• Journal of Korean Society of Water and Wastewater
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• v.25 no.1
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• pp.41-49
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• 2011

The diffuser which is conventionally adapted to MBR, has problem that decreasing the cleaning effect of membrane module by inflexible air supply due to the occlusion of sludge from diffuser hole. To solve this problem, diffuser structure of submerged module should be improved to discharge sludge which is flow into the diffuser for prevent occlusion in the diffuser. In this study, the structure of the diffuser was reformed to open lower part for preclusion the blocking. And the outlet diameter of the diffuser was drawn through the condition for the depth of water and air rate, to prevent air-leak condition of improved diffuser. Moreover, application is evaluated by comparing test with occlusion effect of the conventional and improved diffuser. From the results, air-water boundary changes are steady with changes of water depth and it shows linear relation about air rate. By using this linear numerical formula, the height of diffuser's outlet can be decided. Also, it displays that it can prevent the occlusion effect during the comparing test. Hereafter, if this diffuser is applied to practical MBR process, the occlusion problem of diffuser will be disappeared.

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.4
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• pp.993-999
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• 2005

This research was peformed to investigate protective effect of Sophora Subprostrata fractions against focal ischemic brain damage after middle cerebral artery(MCA) occlusion using intraluminal suture. Rats were divided into six groups: MCA-occluded group(Control): each administered groups with Sophora Subprostrata total phase(Total), Sophora Subprostrata Aqueous phase (Aqueous), Sophora Subprostrata BuOH phase(BuOH), and Sophora Subprostrata Alkaloid phase(Alkaloid) after MCA-occlusion; sham-operated group(Sham). The right MCA was occluded by A poly-L-lysine coated 4-0 nylon suture thread through the internal carotid artery permanently. Sophora Subprostrata and fractions were administered orally(Smg/ml) for 7 days after MCA-occlusion. The Drain tissue was stained with $2\%$ triphenyl tetrazolium chloride on ischemic brain tissue(2mm section). The results showed that 1) Sophora Subprostrata total phase reduced infarct size and total infarct volume compared to the control group at 24 hours after MCA-occlusion, 2) Sophora Subprostrata Aqueous phase reduced infarct size and total infarct volume compared to the control group at 24 hours after MCA-occlusion, 3) Sophora Subprostrata Alkaloid phase reduced infarct size compared to the control group at 24 hours after MCA-occlusion, but 4) at 7 days after MCA-occlusion, Sophora Subprostrata did not show effective recovery compared with control group. Sophora Subprostrata has protective effects against brain damage at the early stage of focal cerebral ischemia. Sophora Subprostrata total and Aqueous phase produced more pronounced protective effect against focal ischemic brain damage.

• The Journal of the Korean dental association
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• v.53 no.6
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• pp.418-426
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• 2015

The appropriate occlusion is one of the most important factors for the long-term success of implant and its restorations. The purpose of this review is to investigate and define occlusal considerations to reduce failure of implant prostheses. The physiological movement of implants is markedly lower than that of natural teeth and they also lack in occlusal sensitivity. Proper occlusal pattern may be assigned to compensate for the biological disadvantages and occlusal contacts must be formed where the cantilever effect is minimized. Moreover, the long-term success of implants after osseointegration can be assured by reducing early occlusal loading to avoid implant overloading and selecting appropriate occlusion material. Occlusal overload was brought by the number and location of occlusal contacts, which are under the clinician's control. The concept of implant occlusion is based on the concepts derived from traditional prosthetics. Moreover, there are few evidence on the concept or design of implant occlusion. Several occlusal design was recommended for implant prosthesis. Mutually protected occlusion, group function occlusion and bilateral balance occlusion was recommended for the specific types of implant restorations. This article reviews proper design of occlusion for implant restoration and offers occlusion strategy clinically.

• The Journal of Korean Medicine
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• v.22 no.1
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• pp.10-21
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• 2001

Objective : This study was performed to investigate the protective effect of Stephania tetrandra(ST) against ischemic brain damage after a middle cerebral artery(MCA) occlusion. The effect was evaluated using histological tests, neurobehavioral tests, and biochemical tests. Methods : Rats(Sprague-Dawley) were divided into four groups : sham operated group, MCA occluded group, post MCA occlusion Stephania tetrandra administrated (7.6mg/l00g) group, and normal group. The MCA was occluded by intraluminal method. Stephania tetrandra was administrated orally twice at 1 and 4 hours after MCA occlusion. The neurobehavioral test was performed at 3, 6, 9 and 24 hours after MCA occlusion by posture reflex test and swimming behavioral test. All groups were sacrificed then. The brain tissues were stained with 2% triphenyl tetrazolium chloride(TTC) or 1 % cresyl violet solution, to examine infarct size, volume and cell number. Tumor necrosis $factor-{\alpha}$ level was measured from sera using Enzyme-Linked Immunoabsorbent Assay(ELISA). The mRNA expression level of inflammatory cytokines and related receptor type I and II, $IL-1{\beta}$, IL-6, and IL-10 6hours after MCA occlusion were also studied by reverse transcriptase polymerase chain reaction(RTPCR). Results : The results showed that : Stephania tetrandra (1) reduced infarct size and total infarct volume by 52.2% compared to the control group; (2) attenuated significantly in neuronal death, which was shown by a decrease in cell number(P<0.01) and size(P<0.01) in the boundary area of the infarction; (3) significantly reduced serum $TNF-{\alpha}$ level, and increased the mRNA level of IL-10 in the cortex region(P<0.01). However, there was no significant effect on motor deficit in swimming behavioral test. Conclusions : In conclusion, Stephania tetrandra has protective effects against ischemic brain damage at the early stage of ischemia.

• Journal of Institute of Control, Robotics and Systems
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• v.17 no.6
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• pp.596-601
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• 2011

Autonomous navigating algorithms for mobile robots have been proved to be a difficult task. Based on the excellent homing performance shown by many insects, bio-inspired navigation algorithms for robotic experiments have been widely researched and applied to the design of navigational strategies for mobile robots. In this paper, among them, we analyze two simple landmark navigation methods their strengths and limits. We investigate the effect of the occlusion problem mainly, which is an important yet tough problem in many landmark navigation algorithms. In the point of view of the error of homing vector and the performance of the homing paths in the environment with artificial occlusions, we investigate the effect of occlusion problem in both methods in order to further study on solutions.

• The Journal of the Korean dental association
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• v.58 no.8
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• pp.496-504
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• 2020

The osseointegrated implants react biomechanically in a different pattern to occlusal force, due to lack of the periodontal ligament unlike the natural teeth. The implants show markedly less movement and limited tactile sensitivity compared with the natural teeth. The implant occlusion concept aims to avoid overloading on the implants and to direct occlusal loads along the longitudinal axis of the implants, in order to compensate for the different biomechanics of the implants. Although many guidelines and theories on implant occlusion have been proposed, few have provided strong supportive evidence. Moreover, the outcome of treatment often quite successful in spite of different concepts of occlusion and there is an increasing tendency to doubt about the strict theoretical implant-specific occlusion concept. The purpose of this article is to review the previous reports about the concept of implant occlusion and discuss clinical occlusal considerations in implant rehabilitations.

• The Journal of Advanced Prosthodontics
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• v.9 no.1
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• pp.45-51
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• 2017

PURPOSE. This study aims to investigate the effects of four different lateral occlusion schemes and different excursions on peri-implant strains of a maxillary canine implant. MATERIALS AND METHODS. Four metal crowns with different occlusion schemes were attached to an implant in the maxillary canine region of a resin model. The included schemes were canine-guided (CG) occlusion, group function (GF) occlusion, long centric (LC) occlusion, and implant-protected (IP) occlusion. Each crown was loaded in three sites that correspond to maximal intercuspation (MI), 1 mm excursion, and 2 mm excursion. A load of 140 N was applied on each site and was repeated 10 times. The peri-implant strain was recorded by a rosette strain gauge that was attached on the resin model buccal to the implant. For each loading condition, the maximum shear strain value was calculated. RESULTS. The different schemes and excursive positions had impact on the peri-implant strains. At MI and 1 mm positions, the GF had the least strains, followed by IP, CG, and LC. At 2 mm, the least strains were associated with GF, followed by CG, LC, and IP. However, regardless of the occlusion scheme, as the excursion increases, a linear increase of peri-implant strains was detected. CONCLUSION. The peri-implant strain is susceptible to occlusal factors. The eccentric location appears to be more influential on peri-implant strains than the occlusion scheme. Therefore, adopting an occlusion scheme that can reduce the occurrence of occlusal contacts laterally may be beneficial in reducing peri-implant strains.

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.3
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• pp.760-764
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• 2005

This research was performed to investigate protective effect of Sophora Subprostrata fractions against focal ischemic brain damage after middle cerebral artery(MCA) occlusion. Rats were divided into six groups: MCA-occluded group(Control); each administered groups with Sophora Subprostrata total phase(Total), Sophora Subprostrata Aqueous phase (Aqueous), Sophora Subprostrata BuOH phase(BuOH), and Sophora Subprostrata Alkaloid phase(Alkaloid) after MCA-occlusion; sham-operated group(Sham). The right MCA was occluded by A poly-L-lysine coated 4-0 nylon suture thread through the internal carotid artery permanently. Sophora Subprostrata and fractions were administered orally(5mg/ml) for 7 days after MCA-occlusion. The behavior of ischemic rats were examined at 24 hours, 3, 5 and 7 days after MCA-occlusion from the views of 4 different aspects: posture & balance tests(4 subtests), reflex tests(6 subtests), muscle-tone tests(3 subtests), and foot-fault test. The results showed that 1) in muscle tone test, Sophora Subprostrata total phase only increased reduced muscle tone function from 3 to 7 days, 2) in reflex test, Sophora Subprostrata total and Aqueous phase increased fast recovery from 24 hours and 3 days, 3) in posture & balance test, Sophora Subprostrata total and Aqueous phase increased fast recovery from 24 hours, and Sophora Subprostrata BuOH and Alkaloid phase increased posture & balance function from 3 days, but 4) in motor function test, Sophora Subprostrata did not show effective recovery compared with control group. In conclusion, Sophora Subprostrata has protective effects against brain damage at the early stage of focal cerebral ischemia. Sophora Subprostrata total and Aqueous phase produced more pronounced protective effect against focal ischemic brain damage.

• Journal of Veterinary Clinics
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• v.23 no.1
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• pp.50-54
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• 2006

To evaluate the effect of punctal occlusion on tear preservation after third eyelid resection, 10 eyes were operated in dogs and observed changes in tear preservation using Schirmer tear test (STT). Punctal occlusion was performed on five healthy dogs with no clinical sings of ocular irritation and no history of dry eye syndrome. The STT was performed for 10 days before surgery, and on the day 0, 1, 3, 5, 7, 9, 11, 13, 17, 21, 25, and 30 after third eyelid resection. The mean STT was $17.4{\pm}0.15$ mm/min($mean{\pm}SEM$) for 10 days before surgery. And, it was $11.5{\pm}0.55$mm/min for 30 days after surgery in puntal occlusion(PO) group. The mean STT was $17.3{\pm}0.32$ mm/min for 10 days before surgery. And, it was more decreased to $6.5{\pm}0.60$ mm/min for 30 days after surgery in control group. The paired t-test was performed. Mean STT after the third eyelid resection was higher in PO group than that of control throughout experimental period (p<0.05). In summary, the effect of thermal punctal occlusion significantly increased on the tear preservation by $28.86{\pm}7.96%$. These results suggest that application of thermal punctal occulsion in dry eye syndrome will promote tear preservation.

• The Journal of Advanced Prosthodontics
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• v.13 no.4
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• pp.216-225
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• 2021

PURPOSE. The aim of this study is to evaluate the effects of canine guidance occlusion and group function occlusion on the degree of stress to the bone, implants, abutments, and crowns using finite element analysis (FEA). MATERIALS AND METHODS. This study included the implant-prosthesis system of a three-unit bridge made of monolithic zirconia and hybrid abutments. Three-dimensional (3D) models of a bone-level implant system and a titanium base abutment were created using the original implant components. Two titanium implants, measuring 4 × 11 mm each, were selected. The loads were applied in two oblique directions of 15° and 30° under two occlusal movement conditions. In the canine guidance condition, loads (100 N) were applied to the canine crown only. In the group function condition, loads were applied to all three teeth. In this loading, a force of 100 N was applied to the canine, and 200-N forces were applied to each premolar. The stress distribution among all the components of the implant-bridge system was assessed using ANSYS SpaceClaim 2020 R2 software and finite element analysis. RESULTS. Maximum stress was found in the group function occlusion. The maximum stress increased with an increase in the angle of occlusal force. CONCLUSION. The canine guidance occlusion with monolithic zirconia crown materials is promising for implant-supported prostheses in the canine and premolar areas.