Harrelltherkelsen7890

The weak electron-hole binding within the BPPs and the resulting polaron delocalization are key factors for efficient charge separation at nearly zero driving force. Our work provides useful insight into how to further improve the power conversion efficiency in OPVs.We report a high-yield synthesis of gold (Au) nanosheets with tunable size and surface morphology in the aqueous phase. In particular, crumpled and flat Au nanosheets with a thickness of ∼10 nm could be selectively produced in high purity when the reaction was conducted at room temperature and in an ice-water bath, respectively. Unlike Au nanoplates/nanoprisms in the form of well-defined triangles or hexagons documented in previous studies, the current products exhibit random in-plane branches or holes, together with wavy edges. Strong absorbance in the NIR region was observed for all the Au nanosheet products. When serving as electrocatalysts for the ethanol oxidation reaction, the current products exhibited an enhanced activity and operation stability, as compared to quasi-spherical counterparts.The formation of nanoscale phases at grain boundaries in polycrystalline materials has attracted much attention, since it offers a route toward targeted and controlled design of interface properties. However, understanding structure-property relationships at these complex interfacial defects is hampered by the great challenge of accurately determining their atomic structure. Here, we combine advanced electron microscopy together with ab initio random structure searching to determine the atomic structure of an experimentally fabricated Σ13 (221) [11̅0] grain boundary in rutile TiO2. Through careful analysis of the atomic structure and complementary electron energy-loss spectroscopy analysis we identify the existence of a unique nanoscale phase at the grain boundary with striking similarities to the bulk anatase crystal structure. Our results show a path to embed nanoscale anatase into rutile TiO2 and showcase how the atomic structure of even complex internal interfaces can be accurately determined using a combined theoretical and experimental approach.Human milk (HM) is the primary source of nutrients and bioactive components that supports the growth and development of infants. However, the proteins present in human milk may change depending on the period of lactation. In this light, the objective of the present study was to evaluate the effect of lactation period on HM utilizing a data-independent acquisition (DIA) approach to identify the differences in HM whey protein proteomes. As part of the study, whey proteins of January, February, and June in human milk were studied. The results identified a total of 1563 proteins in HM whey proteins of which 114 groups were subunits of differentially expressed proteins as revealed by cluster analysis. Protein expression was observed to be affected by the period of lactation with expression levels of plasminogen, thrombospondin-1, and tenascin higher during January, keratin, type I cytoskeletal 9 highest in February, and transcobalamin-1 highest in June. The results of this study contribute to expand our understanding of the human whey proteome but also provide strong evidence for the nutritional difference of HM during different lactation periods.Novel indazole and benzimidazole analogues were designed and synthesized as tubulin inhibitors with potent antiproliferative activities. Among them, compound 12b exhibited the strongest inhibitory effects on the growth of cancer cells with an average IC50 value of 50 nM, slightly better than colchicine. 12b exhibited nearly equal potency against both, a paclitaxel-resistant cancer cell line (A2780/T, IC50 = 9.7 nM) and the corresponding parental cell line (A2780S, IC50 = 6.2 nM), thus effectively overcoming paclitaxel resistance in vitro. The crystal structure of 12b in complex with tubulin was solved to 2.45 Å resolution by X-ray crystallography, and its direct binding was confirmed to the colchicine site. Furthermore, 12b displayed significant in vivo antitumor efficacy in a melanoma tumor model with tumor growth inhibition rates of 78.70% (15 mg/kg) and 84.32% (30 mg/kg). Collectively, this work shows that 12b is a promising lead compound deserving further investigation as a potential anticancer agent.We compute the primary charge separation step in the homodimeric reaction center (RC) of Heliobacterium modesticaldum from first principles. Using time-dependent density functional theory with the optimally tuned range-separated hybrid functional ωPBE, we calculate the excitations of a system comprising the special pair, the adjacent accessory bacteriochlorophylls, and the most relevant parts of the surrounding protein environment. The structure of the excitation spectrum can be rationalized from coupling of the individual bacteriochlorophyll pigments similar to molecular J- and H-aggregates. We find excited states corresponding to forward-charge transfer along the individual branches of the RC of H. modesticaldum. In the spectrum, these are located at an energy between the coupled Qy and Qx transitions. With ab initio Born-Oppenheimer molecular dynamics simulations, we reveal the influence of thermal vibrations on the excited states. The results show that the energy gap between the coupled Qy and the forward-charge transfer excitations is ∼0.4 eV, which we consider to conflict with the concept of a direct transfer mechanism. Our calculations, however, reveal a certain spectral overlap of the forward-charge transfer and the coupled Qx excitations. The reliability and robustness of the results are demonstrated by several numerical tests.The overall efficiency of photosynthetic energy conversion depends both on photochemical and excitation energy transfer processes from extended light-harvesting antenna networks. Bioactive Compound Library cost Understanding the trade-offs between increase in the antenna cross section and bandwidth and photochemical conversion efficiency is of central importance both from a biological perspective and for the design of biomimetic artificial photosynthetic complexes. Here, we employ two-dimensional electronic spectroscopy to spectrally resolve the excitation energy transfer dynamics and directly correlate them with the initial site of excitation in photosystem I-light harvesting complex I (PSI-LHCI) supercomplex of land plants, which has both a large antenna dimension and a wide optical bandwidth extending to energies lower than the peak of the reaction center chlorophylls. Upon preferential excitation of the low-energy chlorophylls (red forms), the average relaxation time in the bulk supercomplex increases by a factor of 2-3 with respect to unselective excitation at higher photon energies.