Near-Infrared Luminescent Materials Incorporating Rare Earth/Transition Metal Ions: From Materials to Applications.

The spotlight has shifted to near-infrared (NIR) luminescent materials emitting beyond 1000 nm, with growing interest due to their unique characteristics. The ability of NIR-II emission (1000-1700 nm) to penetrate deeply and transmit independently positions these NIR luminescent materials for applications in optical-communication devices, bioimaging, and photodetectors. The combination of rare earth metals/transition metals with a variety of matrix materials provides a new platform for creating new chemical and physical properties for materials science and device applications. In this review, the recent advancements in NIR emission activated by rare earth and transition metal ions are summarized and their role in applications spanning bioimaging, sensing, and optoelectronics is illustrated. It started with various synthesis techniques and explored how rare earths/transition metals can be skillfully incorporated into various matrixes, thereby endowing them with unique characteristics. The discussion to strategies of enhancing excitation absorption and emission efficiency, spotlighting innovations like dye sensitization and surface plasmon resonance effects is then extended. Subsequently, a significant focus is placed on functionalization strategies and their applications. Finally, a comprehensive analysis of the challenges and proposed strategies for rare earth/transition metal ion-doped near-infrared luminescent materials, summarizing the insights of each section is provided.

Bilateral Production Shield Enabling Highly Efficient Perovskite Photovoltaics.

Enhancing the intrinsic stability of perovskite and through encapsulation to isolate water, oxygen, and UV-induced decomposition are currently common and most effective strategies in perovskite solar cells. Here, the atomic layer deposition process is employed to deposit a nanoscale (≈100 nm), uniform, and dense Al2O3 film on the front side of perovskite devices, effectively isolating them from the erosion caused by water and oxygen in the humid air. Simultaneously, nanoscale (≈100 nm) TiO2 films are also deposited on the glass surface to efficiently filter out the ultraviolet (UV) light in the light source, which induces degradation in perovskite. Ultimately, throughthe collaborative effects of both aspects, the stability of the devices is significantly improved under conditions of humid air and illumination. As a result, after storing the devices in ambient air for 1000 h, the efficiency only declines to 95%, and even after 662 h of UV exposure, the efficiency remains at 88%, far surpassing the performance of comparison devices. These results strongly indicate that the adopted Al2O3 and TiO2 thin films play a significant role in enhancing the stability of perovskite solar cells, demonstrating substantial potential for widespread industrial applications.

Long-range order enabled stability in quantum dot light-emitting diodes.

Light-emitting diodes (LEDs) based on perovskite quantum dots (QDs) have produced external quantum efficiencies (EQEs) of more than 25% with narrowband emission1,2, but these LEDs have limited operating lifetimes. We posit that poor long-range ordering in perovskite QD films-variations in dot size, surface ligand density and dot-to-dot stacking-inhibits carrier injection, resulting in inferior operating stability because of the large bias required to produce emission in these LEDs. Here we report a chemical treatment to improve the long-range order of perovskite QD films: the diffraction intensity from the repeating QD units increases three-fold compared with that of controls. We achieve this using a synergistic dual-ligand approach: an iodide-rich agent (aniline hydroiodide) for anion exchange and a chemically reactive agent (bromotrimethylsilane) that produces a strong acid that in situ dissolves smaller QDs to regulate size and more effectively removes less conductive ligands to enable compact, uniform and defect-free films. These films exhibit high conductivity (4 × 10-4 S m-1), which is 2.5-fold higher than that of the control, and represents the highest conductivity recorded so far among perovskite QDs. The high conductivity ensures efficient charge transportation, enabling red perovskite QD-LEDs that generate a luminance of 1,000 cd m-2 at a record-low voltage of 2.8 V. The EQE at this luminance is more than 20%. Furthermore, the stability of the operating device is 100 times better than previous red perovskite LEDs at EQEs of more than 20%.

Customizable Organic Charge-Transfer Cocrystals for the Dual-Mode Optoelectronics in the NIR (II) Window.

Organic molecules have been regarded as ideal candidates for near-infrared (NIR) optoelectronic active materials due to their customizability and ease of large-scale production. However, constrained by the intricate molecular design and severe energy gap law, the realization of optoelectronic devices in the second near-infrared (NIR (II)) region with required narrow band gaps presents more challenges. Herein, we have originally proposed a cocrystal strategy that utilizes intermolecular charge-transfer interaction to drive the redshift of absorption and emission spectra of a series BFXTQ (X = 0, 1, 2, 4) cocrystals, resulting in the spectra located at NIR (II) window and reducing the optical bandgap to ∼0.98 eV. Significantly, these BFXTQ-based optoelectronic devices can exhibit dual-mode optoelectronic characteristics. An investigation of a series of BFXTQ-based photodetectors exhibits detectivity (D*) surpassing 1013 Jones at 375 to 1064 nm with a maximum of 1.76 × 1014 Jones at 1064 nm. Moreover, the radiative transition of CT excitons within the cocrystals triggers NIR emission over 1000 nm with a photoluminescence quantum yield (PLQY) of ∼4.6% as well as optical waveguide behavior with a low optical-loss coefficient of 0.0097 dB/µm at 950 nm. These results promote the advancement of an emerging cocrystal approach in micro/nanoscale NIR multifunctional optoelectronics.

Virtual draw of microstructured optical fiber based on physics-informed neural networks.

The implementation of microstructured optical fibers (MOFs) with novel micro-structures and perfect performance is challenging due to the complex fabrication processes. Physics-informed neural networks (PINNs) offer what we believe to be a new approach to solving complex partial differential equations within the virtual fabrication model of MOFs. This study, for what appears to be the first time, integrates the complex partial differential equations and boundary conditions describing the fiber drawing process into the loss function of a neural network. To more accurately solve the free boundary of the fiber's inner and outer diameters, we additionally construct a neural network to describe the free boundary conditions. This model not only captures the evolution of the fiber's inner and outer diameters but also provides the velocity distribution and pressure distribution within the molten glass, thus laying the foundation for a quantitative analysis of capillary collapse. Furthermore, results indicate that the trends in the effects of temperature, feed speed, and draw speed on the fiber drawing process align with actual fabrication conditions, validating the feasibility of the model. The methodology proposed in this study offers what we believe to be a novel approach to simulating the fiber drawing process and holds promise for advancing the practical applications of MOFs.

Next-generation sequencing reveals genetic heterogeneity and resistance mechanisms in patients with EGFR-mutated non-small cell lung cancer treated with afatinib.

Background: Afatinib, an irreversible ErbB family inhibitor, is widely used as first-line treatment in advanced lung adenocarcinoma patients harbouring mutant epidermal growth factor receptor (EGFR). With the advancements in next-generation sequencing (NGS), comprehensive research into the clinical impact of co-occurring genetic mutations and the molecular mechanisms of acquired resistance is required for afatinib users. Materials: From January 2010 to December 2019, we enrolled patients with advanced lung adenocarcinoma with EGFR mutations using afatinib as first-line treatment, and we retrospectively collected pre- and post-afatinib treatment specimens from these patients for NGS testing. Results: Of the 362 enrolled patients, 73 samples (68.9%) from 56 patients successfully returned complete NGS reports. In pre-afatinib treatment specimens, the most frequent co-occurring alterations were TP53, MUC16, USH2A, SNYE1, RECQL4 and FAT1; however, they were not related to progression-free survival. Small cell lung cancer transformation, EGFR p.T790M, amplification of MET, ERBB2, KRAS, EGFR, cell cycle-regulated genes and MDM2, and PTEN alterations were identified as acquired resistance mechanisms. EGFR p.T790M (p=0.0304) and APC alterations (p=0.0311) in post-afatinib specimens were significantly associated with longer overall survival, while MET amplification was significantly associated with poor overall survival (p=0.0324). The co-occurrence of TP53 alterations was significantly associated with shorter overall survival (p=0.0298). Conclusions: Our results show that the frequent co-occurring alterations in advanced EGFR-mutated lung adenocarcinoma did not influence the effectiveness of afatinib. EGFR p.T790M is not only the major resistance mechanism to afatinib but also related to favourable survival outcomes. MET amplification and TP53 mutations were associated with poorer overall survival.

Enhancing Light Outcoupling Efficiency via Anisotropic Low Refractive Index Electron Transporting Materials for Efficient Perovskite Light-Emitting Diodes.

Thanks to the extensive efforts toward optimizing perovskite crystallization properties, high-quality perovskite films with near-unity photoluminescence quantum yield are successfully achieved. However, the light outcoupling efficiency of perovskite light-emitting diodes (PeLEDs) is impeded by insufficient light extraction, which poses a challenge to the further advancement of PeLEDs. Here, an anisotropic multifunctional electron transporting material, 9,10-bis(4-(2-phenyl-1H-benzo[d]imidazole-1-yl)phenyl) anthracene (BPBiPA), with a low extraordinary refractive index (ne ) and high electron mobility is developed for fabricating high-efficiency PeLEDs. The anisotropic molecular orientations of BPBiPA can result in a low ne of 1.59 along the z-axis direction. Optical simulations show that the low ne of BPBiPA can effectively mitigate the surface plasmon polariton loss and enhance the photon extraction efficiency in waveguide mode, thereby improving the light outcoupling efficiency of PeLEDs. In addition, the high electron mobility of BPBiPA can facilitate balanced carrier injection in PeLEDs. As a result, high-efficiency green PeLEDs with a record external quantum efficiency of 32.1% and a current efficiency of 111.7 cd A-1 are obtained, which provides new inspirations for the design of electron transporting materials for high-performance PeLEDs.

Visualizing the interfacial-layer-based epitaxial growth process toward organic core-shell architectures.

Organic heterostructures (OHTs) with the desired geometry organization on micro/nanoscale have undergone rapid progress in nanoscience and nanotechnology. However, it is a significant challenge to elucidate the epitaxial-growth process for various OHTs composed of organic units with a lattice mismatching ratio of > 3%, which is unimaginable for inorganic heterostructures. Herein, we have demonstrated a vivid visualization of the morphology evolution of epitaxial-growth based on a doped interfacial-layer, which facilitates the comprehensive understanding of the hierarchical self-assembly of core-shell OHT with precise spatial configuration. Significantly, the barcoded OHT with periodic shells obviously illustrate the shell epitaxial-growth from tips to center parts along the seeded rods for forming the core-shell OHT. Furthermore, the diameter, length, and number of periodic shells were modulated by finely tuning the stoichiometric ratio, crystalline time, and temperature, respectively. This epitaxial-growth process could be generalized to organic systems with facile chemical/structural compatibility for forming the desired OHTs.

[Screening of bioactive components endowing hawthorn with turbidity-eliminating and lipid-lowering functions and development of quality control method of hawthorn].

Hawthorn has the efficacy of eliminating turbidity and lowering the blood lipid level, and it is used for treating hyperlipidemia in clinic. However, the bioactive components of hawthorn are still unclear. In this study, the spectrum-effect relationship was employed to screen the bioactive components of hawthorn in the treatment of hyperlipidemia, and then the bioactive components screened out were verified in vivo. Furthermore, the quality control method for hawthorn was developed based on liquid chromatography-mass spectrometry(LC-MS). The hyperlipidemia model of rats was built, and different polar fractions of hawthorn extracts and their combinations were administrated by gavage. The effects of different hawthorn extract fractions on the total cholesterol(TC), triglycerides(TG), and low-density lipoprotein-cholesterol(LDL-C) in the serum of model rats were studied. The orthogonal projections to latent structures(OPLS) algorithm was used to establish the spectrum-effect relationship model between the 24 chemical components of hawthorn and the pharmacodynamic indexes, and the bioactive components were screened out and verified in vivo. Finally, 10 chemical components of hawthorn, including citric acid and quinic acid, were selected to establish the method for evaluating hawthorn quality based on LC-MS. The results showed that different polar fractions of hawthorn extracts and their combinations regulated the TG, TC, and LDL-C levels in the serum of the model rats. The bioactive components of hawthorn screened by the OPLS model were vitexin-4″-O-glucoside, vitexin-2″-O-rhamnoside, rutin, citric acid, malic acid, and quinic acid. The 10 chemical components of hawthorn, i.e., citric acid, quinic acid, rutin, gallic acid, vitexin-4″-O-glucoside, vitexin-2″-O-rhamnoside, malic acid, vanillic acid, neochlorogenic acid, and fumaric acid were determined, with the average content of 38, 11, 0.018, 0.009 5, 0.037, 0.017, 8.1, 0.009 5, 0.073, and 0.98 mg·g~(-1), respectively. This study provided a scientific basis for elucidating the material basis of hawthorn in treating hyperlipidemia and developed a content determination method for evaluating the quality of hawthorn.

Polarity-Mediated Antisolvent Control Enables Efficient Lanthanide-Based near-Infrared Perovskite LEDs.

Alloying lanthanide ions (Yb3+) into perovskite quantum dots (Yb3+:CsPb(Cl1-xBrx)3) is an effective method to achieve efficient near-infrared (NIR) luminescence (>950 nm). Increasing the Yb3+ alloying ratio in the perovskite matrix enhances the luminescence intensity of Yb3+ emission at 990 nm. However, high Yb3+ alloying (>15%) results in vacancy-induced inferior material stability. In this work, we developed a polarity-mediated antisolvent manipulation strategy to resolve the incompatibility between a high Yb3+ alloying ratio and inferior stability of Yb3+:CsPb(Cl1-xBrx)3. Precise control of solution polarity enables increased uniformity of the perovskite matrix with fewer trap densities. Employing this strategy, we obtain Yb3+:CsPb(Cl1-xBrx)3 with the highest Yb3+ alloying ratio of 30.2% and a 2-fold higher electroluminescence intensity at 990 nm. We lever the engineered Yb3+:CsPb(Cl1-xBrx)3 to fabricate NIR-LEDs, achieving a peak external quantum efficiency (EQE) of 8.5% at 990 nm: this represents the highest among perovskite NIR-LEDs with an emission wavelength above 950 nm.

In Situ Hydrolysis of Phosphate Enabling Sky-Blue Perovskite Light-Emitting Diode with EQE Approaching 16.32.

The performance of blue perovskite light-emitting diodes (PeLEDs) lags behind the green and red counterparts owing to high trap density and undesirable red shift of the electroluminescence spectrum under operation conditions. Organic molecular additives were employed as passivators in previous reports. However, most commonly have limited functions, making it challenging to effectively address both efficiency and stability issues simultaneously. Herein, we reported an innovatively dynamic in situ hydrolysis strategy to modulate quasi-2D sky-blue perovskites by the multifunctional passivator phenyl dichlorophosphate that not only passivated the defects but also underwent in situ hydrolysis reaction to stabilize the emission. Moreover, hydrolysis products were beneficial for low-dimensional phase manipulation. Eventually, we obtained high-performance sky-blue PeLEDs with a maximum external quantum efficiency (EQE) of 16.32% and an exceptional luminance of 5740 cd m-2. More importantly, the emission peak of devices located at 485 nm remained stable under different biases. Our work signified the significant advancement toward realizing future applications of PeLEDs.

Reliability and Variability of Ki-67 Digital Image Analysis Methods for Clinical Diagnostics in Breast Cancer.

Ki-67 is a nuclear protein associated with proliferation, and a strong potential biomarker in breast cancer, but is not routinely measured in current clinical management owing to a lack of standardization. Digital image analysis (DIA) is a promising technology that could allow high-throughput analysis and standardization. There is a dearth of data on the clinical reliability as well as intra- and interalgorithmic variability of different DIA methods. In this study, we scored and compared a set of breast cancer cases in which manually counted Ki-67 has already been demonstrated to have prognostic value (n = 278) to 5 DIA methods, namely Aperio ePathology (Lieca Biosystems), Definiens Tissue Studio (Definiens AG), Qupath, an unsupervised immunohistochemical color histogram algorithm, and a deep-learning pipeline piNET. The piNET system achieved high agreement (interclass correlation coefficient: 0.850) and correlation (R = 0.85) with the reference score. The Qupath algorithm exhibited a high degree of reproducibility among all rater instances (interclass correlation coefficient: 0.889). Although piNET performed well against absolute manual counts, none of the tested DIA methods classified common Ki-67 cutoffs with high agreement or reached the clinically relevant Cohen's κ of at least 0.8. The highest agreement achieved was a Cohen's κ statistic of 0.73 for cutoffs 20% and 25% by the piNET system. The main contributors to interalgorithmic variation and poor cutoff characterization included heterogeneous tumor biology, varying algorithm implementation, and setting assignments. It appears that image segmentation is the primary explanation for semiautomated intra-algorithmic variation, which involves significant manual intervention to correct. Automated pipelines, such as piNET, may be crucial in developing robust and reproducible unbiased DIA approaches to accurately quantify Ki-67 for clinical diagnosis in the future.

Effects of Deuterium Isotopes on Pt(II) Complexes and Their Impact on Organic NIR Emitters.

Insight into effect of deuterium isotopes on organic near-IR (NIR) emitters was explored by the use of self-assembled Pt(II) complexes H-3-f and HPh-3-f, and their deuterated analogues D-3-f and DPh-3-f, respectively (Scheme 2). In vacuum deposited thin film, albeit having nearly identical emission spectral feature maximized at ~810 nm, H-3-f and D-3-f exhibit remarkable difference in photoluminescence quantum yield (PLQY) of 29 % and 50 %, respectively. Distinction in PLQY is also observed for HPh-3-f (800 nm, 50 %) and DPh-3-f (798 nm, 67 %). We then elucidated the theoretical differences in the impact on near-infrared (NIR) luminescence between Pt(II) complexes and organic small molecules upon deuteration. The results establish a general guideline for the deuteration on NIR emission efficiency. From a perspective of practical application, NIR OLEDs based on D-3-f and DPh-3-f emitters attain EQEmax of 15.5 % (radiance 31,287 mW Sr-1 m-2 ) and 16.6 % (radiance of 32,279 mW Sr-1 m-2 ) at 764 nm and 796 nm, respectively, both of which set new records for NIR OLEDs of >750 nm.

Magnetic-biased chiral molecules enabling highly oriented photovoltaic perovskites.

The interaction between sites A, B and X with passivation molecules is restricted when the conventional passivation strategy is applied in perovskite (ABX3) photovoltaics. Fortunately, the revolving A-site presents an opportunity to strengthen this interaction by utilizing an external field. Herein, we propose a novel approach to achieving an ordered magnetic dipole moment, which is regulated by a magnetic field via the coupling effect between the chiral passivation molecule and the A-site (formamidine ion) in perovskites. This strategy can increase the molecular interaction energy by approximately four times and ensure a well-ordered molecular arrangement. The quality of the deposited perovskite film is significantly optimized with inhibited nonradiative recombination. It manages to reduce the open-circuit voltage loss of photovoltaic devices to 360 mV and increase the power conversion efficiency to 25.22%. This finding provides a new insight into the exploration of A-sites in perovskites and offers a novel route to improving the device performance of perovskite photovoltaics.

The middle-aged and older Chinese adults' health using actigraphy in Taiwan (MOCHA-T): protocol for a multidimensional dataset of health and lifestyle.

BACKGROUND AND OBJECTIVES: Older adults keep transforming with Baby Boomers and Gen Xers being the leading older population. Their lifestyle, however, is not well understood. The middle-aged and older Chinese adults' health using actigraphy in Taiwan (MOCHA-T) collected both objective and subjective data to depict the health and lifestyle of this population. The objectives, design, and measures of the MOCHA-T study are introduced, and the caveats and future directions related to the use of the data are presented. METHODS: People aged 50 and over were recruited from the community, with a subset of women aged 45-49 invited to supplement data on menopause and aging. Four instruments (i.e., self-reported questionnaires, diary, wrist actigraphy recorder, and GPS) were used to collect measures of sociodemographic, health, psychosocial, behavioral, temporal, and spatial data. RESULTS: A total of 242 participants who returned the informed consent and questionnaires were recruited in the MOCHA-T study. Among them, 94.6%, 95.0%, and 25.2% also completed the diary, actigraphy, and GPS data, respectively. There was almost no difference in sociodemographic characteristics between those with and without a completed diary, actigraphy, and GPS data, except for age group and educational level for those who returned completed actigraphy data. CONCLUSION: The MOCHA-T study is a multidimensional dataset that allows researchers to describe the health, behaviors, and lifestyle patterns, and their interactions with the environment of the newer generation of middle-aged and older adults in Taiwan. It can be compared with other countries with actigraphy and GPS-based lifestyle data of middle-aged and older adults in the future.

[Effects of Foliar Application of Silicon Fertilizers on Phyllosphere Bacterial Community and Functional Genes of Paddy Irrigated with Reclaimed Water].

Agricultural utilization of reclaimed water is considered to be an effective way to solve water shortage and reduce water environmental pollution. Silicon fertilizer can improve crop yield and quality and enhance crop resistance. The effect of foliar spray with silicon fertilizer on phyllosphere microbial communities remains lacking. In this study, a pot experiment was conducted to explore the effects of different types of silicon fertilizer on the composition and diversity of a phyllosphere bacterial community and the abundances of related functional genes in rice irrigated with reclaimed water. The results showed that Firmicutes, Proteobacteria, Actinobacteriota, Bacteroidota, and Verrucomicrobiota dominated the phyllosphere bacteria of rice. The relative abundance of Bacillus was higher than that of other treatments in RIS3. Reclaimed water irrigation significantly increased the relative abundances of the potential pathogens Pantoea and Enterobacter. The unclassified bacteria were also an important part of the bacterial community in the rice phyllosphere. Bacillus, Exiguobacterium, Aeromonas, and Citrobacter were significantly enriched by silicon fertilizer treatments. Functional prediction analysis showed that indicator species were mainly involved in metabolism and degradation functions, and the predicted functional groups of phyllosphere bacteria were attributed to chemoheterotrophy, aerobic chemoheterotrophy, nitrate reduction, and fermentation. Quantitative PCR results showed that AOA, AOB, and nifH genes were at low abundance levels in all treatments, and nirK genes was not significantly different among treatments. These results contribute to the in-depth understanding of the effects of foliar spray silicon fertilizer on the bacterial community structure and diversity of rice phyllosphere and provide a theoretical basis for the application of silicon fertilizer in reclaimed water irrigation agriculture.

Hypoxia-induced ZEB1 promotes cervical cancer immune evasion by strengthening the CD47-SIRPα axis.

BACKGROUND: The dynamic interaction between cancer cells and tumour-associated macrophages (TAMs) in the hypoxic tumour microenvironment (TME) is an active barrier to the effector arm of the antitumour immune response. Cancer-secreted exosomes are emerging mediators of this cancer-stromal cross-talk in the TME; however, the mechanisms underlying this interaction remain unclear. METHODS: Exosomes were isolated with ExoQuick exosome precipitation solution. The polarizing effect of TAMs was evaluated by flow cytometry, western blot analysis, immunofluorescence staining and in vitro phagocytosis assays. Clinical cervical cancer specimens and an in vivo xenograft model were also employed. RESULTS: Our previous study showed that hypoxia increased the expression of ZEB1 in cervical squamous cell carcinoma (CSCC) cells, which resulted in increased infiltration of TAMs. Here, we found that hypoxia-induced ZEB1 expression is closely correlated with CD47-SIRPα axis activity in CSCC, which enables cancer cells to evade phagocytosis by macrophages and promotes tumour progression. ZEB1 was found to directly activate the transcription of the CD47 gene in hypoxic CSCC cells. We further showed that endogenous ZEB1 was characteristically enriched in hypoxic CSCC cell-derived exosomes and transferred into macrophages via these exosomes to promote SIRPα+ TAM polarization. Intriguingly, exosomal ZEB1 retained transcriptional activity and reprogrammed SIRPα+ TAMs via activation of the STAT3 signalling pathway in vitro and in vivo. STAT3 inhibition reduced the polarizing effect induced by exosomal ZEB1. Knockdown of ZEB1 increased the phagocytosis of CSCC cells by macrophages via decreasing CD47 and SIRPα expression. CONCLUSIONS: Our results suggest that hypoxia-induced ZEB1 promotes immune evasion in CSCC by strengthening the CD47-SIRPα axis. ZEB1-targeted therapy in combination with CD47-SIRPα checkpoint immunotherapy may improve the outcomes of CSCC patients in part by disinhibiting innate immunity.

Bis-tridentate Ir(III) Phosphors and Blue Hyperphosphorescence with Suppressed Efficiency Roll-Off at High Brightness.

Narrowband blue emitters are indispensable in achieving ultrahigh-definition OLED displays that satisfy the stringent BT 2020 standard. Hereby, a series of bis-tridentate Ir(III) complexes bearing electron-deficient imidazo[4,5-b]pyridin-2-ylidene carbene coordination fragments and 2,6-diaryloxy pyridine ancillary groups were designed and synthesized. They exhibited deep blue emission with quantum yields of up to 89% and a radiative lifetime of 0.71 µs in the DPEPO host matrix, indicating both the high efficiency and excellent energy transfer process from the host to dopant. The OLED based on Irtb1 showed an emission at 468 nm with a maximum external quantum efficiency (EQE) of 22.7%. Moreover, the hyper-OLED with Irtb1 as a sensitizer for transferring energy to terminal emitter v-DABNA exhibited a narrowband blue emission at 472 nm and full width at half-maximum (FWHM) of 24 nm, a maximum EQE of 23.5%, and EQEs of 19.7, 16.1, and 12.9% at a practical brightness of 100, 1000, and 5000 cd/m2, respectively.

High-throughput virtual screening of organic second-order nonlinear optical chromophores within the donor-π-bridge-acceptor framework.

In view of the theoretical importance and huge application potential of second-order nonlinear optical (NLO) materials, it is of great significance to conduct high-throughput virtual screening (HTVS) on a compound library to find candidate NLO chromophores. Under the donor-π-bridge-acceptor structural framework, a virtual compound library (size = 27 090) was constructed by enumeration of structural fragments. The kernel property adopted for optimization is the static first hyperpolarizability (ß0). By combining machine learning and quantum chemical calculations, we have performed an HTVS procedure to sieve NLO chromophores out, and the response mechanism of the selected optimal NLO chromophores was examined. We have found: (a) The multi-layer perceptron/extended connectivity fingerprint combination with 20% selection ratio gives the highest prediction accuracy for the studied systems. (b) The two optimal donors are bis(4-diphenylaminophenyl)aminyl and bis(4-tert-butylphenyl)aminyl; the optimal π-bridges are composed of two thiophenyl, selenophenyl or furanyl units; and the two optimal acceptors are tri-s-triazinyl and 2,3-dicyanopyrazinyl. (c) The no. 1 candidate molecule can exhibit a calculated ß0 equal to 8.55 × 104 a.u. (d) The difference in NLO responses of the optimal 16 molecules comes from the synergistic interaction of ES1, Δµ and f, by employing the two-level model. In addition, the sizable Δµ and f allow the studied optimal molecules to obtain a large NLO response in the meantime keeping a not-too-low excitation energy (retaining good optical transparency in the restricted range of the visible spectrum region). (e) With further modification on the acceptor, the designed DPA-π-TRZ-A' (A' = CN or NO2, π = oligo-thiophenyl or selenophenyl) systems can exhibit a rather large NLO response (maximum ß0 = 3.17 × 105 a.u.), hence should have considerable potential as second-order NLO chromophores. With the above observations, we expect to provide some insight for the research community into the HTVS of organic second-order NLO chromophores.

Factors influencing turnover intention among male nurses in China: A large-scale descriptive correlational study.

AIM: This study examined the correlation among turnover intention, emotional intelligence and job burnout in male nurses and determined its influencing factors. BACKGROUND: The number of male nurses has increased in China; however, the turnover rate is very high. Nurses' turnover intention is related to job burnout and emotional intelligence. INTRODUCTION: Recent studies have shown that job burnout and emotional intelligence are related to medical and health institution employees' intention to leave their jobs. It is not clear if the same conclusions can be drawn about male nurses. METHODS: For this cross-sectional study, 627 male nurses were recruited from across China between May and July 2018. Data were collected through an online questionnaire, and Pearson's product-moment correlation coefficient and multiple linear regression were performed to analyse the data. RESULTS: There was a weak negative, moderate positive and moderate negative correlation between turnover intention and emotional intelligence, turnover intention and job burnout, and emotional intelligence and job burnout, respectively. Factors that significantly affected turnover intention among male nurses included job burnout, young age, lack of interest in nursing and working in the emergency department. CONCLUSION: The study revealed the factors that affected male nurses' turnover intention and the relationships between turnover intention, emotional intelligence and job burnout. IMPLICATIONS FOR NURSING MANAGEMENT AND SOCIAL POLICY: Hospital managers should provide necessary help and support to reduce male nurse turnover rates and incorporate emotional intelligence training. The policy should eliminate the unfair college admission practices for students choosing nursing majors, raise the nursing profession's salaries and vigorously develop specialty nursing. In addition, diversified values should be promoted, and stereotypes of male nurses in nursing should be broken.