Highly-efficient optical generation of narrowband terahertz radiation enables unexplored technologies and sciences from compact electron acceleration to charge manipulation in solids. ...State-of-the-art conversion efficiencies are currently achieved using difference-frequency generation driven by temporal beating of chirped pulses but remain, however, far lower than desired or predicted. Here we show that high-order spectral phase fundamentally limits the efficiency of narrowband difference-frequency generation using chirped-pulse beating and resolve this limitation by introducing a novel technique based on tuning the relative spectral phase of the pulses. For optical terahertz generation, we demonstrate a 13-fold enhancement in conversion efficiency for 1%-bandwidth, 0.361 THz pulses, yielding a record energy of 0.6 mJ and exceeding previous optically-generated energies by over an order of magnitude. Our results prove the feasibility of millijoule-scale applications like terahertz-based electron accelerators and light sources and solve the long-standing problem of temporal irregularities in the pulse trains generated by interfering chirped pulses.
Laser-plasma acceleration promises compact sources of high-brightness relativistic electron beams. However, the limited stability often associated with laser-plasma acceleration has previously ...prevented a detailed mapping of the drive laser and electron performance and represents a major obstacle towards advancing laser-plasma acceleration for applications. Here, we correlate drive laser and electron-beam parameters with high statistics to identify and quantify sources of electron energy drift and jitter. Based on our findings, we provide a parametrization to predict the electron energy drift with subpercent accuracy for many hours from measured laser parameters, which opens a path for performance improvements by active stabilization. Our results are enabled by the first stable 24-h operation of a laser-plasma accelerator and the statistics from 100 000 consecutive electron beams, which, by itself, marks an important milestone.
High-repetition-rate high-power laser systems induce a high average power heat deposition into the gold-coated diffraction gratings. To study the effects of the thermal expansion of in-vacuum Pyrex ...gratings on the laser properties, we scan the pulse energy and repetition rate of a 200 TW laser system while monitoring the laser wavefront. Through the measured changes in laser divergence and focusability, we define an average power limit below which the in-vacuum compressor can be used with no degradation of the laser focus quality.
By using an ensemble-docking strategy, we undertook a large-scale virtual screening campaign in order to identify new putative hits against the MET kinase target. Following a large molecular dynamics ...sampling of its conformational space, a set of 45 conformers of the kinase was retained as docking targets to take into account the flexibility of the binding site moieties. Our screening funnel started from about 80,000 chemical compounds to be tested in silico for their potential affinities towards the kinase binding site. The top 100 molecules selected-thanks to the molecular docking results-were further analyzed for their interactions, and 25 of the most promising ligands were tested for their ability to inhibit MET activity in cells. F0514-4011 compound was the most efficient and impaired this scattering response to HGF (Hepatocyte Growth Factor) with an IC 50 of 7.2 μ M. Interestingly, careful docking analysis of this molecule with MET suggests a possible conformation halfway between classical type-I and type-II MET inhibitors, with an additional region of interaction. This compound could therefore be an innovative seed to be repositioned from its initial antiviral purpose towards the field of MET inhibitors. Altogether, these results validate our ensemble docking strategy as a cost-effective functional method for drug development.
We report on the generation and delivery of 10.2 PW peak power laser pulses, using the High Power Laser System at the Extreme Laser Infrastructure – Nuclear Physics facility. In this work we ...demonstrate for the first time, to the best of our knowledge, the compression and propagation of full energy, full aperture, laser pulses that reach a power level of more than 10 PW.
The Food and Drug Administration (FDA) in the United States and the European Medicines Agency (EMA) have recognized social media as a new data source to strengthen their activities regarding drug ...safety.
Our objective in the ADR-PRISM project was to provide text mining and visualization tools to explore a corpus of posts extracted from social media. We evaluated this approach on a corpus of 21 million posts from five patient forums, and conducted a qualitative analysis of the data available on methylphenidate in this corpus.
We applied text mining methods based on named entity recognition and relation extraction in the corpus, followed by signal detection using proportional reporting ratio (PRR). We also used topic modeling based on the Correlated Topic Model to obtain the list of the matics in the corpus and classify the messages based on their topics.
We automatically identified 3443 posts about methylphenidate published between 2007 and 2016, among which 61 adverse drug reactions (ADR) were automatically detected. Two pharmacovigilance experts evaluated manually the quality of automatic identification, and a f-measure of 0.57 was reached. Patient's reports were mainly neuro-psychiatric effects. Applying PRR, 67% of the ADRs were signals, including most of the neuro-psychiatric symptoms but also palpitations. Topic modeling showed that the most represented topics were related to
, but also
. Cases of misuse were also identified in this corpus, including recreational use and abuse.
Named entity recognition combined with signal detection and topic modeling have demonstrated their complementarity in mining social media data. An in-depth analysis focused on methylphenidate showed that this approach was able to detect potential signals and to provide better understanding of patients' behaviors regarding drugs, including misuse.
The eukaryotic translation initiation factor 4E (eIF4E) controls gene expression through its effects on mRNA export and cap‐dependent translation, both of which contribute to its oncogenic potential. ...In contrast to its translation function, the mRNA export function of eIF4E is poorly understood. Using an RNP isolation/mass spectrometry approach, we identified candidate cofactors of eIF4E mRNA export including LRPPRC. This protein associates with mRNAs containing the eIF4E‐sensitivity element (4E‐SE), and its overexpression alters the nuclear export of several eIF4E‐sensitive mRNAs. LRPPRC‐mediated alteration of eIF4E's mRNA export function requires the integrity of its eIF4E‐binding site and it coincides with the subcellular re‐distribution of eIF4E. The eIF4E export RNP is distinct in composition from the bulk mRNA export pathway, in that eIF4E‐ and eIF4E‐sensitive mRNAs do not associate with general mRNA export factors such as TAP/NXF1 or REF/Aly. Our data indicate that mRNA export pathways have evolved for specific mRNAs enabling the differential regulation of biochemical pathways by modulating the expression of groups of genes at the level of their export.
The prevalence of invasive fungal infections worldwide has increased in the last decades. The development of specific drugs targeting pathogenic fungi without producing collateral damage to mammalian ...cells is a daunting pharmacological challenge. Indeed, many of the toxicities and drug interactions observed with contemporary antifungal therapies can be attributed to "nonselective" interactions with enzymes or cell membrane systems found in mammalian host cells. A computer-aided screening strategy against the TRR1 protein of Paracoccidioides lutzii is presented here. Initially, a bank of commercially available compounds from Life Chemicals provider was docked to model by virtual screening simulations. The small molecules that interact with the model were ranked and, among the best hits, twelve compounds out of 3,000 commercially-available candidates were selected. These molecules were synthesized for validation and in vitro antifungal activity assays for Paracoccidioides lutzii and P. brasiliensis were performed. From 12 molecules tested, 3 harbor inhibitory activity in antifungal assays against the two pathogenic fungi. Corroborating these findings, the molecules have inhibitory activity against the purified recombinant enzyme TRR1 in biochemical assays. Therefore, a rational combination of molecular modeling simulations and virtual screening of new drugs has provided a cost-effective solution to an early-stage medicinal challenge. These results provide a promising technique to the development of new and innovative drugs.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Martinique shares with the other Caribbean countries specific public health issues, particularly in the diagnostic and therapeutic management of cancer patients. Mutualization of human and material ...resources by promoting cooperation is the most appropriate response to the challenges of the health systems of the Caribbean territories. Through the French PRPH-3 program, we propose to set up a collaborative digital platform adapted to the specificities of the Caribbean to strengthen professional links and skills in oncofertility and oncosexology and reduce inequalities in access to reproductive and sexual health care for cancer patients.
Within the context of this program, we have developed of an open-source platform based on a Learning Content Management System (LCMS), with an operating system developed by UNFM for low speed internet. LO libraries have been created and interaction between trainers and learners were done in asynchronous mode. This training management platform is based on: a TCC learning system (Training, Coaching, Communities); a web-hosting with pedagogical engineering appropriate to low bandwidth; a reporting system and a responsibility for processing.
We have carried out a flexible, multilingual and accessible digital learning strategy functionality called e-MCPPO according to low-speed internet ecosystem. In close connection with the e-learning strategy we conceived (i) a multidisciplinary team; (ii) an appropriate training program for expert health professionals and (iii) a responsive design.
This low-speed web-based infrastructure allows communities of experts to cooperate in creating, validating, publishing and managing academic learning content. The self-learning modules provide the digital layer for each learner to extend their skills. Learners, as well as trainers, would gradually take ownership of this platform and encourage its promotion. Innovation in this context is both technological (low-speed Internet broadcasting, free interactive software) and organizational (moderating educational resources). This collaborative digital platform is unique in its form and content. This challenge could contribute to the digital transformation of the Caribbean ecosystem for capacity building in this specifics topics.
Coq6 is an enzyme involved in the biosynthesis of coenzyme Q, a polyisoprenylated benzoquinone lipid essential to the function of the mitochondrial respiratory chain. In the yeast Saccharomyces ...cerevisiae, this putative flavin-dependent monooxygenase is proposed to hydroxylate the benzene ring of coenzyme Q (ubiquinone) precursor at position C5. We show here through biochemical studies that Coq6 is a flavoprotein using FAD as a cofactor. Homology models of the Coq6-FAD complex are constructed and studied through molecular dynamics and substrate docking calculations of 3-hexaprenyl-4-hydroxyphenol (4-HP6), a bulky hydrophobic model substrate. We identify a putative access channel for Coq6 in a wild type model and propose in silico mutations positioned at its entrance capable of partially (G248R and L382E single mutations) or completely (a G248R-L382E double-mutation) blocking access to the channel for the substrate. Further in vivo assays support the computational predictions, thus explaining the decreased activities or inactivation of the mutated enzymes. This work provides the first detailed structural information of an important and highly conserved enzyme of ubiquinone biosynthesis.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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