Coherent effects in a three-photon CPT process of Ca+

Linewidth narrowing and other quantum coherent effects based on three-photon coherent population trapping (CPT) in Ca⁺ ions are investigated. If the propagation directions of the three lasers obey the phase matching condition, the dark linewidth resulting from the CPT can be very narrow, and it can be controlled by adjusting the parameters of the lasers.     

Numerical investigation of flow over a two-dimensional square cylinder with a synthetic jet generated by a bi-frequency signal

Applied Mathematics and Mechanics - The flow around a square cylinder with a synthetic jet positioned at the rear surface is numerically investigated with the unsteady Reynolds-averaged...     

New synthetic methodology leading to a series of novel heterocyclic α-aminophosphonates: a very attractive expansion of Kabachnik–Fields reaction

A convenient one-pot three-component approach leading to synthesis of a series of novel heterocyclic α-aminophosphonates starting either from 2-hydroxyacetophenones or 2-hydroxybenzaldehyes was developed.     

Sphere-cone-polynomial special window with good aberration characteristic

Optical windows with external surfaces shaped to satisfy operational environment needs are known as special windows. A novel special window, a sphere-cone-polynomial (SCP) window, is proposed. The formulas of this window shape are given. An SCP MgF2 window with a fineness ratio of 1.33 is designed as an example. The field-of-regard (FOR) angle is ±75°. From the window system simulation results obtained with the calculated fluid dynamics (CFD) and optical design software, we find that compared to the conventional window forms, the SCP shape can not only introduce relatively less drag in the airflow, but also have the minimal effect on imaging. So the SCP window optical system can achieve a high image quality across a super wide FOR without adding extra aberration correctors. The tolerance analysis results show that the optical performance can be maintained with a reasonable fabricating tolerance to manufacturing errors.     

Glycoengineering artificial receptors for microglia to phagocytose Aβ aggregates

Oligomeric and fibrillar amyloid-β (Aβ) are principally internalized via receptor-mediated endocytosis (RME) by microglia, the main scavenger of Aβ in the brain. Nevertheless, the inflammatory cascade will be evoked after vast Aβ aggregate binding to pattern recognition receptors on the cell membrane, which then significantly decreases the expression of these receptors and further deteriorate Aβ deposition. This vicious circle will weaken the ability of microglia for Aβ elimination. Herein, a combination of metabolic glycoengineering and self-triggered click chemistry is utilized to engineer microglial membranes with ThS as artificial Aβ receptors to promote microglia to phagocytose Aβ aggregates. Additionally, to circumvent the undesirable immune response during the process of the bioorthogonal chemistry reaction and Aβ-microglial interaction, Mn-porphyrin metal–organic frameworks (Mn-MOFs) with superoxide dismutase (SOD) and catalase (CAT) mimic activity are employed to carry N-azidoacetylmannosamine (AcManNAz) and eradicate over-expressed reactive oxygen species (ROSs). The artificial Aβ receptors independent of a signal pathway involved in immunomodulation as well as Mn-MOFs with antioxidant properties can synergistically promote the phagocytosis and clearance of Aβ with significantly enhanced activity and negligible adverse effects. The present study will not only provide valuable insight into the rational design of the microglial surface engineering strategy via bioorthogonal chemistry, but also hold great potential for other disease intervention associated with receptor starvation.

A combination of metabolic glycoengineering and self-triggered click chemistry is utilized to engineer a microglial membrane with ThS as artificial Aβ receptors to promote microglia to phagocytose Aβ aggregates.     

Neighbor distinguishing total choice number of sparse graphs via the Combinatorial Nullstellensatz

Acta Mathematicae Applicatae Sinica, English Series - Let G = (V,E) be a graph and ϕ: V ∪E → {1, 2, · · ·, k} be a total-k-coloring of G. Let f(v)(S(v)) denote the...     

Effect of chlorination and ozone pre-oxidation on the photobacteria acute toxicity for dissolved organic matter from sewage treatment plants

The effect of chlorination and ozone pre-oxidation on the photobacteria acute toxicity for dissolved organic matter (DOM) from sewage treatment plants was investigated in this study. The results show that ozone pre-oxidation enhanced the photobacteria acute toxicity of the water samples. DOM before and after ozone pre-oxidation was fractionated by resins into six kinds of hydrophobic and hydrophilic organics. The six fractions were chlorinated individually and the photobacteria acute toxicity before and after chlorination was tested. It was found that the percentage of hydrophilic organics in DOM significantly increased after ozone pre-oxidation and hydrophilic organics exhibited remarkably higher acute toxicity than hydrophobic organics. In view of potentiometric titration and fourier transform infrared (FTIR) analysis, the hydrophilic organics showed a rather higher content of ph-OH structures than hydrophobic organics.     

Hard X-ray lags of Cygnus X-1 on short timescales

Calculating the time lags over different timescales using the cross-correlation technique may lead to a biased estimate of small timescales. Given a timescale for lightcurve binning, we propose to subtract the local average instead of the global average during the cross-correlation, in order to filter variations on timescales larger than the bin size. The new method allows us to make an unbiased estimate of the time lags using RXTE/PCA data on timescales as small as ∼5 ms, where the Fourier technique becomes invalid. We calculate the time lag spectra of Cygnus X-1 at different spectral states with the new method, and find that the source appears to have similar X-ray lags on small timescales independent of its spectral states.