Challenges and developments for the blue perovskite nanocrystal light-emitting diodes.

Perovskite nanomaterials have been highly thought as next-generation light emitters after recent development owing to their benefits of simple synthesis, low-cost, large-area, and wide color gamut. Encouragingly, the external quantum efficiencies (EQEs) of green, red, and near-infrared perovskite light-emitting diodes (PeLEDs) have exceeded more than 20%. However, the performance of the blue PeLEDs is still lower than other analogs, which severely limits the applications of PeLEDs in future full-color displays. Herein, we have reviewed the advances in blue perovskite NCs and their applications in blue PeLEDs. Promising blue perovskite emitters and strategies for fabricating highly efficient blue PeLEDs based on perovskite NCs are investigated and highlighted. Moreover, we point out the main challenges in blue perovskite NC LEDs including low electroluminescence efficiency (EL), spectral instability, the difficulty of charge injection, and device optimization. The perspectives for the further development of blue PeLEDs are also presented.

Formation of Efficient Quasi-All-Polymer Solar Cells by Synergistic Effect of the Ternary Strategy and Solid Additives.

All-polymer solar cells (all-PSCs) have been widely studied owing to their unique mechanical flexibility and stability. However, all-PSCs have a lower efficiency than small-molecule acceptor-based PSCs. In the work, a ternary quasi-all-polymer solar cell (Q-all-PSC) using a synergy of the ternary strategy and solid additive engineering is reported. The introduction of PC71BM can not only match the energy level of the photoactive materials with an improved open circuit voltage (VOC) of the ternary devices but also enhance photon capture, which can improve short circuit current density. It is found that there is effective charge transfer between PC71BM and PY-IT, which can form an electron transport channel and promote efficient charge transport. Moreover, the introduction of PC71BM made the PM6/PY-IT/PC71BM ternary blends more crystalline while slightly reducing phase separation, resulting in a suitable domain size. Importantly, by introducing a high dielectric-constant PFBEK solid additive as the fasten matrix, the Q-all-PSC's efficiency can reach 16.42%. This method provides a new idea for future research on all-polymer solar cells.

Ultrafast Response of Centimeter Scale Thin CsPbBr3 Single Crystal Film Photodetector for Optical Communication.

The photodetector (PD) is the key component to realize efficient optoelectronic conversion signal in the visible light communication (VLC) system. The response speed directly determines the bandwidth of the whole system. Metal halide perovskite is a neotype of low-cost solution processing semiconductor, with strong optical absorption, low trap density, and high carrier mobility, thus has been widely explored in photoelectric detection applications. However, previously reported perovskite polycrystalline photodetectors exhibit limited response speed due to the existence of grain boundaries. Here, an improved confined space method is developed through adjusting the heating area to control nucleation, resulting in centimeter scale fully inorganic perovskite CsPbBr3 thin single crystal films (SCFs) (<40 µm). The smooth surface and high crystallinity of CsPbBr3 SCFs render admirable exciton lifetime. The planar metal-semiconductor-metal photodetector using CsPbBr3 SCF as the photosensitive layer demonstrates a limit response time of 200/300 ns and a VLC within 100-500 kHz frequency for both 365 nm and white light, which is superior to previously reported CsPbBr3 polycrystalline film and single crystal photodetectors.

Light-initiated chemiluminescent assay of 17ß-estradiol metrological traceability system established by manufacturer according to ISO17511:2020 and basic performance evaluation performed by clinical end-users.

BACKGROUND: In order to ensure the accuracy of the product, we established 1st model of metrological traceability hierarchy for light-initiated chemiluminescent assay (LICA) of 17ß-estradiol (E2 ) at the manufacturer, based on International Organization for Standardization (ISO) 17511:2020. Moreover, we verified/validated the basic performance (such as matrix effect and long-term stability of end-user IVD MD calibrator, precision, linearity interval, accuracy/ trueness, and detection capability) at the clinical end-user. METHODS: Human serum samples were used in this study. E2 was detected by mass spectrometry (MS) and LICA. The metrological traceability of LICA for E2 was established according to ISO 17511: 2020 standards, and pools of human samples were used as the m.3. secondary calibrator. Precision was validated according to Clinical and Laboratory Standards Institute (CLSI) EP05-A3. The linear interval was verified according to CLSI EP06-ED2. Comparison of accuracy and trueness of E2 with MS and Roche according to CLSI EP09-A3. The detection capability was validated according to EP17-A2. Matrix effect and long-term stability evaluation of end-user IVD MD calibrator were carried out according to CLSI EP14-A2, EP25-A. Statistical software was used for data analyses. RESULTS: The use of pools of human samples and fine adjusting calibrators ensured the accuracy of end-user test results. The metrological traceability of LICA for E2 was established. It showed excellent precision, meeting the requirements of allowable imprecision (7.5%). The allowable deviation from linearity (ADL) of 5% was allowed to show a good linear interval (12.52-4167.25 pg/ml). The accuracy/ trueness was verified, and relative deviation in the medical decision level met the performance specification of 10.03% compared with MS or Roche. The validated limit of blank, limit of detection, and limit of quantitation of E2 were 4.95 pg/ml, 8.93 pg/ml, and 9.88 pg/ml, respectively (the allowed imprecision is 20.00%). The interference rate of E2 ranged from -5.5% to 6.6%. CONCLUSION: LICA showed high sensitivity, high specificity, excellent precision, wide linearity interval, IVD MD calibrator has long-term stability, and no matrix effect. The metrological traceability of E2 established by using pools of human samples as M.3. can deliver accuracy to the end-user IVD MD and show good consistency with MS and Roche.

Triplet versus doublet neoadjuvant chemotherapy regimens for locally advanced gastric cancer: a propensity score matching analysis.

BACKGROUND: To investigate the differences between doublet and triplet neoadjuvant chemotherapy (NAC) regimens in efficacy and safety profile. METHODS: A total of 227 locally advanced gastric cancer (LAGC) patients who received NAC and sequential radical gastrectomy were reviewed. After propensity score matching (PSM), 140 patients with similar baseline characteristics were selected. Among them, 70 received doublet NAC regimens consisted of platinum and fluorouracil; the other 70 received triplet NAC regimens consisted of docetaxel, platinum, and fluorouracil. RESULTS: The efficacy of doublet and triplet regimens was comparable after propensity score matching in terms of tumor regression (pathological complete response, Doublet 11.4% vs. Triplet 15.7%, p = 0.642), achieving of R0 resection (Doublet 88.6% vs. Triplet 88.6%, p = 1), 1-year disease-free survival (DFS) (Doublet 77.1% vs. Triplet 68.6%, p = 0.178), 3-years overall survival (OS) (Doublet 54.3% vs. Triplet 60.9%, p = 0.941). Post-surgery complications were more common in the triplet cohort (Doublet 5.7% vs. Triplet 27.1%, p = 0.001), especially abdominal infection (Doublet 0% vs. Triplet 11.1%, p = 0.001). CONCLUSIONS: A more intense preoperative triplet NAC regimen does not bring extra downstage effect and survival benefit compared to a doublet regimen. It may even result in a higher risk of post-surgery complications.

Carrier Diffusion and Recombination Anisotropy in the MAPbI3 Single Crystal.

MAPbI3, one of the archetypical metal halide perovskites, is an exciting semiconductor for a variety of optoelectronic applications. The photoexcited charge-carrier diffusion and recombination are important metrics in optoelectronic devices. Defects in grain interiors and boundaries of MAPbI3 films cause significant nonradiative recombination energy losses. Besides defect impact, carrier diffusion and recombination anisotropy introduced by structural and electronic discrepancies related to the crystal orientation are vital topics. Here, large-sized MAPbI3 single crystals (SCs) were grown, with the (110), (112), (100), and (001) crystal planes simultaneously exposed through the adjusting ratios of PbI2 to methylammonium iodide (MAI). Such MAPbI3 SCs exhibit a weak n-type semiconductor character, and the Fermi levels of these planes were slightly different, causing a homophylic p-n junction at crystal ledges. Utilizing MAPbI3 SCs, the photoexcited carrier diffusion and recombination within the crystal planes and around the crystal ledges were investigated through time-resolved fluorescence microscope. It is revealed that both the (110) and (001) planes were facilitated to be exposed with more MAI in the growth solutions, and the photoluminescence (PL) of these planes manifesting a red-shift, longer carrier lifetime, and diffusion length compared with the (100) and (112) planes. A longer carrier diffusion length promoted photorecycling. However, excessive MAI-assisted grown MAPbI3 SCs could increase the radiative recombination. In addition, it revealed that the carrier excited within the (001) and (112) planes was inclined to diffuse toward each other and was favorable to be extracted out of the grain boundaries or crystal ledges.

Highly In-Plane Polarization-Sensitive Photodetection in CsPbBr3 Single Crystal.

The fully inorganic perovskite lead cesium bromide single crystal (CsPbBr3 SC) is considered as an excellent candidate semiconductor for photodetectors because of its superior humidity resistance, thermal stability, and light stability compared with organic-inorganic hybrid perovskites as well as its photoelectric properties such as large light absorption coefficient and ultralong carrier migration distance. In this Letter, we utilize the inverse temperature solubility of CsPbBr3 in ternary solvents to grow large-sized CsPbBr3 SCs. By the use of the (101) plane, CsPbBr3 SC-based photodetectors are fabricated, which exhibit excellent polarized light response characteristics. The photocurrent relies on the polarization angle in a sinusoidal fashion and shows strong anisotropic optoelectronic properties. The photodetection performance perpendicular to the y axis is significantly higher than that parallel to the y axis, and the dichroic ratio under 405 nm illumination at a bias voltage of 1 V reaches 2.65. The experimental results are consistent with the results of first-principles calculations.

[Comparison and bias estimation of three methods in determination of glycated hemoglobin A1c].

OBJECTIVE: To evaluate the bias of three different methods in determination of glycated hemoglobin A1c (HbA1c). METHODS: According to Clinical and Laboratory Standards Institute (CLSI)EP9-A3 document, 40 serum specimens among linear range were tested by immunoturbidimetry assay (Roche Tina-quant), capillary electrophoresis (Sebia Minicap FP), high performance liquid chromatography system (HPLC, Trinity Biotech Premier Hb 9210™). RESULTS were analyzed by pairwise comparision. The difference plots and scatter plots were analyzed. The results of outliers were examined by extreme studentized deviate (ESD) method. The best regression model was chosen to fit the regression equation and the biases were calculated at the level of medical decision and judged the comparability according to the half of Tea acceptance standard. RESULTS: Scatter plots and ESD results showed good correlation among test results of 40 samples, no abnormal values were found. Based on proportional difference deviation plots, proportional difference rank order deviation plots, numerical deviation plots and ranked order difference plots, weighted least squares (WLS) (Roche(X) vs sebia(Y1)), ordinary linear regression (OLR) (Roche(X) vs Trinity (Y2)) and Deming (Sebia(Y1) vs Trinity(Y2)) were chosen to fit regression analysis model. The regression equations were Y1 =-0.420 3+ 1.052 7X, Y2 =-0.174 0+ 1.027 0X, Y2=0.423 1+ 0.959 0Y1, respectively. Assuming the HbA1c medical decision points of 10%, 16% to regression equation, the proportional biases were 1.06% and 2.61% at Roche(X) and sebia(Y1) system, 0.96% and 1.60% at Roche(X) and Trinity (Y2) system, 0.13% and -1.47% at Sebia(Y1) and Trinity(Y2) system respectively, which were all lower than the acceptable values. CONCLUSION: The measurement values of HbA1c by capillary electrophoresis (Sebia Minicap FP), HPLC (Trinity Biotech Premier Hb 9210™) and immunoturbidimetry assay (Roche Tina-quant), are comparable.

Social Cultural Influences on Breast Cancer Views and Breast Health Practices Among Chinese Women in the United Kingdom.

BACKGROUND: Incidence rates for breast cancer have increased significantly among Chinese women, accompanied by low utilization of breast screening and delay in symptom presentation. OBJECTIVE: The aims of this study were to explore (1) views on breast cancer and breast health among Chinese women in the United Kingdom and (2) the potential influence of social and cultural context on views and screening behavior. METHODS: Qualitative interviews were carried out with 22 Chinese women. Pertinent aspects of Grounded Theory methods, including simultaneous data collection and analysis, constant comparison, and memo writing, were used. RESULTS: Four themes emerged: cultural views on breast cancer, information sources and knowledge, breast screening practice, and views on healthcare services. The theme views on breast cancer had 3 subthemes: a fearful disease, taboo, and fatalism. Aspects of traditional Chinese culture had important influences on Chinese women's views on breast cancer. Self-care formed the most significant strategy to promote health and prevent illness. Although the study found high utilization of breast screening when offered, only 6 women reported breast awareness practices. CONCLUSIONS: This study found that traditional beliefs were not the sole determinant of breast health behavior. The way in which breast screening services are offered in the United Kingdom may reduce the significance of cultural views and shape individuals' health behavior. IMPLICATIONS FOR PRACTICE: Findings indicate that information on breast awareness should be delivered to this group of women in Chinese by health professionals through Chinese mass media.