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The Conductive-bridge random-access memory (CBRAM) cell is a promising candidate for a terabit-level non-volatile memory due to its remarkable advantages. We present for the first time TiN as a diffusion barrier in CBRAM cells for enhancing their reliability. CuO solid-electrolyte-based CBRAM cells implemented with a 0.1-nm TiN liner demonstrated better non-volatile memory characteristics such as ~ 106 AC write/erase endurance cycles with 100-μs AC pulse width and a long retention time of ~ 7.4-years at 85 °C. In addition, the analysis of Ag diffusion in the CBRAM cell suggests that the morphology of the Ag filaments in the electrolyte can be effectively controlled by tuning the thickness of the TiN liner. These promising results pave the way for faster commercialization of terabit-level non-volatile memories.

Abstract Recently, the demand for more data storage and fast processing has been dramatically increased for the big data markets such as artificial intelligence (AI), virtual reality (VR), autonomous car, and internet of things (IoT). Thus, a new memory such as a storage class memory (SCM) has been introduced since it can perform a reasonable latency compared to DRAM and a lower bit-cost than NAND flash memory [1]. Remind that, generally, a SCM has been fabricated with three-dimensional cross point memory cell array [2]. As a candidate memory cell for SCM, resistive-random-access-memory (ReRAM) has been proposed; i.e., called storage-type SCM. Santini, C. A. et al. demonstrated amorphous carbon oxide (a-COx) based ReRAM-cell having a reasonable memory window margin (I on/I off > 100), a fast switching speed of 20~50 ns at ~ 100-nm-diameter memory cell size. However, it showed extremely a high forming voltage (V forming) of ~ 5.0 V and a high reset voltage (V reset) of ~ – 4.0 V [3]. In particular, the a-COx based ReRAM-cell presented a different bi-stable memory characteristic for another typical ReRAM-cells; i.e., its bias directions of set and reset were opposite to a typical ReRAM, which mechanism was not evidently proved. In addition, the forming process for this ReRAM cell would be highly undesirable since it caused an extra burden for initializing memory-cells and degraded the write and erase endurance cycles [4]. Here, for the first time, we designed a forming-free Cu-doped amorphous-carbon-oxide based ReRAM cell, which did not need a forming process and we reviewed the memory operation mechanism by understanding electrical and chemical properties of the Cu-doped a-COx based ReRAM cells. A typical a-COx based ReRAM-cell needed a forming process; i.e., a forming voltage of – 2.20 V and a set voltage of – 1.05 V, as shown in Fig. 1 (a). Otherwise, a Cu-doped a-COx based ReRAM-cell could achieve a forming-free process; i.e., a forming voltage (i.e. - 0.85 V) was the same as a set voltage (i.e. – 0.85 V), as shown in Fig. 1 (b). In addition, it demonstrated a write and erase endurance cycles of ~106 by sustaining a memory margin of ~1.3×102, being able to be utilized for a commercial nonvolatile memory-cell, as shown in Fig. 1(c). To clarify the forming-free mechanism, the depth profiles of C, Cu, and O atom in the Cu-doped a-COx memory cell were observed in detail under pristine, after set, and after reset process, which were obtained from intensity line-profiles of EELS/EDS elemental mapping images at C-K edges, O-K edges, Cu-Kα, Pt-La1, and W-La1. For the pristine state, C, Cu, and O atoms are uniformly distributed in the Cu-doped a-COx layer, as shown in Fig. 1(d). In addition, after a set process, since a negative voltage was applied to the top Pt electrode, Cu atoms evidently moved and segregated toward the top Pt electrode, as shown in a of Fig. 1(e), while O atoms evidently migrated and pile up toward the bottom W electrode, as shown in b of Fig. 1(e). This result means that the conductive C-C sp2 filaments in the Cu-doped a-COx layer were produced when oxygen atoms migrated and piled up toward bottom W electrode and the conductive Cu-atom filaments were formed in the Cu-doped a-COx layer since Cu atom moved and segregated toward the top Pt electrode. Hence, both conductive C-C sp2 filaments and Cu-atom filaments were generated simultaneously in the Cu-doped a-COx layer, achieving a set process without a forming process. On the other hand, after a reset process, since a positive voltage was applied to the top Pt electrode, Cu and O atoms were redistributed inside the Cu-doped a-COx, resulting in breaking both C-C sp2 filaments and Cu-atom filaments, as shown in a and b of Fig. 1(f). In our presentation, we will demonstrate and review the mechanisms between a set process without forming process and a reset process in detail by electrical and chemical composition depth profiles depending on the applied bias condition. In particular, we will demonstrate a different ReRAM behavior of the Cu-doped a-COx based ReRAM from a typical ReRAM or CBRAM. Acknowledgement This material is based upon work supported by the Ministry of Trade, Industry & Energy(MOTIE, Korea) under Industrial Technology Innovation Program (10068055). Reference [1] Matsui, C. et al. Integration 2019, 69, 62-74. [2] Hady, F. T. et al. Proceedings of the IEEE 2017, 105, (9), 1822-1833. [3] Santini, C. A. et al. Nature Communications 2015, 6, (1), 8600. [4] Skaja, K. et al. Scientific Reports 2018, 8. Figure 1

Recently, memristive devices (e.g. CBRAM and ReRAM etc.) have been proposed as an alternative to C-MOSFET based neuromorphic device (i.e. neuron and synapse) to achieve a high neuronal density and low power consumption. Among memristive devices, the conductive bridge neuron has been a great attention due to its area efficiency, low power consumption (< 500 fJ), and good C-MOS compatibility 1-3 . However, past researches have mainly focused on stochastic nature of conductive-bridge neurons. In particular, most of the stochastic conductive-bridge neuron have used capacitors to implement membrane potential, which requires a large integration area (~1000F2). In this works, integrate property of Al2O3-based cap-less conductive-bridge neuron was demonstrated which allows a cost-efficient neuromorphic chip by using a same process technology as a memristor synapse, as shown in Fig 1 (a). Note that the Al2O3-based cap-less conductive-bridge neuron was the same as that of the Al2O3-based memristor synapse. In addition, we investigated the effect of negative-differential-resistance (NDR) characteristic on integrate property for our proposed neuron, depending on the compliance current level (i.e. a shape of metallic filaments in neuron device). The NDR slope was adjusted by varying a compliance current of a Al2O3-based cap-less conductive-bridge neuron. The current compliance (Icc) of 1 mA showed the NDR slope of ~ 0.56 decade/V, as shown in Fig. 1(b). For all spike amplitude (i.e. -0.6~-1.0 V), the resistances of neuron device abruptly increased at a certain number of spikes, depending on the spike amplitude, and then it gradually increased with the number of spikes, as shown in Fig. 1(c). In addition, the spike number being necessary for achieving ~600 Ω decreased exponentially with increasing the number of spikes, as showed integrate property depending on input spike amplitude, as shown in Fig. 1(d). Otherwise, the current compliance (Icc) of 0.1 mA, which was 10 times less than Fig 1 (b) presented the NDR slope of ~ 0.23 decade/V, which was 2 times less than Fig. 1(b), as shown in Fig. 1(e). For all spikes amplitude, the resistance of neuron devices gradually increased with the number of spikes, wherein the resistance of neuron devices increased with the spike amplitude (i.e. negative voltage pulse amplitude), as shown in Fig. 1(f). The spike number being necessary for achieving ~10 kΩ decreased exponentially with increasing the number of spikes, as shown in Fig. 1(g). Comparing Fig. 1(d) with Fig. 1(g), the variation of the spike number being necessary for achieving ~600 Ω for the NDR slope of ~-0.56 decade/V was much less that for the spike number being necessary for achieving ~10 kΩ for the NDR slope of ~-0.23 decade/V. This result indicates that, for the Al2O3-based cap-less conductive-bridge neuron, the NDR slope dominantly determines the integrate nature. In our presentation, we will discuss the mechanism why the integrate property depended on the NDR slope via understanding a shape of conductive-metallic-filaments in Al2O3 layer, which determine an integrate property of neuron devices. In particular, it will be reported that the shape of conductive-metallic-filaments strongly depended on the metal vacancy concentration in binary oxide (i.e. Al2O3) layer. Acknowledgement This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea Government (MSIT) (No. 2016M3A7B4910249). Reference "IEEE Transactions on Emerging Topics in Computational Intelligence," in IEEE Transactions on Emerging Topics in Computational Intelligence, vol. 2, no. 5, pp. C2-C2, Oct. 2018, doi: 10.1109/TETCI.2018.2867377. Jang, B. Attarimashalkoubeh, A. Prakash, H. Hwang and Y. Jeong, "Scalable Neuron Circuit Using Conductive-Bridge RAM for Pattern Reconstructions," in IEEE Transactions on Electron Devices, vol. 63, no. 6, pp. 2610-2613, June 2016, doi: 10.1109/TED.2016.2549359. Palma, M. Suri, D. Querlioz, E. Vianello and B. De Salvo, "Stochastic neuron design using conductive bridge RAM," 2013 IEEE/ACM International Symposium on Nanoscale Architectures (NANOARCH), Brooklyn, NY, 2013, pp. 95-100, doi: 10.1109/NanoArch.2013.6623051. Figure 1

Nanoscale (∼28 nm) non-volatile multi-level conductive-bridging-random-access-memory (CBRAM) cells are developed by using a CuO solid-electrolyte, providing a Vset of ∼0.96 V, a Vreset of ∼−1.5 V, a ∼1 × 102 memory margin, ∼3 × 106 write/erase endurance cycles with 100 μs AC pulse, ∼6.63 years retention time at 85 °C, ∼100 ns writing speed, and multi-level (four-level) cell operation. Their non-volatile memory cell performance characteristics are intensively determined by studying material properties such as crystallinity and poly grain size of the CuO solid-electrolyte and are found to be independent of nanoscale memory cell size. In particular, the CuO solid-electrolyte-based CBRAM cell vertically connecting with p/n/p-type oxide (CuO/IGZO/CuO) selector shows the operation of 1S(selector)1R(resistor), demonstrating a possibility of cross-bar memory-cell array for realizing terabit-integration non-volatile memory cells.

We sought to compare the efficacy of interscalene brachial plexus bolus blockade (IBPBB) and patient-controlled interscalene indwelling catheter analgesia (PCIA) for postoperative pain management within 48 hours postoperatively in patients undergoing arthroscopic rotator cuff repairs (ARCR).Patients undergoing ARCR were randomized into 3 groups by postoperative analgesia method. The IBPBB group received a mixed solution of 16 mL of 0.75% ropivacaine and 4 mL of 2% lidocaine as a bolus postoperatively. The PCIA group received a 10-mL bolus solution of 0.75% ropivacaine (4 mL) and 5% dextrose water (6 mL) just after the operation and continuous infusion of this solution. The control received only meperidine as needed, 12.5 mg, intravenously. Visual analog scale (VAS) pain scores were evaluated for the first 48 hours postoperatively.For the first 2 hours postoperatively, VAS scores in the IBPBB group were significantly lower than in the PCIA group and control group, but at 12 and 24 hours postoperatively, VAS scores of the IBPBB group were significantly higher than the PCIA group (P .05). At 48 hours postoperatively, there was no significant difference in VAS scores among the 3 groups (P = .169). The method of analgesia was the only factor affecting pain scores at 24 hours postoperatively (P .05).IBPBB provided effective immediate postoperative analgesia until 6 hours postoperatively. Especially until postoperative 2 hours, the VAS pain score was less than 1 point in the IBPBB group; however, there was significant rebound pain at 12 hours after surgery. During the first 24 hours postoperatively, PCIA reduced postoperative pain without rebound pain. Surgeons should choose methods for control of postoperative pain considering the advantages and disadvantages of each analgesic method.

We aimed to determine the quality indicators for quality prediction of frozen green pumpkin in distribution. Freshly harvested green pumpkin slices were blanched under optimal conditions (confirmed in a preliminary experiment), quick-frozen at for 24 h, and stored at 0, -5, -15, and . The correlation between each quality characteristic and the sensory preference rate was analyzed. There was a significant correlation between storage temperature-related drip rate and preference rate across all temperatures, except at. Hunter values, a and b, showed relatively high correlation coefficient values at -5, -15, and . Therefore, a change in the Hunter values should be considered when storing green pumpkin, because of their significant correlation with changes in the sensory preference and drip rates. Furthermore, they should be applied as quality indicators for the quality prediction of frozen green pumpkin in distribution.

The potential and current density distribution on the electrodes of a lithium-polymer battery were studied by using the finite element method. The effect of the configuration of the electrodes such as the aspect ratio of the electrodes and the size and placing of current collecting tabs as well as the discharge rates on the battery performance was examined to enhance the uniformity of the utilization of the active material of electrodes. The results showed that the aspect ratio of the electrodes and the size and placing of current collecting tabs have a significant effect on the potential and current density distribution on the electrodes to influence the distribution of the depth of discharge on the electrodes, thus affecting the uniform utilization of the active material of electrodes.

[Purpose] The purpose of this study was to identify the effects of Neuromuscular Electrical Stimulation (NMES) on pharyngeal transit time. [Subjects] Subjects were divided into normal old persons aged over 70 (N=18), and normal young persons aged under 30 (N=10). [Method] We measured the Pharyngeal Transit Time (PTT) to determine their swallowing characteristics. NMES was used to stimulate old group's suprahyoid and infrahyoid muscles 60 minutes a day, 5 days a week for 2 weeks using four electrodes. We used SPSS version 14.0 to analyze and compare the data between the 2 groups. [Results] After NMES, PTT of the normal old group became significantly shorter. PTT was much shorter, but was still longer than that of the normal young group. [Conclusion] The PTTs of the two groups classified by age were significantly different.

Nevus sebaceous appears at birth or within several months after birth. Secondarily to nevus sebaceous, benign or malignant tumors might occur. Basal cell carcinoma has been reported to be one of the most common malignancies. Moreover, trichoblastoma, syringocystadenoma papilliferum, apocrine cystadenoma, squamous cell carcinoma, sebaceous epithelioma, and sebaceous carcinoma might also occur [1]. In particular, there are extremely rare cases in which sebaceous carcinoma occurs secondarily to the nevus sebaceous. That is, only four Korean cases and nine from overseas countries have been reported in the literature [2]. The authors describe a case of sebaceous carcinoma that arose from the nevus sebaceous of the scalp in a 33-year-old woman. A 33-year-old woman visited us with a chief complaint of a 2×2 cm asymptomatic mass in the occiput. On past history, the patient had had a hairless yellowish plaque in the occiput since birth. Three months before the outpatient visit, the erythematous mass had begun to gradually grow in the lower 1/3 of the plaque (Fig. 1). The patient had no underlying diseases, nor did the patient have any notable findings from the family history. We performed a punch biopsy for both the yellowish plaque and the erythematous mass. This showed that the yellowish plaque was a nevus sebaceous and the erythematous mass was sebaceous epithelioma. It became evident, however, that it would be necessary to make a differential diagnosis from basal cell carcinoma originating from the sebaceous gland. Fig. 1 Preoperative view. A papillary erythematous mass of nevus sebaceous on the scalp. In the erythematous mass containing the nevus sebaceous, a wide excision was performed with a safety margin of 5 mm. A frozen section biopsy showed that there were no tumor cells on the resection margin. Following the resection, scalp defects of 2.5×5.0 cm in size remained (Fig. 2). The defects were reconstructed using a scalp rotational flap and primary closure (Fig. 3). A histopathologic examination of the resected erythematous mass was performed, and it revealed the presence of irregular lobules of varying size with a well-defined margin from the adjacent interstitial tissue in the dermis. In the center of each lobule, there were non-typical cells with a foamy cytoplasm and undifferentiated cells. This was indicative of typical sebaceous carcinoma (Fig. 4). Besides, this was also accompanied by the multiple presence of sebaceous epithelioma that comprises undifferentiated basaloid cells and mature sebocytes (Fig. 5). Fig. 2 Intraoperative view. Wide excision involving a 5-mm safety margin. Three separate rotation flaps equally positioned around the defect, raised and pivoted in the same direction. Fig. 3 Postoperative view. The reconstruction of the defect using a rotational flap and primary closure. Fig. 4 Histopathologic findings of sebaceous carcinoma. The tumor showing irregular lobules, infiltrating the surrounding tissue, composed of irregular pleomorphic basophilic cells with a foamy cytoplasm in the center of the lobule (black arrows) and undifferentiated ... Fig. 5 Histopathologic findings of sebaceous epithelioma. The tumor, showing the presence of multiple undifferentiated basaloid cells together with a potential to differentiate into sebaceous cells within an eosinophilic stroma (H&E, ×200). The current case is a relatively young patient who presented with both benign and malignant tumors, showing sebaceous differentiation, as well as the nevus sebaceous. The patient was tentatively diagnosed with Muir-Torre syndrome. A gastrofiberscopy, a colonofiberscopy, and an abdominopelvic computed tomography were therefore performed to search for gastrointestinal and urologic tumors, but no underlying malignancies were found. The patient was followed for 2 years after the operation with no recurrent episodes and no occurrence of internal malignancies. Sebaceous carcinoma is a rare malignant tumor that is differentiated from the epithelium lining of the sebaceous gland [2]. Depending on the sites of occurrence, it is classified into ocular sebaceous carcinoma and extraocular sebaceous carcinoma. Ocular sebaceous carcinoma accounts for 75% of total cases, and it also accounts for 1% to 5.5% of total cases of eyelid malignancies [3]. The remaining 25% occur at extraocular sites. However, according to the largest study of sebaceous carcinoma in a United States population [4], the proportion of ocular sebaceous carcinoma was 38.7% and the mean age of onset was 72-year-old. In the current case, the patient was 33 years old, and this is a relatively young age. To our knowledge, this is the youngest case of extraocular sebaceous carcinoma that has been reported up to the present in Korea. Muir-Torre syndrome is a rare autosomal dominant genetic trait. This is characterized by the presence of more than one of the following: a sebaceous gland tumor, i.e., sebaceous adenoma, sebaceous epithelioma, or sebaceous carcinoma. It is also accompanied by internal malignancies. Of the possible internal malignancies, the most common one is colorectal cancer. This is followed by genitourinary cancer [5]. It would therefore be desirable to consider the possibility of Muir-Torre syndrome and to perform the clinical and laboratory examinations for internal malignancies in patients who are diagnosed with sebaceous carcinoma. Also in the current case, the patient presented with benign and malignant tumors arising from the sebaceous gland at a younger age. This led to an impression of Muir-Torre syndrome followed by various clinical and laboratory examinations. However, there were no other internal malignancies. In patients with Muir-Torre syndrome, however, the sebaceous gland tumor might occur prior to or following the occurrence of internal malignancies. Otherwise, it might also be concurrently present with them. Accordingly in the current case, regular check-ups are being performed regularly to monitor the recurrence of sebaceous carcinoma and the occurrence of internal malignancies. The general treatment guidelines are that a wide excision with a safety margin of 5 to 6 mm should be performed in combination with a frozen section biopsy and a permanent section one [1,3]. In the current case, a wide excision was performed with a safety margin of 5 mm. Synchronously, a frozen section biopsy was performed for the resection margin. The ocular sebaceous carcinoma had a metastasis to such organs in 3% to 25% of total cases, based on which a poor prognosis has been well documented [2,3]. The doctor should ask about family history of skin and internal malignancies. A physical examination and laboratory examinations should be performed as well as palpation of the lymph nodes and adjacent and contiguous structures to determine the extent of disease. The authors experienced a very rare case of extraocular sebaceous carcinoma that occurred in the nevus sebaceous of the occiput, and have obtained good treatment outcomes using a wide excision with a safety margin of 5 mm and a local flap on a frozen section biopsy. Here, we report our case with a review of the literature.

Multicasting over mobile IP network becomes more important with the increasing needs of supporting multimedia services in mobile network. IETF has suggested two approaches which are remote subscription and bidirectional tunneling for supporting mobility management in multicasting over mobile IP. And the advanced schemes such as Mobile Multicast (MoM), Range-Based Mobile Multicast (RBMoM) have been proposed. But, these protocols have problems - frequent reconstruction of multicast delivery tree, packet loss during handoff, convergence problem, and so on. In this paper, we propose to use preconfiguration of multicast delivery tree when mobile host enters the foreign network. It will decrease the frequency of multicast delivery tree reconstruction, and reduce the packet loss during handoff. Also using Keep Alive messages between foreign agents makes the signaling overload of networks diminished, because the number of foreign agents which are virtually connected with current foreign agent that mobile host attaches to will remain constant.

Pancreatic pseudocysts occur following acute pancreatitis, chronic pancreatitis or secondary to pancreatic trauma. Most pancreatic pseudocysts are located in or around the pancreas, but they can be found in all the potential spaces around viscera in and outside of the abdominal cavity. The complications of pancreatic pseudocyst are infection, rupture, obstruction, fistula, or hemorrhage. Hemorrhage is a rare but frequently fatal complication of pancreatic pseudocysts. We report a case of pancreatic pseudocyst presented as bleeding of duodenum, which was misidentified for duodenal submucosal tumor bleeding. (Korean J Med 2012;82:713-717)

Background: Papillary thyroid carcinoma is among the most curable cancers, but some patients are at high risk for recurrence or even death. MHC antigens are essential molecules for the pathogenesis of carcinoma and also the physiologic immune responses against tumor. However, there is no data about the relationship between the expression of MHC antigens and the clinical prognosis of papillary thyroid carcinoma patients. Methods: We analyzed the relationship between the various prognostic factors and the MHC antigen expression by conducting a retrospective study of 215 patients, who had undergone thyroidectomy for papillary thyroid carcinoma between 1987 and 2003. Results: The expressions of MHC class II antigens were more frequent in papillary thyroid carcinoma than in the other thyroid diseases. Yet there was no statistically significant relationship between most of the clinicopathological factors and the expression of MHC class II antigens in papillary thyroid carcinoma patients. Interestingly, an HLA-DR expression was found in 8 (30.8%) of the 26 patients in the recurrence group and in 13 (76.5%) of the 17 patients in the non-recurrence group, and HLA-DP/DQ immunoreactivity was positive in 10 (38.5%) cases of the recurrence group and in 14 (82.4%) cases of the non-recurrence group. Conclusion: Papillary thyroid carcinoma showed a more frequent expression of MHC Class II antigens. However, the recurred papillary thyroid carcinoma showed a tendency to downregulate the expression of MHC class II antigens. Hence, the molecular mechanism for the expression of MHC class II antigens might have a role in the recurrence of papillary thyroid carcinoma. (J Kor Endocrinol Soc 22:26~34, 2007)

Background: Fine needle aspiration (FNA) is an accurate and safe method for the diagnosis of thyroid nodules. One of the limitations of FNA is the variable rate of unsatisfactory specimens, especially in small sized, deep seated or complex cystic nodules. To overcome this problem, ultrasound-guided FNA (US-FNA) has been widely used. In this study, the adequacy of cytologic specimens by US-FNA was compared with that of conventional palpation-guided FNA (P-FNA). Methods: The medical records of all patients who were engaged in FNA due to thyroid nodules at Chungnam National University Hospital from January 2003 to July 2004 were retrospectively examined. The US-FNA and P-FNA were performed in 114 and 185 patients, respectively. Results: Comparison of the adequacy of the two techniques in providing sufficient material for the cytologic diagnosis showed that specimens in 24 (13.0%) and 6 (5.3%) patients collected by P-FNA and US-FNA, respectively, were unsatisfactory (P =0.031). A total of 23 patients underwent thyroid surgery due to strong suspicion of malignancy at cytologic finding and/or on clinical judgement. Seventeen patients belonged to the P-FNA group and 6 patients to the US-FNA group. In the P-FNA group, a histologic diagnosis revealed two false-negative cytologic findings, but no false-negative findings were found in the US-FNA group. Conclusion: Compared with P-FNA, US-FNA may reduce the possibility of unsatisfactory cytologic specimens and the rate of false-negative diagnosis, and may improve the diagnostic accuracy in investigating thyroid nodules (J Kor Soc Endocrinol 20:154～159, 2005).

Background: Thyroid cancers account for about 1% of all human malignancies, with papillary thyroid carcinomas being the most common istotype. Several investigators have recently identified the most common BRAF mutation, the T1796A transversion mutation, in 29~69% of papillary thyroid cancers. The BRAF mutation has been demonstrated as a novel prognostic biomarker for the prediction of poor clinicopathological outcomes, such as increased incidence of extrathyroid invasion and distant metastasis of the tumor. In this study, we investigated the prevalence of the BRAF mutation of thyroid tissues obtained by a thyroidectomy, and its correlation with the clinicopathological outcomes. Methods: We studied 36 thyroid tissues obtained from 24 women and 12 men by thyroidectomies, including 30 papillary carcinomas, 3 follicular carcinomas, 1 medullary carcinoma and 2 nodular hyperplasia. The mutation was sought in all specimens using DNA sequencing. Results: We studied the BRAF exon 15 T1796A in these 36 thyroid tissue s. The mean age at surgery was 46.6, ranging from 18 to 72 years, with a median tumor size of 2.79, ranging from 1.5 to 4.5 cm. At the time of diagnosis, 27 of the 34 patients presented with some kind of extrathyroidal invasion of the tumor, and 16 had lymph node metastases. 16, 2 and 16 patients were in stages I, II and III, respectively. There was no distant metastasis. A missense mutation was found at T1796A in exon 15 in 21 of the 30 papillary carcinomas (70%). The other thyroid diseases, including the 3 follicular carcinomas, 1 medullary carcinoma and 2 nodular hyperplasia show no exon 15 T1759A transversion mutation. No statistically significant association was found between the BRAF mutations and clinicopathological characteristics of papillary carcinomas. Conclusion: The BRAF mutation is a important genetic alteration, with a high prevalence in papillary thyroid carcinomas. However, there was no significant association between the BRAF mutation and any of the clinicopathological factors. Further, large scale studies will be needed to evaluate the correlation between the BRAF mutation and the clinicopathological factors (J Kor Soc Endocrinol 20:224～229, 2005).