Cytochrome (Cyt) P450s are an important class of enzymes with numerous functions in nature. The unique reactivity of these enzymes relates to their heme b active sites with an axially bound, deprotonated cysteine (a "cysteinate") ligand (chemically speaking a thiolate). The heme-thiolate active sites further contain a number of conserved hydrogen-bonds (H-bonds) to the bound cysteinate ligand, which have been proposed to tune and stabilize the Fe-S bond. In this work, we present the low-temperature preparation of five ferric heme-thiolate nitric oxide (NO) model complexes that contain one tunable hydrogen-bond to the bound thiolate ligand. We show that the presence of a H-bond has a dramatic effect in stabilizing the thiolate ligand against direct reaction with NO. This observation reinforces the important protective role of H-bonds in Cyt P450s. We further demonstrate that H-bond strength tunes thiolate donor strength, which, in turn, controls the N-O and Fe-NO stretching frequencies and hence, bond strengths. We observe a direct correlation between the Fe-NO and N-O stretching frequencies, indicative of a thiolate σ-trans effect (interaction). Here, very small changes in H-bond strength lead to a surprisingly large effect on the FeNO unit. This result implies that subtle changes in the Cys-pocket of a Cyt P450 can strongly affect reactivity. Importantly, using the Fe-NO/N-O correlation established here, the thiolate donor strength in heme-thiolate enzyme active sites and model complexes can be quantified in a straightforward way, using NO as a probe. This spectroscopic correlation provides a quantitative measure of the thiolate's "push" effect, which is important in O2-activation (Compound I formation) in Cyt P450s in general.Caenorhabditis elegans is an in vivo model known for its easy handling and maintenance and lack of associated ethical issues. The release of chitinase can be used to monitor the egg-laying stage in C. elegans. The aim of this study was to develop a simple and cost-effective device to monitor the activity of chitinase in embryos of C. elegans. Colloid chitin azure (CCA), a substrate for chitinase, was preimmobilized on the detection area of paper, forming a purple region, to generate a CCA paper-based analytical device (CCA-PAD). The degradation of CCA by chitinase could be observed as the purple color became faint and the filter paper eventually became colorless. Under the optimum conditions, the proposed device quantified the chitinase enzyme in the range of 15.625-125 mU/mL within 48 h (R2 = 0.993). In this work, 10 young adult-staged wild-type C. elegans (Bristol N2) worms were analyzed on the CCA-PAD, which was supplemented with the laboratory food source E. coli OP50 on a gauze layer. The same strain treated with 5-fluoro-2'-deoxyuridine was used to prevent egg production in C. elegans. A significant difference in the color intensity was observed between these two groups at the end of the experiment (P = less then 0.001, independent t-test, n = 3). We successfully developed a simple and effective method for monitoring chitinase activity. The device may have potential applications in drug-screening studies as it efficiently distinguishes drugs that can impact egg laying.There has been significant interest in developing cell membrane-coated nanoparticles due to their unique abilities of biomimicry and biointerfacing. As the technology progresses, it becomes clear that the application of these nanoparticles can be drastically broadened if additional functions beyond those derived from the natural cell membranes can be integrated. Herein, we summarize the most recent advances in the functionalization of cell membrane-coated nanoparticles. In particular, we focus on emerging methods, including (1) lipid insertion, (2) membrane hybridization, (3) metabolic engineering, and (4) genetic modification. These approaches contribute diverse functions in a nondisruptive fashion while preserving the natural function of the cell membranes. They also improve on the multifunctional and multitasking ability of cell membrane-coated nanoparticles, making them more adaptive to the complexity of biological systems. We hope that these approaches will serve as inspiration for more strategies and innovations to advance cell membrane coating technology.Developing a convenient and rapid detection method for water is greatly desirable in the field of chemical industry. Herein, we present a simple and effective strategy combining a fluorescence sensor and a one-to-two fluorescence colorimetric logic operation to monitor water in a wide range of organic media and classify aprotic/protic polar solvents. The dual-emitting luminescent detector was prepared by incorporating a fluorescent dye Rhodamine 6G (R6G) with strong green light emission within a red light-emitting Eu-metal-organic framework (MOF) through the "bottle around ship" method. R6G@Eu-MOF displays completely different fluorescence response behaviors to various organic solvents. Thus, when one made use of the intensity ratio of different fluorescence emission centers, a 3D decoded map was proposed to reliably and effectively distinguish different aprotic/protic polar solvents. Moreover, R6G@Eu-MOF exhibited two different ratiometric sensing modes when detecting water in aprotic/protic polar solvents due to the hydrogen bonding interaction, that is ratiometry with one reference signal or two reversible signal changes. Furthermore, using water content as the input signal and two kinds of fluorescence emission as the output signals, a one-to-two logic gate system was constructed, making it possible to develop an intelligence system for water detection. Overall, we demonstrated for the first time that R6G@Eu-MOF could serve as an efficient platform for tracing water in organic media and distinguishing protic/aprotic polar organic solvents.Solar-driven water evaporation provides a promising solution to the energy crisis and environmental issues. Capitalizing on the high photothermal conversion efficiency and excellent resistance to strong acids or strong alkalis of Pt3Ni-S nanowires, we strategically design and prepare a flexible Pt3Ni-S-deposited Teflon (PTFE) membrane for achieving efficient strong acid/alkaline water evaporation under simulated sunlight irradiation (1 sun). By comparing the surface morphology, mechanical properties, and water evaporation performance of the as-prepared three different membranes, we have screened out a high-performance photothermal membrane that has good hydrophobicity (water contact angle = 106°), strong mechanical properties, high light-to-heat conversion efficiency (η = 80%), and excellent durability (10 cycles in a range of pH = 1.2-12). https://www.selleckchem.com/products/arn-509.html In particular, we explore the mechanism of high surface mechanical properties of the as-prepared membrane using density functional theory. The results demonstrate that the related mechanism can be ascribed to two main reasons (1) hydrogen bonds can be formed between the 2-pyrrolidone ring and PTFE-3 and (2) the O atom in PTFE-3 carries more negative charge (-0.