Dempseynilsson9162

These new NM ICLs will allow for the further characterization of the biological responses to this important class of antitumor agents.Potassium isotopic analysis is arousing increasing interest, not only in geochemistry, but also in biomedicine. However, real-life applications are still hindered by the lack of robustness of the methods used. In this work, a novel and robust method for high-precision K isotopic analysis of geological and biological samples was developed, based on the use of a multicollector ICP-mass spectrometer providing a mass resolving power of 15,000 (extra-high resolution mode, XHR). After evaluation of different measurement conditions, i.e., hot vs cold plasma conditions, standard-type vs jet-type sampling cone, and high resolution (HR) vs XHR, a combination of hot plasma conditions, use of the high-transmission jet-type sampling cone, and the XHR mode allowed for high-precision and interference-free K isotopic analysis. Potassium signal monitoring was performed in the ArH+ interference-free 0.006-0.007 amu wide peak shoulder using the XHR mode. The within-run, short-term external, and long-term external precisions for the δ41K value were 0.02‰ (2se, N = 50), 0.03‰ (2SD, N = 7), and 0.06‰ (2SD, N = 163), respectively. A two-stage chromatographic procedure was developed for the isolation of K from both geological and biological samples, and potential matrix effects affecting the K isotope ratio were systematically evaluated. The method was first applied to geological reference materials (RMs) for validation purposes, and the K isotope ratio results were in good agreement with those previously reported. Subsequently, a series of biological RMs, including serum, whole blood, cerebrospinal fluid, bovine muscle, and lobster hepatopancreas, were characterized for their K isotopic composition.Microfluidic bioanalytical platforms are driving discoveries from synthetic biology to the health sciences. In this work, we present a platform for in vivo live-cell imaging and automated species detection in mixed cyanobacterial biofilms from cold climate environments. Using a multimodal microscope with custom optics applied to a chip with six parallel growth channels, we monitored biofilm dynamics via continuous imaging at natural irradiance levels. Machine learning algorithms were applied to the collected hyperspectral images for automatic segmentation of mixed-species biofilms into individual species of cyanobacteria with similar filamentous morphology. The coupling of microfluidic technology with modern multimodal imaging and computer vision systems provides a versatile platform for the study of cause-and-effect scenarios of cyanobacterial biofilms, which are important elements of many ecosystems, including lakes and rivers of the polar regions.The spin crossover compound Fe(H2B(pyrazole)(pyridylpyrazole))2 was investigated in detail on Ag(111) with scanning tunneling microscopy (STM). A large fraction of the deposited molecules condenses into gridlike tetramers. Two molecules of each tetramer may be converted between two states by current injection. We attribute this effect to a spin transition. This interpretation is supported by control experiments on the analogous, magnetically passive Zn compound that forms virtually identical tetramers but exhibits no switching. The switching yields were studied for various electron energies, and the resulting values exceed those reported from other SCO systems by 2 orders of magnitude. PTC596 mw The other two molecules of a tetramer were immutable. However, they may be used as contacts for current injection that leads to conversion of one of their neighbors. This "remote" switching is fairly efficient with yields reduced by only one to two orders of magnitude compared to direct excitation of a switchable molecule. We present a model of the tetramer structure that reproduces key observations from the experiments. In particular, sterical blocking prevents spin crossover of two molecules of a tetramer. Density functional theory calculations show that the model indeed represents a minimum energy structure. They also reproduce STM images and corroborate a remote-switching mechanism that is based on electron transfer between molecules.Organ-on-chip systems are promising new in vitro research tools in medical, pharmaceutical, and biological research. Their main benefit, compared to standard cell culture platforms, lies in the improved in vivo resemblance of the cell culture environment. A critical aspect of these systems is the ability to monitor both the cell culture conditions and biological responses of the cultured cells, such as proliferation and differentiation rates, release of signaling molecules, and metabolic activity. Today, this is mostly done using microscopy techniques and off-chip analytical techniques and assays. Integrating in situ analysis methods on-chip enables improved time resolution, continuous measurements, and a faster read-out; hence, more information can be obtained from the developed organ and disease models. Integrated electrical, electrochemical, and optical sensors have been developed and used for chemical analysis in lab-on-a-chip systems for many years, and recently some of these sensing principles have started to find use in organ-on-chip systems as well. This perspective review describes the basic sensing principles, sensor fabrication, and sensor integration in organ-on-chip systems. The review also presents the current state of the art of integrated sensors and discusses future potential. We bring a technological perspective, with the aim of introducing in-line sensing and its promise to advance organ-on-chip systems and the challenges that lie in the integration to researchers without expertise in sensor technology.Development of efficient solid catalysts for catalytic conversion of dilute CO2 is of extreme importance for carbon capture and utilization. We report the synthesis of bifunctional polymers co-incorporated with porphyrin-Zn as Lewis acid sites and Br- as nucleophiles for the cycloaddition of dilute CO2 with epoxides in this work. It was found that the Br-/Zn ratio has a volcano relation with the activity of bifunctional polymers in a cycloaddition reaction, indicating the synergy effect between Lewis acid sites and nucleophiles. The turnover frequency (TOF) of the bifunctional polymer is more than four-fold that of the physical mixture of tetrabutylammonium bromide and porphyrin-Zn-incorporated polymer, implying the enhanced cooperation between Br- and porphyrin-Zn in the polymer network. The bifunctional polymer with optimized Br-/Zn afforded 99% conversion, 99% selectivity, and a TOF as high as 12,000 h-1 for the cycloaddition of CO2 and propylene oxide, which is among the most active solid catalysts ever reported.