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Correction Copper Paste Printed Paper Based Dual Band Antenna for Wearable Wireless Electronics
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Structure Activity Relationships and Biological Insights into PSMA 617 and Its Derivatives with Modified Lipophilic Linker Regions
No full textPSMA 617 is recognized as a benchmark ligand for prostate specific membrane antigen PSMA owing to its broad utilization in prostate cancer PCa targeted radionuclide therapy. In this study, the structure activity relationships SAR of PSMA 617 and two novel analogs featuring modified linkers were investigated. In compounds P17 and P18, the 2 naphthyl l Ala moiety was replaced with a less lipophilic 3 styryl l Ala moiety while the cyclohexyl ring in P18 was replaced with a phenyl group. The first ever crystal structure of the PSMA PSMA 617 complex reported here revealed a folded conformation of the PSMA 617 linker while for the PSMA P17 and PSMA P18 complexes, the extended orientations of the linkers revealed linker flexibility within the PSMA cavity, a change in binding that can be exploited for the structure guided design of PSMA targeting agents. Despite structural differences from PSMA 617, the analogs maintained high PSMA inhibition potency, cellular binding, and internalization. In vivo biodistribution studies revealed comparable tumor uptake across all three compounds with P18 displaying higher spleen accumulation, likely due to phenyl ring lipophilicity. These SAR findings provide a strategic framework for the rational design of PSMA ligands, paving the way for the development of next generation theranostic agents for PC
Nonreciprocal Spin Waves in Nanoscale Hybrid N el Bloch N el Domain Walls Detected by Scanning X Ray Microscopy in Perpendicular Magnetic Anisotropic Fe Gd Multilayers
Get PDFSpin wave nonreciprocity is crucial for signal processing in magnonic circuits. Domain walls DWs have been suggested as channels for nonreciprocal spin waves magnons with directional dependent properties. However, the experimental investigations are challenging due to the low damping magnetic material with DWs demanded and the nanoscale length scales involved. In this study, scanning transmission X ray microscopy STXM is used to examine coherently excited magnons when propagating in hybrid N el Bloch N el DWs in amorphous Fe Gd multilayers with perpendicular magnetic anisotropy PMA . Well ordered lattices of stripe domains and DWs are created through the integration of Cobalt nanowire arrays. Their width is measured to be amp; 948;DW 60 13 nm. Near 1 GHz magnons are detected with short wavelengths down to amp; 955; 281 44 nm which were channeled in the DWs. Consistent with micromagnetic simulations, the STXM data revealed a nonreciprocal magnon band structure inside the DWs. Bloch points are identified which disrupted the phase evolution of magnons and induced different amp; 955; adjacent to these topological defects. These observations provide direct evidence of nonreciprocal spin waves within hybrid N el Bloch N el DWs in PMA materials, serving as programmable waveguides in magnonic devices with directed information flo
Crystallographic Structure of Human Dihydroorotate Dehydrogenase in Complex with the Natural Product Inhibitor Lapachol
Get PDFDihydroorotate dehydrogenase DHODH is a key enzyme in the pyrimidine biosynthesis pathway, playing a critical role in cellular processes and offering therapeutic potential for antiviral, antineoplastic, and autoimmune treatments. Human DHODH HsDHODH utilizes ubiquinone as a second substrate, positioning its quinone binding site as a promising target for inhibitor development. Lapachol, a natural naphthoquinone, has gained prominence as a valuable natural product for the discovery of novel therapeutic agents, thanks to its wide range of biological activities. In this study, we present the first crystal structure of HsDHODH in complex with lapachol, providing valuable insights into the interactions between this natural product and the enzyme. The structure reveals key binding interactions that mediate lapachol s affinity for HsDHODH and validates previously proposed computational models. Complementary molecular dynamics simulations further highlight the stability of the complex and the importance of water mediated interactions in ligand binding. These findings enhance our understanding of how naphthoquinone derivatives, such as lapachol, interact with class 2 DHODHs, offering a foundation for the design of optimized inhibitors for therapeutic applications. By integration of structural and computational data, this study contributes to the rational design of novel HsDHODH inhibitors, paving the way for future exploration of lapachol and its derivatives in drug discover
Effect of the Ru concentration on the CO tolerance and the oxidizability of a composition spread PtRu Pt 111 near surface alloy
No full textWe prepared a Pt terminated PtRu near surface alloy with a lateral concentration gradient on Pt 111 . The near surface alloy is exposed to CO at 100 K or O2 at 600 K and subsequently investigated using synchrotron based high resolution X ray photoelectron spectroscopy. By moving the sample laterally under the focused X ray beam spot size amp; 8764;0.05 mm , we were able to study locally different alloy compositions under identical measurement conditions. With increasing subsurface Ru concentration, we observe a gradual decrease in the CO occupancy of Pt bridge sites, while the amount of on top adsorbed CO remains constant over the investigated compositional range. Oxidation of the alloy reveals a clear increase in the fraction of oxidized Ru atoms the RuOx amp; 8198; amp; 8198;Ru ratio with increasing Ru conten
Acyclic purine and pyrimidine nucleotide analogs as ecto 5 nucleotidase CD73 inhibitors
No full textEcto 5 amp; 8242; nucleotidase CD73 is a novel target in cancer immuno therapy. Its blockade prevents the formation of immunosuppressive and cancer promoting adenosine from AMP. Here, we report on the development of a series of small molecules that mimic adenine nucleotides, in which the ribose moiety was replaced by an alkyl chain. Its length was found to be crucial for potency. A crystal structure of the N6 disubstituted acyclic ADP analog 26 N6 benzyl,N6 methyladenine 9 yl pentyloxydiphosphonate in complex with human CD73 revealed that the flexible pentyl linker adopts to interdomain rotation angles differing by up to 18.5 . The most potent CD73 inhibitor of the present series was analog 27 N6 benzyl,N6 methyladenine 9 yl hexyloxydiphosphonate, PSB 24000 which exhibited submicromolar potency at human CD73 Ki 563 nM at soluble CD73; Ki 481 nM at membrane bound CD73 of triple negative breast cancer cells . Acyclic nucleotide analogs may be advantageous compared to the previously reported nucleotidic CD73 inhibitors due to their high chemical stability, and because less off target effects are to be expected. The structure activity relationships discovered in this study provide valuable insights which will be useful for the development of CD73 inhibitors as immunotherapeutic drug
In situ temperature calibration for high temperature XRD experiments in vacuum demonstrated on pristine and Nb doped TiO2 x thin films
Get PDFWe present an in situ temperature calibration technique for high temperature grazing incident X ray diffraction experiments conducted in high vacuum. Thermal lattice extension of a crystalline platinum thin film is used to calibrate the temperature in the sample to the control temperature measured by a thermocouple. This enables a precise thermal analysis of thin film crystal structures with an uncertainty of less than 10 K. Using this technique, we examine the crystallization behavior of pristine and niobium doped titanium dioxide thin films, deposited by direct current magnetron sputtering from metal ceramic composite targets. Crystallization onset temperatures and structural evolution were assessed for various target compositions and process conditions, revealing that increased metal content in the composite target tends to promote rutile phase formation during vacuum annealing. For the target containing 10wt niobium identified as the most promising for a transparent conductive oxide application an oxygen flow variation is evaluated. Results reveal significant differences in the crystal lattice depending on the oxygen flow during deposition. Introducing 0.2 oxygen to the argon process gas is sufficient to induce the formation of pure anatase phase during heat treatment, yielding a minimum resistivity of 1.2 m amp; 937; cm. Our findings highlight the crucial role of oxygen content in tailoring both the structural and opto electrical properties of titanium dioxide based thin films, providing essential insights for the definition of optimal process window
Tailored Crystallization Dynamics for Efficient and Stable DMSO Free Tin Perovskite Solar Cells
Get PDFTin perovskite solar cells are emerging as a sustainable lead free alternative in thin film photovoltaics. DMSO free processed tin perovskites are gaining interest due to the detrimental effects of DMSO on tin oxidation. However, replacing DMSO with other solvents remains challenging due to the accelerated crystallization dynamics in non DMSO systems. In this study, the crystallization process in a DMSO free solvent system is regulated by managing the transition from the sol gel phase to the solid film. Specifically, piperazine dihydriodide PDAI and 4 tert butylpyridine tBP are utilized to coordinately tune the colloidal chemistry through forming large pre nucleation clusters in perovskite ink, further, facilitating the film formation process. By combining tBP and PDAI, a controllable crystallization rate is achieved as evidenced by in situ photoluminescence PL measurement during spin coating. As a result, tin perovskite films show high crystallinity and improved microstructure. Devices treated with tBP PDAI exhibit a champion power conversion efficiency of 7.8 and excellent stability without observable degradation for over 3000 h stored in the N2 glovebox. These findings advance understanding and managing crystallization in DMSO free solvents processed tin perovskite solar cell
On the closure of thermally induced micro cracks in aluminum titanate ceramics
No full textAluminum Titanate AT refractory ceramics as some other ceramic composites are prone to microcracking, due to the thermal expansion anisotropy of AT and to the mismatch with the thermal expansion of the constituents. Such microcracks cause the room temperature Young s modulus to be only a fraction of that of the non microcracked material. As a function of temperature, the Young s modulus increases non linearly. Such increase suggests that microcracks close or even heal at high temperatures. Upon cooling, thermal stress accumulates again, and microcracks re open. This cycle is fully reversible. While confirming the hysteretic behavior of the Young s modulus, we observe that the amount of microcracks as determined by in situ Synchrotron X ray refraction radiography decreases linearly upon heating. The apparent mismatch between the Young s modulus and the microcrack content dependence on temperature is explained by a simple FEM model. Such model employs cohesive elements upon cooling, in order to estimate the amount of initial microcracks. On purpose, the model does not include healing upon heating and only allows crack closure. It predicts that crack closure continuously occurs upon heating, thereby qualitatively reproducing the nearly linear dependence of the X ray refraction signal. It is therefore concluded that the sudden and non linear increase of Young s modulus with temperature is mainly caused by crack healing. Such finding agrees with previous work and paves the road to a more systematic separation of crack closure and healing in flexible ceramic
Printing of tin perovskite solar cells via controlled crystallization
Get PDFThe urgent need for sustainable electricity has driven progress in solar technologies, with perovskite photovoltaics standing out as a top contender. However, the presence of toxic lead in current perovskite devices necessitates the exploration of alternative materials. This study addresses the challenges associated with tin perovskite fabrication and the industrial scale up of this lead free technology. It introduces a new approach to regulate the key process of crystallization, involving a combination of new additives and a gas pulse to trigger and subsequently control nucleation and crystal growth. In situ optical spectroscopy probed the crystallization and enabled the optimization of the printing conditions. Solar cells were fabricated with a power conversion efficiency of 5.38 for 0.1 cm2, 4.02 for 1 cm2 and 2.31 for 5 cm2 devices. They were tested under indoor lighting conditions and functioned at similar efficiency levels, thereby demonstrating the potential of this technology for commercial applications. Our new crystallization control method for printing Sn perovskites enabled the fabrication of the first Sn based solar cell via slot die coating, which is ideally suited for roll to roll manufacturing. This innovation opens new avenues for the development of fully printed lead free perovskite photovoltaics, contributing significantly to the advancement of sustainable energy technologie