Currently, there are still obstacles to rationally designing the ligand fields to activate rare-earth (RE) elements with satisfactory intrinsic electrocatalytic reactivity. Herein, axial coordination strategies and nanostructure design are applied for the construction of La single atoms (La-Cl SAs/NHPC) with satisfactory oxygen reduction reaction (ORR) activity. The nontrivial LaNCl motifs configuration and the hierarchical porous carbon substrate that facilitates maximized metal atom utilization ensure high half-wave potential (0.
View Article and Find Full Text PDFThe ligand effect in alloy catalysts is one of the decisive parameters of the catalytic performance. However, the strong interrelation between the ligand effect and the geometric effect of the active atom and its neighbors as well as the systematic alteration of the microenvironment of the active site makes the active mechanism unclear. Herein, PtTm, PtYb, and PtLu with a cubic crystal system (-3) were selected.
View Article and Find Full Text PDFAstraZeneca chemists have been using the AI retrosynthesis tool AiZynth for three years. In this article, we present seven examples of how medicinal chemists using AiZynth positively impacted their drug discovery programmes. These programmes run the gamut from early-stage hit confirmation to late-stage route optimisation efforts.
View Article and Find Full Text PDFCesium lead halide (CsPbX, X = Br, Cl, and I) nanocrystals (NCs) are widely concerned and applied in many fields due to the excellent photoelectric performance. However, the toxicity of Pb and the loss of luminescence in water limit its application in vivo. A stable perovskite nanomaterial with good bioimaging properties is developed by incorporating europium (Eu) in CsPbX NCs followed with the surface coating of silica (SiO) shell (CsPbX:Eu@SiO).
View Article and Find Full Text PDFRare earth (RE) elements possess electronic configurations that can provide additional pathways for tailoring the electronic structures of active elements through alloying, making it an important area of exploration in electrocatalysis. However, the large negative redox potential between RE and Pt has hindered the development of RE nanoalloys. In this study, a solid-phase synthesis strategy was employed to synthesize ternary PtIrSc nanoparticles (NPs).
View Article and Find Full Text PDFBackground: Air pollution and severe weather conditions can adversely affect cardiovascular disease emergencies. Nevertheless, it remains unclear whether air pollutants and low ambient temperature can trigger the occurrence of acute aortic dissection (AAD) in cold regions.
Methods: We applied a retrospective analysis to assess the short-term effects of air pollution and ambient temperature on the occurrence of AAD in Harbin, China.
Rare earth (RE) intermetallic nanoparticles (NPs) are significant for fundamental explorations and promising for practical applications in electrocatalysis. However, they are difficult to synthesize because of the unusually low reduction potential and extremely high oxygen affinity of RE metal-oxygen bonds. Herein, intermetallic IrSm NPs were firstly synthesized on graphene as a superior acidic oxygen evolution reaction (OER) catalyst.
View Article and Find Full Text PDFFor current single-atom catalysts (SACs), modulating the coordination environments of rare-earth (RE) single atoms with complex electronic orbital and flexible chemical states is still limited. Herein, cerium (Ce) SAs supported on a P, S, and N co-doped hollow carbon substrate (Ce SAs/PSNC) for the oxygen reduction reaction (ORR) are reported. The as-prepared Ce SAs/PSNC possesses a half-wave potential of 0.
View Article and Find Full Text PDFRare earth elements play an important role in various fields, which has attracted increasing interest from the scientific community. Meanwhile, single-atom catalysts show huge advantages in many aspects compared with traditional nanomaterials due to their 100% atomic utilization efficiency. Thus, the combination of the two concepts has yielded an efficient way to realize the high-value utilization of rare earth elements.
View Article and Find Full Text PDFIn the pharmaceutical industry, amorphous solid dispersion can be utilized to enhance the solubility, hence bioavailability, of poorly solubility active pharmaceutical ingredients owing to the higher free energy of the amorphous state. Measuring the concentration, size and spatial distribution of crystalline API particles that may be present in amorphous solid dispersions (ASD) is critical to understanding product performance and developing improved formulations. In this study X-Ray Microscopy (XRM) was used to nondestructively measure these attributes in ASDs.
View Article and Find Full Text PDFDiabetic cardiomyopathy (DCM) is a condition associated with significant structural changes including cardiac tissue necrosis, localized fibrosis, and cardiomyocyte hypertrophy. This study sought to assess whether and how FBXL10 can attenuate DCM using a rat streptozotocin (STZ)-induced DCM model system. In the current study, we found that FBXL10 expression was significantly decreased in diabetic rat hearts.
View Article and Find Full Text PDFThe mycelial polysaccharide from Catathelasma ventricosum (mCVP-1S) was found to be a heteropolysaccharide with an average size of 230kDa composed mainly of β-glucopyranosyl residues. The selenylation of mCVP-1S, performed using an HNO-NaSeO method, produced a series of selenized mCVP-1Ss (SemCVP-1Ss). Varying the reaction time, temperature and NaSeO dosage altered the yield and selenium content of the SemCVP-1Ss.
View Article and Find Full Text PDFAcoustic illusion cloaks that create illusion effects by changing the scattered wave have many potential applications in a variety of scenarios. However, the experimental realization of generating three-dimensional (3D) acoustic illusions under detection of broadband signals still remains challenging despite the paramount importance for practical applications. Here we report the design and experimental demonstration of a 3D broadband cloak that can effectively manipulate the scattered field to generate the desired illusion effect near curved boundaries.
View Article and Find Full Text PDFDevelopment of magnetic encapsulated microbubble agents that can integrate multiple diagnostic and therapeutic functions is a key focus in both biomedical engineering and nanotechnology and one which will have far-reaching impact on medical diagnosis and therapies. However, properly designing multifunctional agents that can satisfy particular diagnostic/therapeutic requirements has been recognized as rather challenging, because there is a lack of comprehensive understanding of how the integration of magnetic nanoparticles to microbubble encapsulating shells affects their mechanical properties and dynamic performance in ultrasound imaging and drug delivery. Here, a multifunctional imaging contrast and in-situ gene/drug delivery agent was synthesized by coupling super paramagnetic iron oxide nanoparticles (SPIOs) into albumin-shelled microbubbles.
View Article and Find Full Text PDFQuantitative assessment of the lung microstructure using standard stereological methods such as volume fractions of tissue, alveolar surface area, or number of alveoli, are essential for understanding the state of normal and diseased lung. These measures are traditionally obtained from histological sections of the lung tissue, a process that ultimately destroys the three-dimensional (3-D) anatomy of the tissue. In comparison, a novel X-ray-based imaging method that allows nondestructive sectioning and imaging of fixed lungs at multiple resolutions can overcome this limitation.
View Article and Find Full Text PDFEstablishing the 3D architecture and morphometry of the intact pulmonary acinus is an essential step toward a more complete understanding of the relationship of lung structure and function. We combined a special fixation method with a unique volumetric nondestructive imaging technique and image processing tools to separate individual acini in the mouse lung. Interior scans of the parenchyma at a resolution of 2 µm enabled the reconstruction and quantitative study of whole acini by image analysis and stereologic methods, yielding data characterizing the 3D morphometry of the pulmonary acinus.
View Article and Find Full Text PDFA general and versatile biomimetic approach to synthesize water dispersible and functionalizable upconverting nanoparticles (UCNPs) for selective imaging of live cancer cells is reported. The approach involves coating the surface of UCNPs with a monolayer of phospholipids containing different functional groups, allowing for conjugation of many molecules for a wide range of applications in fields such as bioinspired nanoassembly, biosensing, and bio-medicine.
View Article and Find Full Text PDFX-ray computed tomography is used to reconstruct the 3D structure of a polymeric photonic crystal. The reconstructed structure is compared to the structure predicted by a model. This analysis provides means to better understand deformations that occur during holographic fabrication of photonic crystals.
View Article and Find Full Text PDFDimension and structure of extracellular matrix surfaces have powerful influences on cell shape, adhesion, and gene expression. Here we show that natural tooth root topographies induce integrin-mediated extracellular matrix signaling cascades in tandem with cell elongation and polarization to generate physiological periodontium-like tissues. In this study we replanted surface topography instructed periodontal progenitors into rat alveolar bone sockets for 8 and 16 weeks, resulting in complete reattachment of tooth roots to the surrounding alveolar bone with a periodontal fiber apparatus closely matching physiological controls along the entire root surface.
View Article and Find Full Text PDFWe present the first experimental demonstration of focusing ultrasound waves through a flat acoustic metamaterial lens composed of a planar network of subwavelength Helmholtz resonators. We observed a tight focus of half-wavelength in width at 60.5 kHz by imaging a point source.
View Article and Find Full Text PDFZhonghua Xin Xue Guan Bing Za Zhi
January 2007
Objective: Conflicting results exist on the therapeutic effects of percutaneous myocardial laser revascularization (PMR) in patients with refractory angina pectoris. This study assessed the effects of PMR on myocardial innervation and perfusion in patients with refractory angina pectoris.
Methods: Patients with refractory angina unsuitable for standard revascularization treatment (PTI and CABG) were randomly divided into medication plus PMR (PMR, n = 17) and medication group (M, n = 13).
The constructive interference of surface plasmon polaritons (SPP) launched by nanometric holes allows us to focus SPP into a spot of high near-field intensity having subwavelength width. Near-field scanning optical microscopy is used to map the local SPP intensity. The resulting SPP patterns and their polarization dependence are accurately described in model calculations based on a dipolar model for the SPP emission at each hole.
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