Versatile Graphene-Based Platform for Robust Nanobiohybrid Interfaces

Technologically useful and robust graphene-based interfaces for devices require the introduction of highly selective, stable, and covalently bonded functionalities on the graphene surface, whilst essentially retaining the electronic properties of the pristine layer. This work demonstrates that highly controlled, ultrahigh vacuum covalent chemical functionalization of graphene sheets with a thiol-terminated molecule provides a robust and tunable platform for the development of hybrid nanostructures in different environments. We employ this facile strategy to covalently couple two representative systems of broad interest: metal nanoparticles, via S-metal bonds, and thiol-modified DNA aptamers, via disulfide bridges. Both systems, which have been characterized by a multi-technique approach, remain firmly anchored to the graphene surface even after several washing cycles. Atomic force microscopy images demonstrate that the conjugated aptamer retains the functionality required to recognize a target protein. This methodology opens a new route to the integration of high-quality graphene layers into diverse technological platforms, including plasmonics, optoelectronics, or biosensing. With respect to the latter, the viability of a thiol-functionalized chemical vapor deposition graphene-based solution-gated field-effect transistor array was assessed

Benchmarks for Parity Games (extended version)

We propose a benchmark suite for parity games that includes all benchmarks that have been used in the literature, and make it available online. We give an overview of the parity games, including a description of how they have been generated. We also describe structural properties of parity games, and using these properties we show that our benchmarks are representative. With this work we provide a starting point for further experimentation with parity games.Comment: The corresponding tool and benchmarks are available from https://github.com/jkeiren/paritygame-generator. This is an extended version of the paper that has been accepted for FSEN 201

Analysis of the olive fruit fly Bactrocera oleae transcriptome and phylogenetic classification of the major detoxification gene families

he olive fruit fly Bactrocera oleae has a unique ability to cope with olive flesh, and is the most destructive pest of olives worldwide. Its control has been largely based on the use of chemical insecticides, however, the selection of insecticide resistance against several insecticides has evolved. The study of detoxification mechanisms, which allow the olive fruit fly to defend against insecticides, and/or phytotoxins possibly present in the mesocarp, has been hampered by the lack of genomic information in this species. In the NCBI database less than 1,000 nucleotide sequences have been deposited, with less than 10 detoxification gene homologues in total. We used 454 pyrosequencing to produce, for the first time, a large transcriptome dataset for B. oleae. A total of 482,790 reads were assembled into 14,204 contigs. More than 60% of those contigs (8,630) were larger than 500 base pairs, and almost half of them matched with genes of the order of the Diptera. Analysis of the Gene Ontology (GO) distribution of unique contigs, suggests that, compared to other insects, the assembly is broadly representative for the B. oleae transcriptome. Furthermore, the transcriptome was found to contain 55 P450, 43 GST-, 15 CCE- and 18 ABC transporter-genes. Several of those detoxification genes, may putatively be involved in the ability of the olive fruit fly to deal with xenobiotics, such as plant phytotoxins and insecticides. In summary, our study has generated new data and genomic resources, which will substantially facilitate molecular studies in B. oleae, including elucidation of detoxification mechanisms of xenobiotic, as well as other important aspects of olive fruit fly biology

Effect of hypercaloric and isocaloric diets different in fatty acid content on the endo cannabinoid system in pregnant dams and their offspring.

Lipid molecules are the building blocks of all cell membranes and provide essential secondary metabolites. The central nervous system is enriched in polyunsaturated fatty acids (PUFAs): arachidonic acid (AA) and docosahexaenoic acid (DHA). During brain development, PUFAs play a critical role in determining neuronal structure, particularly axonal outgrowth. In mammals, AA and DHA cannot be synthesized de novo and must be obtained largely from dietary sources. Moreover, during pregnancy and lactation, fetuses and infants rely on PUFAs from their mothers through the placenta and breast milk, respectively. Thus, the maternal diet needs to contain an appropriate omega-3/omega-6 PUFAs ratio to help child development. Based on these premises, we investigated the consequences of maternal malnutrition, defined as a shifted dietary ratio of omega-3 or omega-6 PUFAs on the brain of the offspring. In particular, we modeled human relevance by manipulating both the content and time of daily diets, with a keen focus on endocannabinoid (eCB) system given the critical roles of this AA-derived neuromodulator system during pre- and postnatal brain development. In the first approach of this project we fed female mice with hypercaloric diets, rich in omega-3 or in omega-6 PUFA, for two (short-term diet) or nine weeks (long-term diet) before mating and during gestation. We found that, levels of endocannabinoids (AEA, 2-AG) and AEA-like mediators (PEA, OEA) did not change with short-term diet in pregnant dams. Moreover, only omega-3 diet induced a significant increase of 2-AG levels, after long-term protocol. In embryos, we found that the short-term exposure of two weeks of omega-3 and omega-6 diet feeding is already sufficient to allow alteration of endocannabinoid system, especially FAAH and CB1R. In fact, in female embryos, we found down-regulation of CB1R and increase of FAAH after treatment with both diets. Interestingly, both enzyme and receptor levels are normalized after high-fat diet administration for a long period, where AEA levels were found decreased. By contrast, in males the alterations found in CB1R after the shorter protocol persist also after the prolongation of the treatment. In line with this, these data suggest a relationship among AEA, CB1R and FAAH, and an important link between PUFAs and endocannabinoid system. The second approach of this project was based on the administration of isocaloric diets, different in omega-3 levels but not in omega-6 PUFAs throughout gestation and until adulthood. We discovered that during gestation, not only the increase but also the decrease of omega-3 levels markedly affected the eCB system in the hippocampus of embryos. Furthermore, our in vivo results strongly suggest that omega-3 diets enriched and deficient affect the principal presynaptic marker in embryonic hippocampus but not in adult, where maternal malnutrition leads to long-term behavioral alterations in adult rats characterized by the presence of recognition memory deficits. As a whole, the second approach of this study supports our hypothesis about a relationship between PUFAs and the endocannabinoid system and provides further evidence on the importance of omega-3 PUFA on hippocampal development and functioning. All together, our results suggest that changes in dietary omega-3/omega-6 PUFAs ratio during gestation affect the endocannabinoid system in the brain of the offspring and the major effects of diets are present at the beginning of the treatment (i.e during gestation). Moreover, these data suggest that not only lipids but also fat can have a role in these changes

Effect of hypercaloric and isocaloric diets different in fatty acid content on the endo cannabinoid system in pregnant dams and their offspring.

Lipid molecules are the building blocks of all cell membranes and provide essential secondary metabolites. The central nervous system is enriched in polyunsaturated fatty acids (PUFAs): arachidonic acid (AA) and docosahexaenoic acid (DHA). During brain development, PUFAs play a critical role in determining neuronal structure, particularly axonal outgrowth. In mammals, AA and DHA cannot be synthesized de novo and must be obtained largely from dietary sources. Moreover, during pregnancy and lactation, fetuses and infants rely on PUFAs from their mothers through the placenta and breast milk, respectively. Thus, the maternal diet needs to contain an appropriate omega-3/omega-6 PUFAs ratio to help child development. Based on these premises, we investigated the consequences of maternal malnutrition, defined as a shifted dietary ratio of omega-3 or omega-6 PUFAs on the brain of the offspring. In particular, we modeled human relevance by manipulating both the content and time of daily diets, with a keen focus on endocannabinoid (eCB) system given the critical roles of this AA-derived neuromodulator system during pre- and postnatal brain development. In the first approach of this project we fed female mice with hypercaloric diets, rich in omega-3 or in omega-6 PUFA, for two (short-term diet) or nine weeks (long-term diet) before mating and during gestation. We found that, levels of endocannabinoids (AEA, 2-AG) and AEA-like mediators (PEA, OEA) did not change with short-term diet in pregnant dams. Moreover, only omega-3 diet induced a significant increase of 2-AG levels, after long-term protocol. In embryos, we found that the short-term exposure of two weeks of omega-3 and omega-6 diet feeding is already sufficient to allow alteration of endocannabinoid system, especially FAAH and CB1R. In fact, in female embryos, we found down-regulation of CB1R and increase of FAAH after treatment with both diets. Interestingly, both enzyme and receptor levels are normalized after high-fat diet administration for a long period, where AEA levels were found decreased. By contrast, in males the alterations found in CB1R after the shorter protocol persist also after the prolongation of the treatment. In line with this, these data suggest a relationship among AEA, CB1R and FAAH, and an important link between PUFAs and endocannabinoid system. The second approach of this project was based on the administration of isocaloric diets, different in omega-3 levels but not in omega-6 PUFAs throughout gestation and until adulthood. We discovered that during gestation, not only the increase but also the decrease of omega-3 levels markedly affected the eCB system in the hippocampus of embryos. Furthermore, our in vivo results strongly suggest that omega-3 diets enriched and deficient affect the principal presynaptic marker in embryonic hippocampus but not in adult, where maternal malnutrition leads to long-term behavioral alterations in adult rats characterized by the presence of recognition memory deficits. As a whole, the second approach of this study supports our hypothesis about a relationship between PUFAs and the endocannabinoid system and provides further evidence on the importance of omega-3 PUFA on hippocampal development and functioning. All together, our results suggest that changes in dietary omega-3/omega-6 PUFAs ratio during gestation affect the endocannabinoid system in the brain of the offspring and the major effects of diets are present at the beginning of the treatment (i.e during gestation). Moreover, these data suggest that not only lipids but also fat can have a role in these changes

Biological evaluation and molecular modelling of didanosine derivatives

Five carbonate derivatives of 50-O-20,30-dideoxyinosine (DDI, 1) have been synthesized by combination with aliphatic alcohols, with their in vitro anti-HIV activity and cytotoxicity being evaluated afterward in human peripheral blood mononuclear cells (PBMCs). One particular compound, namely DDI-Penta, exhibited an outstanding performance because it was found to have both a higher inhibitory potency and a lower cytotoxicity than the lead compound, resulting in a 100 enhancement in its selectivity index. In order to further study this phenomenon, the ability of these derivatives to bind to the cytoplasmatic nucleotidase (ncN-II) was studied by in silico methods. Also, the higher calculated lipophilicity of the synthesized compounds was proposed to improve their permeability through the cell membrane since said lipophilicity would allow a higher concentration of the corresponding prodrug inside the infected cell. Overall, a combination of an optimal lipophilicity and the ability of DDI-Penta to bind to ncN-II is suggested due to the higher potency and lower cytotoxicity observed for this compound. Based on the reported findings, we believe that the combination of certain aliphatic alcohols and DDI through a carbonate linkage could significantly increase the performance of this class of therapeutic compounds; therefore, it merits further evaluations.Fil: Ravetti, Soledad. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Farmacia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: de Candia, Cristian Ariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas en Retrovirus y Sida. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas en Retrovirus y Sida; ArgentinaFil: Gualdesi, María Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Farmacia; ArgentinaFil: Pampuro, Sandra Esther. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas en Retrovirus y Sida. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas en Retrovirus y Sida; ArgentinaFil: Turk, Gabriela Julia Ana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas en Retrovirus y Sida. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas en Retrovirus y Sida; ArgentinaFil: Quevedo, Mario Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Farmacia; ArgentinaFil: Briñon, Margarita Cristina. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Farmacia; Argentin

On Constant-Round Concurrent Zero-Knowledge from a Knowledge Assumption

In this work, we consider the long-standing open question of constructing constant-round concurrent zero-knowledge protocols in the plain model. Resolving this question is known to require non-black-box techniques. We consider non-black-box techniques for zero-knowledge based on knowledge assumptions, a line of thinking initiated by the work of Hada and Tanaka (CRYPTO 1998). Prior to our work, it was not known whether knowledge assumptions could be used for achieving security in the concurrent setting, due to a number of significant limitations that we discuss here. Nevertheless, we obtain the following results: 1. We obtain the first constant round concurrent zero-knowledge argument for \textbf{NP} in the plain model based on a new variant of knowledge of exponent assumption. Furthermore, our construction avoids the inefficiency inherent in previous non-black-box techniques such that those of Barak (FOCS 2001); we obtain our result through an efficient protocol compiler. 2. Unlike Hada and Tanaka, we do not require a knowledge assumption to argue the soundness of our protocol. Instead, we use a discrete log like assumption, which we call Diffie-Hellman Logarithm Assumption, to prove the soundness of our protocol. 3. We give evidence that our new variant of knowledge of exponent assumption is in fact plausible. In particular, we show that our assumption holds in the generic group model. 4. Knowledge assumptions are especially delicate assumptions whose plausibility may be hard to gauge. We give a novel framework to express knowledge assumptions in a more flexible way, which may allow for formulation of plausible assumptions and exploration of their impact and application in cryptography.Comment: 30 pages, 3 figure

The multikinase inhibitor RXDX-105 is effective against neuroblastoma in vitro and in vivo.

Neuroblastoma is the most common extracranial solid tumor of childhood and accounts for 15% of all pediatric cancer-related deaths. New therapies are needed to improve outcomes for children with high-risk and relapsed tumors. Inhibitors of the RET kinase and the RAS-MAPK pathway have previously been shown to be effective against neuroblastoma, suggesting that combined inhibition may have increased efficacy. RXDX-105 is a small molecule inhibitor of multiple kinases, including the RET and BRAF kinases. We found that treatment of neuroblastoma cells with RXDX-105 resulted in a significant decrease in cell viability and proliferation in vitro and in tumor growth and tumor vascularity in vivo. Treatment with RXDX-105 inhibited RET phosphorylation and phosphorylation of the MEK and ERK kinases in neuroblastoma cells and xenograft tumors, and RXDX-105 treatment induced both apoptosis and cell cycle arrest. RXDX-105 also showed enhanced efficacy in combination with 13-cis-retinoic acid, which is currently a component of maintenance therapy for children with high-risk neuroblastoma. Our results demonstrate that RXDX-105 shows promise as a novel therapeutic agent for children with high-risk and relapsed neuroblastoma