Blue Electrophosphorescence from Iridium(III) Phosphors Bearing Asymmetric Di-N-aryl 6-(trifluoromethyl)-2H-imidazo[4,5-b]pyridin-2-ylidene Chelates

Efficient blue phosphors remain a formidable challenge for organic light-emitting diodes (OLEDs). To circumvent this obstacle, a series of Ir(III)-based carbene complexes bearing asymmetric di-N-aryl 6-(trifluoromethyl)-2H-imidazo[4,5-b]pyridin-2-ylidene chelates, namely, f-ct6a‒c, are synthesized, and their structures and photophysical properties are comprehensively investigated. Moreover, these emitters can undergo interconversion in refluxing 1,2,4-trichlorobenzene, catalyzed by a mixture of sodium acetate (NaOAc) and p-toluenesulfonic acid monohydrate (TsOH·H2O) without decomposition. All Ir(III) complexes present good photoluminescence quantum yield (ΦPL = 83-88%) with peak maximum (max.) at 443-452 nm and narrowed full width at half maximum (FWHM = 66-73 nm). Among all the fabricated OLED devices, f-ct6b delivers a max. external quantum efficiency (EQE) of 23.4% and Commission Internationale de L'Eclairage CIEx , y coordinates of (0.14, 0.12), whereas the hyper-OLED device based on f-ct6a and 5H,9H,11H,15H-[1,4] benzazaborino [2,3,4-kl][1,4]benzazaborino[4',3',2':4,5][1,4]benzazaborino[3,2-b]phenazaborine-7,13-diamine, N7,N7,N13,N13,5,9,11,15-octaphenyl (ν-DABNA) exhibits max. EQE of 26.2% and CIEx , y of (0.12, 0.13). Finally, the corresponding tandem OLED with f-ct6b as dopant gives a max. luminance of over 10 000 cd m-2 and max. EQE of 42.1%, confirming their candidacies for making true-blue OLEDs.

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.

[An analysis of breast cancer patients with ultrasound BI-RADS 3 lesions after minimally invasive excision in clinicopathological features and influencing factors of residual tumor]

Objectives: To examine the clinicopathological characteristics and the influencing factors of the residual tumor of patients with Breast Image Report and Data System (BI-RADS) grade 3 lesions diagnosed with malignancy after minimally invasive excision. Methods: In this retrospective case-control study, clinicopathological data of 69 cases, which had been evaluated as BI-RADS 3 lesions by ultrasound (4 151 cases) diagnosed with breast cancer by minimally invasive excision pathology, were analyzed between May 2012 and June 2016 at the Department of Breast Surgery of the Second Hospital of Shandong University and Linyi People's Hospital. All patients were female, aged (43.4±8.2) years (range: 22 to 70 years). Based on residual tumor after minimally invasive excision, patients were classified into two subgroups: tumor residual group (n=39) and non-tumor residual group (n=30). The clinicopathological features between the two groups were compared. The differences in clinicopathological characteristics were compared in different groups using the χ2 test and the t test. Potential variables identified in the univariate analysis and other relevant variables will be analyzed multivarially using Logistic regression models. The Kaplan-Meier method was applied for survival analysis and survival curves. Results: The breast cancer detection rate of ultrasound BI-RADS 3 lesions was 1.66% (69/4 151), and their maximum diameter of the masses was (1.27±0.45) cm (range: 0.5 to 2.3 cm). Among them, the maximum diameter were ≤1 cm in 28 cases and >1 cm in 41 cases. Histopathological results showed carcinoma in situ in 24 cases and invasive carcinoma in 41 cases, positive expression of the estrogen receptor in 47 cases, positive expression of the progesterone receptor in 43 cases, Ki-67 proliferation index elevated in 26 cases. Axillary metastasis positive rate was 10.1% (7/69). Residual tumor after minimally invasive surgery was found in 39 cases (56.5%). Univariate analysis showed that the tumour residual group showed a significantly increased rate of positive expression of the estrogen receptor (91.9%(34/37) vs. 61.9%(13/21), χ2=7.838, P=0.012). In multivariate analysis, the only variable found to significantly affect the residual tumor was the positive expression of the estrogen receptor (OR=16.852, 95%CI: 1.819 to 156.130, P=0.013). The 5-year disease-free survival rate of breast cancer patients with breast ultrasound BI-RADS 3 lesions was 97.1% and the overall survival rate was 98.6%. Conclusions: BI-RADS 3 lesions diagnosed by ultrasound undergoing ultrasound-guided minimally invasive excision have a certain risk of detected malignancy, approximately 1.66%. Patients with positive expression of the estrogen receptor are more likely to develop residual tumor. A secondary operation should be considered to ensure that no tumor residues remain in the cavity.

Rosmarinic acid against cognitive impairment via RACK1/HIF-1α regulated microglial polarization in sepsis-surviving mice

Microglial polarization modulation has been considered the potential therapeutic strategy for relieving cognitive impairment in sepsis survivors. Rosmarinic acid (RA), a water-soluble polyphenolic natural compound, processes a strong protective effect on various types of neurological disorders including Parkinson's disease, depression, and anxiety. However, its role and potential molecular mechanisms in sepsis-associated cognitive impairment remain unclear. To investigate the preventive and therapeutic effect of RA on sepsis-associated cognitive impairment and elucidate the potential mechanism of RA on regulating microglial polarization, we established a CLP-induced cognitive impairment model in mice and a lipopolysaccharide-induced microglia polarization cell model in BV-2. RACK1 siRNA was designed to identify the potential molecular mechanism of RACK1 on microglial polarization. The preventive and therapeutic effect of RA on cognitive impairment followed by PET-CT and behavioral tests including open-field test and tail suspension test. RACK1/HIF-1α pathway and microglial morphology in the hippocampus or BV-2 cells were measured. The results showed that RA significantly ameliorated the CLP-induced depressive and anxiety-like behaviors and promoted whole-brain glucose uptake in mice. Moreover, RA markedly improved CLP-induced hippocampal neuron loss and microglial activation by inhibiting microglial M1 polarization. Furthermore, experiments showed RACK1 was involved in the regulation of LPS-induced microglial M1 polarization via HIF-1α, and RA suppressed lipopolysaccharide or sepsis-associated microglial M1 polarization via RACK1/HIF-1α pathway (rescued the decrease of RACK1 and increase of HIF-1α). Taken together, RA could be a potential preventive and therapeutic medication in improving cognitive impairment through RACK1/HIF-1α pathway-regulated microglial polarization.

Introducing Spiro-locks into the Nitrogen/Carbonyl System towards Efficient Narrowband Deep-blue Multi-resonance TADF Emitters

The current availability of multi-resonance thermally activated delayed fluorescence (MR-TADF) materials with excellent color purity and high device efficiency in the deep-blue region is appealing. To address this issue in the emerged nitrogen/carbonyl MR-TADF system, we propose a spiro-lock strategy. By incorporating spiro functionalization into a concise molecular skeleton, a series of emitters (SFQ, SOQ, SSQ, and SSeQ) can enhance molecular rigidity, blue-shift the emission peak, narrow the emission band, increase the photoluminescence quantum yield by over 92 %, and suppress intermolecular interactions in the film state. The referent CZQ without spiro structure has a more planar skeleton, and its bluer emission in the solution state redshifts over 40 nm with serious spectrum broadening and a low PLQY in the film state. As a result, SSQ achieves an external quantum efficiency of 25.5 % with a peak at 456 nm and a small full width at half maximum of 31 nm in a simple unsensitized device, significantly outperforming CZQ. This work discloses the importance of spiro-junction in modulating deep-blue MR-TADF emitters.

Whey protein powder with milk fat globule membrane attenuates Alzheimer's disease pathology in 3×Tg-AD mice by modulating neuroinflammation through the peroxisome proliferator-activated receptor γ signaling pathway

Whey protein powder (PP), which is mainly derived from bovine milk, is rich in milk fat globule membrane (MFGM). The MGFM has been shown to play a role in promoting neuronal development and cognition in the infant brain. However, its role in Alzheimer's disease (AD) has not been elucidated. Here, we showed that the cognitive ability of 3×Tg-AD mice (a triple-transgenic mouse model of AD) could be improved by feeding PP to mice for 3 mo. In addition, PP ameliorated amyloid peptide deposition and tau hyperphosphorylation in the brains of AD mice. We found that PP could alleviate AD pathology by inhibiting neuroinflammation through the peroxisome proliferator-activated receptor γ (PPARγ)-nuclear factor-κB signaling pathway in the brains of AD mice. Our study revealed an unexpected role of PP in regulating the neuroinflammatory pathology of AD in a mouse model.

Highly Efficient Sky-Blue π-Stacked Thermally Activated Delayed Fluorescence Emitter with Multi-Stimulus Response Properties

Organic materials with multi-stimulus response (MSR) properties have demonstrated many potential and practical applications. Herein, a π-stacked thermally activated delayed fluorescence (TADF) material with multi-stimulus response (MSR) properties, named SDMAC, was designed and synthesized using distorted 9,9-dimethyl-10-phenyl-9,10-dihydroacridine as a donor. SDMAC possesses a rigid π-stacked configuration with intramolecular through-space interactions and exhibits aggregation-induced emission enhancement (AIEE), solvatochromic, piezochromic, and circularly polarized luminescence (CPL) under different external stimuli. The rigid molecular structure and efficient TADF properties of SDMAC can be used in displays and lighting. Using SDMAC as an emitter, the maximum external quantum efficiency (EQE) of the fabricated organic light-emitting diodes (OLEDs) is as high as 28.4 %, which make them the most efficient CP-TADF OLEDs based on the through-space charge transfer strategy. The CP organic light-emitting diodes (CP-OLEDs) exhibit circularly polarized electroluminescence (CPEL) signals.

Segregated Array Tailoring Charge-Transfer Degree of Organic Cocrystal for the Efficient Near-Infrared Emission beyond 760 nm

Harvesting the narrow bandgap excitons of charge-transfer (CT) complexes for the achievement of near-infrared (NIR) emission has attracted intensive attention for its fundamental importance and practical application. Herein, the triphenylene (TP)-2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F₄ TCNQ) CT organic complex is designed and fabricated via the supramolecular self-assembly process, which demonstrates the NIR emission with a maximum peak of 770 nm and a photoluminescence quantum yield (PLQY) of 5.4%. The segregated stacking mode of TP-F₄ TCNQ CT complex based on the multiple types of intermolecular interaction has a low CT degree of 0.00103 and a small counter pitch angle of 40° between F₄ TCNQ and TP molecules, which breaks the forbidden electronic transitions of CT state, resulting in the effective NIR emission. Acting as the promising candidates for the active optical waveguide in the NIR region beyond 760 nm, the self-assembled TP-F₄ TCNQ single-crystalline organic microwires display an ultralow optical-loss coefficient of 0.060 dB µm^-1 . This work holds considerable insights for the exploration of novel NIR-emissive organic materials via an universal "cocrystal engineering" strategy.

A narrowband blue circularly polarized thermally activated delayed fluorescence emitter with a hetero-helicene structure

A narrowband blue CP-TADF emitter with a rigid hetero-helicene structure (QAO-PhCz) was synthesized and characterized. QAO-PhCz exhibits good electroluminescence performance (EQE = 14.0%) and narrow FWHM. The enantiomers of QAO-PhCz display CPL and CPEL properties with |g_lum| and |g_EL|values of up to 1.1 × 10^-3 and 1.5 × 10^-3, respectively.

[Construction of latent membrane protein 2A chimeric antigen receptor-T cells and their lethal effects on nasopharyngeal carcinoma cells]

Objective: To produce latent membrane protein 2A (LMP2A) chimeric antigen receptor (CAR)-T cells and detect the lethal effect of LMP2A CAR-T cells on nasopharyngeal carcinoma (NPC) cells. Methods: The study was conducted from September 2016 to December 2017.Genetic engineering technology was used to construct anti-LMP2A CAR lentiviral expression vector and sequencing was identified. The expression of anti-LMP2A CAR in the 293T cells was confirmed by western blot. CCK8 assay was used to evaluate the cytotoxicity of LMP2A CAR-T cells to NPC cells. ELISA assay was performed to test IL-2 and IFN-γ releasing of activated LMP2A CAR-T cells. The inhibition effect of LMP2A CAR-T cells on NPC xenograft tumor was observed in vivo. Statistical analysis was performed by statistical software SPSS 21.0. Results: The results of PCR and sequencing showed that anti-LMP2A CAR lentiviral expression vector was constructed successfully. The result of western blot indicated the expression of anti-LMP2A CAR in the 293T cells effectively. The results of CCK-8 assay showed that the killing activities of LMP2A CAR-T cells to LV-LMP2A-CNE1 cells were (72.11±9.75)%, (54.65 ±5.42)% and (36.68±3.80)% at 20∶1, 10∶1 and 5∶1 ratio of effective cells to target cells, and had a statistical difference compared to CD19 CAR-T cells and T cells (P<0.05). There was no significant difference in the killing activities of LMP2A CAR-T cells to CNE1 cells compared with CD19 CAR-T cells and T cells. The results of ELISA showed that the content of IL-2 and IFN-γ in the co-culture supernatant of LMP2A CAR-T cells and LV-LMP2A-CNE1 cells was significantly higher than that of LMP2A CAR-T cells and CNE1 cells which had statistical difference (P<0.05); In vivo experiment, the volume of LMP2A CAR-T cell group was (80.3±10.0) mm(3) which was significantly lower than that of the control groups, and the difference was statistically significant (P<0.05). Conclusion: LMP2A CAR-T cells are successfully prepared and have an obvious targeting cytotoxicity on LMP2A-positive NPC cells.

Optical Temperature Sensing Behavior Through Stark Sublevels Transitions of Green and Red Upconversion Emissions for Er3+-Yb3+-Li+ Codoped TiO2 Phosphors

The Er3+-Yb3+-Li+ codoped TiO2 phosphors have been prepared by sol-gel method. The green and red upconversion emissions were observed under a 976 nm laser diode excitation, which were ascribed to 2H11/2 --> 4I15/2, 4S3/2(I)/4S3/2(II) -->4I15/2, and 4F9/2(I)/4F9/2(II) -->4I15/2 transitions of Er3+ Stark sublevels. The fluorescence intensity ratios (FIR), which are corresponding to the transitions of 2H11/2/(4S3/2(I)+4S3/2(II))--> 4I5/2, 4S3/2(I)/4S3/2(II) -->4I15/2, and 4F9/2(II)/4F9/2(II) -->4I15/2, have been studied as a function of temperature in the range of 303 673 K. The temperature sensitivities have been calculated at the maximum value of 0.0020 K-1, 0.0015 K-1, and 0.0011 K-1 at the temperatures of 427 K, 350 K, and 273 K for the three coupled energy level transitions, respectively. The Er3+-Yb3+-Li+ codoped Ti02 phosphor with different temperature sensitivities by Stark sublevels indicated that it is a promising material for application in optical temperature sensing at a wide range of temperature.

Upconversion Luminescence Properties of Er3+ Doped Yb2Ti20 Nanophosphor by Gd3+ Codoping

Er3+ doped Yb2Ti207 nanophosphors by Gd3+ codoping with nominal composition of (Er0.05Yb0.95-xGd3+)2Ti2O7 (x = 0, 0.2, 0.4, 0.6, 0.8, and 0.95) have been prepared by sol-gel method. Er3+-Gd3+ codoped Yb2Ti2O7 was characteristic of a typical face-centered cubic crystal phase, and the unit cell parameter increased linearly with the increase of Gd3+ concentration. Under a 976 nm laser diode excitation, both green and red upconversion emissions were observed and the upconversion emissions were enhanced significantly by Gd3+ codoping, showing the strongest green and red emissions at 80 mol% Gd3+ codoping. The intensity ratio of green to red emissions (Igreen/Ired) increased monotonously with the increase of Gd3+ concentration. The energy transfer between Yb3+ and Er3+ and the variation of local crystal field symmetry of Er3+ by the substitution of Yb3+ by Gd3+ ions led to the improvement of upconversion properties of Er3+-Gd3+ codoped Yb2TiO7 nanophosphors.

Stretched inverse opal colloid crystal substrates-induced orientation of fibroblast

Recently, there has been increasing interest in studying the interaction between mammalian cells and nanometer-sized structures. However, the effect of nanostructures on cell behavior, such as cell morphology and alignment, is still largely unknown. Inverse opal colloid crystal substrates, which can be stretched to produce nano-scale pore structures of different degrees of orientation, serve as a convenient model system to study the effect of nanotopography on cell morphology and cell alignment. In this work, we fabricated inverse opal colloidal crystal films that were either unstretched or stretched to three, four or six times their original length, producing pore structures of increasing degree of orientation. Human dermal fibroblast-fetal (HDF-f) cells were seeded and cultured on these four types of substrates. The results from fluorescence microscopy and scanning electron microscopy indicated that cells showed the highest degree of alignment when cultured on inverse opal colloid crystal films that were stretched the most (six times original length). The results also demonstrated that the orientation of nanostructures could affect both the morphology and growth direction of fibroblasts. The ability to control the direction of cell growth through the engineering of nanostructures could have important applications in tissue engineering, especially for tissues with anisotropic structures, such as cardiac muscle, blood vessel, tendon and ligament.

[Effects of anti-idiotypic antibody NP30 on modulation of egg granuloma formation and hepatic fibrosis of schistosomiasis]

OBJECTIVE

To study the effects of the monoclonal anti-idiotypic antibody NP30 active immunization on egg granuloma formation and hepatic fibrosis in Schistosoma japonicum infection.

METHODS

ICR mice were actively immunized with NP30 100 micrograms x 3 i.p. every 10 days while the mice in control group were injected with SP2/0 ascites i.p. simultaneously. After cercariae challenging, the mice were killed at the 4th, 8th, 12th, 16th, 20th and 24th week, respectively. Mouse livers were removed and stained histochemically with VG and subjected to immunohistochemical assay of collagen type I, III and fibronectin(FN). The volume of egg granulomas and the content of collagen type I, III and FN were determined quantitatively by NYD-1000 Image Analysis System.

RESULTS

The volume of egg granulomas in NP30 immunized group was much smaller than that of control group from the 12th week after cercariae challenge. The cellular components of egg granulomas in NP30 immunized group were significantly different from those of the control group, exhibiting two types of atypical egg granulomas were found. VG stain revealed that the average optical density of collagen in hepatic granulomas of experimental group was lower than that of control group. Immunohistochemical assay revealed that the contents of collagen type I, III and fibronectin in egg granulomas of experimental group were lower than those of control group.

CONCLUSION

NP30 vaccination may induce both cellular and humoral protective immunity to modulate egg granulomas and suppress liver fibrosis of schistosomiasis japonica.

[Cloning and sequence analysis of the light chain variable region gene of monoclonal anti-idiotypic antibody NP30 of Schistosoma japonicum]

OBJECTIVE

To amplify and sequence the light chain of anti-idiotypic monoclonal antibody NP30 of Schistosoma japonicum.

METHODS

By comparing the conserved regions at each end of the nucleotide sequences of murine germ-line genes encoding FR1 and FR4 regions of immunoglobulin light chain variable regions, we designed a set of primers for amplification of VL gene. The hybridoma cells secreting anti-idiotypic monoclonal antibody NP30 of Schistosoma japonicum were cultured and their genome DNAs were extracted and used as templates for PCR. The PCR product was then cloned into pUC19 vector. The recombinants were sequenced by Sanger's method. The VL gene was compared with GenBank and published mouse VL genes.

RESULTS

The full-length of VL gene was 318 bp. The VL gene was a member of mouse Ig kappa light chain subgroup IV and generated from rearrangement of germ line V and J kappa 4 genes. The VL gene sequence has been registered by GenBank(accession No. AF206720).

CONCLUSION

The obtained VL gene was a potentially functional gene of anti-idiotypic monoclonal antibody NP30 of Schistosoma japonicum.