• 제목/요약/키워드: implantation damage

검색결과 86건 처리시간 0.025초

레이져 어닐링을 이용한 낮은 면저항의 극히 얕은 접합 형성 (Ultra shallow function Formation of Low Sheet Resistance Using by Laser Annealing)

  • 정은식;배지철;이용재
    • 한국정보통신학회:학술대회논문집
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    • 한국해양정보통신학회 2001년도 춘계종합학술대회
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    • pp.349-352
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    • 2001
  • 본 논문은 기가 SRAM급 이상의 초고집적을- 위한 0.1$\mu\textrm{m}$의 설계치수를 갖는 MOSFET의 게이트 영역에서 활성 부분의 면저항을 감소시키기 위해 n영역으로 비소를 이온 주입하였다. 어닐링은 급속 열처리 공정 방법과 엑시머 레이져 어닐링 방법을 이용하였으며, 극히 얕은 접합의 형성이 가능하였다. 얕은 접합 형성 깊이는 10~20nm이며, 비소의 주입량은 2$\times$$10^{14}$ $\textrm{cm}^2$이고, 레이져는 엑시머이며 소스는 KrF로 파장은 248mm로 어닐링 하였다. 극히 얕은 P/N$^{+}$ 접합 깊이가 15nm이며, 이때 1k$\Omega$/$\square$의 낮은 면저항 특성을 갖는 결과가 나타났다.

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이온주입에 의한 소오스/드레인 접합부 결함을 제거한 다결정 실리콘 박막 트렌지스터 (The Elimination of ion Implantation Damage at the Source/Drain Junction of Poly-Si TFTs)

  • 강수혁;정상훈;이민철;박기찬;한민구
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2002년도 하계학술대회 논문집 C
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    • pp.1410-1412
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    • 2002
  • TFT의 게이트 전극을 형성하기 전에 소오스/드레인 이온 주입과 ELA를 수행함으로써 이온 주입에 의해 발생하는 결정 결함을 줄이는 새로운 poly-Si TFT를 제안한다. 한번의 ELA 공정을 통해서 채널 실리콘 박막의 결정화와 소오스/드레인의 불순물 활성화를 동시에 이루어 접합부의 결함을 치유하였고, 이온 주입에 의해서 비정질화된 소오스/드레인 실리콘과 채널 비정질 실리콘의 용융조건 차이를 이용하여 소오스/드레인 접합부에 실리콘 그레인의 수평성장을 유도하였다. 제안된 소자는 기존의 소자(이동도 : 86 $cm^2/V{\cdot}S$, ON/OFF 전류비 $6.1{\times}10^6$)에 비해 우수한 특성(이동도 : 171 $cm^2/V{\cdot}S$, ON/OFF 전류비 $4.1{\times}10^7$)을 나타내었다. LDD나 off-set 구조 없이도 소오스/드레인 접합부의 결함이 완전히 제거되어 누설전류가 감소하였고 소오스/드레인 접합부 결함이 있던 자리에 1 ${\mu}m$ 이상의 수평성장 그레인이 위치함으로써 ON 전류도 증가하여 ON/OFF 전류비가 크게 개선되었다.

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Endoplasmic reticulum stress in periimplantation embryos

  • Michalak, Marek;Gye, Myung Chan
    • Clinical and Experimental Reproductive Medicine
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    • 제42권1호
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    • pp.1-7
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    • 2015
  • Stress coping mechanisms are critical to minimize or overcome damage caused by ever changing environmental conditions. They are designed to promote cell survival. The unfolded protein response (UPR) pathway is mobilized in response to the accumulation of unfolded proteins, ultimately in order to regain endoplasmic reticulum (ER) homeostasis. Various elements of coping responses to ER stress including Perk, Ask1, Bip, Chop, Gadd34, Ire1, Atf4, Atf6, and Xbp1 have been identified and were found to be inducible in oocytes and preimplantation embryos, suggesting that, as a normal part of the cellular adaptive mechanism, these coping responses, including the UPR, play a pivotal role in the development of preimplantation embryos. As such, the UPR-associated molecules and pathways may become useful markers for the potential diagnosis of stress conditions for preimplantation embryos. After implantation, ER stress-induced coping responses become physiologically important for a normal decidual response, placentation, and early organogenesis. Attenuation of ER stress coping responses by tauroursodeoxycholate and salubrinal was effective for prevention of cell death of cultured embryos. Further elucidation of new and relevant ER stress coping responses in periimplantation embryos might contribute to a comprehensive understanding of the regulation of normal development of embryonic development and potentiation of embryonic development in vitro.

Median Nerve Stimulation in a Patient with Complex Regional Pain Syndrome Type II

  • Jeon, Ik-Chan;Kim, Min-Su;Kim, Seong-Ho
    • Journal of Korean Neurosurgical Society
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    • 제46권3호
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    • pp.273-276
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    • 2009
  • A 54-year-old man experienced injury to the second finger of his left hand due to damage from a paintball gun shot 8 years prior, and the metacarpo-phalangeal joint was amputated. He gradually developed mechanical allodynia and burning pain, and there were trophic changes of the thenar muscle and he reported coldness on his left hand and forearm. A neuroma was found on the left second common digital nerve and was removed, but his symptoms continued despite various conservative treatments including a morphine infusion pump on his left arm. We therefore attempted median nerve stimulation to treat the chronic pain. The procedure was performed in two stages. The first procedure involved exposure of the median nerve on the mid-humerus level and placing of the electrode. The trial stimulation lasted for 7 days and the patient's symptoms improved. The second procedure involved implantation of a pulse generator on the left subclavian area. The mechanical allodynia and pain relief score, based on the visual analogue scale, decreased from 9 before surgery to 4 after surgery. The patient's activity improved markedly, but trophic changes and vasomotor symptom recovered only moderately. In conclusion, median nerve stimulation can improve chronic pain from complex regional pain syndrome type II.

솔잎혹파리 항공방제용 저독성 농약선발연구 (Studies on Selection of Less Toxic Insecticides for the Aerial Control of Pine Needle Gall Midge (Thecodiplosis) japonensis Uchida et Inouye))

  • 이형래;변병호
    • 한국응용곤충학회지
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    • 제33권3호
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    • pp.201-206
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    • 1994
  • 솔잎혹파리 방제는 포스팜 50% 액제를 수간 주입에 의해 수행되고 있으나 약제처리가 농작업이 많은 시기임으로 노동력의 부족으로 인한 실제 방제에 문제점이 있어 항고기를 이용한 약제방제가 필요하여 저독성 약제인 곤충발육저해제 중 Buprofezin 40% 액상 수화제가 선발되었고 10배, 30배, 50배로 희석하여 ULV로 살포한 결과 각각 72.4%, 57.6%, 8.4%의 방제효과를 얻어 항공방제용 약제 선발가능성을 시사하고 있다.

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Embryo sexing methods in bovine and its application in animal breed

  • Bora, Shelema Kelbessa
    • 한국동물생명공학회지
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    • 제37권2호
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    • pp.80-86
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    • 2022
  • The ability to determine the sex of bovine embryos before the transfer is advantageous in livestock management, especially in dairy production, where female calves are preferred in milk industry. The milk production of female and male cattle benefits both the dairy and beef industries. Pre-implantation sexing of embryos also helps with embryo transfer success. There are two approaches for sexing bovine embryos in farm animals: invasive and non-invasive. A non-invasive method of embryo sexing retains the embryo's autonomy and, as a result, is less likely to impair the embryo's ability to move and implant successfully. There are lists of non-invasive embryo sexing such as; Detection of H-Y antigens, X-linked enzymes, and sexing based on embryo cleavage and development. Since it protects the embryo's autonomy, the non-invasive procedure is considered to be the safest. Invasive methods affect an embryo's integrity and are likely to damage the embryo's chances of successful transformation. There are different types of invasive methods such as polymerase chain reaction, detection of male chromatin Y chromosome-specific DNA probes, Loop-mediated isothermal amplification (LAMP), cytological karyotyping, and immunofluorescence (FISH). The PCR approach is highly sensitive, precise, and effective as compared to invasive methods of farm animal embryonic sexing. Invasive procedures, such as cytological karyotyping, have high accuracy but are impractical in the field due to embryonic effectiveness concerns. This technology can be applicable especially in the dairy and beef industry by producing female and male animals respectively. Enhancing selection accuracy and decreasing the multiple ovulation embryo transfer costs.

Distribution of the lingual foramina in mandibular cortical bone in Koreans

  • Kim, Dae Hyun;Kim, Moon Yong;Kim, Chul-Hwan
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • 제39권6호
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    • pp.263-268
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    • 2013
  • Objectives: The interforminal region, between the mandibular foramen, is known as a relatively safe area that is free of anatomic structures, such as inferior alveolar nerve, submandibular fossa, and lingual side of the mandible is occasionally neglected for its low clinical importance. Even in the case of a severely constricted alveolus, perforation of the lingual cortical bone had been intended. However, anterior extension of the inferior alveolar canal, important anatomic structure, such as concavity of lingual bone, lingual foramina, and lingual canal, has recently been reported through various studies, and untypical bleeding by perforation of the lingual plate on implantation has also been reported. Therefore, in this study, we performed radiographic and statistical analysis on distribution and appearance frequencies of the lingual foramina that causes perforation of the mandibular lingual cortical bone to prevent complications, such as untypical bleeding, during surgical procedure. Materials and Methods: We measured the horizontal length from a midline of the mandible to the lingual foramina, as well as the horizontal length from the alveolar crest to the lingual foramina and from the lingual foramina to the mandibular border by multi-detector computed tomography of 187 patients, who visited Dankook University Dental Hospital for various reasons from January 1, 2008 to August 31, 2012. Results: From a total of 187 human mandibles, 110 (58.8%) mandibles had lingual foramina; 39 (20.9%) had bilateral lingual foramen; 34 (18.2%) had the only left lingual foramen; and 37 (19.8%) had the only right lingual foramen. Conclusion: When there is consistent bleeding during a surgical procedure, clinicians must consider damages on the branches of the sublingual artery, which penetrate the lingual foramina. Also, when there is a lingual foramina larger than 1 mm in diameter on a pre-implantation computed tomography, clinicians must beware of vessel damage. In order to prevent these complications and progress with a safe surgical procedure, a thorough radiographic examination before the surgery is indispensable. Further, clinicians should retract lingual flap definitely to confirm the shape of the lingual bone and existence of the lingual foramina.

Optically Controlled Silicon MESFET Modeling Considering Diffusion Process

  • Chattopadhyay, S.N.;Motoyama, N.;Rudra, A.;Sharma, A.;Sriram, S.;Overton, C.B.;Pandey, P.
    • JSTS:Journal of Semiconductor Technology and Science
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    • 제7권3호
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    • pp.196-208
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    • 2007
  • An analytical model is proposed for an optically controlled Metal Semiconductor Field Effect Transistor (MESFET), known as Optical Field Effect Transistor (OPFET) considering the diffusion fabrication process. The electrical parameters such as threshold voltage, drain-source current, gate capacitances and switching response have been determined for the dark and various illuminated conditions. The Photovoltaic effect due to photogenerated carriers under illumination is shown to modulate the channel cross-section, which in turn significantly changes the threshold voltage, drainsource current, the gate capacitances and the device switching speed. The threshold voltage $V_T$ is reduced under optical illumination condition, which leads the device to change the device property from enhancement mode to depletion mode depending on photon impurity flux density. The resulting I-V characteristics show that the drain-source current IDS for different gate-source voltage $V_{gs}$ is significantly increased with optical illumination for photon flux densities of ${\Phi}=10^{15}\;and\;10^{17}/cm^2s$ compared to the dark condition. Further more, the drain-source current as a function of drain-source voltage $V_{DS}$ is evaluated to find the I-V characteristics for various pinch-off voltages $V_P$ for optimization of impurity flux density $Q_{Diff}$ by diffusion process. The resulting I-V characteristics also show that the diffusion process introduces less process-induced damage compared to ion implantation, which suffers from current reduction due to a large number of defects introduced by the ion implantation process. Further the results show significant increase in gate-source capacitance $C_{gs}$ and gate-drain capacitance $C_{gd}$ for optical illuminations, where the photo-induced voltage has a significant role on gate capacitances. The switching time ${\tau}$ of the OPFET device is computed for dark and illumination conditions. The switching time ${\tau}$ is greatly reduced by optical illumination and is also a function of device active layer thickness and corresponding impurity flux density $Q_{Diff}$. Thus it is shown that the diffusion process shows great potential for improvement of optoelectronic devices in quantum efficiency and other performance areas.

Oxidative Stress Induced Damage to Paternal Genome and Impact of Meditation and Yoga - Can it Reduce Incidence of Childhood Cancer?

  • Dada, Rima;Kumar, Shiv Basant;Chawla, Bhavna;Bisht, Shilpa;Khan, Saima
    • Asian Pacific Journal of Cancer Prevention
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    • 제17권9호
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    • pp.4517-4525
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    • 2016
  • Background: Sperm DNA damage is underlying aetiology of poor implantation and pregnancy rates but also affects health of offspring and may also result in denovo mutations in germ line and post fertilization. This may result in complex diseases, polygenic disorders and childhood cancers. Childhood cancer like retinoblastoma (RB) is more prevalent in developing countries and the incidence of RB has increased more than three fold in India in the last decade. Recent studies have documented increased incidence of cancers in children born to fathers who consume alcohol in excess and tobacco or who were conceived by assisted conception. The aetiology of childhood cancer and increased disease burden in these children is lin ked to oxidative stress (OS) and oxidative DNA damage( ODD) in sperm of their fathers. Though several antioxidants are in use to combat oxidative stress, the effect of majority of these formulations on DNA is not known. Yoga and meditation cause significant decline in OS and ODD and aid in regulating OS levels such that reactive oxygen speues meditated signal transduction, gene expression and several other physiological functions are not disrupted. Thus, this study aimed to analyze sperm ODD as a possible etiological factor in childhood cancer and role of simple life style interventions like yoga and meditation in significantly decreasing seminal oxidative stress and oxidative DNA damage and thereby decreasing incidence of childhood cancers. Materials and Methods: A total of 131 fathers of children with RB (non-familial sporadic heritable) and 50 controls (fathers of healthy children) were recruited at a tertiary center in India. Sperm parameters as per WHO 2010 guidelines and reactive oxygen species (ROS), DNA fragmentation index (DFI), 8-hydroxy-2'-deoxy guanosine (8-OHdG) and telomere length were estimated at day 0, and after 3 and 6 months of intervention. We also examined the compliance with yoga and meditation practice and smoking status at each follow-up. Results: The seminal mean ROS levels (p<0.05), sperm DFI (p<0.001), 8-OHdG (p<0.01) levels were significantly higher in fathers of children with RB, as compared to controls and the relative mean telomere length in the sperm was shorter. Levels of ROS were significantly reduced in tobacco users (p<0.05) as well as in alcoholics (p<0.05) after intervention. DFI reduced significantly (p<0.05) after 6 months of yoga and meditation practice in all groups. The levels of oxidative DNA damage marker 8-OHdG were reduced significantly after 3 months (p<0.05) and 6 months (p<0.05) of practice. Conclusions: Our results suggest that OS and ODD DNA may contribute to the development of childhood cancer. This may be due to accumulation of oxidized mutagenic base 8OHdG, and elevated MDA levels which results in MDA dimers which are also mutagenic, aberrant methylation pattern, altered gene expression which affect cell proliferation and survival through activation of transcription factors. Increased mt DNA mutations and aberrant repair of mt and nuclear DNA due to highly truncatred DNA repair mechanisms all contribute to sperm genome hypermutability and persistant oxidative DNA damage. Oxidative stress is also associated with genome wide hypomethylation, telomere shortening and mitochondrial dysfunction leading to genome hypermutability and instability. To the best of our knowledge, this is the first study to report decline in OS and ODD and improvement in sperm DNA integrity following adoption of meditation and yoga based life style modification.This may reduce disease burden in next generation and reduce incidence of childhood cancers.

신선 고환조직 정자와 냉동보존-융해 고환조직 정자를 이용한 난자세포질내 정자주입술 결과의 비교 연구 (Comparison of ICSI Outcomes between Fresh and Cryopreserved-Thawed Testicular Spermatozoa)

  • 최영식;최영민;김수웅;백재승;지병철;구승엽;서창석;김석현;김정구;문신용
    • Clinical and Experimental Reproductive Medicine
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    • 제35권2호
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    • pp.131-141
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    • 2008
  • 목 적: 무정자증 불임부부에서 신선 (fresh) 고환정자 (testicular spermatozoa)와 냉동보존-융해(cryopreserved-thawed) 고환정자를 사용한 난자세포질내 정자주입술 (intracytoplasmic sperm injection, ICSI)의 결과를 비교하고자 하였다. 연구방법: 신선 고환정자 및 냉동보존-융해 고환정자를 사용하여 ICSI 시술을 시행하기로 계획된 총 109주기 (66명)를 대상으로 하였고 신선 고환정자를 사용하기로 계획한 군 (신선 고환정자군, fresh group)에는 92주기 (61명)이 포함되었고 냉동보존-융해 고환정자를 사용하기로 계획한 군 (냉동보존-융해 고환정자군, cryopreserved-thawed group)에는 17주기 (13명)가 포함되었다. 양 군간에 수정률, 착상률, 임신률, 유산률 등 ICSI 시술의 결과들을 비교하였고 통계학적 분석은 Mann-Whitney U 검정 및 Fisher의 정확한 검정을 적절하게 사용하였다. 결 과: 신선 고환정자를 사용하여 ICSI 시술을 시행하기로 계획된 총 92주기 중 9주기에서 고환정자를 추출할 수 없어 시술 주기가 취소되었다. 냉동보존-융해 고환정자군과 비교하여 신선 고환정자군에서 수정률이 높은 경향을 보였고 ($58.0{\pm}27.8%$ vs. $45.9{\pm}25.0%$, p=0.076) 양질의 배아 수는 통계적으로 유의하게 높았다 ($0.9{\pm}1.2$ vs. $0.2{\pm}0.5$, p=0.002). 그러나 임상적 임신율, 착상률, 유산율은 양 군간에 통계적으로 유의한 차이가 없었다. 결 론: ICSI 시술을 위하여 냉동보존-융해 고환정자를 사용하는 경우 수정률 및 배아의 질이 감소하지만 임신율, 착상률, 유산율에는 영향을 미치지 않는 것으로 사료된다. 또한, ICSI 시술이전에 고환정자를 확보하고 냉동보존-융해 고환정자를 사용한다면 난자채취 당일 정자를 확보하지 못하여 주기를 취소하는 경우나 여성배우자의 불필요한 과배란유도를 줄일 수 있으며 반복적인 고환정자추출술로 인한 고환기능의 손상을 줄일 수 있는 유용한 방법으로 사료된다.