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We propose obtaining polarized proton beams based on CO2-laser-driven collisionless shock acceleration (CSA) of the pre-polarized HCl gas. By tailoring the density profile of the pre-polarized HCl gas, the intense CO2laser pulse heats the plasma target and forms a strong shock that reflects the polarized protons to high energy. According to particle-in-cell simulations implemented with the spin dynamics, directional proton beams of several MeV were generated at a total beam polarization of over 80%. Simulations showed that proton spin precession occurred in the azimuthal magnetic fields generated by the Biermann effect and plasma currents. The latter was the main depolarization mechanism in the early stage of shock wave formation. For CSA at CO2laser intensities around 1017–1018W/cm2, the proton depolarization was insignificant and the beam polarization purity was preserved. As pre-polarized hydrogen targets were available at gaseous densities in-state-of-art facilities, CSA driven by relatively long wavelength lasers provided a feasible solution for obtaining ultra-fast polarized proton sources.

With the forthcoming 10–100PW laser facilities, laser-driven electron–positron-pair production has gained particular interest. Here, a scheme to enhance the generation of dense electron–positron-pairs is proposed and numerically demonstrated, employing double laser pulses at the intensity level of 10 23 W c m − 2 . The first laser accelerates a thin foil to a relativistic speed via the radiation-pressure-acceleration mechanism and a counter-propagating laser irradiates this flying plasma layer. The simulation results indicate that a high-yield and well-collimated positron beam ( ∼ 5.5 × 10 10 positrons/pulse, 8.8 nC/pulse) is generated with a large peak density 1.1 × 10 21 c m − 3 by using tens-of-PW laser pulses.

Extreme-ultravoilet (XUV) attosecond pulses with durations of a few tens of attosecond have been successfully applied for exploring ultrafast electron dynamics at the atomic scale. But their weak intensities limit the further application in demonstrating nonlinear responses of inner-shell electrons. Optical attosecond pulses will provide sufficient photon flux to initiate strong-field processes. Here we proposed a novel method to generate an ultra-intense isolated optical attosecond pulse through relativistic multi-cycle laser pulse interacting with a designed gas-foil target. The underdense gas target sharpens the multi-cycle laser pulse, producing a dense layer of relativistic electrons with a thickness of a few hundred nanometers. When the dense electron layer passes through an oblique foil, it emits single ultra-intense half-cycle attosecond pulse in the visible and ultraviolet spectral range. The emitted pulse has a peak intensity exceeding 1018 W/cm2 and full-width-half-maximum duration of 200 as. The peak power of this attosecond light source reaches 2 terawatt. The proposed method relaxes the single-cycle requirement on the driving pulse for isolated attosecond pulse generation and significantly boosts the peak power, thus it may open up the route to new experiments tracking the nonlinear response of inner-shell electrons as well as nonlinear attosecond phenomena investigation.

Ion pumping microbial rhodopsins are photochemically active membrane proteins, converting light energy into ion-motive-force for ATP synthesis. Nonlabens dokdonensis rhodopsin 2 (NdR2), was recently identified as a light-driven Na+ pump. However, few functional studies on NdR2 have been conducted to elucidate its mechanism of ion transport. By reconstituting NdR2 into liposomes, we proved that NdR2 functions as a light-driven Na+/H+ pump. As Na+ concentration increased, the dominant H+ pump activity switched to the Na+ pump activity at neutral pH. The inversion of pH change by the addition of CCCP at low Na+ further suggested that the transport of Na+ and H+ should coexist in NdR2. By increasing H+ concentration, the affinity for Na+ lowered, which was indicated by an increase in KM from ~31mM at pH ~7.5, to ~74mM at pH ~6.5. These results demonstrated that Na+ transport competed with H+ transport in NdR2, which was confirmed by the dominant H+ pump activity at pH ~5.7. Kinetic experiments using pyranine uncovered a transient H+ uptake, followed by an H+ release at the millisecond time scale in both Na+ and K+ solutions. Therefore, these NdR2 results may provide functional and kinetic insights into the ion transport mechanism in light-driven Na+ pumps.

Immune responses are often accompanied by radical changes of cellular metabolism of immune cells. On the other hand, an ever increasing number of metabolic pathways and products have been found to possess immune regulatory functions. The field of immunometabolism that investigates the interplay between metabolism and immunity has developed rapidly during the past decade. In this chapter, we attempt to summarize the recent progresses by scientists in China on metabolic regulation of innate immunity from the following three perspectives: metabolic regulation of myeloid cell functions, metabolic adaptations of tissue resident myeloid cells, and metabolism and immunity at the mucosal surfaces.

Transcription factor RBP-J in intestinal macrophages dynamically controls antibacterial immunity by interfacing with T cells and ILCs. Macrophage-intrinsic RBP-J supports intestinal Th17 cell responses via IL-6 production, whereas RBP-J deficiency unexpectedly reveals a compensatory role for ILC3 late during infection., Macrophages play pleiotropic roles in maintaining the balance between immune tolerance and inflammatory responses in the gut. Here, we identified transcription factor RBP-J as a crucial regulator of colonic macrophage–mediated immune responses against the enteric pathogen Citrobacter rodentium. In the immune response phase, RBP-J promoted pathogen clearance by enhancing intestinal macrophage-elicited Th17 cell immune responses, which was achieved by maintenance of C/EBPβ-dependent IL-6 production by overcoming miRNA-17∼92–mediated suppressive effects. RBP-J deficiency–associated phenotypes could be genetically corrected by further deleting miRNA-17∼92 in macrophages. In the late phase, noneradicated pathogens in RBP-J KO mice recruited abundant IL-1β–expressing CD64+Ly6C+ colonic macrophages and thereby promoted persistence of ILC3-derived IL-22 to compensate for the impaired innate and adaptive immune responses, leading to ultimate clearance of pathogens. These results demonstrated that colonic macrophage–intrinsic RBP-J dynamically orchestrates intestinal immunity against pathogen infections by interfacing with key immune cells of T and innate lymphoid cell lineages., Graphical Abstract

Immune responses are often accompanied by radical changes of cellular metabolism of immune cells. On the other hand, an ever increasing number of metabolic pathways and products have been found to possess immune regulatory functions. The field of immunometabolism that investigates the interplay between metabolism and immunity has developed rapidly during the past decade. In this chapter, we attempt to summarize the recent progresses by scientists in China on metabolic regulation of innate immunity from the following three perspectives: metabolic regulation of myeloid cell functions, metabolic adaptations of tissue resident myeloid cells, and metabolism and immunity at the mucosal surfaces.

We propose a filter method to generate electron beams of high polarization from bubble and blow-out wakefield accelerators. The mechanism is based on the idea of identifying all electron-beam subsets with low polarization and filtering them out with an X-shaped slit placed immediately behind the plasma accelerator. To find these subsets we investigate the dependence between the initial azimuthal angle and the spin of single electrons during the trapping process. This dependence shows that transverse electron spins preserve their orientation during injection if they are initially aligned parallel or antiparallel to the local magnetic field. We derive a precise correlation of the local beam polarization as a function of the coordinate and the electron phase angle. Three-dimensional particle-in-cell simulations, incorporating classical spin dynamics, show that the beam polarization can be increased from 35% to about 80% after spin filtering. The injected flux is strongly restricted to preserve the beam polarization; for example, less than 1 kA in Wen et al. [Phys. Rev. Lett. 122, 214801 (2019)]. This limitation is removed by use of the proposed filter mechanism. The robustness of the method is discussed in terms of drive-beam fluctuations, jitters, the thickness of the filter, and the initial temperature. This idea marks an efficient and simple strategy to generate energetic polarized electron beams on the basis of wakefield acceleration.

Formation of memory T cells is coupled with changes of metabolic status, yet how environmental metabolites affect the transition remains largely unknown. In this issue of Immunity, Bachem et al. (2019) report that microbiota-derived butyrate enhances the memory potential of CD8+ T cells via rewiring cellular metabolism.

High brightness gamma rays can be generated by colliding an ultra-intense laser pulse with a high energy electron beam. This collision phenomenon also represents a powerful approach to explore new physics in the exotic strong field Quantum Electro-Dynamics (QED) regime. Here we show that in the cross-collision geometry, there exists a barrier induced by the classical radiation-reaction force that prohibits electrons of arbitrarily high energies to pass. However, such classical barrier vanishes in the QED picture, where electrons can be well reflected (transmitted) in the regimes forbidden by classical theory. This effect can be measured in the up-coming 10–100 PW laser facilities for laser intensities at 2 × 1023 W cm−2 and electron energies of ~102 MeV. The results are capable of identifying the boundaries between classical and QED approaches in the strong field regime and confirming the various models describing this fundamental process. The study of electron dynamics in relativistic laser fields is a subject of major interest within the strong field physics community and has inspired several key applications aimed at accelerating charged particles. The authors present a theoretical study, and propose an experimental design, that address the interaction of electrons with intense lasers in the transition regime from classical to quantum and show that stochastic processes in the quantum regime allow electrons to be transmitted/reflected across/by the laser in the parameter region prohibited by classical dynamics.

Damaged mitochondria need to be cleared to maintain the quality of the mitochondrial pool. Here, we report mitocytosis, a migrasome-mediated mitochondrial quality-control process. We found that, upon exposure to mild mitochondrial stresses, damaged mitochondria are transported into migrasomes and subsequently disposed of from migrating cells. Mechanistically, mitocytosis requires positioning of damaged mitochondria at the cell periphery, which occurs because damaged mitochondria avoid binding to inward motor proteins. Functionally, mitocytosis plays an important role in maintaining mitochondrial quality. Enhanced mitocytosis protects cells from mitochondrial stressor-induced loss of mitochondrial membrane potential (MMP) and mitochondrial respiration; conversely, blocking mitocytosis causes loss of MMP and mitochondrial respiration under normal conditions. Physiologically, we demonstrate that mitocytosis is required for maintaining MMP and viability in neutrophils in vivo. We propose that mitocytosis is an important mitochondrial quality-control process in migrating cells, which couples mitochondrial homeostasis with cell migration.

The upper limit of the laser field strength in a perfect vacuum is usually considered as the Schwinger field, corresponding to ∼ 10 29 W / cm 2 . We investigate such limitations under realistic nonideal vacuum conditions and find that intensity suppression appears starting from 10 25 W / cm 2 , showing an upper threshold at 10 26 W / cm 2 level if the residual electron density in chamber surpasses 10 9 cm − 3 . This is because the presence of residual electrons triggers the avalanche of quantum electrodynamics cascade that creates copious electron and positron pairs. The leptons are further trapped within the driving laser field due to radiation reaction, which significantly depletes the laser energy. The relationship between the attainable intensity and the vacuity is given according to particle-in-cell simulations and theoretical analysis. These results answer a critical problem on the achievable light intensity based on present vacuum conditions and provide a guideline for future hundreds of petawatt class laser development.

The generation of polarized particle beams still relies on conventional particle accelerators, which are typically very large in scale and budget. Concepts based on laser-driven wake-field acceleration have strongly been promoted during the last decades. Despite many advances in the understanding of fundamental physical phenomena, one largely unexplored issue is how the particle spins are influenced by the huge magnetic fields of plasma and, thus, how highly polarized beams can be produced. The realization of laser-plasma based accelerators for polarized beams is now being pursued as a joint effort of groups from Forschungszentrum J\"ulich (Germany), University of Crete (Greece), and SIOM Shanghai (China) within the ATHENA consortium. As a first step, we have theoretically investigated and identified the mechanisms that influence the beam polarization in laser-plasma accelerators. We then carried out a set of Particle-in-cell simulations on the acceleration of electrons and proton beams from gaseous and foil targets. We could show that intense polarized beams may be produced if pre-polarized gas targets of high density are employed. In these proceedings we further present that the polarization of protons in HT and HCl gas targets is largely conserved during laser wake-field acceleration, even if the proton energies enter the multi-GeV regime. Such polarized sources for electrons, protons, deuterons and $^{3}$He ions are now being built in J\"ulich. Proof-of-principle measurements at the (multi-)PW laser facilities PHELIX (GSI Darmstadt) and SULF (Shanghai) are in preparation., Comment: submitted to IOP

We present an experimental demonstration of the efficient acceleration of electrons beyond 60 MeV using micro-channel plasma targets. We employed a high-contrast, 2.5 J, 32 fs short pulse laser interacting with a 5 \mu m inner diameter, 300 \mu m long micro-channel plasma target. The micro-channel was aligned to be collinear with the incident laser pulse, confining the majority of the laser energy within the channel. The measured electron spectrum showed a large increase of the cut-off energy and slope temperature when compared to that from a 2 \mu m flat Copper target, with the cutoff energy enhanced by over 2.6 times and the total energy in electrons >5 MeV enhanced by over 10 times. Three-dimensional particle-in-cell simulations confirm efficient direct laser acceleration enabled by the novel structure as the dominant acceleration mechanism for the high energy electrons. The simulations further reveal the guiding effect of the channel that successfully explains preferential acceleration on the laser/channel axis observed in experiments. Finally, systematic simulations provide scalings for the energy and charge of the electron pulses. Our results show that the micro-channel plasma target is a promising electron source for applications such as ion acceleration, Bremsstrahlung X-ray radiation, and THZ generation., Comment: 23 pages, 5 figures

We propose a new approach based on an all-optical set-up for generating relativistic polarized electron beams via vortex Laguerre-Gaussian (LG) laser-driven wakefield acceleration. Using a pre-polarized gas target, we find that the topology of the vortex wakefield resolves the depolarization issue of the injected electrons. In full three-dimensional particle-in-cell simulations, incorporating the spin dynamics via the Thomas-Bargmann Michel Telegdi equation, the LG laser preserves the electron spin polarization by more than 80% at high beam charge and flux. The method releases the limit on beam flux for polarized electron acceleration and promises more than an order of magnitude boost in peak flux, as compared to Gaussian beams. These results suggest a promising table-top method to produce energetic polarized electron beams., Comment: We replace some results and revise some descriptions

Positron acceleration in plasma wakefield faces significant challenges, as the positron beam must be pre-generated and precisely coupled into the wakefield and, most critically, suffers from defocusing issues. Here we propose a scheme that utilizes laser-driven electrons to produce, inject, and accelerate positrons in a single setup. The high-charge electron beam from wakefield acceleration creates copious electron–positron pairs via the Bethe–Heitler process, followed by enormous coherent transition radiation due to the electrons’ exiting from the metallic foil. Simulation results show that the coherent transition radiation field reaches up to tens of GV m−1, which captures and accelerates the positrons to cut-off energy of 1.5 GeV with energy peak of 500 MeV (energy spread ~ 24.3%). An external longitudinal magnetic field of 30 T is also applied to guide the electrons and positrons during the acceleration process. This proposed method offers a promising way to obtain GeV fast positron sources.

We investigate the precession of electron spins during beam-driven plasma-wakefield acceleration based on density down-ramp injection by means of full three-dimensional (3D) particle-in-cell (PIC) simulations. A relativistic electron beam generated via, e.g., laser wakefield acceleration, serves as the driving source. It traverses the prepolarized gas target and accelerates polarized electrons via the excited wakefield. We derive the criteria for the driving beam parameters and the limitation on the injected beam flux to preserve a high degree of polarization for the accelerated electrons, which are confirmed by our 3D PIC simulations and single-particle modeling. The electron-beam driver is free of the prepulse issue associated with a laser driver, thus eliminating possible depolarization of the prepolarized gas due to ionization by the prepulse. These results provide guidance for future experiments towards generating a source of polarized electrons based on wakefield acceleration.

The objective of the present study is to investigate the mechanism of tetracyclines and macrolieds absorption on Taihu Lake sediments. In the study, batch technique was used to study the adsorptive behavior of three pharmaceutical antibiotics (tetracycline, oxytetracycline and tylosin) from several sediments of Taihu Lake, Zhushan Bay, Western Lakeshore, Lake Center, Southern Lakeshore, East Tai Lake, Eastern Lakeshore, Gonghu Bay and Meiliang Bay. The eight sediments showed extraordinarily high absorption affinity for all the tested antibiotics. However, especially the sediments of East Tai Lake was exceptional. The observed sorbent to solution distribution coefficient (K(d), 1 kg(-1)) was 10(2)-10(4) . The sediment of East Tai Lake showed highest organic carbon content and cation exchange capacity. A remarkably strong sorption of antibiotics to the sediment of East Tai Lake can be attributed to the cation exchange and complexation reactions between the functional groups of antibiotics and the respective charged and polar sites of the sorbents. The sorption affinity of tetracycline and oxytetracycline from the eight sediments was higher than tylosin. Tetracycline and oxytetracycline had multiple polar and ionizable functional groups. In the study within the tested pH, the zwitterion speciation is predominated; therefore, the sorption interaction (cation exchange and surface complexation) between tetracycline and sediments was expected stronger than tylosin.

According to the thermodynamics analysis, the molar enthalpy change, the molar entropy increase, the Gibbs free energy change and the balance constant of indium iodide polycrystal synthesis reaction were calculated in order to evaluate the feasibility of reaction temperature on 653 K. After the temperature 653 K was applied in the synthesis experiment, indium iodide polycrystal was successfully obtained by the two-zone vapor transporting method. The result of X-ray diffraction analysis indicates the temperature 653K can be used for indium iodide polycrystal synthesis.

Pyrene-terminated liquid crystalline polymers (poly [8-(4-cyano-4′-biphenyl)-1-octanoylacrylate] and poly [6-(4-cyano-4′-biphenyl)-1-hexanoylacrylate]) were synthesized and used to functionalize graphene sheets via π–π interactions. The resulting liquid crystalline polymers functionalized graphene sheets were characterized by UV–vis spectroscopy, fluorescence spectroscopy, thermal gravimetric analysis, Fourier transform infrared spectroscopy, X-ray diffraction, atomic force microscopy and Raman spectroscopy. It was found that an intercalated layer structure was formed when polymer was grafted onto graphene sheets. The liquid crystalline polymers were able to effectively disperse graphene in N,N-dimethylformamide that were stable for months. Additionally, a remarkable smaller distance of adjacent mesogenic units was observed, which is attributed to the confinement of the polymer chains between 2D reduced graphene oxide sheets.

A series of narrowly distributed diblock copolymers composed of amorphous components and side-chain liquid crystalline (LC) polymer, poly (butyl acrylate)- block -poly [8-(4-cyano-4′-biphenyl)-1-octanoyl acrylate] (PBA- b -PCBOA), with side-chain LC block weight fraction ( f w,PCBOA ) ranging from 25% to 87%, were synthesized by atom transfer radical polymerization (ATRP). Their thermal property, LC behavior, bulk phase behavior and thin film morphology were studied by differential scanning calorimetry (DSC), polarizing optical microscope (POM), small-angle X-ray scattering (SAXS) techniques and atomic force microscopy (AFM), respectively. The results show the diblock copolymers with different composition could present sphere, lamellar and cylinder morphologies before the order–disorder transition. As the mesogen units self-organize to form smectic phase, the lamellar morphology dominates during the majority LC block weight fraction range ( f w,PCBOA = 46%–77%) to minimized the surface energy. Interestingly, for spin-coated thin film, the lamella phase separation size decreased with increasing annealing time. For the copolymer with f w,PCBOA of 67%, a thermoreversible order–order transition (OOT) and lamella to lamella/modified layer (L/ML), were observed.

A biologically inspired, multilayer laminate structural design is deployed in composite films of polystyrene (PS) grafted graphene oxide (GO) synthesized by a Ce(IV)/HNO3 redox system in aqueous solution. Artificial hybrid films are fabricated using a vacuum-assisted filtration macroscopic assembly method, using nacre as the structural model, GO as the inorganic building blocks and PS as glue. The resulting multilayer structure and the mechanical properties of the nanopaper were studied by scanning electron microscopy, X-ray diffraction and stress–strain measurements. The resulting multilayer GO–PS films with low polymer content (

A new spin-dependent deflection mechanism is revealed by considering the spin-correlated radiation-reaction force during laser-electron collision. We found that such deflection originates from the non-zero work done by the radiation-reaction force along the laser polarization direction in each half-period, which is larger/smaller for spin-anti-paralleled/spin-paralleled electrons. The resulted anti-symmetric deflection is further accumulated when the spin-projection onto the laser magnetic field is reversed in adjacent half-periods. The discovered mechanism dominates over the Stern–Gerlach deflection for electrons of several hundreds of MeV and 10 PW-level laser peak power. The results provide a new perspective to study the strong-field QED physics in quantum radiation-reaction regime and an approach to leverage the study of radiation-dominated and strong-field QED physics via particle spins.

A one-pot method is introduced to construct three-dimensional (3D) nanohybrid composites by combining one-dimensional (1D) carbonaceous polypyrrole nanotubes with two-dimensional (2D) graphene sheets. The morphologies of 3D nanostructure can be controlled by adjusting the raw material ratio of pyrrole to GO. Interestingly, when the ratio is suitable, the interconnected structured formed. Nanotubes tend to be covered by nanosheets and interacted with each other tightly. The resulting material has a Brunauer-Emmett-Teller (BET) surface area of 1173 m 2 g −1 , a total pore volume of 0.66 cm 3 g −1 , and an average pore diameter of 3.0 nm. And this material used as supercapacitor shows high specific capacitance, good rate capability and still retains 94.5% of the initial capacitance even after 10,000 cycles.

Interaction of laser plulses with intensities up to 1025 W/cm2 with overdense plasma targets is investigated via three-dimensional particle-in-cell simulations. At these intensities, radiation of electrons in the laser field becomes important. Electrons transfer a significant fraction of their energy to γ-photons and obtain strong feedbacks due to radiation reaction (RR) force. The RR effect on the distribution of laser energies among three main species: electrons, ions and photons is studied. The RR and electron-positron pair creation are implemented by a QED model. As the laser intensity inreases, the ratio of laser energy coupled to electrons drops while the one for γ-photons reaches up to 35%. Two distinctive plasma density regimes of the high-density carbon target and low-density solid hydrogen target are identified from the laser energy partitions and angular distributions of photons. The power-laws of absorption efficiency versus laser intensity and the transition of photon divergence are revealed. These show enhanced generation of γ-photon beams with improved collimation in the relativistically transparent regime. A new effect of transverse trapping of electrons inside the laser field caused by the RR force is observed: electrons can be unexpectedly confined by the intense laser field when the RR force is comparable to the Lorentz force. Finally, the RR effect and different regions of photon emission in laser-foil interactions are clarified.

Summary Macrophage polarization is accompanied by drastic changes in L-arginine metabolism. Two L-arginine catalytic enzymes, iNOS and arginase 1, are well-characterized hallmark molecules of classically and alternatively activated macrophages, respectively. The third metabolic fate of L-arginine is the generation of creatine that acts as a key source of cellular energy reserve, yet little is known about the role of creatine in the immune system. Here, genetic, genomic, metabolic, and immunological analyses revealed that creatine reprogrammed macrophage polarization by suppressing M(interferon-γ [IFN-γ]) yet promoting M(interleukin-4 [IL-4]) effector functions. Mechanistically, creatine inhibited the induction of immune effector molecules, including iNOS, by suppressing IFN-γ-JAK-STAT1 transcription-factor signaling while supporting IL-4-STAT6-activated arginase 1 expression by promoting chromatin remodeling. Depletion of intracellular creatine by ablation of the creatine transporter Slc6a8 altered macrophage-mediated immune responses in vivo. These results uncover a previously uncharacterized role for creatine in macrophage polarization by modulating cellular responses to cytokines such as IFN-γ and IL-4.

By the reactive self-degraded template-directed synthesis and further carbonization, N- and O-doped carbonaceous nanotubes from conducting polymer (polypyrrole) precursor have been prepared. After being chemically activated by KOH, specially, with the weight ratio of KOH to polypyrrole nanotubes of 2 and 4, two samples of activated carbonaceous polypyrrole nanotubes (ACPN-2 and ACPN-4) with an uncapped morphology were obtained. The ACPN-4 possesses high heteroatom content (14.85%) and specific surface area (1226 m 2 g −1 ), and exhibits a reversible capacitance of 470 F g −1 at the current density of 0.2 A g −1 , and 280 F g −1 even at a higher current density of 10 A g −1 . Moreover, these nanotubular structured materials have also shown excellent cycling performance with no capacitance loss over 10,000 cycles. Furthermore, these carbonaceous nanotubes achieved a high CO 2 adsorption uptake of 3.9 mmol g −1 at 273 K and 2.5 mmol g −1 at 298 K.

Plasma wakefield excited by a short TeV-scale proton beam is investigated in the highly nonlinear regime. Analysis of the “bubble” field illustrates that transverse expelling force of the wakefield can be compensated by the attractive force, which originates from the co-propagating electrons within the proton bunch, leading to a collimation effect that stabilizes the beam propagation. The protons located in the beam tail can be well-confined and accelerated forward for a long distance. Two-dimensional simulations show that after a 1-TeV proton bunch propagating through plasma for a distance, several percentages of the protons achieve a remarkable energy gain. This scheme presents a potential that proton beams from conventional accelerators may gain considerable additional energy through plasmas wakefields.

We demonstrated here the lyotropic liquid crystalline behavior of an aqueous solution of graphene oxide (GO) sheets. Scanning electron microscope experiments revealed GO sheets self-assembled into fiber-like or sheet-like structures at different concentrations under flow conditions. As a result, the solution viscosity decreased dramatically with increasing shear stress.

Ion pumping microbial rhodopsins are photochemically active membrane proteins, converting light energy into ion-motive-force for ATP synthesis. Nonlabens dokdonensis rhodopsin 2 (NdR2), was recently identified as a light-driven Na

The improved laser-to-pedestal contrast ratio enabled by current high-power laser pulse cleaning techniques allows the fine features of the target survive before the main laser pulse arrives. We propose to introduce the nano-fabrication technologies into laser–plasma interaction to explore the novel effects of micro-structures. We found out that not only laser-driven particle sources but also the laser pulse itself can be manipulated by specifically designed micro-cylinder and -tube targets, respectively. The proposal was supported by full-3D particle-in-cell simulations and successful proof-of-principle experiments for the first time. We believe this would open a way to manipulate relativistic laser–plasma interaction at the micro-size level.

Graphenes are an emerging class of carbon nanomaterials whose adsorption properties toward organic compounds have not been well understood. In the present study, graphene nanosheets were prepared by reoxidation and abrupt heating of graphite oxide, which was prepared by sequential chemical oxidation of commercial nonporous graphite powder. Adsorption properties of three aromatic compounds (naphthalene, 2-naphthol, and 1-naphthylamine) and one pharmaceutical compound (tylosin) on graphene nanosheets and graphite oxide were examined to explore the potential of these two adsorbents for the removal of organic contaminants from aqueous solutions. Compared with the literature data of adsorption on carbon nanotubes, adsorption of bulky, flexible tylosin on graphene nanosheets exhibited markedly faster adsorption kinetics, which can be attributed to their opened-up layer structure. Graphene nanosheets and graphite oxide showed similar sequences of adsorption affinity: 1-naphthylamine > 2-naphthol > tylosin > naphthalene (with much larger differences observed on graphite oxide). It was proposed that the strong adsorption of the three aromatic compounds was mainly due to π-π electron donor-acceptor interactions with the graphitic surfaces of adsorbents. Additionally, Lewis acid-base interaction was likely an important factor contributing to the strong adsorption of 1-naphthylamine and tylosin, especially for the O-functionality-abundant graphite oxide. After being normalized on the basis of adsorbent surface area, adsorption affinities of all four tested adsorbates on graphene nanosheets were very close to those on nonporous graphite powder, reflecting complete accessibility of the adsorbent surface area in adsorption.

An optical vortex with orbital angular momentum (OAM) enriches the light and matter interaction process, and helps reveal unexpected information in relativistic nonlinear optics. A scheme is proposed for the first time to explore the origin of photons in the generated harmonics, and produce relativistic intense harmonics with expected frequency and an optical vortex. When two counter-propagating Laguerre-Gaussian laser pulses impinge on a solid thin foil and interact with each other, the contribution of each input pulse in producing harmonics can be distinguished with the help of angular momentum conservation of photons, which is almost impossible for harmonic generation without an optical vortex. The generation of tunable, intense vortex harmonics with different photon topological charge is predicted based on the theoretical analysis and three-dimensional particle-in-cell simulations. Inheriting the properties of OAM and harmonics, the obtained intense vortex beam can be applied in a wide range of fields, including atom or molecule control and manipulation.