A method based on reversed-phase liquid chromatography-tandem mass spectrometry (LC/MS/MS) combined with solid phase extraction (SPE) was developed and validated for qualitative and quantitative ...detection of eight parabens in three types of water-based food simulants including distilled water, 3% acetic acid, 10% alcohol. Detection limits of eight parabens after SPE procedure were 0.005-0.010 μg/L in distilled water, 0.006-0.015 μg/L in 3% acetic acid and 0.005-0.017 μg/L in 10% alcohol. The relative standard deviations (RSDs) were in the range of 1.90-8.48% for distilled wsater, 1.01-3.73% for 3% acetic acid and 5.78-12.97% for 10% alcohol. The method could make a complement for detecting parabens migrated to food and feeds.
The Ebola virus disease spread rapidly in West Africa in 2014, leading to the loss of thousands of lives. Community engagement was one of the key strategies to interrupt Ebola transmission, and ...practical community level measures needed to be explored in the field and tailored to the specific context of communities.
First, community-level education on Ebola virus disease (EVD) prevention was launched for the community's social mobilizers in six districts in Sierra Leone beginning in November 2014. Then, from January to May of 2015, in three pilot communities, local trained community members were organized to engage in implementation of EVD prevention and transmission interruption measures, by involving them in alert case report, contact tracing, and social mobilization. The epidemiological indicators of transmission interruption in three study communities were evaluated.
A total of 6 016 community social mobilizers from 185 wards were trained by holding 279 workshops in the six districts, and EVD message reached an estimated 631 680 residents. In three pilot communities, 72 EVD alert cases were reported, with 70.8 % of them detected by trained local community members, and 14 EVD cases were finally identified. Contact tracing detected 64.3 % of EVD cases. The median duration of community infectivity for the cases was 1 day. The secondary attack rate was 4.2 %, and no third generation of infection was triggered. No health worker was infected, and no unsafe burial and noncompliance to EVD control measures were recorded. The community-based measures were modeled to reduce 77 EVD cases, and the EVD-free goal was achieved four months earlier in study communities than whole country of Sierra Leone.
The community-based strategy of social mobilization and community engagement was effective in case detection and reducing the extent of Ebola transmission in a country with weak health system. The successfully practical experience to reduce the risk of Ebola transmission in the community with poor resources would potentially be helpful for the global community to fight against the EVD and the other diseases in the future.
Agrin is believed to be a factor used by motoneurons to direct acetylcholine receptor (AChR) clustering at the neuromuscular junction. However, exactly how agrin mediates this effect remains unclear. ...Here we demonstrate that the {szligbeta}-catenin interacts with rapsyn, a molecule key for AChR clustering. Agrin stimulation increases the association of {szligbeta}-catenin with surface AChRs. Suppression of {szligbeta}-catenin expression inhibited agrin-induced AChR clustering, suggesting a necessary role of {szligbeta}-catenin in this event. The {szligbeta}-catenin action did not appear to require the function of T-cell factors (TCFs), suggesting a mechanism independent of TCF-mediated transcription. In contrast, prevention of {szligbeta}-catenin from interacting with alpha -catenin attenuated agrin-induced AChR clustering. These results suggest that {szligbeta}-catenin may serve as a link between AChRs and alpha -catenin-associated cytoskeleton, revealing a novel function of {szligbeta}-catenin in synaptogenesis.
Differential expression of the key genes controlling phenolic metabolism in allelopathic and non-allelopathic rice accessions was investigated under two nitrogen supply levels (lower and normal) ...using fluorescence quantitative-polymerase chain reaction (FQ-PCR) (Figs.2, 3). The results indicated that 9 key enzyme genes concerned were mediated by lower nitrogen level (Table 2). All of the nine genes (Table 1, Fig.4), were up-regulated by 1.9-5.4 times of the relative gene expression amounts in allelopathic rice accession, 'PI312777' under the lower nitrogen condition compared with their controls, of which PAL gene showed the highest relative gene expression amount with 5.4 times of the relative gene expressions compared with the control, while in non-allelopathic rice Lemont, seven genes were down-regulated by 29%-72% under lower nitrogen supplies compared with their controls and only two genes, i.e., phenylalanine ammonia-lyase and cinnamoyl-CoA genes were up-regulated, which however were a decrease of 22% an
Water-dispersed CdSe/Bi2Se3 core/shell QDs with a photothermal conversion coefficient of 27.09% have been synthesized by a cation exchange reaction. The microstructure and crystal structure of the ...QDs, which were confirmed by TEM and XRD, showed that partial cation exchange occurred inside the CdSe QDs. Two main mechanisms are responsible for the excellent photothermal conversion： inhibition of radiative recombination of carriers due to the formation of type-II semiconductor heterostructures, and the large surface-to-volume ratio of the QDs. Photothermal conversion experiments indicated that the CdSe/Bi2Se3 QDs showed high photothermal conversion efficiency and excellent NIR photostability.
Synapse formation requires proper interaction between pre- and postsynaptic cells. In anterograde signaling, neurons release factors to guide postsynaptic differentiation. However, less is known ...about how postsynaptic targets retrogradely regulate presynaptic differentiation or function. We found that muscle-specific conditional knockout of b-catenin (Ctnnb1, also known as b-cat) in mice caused both morphologic and functional defects in motoneuron terminals of neuromuscular junctions (NMJs). In the absence of muscle b-catenin, acetylcholine receptor clusters were increased in size and distributed throughout a wider region. Primary nerve branches were mislocated, whereas secondary or intramuscular nerve branches were elongated and reduced in number. Both spontaneous and evoked neurotransmitter release was reduced at the mutant NMJs. Furthermore, short-term plasticity and calcium sensitivity of neurotransmitter release were compromised in b-catenin-deficient muscle. In contrast, the NMJ was normal in morphology and function in motoneuron-specific b-catenin-deficient mice. Taken together, these observations indicate a role for muscle b-catenin in presynaptic differentiation and function, identifying a previously unknown retrograde signaling in the synapse formation and synaptic plasticity.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Synapse formation requires proper interaction between pre- and postsynaptic cells. In anterograde signaling, neurons release factors to guide postsynaptic differentiation. However, less is known ...about how postsynaptic targets retrogradely regulate presynaptic differentiation or function. We found that muscle-specific conditional knockout of beta-catenin (Ctnnb1, also known as beta-cat) in mice caused both morphologic and functional defects in motoneuron terminals of neuromuscular junctions (NMJs). In the absence of muscle beta-catenin, acetylcholine receptor clusters were increased in size and distributed throughout a wider region. Primary nerve branches were mislocated, whereas secondary or intramuscular nerve branches were elongated and reduced in number. Both spontaneous and evoked neurotransmitter release was reduced at the mutant NMJs. Furthermore, short-term plasticity and calcium sensitivity of neurotransmitter release were compromised in beta-catenin-deficient muscle. In contrast, the NMJ was normal in morphology and function in motoneuron-specific beta-catenin-deficient mice. Taken together, these observations indicate a role for muscle beta-catenin in presynaptic differentiation and function, identifying a previously unknown retrograde signaling in the synapse formation and synaptic plasticity.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
DNA methylation suppresses gene expression and plays a broad and important role in diverse biological processes such as development and tumor suppression 1, 2. DNA methylation is generally thought ...to be relatively stable and heritable. This view is recently changed by the discovery of TET （ten-eleven translocation） family of dioxygenases which catalyze three sequential oxidation reactions： converting 5mC first to 5hmC,
In this paper, a new constitutive model for the deformation of rock discontinuities in a geostress field is proposed, the permeability tensor with consideration of coupled hy-dromechanical behaviour ...of jointed rock masses is formulated. It is found that the influ-ence of geostatic stresses on the permeability of jointed rock masses is caused mainly by af-fecting the aperture of discontinuities and the flow paths in discontinuity networks; the hydraulic conductivity of jointed rock masses decreases in negative exponential relationwith the increase of embedded depth and in hyperbolic relation with the increase of lateral pressure coefficient. The theory of hydromechanical coupling is applicable in the study of reservoir induced earthquake.PUBLICATION ABSTRACT
PDF
