337 research outputs found

    Deep Learning based Differential Classifier of PRIDE and RC5

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    Deep learning-based cryptanalysis is one of the emerging trends in recent times. Differential cryptanalysis is one of the most po- tent approaches to classical cryptanalysis. Researchers are now modeling classical differential cryptanalysis by applying deep learning-based tech- niques. In this paper, we report deep learning-based differential distin- guishers for block cipher PRIDE and RC5, utilizing deep learning models: CNN, LGBM and LSTM. We found distinguishers up to 23 rounds for PRIDE and nine rounds for RC5. To the best of our knowledge this is the first deep learning based differential classifier for cipher PRIDE and RC5

    A Deep Neural Differential Distinguisher for ARX based Block Cipher

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    Over the last few years, deep learning is becoming the most trending topic for the classical cryptanalysis of block ciphers. Differential cryptanalysis is one of the primary and potent attacks on block ciphers. Here we apply deep learning techniques to model differential cryptanaly- sis more easily. In this paper, we report a generic tool called NDDT1, us- ing deep neural classifier that assists to find differential distinguishers for symmetric block ciphers with reduced round. We apply this approach for the differential cryptanalysis of ARX-based encryption schemes HIGHT, LEA, SPARX and SAND. To the best of our knowledge, this is the first deep learning-based distinguisher for the mentioned ciphers. The result shows that our deep learning based distinguishers work with high accuracy for 14-round HIGHT, 13-Round LEA, 11-round SPARX and 14-round SAND128. The relationship between the hamming weight of input difference of a neural distinguisher and the corresponding maxi- mum round number of the cipher has been justified through exhaustive experimentation. The lower bounds of data complexity for differential cryptanalysis have also been improved

    Secondary Structure-Dependent Physicochemical Interaction of Oligonucleotides with Gold Nanorod and Photothermal Effect for Future Applications: A New Insight

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    We investigate the physicochemical interactions of gold nanorod (GNR) with single-stranded, double-stranded, and hairpin DNA structures to improve the biological compatibility as well as the therapeutic potential, including the photothermal effect of the conjugates. Studies have demonstrated that different DNA secondary structures, containing thiol group, have different patterns of physicochemical interaction. Conjugation efficiency of paired oligonucleotides are significantly higher than that of oligonucleotides with naked bases. Furthermore, hairpin-shaped DNA structures are most efficient in terms of conjugation and increased dispersion, with least interference on GNR near-infrared absorbance and photothermal effect. Our conjugation method can successfully exchange the overall coating of the GNR, attaching the maximum number of DNA molecules, thus far reported. Chemical mapping depicted uniform attachment of thiolated DNA molecules without any topological preference on the GNR surface. Hairpin DNA-coated GNR are suitable for intracellular uptake and remain dispersed in the cellular environment. Finally, we conjugated GNR with 5-fluoro-2'-deoxyuridine-containing DNA hairpin and the conjugate demonstrated significant cytotoxic activity against human cervical cancer cell line (KB). Thus, hairpin DNA structures could be utilized for optimal dispersion and photothermal effect of GNR, along with the delivery of cytotoxic nucleotides, developing the concept of multimodality approach

    Generation of specific inhibitors of SUMO-1– and SUMO-2/3–mediated protein-protein interactions using Affimer (Adhiron) technology

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    Because protein-protein interactions underpin most biological processes, developing tools that target them to understand their function or to inform the development of therapeutics is an important task. SUMOylation is the posttranslational covalent attachment of proteins in the SUMO family (SUMO-1, SUMO-2, or SUMO-3), and it regulates numerous cellular pathways. SUMOylated proteins are recognized by proteins with SUMO-interaction motifs (SIMs) that facilitate noncovalent interactions with SUMO. We describe the use of the Affimer system of peptide display for the rapid isolation of synthetic binding proteins that inhibit SUMO-dependent protein-protein interactions mediated by SIMs both in vitro and in cells. Crucially, these synthetic proteins did not prevent SUMO conjugation either in vitro or in cell-based systems, enabling the specific analysis of SUMO-mediated protein-protein interactions. Furthermore, through structural analysis and molecular modeling, we explored the molecular mechanisms that may underlie their specificity in interfering with either SUMO-1–mediated interactions or interactions mediated by either SUMO-2 or SUMO-3. Not only will these reagents enable investigation of the biological roles of SUMOylation, but the Affimer technology used to generate these synthetic binding proteins could also be exploited to design or validate reagents or therapeutics that target other protein-protein interactions

    Adhiron: a stable and versatile peptide display scaffold for molecular recognition applications

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    We have designed a novel non-antibody scaffold protein, termed Adhiron, based on a phytocystatin consensus sequence. The Adhiron scaffold shows high thermal stability (Tm ca. 101°C), and is expressed well in Escherichia coli. We have determined the X-ray crystal structure of the Adhiron scaffold to 1.75 Å resolution revealing a compact cystatin-like fold. We have constructed a phage-display library in this scaffold by insertion of two variable peptide regions. The library is of high quality and complexity comprising 1.3 × 10(10) clones. To demonstrate library efficacy, we screened against the yeast Small Ubiquitin-like Modifier (SUMO). In selected clones, variable region 1 often contained sequences homologous to the known SUMO interactive motif (V/I-X-V/I-V/I). Four Adhirons were further characterised and displayed low nanomolar affinities and high specificity for yeast SUMO with essentially no cross-reactivity to human SUMO protein isoforms. We have identified binders against >100 target molecules to date including as examples, a fibroblast growth factor (FGF1), platelet endothelial cell adhesion molecule (PECAM-1; CD31), the SH2 domain Grb2 and a 12-aa peptide. Adhirons are highly stable and well expressed allowing highly specific binding reagents to be selected for use in molecular recognition applications

    Secondary Structure-Dependent Physicochemical Interaction of Oligonucleotides with Gold Nanorod and Photothermal Effect for Future Applications: A New Insight

    Get PDF
    We investigate the physicochemical interactions of gold nanorod (GNR) with single-stranded, double-stranded, and hairpin DNA structures to improve the biological compatibility as well as the therapeutic potential, including the photothermal effect of the conjugates. Studies have demonstrated that different DNA secondary structures, containing thiol group, have different patterns of physicochemical interaction. Conjugation efficiency of paired oligonucleotides are significantly higher than that of oligonucleotides with naked bases. Furthermore, hairpin-shaped DNA structures are most efficient in terms of conjugation and increased dispersion, with least interference on GNR near-infrared absorbance and photothermal effect. Our conjugation method can successfully exchange the overall coating of the GNR, attaching the maximum number of DNA molecules, thus far reported. Chemical mapping depicted uniform attachment of thiolated DNA molecules without any topological preference on the GNR surface. Hairpin DNA-coated GNR are suitable for intracellular uptake and remain dispersed in the cellular environment. Finally, we conjugated GNR with 5-fluoro-2′-deoxyuridine-containing DNA hairpin and the conjugate demonstrated significant cytotoxic activity against human cervical cancer cell line (KB). Thus, hairpin DNA structures could be utilized for optimal dispersion and photothermal effect of GNR, along with the delivery of cytotoxic nucleotides, developing the concept of multimodality approach

    Organic and elemental carbon variation in PM2.5 over megacity Delhi and Bhubaneswar, a semi-urban coastal site in India

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    This paper presents the effect of meteorology, long-range transport, boundary layer and anthropogenic activities on the chemical composition of aerosol (PM2.5) particularly carbonaceous aerosol (OC, EC TC) in two Indian cities, namely Delhi and Bhubaneswar. The climatological and demographical differences in the two cities have compelled the authors to compare concentrations of atmospheric organic carbon (OC) and elemental carbon (EC) in PM2.5 at Delhi and Bhubaneswar during winter 2013 (Dec 2012 to Feb 2013). Although, Delhi is a densely populated megacity with several anthropogenic activities, Bhubaneswar is a comparatively less dense small coastal city. The percentage contribution of total carbon (TC) to PM2.5 mass was higher as recorded at Bhubaneswar (similar to 30.38 %) as compared to Delhi (similar to 15 %). Average ratios of OCtot/EC, K+/OCtot and K+/EC were recorded as 1.88 +/- A 0.24, 0.006 +/- A 0.004 and 0.018 +/- A 0.013 at Bhubaneswar, respectively, whereas in Delhi, respective average ratios of OCtot/EC, K+/OCtot and K+/EC were recorded as 1.37 +/- A 0.16, 0.230 +/- A 0.066 and 0.321 +/- A 0.122. OCtot/EC, K+/OCtot, K+/EC ratios and eight carbon fraction analysis of PM2.5 mass revealed the dominant contribution of fossil fuel specifically from coal combustion at Bhubaneswar, whereas vehicular exhaust, fossil fuel combustion along with biomass burning and road dust were the main sources of emission at Delhi. Long-range transport and prevailing meteorology had a major impact on the respective pollutants at Bhubaneswar, and OCtot and EC of PM2.5 mass over Delhi were believed to have originated from local sources due to shallow boundary layer, stable meteorology and high anthropogenic activities during the observation period. Besides, secondary organic carbon (OCsec) contributed 15.76 +/- A 8.41 and 14.65 +/- A 7.46 % to OCtot concentration of Bhubaneswar and Delhi, respectively

    Not Available

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    Not AvailableHeavy metal contamination poses a serious threat to both the ecosystem and human and requires expensive cleanup costs. Bioremediation based on microorganisms, plants, or other biological systems offers cost-effective and environment friendly metal clean-up methods. Studies on bacterial diversity in heavy metal contaminated sites have demonstrated a high diversity of microorganisms that are adapted to the new environment. Bacteria that are resistant to and grow on metals play an important role in the biogeochemical cycling of those metal ions. In pursuit to identify bacteria that are tolerant to different heavy metals and can have a potential in bioremediation, surveys, and collection of samples from several presumptive heavy metal-polluted sites of India were carried out. A total of 77 bacterial morphotypes were obtained, and based on minimum inhibitory concentrations (MIC) of different heavy metals, that is Pbþ2, Niþ2, Cdþ2, Crþ3, Hgþ2, Cuþ2, Znþ2, Coþ2, and Asþ2, thirteen potential bacterial isolates were identified possessing very high and multiple heavy metal tolerance like arsenic (50–1100mg kg 1), lead (100–2000mg kg 1), chromium (250–500mg kg 1), cadmium (50–100mg kg 1), and other heavy metals. All potential bacteria were morphologically characterized, identified based on the 16 s rRNA gene sequences, and studied for plant growth promoting attributes. Bacterial strains were found to be phosphate solubilizers, siderophore and ammonia producers, and nitrate reducers. Bacillus cereus MB1, Bacillus amyloliquefaciens RD4, Bacillus megaterium MF7, and E. cloacae MC4 were evaluated for alleviation of As, Cr, Ni, and Pb toxicity, respectively in spinach. The inoculation of plants with respective heavy metal-tolerant bacteria under study gave higher records of all estimated growth parameters, total chlorophyll content and antioxidant enzyme, superoxide dismutase, activity and differential response in proline biosynthesis when compared to respective uninoculated heavy metal controls. Overall selected plant growth-promoting heavy metal-tolerant bacterial inoculations were found to promote growth and reduce the respective heavy metal toxicity in spinach plant. Since heavy metal contamination in agricultural lands is becoming serious environmental concern, the heavy metal-tolerant plant growth-promoting strains reported in this study can offer suitable economical and ecofriendly base for development of the bioremediation strategies.Not Availabl

    Augmentation of metal tolerant bacteria elevate growth and reduce metal toxicity in Spinach.

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    Not AvailableHeavy metal contamination poses a serious threat to both the ecosystem and human and requires expensive cleanup costs. Bioremediation based on microorganisms, plants, or other biological systems offers cost-effective and environment friendly metal clean-up methods. Studies on bacterial diversity in heavy metal contaminated sites have demonstrated a high diversity of microorganisms that are adapted to the new environment. Bacteria that are resistant to and grow on metals play an important role in the biogeochemical cycling of those metal ions. In pursuit to identify bacteria that are tolerant to different heavy metals and can have a potential in bioremediation, surveys, and collection of samples from several presumptive heavy metal-polluted sites of India were carried out. A total of 77 bacterial morphotypes were obtained, and based on minimum inhibitory concentrations (MIC) of different heavy metals, that is Pbþ2, Niþ2, Cdþ2, Crþ3, Hgþ2, Cuþ2, Znþ2, Coþ2, and Asþ2, thirteen potential bacterial isolates were identified possessing very high and multiple heavy metal tolerance like arsenic (50–1100mg kg 1), lead (100–2000mg kg 1), chromium (250–500mg kg 1), cadmium (50–100mg kg 1), and other heavy metals. All potential bacteria were morphologically characterized, identified based on the 16 s rRNA gene sequences, and studied for plant growth promoting attributes. Bacterial strains were found to be phosphate solubilizers, siderophore and ammonia producers, and nitrate reducers. Bacillus cereus MB1, Bacillus amyloliquefaciens RD4, Bacillus megaterium MF7, and E. cloacae MC4 were evaluated for alleviation of As, Cr, Ni, and Pb toxicity, respectively in spinach. The inoculation of plants with respective heavy metal-tolerant bacteria under study gave higher records of all estimated growth parameters, total chlorophyll content and antioxidant enzyme, superoxide dismutase, activity and differential response in proline biosynthesis when compared to respective uninoculated heavy metal controls. Overall selected plant growth-promoting heavy metal-tolerant bacterial inoculations were found to promote growth and reduce the respective heavy metal toxicity in spinach plant. Since heavy metal contamination in agricultural lands is becoming serious environmental concern, the heavy metal-tolerant plant growth-promoting strains reported in this study can offer suitable economical and ecofriendly base for development of the bioremediation strategies.Not Availabl
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