3,801 research outputs found

    Quantum circuit for security proof of quantum key distribution without encryption of error syndrome and noisy processing

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    One of the simplest security proofs of quantum key distribution is based on the so-called complementarity scenario, which involves the complementarity control of an actual protocol and a virtual protocol [M. Koashi, e-print arXiv:0704.3661 (2007)]. The existing virtual protocol has a limitation in classical postprocessing, i.e., the syndrome for the error-correction step has to be encrypted. In this paper, we remove this limitation by constructing a quantum circuit for the virtual protocol. Moreover, our circuit with a shield system gives an intuitive proof of why adding noise to the sifted key increases the bit error rate threshold in the general case in which one of the parties does not possess a qubit. Thus, our circuit bridges the simple proof and the use of wider classes of classical postprocessing.Comment: 8 pages, 2 figures. Typo correcte

    Security of quantum key distribution with iterative sifting

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    Several quantum key distribution (QKD) protocols employ iterative sifting. After each quantum transmission round, Alice and Bob disclose part of their setting information (including their basis choices) for the detected signals. The quantum phase of the protocol then ends when the numbers of detected signals per basis exceed certain pre-agreed threshold values. Recently, however, Pfister et al. [New J. Phys. 18 053001 (2016)] showed that iterative sifting makes QKD insecure, especially in the finite key regime, if the parameter estimation for privacy amplification uses the random sampling theory. This implies that a number of existing finite key security proofs could be flawed and cannot guarantee security. Here, we solve this serious problem by showing that the use of Azuma's inequality for parameter estimation makes QKD with iterative sifting secure again. This means that the existing protocols whose security proof employs this inequality remain secure even if they employ iterative sifting. Also, our results highlight a fundamental difference between the random sampling theorem and Azuma's inequality in proving security.Comment: 9 pages. We have found a flaw in the first version, which we have corrected in the revised versio

    Radiolabelling Pt-based quadruplex DNA binders via click chemistry.

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    Guanine-rich sequences of DNA and RNA can fold into intramolecular tetra-helical assemblies known as G-quadruplexes (G4). Their formation in vivo has been associated to a range of biological functions and therefore they have been identified as potential drug targets. Consequently, a broad range of small molecules have been developed to target G4s. Amongst those are metal complexes with Schiff base ligands. Herein, we report the functionalisation of one of these well-established G4 DNA binders (based on a square planar platinum(II)-salphen complex) with two different radiolabelled complexes. An 111In-conjugate was successfully used to assess its in vivo distribution in a mouse tumour model using single-photon emission computed tomography (SPECT) imaging. These studies highlighted the accumulation of this Pt-salphen-111In conjugate in the tumour

    Comparative effects of Apron plus 50DS and soil amendment on the growth, yield and food components of soybean

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    Comparative effects of Apron plus 50DS (a systemic fungicide) and soil amendment (poultry droppings) on growth yield and food components of soybean (TGX 1485-1D) were studied. Soybean seeds treated withrecommended dose of Apron plus 50DS had lower percentage germination when compared to the other treatments while the untreated seeds (control) had the highest percentage germination. Seeds treated with Apron plus and planted on amended soil gave the best performance in terms of development and yield. Biochemical analysis of harvested seeds showed an increase in protein content of seeds treated with recommended dose of Apron plus, planted on amended soil. Seeds treated with less than the recommended dose had the highest percentage carbohydrate content, while untreated seeds planted on amended soil had the lowest carbohydrate content. The control experiment had the highest percentage crude fibre while the lowestwas recorded for seeds treated with recommended dose of Apron plus, planted on amended soil. However, there is no significant difference among the treatments in percentage ash and moisture content

    Quantum key distribution with setting-choice-independently correlated light sources

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    Despite the enormous theoretical and experimental progress made so far in quantum key distribution (QKD), the security of most existing practical QKD systems is not rigorously established yet. A critical obstacle is that almost all existing security proofs make ideal assumptions on the QKD devices. Problematically, such assumptions are hard to satisfy in the experiments, and therefore it is not obvious how to apply such security proofs to practical QKD systems. Fortunately, any imperfections and security-loopholes in the measurement devices can be perfectly closed by measurement-device-independent QKD (MDI-QKD), and thus we only need to consider how to secure the source devices. Among imperfections in the source devices, correlations between the sending pulses and modulation fluctuations are one of the principal problems, which unfortunately most of the existing security proofs do not consider. In this paper, we take into account these imperfections and enhance the implementation security of QKD. Specifically, we consider a setting-choice-independent correlation (SCIC) framework in which the sending pulses can present arbitrary correlations but they are independent of the previous setting choices such as the bit, the basis and the intensity settings. Within the framework of SCIC, we consider the dominant fluctuations of the sending states, such as the relative phases and the intensities, and provide a self-contained information-theoretic security proof for the loss-tolerant QKD protocol in the finite-key regime. We demonstrate the feasibility of secure quantum communication, and thus our work constitutes a crucial step towards guaranteeing the security of practical QKD systems.Grant-in-Aid for JSPS Fellows | Ref. KAKENHI N. JP17J04177MEXT/JSPS | Ref. KAKENHI N. JP18H05237Ministerio de Economía y Competitividad | Ref. TEC2014-54898-RJST-CREST | Ref. JPMJCR167

    Basal Cell Nevus Syndrome Showing Several Histologic Types of Basal Cell Carcinoma

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    Basal cell nevus syndrome (BCNS), or Gorlin Syndrome, is an autosomal dominant disorder, characterized by multiple developmental abnormalities and associated with germline mutations in the PTCH gene. Patients show multiple and early onset basal cell carcinomas (BCCs) in skin, odontogeniccysts in the jaw, pits on palms and soles, medulloblastoma, hypertelorism, and calcification of the falx cerebri. Clinical features of BCCs in these patients are indistinguishable from ordinary BCCs. However, some patients show variable histologic findings in subtypes of BCCs, and only one case associated with several histologic types of BCCs in the syndrome has been reported in Korea. We present a case of BCNS characterized by multiple BCCs, odontogenic keratocysts, multiple palmar pits, and calcified falx cerebri. Histopathologic findings of BCCs showed several patterns, which were nodular, superficial, and pigmented types

    Noninvasive Prenatal Diagnosis of Fetal Trisomy 18 and Trisomy 13 by Maternal Plasma DNA Sequencing

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    Massively parallel sequencing of DNA molecules in the plasma of pregnant women has been shown to allow accurate and noninvasive prenatal detection of fetal trisomy 21. However, whether the sequencing approach is as accurate for the noninvasive prenatal diagnosis of trisomy 13 and 18 is unclear due to the lack of data from a large sample set. We studied 392 pregnancies, among which 25 involved a trisomy 13 fetus and 37 involved a trisomy 18 fetus, by massively parallel sequencing. By using our previously reported standard z-score approach, we demonstrated that this approach could identify 36.0% and 73.0% of trisomy 13 and 18 at specificities of 92.4% and 97.2%, respectively. We aimed to improve the detection of trisomy 13 and 18 by using a non-repeat-masked reference human genome instead of a repeat-masked one to increase the number of aligned sequence reads for each sample. We then applied a bioinformatics approach to correct GC content bias in the sequencing data. With these measures, we detected all (25 out of 25) trisomy 13 fetuses at a specificity of 98.9% (261 out of 264 non-trisomy 13 cases), and 91.9% (34 out of 37) of the trisomy 18 fetuses at 98.0% specificity (247 out of 252 non-trisomy 18 cases). These data indicate that with appropriate bioinformatics analysis, noninvasive prenatal diagnosis of trisomy 13 and trisomy 18 by maternal plasma DNA sequencing is achievable

    Non-invasive prenatal assessment of trisomy 21 by multiplexed maternal plasma DNA sequencing: large scale validity study.

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    To validate the clinical efficacy and practical feasibility of massively parallel maternal plasma DNA sequencing to screen for fetal trisomy 21 among high risk pregnancies clinically indicated for amniocentesis or chorionic villus sampling. Diagnostic accuracy validated against full karyotyping, using prospectively collected or archived maternal plasma samples. Prenatal diagnostic units in Hong Kong, United Kingdom, and the Netherlands. 753 pregnant women at high risk for fetal trisomy 21 who underwent definitive diagnosis by full karyotyping, of whom 86 had a fetus with trisomy 21. Intervention Multiplexed massively parallel sequencing of DNA molecules in maternal plasma according to two protocols with different levels of sample throughput: 2-plex and 8-plex sequencing. Proportion of DNA molecules that originated from chromosome 21. A trisomy 21 fetus was diagnosed when the z score for the proportion of chromosome 21 DNA molecules was >3. Diagnostic sensitivity, specificity, positive predictive value, and negative predictive value were calculated for trisomy 21 detection. Results were available from 753 pregnancies with the 8-plex sequencing protocol and from 314 pregnancies with the 2-plex protocol. The performance of the 2-plex protocol was superior to that of the 8-plex protocol. With the 2-plex protocol, trisomy 21 fetuses were detected at 100% sensitivity and 97.9% specificity, which resulted in a positive predictive value of 96.6% and negative predictive value of 100%. The 8-plex protocol detected 79.1% of the trisomy 21 fetuses and 98.9% specificity, giving a positive predictive value of 91.9% and negative predictive value of 96.9%. Multiplexed maternal plasma DNA sequencing analysis could be used to rule out fetal trisomy 21 among high risk pregnancies. If referrals for amniocentesis or chorionic villus sampling were based on the sequencing test results, about 98% of the invasive diagnostic procedures could be avoided.published_or_final_versio

    Technology-assisted stroke rehabilitation in Mexico: a pilot randomized trial comparing traditional therapy to circuit training in a Robot/technology-assisted therapy gym

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    Background Stroke rehabilitation in low- and middle-income countries, such as Mexico, is often hampered by lack of clinical resources and funding. To provide a cost-effective solution for comprehensive post-stroke rehabilitation that can alleviate the need for one-on-one physical or occupational therapy, in lower and upper extremities, we proposed and implemented a technology-assisted rehabilitation gymnasium in Chihuahua, Mexico. The Gymnasium for Robotic Rehabilitation (Robot Gym) consisted of low- and high-tech systems for upper and lower limb rehabilitation. Our hypothesis is that the Robot Gym can provide a cost- and labor-efficient alternative for post-stroke rehabilitation, while being more or as effective as traditional physical and occupational therapy approaches. Methods A typical group of stroke patients was randomly allocated to an intervention (n = 10) or a control group (n = 10). The intervention group received rehabilitation using the devices in the Robot Gym, whereas the control group (n = 10) received time-matched standard care. All of the study subjects were subjected to 24 two-hour therapy sessions over a period of 6 to 8 weeks. Several clinical assessments tests for upper and lower extremities were used to evaluate motor function pre- and post-intervention. A cost analysis was done to compare the cost effectiveness for both therapies. Results No significant differences were observed when comparing the results of the pre-intervention Mini-mental, Brunnstrom Test, and Geriatric Depression Scale Test, showing that both groups were functionally similar prior to the intervention. Although, both training groups were functionally equivalent, they had a significant age difference. The results of all of the upper extremity tests showed an improvement in function in both groups with no statistically significant differences between the groups. The Fugl-Meyer and the 10 Meters Walk lower extremity tests showed greater improvement in the intervention group compared to the control group. On the Time Up and Go Test, no statistically significant differences were observed pre- and post-intervention when comparing the control and the intervention groups. For the 6 Minute Walk Test, both groups presented a statistically significant difference pre- and post-intervention, showing progress in their performance. The robot gym therapy was more cost-effective than the traditional one-to-one therapy used during this study in that it enabled therapist to train up to 1.5 to 6 times more patients for the approximately same cost in the long term. Conclusions The results of this study showed that the patients that received therapy using the Robot Gym had enhanced functionality in the upper extremity tests similar to patients in the control group. In the lower extremity tests, the intervention patients showed more improvement than those subjected to traditional therapy. These results support that the Robot Gym can be as effective as traditional therapy for stroke patients, presenting a more cost- and labor-efficient option for countries with scarce clinical resources and funding. Trial registration ISRCTN98578807
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