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Biology subjects

Huang, F.

Publications and source records attributed to Huang, F..

3 recordsLinked to original sources

Pixel Quantum Efficiency Differences and Variance Stabilization for sCMOS Single Molecule Localization Microscopy Data Analysis

Optimal analysis of single molecule localization microscopy (SMLM) data acquired with a CMOS camera requires compensation for single pixel differences in gain, offset and readout noise. For some CMOS cameras we found that it is also necessary to compensate for pixel differences in sensitivity or relative quantum efficiency (RQE). We present the modifications to the original sCMOS analysis algorithm necessary to correct for these RQE differences. We also discuss the use of the Anscombe transform (AT) for variance stabilization. Removing the variance dependence on the mean allows simpler least squares fitting approaches to achieve the Cramer-Rao bound on the mixed Poisson and Gaussian distributed data typically acquired with an sCMOS camera.

biophysics

Aerobic removal of microcystin-LR by a novel native effective bacterial community designated as YFMCD4 isolated from Lake Taihu

Microcystins (MCs) are a group of monocyclic heptapeptide hepatotoxins produced by species of cyanobacteria. MC-LR is the most toxic and frequently detected MCs variant in water, which poses a great threat to the natural ecosystem and public health. Its important to seek environment-friendly and cost-efficient methods to remove MC-LR. To investigate the MC-degrading capacities of a novel indigenous bacterial community designated as YFMCD4 and the influence of environmental factors including various temperatures, MC concentrations and pH on the MC-degrading activities, the concentration of MC-LR was measured by high performance liquid chromatography. In addition, the MC-degrading mechanism containing the degradation pathway and products of YFMCD4 was studied using HPLC coupled with an ultra-high resolution LTQ Orbitrap Velos Pro ETD mass spectrometry equipped with electrospray ionization interface. The data showed MC-LR can be removed at the maximum rate of 0.5 {micro}g/(ml{middle dot}h) by YFMCD4 containing Alcaligenes faecalis and Stenotrophomonas acidaminiohila. The MC-degrading rates of YFMCD4 were significantly affected by different temperatures, pH and MC-LR concentrations. Two intermediates of a tetrapeptide and Adda appeared in the degradation process. These results illustrate that the novel bacterial community YFMCD4 can remove MC-LR effectively and completely, which indicates YFMCD4 possesses a significant potential to be used in bioremediation of water bodies contaminated by MC-LR.

ecology

HIV protease inhibitor Saquinavir inhibits toll-like receptor 4 activation by targeting receptor dimerization

Toll like receptor 4 (TLR4) is crucial in induction of innate immune response through recognition of invading pathogens or endogenous alarming molecules.Ligand-induced dimerization of TLR4 is required for the activation of downstream signaling pathways. TLR4 dimerization induces the activation of NF-kB and IRF3 through MyD88- or TRIF-dependent pathways. Saquinavir (SQV), a FDA-approved HIV protease inhibitor, has been shown to suppress the activation of NF-kB induced by HMGB1 by blocking TLR4-MyD88 association in proteasome-independent pathway. However, it remains nknown whether SQV is a HMGB1-specific and MyD88-dependent TLR4 signaling inhibitor and which precise signaling element of TLR4 is targeted by SQV. Our results showed that SQV inhibits both MyD88- and TRIF-dependent pathways in response to LPS, a critical sepsis inducer and TLR4 agonist, leading to downregulation of NF-kB and IRF3. SQV did not suppress MyD88-dependent pathway triggered by TLR1/2 agonist Pam3csk4. In the only TRIF-dependent pathway, SQV did not attenuate IRF3 activation induced by TLR3 agonist Poly(I:C). Furthermore, dimerization of TLR4 induced by LPS and HMGB1 was decreased by SQV. These results suggest that TLR4 receptor complex is the molecular target of SQV and shed light on that TLR4-mediated inmune responses and consequent risk for uncontrolled inflammation could be modulated by FDA-approved drug SQV.

immunology