59 research outputs found
Synthesis, metal complexation and biological evaluation of a novel semi-rigid bifunctional chelating agent for 99mTc labelling
A novel bifunctional chelating agent bearing an aromatic ring has been synthesised and characterised. This ligand formed well-defined oxorhenium complexes. The analogous 99mTcO-complex was obtained in an excellent yield with high radiochemical purity (>95%). The biodistribution of the 99mTo-complex after intravenous injection studied in normal rats showed that the activity was excreted mainly via renal-urinary pathway indicating its use for labelling peptides with 99mTc
First examples of neutral rhenium(V) complexes with a novel semi-rigid ligand containing a P,N,N,S donor atom set: Synthesis, characterisation and crystal structure
A new PN2S ligand, N-[2-(diphenylphosphino)phenyl]-2-[(S-trityl)acetylamino]ethanamide [Ph-P(Ph2)N2S(Trt)], was synthesised and reacted with ReV precursors. The reaction of both tritylated and detritylated ligands with ReOCl3(PPh3)2 gave the same expected neutral complex [ReO{Ph-P(Ph2)N2S}] (4) in good yield. An unexpected neutral and diamagnetic species, [ReN{Ph-P(Ph2)N2S(Trt)}] (5), has been isolated during the complexation of the tritylated ligand with ReNCl2(PPh3)2. The complexes, characterized by classical spectroscopic methods and X-ray analysis for 4, are the first examples of neutral semi-rigid-PN2S rhenium(V) complexes
Sodium [2-(mercaptomethylcarbonylamino)-N-(2-mercaptophenyl)ethanamide(4-)-[kappa]4S,N,N',S']oxorhenate(V) monohydrate
In the complex anion of the title compound, Na[Re(C10H8N2O2S2)O]·H2O, the Re atom adopts a square-pyramidal coordination, in which the Re=O bond is apical and the S,N,N,S-tetradentate ligand spans the four basal sites. The Na+ counter-ion is octahedrally surrounded by one S and five O atoms
Tetraphenylphosphonium [N-(2-aminophenyl)-2-(mercaptomethylcarbonylamino)ethanamido(4-)-[kappa]4S,N,N',N'']oxorhenate(V)
The title compound, (C24H20P)[Re(C10H9N3O2S)O], contains well separated square-pyramidal [OReL]- complex anions (L is the deprotonated N-(2-aminophenyl)-2-(mercaptomethylcarbonylamino)ethanamide ligand) and tetrahedral [(C6H5)4P]+ cations. In the anion, the Re=O bond is oriented along the apical direction and the four basal sites are occupied by one S- and three N-atom donors of the tetradentate L4- ligand
Zebra : Building Efficient Network Message Parsers for Embedded Systems
4 pagesInternational audienceSupporting standard text-based protocols in embedded systems is challenging because of the often limited computational resources that embedded systems provide. To overcome this issue, a promising approach is to build parsers directly in hardware. Unfortunately, developing such parsers is a daunting task for most developers as it is at the crossroads of several areas of expertise, such as low-level network programming, or hardware design. In this paper, we propose Zebra, a generative approach to drastically ease the development of hardware parsers and their use in network applications. To validate our approach, we have used Zebra to generate hardware parsers for widely used protocols, namely HTTP, SMTP, SIP, and RTSP. Our experiments show that Zebra-based parsers are up to 11 times faster than software-based parsers
Synthesis and structural characterization of new oxorhenium and oxotechnetium complexes with XN2S-tetradentate semi-rigid ligands(X = O, S, N)
Twelve novel oxo-technetium and oxo-rhenium complexes based on N2S2-, N2SO- or N3S-tetradentate semi-rigid
ligands have been synthesised and studied herein. By reacting the ligands with a slight excess of suitable [MO]3+
precursor (ReOCl3(PPh3)2 or [NBu4][99gTcOCl4]), the monoanionic complexes of general formula [MO(Ph–XN2S)]−
could be easily produced in high yield. The complexes have been characterized by means of IR, electrospray mass
spectrometry, elemental analysis, NMR and conductimetry. The crystal structures of [PPh4][ReO(Ph–ON2S)] 1b and
[NBu4][99gTcO(Ph–ON2S)] 1c have been established. The [MO]3+ moiety was coordinated via the two deprotonated
amide nitrogens, the oxygen and the terminal sulfur atoms in 1b and 1c. In both compounds, the ON2S coordination
set is in the equatorial plane, and the complexes adopted a distorted square-pyramidal geometry with an axial
oxo-group. The chemical and structural identity of the different prototypic complexes (rhenium, 99gTc complexes and
their corresponding 99mTc radiocomplexes) have been also established by a comparative HPLC study
Modulation of spontaneous locomotor and respiratory drives to hindlimb motoneurons temporally related to sympathetic drives as revealed by Mayer waves
In this study we investigated how the networks mediating respiratory and locomotor drives to lumbar motoneurons interact and how this interaction is modulated in relation to periodic variations in blood pressure (Mayer waves). Seven decerebrate cats, under neuromuscular blockade, were used to study central respiratory drive potentials (CRDPs, usually enhanced by added CO(2)) and spontaneously occurring locomotor drive potentials (LDPs) in hindlimb motoneurons, together with hindlimb and phrenic nerve discharges. In four of the cats both drives and their voltage-dependent amplification were absent or modest, but in the other three, one or other of these drives was common and the voltage-dependent amplification was frequently strong. Moreover, in these three cats the blood pressure showed marked periodic variation (Mayer waves), with a slow rate (periods 9–104 s, mean 39 ± 17 SD). Profound modulation, synchronized with the Mayer waves was seen in the occurrence and/or in the amplification of the CRDPs or LDPs. In one animal, where CRDPs were present in most cells and the amplification was strong, the CRDP consistently triggered sustained plateaux at one phase of the Mayer wave cycle. In the other two animals, LDPs were common, and the occurrence of the locomotor drive was gated by the Mayer wave cycle, sometimes in alternation with the respiratory drive. Other interactions between the two drives involved respiration providing leading events, including co-activation of flexors and extensors during post-inspiration or a locomotor drive gated or sometimes entrained by respiration. We conclude that the respiratory drive in hindlimb motoneurons is transmitted via elements of the locomotor central pattern generator. The rapid modulation related to Mayer waves suggests the existence of a more direct and specific descending modulatory control than has previously been demonstrated
Pharmacokinetic aspects of retinal drug delivery
Drug delivery to the posterior eye segment is an important challenge in ophthalmology, because many diseases affect the retina and choroid leading to impaired vision or blindness. Currently, intravitreal injections are the method of choice to administer drugs to the retina, but this approach is applicable only in selected cases (e.g. anti-VEGF antibodies and soluble receptors). There are two basic approaches that can be adopted to improve retinal drug delivery: prolonged and/or retina targeted delivery of intravitreal drugs and use of other routes of drug administration, such as periocular, suprachoroidal, sub-retinal, systemic, or topical. Properties of the administration route, drug and delivery system determine the efficacy and safety of these approaches. Pharmacokinetic and pharmacodynamic factors determine the required dosing rates and doses that are needed for drug action. In addition, tolerability factors limit the use of many materials in ocular drug delivery. This review article provides a critical discussion of retinal drug delivery, particularly from the pharmacokinetic point of view. This article does not include an extensive review of drug delivery technologies, because they have already been reviewed several times recently. Instead, we aim to provide a systematic and quantitative view on the pharmacokinetic factors in drug delivery to the posterior eye segment. This review is based on the literature and unpublished data from the authors' laboratory.Peer reviewe
Event reconstruction for KM3NeT/ORCA using convolutional neural networks
The KM3NeT research infrastructure is currently under construction at two
locations in the Mediterranean Sea. The KM3NeT/ORCA water-Cherenkov neutrino
detector off the French coast will instrument several megatons of seawater with
photosensors. Its main objective is the determination of the neutrino mass
ordering. This work aims at demonstrating the general applicability of deep
convolutional neural networks to neutrino telescopes, using simulated datasets
for the KM3NeT/ORCA detector as an example. To this end, the networks are
employed to achieve reconstruction and classification tasks that constitute an
alternative to the analysis pipeline presented for KM3NeT/ORCA in the KM3NeT
Letter of Intent. They are used to infer event reconstruction estimates for the
energy, the direction, and the interaction point of incident neutrinos. The
spatial distribution of Cherenkov light generated by charged particles induced
in neutrino interactions is classified as shower- or track-like, and the main
background processes associated with the detection of atmospheric neutrinos are
recognized. Performance comparisons to machine-learning classification and
maximum-likelihood reconstruction algorithms previously developed for
KM3NeT/ORCA are provided. It is shown that this application of deep
convolutional neural networks to simulated datasets for a large-volume neutrino
telescope yields competitive reconstruction results and performance
improvements with respect to classical approaches
Event reconstruction for KM3NeT/ORCA using convolutional neural networks
The KM3NeT research infrastructure is currently under construction at two locations in the Mediterranean Sea. The KM3NeT/ORCA water-Cherenkov neutrino de tector off the French coast will instrument several megatons of seawater with photosensors. Its main objective is the determination of the neutrino mass ordering. This work aims at demonstrating the general applicability of deep convolutional neural networks to neutrino telescopes, using simulated datasets for the KM3NeT/ORCA detector as an example. To this end, the networks are employed to achieve reconstruction and classification tasks that constitute an alternative to the analysis pipeline presented for KM3NeT/ORCA in the KM3NeT Letter of Intent. They are used to infer event reconstruction estimates for the energy, the direction, and the interaction point of incident neutrinos. The spatial distribution of Cherenkov light generated by charged particles induced in neutrino interactions is classified as shower-or track-like, and the main background processes associated with the detection of atmospheric neutrinos are
recognized. Performance comparisons to machine-learning classification and maximum-likelihood reconstruction algorithms previously developed for KM3NeT/ORCA are provided. It is shown that this application of deep convolutional neural networks to simulated datasets for a large-volume neutrino telescope yields competitive reconstruction results and performance
improvements with respect to classical approaches
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