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"Lin, Sen"
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ذات الرداء الأحمر، التي تشعر دائما بالفضول تجاه العالم، تريد زيارة جدتها عبر الغابة بمفردها. لكنها لا تستطيع رؤية طريقها، ما هي الصعوبات التي ستواجهها ؟ كيف يمكنها مواجهة الذئب الكبير بمفردها في الغابة ؟ في طريقها، تلتقي بأرنب وقنفذ وظربان. تتعلم استخدام مشاعرها لإدراك العالم، وشجاعتها وحكمتها لإنقاذ نفسها من المخاطر. والمثير للدهشة أن الذئب الكبير في عينيها لطيف جدا، لم يأكل الذئب السيئ الكبير ذات الرداء الأحمر هذه المرة فحسب، بل ساعد أيضا ذو الرداء الأحمر الصغير في الوصول إلى منزل جدته.
Book
Photocatalytic Oxygen Evolution from Water Splitting
Photocatalytic water splitting has attracted a lot of attention in recent years, and O2 evolution is the decisive step owing to the complex four‐electrons reaction process. Though many studies have been conducted, it is necessary to systematically summarize and introduce the research on photocatalytic O2 evolution, and thus a systematic review is needed. First, the corresponding principles about O2 evolution and some urgently encountered issues based on the fundamentals of photocatalytic water splitting are introduced. Then, several types of classical water oxidation photocatalysts, including TiO2, BiVO4, WO3, α‐Fe2O3, and some newly developed ones, such as Sillén–Aurivillius perovskites, porphyrins, metal–organic frameworks, etc., are highlighted in detail, in terms of their crystal structures, synthetic approaches, and morphologies. Third, diverse strategies for O2 evolution activity improvement via enhancing photoabsorption and charge separation are presented, including the cocatalysts loading, heterojunction construction, doping and vacancy formation, and other strategies. Finally, the key challenges and future prospects with regard to photocatalytic O2 evolution are proposed. The purpose of this review is to provide a timely summary and guideline for the future research works for O2 evolution. Photocatalytic O2 evolution reaction is the rate‐determining step in the water splitting process. This review provides a comprehensive summary on the progress of photocatalytic O2 evolution from water splitting, involving the fundamentals and mechanism of O2 evolution, several typical photocatalysts in terms of their crystal structures, synthetic approaches and morphologies, and diverse strategies for O2 evolution activity improvement.
Journal Article
Fast spin-flip enables efficient and stable organic electroluminescence from charge-transfer states
A spin-flip from a triplet to a singlet excited state, that is, reverse intersystem crossing (RISC), is an attractive route for improving light emission in organic light-emitting diodes, as shown by devices using thermally activated delayed fluorescence (TADF). However, device stability and efficiency roll-off remain challenging issues that originate from a slow RISC rate (kRISC). Here, we report a TADF molecule with multiple donor units that form charge-resonance-type hybrid triplet states leading to a small singlet–triplet energy splitting, large spin–orbit couplings, and a dense manifold of triplet states energetically close to the singlets. The kRISC in our TADF molecule is as fast as 1.5 × 107 s−1, a value some two orders of magnitude higher than typical TADF emitters. Organic light-emitting diodes based on this molecule exhibit good stability (estimated T90 about 600 h for 1,000 cd m−2), high maximum external quantum efficiency (>29.3%) and low efficiency roll-off (<2.3% at 1,000 cd m−2).An organic molecule, 5Cz-TRZ, with multiple donor units supports fast reverse intersystem crossing, allowing fabrication of high-performance organic light-emitting diodes.
Journal Article
Highly compressible and anisotropic lamellar ceramic sponges with superior thermal insulation and acoustic absorption performances
Advanced ceramic sponge materials with temperature-invariant high compressibility are urgently needed as thermal insulators, energy absorbers, catalyst carriers, and high temperature air filters. However, the application of ceramic sponge materials is severely limited due to their complex preparation process. Here, we present a facile method for large-scale fabrication of highly compressible, temperature resistant SiO
2
-Al
2
O
3
composite ceramic sponges by blow spinning and subsequent calcination. We successfully produce anisotropic lamellar ceramic sponges with numerous stacked microfiber layers and density as low as 10 mg cm
−3
. The anisotropic lamellar ceramic sponges exhibit high compression fatigue resistance, strain-independent zero Poisson’s ratio, robust fire resistance, temperature-invariant compression resilience from −196 to 1000 °C, and excellent thermal insulation with a thermal conductivity as low as 0.034 W m
−1
K
−1
. In addition, the lamellar structure also endows the ceramic sponges with excellent sound absorption properties, representing a promising alternative to existing thermal insulation and acoustic absorption materials.
Temperature-invariant highly compressible ceramic sponges are attractive for thermal insulators and energy absorbers, but development is limited by complex preparation processes. Here the authors report large-scale fabrication of silica-alumina composite ceramic sponges via blow spinning and calcination.
Journal Article
Frustrated Lewis Pairs in Heterogeneous Catalysis: Theoretical Insights
Frustrated Lewis pair (FLP) catalysts have attracted much recent interest because of their exceptional ability to activate small molecules in homogeneous catalysis. In the past ten years, this unique catalysis concept has been extended to heterogeneous catalysis, with much success. Herein, we review the recent theoretical advances in understanding FLP-based heterogeneous catalysis in several applications, including metal oxides, functionalized surfaces, and two-dimensional materials. A better understanding of the details of the catalytic mechanism can help in the experimental design of novel heterogeneous FLP catalysts.
Journal Article
Invasion of white matter tracts by glioma stem cells is regulated by a NOTCH1–SOX2 positive-feedback loop
CD133 and Notch1 double-positive GSCs were preferentially located along Jagged1-expressing white matter tracts, which exhibited a demyelinated phenotype. The NOTCH1–SOX9–SOX2 positive-feedback loop controls GSC invasion along white matter tracts.
Journal Article
HKDC1 upregulation promotes glycolysis and disease progression, and confers chemoresistance onto gastric cancer
There is increasing evidence that hexokinase is involved in cell proliferation and migration. However, the function of the hexokinase domain containing protein‐1 (HKDC1) in gastric cancer (GC) remains unclear. Immunohistochemistry analysis and big data mining were used to evaluate the correlation between HKDC1 expression and clinical features in GC. In addition, the biological function and molecular mechanism of HKDC1 in GC were studied by in vitro and in vivo assays. Our study indicated that HKDC1 expression was upregulated in GC tissues compared with adjacent nontumor tissues. High expression of HKDC1 was associated with worse prognosis. Functional experiments demonstrated that HKDC1 upregulation promoted glycolysis, cell proliferation, and tumorigenesis. In addition, HKDC1 could enhance GC invasion and metastasis by inducing epithelial–mesenchymal transition (EMT). Abrogation of HKDC1 could effectively attenuate its oncogenic and metastatic function. Moreover, HKDC1 promoted GC proliferation and migration in vivo. HKDC1 overexpression conferred chemoresistance to cisplatin, oxaliplatin, and 5‐fluorouracil (5‐Fu) onto GC cells. Furthermore, nuclear factor kappa‐B (NF‐κB) inhibitor PS‐341 could attenuate tumorigenesis, metastasis, and drug resistance ability induced by HKDC1 overexpression in GC cells. Our results highlight a critical role of HKDC1 in promoting glycolysis, tumorigenesis, and EMT of GC cells via activating the NF‐κB pathway. In addition, HKDC1‐mediated drug resistance was associated with DNA damage repair, which further activated NF‐κB signaling. HKDC1 upregulation may be used as a potential indicator for choosing an effective chemotherapy regimen for GC patients undergoing chemotherapy. HKDC1 upregulation predicts resistance to cisplatin, oxaliplatin and 5‐FU in patients with GC. HKDC1 upregulation may be used as a potential indicator for choosing an effective chemotherapy regimen for GC patients undergoing chemotherapy.
Journal Article
Carbon-doped BN nanosheets for metal-free photoredox catalysis
The generation of sustainable and stable semiconductors for solar energy conversion by photoredox catalysis, for example, light-induced water splitting and carbon dioxide reduction, is a key challenge of modern materials chemistry. Here we present a simple synthesis of a ternary semiconductor, boron carbon nitride, and show that it can catalyse hydrogen or oxygen evolution from water as well as carbon dioxide reduction under visible light illumination. The ternary B–C–N alloy features a delocalized two-dimensional electron system with
sp
2
carbon incorporated in the
h
-BN lattice where the bandgap can be adjusted by the amount of incorporated carbon to produce unique functions. Such sustainable photocatalysts made of lightweight elements facilitate the innovative construction of photoredox cascades to utilize solar energy for chemical conversion.
Metal-free semiconductors with appropriate bandgaps create photocatalytic routes to water splitting and CO
2
reduction. Here the authors dope hexagonal boron nitride nanosheets with carbon via a simple method to synthesize a ternary B–C–N alloy capable of performing just this function.
Journal Article
Usefulness of lactate to albumin ratio for predicting in-hospital mortality in atrial fibrillation patients admitted to the intensive care unit: a retrospective analysis from MIMIC-IV database
Background
High lactate to albumin ratio (LAR) has been reported to be associated to with poor prognosis in patients admitted to the intensive care unit (ICU). However, its role in predicting in-hospital mortality in AF patients admitted to ICU has not been explored.
Methods
The Medical Information Mart for Intensive Care-IV (MIMIC-IV) database was used to retrieve information on patients who had been diagnosed with AF. X-tile software was utilized to determine the optimal cut-off LAR. Area under the receiver operating characteristic curves (AUC), calibration plots, and decision curve analysis (DCA) were conducted to assess the prediction performance of LAR for in-hospital mortality.
Results
Finally, 8,287 AF patients were included and 1,543 death (18.6%) occurred. The optimal cut-off value of LAR is 0.5. Patients in lower LAR (< 0.5) group showed a better in-hospital survival compared to patients in higher LAR (≥ 0.5) group (HR: 2.67, 95%CI:2.39–2.97,
P
< 0.001). A nomogram for in-hospital mortality in patients with AF was constructed based on multivariate Cox analysis including age, CCI, β blockers usage, APSIII, hemoglobin and LAR. This nomogram exhibited excellent discrimination and calibration abilities in predicting in-hospital mortality for critically ill AF patients.
Conclusion
LAR, as a readily available biomarker, can predict in-hospital mortality in AF patients admitted to the ICU. The nomogram that combined LAR with other relevant variables performed exceptionally well in terms of predicting in-hospital mortality.
Journal Article
Digital Twin Model and Its Establishment Method for Steel Structure Construction Processes
At present, the informatization level in the construction process of steel structures is relatively low. Meanwhile, digital twin technology, with better interactive features, provides a new development direction for the intelligent construction of steel structures. Therefore, this paper introduces the concept of a digital twin into the steel structure construction process, analyzes the connotation and characteristics of the digital twin model, and proposes the digital twin model architecture for steel structure construction processes. Furthermore, a method for establishing a digital twin model for steel structure construction processes is presented, which includes three stages: the acquisition and transmission of physical space data, the construction of a digital twin virtual model, and information exchange in the digital twin model. Based on these concepts, this paper describes a digital twin system architecture for the steel structure construction process from the perspective of data flow in the digital twin model. Finally, with the application of information technology in the steel structure construction process of the university park library project in Xiongan New Area and the reconstruction and expansion project of the Nanchong Gaoping airport, the digital twin model and its establishment method methods are analyzed practically and demonstrated effectively in this study.
Journal Article