• Title/Summary/Keyword: Burst index

Search Result 80, Processing Time 0.026 seconds

Comparative Study of Brain Protection Effect between Thiopental and Etomidate Using Bispectral Index during Temporary Arterial Occlusion

  • Kim, Tae-Kwan;Park, Ik-Seong
    • Journal of Korean Neurosurgical Society
    • /
    • v.50 no.6
    • /
    • pp.497-502
    • /
    • 2011
  • Objective : This study was conducted to compare the effect of etomidate with that of thiopental on brain protection during temporary vessel occlusion, which was measured by burst suppression rate (BSR) with the Bispectral Index (BIS) monitor. Methods : Temporary parent artery occlusion was performed in forty one patients during cerebral aneurysm surgery. They were randomly assigned to one of two groups. General anesthesia was induced and maintained with 1.5-2.5 vol% sevoflurane and 50% $N_2O$. The pharmacological burst suppression (BS) was induced by a bolus injection of thiopental (5 mg/kg, group T) or etomidate (0.3 mg/kg, group E) according to randomization prior to surgery. After administration of drugs, the hemodynamic variables, the onset time of BS, the numerical values of BIS and BSR were recorded at every minutes. Results : There were no significant differences of the demographics, the BIS numbers and the hemodynamic variables prior to injection of drugs. The durations of burst suppression in group E ($11.1{\pm}6.8$ min) were not statistically different from that of group T ($11.1{\pm}5.6$ min) and nearly same pattern of burst suppression were shown in both groups. More phenylephrine was required to maintain normal blood pressure in the group T. Conclusion : Thiopental and etomidate have same duration and a similar magnitude of burst suppression with conventional doses during temporary arterial occlusion. These findings suggest that additional administration of either drug is needed to ensure the BS when the temporary occlusion time exceed more than 11 minutes. Etomidate can be a safer substitute for thiopental in aneurysm surgery.

Treatment of Thoracolumbar and Lumbar Unstable Burst Fractures by Using Combined and Posterior Surgery

  • Shin, Jong Ki;Goh, Tae Sik;Son, Seung Min;Lee, Jung Sub
    • Journal of Trauma and Injury
    • /
    • v.29 no.1
    • /
    • pp.14-21
    • /
    • 2016
  • Purpose: The purpose of this research was to analyze the results of the combined and posterior approaches for treating thoracolumbar and lumbar burst fractures and to find an adequate method of treatment. Methods: We retrospectively analyzed the cases of 46 patients with unstable thoracolumbar and lumbar burst fractures who had been surgically treated. All cases were divided into two groups based on the operation method used. Eleven patients had undergone the combined approach, while 35 patients had undergone the posterior approach. Radiological and clinical evaluations were performed before surgery, after surgery, and at the final follow-up. Results: The stenotic ratios of the area occupied by the retropulsed bony fragments to the estimated area of the original spinal canal were 68.2% and 45.6% for the combined and the posterior approaches, respectively. No significant differences in the neurological improvement or the corrected state of the sagittal index were noted, but the patients who had been treated with the combined approach group had better results than those who had been treated with the posterior approach group in terms of correction and maintenance of the sagittal index. The average kyphosis corrections at the final follow-up were 15.3 degrees for the patients in the combined approach group and 10.0 degrees for those in the posterior approach group. Surgical time and estimated blood loss were all significantly higher for patients in the combined approach group. Conclusion: The combined and the posterior approaches showed similar results in the improvements of the neurologic state and the corrected state of the sagittal index. However, use of the combined approach is recommended for patients with severe kyphosis and with severe canal encroachment.

Radiation mechanism of gamma-ray burst prompt emission

  • Uhm, Z. Lucas;Zhang, Bing
    • The Bulletin of The Korean Astronomical Society
    • /
    • v.40 no.1
    • /
    • pp.49.3-50
    • /
    • 2015
  • Synchrotron radiation of relativistic electrons is an important radiation mechanism in many astrophysical sources. In the sources where the synchrotron cooling timescale is shorter than the dynamical timescale, electrons are cooled down below the minimum injection energy. It has been believed that such fast-cooling electrons have a power-law distribution in energy with an index -2, and their synchrotron radiation has a photon spectral index -1.5. On the other hand, in a transient expanding astrophysical source, such as a gamma-ray burst (GRB), the magnetic field strength in the emission region continuously decreases with radius. Here we study such a system, and find that in a certain parameter regime, the fast-cooling electrons can have a harder energy spectrum. We apply this new physical regime to GRBs, and suggest that the GRB prompt emission spectra whose low-energy photon spectral index has a typical value -1 could be due to synchrotron radiation in this moderately fast-cooling regime.

  • PDF

The Prediction of Structural Behavior for Composite Pressure Vessel with Changed Dome Shape (돔 형상 변화에 따른 복합재 압력용기의 구조 거동 예측)

  • Hwang, Tae-Kyung;Park, Jae-Byum;Kim, Hyung-Kun;Doh, Young-Dae
    • Proceedings of the Korean Society of Propulsion Engineers Conference
    • /
    • 2008.11a
    • /
    • pp.288-292
    • /
    • 2008
  • Dome shape design method of filament wound (FW) composite pressure vessel, which can create various dome shape with fixed boss opening, was suggested. And, the performance indices (PV/W) for composite pressure vessel with same boss opening but different dome shape were investigated by finite element analysis (FEA) and hydro-test. The FEA showed good agreement with test results for burst pressure. Generally, as the dome shape of pressure vessel was changed to flat dome, the inner volume is increased and the burst pressure is decreased. In the case of above ${\rho}_o$=0.54, the performance index showed decreased value due to the low burst pressure. However, at ${\rho}_o$=0.35, the dome shape change brings not significant reduction of burst pressure and performance index.

  • PDF

Manufacture of Environmentally-friendly Flame-retardant Paper with Polyethylene Terephthalate (PET) Short Cut Fiber (PET 섬유를 사용한 친환경 난연지 제조방법에 대한 연구)

  • Kim, Ji-Seop;Lee, Myoung-Ku
    • Journal of Korea Technical Association of The Pulp and Paper Industry
    • /
    • v.44 no.5
    • /
    • pp.14-20
    • /
    • 2012
  • In this paper, the flame-retardant wall paper was successfully prepared with recycled polyethylene terephthalate (PET) short cut fiber with flame-retardant property and wood pulp using polyvinyl alcohol (PVA) as binder followed by treatment of non-halogen flame retardant. Physical properties such as formation index, tensile strength, elongation, and burst strength increased as defibrillation increased except tear strength. Bulk increased but formation index, tensile strength, elongation and burst strength decreased along with addition of PET short cut fiber. It was also found that tear strength rose significantly up to 30% of PET short cut fiber and then declined (fell) rapidly. As addition level of PVA increased tensile strength, elongation and burst strength increased, but tear strength decreased slightly. Addition of 20% of PET short cut fiber and 13% of PVA provided the flame-retardant wall paper with both improved flameproofing and physical properties.

Effects of Refining and Blending of Pulps on the Physical Properties of Paper (펄프의 고해 및 배합 방법이 종이의 물성에 미치는 영향)

  • Won, Jong-Myoung;Shin, Dong-Joon;Kim, Heung-Bae
    • Journal of Korea Technical Association of The Pulp and Paper Industry
    • /
    • v.41 no.2
    • /
    • pp.7-12
    • /
    • 2009
  • The effects of refining either SwBKP or HwBKP, and both of SwBKP and HwBKP on the physical properties of paper were investigated in order to elucidate if the non-conventional refining and blending method can be used for the optimizing the paper properties. The blending ratio of SwBKP and HwBKP was 15:85. The highest bulk was obtained with the refining of SwBKP only. Any differences of opacity were not observed in unfilled paper, while the highest opacity of PCC filled paper was obtained at same bulk when the only HwBKP was refined. However burst index and tensile index did not showed any differences in the relationship with bulk. Therefore this result can be applied to improve the opacity of paper without sacrificing of strength properties.

An Agrometeorological Reference Index for Projecting Weather-Related Crop Risk under Climate Change Scenario (농작물의 기상재해 발생위험 판정기준 설정 및 지구 온난화에 따른 기준기상위험의 변화 전망)

  • Kim, Dae-jun;Kim, Jin-hee;Yun, Jin I.
    • Korean Journal of Agricultural and Forest Meteorology
    • /
    • v.18 no.3
    • /
    • pp.162-169
    • /
    • 2016
  • The agrometeorological reference index means 'the agrometeorological damage possibility' or the possibility of the normal year climate condition to damage the crop cultivation in a certain region. It is a reference used to compare the cultivation risk of a crop by region. The global climate warming is expected to increase the winter temperature. At the same time, the frequency of extreme weather events will also increase. Therefore, people pay attention to the potential of low temperature-induced damages (e.g., frost damage and injury) to fruit trees under the future climate condition. However, simple damage projection based on climate conditions does not help the climate change adaptation in the practical aspect because the climate change affects the phenology of fruit trees as well. This study predicted the phenology of the pear, peach, and apple trees by using the climate change scenarios of major regions. Furthermore, low temperature induced agrometeorological reference indices were calculated based on the effects of temperature on each plant growth stage to predict the damage possibility. It was predicted that the breaking rest would delay more in the future while the bud-burst date and flowering date will be earlier. In Daegu, Jeonju, and Mokpo, the breaking rest delayed more as time passed. The bud-burst date and flowering date of Seoul and Incheon regions were later than other regions. Seoul and Incheon showed a similar pattern, while Daegu and Jeonju revealed a similar pattern. Busan and Mokpo also showed a similar pattern. All regions were safe from the frost damage during the dormancy period. However, plants were vulnerable to frost damage between the breaking rest and the bud-burst period. Regions showed different frost damage patterns between the bud-burst period and the flowering period. During the bud-burst and flowering period, the risk level decreased in general, although the risk of some areas tended to increase.

A Case Report of Prescribing Chungungyukgye-tang (Chuanxiongrougui-tang) for the One Patient with Lumbar Burst Fracture (천궁육계탕(川芎肉桂湯)을 투여한 요추 방출성 골절 환자 치험 1례)

  • Jung, Yoon-Gyoo;Kim, Jin-Soo;Uhm, Bong-Kun;Shin, Dong-Jae;Kim, Young-Jee
    • The Journal of Churna Manual Medicine for Spine and Nerves
    • /
    • v.6 no.1
    • /
    • pp.113-119
    • /
    • 2011
  • Objectives: The purpose of this study is to investigate the clinical application of Chungungyukgye-tang(Chuanxiongrougui-tang) to one patient with lumbar burst fracture. Methods: Patient is hopitalized at Dept. of Oriental Internal Medicine, Bu-Chun Jaseng Oriental Medicine Hospital, diagnosed as lumbar burst fracture and treated mainly with herbal medine ; Chungungyukgye-tang(Chuanxiongrougui-tang). This study was measured by ODI(Oswestry Disability Index) and NRS(Numeric Rating Scale) score. Results: After taking Chungungyukgye-tang(Chuanxiongrougui-tang), the patient's pain was controlled. NRS & ODI score were decreased. Conclusions: As seen in this one case of lumbar burst fracture, Chungungyukgye-tang(Chuanxiongrougui-tang) has a positive effect to control pain with lumbar burst fracture.

  • PDF

Internal Stress and Physical Properties of Multi-layered Paper (다층지의 내부응력과 물성)

  • Won, Jong Myoung
    • Journal of Forest and Environmental Science
    • /
    • v.14 no.1
    • /
    • pp.89-100
    • /
    • 1998
  • The study was carried to investigate the change of internal stress and physical properties of paper by the mutiplying of paper structuring that is an useful means to maximize the performance and use of the fiber raw material. The effects of recycled fiber on the physical properties of multiplied paper also were studied. The beating increased the internal stress of single layered paper, while filler loading decreased the internal stress. Multiplying the structure of paper decreased the internal stress and the most of physical properties except for tear index. It was found that the properties of paper could be changed by the pulp type, beating and the combination of raw materials. The introduction of filler in the middle and/or outer layer could improved the internal stress, tensile index, tear index and burst index. The addition of recycled fiber increased the opacity and stiffness of paper in both single layered and multiplied paper. Multiplying the structure of paper improved the air permeability and stiffness, while decreased burst index.

  • PDF

Strength Property Improvement of OCC-based Paper by Chemical and Mechanical Treatments(I) (골판지 고지의 물리화학적 처리에 의한 강도 향상(제 1 보))

  • Lee, Jong-Hoon;Seo, Yung B.;Jeon, Yang
    • Journal of Korea Technical Association of The Pulp and Paper Industry
    • /
    • v.32 no.1
    • /
    • pp.10-18
    • /
    • 2000
  • To improve the physical properties of OCC (Old Corrugated Container) fibers, we used the mechanical pre-treatment on the fibers before refining . The mechanical action in the Hobart mixer induced high shear and compression on the fibers, which resulted in changes of fiber internal structure, and microcompressions on the surface of the fibers. We evaluated the amount of mechanical treatment on the fibers by fiber curl index for convenience. Four different refining techniques were applied to the pre-treated fibers (valley beater, Kady mill, PFI mill, and Impact refining) to find the best combination of the pre-treatment and the refining methods. Conclusions were summarized as followed. 1. Mechanical pre-treatment in Hobart mixer for more than 1 hour caused the increase of curl index of OCC fibers, and increased breaking length, burst index, and tear index the handsheets more than 10 % in this experiment. 2. Kady mill and PFI mill refining were effective in keeping fiber length from shortening Kady mill and Valley beater refining straightened out the fiber curls, and reduced the curl index. 3. Valley beating reduced fiber length very fast and generated fines more than other refining methods. 4. To increase breaking length and burst strength while keeping tear strength , combination of mechanical pre-treatment and Valley beating were most effective.

  • PDF