
    • /
    • 제47권3호
    • /
    • pp.667-672
    • /
    • 2020
  • It is well known that intensive selection caused a decline in reproductive performance in dairy cattle. Interestingly, the reproductive performances including fertility and calving interval of Korean native beef cattle have declined in the last 20 years, suggesting that a breeding program focusing on carcass weight and intramuscular fat may affect the reproductive physiology in Korean native beef cattle, too. In this study, we analyzed the calving interval (CI) and selection index (SI) based on genome-wide association studies (GWAS) of Hanwoo cows for seven years (2013 - 2019). Multiparous cows (4.5 ± 0.11) were analyzed, which were bred by artificial insemination (AI). We first examined the distribution of the AIs and calving dates. About 40% of the AIs were carried out in May to June and October to December; subsequently, calving was observed from March to April and August to October, respectively, indicating the cows were seasonally bred. No correlation between CI and SI was found (y = 0.0459x - 17.64; R2 = 0.0356), but the ratio of cows with a positive SI was higher in the longer CI group compared to the shorter group, suggesting that the selection for meat quality and quantity may affect the reproductive performances. In addition, the average value of SI was - 3.42 in the CI < 400 while + 5.79 in the CI > 400 although the values were not statistically significant. However, our results suggest that reproductive indices such as fertility and CI should be considered for sustainability in the Hanwoo breeding selection program.

Low Muscle Mass and Depressed Mood in Korean Adolescents: a Cross-Sectional Analysis of the Fourth and Fifth Korea National Health and Nutrition Examination Surveys

  • Moon, Ji Hyun;Kong, Mi Hee;Kim, Hyeon Ju
    • Journal of Korean Medical Science
    • /
    • 제33권50호
    • /
    • pp.320.1-320.8
    • /
    • 2018
  • Background: Muscle mass and muscle function are related to depressed mood in studies of adults. Like adults, Korean students are highly likely to suffer from decreased muscle mass due to social conditions. In this study, we evaluated the muscle mass status of Korean adolescents and assess the effect of muscle on depressive mood. Methods: A total of 1,233 adolescent boys and girls participants from the Korea National Health and Nutrition Examination Survey were enrolled in our study. Participants underwent dual-energy X-ray absorptiometry for assessment of appendicular muscle mass and completed questionnaires regarding depressed mood, stress, suicidal ideations, and attempts. Results: There was no difference in depressive mood according to muscle mass among boys (P = 0.634); girls with decreased muscle mass had a greater tendency for depressed mood compared to girls with optimal muscle mass (P = 0.023). After adjusting for age, waist circumference-to-height ratio, smoking status, alcohol consumption, frequency of physical activity, self-reported obesity, weight-loss efforts, and monthly household income, girls with low muscle mass (LMM) were 2.60 times more at risk of developing depression than girls with normal muscle mass (95% confidence interval [CI], 1.05-6.49; P = 0.040). This trend was similar for girls with LMM with obesity (95% CI, 1.00-11.97; P = 0.049). Conclusion: Adolescent girls who have insufficient muscle mass are more likely to report depressed mood than girls who have ideal muscle mass. Interventions for maintaining proper muscle mass are required.

Alveolar cleft bone grafting: factors affecting case prognosis

  • Mahardawi, Basel;Boonsiriseth, Kiatanant;Pairuchvej, Verasak;Wongsirichat, Natthamet
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
    • /
    • 제46권6호
    • /
    • pp.409-416
    • /
    • 2020
  • Objectives: The goal of this retrospective study was to determine the significance and impact of several factors on the alveolar cleft bone grafting procedure. Materials and Methods: The medical records were reviewed. In addition, x-rays were checked. The size of every cleft was measured in this retrospective study. The analyzed factors included sex, age, type of cleft, size of the cleft, and the type of flap used in surgery. The patients were characterized into group A (no complications, Bergland scale 1 or 2), group B (complications or Bergland scale 3), or group C (failure cases). Statistical analysis was performed with a P-value set at 0.05. Results: There were 32 cases in group A, 26 in group B, and 9 in group C. Multinomial logistic regression showed an association between the type of the cleft and the size of the cleft, with the presence of complications, or achieving type 3 on the Bergland scale, with odds ratios of 5.118 and 6.000, respectively. The type of cleft was related to failure with an odds ratio of 4.833. Given a small sample, statistical analysis could not be performed to evaluate the relationship between the size of the cleft and group C. Age, sex, and the type of the flap were not significant factors. Conclusion: The cleft size of more than 10 mm and bilateral clefts were listed regarding their effect on the procedure. Clinicians should not overlook these factors. In addition, patients must be informed of any risks that are present.

한국 제주도산 해가리비 Amusium japonicum japonicum의 생식소 발달, 군성숙도 및 성비 (Gonadal Development, First Sexual Maturity and Sex Ratio of the Sun and Moon Scallop Amusium japonicum japonicum on the Coastal Waters of Jejudo, Korea)

  • 손팔원;정의영
    • 한국발생생물학회지:발생과생식
    • /
    • 제9권2호
    • /
    • pp.95-103
    • /
    • 2005
  • 한국 제주도산 해가리비(Amusium japonicum japonicum)를 대상으로 생식주기, 생식소중량지수(GSI), 난경조성 변화, 군성숙도, 성적 성숙체장(50% 군성숙도) 및 성비를 조직학적 관찰 및 생체 측정에 의해 조사하였다. 해가리비는 자웅이체이다. 생식소 중량지수(GSI)의 월별 변화는 생식주기와 유사한 양상을 보였다. 완숙 난모세포들은 직경이 약 $70{\sim}90\;{\mu}m$ 정도이며, 두터운 난막을 가지는 특징을 가지고 있다. 산란기는 11월부터 1월 사이이며, 주 산란은 해수 수온이 낮은 $11{\sim}12$월 사이에 일어난다. 월별 난경 조성 변화를 보면, 산란기 중 산란빈도 수는 2회 이상으로 추정되지만, 산란기간은 1년에 한번이다. 본 종의 생식주기는 초기 활성기($4{\sim}6$월), 후기 활성기($6{\sim}9$월), 완숙기 ($10{\sim}11$월), 산란기($11{\sim}1$월), 그리고 퇴화 및 휴지기($2{\sim}4$월)의 연속적인 5단계로 나눌 수 있다. 각장 $85.1{\sim}90.0mm$인 암 수의 해가리비 군 성숙도는 50%이었고, 각장 90.0mm 이상인 개체들은 100%이었다. 이 개체군에서 성적으로 성숙한 암 수 개체들의 각장(군 성숙도 50%) 크기는 각각 86.96mm와 86.59mm이었다. 각장 85.1mm 이상인 암 수 개체들의 성비는 1:1로 유의한 차이를 보이지 않았다($X^2=0.18$, p>0.05). 조사된 해가리비의 조직학적 절편에서 자웅동체인 개체는 발견되지 않았다.

  • PDF