Expert consensus on One Health for establishing an enhanced and integrated surveillance system for key infectious diseases.

China has been continuously improving its monitoring methods and strategies to address key infectious diseases (KIDs). After the severe acute respiratory syndrome epidemic in 2003, China established a comprehensive reporting system for infectious diseases (IDs) and public health emergencies. The relatively lagging warning thresholds, limited warning information, and outdated warning technology are insufficient to meet the needs of comprehensive monitoring for modern KIDs. Strengthening early monitoring and warning capabilities to enhance the public health system has become a top priority, with increasing demand for early warning thresholds, information, and techniques, thanks to constant innovation and development in molecular biology, bioinformatics, artificial intelligence, and other identification and analysis technologies. A panel of 31 experts has recommended a fourth-generation comprehensive surveillance system targeting KIDs (41 notifiable diseases and emerging IDs). The aim of this surveillance system is to systematically monitor the epidemiology and causal pathogens of KIDs in hosts such as humans, animals, and vectors, along with associated environmental pathogens. By integrating factors influencing epidemic spread and risk assessment, the surveillance system can serve to detect, predict, and provide early warnings for the occurrence, development, variation, and spread of known or novel KIDs. Moreover, we recommend comprehensive ID monitoring based on the fourth-generation surveillance system, along with a data-integrated monitoring and early warning platform and a consortium pathogen detection technology system. This series of considerations is based on systematic and comprehensive monitoring across multiple sectors, dimensions, factors, and pathogens that is supported by data integration and connectivity. This expert consensus will provides an opportunity for collaboration in various fields and relies on interdisciplinary application to enhance comprehensive monitoring, prediction, and early warning capabilities for the next generation of ID surveillance. This expert consensus will serve as a reference for ID prevention and control as well as other related activities.

Effects of albiflorin on oxidative stress and inflammatory responses in rats with acute spinal cord injury.

INTRODUCTION: Oxidative stress and inflammatory responses are often the predominant detrimental factors associated with spinal cord injury (SCI). This study investigates the potential therapeutic effects of albiflorin (AF) on alleviating inflammation and oxidative stress in the rat model with SCI. METHODS: Initially, the behavior of SCI-induced rats is examined by Basso-Beattie-Bresnahan score and the inclined plane examination. Then, the immunohistochemical staining of inflammasome-related protein (for instance, NACHT, LRR, and PYD domains-containing protein 3, NLRP3) is performed in combination with enzyme-linked immunosorbent assay (ELISA) of corresponding proinflammatory factors to assess the immunomodulatory effects of AF. Further, the markers involved in oxidative stress are examined by ELISA and western blot analysis analyses. RESULTS: These findings indicated that AF could alleviate motor dysfunction and the loss of neuron cells in SCI-induced rats. Mechanistically, AF could attenuate the inflammatory responses by reducing oxidative stress and activating nuclear erythroid-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) pathway in SCI rats. Depleting the antioxidant capacity by inhibiting glutathione biosynthesis could counteract the anti-inflammatory activity of AF in SCI rats. CONCLUSIONS: Together, our data suggested that AF could serve as a potential therapeutic agent against the aggravation of SCI in rats.

DNAJB7 is dispensable for male fertility in mice.

BACKGROUND: DNAJBs are highly conserved proteins that are involved in various biological processes. Although several DNAJBs are highly expressed in the testis, the function of DNAJB7 in spermatogenesis and male fertility remains unclear. METHODS: To identify the role of DNAJB7 in the male reproduction process, Dnajb7-deficient mice were generated by the CRISPR/Cas9-mediated genome editing system. Histological and immunofluorescence assays were performed to analyze the phenotype of the Dnajb7 mutants. RESULTS: DNAJB7 is specifically expressed in haploid germ cells. Dnajb7 knockout mice are fertile and do not have any detectable defects in Sertoli cells, spermatogonia, meiotic and postmeiotic cells, indicating that DNAJB7 is not essential for spermatogenesis. CONCLUSIONS: Our findings suggest that DNAJB7 is dispensable for male fertility in mice, which could prevent duplicative work by other groups.

Association between sleep-wake schedules and myopia among Chinese school-aged children and adolescents: a cross-sectional study.

BACKGROUND: This study aimed to investigate the relationship between sleep-wake schedules and self-reported myopia in the pediatric population. METHODS: In this cross-sectional study in 2019, school-aged children and adolescents in the Baoan District of Shenzhen City were sampled using a stratified cluster sampling approach. Sleep-wake schedules of children were determined by a self-administered questionnaire. The age that participants first reported using myopia correction glasses or contact lenses was used to identify those with myopia. Pearson χ2 test was used to examine differences in myopia prevalence among participants with different characteristics. Multivariate logistic regression, adjusted for potential confounding variables, was applied to examine the relationship between sleep-wake schedule and risk of self-reported myopia, and a stratification analysis by school grade was also performed. RESULTS: A total of 30,188 students were recruited. In this study, the overall prevalence of myopia was 49.8%, with prevalence rates of 25.6%, 62.4%, and 75.7% for primary, junior high, and senior high school students, respectively. Students with irregular sleep-wake times reported a higher prevalence of myopia than those with regular sleep-wake times. Nighttime sleep duration of < 7 hours/day (h/d) (OR = 1.27, 95%CI: 1.17-1.38), no daytime nap (OR = 1.10, 95%CI: 1.03-1.18), irregular weekday bedtime (OR = 1.11, 95%CI: 1.05-1.17), irregular weekday wake time (OR = 1.21, 95%CI: 1.12-1.30), weekend bedtime delayed > = 1 h/d (OR = 1.20, 95%CI: 1.11-1.29, P < 0.001), weekend wake time delayed > = 1 h/d (OR = 1.11, 95%CI: 1.03-1.19), irregular sleep-wake time on weekdays (OR = 1.13, 95%CI: 1.07-1.19), and social jetlag > = 1 h (OR = 1.08, 95%CI: 1.03-1.14) were likely to be associated with increased risks of self-reported myopia after adjusting age, sex, grade, parental education level, family income, parental myopia, academic record, and academic workload. When stratified by school grade, we observed that nighttime sleep duration < 7 h/d, no daytime naps, and irregular sleep-wake time on weekdays were significantly associated with self-reported myopia in primary school students. CONCLUSION: Insufficient sleep and irregular sleep-wake schedules can increase the risk of self-reported myopia in children and adolescents.

Relationship between anthropometric parameters and 20 meter shuttle run test among children and adolescents / 中国学校卫生

Objective@#To determine the association between anthropometric parameters and 20 meter shuttle run test (20 m SRT) score among children and adolescents.@*Methods@#The convenient sampling method was conducted to select 3 192 primary and secondary school students in Baoan District, Shenzhen, based on the street school types school from April to May 2019. Height, weight, 20 m SRT score and general demographic indicators were assessed and collected. Individuals were divided into two groups based on the dose response correlation between different anthropometric parameters (the Z score of height, weight and BMI) and 20 m SRT score analyzed with the restricted cubic spline. The association between the Z score of height and 20 m SRT score was further analyzed using the Spearman correlation analysis. Logistic regression analysis was used to analyze separately the relationship different anthropometric parameters and 20 m SRT score.@*Results@#The Z value of weight and 20 m SRT score showed a non linear dose response association ( P <0.01), the significant but weak linear correlation between the Z value of height and 20 m SRT score ( r=0.06, P <0.05). The prevalence rate on the low level of the Z value of 20 m SRT score in 3 192 children and adolescents was 44.7%, and the gender ( χ 2=14.02, P <0.01) and grade difference ( χ 2=93.28, P <0.01) were both statistically significant. There was no significant relationship between the Z value of height and 20 m SRT score grade among total population, different genders and different grades ( P > 0.05). Compared with the reference group on the Z value of weight ≤-0.23, individuals with the Z value of weight >-0.23 had the low level of 20 m SRT score ( OR =0.61, P <0.05). Compared with the reference group on the Z value of BMI ≤ 0.25, individuals with the Z value of weight >0.25 had the low level of 20 m SRT score ( OR =0.45, P <0.05). Stratified for gender and grade, the above significant relationship on the Z value of weight, Z value of BMI and 20 m SRT score were still observed ( P <0.01).@*Conclusions@#The higher height Z value shows on correlations with 20 m SRT score, but the positive association is found between weight and BMI Z value and the 20 m SRT score. The cardiopulmonary fitness improvement may be more effective among children and adolescents when tuking weight and BMI Z scores into consideration.

Establishment of a concise health index synthetic evaluation method for adolescents / 中国学校卫生

Objective@#The aim of this study was to establish a comprehensive concise health index (CHI) for evaluating adolescents, so as to provide a basis for determining the overall health status of adolescents in China.@*Methods@#On the basis of a literature review and consensus among core researchers, adolescent CHI indicators in the following five dimensions were assessed:physical growth, physical fitness, common diseases, mental health and behavioral health. A total of 24 experts used an analysis hierarcgy process (AHP) to calculate the indicators subjective weights. In addition, from October to December of 2021, two regions, A and B were selected to conduct empirical research, and the CRITIC method was used to calculate the objective weights of the indicators. Finally, the weight coefficients were determined through the AHP-CRITIC combination weight method, and comprehensive evaluation was performed with the TOPSIS method.@*Results@#Across academic period and genders, the combined weighted coefficients of the health indicators were as follows:BMI, 0.081-0.095; waist circumference, 0.070-0.081; relative grip strength, 0.101-0.108; myopia, 0.110-0.128; dental caries, 0.055-0.070; psychological symptoms, 0.240-0.262; physical exercise, 0.085-0.115; screen time, 0.097-0.111; and sleep duration, 0.086-0.103. The health index of middle school students in city A (0.626±0.065) was significantly higher than that in city B(0.613±0.066)( t=6.34, P <0.01).@*Conclusion@#The comprehensive adolescent CHI evaluation method has good consistency and application value, and may serve as a reference for adolescent health monitoring.

Supplier concentration and corporate innovation input.

This paper studies the relationship between supplier concentration and corporate innovation input. The results show that a firm with a higher supplier concentration tends to have lower R&D investments and invention patents. Considering endogenous problems, this negative relationship is still robust by using the instrumental variable regression and propensity score matching method. Mechanism analysis shows that a firm with higher supplier concentration is impaired risk-taking capacity and occupied resources by the big suppliers. Our evidence shows that a deeper exposure to a small set of large supplier bears negative consequences for the firm. This paper sheds new light on the dark side of a high level of supplier concentration on corporate innovation.

Electrophysiological correlates of masked orthographic and phonological priming in Chinese-English bilinguals.

Extensive behavioral and electrophysiological evidence has demonstrated that native translations are automatically activated when bilinguals read non-native words. The present study investigated the impact of cross-language orthography and phonology on Chinese-English bilingual lexicons with a masked priming paradigm. The masked primes and targets were either translation equivalents (TE), orthographically related through translation (OR), phonologically related through translation (PR), or unrelated control (UC). Participants retained the targets in memory and decided whether the delayed catch words matched the targets. ERP data showed significant masked translation priming effects, as reflected by decreased ERP amplitudes in the TE condition in the 300-600 ms time window from frontal to parietal electrode clusters. Importantly, compared with the UC condition, the PR rather than OR condition elicited less negative ERP waveforms in the 300-500 ms time window with a frontal distribution. Taken together, these temporal and spatial dynamics suggested an automatic cross-language co-activation at the phonological and semantic levels for different-script bilinguals.

A regulatory perspective on recombinant collagen-based medical devices.

As a class of novel biomaterials manufactured by synthetic biology technologies, recombinant collagens are candidates for a variety of medical applications. In this article, a regulatory scientific perspective on recombinant collagens and their medical devices is presented with a focus on the definition, translation, classification and technical review. Recombinant collagens are categorized as recombinant human collagen, recombinant humanized collagen and recombinant collagen-like protein, as differentiated by specific compositions and structures. Based on their intended uses and associated risks, recombinant collagen-based medical devices are generally classified as Class Ⅱ or Ⅲ in China. The regulatory review of recombinant collagen-based medical devices aims to assess their safety and efficacy demonstrated by scientific evidences generated from preclinical and clinical evaluations. Taken together, opportunities as well as challenges for their future clinical translation of recombinant collagen-based medical devices abound, which highlights the essential role of regulatory science to provide new tools, standards, guidelines and methods to evaluate the safety and efficacy of medical products.

Prediction of Prognostic Factors and Genotypes in Patients With Breast Cancer Using Multiple Mathematical Models of MR Diffusion Imaging.

PURPOSE: To explore the clinical value of apparent diffusion coefficient (ADC), intravoxel incoherent motion (IVIM), and diffusion kurtosis imaging (DKI) based on diffusion-weighted MRI (DW-MRI) for predicting genotypes and prognostic factors of breast cancer. MATERIALS AND METHODS: A total of 227 patients with breast cancer confirmed by pathology were reviewed retrospectively. Diffusion-weighted imaging (DWI), IVIM, and DKI were performed in all patients. The corresponding ADC, true diffusion coefficient (D), perfusion-related diffusion coefficient (D*), perfusion fraction (f), mean diffusion rate (MD), and mean kurtosis value (MK) were measured. Multivariate logistic regression analysis and receiver operating characteristic (ROC) curve were used to analyze the diagnostic efficacy in predicting the Nottingham prognostic index (NPI), the expression of antigen Ki-67, and the molecular subtypes of breast cancer. The nomogram of the combined genotype-prediction model was established based on the multivariate logistic regression model results. RESULTS: D* and MK values were significantly higher in the high-grade Nottingham group (NPI ≥ 3.4) than the low-grade Nottingham group (NPI < 3.4) (p < 0.01). When D* ≥ 30.95 × 10-3 mm2/s and MK ≥ 0.69, the NPI tended to be high grade (with areas under the curve (AUCs) of 0.712 and 0.647, respectively). The combination of D* and MK demonstrated the highest AUC of 0.734 in grading NPI with sensitivity and accuracy of 71.7% and 77.1%, respectively. Additionally, higher D*, f, and MK and lower ADC and D values were observed in the high Ki-67 than low Ki-67 expression groups (p < 0.05). The AUC of the combined model (D + D* + f + MK) was 0.755, being significantly higher than that of single parameters (Z = 2.770~3.244, p = 0.001~0.006) in distinguishing high from low Ki-67 expression. D* and f values in the Luminal A subtype were significantly lower than in other subtypes (p < 0.05). Luminal B showed decreased D value compared with other subtypes (p < 0.05). The HER-2-positive subtype demonstrated increased ADC values compared with the Luminal B subtype (p < 0.05). Luminal A/B showed significantly lower D, D*, MD, and MK than the non-Luminal subtypes (p < 0.05). The combined model (D + D* + MD + MK) showed an AUC of 0.830 in diagnosing the Luminal and non-Luminal subtypes, which is significantly higher than that of a single parameter (Z = 3.273~4.440, p < 0.01). f ≥ 54.30% [odds ratio (OR) = 1.038, p < 0.001] and MK ≥ 0.68 (OR = 24.745, p = 0.012) were found to be significant predictors of triple-negative subtypes. The combination of f and MK values demonstrated superior diagnostic performance with AUC, sensitivity, specificity, and accuracy of 0.756, 67.5%, 77.5%, and 82.4%, respectively. Moreover, as shown in the calibration curve, strong agreements were observed between nomogram prediction probability and actual findings in the prediction of genotypes (p = 0.22, 0.74). CONCLUSION: DWI, IVIM, and DKI, as MR diffusion imaging techniques with different mathematical models showed potential to identify the prognosis and genotype of breast cancer. In addition, the combination of these three models can improve the diagnostic efficiency and thus may contribute to opting for an appropriate therapeutic approach in clinic treatment.

Lipidomic biomarkers: Potential mediators of associations between urinary bisphenol A exposure and colorectal cancer.

Previous research reported associations between bisphenol A (BPA) exposure and some malignant tumor incidences, yet the underlying mechanism remains largely uncertain. This investigation was aimed to explore the association of BPA exposure burden with colorectal cancer (CRC) and the role of tumor tissue lipid metabolism in the associations between BPA and CRC using lipidomic approach. Urinary BPA levels in CRC cases were significantly higher than those in controls (P value < 0.05). BPA was positively correlated with all three serum CRC biomarkers, with an estimated odds ratio (OR) of 4.45 (95% confidence interval (95% CI): [1.31, 15.14]) between the highest and lowest tertiles of exposure. Lipidomic screening of tumor samples suggested significant perturbation in the glycerophospholipid metabolism pathway, of which phosphatidylcholine (PC 34:0), phosphatidylcholine (PC 37:1), phosphatidylethanolamine (PE 34:2), triacylglycerol (TG 56:4) demonstrated mediation contribution of 21.9%, 18.7%, 18.4% and 27.39%, respectively, in the association between BPA exposure and CRC. Our work provides novel findings that cancer tissue metabolites may be playing vital mediating roles in the associations between BPA exposure burden and CRC risk. These findings contribute to better understanding of the etiology of CRC induced by environmental stressors.

Supply chain concentration and corporate financialization.

We investigate whether firms that rely on major suppliers or customers, which is defined as supply chain concentration, tend to hold more financial assets than other firms due to supply chain pressure. We find that firms with a higher supply chain concentration have a higher financialization level. The firms' competitive power reduces their financialization level but cannot reverse the adverse impact of supply chain concentration. Furthermore, we explore the mechanism underlying the relationship between supply chain concentration and corporate financialization using the mediation effect method. We find that supply chain concentration impairs firms' main business profitability, leading firms to hold more financial assets. The main business profitability channels play partial mediating roles. Our findings reveal that overdependence on large suppliers/customers causes firms to escape reality and adopt virtual economics.

Lead-Free Perovskite Photodetectors: Progress, Challenges, and Opportunities.

State-of-the-art photodetectors which apply hybrid perovskite materials have emerged as powerful candidates for next-generation light sensing. Among them, lead-based ones are the most popular beyond doubt on account of their unique and superior optoelectronic properties. Nevertheless, trade-off toward commercialization exists between nontoxicity and high performance, with the poor stability of lead-based perovskites, indicating that it is indispensable to substitute lead with nontoxic element meanwhile bringing about a comparable figure of merit of photodetectors and relatively long-term stability. Herein, recent advances in lead-free perovskite photodetectors are reviewed, analyzing the principle while designing new materials and highlighting some remarkable progress, which are comparable, even superior, to lead-based photodetectors. Furthermore, their potential strategy in optical communication, image sensing, narrowband photodetection, etc., is examined and a perspective on developing new materials and photodetectors with superior properties for more practical applications is provided.

The Clinical Characteristics of Endometrial Cancer With Extraperitoneal Metastasis and the Value of Surgery in Treatment.

OBJECTIVE: To describe the clinical and pathological features of endometrial carcinoma with extraperitoneal metastasis and examine whether surgery could improve the prognosis. METHODS: The Surveillance, Epidemiology, and End Results database was used to analyze 730 patients who were diagnosed with extraperitoneal metastasis of endometrial cancer from 2010 to 2015, including metastasis to the lung, bone, or brain. RESULTS: Of the 730 patients, 372 (50.96%) patients had single lung metastases, and 196(26.85%) patients had multiple organ metastases that included pulmonary invasion. Therefore, the lung was the most common target organ for extraperitoneal metastasis of endometrial cancer. In multivariate risk factor analysis, grade 3 tumor (odds ratio = 3.39, P < .001), positive peritoneal cytology (odds ratio = 2.02, P < .001), and cervical stromal invasion (odds ratio = 1.42, P = .030) were independent risk factors for extraperitoneal metastasis. Once metastasis occurred in the brain or multiple organs, the prognosis was often poor. Of the patients, 362 underwent surgery, and surgery was performed only for primary tumors of the reproductive organs in almost all patients (97.23%) with extraperitoneal metastasis. The median cancer-specific survival periods of patients with solitary pulmonary metastasis undergoing surgery and those without surgery were 23 (16.43-29.57) months and 9 (6.21-11.79) months, respectively (P < .001), and survival superiority also existed in patients with bone metastasis (19 vs 8 months, P = .015) and multiple organs metastases (15 vs 4 months, P < .001). However, patients with brain metastasis had the same median survival period in the 2 groups (6 months, P = .146). CONCLUSIONS: The lung was the most common target organ for extraperitoneal metastasis in patients with endometrial cancer. Surgery was associated with improved survival in women with extraperitoneal metastasis, except for patients with brain metastasis.

Analysis of immune-related signatures of colorectal cancer identifying two different immune phenotypes: Evidence for immune checkpoint inhibitor therapy.

Immune checkpoint inhibitor (ICI) therapy has revolutionized the treatment of numerous types of cancer, including colorectal cancer (CRC). Patients with CRC and deficient mismatch repair or high microsatellite instability could benefit from ICI treatment, although the response rate of most patients is low. Therefore, the immune subtyping of patients with CRC is required in order to determine the subtypes suitable for ICI treatment. The present study used a cohort of patients with CRC from The Cancer Genome Atlas (TCGA) to perform molecular subtyping, with results validated in three CRC cohorts from the Gene Expression Omnibus. Non-negative matrix factorization was used to achieve consensus molecular subtyping. The tumor immune dysfunction and exclusion algorithm was used to predict potential ICI therapy responses and gene set enrichment analysis was performed to define different pathways associated with the immune response. Two distinct subtypes of CRC were finally identified in TCGA cohorts, which were characterized as significantly different prognostic subtypes (low-risk and high-risk subtypes). Higher expression of programmed death-ligand 1, higher proportion of tumor-infiltrating lymphocytes and tumor mutation burden were significantly enriched in the low-risk subtype. Further pathway analysis revealed that the low-risk subtype was associated with immune response activation and signaling pathways involved in 'antigen processing and presentation'. Three independent CRC cohorts were used to validate the above findings. In summary, two clinical CRC subtypes were identified, which are characterized by significantly different survival outcomes and immune infiltration patterns. The findings of the present study suggest that ICI treatment may be more effective in the low-risk CRC subtype.

Photonic millimeter-wave ultrawideband signal generation using frequency upconversion based on the stimulated Brillouin scattering effect.

We present a novel and simple scheme for photonic generation of a millimeter-wave ultrawideband (UWB) signal free of low-frequency components that is implemented by using a stimulated Brillouin scattering (SBS)-based frequency-doubling method. A dual-parallel Mach-Zehnder modulator is incorporated to generate appropriate optical sidebands and an optical carrier carrying the UWB signal. Then the single-sideband modulation is realized based on the successive SBS frequency shifting process. Eventually, a UWB signal is upconverted to twice the frequency of the radio frequency signal. To vindicate the feasibility of the proposed scheme, an experiment is carried out, and it turns out that a UWB signal with a bandwidth of 7 GHz is upconverted to 21.75 GHz. The spectrum of the generated signal meets well with the Federal Communications Commission mask.

Increased Krüppel-like factor 12 impairs embryo attachment via downregulation of leukemia inhibitory factor in women with recurrent implantation failure.

Recurrent implantation failure (RIF) caused by various etiological factors remains a challenge for fertility clinicians using assisted reproductive technology (ART) worldwide. Dysregulation of leukemia inhibitory factor (LIF) in the endometria of women with RIF is involved in impaired endometrial receptivity and embryo adhesion. However, the mechanism through which LIF expression is regulated in women with RIF is still poorly understood. Our previous study noted that the abnormally increased endometrial Krüppel-like factor 12 (KLF12) in RIF women led to impaired decidualization and embryo implantation. Here, we further found that KLF12 inhibited embryo adhesion in vivo and in vitro by repressing LIF expression. Mechanistically, KLF12 bound to conserved sites (CAGTGGG, -6771 to -6765 and -7115 to -7109) within the LIF promoter region and repressed LIF transcription directly. Exogenous LIF significantly reversed the KLF12-mediated repression of BeWo spheroid adhesion. KLF12 expression was reduced significantly in Ishikawa cells treated with progestogen, which was due to the activation of Akt signaling. These findings may provide novel potential therapeutic regimens for patients with RIF and disrupted endometrial receptivity.

Facilitated extrinsic majority carrier depletion and photogenerated exciton dissociation in an annealing-free ZnO:C photodetector.

Applications of ZnO in photodetectors are limited by the great quantity of extrinsic majority carriers due to structural defects and difficult exciton dissociation due to the large exciton binding energy; these generally lead to a higher dark current (Id) and lower light current (Il), severely degrading the responsivity and detectivity. C dots are incorporated into an annealing-free ZnO layer to innovatively construct a local built-in electric field (Ebi) using the difference in the work functions; this simultaneously overcomes the drawbacks of the pristine ZnO photosensitive layer. In dark, the extrinsic majority carrier of ZnO is depleted around the incorporated C dots due to the self-depleting effect; thus, the Id decreases. Under UV illumination, the photogenerated exciton driven by the local Ebi is easily dissociated into a free charge carrier, contributing to the improved Il. This study paves a universal way to effectively improve the detection characteristics of photoconductive devices by incorporating the local Ebi.

Engineering the Self-Assembly Induced Emission of Cu Nanoclusters by Au(I) Doping.

Aggregation-induced emission (AIE) and self-assembly induced emission (SAIE) effects have been employed to tune the emission properties of metal nanoclusters (NCs). However, it is still not possible to further enhance the photoluminescence quantum yields (PLQYs) and control the emission colors of the NCs using AIE and SAIE. On the basis of our recent work studying the contribution of Cu(I) defects in the SAIE of Cu NCs, in this article, Au(I) was doped into Cu NC self-assembled nanosheets (NSASs) to construct a more stable Au(I)-centered state. As a result, the PLQYs, emission stability, and tunability of emission colors of the Cu NSASs were significantly improved. Detailed studies reveal that the doped Au(I) induces a Au(I)-Cu(I) metallophilic interaction, which leads to a ligand-to-Cu-Au charge transfer, which facilitates the relaxation of excited electrons via a radiative pathway, thereby enhancing the emission intensity. The charge transfer from Cu to Au lowers the energy, thus leading to the red-shift of PL emission. Au(I) is likely doped into the Cu NSASs rather than in individual NCs, because 0.3% Au doping is enough to alter the emission properties. By mixing Au(I)-doped Cu NSASs with different emission colors (due to different Au doping percentages) as color conversion materials on commercially available 365 nm GaN chips, a white light-emitting diode prototype is fabricated.