• Title/Summary/Keyword: Spontaneously

Search Result 1,157, Processing Time 0.032 seconds

The Effects of CIF$_3$and F$_2$on the Flammability Limit of H$_2$ (H$_2$의 연소한계에 미치는 F$_2$와 CIF$_3$의 영향)

  • ;H.Ohtani;Y.Uehara
    • Journal of the Korean Society of Safety
    • /
    • v.9 no.3
    • /
    • pp.53-59
    • /
    • 1994
  • Hydrogen(H$_2$) is used in the semiconductor industries, and some oxidizing gases such as fluoride(F$_2$) and chlorine trifluoride(CIF$_3$) are also used. As F$_2$and CIF$_3$are highly oxidizing gases, it were supposed to react vigorously with H$_2$. In this study, the flammability limit of F$_2$/$H_2$/Ar and CIF$_3$/$H_2$/Ar mixtures were investigated experimentally. As a result, it was found that the diluted F$_2$gas could be spontaneously ignited as compared to CIF$_3$mixture gas while being mixed with the diluted H$_2$gas. However, CIF$_3$diluted gas was not able to ignite spontaneously except for an electric spark. And the combustion characteristics and reaction kinetics were shown at the different diluted gases by the flammability diagram analyses between the F$_2$/$H_2$/Ar and CIF$_3$/$H_2$/Ar.

  • PDF

MR Images of Spontaneously Involuted Atretic Cephalocele Concomitant with Persistent Falcine Sinus in an Adult (성인에서 지속적인 낫형동을 동반한 자연퇴축된 위축뇌탈출증의 MR영상소견)

  • Cho, Joon;Roh, Hong-Gee;Moon, Won-Jin;Kim, Mi-Young
    • Investigative Magnetic Resonance Imaging
    • /
    • v.10 no.2
    • /
    • pp.117-120
    • /
    • 2006
  • Atretic cephalocelces are defined as skin-covered midline subscalp lesions that contain meninges and rest of glial and/or central nervous system tissue. When the straight sinus is absent or rudimentary, the falcine sinus can be recanalized to enable venous drainage. Although the atretic cephalocele or persistent falcine sinus has largely been described in the pediatric population, it is a rarely observed in the adult population. We report a unique case of spontaneously involuted atretic cephalocele coexistent with persistent falcine sinus in an adult. MR images and MR venography were useful for diagnosis and accurate anatomical depiction.

  • PDF

Antihypertensive Properties of Dried Radish Leaves Powder in Spontaneously Hypertensive Rats (자연발증적 고혈압 흰쥐에서 무청 건조분말의 항고혈압 효과)

  • Kim, Bo-Ram;Park, Ji-Ho;Kim, Sun-Hee;Cho, Kang-Jin;Chang, Moon-Jeong
    • Journal of Nutrition and Health
    • /
    • v.43 no.6
    • /
    • pp.561-569
    • /
    • 2010
  • The study aim was to investigate the antihypertensive effect after oral supplementation of dried radish leaves powder (DRLP). Angiotensin-converting enzyme (ACE) activity was measured by spectrophotometric assay. The systolic blood pressure (SBP) was measured in spontaneously hypertensive (SHR) and normotensive rats (Wistar) by the tail cuff method after a 4-week diet with DRLP at the level of 2.5% or 5%. The supplementation of DRLP decreased SBP of SHR although the 5% supplementation level did not show any more pronounced effect than the 2.5% level did. The decrease in the SBP observed for both 2.5% and 5% DRLP was accompanied by significant increases of the urinary Na and K excretion. The DRLP supplementation showed a potent ACE-inhibitory activity in pulmonary tissue from both hypertensive and normotensive rats. However, the DRLP supplementation did not affect the SBP in normotensive rats. These results indicated that DRLP exerted an antihypertensive effect in SHR due to the decreased ACE activity and increased urinary Na excretion.

Ginsenosides Inhibit Endothelium - dependent Contraction in the Spontaneously Hypertensive Rat Aorta isn vitro (선천성 고혈압 랫드에서 ginsenosides에 의한 내피의존성수축의 억제작용)

  • 김낙두;최원선
    • Journal of Ginseng Research
    • /
    • v.21 no.2
    • /
    • pp.125-132
    • /
    • 1997
  • Our previous study showed that in vivo treatment of spontaneously hypertensive rats (SHR) with protopanaxatriol ginsenosides (PPT) reduces the blood pressure and inhibits the con- tractions induced by endothelium-derived contracting factor (prostaglandin endoperoxide ($PGH_2$) and superoxide anion) in aorta isolated from SHR. The aim of the present study is to examine whether PPT improves endothelial functions in the isolated thoracic aorta of SHR in vitro. Treatments of aortic rings with PPT, purified ginsenoside $Rg_1$ ($Rg_1$) or indomethacin normalized endotheliuln-dependent relaxation to acetylcholine, but not with protopanaxadiol ginsenosides (PPD) and purified ginsenoside Rb1 (Rb1). The effects of PPT were dose-dependent. PGH,- and oxygen free radical-inducted contractions in rat aorta without endothelium were inhibited by PPT or $Rg_1$, but not by PPD or $Rb_1$. Contractions induced by PGF2$\alpha$, U-46619, a stable thromboxane A2 agonist or KCI (60 mM) were not inhibited by PPT, $Rg_1$ or $Rb_1$. These findings demonstrate that PPT but not PPD scavenges the oxygen-derived free radicals and/or antagonize the effects of $PGH_2$ in the vascular smooth muscle and may explain the hypotensive effect of ginseng in the SHR.

  • PDF

Antihypertensive effect of ethanol extracts of Aralia elata in spontaneously hypertensive rats (선천성 고혈압 흰쥐에서 두릅 에탄올 추출물의 항고혈압 효과)

  • Jin, Ju-Youn;Park, Eun-Hye;Jeon, Yoon-A;Lee, Young-Jae
    • Korean Journal of Veterinary Research
    • /
    • v.57 no.3
    • /
    • pp.181-187
    • /
    • 2017
  • Antihypertensive effects of ethanol extracts of Aralia elata (Miq.) Seem. (AE) were investigated in spontaneously hypertensive rats (SHR). SHR aged 14 weeks were treated for 8 weeks with AE (10 or 50 mg/kg/day) or amlodipine besylate (Am; 10 mg/kg/day) orally. Hypertension results in injury to several organs and can produce a significant increase in malondialdehyde (MDA) content as a result of lipid peroxidation and endothelial dysfunction. In this study, oral administration of AE and Am significantly reduced systolic blood pressure, organ weight index, and MDA content in tissues but increased significantly the plasma nitrite and nitrate concentrations. The endothelium-dependent relaxant activities of acetylcholine ($10^{-10}-10^{-3}M$) in norepinephrine (NE)-precontracted aorta were increased in AE- and Am-treated rats. Particularly strong endothelium-dependent relaxant activities were observed in AE-treated (50 mg/kg) rats. The endothelium-independent relaxant activities of sodium nitroprusside ($10^{-10}-10^{-3}M$) in NE-precontracted aorta were not changed. The results of this study suggest that AE has both antihypertensive and end-organ protective effects in SHR.

Effects of Aqua-acupuncture of Semen Cuscutae on the Blood Pressure in Spontaneously Hypertensive Rats (토사자(兎絲子) 약침(藥鍼)이 자연발증(自然發證) 고혈압(高血壓) 백서(白鼠)의 혈압(血壓)에 미치는 영향(影響))

  • Yu Yun-Cho;Han Jeong-Woo;Yuk Tae-Han;Lee Ho-Sub
    • Journal of Acupuncture Research
    • /
    • v.15 no.2
    • /
    • pp.349-356
    • /
    • 1998
  • The aim of the experiments was to investigate the effect of Semen Cuscutae aqua-acupuncture at the meridian point BL 20(脾兪) and BL 23(賢兪) on the blood pressure, plasma renin activity, plasma levels of aldosterone and atrial natriuretic peptide (ANP) in spontaneously hypertensive rats (SHR). The results of this study were as follows: 1. Systolic blood pressure was decreased significantly after Semen Cuscutae aqua-acupuncture at the meridian point BL 20, BL 23. 2. Plasma renin activity was increased significantly after Semen Cuscutae aqua-acupuncture at meridian point BL 23, BL 20. 3. Plasma levels of aldosterone was increased significantly after Semen Cuscutae aqua-acupuncture at the meridian point BL 20. 4. Plasma levels of atrial natriuretic peptide (ANP) was increased significantly after Semen Cuscutae aqua-acupuncture at the meridian point BL 23, but it was decreased significantly after Semen Cuscutae aqua-acupuncture at the meridian point BL 20. These results suggest that the changes of the depressor response after Semen Cuscutae aqua-acupuncture at the meridian point BL 20, BL 23 are related to the changes of the plasma renin activity, plasma levels of atrial natriuretic peptide (ANP) and aldosterone.

  • PDF

Almost Spontaneously Developed Rupture of Bilateral Achilles Tendons - 1 case report - (거의 자연 발생된 양측 아킬레스건의 파열 - 1예 보고 -)

  • Park, In-Heon;Song, Kyung-Won;Shin, Sung-Il;Lee, Jin-Young;Park, Sung-Jin;Hyun, Youn-Seok
    • Journal of Korean Foot and Ankle Society
    • /
    • v.6 no.1
    • /
    • pp.106-110
    • /
    • 2002
  • The rupture of the Achilles tendon is rather uncommon, but its incidence has been increasing. Main causes are usually due to direct injury or sudden indirect high energy trauma such as sports activity without predisposing disease. Spontaneous rupture of the Achilles tendon are sporadically reported especially from person who took steroid or with similiar predisposing disease. We experienced a patient with bilateral ruptures of the Achilles tendon that had occurred almost spontaneously, without any steroid related medication or underlying diseases.

  • PDF

Acute Respiratory Distress Due to Methane Inhalation

  • Jo, Jun Yeon;Kwon, Yong Sik;Lee, Jin Wook;Park, Jae Seok;Rho, Byung Hak;Choi, Won-Il
    • Tuberculosis and Respiratory Diseases
    • /
    • v.74 no.3
    • /
    • pp.120-123
    • /
    • 2013
  • Inhalation of toxic gases can lead to pneumonitis. It has been known that methane gas intoxication causes loss of consciousness or asphyxia. There is, however, a paucity of information about acute pulmonary toxicity from methane gas inhalation. A 21-year-old man was presented with respiratory distress after an accidental exposure to methane gas for one minute. He came in with a drowsy mentality and hypoxemia. Mechanical ventilation was applied immediately. The patient's symptoms and chest radiographic findings were consistent with acute pneumonitis. He recovered spontaneously and was discharged after 5 days without other specific treatment. His pulmonary function test, 4 days after methane gas exposure, revealed a restrictive ventilatory defect. In conclusion, acute pulmonary injury can occur with a restrictive ventilator defect after a short exposure to methane gas. The lung injury was spontaneously resolved without any significant sequela.

Effects of Piroxicam on Pharmacodynamics and Pharmacokinetics of Nifedipine in Spontaneously Hypertensive Rats (피록시캄이 니페디핀의 약력학 및 약동학에 미치는 영향)

  • 최기환;박인숙;김동섭;정혜주
    • YAKHAK HOEJI
    • /
    • v.44 no.3
    • /
    • pp.245-250
    • /
    • 2000
  • Because nonsteroidal anti-inflammatory drugs are reported to cause fluid retention and hypertension by inhibition of prostaglandin synthesis, the effects of piroxicam on pharmacodynamics and pharmacokinetics of nifedipine were studied in male spontaneously hypertensive rats. They received nifedipine (0.5 mg/kg) alone or combined with piroxicam (5 mg/kg) intravenously. Plasma levels norepinephrine, an index of sympathetic stimulation, were measured prior to each treatment and 5 min after drug administration. Changes in blood pressure were examined serially and blood samples for analysis of nifedipine were also taken for 6 hr following drug administration. Plasma nifedipine concentration were assayed by HPLC and pharmacokinetic parameters were calculated. Blood pressure was reduced (p<0.01), but plasma norepinephrine level was increased (p<0.05) by nifedipine administration. Anti-hypertensive effect of nifedipine was potentiated (p<0.05) by piroxicam coadministration, but effect of nifedipine on plasma norepinephrine level was not affected. In case of rats received nifedipine and piroxicam, plasma nifedipine concentrations were higher (p<0.05) than those from rats received nifedipine alone at 2,3,4,5 and 6 hours following drug administration. The area under the plasma concentration vs. time curve was increased (p<0.05), while the elimination rate constant was decreased (p<0.01) by piroxicam coadministration. No significant differences were observed in the plasma clearance, apparent volume of distribution and elimination half-life. Thus, piroxicam not only potentiated antihypertensive effect of nifedipine, but also altered nifedipine pharmacokinetics in the rats. It is concluded that the potentiation of nifedipine antihypertensive effect might correlate with the increment of its plasma concentration by piroxicam coadministration.

  • PDF

Characteristics of Voltage-Dependent Clacium Uptake and Norepinephrine Release in Hypothalamus of SHR

  • Yi, Sook-Young;Kim, Yun-Tai;Kim, Kyeong-Man;Ko, Kwang-Ho
    • Archives of Pharmacal Research
    • /
    • v.17 no.4
    • /
    • pp.226-230
    • /
    • 1994
  • The characteristics of voltage-dependent ^{45}Calcium$ uptake and norepinephrine release as factors controlling neural activities in the hypothalamus which is an important regulatory site for cardiovascular function wre studied. Two groups of animals : male spontaneously hyperterisive rat (SHR) and age-matched nomotensive wistar rat (NW) were used in this study. Animals at 4, 6 and 16 weeks of age were sacrificed by decapitiation and the hypothalamus was dissected out. Voltage-dependent calcium uptake and norepinephrine release were determined from hypothalamic synaptosomes either in low potassium (5 mM) or high potassium (41 mM) stimulatory conditions by using ^{45}Ca$ isotope and HPLC-ECD techniques. Degrees of voltage-dependent ^{45}Calcium$ uptake and norepinephrine release evoked by calcium uptake in the hypothalamus of prehypertensive phase (4 weeks old) of SHR were significantly smaller than those in NW of the same age. However, in the developmental phase (6 weeks old) and the established phase (16 weeks old) of hyperrtension in SHR, degrees of voltage-dependent ^{45}Calcium$ uptake and norepinephrine release were similar to those of age-matched normotensive wistae eats. These data imply that the deficit in hypothalamic norepinephrine release might be an important underlying factor for the development of hypertension in SHR.

  • PDF