Thermally activated delayed fluorescent (TADF) materials generally suffer from severe concentration quenching. Efficient non‐doped TADF emitters are generally highly twisted aromatic amine‐based ...compounds with isolated chemical moieties. Herein we demonstrate that co‐facial packing and strong π–π intermolecular interactions give rise to bright TADF emissions in non‐doped film and crystalline states within the compound 2,4‐diphenyl‐6‐(thianthren‐1‐yl)‐1,3,5‐triazine (oTE‐DRZ). Quantum chemistry simulations indicate that a disperse outer orbital of sulfur atoms, a folded thianthrene plane (for a reduced donor–acceptor distance), and a triazine acceptor with n–π* character, generate a spatially conjugated transition with a small singlet–triplet splitting energy. In company with a highly emissive non‐doped film, the corresponding organic light‐emitting diode achieved a 20.6 % external quantum efficiency, verifying its potential for high‐performance optoelectronic applications. In a crystalline state, it was verified that intra‐ and intermolecular dual TADF assisted by a hidden room‐temperature phosphorescent state. This state could preserve the long‐lived excitons while suppressing non‐radiation, and it could serve as a “spring‐board” for cascade up‐conversion processes. The oTE‐DRZ crystal showed greenish‐blue emission with a very high photoluminescent quantum yield of approximately 87 %, which is the highest among all TADF crystals reported to date.
A purely organic crystal exhibiting a bright thermally activated delayed fluorescence (TADF; photoluminescent quantum yield up to 87 %) and a strong intermolecular π–π stacking is presented. Built‐in spatially conjugated intra‐ and intermolecular transitions give rise to dual TADF emissions assisted by a hidden room temperature phosphorescent state.
Abstract Twisted two-dimensional materials have recently attracted tremendous interest owing to their unique structures and fantastic electronic properties. However, the effect of interlayer twisting ...on the phonon transport properties is less known, especially for the twist-angle-dependent lattice thermal conductivity ( κ L ). Using the emerging Janus SnSSe bilayer as a prototypical example, we develop an accurate machine learning potential, which is adopted to efficiently predict the κ L at a series of twist angles via iterative solution of the Boltzmann transport equation. It is found that the κ L exhibits a distinct non-monotonous dependence on the twist angle, which can be traced back to the bonding heterogeneity between high-symmetry stacking regions inside the moiré unit cell. In contrast to the general belief, the optical phonons make a major contribution toward the κ L of the twisted structures. Moreover, we demonstrate that four-phonon scattering can significantly reduce the κ L of SnSSe bilayer at higher temperatures, which becomes more pronounced by interlayer twisting. Our work not only highlights the strong predictive power of machine learning potential, but also offers new insights into the design of thermal smart materials with tunable κ L .
Highly efficient organic thermally activated delayed fluorescence (TADF) and room‐temperature phosphorescence (RTP) emitters for organic light‐emitting diodes (OLEDs) generally consist of a twisted ...donor–acceptor skeleton with aromatic amine donors. Herein, through introducing sulfur atoms into isomeric pentaphene and pentacene frameworks, we demonstrate a set of polycyclic luminophores exhibiting efficient TADF and RTP characters. The incorporation of sulfur atoms confirms a folded molecular plane, while intensifies singlet–triplet spin‐orbit coupling. Further, the isomeric effect has a significant effect on the electronic structure of excited state, giving rise to the investigated compounds tunable luminescence mechanisms of TADF and RTP. With efficient triplet harvesting ability, maximum external quantum efficiencies up to 25.1 % and 8.7 % are achieved for the corresponding TADF and RTP OLEDs, verifying the great potential of sulfur‐bridged frameworks for highly efficient devices.
By incorporating powerful electron‐donating sulfur atoms into isomeric pentaphene and pentacene frameworks, three highly efficient polycyclic thermally activated delayed fluorescence (TADF), room‐temperature phosphorescence (RTP), and mixed TADF/RTP molecules were developed for application in organic light‐emitting diodes.
Ampullary adenocarcinoma (AMPAC) is a rare malignancy, treated as pancreatic or intestinal cancer based on its histologic subtype. Little is known about the genomic features of Chinese patients with ...AMPAC.
We enrolled 145 Chinese AMPAC patients in our local cohort and performed a compressive somatic and germline genetic testing using a 156 gene panel. Expression of PD-L1 (clone 28 - 8) was also assessed in tumor specimens from 64 patients.
The frequency of genetic alterations (GAs) in Chinese patients with AMPAC was found to be distinctive, with TP53, KRAS, SMAD4, APC, CTNNB1, ARID1A, and CDKN2A emerged as the most frequently mutated genes. Comparing with Western patients, significant differences were observed in the prevalence of PIK3CA and ARID2. Furthermore, the incidence of MSI-H was lower in the Chinese cohort, with only two patients identified as MSI-H. Conversely, 11 patients (8.27%) had pathogenic/likely pathogenic germline alterations, all of which were in the DNA damage response (DDR) pathway. In our cohort, 34.48% (22/64) of patients exhibited positive PD-L1 expression in tumor cells, and this expression was associated with GAs in CTNNB1 and BLM. Importantly, over three-fourths of Chinese AMPAC patients in our study had at least one actionable GA, with more than one-fifth of them having actionable GAs classified as Level 3. These actionable GAs were primarily involved in the DDR and PI3K pathways. Notably, GAs in the DDR pathway were detected in both Chinese and Western patients, and regardless of their functional impact, these alterations demonstrated enhanced overall survival rates and higher tumor mutational burden (TMB) levels.
These findings underscore the distinct genomic landscape of Chinese AMPAC patients and highlight the potential for targeted therapies based on the identified GAs.
To evaluate the effects of Tai Chi in the treatment of patients with chronic low back pain by Meta-analysis and to investigate its influencing factors. The study searched eight databases (PubMed, ...Embase, The Cochrane Library, Web of Science, China Knowledge Network, Wanfang, VIP, and CBM) from inception to October 2023. Two investigators independently selected 10 eligible randomized controlled trials (RCT) against inclusion and exclusion criteria, followed by data extraction and study quality assessment by ROB 2. The outcomes of interest were pain intensity and disability. The studies were combined using meta-analysis when statistical pooling of data was possible. The quality of the evidence was assessed using the GRADE approach. 10 randomized controlled studies with a total sample of 886 cases were included, of which 4 (40%) were assessed as low risk of bias. The effect size of Tai Chi for chronic low back pain was Weighted Mean Difference (WMD) with 95% Confidence Interval (CI) = -1.09 (-1.26, -0.92), p < 0.01, all achieving large effect sizes and statistically significant; the effect size for disability was Standard Mean Difference (SMD) with 95% CI = -1.75 (-2.02, -1.48), p < 0.01, and the combined effect sizes of physical health and mental health for quality of life were WMD (95% CI) = 4.18 (3.41, 4.95), p < 0.01; WMD (95% CI) = 3.23 (2.42, 4.04), p 30 and less than or equal to 30). The evidence quality evaluation showed that the evidence of pain, physical health of quality of life and mental health score was medium quality, while the evidence of disability and adverse reactions was low quality. Tai Chi has an obvious effect of in relieving chronic low back pain. Tai Chi alone and Tai Chi as supplementary therapy have good effects. Tai Chi in water have not been verified. Chen style Tai Chi and Yang's Tai Chi, intervention more than 30 times or less than 30 times had no significant difference in the effect of intervention on CLBP.
The astrophysical r process plays a vital role in the production of heavy elements. Modeling of the r process is sensitive to masses and further requires knowledge of masses beyond current ...experimental reach. Therefore, simulations of the r process offer a unique test bed for predicting mass extrapolations. We take a Machine-Learning (ML) approach to model the masses across the entire chart of nuclides. For the first time, we simulate r-process nucleosynthesis with a physics-based ML mass model. We compare simulated abundances to solar data in order to evaluate the model's performance far from stability. The resulting r-process abundances up to thorium and uranium qualitatively match those of the observed solar system abundance pattern, with the characteristic peaks well positioned. We propagate the mass uncertainties obtained from the ML model to r-process abundance yields to estimate an uncertainty band associated with our approach. The size of the uncertainty band is approximately one order of magnitude which aligns with the uncertainty reported using alternative techniques.
A series of vanadium doped cryptomelane-type manganese oxide (V-OMS-2) catalysts were prepared by a simple, low-cost reflux method, and investigated for one-pot imine synthesis from oxidative ...coupling of benzyl alcohol and aniline with air. The physicochemical properties of the V-OMS-2 catalysts were characterized by various techniques including XRD, BET, SEM, TEM, XPS, H2-TPR and NH3-TPD. It was found that the surface area, Lewis acid sites, the amount of Mn3+ component and active surface oxygen species were much improved with vanadium doping. Consequently, the activity of V-OMS-2 catalyst for oxidative coupling of benzyl alcohol and aniline to imine was enhanced. The highest conversion and the imine yield were obtained over the 3 mol% V-OMS-2 catalyst, being ∼99% and 92%, respectively. Higher vanadium doping (≥ 6 mol%), however, hindered the preservation of OMS-2 crystal structure, leading to a drop in the catalytic performance. The high specific surface area was suggested to be the key contributor to the high catalytic activity of 3% V-OMS-2(1) catalyst. Among the vanadium precursors studied, the catalyst prepared with vanadium pentoxide exhibited a much higher catalytic activity, which can be attributed to its larger surface area, unique mesoporous structure, increased Lewis acid sites and more readily available surface oxygen species. In addition, the stability and recyclability of the catalyst were also studied, and the reaction mechanism was discussed.
•V-doped OMS-2 catalysts were studied for imine synthesis from air-oxidative coupling of benzyl alcohol and aniline.•3%V-OMS-2(1) catalyst showed the best benzyl alcohol conversion of >99% and highest imine yield of 92%.•The activity promotion was related to the increased surface area, acid sites and active surface oxygen species by V doping.•The vanadium precursor influenced the V-OMS-2 catalyst structure and consequently its performance for imine synthesis.
Chemokine receptors play crucial roles in fundamental biological processes. Their malfunction may result in many diseases, including cancer, autoimmune diseases, and HIV. The oligomerization of ...chemokine receptors holds significant functional implications that directly affect their signaling patterns and pharmacological responses. However, the oligomerization patterns of many chemokine receptors remain poorly understood. Furthermore, several chemokine receptors have highly truncated isoforms whose functional role is not yet clear. Here, we computationally show homo- and heterodimerization patterns of four human chemokine receptors, namely CXCR2, CXCR7, CCR2, and CCR7, along with their interaction patterns with their respective truncated isoforms. By combining the neural network-based AlphaFold2 and physics-based protein–protein docking tool ClusPro, we predicted 15 groups of complex structures and assessed the binding affinities in the context of atomistic molecular dynamics simulations. Our results are in agreement with previous experimental observations and support the dynamic and diverse nature of chemokine receptor dimerization, suggesting possible patterns of higher-order oligomerization. Additionally, we uncover the strong potential of truncated isoforms to block homo- and heterodimerization of chemokine receptors, also in a dynamic manner. Our study provides insights into the dimerization patterns of chemokine receptors and the functional significance of their truncated isoforms.
Abstract
Over the past few decades, molecular dynamics simulations and first-principles calculations have become two major approaches to predict the lattice thermal conductivity (
κ
L
), which are ...however limited by insufficient accuracy and high computational cost, respectively. To overcome such inherent disadvantages, machine learning (ML) has been successfully used to accurately predict
κ
L
in a high-throughput style. In this review, we give some introductions of recent ML works on the direct and indirect prediction of
κ
L
, where the derivations and applications of data-driven models are discussed in details. A brief summary of current works and future perspectives are given in the end.
Fast spin-flipping is the key to exploit the triplet excitons in thermally activated delayed fluorescence based organic light-emitting diodes toward high efficiency, low efficiency roll-off and long ...operating lifetime. In common donor-acceptor type thermally activated delayed fluorescence molecules, the distribution of dihedral angles in the film state would have significant influence on the photo-physical properties, which are usually neglected by researches. Herein, we find that the excited state lifetimes of thermally activated delayed fluorescence emitters are subjected to conformation distributions in the host-guest system. Acridine-type flexible donors have a broad conformation distribution or bimodal distribution, in which some conformers feature large singlet-triplet energy gap, leading to long excited state lifetime. Utilization of rigid donors with steric hindrance can restrict the conformation distributions in the film to achieve degenerate singlet and triplet states, which is beneficial to efficient reverse intersystem crossing. Based on this principle, three prototype thermally activated delayed fluorescence emitters with confined conformation distributions are developed, achieving high reverse intersystem crossing rate constants greater than 10
s
, which enable highly efficient solution-processed organic light-emitting diodes with suppressed efficiency roll-off.
