Linear Stability of Equilibrium Points in the Generalized Photogravitational Chermnykh's Problem

The equilibrium points and their linear stability has been discussed in the generalized photogravitational Chermnykh's problem. The bigger primary is being considered as a source of radiation and small primary as an oblate spheroid. The effect of radiation pressure has been discussed numerically. The collinear points are linearly unstable and triangular points are stable in the sense of Lyapunov stability provided $\mu< \mu_{Routh}=0.0385201$. The effect of gravitational potential from the belt is also examined. The mathematical properties of this system are different from the classical restricted three body problem

Proteomic profiling of proteins associated with the rejuvenation of Sequoia sempervirens (D. Don) Endl

Background: Restoration of rooting competence is important for rejuvenation in Sequoia sempervirens (D. Don) Endl and is achieved by repeatedly grafting Sequoia shoots after 16 and 30 years of cultivation in vitro. Results: Mass spectrometry-based proteomic analysis revealed three proteins that differentially accumulated in different rejuvenation stages, including oxygen-evolving enhancer protein 2 (OEE2), glycine-rich RNA-binding protein (RNP), and a thaumatin-like protein. OEE2 was found to be phosphorylated and a phosphopeptide (YEDNFDGNSNVSVMVpTPpTDK) was identified. Specifically, the protein levels of OEE2 increased as a result of grafting and displayed a higher abundance in plants during the juvenile and rejuvenated stages. Additionally, SsOEE2 displayed the highest expression levels in Sequoia shoots during the juvenile stage and less expression during the adult stage. The expression levels also steadily increased during grafting. Conclusion: Our results indicate a positive correlation between the gene and protein expression patterns of SsOEE2 and the rejuvenation process, suggesting that this gene is involved in the rejuvenation of Sequoia sempervirens

Temperature and Frequency Dependence of Complex Conductance of Ultrathin YBa2Cu3O7-x Films: A Study of Vortex-Antivortex Pair Unbinding

We have studied the temperature dependencies of the complex sheet conductance of 1-3 unit cell (UC) thick YBa2Cu3O7-x films sandwiched between semiconducting Pr0.6Y0.4Ba2Cu3O7-x layers at high frequencies. Experiments have been carried out in a frequency range between: 2 - 30 MHz with one-spiral coil technique, 100 MHz - 1 GHz frequency range with a new technique using the spiral coil cavity and at 30 GHz by aid of a resonant cavity technique. The real and imaginary parts of the mutual-inductance between a coil and a film were measured and converted to complex conductivity by aid of the inversion procedure. We have found a quadratic temperature dependence of the kinetic inductance, L_k^-1(T), at low temperatures independent of frequency, with a break in slope at T^dc_BKT, the maximum of real part of conductance and a large shift of the break temperature and the maximum position to higher temperatures with increasing frequency. We obtain from these data the universal ratio T^dc_BKT/L_k^-1(T^dc_BKT) = 25, 25, and 17 nHK for 1-, 2- and 3UC films, respectively in close agreement with theoretical prediction of 12 nHK for vortex-antivortex unbinding transition. The activated temperature dependence of the vortex diffusion constant was observed and discussed in the framework of vortex-antivortex pair pinning. PACS numbers: 74.80.Dm, 74.25.Nf, 74.72.Bk, 74.76.BzComment: PDF file, 10 pages, 6 figures, to be published in J. Low Temp. Phys.; Proc. of NATO ARW: VORTEX 200

Dynamic Scaling and Two-Dimensional High-Tc Superconductors

There has been ongoing debate over the critical behavior of two-dimensional superconductors; in particular for high Tc superconductors. The conventional view is that a Kosterlitz-Thouless-Berezinskii transition occurs as long as finite size effects do not obscure the transition. However, there have been recent suggestions that a different transition actually occurs which incorporates aspects of both the dynamic scaling theory of Fisher, Fisher, and Huse and the Kosterlitz-Thouless-Berezinskii transition. Of general interest is that this modified transition apparently has a universal dynamic critical exponent. Some have countered that this apparent universal behavior is rooted in a newly proposed finite-size scaling theory; one that also incorporates scaling and conventional two-dimensional theory. To investigate these issues we study DC voltage versus current data of a 12 angstrom thick YBCO film. We find that the newly proposed scaling theories have intrinsic flexibility that is relevant to the analysis of the experiments. In particular, the data scale according to the modified transition for arbitrarily defined critical temperatures between 0 K and 19.5 K, and the temperature range of a successful scaling collapse is related directly to the sensitivity of the measurement. This implies that the apparent universal exponent is due to the intrinsic flexibility rather than some real physical property. To address this intrinsic flexibility, we propose a criterion which would give conclusive evidence for phase transitions in two-dimensional superconductors. We conclude by reviewing results to see if our criterion is satisfied.Comment: 14 page

Arteriopathy diagnosis in childhood arterial ischemic stroke: results of the vascular effects of infection in pediatric stroke study.

Background and purposeAlthough arteriopathies are the most common cause of childhood arterial ischemic stroke, and the strongest predictor of recurrent stroke, they are difficult to diagnose. We studied the role of clinical data and follow-up imaging in diagnosing cerebral and cervical arteriopathy in children with arterial ischemic stroke.MethodsVascular effects of infection in pediatric stroke, an international prospective study, enrolled 355 cases of arterial ischemic stroke (age, 29 days to 18 years) at 39 centers. A neuroradiologist and stroke neurologist independently reviewed vascular imaging of the brain (mandatory for inclusion) and neck to establish a diagnosis of arteriopathy (definite, possible, or absent) in 3 steps: (1) baseline imaging alone; (2) plus clinical data; (3) plus follow-up imaging. A 4-person committee, including a second neuroradiologist and stroke neurologist, adjudicated disagreements. Using the final diagnosis as the gold standard, we calculated the sensitivity and specificity of each step.ResultsCases were aged median 7.6 years (interquartile range, 2.8-14 years); 56% boys. The majority (52%) was previously healthy; 41% had follow-up vascular imaging. Only 56 (16%) required adjudication. The gold standard diagnosis was definite arteriopathy in 127 (36%), possible in 34 (9.6%), and absent in 194 (55%). Sensitivity was 79% at step 1, 90% at step 2, and 94% at step 3; specificity was high throughout (99%, 100%, and 100%), as was agreement between reviewers (κ=0.77, 0.81, and 0.78).ConclusionsClinical data and follow-up imaging help, yet uncertainty in the diagnosis of childhood arteriopathy remains. This presents a challenge to better understanding the mechanisms underlying these arteriopathies and designing strategies for prevention of childhood arterial ischemic stroke

Systematic Review of Medicine-Related Problems in Adult Patients with Atrial Fibrillation on Direct Oral Anticoagulants

New oral anticoagulant agents continue to emerge on the market and their safety requires assessment to provide evidence of their suitability for clinical use. There-fore, we searched standard databases to summarize the English language literature on medicine-related problems (MRPs) of direct oral anticoagulants DOACs (dabigtran, rivaroxban, apixban, and edoxban) in the treatment of adults with atri-al fibrillation. Electronic databases including Medline, Embase, International Pharmaceutical Abstract (IPA), Scopus, CINAHL, the Web of Science and Cochrane were searched from 2008 through 2016 for original articles. Studies pub-lished in English reporting MRPs of DOACs in adult patients with AF were in-cluded. Seventeen studies were identified using standardized protocols, and two reviewers serially abstracted data from each article. Most articles were inconclusive on major safety end points including major bleeding. Data on major safety end points were combined with efficacy. Most studies inconsistently reported adverse drug reactions and not adverse events or medication error, and no definitions were consistent across studies. Some harmful drug effects were not assessed in studies and may have been overlooked. Little evidence is provided on MRPs of DOACs in patients with AF and, therefore, further studies are needed to establish the safety of DOACs in real-life clinical practice

Antibacterial evaluation of Styrax pohlii and isolated compounds

The antibacterial activity of the compounds egonol (1) and homoegonol (2), of the crude ethanolic extract of Styrax pohlii (Styracaceae) aerial parts (EE), and of its n-hexane (HF), EtOAc (EF), n-BuOH (BF), and hydromethanolic (HMF) fractions was evaluated against the following microorganisms: Streptococcus pneumoniae (ATCC 6305), S. pyogenes (ATCC 19615), Haemophilus influenzae (ATCC 10211), Pseudomonas aeruginosa (ATCC 27853), and Klebsiella pneumoniae (ATCC 10031). The broth microdilution method was used for determination of the minimum inhibitory concentration (MIC) during preliminary evaluation of antibacterial activity. The EE yielded MIC values of 400 µg/mL for S. pneumoniae and P. aeruginosa and 300 µg/mL for H. influenzae. The HF and EF fractions exhibited enhanced antibacterial activity, with MIC values of 200 µg/mL against S. pneumoniae, but only EF displayed activity against H. influenzae (MIC 200 µg/mL). The best MIC value with compounds 1 and 2 (400 µg/mL) was obtained for (1) against S. pneumoniae and P. aeruginosa. Therefore, 1 exhibited weak antibacterial activity against these standard strains

Ferulic acid and derivatives: molecules with potential application in the pharmaceutical field

Ferulic acid is a phenolic acid widely distributed in the plant kingdom. It presents a wide range of potential therapeutic effects useful in the treatments of cancer, diabetes, lung and cardiovascular diseases, as well as hepatic, neuro and photoprotective effects and antimicrobial and anti-inflammatory activities. Overall, the pharmaceutical potential of ferulic acid can be attributed to its ability to scavenge free radicals. However, recent studies have revealed that ferulic acid presents pharmacological properties beyond those related to its antioxidant activity, such as the ability to competitively inhibit HMG-CoA reductase and activate glucokinase, contributing to reduce hypercholesterolemia and hyperglycemia, respectively. The present review addresses ferulic acid dietary sources, the pharmacokinetic profile, antioxidant action mechanisms and therapeutic effects in the treatment and prevention of various diseases, in order to provide a basis for understanding its mechanisms of action as well as its pharmaceutical potential