2,606 research outputs found
Characterization of VRC01, a potent and broadly neutralizing anti-HIV mAb, produced in transiently and stably transformed tobacco
The proposed clinical trial in Africa of VRC01, a potent broadly neutralizing antibody (bNAb)
capable of neutralizing 91% of known HIV-1 isolates, raises concerns about testing a treatment
which will be too expensive to be accessible by the most important target population, the poor in
under-developed regions such as sub-Saharan Africa. Here, we report the expression of VRC01
in plants as an economic alternative to conventional mammalian-cell-based production
platforms. The heavy and light chain genes of VRC01 were cloned onto a single vector, pTRAk.2,
which was transformed into Nicotiana benthamiana or Nicotiana tabacum using transient and
stable expression production systems respectively. VRC01 has been successfully expressed
transiently in plants with expression level of approximately 80 mg antibody/kg; stable transgenic
lines expressing up to 100 mg antibody/kg were also obtained. Plant-produced VRC01 from
both systems showed a largely homogeneous N-glycosylation profile with a single dominant
glycoform. The binding kinetics to gp120 IIIB (approximately 1 nM), neutralization of HIV-1 BaL or
a panel of 10 VRC01-sensitive HIV-1 Env pseudoviruses of VRC01 produced in transient and
stable plants were also consistent with VRC01 from HEK cells
Finsler pp-waves
In this work we present a Finslerian version of the well-known pp-waves,
which generalizes the very special relativity (VSR) line element. Our Finsler
pp-waves are an exact solution of Finslerian Einstein's equations in vacuum.Comment: 10 pages, minor corrections, references adde
Polystyrene Magadiite Nanocomposites
An organically modified magadiite has been prepared and used to make a mixed intercalated-exfoliated polystyrene nanocomposite by bulk polymerization. This system gives excellent improvement in mechanical properties, but the thermogravimetric analysis curves do not show any change in the onset of the degradation and the degradation pathway is not changed from that for virgin polystyrene, unlike the situation for an aluminosilicate clay, monlmorillonite. By cone calorimetry, the peak heat release rate is not changed, again unlike the results with the aluminosilicate. This suggests that not all clays exhibit the same behavior in nanocomposite formation
Enhancement of steric repulsion with temperature in oriented lipid multilayers
We have studied the temperature dependence of the stacking periodicity, d, of oriented phospholipid multilayers using grazing angle neutron scattering techniques. d is found to increase substantially at higher temperatures, just before the bilayers peel off from the substrate. Although we do not observe thermal unbinding, our results are consistent with the notion that the unbinding transition is driven by steric repulsion arising from thermal fluctuations of the membranes, in contrast to those of a recent study by Vogel et al. [Phys. Rev. Lett. 84, 390 (2000)]
Carbon radio recombination lines from gigahertz to megahertz frequencies towards Orion A
Context. The combined use of carbon radio recombination lines (CRRLs) and the
158 m-[CII] line is a powerful tool for the study of the energetics and
physical conditions (e.g., temperature and density) of photodissociation
regions (PDRs). However, there are few observational studies that exploit this
synergy. Aims. Here we explore the relation between CRRLs and the 158
m-[CII] line in light of new observations and models. Methods. We present
new and existing observations of CRRLs in the frequency range 0.15--230 GHz
with ALMA, VLA, the GBT, Effelsberg 100m, and LOFAR towards Orion~A (M42). We
complement these observations with SOFIA observations of the 158 m-[CII]
line. We studied two PDRs: the foreground atomic gas, known as the Veil, and
the dense PDR between the HII region and the background molecular cloud.
Results. In the Veil we are able to determine the gas temperature and electron
density, which we use to measure the ionization parameter and the photoelectric
heating efficiency. In the dense PDR, we are able to identify a layered PDR
structure at the surface of the molecular cloud to the south of the Trapezium
cluster. There we find that the radio lines trace the colder portion of the
ionized carbon layer, the C/C/CO interface. By modeling the emission of
the ~m-[CII] line and CRRLs as arising from a PDR we derive a thermal
pressure K cm and a radiation field
close to the Trapezium. Conclusions. This work provides
additional observational support for the use of CRRLs and the 158 m-[CII]
line as complementary tools to study dense and diffuse PDRs, and highlights the
usefulness of CRRLs as probes of the C/C/CO interface.Comment: 18 pages, 16 figures, accepted for publication in A&
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