213 research outputs found

    Molecular Structural Differences between Type-2-Diabetic and Healthy Glycogen

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    Glycogen is a highly branched glucose polymer functioning as a glucose buffer in animals. Multiple-detector size exclusion chromatography and fluorophore-assisted carbohydrate electrophoresis were used to examine the structure of undegraded native liver glycogen (both whole and enzymatically debranched) as a function of molecular size, isolated from the livers of healthy and db/db mice (the latter a type 2 diabetic model). Both the fully branched and debranched levels of glycogen structure showed fundamental differences between glycogen from healthy and db/db mice. Healthy glycogen had a greater population of large particles, with more α particles (tightly linked assemblages of smaller β particles) than glycogen from db/db mice. These structural differences suggest a new understanding of type 2 diabetes

    Gaussian Boson Sampling with Pseudo-Photon-Number Resolving Detectors and Quantum Computational Advantage

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    We report new Gaussian boson sampling experiments with pseudo-photon-number-resolving detection, which register up to 255 photon-click events. We consider partial photon distinguishability and develop a more complete model for characterization of the noisy Gaussian boson sampling. In the quantum computational advantage regime, we use Bayesian tests and correlation function analysis to validate the samples against all current classical mockups. Estimating with the best classical algorithms to date, generating a single ideal sample from the same distribution on the supercomputer Frontier would take ~ 600 years using exact methods, whereas our quantum computer, Jiuzhang 3.0, takes only 1.27 us to produce a sample. Generating the hardest sample from the experiment using an exact algorithm would take Frontier ~ 3.1*10^10 years.Comment: submitted on 10 Apri

    Gaussian Boson Sampling with Pseudo-Photon-Number-Resolving Detectors and Quantum Computational Advantage

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    We report new Gaussian boson sampling experiments with pseudo-photon-number-resolving detection, which register up to 255 photon-click events. We consider partial photon distinguishability and develop a more complete model for the characterization of the noisy Gaussian boson sampling. In the quantum computational advantage regime, we use Bayesian tests and correlation function analysis to validate the samples against all current classical spoofing mockups. Estimating with the best classical algorithms to date, generating a single ideal sample from the same distribution on the supercomputer Frontier would take ∼600 yr using exact methods, whereas our quantum computer, Jizhāng 3.0, takes only 1.27 μs to produce a sample. Generating the hardest sample from the experiment using an exact algorithm would take Frontier∼3.1×1010 yr.</p

    SnO2Nanowire Arrays and Electrical Properties Synthesized by Fast Heating a Mixture of SnO2and CNTs Waste Soot

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    SnO2nanowire arrays were synthesized by fast heating a mixture of SnO2and the carbon nanotubes waste soot by high-frequency induction heating. The resultant SnO2nanowires possess diameters from 50 to 100 nm and lengths up to tens of mircrometers. The field-effect transistors based on single SnO2nanowire exhibit that as-synthesized nanowires have better transistor performance in terms of transconductance and on/off ratio. This work demonstrates a simple technique to the growth of nanomaterials for application in future nanoelectronic devices

    NOXA-Induced Alterations in the Bax/Smac Axis Enhance Sensitivity of Ovarian Cancer Cells to Cisplatin

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    Ovarian cancer is the most common cause of death from gynecologic malignancy. Deregulation of p53 and/or p73-associated apoptotic pathways contribute to the platinum-based resistance in ovarian cancer. NOXA, a pro-apoptotic BH3-only protein, is identified as a transcription target of p53 and/or p73. In this study, we found that genetic variants of Bcl-2 proteins exist among cisplatin-sensitive and -resistant ovarian cancer cells, and the responses of NOXA and Bax to cisplatin are regulated mainly by p53. We further evaluated the effect of NOXA on cisplatin. NOXA induced apoptosis and sensitized A2780s and SKOV3 cells to cisplatin in vitro and in vivo. The effects were mediated by elevated Bax expression, enhanced caspase activation, release of Cyt C and Smac into the cytosol. Furthermore, gene silencing of Bax or Smac significantly attenuated NOXA and/or cisplatin-induced apoptosis in chemosensitive A2780s cells, whereas overexpression of Bax or addition of Smac-N7 peptide significantly increased NOXA and/or cisplatin-induced apoptosis in chemoresistant SKOV3 cells. To our knowledge, these data suggest a new mechanism by which NOXA chemosensitized ovarian cancer cells to cisplatin by inducing alterations in the Bax/Smac axis. Taken together, our findings show that NOXA is potentially useful as a chemosensitizer in ovarian cancer therapy

    Hamiltonicity below Dirac's condition

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    Dirac's theorem (1952) is a classical result of graph theory, stating that an nn-vertex graph (n3n \geq 3) is Hamiltonian if every vertex has degree at least n/2n/2. Both the value n/2n/2 and the requirement for every vertex to have high degree are necessary for the theorem to hold. In this work we give efficient algorithms for determining Hamiltonicity when either of the two conditions are relaxed. More precisely, we show that the Hamiltonian cycle problem can be solved in time cknO(1)c^k \cdot n^{O(1)}, for some fixed constant cc, if at least nkn-k vertices have degree at least n/2n/2, or if all vertices have degree at least n/2kn/2-k. The running time is, in both cases, asymptotically optimal, under the exponential-time hypothesis (ETH). The results extend the range of tractability of the Hamiltonian cycle problem, showing that it is fixed-parameter tractable when parameterized below a natural bound. In addition, for the first parameterization we show that a kernel with O(k)O(k) vertices can be found in polynomial time

    The major causes and risk factors of total and cause-specific mortality during 5.4-year follow-up: the Shanghai Changfeng Study

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    To investigate the major causes and predictive factors of death in a middle-aged and elderly Chinese population. A total of 6591 residents aged ≥ 45 years from Shanghai Changfeng community were followed up for an average of 5.4 years. The causes of death were coded according to the 10th Revision of International Classification of Diseases. The mortality rate was calculated by person-years of follow up and age-standardized according to the 2010 Chinese census data. Multivariable-adjusted Cox proportional hazards model was performed to investigate the predictors of all-cause and cause-specific mortality. During the total follow-up of 35,739 person-years, 370 deaths were documented (157 from malignant neoplasms, 70 from heart diseases, 68 from cerebrovascular diseases, 75 from other causes). The age-standardized all-cause mortality rate was 798.2 per 100,000 person-years (927.9 among men and 716.7 among women). Results from multivariable analyses showed that aging, diabetes, and osteoporosis at baseline were independent predictors of all-cause mortality, with hazard ratios (HR) of 1.11 (95% CI 1.10–1.13), 1.91 (1.51–2.42), and 1.71 (1.24–2.35), respectively. The population attributable risk percent of diabetes and osteoporosis was 19.7% and 11.7%, respectively. Cigarette smoking was associated with a higher risk of all-cause mortality in men (HR and 95%CI 1.44, 1.01–2.06). In women, diabetes and osteoporosis were related to a higher risk of cardiovascular mortality (3.27, 1.82–5.88 and 1.89, 1.04–3.46, respectively). While in men, osteoporosis was related to a higher risk of malignant neoplasms mortality (2.39, 1.07–5.33). Malignant neoplasms, heart diseases, and cerebrovascular diseases are the leading causes of death. Aging, smoking, underweight, diabetes, and osteoporosis are independent predictors of premature death among middle-aged and elderly Chinese community population. Moreover, there may have been some differences in the causes and predictors of premature death between men and women

    Mimotopes selected with neutralizing antibodies against multiple subtypes of influenza A

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    <p>Abstract</p> <p>Background</p> <p>The mimotopes of viruses are considered as the good targets for vaccine design. We prepared mimotopes against multiple subtypes of influenza A and evaluate their immune responses in flu virus challenged Balb/c mice.</p> <p>Methods</p> <p>The mimotopes of influenza A including pandemic H1N1, H3N2, H2N2 and H1N1 swine-origin influenza virus were screened by peptide phage display libraries, respectively. These mimotopes were engineered in one protein as multi- epitopes in Escherichia coli (E. coli) and purified. Balb/c mice were immunized using the multi-mimotopes protein and specific antibody responses were analyzed using hemagglutination inhibition (HI) assay and enzyme-linked immunosorbent assay (ELISA). The lung inflammation level was evaluated by hematoxylin and eosin (HE).</p> <p>Results</p> <p>Linear heptopeptide and dodecapeptide mimotopes were obtained for these influenza virus. The recombinant multi-mimotopes protein was a 73 kDa fusion protein. Comparing immunized infected groups with unimmunized infected subsets, significant differences were observed in the body weight loss and survival rate. The antiserum contained higher HI Ab titer against H1N1 virus and the lung inflammation level were significantly decreased in immunized infected groups.</p> <p>Conclusions</p> <p>Phage-displayed mimotopes against multiple subtypes of influenza A were accessible to the mouse immune system and triggered a humoral response to above virus.</p

    Therapeutic potential of transplanted placental mesenchymal stem cells in treating Chinese miniature pigs with acute liver failure

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    <p>Abstract</p> <p>Background</p> <p>Stem cell-based therapy to treat liver diseases is a focus of current research worldwide. So far, most such studies depend on rodent hepatic failure models. The purpose of this study was to isolate mesenchymal stem cells from human placenta (hPMSCs) and determine their therapeutic potential for treating Chinese experimental miniature pigs with acute liver failure (ALF).</p> <p>Methods</p> <p>hPMSCs were isolated and analyzed for their purity and differentiation potential before being employed as the donor cells for transplantation. ALF models of Chinese experimental miniature pigs were established and divided into four groups: no cell transplantation; hPMSCs transplantation via the jugular vein; X-ray-treated hPMSCs transplantation via the portal vein; and hPMSCs transplantation via the portal vein. The restoration of biological functions of the livers receiving transplantation was assessed via a variety of approaches such as mortality rate determination, serum biochemical analysis, and histological, immunohistochemical, and genetic analysis.</p> <p>Results</p> <p>hPMSCs expressed high levels of CD29, CD73, CD13, and CD90, had adipogenic, osteogenic, and hepatic differentiation potential. They improved liver functions <it>in vivo </it>after transplantation into the D-galactosamine-injured pig livers as evidenced by the fact that ALT, AST, ALP, CHE, TBIL, and TBA concentrations returned to normal levels in recipient ALF pigs. Meanwhile, histological data revealed that transplantation of hPMSCs via the portal vein reduced liver inflammation, decreased hepatic denaturation and necrosis, and promoted liver regeneration. These ameliorations were not found in the other three groups. The result of 7-day survival rates suggested that hPMSCs transplantation via the portal vein was able to significantly prolong the survival of ALF pigs compared with the other three groups. Histochemistry and RT-PCR results confirmed the presence of transplanted human cells in recipient pig livers (Groups III, IV).</p> <p>Conclusions</p> <p>Our data revealed that hPMSCs could not only differentiate into hepatocyte-like cells <it>in vitro </it>and <it>in vivo</it>, but could also prolong the survival time of ALF pigs. Regarding the transplantation pathways, the left branch of the portal vein inside the liver was superior to the jugular vein pathway. Thus, hPMSCs transplantation through the portal vein by B-ultrasonography may represent a superior approach for treating liver diseases.</p
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