Exosomes: Versatile Nano Mediators of Immune Regulation.

One of many types of extracellular vesicles (EVs), exosomes are nanovesicle structures that are released by almost all living cells that can perform a wide range of critical biological functions. Exosomes play important roles in both normal and pathological conditions by regulating cell-cell communication in cancer, angiogenesis, cellular differentiation, osteogenesis, and inflammation. Exosomes are stable in vivo and they can regulate biological processes by transferring lipids, proteins, nucleic acids, and even entire signaling pathways through the circulation to cells at distal sites. Recent advances in the identification, production, and purification of exosomes have created opportunities to exploit these structures as novel drug delivery systems, modulators of cell signaling, mediators of antigen presentation, as well as biological targeting agents and diagnostic tools in cancer therapy. This review will examine the functions of immunocyte-derived exosomes and their roles in the immune response under physiological and pathological conditions. The use of immunocyte exosomes in immunotherapy and vaccine development is discussed

Isocorydine Inhibits Cell Proliferation in Hepatocellular Carcinoma Cell Lines by Inducing G2/M Cell Cycle Arrest and Apoptosis

The treatment of human hepatocellular carcinoma (HCC) cell lines with (+)-isocorydine, which was isolated and purified from Papaveraceae sp. plants, resulted in a growth inhibitory effect caused by the induction of G2/M phase cell cycle arrest and apoptosis. We report that isocorydine induces G2/M phase arrest by increasing cyclin B1 and p-CDK1 expression levels, which was caused by decreasing the expression and inhibiting the activation of Cdc25C. The phosphorylation levels of Chk1 and Chk2 were increased after ICD treatment. Furthermore, G2/M arrest induced by ICD can be disrupted by Chk1 siRNA but not by Chk2 siRNA. In addition, isocorydine treatment led to a decrease in the percentage of CD133+ PLC/PRF/5 cells. Interestingly, isocorydine treatment dramatically decreased the tumorigenicity of SMMC-7721 and Huh7 cells. These findings indicate that isocorydine might be a potential therapeutic drug for the chemotherapeutic treatment of HCC

Formation, diffusion, and accreting pollution of DB white dwarfs

Context. Over 1500 DBZ or DZ white dwarfs (WDs) have been observed so far, and polluted atmospheres with metal elements have been found among these WDs. The surface heavy element abundances of known DBZ or DZ WDs show an evolutionary sequence. Cooling, diffusion, and accretion are important physical processes in WD evolution which can alter the element abundances of the WD surface. Aims. Using the stellar evolutionary code, we investigated the DB WD formation and the effects of input parameters −, including the mixing length parameter (αMLT), thermohaline mixing efficiency (αth), and the metallicity (Z) −, on the structures of these DB WDs. The impacts of the convective zone mass (Mcvz), cooling timescales, diffusive timescales (τdiff), and the mass-accretion rate (Ṁa) on the element abundances of the WDs’ surfaces are discussed. By comparing the theoretical model results with observations, we try to understand the evolutionary sequence of the heavy element abundance on DBZ WD surfaces. Methods. By using Modules for Experiments in Stellar Evolution, we created DB WDs, and simulated the element diffusion due to high gravitational fields and the metal-rich material accretion coming from the planet disrupted by the WD. Then, we calculated the element abundances of these DB WDs for a further comparison with observations. Results. In our models, the input parameters (αMLT, αth, and Z) have a very weak effect on DB WD structures, including interior temperatures, chemical profiles, and convective zones. They hardly affect the evolution of the heavy elements on the surface of DB WDs. The mass-accretion rate and the effective temperature of DB WDs determine the abundances of heavy elements. The evolutionary sequence of the Ca element for about 1500 observed DB or DBZ WDs cannot be explained by the model with a constant mass-accretion rate, but it is very consistent with the model in which the mass-accretion rate decreases by one power law when Teff > 10 kK and it slightly increases by another power law when Teff < 10 kK. Conclusions. The observed DB WD evolutionary sequence of heavy element abundances originates from WD cooling and the change in the mass-accretion rate

Energy-Latency Attacks to On-Device Neural Networks via Sponge Poisoning

In recent years, on-device deep learning has gained attention as a means of developing affordable deep learning applications for mobile devices. However, on-device models are constrained by limited energy and computation resources. In the mean time, a poisoning attack known as sponge poisoning has been developed.This attack involves feeding the model with poisoned examples to increase the energy consumption during inference. As previous work is focusing on server hardware accelerators, in this work, we extend the sponge poisoning attack to an on-device scenario to evaluate the vulnerability of mobile device processors. We present an on-device sponge poisoning attack pipeline to simulate the streaming and consistent inference scenario to bridge the knowledge gap in the on-device setting. Our exclusive experimental analysis with processors and on-device networks shows that sponge poisoning attacks can effectively pollute the modern processor with its built-in accelerator. We analyze the impact of different factors in the sponge poisoning algorithm and highlight the need for improved defense mechanisms to prevent such attacks on on-device deep learning applications.Comment: Accepted to AsiaCCS Workshop on Secure and Trustworthy Deep Learning Systems (SecTL 2023