Confinement-Modulated Clusterization-Triggered Time-Dependent Phosphorescence Color from Xylan-Carbonized Polymer Dots.

Achieving time-dependent phosphorescence color (TDPC) in organic materials is attractive but extremely challenging due to the nonradiative decay and modulation puzzle of triplet state. Herein, xylan, a hemicellulose waste from the paper mill, was used to construct carbonized polymer dots (CPDs) with clusterization-triggered room-temperature phosphorescence (RTP). CPDs were endowed with tuneable triplet energy levels by through-space conjugation of heteroatom groups, which could be confined in silica to simultaneously activate surface oxide-related low-energy and cross-linked core N-related high-energy emissive centers. Thus, the blue emissive center with a lifetime of 425.6 ms and green emissive center with a longer lifetime of 1506 ms coexisted in the confined CPDs; the former was the dominant contribution to RTP at first, and the latter became dominant over time, leading to a typical TDPC evolution with large color contrast from blue to blue-green and then to green. Meanwhile, the TDPC could remain unobstructed after the confined CPDs were soaked in water for more than a month. The CPDs were successfully applied in location and deformation imaging of hydrogel and advanced dynamic information encryption and anticounterfeiting. The work may shed new light on the design of TDPC materials and broaden the high-value use of paper-mill waste xylan.

Facile Preparation of Full-Color Tunable Room Temperature Phosphorescence Cellulose via Click Chemistry.

Sustainable long-lived room temperature phosphorescence (RTP) materials with color-tunable afterglows are attractive but rarely reported. Here, cellulose is reconstructed by directed redox to afford ample active hydroxyl groups and water-solubility; arylboronic acids with various π conjugations can be facilely anchored to reconstructed cellulose via click chemistry within 1 min in pure water, resulting in full-color tunable RTP cellulose. The rigid environment provided by the B─O covalent bonds and hydrogen bonds can stabilize the triplet excitons, thus the target cellulose displays outstanding RTP performances with the lifetime of 2.67 s, phosphorescence quantum yield of 9.37%, and absolute afterglow luminance of 348 mcd m-2. Furthermore, due to the formation of various emissive species, the smart RTP cellulose shows excitation- and time-dependent afterglows. Taking advantages of sustainability, ultralong lifetime, and full-color tunable afterglows, et al, the environmentally friendly RTP cellulose is successfully used for nontoxic afterglow inks, delay lighting, and afterglow display.

Promoting Oxygen Evolution Electrocatalysis by Coordination Engineering in Cobalt Phosphate.

Understanding the structure-activity correlation is an important prerequisite for the rational design of high-efficiency electrocatalysts at the atomic level. However, the effect of coordination environment on electrocatalytic oxygen evolution reaction (OER) remains enigmatic. In this work, the regulation of proton transfer involved in water oxidation by coordination engineering based on Co3(PO4)2 and CoHPO4 is reported. The HPO4 2- anion has intermediate pKa value between Co(II)-H2O and Co(III)-H2O to be served as an appealing proton-coupled electron transfer (PCET) induction group. From theoretical calculations, the pH-dependent OER properties, deuterium kinetic isotope effects, operando electrochemical impedance spectroscopy (EIS) and Raman studies, the CoHPO4 catalyst beneficially reduces the energy barrier of proton hopping and modulates the formation energy of high-valent Co species, thereby enhancing OER activity. This work demonstrates a promising strategy that involves tuning the local coordination environment to optimize PCET steps and electrocatalytic activities for electrochemical applications. In addition, the designed system offers a motif to understand the structure-efficiency relationship from those amino-acid residue with proton buffer ability in natural photosynthesis.

The association of post-embryo transfer SARS-CoV-2 infection with early pregnancy outcomes in in vitro fertilization: a prospective cohort study.

BACKGROUND: The influence of SARS-CoV-2 infection after embryo transfer on early pregnancy outcomes in in vitro fertilization or intracytoplasmic sperm injection-embryo transfer treatment remains inadequately understood. This knowledge gap endures despite an abundance of studies investigating the repercussions of preceding SARS-CoV-2 infection on early pregnancy outcomes in spontaneous pregnancies. OBJECTIVE: This study aimed to investigate the association between SARS-CoV-2 infection within 10 weeks after embryo transfer and early pregnancy outcomes in patients undergoing in vitro fertilization/intracytoplasmic sperm injection treatment. STUDY DESIGN: This prospective cohort study was conducted at a single public in vitro fertilization center in China. Female patients aged 20 to 39 years, with a body mass index ranging from 18 to 30 kg/m2, undergoing in vitro fertilization/intracytoplasmic sperm injection treatment, were enrolled between September 2022 and December 2022, with follow-up extended until March 2023. The study tracked SARS-CoV-2 infection time (≤14 days, ≤28 days, and ≤10 weeks after embryo transfer), symptoms, vaccination status, the interval between vaccination and embryo transfer, and early pregnancy outcomes, encompassing biochemical pregnancy rate, implantation rate, clinical pregnancy rate, and early miscarriage rate. The study used single-factor analysis and multivariate logistic regression to examine the association between SARS-CoV-2 infection status, along with other relevant factors, and the early pregnancy outcomes. RESULTS: A total of 857 female patients undergoing in vitro fertilization/intracytoplasmic sperm injection treatment were analyzed. In the first stage, SARS-CoV-2 infection within 14 days after embryo transfer did not have a significant negative association with the biochemical pregnancy rate (adjusted odds ratio, 0.74; 95% confidence interval, 0.51-1.09). In the second stage, SARS-CoV-2 infection within 28 days after embryo transfer had no significant association with the implantation rate (36.6% in infected vs 44.0% in uninfected group; P=.181). No statistically significant association was found with the clinical pregnancy rate after adjusting for confounding factors (adjusted odds ratio, 0.69; 95% confidence interval, 0.56-1.09). In the third stage, SARS-CoV-2 infection within 10 weeks after embryo transfer had no significant association with the early miscarriage rate (adjusted odds ratio, 0.77; 95% confidence interval, 0.35-1.71). CONCLUSION: Our study suggests that SARS-CoV-2 infection within 10 weeks after embryo transfer may not be negatively associated with the biochemical pregnancy rate, implantation rate, clinical pregnancy rate, and early miscarriage rate in patients undergoing in vitro fertilization/intracytoplasmic sperm injection treatment. It is important to note that these findings are specific to the target population of in vitro fertilization/intracytoplasmic sperm injection patients aged 20 to 39 years, without previous SARS-CoV-2 infection, and with a body mass index of 18 to 30 kg/m2. This information offers valuable insights, addressing current concerns and providing a clearer understanding of the actual risk associated with SARS-CoV-2 infection after embryo transfer.

Antimony Doping Enabled Photoluminescence Quantum Yield Enhancement in 0D Inorganic Bismuth Halide Crystals.

Owing to the exterior self-trapped excitons (STEs) with adjustable fluorescence beams, low-dimensional ns2-metal halides have recently received considerable attention in solid-state light-emitting applications. However, the photoluminescence (PL) mechanism in metal halides remains a major challenge in achieving high efficiency and controllable PL properties because the excited-state energy of ns2 conformational ions varies inhomogeneously with their coordination environments. Here, a novel zero-dimensional (0D) lead-free bismuth-based Rb3BiCl6·0.5H2O crystal was reported as a pristine crystal to modulate the optical properties. By doping Sb3+ ions with 5s2 electrons into Rb3BiCl6·0.5H2O crystals, bright orange emission at room temperature was obtained with a photoluminescence quantum yield of 39.7%. Optical characterizations and theoretical studies show that the Sb3+ doping can suppress the strong exciton-phonon coupling, optimize the electronic energy band structure, improve the thermal activation energy, soften the structural lattice of the host crystals, deepen the STE states, and ultimately lead to strong photoluminescence. This work manifests a fruitful manipulation in ripening bismuth-based halides with high-efficiency PL properties, and the PL enhancement mechanisms will guide future research in the exploration of emerging luminescent materials.

Multi-Objective Optimal Trajectory Planning for Robotic Arms Using Deep Reinforcement Learning.

This study investigated the trajectory-planning problem of a six-axis robotic arm based on deep reinforcement learning. Taking into account several characteristics of robot motion, a multi-objective optimization approach is proposed, which was based on the motivations of deep reinforcement learning and optimal planning. The optimal trajectory was considered with respect to multiple objectives, aiming to minimize factors such as accuracy, energy consumption, and smoothness. The multiple objectives were integrated into the reinforcement learning environment to achieve the desired trajectory. Based on forward and inverse kinematics, the joint angles and Cartesian coordinates were used as the input parameters, while the joint angle estimation served as the output. To enable the environment to rapidly find more-efficient solutions, the decaying episode mechanism was employed throughout the training process. The distribution of the trajectory points was improved in terms of uniformity and smoothness, which greatly contributed to the optimization of the robotic arm's trajectory. The proposed method demonstrated its effectiveness in comparison with the RRT algorithm, as evidenced by the simulations and physical experiments.

Urbanization and vulnerable employment: Empirical evidence from 163 countries in 1991-2019.

Many urban residents have recently lost their jobs due to the COVID-19 pandemic, which has made employment vulnerability in cities attained attention. It is thus important to explore the relationship between urbanization and employment. This study quantitatively analyzes spatiotemporal evolution and data correlation of urbanization and vulnerable employment, and explores the role urbanization plays in vulnerable employment by using historical data on 163 countries in the period 1991-2019 to test the theoretical hypothesis. The results show: It's clearly observed that there is a high correlation between the rate of urbanization and that of vulnerable employment, and the examples of G7 and BRICs are for it. The estimated urbanization yields a negative and statistically significant regression coefficient (-0.168), indicating that urbanization has a negative effect on vulnerable employment. If the urbanization rate increased by 1 %, the rate of vulnerable employment decreased by 0.168 %. The rural-urban sector conversion and changes in employment relationship driven by urbanization account for this. Countries with different income groups or populations have reacted differently to the rise in urbanization. Vulnerable employment in higher-income countries has been more significantly affected by the rise in urbanization, and more populous countries are more sensitive to it as well. These findings provide evidence for how urbanization promotes employment and decent work.

Facile Tuned TSCT-TADF in Donor-Acceptor MOF for Highly Adjustable Photonic Modules based on Heterostructures Crystals.

Highly adjustable photonic modules were constructed based on the heterostructures crystals of a new series of donor-acceptor metal-organic framework (D-A MOF) featuring highly tunable thermally activated delayed fluorescence (TADF). By introducing N-phenylcarbazole and derivatives as donor guests into the acceptor host NKU-111, highly tunable through-space charge transfer based TADF could be achieved through the engineering of heavy atom effect, which result in modulatable emission wavelength (540 to 600 nm) and enhanced quantum yield (up to 30.86 %). Furthermore, by rationally integrating the D-A MOFs with distinctive emissions, rod-like heterostructures crystals featuring excitation position dependent tip emissions in wide wavelength range (495 to 598 nm) could be fabricated, which could serve as highly potential photonic modules for photonic circuit applications.

Effect of artificial cycle with or without GnRH-a pretreatment on pregnancy and neonatal outcomes in women with PCOS after frozen embryo transfer: a propensity score matching study.

BACKGROUND: In frozen embryo transfer (FET), there is limited consensus on the best means of endometrial preparation in terms of the reproductive outcomes in women with polycystic ovary syndrome (PCOS). The present study aimed to compare the pregnancy and neonatal outcomes following artificial cycle FET (AC-FET) with or without gonadotropin-releasing hormone agonist (GnRH-a) pretreatment among women with PCOS. METHODS: A total of 4503 FET cycles that satisfied the inclusion criteria were enrolled in this retrospective cohort study between 2015 and 2020. The GnRH-a group received GnRH-a pretreatment while the AC-FET group did not. Propensity score matching (PSM) method and multivariate logistic regression analysis were performed to adjust for potential confounding factors. RESULTS: After PSM, women in the GnRH-a group suffered a significantly lower miscarriage rate (11.2% vs. 17.1%, P = 0.033) and a higher live birth rate (LBR) compared with those in the AC-FET group (63.1% vs. 56.8%, P = 0.043). No differences were observed in the rates of biochemical pregnancy, clinical pregnancy and ectopic pregnancy between the two groups. A higher mean gestational age at birth was observed in the GnRH-a group than in the AC-FET group (39.80 ± 2.01 vs. 38.17 ± 2.13, P = 0.009). The incidence of neonatal preterm birth (PTB) in the GnRH-a group was lower than that in the AC-FET group (7.4% vs. 14.9%, P = 0.009). Singleton newborns conceived after GnRH-a group were more likely to be small for gestational age (SGA) than those born after AC-FET group (16.4% vs. 6.8%, P = 0.009). However, no significant differences were found between the two groups in terms of mean birthweight, apgar score, the rates of macrosomia, large for gestational age and low birth weight. CONCLUSION(S): In women with PCOS who underwent AC-FET, GnRH-a pretreatment was significantly associated with a higher live birth rate and a reduced risk of neonatal PTB. However, there was a concomitant increase in the risk of developing SGA babies.

Selective Expression of a Carbazole-Phenothiazine Derivative Leads to Dual-mode AIEE, TADF and Distinctive Mechanochromism.

In this article, we report a newly designed D-A-D' derivative (CNCzPTZ), which displays selective expression of chromophores. This enables CNCzPTZ with solvatochromism, rare dual-mode AIEE properties, solid-state dual-emissions with phosphorescence and distinctive mechanochromism.CNCzPTZ exhibits dual-mode AIEE properties, since the emission band abruptly shifts from 550 nm to 500 nm as the water fraction increases. In the crystalline state, CNCzPTZ demonstrated dual emission bands of 478 nm and 538 nm.CNCzPTZ shows distinctive mechanochromic property in the solid state due to the planarization.

A20 attenuates hypoxia-induced pulmonary arterial hypertension by inhibiting NF-κB activation and pulmonary artery smooth muscle cell proliferation.

PAH is a progressive disease characterized by uncontrolled proliferation of PASMCs. Zinc finger protein A20 is a negative feedback regulatory protein of NF-κB activity. The aim of this study was to evaluate zinc finger protein A20 can alleviate PAH in hypoxia exposed mice. C57BL/6 mice received a tail vein injection of adenovirus-mediated ad-A20 and ad-A20 shRNA were exposed to hypoxia. PASMCs isolated from rat pulmonary arteries were cultured in hypoxia, and were transfection of A20 adenovirus. Pulmonary hemodynamic parameters were measured by right heart catheterization. Pulmonary vascular morphological changes were analyzed by HE and α-SMA staining. The expression changes of A20, NF-κB and its downstream protein were detected. The expression of phospho-p65 was increased with the prolongation of hypoxia time. The expression of A20 in lung tissue of chronic hypoxia group decreased with the prolongation of hypoxia time. Adenovirus-mediated A20 (ad-A20) overexpression significantly attenuated the abnormally increased RVSP, RV/(LV + S) ratio, WT%, WA%, α-SMA and the pulmonary vessel muscularization. Ad-A20 treatment markedly attenuated the degradation of phospho-p65 and inhibited the induction of phospho-IκBα induced by hypoxia treatment. Furthermore, silencing A20 abolished the protection by anti-inflammatory activity and the inhibitory effect on cell proliferation. We showed that Zinc finger protein A20 can block NF-κB signaling pathway, alleviates the hypoxia-induced abnormal elevation of pulmonary arterial pressure, hyperproliferation of PASMCs and the pulmonary vascular remodeling.

Single and Combined Use of Preoperative Inflammatory Biomarkers and CA199 in Diagnosing Pancreatic Cancer.

BACKGROUND: To determine the diagnostic value of preoperative inflammatory biomarkers and CA199, alone or in combination, in diagnosing pancreatic cancer (PCC). METHODS: This retrospective study was comprised of 75 PCC patients and 83 healthy controls (HC). The participant's medical data was mined from the electronic records of the First Affiliated Hospital of Guangxi Medical University. The data included the preoperative circulating albumin/fibrinogen ratio (AFR), the platelet/lymphocyte ratio (PLR), the lymphocyte/monocyte ratio (LMR), the neutrophil/lymphocyte ratio (NLR), and the derived NLR (dNLR). The receiver operating characteristic (ROC) curve and the area under the ROC curve (AUROC) were used to evaluate the diagnostic efficacy of these candidate biomarkers for PCC. RESULTS: A single AFR significantly distinguished PCC from the healthy controls (AUROC: 0.903, 95% CI: 0.846 - 0.945) and had a significantly higher sensitivity and larger AUROC than CA199 (AUROC: 0.814, 95% CI: 0.774 - 0.871). The combinations of AFR with CA199 (AUROC: 0.932, 95% CI: 0.881 - 0.966), RDW with CA199 (AUROC: 0.905, 95% CI: 0.849 - 0.946), Alb with CA199 (AUROC: 0.869, 95% CI: 0.806 - 0.917), and Fib with CA199 (AUROC: 0.921, 95% CI: 0.868 - 0.958) also yielded higher sensitivities and larger AUROCs than CA199 alone. CONCLUSIONS: Circulating AFR was an effective biomarker in diagnosing PCC. Combining AFR, RDW, Alb, and Fib with CA199 could improve the diagnostic efficacy for PCC.

Berberine attenuates hypoxia-induced pulmonary arterial hypertension via bone morphogenetic protein and transforming growth factor-ß signaling.

Hypoxia-induced excessive pulmonary artery smooth muscle cell (PASMC) proliferation plays an important role in the pathology of pulmonary arterial hypertension (PAH). Berberine (BBR) is reported as an effective antiproliferative properties applied in clinical. However, the effect of BBR on PAH remains unclear. In the present study, we elucidated the protective effects of BBR against abnormal PASMC proliferation and vascular remodeling in chronic hypoxia-induced hearts. Furthermore, the potential mechanisms of BBR were investigated. For this purpose, C57/BL6 mice were exposed to chronic hypoxia for 4 weeks to mimic severe PAH. Hemodynamic and pulmonary pathomorphology data showed that chronic hypoxia significantly increased the right ventricular systolic pressure (RVSP), the right ventricle/left ventricle plus septum RV/(LV + S) weight ratio, and the median width of pulmonary arterioles. BBR attenuated the elevations in RVSP and RV/(LV + S) and mitigated pulmonary vascular structure remodeling. BBR also suppressed the hypoxia-induced increases in the expression of proliferating cell nuclear antigen (PCNA) and of α-smooth muscle actin. Furthermore, administration of BBR significantly increased the expression of bone morphogenetic protein type II receptor (BMPR-II) and its downstream molecules P-smad1/5 and decreased the expression of transforming growth factor-ß (TGF-ß) and its downstream molecules P-smad2/3. Moreover, peroxisome proliferator-activated receptor γ expression was significantly decreased in the hypoxia group, and this decrease was reversed by BBR treatment. Our study demonstrated that the protective effect of BBR against hypoxia-induced PAH in a mouse model may be achieved through altered BMPR-II and TGF-ß signaling.

2D Metal-Organic Framework Derived CuCo Alloy Nanoparticles Encapsulated by Nitrogen-Doped Carbonaceous Nanoleaves for Efficient Bifunctional Oxygen Electrocatalyst and Zinc-Air Batteries.

The development of efficient bifunctional electrocatalysts for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) still remains a challenge in a wide range of renewable energy technologies. Herein, CuCo alloy nanoparticles encapsulated by nitrogen-doped carbonaceous nanoleaves (CuCo-NC) have been synthesized from a Cu(OH)2 /2D leaf-like zeolitic imidazolate framework (ZIF-L)-pyrolysis approach. Leaf-like Cu(OH)2 is first prepared by the ultrasound-induced self-assembly of Cu(OH)2 nanowires. The efficient encapsulation of Cu(OH)2 in ZIF-L is obtained owing to the morphology fitting between the leaf-like Cu(OH)2 and ZIF-L. CuCo-NC catalysts present superior electrocatalytic activity and stability toward ORR and OER over the commercial Pt/C and IrO2 , respectively, which are further used as bifunctional oxygen electrocatalysts in Zn-air batteries and exhibit impressive performance, with a high peak power density of 303.7 mW cm-2 , large specific capacity of up to 751.4 mAh g-1 at 20 mA cm-2 , and a superior recharge stability.

Ultra-thin Co-Fe Layered Double Hydroxide Hollow Nanocubes for Efficient Electrocatalytic Water Oxidation.

Hierarchical hollow nanocubes based on ultra-thin CoFe-layered double hydroxide (CoFe-LDH) nanosheets have been prepared. The obtained CoFe-LDH hollow nanocubes could effectively catalyze water oxidation at a low overpotential of 270 mV @ 10 mA cm-2 , low Tafel slope of 58.3 mV dec-1 and show a long-term stability in alkali.

O-Linked ß-N-Acetylglucosamine Modification of A20 Enhances the Inhibition of NF-κB (Nuclear Factor-κB) Activation and Elicits Vascular Protection After Acute Endoluminal Arterial Injury.

OBJECTIVE: Recently, we have demonstrated that acute glucosamine-induced augmentation of protein O-linked ß-N-acetylglucosamine (O-GlcNAc) levels inhibits inflammation in isolated vascular smooth muscle cells and neointimal formation in a rat model of carotid injury by interfering with NF-κB (nuclear factor-κB) signaling. However, the specific molecular target for O-GlcNAcylation that is responsible for glucosamine-induced vascular protection remains unclear. In this study, we test the hypothesis that increased A20 (also known as TNFAIP3 [tumor necrosis factor α-induced protein 3]) O-GlcNAcylation is required for glucosamine-mediated inhibition of inflammation and vascular protection. APPROACH AND RESULTS: In cultured rat vascular smooth muscle cells, both glucosamine and the selective O-linked N-acetylglucosaminidase inhibitor thiamet G significantly increased A20 O-GlcNAcylation. Thiamet G treatment did not increase A20 protein expression but did significantly enhance binding to TAX1BP1 (Tax1-binding protein 1), a key regulatory protein for A20 activity. Adenovirus-mediated A20 overexpression further enhanced the effects of thiamet G on prevention of TNF-α (tumor necrosis factor-α)-induced IκB (inhibitor of κB) degradation, p65 phosphorylation, and increases in DNA-binding activity. A20 overexpression enhanced the inhibitory effects of thiamet G on TNF-α-induced proinflammatory cytokine expression and vascular smooth muscle cell migration and proliferation, whereas silencing endogenous A20 by transfection of specific A20 shRNA significantly attenuated these inhibitory effects. In balloon-injured rat carotid arteries, glucosamine treatment markedly inhibited neointimal formation and p65 activation compared with vehicle treatment. Adenoviral delivery of A20 shRNA to the injured arteries dramatically reduced balloon injury-induced A20 expression and inflammatory response compared with scramble shRNA and completely abolished the vascular protection of glucosamine. CONCLUSIONS: These results suggest that O-GlcNAcylation of A20 plays a key role in the negative regulation of NF-κB signaling cascades in TNF-α-treated vascular smooth muscle cells in culture and in acutely injured arteries, thus protecting against inflammation-induced vascular injury.

Topological Phase Transition with Nanoscale Inhomogeneity in (Bi1- xIn x)2Se3.

Topological insulators are a class of band insulators with nontrivial topology, a result of band inversion due to the strong spin-orbit coupling. The transition between topological and normal insulator can be realized by tuning the spin-orbit coupling strength and has been observed experimentally. However, the impact of chemical disorders on the topological phase transition was not addressed in previous studies. Herein, we report a systematic scanning tunneling microscopy/spectroscopy and first-principles study of the topological phase transition in single crystals of In-doped Bi2Se3. Surprisingly, no band gap closure was observed across the transition. Furthermore, our spectroscopic-imaging results reveal that In defects are extremely effective "suppressors" of the band inversion, which leads to microscopic phase separation of topological-insulator-like and normal-insulator-like nano regions across the "transition". The observed topological electronic inhomogeneity demonstrates the significant impact of chemical disorders in topological materials, shedding new light on the fundamental understanding of topological phase transition.

Crystal-State Photochromism and Dual-Mode Mechanochromism of an Organic Molecule with Fluorescence, Room-Temperature Phosphorescence, and Delayed Fluorescence.

A D-A-D' type pure organic molecule, named ODFRCZ, has unique triple-emission character covering fluorescence, phosphorescence, and delayed fluorescence (DF). The phosphorescence of ODFRCZ has a rather long lifetime of about 350 ms at room temperature. One dimer of ODFRCZ with enhanced parallel molecular packing acts more effectively to prompt ISC processes, which further generates room-temperature phosphorescence (RTP), owing to the larger transition dipole moment and closer energy level between S1 and Tn . ODFRCZ is a rare example of an organic RTP molecule that shows dual-stimuli responsiveness of dual-mode mechanochromism (fluorescence red-shift and RTP/DF on-off switch) and reversible crystal-state photochromism. This work may broaden the knowledge for stimuli-responsive RTP organic molecules and lay the foundation for their wide-scale applications.

Thermally Activated Delayed Fluorescence in an Organic Cocrystal: Narrowing the Singlet-Triplet Energy Gap via Charge Transfer.

Harvesting non-emissive spin-triplet charge-transfer (CT) excitons of organic semiconductors is fundamentally important for increasing the operation efficiency of future devices. Here we observe thermally activated delayed fluorescence (TADF) in a 1:2 CT cocrystal of trans-1,2-diphenylethylene (TSB) and 1,2,4,5-tetracyanobenzene (TCNB). This cocrystal system is characterized by absorption spectroscopy, variable-temperature steady-state and time-resolved photoluminescence spectroscopy, single-crystal X-ray diffraction, and first-principles calculations. These data reveal that intermolecular CT in cocrystal narrows the singlet-triplet energy gap and therefore facilitates reverse intersystem crossing (RISC) for TADF. These findings open up a new way for the future design and development of novel TADF materials.

Hyaluronidase2 (Hyal2) modulates low shear stress-induced glycocalyx impairment via the LKB1/AMPK/NADPH oxidase-dependent pathway.

The endothelium glycocalyx layer (ECL), presents on the apical surface of endothelial cells, creates a barrier between circulating blood and the vessel wall. Low shear stress (LSS) may accelerate the degradation of the glycocalyx via hyaluronidase2 (Hyal2) and then alter the cell polarity. Yet the liver kinase B1 (LKB1) signaling pathway plays an important role in regulating cell polarity. However, the relationship between LKB1 and glycocalyx during LSS is not clear. In the current study, we demonstrate that LSS attenuates LKB1 and AMP-activated protein kinase activation as well as activated nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (p47phox ) and Hyal2 in the human umbilical vein endothelial cell (HUVEC). Pretreatment with 5-Aminoimidazole-4-carboxamide1-ß-D-ribofuranoside (AICAR), or diphenyleneiodonium (DPI chloride) and transfection with LKB1 overexpression vector and p47phox small interfering RNA downregulated LSS-induced Hyal2 activation. By coimmunoprecipitation, we discovered the existence of p47phox /Hyal2 complex. LSS induced the dissociation of p47phox /Hyal2 complex, which was inhibited by LKB1 overexpression and AICAR. Furthermore, knockdown of Hyal2 performed a positive feedback on LKB1 activity. In addition, we also show that LSS enhanced LKB1 translocation from the cytosol to the nucleus. Taken together, these data indicate that Hyal2 regulates LSS-induced injury of the glycocalyx via LKB1/AMPK/NADPH oxidase signaling cascades.