Rosaarnold6840

Owing to the advantage of atomic utilization, the single-atom catalyst has attracted much attention and been employed in multifarious catalytic reactions. Its definite site configuration is favorable for exploring the actual active centers and corresponding reaction mechanism. At the atomic scale, the tunable site configuration, from central metal atoms, coordinated heteroatoms, peripheral dopants, and feasible polymetallic centers to the synergetic intrinsic carbon defects, can effectively augment the intrinsic activity for oxygen reduction reaction (ORR). From a practical viewpoint, the propagation strategies of single-atom sites, the loading-activity relation and the structural retention during practical tests are crucial for the industrial applications. Furthermore, the activity contribution of multiple additional active centers including the active carbon sites and the pony-size well-wrapped metal species should be acknowledged. From the perspective mentioned above, this paper thoroughly analyses the consensuses, controversies, challenges and possible solutions based on the current research progress, thereby providing inspiration and guidance for the active center engineering of single-atom catalysts.Bendiocarb, a type of carbamate pesticide, plays a crucial role in controlling a wide range of pests. Due to its harmful impact on humans and the environment, the need for inexpensive, portable, efficient and easy-to-use analytical devices has become essential. In this study, an environmentally friendly paper-based analytical device (PAD) with a chemiluminescence (CL) sensing platform was investigated and characterized for the facile, reliable and sensitive detection of the bendiocarb pesticide. It is based on the enhancing effect of SO32- on the CL reaction of sulfur, nitrogen-doped carbon quantum dots (S,N-CQDs)-KMnO4 in acidic media. According to the experiments, S,N-CQDs and SO32- both are oxidized by KMnO4 to generate (S,N-CQDs*) and (SO2*) in their excited states, emitting at 510 nm. This indicates that an energy transfer process is taking place from SO2* to S,N-CQDs, resulting in a remarkably intensified CL emission. Interestingly, another emission was also observed around 660 nm contributing to about 20 to 25% of the total CL emission. This emission is related to the Mn2+* species produced by reducing MnO4-. The established multi-emission CL system was tested for analytical applications. Under optimal experimental conditions, a good linear relationship was observed between the bendiocarb concentration and the CL intensity of the established CL system. The linear detection range was 0.1-10 μg mL-1, with a limit of detection (LOD) of 0.02 μg mL-1. Finally, the method was successfully applied for the measurements of bendiocarb in water and juice samples. The obtained recovery values (97.5-105.5) verified the suitable accuracy of the results.The adaptive response of bones to mechanical loading is essential for musculoskeletal development. Despite the importance of collagen in bone mineralization, little is known about how cyclic strain influences physicochemical responses of collagen, especially at the early stage of mineralization when the levels of strain are higher than those in mature bones. The findings in this study show that, without any cell-mediated activity, cyclic strain increases nucleation rates of calcium phosphate (CaP) nanocrystals in highly-organized collagen matrices. The cyclic strain enhances the transport of mineralization fluids with nucleation precursors into the matrix, thus forming more CaP nanocrystals and increasing the elastic modulus of the collagen matrix. The results also suggest that the multiscale spatial distribution of nanocrystals in the fibrous collagen network determines tissue-level mechanical properties more critically than the total mineral content. By linking nano- and micro-scale observations with tissue-level mechanical properties, we provide new insights into designing better biomaterials.The exploration of efficient electrocatalysts for the hydrogen evolution reaction (HER) is beneficial to obtain renewable clean energy. Herein, a new parkerite-type compound Pt3Bi2S2 was synthesized, constructed by [PtBi4S2] octahedra. The Bi 6p orbital electrons upshift the Pt 5d band to promote hydrogen adsorption. Moreover, the Bi-Pt orbital hybridization greatly improves the conductivity and accelerates the charge transfer during the electrocatalytic process. Hence, Pt3Bi2S2 exhibits a superior catalytic activity for the HER with a low overpotential of 61 mV (at j = 10 mA cm-2) and a Tafel slope of 51 mV dec-1. In addition, Pt3Bi2S2 has higher stability than commercial Pt/C. This work proposes a promising strategy for designing new excellent HER catalysts.An accurate and specific detection of viable Candida albicans (C. albicans) in vaginal discharge is crucial for the diagnosis of vulvovaginal candidiasis (VVC) and assessment of antifungal effects. In this study, improved propidium monoazide (PMAxx) and loop-mediated isothermal amplification (LAMP) were used for the first time to distinguish between viable and dead C. albicans. A portable microfluidic chip system was developed to detect multiple viable pathogens in parallel. The consumption of samples and reagents in per reaction cell were only 0.94 μL, less than 1/25 of the conventional 25 μL Eppendorf tubular test method, both significantly reducing testing cost and greatly simplifying the detection of multiple viable pathogens. The concentration of PMAxx was optimized against C. albicans at 4.0 log CFU mL-1 to 5.0 log CFU mL-1, and 1 μM PMAxx was proven to be suitable for the detection of C. albicans in clinical samples. When testing mixtures containing different ratios of viable to dead C. albicans, PMAxx-LAMP could circumvent the signal arising from dead cells and, therefore, reflected the abundance of viable cells precisely. Furthermore, the suitability of this technique to evaluate the effects of antifungal agents, including clotrimazole, miconazole, and tioconazole, was assessed. Finally, the viability of Escherichia coli (E. coli) and C. albicans were detected on the portable microfluidic chip system. PMAxx-LAMP based portable microfluidic chip system was determined to be a feasible technique for assessing the viability of multiple pathogens in gynecology and might provide insights into new VVC treatment strategies.As a bioelectronic material used in personalized medicine, it is necessary to integrate excellent adhesion and stretchability in hydrogels for ensuring biosafety. Herein, a high-performance multifunctional hydrogel of polyvinyl alcohol-sodium alginate-g-dopamine-silver nanowire-borax (PSAB) is reported. It can not only easily adhere to the surface of various substrates, but also exhibit excellent mechanical properties. Its tensile strength, elongation at break and toughness are 0.286 MPa, 500% and 55.15 MJ m-3, respectively. The excellent mechanical properties and high conductivity guarantee that the PSAB hydrogel can successfully serve as a multifunctional sensor for detecting small activities and large-scale movements of the human body through strain and pressure changes. Meanwhile, the long-lasting potent and broad-spectrum antibacterial activity, combined with good in vitro biocompatibility, guarantees the biological safety and non-toxicity of the PSAB hydrogel. These compelling features, such as high flexibility and elasticity, high adhesion, multi-functional sensing and recyclability, as well as biological safety, pave the way for the application of PSAB hydrogel e-skin in biomedicine.The CRISPR-Cas9 system is a powerful tool for genome editing, which can potentially lead to new therapies for genetic diseases. To date, various viral and non-viral delivery systems have been developed for the delivery of CRISPR-Cas9 in vivo. However, spatially and temporally controlled genome editing is needed to enhance the specificity in organs/tissues and minimize the off-target effects of editing. In this review, we summarize the state-of-the-art non-viral vectors that exploit external stimuli (i.e., light, magnetic field, and ultrasound) for spatially and temporally controlled genome editing and their in vitro and in vivo applications.Herein we reported a highly diastereoselective synthesis of quaternary 3-amino oxindoles bearing an acetal unit via a palladium catalyzed three-component cascade umpolung allylation/acetalation process. An array of 3-amino 3-allyl oxindoles incorporating diversified functional groups were prepared in good yields with exclusive diastereoselectivities. Further investigation demonstrated that the current method could also be extended to cascade umpolung allenylation/acetalation.Poly(ethylene glycol) (PEG) is frequently used for liposomal surface modification. However, as PEGylated liposomes are cleared rapidly from circulation upon repeated injections, substitutes of PEG are being sought. We focused on a water-soluble polymer composed of 2-methacryloyloxyethyl phosphorylcholine (MPC) units, and synthesized poly(MPC) (PMPC)-conjugated lipid (PMPC-lipid) with degrees of MPC polymerization ranging from 10 to 100 (calculated molecular weight 3 to 30 kDa). In addition, lipids with three different alkyl chains, myristoyl, palmitoyl, and stearoyl, were applied for liposomal surface coating. We studied the interactions of PMPC-lipids with plasma albumin, human complement protein C3 and fibrinogen using a quartz crystal microbalance with energy dissipation, and found that adsorption of albumin, C3 and fibrinogen could be suppressed by coating with PMPC-lipids. TGF-beta inhibitor In particular, the effect was more pronounced for PMPC chains with higher molecular weight. We evaluated the size, polydispersity index, surface charge, and membrane fluidity of the PMPC-lipid-modified liposomes. We found that the effect of the coating on the dispersion stability was maintained over a long period (98 days). Furthermore, we also demonstrated that the anti-PEG antibody did not interact with PMPC-lipids. Thus, our findings suggest that PMPC-lipids can be used for liposomal coating.Ulcerative colitis (UC) is an idiopathic inflammatory condition of colorectal regions. Existing therapies for UC face grave lacunae including off-target and other harmful side effects, extensive first-pass metabolism, rapid clearance, limited or poor drug absorption and various other limitations, resulting in lower bioavailability. These conditions demand advanced delivery strategies to inflammatory colonic conditions so that drugs can counter stomach acid, avail protective strategies at this pH and selectively deliver drugs to the colon. Therefore, this approach was undertaken to develop and characterize nanoparticles for the delivery of drugs glycyrrhizic acid as well as budesonide in UC. Biocompatible and biodegradable aminocellulose-conjugated polycaprolactone containing budesonide was covered onto gelatinous nanoparticles (NPs) loaded with GA. Nanoparticles were prepared by the solvent evaporation technique, which showed particle size of ∼230 nm, spherical shape, almost smooth morphological characters under transmission, scanning and atomic force microscopy. These NPs also improved disease activities like occult blood in the stool, length of the colon and fecal properties. The nanoparticle therapy appreciably decreased colonic mast cellular infiltration, significantly maintained mucin protection, ameliorated histological features of the colon. Furthermore, markers of inflammation such as iNOS, COX-2, IL1-β, TNF-α, NO, and MPO were also appreciably ameliorated with the therapy of dual drug-loaded nanoparticles. Overall, these results establish that dual drug-loaded core-shell NPs exhibit superior therapeutic properties over the free or naïve forms of GA and budesonide in acute colon inflammation and present advantages that may be assigned to their ability to significantly inhibit colon inflammatory conditions.