8,647 research outputs found
The novel method to reduce the silica content in lignin recovered from black liquor originating from rice straw
Difficulties in the production of lignin from rice straw because of high silica content in the recovered lignin reduce its recovery yield and applications as bio-fuel and aromatic chemicals. Therefore, the objective of this study is to develop a novel method to reduce the silica content in lignin from rice straw more effectively and selectively. The method is established by monitoring the precipitation behavior as well as the chemical structure of precipitate by single-stage acidification at different pH values of black liquor collected from the alkaline treatment of rice straw. The result illustrates the significant influence of pH on the physical and chemical properties of the precipitate and the supernatant. The simple two-step acidification of the black liquor at pilot-scale by sulfuric acid 20w/v% is applied to recover lignin at pH 9 and pH 3 and gives a percentage of silica removal as high as 94.38%. Following the developed process, the high-quality lignin could be produced from abundant rice straw at the industrial-scale
Modes of Foreign Entry under Asymmetric Information about Potential Technology Spillovers
This paper studies the effect of technology spillovers on the entry decision of a multinational enterprise into a foreign market. Two alternative entry modes for a foreign direct investment are considered: Greenfield investment versus acquisition. We find that with quantity competition a spillover makes acquisitions less attractive, while with price competition acquisitions become more attractive. Asymmetric information about potential spillovers always reduces the number of
acquisitions independently of whether the host country or the entrant has private information. Interestingly, we find that asymmetric information always hurts the entrant, while it sometimes is in favor of the host country
Effect of C-2 substitution on the stability of non-traditional cephalosporins in mouse plasma
This work is licensed under a Creative Commons Attribution 4.0 International License.A systematic study of the stability of a set of cephalosporins in mouse plasma reveals that cephalosporins lacking an acidic moiety at C-2 may be vulnerable to β-lactam cleavage in mouse plasma
A model of decay
We suggest a parameterization of the matrix element for decay using kinematic variables convenient for experimental
analysis. The contributions of intermediate - and -states up
to spin 3 have been taken into account. The angular distributions for each
discussed hypothesis have been obtained and analysed using Monte-Carlo
simulation.Comment: 24 pages, 9 figures, 1 table; V2: text in some places improved and
acknowledgments adde
Electric-field controlled spin reversal in a quantum dot with ferromagnetic contacts
Manipulation of the spin-states of a quantum dot by purely electrical means
is a highly desirable property of fundamental importance for the development of
spintronic devices such as spin-filters, spin-transistors and single-spin
memory as well as for solid-state qubits. An electrically gated quantum dot in
the Coulomb blockade regime can be tuned to hold a single unpaired spin-1/2,
which is routinely spin-polarized by an applied magnetic field. Using
ferromagnetic electrodes, however, the properties of the quantum dot become
directly spin-dependent and it has been demonstrated that the ferromagnetic
electrodes induce a local exchange-field which polarizes the localized spin in
the absence of any external fields. Here we report on the experimental
realization of this tunneling-induced spin-splitting in a carbon nanotube
quantum dot coupled to ferromagnetic nickel-electrodes. We study the
intermediate coupling regime in which single-electron states remain well
defined, but with sufficiently good tunnel-contacts to give rise to a sizable
exchange-field. Since charge transport in this regime is dominated by the
Kondo-effect, we can utilize this sharp many-body resonance to read off the
local spin-polarization from the measured bias-spectroscopy. We show that the
exchange-field can be compensated by an external magnetic field, thus restoring
a zero-bias Kondo-resonance, and we demonstrate that the exchange-field itself,
and hence the local spin-polarization, can be tuned and reversed merely by
tuning the gate-voltage. This demonstrates a very direct electrical control
over the spin-state of a quantum dot which, in contrast to an applied magnetic
field, allows for rapid spin-reversal with a very localized addressing.Comment: 19 pages, 11 figure
Cover to Volume 3
The fibroblast mitogen platelet-derived growth factor -BB (PDGF-BB) induces a transient expression of the orphan nuclear receptor NR4A1 (also named Nur77, TR3 or NGFIB). The aim of the present study was to investigate the pathways through which NR4A1 is induced by PDGF-BB and its functional role. We demonstrate that in PDGF-BB stimulated NIH3T3 cells, the MEK1/2 inhibitor CI-1040 strongly represses NR4A1 expression, whereas Erk5 downregulation delays the expression, but does not block it. Moreover, we report that treatment with the NF-κB inhibitor BAY11-7082 suppresses NR4A1 mRNA and protein expression. The majority of NR4A1 in NIH3T3 was found to be localized in the cytoplasm and only a fraction was translocated to the nucleus after continued PDGF-BB treatment. Silencing NR4A1 slightly increased the proliferation rate of NIH3T3 cells; however, it did not affect the chemotactic or survival abilities conferred by PDGF-BB. Moreover, overexpression of NR4A1 promoted anchorage-independent growth of NIH3T3 cells and the glioblastoma cell lines U-105MG and U-251MG. Thus, whereas NR4A1, induced by PDGF-BB, suppresses cell growth on a solid surface, it increases anchorage-independent growth
The Maximal Inverse Seesaw from Operator and Oscillating Asymmetric Sneutrino Dark Matter
The maximal supersymmetric inverse seesaw mechanism (MSIS)
provides a natural way to relate asymmetric dark matter (ADM) with neutrino
physics. In this paper we point out that, MSIS is a natural outcome if one
dynamically realizes the inverse seesaw mechanism in the next-to minimal
supersymmetric standard model (NMSSM) via the dimension-five operator
, with the NMSSM singlet developing TeV scale VEV; it
slightly violates lepton number due to the suppression by the fundamental scale
, thus preserving maximally. The resulting sneutrino is a
distinguishable ADM candidate, oscillating and favored to have weak scale mass.
A fairly large annihilating cross section of such a heavy ADM is available due
to the presence of singlet.Comment: journal versio
Enterovirus-associated changes in blood transcriptomic profiles of children with genetic susceptibility to type 1 diabetes
Aims/hypothesis Enterovirus infections have been associated with the development of type 1 diabetes in multiple studies, but little is known about enterovirus-induced responses in children at risk for developing type 1 diabetes. Our aim was to use genome-wide transcriptomics data to characterise enterovirus-associated changes in whole-blood samples from children with genetic susceptibility to type 1 diabetes. Methods Longitudinal whole-blood samples (356 samples in total) collected from 28 pairs of children at increased risk for developing type 1 diabetes were screened for the presence of enterovirus RNA. Seven of these samples were detected as enterovirus-positive, each of them collected from a different child, and transcriptomics data from these children were analysed to understand the individual-level responses associated with enterovirus infections. Transcript clusters with peaking or dropping expression at the time of enterovirus positivity were selected as the enterovirus-associated signals. Results Strong signs of activation of an interferon response were detected in four children at enterovirus positivity, while transcriptomic changes in the other three children indicated activation of adaptive immune responses. Additionally, a large proportion of the enterovirus-associated changes were specific to individuals. An enterovirus-induced signature was built using 339 genes peaking at enterovirus positivity in four of the children, and 77 of these genes were also upregulated in human peripheral blood mononuclear cells infected in vitro with different enteroviruses. These genes separated the four enterovirus-positive samples clearly from the remaining 352 blood samples analysed. Conclusions/interpretation We have, for the first time, identified enterovirus-associated transcriptomic profiles in whole-blood samples from children with genetic susceptibility to type 1 diabetes. Our results provide a starting point for understanding the individual responses to enterovirus infections in blood and their potential connection to the development of type 1 diabetes.Peer reviewe
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