121 research outputs found

    Determination of the mimic epitope of the M-like protein adhesin in swine Streptococcus equi subsp. zooepidemicus

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    <p>Abstract</p> <p>Background</p> <p>The M-like protein, also known as SzP, is expressed on the surface of <it>Streptococcus equi </it>subsp. z<it>ooepidemicus </it>(<it>S</it>. z<it>ooepidemicus</it>). Previous studies demonstrated that SzP is similar to M protein of group A <it>Streptococcus </it>in the structure and characteristics of antiphagocytosis. The M protein is an adhesin that can bind to the host cells, however it is not known whether the SzP of <it>S</it>. z<it>ooepidemicus </it>also functions as an adhesin. We conducted an investigation to determine SzP as an adhesin, and one SzP epitope was identified to be responsible for mediating binding to HEp-2 cells.</p> <p>Methods</p> <p>The gene encoding SzP was expressed in <it>E. coli</it>, and the purified recombinant SzP (rSzP) was recognized by rabbit anti-<it>S</it>. z<it>ooepidemicus </it>antibodies using immunoblot. Furthermore, the adherence of <it>S</it>. z<it>ooepidemicus </it>to HEp-2 cells was inhibited by anti-rSzP antibodies in a dose-dependent manner. We employed a random 12-peptide phage display library for screening of immunodominant mimics of the SzP, which were recognized by an anti-SzP specific monoclonal antibody (mAb 2C8). Initial positive phage clones were identified by ELISA, followed by assays to determine the adherence-inhibiting ability of the peptide.</p> <p>Results</p> <p>Ten out of fourteen selected positive clones showed high reactivity that effectively inhibited the binding of mAb 2C8 to rSzP. The motif XSLSRX was highly conserved among six of the ten clones.</p> <p>Conclusion</p> <p>Collectively, our findings suggest that the motif XSLSRX may represent an immunodominant mimic epitope of the SzP of <it>S</it>. z<it>ooepidemicus </it>strain ATCC 35246, and that the same epitope may be used to mediate SzP binding to HEp-2 cells.</p

    MR imaging of intracranial solitary fibrous tumor: a retrospective study of 7 cases

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    Objective: To investigate the MR imaging diagnostic features of intracranial solitary fibrous tumors (ISFTs).Materials and methods: Seven patients (mean age of 52.9 years; M:F=3:4) with histopathologically proven ISFTs were identified at our institute. Clinical presentations and pathological features were reviewed. MR Imaging findings including signal intensity, gadopentetate dimeglumine enhanced pattern, and diffusion-weighted imaging (DWI) characterization of the tumors were retrospectively evaluated.Results: Six tumors showed a multi-lobular contour. Five tumors showed heterogeneous signal intensity, and two tumors showed homogeneous signal intensity on T1WI. Low signal intensity linear, curved or interlacing lines were observed within the tumors in all seven cases. Seven tumors demonstrated moderate or strong enhancement, six showed heterogeneous enhancement, and one homogenous enhancement. All tumors showed heterogeneous signal intensity on DWI.A ring–like high signal intensity band distributed around within the tumor was noted in six cases on DWI.Conclusion: Diagnostic evidence for ISFT on MR image includes heterogeneous signal intensity, intense enhancement of T2 signal intensity, low signal intensity lines within the tumor, heterogeneous signal intensity on DWI and a ring-like band around the tumor on DWI.Keywords: Intracranial Solitary Fibrous Tumor, Magnetic resonance imaging, Diffusion-weighted Imaging

    MR imaging of intracranial solitary fibrous tumor: a retrospective study of 7 cases

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    Objective: To investigate the MR imaging diagnostic features of intracranial solitary fibrous tumors (ISFTs). Materials and methods: Seven patients (mean age of 52.9 years; M:F=3:4) with histopathologically proven ISFTs were identified at our institute. Clinical presentations and pathological features were reviewed. MR Imaging findings including signal intensity, gadopentetate dimeglumine enhanced pattern, and diffusion-weighted imaging (DWI) characterization of the tumors were retrospectively evaluated. Results: Six tumors showed a multi-lobular contour. Five tumors showed heterogeneous signal intensity, and two tumors showed homogeneous signal intensity on T1WI. Low signal intensity linear, curved or interlacing lines were observed within the tumors in all seven cases. Seven tumors demonstrated moderate or strong enhancement, six showed heterogeneous enhancement, and one homogenous enhancement. All tumors showed heterogeneous signal intensity on DWI.A ring\u2013like high signal intensity band distributed around within the tumor was noted in six cases on DWI. Conclusion: Diagnostic evidence for ISFT on MR image includes heterogeneous signal intensity, intense enhancement of T2 signal intensity, low signal intensity lines within the tumor, heterogeneous signal intensity on DWI and a ring-like band around the tumor on DWI

    PAN: Pulse Ansatz on NISQ Machines

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    Variational quantum algorithms (VQAs) have demonstrated great potentials in the NISQ era. In the workflow of VQA, the parameters of ansatz are iteratively updated to approximate the desired quantum states. We have seen various efforts to draft better ansatz with less gates. In quantum computers, the gate ansatz will eventually be transformed into control signals such as microwave pulses on transmons. And the control pulses need elaborate calibration to minimize the errors such as over-rotation and under-rotation. In the case of VQAs, this procedure will introduce redundancy, but the variational properties of VQAs can naturally handle problems of over-rotation and under-rotation by updating the amplitude and frequency parameters. Therefore, we propose PAN, a native-pulse ansatz generator framework for VQAs. We generate native-pulse ansatz with trainable parameters for amplitudes and frequencies. In our proposed PAN, we are tuning parametric pulses, which are natively supported on NISQ computers. Considering that parameter-shift rules do not hold for native-pulse ansatz, we need to deploy non-gradient optimizers. To constrain the number of parameters sent to the optimizer, we adopt a progressive way to generate our native-pulse ansatz. Experiments are conducted on both simulators and quantum devices to validate our methods. When adopted on NISQ machines, PAN obtained improved the performance with decreased latency by an average of 86%. PAN is able to achieve 99.336% and 96.482% accuracy for VQE tasks on H2 and HeH+ respectively, even with considerable noises in NISQ machines.Comment: 13 pages, 13 figure

    Towards Advantages of Parameterized Quantum Pulses

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    The advantages of quantum pulses over quantum gates have attracted increasing attention from researchers. Quantum pulses offer benefits such as flexibility, high fidelity, scalability, and real-time tuning. However, while there are established workflows and processes to evaluate the performance of quantum gates, there has been limited research on profiling parameterized pulses and providing guidance for pulse circuit design. To address this gap, our study proposes a set of design spaces for parameterized pulses, evaluating these pulses based on metrics such as expressivity, entanglement capability, and effective parameter dimension. Using these design spaces, we demonstrate the advantages of parameterized pulses over gate circuits in the aspect of duration and performance at the same time thus enabling high-performance quantum computing. Our proposed design space for parameterized pulse circuits has shown promising results in quantum chemistry benchmarks.Comment: 11 Figures, 4 Table

    RobustState: Boosting Fidelity of Quantum State Preparation via Noise-Aware Variational Training

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    Quantum state preparation, a crucial subroutine in quantum computing, involves generating a target quantum state from initialized qubits. Arbitrary state preparation algorithms can be broadly categorized into arithmetic decomposition (AD) and variational quantum state preparation (VQSP). AD employs a predefined procedure to decompose the target state into a series of gates, whereas VQSP iteratively tunes ansatz parameters to approximate target state. VQSP is particularly apt for Noisy-Intermediate Scale Quantum (NISQ) machines due to its shorter circuits. However, achieving noise-robust parameter optimization still remains challenging. We present RobustState, a novel VQSP training methodology that combines high robustness with high training efficiency. The core idea involves utilizing measurement outcomes from real machines to perform back-propagation through classical simulators, thus incorporating real quantum noise into gradient calculations. RobustState serves as a versatile, plug-and-play technique applicable for training parameters from scratch or fine-tuning existing parameters to enhance fidelity on target machines. It is adaptable to various ansatzes at both gate and pulse levels and can even benefit other variational algorithms, such as variational unitary synthesis. Comprehensive evaluation of RobustState on state preparation tasks for 4 distinct quantum algorithms using 10 real quantum machines demonstrates a coherent error reduction of up to 7.1 ×\times and state fidelity improvement of up to 96\% and 81\% for 4-Q and 5-Q states, respectively. On average, RobustState improves fidelity by 50\% and 72\% for 4-Q and 5-Q states compared to baseline approaches.Comment: Accepted to FASTML @ ICCAD 2023. 14 pages, 20 figure

    The Effect of Treadmill Training Pre-Exercise on Glutamate Receptor Expression in Rats after Cerebral Ischemia

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    Physical exercise has been demonstrated to be neuroprotective in both clinical and laboratory settings. However, the exact mechanism underlying this effect is unclear. Our study aimed to investigate whether pre-ischemic treadmill training could serve as a form of ischemic preconditioning in a rat model undergoing middle cerebral artery occlusion (MCAO). Thirty-six rats were divided into three groups: a sham control group, a non-exercise with operation group and an exercise with operation group. After treadmill training, ischemia was induced by occluding the MCA for 2 h, followed by reperfusion. Half of the rats in each group were sacrificed for mRNA detection of mGluR5 and NR2B 80 min after occlusion. The remaining animals were evaluated for neurological deficits by behavioral scoring and then decapitated to assess the infarct volume. The mRNA expression of mGluR5 and NR2B was detected by real-time PCR. The results suggest that pre-ischemic treadmill training may induce brain ischemic tolerance by reducing the mRNA levels of mGluR5 and NR2B, and thus, the results indicate that physical exercise might be an effective method to establish ischemic preconditioning

    Biocompatible Single-Crystal Selenium Nanobelt Based Nanodevice as a Temperature-Tunable Photosensor

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    Selenium materials are widely used in photoelectrical devices, owing to their unique semiconductive properties. Single-crystal selenium nanobelts with large specific surface area, fine photoconductivity, and biocompatibility provide potential applications in biomedical nanodevices, such as implantable artificial retina and rapid photon detector/stimulator for optogenetics. Here, we present a selenium nanobelt based nanodevice, which is fabricated with single Se nanobelt. This device shows a rapid photo response, different sensitivities to visible light of variable wave length, and temperature-tunable property. The biocompatibility of the Se nanobelts was proved by MTT test using two cell lines. Our investigation introduced a photosensor that will be important for multiple potential applications in human visual system, photocells in energy or MEMS, and temperature-tunable photoelectrical device for optogenetics research
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