We report the subnanometer cryo-electron microscopy (cryoEM) reconstruction of a marine siphovirus, the Vibrio phage SIO-2. This phage is lytic for related Vibrio species with significant ecological ...importance, including the broadly antagonistic bacterium Vibrio sp. SWAT3. The three-dimensional structure of the 800 Å SIO-2, icosahedrally averaged head of the tailed particle revealed a T = 12 quasi-symmetry not previously described in a bacteriophage. Two morphologically distinct types of auxiliary proteins were also identified; one species bound to the surface of hexamers, and the other bound to pentamers. The secondary structure, evident in the electron density, shows that the major capsid protein has the HK97-like fold. The three-dimensional structure of the procapsid form, also presented here, has no “decoration” proteins and reveals a capsomer organization due to the constraints of the T = 12 symmetry.
► The SIO2 dsDNA bacteriophage displays T = 12 quasi-symmetry ► This places icosahedral symmetry constraints on subunit hexamers ► The restrictions are conspicuous in the procapsid where “hexamers” are skewed ► The balance of energetics required by stages of assembly and symmetry are discussed
High-frequency pCO
2 and ancillary data were recorded for seven years during the first deployment of a CARbon Interface OCean Atmosphere (CARIOCA) sensor in the surface waters of a temperate coastal ...ecosystem, the Bay of Brest, which is impacted by both coastal (via estuaries) and oceanic (North Atlantic via the Iroise Sea) water inputs. The CARIOCA sensor proved to be an excellent tool to constrain the high pCO
2 variability in such dynamic coastal ecosystem. Biological processes (e.g. pelagic photosynthesis/respiration) were the main drivers of the seasonal and diurnal pCO
2 dynamics throughout seven years of observations. Autotrophic processes were responsible for abrupt pCO
2 drawdown of 100 to 200
μatm in spring. During the spring bloom, diurnal variations were driven by diel biological cycle. The average daily drawdown due to autotrophy (observed during highest daily PAR) was equivalent to 10 to 60% of the total pCO
2 drawdown observed every year during the spring season. From late summer to fall, heterotrophic processes increased pCO
2 in the surface water of the Bay back to the pre-bloom level. The average daily increase due to heterotrophy (observed during lowest daily PAR) corresponded to 10 to 70% of the total pCO
2 increase observed every year during the late summer to fall period. Air–sea CO
2 fluxes estimates based on hourly, daily and monthly calculations showed that careful consideration of the diurnal variability was needed to accurately estimate air–sea CO
2 fluxes in the Bay of Brest. Sampling only during daytime or night-time would induce 8 to 36% error on monthly air–sea CO
2 fluxes. This would in turn reverse the direction of the fluxes at annual level for the Bay. The annual emissions of CO
2 from the surface waters of the Bay to the atmosphere showed relatively low inter-annual variations with an average of +
0.7
±
0.4
mol
C
m
−2
yr
−
1
computed for the study period. Further, air–sea CO
2 fluxes computed for the adjacent inner-estuaries and Iroise Sea for an annual cycle were +
17
±
3
mol
C
m
−2
yr
−
1
and −
0.2
±
0.2
mol
C
m
−2
yr
−
1
, respectively. The spatial gradient showed a clear pattern from strong source to sink of CO
2, from the inner-estuaries to the open oceanic waters of the North Atlantic. We suggest that semi-enclosed Bays act as buffers for sea to air emissions of CO
2 from inner estuaries to adjacent costal seas.
► We assessed pCO
2 dynamics from diurnal to inter-annual level in the Bay of Brest. ► Pelagic biological processes controlled pCO
2 dynamics from spring to fall. ► Integrating pCO
2 diurnal variability is imperative for air–sea CO
2 fluxes estimates. ► Bays act as buffers for sea to air CO
2 emissions from estuaries to coastal seas.
Cellular immunotherapy consists in using the cells of the immune system as a therapeutic weapon. In this constantly evolving field, the therapeutic strategies developed at the University Hospital of ...Liege are hematopoietic stem cell transplantation, mesenchymal stromal cells and targeted therapy with CAR-T cells (Chimeric Antigen Receptor T cells). The first two modalities represent a form of non-targeted cell therapy that has been developed over the past decades. While hematopoietic stem cell transplantation is established as the reference treatment for many hematological diseases, mesenchymal stromal cells are still under investigation in various pathologies (notably Crohn's disease, organ transplantation, COVID-19 and pulmonary fibrosis). By contrast, CAR-T cells represent a recently developed and extremely promising targeted immunotherapy. This therapeutic approach has already revolutionized the treatment of B-cell lymphopathies, and has the potential to do the same for many other diseases in the near future.
New pyridinium salts having a 1,3-dioxan ring in their central core are desribed as the first examples of axially chiral ionic liquids. They exhibit both low melting points and liquid crystal ...behaviour.
As the first examples of axially chiral ionic liquids, new pyridinium salts having a 1,3-dioxan ring in their central core were synthesized. Enantioselective dehydrohalogenation using chiral alkoxides provided a simple and practical approach for their synthesis. Some structures exhibit both low melting point and liquid crystalline behaviour.
A decisive step forward: A one‐step fluorination on modified cinchona alkaloids produced a new range of enantiopure fluorinating agents that display high enantioselectivities in electrophilic ...fluorination. The first enantioselective synthesis of N‐protected α‐fluorophenylglycine derivatives was achieved with an enantiomeric excess up to 94 % Eq. (a); R=Et, CN; HMDS=hexamethyldisilazanide.
This study aims at explaining the absence of a threshold for crack propagation in an α/β titanium alloy during cyclic tests performed with constant
K
max and increasing
K
min, if
K
max is higher than ...60–70% of
K
Ic. Tensile, creep as well as fatigue crack growth tests are performed on specimens with various hydrogen content. SIMS analyses of hydrogen content around the tip of a crack developed in the abnormal regime are made. Solute hydrogen is shown to segregate at the crack tip and to enhance room-temperature creep, strain localisation and decohesion along α/β interfaces.
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