• The Korean Journal of Pain
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• 제3권2호
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• pp.119-124
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• 1990

Reiestad and Stromskag recently introduced the interpleural installation of local anesthetic solutions as a technique for the management of postoperative pain in patients undergoing cholecystectomy, renal surgery, and breast surgery. This study was done to manage postoperative pain in the patients undergoing unilateral upper-abdominal surgery and thoracotomy. Twenty patients received 0.5% bupivacaine 20 ml with epinephrine (Children, received 10 ml). Results were as follows: 1) Analgesic effects appeared in 15.56 minutes; mean analgesic duration from the initial intrapleural injection was 10.5 hours. 2) Blood pressure increased more after the operation than before the operation. Blood pressure before injection of bupivacaine was highest (p<0.01). Heart rate was increased before injection and 10 minutes after injection of 0.5% bupivacaine (p<0.05). 3) The values of $PaCO_2$, were improved from $41.7{\pm}2.02\;mmHg$ ($PaCO_2$), $85.2{\pm}2.41\;mmHg$ ($PaO_2$) to $37.8{\pm}2.41\;mmHg$ ($PaCO_2$), $107.0{\pm}7.86\;mmHg$ ($PaO_2$) respectively (p<0.01). 4) Complication such as pneumothorax, atelectasis and CNS toxicity did not appear. 5) Intrapleural administration of local anesthetics after unilateral upper-abdominal and thoracic surgery provided a satisfactory pain control.

• 한국분무공학회지
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• 제6권1호
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• pp.25-34
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• 2001

Several efforts to meet the exhaust gas regulation have been undertaken by many researchers in recent years. Main researches are on development of design techniques of intake port and combustion chamber, atomisation of fuel and precise control of air-fuel ratio, post-treatment of exhaust gas and so on. Engine technology is changed from PFI to GDI to correspond with exhaust gas regulation. GDI technique makes it possible to preserve lean air-fuel ratio and control accurate air-fuel ratio. Nevertheless, It is not cleared that information of spray characteristics and atomization process are very dependent on fluctuation of pressure and change of temperature in intake stroke. In this study, a constant volume combustion chamber is manufactured to investigate various fluctuations of in-cylinder pressure for injection duration. It is taken photographs of injection process of conventional GDI injector using PMAS. Then, it was verified experimently that ambient conditions as temperature and pressure of combustion chamber have effects on process of spray growth and atomization of fuel.

• 한국분무공학회지
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• 제15권3호
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• pp.115-123
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• 2010

The purpose of this study is to compare and to investigate spray characteristics of dimethyl ether (DME) and diesel fuel in the various injection pressures, ambient pressures, and the energizing durations. For the analysis of the spray characteristics, the spray visualization system including the high speed camera and the spray image analyzer is installed. The spray characteristics such as the spray development process, spray tip penetraion and the spray cone angle are analyzed from the spray images. It was revealed that the spray characteristics of DME and diesel fuels are mainly affected by the injection conditions. However, in the region after the end of the injection, the spray tip penetration was affected by the fuel properties such as the fuel density, the surface tension, and the viscosity. DME fuel has generally a short tip penetration and a wide cone angle. In the elevating conditions of the ambient gas pressure, the spray cone angle of DME fuel converged to high value when comparing diesel fuel in advance. Also, the increasing rate of the spray tip penetration in DME fuel is significantly decreased from 0.7 ms of the energizing duration (diesel : 0.9 ms).

• Journal of Mechanical Science and Technology
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• 제14권10호
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• pp.1143-1150
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• 2000

The effects of ambient conditions on vaporizing sprays from a high-pressure swirl injector were investigated by an exciplex fluorescence method. Dopants used were 2% fluorobenzene and 9% DEMA (diethyl-methyl-amine) in 89% solution of hexane by volume. In order to examine the behavior of liquid and vapor phases inside of vaporizing sprays, ambient temperatures and pressures similar to engine atmospheres were set. It was found that the ambient pressure had a significant effect on the axial growth of spray, while ambient temperature had a great influence on the radial growth. The spatial distribution of vapor phase at temperatures above 473K became wider than that of liquid phase after half of injection duration. From the analysis of the area ratio for each phase, the middle part (region II) in the divided region was the region which liquid and vapor phases intersect. For liquid phase, fluorescence-intensity ratio was greatly changed at lms after the start of injection. However, the ratio of vapor phase was nearly uniform in each divided region throughout the injection.

• 융복합기술연구소 논문집
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• 제8권1호
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• pp.9-13
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• 2018

The purpose of this study is to investigate the liquid- and vapor-phase spray characteristics, such as spray tip penetration and spray angle using gasoline direct injection (GDI) injector with multi-hole. The vapor-phase spray was captured by the Schlieren visualization system, which consists of high-speed camera, LED lamp, concave mirrors, and knife-edge. The liquid-phase spray was visualized by Mie-scattering techniques. Both spray images of vapor- and liquid-phase were visualized under 373 K of ambient temperature, 1 bar of ambient pressure, and 100/200 bar of injection pressure. The energizing duration was fixed at 1.5 ms. From the analysis of experimental results, it revealed that the increased injection pressure induced an early vaporization due to the improvement of droplet atomization. The spray tip penetration and spray angle in vapor-phase were higher than those in liquid-phase. The difference in the spray tip penetration between vapor- and liquid-spray gradually increased with the time elapsed after the injection. Even with the spray angle characteristics, it was found that the difference between the spray angle of liquid and vapor spray gradually grew after they entered steady-state conditions.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제27권3호
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• pp.276-282
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• 2005

Inferior alveolar nerve block using lidocaine is the most frequent local anesthetic method in the dental treatment, but clinically it is not always successful. The 2% lidocaine cartridge has been used commonly in dental anesthesia. It contains vasoconstrictor and antioxidant, which presents low pH which provides chemical stability and longer shelf life. But alkalinized local anesthetics has less tissue trauma, easier dissociation of the non-ionized base which penetrates nerve sheath, rapid onset and more intensity. In this study, in inferior alveolar nerve block, alkalinized lidocaine using sodium bicarbonate (experimental group) is compared with plain lidocaine (control group) about injection pain, anesthetic onset, duration and postinjection discomfort. In inferior alveolar nerve block, alkalinized lidocaine using sodium bicarbonate showed lower injection pain. There was significant difference statistically from plain lidocaine(p=0.019). Comparing with plain lidocaine, alkalinized lidocaine produced more rapid onset (lip & pulp anesthetic onset), there was no significant difference(p>0.05). but there was boundary significance (0.050.05). These results suggest that addition of sodium bicarbonate to 2% lidocaine(1:100,000 epinephrine) for inferior alveolar nerve block is more effective for reduction of injection pain and onset time.

• Journal of Dental Anesthesia and Pain Medicine
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• 제20권4호
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• pp.233-240
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• 2020

Background: Palatal injection of local anesthetics is the most painful injection. To obviate the need for palatal injections, local anesthetic agents with diffusibility are being investigated. Hence the present study was designed to analyze the anesthetic efficacy of 2% lidocaine hydrochloride (HCl) with 1:100,000 adrenaline and 4% articaine hydrochloride (HCl) with 1:100,000 adrenaline using single buccal infiltration for the extraction of maxillary premolars. Methods: A prospective, double-blind, crossover, randomized clinical study was performed on 60 consecutive systemically healthy patients with an age range of 15-30 years, requiring extraction of asymptomatic bilateral maxillary premolars for orthodontic purposes. They received 1ml buccal infiltration of 4% articaine HCl with 1:100,000 adrenaline on one side and 2% lidocaine HCl with 1:100,000 adrenaline on the other side. The extraction procedure on either side was scheduled 14 days apart. Parameters assessed were the time of onset of anesthesia, intraoperative discomfort, hemodynamic parameters, and the duration of analgesia. Analysis of the data was done using the Mann-Whitney test, the Wilcoxon test, the Kruskal-Wallis ANOVA test, and the chi-square test. Statistical significance was established at P < 0.05. Results: Articaine showed a faster time of onset and longer duration of analgesia than lidocaine. However, the difference in the intraoperative discomfort and hemodynamic parameters was statistically insignificant. Conclusion: Within the limitations of the study, it can be concluded that the extraction of maxillary premolars can be performed with a single buccal infiltration of 2% lidocaine HCl with 1:100,000 adrenaline, which is one of the most commonly used local anesthetic agent.

• International Journal of Oral Biology
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• 제36권2호
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• pp.43-50
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• 2011

Voltage dependent calcium channel (VDCC), one of the most important regulator of $Ca^{2+}$ concentration in neuron, play an essential role in the central processing of nociceptive information. The present study investigated the antinociceptive effects of L, T or N type VDCC blockers on the formalin-induced orofacial inflammatory pain. Experiments were carried out on adult male Sprague-Dawley rats weighing 220-280 g. Anesthetized rats were individually fixed on a stereotaxic frame and a polyethylene (PE) tube was implanted for intracisternal injection. After 72 hours, 5% formalin ($50 \;{\mu}L$) was applied subcutaneously to the vibrissa pad and nociceptive scratching behavior was recorded for nine successive 5 min intervals. VDCC blockers were administered intracisternally 20 minutes prior to subcutaneous injection of formalin into the orofacial area. The intracisternal administration of 350 or $700{\mu}g$ of verapamil, a blocker of L type VDCC, significantly decreased the number of scratches and duration in the behavioral responses produced by formalin injection. Intracisternal administration of 75 or $150 \;{\mu}g$ of mibefradil, a T type VDCC blocker, or 11 or $22\; {\mu}g$ of cilnidipine, a N type VDCC blocker, also produced significant suppression of the number of scratches and duration of scratching in the first and second phase. Neither intracisternal administration of all VDCC blockers nor vehicle did not affect in motor dysfunction. The present results suggest that central VDCCs play an important role in orofacial nociceptive transmission and a targeted inhibition of the VDCCs is a potentially important treatment approach for inflammatory pain originating in the orofacial area.

• Journal of Yeungnam Medical Science
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• 제2권1호
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• pp.39-44
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• 1985

상복부 수술후 진통을 위하여 경막외 narcotics 주입시 임상에서 경막외강 천자가 가장 많이 시술되고 있는 부위 안 요부 경막외강에 morphine과 demerol을 각각 주입하여 진통 효과를 관찰하였다. 전신 마취하에서 상복부 수술을 받은 환자 20명을 대상으로 하여서 morphine 1 mg을 주입한 10명의 I군, demerol 10mg을 주입한 10명의 II군에서의 진통 효과를 관찰하였던 바 다음과 같은 결론을 얻었다. 1. Morphine 을 주입한 I군에서는 평균 진통 시간이 29.4시간이었다. 2. Demerol을 주입한 II군에서는 평균 진통 시간이 4.0시간이었다. 3. Morphine을 주입한 I군이 Demerol을 주입한 II군보다 진통 시간이 훨씬 길었으며 통계학적으로 유의하였다. (P<0.05) 이상의 결과로 보아 상복부 수술후 진통 목적으로 마약제를 경막외강에 투여시 시술이 안전한 요부 경막외강내로 투여하여도 우수한 진통효과를 얻을 수 있으며 마약제로는 morphine의 투여가 demerol의 투여보다 더욱 진통 효과가 우수한 것으로 사료된다.

• Archives of Plastic Surgery
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• 제37권6호
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• pp.795-800
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• 2010

Purpose: According to various medical publications, it is believed that epinephrine should not be injected in fingers. However numerous articles show the successful use of local anesthetic with epinephrine in the digits. Epinephrine-mixed lidocaine solution enables to maintain a bloodless field for operation and provides long duration of local anesthesia when patient was wide awake. Methods: From May 2009 to December 2009, ten patients underwent flexor tendon reconstruction with local anesthesia using epinephrine. No tourniquet was necessary. Before operation, all patients were injected with local anesthetics using 1% lidocaine 20 mL and 0.1% epinephrine 0.1 mL. Results: There was no case of digital necrosis nor gangrene in the epinephrine injection. All 10 patients actively could move the finger through a full range of motion. All procedures were performed without sedation nor tourniquet and we could obtain a good vision of operative field and patients were comfortable. The patient make his or her fingers move through a full range of active motion before the skin is closed. Phentolamine was not required to reverse the vasoconstriction in any patients. Conclusion: The assertation that epinephrine should not be injected into the fingers is clearly no longer valid. The epinephrine injection allowed the authors to adjust flexor tendon surgery without risks associated with general anesthesia. It also enables to ensure longer anesthetic duration and bloodless operative field, and prevent post operative complications. In case of flexor tendon surgery, the use of epinephrine injection is recommended because of the advantages of local anesthesia.