• Title/Summary/Keyword: FRAGMENTATION

Search Result 1,876, Processing Time 0.026 seconds

Pretreatment of Low Dose Radiation Reduces Radiation-Induced Apoptosis in Mouse Lymphoma (EL4) cells

  • Kim, Jeong-Hee;Hyun, Soo-Jin;Yoon, Moon-Young;Jioon, Young-Hoon;Cho, Chul-Koo;Yoo, Seong-Yul
    • Archives of Pharmacal Research
    • /
    • v.20 no.3
    • /
    • pp.212-217
    • /
    • 1997
  • Induction of an adaptive response to ionizing radiation in mouse lymphoma (EL4) cells was studied by using cell survival fraction and apoptotic nucleosomal DNA fragmentation as biological end points. Cells in early log phase were pre-exposed to low dose of ${\gamma}$-rays (0.01 Gy) 4 or 20 hrs prior to high dose ${\gamma}$-ray (4, 8 and 12 Gy for cell survival fraction analysis; 8 Gy for DNA fragmentation analysis) irradiation. Then cell survival fractions and the extent of DNA fragmentation were measured. Significant adaptive response, increase in cell survival fraction and decrease in the extent of DNA fragmentation were induced when low and high dose .gamma.-ray irradiation time interval was 4 hr. Addition of protein or RNA synthesis inhibitor, cycloheximide or 5,6-dichloro-1-.betha.-d-ribofuranosylbenzimidazole (DRFB), respectively during adaptation period, the period from low dose ${\gamma}$-ray irradiation to high dose ${\gamma}$-ray irradiation, was able to inhibit the induction of adaptive response, which is the reduction of the extent DNA fragmentation in irradiated EL4 cells. These data suggest that the induction of adaptive response to ionizing radiation in EL4 cells required both protein and RNA synthesis.

  • PDF

ICT and the Changing Nature of Work: Work Fragmentation (ICT와 업무의 변화 - 일의 파편화 관점에서 -)

  • Lee, Seyoon;Park, Jun-Gi;Lee, Jungwoo
    • Informatization Policy
    • /
    • v.21 no.1
    • /
    • pp.35-56
    • /
    • 2014
  • Information and communication technologies(ICT) allow and force people to work anywhere, anytime using remote databases and application systems available in real-time twenty four hours a day and seven days a week. With the real time nature of ICT, individual work is becoming more and more fragmented. Instead of working on a similar task repeatedly, individuals are required to respond to e-mails and inquiries through social networks, work on planning documents, work on presentation documents, work on spreadsheets, input necessary data on company databases, generate necessary reports from the database, run teleconference, etc., all maybe in a day's work. Work fragmentation may impact negatively on productivity as the flow is interrupted, but it may increase the productivity by allowing people to handle multiple tasks in a shorter time period. This study explores the types of work fragmentation and their characteristics. An online survey was administered to collect data about work fragmentation and work characteristics including autonomy, complexity, flexibility, usage of ICT, etc. 300 cases were used in the analysis. Analysis of k-mean cluster indicated four different types of work fragmentation: concentrated, temporally distributed, spatially distributed, and fully fragmented.

Fragmentation Fractal Analysis on Particle-size Distribution (Fragmentation 프랙탈을 이용한 입도분포 분석)

  • 민덕기;이완진
    • Journal of the Korean Geotechnical Society
    • /
    • v.19 no.2
    • /
    • pp.199-206
    • /
    • 2003
  • Particle-size distribution in soils is one of the most fundamental physical properties of soils. One of the latest developments in the study of particle-size distributions has focused on the use of fractal theories. In this study, the fragmentation fractals were used for determining the characteristics of the particle-size distribution curve. It was shown that the mass-size distribution method was more practical than the cumulative number-size distribution method. From the co-relation between fractal dimensions($D_{tot}$) and the coefficient of uniformity($C_{u}$), there was a sharp increase in fractal dimensions for $C_{u}$<4, but fractal dimension converged the single value for $D_{u}$$\geq$6. Fractal dimensions were affected by small sized particles for $C_{c}$$\geq$3 and large sized particles for $C_{c}$/<3. As a result of the analysis of the influence of the effective size($D_{10}$), it was observed that the changes of $D_{tot}$/ were nominal beyond the effective size.

Correlations between abnormalities of morphological details and DNA fragmentation in human sperm

  • Nguyen, Hiep Tuyet Thi;Dang, Hong Nhan Thi;Nguyen, Thai Thanh Thi;Nguyen, Trung Van;Dang, Thuan Cong;Nguyen, Quoc Huy Vu;Le, Minh Tam
    • Clinical and Experimental Reproductive Medicine
    • /
    • v.49 no.1
    • /
    • pp.40-48
    • /
    • 2022
  • Objective: As the associations of sperm DNA fragmentation with morphology have not been examined in detail, this study aimed to investigate the relationship between abnormalities of morphological details and DNA integrity in human sperm. Methods: In this cross-sectional study, men from infertile couples were enrolled at Hue Center for Reproductive Endocrinology and Infertility, Vietnam. Conventional semen parameters, including morphological details, were analyzed following the World Health Organization 2010 criteria. Sperm DNA fragmentation was evaluated using a sperm chromatin dispersion assay. The relationships and correlations between semen parameters, sperm morphology, and the type of halosperm and the DNA fragmentation index (DFI) were analyzed. Results: Among 130 men in infertile couples, statistically significant differences were not found in the sperm halo type between the normal and abnormal sperm morphology groups. The percentage of round-head spermatozoa was higher in the DFI >15% group (16.98%±12.50%) than in the DFI ≤15% group (13.13% ±8.82%), higher values for amorphous heads were found in the DFI >15% group, and lower values for tapered heads were observed in the DFI ≤15% group; however, these differences were not statistically significant. Small-halo sperm and the DFI were positively correlated with round-head sperm (r=0.243, p=0.005 and r=0.197, p=0.025, respectively). Conclusion: The rate of general sperm morphological abnormalities in semen analysis was not related to sperm DNA integrity. However, round sperm heads were closely associated with sperm DNA fragmentation.

Effects of Chronic Sleep Fragmentation and Diet Restriction on Appetite-Regulating Hormones and Cardiometabolic Indicators (만성 분절수면과 식이제한이 식욕조절 호르몬 및 심혈관 위험지표에 미치는 영향)

  • Jun, Nuri;Baik, Inkyung
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.46 no.2
    • /
    • pp.153-160
    • /
    • 2017
  • Data are limited on biological mechanisms underlying the associations of sleep insufficiency with obesity and dyslipidemia. To explore these mechanisms, we investigated appetite-regulating hormones, stress-related hormones, and cardiometabolic indicators in association with sleep fragmentation, which is a type of sleep disorder. In an experimental study, we randomly allocated 40 Wistar male rats aged 7 weeks into four groups; rats with ad libitum sleep and ad libitum intake (Control), those exposed to sleep fragmentation (SF), those with diet restriction (DR), and those exposed to sleep fragmentation and diet restriction (SF+DR). Amongst them, 13-day chronic sleep fragmentation was applied to the SF and SF+DR groups while 50% reduction in chow intake was applied to the DR and SF+DR groups for 13 days. After these experiments, blood lipid and lipoprotein profiles, leptin, ghrelin, adiponectin, cortisol, epinephrine, and norepinephrine levels were compared among the four groups. In the results, the SF group showed the highest levels of serum ghrelin (P<0.001) and the lowest levels of serum adiponectin (P<0.01). All experimental groups showed higher levels of low density lipoprotein-cholesterol (LDL-C) than the Control (P<0.001). LDL-C levels and the ratio of LDL-C and high density lipoprotein-cholesterol were positively correlated with ghrelin levels (P<0.05) in the SF group, but not in the DR and SF+DR groups. In the SF group, the highest levels of serum free fatty acids were also observed and correlated with lower levels of serum adiponectin, which reflects insulin resistance (P<0.05). Based on these findings, we suggest that chronic sleep fragmentation may induce disturbances in lipid metabolism and appetite-regulating hormones independent of food intake, and these metabolic disturbances may be worse due to insulin resistance related to overeating, which is indicated by elevated ghrelin levels in sleep fragmentation. For persons with sleep insufficiency, anti-atherogenic dietary interventions may be recommended to prevent cardiovascular disease.

A Study on the 'fragmentation' trend of modern film montage (현대영화 몽타주의 '파편화(fragmentation)' 경향 연구)

  • LEE, Jiyoung
    • Trans-
    • /
    • v.3
    • /
    • pp.29-53
    • /
    • 2017
  • The film scholar Vincent Amiel divides into three types of montage through his book The Aesthetics of Montage ; Montage narratif, Montage discursif, and Montage decorrespondances. These three categories are the concept that encompasses the aesthetic class to which most movies belong. Early films pursued the essential and basic functions of editing, which tend to be modified in the direction of enhancing the director's goals over time. In this way, "Expressive Montage" is one of most important concepts of montage, not as a 'methodology' that combines narrative but as a 'purpose'. In the montage stage, the expressive montage work is done through three steps of decision. The process of 'combining' to combine the selected films in a certain order, after the process of 'selection' which selects only necessary parts of the rush film, and 'connection' to determine the scene connection considering the duration of the shot. The connection is the final stage of the montage. There are exceptions, of course. When fiction films of classical narratives use close-ups, or when using models or objects of neutered animals, the film induces the tendency of a "montage decorrespondances" rather than a "montage narratif" or "montage discursif". This study attempts to analyze the tendency of montage of works with 'uncertain connection' through 'collage' used by close-ups and montage decorrespondances as 'fragmentation tendency of modern films'. The fragmentation of the montage in contemporary film breaks the continuous and structural nature of the film, and confuses the narration structure that is visible on the surface of the film. The tendency of the fragmentation of the montage, which started from this close-up, seems to give an answer to the extensibility of the modern image.

  • PDF

Identification and evaluation of fragmentation pathways of PDE-5 inhibitor analogues using LC-QTOF-MS (LC-QTOF-MS를 이용한 발기부전치료제 유사물질의 fragmentation pathway 분석)

  • Do, Jung-Ah;Noh, Eunyoung;Yoon, Soon-Byung;Park, Hyoung-Joon;Cho, Sooyeul;Park, Sung-Kwan;Yoon, Chang-Yong
    • Analytical Science and Technology
    • /
    • v.28 no.4
    • /
    • pp.278-287
    • /
    • 2015
  • Phosphodiesterase type 5 inhibitors (PDE-5 inhibitors) are used in the treatment of erectile dysfunction. In recent years, a number of reports have been conducted on dietary supplements contaminated with PDE-5 analogues. In this study, 58 analogues of PDE-5 inhibitors were sorted into five groups: tadalafil, sildenafil, hongdenafil, vardenafil, and other analogues. These analogues were then evaluated using a liquid chromatography-quadrupole-time of flight mass spectrometry (LC-QTOF-MS) electrospray ionization mass method. Each compound has a unique fragmentation ion, which can be easily analyzed qualitatively. The fragmentation pathways of the analogues were elucidated based on the QTOF-MS and MS/MS data. Common ions were confirmed for each group by analyzing the structural characteristics and fragmentation pathways. Specifically, common ions were observed at m/z 169.08 and 135.04 (tadalafil analogues), m/z 311.15 and 283.12 (sildenafil analogues and hongdenafil analogues), and m/z 312.16 and 151.09 (vardenafil analogues). The advantage of this method is that the structure of unknown components can be determined by interpreting the product ions. Hence, the developed method can be used for the identification of unknown compounds. Fragmentation pathways may also aid in the detection and identification of PDE-5 inhibitor analogues.