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This work details the synthesis and characterization of low-coordinate Zn(II)-based organocations [(NHC)Zn(R)]+ incorporating extremely bulky NHCs [ITr] and [IAd] ([ITr] = ([ITr] = [(HCNCPh3)2C:]; [IAd] = [(HCNAd)2C:], Ad = adamantyl)). Their structural features and particularities are thoroughly assessed as well as their air and water tolerance. Neutral ITr and IAd adducts [(ITr)Zn(R)2] (1, R = Me; 2, R = Et) and [(IAd)Zn(R)2] (3, R = Me; 4, R = Et) were synthesized by reaction of carbene [ITr] or [IAd] with a stoichiometric amount of [ZnR2] and isolated in good yields. Despite the steric bulk of [ITr] and [IAd], neutral compounds 1–4 are robust and the solid state structure of adduct 3 was established through X-ray crystallographic studies as a trigonal monomer Zn(II) species. Adducts 1–4 may readily be ionized by [Ph3C][B(C6F5)4] to afford two-coordinate Zn(II) alkyl cations [(ITr)Zn(Me)]+ ([5]+) and [(ITr)Zn(Et)]+ ([6]+), [(IAd)Zn(Me)]+ ([7]+) and [(IAd)Zn(Me)]+ ([8]+), all isolated in high yields (>80%) as [B(C6F5)4]− salts, which were fully characterized. Remarkably, cation [(ITr)Zn(C6F5)]+ ([9]+), prepared by reaction of [5][B(C6F5)4] with [B(C6F5)3], features π–arene interactions with the electrophilic Zn(II), as deduced from solid state data and further completed by DFT-estimated non-covalent interactions (NCI), indicating that [ITr] may provide substantial steric and electrostatic stabilization. The latter certainly explains the remarkable stability of [(ITr)Zn(C6F5)]+ ([9]+) towards hydrolysis at RT, as it only coordinates H2O to afford an unprecedented stable Zn–OH2 organocation [10]+. Also noteworthy, H2O coordination is reversible allowing recovery of [(ITr)Zn(C6F5)]+ cation, even after prolonged air exposure. Yet, controlled hydrolysis of [(ITr)Zn(C6F5)]+ may occur upon heating with selective protonolysis of the Zn–C6F5 bond to afford structurally characterized dication [(ITr)Zn(OH)]22+ [11]2+. Interestingly, despite steric hindrance, the air-/water-tolerant cation [(ITr)Zn(C6F5)]+ is an effective CO2 hydrosilylation catalyst, and was also shown to mediate imine hydrogenation catalysis. [ABSTRACT FROM AUTHOR]

In this work, novel microbial yeast-decorated zeolitic imidazolate framework-8 (ZIF-8/yeast) composites were successfully synthesized by an in situ growth method and applied in the efficient elimination of Eu(III) from a water medium. The adsorption performances and interaction mechanisms of Eu(III) by ZIF-8/yeast were determined by macroscopic experimental tests under diverse water chemistry conditions. The experimental results indicated that the adsorption performance of Eu(III) on ZIF-8/yeast hybrids could reach equilibrium within 15 min, which conformed to the pseudo-second-order kinetic pattern. The maximum adsorption capacity was 1.09 × 10−3 mol g−1, which was higher than that of a series of adsorbents reported in previousliterature. The interaction mechanism between ZIF-8/yeast composites and Eu(III) was primarily revealed by electrostatic attraction, cation exchange and surface complexation. According to the research, the ZIF-8/yeast is considered a preferable adsorbent for the highly efficient purification and elimination of trivalent lanthanides from radioactive wastewater. [ABSTRACT FROM AUTHOR]

Chronic and acute stress caused by emotional or physical insults can affect the function of other organs via the brain-body axis. As one of the smallest organs in mammalian, hair follicles are highly susceptible to stress. Under stress, the sympathetic nerves release norepinephrine (NA), which acts directly on the β-2 adrenergic receptors on melanocyte stem cells (MeSCs) within the hair follicles, causing the MeSCs to lose quiescence and enter a rapid proliferation state followed by differentiation and migration, leading to rapid loss of MeSCs and, ultimately, grey hair. Here, we screened out β-2 blockers forming the ZINC 15 compound database, found a natural product isoliensinine, and was effective in preventing stress-induced hair greying in mice. The study sheds light on the development of products that use natural compounds to prevent stress-induced hair greying. [ABSTRACT FROM AUTHOR]

A hierarchical hollow Ni/Co-codoped MoS2 architecture was successfully prepared using a Ni/Co Prussian Blue analogue as the precursor followed by the solvothermal-assisted insertion of MoS42− and extraction of [Co(CN)6]3− at 200 °C for 32 h. The obtained Ni/Co-codoped MoS2 composite exhibited a hollow microcubic structural characteristic, and the morphology, structure, and chemical compositions were carefully characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS), respectively. The Ni/Co-codoped MoS2 composite used as an electrode material featured excellent glucose sensing activity and a high sensitivity of 2546 μA mM−1 cm−2 with a relatively low detection limit of 0.69 μM (S/N = 3). In addition, the Ni/Co-codoped MoS2 composite showed good anti-interference sensing performance in the presence of ascorbic acid (AA), lysine (Lys), cysteine (Cys), urea, H2O2, KCl, and other interferents. These experimental results revealed that the composite is a promising electrode material for enzyme-free glucose sensing, and the feasible synthetic strategy may provide an effective and controlled route to prepare other multi-metal substituted sulfide-based hierarchical structures with high electrochemical sensing performance. [ABSTRACT FROM AUTHOR]

Surface tension and gravity, whoseinfluence on the deformationof conventional engineering materials is negligible, become importantfor soft materials that are typically used in the microfabricationof devices such as microfluidic channels. Although for soft materialsthe shape change due to these forces can be large, it is often neglectedin the design processes. To capture conditions under which the influenceof these forces is important, we propose a deformation map in whichthe shape change is captured by two dimensionless material parameters.Our idea is demonstrated by simulating the large deformation of ashort circular cylinder made of a neo-Hookean material in frictionlesscontact with a rigid substrate. These simulations are carried outusing a finite element model that accounts for surface tension andgravity. Our model integrates the two different approaches typicallyused to determine the shape change of solids and liquid drops in contactwith a substrate. [ABSTRACT FROM AUTHOR]

The Laplace pressure of a droplet placed on one side of an elastic thin film can cause significant deformation in the form of a bulge on its opposite side. Here, we show that this deformation can be detected by other droplets suspended on the opposite side of the film, leading to interaction between droplets separated by the solid (but deformable) film. The interaction is repulsive when the drops have a large overlap and attractive when they have a small overlap. Thus, if two identical droplets are placed right on top of each other (one on either side of the thin film), they tend to repel each other, eventually reaching an equilibrium configuration where there is a small overlap. This observation can be explained by analyzing the energy landscape of the droplets interacting via an elastically deformed film. We further demonstrate this idea by designing a pattern comprising a big central drop with satellite droplets. This phenomenon can lead to techniques for directed motion of droplets confined to one side of a thin elastic membrane by manipulations on the other side.

Lipoapoptosis of pancreatic beta cells caused by elevated circulating free fatty acids (FFAs) has now been recognized to be a pivotal factor contributing to beta cellular dysfunction and beta-mass lose in type 2 diabetes. Although recent studies suggested an important role for the ceramide pathway in the late destructive phase of lipid overload in the pancreatic beta cells, the overall underlying mechanisms leading to lipoapoptosis, however, remained poorly understood. mir-375 was recently characterized to be a pancreatic islet-specific miRNA implicated in the regulation of insulin secretion and beta-mass turnover. In the present study we further examined its effect on palmitate-induced lipoapoptosis in NIT-1 cells, a NOD-derived beta-cell line. It was found that NIT-1 cells with ectopic mir-375 expression were much more susceptible to palmitate-induced lipoapoptosis. In contrast, knockdown of endogenous pri-mir-375 expression by a modified antisense oligo, 2'-O-me-375, almost completely protected NIT-1 cells from palmitate-induced lipoapoptosis. We further demonstrated that mir-375 could target V1 mRNA and repress its translation. Consistent with this assumption, NIT-1 cells transfected with 2'-O-me-375 showed significant higher levels of V1 protein after palmitate induction. Together, our data suggest that mir-375 could be a potential therapeutic target for prevention and intervention of beta-cell dysfunction and beta-mass lose in type 2 diabetes.