43,865 research outputs found
Antibody Conjugation and Formulation
In an era where ultra-high antibody concentrations, high viscosities, low volumes, auto-injectors, and long storage requirements are already complex problems with the current unconjugated monoclonal antibodies on the market the formulation demands for antibody-drug conjugates (ADCs) are significant. Antibodies have historically been administered at relatively low concentrations through intravenous (IV) infusion due to their large size and the inability to formulate for oral delivery. Due to the high demands associated with IV infusion and the development of novel antibody targets and unique antibody conjugates more accessible routes of administration such as intramuscular (IM), and subcutaneous (SC) are being explored. This review will summarize various site-specific and non-site-specific antibody conjugation techniques in the context of antibody-drug conjugates (ADCs) and the demands of formulation for high concentration clinical implementation
Etyma for 'chicken', 'duck', and 'goose' among language phyla in China and Southeast Asia
This paper considers the history of words for domesticated poultry, including ‘chicken’,
‘goose’, and ‘duck’, in China and mainland Southeast Asia to try to relate associated
domestication events with specific language groups. Linguistic, archaeological and historical
evidence supports Sinitic as one linguistic source, but in other cases, Tai and Austroasiatic
form additional centers of lexical forms which were borrowed by neighboring phyla. It is
hypothesized that these geographic regions of etyma for domesticated birds may represent
instances of bird domestication, or possibly advances in bird husbandry, by speech communities
in the region in the Neolithic Era, followed by spread of both words and cultural practices
Orion Revisited - I. The massive cluster in front of the Orion Nebula Cluster
The aim of this work is to characterize the stellar population between Earth
and the Orion A molecular cloud where the well known star formation benchmark
Orion Nebula Cluster (ONC) is embedded. We use the denser regions the Orion A
cloud to block optical background light, effectively isolating the stellar
population in front of it. We then use a multi-wavelength observational
approach to characterize the cloud's foreground stellar population. We find
that there is a rich stellar population in front of the Orion A cloud, from
B-stars to M-stars, with a distinct 1) spatial distribution, 2) luminosity
function, and 3) velocity dispersion from the reddened population inside the
Orion A cloud. The spatial distribution of this population peaks strongly
around NGC 1980 (iota Ori) and is, in all likelihood, the extended stellar
content of this poorly studied cluster. We infer an age of ~4-5 Myr for NGC
1980 and estimate a cluster population of the order of 2000 stars, which makes
it one of the most massive clusters in the entire Orion complex. What is
currently taken in the literature as the ONC is then a mix of several
intrinsically different populations, namely: 1) the youngest population,
including the Trapezium cluster and ongoing star formation in the dense gas
inside the nebula, 2) the foreground population, dominated by the NGC 1980
cluster, and 3) the poorly constrained population of foreground and background
Galactic field stars. Our results support a scenario where the ONC and L1641N
are not directly associated with NGC 1980, i.e., they are not the same
population emerging from its parental cloud, but are instead distinct
overlapping populations. This result calls for a revision of most of the
observables in the benchmark ONC region (e.g., ages, age spread, cluster size,
mass function, disk frequency, etc.). (abridged)Comment: Version 2 includes comments and clarifications from John Tobin,
Nicola Da Rio, and Lynne Hillenbrand (minor clarifying changes were made to
Figures 1, 8, and 10). A&A accepted (15 pages, 10 figures). Higher resolution
figures available upon reques
On the trace anomaly and the energy-momentum conservation of quantum fields at D=2 in classical curved backgrounds
We study the conformal symmetry and the energy-momentum conservation of
scalar field interacting with a curved background at D=2. We avoid to
incorporate the metric determinant into the measure of the scalar field to
explain the conformal anomaly and the consequent energy-momentum conservation.
Contrarily, we split the scalar field in two other fields, in such a way that
just one of them can be quantized. We show that the same usual geometric
quantities of the anomaly are obtained, which are accompanied by terms
containing the new field of the theory.Comment: 5 pages, no figure
Hipparcos distances of Ophiuchus and Lupus cloud complexes
We combine extinction maps from the Two Micron All Sky Survey (2MASS) with
Hipparcos and Tycho parallaxes to obtain reliable and high-precision estimates
of the distance to the Ophiuchus and Lupus dark complexes. Our analysis, based
on a rigorous maximum-likelihood approach, shows that the rho-Ophiuchi cloud is
located at (119 +/- 6) pc and the Lupus complex is located at (155 +/- 8) pc;
in addition, we are able to put constraints on the thickness of the clouds and
on their orientation on the sky (both these effects are not included in the
error estimate quoted above). For Ophiuchus, we find some evidence that the
streamers are closer to us than the core. The method applied in this paper is
currently limited to nearby molecular clouds, but it will find many natural
applications in the GAIA-era, when it will be possible to pin down the distance
and three-dimensional structure of virtually every molecular cloud in the
Galaxy.Comment: A&A in press - Corrected typo (Lupus distance) in the electronic
abstrac
Fibers in the NGC1333 proto-cluster
Are the initial conditions for clustered star formation the same as for
non-clustered star formation? To investigate the initial gas properties in
young proto-clusters we carried out a comprehensive and high-sensitivity study
of the internal structure, density, temperature, and kinematics of the dense
gas content of the NGC1333 region in Perseus, one of the nearest and best
studied embedded clusters. The analysis of the gas velocities in the
Position-Position-Velocity space reveals an intricate underlying gas
organization both in space and velocity. We identified a total of 14
velocity-coherent, (tran-)sonic structures within NGC1333, with similar
physical and kinematic properties than those quiescent, star-forming (aka
fertile) fibers previously identified in low-mass star-forming clouds. These
fibers are arranged in a complex spatial network, build-up the observed total
column density, and contain the dense cores and protostars in this cloud. Our
results demonstrate that the presence of fibers is not restricted to low-mass
clouds but can be extended to regions of increasing mass and complexity. We
propose that the observational dichotomy between clustered and non-clustered
star-forming regions might be naturally explained by the distinct spatial
density of fertile fibers in these environments.Comment: 25 pages, 17 figures; Accepted for publication in A&
Uncovering the Beast: Discovery of Embedded Massive Stellar Clusters in W49A
We present subarcsecond J, H, and Ks images (FWHM ~ 0.5") of an unbiased 5'x
5' (16pc x 16pc) survey of the densest region of the W49 giant molecular cloud.
The observations reveal 4 massive stellar clusters (with stars as massive as
\~120 Msun), the larger (Cluster 1) about 3 pc East of the well known Welch
ring of ultra-compact Hii regions. Cluster 1 is a) extincted by at least Av >
20 mag of foreground (unrelated and local) extinction, b) has more than 30 mag
of internal inhomogeneous visual extinction implying that it is still deeply
buried in its parental molecular cloud, and c) is powering a 6 pc diameter
giant Hii region seen both at the NIR and radio continuum. We also identify the
exciting sources of several UCHii regions. The census of massive stars in W49A
agrees or is slightly overabundant when compared with the number of Lyman
continuum photons derived from radio observations. We argue that although the
formation of the Welch ring could have been triggered by Cluster 1, the entire
W49A starburst region seems to have been multi-seeded instead of resulting from
a coherent trigger.Comment: ApJ Letters accepted. All figures provided as nice resolution
jpeg/gif files. Get full-res version at http://www.eso.org/~jalves/W49A.pd
Gravitational collapse of the OMC-1 region
We have investigated the global dynamical state of the Integral Shaped
Filament in the Orion A cloud using new NH (1-0) large-scale, IRAM30m
observations. Our analysis of its internal gas dynamics reveals the presence of
accelerated motions towards the Orion Nebula Cluster, showing a characteristic
blue-shifted profile centred at the position of the OMC-1 South region. The
properties of these observed gas motions (profile, extension, and magnitude)
are consistent with the expected accelerations for the gravitational collapse
of the OMC-1 region and explain both the physical and kinematic structure of
this cloud.Comment: 5 pages, 2 figures; Accepted by A&
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