33,813 research outputs found
The possible members of the meson nonet
The strong decays of the states are evaluated in the
model with two types of space wave functions. Comparing the model
expectations with the experimental data for the , ,
, and , we suggest that the , , and
can be assigned as the members of the meson nonet, while the
assignment for the is not favored by its width. The
kaon is predicted to have a mass of about 2418 MeV and a width of about 163 MeV
or 225 MeV.Comment: 10 pages, 5 figures, version accepted by Eur. Phys. J.
Phenylboronic acid-diol crosslinked 6-<i>O</i>-vinylazeloyl-d-galactose nanocarriers for insulin delivery
A new block polymer named poly 3-acrylamidophenylboronic acid-b-6-O–vinylazeloyl-d-galactose (p(AAPBA-b-OVZG)) was prepared using 3-acrylamidophenylboronic acid (AAPBA) and 6-O-vinylazeloyl-D-galactose (OVZG) via a two-step procedure involving S-1-dodecyl-S-(α', α'-dimethyl-α″-acetic acid) trithiocarbonate (DDATC) as chain transfer agent, 2,2-azobisisobutyronitrile (AIBN) as initiator and dimethyl formamide (DMF) as solvent. The structures of the polymer were examined by Fourier transform infrared spectroscopy (FT-IR) and 1H NMR and the thermal stability was determined by thermal gravimetric analysis (TG/DTG). Transmission electron microscopy (TEM) and dynamic light scattering (DLS) were utilized to evaluate the morphology and properties of the p(AAPBA-b-OVZG) nanoparticles. The cell toxicity, animal toxicity and therapeutic efficacy were also investigated. The results indicate the p(AAPBA-b-OVZG) was successfully synthesized and had excellent thermal stability. Moreover, the p(AAPBA-b-OVZG) nanoparticles were submicron in size and glucose-sensitive in phosphate-buffered saline (PBS). In addition, insulin as a model drug had a high encapsulation efficiency and loading capacity and the release of insulin was increased at higher glucose levels. Furthermore, the nanoparticles showed a low-toxicity in cell and animal studies and they were effective at decreasing blood glucose levels of mice over 96 h. These p(AAPBA-b-OVZG) nanoparticles show promise for applications in diabetes treatment using insulin or other hypoglycemic proteins
Land Rights Insecurity and Temporary Migration in Rural China
Like most other developing countries, China experiences huge migration outflows from rural areas. Their most striking characteristic is a high geographical and temporal mobility. Rural migrants keep going back and forth between origin villages and destination areas. In this paper, we show that this temporary feature of migration can be linked to land rights insecurity. As village land ownership remains collective and as land use rights can be periodically reallocated, individual out-migration can result in deprivation of those rights. Moreover, the intensity of this insecurity varies according to the village-level management of land and the contractual status of land plots. We use these variations to identify the effect of land rights insecurity on migration behavior. Empirical results based on representative 2002 rural data demonstrate substantial impact.migration, land rights insecurity, China, semiparametric censored regression models
Quantum Spring from the Casimir Effect
The Casimir effect arises not only in the presence of material boundaries but
also in space with nontrivial topology. In this paper, we choose a topology of
the flat -dimensional spacetime, which causes the helix boundary
condition for a Hermitian massless scalar field. Especially, Casimir effect for
a massless scalar field on the helix boundary condition is investigated in two
and three dimensions by using the zeta function techniques. The Casimir force
parallel to the axis of the helix behaves very much like the force on a spring
that obeys the Hooke's law when the ratio of the pitch to the circumference
of the helix is small, but in this case, the force comes from a quantum effect,
so we would like to call it \textit{quantum spring}. When is large, this
force behaves like the Newton's law of universal gravitation in the leading
order. On the other hand, the force perpendicular to the axis decreases
monotonously with the increasing of the ratio . Both forces are attractive
and their behaviors are the same in two and three dimensions.Comment: 6 pages, 7 figures, published in PL
Near-Horizon Virasoro Symmetry and the Entropy of de Sitter Space in Any Dimension
De Sitter spacetime is known to have a cosmological horizon that enjoys
thermodynamic-like properties similar to those of a black hole horizon. In this
note we show that a universal argument can be given for the entropy of de
Sitter spacetime in arbitrary dimensions, by generalizing a recent near horizon
symmetry plus conformal field theory argument of Carlip for black hole entropy.
The implications of this argument are also discussed.Comment: 13 pages, no figure. Add one reference and correct a minor typo in
pp.6, no change was made in tex
Distinct expression and methylation patterns for genes with different fates following a single whole-genome duplication in flowering plants
For most sequenced flowering plants, multiple whole-genome duplications (WGDs) are found. Duplicated genes following WGD often have different fates that can quickly disappear again, be retained for long(er) periods, or subsequently undergo small-scale duplications. However, how different expression, epigenetic regulation, and functional constraints are associated with these different gene fates following a WGD still requires further investigation due to successive WGDs in angiosperms complicating the gene trajectories. In this study, we investigate lotus (Nelumbo nucifera), an angiosperm with a single WGD during the K–pg boundary. Based on improved intraspecific-synteny identification by a chromosome-level assembly, transcriptome, and bisulfite sequencing, we explore not only the fundamental distinctions in genomic features, expression, and methylation patterns of genes with different fates after a WGD but also the factors that shape post-WGD expression divergence and expression bias between duplicates. We found that after a WGD genes that returned to single copies show the highest levels and breadth of expression, gene body methylation, and intron numbers, whereas the long-retained duplicates exhibit the highest degrees of protein–protein interactions and protein lengths and the lowest methylation in gene flanking regions. For those long-retained duplicate pairs, the degree of expression divergence correlates with their sequence divergence, degree in protein–protein interactions, and expression level, whereas their biases in expression level reflecting subgenome dominance are associated with the bias of subgenome fractionation. Overall, our study on the paleopolyploid nature of lotus highlights the impact of different functional constraints on gene fate and duplicate divergence following a single WGD in plant
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