• Journal of Korean Neurosurgical Society
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• v.66 no.1
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• pp.90-94
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• 2023

Objective : Cubital tunnel syndrome, the most common ulnar nerve entrapment neuropathy, is usually managed by simple decompression or anterior transposition. One of the concerns in transposition is damage to the nerve branches around the elbow. In this study, the location of ulnar nerve branches to the flexor carpi ulnaris (FCU) was assessed during operations for cubital tunnel syndrome to provide information to reduce operation-related complications. Methods : A personal series (HJY) of cases operated for cubital tunnel syndrome was reviewed. Cases managed by transposition and location of branches to the FCU were selected for analysis. The function of the branches was confirmed by intraoperative nerve stimulation and the location of the branches was assessed by the distance from the center of medial epicondyle. Results : There was a total of 61 cases of cubital tunnel syndrome, among which 31 were treated by transposition. Twenty-one cases with information on the location of branches were analyzed. The average number of ulnar nerve branches around the elbow was 1.8 (0 to 3), only one case showed no branches. Most of the cases had one branch to the medial head, and one other to the lateral head of the FCU. There were two cases having branches without FCU responses (one branch in one case, three branches in another). The location of the branches to the medial head was 16.3±8.6 mm distal to the medial epicondyle (16 branches; range, 0 to 35 mm), to the lateral head was 19.5±9.5 mm distal to the medial epicondyle (19 branches; range, -5 to 30 mm). Branches without FCU responses were found from 20 mm proximal to the medial condyle to 15 mm distal to the medial epicondyle (five branches). Most of the branches to the medial head were 15 to 20 mm (50% of cases), and most to the lateral head were 15 to 25 mm (58% of cases). There were no cases of discernable weakness of the FCU after operation. Conclusion : In most cases of cubital tunnel syndrome, there are ulnar nerve branches around the elbow. Although there might be some cases with branches without FCU responses, most branches are to the FCU, and are to be saved. The operator should be watchful for branches about 15 to 25 mm distal to the medial epicondyle, where most branches come out.

• Journal of Veterinary Clinics
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• v.40 no.2
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• pp.93-103
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• 2023

The tendon is a dense connective tissue that connects muscle to bone and plays an essential role in joint motion. The injured tendon heals slowly owing to its low cellularity and vascularity. This study aimed to evaluate and compare the effects of regenerative injection therapy (RIT), 20 % dextrose prolotherapy (DP), and platelet-rich plasma (PRP) injections that can promote tendon healing. Twenty-one New Zealand white rabbits were divided into the control, DP, and PRP treatment groups. The superficial digital flexor tendon (SDFT) of the right hindlimb of each rabbit was used. A round defect of 2 mm was induced. Approximately 0.2 mL of 20% dextrose and autologous PRP were injected into the proximal and distal ends of the SDFT mass. Radiographic and ultrasonographic examination and cross-sectional area (CSA) calculations were performed pre-operatively and at 2, 4, and 8 weeks. The SDFT of both limbs was transected for biomechanical and histomorphometric evaluations. The SDFT of the left limb was transected for intact control. Semi-quantitative analysis was performed to evaluate the histomorphometric properties. Additional analysis was performed using H&E, Masson's trichrome, and immunohistochemical staining. The biomechanical evaluation showed that the treatment groups had higher tensile strength compared to the defect control group, while the PRP group had higher tensile strength than the DP group. On histological examination, the treatment groups appeared to be relatively closer to the remodeling phase of the healing process than the defect control group; the characteristics of the PRP group were closer to the remodeling phase than those of the DP group. The ultrasonographic examination showed different tendencies. Increased values in the CSA were observed during the early period in the treatment groups. This study suggests that PRP and DP can promote the healing of tendon injury, and these effects were superior with PRP than that with DP.

• Journal of Korean Neurosurgical Society
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• v.65 no.1
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• pp.84-95
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• 2022

Objective : To investigate the clinical efficacy and safety of the controlled distraction-compression technique using an expandable titanium cage (ETC) in posttraumatic kyphosis (PTK). Methods : We retrospectively studied and collected data on 20 patients with PTK. From January 2014 to December 2017, the controlled distraction-compression technique using ETC was consecutively performed in 20 patients with PTK of the thoracolumbar zone (range, 36-82 years). Among them, nine were males and 11 were females and the mean age was 61.5 years. The patients were followed regularly at 1, 3, 6, and 12 months, and the last follow-up was more than 2 years after surgery. Results : The mean follow-up period was 27.3±7.3 months (range, 14-48). The average operation time was 286.8±33.1 minutes (range, 225-365). The preoperative regional kyphotic angle (RKA) ranged from 35.6° to 70.6° with an average of 47.5°±8.1°. The immediate postoperative mean RKA was 5.9°±3.8° (86.2% correction rate, p=0.000), and at the last follow-up more than 2 years later, the mean RKA was 9.2°±4.9° (80.2% correction rate, p=0.000). The preoperative mean thoracolumbar kyphosis was 49.1°±9.2° and was corrected to an average of 8.8°±5.3° immediately after surgery (p=0.000). At the last follow-up, a correction of 11.9°±6.3° was obtained (p=0.000). The preoperative mean back visual analog scale (VAS) score was 7.9±0.8 and at the last follow-up, the VAS score was improved to a mean of 2.3±1.0 with a 70.9% correction rate (p=0.000). The preoperative mean Oswestry disability index (ODI) score was 32.3±6.9 (64.6%) and the last follow-up ODI score was improved to a mean of 6.85±2.9 (3.7%) with a 78.8% correction rate (p=0.000). The overall complication was 15%, with two of distal junctional fractures and one of proximal junctional kyphosis and screw loosening. However, there were no complications directly related to the operation. Conclusion : Posterior vertebral column resection through the controlled distraction-compression technique using ETC showed safe and good results in terms of complications, and clinical and radiologic outcomes in PTK. However, to further evaluate the efficacy of this surgical procedure, more patients need long-term follow-up and there is a need to apply it to other diseases.

• Nuclear Engineering and Technology
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• v.55 no.4
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• pp.1460-1467
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• 2023

A robust approach was conducted to determining the absolute oral bioavailable (f_ab) fractions of ²³⁸U and ²³²Th in rats exposed to contaminated soil along with their hematotoxicity and nephrotoxicity. The soil sample is the International Atomic Energy Agency-312 (IAEA-312) certified reference material, whereas blood, bones, and kidneys of in vivo female Sprague-Dawley (SD) rats estimate ²³⁸U- and ²³²Th-f_ab fractions post-exposure. We predict the bioavailable concentration (C_ab) and f_ab values of ²³⁸U and ²³²Th after acute soil ingestion. The blood ²³⁸U (0.750%) and ²³²Th (0.028%) reach their maximum f_ab values after 48 h. The ²³⁸U (f_ab: 0.169-0.652%) accumulates mostly in the kidney, whereas the ²³²Th (f_ab: 0.004-0.021%) accumulates primarily in the bone. Additionally, ²³⁸U is more bioavailable than ²³²Th. Post 48 h acute ingestion demonstrates noticeable histopathological and hematological alterations, implying that intake of ²³⁸U in co-contaminated soil can lead to erythrocytes and proximal tubules damage, whereas, ²³²Th intake can harm erythrocytes. Our study provides new directions for future research into the health implications of acute oral exposures to ²³⁸U and ²³²Th in co-contaminated soils. The findings offer significant insight into the utilization of in vivo SD rat testing to estimate ²³⁸U and ²³²Th bioavailability and toxicity in exposure assessment.

• Journal of the Korean Orthopaedic Association
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• v.54 no.4
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• pp.353-360
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• 2019

Purpose: In the treatment of Dupuytren's contracture, the aim of optical treatment is to lower the recurrence rate and reduce complications. This paper reports the results of subtotal fasciectomy in Dupuytren's contracture, extending the excision of palmar fascial structures from the diseased to normal appearing adjacent fascial structure. Materials and Methods: From 2007 to 2017, 45 patients with Dupuytren's contracture treated by subtotal fasciectomy were reviewed retrospectively. The mean follow-up period was 45.9 months. Ninety-two digits were involved (index: 2, middle: 10, ring: 44, little: 36). The predisposing factors and affected joint were reviewed and the preoperative and postoperative contracture was measured. For clinical results, quick disabilities of the arm, shoulder, and hand (quick DASH) were used. Complications, including wound or skin problems, nerve injuries, hematoma, and complex regional pain syndrome, were assessed. Results: Preoperative flexion contracture was 43.2° in the proximal interphalangeal joint and 32.9° in the metacarpophalangeal joint. In nine cases, patients had residual contracture of 9.7° (range, 5°-20°) on average and if the total number of cases were included, the mean residual contracture was 2.3° on average. The quick DASH score at the 12 months follow-up was 12.4. The overall complication rate was 26.6%. Conclusion: Subtotal fasciectomy can be a good surgical treatment option for Dupuytren's contracture with a low recurrence and low complication rate compared to other open procedures.

• Proceedings of the Korea Information Processing Society Conference
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• 2020.11a
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• pp.858-861
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• 2020

로봇이 사람과 같이 다양하고 복잡한 사물 조작을 하기 위해서 휴먼형 로봇손의 사물 파지 작업이 필수적이다. 자유도 (Degree of Freedom, DoF)가 높은 휴먼형(anthropomorphic) 로봇손을 학습시키기 위하여 사람 데모(human demonstration)가 결합된 강화학습 최적화 방법이 제안되었다. 본 연구에서는 강화학습 최적화 방법에 사람 데모가 결합된 Demonstration Augmented Natural Policy Gradient(DA-NPG)와 NPG 의 성능 비교를 통하여 행동 복제의 효율성을 확인하고, DA-NPG, DA-Trust Region Policy Optimization (DA-TRPO), DA-Proximal Policy Optimization (DA-PPO)의 최적화 방법의 성능 평가를 위하여 6 종의 물체에 대한 휴먼형 로봇손의 사물 조작 작업을 수행한다. 그 결과, DA-NPG 와 NPG를 비교한 결과를 통해 휴먼형 로봇손의 사물 조작 강화학습에 행동 복제가 효율적임을 증명하였다. 또한, DA-NPG 는 DA-TRPO 와 유사한 성능을 보이면서 모든 물체에 대한 사물 파지에 성공하여 가장 안정적이었다. 반면, DA-TRPO 와 DA-PPO 는 사물 조작에 실패한 물체가 존재하여 불안정한 성능을 보였다. 본 연구에서 제안하는 방법은 향후 실제 휴먼형 로봇에 적용하여 휴먼형 로봇 손의 사물조작 지능 개발에 유용할 것으로 전망된다.

• 한국체육학회지인문사회과학편
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• v.54 no.1
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• pp.535-544
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• 2015

This study was performed to determine the effect of low-intensity resistance training with blood flow restriction (BFR) on muscle volume and strength in elderly women. Sixteen elderly women (70.9±4.6 years) were divided into low (30% 1RM) and high (75% 1RM) intense resistance training groups. Tourniquet cuff (Zimmer, Germany) for BFR was applied only to the right leg during the training period. All subjects performed unilateral leg press, leg extension and leg curl (3 sets×12 repetitions) for 10 weeks (2d/wk). Blood pressure was increased from 110 to 240 mmHg during the training period at the most proximal region of exercised leg. Muscle volume and cross-sectional area (CSA) were measured by MRI and body composition was monitored by dual-energy X-ray absorptiometry (DEXA) and isokinetic muscular strength were analyzed in both legs. The quadriceps CSA (15.2%, p<.001) and muscle volume (13.8%, p<.001) were increased in high-intense trained leg with BFR and the increased rate was highest among groups. The quadriceps CSA (9.8%, p<.001) and muscle volume (6.9%, p<.001) were increased in low-intensity training group with BFR and their increased rates were higher than control groups. The strength by exercise training was significantly improved in all groups and tended to be higher in BFR groups. These results demonstrate low-intensity resistance training with blood flow restriction could be an effective way to improve muscle volume and strength in elderly women.

• Journal of Integrative Natural Science
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• v.16 no.1
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• pp.13-31
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• 2023

The sesarmid crab Muradium tetragonum, inhabiting the mangrove, are considered as a key consumer of litter and thereby play an important role in the detritus food chain and energy flow in the mangrove ecosystem. The present investigation was carried out with objectives to enlighten the reproductive system of Muradium tetragonum through histological and histochemical studies. Histological organization of the testis of M. tetragonum revealed that each testis has a lobular structure consisting of several testicular lobules arranged around the collecting duct. Histology of the deferens of M. tetragonum revealed it to be composed of three-layer of tissues along the entire length:the outer connective tissue, the middle muscular and the inner epithelial layer. Based on the histological architecture these three regions are recognized as proximal vas deferens (PVD), middle vas deferens (MVD) and distal vas deferens (DVD). Histological characteristics of the ovary of M. tetragonum during different phases of ovarian development were studied. Based on the colour changes of the ovary and diameter of the oocytes five stages of ovarian development can be pronounced. Histochemical analysis of the male reproductive tissues of M. tetragonum signifies the secretion of a different biomolecule by specifying their origin in the reproductive tissue and their possible transformation into spermatophores. In the female reproductive tissues, histochemical evaluation envisaged the secretory products during different stages of ovarian development The secretory substances of the spermatheca expound on the significance of its secretion in dehiscing the spermatophore wall and in nourishing as well as protecting the spermatozoa.

• The Korean Journal of Zoology
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• v.15 no.3
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• pp.111-131
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• 1972

Fine structures of retina of an ommatidium in dragonfly, having eyes of closed rhabdom type, were studied under light and electron microscopes. The ommatidia consisted of eight retinular cells distributed in a circular pattern and the retinular layer in turn can be divided into three sublayers according to the number of cells in the retina. Each retinular cell has different starting points in the retina and the length of retinular cells is varied greatly; the length of one distal retinular cell shows one half of that of others. In the middle layer, three proximal retinular cells interconnect the adjacent two rhabdoms which are triangular in the appearence of the cross section which in turn consisted of tubular, parallel and lamellated microvilli. The rhabdom is formed by three rhabdomeres, each of which is separated by $120^{\circ}$ between them, but they can be distinguished into two parts according to electron density. Around the outer part of microvilli composing rhabdom, electron density was much less than the inner part of the structure. The microvilli of the inner part appear to be connected to the cytoplasm of retinular cells. Rough endoplsmic reticulum with enlarged cisternae runs through the vacuoles in the outer part of distal retinular cells. Abundant mitochondria concentrated in the vicinity of rhabdom are found at the central part of the retinular cells, while in the area of immediate vicinity of the rhabdom, prominent vacuoles are observed. Above the rhabdom of an ommtidium stands a crystalline cone which is consisted of four cone cells arranged radially along the axis. The crystalline cone is surrounded by cells containing pigment granules. The outermost photoreceptor element of an ommatidium is corneal lens.

• Korean Journal of Social Welfare Studies
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• v.41 no.1
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• pp.175-201
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• 2010

The purpose of this study was to examine the mechanism through which youth school-based mentoring program impacts mentees' psychological and school-related outcomes such as self-esteem, self-efficacy, and attitudes toward school. The hypothetical model was assumed that mentors could improve their mentees' developmental outcomes through positive relationships with mentors as good role models and enhancement of help-seeking orientation. To investigate the mediating effect of process-related outcomes, structural equation modeling was used. The 97 adolescents were recruited through referral and random selection from middle schools in Seoul. The result showed that the effects of program participation were mediated by proximal changes in connectedness to role models and development of help-seeking orientation that, in turn, led to facilitate more positive attitudes toward school and academic activity, and improve psychological outcomes. Practice and policy implications as well as further research topics were discussed to aid the search for highly effective mentoring programs.