168 research outputs found
The Parameterized Complexity of Centrality Improvement in Networks
The centrality of a vertex v in a network intuitively captures how important
v is for communication in the network. The task of improving the centrality of
a vertex has many applications, as a higher centrality often implies a larger
impact on the network or less transportation or administration cost. In this
work we study the parameterized complexity of the NP-complete problems
Closeness Improvement and Betweenness Improvement in which we ask to improve a
given vertex' closeness or betweenness centrality by a given amount through
adding a given number of edges to the network. Herein, the closeness of a
vertex v sums the multiplicative inverses of distances of other vertices to v
and the betweenness sums for each pair of vertices the fraction of shortest
paths going through v. Unfortunately, for the natural parameter "number of
edges to add" we obtain hardness results, even in rather restricted cases. On
the positive side, we also give an island of tractability for the parameter
measuring the vertex deletion distance to cluster graphs
Transcriptomic and proteomic insight into the effects of a defined European mistletoe extract in Ewing sarcoma cells reveals cellular stress responses
Background The hydrophobic triterpenes, oleanolic and betulinic acid as well
as the hydrophilic mistletoe lectins and viscotoxins possess anticancer
properties. They do all occur in combination in European mistletoe (Viscum
album L.). Commercial Viscum album L. extracts are aqueous, excluding the
insoluble triterpenes. We have previously shown that mistletoe lectins and
triterpene acids are effective against Ewing sarcoma in vitro, ex vivo and in
vivo. Methods We recreated a total mistletoe effect (viscumTT) by combining an
aqueous extract (viscum) and a triterpene extract (TT) solubilised with
cyclodextrins and analysed the effects of viscumTT and the single extracts on
TC-71 Ewing sarcoma cells in vitro by transcriptomic and proteomic profiling.
Results Treatment with the extracts strongly impacted Ewing sarcoma cell gene
and protein expression. Apoptosis-associated and stress-activated genes were
upregulated, proteasomal protein abundance enhanced and ribosomal and
spliceosomal proteins downregulated. The mechanism of action of viscum, TT and
viscumTT in TC-71 and MHH-ES-1 cells suggests the involvement of the unfolded
protein response. While viscum and viscumTT extract treatment indicate
response to oxidative stress and activation of stress-mediated MAPK
signalling, TT extract treatment suggests the involvement of TLR signalling
and autophagy. Conclusions Since the combinatory extract viscumTT exerts
highly effective pro-apoptotic effects on Ewing sarcoma cells in vitro, this
phytopolychemotherapy could be a promising adjuvant therapeutic option for
paediatric patients with Ewing sarcoma
A Meta-Analysis on the Effects of Hydroxychloroquine on COVID-19.
Introduction Since December 2019, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has rapidly spread throughout the world with a large medical and economic impact. On March 12, 2020, the World Health Organization (WHO) classified SARS-CoV-2 as a pandemic. As a result of this worldwide public health crisis, politicians, elected officials, and healthcare professionals emergently began trialing hydroxychloroquine (HCQ) in efforts to treat and prevent the transmission of the virus. This meta-analysis was performed to assess the effects of HCQ on patients with COVID-19. Methods This meta-analysis adheres to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRIMA) guidelines. Selected articles published between December 2019 and July 2020 were found utilizing the following search engines: PubMed, Google Scholar, Cochrane Library, DisasterLit, Clinicaltrials.gov, Medrxiv, and Embase. Two independent physician reviewers screened eligible articles that met the inclusion and exclusion criteria of the analysis. The outcome measures analyzed were mortality rate, rate of disease progression/improvement, rate of disease severity, and adverse effects of treatment. Six out of 14 studies that met the study\u27s eligibility criteria were selected and further analyzed, with a total of 381 participants (n= 381). Conclusion From the studies analyzed, it was found that groups treated with HCQ had an overall mortality rate that was 2.5 times greater than that of the control group. HCQ treated patients had higher rates of adverse clinical outcomes and side effects compared with the control populations. Lastly, there was a 1.2 times higher rate of improvement in the group of HCQ treated patients with mild to moderate symptoms as compared to the control group
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New insight into kinetics behavor of the structural formation process in Agar gelation
A time-resolved experimental study on the kinetics and relaxation of the
structural formation process in gelling Agar-water solutions was carried out
using our custom-built torsion resonator. The study was based on measurements
of three naturally cooled solutions with agar concentrations of 0.75%, 1.0% and
2.0% w/w. It was found that the natural-cooling agar gelation process could be
divided into three stages, sol stage (Stage I), gelation zone (Stage II) and
gel stage (Stage III), based on the time/temperature evolutions of the
structural development rate (SDR). An interesting fluctuant decaying behavior
of SDR was observed in Stage II and III, indicative of a sum of multiple
relaxation processes and well described by a multiple-order Gaussisn-like
equation: . More interestingly, the temperature dependences of the fitted
values of Wn in Stage II and Stage III were found to follow the different
Arrhenius laws, with different activation energies of EaII= 39-74 KJ/mol and
EaIII~7.0 KJ/mol. The two different Arrhenius-like behaviors respectively
suggest that dispersions in Stage II be attributed to the relaxation of the
self-assembly of agar molecules or the growth of junction zones en route to
gelation, in which the formation or fission of hydrogen bonding interactions
plays an important role; and that dispersions in Stage III be attributed to the
relaxation dynamics of water released from various size domains close to the
domain of the viscous flow of water during the syneresis process.Comment: 24 pages, 4 figures, 1 tabl
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