• Title/Summary/Keyword: head formation

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Positional Cloning of Novel Genes in Zebrafish Developmental Mutants

  • Kim, Cheol-Hee
    • 한국발생생물학회:학술대회논문집
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    • 한국발생생물학회 2003년도 제3회 국제심포지움 및 학술대회
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    • pp.24-25
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    • 2003
  • The zebrafish (Danio rerio) is now the pre-eminent vertebrate model system for clarification of the roles of specific genes and signaling pathways in development. I will talk about positional cloning of two developmental mutants in zebrafish. The first mutant is headless: The vertebrate organizer can induce a complete body axis when transplanted to the ventral side of a host embryo by virtue of its distinct head and trunk inducing properties. Wingless/Wntantagonists secreted by the organizer have been identified as head inducers. Their ectopic expression can promote head formation, whereas ectopic activation of Wnt signalling during early gastrulation blocks head formation. These observations suggest that the ability of head inducers to inhibit Wntsignalling during formation of anterior structures is what distinguishes them from trunk inducers that permit the operation of posteriorizing Wnt signals. I describe the zebrafish headless (hdl) mutant and show that its severe head defects are due to a mutation in T-cell factor-3 (Tcf3), a member of the Tcf/Lef family. Loss of Tcf3 function in the hdl mutant reveals that hdl represses Wnt target genes. I provide genetic evidence that a component of the Wntsignalling pathway is essential in vertebrate head formation and patterning. Second mutant is mind bomb: Lateral inhibition, mediated by Notch signaling, leads to the selection of cells that are permitted to become neurons within domains defined by proneuralgene expression. Reduced lateral inhibition in zebrafish mib mutant embryos permits too many neural progenitors to differentiate as neurons. Positional cloning of mib revealed that it is a gene in the Notch pathway that encodes a RING ubiquitin ligase. Mib interacts with the intracellular domain of Delta to promote its ubiquitylation and internalization. Cell transplantation studies suggest that mib function is essential in the signaling cell for efficient activation of Notch in neighboring cells. (중략)

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결구 차이에 따른 양상추 신선편이 제품의 품질 비교 (Quality Evaluation of Minimally Processed Lettuce (Lactuca sativa L.) According to Degree of Head Formation)

  • 윤예리;권기현;김병삼;차환수
    • 한국식품과학회지
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    • 제40권4호
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    • pp.460-465
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    • 2008
  • 신선편이 가공 양상추의 결구 정도에 따른 저장 중 품질변화를 살펴보았다. 양상추는 결구 정도에 따라 70, 85, 100%로 분류하여 $3{\times}4cm$로 썰어 polypropylene(PP)과 polyethylene terephtha-late(PET) 재질로 되어있는 사각 용기 $(20{\times}15{\times}5$ cm)에 담아 질소 충진 후 $4^{\circ}C$의 저장고에서 8일 동안 저장하였다. 저장 초기 결구 70% 양상추의 당도가 $3.67^{\circ}Bx$였으며, 무기질 함량도 나트륨 25.04, 칼륨 186.03, 칼슘 18.62mg/100 g 둥으로 가장 높았다. 하지만 저장기간이 길어짐에 따른 결구정도와는 상관없이 무기질 함량이 감소하는 경향을 나타내었다. 또한 결구 70%인 양상추의 비타민 C 함량은 3.30 mg/100 g로 가장 높았으며, 양상추 외잎의 클로로필 함량 역시 결구 70%가 결구 100%에 비하여 3배 정도 높은 수치를 나타내었다. 씹힘성을 나타내는 양상추의 경도는 결구 70%인 양상추가 1,010 g이였으며, 결구 정도가 높아짐에 따라 경도가 증가하여 씹힘성이 증가하는 것으로 유추되어진다. PPO의 활성은 결구정도에 따라 240, 371, 566 unit/g로 각각 나타나 결구 70%에서 갈변이 최소한으로 나타났다. 이상의 결과로 결구 70%인 양상추를 이용하여 신선편이 가공 제품을 유통시킬 때 품질유지에 가장 효과적인 것으로 나타났다.

Inhibition of Asexual Speculation and Growth of Aspergillus niger and Aspergillus oryzae by Propylamine

  • SONG, MYUNG HOON;KUPPUSAMY SELVAM;HYO-YOUNG JEONG;KEON-SANG CHAE
    • Journal of Microbiology and Biotechnology
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    • 제13권1호
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    • pp.146-148
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    • 2003
  • Effects of propylamine on conidial head formation and growth of Aspergillus niger and Aspergillus oryzae were analyzed. Propylamine inhibited conidial head formation in these two fungi, and the inhibitory effect of propylamine was not suppressed by the addition of potassium chloride at high concentration, which promotes conidial head formation in A. nidulans and A. oryzae. Propylamine also inhibited the growth of A. niger and A. oryzae by $41\%\;and\;32\%$, respectively, when the concentration of propylamine was $2\%$.

Radiographic analysis of the management of tooth extractions in head and neck-irradiated patients: a case series

  • Oliveira, Samanta V.;Vellei, Renata S.;Heguedusch, Daniele;Domaneschi, Carina;Costa, Claudio;Gallo, Camila de Barros
    • Imaging Science in Dentistry
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    • 제51권3호
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    • pp.323-328
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    • 2021
  • Tooth extraction after head and neck radiotherapy exposes patients to an increased risk for osteoradionecrosis of the jaw. This study reports the results of a radiographic analysis of bone neoformation after tooth extraction in a case series of patients who underwent radiation therapy. No patients developed osteoradionecrosis within a follow-up of 1 year. Complete mucosal repair was observed 30 days after surgery, while no sign of bone formation was observed 2 months after the dental extractions. Pixel intensity and fractal dimension image analyses only showed significant bone formation 12 months after the tooth extractions. These surgical procedures must follow a strict protocol that includes antibiotic prophylaxis and therapy and complete wound closure, since bone formation at the alveolar socket occurs at a slower pace in patients who have undergone head and neck radiotherapy.

Analysis of 120 Pectoralis Major Flaps for Head and Neck Reconstruction

  • You, Young Sun;Chung, Chul Hoon;Chang, Yong Joon;Kim, Kuyl Hee;Jung, Sung Won;Rho, Young Soo
    • Archives of Plastic Surgery
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    • 제39권5호
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    • pp.522-527
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    • 2012
  • Background A pectoralis major flap is one of the standard tools for the reconstruction of defects of the head and neck. Despite the technical advancement in free tissue transfer in head and neck reconstruction, the benefits of a pectoralis major flap should not be overlooked. The purpose of this study is to evaluate our 17 years of experience in reconstructing defects of the head and neck region using the pectoralis major flap. Methods We retrospectively reviewed the medical records of 112 patients (120 cases) who underwent pectoralis major flap operations for head and neck reconstruction during a period ranging from 1994 to 2010. Results In our series, no total necrosis of the flap occurred. Of the total cases, 30.8% presented with flap-related complications. Major complications occurred in 20% of all of the cases but were then all successfully treated. The male sex was correlated with the occurrence of overall complications (P=0.020) and major complications (P=0.007). Preoperative albumin levels of <3.8 g/dL were correlated with the formation of fistula (P=0.030). Defects of the hypopharynx were correlated with the occurrence of major complications (P=0.019) and the formation of fistula (P=0.012). Secondary reconstructions were correlated with the occurrence of overall complications (P=0.013) and the formation of fistula (P=0.030). Conclusions A pectoralis major flap is still considered to be a safe, versatile one-stage reconstruction procedure in the management of the defects of head and neck and the protection of the carotid artery.

The Formation of Managerial Competence of the Future Head of Preschool Education by Means of Information and Communication Technologies

  • Nataliia, Dudnyk;Valentyna, Kryvda;Svitlana, Popychenco;Nelia, Skrypnyk;Tetiana, Duka
    • International Journal of Computer Science & Network Security
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    • 제22권9호
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    • pp.287-299
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    • 2022
  • The article deals with the formation of managerial competence of the future head of preschool education institution by means of information and communication technology as a prerequisite for his ability to act competently and objectively evaluate actions and understand the interaction of forms and content of preschool education. The article aimed to study the effectiveness of information and communication technologies in the formation of managerial competence of the future head of preschool education institution. To achieve the objectives, the methods of comparative and systematic analysis were used to compare different views on the problem under study, namely, the formation of managerial competence of the future head of preschool education institution by means of information and communication technologies. The authors of the article determined that the use of information and communication technologies in the preparation of future heads of preschool educational institutions is of great importance and is an indicator in the structure of managerial competence. The priority directions of the use of various software products for the study of the modern Ukrainian language, methods of teaching the Ukrainian language contribute to the intensification of learning material. It is noted that the current state of development of information technologies and their widespread use in education satisfies the requirements of the objectivity of the assessment obtained the quality of the control process of forming the managerial competence of the future leader in the context of the general problems of pre-school education. It is noted that the means of information and communication technologies play a leading role in creating new educational policies and projects, as they motivate the way of access to knowledge.

세침흡인검사 후 호흡곤란을 동반한 일측성 갑상선 혈종 2례 (Two Cases of Unilateral Thyroid Hematoma Inducing Airway Distress after Fine Needle Aspiration Biopsy)

  • 변장열;권계원;고윤우
    • 대한두경부종양학회지
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    • 제23권1호
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    • pp.54-57
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    • 2007
  • Fine needle aspiration biopsy(FNAB) has been used for many decades in the diagnosis of benign and malignant tumors of thyroid gland. Complications of thyroid fine-needle aspiration biopsy(FNAB) are extremely rare. Hematoma formation is the most commonly encountered complication. However, massive intrathyroid unilateral hemorrhage and hematoma formation inducing upper airway distress rarely occurs. Here, we report two cases diagnosed as having hematoma that caused upper airway distress after FNAB for thyroid nodule.

Development of Energy-sensitive Cluster Formation and Cluster Head Selection Technique for Large and Randomly Deployed WSNs

  • Sagun Subedi;Sang Il Lee
    • Journal of information and communication convergence engineering
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    • 제22권1호
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    • pp.1-6
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    • 2024
  • Energy efficiency in wireless sensor networks (WSNs) is a critical issue because batteries are used for operation and communication. In terms of scalability, energy efficiency, data integration, and resilience, WSN-cluster-based routing algorithms often outperform routing algorithms without clustering. Low-energy adaptive clustering hierarchy (LEACH) is a cluster-based routing protocol with a high transmission efficiency to the base station. In this paper, we propose an energy consumption model for LEACH and compare it with the existing LEACH, advanced LEACH (ALEACH), and power-efficient gathering in sensor information systems (PEGASIS) algorithms in terms of network lifetime. The energy consumption model comprises energy-sensitive cluster formation and a cluster head selection technique. The setup and steady-state phases of the proposed model are discussed based on the cluster head selection. The simulation results demonstrated that a low-energy-consumption network was introduced, modeled, and validated for LEACH.

Effect of Cycloheximide on Bovine Oocyte Nuclear Progression and Sperm Head Transformation after Fertilization In Vitro

  • Liu, L.;Zhang, H.W.;Qian, J.F.;Fujihara, N.
    • Asian-Australasian Journal of Animal Sciences
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    • 제12권1호
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    • pp.22-27
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    • 1999
  • Bovine oocytes with compact and complete cumulus cells were cultured in 6 groups for up to 24h in TCM199 buffered with 25 mmol/1 HEPES and supplemented with 10% FCS, 1 mg/ml $17{\beta}$-estradiol, 20 IU/ml hCG. Half of the oocytes at each group cultured in the presence of $25{\mu}g/ml$ cycloheximide at different times during maturation (0, 6, 12, 18, 20, 22 h) were fixed at 24 h of maturation to examine the nuclear progression. The rests of them were inseminated with frozen-thawed spermatozoa in medium BO with 10 mg/ml BSA and 10 mg/ml heparin and fixed after additional 18-20 h culture to evaluate the sperm head transformation. When a protein synthesis inhibitor was added at the onset of the maturation, the oocytes were prevented to proceed GVBD. A few of the oocytes (16%) were able to be penetrated and sperm head decondensation was inhibited either. Addition of cycloheximide after 6-12 h of culture resulted in an increasing percentage of GVBCD (more than 80%), but the oocytes became arrested in M-I (69.2%). More than half of the oocytes was penetrated with a decondensing sperm head. Formation of male pronucleus was first obtained at 12 h of culture in the presence of cycloheximide. When cycloheximide was added from 18 h of culture onwards, nuclear progression to M-II was increasingly restored (80.4-85.5%). The proportion of male and female pronuclear formation increased from 17.9% to 46.2%. It is concluded that protein synthesis is necessary not only for GVBD and development from M-I to M-II, but also for sperm head decendensation and male pronuclear formation in bovine oocytes.