867 research outputs found
A New Insight into Hepatitis C Vaccine Development
Chronic hepatitis C virus (HCV) infection remains a serious burden to public health worldwide. Currently, HCV-infected patients could undergo antiviral therapy by giving pegylated IFN-α with ribavirin. However, this therapy is only effective in around 50% of patients with HCV genotype 1, which accounts for more than 70% of all HCV infection, and it is not well tolerated for most patients. Moreover, there is no vaccine available. The efforts on identifying protective immunity against HCV have progressed recently. Neutralizing antibodies and robust T cell responses including both CD4+ and CD8+ have been shown to be related to the clearance of HCV, which have shed lights on the potential success of HCV vaccines. There are many vaccines developed and tested before entering clinical trials. Here, we would first discuss strategies of viral immune evasion and correlates of protective host immunity and finally review some prospective vaccine approaches against chronic HCV infection
Design Space Exploration for Distributed Cyber-Physical Systems: State-of-the-art, Challenges, and Directions
Computer Systems, Imagery and Medi
2+1 Dimensional Georgi-Glashow Instantons in Weyl Gauge
Semiclassical instanton solutions in the 3D SU(2) Georgi-Glashow model are
transformed into the Weyl gauge. This illustrates the tunneling interpretation
of these instantons and provides a smooth regularization of the singular
unitary gauge. The 3D Georgi-Glashow model has both instanton and sphaleron
solutions, in contrast to 3D Yang-Mills theory which has neither, and 4D
Yang-Mills theory which has instantons but no sphaleron, and 4D electroweak
theory which has a sphaleron but no instantons. We also discuss the spectral
flow picture of fundamental fermions in a Georgi-Glashow instanton background.Comment: 22 pages, 8 figures, revtex4; v2 - references and comments adde
Has the phasing out of stavudine in accordance with changes in WHO guidelines led to a decrease in single-drug substitutions in first-line antiretroviral therapy for HIV in sub-Saharan Africa?
This version is the Accepted Manuscript and is published in final edited form as:
AIDS. 2017 January 02; 31(1): 147–157. doi:10.1097/QAD.0000000000001307OBJECTIVE: We assessed the relationship between phasing out stavudine in first-line antiretroviral therapy (ART) in accordance with WHO 2010 policy and single-drug substitutions (SDS) (substituting the nucleoside reverse transcriptase inhibitor in first-line ART) in sub-Saharan Africa.
DESIGN: Prospective cohort analysis (International epidemiological Databases to Evaluate AIDS-Multiregional) including ART-naive, HIV-infected patients aged at least 16 years, initiating ART between January 2005 and December 2012. Before April 2010 (July 2007 in Zambia) national guidelines called for patients to initiate stavudine-based or zidovudine-based regimen, whereas thereafter tenofovir or zidovudine replaced stavudine in first-line ART.
METHODS: We evaluated the frequency of stavudine use and SDS by calendar year 2004-2014. Competing risk regression was used to assess the association between nucleoside reverse transcriptase inhibitor use and SDS in the first 24 months on ART.
RESULTS: In all, 33 441 (8.9%; 95% confience interval 8.7-8.9%) SDS occurred among 377 656 patients in the first 24 months on ART, close to 40% of which were amongst patients on stavudine. The decrease in SDS corresponded with the phasing out of stavudine. Competing risks regression models showed that patients on tenofovir were 20-95% less likely to require a SDS than patients on stavudine, whereas patients on zidovudine had a 75-85% decrease in the hazards of SDS when compared to stavudine.
CONCLUSION: The decline in SDS in the first 24 months on treatment appears to be associated with phasing out stavudine for zidovudine or tenofovir in first-line ART in our study. Further efforts to decrease the cost of tenofovir and zidovudine for use in this setting is warranted to substitute all patients still receiving stavudine
Synergistic information supports modality integration and flexible learning in neural networks solving multiple tasks
Striking progress has been made in understanding cognition by analyzing how the brain is engaged in different modes of information processing. For instance, so-called synergistic information (information encoded by a set of neurons but not by any subset) plays a key role in areas of the human brain linked with complex cognition. However, two questions remain unanswered: (a) how and why a cognitive system can become highly synergistic; and (b) how informational states map onto artificial neural networks in various learning modes. Here we employ an information-decomposition framework to investigate neural networks performing cognitive tasks. Our results show that synergy increases as networks learn multiple diverse tasks, and that in tasks requiring integration of multiple sources, performance critically relies on synergistic neurons. Overall, our results suggest that synergy is used to combine information from multiple modalities—and more generally for flexible and efficient learning. These findings reveal new ways of investigating how and why learning systems employ specific information-processing strategies, and support the principle that the capacity for general-purpose learning critically relies on the system’s information dynamics
Effects of human parvovirus B19 VP1 unique region protein on macrophage responses
<p>Abstract</p> <p>Background</p> <p>Activity of secreted phospholipase A (sPLA2) has been implicated in a wide range of cellular responses. However, little is known about the function of human parvovirus B19-VP1 unique region (VP1u) with sPLA2 activity on macrophage.</p> <p>Methods</p> <p>To investigate the roles of B19-VP1u in response to macrophage, phospholipase A2 activity, cell migration assay, phagocytosis activity, metalloproteinase assay, RT-PCR and immunoblotting were performed.</p> <p>Results</p> <p>In the present study, we report that migration, phagocytosis, IL-6, IL-1β mRNA, and MMP9 activity are significantly increased in RAW264.7 cells by B19-VP1u protein with sPLA2 activity, but not by B19-VP1uD175A protein that is mutated and lacks sPLA2 activity. Additionally, significant increases of phosphorylated ERK1/2 and JNK proteins were detected in macrophages that were treated with B19-VP1u protein, but not when they were treated with B19-VP1uD175A protein.</p> <p>Conclusion</p> <p>Taken together, our experimental results suggest that B19-VP1u with sPLA2 activity affects production of IL-6, IL-1β mRNA, and MMP9 activity, possibly through the involvement of ERK1/2 and JNK signaling pathways. These findings could provide clues in understanding the role of B19-VP1u and its sPLA2 enzymatic activity in B19 infection and B19-related diseases.</p
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