Broadband wavelength-tunable second-harmonic generation (SHG) is highly desirable for multifunctional photonic integration and nonlinear light sources. However, achieving efficient SHG with wide-range tunability in a compact device remains challenging. Here, we experimentally demonstrate a lithium-niobate-embedded photonic crystal (PhC) vertical cavity that concentrates optical defect-state resonances within the photonic bandgap and places them within the second-harmonic wavelength range. By exploiting multiple defect-mode resonances, which shift spectrally under oblique incidence and overlap with other resonances at normal incidence, the SHG enhancement peaks connect seamlessly across modes, enabling continuous resonance-assisted tuning over a pump wavelength span of about 350 nm. Our results offer a scalable approach toward broadband nonlinear wavelength conversion and integrated tunable light sources.

Multi-tip diamond (MTD) tools have remarkable advantages in scratching micro-nano structures. A key component of inertial confinement fusion is a glass capsule with a periodic sinusoidal ripple nanostructure, and its processing requires very low surface roughness and a consistent nanostructure. Using MTD tools for force servo machining is an efficient method, and the focused ion beam (FIB) method has been effective in machining multi-tip diamond tools. To machine an MTD tool with high precision and efficiency, experiments were conducted to explore the influence of FIB machining parameters on tip geometries. The tip of a MTD tool with a three-dimensional periodic sinusoidal ripple was successfully prepared using optimized processing parameters. The results demonstrated that the estimated amplitude and period machining error was less than 1.71% and 1.63%, respectively, for nanoscale structured tips. Related research provides a new solution for the cross-scale and efficient processing of nanostructures.

A novel cutting strategy of machining microstructure surface with the multi-tip diamond tool based on the force modulation approach is proposed in this paper. The multi-tip diamond tool with periodic sinusoidal microstructures was prepared by focused ion beam technique. The influence of applied cutting forces on the depths of cut and material removal states was investigated experimentally. MD simulations revealed a significant phenomenon of no material side flow when using the multi-tip diamond tool cutting on single crystal copper substrate. The movement of stacking faults, Lomer-Cottrell locks and Hirth locks jointly governed the formation mechanism of machined surface. To demonstrate the feasibility and effectiveness of this proposed cutting strategy, the fabrication of periodic sinusoidal microstructures under constant forces was successfully realized on the microsphere surface. Furthermore, three-dimensional sin-shaped ripples required variable forces controlling were achieved with high-precision surface quality. The cross-sectional topography of obtained ripples matched the geometry of used MTD tool quite well. In particular, the processing parameters, including the time period of loading forces and cutting speeds, determine the expected wavelength of ripples and play a central role in the surface machining accuracy.

Large-scale micro-pitch grating is the core device of high precision computer numerical control(CNC) machine tools,and its manufacture capacity and accuracy directly affects the level of manufactured CNC machine tools. In this paper,the basic research was conducted for manufacturing the cylindrical grating template which is the core device in roller nanoimprint technology. The key process in the fabrication of micro diamond tools with focused ion beam(FIB)and the impacts of chosen parameters in ultra-precision machining on the quality of cylindrical grating template were studied. It is found that the anisotropy ofdiamond material would cause channeling effect which would degrade the shape precision of both diamond tools and the template. In order to conquer the ion channeling effect,the methods for improving the ion beam homogeneity and optimizing the parameters in FIB fabrication were studiedin detail. By DEFORM finite element modeling simulation and ultra-precision machining experiments,high precision cylindrical grating template without micro-burr was achieved by optimizing the tip angle of diamond tools and ma-chining speed.

In this article, a large scale multi-particle molecular dynamics (MD) simulation model was developed to study the dynamic structural changes in single crystal diamond under 5keV Ga+ irradiation in conjunction with a transmission electron microscopy (TEM) experiment. The results show that the thickness of ion-induced damaged layer (∼9.0nm) obtained from experiments and simulations has good accordance, which demonstrates the high accuracy achieved by the developed MD model. Using this model, the evolution of atomic defects, the spatial distributions of implanted Ga particles and the thermal spike at the very core collision area were analysed. The local thermal recrystallizations observed during each single ion collision process and the increase of the density of the non-diamond phase (mostly sp2 bonded) at irradiation area are fund to be the underling mechanisms responsible for ion fluence dependent amorphization of diamond observed in previous experiments.

Diamond cutting tools with nanometric edge radius used in ultra-precision machining can be fabricated by focused ion beam (FIB) technology. However, due to the nanoscale effects, the diamond tools performance and the cutting edge lifetime in nano cutting would be degraded because of the FIB-induced nanoscale lateral damage. In this study, the methods of how to effectively characterize and decrease the FIB-induced lateral damage for diamond tool are intensively studied. Based on the performance optimization diamond machining tools, the controllable chip thickness of less than 10 nm was achieved on a single-crystal copper in nano cutting. In addition, the ratio of minimum thickness of chip (MTC) to tool edge radius of around 0.3-0.4 in nano cutting is achieved. Methods for decreasing the FIB-induced damage on diamond tools and adding coolant during the nano cutting are very beneficial in improving the research of nano cutting and MTC. The nano cutting experiments based on the sharp and high performance of diamond tools would validate the nano cutting mechanisms that many molecular dynamic simulation studies have put forward and provide new findings for nano cutting. (C) 2014 Elsevier B.V. All rights reserved.

Hepatic production and release of endothelin-1 (ET-1) binding to endothelin B (ETB) receptors, overexpressed in the Lung microvasculature, is associated with accumulation of pro-angiogenic monocytes and vascular remodeling in experimental hepatopulmonary syndrome (HPS) after common bile duct ligation (CBDL). We have recently found that lung vascular monocyte adhesion and angiogenesis in UPS involve interaction of endothelial C-X3-C motif ligand 1 (CX3CL1) with monocyte CX3C chemokine receptor 1 (CX3CR1), although whether ET-1/ETB receptor activation influences these events is unknown. Our aim was to define if ET-1/ETB receptor activation modulates CX3CL1/CX3CR1 signaling and lung angiogenesis in experimental UPS. A selective ETB receptor antagonist, BQ788, was given for 2 weeks to 1-week CBDL rats. ET-1 (+/- BQ788) was given to cultured rat pulmonary microvascular endothelial cells overexpressing ETB receptors. BQ788 treatment significantly decreased lung angiogenesis, monocyte accumulation, and CX3CL1 levels after CBDL. ET-1 treatment significantly induced CX3CL1 production in lung microvascular endothelial cells, which was blocked by inhibitors of Ca2+ and mitogen-activated protein kinase (MEK)/ERK pathways. ET-1 induced ERK activation was Ca2+ independent. ET-1 administration also increased endothelial tube formation in vitro, which was inhibited by BQ788 or by blocking Ca2+ and MEK/ERK activation. CX3CR1 neutralizing antibody partially inhibited ET-1 effects on tube formation. These findings identify a novel mechanistic interaction between the ET-1/ETB receptor axis and CX3CL1/CX3CR1 in mediating pulmonary angiogenesis and vascular monocyte accumulation in experimental HPS.

The hepatopulmonary syndrome (HPS) develops when pulmonary vasodilatation leads to abnormal gas exchange. However, in human HPS, restrictive ventilatory defects are also observed supporting that the alveolar epithelial compartment may also be affected. Alveolar type II epithelial cells (AT2) play a critical role in maintaining the alveolar compartment by producing four surfactant proteins (SPs, SP-A, SP-B, SP-C and SP-D) which also facilitate alveolar repair following injury. However, no studies have evaluated the alveolar epithelial compartment in experimental HPS. In this study, we evaluated the alveolar epithelial compartment and particularly AT2 cells in experimental HPS induced by common bile duct ligation (CBDL). We found a significant reduction in pulmonary SP production associated with increased apoptosis in AT2 cells after CBDL relative to controls. Lung morphology showed decreased mean alveolar chord length and lung volumes in CBDL animals that were not seen in control models supporting a selective reduction of alveolar airspace. Furthermore, we found that administration of TNF-α, the bile acid, chenodeoxycholic acid, and FXR nuclear receptor activation (GW4064) induced apoptosis and impaired SP-B and SP-C production in alveolar epithelial cells in vitro. These results imply that AT2 cell dysfunction occurs in experimental HPS and is associated with alterations in the alveolar epithelial compartment. Our findings support a novel contributing mechanism in experimental HPS that may be relevant to humans and a potential therapeutic target.

作为超精密切削加工刀具的理想材料,单晶体金刚石材料的加工制造方法直接决定了刀具切削加工表面的精度和质量.由于金刚石材料具有明显的各向异性,在传统的金刚石刀具机械刃磨法中需要综合考虑制备工艺和刀具性能的协同关系,主要包括不同晶面表现出显著的物理机械性能差异、不同晶向存在显著的难磨和易磨方向等.本文针对聚焦离子束(FIB)技术加工金刚石刀具的过程中,金刚石材料性质对聚焦离子束加工质量、加工效率的影响规律等关键工艺开展了研究.研究发现,与传统的机械刃磨法相比,聚焦离子束加工是基于高能离子束的轰击溅射实现材料的去除,聚焦离子束加工中存在的级联碰撞现象显著弱化了金刚石材料各向异性的影响.

Pulmonary vascular dilation and angiogenesis underlie experimental hepatopulmonary syndrome (HPS) induced by common bile duct ligation (CBDL) and may respond to receptor tyrosine kinase (RTK) inhibition. Vascular endothelial growth factor-A (VEGF-A) expression occurs in proliferating cholangiocytes and pulmonary intravascular monocytes after CBDL, the latter contributing to angiogenesis. CBDL cholangiocytes also produce endothelin-1 (ET-1), which triggers lung vascular endothelin B receptor-mediated endothelial nitric oxide synthase (eNOS) activation and pulmonary intravascular monocyte accumulation. However, whether RTK pathway activation directly regulates cholangiocyte and pulmonary microvascular alterations in experimental HPS is not defined. We assessed RTK pathway activation in cholangiocytes and lung after CBDL and the effects of the type II RTK inhibitor sorafenib in experimental HPS. Cholangiocyte VEGF-A expression and ERK activation accompanied proliferation and increased hepatic and circulating ET-1 levels after CBDL. Sorafenib decreased each of these events and led to a reduction in lung eNOS activation and intravascular monocyte accumulation. Lung monocyte VEGF-A expression and microvascular Akt and ERK activation were also found in vivo after CBDL, and VEGF-A activated Akt and ERK and angiogenesis in rat pulmonary microvascular endothelial cells in vitro. Sorafenib inhibited VEGF-A-mediated signaling and angiogenesis in vivo and in vitro and improved arterial gas exchange and intrapulmonary shunting. RTK activation in experimental HPS upregulates cholangiocyte proliferation and ET-1 production, leading to pulmonary microvascular eNOS activation, intravascular monocyte accumulation, and VEGF-A-mediated angiogenic signaling pathways. These findings identify a novel mechanism in cholangiocytes through which RTK inhibition ameliorates experimental HPS.

High power Bessel pulses directly output from a fiber-based amplifier system are demonstrated. A compact solution based on the inverse micro-axicon (IMAX) on fiber end is proposed for the conventional ultrashort pulse fiber laser system to enable the direct generation of high power Bessel pulses from lasers without any additional exhausting alignments. The IMAX is fabricated on one facet of a ytterbium-doped large mode area fiber by focusing ion beam technique and constitutes an integrated beam shaper in combination with an inherent collimating lens in the fiber laser system. The experimental results accord qualitatively with the simulations. The system can directly generate chirped Bessel pulses with diffraction-free propagation in meter-scaled free space. The highest average power of such a wavepacket can reach 10.1 W, correspongding to 178 nJ, and the pulse duration can be dechirped to 140 fs.

BACKGROUND AND AIM:Pulmonary monocyte infiltration plays a significant role in the development of angiogenesis in experimental hepatopulmonary syndrome (HPS) after common bile duct ligation (CBDL). Hepatic monocytes are also increased after CBDL, but the origins remain unclear. Splenic reservoir monocytes have been identified as a major source of monocytes that accumulate in injured tissues. Whether splenic monocytes contribute to monocyte alterations after CBDL is unknown. This study evaluates monocyte distributions and assesses effects of splenectomy on monocyte levels and pulmonary vascular and hepatic abnormalities in experimental HPS.METHODS:Splenectomy was performed in CBDL animals. Monocyte levels in different tissues and circulation were assessed with CD68. Pulmonary alterations of HPS were evaluated with vascular endothelial growth factor-A (VEGF-A) levels, angiogenesis, and alveolar-arterial oxygen gradient (AaPO2 ). Liver abnormalities were evaluated with fibrosis (Sirius red), bile duct proliferation (CK-19), and enzymatic changes.RESULTS:Monocyte levels increased in the lung and liver after CBDL and were accompanied by elevated circulating monocyte numbers. Splenectomy significantly decreased monocyte accumulation, VEGF-A levels, and angiogenesis in CBDL animal lung and improved AaPO2 levels. In contrast, hepatic monocyte levels, fibrosis, and functional abnormalities were further exacerbated by spleen removal.CONCLUSIONS:Splenic reservoir monocytes are a major source for lung monocyte accumulation after CBDL, and spleen removal attenuates the development of experimental HPS. Liver monocytes may have different origins, and accumulation is exacerbated after depletion of splenic reservoir monocytes. Tissue specific monocyte alterations, influenced by the spleen reservoir, have a significant impact on pulmonary complications of liver disease.

Process for the synthesis of para-tolualdehyde (PTAL) via carbonylization of toluene with CO catalyzed by chloroaluminate (HI) type of ionic liquids (ILs) was investigated. Carbonylization reaction of toluene in ILs was tested. The results indicate Al2Cl7 - is the catalytic active species and the conversion of toluene increases with increasing the amount of IL used, raising reaction temperature, prolonging reaction time, or enhancing the partial pressure of CO. The ionic liquid modified by both metallic cation and Brönsted acid can improve the activity for the reaction. Furthermore, trialkylaminium-contained ILs with B-L complex acid such as IL-T IL-E and IL-P were prepared and firstly used in the reaction. It is found that their activity are much higher than IL-I, and IL-T who has the highest activity is the best catalyst for the reaction. Under the conditions of an IL/toluene molar ratio of 2.8, a CO pressure of 3.0 MPa, a temperature of 40 °C, a reaction time of 1h, conversion of toluene can be up to 56.4%.

The research progress of manufacture of diamond cutting tools based on Focused Ion Beam ( FIB) processing technology is outlined.Firstly, the research background and manufacturing progress of diamond cutting tool applied in the ultraprecision machining field is introduced .As an advanced micro-nano manufacturing technology , focused ion beam has played an important role in the micro scale diamond tools manufacturing .Aiming at the diamond tool core parameters of cutting edge radius, edge shape accuracy, the researchers carried out the FIB method and process optimization to achieve high quality diamond tool.Research found that FIB can manufacture diamond tool with edge radius as small as 15 -22 nm.Then, the applications of FIB diamond tools are presented from the two aspects of micro cutting mechanism and mi-cro-nano optical component manufacturing .Finally, future developments in this field are discussed, including, how to im-prove the FIB manufacturing efficiency and broaden the application field .

Parasitic helminth and their products can suppress or modulate the host immune response for long-term survival and continued infection. Commonly, helminth can induce conditional T helper cell type 2 (Th2) response, regulatory T cell and cytokines, and altered function of antigen presentation cells by modulating toll-like receptors (TLRs). The helminth Trichinella spiralis establishes chronic infection in skeletal muscles of a wide range of mammalian hosts. We infected mice with T. spiralis and investigated Th1/Th2/Th17 cytokine profiles in serum and expression of TLRs and related signal molecules in spleen at various times post-infection. The infection evoked a mixed Th1/Th2 and inhibited Th17 immune response, with initial predominance of a Th1 response in intestine stage and subsequent predominance of a Th2 response in muscle stage. Different stages of infection had different impacts on the expression of TLRs and related signaling molecules. In the adult stage of infection, TLR1 and TLR4 were upregulated and the MyD88-dependent signal pathway was activated. The muscle larvae inhibited TLR4 and TRIF-dependent signal pathway. Our results implied that T. spiralis infection may regulate Th1/Th2/Th17 cytokine production through TLRs.

As a core device of high precision computer numerical control (CNC) machine tools, large-scale micro-pitch grating directly determines the level of the manufacturing capacity of CNC machine tools. And it is a viable technology innovation to use nano-imprint roller technology to achieve high-precision large-scale micro-pitch grating. In this paper, a precision experiment machining platform was established for manufacturing the cylindrical grating template. And great efforts were made to improve the micro-fabricating process, and the parameters and materials were optimized during the experiments. With various factors, such as efficiency, quality of cutting, quality of nano-imprint, considered, the 20 μm, 10 μm and 4 μm pitch precision micro-cuttings of roller grating template in a full circle with the diameter of 110 mm were achieved. The number of the grooves is more than ten thousand, and the cutting time is over 62 h in the 4 μm pitch cutting process. The total splice error of the roller grating template is less than 300 nm. To solve the problem of insufficient filling during the nano-imprint, the V-shaped and trapezoid diamond tools were fabricated by focused ion beam (FIB) technology, and good nano-imprint re-suits were obtained.

MinD is a component of the Min system involved in the spatial regulation of cell division. It is an ATPase in the MinD/ParA/Mrp deviant Walker A motif family which is within the P loop GTPase superfamily. Its ATPase activity is stimulated by MinE; however, the mechanism of this activation is unclear. MinD forms a symmetric dimer with two binding sites for MinE; however, a recent model suggested that MinE occupying one site was sufficient for ATP hydrolysis. By generating heterodimers with one binding site for MinE we show that one binding site is sufficient for stimulation of the MinD ATPase. Furthermore, comparison of structures of MinD and related proteins led us to examine the role of N45 in the switch I region. An asparagine at this position is conserved in four of the deviant Walker A motif subfamilies (MinD, chromosomal ParAs, Get3 and FleN) and we find that N45 in MinD is essential for MinE-stimulated ATPase activity and suggest that it is a key residue affected by MinE binding.