Zr‐based porphyrin metal–organic framework (MOF‐525) nanocrystals with a crystal size of about 140 nm are synthesized and incorporated into perovskite solar cells. The morphology and crystallinity of ...the perovskite thin film are enhanced since the micropores of MOF‐525 allow the crystallization of perovskite to occur inside; this observation results in a higher cell efficiency of the obtained MOF/perovskite solar cell.
Abstract
The supernova remnant (SNR) 30 Dor B is associated with the H
ii
region ionized by the OB association LH99. The complex interstellar environment has made it difficult to study the physical ...structure of this SNR. We have used Hubble Space Telescope H
α
images to identify SNR shocks and deep Chandra X-ray observations to detect faint diffuse emission. We find that 30 Dor B hosts three zones with very different X-ray surface brightnesses and nebular kinematics that are characteristic of SNRs in different interstellar environments and/or evolutionary stages. The ASKAP 888 MHz map of 30 Dor B shows counterparts to all X-ray emission features except the faint halo. The ASKAP 888 and 1420 MHz observations are used to produce a spectral index map, but its interpretation is complicated by the background thermal emission and the pulsar PSR J0537−6910's flat spectral index. The stellar population in the vicinity of 30 Dor B indicates a continuous star formation in the past 8–10 Myr. The observed very massive stars in LH99 cannot be coeval with the progenitor of 30 Dor B’s pulsar. Adopting the pulsar’s spin-down timescale, 5000 yr, as the age of the SNR, the X-ray shell would be expanding at ∼4000 km s
−1
and the post-shock temperature would be 1–2 orders of magnitude higher than that indicated by the X-ray spectra. Thus, the bright central region of 30 Dor B and the X-ray shell requires two separate SN events, and the faint diffuse X-ray halo perhaps other older SN events.
This study presents gallium-doped zinc oxide (ZnO:Ga, GZO) thin films. GZO thin films with both high transparency and low sheet resistance were prepared by RF sputtering and then post-annealed under ...nitrogen and hydrogen forming gas. With post-annealing at 450 °C, the proposed films with a film thickness of 100 nm showed high transparency (94%), while the sheet resistance of the films was reduced to 29 Ω/square, which was comparable with the performances of commercial indium tin oxide (ITO) samples. Post-annealing under nitrogen and hydrogen forming gas enhanced the films’ conductivity while altering the thin-film composition and crystallinity. Nitrogen gas played a role in improving the crystallinity while maintaining the oxygen vacancy of the proposed films, whereas hydrogen did not dope into the thin film, thus maintaining its transparency. Furthermore, hydrogen lowered the resistance of GZO thin films during the annealing process. Then, the detailed mechanisms were discussed. Hydrogen post-annealing helped in the removal of oxygen, therefore increasing the Ga3+ content, which provided extra electrons to lower the resistivity of the films. After the preferable nitrogen/hydrogen forming gas treatment, our proposed films maintained high transparency and low sheet resistance, thus being highly useful for further opto-electronic applications.
Perovskite thin films directly impact solar cell properties, making defect reduction crucial in perovskite solar cell research. In our study, we used perovskite quantum dots in the anti-solvent to ...act as nucleation centers in MAPbI3 thin films. These centers had lower nucleation barriers than homogeneous nucleation, improving perovskite crystallinity, reducing defects, and extending carrier lifetime. Fine-tuning the energy band also enhanced carrier transport. The most effective results were obtained using CsPb(Br0.5 I0.5)3 perovskite quantum dots. The resulting device, ITO/SnO2/MAPbI3 (300 nm)/spiro-OMeTAD (200 nm)/Ag (100 nm), achieved a 12.88% power conversion efficiency, a 16% increase from the standard element. The modified device maintained approximately 95% of its efficiency over 100 h in a 70% humidity environment.
This investigation aims to analyze the effect of homogenization heat treatment at 1240 °C for 2 and 6 h on the hardness, distribution, morphology, and chemical composition of the δ-ferrite and sigma ...phases in 316L stainless steel cast billet. A field emission scanning electron microscope, combined with electron back-scattered diffraction, a field emission electron probe microanalyzer with a wavelength dispersive spectrometer, and a Vickers microhardness tester are applied to identify various phase evolutions in the cast billet. The morphology of the δ-ferrite and sigma phases in the austenite matrix of the 316L cast billet are strongly related to the subsequent hot and cold wire drawings. The homogenization heat treatment is expected to provide a driving force to form spheroid interdendritic δ-ferrite and to minimize the amount of the brittle sigma intermetallic compound in the austenite matrix. The homogenization heat treatment at 1240 °C effectively spheroidized all δ-ferrites into blunt ones in the cast billet. The transformation of δ-ferrite into sigma is dominated by temperature and cooling rate. The fast air cooling after homogenization between 1240 and 850 °C retards the precipitation of the sigma in the δ-ferrite. There are two δ-ferrite transformation mechanisms in this experiment. The direct transformation of the δ-ferrite into sigma is observed in the as-cast 316L stainless steel billet. In contrast, the eutectoid transformation of the δ-ferrite into the sigma and austenite dominates the 316L cast billet homogenized at 1240 °C, with a slow furnace cooling rate.
This study investigated the effect of uteroplacental insufficiency (UPI) on renal development by detecting metabolic alterations in the kidneys of rats with intrauterine growth restriction (IUGR). On ...gestational day 17, pregnant Sprague Dawley rats were selected and allocated randomly to either the IUGR group or the control group. The IUGR group received a protocol involving the closure of bilateral uterine vessels, while the control group underwent a sham surgery. The rat pups were delivered on gestational day 22 by natural means. Pups were randomly recruited from both the control and IUGR groups on the seventh day after birth. The kidneys were surgically removed to conduct Western blot and metabolomic analyses. IUGR was produced by UPI, as evidenced by the significantly lower body weights of the pups with IUGR compared to the control pups on postnatal day 7. UPI significantly increased the levels of cleaved caspase-3 (p < 0.05) and BAX/Bcl-2 (p < 0.01) in the pups with IUGR. Ten metabolites exhibited statistically significant differences between the groups (q < 0.05). Metabolic pathway enrichment analysis demonstrated statistically significant variations between the groups in the metabolism related to fructose and mannose, amino and nucleotide sugars, and inositol phosphate. UPI alters kidney metabolism in growth-restricted newborn rats and induces renal apoptosis. The results of our study have the potential to provide new insights into biomarkers and metabolic pathways that are involved in the kidney changes generated by IUGR.
Development of wide-color gamut white light-emitting diodes (WLEDs) for displays, with nitride-based phosphors and conventional core-shell quantum dots (QDs) such as InP, CdSe, and all-inorganic ...CsPbI3 perovskite quantum dots due to their excellent optoelectronic properties performance, is an excellent candidate for new optoelectronic applications.
However, in backlight applications, the color gamut of perovskite quantum dots will be reduced due to the matching degree of color filter, which will limit its application in wide color gamut. To address these issues, in this paper, we propose a novel approach, namely, formamidine acetate (FA+) cationic doping, in CsPbI3 system synthesized at room temperature by organic-inorganic ligand passivation method which can effectively maintain structural stability. At the same time, the PL emission band of CsPbI3 is increased by doping FA + cations and the color gamut range is improved. We will discuss this change in detail, and quantum dot films using spin coating method can be maintained for a month in atmospheric conditions. For practical applications, the color gamut range can reach 133%. Therefore, our proposed perovskite quantum dots, FAxCs1-xPbI3, have great potential for application in wide color gamut displays.
•The doping of organic cations effectively maintains the structural stability of CsPbI3.•FA cationic doping and facile room-temperature synthesis of FAxCs1-xPbX3 quantum dots.•FAxCs1-xPbX3 powder is combined with Mini-LED to form a wide color gamut white light LED element.
Recommended treatment regimen for human immune deficiency virus (HIV) infection includes protease inhibitors/ritonavir (PIs/r) combined with two‐nucleoside reverse‐transcriptase inhibitors (2NRTIs), ...which enable to achieve and maintain viral suppression, restore, and preserve immune function. However, there were inconsistent findings on the levels of interleukin‐6 (IL‐6) levels. Systematic review and meta‐analysis were performed to quantify the pooled effects of PIs/r‐based antiretroviral therapy (ART) on serum/plasma IL‐6 levels in people living with the HIV (PLHIV). PubMed, Web of Science, and Embase were searched from the earliest record to November 4, 2020. Data analysis was conducted on Stata version 16 and Review Manager 5.3. A random‐effect model was used to compute a pooled effect size and weighted mean difference (WMD) was considered the summary effect size. Heterogeneity between studies was estimated by Cochrane's Q test (χ2 test) and I2 statistic and subgroup analysis were performed to explore the source of heterogeneity. Initial search identified 3098 records and 5 studies (7 trials) met inclusion criteria. The pooled mean difference in serum/plasma IL‐6 levels from baseline to follow‐up was 0.534 pg/ml (95% confidence interval: −0.012, 1.08, P = 0.05, I2 = 76.4%). In subgroup analysis, there was a significant association between increased serum/plasma IL‐6 levels and age group ≥ 35 years old, baseline CD4+ counts < 350 cell/mm3, and mean viral load ≥ 4.5 log10 copies/ml. We found that serum/plasma IL‐6 levels increased after combined ART among treatment‐naïve individuals who initiated a successful combination of PIs/r with 2NRTIs. This result also highlights the need to monitor serum/plasma IL‐6 levels during antiviral therapy, which may aid in the effective future treatment of systemic inflammation and related disorders following elevated IL‐6 levels.
In recent years, the demand for detection and diagnostic methods has consistently risen due to the aging of the population and the increase in the number of patients with chronic diseases. Label-free ...biomedical detection techniques have emerged as indispensable instruments for diagnosing a variety of diseases. The development of label-free and highly sensitive near-infrared (NIR) biomedical detection technology has attracted considerable attention. As a label-free, swift, and cost-effective analytical technique, it has demonstrated immense potential for a wide range of applications. We successfully assembled FAPbI3 near-infrared perovskite quantum dots (NIPQDs) into SiO2 shells using a rapid room-temperature atmospheric synthesis method, obtaining monodisperse FAPbI3@SiO2 nanocomposites (NCs) with a high photoluminescence quantum yield (PLQY) of 72%. Additionally, the incorporation of hydrophobic multi-branched trioctylphosphine oxide effectively passivated the surface defects of FAPbI3 NIPQDs and suppressed the hydrolysis rate of tetraethoxysilane, enabling the formation of a highly stable and high PLQY nanoscale-particle level within the FAPbI3@SiO2 core–shell structure. Notably, we successfully incorporated FAPbI3@SiO2 core–shell NCs onto InGaN blue chip as NIR excitation light sources for surface plasmon resonance sensing platforms, providing a novel platform for bioanalytical detection. With a detection sensitivity of 6302.5 nm/RIU, the system demonstrated high sensitivity, stability, and dependability. This achievement expands the biomedical research field’s capacity for diagnosis, monitoring, and treatment.
In some medical laboratory tests, a sampling method via intravenous injection is required. Previous research pointed out using near-infrared (NIR) light vein detectors to reduce erroneous injections. ...Therefore, low-cost, high-efficiency and stability NIR phosphors are highly essential. Herein, high-stability, ultrathin SiO2 wrapped NIR-CH(NH2)2PbI3 (FAPbI3) perovskite nanocrystals (NCs) are successfully manufactured via one-step method at room temperature atmospheric synthesis. By optimizing the hydrolytic condensation conditions of tetraethoxysilane (TEOS), the resulting FAPbI3@SiO2 perovskite NCs phosphors exhibits a high photoluminescence quantum yields (PLQYs) of 57.2% and improves water resistance and thermostability. The low-cost NIR light-emitting diodes (NIR-LEDs) fabricated by coating NIR-FAPbI3@SiO2 perovskite NCs phosphors on commercial blue InGaN LEDs chip demonstrated a ∼787 nm EL spectra of NIR-LEDs under the startup voltage of 2.6 V. Even after 12 h of continuous working, no significant changes were observed in the EL spectra of the NIR-LEDs, which indicates that NIR-FAPbI3@SiO2 perovskite NCs phosphor has high capacity in biological applications.
