Rothmcfarland8587

A lanthanum(iii) metal-organic framework, PCMOF21-AcO [La2(H2L)1.5(AcO)3·(H2O)5.59], with a 3-D network linked by dicationic bis(dimethylphosphonato)bipiperidinium units and both coordinated and free acetate counter anions is reported. PCMOF21-AcO was water stable and showed very good proton conductivity >10-3 S cm-1 at 85 °C and 95% relative humidity. PCMOF21-AcO also showed a bimodal particle size distribution and so proton conductivity was further examined as a function of particle size. Large (≥220 μm), intermediate (125 ≤x less then 180 μm) and small ( less then 38 μm) particles were sieved and proton conductivity compared. The larger particle samples showed better proton conduction, an observation that supports grain boundaries being a hurdle to proton conduction rather than an enabler (e.g. by degradation routes enabling ion mobility). Proton conductivity as a function of pelletization pressure was also studied and affirmed that, for this system, the single semicircular feature observed in impedance analysis accounted for bulk and grain boundary contributions.Measuring the electrode potential with spatio-temporal resolution is of essential importance for surface electrochemistry, energy storage and conversion among others. Optical imaging of the electrode potential distribution on transparent electrodes (ITO, FTO and single-layer graphene, etc.) is successfully achieved by using oblique incident reflectivity difference (OIRD) technology.Naturally available compounds with bioactivity are potential candidates for cancer treatment. In this paper, we isolated hypericin (HC) from Hypericum sinense L. and investigated its antitumor activity both in vitro and in vivo. The nanoparticles (NPs) of HC were prepared by a nanoprecipitation process with 1,2-distearoyl-sn-glycero-3-phospho-ethanolamine-N-[methoxy(polyethylene glycol)-2000] (DSPE-PEG-2000). With light irradiation, HC NPs not only undergo efficient electron transfer to generate the superoxide radical (O2-˙) and the hydroxyl radical (OH˙) as well as energy transfer producing singlet oxygen (1O2) for photodynamic therapy (PDT), but also non-radiative decay to produce heat for photothermal therapy (PTT) with a photothermal conversion efficiency of 29.3%. This synergistic therapy, therefore, largely boosts the phototherapy efficacy of HC NPs on human cervical cancer cells (HeLa), guaranteeing a low half maximal inhibitory concentration (IC50) of only 5.6 μg mL-1. Furthermore, in vivo studies suggest that HC NPs are capable of inhibiting tumor proliferation after laser irradiation, and the main organs remain healthy, including the heart, kidneys, liver, lungs and spleen. Our results indicate that HC NPs derived from nature with excellent phototherapy efficacies are biocompatible candidates for type I PDT/PTT synergistic cancer therapy.Laser ablation in conjunction with optical emission spectroscopy is a potential non-contact, stand-off detection method for all elements in the periodic table and certain isotopes such as radionuclides. Currently, significant development efforts are on-going to use ultrafast laser filaments for remote detection of materials. The application of filaments is of particular interest in extending the range of stand-off capability associated with elemental and isotopic detection via laser-induced breakdown spectroscopy. In this study, we characterize the expansion dynamics and chemical evolution of filament-produced uranium (U) plasmas. Laser filaments are generated in the laboratory by loosely focusing 35 femtosecond (fs), 6 milli Joule (mJ) pulses in air. Time-resolved, two-dimensional plume and spectral imaging was performed to study hydrodynamics and evolution of U atomic and UO molecular emission in filament-produced U plasmas. Our results highlight that filament ablation of U plasmas gives a cylindrical plume morphology with an appearance of plume splitting into slow and fast moving components at later times of its evolution. Emission from the slow-moving component shows no distinct spectral features (i.e. PI3K inhibitor broadband-like) and is contributed in part by nanoparticles generated during ultrafast laser ablation. Additionally, we find U atoms and U oxide molecules (i.e. UO, UxOy) co-exist in the filament produced plasma, which can be attributed to the generation of low-temperature plasma conditions during filament ablation.The traditional detection of telomerase activity is mainly based on the polymerase chain reaction (PCR), which has the disadvantages of being time-consuming and susceptible to interferences; thus, here, we propose a facile method for the fabrication of fluorescent tungsten oxide quantum dots (WOx QDs) and employ them for telomerase activity sensing. It is found that the fluorescence of WOx QDs can be significantly quenched by hemin based on the inner filter effect (IFE). However, in the presence of telomerase, the primer-DNA can be extended to generate repeating units of TTAGGG to form G-quadruplex and thus, hemin can be encapsulated to reduce its absorbance, resulting in decreased IFE and efficient fluorescence recovery of WOx QDs. Based on the fluorescence changes of IFE between hemin and WOx QDs, the telomerase activity within the range of 50-30 000 HeLa cells can be detected and the lowest detection amount can reach 17 cells. The method exhibits good versatility that can also be applied to telomerase detection in A549 and L929 cells. In addition, because of the good biocompatibility of the sensor, it can be used for the real-time monitoring of telomerase activity in living cells, thus showing great potential in tumor diagnosis and inhibitor drug screening.All cells require Cu as a cofactor, but Cu2+ induces toxicity and oxidative damage. A strict system is thus needed to maintain Cu homeostasis. Using the ZFL zebrafish liver cell line as a model, we studied the cellular responses after exposure to Cu2+, using whole-transcriptome shotgun sequencing (RNA-seq) to screen nearly all transcriptomes in cell samples and identify changes in gene expression. ZFL cells were treated with 100, 200, or 400 μM CuCl2 and harvested after 4 and 24 h. RNA was then extracted and subjected to RNA-Seq and qPCR validation. Exposure to 400 μM CuCl2 for 4 h and 24 h led to the regulation of 5993 and 4235 genes, respectively. In a gene ontology enrichment analysis, Cu2+ exposure enriched the nitrogen compound metabolic process and antioxidant activity but did not significantly affect cellular copper, zinc, iron and calcium ion homeostasis. In a KEGG pathway enrichment analysis, anti-oxidative stress induced the glutathione metabolism pathway. Furthermore, Cu2+ also induced genes related to apoptosis and arrested the cell cycle in the G2 phase. This study was based on the full gene expression profile combined with pathway analysis details, providing a full cellular response picture for Cu.Two unique hybrid tin iodides, with generic compositions A0.5A'0.5SnI3 and A1.5A'0.5SnI4 have been prepared. link2 Each shows ordering of the two organic moieties (A and A') on distinct crystallographic sites, leading to novel 3D and 2D structure types, respectively.Layered Ruddlesden-Popper (RP) phase perovskites, with a formula of A'2MAn-1Pbn3n+1 (where A' is an organic cation, MA is methylammonium, n is the integer for the number of inorganic sheets [PbI6] between the organic cation spacers), are of high interest due to their chemical stability. However, the low-n phases (e.g., n = 1, 2) not only act as carrier traps, but also hinder carrier transport within the layered RP perovskites, leading to a decreased photovoltaic performance for their corresponding devices. Herein, we report that a solvent additive-induced Ostwald ripening process effectively promotes the reduction of low-n phases and uniform RP perovskites composition. Note that the solvent added, such as ethylene glycol as an example, should have selective solubility to organic cations, and be less volatile but have a higher boiling point than the host solvents such as N,N-dimethylformamide (DMF). During fast spin-coating at room temperature, the host solvent DMF quickly evaporates while the low-n phase perovskite films are formed due to a smaller nucleation barrier, allowing the contained solvent additive, ethylene glycol, to act as a plasticizer. Then, annealing at 100 °C, causes a slow release of the restrained solvent additive which recrystallizes the perovskite grains with low-n phases into high-n phases (e.g., n≥3) in the (ClPEA)2MA3Pb4I13 (where ClPEA is 2-(4-chlorophenyl)ethanaminium) layered RP phase perovskites. When used in solar cells, the device with a configuration of ITO/PEDOTPSS/RP perovskite/PC61BM/BCP/Ag showed an enhanced 11% power conversion efficiency, which can be attributed to the decreased trap-state density and the increased carrier transport induced by the solvent additive.A new class of white luminescent materials, white-light-emitting graphene quantum dots (WGQDs), have attracted increasing attention because of their unique features and potential applications. Herein, we designed and synthesized a novel WGQDs via a solvothermal molecular fusion strategy. The modulation of chlorine doping amount and reaction temperature gives the WGQDs a single-crystalline structure and bright white fluorescence properties. In particular, the WGQDs also exhibit novel and robust white phosphorescence performance for the first time. An optimum fluorescence quantum yield of WGQDs is 34%, which exceeds the majority of reported WGQDs and other white luminescent materials. The WGQDs display broad-spectrum absorption within almost the entire visible light region, broad full width at half maximum and extend their phosphorescence emission to the entire white long-wavelength region. This unique dual-mode optical characteristic of the WGQDs originates from the synergistic effect of low-defect and high chlorine-doping in WGQDs and enlarges their applications in white light emission devices, cell nuclei imaging, and information encryption. Our finding provides us an opportunity to design and construct more advanced multifunctional white luminescent materials based on metal-free carbon nanomaterials.Mixed 2'-F-riboguanosine and 2'-F-arabinoguanosine disubstitutions of a hybrid-type G-quadruplex are found to induce a refolding into two alternative structures with different types of V-loops upon positional exchange of the two G analogs. link3 While conformational preferences of the incorporated G surrogates fail to fully account for the observed rearrangements, additional hydrogen bonds with a fluorine acceptor are suggested to be critical determinants of the two distinct V-loop conformers imposing different tetrad polarities.No-wash detection of small molecules in real samples has been attracting attention in the field of sensors including electroanalytical biosensors. Based on the direct electrochemical oxidation of fluorene-9-bisphenol (BHPF) on a CoN nanoarray electrode, we developed a ratiometric molecularly imprinted polymeric electrochemical (MIP-EC) sensor to realize no-wash detection of BHPF in serum and tap water. The CoN nanoarray in situ grown on carbon cloth (CC) served as the working electrode, which could load the electroactive toluidine blue (TB) and be modified by the MIPs. As the MIP concentration on the modified electrode surface was increased, the amount of BHPF exposed on the electrode surface increased and the amount of exposed TB decreased. Thus, the values of ΔITB and ΔIBHPF decreased and increased, respectively, with an increasing amount of BHPF. Therefore, a ratiometric strategy was established by using the value of ΔITB/ΔIBHPF as the instruction response to realize detection of BHPF with high sensitivity and reliability.