Electro-Oxidative C3-Selenylation of Pyrido[1,2-a]pyrimidin-4-ones.

In this work, we achieved a C3-selenylation of pyrido[1,2-a]pyrimidin-4-ones using an electrochemically driven external oxidant-free strategy. Various structurally diverse seleno-substituted N-heterocycles were obtained in moderate to excellent yields. Through radical trapping experiments, GC-MS analysis and cyclic voltammetry study, a plausible mechanism for this selenylation was proposed.

Suppressing Andreev Bound State Zero Bias Peaks Using a Strongly Dissipative Lead.

Hybrid semiconductor-superconductor nanowires are predicted to host Majorana zero modes that induce zero-bias peaks (ZBPs) in tunneling conductance. ZBPs alone, however, are not sufficient evidence due to the ubiquitous presence of Andreev bound states. Here, we implement a strongly resistive normal lead in InAs-Al nanowire devices and show that most of the expected Andreev bound state-induced ZBPs can be suppressed, a phenomenon known as environmental Coulomb blockade. Our result is the first experimental demonstration of this dissipative interaction effect on Andreev bound states and can serve as a possible filter to narrow down the ZBP phase diagram in future Majorana searches.

Highly Efficient Near-Infrared Thermally Activated Delayed Fluorescent Emitters in Non-Doped Electroluminescent Devices.

Constructing organic near-infrared (NIR) luminescent materials to confront the formidable barrier of "energy gap law" remains challenging. Herein, two NIR thermally activated delayed fluorescence (TADF) molecules named T-ß-IQD and TIQD were developed by connecting N,N-diphenylnaphthalen-2-amine and triphenylamine with a novel electron withdrawing unit 6-(4-(tert-butyl)phenyl)-6H-indolo[2,3-b]quinoxaline-2,3-dicarbonitrile. It is confirmed NIR-TADF emitters concurrent with aggregation-induced emission effect, J-aggregate with intra- and intermolecular CN⋅⋅⋅H-C and C-H⋅⋅⋅π interactions, and large center-to-center distance in solid states can boost the emissive efficiencies both in thin films and non-doped organic light-emitting diodes (OLEDs). Consequently, the T-ß-IQD-based non-doped NIR-OLED achieved the maximum external quantum efficiency (EQEmax ) of 9.44 % with emission peak at 711 nm, which is one of the highest efficiencies reported to date for non-doped NIR-OLEDs.

Pixel Self-Attention Guided Real-Time Instance Segmentation for Group Raised Pigs.

Instance segmentation is crucial to modern agriculture and the management of pig farms. In practical farming environments, challenges arise due to the mutual adhesion, occlusion, and dynamic changes in body posture among pigs, making accurate segmentation of multiple target pigs complex. To address these challenges, we conducted experiments using video data captured from varying angles and non-fixed lenses. We selected 45 pigs aged between 20 and 105 days from eight pens as research subjects. Among these, 1917 images were meticulously labeled, with 959 images designated for the training set, 192 for validation, and 766 for testing. To enhance feature utilization and address limitations in the fusion process between bottom-up and top-down feature maps within the feature pyramid network (FPN) module of the YOLACT model, we propose a pixel self-attention (PSA) module, incorporating joint channel and spatial attention. The PSA module seamlessly integrates into multiple stages of the FPN feature extraction within the YOLACT model. We utilized ResNet50 and ResNet101 as backbone networks and compared performance metrics, including AP0.5, AP0.75, AP0.5-0.95, and AR0.5-0.95, between the YOLACT model with the PSA module and YOLACT models equipped with BAM, CBAM, and SCSE attention modules. Experimental results indicated that the PSA attention module outperforms BAM, CBAM, and SCSE, regardless of the selected backbone network. In particular, when employing ResNet101 as the backbone network, integrating the PSA module yields a 2.7% improvement over no attention, 2.3% over BAM, 2.4% over CBAM, and 2.1% over SCSE across the AP0.5-0.95 metric. We visualized prototype masks within YOLACT to elucidate the model's mechanism. Furthermore, we visualized the PSA attention to confirm its ability to capture valuable pig-related information. Additionally, we validated the transfer performance of our model on a top-down view dataset, affirming the robustness of the YOLACT model with the PSA module.

Hot-Exciton Mechanism and AIE Effect Boost the Performance of Deep-Red Emitters in Non-Doped OLEDs.

Luminescent materials possessing a "hot-exciton" mechanism and aggregation-induced emission (AIE) qualities are well-suited for use as emitting materials in nondoped organic light-emitting diodes (OLEDs), particularly in deep-red regions where their ground state and singlet excited state surfaces are in proximity, leading to the formation of multiple nonradiative channels. However, designing molecules that artificially combine the hot-exciton mechanism and AIE attributes remains a formidable task. In this study, a versatile strategy is presented to achieve hot-exciton fluorescence with AIE property by increasing the first singlet excited (S1 ) state through modulation of the conjugation length of the newly created acceptor unit, matching the energy level of high-lying triplet (Tn ) states, and enhancing exciton utilization efficiency by employing suitable donor moieties. This approach reduces the aggregation-caused quenching (ACQ) in the aggregate state, resulting in the proof-of-concept emitter DT-IPD, which produces an unprecedented external quantum efficiency (EQE) of 12.2% and Commission Internationale de I'Eclairage (CIE) coordinates of (0.69, 0.30) in a deep-red non-doped OLED at 685 nm, representing the highest performance among all deep-red OLEDs based on materials with hot-exciton mechanisms. This work provides novel insights into the design of more efficient hot-exciton emitters with AIE properties.

Observation of Rydberg moiré excitons.

Rydberg excitons, the solid-state counterparts of Rydberg atoms, have sparked considerable interest with regard to the harnessing of their quantum application potentials, but realizing their spatial confinement and manipulation poses a major challenge. Lately, the rise of two-dimensional moiré superlattices with highly tunable periodic potentials provides a possible pathway. Here, we experimentally demonstrate this capability through the spectroscopic evidence of Rydberg moiré excitons (XRM), which are moiré-trapped Rydberg excitons in monolayer semiconductor tungsten diselenide adjacent to twisted bilayer graphene. In the strong coupling regime, the XRM manifest as multiple energy splittings, pronounced red shift, and narrowed linewidth in the reflectance spectra, highlighting their charge-transfer character wherein electron-hole separation is enforced by strongly asymmetric interlayer Coulomb interactions. Our findings establish the excitonic Rydberg states as candidates for exploitation in quantum technologies.

Pioneering research on blue "hot exciton" polymers and their application in solution-processed organic light-emitting diodes.

An innovative novel category of polymeric hybridized local and charge-transfer (HLCT) blue materials prepared via solution processing has yet to be reported. This study introduces three polymers, namely PZ1, PZ2, and PZ3, incorporating donor-acceptor-donor (D-A-D) structures with carbazole functioning as the donor and benzophenone as the acceptor. To regulate the luminescence mechanism and conjugation length, carbonyl and alkyl chains are strategically inserted into the backbone. Theoretical calculation and transient absorption spectroscopy illustrate that the robust spin-orbit coupling between high-lying singlet excited states (Sm: m ⩽ 4) and triplet excited states (Tn: n ⩽ 7) of the polymers hastens and significantly heightens the efficiency of reverse intersystem crossing processes from Tn states. Furthermore, the existence of multiple degenerated frontier molecular orbits and significant overlaps between Tn and Sm states give rise to added radiative pathways that boost the radiative rate. This study marks a fundamental and initial manifestation of HLCT materials within the polymer field and provides a new avenue for the design of highly efficient polymeric emitters.

A meta-analysis of intravenous thrombolysis versus bridging therapy for ischemic stroke.

BACKGROUND: The purpose of this study was to perform a pooled analysis of randomized controlled trials (RCT) of intravenous thrombolysis (IVT) versus bridging therapy of intravenous thrombolysis and mechanical thrombectomy (IVMT), comparing the efficacy and safety of the two in patients with acute ischemic stroke (AIS). METHODS: All eligible RCT articles from database establishment to December 8, 2021 were searched in databases such as PubMed, Ovid, Embase, Web of science, Cochrane Library, etc. Efficacy outcomes were assessed by modified RANKIN scal (mRS) score, complete recanalization or reperfusion (TICI), National Institute of Health Stroke Scal (NIHSS) score, 90-day mortality, 24 to 36 h incidence of symptomatic intracranial hemorrhage (sICH). RESULTS: Our study included 6 RCT involving 1717 patients. The proportion of the primary efficacy outcome (mRS score 0-2 at 90 days) was significantly different between IVT and IVMT (OR 0.51; 95% CI 0.35-0.76). For the secondary efficacy outcome, the study found a significant difference in the proportion of TICI (pooled OR was 0.055, 95% CI 0.07-0.33). There was a significant difference in the 24 h NIHSS score between the IVT group and the IVMT group (pooled MD was 3.25, 95% CI 0.80-5.70). There were no significant differences in the NIHSS score at 90 days, the death rate at 90 days, and the sICH at 24 to 36 hours between the two groups. CONCLUSIONS: This study confirms that IVMT is more effective and safe than IVT alone in patients with AIS. However, more and higher-quality randomized clinical trials comparing IVMT to IV alone are warranted for validation.

Radical annulation of a designed diene system: access to nitro-benzo[b]azepines.

Herein, we describe a novel O2N˙-triggered ordered addition 7-endo cyclization reaction with excellent chemo- and regioselectivity. With such a strategy, structurally diverse nitro-benzo[b]azepines were prepared with 28 examples. Large-scale operation and handy N-Ts and N-Cbz deprotection reveal the promising utility of this methodology. Mechanistic studies suggest that the reaction proceeds through a radical pathway.

Regioselective C6-H Hydroxyalkylation of Purines and Purine Nucleosides via α-C-H Functionalization of Alcohols at Room Temperature.

The highly regioselective C6-H hydroxylalkylation of purines and purine nucleosides within 10 min via the α-C(sp3)-H functionalization of alcohols at room temperature is reported here for the first time. The reaction tolerated various functional groups, which have the potential for further modification to afford other valuable molecules. The reported method avoids metal catalysts, light, and protecting groups, giving a direct strategy to access 6-substitued alkylated purines and nucleosides with pharmaceutical bioactivities.

Zhilong Huoxue Tongyu Capsules' Effects on ischemic stroke: An assessment using fecal 16S rRNA gene sequencing and untargeted serum metabolomics.

Zhilong Huoxue Tongyu capsule (ZHTC) is an effective traditional Chinese medicine compound for the treatment of ischemic stroke, which is widely used in clinical ischemic stroke patients. However, it is uncertain whether ZHTC affects ischemic stroke through gut microbiota and serum metabolites. In this study, a rat model of middle cerebral artery occlusion (MCAO) was prepared. By evaluating motor nerve function score, cerebral infarct size, brain tissue damage and intestinal barrier damage, it was found that ZHTC improved stroke-related symptoms in MCAO rats. Using 16S rRNA gene sequencing, fecal microbial transplantation (FMT), untargeted metabolomics, and spearman correlation analysis of gut microbiota and serum metabolites, we found that ZHTC can regulate the abundance of p_Firmicutes, p_Bacteroidota,p_Proteobacteria, g_Prevotella, and g_Lactobacillus, and regulated 23 differential metabolites. Spearman correlation analysis found that Arginine was positively correlated with p_Firmicutes, o_Clostridiales, c_Clostridia, and negatively correlated with p_Bacteroidetes, c_Bacteroidia,o_Bacteroidales; L-Lysine was negatively correlated with f_Christensenellaceae; L-methionine was positively correlated with o_Lactobacillales, f_Lactobacillaceae, and g_Lactobacillus. Altogether, this study shows for the first time that ZHTC can ameliorate ischemic stroke by modulating gut microbiota and metabolic disturbances. This lays the foundation for further revealing the causal relationship between ZHTC, gut dysbiosis, plasma metabolite levels and ischemic stroke, and provides a scientific explanation for the ameliorating effect of ZHTC on ischemic stroke.