LIVIVO - The Search Portal for Life Sciences

zur deutschen Oberfläche wechseln
Advanced search

Search results

Result 1 - 10 of total 41

Search options

  1. Article ; Online: Nitrogen Fixation at the Edges of Boron Nitride Nanomaterials

    Venkata Surya Kumar Choutipalli / Karthikraja Esackraj / Venkatesan Subramanian

    Frontiers in Chemistry, Vol

    Synergy of Doping

    2022  Volume 9

    Abstract: Synthesis of ammonia at ambient conditions is very demanding yet challenging to achieve due to the production of ammonia fuel, which is considered to be a future fuel for sustainable energy. In this context, computational studies on the catalytic ... ...

    Abstract Synthesis of ammonia at ambient conditions is very demanding yet challenging to achieve due to the production of ammonia fuel, which is considered to be a future fuel for sustainable energy. In this context, computational studies on the catalytic activity of the edge sites of boron nitride nanomaterials for possible nitrogen reduction into ammonia have been investigated. Geometrical and electronic properties of zigzag and armchair B-open edges of BN sheet (BOE) models have been unraveled to substantiate their catalytic nature. Results reveal that BOE sites exhibit very high potential determining steps (PDS) of 2.0 eV. Doping of carbon (C) at the nitrogen center, which is vicinal to the BOE site reduces the PDS of the N2 reduction reaction (NRR) (to 1.18–1.33 eV) due to the regulation of charge distribution around the active BOE site. Further, the NRR at the C doped at various edge sites of a boron nitride sheet (BNS) has also been studied in detail. Among the 12 new C-doped defective BNS models, 9 model catalysts are useful for nitrogen activation through either chemisorption or physisorption. Among these, ZCN, ACN, and ZCBV models are efficient in catalyzing NRR with lower PDS of 0.86, 0.88, and 0.86 eV, respectively. The effect of carbon doping in tuning the potential requirements of NRR has been analyzed by comparing the relative stability of intermediates on the catalyst with and without carbon doping. Results reveal that C-doping destabilizes the intermediates compared to non-doped systems, thereby reducing the possibility of catalyst poisoning. However, their interactions with catalysts are good enough so that the NRR activity of the catalyst does not decrease due to C-doping.
    Keywords nitrogen reduction ; catalysis ; small molecules activation ; DFT ; doping ; boron nitride ; Chemistry ; QD1-999
    Subject code 540
    Language English
    Publishing date 2022-01-01T00:00:00Z
    Publisher Frontiers Media S.A.
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    Full text online

    More links

    Kategorien

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  2. Article ; Online: Assessment of Amyloid Forming Tendency of Peptide Sequences from Amyloid Beta and Tau Proteins Using Force-Field, Semi-Empirical, and Density Functional Theory Calculations

    Charuvaka Muvva / Natarajan Arul Murugan / Venkatesan Subramanian

    International Journal of Molecular Sciences, Vol 22, Iss 3244, p

    2021  Volume 3244

    Abstract: A wide variety of neurodegenerative diseases are characterized by the accumulation of protein aggregates in intraneuronal or extraneuronal brain regions. In Alzheimer’s disease (AD), the extracellular aggregates originate from amyloid-β proteins, while ... ...

    Abstract A wide variety of neurodegenerative diseases are characterized by the accumulation of protein aggregates in intraneuronal or extraneuronal brain regions. In Alzheimer’s disease (AD), the extracellular aggregates originate from amyloid-β proteins, while the intracellular aggregates are formed from microtubule-binding tau proteins. The amyloid forming peptide sequences in the amyloid-β peptides and tau proteins are responsible for aggregate formation. Experimental studies have until the date reported many of such amyloid forming peptide sequences in different proteins, however, there is still limited molecular level understanding about their tendency to form aggregates. In this study, we employed umbrella sampling simulations and subsequent electronic structure theory calculations in order to estimate the energy profiles for interconversion of the helix to β-sheet like secondary structures of sequences from amyloid-β protein (KLVFFA) and tau protein (QVEVKSEKLD and VQIVYKPVD). The study also included a poly-alanine sequence as a reference system. The calculated force-field based free energy profiles predicted a flat minimum for monomers of sequences from amyloid and tau proteins corresponding to an α-helix like secondary structure. For the parallel and anti-parallel dimer of KLVFFA, double well potentials were obtained with the minima corresponding to α-helix and β-sheet like secondary structures. A similar double well-like potential has been found for dimeric forms for the sequences from tau fibril. Complementary semi-empirical and density functional theory calculations displayed similar trends, validating the force-field based free energy profiles obtained for these systems.
    Keywords Alzheimer’s disease ; amyloid-β peptide ; amyloid forming peptides ; Tau protein ; umbrella sampling simulations ; free energy calculations ; Biology (General) ; QH301-705.5 ; Chemistry ; QD1-999
    Subject code 612
    Language English
    Publishing date 2021-03-01T00:00:00Z
    Publisher MDPI AG
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    Full text online

    More links

    Kategorien

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  3. Article: Deciphering the mechanism of

    Nandan, Amrita / Sharma, Vishwas / Banerjee, Prodyot / Sadasivam, Kannan / Venkatesan, Subramanian / Prasher, Bhavana

    Frontiers in pharmacology

    2023  Volume 13, Page(s) 1056677

    Abstract: ... Naive ... ...

    Abstract Naive CD4
    Language English
    Publishing date 2023-01-09
    Publishing country Switzerland
    Document type Journal Article
    ZDB-ID 2587355-6
    ISSN 1663-9812
    ISSN 1663-9812
    DOI 10.3389/fphar.2022.1056677
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

  4. Article: Investigating chromosomal instability in long-term survivors with glioblastoma and grade 4 astrocytoma.

    Spoor, Jochem K H / den Braber, May / Dirven, Clemens M F / Pennycuick, Adam / Bartkova, Jirina / Bartek, Jiri / van Dis, Vera / van den Bosch, Thierry P P / Leenstra, Sieger / Venkatesan, Subramanian

    Frontiers in oncology

    2024  Volume 13, Page(s) 1218297

    Abstract: Background: Only a small group of patients with glioblastoma multiforme (GBM) survives more than 36 months, so-called long-term survivors. Recent studies have shown that chromosomal instability (CIN) plays a prognostic and predictive role among ... ...

    Abstract Background: Only a small group of patients with glioblastoma multiforme (GBM) survives more than 36 months, so-called long-term survivors. Recent studies have shown that chromosomal instability (CIN) plays a prognostic and predictive role among different cancer types. Here, we compared histological (chromosome missegregation) and bioinformatic metrics (CIN signatures) of CIN in tumors of GBM typical survivors (≤36 months overall survival), GBM long-term survivors and isocitrate dehydrogenase (IDH)-mutant grade 4 astrocytomas.
    Methods: Tumor sections of all gliomas were examined for anaphases and chromosome missegregation. Further CIN signature activity analysis in the The Cancer Genome Atlas (TCGA)-GBM cohort was performed.
    Results: Our data show that chromosome missegregation is pervasive in high grade gliomas and is not different between the 3 groups. We find only limited evidence of altered CIN levels in tumors of GBM long-term survivors relative to the other groups, since a significant depletion in CIN signature 11 relative to GBM typical survivors was the only alteration detected. In contrast, within IDH-mutant grade 4 astrocytomas we detected a significant enrichment of CIN signature 5 and 10 activities and a depletion of CIN signature 1 activity relative to tumors of GBM typical survivors.
    Conclusions: Our data suggest that CIN is pervasive in high grade gliomas, however this is unlikely to be a major contributor to the phenomenon of long-term survivorship in GBM. Nevertheless, further evaluation of specific types of CIN (signatures) could have prognostic value in patients suffering from grade 4 gliomas.
    Language English
    Publishing date 2024-01-08
    Publishing country Switzerland
    Document type Journal Article
    ZDB-ID 2649216-7
    ISSN 2234-943X
    ISSN 2234-943X
    DOI 10.3389/fonc.2023.1218297
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

  5. Article: Genetic Diversity and Structure of

    Umesh Kanna, Subramani / Parthiban, Kalappan Thangamuthu / Senthilraja, Kandasamy / Venkatesan, Subramanian / Udhaya Nandhini, Dhandayuthapani / Mohan Kumar, Shanmugam / Dhasarathan, Manickam / Kumaresan, Palaniyappan / Sai, Makkena Jaswanth / Raveendran, Muthurajan / Geethalakshmi, Vellingiri

    Plants (Basel, Switzerland)

    2024  Volume 13, Issue 4

    Abstract: In this study, an extensive exploration survey of wild progeny was conducted which yielded 18 candidate plus trees (CPTs) ... ...

    Abstract In this study, an extensive exploration survey of wild progeny was conducted which yielded 18 candidate plus trees (CPTs) of
    Language English
    Publishing date 2024-02-06
    Publishing country Switzerland
    Document type Journal Article
    ZDB-ID 2704341-1
    ISSN 2223-7747
    ISSN 2223-7747
    DOI 10.3390/plants13040470
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

  6. Article ; Online: Tumor Evolutionary Principles: How Intratumor Heterogeneity Influences Cancer Treatment and Outcome.

    Venkatesan, Subramanian / Swanton, Charles

    American Society of Clinical Oncology educational book. American Society of Clinical Oncology. Annual Meeting

    2016  Volume 35, Page(s) e141–9

    Abstract: Recent studies have shown that intratumor heterogeneity contributes to drug resistance in advanced disease. Intratumor heterogeneity may foster the selection of a resistant subclone, sometimes detectable prior to treatment. Next-generation sequencing is ... ...

    Abstract Recent studies have shown that intratumor heterogeneity contributes to drug resistance in advanced disease. Intratumor heterogeneity may foster the selection of a resistant subclone, sometimes detectable prior to treatment. Next-generation sequencing is enabling the phylogenetic reconstruction of a cancer's life history and has revealed different modes of cancer evolution. These studies have shown that cancer evolution is not always stochastic and has certain constraints. Consideration of cancer evolution may enable the better design of clinical trials and cancer therapeutics. In this review, we summarize the different modes of cancer evolution and how this might impact clinical outcomes. Furthermore, we will discuss several therapeutic strategies for managing emergent intratumor heterogeneity.
    MeSH term(s) Evolution, Molecular ; Genetic Heterogeneity ; Humans ; Mutation/genetics ; Neoplasms/genetics ; Neoplasms/pathology ; Neoplasms/therapy ; Phylogeny
    Language English
    Publishing date 2016-04-13
    Publishing country United States
    Document type Journal Article ; Review
    ZDB-ID 2431126-1
    ISSN 1548-8756 ; 1548-8748
    ISSN (online) 1548-8756
    ISSN 1548-8748
    DOI 10.14694/EDBK_158930
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

  7. Article ; Online: Cp-Graphyne

    Naga Venkateswara Rao Nulakani / Venkatesan Subramanian

    ACS Omega, Vol 2, Iss 10, Pp 6822-

    A Low-Energy Graphyne Polymorph with Double Distorted Dirac Points

    2017  Volume 6830

    Keywords Chemistry ; QD1-999
    Language English
    Publishing date 2017-10-01T00:00:00Z
    Publisher American Chemical Society
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    Full text online

    More links

    Kategorien

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  8. Article ; Online: Performance of Force-Field- and Machine Learning-Based Scoring Functions in Ranking MAO-B Protein–Inhibitor Complexes in Relevance to Developing Parkinson’s Therapeutics

    Natarajan Arul Murugan / Charuvaka Muvva / Chitra Jeyarajpandian / Jeyaraman Jeyakanthan / Venkatesan Subramanian

    International Journal of Molecular Sciences, Vol 21, Iss 7648, p

    2020  Volume 7648

    Abstract: Monoamine oxidase B (MAOB) is expressed in the mitochondrial membrane and has a key role in degrading various neurologically active amines such as benzylamine, phenethylamine and dopamine with the help of Flavin adenine dinucleotide (FAD) cofactor. The ... ...

    Abstract Monoamine oxidase B (MAOB) is expressed in the mitochondrial membrane and has a key role in degrading various neurologically active amines such as benzylamine, phenethylamine and dopamine with the help of Flavin adenine dinucleotide (FAD) cofactor. The Parkinson’s disease associated symptoms can be treated using inhibitors of MAO-B as the dopamine degradation can be reduced. Currently, many inhibitors are available having micromolar to nanomolar binding affinities. However, still there is demand for compounds with superior binding affinity and binding specificity with favorable pharmacokinetic properties for treating Parkinson’s disease and computational screening methods can be majorly recruited for this. However, the accuracy of currently available force-field methods for ranking the inhibitors or lead drug-like compounds should be improved and novel methods for screening compounds need to be developed. We studied the performance of various force-field-based methods and data driven approaches in ranking about 3753 compounds having activity against the MAO-B target. The binding affinities computed using autodock and autodock-vina are shown to be non-reliable. The force-field-based MM-GBSA also under-performs. However, certain machine learning approaches, in particular KNN, are found to be superior, and we propose KNN as the most reliable approach for ranking the complexes to reasonable accuracy. Furthermore, all the employed machine learning approaches are also computationally less demanding.
    Keywords binding free energy calculations ; molecular docking ; monoamine oxidase B ; Parkinson’s disease ; machine learning approach ; Biology (General) ; QH301-705.5 ; Chemistry ; QD1-999
    Subject code 540
    Language English
    Publishing date 2020-10-01T00:00:00Z
    Publisher MDPI AG
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    Full text online

    More links

    Kategorien

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  9. Article: APOBEC3 as a driver of genetic intratumor heterogeneity.

    Venkatesan, Subramanian / Angelova, Mihaela / Bartkova, Jirina / Bakhoum, Samuel F / Bartek, Jiri / Kanu, Nnennaya / Swanton, Charles

    Molecular & cellular oncology

    2022  Volume 10, Issue 1, Page(s) 2014734

    Abstract: Our recent study revealed that APOBEC3B is upregulated during the preinvasive stages of non-small cell lung cancer and breast cancer. In addition to its role in mediating single nucleotide variants, we propose that APOBEC3 promotes copy number intratumor ...

    Abstract Our recent study revealed that APOBEC3B is upregulated during the preinvasive stages of non-small cell lung cancer and breast cancer. In addition to its role in mediating single nucleotide variants, we propose that APOBEC3 promotes copy number intratumor heterogeneity prior to invasion, providing a substrate for cancer evolution.
    Language English
    Publishing date 2022-01-03
    Publishing country United States
    Document type Journal Article
    ISSN 2372-3556
    ISSN 2372-3556
    DOI 10.1080/23723556.2021.2014734
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  10. Article ; Online: Constraints in cancer evolution.

    Venkatesan, Subramanian / Birkbak, Nicolai J / Swanton, Charles

    Biochemical Society transactions

    2017  Volume 45, Issue 1, Page(s) 1–13

    Abstract: Next-generation deep genome sequencing has only recently allowed us to quantitatively dissect the extent of heterogeneity within a tumour, resolving patterns of cancer evolution. Intratumour heterogeneity and natural selection contribute to resistance to ...

    Abstract Next-generation deep genome sequencing has only recently allowed us to quantitatively dissect the extent of heterogeneity within a tumour, resolving patterns of cancer evolution. Intratumour heterogeneity and natural selection contribute to resistance to anticancer therapies in the advanced setting. Recent evidence has also revealed that cancer evolution might be constrained. In this review, we discuss the origins of intratumour heterogeneity and subsequently focus on constraints imposed upon cancer evolution. The presence of (1) parallel evolution, (2) convergent evolution and (3) the biological impact of acquiring mutations in specific orders suggest that cancer evolution may be exploitable. These constraints on cancer evolution may help us identify cancer evolutionary rule books, which could eventually inform both diagnostic and therapeutic approaches to improve survival outcomes.
    MeSH term(s) Cell Transformation, Neoplastic/genetics ; Clonal Evolution ; Clone Cells/metabolism ; Genetic Heterogeneity ; Genetic Predisposition to Disease/genetics ; High-Throughput Nucleotide Sequencing ; Humans ; Models, Genetic ; Mutation ; Neoplasms/genetics ; Neoplasms/pathology
    Language English
    Publishing date 2017-02-15
    Publishing country England
    Document type Journal Article ; Review ; Research Support, Non-U.S. Gov't
    ZDB-ID 184237-7
    ISSN 1470-8752 ; 0300-5127
    ISSN (online) 1470-8752
    ISSN 0300-5127
    DOI 10.1042/BST20160229
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

    In stock of ZB MED Cologne/Königswinter

    Zs.A 944: Show issues Location:
    Je nach Verfügbarkeit (siehe Angabe bei Bestand)
    bis Jg. 1994: Bestellungen von Artikeln über das Online-Bestellformular
    Jg. 1995 - 2021: Lesesall (1.OG)
    ab Jg. 2022: Lesesaal (EG)

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

To top