• Title/Summary/Keyword: Stress pulse

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Experimental study on structural integrity assessment of utility tunnels using coupled pulse-impact echo method (결합된 초음파-충격 반향 기법 기반의 일반 지하구 구조체의 건전도 평가에 관한 실험적 연구)

  • Jin Kim;Jeong-Uk Bang;Seungbo Shim;Gye-Chun Cho
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.25 no.6
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    • pp.479-493
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    • 2023
  • The need for safety management has arisen due to the increasing number of years of operated underground structures, such as tunnels and utility tunnels, and accidents caused by those aging infrastructures. However, in the case of privately managed underground utility ducts, there is a lack of detailed guidelines for facility safety and maintenance, resulting in inadequate safety management. Furthermore, the absence of basic design information and the limited space for safety assessments make applying currently used non-destructive testing methods challenging. Therefore, this study suggests non-destructive inspection methods using ultrasonic and impact-echo techniques to assess the quality of underground structures. Thickness, presence of rebars, depth of rebars, and the presence and depth of internal defects are assessed to provide fundamental data for the safety assessment of box-type general underground structures. To validate the proposed methodology, different conditions of concrete specimens are designed and cured to simulate actual field conditions. Applying ultrasonic and impact signals and collecting data through multi-channel accelerometers determine the thickness of the simulated specimens, the depth of embedded rebar, and the extent of defects. The predicted results are well agreed upon compared with actual measurements. The proposed methodology is expected to contribute to developing safety diagnostic methods applicable to general underground structures in practical field conditions.

Study on Effect of Varience of Physiological Responses in Color Foot Reflexology Using Color Light (컬러광을 활용한 발반사요법이 인체 생리적 반응 변화에 미치는 영향에 관한 연구)

  • Jin, Hye-Ryeon;Yu, Mi;Park, Kyung-Jun;Kim, Nam-Gyun;Chung, Sung-Whan;Kim, Dong-Wook
    • Science of Emotion and Sensibility
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    • v.13 no.1
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    • pp.187-196
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    • 2010
  • Recently, people have been suffering from stress-related fatigue and psychological disorders. Most people depend on medicine for pain relief; many treat pain also through alternative medicine or replacement therapy. However, drug therapy has many side effects, including increased stress after the therapy. In comparison, alternative therapies such as massage and foot reflexology are less damaging to the body, and such therapies can be provided without physical or psychological discomfort. In this regard, the author had previously co-developed color foot reflexology, which combines the merits of color therapy and foot reflexology; color foot reflexology has been shown to have beneficial effects without undue pain. This study investigates the effects of color foot reflexology on the physiological response of the body by comparing the body’s response to the signal with that to the placebo. Healthy adult subjects were selected for the experiment, which was conducted under optimal experimental conditions and design. The results indicated that when stimulated, parasympathetic nerves increased in HRV and that blood pressure, pulse, body heat, peripheral blood flow were dramatically activated. However, the results for the placebo indicated minimal changes or irregular outcomes. The results provide strong evidence for the beneficial effects of the color foot reflexology instrument on the autonomic nervous system and on the physiological response of the body. Future research is warranted to verify the results of the current study by examining patients suffering from diseases and disorders arising from irregular physiological functions in the context of the foot.

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Cold Pressor Response to Seasonal Variation in Winter and Summer (국소한냉자극이 전신 및 국소혈액순환에 미치는 영향 -제 2 보 : 동계 및 하계의 계절변화에 따른 한냉반응-)

  • Park, Won-Gyun;Chae, E-Up
    • The Korean Journal of Physiology
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    • v.17 no.2
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    • pp.93-101
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    • 1983
  • A possibility whether the appearance of adaptation to cold climate during winter could occur or not in Taegu area was evaluated by comparing the data obtained in winter with that obtained by the same method in summer. Circulatory response was induced by the immersion of one hand in the cold water. The systemic and local responses in the blood circulation from the immersed hand and the unimmersed opposite hand were observed simultaneously. In addition Galvanic skin resistance(GSR) that is influenced by the activity of autonomic nervous system and the vascular tonicity was recorded. The experiment was performed by examining sixty healthy college students in winter and fifty in summer, whose mean age was 21.0, mean weight $60.6{\pm}0.90\;kg(male)$ and $48.3{\pm}0.98\;kg(female)$. The cold stimulus was applied by immersing the left hand into the cold water of $5^{\circ}C$ for 3 minutes, and the response was observed on immersed left hand and unimmersed right hand simultaneously. The observation was made through determining mean blood pressure, heart rate, amplitude of photoelectric capillary pulse (APCP) and GSR. The results obtained are as follows: The mean blood pressure was elevated during the cold stimulation. The increase of blood pressure in summer was more remarkable than in winter. At the recovery period the blood pressure was decreased to the control level in winter but the decrease below the control level was observed in summer. The increase of heart rate in summer was more remarkable than in winter during the cold stimulation. At the recovery period heart rate in both winter and summer was decreased below the control level. During the cold stimulation the APCP was decreased on both hands in winter. However it was more prominent on left hand indicating additional direct cold effect on immersed hand. In summer, the decrease of APCP during immersion was less remarkable than that in winter, but the regain of APCP was faster than that in winter at the recovery period. And the prompt increase of APCP over the control level has been obtained at the 3 minutes of the recovery period. The GSR was remarkably increased on immersed hand but slightly decreased on unimmersed opposite hand during the cold stimulation. Thus the finding on immersed hand indicates that the local direct effect of cold water is more prominent than the systemic effect, where as the finding on unimmersed hand indicates that the circulatory response to painful stress elicited by the cold stimulation is more prominent than cold temperature itself. In summary, it seems that the systemic circulatory response to the local cold stimulation of the one hand is arised more from the secondary elicited pain sensation and less from the low water temperature. On the contrary to the report of Kim et $al^{39)}$, the adaptation phenomena in blood pressure to the relatively mild cold climate in winter was not observed in this study. The difference of circulatory response observed in this study between winter and summer may be due to the difference of the magnitude of subjective sensation of the cold water stimulation by the seasonal changes in air temperature.

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ELASTIC CONSTANTS, SHEAR BOND STRENGTH OF TUNNEL RESTORATIVE MATERIALS AND MARGINAL RIDGE STRENGTH OF RESTORED TEETH (터널형 2급와동 충전재의 탄성계수와 전단결합강도 및 수복치의 변연융선 파절강도에 관한 연구)

  • Lee, Ka-Yean;Park, Yeong-Joon;Yang, Kyu-Ho
    • Journal of the korean academy of Pediatric Dentistry
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    • v.23 no.3
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    • pp.746-763
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    • 1996
  • An alternative design to conventional class II cavity preparation for proximal carious lesions is the tunnel preparation. It preserves the marginal ridge intact, thus making it possible to maintain the natural contact relationship with the adjacent tooth and minimize tooth reduction. This in vitro study was purposed to evaluate the effect of the materials' elastic constants and shear-bond strength on the marginal ridge fracture resistance of teeth restored by the tunnel technique, and to find the materials of choice for tunnel restorations. $Resinomer^{(R)}$, $Ketac-silver^{(R)}$, $Miracle-Mix^{(R)}$, and Tytin were used as restorative material. The elastic constants of each restorative material were evaluated by ultrasonic pulse measurement. Young's modulus and bulk modulus of the restorative materials were evaluated in three specimens for each material type. The shear-bond strength of the restorative materials to the dentin surface was measured after thermocycling 400 times between 6 and $60^{\circ}C$, using ten specimens for each material type. For measuring marginal ridge strength, 60 sound extracted molar teeth were distributed into six groups by size. Sound molar teeth were used as a Control group and unfilled prepared teeth were grouped as Unrestored. Another four groups were named Resinomer group, Ketac-Silver group, Miracle Mix group, and Tytin group by type of restorative material. Tunnel cavity preparation was done with ' 1/2, 2, and 4 round burs in sequence. Initial access to proximal surface was made through an occlusal access preparation started at least 2mm from the marginal ridge, and the proximal opening was formed about 2.5mm below the marginal ridge. After restoration and thermocycling, marginal ridge strength was measured using a universal testing machine. The results were as follows: 1. The Young's modulus of $Tytin^{(R)}$ was 63.95 GPa, followed by $Ketac-Silver^{(R)}$ 27.60 GPa, $Miracle-mix^{(R)}$ 18.48 GPa, and $Resinomer^{(R)}$ 10.74 GPa showing significant differences between the groups(P<0.05). The bulk modulus of the materials showed the same order as Young's modulus. The value of $Tytin^{(R)}$ showed 59.57 GPa indicating that it will deform less than other materials under the same stress. It was followed by $Ketac-Silver^{(R)}$ 23.57 GPa, Miracle $Mix^{(R)}$ 12.50 GPa, and $Resinomer^{(R)}$ 11.60 GPa. 2. The Resinomer group had a shear-bond strength of 7.41 MPa which was significantly higher than those of the Ketac-Silver group (1.80 MPa) and the Miracle Mix group (2.84 MPa) (P<0.01). All the specimens of Tytin group detatched from the dentin surface during thermocycling. 3. The mean marginal ridge strength of the Unrestored group(46.14 kgf) was significantly lower than that of the Control group (84.24 kgf) (P<0.01). The marginal ridge strength of teeth restored by the tunnel technique was, in order, Ketac-Silver group 74.06 kgf, Miracle Mix group 73.36 kgf, Resinomer group 63.47 kgf, and Tytin group 58.76 kgf. The Ketac-Silver, Miracle Mix, and Resinomer groups showed no significant difference with the Control group (P>0.05), but the Tytin group showed significantly lower strength compared to the Control group(P<0.05). The results showed that the marginal ridge strength of the teeth restored by the tunnel technique was not significantly lower than that of sound teeth. They also demonstrated that the bonding strength of the restorative material to the tooth surface should be high and the modulus of elasticity should not be lower than that of the tooth in order to restore the marginal ridge strength to its natural condition.

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A Literature Review of The Senile Hypotension (노인(老人) 저혈압(低血壓)에 대(對)한 문헌적(文獻的) 고찰(考察))

  • Kwak, Ik-Hoon;Kim, Jong-Dae;Jeong, Ji-Cheon
    • The Journal of Dong Guk Oriental Medicine
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    • v.4
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    • pp.161-187
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    • 1995
  • This study was perfomed to investigate causes of the senile hypotension, pathogenic mechanism, symptoms, and therapies through medical literatures, recent chinese medical literatures and chinese medical journals. The results are as follows ; 1. The senile hypotension has major symptoms of dizziness, weakness, syncope, palpitation, shortness of breath, and deficiency of Qi. Additionally, it has minor symtoms of letharhy, isomnia, tinnitus, amnesia etc... 2. The prodromal symptoms of Kwul and Kwul are relating to the symptoms of tachycardia, facial pallor, sweating, anxietas, ambiguous consciousness, and fainting. Weakness and dizziness due to deficiency make the symptoms of exhaustion, fatigue, vertigo, lethargy, and brachycardia. 3. The most principal cause of the senile hypotension is deficiency of Shen due to aging, congenital deficiency, and chronic illness. The rest of causes are defciency of Qi and blood, phlegm of retention, stagnation of Qi, blood stasis, blood prostration etc... In the view of the occidental meicine, the causes of the senile hypotension came from the reduction of cardiac output, the decretion of cardiovascular system's extention due to aging, hereditary factor, secondary factor due to exsanguination, diabetes mellitus, C.V.A etc..., and factor of neurogenic system's degeneration. 4. The principal pathogenic mechanisms are the insufficiency of Xing-Yang, the deficiency of Qi in middle jiao, and deficiency of Shen-Qi. The rest of mechanisms are the deficiency of both Qi and blood, stagnation of the Gan-Qi, and the deficiency of Gan and Shen. Zang-Pu Organs have something to do with Xing, Bi, and Shen. 5. As principal therapies, there are warming and recuperation the Xing-Yang, strengthing the middle-jiao and replenishing Qi, replenishing vital essence to tonify the Shen, and warming and recuperation the Shen-Yang. Additionally, the therapies of invigorating the Bi and relieving mental stress, strengthning the Bi and tonifing the Shen, invigorating Qi and nourishing Yin, soothing the Gan and regulating the circulation of Qi, and tonifing the Shen and nourishing the Gan help the cure of the senile hypotension. In prescriptions there are Baohe Yuan Tang, Buzhong Yigi Tang, Zuoguei Yin, Yougui Yin, Guipi Tang, Zhu Fu Tang, Shengmai San, Sini San, and Qi Ju Dihuang Wan. The medical herbs of Astragali Radix, Codonopsitis Pilosulae Radix, Ginseng Radix, Aconiti Tuber, Ephedrae Herba, Cinnamomi Ramulus, Cinnamomi Corfex Spissus, Zingiberis Rhizoma, Polygalae Radix, Liriopis Tuber, Polygonati Sibirici Rhifoma, Lycii Fructus, Schizandrae Fructus, and Glycyrrhizae Radix can be treated. 6. According to the clinical report, the principal causes are the deficiency of Qi, and insufficiency of Yang which symptoms are dizziness, vitality fatigue and acratia, amnesia, body cold and alger of extremity, spontaneous perspiration, and therady and weak pulse. It was improved by taking WenYang YiQi Tang, Zhu Fu Tang about 20-30 days. The improvement was shown on disappearance of subjective symptoms or the ascending of blood pressure to normal figure, and the rate of improvement was over 70%. 7. As regimens, taking warming and recuperating food(a sheep mutton, juglans regia, chiness date, longan aril etc...) and pungent food(chinese green onion, fress ginger, pipers fructns etc...), doing physical training, not being ill in bed at a long time, and preventing descent of blood pressure coming from sudden change of posture are needed. Additionally, the usage of diuretic, abirritant, and depressor needs to be extra cautious.

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The Effect of Aerobic Exercise on Body Composition, Cardiopulmonary Function, Serum Lipid and Antioxidants of Obese College Female Students (에어로빅운동이 비만여대생의 신체조성, 심폐기능, 혈청지질 및 항산화물질에 미치는 영향)

  • Jung Eun-Sook;Park Hyeong-Sook
    • Journal of Korean Academy of Fundamentals of Nursing
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    • v.5 no.1
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    • pp.125-141
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    • 1998
  • The purpose of this research is to analyze the effects of aerobic exercise on body composition, cardiopulmonary function, serum lipid level and antioxidants of obese and normal college female students. The subject group was made up of 13 normal students (below 30% body fat ratio) and 12 obese students (above 30% body fat ratio). After a pretest, the subjects were given an 8-week aerobic program. Then the subjects were given a posttest and analyzed of body composition, serum lipid level, antioxidants and cardiopulmonary function after the 6th and the 8th week of the program. The program schedule was made up of 4 days per week, 60 minutes per day. Test includes B.W., subscapular and triceps subcutaneous fat thickness, change of respiratory gas, and two blood sampling before treadmill exercise and post all out state, which analyzed serum lipid and antioxidants. The subjects performed treadmill exercise starting with 4km/hr of walking and then gradually increase the speed of 1km/hr per minute until all out state. The obtained data were analyzed using SAS program. The statistical methods employed here were one-way ANOVA with repeated measure, Duncan Multiple range test, paired-t test and t-test. The test results and conclusion of this research were as follows. 1. The effects of aerobic exercise on body composition were as follows ; Percent body fat was significantly reduced 6 weeks after the program and lean body mass was significantly increased 8 weeks after the program in both groups(obese group: F=3.44 P=.044, normal group: F=3.30 P=.048). subscapular skinfold of the obese group showed a remarkable decrease after the 6th week(F=4.33 P=.021) triceps skinfold of the normal group showed a remarkable decrease after the 6th and the 8th week(F=4.55 P=.017) compared with readings before the aerobic program, the aerobic program made a bigger difference concerning body fat, lean body mass, subscapular skinfold in the obese group than in the normal group(t=2.41 P=.024, t=2.40 p=.025, t=2.43 p=.028). 2. The effects of aerobic exercise on cardiopulmonary function were as follows ; Maximal $O_2$ uptake/kg was significantly increased 6 weeks after the program in the obese group(F=3.20 P=.054), but not much difference was observed in the normal group. Maximal pulse rate was significantly reduced in both groups after 6 weeks of the program(obese group: F=2.77 P=.087, normal group: F=7.17 P=.001). 3. The effects of aerobic exercise on serum lipid level were as follows ; In a resting period, total cholesterol, Triglyceride, and LDL-cholesterol were slightly higher in the obese group than in the normal group, but HDL-cholesterol was higher in the normal group. But, with the aerobic program, total-cholesterol, Triglyceride, LDL-cholesterol were reduced gradually and HDL-choleterol got increased in both groups, but not much change was noticed in the normal group. However, in the obese group, serum HDL-cholesterol level got increased significantly(F=5.12 P=.012). 4. The effects of aerobic exercise in serum antioxidants were as follows ; In a resting period, the obese group's serum Free Radical and GSSG content were higher than the normal group's and the normal group's serum GSH content was higher than the obese group's. After 6 weeks of the aerobic program, Free Radical was reduced significantly in both groups(obese group: F=13.87 P=.000, normal group: F=18.60 P=.000) In the obese group, 8 weeks after the program, GSH was increased significantly(F=13.78, P=.000). In the normal group, 6 weeks after the program, GSH was reduced but increased again after 8 weeks(F=6.07 P=.005). Plasma GSSG was significantly increased after 8 weeks of exercise in both groups(obese group: F=19.75 P=.000, normal group: F=22.42 P=.000,) Compared with readings before the aerobic program, the aerobic program made a bigger difference serum GSH in the normal group than in the obese group(t=3.37 p=.003). As this result shows, it is known that the regular aerobic exercise improves cardiopulmonary function, body composition, serum lipid effectively and through the serum Free Radical reduction and antioxidant system activation, oxidant stress was suppressed. This effect was higher in the obese group than in the normal one. At least 6weeks exercise period need for improvement of body composition, cardiopulmonary function and activation of antioxidant system. This result suggest that improvement of serum lipid profile was needed longer than 8weeks exercise period.

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Effect of Geijibokryunghwan and each constituent herb on inhibition of platelet aggregation (계지복령환(桂枝茯笭丸) 및 그 구성약물(構成藥物)의 혈소판응집억제(血小板凝集抑制)에 관(關)한 연구(硏究))

  • Kim, Jong-Goo;Park, Sun-Dong;Park, Won-Hwan
    • The Journal of Dong Guk Oriental Medicine
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    • v.8 no.2
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    • pp.115-129
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    • 2000
  • The cause that the increase of animality fat intakes, under exercise, fatness, adding the stress, advanced age etc., the occurrence rate of the circulation system disease has been increased. And the thrombosis importantly came to the front as the risk factor of these circulation system's disease. Nowadays, the ischemic disease has especially discussed, for example the angina or myocardial infarction, originated in thrombosis that came from the platelet aggregation. In the western medicine, as the cure and prevention, using the aspirin or ticlopidine for platelet aggregation suppressant. But in the , the curing method must be used properly according to the pectoralgia or heartache's kind, state, grade. The platelet do not attache to the normal hemangioendothelial cell. But when it stimulated by endothelium peronia and so on, it attache to the injury endothelium or rise aggregation between the platelet. On this time, it secrete the platelet aggregation inducer as like ADP, thromboxane A2 from the inside of platelet. So it has first defensive function through the aggregation augment that prevent the celerity consumption of blood. But the activation of abnormal platelet occur the platelet grume and thrombogenesis. So it bring up the occlusive angiosis, so to speak, cardiovascular disease, cerebrovascular disease, arterial sclerosis. In oriental medicine, the thrombosis in the category of blood stasis and this blood stasis present the generalise or local blood circulation disturbance that generated by all kinds of pathological fact or blood stream retention accompanying with a series of syndrome. As the syndrome, stabbing pain fixed at certain region, squamous and dry skin, fullness and pain of the chest and hypochondrium, firmness and fullness of the lower abdomen, black stool, dark purple tongue or with ecchymoses and petechiae etc.. has been created. And it becomes the pathopoiesis cause that the convulsion and palpitation, severe palpitatiion, tympanites, the symtom complex with a mass or swelling in the abdomen, insanity, stricken by wind etc.. Moreover, it used the drugs for invigorating blood circulation and eliminating blood stasis or drugs for removing blood stasis for all kinds of syndrome through the blood stasis. And the drugs for activating the blood circulation, such as Salviae Radix, Angelicae Sinensis Radix, Persicae Semen, Achyranthis Radix, Cnidii Rhizoma, Carthami Flos are used for that. And it is used to the herbs of insects that has strong effect about the disintergrating blood stasis such as Hirudo, Scolopendrae Corpus, Buthus, Lumbricus etc.. On this study, It used Geijibokryunghwan(GBH) and the consisting herbs to investigate the influence of platelet aggregation about drugs that used to improvement various symptoms created by the thrombosis in oriental medicine. GBH formula has as formula recorded in the , action of 'eleminating the evil and not impairment of healthy energy' and 'promoting the flow of QI and cold and heat, so used for the expel blood stasis herbs from the ancient. Therefore we investigated the restraint effect of GBH and the consisting herbs about the platelet agregation induced to the ADP, AA or collagen. The conclusion is following. 1. When it added the aggregation inducer after that it added GBH and individual consisting herbs in the PRP, GBH showed the (+) inhibition effect on the platelet aggregation and it showed the (+) inhibition effect in the individual consisting herbs as like Paeoniae Radix and Moutan Cortex Radicis. 2. It showed the (+), (+,++) inhibition effect on the platelet aggregation in Paeoniae Radix Hoelen, Paeoniae Radix Moutan Cortex Radicis, Hoelen Moutan Cortex Radicis etc. 3. In the aggregation inhibition activating on the difference of density, GBH showed strong inhibition effect to the aggregation state induced to collagen, and it showed the inhibition effect in the individual consisting herbs as like Paeoniae Radix and Moutan Cortex Radicis about the aggregation induced by the collagen. 4. It showed the strong inhibition effect about the aggregation induced by the collagen in Paeoniae Radix Hoelen, Paeoniae Radix Moutan Cortex Radicis, Hoelen Moutan Cortex Radicis etc Like this, as confirm GBH and the individual consisting herb's inhibition effect of platelet aggregation, We considerated that GBH and the individual consisting herbs have practical applicational value of clinical trial in the thrombosis caused by platelet aggregation.

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