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We describe the synthesis and photophysical characterization of differently substituted planar chiral analogues of PRODAN based on a [2.2]paracyclophane scaffold. This experimental and theoretical study highlights that the (chir)optical properties of the new "phane" compounds, which incorporate an electron-withdrawing propionyl moiety and an electron-donating dimethylamino group at their para or pseudo-para positions, strongly depend on their substitution patterns. selleck chemicals llc In particular, for this series of molecules, a more pronounced solvatochromism and clear chiroptical behaviors are observed when the two substituents are placed on the two rings of the pCp core in a non-"co-planar" arrangement (pseudo-para derivative). This observation may help design new pCp-based luminophores with finely tuned photophysical properties.The electrodissolution of Au(111) in anaerobic cupric/ammonia/thiosulfate solutions, typical of a non-equilibrium dissipative system, was investigated via in situ electrochemical atomic force microscopy. At a specific initial concentration ratio of aqueous ammonia to cupric ions, the pit number and average pit area increase autocatalytically, while the pit depth increases monotonically during dissolution. A further increase in this initial concentration ratio leads to oscillatory dynamics in the pit number and average pit area while the pit depth fluctuates between one and two atoms. Mechanistic analysis indicates that alternation between formation and dissolution of a sulfur film results in periodic pitting, which produces gold dissolution layer by layer. This work presents a new dissolution mode, i.e., periodic layer dissolution generated by oscillatory pitting processes in addition to a pitting mode with a continually increasing depth, and the use of high initial concentration ratios of ammonia to cupric ion to accelerate the elimination of passivating sulfur film for Au dissolution.Bromodomain-containing protein 4 (BRD4) is an attractive epigenetic target in human cancers. Inhibiting the phosphorylation of BRD4 by casein kinase 2 (CK2) is a potential strategy to overcome drug resistance in cancer therapy. The present study describes the synthesis of multiple BRD4-CK2 dual inhibitors based on rational drug design, structure-activity relationship, and in vitro and in vivo evaluations, and 44e was identified to possess potent and balanced activities against BRD4 (IC50 = 180 nM) and CK2 (IC50 = 230 nM). In vitro experiments show that 44e could inhibit the proliferation and induce apoptosis and autophagy-associated cell death of MDA-MB-231 and MDA-MB-468 cells. In two in vivo xenograft mouse models, 44e displays potent anticancer activity without obvious toxicities. Taken together, we successfully synthesized the first highly effective BRD4-CK2 dual inhibitor, which is expected to be an attractive therapeutic strategy for triple-negative breast cancer (TNBC).X-ray absorption spectroscopy is a powerful probe of local electronic and nuclear structures, providing insights into chemical processes. The theoretical prediction and interpretation of metal L-edge X-ray absorption spectra are complicated by both relativistic effects, including spin-orbit coupling and the multiconfigurational nature of the states involved. This work details an exact two-component multireference restricted active space (RAS) configuration interaction scheme that uses an exact two-component state-averaged complete active space self-consistent-field method, which includes the spin-orbit coupling in a variational manner, for the accurate description of the electronic structure before using a RAS configuration interaction method to describe the core excited states of the X-ray spectrum. Benchmark calculations are presented for a series of iron-containing complexes, with results showing key features of the spectrum being reproduced, including ligand-to-metal charge transfer and shake-up excitations.Most of the cathodic photoelectrochemical (PEC) bioassays rely on electron accepting molecules for signal stimuli; unfortunately, the performances of which are still undesirable. New signal transduction strategies are still highly expected for the further development of cathodic photoelectrochemistry as a potentially competitive method. This work represents a new concept of invoked cathodic photoelectrochemistry by a spontaneously formed electron transporter for innovative operation of the sensing strategy. Specifically, the hexacyanoferrate(II) in solution easily self-coordinated with CuO nanomaterials and formed electron transporting copper hexacyanoferrate (CuHCF) on the surface, which endowed improved carrier separation for presenting augmented photocurrent readout. Exemplified by the T4 polynucleotide kinase (T4 PNK) and its inhibitors as targets, a homogenous cathodic PEC biosensing platform was achieved with the distinctive merits of label-free, immobilization-free, and split-mode readout. The mechanism revealed here provided a totally different perspective for signal transduction in cathodic photoelectrochemistry. Hopefully, it may stimulate more interests in the design and construction of semiconductor/transporter counterparts for exquisite operation of photocathodic bioanalysis.Industry relocation under globalization has altered the origins and strength of emission sources of many air pollutants. We develop global emission inventories of polycyclic aromatic hydrocarbons (PAHs) embodied in the production and consumption of goods and services. We implement these inventories within a global atmospheric transport model and simulate spatial-temporal changes in atmospheric concentrations of benzo[α]pyrene (BaP), the most toxic congener in unsubstituted PAHs, and depositions across the Arctic subject to global trade and industry relocation. We show that interregional trade and industry relocation dramatically reduce the atmospheric levels and deposition of BaP in the Arctic. The most significant BaP decline occurs in the European and North American Arctic regions due to attenuated sources in the two well-developed continents proximate to the polar region induced by the relocation of high-PAH pollution industries to many developing countries far from the Arctic. Although BaP emissions embodied in industry relocations in China, India, and South and Southeast Asia resulted in increased BaP contamination in the Asian Arctic, such increases in pollution are minor compared to significant BaP reductions occurring in the European and North American Arctic regions. We find that "North-to-South" industry transfer could reduce trade-related BaP contamination by 60% in the Arctic.Ru(II)- and Cu(I)-based photosensitizers featuring the recently developed biipo ligand (16H-benzo-[4',5']-isoquinolino-[2',1',1,2]-imidazo-[4,5-f]-[1,10]-phenanthrolin-16-one) were comprehensively investigated by X-ray crystallography, electrochemistry, and especially several time-resolved spectroscopic methods covering all time scales from femto- to milliseconds. The analysis of the experimental results is supported by density functional theory (DFT) calculations. The biipo ligand consists of a coordinating 1,10-phenanthroline moiety fused with a 1,8-naphthalimide unit, which results in an extended π-system with an incorporated electron acceptor moiety. In a previous study, it was shown that this ligand enabled a Ru(II) complex that is an efficient singlet oxygen producer and of potential use for other light-driven applications due to its long emission lifetime. The goal of our here presented research is to provide a full spectroscopic picture of the processes that follow optical excitation. Interestingly, the Ru(II) and Cu(I) complexes differ in their characteristics even though the lowest electronically excited states involve in both cases the biipo ligand. The combined spectroscopic results indicate that an emissive 3MLCT state and a rather dark 3LC state are populated, each to some extent. For the Cu(I) complex, most of the excited population ends up in the 3LC state with an extraordinary lifetime of 439 μs in the solid state at 20 K, while a significant population of the 3MLCT state causes luminescence for the Ru(II) complex. Hence, there is a balance between these two states, which can be tuned by altering the metal center or even by thermal energy, as suggested by the temperature-dependent experiments.Numerous emerging applications in modern society require humidity sensors that are not only sensitive and specific but also durable and intelligent. However, conventional humidity sensors do not have all of these simultaneously because they require very different or even contradictory design principles. Here, inspired by camel noses, we develop a porous zwitterionic capacitive humidity sensor. Relying on the synergistic effect of a porous structure and good chemical and thermal stabilities of hygroscopic zwitterions, this sensor simultaneously exhibits high sensitivity, discriminability, excellent durability, and, in particular, the highest respond speed among reported capacitive humidity sensors, with demonstrated applications in the fast discrimination between fresh, stale, and dry leaves, high-resolution touchless human-machine interactive input devices, and the real-time monitoring humidity level of a hot industrial exhaust. More importantly, this sensor exhibits typical synapse behaviors such as paired-pulse facilitation due to the strong binding interactions between water and zwitterions. This leads to learning and forgetting features with a tunable memory, thus giving the sensor artificial intelligence and enabling the location of water sources. This work offers a general design principle expected to be applied to develop other high-performance biochemical sensors and the next-generation intelligent sensors with much broader applications.For aptamer selection, the random-region length of an ssDNA library was generally taken in a relatively arbitrary fashion, which may lead to failure for unsuitable target binding. Herein, we coupled high-efficiency capillary electrophoresis (CE)-SELEX and high-throughput sequencing (HTS) to investigate the influences of random-region length. First, one round of selection against programmed cell death-ligand 1 (PD-L1) was performed using ssDNA libraries with random-region lengths of 15, 30, 40, and 60 nt, respectively. A good correlation was observed between candidates' random-region lengths and dissociation constant (Kd), in which the longer sequences presented higher affinity, and the picked Seq 60-1 after one round notably presented a similar affinity toward a reported aptamer through eight rounds. Molecular dynamics (MD) simulation suggested, for PD-L1, the long sequence could supply more noncovalent bonds including hydrogen bonds, electrostatic interactions, and hydrophobic interactions to form a stable protein/aptamer complex. Besides, four other proteins with selective binding performances validated the importance of random-region length. To further investigate how random-region length affects the selection efficiency, a mixed library with random-region lengths ranging from 10 to 50 nt was employed for six rounds of selection against Piezo2. Sequence variations were tracked by HTS, showing the preferential evolution and PCR uncertainty with even higher impact were the main causes. This study suggested random-region length plays a crucial factor, and a mixed library with different random-region sequences can be a worthy choice for increasing the speed of high-affinity aptamer selection. Moreover, the PCR process should be given particular attention in aptamer selection.
Read More: https://www.selleckchem.com/products/euk-134.html
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