• Title/Summary/Keyword: Molecular approach

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Treatment Decisions of World Health Organization Grade II and III Ependymomas in Molecular Era

  • Jung, Tae-Young;Jung, Shin;Kook, Hoon;Baek, Hee-Jo
    • Journal of Korean Neurosurgical Society
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    • v.61 no.3
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    • pp.312-318
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    • 2018
  • Surgery and radiotherapy are mainstays of treatment for ependymomas (EPNs). Recent molecular subgrouping could be superior to histopathological grading for predicting the prognosis of patients with EPNs. Gross total resection is an effective treatment approach regardless of its locations or pathologic grades. Adjuvant therapeutic strategies could be decided based on molecular subgrouping with risk-stratification. Information of histologic-molecular biology is now providing clues to therapeutic insights.

Molecular dynamics simulations approaches for discovering anti-influenza drug

  • Cho, Sungjoon;Choi, Youngjin
    • CELLMED
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    • v.6 no.4
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    • pp.24.1-24.4
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    • 2016
  • The emergence of influenza virus and antigenic drift are potential cause of world-wide pandemic. There are some commercially available drugs in the market to treat influenza. During past decade, however, critical resistances have been raised for biological targets. Because of structural complexity and flexibility of target proteins, applying a computational modeling tool is very beneficial for developing alternative anti-influenza drugs. In this review, we introduced molecular dynamics (MD) simulations approach to reflect full conformational flexibility of proteins during molecular modeling works. Case studies of MD works were summarized for the drug discovery and drug resistance mechanism of anti-influenza pharmaceuticals.

Treatment of chemotherapy-related peripheral neuropathy with traditional Chinese medicine from the perspective of blood-arthralgia Zheng

  • Cao, Peng;Yang, Jie;Cai, Xueting;Wang, Xiaoning;Huo, Jiege
    • CELLMED
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    • v.2 no.4
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    • pp.30.1-30.4
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    • 2012
  • Traditional Chinese medicine classifies peripheral nerve impairment as paralysis and arthromyodynia, and considers that it is the result of defects of meridians and vessels, QI and blood, bones and muscles. Huangqi (Astragalus) Guizhi (Cassia Twig) Wuwu Tang, as a Qi invigorating formula, is usually used to improve peripheral nerve impairment. In recent years, some scholars have conducted research into Chemotherapy-induced peripheral neuropathy (CIPN) treatment with Huangqi Guizhi Wuwu Tang and certain values of this treatment approach have been identified. CIPN is a type of blood-arthralgia Zheng in traditional Chinese medicine theory. In this review, we will discuss the treatment of CIPN with Huangqi Guizhi Wuwu Tang according to blood-arthtalgia Zheng.

Biopsy and Mutation Detection Strategies in Non-Small Cell Lung Cancer

  • Jung, Chi Young
    • Tuberculosis and Respiratory Diseases
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    • v.75 no.5
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    • pp.181-187
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    • 2013
  • The emergence of new therapeutic agents for non-small cell lung cancer (NSCLC) implies that histologic subtyping and molecular predictive testing are now essential for therapeutic decisions. Histologic subtype predicts the efficacy and toxicity of some treatment agents, as do genetic alterations, which can be important predictive factors in treatment selection. Molecular markers, such as epidermal growth factor receptor (EGFR) mutation and anaplastic lymphoma kinase (ALK) rearrangement, are the best predictors of response to specific tyrosine kinase inhibitor treatment agents. As the majority of patients with NSCLC present with unresectable disease, it is therefore crucial to optimize the use of tissue samples for diagnostic and predictive examinations, particularly for small biopsy and cytology specimens. Therefore, each institution needs to develop a diagnostic approach requiring close communication between the pulmonologist, radiologist, pathologist, and oncologist in order to preserve sufficient biopsy materials for molecular analysis as well as to ensure rapid diagnosis. Currently, personalized medicine in NSCLC is based on the histologic subtype and molecular status. This review summarizes strategies for tissue acquisition, histologic subtyping and molecular analysis for predictive testing in NSCLC.

Fragile-X Mental Retardation: Molecular Diagnosis in Argentine Patients

  • Florencia, Giliberto;Irene, Szijan;Veronica, Ferreiro
    • BMB Reports
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    • v.39 no.6
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    • pp.766-773
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    • 2006
  • Fragile-X-syndrome (FXS) is the most common type of inherited cognitive impairment. The underlying molecular alteration consists of a CGG-repeat amplification within the FMR-1 gene. The phenotype is only apparent once a threshold in the number of repeats has been exceeded (full mutation). The aim of this study was to characterize the FMR-1 CGG-repeat status in Argentine patients exhibiting mental retardation. A total of 330 blood samples from patients were analyzed by PCR and Southern blot analysis. Initially, DNA from 78 affected individuals were studied by PCR. Since this method is unable to detect high molecular weight alleles, however, we undertook a second approach using the Southern blotting technique to analyze the CGG repeat number and methylation status. Southern blot analysis showed an altered pattern in 14 out of 240 (6%) unrelated patients, with half of them presenting a mosaic pattern. Eight out of 17 families (47%) showed a (suggest deleting highlight). The characteristic FXS pattern was identified in 8/17 families (47%), and in 4 of these families 25% of the individuals presented with a mosaic model. The expansion from pre-mutation to full mutation was shown to occur both at the pre and post zygotic levels. The detection of FXS mutations has allowed us to offer more informed genetic counseling, prenatal diagnosis and reliable patient follow-up.

Two Conserved Scalar Approach for the Turbulent Nonpremixed Flames (다중 혼합기 난류 비예혼합 연소시스템에 대한 수치모델링)

  • Kim, Gun-Hong;Kang, Sung-Mo;Kim, Yong-Mo;Ahn, Kook-Young
    • 한국연소학회:학술대회논문집
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    • 2003.12a
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    • pp.57-61
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    • 2003
  • In the combustion modeling of non-premixed flames, the mixture fraction conserved scalar approach is widely utilized because reactants are mixed at the molecular level before burning and atomic elements are conserved in chemical reactions. In the mixture fraction approach, combustion process is simplified to a mixing problem and the interaction between chemistry and turbulence could be modelled by many sophisticated combustion models including the flamelet model and CMC. However, most of the mixture fraction approach is restricted to one mixture system. In this study, the flamelet model based on the two-feed system is extended to the multiple fuel-feeding systems by the two mixture fraction conserved scalar approach.

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Recent Advances in Gut Microbiology and Their Possible Contribution to Animal Health and Production - A Review -

  • Kobayashi, Yasuo;Koike, Satoshi;Taguchi, Hidenori;Itabashi, Hisao;Kam, Dong K.;Ha, Jong K.
    • Asian-Australasian Journal of Animal Sciences
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    • v.17 no.6
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    • pp.877-884
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    • 2004
  • Although gut microbial functions have been analyzed through cultivation of isolated microbes, molecular analysis without cultivation is becoming a popular approach in recent years. Gene cloning studies have partially revealed the mechanisms involved in fiber digestion of individual microbe. The molecular approach finally made it possible to analyze full genomes of the representative rumen cellulolytic bacteria Fibrobacter and Ruminococcus. The coming database may contain useful information such as regulation of gene expression relating to fiber digestion. Meanwhile, unculturable bacteria are still poorly characterized, even though they are main constituents of gut microbial ecosystem. The molecular analysis is essential to initiating the studies on these unculturable bacteria. The studies dealing with rumen and large intestine are revealing considerable complexity of the microbial ecosystems with many undescribed bacteria. These bacteria are being highlighted as possibly functional members contributing to feed digestion. Manipulation of gut bacteria and gut ecology for improving animal production is still at challenging stage. Bacteria newly introduced in the rumen, whether they are genetically modified or not, suffer from poor survival. In one of these attempts, Butyrivibrio fibrisolvens expressing a foreign dehalogenase was successfully established in sheep rumen to prevent fluoroacetate poisoning. This expands choice of forages in tropics, since many tropic plants are known to contain the toxic fluoroacetate. This example may promise the possible application of molecular breeding of gut bacteria to the host animals with significance in their health and nutrition. When inoculation strategies for such foreign bacteria are considered, it is obvious that we should have more detailed information of the gut microbial ecology.

Evaluation of Crack-tip Cohesive Laws for the Mode I Fracture of the Graphene from Molecular Dynamics Simulations (그래핀의 모드 I 균열에 대한 분자동역학 해석으로부터 균열 선단 응집 법칙의 평가)

  • Kim, Hyun-Gyu
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.26 no.5
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    • pp.393-399
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    • 2013
  • In this paper, a novel approach to estimate cohesive laws for the mode I fracture of the graphene is presented by combining molecular dynamic simulations and an inverse algorithm based on field projection method and finite element method. The determination of crack-tip cohesive laws of the graphene based on continuum mechanics is a non-trivial inverse problem of finding unknown tractions and separations from atomic simulations. The displacements of molecular dynamic simulations in a region far away from the crack tip are transferred to finite element nodes by using moving least square approximation. Inverse analyses for extracting unknown cohesive tractions and separation behind the crack tip can be carried out by using conservation nature of the interaction J- and M-integrals with numerical auxiliary fields which are generated by systematically imposing uniform surface tractions element-by-element along the crack surfaces in finite element models. The preset method can be a very successful approach to extract crack-tip cohesive laws from molecular dynamic simulations as a scale bridging method.

A Novel Approach to Controlling CaCO3 Crystalline Assembly by Changing the Concentration of Poly(aspartic acid)

  • Zhou, Hongjian;Gao, Yanmin;Hwang, Sun-Gu;Lee, Dong-Yun;Park, Jung-Youn;Lee, Jae-Beom
    • Bulletin of the Korean Chemical Society
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    • v.32 no.11
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    • pp.4027-4034
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    • 2011
  • $CaCO_3$ crystalline structures having novel assemblies were in situ fabricated as analogs of naturally occurring proteins and polysaccharides for biomineralization. The calcite crystal was mineralized in a poly(vinyl alcohol)-$Ca^{2+}$ complex film immersed in a $Na_2CO_3$ solution containing poly(aspartic acid). The morphology and size of the $CaCO_3$ crystals were tuned by varying the concentration of poly(aspartic acid). The mechanisms of their nucleation orientation and formation were investigated experimentally and through molecular dynamics (MD) simulations in order to obtain a better understanding of the interactions between the polymers and the crystal at the molecular level. Both the MD results and experimental results indicate that the interaction between PVA and calcite mainly depends on the concentration of the polymer. The novel approach proposed herein for the fabrication of inorganic crystalline assembly structures can be used to fabricate precise crystalline structures.

Crack growth prediction and cohesive zone modeling of single crystal aluminum-a molecular dynamics study

  • Sutrakar, Vijay Kumar;Subramanya, N.;Mahapatra, D. Roy
    • Advances in nano research
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    • v.3 no.3
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    • pp.143-168
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    • 2015
  • Initiation of crack and its growth simulation requires accurate model of traction - separation law. Accurate modeling of traction-separation law remains always a great challenge. Atomistic simulations based prediction has great potential in arriving at accurate traction-separation law. The present paper is aimed at establishing a method to address the above problem. A method for traction-separation law prediction via utilizing atomistic simulations data has been proposed. In this direction, firstly, a simpler approach of common neighbor analysis (CNA) for the prediction of crack growth has been proposed and results have been compared with previously used approach of threshold potential energy. Next, a scheme for prediction of crack speed has been demonstrated based on the stable crack growth criteria. Also, an algorithm has been proposed that utilizes a variable relaxation time period for the computation of crack growth, accurate stress behavior, and traction-separation atomistic law. An understanding has been established for the generation of smoother traction-separation law (including the effect of free surface) from a huge amount of raw atomistic data. A new curve fit has also been proposed for predicting traction-separation data generated from the molecular dynamics simulations. The proposed traction-separation law has also been compared with the polynomial and exponential model used earlier for the prediction of traction-separation law for the bulk materials.