297 research outputs found

    Reverse Doping Asymmetry in Semiconductor Thin Films Using External Voltage

    Full text link
    Doping asymmetry is a notable phenomenon with semiconductors and a particularly longstanding challenge limiting the applications of most wide-band-gap semiconductors, which are inherent of spontaneous heavy n- or p-type doping because of their extreme band edges. This study theoretically shows that by applying a proper external voltage on materials during their growth or doping processes, we can largely tune the band edges and consequently reverse the doping asymmetry in semiconductor thin films. We take zinc oxide as a touchstone and computationally demonstrate that this voltage-assisted-doping approach efficiently suppresses the spontaneous n-type defects by around four orders under three distinct growth conditions and successfully generates p-type zinc oxide up to the lowest acceptor levels. The proposed approach is insensitive to materials, growth conditions, or defects origins, and thus offers a general solution to the doping asymmetry in semiconductor thin films

    Head-to-Head Comparison of TB-LAMP, Mycobacterial Culture and Adenosine Deaminase for Diagnosis of Pleural Tuberculosis in China

    Get PDF
    Objectives: The objective of the prospective single-center study was to investigate the diagnostic performance of Loop-Mediated Amplification test (TB-LAMP), mycobacterial culture and adenosine deaminase (ADA) for diagnosing pleural tuberculosis (TB) from the pleural effusions in a TB-endemic setting. Methods: We retrospectively analyzed patients suspected of having pleural TB in Weifang between March 2018 and October 2019. The PE samples were evaluated by smear microscopy, mycobacterial culture, TB-LAMP and ADA assay. Results: Overall, 170 patients with suggestive of pleural TB were retrospectively reviewed in this study, of which 125 were diagnosed as pleural TB. Among 125 pleural TB cases, 52 cases were identified by TB-LAMP, resulting in a sensitivity of 41.6%. When combing MGIT and TB-LAMP, 13 additional positive cases were detected compared to MGIT culture alone, demonstrating a sensitivity of 56.8%. The mean ADA levels were corelated with age, and the mean ADA value of <35 years group was significantly higher than that of ≥70 years group (p=0.0214). Conclusion: In conclusion, our data demonstrate the promising effectiveness of TB-LAMP in detection of MTB in concentrated PE specimens. The ADA levels are decreased with advanced age, highlighting the urgent need for confirmation of different cut-off values for various age group

    Comparison of the relative diagnostic performance of 68Ga-DOTA-IBA and 18F-NaF for the detection of bone metastasis

    Get PDF
    PurposeWe aimed to compare the relative diagnostic efficacy of 68Ga-Labeled DOTA-ibandronic acid (68Ga-DOTA-IBA) to that of18F-NaF PET/CT as a mean of detecting bone metastases in patients with a range of cancer typesMethodsThis study retrospectively enrolled patients with bone metastases associated with various underlying malignancies. All patients underwent both 68Ga-DOTA-IBA and 18F-NaF PET/CT scans. Histopathology and follow-up CT or MRI imaging results were used as reference criteria, with a minimum follow-up period of 3 months. The maximum Standardized Uptake Value (SUVmax) and number of bone metastases were recorded. The Target-Background Ratio (TBR) was calculated along with the detection rate, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of 68Ga-DOTA-IBA and 18F-NaF PET/CT imaging for overall and partial primary solid tumor bone metastases. Pearson chi-square test, McNemar test, and Kappa test was conducted to assess the correlation and consistency of diagnostic efficiency between the two imaging agents. Receiver Operating Characteristic curve (ROC curve) was performed to compare diagnostic performance and the area under the curve of the two imaging agents, determining optimal critical values for SUVmax and TBR in diagnosing bone metastasis. Differences in SUVmax and TBR values between the two imaging agents for detecting bone metastases were analyzed using the Wilcoxon signed rank test. The difference was statistically significant when P < 0.05ResultsA total of 24 patients (13 women and 11 men) were included in this study, with a mean age of 52 (interquartile range, 49-64 years). The detection rate, sensitivity, specificity, PPV, NPV, accuracy, and AUC of 68Ga-DOTA-IBA and 18F-NaF PET/CT for bone metastases were 81%, 90%, 62%, 95%, 43%, 88%, 0.763, and 89%, 99%, 59%, 95%, 89%, 95%, 0.789, respectively. There was no significant difference between the two imaging methods (P < 0.01), and there was a significant correlation (X2=168.43, P < 0.001) and a strong consistency (Kappa=0.774,P < 0.001) between the diagnostic results of the two imaging agents. The SUVmax values of lesions measured by 68Ga-DOTA-IBA and 18F-NaF imaging in 22 patients with bone metastasis were 5.1 ± 5.4 and 19.6 ± 15.1, respectively, with statistically significant differences (P<0.05). The TBR values of the two imaging methods were 5.0 ± 5.0 and 6.7 ± 6.4, respectively, with statistically significant differences (P<0.05). The AUC of the SUVmax of 68Ga-DOTA-IBA and 18F-NaF curves were 0.824 and 0.862, respectively, with no statistically significant difference (P=0.490). No significant difference was found in the AUC of the TBR of 68Ga-DOTA-IBA and 18F-NaF (0.832 vs 0.890; P=0.248). Subgroup analysis showed significant correlation between the two imaging agents in the diagnosis of bone metastases in lung cancer and breast cancer, with consistent diagnostic results. However, in the diagnosis of bone metastases in prostate cancer, there was a significant difference (P<0.001) and lack of consistency (P=0.109)ConclusionThe diagnostic efficacy of 68Ga-DOTA-IBA for bone metastasis lesions is comparable to that of 18F-NaF. This finding holds significant clinical importance in terms of diagnosis of bone metastasis and selecting treatment plans for patients with malignant tumor

    Reversible tricolour luminescence switching based on a piezochromic iridium(iii) complex

    Get PDF
    On the basis of rational molecular design, the tricolour luminescence switching of an Ir(III) complex is achieved for the first time. The transformation between two crystalline states and an amorphous state is responsible for the switching behaviour of this complex between blue, green and yellow states. Solvent molecules are shown to play a crucial role in the crystallization and luminescence processes

    Cascaded multiplier-free implementation of adaptive anti-jamming filter based on GNSS receiver

    Get PDF
    Evaluating the computational complexity is critical for assessing the time-domain anti-jamming performance of GNSS receivers. The multiplier is the core component that contributes to the computational complexity in time-domain anti-jamming. However, current algorithms aimed at reducing the complexity of time-domain anti-jamming typically concentrate on shortening the filter length, which fails to address the high computational complexity introduced by the use of multipliers. This paper introduces a cascaded multiplier-free approach for implementing time-domain anti-jamming in navigation receivers. We propose a numerical power decomposition technique based on optimal Canonical Signed Digit coding and coefficient decomposition. By substituting the multiplier with minimal adder and shift operations, the computational complexity of the anti-jamming filter with a high quantization bit-width can be considerably decreased. An optimization strategy is presented, and the low-complexity multiplier-free technique is applied to the time-domain anti-jamming filter. Compared to the traditional Canonical Signed Digit multiplier-free technique, our method can reduce the components required for a 12-bit quantization anti-interference filter by one adder, 20 shift operations, and five coded word lengths, while maintaining a pseudo-range measurement deviation below 0.27 ns

    K6PC-5 Activates SphK1-Nrf2 Signaling to Protect Neuronal Cells from Oxygen Glucose Deprivation/Re-Oxygenation

    Get PDF
    Background/Aims: New strategies are required to combat neuronal ischemia-reperfusion injuries. K6PC-5 is a novel sphingosine kinase 1 (SphK1) activator whose potential activity in neuronal cells has not yet been tested. Methods: Cell survival and necrosis were assessed with a Cell Counting Kit-8 assay and lactate dehydrogenase release assay, respectively. Mitochondrial depolarization was tested by a JC-1 dye assay. Expression levels of nuclear factor erythroid 2-related factor 2 (Nrf2) signaling components were examined by quantitative real-timePCR and western blotting. Results: K6PC-5 protected SH-SY5Y neuronal cells and primary murine hippocampal neurons from oxygen glucose deprivation/re-oxygenation (OGDR). K6PC-5 activated SphK1, and SphK1 knockdown by targeted short hairpin RNA (shRNA) almost completely abolished K6PC-5-induced neuronal cell protection. Further work showed that K6PC-5 inhibited OGDR-induced programmed necrosis in neuronal cells. Importantly, K6PC-5 activated Nrf2 signaling, which is downstream of SphK1. Silencing of Nrf2 by targeted shRNA almost completely nullified K6PC-5-mediated neuronal cell protection against OGDR. Conclusion: K6PC-5 activates SphK1-Nrf2 signaling to protect neuronal cells from OGDR. K6PC-5 might be a promising neuroprotective strategy for ischemia-reperfusion injuries

    Transcriptional and Translational Relationship in Environmental Stress: RNAseq and ITRAQ Proteomic Analysis Between Sexually Reproducing and Parthenogenetic Females in Moina micrura

    Get PDF
    Moina micrura is a kind of small-bodied water flea within the family Moinidae. Similar to Daphnia, M. micrura could also switch its reproduction mode from parthenogenetic female (PF) to sexual female (SF) to adapt to the external environment. To uncover the mechanisms of reproductive switching in M. micrura, we used both RNA-Seq and iTRAQ analyses to investigate the differentially expressed genes (DEGs) and their protein products between SF and PF in M. micrura. A total of 1665 DEGs (702 up-regulated, 963 down-regulated) and 600 differentially expressed proteins (DEPs) (102 up-regulated, 498 down-regulated) were detected in SF. Correlation analyses indicated that 31 genes were expressed significantly differentially at both transcriptomic and proteomic levels, including 15 up-regulated genes and 16 down-regulated genes in SF. Meanwhile, our data also showed that 528 DEPs have discordant expression at transcript level, implying post-transcriptional (including translational) regulation. These top up-regulated genes and their protein products in SF were mainly grouped into the globin-related family, vitellogenin-related family, cuticle-related family, Hsp-related family and methyltransferases-related family, which were all involved in the reproductive switching in Daphnia. In contrast, a cluster of orthologous groups revealed that up-regulated genes and their protein products in PF were strongly associated with the metabolic process, which may be responsible for rapid population proliferation in M. micrura
    corecore