348 research outputs found

    Activating mechanism of transcriptor NF-kappaB regulated by hepatitis B virus X protein in hepatocellular carcinoma

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    Aim: To investigate the mechanism and significance of NF-κB activation regulated by hepatitis B virus X protein (HBx) in hepatitis B virus (HBV)-associated hepatocellular carcinoma (HCC). Methods: The expression levels of HBx, p65, IκB-α and ubiquitin were detected by immunohistochemistry in HCC tissue microarrays (TMA) respectively, and IκB-α was detected by Western blot in HCC and corresponding liver tissues. Results: The percentage of informative TMA samples was 98.8% in 186 cases with a total of 367 samples. Compared with corresponding liver tissues (60.0%), the HBx expression was obviously decreased in HBV-associated HCC (47.9%, u=2.24, P<0.05). On the contrary, the expressions of p65 (20.6% vs 45.3%, u=4.85, P<0.01) and ubiquitin (8.9% vs 59.0%, u=9.68, P<0.01 ) were notably elevated in HCC. In addition, IκB-α had a tendency to go up. Importantly, positive relativity was observed between HBx and p65 (χ2=10.26, P<0.01), p65 and IκB-α (χ2=16.86, P<0.01), IκB-α and ubiquitin (χ2=8.90, P<0.01) in HCC, respectively. Conclusion: Both active and non-active forms of NF-κB are increased in HBV-associated HCC. Variant HBx is the major cause of the enhancement of NF-κB activity. The activation always proceeds in nucleus and the proteasome complexes play an important role in the activation.published_or_final_versio

    Simultaneous determination of flavonoids and triterpenoids in Cyclocarya paliurus leaves using high-performance liquid chromatography

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    Background: Cyclocarya paliurus is an endangered plant and endemic to China. The leaves of C. paliurus have been used in drug formulations and as ingredients in functional foods in China. The aim of this study was to develop an effective method to extract most of the compounds and to establish a simplified HPLC analytical method to determine the contents of major bioactive compounds simultaneously.Materials and methods: High-performance liquid chromatography (HPLC) coupled with a photodiode array detector (PDA) was used for the simultaneous determination of the major flavonoids and triterpenoids in C. paliurus leaves.Results: Ultrasonic extraction in 100% methanol for 30 min was adopted as the optimal extraction method for C. paliurus leaves. The separation conditions were optimized using a Phenomenex C18 ODS column (250 mm × 4.6 mm, 5 μm) with a mobile phase of acetonitrile and 0.02% formic acid and a detection wavelength of 205 nm. The validation data indicated that this new HPLC analytical method successfully quantified the provenance and seasonal variations of seven major compounds (three flavonoids and four triterpenoids) in C. paliurus leaves.Conclusion: The study provided a novel and simplified approach to simultaneously determine the quantity of major flavonoids and triterpenoids in C. paliurus leaves. The results could promote the optimization of silvicultural systems for quality control of C. paliurus.Key words: Cyclocarya paliurus; HPLC; flavonoids; triterpenoid

    Proof-of-principle experimental realization of a qubit-like qudit-based quantum key distribution scheme

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    In comparison to qubit-based protocols, qudit-based quantum key distribution ones generally allow two cooperative parties to share unconditionally secure keys under a higher channel noise. However, it is very hard to prepare and measure the required quantum states in qudit-based protocols in general. One exception is the recently proposed highly error tolerant qudit-based protocol known as the Chau15 (Chau 2015 Phys. Rev. A 92 062324). Remarkably, the state preparation and measurement in this protocol can be done relatively easily since the required states are phase encoded almost like the diagonal basis states of a qubit. Here we report the first proof-of-principle demonstration of the Chau15 protocol. One highlight of our experiment is that its post-processing is based on practical one-way manner, while the original proposal in Chau (2015 Phys. Rev. A 92 062324) relies on complicated two-way post-processing, which is a great challenge in experiment. In addition, by manipulating time-bin qudit and measurement with a variable delay interferometer, our realization is extensible to qudit with high-dimensionality and confirms the experimental feasibility of the Chau15 protocol.published_or_final_versio

    A pivotal role for starch in the reconfiguration of 14C-partitioning and allocation in Arabidopsis thaliana under short-term abiotic stress.

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    Plant carbon status is optimized for normal growth but is affected by abiotic stress. Here, we used 14C-labeling to provide the first holistic picture of carbon use changes during short-term osmotic, salinity, and cold stress in Arabidopsis thaliana. This could inform on the early mechanisms plants use to survive adverse environment, which is important for efficient agricultural production. We found that carbon allocation from source to sinks, and partitioning into major metabolite pools in the source leaf, sink leaves and roots showed both conserved and divergent responses to the stresses examined. Carbohydrates changed under all abiotic stresses applied; plants re-partitioned 14C to maintain sugar levels under stress, primarily by reducing 14C into the storage compounds in the source leaf, and decreasing 14C into the pools used for growth processes in the roots. Salinity and cold increased 14C-flux into protein, but as the stress progressed, protein degradation increased to produce amino acids, presumably for osmoprotection. Our work also emphasized that stress regulated the carbon channeled into starch, and its metabolic turnover. These stress-induced changes in starch metabolism and sugar export in the source were partly accompanied by transcriptional alteration in the T6P/SnRK1 regulatory pathway that are normally activated by carbon starvation

    Is elevated SUA associated with a worse outcome in young Chinese patients with acute cerebral ischemic stroke?

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    <p>Abstract</p> <p>Background</p> <p>Elevated serum uric acid (SUA) levels can enhance its antioxidant prosperities and reduce the occurrence of cerebral infarction. Significantly elevated SUA levels have been associated with a better prognosis in patients with cerebral infarction; however, the results from some studies on the relationship between SUA and the prognosis of patients with cerebral infarction remain controversial.</p> <p>Methods</p> <p>We analyzed the relationship between SUA and clinical prognosis of 585 young Chinese adults with acute ischemic stroke as determined by the modified Rankin Scale at discharge. Using multivariate logistic regression modeling, we explore the relationship between SUA levels and patient's clinical prognosis.</p> <p>Results</p> <p>Lower SUA levels at time of admission were observed more frequently in the lowest quintile for patients with severe stroke (P = 0.02). Patients with cerebral infarction patients caused by small-vessel blockage had higher SUA concentrations (P = 0.01) and the lower mRS scores (P < 0.01) were observed in, while the lowest SUA concentrations and the highest mRS scores were seen in patients with cardiogenic cerebral infarction patients. Logistic regression analysis adjusted for confounders confirmed the following independent predictors for young cerebral infarction: uric acid (-0.003: 95%CI 0.994 to 0.999) and platelet (0.004, 95%CI 0.993 to 0.996).</p> <p>Conclusion</p> <p>Elevated SUA is an independent predictor for good clinical outcome of acute cerebral infarction among young adults.</p

    Disparities and risks of sexually transmissible infections among men who have sex with men in China: a meta-analysis and data synthesis.

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    BACKGROUND: Sexually transmitted infections (STIs), including Hepatitis B and C virus, are emerging public health risks in China, especially among men who have sex with men (MSM). This study aims to assess the magnitude and risks of STIs among Chinese MSM. METHODS: Chinese and English peer-reviewed articles were searched in five electronic databases from January 2000 to February 2013. Pooled prevalence estimates for each STI infection were calculated using meta-analysis. Infection risks of STIs in MSM, HIV-positive MSM and male sex workers (MSW) were obtained. This review followed the PRISMA guidelines and was registered in PROSPERO. RESULTS: Eighty-eight articles (11 in English and 77 in Chinese) investigating 35,203 MSM in 28 provinces were included in this review. The prevalence levels of STIs among MSM were 6.3% (95% CI: 3.5-11.0%) for chlamydia, 1.5% (0.7-2.9%) for genital wart, 1.9% (1.3-2.7%) for gonorrhoea, 8.9% (7.8-10.2%) for hepatitis B (HBV), 1.2% (1.0-1.6%) for hepatitis C (HCV), 66.3% (57.4-74.1%) for human papillomavirus (HPV), 10.6% (6.2-17.6%) for herpes simplex virus (HSV-2) and 4.3% (3.2-5.8%) for Ureaplasma urealyticum. HIV-positive MSM have consistently higher odds of all these infections than the broader MSM population. As a subgroup of MSM, MSW were 2.5 (1.4-4.7), 5.7 (2.7-12.3), and 2.2 (1.4-3.7) times more likely to be infected with chlamydia, gonorrhoea and HCV than the broader MSM population, respectively. CONCLUSION: Prevalence levels of STIs among MSW were significantly higher than the broader MSM population. Co-infection of HIV and STIs were prevalent among Chinese MSM. Integration of HIV and STIs healthcare and surveillance systems is essential in providing effective HIV/STIs preventive measures and treatments. TRIAL REGISTRATION: PROSPERO NO: CRD42013003721

    Interacting multi-channel topological boundary modes in a quantum Hall valley system

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    Symmetry and topology play key roles in the identification of phases of matter and their properties. Both concepts are central to understanding quantum Hall ferromagnets (QHFMs), two-dimensional electronic phases with spontaneously broken spin or pseudospin symmetry whose wavefunctions also have topological properties. Domain walls between distinct broken symmetry QHFM phases are predicted to host gapless one-dimensional (1D) modes that emerge due to a topological change of the underlying electronic wavefunctions at such interfaces. Although a variety of QHFMs have been identified in different materials, probing interacting electronic modes at these domain walls has not yet been accomplished. Here we use a scanning tunneling microscope (STM) to directly visualize the spontaneous formation of boundary modes, within a sign-changing topological gap, at domain walls between different valley-polarized quantum Hall phases on the surface of bismuth. By changing the valley occupation and the corresponding number of modes at the domain wall, we can realize different regimes where the valley-polarized channels are either metallic or develop a spectroscopic gap. This behavior is a consequence of Coulomb interactions constrained by the symmetry-breaking valley flavor, which determines whether electrons in the topological modes can backscatter, making these channels a unique class of interacting Luttinger liquids
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