•Mechanism of an unusual type of wave resonance.•Universality of the local resonance.•Demonstration of the existence of the resonance.•Perfect wave insulation under the resonance.
We argue that a ...collection of evanescent waves inside a short expansion of a waveguide can react as an inertial reactance for an incoming wave and its interplay with the compliant effect inherent to the expansion forms the mechanism of the resonance that results in perfect insulation at a lower frequency than the cutoff of the expansion. We show that this type of resonance is ubiquitous, existing in general classic waves like acoustic and water waves traveling through locally expanded waveguides. The theoretical predictions are demonstrated both by numeric simulations and experiments.
The nanomechanics of cells have been proven to play important roles in regulating cell behaviors. However, conventional measurement of cell nanomechanics that is processed on uniform surfaces lacks ...the control of cell morphology, which is reported to significantly influence the cell nanomechanics. This study prepares the micropatterned surfaces using photolithographic micropatterning of photoreactive poly(vinyl alcohol) on cell‐culture polystyrene plates to provide controllable and reproducible cell morphology. The nanomechanics of osteoblasts (NHOst), mesenchymal stem cells (MSCs), and osteosarcoma cell line (MG‐63) are compared on micropatterns. Cell stiffness increases with increase of spreading area due to the ordering of cytoskeleton. Disrupting F‐actin assembly reduces cell stiffness. Meanwhile, cell spreading area influences the expression of phosphoezrin that affects cell surface roughness. Rough membrane is accompanied with high non‐specific adhesion force and migration rate. The influence of spreading area on cancer cell nanomechanics is not as evident as that of normal cells indicating cancer cells behave less dependently on their microenvironment compared to normal cells. The findings of this study suggest that the nanomechanical differences between normal and cancer cells can be used as a biomarker to enhance the diagnosis of cancers. The use of micropatterns should be very useful to compare the nanomechanics of cells.
Nanomechanics of micropatterned osteosarcoma microenvironment cells are investigated using atomic force microscopy. Cancer cells are less stiff but more invasive than their normal counterparts when they have same morphology. The decrease of spreading area leads to decrease of elasticity but increase of surface roughness and non‐specific adhesion force. These further influence cell migration potential, which is important especially for cancer cells.
Gene transfection has broad applications in bioengineering and biomedical fields. Although many gene carrier materials and transfection methods have been developed, it remains unclear how cell ...morphology including cell spreading and elongation affects gene transfection. In this study, human bone marrow-derived mesenchymal stem cells (hMSCs) were cultured on micropatterns and transfected with cationic pAcGFP1-N1 plasmid complexes. The relationship between the cell morphology of hMSCs and gene transfection was investigated using micropatterning techniques. Spreading and elongation of hMSCs were precisely controlled by micropatterned surfaces. The results showed that well-spread and elongated hMSCs had high transfection efficiency. Analysis of the uptake of exogenous genes and DNA synthesis activity indicated that the well-spread and elongated cell morphology promoted gene transfection through enhanced uptake of the cationic complexes and accelerated DNA synthesis. The results should provide useful information for understanding of cell morphology on gene transfection and development of efficient gene transfection methods.
Despite the remarkable rise in the efficiency of perovskite-based solar cells, the stress-induced intrinsic instability of perovskite active layers is widely identified as a critical hurdle for ...upcoming commercialization. Herein, a long-alkyl-chain anionic surfactant additive is introduced to chemically ameliorate the perovskite crystallization kinetics via surface segregation and micellization, and physically construct a glue-like scaffold to eliminate the residual stresses. As a result, benefiting from the reduced defects, suppressed ion migration and improved energy level alignment, the corresponding unencapsulated perovskite single-junction and perovskite/silicon tandem devices exhibit impressive operational stability with 85.7% and 93.6% of their performance after 3000 h and 450 h at maximum power point tracking under continuous light illumination, providing one of the best stabilities to date under similar test conditions, respectively.
Transcranial photobiomodulation (tPBM) has been considered a safe and effective brain stimulation modality being able to enhance cerebral oxygenation and neurocognitive function. To better understand ...the underlying neurophysiological effects of tPBM in the human brain, we utilized a 111-channel functional near infrared spectroscopy (fNIRS) system to map cerebral hemodynamic responses over the whole head to 8-min tPBM with 1,064-nm laser given on the forehead of 19 healthy participants. Instead of analyzing broad-frequency hemodynamic signals (0–0.2 Hz), we investigated frequency-specific effects of tPBM on three infra-slow oscillation (ISO) components consisting of endogenic, neurogenic, and myogenic vasomotions. Significant changes induced by tPBM in spectral power of oxygenated hemoglobin concentration (ΔHbO), functional connectivity (FC), and global network metrics at each of the three ISO frequency bands were identified and mapped topographically for frequency-specific comparisons. Our novel findings revealed that tPBM significantly increased endogenic ΔHbO powers over the right frontopolar area near the stimulation site. Also, we demonstrated that tPBM enabled significant enhancements of endogenic and myogenic FC across cortical regions as well as of several global network metrics. These findings were consistent with recent reports and met the expectation that myogenic oscillation is highly associated with endothelial activity, which is stimulated by tPBM-evoked nitric oxide (NO) release.
A new zirconium-based metal-organic polyhedron was successfully synthesized and it possesses considerable reversible iodine sorption performance.
Display omitted
•A tetrahedral Zr-MOP-1 was ...successfully synthesized under solvothermal condition.•Zr-MOP-1 possesses considerable reversible iodine sorption performance.•The adsorbed I− and I3− in Zr-MOP-1 were identified by crystallographic analyses.
A new zirconium-based metal-organic polyhedron (Zr-MOP-1) was successfully synthesized from Bis(cyclopentadienyl)zirconium dichloride and 2,5-pyridinedicarboxylic acid under solvothermal condition. It was characterized by single-crystal X-ray diffraction, powder X-ray diffraction, thermogravimetric analysis and infrared spectroscopy. Four trinuclear zirconocene building blocks as well as six linear carboxylate ligands give rise to its tetrahedral configuration. Interestingly, Zr-MOP-1 possesses considerable reversible iodine sorption performance in organic phase featuring an optimal adsorption capacity of 283 mg g−1. The related kinetics absorption and desorption process were fully explored in detail by multiple complementary experiments and the adsorbed iodine species (I− and I3−) in Zr-MOP-1 had been further identified through crystallographic analyses. This work provides new possibilities for developing new and functional zirconium-based molecular cages materials.
Abstract
Inspired by the structures of virus capsids, chemists have long pursued the synthesis of their artificial molecular counterparts through self–assembly. Building nanoscale hierarchical ...structures to simulate double-shell virus capsids is believed to be a daunting challenge in supramolecular chemistry. Here, we report a double-shell cage wherein two independent metal–organic polyhedra featuring Platonic and Archimedean solids are nested together. The inner (3.2 nm) and outer (3.3 nm) shells do not follow the traditional “small vs. large” pattern, but are basically of the same size. Furthermore, the assembly of the inner and outer shells is based on supramolecular recognition, a behavior analogous to the assembly principle found in double-shell viruses. These two unique nested characteristics provide a new model for Matryoshka–type assemblies. The inner cage can be isolated individually and proves to be a potential molecular receptor to selectively trap guest molecules.
Discriminant functions DP1-1 vs. DP1-2 (Fig.) separate most of the scheelite data from various mineralized systems. In general, scheelites from the mineralized groups have high total contents of ...trace elements that partition onto the Ca sites (Mo, Sr, Nd, REE, Y, Ta, Pb).
Display omitted
•Scheelites from the quartz-vein and greisen W(Sn), porphyry, skarn and orogenic Au ore systems have high total contents of trace elements that partition onto the Ca sites (Mo, Sr, Nd, REE, Y, Ta, Pb).•Scheelites form greisen W-Sn polymetallic deposits tend to have more restricted Sr compositions and Eu anomaly than those from quartz-vein W-Sn, as well as relatively high Gd, Tb, Dy and Ho contents which coincides with wide alteration which indicating intense fluid-rock interaction during mineralization.•Through the three discrimination steps, the scheelites from many ore deposits can be readily separated from the other groups. Scheelites geochemistry with Discriminant Projection Analysis (DPA) are efficient methods for mineral exploration.
Scheelite is a widespread accessory tungstate mineral that contains a variety of trace elements. Scheelites from the major types of magmatic-hydrothermal mineral deposits (86 deposits, including quartz-vein and greisen, porphyry, skarn and orogenic Au deposits) have been collected and analyzed using laser ablation-inductively coupled plasma mass spectrometry (3270 data, including 584 analyses). Discriminant analysis using Mo, Sr, Nb, La, Ce, Eu, Dy, Yb, Y, Ta, Pb, (Ce/Yb)N, (La/Sm)N, (Gd/Yb)N, Eu anomaly, Ce anomaly, (La/Yb)N, LREE/HREE, Y/Ho and Mo + Sr + Nd + rare-earth elements (REE) + Y + Ta + Pb reveals that scheelites from different mineral deposits can be distinguished. Scheelites from quartz-vein and greisen deposits have high total contents of trace elements that partition onto the Ca sites (Mo, Sr, Nd, REE, Y, Ta, Pb). Scheelites from the porphyry W ± Cu ± Mo deposits, which have been studied in this work, are characterized by low Mo and positive Eu than scheelites from porphyry Cu ± Mo deposits. This indicates that large scale tungsten deposits are related to reduced hydrothermal fluids, in contrast to the oxidized fluids associated with porphyry Cu ± Mo deposits. Scheelites from skarn W ± Sn ± Mo deposits typically exhibit a wide range of Y/Ho ratio and a higher sum of the elements Mo, Sr, Nd, REE, Y, Ta, and Pb compared to that from the skarn Cu ± Mo ± W deposits, indicating that increased amount of fluorine probably leads to large-scale W, Mo, and Sn mineralization during magmatic-hydrothermal processes. Scheelites from the greisen W-Sn polymetallic deposits tend to have more restricted Sr compositions and Eu anomalies than those from the quartz vein W-Sn deposits, as well as relatively high Gd, Tb, Dy and Ho contents, which coincide with extensive hydrothermal alteration, indicating intense fluid-rock interaction during mineralization. Using Discriminant projection analysis (DPA), scheelites from many ore deposits can be readily separated from each other. This study demonstrates that heavy-mineral scheelite grains collected during regional geochemical surveys are effective in identifying specific types of buried mineral deposits in potential mineralization area. Scheelite geochemistry with DPA provides an effective guidance for mineral exploration.
The use of immunotherapy has achieved great advances in the treatment of cancer. Macrophages play a pivotal role in the immune defense system, serving both as phagocytes (removal of pathogens and ...cancer cells) and as antigen‐presenting cells (activation of T cells). However, research regarding tumor immunotherapy is mainly focused on the adaptive immune system. The usefulness of innate immune cells (eg, macrophages) in the treatment of cancer has not been extensively investigated. Recent advances in synthetic biology and the increasing understanding of the cluster of differentiation 47/signal regulatory protein alpha (CD47/SIRPɑ) axis may provide new opportunities for the clinical application of engineered macrophages. The CD47/SIRPɑ axis is a major known pathway, repressing phagocytosis and activation of macrophages. In this article, we summarize the currently available evidence regarding the CD47/SIRPɑ axis, and immunotherapies based on blockage. In addition, we propose cell therapy strategies based on macrophage engineering.
The immunotherapy has achieved great progress in cancer treatment. In the article, we review current knowledge about cluster of differentiation 47/signal regulatory protein alpha (CD47/SIRPɑ) pathway and immunotherapies based on blocking CD47/SIRPɑ axis, and we also propose a cell therapy strategy to engineer macrophage to attack cancer cells in the future
The concentration dependence of the conductivity of ion exchange membranes (IEMs), as well as other transport properties, has been well explained by the contemporary two-phase model (Zabolotsky et ...al., 1993) considering a gel phase and an inter-gel phase filled with electroneutral solution. Here, this two-phase model has been adopted and first applied in electrolytes containing mixed counter-ions to investigate the correlation between the membrane ionic conductivity and its microstructure. For three representative commercial cation exchange membranes (CEMs), the total membrane conductivity (κT) when in equilibrium with mixed MgSO4 + Na2SO4 and H2SO4 + Na2SO4 electrolytes could be well predicted with the experimental composition of counter-ions in the gel and inter-gel phase, as well as the counter-ion mobility in the gel phase when the membrane is in a single electrolyte. It is found that the volume fraction of the inter-gel phase (f2) has little impact on the predicted results. The accuracy of the model can be largely improved by calculating the inter-gel phase conductivity (κin) with the ionic mobility being the same as that in the external solution (obtained via simulation in the OLI Studio), rather than simply as equivalent to the conductivity of the external solution (κs). Moreover, a nonlinear correlation between the CEMs’ conductivities and the counter-ion composition in the gel phase is observed in the mixed MgSO4 + Na2SO4 solution, as well as for the Nafion117 membrane in the presence of sulfuric acid. For CEMs in mixed MgSO4 + Na2SO4 electrolytes, the calculated conductivity values considering the interaction parameter σ, similar to the Kohlrausch’s law, are closer to the experimental ones. Overall, this work provides new insights into membrane conductivity with mixed counter-ions and testifies to the applicability of the contemporary two-phase model.
PDF
