29 research outputs found
Multiple light-induced NO linkage isomers in the dinitrosyl complex [RuCl(NO)₂(PPh₃)₂]BF₄ nravelled by photocrystallographic and IR analysis
Multiple light-induced reversible metastable NO linkage isomers (PLIs) have been detected in the dinitrosyl compound [RuCl(NO)(2)(PPh3)(2)]BF4 by a combination of photocrystallographic and IR analysis. The IR signature of three PLI states has been clearly identified, with estimated populations of 59% (PLI-1), 8% (PLI-2) and 5% (PLI-3) for a total population of the metastable state of 72%. The structural configuration of the major component (PLI-1) has been derived by X-ray photocrystallography. In the ground state, the structure is characterized by a bent and a linear nitrosyl, the bent one being oriented towards the linear equatorial nitrosyl with an Ru-N-O angle of 133.88 (9)degrees. X-ray Fourier difference maps indicate a selectivity of the photo-isomerization process in PLI-1: only the bent NO ligand changes its position, while the linear NO is unaffected. After irradiation at 405 nm, the orientation is changed by rotation towards the Cl ligand opposite the linear NO, with an Ru-N-O angle in this new position of 109 (1)degrees. The photocrystallographic analysis provides evidence that, in the photo-induced metastable state, the bent NO group is attached to the Ru atom through the N atom (Ru-N-O),rather than in an isonitrosyl Ru-O-N binding mode. In the IR spectra, the asymmetric NO vibrational band shifts by -33 cm(-1) to a lower value, whereas the symmetric band splits and shifts by 5 cm(-1) to a higher value and by -8 cm(-1) to a lower value. The down shift is a clear indication of the structural change, and the small upward shift in response to the new electronic configuration of the metastable structure. Variable-temperature IR kinetic measurements in the range 80-114 K show that the decay of the PLI-1 state follows an Arrhenius behaviour with an activation energy of 0.22 eV
Antiretroviral Drug Resistance in HIV-1–Infected Patients Experiencing Persistent Low-Level Viremia During First-Line Therapy
Population sequencing was performed for persons identified with persistent low-level viremia in 2 clinical trials. Persistent low-level viremia (defined as plasma HIV-1 RNA level >50 and <1000 copies/mL in at least 2 determinations over a 24-week period, after at least 24 weeks of antiretroviral therapy) was observed in 65 (5.6%) of 1158 patients at risk. New resistance mutations were detected during persistent low-level viremia in 37% of the 54 evaluable cases. The most common mutations were M184I/V (14 cases), K103N (9), and M230L (3). Detection of new mutations was associated with higher HIV-1 RNA levels during persistent low-level viremia
Efficacy of a nucleoside-sparing regimen of darunavir/ritonavir plus raltegravir in treatment-naive HIV-1-infected patients (ACTG A5262)
To explore darunavir/ritonavir (DRV/r) plus raltegravir (RAL) combination therapy in antiretroviral-naive patients
A quality control of proteomic experiments based on multiple isotopologous internal standards
The harmonization of proteomics experiments facilitates the exchange and comparison of results. The definition of standards and metrics ensures reliable and consistent data quality. An internal quality control procedure was developed to assess the different steps of a proteomic analysis workflow and perform a system suitability test. The method relies on a straightforward protocol using a simple mixture of exogenous proteins, and the sequential addition of two sets of isotopically labeled peptides added to reference samples. This internal quality control procedure was applied to plasma samples to demonstrate its easy implementation, which makes it generic for most proteomics applications
Electromagnetic transducer for harvesting vibratory energy
An electromagnetic transducer for harvesting vibratory energy is provided. In particular, an electromagnetic transducer comprising a support, a central mass, and at least one spring linking the central mass to the support, the spring allowing the displacement of the central mass with respect to the support on a first axis. A set of electromagnetic transducers is also provided
Electromagnetic transducer for harvesting vibratory energy
An electromagnetic transducer for harvesting vibratory energy is provided. In particular, an electromagnetic transducer comprising a support, a central mass, and at least one spring linking the central mass to the support, the spring allowing the displacement of the central mass with respect to the support on a first axis. A set of electromagnetic transducers is also provided
A Simple Protocol To Routinely Assess the Uniformity of Proteomics Analyses
Mass-spectrometry-based
proteomic approaches are increasingly applied
to biological and clinical studies. Initially used by specialized
laboratories, the technology has matured and gained acceptance by
the community, using various analytical processes and platforms. To
facilitate data comparison and integration across laboratories, there
is a need to harmonize analytical processes to ensure the generation
of reliable proteomic data sets. This is especially critical in the
context of large initiatives, such as the <i>Human Proteome Project</i> promoted by the Human Proteome Organization (HUPO). Quality control
is a first step toward the harmonization of proteomics data sets.
We have developed a procedure to routinely assess the uniformity of
proteomics analyses. It relies on a simple protocol based on three
proteins and two sets of isotopically labeled peptides, one being
added prior to tryptic digestion and the second one prior to liquid
chromatography–mass spectrometry (LC–MS) analysis. The
proposed method evaluates in a single step both the sample preparation,
by measuring the relative amounts of endogenous peptides and their
isotopically labeled counterparts, and the LC–MS platform performance,
by monitoring the main LC–MS attributes for reference peptides.
The procedure is simple and easy to implement into routine workflows
typically employed by the proteomics community
A new approach to design electromagnetic transducers for wideband electrically-tuned vibration energy harvesting
International audienceThis paper focuses on the opportunities offered by electrical tuning towiden the bandwidth of Vibration Energy Harvesters (VEH) based onelectromagnetic conversion. The paper shows that some electromagnetictransducer topologies are more likely than others to take advantage ofthe wide bandwidth performance offered by electrical tuning. Using ageneral model including both a resonant electromagnetic VEH and aresistive-capacitive interface with electrical tuning, we highlight theparameters of interest influencing the bandwidth of the system. Basedon these results, we develop an efficient optimization approach suitablefor any electromagnetic transducer topology. The full optimization ofdifferent transducer topologies shows that the one that is based onvariable reluctance is the best in terms of bandwidth-relatedperformances