• Archives of Pharmacal Research
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• v.28 no.8
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• pp.930-935
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• 2005

We have investigated the effects of relatively high concentration of carbachol (CCh), an agonist of muscarinic acetylcholine receptor (mAChR), on cardiac automaticity in mouse heart. Action potentials from automatically beating right atria of mice were measured with conventional microelectrodes. When atria were treated with $100{\mu}M$ CCh, atrial beating was immediately arrested and diastolic membrane potential (DMP) was depolarized. After exposure of the atria to CCh for $\~4 min$, action potentials were regenerated. The regenerated action potentials had lower frequency and shorter duration when compared with the control. When atria were pre-exposed to pirenzepine $(1{\mu}M)$, an $M_1$ mAChR antagonist, there was complete inhibition of CCh-induced depolarization of DMP and regeneration of action potentials. Pre-exposure to AFDX-116 (11 ({2-[(diethylamino)-methyl]-1-piperidyl}acetyl)-5, 11-dihydro-6H-pyridol[2,3-b][1,4] benzodiazepine-6-one base, $1{\mu}M$), an $M_2$ mAChR antagonist, failed to block CCh-induced arrest of the beating. However, prolonged exposure to CCh elicited gradual depolarization of DMP and slight acceleration in beating rate. Our data indicate that high concentration of CCh depolarizes membrane potential and recovers right atrial automaticity via $M_1$ mAChR, providing functional evidence for the role of $M_1$ mAChR in the atrial myocytes.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.35 no.1
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• pp.18-24
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• 2013

Purpose: This study is performed to determine the effects of titanium cap with various sizes of pores on bone formation during guided bone regeneration (GBR). Methods: Calvaria from 10 adult male rabbits were chosen as the recipient sites. A trephine bur with a diameter of 10 mm was used to form one round groove on each side of sagittal suture of the cranium, and a round bur with a diameter of 1.5 mm was used to form 6 small holes on the inner circles of round grooves to induce bleeding. In the control group, bone graft was not conducted, and closed titanium cap was fixed in the round groove. Bone graft was not performed in groups 1 and 2, but fixed on titanium caps with 0.2 mm, and 0.5 mm sized pores, respectively. For groups 3, 4, and 5, a synthetic bone graft material (${\beta}$-tricalcium phosphate, Cerasorb$^{(R)}$, Germany) was transplanted, and titanium caps without pore, with 0.2 mm and 0.5 mm sized pore were fixed, respectively. The animals were sacrificed 4 weeks after, and clinical, radiographical, and histomorphometrical evaluation of bone regeneration was performed. Results: In all groups, there were no clinical signs of infection, inflammation or wound dehiscence. Radiographic evaluation revealed well-defined semi-circular radiopacity inside the titanium cap of groups 3, 4, and 5. Histologically, the inner surface of the hemisphere was evenly lined with newly formed bone tissue, as well as grafted bone material in the group 3. In groups 4 and 5, the insertion of connective tissue was observed along the inner surface. However, the overall surface area between the grafts with different holes yielded no statistical significance in the histomorphometrical evaluation. Conclusion: Although the total area of newly formed bone showed no significant difference, excellent bone formation tendency was observed histologically when closed caps were used with bone graft was accompanied.

• Journal of Periodontal and Implant Science
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• v.25 no.3
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• pp.603-613
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• 1995

The purpose of this investigation was to evaluate on the biodegradability, biocompatibility and tissue regenerative capacity of synthetic bioabsorbable membranes in beagle dogs. For animal study, 9 adult beagle dogs were used to examination, on the surgical implantation of membranes and histological analysis. In each animal, the 3rd and 4th premolars of the both sides of the mandible were selected as test teeth. Two types of bioresorbable membranes including "Guidor membrane", "S-membranes" were used to examining for biological activity, and also Gore-tex membranes was used for positive control. Surgically created defects were made in 2 premolars of both sides of the mandible at $3{\times}4mm^2$ in size and tested membranes were implanted in the defected area. A plaque control regimen was instituted with daily tooth brushing with a 0.1% chlorhexidine digluconate during experimental periods. All the experimental animals were sacrificed after 2, 4, and 8 weeks from surgery and undecalcified slides were prepared using the "sawing and grinding" technique described by Donath and Breuner". In biodegradability, all the membranes were started their biodegradation from two weeks after implantation and gradually demolished of their frame morphology from eight weeks. However, demolition of membranes in 8 weeks after implantation was highest in Guidor membranes and followed by S-membranes. Biocompatibilityof two kinds of biodegradable membranes including Guidor and S-mambrane were shown to be well tolerated to the surrounding tissue, and were minimal accumulation of inflammatory cell infiltration around the implanted membranes to compare with Gore-tex membrane. Regeneration of defected alveolar bone was initiated from two weeks of membrane implantation and new bone formation was gradually increased from that time. However, pattern of new bone formation on the defected areas of two kinds of biodegrable membranes was almost similar and quite competitive comparing with Gore-tex membrane. These results implicate that bioresorbable membranes should be highly useful tool for guided tissue regeneration of periodontal defects.

• Journal of Environmental Science International
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• v.18 no.6
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• pp.645-654
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• 2009

Lab-scale Electrodialysis(ED) system with different membranes combined with before or after pyroma process were carried out to remove nitrate from two pickling acid wastewater containing high concentrations of $NO_3\;^-$(${\approx}$150,000 mg/L) and F($({\approx}$ 160,000 mg/L) and some heavy metals(Fe, Ti, and Cr). The ED system before Pyroma process(Sample A) was not successful in $NO_3\;^-$ removal due to cation membrane fouling by the heavy metals, whereas, in the ED system after Pyroma process(Sample B), about 98% of nitrate was removed because of relatively low $NO_3\;^-$ concentration (about 30,000 mg/L) and no heavy metals. Mono-selective membranes(CIMS/ACS) in ED system have no selectivity for nitrate compared to divalent-selective membranes(CMX/AMX). The operation time for nitrate removal time decreased with increasing the applied voltage from 10V to 15V with no difference in the nitrate removal rate between both voltages. Nitrate adsorption of a strong-base anion exchange resin of $Cl\;^-$ type was also conducted. The Freundlich model($R^2$ > 0.996) was fitted better than Langmuir mode($R^2$ > 0.984) to the adsorption data. The maximum adsorption capacity ($Q^0$) was 492 mg/g for Sample A and 111 mg/g for Sample B due to the difference in initial nitrate concentrations between the two wastewater samples. In the regeneration of ion exchange resins, the nitrate removal rate in the pickling acid wastewater decreased as the adsorption step was repeated because certain amount of adsorbed $NO_3\;^-$ remained in the resins in spite of several desorption steps for regeneration. In conclusion, the optimum system configuration to treat pickling acid wastewater from stainless-steel industry is the multi-processes of the Pyroma-Electrodialysis-Ion exchange.

• Journal of Periodontal and Implant Science
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• v.29 no.2
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• pp.415-433
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• 1999

Implant stability is the key to long-term successful outcome for osseointegrated implants. To evaluate the initial healing response of bone around HA-coated implants without primary bone contact. 21 HA-coated thread type implants(STERI-OSS?) were placed in the femurs of 5 mongrel dogs, about 1-year old. Implants, 8 mm in length and 3.8mm(experimental 1group), 5.0mm(experimental 2group) and 6.0mm(control group) in diameter, were inserted after 3 holes of 6.0mm in diameter and 10mm in depth were prepared in the surgical sites each dog. Implants were supported by only nonresorbable membrane($Teflon^{(R)}$), in order to prevent the ingrowth of upper soft tissue into the gap between bone and implant, and to maintain each implant to be positioned in the center of the drilled hole. 9 implants with different diameters were inserted in 3 dogs for histologic observation, and 12 implants were inserted in 2 dogs for mobility test and removal torque test. Fluorescent dyes were injected for the observation of new bone formation in order of $Terramycin^{(R)}$, Arizarin $Red^{(R)}$, and $Calcein^{(R)}$ at an interval of 2 weeks. 3 dogs were sacrificed for histologic observation at 4, 8, and 12-week after placement. Light microscopy and confocal laser scanning microscopy were used to qualitatively characterize the bone around HA-coated implant. 2 dogs were sacrificed for mobility test($Periotest^{(R)}$, Simens AG, Bensheim, Germany) and removal torque test($Autograph^{(R)}$ AGS-1000D series, Japan) at 8 and 12-week after placement The results were as follows: 1. Histologic observation showed that osseointegration occurred to both control and experimental groups as time lapse, but delayed bone healing was revealed in 3.8mm group (experimental 1group), compared to contrtol group and 5.0mm group (experimental 2group). 2. The mobility test showed that the experimental groups had no distinguishable movement during experimental periods of 8 and 12-week, and there was no difference in mobility depending on the gap between bone and implant, and time lapse. 3. The removal torque forces were increased depended on the gaps decreasing between bone and implant, and time lapse. The results suggest that HA-coated implant without primary bone contact, based on guided bone regeneration could obtain its stability in all experimental groups as time lapse, but bone healing was delayed in experimental group of 3.8mm. And the results suggested that studies on correlationship between mobility test and removal torque test for implant stability would be necessary.

• Membrane and Water Treatment
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• v.12 no.1
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• pp.23-35
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• 2021

A POM-membrane was fabricated by immobilizing a keggin type polyoxometalate (POM) H5PV2Mo10O40 onto the surface of microporous flat-sheet polymeric polyvinylidene fluoride (PVFD) membrane using a chemical deposition method. The POM-membrane was characterized by FT-IR, SEM and EDX to confirm existing of the POM onto the membrane surface. The POM-membrane was used to remove an anionic textile dye (Reactive Black 5 named as an RB5) from aqueous phases with a cross-flow membrane filtration and a batch adsorption system. The dye removal efficiency of the POM-membrane using the cross-flow membrane filtration system and the batch adsorption system was about 88% and 98%, respectively. The influence factors such as contact time, adsorbent dosage, pH, and initial dye concentration were investigated to understand the adsorption mechanism of the RB5 dye onto the POM-membrane. To find the best fitting isotherm model, Langmuir, Freundlich, BET and Harkins-Jura isotherm models were used to analyze the experimental data. The isotherm analysis showed that the Langmuir isotherm model was found to the best fit for the adsorption data (R2 = 0.9982, qmax = 24.87 mg/g). Also, adsorption kinetic models showed the pseudo second order kinetic model was found the best model to fit the experimental data (R2 = 0.9989, q = 8.29 mg/g, C0 = 15 ppm). Moreover, after four times regeneration with HNO3 acid, the POM-membrane showed high regenerability without losing dye adsorption capacity.

• Journal of Plant Biotechnology
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• v.3 no.1
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• pp.39-44
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• 2001

Plastid transformation was attempted with soybean [Glycine max (L.) Merr.] leaves and photoautotrophic and embryogenic cultures by particle bombardment using the transforming vector pZVII that carries the coding sequences for both subunits of Chlamydomonas reinhardtii Rubisco and a spectinomycin resistance gene (aadA). Spectinomycin resistant calli were selected from the bombarded leaves but the transgene was not present, indicating that the resistance was due to mutations. The Chlamydomonas rbcL and rbcS genes were shown to be site-specifically integrated into the plastid genome of the embryogenic cells with a very low transformation efficiency. None of the transformed embryogenic lines survived the plant regeneration process so no whole plants were recovered. This result does indicate that it should be possible to insert genes into the plastid genome of the important crop soybean if the overall methods are improved.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.3
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• pp.456-464
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• 2008

Avian and mammalian skeletal muscles exhibit a remarkable ability to adjust to physiological stressors induced by growth, exercise, injury and disease. The process of muscle recovery following injury and myonuclear accretion during growth is attributed to a small population of satellite cells located beneath the basal lamina of the myofiber. Several metabolic factors contribute to the activation of satellite cells in response to stress mediated by illness, injury or aging. This review will describe the regenerative properties of satellite cells, the processes of satellite cell activation and highlight the potential role of satellite cells in skeletal muscle growth, tissue engineering and meat production.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.21 no.4
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• pp.70-76
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• 2022

Calcium-phosphate-based bioceramics are promising biomaterials for scaffolds because they can assist in bone regeneration. In this study, a laser sintering deposition system was developed, and 3D hydroxyapatite (HA) scaffolds were fabricated. The main process conditions of the HA scaffolds were laser power, table velocity, and laser focal distance. As the laser power increased, the line width, line height, and layer thickness also increased. Further, the line width, line height, and layer thickness decreased as the table velocity increased. As the laser focal distance increased, the line width increased, but the line height and layer thickness decreased. The fabricated green scaffolds were sintered at 1050 ℃ and 1150 ℃. The sintered scaffolds had a uniform and continuous interconnected shape, with pore sizes ranging from 850 to 950 ㎛ having 53% porosity. The compressive strength of the scaffolds decreased from 0.72 MPa (1050 ℃) to 0.53 MPa (1150 ℃). The biocompatibility of the scaffolds was investigated by analyzing the adhesion of osteoblast-like MG-63 cells cultured on the surfaces of the scaffolds. The results indicate that the scaffold sintered at 1050 ℃ had good mechanical and biological properties compared to that at 1150 ℃.

• Journal of Periodontal and Implant Science
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• v.30 no.2
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• pp.257-277
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• 2000

New techniques for regenerating the destructed periodontal tissue have been studied for many years. Current acceptable methods of promoting periodontal regeneration are basis of removal of diseased soft tissue, root treatment, guided tissue regeneration, graft materials, and biological mediators. Platelet Rich Plasma has been reported as a biological mediator which regulates activities of wound healing progress including cell proliferation, migration, and metabolism. The purpose of this study is to evaluate the effects of using the Platelet Rich Plasma as a regeneration promoting agent for furcation involvement defect. Five adult beagle dogs were used in this experiment. The dogs were anesthetized with Ketamin HCl(0.1 ml/kg, IV)and Xylazine hydrochloride($Rompun^{(R)}$, Bayer, 0.1 ml/kg, IM) and conventional periodontal prophylaxis were performed with ultrasonic scaler and hand instruments. With intrasulcular and crestal incision, mucoperiosteal flap was elevated. Following decortication with 1/2 high speed round bur, degree II furcation defect was made on mandibular third(P3), forth(P4) and fifth(P5) premolar, and stopping was inserted. After 4 weeks, stopping was removed, and bone graft was performed. Ca-P was grafted in P3(experimental group I), Combination of Ca-P and plasma rich platelet were grafted in P4(experimental group II), and P5 was remained at control group.Systemic antibiotics(gentamicin sulfate)and anlgesics(phenyl butazone) were administrated intramuscular for 2 weeks after surgery. Irrigation with 0.1% Chlorhexidine Gluconate around operate sites was performed during the whole experimental period except one day immediate after surgery. Soft diets were fed through the whole experiment period. After 4, 8 weeks, the animals were sacrificed by perfusion technique. Tissue block was excised including the tooth and prepared for light microscope with Gomori's trichrome staining. At 4 weeks after surgery, there were rapid osteogenesis phenomenon on the defected area of the Platelet Rich Plasma plus Ca-P BBP group and early trabeculation pattern was made with new osteoid tissue produced by activated osteoblast. Bone formation was almost completed to the fornix of furcation by 8 weeks after surgery. In conclusion, Platelet Rich Plasma can promote rapid osteogenesis during healing of periodontalregeneration.