16 research outputs found
Highly Sensitive Fluorescence Probe Based on Functional SBA-15 for Selective Detection of Hg2+
An inorganic–organic hybrid fluorescence chemosensor (DA/SBA-15) was prepared by covalent immobilization of a dansylamide derivative into the channels of mesoporous silica material SBA-15 via (3-aminopropyl)triethoxysilane (APTES) groups. The primary hexagonally ordered mesoporous structure of SBA-15 was preserved after the grafting procedure. Fluorescence characterization shows that the obtained inorganic–organic hybrid composite is highly selective and sensitive to Hg2+ detection, suggesting the possibility for real-time qualitative or quantitative detection of Hg2+ and the convenience for potential application in toxicology and environmental science
The association between serum uric acid levels, metabolic syndrome and cardiovascular disease in middle aged and elderly Chinese: results from the DYSlipidemia International Study
New Bounds on Capacity Region of Multiple Access Channels in Visible Light Communications
In this paper, we propose new inner and outer bounds of the capacity region for multiple access channels in visible light communication (VLC) networks under both peak and average optical power constraints. Specifically, the proposed inner bounds are established by employing the single-user capacity achieving input distribution for each user. The proposed outer bounds are derived by determining single-user capacities for each user and calculating a sum capacity upper bound by relaxing the input constraints. Numerical results show that the proposed new bounds are extremely tight and outperform existing bounds over wide ranges of SNRs
The Role of Deoxycytidine Kinase (dCK) in Radiation-Induced Cell Death
Deoxycytidine kinase (dCK) is a key enzyme in deoxyribonucleoside salvage and the anti-tumor activity for many nucleoside analogs. dCK is activated in response to ionizing radiation (IR)-induced DNA damage and it is phosphorylated on Serine 74 by the Ataxia-Telangiectasia Mutated (ATM) kinase in order to activate the cell cycle G2/M checkpoint. However, whether dCK plays a role in radiation-induced cell death is less clear. In this study, we genetically modified dCK expression by knocking down or expressing a WT (wild-type), S74A (abrogates phosphorylation) and S74E (mimics phosphorylation) of dCK. We found that dCK could decrease IR-induced total cell death and apoptosis. Moreover, dCK increased IR-induced autophagy and dCK-S74 is required for it. Western blotting showed that the ratio of phospho-Akt/Akt, phospho-mTOR/mTOR, phospho-P70S6K/P70S6K significantly decreased in dCK-WT and dCK-S74E cells than that in dCK-S74A cells following IR treatment. Reciprocal experiment by co-immunoprecipitation showed that mTOR can interact with wild-type dCK. IR increased polyploidy and decreased G2/M arrest in dCK knock-down cells as compared with control cells. Taken together, phosphorylated and activated dCK can inhibit IR-induced cell death including apoptosis and mitotic catastrophe, and promote IR-induced autophagy through PI3K/Akt/mTOR pathway
Graphene Oxides Decorated with Carnosine as an Adjuvant To Modulate Innate Immune and Improve Adaptive Immunity <i>in Vivo</i>
Current
studies have revealed the immune effects of graphene oxide
(GO) and have utilized them as vaccine carriers and adjuvants. However,
GO easily induces strong oxidative stress and inflammatory reaction
at the site of injection. It is very necessary to develop an alternative
adjuvant based on graphene oxide derivatives for improving immune
responses and decreasing side effects. Carnosine (Car) is an outstanding
and safe antioxidant. Herein, the feasibility and efficiency of ultrasmall
graphene oxide decorated with carnosine as an alternative immune
adjuvant were explored. OVA@GO-Car was prepared by simply mixing ovalbumin
(OVA, a model antigen) with ultrasmall GO covalently modified with
carnosine (GO-Car). We investigated
the immunological properties of the GO-Car adjuvant in model mice.
Results show that OVA@GO-Car can promote robust and durable OVA-specific
antibody response, increase lymphocyte proliferation efficiency, and
enhance CD4<sup>+</sup> T and CD8<sup>+</sup> T cell activation. The
presence of Car in GO also probably contributes to enhancing the antigen-specific
adaptive immune response through modulating the expression of some
cytokines, including IL-6, CXCL1, CCL2, and CSF3. In addition, the
safety of GO-Car as an adjuvant was evaluated comprehensively. No
symptoms such as allergic response, inflammatory redness swelling,
raised surface temperatures, physiological anomalies of blood, and
remarkable weight changes were observed. Besides, after modification
with carnosine, histological damages caused by GO-Car in lung, muscle,
kidney, and spleen became weaken significantly. This study sufficiently
suggest that GO-Car as a safe adjuvant can effectively enhance humoral
and innate immune responses against antigens <i>in vivo</i>