The association between polymorphism and melting behavior was studied. The origin of the peaks that compose the multiple melting endotherm recorded at conventional heating rates was determined by combined wide-angle X-ray scattering, differential scanning calorimetry, fast scanning chip calorimetry, and polarized light optical microscopy measurements. The higher thermal stability of the α-crystals in comparison with the β-form was thus demonstrated.To address the low gas sensitivity of pristine graphene (Gr), chemical modification of Gr has been proved as a promising route. However, the existing chemical functionalization method imposes the utilization of toxic chemicals, increasing the safety risk. this website Herein, vitamin C (VC)-modified reduced graphene hydrogel (V-RGOH) is synthesized via a green and facile self-assembly process with the assistance of biocompatible VC molecules for high-performance NH3 and NO2 detection. The three-dimensional (3D) structured V-RGOH is highly sensitive to low-concentration NH3 and NO2 at room temperature. In comparison with those of the unmodified RGOH, the V-RGOH gas sensors display an order of magnitude higher sensitivity and much lower limit of detection, resulting from the enhanced interaction between VC and analytes. NH3 and NO2 with extremely low concentrations of 500 and 100 ppb are detected experimentally. Notably, imbedded microheaters are exploited to explore the temperature-dependent gas sensing properties, revealing the negative and positive impacts of temperature on the sensitivity and recovery speed, respectively. Notably, the V-RGOH sensor exhibits remarkable selectivity and linearity and a wide detection range. This work reveals the remarkable effects of chemical modification with biodegradable molecules and 3D structure design on improving the gas sensing performance of the Gr material.Progress in integrated nanophotonics has enabled large-scale programmable photonic integrated circuits (PICs) for general-purpose electronic-photonic systems on a chip. Relying on the weak, volatile thermo-optic, or electro-optic effects, such systems usually exhibit limited reconfigurability along with high-energy consumption and large footprints. These challenges can be addressed by resorting to chalcogenide phase-change materials (PCMs) such as Ge2Sb2Te5 (GST) that provide a substantial optical contrast in a self-holding fashion upon phase transitions. However, current PCM-based integrated photonic applications are limited to single devices or simple PICs because of the poor scalability of the optical or electrical self-heating actuation approaches. Thermal-conduction heating via external electrical heaters, instead, allows large-scale integration and large-area switching, but fast and energy-efficient electrical control is yet to be achieved. Here, we model electrical switching of GST-clad-integrated nanophotonic structures with graphene heaters based on the programmable GST-on-silicon platform. Thanks to the ultra-low heat capacity and high in-plane thermal conductivity of graphene, the proposed structures exhibit a high switching speed of ∼80 MHz and a high energy efficiency of 19.2 aJ/nm3 (6.6 aJ/nm3) for crystallization (amorphization) while achieving complete phase transitions to ensure strong attenuation (∼6.46 dB/μm) and optical phase (∼0.28 π/μm at 1550 nm) modulation. Compared with indium tin oxide and silicon p-i-n heaters, the structures with graphene heaters display two orders of magnitude higher figure of merits for heating and overall performance. Our work facilitates the analysis and understanding of the thermal-conduction heating-enabled phase transitions on PICs and supports the development of future large-scale PCM-based electronic-photonic systems.Metallic nanoclusters (NCs) have molecular-like structures and unique physical and chemical properties, making them an interesting new class of luminescent nanomaterials with various applications in chemical sensing, bioimaging, optoelectronics, light-emitting diodes (LEDs), etc. However, weak photoluminescence (PL) limits the practical applications of NCs. Herein, an effective and facile strategy of enhancing the PL of NCs was developed using Ag shell-isolated nanoparticle (Ag SHIN)-enhanced luminescence platforms with tuned SHINs shell thicknesses. 3D-FDTD theoretical calculations along with femtosecond transient absorption and fluorescence decay measurements were performed to elucidate the enhancement mechanisms. Maximum enhancements of up to 231-fold for the [Au7Ag8(C≡CtBu)12]+ cluster and 126-fold for DNA-templated Ag NCs (DNA-Ag NCs) were achieved. We evidenced a novel and versatile method of achieving large PL enhancements with NCs with potential for practical biosensing applications for identifying target DNA in ultrasensitive surface analysis.ConspectusProgrammed cell death (PCD) is fundamentally an indispensable process in all cellular activities, including cell development, wound healing, and immune surveillance of tumors (Galluzzi, L. et al. Cell Death Differ. 2018, 25, 486-541). Malfunctioning of PCD has been shown to be closely related to human diseases such as acute pancreatitis, neurodegenerative diseases, and diverse types of cancers. To date, multiple PCD processes have been discovered and the corresponding regulatory pathways have been elucidated. For example, apoptosis and autophagy are two PCD mechanisms that have been well studied by sophisticated models and probe toolkits. However, limited genetic and chemical tools for other types of PCD hamper the elucidation of their molecular mechanisms. Our group has been studying PCD using both function-oriented synthesis and chemical biology strategies, including the development of diverse chemical probes based on novel PCD modulators. For instance, in the development of downstream programmed ro-Diels-Alder cycloaddition of vinyl thioether and o-quinolinone quinone methide (TQ-ligation) to facilitate small molecule target identification. The combination of total synthesis and TQ-ligation enables subcellular imaging and identification of the cellular target of ainsliatrimer A to be PPARγ. In addition, TQ-ligation has been applied in the discovery of heat shock protein 90 (HSP90) as one of the functional target proteins for kongensin A. We also confirmed that kongensin A covalently attaches to Cys420 within HSP90 and demonstrated that kongensin A blocks the interaction between HSP90 and CDC37 and subsequently inhibits necroptosis. Our development of these diverse PCD modulators provides not only effective chemical tools for fundamental biomedical research, but also the foundation for drug discovery targeting important human diseases such as cancers and inflammation caused by malfunction of PCD.