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The enhancement of bovine serum albumin (BSA) fluorescence detection using a hierarchical laser-induced periodic surface structure (LIPSS) at the TC4 titanium alloy substrate was experimentally demonstrated. The hierarchical structure, including microgrooves, submicrometer LIPSS, and nanoparticles, has been achieved by a femtosecond laser. Due to the surface plasmon polariton induced by the LIPSS and localized surface plasmon resonance induced by nanoparticles, the enhancement factor of BSA fluorescence detection reached 74. Further, a good linear relationship between the concentration of copper ion inside and BSA fluorescence intensity was found in the range between 5 and 35 μg/mL. Our method explores a simple, reproducible, and pollution-free technique for surface-enhanced fluorescence.

Hyperactivation of phosphatidylinositol 3-kinase (PI3K) pathway occurs frequently in head and neck squamous cell carcinoma (HNSCC). However, clinical outcomes of targeting the PI3K pathway have been underwhelming. In present study, we investigated the resistant mechanisms and potential combination therapeutic strategy to overcome adaptive resistance to PI3K inhibitor in HNSCC. Treatment of NVP-BKM120, a pan-PI3K inhibitor, led to upregulation of interleukin-6 (IL-6) and subsequent activation of either extracellular signal-regulated kinase (ERK) or signal transducers and activators of transcription 3 (STAT3), causing modest antitumor effects on the growth of HNSCC cells. Blockade of autocrine IL-6 signaling with siRNA or neutralizing antibody for IL-6 receptor (IL-6R) completely abolished NVP-BKM120-induced activation of ERK and STAT3 as well as expression of c-Myc oncogene, which resulted in enhanced sensitivity to NVP-BKM120. Moreover, when compared with a pharmacologic inhibitor or silencing of STAT3, trametinib, a MEK inhibitor, in combination with NVP-BKM120 yielded more potent anti-proliferative effects by inhibiting S phase transition, arresting cells at G0/G1 phase, and downregulating IL-6 and c-Myc expression. Furthermore, as compared with either agent alone, combination of NVP-BKM120 with trametinib or tocilizumab, a humanized anti-IL-6R antibody, significantly suppressed tumor growth in NVP-BKM120-resistant patient-derived tumor xenograft (PDTX) models, which was also confirmed in PDTX-derived cell lines. Collectively, these results suggested that IL-6/ERK signaling is closely involved in adaptive resistance of NVP-BKM120 in HNSCC cells, providing a rationale for a novel combination therapy to overcome resistance to PI3K inhibitors.

A dual-wavelength passively Q-switched Nd:GYSGG laser using vacuum evaporating tungsten disulfide (WS_2) as a saturable absorber was demonstrated for the first time to the best of our knowledge. The WS_2 saturable absorber was prepared simply by evaporating nanometer WS_2 powders onto a quartz substrate in a vacuum. By inserting the WS_2 saturable absorber into the laser cavity, stable Q-switched laser operation was achieved with a maximum average output power of 367 mW, a pulse repetition rate of 70.7 kHz, the shortest pulse width of 591 ns, and pulse energy of about 1.05 μJ. By vacuum evaporation method, a high-quality WS_2 saturable absorber can be produced, and it seems to be a suitable method for fabrication of 2D transition metal dichalcogenides.

The effect of chemical composition on the surface characteristics of the hot-dip galvannealed (GA) steel sheets with a carbon content as low as 15 ppm strengthened by Cu and/or Mn sulfides instead of Ti and/or Nb carbides has been studied. The most important goal for developing the new type of steel sheets is focused on the achievement of the extreme surface quality to fulfill the high aesthetical requirements for defect-free automotive outer panels. The shape and distribution of the surface enrichments of Cu, Mn, Al and O on the GA steel sheets were characterized by OM, SEM and TEM. Especially, formation mechanism of the narrow streaky mark with the width of 50–100 µ m occasionally observed on the surface of GA steel sheets will be presented.

To locate anomalous features including seepage pathways through the Daeryong earth-fill dam, P and Rayleigh waves were recorded along a 250-m profile on the crest of the dam. Seismic energy was generated using a 5-kg sledgehammer and detected by 24 4.5-Hz vertical-axis geophones installed at 3-m intervals. P-wave and apparent S-wave velocities of the reservoir dam and underlying bedrock were then inverted from first-arrival traveltimes and dispersion curves of Rayleigh waves, respectively. Apparent dynamic Poisson’s ratios as high as 0.46 were obtained at the base of the dam near its north-east end, where an outlet conduit occurs, and in the clay core body near the south-west end of the profile where the dam was repeatedly grouted to abate seepage before our survey. These anomalies of higher Poisson’s ratios in the upper part of clay core were also associated with effusion of grout on the downstream slope of the dam during post-survey grouting to abate leakage. Combining P-wave traveltime tomography and inversion of Rayleigh wave velocities was very effective in detecting potential pathways for seepage and previous grouted zones in this earthen dam.

To determine subglacial topography and internal features of the Fourcade Glacier on King George Island in Antarctica, helicopter-borne and ground-towed ground-penetrating radar (GPR) data were recorded along four profiles in November 2006. Signature deconvolution, f-kmigration velocity analysis, and finite-difference depth migration applied to the mixed-phase, single-channel, ground-towed data, were effective in increasing vertical resolution, obtaining the velocity function, and yielding clear depth images, respectively. For the helicopter-borne GPR, migration velocities were obtained as root-mean-squared velocities in a two-layer model of air and ice. The radar sections show rugged subglacial topography, englacial sliding surfaces, and localised scattering noise. The maximum depth to the basement is over 79 m in the subglacial valley adjacent to the south-eastern slope of the divide ridge between Fourcade and Moczydlowski Glaciers. In the ground-towed profile, we interpret a complicated conduit above possible basal water and other isolated cavities, which are a few metres wide. Near the terminus, the GPR profiles image sliding surfaces, fractures, and faults that will contribute to the tidewater calving mechanism forming icebergs in Potter Cove.

Experimental studies were carried out to characterize the screw pumping behavior of various screw elements for a closely intermeshing counter-rotating twin screw extruder. The pumping capacity of the screw elements was compared to earlier flow simulations by some the authors of this type of twin screw extruder.

The effects of a number of different elicitors on asiaticoside production in whole plant cultures of Centella asiatica were studied, including yeast extract, CdCl 2, CuCl 2 and methyl jasmonate (MJ). Only MJ and yeast extract stimulated asiaticoside production—1.53 and 1.41-fold, respectively. Maximum asiaticoside production was achieved following treatment with 0.1 m M MJ (116.8 mg/l). The highest asiaticoside production (342.72 mg/l) was obtained after 36 days of elicitation in cultures treated with 0.1 m M MJ and 0.025 mg/l 1-phenyl-3-(1,2,3-thidiazol-5- yl)urea (TDZ). Interestingly, MJ not only stimulated the production of asiaticoside but also had an important role in the senescence of C. asiatica. Although asiaticoside content did not change when TDZ was added to medium containing an elicitor, TDZ did increase shoot growth of C. asiatica. We discuss the interactive roles of MJ and TDZ in secondary metabolic production and biomass in whole plants of C. asiatica

A novel method using a temperature-sensitive polymer (methylcellulose) to thermally gel aqueous alginate blended with distinct salts (CaCl2, Na2HPO4, or NaCl), as a pH-sensitive hydrogel was developed for protein drug delivery. It was noted that the salts blended in hydrogels may affect the structures of an entangled network of methylcellulose and alginate and have an effect on their swelling characteristics. The methylcellulose/alginate hydrogel blended with 0.7 M NaCl (with a gelation temperature of 32 °C) demonstrated excellent pH sensitivity and was selected for the study of release profiles of a model protein drug (bovine serum albumin, BSA). In the preparation of drug-loaded hydrogels, BSA was well-mixed to the dissolved aqueous methylcellulose/alginate blended with salts at 4 °C and then gelled by elevating the temperature to 37 °C. This drug-loading procedure in aqueous environment at low temperature may minimize degradation of the protein drug while achieving a high loading efficiency (95−98%). The amount of BSA released from test hydrogels was a function of the amount of alginate used in the hydrogels. The amount of BSA released at pH 1.2 from the test hydrogel with 2.5% alginate was relatively low (20%), while that released at pH 7.4 increased significantly (86%). In conclusion, the methylcellulose/alginate hydrogel blended with NaCl could be a suitable carrier for site-specific protein drug delivery in the intestine.

NiTi shape memory thin films are potentially desirable for MEMS actuators. Traditionally, there are two approaches to obtain NiTi shape memory thin films. One is to anneal amorphous NiTi films in a vacuum chamber and the other is to deposit NiTi on a high temperature substrate (about 500 °C). Both approaches have difficulty in terms of compatibility with traditional IC techniques, and are not applicable for annealing a prescribed local area of a NiTi film at the micron scale. In this paper, a new approach, CO₂ laser annealing, which can overcome both problems mentioned above, is presented. Results of optical microscopy, x-ray diffraction (XRD) and atomic force microscopy (AFM) reveal the crystalline structures and phase transformation in annealed NiTi films. Furthermore, a CO₂ laser annealed line, about 100 µm in width, demonstrates the capability of a CO₂ laser for local annealing of NiTi thin film.

An experimental study of the characterization melt spinning cyclopolyolefins is presented. The shear and complex viscosities were measured and the data was found to fit the Cox-Merz relation. The birefringence of the melt-spun filaments was determined and correlated with spinline stress. These were found to be much lower than polycarbonate and polystyrene filaments melt spun under the same conditions. The birefringence was represented in terms of polymer chain orientation. The uniaxial mechanical behavior was also measured. The Young's modulus and tensile strength generally increased with spinline stress and orientation for most cyclopolyolefins. The elongation to break decreased with measured polymer chain orientation for most cyclopolyolefins. For others it was enhanced.

An analysis of flow fields, pressure fields and screw pumping characteristics is presented for non-Newtonian fluids in various types of screw elements of an intermeshing counter-rotating twin screw extruder. These elements are in turn considered modules of a modular intermeshing counter-rotating twin screw extruder and an analysis of non-isothermal starved low in such a machine is presented. Pressure profiles, fill factor profiles and temperature profiles have been calculated for various modular screw designs of a Leistritz GG modular intermeshing counter-rotating twin screw extruder.

A simulation is presented of the flow and pumping behavior of an intermeshing counter-rotating twin screw extruder. The problem of incorporating the positive displacement characteristics of moving machine parts in a cylindrical coordinate Flow Analysis Network (FAN) analysis is presented. Screw pumping characteristic curves were determined for various elements of the Leistritz GG modular counter-rotating twin screw extruder for a Newtonian fluid. We discuss the analysis of composite modular counter-rotating twin screw extruders using these screw pumping characteristics.

Transmission electron microscopy (TEM) and atom probe field ion microscopy (APFIM) observations of pearlitic steel wire show that drawing to a true strain of 4.22 causes fragmentation of cementite lamellae into nanoscale grains. The drawing strain amorphizes some portions of the cementile lamellae in regions where the interlamellar spacing is very small, but most of the cementite lamellae are polycrystalline with nanoscale grains. The carbon concentration in the ferrite is inhomogeneous and varies from 0.2 to 3 at. pct; the carbon concentration in nanocrystalline cementite is less than 18 at. pct, significantly lower than that in stoichiometric Fe3C. Silicon is segregated to ferrite/cementite boundaries, but, in regions with a small interlamellar spacing, the silicon concentration is uniform across the lamellae. Annealing at 200 °C for 1 hour does not cause noticeable changes in the microstructure. Annealing at 400 °C or above for 1 hour causes spherodization of the cementite lamellae, and the carbon concentrations in ferrite and in cementite return to the predeformation values.

The MHD drift ballooning mode (DBM) instability near the inner edge of the near-Earth plasma sheet is studied by using both the one-fluid generalized progressing wave expansion method and the two-fluid approach. It is found that in the frame of reference at rest relative to the bulk plasma the DBM may become a purely growing mode in two distinct circumstances, which, for convenience, are called the DBM1 and DBM2, respectively. The ß threshold for the DBM1 is identical with that derived by Ohtani and Tamao[1993] and Southwood and Kivelson[1987], while the criterion of the DBM2 covers that of Miura et al. [1989]. Comparisons of the theory with GEOS 2 data show that the DBM2 is more easily excited in the late substorm growth phase. There is considerable evidence that the DBM is generated at expansion onsets. The characteristic features of magnetic field dipolarization can be interpreted in terms of the development of the DBM. The extremely thin current sheet cases should be studied with approaches other than those used in this work.

The temperature dependence of the degree of order has been studied by X-ray and electron diffraction on polycrystalline specimens on single phase of the Γ-Fe3Zn10 phase in the Fe-Zn system. The X-ray intensity of superlattice peaks started to decrease above 500°C. The intensity of the superlattice peaks recovered on the subsequent cooling; in other words the intensity change was reversible. The electron diffraction patterns obtained on quenched specimens also showed that the superlattice structure of this phase was partially disordered at high temperatures. It is suggested that the improved plasticity of the Γ-phase at high temperatures is to be attributed to the partial disordering.

Polycrystalline specimens of single phase of the Γ-Fe3Zn10 phase in the Fe-Zn system have been prepared and deformed in compression between 250 and 700°C. The thermal activation parameters have been measured and dislocation structures examined by transmission electron microscopy. Below 250°C the Γ-phase is brittle, but above 300°C it is ductile. Most of the dislocations activated under the action of an applied stress have the Burgers vectors parallel to 〈111〉 over the temperature range studied. The Burgers vector of dislocations introduced at 300 and 450°C is b = (a/2) 〈111〉, where a = 0·9005 nm (the lattice constant of the Γ-phase). On the other hand, the Burgers vector of dislocations introduced above 600°C is either b = (2a/3) 〈111〉 or b = (a/3)〈111〉. The activation volume at low temperatures (300 and 450°C) is estimated to be about 200 Å3, and it is suggested that the dislocations activated at low temperatures are dissociated into partials whose Burgers vector is 1/6〈111〉. Some evidence for the dissociation is obtained from the weak-beam electron micrographs. The reason why b is different at high temperatures and low temperatures is also discussed.

A fast and switchable electro-optic radial polarization retarder (EO-RPR) fabricated using the electro-optic ceramic Pb(Mg_1/3Nb_2/3)O_3-PbTiO_3 is presented. This EO-RPR is useful for fast and switchable generation of a pure cylindrical vector beam. When used together with a pair of half-wave plates, the EO-RPR can change circularly polarized light into any cylindrical vector beam of interest, such as radially or azimuthally polarized light. Radially and azimuthally polarized light with purities greater than 95% are generated experimentally. The advantages of using EO-RPR include fast response time, low driving voltage, and transparency in a wide spectral range (500 to 7000 nm).

We propose a new scheme for generating radially polarized light by mimicking optical activity using linear birefringence. It involves a birefringent spirally varying retarder sandwiched between two orthogonally oriented quarter-wave plates. Using Poincaré sphere representation, we show that the polarization transformation of such a scheme is equivalent to that of a spirally varying optical activity and is capable of generating radially polarized light. We demonstrate the proof-of-concept using y-cut crystalline quartz.

Laser microprocessing and nanoengineering are of great interest to both scientists and engineers, since the inspired properties of functional micro/nanostructures over large areas can lead to numerous unique applications. Currently laser processing systems combined with high speed automation ensure the focused laser beam to process various materials at a high throughput and a high accuracy over large working areas. UV lasers are widely used in both laser microprocessing and nanoengineering. However by improving the processing methods, green pulsed laser is capable of replacing UV lasers to make high aspect ratio micro-grooves on fragile and transparent sapphire substrates. Laser micro-texturing can also tune the wetting property of metal surfaces from hydrophilic to super-hydrophobic at a contact angle of 161° without chemical coating. Laser microlens array (MLA) can split a laser beam into multiple laser beams and reduce the laser spot size down to sub-microns. It can be applied to fabricate split ring resonator (SRR) meta-materials for THz sensing, surface plasmonic resonance (SPR) structures for NIR and molding tools for soft lithography. Furthermore, laser interference lithography combined with thermal annealing can obtain a large area of sub-50nm nano-dot clusters used for SPR applications.

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