Latest ArticlesTemperature plays a crucial role in regulating polymorphism in supramolecular polymers. Understanding the mechanism behind temperature-dependent supramolecular polymorphism is crucial as it provides an opportunity to tailor polymorphs for specific properties and applications. In this study, we present our findings on a naphthalimide-substituted benzene-1,3,5-tricarboxamide derivative, R-Nap-1, which exhibits two distinct polymerization pathways at varying temperatures. At 313 K, polymerization results in the formation of an M-chiral polymorph, whereas at 253 K, a P-chiral polymorph is formed. Both polymorphs are notably stable, remaining unchanged for over six months under ambient conditions. Theoretical calculations and experimental investigations allowed us to elucidate the mechanisms underlying these polymorphic transformations. The formation of the M-chiral polymorph at 313 K is attributed to the nucleation and growth of R-Nap-1 monomers once their concentration surpasses a critical threshold. Conversely, at lower temperatures (e.g., 253 K), the monomers undergo facile transformation into dimers due to a lower energy barrier and reduced Gibbs energy compared to the monomeric state. Subsequently, these dimers undergo nucleation-elongation to form the P-chiral polymorph when their concentration exceeds the critical polymerization concentration. The stability and lack of interconversion between the two polymorphs can be attributed to their close thermodynamic stabilities, as evidenced by variable-temperature CD spectra and DFT calculations. These findings highlight the importance of accurate temperature control in supramolecular polymerization processes, making a significant contribution to the understanding of supramolecular polymorphism, thus advancing the field of supramolecular chemistry.
The homochiral compounds play an important role in human health and pharmaceutical industry. Currently, the chromatographic enantioseparation has become one of the most effective and practical approach to obtain pure enantiomers. Herein, the exploration of advanced materials, using as chromatographic chiral stationary phases for racemic separation, has attracted great attention. Thanks to their high enantioselectivity and controllable synthesis, the emerging chiral metal-organic frameworks (CMOFs) have been widely studied as the stationary phase in chromatographic technology. In this review, we will summarize the principles of synthetic strategies and mechanism of chiral microenvironment. In particular, the recent progress and research hotspot of CMOFs regarding as the chiral stationary phases in gas chromatography (GC), high-performance liquid chromatography (HPLC), and capillary electrochromatography (CEC), are elucidated systematically according to the published work. Last but not the least, we also highlight the challenges and perspectives of rational design of CMOFs, as well as their corresponding racemic separation. We envision that the review will provide a further understanding of CMOFs and facilitate the development of chromatographic enantioselective applications.
Artificial synapses are essential building blocks for neuromorphic electronics. Here, solid polymer electrolyte-gated artificial synapses (EGASs) were fabricated using ITO fibers as channels, which possess an ultra-high sensitivity of 5 mV and a long-term memory time exceeding 3 min. Notably, digitally printed ITO-fiber arrays exhibit an ultra-high transmittance of approximately 99.67%. Biological synaptic plasticity, such as excitatory postsynaptic current, paired-pulse facilitation, spike frequency-dependent plasticity, and synaptic potentiation and depression, were successfully mimicked using the EGASs. Based on the synaptic properties of the EGASs, an artificial neural network was constructed to perform supervised learning using the Fashion-MNIST dataset, achieving high pattern recognition rate (82.39%) due to the linear and symmetric synaptic plasticity. This work provides insights into high-sensitivity artificial synapses for future neuromorphic computing.
Viral epidemics pose a serious threat to global public health, making it essential to explore virus-host interactions for uncovering the pathogenesis of viral diseases and developing effective antiviral strategies. Traditional in vitro cell infection models struggle to replicate physiological microenvironment, while animal infection models may encounter obstacles such as species gap, high-cost, and ethical issues. Additionally, potential heterogeneous infection outcomes are usually inaccessible by population-based experiments. Microfluidics, as an emerging interdisciplinary platform, has proven to be a powerful tool for inquiring virus-host interactions. In this review, conventional virological methods were introduced first and remarkable advantages of microfluidics in viral cell biology were highlighted. Next, the in-depth applications of microfluidics in analyzing heterogeneity of virus-host interplays, dynamic monitoring of events related to viral life cycle, and modeling of viral infectious diseases were fully elaborated from the perspective of single-cell chip, multi-cell culture chip and organ-on-a-chip (organ chip). Finally, the opportunities and challenges in developing robust microfluidic methods for virology were discussed. Overall, this review aims to provide an overview of microfluidic-based research on virus-host interaction and promote multidisciplinary collaborations for better understanding and responding to viral threats.
Under "green architecture" principles, electrochromic smart windows are employed to adjust optical transmittance and indoor temperature, yet their high costs limit the wide application. Here, an electrochromic window is driven by a redox flow battery (RFB), where TOC and deposition layers are no longer needed. The transmittance of the electrochromic window is modulated by the state of oxidation (SOC) of aqueous posolyte Fe(phen)3Cl2, which is coupled with BTMAP-Vi negolyte in RFB. Under optimized conditions, average CE, VE, and EE reach 93.25%, 92.61%, and 86.35% for RFB with a capacity fading rate of 1.57% per cycle. 88.66% optical modulation and 9.36 cm2/C coloration efficiency are achieved in the electrochromic process, and 72.34% optical modulation is maintained after 12000 s. Essentially, the indoor temperature declines 3 ℃ for posolyte with 100% SOC when compared with the control experiment using circulating water for a model house. This means minimum electricity of 0.0185 kWh is saved when using an air conditioner to cool a 100 m3 house, which corresponds to declined CO2 emission (COE) of 0.0185 kg. This work provides a novel and cost-efficient strategy for modulating indoor comfort via electrochromic windows driven by RFB.
As the main organ of gas exchange, the lungs are susceptible to various exogenous attacks, and pneumonia is one of the major inflammatory diseases that threaten human health. Generally, pneumonia is a disease that occurs in the alveoli and respiratory bronchioles induced by pathogens and further causes local and systemic inflammatory responses. The development of pneumonia can bring various serious complications, including lung abscess, sepsis, meningitis, brain damage and hearing loss. Over the past few decades, the mortality rate of pneumonia patients has remained high. While lung cancer is another lung-related malignant tumors worldwide, with a low 5 year survival rate. Exploring the mechanisms of their occurrence and interaction between pneumonia and lung cancer is a challenging and meaningful task. The abnormalities of lipid droplets (LDs) polarity have been found strongly accompanied by many diseases, especially cancer, inflammation, and metabolic diseases. However, their exact role is not yet clear. Hence, it is significant to develop a novel detection method to observe the polarity changes of LDs, which would help to reveal the development process of diseases pneumonia and lung cancer. In this work, a new polarity-sensitive LDs-targeted near-infrared probe BFZ up to 712 nm was designed, according to the intramolecular charge transfer mechanism, which displayed high fluorescence intensity in low polarity while showing decreased fluorescence intensity in high-polarity conditions with a significant redshift. The BFZ was successfully applied to the change of LDs polarity in lipopolysaccharide (LPS)-stimulated A549 cells, and a mouse model of lung inflammation. It also tells the polarity differences between normal and tumor cells and between normal and tumor tissues. Moreover, the correlations between pneumonia and polarity changes were observed through the imaging experiments, which may provide an insightful method for the early diagnosis of pneumonia and lung cancer.
β-Amino sulfides hold significant biological importance, motivating the development of several methods for sulfenylamination of alkenes. However, these methods often involve a three-component system with limited alkene substrate range. In this study, we present a pioneering two-component approach utilizing readily accessible sulfenamides as efficient difunctionalization reagents. Key to its success is the careful selection of a suitable photosensitizer, which enables precise modulation of sulfenamides by promoting unprecedented energy transfer rather than traditional single-electron oxidation. This novel strategy leads to the concurrent formation of N- and S-radical species, ensuring high regioselectivity for both electron-neutral and electron-deficient alkenes. As a result, a wide range of valuable β-amino sulfides, including those with congested amine groups, can be readily synthesized. These findings highlight the potential of this method for the efficient synthesis of diverse functionalized β-amino sulfides.
Antibiotics present in surface water have detrimental effects on both human health and the ecosystem. Additionally, they pose a threat to the effectiveness of biological water treatment processes. In this study, a visible photocatalytic system with BiOCl/g-C3N4 heterojunction was developed to remove sulfonamide antibiotic sulfamerazine (SMZ) in water. The removal rate reached 92.77% under visible light irradiation for 80 min. This photocatalyst remained active after 5 cycles of experiments and maintained a relatively stable removal rate of SMZ of over 80%. The ESR tests indicate that the main active species in this photocatalytic system were h+ and •O2−. The enhanced photocatalytic efficiency was mainly ascribed to the formation of a built-in electric field between BiOCl and g-C3N4 through the carrier transport mechanism of the S-scheme heterojunction. This heterojunction facilitated the photogenerated carrier shift and segregation, and improved the interfacial charge transfer efficiency, as confirmed by photoelectrochemical test and Density functional theory (DFT) calculations. The HPLC-QTOF-MS/MS and DFT analysis revealed possible degradation pathways of SMZ may involve deamination, hydroxylation, SO2 extrusion and bond breaking. This novel BiOCl/g-C3N4 heterojunction has proven to be essential for efficient visible-light photocatalysis.
Host-guest recognition-based macrocycle in macrocycle to form "Russian doll" assemblies remains an interesting topic in supramolecular chemistry. Herein, a macrocycle-in-macrocycle assembly was studied using cucurbit[10]uril (Q[10]) and the smallest cucurbituril-like macrocycle (TD[4]). X-ray crystal structure analysis revealed that TD[4] was encapsulated in the cavity of Q[10] to form a 1:1 complex. Importantly, competitive guest studies suggested that TD[4] had the highest binding constant with the Q[10] host among the guests used, including Q[5], Me8TD[4], and amantadine molecules in water. Our results provided a new cucurbituril-based Russian-doll structure containing both the largest and smallest cavities of the cucurbiturils, which expanded the family of molecular Russian dolls.
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