1,597 research outputs found
A Descriptive Model of Robot Team and the Dynamic Evolution of Robot Team Cooperation
At present, the research on robot team cooperation is still in qualitative
analysis phase and lacks the description model that can quantitatively describe
the dynamical evolution of team cooperative relationships with constantly
changeable task demand in Multi-robot field. First this paper whole and static
describes organization model HWROM of robot team, then uses Markov course and
Bayesian theorem for reference, dynamical describes the team cooperative
relationships building. Finally from cooperative entity layer, ability layer
and relative layer we research team formation and cooperative mechanism, and
discuss how to optimize relative action sets during the evolution. The dynamic
evolution model of robot team and cooperative relationships between robot teams
proposed and described in this paper can not only generalize the robot team as
a whole, but also depict the dynamic evolving process quantitatively. Users can
also make the prediction of the cooperative relationship and the action of the
robot team encountering new demands based on this model. Journal web page & a
lot of robotic related papers www.ars-journal.co
Contrastive Analysis of the Raman Spectra of Polychlorinated Benzene: Hexachlorobenzene and Benzene
Detection of persistent pollutants such as polychlorinated benzene in environment in trace amounts is challenging, but important. It is more difficult to distinguish homologues and isomers of organic pollutantd when present in trace amounts because of their similar physical and chemical properties. In this work we simulate the Raman spectra of hexachlorobenzene and benzene, and figure out the vibration mode of each main peak. The effect on the Raman spectrum of changing substituents from H to Cl is analyzed to reveal the relations between the Raman spectra of homologues and isomers of polychlorinated benzene, which should be helpful for distinguishing one kind of polychlorinated benzene from its homologues and isomers by surface enhanced Raman scattering
A meta-analysis: neoadjuvant chemotherapy versus primary surgery in ovarian carcinoma FIGO stageIII and IV
Design of a small reverberation box based on BEM-SEA method
The reverberation chamber which was used to test sound absorption and insulation performance in the reverberation space had the following problems. Firstly, the construction cost of the reverberation chamber was high. Secondly, the test can’t be completed when the size of the specimen was too small. As a result, a small reverberation box with a relatively small size had significant meaning. The previous researchers designed the small reverberation box by using the traditional experience and theory formulas which had a long period and high cost. In order to solve this problem, simulation analysis on sound insulation performance of a compound structure through Statistical Energy Analysis (SEA) was proposed. And then the sound field distribution of the small reverberation box was simulated by Boundary Element Method (BEM). According to the simulation results, the model was optimized repeatedly. And finally a small reverberation box model with sufficient sound insulation performance and uniform sound field was obtained. The actual structure was made based on simulation model, and its sound characteristic was tested. The results showed that the small reverberation box had an excellent performance. BEM-SEA method was feasible to be used to design a small reverberation box
(3R*)-Methyl 3-[(2S*)-4,6-dimethoxy-2-(4-methoxyphenyl)-3-oxo-2,3-dihydro-1-benzofuran-2-yl]-2-methoxycarbonyl-3-phenylpropionate
The title compound, C29H28O9, was isolated from the reaction of 4,6-dimethÂoxy-2-(4-methoxyÂphenÂyl)-3-benzofuran and α-methoxyÂcarbonylÂcinnaminate. The two aromatic rings form a dihedral angle of 22.7 (1)°. One methoxyÂcarbonyl group is disordered between two orientations in a 0.612 (4):0.388 (4) ratio. The crystal structure exhibits no significantly short interÂmolecular contacts
The Study of Dust Formation of Six Tidal Disruption Events
This paper investigates eleven (UV-)optical-infrared (IR) spectral energy
distributions (SEDs) of six tidal disruption events (TDEs), which are
ASASSN-14li, ASASSN-15lh, ASASSN-18ul, ASASSN-18zj, PS18kh, and ZTF18acaqdaa.
We find that all the SEDs show evident IR excesses. We invoke the blackbody
plus dust emission model to fit the SEDs, and find that the model can account
for the SEDs. The derived masses of the dust surrounding ASASSN-14li,
ASASSN-15lh, ASASSN-18ul, ASASSN-18zj, PS18kh, and ZTF18acaqdaa are
respectively ,
,
,
,
, and , if the dust is graphite (silicate). The
temperature of the graphite (silicate) dust of the six TDEs are respectively
\,K, \,K,
\,K, \,K, \,K, and
\,K. By comparing the derived temperatures to the
vaporization temperature of graphite (\,K) and silicate (\,K), we suggest that the IR excesses of PS18kh can be explained by
both the graphite and silicate dust, the rest five TDEs favor the graphite dust
while the silicate dust model cannot be excluded. Moreover, we demonstrate the
lower limits of the radii of the dust shells surrounding the six TDEs are
significantly larger than those of the radii of the photospheres at the first
epochs of SEDs, indicating that the dust might exist before the the TDEs
occurred.Comment: 13 pages, 4 figures, 4 tables, submitted to Ap
Combination Therapy With Fingolimod and Neural Stem Cells Promotes Functional Myelination
Myelination, which occurs predominantly postnatally and continues throughout life, is important for proper neurologic function of the mammalian central nervous system (CNS). We have previously demonstrated that the combination therapy of fingolimod (FTY720) and transplanted neural stem cells (NSCs) had a significantly enhanced therapeutic effect on the chronic stage of experimental autoimmune encephalomyelitis, an animal model of CNS autoimmunity, compared to using either one of them alone. However, reduced disease severity may be secondary to the immunomodulatory effects of FTY720 and NSCs, while whether this therapy directly affects myelinogenesis remains unknown. To investigate this important question, we used three myelination models under minimal or non-inflammatory microenvironments. Our results showed that FTY720 drives NSCs to differentiate into oligodendrocytes and promotes myelination in an ex vivo brain slice culture model, and in the developing CNS of healthy postnatal mice in vivo. Elevated levels of neurotrophic factors, e.g., brain-derived neurotrophic factor and glial cell line-derived neurotrophic factor, were observed in the CNS of the treated infant mice. Further, FTY720 and NSCs efficiently prolonged the survival and improved sensorimotor function of shiverer mice. Together, these data demonstrate a direct effect of FTY720, beyond its known immunomodulatory capacity, in NSC differentiation and myelin development as a novel mechanism underlying its therapeutic effect in demyelinating diseases
Use of a novel valve stent for transcatheter pulmonary valve replacement: An animal study
ObjectiveThe goal of this study was to evaluate valvular functionality after transcatheter pulmonary valve replacement in sheep using a novel pulmonary valve stent.MethodsFresh porcine pericardium cross-linked with 0.6% glutaraldehyde was treated with L-glutamine to eliminate glutaraldehyde toxicity and sutured onto a valve ring before mounting on a nitinol stent to construct the pulmonary valve stent. Percutaneous femoral vein transcatheter pulmonary valve replacement was performed with the newly constructed valve stent. Pulmonary valve stents were implanted in 10 healthy sheep (6 males and 4 females) weighing an average of 25.7 ± 4.1 kg. Color Doppler echocardiography, 64-row computed tomography, and direct catheter examination were used to assess valvular function.ResultsImplantation was successful in 8 sheep. Shortly after surgery, all artificial valve stents exhibited normal open and close functionality and no stenosis or insufficiency. Heart rate was slightly elevated at this time, while all other hemodynamic parameters were normal. Six-month follow-up revealed no evidence of valve stent dislocation and normal valvular and cardiac functionality. There was no evidence of stent fracture. Repeated valve stent implantation was well tolerated as indicated by good valvular functionality 2 months postdelivery.ConclusionThe novel pulmonary valve stent described herein can be delivered via percutaneous femoral vein transcatheter implantation and is highly efficacious at 6 months postdelivery. Furthermore, repeated valve stent replacement was successful
Spindle oscillations are generated in the dorsal thalamus and modulated by the thalamic reticular nucleus
Spindle waves occur during the early stage of slow wave sleep and are thought to arise in the thalamic reticular nucleus (TRN), causing inhibitory postsynaptic potential spindle-like oscillations in the dorsal thalamus that are propagated to the cortex. We have found that thalamocortical neurons exhibit membrane oscillations that have spindle frequencies, consist of excitatory postsynaptic potentials, and co-occur with electroencephalographic spindles. TRN lesioning prolonged oscillations in the medial geniculate body (MGB) and auditory cortex (AC). Injection of GABA~A~ antagonist into the MGB decreased oscillation frequency, while injection of GABA~B~ antagonist increased spindle oscillations in the MGB and cortex. Thus, spindles originate in the dorsal thalamus and TRN inhibitory inputs modulate this process, with fast inhibition facilitating the internal frequency and slow inhibition limiting spindle occurrence
- …