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Precise predictions for Λb → Λc semileptonic decays
We calculate the Λb→Λc?ν form factors and decay rates for all possible b→c?ν four-Fermi interactions beyond the Standard Model, including nonzero charged lepton masses and terms up to order αsΛQCD/mc,b and ΛQCD2/mc2 in the heavy quark effective theory. At this order, we obtain model independent predictions for semileptonic Λb→Λc decays in terms of only two unknown sub-subleading Isgur-Wise functions, which can be determined from fitting LHCb and lattice QCD data. We thus obtain model independent results for Λb→Λc?ν decays, including predictions for the ratio R(Λc)=B(Λb→Λcτν)/B(Λb→Λcμν) in the presence of new physics, that are more precise than prior results in the literature, and systematically improvable with better data on the decays with μ (or e) in the final state. We also explore tests of factorization in Λb→Λcπ decays, and we emphasize the importance of measuring at LHCb the double differential rate d2Γ(Λb→Λc?ν)/(dq2dcosθ), in addition to the q2 spectrum
Cultural-based visual expression: Emotional analysis of human face via Peking Opera Painted Faces (POPF)
© 2015 The Author(s) Peking Opera as a branch of Chinese traditional cultures and arts has a very distinct colourful facial make-up for all actors in the stage performance. Such make-up is stylised in nonverbal symbolic semantics which all combined together to form the painted faces to describe and symbolise the background, the characteristic and the emotional status of specific roles. A study of Peking Opera Painted Faces (POPF) was taken as an example to see how information and meanings can be effectively expressed through the change of facial expressions based on the facial motion within natural and emotional aspects. The study found that POPF provides exaggerated features of facial motion through images, and the symbolic semantics of POPF provides a high-level expression of human facial information. The study has presented and proved a creative structure of information analysis and expression based on POPF to improve the understanding of human facial motion and emotion
Bayesian network approach to fault diagnosis of a hydroelectric generation system
This study focuses on the fault diagnosis of a hydroelectric generation system with hydraulic-mechanical-electric structures. To achieve this analysis, a methodology combining Bayesian network approach and fault diagnosis expert system is presented, which enables the time-based maintenance to transform to the condition-based maintenance. First, fault types and the associated fault characteristics of the generation system are extensively analyzed to establish a precise Bayesian network. Then, the Noisy-Or modeling approach is used to implement the fault diagnosis expert system, which not only reduces node computations without severe information loss but also eliminates the data dependency. Some typical applications are proposed to fully show the methodology capability of the fault diagnosis of the hydroelectric generation system
Ultrasensitive PCR system for HBV DNA detection: Risk stratification for occult hepatitis B virus infection in English blood donors
Occult hepatitis B (HBV) infection (OBI), characterized by low viral loads, accounts for much of the risk of HBV transfusion-transmitted infection. With anticore antibodies (anti-HBc) screening introduced in England, the imperative to identify OBI donors has increased. We aimed to develop an ultra-sensitive PCR system and investigate risk factors for HBV DNA presence in blood donations. Seven extraction methods and three PCR assays were compared. The optimal system was sought to determine HBV DNA presence in anti-HBc-positive donations. Predictors of DNA positivity were subsequently investigated. Extraction from 5 mL of plasma increased sample representation and resulted in HBV DNA detection in low viral load samples (~0.5 IU/mL). Screening of 487 763 donations in 2022 identified two OBI donors and 2042 anti-HBc-positive donors, 412 of the latter with anti-HBs < 100 mIU/mL. Testing of 134 anti-HBc-positive donations utilizing the 5 mL extraction method identified two further HBV DNA-positive donations. Higher anti-HBc titer and anti-HBs negativity were significant predictors of DNA detectability in anti-HBc-positive donations. An ultrasensitive PCR assay identified potentially infectious donations increasing HBV DNA detection in anti-HBc-positive donors from 0.5% to 1.9%. Anti-HBc titers may further complement the risk stratification for DNA positivity in anti-HBc screening and minimize unnecessary donor deferral
HGF Mediates the Anti-inflammatory Effects of PRP on Injured Tendons
Platelet-rich plasma (PRP) containing hepatocyte growth factor (HGF) and other growth factors are widely used in orthopaedic/sports medicine to repair injured tendons. While PRP treatment is reported to decrease pain in patients with tendon injury, the mechanism of this effect is not clear. Tendon pain is often associated with tendon inflammation, and HGF is known to protect tissues from inflammatory damages. Therefore, we hypothesized that HGF in PRP causes the anti-inflammatory effects. To test this hypothesis, we performed in vitro experiments on rabbit tendon cells and in vivo experiments on a mouse Achilles tendon injury model. We found that addition of PRP or HGF decreased gene expression of COX-1, COX-2, and mPGES-1, induced by the treatment of tendon cells in vitro with IL-1β. Further, the treatment of tendon cell cultures with HGF antibodies reduced the suppressive effects of PRP or HGF on IL-1β-induced COX-1, COX-2, and mPGES-1 gene expressions. Treatment with PRP or HGF almost completely blocked the cellular production of PGE2 and the expression of COX proteins. Finally, injection of PRP or HGF into wounded mouse Achilles tendons in vivo decreased PGE2 production in the tendinous tissues. Injection of platelet-poor plasma (PPP) however, did not reduce PGE2 levels in the wounded tendons, but the injection of HGF antibody inhibited the effects of PRP and HGF. Further, injection of PRP or HGF also decreased COX-1 and COX-2 proteins. These results indicate that PRP exerts anti-inflammatory effects on injured tendons through HGF. This study provides basic scientific evidence to support the use of PRP to treat injured tendons because PRP can reduce inflammation and thereby reduce the associated pain caused by high levels of PGE2. © 2013 Zhang et al
The Impact in Older Women of Ovarian FMR1 Genotypes and Sub-Genotypes on Ovarian Reserve
We recently associated ovarian FMR1genotypes and sub-genotypes with distinct ovarian aging patterns. How they impact older females is, however, unknown. We, therefore, investigated 217 consecutive first in vitro fertilization (IVF) cycles in women >40 assessing oocyte yields, stratified for better (anti-Müllerian hormone, AMH >1.05 ng/mL) or poorer (AMH≤1.05 ng/mL) functional reserve (FOR)). Mean age was 42.4±2.0 years, mean AMH 0.76±0.92 ng/mL and mean oocyte yield 5.3±5.4. Overall, and in women with better FOR, FMR1 did not affect oocyte yields. With poorer FOR (AMH≤1.05 ng/mL) women with het-norm/high, however, demonstrated higher oocyte yields (5.0±3.8) than those with het-norm/low sub-genotype 3.1±2.5; P = 0.03), confirmed after log conversion. Known associated with low FOR at young age, het-norm/high, thus, appears to preserve FOR into older age, and both het sub-genotypes appear to expand female reproductive lifespan into opposite directions
Comparison of Mortality Outcomes in Acute Myocardial Infarction Patients With or Without Standard Modifiable Cardiovascular Risk Factors
Background: Acute myocardial infarction (AMI) cases have decreased in part due to the advent of targeted therapies for standard modifiable cardiovascular disease risk factors (SMuRF). Recent studies have reported that ST-elevation myocardial infarction (STEMI) patients without SMuRF (termed "SMuRF-less") may be increasing in prevalence and have worse outcomes than "SMuRF-positive" patients. As these studies have been limited to STEMI and comprised mainly Caucasian cohorts, we investigated the changes in the prevalence and mortality of both SMuRF-less STEMI and non-STEMI (NSTEMI) patients in a multiethnic Asian population. Methods: We evaluated 23,922 STEMI and 62,631 NSTEMI patients from a national multiethnic registry. Short-term cardiovascular and all-cause mortalities in SMuRF-less patients were compared to SMuRF-positive patients. Results: The proportions of SMuRF-less STEMI but not of NSTEMI have increased over the years. In hospitals, all-cause and cardiovascular mortality and 1-year cardiovascular mortality were significantly higher in SMuRF-less STEMI after adjustment for age, creatinine, and hemoglobin. However, this difference did not remain after adjusting for anterior infarction, cardiopulmonary resuscitation (CPR), and Killip class. There were no differences in mortality in SMuRF-less NSTEMI. In contrast to Chinese and Malay patients, SMuRF-less patients of South Asian descent had a two-fold higher risk of in-hospital all-cause mortality even after adjusting for features of increased disease severity. Conclusion: SMuRF-less patients had an increased risk of mortality with STEMI, suggesting that there may be unidentified nonstandard risk factors predisposing SMuRF-less patients to a worse prognosis. This group of patients may benefit from more intensive secondary prevention strategies to improve clinical outcomes
Temperature dependent CO2 behavior in microporous 1-D channels of a metal-organic framework with multiple interaction sites
The MOF with the encapsulated CO2 molecule shows that the CO2 molecule is ligated to the unsaturated Cu(II) sites in the cage using its Lewis basic oxygen atom via an angular eta(1)-(O-A) coordination mode and also interacts with Lewis basic nitrogen atoms of the tetrazole ligands using its Lewis acidic carbon atom. Temperature dependent structure analyses indicate the simultaneous weakening of both interactions as temperature increases. Infrared spectroscopy of the MOF confirmed that the CO2 interaction with the framework is temperature dependent. The strength of the interaction is correlated to the separation of the two bending peaks of the bound CO2 rather than the frequency shift of the asymmetric stretching peak from that of free CO2. The encapsulated CO2 in the cage is weakly interacting with the framework at around ambient temperatures and can have proper orientation for wiggling out of the cage through the narrow portals so that the reversible uptake can take place. On the other hand, the CO2 in the cage is restrained at a specific orientation at 195 K since it interacts with the framework strong enough using the multiple interaction sites so that adsorption process is slightly restricted and desorption process is almost clogged.ope
Control of Centrin Stability by Aurora A
Aurora A is an oncogenic serine/threonine kinase which can cause cell transformation and centrosome amplification when over-expressed. Human breast tumors show excess Aurora A and phospho-centrin in amplified centrosomes. Here, we show that Aurora A mediates the phosphorylation of and localizes with centrin at the centrosome, with both proteins reaching maximum abundance from prophase through metaphase, followed by their precipitous loss in late stages of mitosis. Over-expression of Aurora A results in excess phospho-centrin and centrosome amplification. In contrast, centrosome amplification is not seen in cells over-expressing Aurora A in the presence of a recombinant centrin mutant lacking the serine phosphorylation site at residue 170. Expression of a kinase dead Aurora A results in a decrease in mitotic index and abrogation of centrin phosphorylation. Finally, a recombinant centrin mutation that mimics centrin phosphorylation increases centrin's stability against APC/C-mediated proteasomal degradation. Taken together, these results suggest that the stability of centrin is regulated in part by Aurora A, and that excess phosphorylated centrin may promote centrosome amplification in cancer
Two TPX2-Dependent Switches Control the Activity of Aurora A
Aurora A is an important oncogenic kinase for mitotic spindle assembly and a potentially attractive target for human cancers. Its activation could be regulated by ATP cycle and its activator TPX2. To understand the activation mechanism of Aurora A, a series of 20 ns molecular dynamics (MD) simulations were performed on both the wild-type kinase and its mutants. Analyzing the three dynamic trajectories (Aurora A-ATP, Aurora A-ADP, and Aurora A-ADP-TPX2) at the residue level, for the first time we find two TPX2-dependent switches, i.e., switch-1 (Lys-143) and switch-2 (Arg-180), which are tightly associated with Aurora A activation. In the absence of TPX2, Lys-143 exhibits a “closed” state, and becomes hydrogen-bonded to ADP. Once TPX2 binding occurs, switch-1 is forced to “open” the binding site, thus pulling ADP away from Aurora A. Without facilitation of TPX2, switch-2 exits in an “open” conformation which accompanies the outward-flipping movement of P·Thr288 (in an inactive conformation), leading to the crucial phosphothreonine exposed and accessible for deactivation. However, with the binding of TPX2, switch-2 is forced to undergo a “closed” movement, thus capturing P·Thr288 into a buried position and locking its active conformation. Analysis of two Aurora A (K143A and R180A) mutants for the two switches further verifies their functionality and reliability in controlling Aurora activity. Our systems therefore suggest two switches determining Aurora A activation, which are important for the development of aurora kinase inhibitors
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