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Metal halide perovskites have outperformed conventional inorganic semiconductors in direct X-ray detection due to their ease of synthesis and intriguing photoelectric properties. However, the operational instability caused by severe ion migration under a high external electric field is still a big concern for the practical application of perovskite detectors. Here, we report a 2D (BPEA)2PbI4 (BPEA = R-1-(4-bromophenyl)ethylammonium) perovskite with Br-substituted aromatic spacer capable of introducing abundant interactions, e.g., the molecular electrostatic forces between Br atoms and aromatic rings and halogen bonds of Br-I, in the interlayer space, which effectively suppresses ion migration and thus enables superior operational stability. Constructing direct X-ray detectors based on high-quality single crystals of (BPEA)2PbI4 results in a high sensitivity of 1,003 µC Gy-1 cm-2, a low detection limit of 366 nGy s-1, and an ultralow baseline drift of 3.48 × 10-8 nA cm-1 s-1 V-1 at 80 V bias. More strikingly, it also exhibits exceptional operational stability under high flux, long-time X-ray irradiation, and large working voltage. This work shows an integration of multiple interlayer interactions to stabilize perovskite X-ray detectors, providing new insights into the future design of perovskite optoelectronic devices toward practical application.
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Oxaliplatin, a platinum-based chemotherapy drug, causes neuropathic pain, yet effective pharmacological treatments are lacking. Previously, we showed that tetrandrine (TET), with anti-inflammatory properties, reduces mechanical allodynia in nerve-injured mice. This study explores the effect of TET on oxaliplatin-induced mechanical allodynia and gene changes in mice. Male C57BL/6J mice received oxaliplatin intraperitoneally to induce mechanical allodynia. Post-treatment with TET or vehicle, the mechanical withdrawal threshold (WMT) was assessed using von Frey filaments. TET alleviated oxaliplatin-induced mechanical allodynia. RNA sequencing identified 365 differentially expressed genes (DEGs) in the Control vs. Oxaliplatin group and 229 DEGs in the Oxaliplatin vs. TET group. Pearson correlation analysis of co-regulated DEGs and inflammation-related genes (IRGs) revealed 104 co-regulated inflammation-related genes (Co-IRGs) (|cor| > 0.8, P < 0.01). The top 30 genes in the PPI network were identified. Arg2, Cxcl12, H2-Q6, Kdr, and Nfkbia were highlighted based on ROC analysis. Subsequently, Arg2, Cxcl12, Kdr, and Nfkbia were further verified by qRCR. Immune infiltration analysis indicated increased follicular CD4 T cell infiltration in oxaliplatin-treated mice, reduced by TET. Molecular docking showed strong binding affinity between TET and proteins encoded by Arg2, Cxcl12, Kdr, and Nfkbia. In summary, TET may alleviate oxaliplatin-induced peripheral neuropathy in clinical conditions.
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AIMS: Infections are common complications after stroke and associated with unfavourable outcomes. We aimed to evaluate the efficacy and safety of prophylactic antibiotics for post-acute stroke infection. METHODS: We searched PubMed, Embase, the Cochrane Library, SinoMed, China National Knowledge Infrastructure, WanFang Data, China Science and Technology Journal Database, and clinical trial register platforms from inception to 15 February 2022. We included randomized clinical trials that evaluated the efficacy and safety of prophylactic antibiotics. Primary outcomes were mortality rate and incidence of pneumonia. The pooled risk ratio (RR) and mean differences with 95% confidence interval (CI) were calculated using the random or fixed-effect model depending on heterogeneity. The quality of evidence was evaluated using the Grading of Recommendations, Assessment, Development and Evaluations. RESULTS: Twelve studies (4809 participants) were included. There was no significant difference in the mortality rate (12 trials, n = 4740, RR 1.03 [95% Cl: 0.91-1.16], high-quality evidence), incidence of pneumonia (7 trials, n = 4352, RR 0.94 [95% CI: 0.79-1.11], high-quality evidence) and the incidence of adverse events between the prophylactic antibiotics and control groups. Prophylactic antibiotics significantly reduced the incidence of infections (8 trials, n = 4517, RR 0.72 [95% CI: 0.58-0.89], moderate-quality evidence) and urinary tract infections (7 trials, n = 4352, RR 0.39 [95% CI: 0.3-0.49], moderate-quality evidence). None of the subgroup analyses showed a significant difference in mortality or the incidence of pneumonia. CONCLUSION: For acute stroke patients, prophylactic antibiotics were significantly associated with fewer incidences of any infections and urinary tract infections without significant differences in mortality rate and pneumonia.
Asunto(s)
Neumonía , Accidente Cerebrovascular , Infecciones Urinarias , Humanos , Infecciones Urinarias/tratamiento farmacológico , Infecciones Urinarias/etiología , Infecciones Urinarias/prevención & control , Accidente Cerebrovascular/complicaciones , Accidente Cerebrovascular/tratamiento farmacológico , Neumonía/tratamiento farmacológico , Neumonía/epidemiología , Neumonía/prevención & control , Incidencia , Antibacterianos/efectos adversosRESUMEN
We present an erratum to our Letter [Opt. Lett.47, 3688 (2022)10.1364/OL.463637]. This erratum corrects subscript errors in Eq. (1), H1 and H2. These errors could confuse readers when they perform the derivation processes, but the errors do not affect our experimental results. Therefore, these corrections do not affect the results and conclusions of the original Letter.
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This Letter proposes a novel, to the best of our knowledge, intensity-modulation transmitter equipped with an optical intensity feedback (OIF) loop, which mitigates the holistic nonlinearity on both sides of intensity modulation and direct detection (IM/DD) transceivers from solely the transmitter side. In contrast to the recent effort on pre-distortion, we construct a negative feedback loop bridging the optical intensity of light-emitting diodes (LEDs) toward a sensor for nonlinearity perception to suppress the nonlinearity among all physical devices. In the meantime, we propose an analytical model for the feedback loop and an implementation scheme. The experimental results demonstrate a significant linearity improvement in the total harmonic distortion (THD) and the power gain flatness. More specifically, the average THD of the bipolar junction transistor (BJT)-based OIF transceiver is -49.4 dB (0.37%) and the minimum power gain variance is 0.0005, 0.0025% of the control group. As for the transceiver using a metal-oxide-semiconductor field-effect transistor (MOSFET), its average THD is -52.42 dB (0.25%) and the minimum power gain variance can reach 0.0026. Not only that, since the method only takes advantage of the negative feedback feature and dose not rely on any particular module, it has lower complexity and better applicability.
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The modulation bandwidth of a light-emitting diode is inversely proportional to the carrier lifetime, which changes with varying injected current. However, in conventional implementations of visible light communications, the influence of bias current is always emphasized, while the effects of modulation indices and signal components are ignored. In this Letter, it is the first time, to the best of our knowledge, that the mechanism on how modulated signal components impact modulation bandwidth is clarified. We reveal and interpret this impact by featuring the response at different modulation indices and intensity distributions mathematically and experimentally, proposing a series of theoretical approaches for the insight of modulation at a high index. This Letter donates a novel perspective on deciding appropriate configurations for modulators according to the modulation characteristics at a high index of the input signal.
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Discrete Fourier transform spread orthogonal frequency-division multiplexing (DFT-S-OFDM) has demonstrated its capability in reducing peak to average ratio (PAPR), while maintaining reliable transmissions. This paper investigates the application of DFT-S-OFDM technology in visible light communications (VLC), and reveals the mechanism on how a multiple lighting distributed layout affects its performance. In addition, an optimization approach of lighting layout is proposed through making a trade-off between the strong interfered areas and the maximum delay spread inside. Eventually, a Gbit/s DFT-S-OFDM based multiple lighting VLC downlink prototype is achieved for the first time in the form of real-time baseband modem and compact size components.