抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

Laser ablation of solid targets by 0.2–5000 ps Ti: Sapphire laser pulses is studied. Theoretical models and qualitative explanations of experimental results are presented. Advantages of femtosecond lasers for precise material processing are discussed and demonstrated.

Femtosecond, picosecond and nanosecond laser ablation of solids

This Review article summarizes the key advantages of using quantum dots (QDs) as luminophores in light-emitting devices (LEDs) and outlines the operating mechanisms of four types of QD-LED. The key scientific and technological challenges facing QD-LED commercialization are identified, together with on-going strategies to overcome these challenges.

Emergence of colloidal quantum-dot light-emitting technologies

We report for the first time on a hole conductor-free mesoscopic methylammonium lead iodide (CH3NH3PbI3) perovskite/TiO2 heterojunction solar cell, produced by deposition of perovskite nanoparticles from a solution of CH3NH3I and PbI2 in γ-butyrolactone on a 400 nm thick film of TiO2 (anatase) nanosheets exposing (001) facets. A gold film was evaporated on top of the CH3NH3PbI3 as a back contact. Importantly, the CH3NH3PbI3 nanoparticles assume here simultaneously the roles of both light harvester and hole conductor, rendering superfluous the use of an additional hole transporting material. The simple mesoscopic CH3NH3PbI3/TiO2 heterojunction solar cell shows impressive photovoltaic performance, with short-circuit photocurrent Jsc= 16.1 mA/cm2, open-circuit photovoltage Voc = 0.631 V, and a fill factor FF = 0.57, corresponding to a light to electric power conversion efficiency (PCE) of 5.5% under standard AM 1.5 solar light of 1000 W/m2 intensity. At a lower light intensity of 100W/m2, a PCE of 7.3% was m...

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Mesoscopic CH3NH3PbI3/TiO2 heterojunction solar cells.

Summary form only given. Fundamental processes in atoms, molecules, as well as condensed matter are triggered or mediated by the motion of electrons inside or between atoms. Electronic dynamics on atomic length scales tends to unfold within tens to thousands of attoseconds (1 attosecond [as] = 10-18 s). Recent breakthroughs in laser science are now opening the door to watching and controlling these hitherto inaccessible microscopic dynamics. The key to accessing the attosecond time domain is the control of the electric field of (visible) light, which varies its strength and direction within less than a femtosecond (1 femtosecond = 1000 attoseconds). Atoms exposed to a few oscillations cycles of intense laser light are able to emit a single extreme ultraviolet (XUV) burst lasting less than one femtosecond. Full control of the evolution of the electromagnetic field in laser pulses comprising a few wave cycles have recently allowed the reproducible generation and measurement of isolated sub-femtosecond XUV pulses, demonstrating the control of microscopic processes (electron motion and photon emission) on an attosecond time scale. These tools have enabled us to visualize the oscillating electric field of visible light with an attosecond "oscilloscope", to control single-electron and probe multi-electron dynamics in atoms, molecules and solids. Recent experiments hold promise for the development of an attosecond X-ray source, which may pave the way towards 4D electron imaging with sub-atomic resolution in space and time.

Attosecond Physics

The global need for clean water requires sustainable technology for purifying contaminated water. Highly eﬃcient solar-driven photodegradation is a sustainable strategy for wastewater treatment. In this work, we demonstrate that the photodegradation eﬃciency of micropollutants in water can be improved by ∼ 2-24 times by leveraging polymeric microlenses (MLs). These microlenses (MLs) are fabricated from the in-situ polymerization of surface nanodroplets. We found that photodegradation eﬃciency ( η ) in water correlates approximately linearly with the sum of the intensity from all focal points of MLs, although no diﬀerence in the photodegradation pathway is detected from the chemical analysis of the byproducts. With the same overall power over a given surface area, η is doubled by using ordered arrays, compared to heterogeneous MLs on an unpatterned substrate. Higher η from ML arrays may be attributed to a coupled eﬀect from the focal points on the same plane that creates high local concentrations of active species to further speed up the rate of photodegradation. As a proof-of-concept for ML-enhanced water treatment, MLs were formed on the inner wall of glass bottles that were used as containers for water to be treated. Three representative micropollutants (norﬂoxacin, sulfadiazine, and sulfamethoxazole) in the bottles functionalized by MLs were photodegraded by 30% to 170% faster than in normal bottles. Our ﬁndings suggest that the ML-enhanced photodegradation may lead to a highly eﬃcient solar water puriﬁcation approach without a large solar collector size. Such an approach may be particularly suitable for portable transparent bottles in remote regions.

Surface Microlenses for Much More Efficient Photodegradation in Water Treatment

To improve the limitations of traditional microwave absorbing materials (MAMs), such as high density and narrow absorption bandwidth, neodymium oxide/carbon nanofiber (Nd2O3/CNF) composites were successfully prepared by electrospinning technology combined with a high-temperature carbonization process. The three-dimensional network structure of CNFs provides a path for conducting electromagnetic waves, and its porous structure also increases the multiple reflections of electromagnetic waves in the composite fibers, which significantly attenuates the energy of electromagnetic waves. Additionally rare-earth elements have a unique electronic arrangement on the 4f electron layer. The addition of Nd2O3 can turn the dielectric constant of Nd2O3/CNF and optimize the impedance matching. Also, Nd2O3 nanoparticles (Nd2O3–NPs) resulted in numerous of heterojunction surfaces and introduced the magnetic loss mechanism. Under the combined action of the double loss mechanism, the minimum reflection loss of Nd2O3/CNF composite fiber is −66.7 dB at 9.36 GHz, and the effective absorption bandwidth is 4.4 GHz (7.68–12.08 GHz). The radar cross section simulation results also prove that the composite fibers exhibit strong consumption of electromagnetic waves. Additionally, the excellent flexibility and anticorrosion properties of the composite fibers make them satisfy the multifunctional requirements of MAMs. 

Multifunctional Nd2O3/CNFs Composite for Microwave Absorption and Anti-Corrosion Applications

Temperature Dependence of the Diffuse-Scattering Fine Structure in Cu-Pd Alloys

We report observation of electron self-injection and acceleration in a plasma accelerator driven by the Texas petawatt laser at 1017 cm−3 plasma density, an order of magnitude lower density than previous self-injected laser-plasma accelerators.

Self-injected petawatt laser-driven plasma electron acceleration in 10 17 cm −3 plasma

AlN nanotubes (NTs) have many novel characteristics and great potential applications in electronic and optoelectronic nanodevices. However, little is known about the influence of Mg-O co-doping effects on their optical properties. Here, we focus on investigating the electronic structures, clarify the interband optical transition mechanism and give a clear atomic picture for the important electron/hole localization centre in AlN:Mg-O NTs using the GGA-1/2 method. We find that the Mg doping efficiency can be improved effectively due to O doping in AlN NTs. The Mg and O form Mg-O defect complex easily along the AlN NT axis (C-axis). The Mg-O defect complex can result in a remarkable charge transfer around it and modify the valence band maximum and conduction band minimum significantly. Meanwhile, the Mg-O defect complex also forms the important exciton localization centre and effectively enhances the interband radiative recombination rate. Moreover, the light emission/absorption sensitively depends on its polarization. The parallel polarized light () is much stronger than the perpendicular one (). The Mg-O co-doping thus paves a new way for improving the performance of electronic and optoelectronic nanodevices based on AlN NTs.

https://iopscience.iop.org/article/10.1088/2053-1591/1/2/025030/pdf

Xihua Wang

Papers

Surface Microlenses for Much More Efficient Photodegradation in Water Treatment

Multifunctional Nd2O3/CNFs Composite for Microwave Absorption and Anti-Corrosion Applications

Temperature Dependence of the Diffuse-Scattering Fine Structure in Cu-Pd Alloys

Self-injected petawatt laser-driven plasma electron acceleration in 10 17 cm −3 plasma

Band edge modulation and interband optical transition in AlN:Mg-O nanotubes