• 제목/요약/키워드: stress recovery

검색결과 659건 처리시간 0.025초

Influence of Compositions of Sintered Ti-Ni Alloys on their Thermo-mechanical Properties

  • Kyogoku, Hideki;Ikeda, Tetsuya;Komatsu, Shinichiro
    • 한국분말야금학회:학술대회논문집
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    • 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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    • pp.81-82
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    • 2006
  • This paper presents the influence of the compositions of sintered Ti-Ni alloys on their thermo-mechanical properties. The Ti-Ni alloys having various compositions from 50at%Ni to 51at%Ni were sintered using elemental Ti and Ni powders by a pulse-current pressure sintering equipment. The deformation resistance in stress-strain curves increased with an increase in Ni content. In the case of Ti-50at%Ni, tensile strength and elongation were more than 500 MPa and 7%, respectively. The increase in Ni content also makes the transformation temperatures lower. The deformation resistance at a test temperature change from 293K and 353K in isothermal tensile test increased with elevating test temperature.

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Rheological properties of arabinogalactan solutions related to the carbohydrate composition of different legumes

  • Kyeongyee Kim;Choon Young Kim
    • 한국식품저장유통학회지
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    • 제30권5호
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    • pp.785-796
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    • 2023
  • The aim of this study was to elucidate chemical structures and rheological properties of arabinogalactans (AGs) isolated from three legumes including black gram (BG), great northern bean (GNB), and California small white bean (CSWB). The ratio of galactose to arabinose (G/A) in three legumes increased in the order of BG > GNB > CSWB. The rheological measurements of 1-5% (w/v) AG solutions revealed Newtonian and non-Newtonian flow behaviors. BG exhibited yield stress, indicating plastic behavior. Small-amplitude oscillatory tests indicated viscoelastic properties of BG, GNB, and CSWB ranging from solid-like, paste-like, and liquid-like behaviors, respectively. Small-strain oscillatory tests were conducted to assess the structure recovery of the AGs after pre-shearing. G" values of BG and GNB increased, but those of CSWB remained constant after shearing. These results suggest that the chemical structures of the AGs, particularly their G/A ratios, influence their rheological properties.

Effect of Acute Heat Stress on Heat Shock Protein 70 and Its Corresponding mRNA Expression in the Heart, Liver, and Kidney of Broilers

  • Yu, Jimian;Bao, Endong
    • Asian-Australasian Journal of Animal Sciences
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    • 제21권8호
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    • pp.1116-1126
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    • 2008
  • The objective of this study was to investigate the expression and localization of heat shock protein 70 (Hsp70) and its mRNA in the heart, liver, and kidney of acutely heat-stressed broilers at various stressing times. Male AA broilers (n = 100) were randomly divided into 5 groups of 20 birds per group. After 30 d of adaptive feeding at ambient temperature, 80 experimental broilers were suddenly heat stressed by increasing the environmental temperature from $22{\pm}1^{\circ}C$ to $37{\pm}1^{\circ}C$. The 4 groups were heat stressed for 2, 3, 5, and 10 h, respectively. The localizations of Hsp70 protein and mRNA, determined by immunohistochemical staining and in situ hybridization, respectively, were demonstrated to be tissue dependent, implying that different tissues have differential sensibilities to heat stress. Intense Hsp70 staining was identified in the vascular endothelial cell of heart, liver and kidney, suggesting an association between expression of Hsp70 in vascular endothelial cell and functional recovery of blood vessels after heat shock treatment. Ante-mortem heat stress had a significant effect on the expression of Hsp70 protein and mRNA. The quantitation of Hsp70 protein and mRNA were both time and tissue dependent. During the exposure to heat stress, the heart, liver and kidney of broiler chickens exhibited increased amounts of Hsp70 protein and mRNA. The expression of hsp70 mRNA in the heart, liver and kidney of heat-stressed broilers increased significantly and attained the highest level after a 2-h exposure to elevated temperatures. However, significant elevations in Hsp70 protein occurred after 2, 5, and 3 h of heat stressing, respectively, indicating that the stress-induced responses vary among different tissues.

침구치료 및 체질처방으로 호전된 복압성 요실금 환자의 증례 (Case report of the stress urinary incontinence which is improved by Acupunture treatment and Sasang Constitutional Herbal medication.)

  • 정소영;김동일
    • 대한한방부인과학회지
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    • 제20권4호
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    • pp.210-216
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    • 2007
  • 복압성 요실금의 의학적 치료는 비수술적 치료와 수술적 치료로 이루어지지만 비수술적 치료의 완치율은 20-50%로 낮게 보고되고 있으며, 수술적 치료의 완치율이 높아 최근 수술적 치료가 급격 히 증가하고 있다. 복압성 요설금의 수술요법은 비용과 시간 변에서 점차 개선되고는 있으나 여전히 후유증과 함께 침습적이라는 단점을 가지고 있다. 따라서 복압성 요실금에 대한 비수술적 치료의 완치율을 높이는 노력이 필요하다고 생각되어진다. 본 증례는 복압성 요실금을 진단받고, 수술 권유 받았으나, 수술에 대한 두려움으로 비수술적 치료를 받으시다가 그 치료 효과가 약하며, 지속적이지 못하고 재발하여 한의원에 내원한 환자로 침치료와 태음인(太陰人) 갈근승기탕류(葛根承氣湯類)의 한약 처방을 통하여 임상증상의 호전의 결과를 보여 보고하였다.

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AA5083 합금의 고온 변형시 유동응력 및 연신율에 미치는 온도와 변형 속도의 영향 (The Effects of Temperature and Strain Rate on Flow Stress and Strain of AA5083 Alloy during High Temperature Deformation)

  • 고병철;김종헌;유연철
    • 소성∙가공
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    • 제7권2호
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    • pp.168-176
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    • 1998
  • Hot workability of the AA5083 alloy ws investigated by torsion test at temperature ranges of $350{\sim}520^{\circ}C$ and strain rates of 0.5, 1.0, and 3.0/sec. The flow stress and hot ductility of the AA5083 alloy as a function of deformation variables such as temperature and train rate were studied. The microstructural evolution of the AA5083 alloy was studied in relation to Zener-Hollomon parameter (Z=exp( /RT) Also the hot restoration mechanism of the AA5083 alloy was small when Z val-ues were higher than $1.73{\times}1016/sec(370^{\circ}C,\;0.5/sec)$ In addition the difference microstructures during hot deformation. It was found that the increase of flow curves and deformed microstructures during hot deformation. It was found that the increase of flow stress of the AA5083 alloy was small when Z val-ues were higher than $1.73{\times}1016/sec(370^{\circ}C.\;0.5/sec)$. However under the low Z values less than $1.73{\times}1016/sec(370^{\circ}C,\;0.5/sec)$ the flow stress increase with increasing the Z values. The large dispersoid particles in the matrix grain decreased the flow strain of the AA5083 alloy because it caused the stress concentration during hot deformation.

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Methanol Extract of Longanae Arillus Regulates Sleep Architecture and EEG Power Spectra in Restraint-Stressed Rats

  • Ma, Yuan;Eun, Jae-Soon;Lee, Kwang-Seung;Lee, Eun-Sil;Kim, Chung-Soo;Hwang, Bang-Yeon;Oh, Ki-Wan
    • Natural Product Sciences
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    • 제15권4호
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    • pp.213-221
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    • 2009
  • Longanae Arillus (the rind of fruits of Dimocarpus longan) has been consumed for the treatment of insomnia and anxiety in Asia. To provide further scientific basis to traditional uses of this fruit on insomnia, we evaluated the effects of methanol extract of Longanae Arillus (MELA) on the alteration of sleep architecture and electroencephalogram (EEG) power spectra in acutely and chronically restraint-stressed rats. Following postsurgical recovery, Polygraphic signs of sleep-wake activities were recorded for 24 h after MELA administration in rats. Rats in the acute stress and chronic stress were administered with MELA for 10 days. On the $8^{th},\;9^{th}\;and\;10^{th}$ day of MELA administration, the rats were stressed for 3 h once per day. On the $10^{th}$ day and 1 h after MELA administration, the rats were stressed once for 22 h in the chronic stress group. Acute and chronic stress induced alternations in cortex EEG recordings during non-rapid eye movement (NREM), rapid eye movement (REM) sleep and wakefulness. MELA shortened the total and REM sleep and increased the wakefulness in night time recording without changing daytime recordings. Chronic stress increased wakefulness and REM sleep, decreased total and NREM sleep in the daytime recording, and increased REM and decreased NREM sleep without changing total sleep and wakefulness in night time recording. These findings suggest that MELA ameliorated the alterations in REM and NREM sleep of acutely and chronically stressed rats via modulation of cortical ${\alpha}-$, ${\theta}-$ and ${\delta}-$ wave activity.

Ginseng Extract Regulates the Alterations of Sleep Architecture and EEG Power Spectra in Restraint Stressed Rats

  • Ma, Yuan;Eun, Jae-Soon;Yang, Shulong;Lee, Kwang-Seung;Lee, Eun-Sil;Kim, Chung-Soo;Oh, Ki-Wan
    • Journal of Ginseng Research
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    • 제34권1호
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    • pp.30-40
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    • 2010
  • The present investigation was conducted to evaluate the regulation of sleep architecture by the red ginseng water extract (RGE) in acutely and chronically restraint stressed rats. Adult rats were fitted with sleep.wake recording electrodes. Following post-surgical recovery, rats were extensively habituated for freely moving polygraphic recording conditions. Polygraphic signs of sleep-wake activities were recorded for 24 h after RGE administration and induction of stress and were analyzed to understand the regulation of sleep architecture. Acute stress decreased wakefulness and increased total sleep, non-rapid eye movement (NREM) sleep, and rapid eye movement (REM) sleep in both the daytime and nighttime recording. RGE shortened the daytime NREM and REM sleep, without changing the wakefulness and total sleep. RGE increased nighttime wakefulness, and decreased total, NREM and REM sleep. Chronic stress increased wakefulness and decreased total sleep in the daytime recording, and increased REM and decreased NREM sleep in both the day and night time recording. RGE ameliorated chronic stress and induced alterations of REM and NREM sleep in the day and night time sleep architecture. Acute and chronic stress could also induce alternations in cortex electroencephalogram (EEG) recording during NREM, REM sleep and wakefulness. These findings suggest that RGE may modulate the sleep behavior in acutely and chronically stressed rats and the ameliorating effect of RGE on the sleep architecture may involve in modulation of $\alpha$-, $\theta$- and $\delta$- wave activities of the cortical EEG.

자가통증조절장치 (PCA) 사용자에서 향기흡입법이 자궁적출술 후 스트레스, 수면 및 오심과 구토에 미치는 효과 (Effects of Aromatherapy on Stress, Sleep, Nausea and Vomiting during Patient Controlled Analgesia Treatment of Patients with Hysterectomy)

  • 최정희;김윤미
    • 여성건강간호학회지
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    • 제19권4호
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    • pp.211-218
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    • 2013
  • Purpose: The purpose of study was to examine effects of aromatherapy on stress, sleep, nausea and vomiting of women after laparoscopic hysterectomy. Methods: The participants were 60 women who had laparoscopic hysterectomy: experiment group for aromatherapy (n=30) and control group for routine care (n=30). The experimental group received inhalation aromatherapy for 5 minutes, twice; the first was done right after the operation, the second was at 9 pm before sleep on the same day-while the control group had no inhalation. Data were collected from July to September, 2012 at G hospital. Results: The degree of psychological stress was not significantly different between two groups (t=-1.96, p=.054). Yet, there were significant differences between two groups for degree of physiological stress (t=-3.20, p=.002), the level of cortisol (t=-2.01, p=.049), the score of sleep status (t=2.47, p=.016), the score of sleep satisfaction (t=2.43, p=.018), and the score for nausea and vomiting (t=-2.58, p=.012). Conclusion: Inhalation aromatherapy using the mixed oil of lavender, mandarin, and marjoram was effective in decreasing the level of physiological stress, cortisol, and the score for nausea and vomiting, and also allowed the participants to have a better sleep. Therefore, inhalation aromatherapy could be effective in improving the quality of life of these women during recovery.

뇌질환아 어머니의 스트레스와 대처방법 (A Study on Stress and Coping Methods of Mothers of Children with Brain Disease)

  • 윤정희;조결자
    • 대한간호학회지
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    • 제24권3호
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    • pp.389-412
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    • 1994
  • This study was done to investigate stress and coping methods of mothers with brain disease children. The subjects for this study were obtained by taking a sample of mothers with brain disease children hospitalized in neurosurgery ward of K medical center in Seoul from Nov. 20, 1992 to Mar. 10, 1993. The collected date were analized by S.P.S.S. program(frequency, percentage, mean, t-test, ANOVA, Pearson Correlation). The results of the study were as follow. 1. The mean of the degree of mothers' stress was 3.681. Of the stress categories, illness treatment (4.216) was highest, and the next were in order of ill-ness status and prognosis(4.154) , family relation-ships and personal roles(3.202), interpersonal relationships(2.916). 2. The mean of the degree of mothers' coping method was 2.930. Of the coping method categories, communication with medical team or parents in similar situations(3.332) was highest, and the next were in or-der of family cooperation and optimistic thought about the situation(3.241), reforcement of self esteem and maintenance of psychological stability(2.538). 3. There was not seen a stastically significant correlation between stress factors and coping methods of mothers. But with categories, the higher the stress to illness status and prognosis was, the hight coping methods' degree of communication with medical team or parents in similar situations was shown a positive correlation, if not high (r=.2776, P=.046) . And the higher the stress to illness treatment was, the higher coping methods' degree of communication with medical team or parents in simial situations was shown a positive correlation, if not high (r=.2727, P=.049). 4. With the difference of stress according to mothers' general characteristics, religion and monthly income shew a statically significant difference. The mothers' group who have a religion shew the higher degree of stress(t=-3.17, P=.003), The group who get the most income shew highest degree of stress (F=.4693, P=.0156). With the difference of coping according to mothers' general characteristics, the most support-ing person, satisfaction with husbands and mothers' own health status shew a statistically significant difference. The group who get the most support from parents-in-law(F=3.7508, P=.013), the group who are much satisfied with husband(F=3.589, P=.016), and the group whose health status are good(F=3.3675, P=.046), shew the highest coping degree. 5. There were no significant difference in degree of stress and coping by children's characteristics The significance of the study will be concluded as follows. 1. Investigating the stress factors, which mothers are perceiving, it will be utilized as the basic materials of nursing plan so as to reduce the stress of mothers. 2. In searching for the ways of mothers' more helpful coping methods, it shows the necessity of the active nursing intervention for the mothers in the process of coping with their stress. That is, the nurse should serve the earnest nursing as counselor, supporter, educator, and information - provider. 3. Recogning mothers as well as children with brain disease as a client, the nurse will be able to help the mother, who is taking care of the children, cope with the stress situation well, and to make a contribution to the recovery, rehabilitation, and health of the children and to the enhancement of the family' health.

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산림환경 이용 빈도가 근로자의 스트레스에 미치는 영향: 의료 및 상담서비스기관 종사자에 대한 비교 연구 (Effect of Frequency of Using Forest Environment on Workers' Stress: a Comparative Study on Workers in Medical and Counseling Service Institution)

  • 정원희;우종민;유지수
    • 한국산림과학회지
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    • 제103권1호
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    • pp.129-136
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    • 2014
  • 본 연구는 산림환경 이용 빈도에 따라 근로자의 스트레스 수준에 어떤 차이가 있는지를 알아보고자 했다. 이를 위해 정서적 스트레스와 소진 경험이 많은 것으로 알려진 감정노동 직업군 중에서 연구대상자를 선정했다. 수도권 소재 의료기관과 상담기관의 직원 370명을 대상으로 사전 설문조사를 실시하여 산림이용 빈도에 따라 이들을 분류했다. 이후 캠프와 대조군 검사에 서면으로 참여의사를 밝힌 인원을 모집한 결과, 최종적으로 산림환경 이용 빈도가 높은 집단이 27명, 산림환경 이용 빈도가 낮은 집단 42명의 총 69명이 연구에 참여하였다. 이들을 대상으로 Worker's Stress Response Inventory (WSRI), Recovery Experience Questionnaire (REQ), Maslach Burnout Inventory-General Survey (MBI-GS)와 같은 심리사회적 변인과 심박변이도(heart rate variability), 코티솔(cortisol), 자연살해세포(Natural Killer cell) 등의 생물학적 변인 검사를 실시한 결과, 산림환경 이용 빈도에 따라 스트레스 수준에 차이가 나타나는 것을 확인할 수 있었다. 산림이용 빈도 "높음" 집단은 우울, 직무증상과 스트레스 반응 총점(WSRI)이 "낮음" 집단에 비해 유의미하게 적었으며, 스트레스에서의 회복경험 총점(REQ) 역시 통계적으로 유의하게 "낮음" 집단보다 높았다. MBI-GS의 정서적 고갈과 직업성취감 감소, 총점에서도 "높음" 집단이 유의하게 낮은 것을 확인할 수 있었다. 대부분의 다른 지표에서도 동일한 경향성이 관찰되었다. 생물학적 변인에서는 통계적으로 유의한 결과는 없었으나 "높음" 집단은 심박변이도의 SDNN 및 RMSSD, TP 지표와 자연살해세포 활성도에서 높은 수치를 나타내었고, 코티솔은 낮았다. 이 결과는 평소 산림환경을 자주 이용하는 사람들이 심리사회적인 스트레스가 낮고, 생물학적으로도 더 스트레스를 적게 받는 상태에 있음을 의미한다.