106 research outputs found

    CS-SELEX Generates High-Affinity ssDNA Aptamers as Molecular Probes for Hepatitis C Virus Envelope Glycoprotein E2

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    Currently, the development of effective diagnostic reagents as well as treatments against Hepatitis C virus (HCV) remains a high priority. In this study, we have described the development of an alive cell surface -Systematic Evolution of Ligands by Exponential Enrichment (CS-SELEX) technique and screened the functional ssDNA aptamers that specifically bound to HCV envelope surface glycoprotein E2. Through 13 rounds of selection, the CS-SELEX generated high-affinity ssDNA aptamers, and the selected ssDNA aptamer ZE2 demonstrated the highest specificity and affinity to E2-positive cells. HCV particles could be specifically captured and diagnosed using the aptamer ZE2. A good correlation was observed in HCV patients between HCV E2 antigen-aptamer assay and assays for HCV RNA quantities or HCV antibody detection. Moreover, the selected aptamers, especially ZE2, could competitively inhibit E2 protein binding to CD81, an important HCV receptor, and significantly block HCV cell culture (HCVcc) infection of human hepatocytes (Huh7.5.1) in vitro. Our data demonstrate that the newly selected ssDNA aptamers, especially aptamer ZE2, hold great promise for developing new molecular probes, as an early diagnostic reagent for HCV surface antigen, or a therapeutic drug specifically for HCV

    Giant photoinduced lattice distortion in oxygen-vacancy ordered SrCoO2.5 thin films

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    Despite of the tremendous efforts spent on the oxygen vacancy migration in determining the property optimization of oxygen-vacancy enrichment transition metal oxides, few has focused on their dynamic behaviors non-equilibrium states. In this work, we performed multi-timescale ultrafast X-ray diffraction measurements by using picosecond synchrotron X-ray pulses and femtosecond table-top X-ray pulses to monitor the structural dynamics in the oxygen-vacancy ordered SrCoO2.5 thin films. A giant photoinduced strain ({\Delta}c/c > 1%) was observed, whose distinct correlation with the pump photon energy indicates a non-thermal origin of the photoinduced strain. The sub-picosecond resolution X-ray diffraction reveals the formation and propagation of the coherent acoustic phonons inside the film. We also simulate the effect of photoexcited electron-hole pairs and the resulting lattice changes using the Density Function Theory method to obtain further insight on the microscopic mechanism of the measured photostriction effect. Comparable photostrictive responses and the strong dependence on excitation wavelength are predicted, revealing a bonding to anti-bonding charge transfer or high spin to intermediate spin crossover induced lattice expansion in the oxygen-vacancy films.Comment: 12 pages, 4 figures, support materia

    Continuous Femoral Nerve Block versus Intravenous Patient Controlled Analgesia for Knee Mobility and Long-Term Pain in Patients Receiving Total Knee Replacement: A Randomized Controlled Trial

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    Objectives. To evaluate the comparative analgesia effectiveness and safety of postoperative continuous femoral nerve block (CFNB) with patient controlled intravenous analgesia (PCIA) and their impact on knee function and chronic postoperative pain. Methods. Participants were randomly allocated to receive postoperative continuous femoral nerve block (group CFNB) or intravenous patient controlled analgesia (group PCIA). Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores for knee and incidence of chronic postoperative pain at 3, 6, and 12 months postoperatively were compared. postoperative pain and salvage medication at rest or during mobilization 24 hours, 48 hours, and 7 days postoperatively were also recorded. Results. After discharge from the hospital and rehabilitation of joint function, patients in group CFNB reported significantly improved knee flexion and less incidence of chronic postoperative pain at 3 months and 6 months postoperatively (P<0.05). Analgesic rescue medications were significantly reduced in patients receiving CFNB (P<0.001 and P=0.031, resp.). Conclusion. With standardized rehabilitation therapy, continuous femoral nerve block analgesia reduced the incidence of chronic postoperative pain, improved motility of replaced joints, and reduced the dosages of rescue analgesic medications, suggesting a recovery-enhancing effect of peripheral nerve block analgesia

    Picosecond electric-field-induced threshold switching in phase-change materials

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    Many chalcogenide glasses undergo a breakdown in electronic resistance above a critical field strength. Known as threshold switching, this mechanism enables field-induced crystallization in emerging phase-change memory. Purely electronic as well as crystal nucleation assisted models have been employed to explain the electronic breakdown. Here, picosecond electric pulses are used to excite amorphous Ag4_4In3_3Sb67_{67}Te26_{26}. Field-dependent reversible changes in conductivity and pulse-driven crystallization are observed. The present results show that threshold switching can take place within the electric pulse on sub-picosecond time-scales - faster than crystals can nucleate. This supports purely electronic models of threshold switching and reveals potential applications as an ultrafast electronic switch.Comment: 6 pages manuscript with 3 figures and 8 pages supplementary materia

    Continuous Femoral Nerve Block versus Intravenous Patient Controlled Analgesia for Knee Mobility and Long-Term Pain in Patients Receiving Total Knee Replacement: A Randomized Controlled Trial

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    Objectives. To evaluate the comparative analgesia effectiveness and safety of postoperative continuous femoral nerve block (CFNB) with patient controlled intravenous analgesia (PCIA) and their impact on knee function and chronic postoperative pain. Methods. Participants were randomly allocated to receive postoperative continuous femoral nerve block (group CFNB) or intravenous patient controlled analgesia (group PCIA). Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores for knee and incidence of chronic postoperative pain at 3, 6, and 12 months postoperatively were compared. postoperative pain and salvage medication at rest or during mobilization 24 hours, 48 hours, and 7 days postoperatively were also recorded. Results. After discharge from the hospital and rehabilitation of joint function, patients in group CFNB reported significantly improved knee flexion and less incidence of chronic postoperative pain at 3 months and 6 months postoperatively ( &lt; 0.05). Analgesic rescue medications were significantly reduced in patients receiving CFNB ( &lt; 0.001 and = 0.031, resp.). Conclusion. With standardized rehabilitation therapy, continuous femoral nerve block analgesia reduced the incidence of chronic postoperative pain, improved motility of replaced joints, and reduced the dosages of rescue analgesic medications, suggesting a recovery-enhancing effect of peripheral nerve block analgesia
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