• International Journal of Industrial Entomology and Biomaterials
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• 제41권2호
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• pp.36-44
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• 2020

Mulberry root bark is one of potential plant sources for antioxidant materials which can be used for the relief of oxidative stress. To explore the effects of solvent type and temperature on the structural characteristics and antioxidant activity of the root bark extracts, we prepared various extracts of mulberry root bark (Morus alba L.) using 0 - 100 % ethanol (EtOH) at RT - 100℃. EtOH concentration and temperature critically affected the extraction yields, the content of bioactive components, and antioxidant activity of the extracts. Use of high content of EtOH solvent and low temperature resulted in the low extraction yield. Meanwhile, it was revealed that the extract prepared using absolute EtOH at room temperature contained polyphenols and flavonoids with the highest contents among other extracts. Interestingly, the temperature differently affected the polyphenol and flavonoid contents according to the solvent types. In the case of 30% EtOH solvent, polyphenol and flavonoid contents increased with an increase in temperature, whereas in the case of 70 and 100 % EtOH, these contents decreased. Using the radical scavenging assay, it was confirmed that the 100% EtOH extracts had higher antioxidant activity compared to distilled water (DW) extracts regardless of temperature. Also, heating might extract more antioxidant components from the root bark. Especially, the extract prepared using 30% EtOH solvent at 100℃ showed the highest antioxidant activity. Taken together, these experimental results imply that the extraction parameters should be designed carefully considering the productivity, the extracted bioactive components, and antioxidant activity.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2018년도 추계학술대회
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• pp.123-123
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• 2018

Premenstrual syndrome (PMS) is a common disorder affecting the emotional and physical health of women during certain periods of the menstrual cycle. Many researchers who have previously studied PMS have believed that PMS is associated with changes in sex hormones and serotonin levels at the beginning of the menstrual cycle. However, recent studies suggest that progesterone/estrogen imbalance and elevation of prolactin-induced by dopamine low-secretion play a crucial role in increasing PMS symptoms. Because of this, we have focused on mitigating PMS symptoms through the mechanism of prolactin secretion inhibition by dopamine receptor activation. The inhibition of prolactin secretion by 61-kinds of medicinal herb extracts was investigated in GH3 pituitary cells. Among them, Inula heleniun L. root extract (IHE) showed excellent prolactin secretion inhibitory effect. IHEs were prepared using 30, 50, and 70% ethanol. And the yield, cytotoxicity, dopamine receptor activity and inhibition of prolactin secretion of each extract were measured. Through a series of experiments, we found that prolactin secretion was significantly reduced (P<0.01) by the components present in IHE and that dopamine receptor regulation was possible (P<0.05). Considering yield and safety, we suggest the use of 30% ethanol IHE in the development of PMS symptom relief products.

• The Korean Journal of Pain
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• 제18권1호
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• pp.69-73
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• 2005

This report describes a case of spinal nerve root compression due to an acute inflammatory granuloma after lumbar surgery. A 39 year-old man with a history of increasing back pain with a 3-week duration was diagnosed with a herniated intervertebral disc (HIVD). The diagnosis of a HIVD was confirmed by magnetic resonance imaging (MRI) with indications for surgery. A discectomy and a partial laminectomy was performed and the symptoms were alleviated immediately after surgery for a five-day period. However, a slowly progressing pain was subsequently noted along a different dermatome. There was no pain relief despite the patient being given pharmacological treatments, combined with an epidural steroid injection. The follow up MRI images showed severe compression of the nerve roots by a epidural lesion. Another procedure was performed 17 days after the initial operation. The lesion responsible for the compression of the nerve roots was found to be an acute inflammatory granuloma. The pain was relieved after the second procedure and there were no other symptoms or neurological problems. This case is remarkable in that a granuloma formed relatively quickly and grew to such a size that it was able to severely compress the surrounding nerve roots.

• Clinics in Orthopedic Surgery
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• 제10권4호
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• pp.508-512
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• 2018

Foraminal decompression using a minimally invasive technique to preserve facet joint stability and function without fusion reportedly improves the radicular symptoms in approximately 80% of patients and is considered one of the good surgical treatment choices for lumbar foraminal or extraforaminal stenosis. However, proper decompression was not possible because of the inability to access the foramen at the L5-S1 level due to prominence of the iliac crest. To overcome this challenge, endoscopy-based minimally invasive spine surgery has recently gained attention. Here, we report the technical skills required in unilateral extraforaminal biportal endoscopic spinal surgery using a $30^{\circ}$ arthroscope to enable foraminal decompression at the L5-S1 level. Two 0.8-cm portals were created 2 cm lateral from the lateral border of the pedicles at the L5-S1 level. After sufficient working space was made, half of the superior articular process (SAP) in the hypertrophied facet joint was removed using a high-speed burr and a 5-mm wide osteotome, whereas the remaining inside part of the SAP was removed using a Kerrison punch and pituitary punch. The foraminal ligamentum flavum should be removed to inspect the conditions of the L5 exiting root and disc. Removing of the extruded disc could decompress the L5 root. The extraforaminal approach using a $30^{\circ}$ arthroscope is considered a minimally invasive alternative technique for decompressing foraminal stenosis at the L5-S1 level that preserves facet stability and provides symptomatic relief.

• 대한정형외과학회지
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• 제55권3호
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• pp.229-236
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• 2020

목적: 초음파 유도하 요추 4번 신경근 차단술을 시행함에 있어 시술 전 자기공명영상(magnetic resonance imaging, MRI) 계측의 유용성을 알아보고자 하였다. 대상 및 방법: 이 연구는 후향적 연구로 2016년 3월부터 2017년 12월까지 본원 외래에 방문한 환자 중 요추 4번 신경근의 병변이 확인되며 선정 기준에 합당한 71명의 환자를 대상으로 하였다. 2016년 3월부터 2017년 2월까지 MRI 계측 없이 신경근 차단술을 시행한 31명의 환자를 A군, 2017년 3월부터 2017년 12월까지 시술 전 MRI 계측을 통해 신경근 차단술을 시행한 40명의 환자를 B군으로 분류하였다. A군은 MRI 계측 없이 pararadicular 접근법을 통하여 주사를 시행하였고 B군은 시술 전 MRI로 측정한 계측치를 바탕으로 하여 초음파 유도하 주사를 시행하였다. 시술 전, 시술 3시간 후, 2주 후, 6주 후, 12주 후에 수치평가척도(numeric rating scale, NRS) 점수를 이용하여 통증 호전 정도를 판정하였다. 결과: 시술 3시간 후 양호 이상의 결과를 보인 경우는 A군에서 51.6%, B군에서 67.5%였으며 시술 2주 후 양호 이상의 결과를 보인 경우는 A군에서 48.4%, B군에서 70.0%였다. 시술 6주 후 양호 이상의 결과를 보인 경우는 A군에서 58.1%, B군에서 62.5%, 시술 12주 후 양호 이상의 결과를 보인 경우는 A군에서 67.7%, B군에서 62.5%였다. 시술 3시간 후, 2주차에 유의하게 B군이 A군보다 증상 호전에 좋은 결과를 보였다(p<0.05). 만족스런 통증 완화를 위해 2주차에서 6주차 사이에 A군의 경우 2.8회, B군의 경우 1.7회의 반복적인 시술이 시행되었다(p<0.05). 결론: 시술 전 MRI를 통한 계측을 먼저 시행하고 이를 참고하여 초음파 유도하 요추 4번 선택적 신경근 차단술을 시행하는 것은 환자의 시술의 성공률을 높여 시술 후 2주 이내의 초기 통증을 완화하는데 도움이 될 것으로 생각된다.

• Journal of Korean Neurosurgical Society
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• 제52권3호
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• pp.257-260
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• 2012

Spinal extradural arachnoid cysts usually cause symptoms related to spinal cord or nerve root compression. Here, we report an atypical presentation of a spinal extradural arachnoid cyst combined with congenital hemivertebra which was presented as a retroperitoneal mass that exerted mass effects to the abdominal organs. On image studies, the communication between the cystic pedicle and the spinal arachnoid space was indistinct. Based on our experience and the literature of the pathogenesis, we planned anterior approach for removal of the arachnoid cyst in order to focus on mass removal rather than ligation of the fistulous channel. In our estimation this was feasible considering radiologic findings and also essential for the symptom relief. The cyst was totally removed with the clogged 'thecal sac-side' end of the cystic pedicle. The patient was free of abdominal discomfort by one month after the surgery.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 1999년도 제30회 추계학술대회
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• pp.25-34
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• 1999

In this study, the sliding wear in spur gears, using Archard's wear model, is analyzed. Formulas of tooth sliding wear depth along the line of action are derived. The tooth profile is modified Id make a smooth transmission of the normal loads and the cylinder profile for reducing the pressure spike is suggested. The sliding wear rate is calculated with these profiling results. We expect these modification methods to contribute to the reduction of sliding wear in the root and the tip of tooth and tooth edge.

• Structural Engineering and Mechanics
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• 제70권1호
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• pp.43-54
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• 2019

Due to various numerical problems, crack analysis of reinforced concrete members using the finite element method is confronting with substantial difficulties, rendering the prediction of crack patterns and crack widths a formidable task. The root cause is that the conventional analysis methods are not capable of tracking the crack sequence and accounting for the stress relief and re-distribution during cracking. To address this deficiency, the crack queuing algorithm has been proposed. Basically, at each load increment, iterations are carried out and within each iteration step, only the most critical concrete element is allowed to crack and the stress re-distribution is captured in subsequent iteration by re-formulating the cracked concrete element and re-analysing the whole concrete structure. To demonstrate the effectiveness of the crack queuing algorithm, crack analysis of concrete members tested in the literature is performed with and without the crack queuing algorithm incorporated.

• Journal of Korean Neurosurgical Society
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• 제51권5호
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• pp.276-280
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• 2012

Objective : Gamma knife radiosurgery (GKRS) is the least invasive surgical option for patients with trigeminal neuralgia (TN). However, the indications and long term outcomes of GKRS are still controversial. Additionally, a series with uniform long-term follow-up data for all patients has been lacking. In the present study, the authors analyzed long-term outcomes in a series of patients with TN who underwent a single GKRS treatment followed by a minimum follow-up of 60 months. Methods : From 1994 to 2009, 40 consecutive patients with typical, intractable TN received GKRS. Among these, 22 patients were followed for >60 months. The mean maximum radiation dose was 77.1 Gy (65.2-83.6 Gy), and the 4 mm collimator was used to target the radiation to the root entry zone. Results : The mean age was 61.5 years (25-84 years). The mean follow-up period was 92.2 months (60-144 months). According to the pain intensity scale in the last follow-up, 6 cases were grades I-II (pain-free with or without medication; 27.3%) and 7 cases were grade IV-V (<50% pain relief with medication or no pain relief; 31.8%). There was 1 case (facial dysesthesia) with post-operative complications (4.54%). Conclusion : The long-term results of GKRS for TN are not as satisfactory as those of microvascular decompression and other conventional modalities, but GKRS is a safe, effective and minimally invasive technique which might be considered a first-line therapy for a limited group of patients for whom a more invasive kind of treatment is unsuitable.

• The Korean Journal of Pain
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• 제14권2호
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• pp.234-238
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• 2001

Percutaneous laser discectomy has potential advantages over conservative therapy and classical open surgery as a minimally invasive procedure, although clinical experiences are limited. We experienced a patient treated with herniated lumbar discs using Nd：YAG laser. A 55-year-old woman complained of severe back pain with sciatica on L4/5 and L5/S1 dermatome for several months. The MRI finding showed bulging discs at L4/5 and L5/S1. Epidural, transsacral and root block treatments were attempted without effect. Under fluoroscopic guidance, a 14 G biopsy needle was inserted into the L4/5 and L5/S1 disc spaces to the margin of the nucleus pulposus. Laser irradiation for vaporization of tissue was performed at 20 W/second to 1200 J. A laser fiber ($600{\mu}m$) was advanced 1 cm from the tip of the needle. At the end of the procedure, the patient began to feel relief of pain (VAS changed from 9 to 4) and was discharged the same day after staying 2 hours in the recovery room. Antibiotics were administered for prevention of discitis. She had no complaints of pain until the 1-month follow up visit. Percutaneous laser discetomy technique has the disadvantages of expensive equipment, high temperature and amount of vaporing disc tissue is empirical. However, this technique, as one of the therapeutic modalities for disc herniation, provides faster relief from acute attack than conservative management techniques in carefully selected patients with sciatica due to disc prolapse.