Highly Luminescent Earth-Benign Organometallic Manganese Halide Crystals with Ultrahigh Thermal Stability of Emission from 4 to 623 K.

The phosphor-converted light-emitting diode (PC-LED) has become an indispensable solid-state lighting and display technologies in the modern society. Nevertheless, the use of scarce rare-earth elements and the thermal quenching (TQ) behavior are still two most crucial issues yet to be solved. Here, this work successfully demonstrates a highly efficient and thermally stable green emissive MnI2 (XanPO) crystals showing a notable photoluminescence quantum yield (PLQY) of 94% and a super TQ resistance from 4 to 623 K. This unprecedented superior thermal stability is attributed to the low electron-phonon coupling and the unique rigid crystal structure of MnI2 (XanPO) over the whole temperature range based on the temperature-dependent photoluminescence (PL) and single crystal X-ray diffraction (SCXRD) analyses. Considering these appealing properties, green PC-LEDs with a power efficacy of 102.5 lm W-1 , an external quantum efficiency (EQE) of 22.7% and a peak luminance up to 7750 000 cd m-2 are fabricated by integrating MnI2 (XanPO) with commercial blue LEDs. Moreover, the applicability of MnI2 (XanPO) in both micro-LEDs and organic light-emitting diodes (OLEDs) is also demonstrated. In a nutshell, this study uncovers a candidate of highly luminescent and TQ resistant manganese halide suitable for a variety of emission applications.

Solution-Processed Chloroaluminum Phthalocyanine (ClAlPc) Ammonia Gas Sensor with Vertical Organic Porous Diodes.

In this research work, the gas sensing properties of halogenated chloroaluminum phthalocyanine (ClAlPc) thin films were studied at room temperature. We fabricated an air-stable ClAlPc gas sensor based on a vertical organic diode (VOD) with a porous top electrode by the solution process method. The surface morphology of the solution-processed ClAlPc thin film was examined by field emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM). The proposed ClAlPc-based VOD sensor can detect ammonia (NH3) gas at the ppb level (100~1000 ppb) at room temperature. Additionally, the ClAlPc sensor was highly selective towards NH3 gas compared to other interfering gases (NO2, ACE, NO, H2S, and CO). In addition, the device lifetime was tested by storing the device at ambient conditions. The effect of relative humidity (RH) on the ClAlPc NH3 gas sensor was also explored. The aim of this study is to extend these findings on halogenated phthalocyanine-based materials to practical electronic nose applications in the future.

Chromaticity tailorable glass-based phosphor-converted white light-emitting diodes with high color rendering index.

In this paper, Lu3Al5O12:Ce3+ and CaAlSiN3: Eu2+ co-doped glass are presented as color conversion materials for white light-emitting diodes (WLEDs). Through adjusting the thickness of the glass phosphors, the chromaticity and CCT of the WLEDs follows the Planckian locus well. The WLEDs show CCT ranging from ~4000K to ~7000K with high CRI ranging from 83 to 90 due to the wide emission spectrum from the proposed glass phosphors. The glass phosphors provide an effective way to achieve chromaticity-tailorable WLEDs with high color quality for indoor lighting applications.

Novel broadband glass phosphors for high CRI WLEDs.

New broadband glass phosphors with excellent thermal stability were proposed and experimentally demonstrated for white light-emitting-diodes (WLEDs). The novel glass phosphors were realized through dispersing multiple phosphors into SiO2 based glass (SiO2-Na2O-Al2O3-CaO) at 680°C. Y3Al5O12:Ce³âº (YAG), Lu3Al5O12:Ce³âº (LuAG), and CaAlSiN3: Eu²âº (nitride) phosphor crystals were chosen respectively as the yellow, green, and red emitters of the glass phosphors. The effect of sintering temperature on inter-diffusion reduction between phosphor crystals and amorphous SiO2 in nitride-doped glass phosphors was studied and evidenced by the aid of high-resolution transmission electron microscopy (HRTEM). Broadband glass phosphors with high quantum-yield of 55.6% were thus successfully realized through the implementation of low sintering temperature. Proof-of-concept devices utilizing the novel broadband phosphors were developed to generate high-quality cool-white light with trisstimulus coordinates (x, y) = (0.358, 0.288), color-rending index (CRI) = 85, and correlated color temperature (CCT) = 3923K. The novel broadband glass phosphors with excellent thermal stability are essentially beneficial to the applications for next-generation solid-state indoor lighting, especially in the area where high power and absolute reliability are required.

High bandwidth semipolar (20-21) micro-LED-based white light-emitting diodes utilizing perovskite quantum dots and organic emitters in color-conversion layers for visible light communication and solid-state lighting applications.

We demonstrate semipolar (20-21) micro-LED-based high-bandwidth WLEDs utilizing perovskite QDs and organic emitters in color-conversion films. The WLEDs exhibit a bandwidth in excess of 1 GHz and a CCT of 6141 K, making these devices suitable for visible light communication and lighting applications.

Vacuum-Deposited Inorganic Perovskite Light-Emitting Diodes with External Quantum Efficiency Exceeding 10% via Composition and Crystallinity Manipulation of Emission Layer under High Vacuum.

Although vacuum-deposited metal halide perovskite light-emitting diodes (PeLEDs) have great promise for use in large-area high-color-gamut displays, the efficiency of vacuum-sublimed PeLEDs currently lags that of solution-processed counterparts. In this study, highly efficient vacuum-deposited PeLEDs are prepared through a process of optimizing the stoichiometric ratio of the sublimed precursors under high vacuum and incorporating ultrathin under- and upper-layers for the perovskite emission layer (EML). In contrast to the situation in most vacuum-deposited organic light-emitting devices, the properties of these perovskite EMLs are highly influenced by the presence and nature of the upper- and presublimed materials, thereby allowing us to enhance the performance of the resulting devices. By eliminating Pb° formation and passivating defects in the perovskite EMLs, the PeLEDs achieve an outstanding external quantum efficiency (EQE) of 10.9% when applying a very smooth and flat geometry; it reaches an extraordinarily high value of 21.1% when integrating a light out-coupling structure, breaking through the 10% EQE milestone of vacuum-deposited PeLEDs.

Structural elucidation and bioactivity of biflavonoids from the stems of Wikstroemia taiwanensis.

Three new biflavonoids, wikstaiwanones A-C (1-3), along with four known compounds (4-7) were isolated from the stems of Wikstroemia taiwanensis (Thymelaeaceae). Their structures were elucidated by spectroscopic analysis. Compounds 4 and 5 showed antitubercular activity against Mycobacterium tuberculosis with MIC values of 15 µg/mL, respectively.

Recent Advances in Colloidal Quantum Dots or Perovskite Quantum Dots as a Luminescent Downshifting Layer Embedded on Solar Cells.

The solar cell has a poor spectral response in the UV region, which affects its power conversion efficiency (PCE). The utilization of a luminescent downshifting (LDS) layer has been suggested to improve the spectral response of the photovoltaics in the short wavelength region through photoluminescence (PL) conversion and antireflection effects, which then enhance the PCE of the solar cell. Recently, colloidal quantum dots (CQDs) or perovskite quantum dots (PQDs) have been gaining prime importance as an LDS material due to their eminent optical characteristics, such as their wide absorption band, adjustable visible emission, short PL lifetime, and near-unity quantum yields. However, the instability of QDs that occurs under certain air, heat, and moisture conditions limits its commercialization. Thus, in this review, we will focus on the physical and optical characteristics of QDs. Further, we will discuss different synthesis approaches and the stability issues of QDs. Different approaches to improve the stability of QDs will be discussed in detail alongside the recent breakthroughs in QD-based solar cells for various applications and their current challenges. We expect that this review will provide an effective gateway for researchers to fabricate LDS-layer-based solar cells.

Rapid quality test for drinking water by vertical-channel organic semiconductor gas sensor.

In this work, we proposed a rapid and easy check of the drinking water pollution level due to bacteria growth by semiconductor gas sensor. Highly sensitive vertical channel organic ammonia gas sensor was used to detect the gases emitted from the polluted water, and then determined effective ammonia concentration according to its response. Residues from meat of fish, shrimp, and fruits were mashed and added to the clean water. The water samples were stored at 35 °C for natural decay. Initially the bacteria concentration was below 100 colony forming unit per ml (cfu/ml), then it increased to103 cfu/ml in 2 h and 105 cfu/ml in 4 h, which was beyond the drinking safety standard, 500 cfu/ml. At this gas level no bad odor can be sensed by human yet, however, the effective ammonia concentration of those samples rises to 300-500 ppb in 2 h. The amine gas sensor can therefore be used as a rapid check if the bacteria level inside the water is far over the safety standard.

Integration of on-chip perovskite nanocrystal laser and long-range surface plasmon polariton waveguide with etching-free process.

Perovskite materials prepared in the form of solution-processed nanocrystals and used in top-down fabrication techniques are very attractive to develop low-cost and high-quality integrated optoelectronic circuits. Particularly, integrated miniaturized coherent light sources that can be connected to light-guiding structures on a chip are highly desired. To control light propagating on a small footprint with low-loss optical modes, long-range surface plasmon polariton (LRSPP) waveguides are employed. Herein, we demonstrate an on-chip fabricated photonic-plasmonic hybrid system consisting of a perovskite lasing structure coupled to an LRSPP waveguide achieving a low lasing threshold and a propagation length over 100 µm. Preventing perovskite material degradation and the formation of surface roughness of the laser cavity during fabrication is made possible by designing a fabrication technique without any etching step.

Antigenic Cross-Reactivity Between SARS-CoV-2 S1-RBD and Its Receptor ACE2.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is an emerging virus responsible for the ongoing COVID-19 pandemic. SARS-CoV-2 binds to the human cell receptor angiotensin-converting enzyme 2 (ACE2) through its receptor-binding domain in the S1 subunit of the spike protein (S1-RBD). The serum levels of autoantibodies against ACE2 are significantly higher in patients with COVID-19 than in controls and are associated with disease severity. However, the mechanisms through which these anti-ACE2 antibodies are induced during SARS-CoV-2 infection are unclear. In this study, we confirmed the increase in antibodies against ACE2 in patients with COVID-19 and found a positive correlation between the amounts of antibodies against ACE2 and S1-RBD. Moreover, antibody binding to ACE2 was significantly decreased in the sera of some COVID-19 patients after preadsorption of the sera with S1-RBD, which indicated that antibodies against S1-RBD can cross-react with ACE2. To confirm this possibility, two monoclonal antibodies (mAbs 127 and 150) which could bind to both S1-RBD and ACE2 were isolated from S1-RBD-immunized mice. Measurement of the binding affinities by Biacore showed these two mAbs bind to ACE2 much weaker than binding to S1-RBD. Epitope mapping using synthetic overlapping peptides and hydrogen deuterium exchange mass spectrometry (HDX-MS) revealed that the amino acid residues P463, F464, E465, R466, D467 and E471 of S1-RBD are critical for the recognition by mAbs 127 and 150. In addition, Western blotting analysis showed that these mAbs could recognize ACE2 only in native but not denatured form, indicating the ACE2 epitopes recognized by these mAbs were conformation-dependent. The protein-protein interaction between ACE2 and the higher affinity mAb 127 was analyzed by HDX-MS and visualized by negative-stain transmission electron microscopy imaging combined with antigen-antibody docking. Together, our results suggest that ACE2-cross-reactive anti-S1-RBD antibodies can be induced during SARS-CoV-2 infection due to potential antigenic cross-reactivity between S1-RBD and its receptor ACE2.

A Cylindrical Ion Sensor Tip with a Diameter of 1.5 mm for Potentially Invasive Medical Application.

A fine cylindrical chemical sensor tip is developed with optical fiber in the core, surrounded by a transparent cylinder of photopolymer Norland Optical Adhesive 61 (NOA 61), and covered by a polymer hydrogel mixed with sensing molecules. The overall diameter is as small as 1.5 mm. pH response is demonstrated using two approaches of sensing materials: (i) absorbing probe Phenol Red mixed with Rhodamine 6G fluorescent dye and (ii) 8-hydroxypyrene-1,3,6-trisulfonic acid fluorescent probe. Both the optical excitation and fluorescence signal collection are through the optical fibers. A time resolution of 10 s is achieved for pH variations. Good linearity is observed in the physiological range from pH 7.0 to pH 8.6 with reversible and reproducible outcomes. For in vitro urea measurement, the sensor tip can distinguish 1, 3, and 5 mM urea solution, which is a crucial range in saliva urea concentration. The miniaturized tip with such simple cylindrical symmetry is designed to detect vital signs during minimally invasive surgeries and can be potentially accompanied with endoscopes to enter human bodies.

Functionalized dibenzo[g,p]chrysenes: variable photophysical and electronic properties and liquid-crystal chemistry.

The photophysical and electronic properties of dibenzo[ g, p]chrysenes bearing electron-rich and -deficient substituents vary markedly with these substituents. The chemistry of the first liquid-crystalline dibenzo[ g, p]chrysene is also described.

Violet Laser Diode Enables Lighting Communication.

Violet laser diode (VLD) based white-light source with high color rendering index (CRI) for lighting communication is implemented by covering with Y3Al5O12:Ce3+ (YAG:Ce) or Lu3Al5O12:Ce3+/CaAlSiN3:Eu2+ (LuAG:Ce/CASN:Eu) phosphorous diffuser plates. After passing the beam of VLD biased at 70 mA (~2I th ) through the YAG:Ce phosphorous diffuser, a daylight with a correlated color temperature (CCT) of 5068 K and a CRI of 65 is acquired to provide a forward error correction (FEC) certified data rate of 4.4 Gbit/s. By using the VLD biased at 122 mA (~3.5I th ) to excite the LuAG:Ce/CASN:Eu phosphorous diffuser with 0.85-mm thickness, a warm white-light source with a CCT of 2700 K and a CRI of 87.9 is obtained at a cost of decreasing transmission capacity to 2.4 Gbit/s. Thinning the phosphor thickness to 0.75 mm effectively reduces the required bias current by 32 mA to achieve the same CCT for the delivered white light, which offers an enlarged CRI of 89.1 and an increased data rate of 4.4 Gbit/s. Further enlarging the bias current to 105 mA remains the white-light transmission capacity at 4.4 Gbit/s but reveals an increased CCT of 3023 K and an upgraded CRI of 91.5.

The prognostic value of left ventricular global peak systolic longitudinal strain in chronic peritoneal dialysis patients.

BACKGROUND: Although left ventricular (LV) global systolic longitudinal strain (GLS) reliably and accurately assesses LV systolic function and is also a powerful prognostic predictor, the importance and prognostic value of GLS in end-stage renal disease patients receiving maintenance peritoneal dialysis (PD) remain unclear. This study sought to determine the prognostic value of GLS in chronic PD patients. METHODS: This prospective study collected clinical and echocardiographic data from 106 stable PD patients (50.0 ± 13.9 years, 45% male) in a dialysis unit of a university hospital. These patients were enrolled from April 2010 to June 2010 and followed until August 2013 (follow-up duration 30.3 ± 14.3 months). The primary outcomes were the presence of major adverse events (MAEs), defined as all-cause mortality, and major adverse cardiovascular cerebral events (MACCEs), i.e. cardiovascular death, cardiac hospitalization, and stroke. RESULTS: Twenty-nine patients (27%) reported a primary outcome. Patients with MAEs had worse LV systolic function (MAEs vs. no MAEs, - 14.8 ± 2.8 vs. - 17.1 ± 2.5%, p = 0.003). Using multivariate Cox regression analyses, being male, having a history of heart failure, diabetes mellitus, an increased pulse pressure (≥ 60 mm Hg), and GLS ≥ - 15% were independent predictors of MAEs. The independent risk factors of MACCEs were a history of diabetes mellitus, an increased pulse pressure, and GLS ≥ - 15%. After comparison of the overall log likelihood χ2 of the predictive power, GLS was found to add prognostic information to a model based on traditional risk factors. CONCLUSION: GLS ≥ - 15% provided additional prognostic information that allowed for the early identification of high-risk PD patients.

Preventive effects of ß-thujaplicin against UVB-induced MMP-1 and MMP-3 mRNA expressions in skin fibroblasts.

Solar UV radiation damages human skin by affecting skin tone and resiliency and leads to premature aging (photoaging). The skin damage is caused by the activation of the AP-1 transcription factor, which increases matrix metalloproteinase (MMP) expression and collagen degradation. An increase of interleukin (IL)-6 is also correlated with the activation of MMP-1 expression. ß-thujaplicin has shown both acaricidal and antimicrobial activities. Also, ß-thujaplicin has been shown to be protective against apoptosis due to the oxidative effects of UV irradiation. However, the effect of ß-thujaplicin on UVB-induced MMPs had not been investigated. In this study, after UVB exposure, MMP-1 and IL-6 production in human skin fibroblasts was examined in the presence of ß-thujaplicin, vitamin C, and vitamin E. The expression of MMP-1, MMP-3, tissue inhibitor of metalloproteinase (TIMP-1, TIMP-3) and procollagen mRNA was also investigated. Results showed that UVB-induced MMP-1 production was suppressed by the ß-thujaplicin treatment in a dose-dependent manner, but not by vitamin C and vitamin E. ß-thujaplicin also prevented the up-regulation of MMP-1 and MMP-3 mRNA. Moreover, the UVB-suppressed procollagen gene expression was restored to normal by ß-thujaplicin. Neither UVB nor ß-thujaplicin affected the mRNA expression of TIMP-1 and TIMP-3. The IL-6 production induced by UVB was lower in ß-thujaplicin treated fibroblasts than in the controls. In conclusion, this study shows the capability of ß-thujaplicin in preventing MMP-1 production due to UVB irradiation via inhibition of MMP gene expression. Importantly, the UVB-suppressed procollagen gene expression can be restored to normal by ß-thujaplicin. These findings indicate that ß-thujaplicin is a promising and potent agent to inhibit UVB-induced MMP-1 and MMP-3 gene expression in skin fibroblasts.

Design and synthesis of trithiophene-bound excited-state intramolecular proton transfer dye: enhancement on the performance of bulk heterojunction solar cells.

In an aim to harvest UV-near-visible (360-440 nm) photons as well as to increase the morphology in the bulk heterojunction solar cells, we report herein the strategic design, synthesis, and characterization of a novel excited-state intramolecular proton-transfer dye, 3-hydroxy-2-(5-(5-(5-(3-hydroxy-4-oxo-4H-chromen-2-yl)thiophen-2-yl)thiophen-2-yl)thiophen-2-yl)-4H-chromen-4-one (FT), which bears two key functional groups, namely 3-hydroxychromone chromophore and trithiophene backbone and is then exploited into the blends of regioregular poly(3-hexylthiophene) (RR-P3HT) and phenyl-C(61)-butyric acid methyl ester (PCBM). FT acts as an excellent UV-near visible absorber, which then undergoes excited-state intramolecular proton transfer, giving rise to an orange-red proton-transfer emission that was reabsorbed by P3HT via a Forster type of energy transfer. Introduction of FT to P3HT/PCBM blend films also improves the morphology of phase separated structure, in particular, enhances the interaction of P3HT chains and the hole mobility. In this work, under the optimized condition of P3HT: PCBM:FT of 15:9:2 in weight ratio, the best performance of the device B-FT2 revealed consistent enhancements in the efficiency (eta) 4.28% and short-circuit current (J(sc)) 12.53 mAcm(-2), which are higher than that (3.68% and 10.28 mAcm(-2)) of the best performance of the control device B (P3HT:PCBM 15:9 in weight ratio) by 16 and 22%, respectively.

[Regulation of Bcl-2 expression in ageing T cells by CD137 and CD28].

OBJECTIVE: To observe the effect of the costimulatory molecules CD137 and CD28 on Bcl-2 expression in T cells of mice with D-galactose-induced aging and natural aging. METHODS: Seven-week-old male BALB/c mice were injected daily with D-galactose (120 mg/kg) for 5 months to induce subacute aging, and 16-month-old male BALB/c mice served as the natural aging group. The spleen T cells of were isolated from the rats and stimulated in vitro with conA+IgG, conA+CD137 mAb or conA+CD28 mAb for 48 h. Bcl-2 expression of T cells was detected by flow cytometry and semi-quantitative RT-PCR. RESULTS: In the subacute aging group, Bcl-2 protein expression rate in the T cells stimulated with conA+IgG, conA+CD137 mAb and conA+CD28 mAb were (24.4-/+1.5)%, (34.4-/+2.4) %, and (45.1-/+2.7) %, which were (19.6-/+2.0) %, (26.3-/+1.9) %, and (48.5-/+2.2) % in the natural aging group, respectively. In vitro stimulation with conA+IgG, conA+CD137 mAb and conA+CD28 mAb resulted in expression rate of bcl-2 mRNA in the T cells of 0.309-/+0.039, 0.547-/+0.036, and 0.780-/+0.041 in the subacute aging group, and 0.283-/+0.038, 0.535-/+0.041, and 0.771-/+0.063 in the natural aging group, respectively. CONCLUSION: CD137 and CD28 can promote bcl-2 expression at both mRNA and protein level in T cells in aging mice, which may be one of the mechanisms through which CD137 and CD28 molecules inhibit aging T cell apoptosis and maintain their function.