This paper presents the first reported data on the embedding of highly dielectric ceramic inclusions in a rubbery host medium as a means to increase the electromechanical material response for ...dielectric elastomer actuation. The studied polymer/ceramic composite, consisting of a silicone matrix in which titanium dioxide powder was dispersed, exhibited, in comparison with pure silicone, a decreased elastic modulus, as well as an increased dielectric constant. The measured low frequency permittivity resulted in accordance with several classical dielectric mixing rules. The use of this material as elastomeric dielectric for planar actuators enabled a reduction of the driving electric fields, so that a transverse strain of 11% at 10 V//spl mu/m and a transverse stress of 16.5 kPa at 9 V//spl mu/m were obtained. These levels of strain and stress were respectively more than eight and four times higher than the corresponding values generated with the pure polymer matrix for analogous electrical stimuli.
Three known compounds, 20-deoxyphorbol-5β-hydroxy-12-tiglate-13-isobutyrate (1), 20-deoxyphorbol-5β-hydroxy-12-tiglate-13-phenylacetate (2), and 4-deoxy-4β-phorbol-12-tiglate-13-phenylacetate (3), ...were reisolated from the latex of Euphorbia umbellata through a bioguided fractionation process to target HIV-1 latency reactivation. The in vitro bioassay using infected T-cell lymphoblasts (J-Lat 10.6), complemented with surface CD4 receptor downregulation assessment, led to isolation of the compounds as a highly active ternary mixture. Effective purification of the individual compounds was achieved by first subjecting a phorbol-enriched fraction (previously prepared from crude latex) to MPLC, followed by semipreparative HPLC and characterization by 1D and 2D NMR spectroscopy and (+)-HRESIMS. Compared with a positive control, the isolated compounds were effective in reactivating 68–75% of the virus latency in the range of 9.7–0.097 μM for compound 1, 8.85–0.088 μM for compound 2, and 9.1–0.091 μM for compound 3, with the latter maintaining steady effectiveness down to a 10–5 dilution. Accordingly, compound 3 may serve as a promising lead compound for the development of anti-HIV drugs based on latency reactivation therapy.
The aim of the current study is to evaluate the detection rate of micro- and macro-metastases of the One-Step Nucleic Acid Amplification (OSNA) compared to frozen section examination and subsequent ...ultra-staging examination in early stage endometrial cancer (EC).
From March 2016 to June 2016, data of 40 consecutive FIGO stage I EC patients were prospectively collected in an electronic database. The sentinel lymph node mapping was performed in all patients. All mapped nodes were removed and processed. Sentinel lymph nodes were sectioned and alternate sections were respectively examined by OSNA and by frozen section analysis. After frozen section, the residual tissue from each block was processed with step-level sections (each step at 200 micron) including H&E and IHC slides.
Sentinel lymph nodes mapping was successful in 29 patients (72.5%). In the remaining 11 patients (27.5%), a systematic pelvic lymphadenectomy was performed. OSNA assay sensitivity and specificity were 87.5% and 100% respectively. Positive and negative predictive values were 100% and 99% respectively, with a diagnostic accuracy of 99%. As far as frozen section examination and subsequent ultra-staging analysis was concerned, we reported sensitivity and specificity of 50% and 94.4% respectively; positive and negative predictive values were 14.3% and 99%, respectively, with an accuracy of 93.6%. In one patient, despite negative OSNA and frozen section analysis of the sentinel node, a macro-metastasis in 1 non-sentinel node was found.
The combination of OSNA procedure with the sentinel lymph node mapping could represent an efficient intra-operative tool for the selection of early-stage EC patients to be submitted to systematic lymphadenectomy.
Mild cognitive impairment (MCI) is a heterogeneous syndrome with two main clinical subtypes, amnestic (aMCI) and non-amnestic (naMCI). The analysis of heart rate variability (HRV) is a tool to assess ...autonomic function. Cognitive and autonomic processes are linked via the central autonomic network. Autonomic dysfunction entails several adverse outcomes. However, very few studies have investigated autonomic function in MCI and none have considered MCI subtypes or the relationship of HRV indices with different cognitive domains and structural brain damage. We assessed autonomic function during an active orthostatic challenge in 253 oupatients aged ≥ 65, n = 82 aMCI, n = 93 naMCI, n = 78 cognitively normal (CN), neuropsychologically tested with power spectral analysis of HRV. We used visual rating scales to grade cerebrovascular burden and hippocampal/insular atrophy (HA/IA) on neuroimaging. Only aMCI showed a blunted response to orthostasis. Postural changes in normalised low frequency (LF) power and in the LF to high frequency ratio correlated with a memory test (positively) and HA/IA (negatively) in aMCI, and with attention/executive function tests (negatively) and cerebrovascular burden (positively) in naMCI. These results substantiate the view that the ANS is differentially impaired in aMCI and naMCI, consistently with the neuroanatomic substrate of Alzheimer's and small-vessel subcortical ischaemic disease.
Efficient server maintenance and update is essential to prevent performance and security issues in edge computing environments. Despite many initiatives in maintenance planning, state-of-the-art ...approaches concentrate on carrying out updates in cloud data centers, ignoring aspects of the problem that are specific to the edge computing paradigm, such as user-location awareness. In this letter, we present two maintenance strategies, called Lamp and Laxus, that consider users' locations when performing migration decisions to avoid delay bottlenecks during edge servers maintenance. Results show that the proposed strategies can reduce maintenance time by 44.27% compared to existing strategies while effectively avoiding delay bottlenecks.
The release of glutamate during brain anoxia or ischaemia triggers the
death of neurons, causing mental or physical handicap. The
mechanism of glutamate release is controversial, however. Four ...release mechanisms
have been postulated: vesicular release dependent on external calcium or Ca2+ released from intracellular stores;
release through swelling-activated anion channels; an indomethacin-sensitive
process in astrocytes; and reversed operation of glutamate
transporters. Here we have mimicked severe ischaemia in
hippocampal slices and monitored glutamate release as a receptor-gated current
in the CA1 pyramidal cells that are killed preferentially in ischaemic hippocampus.
Using blockers of the different release mechanisms, we demonstrate that glutamate
release is largely by reversed operation of neuronal glutamate transporters,
and that it plays a key role in generating the anoxic depolarization that
abolishes information processing in the central nervous system a few minutes
after the start of ischaemia. A mathematical model incorporating K
+ channels, reversible uptake carriers and NMDA (N-methyl-
D-aspartate) receptor channels reproduces the main features of the response
to ischaemia. Thus, transporter-mediated glutamate homeostasis fails dramatically
in ischaemia: instead of removing extracellular glutamate to protect neurons,
transporters release glutamate, triggering neuronal death.