• Nuclear Engineering and Technology
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• 제56권6호
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• pp.2153-2162
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• 2024

The purpose of this study is to develop a high-energy neutron shielding material applied in proton therapy environment. Composite shielding material consisting of 10.00 wt% boron carbide particles (B₄C), 13.64 wt% surface-modified cross-linked polyethylene (PE), and 76.36 wt% tungsten particles were fabricated by hot-pressure sintering method, where the optimal ratio of the composite is determined by the shielding effect under the neutron field generated in typical proton therapy environment. The results of Differential Scanning Calorimetry measurements (DSC) and tensile experiment show that the composite has good thermal and mechanical properties. In addition, the high energy-neutron shielding performance of the developed material was evaluated using cyclotron proton accelerator with 100 MeV proton. The simulation shows a 99.99% decrease in fast neutron injection after 44 cm shielding, and the experiment result show a 99.70% decrease. Finally, the shielding effect of replacing part of the shielding material of the proton therapy hall with the developed material was simulated, and the results showed that the total neutron injection decreased to 0.99‰ and the neutron dose reduced to 1.10‰ before the enhanced shielding. In summary, the developed material is expected to serve as a shielding enhancement material in the proton therapy environment.

• The Korean Journal of Pain
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• 제36권4호
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• pp.441-449
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• 2023

Background: Hypertonic saline is used for treating chronic pain; however, clinical studies that aid in optimizing therapeutic protocols are lacking. We aimed to determine the concentration of intrathecally injected hypertonic saline at which the effect reaches its peak as well as the underlying γ-aminobutyric acid (GABA) receptor-related antinociceptive mechanism. Methods: Spinal nerve ligation (SNL; left L5 and L6) was performed to induce neuropathic pain in rats weighing 250-300 g. Experiment 1: one week after implanting the intrathecal catheter, 60 rats were assigned randomly to intrathecal injection with 0.45%, 0.9%, 2.5%, 5%, 10%, and 20% NaCl, followed by behavioral testing at baseline and after 30 minutes, 2 hours, 1 day, and 1 week to determine the minimal concentration which produced maximal analgesia. Experiment 2: after determining the optimal intrathecal hypertonic saline concentration, 60 rats were randomly divided into four groups: Sham, hypertonic saline without pretreatment, and hypertonic saline after pretreatment with one of two GABA receptor antagonists (GABA_A [bicuculline], or GABA_B [phaclofen]). Behavioral tests were performed at weeks 1 and 3 following each treatment. Results: Hypertonic saline at concentrations greater than 5% alleviated SNL-induced mechanical allodynia and had a significant therapeutic effect, while showing a partial time- and dose-dependent antinociceptive effect on thermal and cold hyperalgesia. However, pretreatment with GABA receptor antagonists inhibited the antinociceptive effect of 5% NaCl. Conclusions: This study indicates that the optimal concentration of hypertonic saline for controlling mechanical allodynia in neuropathic pain is 5%, and that its analgesic effect is related to GABA_A and GABA_B receptors.

• 핵의학기술
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• 제15권2호
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• pp.36-40
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• 2011

PET/CT 검사에서 환자에게 주입되는 $^{18}F$-FDG 투여량은 장비업체에서 제시하는 권고치와 각 병원에서 적용하는 기준치가 서로 다르다. 기준치의 차이로 인한 부적절한 $^{18}F$-FDG 투여량은 환자의 피폭선량을 증가시키고 영상의 질을 감소시킬 수 있다. 본 실험에서는 PET/CT 검사에서 영상의 질을 유지하면서 환자의 피폭선량을 감소시킬 수 있는 적정한 $^{18}F$-FDG 투여량에 대한 평가를 하고자 한다. 모형 실험은 NEMA NU2-1994를 이용하여 열소와 배후 방사능비를 4:1로 유지한 상태에서 열소의 방사능 농도를 1, 3, 5, 7, 9 MBq/kg으로 증가시키며 $^{18}F$-FDG를 주입하였다. CT를 이용한 투과촬영 후 2분 30초/bed의 방출영상을 3차원 (3D) 모드로 획득하였다. 열소와 배후방사능 부위에 각각 관심영역을 설정하고 최대 표준섭취계수(Standard Uptake Value maximum, $SUV_{max}$)를 얻은 후 해당 위치에서의 신호대 잡음비(Signal to Noise Ratio, SNR)를 비교 분석하였다. 임상실험은 2009년 11월부터 2010년 8월까지 내원한 환자를 대상으로 PET/CT 검사를 시행한 환자영상에서 간병변이 없는 97명의 환자를 선별하여 간(liver)과 대퇴부(thigh) 영역에 관심영역을 설정하고 $SUV_{max}$를 측정하여 투여량에 따른 영상의 차이를 비교 분석하였다. 모형 실험에서 단위 질량 당 주입된 방사능 농도는 1, 3, 5, 7, 9 MBq/kg으로 $SUV_{max}$는 23.1, 24.1, 24.3, 22.8, 23.6, SNR은 0.48, 0.54, 0.56, 0.55, 0.55로 나타났다. 5 MBq/kg 이하의 방사능 농도에서는 투여량의 증가에 따라 $SUV_{max}$와 SNR이 증가하지만 7 MBq/kg 이상에서는 감소하였다. 임상 실험의 경우는 단위 질량 당 주입된 방사능 농도가 4.72, 5.34, 6.16, 7.41, 8.68 MBq/kg으로 증가할수록 $SUV_{max}$는 2.68, 2.67, 2.26, 1.88, 1.95, SNR이 0.52, 0.53, 0.46, 0.46, 0.44로 5 MBq/kg의 투여량을 초과할 경우 모형 실험에서와 같은 감소양상을 보였다. 환자의 체중을 고려한 $^{18}F$-FDG 투여량의 증가는 일정 범위 내에서 영상의 질을 향상시키지만 그 범위를 초과할 경우 우발동시계수 및 산란계수의 증가로 인하여 오히려 영상의 질이 저하된다. 실험 결과로부터 3D PET/CT 검사 시 단위질량 당 주입된 방사능 농도 5 MBq/kg이 최적의 주입선량이라는 것을 알 수 있다.

• 한국임상수의학회지
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• 제19권4호
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• pp.418-425
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• 2002

Estrus was induced in 13 anestrus Korea Jin-do bitches by intramuscular injection of pregnant mare serum gonadotropin (PMSG) in a dose of 500 lU once daily for ten consecutive days, followed by an additional single intraveneous injection of 1,000 lU of human chorionic gonadotropin (hCG) on the tenth day. Day-changes of vaginal epithelial cells during the hormone treatment were investigated in each experimental bitches and compared with the those of spontaneous estrus bitches. The first days of vulval bleeding and male acceptance after PMSG treatment were on Day 6.0$\pm$ 1.5 (mean$\pm$ SD) and Day 9.0$\pm$ 1.9, respectively. And in all of 13 bitches, vulval swelling and perineal reflex were shown. The mean durations of proestrus and estrus were 2.9$\pm$ 1.4 (mean$\pm$ SD, range ; 1-6) and 11.5: 1.7 (range ; 8-14) days, respectively, that is, duration of proestrus was significantly shorter than that of the spontneous estrous bitches but duration of estrus was longer than that of the spontaneous estrous bitches. Characteristic features of vaginal cytology during the estrous cycle were the high proportions of large intermediate cell, superficial cell, anuclear cell and erythrocyte in proestrus, superficial cell and anuclear cell in estrus and parabasal cell, small intermediate, large intermediate cell, and leukocyte in diestrus, respectively. The comification index (Cl) was significantly high proportion in proestrus and estrus, when Day 0 was timed from the first day of male acceptance, the Cl was first increased above 80% on Day 0 and maintained above 80% until Day 0 to Day 5 during 6 days and showed a peak on Day 2. Also it was maintained above 90% until Day 2 to Day 3 during 2 days. These results indicated that all 13 ekperimental bitches showed positive estrus detection by the estrus behavior and vaginal smear test after treated with PMSG and hCC. It suggested that vaginal cytology was used to estimate the optimal mating and ovulation time, in consideration of the day when the Cl was maintained above 80% in estrus-induced Korea Jin-do bitches.

• The Korean Journal of Pain
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• 제20권2호
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• pp.169-173
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• 2007

Background: Although the use of intravenous patient controlled analgesia (IVPCA) has been compared to the use of patient conrolled epidural analgesia (PCEA), there is no optimal administration route of alfentanil for the treatment of postoperative pain. This randomized double-blind study compared the efficacy of the use of IVPCA and PCEA for postoperative pain and the side effects after a total abdominal hysterectomy (TAH). Methods: Sixty patients undergoing a TAH were randomly assigned to receive either IVPCA (Group I) or PCEA (Group E) for the infusion of alfentanil for postoperative pain control. In both groups, a loading dose of $750{\mu}g$ alfentanil was administered. All patients received the same continuous infusion rate (0.3 mg/h), bolus dose (0.15 mg), and lockout time (15 min). The incidence of side effects, the VAS (visual analog scale) of pain, blood pressure, and heart rate were checked for 20 hours after the loading dose injection. Results: The VAS of pain was not significantly different between the two groups of patients. The onset of the analgesic effect was significantly more rapid in the Group I patients than in the Group E patients. There was no difference in side effects for either group. Conclusions: When considering multiple factors such as the onset of analgesia, technical difficulties or infection after the procedure, IVPCA using alfentanil is more useful than PCEA for postoperative pain control after a TAH.

• 한국수정란이식학회지
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• 제28권4호
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• pp.307-314
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• 2013

Embryos formed in vivo were collected from 171 donors housed in Chung Cheong Buk-Do Institute of Livestock and Veterinary Research of the Chungbuk community during the years 2009~2012. We evaluated annual embryo collection, effect of follicle stimulating hormone (FSH), controlled internal drug release (CIDR) and prostaglandin (PG) administration to the donor for superovulation and controlling the estrus cycle, seasonal effects of embryo collection and compared the number of embryos recovered as per the collection days and pregnancy rate. In all, 1,243 embryos were collected from 118 donors with an average of $7.31{\pm}5.35$ embryos per donor, out of which 69.4% were transferable. Dosages of FSH required for inducing superovulation in various donors were compared. Average number of embryos collected from donors administered with 30 AU of FSH ($7.13{\pm}5.74$ per donor) was not significantly different from that of donors who were given an injection of 24 AU of FSH ($7.53{\pm}4.91$ per donor). However, the percentage of transferable embryos in the 30AU FSH-administered group (63.2 %, 449 of 711) was higher than that in the 24AU FSH-administered group (77.8%, 414 of 532). In the group of donors under a natural estrus cycle, the FSH dose administered did not influence the number of transferable embryos produced ($7.49{\pm}6.25$ per donor for 30 AU of FSH vs $7.49{\pm}4.92$ per donor for 24 AU of FSH). However, in donors administered with CIDR and PG for controlling the estrus cycle, the FSH dose affected the average number of transferable embryos collected ($4.25{\pm}2.87$ per donor for 30 AU of FSH vs $8.50{\pm}6.36$ per donor for 24 AU of FSH). We collected embryos from donors 6, 7 or 8 days after artificial insemination (AI). Results showed that the percentage of transferable embryos among those collected 8 days after AI was significantly higher than that among embryos collected 6 or 7 days after AI. Seasonal variations did not affect number of recovered embryos and pregnancy rates in natural estrus cycle and CIDR treatment groups (48.28% and 42.55%) but higher than pregnancy rate of frozen embryos (19.63%). These results indicated that administration of FSH beyond a threshold dose (at least 24 AU) has no beneficial effect on the production embryos and that collection of embryos 7~8 days after AI is optimal for embryo recovery. CIDR treatment induced superovulation in short term and had no influence on the natural estrus cycle. Finally, although good-quality embryos were transferred, freezing significantly reduced the pregnancy rates after transfer.

• Journal of Pharmaceutical Investigation
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• 제36권6호
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• pp.355-361
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• 2006

Intraarticular corticosteroid injections for therapy of rheumatic arthritis are administered with the aim of optimal local anti-inflammatory effect at the injection site. Since the side effects of corticosteroidal drug, dexamethasone(DEX), administered at hish dose limited the therapeutic efficacy, there was a need to design a new drug delivery system for controlled release of dexamethasone. As a prodrug for continuous therapeutic efficacy, dexamethasone-21-palmitate(DEX-PAL) was prepared via esterification of palmitoyl chloride and dexamethasone. DEX-PAL was identified by NMR and MASS analysis. DEX-PAL or DEX was entrapped in lipid nanosphere which could be prepared by using a self emulsification-solvent evaporation method. Physicochemical characteristics such as mean particle diameter, zeta potential and drug loading efficiency of the lipid nanospheres were investigated with variation of either the kind of lipid or the lipid composition. The lipid nanospheres had a mean diameter $83{\sim}95$ nm and DEX-PAL loading efficiency of up to 95%. The drug loading efficiency increased with the increase of aliphatic chain length attached to the phospholipid. The incorporation of cationic lipid was very efficient for both reducing particle size of lipid nanospheres and enhancing drug loading efficiency. The lipid nanospheres containing DEX-PAL may be a promising novel drug carrier for the controlled release of the poorly water-soluble drugs.

• Asian-Australasian Journal of Animal Sciences
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• 제28권1호
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• pp.135-142
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• 2015

This study was conducted to evaluate the effect of inclusion of propolis extraction residue in the feed of broilers from 1 to 21 d of age on phagocytic activity of macrophages, cutaneous basophil hypersensitivity response to phytohemagglutinin, antibody production against Newcastle disease, lymphoid organ weight and hematological profile and to determine the optimal level of inclusion. 120 chicks, reared in metabolism cages until 21 days of age, were distributed in a completely randomized design, with five treatments (0%, 1%, 2%, 3%, and 4% of propolis residue) and six replications. The relative weight of thymus and monocyte percentage were affected by propolis residue, with a quadratic response (p<0.05) and lowest values estimated at 2.38% and 2.49%, respectively. Changes in relative weight of cloacal bursa and spleen, percentage of lymphocyte, heterophil, basophil, eosinophil, and heterophil:lymphocyte ratio, antibody production against Newcastle disease, phagocytic activity of macrophages and the average number of phagocytosed erythrocytes were not observed. The nitric oxide production with regard to positive control (macrophages+erythrocytes) decreased linearly (p<0.05) with increased doses of propolis residue. The remaining variables of nitric oxide production (negative control - macrophages, and difference between the controls) were not affected by propolis residue. The cutaneous basophil hypersensitivity response to phytohemagglutinin as determined by the increase in interdigital skin thickness exhibited a quadratic response (p<0.05), which predicted a lower reaction response at a dose of 2.60% of propolis residue and highest reaction response after 43.05 hours of phytohemagglutinin injection. The inclusion of 1% to 4% of propolis extraction residue in broiler diets from 1 to 21 days of age was not able to improve the immune parameters, despite the modest changes in the relative weight in thymus, blood monocyte percentage, nitric oxide concentration, and interdigital reaction to phytohemagglutinin.

• The Korean Journal of Physiology and Pharmacology
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• 제27권5호
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• pp.481-491
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• 2023

The β subunits of high voltage-gated calcium channels (HGCCs) are essential for optimal channel functions such as channel gating, activation-inactivation kinetics, and trafficking to the membrane. In this study, we report for the first time the potent blood pressure-reducing effects of peptide fragments derived from the β subunits in anesthetized and non-anesthetized rats. Intravenous administration of 16-mer peptide fragments derived from the interacting regions of the β1 [cacb1(344-359)], β2 [cacb2(392-407)], β3 [cacb3(292-307)], and β4 [cacb4(333-348)] subunits with the main α-subunit of HGCC decreased arterial blood pressure in a dose-dependent manner for 5-8 min in anesthetized rats. In contrast, the peptides had no effect on the peak amplitudes of voltage-activated Ca²⁺ current upon their intracellular application into the acutely isolated trigeminal ganglion neurons. Further, a single mutated peptide of cacb1(344-359)-cacb1(344-359)_K357R-showed consistent and potent effects and was crippled by a two-amino acid-truncation at the N-terminal or C-terminal end. By conjugating palmitic acid with the second amino acid (lysine) of cacb1(344-359)_K357R (named K2-palm), we extended the blood pressure reduction to several hours without losing potency. This prolonged effect on the arterial blood pressure was also observed in non-anesthetized rats. On the other hand, the intrathecal administration of acetylated and amidated cacb1(344-359)_K357R peptide did not change acute nociceptive responses induced by the intradermal formalin injection in the plantar surface of rat hindpaw. Overall, these findings will be useful for developing antihypertensives.

• The Korean Journal of Physiology and Pharmacology
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• 제28권1호
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• pp.1-10
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• 2024

Type 2 diabetes mellitus (T2DM) is characterized by hyperglycemia and dyslipidemia. Carvacrol (CAR) has demonstrated the potential to mitigate dyslipidemia. This study aims to investigate whether CAR can modulate blood glucose and lipid levels in a T2DM rat model by regulating short-chain fatty acids (SCFAs) and the GPR41/43 pathway. The T2DM rat model was induced by a high-fat diet combined with low-dose streptozocin injection and treated with oral CAR and/or mixed antibiotics. Fasting blood glucose, oral glucose tolerance, and insulin tolerance tests were assessed. Serum lipid parameters, hepatic and renal function indicators, tissue morphology, and SCFAs were measured. In vitro, high glucose (HG)-induced IEC-6 cells were treated with CAR, and optimal CAR concentration was determined. HG-induced IEC-6 cells were treated with SCFAs or/and GPR41/43 agonists. CAR significantly reduced blood lipid and glucose levels, improved tissue damage, and increased SCFA levels in feces and GPR41/43 expression in colonic tissues of T2DM rats. CAR also attenuated HG-induced apoptosis of IEC-6 cells and enhanced GPR41/43 expression. Overall, these findings suggest that CAR alleviates blood lipid and glucose abnormalities in T2DM rats by modulating SCFAs and the GPR41/43 pathway.