Tonnesenchristiansen0961

Despite their impressive performance as a solar absorber, much remains unknown on the fundamental properties of metal halide perovskites (MHPs). Their polar nature in particular is an intense area of study, and the relative permittivity (εr) is a parameter widely used to quantify polarization over a range of different time scales. In this report, we have exploited frequency-dependent time-resolved microwave conductivity (TRMC) to study how εr values of a range of MHPs change as a function of time, upon optical illumination. Further characterization of charge carriers and polarizability are conducted by femtosecond transient absorption and stimulated Raman spectroscopy. We find that changes in εr are roughly proportional to photogenerated carrier density but decay with a shorter time constant than conductance, suggesting that the presence of charge carriers alone does not determine polarization.The development of highly efficient and durable earth-abundant hydrogen evolution reaction (HER) catalysts is crucial for the extensive implementation of the hydrogen economy. Members of the 2D MXenes family, particularly Mo2CT x , have recently been identified as promising HER catalysts. However, their inherent oxidative instability in air and aqueous electrolyte solutions is hindering their widespread use. Herein, we present a simple and scalable method to circumvent adventitious oxidation in Mo2CT x MXenes via in situ sulfidation to form a Mo2CT x /2H-MoS2 nanohybrid. The intimate epitaxial coupling at the Mo2CT x /2H-MoS2 nanohybrid interface afforded superior HER activities, requiring only 119 or 182 mV overpotential to yield -10 or -100 mA cm-2geom current densities, respectively. Density functional theory calculations reveal strongest interfacial adhesion was found within the nanohybrid structure as compared to the physisorbed nanohybrid, and the possibility to tune the HER overpotential through manipulating the extent of MXene sulfidation. Critically, the presence of 2H-MoS2 suppresses further oxidation of the MXene layer, enabling the nanohybrid to sustain industrially relevant current densities of over -450 mA cm-2geom with exceptional durability. Less than 30 mV overpotential degradation was observed after 10 continuous days of electrolysis at a fixed -10 mA cm-2geom current density or 100,000 successive cyclic voltammetry cycles. The exceptional HER durability of the Mo2CT x /2H-MoS2 nanohybrid presents a major step forward to realize practical implementation of MXenes as noble metal free catalysts for broad-based applications in water splitting and energy conversion.Recently, tin disulfide (SnS2) has become a hot research focus in various fields due to its advantages of a high transistor switching ratio, an adjustable band gap in visible light range, excellent Li storage performance, sensitive gas recognition, and efficient photocatalytic capability. However, at present, studies of its basic structure mostly stay on the regulation related to the number of layers. To maximize the value of SnS2 in the application design, this paper analyzes the angle-resolved polarized Raman spectra of SnS2 crystals grown under high-temperature sealing systems. Under the parallel scattering configuration test of both the sample basal plane and the cross plane, we observed that how the Raman scattering intensity of the two test planes varies with the polarization angle is different. Combining this experimental result with theory support allows us to reach a conclusion that the differential polarizability of the phonon vibration mode along the z-axis of the cross plane of SnS2 is proven to be the strongest. This finding is expected to provide favorable support for the application of structural regulation of SnS2 and work as a reference for studying other van der Waals layered materials with greater potential.Macrophages engulf "foreign" cells and particles, but phagocytosis of healthy cells and cancer cells is inhibited by expression of the ubiquitous membrane protein CD47 which binds SIRPα on macrophages to signal "self". Motivated by some clinical efficacy of anti-CD47 against liquid tumors and based on past studies of CD47-derived polypeptides on particles that inhibited phagocytosis of the particles, here we design soluble, multivalent peptides to bind and block SIRPα. Bivalent and tetravalent nano-Self peptides prove more potent (Keff ∼ 10 nM) than monovalent 8-mers as agonists for phagocytosis of antibody opsonized cells, including cancer cells. Multivalent peptides also outcompete soluble CD47 binding to human macrophages, consistent with SIRPα binding, and the peptides suppress phosphotyrosine in macrophages, consistent with inhibition of SIRPα's "self" signaling. Peptides exhibit minimal folding, but functionality suggests an induced fit into SIRPα's binding pocket. Pre-clinical studies in mice indicate safety, with no anemia that typifies clinical infusions of anti-CD47. Multivalent nano-Self peptides thus constitute an alternative approach to promoting phagocytosis of "self", including cancer cells targeted clinically.Novel low-pressure irrigation technologies have been widely adopted by farmers, allowing both reduced water and energy use. However, little is known about how the transition from legacy technologies affected water and energy use at the aquifer scale. Here, we examine the widespread adoption of low-energy precision application (LEPA) and related technologies across the Kansas High Plains Aquifer. We combine direct energy consumption and carbon emission estimates with life cycle assessment to calculate the energy and greenhouse gas (GHG) footprints of irrigation. We integrate detailed water use, irrigation type, and pump energy source data with aquifer water level and groundwater chemistry information to produce annual estimates of energy use and carbon emissions from 1994 to 2016. The rapid adoption of LEPA technologies did not slow pumping, but it reduced energy use by 19.2% and GHG emissions by 15.2%. Nevertheless, water level declines have offset energy efficiency gains because of LEPA adoption. Deeper water tables quadrupled the proportion of GHG emissions resulting from direct carbon emissions, offsetting the decarbonization of the regional electrical grid. We show that low-pressure irrigation technology adoption, absent policies that incentivize or mandate reduced water use, ultimately increases the energy and carbon footprints of irrigated agriculture.We reported herein a new 3D bio-MOF (NbU-12) using a pore space partition strategy MIL-88D was selected as a primary framework, and adenine connected two independent MIL-88D to form a self-interpenetrated structure. Because of this, the hexagonal channel in MIL-88D split into two small rectangular channels. Different from the reported series CPM-35 materials, NbU-12 simultaneously maximized the retention of open metal sites from MIL-88D and introduced a Watson-Crick face to the pore surface of NbU-12. Remarkably, NbU-12 exhibits an excellent selectivity performance toward C2H6/C2H4 and C2H6/CH4, which was proven by ideal adsorbed solution theory calculation and breakthrough experiments.Neutrophil extracellular traps (NETs) consist of DNA released by terminally stimulated neutrophils. They fine-tune inflammation, kill pathogens, activate macrophages, contribute to airway mucus obstruction in cystic fibrosis, and facilitate tumor metastasis after dormancy. Neutrophil proteases such as elastase (NE) and cathepsin G (CG) attach to NETs and contribute to the diverse immune outcome. However, because of the lack of suitable tools, little spatiotemporal information on protease activities on NETs is available in a pathophysiological context to date. Here, we present H-NE and H-CG, two FRET-based reporters armed with a DNA minor groove binder, which monitor DNA-bound NE and CG activity, respectively. The probes revealed that only NE maintains its catalytic ability when localized to DNA. Further, we demonstrated elevated protease activity within the extracellular DNA of sputum from cystic fibrosis patients. Finally, H-NE showed NE activity at single-cell and free DNA resolution within mouse lung slices, a difficult to achieve task with available substrate-based reporters.The architecturally symmetrical and synthetically challenging marine natural products lomaiviticins A and B present alluring synthetic targets due to their molecular complexity, potent antitumor properties, and natural scarcity. Herein, we report the total synthesis of the fully glycosylated monomeric unit of lomaiviticin A, monolomaiviticin A. The retrosynthetically derived synthetic strategy relied on an intramolecular palladium-catalyzed coupling reaction to complete the tetracyclic aglycon scaffold and gold-promoted glycosylations to install the synthetically challenging α- and β-glycoside moieties of the target molecule. This accomplishment paves a path for the eventual total synthesis of lomaiviticins A and B and opens opportunities for biological investigations within this family of compounds.A method for the fabrication of flexible electrical circuits on polyaramid substrates is presented based on laser-induced carbonization followed by copper electroplating. 4-Methylumbelliferone mouse Locally carbonized flexible sheets of polyaramid (Nomex), by laser radiation, create rough and highly porous microstructures that show a higher degree of graphitization than thermally carbonized Nomex sheets. The found recipe for laser-induced carbonization creates conductivities of up to ∼45 S cm-1, thereby exceeding that observed for thermally pyrolyzed materials (∼38 S cm-1) and laser carbon derived from Kapton using the same laser wavelength (∼35 S cm-1). The electrical conductivity of the carbonized tracks was further improved by electroplating with copper. To demonstrate the electrical performance, fabricated circuits were tested and improvement of the sheet resistance was determined. Copper films exhibit antimicrobial activity and were used to fabricate customized flexible antibacterial coatings. The integration of laser carbonization and electroplating technologies in a polyaramid substrate points to the development of customized circuit designs for smart textiles operating in high-temperature environments.The accumulation and deposition of fibrillar aggregates of α-synuclein (α-syn) into Lewy bodies are the major hallmarks of Parkinson's disease (PD) for which there is no cure yet. Disrupting preformed α-syn fibrils is considered one of the rational therapeutic strategies to combat PD. Experimental studies reported that epigallocatechin gallate (EGCG), a polyphenol extracted from green tea, can disrupt α-syn fibrils into benign amorphous aggregates. However, the molecular mechanism of action is poorly understood. Herein, we performed molecular dynamics simulations on a newly released Greek-key-like α-syn fibril with or without EGCG to investigate the influence of EGCG on α-syn fibril. Our simulations show that EGCG disrupts the local β-sheet structure, E46-K80 salt-bridge crucial for the stabilization of the Greek-key-like structure, and hydrophobic interactions stabilizing the inter-protofibril interface and destabilizes the global structure of the α-syn fibril. Interaction analyses reveal that hydrophobic and hydrogen-bonding interactions between EGCG and α-syn fibrils play important roles in the destabilization of the fibril.