51 research outputs found

    Security boundaries of an optical power limiter for protecting quantum key distribution systems

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    Unauthorized light injection has always been a vital threat to the practical security of a quantum key distribution (QKD) system. An optical power limiter (OPL) based on the thermo-optical defocusing effect has been proposed and implemented, limiting the injected hacking light. As a hardware countermeasure, the performance of the OPL under various light-injection attacks shall be tested to clarify the security boundary before being widely deployed. To investigate the OPL's security boundary in quantum cryptography, we comprehensively test and analyse the behavior of OPL under continuous-wave (c.w.) light-injection attacks and pulse illumination attacks with pulses' repetition rate at 0.5-Hz,40-MHz, and 1-GHz. The testing results illuminate the security boundary of the OPL, which allows one to properly employ the OPL in the use cases. The methodology of testing and analysis proposed here is applicable to other power-limitation components in a QKD system.Comment: 14 pages, 13 figure

    Prenatal detection of chromosomal abnormalities and copy number variants in fetuses with corpus callosum agenesis

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    Objectives: The corpus callosum is the main pathway that connects interhemispheric communication. Agenesis of corpus callosum (ACC) have not consistently detected replicate genetic risk factors, potentially due to Etiological heterogeneity of this trait. This study aimed to retrospectively analyze the molecular basis for the ACC and the potential genotyping-phenotyping association and provide the basis for genetic counselling. Material and methods: Karyotyping and chromosomal microarray analysis were performed for copy number variants. Results: Three cases had 1p36 deletions, two cases had 2q31.2 and 2p16.3 microdeletions, one case had microdeletion of Xq26.3q27.1, five cases involved derived chromosomes due to unbalanced translocations. These cases had variable deletions and duplications with partial overlapping. Phenotypically, besides agenesis of corpus callosum and other brain morphological abnormalities as well as heart abnormalities. Conclusions: ACC may occur alone or be related to other abnormal clinical phenotypes, and its genetic mechanism is very complicated. These results revealed ACC is associated with a variety of chromosomal abnormalities. The findings of the present study expand the genotypes associated with ACC, and further delineation of the genotype–phenotype correlations for ACC. With current applications of chromosome microarray analysis, congenital submicroscopic copy-number variations in fetuses can be detected more effectively

    On correlation between canopy vegetation and growth indexes of maize varieties with different nitrogen efficiencies

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    Studying the canopy spectral reflection characteristics of different N-efficient maize varieties and analyzing the relationship between their growth indicators and spectral vegetation indices can help the breeding and application of N-efficient maize varieties. To achieve the optimal management of N fertilizer resources, developing N-efficient maize varieties is necessary. In this research, maize varieties, i.e., the low-N-efficient (Zhengdan 958, ZD958), the high-N efficient (Xianyu 335, XY335), the double-high varieties (Qiule 368, QL368), and the double inefficient-type varieties (Yudan 606 YD606), were used as materials. Results indicate that nitrogen fertilization significantly increased the vegetation indices NDVI, GNDVI, GOSAVI, and RVI of maize varieties with different nitrogen efficiencies. These findings were consistent with the performance of yield, dry matter mass, and leaf nitrogen content and were also found highest under both medium and high nitrogen conditions in the double-high variety QL368. The correlations of dry matter quality, leaf nitrogen content, yield, and vegetation indices (NDVI, GNDVI, RVI, and GOSAVI) at the filling stage of different N-efficient maize varieties were all highly significant and positive. In this relationship, the best effect was found at the filling stages, with correlation coefficients reaching 0.772–0.942, 0.774–0.970, 0754–0.960, and 0.800–0.960. The results showed that the yield, dry matter weight, and leaf nitrogen content of maize varieties with different nitrogen efficiencies increased first and then stabilized with the increase in the nitrogen application level in different periods, and the highest nitrogen application level of maize yield should be between 270 and 360 kg/hm2. At the filling stage, canopy vegetation index of maize varieties with different nitrogen efficiencies was positively correlated with yield, dry matter weight, and leaf nitrogen content, especially GNDVI and GOSAVI on the leaf nitrogen content. It can be used as a means to predict its growth index

    Trafficking-Deficient G572R-hERG and E637K-hERG Activate Stress and Clearance Pathways in Endoplasmic Reticulum

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    Background: Long QT syndrome type 2 (LQT2) is the second most common type of all long QT syndromes. It is well-known that trafficking deficient mutant human ether-a-go-go-related gene (hERG) proteins are often involved in LQT2. Cells respond to misfolded and trafficking-deficient proteins by eliciting the unfolded protein response (UPR) and Activating Transcription Factor (ATF6) has been identified as a key regulator of the mammalian UPR. In this study, we investigated the role of ER chaperone proteins (Calnexin and Calreticulin) in the processing of G572R-hERG and E637K-hERG mutant proteins. Methods: pcDNA3-WT-hERG, pcDNA3-G572R-hERG and pcDNA3-E637K-hERG plasmids were transfected into U2OS and HEK293 cells. Confocal microscopy and western blotting were used to analyze subcellular localization and protein expression. Interaction between WT or mutant hERGs and Calnexin/Calreticulin was tested by coimmunoprecipitation. To assess the role of the ubiquitin proteasome pathway in the degradation of mutant hERG proteins, transfected HEK293 cells were treated with proteasome inhibitors and their effects on the steady state protein levels of WT and mutant hERGs were examined. Conclusion: Our results showed that levels of core-glycosylated immature forms of G572R-hERG and E637K-hERG in association with Calnexin and Calreticulin were higher than that in WT-hERG. Both mutant hERG proteins could activate the UPR by upregulating levels of active ATF6. Furthermore, proteasome inhibition increased the levels of core-glycosylated immature forms of WT and mutant hERGs. In addition, interaction between mutant hERGs and Calnexin/Calreticulin wa

    Adaption of Seasonal H1N1 Influenza Virus in Mice

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    The experimental infection of a mouse lung with influenza A virus has proven to be an invaluable model for studying the mechanisms of viral adaptation and virulence. The mouse adaption of human influenza A virus can result in mutations in the HA and other proteins, which is associated with increased virulence in mouse lungs. In this study, a mouse-adapted seasonal H1N1 virus was obtained through serial lung-to-lung passages and had significantly increased virulence and pathogenicity in mice. Genetic analysis indicated that the increased virulence of the mouse-adapted virus was attributed to incremental acquisition of three mutations in the HA protein (T89I, N125T, and D221G). However, the mouse adaption of influenza A virus did not change the specificity and affinity of receptor binding and the pH-dependent membrane fusion of HA, as well as the in vitro replication in MDCK cells. Notably, infection with the mouse adapted virus induced severe lymphopenia and modulated cytokine and chemokine responses in mice. Apparently, mouse adaption of human influenza A virus may change the ability to replicate in mouse lungs, which induces strong immune responses and inflammation in mice. Therefore, our findings may provide new insights into understanding the mechanisms underlying the mouse adaption and pathogenicity of highly virulent influenza viruses

    Wave-Particle Duality Relation with a Quantum Which-Path Detector

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    According to the relevant theories on duality relation, the summation of the extractable information of a quanton’s wave and particle properties, which are characterized by interference visibility V and path distinguishability D, respectively, is limited. However, this relation is violated upon quantum superposition between the wave-state and particle-state of the quanton, which is caused by the quantum beamsplitter (QBS). Along another line, recent studies have considered quantum coherence C in the l1-norm measure as a candidate for the wave property. In this study, we propose an interferometer with a quantum which-path detector (QWPD) and examine the generalized duality relation based on C. We find that this relationship still holds under such a circumstance, but the interference between these two properties causes the full-particle property to be observed when the QWPD system is partially present. Using a pair of polarization-entangled photons, we experimentally verify our analysis in the two-path case. This study extends the duality relation between coherence and path information to the quantum case and reveals the effect of quantum superposition on the duality relation

    The Single Nucleotide Polymorphism rs1014290 of the SLC2A9 Gene Is Associated with Uric Acid Metabolism in Parkinson’s Disease

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    Individuals with Parkinson’s disease (PD) have lower uric acid levels than those without PD, and the CC genotype and C minor allele of a single nucleotide polymorphism (SNP), rs1014290 of SLC2A9, are associated with lower uric acid levels. We investigated the association of rs1014290 with uric acid metabolism in a cohort of PD cases (220) and controls (110) in a Han Chinese population. Uric acid levels were determined and rs1014290 was assayed using a mutation-sensitive on/off switch technology. PD uric acid levels (291.65 ± 76.29 μmol/L) were significantly lower than the controls (325.73 ± 74.23 μmol/L, P<0.001, t-test). Individuals with rs1014290 TT and CT genotypes had higher uric acid levels, and those with the CC genotype had the lowest uric acid levels among both control and PD cases. The CC genotype and the C minor allele were statistically more frequent in the PD group compared to the control group. Those with the CC genotype had a statistically significant higher risk of PD than those with the TT or TC genotype (odds ratio [OR] = 2.249, 95% confidence interval [CI]: 1.129–4.480, and P=0.021). Thus, SLC2A9 rs1014290 is related to lower uric acid levels in PD patients and can be a risk factor for PD in the Han population

    Using local chromatin structure to improve CRISPR/Cas9 efficiency in zebrafish.

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    Although the CRISPR/Cas9 has been successfully applied in zebrafish, considerable variations in efficiency have been observed for different gRNAs. The workload and cost of zebrafish mutant screening is largely dependent on the mutation rate of injected embryos; therefore, selecting more effective gRNAs is especially important for zebrafish mutant construction. Besides the sequence features, local chromatin structures may have effects on CRISPR/Cas9 efficiency, which remain largely unexplored. In the only related study in zebrafish, nucleosome organization was not found to have an effect on CRISPR/Cas9 efficiency, which is inconsistent with recent studies in vitro and in mammalian cell lines. To understand the effects of local chromatin structure on CRISPR/Cas9 efficiency in zebrafish, we first determined that CRISPR/Cas9 introduced genome editing mainly before the dome stage. Based on this observation, we reanalyzed our published nucleosome organization profiles and generated chromatin accessibility profiles in the 256-cell and dome stages using ATAC-seq technology. Our study demonstrated that chromatin accessibility showed positive correlation with CRISPR/Cas9 efficiency, but we did not observe a clear correlation between nucleosome organization and CRISPR/Cas9 efficiency. We constructed an online database for zebrafish gRNA selection based on local chromatin structure features that could prove beneficial to zebrafish homozygous mutant construction via CRISPR/Cas9
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