Photocatalytic doping of organic semiconductors.

Chemical doping is an important approach to manipulating charge-carrier concentration and transport in organic semiconductors (OSCs)1-3 and ultimately enhances device performance4-7. However, conventional doping strategies often rely on the use of highly reactive (strong) dopants8-10, which are consumed during the doping process. Achieving efficient doping with weak and/or widely accessible dopants under mild conditions remains a considerable challenge. Here, we report a previously undescribed concept for the photocatalytic doping of OSCs that uses air as a weak oxidant (p-dopant) and operates at room temperature. This is a general approach that can be applied to various OSCs and photocatalysts, yielding electrical conductivities that exceed 3,000 S cm-1. We also demonstrate the successful photocatalytic reduction (n-doping) and simultaneous p-doping and n-doping of OSCs in which the organic salt used to maintain charge neutrality is the only chemical consumed. Our photocatalytic doping method offers great potential for advancing OSC doping and developing next-generation organic electronic devices.

A Highly Conductive n-Type Conjugated Polymer Synthesized in Water.

Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) is a benchmark hole-transporting (p-type) polymer that finds applications in diverse electronic devices. Most of its success is due to its facile synthesis in water, exceptional processability from aqueous solutions, and outstanding electrical performance in ambient. Applications in fields like (opto-)electronics, bioelectronics, and energy harvesting/storage devices often necessitate the complementary use of both p-type and n-type (electron-transporting) materials. However, the availability of n-type materials amenable to water-based polymerization and processing remains limited. Herein, we present a novel synthesis method enabling direct polymerization in water, yielding a highly conductive, water-processable n-type conjugated polymer, namely, poly[(2,2'-(2,5-dihydroxy-1,4-phenylene)diacetic acid)-stat-3,7-dihydrobenzo[1,2-b:4,5-b']difuran-2,6-dione] (PDADF), with remarkable electrical conductivity as high as 66 S cm-1, ranking among the highest for n-type polymers processed using green solvents. The new n-type polymer PDADF also exhibits outstanding stability, maintaining 90% of its initial conductivity after 146 days of storage in air. Our synthetic approach, along with the novel polymer it yields, promises significant advancements for the sustainable development of organic electronic materials and devices.

Ion-tunable antiambipolarity in mixed ion-electron conducting polymers enables biorealistic organic electrochemical neurons.

Biointegrated neuromorphic hardware holds promise for new protocols to record/regulate signalling in biological systems. Making such artificial neural circuits successful requires minimal device/circuit complexity and ion-based operating mechanisms akin to those found in biology. Artificial spiking neurons, based on silicon-based complementary metal-oxide semiconductors or negative differential resistance device circuits, can emulate several neural features but are complicated to fabricate, not biocompatible and lack ion-/chemical-based modulation features. Here we report a biorealistic conductance-based organic electrochemical neuron (c-OECN) using a mixed ion-electron conducting ladder-type polymer with stable ion-tunable antiambipolarity. The latter is used to emulate the activation/inactivation of sodium channels and delayed activation of potassium channels of biological neurons. These c-OECNs can spike at bioplausible frequencies nearing 100 Hz, emulate most critical biological neural features, demonstrate stochastic spiking and enable neurotransmitter-/amino acid-/ion-based spiking modulation, which is then used to stimulate biological nerves in vivo. These combined features are impossible to achieve using previous technologies.

Fecal calprotectin is a novel biomarker to predict the clinical outcomes of patients with ruptured intracranial aneurysm.

BACKGROUND: Intracranial aneurysm (IA) is a common cerebrovascular disease and the leading cause of spontaneous subarachnoid hemorrhage. Recent evidence suggests that gut microbiota is involved in the pathophysiological process of IA through the gut-brain axis. However, the role of gut inflammation in the development of IA has yet to be clarified. Our study aimed to investigate whether fecal calprotectin (FC) level, a sensitive marker of gut inflammation, is correlated with the development of IA and the prognosis of patients with ruptured IA (RIA). METHODS: 182 patients were collected from January 2022 to January 2023, including 151 patients with IA and 31 healthy individuals. 151 IA patients included 109 patients with unruptured IA (UIA) and 42 patients with RIA. The FC level was measured by enzyme-linked immunosorbent assay. Other detailed information was obtained from an electronic medical record system. RESULTS: Compared with healthy controls, the FC levels in patients with IA were increased (P < 0.0001). Patients with RIA had significantly higher FC levels than UIA patients (P < 0.0001). Moreover, the FC level in RIA patients with unfavorable outcomes was higher than in RIA patients with favorable outcomes. Logistic regression analysis showed that the elevated FC level was an independent risk factor for a 3-month poor prognosis in patients with RIA (OR=1.005, 95% CI = 1.000 -1.009, P = 0.044). CONCLUSION: Fecal calprotectin level is significantly elevated in IA patients, especially those with RIA. FC is a novel biomarker of 3-month poor outcomes in RIA patients.

An Online Survey on the Relationship Between Positive Coping and Post-Traumatic Stress Symptoms (PTSS) of Medical Students in China During the COVID-19 Pandemic: The Mediating Role of Social Support.

BACKGROUND The COVID-19 pandemic has caused varying degrees of psychological stress among medical students. This research explored the post-traumatic stress symptoms (PTSS) of medical students in China and their relationship with positive coping and social support. MATERIAL AND METHODS In the form of cross-sectional online survey, 2280 medical students locked down at home were selected by random cluster method to investigate social support, coping style, and PTSS using the Social Support Rating Scale (SSRS), Simplified Coping Style Questionnaire (SCSQ), and Post-traumatic Stress Disorder (PTSD) Checklist-Civilian Version (PCL-C), respectively. RESULTS This research found that the PTSS detection rate in medical students was 10.42% during the COVID-19 pandemic. The PTSS scores of females were significantly higher than that of the males. However, the PTSS detection rate in females (9.71%) was not significantly different from that in males (11.24%). Compared with those of the non-PTSS group, the total score and its all-factor score of social support, the total score of coping style and the positive coping score of the PTSS group were much lower, while the negative coping score of the PTSS group was much higher (P<0.01). Positive coping was positively correlated with social support, while positive coping and social support were negatively correlated with PTSS. The total effect of positive coping on PTSS was -0.310 (P<0.001), the direct effect was -0.128 (P<0.01), and the indirect effect was -0.182 (P<0.001). Social support played a mediating role between positive coping and PTSS, with the mediating effect accounting for 58.81% of the total effect. CONCLUSIONS Social support plays a mediating role between positive coping and post-traumatic stress symptoms. Objective support and positive coping are the 2 main protective factors of PTSS.

Synthesis and antimicrobial activity evaluation of pyrazole derivatives containing the imidazo[2,1-b][1,3,4]thiadiazole moiety.

Four series of novel pyrazole derivatives (compounds 17a-m, 18a-m, 19a-g, and 20a-g) were synthesized, and their antibacterial and antifungal activities were evaluated. Most of the target compounds (17a-m, 18k-m, and 19b-g) showed strong antifungal activity and high selectivity relative to both Gram-positive and Gram-negative bacteria. Among them, compounds 17l (minimum inhibitory concentration [MIC] = 0.25 µg/mL) and 17m (MIC = 0.25 µg/mL) showed the strongest antifungal activity, being 2- and 4-fold more active than the positive controls gatifloxacin and fluconazole, respectively. In particular, compound 17l showed little cytotoxicity against human LO2 cells and did not exhibit hemolysis at ultrahigh concentrations, as did the positive control compounds gatifloxacin and fluconazole. These results indicate that these compounds are valuable for further development as antifungal agents.

Research Progress on Estimation of Postmortem Interval Based on Ocular Tissues Structure.

Estimation of postmortem interval (PMI) is one of the important research contents in forensic pathology, and it has always been the focus and hot spot of research work. In recent years, scholars at home and abroad have made some research progress in estimating PMI by using ocular tissue. After death, the changes of cornea, aqueous humor, iris, lens, vitreous humor and retina all show time sequence change rule highly related to PMI. This paper reviews the research progress of PMI estimation based on the morphological, biochemical, molecular and genetic material changes of different ocular tissue structures after death, and discusses the existing problems and development trends.

Design and fabrication of high-performance multimode interferometer in lithium niobate thin film.

We propose and demonstrate a type of high-performance transverse magnetic (TM) multimode interferometer (MMI) in Z-cut thin film lithium niobate (TFLN). Both 1 × 2 and 4 × 4 MMI designs are demonstrated. Simulation results show that the insertion losses (ILs) are nominally about 0.157 and 0.297 dB for the 1 × 2 and 4 × 4 MMI, respectively, with wide fabrication tolerances. Based on the designed structure, the MMIs are fabricated using an argon based induced coupled plasma (ICP) etching method in Z-cut TFLN. The measured ILs are 0.268 and 0.63 dB for these two kinds of devices. The presented TM mode MMI featuring compact size and low loss can be used for both multifunctional devices and on-chip integrated circuits on a Z-cut TFLN platform.

3D chaos lidar system with a pulsed master oscillator power amplifier scheme.

We investigated the characteristics of chaos-modulated pulses amplified by a pulsed master oscillator power amplifier (MOPA) for application in a new chaos lidar system in this study. Compared with the loss modulation applied in a continuous-wave (CW) time-gating scheme, the pulsed MOPA scheme could generate chaos-modulated pulses with much higher peak power, resulting in an improved peak-to-standard deviation of sidelobe level (PSLstd) in correlation-based lidar detection. When the pulsed MOPA scheme was applied at a duty cycle of 0.1% and pulse repetition frequency of 20 kHz, which correspond to specifications compliant with eye safety regulations, it outperformed the CW time-gating scheme with respect to PSLstd by 15 dB. For the first time, we applied the chaos lidar system with the pulsed MOPA scheme to execute high-resolution, high-precision three-dimensional (3D) face profiling from a distance of 5 m. We also added the corresponding PSLstd value to each pixel in the point clouds to generate false-color images; thus, we obtained 3D images of a scene with multiple objects at a range of up to 20 m.

Generations of chaos-modulated pulses based on a gain-switched semiconductor laser subject to delay-synchronized optical feedback for pulsed chaos lidar applications.

We generate and analyze chaos-modulated pulses based on a gain-switched semiconductor laser subject to delay-synchronized optical feedback for pulsed chaos lidar applications. Benefited by the aperiodic and uncorrelated chaos waveforms, chaos lidar possesses the advantages of no range ambiguity and immunity to interference and jamming. To improve the detection range while in compliance with the eye-safe regulation, generating chaos-modulated pulses with higher peak power rather than chaos in its CW form is desired. While using an acousto-optic modulator to time-gate the CW chaos into pulses could be lossy and energy inefficient, in this paper, we study the generation of chaos-modulated pulses using a gain-switched laser subject to delay-synchronized optical feedback. Under different feedback strengths and modulation currents of gain-switching, we investigate the quality of the chaos-modulated pulses generated by analyzing their ratio of chaos oscillations, peak sidelobe levels (PSLs), and cross-correlation peaks under different mismatching conditions between the pulse repetition interval (PRI) and the feedback time delay τ. With proper feedback strengths and modulation currents, we find that synchronizing the gain-switching modulation with the delayed feedback (PRI = τ) is essential in generating the chaos-modulated pulses suitable for the pulsed chaos lidar applications. When mismatching occurs, we identify sequences of dynamical periods including stable, periodic, and chaos oscillations evolved within a pulse.

High pulsed power VCSEL arrays with polymer microlenses formed by photoacid diffusion.

We demonstrate millimeters-long VCSEL linear arrays with SU-8 epoxy-based microlenses that are directly patterned and cross-linked on the output apertures by a simple, photoacid-diffusion-aided photolithography technique. The linear arrays are capable of delivering >7 W of peak pulsed output power. By exploiting the photoacid diffusion effect, it is possible to produce a range of microlens structures with height and radius of curvature ranging from approximately ten to tens of microns. Simulation and experimental results show that the far-field beam divergence can be reduced by a factor of up to 7 in VCSELs integrated with optimal microlens dimensions.

3D pulsed chaos lidar system.

We develop an unprecedented 3D pulsed chaos lidar system for potential intelligent machinery applications. Benefited from the random nature of the chaos, conventional CW chaos lidars already possess excellent anti-jamming and anti-interference capabilities and have no range ambiguity. In our system, we further employ self-homodyning and time gating to generate a pulsed homodyned chaos to boost the energy-utilization efficiency. Compared to the original chaos, we show that the pulsed homodyned chaos improves the detection SNR by more than 20 dB. With a sampling rate of just 1.25 GS/s that has a native sampling spacing of 12 cm, we successfully achieve millimeter-level accuracy and precision in ranging. Compared with two commercial lidars tested side-by-side, namely the pulsed Spectroscan and the random-modulation continuous-wave Lidar-lite, the pulsed chaos lidar that is in compliance with the class-1 eye-safe regulation shows significantly better precision and a much longer detection range up to 100 m. Moreover, by employing a 2-axis MEMS mirror for active laser scanning, we also demonstrate real-time 3D imaging with errors of less than 4 mm in depth.

Ratiometric Detection of ß-Amyloid and Discrimination from Lectins by a Supramolecular AIE Glyconanoparticle.

While the development of AIE (aggregation-induced-emission) based fluorimetric probes for biological applications has been an active research area, probes with a ratiometric signal for biomolecular recognition have been rare. Here, a ratiometric AIE glyconanoparticle formed by the supramolecular assembly between a silole-based AIEgen and fluorescent glycoprobes for the detection of amyloid ß (Aß) peptides and fibrils, which are a signature of neurological disorders such as the Alzheimer's disease, is shown. Complexation of glycoprobes with the AIEgen produces an intensive fluorescence emission of the former because of a Förster resonance energy transfer between the two molecules. Subsequently, the presence of Aß dissembles the particle, producing a fluorescence emission of the AIEgen. Interestingly, the addition of lectins that selectively recognize the glycoprobes results in a different ratiometric response of the particle, thereby enabling a discrimination from Aß detection. This research offers insight into the simple construction of multifunctional ratiometric probes based on the supramolecular hybridization of a wide variety of AIEgens with fluorescent molecular probes.

[Construction of ecological network with protected areas as the main region in Guangzhou City, China]. / 以自然保护地为主体的广州市域生态网络构建.

In the context of the national ecological security development strategy, constructing regional ecological networks centered on protected areas and ecological corridors has become an urgent issue in protected areas system development of China. We focused on strengthening ecological connections between protected areas in Guangzhou, identified the ecological resource patches, ecological corridors, and ecological nodes by using Invest model, connectivity analysis, circuit theory models, and graph-theoretical network structure evaluation, and constructed an ecological network for the Guangzhou with nature reserves as the core. The results showed that 52 ecological resource patches were identified in the study area, covering a total area of 1450.01 km2. Nature reserves accounted for 76.4% of the total area, forming the main part of the ecological resource patches. 115 ecological corridors were identified, with a total length of 900.56 km and an average length of 7.83 km. Furthermore, 72 ecological key points were identified, covering a total area of 17.57 km2, and 81 ecological breakpoints, with a total area of 35.9 km2. The network structure indices (α=0.65, ß=2.21, and γ=0.77) indicated a reasonably structured and well-connected network. By exploring pathways for constructing regional ecological networks under the protected areas system and enriching the application of circuit theory models in ecological network construction, this study provides scientific basis for regional ecological security and biodiversity conservation.

Genetic variation analysis of Guanling cattle based on whole-genome resequencing.

Objective: The objective of this study was to unravel the genetic traits of Guanling cattle, pinpoint genes advantageous for muscle growth, and lay a foundation for the preservation of genetic diversity and further analysis of regulation mechanism of important economic traits in local cattle breed. Methods: In this study, we sequenced the whole genome of 3 Guanling cattle in Guizhou province using the Illumina HiSeq cBo sequencing platform. And, high- multiplex PCR technology was employed to detect high-quality SNP sites of other 55 Guanling cattle. Results: Our study identified 166,411 non-synonymous SNPs (nsSNPs) and 42,423 insertions and deletions (indels). Through SNP annotation, gene function enrichment analysis, and comparing with Simmental, Angus, and Limousin cattle, we identified six genes (LEPR, AKAP9, SIX4, SPIDR, PRG4, FASN) which are potentially influential on meat quality traits, playing crucial roles in muscle growth, fat metabolism, and bodily support. We also examined polymorphisms at seven SNP sites in Guanling cattle and found that all seven were in Hardy-Weinberg equilibrium. Conclusion: These findings suggested that these gene sites are stable and widespread in the Guanling cattle population. Our research lays the groundwork for future genetic enhancement and variety identification of Guanling cattle.

Interleukin-10-alveolar macrophage cell membrane-coated nanoparticles alleviate airway inflammation and regulate Th17/regulatory T cell balance in a mouse model.

Background: Allergic airway disease (AAD) is a chronic disease characterized by airway inflammation, bronchoconstriction, and hyperresponsiveness. Although exogenous interleukin-10 (IL-10) alleviates allergic inflammation, it has a short half-life in vivo. Cell membrane-coated nanomaterials have been shown to protect therapeutic payloads and increase therapeutic efficacy. Objective: This study was aimed at investigating the efficacy of a novel macrophage-based nanoparticle drug for the treatment of house dust mite (HDM)-induced allergic airway diseases. Methods: IL-10-poly (lactic-co-glycolic acid (PLGA) nanoparticles were encapsulated in alveolar macrophage cell membranes. An allergic airway disease mouse model was established by repeated inhalation of HDM extracts. The mice were treated with free IL-10, IL-10-PLGA nanoparticles (IL10-NP), or IL-10-alveolar macrophage cell membrane-coated nanoparticles (IL10-AMNP). The therapeutic effects were evaluated by measuring airway hyperresponsiveness, lung inflammation, cytokine levels, and regulatory T cells (Treg)- T-helper 17 (Th17) cell balance. Results: Compared to free IL-10, IL10-AMNP significantly reduced airway hyperresponsiveness and T-helper 2 (Th2)/Th17 cytokines and inhibited neutrophilia and eosinophilia recruitment into the airways of HDM-induced mouse models. Additionally, the balance between Tregs and Th17 cells was significantly improved in groups treated with IL10-AMNP. Conclusion: This study demonstrated that PLGA nanoparticle cores coated with alveolar macrophage cell membranes can effectively deliver therapeutic cytokines to the lungs and improve the homeostatic balance between Tregs and Th17 cells. These findings suggest that macrophage-based nanoparticle drugs represent a promising approach for treating allergic airway diseases.

Modified extended object tracker for 2D lidar data using random matrix model.

The random matrix (RM) model is a typical extended object-modeling method that has been widely used in extended object tracking. However, existing RM-based filters usually assume that the measurements follow a Gaussian distribution, which may lead to a decrease in accuracy when the filter is applied to the lidar system. In this paper, a new observation model used to modify an RM smoother by considering the characteristics of 2D LiDAR data is proposed. Simulation results show that the proposed method achieves a better performance than the original RM tracker in a 2D lidar system.

[Geochemical Background and Baseline Value of Soil Chemical Elements in Hebei Province].

Geochemical background and baseline values are important parameters for understanding the geochemical characteristics of soil elements, but the research degree of these two parameters is lacking in Hebei Province. Therefore, data from the multi-purpose regional geochemical survey and land quality geochemical assessment in Hebei Province from 2004 to 2018 were collected, covering approximately 71% of the land area of the whole province. Based on the data of surface soil and deep soil, scientific and robust methods including median value and median absolute deviation were used to calculate the geochemical background values, geochemical baseline values, as well as variation ranges of 54 indexes (Ag, Al2O3, As, Au, B, Ba, Be, Bi, Br, CaO, Cd, Ce, Cl, Co, Cr, Cu, F, Fe2O3, Ga, Ge, Hg, I, K2O, La, Li, MgO, Mn, Mo, N, Na2O, Nb, Ni, P, Pb, pH, Rb, S, Sb, Sc, Se, SiO2, Sn, Sr, Th, Ti, Tl, U, V, W, Y, Zn, Zr, total carbon (TC), and organic carbon (Corg)) in Hebei Province and 11 prefecture-level cities. The change rate in geochemical background for each index was also calculated. The results showed that the geochemical background and baseline values of most soil chemical elements in Hebei Province were lower than those nationwide, but the values of Ba, Br, Cl, MgO, Na2O, P, pH, S, Sr, and TC were higher, with CaO being the highest. Compared with those in north China, there was no significant difference in the geochemical background and baseline values for the 54 indexes, with the ratios of 0.83-1.17 and 0.79-1.19, respectively. Significant changes in the geochemical background for Corg, Hg, N, P, S, and Se were observed in Hebei Province, indicating that these indexes were greatly influenced by human factors. Preliminary analysis suggests that coal burning emissions and agricultural chemical use were two very important inducing factors.

Bimetallic oxide Cu2O@MnO2 with exposed phase interfaces for dual-effect purification of indoor formaldehyde and pathogenic bacteria.

The combination of materials with different functions is an optimal strategy for synchronously removing various indoor pollutants. For multiphase composites, exposing all components and their phase interfaces fully to the reaction atmosphere is a critical problem that needs to be solved urgently. Here, a bimetallic oxide Cu2O@MnO2 with exposed phase interfaces was prepared by a surfactant-assisted two-step electrochemical method, which shows a composite structure of non-continuously dispersed Cu2O particles anchored on flower-like MnO2. Compared with the pure catalyst MnO2 and bacteriostatic agent Cu2O, Cu2O@MnO2 respectively shows superior dynamic formaldehyde (HCHO) removal efficiency (97.2% with a weight hourly space velocity of 120 000 mL g-1 h-1) and pathogen inactivation ability (the minimum inhibitory concentration for 104 CFU mL-1 Staphylococcus aureus is 10 µg mL-1). According to material characterization and theoretical calculation, its excellent catalytic-oxidative activity is attributable to the electron-rich region at the phase interface which is fully exposed to the reaction atmosphere, inducing the capture and activation of O2 on the material surface, and then promoting the generation of reactive oxygen species that can be used for the oxidative-removal of HCHO and bacteria. Additionally, as a photocatalytic semiconductor, Cu2O further enhances the catalytic ability of Cu2O@MnO2 under the assistance of visible light. This work will provide efficient theoretical guidance and a practical basis for the ingenious construction of multiphase coexisting composites in the field of multi-functional indoor pollutant purification strategies.

Modified Distributed Bragg Reflectors for Color Stability in InGaN Red Micro-LEDs.

The monolithic integration of InGaN-based micro-LEDs is being of interest toward developing full-color micro-displays. However, the color stability in InGaN red micro-LED is an issue that needs to be addressed. In this study, the modified distributed Bragg reflectors (DBRs) were designed to reduce the transmission of undesired spectra. The calculated optical properties of the InGaN red micro-LEDs with conventional and modified DBRs have been analyzed, respectively. The CIE 1931 color space and the encoded 8-bit RGB values are exhibited for the quantitative assessment of color stability. The results suggest the modified DBRs can effectively reduce the color shift, paving the way for developing full-color InGaN-based micro-LED displays.