The antibacterial activity and acting mechanism of silver nanoparticles (SNPs) on Escherichia coli ATCC 8739 were investigated in this study by analyzing the growth, permeability, and morphology of the bacterial cells following treatment with SNPs. The experimental results indicated 10 microg/ml SNPs could completely inhibit the growth of 10(7) cfu/ml E. coli cells in liquid Mueller-Hinton medium. Meanwhile, SNPs resulted in the leakage of reducing sugars and proteins and induced the respiratory chain dehydrogenases into inactive state, suggesting that SNPs were able to destroy the permeability of the bacterial membranes. When the cells of E. coli were exposed to 50 microg/ml SNPs, many pits and gaps were observed in bacterial cells by transmission electron microscopy and scanning electron microscopy, and the cell membrane was fragmentary, indicating the bacterial cells were damaged severely. After being exposed to 10 microg/ml SNPs, the membrane vesicles were dissolved and dispersed, and their membrane components became disorganized and scattered from their original ordered and close arrangement based on TEM observation. In conclusion, the combined results suggested that SNPs may damage the structure of bacterial cell membrane and depress the activity of some membranous enzymes, which cause E. coli bacteria to die eventually.

Immune infiltration of tumors is closely associated with clinical outcome in renal cell carcinoma ( RCC ). Tumor‐infiltrating immune cells ( TIIC s) regulate cancer progression and are appealing therapeutic targets. The purpose of this study was to determine the composition of TIIC s in RCC and further reveal the independent prognostic values of TIIC s. CIBERSORT , an established algorithm, was applied to estimate the proportions of 22 immune cell types based on gene expression profiles of 891 tumors. Cox regression was used to evaluate the association of TIIC s and immune checkpoint modulators with overall survival ( OS ). We found that CD 8+ T cells were associated with prolonged OS (hazard ratio [ HR ] = 0.09, 95% confidence interval [ CI ].01‐.53; P = 0.03) in chromophobe carcinoma ( KICH ). A higher proportion of regulatory T cells was associated with a worse outcome ( HR = 1.59, 95% CI 1.23‐.06; P < 0.01) in renal clear cell carcinoma ( KIRC ). In renal papillary cell carcinoma ( KIRP ), M1 macrophages were associated with a favorable outcome ( HR = .43, 95% CI .25‐.72; P < 0.01), while M2 macrophages indicated a worse outcome ( HR = 2.55, 95% CI 1.45‐4.47; P < 0.01). Moreover, the immunomodulator molecules CTLA 4 and LAG 3 were associated with a poor prognosis in KIRC , and IDO 1 and PD ‐L2 were associated with a poor prognosis in KIRP . This study indicates TIIC s are important determinants of prognosis in RCC meanwhile reveals potential targets and biomarkers for immunotherapy development.

The antibacterial activity and mechanism of silver nanoparticles (Ag-NPs) on Staphylococcus aureus ATCC 6538P were investigated in this study. The experiment results showed the minimum bactericidal concentration (MBC) of Ag-NPs to S. aureus was 20 μg/ml. Moreover, when bacteria cells were exposed to 50 μg/ml Ag-NPs for 6 h, the cell DNA was condensed to a tension state and could have lost their replicating abilities. When S. aureus cells were exposed to 50 μg/ml Ag-NPs for 12 h, the cell wall was breakdown, resulting in the release of the cellular contents into the surrounding environments, and finally became collapsed. And Ag-NPs could reduce the enzymatic activity of respiratory chain dehydrogenase. Furthermore, the proteomic analysis showed that the expression abundance of some proteins was changed in the treated bacterial cell with Ag-NPs, formate acetyltransferase increased 5.3-fold in expression abundance, aerobic glycerol-3-phosphate dehydrogenase decreased 6.5-fold, ABC transporter ATP-binding protein decreased 6.2-fold, and recombinase A protein decreased 4.9-fold.

In this study, fluorescence spectroscopy in combination with UV-vis absorption spectroscopy and circular dichroism (CD) spectroscopy was employed to investigate the high affinity binding of palmatine to human serum albumin (HSA) under the physiological conditions. In the mechanism discussion it was proved that the fluorescence quenching of HSA by palmatine is a result of the formation of palmatine/HSA complex. Binding parameters calculating from Stern-Volmer method and Scatchard method showed that palmatine bind to HSA with the binding affinities of the order 10(4) L.mol(-1). The thermodynamic parameters studies revealed that the binding was characterized by negative enthalpy and positive entropy changes and the electrostatic interactions play a major role for palmatine-HSA association. Site marker competitive displacement experiments demonstrating that palmatine bind with high affinity to site I (subdomain IIA) of HSA. The specific binding distance r (2.91 nm) between donor (Trp-214) and acceptor (palmatine) was obtained according to fluorescence resonance energy transfer (FRET). Furthermore, the CD spectral result indicates that the secondary structure of HSA was changed in the presence of palmatine.