Stereoselective Nanocarbon Imides Featuring 12-fold [5]helicenes

Despite the great progress in research on chiral molecular nanocarbons containing multiple helicenes, controlling the stereoselectivity is still a major challenge, especially when attempting to increase the number of helicene moieties. Herein, a novel molecular nanocarbon imides composed of C204 skeleton and eighteen imide groups was successfully synthesized via an inside–out ring closing strategy involving repeated Suzuki–Miyaura coupling for C–C bond formation and photocyclic aromatization. Because of the presence of quad–core twelvefold [5]helicenes, there are, in theory, more than one hundred stereoisomers. However, only one pair of stereoisomers with D3 symmetry was observed. Despite the large and rigid skeleton, the (3M,3M,3M,3M)+(3P,3P,3P,3P) enantiomers were successfully separated by chiral HPLC, and the chiroptical properties were investigated by CD spectroscopy.

Understanding and managing pain in the arthritic synovial joint: an update

Osteoarthritis is a very common cause of chronic pain in dogs and cats. Great progress has been made in the last 2–3 decades in unravelling the molecular mediators of joint pain. Now we are starting to see the benefits of this research in terms of new targets to block joint pain and new medicines reaching our pharmacy shelves. This review summarises the progress that has been made in understanding why and how arthritic joints cause pain. This will help readers understand novel medicines and provide insight into the others that might follow in the future.

Recent progress in pyrazinoacenes containing nonbenzenoid rings: synthesis, properties and applications

Azaacenes have emerged as a new and important class of organic materials, and their synthetic strategies and applications as organic semiconductors have gained great progress in recent years. Generally, adopting...

High throughput screening of promising lead-free inorganic halide double perovskites via first-principles calculations

Perovskite solar cells (PSCs) have been intensively investigated and made great progress due to their high photoelectric conversion efficiency and low production cost. However, poor stability and the toxicity of...

Dopant-Free Hole Transport Material Boosting the Performance of Inverted Methylamine-Free Perovskite Solar Cells

The great progress in power conversion efficiency (PCE) for methylamine (MA)-free inverted perovskite solar cells (PSCs) is inseparable from the rapid development of the hole transport layers (HTLs). We design...

Triptycene Derivatives: From Their Synthesis to Their Unique Properties

Since the first preparation of triptycene, great progress has been made with respect to its synthesis and the understanding of its properties. Interest in triptycene-based systems is intense; in recent years, advances in the synthetic methodology and properties of new triptycenes have been reported by researchers from various fields of science. Here, an account of these new developments is given and placed in reference to earlier pivotal works that underpin the field. First, we discuss new approaches to the synthesis of new triptycenes. Progress in the regioselective synthesis of sterically demanding systems is discussed. The application of triptycenes in catalysis is also presented. Next, progress in the understanding of the relations between triptycene structures and their properties is discussed. The unique properties of triptycenes in the liquid and solid states are elaborated. Unique interactions, which involve triptycene molecular scaffolds, are presented. Molecular interactions within a triptycene unit, as well as between triptycenes or triptycenes and other molecules, are also evaluated. In particular, the summary of the synthesis and useful features will be helpful to researchers who are using triptycenes as building blocks in the chemical and materials sciences.

The impact of oriental studies on the methods of writing the biography of the Prophet: أثر الدراسات الاستشراقية على مناهج كتابة السيرة النبوية

The study aimed at identify the most prominent similarities raised by orientalists against the Prophet’s biography, and to shed light on the most prominent Muslim scholars who responded to these suspicions. The study used the critical inductive approach, and the study reached many results, most notably: that intolerance and prejudice were dominating the writings of the ancient Orientalists due to their being affected by the spirit of religious fanaticism that was dominant and crystallized by the impact of the Crusades, and due to their weak knowledge of the Arabic language, and the lack of resources available to them. However, since the early modern times, the West has not been free of moderate thinkers who have praised Islam, but since the nineteenth century interest began to study and print Arabic manuscripts, and Orientalists began studying the history of the East for itself, following the scientific method that had made great progress in the West.

Emerging Nanoparticle Strategies for Modulating Tumor-Associated Macrophage Polarization

Immunotherapy has made great progress in recent years, yet the efficacy of solid tumors remains far less than expected. One of the main hurdles is to overcome the immune-suppressive tumor microenvironment (TME). Among all cells in TME, tumor-associated macrophages (TAMs) play pivotal roles because of their abundance, multifaceted interactions to adaptive and host immune systems, as well as their context-dependent plasticity. Underlying the highly plastic characteristic, lots of research interests are focused on repolarizing TAMs from M2-like pro-tumor phenotype towards M1-like antitumoral ones. Nanotechnology offers great opportunities for targeting and modulating TAM polarization to mount the therapeutic efficacy in cancer immunotherapy. Here, this mini-review highlights those emerging nano-approaches for TAM repolarization in the last three years.

Thermal Cloak: Theory, Experiment and Application

In the past two decades, owing to the development of metamaterials and the theoretical tools of transformation optics and the scattering cancellation method, a plethora of unprecedented functional devices, especially invisibility cloaks, have been experimentally demonstrated in various fields, e.g., electromagnetics, acoustics, and thermodynamics. Since the first thermal cloak was theoretically reported in 2008 and experimentally demonstrated in 2012, great progress has been made in both theory and experiment. In this review, we report the recent advances in thermal cloaks, including the theoretical designs, experimental realizations, and potential applications. The three areas are classified according to the different mechanisms of heat transfer, namely, thermal conduction, thermal convection, and thermal radiation. We also provide an outlook toward the challenges and future directions in this fascinating area.

Refraction of Flexural Waves by Ultra-broadband Achromatic Meta-slab with Wavelength-dependent Phase Shifts

Great progress has been made in modulating flexural waves by elastic metasurfaces. Most of the proposed elastic metasurfaces suffer from chromatic aberration, limited in a narrow bandwidth around the designed frequency. In this paper, overcoming the chromatic aberration, an ultra-broadband achromatic meta-slab (UAM) with subunits of gradient thickness is proposed to realize the refraction angle unchanged with the incident frequency. Based on the phase compensation principle, wavelength-dependent phase shifts for the UAM that realize achromaticity are obtained. In order to verify the effectiveness of the theoretical design, the transmitted wavefields are solved according to the phased array theory, and the results correspond with those obtained by the finite element (FE) simulations and experiments, which show that the refraction angle is unchanged for incident frequencies from 2 kHz to 8 kHz. Besides, the UAM is extended into a periodic meta-slab, and multifrequency achromaticity is realized. Our designed meta-slabs overcome the chromatic aberration by simple configurations, which have significance in the applications of vibration control, vibrational energy harvesting, and health monitoring.