• 제목/요약/키워드: soft magnetic

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Coercivity of Near Single Domain Size Nd2Fe14B-type Particles

  • Kwon, H.W.;Yu, J.H.
    • Journal of Magnetics
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    • 제17권3호
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    • pp.185-189
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    • 2012
  • The coercivity of near single domain size $Nd_2Fe_{14}B$-type particles prepared by ball milling of HDDR-treated $Nd_{12.5}Fe_{80.6}B_{6.4}Ga_{0.3}Nb_{0.2}$ alloy was investigated. The feasibility of a surface nitrogenation for improving the coercivity stability of the fine $Nd_2Fe_{14}B$-type particles was also studied. The near single domain size $Nd_2Fe_{14}B$-type particles had a high coercivity of over 9 kOe. However, the coercivity radically deteriorated as the temperature increased in air (< 2 kOe at $200^{\circ}C$). This coercivity reduction was attributed to the soft magnetic phases, ${\alpha}$-Fe and $Fe_3B$, which formed on the surface of the fine particle due to oxidation. Surface nitrogenation of the fine particles significantly improved the stability of their coercivity. The improvement in coercivity stability was attributed to the formation of a thin nitrogenated layer on the surface of the fine $Nd_2Fe_{14}B$-type particles, which enhanced the anisotropy field and gave improved resistance to oxidation (dissociation).

A giant trichoblastic carcinoma

  • Lee, Joon Seok;Kwon, Joon Hyun;Jung, Gyu Sik;Lee, Jeong Woo;Yang, Jung Dug;Chung, Ho Yun;Cho, Byung Chae;Choi, Kang Young
    • 대한두개안면성형외과학회지
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    • 제19권4호
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    • pp.275-278
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    • 2018
  • Trichoblastic carcinoma usually occurs as a malignant transformation of the trichoblastoma, but is very rare. A 25-year-old man was admitted with trichoblastoma in the nuchal area with frequent recurrences since birth. The preoperative neck magnetic resonance image revealed lobulated soft tissue lesions involving superficial fascia and infiltrating into both proximal trapezius muscles. In our department, wide excision and reconstruction with a free anterolateral thigh flap were performed. Histological examination revealed skin adnexal carcinoma, originating from the hair follicles, consistent with trichoblastic carcinoma. There was no palpable mass 5 years postoperatively, and there was no recurrence on follow-up positron emission tomography-computed tomography. Trichoblastic carcinomas are rare and difficult to diagnose, but histopathological findings include atypical basaloid keratinocytes with crowded, hyperchromatic nuclei, and increased mitotic activity. The presence of hypercellular stroma is a criterion for distinguishing trichoblastic carcinoma from basal cell carcinoma. A rare giant trichoblastic carcinoma was reported, which was the biggest one in the literature.

Differential Diagnosis and Treatment of Septic Arthritis in the Temporomandibular Joint: A Case Report and Literature Review

  • Kim, Bola;Choi, Hyo-Won;Kim, Jae-Young;Park, Kwang-Ho;Huh, Jong-Ki
    • Journal of Oral Medicine and Pain
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    • 제44권3호
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    • pp.127-132
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    • 2019
  • Septic arthritis of the temporomandibular joint (TMJ) is an uncommon disease caused by microbial pathogens through hematogenous infection, local spread, or iatrogenic infection. As the symptoms have an insidious onset, the early stage of septic arthritis is often confused with other diseases. A 49-year-old man was referred for increasing preauricular pain, swelling, and restricted mouth opening. He had been initially diagnosed as having a conventional temporomandibular joint disorder and trigeminal neuralgia and had been treated for the same. Imaging studies including panoramic view, lateral tomography, computed tomography with contrast enhancement, and magnetic resonance imaging were performed. Erosive bone change with displacement of the involved condyle, diffuse swelling of adjacent soft tissue, and fluid collection in the joint space were noted. Needle aspiration of the joint space and bacterial culture confirmed the diagnosis of septic arthritis of the TMJ and he was treated with antibiotic therapy and surgical drainage. Clinicians should always consider the diagnosis of septic arthritis of the TMJ in patients with preauricular pain or swelling.

Atypical proliferative nodule in congenital melanocytic nevus with dural invasion: a case report

  • Jung, Jae Hoon;Jang, Kee-Taek;Kim, Ara;Lim, So Young
    • 대한두개안면성형외과학회지
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    • 제20권2호
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    • pp.139-143
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    • 2019
  • Here we report a case of a focal atypical proliferative nodule (PN) arising from a congenital melanocytic nevus (CMN). Diagnosis was challenging because it had both benign and malignant clinical features. Unusual histopathology, immunohistochemistry, and intraoperative findings of this atypical PN are discussed. A 5-year-old girl was admitted for a congenital $5{\times}5cm$ sized scalp mass. This hemangioma-like soft mass showed biphasic characteristics such as a slow, gradual, and benign increase in size but worrisome dural invasion with cranial bone defect. We removed the scalp mass with clear resection margins. Interoperatively, we found that the cranial bone defect had already filled. Histopathologic examination showed CMN with focal atypical PN. The nodule showed sharp demarcation and cellular pleomorphism. However, in immunohistochemical study, Ki-67 proliferation index and expression levels of protein S-100 and Melan-A were very low. These were unusual findings of atypical PNs. Despite her worrisome preoperative radiologic features, she showed an indolent clinical course compatible with previously reported biologic behavior. The patient underwent follow-up inspection with magnetic resonance imaging every 6 months for up to 3 years. The nodule appeared to be stationary at the last visit.

A Case Of Cavernous Sinus Syndrome and Mutifocal Cerebral Infarction Related To Mucormycosis Of Sphenoid Sinus

  • Jeon, Seok Won;Kim, Chang Hoi;Kim, Joo Yeon;Kwon, Jae Hwan
    • 고신대학교 의과대학 학술지
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    • 제33권3호
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    • pp.454-462
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    • 2018
  • A 54-year-old man, suffering from severe headache and ophthalmoplegia after undergoing endoscopic sinus surgery was referred to a tertiary hospital. Computed tomography (CT) revealed soft tissue density lesions in the left sphenoid sinus. The internal carotid artery was shown to be occluded in brain magnetic resonance imaging (MRI) scans without any other cerebral lesion. Endoscopic view of left nasal cavity shows whitish hyphae in the ethmoid and the sphenoid sinuses. We diagnosed him with cavernous sinus syndrome caused by mucormycosis and conducted endoscopic sinus surgery to remove remaining lesions and decompress orbit and optic nerves. After the revision surgery the patient's headache and ophthalmoplegia were improved. However, multifocal cerebral infarctions were newly discovered in a postoperative CT scan. We experienced a case of mucormycosis of sphenoid sinus resulting in occlusion of internal carotid artery and multifocal cerebral infarction, and report it with a brief review of these disease entities.

Importance of 3-dimensional imaging in the early diagnosis of chondroblastic osteosarcoma

  • Laura Althea Cuschieri;Rebecca Schembri-Higgans;Nicholas Bezzina;Alexandra Betts;Arthur Rodriguez Gonzalez Cortes
    • Imaging Science in Dentistry
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    • 제53권3호
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    • pp.247-256
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    • 2023
  • The aim of this report is to present a case of chondroblastic osteosarcoma located in the right maxillary premolar region of a 17-year-old female patient. The initial clinical presentation and 2-dimensional (2D) radiographic methods proved inadequate for a definitive diagnosis. However, a cone-beam computed tomography scan revealed a hyperdense, heterogeneous lesion in the right maxillary premolar region, exhibiting a characteristic "sun-ray" appearance. To assess soft tissue involvement, a medical computed tomography scan was subsequently conducted. A positron emission tomography scan detected no metastasis or indications of secondary tumors. T1- and T2-weighted magnetic resonance imaging showed signal heterogeneity within the lesion, including areas of low signal intensity at the periphery. Histological examination conducted after an incisional biopsy confirmed the diagnosis of highgrade chondroblastic osteosarcoma. The patient was then referred to an oncology department for chemotherapy before surgery. In conclusion, these findings suggest that early diagnosis using 3-dimensional imaging can detect chondroblastic osteosarcoma in its early stages, such as before metastasis occurs, thereby improving the patient's prognosis.

반복적인 골프 스윙으로 인한 노쪽손목굽힘근 힘줄의 파열 (Flexor Carpi Radialis Tendon Rupture due to Repetitive Golf Swing)

  • 이상철;고성훈;장진혁;안재기
    • Clinical Pain
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    • 제18권2호
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    • pp.107-110
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    • 2019
  • Flexor carpi radialis (FCR) muscle is located in the forearm anteriorly that runs through a synovial fibro-osseous tunnel in the forearm. We described a case of FCR tendon rupture due to repetitive overuse injury. A 55-year-old man, right-hand dominant, presented with right forearm pain and swelling which started 3 days ago while playing amateur golf. Focal tenderness and bruising over volo-ulnar region of the right forearm were examined. Plain radiographs showed soft tissue edema around lesion area and no detectable fracture. Ultrasonography showed multiple hypoechoic lesions suspected as hematoma of the flexor muscle group. After done magnetic resonance imaging, he was diagnosed with rupture of FCR tendon at proximal origin and strain of flexor digitorum superficialis and palmaris longus muscle. He received compressive dressing and restriction of wrist range of motion for three weeks. Two months later, remaining traces of lesions were observed at the follow-up ultrasonography and the pain disappeared.

A Case Report of Madelung's Disease

  • Bo Hyun Lee;Young Mann Lee;Seong Oh Park;Lan Sook Chang;Youn Hawn Kim
    • Archives of Plastic Surgery
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    • 제50권5호
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    • pp.463-467
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    • 2023
  • Madelung's disease (MD) is a rare disease characterized by diffuse, nonencapsulated, multiple fat masses in different areas of the body. In this case report, we present a case of MD in Asia and its management. A 66-year-old man with a history of hypertension presented with massive growth of soft tissue around the neck, breasts, upper back, and lower abdomen. Preoperative magnetic resonance imaging revealed remarkably hypertrophic fat tissue around the neck and anterior chest was wall, which consistent with the diagnosis of MD. Multiple linear incisions were made on the neck and 763, 186, 635 g of posterior, right, and left fat tissues were excised, respectively. A single wide, transverse incision was done to excise 1,072 g of fat from the upper back. Masses of both breasts were excised, preserving the inferior pedicle, weighing 1,086 (right) and 1,164 g (left). The recovery was optimal and the patient was discharged without complications. In this case, we excised the adipose masses as much as possible and improved contour and symmetry. However, the fat infiltrations in the patient were diffusely distributed, making total fat excision difficult. This rare case report may help in managing patients with MD.

Management and rehabilitation of moderate-to-severe diabetic foot infection: a narrative review

  • Chi Young An;Seung Lim Baek;Dong-Il Chun
    • Journal of Yeungnam Medical Science
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    • 제40권4호
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    • pp.343-351
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    • 2023
  • Diabetic foot is one of the most devastating consequences of diabetes, resulting in amputation and possibly death. Therefore, early detection and vigorous treatment of infections in patients with diabetic foot are critical. This review seeks to provide guidelines for the therapy and rehabilitation of patients with moderate-to-severe diabetic foot. If a diabetic foot infection is suspected, bacterial cultures should be initially obtained. Numerous imaging studies can be used to identify diabetic foot, and recent research has shown that white blood cell single-photon emission computed tomography/computed tomography has comparable diagnostic specificity and sensitivity to magnetic resonance imaging. Surgery is performed when a diabetic foot ulcer is deep and is accompanied by bone and soft tissue infections. Patients should be taught preoperative rehabilitation before undergoing stressful surgery. During surgical procedures, it is critical to remove all necrotic tissue and drain the inflammatory area. It is critical to treat wounds with suitable dressings after surgery. Wet dressings promote the formation of granulation tissues and new blood vessels. Walking should begin as soon as the patient's general condition allows it, regardless of the wound status or prior walking capacity. Adequate treatment of comorbidities, including hypertension and dyslipidemia, and smoking cessation are necessary. Additionally, broad-spectrum antibiotics are required to treat diabetic foot infections.

유방의 겨드랑꼬리에 발생한 악성 종양: 영상 소견을 포함한 증례 보고 (Carcinoma of the Axillary Tail of Spence: A Case Report with Imaging Findings)

  • 박소연;이지영;박지연
    • 대한영상의학회지
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    • 제83권5호
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    • pp.1189-1194
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    • 2022
  • 유방의 겨드랑꼬리에 발생한 악성 종양은 유방의 특정 해부학적 위치에서 발생하는 유방암의 한 종류이며 발생률은 0.3% 정도로 드문 질환이다. 이는 겨드랑이에서 발생하는 연부조직 종양, 액와부 부유방에서 발생한 유방암, 유방암의 림프절 전이 또는 다른 원발암의 림프절 전이 등과 감별이 필요하다. 저자들은 겨드랑이 종물을 주소로 내원한 47세 환자에서 유방촬영술, 초음파, 전산화단층촬영, 자기공명영상을 통해 겨드랑꼬리 유방암을 진단한 증례를 경험하여 보고하고자 한다.