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Germanium selenide is a promising material for electronic, photovoltaic, and thermoelectric applications; however, structural phase transitions of GeSe under pressure are controversial. Combining evolutionary algorithms, density functional theory, tight-binding method, and laser-heated diamond anvil cell experiments, pressure-induced phase transitions of GeSe are thoroughly investigated. Two novel intermediate phases are predicted to exist in between the well-known α-GeSe and the recently discovered β-GeSe under high pressure. α-GeSe is found to transform into a rhombohedral crystal structure with a space group of R3m at a low hydrostatic pressure. The R3m phase of GeSe exhibits robust ferroelectricity analogous to GeTe. By further increasing the pressure to approximately 6 GPa, the R3m phase is predicted to transform into a rock-salt structure, becoming a 3D topological crystalline insulator with an inverted band structure. The newly discovered GeSe high-pressure phases greatly enrich our knowledge of IV–VI compounds. The atoms in germanium selenide can adopt more configurations than previously thought according to a study by researchers in China. A phase change, the rearrangement of atoms in a solid from one crystal structure to another, can radically alter a material’s properties. Such a change in phase can be induced by exposing matter to high pressure. Kuo Li from the Center for High Pressure Science and Technology Advanced Research in Beijing, Yue Chen from The University of Hong Kong, and their co-workers have combined multiple computational and experimental techniques to identify the phases of germanium selenide, a material useful for energy conversion. Recently a high-pressure phase called β-GeSe was discovered in addition to the common low-pressure α-GeSe phase. The researchers predict two further phases at intermediate pressure, each with its own distinctive electrical properties. Pressure-induced phase transitions in GeSe are investigated from theory and experiment. Two new phases are predicted to exist in-between the well-known α-GeSe and the recently discovered β-GeSe under pressures. It is predicted that α-GeSe transforms into a rhombohedral structure with a space group of R3m and exhibits robust ferroelectricity at a low hydrostatic pressure. Laser-heated DAC experiments have been conducted to provide further evidence on the existence of the R3m phase. By increasing the hydrostatic pressure to approximately 6 GPa, the R3m phase is predicted to transform into a rock-salt crystal structure ( $$Fm\bar 3m$$ ) and become a topological crystalline insulator.

In Southern China, plants are usually exposed to cold stress during winter in an unheated greenhouse, but due to the high energy consumption and costs, most of the greenhouses remain unheated. In an attempt to find a simple and affordable solution to this problem, this study was undertaken. In this research, Capsicum frutescens L. plants were studied to investigate the effect of different root zone temperatures on its growth and chlorophyll fluorescence characteristics under cold stress. The plants were cultivated under cold stress conditions in a root zone temperature (RZT) control system where the roots were subjected to four different root-zone temperature treatments of 20°C-T20, 25°C-T25, 45°C-T45 and a control CK group. Growth characteristics studied included plant height, stem diameter, plant width, root length, biomass accumulation. Whilst fluorescence characteristics investigated were chlorophyll fluorescence ratio Fv/Fm, photochemical quenching (qL), efficiency of Photosystem II (Y[II]) and electron transport rate (ETR). Chlorophyll content in the leaves of the plants was also investigated. The findings demonstrated that plants in the CK group suffered a detrimental effect on the growth characteristics registering the lowest values in the measured variables. Conversely, the highest values were observed in T25 RZT treatment. In fluorescence characteristics, values of Fv/Fm were maintained at between 0.8 and 0.83 but also suffered a photo-inhibitory depression in CK and T45 RZT treatments to Fv/Fm values of

Lack of normal differentiation was considered as a common defect in cancer cells. MS4A12, a colon-specific gene, belongs to MS4A family that plays an important role in differentiation, proliferation and cell cycle regulation. The aim of the study was to investigate MS4A12 role in colon cancer cell differentiation and its prognostic value in colon cancer. We used sodium butyrate (BS) to set up differentiated model of colon cancer cell line LoVo. Cell differentiation was evaluated with ALP activity and E-cadherin. We used BS (4 mmol/L) inducing differentiation of LoVo cell and found after BS treated over 48h MS4A12 variant-1 (one of MS4A12 gene transcripts) as well as ALP and E-cadherin of LoVo cells were all increased significantly. When silence MS4A12 variant-1, the elevation of ALP and E-cadherin in BS-treated cells were all inhibited. Besides, after silence MS4A12 variant-1, the cells showed significant resistances to BS function of induction cell cycle arrest and apoptosis. Survival analysis used GEO datasets GSE39582 and GSE38832 that include 681 distinct colon cancer samples. Log-rank test and Cox's proportional hazards regression were applied to analyzing single and multiple prognostic variables, respectively. In early stage colon cancer, the patients with low MS4A12 expression had a poor survival (HR=1.72; p=0.036), while in advanced stage colon cancer MS412 had little prognostic value (HR=0.89; p=0.601). These results indicated MS4A12 might relate to colon cancer cell differentiation and supposed to be a risk classification marker for early stage colon cancer.

The oil-impregnated paper plays a critical role in the reliability and safety of converter transformer, which is suffered by the accumulation of charges on oil-impregnated paper, leading to distorting the electric field and overvoltage. In addition, the problem of temperature rise is more prominent in contrast with the power transformer, which is attributed to the DC magnetic bias and harmonic current. As a consequence, the performance deterioration of oil-impregnated paper is a comprehensive result from multiple factors including thermal stress and electric field. Surface fluorination has obvious effect on the characteristics of the insulating material based on our previous work. This paper is dedicated to research effects of temperature on the charge characteristic of fluorinated oil-paper insulation under the coupling of DC and pulse voltage. The conclusions can be drawn that The strong electronegativity of fluorine and the tiny voids generated by fluorination contributes to capturing carriers for inhibiting the increase level of carrier mobility. The temperature rise has more influence in modifying the trap depth of the fluorinated paper in contrast with the trap density.

Rice variation induced by the introduction of exogenous DNA has become an important method of improving rice varieties and creating new germplasms. In this study, we transferred maize genomic DNA fragments to the receptor of Nipponbare rice using a modified "pollen-tube pathway" method. Material from mutant rice B1 and B2 were acquired and 14 specific bands were obtained from the material using amplified fragment length polymorphism analysis. From the 14 specific sequences obtained, there were 3791 bp, including 144 base mutations with a base mutation rate of 3.80%. Specific bands resulted from base mutation of selective bases or restriction endonuclease recognition sequences, or insertion or deletion of DNA fragments. The frequency of single-base mutations was significantly higher than that of double-base mutations, three-sequential base mutations, and multiple-sequential base mutations. The site frequency of base substitution (87.04%) was significantly higher than that of base insertion (3.70%) or deletion (9.26%). In all cases of base substitution, the frequency of transition (76.47%) was significantly higher than transversion (23.53%). The above results indicate that transferring foreign-species DNA into rice cells can induce base mutations in the receptor, with base substitutions occurring at the highest frequency, and the dominant type of base substitutions being transition. Preliminary analysis reveals that the molecular mechanism of transferring exogenous DNA into rice causes mutations, which provides theoretical data on biological mutagenesis for further research.

Vascular calcification is one of the most important factors for high morbidity and mortality from cardiovascular and cerebrovascular diseases. The aim of this study is to investigate the effect and mechanism of miR-26a on vascular smooth muscle cell calcification. First, the VSMCs were induced by β-glycerol phosphate (β-GP) for 7d and 14d, and Alizarin Red S staining was performed to examine the mineralized nodule change; then real time RT-PCR and western blotting were performed to explore the expression of miR-26a, CTGF, OPG, RANKL and ALP in un-induced and β-GP-induced VSMCs; next, the VSMCs were transfected with miR-26a mimics, and Alizarin Red S staining was performed to examine the mineralized nodule change; finally, real time RT-PCR and western blotting were performed to explore the expression of miR-26a, CTGF, OPG, RANKL and ALP in un-transfected and miR-26a mimics transfected VSMCs. After β-GP treatment, β-GP promoted clear mineralized nodule changes, and miR-26a and OPG expression were significantly decreased and CTGF, RANKL and ALP expression were increased in VSMCs. Overexpression of miR-26a inhibited VSMCs calcification induced by β-GP, and regulated the expression of CTGF, OPG, RANKL and ALP. Our findings suggested that up-regulation of miR-26a before β-GP treatment inhibits VSMCs calcification through targeting CTGF (Fig. 4, Ref. 18).

In this paper, the slanting silicon nanohole (SiNH) structure is systematically designed and analyzed by simulation using the finite-element method. The slanting angle of the SiNH structure is fixed at 40 $^\circ$ based on the Si(1 1 1) wafer. The impact of the SiNH diameter $(D)$ and structural periodicity $(P)$ on the light absorption has been examined. It is found that the absorption is significantly enhanced due to the much suppressed light reflection on the top surface and the strong light trapping ability of the slanting SiNH structure. At the $P$ of 700 nm and $D$ / $P$ ratio of 0.85, the optimal structural parameters are achieved with the highest ultimate efficiency of 32.9%. It is higher than that of the vertical SiNH structure counterpart which has a value of 29.7%. The physical mechanism of the enhanced light absorption is also discussed.

A structure of Ta/MgO/NiFe/MgO/Ta was designed and synthesized, which combines the advantages of both tunnel magnetoresistance materials with high magnetic field sensitivity and anisotropic magnetoresistance materials with high directional sensitivity. The magnetoresistance ratio in the device with structure of Ta(5)/MgO(4)/NiFe(10)/MgO(3)/Ta(3) (thicknesses in nanometers) increases with an increase in annealing temperature, reaching a maximum value of 3.5% at 450 °C, and then decreases with a further increase in annealing temperature. Meanwhile, a high sensitivity of 2.1%/Oe is obtained. The higher magnetoresistance ratio and sensitivity come from the significant specular reflection of electrons at both interfaces due to the crystalline MgO layer together with the sharp interfaces with the NiFe layer.

The feather is a valuable by-product with a huge annual yield produced by the poultry industry. Degradation of feathers by microorganisms is a prerequisite to utilize this insoluble protein resource. To improve the degrading efficiency of feathers, mutagenesis of the bacterium Bacillus subtilis S1-4 was performed. By combining ultraviolet irradiation and N-methyl-N'-nitro-N-nitrosoguanidine treatment for mutagenesis, a high protease-producing mutant (UMU4) of B. subtilis S1-4 was selected, which exhibited 2.5-fold higher extracellular caseinolytic activity than did the wild-type strain. UMU4 degraded chicken feathers more efficiently, particularly for the release of soluble proteins from the feathers, compared to the wild-type strain. Furthermore, an extracellular protease with a molecular weight of 45 kDa, as determined by SDS-PAGE, was purified from UMU4. Biochemical characterization indicated that the caseinolytic activity of the protease was largely inhibited by phenylmethanesulfonyl fluoride, suggesting that the purified enzyme is a serine protease. This protease was highly active over a wide range of pHs (6.0 to 12.0) and temperatures (50° to 75°C) with an optimal pH and temperature of 8.0 and 65°C, respectively. The purified enzyme exhibited good thermostability with a 72.2 min half-life of thermal denaturation at 60°C. In addition, this protease was not sensitive to heavy metal ions, surfactants, or oxidative reagents. In conclusion, strain improvement for protease production can serve as an alternative strategy to promote feather degradation. The UMU4 mutant of B. subtilis and its serine protease could be potentially used in various industries.

Large-scale two-dimensional ZnO nanocrystal films on aluminum substrate were fabricated by a one-step hydrothermal method under mild conditions, where all the ZnO nanocrystals had a lamellar structure generally perpendicular to the substrates and formed network-like porous configurations. The morphologies of the films were dependent on both the reaction temperature and concentration of zinc. The wettability of the ZnO films was assessed by measuring the water contact angle without any surface functionalisation. The porous structures of the as-prepared films could effectively enhance its hydrophobicity and the water contact angle ranged from 40° to 135° depending on the surface morphology and the arrangement of ZnO planes, indicating a simple and promising route to make aluminum surface waterproof and even self-cleaning. The hydrophobic ZnO surface could be switched to hydrophilic state by UV irradiation. A grande echelle films nanocristaux de ZnO a deux dimensions sur substrat d'aluminium ont ete fabriquees par un procede hydrothermal en une etape dans des conditions douces, ou tous les nanocristaux de ZnO ont une structure lamellaire generalement perpendiculaire aux substrats et forme des configurations poreux de type reseau. Les morphologies des films dependent a la fois la temperature de reaction et la concentration de zinc. La mouillabilite des films de ZnO a ete evaluee en mesurant l'angle de contact de l'eau sans la fonctionnalisation de surface. Les structures poreuses des films pourrait effectivement augmenter l'hydrophobie et l'angle de contact de l'eau variait de 40 a 135° en fonction de la morphologie de surface et l'arrangement des plans de ZnO, indiquant une route simple et promettant de faire surface en aluminium impermeable et meme auto-nettoyant. La surface hydrophobe de ZnO pouvaient etre transformes en etat hydrophile par irradiation UV.

The effect of laser energy fluence and substrate heating on the annealing of boron-implanted silicon–germanium epitaxial layers on silicon was investigated. By making use of the difference in the melting points of silicon–germanium and silicon, a process window in the laser energy fluence can be found such that the meltdepth was confined within the silicon–germanium. Pre-heating of the substrate to 300°C was done to reduce the laser fluence required and improve the surface morphology. Cross-sectional transmission electron microscopy showed that there were no end-of-range defects due to ion implantation at the silicon–germanium/silicon interface after the laser annealing.

In the paper, the result on femtosecond laser drilling of alumina ceramic substrate was reported. The effects of various laser parameters such as different focus position, traverse speed, drilling pattern, pausing time, etc. on the drilled hole quality in terms of surface finish, heat affected zone (HAZ), hole circularity, debris, microcracks were studied. The quality of laser-drilled holes on alumina ceramic substrates was evaluated with optical microscope, SEM/EDX, and X-ray μ-CT analysis. The optimum drilling conditions were identified. High-quality laser-drilled holes on alumina ceramic substrates were demonstrated. The developed process has potential application in manufacturing of alumina substrate based electronic devices.

A single step direct picosecond laser texturing process was demonstrated to be able to obtain a superhydrophobic surface on a nickel substrate, a key material for mold fabrication in the manufacture of various devices, including polymeric microfluidic devices. A two-scale hierarchical surface structure of regular 2D array micro-bumps with nano-ripples was produced on a nickel surface. The laser textured surface initially showed superhydrophilicity with almost complete wetting of the structured surface just after laser treatment, then quickly changed to nearly superhydrophobic with a water contact angle (WCA) of 140° in less than 1 d, and finally became superhydrophobic with a WCA of more than 150° and a contact angle hysteresis (CAH) of less than 5°. The mechanism involved in the process is discussed in terms of surface morphology and surface chemistry. The ultra-fast laser induced NiO catalytic effect was thought to play a key role in modifying the surface chemistry so as to lower the surface energy. The developed process has the potential to improve the performance of nickel mold in the fabrication of microfluidic devices.

The objective of this study was to extract yellowfin tuna (Thunnus albacores) orbital oil with supercritical carbon dioxide (SC-CO2). The effects of extracting time (60 to 300 min), temperature (30°C to 80°C), and operating pressure (15 to 40 MPa) on the yield of tuna orbital oil were systematically investigated by using single-factor analysis method. The parameters of extraction time, temperature, and pressure that led to maximal oil yield were used as the center point for a central composite design to optimize the condition of SC-CO2 extraction of tuna oil. The results showed that the optimal extraction condition for oil yield was 185.1 min, 57.8°C, and 35.8 MPa. Under this condition, the predicted value of oil yield was 20.2%, very close to the average experimental value of 20.8%. The unsaponified matter, peroxide value, and iodine value of extracted yellowfin tuna orbital oil were 0.77%, 2.33 mg kg-1, and 192.19%, respectively. Docosahexanoic acid accounted for 27.1% of the total fatty acids in the extracted oil.

In this paper, ps laser is employed to fabricate surface textures on Ni substrate. A regular 2D array of micro-bumps-based texture which is superimposed with nano-ripples has been demonstrated on Ni, which displays superhydrophobic surface property with a WCA > 150 degree. Also, 3 major types of surface textures have been fabricated on Ni mold including periodic ripples, micro-bumps array and micro-pits array pattern. Hot embossing on PMMA substrate with laser textured Ni mold has been conducted. The surface wettability of embossed polymer has been converted from original hydrophilic to highly hydrophobic with a WCA of up to 128 degree. The developed process has a potential application in the fabrication of microfluidic devices.In this paper, ps laser is employed to fabricate surface textures on Ni substrate. A regular 2D array of micro-bumps-based texture which is superimposed with nano-ripples has been demonstrated on Ni, which displays superhydrophobic surface property with a WCA > 150 degree. Also, 3 major types of surface textures have been fabricated on Ni mold including periodic ripples, micro-bumps array and micro-pits array pattern. Hot embossing on PMMA substrate with laser textured Ni mold has been conducted. The surface wettability of embossed polymer has been converted from original hydrophilic to highly hydrophobic with a WCA of up to 128 degree. The developed process has a potential application in the fabrication of microfluidic devices.

The use of organo-chlorine (DDT and HCH) has been banned in China for 20 years. A field survey was carried out during 1999-2000 in the Taihu Lake Region. Organo-chlorine pesticide (OCP) residues in soil, water, fish and sediment samples were investigated. DDT was detected in 5 out of 10 samples with concentration ranging from 0.3 to 5.3 microg/kg in the surface (0-15 cm) layer, 6 out of 10 with 0.5 to 4.0 microg/kg in the subsoil layer (16-30 cm), and 4 of 10 with 0 to 2.7 microg/ kg in the deep soil layer (31-50 cm). Results for HCH residues in soil samples were similar to those of DDT. These results indicate that OCP residues in 0-50 cm profile had been leached out or degraded to safe level. In river water DDT was detected in 10 out of 13 samples ranging from 0.2 to 9.3 microg/l, with an average of 1.0 microg/l. While HCH was detected in 12 out of 13 samples ranging from 0.02 to 36.1 microg/l, with an average 5.6 microg/l. DDT residues in sediment ranged from 0.1 to 8.8 microg/kg, while HCH ranged from 0.3 to 66.5 microg/kg. DDT residues in fish body ranged from 3.7 to 23.5 microg/kg and HCH ranged from 3.7 to 132 microg/kg. These results demonstrate an accumulation through food chain (from soil-water-sediment-microbes-crop-fish-... etc.), also that HCH residues are generally more persistent than DDT residues. However, all these data are well below than the state warning standard limit.

Dielectrostriction is a rheo-dielectric phenomenon, which reflects the variation of dielectric properties of a material with deformation. It is a fundamental property of any dielectric material, including polymers and many foods. A linear relationship has been found between the change in the dielectric constants and stresses for polymers and a chocolate spread, which is named the stress-dielectric rule. This study explored the dielectrostriction responses in three types of dark chocolate with different compositions in an oscillatory shear flow. The results revealed that the stress-dielectric rule holds well for all three types of chocolate, and the dielectrostricive response is much more sensitive than the rheological response to changes in the chocolate composition. These findings suggested that dielectrostriction measurements are a novel approach for rheological property studies, and can be developed into a powerful tool for chocolate process monitoring.

Selenium (Se) content both in total and bioavailable forms were very low (25–35 and 9.5 μg/kg, respectively) in waterlogged paddy soils in the central Yangtze River Delta. This was due to changes in geochemistry and the inherent properties of the parent materials of these lowland paddy soils. The very low Se content (23 μg/kg) in the parent material resulted in low total Se content in the soil. The main chemical changes under long-term waterlogged conditions are depletion of molecular oxygen, decrease of redox potential, and reduction of Fe (III) to Fe (II) and SeO32− to Se0. This led to low availability of Se in soils, and subsequently low Se content (29 μg/kg) in brown rice grain produced in this region. It has been suspected that low Se content in staple food might be one of the major reasons for a high infection rate of the intestine and stomach cancers and the higher death rate caused by these diseases in the region. Foliage spray of Na2SeO3 at early heading stage of rice plant growth improved the Se content of brown rice grain, hull, and straw, and would improve human and animal health. Keywords: Foliage spray, Rice grain, Wetland paddy

To obtain a full picture of microtubule (MT) behavior during the opening and closure of guard cells we have microinjected living guard cells of Vicia faba with fluorescent tubulin, examined fine detail by freeze shattering fixed cells, and used drug treatments to confirm aspects of MT dynamics. Cortical MTs in fully opened guard cells are transversely oriented from the ventral wall to the dorsal wall. When the stomatal aperture was decreased by darkness, these MTs became twisted and patched and broken down into diffuse fragments when stomata were closed. When the closed stomata were opened in response to light, the MTs in guard cells changed from the diffused, transitional pattern back to one in which MTs are transversely oriented from stomatal pore to dorsal wall. This observation indicates a linkage between these MT changes and stomatal movement. To confirm this, we used the MT-stabilizing agent taxol and the MT-depolymerizing herbicide oryzalin and observed their effects on the stomatal aperture and MT dynamics. Both drugs suppressed light-induced stomatal opening and dark-induced closure. MTs are known to be necessary for maintaining the static kidney shape of guard cells; the present data now show that the dynamic properties of polymeric tubulin accompany changes in shape with stomatal movement and may be functionally involved in stomatal movement.

Urinary bladder instillation of ovalbumin into presensitized guinea pigs stimulates rapid development of local bladder inflammation. Substance P is an important mediator of this inflammatory response, as substance P antagonists largely reverse the process. Vacuolization of the subapical endosomal compartment of the transitional epithelial cells lining the bladder suggests that changes in endosomal trafficking and fusion are also part of the inflammatory response. To test directly for substance P mediation of changes in endosomal fusion, we reconstituted fusion of transitional cell endosomes in vitro using both cuvette-based and flow cytometry energy transfer assays. Bladders were loaded with fluorescent dyes by a hypotonic withdrawal protocol before endosomal isolation by gradient centrifugation. Endosomal fusion assayed by energy transfer during in vitro reconstitution was both cytosol and ATP dependent. Fusion was confirmed by the increase in vesicle size on electron micrographs of fused endosomal preparations compared with controls. In inflamed bladders, dye uptake was inhibited 20% and endosomal fusion was inhibited 50%. These changes are partly mediated by the neurokinin-1 (NK1) receptor (NK1R), as 4 mg/kg of CP-96,345, a highly selective NK1 antagonist, increased fusion in inflamed bladders but had no effect on control bladders. The receptor-mediated nature of this effect was demonstrated by the expression of substance P receptor mRNA in rat bladder lumen scrapings and by the detection of the NK1R message in guinea pig subapical endosomes by Western blot analysis. The NK1Rs were significantly upregulated following induction of an inflammatory response in the bladder. These results demonstrate that 1) in ovalbumin-induced inflammation in the guinea pig bladder, in vitro fusion of apical endosomes is inhibited, showing endocytotic processes are altered in inflammation; 2) pretreatment in vivo with an NK1R antagonist blocks this inhibition of in vitro fusion, demonstrating a role for NK1R in this process; and 3) the NK1R is present in higher amounts in apical endosomes of inflamed bladder, suggesting changes in translation or trafficking of the NK1R during the inflammatory process. This suggests that NK1R can change the fusion properties of membranes in which it resides.

An investigation was conducted on fluoride contamination of groundwater and its impacts on human health in a rural district of Togtoh County, Inner Mongolia Autonomous Region, China. As a result of water quality analysis, a fluoride concentration higher than 1.5 mg/L was detected in 62% of the wells for water supply and the highest value was 8.0 mg/L. Because of the extra intake of fluoride from drinking water, dental fluorosis and skeletal fluorosis became popular endemic diseases in this area. The authors carried out investigations on the occurrence of fluorosis and found that the morbidity was as high as 53%. An analysis of the regional distribution of fluoride concentration of the groundwater and that of the morbidity of fluorosis showed that high occurrence of fluorosis was accompanied by high fluoride concentration. The results from two case studies are described in this paper. One shows the distribution of the morbidity of dental and skeletal fluorosis by age group in a village where fluoride contamination is extremely severe, and the other shows an example of the remarkable effect of water quality improvement on human health in another village. The influence of chloride on the young generation was stressed.

The role of 1-aminocyclopropane-1-carboxylic acid (ACC) in pollen germination was investigated in several plant species. It was found that ACC stimulated in vitro pollen germination in all five species of plants tested. EGTA and phenothiazine inhibited the increase in the germination rate induced by ACC. Free Ca2+ levels in the cytosol ([Ca2+]cyt) in ungerminated and germinated pollen were 136 and 287 nm, respectively. Adding 0.25 mm ACC to the germination medium increased the [Ca2+]cyt in germinated pollen up to 450 nm. When pollen was treated with both 0.25 mm ACC and 3.6 μm inositol 1,4,5-trisphosphate, the [Ca2+]cyt increased to 850 nm, and pollen germination was also stimulated. In the presence of Li+, an inhibitor of inositol monophosphatase, the [Ca2+]cyt was reduced to 155 nm, and the ACC-stimulated pollen germination was inhibited. The data provided evidence for the involvement of Ca2+ as a messenger in the stimulative effect of ACC on pollen germination.

International audience; Emission spectroscopy of laser-induced plasma from a thin section of mouse kidney successfully detected inorganic elements, Na, Ca, Cu, and Gd, naturally contained in the organ or artificially injected in the form of Gd-based nanoparticle. A two-dimensional scan of the sample allowed the laser beam to explore its surface with a resolution of 100 μm, resulting in a quantitative elemental mapping of the organ with sub-mM sensitivity. The compatibility of the setup with standard optical microscopy emphasizes the potential to provide multiple images of a same biological tissue with different types of response which can be elemental, molecular, or cellular.

We use transport, inelastic neutron scattering, and angle resolved photoemission experiments to demonstrate that the stoichiometric LiFeAs is an intrinsically electron-overdoped superconductor similar to those of the electron-overdoped NaFe1-xTxAs and BaFe2-xTxAs2 (T = Co,Ni). Furthermore, we show that although transport properties of the stoichiometric superconducting LiFeAs and Li-deficient nonsuperconducting Li1-xFeAs are different, their electronic and magnetic properties are rather similar. Therefore, the nonsuperconducting Li1-xFeAs is also in the electron overdoped regime, where small Li deficiencies near the FeAs octahedra can dramatically suppress superconductivity through the impurity scattering effect., 5 figures,5 pages

Laser-induced plasma is today a widespread spectroscopic emission source. It can be easily generated using compact and reliable nanosecond pulsed lasers and finds applications in various domains with laser-induced breakdown spectroscopy (LIBS). It is however such a particular medium which is intrinsically a transient and non-point light emitting source. Its timeand space-resolved diagnostics is therefore crucial for its optimized use. In this paper, we review our work on the investigation of the morphology and the evolution of the plasma. Different time scales relevant for the description of the plasma's kinetics and dynamics are covered by suitable techniques. Our results show detailed evolution and transformation of the plasma with high temporal and spatial resolutions. The effects of the laser parameters as well as the background gas are particularly studied.

We present extensive 75As NMR and NQR data on the superconducting arsenides PrFeAs0.89F0.11 (Tc=45 K), LaFeAsO0.92F0.08 (Tc=27 K), LiFeAs (Tc = 17 K) and Ba0.72K0.28Fe2As2 (Tc = 31.5 K) single crystal, and compare with the nickel analog LaNiAsO0.9F0.1 (Tc=4.0 K) . In contrast to LaNiAsO0.9F0.1 where the superconducting gap is shown to be isotropic, the spin lattice relaxation rate 1/T1 in the Fe-arsenides decreases below Tc with no coherence peak and shows a step-wise variation at low temperatures. The Knight shift decreases below Tc and shows a step-wise T variation as well. These results indicate spinsinglet superconductivity with multiple gaps in the Fe-arsenides. The Fe antiferromagnetic spin fluctuations are anisotropic and weaker compared to underdoped copper-oxides or cobalt-oxide superconductors, while there is no significant electron correlations in LaNiAsO0.9F0.1. We will discuss the implications of these results and highlight the importance of the Fermi surface topology., Comment: 6 pages, 11 figures

We report the $^{75}$As-NQR and NMR studies on the iron arsenide superconductor Li$_{x}$FeAs with $T_{\rm c} \sim 17$ K. The spin lattice relaxation rate, $1/T_{1}$, decreases below $T_{\rm c}$ without a coherence peak, and can be fitted by gaps with s$^{\pm}$-wave symmetry in the presence of impurity scattering. In the normal state, both $1/T_{1}T$ and the Knight shift decrease with decreasing temperature but become constant below $T \leq 50 K$. Estimate of the Korringa ratio shows that the spin correlations are weaker than that in other families of iron arsenides, which may account for the lower $T_{\rm c}$ in this material., Comment: 10 pages 6 figures. to appear in J. Phys. Soc. Jpn., Vol.79, No.8

The paper reports on the fabrication of silicon nanobumps on an n-doped (100) Si wafer with silica microspheres. In the process, a single 248 nm excimer laser pulse was applied on a self-assembled monolayer of 1.5-µm-diameter silica microspheres on a n-doped (100) Si wafer. After laser irradiation at a fluence of 300 mJ/cm2, a regular array of conical Si nanobumps surrounded by a ring shaped trench were fabricated. The structure of the nanobump arrays was characterized by scanning electron microscope, and atomic force microscope. The formed nanobumps were determined to be Si-based bumps with energy disperse spectroscopy. The mechanisms involved in the formation of nanobumps were discussed. The developed Si nanobump pattern has potential applications for sensitive detectors, efficient photovoltaic cells, field-emitter arrays, and displays.The paper reports on the fabrication of silicon nanobumps on an n-doped (100) Si wafer with silica microspheres. In the process, a single 248 nm excimer laser pulse was applied on a self-assembled monolayer of 1.5-µm-diameter silica microspheres on a n-doped (100) Si wafer. After laser irradiation at a fluence of 300 mJ/cm2, a regular array of conical Si nanobumps surrounded by a ring shaped trench were fabricated. The structure of the nanobump arrays was characterized by scanning electron microscope, and atomic force microscope. The formed nanobumps were determined to be Si-based bumps with energy disperse spectroscopy. The mechanisms involved in the formation of nanobumps were discussed. The developed Si nanobump pattern has potential applications for sensitive detectors, efficient photovoltaic cells, field-emitter arrays, and displays.

We demonstrate excimer laser annealed dopant segregated Schottky (ELA-DSS) junction on gate-all-around (GAA) silicon nanowire pFETs. The metal-semiconductor junction interfacial doping is increased by two-fold with the ELA method. On silicon nanowire, the method achieves an effective Schottky barrier height (SBH) of nearly zero, improves the short channel performance and reduces the parasitic resistance of the fabricated devices, leading to an average improvement of 37% in I ON as compared to the devices fabricated without laser annealing.

Spin-on silica capping has been demonstrated to be an effective dielectric encapsulant layer for quantum well (QW) intermixing at temperatures significantly lower than for conventionally deposited silica. A blueshift of up to 125 meV was observed in the photoluminescence (PL) peak energy of both GaAs and InGaAs QWs after annealing for less than 60 s at 850 °C, without noticeable degradation in the PL emission intensity. A threshold temperature was identified below which no significant QW disordering took place. The activation energy for Al diffusion in Al0.3Ga0.7As/GaAs QWs was about 2.55 eV. Broadly similar effects were seen for In0.2Ga0.8As/GaAs QWs but, in addition, strain effects appear to enhance disordering during the early stages of the anneal.

Light transport model has great potential in medical diagnosis and therapy because of the non-invasive nature of light and the selectively poisonous effect to tumors of photodynamic treatment Light transport model must be understudied for basic research and clinical application of biomedical optics., many investigators only study the diffusion equation of matched medium, they take the tissue as the same refractive index. In fact, A tissue is multi-layered mismatched medium, In order to understand the light transport in tissue,The frequency domain analytical solutions of the diffusion equation for photon migration through highly scattering a n-layered mismatched medium have been obtained. The effect of the refractive-index mismatch is taken into account, and the extrapolated boundary condition has been considered. At the same time, the phase in different situation is calculate use the model.

Postgrowth rapid thermal annealing was used to modify the structural and optical properties of the self-assembled InAs quantum dotsgrown on GaAs substrates by molecular beam epitaxy. It is found that significant narrowing of the luminescencelinewidth (from 78.9 to 20.5 meV) from the InAs dot layer occurs together with about 260 meV blueshift at annealing temperatures up to 850 °C. Observation of high-resolution transmission electron microscopy shows the existence of the dots under lower annealing temperatures but disappearance of the dotsannealed at 850 °C. The excited-state-filling experiments for the samples show that the luminescence of the samples annealed at 850 °C exhibits quantum well-like behavior. Comparing with the reference quantum well, we demonstrate significant enhancement of the interdiffusion in the dot layer. Published version

Although neurofibrillary tangles and senile plaques have been identified as the hallmark pathological changes in the brain of Alzheimer's disease (AD), the relationship between them is still not fully understood. In the present study, we have studied the effect of endogenously overproduced amyloid beta (A beta) on tau by using wild type amyloid precursor protein (APP) transfected (N2a/APP695), or Swedish mutant APP plus Delta 9 deleted presenilin-1 co-transfected (N2a/APPswe.Delta 9) and APP vector transfected (N2a/vector) cell lines. We measured the secreted and intracellular A beta, including A beta(1-40) and A beta(1-42), by Sandwich ELISA assay. It was shown that the levels of A beta were increased time-dependently in N2a/APP695 and N2a/APPswe.Delta 9 but not in N2a/vector upon butyric acid (BA) treatment. Compared with N2a/vector cells, tau in N2a/APP695 and N2a/APPswe.Delta 9 cells was not extracted by RIPA buffer, and the SDS-extracted tau protein was hyperphosphorylated at Tau-1 and PHF-1 epitopes upon BA treatment. Obvious accumulation of the hyperphosphorylated tau in N2a/APP695 and N2a/APPswe.Delta 9 cells was observed at 48 h after BA treatment. The total level of the extracted tau was reduced in N2a/APP695 and N2a/APPswe.Delta 9 lines compared with N2a/vector cells by Western blot, and this reduction of total tau was also detected by immunofluorescence staining. No obvious alteration of tau mRNA was observed in both N2a/APP695 and N2a/APPswe.Delta 9 cells compared with N2a/vector. This study provides direct evidence demonstrating that endogenously overproduced A beta not only induces tau hyperphosphorylation but also decreases the level and solubility of tau in N2a cell lines.

Globulin plays a significant role in body processes, acts as an important marker for disease diagnosis and determines blood type. Moreover, recent reports about the strong association between cancer risk and blood type imply that further studying these relationships may yield new findings on the biological mechanisms of tumorigenesis. In this paper, we propose and evaluate the efficacy of surface-enhanced Raman scattering (SERS) for the determination of this important globulin derived from human blood. Comparing globulins from different blood types by utilizing SERS spectroscopy and multivariate analysis, we show that primary structures of globulins from different blood types are similar to each other, but subtle differences in structures which may be vital for determining blood type are still observed. The abilities of globulins from different blood types to approach silver surfaces seem to differ, which also indicates that there are structural differences in blood type related globulins. Furthermore, this method differentiates blood type A from type B, type A from type O, type B from type O, type AB from type A, type AB from type B, and type AB from type O with sensitivities and specificities as follows: (90.0%, 95.0%), (80.0%, 83.9%), (95.0%, 90.3%), (97.3%, 96.7%), (94.6%, 95.5%), (100%, 100%), suggesting a potential feasibility for use in blood type identification. Our method sheds new light on blood type analysis, paves the way for the study of relationships between cancer risk and blood types, and expands the flexibility of SERS for useful applications in the life sciences.

In this paper, we have demonstrated the crystallization and simultaneous formation of the nanocone structure on the 1.6 µm thick amorphous silicon (a-Si) film using a one-step femtosecond laser annealing approach. The a-Si layer is crystallized after the annealing process, as confirmed from their Raman spectra. Meanwhile, the conical structures with diameters ranging from 160 nm to 1.4 µm are formed upon laser beam irradiation at different fluences, as deduced from scanning electron microscope and atomic force microscope characterization. The highest absorption is achieved when the sample is irradiated with a laser fluence of 588 mJ cm−2. The developed process has potential applications in the fabrication of high efficiency and low cost Si thin-film solar cells. Moreover, the physics and mechanism involved in the laser annealing process are also discussed.

Ultrafast pulsed laser irradiation is demonstrated to be able to produce surface nano-structuring and simultaneous crystallization of amorphous silicon thin film in one step laser processing. After fs laser irradiation on 80 nm-thick a-Si deposited on Corning 1737 glass substrate, the color change from light yellow to dark brown was observed on the sample surface. AFM images show that the surface nano-spike pattern was produced on amorphous-Si:H film by fs laser irradiation. Furthermore, micro-Raman results indicate that the a-Si has been crystallized into nanocrystalline Si. Also, the absorptance of the fs laser treated Si thin film was found to increase in the spectrum range of below bandgap compared to original untreated a-Si. The developed process has a potential application in fabrication of high efficiency Si thin film solar cells.

A simple approach to fabricate two-dimensional nanobump arrays on silicon (Si) substrate is reported. In the process, a single 248 nm excimer laser pulse was applied on a self-assembled monolayer of 1.5-μm-diameter silica microspheres on a n-doped (100) Si wafer. After laser irradiation at a fluence of 300 mJ/cm2, a regular array of conical Si nanobumps surrounded by a ring shaped trench were fabricated. The structure of the nanobump arrays was characterized by scanning electron microscope, and atomic force microscope. The formed nanobumps were determined to be Si-based bumps with energy disperse spectroscopy. The mechanisms involved in the formation of nanobumps were discussed.

In this letter, a low-cost alternative for forming high grade silicon germanium (SiGe) by a laser-induced crystallization of an amorphous Ge layer deposited directly on Si+ preamorphized implantation Si substrate is demonstrated. The results show that a fully strained epitaxial SiGe layer on the Si (100) substrate can be obtained at laser fluence above the epitaxial threshold. This is due to a liquid-phase epitaxial regrowth process of the laser annealing induced melted layer. Below the epitaxial threshold, polycrystalline SiGe is formed due to explosive recrystallization process. Simultaneous boron activation is achieved with the SiGe formation, a result due to the high temperature induced by the laser annealing.

Specific processing of the human immunodeficiency virus (HIV) gag and gag-pol polyprotein gene products by the HIV protease is essential for the production of mature, infections progeny virions. Inhibitors of HIV protease block this maturation and thus prohibit the spread of HIV in vitro. Previously, we reported a series of novel, symmetric inhibitors of HIV protease designed to match the C2 symmetric structure of the active site of the enzyme. In response to the poor aqueous solubility of those lead compounds, we designed a series of analogs with substantially improved (greater than 10(4) fold) solubility. These inhibitors showed anti-HIV activity in H9 and MT4 cells at 0.05 to 10 microM, and in most cases, they were noncytotoxic at concentrations in excess of 100 microM. Further examination of one inhibitor (A-77003) revealed broad-spectrum activity against both HIV types 1 and 2, including azidothymidine-resistant HIV, in a variety of transformed and primary human cell lines. After administration of the inhibitors to rats, short half-lives and, with two notable exceptions, moderate oral bioavailability were observed. Additional pharmacokinetic studies in dogs and monkeys revealed the potential utility of A-77003 as an intravenous anti-HIV agent.

Graded silicon germanium (Si1−yGey) epilayer with a thin layer of high Ge concentration (∼36%) near the surface is obtained by laser thermal annealing (LTA). The graded Si1−yGey layer is formed during a liquid phase regrowth after LTA. The relaxation in this graded Si1−yGey epilayer is insignificant; therefore it can be integrated into the source/drain of the p-type metal-oxide-semiconductor field effect transistor to induce high compressive strain to the Si channel. The thickness of the graded Si1−yGey epilayer and the concentration of the Ge near the surface can be controlled by the laser fluence, which in turn changes the strain induced to the Si channel of strained devices.

In this letter, the effect of vacancies generated by preirradiated laser on dopant diffusion and activation in preamorphized silicon substrate has been studied. Laser-induced melting in silicon was used to generate excess vacancies near the maximum melt depth before silicon substrate amorphization and subsequent boron implantation. We demonstrate that by matching the preirradiated laser melt depth with the implant amorphize depth, it can effectively reduce the silicon self-interstitials released from the end-of-range defect band. The results show great suppression in boron transient enhanced diffusion and significant removal of end-of-range defects. This is attributed to the recombination of laser-generated excess vacancies with preamorphizing induced free silicon interstitials at the end-of-range region.

In this letter, the authors study the dopant activation and dopant distribution in a Si+ subamorphized Si (SAI-Si) when subjected to laser annealing (LA). The results show an enhanced boron activation in the SAI-Si in the nonmelt regime as compared to a crystalline Si (c-Si). The enhancement is caused by a vacancy-rich surface generated by the Si+ preimplantation that promotes the incorporation of boron atoms into the substitutional sites. On the other hand, shallow-melt LA produces a similar boron activation in both SAI-Si and c-Si samples due to a melting that consumes the entire as-implanted profile and the vacancy-rich region.