Herein we describe a mild method for the dual C(sp3)−H bond functionalization of saturated nitrogen‐containing heterocycles through a sequential visible‐light photocatalyzed dehydrogenation/2+2 ...cycloaddition procedure. As a complementary approach to the well‐established use of iminium ion and α‐amino radical intermediates, the elusive cyclic enamine intermediates were effectively generated by photoredox catalysis under mild conditions and efficiently captured by acetylene esters to form a wide array of bicyclic amino acid derivatives, thus enabling the simultaneous functionalization of two vicinal C(sp3)−H bonds.
A great team: A dual C(sp3)−H bond functionalization strategy was developed by merging dehydrogenation under visible‐light photocatalysis with a 2+2 cycloaddition reaction in a sequential process. This method enabled cyclobutene rings to be fused to various saturated nitrogen‐containing heterocycles to produce a series of cyclic amino acid derivatives.
•Characterization, mechanisms, and synthesis summary of self-healing hydrogels are described.•Covalent and non-covalent interaction mechanisms to obtain self-healing hydrogels are ...discussed.•Properties and applications of self-healing hydrogels such as mechanical, biocompatibility, degradability, adhesive, anti-infection, antioxidant, and hemostatic, etc. are reviewed.
Self-healing hydrogels' remarkable dependability and enduring stability have made them stand out as extremely promising soft materials for tissue engineering. The mechanism behind their self-healing capabilities relies on reversible physical or chemical interactions that result in cross-linking. Researchers are designing and developing self-healing hydrogels with captivating characteristics such as impressive biocompatibility, responsiveness, conductivity, and mechanical and antibacterial properties. These desirable characteristics are tailored to meet the specific requirements of practical applications. This comprehensive review focuses on the latest progress in making hydrogels with self-healing properties and employing them to help heal wounds. Synthesis strategies may occasionally employ a combination of reversible physical or chemical cross-linking processes. Furthermore, the diverse therapies of these hydrogels encompass adhesive properties, wound-healing capabilities, drug-delivery systems, and more. Lastly, this review addresses self-healing hydrogels and tackles and explores future development prospects. The potential for these materials to revolutionize the area of tissue engineering is discussed, emphasizing their capability to overcome obstacles and pave the way for enhanced medical treatments.
Aiming at the construction of novel platform for efficient light harvesting, the precise synthesis of a new family of AIEgen‐branched rotaxane dendrimers was successful realized from an ...AIEgen‐functionalized 2rotaxane through a controllable divergent approach. In the resultant AIE macromolecules, up to twenty‐one AIEgens located at the tails of each branches, thus making them the first successful example of AIEgen‐branched dendrimers. Attributed to the solvent‐induced switching feature of the rotaxane branches, the integrated rotaxane dendrimers displayed interesting dynamic feature upon the aggregation‐induced emission (AIE) process. Moreover, novel artificial light‐harvesting systems were further constructed based on these AIEgen‐branched rotaxane dendrimers, which revealed impressive generation‐dependent photocatalytic performances for both photooxidation reaction and aerobic cross‐dehydrogenative coupling (CDC) reaction.
A novel artificial light‐harvesting system based on AIEgen‐branched rotaxane dendrimers has been successfully constructed which displayed impressive generation‐dependent photocatalytic performances for both photooxidation reaction and aerobic cross‐dehydrogenative coupling reaction.
Lithium–sulfur (Li–S) batteries have been recognized as promising substitutes for current energy‐storage technologies owing to their exceptional advantage in energy density. The main challenge in ...developing highly efficient and long‐life Li–S batteries is simultaneously suppressing the shuttle effect and improving the redox kinetics. Polar host materials have desirable chemisorptive properties to localize the mobile polysulfide intermediates; however, the role of their electrical conductivity in the redox kinetics of subsequent electrochemical reactions is not fully understood. Conductive polar titanium carbides (TiC) are shown to increase the intrinsic activity towards liquid–liquid polysulfide interconversion and liquid–solid precipitation of lithium sulfides more than non‐polar carbon and semiconducting titanium dioxides. The enhanced electrochemical kinetics on a polar conductor guided the design of novel hybrid host materials of TiC nanoparticles grown within a porous graphene framework (TiC@G). With a high sulfur loading of 3.5 mg cm−2, the TiC@G/sulfur composite cathode exhibited a substantially enhanced electrochemical performance.
Li–S batteries: The electrochemical reaction kinetics of reversible polysulfide interconversion and Li2S nucleation/precipitation are substantially enhanced on the conductive and polar surface of titanium carbide, guiding the design of advanced host materials towards high‐energy and stable Li–S batteries.
Abstract
Frustrated magnets hold the promise of material realizations of exotic phases of quantum matter, but direct comparisons of unbiased model calculations with experimental measurements remain ...very challenging. Here we design and implement a protocol of employing many-body computation methodologies for accurate model calculations—of both equilibrium and dynamical properties—for a frustrated rare-earth magnet TmMgGaO
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(TMGO), which explains the corresponding experimental findings. Our results confirm TMGO is an ideal realization of triangular-lattice Ising model with an intrinsic transverse field. The magnetic order of TMGO is predicted to melt through two successive Kosterlitz–Thouless (KT) phase transitions, with a floating KT phase in between. The dynamical spectra calculated suggest remnant images of a vanishing magnetic stripe order that represent vortex–antivortex pairs, resembling rotons in a superfluid helium film. TMGO therefore constitutes a rare quantum magnet for realizing KT physics, and we further propose experimental detection of its intriguing properties.
Cisplatin-based adjuvant chemotherapy is the standard of care for patients with resected stage II–IIIA non-small-cell lung cancer (NSCLC). RADIANT and SELECT trial data suggest patients with ...EGFR-mutant stage IB–IIIA resected NSCLC could benefit from adjuvant EGFR tyrosine kinase inhibitor treatment. We aimed to compare the efficacy of adjuvant gefitinib versus vinorelbine plus cisplatin in patients with completely resected EGFR-mutant stage II–IIIA (N1–N2) NSCLC.
We did a randomised, open-label, phase 3 trial at 27 centres in China. We enrolled patients aged 18–75 years with completely resected (R0), stage II–IIIA (N1–N2), EGFR-mutant (exon 19 deletion or exon 21 Leu858Arg) NSCLC. Patients were stratified by N stage and EGFR mutation status and randomised (1:1) by Pocock and Simon minimisation with a random element to either gefitinib (250 mg once daily) for 24 months or intravenous vinorelbine (25 mg/m2 on days 1 and 8) plus intravenous cisplatin (75 mg/m2 on day 1) every 3 weeks for four cycles. The primary endpoint was disease-free survival in the intention-to-treat population, which comprised all randomised patients; the safety population included all randomised patients who received at least one dose of study medication. Enrolment to the study is closed but survival follow-up is ongoing. The study is registered with ClinicalTrials.gov, number NCT01405079.
Between Sept 19, 2011, and April 24, 2014, 483 patients were screened and 222 patients were randomised, 111 to gefitinib and 111 to vinorelbine plus cisplatin. Median follow-up was 36·5 months (IQR 23·8–44·8). Median disease-free survival was significantly longer with gefitinib (28·7 months 95% CI 24·9–32·5) than with vinorelbine plus cisplatin (18·0 months 13·6–22·3; hazard ratio HR 0·60, 95% CI 0·42–0·87; p=0·0054). In the safety population, the most commonly reported grade 3 or worse adverse events in the gefitinib group (n=106) were raised alanine aminotransferase and asparate aminotransferase (two 2% patients with each event vs none with vinorelbine plus cisplatin). In the vinorelbine plus cisplatin group (n=87), the most frequently reported grade 3 or worse adverse events were neutropenia (30 34% patients vs none with gefitinib), leucopenia (14 16% vs none), and vomiting (eight 9% vs none). Serious adverse events were reported for seven (7%) patients who received gefitinib and 20 (23%) patients who received vinorelbine plus cisplatin. No interstitial lung disease was noted with gefitinib. No deaths were treatment related.
Adjuvant gefitinib led to significantly longer disease-free survival compared with that for vinorelbine plus cisplatin in patients with completely resected stage II–IIIA (N1–N2) EGFR-mutant NSCLC. Based on the superior disease-free survival, reduced toxicity, and improved quality of life, adjuvant gefitinib could be a potential treatment option compared with adjuvant chemotherapy in these patients. However, the duration of benefit with gefitinib after 24 months might be limited and overall survival data are not yet mature.
Guangdong Provincial Key Laboratory of Lung Cancer Translational Medicine; National Health and Family Planning Commission of People's Republic of China; Guangzhou Science and Technology Bureau; AstraZeneca China.
The integration of multiple materials with complementary absorptions into a single junction device is regarded as an efficient way to enhance the power conversion efficiency (PCE) of organic solar ...cells (OSCs). However, because of increased complexity with one more component, only limited high-performance ternary systems have been demonstrated previously. Here we report an efficient ternary blend OSC with a PCE of 9.2%. We show that the third component can reduce surface trap densities in the ternary blend. Detailed studies unravel that the improved performance results from synergistic effects of enlarged open circuit voltage, suppressed trap-assisted recombination, enhanced light absorption, increased hole extraction, efficient energy transfer and better morphology. The working mechanism and high device performance demonstrate new insights and design guidelines for high-performance ternary blend solar cells and suggest that ternary structure is a promising platform to boost the efficiency of OSCs.
Previous research has revealed that environmental, social, and cultural factors affect people’s risk perception of COVID-19, especially the influence of media and trust, while the dynamics of how ...they affect it is still not clear. Through the analysis of online survey data, this article shows that there are two opposed paths of action. Trust in the government will enhance people’s confidence in controlling COVID-19. It then moderates and decreases the effects of people’s level and frequency of concernon the risk perception (both cognition and worries) of COVID-19, on the contrary, obtaining information from unofficial channels also moderates and increases the effects of the people’s level and frequency of concern on the second dimension (worries) of risk perception of COVID-19 rather than the first dimension (cognition). These conclusions have important policy implications for the control of the COVID-19 epidemic all over the world.
An efficient in situ Pd-NHC catalytic system for regioselective arylation of B(3,6)–H bonds of o-carborane has been developed for the first time. A series of symmetric and unsymmetric ...3,6-diaryl-o-carboranes anchored with active groups have been synthesized with moderate to good yields under mild conditions. This work offers an efficient protocol for selective activation of B(3,6)–H bonds and has important value in design coupling reactions for selective functionalization of o-carboranes.
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