205 research outputs found
Controlling multiple returnings in non-sequential double ionization with orthogonal two-color laser pulses
With the three-dimensional semi-classical ensemble model, we studied the non-sequential double ionization by orthogonal two-color laser pulses. Our calculations show that the proportion of events experiencing multiple returnings, the sum of the final energies of two electrons, and the ion momentum distribution depend on the relative phase of the two-color fields, exhibiting oscillatory behavior with a period of π. Back analysis of these trajectories reveals that we can control the recollision energy of the electron by changing the relative phase of the two-color laser pulse. As a consequence, the trajectories of multiple-returning ions change with the relative phase, resulting in relative-phase-dependent ion momentum distributions. The result shows that the momentum distribution of the ions in the trajectories of multiple returnings is clearly wider than that for the case of single returning. For the multiple-returning events, the binary recollision leads to a smaller scattering angle of the first electron
Preparing and characterizing Fe3O4@cellulose nanocomposites for effective isolation of cellulose-decomposing microorganisms
This study developed Fe3O4@cellulose nanocomposites by co-precipitation synthesis for bacteria capture and isolation. By surface modification with cellulose, the Fe3O4@cellulose nanocomposites have 20 nm average particle size and 3.3–24.9 emu/g saturation magnetization. Living bacteria could be captured by the Fe3O4@cellulose nanocomposites and harvested by magnetic field, with high efficiency (95.1%) and stability (>99.99%). By metabolizing cellulose and destroying the Fe3O4@cellulose@bacteria complex, cellulose-decomposing microorganisms lost the magnetism. They were therefore able to be isolated from the inert microbial community and the separation efficiency achieved over 99.2%. This research opened a door to cultivate the uncultivable cellulose-decomposing microorganisms in situ and further characterize their ecological functions in natural environment
Resveratrol regulates insulin resistance to improve the glycolytic pathway by activating SIRT2 in PCOS granulosa cells
ScopeInsulin resistance (IR) has a close relationship with the main clinical manifestations of patients with PCOS; hence, the research and development of new drugs to treat PCOS by improving IR is a desiderate task at present. Resveratrol (RES) possesses a variety of beneficial pharmacological functions, such as antioxidation, anti-inflammatory, regulating glucose, and lipid metabolism. However, whether RES could improve IR and the underlying mechanisms remained unclear in PCOS.Methods and resultsSD rats received a high-fat diet and letrozole for 30 days to establish the PCOS model and then intervened with RES for 30 days. The results demonstrated that RES played a protective role on the IR in PCOS rats, which significantly decreased the levels of blood glucose and serum insulin, up regulated the expression of IGF1R, and down regulated the expression of IGF1. In vitro, KGN cells were treated with insulin, RES, and AGK2, respectively. We found that a high dose of insulin (4μg/mL) significantly inhibited KGN cell viability, decreased the level of lactic acid, and increased the level of pyruvate, while RES (25μM) attenuated the growth-inhibitory effect, as well as increased the level of lactic acid and decreased the level of pyruvate after high levels of insulin treatment. Simultaneously, RES up regulated the expression level of the crucial rate-limiting enzymes relating to glycolytic pathways, such as LDHA, HK2, and PKM2. Furthermore, AGK2 remarkably inhibited the expression level of SIRT2, which was similar to the same negative effects processed by insulin. Meanwhile, RES overtly repaired the glycolysis process by reversing the levels of lactic acid and pyruvate, together with up regulating the expression level of LDHA, HK2, and PKM2, after AGK2 treatment.ConclusionRES could effectively improve insulin resistance and restore the glycolysis pathway by regulating SIRT2, which may contribute to attenuating the ovarian damage of PCOS rats and provide a potential treatment for patients with PCOS
Disinfection efficacy of green synthesized gold nanoparticles for medical disinfection applications
Background: In recent times, biosyntheses of metal nanoparticles were used for several life rescue applications. In this study, Dillenia indica leaf aqueous extract was utilized for the synthesis of gold nanoparticles.Objective: To test anti-microbial properties of biologically fabricated gold nanoparticles.Methods: Gold nanoparticles were efficiently prepared by making use of aqueous leaf extract of Dillenia indica. The excitation of formed AuNPs was confirmed using UV–Vis spectrophotometer. In particular, absorption spectra of AuNPs exhibited a well-defined SPR band centered at around 530 nm.Results: The high-resolution Scanning Electron Microscope (SEM) results of the obtained AuNPs confirmed the formation of particles with a size range of 5–50 nm. The ultra-high resolution TEM (UHRTEM) images displayed clear lattice fringes on the particle surfaces. Single crystalline nature of the biosynthesized AuNPs was represented by means of selected-area electron diffraction pattern.Conclusion: The antibacterial activity of AuNPs revealed significant activity towards both gram negative and gram positive bacteria signifying their potential disinfection related applications in medicine and biology.Keywords: Dillenia indica leaves, disinfection, AuNPs
Comparative performance evaluation of basalt fiber–modified hot in-place (HIP) recycling asphalt mixtures: site mixture versus lab mixture
The performance improvement of hot in-place recycling asphalt mixtures has been a hot topic recently due to the widespread application of HIP recycling technology. Based on the maintenance project of the provincial pavement G233 Baoying section, basalt fibers were introduced into HIP recycling mixtures. The effect of basalt fiber on the comprehensive performance of recycled mixtures was investigated using high temperature stability tests, cracking resistance tests, water stability tests, and dynamic modulus tests. Moreover, the performance of site mixtures was comparatively investigated with that of lab-made mixtures to further explore the site mixing effect on the mixture performance. The results showed that the recycled mixtures without basalt fiber presented unqualified cracking resistance even though proper mixture design was performed. The addition of basalt fibers could greatly enhance the rutting resistance, low-temperature cracking resistance, and stripping resistance of HIP recycled mixtures by 105.2%, 102.3%, and 46.9%, respectively. Moreover, the mixing method also had a significant impact on the properties of mixtures. The recycled mixtures produced by the site re-mixing method showed inferior performance compared to that of mixtures produced by the lab mixing method. Specifically, the dynamic stability, low temperature failure strain, and stripping point values reduced by 44.1%, 16.2%, and 11.7%, respectively, indicating that the site re-mixing process was not as effective as the lab mixing process due to the weaker blending and mixing procedures of the site equipment. The results could be beneficial for the utilization of basalt fiber in HIP recycling technology
Experimental generation of genuine four-partite entangled states with total three-party correlation for continuous variables
We experimentally prepare a new type of continuous variable genuine
four-partite entangled states, the quantum correlation property of which is
different from that of the four-mode GHZ and cluster states, and which has not
any qubit counterpart to be proposed at present. In the criterion inequalities
for the full inseparability of the genuine four-partite entangled states, the
amplitude and phase quadrature correlation variances totally consisting of
three-party combination from the four entangled modes are involved. The
measured correlation variances among the quadratures of the prepared entangled
states satisfy the sufficient requirements for the full inseparability. The
type of entangled states has especially potential application in quantum
information with continuous quantum variables
Experimental Demonstration of Quantum Entanglement Between Frequency-Nondegenerate Optical Twin Beams
The quantum entanglement of amplitude and phase quadratures between two
intense optical beams with the total intensity of 22mW and the frequency
difference of 1nm, which are produced from an optical parametric oscillator
operating above threshold, is experimentally demonstrated with two sets of
unbalanced Mach-Zehnder interferometers. The measured quantum correlations of
intensity and phase are in reasonable agreement with the results calculated
based on a semi-classical analysis of the noise characteristics given by C.
Fabre et al.Comment: Accepted in Opt. Let
Plant-Mediated RNAi for Controlling Apolygus lucorum
The polyphagous mirid bug Apolygus lucorum (Heteroptera: Miridae) is a serious pest of agricultural crops in China, with more than 200 species of host plants including two very important crops, maize and soybean. Currently, prevention and control of A. lucorum rely mainly on chemical pesticides that cause environmental as well as health related problems. Plant-mediated RNAi has proven to offer great potential for pest control in the past decade. In this study, we screened and obtained seven candidate genes (Alucβ-actin, AlucV-ATPase-A/D/E, AlucEif5A, AlucEcR-A, AlucIAP) by injection-based RNAi which produced A. lucorum mortality rates of 46.01–82.32% at day 7 after injection. Among them, the plant-mediated RNAi of AlucV-ATPase-E was successfully introduced into transgenic maize and soybean, and the populations of A. lucorum were significantly decreased following feeding on the transgenic maize and soybean. These results are intended to provide helpful insight into the generation of bug-resistant plants through a plant-mediated RNAi strategy
Disinfection efficacy of green synthesized gold nanoparticles for medical disinfection applications
Background: In recent times, biosyntheses of metal nanoparticles were
used for several life rescue applications. In this study, Dillenia
indica leaf aqueous extract was utilized for the synthesis of gold
nanoparticles. Objective: To test anti-microbial properties of
biologically fabricated gold nanoparticles. Methods: Gold nanoparticles
were efficiently prepared by making use of aqueous leaf extract of
Dillenia indica. The excitation of formed AuNPs was confirmed using
UV\u2013Vis spectrophotometer. In particular, absorption spectra of
AuNPs exhibited a well-defined SPR band centered at around 530 nm.
Results: The high-resolution Scanning Electron Microscope (SEM) results
of the obtained AuNPs confirmed the formation of particles with a size
range of 5\u201350 nm. The ultra-high resolution TEM (UHRTEM) images
displayed clear lattice fringes on the particle surfaces. Single
crystalline nature of the biosynthesized AuNPs was represented by means
of selected-area electron diffraction pattern. Conclusion: The
antibacterial activity of AuNPs revealed significant activity towards
both gram negative and gram positive bacteria signifying their
potential disinfection related applications in medicine and biology.
DOI: https://dx.doi.org/10.4314/ahs.v19i1.17 Cite as: Huang Q, Luo A,
Jiang L, Zhou Y, Yang Y, Liu Q, et al. Disinfection efficacy of green
synthesized gold nanoparticles for medical disinfection applications.
Afri Health Sci. 2019;19(1). 1441-1458. https://dx.doi.
org/10.4314/ahs.v19i1.1
Breast cancer survival analysis with molecular subtypes : an initial step
As a predominant threat to women's health world-wide, breast cancer has become increasingly important in on-cology research. The discovery of molecular subtypes of breast cancer has led to more subtype oriented treatment and prognosis prediction. Effective prognosis models help to estimate the recurrence as well as the quality and duration of survival, leading to more personalized treatments. However, most traditional prognostic models either ignore molecular subtypes or only make limited use of them. The roles of molecular subtypes in the development and treatment of breast cancer have not been fully revealed. With the over 1200 cases collected by Sir Run Run Shaw Hospital of Zhejiang University in the past two decades, we aim to improve understanding of molecular subtypes and their impacts on the prognosis via data analysis in the long run. As the initial stage, this short paper presents our preliminary work of logistic regression experiments with the data. Though molecular subtypes have not been included the tentative model, they are to be explored further in following stages
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